Brings file locking changes from develop

1 files changed, 110 insertions, 1 deletions

diff --git a/release_docs/RELEASE.txt b/release_docs/RELEASE.txt
index 04501b1..53467d5 100644
--- a/release_docs/RELEASE.txt
+++ b/release_docs/RELEASE.txt
@@ -251,6 +251,55 @@ New Features
 
       (ADB - 2019/04/15, HDFFV-10741)
 
+    - 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)
+
 
     Library:
     --------
@@ -292,11 +341,49 @@ New Features
 
       (JTH - 2019/10/07)
 
+    - 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.
 
-     Parallel Library:
+      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.
+
+      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)
+
+    Parallel Library:
     -----------------
     -
 
+    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)
+
     C++ Library:
     ------------
     - Added new wrappers for H5Pset/get_create_intermediate_group()
@@ -305,6 +392,15 @@ New Features
 
       (BMR - 2019/04/22, HDFFV-10622)
 
+    - 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:
     ----------------
@@ -312,6 +408,19 @@ New Features
 
       (JTH - 2019/04/30)
 
+    - 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:
     ------