path: root/release_docs/RELEASE.txt

HDF5 version 1.5.48 currently under development
================================================================================


INTRODUCTION

This document describes the differences between HDF5-1.4.0 and
HDF5-1.5-snap0, and contains information on the platforms tested and
known problems in HDF5-1.5-snap0. For more details check the HISTORY.txt
file in the HDF5 source.

The HDF5 documentation can be found on the NCSA ftp server
(ftp.ncsa.uiuc.edu) in the directory:

     /HDF/HDF5/docs/

For more information look at the HDF5 home page at:
   
    http://hdf.ncsa.uiuc.edu/HDF5/

If you have any questions or comments, please send them to:

    hdfhelp@ncsa.uiuc.edu

CONTENTS

- New Features
- Bug Fixes since HDF5-1.4.0
- Support for new platforms and languages
- Platforms Tested
- Known Problems

Bug Fixes since HDF5-1.4.0
==========================

Library
-------
    * Corrected metadata caching bug in parallel I/O which could cause hangs
      when chunked datasets were accessed with independent transfer mode.
      QAK - 2003/02/10
    * Corrected memory/resource leaks in per-thread key information when
      thread-safe operation was enabled.  QAK - 2003/02/07
    * H5Fopen without the H5F_ACC_CREAT flag should not succeed in creating
      a new file with the 'core' VFL driver.  QAK - 2003/01/24
    * Allow opening objects with unknown object header messages.
      QAK - 2003/01/21
    * Improved error assertion for nil VL strings, making it fails with error
      stack instead of just assertion failure.  SLU - 2002/12/16
    * Added two new API functions: H5Zunregister & H5Zfilter_avail.
      QAK - 2002/11/16
    * Add data shuffle filter(source code H5Zshuffle.c), the combination of the
      shuffling and compression can make data compression better without suffering
      much encoding and decoding CPU time for many application datasets(especially
      for floating point data). This adds a new API function: H5Pset_shuffle.
      KY - 2002/11/13
    * Allow scalar dataspaces to be used for parallel I/O.  QAK - 2002/11/05
    * Fixed error condition where "none" selections were not being handled
      correctly in parallel.  QAK - 2002/10/29
    * New functions H5Gget_comment(modification), H5Aget_storage_size, 
      H5Arename.  SLU - 2002/10/29
    * Fixed an assertion of H5S_select_iterate that did not account for scalar
      type that has no dimension sizes.   AKC - 2002/10/15
    * Partially fixed space allocation inefficiencies in the file by
      improving our algorithms for re-using freed space.  QAK - 2002/08/27
    * Fixed data corruption problem which could occur when fill values were
      written to a contiguously stored dataset in parallel.  QAK - 2002/08/27
    * Fixed metadata corruption problem which could occur when many objects
      are created in a file during parallel I/O.  QAK - 2002/07/19
    * Fixed VL memory leak when data is overwritten.  The heap objects holding
      old data are freed.  If the fill value writting time is set to 
      H5D_FILL_TIME_NEVER, the library prohibits user to create VL type dataset.
      The library free all the heap objects storing VL type if there is nested 
      VL type(a VL type contains another VL type).  SLU - 2002/07/10 
    * Fixed bug in parallel I/O routines where a collective I/O which used
      MPI derived types, followed by an independent I/O would cause the library
      to hang.  QAK - 2002/06/24
    * Fixed bug in chunking routines where they were using internal allocation
      free routines, instead of malloc/free, preventing user filters from
      working correctly.  Chunks are now allocated/freed with malloc/free and
      so should the chunks in user filters.  QAK - 2002/06/18
    * Fixed bug where regular hyperslab selection could get incorrectly
      transferred when the number of elements in a row did not fit evenly
      into the buffer provided.  QAK - 2002/06/12
    * Fixed bug (#499) which allowed an "empty" compound or enumerated datatype
      (one with no members) to be used to create a dataset or committed to a
      file.  QAK - 2002/06/11
    * Fixed bug (#777) which allowed a compound datatype to be inserted into
      itself.  QAK - 2002/06/10
    * Fixed bug (#789) where creating 1-D dataset region reference caused the
      library to go into infinite loop.  QAK - 2002/06/10
    * Fixed bug (#699, fix provided by a user) where a scalar dataspace was
      written to the file and then subsequently queried with the
      H5Sget_simple_extent_type function, type was reported H5S_SIMPLE instead
      of H5S_SCALAR. EIP - 2002/06/04
    * Clear symbol table node "dirty" flag when flushing symbol tables to
      disk, to reduce I/O calls made & improve performance.  QAK - 2002/06/03
    * Fixed bug where an object's header could get corrupted in certain obscure
      situations where many objects were created in the file.  QAK - 2002/05/31
    * Fixed bug where read/write intent in file IDs created with H5Freopen
      was not being kept the same as the original file.  QAK - 2002/05/14
    * Fixed bug where selection offsets were not being used when iterating
      through point and hyperslab selections with H5Diterate().  QAK - 2002/04/29
    * Fixed bug where the data for several level deep nested compound &
