[svn-r8844] Purpose:

    Bug fix

Description:
    The "shared" raw B-tree node can get freed before all the B-tree nodes
had been flushed out to disk and released by the cache.

Solution:
    Implement a simple reference counting wrapper for objects in the library
and use it to hold the shared raw B-tree nodes so they aren't freed before all
references to them in memory are released.

Platforms tested:
    Solaris 2.7 (arabica)
    FreeBSD 4.10 (sleipnir)
    IRIX64 6.5 (modei4)

1 files changed, 40 insertions, 4 deletions

diff --git a/src/H5Distore.c b/src/H5Distore.c
index 0bab89d..09c025c 100644
--- a/src/H5Distore.c
+++ b/src/H5Distore.c
@@ -146,6 +146,7 @@ static haddr_t H5D_istore_get_addr(H5F_t *f, hid_t dxpl_id, const H5O_layout_t *
     const hssize_t offset[], H5D_istore_ud1_t *_udata);
 static void *H5D_istore_chunk_alloc(size_t size, const H5O_pline_t *pline);
 static void *H5D_istore_chunk_xfree(void *chk, const H5O_pline_t *pline);
+static herr_t H5D_istore_page_free (void *page);
 
 /* B-tree iterator callbacks */
 static int H5D_istore_iter_allocated(H5F_t *f, hid_t dxpl_id, void *left_key, haddr_t addr,
@@ -278,9 +279,13 @@ H5D_istore_get_page(H5F_t UNUSED *f, const void *_udata)
 
     assert(udata);
     assert(udata->mesg);
-    assert(udata->mesg->u.chunk.raw_page);
+    assert(udata->mesg->u.chunk.rc_page);
 
-    FUNC_LEAVE_NOAPI(udata->mesg->u.chunk.raw_page);
+    /* Increment reference count on B-tree node */
+    H5RC_INC(udata->mesg->u.chunk.rc_page);
+
+    /* Get the pointer to the ref-count object */
+    FUNC_LEAVE_NOAPI(udata->mesg->u.chunk.rc_page);
 } /* end H5D_istore_get_page() */
 
 
@@ -898,6 +903,7 @@ H5D_istore_init (H5F_t *f, H5D_t *dset)
     size_t		sizeof_rkey;    /* Single raw key size */
     size_t              size;           /* Raw B-tree node size */
     H5D_rdcc_t	*rdcc = &(dset->cache.chunk);
+    void        *page;                  /* Buffer for raw B-tree node */
     herr_t      ret_value=SUCCEED;       /* Return value */
     
     FUNC_ENTER_NOAPI(H5D_istore_init, FAIL);
@@ -919,9 +925,13 @@ H5D_istore_init (H5F_t *f, H5D_t *dset)
     assert(sizeof_rkey);
     size = H5B_nodesize(f, H5B_ISTORE, NULL, sizeof_rkey);
     assert(size);
-    if(NULL==(dset->layout.u.chunk.raw_page=H5FL_BLK_MALLOC(chunk_page,size)))
+    if(NULL==(page=H5FL_BLK_MALLOC(chunk_page,size)))
 	HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed for B-tree page")
 
+    /* Make page buffer reference counted */
+    if(NULL==(dset->layout.u.chunk.rc_page=H5RC_create(page,H5D_istore_page_free)))
+	HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, FAIL, "can't create ref-count wrapper for page")
+
 done:
     FUNC_LEAVE_NOAPI(ret_value);
 } /* end H5D_istore_init() */
@@ -1217,7 +1227,8 @@ H5D_istore_dest (H5F_t *f, hid_t dxpl_id, H5D_t *dset)
     HDmemset (rdcc, 0, sizeof(H5D_rdcc_t));
 
     /* Free the raw B-tree node buffer */
-    H5FL_BLK_FREE(chunk_page,dset->layout.u.chunk.raw_page);
+    if(H5RC_DEC(dset->layout.u.chunk.rc_page)<0)
+	HGOTO_ERROR (H5E_IO, H5E_CANTFREE, FAIL, "unable to decrement ref-counted page");
 
 done:
     FUNC_LEAVE_NOAPI(ret_value);
@@ -1225,6 +1236,31 @@ done:
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5D_istore_page_free
+ *
+ * Purpose:	Free a B-tree node
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Quincey Koziol
+ *              Thursday, July  8, 2004
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5D_istore_page_free (void *page)
+{
+    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5D_istore_page_free)
+
+    H5FL_BLK_FREE(chunk_page,page);
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* end H5D_istore_page_free() */
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5D_istore_prune
  *
  * Purpose:	Prune the cache by preempting some things until the cache has