[svn-r17649] Description:

	Refactor v2 B-trees to pin the B-tree header in the cache instead of
using separate reference counted data structure.

Tested on:
        FreeBSD/32 6.3 (duty) in debug mode
        FreeBSD/64 6.3 (liberty) w/C++ & FORTRAN, in debug mode
        Linux/32 2.6 (jam) w/PGI compilers, w/default API=1.8.x,
                w/C++ & FORTRAN, w/threadsafe, in debug mode
        Linux/64-amd64 2.6 (smirom) w/Intel compilers, w/default API=1.6.x,
                w/C++ & FORTRAN, in production mode
        Solaris/32 2.10 (linew) w/deprecated symbols disabled, w/C++ & FORTRAN,
                w/szip filter, in production mode
        Linux/64-ia64 2.6 (cobalt) w/Intel compilers, w/C++ & FORTRAN,
                in production mode
        Linux/64-ia64 2.4 (tg-login3) w/parallel, w/FORTRAN, in debug mode
        Linux/64-amd64 2.6 (abe) w/parallel, w/FORTRAN, in production mode
        Mac OS X/32 10.6.1 (amazon) in debug mode
        Mac OS X/32 10.6.1 (amazon) w/C++ & FORTRAN, w/threadsafe,
                in production mode

1 files changed, 18 insertions, 29 deletions

diff --git a/src/H5B2test.c b/src/H5B2test.c
index 3fa5d27..a8a36ba 100644
--- a/src/H5B2test.c
+++ b/src/H5B2test.c
@@ -271,13 +271,10 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5B2_get_node_info_test(H5F_t *f, hid_t dxpl_id, const H5B2_class_t *type, haddr_t addr,
-    void *udata, H5B2_node_info_test_t *ninfo)
+H5B2_get_node_info_test(H5F_t *f, hid_t dxpl_id, const H5B2_class_t *type,
+    haddr_t addr, void *udata, H5B2_node_info_test_t *ninfo)
 {
-    H5B2_t	*bt2=NULL;              /* Pointer to the B-tree header */
-    H5RC_t      *bt2_shared=NULL;       /* Pointer to ref-counter for shared B-tree info */
-    H5B2_shared_t *shared;              /* Pointer to B-tree's shared information */
-    hbool_t     incr_rc=FALSE;          /* Flag to indicate that we've incremented the B-tree's shared info reference count */
+    H5B2_t	*bt2 = NULL;            /* Pointer to the B-tree header */
     H5B2_node_ptr_t curr_node_ptr;      /* Node pointer info for current node */
     unsigned    depth;                  /* Current depth of the tree */
     int         cmp;                    /* Comparison value of records */
@@ -292,31 +289,20 @@ H5B2_get_node_info_test(H5F_t *f, hid_t dxpl_id, const H5B2_class_t *type, haddr
     HDassert(H5F_addr_defined(addr));
 
     /* Look up the B-tree header */
-    if (NULL == (bt2 = (H5B2_t *)H5AC_protect(f, dxpl_id, H5AC_BT2_HDR, addr, type, NULL, H5AC_READ)))
+    if(NULL == (bt2 = (H5B2_t *)H5AC_protect(f, dxpl_id, H5AC_BT2_HDR, addr, type, NULL, H5AC_READ)))
 	HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to load B-tree header")
 
-    /* Safely grab pointer to reference counted shared B-tree info, so we can release the B-tree header if necessary */
-    bt2_shared=bt2->shared;
-    H5RC_INC(bt2_shared);
-    incr_rc=TRUE;
-
-    /* Get the pointer to the shared B-tree info */
-    shared = (H5B2_shared_t *)H5RC_GET_OBJ(bt2_shared);
-    HDassert(shared);
+    /* Set file pointer for this B-tree operation */
+    bt2->f = f;
 
     /* Make copy of the root node pointer to start search with */
     curr_node_ptr = bt2->root;
 
