Hdf5 merge issue 537 v112 (#538)

* Snapshot version 1.12 release 1-3.  Update  version to 1.12.1-4.

* First cut of the H5 public API documentation. (#80)

* First cut of the H5 public API documentation.

* Added H5Z "bonus track."

* Applied Quincey's patch.

* Added the missing patches from Quincey's original patch.

* H5PL (complete) and basic H5VL API documentation.

* Added H5I API docs.

* Added H5L API docs.

* First installment from Elena's H5T batch.

* Second installment of Elena's H5T batch.

* Final installment of Elena's H5T batch.

* Full set of current H5F documentation. (#105)

* First cut of the H5 public API documentation.

* Added H5Z "bonus track."

* Applied Quincey's patch.

* Added the missing patches from Quincey's original patch.

* H5PL (complete) and basic H5VL API documentation.

* Added H5I API docs.

* Added H5L API docs.

* First installment from Elena's H5T batch.

* Second installment of Elena's H5T batch.

* Final installment of Elena's H5T batch.

* Migrated documentation for SWMR functions.

* Catching up on MDC functions.

* Integrated the H5F MDC function documentation.

* Added MDC and parallel H5F functions.

* Slightly updated main page.

* Added doxygen/dox/H5AC_cache_config_t.dox to MANIFEST.

* Doxygen - added (mostly) beginner functions (#112)

* Doxygen - added (mostly) beginner functions

* Removed duplicate H5Pset_szip function

* Add src/H5module.h to MANIFEST.

* close #195. (#196)

* Update HDF5PluginMacros.cmake

* Update HDF5PluginMacros.cmake

* Avoid aligned access for references by decoding into temporary buffer and then copying the result into the actual buffer.   Update test to be more thorough with using compound datatype fields everywhere. (#206)

* Modify temporary rpath for testing in java example scripts. (#230)

* Fix undefined left shifting of negative numbers (#338)

Undefined Bahavior Sanitizer errored here about left shifting negative numbers.

* Fixes various warnings noticed on Windows (#425)

* Fixes various warnings noticed on Windows

- Adds a prototype for our implementation of vasprintf
- Return type of H5_get_utf16_str() is now non-const
- Fixes possible uninitialized return type in Wremove_utf8
- Better isolation of fork() code in accum.c:test_swmr_write_big()
- Better isolation of non-zlib code in dsets.c:test_filter_delete()
- Removed unused variable in trefer.c:test_reference_cmpnd_obj()

* Fixes clang-format issues

* Applied clang-tidy readability-non-const-parameter warning fixes auto… (#429)

* Automatically applied clang-tidy readability-avoid-const-params-in-decls fixes

Removes useless const declarations.

* Fixed most readability-non-const-parameter warnings

These changes were made automatically by clang-tidy, but I manually reverted the changes related to the H5Z_func_t signature.

* Reformat source with clang v10.0.1.

Co-authored-by: Larry Knox <lrknox@hdfgroup.org>

* Added C++11 override keyword where appropriate (#433)

Added H5_OVERRIDE macro for compatibility with both C++11 and older.

* Various clang tidy warning fixes (#448)

* Fixed clang-tidy bugprone-reserved-identifier warnings

* Fixed clang-tidy bugprone-assert-side-effect warnings

* Fixed clang-tidy bugprone-copy-constructor-init warning

* Fixed clang-tidy readability-redundant-preprocessor warning

For error_test.c the removed code was already dead, because it was in the else of an `#if H5_USE_16_API` block.

Based on H5Location.h, I think p_get_ref_obj_type was meant to be in `#ifndef DOXYGEN_SHOULD_SKIP_THIS` and an `#endif` was missing.  Similarly, in the header, getObjTypeByIdx is only in H5_NO_DEPRECATED_SYMBOLS, not DOXYGEN_SHOULD_SKIP_THIS.

* Fixed clang-tidy readability-redundant-string-init warnings

* Fixed some clang-tidy performance-type-promotion-in-math-fn warnings

* Fixed clang-tidy performance-unnecessary-value-param warnings

* Reformat source with clang v10.0.1.

Co-authored-by: Larry Knox <lrknox@hdfgroup.org>

* Removed checks/workarounds for pre-C++89 compatibility (#449)

After 30+ years, just assume that the following exist:
- extension-less includes
- namespaces
- std::
- static_cast
- bool

* Fixed all clang-tidy bugprone-suspicious-string-compare warnings (#451)

* Fixed all clang-tidy bugprone-suspicious-string-compare warnings

This change was generated entirely by clang-tidy itself.

* Reformat code with clang v10.0.1.

Co-authored-by: Larry Knox <lrknox@hdfgroup.org>

* Remove 2 functions incorrectly merged from develop in a cherry-pick merge of PR #451.

* More warning fixes (#400)

* Fixed -Wunused-local-typedef warning

* Fixed -Wformat warnings

In one case also removed a `z` character. There was a `z%d` that I think was supposed to be `%zd`

* Fixed -Wshorten-64-to-32 warnings

* Fixed -Wself-assign warnings

* Fixed -Wreserved-id-macro warnings

* Commit format changes from clang-format, clang version 10.0.1.

* Fixed -Wself-assign warnings

* Fixed -Wunused-local-typedef warning

* Fixed -Wformat warnings

In two cases also removed a `z` character. There was a `z%d` that was supposed to be `%zd`.

* Fixed -Wshorten-64-to-32 warnings

* Fixed -Wreserved-id-macro warnings

* Fixed -Wself-assign warnings

* Format source.

* Remove blank lines to pass format check.

Co-authored-by: Larry Knox <lrknox@hdfgroup.org>

* Changes found during merge to 1.12 (#414)

* OESS-98 convert plugin option to FetchContent, add tests

* Fixes for pkcfg files because of plugin option

* OESS-98 fix tools test for plugins

* Keep doxygen comments under 100 chars long - format hint

* Whitespace

* HDFFV-11144 - Reclassify CMake messages

* HDFFV-11099/11100 added help text

* Reworked switch statement to compare string instead

* Fix typo

* Update CDash mode

* Correct name of threadsafe

* Correct option name

* Undo accidental commit

* Note LLVM 10 to 11 format default changes

* Update format plugin

* Undo clang-format version 11 changes

* One more correction

* Update supported platforms

* Revert whitespace changes

* Correct whitespace

* Changes from PR#3

* HDFFV-11213 added option to control gcc10 warnings diagnostics

* HDFFV-11212 Use the new references correctly in JNI utility and tests

* format source

* Fix typo

* Add new test file

* HDFFV-11212 - update test and remove unused arg

* Minor non-space formatting changes

* Use H5I_INVALID_ID instead of "-1"

* source formatting

* add missing testfile, update jni function

* Undo commit of debug code

* remove mislocated file

* Fix h5repack test for handling of fapls and id close

* Update h5diff test files usage text

* HDFFV-11212 add new ref tests for JNI export dataset

* src format update

* Remove blank line typo

* src format typo

* long double requires %Lg

* Another long double foramt specifer S.B. %Lg

* issue with t128bit test

* Windows issue with h5dump and type.

* Fix review issues

* refactor function nesting and fix error checks

* format fixes

* Remove untested functions and javadoc quiet comments

* Restore TRY block.

* Change string append errors to memory exception

* revert to H5_JNI_FATAL_ERROR - support functions need work

* Add assertion error for h5util functions

* remove duplicate function

* format fix

* Revert HD function error handling

* Update copyright comments

* GH #386 java folder copyright corrections

* Whitespace

* GH #359 implement and fix tools 1.6 API usage

* remove excessive comments

* Flip inits to correct ifdef section

* rework ifdef to be simpler

* format issue

* Reformat ifdef inits

* remove static attribute

* format compliance

* Update names

* Revert because logic relies on float not being int

* Changes noticed from creating merge of #412

* Double underscore change

* Correct compiler version variable used

* Remove header guard underscores

* Whitespace cleanup

* Align with "parallel fence" changes (#479)

* Small code updates and simplifications

* Committing clang-format changes

* Fix 'make installcheck' for parallel builds

Co-authored-by: github-actions <41898282+github-actions[bot]@users.noreply.github.com>

* File locks now work on Windows (#480)

* File locks now work on Windows

Uses LockFileEx() and UnlockFileEx(). Fixes HDFFV-10191 (partial).

* Committing clang-format changes

* Committing clang-format changes

* Fixes commenting in h5repack

* Reworks H5Fis_accessible()

H5Fis_accessible() created a new file handle and attempted to read
through it, which will fail when a file has been opened with an
exclusive lock on operating systems that have mandatory locks.

This change uses the same scheme we use in H5Fopen() to check if
the file is already open and only tries to read the file signature
if the file has not already been opened.

Also adds a test for this behavior.

