Merge pull request #56 from HDFGroup/feature/vfd_swmr

Feature/vfd swmr

51 files changed, 942 insertions, 190 deletions

diff --git a/.github/workflows/pr-check.yml b/.github/workflows/pr-check.yml
index 33608b5..62fd0d8 100644
--- a/.github/workflows/pr-check.yml
+++ b/.github/workflows/pr-check.yml
@@ -174,6 +174,8 @@ jobs:
     # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
     - name: Get Sources
       uses: actions/checkout@v2
+      with:
+        submodules: 'true'
 
     - name: Autotools Configure 
       if: matrix.generator == 'autogen'
diff --git a/COPYING b/COPYING
index 9d32232..6230db2 100644
--- a/COPYING
+++ b/COPYING
@@ -46,6 +46,14 @@ works thereof, in binary and source code form.
 -----------------------------------------------------------------------------
 -----------------------------------------------------------------------------
 
+Limited portions of HDF5 were developed by Akadio, Inc. Akadio's Copyright
+Notice and Licensing Terms can be found here: COPYING_AKADIO file in this
+directory or at 
+http://support.hdfgroup.org/ftp/HDF5/releases/COPYING_AKADIO. 
+
+-----------------------------------------------------------------------------
+-----------------------------------------------------------------------------
+
 Limited portions of HDF5 were developed by Lawrence Berkeley National 
 Laboratory (LBNL). LBNL's Copyright Notice and Licensing Terms can be
 found here: COPYING_LBNL_HDF5 file in this directory or at 
diff --git a/COPYING_AKADIO b/COPYING_AKADIO
new file mode 100644
index 0000000..e0d58e3
--- /dev/null
+++ b/COPYING_AKADIO
@@ -0,0 +1,45 @@
+Copyright Notice and License Terms for 
+VFD SWMR (Virtual File Driver Single Writer/Multiple Reader)
+-----------------------------------------------------------------------------
+VFD SWMR (Virtual File Driver Single Writer/Multiple Reader)
+Copyright © 2019, Akadio, Inc. 
+
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted for any purpose (including commercial purposes)
+provided that the following conditions are met:
+
+1.	Redistributions of source code must retain the above copyright notice,
+    this list of conditions, and the following disclaimer.
+
+2.	Redistributions in binary form must reproduce the above copyright notice,
+    this list of conditions, and the following disclaimer in the
+    documentation and/or materials provided with the distribution.
+
+3.	Neither the name of Akadio nor the name of any Contributor may be used
+    to endorse or promote products derived from this software without
+    specific prior written permission from Akadio, Inc.
+
+DISCLAIMER: 
+THIS SOFTWARE IS PROVIDED BY AKADIO, INC. AND THE CONTRIBUTORS "AS IS" WITH
+NO WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED. IN NO EVENT SHALL
+AKADIO, INC. OR THE CONTRIBUTORS BE LIABLE FOR ANY DAMAGES SUFFERED BY THE
+USERS ARISING OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.
+ 
+You are under no obligation whatsoever to provide any bug fixes, patches, or
+upgrades to the features, functionality or performance of the source code
+("Enhancements") to anyone; however, if you choose to make your Enhancements
+available either publicly, or directly to Akadio, Inc., without imposing a
+separate written license agreement for such Enhancements, then you hereby
+grant the following license: a non-exclusive, royalty-free perpetual license
+to install, use, modify, prepare derivative works, incorporate into other
+computer software, distribute, and sublicense such enhancements or derivative
+works thereof, in binary and source code form.
+
+-----------------------------------------------------------------------------
+This work was sponsored by the U.S. Department of Energy under Award Number
+DE-SC0018504.
+-----------------------------------------------------------------------------
+
diff --git a/MANIFEST b/MANIFEST
index bad97be..c3a0091 100644
--- a/MANIFEST
+++ b/MANIFEST
@@ -25,6 +25,7 @@
 ./.h5chkright.ini      _DO_NOT_DISTRIBUTE_
 ./ACKNOWLEDGMENTS
 ./COPYING
+./COPYING_AKADIO
 ./COPYING_LBNL_HDF5
 ./MANIFEST
 ./Makefile.dist
@@ -3048,6 +3049,11 @@
 ./utils/mirror_vfd/mirror_server_stop.c
 ./utils/mirror_vfd/mirror_writer.c
 
+# VFD SWMR utilities
+./utils/vfd_swmr/README.md
+./utils/vfd_swmr/Makefile.am
+./utils/vfd_swmr/aux_process.c
+
 # high level libraries
 ./hl/Makefile.am
 ./hl/examples/Makefile.am
diff --git a/config/cmake/libhdf5.settings.cmake.in b/config/cmake/libhdf5.settings.cmake.in
index d80b0f8..a7c5f37 100644
--- a/config/cmake/libhdf5.settings.cmake.in
+++ b/config/cmake/libhdf5.settings.cmake.in
@@ -81,6 +81,7 @@ Dimension scales w/ new references: @DIMENSION_SCALES_WITH_NEW_REF@
                         Mirror VFD: @H5_HAVE_MIRROR_VFD@
                 (Read-Only) S3 VFD: @H5_HAVE_ROS3_VFD@
               (Read-Only) HDFS VFD: @H5_HAVE_LIBHDFS@
+                 Auxiliary Process: @H5_HAVE_AUX_PROCESS@
                            dmalloc: @H5_HAVE_LIBDMALLOC@
     Packages w/ extra debug output: @INTERNAL_DEBUG_OUTPUT@
                        API Tracing: @HDF5_ENABLE_TRACE@
diff --git a/configure.ac b/configure.ac
index ab55f3e..f8a1e4d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -3171,6 +3171,30 @@ fi
 AM_CONDITIONAL([MIRROR_VFD_CONDITIONAL], [test "X$MIRROR_VFD" = "Xyes"])
 
 ## ----------------------------------------------------------------------
+## Check whether the auxiliary process for the VFD SWMR should be built.
+##
+AC_SUBST([AUX_PROCESS])
+
+## Default is no auxiliary process
+AUX_PROCESS=no
+
+AC_MSG_CHECKING([if the auxiliary process is enabled])
+
+AC_ARG_ENABLE([aux-process],
+              [AS_HELP_STRING([--enable-aux-process],
+                              [Build the auxiliary process for the VFD SWMR.
+                               [default=no]])],
+              [AUX_PROCESS=$enableval], [AUX_PROCESS=no])
+
+if test "X$AUX_PROCESS" = "Xyes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE([HAVE_AUX_PROCESS], [1],
+            [Define whether the auxiliary process is compiled])
+else
+    AC_MSG_RESULT([no])
+fi
+
+## ----------------------------------------------------------------------
 ## Check if Read-Only S3 virtual file driver is enabled by --enable-ros3-vfd
 ##
 AC_SUBST([ROS3_VFD])
@@ -4063,6 +4087,7 @@ AC_CONFIG_FILES([src/libhdf5.settings
                  testpar/testpflush.sh
                  utils/Makefile
                  utils/mirror_vfd/Makefile
+                 utils/vfd_swmr/Makefile
                  tools/Makefile
                  tools/lib/Makefile
                  tools/libtest/Makefile
diff --git a/examples/credel.c b/examples/credel.c
index 4591d94..b90e70c 100644
--- a/examples/credel.c
+++ b/examples/credel.c
@@ -1,3 +1,16 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by The HDF Group.                                               *
+ * Copyright by Akadio, Inc.                                                 *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5.  The full HDF5 copyright notice, including     *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the COPYING file, which can be found at the root of the source code       *
+ * distribution tree, or in https://www.hdfgroup.org/licenses.               *
+ * If you do not have access to either file, you may request a copy from     *
+ * help@hdfgroup.org.                                                        *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
 #include <assert.h>
 #include <err.h>
 #include <errno.h>
diff --git a/examples/gaussians.c b/examples/gaussians.c
index 413bc03..515fac3 100644
--- a/examples/gaussians.c
+++ b/examples/gaussians.c
@@ -1,3 +1,16 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by The HDF Group.                                               *
+ * Copyright by Akadio, Inc.                                                 *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5.  The full HDF5 copyright notice, including     *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the COPYING file, which can be found at the root of the source code       *
+ * distribution tree, or in https://www.hdfgroup.org/licenses.               *
+ * If you do not have access to either file, you may request a copy from     *
+ * help@hdfgroup.org.                                                        *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
 #include <assert.h>
 #include <curses.h>
 #include <err.h>
diff --git a/examples/h5_dtransform.c b/examples/h5_dtransform.c
index a364ec1..acabd1e 100644
--- a/examples/h5_dtransform.c
+++ b/examples/h5_dtransform.c
@@ -1,6 +1,5 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
  * Copyright by The HDF Group.                                               *
- * Copyright by the Board of Trustees of the University of Illinois.         *
  * All rights reserved.                                                      *
  *                                                                           *
  * This file is part of HDF5.  The full HDF5 copyright notice, including     *
diff --git a/examples/nbcompat.c b/examples/nbcompat.c
index aa67623..cfa0dcd 100644
--- a/examples/nbcompat.c
+++ b/examples/nbcompat.c
@@ -1,3 +1,16 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by The HDF Group.                                               *
+ * Copyright by Akadio, Inc.                                                 *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5.  The full HDF5 copyright notice, including     *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the COPYING file, which can be found at the root of the source code       *
+ * distribution tree, or in https://www.hdfgroup.org/licenses.               *
+ * If you do not have access to either file, you may request a copy from     *
+ * help@hdfgroup.org.                                                        *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
 #include "nbcompat.h"
 
 size_t
diff --git a/examples/nbcompat.h b/examples/nbcompat.h
index c528ca4..ff4f677 100644
--- a/examples/nbcompat.h
+++ b/examples/nbcompat.h
@@ -1,3 +1,16 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by The HDF Group.                                               *
+ * Copyright by Akadio, Inc.                                                 *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5.  The full HDF5 copyright notice, including     *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the COPYING file, which can be found at the root of the source code       *
+ * distribution tree, or in https://www.hdfgroup.org/licenses.               *
+ * If you do not have access to either file, you may request a copy from     *
+ * help@hdfgroup.org.                                                        *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
 #ifndef NB_COMPAT_H
 #define NB_COMPAT_H
 
diff --git a/src/H5FDvfd_swmr.c b/src/H5FDvfd_swmr.c
index 73d8df4..3517517 100644
--- a/src/H5FDvfd_swmr.c
+++ b/src/H5FDvfd_swmr.c
@@ -1,5 +1,6 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
  * Copyright by The HDF Group.                                               *
+ * Copyright by Akadio, Inc.                                                 *
  * All rights reserved.                                                      *
  *                                                                           *
  * This file is part of HDF5.  The full HDF5 copyright notice, including     *
diff --git a/src/H5FDvfd_swmr.h b/src/H5FDvfd_swmr.h
index 096d5fb..dd1b452 100644
--- a/src/H5FDvfd_swmr.h
+++ b/src/H5FDvfd_swmr.h
@@ -1,5 +1,6 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
  * Copyright by The HDF Group.                                               *
+ * Copyright by Akadio, Inc.                                                 *
  * All rights reserved.                                                      *
  *                                                                           *
  * This file is part of HDF5.  The full HDF5 copyright notice, including     *
diff --git a/src/H5FDvfd_swmr_instr.c b/src/H5FDvfd_swmr_instr.c
index 6f309d2..53d6161 100644
--- a/src/H5FDvfd_swmr_instr.c
+++ b/src/H5FDvfd_swmr_instr.c
@@ -1,5 +1,6 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
  * Copyright by The HDF Group.                                               *
+ * Copyright by Akadio, Inc.                                                 *
  * All rights reserved.                                                      *
  *                                                                           *
  * This file is part of HDF5.  The full HDF5 copyright notice, including     *
diff --git a/src/H5FDvfd_swmr_private.h b/src/H5FDvfd_swmr_private.h
index 12fd2e2..5b6d300 100644
--- a/src/H5FDvfd_swmr_private.h
+++ b/src/H5FDvfd_swmr_private.h
@@ -1,5 +1,6 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
  * Copyright by The HDF Group.                                               *
+ * Copyright by Akadio, Inc.                                                 *
  * All rights reserved.                                                      *
  *                                                                           *
  * This file is part of HDF5.  The full HDF5 copyright notice, including     *
diff --git a/src/H5Fvfd_swmr.c b/src/H5Fvfd_swmr.c
index 372ae19..8e29f06 100644
--- a/src/H5Fvfd_swmr.c
+++ b/src/H5Fvfd_swmr.c
@@ -1,5 +1,6 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
  * Copyright by The HDF Group.                                               *
+ * Copyright by Akadio, Inc.                                                 *
  * All rights reserved.                                                      *
  *                                                                           *
  * This file is part of HDF5.  The full HDF5 copyright notice, including     *
diff --git a/src/H5MV.c b/src/H5MV.c
index 1246f4b..9139480 100644
--- a/src/H5MV.c
+++ b/src/H5MV.c
@@ -1,6 +1,6 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
  * Copyright by The HDF Group.                                               *
- * Copyright by the Board of Trustees of the University of Illinois.         *
+ * Copyright by Akadio, Inc.                                                 *
  * All rights reserved.                                                      *
  *                                                                           *
  * This file is part of HDF5.  The full HDF5 copyright notice, including     *
diff --git a/src/H5MVmodule.h b/src/H5MVmodule.h
index fdfe036..d8862ee 100644
--- a/src/H5MVmodule.h
+++ b/src/H5MVmodule.h
@@ -1,5 +1,6 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
  * Copyright by The HDF Group.                                               *
+ * Copyright by Akadio, Inc.                                                 *
  * All rights reserved.                                                      *
  *                                                                           *
  * This file is part of HDF5.  The full HDF5 copyright notice, including     *
@@ -10,14 +11,17 @@
  * help@hdfgroup.org.                                                        *
  * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
-/*
- * Programmer:	Quincey Koziol <koziol@hdfgroup.org>
- *		Saturday, September 12, 2015
+/*-------------------------------------------------------------------------
  *
- * Purpose:	This file contains declarations which define macros for the
- *		H5MV package.  Including this header means that the source file
- *		is part of the H5MV package.
+ * Created:             H5MVmodule.h
+ *
+ * Purpose:             This file contains declarations which define macros for
+ *                      the H5MV package.  Including this header means that the
+ *                      source file is part of the H5MV package.
+ *
+ *-------------------------------------------------------------------------
  */
+
 #ifndef _H5MVmodule_H
 #define _H5MVmodule_H
 
