[svn-r24311] change event queue to event stack (just variable names)

24 files changed, 407 insertions, 407 deletions

diff --git a/src/H5A.c b/src/H5A.c
index c3fc7f0..cf4bc4d 100644
--- a/src/H5A.c
+++ b/src/H5A.c
@@ -267,7 +267,7 @@ H5Acreate2(hid_t loc_id, const char *attr_name, hid_t type_id, hid_t space_id,
 
     /* Create the attribute through the VOL */
     if(NULL == (attr = H5VL_attr_create(obj, loc_params, vol_plugin, attr_name, acpl_id, aapl_id, 
-                                        H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)))
+                                        H5AC_dxpl_id, H5_EVENT_STACK_NULL)))
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to create attribute")
 
     /* Get an atom for the attribute */
@@ -276,7 +276,7 @@ H5Acreate2(hid_t loc_id, const char *attr_name, hid_t type_id, hid_t space_id,
 
 done:
     if (ret_value < 0 && attr)
-        if(H5VL_attr_close (attr, vol_plugin, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL) < 0)
+        if(H5VL_attr_close (attr, vol_plugin, H5AC_dxpl_id, H5_EVENT_STACK_NULL) < 0)
             HDONE_ERROR(H5E_ATTR, H5E_CLOSEERROR, FAIL, "unable to release attr")
     FUNC_LEAVE_API(ret_value)
 } /* H5Acreate2() */
@@ -365,7 +365,7 @@ H5Acreate_by_name(hid_t loc_id, const char *obj_name, const char *attr_name,
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
 
     /* Create the attribute through the VOL */
-    if(NULL == (attr = H5VL_attr_create(obj, loc_params, vol_plugin, attr_name, acpl_id, aapl_id, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)))
+    if(NULL == (attr = H5VL_attr_create(obj, loc_params, vol_plugin, attr_name, acpl_id, aapl_id, H5AC_dxpl_id, H5_EVENT_STACK_NULL)))
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to create attribute")
 
     /* Get an atom for the attribute */
@@ -374,7 +374,7 @@ H5Acreate_by_name(hid_t loc_id, const char *obj_name, const char *attr_name,
 
 done:
     if (ret_value < 0 && attr)
-        if(H5VL_attr_close (attr, vol_plugin, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL) < 0)
+        if(H5VL_attr_close (attr, vol_plugin, H5AC_dxpl_id, H5_EVENT_STACK_NULL) < 0)
             HDONE_ERROR(H5E_ATTR, H5E_CLOSEERROR, FAIL, "unable to release attr")
     FUNC_LEAVE_API(ret_value)
 } /* H5Acreate_by_name() */
@@ -429,7 +429,7 @@ H5Aopen(hid_t loc_id, const char *attr_name, hid_t aapl_id)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
 
     /* Create the attribute through the VOL */
-    if(NULL == (attr = H5VL_attr_open(obj, loc_params, vol_plugin, attr_name, aapl_id, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)))
+    if(NULL == (attr = H5VL_attr_open(obj, loc_params, vol_plugin, attr_name, aapl_id, H5AC_dxpl_id, H5_EVENT_STACK_NULL)))
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to open attribute")
 
     /* Get an atom for the attribute */
@@ -438,7 +438,7 @@ H5Aopen(hid_t loc_id, const char *attr_name, hid_t aapl_id)
 
 done:
     if (ret_value < 0 && attr)
-        if(H5VL_attr_close (attr, vol_plugin, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL) < 0)
+        if(H5VL_attr_close (attr, vol_plugin, H5AC_dxpl_id, H5_EVENT_STACK_NULL) < 0)
             HDONE_ERROR(H5E_ATTR, H5E_CLOSEERROR, FAIL, "unable to release attr")
     FUNC_LEAVE_API(ret_value)
 } /* H5Aopen() */
@@ -505,7 +505,7 @@ H5Aopen_by_name(hid_t loc_id, const char *obj_name, const char *attr_name,
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
 
     /* Create the attribute through the VOL */
-    if(NULL == (attr = H5VL_attr_open(obj, loc_params, vol_plugin, attr_name, aapl_id, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)))
+    if(NULL == (attr = H5VL_attr_open(obj, loc_params, vol_plugin, attr_name, aapl_id, H5AC_dxpl_id, H5_EVENT_STACK_NULL)))
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to open attribute")
 
     /* Get an atom for the attribute */
@@ -514,7 +514,7 @@ H5Aopen_by_name(hid_t loc_id, const char *obj_name, const char *attr_name,
 
 done:
     if (ret_value < 0 && attr)
-        if(H5VL_attr_close (attr, vol_plugin, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL) < 0)
+        if(H5VL_attr_close (attr, vol_plugin, H5AC_dxpl_id, H5_EVENT_STACK_NULL) < 0)
             HDONE_ERROR(H5E_ATTR, H5E_CLOSEERROR, FAIL, "unable to release attr")
     FUNC_LEAVE_API(ret_value)
 } /* H5Aopen_by_name() */
@@ -590,7 +590,7 @@ H5Aopen_by_idx(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
 
     /* Create the attribute through the VOL */
-    if(NULL == (attr = H5VL_attr_open(obj, loc_params, vol_plugin, NULL, aapl_id, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)))
+    if(NULL == (attr = H5VL_attr_open(obj, loc_params, vol_plugin, NULL, aapl_id, H5AC_dxpl_id, H5_EVENT_STACK_NULL)))
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to open attribute")
 
     /* Get an atom for the attribute */
@@ -599,7 +599,7 @@ H5Aopen_by_idx(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
 
 done:
     if (ret_value < 0 && attr)
-        if(H5VL_attr_close (attr, vol_plugin, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL) < 0)
+        if(H5VL_attr_close (attr, vol_plugin, H5AC_dxpl_id, H5_EVENT_STACK_NULL) < 0)
             HDONE_ERROR(H5E_ATTR, H5E_CLOSEERROR, FAIL, "unable to release attr")
     FUNC_LEAVE_API(ret_value)
 } /* H5Aopen_by_idx() */
@@ -643,7 +643,7 @@ H5Awrite(hid_t attr_id, hid_t dtype_id, const void *buf)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid attribute identifier")
 
     /* write the data through the VOL */
-    if((ret_value = H5VL_attr_write(attr, vol_plugin, dtype_id, buf, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+    if((ret_value = H5VL_attr_write(attr, vol_plugin, dtype_id, buf, H5AC_dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_ATTR, H5E_READERROR, FAIL, "can't read data")
 
 done:
@@ -689,7 +689,7 @@ H5Aread(hid_t attr_id, hid_t dtype_id, void *buf)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid attribute identifier")
 
     /* Read the data through the VOL */
-    if((ret_value = H5VL_attr_read(attr, vol_plugin, dtype_id, buf, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+    if((ret_value = H5VL_attr_read(attr, vol_plugin, dtype_id, buf, H5AC_dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_ATTR, H5E_READERROR, FAIL, "can't read data")
 
 done:
@@ -731,7 +731,7 @@ H5Aget_space(hid_t attr_id)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid attribute identifier")
 
     /* get the dataspace through the VOL */
-    if(H5VL_attr_get(attr, vol_plugin, H5VL_ATTR_GET_SPACE, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, &ret_value) < 0)
+    if(H5VL_attr_get(attr, vol_plugin, H5VL_ATTR_GET_SPACE, H5AC_dxpl_id, H5_EVENT_STACK_NULL, &ret_value) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get data space")
 
 done:
@@ -773,7 +773,7 @@ H5Aget_type(hid_t attr_id)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid attribute identifier")
 
     /* get the datatype through the VOL */
-    if(H5VL_attr_get(attr, vol_plugin, H5VL_ATTR_GET_TYPE, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, &ret_value) < 0)
+    if(H5VL_attr_get(attr, vol_plugin, H5VL_ATTR_GET_TYPE, H5AC_dxpl_id, H5_EVENT_STACK_NULL, &ret_value) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get type")
 
 done:
@@ -820,7 +820,7 @@ H5Aget_create_plist(hid_t attr_id)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid attribute identifier")
 
     /* get the acpl through the VOL */
-    if(H5VL_attr_get(attr, vol_plugin, H5VL_ATTR_GET_ACPL, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, &ret_value) < 0)
+    if(H5VL_attr_get(attr, vol_plugin, H5VL_ATTR_GET_ACPL, H5AC_dxpl_id, H5_EVENT_STACK_NULL, &ret_value) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get acpl")
 
 done:
@@ -875,7 +875,7 @@ H5Aget_name(hid_t attr_id, size_t buf_size, char *buf)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid attribute identifier")
 
     /* get the name through the VOL */
-    if(H5VL_attr_get(attr, vol_plugin, H5VL_ATTR_GET_NAME, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, loc_params, buf_size, buf, &ret_value) < 0)
+    if(H5VL_attr_get(attr, vol_plugin, H5VL_ATTR_GET_NAME, H5AC_dxpl_id, H5_EVENT_STACK_NULL, loc_params, buf_size, buf, &ret_value) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get name")
 
 done:
@@ -945,17 +945,17 @@ H5Aget_name_by_idx(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
     loc_params.obj_type = H5I_get_type(loc_id);
 
     /* get the name through the VOL */
-    if(H5VL_attr_get(obj, vol_plugin, H5VL_ATTR_GET_NAME, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, 
+    if(H5VL_attr_get(obj, vol_plugin, H5VL_ATTR_GET_NAME, H5AC_dxpl_id, H5_EVENT_STACK_NULL, 
                      loc_params, size, name, &ret_value) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get name")
 
 #if 0
-    if(H5VL_object_misc(loc_id, H5VL_ATTR_OPEN_BY_IDX, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, &attr_id, 
+    if(H5VL_object_misc(loc_id, H5VL_ATTR_OPEN_BY_IDX, H5AC_dxpl_id, H5_EVENT_STACK_NULL, &attr_id, 
                          obj_name, idx_type, order, n, H5P_DEFAULT, lapl_id) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTINIT, FAIL, "unable to open attribute")
 
     /* get the name through the VOL */
-    if(H5VL_attr_get(attr_id, H5VL_ATTR_GET_NAME, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, &ret_value, size, name) < 0)
+    if(H5VL_attr_get(attr_id, H5VL_ATTR_GET_NAME, H5AC_dxpl_id, H5_EVENT_STACK_NULL, &ret_value, size, name) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get name")
 #endif
 
@@ -999,7 +999,7 @@ H5Aget_storage_size(hid_t attr_id)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, 0, "invalid attribute identifier")
 
     /* get the storage size through the VOL */
-    if(H5VL_attr_get(attr, vol_plugin, H5VL_ATTR_GET_STORAGE_SIZE, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, &ret_value) < 0)
+    if(H5VL_attr_get(attr, vol_plugin, H5VL_ATTR_GET_STORAGE_SIZE, H5AC_dxpl_id, H5_EVENT_STACK_NULL, &ret_value) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, 0, "unable to get acpl")
 
 done:
@@ -1042,7 +1042,7 @@ H5Aget_info(hid_t attr_id, H5A_info_t *ainfo)
     loc_params.obj_type = H5I_get_type(attr_id);
 
     /* get the attribute info through the VOL */
-    if(H5VL_attr_get(attr, vol_plugin, H5VL_ATTR_GET_INFO, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, loc_params, ainfo) < 0)
+    if(H5VL_attr_get(attr, vol_plugin, H5VL_ATTR_GET_INFO, H5AC_dxpl_id, H5_EVENT_STACK_NULL, loc_params, ainfo) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get attribute info")
 
 done:
@@ -1103,20 +1103,20 @@ H5Aget_info_by_name(hid_t loc_id, const char *obj_name, const char *attr_name,
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid object identifier")
 
     /* get the attribute info through the VOL */
-    if(H5VL_attr_get(obj, vol_plugin, H5VL_ATTR_GET_INFO, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, loc_params, ainfo, attr_name) < 0)
+    if(H5VL_attr_get(obj, vol_plugin, H5VL_ATTR_GET_INFO, H5AC_dxpl_id, H5_EVENT_STACK_NULL, loc_params, ainfo, attr_name) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get attribute info")
 
 #if 0
     /* Open the attribute through the VOL */
-    if((attr_id = H5VL_attr_open(loc_id, loc_params, attr_name, H5P_DEFAULT, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+    if((attr_id = H5VL_attr_open(loc_id, loc_params, attr_name, H5P_DEFAULT, H5AC_dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_ATTR, H5E_CANTINIT, FAIL, "unable to open attribute")
 
     /* get the attribute info through the VOL */
-    if(H5VL_attr_get(attr_id, H5VL_ATTR_GET_INFO, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, ainfo) < 0)
+    if(H5VL_attr_get(attr_id, H5VL_ATTR_GET_INFO, H5AC_dxpl_id, H5_EVENT_STACK_NULL, ainfo) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get attribute info")
 
     /* release resources */
-    if(attr_id > 0 && H5VL_attr_close(attr_id, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL) < 0)
+    if(attr_id > 0 && H5VL_attr_close(attr_id, H5AC_dxpl_id, H5_EVENT_STACK_NULL) < 0)
         HDONE_ERROR(H5E_ATTR, H5E_CANTFREE, FAIL, "can't close attribute")
 
 #endif
@@ -1186,7 +1186,7 @@ H5Aget_info_by_idx(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid object identifier")
 
     /* get the attribute info through the VOL */
-    if(H5VL_attr_get(obj, vol_plugin, H5VL_ATTR_GET_INFO, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, 
+    if(H5VL_attr_get(obj, vol_plugin, H5VL_ATTR_GET_INFO, H5AC_dxpl_id, H5_EVENT_STACK_NULL, 
                      loc_params, ainfo) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get attribute info")
 
@@ -1200,16 +1200,16 @@ H5Aget_info_by_idx(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
 	HGOTO_ERROR(H5E_ATTR, H5E_CANTGET, FAIL, "unable to get attribute info")
 
     /* open the attribute through the VOL */
-    if(H5VL_object_misc(loc_id, H5VL_ATTR_OPEN_BY_IDX, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, &attr_id, 
+    if(H5VL_object_misc(loc_id, H5VL_ATTR_OPEN_BY_IDX, H5AC_dxpl_id, H5_EVENT_STACK_NULL, &attr_id, 
                          obj_name, idx_type, order, n, H5P_DEFAULT, lapl_id) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTINIT, FAIL, "unable to open attribute")
 
     /* get the attribute info through the VOL */
-    if(H5VL_attr_get(attr_id, H5VL_ATTR_GET_INFO, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, ainfo) < 0)
+    if(H5VL_attr_get(attr_id, H5VL_ATTR_GET_INFO, H5AC_dxpl_id, H5_EVENT_STACK_NULL, ainfo) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get attribute info")
 
     /* Release resources */
-    if(attr_id && H5VL_attr_close(attr_id, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL) < 0)
+    if(attr_id && H5VL_attr_close(attr_id, H5AC_dxpl_id, H5_EVENT_STACK_NULL) < 0)
         HDONE_ERROR(H5E_ATTR, H5E_CANTFREE, FAIL, "can't close attribute")
 #endif
 
@@ -1262,7 +1262,7 @@ H5Arename(hid_t loc_id, const char *old_name, const char *new_name)
             HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
 
         /* rename the attribute info through the VOL */
-        if(H5VL_object_misc(obj, loc_params, vol_plugin, H5VL_ATTR_RENAME, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, 
+        if(H5VL_object_misc(obj, loc_params, vol_plugin, H5VL_ATTR_RENAME, H5AC_dxpl_id, H5_EVENT_STACK_NULL, 
                             old_name, new_name) < 0)
             HGOTO_ERROR(H5E_ATTR, H5E_CANTRENAME, FAIL, "can't rename attribute")
     }
@@ -1328,7 +1328,7 @@ H5Arename_by_name(hid_t loc_id, const char *obj_name, const char *old_attr_name,
             HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
 
         /* rename the attribute info through the VOL */
-        if(H5VL_object_misc(obj, loc_params, vol_plugin, H5VL_ATTR_RENAME, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, 
+        if(H5VL_object_misc(obj, loc_params, vol_plugin, H5VL_ATTR_RENAME, H5AC_dxpl_id, H5_EVENT_STACK_NULL, 
                             old_attr_name, new_attr_name) < 0)
             HGOTO_ERROR(H5E_ATTR, H5E_CANTRENAME, FAIL, "can't rename attribute")
     } /* end if */
@@ -1411,7 +1411,7 @@ H5Aiterate2(hid_t loc_id, H5_index_t idx_type, H5_iter_order_t order,
 
     /* iterate over the links through the VOL */
     if((ret_value = H5VL_attr_iterate(obj, loc_params, vol_plugin, idx_type, order, idx,
-                                      op, op_data, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+                                      op, op_data, H5AC_dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_BADITER, FAIL, "link iteration failed")
 
 done:
@@ -1505,7 +1505,7 @@ H5Aiterate_by_name(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
 
     /* iterate over the links through the VOL */
     if((ret_value = H5VL_attr_iterate(obj, loc_params, vol_plugin, idx_type, order, idx,
-                                      op, op_data, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+                                      op, op_data, H5AC_dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_BADITER, FAIL, "attribute iteration failed")
 
 done:
@@ -1555,7 +1555,7 @@ H5Adelete(hid_t loc_id, const char *name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid object identifier")
 
     /* Open the attribute through the VOL */
-    if(H5VL_attr_remove(obj, loc_params, vol_plugin, name, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL) < 0)
+    if(H5VL_attr_remove(obj, loc_params, vol_plugin, name, H5AC_dxpl_id, H5_EVENT_STACK_NULL) < 0)
 	HGOTO_ERROR(H5E_ATTR, H5E_CANTDELETE, FAIL, "unable to delete attribute")
 
 done:
@@ -1617,7 +1617,7 @@ H5Adelete_by_name(hid_t loc_id, const char *obj_name, const char *attr_name,
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid object identifier")
 
     /* Open the attribute through the VOL */
-    if(H5VL_attr_remove(obj, loc_params, vol_plugin, attr_name, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL) < 0)
+    if(H5VL_attr_remove(obj, loc_params, vol_plugin, attr_name, H5AC_dxpl_id, H5_EVENT_STACK_NULL) < 0)
 	HGOTO_ERROR(H5E_ATTR, H5E_CANTDELETE, FAIL, "unable to delete attribute")
 
 done:
@@ -1692,7 +1692,7 @@ H5Adelete_by_idx(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid object identifier")
 
     /* Open the attribute through the VOL */
-    if(H5VL_attr_remove(obj, loc_params, vol_plugin, NULL, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL) < 0)
+    if(H5VL_attr_remove(obj, loc_params, vol_plugin, NULL, H5AC_dxpl_id, H5_EVENT_STACK_NULL) < 0)
 	HGOTO_ERROR(H5E_ATTR, H5E_CANTDELETE, FAIL, "unable to delete attribute")
 
 #if 0
@@ -1701,7 +1701,7 @@ H5Adelete_by_idx(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
     loc_params.loc_data.loc_by_name.plist_id = lapl_id;
 
     /* get the attribute info through the VOL */
-    if(H5VL_object_misc(loc_id, H5VL_ATTR_DELETE_BY_IDX, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, loc_params, 
+    if(H5VL_object_misc(loc_id, H5VL_ATTR_DELETE_BY_IDX, H5AC_dxpl_id, H5_EVENT_STACK_NULL, loc_params, 
                         idx_type, order, n) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get attribute info")
 #endif
@@ -1789,7 +1789,7 @@ H5Aexists(hid_t obj_id, const char *attr_name)
     loc_params.obj_type = H5I_get_type(obj_id);
 