* Committing clang-format changes

* Trivial change to force github to run actions

Co-authored-by: github-actions <41898282+github-actions[bot]@users.noreply.github.com>

* small edits (#481)

* fixed missed closing of a dataset

* fixed missed closing of a dataset

* fixed typo in error return

* Committing clang-format changes

* minor edits

* code format

* Committing clang-format changes

* code format

* minor edit

Co-authored-by: github-actions <41898282+github-actions[bot]@users.noreply.github.com>

* Adds an implementation for nanosleep on Windows (#483)

* Adds an implementation for nanosleep on Windows

* Committing clang-format changes

* Fix insane formatter issue

Co-authored-by: github-actions <41898282+github-actions[bot]@users.noreply.github.com>

* Updates HSYS_GOTO_ERROR to emit GetLastError() values on Win32 (#492)

* Committing clang-format changes

* Updates H5SYS_GOTO_ERROR to emit Win32's GetLastError()

* Committing clang-format changes

* Format source changes

Co-authored-by: github-actions <41898282+github-actions[bot]@users.noreply.github.com>

* Updates that allow accum SWMR tests to work on Windows (#493)

* Committing clang-format changes

* Updates the accum test to work on Windows

Uses CreateProcess() on Windows

* Source formatting

* Fix for Unix child result

* Fixes process return code bug on Windows

Co-authored-by: github-actions <41898282+github-actions[bot]@users.noreply.github.com>

* Disable long double tests and remove CMake flag groups (#494)

* OESS-98 convert plugin option to FetchContent, add tests

* Fixes for pkcfg files because of plugin option

* OESS-98 fix tools test for plugins

* Keep doxygen comments under 100 chars long - format hint

* Whitespace

* HDFFV-11144 - Reclassify CMake messages

* HDFFV-11099/11100 added help text

* Reworked switch statement to compare string instead

* Fix typo

* Update CDash mode

* Correct name of threadsafe

* Correct option name

* Undo accidental commit

* Note LLVM 10 to 11 format default changes

* Update format plugin

* Undo clang-format version 11 changes

* One more correction

* Update supported platforms

* Revert whitespace changes

* Correct whitespace

* Changes from PR#3

* HDFFV-11213 added option to control gcc10 warnings diagnostics

* HDFFV-11212 Use the new references correctly in JNI utility and tests

* format source

* Fix typo

* Add new test file

* HDFFV-11212 - update test and remove unused arg

* Minor non-space formatting changes

* Use H5I_INVALID_ID instead of "-1"

* source formatting

* add missing testfile, update jni function

* Undo commit of debug code

* remove mislocated file

* Fix h5repack test for handling of fapls and id close

* Update h5diff test files usage text

* HDFFV-11212 add new ref tests for JNI export dataset

* src format update

* Remove blank line typo

* src format typo

* long double requires %Lg

* Another long double foramt specifer S.B. %Lg

* issue with t128bit test

* Windows issue with h5dump and type.

* Fix review issues

* refactor function nesting and fix error checks

* format fixes

* Remove untested functions and javadoc quiet comments

* Restore TRY block.

* Change string append errors to memory exception

* revert to H5_JNI_FATAL_ERROR - support functions need work

* Add assertion error for h5util functions

* remove duplicate function

* format fix

* Revert HD function error handling

* Update copyright comments

* GH #386 java folder copyright corrections

* Whitespace

* GH #359 implement and fix tools 1.6 API usage

* remove excessive comments

* Flip inits to correct ifdef section

* rework ifdef to be simpler

* format issue

* Reformat ifdef inits

* remove static attribute

* format compliance

* Update names

* Revert because logic relies on float not being int

* Changes noticed from creating merge of #412

* Double underscore change

* Correct compiler version variable used

* Remove header guard underscores

* Whitespace cleanup

* Split format source and commit changes on repo push

* remove pre-split setting

* Change windows TS to use older VS.

* correct window os name

* HDFFV-11212 JNI export util and Javadoc

* Suggested review changes

* Another change found

* Committing clang-format changes

* HDFFV-11113 long double in tools

* HDFFV-11113 add note

* Disable long double tests for now

* HDFFV-11228 remove arbitrary CMake warning groups.

* Make each flag a string

Co-authored-by: github-actions <41898282+github-actions[bot]@users.noreply.github.com>

* Misc warning fixes (#495)

* Committing clang-format changes

* Misc warning fixes from Visual Studio

* Committing clang-format changes

* Fixes warnings in swmr.c test

* Committing clang-format changes

Co-authored-by: github-actions <41898282+github-actions[bot]@users.noreply.github.com>

* Removes support for pre-2015 Visual Studio (#496)

* Committing clang-format changes

* Removes work-around code for pre-2015 Visual Studio

HDF5 no longer provides an implementation for:

* <inttypes.h>
* snprintf and vsnprintf
* llround(f), lround(f), round(f)
* strtoll and strtoull
* va_copy
* struct timespec

Co-authored-by: github-actions <41898282+github-actions[bot]@users.noreply.github.com>

* Remove extra parameter from merge.

* Resolve missed merge conflict.

Co-authored-by: Gerd Heber <gheber@hdfgroup.org>
Co-authored-by: bljhdf <58825073+bljhdf@users.noreply.github.com>
Co-authored-by: H. Joe Lee <hyoklee@hdfgroup.org>
Co-authored-by: Quincey Koziol <quincey@koziol.cc>
Co-authored-by: Sean McBride <sean@rogue-research.com>
Co-authored-by: Dana Robinson <43805+derobins@users.noreply.github.com>
Co-authored-by: Allen Byrne <50328838+byrnHDF@users.noreply.github.com>
Co-authored-by: Quincey Koziol <koziol@lbl.gov>
Co-authored-by: github-actions <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: Scot Breitenfeld <brtnfld@hdfgroup.org>

12 files changed, 204 insertions, 403 deletions

diff --git a/src/H5AC.c b/src/H5AC.c
index ffdca78..2eadd21 100644
--- a/src/H5AC.c
+++ b/src/H5AC.c
@@ -350,19 +350,14 @@ H5AC_create(const H5F_t *f, H5AC_cache_config_t *config_ptr, H5AC_cache_image_co
         if (NULL == (aux_ptr->candidate_slist_ptr = H5SL_create(H5SL_TYPE_HADDR, NULL)))
             HGOTO_ERROR(H5E_CACHE, H5E_CANTCREATE, FAIL, "can't create candidate entry list")
 
-        if (aux_ptr != NULL)
-            if (aux_ptr->mpi_rank == 0)
-                f->shared->cache = H5C_create(H5AC__DEFAULT_MAX_CACHE_SIZE, H5AC__DEFAULT_MIN_CLEAN_SIZE,
-                                              (H5AC_NTYPES - 1), H5AC_class_s, H5AC__check_if_write_permitted,
-                                              TRUE, H5AC__log_flushed_entry, (void *)aux_ptr);
-            else
-                f->shared->cache =
-                    H5C_create(H5AC__DEFAULT_MAX_CACHE_SIZE, H5AC__DEFAULT_MIN_CLEAN_SIZE, (H5AC_NTYPES - 1),
-                               H5AC_class_s, H5AC__check_if_write_permitted, TRUE, NULL, (void *)aux_ptr);
+        if (aux_ptr->mpi_rank == 0)
+            f->shared->cache = H5C_create(H5AC__DEFAULT_MAX_CACHE_SIZE, H5AC__DEFAULT_MIN_CLEAN_SIZE,
+                                          (H5AC_NTYPES - 1), H5AC_class_s, H5AC__check_if_write_permitted,
+                                          TRUE, H5AC__log_flushed_entry, (void *)aux_ptr);
         else
             f->shared->cache =
                 H5C_create(H5AC__DEFAULT_MAX_CACHE_SIZE, H5AC__DEFAULT_MIN_CLEAN_SIZE, (H5AC_NTYPES - 1),
-                           H5AC_class_s, H5AC__check_if_write_permitted, TRUE, NULL, NULL);
+                           H5AC_class_s, H5AC__check_if_write_permitted, TRUE, NULL, (void *)aux_ptr);
     } /* end if */
     else {
 #endif /* H5_HAVE_PARALLEL */
diff --git a/src/H5ACmpio.c b/src/H5ACmpio.c
index 6bd40a7..ef85c6d 100644
--- a/src/H5ACmpio.c
+++ b/src/H5ACmpio.c
@@ -1272,7 +1272,7 @@ H5AC__propagate_and_apply_candidate_list(H5F_t *f)
         if (aux_ptr->write_done)
             (aux_ptr->write_done)();
 
-        /* to prevent "messages from the past" we must synchronize all
+        /* To prevent "messages from the past" we must synchronize all
          * processes again before we go on.
          */
         if (MPI_SUCCESS != (mpi_result = MPI_Barrier(aux_ptr->mpi_comm)))
@@ -1515,7 +1515,7 @@ H5AC__receive_and_apply_clean_list(H5F_t *f)
         HGOTO_ERROR(H5E_CACHE, H5E_CANTGET, FAIL, "can't receive clean list")
 
     if (num_entries > 0)
-        /* mark the indicated entries as clean */
+        /* Mark the indicated entries as clean */
         if (H5C_mark_entries_as_clean(f, num_entries, haddr_buf_ptr) < 0)
             HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "Can't mark entries clean.")
 