diff --git a/src/H5MVpkg.h b/src/H5MVpkg.h
index 2d564e6..bd75595 100644
--- a/src/H5MVpkg.h
+++ b/src/H5MVpkg.h
@@ -1,6 +1,6 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
  * Copyright by The HDF Group.                                               *
- * Copyright by the Board of Trustees of the University of Illinois.         *
+ * Copyright by Akadio, Inc.                                                 *
  * All rights reserved.                                                      *
  *                                                                           *
  * This file is part of HDF5.  The full HDF5 copyright notice, including     *
@@ -11,14 +11,17 @@
  * help@hdfgroup.org.                                                        *
  * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
-/*
- * Programmer:  Quincey Koziol <koziol@hdfgroup.org>
- *              Tuesday, January 8, 2008
+/*-------------------------------------------------------------------------
  *
- * Purpose:     This file contains declarations which are visible only within
- *              the H5MV package.  Source files outside the H5MV package should
- *              include H5MVprivate.h instead.
+ * Created:             H5MVpkg.h
+ *
+ * Purpose:             This file contains declarations which are visible only
+ *                      within the H5MV package.  Source files outside the
+ *                      H5MV package should include H5MVprivate.h instead.
+ *
+ *-------------------------------------------------------------------------
  */
+
 #if !(defined H5MV_FRIEND || defined H5MV_MODULE)
 #error "Do not include this file outside the H5MV package!"
 #endif
diff --git a/src/H5MVprivate.h b/src/H5MVprivate.h
index edd4765..2332ad3 100644
--- a/src/H5MVprivate.h
+++ b/src/H5MVprivate.h
@@ -1,6 +1,6 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
  * Copyright by The HDF Group.                                               *
- * Copyright by the Board of Trustees of the University of Illinois.         *
+ * Copyright by Akadio, Inc.                                                 *
  * All rights reserved.                                                      *
  *                                                                           *
  * This file is part of HDF5.  The full HDF5 copyright notice, including     *
@@ -15,10 +15,11 @@
  *
  * Created:             H5MVprivate.h
  *
- * Purpose:             Private header file for file memory management.
+ * Purpose:             Private header file for VFD SWMR free space mangement
  *
  *-------------------------------------------------------------------------
  */
+
 #ifndef _H5MVprivate_H
 #define _H5MVprivate_H
 
diff --git a/src/H5MVsection.c b/src/H5MVsection.c
index 8f80619..dc57e2f 100644
--- a/src/H5MVsection.c
+++ b/src/H5MVsection.c
@@ -1,6 +1,6 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
  * Copyright by The HDF Group.                                               *
- * Copyright by the Board of Trustees of the University of Illinois.         *
+ * Copyright by Akadio, Inc.                                                 *
  * All rights reserved.                                                      *
  *                                                                           *
  * This file is part of HDF5.  The full HDF5 copyright notice, including     *
@@ -11,12 +11,14 @@
  * help@hdfgroup.org.                                                        *
  * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
-/*
- * Programmer:	Quincey Koziol <koziol@hdfgroup.org>
- *              Tuesday, January  8, 2008
+/*-------------------------------------------------------------------------
  *
- * Purpose:	Free space section callbacks for file.
+ * Created:             H5MVsection.c
  *
+ * Purpose:             Free-space section callbacks for VFD SWMR's metadata
+ *                      file
+ *
+ *-------------------------------------------------------------------------
  */
 
 /****************/
diff --git a/src/H5retry_private.h b/src/H5retry_private.h
index 4b26009..d4ef99f 100644
--- a/src/H5retry_private.h
+++ b/src/H5retry_private.h
@@ -1,5 +1,6 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
  * Copyright by The HDF Group.                                               *
+ * Copyright by Akadio, Inc.                                                 *
  * All rights reserved.                                                      *
  *                                                                           *
  * This file is part of HDF5.  The full HDF5 copyright notice, including     *
diff --git a/test/stubs.c b/test/stubs.c
index 33ac027..e508b14 100644
--- a/test/stubs.c
+++ b/test/stubs.c
@@ -1,6 +1,6 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
  * Copyright by The HDF Group.                                               *
- * Copyright by the Board of Trustees of the University of Illinois.         *
+ * Copyright by Akadio, Inc.                                                 *
  * All rights reserved.                                                      *
  *                                                                           *
  * This file is part of HDF5.  The full HDF5 copyright notice, including     *
diff --git a/test/supervise.subr b/test/supervise.subr
index d2b0395..40472d3 100644
--- a/test/supervise.subr
+++ b/test/supervise.subr
@@ -1,6 +1,17 @@
-#!/bin/sh
-
+#!/us/bin/env bash
+#
+# Copyright by The HDF Group.
+# Copyright by Akadio, Inc.
 #
+# This file is part of HDF5.  The full HDF5 copyright notice, including
+# terms governing use, modification, and redistribution, is contained in
+# the COPYING file, which can be found at the root of the source code
+# distribution tree, or in https://www.hdfgroup.org/licenses.
+# If you do not have access to either file, you may request a copy from
+# help@hdfgroup.org.
+#
+# Tests for the vfd swmr feature.
+
 # catch_out_err_and_rc outbase command [arguments]
 #
 # Run `command` with any `arguments` provided.  Redirect `command`'s
diff --git a/test/testvfdswmr.sh.in b/test/testvfdswmr.sh.in
index 176e1e5..b47516f 100644
--- a/test/testvfdswmr.sh.in
+++ b/test/testvfdswmr.sh.in
@@ -1,18 +1,17 @@
 #!/us/bin/env bash
 #
 # Copyright by The HDF Group.
-# Copyright by the Board of Trustees of the University of Illinois.
-# All rights reserved.
+# Copyright by Akadio, Inc.
 #
 # This file is part of HDF5.  The full HDF5 copyright notice, including
 # terms governing use, modification, and redistribution, is contained in
 # the COPYING file, which can be found at the root of the source code
-# distribution tree, or in https://www.hdfgroup.org/releases.
+# distribution tree, or in https://www.hdfgroup.org/licenses.
 # If you do not have access to either file, you may request a copy from
 # help@hdfgroup.org.
 #
 # Tests for the vfd swmr feature.
-#
+
 ###############################################################################
 # VFD SWMR concurrent tests which are modified from existing swmr concurrent tests.
 # This is copied and modified from testswmr.sh.in
@@ -152,11 +151,11 @@ all_tests="generator expand shrink expand_shrink sparse vlstr_null vlstr_oob zoo
 all_tests="${all_tests} groups groups_attrs groups_ops few_big many_small"
 
 # For exhaustive run, add: 
-#   attrdset, dsetops, dsetchks,
+#   attrdset, dsetops, dsetops_ref, dsetchks
 #   os_groups_attrs, os_groups_ops, os_groups_seg, independ_wr,
 #   gfail_entry_length, gfail_checksum, gfail_page_size, gfail_index_space
 if [[ "$HDF5TestExpress" -eq 0 ]] ; then         # exhaustive run
-    all_tests="${all_tests} attrdset dsetops dsetchks"
+    all_tests="${all_tests} attrdset dsetops dsetops_ref dsetchks"
     all_tests="${all_tests} os_groups_attrs os_groups_ops os_groups_seg independ_wr"
     all_tests="${all_tests} gfail_entry_length gfail_checksum gfail_page_size gfail_index_space"
 fi
@@ -1095,6 +1094,16 @@ for options in "-d 1" "-d 1 -F" "-d 2 -l 16" "-d 2 -F -l 16" "-d 1 -t" "-d 1 -t
         # first dimension (up to 25 1x16x16)
         #
 
+        # Launch the auxiliary process for testing NFS if the --enable-aux-process option is enabled for configuration.
+        # If it isn't enabled, the auxiliary process simply exit without executing any code.  For the testing case of
+        # VDS across multiple files (-M option), the program also skips for future support.
+        if [[ $options == *"-M"* ]]; then
+	    catch_out_err_and_rc aux_process ../../utils/vfd_swmr/aux_process -a mdfile bigset_updater &
+        else
+	    catch_out_err_and_rc aux_process ../../utils/vfd_swmr/aux_process mdfile bigset_updater &
+        fi
+        pid_aux_proc=$!
+
 	echo launch vfd_swmr_bigset_writer many small, options $options
 	catch_out_err_and_rc vfd_swmr_bigset_writer \
 	    ../vfd_swmr_bigset_writer -n $BIGSET_n $options -s $BIGSET_many_s -e 1 -r 16 -c 16 -q &
@@ -1107,10 +1116,17 @@ for options in "-d 1" "-d 1 -F" "-d 2 -l 16" "-d 2 -F -l 16" "-d 1 -t" "-d 1 -t
 	# Wait for the reader to finish before signalling the
 	# writer to quit: the writer holds the file open so that the
 	# reader will find the shadow file when it opens
-	# the .h5 file.
+	# the .h5 file. Also wait for the auxiliary process to finish.
+        wait $pid_aux_proc
 	wait $pid_reader
 	wait $pid_writer
 
+	# Collect exit code of the auxiliary process
+	if [ $(cat aux_process.rc) -ne 0 ]; then
+		echo the auxiliary process had error
+		nerrors=$((nerrors + 1))
+	fi
+
 	# Collect exit code of the reader
 	if [ $(cat vfd_swmr_bigset_reader.rc) -ne 0 ]; then
 		echo reader had error
@@ -1126,6 +1142,8 @@ for options in "-d 1" "-d 1 -F" "-d 2 -l 16" "-d 2 -F -l 16" "-d 1 -t" "-d 1 -t
 	# Clean up output files
 	rm -f vfd_swmr_bigset_writer.{out,rc}
 	rm -f vfd_swmr_bigset_reader.*.{out,rc}
+        rm -f aux_process.{out,rc}
+        rm -f mdfile bigset_updater.* bigset-shadow-*
 done
 
 # bigset test for bigger chunks
@@ -1149,6 +1167,17 @@ for options in "-d 1" "-d 1 -F" "-d 2 -l 10" "-d 2 -F -l 10" "-d 1 -t -l 10" "-d
 		continue
 	fi
 	echo launch vfd_swmr_bigset_writer few big, options $options ......may take some time......
+
+        # Launch the auxiliary process for testing NFS if the --enable-aux-process option is enabled for configuration.
+        # If it isn't enabled, the auxiliary process simply exit without executing any code.  For the testing case of
+        # VDS across multiple files (-M option), the program also skips for future support.
+        if [[ $options == *"-M"* ]]; then
+	    catch_out_err_and_rc aux_process ../../utils/vfd_swmr/aux_process -a mdfile bigset_updater &
+        else
+	    catch_out_err_and_rc aux_process ../../utils/vfd_swmr/aux_process mdfile bigset_updater &
+        fi
+        pid_aux_proc=$!
+
 	catch_out_err_and_rc vfd_swmr_bigset_writer \
 	    ../vfd_swmr_bigset_writer -n $BIGSET_n $options -s $BIGSET_few_s -e 8 -r 256 -c 256 -q &
 	pid_writer=$!
@@ -1160,10 +1189,17 @@ for options in "-d 1" "-d 1 -F" "-d 2 -l 10" "-d 2 -F -l 10" "-d 1 -t -l 10" "-d
 	# Wait for the reader to finish before signalling the
 	# writer to quit: the writer holds the file open so that the
 	# reader will find the shadow file when it opens
-	# the .h5 file.
+	# the .h5 file. Also wait for the auxiliary process to finish.
+        wait $pid_aux_proc
 	wait $pid_reader
 	wait $pid_writer
 
