Merge pull request #1013 in HDFFV/hdf5 from ~DEROBINS/hdf5_der:vol_normalization to develop

* commit 'b8f56d22dfd754715d10accc5997fe923bdb7593':
  Created internal functions for a couple of H5F calls.

3 files changed, 334 insertions, 248 deletions

diff --git a/src/H5F.c b/src/H5F.c
index 2cd65cb..ce5664a 100644
--- a/src/H5F.c
+++ b/src/H5F.c
@@ -1260,82 +1260,23 @@ done:
 herr_t
 H5Fget_metadata_read_retry_info(hid_t file_id, H5F_retry_info_t *info)
 {
-    H5F_t        *file;           /* File object for file ID */
-    unsigned     i, j;            /* Local index variable */
-    size_t       tot_size;        /* Size of each retries[i] */
-    herr_t       ret_value = SUCCEED;       /* Return value */
+    H5F_t          *file;                       /* File object for file ID */
+    herr_t          ret_value = SUCCEED;        /* Return value */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE2("e", "i*x", file_id, info);
 
     /* Check args */
-    if(!info)
+    if (!info)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no info struct")
 
     /* Get the file pointer */
-    if(NULL == (file = (H5F_t *)H5I_object_verify(file_id, H5I_FILE)))
+    if (NULL == (file = (H5F_t *)H5I_object_verify(file_id, H5I_FILE)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "not a file ID")
 
-    /* Copy the # of bins for "retries" array */
-    info->nbins = file->shared->retries_nbins;
-
-    /* Initialize the array of "retries" */
-    HDmemset(info->retries, 0, sizeof(info->retries));
-
-    /* Return if there are no bins -- no retries */
-    if(!info->nbins)
-        HGOTO_DONE(SUCCEED);
-
-    /* Calculate size for each retries[i] */
-    tot_size = info->nbins * sizeof(uint32_t);
-
-    /* Map and copy information to info's retries for metadata items with tracking for read retries */
-    j = 0;
-    for(i = 0; i < H5AC_NTYPES; i++) {
-        switch(i) {
-            case H5AC_OHDR_ID:
-            case H5AC_OHDR_CHK_ID:
-            case H5AC_BT2_HDR_ID:
-            case H5AC_BT2_INT_ID:
-            case H5AC_BT2_LEAF_ID:
-            case H5AC_FHEAP_HDR_ID:
-            case H5AC_FHEAP_DBLOCK_ID:
-            case H5AC_FHEAP_IBLOCK_ID:
-            case H5AC_FSPACE_HDR_ID:
-            case H5AC_FSPACE_SINFO_ID:
-            case H5AC_SOHM_TABLE_ID:
-            case H5AC_SOHM_LIST_ID:
-            case H5AC_EARRAY_HDR_ID:
-            case H5AC_EARRAY_IBLOCK_ID:
-            case H5AC_EARRAY_SBLOCK_ID:
-            case H5AC_EARRAY_DBLOCK_ID:
-            case H5AC_EARRAY_DBLK_PAGE_ID:
-            case H5AC_FARRAY_HDR_ID:
-            case H5AC_FARRAY_DBLOCK_ID:
-            case H5AC_FARRAY_DBLK_PAGE_ID:
-            case H5AC_SUPERBLOCK_ID:
-                HDassert(j < H5F_NUM_METADATA_READ_RETRY_TYPES);
-                if(file->shared->retries[i] != NULL) {
-                    /* Allocate memory for retries[i]
-                     *
-                     * This memory should be released by the user with
-                     * the H5free_memory() call.
