[svn-r29850] Description:

    Bring H5DOappend(), H5P[s|g]et_object_flush_cb, and H5P[s|g]et_append_flush
from revise_chunks branch to trunk.  Brings along updated metadata cache
entry tagging, and the internal object flush routine.

Tested on:
    MacOSX/64 10.11.4 (amazon) w/serial, parallel & production
    (h5committest forthcoming)

22 files changed, 946 insertions, 173 deletions

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 4e425b1..c9fb8c7 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -433,6 +433,7 @@ set (H5O_SRCS
     ${HDF5_SRC_DIR}/H5Odtype.c
     ${HDF5_SRC_DIR}/H5Oefl.c
     ${HDF5_SRC_DIR}/H5Ofill.c
+    ${HDF5_SRC_DIR}/H5Oflush.c
     ${HDF5_SRC_DIR}/H5Ofsinfo.c
     ${HDF5_SRC_DIR}/H5Oginfo.c
     ${HDF5_SRC_DIR}/H5Olayout.c
diff --git a/src/H5AC.c b/src/H5AC.c
index 6a71f29..c0c6604 100644
--- a/src/H5AC.c
+++ b/src/H5AC.c
@@ -67,6 +67,9 @@ static herr_t H5AC__check_if_write_permitted(const H5F_t *f,
     hbool_t *write_permitted_ptr);
 static herr_t H5AC__ext_config_2_int_config(H5AC_cache_config_t *ext_conf_ptr,
     H5C_auto_size_ctl_t *int_conf_ptr);
+#if H5AC_DO_TAGGING_SANITY_CHECKS
+static herr_t H5AC__verify_tag(hid_t dxpl_id, const H5AC_class_t * type);
+#endif /* H5AC_DO_TAGGING_SANITY_CHECKS */
 
 
 /*********************/
@@ -824,6 +827,11 @@ H5AC_insert_entry(H5F_t *f, hid_t dxpl_id, const H5AC_class_t *type, haddr_t add
             flags);
 #endif /* H5AC__TRACE_FILE_ENABLED */
 
+#if H5AC_DO_TAGGING_SANITY_CHECKS
+    if(!H5C_get_ignore_tags(f->shared->cache) && (H5AC__verify_tag(dxpl_id, type) < 0))
+        HGOTO_ERROR(H5E_CACHE, H5E_CANTTAG, FAIL, "Bad tag value")
+#endif /* H5AC_DO_TAGGING_SANITY_CHECKS */
+
     /* Insert entry into metadata cache */
     if(H5C_insert_entry(f, dxpl_id, type, addr, thing, flags) < 0)
         HGOTO_ERROR(H5E_CACHE, H5E_CANTINS, FAIL, "H5C_insert_entry() failed")
@@ -1135,8 +1143,8 @@ H5AC_protect(H5F_t *f, hid_t dxpl_id, const H5AC_class_t *type, haddr_t addr,
     size_t		trace_entry_size = 0;
     FILE *              trace_file_ptr = NULL;
 #endif /* H5AC__TRACE_FILE_ENABLED */
-    void *		thing = NULL;           /* Pointer to native data structure for entry */
-    void *		ret_value = NULL;       /* Return value */
+    void *              thing = NULL;           /* Pointer to native data structure for entry */
+    void *              ret_value;              /* Return value */
 
     FUNC_ENTER_NOAPI(NULL)
 
@@ -1174,6 +1182,11 @@ H5AC_protect(H5F_t *f, hid_t dxpl_id, const H5AC_class_t *type, haddr_t addr,
 		(int)(type->id), flags);
 #endif /* H5AC__TRACE_FILE_ENABLED */
 
+#if H5AC_DO_TAGGING_SANITY_CHECKS
+    if(!H5C_get_ignore_tags(f->shared->cache) && (H5AC__verify_tag(dxpl_id, type) < 0))
+        HGOTO_ERROR(H5E_CACHE, H5E_CANTTAG, NULL, "Bad tag value")
+#endif /* H5AC_DO_TAGGING_SANITY_CHECKS */
+
     if(NULL == (thing = H5C_protect(f, dxpl_id, type, addr, udata, flags)))
         HGOTO_ERROR(H5E_CACHE, H5E_CANTPROTECT, NULL, "H5C_protect() failed.")
 
@@ -1776,7 +1789,7 @@ H5AC_set_cache_auto_resize_config(H5AC_t *cache_ptr, H5AC_cache_config_t *config
 
     /* Validate external configuration */
     if(H5AC_validate_config(config_ptr) != SUCCEED)
-        HGOTO_ERROR(H5E_CACHE, H5E_BADVALUE, FAIL, "Bad cache configuration");
+        HGOTO_ERROR(H5E_CACHE, H5E_BADVALUE, FAIL, "Bad cache configuration")
 
     if(config_ptr->open_trace_file) {
 	FILE * file_ptr;
@@ -2342,6 +2355,7 @@ done:
 herr_t
 H5AC_tag(hid_t dxpl_id, haddr_t metadata_tag, haddr_t *prev_tag)
 {
+    H5C_tag_t tag;                  /* Tag structure */
     H5P_genplist_t *dxpl;           /* Dataset transfer property list */
     herr_t ret_value = SUCCEED;     /* Return value */
 
@@ -2352,12 +2366,32 @@ H5AC_tag(hid_t dxpl_id, haddr_t metadata_tag, haddr_t *prev_tag)
         HGOTO_ERROR(H5E_CACHE, H5E_BADTYPE, FAIL, "not a property list")
 
     /* Get the current tag value and return that (if prev_tag is NOT null) */
-    if(prev_tag)
-        if((H5P_get(dxpl, "H5AC_metadata_tag", prev_tag)) < 0)
-            HGOTO_ERROR(H5E_CACHE, H5E_CANTGET, FAIL, "unable to query dxpl")
+    if(prev_tag) {
+        if((H5P_get(dxpl, "H5C_tag", &tag)) < 0)
+            HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "unable to query dxpl")
+        *prev_tag = tag.value;
+    } /* end if */
 
-    /* Set the provided tag value in the dxpl_id. */
-    if(H5P_set(dxpl, "H5AC_metadata_tag", &metadata_tag) < 0)
+    /* Add metadata_tag to tag structure */
+    tag.value = metadata_tag;
+
+    /* Determine globality of tag */
+    switch(metadata_tag) {
+        case H5AC__SUPERBLOCK_TAG:
+        case H5AC__SOHM_TAG:
+        case H5AC__GLOBALHEAP_TAG:
+            tag.globality = H5C_GLOBALITY_MAJOR;
+            break;
+        case H5AC__FREESPACE_TAG:
+            tag.globality = H5C_GLOBALITY_MINOR;
+            break;
+        default:
+            tag.globality = H5C_GLOBALITY_NONE;
+            break;
+    } /* end switch */
+
+    /* Set the provided tag in the dxpl_id. */
+    if(H5P_set(dxpl, "H5C_tag", &tag) < 0)
         HGOTO_ERROR(H5E_CACHE, H5E_CANTSET, FAIL, "can't set property in dxpl")
 
 done:
@@ -2388,13 +2422,91 @@ H5AC_retag_copied_metadata(const H5F_t *f, haddr_t metadata_tag)
     HDassert(f);
     HDassert(f->shared);
      
-    /* Call cache-level function to retag entries */
-    H5C_retag_copied_metadata(f->shared->cache, metadata_tag);
+    /* Call cache-level function to re-tag entries with the COPIED tag */
+    H5C_retag_entries(f->shared->cache, H5AC__COPIED_TAG, metadata_tag);
 
     FUNC_LEAVE_NOAPI(SUCCEED)
 } /* H5AC_retag_copied_metadata */
 
 
+/*------------------------------------------------------------------------------
+ * Function:    H5AC_flush_tagged_metadata()
+ *
+ * Purpose:     Wrapper for cache level function which flushes all metadata
+ *              that contains the specific tag. 
+ * 
+ * Return:      SUCCEED on success, FAIL otherwise.
+ *
+ * Programmer:  Mike McGreevy
+ *              May 19, 2010
+ *
+ *------------------------------------------------------------------------------
+ */
+herr_t
+H5AC_flush_tagged_metadata(H5F_t * f, haddr_t metadata_tag, hid_t dxpl_id)
+{
+    /* Variable Declarations */
+    herr_t ret_value = SUCCEED;
+ 
+    /* Function Enter Macro */   
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Assertions */
+    HDassert(f);
+    HDassert(f->shared);
+
+    /* Call cache level function to flush metadata entries with specified tag */
+    if(H5C_flush_tagged_entries(f, dxpl_id, metadata_tag) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "Cannot flush metadata")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5AC_flush_tagged_metadata */
+
+
+#if H5AC_DO_TAGGING_SANITY_CHECKS
+
+/*-------------------------------------------------------------------------
+ *
+ * Function:    H5AC__verify_tag
+ *
+ * Purpose:     Performs sanity checking on an entry type and tag value
+ *              stored in a supplied dxpl_id.
+ *
+ * Return:      SUCCEED or FAIL.
+ *
+ * Programmer:  Mike McGreevy
+ *              October 20, 2010
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5AC__verify_tag(hid_t dxpl_id, const H5AC_class_t *type)
+{
+    H5P_genplist_t *dxpl;               /* DXPL for operation */
+    H5C_tag_t tag;                      /* Entry tag to validate */
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_STATIC
+
+    /* Get the dataset transfer property list */
+    if(NULL == (dxpl = (H5P_genplist_t *)H5I_object_verify(dxpl_id, H5I_GENPROP_LST)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a property list")
+
+    /* Get the tag from the DXPL */
+    if((H5P_get(dxpl, "H5C_tag", &tag)) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "unable to query property value")
+
+    /* Verify legal tag value */
+    if(H5C_verify_tag(type->id, tag.value, tag.globality) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_CANTGET, FAIL, "tag verification failed")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5AC__verify_tag */
+#endif /* H5AC_DO_TAGGING_SANITY_CHECKS */
+
+
 /*-------------------------------------------------------------------------
  * Function:    H5AC_get_entry_ring
  *
diff --git a/src/H5ACprivate.h b/src/H5ACprivate.h
index 711d441..5b871ff 100644
--- a/src/H5ACprivate.h
+++ b/src/H5ACprivate.h
@@ -121,6 +121,12 @@ typedef enum {
 #define H5AC__DEFAULT_MAX_CACHE_SIZE	H5C__DEFAULT_MAX_CACHE_SIZE
 #define H5AC__DEFAULT_MIN_CLEAN_SIZE	H5C__DEFAULT_MIN_CLEAN_SIZE
 
+/* Check if we are sanity checking tagging */
+#if H5C_DO_TAGGING_SANITY_CHECKS
+#define H5AC_DO_TAGGING_SANITY_CHECKS 1
+#else
+#define H5AC_DO_TAGGING_SANITY_CHECKS 0
+#endif
 