     /* get the attribute info through the VOL */
-    if(H5VL_attr_get(obj, vol_plugin, H5VL_ATTR_EXISTS, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, loc_params, attr_name, &ret_value) < 0)
+    if(H5VL_attr_get(obj, vol_plugin, H5VL_ATTR_EXISTS, H5AC_dxpl_id, H5_EVENT_STACK_NULL, loc_params, attr_name, &ret_value) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get attribute info")
 
 done:
@@ -1848,7 +1848,7 @@ H5Aexists_by_name(hid_t loc_id, const char *obj_name, const char *attr_name,
     loc_params.obj_type = H5I_get_type(loc_id);
 
     /* get the attribute info through the VOL */
-    if(H5VL_attr_get(obj, vol_plugin, H5VL_ATTR_EXISTS, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, loc_params, attr_name, &ret_value) < 0)
+    if(H5VL_attr_get(obj, vol_plugin, H5VL_ATTR_EXISTS, H5AC_dxpl_id, H5_EVENT_STACK_NULL, loc_params, attr_name, &ret_value) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get attribute info")
 
 done:
@@ -1878,7 +1878,7 @@ H5A_close_attr(void *attr, H5VL_t *vol_plugin)
     FUNC_ENTER_NOAPI_NOINIT
 
     /* Close the attr through the VOL*/
-    if((ret_value = H5VL_attr_close(attr, vol_plugin, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+    if((ret_value = H5VL_attr_close(attr, vol_plugin, H5AC_dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_ATTR, H5E_CLOSEERROR, FAIL, "unable to close attribute")
 
 done:
diff --git a/src/H5Adeprec.c b/src/H5Adeprec.c
index 248b969..e36ca69 100644
--- a/src/H5Adeprec.c
+++ b/src/H5Adeprec.c
@@ -181,7 +181,7 @@ H5Acreate1(hid_t loc_id, const char *name, hid_t type_id, hid_t space_id,
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
 
     /* Create the attribute through the VOL */
-    if(NULL == (attr = H5VL_attr_create(obj, loc_params, vol_plugin, name, plist_id, H5P_DEFAULT, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)))
+    if(NULL == (attr = H5VL_attr_create(obj, loc_params, vol_plugin, name, plist_id, H5P_DEFAULT, H5AC_dxpl_id, H5_EVENT_STACK_NULL)))
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to create attribute")
 
     /* Get an atom for the attribute */
@@ -190,7 +190,7 @@ H5Acreate1(hid_t loc_id, const char *name, hid_t type_id, hid_t space_id,
 
 done:
     if (ret_value < 0 && attr)
-        if(H5VL_attr_close (attr, vol_plugin, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL) < 0)
+        if(H5VL_attr_close (attr, vol_plugin, H5AC_dxpl_id, H5_EVENT_STACK_NULL) < 0)
             HDONE_ERROR(H5E_DATASET, H5E_CLOSEERROR, FAIL, "unable to release dataset")
     FUNC_LEAVE_API(ret_value)
 } /* H5Acreate1() */
@@ -248,7 +248,7 @@ H5Aopen_name(hid_t loc_id, const char *name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
 
     /* Create the attribute through the VOL */
-    if(NULL == (attr = H5VL_attr_open(obj, loc_params, vol_plugin, name, H5P_DEFAULT, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)))
+    if(NULL == (attr = H5VL_attr_open(obj, loc_params, vol_plugin, name, H5P_DEFAULT, H5AC_dxpl_id, H5_EVENT_STACK_NULL)))
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to open attribute")
 
     /* Get an atom for the attribute */
@@ -257,7 +257,7 @@ H5Aopen_name(hid_t loc_id, const char *name)
 
 done:
     if (ret_value < 0 && attr)
-        if(H5VL_attr_close (attr, vol_plugin, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL) < 0)
+        if(H5VL_attr_close (attr, vol_plugin, H5AC_dxpl_id, H5_EVENT_STACK_NULL) < 0)
             HDONE_ERROR(H5E_DATASET, H5E_CLOSEERROR, FAIL, "unable to release dataset")
     FUNC_LEAVE_API(ret_value)
 } /* H5Aopen_name() */
@@ -317,7 +317,7 @@ H5Aopen_idx(hid_t loc_id, unsigned idx)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
 
     /* Create the attribute through the VOL */
-    if(NULL == (attr = H5VL_attr_open(obj, loc_params, vol_plugin, NULL, H5P_DEFAULT, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)))
+    if(NULL == (attr = H5VL_attr_open(obj, loc_params, vol_plugin, NULL, H5P_DEFAULT, H5AC_dxpl_id, H5_EVENT_STACK_NULL)))
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to open attribute")
 
     /* Get an atom for the attribute */
@@ -326,7 +326,7 @@ H5Aopen_idx(hid_t loc_id, unsigned idx)
 
 done:
     if (ret_value < 0 && attr)
-        if(H5VL_attr_close (attr, vol_plugin, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL) < 0)
+        if(H5VL_attr_close (attr, vol_plugin, H5AC_dxpl_id, H5_EVENT_STACK_NULL) < 0)
             HDONE_ERROR(H5E_DATASET, H5E_CLOSEERROR, FAIL, "unable to release dataset")
     FUNC_LEAVE_API(ret_value)
 } /* H5Aopen_idx() */
@@ -374,7 +374,7 @@ H5Aget_num_attrs(hid_t loc_id)
 
     /* Get the group info through the VOL using the location token */
     if(H5VL_object_get(obj, loc_params, vol_plugin, H5VL_OBJECT_GET_INFO, 
-                       H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, &oinfo) < 0)
+                       H5AC_dxpl_id, H5_EVENT_STACK_NULL, &oinfo) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get group info")
 
     ret_value = oinfo.num_attrs;
diff --git a/src/H5D.c b/src/H5D.c
index 2f4341b..02b6016 100644
--- a/src/H5D.c
+++ b/src/H5D.c
@@ -195,7 +195,7 @@ H5Dcreate2(hid_t loc_id, const char *name, hid_t type_id, hid_t space_id,
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
 
     /* Create the dataset through the VOL */
-    if(NULL == (dset = H5VL_dataset_create(obj, loc_params, vol_plugin, name, dcpl_id, dapl_id, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)))
+    if(NULL == (dset = H5VL_dataset_create(obj, loc_params, vol_plugin, name, dcpl_id, dapl_id, H5AC_dxpl_id, H5_EVENT_STACK_NULL)))
 	HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to create dataset")
 
     /* Get an atom for the dataset */
@@ -204,7 +204,7 @@ H5Dcreate2(hid_t loc_id, const char *name, hid_t type_id, hid_t space_id,
 
 done:
     if (ret_value < 0 && dset)
-        if(H5VL_dataset_close (dset, vol_plugin, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL) < 0)
+        if(H5VL_dataset_close (dset, vol_plugin, H5AC_dxpl_id, H5_EVENT_STACK_NULL) < 0)
             HDONE_ERROR(H5E_DATASET, H5E_CLOSEERROR, FAIL, "unable to release dataset")
     FUNC_LEAVE_API(ret_value)
 } /* end H5Dcreate2() */
@@ -295,7 +295,7 @@ H5Dcreate_anon(hid_t loc_id, hid_t type_id, hid_t space_id, hid_t dcpl_id,
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
 
     /* Create the dataset through the VOL */
-    if(NULL == (dset = H5VL_dataset_create(obj, loc_params, vol_plugin, NULL, dcpl_id, dapl_id, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)))
+    if(NULL == (dset = H5VL_dataset_create(obj, loc_params, vol_plugin, NULL, dcpl_id, dapl_id, H5AC_dxpl_id, H5_EVENT_STACK_NULL)))
 	HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to create dataset")
 
     /* Get an atom for the dataset */
@@ -304,7 +304,7 @@ H5Dcreate_anon(hid_t loc_id, hid_t type_id, hid_t space_id, hid_t dcpl_id,
 
 done:
     if (ret_value < 0 && dset)
-        if(H5VL_dataset_close (dset, vol_plugin, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL) < 0)
+        if(H5VL_dataset_close (dset, vol_plugin, H5AC_dxpl_id, H5_EVENT_STACK_NULL) < 0)
             HDONE_ERROR(H5E_DATASET, H5E_CLOSEERROR, FAIL, "unable to release dataset")
     FUNC_LEAVE_API(ret_value)
 } /* end H5Dcreate_anon() */
@@ -362,7 +362,7 @@ H5Dopen2(hid_t loc_id, const char *name, hid_t dapl_id)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
 
     /* Create the dataset through the VOL */
-    if(NULL == (dset = H5VL_dataset_open(obj, loc_params, vol_plugin, name, dapl_id, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)))
+    if(NULL == (dset = H5VL_dataset_open(obj, loc_params, vol_plugin, name, dapl_id, H5AC_dxpl_id, H5_EVENT_STACK_NULL)))
 	HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to create dataset")
 
     /* Get an atom for the dataset */
@@ -371,7 +371,7 @@ H5Dopen2(hid_t loc_id, const char *name, hid_t dapl_id)
 
 done:
     if (ret_value < 0 && dset)
-        if(H5VL_dataset_close (dset, vol_plugin, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL) < 0)
+        if(H5VL_dataset_close (dset, vol_plugin, H5AC_dxpl_id, H5_EVENT_STACK_NULL) < 0)
             HDONE_ERROR(H5E_DATASET, H5E_CLOSEERROR, FAIL, "unable to release dataset")
     FUNC_LEAVE_API(ret_value)
 } /* end H5Dopen2() */
@@ -416,7 +416,7 @@ H5Dclose(hid_t dset_id)
 
 #if 0
     /* Close the dataset through the VOL */
-    if((ret_value = H5VL_dataset_close(dset_id, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+    if((ret_value = H5VL_dataset_close(dset_id, H5AC_dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_DATASET, H5E_CANTRELEASE, FAIL, "unable to close dataset")
 #endif
 
@@ -460,7 +460,7 @@ H5Dget_space(hid_t dset_id)
 
     /* get the dataspace through the VOL */
     if(H5VL_dataset_get(dset, vol_plugin, H5VL_DATASET_GET_SPACE, H5AC_dxpl_id, 
-			H5_EVENT_QUEUE_NULL, &ret_value) < 0)
+			H5_EVENT_STACK_NULL, &ret_value) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get data space")
 
 done:
@@ -501,7 +501,7 @@ H5Dget_space_status(hid_t dset_id, H5D_space_status_t *allocation)
 
     /* Read data space address through the VOL and return */
     if((ret_value=H5VL_dataset_get(dset, vol_plugin, H5VL_DATASET_GET_SPACE_STATUS, 
-				   H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, allocation)) < 0)
+				   H5AC_dxpl_id, H5_EVENT_STACK_NULL, allocation)) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get space status")
 
 done:
@@ -543,7 +543,7 @@ H5Dget_type(hid_t dset_id)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid dataset identifier")
 
     /* get the datatype through the VOL */
-    if(H5VL_dataset_get(dset, vol_plugin, H5VL_DATASET_GET_TYPE, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, &ret_value) < 0)
+    if(H5VL_dataset_get(dset, vol_plugin, H5VL_DATASET_GET_TYPE, H5AC_dxpl_id, H5_EVENT_STACK_NULL, &ret_value) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get datatype")
 
 done:
@@ -584,7 +584,7 @@ H5Dget_create_plist(hid_t dset_id)
     if(NULL == (dset = (void *)H5I_object(dset_id)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid dataset identifier")
 
-    if(H5VL_dataset_get(dset, vol_plugin, H5VL_DATASET_GET_DCPL, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, &ret_value) < 0)
+    if(H5VL_dataset_get(dset, vol_plugin, H5VL_DATASET_GET_DCPL, H5AC_dxpl_id, H5_EVENT_STACK_NULL, &ret_value) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get dataset creation properties")
 
 done:
@@ -642,7 +642,7 @@ H5Dget_access_plist(hid_t dset_id)
     if(NULL == (dset = (void *)H5I_object(dset_id)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid dataset identifier")
 
-    if(H5VL_dataset_get(dset, vol_plugin, H5VL_DATASET_GET_DAPL, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, &ret_value) < 0)
+    if(H5VL_dataset_get(dset, vol_plugin, H5VL_DATASET_GET_DAPL, H5AC_dxpl_id, H5_EVENT_STACK_NULL, &ret_value) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get dataset access properties")
 done:
 
@@ -686,7 +686,7 @@ H5Dget_storage_size(hid_t dset_id)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, 0, "invalid dataset identifier")
 
     /* get storage size through the VOL */
-    if(H5VL_dataset_get(dset, vol_plugin, H5VL_DATASET_GET_STORAGE_SIZE, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, &ret_value) < 0)
+    if(H5VL_dataset_get(dset, vol_plugin, H5VL_DATASET_GET_STORAGE_SIZE, H5AC_dxpl_id, H5_EVENT_STACK_NULL, &ret_value) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, 0, "unable to get storage size")
 
 done:
@@ -726,7 +726,7 @@ H5Dget_offset(hid_t dset_id)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, HADDR_UNDEF, "invalid dataset identifier")
 
     /* get offset through the VOL */
-    if(H5VL_dataset_get(dset, vol_plugin, H5VL_DATASET_GET_OFFSET, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, &ret_value) < 0)
+    if(H5VL_dataset_get(dset, vol_plugin, H5VL_DATASET_GET_OFFSET, H5AC_dxpl_id, H5_EVENT_STACK_NULL, &ret_value) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, HADDR_UNDEF, "unable to get offset")
 
 done:
@@ -935,7 +935,7 @@ H5Dvlen_get_buf_size(hid_t dataset_id, hid_t type_id, hid_t space_id,
 
     /* Get a copy of the dataspace ID */
     if(H5VL_dataset_get(dset, vol_plugin, H5VL_DATASET_GET_SPACE, H5AC_dxpl_id, 
-		        H5_EVENT_QUEUE_NULL, &vlen_bufsize.fspace_id) < 0)
+		        H5_EVENT_STACK_NULL, &vlen_bufsize.fspace_id) < 0)
         HGOTO_ERROR(H5E_DATASPACE, H5E_CANTCOPY, FAIL, "can't copy dataspace")
 
     /* Create a scalar for the memory dataspace */
@@ -1032,7 +1032,7 @@ H5Dset_extent(hid_t dset_id, const hsize_t size[])
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid dataset identifier")
 
     /* set the extent through the VOL */
-    if((ret_value = H5VL_dataset_set_extent(dset, vol_plugin, size, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+    if((ret_value = H5VL_dataset_set_extent(dset, vol_plugin, size, H5AC_dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to set extent of dataset")
 
 done:
@@ -1062,7 +1062,7 @@ H5D_close_dataset(void *dset, H5VL_t *vol_plugin)
     FUNC_ENTER_NOAPI_NOINIT
 
     /* Close the dataset through the VOL*/
-    if((ret_value = H5VL_dataset_close(dset, vol_plugin, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+    if((ret_value = H5VL_dataset_close(dset, vol_plugin, H5AC_dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_DATASET, H5E_CLOSEERROR, FAIL, "unable to close dataset")
 
 done:
diff --git a/src/H5Ddeprec.c b/src/H5Ddeprec.c
index a9c94a4..a972eca 100644
--- a/src/H5Ddeprec.c
+++ b/src/H5Ddeprec.c
@@ -183,7 +183,7 @@ H5Dcreate1(hid_t loc_id, const char *name, hid_t type_id, hid_t space_id,
 
     /* Create the dataset through the VOL */
     if(NULL == (dset = H5VL_dataset_create(obj, loc_params, vol_plugin, name, dcpl_id, 
-                                           H5P_DATASET_ACCESS_DEFAULT, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)))
+                                           H5P_DATASET_ACCESS_DEFAULT, H5AC_dxpl_id, H5_EVENT_STACK_NULL)))
 	HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to create dataset")
 
     /* Get an atom for the dataset */
@@ -192,7 +192,7 @@ H5Dcreate1(hid_t loc_id, const char *name, hid_t type_id, hid_t space_id,
 
 done:
     if (ret_value < 0 && dset)
-        if(H5VL_dataset_close (dset, vol_plugin, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL) < 0)
+        if(H5VL_dataset_close (dset, vol_plugin, H5AC_dxpl_id, H5_EVENT_STACK_NULL) < 0)
             HDONE_ERROR(H5E_DATASET, H5E_CLOSEERROR, FAIL, "unable to release dataset")
     FUNC_LEAVE_API(ret_value)
 } /* end H5Dcreate1() */
@@ -244,7 +244,7 @@ H5Dopen1(hid_t loc_id, const char *name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
 
     /* Create the dataset through the VOL */
-    if(NULL == (dset = H5VL_dataset_open(obj, loc_params, vol_plugin, name, dapl_id, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)))
+    if(NULL == (dset = H5VL_dataset_open(obj, loc_params, vol_plugin, name, dapl_id, H5AC_dxpl_id, H5_EVENT_STACK_NULL)))
 	HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to create dataset")
 
     /* Get an atom for the dataset */
@@ -253,7 +253,7 @@ H5Dopen1(hid_t loc_id, const char *name)
 
 done:
     if (ret_value < 0 && dset)
-        if(H5VL_dataset_close (dset, vol_plugin, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL) < 0)
+        if(H5VL_dataset_close (dset, vol_plugin, H5AC_dxpl_id, H5_EVENT_STACK_NULL) < 0)
             HDONE_ERROR(H5E_DATASET, H5E_CLOSEERROR, FAIL, "unable to release dataset")
     FUNC_LEAVE_API(ret_value)
 } /* end H5Dopen1() */
diff --git a/src/H5Dint.c b/src/H5Dint.c
index 7dbb64c..af81244 100644
--- a/src/H5Dint.c
+++ b/src/H5Dint.c
@@ -2077,7 +2077,7 @@ H5D__vlen_get_buf_size(void UNUSED *elem, hid_t type_id, unsigned UNUSED ndim, c
     if(H5VL_dataset_read(vlen_bufsize->dset, vlen_bufsize->vol_plugin, 
                          type_id, vlen_bufsize->mspace_id, 
                          vlen_bufsize->fspace_id, vlen_bufsize->xfer_pid, 
-                         vlen_bufsize->fl_tbuf, H5_EVENT_QUEUE_NULL) < 0)
+                         vlen_bufsize->fl_tbuf, H5_EVENT_STACK_NULL) < 0)
 	HGOTO_ERROR(H5E_DATASET, H5E_READERROR, FAIL, "can't read data")
 
 done:
diff --git a/src/H5Dio.c b/src/H5Dio.c
index f67a40f..e4ea7af 100644
--- a/src/H5Dio.c
+++ b/src/H5Dio.c
@@ -143,7 +143,7 @@ H5Dread(hid_t dset_id, hid_t mem_type_id, hid_t mem_space_id,
 
     /* Read the data through the VOL */
     if((ret_value = H5VL_dataset_read(dset, vol_plugin, mem_type_id, mem_space_id, 
-                                      file_space_id, plist_id, buf, H5_EVENT_QUEUE_NULL)) < 0)
+                                      file_space_id, plist_id, buf, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_DATASET, H5E_READERROR, FAIL, "can't read data")
 
 
@@ -215,7 +215,7 @@ H5Dwrite(hid_t dset_id, hid_t mem_type_id, hid_t mem_space_id,
 
     /* Write the data through the VOL */
     if((ret_value = H5VL_dataset_write(dset, vol_plugin, mem_type_id, mem_space_id, 
-                                       file_space_id, dxpl_id, buf, H5_EVENT_QUEUE_NULL)) < 0)
+                                       file_space_id, dxpl_id, buf, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_DATASET, H5E_WRITEERROR, FAIL, "can't write data")
 
 done:
diff --git a/src/H5F.c b/src/H5F.c
index 808f162..81d154e 100644
--- a/src/H5F.c
+++ b/src/H5F.c
@@ -213,7 +213,7 @@ H5Fget_create_plist(hid_t file_id)
     if (NULL == (vol_plugin = (H5VL_t *)H5I_get_aux(file_id)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
 
