path: root/release_docs/HISTORY-1_10.txt

HDF5 History
============

This file contains development history of the HDF5 1.10 branch

09.      Release Information for hdf5-1.10.7
08.      Release Information for hdf5-1.10.6
07.      Release Information for hdf5-1.10.5
06.      Release Information for hdf5-1.10.4
05.      Release Information for hdf5-1.10.3
04.      Release Information for hdf5-1.10.2
03.      Release Information for hdf5-1.10.1
02.      Release Information for hdf5-1.10.0-patch1
01.      Release Information for hdf5-1.10.0

[Search on the string '%%%%' for section breaks of each release.]

%%%%1.10.7%%%%

HDF5 version 1.10.7 released on 2020-09-11
================================================================================


INTRODUCTION

This document describes the differences between this release and the previous
HDF5 release. It contains information on the platforms tested and known
problems in this release. For more details check the HISTORY*.txt files in the
HDF5 source.

Note that documentation in the links below will be updated at the time of each
final release.

Links to HDF5 documentation can be found on The HDF5 web page:

     https://portal.hdfgroup.org/display/HDF5/HDF5

The official HDF5 releases can be obtained from:

     https://www.hdfgroup.org/downloads/hdf5/

     HDF5 binaries provided are fully tested with ZLIB and the free
     Open Source SZIP successor Libaec (with BSD license).
     The official ZLIB and SZIP/Libaec pages are at:

        ZLIB: http://www.zlib.net/
            http://www.zlib.net/zlib_license.html
        SZIP/Libaec: https://gitlab.dkrz.de/k202009/libaec
            https://gitlab.dkrz.de/k202009/libaec/-/blob/master/Copyright.txt

Changes from Release to Release and New Features in the HDF5-1.10.x release series
can be found at:

     https://portal.hdfgroup.org/display/HDF5/HDF5+Application+Developer%27s+Guide

If you have any questions or comments, please send them to the HDF Help Desk:

     help@hdfgroup.org


CONTENTS

- New Features
- Support for new platforms and languages
- Bug Fixes since HDF5-1.10.6
- Supported Platforms
- Tested Configuration Features Summary
- More Tested Platforms
- Known Problems
- CMake vs. Autotools installations


New Features
============

    Configuration:
    -------------
    - Disable memory sanity checks in the Autotools in release branches

      The library can be configured to use internal memory sanity checking,
      which replaces C API calls like malloc(3) and free(3) with our own calls
      which add things like heap canaries. These canaries can cause problems
      when external filter plugins reallocate canary-marked buffers.

      For this reason, the default will be to not use the memory allocation
      sanity check feature in release branches (e.g., hdf5_1_10_7).
      Debug builds in development branches (e.g., develop, hdf5_1_10) will
      still use them by default.

      This change only affects Autotools debug builds. Non-debug autotools
      builds and all CMake builds do not enable this feature by default.

      (DER - 2020/08/19)

    - Add file locking configure and CMake options

      HDF5 1.10.0 introduced a file locking scheme, primarily to help
      enforce SWMR setup. Formerly, the only user-level control of the scheme
      was via the HDF5_USE_FILE_LOCKING environment variable.

      This change introduces configure-time options that control whether
      or not file locking will be used and whether or not the library
      ignores errors when locking has been disabled on the file system
      (useful on some HPC Lustre installations).

      In both the Autotools and CMake, the settings have the effect of changing
      the default property list settings (see the H5Pset/get_file_locking()
      entry, below).

      The yes/no/best-effort file locking configure setting has also been
      added to the libhdf5.settings file.

      Autotools:

        An --enable-file-locking=(yes|no|best-effort) option has been added.

        yes:          Use file locking.
        no:           Do not use file locking.
        best-effort:  Use file locking and ignore "disabled" errors.

      CMake:

        Two self-explanatory options have been added:

        HDF5_USE_FILE_LOCKING
        HDF5_IGNORE_DISABLED_FILE_LOCKS

        Setting both of these to ON is the equivalent to the Autotools'
        best-effort setting.

      NOTE:
      The precedence order of the various file locking control mechanisms is:

        1) HDF5_USE_FILE_LOCKING environment variable (highest)

        2) H5Pset_file_locking()

        3) configure/CMake options (which set the property list defaults)

        4) library defaults (currently best-effort)

      (DER - 2020/07/30, HDFFV-11092)

    - CMake option to link the generated Fortran MOD files into the include
      directory.

      The Fortran generation of MOD files by a Fortran compile can produce
      different binary files between SHARED and STATIC compiles with different
      compilers and/or different platforms. Note that it has been found that
      different versions of Fortran compilers will produce incompatible MOD
      files. Currently, CMake will locate these MOD files in subfolders of
      the include directory and add that path to the Fortran library target
      in the CMake config file, which can be used by the CMake find library
      process. For other build systems using the binary from a CMake install,
      a new CMake configuration can be used to copy the pre-chosen version
      of the Fortran MOD files into the install include directory.

      The default will depend on the configuration of
      BUILD_STATIC_LIBS and BUILD_SHARED_LIBS:
            YES                   YES         Default to SHARED
            YES                   NO          Default to STATIC
            NO                    YES         Default to SHARED
            NO                    NO          Default to SHARED
      The defaults can be overridden by setting the config option
         HDF5_INSTALL_MOD_FORTRAN to one of NO, SHARED, or STATIC

      (ADB - 2020/07/09, HDFFV-11116)

    - CMake option to use AEC (open source SZip) library instead of SZip

      The open source AEC library is a replacement library for SZip. In
      order to use it for hdf5, the libaec CMake source was changed to add
      "-fPIC" and exclude test files. A new option USE_LIBAEC is required
      to compensate for the different files produced by AEC build.

      Autotools does not build the compression libraries within hdf5 builds,
      but will use an installed libaec when configured as before with the
      option --with-libsz=<path to libaec directory>.

      (ADB - 2020/04/22, OESS-65)

    - CMake ConfigureChecks.cmake file now uses CHECK_STRUCT_HAS_MEMBER

      Some handcrafted tests in HDFTests.c have been removed and the CMake
      CHECK_STRUCT_HAS_MEMBER module has been used.

      (ADB - 2020/03/24, TRILAB-24)

    - Both build systems use same set of warnings flags

      GNU C, C++ and gfortran warnings flags were moved to files in a config
      sub-folder named gnu-warnings. Flags that only are available for a specific
      version of the compiler are in files named with that version.
      Clang C warnings flags were moved to files in a config sub-folder
      named clang-warnings.
      Intel C, Fortran warnings flags were moved to files in a config sub-folder
      named intel-warnings.

      There are flags in named "error-xxx" files with warnings that may
      be promoted to errors. Some source files may still need fixes.

      There are also pairs of files named "developer-xxx" and "no-developer-xxx"
      that are chosen by the CMake option:HDF5_ENABLE_DEV_WARNINGS or the
      configure option:--enable-developer-warnings.

      In addition, CMake no longer applies these warnings for examples.

      (ADB - 2020/03/24, TRILAB-192)

    - Update CMake minimum version to 3.12

      Updated CMake minimum version to 3.12 and added version checks
      for Windows features.

      (ADB - 2020/02/05, TRILABS-142)

    - Fixed CMake include properties for Fortran libraries

      Corrected the library properties for Fortran to use the
      correct path for the Fortran module files.

      (ADB - 2020/02/04, HDFFV-11012)

    - Added common warnings files for gnu and intel

      Added warnings files to use one common set of flags
      during configure for both autotools and CMake build
      systems. The initial implementation only affects a
      general set of flags for gnu and intel compilers.

      (ADB - 2020/01/17)

    - Added new options to CMake for control of testing

      Added CMake options (default ON);
          HDF5_TEST_SERIAL AND/OR HDF5_TEST_PARALLEL
          combined with:
            HDF5_TEST_TOOLS
            HDF5_TEST_EXAMPLES
            HDF5_TEST_SWMR
            HDF5_TEST_FORTRAN
            HDF5_TEST_CPP
            HDF5_TEST_JAVA

      (ADB - 2020/01/15, HDFFV-11001)

    - Added Clang sanitizers to CMake for analyzer support if compiler is clang.

      Added CMake code and files to execute the Clang sanitizers if
      HDF5_ENABLE_SANITIZERS is enabled and the USE_SANITIZER option
      is set to one of the following:
          Address
          Memory
          MemoryWithOrigins
          Undefined
          Thread
          Leak
          'Address;Undefined'

      (ADB - 2019/12/12, TRILAB-135)


    Library:
    --------
    - Add metadata cache optimization to reduce skip list usage

      On file flush or close, the metadata cache attempts to write out
      all dirty entries in increasing address order.  To do this, it needs
      an address sorted list of metadata entries.  Further, since flushing
      one metadata cache entry can dirty another, this list must support
      efficient insertion and deletion.

      The metadata cache uses a skip list of all dirty entries for this
      purpose.  Before this release, this skip list was maintained at all
      times.  However, since profiling indicates that this imposes a
      significant cost, we now construct and maintain the skip list only
      when needed.  Specifically, we enable the skip list and load it with
      a list of all dirty entries in the metadata cache just before a flush,
      and disable it after the flush.

      (JRM - 2020/08/17, HDFFV-11034)

    - Add BEST_EFFORT value to HDF5_USE_FILE_LOCKING environment variable

      This change adds a BEST_EFFORT to the TRUE/FALSE, 1/0 settings that
      were previously accepted. This option turns on file locking but
      ignores locking errors when the library detects that file locking
      has been disabled on a file system (useful on some HPC Lustre
      installations).

      The capitalization of BEST_EFFORT is mandatory.

      See the configure option discussion for HDFFV-11092 (above) for more
      information on the file locking feature and how it's controlled.

      (DER - 2020/07/30, HDFFV-11092)


    - Add H5Pset/get_file_locking() API calls

      This change adds new API calls which can be used to set or get the
      file locking parameters. The single API call sets both the "use file
      locking" flag and the "ignore disabled file locking" flag.

      When opening a file multiple times without closing, the file MUST be
      opened with the same file locking settings. Opening a file with different
      file locking settings will fail (this is similar to the behavior of
      H5Pset_fclose_degree()).

      See the configure option discussion for HDFFV-11092 (above) for more
      information on the file locking feature and how it's controlled.

      (DER - 2020/07/30, HDFFV-11092)

    - Add Mirror VFD

      Use TCP/IP sockets to perform write-only (W/O) file I/O on a remote
      machine. Must be used in conjunction with the Splitter VFD.

      (JOS - 2020/03/13, TBD)

    - Add Splitter VFD

      Maintain separate R/W and W/O channels for "concurrent" file writes
      to two files using a single HDF5 file handle.

      (JOS - 2020/03/13, TBD)

    - Fixed an assertion failure in the parallel library when collectively
      filling chunks. As it is required that chunks be written in
      monotonically non-decreasing order of offset in the file, this assertion
      was being triggered when the list of chunk file space allocations being
      passed to the collective chunk filling routine was not sorted according
      to this particular requirement.

      The addition of a sort of the out of order chunks trades a bit of
      performance for the elimination of this assertion and of any complaints
      from MPI implementations about the file offsets used being out of order.

      (JTH - 2019/10/07)

    Fortran Library:
    ----------------
    - Add wrappers for H5Pset/get_file_locking() API calls

      h5pget_file_locking_f()
      h5pset_file_locking_f()

      See the configure option discussion for HDFFV-11092 (above) for more
      information on the file locking feature and how it's controlled.

      (DER - 2020/07/30, HDFFV-11092)

    - Added new Fortran parameters:

        H5F_LIBVER_ERROR_F
        H5F_LIBVER_NBOUNDS_F
        H5F_LIBVER_V18_F
        H5F_LIBVER_V110_F

    - Added new Fortran API: h5pget_libver_bounds_f

      (MSB - 2020/02/11, HDFFV-11018)

    C++ Library:
    ------------
    - Add wrappers for H5Pset/get_file_locking() API calls

      FileAccPropList::setFileLocking()
      FileAccPropList::getFileLocking()

      See the configure option discussion for HDFFV-11092 (above) for more
      information on the file locking feature and how it's controlled.

      (DER - 2020/07/30, HDFFV-11092)

    Java Library:
    ----------------
    - Add wrappers for H5Pset/get_file_locking() API calls

      H5Pset_file_locking()
      H5Pget_use_file_locking()
      H5Pget_ignore_disabled_file_locking()

      Unlike the C++ and Fortran wrappers, there are separate getters for the
      two file locking settings, each of which returns a boolean value.

      See the configure option discussion for HDFFV-11092 (above) for more
      information on the file locking feature and how it's controlled.

      (DER - 2020/07/30, HDFFV-11092)

    Tools:
    ------
    - h5repack added options to control how external links are handled.

      Currently h5repack preserves external links and cannot copy and merge
      data from the external files. Two options, merge and prune, were added to
      control how to merge data from an external link into the resulting file.
       --merge             Follow external soft link recursively and merge data.
       --prune             Do not follow external soft links and remove link.
       --merge --prune     Follow external link, merge data and remove dangling link.

      (ADB - 2020/08/05, HDFFV-9984)

    High-Level APIs:
    ---------------
    - None

    C Packet Table API
    ------------------
    - None

    Internal header file
    --------------------
    - None

    Documentation
    -------------
    - None


Support for new platforms, languages and compilers.
=======================================
    - None


Bug Fixes since HDF5-1.10.6 release
==================================

    Library
    -------
    - Fix bug and simplify collective metadata write operation when some ranks
        have no entries to contribute.  This fixes parallel regression test
        failures with IBM SpectrumScale MPI on the Summit system at ORNL.

      (QAK - 2020/09/02)

    - Avoid setting up complex MPI types with 0-length vectors, which some
        MPI implementations don't handle well.  (In particular, IBM
        SpectrumScale MPI on the Summit system at ORNL)

      (QAK - 2020/08/21)

    - Fixed use-of-uninitialized-value error

      Appropriate initialization of local structs was added to remove the
      use-of-uninitialized-value errors reported by MemorySanitizer.

      (BMR - 2020/8/13, HDFFV-11101)

    - Creation of dataset with optional filter

      When the combination of type, space, etc doesn't work for filter
      and the filter is optional, it was supposed to be skipped but it was
      not skipped and the creation failed.

      A fix is applied to allow the creation of a dataset in such
      situation, as specified in the user documentation.

      (BMR - 2020/8/13, HDFFV-10933)

    - Explicitly declared dlopen to use RTLD_LOCAL

      dlopen documentation states that if neither RTLD_GLOBAL nor
      RTLD_LOCAL are specified, then the default behavior is unspecified.
      The default on linux is usually RTLD_LOCAL while macos will default
      to RTLD_GLOBAL.

      (ADB - 2020/08/12, HDFFV-11127)

    - Fixed issues CVE-2018-13870 and CVE-2018-13869

      When a buffer overflow occurred because a name length was corrupted
      and became very large, h5dump crashed on memory access violation.

      A check for reading past the end of the buffer was added to multiple
      locations to prevent the crashes and h5dump now simply fails with an
      error message when this error condition occurs.

      (BMR - 2020/7/31, HDFFV-11120 and HDFFV-11121)

    - H5Sset_extent_none() sets the dataspace class to H5S_NO_CLASS which
      causes asserts/errors when passed to other dataspace API calls.

      H5S_NO_CLASS is an internal class value that should not have been
      exposed via a public API call.

      In debug builds of the library, this can cause asserts to trip. In
      non-debug builds, it will produce normal library errors.

      The new library behavior is for H5Sset_extent_none() to convert
      the dataspace into one of type H5S_NULL, which is better handled
      by the library and easier for developers to reason about.

      (DER - 2020/07/27, HDFFV-11027)

    - Fixed the segmentation fault when reading attributes with multiple threads

      It was reported that the reading of attributes with variable length string
      datatype will crash with segmentation fault particularly when the number
      of threads is high (>16 threads).  The problem was due to the file pointer
      that was set in the variable length string datatype for the attribute.
      That file pointer was already closed when the attribute was accessed.

      The problem was fixed by setting the file pointer to the current opened
      file pointer when the attribute was accessed.  Similar patch up was done
      before when reading dataset with variable length string datatype.

      (VC - 2020/07/13, HDFFV-11080)

    -  Fixed issue CVE-2018-17438

      A division by zero was discovered in H5D__select_io() of H5Dselect.c.
        https://security-tracker.debian.org/tracker/CVE-2018-17438

      A check was added to protect against division by zero.  When such
      situation occurs again, the normal HDF5 error handling will be invoked,
      instead of segmentation fault.

      (BMR, DER - 2020/07/09, HDFFV-10587)

    - Fixed CVE-2018-17435

      The tool h52gif produced a segfault when the size of an attribute message
      was corrupted and caused a buffer overflow.

      The problem was fixed by verifying the attribute message's size against the
      buffer size before accessing the buffer.  h52gif was also fixed to display
      the failure instead of silently exiting after the segfault was eliminated.

      (BMR - 2020/6/19, HDFFV-10591)

    - Don't allocate an empty (0-dimensioned) chunked dataset's chunk
      index, until the dataset's dimensions are increased.

      (QAK - 2020/05/07)

    Configuration
    -------------
    - Stopped addition of szip header and include directory path for
      incompatible libsz

      szlib.h is the same for both 32-bit and 64-bit szip, and the header file
      and its path were added to the HDF5 binary even though the configure
      check of a function in libsz later failed and szip compression was not
      enabled.  The header file and include path are now added only when the
      libsz function passes the configure check.

      (LRK - 2020/08/17, HDFFV-10830)

    - Added -fsanitize=address autotools configure option for Clang compiler

      Clang sanitizer options were also added for Clang compilers with CMake.

      (LRK, 2020/08/05, HDFFV-10836)

    - Updated testh5cc.sh.in for functions versioned in HDF5 1.10.

      testh5cc.sh previously tested that the correct version of a function
      versioned in HDF5 1.6 or 1.8 was compiled when one of
      H5_NO_DEPRECATED_SYMBOLS or H5_USE_16_API_DEFAULT were defined.  This
      test was extended for additional testing with H5_USE_18_API_DEFAULT.

      (LRK, 2020/06/22, HDFFV-11000)

    - Fixed CMake include properties for Fortran libraries

      Corrected the library properties for Fortran to use the
      correct path for the Fortran module files.

      (ADB - 2020/02/04, HDFFV-11012)

    Performance
    -------------
    - None

    Java Library:
    ----------------
    - None

    Fortran
    --------
    - Corrected INTERFACE INTENT(IN) to INTENT(OUT) for buf_size in h5fget_file_image_f.

      (MSB - 2020/2/18, HDFFV-11029)

    - Fixed configure issue when building HDF5 with NAG Fortran 7.0.

      HDF5 now accounts for the addition of half-precision floating-point
      in NAG 7.0 with a KIND=16.

      (MSB - 2020/02/28, HDFFV-11033)

    Tools
    -----
    - The tools library was updated by standardizing the error stack process.

      General sequence is:
          h5tools_setprogname(PROGRAMNAME);
          h5tools_setstatus(EXIT_SUCCESS);
          h5tools_init();
          ... process the command-line (check for error-stack enable) ...
          h5tools_error_report();
          ... (do work) ...
          h5diff_exit(ret);

      (ADB - 2020/07/20, HDFFV-11066)

    - h5diff fixed a command line parsing error.

      h5diff would ignore the argument to -d (delta) if it is smaller than DBL_EPSILON.
      The macro H5_DBL_ABS_EQUAL was removed and a direct value comparison was used.

      (ADB - 2020/07/20, HDFFV-10897)

    - h5diff added a command line option to ignore attributes.

      h5diff would ignore all objects with a supplied path if the exclude-path argument is used.
      Adding the exclude-attribute argument will only eclude attributes, with the supplied path,
      from comparison.

      (ADB - 2020/07/20, HDFFV-5935)

    - h5diff added another level to the verbose argument to print filenames.

      Added verbose level 3 that is level 2 plus the filenames. The levels are:
          0 : Identical to '-v' or '--verbose'
          1 : All level 0 information plus one-line attribute status summary
          2 : All level 1 information plus extended attribute status report
          3 : All level 2 information plus file names

      (ADB - 2020/07/20, HDFFV-10005)

    - h5repack was fixed to repack the reference attributes properly.
      The code line that checks if the update of reference inside a compound
      datatype is misplaced outside the code block loop that carries out the
      check. In consequence, the next attribute that is not the reference
      type was repacked again as the reference type and caused the failure of
      repacking. The fix is to move the corresponding code line to the correct
      code block.

      (KY -2020/02/10, HDFFV-11014)

    High-Level APIs:
    ------
    - The H5DSis_scale function was updated to return "not a dimension scale" (0)
      instead of failing (-1), when CLASS or DIMENSION_SCALE attributes are
      not written according to Dimension Scales Specification.

     (EIP - 2020/08/12, HDFFV-10436)

    Fortran High-Level APIs:
    ------
    - None

    Documentation
    -------------
    - None

    F90 APIs
    --------
    - None

    C++ APIs
    --------
    - None

    Testing
    -------
    - Stopped java/test/junit.sh.in installing libs for testing under ${prefix}

      Lib files needed are now copied to a subdirectory in the java/test
      directory, and on Macs the loader path for libhdf5.xxxs.so is changed
      in the temporary copy of libhdf5_java.dylib.

      (LRK, 2020/7/2, HDFFV-11063)


Supported Platforms
===================

    Linux 3.10.0-1127.10.1.el7    gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-39)
    #1 SMP ppc64 GNU/Linux        g++ (GCC) 4.8.5 20150623 (Red Hat 4.8.5-39)
    (echidna)                     GNU Fortran (GCC) 4.8.5 20150623 (Red Hat 4.8.5-39)

    Linux 2.6.32-754.31.1.el6     IBM XL C/C++ V13.1
    #1 SMP ppc64 GNU/Linux        IBM XL Fortran V15.1
    (ostrich)

    Linux 3.10.0-327.18.2.el7     GNU C (gcc), Fortran (gfortran), C++ (g++)
    #1 SMP x86_64 GNU/Linux       compilers:
    (jelly/kituo/moohan)          Version 4.8.5 20150623 (Red Hat 4.8.5-4)
                                    Version 4.9.3, Version 5.3.0, Version 6.3.0,
                                    Version 7.2.0, Version 8.3.0, Version 9.1.0
                                  Intel(R) C (icc), C++ (icpc), Fortran (icc)
                                  compilers:
                                     Version 17.0.0.098 Build 20160721
                                  MPICH 3.3 compiled with GCC 7.2.0
                                  OpenMPI 4.0.0 compiled with GCC 7.2.0

    SunOS 5.11 11.4.5.12.5.0      Sun C 5.15 SunOS_sparc 2017/05/30
    32- and 64-bit                Studio 12.6 Fortran 95 8.8 SunOS_sparc 2017/05/30
    (hedgehog)                    Sun C++ 5.15 SunOS_sparc 2017/05/30

    Windows 7 x64                 Visual Studio 2015 w/ Intel C, Fortran 2018 (cmake)

    Windows 10 x64                Visual Studio 2015 w/ Intel Fortran 18 (cmake)
                                  Visual Studio 2017 w/ Intel Fortran 19 (cmake)
                                  Visual Studio 2019 w/ Intel Fortran 19 (cmake)
                                  Visual Studio 2019 w/ MSMPI 10.1 (cmake)

    macOS Mojave 10.14.6          Apple LLVM version 10.0.1 (clang-1001.0.46.4)
    64-bit                        gfortran GNU Fortran (GCC) 6.3.0
    (swallow)                     Intel icc/icpc/ifort version 19.0.4.233 20190416

Tested Configuration Features Summary
=====================================

    In the tables below
          y   = tested
          n   = not tested in this release
          C   = Cluster
          W   = Workstation
          x   = not working in this release
          dna = does not apply
          ( ) = footnote appears below second table
          <blank> = testing incomplete on this feature or platform

Platform                              C         F90/   F90      C++  zlib  SZIP
                                      parallel  F2003  parallel
Solaris2.11 32-bit                      n        y/y    n        y    y     y
Solaris2.11 64-bit                      n        y/n    n        y    y     y
Windows 7 x64                           y        y/y    y        y    y     y
Windows 10                              y        y/y    n        y    y     y
Windows 10 x64                          y        y/y    n        y    y     y
MacOS Sierra 10.12.6 64-bit             n        y/y    n        y    y     y
MacOS High Sierra 10.13.6 64-bit        n        y/y    n        y    y     y
MacOS Mojave 10.14.6 64-bit             n        y/y    n        y    y     y
CentOS 7.2 Linux 3.10.0 x86_64 PGI      n        y/y    n        y    y     y
CentOS 7.2 Linux 3.10.0 x86_64 GNU      y        y/y    y        y    y     y
CentOS 7.2 Linux 3.10.0 x86_64 Intel    n        y/y    n        y    y     y
Linux 2.6.32-754.31.1.el6.ppc64 XL      n        y/y    n        y    y     y


Platform                                 Shared  Shared    Shared    Thread-
                                         C libs  F90 libs  C++ libs  safe
Solaris2.11 32-bit                         y       y         y         y
Solaris2.11 64-bit                         y       y         y         y
Windows 7 x64                              y       y         y         y
Windows 10                                 y       y         y         y
Windows 10 x64                             y       y         y         y
MacOS Sierra 10.12.6 64-bit                y       n         y         y
MacOS High Sierra 10.13.6 64-bit           y       n         y         y
MacOS Mojave 10.14.6 64-bit                y       n         y         y
CentOS 7.2 Linux 3.10.0 x86_64 PGI         y       y         y         n
CentOS 7.2 Linux 3.10.0 x86_64 GNU         y       y         y         y
CentOS 7.2 Linux 3.10.0 x86_64 Intel       y       y         y         n
Linux 2.6.32-754.31.1.el6.ppc64 XL         y       y         y         n

Compiler versions for each platform are listed in the preceding
"Supported Platforms" table.


More Tested Platforms
=====================
The following platforms are not supported but have been tested for this release.

    Linux 2.6.32-573.22.1.el6    GNU C (gcc), Fortran (gfortran), C++ (g++)
    #1 SMP x86_64 GNU/Linux       compilers:
    (platypus)                       Version 4.4.7 20120313
                                     Version 4.9.3, 5.3.0, 6.2.0
                                  PGI C, Fortran, C++ for 64-bit target on
                                  x86-64;
                                     Version 19.10-0
                                  MPICH 3.1.4 compiled with GCC 4.9.3

    Linux 2.6.32-754.31.1.el6     gcc (GCC) 4.4.7 20120313 (Red Hat 4.4.7-18)
    #1 SMP ppc64 GNU/Linux        g++ (GCC) 4.4.7 20120313 (Red Hat 4.4.7-18)
    (ostrich)                     GNU Fortran (GCC) 4.4.7 20120313 (Red Hat 4.4.7-18)

    Linux 3.10.0-327.18.2.el7     GNU C (gcc) and C++ (g++) compilers
    #1 SMP x86_64 GNU/Linux          Version 4.8.5 20150623 (Red Hat 4.8.5-4)
    (jelly)                       with NAG Fortran Compiler Release 6.1(Tozai)
                                  GCC Version 7.1.0
                                  OpenMPI 2.1.6-GCC-7.2.0-2.29,
                                     3.1.3-GCC-7.2.0-2.29
                                  Intel(R) C (icc) and C++ (icpc) compilers
                                     Version 17.0.0.098 Build 20160721
                                  with NAG Fortran Compiler Release 6.1(Tozai)

    Linux 3.10.0-327.10.1.el7     MPICH 3.1.4 compiled with GCC 4.9.3
    #1 SMP x86_64 GNU/Linux
    (moohan)

    Linux-3.10.0-1127.0.0.1chaos  openmpi-4.0.0
    #1 SMP x86_64 GNU/Linux           clang/3.9.0, 8.0.1
    (quartz)                          gcc/7.3.0, 8.1.0
                                      intel/16.0.4

    Linux-4.14.0-115.10.1.1       spectrum-mpi/rolling-release
    #1 SMP ppc64le GNU/Linux          clang/coral-2018.08.08
    (lassen)                          gcc/7.3.1
                                      xl/2019.02.07

    Linux-4.12.14-150.52-default  cray-mpich/7.7.10
    #1 SMP x86_64 GNU/Linux           gcc/7.3.0, 8.2.0
    (cori)                            intel/19.0.3

    Linux-4.4.180-94.107-default  cray-mpich/7.7.6
    # 1SMP x86_64 GNU/Linux           gcc/7.2.0, 8.2.0
    (mutrino)                         intel/17.0.4, 18.0.2, 19.0.4

    Fedora 32 5.7.15-200.fc32.x86_64  Clang version 10.0.0 (Fedora 10.0.0-2.fc32)
    #1 SMP x86_64  GNU/Linux      GNU gcc (GCC) 10.2.1 20200723 (Red Hat 10.2.1-1)
                                  GNU Fortran (GCC) 10.2.1 20200723 (Red Hat 10.2.1)
                                     (cmake and autotools)

    Mac OS X El Capitan 10.11.6   Apple clang version 7.3.0 from Xcode 7.3
    64-bit                        gfortran GNU Fortran (GCC) 5.2.0
    (osx1011test)                 Intel icc/icpc/ifort version 16.0.2

    macOS Sierra 10.12.6          Apple LLVM version 9.0.0 (clang-900.39.2)
    64-bit                        gfortran GNU Fortran (GCC) 7.4.0
    (kite)                        Intel icc/icpc/ifort version 17.0.2

    macOS High Sierra 10.13.6     Apple LLVM version 10.0.0 (clang-1000.10.44.4)
    64-bit                        gfortran GNU Fortran (GCC) 6.3.0
    (bear)                        Intel icc/icpc/ifort version 19.0.4.233 20190416

    SunOS 5.11 11.3               Sun C 5.15 SunOS_sparc
    32- and 64-bit                Sun Fortran 95 8.8 SunOS_sparc
    (emu)                         Sun C++ 5.15 SunOS_sparc


Known Problems
==============
    CMake files do not behave correctly with paths containing spaces.
    Do not use spaces in paths because the required escaping for handling spaces
    results in very complex and fragile build files.
    ADB - 2019/05/07

    At present, metadata cache images may not be generated by parallel
    applications.  Parallel applications can read files with metadata cache
    images, but since this is a collective operation, a deadlock is possible
    if one or more processes do not participate.

    Two tests fail attempting collective writes with OpenMPI 3.0.0/GCC-7.2.0-2.29:
        testphdf5 (ecdsetw, selnone, cchunk1, cchunk3, cchunk4, and actualio)
        t_shapesame (sscontig2)

    CPP ptable test fails on both VS2017 and VS2019 with Intel compiler, JIRA
    issue: HDFFV-10628.  This test will pass with VS2015 with Intel compiler.

    Known problems in previous releases can be found in the HISTORY*.txt files
    in the HDF5 source. Please report any new problems found to
    help@hdfgroup.org.


CMake vs. Autotools installations
=================================
While both build systems produce similar results, there are differences.
Each system produces the same set of folders on linux (only CMake works
on standard Windows); bin, include, lib and share. Autotools places the
COPYING and RELEASE.txt file in the root folder, CMake places them in
the share folder.