      variable-length datatypes used for datasets were getting corrupted when
      written to the file.  QAK - 2002/04/17
    * Fixed bug where selection offset was being ignored for certain hyperslab
      selections when optimized I/O was being performed.  QAK - 2002/04/02
    * Added serial multi-gigabyte file size test.  "test/big -h" shows
      the help page.  AKC - 2002/03/29
    * Fixed bug where variable-length string type doesn't behave as
      string.  SLU - 2002/03/28
    * Fixed bug in H5Gget_objinfo() which was not setting the 'fileno'
      of the H5G_stat_t struct.  QAK - 2002/03/27
    * Fixed data corruption bug in hyperslab routines when contiguous
      hyperslab that spans entire dimension and is larger than type
      conversion buffer is attempted to be read.  QAK - 2002/03/26
    * Fixed bug where non-zero fill-value was not being read correctly from
      certain chunked datasets when using an "all" or contiguous hyperslab
      selection.  QAK - 2002/02/14
    * Fixed bug where a preempted chunk in the chunk data could still be
      used by an internal pointer and cause an assertion failure or core
      dump. QAK - 2002/02/13
    * Fixed bug where raw data re-allocated from the free-list would sometimes
      overlap with the metadata accumulator and get corrupted. QAK - 2002/01/23
    * Fixed bug where variable-length datatypes for attributes was not working
      correctly.
    * Retired the DPSS virtual file driver (--with-gridstorage configure
      option).
    * Corrected behavior of H5Tinsert to not allow compound datatype fields to
      be inserted past the end of the datatype.
    * Fixed the internal macros used to encode & decode file metadata, to avoid
      an unaligned access warning on IA64 machines.
    * Fixed an off-by-one error in H5Sselect_valid when hyperslab selections
      which would allow hyperslab selections which overlapped the edge of the
      selection by one element as valid.
    * Fixed a bug in internal B-tree code where a B-tree was not being copied
      correctly.
    * Fixed a bug in the 'big' test where quota limits weren't being detected
      properly if they caused close() to fail.
    * Fixed a bug where 'or'ing a hyperslab with a 'none' selection would
      fail.  Now adds that hyperslab as the first hyperlab in the selection.
    * Fixed a bug where appending a point selection to the current selection
      would not actually append the point when there were no points defined
      currently.
    * Fixed a bug where reading or writing chunked data which needed datatype
      conversion could result in data values getting corrupted.
    * Fixed a bug where reading an entire dataset wasn't being handled
      optimally when the dataset had unlimited dimensions.  Dataset is read
      in a single low-level I/O now, instead of being broken into separate
      pieces internally.
    * Fixed a bug when reading chunked datasets where the edge of the dataset
      would be incorrectly detected and generate an assertion failure.
    * Added new parallel hdf5 tests in t_mpi.  The new test checks if the
      filesystem or the MPI-IO can really handle greater than 2GB files.
      If it fails, it prints information message only without failing the
      test.
    * Fixed a bug in H5FD_mpio_flush() that might result in negative file seek
      if both MPIO and Split-file drivers are used together.
    * Fixed H5FDmpio.h to be C++ friendly by making Parallel HDF5 API's to be
      external to C++.
    * Fixed a bug of H5pubconf.h causing repeated definitions if it is included
      more than once.  hdf5.h now includes H5public.h which includes
      H5pubconf.h.  Applications should #include hdf5.h which handles multiple
      inclusion correctly.
    * Tweaked a few API functions to use 'size_t' instead of 'unsigned' or
      'hsize_t', which may cause errors in some cases.
    * Changed behavior of H5Tget_member_type to correctly emulate HDF5 v1.2.x
      when --enable-hdf5v1_2 configure flag is enabled.
    * Removed limitation that the data transfer buffer size needed to be
      set for datasets whose dimensions were too large for the 'all' selection
      code to handle.  Any size dimensioned datasets should be handled
      correctly now.
    * The allocation by alignment (H5Pset_alignment) feature code somehow
      got dropped in some 1.3.x version. Re-implemented it with "new and
      improved" algorithm.  It keeps track of "wasted" file-fragment in
      the free-list too.
    * IMPORTANT: Fixed file metadata corruption bug which could cause metadata
      data loss in certain situations.
    * Fixed build on Linux systems with --enable-static-exec flag. It now
      works correctly.
    * Fixed bug with non-zero userblock sizes causing raw data to not write
      correctly. 
    * The RCSID string in H5public.h was causing the C++ compiling problem
      because when it was included multiple times, C++ did not like multiple
      definitions of the same static variable.  All occurance of RCSID
      definition are removed since we have not used it consistently before.
    * Fixed bug where non-aligned hyperslab I/O on chunked datasets was
      causing errors during I/O
    * Fixed bug with contiguous hyperslabs not being detected, causing
      slower I/O than necessary.