-    if(H5VL_file_get(obj, vol_plugin, H5VL_FILE_GET_FCPL, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, &ret_value) < 0)
+    if(H5VL_file_get(obj, vol_plugin, H5VL_FILE_GET_FCPL, H5AC_dxpl_id, H5_EVENT_STACK_NULL, &ret_value) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get file creation properties")
 
 done:
@@ -259,7 +259,7 @@ H5Fget_access_plist(hid_t file_id)
     if (NULL == (vol_plugin = (H5VL_t *)H5I_get_aux(file_id)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
 
-    if(H5VL_file_get(obj, vol_plugin, H5VL_FILE_GET_FAPL, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, &ret_value) < 0)
+    if(H5VL_file_get(obj, vol_plugin, H5VL_FILE_GET_FAPL, H5AC_dxpl_id, H5_EVENT_STACK_NULL, &ret_value) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get file creation properties")
 
 done:
@@ -302,7 +302,7 @@ H5Fget_obj_count(hid_t file_id, unsigned types)
         if (NULL == (vol_plugin = (H5VL_t *)H5I_get_aux(file_id)))
             HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
 
-        if(H5VL_file_get(obj, vol_plugin, H5VL_FILE_GET_OBJ_COUNT, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, types, &ret_value) < 0)
+        if(H5VL_file_get(obj, vol_plugin, H5VL_FILE_GET_OBJ_COUNT, H5AC_dxpl_id, H5_EVENT_STACK_NULL, types, &ret_value) < 0)
             HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get object count in file(s)")
     }
     /* iterate over all open files and get the obj count for each */
@@ -362,7 +362,7 @@ H5Fget_obj_ids(hid_t file_id, unsigned types, size_t max_objs, hid_t *oid_list)
         if(NULL == (obj = (void *)H5I_object(file_id)))
             HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid file identifier")
 
-        if(H5VL_file_get(obj, vol_plugin, H5VL_FILE_GET_OBJ_IDS, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, 
+        if(H5VL_file_get(obj, vol_plugin, H5VL_FILE_GET_OBJ_IDS, H5AC_dxpl_id, H5_EVENT_STACK_NULL, 
                          types, max_objs, oid_list, &ret_value) < 0)
             HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get object count in file(s)")
     }
@@ -421,7 +421,7 @@ H5Fget_vfd_handle(hid_t file_id, hid_t fapl, void **file_handle)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid file identifier")
 
     if((ret_value = H5VL_file_optional(obj, vol_plugin, H5VL_FILE_GET_VFD_HANDLE, 
-                                       H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, file_handle, fapl)) < 0)
+                                       H5AC_dxpl_id, H5_EVENT_STACK_NULL, file_handle, fapl)) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get file handle")
 
 done:
@@ -461,7 +461,7 @@ H5Fis_accessible(const char *name, hid_t fapl_id)
         if(TRUE != H5P_isa_class(fapl_id, H5P_FILE_ACCESS))
             HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not file access property list")
 
-    if(H5VL_file_misc(NULL, NULL, H5VL_FILE_IS_ACCESSIBLE, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, 
+    if(H5VL_file_misc(NULL, NULL, H5VL_FILE_IS_ACCESSIBLE, H5AC_dxpl_id, H5_EVENT_STACK_NULL, 
                       fapl_id, name, &ret_value) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get file handle")
 
@@ -534,7 +534,7 @@ H5Fcreate(const char *filename, unsigned flags, hid_t fcpl_id, hid_t fapl_id)
             HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not file access property list")
 
     /* create a new file or truncate an existing file through the VOL */
-    if(NULL == (file = H5VL_file_create(&vol_plugin, filename, flags, fcpl_id, fapl_id, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)))
+    if(NULL == (file = H5VL_file_create(&vol_plugin, filename, flags, fcpl_id, fapl_id, H5AC_dxpl_id, H5_EVENT_STACK_NULL)))
 	HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, FAIL, "unable to create file")
 
     /* Get an atom for the file with the VOL information as the auxilary struct*/
@@ -610,7 +610,7 @@ H5Fopen(const char *filename, unsigned flags, hid_t fapl_id)
             HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not file access property list")
 
     /* Open the file through the VOL layer */
-    if(NULL == (file = H5VL_file_open(&vol_plugin, filename, flags, fapl_id, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)))
+    if(NULL == (file = H5VL_file_open(&vol_plugin, filename, flags, fapl_id, H5AC_dxpl_id, H5_EVENT_STACK_NULL)))
 	HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, FAIL, "unable to create file")
 
     /* Get an atom for the file with the VOL information as the auxilary struct*/
@@ -665,7 +665,7 @@ H5Fflush(hid_t object_id, H5F_scope_t scope)
     loc_params.type = H5VL_OBJECT_BY_SELF;
     loc_params.obj_type = obj_type;
 
-    if((ret_value = H5VL_file_flush(obj, loc_params, vol_plugin, scope, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+    if((ret_value = H5VL_file_flush(obj, loc_params, vol_plugin, scope, H5AC_dxpl_id, H5_EVENT_STACK_NULL)) < 0)
         HGOTO_ERROR(H5E_FILE, H5E_CANTFLUSH, FAIL, "unable to flush file")
 
 done:
@@ -722,7 +722,7 @@ H5Fclose(hid_t file_id)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid file identifier")
 
     /* Close the file through the VOL*/
-    if((ret_value = H5VL_file_close(file, vol_plugin, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+    if((ret_value = H5VL_file_close(file, vol_plugin, H5AC_dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_FILE, H5E_CANTCLOSEFILE, FAIL, "unable to close file")
 
     H5MM_free(vol_plugin);
@@ -755,7 +755,7 @@ H5F_close_file(void *file, H5VL_t *vol_plugin)
     FUNC_ENTER_NOAPI_NOINIT
 
     /* Close the file through the VOL*/
-    if((ret_value = H5VL_file_close(file, vol_plugin, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+    if((ret_value = H5VL_file_close(file, vol_plugin, H5AC_dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_FILE, H5E_CANTCLOSEFILE, FAIL, "unable to close file")
 done:
     FUNC_LEAVE_NOAPI(ret_value)
@@ -803,7 +803,7 @@ H5Freopen(hid_t file_id)
     if(NULL == (obj = (void *)H5I_object(file_id)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid file identifier")
 
-    if(H5VL_file_optional(obj, vol_plugin, H5VL_FILE_REOPEN, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, &file) < 0)
+    if(H5VL_file_optional(obj, vol_plugin, H5VL_FILE_REOPEN, H5AC_dxpl_id, H5_EVENT_STACK_NULL, &file) < 0)
 	HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, FAIL, "unable to reopen file")
 
     if (NULL == file)
@@ -852,7 +852,7 @@ H5Fget_intent(hid_t file_id, unsigned *intent_flags)
         if(NULL == (obj = (void *)H5I_object(file_id)))
             HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid file identifier")
 
-        if((ret_value = H5VL_file_get(obj, vol_plugin, H5VL_FILE_GET_INTENT, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, intent_flags)) < 0)
+        if((ret_value = H5VL_file_get(obj, vol_plugin, H5VL_FILE_GET_INTENT, H5AC_dxpl_id, H5_EVENT_STACK_NULL, intent_flags)) < 0)
             HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get file intent")
     }
 
@@ -893,7 +893,7 @@ H5Fget_freespace(hid_t file_id)
     if(NULL == (obj = (void *)H5I_object(file_id)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid file identifier")
 
-    if(H5VL_file_optional(obj, vol_plugin, H5VL_FILE_GET_FREE_SPACE, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, &ret_value) < 0)
+    if(H5VL_file_optional(obj, vol_plugin, H5VL_FILE_GET_FREE_SPACE, H5AC_dxpl_id, H5_EVENT_STACK_NULL, &ret_value) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get file free space")
 
 done:
@@ -936,7 +936,7 @@ H5Fget_filesize(hid_t file_id, hsize_t *size)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "not a file ID")
 
     if((ret_value = H5VL_file_optional(file, vol_plugin, H5VL_FILE_GET_SIZE, 
-				       H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, size)) < 0)
+				       H5AC_dxpl_id, H5_EVENT_STACK_NULL, size)) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get file size")
 
 done:
@@ -1008,7 +1008,7 @@ H5Fget_file_image(hid_t file_id, void *buf_ptr, size_t buf_len)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid file identifier")
 
     /* get image through the VOL */
-    if(H5VL_file_optional(obj, vol_plugin, H5VL_FILE_GET_FILE_IMAGE, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, 
+    if(H5VL_file_optional(obj, vol_plugin, H5VL_FILE_GET_FILE_IMAGE, H5AC_dxpl_id, H5_EVENT_STACK_NULL, 
                           buf_ptr, &ret_value, buf_len) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get file image")
 
@@ -1057,7 +1057,7 @@ H5Fget_mdc_config(hid_t file_id, H5AC_cache_config_t *config_ptr)
     if(NULL == (obj = (void *)H5I_object(file_id)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid file identifier")
 
-    if((ret_value = H5VL_file_optional(obj, vol_plugin, H5VL_FILE_GET_MDC_CONF, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, 
+    if((ret_value = H5VL_file_optional(obj, vol_plugin, H5VL_FILE_GET_MDC_CONF, H5AC_dxpl_id, H5_EVENT_STACK_NULL, 
                                        config_ptr)) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get mdc configuration")
 
@@ -1098,7 +1098,7 @@ H5Fset_mdc_config(hid_t file_id, H5AC_cache_config_t *config_ptr)
     if(NULL == (obj = (void *)H5I_object(file_id)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid file identifier")
 
-    if(H5VL_file_optional(obj, vol_plugin, H5VL_FILE_SET_MDC_CONFIG, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, config_ptr) < 0)
+    if(H5VL_file_optional(obj, vol_plugin, H5VL_FILE_SET_MDC_CONFIG, H5AC_dxpl_id, H5_EVENT_STACK_NULL, config_ptr) < 0)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "uanvle to set MDC configuration")
 
 done:
@@ -1143,7 +1143,7 @@ H5Fget_mdc_hit_rate(hid_t file_id, double *hit_rate_ptr)
     if(NULL == (obj = (void *)H5I_object(file_id)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid file identifier")
 
-    if((ret_value = H5VL_file_optional(obj, vol_plugin, H5VL_FILE_GET_MDC_HR, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, 
+    if((ret_value = H5VL_file_optional(obj, vol_plugin, H5VL_FILE_GET_MDC_HR, H5AC_dxpl_id, H5_EVENT_STACK_NULL, 
                                        hit_rate_ptr)) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get MDC hit rate")
 
@@ -1189,7 +1189,7 @@ H5Fget_mdc_size(hid_t file_id, size_t *max_size_ptr, size_t *min_clean_size_ptr,
     if(NULL == (obj = (void *)H5I_object(file_id)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid file identifier")
 
-    if((ret_value = H5VL_file_optional(obj, vol_plugin, H5VL_FILE_GET_MDC_SIZE, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, max_size_ptr, 
+    if((ret_value = H5VL_file_optional(obj, vol_plugin, H5VL_FILE_GET_MDC_SIZE, H5AC_dxpl_id, H5_EVENT_STACK_NULL, max_size_ptr, 
                                        min_clean_size_ptr, cur_size_ptr, cur_num_entries_ptr)) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get MDC size")
 
@@ -1236,7 +1236,7 @@ H5Freset_mdc_hit_rate_stats(hid_t file_id)
     if(NULL == (obj = (void *)H5I_object(file_id)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid file identifier")
 
-    if(H5VL_file_optional(obj, vol_plugin, H5VL_FILE_RESET_MDC_HIT_RATE, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL) < 0)
+    if(H5VL_file_optional(obj, vol_plugin, H5VL_FILE_RESET_MDC_HIT_RATE, H5AC_dxpl_id, H5_EVENT_STACK_NULL) < 0)
         HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "can't reset cache hit rate")
 
 done:
@@ -1291,7 +1291,7 @@ H5Fget_name(hid_t obj_id, char *name/*out*/, size_t size)
     if(NULL == (obj = (void *)H5VL_get_object(obj_id)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid file identifier")
 
-    if(H5VL_file_get(obj, vol_plugin, H5VL_FILE_GET_NAME, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL,
+    if(H5VL_file_get(obj, vol_plugin, H5VL_FILE_GET_NAME, H5AC_dxpl_id, H5_EVENT_STACK_NULL,
                      type, size, name, &ret_value) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get file name")
 
@@ -1346,7 +1346,7 @@ H5Fget_info2(hid_t obj_id, H5F_info2_t *finfo)
     if(NULL == (obj = (void *)H5VL_get_object(obj_id)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid file identifier")
 
-    if((ret_value = H5VL_file_optional(obj, vol_plugin, H5VL_FILE_GET_INFO, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, 
+    if((ret_value = H5VL_file_optional(obj, vol_plugin, H5VL_FILE_GET_INFO, H5AC_dxpl_id, H5_EVENT_STACK_NULL, 
                                        type, finfo)) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get file info")
 done:
@@ -1392,7 +1392,7 @@ H5Fget_free_sections(hid_t file_id, H5F_mem_t type, size_t nsects,
     if(NULL == (obj = (void *)H5I_object(file_id)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid file identifier")
 
-    if(H5VL_file_optional(obj, vol_plugin, H5VL_FILE_GET_FREE_SECTIONS, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, sect_info, 
+    if(H5VL_file_optional(obj, vol_plugin, H5VL_FILE_GET_FREE_SECTIONS, H5AC_dxpl_id, H5_EVENT_STACK_NULL, sect_info, 
                           &ret_value, type, nsects) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get file free sections")
 done:
@@ -1432,7 +1432,7 @@ H5Fclear_elink_file_cache(hid_t file_id)
     if(NULL == (obj = (void *)H5I_object(file_id)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid file identifier")
 
-    if(H5VL_file_optional(obj, vol_plugin, H5VL_FILE_CLEAR_ELINK_CACHE, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL) < 0)
+    if(H5VL_file_optional(obj, vol_plugin, H5VL_FILE_CLEAR_ELINK_CACHE, H5AC_dxpl_id, H5_EVENT_STACK_NULL) < 0)
         HGOTO_ERROR(H5E_FILE, H5E_CANTRELEASE, FAIL, "can't release external file cache")
 
 done:
diff --git a/src/H5Fint.c b/src/H5Fint.c
index 1a5514f..096b93b 100644
--- a/src/H5Fint.c
+++ b/src/H5Fint.c
@@ -227,7 +227,7 @@ H5F_get_obj_count_cb(void UNUSED *obj_ptr, hid_t obj_id, void *key)
     if(NULL == (obj = (void *)H5I_object(obj_id)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid file identifier")
 
-    if(H5VL_file_get(obj, vol_plugin, H5VL_FILE_GET_OBJ_COUNT, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, 
+    if(H5VL_file_get(obj, vol_plugin, H5VL_FILE_GET_OBJ_COUNT, H5AC_dxpl_id, H5_EVENT_STACK_NULL, 
                      udata->types, &obj_count) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, H5_ITER_ERROR, "unable to get object count in file(s)")
 
@@ -303,7 +303,7 @@ H5F_get_obj_ids_cb(void UNUSED *obj_ptr, hid_t obj_id, void *key)
     if(NULL == (obj = (void *)H5I_object(obj_id)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid file identifier")
 
-    if(H5VL_file_get(obj, vol_plugin, H5VL_FILE_GET_OBJ_IDS, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, udata->types,
+    if(H5VL_file_get(obj, vol_plugin, H5VL_FILE_GET_OBJ_IDS, H5AC_dxpl_id, H5_EVENT_STACK_NULL, udata->types,
                      udata->max_objs, udata->oid_list, &obj_count) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, H5_ITER_ERROR, "unable to get object count in file(s)")
 
diff --git a/src/H5Fmount.c b/src/H5Fmount.c
index 285eccd..590275a 100644
--- a/src/H5Fmount.c
+++ b/src/H5Fmount.c
@@ -509,7 +509,7 @@ H5Fmount(hid_t loc_id, const char *name, hid_t child_id, hid_t plist_id)
     if(NULL == (file = (void *)H5I_object(child_id)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid file identifier")
 
-    if((ret_value = H5VL_file_misc(obj, vol_plugin1, H5VL_FILE_MOUNT, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, 
+    if((ret_value = H5VL_file_misc(obj, vol_plugin1, H5VL_FILE_MOUNT, H5AC_dxpl_id, H5_EVENT_STACK_NULL, 
                                    type, name, file, plist_id)) < 0)
 	HGOTO_ERROR(H5E_FILE, H5E_MOUNT, FAIL, "unable to mount file")
 
@@ -565,7 +565,7 @@ H5Funmount(hid_t loc_id, const char *name)
     if(NULL == (obj = (void *)H5I_object(loc_id)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid file identifier")
 
-    if((ret_value = H5VL_file_misc(obj, vol_plugin, H5VL_FILE_UNMOUNT, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, type, name)) < 0)
+    if((ret_value = H5VL_file_misc(obj, vol_plugin, H5VL_FILE_UNMOUNT, H5AC_dxpl_id, H5_EVENT_STACK_NULL, type, name)) < 0)
 	HGOTO_ERROR(H5E_FILE, H5E_MOUNT, FAIL, "unable to unmount file")
 
 done:
diff --git a/src/H5G.c b/src/H5G.c
index f5e39b5..62c9235 100644
--- a/src/H5G.c
+++ b/src/H5G.c
@@ -324,7 +324,7 @@ H5Gcreate2(hid_t loc_id, const char *name, hid_t lcpl_id, hid_t gcpl_id, hid_t g
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
 
     /* Create the group through the VOL */
-    if(NULL == (grp = H5VL_group_create(obj, loc_params, vol_plugin, name, gcpl_id, gapl_id, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)))
+    if(NULL == (grp = H5VL_group_create(obj, loc_params, vol_plugin, name, gcpl_id, gapl_id, H5AC_dxpl_id, H5_EVENT_STACK_NULL)))
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to create group")
 
     /* Get an atom for the group */
@@ -333,7 +333,7 @@ H5Gcreate2(hid_t loc_id, const char *name, hid_t lcpl_id, hid_t gcpl_id, hid_t g
 
 done:
     if (ret_value < 0 && grp)
-        if(H5VL_group_close (grp, vol_plugin, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL) < 0)
+        if(H5VL_group_close (grp, vol_plugin, H5AC_dxpl_id, H5_EVENT_STACK_NULL) < 0)
             HDONE_ERROR(H5E_SYM, H5E_CLOSEERROR, FAIL, "unable to release group")
     FUNC_LEAVE_API(ret_value)
 } /* end H5Gcreate2() */
@@ -412,7 +412,7 @@ H5Gcreate_anon(hid_t loc_id, hid_t gcpl_id, hid_t gapl_id)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
 
     /* Create the group through the VOL */
-    if(NULL == (grp = H5VL_group_create(obj, loc_params, vol_plugin, NULL, gcpl_id, gapl_id, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)))
+    if(NULL == (grp = H5VL_group_create(obj, loc_params, vol_plugin, NULL, gcpl_id, gapl_id, H5AC_dxpl_id, H5_EVENT_STACK_NULL)))
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to create group")
 
