Allow usage of page buffering for serial file access from parallel HD…

…F5 builds

release_docs/RELEASE.txt

@@ -790,6 +790,16 @@ Bug Fixes since HDF5-1.14.0 release
 ===================================
     Library
     -------
+    - Fixed library to allow usage of page buffering feature for serial file
+      access with parallel builds of HDF5
+
+      When HDF5 is built with parallel support enabled, the library would previously
+      disallow any usage of page buffering, even if a file was not opened with
+      parallel access. The library now allows usage of page buffering for serial
+      file access with parallel builds of HDF5. Usage of page buffering is still
+      disabled for any form of parallel file access, even if only 1 MPI process
+      is used.
+
     - Fixed a leak of datatype IDs created internally during datatype conversion
 
       Fixed an issue where the library could leak IDs that it creates internally

src/H5Fint.c

@@ -2008,15 +2008,6 @@ H5F_open(const char *name, unsigned flags, hid_t fcpl_id, hid_t fapl_id)
     if (H5P_get(a_plist, H5F_ACS_PAGE_BUFFER_SIZE_NAME, &page_buf_size) < 0)
         HGOTO_ERROR(H5E_FILE, H5E_CANTGET, NULL, "can't get page buffer size");
     if (page_buf_size) {
-#ifdef H5_HAVE_PARALLEL
-        /* Collective metadata writes are not supported with page buffering */
-        if (file->shared->coll_md_write)
-            HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL,
-                        "collective metadata writes are not supported with page buffering");
-
-        /* Temporary: fail file create when page buffering feature is enabled for parallel */
-        HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "page buffering is disabled for parallel");
-#endif /* H5_HAVE_PARALLEL */
         /* Query for other page buffer cache properties */
         if (H5P_get(a_plist, H5F_ACS_PAGE_BUFFER_MIN_META_PERC_NAME, &page_buf_min_meta_perc) < 0)
             HGOTO_ERROR(H5E_FILE, H5E_CANTGET, NULL, "can't get minimum metadata fraction of page buffer");
@@ -2029,14 +2020,30 @@ H5F_open(const char *name, unsigned flags, hid_t fcpl_id, hid_t fapl_id)
         HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't get evict on close value");
 
 #ifdef H5_HAVE_PARALLEL
-    /* Check for evict on close in parallel (currently unsupported) */
+    /* Check for unsupported settings in parallel */
     assert(file->shared);
     if (H5F_SHARED_HAS_FEATURE(file->shared, H5FD_FEAT_HAS_MPI)) {
         int mpi_size = H5F_shared_mpi_get_size(file->shared);
 
-        if ((mpi_size > 1) && evict_on_close)
-            HGOTO_ERROR(H5E_FILE, H5E_UNSUPPORTED, NULL,
-                        "evict on close is currently not supported in parallel HDF5");
+        /*
+         * While there shouldn't be any problems in general with using page buffering
+         * with only 1 MPI process, there are still some testing issues to be fixed.
+         * Until then, page buffering is disabled for any form of parallel access.
+         */
+        if (page_buf_size) {
+            /* Collective metadata writes are not supported with page buffering */
+            if (file->shared->coll_md_write)
+                HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL,
+                            "collective metadata writes are not supported with page buffering");
+
+            HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "page buffering is disabled for parallel");
+        }
+
+        if (mpi_size > 1) {
+            if (evict_on_close)
+                HGOTO_ERROR(H5E_FILE, H5E_UNSUPPORTED, NULL,
+                            "evict on close is currently not supported in parallel HDF5");
+        }
     }
 #endif
 

test/page_buffer.c

@@ -38,9 +38,6 @@
 #define FILENAME_LEN 1024
 
 /* test routines */
-#ifdef H5_HAVE_PARALLEL
-static unsigned verify_page_buffering_disabled(hid_t orig_fapl, const char *driver_name);
-#else
 #define NUM_DSETS 5
 #define NX        100
 #define NY        50
@@ -54,12 +51,9 @@ static unsigned test_stats_collection(hid_t orig_fapl, const char *driver_name);
 /* helper routines */
 static unsigned create_file(char *filename, hid_t fcpl, hid_t fapl);
 static unsigned open_file(char *filename, hid_t fapl, hsize_t page_size, size_t page_buffer_size);
-#endif /* H5_HAVE_PARALLEL */
 
 static const char *FILENAME[] = {"filepaged", NULL};
 
-#ifndef H5_HAVE_PARALLEL
-
 /*-------------------------------------------------------------------------
  * Function:    create_file()
  *
@@ -289,7 +283,6 @@ open_file(char *filename, hid_t fapl, hsize_t page_size, size_t page_buffer_size
     H5E_END_TRY
     return 1;
 }
-#endif /* H5_HAVE_PARALLEL */
 