Configuration
-------------

    * Added "--with-dmalloc" flag, to easily enable support for the 'dmalloc'
      debugging malloc implementation. -QAK, 2002/07/15
    * Can use just enable-threadsafe if the C compiler has builtin pthreads
      support.
    * Require HDF (a.k.a. hdf4) software that consists of a newer version
      of zlib library which consists of the compress2() function. Versions
      HDF version 4.1r3 and newer meets this requirement.  The compress2
      uses a newer compression algorithm used by the HDF5 library.  Also,
      4.1r3 has an hdp tool that can handle "loops" in Vgroups.
    * Added --enable-linux-lfs flag to allow more control over whether to enable
      or disable large file support on Linux.
    * Basic port to Compaq (nee DEC) Alpha OSF 5.
    * Changed the default value of $NPROCS from 2 to 3 since 3 processes
      have a much bigger chance catching parallel errors than just 2.
    * Fixed minor problem with configuration when users specified /usr/include
      and /usr/lib for the --with-* options that some compilers can't handle.
      BW - 2003/01/23


Tools
-----

    * The VL string bug(data and datatype cannot be shown) in h5dump is fixed.
      -SLU - 2002/11/18
    * Fixed segfault if h5dump was invoked with some options but no file (e.g.,
      h5dump -H). -AKC, 2002/10/15
    * Fixed limitation in h5dumper with object names which reached over 1024
      characters in length. We can now handle arbitrarily larger sizes for
      object names. BW - 2002/02/27
    * Fixed so that the "-i" flag works correctly with the h5dumper.
    * Fixed segfault when "-v" flag was used with the h5dumper.


Documentation
-------------
  o Library
  =========
    o General
    --------- 
      * API tracing has been improved. Nested API calls don't screw up the
        output format; function call and return event times can be logged;
        total time spent in each function can be logged.  The following
        HDF5_DEBUG environment variable words affect tracing:
	    trace   -- turn on/off basic tracing
	    ttimes  -- turn on tracing and report event times and
                       time spent in each API function.
            ttop    -- turn on tracing but display only top-level
                       API calls.

 
    o APIs
    ------
 
    o Performance
    -------------
      * Improved dataset creation time by about 30% (relative to the 1.4.x
        branch).