-                     */
-                    if(NULL == (info->retries[j] = (uint32_t *)H5MM_malloc(tot_size)))
-                        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed")
-
-                    /* Copy the information */
-                    HDmemcpy(info->retries[j], file->shared->retries[i], tot_size);
-                } /* end if */
-
-                /* Increment location in info->retries[] array */
-                j++;
-                break;
-
-            default:
-                break;
-        } /* end switch */
-    } /* end for */
+    /* Get the retry info */
+    if (H5F_get_metadata_read_retry_info(file, info) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTRELEASE, FAIL, "can't get metadata read retry info")
 
 done:
     FUNC_LEAVE_API(ret_value)
@@ -1446,196 +1387,21 @@ done:
 herr_t
 H5Fstart_swmr_write(hid_t file_id)
 {
-    hbool_t ci_load = FALSE;    /* whether MDC ci load requested */
-    hbool_t ci_write = FALSE;   /* whether MDC CI write requested */
-    H5F_t *file = NULL;         /* File info */
-    size_t grp_dset_count=0;    /* # of open objects: groups & datasets */
-    size_t nt_attr_count=0;     /* # of opened named datatypes  + opened attributes */
-    hid_t *obj_ids=NULL;        /* List of ids */
-    H5G_loc_t *obj_glocs=NULL;  /* Group location of the object */
-    H5O_loc_t *obj_olocs=NULL;  /* Object location */
-    H5G_name_t *obj_paths=NULL; /* Group hierarchy path */
-    size_t u;                   /* Local index variable */
-    hbool_t setup = FALSE;      /* Boolean flag to indicate whether SWMR setting is enabled */
-    H5F_io_info2_t fio_info;    /* I/O info for operation */
-    herr_t ret_value = SUCCEED; /* Return value */
+    H5F_t      *file = NULL;            /* File info */
+    herr_t      ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE1("e", "i", file_id);
 
     /* check args */
-    if(NULL == (file = (H5F_t *)H5I_object_verify(file_id, H5I_FILE)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file")
-
-    /* Should have write permission */
-    if((H5F_INTENT(file) & H5F_ACC_RDWR) == 0)
-        HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "no write intent on file")
-
-    if(file->shared->sblock->super_vers < HDF5_SUPERBLOCK_VERSION_3)
-        HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "file superblock version should be at least 3")
-
-    HDassert((file->shared->low_bound == H5F_LIBVER_V110) && (file->shared->high_bound == H5F_LIBVER_V110));
-
-    /* Should not be marked for SWMR writing mode already */
-    if(file->shared->sblock->status_flags & H5F_SUPER_SWMR_WRITE_ACCESS)
-        HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "file already in SWMR writing mode")
-
-    HDassert(file->shared->sblock->status_flags & H5F_SUPER_WRITE_ACCESS);
-
-    /* Check to see if cache image is enabled.  Fail if so */
-    if(H5C_cache_image_status(file, &ci_load, &ci_write) < 0)
-        HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "can't get MDC cache image status")
-    if(ci_load || ci_write )
-        HGOTO_ERROR(H5E_FILE, H5E_UNSUPPORTED, FAIL, "can't have both SWMR and MDC cache image")
-
-    /* Flush the superblock extension */
-    if(H5F_flush_tagged_metadata(file, file->shared->sblock->ext_addr, H5AC_ind_read_dxpl_id) < 0)
-        HGOTO_ERROR(H5E_FILE, H5E_CANTFLUSH, FAIL, "unable to flush superblock extension")
-
-    /* Flush data buffers */
-    if(H5F__flush(file, H5AC_ind_read_dxpl_id, H5AC_rawdata_dxpl_id, FALSE) < 0)
-        HGOTO_ERROR(H5E_FILE, H5E_CANTFLUSH, FAIL, "unable to flush file's cached information")
-
-    /* Get the # of opened named datatypes and attributes */
-    if(H5F_get_obj_count(file, H5F_OBJ_DATATYPE|H5F_OBJ_ATTR, FALSE, &nt_attr_count) < 0)