 /*
  * Class methods pertaining to caching.	 Each type of cached object will
@@ -181,10 +187,6 @@ typedef H5C_cache_entry_t		H5AC_info_t;
 /* Typedef for metadata cache (defined in H5Cpkg.h) */
 typedef H5C_t	H5AC_t;
 
-#define H5AC_METADATA_TAG_NAME           "H5AC_metadata_tag"
-#define H5AC_METADATA_TAG_SIZE           sizeof(haddr_t)
-#define H5AC_METADATA_TAG_DEF            H5AC__INVALID_TAG
-
 #define H5AC_RING_NAME  "H5AC_ring_type"
 
 /* Dataset transfer property lists for metadata calls */
@@ -356,6 +358,7 @@ H5_DLL herr_t H5AC_open_trace_file(H5AC_t *cache_ptr, const char *trace_file_nam
 
 /* Tag & Ring routines */
 H5_DLL herr_t H5AC_tag(hid_t dxpl_id, haddr_t metadata_tag, haddr_t *prev_tag);
+H5_DLL herr_t H5AC_flush_tagged_metadata(H5F_t * f, haddr_t metadata_tag, hid_t dxpl_id);
 H5_DLL herr_t H5AC_retag_copied_metadata(const H5F_t *f, haddr_t metadata_tag);
 H5_DLL herr_t H5AC_ignore_tags(const H5F_t *f);
 H5_DLL herr_t H5AC_get_entry_ring(const H5F_t *f, haddr_t addr, H5AC_ring_t *ring);
diff --git a/src/H5C.c b/src/H5C.c
index 8df9679..0082a98 100644
--- a/src/H5C.c
+++ b/src/H5C.c
@@ -166,28 +166,18 @@ static herr_t H5C_make_space_in_cache(H5F_t * f,
        	                              size_t  space_needed,
                                       hbool_t write_permitted);
 
-static herr_t H5C_tag_entry(H5C_t * cache_ptr, 
+static herr_t H5C__tag_entry(H5C_t * cache_ptr, 
                             H5C_cache_entry_t * entry_ptr,
                             hid_t dxpl_id);
 
-static herr_t H5C_flush_tagged_entries(H5F_t * f, 
-                                       hid_t dxpl_id, 
-                                       H5C_t * cache_ptr, 
-                                       haddr_t tag);
+static herr_t H5C__mark_tagged_entries(H5C_t * cache_ptr, haddr_t tag);
 
-static herr_t H5C_mark_tagged_entries(H5C_t * cache_ptr, 
-                                      haddr_t tag);
-
-static herr_t H5C_flush_marked_entries(H5F_t * f, 
+static herr_t H5C__flush_marked_entries(H5F_t * f, 
                                        hid_t dxpl_id);
 
 static herr_t H5C__generate_image(const H5F_t *f, H5C_t * cache_ptr, H5C_cache_entry_t *entry_ptr, 
                                   hid_t dxpl_id, int64_t *entry_size_change_ptr);
 
-#if H5C_DO_TAGGING_SANITY_CHECKS
-static herr_t H5C_verify_tag(int id, haddr_t tag);
-#endif
-
 #if H5C_DO_SLIST_SANITY_CHECKS
 static hbool_t H5C_entry_in_skip_list(H5C_t * cache_ptr, 
                                       H5C_cache_entry_t *target_ptr);
@@ -1848,7 +1838,7 @@ H5C_insert_entry(H5F_t *             f,
     entry_ptr->image_up_to_date = FALSE;
 
     /* Apply tag to newly inserted entry */
-    if(H5C_tag_entry(cache_ptr, entry_ptr, dxpl_id) < 0)
+    if(H5C__tag_entry(cache_ptr, entry_ptr, dxpl_id) < 0)
         HGOTO_ERROR(H5E_CACHE, H5E_CANTTAG, FAIL, "Cannot tag metadata entry")
 
     entry_ptr->is_protected = FALSE;
@@ -2777,7 +2767,7 @@ H5C_protect(H5F_t *		f,
 
 #if H5C_DO_TAGGING_SANITY_CHECKS
 {
-        haddr_t     tag = HADDR_UNDEF;
+        H5C_tag_t tag;              /* Tag structure */
 
         /* The entry is already in the cache, but make sure that the tag value 
            being passed in via dxpl is still legal. This will ensure that had
@@ -2786,14 +2776,14 @@ H5C_protect(H5F_t *		f,
            from disk. */
 
         /* Get the tag from the DXPL */
-        if((H5P_get(dxpl, "H5AC_metadata_tag", &tag)) < 0)
+        if((H5P_get(dxpl, "H5C_tag", &tag)) < 0)
             HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "unable to query property value");
     
         /* Verify tag value */
         if(cache_ptr->ignore_tags != TRUE) {
             /* Verify legal tag value */
-            if((H5C_verify_tag(entry_ptr->type->id, tag)) < 0)
-                HGOTO_ERROR(H5E_CACHE, H5E_CANTGET, NULL, "tag verification failed");
+            if(H5C_verify_tag(entry_ptr->type->id, tag.value, tag.globality) < 0)
+                HGOTO_ERROR(H5E_CACHE, H5E_CANTGET, NULL, "tag verification failed")
         } /* end if */
 }
 #endif
@@ -2822,7 +2812,7 @@ H5C_protect(H5F_t *		f,
 #endif /* H5_HAVE_PARALLEL */
 
         /* Apply tag to newly protected entry */
-        if(H5C_tag_entry(cache_ptr, entry_ptr, dxpl_id) < 0)
+        if(H5C__tag_entry(cache_ptr, entry_ptr, dxpl_id) < 0)
             HGOTO_ERROR(H5E_CACHE, H5E_CANTTAG, NULL, "Cannot tag metadata entry")
 
         /* If the entry is very large, and we are configured to allow it,
@@ -7462,7 +7452,8 @@ H5C_flush_ring(H5F_t *f, hid_t dxpl_id, H5C_ring_t ring,  unsigned flags)
                 HDassert(entry_ptr->magic == H5C__H5C_CACHE_ENTRY_T_MAGIC);
                 HDassert(entry_ptr->in_slist);
                 HDassert(entry_ptr->is_dirty);
-                HDassert(entry_ptr->ring >= ring);
+                if(!flush_marked_entries || entry_ptr->flush_marker)
+                    HDassert(entry_ptr->ring >= ring);
 
                 /* increment node pointer now, before we delete its target
                  * from the slist.
@@ -7476,7 +7467,8 @@ H5C_flush_ring(H5F_t *f, hid_t dxpl_id, H5C_ring_t ring,  unsigned flags)
                     HDassert(next_entry_ptr->magic == H5C__H5C_CACHE_ENTRY_T_MAGIC);
                     HDassert(next_entry_ptr->is_dirty);
                     HDassert(next_entry_ptr->in_slist);
-                    HDassert(next_entry_ptr->ring >= ring);
+                    if(!flush_marked_entries || next_entry_ptr->flush_marker)
+                        HDassert(next_entry_ptr->ring >= ring);
                     HDassert(entry_ptr != next_entry_ptr);
                 } /* end if */
                 else
@@ -8481,8 +8473,8 @@ H5C_load_entry(H5F_t *              f,
     entry->addr                 = addr;
     entry->size                 = len;
     HDassert(entry->size < H5C_MAX_ENTRY_SIZE);
-    entry->compressed		= compressed;
-    entry->compressed_size	= compressed_size;
+    entry->compressed           = compressed;
+    entry->compressed_size      = compressed_size;
     entry->image_ptr            = image;
     entry->image_up_to_date     = TRUE;
     entry->type                 = type;
@@ -9565,7 +9557,34 @@ H5C_ignore_tags(H5C_t * cache_ptr)
 
 /*-------------------------------------------------------------------------
  *
- * Function:    H5C_tag_entry
+ * Function:    H5C_get_ignore_tags
+ *
+ * Purpose:     Retrieve the 'ignore_tags' field for the cache
+ *
+ * Return:      'ignore_tags' value (can't fail)
+ *
+ * Programmer:  Quincey Koziol
+ *              April 30, 2016
+ *
+ *-------------------------------------------------------------------------
+ */
+hbool_t
+H5C_get_ignore_tags(const H5C_t *cache_ptr)
+{
+    FUNC_ENTER_NOAPI_NOERR
+
+    /* Sanity checks */
+    HDassert(cache_ptr);
+    HDassert(cache_ptr->magic == H5C__H5C_T_MAGIC);
+
+    /* Return ignore tag value */
+    FUNC_LEAVE_NOAPI(cache_ptr->ignore_tags)
+} /* H5C_get_ignore_tags */
+
+
+/*-------------------------------------------------------------------------
+ *
+ * Function:    H5C__tag_entry
  *
  * Purpose:     Tags an entry with the provided tag (contained in the dxpl_id).
  *              If sanity checking is enabled, this function will perform 
@@ -9582,13 +9601,13 @@ H5C_ignore_tags(H5C_t * cache_ptr)
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5C_tag_entry(H5C_t * cache_ptr, H5C_cache_entry_t * entry_ptr, hid_t dxpl_id)
+H5C__tag_entry(H5C_t * cache_ptr, H5C_cache_entry_t * entry_ptr, hid_t dxpl_id)
 {
     H5P_genplist_t *dxpl;       /* dataset transfer property list */
-    haddr_t tag;                /* Tag address */
+    H5C_tag_t tag;              /* Tag structure */
     herr_t ret_value = SUCCEED;  /* Return value */
 
-    FUNC_ENTER_NOAPI(FAIL)
+    FUNC_ENTER_STATIC
 
     /* Assertions */
     HDassert(cache_ptr != NULL);
@@ -9600,13 +9619,13 @@ H5C_tag_entry(H5C_t * cache_ptr, H5C_cache_entry_t * entry_ptr, hid_t dxpl_id)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a property list")
 
     /* Get the tag from the DXPL */
-    if((H5P_get(dxpl, "H5AC_metadata_tag", &tag)) < 0)
-        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "unable to query property value")
+    if((H5P_get(dxpl, "H5C_tag", &tag)) < 0)
+	HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "unable to query property value")
 
     if(cache_ptr->ignore_tags != TRUE) {
 #if H5C_DO_TAGGING_SANITY_CHECKS
         /* Perform some sanity checks to ensure that a correct tag is being applied */
-        if(H5C_verify_tag(entry_ptr->type->id, tag) < 0)
+        if(H5C_verify_tag(entry_ptr->type->id, tag.value, tag.globality) < 0)
             HGOTO_ERROR(H5E_CACHE, H5E_CANTTAG, FAIL, "tag verification failed")
 #endif
     } else {
@@ -9617,70 +9636,30 @@ H5C_tag_entry(H5C_t * cache_ptr, H5C_cache_entry_t * entry_ptr, hid_t dxpl_id)
            arbitrarily set it to something for the sake of passing the tests. 
            If the tag value is set, then we'll just let it get assigned without
            additional checking for correctness. */
-        if(!tag)
-            tag = H5AC__IGNORE_TAG;
+        if(!tag.value) {
+            tag.value = H5AC__IGNORE_TAG;
+            tag.globality = H5C_GLOBALITY_NONE;
+        } /* end if */
     } /* end if */
 