@@ -1901,28 +1901,22 @@ H5AC__rsp__p0_only__flush(H5F_t *f)
 
         /* Check for error on the write operation */
         if (result < 0)
-
             HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "Can't flush.")
 
         /* this code exists primarily for the test bed -- it allows us to
          * enforce POSIX semantics on the server that pretends to be a
          * file system in our parallel tests.
          */
-        if (aux_ptr->write_done) {
-
+        if (aux_ptr->write_done)
             (aux_ptr->write_done)();
-        }
     } /* end if */
 
     /* Propagate cleaned entries to other ranks. */
     if (H5AC__propagate_flushed_and_still_clean_entries_list(f) < 0)
-
         HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "Can't propagate clean entries list.")
 
 done:
-
     FUNC_LEAVE_NOAPI(ret_value)
-
 } /* H5AC__rsp__p0_only__flush() */
 
 /*-------------------------------------------------------------------------
diff --git a/src/H5C.c b/src/H5C.c
index 646b603..d8ffc1c 100644
--- a/src/H5C.c
+++ b/src/H5C.c
@@ -21,14 +21,8 @@
  *              things which exist on disk, and which may be
  *              unambiguously referenced by their disk addresses.
  *
- *              The code in this module was initially written in
- *        support of a complete re-write of the metadata cache
- *        in H5AC.c  However, other uses for the cache code
- *        suggested themselves, and thus this file was created
- *        in an attempt to support re-use.
- *
- *        For a detailed overview of the cache, please see the
- *        header comment for H5C_t in H5Cpkg.h.
+ *		For a detailed overview of the cache, please see the
+ *		header comment for H5C_t in H5Cpkg.h.
  *
  *-------------------------------------------------------------------------
  */
@@ -39,9 +33,7 @@
  *
  *    Code Changes:
  *
- *     - Remove extra functionality in H5C__flush_single_entry()?
- *
- *     - Change protect/unprotect to lock/unlock.
+ *	 - Change protect/unprotect to lock/unlock.
  *
  *     - Flush entries in increasing address order in
  *       H5C__make_space_in_cache().
@@ -53,18 +45,9 @@
  *       I/O overhead.  Can't do this just yet as some entries are not
  *       contiguous.  Do this in parallel only or in serial as well?
  *
- *     - Create MPI type for dirty objects when flushing in parallel.
- *
- *     - Now that TBBT routines aren't used, fix nodes in memory to
- *         point directly to the skip list node from the LRU list, eliminating
- *         skip list lookups when evicting objects from the cache.
- *
- *    Tests:
- *
- *     - Trim execution time.  (This is no longer a major issue with the
- *       shift from the TBBT to a hash table for indexing.)
- *
- *     - Add random tests.
+ *	 - Fix nodes in memory to point directly to the skip list node from
+ *         the LRU list, eliminating skip list lookups when evicting objects
+ *         from the cache.
  *
  **************************************************************************/
 
@@ -6650,9 +6633,7 @@ H5C__flush_single_entry(H5F_t *f, H5C_cache_entry_t *entry_ptr, unsigned flags)
                 }
 
                 if (H5F_block_write(f, mem_type, entry_ptr->addr, entry_ptr->size, entry_ptr->image_ptr) < 0)
-
                     HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "Can't write image to file")
-
 #ifdef H5_HAVE_PARALLEL
             }
 #endif /* H5_HAVE_PARALLEL */
diff --git a/src/H5Cmpio.c b/src/H5Cmpio.c
index 7a5c630..66c6601 100644
--- a/src/H5Cmpio.c
+++ b/src/H5Cmpio.c
@@ -154,19 +154,12 @@ static herr_t H5C__flush_candidates_in_ring(H5F_t *f, H5C_ring_t ring, unsigned
  * Programmer:  John Mainzer
  *              3/17/10
  *
- * Changes:     Updated sanity checks to allow for the possibility that
- *              the slist is disabled.
- *                                               JRM -- 8/3/20
- *
  *-------------------------------------------------------------------------
  */
 herr_t
 H5C_apply_candidate_list(H5F_t *f, H5C_t *cache_ptr, unsigned num_candidates, haddr_t *candidates_list_ptr,
                          int mpi_rank, int mpi_size)
 {
-    int                i;
-    int                m;
-    unsigned           n;
     unsigned           first_entry_to_flush;
     unsigned           last_entry_to_flush;
     unsigned           total_entries_to_clear     = 0;
@@ -176,15 +169,13 @@ H5C_apply_candidate_list(H5F_t *f, H5C_t *cache_ptr, unsigned num_candidates, ha
     unsigned           entries_to_clear[H5C_RING_NTYPES];
     haddr_t            addr;
     H5C_cache_entry_t *entry_ptr = NULL;
-
 #if H5C_DO_SANITY_CHECKS
     haddr_t last_addr;
 #endif /* H5C_DO_SANITY_CHECKS */
-
 #if H5C_APPLY_CANDIDATE_LIST__DEBUG
     char tbl_buf[1024];
 #endif /* H5C_APPLY_CANDIDATE_LIST__DEBUG */
-
+    unsigned m, n;
     unsigned u;                   /* Local index variable */
     herr_t   ret_value = SUCCEED; /* Return value */
 
@@ -226,9 +217,7 @@ H5C_apply_candidate_list(H5F_t *f, H5C_t *cache_ptr, unsigned num_candidates, ha
     } /* end if */
 
     n = num_candidates / (unsigned)mpi_size;
-    if (num_candidates % (unsigned)mpi_size > INT_MAX)
-        HGOTO_ERROR(H5E_DATASET, H5E_BADVALUE, FAIL, "m overflow")
-    m = (int)(num_candidates % (unsigned)mpi_size);
+    m = num_candidates % (unsigned)mpi_size;
 
     if (NULL ==
         (candidate_assignment_table = (unsigned *)H5MM_malloc(sizeof(unsigned) * (size_t)(mpi_size + 1))))
@@ -239,31 +228,31 @@ H5C_apply_candidate_list(H5F_t *f, H5C_t *cache_ptr, unsigned num_candidates, ha
     candidate_assignment_table[mpi_size] = num_candidates;
 
     if (m == 0) { /* mpi_size is an even divisor of num_candidates */
-        for (i = 1; i < mpi_size; i++)
-            candidate_assignment_table[i] = candidate_assignment_table[i - 1] + n;
+        for (u = 1; u < (unsigned)mpi_size; u++)
+            candidate_assignment_table[u] = candidate_assignment_table[u - 1] + n;
     } /* end if */
     else {
-        for (i = 1; i <= m; i++)
-            candidate_assignment_table[i] = candidate_assignment_table[i - 1] + n + 1;
+        for (u = 1; u <= m; u++)
+            candidate_assignment_table[u] = candidate_assignment_table[u - 1] + n + 1;
 
         if (num_candidates < (unsigned)mpi_size) {
-            for (i = m + 1; i < mpi_size; i++)
-                candidate_assignment_table[i] = num_candidates;
+            for (u = m + 1; u < (unsigned)mpi_size; u++)
+                candidate_assignment_table[u] = num_candidates;
         } /* end if */
         else {
-            for (i = m + 1; i < mpi_size; i++)
-                candidate_assignment_table[i] = candidate_assignment_table[i - 1] + n;
+            for (u = m + 1; u < (unsigned)mpi_size; u++)
+                candidate_assignment_table[u] = candidate_assignment_table[u - 1] + n;
         } /* end else */
     }     /* end else */
     HDassert((candidate_assignment_table[mpi_size - 1] + n) == num_candidates);
 
 #if H5C_DO_SANITY_CHECKS
     /* Verify that the candidate assignment table has the expected form */
-    for (i = 1; i < mpi_size - 1; i++) {
+    for (u = 1; u < (unsigned)(mpi_size - 1); u++) {
         unsigned a, b;
 
-        a = candidate_assignment_table[i] - candidate_assignment_table[i - 1];
-        b = candidate_assignment_table[i + 1] - candidate_assignment_table[i];
+        a = candidate_assignment_table[u] - candidate_assignment_table[u - 1];
+        b = candidate_assignment_table[u + 1] - candidate_assignment_table[u];
 
         HDassert(n + 1 >= a);
         HDassert(a >= b);
@@ -275,11 +264,11 @@ H5C_apply_candidate_list(H5F_t *f, H5C_t *cache_ptr, unsigned num_candidates, ha
     last_entry_to_flush  = candidate_assignment_table[mpi_rank + 1] - 1;
 