-        HGOTO_ERROR(H5E_INTERNAL, H5E_BADITER, FAIL, "H5F_get_obj_count failed")
-    if(nt_attr_count)
-        HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "named datatypes and/or attributes opened in the file")
-
-    /* Get the # of opened datasets and groups */
-    if(H5F_get_obj_count(file, H5F_OBJ_GROUP|H5F_OBJ_DATASET, FALSE, &grp_dset_count) < 0)
-        HGOTO_ERROR(H5E_INTERNAL, H5E_BADITER, FAIL, "H5F_get_obj_count failed")
-
-    if(grp_dset_count) {
-        /* Allocate space for group and object locations */
-    if((obj_ids = (hid_t *) H5MM_malloc(grp_dset_count * sizeof(hid_t))) == NULL)
-        HGOTO_ERROR(H5E_FILE, H5E_NOSPACE, FAIL, "can't allocate buffer for hid_t")
-    if((obj_glocs = (H5G_loc_t *) H5MM_malloc(grp_dset_count * sizeof(H5G_loc_t))) == NULL)
-        HGOTO_ERROR(H5E_FILE, H5E_NOSPACE, FAIL, "can't allocate buffer for H5G_loc_t")
-    if((obj_olocs = (H5O_loc_t *) H5MM_malloc(grp_dset_count * sizeof(H5O_loc_t))) == NULL)
-        HGOTO_ERROR(H5E_FILE, H5E_NOSPACE, FAIL, "can't allocate buffer for H5O_loc_t")
-    if((obj_paths = (H5G_name_t *) H5MM_malloc(grp_dset_count * sizeof(H5G_name_t))) == NULL)
-        HGOTO_ERROR(H5E_FILE, H5E_NOSPACE, FAIL, "can't allocate buffer for H5G_name_t")
-
-        /* Get the list of opened object ids (groups & datasets) */
-    if(H5F_get_obj_ids(file, H5F_OBJ_GROUP|H5F_OBJ_DATASET, grp_dset_count, obj_ids, FALSE, &grp_dset_count) < 0)
-        HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "H5F_get_obj_ids failed")
-
-        /* Refresh opened objects (groups, datasets) in the file */
-        for(u = 0; u < grp_dset_count; u++) {
-            H5O_loc_t *oloc;            /* object location */
-            H5G_loc_t tmp_loc;
-
-            /* Set up the id's group location */
-            obj_glocs[u].oloc = &obj_olocs[u];
-            obj_glocs[u].path = &obj_paths[u];
-            H5G_loc_reset(&obj_glocs[u]);
-
-            /* get the id's object location */
-            if((oloc = H5O_get_loc(obj_ids[u])) == NULL)
-                HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not an object")
-
-            /* Make deep local copy of object's location information */
-            H5G_loc(obj_ids[u], &tmp_loc);
-            H5G_loc_copy(&obj_glocs[u], &tmp_loc, H5_COPY_DEEP);
-
-            /* Close the object */
-            if(H5I_dec_ref(obj_ids[u]) < 0)
-                HGOTO_ERROR(H5E_ATOM, H5E_CANTCLOSEOBJ, FAIL, "decrementing object ID failed")
-        } /* end for */
-    } /* end if */
-
-    /* Set up I/O info for operation */
-    fio_info.f = file;
-    if(NULL == (fio_info.meta_dxpl = (H5P_genplist_t *)H5I_object(H5AC_ind_read_dxpl_id)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
-    if(NULL == (fio_info.raw_dxpl = (H5P_genplist_t *)H5I_object(H5AC_rawdata_dxpl_id)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
-
-    /* Flush and reset the accumulator */
-    if(H5F__accum_reset(&fio_info, TRUE) < 0)
-        HGOTO_ERROR(H5E_IO, H5E_CANTRESET, FAIL, "can't reset accumulator")
-
-    /* Turn on SWMR write in shared file open flags */
-    file->shared->flags |= H5F_ACC_SWMR_WRITE;
-
-    /* Mark the file in SWMR writing mode */
-    file->shared->sblock->status_flags |= H5F_SUPER_SWMR_WRITE_ACCESS;
-
-    /* Set up metadata read attempts */
-    file->shared->read_attempts = H5F_SWMR_METADATA_READ_ATTEMPTS;
-
-    /* Initialize "retries" and "retries_nbins" */
-    if(H5F_set_retries(file) < 0)
-        HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, FAIL, "can't set retries and retries_nbins")
-
-    /* Turn off usage of accumulator */
-    file->shared->feature_flags &= ~(unsigned)H5FD_FEAT_ACCUMULATE_METADATA;
-    if(H5FD_set_feature_flags(file->shared->lf, file->shared->feature_flags) < 0)