     /* Apply the tag to the entry */
-    entry_ptr->tag = tag;
+    entry_ptr->tag = tag.value;
 
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* H5C_tag_entry */
-
-
-/*-------------------------------------------------------------------------
- *
- * Function:    H5C_flush_tagged_entries
- *
- * WARNING:     Not yet tested or used anywhere. (written awhile ago,
- *              will keep it around in anticipation of being used in
- *              subsequent changes to support flushing individual objects).
- *
- * Purpose:     Flushes all entries with the specified tag to disk.
- *
- * Return:      FAIL if error is detected, SUCCEED otherwise.
- *
- * Programmer:  Mike McGreevy
- *              August 19, 2010
- *
- *-------------------------------------------------------------------------
- */
-static herr_t
-H5C_flush_tagged_entries(H5F_t * f, hid_t dxpl_id, H5C_t * cache_ptr, haddr_t tag)
-{
-    herr_t      ret_value = SUCCEED;
-
-    FUNC_ENTER_NOAPI(FAIL)
-
-    /* Assertions */
-    HDassert(0); /* This function is not yet used. We shouldn't be in here yet. */
-    HDassert(cache_ptr != NULL);
-    HDassert(cache_ptr->magic == H5C__H5C_T_MAGIC);
-
-    /* Mark all entries with specified tag */
-    if(H5C_mark_tagged_entries(cache_ptr, tag) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "Can't mark tagged entries")
-
-    /* Flush all marked entries */
-    if(H5C_flush_marked_entries(f, dxpl_id) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "Can't flush marked entries")
+    /* Apply the tag globality to the entry */
+    entry_ptr->globality = tag.globality;
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
-} /* H5C_flush_tagged_entries */
+} /* H5C__tag_entry */
 
 
+
 /*-------------------------------------------------------------------------
  *
- * Function:    H5C_mark_tagged_entries
+ * Function:    H5C__mark_tagged_entries
  *
- * WARNING:     Not yet tested or used anywhere. (written awhile ago,
- *              will keep it around in anticipation of being used in
- *              subsequent changes to support flushing individual objects).
- *
- * Purpose:     Set the flush marker on entries in the cache that have
- *              the specified tag.
+ * Purpose:     Set the flush marker on dirty entries in the cache that have
+ *              the specified tag, as well as all globally tagged entries.
  *
  * Return:      FAIL if error is detected, SUCCEED otherwise.
  *
@@ -9690,41 +9669,42 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t 
-H5C_mark_tagged_entries(H5C_t * cache_ptr, haddr_t tag) 
+H5C__mark_tagged_entries(H5C_t * cache_ptr, haddr_t tag)
 {
-    H5C_cache_entry_t *next_entry_ptr;  /* entry pointer */
-    unsigned u;                         /* Local index variable */
+    unsigned u;                 /* Local index variable */
 
-    FUNC_ENTER_NOAPI_NOINIT_NOERR
+    FUNC_ENTER_STATIC
 
-    /* Assertions */
-    HDassert(0); /* This function is not yet used. We shouldn't be in here yet. */
-    HDassert(cache_ptr != NULL);
+    /* Sanity check */
+    HDassert(cache_ptr);
     HDassert(cache_ptr->magic == H5C__H5C_T_MAGIC);
 
-    /* Iterate through entries, marking those with specified tag. */
+    /* Iterate through hash table entries, marking those with specified tag, as
+     * well as any major global entries which should always be flushed
+     * when flushing based on tag value */
     for(u = 0; u < H5C__HASH_TABLE_LEN; u++) {
-
-        next_entry_ptr = cache_ptr->index[u];
-        while(next_entry_ptr != NULL) {
-            if(next_entry_ptr->tag == tag)
-                next_entry_ptr->flush_marker = TRUE;
-
-            next_entry_ptr = next_entry_ptr->ht_next;
-        } /* end while */
-    } /* for */
+        H5C_cache_entry_t *entry_ptr;   /* Entry pointer */
+
+	entry_ptr = cache_ptr->index[u];
+	while(entry_ptr != NULL) {
+	    if((entry_ptr->tag == tag) || (entry_ptr->globality == H5C_GLOBALITY_MAJOR)) {
+		/* We only want to set the flush marker on entries that
+		 * actually need flushed (i.e., dirty ones) */
+		if(entry_ptr->is_dirty)
+		    entry_ptr->flush_marker = TRUE;
+	    } /* end if */
+
+	    entry_ptr = entry_ptr->ht_next;
+	} /* end while */
+    } /* end for */
 
     FUNC_LEAVE_NOAPI(SUCCEED)
-} /* H5C_mark_tagged_entries */
+} /* H5C__mark_tagged_entries */
 
 
 /*-------------------------------------------------------------------------
  *
- * Function:    H5C_flush_marked_entries
- *
- * WARNING:     Not yet tested or used anywhere. (written awhile ago,
- *              will keep it around in anticipation of being used in
- *              subsequent changes to support flushing individual objects).
+ * Function:    H5C__flush_marked_entries
  *
  * Purpose:     Flushes all marked entries in the cache.
  *
@@ -9736,14 +9716,13 @@ H5C_mark_tagged_entries(H5C_t * cache_ptr, haddr_t tag)
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5C_flush_marked_entries(H5F_t * f, hid_t dxpl_id)
+H5C__flush_marked_entries(H5F_t * f, hid_t dxpl_id)
 { 
     herr_t ret_value = SUCCEED;
 
-    FUNC_ENTER_NOAPI_NOINIT
+    FUNC_ENTER_STATIC
 
     /* Assertions */
-    HDassert(0); /* This function is not yet used. We shouldn't be in here yet. */
     HDassert(f != NULL);
 
     /* Flush all marked entries */
@@ -9752,7 +9731,7 @@ H5C_flush_marked_entries(H5F_t * f, hid_t dxpl_id)
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
-} /* H5C_flush_marked_entries */
+} /* H5C__flush_marked_entries */
 
 #if H5C_DO_TAGGING_SANITY_CHECKS
 
@@ -9769,8 +9748,8 @@ done:
  *
  *-------------------------------------------------------------------------
  */
-static herr_t
-H5C_verify_tag(int id, haddr_t tag) 
+herr_t
+H5C_verify_tag(int id, haddr_t tag, H5C_tag_globality_t globality)
 {
     herr_t ret_value = SUCCEED;
 
@@ -9784,7 +9763,6 @@ H5C_verify_tag(int id, haddr_t tag)
     else if(tag == H5AC__INVALID_TAG)
         HGOTO_ERROR(H5E_CACHE, H5E_CANTTAG, FAIL, "no metadata tag provided")
     else {
-
         /* Perform some sanity checks on tag value. Certain entry
          * types require certain tag values, so check that these
          * constraints are met. */
@@ -9793,37 +9771,45 @@ H5C_verify_tag(int id, haddr_t tag)
         if((id == H5AC_SUPERBLOCK_ID) || (id == H5AC_DRVRINFO_ID)) {
             if(tag != H5AC__SUPERBLOCK_TAG)
                 HGOTO_ERROR(H5E_CACHE, H5E_CANTTAG, FAIL, "superblock not tagged with H5AC__SUPERBLOCK_TAG")
-        }
+            if(globality != H5C_GLOBALITY_MAJOR)
+                HGOTO_ERROR(H5E_CACHE, H5E_CANTTAG, FAIL, "superblock/driver-info globality not marked with H5C_GLOBALITY_MAJOR")
+        } /* end if */
         else {
             if(tag == H5AC__SUPERBLOCK_TAG)
                 HGOTO_ERROR(H5E_CACHE, H5E_CANTTAG, FAIL, "H5AC__SUPERBLOCK_TAG applied to non-superblock entry")
-        }
+        } /* end else */
     
         /* Free Space Manager */
         if((id == H5AC_FSPACE_HDR_ID) || (id == H5AC_FSPACE_SINFO_ID)) {
             if(tag != H5AC__FREESPACE_TAG)
                 HGOTO_ERROR(H5E_CACHE, H5E_CANTTAG, FAIL, "freespace entry not tagged with H5AC__FREESPACE_TAG")
-        }
+            if(globality != H5C_GLOBALITY_MINOR)
+                HGOTO_ERROR(H5E_CACHE, H5E_CANTTAG, FAIL, "freespace entry globality not marked with H5C_GLOBALITY_MINOR")
+        } /* end if */
         else {
             if(tag == H5AC__FREESPACE_TAG)
                 HGOTO_ERROR(H5E_CACHE, H5E_CANTTAG, FAIL, "H5AC__FREESPACE_TAG applied to non-freespace entry")
-        }
+        } /* end else */
     
         /* SOHM */
         if((id == H5AC_SOHM_TABLE_ID) || (id == H5AC_SOHM_LIST_ID)) { 
             if(tag != H5AC__SOHM_TAG)
                 HGOTO_ERROR(H5E_CACHE, H5E_CANTTAG, FAIL, "sohm entry not tagged with H5AC__SOHM_TAG")
-        }
+            if(globality != H5C_GLOBALITY_MAJOR)
+                HGOTO_ERROR(H5E_CACHE, H5E_CANTTAG, FAIL, "sohm entry globality not marked with H5C_GLOBALITY_MAJOR")
+        } /* end if */
     
         /* Global Heap */
         if(id == H5AC_GHEAP_ID) {
             if(tag != H5AC__GLOBALHEAP_TAG)
                 HGOTO_ERROR(H5E_CACHE, H5E_CANTTAG, FAIL, "global heap not tagged with H5AC__GLOBALHEAP_TAG")
-        }
+            if(globality != H5C_GLOBALITY_MAJOR)
+                HGOTO_ERROR(H5E_CACHE, H5E_CANTTAG, FAIL, "global heap entry globality not marked with H5C_GLOBALITY_MAJOR")
+        } /* end if */
         else {
             if(tag == H5AC__GLOBALHEAP_TAG)
                 HGOTO_ERROR(H5E_CACHE, H5E_CANTTAG, FAIL, "H5AC__GLOBALHEAP_TAG applied to non-globalheap entry")
-        }
+        } /* end else */
     } /* end else */
 
 done:
@@ -9834,11 +9820,53 @@ done:
 