     /* Current depth of the tree */
-    depth = shared->depth;
-
-    /* Release header */
-    if(H5AC_unprotect(f, dxpl_id, H5AC_BT2_HDR, addr, bt2, H5AC__NO_FLAGS_SET) < 0)
-        HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree header info")
-    bt2 = NULL;
+    depth = bt2->depth;
 
     /* Check for empty tree */
-    if(curr_node_ptr.node_nrec==0)
+    if(0 == curr_node_ptr.node_nrec)
         HGOTO_ERROR(H5E_BTREE, H5E_NOTFOUND, FAIL, "B-tree has no records")
 
     /* Walk down B-tree to find record or leaf node where record is located */
@@ -326,11 +312,11 @@ H5B2_get_node_info_test(H5F_t *f, hid_t dxpl_id, const H5B2_class_t *type, haddr
         H5B2_node_ptr_t next_node_ptr;      /* Node pointer info for next node */
 
         /* Lock B-tree current node */
-        if(NULL == (internal = H5B2_protect_internal(f, dxpl_id, bt2_shared, curr_node_ptr.addr, curr_node_ptr.node_nrec, depth, H5AC_READ)))
+        if(NULL == (internal = H5B2_protect_internal(f, dxpl_id, bt2, curr_node_ptr.addr, curr_node_ptr.node_nrec, depth, H5AC_READ)))
             HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to load B-tree internal node")
 
         /* Locate node pointer for child */
-        cmp = H5B2_locate_record(shared->type, internal->nrec, shared->nat_off, internal->int_native, udata, &idx);
+        cmp = H5B2_locate_record(bt2->type, internal->nrec, bt2->nat_off, internal->int_native, udata, &idx);
         if(cmp > 0)
             idx++;
 
@@ -366,11 +352,11 @@ H5B2_get_node_info_test(H5F_t *f, hid_t dxpl_id, const H5B2_class_t *type, haddr
         H5B2_leaf_t *leaf;          /* Pointer to leaf node in B-tree */
 
         /* Lock B-tree leaf node */
-        if(NULL == (leaf = (H5B2_leaf_t *)H5AC_protect(f, dxpl_id, H5AC_BT2_LEAF, curr_node_ptr.addr, &(curr_node_ptr.node_nrec), bt2_shared, H5AC_READ)))
+        if(NULL == (leaf = (H5B2_leaf_t *)H5AC_protect(f, dxpl_id, H5AC_BT2_LEAF, curr_node_ptr.addr, &(curr_node_ptr.node_nrec), bt2, H5AC_READ)))
             HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to load B-tree internal node")
 
         /* Locate record */
-        cmp = H5B2_locate_record(shared->type, leaf->nrec, shared->nat_off, leaf->leaf_native, udata, &idx);
+        cmp = H5B2_locate_record(bt2->type, leaf->nrec, bt2->nat_off, leaf->leaf_native, udata, &idx);
 
         /* Unlock current node */
         if(H5AC_unprotect(f, dxpl_id, H5AC_BT2_LEAF, curr_node_ptr.addr, leaf, H5AC__NO_FLAGS_SET) < 0)
@@ -386,9 +372,12 @@ H5B2_get_node_info_test(H5F_t *f, hid_t dxpl_id, const H5B2_class_t *type, haddr
     ninfo->nrec = curr_node_ptr.node_nrec;
 
 done:
-    /* Check if we need to decrement the reference count for the B-tree's shared info */
-    if(incr_rc)
-        H5RC_DEC(bt2_shared);
+    /* Release header */
+    if(bt2) {
+        bt2->f = NULL;
+        if(H5AC_unprotect(f, dxpl_id, H5AC_BT2_HDR, addr, bt2, H5AC__NO_FLAGS_SET) < 0)
+            HDONE_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree header info")
+    } /* end if */
 
     FUNC_LEAVE_NOAPI(ret_value)
 } /* H5B2_get_node_info_test() */