[svn-r7528] Purpose:

    Bug Fix

Description:
    The FPHDF5 code couldn't create a dataset then access it. Turns out
    that the "O_find_in_ohdr" code was protecting the object header which
    pulls it into the cache then unprotecting it. However, this caused
    the cache entry to be blown away and THEN we'd try to reread the
    entry (via AC_protect) but it didn't have all of the data that the
    find_in_ohdr function decodes for us decoded. It was also kind of
    unnecessary since we can just protect then call O_find_in_ohdr.

Solution:
    Removed the AC_protect and AC_unprotect from O_find_in_ohdr. Called
    AC_protect before calling the O_find_in_ohdr function.

Platforms tested:
    Linux (Fortran, C++)
    IRIX (parallel, Fortran)
    Sun (Fortran)

Misc. update:

1 files changed, 51 insertions, 55 deletions

diff --git a/src/H5O.c b/src/H5O.c
index 7915a8a..f436e29 100644
--- a/src/H5O.c
+++ b/src/H5O.c
@@ -62,8 +62,8 @@ static void * H5O_read_real(H5G_entry_t *ent, const H5O_class_t *type,
 static herr_t H5O_share(H5F_t *f, hid_t dxpl_id, const H5O_class_t *type, const void *mesg,
 			 H5HG_t *hobj/*out*/);
 #endif /* NOT_YET */
-static unsigned H5O_find_in_ohdr(H5F_t *f, hid_t dxpl_id, haddr_t addr,
-			     const H5O_class_t **type_p, int sequence);
+static unsigned H5O_find_in_ohdr(H5F_t *f, hid_t dxpl_id, H5O_t *oh,
+                                 const H5O_class_t **type_p, int sequence);
 static int H5O_modify_real(H5G_entry_t *ent, const H5O_class_t *type,
     int overwrite, unsigned flags, unsigned update_time, const void *mesg,
     hid_t dxpl_id);
@@ -471,7 +471,6 @@ H5O_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, const void UNUSED * _udata1,
     unsigned	chunkno;
     haddr_t	chunk_addr;
     size_t	chunk_size;
-    H5O_cont_t	*cont = NULL;
     uint8_t	flags;
 
     FUNC_ENTER_NOAPI(H5O_load, NULL);
@@ -518,7 +517,6 @@ H5O_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, const void UNUSED * _udata1,
 
     /* read each chunk from disk */
     while (H5F_addr_defined(chunk_addr)) {
-
 	/* increase chunk array size */
 	if (oh->nchunks >= oh->alloc_nchunks) {
 	    unsigned na = oh->alloc_nchunks + H5O_NCHUNKS;
@@ -542,9 +540,7 @@ H5O_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, const void UNUSED * _udata1,
 	    HGOTO_ERROR(H5E_OHDR, H5E_READERROR, NULL, "unable to read object header data");
 	
 	/* load messages from this chunk */
-	for (p = oh->chunk[chunkno].image;
-	     p < oh->chunk[chunkno].image + chunk_size;
-	     p += mesg_size) {
+	for (p = oh->chunk[chunkno].image; p < oh->chunk[chunkno].image + chunk_size; p += mesg_size) {
 	    UINT16DECODE(p, id);
 	    UINT16DECODE(p, mesg_size);
 	    assert (mesg_size==H5O_ALIGN (mesg_size));
@@ -580,22 +576,20 @@ H5O_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, const void UNUSED * _udata1,
 		oh->mesg[mesgno].chunkno = chunkno;
 	    }
 	}
-	assert(p == oh->chunk[chunkno].image + chunk_size);
-
-	/* decode next object header continuation message */
-	for (chunk_addr=HADDR_UNDEF;
-	     !H5F_addr_defined(chunk_addr) && curmesg < oh->nmesgs;
-	     curmesg++) {
-	    if (H5O_CONT_ID == oh->mesg[curmesg].type->id) {
-		uint8_t *p2 = oh->mesg[curmesg].raw;
-
-		cont = (H5O_CONT->decode) (f, dxpl_id, p2, NULL);
-		oh->mesg[curmesg].native = cont;
-		chunk_addr = cont->addr;
-		chunk_size = cont->size;
-		cont->chunkno = oh->nchunks;	/*the next chunk to allocate */
-	    }
-	}
+
+        assert(p == oh->chunk[chunkno].image + chunk_size);
+
+        /* decode next object header continuation message */
+        for (chunk_addr = HADDR_UNDEF; !H5F_addr_defined(chunk_addr) && curmesg < oh->nmesgs; ++curmesg) {
+            if (H5O_CONT_ID == oh->mesg[curmesg].type->id) {
+                H5O_cont_t *cont = NULL;
+                cont = (H5O_CONT->decode) (f, dxpl_id, oh->mesg[curmesg].raw, NULL);
+                oh->mesg[curmesg].native = cont;
+                chunk_addr = cont->addr;
+                chunk_size = cont->size;
+                cont->chunkno = oh->nchunks;	/*the next chunk to allocate */
+            }
+        }
     }
 
     /* Set return value */
@@ -1503,17 +1497,22 @@ done:
  *		Aug  6 1997
  *
  * Modifications:
- *
+ *      Bill Wendling, 2003-09-30
+ *      Protect the object header and pass it into the H5O_find_in_ohdr
+ *      function. This is done because the H5O_find_in_ohdr used to
+ *      protect the ohdr, find the message, and then unprotect it. This
+ *      saves time and also helps the FPHDF5 stuff, where unprotecting
+ *      actually destroys the object in the cache.
  *-------------------------------------------------------------------------
  */
 static void *
 H5O_read_real(H5G_entry_t *ent, const H5O_class_t *type, int sequence, void *mesg, hid_t dxpl_id)
 {
-    H5O_t		*oh = NULL;
-    int		idx;
-    H5G_cache_t		*cache = NULL;
-    H5G_type_t		cache_type;
-    void		*ret_value = NULL;
+    H5O_t          *oh = NULL;
+    int             idx;
+    H5G_cache_t    *cache = NULL;
+    H5G_type_t      cache_type;
+    void           *ret_value = NULL;
 