 /*-------------------------------------------------------------------------
  *
- * Function:    H5C_retag_copied_metadata
+ * Function:    H5C_flush_tagged_entries
+ *
+ * Purpose:     Flushes all entries with the specified tag to disk.
+ *
+ * Return:      FAIL if error is detected, SUCCEED otherwise.
+ *
+ * Programmer:  Mike McGreevy
+ *              August 19, 2010
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5C_flush_tagged_entries(H5F_t * f, hid_t dxpl_id, haddr_t tag)
+{
+    /* Variable Declarations */
+    H5C_t      *cache_ptr = NULL;
+    herr_t      ret_value = SUCCEED;
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Assertions */
+    HDassert(f);
+    HDassert(f->shared);
+
+    /* Get cache pointer */
+    cache_ptr = f->shared->cache;
+
+    /* Mark all entries with specified tag */
+    if(H5C__mark_tagged_entries(cache_ptr, tag) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "Can't mark tagged entries")
+
+    /* Flush all marked entries */
+    if(H5C__flush_marked_entries(f, dxpl_id) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "Can't flush marked entries")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C_flush_tagged_entries */
+
+
+/*-------------------------------------------------------------------------
+ *
+ * Function:    H5C_retag_entries
  *
  * Purpose:     Searches through cache index for all entries with the
- *              H5AC__COPIED_TAG, indicating that it was created as a 
- *              result of an object copy, and applies the provided tag.
+ *              value specified by src_tag and changes it to the value
+ *              specified by dest_tag.
  *
  * Return:      SUCCEED or FAIL.
  *
@@ -9848,30 +9876,29 @@ done:
  *-------------------------------------------------------------------------
  */
 void
-H5C_retag_copied_metadata(H5C_t * cache_ptr, haddr_t metadata_tag) 
+H5C_retag_entries(H5C_t * cache_ptr, haddr_t src_tag, haddr_t dest_tag) 
 {
     unsigned u;         /* Local index variable */
 
     FUNC_ENTER_NOAPI_NOINIT_NOERR
 
+    /* Sanity check */
     HDassert(cache_ptr);
 
-    /* Iterate through entries, retagging those with the H5AC__COPIED_TAG tag */
+    /* Iterate through entries, retagging those with the src_tag tag */
     for(u = 0; u < H5C__HASH_TABLE_LEN; u++) {
-        H5C_cache_entry_t *next_entry_ptr;      /* entry pointer */
-
-        next_entry_ptr = cache_ptr->index[u];
-        while(next_entry_ptr != NULL) {
-            if(cache_ptr->index[u] != NULL)
-                if((cache_ptr->index[u])->tag == H5AC__COPIED_TAG)
-                    (cache_ptr->index[u])->tag = metadata_tag;
-
-            next_entry_ptr = next_entry_ptr->ht_next;
-        } /* end while */
+        H5C_cache_entry_t *entry_ptr; /* entry pointer */
+
+	entry_ptr = cache_ptr->index[u];
+	while(entry_ptr) {
+	    if(entry_ptr->tag == src_tag)
+                entry_ptr->tag = dest_tag;
+	    entry_ptr = entry_ptr->ht_next;
+	} /* end while */
     } /* end for */
 
     FUNC_LEAVE_NOAPI_VOID
-} /* H5C_retag_copied_metadata */
+} /* H5C_retag_entries */
 
 
 /*-------------------------------------------------------------------------
diff --git a/src/H5Cprivate.h b/src/H5Cprivate.h
index a062214..d43c845 100644
--- a/src/H5Cprivate.h
+++ b/src/H5Cprivate.h
@@ -205,12 +205,17 @@
 #define H5C__FLUSH_MARKED_ENTRIES_FLAG		0x0080
 #define H5C__FLUSH_IGNORE_PROTECTED_FLAG	0x0100
 #define H5C__READ_ONLY_FLAG			0x0200
-#define H5C__FREE_FILE_SPACE_FLAG		0x0800
-#define H5C__TAKE_OWNERSHIP_FLAG		0x1000
-#define H5C__FLUSH_LAST_FLAG			0x2000
-#define H5C__FLUSH_COLLECTIVELY_FLAG		0x4000
+#define H5C__FREE_FILE_SPACE_FLAG		0x0400
+#define H5C__TAKE_OWNERSHIP_FLAG		0x0800
+#define H5C__FLUSH_LAST_FLAG			0x1000
+#define H5C__FLUSH_COLLECTIVELY_FLAG		0x2000
 #define H5C__DEL_FROM_SLIST_ON_DESTROY_FLAG     0x8000
 
+/* Definitions for cache "tag" property */
+#define H5C_TAG_NAME           "H5C_tag"
+#define H5C_TAG_SIZE           sizeof(H5C_tag_t)
+#define H5C_TAG_DEF            {(haddr_t)0, H5C_GLOBALITY_NONE}
+
 /* Debugging/sanity checking/statistics settings */
 #ifndef NDEBUG
 #define H5C_DO_SANITY_CHECKS		1
@@ -268,8 +273,20 @@
 /* Typedef for the main structure for the cache (defined in H5Cpkg.h) */
 typedef struct H5C_t H5C_t;
 
+/* Define enum for cache entry tag 'globality' value */
+typedef enum {
+    H5C_GLOBALITY_NONE=0, /* Non-global tag */
+    H5C_GLOBALITY_MINOR,  /* global, not flushed during single object flush */
+    H5C_GLOBALITY_MAJOR   /* global, needs flushed during single obect flush */
+} H5C_tag_globality_t;
+
+/* Cache entry tag structure */
+typedef struct H5C_tag_t {
+    haddr_t value;
+    H5C_tag_globality_t globality;
+} H5C_tag_t;
 
-/***************************************************************************
+/*
  *
  * Struct H5C_class_t
  *
@@ -1596,6 +1613,7 @@ typedef struct H5C_cache_entry_t {
     hbool_t			image_up_to_date;
     const H5C_class_t	      *	type;
     haddr_t		        tag;
+    H5C_tag_globality_t		globality;
     hbool_t			is_dirty;
     hbool_t			dirtied;
     hbool_t			is_protected;
@@ -1951,6 +1969,10 @@ H5_DLL herr_t H5C_dest(H5F_t *f, hid_t dxpl_id);
 H5_DLL herr_t H5C_expunge_entry(H5F_t *f, hid_t dxpl_id,
     const H5C_class_t *type, haddr_t addr, unsigned flags);
 H5_DLL herr_t H5C_flush_cache(H5F_t *f, hid_t dxpl_id, unsigned flags);
+H5_DLL herr_t H5C_flush_tagged_entries(H5F_t * f, hid_t dxpl_id, haddr_t tag); 
+#if H5C_DO_TAGGING_SANITY_CHECKS
+herr_t H5C_verify_tag(int id, haddr_t tag, H5C_tag_globality_t globality);
+#endif
 H5_DLL herr_t H5C_flush_to_min_clean(H5F_t *f, hid_t dxpl_id);
 H5_DLL herr_t H5C_get_cache_auto_resize_config(const H5C_t *cache_ptr,
     H5C_auto_size_ctl_t *config_ptr);
@@ -1992,7 +2014,8 @@ H5_DLL herr_t H5C_unprotect(H5F_t *f, hid_t dxpl_id, haddr_t addr, void *thing,
 H5_DLL herr_t H5C_validate_resize_config(H5C_auto_size_ctl_t *config_ptr,
     unsigned int tests);
 H5_DLL herr_t H5C_ignore_tags(H5C_t *cache_ptr);
-H5_DLL void H5C_retag_copied_metadata(H5C_t *cache_ptr, haddr_t metadata_tag);
+H5_DLL hbool_t H5C_get_ignore_tags(const H5C_t *cache_ptr);
+H5_DLL void H5C_retag_entries(H5C_t * cache_ptr, haddr_t src_tag, haddr_t dest_tag);
 H5_DLL herr_t H5C_get_entry_ring(const H5F_t *f, haddr_t addr, H5C_ring_t *ring);
 
 #ifdef H5_HAVE_PARALLEL
diff --git a/src/H5D.c b/src/H5D.c
index 5ef2e37..beb7cfe 100644
--- a/src/H5D.c
+++ b/src/H5D.c
@@ -917,3 +917,41 @@ done:
         FUNC_LEAVE_API(ret_value)
 } /* end H5Dset_extent() */
 
+
+/*-------------------------------------------------------------------------
+ * Function:    H5Dflush
+ *
+ * Purpose:     Flushes all buffers associated with a dataset.
+ *
+ * Return:      Non-negative on success, negative on failure
+ *
+ * Programmer:  Mike McGreevy
+ *              May 19, 2010
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Dflush(hid_t dset_id)
+{
+    H5D_t *dset; /* Dataset for this operation */
+    herr_t ret_value = SUCCEED; /* return value */
+
+    FUNC_ENTER_API(FAIL)
+    H5TRACE1("e", "i", dset_id);
+    
+    /* Check args */
+    if(NULL == (dset = (H5D_t *)H5I_object_verify(dset_id, H5I_DATASET)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a dataset")
+
+    /* Flush any dataset information still cached in memory */
+    if(H5D__flush_real(dset, H5AC_ind_read_dxpl_id) < 0)
+        HDONE_ERROR(H5E_DATASET, H5E_WRITEERROR, FAIL, "unable to flush cached dataset info")
+
+    /* Flush object's metadata to file */
+    if(H5O_flush_common(&dset->oloc, dset_id, H5AC_ind_read_dxpl_id) < 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTFLUSH, FAIL, "unable to flush dataset and object flush callback")
+
+done:
+    FUNC_LEAVE_API(ret_value)
+} /* H5Dflush */
+
diff --git a/src/H5Dint.c b/src/H5Dint.c
index 0355656..a5d214e 100644
--- a/src/H5Dint.c
+++ b/src/H5Dint.c
@@ -68,7 +68,7 @@ static herr_t H5D_build_extfile_prefix(const H5D_t *dset, hid_t dapl_id,
 static herr_t H5D__open_oid(H5D_t *dataset, hid_t dapl_id, hid_t dxpl_id);
 static herr_t H5D__init_storage(const H5D_io_info_t *io_info, hbool_t full_overwrite,
     hsize_t old_dim[]);
-
+static herr_t H5D__append_flush_setup(H5D_t *dset, hid_t dapl_id);
 
 /*********************/
 /* Package Variables */
@@ -1247,6 +1247,10 @@ H5D__create(H5F_t *file, hid_t type_id, const H5S_t *space, hid_t dcpl_id,
     /* Indicate that the layout information was initialized */
     layout_init = TRUE;
 
+    /* Set up append flush parameters for the dataset */
+    if(H5D__append_flush_setup(new_dset, dapl_id) < 0)
+	HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, NULL, "unable to set up flush append property")
+
     /* Set the external file prefix */
     if(H5D_build_extfile_prefix(new_dset, dapl_id, &new_dset->shared->extfile_prefix) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, NULL, "unable to initialize external file prefix")
@@ -1491,6 +1495,85 @@ done:
 } /* end H5D_open() */
 