The bin folder contains the tools and the build scripts. Additionally, CMake
creates dynamic versions of the tools with the suffix "-shared". Autotools
installs one set of tools depending on the "--enable-shared" configuration
option.
  build scripts
  -------------
  Autotools: h5c++, h5cc, h5fc
  CMake: h5c++, h5cc, h5hlc++, h5hlcc

The include folder holds the header files and the fortran mod files. CMake
the share folder.

The bin folder contains the tools and the build scripts. Additionally, CMake
places the fortran mod files into separate shared and static subfolders,
while Autotools places one set of mod files into the include folder. Because
CMake produces a tools library, the header files for tools will appear in
the include folder.

The lib folder contains the library files, and CMake adds the pkgconfig
subfolder with the hdf5*.pc files used by the bin/build scripts created by
the CMake build. CMake separates the C interface code from the fortran code by
creating C-stub libraries for each Fortran library. In addition, only CMake
installs the tools library. The names of the szip libraries are different
between the build systems.

The share folder will have the most differences because CMake builds include
a number of CMake specific files for support of CMake's find_package and support
for the HDF5 Examples CMake project.



%%%%1.10.6%%%%

HDF5 version 1.10.6 released on 2019-12-23
================================================================================


INTRODUCTION

This document describes the differences between this release and the previous
HDF5 release. It contains information on the platforms tested and known
problems in this release. For more details check the HISTORY*.txt files in the
HDF5 source.

Note that documentation in the links below will be updated at the time of each
final release.

Links to HDF5 documentation can be found on The HDF5 web page:

     https://portal.hdfgroup.org/display/HDF5/HDF5

The official HDF5 releases can be obtained from:

     https://www.hdfgroup.org/downloads/hdf5/

Changes from Release to Release and New Features in the HDF5-1.10.x release series
can be found at:

     https://portal.hdfgroup.org/display/HDF5/HDF5+Application+Developer%27s+Guide

If you have any questions or comments, please send them to the HDF Help Desk:

     help@hdfgroup.org


CONTENTS

- New Features
- Support for new platforms and languages
- Bug Fixes since HDF5-1.10.5
- Supported Platforms
- Tested Configuration Features Summary
- More Tested Platforms
- Known Problems
- CMake vs. Autotools installations


New Features
============

    Configuration:
    -------------
    - Update CMake for VS2019 support

      CMake added support for VS2019 in version 3.15. Changes to the CMake
      generator setting required changes to scripts. Also updated version
      references in CMake files as necessary.

      (ADB - 2019/11/18, HDFFV-10962)

    - Update CMake options to match new autotools options

      Add configure options (autotools - CMake):
            enable-asserts       HDF5_ENABLE_ASSERTS
            enable-symbols       HDF5_ENABLE_SYMBOLS
            enable-profiling     HDF5_ENABLE_PROFILING
            enable-optimization  HDF5_ENABLE_OPTIMIZATION
      In addition NDEBUG is no longer forced defined and relies on the CMake
      process.

      (ADB - 2019/10/07, HDFFV-100901, HDFFV-10637, TRILAB-97)

    - Update CMake tests to use FIXTURES

      CMake test fixtures allow setup/cleanup tests and other dependency
      requirements as properties for tests. This is more flexible for
      modern CMake code.

      (ADB - 2019/07/23, HDFFV-10529)

    - Windows PDB files are always installed

      There are build configuration or flag settings for Windows that may not
      generate PDB files. If those files are not generated then the install
      utility will fail because those PDB files are not found. An optional
      variable, DISABLE_PDB_FILES, was added to not install PDB files.

      (ADB - 2019/07/17, HDFFV-10424)

    - Add mingw CMake support with a toolchain file

      There have been a number of mingw issues that have been linked under
      HDFFV-10845. It has been decided to implement the CMake cross-compiling
      technique of toolchain files. We will use a linux platform with the mingw
      compiler stack for testing. Only the C language is fully supported, and
      the error tests are skipped. The C++ language works for static but shared
      builds have a shared library issue with the mingw Standard Exception Handling
      library, which is not available on Windows. Fortran has a common cross-compile
      problem with the fortran configure tests.

      (ADB - 2019/07/12, HDFFV-10845, HDFFV-10595)

    - Windows PDB files are installed incorrectly

      For static builds, the PDB files for windows should be installed next
      to the static libraries in the lib folder. Also the debug versions of
      libraries and PDB files are now correctly built using the default
      CMAKE_DEBUG_POSTFIX setting.

      (ADB - 2019/07/09, HDFFV-10581)

    - Add option to build only shared libs

      A request was made to prevent building static libraries and only build
      shared.  A new option was added to CMake, ONLY_SHARED_LIBS, which will
      skip building static libraries. Certain utility functions will build with
      static libs but are not published. Tests are adjusted to use the correct
      libraries depending on SHARED/STATIC settings.

      (ADB - 2019/06/12, HDFFV-10805)

    - Add options to enable or disable building tools and tests

      Configure options --enable-tests and --enable-tools were added for
      autotools configure.  These options are enabled by default, and can be
      disabled with either --disable-tests (or tools) or --enable-tests=no
      (or --enable-tools=no).  Build time is reduced ~20% when tools are
      disabled, 35% when tests are disabled, 45% when both are disabled.
      Re-enabling them after the initial build requires running configure
      again with the option(s) enabled.

      (LRK - 2019/06/12, HDFFV-9976)

    - Change tools tests to search the error stack

      There are some use cases which can cause the error stack of tools to be
      different then the expected output. These tests now use grepTest.cmake;
      this was changed to allow the error file to be searched for an expected string.

      (ADB - 2019/04/15, HDFFV-10741)


    Library:
    --------
    - Added S3 and HDFS Virtual File Drivers (VFDs) to HDF5

      These new VFDs have been introduced in HDF5-1.10.6.  Instructions to
      enable them when configuring HDF5 on Linux and Mac may be found at
      https://portal.hdfgroup.org/display/HDF5/Virtual+File+Drivers+-+S3+and+HDFS.

      Installing on Windows requires CMake 3.13 and the following additional setup.
            Install openssl library (with dev files);
            from "Shining Light Productions". msi package preferred.

            PATH should have been updated with the installation dir.
            set ENV variable OPENSSL_ROOT_DIR to the installation dir.
            set ENV variable OPENSSL_CONF to the cfg file, likely %OPENSSL_ROOT_DIR%\bin\openssl.cfg
            Install libcurl library (with dev files);
            download the latest released version using git: https://github.com/curl/curl.git

            Open a Visual Studio Command prompt
            change to the libcurl root folder
            run the "buildconf.bat" batch file
            change to the winbuild directory
            nmake /f Makefile.vc mode=dll MACHINE=x64
            copy libcurl-vc-x64-release-dll-ipv6-sspi-winssl dir to C:\curl (installation dir)
            set ENV variable CURL_ROOT to C:\curl (installation dir)
            update PATH ENV variable to %CURL_ROOT%\bin (installation bin dir).
            the aws credentials file should be in %USERPROFILE%\.aws folder
            set the ENV variable "HDF5_ROS3_TEST_BUCKET_URL=https://s3.us-east-2.amazonaws.com/hdf5ros3"

      (ADB - 2019/09/12, HDFFV-10854)

    C++ Library:
    ------------
    - Added new wrappers for H5Pset/get_create_intermediate_group()
        LinkCreatPropList::setCreateIntermediateGroup()
        LinkCreatPropList::getCreateIntermediateGroup()

      (BMR - 2019/04/22, HDFFV-10622)


    Java Library:
    ----------------
    - Fixed a failure in JUnit-TestH5P on 32-bit architectures

      (JTH - 2019/04/30)


Support for new platforms, languages and compilers.
=======================================
    - CMake added support for VS2019 in version 3.15. Updated scripts.

    - macOS 10.13.6 Darwin 17.7.0 with Apple clang LLVM version 10.0.0

    - macOS 10.14.6 Darwin 18.7.0 with Apple clang LLVM version 10.0.1


Bug Fixes since HDF5-1.10.5 release
==================================

    Library
    -------
    - Improved performance when creating a large number of small datasets by
      retrieving default property values from the API context instead of doing
      skip list searches. More work is required to achieve parity with HDF5 1.8.

      (CJH - 2019/12/10, HDFFV-10658)

    - Fixed user-created data access properties not existing in the property list
      returned by H5Dget_access_plist. Thanks to Steven Varga for submitting a
      reproducer and a patch.

      (CJH - 2019/12/9, HDFFV-10934)

    - Inappropriate linking with deprecated MPI C++ libraries

      HDF5 does not define *_SKIP_MPICXX in the public headers, so applications
      can inadvertently wind up linking to the deprecated MPI C++ wrappers.

      MPICH_SKIP_MPICXX and OMPI_SKIP_MPICXX have both been defined in H5public.h
      so this should no longer be an issue. HDF5 makes no use of the deprecated
      MPI C++ wrappers.

      (DER - 2019/09/17, HDFFV-10893)

    - fcntl(2)-based file locking incorrectly passed the lock argument struct
      instead of a pointer to the struct, causing errors on systems where
      flock(2) is not available.

      File locking is used when files are opened to enforce SWMR semantics. A
      lock operation takes place on all file opens unless the
      HDF5_USE_FILE_LOCKING environment variable is set to the string "FALSE".
      flock(2) is preferentially used, with fcntl(2) locks as a backup if
      flock(2) is unavailable on a system (if neither is available, the lock
      operation fails). On these systems, the file lock will often fail, which
      causes HDF5 to not open the file and report an error.

      This bug only affects POSIX systems. Win32 builds on Windows use a no-op
      locking call which always succeeds. Systems which exhibit this bug will
      have H5_HAVE_FCNTL defined but not H5_HAVE_FLOCK in the configure output.

      This bug affects HDF5 1.10.0 through 1.10.5.

      fcntl(2)-based file locking now correctly passes the struct pointer.

      (DER - 2019/08/27, HDFFV-10892)

    - Fixed a bug caused by a bad tag value when condensing object header
      messages

      There was an assertion failure when moving messages from running a
      user test program with library release HDF5 1.10.4. It was because
      the tag value (object header's address) was not set up when entering
      the library routine H5O__chunk_update_idx(), which eventually
      verifies the metadata tag value when protecting the object header.

      The problem was fixed by replacing FUNC_ENTER_PACKAGE in H5O__chunk_update_idx()
      with FUNC_ENTER_PACKAGE_TAG(oh->cache_info.addr) to set up the metadata tag.

      (VC - 2019/08/23, HDFFV-10873)

    - Fixed the test failure from test_metadata_read_retry_info() in
      test/swmr.c

      The test failure is due to an incorrect number of bins returned for
      retry info (info.nbins).  The # of bins expected for 101 read attempts
      is 3 instead of 2.  The routine H5F_set_retries() in src/H5Fint.c
      calculates the # of bins by first obtaining the log10 value for
      (read attempts - 1).  For PGI/19, the log10 value for 100 read attempts
      is 1.9999999999999998 instead of 2.00000.  When casting the log10 value
      to unsigned later on, the decimal part is chopped off causing the test
      failure.

      This was fixed by obtaining the rounded integer value (HDceil) for the
      log10 value of read attempts first before casting the result to unsigned.

      (VC - 2019/8/14, HDFFV-10813)

    - Fixed an issue when creating a file with non-default file space info
      together with library high bound setting to H5F_LIBVER_V18.

      When setting non-default file space info in fcpl via
      H5Pset_file_space_strategy() and then creating a file with both high and
      low library bounds set to H5F_LIBVER_V18 in fapl, the library succeeds in
      creating the file.  File creation should fail because the feature of
      setting non-default file space info does not exist in library release 1.8
      or earlier.

      This was fixed by setting and checking the proper version in the file
      space info message based on the library low and high bounds when creating
      and opening the HDF5 file.

      (VC - 2019/6/25, HDFFV-10808)

    - Fixed an issue where copying a version 1.8 dataset between files using
      H5Ocopy fails due to an incompatible fill version

      When using the HDF5 1.10.x H5Ocopy() API call to copy a version 1.8
      dataset to a file created with both high and low library bounds set to
      H5F_LIBVER_V18, the H5Ocopy() call will fail with the error stack indicating
      that the fill value version is out of bounds.

      This was fixed by changing the fill value message version to H5O_FILL_VERSION_3
      (from H5O_FILL_VERSION_2) for H5F_LIBVER_V18.

      (VC - 2019/6/14, HDFFV-10800)

    - Fixed a bug that would cause an error or cause fill values to be
      incorrectly read from a chunked dataset using the "single chunk" index if
      the data was held in cache and there was no data on disk.

      (NAF - 2019/03/06)

    - Fixed a bug that could cause an error or cause fill values to be
      incorrectly read from a dataset that was written to using H5Dwrite_chunk
      if the dataset was not closed after writing.

      (NAF - 2019/03/06, HDFFV-10716)

    - Fixed memory leak in scale offset filter

      In a special case where the MinBits is the same as the number of bits in
      the datatype's precision, the filter's data buffer was not freed, causing
      the memory usage to grow. In general the buffer was freed correctly.  The
      Minbits are the minimal number of bits to store the data values.  Please
      see the reference manual for H5Pset_scaleoffset for the details.

      (RL - 2019/3/4, HDFFV-10705)


    Configuration
    -------------
    - Correct option for default API version

      CMake options for default API version are not mutually exclusive.
      Change the multiple BOOL options to a single STRING option with the
      strings; v16, v18, v110.

      (ADB - 2019/08/12, HDFFV-10879)

    Tools
    -----
    - h5repack was fixed to repack datasets with external storage
      to other types of storage.

      New test added to repack files and verify the correct data using h5diff.

      (JS - 2019/09/25, HDFFV-10408)
      (ADB - 2019/10/02, HDFFV-10918)


Supported Platforms
===================

    Linux 2.6.32-696.20.1.el6.ppc64 gcc (GCC) 4.4.7 20120313 (Red Hat 4.4.7-23)
    #1 SMP ppc64 GNU/Linux        g++ (GCC) 4.4.7 20120313 (Red Hat 4.4.7-23)
    (ostrich)                     GNU Fortran (GCC) 4.4.7 20120313 (Red Hat 4.4.7-23)
                                  IBM XL C/C++ V13.1
                                  IBM XL Fortran V15.1

    Linux 3.10.0-327.10.1.el7   GNU C (gcc), Fortran (gfortran), C++ (g++)
    #1 SMP x86_64 GNU/Linux       compilers:
    (jelly/kituo/moohan)          Version 4.8.5 20150623 (Red Hat 4.8.5-4)
                                    Version 4.9.3, Version 5.2.0
                                  Intel(R) C (icc), C++ (icpc), Fortran (icc)
                                  compilers:
                                     Version 17.0.0.098 Build 20160721
                                  MPICH 3.1.4 compiled with GCC 4.9.3

    SunOS 5.11 32- and 64-bit     Sun C 5.12 SunOS_sparc
    (emu)                         Sun Fortran 95 8.6 SunOS_sparc
                                  Sun C++ 5.12 SunOS_sparc

    Windows 7                     Visual Studio 2015 w/ Intel Fortran 18 (cmake)

    Windows 7 x64                 Visual Studio 2015 w/ Intel C, Fortran 2018 (cmake)
                                  Visual Studio 2015 w/ MSMPI 8 (cmake)

    Windows 10                    Visual Studio 2015 w/ Intel Fortran 18 (cmake)

    Windows 10 x64                Visual Studio 2015 w/ Intel Fortran 18 (cmake)
                                  Visual Studio 2017 w/ Intel Fortran 19 (cmake)
                                  Visual Studio 2019 w/ Intel Fortran 19 (cmake)

    macOS 10.13.6, Darwin,        Apple clang LLVM version 10.0.0
    17.7.0, x86_64                gfortran GNU Fortran (GCC) 6.3.0
    (bear)                        Intel icc/icpc/ifort version 19.0.4

    macOS 10.14.6, Darwin         Apple clang LLVM version 10.0.1
    18.7.0, x86_64                gfortran GNU Fortran (GCC) 6.3.0
    (bobcat)                      Intel icc/icpc/ifort version 19.0.4


Tested Configuration Features Summary
=====================================

    In the tables below
          y   = tested
          n   = not tested in this release
          C   = Cluster
          W   = Workstation
          x   = not working in this release
          dna = does not apply
          ( ) = footnote appears below second table
          <blank> = testing incomplete on this feature or platform

Platform                              C         F90/   F90      C++  zlib  SZIP
                                      parallel  F2003  parallel
Solaris2.11 32-bit                      n        y/y    n        y    y     y
Solaris2.11 64-bit                      n        y/n    n        y    y     y
Windows 7                               y        y/y    n        y    y     y
Windows 7 x64                           y        y/y    y        y    y     y
Windows 7 Cygwin                        n        y/n    n        y    y     y
Windows 7 x64 Cygwin                    n        y/n    n        y    y     y
Windows 10                              y        y/y    n        y    y     y
Windows 10 x64                          y        y/y    n        y    y     y
Mac OS X Yosemite 10.10.5 64-bit        n        y/y    n        y    y     y
Mac OS X El Capitan 10.11.6 64-bit      n        y/y    n        y    y     y
MacOS High Sierra 10.13.6 64-bit        n        y/y    n        y    y     y
CentOS 7.2 Linux 3.10.0 x86_64 PGI      n        y/y    n        y    y     y
CentOS 7.2 Linux 3.10.0 x86_64 GNU      y        y/y    y        y    y     y
CentOS 7.2 Linux 3.10.0 x86_64 Intel    n        y/y    n        y    y     y
Linux 2.6.32-573.18.1.el6.ppc64         n        y/y    n        y    y     y


Platform                                 Shared  Shared    Shared    Thread-
                                         C libs  F90 libs  C++ libs  safe
Solaris2.11 32-bit                         y       y         y         y
Solaris2.11 64-bit                         y       y         y         y
Windows 7                                  y       y         y         y
Windows 7 x64                              y       y         y         y
Windows 7 Cygwin                           n       n         n         y
Windows 7 x64 Cygwin                       n       n         n         y
Windows 10                                 y       y         y         y
Windows 10 x64                             y       y         y         y
Mac OS X Yosemite 10.10.5 64-bit           y       y         y         y
Mac OS X El Capitan 10.11.6 64-bit         y       y         y         y
MacOS High Sierra 10.13.6 64-bit           y       y         y         y
CentOS 7.2 Linux 3.10.0 x86_64 PGI         y       y         y         n
CentOS 7.2 Linux 3.10.0 x86_64 GNU         y       y         y         y
CentOS 7.2 Linux 3.10.0 x86_64 Intel       y       y         y         n
Linux 2.6.32-573.18.1.el6.ppc64            y       y         y         n

Compiler versions for each platform are listed in the preceding
"Supported Platforms" table.


More Tested Platforms
=====================
The following configurations are not supported but have been tested for this release.

    Linux 2.6.32-754.11.1.el6     GNU C (gcc), Fortran (gfortran), C++ (g++)
    #1 SMP x86_64 GNU/Linux       compilers:
    (mayll/platypus)                 Version 4.4.7 20120313
                                     Version 4.9.3, 5.3.0, 6.2.0
                                  PGI C, Fortran, C++ for 64-bit target on
                                  x86-64;
                                     Version 17.10-0
                                  Intel(R) C (icc), C++ (icpc), Fortran (icc)
                                  compilers:
                                     Version 17.0.4.196 Build 20170411
                                  MPICH 3.1.4 compiled with GCC 4.9.3

    Linux 3.10.0-327.18.2.el7     GNU C (gcc) and C++ (g++) compilers
    #1 SMP x86_64 GNU/Linux          Version 4.8.5 20150623 (Red Hat 4.8.5-4)
    (jelly)                       with NAG Fortran Compiler Release 6.2(Chiyoda)
                                  GCC Version 7.1.0
                                  MPICH 3.2-GCC-4.9.3
                                  MPICH 3.2.1-GCC-7.2.0-2.29
                                  OpenMPI 2.1.5-GCC-7.2.0-2.29
                                  Intel(R) C (icc) and C++ (icpc) compilers
                                     Version 17.0.0.098 Build 20160721
                                  with NAG Fortran Compiler Release 6.2(Chiyoda)

    Linux 3.10.0-327.10.1.el7     MPICH 3.2 compiled with GCC 5.3.0
    #1 SMP x86_64 GNU/Linux
    (moohan)

    Linux 2.6.32-573.18.1.el6.ppc64  MPICH mpich 3.1.4 compiled with
    #1 SMP ppc64 GNU/Linux           IBM XL C/C++ for Linux, V13.1
    (ostrich)                        and IBM XL Fortran for Linux, V15.1

    Fedora30 5.3.11-200.fc30.x86_64
    #1 SMP x86_64  GNU/Linux      GNU gcc (GCC) 9.2.1 20190827 (Red Hat 9.2.1 20190827)
                                  GNU Fortran (GCC) 9.2.1 20190827 (Red Hat 9.2.1 20190827)
                                     (cmake and autotools)

    Mac OS X 10.11.6, Darwin,     Apple clang version 7.3.0 from Xcode 7.3
    15.6.0, x86-64                gfortran GNU Fortran (GCC) 5.2.0
    (osx1011test)                 Intel icc/icpc/ifort version 16.0.2

    macOS 10.12.6, Darwin,        Apple clang LLVM version 8.1.0 from Xcode 8.3
    16.6.0, x86_64                gfortran GNU Fortran (GCC) 7.1.0
    (kite)                        Intel icc/icpc/ifort version 17.0.2

    Windows 7 x64                 Visual Studio 2008


Known Problems
==============
    CMake files do not behave correctly with paths containing spaces.
    Do not use spaces in paths because the required escaping for handling spaces
    results in very complex and fragile build files.
    ADB - 2019/05/07

    At present, metadata cache images may not be generated by parallel
    applications.  Parallel applications can read files with metadata cache
    images, but since this is a collective operation, a deadlock is possible
    if one or more processes do not participate.

    Three tests fail with OpenMPI 3.0.0/GCC-7.2.0-2.29:
        testphdf5 (ecdsetw, selnone, cchunk1, cchunk3, cchunk4, and actualio)
        t_shapesame (sscontig2)
        t_pflush1/fails on exit
    The first two tests fail attempting collective writes.

    Parallel builds using OpenMPI 3.03 or later and romio fail several tests
    with collective writes or compression that will not fail when ompio is used
    instead of romio.  This can be done by adding "--mca io ompio" to the mpirun
    command.  For example, in autotools builds RUNPARALLEL can be set to
    "mpirun --mca io ompio -n 6" provided ompio is installed.

    CPP ptable test fails on VS2017 with Intel compiler, JIRA issue: HDFFV-10628.
    This test will pass with VS2015 with Intel compiler.

    Older MPI libraries such as OpenMPI 2.0.1 and MPICH 2.1.5 were tested
    while attempting to resolve the Jira issue: HDFFV-10540.
    The known problems of reading or writing > 2GBs when using MPI-2 was
    partially resolved with the MPICH library. The proposed support recognizes
    IO operations > 2GB and if the datatype is not a derived type, the library
    breaks the IO into chunks which can be input or output with the existing
    MPI 2 limitations, i.e. size reporting and function API size/count
    arguments are restricted to be 32 bit integers.  For derived types larger
    than 2GB, MPICH 2.1.5 fails while attempting to read or write data.
    OpenMPI in contrast, implements MPI-3 APIs even in the older releases
    and thus does not suffer from the 32 bit size limitation described here.
    OpenMPI releases prior to v3.1.3 appear to have other datatype issues however,
    e.g. within a single parallel test (testphdf5) the subtests (cdsetr, eidsetr)
    report data verification errors before eventually aborting.
    The most recent versions of OpenMPI (v3.1.3 or newer) have evidently
    resolved these isses and parallel HDF5 testing does not currently report
    errors though occasional hangs have been observed.

    Known problems in previous releases can be found in the HISTORY*.txt files
    in the HDF5 source. Please report any new problems found to
    help@hdfgroup.org.


CMake vs. Autotools installations
=================================
While both build systems produce similar results, there are differences.
Each system produces the same set of folders on linux (only CMake works
on standard Windows); bin, include, lib and share. Autotools places the
COPYING and RELEASE.txt file in the root folder, CMake places them in
the share folder.

The bin folder contains the tools and the build scripts. Additionally, CMake
creates dynamic versions of the tools with the suffix "-shared". Autotools
installs one set of tools depending on the "--enable-shared" configuration
option.
  build scripts
  -------------
  Autotools: h5c++, h5cc, h5fc
  CMake: h5c++, h5cc, h5hlc++, h5hlcc

The include folder holds the header files and the fortran mod files. CMake
places the fortran mod files into separate shared and static subfolders,
while Autotools places one set of mod files into the include folder. Because
CMake produces a tools library, the header files for tools will appear in
the include folder.

The lib folder contains the library files, and CMake adds the pkgconfig
subfolder with the hdf5*.pc files used by the bin/build scripts created by
the CMake build. CMake separates the C interface code from the fortran code by
creating C-stub libraries for each Fortran library. In addition, only CMake
installs the tools library. The names of the szip libraries are different
between the build systems.

The share folder will have the most differences because CMake builds include
a number of CMake specific files for support of CMake's find_package and support
for the HDF5 Examples CMake project.

%%%%1.10.5%%%%

HDF5 version 1.10.5 released on 2019-02-25
================================================================================


INTRODUCTION

This document describes the differences between this release and the previous
HDF5 release. It contains information on the platforms tested and known
problems in this release. For more details check the HISTORY*.txt files in the
HDF5 source.

Note that documentation in the links below will be updated at the time of each
final release.

Links to HDF5 documentation can be found on The HDF5 web page:

     https://portal.hdfgroup.org/display/HDF5/HDF5

The official HDF5 releases can be obtained from:

     https://www.hdfgroup.org/downloads/hdf5/

Changes from Release to Release and New Features in the HDF5-1.10.x release series
can be found at:

     https://portal.hdfgroup.org/display/HDF5/HDF5+Application+Developer%27s+Guide

If you have any questions or comments, please send them to the HDF Help Desk:

     help@hdfgroup.org


CONTENTS

- New Features
- Support for new platforms and languages
- Bug Fixes since HDF5-1.10.4
- Supported Platforms
- Tested Configuration Features Summary
- More Tested Platforms
- Known Problems
- CMake vs. Autotools installations


New Features
============

    Configuration:
    -------------
    - Cross compile on mutrino and other Cray XC40 systems.

      Added support for CMake options to use CrayLinuxEnvironment, craype-mic-knl
      module for building with craype-haswell module for configuration, and
      batch scripts in bin/batch for use with sbatch or bsub to run tests in
      batch jobs on compute nodes.  An instruction file README_HPC describing
      the use of these options was added in release_docs.

      (LRK - 2019/02/18, TRILABS-34)

    - Rework CMake command files to fix MPI testing.

      Added setup fixture to remove any test generated files and added DEPENDS
      to test properties to execute tests in order expected.

      (ADB - 2019/02/14, TRILABS-111)

    - Disable SZIP or ZLIB options if TGZ files are not available.

      Changed the TGZ option for SZip and ZLib to disable the options
      if the source tar.gz files are not found.

      (ADB - 2019/02/05, HDFFV-10697)

    - Added a new option to enable/disable using pread/pwrite instead of
      read/write in the sec2, log, and core VFDs.

      This option is enabled by default when pread/pwrite are detected.

      Autotools:    --enable-preadwrite
      CMake:        HDF5_ENABLE_PREADWRITE

      (DER - 2019/02/03, HDFFV-10696)

    - Rework CMake versioning for OSX platforms.

      Changed the current_version and compatibility_version flags from optional
      with HDF5_BUILD_WITH_INSTALL_NAME to always setting the flags for OSX.

      (ADB - 2019/01/22, HDFFV-10685)

    - Rework CMake command files to eliminate developer CMP005 warning

      Use variables without quotes in if () statements.

      (ADB - 2019/01/18, TILABS-105)

    - Rework CMake configure files to eliminate developer CMP0075 warning

      Renamed varname to HDF5_REQUIRED_LIBRARIES as the contents were not
      required for configuration. Also moved check includes calls to top of
      files.

      (ADB - 2019/01/03, HDFFV-10546)

    - Keep stderr and stdout separate in tests

      Changed test handling of output capture. Tests now keep the stderr
      output separate from the stdout output. It is up to the test to decide
      which output to check against a reference. Also added the option
      to grep for a string in either output.

      (ADB - 2018/12/12, HDFFV-10632)

    - Incorrectly installed private header files were removed from
      CMake installs.

      The CMake build files incorrectly flagged the following header files
      as public and installed them. They are private and will no longer be
      installed.

        HDF5 library private package files (H5Xpkg.h)
        H5Edefin.h
        H5Einit.h
        H5Eterm.h
        H5LTparse.h
        h5diff.h
        h5tools_dump.h
        h5tools.h
        h5tools_ref.h
        h5tools_str.h
        h5tools_utils.h
        h5trav.h

      (DER - 2018/10/26, HDFFV-10614, 10609)

    - Autotools installs now install H5FDwindows.h

      This is simply to align the installed header files between the
      autotools and CMake. H5FDwindows.h has no functionality on
      non-Windows systems.

      (DER - 2018/10/26, HDFFV-10614)


    Library:
    --------
    - The sec2, log, and core VFDs can now use pread/pwrite instead of
      read/write.

      pread and pwrite do not change the file offset, a feature that was
      requested by a user working with a multi-threaded application.

      The option to configure this feature is described above.

      (DER - 2019/02/03, HDFFV-10696)

    - Add ability to minimize dataset object headers.

      Creation of many, very small datasets resulted in extensive file bloat
      due to extra space in the dataset object headers -- this space is
      allocated by default to allow for the insertion of a small number of
      attributes within the object header and not require a continuation
      block, an unnecessary provision in the target use case.

      Inform the library to expect no attributes on created datasets, and to
      allocate the least space possible for the object headers.
      NOTE: A continuation block is created if attributes are added to a
      'minimized' dataset, which can reduce performance.
      NOTE: Some extra space is allocated for attributes essential to the
      correct behavior of the object header (store creation times, e.g.). This
      does not violate the design principle, as the space is calculated and
      allocated as needed at the time of dataset object header creation --
      unused space is not generated.
      New API calls:
      H5Fget_dset_no_attrs_hint
      H5Fset_dset_no_attrs_hint
      H5Pget_dset_no_attrs_hint
      H5Pset_dset_no_attrs_hint

      (JOS - 2019/01/04, TRILAB-45)

    - Added new chunk query functions

      The following public functions were added to discover information about
      the chunks in an HDF5 file.
        herr_t H5Dget_num_chunks(dset_id, fspace_id, *nchunks)
        herr_t H5Dget_chunk_info_by_coord(dset_id, *coord, *filter_mask, *addr, *size)
        herr_t H5Dget_chunk_info(dset_id, fspace_id, index, *coord, *filter_mask, *addr, *size)

      (BMR - 2018/11/07, HDFFV-10615)

    - Several empty public header files where removed from the distribution

      The following files were empty placeholders. They are for internal
      packages that are unlikely to ever have public functionality and have
      thus been removed.