+	# Collect exit code of the auxiliary process
+	if [ $(cat aux_process.rc) -ne 0 ]; then
+		echo the auxiliary process had error
+		nerrors=$((nerrors + 1))
+	fi
+
 	# Collect exit code of the reader
 	if [ $(cat vfd_swmr_bigset_reader.rc) -ne 0 ]; then
 		echo reader had error
@@ -1179,6 +1215,8 @@ for options in "-d 1" "-d 1 -F" "-d 2 -l 10" "-d 2 -F -l 10" "-d 1 -t -l 10" "-d
 	# Clean up output files
 	rm -f vfd_swmr_bigset_writer.{out,rc}
 	rm -f vfd_swmr_bigset_reader.*.{out,rc}
+        rm -f aux_process.{out,rc}
+        rm -f mdfile bigset_updater.* bigset-shadow-*
 done
 
 ###############################################################################
@@ -1313,6 +1351,70 @@ done
 
 ###############################################################################
 #
+# "dsetops_ref" test (this is the dsetops test with options added for testing references)
+# --test object (-O) and region (-R) references
+# --test with raw data flush only
+# --test without flush will result in error because the references are not there 
+#   to continue further testing
+#
+# Only for exhaustive run
+#
+###############################################################################
+#
+#
+# Loop with 
+for ref in "-O" "-R" "-O -R"; do
+    # Loop with different operations
+    for options in "-p -e 20 -t -g -q" "-g -m 5 -n 2 -s 10 -w 7 -q" "-k -m 10 -n 5 -r 5 -l 10 -q"; do
+	    #
+	    #
+	    if [ ${do_dsetops_ref:-no} = no ]; then
+		    continue
+	    fi
+        # Clean up any existing fifo files from previous runs
+        if [ -e ./$DSETOPS_FIFO_WRITER_TO_READER ]; then     # If writer fifo file is found
+            rm -f ./$DSETOPS_FIFO_WRITER_TO_READER
+        fi
+        if [ -e ./$DSETOPS_FIFO_READER_TO_WRITER ]; then      # If reader fifo file is found
+            rm -f ./$DSETOPS_FIFO_READER_TO_WRITER
+        fi
+        #
+	    echo launch vfd_swmr_dsetops_writer dsetops, options $options $ref......may take some time......
+	    catch_out_err_and_rc vfd_swmr_dsetops_writer \
+	        ../vfd_swmr_dsetops_writer $options $ref &
+	    pid_writer=$!
+
+	    catch_out_err_and_rc vfd_swmr_dsetops_reader \
+	        ../vfd_swmr_dsetops_reader $options $ref &
+	    pid_reader=$!
+
+	    # Wait for the reader to finish before signaling the
+	    # writer to quit: the writer holds the file open so that the
+	    # reader will find the shadow file when it opens
+	    # the .h5 file.
+	    wait $pid_reader
+	    wait $pid_writer
+
+	    # Collect exit code of the reader
+	    if [ $(cat vfd_swmr_dsetops_reader.rc) -ne 0 ]; then
+		    echo reader had error
+		    nerrors=$((nerrors + 1))
+	    fi
+
+	    # Collect exit code of the writer
+	    if [ $(cat vfd_swmr_dsetops_writer.rc) -ne 0 ]; then
+	        echo writer had error
+	        nerrors=$((nerrors + 1))
+	    fi
+
+	    # Clean up output files
+	    rm -f vfd_swmr_dsetops_writer.{out,rc}
+	    rm -f vfd_swmr_dsetops_reader.*.{out,rc}
+    done
+done
+
+###############################################################################
+#
 # "dsetchks" test
 #
 # Only for exhaustive run
diff --git a/test/vfd_swmr.c b/test/vfd_swmr.c
index 630b25d..902ce7f 100644
--- a/test/vfd_swmr.c
+++ b/test/vfd_swmr.c
@@ -1,5 +1,6 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
  * Copyright by The HDF Group.                                               *
+ * Copyright by Akadio, Inc.                                                 *
  * All rights reserved.                                                      *
  *                                                                           *
  * This file is part of HDF5.  The full HDF5 copyright notice, including     *
diff --git a/test/vfd_swmr_addrem_writer.c b/test/vfd_swmr_addrem_writer.c
index ddf3f9c..4cfdeb2 100644
--- a/test/vfd_swmr_addrem_writer.c
+++ b/test/vfd_swmr_addrem_writer.c
@@ -1,5 +1,6 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
  * Copyright by The HDF Group.                                               *
+ * Copyright by Akadio, Inc.                                                 *
  * All rights reserved.                                                      *
  *                                                                           *
  * This file is part of HDF5.  The full HDF5 copyright notice, including     *
diff --git a/test/vfd_swmr_attrdset_writer.c b/test/vfd_swmr_attrdset_writer.c
index a722f44..1037108 100644
--- a/test/vfd_swmr_attrdset_writer.c
+++ b/test/vfd_swmr_attrdset_writer.c
@@ -1,15 +1,15 @@
-/*
- * Copyright by The HDF Group.
- * Copyright by the Board of Trustees of the University of Illinois.
- * All rights reserved.
- *
- * This file is part of HDF5.  The full HDF5 copyright notice, including
- * terms governing use, modification, and redistribution, is contained in
- * the COPYING file, which can be found at the root of the source code
- * distribution tree, or in https://support.hdfgroup.org/ftp/HDF5/releases.
- * If you do not have access to either file, you may request a copy from
- * help@hdfgroup.org.
- */
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by The HDF Group.                                               *
+ * Copyright by Akadio, Inc.                                                 *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5.  The full HDF5 copyright notice, including     *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the COPYING file, which can be found at the root of the source code       *
+ * distribution tree, or in https://www.hdfgroup.org/licenses.               *
+ * If you do not have access to either file, you may request a copy from     *
+ * help@hdfgroup.org.                                                        *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
 /*
  *  Purpose: To test attribute handling for different dataset types.
diff --git a/test/vfd_swmr_bigset_writer.c b/test/vfd_swmr_bigset_writer.c
index 14cbedf..79a571e 100644
--- a/test/vfd_swmr_bigset_writer.c
+++ b/test/vfd_swmr_bigset_writer.c
@@ -1,5 +1,6 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
  * Copyright by The HDF Group.                                               *
+ * Copyright by Akadio, Inc.                                                 *
  * All rights reserved.                                                      *
  *                                                                           *
  * This file is part of HDF5.  The full HDF5 copyright notice, including     *
@@ -151,6 +152,7 @@ typedef struct {
     bool            use_vfd_swmr;
     bool            use_legacy_swmr;
     bool            use_named_pipe;
+    bool            use_aux_proc;
     bool            do_perf;
     bool            cross_chunk_read;
     bool            writer;
@@ -217,6 +219,7 @@ state_initializer(void)
                      .use_vfd_swmr     = true,
                      .use_legacy_swmr  = false,
                      .use_named_pipe   = true,
+                     .use_aux_proc     = false,
                      .do_perf          = false,
                      .cross_chunk_read = false,
                      .writer           = true,
@@ -245,11 +248,12 @@ usage(const char *progname)
 {
     HDfprintf(
         stderr,
-        "usage: %s [-C] [-F] [-M] [-P] [-R] [-S] [-V] [-W] [-a steps] [-b] [-c cols]\n"
+        "usage: %s [-A] [-C] [-F] [-M] [-P] [-R] [-S] [-V] [-W] [-a steps] [-b] [-c cols]\n"
         "    [-d dims] [-e depth] [-f tick_len] [-g max_lag] [-j skip_chunk] [-k part_chunk]\n"
         "    [-l tick_num] [-n iterations] [-o page_buf_size] [-p fsp_size] [-r rows]\n"
         "    [-s datasets] [-t] [-u over_extend] [-v chunk_cache_size] [-w deflate_level]\n"
         "\n"
+        "-A:                   use the auxiliary process to update the metadata file\n"
         "-C:                   cross-over chunk read during chunk verification\n"
         "-F:                   fixed maximal dimension for the chunked datasets\n"
         "-M:	               use virtual datasets and many source\n"
@@ -342,8 +346,11 @@ state_init(state_t *s, int argc, char **argv)
     if (tfile)
         HDfree(tfile);
 
-    while ((ch = getopt(argc, argv, "CFMNPRSTVa:bc:d:e:f:g:j:k:l:m:n:o:p:qr:s:tu:v:w:")) != -1) {
+    while ((ch = getopt(argc, argv, "ACFMNPRSTVa:bc:d:e:f:g:j:k:l:m:n:o:p:qr:s:tu:v:w:")) != -1) {
         switch (ch) {
+            case 'A':
+                s->use_aux_proc = true;
+                break;
             case 'C':
                 /* This flag indicates cross-over chunk read during data validation */
                 s->cross_chunk_read = true;
@@ -488,6 +495,11 @@ state_init(state_t *s, int argc, char **argv)
         TEST_ERROR;
     }
 
+#ifdef H5_HAVE_AUX_PROCESS
+    if (s->vds == vds_multi)
+        exit(EXIT_SUCCESS);
+#endif
+
     if (s->vds != vds_off && s->expand_2d) {
         HDfprintf(stderr, "virtual datasets and 2D datasets are mutually exclusive\n");
         TEST_ERROR;
@@ -1148,6 +1160,101 @@ error:
     return -1;
 }
 
+/*-------------------------------------------------------------------------
+ * Function:    md_ck_cb()
+ *
+ * Purpose:     This is the callback function for debugging only.  It's used
+ *              when the H5F_ACS_GENERATE_MD_CK_CB_NAME property is set in fapl.
+ *                  --Opens and read the metadata file into a buffer.
+ *                  --Generate checksum for the metadata file
+ *                  --Write the tick number and the checksum to the checksum file
+ *
+ * Return:      0 if test is sucessful
+ *              1 if test fails
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+md_ck_cb(char *md_file_path, uint64_t updater_seq_num)
+{
+    FILE *   md_fp  = NULL;      /* Metadata file pointer */
+    FILE *   chk_fp = NULL;      /* Checksum file pointer */
+    long     size   = 0;         /* File size returned from HDftell() */
+    void *   buf    = NULL;      /* Buffer for holding the metadata file content */
+    uint32_t chksum = 0;         /* The checksum generated for the metadata file */
+    char     chk_name[1024 + 4]; /* Buffer for the checksum file name */
+    size_t   ret;                /* Return value */
+
+    /* Open the metadata file */
+    if ((md_fp = HDfopen(md_file_path, "r")) == NULL)
+        FAIL_STACK_ERROR;
+
+    /* Set file pointer at end of file.*/
+    if (HDfseek(md_fp, 0, SEEK_END) < 0)
+        FAIL_STACK_ERROR;
+
+    /* Get the current position of the file pointer.*/
+    if ((size = HDftell(md_fp)) < 0)
+        FAIL_STACK_ERROR;
+
+    if (size != 0) {
+
+        HDrewind(md_fp);
+
+        if ((buf = HDmalloc((size_t)size)) == NULL)
+            FAIL_STACK_ERROR;
+
+        /* Read the metadata file to buf */
+        if ((ret = HDfread(buf, 1, (size_t)size, md_fp)) != (size_t)size)
+            FAIL_STACK_ERROR;
+
+        /* Calculate checksum of the metadata file */
+        chksum = H5_checksum_metadata(buf, (size_t)size, 0);
+    }
+
+    /* Close the metadata file */
+    if (md_fp && HDfclose(md_fp) < 0)
+        FAIL_STACK_ERROR;
+
+    /*
+     *  Checksum file
+     */
+
+    /* Generate checksum file name: <md_file_path>.chk */
+    HDsprintf(chk_name, "%s.chk", md_file_path);
+
+    /* Open checksum file for append */
+    if ((chk_fp = HDfopen(chk_name, "a")) == NULL)
+        FAIL_STACK_ERROR;
+
+    /* Write the updater sequence number to the checksum file */
+    if ((ret = HDfwrite(&updater_seq_num, sizeof(uint64_t), 1, chk_fp)) != 1)
+        FAIL_STACK_ERROR;
+
+    /* Write the checksum to the checksum file */
+    if ((ret = HDfwrite(&chksum, sizeof(uint32_t), 1, chk_fp)) != 1)
+        FAIL_STACK_ERROR;
+
+    /* Close the checksum file */
+    if (chk_fp && HDfclose(chk_fp) != 0)
+        FAIL_STACK_ERROR;
+
+    if (buf)
+        HDfree(buf);
+
+    return 0;
+
+error:
+    if (buf)
+        HDfree(buf);
+    if (md_fp)
+        HDfclose(md_fp);
+    if (chk_fp)
+        HDfclose(chk_fp);
+
+    return -1;
+} /* md_ck_cb() */
+
 static bool
 create_extensible_dset(state_t *s, unsigned int which)
 {
@@ -2437,12 +2544,13 @@ error:
 int
 main(int argc, char **argv)
 {
-    mat_t *    mat;
-    hid_t      fcpl = H5I_INVALID_HID;
-    unsigned   which;
-    state_t    s;
-    np_state_t np;
-    size_t     i;
+    mat_t *                 mat;
+    hid_t                   fcpl = H5I_INVALID_HID;
+    unsigned                which;
+    state_t                 s;
+    np_state_t              np;
+    size_t                  i;
+    H5F_generate_md_ck_cb_t cb_info; /* Callback */
 
     if (!state_init(&s, argc, argv)) {
         HDfprintf(stderr, "state_init failed\n");
@@ -2472,8 +2580,21 @@ main(int argc, char **argv)
 
