[svn-r17002] Description:

    Rename H5O_protect/H5O_unprotect to be H5O_pin/H5O_unpin, since that's what
that are actually doing.

    Add counter of the number of times the object header is pinned, to allow
H5O_pin/H5O_unpin to be called reentrantly.

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/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 10.5.7 (amazon) in debug mode
    Mac OS X/32 10.5.7 (amazon) w/C++ & FORTRAN, w/threadsafe,
        in production mode

5 files changed, 67 insertions, 42 deletions

diff --git a/src/H5Dint.c b/src/H5Dint.c
index 00bc347..36ad640 100644
--- a/src/H5Dint.c
+++ b/src/H5Dint.c
@@ -844,8 +844,8 @@ H5D_update_oh_info(H5F_t *file, hid_t dxpl_id, H5D_t *dset)
     HDassert(file == dset->oloc.file);
 
     /* Get a pointer to the object header itself */
-    if((oh = H5O_protect(oloc, dxpl_id)) == NULL)
-        HGOTO_ERROR(H5E_DATASET, H5E_CANTPROTECT, FAIL, "unable to protect dataset object header")
+    if(NULL == (oh = H5O_pin(oloc, dxpl_id)))
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTPIN, FAIL, "unable to pin dataset object header")
 
     /* Write new fill value message */
     if(H5O_msg_append_oh(file, dxpl_id, oh, H5O_FILL_NEW_ID, H5O_MSG_FLAG_CONSTANT, 0, fill_prop) < 0)
@@ -981,8 +981,8 @@ H5D_update_oh_info(H5F_t *file, hid_t dxpl_id, H5D_t *dset)
 done:
     /* Release pointer to object header itself */
     if(oloc != NULL && oh != NULL)
-        if(H5O_unprotect(oloc, oh) < 0)
-            HDONE_ERROR(H5E_DATASET, H5E_CANTUNPROTECT, FAIL, "unable to unprotect dataset object header")
+        if(H5O_unpin(oloc, oh) < 0)
+            HDONE_ERROR(H5E_DATASET, H5E_CANTUNPIN, FAIL, "unable to unpin dataset object header")
 
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5D_update_oh_info() */
@@ -2410,8 +2410,8 @@ H5D_flush_real(H5D_t *dataset, hid_t dxpl_id, unsigned flags)
         unsigned update_flags = H5O_UPDATE_TIME;        /* Modification time flag */
 
         /* Get a pointer to the dataset's object header */
-        if((oh = H5O_protect(&dataset->oloc, dxpl_id)) == NULL)
-            HGOTO_ERROR(H5E_DATASET, H5E_CANTPROTECT, FAIL, "unable to protect dataset object header")
+        if(NULL == (oh = H5O_pin(&dataset->oloc, dxpl_id)))
+            HGOTO_ERROR(H5E_DATASET, H5E_CANTPIN, FAIL, "unable to pin dataset object header")
 
         /* Update the layout on disk, if it's been changed */
         if(dataset->shared->layout_dirty) {
@@ -2479,8 +2479,8 @@ H5D_flush_real(H5D_t *dataset, hid_t dxpl_id, unsigned flags)
 done:
     /* Release pointer to object header */
     if(oh != NULL)
-        if(H5O_unprotect(&(dataset->oloc), oh) < 0)
-            HDONE_ERROR(H5E_DATASET, H5E_CANTUNPROTECT, FAIL, "unable to unprotect dataset object header")
+        if(H5O_unpin(&(dataset->oloc), oh) < 0)
+            HDONE_ERROR(H5E_DATASET, H5E_CANTUNPIN, FAIL, "unable to unpin dataset object header")
 