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

    * Added Fletcher32 checksum as a filter in pipeline.  It only works in 
      chunked dataset.  SLU - 2003/2/11
    * MPICH/MPE instrumentation feature added.  Use --enable-mpe to configure
      it.  AKC - 2003/1/3
    * New functions H5Gget_num_objs, H5Gget_objname_by_idx and H5Gget_objtype_by_idx 
      are added to the library.  SLU - 2002/11/25
    * H5Dget_offset is added to return the offset of a dataset's data relative
      to the beginning of the file.  SLU - 2002/11/7
    * Functions H5Tget_native_type and H5Tis_variable_str are added.  The first
      one reconstructs a datatype based on native memory datatype.  The second
      one checks if a datatype is variable string.  SLU - 2002/11/6
    * Added environment variable "HDF5_DISABLE_VERSION_CHECK", which disables
      the version checking between the header files and the library linked into
      an application if set to '1'.  This should be used with caution, mis-
      matched headers and library binaries can cause _serious_ problems.
      QAK - 2002/10/15
    * Added new API function to get the name of an object in a file, using
      an open ID (hid_t).  QAK - 2002/10/14
    * Added API functions to return pointer to low-level file handle
      (H5Fget_vfd_handle and H5FDget_vfd_handle) and related property list
      setting functions(H5Pset_family_offset and H5Pset_multi_type).
      SLU - 2002/09/30
    * Changed "H5P[set|get]_space_time" functions to "H5P[set|get]_alloc_time"
      Unify all symbolic names for these functions to use "alloc time" instead
      of other names.  QAK - 2002/09/13
    * Added "H5D_SPACE_ALLOC_INCR" setting to H5D_SPACE_ALLOC_EARLY and
      H5D_SPACE_ALLOC_LATE for H5Dset_space_time().  This allows chunked
      datasets to be incrementally allocated as in the 1.4.x branch.
      QAK - 2002/08/27
    * Compact dataset is added to the library.  The data will be stored in 
      the header message of dataset layout.  Space allocation time has to be
      EARLY.  No hyperslab is supported for parallel collective write.  There
      is no API changes except activating H5Pset_layout and H5Pget_layout for
      compact dataset.  -SLU, 2002/8/20
    * Added MPI-posix VFL driver.  This VFL driver uses MPI functions to
      coordinate actions, but performs I/O directly with POSIX sec(2)
      (i.e. open/close/read/write/etc.) calls.  This driver should _NOT_
      be used to access files that are not on a parallel filesystem.
      The following API functions were added:
            herr_t H5Pset_fapl_mpiposix(hid_t fapl_id, MPI_Comm comm);
            herr_t H5Pget_fapl_mpiposix(hid_t fapl_id, MPI_Comm *comm/*out*/);
        -QAK, 2002/07/15
    * Added environment variable flag to control whether creating MPI derived
      typed is preferred or not.  This can affect performance, depending on
      which way the MPI-I/O library is optimized for.  The default is set to
      prefer MPI derived types for collective raw data transfers, setting the
      HDF5_MPI_PREFER_DERIVED_TYPES environment variable to "0" (i.e.:
      "setenv HDF5_MPI_PREFER_DERIVED_TYPES 0") changes the preference to avoid
      using then whenever possible.  QAK - 2002/06/19
    * Changed MPI I/O routines to avoid creating MPI derived types (and thus
      needing to set the file view) for contiguous selections within datasets,
      which should result in some performance improvement for those types of
      selections.  QAK - 2002/06/18
    * Enable MPI type support for collective I/O to be enabled by default.
      This can be disabled by setting the HDF5_MPI_OPT_TYPES environment
      variable to the value "0".  QAK - 2002/06/14
    * Allow chunks in chunked datasets to be cached when parallel file is
      opened for read-only access (bug #709).  QAK - 2002/06/10
    * Added internal "small data" aggregation, which can reduce the number of
      actual I/O calls made, improving performance.  QAK - 2002/06/05
    * Improved internal metadata aggregation, which can reduce the number of
      actual I/O calls made, improving performance.  Additionally, this can
      reduce the size of files produced.  QAK - 2002/06/04