         /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
          * flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
+#ifdef H5_HAVE_AUX_PROCESS
+        /* If using the auxiliary process, the writer creates the updater files.
+         * The reader uses the metadata file generated by the auxiliary process. */
+        if (s.writer) {
+            init_vfd_swmr_config(&config, s.tick_len, s.max_lag, s.writer, FALSE, TRUE, s.flush_raw_data, 128,
+                                 "./bigset-shadow-%zu", "bigset_updater", i);
+        }
+        else {
+            init_vfd_swmr_config(&config, s.tick_len, s.max_lag, s.writer, TRUE, FALSE, s.flush_raw_data, 128,
+                                 "./mdfile", NULL);
+        }
+#else
         init_vfd_swmr_config(&config, s.tick_len, s.max_lag, s.writer, TRUE, FALSE, s.flush_raw_data, 128,
                              "./bigset-shadow-%zu", NULL, i);
+#endif
 
         /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
         if ((fapl = vfd_swmr_create_fapl(true, s.use_vfd_swmr, true, s.page_buf_size, &config)) < 0) {
@@ -2502,6 +2623,17 @@ main(int argc, char **argv)
             }
         }
 
+        /* This part is for debugging only */
+#ifdef TMP
+        {
+            /* Set up callback to generate checksums for updater's metadata files */
+            cb_info.func = md_ck_cb;
+
+            /* Activate private property to generate checksums for updater's metadata file */
+            H5Pset(fapl, H5F_ACS_GENERATE_MD_CK_CB_NAME, &cb_info);
+        }
+#endif
+
         s.file[i] = s.writer ? H5Fcreate(s.filename[i], H5F_ACC_TRUNC, fcpl, fapl)
                              : H5Fopen(s.filename[i], H5F_ACC_RDONLY, fapl);
 
diff --git a/test/vfd_swmr_check_compat.c b/test/vfd_swmr_check_compat.c
index dec88c5..edf37a2 100644
--- a/test/vfd_swmr_check_compat.c
+++ b/test/vfd_swmr_check_compat.c
@@ -1,6 +1,6 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
  * Copyright by The HDF Group.                                               *
- * Copyright by the Board of Trustees of the University of Illinois.         *
+ * Copyright by Akadio, Inc.                                                 *
  * All rights reserved.                                                      *
  *                                                                           *
  * This file is part of HDF5.  The full HDF5 copyright notice, including     *
diff --git a/test/vfd_swmr_common.c b/test/vfd_swmr_common.c
index 9b711dd..99db307 100644
--- a/test/vfd_swmr_common.c
+++ b/test/vfd_swmr_common.c
@@ -1,5 +1,6 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
  * Copyright by The HDF Group.                                               *
+ * Copyright by Akadio, Inc.                                                 *
  * All rights reserved.                                                      *
  *                                                                           *
  * This file is part of HDF5.  The full HDF5 copyright notice, including     *
diff --git a/test/vfd_swmr_common.h b/test/vfd_swmr_common.h
index b842fe7..9f99c6e 100644
--- a/test/vfd_swmr_common.h
+++ b/test/vfd_swmr_common.h
@@ -1,5 +1,6 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
  * Copyright by The HDF Group.                                               *
+ * Copyright by Akadio, Inc.                                                 *
  * All rights reserved.                                                      *
  *                                                                           *
  * This file is part of HDF5.  The full HDF5 copyright notice, including     *
diff --git a/test/vfd_swmr_dsetchks_writer.c b/test/vfd_swmr_dsetchks_writer.c
index c09c825..f2bd29b 100644
--- a/test/vfd_swmr_dsetchks_writer.c
+++ b/test/vfd_swmr_dsetchks_writer.c
@@ -1,15 +1,15 @@
-/*
- * Copyright by The HDF Group.
- * Copyright by the Board of Trustees of the University of Illinois.
- * All rights reserved.
- *
- * This file is part of HDF5.  The full HDF5 copyright notice, including
- * terms governing use, modification, and redistribution, is contained in
- * the COPYING file, which can be found at the root of the source code
- * distribution tree, or in https://support.hdfgroup.org/ftp/HDF5/releases.
- * If you do not have access to either file, you may request a copy from
- * help@hdfgroup.org.
- */
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by The HDF Group.                                               *
+ * Copyright by Akadio, Inc.                                                 *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5.  The full HDF5 copyright notice, including     *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the COPYING file, which can be found at the root of the source code       *
+ * distribution tree, or in https://www.hdfgroup.org/licenses.               *
+ * If you do not have access to either file, you may request a copy from     *
+ * help@hdfgroup.org.                                                        *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
 /*
  *  Purpose: To test chunk operations for chunked dataset specifically:
diff --git a/test/vfd_swmr_dsetops_writer.c b/test/vfd_swmr_dsetops_writer.c
index d999d64..d7ef255 100644
--- a/test/vfd_swmr_dsetops_writer.c
+++ b/test/vfd_swmr_dsetops_writer.c
@@ -1,15 +1,15 @@
-/*
- * Copyright by The HDF Group.
- * Copyright by the Board of Trustees of the University of Illinois.
- * All rights reserved.
- *
- * This file is part of HDF5.  The full HDF5 copyright notice, including
- * terms governing use, modification, and redistribution, is contained in
- * the COPYING file, which can be found at the root of the source code
- * distribution tree, or in https://support.hdfgroup.org/ftp/HDF5/releases.
- * If you do not have access to either file, you may request a copy from
- * help@hdfgroup.org.
- */
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by The HDF Group.                                               *
+ * Copyright by Akadio, Inc.                                                 *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5.  The full HDF5 copyright notice, including     *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the COPYING file, which can be found at the root of the source code       *
+ * distribution tree, or in https://www.hdfgroup.org/licenses.               *
+ * If you do not have access to either file, you may request a copy from     *
+ * help@hdfgroup.org.                                                        *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
 /*
  *  Purpose: To test writing operations for different dataset types.
@@ -24,6 +24,35 @@
  *      -- Regular hyperslab writes
  *      -- Raw data modifications
  */
+/*
+ * Modifications for testing references
+ *
+ *  -O option for object reference
+ *      --Writer:
+ *          When creating the datasets via create_dsets():
+ *              --Create an object reference dataset
+ *              --Store the dataset references via H5Rcreate_object() and save
+ *                them in the object reference dataset
+ *      --Reader:
+ *          When opening the datasets via open_dsets():
+ *              --Open the object reference dataset
+ *              --Retrieve the object references from the dataset
+ *              --Open the dataset object via H5Ropen_object()
+ *
+ *  -R option for region reference
+ *      Writer:
+ *          --When creating the datasets via create_dsets():
+ *              --Create a region reference dataset
+ *          --When writing to the datasets via write_dset():
+ *              --Store the dataset selections via H5Rcreate_region() and save
+ *                them in the region reference dataset
+ *      Reader:
+ *          --When opening the datasets via open_dsets():
+ *              --Open the region reference dataset
+ *          --When verifying data written to a dataset via verify_dset():
+ *              --Retrieve the dataset selections from the region reference dataset
+ *              --Get the selection via H5Ropen_region()
+ */
 
 #include "hdf5.h"
 #include "testhdf5.h"
@@ -47,6 +76,8 @@ typedef struct {
     bool         use_np;             /* For -N option */
     bool         use_vfd_swmr;       /* For -S option */
     bool         flush_raw_data;     /* For -U option */
+    bool         obj_ref;            /* For -O option */
+    bool         reg_ref;            /* For -R option */
     bool         compact;            /* -p option: create compact dataset */
     bool         compact_write;      /* -t option: write to the whole compact dataset */
     unsigned int compact_elmts;      /* -e <elmts> option: # of elments for the compact dataset */
@@ -69,25 +100,28 @@ typedef struct {
         .update_interval = READER_WAIT_TICKS, .csteps = 1, .use_np = true, .use_vfd_swmr = true,             \
         .flush_raw_data = true, .compact = false, .compact_write = false, .compact_elmts = MAX_COMPACT_ELMS, \
         .contig = false, .rows = 10, .cols = 5, .swrites = 0, .rwrites = 0, .lwrites = 0, .wwrites = 0,      \
-        .lastwrite = 0                                                                                       \
+        .lastwrite = 0, .obj_ref = false, .reg_ref = false                                                   \
     }
 
 /* Structure to hold info for different dataset types */
 typedef struct {
-    hid_t compact_did;  /* ID for compact dataset */
-    hid_t contig_did;   /* ID for contiguous dataset */
-    hid_t single_did;   /* ID for chunked dataset: single index */
-    hid_t implicit_did; /* ID for chunked dataset: implicit index */
-    hid_t fa_did;       /* ID for chunked dataset: fixed array index  */
-    hid_t ea_did;       /* ID for chunked dataset: extensible array index */
-    hid_t bt2_did;      /* ID for chunked dataset: version 2 btree index */
-    hid_t compact_sid;  /* Dataspace ID for compact dataset */
-    hid_t contig_sid;   /* Dataspace ID for contiguous dataset */
-    hid_t single_sid;   /* Dataspace ID for chunked dataset */
-    hid_t implicit_sid; /* Dataspace ID for chunked dataset */
-    hid_t fa_sid;       /* Dataspace ID for chunked dataset */
-    hid_t ea_sid;       /* Dataspace ID for chunked dataset */
-    hid_t bt2_sid;      /* Dataspace ID for chunked dataset */
+    hid_t      compact_did;  /* ID for compact dataset */
+    hid_t      contig_did;   /* ID for contiguous dataset */
+    hid_t      single_did;   /* ID for chunked dataset: single index */
+    hid_t      implicit_did; /* ID for chunked dataset: implicit index */
+    hid_t      fa_did;       /* ID for chunked dataset: fixed array index  */
+    hid_t      ea_did;       /* ID for chunked dataset: extensible array index */
+    hid_t      bt2_did;      /* ID for chunked dataset: version 2 btree index */
+    hid_t      compact_sid;  /* Dataspace ID for compact dataset */
+    hid_t      contig_sid;   /* Dataspace ID for contiguous dataset */
+    hid_t      single_sid;   /* Dataspace ID for chunked dataset */
+    hid_t      implicit_sid; /* Dataspace ID for chunked dataset */
+    hid_t      fa_sid;       /* Dataspace ID for chunked dataset */
+    hid_t      ea_sid;       /* Dataspace ID for chunked dataset */
+    hid_t      bt2_sid;      /* Dataspace ID for chunked dataset */
+    hid_t      obj_did;      /* ID for object reference dataset */
+    hid_t      reg_did;      /* ID for region reference dataset */
+    H5R_ref_t *reg_buf;      /* Buffer for holding the region references */
 } dsets_state_t;
 
 /* Initializations for dsets_state_t */
@@ -98,7 +132,8 @@ typedef struct {
         .contig_sid = H5I_INVALID_HID, .single_did = H5I_INVALID_HID, .single_sid = H5I_INVALID_HID,         \
         .implicit_did = H5I_INVALID_HID, .implicit_sid = H5I_INVALID_HID, .fa_did = H5I_INVALID_HID,         \
         .fa_sid = H5I_INVALID_HID, .ea_did = H5I_INVALID_HID, .ea_sid = H5I_INVALID_HID,                     \
-        .bt2_did = H5I_INVALID_HID, .bt2_sid = H5I_INVALID_HID                                               \
+        .bt2_did = H5I_INVALID_HID, .bt2_sid = H5I_INVALID_HID, .obj_did = H5I_INVALID_HID,                  \
+        .reg_did = H5I_INVALID_HID, .reg_buf = NULL                                                          \
     }
 