 #if H5C_APPLY_CANDIDATE_LIST__DEBUG
-    for (i = 0; i < 1024; i++)
-        tbl_buf[i] = '\0';
+    for (u = 0; u < 1024; u++)
+        tbl_buf[u] = '\0';
     HDsprintf(&(tbl_buf[0]), "candidate assignment table = ");
-    for (i = 0; i <= mpi_size; i++)
-        HDsprintf(&(tbl_buf[HDstrlen(tbl_buf)]), " %u", candidate_assignment_table[i]);
+    for (u = 0; u <= (unsigned)mpi_size; u++)
+        HDsprintf(&(tbl_buf[HDstrlen(tbl_buf)]), " %u", candidate_assignment_table[u]);
     HDsprintf(&(tbl_buf[HDstrlen(tbl_buf)]), "\n");
     HDfprintf(stdout, "%s", tbl_buf);
 
@@ -354,9 +343,9 @@ H5C_apply_candidate_list(H5F_t *f, H5C_t *cache_ptr, unsigned num_candidates, ha
 #if H5C_DO_SANITY_CHECKS
     m = 0;
     n = 0;
-    for (i = 0; i < H5C_RING_NTYPES; i++) {
-        m += (int)entries_to_flush[i];
-        n += entries_to_clear[i];
+    for (u = 0; u < H5C_RING_NTYPES; u++) {
+        m += entries_to_flush[u];
+        n += entries_to_clear[u];
     } /* end if */
 
     HDassert((unsigned)m == total_entries_to_flush);
@@ -957,10 +946,8 @@ H5C__collective_write(H5F_t *f)
     int *            length_array = NULL;
     MPI_Aint *       buf_array    = NULL;
     MPI_Aint *       offset_array = NULL;
-    MPI_Datatype     btype;
-    hbool_t          btype_created = FALSE;
-    MPI_Datatype     ftype;
-    hbool_t          ftype_created = FALSE;
+    MPI_Datatype     btype        = MPI_BYTE;
+    MPI_Datatype     ftype        = MPI_BYTE;
     int              mpi_code;
     char             unused = 0; /* Unused, except for non-NULL pointer value */
     size_t           buf_count;
@@ -1032,7 +1019,6 @@ H5C__collective_write(H5F_t *f)
         if (MPI_SUCCESS !=
             (mpi_code = MPI_Type_create_hindexed(count, length_array, buf_array, MPI_BYTE, &btype)))
             HMPI_GOTO_ERROR(FAIL, "MPI_Type_create_hindexed failed", mpi_code)
-        btype_created = TRUE;
         if (MPI_SUCCESS != (mpi_code = MPI_Type_commit(&btype)))
             HMPI_GOTO_ERROR(FAIL, "MPI_Type_commit failed", mpi_code)
 
@@ -1040,7 +1026,6 @@ H5C__collective_write(H5F_t *f)
         if (MPI_SUCCESS !=
             (mpi_code = MPI_Type_create_hindexed(count, length_array, offset_array, MPI_BYTE, &ftype)))
             HMPI_GOTO_ERROR(FAIL, "MPI_Type_create_hindexed failed", mpi_code)
-        ftype_created = TRUE;
         if (MPI_SUCCESS != (mpi_code = MPI_Type_commit(&ftype)))
             HMPI_GOTO_ERROR(FAIL, "MPI_Type_commit failed", mpi_code)
 
@@ -1048,10 +1033,6 @@ H5C__collective_write(H5F_t *f)
         buf_count = 1;
     } /* end if */
     else {
-        /* Pass trivial buf type, file type to the file driver */
-        btype = MPI_BYTE;
-        ftype = MPI_BYTE;
-
         /* Set non-NULL pointer for I/O operation */
         base_buf = &unused;
 
@@ -1074,9 +1055,9 @@ done:
     offset_array = (MPI_Aint *)H5MM_xfree(offset_array);
 
     /* Free MPI Types */
-    if (btype_created && MPI_SUCCESS != (mpi_code = MPI_Type_free(&btype)))
+    if (MPI_BYTE != btype && MPI_SUCCESS != (mpi_code = MPI_Type_free(&btype)))
         HMPI_DONE_ERROR(FAIL, "MPI_Type_free failed", mpi_code)
-    if (ftype_created && MPI_SUCCESS != (mpi_code = MPI_Type_free(&ftype)))
+    if (MPI_BYTE != ftype && MPI_SUCCESS != (mpi_code = MPI_Type_free(&ftype)))
         HMPI_DONE_ERROR(FAIL, "MPI_Type_free failed", mpi_code)
 
     /* Reset transfer mode in API context, if changed */
diff --git a/src/H5Eprivate.h b/src/H5Eprivate.h
index 58010a3..c3c440f 100644
--- a/src/H5Eprivate.h
+++ b/src/H5Eprivate.h
@@ -111,6 +111,7 @@ typedef struct H5E_t H5E_t;
 /* Retrieve the error code description string and push it onto the error
  * stack.
  */
+#ifndef H5_HAVE_WIN32_API
 #define HSYS_DONE_ERROR(majorcode, minorcode, retcode, str)                                                  \
     {                                                                                                        \
         int myerrno = errno;                                                                                 \
@@ -129,6 +130,35 @@ typedef struct H5E_t H5E_t;
         HGOTO_ERROR(majorcode, minorcode, retcode, "%s, errno = %d, error message = '%s'", str, myerrno,     \
                     HDstrerror(myerrno));                                                                    \
     }
+#else /* H5_HAVE_WIN32_API */
+/* On Windows we also emit the result of GetLastError(). This call returns a DWORD, which is always a
+ * 32-bit unsigned type. Note that on Windows, either errno or GetLastError() (but probably not both) will
+ * be useful depending on whether a C/POSIX or Win32 call failed. The other value will likely be zero,
+ * though I wouldn't count on that.
+ */
+#define HSYS_DONE_ERROR(majorcode, minorcode, retcode, str)                                                  \
+    {                                                                                                        \
+        int   myerrno   = errno;                                                                             \
+        DWORD win_error = GetLastError();                                                                    \
+        /* Other projects may rely on the description format to get the errno and any changes should be      \
+         * considered as an API change                                                                       \
+         */                                                                                                  \
+        HDONE_ERROR(majorcode, minorcode, retcode,                                                           \
+                    "%s, errno = %d, error message = '%s', Win32 GetLastError() = %" PRIu32 "", str,         \
+                    myerrno, HDstrerror(myerrno), win_error);                                                \
+    }
+#define HSYS_GOTO_ERROR(majorcode, minorcode, retcode, str)                                                  \
+    {                                                                                                        \
+        int   myerrno   = errno;                                                                             \
+        DWORD win_error = GetLastError();                                                                    \
+        /* Other projects may rely on the description format to get the errno and any changes should be      \
+         * considered as an API change                                                                       \
+         */                                                                                                  \
+        HGOTO_ERROR(majorcode, minorcode, retcode,                                                           \
+                    "%s, errno = %d, error message = '%s', Win32 GetLastError() = %" PRIu32 "", str,         \
+                    myerrno, HDstrerror(myerrno), win_error);                                                \
+    }
+#endif /* H5_HAVE_WIN32_API */
 
 #ifdef H5_HAVE_PARALLEL
 /*
diff --git a/src/H5FDmpio.c b/src/H5FDmpio.c
index c167acc..576120b 100644
--- a/src/H5FDmpio.c
+++ b/src/H5FDmpio.c
@@ -750,18 +750,18 @@ done:
 static H5FD_t *
 H5FD__mpio_open(const char *name, unsigned flags, hid_t fapl_id, haddr_t H5_ATTR_UNUSED maxaddr)
 {
-    H5FD_mpio_t *   file = NULL;
-    MPI_File        fh;
-    hbool_t         file_opened = FALSE; /* Flag to indicate that the file was successfully opened */
-    int             mpi_amode;
-    int             mpi_rank; /* MPI rank of this process */
-    int             mpi_size; /* Total number of MPI processes */
-    int             mpi_code; /* MPI return code */
-    MPI_Offset      size;
-    H5P_genplist_t *plist; /* Property list pointer */
-    MPI_Comm        comm      = MPI_COMM_NULL;
-    MPI_Info        info      = MPI_INFO_NULL;
-    H5FD_t *        ret_value = NULL; /* Return value */
+    H5FD_mpio_t *   file = NULL;          /* VFD File struct for new file */
+    H5P_genplist_t *plist;                /* Property list pointer */
+    MPI_Comm        comm = MPI_COMM_NULL; /* MPI Communicator, from plist */
+    MPI_Info        info = MPI_INFO_NULL; /* MPI Info, from plist */
+    MPI_File        fh;                   /* MPI file handle */
+    hbool_t         file_opened = FALSE;  /* Flag to indicate that the file was successfully opened */
+    int             mpi_amode;            /* MPI file access flags */
+    int             mpi_rank = INT_MAX;   /* MPI rank of this process */
+    int             mpi_size;             /* Total number of MPI processes */
+    int             mpi_code;             /* MPI return code */
+    MPI_Offset      file_size;            /* File size (of existing files) */
+    H5FD_t *        ret_value = NULL;     /* Return value */
 