        H5Bpublic.h
        H5B2public.h
        H5FSpublic.h
        H5HFpublic.h
        H5HGpublic.h
        H5HLpublic.h

      They were only installed in CMake builds.

      (DER - 2018/10/26, HDFFV-10614)


     Parallel Library:
    -----------------
    - Changed the default behavior in parallel when reading the same dataset in its entirety
      (i.e. H5S_ALL dataset selection) which is being read by all the processes collectively.
      The dataset must be contiguous, less than 2GB, and of an atomic datatype.
      The new behavior is the HDF5 library will use an MPI_Bcast to pass the data read from
      the disk by the root process to the remain processes in the MPI communicator associated
      with the HDF5 file.

      (MSB - 2019/01/02, HDFFV-10652)

    - All MPI-1 API calls have been replaced with MPI-2 equivalents.

      This was done to better support OpenMPI, as default builds no longer
      include MPI-1 support (as of OpenMPI 4.0).

      (DER - 2018/12/30, HDFFV-10566)

    Fortran Library:
    ----------------
    - Added wrappers for dataset object header minimization calls.
      (see the note for TRILAB-45, above)

      New API calls:

      h5fget_dset_no_attrs_hint_f
      h5fset_dset_no_attrs_hint_f
      h5pget_dset_no_attrs_hint_f
      h5pset_dset_no_attrs_hint_f

      (DER - 2019/01/09, TRILAB-45)

    - Added new Fortran derived type, c_h5o_info_t, which is interoperable with
      C's h5o_info_t. This is needed for callback functions which
      pass C's h5o_info_t data type definition.

      (MSB, 2019/01/08, HDFFV-10443)

    - Added new Fortran API, H5gmtime, which converts (C) 'time_t' structure
      to Fortran DATE AND TIME storage format.

      (MSB, 2019/01/08, HDFFV-10443)

    - Added new Fortran 'fields' optional parameter to: h5ovisit_f, h5oget_info_by_name_f,
      h5oget_info, h5oget_info_by_idx and h5ovisit_by_name_f.

      (MSB, 2019/01/08, HDFFV-10443)

    C++ Library:
    ------------
    - Added new function to the C++ interface

      Added wrapper for H5Ovisit2:
          H5Object::visit()

      (BMR - 2019/02/14, HDFFV-10532)


    Java Library:
    ----------------
    - Rewrote the JNI error handling to be much cleaner

      (JTH - 2019/02/12)

    - Add new functions to java interface

      Added wrappers for:
      H5Fset_libver_bounds
      H5Fget_dset_no_attrs_hint/H5Fset_dset_no_attrs_hint
      H5Pget_dset_no_attrs_hint/H5Pset_dset_no_attrs_hint

      (ADB - 2019/01/07, HDFFV-10664)

    - Fix java unit tests when Time is a natural number

      Time substitution in java/test/junit.sh.in doesn't
      handle the case when Time is a natural number. Fixed
      the regular expression.

      (ADB - 2019/01/07, HDFFV-10674)

    - Duplicate the data read/write functions of Datasets for Attributes.

      Region references could not be displayed for attributes as they could
      for datasets. Datasets had overloaded read and write functions for different
      datatypes that were not available for attributes. After adding similar
      functions, attribute region references work normally.

      (ADB - 2018/12/12, HDFVIEW-4)


    Tools:
    ------
    - The h5repart -family-to-sec2 argument was changed to -family-to-single

      In order to better support other single-file VFDs which could work with
      h5repart, the -family-to-sec2 argument was renamed to -family-to-single.
      This is just a name change and the functionality of the argument has not
      changed.

      The -family-to-sec2 argument has been kept for backwards-compatibility.
      This argument should be considered deprecated.

      (DER - 2018/11/14, HDFFV-10633)


Bug Fixes since HDF5-1.10.4 release
==================================

    Library
    -------
    - Fix hangs with collective metadata reads during chunked dataset I/O

      In the parallel library, it was discovered that when a particular
      sequence of operations following a pattern of:

      "write to chunked dataset" -> "flush file" -> "read from dataset"

      occurred with collective metadata reads enabled, hangs could be
      observed due to certain MPI ranks not participating in the collective
      metadata reads.

      To fix the issue, collective metadata reads are now disabled during
      chunked dataset raw data I/O.

      (JTH - 2019/02/11, HDFFV-10563, HDFFV-10688)

    - Performance issue when closing an object

      The slow down is due to the search of the "tag_list" to find
      out the "corked" status of an object and "uncork" it if so.

      Improve performance by skipping the search of the "tag_list"
      if there are no "corked" objects when closing an object.

      (VC - 2019/02/06)

    - Uninitialized bytes from a type conversion buffer could be written
      to disk in H5Dwrite calls where type conversion takes place
      and the type conversion buffer was created by the HDF5 library.

      When H5Dwrite is called and datatype conversion must be performed,
      the library will create a temporary buffer for type conversion if
      one is not provided by the user via H5Pset_buffer. This internal
      buffer is allocated via malloc and contains uninitialized data. In
      some datatype conversions (float to long double, possibly others),
      some of this uninitialized data could be written to disk.

      This was flagged by valgrind in the dtransform test and does not
      appear to be a common occurrence (it is flagged in one test out
      of the entire HDF5 test suite).

      Switching to calloc fixed the problem.

      (DER - 2019/02/03, HDFFV-10694)

    - There was missing protection against division by zero reported to
      The HDF Group as issue #CVE-2018-17434.

      Protection against division by zero was added to address the issue
      #CVE-2018-17434.

      (BMR - 2019/01/29, HDFFV-10586)

    - The issue CVE-2018-17437 was reported to The HDF Group

      Although CVE-2018-17437 reported a memory leak, the actual issue
      was invalid read. It was found that the attribute name length
      in an attribute message was corrupted, which caused the buffer
      pointer to be advanced too far and later caused an invalid read.

      A check was added to detect when the attribute name or its length
      was corrupted and report the potential of data corruption.

      (BMR - 2019/01/29, HDFFV-10588)

    - H5Ewalk did not stop when it was supposed to

      H5Ewalk was supposed to stop when the callback function stopped
      even though the errors in the stack were not all visited, but it
      did not.  This problem is now fixed.

      (BMR - 2019/01/29, HDFFV-10684)

    - Revert H5Oget_info* and H5Ovisit* functions

      In 1.10.3 new H5Oget_info*2 and H5Ovisit*2 functions were
      added for performance. Inadvertently, the original functions;
          H5Oget_info,
          H5Oget_info_by_name,
          H5Oget_info_by_idx,
          H5Ovisit,
          H5Ovisit_by_name
      were versioned to H5Oget_info*1 and H5Ovisit*1. This
      broke the API compatibility for a maintenance release. The
      original functions have been restored.

      (ADB - 2019/01/24, HDFFV-10686)

    - Fixed a potential invalid memory access and failure that could occur when
      decoding an unknown object header message (from a future version of the
      library).

      (NAF - 2019/01/07)

    - Deleting attributes in dense storage

      The library aborts with "infinite loop closing library" after
      attributes in dense storage are created and then deleted.

      When deleting the attribute nodes from the name index v2 B-tree,
      if an attribute is found in the intermediate B-tree nodes,
      which may be merged/redistributed in the process, we need to
      free the dynamically allocated spaces for the intermediate
      decoded attribute.

      (VC - 2018/12/26, HDFFV-10659)

    - There was missing protection against division by zero reported to
      The HDF Group as issue #CVE-2018-17233.

      Protection against division by zero was added to address the issue
      #CVE-2018-17233.  In addition, several similar occurrences in the same
      file were fixed as well.

      (BMR - 2018/12/23, HDFFV-10577)

    - Fixed an issue where the parallel filters tests would fail
      if zlib was not available on the system. Until support can
      be added in the tests for filters beyond gzip/zlib, the tests
      will be skipped if zlib is not available.

      (JTH - 2018/12/05)

    - A bug was discovered in the parallel library where an application
      would eventually consume all of the available MPI communicators
      when continually writing to a compressed dataset in parallel. This
      was due to internal copies of an HDF5 File Access Property List,
      which each contained a copy of the MPI communicator, not being
      closed at the end of each write operation. This problem was
      exacerbated by larger numbers of processors.

      (JTH - 2018/12/05, HDFFV-10629)


    Fortran
    --------
    - Fixed issue with Fortran not returning h5o_info_t field values
      meta_size%attr%index_size and  meta_size%attr%heap_size.

      (MSB, 2019/01/08, HDFFV-10443)

    - Added symbolic links libhdf5_hl_fortran.so to libhdf5hl_fortran.so and
      libhdf5_hl_fortran.a to libhdf5hl_fortran.a in hdf5/lib directory for
      autotools installs.  These were added to match the name of the files
      installed by cmake and the general pattern of hl lib files.  We will
      change the names of the installed lib files to the matching name in
      the next major release.

      (LRK - 2019/01/04, HDFFV-10596)

    - Made Fortran specific subroutines PRIVATE in generic procedures.

      Affected generic procedures were functions in H5A, H5D, H5P, H5R and H5T.

      (MSB, 2018/12/04, HDFFV-10511)


    Testing
    -------
    - Fixed a test failure in testpar/t_dset.c caused by
      the test trying to use the parallel filters feature
      on MPI-2 implementations.

      (JTH, 2019/2/7)


Supported Platforms
===================

    Linux 2.6.32-696.16.1.el6.ppc64 gcc (GCC) 4.4.7 20120313 (Red Hat 4.4.7-18)
    #1 SMP ppc64 GNU/Linux        g++ (GCC) 4.4.7 20120313 (Red Hat 4.4.7-18)
    (ostrich)                     GNU Fortran (GCC) 4.4.7 20120313 (Red Hat 4.4.7-18)
                                  IBM XL C/C++ V13.1
                                  IBM XL Fortran V15.1

    Linux 3.10.0-327.10.1.el7   GNU C (gcc), Fortran (gfortran), C++ (g++)
    #1 SMP x86_64 GNU/Linux       compilers:
    (kituo/moohan)                Version 4.8.5 20150623 (Red Hat 4.8.5-4)
                                    Version 4.9.3, Version 5.2.0
                                  Intel(R) C (icc), C++ (icpc), Fortran (icc)
                                  compilers:
                                     Version 17.0.0.098 Build 20160721
                                  MPICH 3.1.4 compiled with GCC 4.9.3

    SunOS 5.11 32- and 64-bit     Sun C 5.12 SunOS_sparc
    (emu)                         Sun Fortran 95 8.6 SunOS_sparc
                                  Sun C++ 5.12 SunOS_sparc

    Windows 7                     Visual Studio 2015 w/ Intel Fortran 16 (cmake)

    Windows 7 x64                 Visual Studio 2013
                                  Visual Studio 2015 w/ Intel Fortran 16 (cmake)
                                  Visual Studio 2015 w/ Intel C, Fortran 2018 (cmake)
                                  Visual Studio 2015 w/ MSMPI 8 (cmake)

    Windows 10                    Visual Studio 2015 w/ Intel Fortran 18 (cmake)

    Windows 10 x64                Visual Studio 2015 w/ Intel Fortran 18 (cmake)
                                  Visual Studio 2017 w/ Intel Fortran 18 (cmake)

    Mac OS X Yosemite 10.10.5     Apple clang/clang++ version 6.1 from Xcode 7.0
    64-bit                        gfortran GNU Fortran (GCC) 4.9.2
    (osx1010dev/osx1010test)      Intel icc/icpc/ifort version 15.0.3

    Mac OS X El Capitan 10.11.6   Apple clang/clang++ version 7.3.0 from Xcode 7.3
    64-bit                        gfortran GNU Fortran (GCC) 5.2.0
    (osx1011dev/osx1011test)      Intel icc/icpc/ifort version 16.0.2

    MacOS High Sierra 10.13.6     Apple LLVM version 10.0.0 (clang/clang++-1000.10.44.4)
    64-bit                        gfortran GNU Fortran (GCC) 8.3.0


Tested Configuration Features Summary
=====================================

    In the tables below
          y   = tested
          n   = not tested in this release
          C   = Cluster
          W   = Workstation
          x   = not working in this release
          dna = does not apply
          ( ) = footnote appears below second table
          <blank> = testing incomplete on this feature or platform

Platform                              C         F90/   F90      C++  zlib  SZIP
                                      parallel  F2003  parallel
Solaris2.11 32-bit                      n        y/y    n        y    y     y
Solaris2.11 64-bit                      n        y/n    n        y    y     y
Windows 7                               y        y/y    n        y    y     y
Windows 7 x64                           y        y/y    y        y    y     y
Windows 7 Cygwin                        n        y/n    n        y    y     y
Windows 7 x64 Cygwin                    n        y/n    n        y    y     y
Windows 10                              y        y/y    n        y    y     y
Windows 10 x64                          y        y/y    n        y    y     y
Mac OS X Yosemite 10.10.5 64-bit        n        y/y    n        y    y     y
Mac OS X El Capitan 10.11.6 64-bit      n        y/y    n        y    y     y
MacOS High Sierra 10.13.6 64-bit        n        y/y    n        y    y     y
CentOS 7.2 Linux 3.10.0 x86_64 PGI      n        y/y    n        y    y     y
CentOS 7.2 Linux 3.10.0 x86_64 GNU      y        y/y    y        y    y     y
CentOS 7.2 Linux 3.10.0 x86_64 Intel    n        y/y    n        y    y     y
Linux 2.6.32-573.18.1.el6.ppc64         n        y/y    n        y    y     y


Platform                                 Shared  Shared    Shared    Thread-
                                         C libs  F90 libs  C++ libs  safe
Solaris2.11 32-bit                         y       y         y         y
Solaris2.11 64-bit                         y       y         y         y
Windows 7                                  y       y         y         y
Windows 7 x64                              y       y         y         y
Windows 7 Cygwin                           n       n         n         y
Windows 7 x64 Cygwin                       n       n         n         y
Windows 10                                 y       y         y         y
Windows 10 x64                             y       y         y         y
Mac OS X Yosemite 10.10.5 64-bit           y       y         y         y
Mac OS X El Capitan 10.11.6 64-bit         y       y         y         y
MacOS High Sierra 10.13.6 64-bit           y       y         y         y
CentOS 7.2 Linux 3.10.0 x86_64 PGI         y       y         y         n
CentOS 7.2 Linux 3.10.0 x86_64 GNU         y       y         y         y
CentOS 7.2 Linux 3.10.0 x86_64 Intel       y       y         y         n
Linux 2.6.32-573.18.1.el6.ppc64            y       y         y         n

Compiler versions for each platform are listed in the preceding
"Supported Platforms" table.


More Tested Platforms
=====================
The following configurations are not supported but have been tested for this release.

    Linux 2.6.32-573.22.1.el6    GNU C (gcc), Fortran (gfortran), C++ (g++)
    #1 SMP x86_64 GNU/Linux       compilers:
    (mayll/platypus)                 Version 4.4.7 20120313
                                     Version 4.9.3, 5.3.0, 6.2.0
                                  PGI C, Fortran, C++ for 64-bit target on
                                  x86-64;
                                     Version 17.10-0
                                  Intel(R) C (icc), C++ (icpc), Fortran (icc)
                                  compilers:
                                     Version 17.0.4.196 Build 20170411
                                  MPICH 3.1.4 compiled with GCC 4.9.3

    Linux 3.10.0-327.18.2.el7     GNU C (gcc) and C++ (g++) compilers
    #1 SMP x86_64 GNU/Linux          Version 4.8.5 20150623 (Red Hat 4.8.5-4)
    (jelly)                       with NAG Fortran Compiler Release 6.1(Tozai)
                                  GCC Version 7.1.0
                                  MPICH 3.2-GCC-4.9.3
                                  MPICH 3.2.1-GCC-7.2.0-2.29
                                  OpenMPI 2.1.5-GCC-7.2.0-2.29
                                  Intel(R) C (icc) and C++ (icpc) compilers
                                     Version 17.0.0.098 Build 20160721
                                  with NAG Fortran Compiler Release 6.1(Tozai)

    Linux 3.10.0-327.10.1.el7     MPICH 3.2 compiled with GCC 5.3.0
    #1 SMP x86_64 GNU/Linux
    (moohan)

    Fedora 29  4.20.10-200.fc29.x86_64 #1 SMP x86_64 x86_64 x86_64 GNU/Linux
                                  gcc, g++ (GCC) 8.2.1 20181215
                                      (Red Hat 8.2.1-6)
                                  GNU Fortran (GCC) 8.2.1 20181215
                                      (Red Hat 8.2.1-6)
                                  (cmake and autotools)

    Windows 7 x64                 Visual Studio 2008


Known Problems
==============

    At present, metadata cache images may not be generated by parallel
    applications.  Parallel applications can read files with metadata cache
    images, but since this is a collective operation, a deadlock is possible
    if one or more processes do not participate.

    Three tests fail with OpenMPI 3.0.0/GCC-7.2.0-2.29:
        testphdf5 (ecdsetw, selnone, cchunk1, cchunk3, cchunk4, and actualio)
        t_shapesame (sscontig2)
        t_pflush1/fails on exit
    The first two tests fail attempting collective writes.

    CPP ptable test fails on VS2017 with Intel compiler, JIRA issue: HDFFV-10628.
    This test will pass with VS2015 with Intel compiler.

    Older MPI libraries such as OpenMPI 2.0.1 and MPICH 2.1.5 were tested
    while attempting to resolve the Jira issue: HDFFV-10540.
    The known problems of reading or writing > 2GBs when using MPI-2 was
    partially resolved with the MPICH library. The proposed support recognizes
    IO operations > 2GB and if the datatype is not a derived type, the library
    breaks the IO into chunks which can be input or output with the existing
    MPI 2 limitations, i.e. size reporting and function API size/count
    arguments are restricted to be 32 bit integers.  For derived types larger
    than 2GB, MPICH 2.1.5 fails while attempting to read or write data.
    OpenMPI in contrast, implements MPI-3 APIs even in the older releases
    and thus does not suffer from the 32 bit size limitation described here.
    OpenMPI releases prior to v3.1.3 appear to have other datatype issues however,
    e.g. within a single parallel test (testphdf5) the subtests (cdsetr, eidsetr)
    report data verification errors before eventually aborting.
    The most recent versions of OpenMPI (v3.1.3 or newer) have evidently
    resolved these isses and parallel HDF5 testing does not currently report
    errors though occasional hangs have been observed.

    Known problems in previous releases can be found in the HISTORY*.txt files
    in the HDF5 source. Please report any new problems found to
    help@hdfgroup.org.


CMake vs. Autotools installations
=================================
While both build systems produce similar results, there are differences.
Each system produces the same set of folders on linux (only CMake works
on standard Windows); bin, include, lib and share. Autotools places the
COPYING and RELEASE.txt file in the root folder, CMake places them in
the share folder.

The bin folder contains the tools and the build scripts. Additionally, CMake
creates dynamic versions of the tools with the suffix "-shared". Autotools
installs one set of tools depending on the "--enable-shared" configuration
option.
  build scripts
  -------------
  Autotools: h5c++, h5cc, h5fc
  CMake: h5c++, h5cc, h5hlc++, h5hlcc

The include folder holds the header files and the fortran mod files. CMake
places the fortran mod files into separate shared and static subfolders,
while Autotools places one set of mod files into the include folder. Because
CMake produces a tools library, the header files for tools will appear in
the include folder.

The lib folder contains the library files, and CMake adds the pkgconfig
subfolder with the hdf5*.pc files used by the bin/build scripts created by
the CMake build. CMake separates the C interface code from the fortran code by
creating C-stub libraries for each Fortran library. In addition, only CMake
installs the tools library. The names of the szip libraries are different
between the build systems.

The share folder will have the most differences because CMake builds include
a number of CMake specific files for support of CMake's find_package and support
for the HDF5 Examples CMake project.

%%%%1.10.4%%%%

HDF5 version 1.10.4 released on 2018-10-05
================================================================================


INTRODUCTION

This document describes the differences between this release and the previous
HDF5 release. It contains information on the platforms tested and known
problems in this release. For more details check the HISTORY*.txt files in the
HDF5 source.

Note that documentation in the links below will be updated at the time of each
final release.

Links to HDF5 documentation can be found on The HDF5 web page:

     https://portal.hdfgroup.org/display/HDF5/HDF5

The official HDF5 releases can be obtained from:

     https://www.hdfgroup.org/downloads/hdf5/

Changes from Release to Release and New Features in the HDF5-1.10.x release series
can be found at:

     https://portal.hdfgroup.org/display/HDF5/HDF5+Application+Developer%27s+Guide

If you have any questions or comments, please send them to the HDF Help Desk:

     help@hdfgroup.org


CONTENTS

- Bug Fixes since HDF5-1.10.3
- Supported Platforms
- Tested Configuration Features Summary
- More Tested Platforms
- Known Problems
- CMake vs. Autotools installations


New Features
============

    Configuration:
    -------------
    - Add toolchain and cross-compile support

      Added info on using a toolchain file to INSTALL_CMAKE.txt. A
      toolchain file is also used in cross-compiling, which requires
      CMAKE_CROSSCOMPILING_EMULATOR to be set. To help with cross-compiling
      the fortran configure process, the HDF5UseFortran.cmake file macros
      were improved. Fixed a Fortran configure file issue that incorrectly
      used #cmakedefine instead of #define.

      (ADB - 2018/10/04, HDFFV-10594)

    - Add warning flags for Intel compilers

      Identified Intel compiler specific warnings flags that should be used
      instead of GNU flags.

      (ADB - 2018/10/04, TRILABS-21)

    - Add default rpath to targets

      Default rpaths should be set in shared executables and
      libraries to allow the use of loading dependent libraries
      without requiring LD_LIBRARY_PATH to be set. The default
      path should be relative using @rpath on osx and $ORIGIN
      on linux. Windows is not affected.

      (ADB - 2018/09/26, HDFFV-10594)

    Library:
    --------
    - Allow pre-generated H5Tinit.c and H5make_libsettings.c to be used.

      Rather than always running H5detect and generating H5Tinit.c and
      H5make_libsettings.c, supply a location for those files.

      (ADB - 2018/09/18, HDFFV-10332)


Bug Fixes since HDF5-1.10.3 release
==================================

    Library
    -------
    - Allow H5detect and H5make_libsettings to take a file as an argument.

      Rather than only writing to stdout, add a command argument to name
      the file that H5detect and H5make_libsettings will use for output.
      Without an argument, stdout is still used, so backwards compatibility
      is maintained.

      (ADB - 2018/09/05, HDFFV-9059)

    - A bug was discovered in the parallel library where an application
      would hang if a collective read/write of a chunked dataset occurred
      when collective metadata reads were enabled and some of the ranks
      had no selection in the dataset's dataspace. The ranks which had no
      selection in the dataset's dataspace called H5D__chunk_addrmap() to
      retrieve the lowest chunk address in the dataset. This is because we
      require reads/writes to be performed in strictly non-decreasing order
      of chunk address in the file.

      When the chunk index used was a version 1 or 2 B-tree, these
      non-participating ranks would issue a collective MPI_Bcast() call
      that the participating ranks would not issue, causing the hang. Since
      the non-participating ranks are not actually reading/writing anything,
      the H5D__chunk_addrmap() call can be safely removed and the address used
      for the read/write can be set to an arbitrary number (0 was chosen).

      (JTH - 2018/08/25, HDFFV-10501)

    Java Library:
    ----------------
    - JNI native library dependencies

      The build for the hdf5_java native library used the wrong
      hdf5 target library for CMake builds. Correcting the hdf5_java
      library to build with the shared hdf5 library required testing
      paths to change also.

      (ADB - 2018/08/31, HDFFV-10568)

    - Java iterator callbacks

      Change global callback object to a small stack structure in order
      to fix a runtime crash. This crash was discovered when iterating
      through a file with nested group members. The global variable
      visit_callback is overwritten when recursion starts. When recursion
      completes, visit_callback will be pointing to the wrong callback method.

      (ADB - 2018/08/15, HDFFV-10536)

    - Java HDFLibraryException class

      Change parent class from Exception to RuntimeException.

      (ADB - 2018/07/30, HDFFV-10534)

    - JNI Read and Write

      Refactored variable-length functions, H5DreadVL and H5AreadVL,
      to correct dataset and attribute reads. New write functions,
      H5DwriteVL and H5AwriteVL, are under construction.

      (ADB - 2018/06/02, HDFFV-10519)


Supported Platforms
===================

    Linux 2.6.32-696.16.1.el6.ppc64 gcc (GCC) 4.4.7 20120313 (Red Hat 4.4.7-18)
    #1 SMP ppc64 GNU/Linux        g++ (GCC) 4.4.7 20120313 (Red Hat 4.4.7-18)
    (ostrich)                     GNU Fortran (GCC) 4.4.7 20120313 (Red Hat 4.4.7-18)
                                  IBM XL C/C++ V13.1
                                  IBM XL Fortran V15.1

    Linux 3.10.0-327.10.1.el7   GNU C (gcc), Fortran (gfortran), C++ (g++)
    #1 SMP x86_64 GNU/Linux       compilers:
    (kituo/moohan)                Version 4.8.5 20150623 (Red Hat 4.8.5-4)
                                    Version 4.9.3, Version 5.2.0
                                  Intel(R) C (icc), C++ (icpc), Fortran (icc)
                                  compilers:
                                     Version 17.0.0.098 Build 20160721
                                  MPICH 3.1.4 compiled with GCC 4.9.3

    SunOS 5.11 32- and 64-bit     Sun C 5.12 SunOS_sparc
    (emu)                         Sun Fortran 95 8.6 SunOS_sparc
                                  Sun C++ 5.12 SunOS_sparc

    Windows 7                     Visual Studio 2015 w/ Intel Fortran 16 (cmake)

    Windows 7 x64                 Visual Studio 2012 w/ Intel Fortran 15 (cmake)
                                  Visual Studio 2013 w/ Intel Fortran 15 (cmake)
                                  Visual Studio 2015 w/ Intel Fortran 16 (cmake)
                                  Visual Studio 2015 w/ Intel C, Fortran 2017 (cmake)
                                  Visual Studio 2015 w/ MSMPI 8 (cmake)

    Windows 10                    Visual Studio 2015 w/ Intel Fortran 18 (cmake)

    Windows 10 x64                Visual Studio 2015 w/ Intel Fortran 18 (cmake)
                                  Visual Studio 2017 w/ Intel Fortran 18 (cmake)

    Mac OS X Yosemite 10.10.5     Apple clang/clang++ version 6.1 from Xcode 7.0
    64-bit                        gfortran GNU Fortran (GCC) 4.9.2
    (osx1010dev/osx1010test)      Intel icc/icpc/ifort version 15.0.3

    Mac OS X El Capitan 10.11.6   Apple clang/clang++ version 7.3.0 from Xcode 7.3
    64-bit                        gfortran GNU Fortran (GCC) 5.2.0
    (osx1011dev/osx1011test)      Intel icc/icpc/ifort version 16.0.2

    Mac OS Sierra 10.12.6         Apple LLVM version 8.1.0 (clang/clang++-802.0.42)
    64-bit                        gfortran GNU Fortran (GCC) 7.1.0
    (kite)                        Intel icc/icpc/ifort version 17.0.2


Tested Configuration Features Summary
=====================================

    In the tables below
          y   = tested
          n   = not tested in this release
          C   = Cluster
          W   = Workstation
          x   = not working in this release
          dna = does not apply
          ( ) = footnote appears below second table
          <blank> = testing incomplete on this feature or platform

Platform                              C         F90/   F90      C++  zlib  SZIP
                                      parallel  F2003  parallel
Solaris2.11 32-bit                      n        y/y    n        y    y     y
Solaris2.11 64-bit                      n        y/n    n        y    y     y
Windows 7                               y        y/y    n        y    y     y
Windows 7 x64                           y        y/y    y        y    y     y
Windows 7 Cygwin                        n        y/n    n        y    y     y
Windows 7 x64 Cygwin                    n        y/n    n        y    y     y
Windows 10                              y        y/y    n        y    y     y
Windows 10 x64                          y        y/y    n        y    y     y
Mac OS X Mavericks 10.9.5 64-bit        n        y/y    n        y    y     y
Mac OS X Yosemite 10.10.5 64-bit        n        y/y    n        y    y     y
Mac OS X El Capitan 10.11.6 64-bit      n        y/y    n        y    y     y
Mac OS Sierra 10.12.6 64-bit            n        y/y    n        y    y     y
CentOS 7.2 Linux 3.10.0 x86_64 PGI      n        y/y    n        y    y     y
CentOS 7.2 Linux 3.10.0 x86_64 GNU      y        y/y    y        y    y     y
CentOS 7.2 Linux 3.10.0 x86_64 Intel    n        y/y    n        y    y     y
Linux 2.6.32-573.18.1.el6.ppc64         n        y/y    n        y    y     y


Platform                                 Shared  Shared    Shared    Thread-
                                         C libs  F90 libs  C++ libs  safe
Solaris2.11 32-bit                         y       y         y         y
Solaris2.11 64-bit                         y       y         y         y
Windows 7                                  y       y         y         y
Windows 7 x64                              y       y         y         y
Windows 7 Cygwin                           n       n         n         y
Windows 7 x64 Cygwin                       n       n         n         y
Windows 10                                 y       y         y         y
Windows 10 x64                             y       y         y         y
Mac OS X Mavericks 10.9.5 64-bit           y       n         y         y
Mac OS X Yosemite 10.10.5 64-bit           y       n         y         y
Mac OS X El Capitan 10.11.6 64-bit         y       n         y         y
Mac OS Sierra 10.12.6 64-bit               y       n         y         y
CentOS 7.2 Linux 3.10.0 x86_64 PGI         y       y         y         n
CentOS 7.2 Linux 3.10.0 x86_64 GNU         y       y         y         y
CentOS 7.2 Linux 3.10.0 x86_64 Intel       y       y         y         n
Linux 2.6.32-573.18.1.el6.ppc64            y       y         y         n

Compiler versions for each platform are listed in the preceding
"Supported Platforms" table.


More Tested Platforms
=====================
The following platforms are not supported but have been tested for this release.