     /* Get an atom for the group */
@@ -421,7 +421,7 @@ H5Gcreate_anon(hid_t loc_id, hid_t gcpl_id, hid_t gapl_id)
 
 done:
     if (ret_value < 0 && grp)
-        if(H5VL_group_close (grp, vol_plugin, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL) < 0)
+        if(H5VL_group_close (grp, vol_plugin, H5AC_dxpl_id, H5_EVENT_STACK_NULL) < 0)
             HDONE_ERROR(H5E_SYM, H5E_CLOSEERROR, FAIL, "unable to release group")
     FUNC_LEAVE_API(ret_value)
 } /* end H5Gcreate_anon() */
@@ -479,7 +479,7 @@ H5Gopen2(hid_t loc_id, const char *name, hid_t gapl_id)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
 
     /* Create the group through the VOL */
-    if(NULL == (grp = H5VL_group_open(obj, loc_params, vol_plugin, name, gapl_id, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)))
+    if(NULL == (grp = H5VL_group_open(obj, loc_params, vol_plugin, name, gapl_id, H5AC_dxpl_id, H5_EVENT_STACK_NULL)))
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to create group")
 
     /* Get an atom for the group */
@@ -488,7 +488,7 @@ H5Gopen2(hid_t loc_id, const char *name, hid_t gapl_id)
 
 done:
     if (ret_value < 0 && grp)
-        if(H5VL_group_close (grp, vol_plugin, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL) < 0)
+        if(H5VL_group_close (grp, vol_plugin, H5AC_dxpl_id, H5_EVENT_STACK_NULL) < 0)
             HDONE_ERROR(H5E_SYM, H5E_CLOSEERROR, FAIL, "unable to release group")
     FUNC_LEAVE_API(ret_value)
 } /* end H5Gopen2() */
@@ -527,7 +527,7 @@ H5Gget_create_plist(hid_t grp_id)
     if(NULL == (grp = (void *)H5I_object(grp_id)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid group identifier")
 
-    if(H5VL_group_get(grp, vol_plugin, H5VL_GROUP_GET_GCPL, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, &ret_value) < 0)
+    if(H5VL_group_get(grp, vol_plugin, H5VL_GROUP_GET_GCPL, H5AC_dxpl_id, H5_EVENT_STACK_NULL, &ret_value) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get group creation properties")
 
 done:
@@ -578,7 +578,7 @@ H5Gget_info(hid_t loc_id, H5G_info_t *grp_info)
     loc_params.obj_type = id_type;
 
     /* Get the group info through the VOL using the location token */
-    if((ret_value = H5VL_group_get(obj, vol_plugin, H5VL_GROUP_GET_INFO, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, 
+    if((ret_value = H5VL_group_get(obj, vol_plugin, H5VL_GROUP_GET_INFO, H5AC_dxpl_id, H5_EVENT_STACK_NULL, 
                                    loc_params, grp_info)) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get group info")
 
@@ -636,7 +636,7 @@ H5Gget_info_by_name(hid_t loc_id, const char *name, H5G_info_t *grp_info,
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid group identifier")
 
     /* Get the group info through the VOL using the location token */
-    if((ret_value = H5VL_group_get(obj, vol_plugin, H5VL_GROUP_GET_INFO, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, 
+    if((ret_value = H5VL_group_get(obj, vol_plugin, H5VL_GROUP_GET_INFO, H5AC_dxpl_id, H5_EVENT_STACK_NULL, 
                                    loc_params, grp_info)) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get group info")
 
@@ -703,7 +703,7 @@ H5Gget_info_by_idx(hid_t loc_id, const char *group_name, H5_index_t idx_type,
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid group identifier")
 
     /* Get the group info through the VOL using the location token */
-    if((ret_value = H5VL_group_get(obj, vol_plugin, H5VL_GROUP_GET_INFO, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, 
+    if((ret_value = H5VL_group_get(obj, vol_plugin, H5VL_GROUP_GET_INFO, H5AC_dxpl_id, H5_EVENT_STACK_NULL, 
                                    loc_params, grp_info)) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get group info")
 
@@ -745,7 +745,7 @@ H5Gclose(hid_t group_id)
     	HGOTO_ERROR(H5E_SYM, H5E_CANTRELEASE, FAIL, "unable to close group")
 #if 0
     /* Close the group through the VOL */
-    if(H5VL_group_close(group_id, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL) < 0)
+    if(H5VL_group_close(group_id, H5AC_dxpl_id, H5_EVENT_STACK_NULL) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_CANTRELEASE, FAIL, "unable to close group")
 #endif
 
@@ -776,7 +776,7 @@ H5G_close_group(void *grp, H5VL_t *vol_plugin)
     FUNC_ENTER_NOAPI_NOINIT
 
     /* Close the group through the VOL*/
-    if((ret_value = H5VL_group_close(grp, vol_plugin, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+    if((ret_value = H5VL_group_close(grp, vol_plugin, H5AC_dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_CLOSEERROR, FAIL, "unable to close group")
 
 done:
diff --git a/src/H5Gdeprec.c b/src/H5Gdeprec.c
index 58c791b..e4fed3e 100644
--- a/src/H5Gdeprec.c
+++ b/src/H5Gdeprec.c
@@ -263,7 +263,7 @@ H5Gcreate1(hid_t loc_id, const char *name, size_t size_hint)
 
     /* Create the group through the VOL */
     if(NULL == (grp = H5VL_group_create(obj, loc_params, vol_plugin, name, tmp_gcpl, 
-                                        H5P_GROUP_ACCESS_DEFAULT, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)))
+                                        H5P_GROUP_ACCESS_DEFAULT, H5AC_dxpl_id, H5_EVENT_STACK_NULL)))
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to create group")
 
     /* Get an atom for the group */
@@ -275,7 +275,7 @@ done:
         if(H5I_dec_ref(tmp_gcpl) < 0)
             HDONE_ERROR(H5E_SYM, H5E_CLOSEERROR, FAIL, "unable to release property list")
     if (ret_value < 0 && grp)
-        if(H5VL_group_close (grp, vol_plugin, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL) < 0)
+        if(H5VL_group_close (grp, vol_plugin, H5AC_dxpl_id, H5_EVENT_STACK_NULL) < 0)
             HDONE_ERROR(H5E_SYM, H5E_CLOSEERROR, FAIL, "unable to release group")
 
     FUNC_LEAVE_API(ret_value)
@@ -327,7 +327,7 @@ H5Gopen1(hid_t loc_id, const char *name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
 
     /* Create the group through the VOL */
-    if(NULL == (grp = H5VL_group_open(obj, loc_params, vol_plugin, name, H5P_DEFAULT, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)))
+    if(NULL == (grp = H5VL_group_open(obj, loc_params, vol_plugin, name, H5P_DEFAULT, H5AC_dxpl_id, H5_EVENT_STACK_NULL)))
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to create group")
 
     /* Get an atom for the group */
@@ -336,7 +336,7 @@ H5Gopen1(hid_t loc_id, const char *name)
 
 done:
     if (ret_value < 0 && grp)
-        if(H5VL_group_close (grp, vol_plugin, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL) < 0)
+        if(H5VL_group_close (grp, vol_plugin, H5AC_dxpl_id, H5_EVENT_STACK_NULL) < 0)
             HDONE_ERROR(H5E_SYM, H5E_CLOSEERROR, FAIL, "unable to release group")
     FUNC_LEAVE_API(ret_value)
 } /* end H5Gopen1() */
@@ -400,7 +400,7 @@ H5Glink(hid_t cur_loc_id, H5G_link_t type, const char *cur_name, const char *new
 
         /* Create the link through the VOL */
         if((ret_value = H5VL_link_create(H5VL_LINK_CREATE_HARD, NULL, loc_params2, vol_plugin,
-                                         lcpl_id, H5P_DEFAULT, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+                                         lcpl_id, H5P_DEFAULT, H5AC_dxpl_id, H5_EVENT_STACK_NULL)) < 0)
             HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to create link")
     } /* end if */
     else if(type == H5L_TYPE_SOFT) {
@@ -426,7 +426,7 @@ H5Glink(hid_t cur_loc_id, H5G_link_t type, const char *cur_name, const char *new
 
         /* Create the link through the VOL */
         if((ret_value = H5VL_link_create(H5VL_LINK_CREATE_SOFT, obj, loc_params, vol_plugin, 
-                                         lcpl_id, H5P_DEFAULT, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+                                         lcpl_id, H5P_DEFAULT, H5AC_dxpl_id, H5_EVENT_STACK_NULL)) < 0)
             HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to create link")
     } /* end else if */
     else
@@ -507,7 +507,7 @@ H5Glink2(hid_t cur_loc_id, const char *cur_name, H5G_link_t type,
         /* Create the link through the VOL */
         if((ret_value = H5VL_link_create(H5VL_LINK_CREATE_HARD, obj2, loc_params2, 
                                          (vol_plugin1!=NULL ? vol_plugin1 : vol_plugin2),
-                                         lcpl_id, H5P_DEFAULT, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+                                         lcpl_id, H5P_DEFAULT, H5AC_dxpl_id, H5_EVENT_STACK_NULL)) < 0)
             HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to create link")
     } /* end if */
     else if(type == H5L_TYPE_SOFT) {
@@ -538,7 +538,7 @@ H5Glink2(hid_t cur_loc_id, const char *cur_name, H5G_link_t type,
 
         /* Create the link through the VOL */
         if((ret_value = H5VL_link_create(H5VL_LINK_CREATE_SOFT, obj, loc_params, vol_plugin, 
-                                         lcpl_id, H5P_DEFAULT, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+                                         lcpl_id, H5P_DEFAULT, H5AC_dxpl_id, H5_EVENT_STACK_NULL)) < 0)
             HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to create link")
     } /* end else if */
     else
@@ -586,7 +586,7 @@ H5Gmove(hid_t src_loc_id, const char *src_name, const char *dst_name)
 
     /* Create the link through the VOL */
     if((ret_value = H5VL_link_move(obj, loc_params1, NULL, loc_params2, vol_plugin,
-                                   FALSE, H5P_DEFAULT, H5P_DEFAULT, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+                                   FALSE, H5P_DEFAULT, H5P_DEFAULT, H5AC_dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to create link")
 
 done:
@@ -652,7 +652,7 @@ H5Gmove2(hid_t src_loc_id, const char *src_name, hid_t dst_loc_id,
     /* Move the link through the VOL */
     if((ret_value = H5VL_link_move(obj1, loc_params1, obj2, loc_params2, 
                                    (vol_plugin1!=NULL ? vol_plugin1 : vol_plugin2), 
-                                   FALSE, H5P_DEFAULT, H5P_DEFAULT, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+                                   FALSE, H5P_DEFAULT, H5P_DEFAULT, H5AC_dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to create link")
 
 done:
@@ -694,7 +694,7 @@ H5Gunlink(hid_t loc_id, const char *name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
 
     /* Delete the link through the VOL */
-    if((ret_value = H5VL_link_remove(obj, loc_params, vol_plugin, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+    if((ret_value = H5VL_link_remove(obj, loc_params, vol_plugin, H5AC_dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to create link")
 
 done:
@@ -739,7 +739,7 @@ H5Gget_linkval(hid_t loc_id, const char *name, size_t size, char *buf/*out*/)
 
     /* Get the link info through the VOL */
     if((ret_value = H5VL_link_get(obj, loc_params, vol_plugin, H5VL_LINK_GET_VAL, 
-                                  H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, buf, size)) < 0)
+                                  H5AC_dxpl_id, H5_EVENT_STACK_NULL, buf, size)) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get link value")
 
 done:
@@ -791,7 +791,7 @@ H5Gset_comment(hid_t loc_id, const char *name, const char *comment)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
 
     /* set comment on object through the VOL */
-    if(H5VL_object_misc(obj, loc_params, vol_plugin, H5VL_OBJECT_SET_COMMENT, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, comment) < 0)
+    if(H5VL_object_misc(obj, loc_params, vol_plugin, H5VL_OBJECT_SET_COMMENT, H5AC_dxpl_id, H5_EVENT_STACK_NULL, comment) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to set comment value")
 
 done:
@@ -851,7 +851,7 @@ H5Gget_comment(hid_t loc_id, const char *name, size_t bufsize, char *buf)
     if (NULL == (vol_plugin = (H5VL_t *)H5I_get_aux(loc_id)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
 
-    if(H5VL_object_get(obj, loc_params, vol_plugin, H5VL_OBJECT_GET_COMMENT, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, 
+    if(H5VL_object_get(obj, loc_params, vol_plugin, H5VL_OBJECT_GET_COMMENT, H5AC_dxpl_id, H5_EVENT_STACK_NULL, 
                        buf, bufsize, &size) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get object comment")
 
diff --git a/src/H5I.c b/src/H5I.c
index 36e99e5..cc0efdf 100644
--- a/src/H5I.c
+++ b/src/H5I.c
@@ -2323,7 +2323,7 @@ H5Iget_file_id(hid_t obj_id)
         }
 
         /* Get the file through the VOL */
-        if(H5VL_file_get(obj, vol_plugin, H5VL_OBJECT_GET_FILE, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, type, &file) < 0)
+        if(H5VL_file_get(obj, vol_plugin, H5VL_OBJECT_GET_FILE, H5AC_dxpl_id, H5_EVENT_STACK_NULL, type, &file) < 0)
             HGOTO_ERROR(H5E_INTERNAL, H5E_CANTINIT, FAIL, "unable to get file")
 
         if (NULL == file)
diff --git a/src/H5L.c b/src/H5L.c
index 8d5f0aa..6fed2a4 100644
--- a/src/H5L.c
+++ b/src/H5L.c
@@ -330,7 +330,7 @@ H5Lmove(hid_t src_loc_id, const char *src_name, hid_t dst_loc_id,
     /* Move the link through the VOL */
     if((ret_value = H5VL_link_move(obj1, loc_params1, obj2, loc_params2, 
                                    (vol_plugin1!=NULL ? vol_plugin1 : vol_plugin2), 
-                                   FALSE, lcpl_id, lapl_id, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+                                   FALSE, lcpl_id, lapl_id, H5AC_dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to create link")
 
 done:
@@ -421,7 +421,7 @@ H5Lcopy(hid_t src_loc_id, const char *src_name, hid_t dst_loc_id,
     /* Move the link through the VOL */
     if((ret_value = H5VL_link_move(obj1, loc_params1, obj2, loc_params2, 
                                    (vol_plugin1!=NULL ? vol_plugin1 : vol_plugin2), 
-                                   TRUE, lcpl_id, lapl_id, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+                                   TRUE, lcpl_id, lapl_id, H5AC_dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to create link")
 done:
     FUNC_LEAVE_API(ret_value)
@@ -498,7 +498,7 @@ H5Lcreate_soft(const char *link_target,
 
     /* Create the link through the VOL */
     if((ret_value = H5VL_link_create(H5VL_LINK_CREATE_SOFT, obj, loc_params, vol_plugin,
-                                     lcpl_id, lapl_id, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+                                     lcpl_id, lapl_id, H5AC_dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to create link")
 
 done:
@@ -601,7 +601,7 @@ H5Lcreate_hard(hid_t cur_loc_id, const char *cur_name,
     /* Create the link through the VOL */
     if((ret_value = H5VL_link_create(H5VL_LINK_CREATE_HARD, obj2, loc_params2, 
                                      (vol_plugin1!=NULL ? vol_plugin1 : vol_plugin2),
-                                     lcpl_id, lapl_id, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+                                     lcpl_id, lapl_id, H5AC_dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to create link")
 
 done:
@@ -686,7 +686,7 @@ H5Lcreate_ud(hid_t link_loc_id, const char *link_name, H5L_type_t link_type,
 
     /* Create the link through the VOL */
     if((ret_value = H5VL_link_create(H5VL_LINK_CREATE_UD, obj, loc_params, vol_plugin,
-                                     lcpl_id, lapl_id, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+                                     lcpl_id, lapl_id, H5AC_dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to create link")
 
 done:
@@ -739,7 +739,7 @@ H5Ldelete(hid_t loc_id, const char *name, hid_t lapl_id)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
 
     /* Delete the link through the VOL */
-    if((ret_value = H5VL_link_remove(obj, loc_params, vol_plugin, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+    if((ret_value = H5VL_link_remove(obj, loc_params, vol_plugin, H5AC_dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to create link")
 
 done:
@@ -807,7 +807,7 @@ H5Ldelete_by_idx(hid_t loc_id, const char *group_name,
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
 
     /* Delete the link through the VOL */
-    if((ret_value = H5VL_link_remove(obj, loc_params, vol_plugin, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+    if((ret_value = H5VL_link_remove(obj, loc_params, vol_plugin, H5AC_dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to create link")
 
 done:
@@ -869,7 +869,7 @@ H5Lget_val(hid_t loc_id, const char *name, void *buf/*out*/, size_t size,
 
     /* Get the link info through the VOL */
     if((ret_value = H5VL_link_get(obj, loc_params, vol_plugin, H5VL_LINK_GET_VAL, 
-                                  H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, buf, size)) < 0)
+                                  H5AC_dxpl_id, H5_EVENT_STACK_NULL, buf, size)) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get link value")
 
 done:
@@ -939,7 +939,7 @@ H5Lget_val_by_idx(hid_t loc_id, const char *group_name, H5_index_t idx_type,
 
     /* Get the link info through the VOL */
     if((ret_value = H5VL_link_get(obj, loc_params, vol_plugin, H5VL_LINK_GET_VAL, 
-                                  H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, buf, size)) < 0)
+                                  H5AC_dxpl_id, H5_EVENT_STACK_NULL, buf, size)) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get link value")
 
 done:
@@ -993,7 +993,7 @@ H5Lexists(hid_t loc_id, const char *name, hid_t lapl_id)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
 
     /* check link existence through the VOL */
-    if(H5VL_link_get(obj, loc_params, vol_plugin, H5VL_LINK_EXISTS, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, &ret_value) < 0)
+    if(H5VL_link_get(obj, loc_params, vol_plugin, H5VL_LINK_EXISTS, H5AC_dxpl_id, H5_EVENT_STACK_NULL, &ret_value) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get link info")
 
 done:
@@ -1049,7 +1049,7 @@ H5Lget_info(hid_t loc_id, const char *name, H5L_info_t *linfo /*out*/,
 
     /* Get the link info through the VOL */
     if((ret_value = H5VL_link_get(obj, loc_params, vol_plugin, H5VL_LINK_GET_INFO, 
-                                  H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, linfo)) < 0)
+                                  H5AC_dxpl_id, H5_EVENT_STACK_NULL, linfo)) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get group info")
 
 done:
@@ -1114,7 +1114,7 @@ H5Lget_info_by_idx(hid_t loc_id, const char *group_name,
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
 
     /* Get the link info through the VOL */
-    if((ret_value = H5VL_link_get(obj, loc_params, vol_plugin, H5VL_LINK_GET_INFO, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, 
+    if((ret_value = H5VL_link_get(obj, loc_params, vol_plugin, H5VL_LINK_GET_INFO, H5AC_dxpl_id, H5_EVENT_STACK_NULL, 
                                   linfo)) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get group info")
 
@@ -1310,7 +1310,7 @@ H5Lget_name_by_idx(hid_t loc_id, const char *group_name,
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
 
     /* Get the link info through the VOL */
-    if((H5VL_link_get(obj, loc_params, vol_plugin, H5VL_LINK_GET_NAME, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, 
+    if((H5VL_link_get(obj, loc_params, vol_plugin, H5VL_LINK_GET_NAME, H5AC_dxpl_id, H5_EVENT_STACK_NULL, 
                       name, size, &ret_value)) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get link name")
 
@@ -1377,7 +1377,7 @@ H5Literate(hid_t id, H5_index_t idx_type, H5_iter_order_t order,
 
     /* iterate over the links through the VOL */
     if((ret_value = H5VL_link_iterate(obj, loc_params, vol_plugin, FALSE, idx_type, order, idx_p,
-                                      op, op_data, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+                                      op, op_data, H5AC_dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_BADITER, FAIL, "link iteration failed")
 
 done:
@@ -1450,7 +1450,7 @@ H5Literate_by_name(hid_t loc_id, const char *group_name,
 
