[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, 129 insertions, 0 deletions

diff --git a/src/H5RC.c b/src/H5RC.c
new file mode 100644
index 0000000..8ab1818
--- /dev/null
+++ b/src/H5RC.c
@@ -0,0 +1,129 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by the Board of Trustees of the University of Illinois.         *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5.  The full HDF5 copyright notice, including     *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the files COPYING and Copyright.html.  COPYING can be found at the root   *
+ * of the source code distribution tree; Copyright.html can be found at the  *
+ * root level of an installed copy of the electronic HDF5 document set and   *
+ * is linked from the top-level documents page.  It can also be found at     *
+ * http://hdf.ncsa.uiuc.edu/HDF5/doc/Copyright.html.  If you do not have     *
+ * access to either file, you may request a copy from hdfhelp@ncsa.uiuc.edu. *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+/*
+ * Reference counting buffer algorithms.
+ *
+ * These are used for various internal buffers which are shared.
+ *
+ */
+
+/* Pablo information */
+/* (Put before include files to avoid problems with inline functions) */
+#define PABLO_MASK	H5RC_mask
+
+#include "H5Eprivate.h"		/* Error handling		  	*/
+#include "H5FLprivate.h"	/* Free lists                           */
+#include "H5RCprivate.h"        /* Reference-counted buffers            */
+
+/* Private typedefs & structs */
+
+/* Declare a free list to manage the H5RC_t struct */
+H5FL_DEFINE_STATIC(H5RC_t);
+
+
+/*--------------------------------------------------------------------------
+ NAME
+    H5RC_create
+ PURPOSE
+    Create a reference counted object
+ USAGE
+    H5RC_t *H5RC_create(o,free)
+        const void *o;          IN: Object to initialize ref-counted object with
+        H5RC_free_func_t free;  IN: Function to call when ref-count drop to zero
+
+ RETURNS
+    Returns a pointer to a new ref-counted object on success, NULL on failure.
+ DESCRIPTION
+    Create a reference counted object.  The object is not duplicated, it is
+    assumed to be owned by the reference counted object now and will be freed
+    with the 'free' function when the reference count drops to zero.
+ GLOBAL VARIABLES
+ COMMENTS, BUGS, ASSUMPTIONS
+ EXAMPLES
+ REVISION LOG
+--------------------------------------------------------------------------*/
+H5RC_t *
+H5RC_create(void *o, H5RC_free_func_t free_func)
+{
+    H5RC_t *ret_value=NULL;   /* Return value */
+
+    FUNC_ENTER_NOAPI(H5RC_create,NULL);
+
+    /* Sanity check */
+    HDassert(o);
+    HDassert(free_func);
+
+    /* Allocate ref-counted string structure */
+    if((ret_value=H5FL_MALLOC(H5RC_t))==NULL)
+        HGOTO_ERROR(H5E_RS,H5E_NOSPACE,NULL,"memory allocation failed");
+
+    /* Set the internal fields */
+    ret_value->o=o;
+    ret_value->n=1;
+    ret_value->free_func=free_func;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value);
+} /* end H5RC_create() */
+
+
+/*--------------------------------------------------------------------------
+ NAME
+    H5RC_decr
+ PURPOSE
+    Decrement the reference count for a ref-counted object
+ USAGE
+    herr_t H5RC_decr(rc)
+        H5RC_t *rc;             IN: Ref-counted object to decrement count for
+
+ RETURNS
+    SUCCEED/FAIL
+ DESCRIPTION
+    Decrements the reference count for a ref-counted object, calling the
+    object's free function if ref-count drops to zero.
+ GLOBAL VARIABLES
+ COMMENTS, BUGS, ASSUMPTIONS
+ EXAMPLES
+ REVISION LOG
+--------------------------------------------------------------------------*/
+herr_t
+H5RC_decr(H5RC_t *rc)
+{
+    herr_t ret_value=SUCCEED;   /* Return value */
+
+    FUNC_ENTER_NOAPI(H5RC_decr,FAIL);
+
+    /* Sanity check */
+    HDassert(rc);
+    HDassert(rc->o);
+    HDassert(rc->n>0);
+    HDassert(rc->free_func);
+
+    /* Decrement reference count */
+    rc->n--;
+
+    /* Check if we should delete this object now */
+    if(rc->n==0) {
+        if((rc->free_func)(rc->o)<0) {
+            H5FL_FREE(H5RC_t,rc);
+            HGOTO_ERROR(H5E_RS,H5E_CANTFREE,FAIL,"memory release failed");
+        } /* end if */
+        H5FL_FREE(H5RC_t,rc);
+    } /* end if */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value);
+} /* end H5RC_decr() */
+