 
+/*
+ *-------------------------------------------------------------------------
+ * Function:	H5D__flush_append_setup
+ *
+ * Purpose:	Set the append flush parameters for a dataset
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Vailin Choi
+ *		Wednesday, January 8, 2014
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5D__append_flush_setup(H5D_t *dset, hid_t dapl_id) 
+{
+    herr_t ret_value = SUCCEED;         /* return value */
+
+    FUNC_ENTER_STATIC
+
+    /* Check args */
+    HDassert(dset);
+    HDassert(dset->shared);
+
+    /* Set default append flush values */
+    HDmemset(&dset->shared->append_flush,  0, sizeof(dset->shared->append_flush));
+
+    /* If the dataset is chunked and there is a non-default DAPL */
+    if(dapl_id != H5P_DATASET_ACCESS_DEFAULT && dset->shared->layout.type == H5D_CHUNKED) {
+        H5P_genplist_t *dapl;               /* data access property list object pointer */
+
+	/* Get dataset access property list */
+	if(NULL == (dapl = (H5P_genplist_t *)H5I_object(dapl_id)))
+	    HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "can't find object for dapl ID");
+
+	/* Check if append flush property exists */
+	if(H5P_exist_plist(dapl, H5D_ACS_APPEND_FLUSH_NAME) > 0) {
+            H5D_append_flush_t info;
+
+	    /* Get append flush property */
+	    if(H5P_get(dapl, H5D_ACS_APPEND_FLUSH_NAME, &info) < 0)
+		HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get append flush info")
+	    if(info.ndims > 0) {
+                hsize_t curr_dims[H5S_MAX_RANK];	/* current dimension sizes */
+                hsize_t max_dims[H5S_MAX_RANK];		/* current dimension sizes */
+                int rank;                       	/* dataspace # of dimensions */
+                unsigned u;     			/* local index variable */
+
+		/* Get dataset rank */
+		if((rank = H5S_get_simple_extent_dims(dset->shared->space, curr_dims, max_dims)) < 0)
+		    HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't get dataset dimensions")
+		if(info.ndims != (unsigned)rank)
+		    HGOTO_ERROR(H5E_DATASET, H5E_BADVALUE, FAIL, "boundary dimension rank does not match dataset rank")
+
+		/* Validate boundary sizes */
+		for(u = 0; u < info.ndims; u++)
+		    if(info.boundary[u] != 0) /* when a non-zero boundary is set */
+			/* the dimension is extendible? */
+			if(max_dims[u] != H5S_UNLIMITED && max_dims[u] == curr_dims[u])
+			    break;
+
+                /* At least one boundary dimension is not extendible */
+		if(u != info.ndims)
+		    HGOTO_ERROR(H5E_DATASET, H5E_BADVALUE, FAIL, "boundary dimension is not valid")
+
+                /* Copy append flush settings */
+		dset->shared->append_flush.ndims = info.ndims;
+		dset->shared->append_flush.func = info.func;
+		dset->shared->append_flush.udata = info.udata;
+		HDmemcpy(dset->shared->append_flush.boundary, info.boundary, sizeof(info.boundary));
+	    } /* end if */
+	} /* end if */
+    } /* end if */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5D__append_flush_setup() */
+
+
 /*-------------------------------------------------------------------------
  * Function:	H5D__open_oid
  *
@@ -1555,6 +1638,10 @@ H5D__open_oid(H5D_t *dataset, hid_t dapl_id, hid_t dxpl_id)
     /* Indicate that the layout information was initialized */
     layout_init = TRUE;
 
+    /* Set up flush append property */
+    if(H5D__append_flush_setup(dataset, dapl_id))
+	HGOTO_ERROR(H5E_DATASET, H5E_CANTSET, FAIL, "unable to set up flush append property")
+
     /* Point at dataset's copy, to cache it for later */
     fill_prop = &dataset->shared->dcpl_cache.fill;
 
@@ -3083,28 +3170,28 @@ H5D_get_access_plist(H5D_t *dset)
     FUNC_ENTER_NOAPI_NOINIT
 
     /* Make a copy of the default dataset access property list */
-    if (NULL == (old_plist = (H5P_genplist_t *)H5I_object(H5P_LST_DATASET_ACCESS_ID_g)))
+    if(NULL == (old_plist = (H5P_genplist_t *)H5I_object(H5P_LST_DATASET_ACCESS_ID_g)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a property list")
-    if ((new_dapl_id = H5P_copy_plist(old_plist, TRUE)) < 0)
+    if((new_dapl_id = H5P_copy_plist(old_plist, TRUE)) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTINIT, FAIL, "can't copy dataset access property list")
-    if (NULL == (new_plist = (H5P_genplist_t *)H5I_object(new_dapl_id)))
+    if(NULL == (new_plist = (H5P_genplist_t *)H5I_object(new_dapl_id)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a property list")
 
-    /* If the dataset is chunked then copy the rdcc parameters */
-    if (dset->shared->layout.type == H5D_CHUNKED) {
-        if (H5P_set(new_plist, H5D_ACS_DATA_CACHE_NUM_SLOTS_NAME, &(dset->shared->cache.chunk.nslots)) < 0)
+    /* If the dataset is chunked then copy the rdcc & append flush parameters */
+    if(dset->shared->layout.type == H5D_CHUNKED) {
+        if(H5P_set(new_plist, H5D_ACS_DATA_CACHE_NUM_SLOTS_NAME, &(dset->shared->cache.chunk.nslots)) < 0)
             HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "can't set data cache number of slots")
-        if (H5P_set(new_plist, H5D_ACS_DATA_CACHE_BYTE_SIZE_NAME, &(dset->shared->cache.chunk.nbytes_max)) < 0)
+        if(H5P_set(new_plist, H5D_ACS_DATA_CACHE_BYTE_SIZE_NAME, &(dset->shared->cache.chunk.nbytes_max)) < 0)
             HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "can't set data cache byte size")
-        if (H5P_set(new_plist, H5D_ACS_PREEMPT_READ_CHUNKS_NAME, &(dset->shared->cache.chunk.w0)) < 0)
+        if(H5P_set(new_plist, H5D_ACS_PREEMPT_READ_CHUNKS_NAME, &(dset->shared->cache.chunk.w0)) < 0)
             HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "can't set preempt read chunks")
+        if(H5P_set(new_plist, H5D_ACS_APPEND_FLUSH_NAME, &dset->shared->append_flush) < 0)
+            HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "can't set append flush property")
     } /* end if */
 
-    /* Set the VDS view option */
+    /* Set the VDS view & printf gap options */
     if(H5P_set(new_plist, H5D_ACS_VDS_VIEW_NAME, &(dset->shared->layout.storage.u.virt.view)) < 0)
         HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "can't set VDS view")
-
-    /* Set the VDS printf gap option */
     if(H5P_set(new_plist, H5D_ACS_VDS_PRINTF_GAP_NAME, &(dset->shared->layout.storage.u.virt.printf_gap)) < 0)
         HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "can't set VDS printf gap")
 
diff --git a/src/H5Dpkg.h b/src/H5Dpkg.h
index f582367..c0b8b28 100644
--- a/src/H5Dpkg.h
+++ b/src/H5Dpkg.h
@@ -465,6 +465,7 @@ typedef struct H5D_shared_t {
         H5D_rdcc_t      chunk;          /* Information about chunked data */
     } cache;
 
+    H5D_append_flush_t  append_flush;   /* Append flush property information */
     char                *extfile_prefix; /* expanded external file prefix */
 } H5D_shared_t;
 
diff --git a/src/H5Dprivate.h b/src/H5Dprivate.h
index ab60a50..d1468dd 100644
--- a/src/H5Dprivate.h
+++ b/src/H5Dprivate.h
@@ -54,6 +54,7 @@
 #define H5D_ACS_PREEMPT_READ_CHUNKS_NAME    "rdcc_w0"       /* Preemption read chunks first */
 #define H5D_ACS_VDS_VIEW_NAME               "vds_view"      /* VDS view option */
 #define H5D_ACS_VDS_PRINTF_GAP_NAME         "vds_printf_gap" /* VDS printf gap size */
+#define H5D_ACS_APPEND_FLUSH_NAME    "append_flush"         /* Append flush actions */
 #define H5D_ACS_EFILE_PREFIX_NAME           "external file prefix" /* External file prefix */
 
 /* ======== Data transfer properties ======== */
@@ -151,6 +152,14 @@ typedef struct H5D_copy_file_ud_t {
     H5T_t *src_dtype;                   /* Copy of datatype for dataset */
 } H5D_copy_file_ud_t;
 
+/* Structure for dataset append flush property (H5Pset_append_flush) */
+typedef struct H5D_append_flush_t {
+    unsigned ndims;			/* The # of dimensions for "boundary" */
+    hsize_t boundary[H5S_MAX_RANK];	/* The dimension sizes for determining boundary */
+    H5D_append_cb_t func;		/* The callback function */
+    void *udata;			/* User data */
+} H5D_append_flush_t;
+
 
 /*****************************/
 /* Library Private Variables */
diff --git a/src/H5Dpublic.h b/src/H5Dpublic.h
index 0b6540c..e1555b9 100644
--- a/src/H5Dpublic.h
+++ b/src/H5Dpublic.h
@@ -109,6 +109,9 @@ typedef enum H5D_vds_view_t {
     H5D_VDS_LAST_AVAILABLE      = 1
 } H5D_vds_view_t;
 
+/* Callback for H5Pset_append_flush() in a dataset access property list */
+typedef herr_t (*H5D_append_cb_t)(hid_t dataset_id, hsize_t *cur_dims, void *op_data);
+
 /********************/
 /* Public Variables */
 /********************/
@@ -157,6 +160,7 @@ H5_DLL herr_t H5Dvlen_get_buf_size(hid_t dataset_id, hid_t type_id, hid_t space_
 H5_DLL herr_t H5Dfill(const void *fill, hid_t fill_type, void *buf,
         hid_t buf_type, hid_t space);
 H5_DLL herr_t H5Dset_extent(hid_t dset_id, const hsize_t size[]);
+H5_DLL herr_t H5Dflush(hid_t dset_id);
 H5_DLL herr_t H5Dscatter(H5D_scatter_func_t op, void *op_data, hid_t type_id,
     hid_t dst_space_id, void *dst_buf);
 H5_DLL herr_t H5Dgather(hid_t src_space_id, const void *src_buf, hid_t type_id,
diff --git a/src/H5Fint.c b/src/H5Fint.c
index f4e6550..9ca472d 100644
--- a/src/H5Fint.c
+++ b/src/H5Fint.c
@@ -171,6 +171,9 @@ H5F_get_access_plist(H5F_t *f, hbool_t app_ref)
         latest_format = TRUE;
     if(H5P_set(new_plist, H5F_ACS_LATEST_FORMAT_NAME, &latest_format) < 0)
         HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "can't set 'latest format' flag")
+    if(H5P_set(new_plist, H5F_ACS_OBJECT_FLUSH_CB_NAME, &(f->shared->object_flush)) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "can't set object flush callback")
+
     if(f->shared->efc)
         efc_size = H5F_efc_max_nfiles(f->shared->efc);
     if(H5P_set(new_plist, H5F_ACS_EFC_SIZE_NAME, &efc_size) < 0)
@@ -679,6 +682,10 @@ H5F_new(H5F_file_t *shared, unsigned flags, hid_t fcpl_id, hid_t fapl_id, H5FD_t
          */
         f->shared->use_tmp_space = !H5F_HAS_FEATURE(f, H5FD_FEAT_HAS_MPI);
 