-        HGOTO_ERROR(H5E_FILE, H5E_CANTSET, FAIL, "can't set feature_flags in VFD")
-
-    setup = TRUE;
-
-    /* Mark superblock as dirty */
-    if(H5F_super_dirty(file) < 0)
-        HGOTO_ERROR(H5E_FILE, H5E_CANTMARKDIRTY, FAIL, "unable to mark superblock as dirty")
-
-    /* Flush the superblock */
-    if(H5F_flush_tagged_metadata(file, H5AC__SUPERBLOCK_TAG, H5AC_ind_read_dxpl_id) < 0)
-        HGOTO_ERROR(H5E_FILE, H5E_CANTFLUSH, FAIL, "unable to flush superblock")
-
-    /* Evict all flushed entries in the cache except the pinned superblock */
-    if(H5F__evict_cache_entries(file, H5AC_ind_read_dxpl_id) < 0)
-        HGOTO_ERROR(H5E_FILE, H5E_CANTFLUSH, FAIL, "unable to evict file's cached information")
-
-    /* Refresh (reopen) the objects (groups & datasets) in the file */
-    for(u = 0; u < grp_dset_count; u++)
-        if(H5O_refresh_metadata_reopen(obj_ids[u], &obj_glocs[u], H5AC_ind_read_dxpl_id, TRUE) < 0)
-            HGOTO_ERROR(H5E_ATOM, H5E_CLOSEERROR, FAIL, "can't refresh-close object")
+    if (NULL == (file = (H5F_t *)H5I_object_verify(file_id, H5I_FILE)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "hid_t identifier is not a file ID")
 
-    /* Unlock the file */
-    if(H5FD_unlock(file->shared->lf) < 0)
-        HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, FAIL, "unable to unlock the file")
+    /* start SWMR writing */
+    if (H5F_start_swmr_write(file) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_SYSTEM, FAIL, "unable to start SWMR writing")
 
 done:
-    if(ret_value < 0 && setup) {
-        HDassert(file);
-
-        /* Re-enable accumulator */
-        file->shared->feature_flags |= (unsigned)H5FD_FEAT_ACCUMULATE_METADATA;
-        if(H5FD_set_feature_flags(file->shared->lf, file->shared->feature_flags) < 0)
-            HDONE_ERROR(H5E_FILE, H5E_CANTSET, FAIL, "can't set feature_flags in VFD")
-
-        /* Reset the # of read attempts */
-        file->shared->read_attempts = H5F_METADATA_READ_ATTEMPTS;
-        if(H5F_set_retries(file) < 0)
-            HDONE_ERROR(H5E_FILE, H5E_CANTINIT, FAIL, "can't set retries and retries_nbins")
-
-        /* Un-set H5F_ACC_SWMR_WRITE in shared open flags */
-        file->shared->flags &= ~H5F_ACC_SWMR_WRITE;
-
-        /* Unmark the file: not in SWMR writing mode */
-        file->shared->sblock->status_flags &= (uint8_t)(~H5F_SUPER_SWMR_WRITE_ACCESS);
-
-        /* Mark superblock as dirty */
-        if(H5F_super_dirty(file) < 0)
-            HDONE_ERROR(H5E_FILE, H5E_CANTMARKDIRTY, FAIL, "unable to mark superblock as dirty")
-
-        /* Flush the superblock */
-        if(H5F_flush_tagged_metadata(file, H5AC__SUPERBLOCK_TAG, H5AC_ind_read_dxpl_id) < 0)
-            HDONE_ERROR(H5E_FILE, H5E_CANTFLUSH, FAIL, "unable to flush superblock")
-    } /* end if */
-
-    /* Free memory */
-    if(obj_ids)
-        H5MM_xfree(obj_ids);
-    if(obj_glocs)
-        H5MM_xfree(obj_glocs);
-    if(obj_olocs)
-        H5MM_xfree(obj_olocs);
-    if(obj_paths)
-        H5MM_xfree(obj_paths);
-
     FUNC_LEAVE_API(ret_value)
 } /* end H5Fstart_swmr_write() */
 
diff --git a/src/H5Fint.c b/src/H5Fint.c
index 24844a4..1d14ec6 100644
--- a/src/H5Fint.c
+++ b/src/H5Fint.c
@@ -2981,3 +2981,321 @@ H5F_set_coll_md_read(H5F_t *f, H5P_coll_md_read_flag_t cmr)
     FUNC_LEAVE_NOAPI_VOID
 } /* H5F_set_coll_md_read() */
 #endif /* H5_HAVE_PARALLEL */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5F_get_metadata_read_retry_info
+ *
+ * Purpose:     Private function to retrieve the collection of read retries
+ *              for metadata items with checksum.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5F_get_metadata_read_retry_info(H5F_t *file, H5F_retry_info_t *info)
+{