    Linux 2.6.32-573.22.1.el6    GNU C (gcc), Fortran (gfortran), C++ (g++)
    #1 SMP x86_64 GNU/Linux       compilers:
    (mayll/platypus)                 Version 4.4.7 20120313
                                     Version 4.9.3, 5.3.0, 6.2.0
                                  PGI C, Fortran, C++ for 64-bit target on
                                  x86-64;
                                     Version 17.10-0
                                  Intel(R) C (icc), C++ (icpc), Fortran (icc)
                                  compilers:
                                     Version 17.0.4.196 Build 20170411
                                  MPICH 3.1.4 compiled with GCC 4.9.3

    Linux 3.10.0-327.18.2.el7     GNU C (gcc) and C++ (g++) compilers
    #1 SMP x86_64 GNU/Linux          Version 4.8.5 20150623 (Red Hat 4.8.5-4)
    (jelly)                       with NAG Fortran Compiler Release 6.1(Tozai)
                                  GCC Version 7.1.0
                                  OpenMPI 3.0.0-GCC-7.2.0-2.29,
                                     3.1.0-GCC-7.2.0-2.29
                                  Intel(R) C (icc) and C++ (icpc) compilers
                                     Version 17.0.0.098 Build 20160721
                                  with NAG Fortran Compiler Release 6.1(Tozai)

    Linux 3.10.0-327.10.1.el7     MPICH 3.2 compiled with GCC 5.3.0
    #1 SMP x86_64 GNU/Linux
    (moohan)

    Linux 2.6.32-573.18.1.el6.ppc64  MPICH mpich 3.1.4 compiled with
    #1 SMP ppc64 GNU/Linux           IBM XL C/C++ for Linux, V13.1
    (ostrich)                        and IBM XL Fortran for Linux, V15.1

    Debian 8.4 3.16.0-4-amd64 #1 SMP Debian 3.16.36-1 x86_64 GNU/Linux
                                  gcc, g++ (Debian 4.9.2-10) 4.9.2
                                  GNU Fortran (Debian 4.9.2-10) 4.9.2
                                  (cmake and autotools)

    Fedora 24  4.7.2-201.fc24.x86_64 #1 SMP x86_64 x86_64 x86_64 GNU/Linux
                                  gcc, g++ (GCC) 6.1.1 20160621
                                      (Red Hat 6.1.1-3)
                                  GNU Fortran (GCC) 6.1.1 20160621
                                      (Red Hat 6.1.1-3)
                                  (cmake and autotools)

    Ubuntu 16.04.1 4.4.0-38-generic #57-Ubuntu SMP x86_64 GNU/Linux
                                  gcc, g++ (Ubuntu 5.4.0-6ubuntu1~16.04.2)
                                      5.4.0 20160609
                                  GNU Fortran (Ubuntu 5.4.0-6ubuntu1~16.04.2)
                                      5.4.0 20160609
                                  (cmake and autotools)


Known Problems
==============

    At present, metadata cache images may not be generated by parallel
    applications.  Parallel applications can read files with metadata cache
    images, but since this is a collective operation, a deadlock is possible
    if one or more processes do not participate.

    Three tests fail with OpenMPI 3.0.0/GCC-7.2.0-2.29:
        testphdf5 (ecdsetw, selnone, cchunk1, cchunk3, cchunk4, and actualio)
        t_shapesame (sscontig2)
        t_pflush1/fails on exit
    The first two tests fail attempting collective writes.

    Known problems in previous releases can be found in the HISTORY*.txt files
    in the HDF5 source. Please report any new problems found to
    help@hdfgroup.org.


CMake vs. Autotools installations
=================================
While both build systems produce similar results, there are differences.
Each system produces the same set of folders on linux (only CMake works
on standard Windows); bin, include, lib and share. Autotools places the
COPYING and RELEASE.txt file in the root folder, CMake places them in
the share folder.

The bin folder contains the tools and the build scripts. Additionally, CMake
creates dynamic versions of the tools with the suffix "-shared". Autotools
installs one set of tools depending on the "--enable-shared" configuration
option.
  build scripts
  -------------
  Autotools: h5c++, h5cc, h5fc
  CMake: h5c++, h5cc, h5hlc++, h5hlcc

The include folder holds the header files and the fortran mod files. CMake
places the fortran mod files into separate shared and static subfolders,
while Autotools places one set of mod files into the include folder. Because
CMake produces a tools library, the header files for tools will appear in
the include folder.

The lib folder contains the library files, and CMake adds the pkgconfig
subfolder with the hdf5*.pc files used by the bin/build scripts created by
the CMake build. CMake separates the C interface code from the fortran code by
creating C-stub libraries for each Fortran library. In addition, only CMake
installs the tools library. The names of the szip libraries are different
between the build systems.

The share folder will have the most differences because CMake builds include
a number of CMake specific files for support of CMake's find_package and support
for the HDF5 Examples CMake project.

%%%%1.10.3%%%%

HDF5 version 1.10.3 released on 2018-08-21
================================================================================


INTRODUCTION

This document describes the differences between this release and the previous
HDF5 release. It contains information on the platforms tested and known
problems in this release. For more details check the HISTORY*.txt files in the
HDF5 source.

Note that documentation in the links below will be updated at the time of each
final release.

Links to HDF5 documentation can be found on The HDF5 web page:

     https://portal.hdfgroup.org/display/HDF5/HDF5

The official HDF5 releases can be obtained from:

     https://www.hdfgroup.org/downloads/hdf5/

Changes from Release to Release and New Features in the HDF5-1.10.x release series
can be found at:

     https://portal.hdfgroup.org/display/HDF5/HDF5+Application+Developer%27s+Guide

If you have any questions or comments, please send them to the HDF Help Desk:

     help@hdfgroup.org


CONTENTS

- New Features
- Bug Fixes since HDF5-1.10.2
- Supported Platforms
- Tested Configuration Features Summary
- More Tested Platforms
- Known Problems
- CMake vs. Autotools installations


New Features
============

    Library
    -------
    - Moved the H5DOread/write_chunk() API calls to H5Dread/write_chunk()

      The functionality of the direct chunk I/O calls in the high-level
      library has been moved to the H5D package in the main library. This
      will allow using those functions without building the high-level
      library. The parameters and functionality of the H5D calls are
      identical to the H5DO calls.

      The original H5DO high-level API calls have been retained, though
      they are now just wrappers for the H5D calls. They are marked as
      deprecated and are only available when the library is built with
      deprecated functions. New code should use the H5D calls for this
      reason.

      As a part of this work, the following symbols from H5Dpublic.h are no
      longer used:

        H5D_XFER_DIRECT_CHUNK_WRITE_FLAG_NAME
        H5D_XFER_DIRECT_CHUNK_WRITE_FILTERS_NAME
        H5D_XFER_DIRECT_CHUNK_WRITE_OFFSET_NAME
        H5D_XFER_DIRECT_CHUNK_WRITE_DATASIZE_NAME
        H5D_XFER_DIRECT_CHUNK_READ_FLAG_NAME
        H5D_XFER_DIRECT_CHUNK_READ_OFFSET_NAME
        H5D_XFER_DIRECT_CHUNK_READ_FILTERS_NAME

      And properties with these names are no longer stored in the dataset
      transfer property lists. The symbols are still defined in H5Dpublic.h,
      but only when the library is built with deprecated symbols.

      (DER - 2018/05/04)

    Configuration:
    -------------
    - Add missing USE_110_API_DEFAULT option.

      Option USE_110_API_DEFAULT sets the default version of
      versioned APIs. The bin/makevers perl script did not set
      the maxidx variable correctly when the 1.10 branch was
      created. This caused the versioning process to always use
      the latest version of any API.

      (ADB - 2018/08/17, HDFFV-10552)

    - Added configuration checks for the following MPI functions:

      MPI_Mprobe - Used for the Parallel Compression feature
      MPI_Imrecv - Used for the Parallel Compression feature

      MPI_Get_elements_x - Used for the "big Parallel I/O" feature
      MPI_Type_size_x - Used for the "big Parallel I/O" feature

      (JTH - 2018/08/02, HDFFV-10512)

    - Added section to the libhdf5.settings file to indicate
      the status of the Parallel Compression and "big Parallel I/O"
      features.

      (JTH - 2018/08/02, HDFFV-10512)

    - Add option to execute swmr shell scripts from CMake.

      Option TEST_SHELL_SCRIPTS redirects processing into a
      separate ShellTests.cmake file for UNIX types. The tests
      execute the shell scripts if a SH program is found.

      (ADB - 2018/07/16)


    C++ Library:
    ------------
    - New wrappers

      Added the following items:

      + Class DSetAccPropList for the dataset access property list.

      + Wrapper for H5Dget_access_plist to class DataSet
        // Gets the access property list of this dataset.
        DSetAccPropList getAccessPlist() const;

      + Wrappers for H5Pset_chunk_cache and H5Pget_chunk_cache to class DSetAccPropList
        // Sets the raw data chunk cache parameters.
        void setChunkCache(size_t rdcc_nslots, size_t rdcc_nbytes, double rdcc_w0)

        // Retrieves the raw data chunk cache parameters.
        void getChunkCache(size_t &rdcc_nslots, size_t &rdcc_nbytes, double &rdcc_w0)

      + New operator!= to class DataType (HDFFV-10472)
        // Determines whether two datatypes are not the same.
        bool operator!=(const DataType& compared_type)

      + Wrappers for H5Oget_info2, H5Oget_info_by_name2, and H5Oget_info_by_idx2
        (HDFFV-10458)

        // Retrieves information about an HDF5 object.
        void getObjinfo(H5O_info_t& objinfo, unsigned fields = H5O_INFO_BASIC) const;

        // Retrieves information about an HDF5 object, given its name.
        void getObjinfo(const char* name, H5O_info_t& objinfo,
                unsigned fields = H5O_INFO_BASIC,
                const LinkAccPropList& lapl = LinkAccPropList::DEFAULT) const;
        void getObjinfo(const H5std_string& name, H5O_info_t& objinfo,
                unsigned fields = H5O_INFO_BASIC,
                const LinkAccPropList& lapl = LinkAccPropList::DEFAULT) const;

        // Retrieves information about an HDF5 object, given its index.
        void getObjinfo(const char* grp_name, H5_index_t idx_type,
                H5_iter_order_t order, hsize_t idx, H5O_info_t& objinfo,
                unsigned fields = H5O_INFO_BASIC,
                const LinkAccPropList& lapl = LinkAccPropList::DEFAULT) const;
        void getObjinfo(const H5std_string& grp_name, H5_index_t idx_type,
                H5_iter_order_t order, hsize_t idx, H5O_info_t& objinfo,
                unsigned fields = H5O_INFO_BASIC,
                const LinkAccPropList& lapl = LinkAccPropList::DEFAULT) const;

      (BMR - 2018/07/22, HDFFV-10150, HDFFV-10458, HDFFV-1047)


    Java Library:
    ----------------
    - Java HDFLibraryException class

      Change parent class from Exception to RuntimeException.

      (ADB - 2018/07/30, HDFFV-10534)

    - JNI Read and Write

      Refactored variable-length functions, H5DreadVL and H5AreadVL,
      to correct dataset and attribute reads. New write functions,
      H5DwriteVL and H5AwriteVL, are under construction.

      (ADB - 2018/06/02, HDFFV-10519)


Bug Fixes since HDF5-1.10.2 release
==================================

    Library
    -------
    - Performance issue with H5Oget_info

      H5Oget_info family of routines retrieves information for an object such
      as object type, access time, number of attributes, and storage space etc.
      Retrieving all such information regardless is an overkill and causes
      performance issue when doing so for many objects.

      Add an additional parameter "fields" to the the H5Oget_info family of routines
      indicating the type of information to be retrieved.  The same is done to
      the H5Ovisit family of routines which recursively visits an object
      returning object information in a callback function.  Both sets of routines
      are versioned and the corresponding compatibility macros are added.

      The version 2 names of the two sets of routines are:
        (1) H5Oget_info2, H5Oget_info_by_idx2, H5Oget_info_by_name2
        (2) H5Ovisit2, H5Ovisit_by_name2

      (VC - 2018/08/15, HDFFV-10180)

    - Test failure due to metadata size in test/vds.c

      The size of metadata from test_api_get_ex_dcpl() in test/vds.c is not as expected
      because the latest format should be used when encoding the layout for VDS.

      Set the latest format in a temporary fapl and pass the setting to the routines that
      encode the dataset selection for VDS.

      (VC - 2018/08/14 HDFFV-10469)

    - Java HDF5LibraryException class

      The error minor and major values would be lost after the
      constructor executed.

      Created two local class variables to hold the values obtained during
      execution of the constructor. Refactored the class functions to retrieve
      the class values rather then calling the native functions.
      The native functions were renamed and called only during execution
      of the constructor.
      Added error checking to calling class constructors in JNI classes.

      (ADB - 2018/08/06, HDFFV-10544)

    - Added checks of the defined MPI_VERSION to guard against usage of
      MPI-3 functions in the Parallel Compression and "big Parallel I/O"
      features when HDF5 is built with MPI-2. Previously, the configure
      step would pass but the build itself would fail when it could not
      locate the MPI-3 functions used.

      As a result of these new checks, HDF5 can again be built with MPI-2,
      but the Parallel Compression feature will be disabled as it relies
      on the MPI-3 functions used.

      (JTH - 2018/08/02, HDFFV-10512)

    - User's patches: CVEs

      The following patches have been applied:

      CVE-2018-11202 - NULL pointer dereference was discovered in
                       H5S_hyper_make_spans in H5Shyper.c (HDFFV-10476)
        https://security-tracker.debian.org/tracker/CVE-2018-11202
        https://cve.mitre.org/cgi-bin/cvename.cgi?name=3DCVE-2018-11202

      CVE-2018-11203 - A division by zero was discovered in
                       H5D__btree_decode_key in H5Dbtree.c (HDFFV-10477)
        https://security-tracker.debian.org/tracker/CVE-2018-11203
        https://cve.mitre.org/cgi-bin/cvename.cgi?name=3DCVE-2018-11203

      CVE-2018-11204 - A NULL pointer dereference was discovered in
                       H5O__chunk_deserialize in H5Ocache.c (HDFFV-10478)
        https://security-tracker.debian.org/tracker/CVE-2018-11204
        https://cve.mitre.org/cgi-bin/cvename.cgi?name=3DCVE-2018-11204

      CVE-2018-11206 - An out of bound read was discovered in
                       H5O_fill_new_decode and H5O_fill_old_decode in H5Ofill.c
                       (HDFFV-10480)
        https://security-tracker.debian.org/tracker/CVE-2018-11206
        https://cve.mitre.org/cgi-bin/cvename.cgi?name=3DCVE-2018-11206

      CVE-2018-11207 - A division by zero was discovered in
                       H5D__chunk_init in H5Dchunk.c  (HDFFV-10481)
        https://security-tracker.debian.org/tracker/CVE-2018-11207
        https://cve.mitre.org/cgi-bin/cvename.cgi?name=3DCVE-2018-11207

      (BMR - 2018/7/22, PR#s: 1134 and 1139,
       HDFFV-10476, HDFFV-10477, HDFFV-10478, HDFFV-10480, HDFFV-10481)

    - H5Adelete

      H5Adelete failed when deleting the last "large" attribute that
      is stored densely via fractal heap/v2 b-tree.

      After removing the attribute, update the ainfo message.  If the
      number of attributes goes to zero, remove the message.

      (VC - 2018/07/20, HDFFV-9277)

    - A bug was discovered in the parallel library which caused partial
      parallel reads of filtered datasets to return incorrect data. The
      library used the incorrect dataspace for each chunk read, causing
      the selection used in each chunk to be wrong.

      The bug was not caught during testing because all of the current
      tests which do parallel reads of filtered data read all of the data
      using an H5S_ALL selection. Several tests were added which exercise
      partial parallel reads.

      (JTH - 2018/07/16, HDFFV-10467)

    - A bug was discovered in the parallel library which caused parallel
      writes of filtered datasets to trigger an assertion failure in the
      file free space manager.

      This occurred when the filter used caused chunks to repeatedly shrink
      and grow over the course of several dataset writes. The previous chunk
      information, such as the size of the chunk and the offset in the file,
      was being cached and not updated after each write, causing the next write
      to the chunk to retrieve the incorrect cached information and run into
      issues when reallocating space in the file for the chunk.

      (JTH - 2018/07/16, HDFFV-10509)

    - A bug was discovered in the parallel library which caused the
      H5D__mpio_array_gatherv() function to allocate too much memory.

      When the function is called with the 'allgather' parameter set
      to a non-true value, the function will receive data from all MPI
      ranks and gather it to the single rank specified by the 'root'
      parameter. However, the bug in the function caused memory for
      the received data to be allocated on all MPI ranks, not just the
      singular rank specified as the receiver. In some circumstances,
      this would cause an application to fail due to the large amounts
      of memory being allocated.

      (JTH - 2018/07/16, HDFFV-10467)

    - Error checks in h5stat and when decoding messages

      h5stat exited with seg fault/core dumped when
      errors are encountered in the internal library.

      Add error checks and --enable-error-stack option to h5stat.
      Add range checks when decoding messages: old fill value, old
      layout and refcount.

      (VC - 2018/07/11, HDFFV-10333)

    - If an HDF5 file contains a malformed compound datatype with a
      suitably large offset, the type conversion code can run off
      the end of the type conversion buffer, causing a segmentation
      fault.

      This issue was reported to The HDF Group as issue #CVE-2017-17507.

      NOTE: The HDF5 C library cannot produce such a file. This condition
            should only occur in a corrupt (or deliberately altered) file
            or a file created by third-party software.

      THE HDF GROUP WILL NOT FIX THIS BUG AT THIS TIME

      Fixing this problem would involve updating the publicly visible
      H5T_conv_t function pointer typedef and versioning the API calls
      which use it. We normally only modify the public API during
      major releases, so this bug will not be fixed at this time.

      (DER - 2018/02/26, HDFFV-10356)


    Configuration
    -------------
    - Applied patches to address Cywin build issues

      There were three issues for Cygwin builds:
      - Shared libs were not built.
      - The -std=c99 flag caused a SIG_SETMASK undeclared error.
      - Undefined errors when buildbing test shared libraries.

      Patches to address these issues were received and incorporated in this version.

      (LRK - 2018/07/18, HDFFV-10475)

    - The --enable-debug/production configure flags are listed as 'deprecated'
      when they should really be listed as 'removed'.

      In the autotools overhaul several years ago, we removed these flags and
      implemented a new --enable-build-mode= flag. This was done because we
      changed the semantics of the modes and didn't want users to silently
      be exposed to them. The newer system is also more flexible and us to
      add other modes (like 'clean').

      The --enable-debug/production flags are now listed as removed.

      (DER - 2018/05/31, HDFFV-10505)

    - Moved the location of gcc attribute.

      The gcc attribute(no_sanitize), named as the macro HDF_NO_UBSAN,
      was located after the function name. Builds with GCC 7 did not
      indicate any problem, but GCC 8 issued errors. Moved the
      attribute before the function name, as required.

      (ADB - 2018/05/22, HDFFV-10473)

    - Reworked java test suite into individual JUnit tests.

      Testing the whole suite of java unit tests in a single JUnit run
      made it difficult to determine actual failures when tests would fail.
      Running each file set of tests individually, allows individual failures
      to be diagnosed easier. A side benefit is that tests for optional components
      of the library can be disabled if not configured.

      (ADB - 2018/05/16, HDFFV-9739)

    - Converted CMake global commands ADD_DEFINITIONS and INCLUDE_DIRECTORIES
      to use target_* type commands. This change modernizes the CMake usage
      in the HDF5 library.

      In addition, there is the intention to convert to generator expressions,
      where possible. The exception is Fortran FLAGS on Windows Visual Studio.
      The HDF macros TARGET_C_PROPERTIES and TARGET_FORTRAN_PROPERTIES have
      been removed with this change in usage.

      The additional language (C++ and Fortran) checks have also been localized
      to only be checked when that language is enabled.

      (ADB - 2018/05/08)


    Performance
    -------------
    - Revamped internal use of DXPLs, improving performance

      (QAK - 2018/05/20)


    Fortran
    --------
    - Fixed issue with h5fget_obj_count_f and using a file id of H5F_OBJ_ALL_F not
      returning the correct count.

      (MSB - 2018/5/15, HDFFV-10405)


    C++ APIs
    --------
    - Adding default arguments to existing functions

      Added the following items:
      + Two more property list arguments are added to H5Location::createDataSet:
        const DSetAccPropList& dapl = DSetAccPropList::DEFAULT
        const LinkCreatPropList& lcpl = LinkCreatPropList::DEFAULT

      + One more property list argument is added to H5Location::openDataSet:
        const DSetAccPropList& dapl = DSetAccPropList::DEFAULT

      (BMR - 2018/07/21, PR# 1146)

    - Improvement C++ documentation

      Replaced the table in main page of the C++ documentation from mht to htm format
      for portability.

      (BMR - 2018/07/17, PR# 1141)


Supported Platforms
===================

    Linux 2.6.32-696.16.1.el6.ppc64 gcc (GCC) 4.4.7 20120313 (Red Hat 4.4.7-18)
    #1 SMP ppc64 GNU/Linux        g++ (GCC) 4.4.7 20120313 (Red Hat 4.4.7-18)
    (ostrich)                     GNU Fortran (GCC) 4.4.7 20120313 (Red Hat 4.4.7-18)
                                  IBM XL C/C++ V13.1
                                  IBM XL Fortran V15.1

    Linux 3.10.0-327.10.1.el7   GNU C (gcc), Fortran (gfortran), C++ (g++)
    #1 SMP x86_64 GNU/Linux       compilers:
    (kituo/moohan)                Version 4.8.5 20150623 (Red Hat 4.8.5-4)
                                    Version 4.9.3, Version 5.2.0
                                  Intel(R) C (icc), C++ (icpc), Fortran (icc)
                                  compilers:
                                     Version 17.0.0.098 Build 20160721
                                  MPICH 3.1.4 compiled with GCC 4.9.3

    SunOS 5.11 32- and 64-bit     Sun C 5.12 SunOS_sparc
    (emu)                         Sun Fortran 95 8.6 SunOS_sparc
                                  Sun C++ 5.12 SunOS_sparc

    Windows 7                     Visual Studio 2015 w/ Intel Fortran 16 (cmake)

    Windows 7 x64                 Visual Studio 2012 w/ Intel Fortran 15 (cmake)
                                  Visual Studio 2013 w/ Intel Fortran 15 (cmake)
                                  Visual Studio 2015 w/ Intel Fortran 16 (cmake)
                                  Visual Studio 2015 w/ Intel C, Fortran 2017 (cmake)
                                  Visual Studio 2015 w/ MSMPI 8 (cmake)

    Windows 10                    Visual Studio 2015 w/ Intel Fortran 18 (cmake)

    Windows 10 x64                Visual Studio 2015 w/ Intel Fortran 18 (cmake)
                                  Visual Studio 2017 w/ Intel Fortran 18 (cmake)

    Mac OS X Yosemite 10.10.5     Apple clang/clang++ version 6.1 from Xcode 7.0
    64-bit                        gfortran GNU Fortran (GCC) 4.9.2
    (osx1010dev/osx1010test)      Intel icc/icpc/ifort version 15.0.3

    Mac OS X El Capitan 10.11.6   Apple clang/clang++ version 7.3.0 from Xcode 7.3
    64-bit                        gfortran GNU Fortran (GCC) 5.2.0
    (osx1011dev/osx1011test)      Intel icc/icpc/ifort version 16.0.2

    Mac OS Sierra 10.12.6         Apple LLVM version 8.1.0 (clang/clang++-802.0.42)
    64-bit                        gfortran GNU Fortran (GCC) 7.1.0
    (swallow/kite)                Intel icc/icpc/ifort version 17.0.2

Tested Configuration Features Summary
=====================================

    In the tables below
          y   = tested
          n   = not tested in this release
          C   = Cluster
          W   = Workstation
          x   = not working in this release
          dna = does not apply
          ( ) = footnote appears below second table
          <blank> = testing incomplete on this feature or platform

Platform                              C         F90/   F90      C++  zlib  SZIP
                                      parallel  F2003  parallel
Solaris2.11 32-bit                      n        y/y    n        y    y     y
Solaris2.11 64-bit                      n        y/n    n        y    y     y
Windows 7                               y        y/y    n        y    y     y
Windows 7 x64                           y        y/y    y        y    y     y
Windows 7 Cygwin                        n        y/n    n        y    y     y
Windows 7 x64 Cygwin                    n        y/n    n        y    y     y
Windows 10                              y        y/y    n        y    y     y
Windows 10 x64                          y        y/y    n        y    y     y
Mac OS X Mavericks 10.9.5 64-bit        n        y/y    n        y    y     y
Mac OS X Yosemite 10.10.5 64-bit        n        y/y    n        y    y     y
Mac OS X El Capitan 10.11.6 64-bit      n        y/y    n        y    y     y
Mac OS Sierra 10.12.6 64-bit            n        y/y    n        y    y     y
CentOS 7.2 Linux 2.6.32 x86_64 PGI      n        y/y    n        y    y     y
CentOS 7.2 Linux 2.6.32 x86_64 GNU      y        y/y    y        y    y     y
CentOS 7.2 Linux 2.6.32 x86_64 Intel    n        y/y    n        y    y     y
Linux 2.6.32-573.18.1.el6.ppc64         n        y/y    n        y    y     y


Platform                                 Shared  Shared    Shared    Thread-
                                         C libs  F90 libs  C++ libs  safe
Solaris2.11 32-bit                         y       y         y         y
Solaris2.11 64-bit                         y       y         y         y
Windows 7                                  y       y         y         y
Windows 7 x64                              y       y         y         y
Windows 7 Cygwin                           n       n         n         y
Windows 7 x64 Cygwin                       n       n         n         y
Windows 10                                 y       y         y         y
Windows 10 x64                             y       y         y         y
Mac OS X Mavericks 10.9.5 64-bit           y       n         y         y
Mac OS X Yosemite 10.10.5 64-bit           y       n         y         y
Mac OS X El Capitan 10.11.6 64-bit         y       n         y         y
Mac OS Sierra 10.12.6 64-bit               y       n         y         y
CentOS 7.2 Linux 2.6.32 x86_64 PGI         y       y         y         n
CentOS 7.2 Linux 2.6.32 x86_64 GNU         y       y         y         y
CentOS 7.2 Linux 2.6.32 x86_64 Intel       y       y         y         n
Linux 2.6.32-573.18.1.el6.ppc64            y       y         y         n

Compiler versions for each platform are listed in the preceding
"Supported Platforms" table.


More Tested Platforms
=====================
The following platforms are not supported but have been tested for this release.

    Linux 2.6.32-573.22.1.el6    GNU C (gcc), Fortran (gfortran), C++ (g++)
    #1 SMP x86_64 GNU/Linux       compilers:
    (mayll/platypus)                 Version 4.4.7 20120313
                                     Version 4.9.3, 5.3.0, 6.2.0
                                  PGI C, Fortran, C++ for 64-bit target on
                                  x86-64;
                                     Version 17.10-0
                                  Intel(R) C (icc), C++ (icpc), Fortran (icc)
                                  compilers:
                                     Version 17.0.4.196 Build 20170411
                                  MPICH 3.1.4 compiled with GCC 4.9.3

    Linux 3.10.0-327.18.2.el7     GNU C (gcc) and C++ (g++) compilers
    #1 SMP x86_64 GNU/Linux          Version 4.8.5 20150623 (Red Hat 4.8.5-4)
    (jelly)                       with NAG Fortran Compiler Release 6.1(Tozai)
                                  GCC Version 7.1.0
                                  OpenMPI 3.0.0-GCC-7.2.0-2.29,
                                     3.1.0-GCC-7.2.0-2.29
                                  Intel(R) C (icc) and C++ (icpc) compilers
                                     Version 17.0.0.098 Build 20160721
                                  with NAG Fortran Compiler Release 6.1(Tozai)

    Linux 3.10.0-327.10.1.el7     MPICH 3.2 compiled with GCC 5.3.0
    #1 SMP x86_64 GNU/Linux
    (moohan)

    Linux 2.6.32-573.18.1.el6.ppc64  MPICH mpich 3.1.4 compiled with
    #1 SMP ppc64 GNU/Linux           IBM XL C/C++ for Linux, V13.1
    (ostrich)                        and IBM XL Fortran for Linux, V15.1

    Debian 8.4 3.16.0-4-amd64 #1 SMP Debian 3.16.36-1 x86_64 GNU/Linux
                                  gcc, g++ (Debian 4.9.2-10) 4.9.2
                                  GNU Fortran (Debian 4.9.2-10) 4.9.2
                                  (cmake and autotools)

    Fedora 24  4.7.2-201.fc24.x86_64 #1 SMP x86_64 x86_64 x86_64 GNU/Linux
                                  gcc, g++ (GCC) 6.1.1 20160621
                                      (Red Hat 6.1.1-3)
                                  GNU Fortran (GCC) 6.1.1 20160621
                                      (Red Hat 6.1.1-3)
                                  (cmake and autotools)

    Ubuntu 16.04.1 4.4.0-38-generic #57-Ubuntu SMP x86_64 GNU/Linux
                                  gcc, g++ (Ubuntu 5.4.0-6ubuntu1~16.04.2)
                                      5.4.0 20160609
                                  GNU Fortran (Ubuntu 5.4.0-6ubuntu1~16.04.2)
                                      5.4.0 20160609
                                  (cmake and autotools)


Known Problems
==============

    At present, metadata cache images may not be generated by parallel
    applications.  Parallel applications can read files with metadata cache
    images, but since this is a collective operation, a deadlock is possible
    if one or more processes do not participate.

    Three tests fail with OpenMPI 3.0.0/GCC-7.2.0-2.29:
        testphdf5 (ecdsetw, selnone, cchunk1, cchunk3, cchunk4, and actualio)
        t_shapesame (sscontig2)
        t_pflush1/fails on exit
    The first two tests fail attempting collective writes.

    Known problems in previous releases can be found in the HISTORY*.txt files
    in the HDF5 source. Please report any new problems found to
    help@hdfgroup.org.


CMake vs. Autotools installations
=================================
While both build systems produce similar results, there are differences.
Each system produces the same set of folders on linux (only CMake works
on standard Windows); bin, include, lib and share. Autotools places the
COPYING and RELEASE.txt file in the root folder, CMake places them in
the share folder.

The bin folder contains the tools and the build scripts. Additionally, CMake
creates dynamic versions of the tools with the suffix "-shared". Autotools
installs one set of tools depending on the "--enable-shared" configuration
option.
  build scripts
  -------------
  Autotools: h5c++, h5cc, h5fc
  CMake: h5c++, h5cc, h5hlc++, h5hlcc

The include folder holds the header files and the fortran mod files. CMake
places the fortran mod files into separate shared and static subfolders,
while Autotools places one set of mod files into the include folder. Because
CMake produces a tools library, the header files for tools will appear in
the include folder.

The lib folder contains the library files, and CMake adds the pkgconfig
subfolder with the hdf5*.pc files used by the bin/build scripts created by
the CMake build. CMake separates the C interface code from the fortran code by
creating C-stub libraries for each Fortran library. In addition, only CMake
installs the tools library. The names of the szip libraries are different
between the build systems.

The share folder will have the most differences because CMake builds include
a number of CMake specific files for support of CMake's find_package and support
for the HDF5 Examples CMake project.


%%%%1.10.2%%%%

HDF5 version 1.10.2 released on 2018-03-29
================================================================================


INTRODUCTION

This document describes the differences between this release and the previous
HDF5 release. It contains information on the platforms tested and known
problems in this release. For more details check the HISTORY*.txt files in the
HDF5 source.

Note that documentation in the links below will be updated at the time of each
final release.