     /* iterate over the links through the VOL */
     if((ret_value = H5VL_link_iterate(obj, loc_params, vol_plugin, FALSE, idx_type, order, idx_p,
-                                      op, op_data, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+                                      op, op_data, H5AC_dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_BADITER, FAIL, "link iteration failed")
 
 done:
@@ -1523,7 +1523,7 @@ H5Lvisit(hid_t grp_id, H5_index_t idx_type, H5_iter_order_t order,
 
     /* iterate over the links through the VOL */
     if((ret_value = H5VL_link_iterate(obj, loc_params, vol_plugin, TRUE, idx_type, order, NULL,
-                                      op, op_data, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+                                      op, op_data, H5AC_dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_BADITER, FAIL, "link iteration failed")
 
 done:
@@ -1601,7 +1601,7 @@ H5Lvisit_by_name(hid_t loc_id, const char *group_name, H5_index_t idx_type,
 
     /* visit the links through the VOL */
     if((ret_value = H5VL_link_iterate(obj, loc_params, vol_plugin, TRUE, idx_type, order, NULL,
-                                      op, op_data, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+                                      op, op_data, H5AC_dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_BADITER, FAIL, "link iteration failed")
 
 done:
diff --git a/src/H5Lexternal.c b/src/H5Lexternal.c
index 847731b..6ac1bdf 100644
--- a/src/H5Lexternal.c
+++ b/src/H5Lexternal.c
@@ -630,7 +630,7 @@ H5Lcreate_external(const char *file_name, const char *obj_name,
 
     /* Create the link through the VOL */
     if((ret_value = H5VL_link_create(H5VL_LINK_CREATE_UD, obj, loc_params, vol_plugin,
-                                     lcpl_id, lapl_id, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+                                     lcpl_id, lapl_id, H5AC_dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to create link")
 
 done:
diff --git a/src/H5O.c b/src/H5O.c
index 5794e6f..61e957d 100644
--- a/src/H5O.c
+++ b/src/H5O.c
@@ -255,7 +255,7 @@ H5Oopen(hid_t loc_id, const char *name, hid_t lapl_id)
 
     /* Open the object through the VOL */
     if(NULL == (opened_obj = H5VL_object_open(obj, loc_params, vol_plugin, &opened_type, 
-                                              H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)))
+                                              H5AC_dxpl_id, H5_EVENT_STACK_NULL)))
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to open object")
 
     if ((ret_value = H5VL_object_register(opened_obj, opened_type, vol_plugin, TRUE)) < 0)
@@ -332,7 +332,7 @@ H5Oopen_by_idx(hid_t loc_id, const char *group_name, H5_index_t idx_type,
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
 
     /* Open the object through the VOL */
-    if(NULL == (opened_obj = H5VL_object_open(obj, loc_params, vol_plugin, &opened_type, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)))
+    if(NULL == (opened_obj = H5VL_object_open(obj, loc_params, vol_plugin, &opened_type, H5AC_dxpl_id, H5_EVENT_STACK_NULL)))
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to open object")
 
     if ((ret_value = H5VL_object_register(opened_obj, opened_type, vol_plugin, TRUE)) < 0)
@@ -403,7 +403,7 @@ H5Oopen_by_addr(hid_t loc_id, haddr_t addr)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
 
     /* Open the object through the VOL */
-    if(NULL == (opened_obj = H5VL_object_open(obj, loc_params, vol_plugin, &opened_type, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)))
+    if(NULL == (opened_obj = H5VL_object_open(obj, loc_params, vol_plugin, &opened_type, H5AC_dxpl_id, H5_EVENT_STACK_NULL)))
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to open object")
 
     if ((ret_value = H5VL_object_register(opened_obj, opened_type, vol_plugin, TRUE)) < 0)
@@ -511,7 +511,7 @@ H5Olink(hid_t obj_id, hid_t new_loc_id, const char *new_name, hid_t lcpl_id,
     /* Create the link through the VOL */
     if((ret_value = H5VL_link_create(H5VL_LINK_CREATE_HARD, obj2, loc_params2, 
                                      (vol_plugin1!=NULL ? vol_plugin1 : vol_plugin2),
-                                     lcpl_id, lapl_id, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+                                     lcpl_id, lapl_id, H5AC_dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to create link")
 
 done:
@@ -562,7 +562,7 @@ H5Oincr_refcount(hid_t object_id)
 
     /* change the ref count through the VOL */
     if(H5VL_object_misc(obj, loc_params, vol_plugin, H5VL_OBJECT_CHANGE_REF_COUNT, 
-                        H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, 1) < 0)
+                        H5AC_dxpl_id, H5_EVENT_STACK_NULL, 1) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_LINKCOUNT, FAIL, "modifying object link count failed")
 
 done:
@@ -612,7 +612,7 @@ H5Odecr_refcount(hid_t object_id)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
 
     /* change the ref count through the VOL */
-    if(H5VL_object_misc(obj, loc_params, vol_plugin, H5VL_OBJECT_CHANGE_REF_COUNT, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, -1) < 0)
+    if(H5VL_object_misc(obj, loc_params, vol_plugin, H5VL_OBJECT_CHANGE_REF_COUNT, H5AC_dxpl_id, H5_EVENT_STACK_NULL, -1) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_LINKCOUNT, FAIL, "modifying object link count failed")
 
 done:
@@ -666,7 +666,7 @@ H5Oexists_by_name(hid_t loc_id, const char *name, hid_t lapl_id)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
 
     /* change the ref count through the VOL */
-    if(H5VL_object_get(obj, loc_params, vol_plugin, H5VL_OBJECT_EXISTS, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, &ret_value) < 0)
+    if(H5VL_object_get(obj, loc_params, vol_plugin, H5VL_OBJECT_EXISTS, H5AC_dxpl_id, H5_EVENT_STACK_NULL, &ret_value) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, FAIL, "unable to determine if '%s' exists", name)
 
 done:
@@ -714,7 +714,7 @@ H5Oget_info(hid_t loc_id, H5O_info_t *oinfo)
 
     /* Get the group info through the VOL using the location token */
     if((ret_value = H5VL_object_get(obj, loc_params, vol_plugin, H5VL_OBJECT_GET_INFO, 
-                                    H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, oinfo)) < 0)
+                                    H5AC_dxpl_id, H5_EVENT_STACK_NULL, oinfo)) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get group info")
 
 done:
@@ -772,7 +772,7 @@ H5Oget_info_by_name(hid_t loc_id, const char *name, H5O_info_t *oinfo, hid_t lap
 
     /* Get the group info through the VOL using the location token */
     if((ret_value = H5VL_object_get(obj, loc_params, vol_plugin, H5VL_OBJECT_GET_INFO, 
-                                    H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, oinfo)) < 0)
+                                    H5AC_dxpl_id, H5_EVENT_STACK_NULL, oinfo)) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get group info")
 
 done:
@@ -839,7 +839,7 @@ H5Oget_info_by_idx(hid_t loc_id, const char *group_name, H5_index_t idx_type,
 
     /* Get the group info through the VOL using the location token */
     if((ret_value = H5VL_object_get(obj, loc_params, vol_plugin, H5VL_OBJECT_GET_INFO, 
-                                    H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, oinfo)) < 0)
+                                    H5AC_dxpl_id, H5_EVENT_STACK_NULL, oinfo)) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get group info")
 
 done:
@@ -886,7 +886,7 @@ H5Oset_comment(hid_t obj_id, const char *comment)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
 
     /* set comment on object through the VOL */
-    if(H5VL_object_misc(obj, loc_params, vol_plugin, H5VL_OBJECT_SET_COMMENT, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, comment) < 0)
+    if(H5VL_object_misc(obj, loc_params, vol_plugin, H5VL_OBJECT_SET_COMMENT, H5AC_dxpl_id, H5_EVENT_STACK_NULL, comment) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to set comment value")
 
 done:
@@ -945,7 +945,7 @@ H5Oset_comment_by_name(hid_t loc_id, const char *name, const char *comment,
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
 
     /* set comment on object through the VOL */
-    if(H5VL_object_misc(obj, loc_params, vol_plugin, H5VL_OBJECT_SET_COMMENT, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, comment) < 0)
+    if(H5VL_object_misc(obj, loc_params, vol_plugin, H5VL_OBJECT_SET_COMMENT, H5AC_dxpl_id, H5_EVENT_STACK_NULL, comment) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to set comment value")
 
 done:
@@ -990,7 +990,7 @@ H5Oget_comment(hid_t loc_id, char *comment, size_t bufsize)
     if (NULL == (vol_plugin = (H5VL_t *)H5I_get_aux(loc_id)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
 
-    if(H5VL_object_get(obj, loc_params, vol_plugin, H5VL_OBJECT_GET_COMMENT, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, 
+    if(H5VL_object_get(obj, loc_params, vol_plugin, H5VL_OBJECT_GET_COMMENT, H5AC_dxpl_id, H5_EVENT_STACK_NULL, 
                        comment, bufsize, &ret_value) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get object comment")
 
@@ -1048,7 +1048,7 @@ H5Oget_comment_by_name(hid_t loc_id, const char *name, char *comment, size_t buf
     if (NULL == (vol_plugin = (H5VL_t *)H5I_get_aux(loc_id)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
 
-    if(H5VL_object_get(obj, loc_params, vol_plugin, H5VL_OBJECT_GET_COMMENT, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, 
+    if(H5VL_object_get(obj, loc_params, vol_plugin, H5VL_OBJECT_GET_COMMENT, H5AC_dxpl_id, H5_EVENT_STACK_NULL, 
                        comment, bufsize, &ret_value) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get object info")
 
@@ -1121,7 +1121,7 @@ H5Ovisit(hid_t obj_id, H5_index_t idx_type, H5_iter_order_t order,
 
     /* iterate over the objects through the VOL */
     if((ret_value = H5VL_object_visit(obj, loc_params, vol_plugin, idx_type, order, op, op_data, 
-                                      H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+                                      H5AC_dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_BADITER, FAIL, "link iteration failed")
 
 done:
@@ -1203,7 +1203,7 @@ H5Ovisit_by_name(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
 
     /* iterate over the objects through the VOL */
     if((ret_value = H5VL_object_visit(obj, loc_params, vol_plugin, idx_type, order, op, 
-                                      op_data, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+                                      op_data, H5AC_dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_BADITER, FAIL, "link iteration failed")
 
 done:
@@ -1268,7 +1268,7 @@ H5Oclose(hid_t object_id)
 
 #if 0
     /* Close the object through the VOL */
-    if(H5VL_object_close(object_id, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL) < 0)
+    if(H5VL_object_close(object_id, H5AC_dxpl_id, H5_EVENT_STACK_NULL) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_CANTRELEASE, FAIL, "unable to close object")
 #endif
 
diff --git a/src/H5Ocopy.c b/src/H5Ocopy.c
index 543a9c1..7d7d5eb 100644
--- a/src/H5Ocopy.c
+++ b/src/H5Ocopy.c
@@ -254,7 +254,7 @@ H5Ocopy(hid_t src_loc_id, const char *src_name, hid_t dst_loc_id,
     /* Open the object through the VOL */
     if((ret_value = H5VL_object_copy(obj1, loc_params1, vol_plugin1, src_name, 
                                      obj2, loc_params2, vol_plugin2, dst_name, 
-                                     ocpypl_id, lcpl_id, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+                                     ocpypl_id, lcpl_id, H5AC_dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to open object")
 done:
     FUNC_LEAVE_API(ret_value)
diff --git a/src/H5R.c b/src/H5R.c
index 5d0c8cf..d6780da 100644
--- a/src/H5R.c
+++ b/src/H5R.c
@@ -373,7 +373,7 @@ H5Rcreate(void *ref, hid_t loc_id, const char *name, H5R_type_t ref_type, hid_t
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
 
     /* create the ref through the VOL */
-    if(ret_value = H5VL_object_misc(obj, loc_params, vol_plugin, H5VL_REF_CREATE, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, 
+    if(ret_value = H5VL_object_misc(obj, loc_params, vol_plugin, H5VL_REF_CREATE, H5AC_dxpl_id, H5_EVENT_STACK_NULL, 
                                     ref, name, ref_type, space_id) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_LINKCOUNT, FAIL, "modifying object link count failed")
 
@@ -601,7 +601,7 @@ H5Rdereference2(hid_t obj_id, hid_t oapl_id, H5R_type_t ref_type, const void *_r
     loc_params.obj_type = H5I_get_type(obj_id);
 
     /* Open the object through the VOL */
-    if(NULL == (opened_obj = H5VL_object_open(obj, loc_params, vol_plugin, &opened_type, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)))
+    if(NULL == (opened_obj = H5VL_object_open(obj, loc_params, vol_plugin, &opened_type, H5AC_dxpl_id, H5_EVENT_STACK_NULL)))
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to open object")
 
     /* Get an atom for the object */
@@ -733,7 +733,7 @@ H5Rget_region(hid_t id, H5R_type_t ref_type, const void *ref)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
 
     /* Get the space id through the VOL */
-    if(H5VL_object_get(obj, loc_params, vol_plugin, H5VL_REF_GET_REGION, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, 
+    if(H5VL_object_get(obj, loc_params, vol_plugin, H5VL_REF_GET_REGION, H5AC_dxpl_id, H5_EVENT_STACK_NULL, 
                        &ret_value, ref_type, ref) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get group info")
 
@@ -881,7 +881,7 @@ H5Rget_obj_type2(hid_t id, H5R_type_t ref_type, const void *ref,
 
     /* get the object type through the VOL */
     if((ret_value = H5VL_object_get(obj, loc_params, vol_plugin, H5VL_REF_GET_TYPE, 
-                                    H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, obj_type, ref_type, ref)) < 0)
+                                    H5AC_dxpl_id, H5_EVENT_STACK_NULL, obj_type, ref_type, ref)) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get group info")
 
 done:
@@ -1048,7 +1048,7 @@ H5Rget_name(hid_t id, H5R_type_t ref_type, const void *_ref, char *name,
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
 
     /* get the object type through the VOL */
-    if(H5VL_object_get(obj, loc_params, vol_plugin, H5VL_REF_GET_NAME, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, 
+    if(H5VL_object_get(obj, loc_params, vol_plugin, H5VL_REF_GET_NAME, H5AC_dxpl_id, H5_EVENT_STACK_NULL, 
                        &ret_value, name, size, ref_type, _ref) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get group info")
 done:
diff --git a/src/H5Rdeprec.c b/src/H5Rdeprec.c
index c2aa6ea..86dbca7 100644
--- a/src/H5Rdeprec.c
+++ b/src/H5Rdeprec.c
@@ -161,7 +161,7 @@ H5Rget_obj_type1(hid_t id, H5R_type_t ref_type, const void *ref)
 
     /* get the object type through the VOL */
     if((ret_value = H5VL_object_get(obj, loc_params, vol_plugin, H5VL_REF_GET_TYPE,
-                                    H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, &obj_type, ref_type, ref)) < 0)
+                                    H5AC_dxpl_id, H5_EVENT_STACK_NULL, &obj_type, ref_type, ref)) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get group info")
 
     /* Set return value */
@@ -227,7 +227,7 @@ H5Rdereference1(hid_t obj_id, H5R_type_t ref_type, const void *_ref)
     loc_params.obj_type = H5I_get_type(obj_id);
 
     /* Open the object through the VOL */
-    if(NULL == (opened_obj = H5VL_object_open(obj, loc_params, vol_plugin, &opened_type, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)))
+    if(NULL == (opened_obj = H5VL_object_open(obj, loc_params, vol_plugin, &opened_type, H5AC_dxpl_id, H5_EVENT_STACK_NULL)))
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to open object")
 
     /* Get an atom for the object */
diff --git a/src/H5Tcommit.c b/src/H5Tcommit.c
index 6d80bac..a801737 100644
--- a/src/H5Tcommit.c
+++ b/src/H5Tcommit.c
@@ -175,7 +175,7 @@ H5Tcommit2(hid_t loc_id, const char *name, hid_t type_id, hid_t lcpl_id,
 
     /* commit the datatype through the VOL */
     if (NULL == (dt = H5VL_datatype_commit(obj, loc_params, vol_plugin, name, type_id, lcpl_id, 
-                                           tcpl_id, tapl_id, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)))
+                                           tcpl_id, tapl_id, H5AC_dxpl_id, H5_EVENT_STACK_NULL)))
         HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to commit datatype")
 
     /* attach the vol object created using the commit call to the 
@@ -336,7 +336,7 @@ H5Tcommit_anon(hid_t loc_id, hid_t type_id, hid_t tcpl_id, hid_t tapl_id)
 
     /* commite the datatype through the VOL */
     if (NULL == (dt = H5VL_datatype_commit(obj, loc_params, vol_plugin, NULL, type_id, H5P_DEFAULT, 
-                                           tcpl_id, tapl_id, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)))
+                                           tcpl_id, tapl_id, H5AC_dxpl_id, H5_EVENT_STACK_NULL)))
         HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to commit datatype")
 
     /* attach the vol object created using the commit call to the 
@@ -625,7 +625,7 @@ H5Topen2(hid_t loc_id, const char *name, hid_t tapl_id)
 
     /* Create the datatype through the VOL */
     if(NULL == (dt = H5VL_datatype_open(obj, loc_params, vol_plugin, name, tapl_id, 
-                                        H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)))
+                                        H5AC_dxpl_id, H5_EVENT_STACK_NULL)))
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to open datatype")
 
     /* Get an atom for the datatype */
@@ -634,7 +634,7 @@ H5Topen2(hid_t loc_id, const char *name, hid_t tapl_id)
 
 done:
     if (ret_value < 0 && dt)
-        if(H5VL_datatype_close (dt, vol_plugin, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL) < 0)
+        if(H5VL_datatype_close (dt, vol_plugin, H5AC_dxpl_id, H5_EVENT_STACK_NULL) < 0)
             HDONE_ERROR(H5E_SYM, H5E_CLOSEERROR, FAIL, "unable to release dataset")
     FUNC_LEAVE_API(ret_value)
 } /* end H5Topen2() */
@@ -696,7 +696,7 @@ H5Tget_create_plist(hid_t dtype_id)
 
         /* get the rest of the plist through the VOL */
         if(H5VL_datatype_get(type, vol_plugin, H5VL_DATATYPE_GET_TCPL, 
-                             H5AC_dxpl_id, H5_EVENT_QUEUE_NULL, new_tcpl_id) < 0)
+                             H5AC_dxpl_id, H5_EVENT_STACK_NULL, new_tcpl_id) < 0)
             HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get datatype")
     } /* end if */
 
@@ -969,7 +969,7 @@ H5VL_create_datatype(void *dt_obj, H5VL_t *vol_plugin, hbool_t app_ref)
 
     /* get required buf size for encoding the datatype */
     if((nalloc = H5VL_datatype_get_binary(dt_obj, vol_plugin, NULL, 0, 
-                                          H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+                                          H5AC_dxpl_id, H5_EVENT_STACK_NULL)) < 0)
         HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to get datatype size")
 
     /* allocate buffer to store binary description of the datatype */
@@ -978,7 +978,7 @@ H5VL_create_datatype(void *dt_obj, H5VL_t *vol_plugin, hbool_t app_ref)
 
     /* get binary description of the datatype */
     if((nalloc = H5VL_datatype_get_binary(dt_obj, vol_plugin, buf, (size_t) nalloc, 
-                                          H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+                                          H5AC_dxpl_id, H5_EVENT_STACK_NULL)) < 0)
         HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to get datatype size")
 
     if(NULL == (dt = H5T_decode(buf)))
@@ -1020,7 +1020,7 @@ H5T_close_datatype(void *type, H5VL_t *vol_plugin)
 
