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authorQuincey Koziol <koziol@hdfgroup.org>2015-09-09 06:33:03 (GMT)
committerQuincey Koziol <koziol@hdfgroup.org>2015-09-09 06:33:03 (GMT)
commit26baf1a805b27e2ca34edf313a85f4a6d4081da1 (patch)
tree7404adc256ca658eb84b691bcf0a82e62589757d /src/H5Cprivate.h
parent2132f544596c2e12e86cebf4c1cc6b1d38ffa80d (diff)
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[svn-r27710] Description:
Bring the "metadata rings" code from its branch (mdc_rings_v2) to the trunk. (This change will support the page buffering feature) Tested on: MacOSX/64 10.10.5 (amazon) w/serial & parallel (h5committest forthcoming)
Diffstat (limited to 'src/H5Cprivate.h')
-rw-r--r--src/H5Cprivate.h77
1 files changed, 77 insertions, 0 deletions
diff --git a/src/H5Cprivate.h b/src/H5Cprivate.h
index 3cd74c1..2a3efc9 100644
--- a/src/H5Cprivate.h
+++ b/src/H5Cprivate.h
@@ -1115,6 +1115,60 @@ typedef herr_t (*H5C_log_flush_func_t)(H5C_t *cache_ptr, haddr_t addr,
/****************************************************************************
*
+ * H5C_ring_t & associated #defines
+ *
+ * The metadata cache uses the concept of rings to order the flushes of
+ * classes of entries. In this arrangement, each entry in the cache is
+ * assigned to a ring, and on flush, the members of the outermost ring
+ * are flushed first, followed by the next outermost, and so on with the
+ * members of the innermost ring being flushed last.
+ *
+ * Note that flush dependencies are used to order flushes within rings.
+ *
+ * Note also that at the conceptual level, rings are argueably superfluous,
+ * as a similar effect could be obtained via the flush dependency mechanism.
+ * However, this would require all entries in the cache to participate in a
+ * flush dependency -- with the implied setup and takedown overhead and
+ * added complexity. Further, the flush ordering between rings need only
+ * be enforced on flush operations, and thus the use of flush dependencies
+ * instead would apply unecessary constraints on flushes under normal
+ * operating circumstances.
+ *
+ * As of this writing, all metadata entries pretaining to data sets and
+ * groups must be flushed first, and are thus assigned to the outermost
+ * ring.
+ *
+ * Free space managers managing file space must be flushed next,
+ * and are assigned to the second outermost ring.
+ *
+ * The object header and associated chunks used to implement superblock
+ * extension messages must be flushed next, and are thus assigned to
+ * the third outermost ring.
+ *
+ * The superblock proper must be flushed last, and is thus assigned to
+ * the innermost ring.
+ *
+ * The H5C_ring_t and the associated #defines below are used to define
+ * the rings. Each entry must be assigned to the appropriate ring on
+ * insertion or protect.
+ *
+ * Note that H5C_ring_t was originally an enumerated type. It was
+ * converted to an integer and a set of #defines for convenience in
+ * debugging.
+ */
+
+#define H5C_RING_UNDEFINED 0 /* shouldn't appear in the cache */
+#define H5C_RING_USER 1 /* outermost ring */
+#define H5C_RING_FSM 2
+#define H5C_RING_SBE 4 /* temporarily merged with H5C_RING_SB */
+#define H5C_RING_SB 4 /* innermost ring */
+#define H5C_RING_NTYPES 5
+
+typedef int H5C_ring_t;
+
+
+/****************************************************************************
+ *
* structure H5C_cache_entry_t
*
* Instances of the H5C_cache_entry_t structure are used to store cache
@@ -1376,6 +1430,25 @@ typedef herr_t (*H5C_log_flush_func_t)(H5C_t *cache_ptr, haddr_t addr,
* is in the process of being flushed and destroyed.
*
*
+ * Fields supporting rings for flush ordering:
+ *
+ * All entries in the metadata cache are assigned to a ring. On cache
+ * flush, all entries in the outermost ring are flushed first, followed
+ * by all members of the next outermost ring, and so on until the
+ * innermost ring is flushed. Note that this ordering is ONLY applied
+ * in flush and serialize calls. Rings are ignored during normal operations
+ * in which entries are flushed as directed by the replacement policy.
+ *
+ * See the header comment on H5C_ring_t above for further details.
+ *
+ * Note that flush dependencies (see below) are used to order flushes
+ * within rings. Unlike rings, flush dependencies are applied to ALL
+ * writes, not just those triggered by flush or serialize calls.
+ *
+ * ring: Instance of H5C_ring_t indicating the ring to which this
+ * entry is assigned.
+ *
+ *
* Fields supporting the 'flush dependency' feature:
*
* Entries in the cache may have a 'flush dependency' on another entry in the
@@ -1543,6 +1616,9 @@ typedef struct H5C_cache_entry_t {
hbool_t flush_in_progress;
hbool_t destroy_in_progress;
+ /* fields supporting rings for purposes of flush ordering */
+ H5C_ring_t ring;
+
/* fields supporting the 'flush dependency' feature: */
struct H5C_cache_entry_t * flush_dep_parent;
uint64_t child_flush_dep_height_rc[H5C__NUM_FLUSH_DEP_HEIGHTS];
@@ -1917,6 +1993,7 @@ 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 herr_t H5C_get_entry_ring(const H5F_t *f, haddr_t addr, H5C_ring_t *ring);
#ifdef H5_HAVE_PARALLEL
H5_DLL herr_t H5C_apply_candidate_list(H5F_t *f, hid_t dxpl_id,