 /* Structure to hold info for named pipes */
@@ -131,8 +166,8 @@ static bool np_confirm_verify_notify(int fd, unsigned step, const state_t *s, np
 
 static bool create_dsets(const state_t *s, dsets_state_t *ds);
 static bool open_dsets(const state_t *s, dsets_state_t *ds);
-static bool open_dset_real(const state_t *s, hid_t *did, hid_t *sid, const char *name);
-static bool close_dsets(const dsets_state_t *ds);
+static bool open_dset_real(const state_t *s, hid_t *did, hid_t *sid, const char *name, H5R_ref_t *obj_buf);
+static bool close_dsets(dsets_state_t *ds);
 static bool close_dset_real(hid_t did, hid_t sid);
 
 static bool perform_dsets_operations(state_t *s, dsets_state_t *ds, H5F_vfd_swmr_config_t *config,
@@ -140,17 +175,18 @@ static bool perform_dsets_operations(state_t *s, dsets_state_t *ds, H5F_vfd_swmr
 static bool dsets_action(unsigned action, const state_t *s, const dsets_state_t *ds, unsigned step);
 static bool dset_setup(unsigned action, unsigned which, const state_t *s, hsize_t *start, hsize_t *stride,
                        hsize_t *count, hsize_t *block, hid_t *mem_sid, unsigned int **buf);
-static bool write_dset(hid_t did, hid_t tid, hid_t mem_sid, hid_t file_sid, hsize_t *start, hsize_t *stride,
-                       hsize_t *count, hsize_t *block, unsigned int *buf);
+static bool write_dset(const state_t *s, const char *name, hid_t did, hid_t sid, hid_t mem_sid,
+                       hsize_t *start, hsize_t *stride, hsize_t *count, hsize_t *block, unsigned int *buf,
+                       H5R_ref_t *reg_buf);
 static bool write_dset_compact(const state_t *s, const dsets_state_t *ds);
 
 static bool verify_dsets_operations(state_t *s, dsets_state_t *ds, H5F_vfd_swmr_config_t *config,
                                     np_state_t *np, bool fileclosed);
 static bool verify_dsets_action(unsigned action, const state_t *s, const dsets_state_t *ds, unsigned which,
                                 bool fileclosed);
-static bool verify_dset(hid_t did, hid_t tid, hid_t mem_sid, hid_t file_sid, hsize_t *start, hsize_t *stride,
+static bool verify_dset(hid_t did, hid_t tid, hid_t sid, hid_t mem_sid, hsize_t *start, hsize_t *stride,
                         hsize_t *count, hsize_t *block, unsigned int *vbuf, bool fileclosed,
-                        bool flush_raw_data);
+                        bool flush_raw_data, H5R_ref_t *rbuf);
 static bool verify_dset_compact(const state_t *s, const dsets_state_t *ds, bool fileclosed,
                                 bool flush_raw_data);
 
@@ -168,6 +204,11 @@ static const hid_t badhid = H5I_INVALID_HID;
 #define DSET_EA_NAME       "chunked_ea"
 #define DSET_BT2_NAME      "chunked_bt2"
 
+#define DSET_OBJ_REF_NAME "obj_ref_dset" /* Object reference dataset */
+#define DSET_REG_REF_NAME "reg_ref_dset" /* Region reference dataset */
+#define OBJ_REF_DIMS      7              /* Dimension size for object reference dataset */
+#define REG_REF_DIMS      6              /* Dimension size for region reference dataset */
+
 /* Action for writes */
 #define SEQ_WRITE    1 /* Sequential write */
 #define RANDOM_WRITE 2 /* Random write */
@@ -183,7 +224,7 @@ usage(const char *progname)
               "           [-p] [-e elmts] [-o]\n"
               "           [-g] [-k] [-m rows] [-n cols]\n"
               "           [-s swrites] [-r rwrites] [-l lwrites] [-w writes]\n"
-              "           [-u nticks] [-c csteps] [-U] [-S] [-N] [-q] [-b]\n"
+              "           [-u nticks] [-c csteps] [-U] [-O] [-R] [-S] [-N] [-q] [-b]\n"
               "\n"
               "-p:              create a dataset with compact layout\n"
               "-e elmts:        # of <elmts> for the compact dataset\n"
@@ -203,6 +244,8 @@ usage(const char *progname)
               "-c csteps:       `csteps` steps communication interval between reader and writer\n"
               "                 (default is 1)\n"
               "-U:              disable flush of raw data (default is flushing raw data)\n"
+              "-O:              create object references to datasets\n"
+              "-R:              create region references to datasets\n"
               "-S:              do not use VFD SWMR\n"
               "-N:              do not use named pipes for test synchronization\n"
               "-q:              silence printouts, few messages\n"
@@ -242,7 +285,7 @@ state_init(state_t *s, int argc, char **argv)
         tfile = NULL;
     }
 
-    while ((ch = getopt(argc, argv, "pte:gkm:n:s:r:l:w:bqSNUu:c:")) != -1) {
+    while ((ch = getopt(argc, argv, "pte:gkm:n:s:r:l:w:bqSNUORu:c:")) != -1) {
         switch (ch) {
 
             case 'p': /* compact dataset */
@@ -265,6 +308,14 @@ state_init(state_t *s, int argc, char **argv)
                 s->flush_raw_data = false;
                 break;
 
+            case 'O': /* Create object reference to datasets */
+                s->obj_ref = true;
+                break;
+
+            case 'R': /* Create region reference to datasets */
+                s->reg_ref = true;
+                break;
+
             case 'q':
                 verbosity = 0;
                 break;
@@ -355,6 +406,20 @@ state_init(state_t *s, int argc, char **argv)
         goto error;
     }
 
+    /* Object reference applies to either compact or contiguous or chunked datasets */
+    if (s->obj_ref && !(s->compact || s->contig || s->chunked)) {
+        HDprintf("Enable object reference without compact/contig/chunked dataset\n");
+        usage(s->progname);
+        goto error;
+    }
+
+    /* Region reference applies to either contiguous or chunked datasets */
+    if (s->reg_ref && !(s->contig || s->chunked)) {
+        HDprintf("Enable region reference without contig/chunked dataset\n");
+        usage(s->progname);
+        goto error;
+    }
+
     /* Enable sequential/random/hyperslab/raw data writes (-s/-r/-l/-w) without contiguous/chunked dataset
      * (-g/-k) */
     if ((s->swrites || s->rwrites || s->lwrites || s->wwrites) && !(s->contig || s->chunked)) {
@@ -412,12 +477,17 @@ error:
 static bool
 create_dsets(const state_t *s, dsets_state_t *ds)
 {
-    hid_t dcpl = badhid;
-    hid_t dtid = badhid;
+    hid_t      dcpl = badhid;
+    hid_t      dtid = badhid;
+    unsigned   i;
+    H5R_ref_t *obj_buf  = NULL; /* Buffer for object references */
+    hid_t      sid      = badhid;
+    hsize_t    obj_dims = OBJ_REF_DIMS; /* Dimension for object reference dataset */
+    hsize_t    reg_dims = REG_REF_DIMS; /* Dimension for region reference dataset */
 
     *ds = DSETS_INITIALIZER;
 
-    /* Create the named datatype that will be used by compact and contiguous datasets */
+    /* Create the named datatype that will be used by compact dataset */
     if ((dtid = H5Tcopy(s->filetype)) < 0) {
         HDprintf("H5Tcopy failed\n");
         TEST_ERROR;
@@ -462,7 +532,7 @@ create_dsets(const state_t *s, dsets_state_t *ds)
         }
     }
 
-    /* Dataset with contiguous layout, 2d, named datatype */
+    /* Dataset with contiguous layout, 2d */
     if (s->contig) {
         hsize_t dims[2];
 
@@ -485,9 +555,9 @@ create_dsets(const state_t *s, dsets_state_t *ds)
             TEST_ERROR;
         }
 
-        /* Create the contiguous dataset with the named datatype */
-        if ((ds->contig_did = H5Dcreate2(s->file, DSET_CONTIG_NAME, dtid, ds->contig_sid, H5P_DEFAULT, dcpl,
-                                         H5P_DEFAULT)) < 0) {
+        /* Create the contiguous dataset with DEFAULT datatype */
+        if ((ds->contig_did = H5Dcreate2(s->file, DSET_CONTIG_NAME, s->filetype, ds->contig_sid, H5P_DEFAULT,
+                                         dcpl, H5P_DEFAULT)) < 0) {
             HDprintf("H5Dcreate2 contiguous dataset failed\n");
             TEST_ERROR;
         }
@@ -498,7 +568,7 @@ create_dsets(const state_t *s, dsets_state_t *ds)
         }
     }
 
-    /* Dataset with chunked layout, 2d, named datatype */
+    /* Dataset with chunked layout, 2d */
     if (s->chunked) {
         hsize_t dims[2];
         hsize_t max_dims[2];
@@ -534,9 +604,9 @@ create_dsets(const state_t *s, dsets_state_t *ds)
             TEST_ERROR;
         }
 
-        /* Create the chunked dataset (single index) with the named datatype */
-        if ((ds->single_did = H5Dcreate2(s->file, DSET_SINGLE_NAME, dtid, ds->single_sid, H5P_DEFAULT, dcpl,
-                                         H5P_DEFAULT)) < 0) {
+        /* Create the chunked dataset (single index) with the default datatype */
+        if ((ds->single_did = H5Dcreate2(s->file, DSET_SINGLE_NAME, s->filetype, ds->single_sid, H5P_DEFAULT,
+                                         dcpl, H5P_DEFAULT)) < 0) {
             HDprintf("H5Dcreate2 chunked dataset:single index failed\n");
             TEST_ERROR;
         }
@@ -559,9 +629,9 @@ create_dsets(const state_t *s, dsets_state_t *ds)
             TEST_ERROR;
         }
 
-        /* Create the chunked dataset (implicit index) with the named datatype */
-        if ((ds->implicit_did = H5Dcreate2(s->file, DSET_IMPLICIT_NAME, dtid, ds->implicit_sid, H5P_DEFAULT,
-                                           dcpl, H5P_DEFAULT)) < 0) {
+        /* Create the chunked dataset (implicit index) with the default datatype */
+        if ((ds->implicit_did = H5Dcreate2(s->file, DSET_IMPLICIT_NAME, s->filetype, ds->implicit_sid,
+                                           H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0) {
             HDprintf("H5Dcreate2 chunked dataset:implicit index failed\n");
             TEST_ERROR;
         }
@@ -592,9 +662,9 @@ create_dsets(const state_t *s, dsets_state_t *ds)
             TEST_ERROR;
         }
 
-        /* Create the chunked dataset (fixed array index) with the named datatype */
-        if ((ds->fa_did =
-                 H5Dcreate2(s->file, DSET_FA_NAME, dtid, ds->fa_sid, H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0) {
+        /* Create the chunked dataset (fixed array index) with the default datatype */
+        if ((ds->fa_did = H5Dcreate2(s->file, DSET_FA_NAME, s->filetype, ds->fa_sid, H5P_DEFAULT, dcpl,
+                                     H5P_DEFAULT)) < 0) {
             HDprintf("H5Dcreaet2 chunked dataset: fa index failed\n");
             TEST_ERROR;
         }
@@ -608,9 +678,9 @@ create_dsets(const state_t *s, dsets_state_t *ds)
             TEST_ERROR;
         }
 
-        /* Create the chunked dataset (extensible array index) with the named datatype */
-        if ((ds->ea_did =
-                 H5Dcreate2(s->file, DSET_EA_NAME, dtid, ds->ea_sid, H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0) {
+        /* Create the chunked dataset (extensible array index) with the default datatype */
+        if ((ds->ea_did = H5Dcreate2(s->file, DSET_EA_NAME, s->filetype, ds->ea_sid, H5P_DEFAULT, dcpl,
+                                     H5P_DEFAULT)) < 0) {
             HDprintf("H5Dcreate2 chunked dataset: ea index failed\n");
             TEST_ERROR;
         }
@@ -624,9 +694,9 @@ create_dsets(const state_t *s, dsets_state_t *ds)
             TEST_ERROR;
         }
 
-        /* Create the chunked dataset (btree2 index) with the named datatype */
-        if ((ds->bt2_did =
-                 H5Dcreate2(s->file, DSET_BT2_NAME, dtid, ds->bt2_sid, H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0) {
+        /* Create the chunked dataset (btree2 index) with the default datatype */
+        if ((ds->bt2_did = H5Dcreate2(s->file, DSET_BT2_NAME, s->filetype, ds->bt2_sid, H5P_DEFAULT, dcpl,
+                                      H5P_DEFAULT)) < 0) {
             HDprintf("H5Dcreate2 chunked dataset: bt2 index failed\n");
             TEST_ERROR;
         }
@@ -642,6 +712,104 @@ create_dsets(const state_t *s, dsets_state_t *ds)
         TEST_ERROR;
     }
 