+        /* Get object flush callback information */
+        if(H5P_get(plist, H5F_ACS_OBJECT_FLUSH_CB_NAME, &(f->shared->object_flush)) < 0)
+            HGOTO_ERROR(H5E_FILE, H5E_CANTGET, NULL, "can't get object flush cb info")
+
         /*
          * Create a metadata cache with the specified number of elements.
          * The cache might be created with a different number of elements and
@@ -2070,6 +2077,39 @@ done:
 
 
 /*-------------------------------------------------------------------------
+ * Function:    H5F_object_flush_cb
+ *
+ * Purpose:     To invoke the callback function for object flush that is set
+ *              in the file's access property list.
+ *
+ * Return:      Success:        SUCCEED
+ *              Failure:        FAIL
+ *
+ * Programmer:  Vailin Choi; October 2013
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5F_object_flush_cb(H5F_t *f, hid_t obj_id)
+{
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Sanity check */
+    HDassert(f);
+    HDassert(f->shared);
+
+    /* Invoke object flush callback if there is one */
+    if(f->shared->object_flush.func && f->shared->object_flush.func(obj_id, f->shared->object_flush.udata) < 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "object flush callback returns error")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5F_object_flush_cb() */
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5F__set_base_addr
  *
  * Purpose:	Quick and dirty routine to set the file's 'base_addr' value
diff --git a/src/H5Fio.c b/src/H5Fio.c
index d001bc0..1fb3459 100644
--- a/src/H5Fio.c
+++ b/src/H5Fio.c
@@ -199,3 +199,48 @@ done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5F_block_write() */
 
+
+/*-------------------------------------------------------------------------
+ * Function:    H5F_flush_tagged_metadata
+ *
+ * Purpose:     Flushes metadata with specified tag in the metadata cache 
+ *              to disk.
+ *
+ * Return:      Non-negative on success/Negative on failure
+ *
+ * Programmer:	Mike McGreevy
+ *              September 9, 2010
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5F_flush_tagged_metadata(H5F_t * f, haddr_t tag, hid_t dxpl_id)
+{
+    H5F_io_info_t fio_info;             /* I/O info for operation */
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Use tag to search for and flush associated metadata */
+    if(H5AC_flush_tagged_metadata(f, tag, dxpl_id)<0)
+        HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "unable to flush tagged metadata")
+
+    /* Set up I/O info for operation */
+    fio_info.f = f;
+
+    if(NULL == (fio_info.dxpl = (H5P_genplist_t *)H5I_object(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")
+
+    /* Flush file buffers to disk. */
+    if(H5FD_flush(f->shared->lf, dxpl_id, FALSE) < 0)
+        HGOTO_ERROR(H5E_IO, H5E_WRITEERROR, FAIL, "low level flush failed")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value);
+} /* end H5F_flush_tagged_metadata */
+
diff --git a/src/H5Fpkg.h b/src/H5Fpkg.h
index 06f0207..e2874d1 100644
--- a/src/H5Fpkg.h
+++ b/src/H5Fpkg.h
@@ -293,6 +293,9 @@ struct H5F_file_t {
 
     /* Metadata accumulator information */
     H5F_meta_accum_t accum;     /* Metadata accumulator info           	*/
+
+    /* Object flush info */
+    H5F_object_flush_t 	object_flush;		/* Information for object flush callback */
 };
 
 /*
diff --git a/src/H5Fprivate.h b/src/H5Fprivate.h
index 05c70d1..93965e0 100644
--- a/src/H5Fprivate.h
+++ b/src/H5Fprivate.h
@@ -459,6 +459,7 @@
 #define H5F_ACS_MULTI_TYPE_NAME                 "multi_type"    /* Data type in multi file driver */
 #define H5F_ACS_LATEST_FORMAT_NAME              "latest_format" /* 'Use latest format version' flag */
 #define H5F_ACS_WANT_POSIX_FD_NAME              "want_posix_fd" /* Internal: query the file descriptor from the core VFD, instead of the memory address */
+#define H5F_ACS_OBJECT_FLUSH_CB_NAME     	"object_flush_cb" 	 /* Object flush callback */
 #define H5F_ACS_EFC_SIZE_NAME                   "efc_size"      /* Size of external file cache */
 #define H5F_ACS_FILE_IMAGE_INFO_NAME            "file_image_info" /* struct containing initial file image and callback info */
 #define H5F_ACS_CORE_WRITE_TRACKING_FLAG_NAME       "core_write_tracking_flag" /* Whether or not core VFD backing store write tracking is enabled */
@@ -591,6 +592,12 @@ typedef struct H5F_file_t H5F_file_t;
 /* Block aggregation structure */
 typedef struct H5F_blk_aggr_t H5F_blk_aggr_t;
 
+/* Structure for object flush callback property (H5Pset_object_flush_cb)*/
+typedef struct H5F_object_flush_t {
+    H5F_flush_cb_t func;        /* The callback function */
+    void *udata;                /* User data */
+} H5F_object_flush_t;
+
 /* I/O Info for an operation */
 typedef struct H5F_io_info_t {
     const H5F_t *f;                     /* File object */
@@ -688,6 +695,12 @@ H5_DLL herr_t H5F_block_read(const H5F_t *f, H5FD_mem_t type, haddr_t addr,
 H5_DLL herr_t H5F_block_write(const H5F_t *f, H5FD_mem_t type, haddr_t addr,
                 size_t size, hid_t dxpl_id, const void *buf);
 
+/* Functions that flush or evict */
+H5_DLL herr_t H5F_flush_tagged_metadata(H5F_t * f, haddr_t tag, hid_t dxpl_id);
+
+/* Routine to invoke callback function upon object flush */
+H5_DLL herr_t H5F_object_flush_cb(H5F_t *f, hid_t obj_id);
+
 /* Address-related functions */
 H5_DLL void H5F_addr_encode(const H5F_t *f, uint8_t **pp, haddr_t addr);
 H5_DLL void H5F_addr_encode_len(size_t addr_len, uint8_t **pp, haddr_t addr);
diff --git a/src/H5Fpublic.h b/src/H5Fpublic.h
index eba9b12..6fa18e1 100644
--- a/src/H5Fpublic.h
+++ b/src/H5Fpublic.h
@@ -175,6 +175,9 @@ typedef enum H5F_file_space_type_t {
     H5F_FILE_SPACE_NTYPES	    /* must be last */
 } H5F_file_space_type_t;
 
+/* Callback for H5Pset_object_flush_cb() in a file access property list */
+typedef herr_t (*H5F_flush_cb_t)(hid_t object_id, void *udata);
+
 
 #ifdef __cplusplus
 extern "C" {
diff --git a/src/H5Oflush.c b/src/H5Oflush.c
new file mode 100644
index 0000000..0bec096
--- /dev/null
+++ b/src/H5Oflush.c
@@ -0,0 +1,132 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by The HDF Group.                                               *
+ * Copyright by the Board of Trustees of the University of Illinois.         *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5.  The full HDF5 copyright notice, including     *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the files COPYING and Copyright.html.  COPYING can be found at the root   *
+ * of the source code distribution tree; Copyright.html can be found at the  *
+ * root level of an installed copy of the electronic HDF5 document set and   *
+ * is linked from the top-level documents page.  It can also be found at     *
+ * http://hdfgroup.org/HDF5/doc/Copyright.html.  If you do not have          *
+ * access to either file, you may request a copy from help@hdfgroup.org.     *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+/*-------------------------------------------------------------------------
+ *
+ * Created:     H5Oflush.c
+ *              Aug 19, 2010
+ *              Mike McGreevy <mamcgree@hdfgroup.org>
+ *
+ * Purpose:     Object flush/refresh routines.
+ *
+ *-------------------------------------------------------------------------
+ */
+
+/****************/
+/* Module Setup */
+/****************/
+
+#include "H5Omodule.h"          /* This source code file is part of the H5O module */
+
+/***********/
+/* Headers */
+/***********/
+
+#include "H5private.h"      /* Generic Functions */
+#include "H5Dprivate.h"     /* Datasets */
+#include "H5Eprivate.h"     /* Errors   */
+#include "H5Fprivate.h"     /* Files    */
+#include "H5Gprivate.h"        /* Groups    */
+#include "H5Iprivate.h"        /* IDs    */
+#include "H5Opkg.h"         /* Objects  */
+
+/********************/
+/* Local Prototypes */
+/********************/
+static herr_t H5O_oh_tag(const H5O_loc_t *oloc, hid_t dxpl_id, haddr_t *tag);
+
+/*************/
+/* Functions */
+/*************/
+
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5O_flush_common
+ *
+ * Purpose:    	Flushes the object's metadata
+ *		Invokes the user-defined callback if there is one.
+ *
+ * Return:  	Non-negative on success, negative on failure
+ *
+ * Programmer:  Vailin Choi; Dec 2013
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5O_flush_common(H5O_loc_t *oloc, hid_t obj_id, hid_t dxpl_id)
+{
+    haddr_t 	tag = 0;
+    herr_t      ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Retrieve tag for object */
+    if(H5O_oh_tag(oloc, dxpl_id, &tag) < 0)
+        HGOTO_ERROR(H5E_OHDR, H5E_CANTFLUSH, FAIL, "unable to flush object metadata")
+
+    /* Flush metadata based on tag value of the object */
+    if(H5F_flush_tagged_metadata(oloc->file, tag, dxpl_id) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTFLUSH, FAIL, "unable to flush tagged metadata")
+
+    /* Check to invoke callback */
+    if(H5F_object_flush_cb(oloc->file, obj_id) < 0)
+	HGOTO_ERROR(H5E_OHDR, H5E_CANTFLUSH, FAIL, "unable to do object flush callback")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5O_flush_common() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5O_oh_tag
+ *
+ * Purpose:     Get object header's address--tag value for the object
+ *
+ * Return:  	Success:    Non-negative
+ *          	Failure:    Negative
+ *
+ * Programmer: Mike McGreevy
+ *             May 19, 2010
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5O_oh_tag(const H5O_loc_t *oloc, hid_t dxpl_id, haddr_t *tag)
+{
+    H5O_t       *oh = NULL;             /* Object header */
+    herr_t      ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Check args */
+    HDassert(oloc);
+
+    /* Get object header for object */
+    if(NULL == (oh = H5O_protect(oloc, dxpl_id, H5AC__READ_ONLY_FLAG)))
+        HGOTO_ERROR(H5E_OHDR, H5E_CANTPROTECT, FAIL, "unable to protect object's object header")
+
+    /* Get object header's address (i.e. the tag value for this object) */
+    if(HADDR_UNDEF == (*tag = H5O_OH_GET_ADDR(oh)))
+        HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, FAIL, "unable to get address of object header")
+
+done:
+    /* Unprotect object header on failure */
+    if(oh && H5O_unprotect(oloc, dxpl_id, oh, H5AC__NO_FLAGS_SET) < 0)
+        HDONE_ERROR(H5E_OHDR, H5E_CANTUNPROTECT, FAIL, "unable to release object header")
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5O_oh_tag() */
+
diff --git a/src/H5Oprivate.h b/src/H5Oprivate.h
index 17ab665..9ad8662 100644
--- a/src/H5Oprivate.h
+++ b/src/H5Oprivate.h
@@ -902,6 +902,9 @@ H5_DLL int H5O_msg_get_chunkno(const H5O_loc_t *loc, unsigned type_id, hid_t dxp
 H5_DLL herr_t H5O_msg_lock(const H5O_loc_t *loc, unsigned type_id, hid_t dxpl_id);
 H5_DLL herr_t H5O_msg_unlock(const H5O_loc_t *loc, unsigned type_id, hid_t dxpl_id);
 