+    unsigned     i, j;            /* Local index variable */
+    size_t       tot_size;        /* Size of each retries[i] */
+    herr_t       ret_value = SUCCEED;       /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Check args */
+    HDassert(file);
+    HDassert(info);
+
+    /* Copy the # of bins for "retries" array */
+    info->nbins = file->shared->retries_nbins;
+
+    /* Initialize the array of "retries" */
+    HDmemset(info->retries, 0, sizeof(info->retries));
+
+    /* Return if there are no bins -- no retries */
+    if (!info->nbins)
+        HGOTO_DONE(SUCCEED);
+
+    /* Calculate size for each retries[i] */
+    tot_size = info->nbins * sizeof(uint32_t);
+
+    /* Map and copy information to info's retries for metadata items with tracking for read retries */
+    j = 0;
+    for (i = 0; i < H5AC_NTYPES; i++) {
+        switch (i) {
+            case H5AC_OHDR_ID:
+            case H5AC_OHDR_CHK_ID:
+            case H5AC_BT2_HDR_ID:
+            case H5AC_BT2_INT_ID:
+            case H5AC_BT2_LEAF_ID:
+            case H5AC_FHEAP_HDR_ID:
+            case H5AC_FHEAP_DBLOCK_ID:
+            case H5AC_FHEAP_IBLOCK_ID:
+            case H5AC_FSPACE_HDR_ID:
+            case H5AC_FSPACE_SINFO_ID:
+            case H5AC_SOHM_TABLE_ID:
+            case H5AC_SOHM_LIST_ID:
+            case H5AC_EARRAY_HDR_ID:
+            case H5AC_EARRAY_IBLOCK_ID:
+            case H5AC_EARRAY_SBLOCK_ID:
+            case H5AC_EARRAY_DBLOCK_ID:
+            case H5AC_EARRAY_DBLK_PAGE_ID:
+            case H5AC_FARRAY_HDR_ID:
+            case H5AC_FARRAY_DBLOCK_ID:
+            case H5AC_FARRAY_DBLK_PAGE_ID:
+            case H5AC_SUPERBLOCK_ID:
+                HDassert(j < H5F_NUM_METADATA_READ_RETRY_TYPES);
+                if (file->shared->retries[i] != NULL) {
+                    /* Allocate memory for retries[i]
+                     *
+                     * This memory should be released by the user with
+                     * the H5free_memory() call.
+                     */
+                    if (NULL == (info->retries[j] = (uint32_t *)H5MM_malloc(tot_size)))
+                        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed")
+
+                    /* Copy the information */
+                    HDmemcpy(info->retries[j], file->shared->retries[i], tot_size);
+                }
+
+                /* Increment location in info->retries[] array */
+                j++;
+                break;
+
+            default:
+                break;
+        }
+    }
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5F_get_metadata_read_retry_info() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5F_start_swmr_write
+ *
+ * Purpose:     To enable SWMR writing mode for the file
+ *
+ *              1) Refresh opened objects: part 1
+ *              2) Flush & reset accumulator
+ *              3) Mark the file in SWMR writing mode
+ *              4) Set metadata read attempts and retries info
+ *              5) Disable accumulator
+ *              6) Evict all cache entries except the superblock
+ *              7) Refresh opened objects (part 2)
+ *              8) Unlock the file
+ *
+ *              Pre-conditions:
+ *
+ *              1) The file being opened has v3 superblock
+ *              2) The file is opened with H5F_ACC_RDWR
+ *              3) The file is not already marked for SWMR writing
+ *              4) Current implementaion for opened objects:
+ *                  --only allow datasets and groups without attributes
+ *                  --disallow named datatype with/without attributes
+ *                  --disallow opened attributes attached to objects
+ *
+ * NOTE:        Currently, only opened groups and datasets are allowed
+ *              when enabling SWMR via H5Fstart_swmr_write().