     /* Close the datatype through the VOL*/
     if (NULL != dt->vol_obj)
-        if((ret_value = H5VL_datatype_close(dt->vol_obj, vol_plugin, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+        if((ret_value = H5VL_datatype_close(dt->vol_obj, vol_plugin, H5AC_dxpl_id, H5_EVENT_STACK_NULL)) < 0)
             HGOTO_ERROR(H5E_DATATYPE, H5E_CLOSEERROR, FAIL, "unable to close datatype")
 
 done:
diff --git a/src/H5Tdeprec.c b/src/H5Tdeprec.c
index ff54e5a..267852b 100644
--- a/src/H5Tdeprec.c
+++ b/src/H5Tdeprec.c
@@ -156,7 +156,7 @@ H5Tcommit1(hid_t loc_id, const char *name, hid_t type_id)
     /* commit the datatype through the VOL */
     if (NULL == (dt = H5VL_datatype_commit(obj, loc_params, vol_plugin, name, type_id, 
                                            H5P_LINK_CREATE_DEFAULT, H5P_DATATYPE_CREATE_DEFAULT, 
-                                           H5P_DATATYPE_ACCESS_DEFAULT, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)))
+                                           H5P_DATATYPE_ACCESS_DEFAULT, H5AC_dxpl_id, H5_EVENT_STACK_NULL)))
         HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to commit datatype")
 
     /* attach the vol object created using the commit call to the 
@@ -217,7 +217,7 @@ H5Topen1(hid_t loc_id, const char *name)
 
     /* Create the datatype through the VOL */
     if(NULL == (dt = H5VL_datatype_open(obj, loc_params, vol_plugin, name, 
-                                        H5P_DATATYPE_ACCESS_DEFAULT, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL)))
+                                        H5P_DATATYPE_ACCESS_DEFAULT, H5AC_dxpl_id, H5_EVENT_STACK_NULL)))
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to open datatype")
 
     /* Get an atom for the datatype */
@@ -226,7 +226,7 @@ H5Topen1(hid_t loc_id, const char *name)
 
 done:
     if (ret_value < 0 && dt)
-        if(H5VL_datatype_close (dt, vol_plugin, H5AC_dxpl_id, H5_EVENT_QUEUE_NULL) < 0)
+        if(H5VL_datatype_close (dt, vol_plugin, H5AC_dxpl_id, H5_EVENT_STACK_NULL) < 0)
             HDONE_ERROR(H5E_SYM, H5E_CLOSEERROR, FAIL, "unable to release dataset")
     FUNC_LEAVE_API(ret_value)
 } /* end H5Topen1() */
diff --git a/src/H5VL.c b/src/H5VL.c
index 46eb801..971dd4b 100644
--- a/src/H5VL.c
+++ b/src/H5VL.c
@@ -453,7 +453,7 @@ H5VLattr_create(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, con
 
     if (NULL == obj || NULL == vol_plugin || NULL == vol_plugin->cls)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, NULL, "invalid object/VOL class pointer")
-    if(NULL == (ret_value = H5VL_attr_create(obj, loc_params, vol_plugin, name, acpl_id, aapl_id, dxpl_id, H5_EVENT_QUEUE_NULL)))
+    if(NULL == (ret_value = H5VL_attr_create(obj, loc_params, vol_plugin, name, acpl_id, aapl_id, dxpl_id, H5_EVENT_STACK_NULL)))
 	HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, NULL, "unable to create attribute")
 
 done:
@@ -485,7 +485,7 @@ H5VLattr_open(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, const
 
     if (NULL == obj || NULL == vol_plugin || NULL == vol_plugin->cls)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, NULL, "invalid object/VOL class pointer")
-    if(NULL == (ret_value = H5VL_attr_open(obj, loc_params, vol_plugin, name, aapl_id, dxpl_id, H5_EVENT_QUEUE_NULL)))
+    if(NULL == (ret_value = H5VL_attr_open(obj, loc_params, vol_plugin, name, aapl_id, dxpl_id, H5_EVENT_STACK_NULL)))
 	HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, NULL, "unable to open attribute")
 
 done:
@@ -515,7 +515,7 @@ herr_t H5VLattr_read(void *attr, H5VL_t *vol_plugin, hid_t mem_type_id, void *bu
 
     if (NULL == attr || NULL == vol_plugin || NULL == vol_plugin->cls)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid object/VOL class pointer")
-    if((ret_value = H5VL_attr_read(attr, vol_plugin, mem_type_id, buf, dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+    if((ret_value = H5VL_attr_read(attr, vol_plugin, mem_type_id, buf, dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to read attribute")
 
 done:
@@ -545,7 +545,7 @@ herr_t H5VLattr_write(void *attr, H5VL_t *vol_plugin, hid_t mem_type_id, const v
 
     if (NULL == attr || NULL == vol_plugin || NULL == vol_plugin->cls)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid object/VOL class pointer")
-    if((ret_value = H5VL_attr_write(attr, vol_plugin, mem_type_id, buf, dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+    if((ret_value = H5VL_attr_write(attr, vol_plugin, mem_type_id, buf, dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to write attribute")
 
 done:
@@ -577,7 +577,7 @@ herr_t H5VLattr_iterate(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plu
     if(NULL == obj || NULL == vol_plugin || NULL == vol_plugin->cls)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid object/VOL class pointer")
     if((ret_value = H5VL_attr_iterate(obj, loc_params, vol_plugin, idx_type, order, n,
-                                      op, op_data, dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+                                      op, op_data, dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "Attr iteration failed")
 
 done:
@@ -617,7 +617,7 @@ H5VLattr_get(void *obj, H5VL_t *vol_plugin, H5VL_attr_get_t get_type, hid_t dxpl
                 char    *attr_name      = va_arg (arguments, char *);
                 htri_t	*ret       = va_arg (arguments, htri_t *);
 
-                if((ret_value = H5VL_attr_get(obj, vol_plugin, get_type, dxpl_id, H5_EVENT_QUEUE_NULL, 
+                if((ret_value = H5VL_attr_get(obj, vol_plugin, get_type, dxpl_id, H5_EVENT_STACK_NULL, 
                                               loc_params, attr_name, ret)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to get attribute information")
                 break;
@@ -627,7 +627,7 @@ H5VLattr_get(void *obj, H5VL_t *vol_plugin, H5VL_attr_get_t get_type, hid_t dxpl
             {
                 hid_t	*ret_id = va_arg (arguments, hid_t *);
 
-                if((ret_value = H5VL_attr_get(obj, vol_plugin, get_type, dxpl_id, H5_EVENT_QUEUE_NULL, ret_id)) < 0)
+                if((ret_value = H5VL_attr_get(obj, vol_plugin, get_type, dxpl_id, H5_EVENT_STACK_NULL, ret_id)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to get attribute information")
                 break;
             }
@@ -636,7 +636,7 @@ H5VLattr_get(void *obj, H5VL_t *vol_plugin, H5VL_attr_get_t get_type, hid_t dxpl
             {
                 hid_t	*ret_id = va_arg (arguments, hid_t *);
 
-                if((ret_value = H5VL_attr_get(obj, vol_plugin, get_type, dxpl_id, H5_EVENT_QUEUE_NULL, ret_id)) < 0)
+                if((ret_value = H5VL_attr_get(obj, vol_plugin, get_type, dxpl_id, H5_EVENT_STACK_NULL, ret_id)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to get attribute information")
                 break;
             }
@@ -645,7 +645,7 @@ H5VLattr_get(void *obj, H5VL_t *vol_plugin, H5VL_attr_get_t get_type, hid_t dxpl
             {
                 hid_t	*ret_id = va_arg (arguments, hid_t *);
 
-                if((ret_value = H5VL_attr_get(obj, vol_plugin, get_type, dxpl_id, H5_EVENT_QUEUE_NULL, ret_id)) < 0)
+                if((ret_value = H5VL_attr_get(obj, vol_plugin, get_type, dxpl_id, H5_EVENT_STACK_NULL, ret_id)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to get attribute information")
                 break;
             }
@@ -657,7 +657,7 @@ H5VLattr_get(void *obj, H5VL_t *vol_plugin, H5VL_attr_get_t get_type, hid_t dxpl
                 char    *buf = va_arg (arguments, char *);
                 ssize_t	*ret_val = va_arg (arguments, ssize_t *);
 
-                if((ret_value = H5VL_attr_get(obj, vol_plugin, get_type, dxpl_id, H5_EVENT_QUEUE_NULL, 
+                if((ret_value = H5VL_attr_get(obj, vol_plugin, get_type, dxpl_id, H5_EVENT_STACK_NULL, 
                                               loc_params, buf_size, buf, ret_val)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to get attribute information")
                 break;
@@ -669,17 +669,17 @@ H5VLattr_get(void *obj, H5VL_t *vol_plugin, H5VL_attr_get_t get_type, hid_t dxpl
                 H5A_info_t   *ainfo = va_arg (arguments, H5A_info_t *);
 
                 if(H5VL_OBJECT_BY_SELF == loc_params.type) {
-                    if((ret_value = H5VL_attr_get(obj, vol_plugin, get_type, dxpl_id, H5_EVENT_QUEUE_NULL, loc_params, ainfo)) < 0)
+                    if((ret_value = H5VL_attr_get(obj, vol_plugin, get_type, dxpl_id, H5_EVENT_STACK_NULL, loc_params, ainfo)) < 0)
                         HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to get attribute information")
                 }
                 else if(H5VL_OBJECT_BY_NAME == loc_params.type) {
                     char *attr_name = va_arg (arguments, char *);
 
-                    if((ret_value = H5VL_attr_get(obj, vol_plugin, get_type, dxpl_id, H5_EVENT_QUEUE_NULL, loc_params, ainfo, attr_name)) < 0)
+                    if((ret_value = H5VL_attr_get(obj, vol_plugin, get_type, dxpl_id, H5_EVENT_STACK_NULL, loc_params, ainfo, attr_name)) < 0)
                         HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to get attribute information")
                 }
                 else if(H5VL_OBJECT_BY_IDX == loc_params.type) {
-                    if((ret_value = H5VL_attr_get(obj, vol_plugin, get_type, dxpl_id, H5_EVENT_QUEUE_NULL, loc_params, ainfo)) < 0)
+                    if((ret_value = H5VL_attr_get(obj, vol_plugin, get_type, dxpl_id, H5_EVENT_STACK_NULL, loc_params, ainfo)) < 0)
                         HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to get attribute information")
                 }
                 else
@@ -690,7 +690,7 @@ H5VLattr_get(void *obj, H5VL_t *vol_plugin, H5VL_attr_get_t get_type, hid_t dxpl
         case H5VL_ATTR_GET_STORAGE_SIZE:
             {
                 hsize_t *ret = va_arg (arguments, hsize_t *);
-                if((ret_value = H5VL_attr_get(obj, vol_plugin, get_type, dxpl_id, H5_EVENT_QUEUE_NULL, ret)) < 0)
+                if((ret_value = H5VL_attr_get(obj, vol_plugin, get_type, dxpl_id, H5_EVENT_STACK_NULL, ret)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to get attribute information")
                 break;
             }
@@ -727,7 +727,7 @@ H5VLattr_remove(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin,
 
     if (NULL == obj || NULL == vol_plugin || NULL == vol_plugin->cls)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid object/VOL class pointer")
-    if((ret_value = H5VL_attr_remove(obj, loc_params, vol_plugin, attr_name, dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+    if((ret_value = H5VL_attr_remove(obj, loc_params, vol_plugin, attr_name, dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to remove attribute")
 
 done:
@@ -758,7 +758,7 @@ H5VLattr_close(void *attr, H5VL_t *vol_plugin, hid_t dxpl_id, void UNUSED **req)
 
     if (NULL == attr || NULL == vol_plugin || NULL == vol_plugin->cls)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid object/VOL class pointer")
-    if((ret_value = H5VL_attr_close(attr, vol_plugin, dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+    if((ret_value = H5VL_attr_close(attr, vol_plugin, dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_VOL, H5E_CANTRELEASE, FAIL, "unable to close attribute")
 
 done:
@@ -791,7 +791,7 @@ H5VLdatatype_commit(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin,
     if (NULL == obj || NULL == vol_plugin || NULL == vol_plugin->cls)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, NULL, "invalid object/VOL class pointer")
     if(NULL == (ret_value = H5VL_datatype_commit(obj, loc_params, vol_plugin, name, type_id, 
-                                                 lcpl_id, tcpl_id, tapl_id, dxpl_id, H5_EVENT_QUEUE_NULL)))
+                                                 lcpl_id, tcpl_id, tapl_id, dxpl_id, H5_EVENT_STACK_NULL)))
 	HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, NULL, "unable to commit datatype")
 
 done:
@@ -823,7 +823,7 @@ H5VLdatatype_open(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, c
 
     if (NULL == obj || NULL == vol_plugin || NULL == vol_plugin->cls)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, NULL, "invalid object/VOL class pointer")
-    if(NULL == (ret_value = H5VL_datatype_open(obj, loc_params, vol_plugin, name, tapl_id, dxpl_id, H5_EVENT_QUEUE_NULL)))
+    if(NULL == (ret_value = H5VL_datatype_open(obj, loc_params, vol_plugin, name, tapl_id, dxpl_id, H5_EVENT_STACK_NULL)))
 	HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, NULL, "unable to open datatype")
 
 done:
@@ -854,7 +854,7 @@ H5VLdatatype_get_binary(void *obj, H5VL_t *vol_plugin, unsigned char *buf, size_
 
     if (NULL == obj || NULL == vol_plugin || NULL == vol_plugin->cls)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid object/VOL class pointer")
-    if((ret_value = H5VL_datatype_get_binary(obj, vol_plugin, buf, size, dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+    if((ret_value = H5VL_datatype_get_binary(obj, vol_plugin, buf, size, dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to encode datatype")
 
 done:
@@ -894,7 +894,7 @@ H5VLdatatype_get(void *obj, H5VL_t *vol_plugin, H5VL_datatype_get_t get_type,
                 hid_t *new_tcpl_id = va_arg (arguments, hid_t *);
 
                 if((ret_value = H5VL_datatype_get(obj, vol_plugin, get_type, dxpl_id, 
-                                                  H5_EVENT_QUEUE_NULL, new_tcpl_id)) < 0)
+                                                  H5_EVENT_STACK_NULL, new_tcpl_id)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to get datatype information")
                 break;
             }
@@ -929,7 +929,7 @@ H5VLdatatype_close(void *dt, H5VL_t *vol_plugin, hid_t dxpl_id, void UNUSED **re
 
     if (NULL == dt || NULL == vol_plugin || NULL == vol_plugin->cls)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid object/VOL class pointer")
-    if((ret_value = H5VL_datatype_close(dt, vol_plugin, dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+    if((ret_value = H5VL_datatype_close(dt, vol_plugin, dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_VOL, H5E_CANTRELEASE, FAIL, "unable to close datatype")
 
 done:
@@ -962,7 +962,7 @@ H5VLdataset_create(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin,
     if (NULL == obj || NULL == vol_plugin || NULL == vol_plugin->cls)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, NULL, "invalid object/VOL class pointer")
     if(NULL == (ret_value = H5VL_dataset_create(obj, loc_params, vol_plugin, name, 
-                                                dcpl_id, dapl_id, dxpl_id, H5_EVENT_QUEUE_NULL)))
+                                                dcpl_id, dapl_id, dxpl_id, H5_EVENT_STACK_NULL)))
 	HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, NULL, "unable to create dataset")
 
 done:
@@ -994,7 +994,7 @@ H5VLdataset_open(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, co
 
     if (NULL == obj || NULL == vol_plugin || NULL == vol_plugin->cls)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, NULL, "invalid object/VOL class pointer")
-    if(NULL == (ret_value = H5VL_dataset_open(obj, loc_params, vol_plugin, name, dapl_id, dxpl_id, H5_EVENT_QUEUE_NULL)))
+    if(NULL == (ret_value = H5VL_dataset_open(obj, loc_params, vol_plugin, name, dapl_id, dxpl_id, H5_EVENT_STACK_NULL)))
 	HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, NULL, "unable to open dataset")
 
 done:
@@ -1027,7 +1027,7 @@ H5VLdataset_read(void *dset, H5VL_t *vol_plugin, hid_t mem_type_id, hid_t mem_sp
     if (NULL == dset || NULL == vol_plugin || NULL == vol_plugin->cls)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid object/VOL class pointer")
     if((ret_value = H5VL_dataset_read(dset, vol_plugin, mem_type_id, mem_space_id, file_space_id, 
-                                      plist_id, buf, H5_EVENT_QUEUE_NULL)) < 0)
+                                      plist_id, buf, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to read dataset")
 
 done:
@@ -1060,7 +1060,7 @@ H5VLdataset_write(void *dset, H5VL_t *vol_plugin, hid_t mem_type_id, hid_t mem_s
     if (NULL == dset || NULL == vol_plugin || NULL == vol_plugin->cls)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid object/VOL class pointer")
     if((ret_value = H5VL_dataset_write(dset, vol_plugin, mem_type_id, mem_space_id, file_space_id, 
-                                       plist_id, buf, H5_EVENT_QUEUE_NULL)) < 0)
+                                       plist_id, buf, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to write dataset")
 
 done:
@@ -1091,7 +1091,7 @@ H5VLdataset_set_extent(void *dset, H5VL_t *vol_plugin, const hsize_t size[], hid
 
     if (NULL == dset || NULL == vol_plugin || NULL == vol_plugin->cls)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid object/VOL class pointer")
-    if((ret_value = H5VL_dataset_set_extent(dset, vol_plugin, size, dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+    if((ret_value = H5VL_dataset_set_extent(dset, vol_plugin, size, dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to set extent of dataset")
 
 done:
@@ -1129,7 +1129,7 @@ H5VLdataset_get(void *dset, H5VL_t *vol_plugin, H5VL_dataset_get_t get_type, hid
             {
                 hid_t	*ret_id = va_arg (arguments, hid_t *);
 
-                if((ret_value = H5VL_dataset_get(dset, vol_plugin, get_type, dxpl_id, H5_EVENT_QUEUE_NULL, ret_id)) < 0)
+                if((ret_value = H5VL_dataset_get(dset, vol_plugin, get_type, dxpl_id, H5_EVENT_STACK_NULL, ret_id)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to get dataset information")
                 break;
             }
@@ -1138,7 +1138,7 @@ H5VLdataset_get(void *dset, H5VL_t *vol_plugin, H5VL_dataset_get_t get_type, hid
             {
                 H5D_space_status_t *allocation = va_arg (arguments, H5D_space_status_t *);
 
-                if((ret_value = H5VL_dataset_get(dset, vol_plugin, get_type, dxpl_id, H5_EVENT_QUEUE_NULL, allocation)) < 0)
+                if((ret_value = H5VL_dataset_get(dset, vol_plugin, get_type, dxpl_id, H5_EVENT_STACK_NULL, allocation)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to get dataset information")
                 break;
             }
@@ -1147,7 +1147,7 @@ H5VLdataset_get(void *dset, H5VL_t *vol_plugin, H5VL_dataset_get_t get_type, hid
             {
                 hid_t	*ret_id = va_arg (arguments, hid_t *);
 
-                if((ret_value = H5VL_dataset_get(dset, vol_plugin, get_type, dxpl_id, H5_EVENT_QUEUE_NULL, ret_id)) < 0)
+                if((ret_value = H5VL_dataset_get(dset, vol_plugin, get_type, dxpl_id, H5_EVENT_STACK_NULL, ret_id)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to get dataset information")
                 break;
             }
@@ -1156,7 +1156,7 @@ H5VLdataset_get(void *dset, H5VL_t *vol_plugin, H5VL_dataset_get_t get_type, hid
             {
                 hid_t	*ret_id = va_arg (arguments, hid_t *);
 