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5D_flush_real() */
diff --git a/src/H5Gobj.c b/src/H5Gobj.c
index 08a9268..a11dc13 100644
--- a/src/H5Gobj.c
+++ b/src/H5Gobj.c
@@ -806,8 +806,8 @@ H5G_obj_remove_update_linfo(H5O_loc_t *oloc, H5O_linfo_t *linfo, hid_t dxpl_id)
                     HGOTO_ERROR(H5E_SYM, H5E_CANTNEXT, FAIL, "error iterating over links")
 
                 /* Get a pointer to the object header itself */
-                if((oh = H5O_protect(oloc, dxpl_id)) == NULL)
-                    HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to protect dataset object header")
+                if(NULL == (oh = H5O_pin(oloc, dxpl_id)))
+                    HGOTO_ERROR(H5E_SYM, H5E_CANTPIN, FAIL, "unable to pin group object header")
 
                 /* Inspect links in table for ones that can't be converted back
                  * into link message form (currently only links which can't fit
@@ -825,8 +825,8 @@ H5G_obj_remove_update_linfo(H5O_loc_t *oloc, H5O_linfo_t *linfo, hid_t dxpl_id)
                     for(u = 0; u < linfo->nlinks; u++)
                         if(H5O_msg_append_oh(oloc->file, dxpl_id, oh, H5O_LINK_ID, 0, H5O_UPDATE_TIME, &(ltable.lnks[u])) < 0) {
                             /* Release object header */
-                            if(H5O_unprotect(oloc, oh) < 0)
-                                HDONE_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to unprotect dataset object header")
+                            if(H5O_unpin(oloc, oh) < 0)
+                                HDONE_ERROR(H5E_SYM, H5E_CANTUNPIN, FAIL, "unable to unpin group object header")
 
                             HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "can't create message")
                         } /* end if */
@@ -837,8 +837,8 @@ H5G_obj_remove_update_linfo(H5O_loc_t *oloc, H5O_linfo_t *linfo, hid_t dxpl_id)
                 } /* end if */
 
                 /* Release object header */
-                if(H5O_unprotect(oloc, oh) < 0)
-                    HDONE_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to unprotect dataset object header")
+                if(H5O_unpin(oloc, oh) < 0)
+                    HGOTO_ERROR(H5E_SYM, H5E_CANTUNPIN, FAIL, "unable to unpin group object header")
 
                 /* Free link table information */
                 if(H5G_link_release_table(&ltable) < 0)
diff --git a/src/H5O.c b/src/H5O.c
index 8b684d4..2017e1c 100644
--- a/src/H5O.c
+++ b/src/H5O.c
@@ -439,8 +439,11 @@ H5Olink(hid_t obj_id, hid_t new_loc_id, const char *new_name, hid_t lcpl_id,
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
     if(!new_name || !*new_name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name specified")
+/* Avoid compiler warning on 32-bit machines */
+#if H5_SIZEOF_SIZE_T > H5_SIZEOF_INT32_T
     if(HDstrlen(new_name) > H5L_MAX_LINK_NAME_LEN)
         HGOTO_ERROR(H5E_ARGS, H5E_BADRANGE, FAIL, "name too long")
+#endif /* H5_SIZEOF_SIZE_T > H5_SIZEOF_INT32_T */
     if(lcpl_id != H5P_DEFAULT && (TRUE != H5P_isa_class(lcpl_id, H5P_LINK_CREATE)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a link creation property list")
 
@@ -1128,9 +1131,13 @@ H5O_create(H5F_t *f, hid_t dxpl_id, size_t size_hint, hid_t ocpl_id,
             oh->flags |= H5O_HDR_ATTR_STORE_PHASE_CHANGE;
 