    * Improved internal metadata caching, which can reduce the number of actual
      I/O calls made by a substantial amount, improving
      performance.  QAK - 2002/06/03
    * Added 'closing' parameter to VFL 'flush' callback function and H5FDflush.
      This allows the library to indicate that the file will be closed
      immediately following the call to 'flush' and can be used to avoid actions
      that are duplicated in the VFL 'close' callback function.  QAK - 2002/05/20
    * Added feature to parallel chunk allocation routine to not write fill
      values to chunks allocated if the user has set the "fill time" to never.
      This can improve parallel I/O performance for chunked
      datasets.  QAK - 2002/05/17
    * Changed method for allocating chunked dataset blocks in parallel to only
      allocate blocks that don't already exist, instead of attempting to create
      all the blocks all the time.  This improves parallel I/O performance for
      chunked datasets.  QAK - 2002/05/17
    * Allowed the call to MPI_File_sync to be avoided when the file is going to
      immediately be closed, improving performance.  QAK - 2002/05/13
    * Allow the metadata writes to be shared among all processes, easing the
      burden on process 0.  QAK - 2002/05/10
    * New functions H5Glink2 and H5Gmove2 were added to allow link and move to
      be in different locations in the same file.  The old functions H5Glink 
      and H5Gmove remain valid.  SLU - 2002/04/26 
    * Fill-value's behaviors for contiguous dataset have been redefined.  
      Basicly, dataset won't allocate space until it's necessary.  Full details
      are available at http://hdf.ncsa.uiuc.edu/RFC/Fill_Value, at this moment.
      SLU - 2002/04/11
    * Added new routine "H5Dfill" to fill a selection with a particular value
      in memory.  QAK - 2002/04/09
    * A new query function H5Tget_member_index has been added for compound
      and enumeration data types, to retrieve member's index by name.
      SLU - 2002/04/05
    * Improved performance of "regular" hyperslab I/O when using MPI-IO and the
      datatype conversion is unneccessary.  QAK - 2002/04/02
    * Improved performance of single hyperslab I/O when datatype conversion is
      unneccessary.  QAK - 2002/04/02
    * New API function H5Dset_extent. Modifies the dimensions of a dataset, 
      allows change to a lower dimension. The unused space in the file is freed.
      PVN - 2002/03/31
    * Added new "H5Sget_select_type" API function to determine which type of
      selection is defined for a dataspace ("all", "none", "hyperslab" or
      "point"). QAK - 2002/02/07
    * Added support to read/write portions of chunks directly, if they are
      uncompressed and too large to cache.  This should speed up I/O on chunked
      datasets for a few more cases.  QAK - 2002/01/31
    * Parallel HDF5 is now supported on HP-UX 11.00 platforms.
    * Added H5Rget_obj_type() API function, which performs the same functionality
      as H5Rget_object_type(), but requires the reference type as a parameter
      in order to correctly handle dataset region references.  Moved
      H5Rget_object_type() to be only compiled into the library when v1.4
      compatibility is enabled.
    * Changed internal error handling macros to reduce code size of library by
      about 10-20%.
    * Added a new file access property, file close degree, to control file 
      close behavior.  It has four values, H5F_CLOSE_WEAK, H5F_CLOSE_SEMI,
      H5F_CLOSE_STRONG, and H5F_CLOSE_DEFAULT.  Two correspont functions 
      H5Pset_fclose_degree and H5Pget_fclose_degree are also provided.  Two 
      new functions H5Fget_obj_count and H5Fget_obj_ids are offerted to assist
      this new feature.  For full details, please refer to the reference 
      manual under the description of H5Fcreate, H5Fopen, H5Fclose and the 
      functions mentioned above. 
    * Removed H5P(get|set)_hyper_cache API function, since the property is no
      longer used.
    * Improved performance of non-contiguous hyperslabs (built up with
      several hyperslab selection calls).
    * Improved performance of single, contiguous hyperslabs when reading or