Links to HDF5 documentation can be found on The HDF5 web page:

     https://portal.hdfgroup.org/display/HDF5/HDF5

The official HDF5 releases can be obtained from:

     https://www.hdfgroup.org/downloads/hdf5/

Changes from Release to Release and New Features in the HDF5-1.10.x release series
can be found at:

     https://portal.hdfgroup.org/display/HDF5/HDF5+Application+Developer%27s+Guide

If you have any questions or comments, please send them to the HDF Help Desk:

     help@hdfgroup.org


CONTENTS

- New Features
- Support for new platforms and languages
- Bug Fixes since HDF5-1.10.1
- Supported Platforms
- Tested Configuration Features Summary
- More Tested Platforms
- Known Problems


New Features
============

    Configuration and Build Systems:
    --------------------------------
    - CMake builds
    --------------

      - Changed minimum CMake required version to 3.10.

      This change removed the need to support a copy of the FindMPI.cmake module,
      which has been removed, along with its subfolder in the config/cmake_ext_mod
      location.

      (ADB - 2018/03/09)

      - Added pkg-config file generation

      Added pkg-config file generation for the C, C++, HL, and HL C++ libraries.
      In addition, builds on Linux will create h5cc, h5c++, h5hlcc, and h5hlc++ scripts in the bin
      directory that use the pkg-config files. The scripts can be used to build HDF5 C and C++
      applications (i.e, similar to the compiler scripts produced by the Autotools builds).

      (ADB - 2018/03/08, HDFFV-4359)

       - Refactored use of CMAKE_BUILD_TYPE for new variable, which understands
      the type of generator in use.

      Added new configuration macros to use new HDF_BUILD_TYPE variable. This
      variable is set correctly for the type of generator being used for the build.

      (ADB - 2018/01/08, HDFFV-10385, HDFFV-10296)

    - Autotools builds
    ------------------

       - Removed version-specific gcc/gfortran flags for version 4.0 (inclusive)
      and earlier.

      The config/gnu-flags file, which is sourced as a part of the configure
      process, adds version-specific flags for use when building HDF5. Most of
      these flags control warnings and do not affect the final product.

      Flags for older versions of the compiler were consolidated into the
      common flags section. Moving these flags simplifies maintenance of
      the file.

      The upshot of this is that building with ancient versions of gcc
      (<= 4.0) will possibly no longer work without hand-hacking the file
      to remove the flags not understood by that version of the compiler.
      Nothing should change when building with gcc >= 4.1.

      (DER - 2017/05/31, HDFFV-9937)

       - -fno-omit-frame-pointer was added when building with debugging symbols
      enabled.

      Debugging symbols can be enabled independently of the overall build
      mode in both the autotools and CMake. This allows (limited) debugging
      of optimized code. Since many debuggers rely on the frame pointer,
      we've disabled this optimization when debugging symbols are requested
      (e.g.: via building with --enable-symbols).

      (DER - 2017/05/31, HDFFV-10226)


    Library:
    --------
    - Added an enumerated value to H5F_libver_t for H5Pset_libver_bounds().

      Currently, the library defines two values for H5F_libver_t and supports
      only two pairs of (low, high) combinations as derived from these values.
      Thus the bounds setting via H5Pset_libver_bounds() is rather restricted.

      Added an enumerated value (H5F_LIBVER_V18) to H5F_libver_t and
      H5Pset_libver_bounds() now supports five pairs of (low, high) combinations
      as derived from these values.  This addition provides the user more
      flexibility in setting bounds for object creation.

      (VC - 2018/03/14)

    - Added prefix option to VDS files.

      Currently, VDS source files must be in the active directory to be
      found by the virtual file. Adding the option of a prefix to be set
      on the virtual file, using a data access property list (DAPL),
      allows the source files to locate at an absolute or relative path
      to the virtual file.
      Private utility functions in H5D and H5L packages merged into single
      function in H5F package.

      New public APIs:
            herr_t H5Pset_virtual_prefix(hid_t dapl_id, const char* prefix);
            ssize_t H5Pget_virtual_prefix(hid_t dapl_id, char* prefix /*out*/, size_t size);
      The prefix can also be set with an environment variable, HDF5_VDS_PREFIX.

      (ADB - 2017/12/12, HDFFV-9724, HDFFV-10361)

    - H5FDdriver_query() API call added to the C library.

      This new library call allows the user to query a virtual file driver
      (VFD) for the feature flags it supports (listed in H5FDpublic.h).
      This can be useful to determine if a VFD supports SWMR, for example.

      Note that some VFDs have feature flags that may only be present
      after a file has been created or opened (e.g.: the core VFD will
      have the H5FD_FEAT_POSIX_COMPAT_HANDLE flag set if the backing
      store is switched on). Since the new API call queries a generic VFD
      unassociated with a file, these flags will never be returned.

      (DER - 2017/05/31, HDFFV-10215)

    - H5FD_FEAT_DEFAULT_VFD_COMPATIBLE VFD feature flag added to the C library.

      This new feature flag indicates that the VFD is compatible with the
      default VFD. VFDs that set this flag create single files that follow
      the canonical HDF5 file format.

      (DER - 2017/05/31, HDFFV-10214)

    - The H5I_REFERENCE value in the H5I_type_t enum (defined in H5Ipublic.h)
      has been marked as deprecated.

      This ID type value is not used in the C library. i.e.: There are no
      hid_t values that are of ID type H5I_REFERENCE.

      This enum value will be removed in a future major version of the library.
      The code will remain unchanged in the HDF5 1.10.x  releases and branches.

      (DER - 2017/04/05, HDFFV-10252)


    Parallel Library:
    -----------------
    - Enabled compression for parallel applications.

      With this release parallel applications can create and write compressed
      datasets (or the datasets with the filters such as Fletcher32 applied).

      (EIP - 2018/03/29)

    - Addressed slow file close on some Lustre file systems.

      Slow file close has been reported on some Lustre file systems.
      While the ultimate cause is not understood fully, the proximate
      cause appears to be long delays in MPI_File_set_size() calls at
      file close and flush.

      To minimize this problem pending a definitive diagnosis and fix,
      PHDF5 has been modified to avoid MPI_File_set_size() calls when
      possible.  This is done by comparing the library's EOA (End of
      Allocation) with the file systems EOF, and skipping the
      MPI_File_set_size() call if the two match.

      (JRM - 2018/03/29)

    - Optimized parallel open/location of the HDF5 super-block.

      Previous releases of PHDF5 required all parallel ranks to
      search for the HDF5 superblock signature when opening the
      file. As this is accomplished more or less as a synchronous
      operation, a large number of processes can experience a
      slowdown in the file open due to filesystem contention.

      As a first step in improving the startup/file-open performance,
      we allow MPI rank 0 of the associated MPI communicator to locate
      the base offset of the super-block and then broadcast that result
      to the remaining ranks in the parallel group.  Note that this
      approach is utilized ONLY during file opens which employ the MPIO
      file driver in HDF5 by previously having called H5Pset_fapl_mpio().

      HDF5 parallel file operations which do not employ multiple ranks
      e.g. specifying MPI_COMM_SELF (whose MPI_Comm_size == 1)
      as opposed to MPI_COMM_WORLD, will not be affected by this
      optimization.  Conversely, parallel file operations on subgroups
      of MPI_COMM_WORLD are allowed to be run in parallel with each
      subgroup operating as an independent collection of processes.

      (RAW - 2017/10/10, HDFFV-10294)

    - Added large (>2GB)  MPI-IO transfers.

      Previous releases of PHDF5 would fail when attempting to
      read or write greater than 2GB of data in a single IO operation.
      This issue stems principally from an MPI API whose definitions
      utilize 32 bit integers to describe the number of data elements
      and datatype that MPI should use to effect a data transfer.
      Historically, HDF5 has invoked MPI-IO with the number of
      elements in a contiguous buffer represented as the length
      of that buffer in bytes.

      Resolving the issue and thus enabling larger MPI-IO transfers
      is accomplished first, by detecting when a user IO request would
      exceed the 2GB limit as described above.  Once a transfer request
      is identified as requiring special handling, PHDF5 now creates a
      derived datatype consisting of a vector of fixed sized blocks
      which is in turn wrapped within a single MPI_Type_struct to
      contain the vector and any remaining data.   The newly created
      datatype is then used in place of MPI_BYTE and can be used to
      fulfill the original user request without encountering API
      errors.

      (RAW - 2017/09/10, HDFFV-8839)


    C++ Library:
    ------------
    - The following C++ API wrappers have been added to the C++ Library:
      + H5Lcreate_soft:
        // Creates a soft link from link_name to target_name.
        void link(const char *target_name, const char *link_name,...)
        void link(const H5std_string& target_name,...)

      + H5Lcreate_hard:
        // Creates a hard link from new_name to curr_name.
        void link(const char *curr_name, const Group& new_loc,...)
        void link(const H5std_string& curr_name, const Group& new_loc,...)

        // Creates a hard link from new_name to curr_name in same location.
        void link(const char *curr_name, const hid_t same_loc,...)
        void link(const H5std_string& curr_name, const hid_t same_loc,...)

        Note: previous version of H5Location::link will be deprecated.

      + H5Lcopy:
        // Copy an object from a group of file to another.
        void copyLink(const char *src_name, const Group& dst,...)
        void copyLink(const H5std_string& src_name, const Group& dst,...)

        // Copy an object from a group of file to the same location.
        void copyLink(const char *src_name, const char *dst_name,...)
        void copyLink(const H5std_string& src_name,...)

      + H5Lmove:
        // Rename an object in a group or file to a new location.
        void moveLink(const char* src_name, const Group& dst,...)
        void moveLink(const H5std_string& src_name, const Group& dst,...)

        // Rename an object in a group or file to the same location.
        void moveLink(const char* src_name, const char* dst_name,...)
        void moveLink(const H5std_string& src_name,...)

        Note: previous version H5Location::move will be deprecated.

      + H5Ldelete:
        // Removes the specified link from this location.
        void unlink(const char *link_name,
            const LinkAccPropList& lapl = LinkAccPropList::DEFAULT)
        void unlink(const H5std_string& link_name,
            const LinkAccPropList& lapl = LinkAccPropList::DEFAULT)

        Note: additional parameter is added to previous H5Location::unlink.

      + H5Tencode and H5Tdecode:
        // Creates a binary object description of this datatype.
        void DataType::encode() - C API H5Tencode()

        // Returns the decoded type from the binary object description.
        DataType::decode() - C API H5Tdecode()
        ArrayType::decode() - C API H5Tdecode()
        CompType::decode() - C API H5Tdecode()
        DataType::decode() - C API H5Tdecode()
        EnumType::decode() - C API H5Tdecode()
        FloatType::decode() - C API H5Tdecode()
        IntType::decode() - C API H5Tdecode()
        StrType::decode() - C API H5Tdecode()
        VarLenType::decode() - C API H5Tdecode()

      + H5Lget_info:
        // Returns the information of the named link.
        H5L_info_t getLinkInfo(const H5std_string& link_name,...)

      (BMR - 2018/03/11, HDFFV-10149)

    - Added class LinkCreatPropList for link create property list.

      (BMR - 2018/03/11, HDFFV-10149)

    - Added overloaded functions H5Location::createGroup to take a link
      creation property list.
        Group createGroup(const char* name, const LinkCreatPropList& lcpl)
        Group createGroup(const H5std_string& name, const LinkCreatPropList& lcpl)

      (BMR - 2018/03/11, HDFFV-10149)

    - A document is added to the HDF5 C++ API Reference Manual to show the
      mapping from a C API to C++ wrappers.  It can be found from the main
      page of the C++ API Reference Manual.

      (BMR - 2017/10/17, HDFFV-10151)


    Java Library:
    ----------------
    - Wrapper added for enabling the error stack.

      H5error_off would disable the error stack reporting. In order
      to re-enable the reporting, the error stack info needs to be
      saved so that H5error_on can revert state.

      (ADB - 2018/03/13, HDFFV-10412)

    - Wrappers were added for the following C APIs:
      H5Pset_evict_on_close
      H5Pget_evict_on_close
      H5Pset_chunk_opts
      H5Pget_chunk_opts
      H5Pset_efile_prefix
      H5Pget_efile_prefix
      H5Pset_virtual_prefix
      H5Pget_virtual_prefix

      (ADB - 2017/12/20)

    - The H5I_REFERENCE value in the H5I_type_t enum (defined in H5Ipublic.h)
      has been marked as deprecated.

      JNI code which refers to this value will be removed in a future
      major version of the library. The code will remain unchanged in the
      1.10.x releases and branches.

      See the C library section, above, for further information.

      (HDFFV-10252, DER, 2017/04/05)


    Tools:
    ------
    - h5diff has a new option to display error stack.

      Updated h5diff with the --enable-error-stack argument, which
      enables the display of the hdf5 error stack. This completes the
      improvement to the main tools: h5copy, h5diff, h5dump, h5ls and
      h5repack.

      (ADB - 2017/08/30, HDFFV-9774)


Support for new platforms, languages and compilers.
=======================================
    - None

Bug Fixes since HDF5-1.10.1 release
==================================

    Library
    -------
    - The data read after a direct chunk write to a chunked dataset with
      one chunk was incorrect.

      The problem was due to the passing of a null dataset pointer to
      the insert callback for the chunk index in the routine
      H5D__chunk_direct_write() in H5Dchunk.c
      The dataset was a single-chunked dataset which will use the
      single chunk index when latest format was enabled on file creation.
      The single chunk index was the only index that used this pointer
      in the insert callback.

      Passed the dataset pointer to the insert callback for the chunk
      index in H5D__chunk_direct_write().

      (VC - 2018/03/20, HDFFV-10425)

    - Added public routine H5DOread_chunk to the high-level C library.

      The patch for H5DOwrite_chunk() to write an entire chunk to the file
      directly was contributed by GE Healthcare and integrated by The HDF Group
      developers.

      (VC - 2017/05/19, HDFFV-9934)

    - Freeing of object header after failed checksum verification.

      It was discovered that the object header (in H5Ocache.c) was not released properly
      when the checksum verification failed and a re-load of the object
      header was needed.

      Freed the object header that failed the chksum verification only
      after the new object header is reloaded, deserialized and set up.

      (VC - 2018/03/14, HDFFV-10209)

    - Updated H5Pset_evict_on_close in H5Pfapl.c

      Changed the minor error number from H5E_CANTSET to H5E_UNSUPPORTED for
      parallel library.

      (ADB - 2018/03/06, HDFFV-10414)

    - Fixed the problems with the utility function that could not handle lowercase
      Windows drive letters.

      Added call to upper function for drive letter.

      (ADB - 2017/12/18, HDFFV-10307)

    - Fixed H5Sencode() bug when the number of elements selected was > 2^32.

      H5Sencode() incorrectly encodes dataspace selection with number of
      elements exceeding 2^32.  When decoding such selection via H5Sdecode(),
      the number of elements in the decoded dataspace is not the same as
      what is encoded.  This problem exists for H5S_SEL_HYPER and
      H5S_SEL_POINTS encoding.

      The cause of the problem is due to the fact that the library uses 32 bits to
      encode counts and block offsets for the selection.
      The solution is to use the original 32 bit encodings if possible,
      but use a different way to encode selection if more that 32 bits is needed.
      See details in the RFC: H5Sencode/H5Sdecode Format Change i
      https://bitbucket.hdfgroup.org/projects/HDFFV/repos/hdf5doc/browse/RFCs/HDF5_Library/H5SencodeFormatChange.

      (VC - 2017/11/28, HDFFV-9947)

    - Fixed filter plugin handling in H5PL.c and H5Z.c to not require i availability of
      dependent libraries (e.g., szip or zlib).

      It was discovered that the dynamic loading process used by
      filter plugins had issues with library dependencies.

      CMake build process changed to use LINK INTERFACE keywords, which
      allowed HDF5 C library to make dependent libraries private. The
      filter plugin libraries no longer require dependent libraries
      (such as szip or zlib) to be available.

      (ADB - 2017/11/16, HDFFV-10328)

    - Fixed rare object header corruption bug.

      In certain cases, such as when converting large attributes to dense
      storage, an error could occur which would either fail an assertion or
      cause file corruption. Fixed and added test.

      (NAF - 2017/11/14, HDFFV-10274)

    - Updated H5Zfilter_avail in H5Z.c.

      The public function checked for plugins, while the private
      function did not.

      Modified H5Zfilter_avail and private function, H5Z_filter_avail.
      Moved check for plugin from public to private function. Updated
      H5P__set_filter due to change in H5Z_filter_avail. Updated tests.

      (ADB - 2017/10/10, HDFFV-10297, HDFFV-10319)

    - h5dump produced SEGFAULT when dumping corrypted file.

      The behavior was due to the error in the internal function H5HL_offset_into().

      (1) Fixed H5HL_offset_into() to return error when offset exceeds heap data
          block size.
      (2) Fixed other places in the library that call this routine to detect
          error routine.

      (VC - 2017/08/30, HDFFV-10216)

    - Fixes for paged aggregation feature.

      Skip test in test/fheap.c when:
      (1) multi/split drivers and
      (2) persisting free-space or using paged aggregation strategy

      (VC, 2017/07/10)

      Changes made based on RFC review comments:
      (1) Added maximum value for file space page size
      (2) Dropped check for page end metadata threshold
      (3) Removed "can_shrink" and "shrink" callbacks for small section class

      (VC - 2017/06/09)

    - Fixed for infinite loop in H5VM_power2up().

      The function H5VM_power2up() returns the next power of 2
      for n. When n exceeds 2^63, it overflows and becomes 0 causing
      the infinite looping.

      The fix ensures that the function checks for n >= 2^63
      and returns 0.

      (VC - 2017/07/10, HDFFV-10217)

    - Fixed for H5Ocopy doesn't work with open identifiers.

      Changes made so that raw data for dataset objects are copied from
      cached info when possible instead of flushing objects to file and
      read them back in again.

      (VC - 2017/07/05, HDFFV-7853)

    - An uninitialized struct could cause a memory access error when using
      variable-length or reference types in a compressed, chunked dataset.

      A struct containing a callback function pointer and a pointer to some
      associated data was used before initialization. This could cause a
      memory access error and system crash. This could only occur under
      unusual conditions when using variable-lenth and reference types in
      a compressed, chunked dataset.

      On recent versions of Visual Studio, when built in debug mode, the
      debug heap will complain and cause a crash if the code in question
      is executed (this will cause the objcopy test to fail).

      (DER - 2017/11/21, HDFFV-10330)

    - Fixed collective metadata writes on file close.

      It was discovered that metadata was being written twice as part of
      the parallel file close behavior, once independently and once
      collectively.

      A fix for this error was included as part of the parallel compression
      feature but remained undocumented here.

      (RAW - 2017/12/01, HDFFV-10272)

    - If an HDF5 file contains a filter pipeline message with a 'number of
      filters' field that exceeds the maximum number of allowed filters,
      the error handling code will attempt to dereference a NULL pointer.

      This issue was reported to The HDF Group as issue #CVE-2017-17505.
          https://security-tracker.debian.org/tracker/CVE-2017-17505
          https://cve.mitre.org/cgi-bin/cvename.cgi?name=3DCVE-2017-17505

      NOTE: The HDF5 C library cannot produce such a file. This condition
            should only occur in a corrupt (or deliberately altered) file
            or a file created by third-party software.

      This problem arose because the error handling code assumed that
      the 'number of filters' field implied that a dynamic array of that
      size had already been created and that the cleanup code should
      iterate over that array and clean up each element's resources. If
      an error occurred before the array has been allocated, this will
      not be true.

      This has been changed so that the number of filters is set to
      zero on errors. Additionally, the filter array traversal in the
      error handling code now requires that the filter array not be NULL.

      (DER - 2018/02/06, HDFFV-10354)

    - If an HDF5 file contains a filter pipeline message which contains
      a 'number of filters' field that exceeds the actual number of
      filters in the message, the HDF5 C library will read off the end of
      the read buffer.

      This issue was reported to The HDF Group as issue #CVE-2017-17506.
          https://security-tracker.debian.org/tracker/CVE-2017-17506
          https://cve.mitre.org/cgi-bin/cvename.cgi?name=3DCVE-2017-17506

      NOTE: The HDF5 C library cannot produce such a file. This condition
            should only occur in a corrupt (or deliberately altered) file
            or a file created by third-party software.

      The problem was fixed by passing the buffer size with the buffer
      and ensuring that the pointer cannot be incremented off the end
      of the buffer. A mismatch between the number of filters declared
      and the actual number of filters will now invoke normal HDF5
      error handling.

      (DER - 2018/02/26, HDFFV-10355)

    - If an HDF5 file contains a malformed compound datatype with a
      suitably large offset, the type conversion code can run off
      the end of the type conversion buffer, causing a segmentation
      fault.

      This issue was reported to The HDF Group as issue #CVE-2017-17507.
          https://security-tracker.debian.org/tracker/CVE-2017-17506
          https://cve.mitre.org/cgi-bin/cvename.cgi?name=3DCVE-2017-17506

      NOTE: The HDF5 C library cannot produce such a file. This condition
            should only occur in a corrupt (or deliberately altered) file
            or a file created by third-party software.

      THE HDF GROUP WILL NOT FIX THIS BUG AT THIS TIME

      Fixing this problem would involve updating the publicly visible
      H5T_conv_t function pointer typedef and versioning the API calls
      which use it. We normally only modify the public API during
      major releases, so this bug will not be fixed at this time.

      (DER - 2018/02/26, HDFFV-10356)

    - If an HDF5 file contains a malformed compound type which contains
      a member of size zero, a division by zero error will occur while
      processing the type.

      This issue was reported to The HDF Group as issue #CVE-2017-17508.
          https://security-tracker.debian.org/tracker/CVE-2017-17508
          https://cve.mitre.org/cgi-bin/cvename.cgi?name=3DCVE-2017-17508

      NOTE: The HDF5 C library cannot produce such a file. This condition
            should only occur in a corrupt (or deliberately altered) file
            or a file created by third-party software.

      Checking for zero before dividing fixes the problem. Instead of the
      division by zero, the normal HDF5 error handling is invoked.

      (DER - 2018/02/26, HDFFV-10357)

    - If an HDF5 file contains a malformed symbol table node that declares
      it contains more symbols than it actually contains, the library
      can run off the end of the metadata cache buffer while processing
      the symbol table node.

      This issue was reported to The HDF Group as issue #CVE-2017-17509.
          https://security-tracker.debian.org/tracker/CVE-2017-17509
          https://cve.mitre.org/cgi-bin/cvename.cgi?name=3DCVE-2017-17509

      NOTE: The HDF5 C library cannot produce such a file. This condition
            should only occur in a corrupt (or deliberately altered) file
            or a file created by third-party software.

      Performing bounds checks on the buffer while processing fixes the
      problem. Instead of the segmentation fault, the normal HDF5 error
      handling is invoked.

      (DER - 2018/03/12, HDFFV-10358)

    - Fixed permissions passed to open(2) on file create.

      On Windows, the POSIX permissions passed to open(2) when creating files
      were only incidentally correct. They are now set to the correct value of
      (_S_IREAD | _S_IWRITE).

      On other platforms, the permissions were set to a mix of 666, 644, and
      000. They are now set uniformly to 666.

      (DER - 2017/04/28, HDFFV-9877)

    - The H5FD_FEAT_POSIX_COMPAT_HANDLE flag is no longer used to determine
      if a virtual file driver (VFD) is compatible with SWMR.

      Use of this VFD feature flag was not in line with the documentation in
      the public H5FDpublic.h file. In particular, it was being used as a
      proxy for determining if SWMR I/O is allowed. This is unnecessary as we
      already have a feature flag for this (H5FD_SUPPORTS_SWMR_IO).

      (DER - 2017/05/31, HDFFV-10214)


    Configuration
    -------------
    - CMake changes

       - Updated CMake commands configuration.

      A number of improvements were made to the CMake commands. Most
      changes simplify usage or eliminate unused constructs. Also,
      some changes support better cross-platform support.

      (ADB - 2018/02/01, HDFFV-10398)

       - Corrected usage of CMAKE_BUILD_TYPE variable.

      The use of the CMAKE_BUILD_TYPE is incorrect for multi-config
      generators (Visual Studio and XCode) and is optional for single
      config generators. Created a new macro to check
        GLOBAL PROPERTY -> GENERATOR_IS_MULTI_CONFIG
      Created two new HDF variable, HDF_BUILD_TYPE and HDF_CFG_BUILD_TYPE.
      Defaults for these variables is "Release".

      (ADB - 2018/01/10, HDFFV-10385)

       - Added replacement of fortran flags if using static CRT.

      Added TARGET_STATIC_CRT_FLAGS call to HDFUseFortran.cmake file in
      config/cmake_ext_mod folder.

      (ADB - 2018/01/08, HDFFV-10334)


       - The hdf5 library used shared szip and zlib, which needlessly required
      applications to link with the same szip and zlib libraries.

      Changed the target_link_libraries commands to use the static libs.
      Removed improper link duplication of szip and zlib.
      Adjusted the link dependencies and the link interface values of
      the target_link_libraries commands.

      (ADB - 2017/11/14, HDFFV-10329)

    - CMake MPI

      CMake implementation for MPI was problematic and would create incorrect
      MPI library references in the hdf5 libraries.

      Reworked the CMake MPI code to properly create CMake targets. Also merged
      the latest CMake FindMPI.cmake changes to the local copy. This is necessary
      until HDF changes the CMake minimum to 3.9 or greater.

      (ADB - 2017/11/02, HDFFV-10321)

    - Corrected FORTRAN_HAVE_C_LONG_DOUBLE processing in the autotools.

      A bug in the autotools Fortran processing code always set the
      FORTRAN_HAVE_C_LONG_DOUBLE variable to be true regardless of
      whether or not a C long double type was present.

      This would cause compilation failures on platforms where a C
      long double type was not available and the Fortran wrappers
      were being built.

      (DER - 2017/07/05, HDFFV-10247)

    - The deprecated --enable-production and --enable-debug configure options
      failed to emit errors when passed an empty string
      (e.g.: --enable-debug="").

      Due to the way we checked for these options being set, it was possible
      to avoid the error message and continue configuration if an empty string
      was passed to the option.

      Any use of --enable-production or --enable-debug will now halt the
      configuration step and emit a helpful error message
      (use --enable-build-mode=debug|production instead).

      (DER - 2017/07/05, HDFFV-10248)

    - CMake

      Too many commands for POST_BUILD step caused command line to be
      too big on windows.

      Changed foreach of copy command to use a custom command with the
      use of the HDFTEST_COPY_FILE macro.

      (ADB - 2017/07/12, HDFFV-10254)

    - CMake test execution environment

      The parallel HDF5 test: 't_pread' assumed the use of autotools
      and the directory structure associated with that testing approach.
      Modified the test code to check whether the 'h5jam' utility can be
      found in the same directory as the test executable (which is
      preferred directory structure utilized by cmake) and if found
      will invoke the tool directly rather than utilizing a relative path.

      (RAW - 2017/11/03, HDFFV-10318)

    - Fortran compilation fails for xlf and CMake builds.

      Fixed CMake shared library build for H5match_types and modules

      (MSB - 2017/12/19, HDFFV-10363)

    - Shared libraries fail test on OSX with Fortran enabled with CMake.

      Fixed by removing the F77 use of EQUIVALENCE and COMMON, replaced
      using MODULES. Updated CMake.

      (MSB - 2017/12/07, HDFFV-10223)

    - The bin/trace script now emits an error code on problems and autogen.sh
      will fail if bin/trace fails.

      The bin/trace script adds tracing functionality to public HDF5 API calls.
      It is only of interest to developers who modify the HDF5 source code.
      Previously, bin/trace just wrote an error message to stdout when it
      encountered problems, so autogen.sh processing did not halt and a broken
      version of the library could be built. The script will now return an
      error code when it encounters problems, and autogen.sh will fail.

      This only affects users who run autogen.sh to rebuild the Autotools files,
      which is not necessary to build HDF5 from source in official releases of the
      library. CMake users are unaffected as bin/trace is not run via CMake
      at this time.

      (DER - 2017/04/25, HDFFV-10178)

    - FC_BASENAME was changed from gfortran40 to gfortran in a few places.

      In the autotools, FC_BASENAME was set to gfortran40 in a few locations
      (config/gnu-fflags and config/freebsd). This was probably a historical
      artifact and did not seem to affect many users.

      The value is now correctly set to gfortran.

      (DER - 2017/05/26, HDFFV-10249)

    - The ar flags were changed to -cr (was: -cru)

      The autotools set the flags for ar to -cru by default. The -u flag,
      which allows selective replacement of only the members which have
      changed, raises warnings on some platforms, so the flags are now set to
      -cr via AR_FLAGS in configure.ac. This causes the static library to
      always be completely recreated from the object files on each build.

      (DER - 2017/11/15, HDFFV-10428)


    Fortran
    --------
    - Fixed compilation errors when using Intel 18 Fortran compilers
      (MSB - 2017/11/3, HDFFV-10322)

    Tools
    -----
    - h5clear

      An enhancement to the tool in setting a file's stored EOA.

      It was discovered that a crashed file's stored EOA in the superblock
      was smaller than the actual file's EOF.  When the file was reopened
      and closed, the library truncated the file to the stored EOA.

      Added an option to the tool in setting the file's stored EOA in the
      superblock to the maximum of (EOA, EOF) + increment.
      An option was also added to print the file's EOA and EOF.

      (VC - 2018/03/14, HDFFV-10360)

    - h5repack

      h5repack changes the chunk parameters when a change of layout is not
      specified and a filter is applied.

      HDFFV-10297, HDFFV-10319 reworked code for h5repack and h5diff code
      in the tools library. The check for an existing layout was incorrectly
      placed into an if block and not executed. The check was moved into
      the normal path of the function.

      (ADB - 2018/02/21, HDFFV-10412)

    - h5dump

      The tools library will hide the error stack during file open.

      While this is preferable almost always, there are reasons to enable
      display of the error stack when a tool will not open a file. Adding an
      optional argument to the --enable-error-stack will provide this use case.
      As an optional argument it will not affect the operation of the
      --enable-error-stack. h5dump is the only tool to implement this change.

      (ADB - 2018/02/15, HDFFV-10384)

    - h5dump

      h5dump would output an indented blank line in the filters section.

      h5dump overused the h5tools_simple_prefix function, which is a
      function intended to account for the data index (x,y,z) option.
      Removed the function call for header information.

      (ADB - 2018/01/25, HDFFV-10396)

    - h5repack

      h5repack incorrectly searched internal object table for name.

      h5repack would search the table of objects for a name, if the
      name did not match it tried to determine if the name without a
      leading slash would match. The logic was flawed! The table
      stored names(paths) without a leading slash and did a strstr
      of the table path to the name.
      The assumption was that if there was a difference of one then
      it was a match, however "pressure" would match "/pressure" as
      well as "/pressure1", "/pressure2", etc. Changed logic to remove
      any leading slash and then do a full compare of the name.