-                if((ret_value = H5VL_dataset_get(dset, vol_plugin, get_type, dxpl_id, H5_EVENT_QUEUE_NULL, ret_id)) < 0)
+                if((ret_value = H5VL_dataset_get(dset, vol_plugin, get_type, dxpl_id, H5_EVENT_STACK_NULL, ret_id)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to get dataset information")
                 break;
             }
@@ -1165,7 +1165,7 @@ H5VLdataset_get(void *dset, H5VL_t *vol_plugin, H5VL_dataset_get_t get_type, hid
             {
                 hid_t	*ret_id = va_arg (arguments, hid_t *);
 
-                if((ret_value = H5VL_dataset_get(dset, vol_plugin, get_type, dxpl_id, H5_EVENT_QUEUE_NULL, ret_id)) < 0)
+                if((ret_value = H5VL_dataset_get(dset, vol_plugin, get_type, dxpl_id, H5_EVENT_STACK_NULL, ret_id)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to get dataset information")
                 break;
             }
@@ -1174,7 +1174,7 @@ H5VLdataset_get(void *dset, H5VL_t *vol_plugin, H5VL_dataset_get_t get_type, hid
             {
                 hsize_t *ret = va_arg (arguments, hsize_t *);
 
-                if((ret_value = H5VL_dataset_get(dset, vol_plugin, get_type, dxpl_id, H5_EVENT_QUEUE_NULL, ret)) < 0)
+                if((ret_value = H5VL_dataset_get(dset, vol_plugin, get_type, dxpl_id, H5_EVENT_STACK_NULL, ret)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to get dataset information")
                 break;
             }
@@ -1183,7 +1183,7 @@ H5VLdataset_get(void *dset, H5VL_t *vol_plugin, H5VL_dataset_get_t get_type, hid
             {
                 haddr_t *ret = va_arg (arguments, haddr_t *);
 
-                if((ret_value = H5VL_dataset_get(dset, vol_plugin, get_type, dxpl_id, H5_EVENT_QUEUE_NULL, ret)) < 0)
+                if((ret_value = H5VL_dataset_get(dset, vol_plugin, get_type, dxpl_id, H5_EVENT_STACK_NULL, ret)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to get dataset information")
                 break;
             }
@@ -1219,7 +1219,7 @@ H5VLdataset_close(void *dset, H5VL_t *vol_plugin, hid_t dxpl_id, void UNUSED **r
 
     if (NULL == dset || NULL == vol_plugin || NULL == vol_plugin->cls)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid object/VOL class pointer")
-    if((ret_value = H5VL_dataset_close(dset, vol_plugin, dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+    if((ret_value = H5VL_dataset_close(dset, vol_plugin, dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_VOL, H5E_CANTRELEASE, FAIL, "unable to close dataset")
 
 done:
@@ -1249,7 +1249,7 @@ H5VLfile_create(H5VL_t **vol_plugin, const char *name, unsigned flags, hid_t fcp
 
     FUNC_ENTER_API(NULL)
 
-    if(NULL == (ret_value = H5VL_file_create(vol_plugin, name, flags, fcpl_id, fapl_id, dxpl_id, H5_EVENT_QUEUE_NULL)))
+    if(NULL == (ret_value = H5VL_file_create(vol_plugin, name, flags, fcpl_id, fapl_id, dxpl_id, H5_EVENT_STACK_NULL)))
 	HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, NULL, "unable to create file")
 
 done:
@@ -1278,7 +1278,7 @@ H5VLfile_open(H5VL_t **vol_plugin, const char *name, unsigned flags, hid_t fapl_
 
     FUNC_ENTER_API(NULL)
 
-    if(NULL == (ret_value = H5VL_file_open(vol_plugin, name, flags, fapl_id, dxpl_id, H5_EVENT_QUEUE_NULL)))
+    if(NULL == (ret_value = H5VL_file_open(vol_plugin, name, flags, fapl_id, dxpl_id, H5_EVENT_STACK_NULL)))
 	HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, NULL, "unable to create file")
 
 done:
@@ -1310,7 +1310,7 @@ H5VLfile_flush(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin,
 
     if (NULL == obj || NULL == vol_plugin || NULL == vol_plugin->cls)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid object/VOL class pointer")
-    if((ret_value = H5VL_file_flush(obj, loc_params, vol_plugin, scope, dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+    if((ret_value = H5VL_file_flush(obj, loc_params, vol_plugin, scope, dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to flush file")
 
 done:
@@ -1348,7 +1348,7 @@ H5VLfile_get(void *file, H5VL_t *vol_plugin, H5VL_file_get_t get_type, hid_t dxp
             {
                 hid_t *plist_id = va_arg (arguments, hid_t *);
 
-                if((ret_value = H5VL_file_get(file, vol_plugin, get_type, dxpl_id, H5_EVENT_QUEUE_NULL, plist_id)) < 0)
+                if((ret_value = H5VL_file_get(file, vol_plugin, get_type, dxpl_id, H5_EVENT_STACK_NULL, plist_id)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to get file information")
                 break;
             }
@@ -1357,7 +1357,7 @@ H5VLfile_get(void *file, H5VL_t *vol_plugin, H5VL_file_get_t get_type, hid_t dxp
             {
                 hid_t *plist_id = va_arg (arguments, hid_t *);
 
-                if((ret_value = H5VL_file_get(file, vol_plugin, get_type, dxpl_id, H5_EVENT_QUEUE_NULL, plist_id)) < 0)
+                if((ret_value = H5VL_file_get(file, vol_plugin, get_type, dxpl_id, H5_EVENT_STACK_NULL, plist_id)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to get file information")
                 break;
             }
@@ -1367,7 +1367,7 @@ H5VLfile_get(void *file, H5VL_t *vol_plugin, H5VL_file_get_t get_type, hid_t dxp
                 unsigned types = va_arg (arguments, unsigned);
                 ssize_t *ret = va_arg (arguments, ssize_t *);
 
-                if((ret_value = H5VL_file_get(file, vol_plugin, get_type, dxpl_id, H5_EVENT_QUEUE_NULL, types, ret)) < 0)
+                if((ret_value = H5VL_file_get(file, vol_plugin, get_type, dxpl_id, H5_EVENT_STACK_NULL, types, ret)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to get file information")
                 break;
             }
@@ -1379,7 +1379,7 @@ H5VLfile_get(void *file, H5VL_t *vol_plugin, H5VL_file_get_t get_type, hid_t dxp
                 hid_t *oid_list = va_arg (arguments, hid_t *);
                 ssize_t *ret = va_arg (arguments, ssize_t *);
 
-                if((ret_value = H5VL_file_get(file, vol_plugin, get_type, dxpl_id, H5_EVENT_QUEUE_NULL, types, max_objs, 
+                if((ret_value = H5VL_file_get(file, vol_plugin, get_type, dxpl_id, H5_EVENT_STACK_NULL, types, max_objs, 
                                               oid_list, ret)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to get file information")
                 break;
@@ -1389,7 +1389,7 @@ H5VLfile_get(void *file, H5VL_t *vol_plugin, H5VL_file_get_t get_type, hid_t dxp
             {
                 unsigned *ret = va_arg (arguments, unsigned *);
 
-                if((ret_value = H5VL_file_get(file, vol_plugin, get_type, dxpl_id, H5_EVENT_QUEUE_NULL, ret)) < 0)
+                if((ret_value = H5VL_file_get(file, vol_plugin, get_type, dxpl_id, H5_EVENT_STACK_NULL, ret)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to get file information")
                 break;
             }
@@ -1401,7 +1401,7 @@ H5VLfile_get(void *file, H5VL_t *vol_plugin, H5VL_file_get_t get_type, hid_t dxp
                 char      *name = va_arg (arguments, char *);
                 ssize_t   *ret  = va_arg (arguments, ssize_t *);
 
-                if((ret_value = H5VL_file_get(file, vol_plugin, get_type, dxpl_id, H5_EVENT_QUEUE_NULL, type, size, 
+                if((ret_value = H5VL_file_get(file, vol_plugin, get_type, dxpl_id, H5_EVENT_STACK_NULL, type, size, 
                                               name, ret)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to get file information")
                 break;
@@ -1412,7 +1412,7 @@ H5VLfile_get(void *file, H5VL_t *vol_plugin, H5VL_file_get_t get_type, hid_t dxp
                 H5I_type_t type = va_arg (arguments, H5I_type_t);
                 void      **ret = va_arg (arguments, void **);
 
-                if((ret_value = H5VL_file_get(file, vol_plugin, get_type, dxpl_id, H5_EVENT_QUEUE_NULL, type, ret)) < 0)
+                if((ret_value = H5VL_file_get(file, vol_plugin, get_type, dxpl_id, H5_EVENT_STACK_NULL, type, ret)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to get file information")
                 break;
             }
@@ -1457,7 +1457,7 @@ H5VLfile_misc(void *file, H5VL_t *vol_plugin, H5VL_file_misc_t misc_type, hid_t
                 H5F_t      *child      = va_arg (arguments, H5F_t *);
                 hid_t       plist_id   = va_arg (arguments, hid_t);
 
-                if((ret_value = H5VL_file_misc(file, vol_plugin, misc_type, dxpl_id, H5_EVENT_QUEUE_NULL, 
+                if((ret_value = H5VL_file_misc(file, vol_plugin, misc_type, dxpl_id, H5_EVENT_STACK_NULL, 
                                                type, name, child, plist_id)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to operate on the file")
 
@@ -1469,7 +1469,7 @@ H5VLfile_misc(void *file, H5VL_t *vol_plugin, H5VL_file_misc_t misc_type, hid_t
                 H5I_type_t  type       = va_arg (arguments, H5I_type_t);
                 const char *name       = va_arg (arguments, const char *);
 
-                if((ret_value = H5VL_file_misc(file, vol_plugin, misc_type, dxpl_id, H5_EVENT_QUEUE_NULL, type, name)) < 0)
+                if((ret_value = H5VL_file_misc(file, vol_plugin, misc_type, dxpl_id, H5_EVENT_STACK_NULL, type, name)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to operate on the file")
                 break;
             }
@@ -1480,7 +1480,7 @@ H5VLfile_misc(void *file, H5VL_t *vol_plugin, H5VL_file_misc_t misc_type, hid_t
                 const char *name    = va_arg (arguments, const char *);
                 htri_t     *ret     = va_arg (arguments, htri_t *);
 
-                if((ret_value = H5VL_file_misc(file, vol_plugin, misc_type, dxpl_id, H5_EVENT_QUEUE_NULL, fapl_id, name, ret)) < 0)
+                if((ret_value = H5VL_file_misc(file, vol_plugin, misc_type, dxpl_id, H5_EVENT_STACK_NULL, fapl_id, name, ret)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to operate on the file")
                 break;
             }
@@ -1522,7 +1522,7 @@ H5VLfile_optional(void *file, H5VL_t *vol_plugin, H5VL_file_optional_t optional_
             {
                 hsize_t    *ret = va_arg (arguments, hsize_t *);
 
-                if((ret_value = H5VL_file_optional(file, vol_plugin, optional_type, dxpl_id, H5_EVENT_QUEUE_NULL, ret)) < 0)
+                if((ret_value = H5VL_file_optional(file, vol_plugin, optional_type, dxpl_id, H5_EVENT_STACK_NULL, ret)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to operate on the file")
                 break;
             }
@@ -1533,7 +1533,7 @@ H5VLfile_optional(void *file, H5VL_t *vol_plugin, H5VL_file_optional_t optional_
                 ssize_t    *ret       = va_arg (arguments, ssize_t *);
                 size_t      buf_len   = va_arg (arguments, size_t );
 
-                if((ret_value = H5VL_file_optional(file, vol_plugin, optional_type, dxpl_id, H5_EVENT_QUEUE_NULL, 
+                if((ret_value = H5VL_file_optional(file, vol_plugin, optional_type, dxpl_id, H5_EVENT_STACK_NULL, 
                                                    buf_ptr, ret, buf_len)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to operate on the file")
                 break;
@@ -1543,7 +1543,7 @@ H5VLfile_optional(void *file, H5VL_t *vol_plugin, H5VL_file_optional_t optional_
             {
                 hssize_t    *ret = va_arg (arguments, hssize_t *);
 
-                if((ret_value = H5VL_file_optional(file, vol_plugin, optional_type, dxpl_id, H5_EVENT_QUEUE_NULL, ret)) < 0)
+                if((ret_value = H5VL_file_optional(file, vol_plugin, optional_type, dxpl_id, H5_EVENT_STACK_NULL, ret)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to operate on the file")
                 break;
             }
@@ -1554,7 +1554,7 @@ H5VLfile_optional(void *file, H5VL_t *vol_plugin, H5VL_file_optional_t optional_
                 H5F_mem_t       type       = va_arg (arguments, H5F_mem_t);
                 size_t          nsects     = va_arg (arguments, size_t);
 
-                if((ret_value = H5VL_file_optional(file, vol_plugin, optional_type, dxpl_id, H5_EVENT_QUEUE_NULL,
+                if((ret_value = H5VL_file_optional(file, vol_plugin, optional_type, dxpl_id, H5_EVENT_STACK_NULL,
                                                    sect_info, ret, type, nsects)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to operate on the file")
                 break;
@@ -1565,7 +1565,7 @@ H5VLfile_optional(void *file, H5VL_t *vol_plugin, H5VL_file_optional_t optional_
                 H5I_type_t  type   = va_arg (arguments, H5I_type_t);
                 H5F_info2_t *finfo = va_arg (arguments, H5F_info2_t *);
 
-                if((ret_value = H5VL_file_optional(file, vol_plugin, optional_type, dxpl_id, H5_EVENT_QUEUE_NULL, type, finfo)) < 0)
+                if((ret_value = H5VL_file_optional(file, vol_plugin, optional_type, dxpl_id, H5_EVENT_STACK_NULL, type, finfo)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to operate on the file")
                 break;
             }
@@ -1574,7 +1574,7 @@ H5VLfile_optional(void *file, H5VL_t *vol_plugin, H5VL_file_optional_t optional_
             {
                 H5AC_cache_config_t *config_ptr = va_arg (arguments, H5AC_cache_config_t *);
 
-                if((ret_value = H5VL_file_optional(file, vol_plugin, optional_type, dxpl_id, H5_EVENT_QUEUE_NULL, config_ptr)) < 0)
+                if((ret_value = H5VL_file_optional(file, vol_plugin, optional_type, dxpl_id, H5_EVENT_STACK_NULL, config_ptr)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to operate on the file")
                 break;
             }
@@ -1583,7 +1583,7 @@ H5VLfile_optional(void *file, H5VL_t *vol_plugin, H5VL_file_optional_t optional_
             {
                 double *hit_rate_ptr = va_arg (arguments, double *);
 
-                if((ret_value = H5VL_file_optional(file, vol_plugin, optional_type, dxpl_id, H5_EVENT_QUEUE_NULL, hit_rate_ptr)) < 0)
+                if((ret_value = H5VL_file_optional(file, vol_plugin, optional_type, dxpl_id, H5_EVENT_STACK_NULL, hit_rate_ptr)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to operate on the file")
                 break;
             }
@@ -1595,7 +1595,7 @@ H5VLfile_optional(void *file, H5VL_t *vol_plugin, H5VL_file_optional_t optional_
                 size_t *cur_size_ptr        = va_arg (arguments, size_t *); 
                 int    *cur_num_entries_ptr = va_arg (arguments, int *); 
 
-                if((ret_value = H5VL_file_optional(file, vol_plugin, optional_type, dxpl_id, H5_EVENT_QUEUE_NULL, max_size_ptr, 
+                if((ret_value = H5VL_file_optional(file, vol_plugin, optional_type, dxpl_id, H5_EVENT_STACK_NULL, max_size_ptr, 
                                                    min_clean_size_ptr, cur_size_ptr, cur_num_entries_ptr)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to operate on the file")
                 break;
@@ -1606,14 +1606,14 @@ H5VLfile_optional(void *file, H5VL_t *vol_plugin, H5VL_file_optional_t optional_
                 void **file_handle = va_arg (arguments, void **);
                 hid_t  fapl        = va_arg (arguments, hid_t);
 
-                if((ret_value = H5VL_file_optional(file, vol_plugin, optional_type, dxpl_id, H5_EVENT_QUEUE_NULL, file_handle, fapl)) < 0)
+                if((ret_value = H5VL_file_optional(file, vol_plugin, optional_type, dxpl_id, H5_EVENT_STACK_NULL, file_handle, fapl)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to operate on the file")
                 break;
             }
         /* H5Fclear_elink_file_cache */
         case H5VL_FILE_CLEAR_ELINK_CACHE:
             {
-                if((ret_value = H5VL_file_optional(file, vol_plugin, optional_type, dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+                if((ret_value = H5VL_file_optional(file, vol_plugin, optional_type, dxpl_id, H5_EVENT_STACK_NULL)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to operate on the file")
                 break;
             }
@@ -1622,14 +1622,14 @@ H5VLfile_optional(void *file, H5VL_t *vol_plugin, H5VL_file_optional_t optional_
             {
                 void   **ret = va_arg (arguments, void **);
 
-                if((ret_value = H5VL_file_optional(file, vol_plugin, optional_type, dxpl_id, H5_EVENT_QUEUE_NULL, ret)) < 0)
+                if((ret_value = H5VL_file_optional(file, vol_plugin, optional_type, dxpl_id, H5_EVENT_STACK_NULL, ret)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to operate on the file")
                 break;
             }
         /* H5Freset_mdc_hit_rate_stats */
         case H5VL_FILE_RESET_MDC_HIT_RATE:
             {
-                if((ret_value = H5VL_file_optional(file, vol_plugin, optional_type, dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+                if((ret_value = H5VL_file_optional(file, vol_plugin, optional_type, dxpl_id, H5_EVENT_STACK_NULL)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to operate on the file")
                 break;
             }
@@ -1637,7 +1637,7 @@ H5VLfile_optional(void *file, H5VL_t *vol_plugin, H5VL_file_optional_t optional_
             {
                 H5AC_cache_config_t *config_ptr = va_arg (arguments, H5AC_cache_config_t *);
 
-                if((ret_value = H5VL_file_optional(file, vol_plugin, optional_type, dxpl_id, H5_EVENT_QUEUE_NULL, config_ptr)) < 0)
+                if((ret_value = H5VL_file_optional(file, vol_plugin, optional_type, dxpl_id, H5_EVENT_STACK_NULL, config_ptr)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to operate on the file")
                 break;
             }
@@ -1673,7 +1673,7 @@ H5VLfile_close(void *file, H5VL_t *vol_plugin, hid_t dxpl_id, void UNUSED **req)
 
     if(NULL == file || NULL == vol_plugin || NULL == vol_plugin->cls)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid object/VOL class pointer")
-    if((ret_value = H5VL_file_close(file, vol_plugin, dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+    if((ret_value = H5VL_file_close(file, vol_plugin, dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_VOL, H5E_CANTRELEASE, FAIL, "unable to close file")
 
 done:
@@ -1706,7 +1706,7 @@ H5VLgroup_create(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, co
     if (NULL == obj || NULL == vol_plugin || NULL == vol_plugin->cls)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, NULL, "invalid object/VOL class pointer")
     if(NULL == (ret_value = H5VL_group_create(obj, loc_params, vol_plugin, name, 
-                                              gcpl_id, gapl_id, dxpl_id, H5_EVENT_QUEUE_NULL)))
+                                              gcpl_id, gapl_id, dxpl_id, H5_EVENT_STACK_NULL)))
 	HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, NULL, "unable to create group")
 
 done:
@@ -1739,7 +1739,7 @@ H5VLgroup_open(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, cons
     if (NULL == obj || NULL == vol_plugin || NULL == vol_plugin->cls)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, NULL, "invalid object/VOL class pointer")
     if(NULL == (ret_value = H5VL_group_open(obj, loc_params, vol_plugin, name, 
-                                              gapl_id, dxpl_id, H5_EVENT_QUEUE_NULL)))
+                                              gapl_id, dxpl_id, H5_EVENT_STACK_NULL)))
 	HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, NULL, "unable to open group")
 
 done:
@@ -1777,7 +1777,7 @@ H5VLgroup_get(void *obj, H5VL_t *vol_plugin, H5VL_group_get_t get_type, hid_t dx
             {
                 hid_t *new_gcpl_id = va_arg (arguments, hid_t *);
 