     FUNC_ENTER_STATIC
 
@@ -781,6 +781,12 @@ H5FD__mpio_open(const char *name, unsigned flags, hid_t fapl_id, haddr_t H5_ATTR
     if (H5P_get(plist, H5F_ACS_MPI_PARAMS_INFO_NAME, &info) < 0)
         HGOTO_ERROR(H5E_VFL, H5E_CANTGET, NULL, "can't get MPI info object")
 
+    /* Get the MPI rank of this process and the total number of processes */
+    if (MPI_SUCCESS != (mpi_code = MPI_Comm_rank(comm, &mpi_rank)))
+        HMPI_GOTO_ERROR(NULL, "MPI_Comm_rank failed", mpi_code)
+    if (MPI_SUCCESS != (mpi_code = MPI_Comm_size(comm, &mpi_size)))
+        HMPI_GOTO_ERROR(NULL, "MPI_Comm_size failed", mpi_code)
+
     /* Convert HDF5 flags to MPI-IO flags */
     /* Some combinations are illegal; let MPI-IO figure it out */
     mpi_amode = (flags & H5F_ACC_RDWR) ? MPI_MODE_RDWR : MPI_MODE_RDONLY;
@@ -810,12 +816,6 @@ H5FD__mpio_open(const char *name, unsigned flags, hid_t fapl_id, haddr_t H5_ATTR
         HMPI_GOTO_ERROR(NULL, "MPI_File_open failed", mpi_code)
     file_opened = TRUE;
 
-    /* Get the MPI rank of this process and the total number of processes */
-    if (MPI_SUCCESS != (mpi_code = MPI_Comm_rank(comm, &mpi_rank)))
-        HMPI_GOTO_ERROR(NULL, "MPI_Comm_rank failed", mpi_code)
-    if (MPI_SUCCESS != (mpi_code = MPI_Comm_size(comm, &mpi_size)))
-        HMPI_GOTO_ERROR(NULL, "MPI_Comm_size failed", mpi_code)
-
     /* Build the return value and initialize it */
     if (NULL == (file = (H5FD_mpio_t *)H5MM_calloc(sizeof(H5FD_mpio_t))))
         HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed")
@@ -826,17 +826,16 @@ H5FD__mpio_open(const char *name, unsigned flags, hid_t fapl_id, haddr_t H5_ATTR
     file->mpi_size = mpi_size;
 
     /* Only processor p0 will get the filesize and broadcast it. */
-    if (mpi_rank == 0) {
-        if (MPI_SUCCESS != (mpi_code = MPI_File_get_size(fh, &size)))
+    if (mpi_rank == 0)
+        if (MPI_SUCCESS != (mpi_code = MPI_File_get_size(fh, &file_size)))
             HMPI_GOTO_ERROR(NULL, "MPI_File_get_size failed", mpi_code)
-    } /* end if */
 
     /* Broadcast file size */
-    if (MPI_SUCCESS != (mpi_code = MPI_Bcast(&size, (int)sizeof(MPI_Offset), MPI_BYTE, 0, comm)))
+    if (MPI_SUCCESS != (mpi_code = MPI_Bcast(&file_size, (int)sizeof(MPI_Offset), MPI_BYTE, 0, comm)))
         HMPI_GOTO_ERROR(NULL, "MPI_Bcast failed", mpi_code)
 
     /* Determine if the file should be truncated */
-    if (size && (flags & H5F_ACC_TRUNC)) {
+    if (file_size && (flags & H5F_ACC_TRUNC)) {
         if (MPI_SUCCESS != (mpi_code = MPI_File_set_size(fh, (MPI_Offset)0)))
             HMPI_GOTO_ERROR(NULL, "MPI_File_set_size failed", mpi_code)
 
@@ -845,11 +844,11 @@ H5FD__mpio_open(const char *name, unsigned flags, hid_t fapl_id, haddr_t H5_ATTR
             HMPI_GOTO_ERROR(NULL, "MPI_Barrier failed", mpi_code)
 
         /* File is zero size now */
-        size = 0;
+        file_size = 0;
     } /* end if */
 
     /* Set the size of the file (from library's perspective) */
-    file->eof       = H5FD_mpi_MPIOff_to_haddr(size);
+    file->eof       = H5FD_mpi_MPIOff_to_haddr(file_size);
     file->local_eof = file->eof;
 
     /* Set return value */
@@ -906,7 +905,7 @@ H5FD__mpio_close(H5FD_t *_file)
     HDassert(H5FD_MPIO == file->pub.driver_id);
 
     /* MPI_File_close sets argument to MPI_FILE_NULL */
-    if (MPI_SUCCESS != (mpi_code = MPI_File_close(&(file->f) /*in,out*/)))
+    if (MPI_SUCCESS != (mpi_code = MPI_File_close(&(file->f))))
         HMPI_GOTO_ERROR(FAIL, "MPI_File_close failed", mpi_code)
 
     /* Clean up other stuff */
@@ -1228,8 +1227,10 @@ H5FD__mpio_read(H5FD_t *_file, H5FD_mem_t H5_ATTR_UNUSED type, hid_t H5_ATTR_UNU
                 if (MPI_SUCCESS != (mpi_code = MPI_Bcast(buf, size_i, buf_type, 0, file->comm)))
                     HMPI_GOTO_ERROR(FAIL, "MPI_Bcast failed", mpi_code)
             } /* end if */
-            else if (MPI_SUCCESS !=
-                     (mpi_code = MPI_File_read_at_all(file->f, mpi_off, buf, size_i, buf_type, &mpi_stat)))
+            else
+                /* Perform collective read operation */
+                if (MPI_SUCCESS !=
+                    (mpi_code = MPI_File_read_at_all(file->f, mpi_off, buf, size_i, buf_type, &mpi_stat)))
                 HMPI_GOTO_ERROR(FAIL, "MPI_File_read_at_all failed", mpi_code)
         } /* end if */
         else {
@@ -1238,6 +1239,7 @@ H5FD__mpio_read(H5FD_t *_file, H5FD_mem_t H5_ATTR_UNUSED type, hid_t H5_ATTR_UNU
                 HDfprintf(stdout, "%s: doing MPI independent IO\n", FUNC);
 #endif
 
+            /* Perform independent read operation */
             if (MPI_SUCCESS !=
                 (mpi_code = MPI_File_read_at(file->f, mpi_off, buf, size_i, buf_type, &mpi_stat)))
                 HMPI_GOTO_ERROR(FAIL, "MPI_File_read_at failed", mpi_code)
@@ -1250,7 +1252,9 @@ H5FD__mpio_read(H5FD_t *_file, H5FD_mem_t H5_ATTR_UNUSED type, hid_t H5_ATTR_UNU
                                                          H5FD_mpi_native_g, file->info)))
             HMPI_GOTO_ERROR(FAIL, "MPI_File_set_view failed", mpi_code)
     } /* end if */
-    else if (MPI_SUCCESS != (mpi_code = MPI_File_read_at(file->f, mpi_off, buf, size_i, buf_type, &mpi_stat)))
+    else
+        /* Perform independent read operation */
+        if (MPI_SUCCESS != (mpi_code = MPI_File_read_at(file->f, mpi_off, buf, size_i, buf_type, &mpi_stat)))
         HMPI_GOTO_ERROR(FAIL, "MPI_File_read_at failed", mpi_code)
 
     /* Only retrieve bytes read if this rank _actually_ participated in I/O */
@@ -1442,6 +1446,7 @@ H5FD__mpio_write(H5FD_t *_file, H5FD_mem_t type, hid_t H5_ATTR_UNUSED dxpl_id, h
             if (H5FD_mpio_Debug[(int)'w'])
                 HDfprintf(stdout, "%s: doing MPI collective IO\n", FUNC);
 #endif
+            /* Perform collective write operation */
             if (MPI_SUCCESS !=
                 (mpi_code = MPI_File_write_at_all(file->f, mpi_off, buf, size_i, buf_type, &mpi_stat)))
                 HMPI_GOTO_ERROR(FAIL, "MPI_File_write_at_all failed", mpi_code)
@@ -1454,6 +1459,7 @@ H5FD__mpio_write(H5FD_t *_file, H5FD_mem_t type, hid_t H5_ATTR_UNUSED dxpl_id, h
             if (H5FD_mpio_Debug[(int)'w'])
                 HDfprintf(stdout, "%s: doing MPI independent IO\n", FUNC);
 #endif
+            /* Perform independent write operation */
             if (MPI_SUCCESS !=
                 (mpi_code = MPI_File_write_at(file->f, mpi_off, buf, size_i, buf_type, &mpi_stat)))
                 HMPI_GOTO_ERROR(FAIL, "MPI_File_write_at failed", mpi_code)
@@ -1464,8 +1470,9 @@ H5FD__mpio_write(H5FD_t *_file, H5FD_mem_t type, hid_t H5_ATTR_UNUSED dxpl_id, h
                                                          H5FD_mpi_native_g, file->info)))
             HMPI_GOTO_ERROR(FAIL, "MPI_File_set_view failed", mpi_code)
     } /* end if */
-    else if (MPI_SUCCESS !=
-             (mpi_code = MPI_File_write_at(file->f, mpi_off, buf, size_i, buf_type, &mpi_stat)))
+    else
+        /* Perform independent write operation */
+        if (MPI_SUCCESS != (mpi_code = MPI_File_write_at(file->f, mpi_off, buf, size_i, buf_type, &mpi_stat)))
         HMPI_GOTO_ERROR(FAIL, "MPI_File_write_at failed", mpi_code)
 