      writing.
    * As part of the transition to using generic properties everywhere, the
      parameter of H5Pcreate changed from H5P_class_t to hid_t, as well
      the return type of H5Pget_class changed from H5P_class_t to hid_t.
      Further changes are still necessary and will be documented here as they
      are made.
    * Added a new test to verify the information provided by the configure
      command.
    * The H5Pset_fapl_split() accepts raw and meta file names similar to the
      syntax of H5Pset_fapl_multi() in addition to what it used to accept.
    * Added perform programs to test the HDF5 library performance.  Programs
      are installed in directory perform/.
    * Added new checking in H5check_version() to verify the five HDF5 version
      information macros (H5_VERS_MAJOR, H5_VERS_MINOR, H5_VERS_RELEASE,
      H5_VERS_SUBRELEASE and H5_VERS_INFO) are consistent.
    * Added a new public macro, H5_VERS_INFO, which is a string holding
      the HDF5 library version information.  This string is also compiled
      into all HDF5 binary code which helps to identify the version
      information of the binary code.  One may use the Unix strings
      command on the binary file and looks for the pattern "HDF5 library
      version".
    * Added a parallel HDF5 example examples/ph5example.c to illustrate
      the basic way of using parallel HDF5.
    * Added two simple parallel performance tests as mpi-perf.c (MPI
      performance) and perf.c (PHDF5 performance) in testpar.
    * Improved regular hyperslab I/O by about a factor of 6 or so.
    * Modified the Pablo build procedure to permit building of the instrumented
      library to link either with the Trace libraries as before or with the
      Pablo Performance Caputure Facility.
    * Verified correct operation of library on Solaris 2.8 in both 64-bit and
      32-bit compilation modes.  See INSTALL document for instructions on
      compiling the distribution with 64-bit support.
    * Parallel HDF5 now runs on the HP V2500 and HP N4000 machines.
    * H5 <-> GIF convertor has been added. This is available under 
      tools/gifconv. The convertor supports the ability to create animated
      gifs as well.
    * Added a global string variable H5_lib_vers_info_g which holds the
      HDF5 library version information.  This can be used to identify
      an hdf5 library or hdf5 application binary.
      Also added a verification of the consistency between H5_lib_vers_info_g
      and other version information in the source code.
    * File sizes greater than 2GB are now supported on Linux systems with
      version 2.4.x or higher kernels.
    * F90 APIs are available on HPUX 11.00 and IBM SP platforms.
    * F90 static library is available on Windows platforms. See
      INSTALL_Windows.txt for details.
    * F90 API:
        - Added aditional parameter "dims" to the h5dread/h5dwrite and
          h5aread/h5awrite subroutines. This parameter is 1D array of size
          7 and contains the sizes of the data buffer dimensions. 
        - F90 subroutines h5dwrite_f, h5dread_f, h5awrite_f and h5aread_f were 
          overloaded with "dims" argument to be assumed size array of type 
          INTEGER(HSIZE_T). We recommend to use the subroutines with the new
          type.  Module subroutines that accept "dims" as INTEGER array of size
          7 will be deprecated in 1.6 release. 
          EIP - 2002/05/06 
        - Added the following functions to the
              Library APIs:
                      h5get_libversion_f  h5dont_atexit_f
                      h5check_version_f   h5garbage_collect_f
                                                              EIP - 2002/09/24
              H5F APIs:
                      h5fget_obj_count_f  h5fget_obj_ids_f
                                                              EIP - 2002/10/01
              H5G APIs:
                      h5glink2_f and h5gmove2_f
                                                              EIP - 2002/09/25
              H5P APIs:
                      h5pequal_f 
                      h5pget(set)_fclose_degree_f
                      h5pget(set)_buffer_f