+    /* If object reference is enabled: */
+    /* create the object reference dataset and the references to the dataset objects */
+    if (s->obj_ref) {
+        if ((obj_buf = HDcalloc(sizeof(H5R_ref_t), OBJ_REF_DIMS)) == NULL) {
+            HDprintf("HDcalloc failed\n");
+            TEST_ERROR;
+        }
+        if ((sid = H5Screate_simple(1, &obj_dims, NULL)) < 0) {
+            HDprintf("H5Screate_simple failed\n");
+            TEST_ERROR;
+        }
+        if ((ds->obj_did = H5Dcreate2(s->file, DSET_OBJ_REF_NAME, H5T_STD_REF, sid, H5P_DEFAULT, H5P_DEFAULT,
+                                      H5P_DEFAULT)) < 0) {
+            HDprintf("H5Dcreate2 object reference dataset failed\n");
+            TEST_ERROR;
+        }
+
+        if (s->compact)
+            if (H5Rcreate_object(s->file, DSET_COMPACT_NAME, H5P_DEFAULT, &obj_buf[0]) < 0) {
+                HDprintf("H5Rcreate_object failed\n");
+                TEST_ERROR;
+            }
+        if (s->contig)
+            if (H5Rcreate_object(s->file, DSET_CONTIG_NAME, H5P_DEFAULT, &obj_buf[1]) < 0) {
+                HDprintf("H5Rcreate_object failed\n");
+                TEST_ERROR;
+            }
+        if (s->chunked) {
+            if (H5Rcreate_object(s->file, DSET_SINGLE_NAME, H5P_DEFAULT, &obj_buf[2]) < 0) {
+                HDprintf("H5Rcreate_object failed\n");
+                TEST_ERROR;
+            }
+
+            if (H5Rcreate_object(s->file, DSET_IMPLICIT_NAME, H5P_DEFAULT, &obj_buf[3]) < 0) {
+                HDprintf("H5Rcreate_object failed\n");
+                TEST_ERROR;
+            }
+            if (H5Rcreate_object(s->file, DSET_FA_NAME, H5P_DEFAULT, &obj_buf[4]) < 0) {
+                HDprintf("H5Rcreate_object failed\n");
+                TEST_ERROR;
+            }
+            if (H5Rcreate_object(s->file, DSET_EA_NAME, H5P_DEFAULT, &obj_buf[5]) < 0) {
+                HDprintf("H5Rcreate_object failed\n");
+                TEST_ERROR;
+            }
+            if (H5Rcreate_object(s->file, DSET_BT2_NAME, H5P_DEFAULT, &obj_buf[6]) < 0) {
+                HDprintf("H5Rcreate_object failed\n");
+                TEST_ERROR;
+            }
+        }
+
+        /* Write the object references to the reference dataset */
+        if (H5Dwrite(ds->obj_did, H5T_STD_REF, H5S_ALL, H5S_ALL, H5P_DEFAULT, obj_buf) < 0) {
+            HDprintf("H5Dwrite object reference dataset failed\n");
+            TEST_ERROR;
+        }
+
+        /* Destroy the references */
+        for (i = 0; i < OBJ_REF_DIMS; i++)
+            if (H5Rdestroy(&obj_buf[i]) < 0) {
+                HDprintf("H5Rdestroy object reference failed\n");
+                TEST_ERROR;
+            }
+
+        if (H5Sclose(sid) < 0) {
+            HDprintf("H5Sclose \n");
+            TEST_ERROR;
+        }
+
+        if (obj_buf)
+            HDfree(obj_buf);
+    }
+
+    /* If region reference is enabled: */
+    /* create the region reference dataset and allocate the buffer for holding the references */
+    if (s->reg_ref) {
+        if ((sid = H5Screate_simple(1, &reg_dims, NULL)) < 0) {
+            HDprintf("H5Screate_simple failed\n");
+            TEST_ERROR;
+        }
+
+        if ((ds->reg_did = H5Dcreate2(s->file, DSET_REG_REF_NAME, H5T_STD_REF, sid, H5P_DEFAULT, H5P_DEFAULT,
+                                      H5P_DEFAULT)) < 0) {
+            HDprintf("H5Dcreate2 failed\n");
+            TEST_ERROR;
+        }
+
+        if (H5Sclose(sid) < 0) {
+            HDprintf("H5Sclose failed\n");
+            TEST_ERROR;
+        }
+
+        if ((ds->reg_buf = HDcalloc(sizeof(H5R_ref_t), REG_REF_DIMS)) == NULL) {
+            HDprintf("HDcalloc failed\n");
+            TEST_ERROR;
+        }
+    }
+
     return true;
 
 error:
@@ -656,16 +824,24 @@ error:
         H5Sclose(ds->fa_sid);
         H5Sclose(ds->ea_sid);
         H5Sclose(ds->bt2_sid);
+        H5Sclose(sid);
         H5Dclose(ds->compact_did);
         H5Dclose(ds->contig_did);
         H5Dclose(ds->single_did);
-        H5Dclose(ds->implicit_did);
+        H5Sclose(ds->implicit_did);
         H5Dclose(ds->fa_did);
         H5Dclose(ds->ea_did);
         H5Dclose(ds->bt2_did);
+        H5Dclose(ds->obj_did);
+        H5Dclose(ds->reg_did);
     }
     H5E_END_TRY;
 
+    if (obj_buf)
+        HDfree(obj_buf);
+    if (ds->reg_buf)
+        HDfree(ds->reg_buf);
+
     return false;
 
 } /* create_dsets() */
@@ -676,10 +852,54 @@ error:
 static bool
 open_dsets(const state_t *s, dsets_state_t *ds)
 {
+    H5R_ref_t *obj_buf = NULL; /* Buffer for holding object references */
+    unsigned   i;
+
     *ds = DSETS_INITIALIZER;
 
+    /* If object reference is specified: */
+    /* open the object reference dataset and retrieve the dataset object references */
+    if (s->obj_ref) {
+        if ((ds->obj_did = H5Dopen2(s->file, DSET_OBJ_REF_NAME, H5P_DEFAULT)) < 0) {
+            HDprintf("HDopen2 object reference dataset failed\n");
+            TEST_ERROR;
+        }
+
+        if (H5Drefresh(ds->obj_did) < 0) {
+            HDprintf("HDrefresh failed\n");
+            TEST_ERROR;
+        }
+
+        if ((obj_buf = HDcalloc(sizeof(H5R_ref_t), OBJ_REF_DIMS)) == NULL) {
+            HDprintf("HDcalloc failed\n");
+            TEST_ERROR;
+        }
+
+        /* Obtain the object references */
+        if (H5Dread(ds->obj_did, H5T_STD_REF, H5S_ALL, H5S_ALL, H5P_DEFAULT, obj_buf) < 0) {
+            HDprintf("HDread failed\n");
+            TEST_ERROR;
+        }
+    }
+
+    /* If region reference is specified: */
+    /* open the region reference dataset and allocate buffer for holding the region references */
+    if (s->reg_ref) {
+        if ((ds->reg_did = H5Dopen2(s->file, DSET_REG_REF_NAME, H5P_DEFAULT)) < 0) {
+            HDprintf("HDopen2 region reference dataset failed\n");
+            TEST_ERROR;
+        }
+
+        /* Allocate the buffer for holding the region references */
+        if ((ds->reg_buf = HDcalloc(sizeof(H5R_ref_t), REG_REF_DIMS)) == NULL) {
+            HDprintf("HDcalloc failed\n");
+            TEST_ERROR;
+        }
+    }
+
     if (s->compact) {
-        if (!open_dset_real(s, &ds->compact_did, &ds->compact_sid, DSET_COMPACT_NAME)) {
+        if (!open_dset_real(s, &ds->compact_did, &ds->compact_sid, DSET_COMPACT_NAME,
+                            s->obj_ref ? &obj_buf[0] : NULL)) {
             HDprintf("open_dset_real() for compact dataset failed\n");
             TEST_ERROR;
         }
@@ -687,7 +907,8 @@ open_dsets(const state_t *s, dsets_state_t *ds)
 
     if (s->contig) {
 
-        if (!open_dset_real(s, &ds->contig_did, &ds->contig_sid, DSET_CONTIG_NAME)) {
+        if (!open_dset_real(s, &ds->contig_did, &ds->contig_sid, DSET_CONTIG_NAME,
+                            s->obj_ref ? &obj_buf[1] : NULL)) {
             HDprintf("open_dset_real() for contiguous dataset failed\n");
             TEST_ERROR;
         }
@@ -695,35 +916,61 @@ open_dsets(const state_t *s, dsets_state_t *ds)
 
     if (s->chunked) {
 
-        if (!open_dset_real(s, &ds->single_did, &ds->single_sid, DSET_SINGLE_NAME)) {
+        if (!open_dset_real(s, &ds->single_did, &ds->single_sid, DSET_SINGLE_NAME,
+                            s->obj_ref ? &obj_buf[2] : NULL)) {
             HDprintf("open_dset_real() for chunked dataset: single index failed\n");
             TEST_ERROR;
         }
 
-        if (!open_dset_real(s, &ds->implicit_did, &ds->implicit_sid, DSET_IMPLICIT_NAME)) {
+        if (!open_dset_real(s, &ds->implicit_did, &ds->implicit_sid, DSET_IMPLICIT_NAME,
+                            s->obj_ref ? &obj_buf[3] : NULL)) {
             HDprintf("open_dset_real() for chunked dataset: implicit index failed\n");
             TEST_ERROR;
         }
 
-        if (!open_dset_real(s, &ds->fa_did, &ds->fa_sid, DSET_FA_NAME)) {
+        if (!open_dset_real(s, &ds->fa_did, &ds->fa_sid, DSET_FA_NAME, s->obj_ref ? &obj_buf[4] : NULL)) {
             HDprintf("open_dset_real() for chunked dataset: fa index failed\n");
             TEST_ERROR;
         }
 
-        if (!open_dset_real(s, &ds->ea_did, &ds->ea_sid, DSET_EA_NAME)) {
+        if (!open_dset_real(s, &ds->ea_did, &ds->ea_sid, DSET_EA_NAME, s->obj_ref ? &obj_buf[5] : NULL)) {
             HDprintf("open_dset_real() for chunked dataset: ea index failed\n");
             TEST_ERROR;
         }
 
-        if (!open_dset_real(s, &ds->bt2_did, &ds->bt2_sid, DSET_BT2_NAME)) {
+        if (!open_dset_real(s, &ds->bt2_did, &ds->bt2_sid, DSET_BT2_NAME, s->obj_ref ? &obj_buf[6] : NULL)) {
             HDprintf("open_dset_real() for chunked dataset: bt2 index failed\n");
             TEST_ERROR;
         }
     }
 
+    /* Destroy the object references */
+    if (s->obj_ref) {
+        for (i = 0; i < OBJ_REF_DIMS; i++)
+            if (H5Rdestroy(&obj_buf[i]) < 0) {
+                HDprintf("H5Rdestroy object references\n");
+                TEST_ERROR;
+            }
+
+        if (obj_buf)
+            HDfree(obj_buf);
+    }
+
     return true;
 
 error:
+    H5E_BEGIN_TRY
+    {
+        H5Dclose(ds->obj_did);
+        H5Dclose(ds->reg_did);
+    }
+    H5E_END_TRY;
+
+    if (obj_buf)
+        HDfree(obj_buf);
+    if (ds->reg_buf)
+        HDfree(ds->reg_buf);
+
     return false;
 
 } /* open_dsets() */
@@ -733,13 +980,30 @@ error:
  * Verify the dimension sizes are as expected.
  */
 static bool
-open_dset_real(const state_t *s, hid_t *did, hid_t *sid, const char *name)
+open_dset_real(const state_t *s, hid_t *did, hid_t *sid, const char *name, H5R_ref_t *obj_buf)
 {
     hsize_t dims[2];
 
-    if ((*did = H5Dopen2(s->file, name, H5P_DEFAULT)) < 0) {
-        HDprintf("H5Dopen dataset failed\n");
-        TEST_ERROR;
+    /* If object reference is enabled, obtain the dataset object ID
+        via H5Ropen_object(). */
+    if (s->obj_ref) {
+        H5E_BEGIN_TRY
+        {
+            *did = H5Ropen_object(obj_buf, H5P_DEFAULT, H5P_DEFAULT);
+        }
+        H5E_END_TRY;
+        if (*did < 0) {
+            HDprintf("H5Ropen_object failed\n");
+            TEST_ERROR;
+        }
+    }
+    else {
+        HDassert(obj_buf == NULL);
+
+        if ((*did = H5Dopen2(s->file, name, H5P_DEFAULT)) < 0) {
+            HDprintf("H5Dopen dataset failed\n");
+            TEST_ERROR;
+        }
     }
 
     if ((*sid = H5Dget_space(*did)) < 0) {
@@ -777,7 +1041,7 @@ error:
  * Close all the datasets and dataspaces as specified.
  */
 static bool
-close_dsets(const dsets_state_t *ds)
+close_dsets(dsets_state_t *ds)
 {
     if (!close_dset_real(ds->compact_did, ds->compact_sid)) {
         HDprintf("H5Dclose compact dataset failed\n");
@@ -814,6 +1078,11 @@ close_dsets(const dsets_state_t *ds)
         TEST_ERROR;
     }
 
+    if (ds->reg_buf) {
+        HDfree(ds->reg_buf);
+        ds->reg_buf = NULL;
+    }
+
     return true;
 
 error:
@@ -979,6 +1248,7 @@ dsets_action(unsigned action, const state_t *s, const dsets_state_t *ds, unsigne
     hsize_t       block[2];
     hid_t         mem_sid;
     unsigned int *wbuf = NULL;
+    unsigned      i;
 