         /* How many bytes were actually written? */
@@ -1503,9 +1510,9 @@ H5FD__mpio_write(H5FD_t *_file, H5FD_mem_t type, hid_t H5_ATTR_UNUSED dxpl_id, h
         file->local_eof = addr + (haddr_t)bytes_written;
 
 done:
-    if (derived_type) {
+    if (derived_type)
         MPI_Type_free(&buf_type);
-    }
+
 #ifdef H5FDmpio_DEBUG
     if (H5FD_mpio_Debug[(int)'t'])
         HDfprintf(stdout, "%s: Leaving, proc %d: ret_value = %d\n", FUNC, file->mpi_rank, ret_value);
@@ -1565,13 +1572,14 @@ done:
  *
  *              This is a little sticky in the mpio case, as it is not
  *              easy for us to track the current EOF by extracting it from
- *              write calls.
+ *              write calls, since other ranks could have written to the
+ *              file beyond the local EOF.
  *
- *              Instead, we first check to see if the eoa has changed since
+ *              Instead, we first check to see if the EOA has changed since
  *              the last call to this function.  If it has, we call
  *              MPI_File_get_size() to determine the current EOF, and
  *              only call MPI_File_set_size() if this value disagrees
- *              with the current eoa.
+ *              with the current EOA.
  *
  * Return:      SUCCEED/FAIL
  *
@@ -1633,7 +1641,7 @@ H5FD__mpio_truncate(H5FD_t *_file, hid_t H5_ATTR_UNUSED dxpl_id, hbool_t H5_ATTR
         if (H5FD_mpi_haddr_to_MPIOff(file->eoa, &needed_eof) < 0)
             HGOTO_ERROR(H5E_INTERNAL, H5E_BADRANGE, FAIL, "cannot convert from haddr_t to MPI_Offset")
 
-        /* eoa != eof.  Set eof to eoa */
+        /* EOA != EOF.  Set EOF to EOA */
         if (size != needed_eof) {
             /* Extend the file's size */
             if (MPI_SUCCESS != (mpi_code = MPI_File_set_size(file->f, needed_eof)))
@@ -1745,5 +1753,4 @@ H5FD__mpio_communicator(const H5FD_t *_file)
 
     FUNC_LEAVE_NOAPI(file->comm)
 } /* end H5FD__mpio_communicator() */
-
 #endif /* H5_HAVE_PARALLEL */
diff --git a/src/H5Fint.c b/src/H5Fint.c
index 6922948..a8039b2 100644
--- a/src/H5Fint.c
+++ b/src/H5Fint.c
@@ -81,6 +81,7 @@ static herr_t H5F__build_name(const char *prefix, const char *file_name, char **
 static char * H5F__getenv_prefix_name(char **env_prefix /*in,out*/);
 static H5F_t *H5F__new(H5F_shared_t *shared, unsigned flags, hid_t fcpl_id, hid_t fapl_id, H5FD_t *lf);
 static herr_t H5F__check_if_using_file_locks(H5P_genplist_t *fapl, hbool_t *use_file_locking);
+static herr_t H5F__dest(H5F_t *f, hbool_t flush);
 static herr_t H5F__build_actual_name(const H5F_t *f, const H5P_genplist_t *fapl, const char *name,
                                      char ** /*out*/ actual_name);
 static herr_t H5F__flush_phase1(H5F_t *f);
@@ -1057,9 +1058,10 @@ done:
 htri_t
 H5F__is_hdf5(const char *name, hid_t fapl_id)
 {
-    H5FD_t *file      = NULL;        /* Low-level file struct                    */
-    haddr_t sig_addr  = HADDR_UNDEF; /* Addess of hdf5 file signature            */
-    htri_t  ret_value = FAIL;        /* Return value                             */
+    H5FD_t *      file      = NULL;        /* Low-level file struct            */
+    H5F_shared_t *shared    = NULL;        /* Shared part of file              */
+    haddr_t       sig_addr  = HADDR_UNDEF; /* Addess of hdf5 file signature    */
+    htri_t        ret_value = FAIL;        /* Return value                     */
 
     FUNC_ENTER_PACKAGE
 
@@ -1070,10 +1072,20 @@ H5F__is_hdf5(const char *name, hid_t fapl_id)
     if (NULL == (file = H5FD_open(name, H5F_ACC_RDONLY, fapl_id, HADDR_UNDEF)))
         HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, FAIL, "unable to open file")
 
-    /* The file is an hdf5 file if the hdf5 file signature can be found */
-    if (H5FD_locate_signature(file, &sig_addr) < 0)
-        HGOTO_ERROR(H5E_FILE, H5E_NOTHDF5, FAIL, "error while trying to locate file signature")
-    ret_value = (HADDR_UNDEF != sig_addr);
+    /* If the file is already open, it's an HDF5 file
+     *
+     * If the file is open with an exclusive lock on an operating system that enforces
+     * mandatory file locks (like Windows), creating a new file handle and attempting
+     * to read through it will fail so we have to try this first.
+     */
+    if ((shared = H5F__sfile_search(file)) != NULL)
+        ret_value = TRUE;
+    else {
+        /* The file is an HDF5 file if the HDF5 file signature can be found */
+        if (H5FD_locate_signature(file, &sig_addr) < 0)
+            HGOTO_ERROR(H5E_FILE, H5E_NOTHDF5, FAIL, "error while trying to locate file signature")
+        ret_value = (HADDR_UNDEF != sig_addr);
+    }
 
 done:
     /* Close the file */
@@ -1369,12 +1381,12 @@ done:
  * Return:      SUCCEED/FAIL
  *-------------------------------------------------------------------------
  */
-herr_t
+static herr_t
 H5F__dest(H5F_t *f, hbool_t flush)
 {
     herr_t ret_value = SUCCEED; /* Return value */
 
-    FUNC_ENTER_PACKAGE
+    FUNC_ENTER_STATIC
 
     /* Sanity check */
     HDassert(f);
@@ -1783,7 +1795,7 @@ H5F_open(const char *name, unsigned flags, hid_t fcpl_id, hid_t fapl_id)
     FUNC_ENTER_NOAPI(NULL)
 
     /*
-     * If the driver has a `cmp' method then the driver is capable of
+     * If the driver has a 'cmp' method then the driver is capable of
      * determining when two file handles refer to the same file and the
      * library can insure that when the application opens a file twice
      * that the two handles coordinate their operations appropriately.
@@ -2502,11 +2514,6 @@ H5F_try_close(H5F_t *f, hbool_t *was_closed /*out*/)
         if (H5F__efc_try_close(f) < 0)
             HGOTO_ERROR(H5E_FILE, H5E_CANTRELEASE, FAIL, "can't attempt to close EFC")
 
-    /* Delay flush until the shared file struct is closed, in H5F__dest.  If the
-     * application called H5Fclose, it would have been flushed in that function
-     * (unless it will have been flushed in H5F__dest anyways).
-     */
-
     /* Destroy the H5F_t struct and decrement the reference count for the
      * shared H5F_shared_t struct. If the reference count for the H5F_shared_t
      * struct reaches zero then destroy it also.
@@ -3718,6 +3725,19 @@ H5F__start_swmr_write(H5F_t *f)
 
     setup = TRUE;
 
+    /* Place an advisory lock on the file */
+    if (H5F_USE_FILE_LOCKING(f)) {
+        /* Have to unlock on Windows as Win32 doesn't support changing the lock
+         * type (exclusive vs shared) with a second call.
+         */
+        if (H5FD_unlock(f->shared->lf) < 0) {
+            HGOTO_ERROR(H5E_FILE, H5E_CANTUNLOCKFILE, FAIL, "unable to unlock the file")
+        }
+        if (H5FD_lock(f->shared->lf, TRUE) < 0) {
+            HGOTO_ERROR(H5E_FILE, H5E_CANTLOCKFILE, FAIL, "unable to lock the file")
+        }
+    }
+
     /* Mark superblock as dirty */
     if (H5F_super_dirty(f) < 0)
         HGOTO_ERROR(H5E_FILE, H5E_CANTMARKDIRTY, FAIL, "unable to mark superblock as dirty")
diff --git a/src/H5Fmpi.c b/src/H5Fmpi.c
index 3991350..97bfefd 100644
--- a/src/H5Fmpi.c
+++ b/src/H5Fmpi.c
@@ -68,35 +68,6 @@
 /*******************/
 