      (ADB - 2018/01/18, HDFFV-10393)

    - h5repack

      h5repack failed to handle command line parameters for customer filters.

      User defined filter parameter conversions would fail when integers were
      represented on the command line with character string
      larger then 9 characters. Increased local variable array for storing
      the current command line parameter to prevent buffer overflows.

      (ADB - 2018/01/17, HDFFV-10392)

    - h5diff

      h5diff seg faulted if comparing VL strings against fixed strings.

      Reworked solution for HDFFV-8625 and HDFFV-8639. Implemented the check
      for string objects of same type in the diff_can_type function by
      adding an if(tclass1 == H5T_STRING) block. This "if block" moves the
      same check that was added for attributes to this function, which is
      used by all object types. This function handles complex type structures.
      Also added a new test file in h5diffgenttest for testing this issue
      and removed the temporary files used in the test scripts.

      (ADB - 2018/01/04, HDFFV-8745)

    - h5repack

      h5repack failed to copy a dataset with existing filter.

      Reworked code for h5repack and h5diff code in the tools library. Added
      improved error handling, cleanup of resources and checks of calls.
      Modified H5Zfilter_avail and private function, H5Z_filter_avail.
      Moved check for plugin from public to private function. Updated
      H5P__set_filter due to change in H5Z_filter_avail. Updated tests.
      Note, h5repack output display has changed to clarify the individual
      steps of the repack process. The output indicates if an operation
      applies to all objects. Lines with notation and no information
      have been removed.

      (ADB - 2017/10/10, HDFFV-10297, HDFFV-10319)

    - h5repack

      h5repack always set the User Defined filter flag to H5Z_FLAG_MANDATORY.

      Added another parameter to the 'UD=' option to set the flag by default
      to '0' or H5Z_FLAG_MANDATORY, the other choice is '1' or H5Z_FLAG_OPTIONAL.

      (ADB - 2017/08/31, HDFFV-10269)

    - h5ls

      h5ls generated error on stack when it encountered a H5S_NULL
      dataspace.

      Adding checks for H5S_NULL before calling H5Sis_simple (located
      in the h5tools_dump_mem function) fixed the issue.

      (ADB - 2017/08/17, HDFFV-10188)

    - h5repack

      Added tests to h5repack.sh.in to verify options added for paged
      aggregation work as expected.

      (VC - 2017/08/03)

    - h5dump

      h5dump segfaulted on output of XML file.

      Function that escape'd strings used the full buffer length
      instead of just the length of the replacement string in a
      strncpy call. Using the correct length fixed the issue.

      (ADB - 2017/08/01, HDFFV-10256)

    - h5diff

      h5diff segfaulted on compare of a  NULL variable length string.

      Improved h5diff compare of strings by adding a check for
      NULL strings and setting the lengths to zero.

      (ADB - 2017/07/25, HDFFV-10246)

    - h5import

      h5import crashed trying to import data from a subset of a dataset.

      Improved h5import by adding the SUBSET keyword. h5import understands
      to use the Count times the Block as the size of the dimensions.
      Added INPUT_B_ORDER keyword to old-style configuration files.
      The import from h5dump function expects the binary files to use native
      types (FILE '-b' option) in the binary file.

      (ADB - 2017/06/15, HDFFV-10219)

    - h5repack

      h5repack did not maintain the creation order flag of the root
      group.

      Improved h5repack by reading the creation order and applying the
      flag to the new root group. Also added arguments to set the
      order and index direction, which applies to the traversing of the
      original file, on the command line.

      (ADB - 2017/05/26, HDFFV-8611)

    - h5diff

      h5diff failed to account for strpad type and null terminators
      of char strings. Also, h5diff failed to account for string length
      differences and would give a different result depending on file
      order in the command line.

      Improved h5diff compare of strings and arrays by adding a check for
      string lengths and if the strpad was null filled.

      (ADB - 2017/05/18, HDFFV-9055, HDFFV-10128)

    High-Level APIs:
    ------
    - H5DOwrite_chunk() problems when overwriting an existing chunk with
      no filters enabled.

      When overwriting chunks and no filters were being used, the library would
      fail (when asserts are enabled, e.g. debug builds) or incorrectly
      insert additional chunks instead of overwriting (when asserts are not
      enabled, e.g. production builds).

      This has been fixed and a test was added to the hl/test_dset_opt test.

      (DER - 2017/05/11, HDFFV-10187)

    C++ APIs
    --------
    - Removal of memory leaks.

      A private function was inadvertently called, causing memory leaks.  This
      is now fixed.

      (BMR - 2018/03/12 - User's reported in email)

    Testing
    -------
    - Memory for three variables in testphdf5's coll_write_test was malloced
      but not freed, leaking memory when running the test.

      The variables' memory is now freed.

      (LRK - 2018/03/12, HDFFV-10397)

    - Refactored the testpar/t_bigio.c test to include ALARM macros

      Changed the test to include the ALARM_ON and ALARM_OFF macros which
      are intended to prevent nightly test hangs that have been observed
      with this particular parallel test example.  The code was also modified to
      simplify status reporting (only from MPI rank 0) and additional
      status checking added.

      (RAW - 2017/11/08, HDFFV-10301)


Supported Platforms
===================

    Linux 2.6.32-696.16.1.el6.ppc64 gcc (GCC) 4.4.7 20120313 (Red Hat 4.4.7-18)
    #1 SMP ppc64 GNU/Linux        g++ (GCC) 4.4.7 20120313 (Red Hat 4.4.7-18)
    (ostrich)                     GNU Fortran (GCC) 4.4.7 20120313 (Red Hat 4.4.7-18)
                                  IBM XL C/C++ V13.1
                                  IBM XL Fortran V15.1

    Linux 3.10.0-327.10.1.el7   GNU C (gcc), Fortran (gfortran), C++ (g++)
    #1 SMP x86_64 GNU/Linux       compilers:
    (kituo/moohan)                Version 4.8.5 20150623 (Red Hat 4.8.5-4)
                                    Version 4.9.3, Version 5.2.0,
                                  Intel(R) C (icc), C++ (icpc), Fortran (icc)
                                  compilers:
                                     Version 17.0.0.098 Build 20160721
                                  MPICH 3.1.4 compiled with GCC 4.9.3

    SunOS 5.11 32- and 64-bit     Sun C 5.12 SunOS_sparc
    (emu)                         Sun Fortran 95 8.6 SunOS_sparc
                                  Sun C++ 5.12 SunOS_sparc

    Windows 7                     Visual Studio 2012 w/ Intel Fortran 15 (cmake)
                                  Visual Studio 2013 w/ Intel Fortran 15 (cmake)
                                  Visual Studio 2015 w/ Intel Fortran 16 (cmake)

    Windows 7 x64                 Visual Studio 2012 w/ Intel Fortran 15 (cmake)
                                  Visual Studio 2013 w/ Intel Fortran 15 (cmake)
                                  Visual Studio 2015 w/ Intel Fortran 16 (cmake)
                                  Visual Studio 2015 w/ Intel C, Fortran 2017 (cmake)
                                  Visual Studio 2015 w/ MSMPI 8 (cmake)
                                  Cygwin(CYGWIN_NT-6.1 2.8.0(0.309/5/3)
                                      gcc and gfortran compilers (GCC 5.4.0)
                                      (cmake and autotools)

    Windows 10                    Visual Studio 2015 w/ Intel Fortran 16 (cmake)
                                  Cygwin(CYGWIN_NT-6.1 2.8.0(0.309/5/3)
                                      gcc and gfortran compilers (GCC 5.4.0)
                                      (cmake and autotools)

    Windows 10 x64                Visual Studio 2015 w/ Intel Fortran 16 (cmake)

    Mac OS X Yosemite 10.10.5     Apple clang/clang++ version 6.1 from Xcode 7.0
    64-bit                        gfortran GNU Fortran (GCC) 4.9.2
    (osx1010dev/osx1010test)      Intel icc/icpc/ifort version 15.0.3

    Mac OS X El Capitan 10.11.6   Apple clang/clang++ version 7.3.0 from Xcode 7.3
    64-bit                        gfortran GNU Fortran (GCC) 5.2.0
    (osx1011dev/osx1011test)      Intel icc/icpc/ifort version 16.0.2

    Mac OS Sierra 10.12.6         Apple LLVM version 8.1.0 (clang/clang++-802.0.42)
    64-bit                        gfortran GNU Fortran (GCC) 7.1.0
    (swallow/kite)                Intel icc/icpc/ifort version 17.0.2


Tested Configuration Features Summary
=====================================

    In the tables below
          y   = tested
          n   = not tested in this release
          C   = Cluster
          W   = Workstation
          x   = not working in this release
          dna = does not apply
          ( ) = footnote appears below second table
          <blank> = testing incomplete on this feature or platform

Platform                              C         F90/   F90      C++  zlib  SZIP
                                      parallel  F2003  parallel
Solaris2.11 32-bit                      n        y/y    n        y    y     y
Solaris2.11 64-bit                      n        y/n    n        y    y     y
Windows 7                               y        y/y    n        y    y     y
Windows 7 x64                           y        y/y    y        y    y     y
Windows 7 Cygwin                        n        y/n    n        y    y     y
Windows 7 x64 Cygwin                    n        y/n    n        y    y     y
Windows 10                              y        y/y    n        y    y     y
Windows 10 x64                          y        y/y    n        y    y     y
Mac OS X Mountain Lion 10.8.5 64-bit    n        y/y    n        y    y     y
Mac OS X Mavericks 10.9.5 64-bit        n        y/y    n        y    y     y
Mac OS X Yosemite 10.10.5 64-bit        n        y/y    n        y    y     y
Mac OS X El Capitan 10.11.6 64-bit      n        y/y    n        y    y     y
CentOS 7.2 Linux 2.6.32 x86_64 PGI      n        y/y    n        y    y     y
CentOS 7.2 Linux 2.6.32 x86_64 GNU      y        y/y    y        y    y     y
CentOS 7.2 Linux 2.6.32 x86_64 Intel    n        y/y    n        y    y     y
Linux 2.6.32-573.18.1.el6.ppc64         n        y/y    n        y    y     y


Platform                                 Shared  Shared    Shared    Thread-
                                         C libs  F90 libs  C++ libs  safe
Solaris2.11 32-bit                         y       y         y         y
Solaris2.11 64-bit                         y       y         y         y
Windows 7                                  y       y         y         y
Windows 7 x64                              y       y         y         y
Windows 7 Cygwin                           n       n         n         y
Windows 7 x64 Cygwin                       n       n         n         y
Windows 10                                 y       y         y         y
Windows 10 x64                             y       y         y         y
Mac OS X Mountain Lion 10.8.5 64-bit       y       n         y         y
Mac OS X Mavericks 10.9.5 64-bit           y       n         y         y
Mac OS X Yosemite 10.10.5 64-bit           y       n         y         y
Mac OS X El Capitan 10.11.6 64-bit         y       n         y         y
CentOS 7.2 Linux 2.6.32 x86_64 PGI         y       y         y         n
CentOS 7.2 Linux 2.6.32 x86_64 GNU         y       y         y         y
CentOS 7.2 Linux 2.6.32 x86_64 Intel       y       y         y         n
Linux 2.6.32-573.18.1.el6.ppc64            y       y         y         n

Compiler versions for each platform are listed in the preceding
"Supported Platforms" table.


More Tested Platforms
=====================
The following platforms are not supported but have been tested for this release.

    Linux 2.6.32-573.22.1.el6    GNU C (gcc), Fortran (gfortran), C++ (g++)
    #1 SMP x86_64 GNU/Linux       compilers:
    (mayll/platypus)                 Version 4.4.7 20120313
                                     Version 4.9.3, 5.3.0, 6.2.0
                                  PGI C, Fortran, C++ for 64-bit target on
                                  x86-64;
                                      Version 17.10-0
                                  Intel(R) C (icc), C++ (icpc), Fortran (icc)
                                  compilers:
                                     Version 17.0.4.196 Build 20170411
                                  MPICH 3.1.4 compiled with GCC 4.9.3

    Linux 3.10.0-327.18.2.el7     GNU C (gcc) and C++ (g++) compilers
    #1 SMP x86_64 GNU/Linux          Version 4.8.5 20150623 (Red Hat 4.8.5-4)
    (jelly)                       with NAG Fortran Compiler Release 6.1(Tozai)
                                  GCC Version 7.1.0
                                  OpenMPI 3.0.0-GCC-7.2.0-2.29
                                  Intel(R) C (icc) and C++ (icpc) compilers
                                     Version 17.0.0.098 Build 20160721
                                  with NAG Fortran Compiler Release 6.1(Tozai)

    Linux 3.10.0-327.10.1.el7     MPICH 3.2 compiled with GCC 5.3.0
    #1 SMP x86_64 GNU/Linux
    (moohan)

    Linux 2.6.32-573.18.1.el6.ppc64  MPICH mpich 3.1.4 compiled with
    #1 SMP ppc64 GNU/Linux           IBM XL C/C++ for Linux, V13.1
    (ostrich)                        and IBM XL Fortran for Linux, V15.1

    Debian 8.4 3.16.0-4-amd64 #1 SMP Debian 3.16.36-1 x86_64 GNU/Linux
                                  gcc, g++ (Debian 4.9.2-10) 4.9.2
                                  GNU Fortran (Debian 4.9.2-10) 4.9.2
                                  (cmake and autotools)

    Fedora 24  4.7.2-201.fc24.x86_64 #1 SMP x86_64 x86_64 x86_64 GNU/Linux
                                  gcc, g++ (GCC) 6.1.1 20160621
                                      (Red Hat 6.1.1-3)
                                  GNU Fortran (GCC) 6.1.1 20160621
                                      (Red Hat 6.1.1-3)
                                  (cmake and autotools)

    Ubuntu 16.04.1 4.4.0-38-generic #57-Ubuntu SMP x86_64 GNU/Linux
                                  gcc, g++ (Ubuntu 5.4.0-6ubuntu1~16.04.2)
                                      5.4.0 20160609
                                  GNU Fortran (Ubuntu 5.4.0-6ubuntu1~16.04.2)
                                      5.4.0 20160609
                                  (cmake and autotools)


Known Problems
==============

    At present, metadata cache images may not be generated by parallel
    applications.  Parallel applications can read files with metadata cache
    images, but since this is a collective operation, a deadlock is possible
    if one or more processes do not participate.

    Three tests fail with OpenMPI 3.0.0/GCC-7.2.0-2.29:
        testphdf5 (ecdsetw, selnone, cchunk1, cchunk3, cchunk4, and actualio)
        t_shapesame (sscontig2)
        t_pflush1/fails on exit
    The first two tests fail attempting collective writes.

    Known problems in previous releases can be found in the HISTORY*.txt files
    in the HDF5 source. Please report any new problems found to
    help@hdfgroup.org.


%%%%1.10.1%%%%

HDF5 version 1.10.1 released on 2017-04-27
================================================================================

INTRODUCTION

This document describes the differences between HDF5-1.10.0-patch1 and
HDF5 1.10.1, and contains information on the platforms tested and known
problems in HDF5-1.10.1. For more details check the HISTORY*.txt files
in the HDF5 source.

Links to HDF5 1.10.1 source code, documentation, and additional materials can
be found on The HDF5 web page at:

     https://support.hdfgroup.org/HDF5/

The HDF5 1.10.1 release can be obtained from:

     https://support.hdfgroup.org/HDF5/release/obtain5.html

User documentation for the snapshot can be accessed directly at this location:

     https://support.hdfgroup.org/HDF5/doc/

New features in the HDF5-1.10.x release series, including brief general
descriptions of some new and modified APIs, are described in the "New Features
in HDF5 Release 1.10" document:

     https://support.hdfgroup.org/HDF5/docNewFeatures/index.html

All new and modified APIs are listed in detail in the "HDF5 Software Changes
from Release to Release" document, in the section "Release 10.1 (current
release) versus Release 1.10.0

     https://support.hdfgroup.org/HDF5/doc/ADGuide/Changes.html

If you have any questions or comments, please send them to the HDF Help Desk:

    help@hdfgroup.org


CONTENTS

- Major New Features Introduced in HDF5 1.10.1
- Other New Features and Enhancements
- Support for New Platforms, Languages, and Compilers
- Bug Fixes since HDF5-1.10.0-patch1
- Supported Platforms
- Tested Configuration Features Summary
- More Tested Platforms
- Known Problems


Major New Features Introduced in HDF5 1.10.1
============================================

For links to the RFCs and documentation in this section please view
https://support.hdfgroup.org/HDF5/docNewFeatures in a web browser.

________________________________________
Metadata Cache Image
________________________________________

    HDF5 metadata is typically small, and scattered throughout the HDF5 file.
    This can affect performance, particularly on large HPC systems. The
    Metadata Cache Image feature can improve performance by writing the
    metadata cache in a single block on file close, and then populating the
    cache with the contents of this block on file open, thus avoiding the many
    small I/O operations that would otherwise be required on file open and
    close. See the RFC for complete details regarding this feature. Also,
    see the Fine Tuning the Metadata Cache documentation.

    At present, metadata cache images may not be generated by parallel
    applications.  Parallel applications can read files with metadata cache
    images, but since this is a collective operation, a deadlock is possible
    if one or more processes do not participate.

________________________________________
Metadata Cache Evict on Close
________________________________________

    The HDF5 library's metadata cache is fairly conservative about holding on
    to HDF5 object metadata (object headers, chunk index structures, etc.),
    which can cause the cache size to grow, resulting in memory pressure on
    an application or system. The "evict on close" property will cause all
    metadata for an object to be evicted from the cache as long as metadata
    is not referenced from any other open object. See the Fine Tuning the
    Metadata Cache documentation for information on the APIs.

    At present, evict on close is disabled in parallel builds.

________________________________________
Paged Aggregation
________________________________________

    The current HDF5 file space allocation accumulates small pieces of metadata
    and raw data in aggregator blocks which are not page aligned and vary
    widely in sizes. The paged aggregation feature was implemented to provide
    efficient paged access of these small pieces of metadata and raw data.
    See the RFC for details. Also, see the File Space Management documentation.

________________________________________
Page Buffering
________________________________________

    Small and random I/O accesses on parallel file systems result in poor
    performance for applications. Page buffering in conjunction with paged
    aggregation can improve performance by giving an application control of
    minimizing HDF5 I/O requests to a specific granularity and alignment.
    See the RFC for details. Also, see the Page Buffering documentation.

    At present, page buffering is disabled in parallel builds.



Other New Features and Enhancements
===================================

    Library
    -------
    - Added a mechanism for disabling the SWMR file locking scheme.

      The file locking calls used in HDF5 1.10.0 (including patch1)
      will fail when the underlying file system does not support file
      locking or where locks have been disabled. To disable all file
      locking operations, an environment variable named
      HDF5_USE_FILE_LOCKING can be set to the five-character string
      'FALSE'. This does not fundamentally change HDF5 library
      operation (aside from initial file open/create, SWMR is lock-free),
      but users will have to be more careful about opening files
      to avoid problematic access patterns (i.e.: multiple writers)
      that the file locking was designed to prevent.

      Additionally, the error message that is emitted when file lock
      operations set errno to ENOSYS (typical when file locking has been
      disabled) has been updated to describe the problem and potential
      resolution better.

      (DER, 2016/10/26, HDFFV-9918)

    - The return type of H5Pget_driver_info() has been changed from void *
      to const void *.

      The pointer returned by this function points to internal library
      memory and should not be freed by the user.

      (DER, 2016/11/04, HDFFV-10017)

    - The direct I/O VFD has been removed from the list of VFDs that
      support SWMR.

      This configuration was never officially tested and several SWMR
      tests fail when this VFD is set.

      (DER, 2016/11/03, HDFFV-10169)

    Configuration:
    --------------
    - The minimum version of CMake required to build HDF5 is now 3.2.2.

      (ADB, 2017/01/10)

    - An --enable/disable-developer-warnings option has been added to
      configure.

      This disables warnings that do not indicate poor code quality such
      as -Winline and gcc's -Wsuggest-attribute. Developer warnings are
      disabled by default.

      (DER, 2017/01/10)

    - A bin/restore.sh script was added that reverts autogen.sh processing.

      (DER, 2016/11/08)

    - CMake: Added NAMESPACE hdf5:: to package configuration files to allow
      projects using installed HDF5 binaries built with CMake to link with
      them without specifying the HDF5 library location via IMPORTED_LOCATION.

      (ABD, 2016/10/17, HDFFV-10003)

    - CMake: Changed the CTEST_BUILD_CONFIGURATION option to
      CTEST_CONFIGURATION_TYPE as recommended by the CMake documentation.

      (ABD, 2016/10/17, HDFFV-9971)


    Fortran Library:
    ----------------

    - The HDF5 Fortran library can now be compiled with the NAG compiler.

      (MSB, 2017/2/10, HDFFV-9973)


    C++ Library:
    ------------

    - The following C++ API wrappers have been added to the C++ Library:

        // Sets/Gets the strategy and the threshold value that the library
        // will employ in managing file space.
        FileCreatPropList::setFileSpaceStrategy - H5Pset_file_space_strategy
        FileCreatPropList::getFileSpaceStrategy - H5Pget_file_space_strategy

        // Sets/Gets the file space page size for paged aggregation.
        FileCreatPropList::setFileSpacePagesize - H5Pset_file_space_page_size
        FileCreatPropList::getFileSpacePagesize - H5Pget_file_space_page_size

        // Checks if the given ID is valid.
        IdComponent::isValid - H5Iis_valid

        // Sets/Gets the number of soft or user-defined links that can be
        // traversed before a failure occurs.
        LinkAccPropList::setNumLinks - H5Pset_nlinks
        LinkAccPropList::getNumLinks - H5Pget_nlinks

        // Returns a copy of the creation property list of a datatype.
        DataType::getCreatePlist - H5Tget_create_plist

        // Opens/Closes an object within a group or a file, regardless of object
        // type
        Group::getObjId - H5Oopen
        Group::closeObjId - H5Oclose

        // Maps elements of a virtual dataset to elements of the source dataset.
        DSetCreatPropList::setVirtual - H5Pset_virtual

        // Gets general information about this file.
        H5File::getFileInfo - H5Fget_info2

        // Returns the number of members in a type.
        IdComponent::getNumMembers - H5Inmembers

        // Determines if an element type exists.
        IdComponent::typeExists - H5Itype_exists

        // Determines if an object exists.
        H5Location::exists - H5Lexists.

        // Returns the header version of an HDF5 object.
        H5Object::objVersion - H5Oget_info for version

      (BMR, 2017/03/20, HDFFV-10004, HDFFV-10139, HDFFV-10145)

    - New exception: ObjHeaderIException for H5O interface.

      (BMR, 2017/03/15, HDFFV-10145)

    - New class LinkAccPropList for link access property list, to be used by
      wrappers of H5Lexists.

      (BMR, 2017/01/04, HDFFV-10145)

    - New constructors to open datatypes in ArrayType, CompType, DataType,
      EnumType, FloatType, IntType, StrType, and VarLenType.

      (BMR, 2016/12/26, HDFFV-10056)

    - New member functions:

        DSetCreatPropList::setNbit() to setup N-bit compression for a dataset.

        ArrayType::getArrayNDims() const
        ArrayType::getArrayDims() const
        both to replace the non-const versions.

      (BMR, 2016/04/25, HDFFV-8623, HDFFV-9725)


    Tools:
    ------
     - The following options have been added to h5clear:
       -s: clear the status_flags field in the file's superblock
       -m: Remove the metadata cache image from the file

       (QAK, 2017/03/22, PR#361)


    High-Level APIs:
    ---------------
     - Added New Fortran 2003 API for h5tbmake_table_f.

       (MSB, 2017/02/10, HDFFV-8486)



Support for New Platforms, Languages, and Compilers
===================================================

    - Added NAG compiler



Bug Fixes since HDF5-1.10.0-patch1 release
==================================

    Library
    -------
    - Outdated data structure was used in H5D_CHUNK_DEBUG blocks, causing
      compilation errors when H5D_CHUNK_DEBUG was defined.  This is fixed.

      (BMR, 2017/04/04, HDFFV-8089)

    - SWMR implementation in the HDF5 1.10.0 and 1.10.0-patch1 releases has a
      broken metadata flush dependency that manifested itself with the following
      error at the end of the HDF5 error stack:

      H5Dint.c line 846 in H5D__swmr_setup(): dataspace chunk index must be 0
      for SWMR access, chunkno = 1
      major: Dataset
      minor: Bad value

      It was also reported at https://github.com/areaDetector/ADCore/issues/203

      The flush dependency is fixed in this release.

    - Changed the plugins dlopen option from RTLD_NOW to RTLD_LAZY

      (ABD, 2016/12/12, PR#201)

    - A number of issues were fixed when reading/writing from/to corrupted
      files to ensure that the library fails gracefully in these cases:

      * Writing to a corrupted file that has an object message which is
        incorrectly marked as shareable on disk results in a buffer overflow /
        invalid write instead of a clean error message.

      * Decoding data from a corrupted file with a dataset encoded with the
        H5Z_NBIT decoding can result in a code execution vulnerability under
        the context of the application using the HDF5 library.

      * When decoding an array datatype from a corrupted file, the HDF5 library
        fails to return an error in production if the number of dimensions
        decoded is greater than the maximum rank.

      * When decoding an "old style" array datatype from a corrupted file, the
        HDF5 library fails to return an error in production if the number of
        dimensions decoded is greater than the maximum rank.

      (NAF, 2016/10/06, HDFFV-9950, HDFFV-9951, HDFFV-9992, HDFFV-9993)

    - Fixed an error that would occur when copying an object with an attribute
      which is a compound datatype consisting of a variable length string.

      (VC, 2016/08/24, HDFFV-7991)

    - H5DOappend will no longer fail if a dataset has no append callback
      registered.

      (VC, 2016/08/14, HDFFV-9960)

    - Fixed an issue where H5Pset_alignment could result in misaligned blocks
      with some input combinations, causing an assertion failure in debug mode.

      (NAF, 2016/08/11, HDFFV-9948)

    - Fixed a problem where a plugin compiled into a DLL in the default plugin
      directory could not be found by the HDF5 library at runtime on Windows
      when the HDF5_PLUGIN_PATH environment variable was not set.

      (ABD, 2016/08/01, HDFFV-9706)

    - Fixed an error that would occur when calling H5Adelete on an attribute
      which is attached to an externally linked object in the target file and
      whose datatype is a committed datatype in the main file.

      (VC, 2016/07/06, HDFFV-9940)

    - (a) Throw an error instead of assertion when v1 btree level hits the 1
          byte limit.
      (b) Modifications to better handle error recovery when conversion by
          h5format_convert fails.

      (VC, 2016/05/29, HDFFV-9434)

    - Fixed a memory leak where an array used by the library to track SWMR
      read retries was unfreed.

      The leaked memory was small (on the order of a few tens of ints) and
      allocated per-file. The memory was allocated (and lost) only when a
      file was opened for SWMR access.

      (DER, 2016/04/27, HDFFV-9786)

    - Fixed a memory leak that could occur when opening a file for the first
      time (including creating) and the call fails.

      This occurred when the file-driver-specific info was not cleaned up.
      The amount of memory leaked varied with the file driver, but would
      normally be less than 1 kB.

      (DER, 2016/12/06, HDFFV-10168)

    - Fixed a failure in collective metadata writes.

      This failure only appeared when collective metadata writes
      were enabled (via H5Pset_coll_metadata_write()).

      (JRM, 2017/04/10, HDFFV-10055)


    Parallel Library
    ----------------
    - Fixed a bug that could occur when allocating a chunked dataset in parallel
      with an alignment set and an alignment threshold greater than the chunk
      size but less than or equal to the raw data aggregator size.

      (NAF, 2016/08/11, HDFFV-9969)


    Configuration
    -------------
    - Configuration will check for the strtoll and strtoull functions
      before using alternatives

      (ABD, 2017/03/17, PR#340)

    - CMake uses a Windows pdb directory variable if available and
      will generate both static and shared pdb files.

      (ABD, 2017/02/06, HDFFV-9875)

    - CMake now builds shared versions of tools.

      (ABD, 2017/02/01, HDFFV-10123)

    - Makefiles and test scripts have been updated to correctly remove files
      created when running "make check" and to avoid removing any files under
      source control.  In-source builds followed by "make clean" and "make
      distclean" should result in the original source files.
      (LRK, 2017/01/17, HDFFV-10099)

    - The tools directory has been divided into two separate source and test
      directories. This resolves a build dependency and, as a result,
      'make check' will no longer fail in the tools directory if 'make' was
      not executed first.

      (ABD, 2016/10/27, HDFFV-9719)

    - CMake: Fixed a timeout error that would occasionally occur when running
      the virtual file driver tests simultaneously due to test directory
      and file name collisions.

      (ABD, 2016/09/19, HDFFV-9431)

    - CMake: Fixed a command length overflow error by converting custom
      commands inside CMakeTest.cmake files into regular dependencies and
      targets.

      (ABD, 2016/07/12, HDFFV-9939)

    - Fixed a problem preventing HDF5 to be built on 32-bit CYGWIN by
      condensing cygwin configuration files into a single file and
      removing outdated compiler settings.

      (ABD, 2016/07/12, HDFFV-9946)


    Fortran
    --------
    - Changed H5S_ALL_F from INTEGER to INTEGER(HID_T)

      (MSB, 2016/10/14, HDFFV-9987)


    Tools
    -----
    - h5diff now correctly ignores strpad in comparing strings.

      (ABD, 2017/03/03, HDFFV-10128)

    - h5repack now correctly parses the command line filter options.

      (ABD, 2017/01/24, HDFFV-10046)

    - h5diff now correctly returns an error when it cannot read data due
      to an unavailable filter plugin.

      (ADB 2017/01/18, HDFFV-9994 )

    - Fixed an error in the compiler wrapper scripts (h5cc, h5fc, et al.)
      in which they would erroneously drop the file argument specified via
      the -o flag when the -o flag was specified before the -c flag on the
      command line, resulting in a failure to compile.

      (LRK, 2016/11/04, HDFFV-9938, HDFFV-9530)

    - h5repack User Defined (UD) filter parameters were not parsed correctly.

      The UD filter parameters were not being parsed correctly. Reworked coding
      section to parse the correct values and verify number of parameters.

      (ABD, 2016/10/19, HDFFV-9996, HDFFV-9974, HDFFV-9515, HDFFV-9039)

    - h5repack allows the --enable-error-stack option on the command line.

      (ADB, 2016/08/08, HDFFV-9775)


    C++ APIs
    --------
    - The member function H5Location::getNumObjs() is moved to
      class Group because the objects are in a group or a file only,
      and H5Object::getNumAttrs to H5Location to get the number of
      attributes at a given location.

      (BMR, 2017/03/17, PR#466)

    - Due to the change in the C API, the overloaded functions of
      PropList::setProperty now need const for some arguments.  They are
      planned for deprecation and are replaced by new versions with proper
      consts.