     FUNC_ENTER_NOINIT(H5O_read_real);
 
@@ -1526,6 +1525,7 @@ H5O_read_real(H5G_entry_t *ent, const H5O_class_t *type, int sequence, void *mes
 
     /* can we get it from the symbol table entry? */
     cache = H5G_ent_cache(ent, &cache_type);
+
     if (H5O_fast_g[cache_type]) {
 	ret_value = (H5O_fast_g[cache_type]) (cache, type, mesg);
 	if (ret_value)
@@ -1533,13 +1533,14 @@ H5O_read_real(H5G_entry_t *ent, const H5O_class_t *type, int sequence, void *mes
 	H5E_clear(NULL); /*don't care, try reading from header */
     }
 
-    /* can we get it from the object header? */
-    if ((idx = H5O_find_in_ohdr(ent->file, dxpl_id, ent->header, &type, sequence)) < 0)
-	HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, NULL, "unable to find message in object header");
-
     /* copy the message to the user-supplied buffer */
     if (NULL == (oh = H5AC_protect(ent->file, dxpl_id, H5AC_OHDR, ent->header, NULL, NULL, H5AC_READ)))
 	HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "unable to load object header");
+
+    /* can we get it from the object header? */
+    if ((idx = H5O_find_in_ohdr(ent->file, dxpl_id, oh, &type, sequence)) < 0)
+	HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, NULL, "unable to find message in object header");
+
     if (oh->mesg[idx].flags & H5O_FLAG_SHARED) {
 	/*
 	 * If the message is shared then then the native pointer points to an
@@ -1589,29 +1590,30 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5O_find_in_ohdr
+ * Function:    H5O_find_in_ohdr
  *
- * Purpose:	Find a message in the object header without consulting
- *		a symbol table entry.
+ * Purpose:     Find a message in the object header without consulting
+ *              a symbol table entry.
  *
- * Return:	Success:	Index number of message.
+ * Return:      Success:    Index number of message.
+ *              Failure:    Negative
  *
- *		Failure:	Negative
- *
- * Programmer:	Robb Matzke
- *		matzke@llnl.gov
- *		Aug  6 1997
+ * Programmer:  Robb Matzke
+ *              matzke@llnl.gov
+ *              Aug  6 1997
  *
  * Modifications:
- *		Robb Matzke, 1999-07-28
- *		The ADDR argument is passed by value.
+ *      Robb Matzke, 1999-07-28
+ *      The ADDR argument is passed by value.
+ *
+ *      Bill Wendling, 2003-09-30
+ *      Modified so that the object header needs to be AC_protected
+ *      before calling this function.
  *-------------------------------------------------------------------------
  */
 static unsigned
-H5O_find_in_ohdr(H5F_t *f, hid_t dxpl_id, haddr_t addr, const H5O_class_t **type_p,
-		 int sequence)
+H5O_find_in_ohdr(H5F_t *f, hid_t dxpl_id, H5O_t *oh, const H5O_class_t **type_p, int sequence)
 {
-    H5O_t		*oh = NULL;
     unsigned		u;
     const H5O_class_t	*type = NULL;
     unsigned		ret_value;
@@ -1620,13 +1622,8 @@ H5O_find_in_ohdr(H5F_t *f, hid_t dxpl_id, haddr_t addr, const H5O_class_t **type
 
     /* Check args */
     assert(f);
-    assert(H5F_addr_defined(addr));
     assert(type_p);
 
-    /* Load the object header */
-    if (NULL == (oh = H5AC_protect(f, dxpl_id, H5AC_OHDR, addr, NULL, NULL, H5AC_READ)))
-	HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, UFAIL, "unable to load object header");
-
     /* Scan through the messages looking for the right one */
     for (u = 0; u < oh->nmesgs; u++) {
 	if (*type_p && (*type_p)->id != oh->mesg[u].type->id)
@@ -1634,6 +1631,7 @@ H5O_find_in_ohdr(H5F_t *f, hid_t dxpl_id, haddr_t addr, const H5O_class_t **type
 	if (--sequence < 0)
             break;
     }
+
     if (sequence >= 0)
 	HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, UFAIL, "unable to find object header message");
 
@@ -1646,6 +1644,7 @@ H5O_find_in_ohdr(H5F_t *f, hid_t dxpl_id, haddr_t addr, const H5O_class_t **type
     } else {
 	type = oh->mesg[u].type;
     }
+
     if (NULL == oh->mesg[u].native) {
 	assert(type->decode);
 	oh->mesg[u].native = (type->decode) (f, dxpl_id, oh->mesg[u].raw, NULL);
@@ -1663,9 +1662,6 @@ H5O_find_in_ohdr(H5F_t *f, hid_t dxpl_id, haddr_t addr, const H5O_class_t **type
     ret_value=u;
 
 done:
-    if (oh && H5AC_unprotect(f, dxpl_id, H5AC_OHDR, addr, oh, FALSE) != SUCCEED)
-        HDONE_ERROR(H5E_OHDR, H5E_PROTECT, UFAIL, "unable to release object header");
-
     FUNC_LEAVE_NOAPI(ret_value);
 }