              H5T APIs:
                      h5tget_member_index_f
                                                              EIP - 2002/10/01
                      
    * C++ API:
        - Added two new member functions: Exception::getFuncName() and
          Exception::getCFuncName() to provide the name of the member
          function, where an exception is thrown.
        - IdComponent::operator= becomes a virtual function because
          DataType, DataSpace, and PropList provide their own
          implementation.  The new operator= functions invoke H5Tcopy,
          H5Scopy, and H5Pcopy to make a copy of a datatype, dataspace,
          and property list, respectively.
    * A helper script called ``h5cc'', which helps compilation of HDF5
      programs, is now distributed with HDF5. See the reference manual
      for information on how to use this feature.

Support for new platforms and languages
=======================================
    * Parallel Fortran Library works now on HP-UX B.11.00 Sys V
      EIP - 2002/05/06

Platforms Tested
================

  AIX 4.3.3.0 (IBM SP powerpc)  mpcc_r 3.6.6
  Cray T3E sn6711 2.0.5.45      Cray Standard C Version 6.4.0.0
                                Cray Fortran Version 3.4.0.2
  Cray SV1 sn9605 10.0.0.7      Cray Standard C Version 6.4.0.0
                                Cray Fortran Version 3.4.0.2
  FreeBSD 4.6                   gcc 2.95.4
                                g++ 2.95.4
  HP-UX B.10.20                 HP C  HP92453-01 A.10.32.30
  HP-UX B.11.00                 HP C  HP92453-01 A.11.00.13
                                HP C  HP92453-01 A.11.01.20
  IRIX 6.5                      MIPSpro cc 7.30
  IRIX64 6.5 (64 & n32)         MIPSpro cc 7.3.1m
                                mpt.1.4.0.2
                                mpich-1.2.1
  Linux 2.4.18                  gcc-2.95.3
                                g++ 2.95.3
  Linux 2.2.18smp               gcc-2.95.2
                                g++ 2.95.2
                                pgf90 3.1-3
  OSF1 V4.0                     DEC-V5.2-040
                                Digital Fortran 90 V4.1-270
  SunOS 5.6                     WorkShop Compilers 5.0 98/12/15 C 5.0 
  (Solaris 2.6)                 WorkShop Compilers 5.0 99/10/25 Fortran 90
                                       2.0 Patch 107356-04
                                Workshop Compilers 5.0 98/12/15 C++ 5.0
  SunOS 5.7                     WorkShop Compilers 5.0 98/12/15 C 5.0
  (Solaris 2.7)                 WorkShop Compilers 5.0 99/10/25 Fortran 90
                                       2.0 Patch 107356-04
                                Workshop Compilers 5.0 98/12/15 C++ 5.0
  TFLOPS r1.0.4 v4.0            mpich-1.2.1 with local changes
  Windows NT4.0, 2000 (NT5.0)   MSVC++ 6.0
  Windows 98                    MSVC++ 6.0


Supported Configuration Features Summary
========================================

    In the tables below
          y  = tested and supported
          n  = not supported or not tested in this release
          x  = not working in this release
         ( ) = footnote appears below second table


    Platform       C  C         F90  F90       C++   Shared     zlib  Tools
                      parallel       parallel        libraries
                                                     (5)
    Solaris2.7     y  y (1)     y    n         y     y          y     y
    Solaris2.8 64  y  n         y    n         y     y          y     y
    Solaris2.8 32  y  y (1)     y    n         y     y          y     y
    IA-64          y  n         n    n         n     n          y     y 
    IRIX6.5        y  y (1)     n    n         n     y          y     y
    IRIX64_6.5 64  y  y (2)     y    y         n     y          y     y
    IRIX64_6.5 32  y  y (2)     n    n         n     y          y     y
    HPUX10.20      y  n         y    n         n     y          y     y
    HPUX11.00      y  y         y    n         n     y          y     y
    HPUX11 SysV    y  y         y    y         n     y          y     y
    DECOSF         y  n         y    n         y     y          y     y
    T3E            y  y         y    y         n     n          y     y
    SV1            y  n         y    n         n     n          y     y
    TFLOPS         y  y (1)     n    n         n     n          y     y (4)
    AIX-4.3 SP2    y  y         y    y         n     n          y     n
    AIX-4.3 SP3    y  y         y    y         y     n          y     n
    Win2000        y  n         y    n         y (6) y          y     y
    Win98          y  n         y    n         y (6) y          y     y
    WinNT          y  n         y    n         y (6) y          y     y
    WinNT CW       y  n         n    n         n     n          y     y
    FreeBSD        y  n         n    n         y     y          y     y
    Linux 2.2      y  y (1)     y    n         y     y          y     y
    Linux 2.4      y  y (1)     n    n         y     y          y     y


    Platform       1.2            static-   Thread-  SRB  GASS	STREAM-
                   compatibility  exec      safe                VFD
    Solaris2.7     n              x         y        n    n     y
    Solaris2.8 64  n              y         n        n    n     y
    Solaris2.8 32  n              x         y        n    n     y
    IA-64          n              n         n        n    n     y   
    IRIX6.5        n              x         y        n    n     y
    IRIX64_6.5 64  n              x         y        n    y     y
    IRIX64_6.5 32  n              x         y        n    y     y
    HPUX10.20      n              y         n        n    n     y
    HPUX11.00      n              x         n        n    n     y
    HPUX11 SysV    n              x         n        n    n     y
    DECOSF         n              y         n        n    n     y
    T3E            n              y         n        n    n     y
    SV1            n              y         n        n    n     y
    TFLOPS         n              y         n        n    n     n
    AIX-4.3 SP2    n              y (3)     n        n    n     y
    AIX-4.3 SP3    n              y         n        n    n     y
    Win2000        n              y         n        n    n     n
    Win98          n              y         n        n    n     n
    WinNT          n              y         n        n    n     n
    WinNT CW       n              n         n        n    n     n
    FreeBSD        n              y         y        n    n     y
    Linux 2.2      n              y         y        n    n     y
    Linux 2.4      n              y         y        n    n     y