+ *              Will later implement a different approach--
+ *              set up flush dependency/proxy even for file opened without
+ *              SWMR to resolve issues with opened objects.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5F_start_swmr_write(H5F_t *file)
+{
+    hbool_t ci_load = FALSE;        /* whether MDC ci load requested */
+    hbool_t ci_write = FALSE;       /* whether MDC CI write requested */
+    size_t grp_dset_count=0;        /* # of open objects: groups & datasets */
+    size_t nt_attr_count=0;         /* # of opened named datatypes  + opened attributes */
+    hid_t *obj_ids = NULL;          /* List of ids */
+    H5G_loc_t *obj_glocs = NULL;    /* Group location of the object */
+    H5O_loc_t *obj_olocs = NULL;    /* Object location */
+    H5G_name_t *obj_paths = NULL;   /* Group hierarchy path */
+    size_t u;                       /* Local index variable */
+    hbool_t setup = FALSE;          /* Boolean flag to indicate whether SWMR setting is enabled */
+    H5F_io_info2_t fio_info;        /* I/O info for operation */
+    herr_t ret_value = SUCCEED;     /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* check args */
+    HDassert(file);
+
+    /* Should have write permission */
+    if ((H5F_INTENT(file) & H5F_ACC_RDWR) == 0)
+        HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "no write intent on file")
+
+    /* Check superblock version */
+    if (file->shared->sblock->super_vers < HDF5_SUPERBLOCK_VERSION_3)
+        HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "file superblock version - should be at least 3")
+
+    /* Check for correct file format version */
+    if ((file->shared->low_bound != H5F_LIBVER_V110) || (file->shared->high_bound != H5F_LIBVER_V110))
+        HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "file format version does not support SWMR - needs to be 1.10 or greater")
+
+    /* Should not be marked for SWMR writing mode already */
+    if (file->shared->sblock->status_flags & H5F_SUPER_SWMR_WRITE_ACCESS)
+        HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "file already in SWMR writing mode")
+
+    /* Check to see if cache image is enabled.  Fail if so */
+    if (H5C_cache_image_status(file, &ci_load, &ci_write) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "can't get MDC cache image status")
+    if (ci_load || ci_write )
+        HGOTO_ERROR(H5E_FILE, H5E_UNSUPPORTED, FAIL, "can't have both SWMR and MDC cache image")
+
+    /* Flush the superblock extension */
+    if (H5F_flush_tagged_metadata(file, file->shared->sblock->ext_addr, H5AC_ind_read_dxpl_id) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTFLUSH, FAIL, "unable to flush superblock extension")
+
+    /* Flush data buffers */
+    if (H5F__flush(file, H5AC_ind_read_dxpl_id, H5AC_rawdata_dxpl_id, FALSE) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTFLUSH, FAIL, "unable to flush file's cached information")
+
+    /* Get the # of opened named datatypes and attributes */
+    if (H5F_get_obj_count(file, H5F_OBJ_DATATYPE|H5F_OBJ_ATTR, FALSE, &nt_attr_count) < 0)
+        HGOTO_ERROR(H5E_INTERNAL, H5E_BADITER, FAIL, "H5F_get_obj_count failed")
+    if (nt_attr_count)
+        HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "named datatypes and/or attributes opened in the file")
+
+    /* Get the # of opened datasets and groups */
+    if (H5F_get_obj_count(file, H5F_OBJ_GROUP|H5F_OBJ_DATASET, FALSE, &grp_dset_count) < 0)
+        HGOTO_ERROR(H5E_INTERNAL, H5E_BADITER, FAIL, "H5F_get_obj_count failed")
+