 /*
  *
@@ -353,8 +346,6 @@ set_multi_split(const char *driver_name, hid_t fapl, hsize_t pagesize)
 
 } /* set_multi_split() */
 
-#ifndef H5_HAVE_PARALLEL
-
 /*-------------------------------------------------------------------------
  * Function:    test_args()
  *
@@ -2043,121 +2034,6 @@ test_stats_collection(hid_t orig_fapl, const char *driver_name)
 
     return 1;
 } /* test_stats_collection */
-#endif /* #ifndef H5_HAVE_PARALLEL */
-
-/*-------------------------------------------------------------------------
- * Function:    verify_page_buffering_disabled()
- *
- * Purpose:     This function should only be called in parallel
- *              builds.
- *
- *              At present, page buffering should be disabled in parallel
- *              builds.  Verify this.
- *
- * Return:      0 if test is successful
- *              1 if test fails
- *
- *-------------------------------------------------------------------------
- */
-
-#ifdef H5_HAVE_PARALLEL
-static unsigned
-verify_page_buffering_disabled(hid_t orig_fapl, const char *driver_name)
-{
-    char  filename[FILENAME_LEN];    /* Filename to use */
-    hid_t file_id = H5I_INVALID_HID; /* File ID */
-    hid_t fcpl    = H5I_INVALID_HID;
-    hid_t fapl    = H5I_INVALID_HID;
-
-    TESTING("Page Buffering Disabled");
-    h5_fixname(FILENAME[0], orig_fapl, filename, sizeof(filename));
-
-    /* first, try to create a file with page buffering enabled */
-
-    if ((fapl = H5Pcopy(orig_fapl)) < 0)
-        TEST_ERROR;
-
-    if (set_multi_split(driver_name, fapl, 4096) != 0)
-        TEST_ERROR;
-
-    if ((fcpl = H5Pcreate(H5P_FILE_CREATE)) < 0)
-        FAIL_STACK_ERROR;
-
-    if (H5Pset_file_space_strategy(fcpl, H5F_FSPACE_STRATEGY_PAGE, 0, (hsize_t)1) < 0)
-        FAIL_STACK_ERROR;
-
-    if (H5Pset_file_space_page_size(fcpl, 4096) < 0)
-        FAIL_STACK_ERROR;
-
-    if (H5Pset_page_buffer_size(fapl, 4096 * 8, 0, 0) < 0)
-        FAIL_STACK_ERROR;
-
-    /* try to create  the file -- should fail */
-    H5E_BEGIN_TRY
-    {
-        file_id = H5Fcreate(filename, H5F_ACC_TRUNC, fcpl, fapl);
-    }
-    H5E_END_TRY
-
-    if (file_id >= 0)
-        TEST_ERROR;
-
-    /* now, create a file, close it, and then try to open it with page
-     * buffering enabled.
-     */
-    if ((fcpl = H5Pcreate(H5P_FILE_CREATE)) < 0)
-        FAIL_STACK_ERROR;
-
-    if (H5Pset_file_space_strategy(fcpl, H5F_FSPACE_STRATEGY_PAGE, 0, (hsize_t)1) < 0)
-        FAIL_STACK_ERROR;
-
-    if (H5Pset_file_space_page_size(fcpl, 4096) < 0)
-        FAIL_STACK_ERROR;
-
-    /* create the file */
-    if ((file_id = H5Fcreate(filename, H5F_ACC_TRUNC, fcpl, H5P_DEFAULT)) < 0)
-        FAIL_STACK_ERROR;
-
-    /* close the file */
-    if (H5Fclose(file_id) < 0)
-        FAIL_STACK_ERROR;
-
-    /* try to open the file using the fapl prepared above which enables
-     * page buffering.  Should fail.
-     */
-    H5E_BEGIN_TRY
-    {
-        file_id = H5Fopen(filename, H5F_ACC_RDWR, fapl);
-    }
-    H5E_END_TRY
-
-    if (file_id >= 0)
-        TEST_ERROR;
-
-    if (H5Pclose(fcpl) < 0)
-        FAIL_STACK_ERROR;
-
-    if (H5Pclose(fapl) < 0)
-        FAIL_STACK_ERROR;
-
-    PASSED();
-
-    return 0;
-
-error:
-
-    H5E_BEGIN_TRY
-    {
-        H5Pclose(fapl);
-        H5Pclose(fcpl);
-        H5Fclose(file_id);
-    }
-    H5E_END_TRY
-
-    return 1;
-
-} /* verify_page_buffering_disabled() */
-#endif /* H5_HAVE_PARALLEL */
 
 /*-------------------------------------------------------------------------
  * Function:    main()
@@ -2203,22 +2079,13 @@ main(void)
         FAIL_STACK_ERROR;
     api_ctx_pushed = true;
 