    Footnotes:  (1) Using mpich.
                (2) Using mpt and mpich.
                (3) When configured with static-exec enabled, tests fail 
                    in serial mode.
                (4) No HDF4-related tools.
                (5) Shared libraries are provided only for the C library.
                (6) Exception of (5): DLL is available for C++ API on Windows


Known Problems
==============
* Datasets or attributes which have a variable-length string datatype are not
  printing correctly with h5dump and h5ls.

* The stream-vfd test uses ip port 10007 for testing. If another
  application is already using that port address, the test will hang
  indefinitely and has to be terminated by the kill command. To try the
  test again, change the port address in test/stream_test.c to one not
  being used in the host.

* The --enable-static-exec configure flag fails to compile for Solaris
  platforms. This is due to the fact that not all of the system
  libraries on Solaris are available in a static format.

  The --enable-static-exec configure flag also fails to correctly compile
  on IBM SP2 platform for the serial mode. The parallel mode works fine
  with this option.
  
  It is suggested that you don't use this option on these platforms
  during configuration.

* With the gcc 2.95.2 compiler, HDF 5 uses the `-ansi' flag during
  compilation. The ANSI version of the compiler complains about not being
  able to handle the `long long' datatype with the warning:

        warning: ANSI C does not support `long long'
  
  This warning is innocuous and can be safely ignored.

* SunOS 5.6 with C WorkShop Compilers 4.2:  Hyperslab selections will 
  fail if library is compiled using optimization of any level.

* h5toh4 converter fails two cases (tstr.h5 and tmany.h5) for release dll
  version on windows 2000 and NT. The reason is possibly due to windows
  NT DLL convention on freeing memory. It seems that memory cannot be
  free across library or DLL. It is still under investigated.

* The Stream VFD was not tested yet under Windows. It is not supported
  in the TFLOPS machine.

* Shared library option is broken for IBM SP and some Origin 2000
  platforms. One needs to run ./configure with '--disable-shared'

* The ./dsets tests failed in the TFLOPS machine if the test program,
  dsets.c, is compiled with the -O option.  The hdf5 library still works
  correctly with the -O option.  The test program works fine if it is
  compiled with -O1 or -O0.  Only -O (same as -O2) causes the test
  program to fail.

* Certain platforms give false negatives when testing h5ls:

    - Solaris x86 2.5.1, Cray T3E and Cray J90 give errors during testing
      when displaying object references in certain files.  These are
      benign differences due to the difference in sizes of the objects
      created on those platforms. h5ls appears to be dumping object
      references correctly.

    - Cray J90 (and Cray T3E?) give errors during testing when displaying
      some floating-point values. These are benign differences due to
      the different precision in the values displayed and h5ls appears to
      be dumping floating-point numbers correctly.

* Before building HDF5 F90 Library from source on Crays (T3E and J90) 
  replace H5Aff.f90, H5Dff.f90 and H5Pff.f90 files in the fortran/src
  subdirectory in the top level directory with the Cray-specific files
  from the site:

  ftp://hdf.ncsa.uiuc.edu/pub/ougoing/hdf5/hdf5-1.4.0-beta/F90_source_for_Crays

* On IA32 and IA64 systems, if you use a compiler other than GCC (such as
  Intel's ecc or icc compilers), you will need to modify the generated
  "libtool" program after configuration is finished. On or around line 104 of
  the libtool file, there are lines which look like:

      # How to pass a linker flag through the compiler.
      wl=""

  change these lines to this:

      # How to pass a linker flag through the compiler.
      wl="-Wl,"

  UPDATE: This is now done automatically by the configure script. However, if
  you still experience a problem, you may want to check this line in the
  libtool file and make sure that it has the correct value.