+    if (grp_dset_count) {
+        /* Allocate space for group and object locations */
+        if ((obj_ids = (hid_t *) H5MM_malloc(grp_dset_count * sizeof(hid_t))) == NULL)
+            HGOTO_ERROR(H5E_FILE, H5E_NOSPACE, FAIL, "can't allocate buffer for hid_t")
+        if ((obj_glocs = (H5G_loc_t *) H5MM_malloc(grp_dset_count * sizeof(H5G_loc_t))) == NULL)
+            HGOTO_ERROR(H5E_FILE, H5E_NOSPACE, FAIL, "can't allocate buffer for H5G_loc_t")
+        if ((obj_olocs = (H5O_loc_t *) H5MM_malloc(grp_dset_count * sizeof(H5O_loc_t))) == NULL)
+            HGOTO_ERROR(H5E_FILE, H5E_NOSPACE, FAIL, "can't allocate buffer for H5O_loc_t")
+        if ((obj_paths = (H5G_name_t *) H5MM_malloc(grp_dset_count * sizeof(H5G_name_t))) == NULL)
+            HGOTO_ERROR(H5E_FILE, H5E_NOSPACE, FAIL, "can't allocate buffer for H5G_name_t")
+
+        /* Get the list of opened object ids (groups & datasets) */
+        if (H5F_get_obj_ids(file, H5F_OBJ_GROUP|H5F_OBJ_DATASET, grp_dset_count, obj_ids, FALSE, &grp_dset_count) < 0)
+            HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "H5F_get_obj_ids failed")
+
+        /* Refresh opened objects (groups, datasets) in the file */
+        for (u = 0; u < grp_dset_count; u++) {
+            H5O_loc_t *oloc;            /* object location */
+            H5G_loc_t tmp_loc;
+
+            /* Set up the id's group location */
+            obj_glocs[u].oloc = &obj_olocs[u];
+            obj_glocs[u].path = &obj_paths[u];
+            H5G_loc_reset(&obj_glocs[u]);
+
+            /* get the id's object location */
+            if ((oloc = H5O_get_loc(obj_ids[u])) == NULL)
+                HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not an object")
+
+            /* Make deep local copy of object's location information */
+            H5G_loc(obj_ids[u], &tmp_loc);
+            H5G_loc_copy(&obj_glocs[u], &tmp_loc, H5_COPY_DEEP);
+
+            /* Close the object */
+            if (H5I_dec_ref(obj_ids[u]) < 0)
+                HGOTO_ERROR(H5E_ATOM, H5E_CANTCLOSEOBJ, FAIL, "decrementing object ID failed")
+        }
+    }
+
+    /* Set up I/O info for operation */
+    fio_info.f = file;
+    if (NULL == (fio_info.meta_dxpl = (H5P_genplist_t *)H5I_object(H5AC_ind_read_dxpl_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
+    if (NULL == (fio_info.raw_dxpl = (H5P_genplist_t *)H5I_object(H5AC_rawdata_dxpl_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
+
+    /* Flush and reset the accumulator */
+    if (H5F__accum_reset(&fio_info, TRUE) < 0)
+        HGOTO_ERROR(H5E_IO, H5E_CANTRESET, FAIL, "can't reset accumulator")
+
+    /* Turn on SWMR write in shared file open flags */
+    file->shared->flags |= H5F_ACC_SWMR_WRITE;
+
+    /* Mark the file in SWMR writing mode */
+    file->shared->sblock->status_flags |= H5F_SUPER_SWMR_WRITE_ACCESS;
+
+    /* Set up metadata read attempts */
+    file->shared->read_attempts = H5F_SWMR_METADATA_READ_ATTEMPTS;
+
+    /* Initialize "retries" and "retries_nbins" */
+    if (H5F_set_retries(file) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, FAIL, "can't set retries and retries_nbins")
+
+    /* Turn off usage of accumulator */
+    file->shared->feature_flags &= ~(unsigned)H5FD_FEAT_ACCUMULATE_METADATA;
+    if (H5FD_set_feature_flags(file->shared->lf, file->shared->feature_flags) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTSET, FAIL, "can't set feature_flags in VFD")
+
+    setup = TRUE;
+
+    /* Mark superblock as dirty */
+    if (H5F_super_dirty(file) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTMARKDIRTY, FAIL, "unable to mark superblock as dirty")