+/* Object metadata flush/refresh routines */
+H5_DLL herr_t H5O_flush_common(H5O_loc_t *oloc, hid_t obj_id, hid_t dxpl_id);
+
 /* Object copying routines */
 H5_DLL herr_t H5O_copy_header_map(const H5O_loc_t *oloc_src, H5O_loc_t *oloc_dst /*out */,
     hid_t dxpl_id, H5O_copy_t *cpy_info, hbool_t inc_depth,
diff --git a/src/H5Pdapl.c b/src/H5Pdapl.c
index 6407d4c..aa58dc4 100644
--- a/src/H5Pdapl.c
+++ b/src/H5Pdapl.c
@@ -73,6 +73,9 @@
 #define H5D_ACS_VDS_PRINTF_GAP_DEF              (hsize_t)0
 #define H5D_ACS_VDS_PRINTF_GAP_ENC              H5P__encode_hsize_t
 #define H5D_ACS_VDS_PRINTF_GAP_DEC              H5P__decode_hsize_t
+/* Definition for append flush */
+#define H5D_ACS_APPEND_FLUSH_SIZE            	sizeof(H5D_append_flush_t)
+#define H5D_ACS_APPEND_FLUSH_DEF             	{0,{0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},NULL,NULL}
 /* Definitions for external file prefix */
 #define H5D_ACS_EFILE_PREFIX_SIZE               sizeof(char *)
 #define H5D_ACS_EFILE_PREFIX_DEF                NULL /*default is no prefix */
@@ -157,9 +160,9 @@ const H5P_libclass_t H5P_CLS_DACC[1] = {{
 /*******************/
 
 /* Property value defaults */
+static const H5D_append_flush_t H5D_def_append_flush_g = H5D_ACS_APPEND_FLUSH_DEF;       /* Default setting for append flush */
 static const char *H5D_def_efile_prefix_g = H5D_ACS_EFILE_PREFIX_DEF; /* Default external file prefix string */
 
-
 
 /*-------------------------------------------------------------------------
  * Function:    H5P__dacc_reg_prop
@@ -212,6 +215,12 @@ H5P__dacc_reg_prop(H5P_genclass_t *pclass)
             NULL, NULL, NULL, NULL) < 0)
         HGOTO_ERROR(H5E_PLIST, H5E_CANTINSERT, FAIL, "can't insert property into class")
 
+    /* Register info for append flush */
+    /* (Note: this property should not have an encode/decode callback -QAK) */
+    if(H5P_register_real(pclass, H5D_ACS_APPEND_FLUSH_NAME, H5D_ACS_APPEND_FLUSH_SIZE, &H5D_def_append_flush_g, 
+             NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL) < 0)
+         HGOTO_ERROR(H5E_PLIST, H5E_CANTINSERT, FAIL, "can't insert property into class")
+
     /* Register property for external file prefix */
     if(H5P_register_real(pclass, H5D_ACS_EFILE_PREFIX_NAME, H5D_ACS_EFILE_PREFIX_SIZE, &H5D_def_efile_prefix_g, 
             NULL, H5D_ACS_EFILE_PREFIX_SET, H5D_ACS_EFILE_PREFIX_GET, H5D_ACS_EFILE_PREFIX_ENC, H5D_ACS_EFILE_PREFIX_DEC,
@@ -1076,6 +1085,125 @@ done:
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5Pset_append_flush
+ *
+ * Purpose:	Sets the boundary, callback function, and user data in the
+ *		property list.
+ *		"ndims": number of array elements for boundary
+ *		"boundary": used to determine whether the current dimension hits 
+ *			  a boundary; if so, invoke the callback function and
+ *			  flush the dataset.
+ *		"func": the callback function to invoke when the boundary is hit
+ *		"udata": the user data to pass as parameter with the callback function
+ *	
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Vailin Choi; Dec 2013
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Pset_append_flush(hid_t plist_id, unsigned ndims, const hsize_t *boundary, H5D_append_cb_t func, void *udata)
+{
+    H5P_genplist_t *plist;      	/* Property list pointer */
+    H5D_append_flush_t info;            /* Property for append flush parameters */
+    unsigned u;				/* Local index variable */
+    herr_t ret_value = SUCCEED;   	/* Return value */
+
+    FUNC_ENTER_API(FAIL)
+    H5TRACE5("e", "iIu*hx*x", plist_id, ndims, boundary, func, udata);
+
+    /* Check arguments */
+    if(0 == ndims)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "dimensionality cannot be zero")
+    if(ndims > H5S_MAX_RANK)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "dimensionality is too large")
+    if(!boundary)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no boundary dimensions specified")
+
+    /* Check if the callback function is NULL and the user data is non-NULL.
+     * This is almost certainly an error as the user data will not be used. */
+    if(!func && udata)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "callback is NULL while user data is not")
+ 
+    /* Get the plist structure */
+    if(NULL == (plist = H5P_object_verify(plist_id, H5P_DATASET_ACCESS)))
+        HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "can't find object for ID")
+
+    /* Set up values */
+    info.ndims = ndims;
+    info.func = func;
+    info.udata = udata;
+
+    HDmemset(info.boundary, 0, sizeof(info.boundary));
+    /* boundary can be 0 to indicate no boundary is set */
+    for(u = 0; u < ndims; u++) {
+        if(boundary[u] != (boundary[u] & 0xffffffff)) /* negative value (including H5S_UNLIMITED) */
+            HGOTO_ERROR(H5E_ARGS, H5E_BADRANGE, FAIL, "all boundary dimensions must be less than 2^32")
+        info.boundary[u] = boundary[u]; /* Store user's boundary dimensions */
+    } /* end for */
+
+    /* Set values */
+    if(H5P_set(plist, H5D_ACS_APPEND_FLUSH_NAME, &info) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "can't set append flush")
+
+done:
+    FUNC_LEAVE_API(ret_value)
+} /* H5Pset_append_flush() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5Pget_append_flush()
+ *
+ * Purpose:	Retrieves the boundary, callback function and user data set in 
+ *		property list.
+ *		Note that the # of boundary sizes to retrieve will not exceed
+ *		the parameter "ndims" and the ndims set previously via 
+ *		H5Pset_append_flush().
+ *	
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Vailin Choi; Dec 2013
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Pget_append_flush(hid_t plist_id, unsigned ndims, hsize_t boundary[], H5D_append_cb_t *func, void **udata)
+{
+    H5P_genplist_t *plist;      /* property list pointer */
+    H5D_append_flush_t  info;
+    unsigned u;			/* local index variable */
+    herr_t ret_value = SUCCEED; /* return value */
+
+    FUNC_ENTER_API(FAIL)
+    H5TRACE5("e", "iIu*h*x**x", plist_id, ndims, boundary, func, udata);
+
+    /* Get the plist structure */
+    if(NULL == (plist = H5P_object_verify(plist_id, H5P_DATASET_ACCESS)))
+        HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "can't find object for ID")
+
+    /* Retrieve info for append flush */
+    if(H5P_get(plist, H5D_ACS_APPEND_FLUSH_NAME, &info) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get object flush callback")
+
+    /* Assign return values */
+    if(boundary) {
+	HDmemset(boundary, 0, ndims * sizeof(hsize_t));
+	if(info.ndims > 0)
+	    for(u = 0; u < info.ndims && u < ndims; u++)
+		boundary[u] = info.boundary[u];
+    } /* end if */
+    if(func)
+	*func = info.func;
+    if(udata)
+	*udata = info.udata;
+
+done:
+    FUNC_LEAVE_API(ret_value)
+} /* H5Pget_append_flush() */
+
+
+/*-------------------------------------------------------------------------
  * Function:    H5Pset_efile_prefix
  *
  * Purpose:     Set a prefix to be used for any external files.
@@ -1165,3 +1293,4 @@ H5Pget_efile_prefix(hid_t plist_id, char *prefix, size_t size)
 done:
     FUNC_LEAVE_API(ret_value)
 } /* end H5Pget_efile_prefix() */
+
diff --git a/src/H5Pdxpl.c b/src/H5Pdxpl.c
index 9353094..e685c65 100644
--- a/src/H5Pdxpl.c
+++ b/src/H5Pdxpl.c
@@ -273,7 +273,7 @@ static const void *H5D_def_vlen_alloc_info_g = H5D_XFER_VLEN_ALLOC_INFO_DEF;   /
 static const H5MM_free_t H5D_def_vlen_free_g = H5D_XFER_VLEN_FREE_DEF;         /* Default value for vlen free function */
 static const void *H5D_def_vlen_free_info_g = H5D_XFER_VLEN_FREE_INFO_DEF;     /* Default value for vlen free information */
 static const size_t H5D_def_hyp_vec_size_g = H5D_XFER_HYPER_VECTOR_SIZE_DEF;   /* Default value for vector size */
-static const haddr_t H5D_def_metadata_tag_g = H5AC_METADATA_TAG_DEF;              /* Default value for metadata tag */
+static const H5C_tag_t H5D_def_tag_g = H5C_TAG_DEF;                            /* Default value for cache entry tag */
 static const H5FD_mpio_xfer_t H5D_def_io_xfer_mode_g = H5D_XFER_IO_XFER_MODE_DEF;      /* Default value for I/O transfer mode */
 static const H5FD_mpio_chunk_opt_t H5D_def_mpio_chunk_opt_mode_g = H5D_XFER_MPIO_CHUNK_OPT_HARD_DEF;
 static const H5FD_mpio_collective_opt_t H5D_def_mpio_collective_opt_mode_g = H5D_XFER_MPIO_COLLECTIVE_OPT_DEF;
@@ -325,9 +325,8 @@ H5P__dxfr_reg_prop(H5P_genclass_t *pclass)
             NULL, NULL, NULL, NULL) < 0)
         HGOTO_ERROR(H5E_PLIST, H5E_CANTINSERT, FAIL, "can't insert property into class")
 