-#ifdef H5_HAVE_PARALLEL
-
-    puts("Page Buffering is disabled for parallel.");
-    nerrors += verify_page_buffering_disabled(fapl, driver_name);
-
-#else /* H5_HAVE_PARALLEL */
-
     nerrors += test_args(fapl, driver_name);
     nerrors += test_raw_data_handling(fapl, driver_name);
     nerrors += test_lru_processing(fapl, driver_name);
     nerrors += test_min_threshold(fapl, driver_name);
     nerrors += test_stats_collection(fapl, driver_name);
     nerrors += test_pb_fapl_tolerance_at_open();
 
-#endif /* H5_HAVE_PARALLEL */
-
     h5_clean_files(FILENAME, fapl);
 
     if (nerrors)

testpar/t_file.c

@@ -33,13 +33,17 @@
 #define H5MF_FRIEND /*suppress error about including H5MFpkg      */
 #include "H5MFpkg.h"
 
+#ifdef PB_OUT
 #define NUM_DSETS 5
+#endif
 
 int mpi_size, mpi_rank;
 
+#ifdef PB_OUT
 static int create_file(const char *filename, hid_t fcpl, hid_t fapl, int metadata_write_strategy);
 static int open_file(const char *filename, hid_t fapl, int metadata_write_strategy, hsize_t page_size,
                      size_t page_buffer_size);
+#endif
 
 /*
  * test file access by communicator besides COMM_WORLD.
@@ -132,22 +136,29 @@ test_split_comm_access(void)
 void
 test_page_buffer_access(void)
 {
+    const char *filename;
     hid_t       file_id = H5I_INVALID_HID; /* File ID */
     hid_t       fcpl, fapl;
+    herr_t      ret; /* generic return value */
+#ifdef PB_OUT
     size_t      page_count = 0;
     int         i, num_elements = 200;
     haddr_t     raw_addr, meta_addr;
     int        *data;
     H5F_t      *f = NULL;
-    herr_t      ret; /* generic return value */
-    const char *filename;
     bool        api_ctx_pushed = false; /* Whether API context pushed */
+#endif
 
     MPI_Comm_rank(MPI_COMM_WORLD, &mpi_rank);
     MPI_Comm_size(MPI_COMM_WORLD, &mpi_size);
 
     filename = (const char *)GetTestParameters();
 
+    /* Until page buffering is supported in parallel in some form (even if
+     * just for a single MPI process), this test just will just check to
+     * make sure that an error is thrown when page buffering is enabled
+     * with parallel access.
+     */
     if (VERBOSE_MED)
         printf("Page Buffer Usage in Parallel %s\n", filename);
 
@@ -175,6 +186,15 @@ test_page_buffer_access(void)
     ret = H5Pset_coll_metadata_write(fapl, false);
     VRFY((ret >= 0), "");
 
+    /* This should fail due to page buffering not being supported in parallel */
+    H5E_BEGIN_TRY
+    {
+        file_id = H5Fcreate(filename, H5F_ACC_TRUNC, fcpl, fapl);
+    }
+    H5E_END_TRY
+    VRFY((file_id < 0), "H5Fcreate failed");
+
+#ifdef PB_OUT
     ret = create_file(filename, fcpl, fapl, H5AC_METADATA_WRITE_STRATEGY__DISTRIBUTED);
     VRFY((ret == 0), "");
     ret = open_file(filename, fapl, H5AC_METADATA_WRITE_STRATEGY__DISTRIBUTED, sizeof(int) * 100,
@@ -442,8 +462,10 @@ test_page_buffer_access(void)
     free(data);
     data = NULL;
     MPI_Barrier(MPI_COMM_WORLD);
+#endif
 }
 
+#ifdef PB_OUT
 static int
 create_file(const char *filename, hid_t fcpl, hid_t fapl, int metadata_write_strategy)
 {
@@ -760,6 +782,7 @@ open_file(const char *filename, hid_t fapl, int metadata_write_strategy, hsize_t
 
     return nerrors;
 }
+#endif
 
 /*
  * NOTE:  See HDFFV-10894 and add tests later to verify MPI-specific properties in the

testpar/testphdf5.c

@@ -402,9 +402,7 @@ main(int argc, char **argv)
     AddTest("split", test_split_comm_access, NULL, "dataset using split communicators", PARATESTFILE);
     AddTest("h5oflusherror", test_oflush, NULL, "H5Oflush failure", PARATESTFILE);
 
-#ifdef PB_OUT /* temporary: disable page buffering when parallel */
     AddTest("page_buffer", test_page_buffer_access, NULL, "page buffer usage in parallel", PARATESTFILE);
-#endif
 
     AddTest("props", test_file_properties, NULL, "Coll Metadata file property settings", PARATESTFILE);