 #ifdef H5_HAVE_PARALLEL
-
-/*-------------------------------------------------------------------------
- * Function:    H5F_get_mpi_handle
- *
- * Purpose:     Retrieves MPI File handle.
- *
- * Return:      Success:        The size (positive)
- *              Failure:        Negative
- *
- *-------------------------------------------------------------------------
- */
-herr_t
-H5F_get_mpi_handle(const H5F_t *f, MPI_File **f_handle)
-{
-    herr_t ret_value = SUCCEED;
-    hid_t  fapl_id   = H5I_INVALID_HID;
-
-    FUNC_ENTER_NOAPI(FAIL)
-
-    HDassert(f && f->shared);
-
-    /* Dispatch to driver */
-    if ((ret_value = H5FD_get_vfd_handle(f->shared->lf, fapl_id, (void **)f_handle)) < 0)
-        HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "can't get mpi file handle")
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5F_get_mpi_handle() */
-
 /*-------------------------------------------------------------------------
  * Function:    H5F_mpi_get_rank
  *
diff --git a/src/H5Fpkg.h b/src/H5Fpkg.h
index 371260d..087c9c9 100644
--- a/src/H5Fpkg.h
+++ b/src/H5Fpkg.h
@@ -405,7 +405,6 @@ H5_DLLVAR htri_t use_locks_env_g;
 /* General routines */
 H5_DLL herr_t H5F__post_open(H5F_t *f);
 H5_DLL H5F_t * H5F__reopen(H5F_t *f);
-H5_DLL herr_t  H5F__dest(H5F_t *f, hbool_t flush);
 H5_DLL herr_t  H5F__flush(H5F_t *f);
 H5_DLL htri_t  H5F__is_hdf5(const char *name, hid_t fapl_id);
 H5_DLL ssize_t H5F__get_file_image(H5F_t *f, void *buf_ptr, size_t buf_len);
diff --git a/src/H5Fprivate.h b/src/H5Fprivate.h
index 0c75cf0..5c5937b 100644
--- a/src/H5Fprivate.h
+++ b/src/H5Fprivate.h
@@ -955,7 +955,6 @@ H5_DLL herr_t H5F_eoa_dirty(H5F_t *f);
 
 /* Parallel I/O (i.e. MPI) related routines */
 #ifdef H5_HAVE_PARALLEL
-H5_DLL herr_t   H5F_get_mpi_handle(const H5F_t *f, MPI_File **f_handle);
 H5_DLL int      H5F_mpi_get_rank(const H5F_t *f);
 H5_DLL MPI_Comm H5F_mpi_get_comm(const H5F_t *f);
 H5_DLL int      H5F_shared_mpi_get_size(const H5F_shared_t *f_sh);
diff --git a/src/H5system.c b/src/H5system.c
index 53307a8..144e0bc 100644
--- a/src/H5system.c
+++ b/src/H5system.c
@@ -573,40 +573,14 @@ Wgetlogin(void)
 {
 
 #ifdef H5_HAVE_WINSOCK2_H
-    long bufferCount = WloginBuffer_count;
-    if (GetUserName(Wlogin_buffer, &bufferCount) == 0)
+    DWORD bufferCount = WloginBuffer_count;
+    if (GetUserName(Wlogin_buffer, &bufferCount) != 0)
         return (Wlogin_buffer);
     else
 #endif /* H5_HAVE_WINSOCK2_H */
         return NULL;
 }
 
-int
-c99_snprintf(char *str, size_t size, const char *format, ...)
-{
-    int     count;
-    va_list ap;
-
-    HDva_start(ap, format);
-    count = c99_vsnprintf(str, size, format, ap);
-    HDva_end(ap);
-
-    return count;
-}
-
-int
-c99_vsnprintf(char *str, size_t size, const char *format, va_list ap)
-{
-    int count = -1;
-
-    if (size != 0)
-        count = _vsnprintf_s(str, size, _TRUNCATE, format, ap);
-    if (count == -1)
-        count = _vscprintf(format, ap);
-
-    return count;
-}
-
 /*-------------------------------------------------------------------------
  * Function:    Wflock
  *
@@ -618,110 +592,45 @@ c99_vsnprintf(char *str, size_t size, const char *format, va_list ap)
  *-------------------------------------------------------------------------
  */
 int
-Wflock(int H5_ATTR_UNUSED fd, int H5_ATTR_UNUSED operation)
+Wflock(int fd, int operation)
 {
 
-/* This is a no-op while we implement a Win32 VFD */
-#if 0
-int
-Wflock(int fd, int operation) {
-
-    HANDLE          hFile;
-    DWORD           dwFlags = LOCKFILE_FAIL_IMMEDIATELY;
-    DWORD           dwReserved = 0;
-                    /* MAXDWORD for entire file */
-    DWORD           nNumberOfBytesToLockLow = MAXDWORD;
-    DWORD           nNumberOfBytesToLockHigh = MAXDWORD;
-                    /* Must initialize OVERLAPPED struct */
-    OVERLAPPED      overlapped = {0};
+    HANDLE hFile;
+    DWORD  dwFlags    = LOCKFILE_FAIL_IMMEDIATELY;
+    DWORD  dwReserved = 0;
+    /* MAXDWORD locks the entire file */
+    DWORD nNumberOfBytesToLockLow  = MAXDWORD;
+    DWORD nNumberOfBytesToLockHigh = MAXDWORD;
+    /* Must initialize OVERLAPPED struct */
+    OVERLAPPED overlapped = {0};
 
     /* Get Windows HANDLE */
-    hFile = _get_osfhandle(fd);
+    if (INVALID_HANDLE_VALUE == (hFile = (HANDLE)_get_osfhandle(fd)))
+        return -1;
 
     /* Convert to Windows flags */
-    if(operation & LOCK_EX)
+    if (operation & LOCK_EX)
         dwFlags |= LOCKFILE_EXCLUSIVE_LOCK;
 
     /* Lock or unlock */
-    if(operation & LOCK_UN)
-        if(0 == UnlockFileEx(hFile, dwReserved, nNumberOfBytesToLockLow,
-                            nNumberOfBytesToLockHigh, &overlapped))
-            return -1;
-    else
-        if(0 == LockFileEx(hFile, dwFlags, dwReserved, nNumberOfBytesToLockLow,
-                            nNumberOfBytesToLockHigh, &overlapped))
+    if (operation & LOCK_UN) {
+        if (0 ==
+            UnlockFileEx(hFile, dwReserved, nNumberOfBytesToLockLow, nNumberOfBytesToLockHigh, &overlapped)) {
+            /* Attempting to unlock an already unlocked file will fail and this can happen
+             * in H5Fstart_swmr_write(). For now, just ignore the "error" (error code: 0x9e / 158).
+             */
+            if (GetLastError() != 158)
+                return -1;
+        }
+    }
+    else {
+        if (0 == LockFileEx(hFile, dwFlags, dwReserved, nNumberOfBytesToLockLow, nNumberOfBytesToLockHigh,
+                            &overlapped))
             return -1;
-#endif /* 0 */
-    return 0;
-} /* end Wflock() */
+    }
 
-/*--------------------------------------------------------------------------
- * Function:    Wnanosleep
- *
- * Purpose:     Sleep for a given # of nanoseconds (Windows version)
- *
- * Return:      SUCCEED/FAIL
- *
- * Programmer:  Dana Robinson
- *              Fall 2016
- *--------------------------------------------------------------------------
- */
-int
-Wnanosleep(const struct timespec *req, struct timespec *rem)
-{
-    /* XXX: Currently just a placeholder */
     return 0;
-
-} /* end Wnanosleep() */
-
-/*-------------------------------------------------------------------------
- * Function:    Wllround, Wllroundf, Wlround, Wlroundf, Wround, Wroundf
- *
- * Purpose:     Wrapper function for round functions for use with VS2012
- *              and earlier.
- *
- * Return:      The rounded value that was passed in.
- *
- * Programmer:  Dana Robinson
- *              December 2016
- *
- *-------------------------------------------------------------------------
- */
-long long
-Wllround(double arg)
-{
-    return (long long)(arg < 0.0 ? HDceil(arg - 0.5) : HDfloor(arg + 0.5));
-}
-
-long long
-Wllroundf(float arg)
-{
-    return (long long)(arg < 0.0F ? HDceil(arg - 0.5F) : HDfloor(arg + 0.5F));
-}
-
-long
-Wlround(double arg)
-{
-    return (long)(arg < 0.0 ? HDceil(arg - 0.5) : HDfloor(arg + 0.5));
-}
-
-long
-Wlroundf(float arg)
-{
-    return (long)(arg < 0.0F ? HDceil(arg - 0.5F) : HDfloor(arg + 0.5F));
-}
-
-double
-Wround(double arg)
-{
-    return arg < 0.0 ? HDceil(arg - 0.5) : HDfloor(arg + 0.5);
-}
-
-float
-Wroundf(float arg)
-{
-    return (float)(arg < 0.0F ? HDceil(arg - 0.5F) : HDfloor(arg + 0.5F));
-}
+} /* end Wflock() */
 