         /* Determine correct value for chunk #0 size bits */
+/* Avoid compiler warning on 32-bit machines */
+#if H5_SIZEOF_SIZE_T > H5_SIZEOF_INT32_T
         if(size_hint > 4294967295)
             oh->flags |= H5O_HDR_CHUNK0_8;
-        else if(size_hint > 65535)
+        else 
+#endif /* H5_SIZEOF_SIZE_T > H5_SIZEOF_INT32_T */
+        if(size_hint > 65535)
             oh->flags |= H5O_HDR_CHUNK0_4;
         else if(size_hint > 255)
             oh->flags |= H5O_HDR_CHUNK0_2;
@@ -1545,15 +1552,14 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5O_protect
+ * Function:	H5O_pin
  *
- * Purpose:	Wrapper around H5AC_protect for use during a H5O_protect->
- *              H5O_msg_append->...->H5O_msg_append->H5O_unprotect sequence of calls
- *              during an object's creation.
+ * Purpose:	Pin an object header down for use during a sequence of message
+ *              operations, which prevents the object header from being
+ *              evicted from the cache.
  *
  * Return:	Success:	Pointer to the object header structure for the
  *                              object.
- *
  *		Failure:	NULL
  *
  * Programmer:	Quincey Koziol
@@ -1563,11 +1569,12 @@ done:
  *-------------------------------------------------------------------------
  */
 H5O_t *
-H5O_protect(H5O_loc_t *loc, hid_t dxpl_id)
+H5O_pin(H5O_loc_t *loc, hid_t dxpl_id)
 {
-    H5O_t	       *ret_value;      /* Return value */
+    H5O_t       *oh = NULL;      /* Object header */
+    H5O_t       *ret_value;      /* Return value */
 
-    FUNC_ENTER_NOAPI(H5O_protect, NULL)
+    FUNC_ENTER_NOAPI(H5O_pin, NULL)
 
     /* check args */
     HDassert(loc);
@@ -1579,31 +1586,38 @@ H5O_protect(H5O_loc_t *loc, hid_t dxpl_id)
 	HGOTO_ERROR(H5E_OHDR, H5E_WRITEERROR, NULL, "no write intent on file")
 
     /* Lock the object header into the cache */
-    if(NULL == (ret_value = (H5O_t *)H5AC_protect(loc->file, dxpl_id, H5AC_OHDR, loc->addr, NULL, NULL, H5AC_WRITE)))
+    if(NULL == (oh = (H5O_t *)H5AC_protect(loc->file, dxpl_id, H5AC_OHDR, loc->addr, NULL, NULL, H5AC_WRITE)))
 	HGOTO_ERROR(H5E_OHDR, H5E_CANTPROTECT, NULL, "unable to load object header")
 
-    /* Mark object header as un-evictable */
-    if(H5AC_pin_protected_entry(loc->file, ret_value) < 0)
-        HGOTO_ERROR(H5E_OHDR, H5E_CANTPIN, NULL, "unable to pin object header")
+    /* Check if the object header needs to be pinned */
+    if(0 == oh->npins) {
+        /* Mark object header as un-evictable */
+        if(H5AC_pin_protected_entry(loc->file, oh) < 0)
+            HGOTO_ERROR(H5E_OHDR, H5E_CANTPIN, NULL, "unable to pin object header")
+    } /* end if */
+
+    /* Increment the pin count */
+    oh->npins++;
+
+    /* Set the return value */
+    ret_value = oh;
 
 done:
     /* Release the object header from the cache */
-    if(H5AC_unprotect(loc->file, dxpl_id, H5AC_OHDR, loc->addr, ret_value, H5AC__NO_FLAGS_SET) < 0)
+    if(oh && H5AC_unprotect(loc->file, dxpl_id, H5AC_OHDR, loc->addr, ret_value, H5AC__NO_FLAGS_SET) < 0)
         HDONE_ERROR(H5E_OHDR, H5E_CANTUNPROTECT, NULL, "unable to release object header")
 
     FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5O_protect() */
+} /* end H5O_pin() */
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5O_unprotect
+ * Function:	H5O_unpin
  *
- * Purpose:	Wrapper around H5AC_unprotect for use during a H5O_protect->
- *              H5O_msg_append->...->H5O_msg_append->H5O_unprotect sequence of calls
- *              during an object's creation.
+ * Purpose:	Unpin an object header, allowing it to be evicted from the
+ *              metadata cache.
  *
  * Return:	Success:	Non-negative
- *
  *		Failure:	Negative
  *
  * Programmer:	Quincey Koziol
@@ -1613,11 +1627,11 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5O_unprotect(H5O_loc_t *loc, H5O_t *oh)
+H5O_unpin(H5O_loc_t *loc, H5O_t *oh)
 {
     herr_t ret_value = SUCCEED;      /* Return value */
 
-    FUNC_ENTER_NOAPI(H5O_unprotect, FAIL)
+    FUNC_ENTER_NOAPI(H5O_unpin, FAIL)
 
     /* check args */
     HDassert(loc);
@@ -1625,13 +1639,19 @@ H5O_unprotect(H5O_loc_t *loc, H5O_t *oh)
     HDassert(H5F_addr_defined(loc->addr));
     HDassert(oh);
 
-    /* Mark object header as evictable again */
-    if(H5AC_unpin_entry(loc->file, oh) < 0)
-        HGOTO_ERROR(H5E_OHDR, H5E_CANTUNPIN, FAIL, "unable to unpin object header")
+    /* Check if this is the last unpin operation */
+    if(1 == oh->npins) {
+        /* Mark object header as evictable again */
+        if(H5AC_unpin_entry(loc->file, oh) < 0)
+            HGOTO_ERROR(H5E_OHDR, H5E_CANTUNPIN, FAIL, "unable to unpin object header")
+    } /* end if */
+
+    /* Decrement the pin count */
+    oh->npins--;
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5O_unprotect() */
+} /* end H5O_unpin() */
 
 
 /*-------------------------------------------------------------------------
diff --git a/src/H5Opkg.h b/src/H5Opkg.h
index 9981461..8569119 100644
--- a/src/H5Opkg.h
+++ b/src/H5Opkg.h
@@ -266,6 +266,11 @@ struct H5O_t {
     /* File-specific information (not stored) */
     size_t      sizeof_size;            /* Size of file sizes 		     */
     size_t      sizeof_addr;            /* Size of file addresses	     */
+
+    /* Misc. information (not stored) */
+    unsigned    npins;                  /* Number of times the header is pinned */
+
+    /* Debugging information (not stored) */
 #ifdef H5O_ENABLE_BAD_MESG_COUNT
     hbool_t     store_bad_mesg_count;   /* Flag to indicate that a bad message count should be stored */
                                         /* (This is to simulate a bug in earlier
diff --git a/src/H5Oprivate.h b/src/H5Oprivate.h
index 018bc77..bf416f4 100644
--- a/src/H5Oprivate.h
+++ b/src/H5Oprivate.h
@@ -578,8 +578,8 @@ H5_DLL herr_t H5O_open(H5O_loc_t *loc);
 H5_DLL herr_t H5O_close(H5O_loc_t *loc);
 H5_DLL int H5O_link(const H5O_loc_t *loc, int adjust, hid_t dxpl_id);
 H5_DLL int H5O_link_oh(H5F_t *f, int adjust, hid_t dxpl_id, H5O_t *oh, unsigned *oh_flags);
-H5_DLL H5O_t *H5O_protect(H5O_loc_t *loc, hid_t dxpl_id);
-H5_DLL herr_t H5O_unprotect(H5O_loc_t *loc, H5O_t *oh);
+H5_DLL H5O_t *H5O_pin(H5O_loc_t *loc, hid_t dxpl_id);
+H5_DLL herr_t H5O_unpin(H5O_loc_t *loc, H5O_t *oh);
 H5_DLL herr_t H5O_touch(H5O_loc_t *loc, hbool_t force, hid_t dxpl_id);
 H5_DLL herr_t H5O_touch_oh(H5F_t *f, hid_t dxpl_id, H5O_t *oh,
     hbool_t force);