      (BMR, 2017/03/17, PR#344)

    - The high-level API Packet Table (PT) did not write data correctly when
      the datatype is a compound type that has string type as one of the
      members.  This problem started in 1.8.15, after the fix of HDFFV-9042
      was applied, which caused the Packet Table to use native type to access
      the data.  It should be up to the application to specify whether the
      buffer to be read into memory is in the machine's native architecture.
      Thus, the PT is fixed to not use native type but to make a copy of the
      user's provided datatype during creation or the packet table's datatype
      during opening.  If an application wishes to use native type to read the
      data, then the application will request that.  However, the Packet Table
      doesn't provide a way to specify memory datatype in this release.  This
      feature will be available in future releases.

      (BMR, 2016/10/27, HDFFV-9758)

    - The obsolete macros H5_NO_NAMESPACE and H5_NO_STD have been removed from
      the HDF5 C++ API library.

      (BMR, 2016/10/23, HDFFV-9532)

    - The problem where a user-defined function cannot access both, attribute
      and dataset, using only one argument is now fixed.

      (BMR, 2016/10/11, HDFFV-9920)

    - In-memory array information, ArrayType::rank and
      ArrayType::dimensions, were removed. This is an implementation
      detail and should not affect applications.

      (BMR, 2016/04/25, HDFFV-9725)


    Testing
    -------
    - Fixed a problem that caused tests using SWMR to occasionally fail when
      running "make check" using parallel make.

      (LRK, 2016/03/22, PR#338, PR#346, PR#358)


Supported Platforms
===================

    Linux 2.6.32-573.18.1.el6.ppc64 gcc (GCC) 4.4.7 20120313 (Red Hat 4.4.7-4)
    #1 SMP ppc64 GNU/Linux        g++ (GCC) 4.4.7 20120313 (Red Hat 4.4.7-4)
    (ostrich)                     GNU Fortran (GCC) 4.4.7 20120313
                                      (Red Hat 4.4.7-4)
                                  IBM XL C/C++ V13.1
                                  IBM XL Fortran V15.1

    Linux 3.10.0-327.10.1.el7     GNU C (gcc), Fortran (gfortran), C++ (g++)
    #1 SMP x86_64 GNU/Linux       compilers:
    (kituo/moohan)                  Version 4.8.5 20150623 (Red Hat 4.8.5-4)
                                    Version 4.9.3, Version 5.2.0
                                  Intel(R) C (icc), C++ (icpc), Fortran (icc)
                                  compilers:
                                     Version 15.0.3.187 Build 20150407
                                  MPICH 3.1.4 compiled with GCC 4.9.3

    SunOS 5.11 32- and 64-bit     Sun C 5.12 SunOS_sparc
    (emu)                         Sun Fortran 95 8.6 SunOS_sparc
                                  Sun C++ 5.12 SunOS_sparc

    Windows 7                     Visual Studio 2012 w/ Intel Fortran 15 (cmake)
                                  Visual Studio 2013 w/ Intel Fortran 15 (cmake)
                                  Visual Studio 2015 w/ Intel Fortran 16 (cmake)

    Windows 7 x64                 Visual Studio 2012 w/ Intel Fortran 15 (cmake)
                                  Visual Studio 2013 w/ Intel Fortran 15 (cmake)
                                  Visual Studio 2015 w/ Intel Fortran 16 (cmake)
                                  Visual Studio 2015 w/ MSMPI 8 (cmake)
                                  Cygwin(CYGWIN_NT-6.1 2.8.0(0.309/5/3)
                                      gcc and gfortran compilers (GCC 5.4.0)
                                      (cmake and autotools)

    Windows 10                    Visual Studio 2015 w/ Intel Fortran 16 (cmake)
                                  Cygwin(CYGWIN_NT-6.1 2.8.0(0.309/5/3)
                                      gcc and gfortran compilers (GCC 5.4.0)
                                      (cmake and autotools)

    Windows 10 x64                Visual Studio 2015 w/ Intel Fortran 16 (cmake)

    Mac OS X Mt. Lion 10.8.5      Apple clang/clang++ version 5.1 from Xcode 5.1
    64-bit                        gfortran GNU Fortran (GCC) 4.8.2
    (swallow/kite)                Intel icc/icpc/ifort version 15.0.3

    Mac OS X Mavericks 10.9.5     Apple clang/clang++ version 6.0 from Xcode 6.2
    64-bit                        gfortran GNU Fortran (GCC) 4.9.2
    (wren/quail)                  Intel icc/icpc/ifort version 15.0.3

    Mac OS X Yosemite 10.10.5     Apple clang/clang++ version 6.1 from Xcode 7.0
    64-bit                        gfortran GNU Fortran (GCC) 4.9.2
    (osx1010dev/osx1010test)      Intel icc/icpc/ifort version 15.0.3

    Mac OS X El Capitan 10.11.6   Apple clang/clang++ version 7.3 from Xcode 7.3
    64-bit                        gfortran GNU Fortran (GCC) 5.2.0
    (osx1010dev/osx1010test)      Intel icc/icpc/ifort version 16.0.2


Tested Configuration Features Summary
=====================================

    In the tables below
          y   = tested
          n   = not tested in this release
          C   = Cluster
          W   = Workstation
          x   = not working in this release
          dna = does not apply
          ( ) = footnote appears below second table
          <blank> = testing incomplete on this feature or platform

Platform                              C         F90/   F90      C++  zlib  SZIP
                                      parallel  F2003  parallel
Solaris2.11 32-bit                      n        y/y    n        y    y     y
Solaris2.11 64-bit                      n        y/n    n        y    y     y
Windows 7                               y        y/y    n        y    y     y
Windows 7 x64                           y        y/y    y        y    y     y
Windows 7 Cygwin                        n        y/n    n        y    y     y
Windows 7 x64 Cygwin                    n        y/n    n        y    y     y
Windows 10                              y        y/y    n        y    y     y
Windows 10 x64                          y        y/y    n        y    y     y
Mac OS X Mountain Lion 10.8.5 64-bit    n        y/y    n        y    y     y
Mac OS X Mavericks 10.9.5 64-bit        n        y/y    n        y    y     y
Mac OS X Yosemite 10.10.5 64-bit        n        y/y    n        y    y     y
Mac OS X El Capitan 10.11.6 64-bit      n        y/y    n        y    y     y
CentOS 7.2 Linux 2.6.32 x86_64 PGI      n        y/y    n        y    y     y
CentOS 7.2 Linux 2.6.32 x86_64 GNU      y        y/y    y        y    y     y
CentOS 7.2 Linux 2.6.32 x86_64 Intel    n        y/y    n        y    y     y
Linux 2.6.32-573.18.1.el6.ppc64         n        y/y    n        y    y     y


Platform                                 Shared  Shared    Shared    Thread-
                                         C libs  F90 libs  C++ libs  safe
Solaris2.11 32-bit                         y       y         y         y
Solaris2.11 64-bit                         y       y         y         y
Windows 7                                  y       y         y         y
Windows 7 x64                              y       y         y         y
Windows 7 Cygwin                           n       n         n         y
Windows 7 x64 Cygwin                       n       n         n         y
Windows 10                                 y       y         y         y
Windows 10 x64                             y       y         y         y
Mac OS X Mountain Lion 10.8.5 64-bit       y       n         y         y
Mac OS X Mavericks 10.9.5 64-bit           y       n         y         y
Mac OS X Yosemite 10.10.5 64-bit           y       n         y         y
Mac OS X El Capitan 10.11.6 64-bit         y       n         y         y
CentOS 7.2 Linux 2.6.32 x86_64 PGI         y       y         y         n
CentOS 7.2 Linux 2.6.32 x86_64 GNU         y       y         y         y
CentOS 7.2 Linux 2.6.32 x86_64 Intel       y       y         y         n
Linux 2.6.32-573.18.1.el6.ppc64            y       y         y         n

Compiler versions for each platform are listed in the preceding
"Supported Platforms" table.


More Tested Platforms
=====================

The following platforms are not supported but have been tested for this release.

    Linux 2.6.32-573.22.1.el6     GNU C (gcc), Fortran (gfortran), C++ (g++)
    #1 SMP x86_64 GNU/Linux       compilers:
    (mayll/platypus)                 Version 4.4.7 20120313
                                     Version 4.8.4
                                  PGI C, Fortran, C++ for 64-bit target on
                                  x86-64;
                                      Version 16.10-0
                                  Intel(R) C (icc), C++ (icpc), Fortran (icc)
                                  compilers:
                                     Version 15.0.3.187 (Build 20150407)
                                  MPICH 3.1.4 compiled with GCC 4.9.3

    Linux 3.10.0-327.18.2.el7     GNU C (gcc) and C++ (g++) compilers
    #1 SMP x86_64 GNU/Linux          Version 4.8.5 20150623 (Red Hat 4.8.5-4)
    (jelly)                       with NAG Fortran Compiler Release 6.1(Tozai)
                                  Intel(R) C (icc) and C++ (icpc) compilers
                                     Version 15.0.3.187 (Build 20150407)
                                  with NAG Fortran Compiler Release 6.1(Tozai)

    Linux 2.6.32-573.18.1.el6.ppc64  MPICH mpich 3.1.4 compiled with
    #1 SMP ppc64 GNU/Linux           IBM XL C/C++ for Linux, V13.1
    (ostrich)                        and IBM XL Fortran for Linux, V15.1

    Debian 8.4 3.16.0-4-amd64 #1 SMP Debian 3.16.36-1 x86_64 GNU/Linux
                                  gcc, g++ (Debian 4.9.2-10) 4.9.2
                                  GNU Fortran (Debian 4.9.2-10) 4.9.2
                                  (cmake and autotools)

    Fedora 24  4.7.2-201.fc24.x86_64 #1 SMP x86_64 x86_64 x86_64 GNU/Linux
                                  gcc, g++ (GCC) 6.1.1 20160621
                                      (Red Hat 6.1.1-3)
                                  GNU Fortran (GCC) 6.1.1 20160621
                                      (Red Hat 6.1.1-3)
                                  (cmake and autotools)

    Ubuntu 16.04.1 4.4.0-38-generic #57-Ubuntu SMP x86_64 GNU/Linux
                                  gcc, g++ (Ubuntu 5.4.0-6ubuntu1~16.04.2)
                                      5.4.0 20160609
                                  GNU Fortran (Ubuntu 5.4.0-6ubuntu1~16.04.2)
                                      5.4.0 20160609
                                  (cmake and autotools)


Known Problems
==============

    At present, metadata cache images may not be generated by parallel
    applications.  Parallel applications can read files with metadata cache
    images, but since this is a collective operation, a deadlock is possible
    if one or more processes do not participate.

    Known problems in previous releases can be found in the HISTORY*.txt files
    in the HDF5 source. Please report any new problems found to
    help@hdfgroup.org.


%%%%1.10.0-patch1%%%%


HDF5 version 1.10.0-patch1 released on 2016-05-23
================================================================================

INTRODUCTION

This document describes the differences between HDF5-1.8 series and
HDF5 1.10.0 releases, and contains information on the platforms
tested.

Links to HDF5 1.10.0 source code can be found on The HDF Group's
development FTP server at the following location:

    https://www.hdfgroup.org/HDF5/release/obtain5110.html

User documentation can be accessed directly at this location:

    https://www.hdfgroup.org/HDF5/docNewFeatures/

For more information, see the HDF5 home page:

    https://www.hdfgroup.org/HDF5/

If you have any questions or comments, please send them to the HDF
Help Desk:

    help@hdfgroup.org



CONTENTS

- New Features
- Issues Addressed in this Release
- Supported Platforms
- Tested Configuration Features Summary
- More Tested Platforms
- Known Problems and Limitations



New Features
============
This release supports the following features:

    Configuration
    -------------
    - API Compatibility with HDF5 1.8 Flag Was Added

      The 1.10 version of the HDF5 Library can be configured to operate
      identically to the 1.8 library with the --with-default-api-version=v18
      configure flag. This allows existing code to be compiled with the 1.10
      library without requiring immediate changes to the application source
      code. For additional configuration options and other details, see
      "API Compatibility Macros in HDF5" at
      https://www.hdfgroup.org/HDF5/doc/RM/APICompatMacros.html.

    - Autotools Configuration Has Been Extensively Reworked

      The autotools configuration options have been updated to allow more
      fine-grained control of the build options and to correct some bugs.
      See configure --help for comprehensive information on each option.

      Specific changes:

      * --enable-debug and --enable-production are no longer accepted.
        Use --enable-build-mode=(debug | production) instead. These set
        appropriate defaults for symbols, optimizations, and other
        configuration options. These defaults can be overridden by the
        user.

      * Extra debug output messages are no longer enabled with
        --enable-debug=<package list>. Use --enable-internal-debug=<pkg list>
        instead.

      * A new --enable-symbols option allows symbols to be generated
        independently of the build mode. --disable-symbols can be used
        to strip symbols from the binary.

      * A new --enable-asserts option sets/unsets NDEBUG. This is
        independent of the build mode. This also enables some extra
        low-overhead debug checks in the library.

      * A new --enable-profiling option sets profiling flags. This is
        independent of the build mode.

      * A new --enable-optimization option sets the optimization level.
        This is independent of the build mode.

      * Many of these options can take a flags string that will be used
        to build the library. This can be useful for specifying custom
        optimization flags such as -Os and -Ofast.

      * gnu C++ and Fortran use configure sub-files that update the
        build flags and turn on warnings. The increase in warnings when
        building these wrapper libraries is due to these flag changes
        and not to a decrease in code quality.

      * The option to clear file buffers has been removed. Any buffer that
        will eventually be written to disk will now always be memset
        to zero. This prevents the previous contents of the buffer from
        being written to the disk if the buffer contents are not
        completely overwritten, which has security implications.

    - LFS Changes

      The way the autotools handle large file support (LFS) has been
      overhauled in this release.

      * We assume ftello and fseeko exist

      * We no longer explicitly use the *64 I/O functions. Instead, we
        rely on a mapping provided by _FILE_OFFSET_BITS or its equivalent.

      * _LARGEFILE(64)_SOURCE is no longer exported via AM_CPPFLAGS.



    Parallel Library
    -----------------
    - Collective Metadata I/O

      Calls for HDF5 metadata can result in many small reads and writes.
      On metadata reads, collective metadata I/O can improve performance
      by allowing the library to perform optimizations when reading the
      metadata by having one rank read the data and broadcasting it to
      all other ranks.

      Collective metadata I/O improves metadata write performance through
      the construction of an MPI derived datatype that is then written
      collectively in a single call. For more information, see
      https://www.hdfgroup.org/HDF5/docNewFeatures/NewFeaturesCollectiveMetadataIoDocs.html.



    Library
    --------
    - Concurrent Access to HDF5 Files - Single Writer/ Multiple Reader (SWMR)

      The Single Writer/ Multiple Reader or SWMR feature enables users to
      read data concurrently while writing it. Communications between the
      processes and file locking are not required. The processes can run
      on the same or on different platforms as long as they share a common
      file system that is POSIX compliant. For more information, see the
      Single-Writer/Multiple-Reader (SWMR) documentation at
      https://www.hdfgroup.org/HDF5/docNewFeatures/NewFeaturesSwmrDocs.html.

    - Virtual Dataset (VDS)

      The VDS feature enables data to be accessed across HDF5 files
      using standard HDF5 objects such as groups and datasets without
      rewriting or rearranging the data. An HDF5 virtual dataset (VDS)
      is an HDF5 dataset that is composed of source HDF5 datasets in
      a predefined mapping. VDS can be used with the SWMR feature. For
      documentation, check
      https://www.hdfgroup.org/HDF5/docNewFeatures/NewFeaturesVirtualDatasetDocs.html.

    - Persistent Free File Space Tracking

      Usage patterns when working with an HDF5 file sometimes result in
      wasted space within the file. This can also impair access times
      when working with the resulting files. The new file space management
      feature provides strategies for managing space in a file to improve
      performance in both of these areas. For more information, see
      https://www.hdfgroup.org/HDF5/docNewFeatures/NewFeaturesFileSpaceMgmtDocs.html.

    - Version 3 Metadata Cache

      The version 3 metadata cache moves management of metadata I/O from
      the clients to the metadata cache proper.  This change is essential for
      SWMR and other features that have yet to be released.



    C++ Library
    ------------
    - New Member Function Added to H5::ArrayType

      The assignment operator ArrayType::operator= was added because
      ArrayType has pointer data members.

      (BMR - 2016/03/07, HDFFV-9562)



    Tools
    ------
    - h5watch

      The h5watch tool allows users to output new records appended to
      a dataset under SWMR access as it grows. The functionality is
      similar to the Unix user command "tail" with the follow option,
      which outputs appended data as the file grows. For more
      information, see
      https://www.hdfgroup.org/HDF5/docNewFeatures/NewFeaturesSwmrDocs.html#Tools.

    - h5format_convert

      The h5format_convert tool allows users to convert the indexing
      type of a chunked dataset made with a 1.10.x version of the HDF5
      Library when the latest file format is used to the 1.8.x version 1 B-tree indexing
      type. For example, datasets created using SWMR access, can be
      converted to be accessed by the HDF5 1.18 library and tools. The
      tool does not rewrite raw data, but it does rewrite HDF5 metadata.



    High-Level APIs
    ----------------
    - H5DOappend

      The function appends data to a dataset along a specified dimension.


    C Packet Table API
    ------------------
    - Replacement of a Public Function with H5PTcreate

      The existing function H5PTcreate_fl limits applications so they
      can use the deflate compression only. The public function
      H5PTcreate has been added to replace H5PTcreate_fl. H5PTcreate
      takes a property list identifier to provide flexibility on
      creation properties.

      (BMR - 2016/03/04, HDFFV-8623)

    - New Public Functions: H5PTget_dataset and H5PTget_type

      Two accessor functions have been added. H5PTget_dataset returns
      the identifier of the dataset associated with the packet table,
      and H5PTget_type returns the identifier of the datatype used by
      the packet table.

      (BMR, 2016/03/04, HDFFV-8623)

    - Regarding #ifdef VLPT_REMOVED

      The #ifdef VLPT_REMOVED blocks have been removed from the packet
      table (PT) library source except for the following functions:
        + H5PTis_varlen() has been made available again
        + H5PTfree_vlen_readbuff() is now H5PTfree_vlen_buff()

      (BMR - 2016/03/04, HDFFV-442)

    C++ Packet Table API
    --------------------
    - New Constructor Added to FL_PacketTable

      An overloaded constructor has been added to FL_PacketTable and
      takes a property list identifier to provide flexibility on
      creation properties.

      (BMR - 2016/03/08, HDFFV-8623)

    - New Public Functions

      Two accessor wrappers are added to class PacketTable.
      PacketTable::GetDataset() returns the identifier of the dataset
      associated with the packet table, and PacketTable::GetDatatype()
      returns the identifier of the datatype that the packet table uses.

      (BMR - 2016/03/04, HDFFV-8623)

    - Member Functions with "char*" as an Argument

      Overloaded functions were added to provide the "const char*"
      argument; the existing version will be deprecated in future
      releases.

      (BMR - 2016/03/04, HDFFV-8623)

    - Regarding #ifdef VLPT_REMOVED

      The #ifdef VLPT_REMOVED blocks have been removed from the packet
      table library source code except for the following functions:
        + VL_PacketTable::IsVariableLength() was moved to PacketTable
        + VL_PacketTable::FreeReadBuff() is now PacketTable::FreeBuff()

      (BMR - 2016/03/04, HDFFV-442)



    Java Wrapper Library
    --------------------

    The Java HDF5 JNI library has been integrated into the HDF5 repository.
    The configure option is "--enable-java", and the CMake option is
    HDF5_BUILD_JAVA:BOOL=ON. The package hierarchy has changed from the
    HDF5 1.8 JNI, which was "ncsa.hdf.hdflib.hdf5", to HDF5 1.10,
    "hdf.hdflib.hdf5".

    A number of new APIs were added including some for VDS and SWMR.



    Other Important Changes
    -----------------------

    The hid_t type was changed from 32-bit to a 64-bit value.



Issues Addressed in this Release Since 1.10.0
=============================================

     - h5diff would return from a compare attributes abnormally if one of the datatypes
       was a vlen. This resulted in a memory leak as well as an incorrect report of
       attribute comparison.

       Fixed.
       (ADB - 2016/04/26, HDFFV-9784)

     - The JUnit-interface test may fail on Solaris platforms. The result of
       a test for verifying the content of the error stack to stdout is
       in a different order on Solaris then other platforms.

       This test is skipped on Solaris
       (ADB - 2016/04/21, HDFFV-9734)

     - When building HDF5 with Java using CMake and specifying Debug for CMAKE_BUILD_TYPE,
       there was a missing command argument for the tests of the examples.

       Fixed.
       (ADB - 2016/04/21, HDFFV-9743)

     - Changed h5diff to print a warning when a dataset is virtual, enabling
       the data to be compared. In addition h5repack failed to copy the data
       of a virtual dataset to the new file. Function H5D__get_space_status changed
       to correctly determine the H5D_space_status_t allocation value.

       CMake added the Fixed Array indexing tests that were only in the autotools
       test scripts.

       Fixed and tests added for vds issues.
       (ADB,NAF - 2016/04/21, HDFFV-9756)

     - CMake added the h5format_convert tool and tests that were only in the autotools
       build and test scripts. The autotools test script was reworked to allow CMake
       to execute the test suite in parallel.

       Also, h5clear tool and tests were added to the misc folder.

       Fixed.
       (ADB - 2016/04/21, HDFFV-9766)

     - CMake added the h5watch tool and argument tests that were only in the autotools
       build and test scripts. The POSIX only tests were not added to CMake.

       CMake HL tools files were refactored to move the CMake test scripts into each tool folder.

       Fixed.
       (ADB - 2016/04/21, HDFFV-9770)

     - Configure fails to detect valid real KINDs on FreeBSD 9.3 (i386) with Fortran enabled.

       Fixed. Added the exponential option to SELECTED_REAL_KIND to distinguish
       KINDs of same precision
       (MSB - 2016/05/14,HDFFV-9912)


     - Corrected the f90 H5AWRITE_F integer interface's buf to be INTENT(IN).
       (MSB - 2016/05/14)

     - Configure fails in sed command on FreeBSD 9.3 (i386) with Fortran enabled.

       Fixed.
       (MSB - 2016/05/14,HDFFV-9912)

     - Compile time error in H5f90global.F90 with IBM XL Fortran 14.1.0.13 on BG/Q with Fortran
       enabled.

       Fixed.
       (MSB - 2016/05/16,HDFFV-9917)

     - A cmake build with Fortran enabled does not install module h5fortkit

       Fixed.
       (MSB - 2016/05/23,HDFFV-9923)


Issues Addressed in this Release Since alpha1
=============================================

     - H5Pget_virtual_printf_gap, H5Pget_virtual_view, H5Pget_efile_prefix

       The correct access property list settings from the
       H5Pget_virtual_printf_gap, H5Pget_virtual_view, and
       H5Pget_efile_prefix function calls could not be retrieved
       using H5Dget_access_plist().

       Fixed.

       (DER and NAF - 2016/03/14, HDFFV-9716)

     - h5dump

       When h5dump was provided with the name of a non-existing file or
       when optional arguments were the last option on the command line,
       h5dump would segfault.

       Fixed.

       (ADB 2016/02/28 HDFFV-9639, HDFFV-9684)

     - No Error Message for Corrupt Metadata

       The HDF5 Library did not propagate an error when it encountered
       corrupt metadata in an HDF5 file. The issue was fixed for a
       specific file provided by a user. If you still see the problem,
       please contact help@hdfgroup.org

       Fixed.

       (MC - 2016/02/18, HDFFV-9670)

     - Problem Reading Chunked Datasets with a String Datatype Larger
       Than the Chunk Size in Bytes

       When the latest file format was used and when a chunked dataset
       was created with a datatype with the size bigger than a chunk
       size, the data could not be read back. The issue was reported
       for chunked datasets with a string datatype and was confirmed
       for other datatypes with the sizes bigger than the chunk size in
       bytes.

       Fixed.

       (JM - 2016/02/13, HDFFV-9672)

     - Control over the Location of External Files

       Users were unable to specify the locations of external files.

       Two APIs - H5Pget_efile_prefix and H5Pset_efile_prefix - were
       added so that users could specify the locations of external files.

       (DER - 2016/02/04, HDFFV-8740)



Issues Addressed in this Release Since alpha0
=============================================
    - h5format_convert

      The h5format_convert tool did not downgrade the version of the
      superblock.

      Fixed. The tool now will downgrade the version of the superblock.

      (EIP 2016/01/11)

    - Crashes with multiple threads: invalid pointers

      It was reported that alpha0 crashed when used with multiple
      threads. The issue exists in the HDF5 Library versions 1.8 and
      1.9. The problem is related to a shared file pointer used in some
      miscellaneous data structures. The thread-safe library exposed
      paths in the library where a file pointer became invalid.

      The alpha1 release contains the fixes for the specific use case
      as described in HDFFV-9643. We will keep working on identifying
      and fixing other paths in the library with similar problems.

      (EIP - 2016/01/15, HDFFV-9643)



Supported Platforms
===================
The following platforms are supported and have been tested for this release.
They are built with the configure process unless specified otherwise.

    AIX 6.1                       xlc/xlc_r 10.1.0.5
    (NASA G-ADA)                  xlC/xlC_r 10.1.0.5
                                  xlf90/xlf90_r 12.1.0.6

    Linux 2.6.32-573.22.1.el6     GNU C (gcc), Fortran (gfortran), C++ (g++)
    #1 SMP x86_64 GNU/Linux       compilers:
    (mayll/platypus)                 Version 4.4.7 20120313 (Red Hat 4.4.7-16)
                                     Version 4.9.3, Version 5.2.0
                                  PGI C, Fortran, C++ for 64-bit target on
                                  x86-64;
                                      Version 15.7-0
                                  Intel(R) C (icc), C++ (icpc), Fortran (icc)
                                  compilers:
                                     Version 15.0.3.187 Build 20150407
                                  MPICH 3.1.4 compiled with GCC 4.9.3

    Linux 2.6.32-573.18.1.el6.ppc64 gcc (GCC) 4.4.7 20120313 (Red Hat 4.4.7-11)
    #1 SMP ppc64 GNU/Linux        g++ (GCC) 4.4.7 20120313 (Red Hat 4.4.7-11)
    (ostrich)                     GNU Fortran (GCC) 4.4.7 20120313 (Red Hat 4.4.7-11)
                                  IBM XL C/C++ V13.1
                                  IBM XL Fortran V15.1

    Linux 3.10.0-327.10.1.el7   GNU C (gcc), Fortran (gfortran), C++ (g++)
    #1 SMP x86_64 GNU/Linux       compilers:
    (kituo/moohan)                  Version 4.8.5 20150623 (Red Hat 4.8.5-4)
                                    Version 4.9.3, Version 5.2.0
                                  Intel(R) C (icc), C++ (icpc), Fortran (icc)
                                  compilers:
                                     Version 15.0.3.187 Build 20150407
                                  MPICH 3.1.4 compiled with GCC 4.9.3

    SunOS 5.11 32- and 64-bit     Sun C 5.12 SunOS_sparc
    (emu)                         Sun Fortran 95 8.6 SunOS_sparc
                                  Sun C++ 5.12 SunOS_sparc

    Windows 7                     Visual Studio 2012 w/ Intel Fortran 15 (cmake)
                                  Visual Studio 2013 w/ Intel Fortran 15 (cmake)
                                  Visual Studio 2015 w/ Intel Fortran 16 (cmake)
                                  Cygwin(CYGWIN_NT-6.1 2.2.1(0.289/5/3) gcc(4.9.3) compiler and gfortran)
                                  (cmake and autotools)

    Windows 7 x64                 Visual Studio 2012 w/ Intel Fortran 15 (cmake)
                                  Visual Studio 2013 w/ Intel Fortran 15 (cmake)
                                  Visual Studio 2015 w/ Intel Fortran 16 (cmake)

    Windows 8.1                   Visual Studio 2012 w/ Intel Fortran 15 (cmake)
                                  Visual Studio 2013 w/ Intel Fortran 15 (cmake)

    Windows 8.1 x64               Visual Studio 2012 w/ Intel Fortran 15 (cmake)
                                  Visual Studio 2013 w/ Intel Fortran 15 (cmake)

    Mac OS X Mt. Lion 10.8.5      Apple clang/clang++ version 5.1 from Xcode 5.1
    64-bit                        gfortran GNU Fortran (GCC) 4.8.2
    (swallow/kite)                Intel icc/icpc/ifort version 15.0.3

    Mac OS X Mavericks 10.9.5     Apple clang/clang++ version 6.0 from Xcode 6.2
    64-bit                        gfortran GNU Fortran (GCC) 4.9.2
    (wren/quail)                  Intel icc/icpc/ifort version 15.0.3

    Mac OS X Yosemite 10.10.5     Apple clang/clang++ version 6.0 from Xcode 7.0
    64-bit                        gfortran GNU Fortran (GCC) 4.9.2
    (osx1010dev/osx1010test)      Intel icc/icpc/ifort version 15.0.3

    Mac OS X El Capitan 10.11.4   Apple clang/clang++ version 7.3.0 from Xcode 7.3
    64-bit                        gfortran GNU Fortran (GCC) 5.2.0
    (osx1010dev/osx1010test)      Intel icc/icpc/ifort version 15.0.3



Tested Configuration Features Summary
=====================================

    In the tables below
          y   = tested
          n   = not tested in this release
          C   = Cluster
          W   = Workstation
          x   = not working in this release
          dna = does not apply
          ( ) = footnote appears below second table
          <blank> = testing incomplete on this feature or platform

Platform                              C         F90/   F90      C++  zlib  SZIP
                                      parallel  F2003  parallel
SunOS 5.11 32-bit                       n        y/y    n        y    y     y
SunOS 5.11 64-bit                       n        y/y    n        y    y     y
Windows 7                               y        y/y    n        y    y     y
Windows 7 x64                           y        y/y    n        y    y     y
Windows 7 Cygwin                        n        y/y    n        y    y     n
Windows 8.1                             n        y/y    n        y    y     y
Windows 8.1 x64                         n        y/y    n        y    y     y
Mac OS X Mountain Lion 10.8.5 64-bit    n        y/y    n        y    y     y
Mac OS X Mavericks 10.9.5 64-bit        n        y/y    n        y    y     y
Mac OS X Yosemeti 10.10.5 64-bit        n        y/y    n        y    y     y
AIX 6.1 32- and 64-bit                  n        y/n    n        y    y     y
CentOS 6.7 Linux 2.6.32 x86_64 GNU      y        y/y    y        y    y     y
CentOS 6.7 Linux 2.6.32 x86_64 Intel    n        y/y    n        y    y     y
CentOS 6.7 Linux 2.6.32 x86_64 PGI      n        y/y    n        y    y     y
CentOS 7.1 Linux 3.10.0 x86_64 GNU      y        y/y    y        y    y     y
CentOS 7.1 Linux 3.10.0 x86_64 Intel    n        y/y    n        y    y     y
Linux 2.6.32-431.11.2.el6.ppc64         n        y/n    n        y    y     y

Platform                                 Shared  Shared    Shared    Thread-
                                         C libs  F90 libs  C++ libs  safe
SunOS 5.11 32-bit                          y       y         y         y
SunOS 5.11 64-bit                          y       y         y         y
Windows 7                                  y       y         y         y
Windows 7 x64                              y       y         y         y
Windows 7 Cygwin                           n       n         n         y
Windows 8.1                                y       y         y         y
Windows 8.1 x64                            y       y         y         y
Mac OS X Mountain Lion 10.8.5 64-bit       y       n         y         y
Mac OS X Mavericks 10.9.5 64-bit           y       n         y         y
Mac OS X Yosemeti 10.10.5 64-bit           y       n         y         y
AIX 6.1 32- and 64-bit                     y       n         n         y
CentOS 6.7 Linux 2.6.32 x86_64 GNU         y       y         y         y
CentOS 6.7 Linux 2.6.32 x86_64 Intel       y       y         y         y
CentOS 6.7 Linux 2.6.32 x86_64 PGI         y       y         y         y
CentOS 7.1 Linux 3.10.0 x86_64 GNU         y       y         y         y
CentOS 7.1 Linux 3.10.0 x86_64 Intel       y       y         y         y
Linux 2.6.32-431.11.2.el6.ppc64            y       y         y         y

Compiler versions for each platform are listed in the preceding
"Supported Platforms" table.



