[svn-r12374] Purpose:

1) Check in potential fix to unreproduceable bug in t_cache observed on
   Cobalt

2) Check in code supporting added pinned entry features in the metadata
   cache.


Description:

1) Elena encountered a bug in t_cache when running on Cobalt.  On
   investigation I found a potential race condition in t_cache that
   could explain her observation.

2) Quincey requested additions to the metadata cache allowing renaming
   of pinned entryies, and marking of pinned or protected entries as
   dirty.


Solution:

1) Modified t_cache.c to prevent the potential race condition.  Elena
   was unable to reproduce the bug on Cobalt, so we don't know if my
   fix actually addressed the problem.

2) Added code supporting the requested functions.  The changes were
   relatively trivial, but required substantial new test code.


Platforms tested:

h5committest, serial test on heping, parallel test on phoenix.


Misc. update:

1 files changed, 97 insertions, 0 deletions

diff --git a/src/H5C.c b/src/H5C.c
index fcc9e49..15fc671 100644
--- a/src/H5C.c
+++ b/src/H5C.c
@@ -2607,6 +2607,7 @@ H5C_create(size_t		      max_cache_size,
         ((cache_ptr->epoch_markers)[i]).size		= (size_t)0;
         ((cache_ptr->epoch_markers)[i]).type		= &epoch_marker_class;
         ((cache_ptr->epoch_markers)[i]).is_dirty	= FALSE;
+        ((cache_ptr->epoch_markers)[i]).dirtied		= FALSE;
         ((cache_ptr->epoch_markers)[i]).is_protected	= FALSE;
         ((cache_ptr->epoch_markers)[i]).is_pinned	= FALSE;
         ((cache_ptr->epoch_markers)[i]).in_slist	= FALSE;
@@ -3732,6 +3733,10 @@ done:
  *		Added initialization for the new is_pinned field of the
  *		H5C_cache_entry_t structure.
  *
+ *		JRM -- 5/3/06
+ *		Added initialization for the new dirtied field of the 
+ *		H5C_cache_entry_t structure.
+ *
  *-------------------------------------------------------------------------
  */
 
@@ -3789,6 +3794,9 @@ H5C_insert_entry(H5F_t * 	     f,
     /* newly inserted entries are assumed to be dirty */
     entry_ptr->is_dirty = TRUE;
 
+    /* not protected, so can't be dirtied */
+    entry_ptr->dirtied  = FALSE;
+
     if ( (type->size)(f, thing, &(entry_ptr->size)) < 0 ) {
 
         HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGETSIZE, FAIL, \
@@ -4364,6 +4372,79 @@ done:
 
 
 /*-------------------------------------------------------------------------
+ * Function:    H5C_mark_pinned_or_protected_entry_dirty
+ *
+ * Purpose:	Mark a pinned or protected entry as dirty.  The target entry 
+ * 		MUST be either pinned or protected, and MAY be both.
+ *
+ * 		At present, this funtion does not support size change.
+ *
+ * 		In the protected case, this call is the functional 
+ * 		equivalent of setting the H5C__DIRTIED_FLAG on an unprotect
+ * 		call.
+ *
+ * 		In the pinned but not protected case, if the entry is not 
+ * 		already dirty, the function places function marks the entry
+ * 		dirty and places it on the skip list.
+ *
+ * Return:      Non-negative on success/Negative on failure
+ *
+ * Programmer:  John Mainzer
+ *              5/15/06
+ *
+ * Modifications:
+ *
+ * 		None
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5C_mark_pinned_or_protected_entry_dirty(H5C_t * cache_ptr,
+                                         void *  thing)
+{
+    herr_t              ret_value = SUCCEED;    /* Return value */
+    H5C_cache_entry_t *	entry_ptr;
+
+    FUNC_ENTER_NOAPI(H5C_mark_pinned_or_protected_entry_dirty, FAIL)
+
+    HDassert( cache_ptr );
+    HDassert( cache_ptr->magic == H5C__H5C_T_MAGIC );
+    HDassert( thing );
+
+    entry_ptr = (H5C_cache_entry_t *)thing;
+
+    if ( entry_ptr->is_protected ) {
+
+        /* set the dirtied flag */
+        entry_ptr->dirtied = TRUE;
+
+    } else if ( entry_ptr->is_pinned ) {
+
+        /* mark the entry as dirty if it isn't already */
+        entry_ptr->is_dirty = TRUE;
+
+
+        if ( ! (entry_ptr->in_slist) ) {
+
+            H5C__INSERT_ENTRY_IN_SLIST(cache_ptr, entry_ptr)
+        }
+
+        H5C__UPDATE_STATS_FOR_DIRTY_PIN(cache_ptr, entry_ptr)
+
+    } else {
+
+            HGOTO_ERROR(H5E_CACHE, H5E_CANTMARKDIRTY, FAIL, \
+                        "Entry is neither pinned nor protected??")
+    }
+
+done:
+
+    FUNC_LEAVE_NOAPI(ret_value)
+
+} /* H5C_mark_pinned_or_protected_entry_dirty() */
+
+
+/*-------------------------------------------------------------------------
  *
  * Function:    H5C_rename_entry
  *
@@ -4621,6 +4702,10 @@ done:
  *		JRM -- 10/22/05
  *		Hand optimizations.
  *
+ *		JRM -- 5/3/06
+ *		Added code to set the new dirtied field in 
+ *		H5C_cache_entry_t to FALSE prior to return.
+ *
  *-------------------------------------------------------------------------
  */
 
@@ -4791,6 +4876,8 @@ H5C_protect(H5F_t *	        f,
 
     entry_ptr->is_protected = TRUE;
 
+    entry_ptr->dirtied = FALSE;
+
     ret_value = thing;
 
     H5C__UPDATE_CACHE_HIT_RATE_STATS(cache_ptr, hit)
@@ -5857,6 +5944,11 @@ done:
  *		Unpdated function to pin and unpin entries as directed via
  *		the new H5C__PIN_ENTRY_FLAG and H5C__UNPIN_ENTRY_FLAG flags.
  *
+ *		JRM -- 5/3/06
+ *		Added code to make use of the new dirtied field in 
+ *		H5C_cache_entry_t.  If this field is TRUE, it is the
+ *		equivalent of setting the H5C__DIRTIED_FLAG.
+ *
  *-------------------------------------------------------------------------
  */
 herr_t
@@ -5910,6 +6002,11 @@ H5C_unprotect(H5F_t *		  f,
     HDassert( entry_ptr->addr == addr );
     HDassert( entry_ptr->type == type );
 
+    /* also set the dirtied variable if the dirtied field is set in 
+     * the entry.
+     */
+    dirtied |= entry_ptr->dirtied;
+
 #if H5C_DO_EXTREME_SANITY_CHECKS
         if ( H5C_validate_lru_list(cache_ptr) < 0 ) {