-    /* Register the metadata tag property */
-    /* (Note: this property should not have an encode/decode callback -QAK) */
-    if(H5P_register_real(pclass, H5AC_METADATA_TAG_NAME, H5AC_METADATA_TAG_SIZE, &H5D_def_metadata_tag_g, 
+    /* Register the cache tag property */
+    if(H5P_register_real(pclass, H5C_TAG_NAME, H5C_TAG_SIZE, &H5D_def_tag_g,
             NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL) < 0)
         HGOTO_ERROR(H5E_PLIST, H5E_CANTINSERT, FAIL, "can't insert property into class")
 
diff --git a/src/H5Pfapl.c b/src/H5Pfapl.c
index 1fbc3b8..a315f92 100644
--- a/src/H5Pfapl.c
+++ b/src/H5Pfapl.c
@@ -178,6 +178,9 @@
 #define H5F_ACS_CORE_WRITE_TRACKING_PAGE_SIZE_DEF       524288
 #define H5F_ACS_CORE_WRITE_TRACKING_PAGE_SIZE_ENC       H5P__encode_size_t
 #define H5F_ACS_CORE_WRITE_TRACKING_PAGE_SIZE_DEC       H5P__decode_size_t
+/* Definition for object flush callback */
+#define H5F_ACS_OBJECT_FLUSH_CB_SIZE		sizeof(H5F_object_flush_t)
+#define H5F_ACS_OBJECT_FLUSH_CB_DEF             {NULL, NULL}
 #ifdef H5_HAVE_PARALLEL
 /* Definition of collective metadata read mode flag */
 #define H5F_ACS_COLL_MD_READ_FLAG_SIZE   sizeof(H5P_coll_md_read_flag_t)
@@ -292,6 +295,7 @@ static const unsigned H5F_def_efc_size_g = H5F_ACS_EFC_SIZE_DEF;
 static const H5FD_file_image_info_t H5F_def_file_image_info_g = H5F_ACS_FILE_IMAGE_INFO_DEF;                 /* Default file image info and callbacks */
 static const hbool_t H5F_def_core_write_tracking_flag_g = H5F_ACS_CORE_WRITE_TRACKING_FLAG_DEF;              /* Default setting for core VFD write tracking */
 static const size_t H5F_def_core_write_tracking_page_size_g = H5F_ACS_CORE_WRITE_TRACKING_PAGE_SIZE_DEF;     /* Default core VFD write tracking page size */
+static const H5F_object_flush_t H5F_def_object_flush_cb_g = H5F_ACS_OBJECT_FLUSH_CB_DEF;      /* Default setting for object flush callback */
 #ifdef H5_HAVE_PARALLEL
 static const H5P_coll_md_read_flag_t H5F_def_coll_md_read_flag_g = H5F_ACS_COLL_MD_READ_FLAG_DEF;  /* Default setting for the collective metedata read flag */
 static const hbool_t H5F_def_coll_md_write_flag_g = H5F_ACS_COLL_MD_WRITE_FLAG_DEF;  /* Default setting for the collective metedata write flag */
@@ -452,6 +456,12 @@ H5P__facc_reg_prop(H5P_genclass_t *pclass)
             NULL, NULL, NULL, NULL) < 0)
         HGOTO_ERROR(H5E_PLIST, H5E_CANTINSERT, FAIL, "can't insert property into class")
 
+    /* Register object flush callback */
+    /* (Note: this property should not have an encode/decode callback -QAK) */
+    if(H5P_register_real(pclass, H5F_ACS_OBJECT_FLUSH_CB_NAME, H5F_ACS_OBJECT_FLUSH_CB_SIZE, &H5F_def_object_flush_cb_g, 
+            NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTINSERT, FAIL, "can't insert property into class")
+
 #ifdef H5_HAVE_PARALLEL
     /* Register the metadata collective read flag */
     if(H5P_register_real(pclass, H5_COLL_MD_READ_FLAG_NAME, H5F_ACS_COLL_MD_READ_FLAG_SIZE, &H5F_def_coll_md_read_flag_g, 
@@ -3510,6 +3520,91 @@ done:
     FUNC_LEAVE_API(ret_value)
 } /* end H5Pget_core_write_tracking() */
 
+
+/*-------------------------------------------------------------------------
+ * Function:	H5Pset_obj_flush_cb
+ *
+ * Purpose:	Sets the callback function to invoke and the user data when an
+ *		object flush occurs in the file.
+ *	
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Vailin Choi; Dec 2013
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Pset_object_flush_cb(hid_t plist_id, H5F_flush_cb_t func, void *udata)
+{
+    H5P_genplist_t *plist;      /* Property list pointer */
+    H5F_object_flush_t flush_info;
+    herr_t ret_value = SUCCEED;   /* return value */
+
+    FUNC_ENTER_API(FAIL)
+    H5TRACE3("e", "ix*x", plist_id, func, udata);
+
+    /* Check if the callback function is NULL and the user data is non-NULL.
+     * This is almost certainly an error as the user data will not be used. */
+    if(!func && udata)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "callback is NULL while user data is not")
+
+    /* Get the plist structure */
+    if(NULL == (plist = H5P_object_verify(plist_id, H5P_FILE_ACCESS)))
+        HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "can't find object for ID")
+
+    /* Update property list */
+    flush_info.func = func;
+    flush_info.udata = udata;
+
+    /* Set values */
+    if(H5P_set(plist, H5F_ACS_OBJECT_FLUSH_CB_NAME, &flush_info) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "can't set object flush callback")
+
+done:
+    FUNC_LEAVE_API(ret_value)
+} /* H5Pset_obj_flush_cb() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5Pget_obj_flush_cb
+ *
+ * Purpose:	Retrieves the callback function and user data set in the
+ *		property list for an object flush.
+ *	
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Vailin Choi; Dec 2013
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Pget_object_flush_cb(hid_t plist_id, H5F_flush_cb_t *func, void **udata)
+{
+    H5P_genplist_t *plist;      /* Property list pointer */
+    H5F_object_flush_t flush_info;
+    herr_t ret_value = SUCCEED;   /* return value */
+
+    FUNC_ENTER_API(FAIL)
+    H5TRACE3("e", "i*x**x", plist_id, func, udata);
+
+    /* Get the plist structure */
+    if(NULL == (plist = H5P_object_verify(plist_id, H5P_FILE_ACCESS)))
+        HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "can't find object for ID")
+
+    /* Retrieve the callback function and user data */
+    if(H5P_get(plist, H5F_ACS_OBJECT_FLUSH_CB_NAME, &flush_info) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get object flush callback")
+
+    /* Assign return value */
+    if(func)
+	*func = flush_info.func;
+    if(udata)
+	*udata = flush_info.udata;
+
+done:
+    FUNC_LEAVE_API(ret_value)
+} /* H5Pget_obj_flush_cb() */
+
 #ifdef H5_HAVE_PARALLEL
 
 /*-------------------------------------------------------------------------
diff --git a/src/H5Ppublic.h b/src/H5Ppublic.h
index 67727ce..0318c8f 100644
--- a/src/H5Ppublic.h
+++ b/src/H5Ppublic.h
@@ -351,6 +351,8 @@ H5_DLL herr_t H5Pget_file_image_callbacks(hid_t fapl_id,
        H5FD_file_image_callbacks_t *callbacks_ptr);
 H5_DLL herr_t H5Pset_core_write_tracking(hid_t fapl_id, hbool_t is_enabled, size_t page_size);
 H5_DLL herr_t H5Pget_core_write_tracking(hid_t fapl_id, hbool_t *is_enabled, size_t *page_size);
+H5_DLL herr_t H5Pset_object_flush_cb(hid_t plist_id, H5F_flush_cb_t func, void *udata);
+H5_DLL herr_t H5Pget_object_flush_cb(hid_t plist_id, H5F_flush_cb_t *func, void **udata);
 #ifdef H5_HAVE_PARALLEL
 H5_DLL herr_t H5Pset_all_coll_metadata_ops(hid_t plist_id, hbool_t is_collective);
 H5_DLL herr_t H5Pget_all_coll_metadata_ops(hid_t plist_id, hbool_t *is_collective);
@@ -408,6 +410,10 @@ H5_DLL herr_t H5Pset_virtual_view(hid_t plist_id, H5D_vds_view_t view);
 H5_DLL herr_t H5Pget_virtual_view(hid_t plist_id, H5D_vds_view_t *view);
 H5_DLL herr_t H5Pset_virtual_printf_gap(hid_t plist_id, hsize_t gap_size);
 H5_DLL herr_t H5Pget_virtual_printf_gap(hid_t plist_id, hsize_t *gap_size);
+H5_DLL herr_t H5Pset_append_flush(hid_t plist_id, unsigned ndims,
+    const hsize_t boundary[], H5D_append_cb_t func, void *udata);
+H5_DLL herr_t H5Pget_append_flush(hid_t plist_id, unsigned dims,
+    hsize_t boundary[], H5D_append_cb_t *func, void **udata);
 H5_DLL herr_t H5Pset_efile_prefix(hid_t dapl_id, const char* prefix);
 H5_DLL ssize_t H5Pget_efile_prefix(hid_t dapl_id, char* prefix /*out*/, size_t size);
 
diff --git a/src/Makefile.am b/src/Makefile.am
index 5d72fc5..81fec77 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -81,7 +81,7 @@ libhdf5_la_SOURCES= H5.c H5checksum.c H5dbg.c H5system.c H5timer.c H5trace.c \
         H5O.c H5Oainfo.c H5Oalloc.c H5Oattr.c \
         H5Oattribute.c H5Obogus.c H5Obtreek.c H5Ocache.c H5Ochunk.c \
         H5Ocont.c H5Ocopy.c H5Odbg.c H5Odrvinfo.c H5Odtype.c H5Oefl.c \
-        H5Ofill.c H5Ofsinfo.c H5Oginfo.c \
+        H5Ofill.c H5Oflush.c H5Ofsinfo.c H5Oginfo.c \
         H5Olayout.c \
         H5Olinfo.c H5Olink.c H5Omessage.c H5Omtime.c \
         H5Oname.c H5Onull.c H5Opline.c H5Orefcount.c \