More Tested Platforms
=====================
The following platforms are not supported but have been tested for this release.

    Linux 2.6.18-431.11.2.el6     g95 (GCC 4.0.3 (g95 0.94!)
    #1 SMP x86_64 GNU/Linux
    (platypus)

    Windows 7                     Visual Studio 2008  (cmake)

    Windows 7 x64                 Visual Studio 2008  (cmake)

    Windows 7 x64                 Visual Studio 2010  (cmake) with SWMR using GPFS

    Windows 10                    Visual Studio 2013 w/ Intel Fortran 15 (cmake)

    Windows 10 x64                Visual Studio 2013 w/ Intel Fortran 15 (cmake)

    Debian7.5.0 3.2.0-4-amd64 #1 SMP Debian 3.2.51-1 x86_64 GNU/Linux
                                  gcc (Debian 4.7.2-5) 4.7.2
                                  GNU Fortran (Debian 4.7.2-5) 4.7.2
                                  (cmake and autotools)

    Fedora20 3.15.3-200.fc20.x86_64 #1 SMP x86_64 x86_64 x86_64 GNU/Linux
                                  gcc (GCC) 4.8.3 20140624 (Red Hat 4.8.3-1)
                                  GNU Fortran (GCC) 4.8.3 20140624 (Red Hat 4.8.3-1)
                                  (cmake and autotools)

    SUSE 13.1 3.11.10-17-desktop #1 SMP PREEMPT x86_64 x86_64 x86_64 GNU/Linux
                                  gcc (SUSE Linux) 4.8.1
                                  GNU Fortran (SUSE Linux) 4.8.1
                                  (cmake and autotools)

    Ubuntu 14.04 3.13.0-35-generic #62-Ubuntu SMP x86_64 GNU/Linux
                                  gcc (Ubuntu/Linaro 4.9.1-0ubuntu1) 4.9.1
                                  GNU Fortran (Ubuntu/Linaro 4.9.1-0ubuntu1) 4.9.1
                                  (cmake and autotools)

    hopper.nersc.gov              PrgEnv-gnu/5.2.40
                                  gcc (GCC) 4.9.2 20141030 (Cray Inc.)
                                  GNU Fortran (GCC) 4.9.2 20141030 (Cray Inc.)
                                  g++ (GCC) 4.9.2 20141030 (Cray Inc.)



Known Problems and Limitations
==============================
This section contains the list of known problems and limitations introduced
in this release of HDF5.

Note: this list is not exhaustive of all known issues discovered in HDF5
software to date. For a list of significant problems and known workarounds
identified in past releases, please refer to:

https://www.hdfgroup.org/HDF5/release/known_problems/

The HDF Group also maintains a JIRA issue-tracking database which is used to
capture all known issues which are too numerous to reasonably list in this
document. The HDF Group is taking steps to make our JIRA issue database
open to the public, and this section will refer to that database in a future
release. In the meantime, please contact help@hdfgroup.org if you come across
an issue not listed here or at the link above, and we will provide any
information about known workarounds that we have or add it to our list of
known issues if it is a new issue.

 - The flush/refresh test occasionally fails on OS X platforms. This is
   being investigated but no fix or workaround is available at this time.
   (DER - 2016/03/22, HDFFV-9731)

 - The VDS/SWMR test will fail with a segmentation fault if the library
   is built with --enable-using-memchecker. The is due to a VDS shutdown
   procedure freeing a shared resource too early when the memory
   checker changes are built. This problem does not arise when the
   memory checker changes are not used since the internal library free
   lists behave differently. The memory checker configure option should
   normally only be used under special circumstances so this should not
   affect most users. Users should be aware that the --enable-using-memchecker
   + VDS combination may cause a segfault, however, so Valgrind et al. may
   have to be used with an HDF5 library built without the feature if this
   proves to be a problem.
   (DER - 2016/03/21, HDFFV-9732)

 - SWMR feature limitations
   The SWMR feature will only work if an HDF5 file under SWMR access resides
   on a file system that obeys POSIX write() ordering semantics. Because of
   this, SWMR will not work on  network file systems such as NFS or SMB/Windows
   file shares since those systems do not guarantee write odering. SWMR
   regression tests are likely to fail if run on a network file system. SWMR
   is currently not tested on Windows though it can be tested manually
   (some of the SWMR test programs are built by CMake), and there are no
   obvious reasons for it to not work on NTFS or GPFS.
   (EIP - 2016/03/20, HDFFV-9733)

 - VDS feature limitation
   Currently, the path to a VDS source file is interpreted as relative to the
   directory where the executable program runs and not to the HDF5 file with
   the VDS dataset unless a full path to the source file is specified during
   the mapping.
   (EIP - 2016/03/20, HDFFV-9724)

 - The H5Lexists API changed behavior in HDF5-1.10 when used with a file handle
   and root group name ("/"):

   H5Lexists(fileid, "/")

   In HDF5-1.8 it returns false (0) and in HDF5-1.10 it returns true (1).
   The documentation will be updated with information regarding this change.
   (LRK - 2016/03/30, HDFFV-8746)


%%%%1.10.0%%%%

HDF5 version 1.10.0 released on 2016-03-30
================================================================================



INTRODUCTION

This document describes the differences between HDF5-1.8 series and
HDF5 1.10.0 releases, and contains information on the platforms
tested.

Links to HDF5 1.10.0 source code can be found on The HDF Group's
development FTP server at the following location:

    https://www.hdfgroup.org/HDF5/release/obtain5110.html

User documentation can be accessed directly at this location:

    https://www.hdfgroup.org/HDF5/docNewFeatures/

For more information, see the HDF5 home page:

    https://www.hdfgroup.org/HDF5/

If you have any questions or comments, please send them to the HDF
Help Desk:

    help@hdfgroup.org



CONTENTS

- New Features
- Issues Addressed in this Release
- Supported Platforms
- Tested Configuration Features Summary
- More Tested Platforms
- Known Problems and Limitations



New Features
============
This release supports the following features:

    Configuration
    -------------
    - API Compatibility with HDF5 1.8 Flag Was Added

      The 1.10 version of the HDF5 Library can be configured to operate
      identically to the 1.8 library with the --with-default-api-version=v18
      configure flag. This allows existing code to be compiled with the 1.10
      library without requiring immediate changes to the application source
      code. For additional configuration options and other details, see
      "API Compatibility Macros in HDF5" at
      https://www.hdfgroup.org/HDF5/doc/RM/APICompatMacros.html.

    - Autotools Configuration Has Been Extensively Reworked

      The autotools configuration options have been updated to allow more
      fine-grained control of the build options and to correct some bugs.
      See configure --help for comprehensive information on each option.

      Specific changes:

      * --enable-debug and --enable-production are no longer accepted.
        Use --enable-build-mode=(debug | production) instead. These set
        appropriate defaults for symbols, optimizations, and other
        configuration options. These defaults can be overridden by the
        user.

      * Extra debug output messages are no longer enabled with
        --enable-debug=<package list>. Use --enable-internal-debug=<pkg list>
        instead.

      * A new --enable-symbols option allows symbols to be generated
        independently of the build mode. --disable-symbols can be used
        to strip symbols from the binary.

      * A new --enable-asserts option sets/unsets NDEBUG. This is
        independent of the build mode. This also enables some extra
        low-overhead debug checks in the library.

      * A new --enable-profiling option sets profiling flags. This is
        independent of the build mode.

      * A new --enable-optimization option sets the optimization level.
        This is independent of the build mode.

      * Many of these options can take a flags string that will be used
        to build the library. This can be useful for specifying custom
        optimization flags such as -Os and -Ofast.

      * gnu C++ and Fortran use configure sub-files that update the
        build flags and turn on warnings. The increase in warnings when
        building these wrapper libraries is due to these flag changes
        and not to a decrease in code quality.

      * The option to clear file buffers has been removed. Any buffer that
        will eventually be written to disk will now always be memset
        to zero. This prevents the previous contents of the buffer from
        being written to the disk if the buffer contents are not
        completely overwritten, which has security implications.

    - LFS Changes

      The way the autotools handle large file support (LFS) has been
      overhauled in this release.

      * We assume ftello and fseeko exist

      * We no longer explicitly use the *64 I/O functions. Instead, we
        rely on a mapping provided by _FILE_OFFSET_BITS or its equivalent.

      * _LARGEFILE(64)_SOURCE is no longer exported via AM_CPPFLAGS.



    Parallel Library
    -----------------
    - Collective Metadata I/O

      Calls for HDF5 metadata can result in many small reads and writes.
      On metadata reads, collective metadata I/O can improve performance
      by allowing the library to perform optimizations when reading the
      metadata by having one rank read the data and broadcasting it to
      all other ranks.

      Collective metadata I/O improves metadata write performance through
      the construction of an MPI derived datatype that is then written
      collectively in a single call. For more information, see
      https://www.hdfgroup.org/HDF5/docNewFeatures/NewFeaturesCollectiveMetadataIoDocs.html.



    Library
    --------
    - Concurrent Access to HDF5 Files - Single Writer/ Multiple Reader (SWMR)

      The Single Writer/ Multiple Reader or SWMR feature enables users to
      read data concurrently while writing it. Communications between the
      processes and file locking are not required. The processes can run
      on the same or on different platforms as long as they share a common
      file system that is POSIX compliant. For more information, see the
      Single-Writer/Multiple-Reader (SWMR) documentation at
      https://www.hdfgroup.org/HDF5/docNewFeatures/NewFeaturesSwmrDocs.html.

    - Virtual Dataset (VDS)

      The VDS feature enables data to be accessed across HDF5 files
      using standard HDF5 objects such as groups and datasets without
      rewriting or rearranging the data. An HDF5 virtual dataset (VDS)
      is an HDF5 dataset that is composed of source HDF5 datasets in
      a predefined mapping. VDS can be used with the SWMR feature. For
      documentation, check
      https://www.hdfgroup.org/HDF5/docNewFeatures/NewFeaturesVirtualDatasetDocs.html.

    - Persistent Free File Space Tracking

      Usage patterns when working with an HDF5 file sometimes result in
      wasted space within the file. This can also impair access times
      when working with the resulting files. The new file space management
      feature provides strategies for managing space in a file to improve
      performance in both of these areas. For more information, see
      https://www.hdfgroup.org/HDF5/docNewFeatures/NewFeaturesFileSpaceMgmtDocs.html.

    - Version 3 Metadata Cache

      The version 3 metadata cache moves management of metadata I/O from
      the clients to the metadata cache proper.  This change is essential for
      SWMR and other features that have yet to be released.



    C++ Library
    ------------
    - New Member Function Added to H5::ArrayType

      The assignment operator ArrayType::operator= was added because
      ArrayType has pointer data members.

      (BMR - 2016/03/07, HDFFV-9562)



    Tools
    ------
    - h5watch

      The h5watch tool allows users to output new records appended to
      a dataset under SWMR access as it grows. The functionality is
      similar to the Unix user command "tail" with the follow option,
      which outputs appended data as the file grows. For more
      information, see
      https://www.hdfgroup.org/HDF5/docNewFeatures/NewFeaturesSwmrDocs.html#Tools.

    - h5format_convert

      The h5format_convert tool allows users to convert the indexing
      type of a chunked dataset made with a 1.10.x version of the HDF5
      Library when the latest file format is used to the 1.8.x version 1 B-tree indexing
      type. For example, datasets created using SWMR access, can be
      converted to be accessed by the HDF5 1.18 library and tools. The
      tool does not rewrite raw data, but it does rewrite HDF5 metadata.



    High-Level APIs
    ----------------
    - H5DOappend

      The function appends data to a dataset along a specified dimension.


    C Packet Table API
    ------------------
    - Replacement of a Public Function with H5PTcreate

      The existing function H5PTcreate_fl limits applications so they
      can use the deflate compression only. The public function
      H5PTcreate has been added to replace H5PTcreate_fl. H5PTcreate
      takes a property list identifier to provide flexibility on
      creation properties.

      (BMR - 2016/03/04, HDFFV-8623)

    - New Public Functions: H5PTget_dataset and H5PTget_type

      Two accessor functions have been added. H5PTget_dataset returns
      the identifier of the dataset associated with the packet table,
      and H5PTget_type returns the identifier of the datatype used by
      the packet table.

      (BMR, 2016/03/04, HDFFV-8623)

    - Regarding #ifdef VLPT_REMOVED

      The #ifdef VLPT_REMOVED blocks have been removed from the packet
      table (PT) library source except for the following functions:
        + H5PTis_varlen() has been made available again
        + H5PTfree_vlen_readbuff() is now H5PTfree_vlen_buff()

      (BMR - 2016/03/04, HDFFV-442)

    C++ Packet Table API
    --------------------
    - New Constructor Added to FL_PacketTable

      An overloaded constructor has been added to FL_PacketTable and
      takes a property list identifier to provide flexibility on
      creation properties.

      (BMR - 2016/03/08, HDFFV-8623)

    - New Public Functions

      Two accessor wrappers are added to class PacketTable.
      PacketTable::GetDataset() returns the identifier of the dataset
      associated with the packet table, and PacketTable::GetDatatype()
      returns the identifier of the datatype that the packet table uses.

      (BMR - 2016/03/04, HDFFV-8623)

    - Member Functions with "char*" as an Argument

      Overloaded functions were added to provide the "const char*"
      argument; the existing version will be deprecated in future
      releases.

      (BMR - 2016/03/04, HDFFV-8623)

    - Regarding #ifdef VLPT_REMOVED

      The #ifdef VLPT_REMOVED blocks have been removed from the packet
      table library source code except for the following functions:
        + VL_PacketTable::IsVariableLength() was moved to PacketTable
        + VL_PacketTable::FreeReadBuff() is now PacketTable::FreeBuff()

      (BMR - 2016/03/04, HDFFV-442)



    Java Wrapper Library
    --------------------

    The Java HDF5 JNI library has been integrated into the HDF5 repository.
    The configure option is "--enable-java", and the CMake option is
    HDF5_BUILD_JAVA:BOOL=ON. The package hierarchy has changed from the
    HDF5 1.8 JNI, which was "ncsa.hdf.hdflib.hdf5", to HDF5 1.10,
    "hdf.hdflib.hdf5".

    A number of new APIs were added including some for VDS and SWMR.



    Other Important Changes
    -----------------------

    The hid_t type was changed from 32-bit to a 64-bit value.



Issues Addressed in this Release Since alpha1
=============================================

     - H5Pget_virtual_printf_gap, H5Pget_virtual_view, H5Pget_efile_prefix

       The correct access property list settings from the
       H5Pget_virtual_printf_gap, H5Pget_virtual_view, and
       H5Pget_efile_prefix function calls could not be retrieved
       using H5Dget_access_plist().

       Fixed.

       (DER and NAF - 2016/03/14, HDFFV-9716)

     - h5dump

       When h5dump was provided with the name of a non-existing file or
       when optional arguments were the last option on the command line,
       h5dump would segfault.

       Fixed.

       (ADB 2016/02/28 HDFFV-9639, HDFFV-9684)

     - No Error Message for Corrupt Metadata

       The HDF5 Library did not propagate an error when it encountered
       corrupt metadata in an HDF5 file. The issue was fixed for a
       specific file provided by a user. If you still see the problem,
       please contact help@hdfgroup.org

       Fixed.

       (MC - 2016/02/18, HDFFV-9670)

     - Problem Reading Chunked Datasets with a String Datatype Larger
       Than the Chunk Size in Bytes

       When the latest file format was used and when a chunked dataset
       was created with a datatype with the size bigger than a chunk
       size, the data could not be read back. The issue was reported
       for chunked datasets with a string datatype and was confirmed
       for other datatypes with the sizes bigger than the chunk size in
       bytes.

       Fixed.

       (JM - 2016/02/13, HDFFV-9672)

     - Control over the Location of External Files

       Users were unable to specify the locations of external files.

       Two APIs - H5Pget_efile_prefix and H5Pset_efile_prefix - were
       added so that users could specify the locations of external files.

       (DER - 2016/02/04, HDFFV-8740)



Issues Addressed in this Release Since alpha0
=============================================
    - h5format_convert

      The h5format_convert tool did not downgrade the version of the
      superblock.

      Fixed. The tool now will downgrade the version of the superblock.

      (EIP 2016/01/11)

    - Crashes with multiple threads: invalid pointers

      It was reported that alpha0 crashed when used with multiple
      threads. The issue exists in the HDF5 Library versions 1.8 and
      1.9. The problem is related to a shared file pointer used in some
      miscellaneous data structures. The thread-safe library exposed
      paths in the library where a file pointer became invalid.

      The alpha1 release contains the fixes for the specific use case
      as described in HDFFV-9643. We will keep working on identifying
      and fixing other paths in the library with similar problems.

      (EIP - 2016/01/15, HDFFV-9643)



Supported Platforms
===================
The following platforms are supported and have been tested for this release.
They are built with the configure process unless specified otherwise.

    AIX 6.1                       xlc/xlc_r 10.1.0.5
    (NASA G-ADA)                  xlC/xlC_r 10.1.0.5
                                  xlf90/xlf90_r 12.1.0.6

    Linux 2.6.32-573.18.1.el6    GNU C (gcc), Fortran (gfortran), C++ (g++)
    #1 SMP x86_64 GNU/Linux       compilers:
    (mayll/platypus)                 Version 4.4.7 20120313 (Red Hat 4.4.7-16)
                                     Version 4.9.3, Version 5.2.0
                                  PGI C, Fortran, C++ for 64-bit target on
                                  x86-64;
                                      Version 15.7-0
                                  Intel(R) C (icc), C++ (icpc), Fortran (icc)
                                  compilers:
                                     Version 15.0.3.187 Build 20150407
                                  MPICH 3.1.4 compiled with GCC 4.9.3

    Linux 2.6.32-504.8.1.el6.ppc64 gcc (GCC) 4.4.7 20120313 (Red Hat 4.4.7-11)
    #1 SMP ppc64 GNU/Linux        g++ (GCC) 4.4.7 20120313 (Red Hat 4.4.7-11)
    (ostrich)                     GNU Fortran (GCC) 4.4.7 20120313 (Red Hat 4.4.7-11)
                                  IBM XL C/C++ V13.1
                                  IBM XL Fortran V15.1

    Linux 3.10.0-327.10.1.el7   GNU C (gcc), Fortran (gfortran), C++ (g++)
    #1 SMP x86_64 GNU/Linux       compilers:
    (kituo/moohan)                  Version 4.8.5 20150623 (Red Hat 4.8.5-4)
                                    Version 4.9.3, Version 5.2.0
                                  Intel(R) C (icc), C++ (icpc), Fortran (icc)
                                  compilers:
                                     Version 15.0.3.187 Build 20150407
                                  MPICH 3.1.4 compiled with GCC 4.9.3

    SunOS 5.11 32- and 64-bit     Sun C 5.12 SunOS_sparc
    (emu)                         Sun Fortran 95 8.6 SunOS_sparc
                                  Sun C++ 5.12 SunOS_sparc

    Windows 7                     Visual Studio 2012 w/ Intel Fortran 15 (cmake)
                                  Visual Studio 2013 w/ Intel Fortran 15 (cmake)
                                  Visual Studio 2015 w/ Intel Fortran 16 (cmake)
                                  Cygwin(CYGWIN_NT-6.1 2.2.1(0.289/5/3) gcc(4.9.3) compiler and gfortran)
                                  (cmake and autotools)

    Windows 7 x64                 Visual Studio 2012 w/ Intel Fortran 15 (cmake)
                                  Visual Studio 2013 w/ Intel Fortran 15 (cmake)
                                  Visual Studio 2015 w/ Intel Fortran 16 (cmake)

    Windows 8.1                   Visual Studio 2012 w/ Intel Fortran 15 (cmake)
                                  Visual Studio 2013 w/ Intel Fortran 15 (cmake)

    Windows 8.1 x64               Visual Studio 2012 w/ Intel Fortran 15 (cmake)
                                  Visual Studio 2013 w/ Intel Fortran 15 (cmake)

    Mac OS X Mt. Lion 10.8.5      Apple clang/clang++ version 5.1 from Xcode 5.1
    64-bit                  gfortran GNU Fortran (GCC) 4.8.2
    (swallow/kite)                Intel icc/icpc/ifort version 15.0.3

    Mac OS X Mavericks 10.9.5     Apple clang/clang++ version 6.0 from Xcode 6.2.0
    64-bit                  gfortran GNU Fortran (GCC) 4.9.2
    (wren/quail)                  Intel icc/icpc/ifort version 15.0.3

    Mac OS X Yosemite 10.10.5     Apple clang/clang++ version 6.0 from Xcode 7.0.0
    64-bit                  gfortran GNU Fortran (GCC) 4.9.2
    (osx1010dev/osx1010test)      Intel icc/icpc/ifort version 15.0.3

    Mac OS X El Capitan 10.11.3     Apple clang/clang++ version 7.0.2 from Xcode 7.0.2
    64-bit                  gfortran GNU Fortran (GCC) 5.2.0
    (osx1010dev/osx1010test)      Intel icc/icpc/ifort version 15.0.3



Tested Configuration Features Summary
=====================================

    In the tables below
          y   = tested
          n   = not tested in this release
          C   = Cluster
          W   = Workstation
          x   = not working in this release
          dna = does not apply
          ( ) = footnote appears below second table
          <blank> = testing incomplete on this feature or platform

Platform                              C         F90/   F90      C++  zlib  SZIP
                                      parallel  F2003  parallel
SunOS 5.11 32-bit                       n        y/y    n        y    y     y
SunOS 5.11 64-bit                       n        y/y    n        y    y     y
Windows 7                               y        y/y    n        y    y     y
Windows 7 x64                           y        y/y    n        y    y     y
Windows 7 Cygwin                        n        y/y    n        y    y     n
Windows 8.1                             n        y/y    n        y    y     y
Windows 8.1 x64                         n        y/y    n        y    y     y
Mac OS X Mountain Lion 10.8.5 64-bit    n        y/y    n        y    y     y
Mac OS X Mavericks 10.9.5 64-bit        n        y/y    n        y    y     y
Mac OS X Yosemeti 10.10.5 64-bit        n        y/y    n        y    y     y
AIX 6.1 32- and 64-bit                  n        y/n    n        y    y     y
CentOS 6.7 Linux 2.6.32 x86_64 GNU      y        y/y    y        y    y     y
CentOS 6.7 Linux 2.6.32 x86_64 Intel    n        y/y    n        y    y     y
CentOS 6.7 Linux 2.6.32 x86_64 PGI      n        y/y    n        y    y     y
CentOS 7.1 Linux 3.10.0 x86_64 GNU      y        y/y    y        y    y     y
CentOS 7.1 Linux 3.10.0 x86_64 Intel    n        y/y    n        y    y     y
Linux 2.6.32-431.11.2.el6.ppc64         n        y/n    n        y    y     y

Platform                                 Shared  Shared    Shared    Thread-
                                         C libs  F90 libs  C++ libs  safe
SunOS 5.11 32-bit                          y       y         y         y
SunOS 5.11 64-bit                          y       y         y         y
Windows 7                                  y       y         y         y
Windows 7 x64                              y       y         y         y
Windows 7 Cygwin                           n       n         n         y
Windows 8.1                                y       y         y         y
Windows 8.1 x64                            y       y         y         y
Mac OS X Mountain Lion 10.8.5 64-bit       y       n         y         y
Mac OS X Mavericks 10.9.5 64-bit           y       n         y         y
Mac OS X Yosemeti 10.10.5 64-bit           y       n         y         y
AIX 6.1 32- and 64-bit                     y       n         n         y
CentOS 6.7 Linux 2.6.32 x86_64 GNU         y       y         y         y
CentOS 6.7 Linux 2.6.32 x86_64 Intel       y       y         y         y
CentOS 6.7 Linux 2.6.32 x86_64 PGI         y       y         y         y
CentOS 7.1 Linux 3.10.0 x86_64 GNU         y       y         y         y
CentOS 7.1 Linux 3.10.0 x86_64 Intel       y       y         y         y
Linux 2.6.32-431.11.2.el6.ppc64            y       y         y         y

Compiler versions for each platform are listed in the preceding
"Supported Platforms" table.



More Tested Platforms
=====================
The following platforms are not supported but have been tested for this release.

    Linux 2.6.18-431.11.2.el6     g95 (GCC 4.0.3 (g95 0.94!)
    #1 SMP x86_64 GNU/Linux
    (platypus)

    Windows 7                     Visual Studio 2008  (cmake)

    Windows 7 x64                 Visual Studio 2008  (cmake)

    Windows 7 x64                 Visual Studio 2010  (cmake) with SWMR using GPFS

    Windows 10                    Visual Studio 2013 w/ Intel Fortran 15 (cmake)

    Windows 10 x64                Visual Studio 2013 w/ Intel Fortran 15 (cmake)

    Debian7.5.0 3.2.0-4-amd64 #1 SMP Debian 3.2.51-1 x86_64 GNU/Linux
                                  gcc (Debian 4.7.2-5) 4.7.2
                                  GNU Fortran (Debian 4.7.2-5) 4.7.2
                                  (cmake and autotools)

    Fedora20 3.15.3-200.fc20.x86_64 #1 SMP x86_64 x86_64 x86_64 GNU/Linux
                                  gcc (GCC) 4.8.3 20140624 (Red Hat 4.8.3-1)
                                  GNU Fortran (GCC) 4.8.3 20140624 (Red Hat 4.8.3-1)
                                  (cmake and autotools)

    SUSE 13.1 3.11.10-17-desktop #1 SMP PREEMPT x86_64 x86_64 x86_64 GNU/Linux
                                  gcc (SUSE Linux) 4.8.1
                                  GNU Fortran (SUSE Linux) 4.8.1
                                  (cmake and autotools)

    Ubuntu 14.04 3.13.0-35-generic #62-Ubuntu SMP x86_64 GNU/Linux
                                  gcc (Ubuntu/Linaro 4.9.1-0ubuntu1) 4.9.1
                                  GNU Fortran (Ubuntu/Linaro 4.9.1-0ubuntu1) 4.9.1
                                  (cmake and autotools)

    hopper.nersc.gov              PrgEnv-gnu/5.2.40
                                  gcc (GCC) 4.9.2 20141030 (Cray Inc.)
                                  GNU Fortran (GCC) 4.9.2 20141030 (Cray Inc.)
                                  g++ (GCC) 4.9.2 20141030 (Cray Inc.)



Known Problems and Limitations
==============================
This section contains the list of known problems and limitations introduced
in this release of HDF5.

Note: this list is not exhaustive of all known issues discovered in HDF5
software to date. For a list of significant problems and known workarounds
identified in past releases, please refer to:

https://www.hdfgroup.org/HDF5/release/known_problems/

The HDF Group also maintains a JIRA issue-tracking database which is used to
capture all known issues which are too numerous to reasonably list in this
document. The HDF Group is taking steps to make our JIRA issue database
open to the public, and this section will refer to that database in a future
release. In the meantime, please contact help@hdfgroup.org if you come across
an issue not listed here or at the link above, and we will provide any
information about known workarounds that we have or add it to our list of
known issues if it is a new issue.

 - The JUnit-interface test may fail on Solaris platforms. The result of
   a test for verifying the content of the error stack to stdout is
   in a different order on Solaris then other platforms. Use make -i option
   to test beyond the java/test folder.
   (ADB - 2016/03/22, HDFFV-9734)

 - The flush/refresh test occasionally fails on OS X platforms. This is
   being investigated but no fix or workaround is available at this time.
   (DER - 2016/03/22, HDFFV-9731)

 - The VDS/SWMR test will fail with a segmentation fault if the library
   is built with --enable-using-memchecker. The is due to a VDS shutdown
   procedure freeing a shared resource too early when the memory
   checker changes are built. This problem does not arise when the
   memory checker changes are not used since the internal library free
   lists behave differently. The memory checker configure option should
   normally only be used under special circumstances so this should not
   affect most users. Users should be aware that the --enable-using-memchecker
   + VDS combination may cause a segfault, however, so Valgrind et al. may
   have to be used with an HDF5 library built without the feature if this
   proves to be a problem.
   (DER - 2016/03/21, HDFFV-9732)

 - SWMR feature limitations
   The SWMR feature will only work if an HDF5 file under SWMR access resides
   on a file system that obeys POSIX write() ordering semantics. Because of
   this, SWMR will not work on  network file systems such as NFS or SMB/Windows
   file shares since those systems do not guarantee write odering. SWMR
   regression tests are likely to fail if run on a network file system. SWMR
   is currently not tested on Windows though it can be tested manually
   (some of the SWMR test programs are built by CMake), and there are no
   obvious reasons for it to not work on NTFS or GPFS.
   (EIP - 2016/03/20, HDFFV-9733)

 - VDS feature limitation
   Currently, the path to a VDS source file is interpreted as relative to the
   directory where the executable program runs and not to the HDF5 file with
   the VDS dataset unless a full path to the source file is specified during
   the mapping.
   (EIP - 2016/03/20, HDFFV-9724)

 - When building HDF5 with Java using CMake and specifying Debug for CMAKE_BUILD_TYPE,
   there is a missing command argument for the tests of the examples.

   This error can be avoided by not building Java with Debug, HDF5_BUILD_JAVA:BOOL=OFF,
   or not building Examples, HDF5_BUILD_EXAMPLES:BOOL=OFF.
   (LRK - 2016/03/30, HDFFV-9743)

 - The H5Lexists API changed behavior in HDF5-1.10 when used with a file handle
   and root group name ("/"):

   H5Lexists(fileid, "/")

   In HDF5-1.8 it returns false (0) and in HDF5-1.10 it returns true (1).
   The documentation will be updated with information regarding this change.
   (LRK - 2016/03/30, HDFFV-8746)