     /* Set up selection, dataspace and data buffer according to the specified action */
     if (!dset_setup(action, which, s, start, stride, count, block, &mem_sid, &wbuf)) {
@@ -989,8 +1259,8 @@ dsets_action(unsigned action, const state_t *s, const dsets_state_t *ds, unsigne
     /* Write to the contiguous dataset */
     if (s->contig) {
 
-        if (!write_dset(ds->contig_did, s->filetype, mem_sid, ds->contig_sid, start, stride, count, block,
-                        wbuf)) {
+        if (!write_dset(s, DSET_CONTIG_NAME, ds->contig_did, ds->contig_sid, mem_sid, start, stride, count,
+                        block, wbuf, s->reg_ref ? &ds->reg_buf[0] : NULL)) {
             HDprintf("H5Dwrite to contiguous dataset failed\n");
             TEST_ERROR;
         }
@@ -999,36 +1269,53 @@ dsets_action(unsigned action, const state_t *s, const dsets_state_t *ds, unsigne
     /* Write to the 5 chunked datasets */
     if (s->chunked) {
 
-        if (!write_dset(ds->single_did, s->filetype, mem_sid, ds->single_sid, start, stride, count, block,
-                        wbuf)) {
+        if (!write_dset(s, DSET_SINGLE_NAME, ds->single_did, ds->single_sid, mem_sid, start, stride, count,
+                        block, wbuf, s->reg_ref ? &ds->reg_buf[1] : NULL)) {
             HDprintf("H5Dwrite to chunked dataset: single index dataset failed\n");
             TEST_ERROR;
         }
 
-        if (!write_dset(ds->implicit_did, s->filetype, mem_sid, ds->implicit_sid, start, stride, count, block,
-                        wbuf)) {
+        if (!write_dset(s, DSET_IMPLICIT_NAME, ds->implicit_did, ds->implicit_sid, mem_sid, start, stride,
+                        count, block, wbuf, s->reg_ref ? &ds->reg_buf[2] : NULL)) {
             HDprintf("H5Dwrite to chunked dataset: implicit index dataset failed\n");
             TEST_ERROR;
         }
 
-        if (!write_dset(ds->fa_did, s->filetype, mem_sid, ds->fa_sid, start, stride, count, block, wbuf)) {
+        if (!write_dset(s, DSET_FA_NAME, ds->fa_did, ds->fa_sid, mem_sid, start, stride, count, block, wbuf,
+                        s->reg_ref ? &ds->reg_buf[3] : NULL)) {
             HDprintf("H5Dwrite to chunked dataset: fa index dataset failed\n");
             TEST_ERROR;
         }
 
-        if (!write_dset(ds->ea_did, s->filetype, mem_sid, ds->ea_sid, start, stride, count, block, wbuf)) {
+        if (!write_dset(s, DSET_EA_NAME, ds->ea_did, ds->ea_sid, mem_sid, start, stride, count, block, wbuf,
+                        s->reg_ref ? &ds->reg_buf[4] : NULL)) {
             HDprintf("H5Dwrite to chunked dataset: ea index dataset failed\n");
             TEST_ERROR;
         }
 
-        if (!write_dset(ds->bt2_did, s->filetype, mem_sid, ds->bt2_sid, start, stride, count, block, wbuf)) {
+        if (!write_dset(s, DSET_BT2_NAME, ds->bt2_did, ds->bt2_sid, mem_sid, start, stride, count, block,
+                        wbuf, s->reg_ref ? &ds->reg_buf[5] : NULL)) {
             HDprintf("H5Dwrite to chunked dataset: bt2 index dataset failed\n");
             TEST_ERROR;
         }
     }
 
+    /* If region reference is enabled, store the region references to the reference dataset */
+    if (s->reg_ref) {
+        if (H5Dwrite(ds->reg_did, H5T_STD_REF, H5S_ALL, H5S_ALL, H5P_DEFAULT, ds->reg_buf) < 0) {
+            HDprintf("H5Dwrite failed\n");
+            TEST_ERROR;
+        }
+        for (i = 0; i < 6; i++)
+            if (H5Rdestroy(&ds->reg_buf[i]) < 0) {
+                HDprintf("H5Rdestroy failed\n");
+                TEST_ERROR;
+            }
+    }
+
     if (wbuf)
         HDfree(wbuf);
+
     return true;
 
 error:
@@ -1126,20 +1413,28 @@ error:
  * Make the selection and then write to the dataset.
  */
 static bool
-write_dset(hid_t did, hid_t tid, hid_t mem_sid, hid_t file_sid, hsize_t *start, hsize_t *stride,
-           hsize_t *count, hsize_t *block, unsigned int *buf)
+write_dset(const state_t *s, const char *name, hid_t did, hid_t sid, hid_t mem_sid, hsize_t *start,
+           hsize_t *stride, hsize_t *count, hsize_t *block, unsigned int *buf, H5R_ref_t *reg_buf)
 {
-
-    if (H5Sselect_hyperslab(file_sid, H5S_SELECT_SET, start, stride, count, block) < 0) {
+    if (H5Sselect_hyperslab(sid, H5S_SELECT_SET, start, stride, count, block) < 0) {
         HDprintf("H5Sselect to dataset failed\n");
         TEST_ERROR;
     }
 
-    if (H5Dwrite(did, tid, mem_sid, file_sid, H5P_DEFAULT, buf) < 0) {
+    if (H5Dwrite(did, s->filetype, mem_sid, sid, H5P_DEFAULT, buf) < 0) {
         HDprintf("H5Dwrite to dataset failed\n");
         TEST_ERROR;
     }
 
+    /* If region reference is enabled, store the region reference to the reference buffer */
+    if (s->reg_ref) {
+        HDassert(reg_buf != NULL);
+        if (H5Rcreate_region(s->file, name, sid, H5P_DEFAULT, reg_buf) < 0) {
+            HDprintf("H5Rcreate_region failed\n");
+            TEST_ERROR;
+        }
+    }
+
     return true;
 
 error:
@@ -1218,7 +1513,7 @@ verify_dsets_operations(state_t *s, dsets_state_t *ds, H5F_vfd_swmr_config_t *co
             result = verify_dset_compact(s, ds, fileclosed, config->flush_raw_data);
 
             if (s->use_np && !np_reader(result, 0, s, np)) {
-                HDprintf("np_reader() for verifying addition failed\n");
+                HDprintf("np_reader() for verifying writes failed\n");
                 TEST_ERROR;
             }
             else if (!result)
@@ -1250,7 +1545,7 @@ verify_dsets_operations(state_t *s, dsets_state_t *ds, H5F_vfd_swmr_config_t *co
                 result = verify_dsets_action(SEQ_WRITE, s, ds, step, fileclosed);
 
                 if (s->use_np && !np_reader(result, step, s, np)) {
-                    HDprintf("np_reader() for verifying addition failed\n");
+                    HDprintf("np_reader() for verifying writes failed\n");
                     TEST_ERROR;
                 }
                 else if (!result)
@@ -1286,7 +1581,7 @@ verify_dsets_operations(state_t *s, dsets_state_t *ds, H5F_vfd_swmr_config_t *co
                 result = verify_dsets_action(RANDOM_WRITE, s, ds, newstep, fileclosed);
 
                 if (s->use_np && !np_reader(result, step, s, np)) {
-                    HDprintf("np_reader() for verifying addition failed\n");
+                    HDprintf("np_reader() for verifying writes failed\n");
                     TEST_ERROR;
                 }
                 else if (!result)
@@ -1316,7 +1611,7 @@ verify_dsets_operations(state_t *s, dsets_state_t *ds, H5F_vfd_swmr_config_t *co
                 result = verify_dsets_action(HYPER_WRITE, s, ds, k, fileclosed);
 
                 if (s->use_np && !np_reader(result, step, s, np)) {
-                    HDprintf("np_reader() for verifying addition failed\n");
+                    HDprintf("np_reader() for verifying writes failed\n");
                     TEST_ERROR;
                 }
                 else if (!result)
@@ -1345,7 +1640,7 @@ verify_dsets_operations(state_t *s, dsets_state_t *ds, H5F_vfd_swmr_config_t *co
                 result = verify_dsets_action(MODIFY_DATA, s, ds, step, fileclosed);
 
                 if (s->use_np && !np_reader(result, step, s, np)) {
-                    HDprintf("np_reader() for verifying addition failed\n");
+                    HDprintf("np_reader() for verifying writes failed\n");
                     TEST_ERROR;
                 }
                 else if (!result)
@@ -1359,7 +1654,7 @@ verify_dsets_operations(state_t *s, dsets_state_t *ds, H5F_vfd_swmr_config_t *co
 error:
     return false;
 
-} /* Verify_dsets_operations() */
+} /* verify_dsets_operations() */
 
 /*
  * Verify the data read from each of the datasets specified on the command line
@@ -1379,6 +1674,19 @@ verify_dsets_action(unsigned action, const state_t *s, const dsets_state_t *ds,
     hsize_t       block[2];
     hid_t         mem_sid;
     unsigned int *vbuf = NULL;
+    unsigned      i;
+
+    /* If region reference is enabled, obtain the region references from the reference dataset */
+    if (s->reg_ref) {
+        if (H5Drefresh(ds->reg_did) < 0) {
+            HDprintf("H5Drefresh region reference dataset failed\n");
+            TEST_ERROR;
+        }
+        if (H5Dread(ds->reg_did, H5T_STD_REF, H5S_ALL, H5S_ALL, H5P_DEFAULT, ds->reg_buf) < 0) {
+            HDprintf("H5Dread failed\n");
+            TEST_ERROR;
+        }
+    }
 
     /* Set up selection, dataspace and data buffer according to the specified action */
     if (!dset_setup(action, which, s, start, stride, count, block, &mem_sid, &vbuf)) {
@@ -1388,8 +1696,9 @@ verify_dsets_action(unsigned action, const state_t *s, const dsets_state_t *ds,
 
     /* Verify the data read for the contiguous dataset */
     if (s->contig) {
-        if (!verify_dset(ds->contig_did, s->filetype, mem_sid, ds->contig_sid, start, stride, count, block,
-                         vbuf, fileclosed, s->flush_raw_data)) {
+
+        if (!verify_dset(ds->contig_did, s->filetype, ds->contig_sid, mem_sid, start, stride, count, block,
+                         vbuf, fileclosed, s->flush_raw_data, s->reg_ref ? &ds->reg_buf[0] : NULL)) {
             HDprintf("verify_dset() to contiguous dataset failed\n");
             TEST_ERROR;
         }
@@ -1398,32 +1707,32 @@ verify_dsets_action(unsigned action, const state_t *s, const dsets_state_t *ds,
     /* Verify the data read for the chunked datasets */
     if (s->chunked) {
 
-        if (!verify_dset(ds->single_did, s->filetype, mem_sid, ds->single_sid, start, stride, count, block,
-                         vbuf, fileclosed, s->flush_raw_data)) {
+        if (!verify_dset(ds->single_did, s->filetype, ds->single_sid, mem_sid, start, stride, count, block,
+                         vbuf, fileclosed, s->flush_raw_data, s->reg_ref ? &ds->reg_buf[1] : NULL)) {
             HDprintf("verify_dset() to chunked dataset: single index dataset failed\n");
             TEST_ERROR;
         }
 
-        if (!verify_dset(ds->implicit_did, s->filetype, mem_sid, ds->implicit_sid, start, stride, count,
-                         block, vbuf, fileclosed, s->flush_raw_data)) {
+        if (!verify_dset(ds->implicit_did, s->filetype, ds->implicit_sid, mem_sid, start, stride, count,
+                         block, vbuf, fileclosed, s->flush_raw_data, s->reg_ref ? &ds->reg_buf[2] : NULL)) {
             HDprintf("verify_dset() to chunked dataset: implicit index dataset failed\n");
             TEST_ERROR;
         }
 
-        if (!verify_dset(ds->fa_did, s->filetype, mem_sid, ds->fa_sid, start, stride, count, block, vbuf,
-                         fileclosed, s->flush_raw_data)) {
+        if (!verify_dset(ds->fa_did, s->filetype, ds->fa_sid, mem_sid, start, stride, count, block, vbuf,
+                         fileclosed, s->flush_raw_data, s->reg_ref ? &ds->reg_buf[3] : NULL)) {
             HDprintf("verify_dset() to chunked dataset: fa index dataset failed\n");
             TEST_ERROR;
         }
 
-        if (!verify_dset(ds->ea_did, s->filetype, mem_sid, ds->ea_sid, start, stride, count, block, vbuf,
-                         fileclosed, s->flush_raw_data)) {
+        if (!verify_dset(ds->ea_did, s->filetype, ds->ea_sid, mem_sid, start, stride, count, block, vbuf,
+                         fileclosed, s->flush_raw_data, s->reg_ref ? &ds->reg_buf[4] : NULL)) {
             HDprintf("verify_dset() to chunked dataset: ea index dataset failed\n");
             TEST_ERROR;
         }
 