 /*-------------------------------------------------------------------------
  * Function:     H5_get_utf16_str
@@ -1052,6 +961,9 @@ done:
  *
  * Purpose:     Sleep for a given # of nanoseconds
  *
+ *              Note that commodity hardware is probably going to have a
+ *              resolution of milliseconds, not nanoseconds.
+ *
  * Return:      SUCCEED/FAIL
  *
  * Programmer:  Quincey Koziol
@@ -1061,15 +973,26 @@ done:
 void
 H5_nanosleep(uint64_t nanosec)
 {
-    struct timespec sleeptime; /* Struct to hold time to sleep */
-
     FUNC_ENTER_NOAPI_NOINIT_NOERR
 
-    /* Set up time to sleep */
-    sleeptime.tv_sec  = 0;
-    sleeptime.tv_nsec = (long)nanosec;
+#ifdef H5_HAVE_WIN32_API
 
-    HDnanosleep(&sleeptime, NULL);
+    /* On Windows, Sleep() is in milliseconds. Passing 0 to Sleep()
+     * causes the thread to relinquish the rest of its time slice.
+     */
+    Sleep(nanosec / (1000 * 1000));
+
+#else
+    {
+        struct timespec sleeptime; /* Struct to hold time to sleep */
+
+        /* Set up time to sleep */
+        sleeptime.tv_sec  = 0;
+        sleeptime.tv_nsec = (long)nanosec;
+
+        HDnanosleep(&sleeptime, NULL);
+    }
+#endif
 
     FUNC_LEAVE_NOAPI_VOID
 } /* end H5_nanosleep() */
diff --git a/src/H5win32defs.h b/src/H5win32defs.h
index 8f3947a..88911b0 100644
--- a/src/H5win32defs.h
+++ b/src/H5win32defs.h
@@ -11,66 +11,18 @@
  * help@hdfgroup.org.                                                        *
  * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
-/* Programmer:  Scott Wegner
- *              June 3, 2008
- *
- * Purpose: This file is used to map HDF macros to Windows functions.  This
+/* Purpose: This file is used to map HDF macros to Windows functions.  This
  *          should get included H5private mappings, so as to override them.
  *          Any macro not mapped here, however, will receive a similar mapping
  *          inside H5private.h
  *
  */
-#ifndef H5_HAVE_INTTYPES_H
-/* The following definitions should be suitable for 64-bit Windows, which is
- * LLP64, and for 32-bit Windows, which is ILP32.  Those are the only
- * platforms where <inttypes.h> is likely to be missing.  VS2015 and later
- * *may* provide these definitions.
- */
-#ifdef _WIN64
-#define PRIdPTR "lld"
-#define PRIoPTR "llo"
-#define PRIuPTR "llu"
-#define PRIxPTR "llx"
-#define PRIXPTR "llX"
-#else /* _WIN64 */
-#define PRIdPTR "ld"
-#define PRIoPTR "lo"
-#define PRIuPTR "lu"
-#define PRIxPTR "lx"
-#define PRIXPTR "lX"
-#endif /* _WIN64 */
-
-#define PRId8   "d"
-#define PRIo8   "o"
-#define PRIu8   "u"
-#define PRIx8   "x"
-#define PRIX8   "X"
-#define PRId16  "d"
-#define PRIo16  "o"
-#define PRIu16  "u"
-#define PRIx16  "x"
-#define PRIX16  "X"
-#define PRId32  "d"
-#define PRIo32  "o"
-#define PRIu32  "u"
-#define PRIx32  "x"
-#define PRIX32  "X"
-#define PRId64  "lld"
-#define PRIo64  "llo"
-#define PRIu64  "llu"
-#define PRIx64  "llx"
-#define PRIX64  "llX"
-#define PRIdMAX "lld"
-#define PRIoMAX "llo"
-#define PRIuMAX "llu"
-#define PRIxMAX "llx"
-#define PRIXMAX "llX"
-#endif
 
-/*
- * _MSC_VER = 1900 VS2015
- * _MSC_VER = 1800 VS2013
- * _MSC_VER = 1700 VS2012
+/* _MSC_VER = 192x  VS2019
+ * _MSC_VER = 191x  VS2017
+ * _MSC_VER = 1900  VS2015
+ * _MSC_VER = 1800  VS2013
+ * _MSC_VER = 1700  VS2012
  */
 #ifdef H5_HAVE_WIN32_API
 
@@ -119,22 +71,8 @@ typedef __int64         h5_stat_size_t;
 
 #ifdef H5_HAVE_VISUAL_STUDIO
 
-#if (_MSC_VER < 1800)
-#ifndef H5_HAVE_STRTOLL
-#define HDstrtoll(S, R, N) _strtoi64(S, R, N)
-#endif /* H5_HAVE_STRTOLL */
-#ifndef H5_HAVE_STRTOULL
-#define HDstrtoull(S, R, N) _strtoui64(S, R, N)
-#endif /* H5_HAVE_STRTOULL */
-/* va_copy() does not exist on pre-2013 Visual Studio. Since va_lists are
- * just pointers into the stack in those CRTs, the usual work-around
- * is to just define the operation as a pointer copy.
- */
-#define HDva_copy(D, S) ((D) = (S))
-#endif /* MSC_VER < 1800 */
-
 /*
- * The (void*) cast just avoids a compiler warning in H5_HAVE_VISUAL_STUDIO
+ * The (void*) cast just avoids a compiler warning in MSVC
  */
 #define HDmemset(X, C, Z) memset((void *)(X), C, Z)
 
@@ -143,26 +81,6 @@ struct timezone {
     int tz_dsttime;
 };
 
-/* time.h before VS2015 does not include timespec */
-#if (_MSC_VER < 1900)
-struct timespec {
-    time_t tv_sec;  /* Seconds - >= 0 */
-    long   tv_nsec; /* Nanoseconds - [0, 999999999] */
-};
-#endif /* MSC_VER < 1900 */
-
-#if (_MSC_VER <= 1700)
-/* The isnan function needs underscore in VS2012 and earlier */
-#define HDisnan(X) _isnan(X)
-/* The round functions do not exist in VS2012 and earlier */
-#define HDllround(V)  Wllround(V)
-#define HDllroundf(V) Wllroundf(V)
-#define HDlround(V)   Wlround(V)
-#define HDlroundf(V)  Wlroundf(V)
-#define HDround(V)    Wround(V)
-#define HDroundf(V)   Wroundf(V)
-#endif /* MSC_VER < 1700 */
-
 #endif /* H5_HAVE_VISUAL_STUDIO */
 
 #ifdef __cplusplus
@@ -172,26 +90,11 @@ H5_DLL int    Wgettimeofday(struct timeval *tv, struct timezone *tz);
 H5_DLL int    Wsetenv(const char *name, const char *value, int overwrite);
 H5_DLL int    Wflock(int fd, int operation);
 H5_DLL char * Wgetlogin(void);
-H5_DLL int    c99_snprintf(char *str, size_t size, const char *format, ...);
-H5_DLL int    c99_vsnprintf(char *str, size_t size, const char *format, va_list ap);
-H5_DLL int    Wnanosleep(const struct timespec *req, struct timespec *rem);
 H5_DLL herr_t H5_expand_windows_env_vars(char **env_var);
 H5_DLL wchar_t *H5_get_utf16_str(const char *s);
 H5_DLL int      Wopen_utf8(const char *path, int oflag, ...);
 H5_DLL int      Wremove_utf8(const char *path);
 H5_DLL int      H5_get_win32_times(H5_timevals_t *tvs);
-
-/* Round functions only needed for VS2012 and earlier.
- * They are always built to ensure they don't go stale and
- * can be deleted (along with their #defines, above) when we
- * drop VS2012 support.
- */
-H5_DLL long long Wllround(double arg);
-H5_DLL long long Wllroundf(float arg);
-H5_DLL long      Wlround(double arg);
-H5_DLL long      Wlroundf(float arg);
-H5_DLL double    Wround(double arg);
-H5_DLL float     Wroundf(float arg);
 #ifdef __cplusplus
 }
 #endif /* __cplusplus */
@@ -200,8 +103,6 @@ H5_DLL float     Wroundf(float arg);
 #define HDsetenv(N, V, O)    Wsetenv(N, V, O)
 #define HDflock(F, L)        Wflock(F, L)
 #define HDgetlogin()         Wgetlogin()
-#define HDsnprintf           c99_snprintf  /*varargs*/
-#define HDvsnprintf          c99_vsnprintf /*varargs*/
 
 /* Non-POSIX functions */