+
+    /* Flush the superblock */
+    if (H5F_flush_tagged_metadata(file, H5AC__SUPERBLOCK_TAG, H5AC_ind_read_dxpl_id) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTFLUSH, FAIL, "unable to flush superblock")
+
+    /* Evict all flushed entries in the cache except the pinned superblock */
+    if (H5F__evict_cache_entries(file, H5AC_ind_read_dxpl_id) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTFLUSH, FAIL, "unable to evict file's cached information")
+
+    /* Refresh (reopen) the objects (groups & datasets) in the file */
+    for (u = 0; u < grp_dset_count; u++)
+        if (H5O_refresh_metadata_reopen(obj_ids[u], &obj_glocs[u], H5AC_ind_read_dxpl_id, TRUE) < 0)
+            HGOTO_ERROR(H5E_ATOM, H5E_CLOSEERROR, FAIL, "can't refresh-close object")
+
+    /* Unlock the file */
+    if (H5FD_unlock(file->shared->lf) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, FAIL, "unable to unlock the file")
+
+done:
+    if(ret_value < 0 && setup) {
+
+        /* Re-enable accumulator */
+        file->shared->feature_flags |= (unsigned)H5FD_FEAT_ACCUMULATE_METADATA;
+        if (H5FD_set_feature_flags(file->shared->lf, file->shared->feature_flags) < 0)
+            HDONE_ERROR(H5E_FILE, H5E_CANTSET, FAIL, "can't set feature_flags in VFD")
+
+        /* Reset the # of read attempts */
+        file->shared->read_attempts = H5F_METADATA_READ_ATTEMPTS;
+        if (H5F_set_retries(file) < 0)
+            HDONE_ERROR(H5E_FILE, H5E_CANTINIT, FAIL, "can't set retries and retries_nbins")
+
+        /* Un-set H5F_ACC_SWMR_WRITE in shared open flags */
+        file->shared->flags &= ~H5F_ACC_SWMR_WRITE;
+
+        /* Unmark the file: not in SWMR writing mode */
+        file->shared->sblock->status_flags &= (uint8_t)(~H5F_SUPER_SWMR_WRITE_ACCESS);
+
+        /* Mark superblock as dirty */
+        if (H5F_super_dirty(file) < 0)
+            HDONE_ERROR(H5E_FILE, H5E_CANTMARKDIRTY, FAIL, "unable to mark superblock as dirty")
+
+        /* Flush the superblock */
+        if (H5F_flush_tagged_metadata(file, H5AC__SUPERBLOCK_TAG, H5AC_ind_read_dxpl_id) < 0)
+            HDONE_ERROR(H5E_FILE, H5E_CANTFLUSH, FAIL, "unable to flush superblock")
+    }
+
+    /* Free memory */
+    if (obj_ids)
+        H5MM_xfree(obj_ids);
+    if (obj_glocs)
+        H5MM_xfree(obj_glocs);
+    if (obj_olocs)
+        H5MM_xfree(obj_olocs);
+    if (obj_paths)
+        H5MM_xfree(obj_paths);
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5F_start_swmr_write() */
+
diff --git a/src/H5Fprivate.h b/src/H5Fprivate.h
index 28ebbd2..a53ca24 100644
--- a/src/H5Fprivate.h
+++ b/src/H5Fprivate.h
@@ -723,6 +723,7 @@ typedef enum H5F_mem_page_t {
 H5_DLL H5F_t *H5F_open(const char *name, unsigned flags, hid_t fcpl_id,
     hid_t fapl_id, hid_t dxpl_id);
 H5_DLL herr_t H5F_try_close(H5F_t *f, hbool_t *was_closed/*out*/);
+H5_DLL herr_t H5F_start_swmr_write(H5F_t *file);
 
 /* Functions that retrieve values from the file struct */
 H5_DLL H5F_libver_t H5F_get_low_bound(const H5F_t *f);
@@ -817,6 +818,7 @@ H5_DLL herr_t H5F_get_checksums(const uint8_t *buf, size_t chk_size, uint32_t *s
 /* Routine to track the # of retries */
 H5_DLL herr_t H5F_track_metadata_read_retries(H5F_t *f, unsigned actype, unsigned retries);
 H5_DLL herr_t H5F_set_retries(H5F_t *f);
+H5_DLL herr_t H5F_get_metadata_read_retry_info(H5F_t *file, H5F_retry_info_t *info);
 
 /* Routine to invoke callback function upon object flush */
 H5_DLL herr_t H5F_object_flush_cb(H5F_t *f, hid_t obj_id);