-        if (!verify_dset(ds->bt2_did, s->filetype, mem_sid, ds->bt2_sid, start, stride, count, block, vbuf,
-                         fileclosed, s->flush_raw_data)) {
+        if (!verify_dset(ds->bt2_did, s->filetype, ds->bt2_sid, mem_sid, start, stride, count, block, vbuf,
+                         fileclosed, s->flush_raw_data, s->reg_ref ? &ds->reg_buf[5] : NULL)) {
             HDprintf("verify_dset() to chunked dataset: bt2 index dataset failed\n");
             TEST_ERROR;
         }
@@ -1432,6 +1741,14 @@ verify_dsets_action(unsigned action, const state_t *s, const dsets_state_t *ds,
     if (vbuf)
         HDfree(vbuf);
 
+    if (s->reg_ref) {
+        for (i = 0; i < 6; i++)
+            if (H5Rdestroy(&ds->reg_buf[i]) < 0) {
+                HDprintf("H5Rdestroy failed\n");
+                TEST_ERROR;
+            }
+    }
+
     return true;
 
 error:
@@ -1447,8 +1764,8 @@ error:
  * `vbuf` contains the data expected from the read.
  */
 static bool
-verify_dset(hid_t did, hid_t tid, hid_t mem_sid, hid_t file_sid, hsize_t *start, hsize_t *stride,
-            hsize_t *count, hsize_t *block, unsigned int *vbuf, bool fileclosed, bool flush_raw_data)
+verify_dset(hid_t did, hid_t tid, hid_t sid, hid_t mem_sid, hsize_t *start, hsize_t *stride, hsize_t *count,
+            hsize_t *block, unsigned int *vbuf, bool fileclosed, bool flush_raw_data, H5R_ref_t *reg_buf)
 {
     unsigned int *rbuf = NULL;
     unsigned      i;
@@ -1465,14 +1782,32 @@ verify_dset(hid_t did, hid_t tid, hid_t mem_sid, hid_t file_sid, hsize_t *start,
         TEST_ERROR;
     }
 
-    /* Make the selection the file dataspace */
-    if (H5Sselect_hyperslab(file_sid, H5S_SELECT_SET, start, stride, count, block) < 0) {
-        HDprintf("H5Sselect to dataset failed\n");
-        TEST_ERROR;
+    /* If region reference is enabled, obtain the dataset selection from the reference buffer */
+    if (reg_buf != NULL) { /* Imply region reference is enabled */
+        hid_t temp_sid = badhid;
+
+        H5E_BEGIN_TRY
+        {
+            temp_sid = H5Ropen_region(reg_buf, H5P_DEFAULT, H5P_DEFAULT);
+        }
+        H5E_END_TRY;
+
+        if (temp_sid < 0) {
+            HDprintf("H5Ropen_region failed\n");
+            TEST_ERROR;
+        }
+        sid = temp_sid;
+    }
+    else {
+        /* Make the selection the file dataspace */
+        if (H5Sselect_hyperslab(sid, H5S_SELECT_SET, start, stride, count, block) < 0) {
+            HDprintf("H5Sselect_hyperslab failed\n");
+            TEST_ERROR;
+        }
     }
 
     /* Read the data from the dataset into `rbuf` */
-    if (H5Dread(did, tid, mem_sid, file_sid, H5P_DEFAULT, rbuf) < 0) {
+    if (H5Dread(did, tid, mem_sid, sid, H5P_DEFAULT, rbuf) < 0) {
         HDprintf("H5Dread from dataset failed\n");
         TEST_ERROR;
     }
diff --git a/test/vfd_swmr_generator.c b/test/vfd_swmr_generator.c
index 1c549ca..e11d92f 100644
--- a/test/vfd_swmr_generator.c
+++ b/test/vfd_swmr_generator.c
@@ -1,5 +1,6 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
  * Copyright by The HDF Group.                                               *
+ * Copyright by Akadio, Inc.                                                 *
  * All rights reserved.                                                      *
  *                                                                           *
  * This file is part of HDF5.  The full HDF5 copyright notice, including     *
diff --git a/test/vfd_swmr_gfail_writer.c b/test/vfd_swmr_gfail_writer.c
index aef39a0..84a9e80 100644
--- a/test/vfd_swmr_gfail_writer.c
+++ b/test/vfd_swmr_gfail_writer.c
@@ -1,5 +1,6 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
  * Copyright by The HDF Group.                                               *
+ * Copyright by Akadio, Inc.                                                 *
  * All rights reserved.                                                      *
  *                                                                           *
  * This file is part of HDF5.  The full HDF5 copyright notice, including     *
diff --git a/test/vfd_swmr_gperf_writer.c b/test/vfd_swmr_gperf_writer.c
index 1ca4483..8632bf8 100644
--- a/test/vfd_swmr_gperf_writer.c
+++ b/test/vfd_swmr_gperf_writer.c
@@ -1,5 +1,6 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
  * Copyright by The HDF Group.                                               *
+ * Copyright by Akadio, Inc.                                                 *
  * All rights reserved.                                                      *
  *                                                                           *
  * This file is part of HDF5.  The full HDF5 copyright notice, including     *
diff --git a/test/vfd_swmr_group_writer.c b/test/vfd_swmr_group_writer.c
index eb7bb0e..3dea01d 100644
--- a/test/vfd_swmr_group_writer.c
+++ b/test/vfd_swmr_group_writer.c
@@ -1,5 +1,6 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
  * Copyright by The HDF Group.                                               *
+ * Copyright by Akadio, Inc.                                                 *
  * All rights reserved.                                                      *
  *                                                                           *
  * This file is part of HDF5.  The full HDF5 copyright notice, including     *
diff --git a/test/vfd_swmr_indep_rw_writer.c b/test/vfd_swmr_indep_rw_writer.c
index f452e89..75da581 100644
--- a/test/vfd_swmr_indep_rw_writer.c
+++ b/test/vfd_swmr_indep_rw_writer.c
@@ -1,15 +1,15 @@
-/*
- * Copyright by The HDF Group.
- * Copyright by the Board of Trustees of the University of Illinois.
- * All rights reserved.
- *
- * This file is part of HDF5.  The full HDF5 copyright notice, including
- * terms governing use, modification, and redistribution, is contained in
- * the COPYING file, which can be found at the root of the source code
- * distribution tree, or in https://support.hdfgroup.org/ftp/HDF5/releases.
- * If you do not have access to either file, you may request a copy from
- * help@hdfgroup.org.
- */
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by The HDF Group.                                               *
+ * Copyright by Akadio, Inc.                                                 *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5.  The full HDF5 copyright notice, including     *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the COPYING file, which can be found at the root of the source code       *
+ * distribution tree, or in https://www.hdfgroup.org/licenses.               *
+ * If you do not have access to either file, you may request a copy from     *
+ * help@hdfgroup.org.                                                        *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
 /* This program checks independence of writer and reader for VFD SWMR.
  * A writer can also be a reader of another writer. A reader can also be a
diff --git a/test/vfd_swmr_reader.c b/test/vfd_swmr_reader.c
index d6a87dd..c04182c 100644
--- a/test/vfd_swmr_reader.c
+++ b/test/vfd_swmr_reader.c
@@ -1,5 +1,6 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
  * Copyright by The HDF Group.                                               *
+ * Copyright by Akadio, Inc.                                                 *
  * All rights reserved.                                                      *
  *                                                                           *
  * This file is part of HDF5.  The full HDF5 copyright notice, including     *
diff --git a/test/vfd_swmr_remove_reader.c b/test/vfd_swmr_remove_reader.c
index bc00756..ed2de5f 100644
--- a/test/vfd_swmr_remove_reader.c
+++ b/test/vfd_swmr_remove_reader.c
@@ -1,5 +1,6 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
  * Copyright by The HDF Group.                                               *
+ * Copyright by Akadio, Inc.                                                 *
  * All rights reserved.                                                      *
  *                                                                           *
  * This file is part of HDF5.  The full HDF5 copyright notice, including     *
diff --git a/test/vfd_swmr_remove_writer.c b/test/vfd_swmr_remove_writer.c
index 6b0c13f..a35d303 100644
--- a/test/vfd_swmr_remove_writer.c
+++ b/test/vfd_swmr_remove_writer.c
@@ -1,5 +1,6 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
  * Copyright by The HDF Group.                                               *
+ * Copyright by Akadio, Inc.                                                 *
  * All rights reserved.                                                      *
  *                                                                           *
  * This file is part of HDF5.  The full HDF5 copyright notice, including     *
diff --git a/test/vfd_swmr_sparse_reader.c b/test/vfd_swmr_sparse_reader.c
index 6a7ba2f..d0a03a8 100644
--- a/test/vfd_swmr_sparse_reader.c
+++ b/test/vfd_swmr_sparse_reader.c
@@ -1,5 +1,6 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
  * Copyright by The HDF Group.                                               *
+ * Copyright by Akadio, Inc.                                                 *
  * All rights reserved.                                                      *
  *                                                                           *
  * This file is part of HDF5.  The full HDF5 copyright notice, including     *
diff --git a/test/vfd_swmr_sparse_writer.c b/test/vfd_swmr_sparse_writer.c
index f78bf8b..2b976d3 100644
--- a/test/vfd_swmr_sparse_writer.c
+++ b/test/vfd_swmr_sparse_writer.c
@@ -1,5 +1,6 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
  * Copyright by The HDF Group.                                               *
+ * Copyright by Akadio, Inc.                                                 *
  * All rights reserved.                                                      *
  *                                                                           *
  * This file is part of HDF5.  The full HDF5 copyright notice, including     *
diff --git a/test/vfd_swmr_vlstr_reader.c b/test/vfd_swmr_vlstr_reader.c
index 2554207..4107bfc 100644
--- a/test/vfd_swmr_vlstr_reader.c
+++ b/test/vfd_swmr_vlstr_reader.c
@@ -1,5 +1,6 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
  * Copyright by The HDF Group.                                               *
+ * Copyright by Akadio, Inc.                                                 *
  * All rights reserved.                                                      *
  *                                                                           *
  * This file is part of HDF5.  The full HDF5 copyright notice, including     *
diff --git a/test/vfd_swmr_vlstr_writer.c b/test/vfd_swmr_vlstr_writer.c
index e3905e8..8fc3f95 100644
--- a/test/vfd_swmr_vlstr_writer.c
+++ b/test/vfd_swmr_vlstr_writer.c
@@ -1,5 +1,6 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
  * Copyright by The HDF Group.                                               *
+ * Copyright by Akadio, Inc.                                                 *
  * All rights reserved.                                                      *
  *                                                                           *
  * This file is part of HDF5.  The full HDF5 copyright notice, including     *
diff --git a/test/vfd_swmr_writer.c b/test/vfd_swmr_writer.c
index a630532..db0c90b 100644
--- a/test/vfd_swmr_writer.c
+++ b/test/vfd_swmr_writer.c
@@ -1,5 +1,6 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
  * Copyright by The HDF Group.                                               *
+ * Copyright by Akadio, Inc.                                                 *
  * All rights reserved.                                                      *
  *                                                                           *
  * This file is part of HDF5.  The full HDF5 copyright notice, including     *
diff --git a/test/vfd_swmr_zoo_writer.c b/test/vfd_swmr_zoo_writer.c
index d40f2d9..97c4db3 100644
--- a/test/vfd_swmr_zoo_writer.c
+++ b/test/vfd_swmr_zoo_writer.c
@@ -1,5 +1,6 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
  * Copyright by The HDF Group.                                               *
+ * Copyright by Akadio, Inc.                                                 *
  * All rights reserved.                                                      *
  *                                                                           *
  * This file is part of HDF5.  The full HDF5 copyright notice, including     *
diff --git a/utils/CMakeLists.txt b/utils/CMakeLists.txt
index 2d5626e..d6a5afd 100644
--- a/utils/CMakeLists.txt
+++ b/utils/CMakeLists.txt
@@ -2,3 +2,4 @@ cmake_minimum_required (VERSION 3.10)
 project (HDF5_UTILS C)
 
 add_subdirectory (mirror_vfd)
+add_subdirectory (vfd_swmr)
diff --git a/utils/Makefile.am b/utils/Makefile.am
index 288da37..fa877ef 100644
--- a/utils/Makefile.am
+++ b/utils/Makefile.am
@@ -21,6 +21,6 @@ include $(top_srcdir)/config/commence.am
 CONFIG=ordered
 
 # All subdirectories
-SUBDIRS=mirror_vfd
+SUBDIRS=mirror_vfd vfd_swmr
 
 include $(top_srcdir)/config/conclude.am
diff --git a/utils/vfd_swmr b/utils/vfd_swmr
-Subproject 5f4b020713f3194222311b2e87b29f0de0722ed
+Subproject 121da9672cebea43dca05c89adaae5d05ba56e4