-                if((ret_value = H5VL_group_get(obj, vol_plugin, get_type, dxpl_id, H5_EVENT_QUEUE_NULL, new_gcpl_id)) < 0)
+                if((ret_value = H5VL_group_get(obj, vol_plugin, get_type, dxpl_id, H5_EVENT_STACK_NULL, new_gcpl_id)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to get group information")
                 break;
             }
@@ -1787,7 +1787,7 @@ H5VLgroup_get(void *obj, H5VL_t *vol_plugin, H5VL_group_get_t get_type, hid_t dx
                 H5VL_loc_params_t loc_params = va_arg (arguments, H5VL_loc_params_t);
                 H5G_info_t  *grp_info = va_arg (arguments, H5G_info_t *);
 
-                if((ret_value = H5VL_group_get(obj, vol_plugin, get_type, dxpl_id, H5_EVENT_QUEUE_NULL, loc_params, grp_info)) < 0)
+                if((ret_value = H5VL_group_get(obj, vol_plugin, get_type, dxpl_id, H5_EVENT_STACK_NULL, loc_params, grp_info)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to get group information")
                 break;
             }
@@ -1823,7 +1823,7 @@ H5VLgroup_close(void *grp, H5VL_t *vol_plugin, hid_t dxpl_id, void UNUSED **req)
 
     if(NULL == grp || NULL == vol_plugin || NULL == vol_plugin->cls)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid object/VOL class pointer")
-    if((ret_value = H5VL_group_close(grp, vol_plugin, dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+    if((ret_value = H5VL_group_close(grp, vol_plugin, dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_VOL, H5E_CANTRELEASE, FAIL, "unable to close group")
 
 done:
@@ -1853,7 +1853,7 @@ H5VLlink_create(H5VL_link_create_type_t create_type, void *obj, H5VL_loc_params_
 
     if(NULL == obj || NULL == vol_plugin || NULL == vol_plugin->cls)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid object/VOL class pointer")
-    if((ret_value = H5VL_link_create(create_type, obj, loc_params, vol_plugin, lcpl_id, lapl_id, dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+    if((ret_value = H5VL_link_create(create_type, obj, loc_params, vol_plugin, lcpl_id, lapl_id, dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to create link")
 
 done:
@@ -1884,7 +1884,7 @@ H5_DLL herr_t H5VLlink_move(void *src_obj, H5VL_loc_params_t loc_params1, void *
     if(NULL == src_obj || NULL == dst_obj || NULL == vol_plugin || NULL == vol_plugin->cls)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid object/VOL class pointer")
     if((ret_value = H5VL_link_move(src_obj, loc_params1, dst_obj, loc_params2, vol_plugin, 
-                                   copy_flag, lcpl_id, lapl_id, dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+                                   copy_flag, lcpl_id, lapl_id, dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to move object")
 
 done:
@@ -1916,7 +1916,7 @@ herr_t H5VLlink_iterate(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plu
     if(NULL == obj || NULL == vol_plugin || NULL == vol_plugin->cls)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid object/VOL class pointer")
     if((ret_value = H5VL_link_iterate(obj, loc_params, vol_plugin, recursive, idx_type, order, idx,
-                                      op, op_data, dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+                                      op, op_data, dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "Link iteration failed")
 
 done:
@@ -1955,7 +1955,7 @@ H5VLlink_get(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, H5VL_l
             {
                 htri_t     *ret    = va_arg (arguments, htri_t *);
 
-                if((ret_value = H5VL_link_get(obj, loc_params, vol_plugin, get_type, dxpl_id, H5_EVENT_QUEUE_NULL, ret)) < 0)
+                if((ret_value = H5VL_link_get(obj, loc_params, vol_plugin, get_type, dxpl_id, H5_EVENT_STACK_NULL, ret)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to get link information")
                 break;
             }
@@ -1964,7 +1964,7 @@ H5VLlink_get(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, H5VL_l
             {
                 H5L_info_t *linfo  = va_arg (arguments, H5L_info_t *);
 
-                if((ret_value = H5VL_link_get(obj, loc_params, vol_plugin, get_type, dxpl_id, H5_EVENT_QUEUE_NULL, linfo)) < 0)
+                if((ret_value = H5VL_link_get(obj, loc_params, vol_plugin, get_type, dxpl_id, H5_EVENT_STACK_NULL, linfo)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to get link information")
                 break;
             }
@@ -1975,7 +1975,7 @@ H5VLlink_get(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, H5VL_l
                 size_t      size   = va_arg (arguments, size_t);
                 ssize_t    *ret    = va_arg (arguments, ssize_t *);
 
-                if((ret_value = H5VL_link_get(obj, loc_params, vol_plugin, get_type, dxpl_id, H5_EVENT_QUEUE_NULL, 
+                if((ret_value = H5VL_link_get(obj, loc_params, vol_plugin, get_type, dxpl_id, H5_EVENT_STACK_NULL, 
                                               name, size, ret)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to get link information")
                 break;
@@ -1986,7 +1986,7 @@ H5VLlink_get(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, H5VL_l
                 void       *buf    = va_arg (arguments, void *);
                 size_t     size    = va_arg (arguments, size_t);
 
-                if((ret_value = H5VL_link_get(obj, loc_params, vol_plugin, get_type, dxpl_id, H5_EVENT_QUEUE_NULL, buf, size)) < 0)
+                if((ret_value = H5VL_link_get(obj, loc_params, vol_plugin, get_type, dxpl_id, H5_EVENT_STACK_NULL, buf, size)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to get link information")
                 break;
             }
@@ -2019,7 +2019,7 @@ H5_DLL herr_t H5VLlink_remove(void *obj, H5VL_loc_params_t loc_params, H5VL_t *v
 
     if(NULL == obj || NULL == vol_plugin || NULL == vol_plugin->cls)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid object/VOL class pointer")
-    if((ret_value = H5VL_link_remove(obj, loc_params, vol_plugin, dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+    if((ret_value = H5VL_link_remove(obj, loc_params, vol_plugin, dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to remove link")
 
 done:
@@ -2051,7 +2051,7 @@ H5VLobject_open(void *obj, H5VL_loc_params_t params, H5VL_t *vol_plugin, H5I_typ
 
     if (NULL == obj || NULL == vol_plugin || NULL == vol_plugin->cls)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, NULL, "invalid object/VOL class pointer")
-    if(NULL == (ret_value = H5VL_object_open(obj, params, vol_plugin, opened_type, dxpl_id, H5_EVENT_QUEUE_NULL)))
+    if(NULL == (ret_value = H5VL_object_open(obj, params, vol_plugin, opened_type, dxpl_id, H5_EVENT_STACK_NULL)))
 	HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, NULL, "unable to create group")
 
 done:
@@ -2086,7 +2086,7 @@ H5VLobject_copy(void *src_obj, H5VL_loc_params_t loc_params1, H5VL_t *vol_plugin
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid object/VOL class pointer")
     if((ret_value = H5VL_object_copy(src_obj, loc_params1, vol_plugin1, src_name, 
                                      dst_obj, loc_params2, vol_plugin2, dst_name,
-                                     ocpypl_id, lcpl_id, dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+                                     ocpypl_id, lcpl_id, dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "unable to move object")
 
 done:
@@ -2117,7 +2117,7 @@ herr_t H5VLobject_visit(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plu
     if(NULL == obj || NULL == vol_plugin || NULL == vol_plugin->cls)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid object/VOL class pointer")
     if((ret_value = H5VL_object_visit(obj, loc_params, vol_plugin, idx_type, order, 
-                                      op, op_data, dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+                                      op, op_data, dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "Object Visit Failed")
 
 done:
@@ -2156,7 +2156,7 @@ H5VLobject_get(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, H5VL
             {
                 htri_t	  *ret      = va_arg (arguments, htri_t *);
 
-                if((ret_value = H5VL_object_get(obj, loc_params, vol_plugin, get_type, dxpl_id, H5_EVENT_QUEUE_NULL, ret)) < 0)
+                if((ret_value = H5VL_object_get(obj, loc_params, vol_plugin, get_type, dxpl_id, H5_EVENT_STACK_NULL, ret)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "Object Visit Failed")
                 break;
             }
@@ -2165,7 +2165,7 @@ H5VLobject_get(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, H5VL
             {
                 H5O_info_t  *obj_info = va_arg (arguments, H5O_info_t *);
 
-                if((ret_value = H5VL_object_get(obj, loc_params, vol_plugin, get_type, dxpl_id, H5_EVENT_QUEUE_NULL, obj_info)) < 0)
+                if((ret_value = H5VL_object_get(obj, loc_params, vol_plugin, get_type, dxpl_id, H5_EVENT_STACK_NULL, obj_info)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "Object Visit Failed")
                 break;
             }
@@ -2176,7 +2176,7 @@ H5VLobject_get(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, H5VL
                 size_t   bufsize  =  va_arg (arguments, size_t);
                 ssize_t  *ret     =  va_arg (arguments, ssize_t *);
 
-                if((ret_value = H5VL_object_get(obj, loc_params, vol_plugin, get_type, dxpl_id, H5_EVENT_QUEUE_NULL,
+                if((ret_value = H5VL_object_get(obj, loc_params, vol_plugin, get_type, dxpl_id, H5_EVENT_STACK_NULL,
                                                 comment, bufsize, ret)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "Object Visit Failed")
                 break;
@@ -2188,7 +2188,7 @@ H5VLobject_get(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, H5VL
                 H5R_type_t  ref_type =  va_arg (arguments, H5R_type_t);
                 void        *ref     =  va_arg (arguments, void *);
 
-                if((ret_value = H5VL_object_get(obj, loc_params, vol_plugin, get_type, dxpl_id, H5_EVENT_QUEUE_NULL,
+                if((ret_value = H5VL_object_get(obj, loc_params, vol_plugin, get_type, dxpl_id, H5_EVENT_STACK_NULL,
                                                 ret, ref_type, ref)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "Object Visit Failed")
                 break;
@@ -2200,7 +2200,7 @@ H5VLobject_get(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, H5VL
                 H5R_type_t  ref_type   =  va_arg (arguments, H5R_type_t);
                 void        *ref       =  va_arg (arguments, void *);
 
-                if((ret_value = H5VL_object_get(obj, loc_params, vol_plugin, get_type, dxpl_id, H5_EVENT_QUEUE_NULL,
+                if((ret_value = H5VL_object_get(obj, loc_params, vol_plugin, get_type, dxpl_id, H5_EVENT_STACK_NULL,
                                                 obj_type, ref_type, ref)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "Object Visit Failed")
                 break;
@@ -2214,7 +2214,7 @@ H5VLobject_get(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, H5VL
                 H5R_type_t  ref_type   = va_arg (arguments, H5R_type_t);
                 void        *ref       = va_arg (arguments, void *);
 
-                if((ret_value = H5VL_object_get(obj, loc_params, vol_plugin, get_type, dxpl_id, H5_EVENT_QUEUE_NULL,
+                if((ret_value = H5VL_object_get(obj, loc_params, vol_plugin, get_type, dxpl_id, H5_EVENT_STACK_NULL,
                                                 ret, name, size, ref_type, ref)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "Object Visit Failed")
                 break;
@@ -2259,7 +2259,7 @@ H5VLobject_misc(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, H5V
                 const char    *old_name  = va_arg (arguments, const char *);
                 const char    *new_name  = va_arg (arguments, const char *);
 
-                if((ret_value = H5VL_object_misc(obj, loc_params, vol_plugin, misc_type, dxpl_id, H5_EVENT_QUEUE_NULL,
+                if((ret_value = H5VL_object_misc(obj, loc_params, vol_plugin, misc_type, dxpl_id, H5_EVENT_STACK_NULL,
                                                  old_name, new_name)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "Object Visit Failed")
                 break;
@@ -2269,7 +2269,7 @@ H5VLobject_misc(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, H5V
             {
                 int update_ref  = va_arg (arguments, int);
 
-                if((ret_value = H5VL_object_misc(obj, loc_params, vol_plugin, misc_type, dxpl_id, H5_EVENT_QUEUE_NULL, update_ref)) < 0)
+                if((ret_value = H5VL_object_misc(obj, loc_params, vol_plugin, misc_type, dxpl_id, H5_EVENT_STACK_NULL, update_ref)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "Object Visit Failed")
                 break;
             }
@@ -2278,7 +2278,7 @@ H5VLobject_misc(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, H5V
             {
                 const char    *comment  = va_arg (arguments, char *);
 
-                if((ret_value = H5VL_object_misc(obj, loc_params, vol_plugin, misc_type, dxpl_id, H5_EVENT_QUEUE_NULL, comment)) < 0)
+                if((ret_value = H5VL_object_misc(obj, loc_params, vol_plugin, misc_type, dxpl_id, H5_EVENT_STACK_NULL, comment)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "Object Visit Failed")
                 break;
             }
@@ -2289,7 +2289,7 @@ H5VLobject_misc(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, H5V
                 H5R_type_t  ref_type  = va_arg (arguments, H5R_type_t);
                 hid_t       space_id  = va_arg (arguments, hid_t);
 
-                if((ret_value = H5VL_object_misc(obj, loc_params, vol_plugin, misc_type, dxpl_id, H5_EVENT_QUEUE_NULL,
+                if((ret_value = H5VL_object_misc(obj, loc_params, vol_plugin, misc_type, dxpl_id, H5_EVENT_STACK_NULL,
                                                  ref, name, ref_type, space_id)) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "Object Visit Failed")
                 break;
@@ -2326,7 +2326,7 @@ H5VLobject_close(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, hi
 
     if(NULL == obj || NULL == vol_plugin || NULL == vol_plugin->cls)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid object/VOL class pointer")
-    if((ret_value = H5VL_object_close(obj, loc_params, vol_plugin, dxpl_id, H5_EVENT_QUEUE_NULL)) < 0)
+    if((ret_value = H5VL_object_close(obj, loc_params, vol_plugin, dxpl_id, H5_EVENT_STACK_NULL)) < 0)
 	HGOTO_ERROR(H5E_VOL, H5E_CANTRELEASE, FAIL, "unable to close object")
 
 done:
@@ -2348,7 +2348,7 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5VLrequest_cancel(void **req, H5VL_t *vol_plugin, H5_status_t *status)
+H5VLrequest_cancel(void **req, H5VL_t *vol_plugin, H5ES_status_t *status)
 {
     herr_t ret_value = SUCCEED;
 
@@ -2378,7 +2378,7 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5VLrequest_test(void **req, H5VL_t *vol_plugin, H5_status_t *status)
+H5VLrequest_test(void **req, H5VL_t *vol_plugin, H5ES_status_t *status)
 {
     herr_t ret_value = SUCCEED;
 
@@ -2408,7 +2408,7 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5VLrequest_wait(void **req, H5VL_t *vol_plugin, H5_status_t *status)
+H5VLrequest_wait(void **req, H5VL_t *vol_plugin, H5ES_status_t *status)
 {
     herr_t ret_value = SUCCEED;
 
diff --git a/src/H5VLint.c b/src/H5VLint.c
index f5d7e24..65250a1 100644
--- a/src/H5VLint.c
+++ b/src/H5VLint.c
@@ -475,7 +475,7 @@ done:
  */
 void *
 H5VL_attr_create(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, const char *name, 
-                 hid_t acpl_id, hid_t aapl_id, hid_t dxpl_id, hid_t UNUSED event_q)
+                 hid_t acpl_id, hid_t aapl_id, hid_t dxpl_id, hid_t UNUSED estack_id)
 {
     void *ret_value;  /* Return value */
 
@@ -512,7 +512,7 @@ done:
  */
 void *
 H5VL_attr_open(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, const char *name, 
-               hid_t aapl_id, hid_t dxpl_id, hid_t UNUSED event_q)
+               hid_t aapl_id, hid_t dxpl_id, hid_t UNUSED estack_id)
 {
     void *ret_value;  /* Return value */
 
@@ -546,7 +546,7 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t H5VL_attr_read(void *attr, H5VL_t *vol_plugin, hid_t mem_type_id, void *buf, 
-                      hid_t dxpl_id, hid_t UNUSED event_q)
+                      hid_t dxpl_id, hid_t UNUSED estack_id)
 {
     herr_t              ret_value = SUCCEED;
 
@@ -577,7 +577,7 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t H5VL_attr_write(void *attr, H5VL_t *vol_plugin, hid_t mem_type_id, const void *buf, 
-                       hid_t dxpl_id, hid_t UNUSED event_q)
+                       hid_t dxpl_id, hid_t UNUSED estack_id)
 {
     herr_t              ret_value = SUCCEED;
 
@@ -609,7 +609,7 @@ done:
 herr_t 
 H5VL_attr_iterate(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, 
                   H5_index_t idx_type, H5_iter_order_t order, hsize_t *n, 
-                  H5A_operator2_t op, void *op_data, hid_t dxpl_id, hid_t UNUSED event_q)
+                  H5A_operator2_t op, void *op_data, hid_t dxpl_id, hid_t UNUSED estack_id)
 {
     herr_t            ret_value = SUCCEED;
 
@@ -642,7 +642,7 @@ done:
  */
 herr_t
 H5VL_attr_get(void *obj, H5VL_t *vol_plugin, H5VL_attr_get_t get_type, 
-              hid_t dxpl_id, hid_t event_q, ...)
+              hid_t dxpl_id, hid_t estack_id, ...)
 {
     va_list           arguments;             /* argument list passed from the API call */
     herr_t            ret_value = SUCCEED;
@@ -651,7 +651,7 @@ H5VL_attr_get(void *obj, H5VL_t *vol_plugin, H5VL_attr_get_t get_type,
 
     if(NULL == vol_plugin->cls->attr_cls.get)
 	HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "vol plugin has no `attr get' method")
-    va_start (arguments, event_q);
+    va_start (arguments, estack_id);
     if((ret_value = (vol_plugin->cls->attr_cls.get)(obj, get_type, dxpl_id, H5_REQUEST_NULL, arguments)) < 0)
         HGOTO_ERROR(H5E_VOL, H5E_CANTGET, FAIL, "get failed")
     va_end (arguments);
@@ -660,7 +660,7 @@ H5VL_attr_get(void *obj, H5VL_t *vol_plugin, H5VL_attr_get_t get_type,
     if(H5VL_ATTR_GET_TYPE == get_type) {
         hid_t           *ret_id;
 
-        va_start (arguments, event_q);
+        va_start (arguments, estack_id);
         ret_id = va_arg (arguments, hid_t *);
 
         if(H5Tcommitted(*ret_id)) {
@@ -692,7 +692,7 @@ done:
  */
 herr_t 
 H5VL_attr_remove(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, 
-                 const char *attr_name, hid_t dxpl_id, hid_t UNUSED event_q)
+                 const char *attr_name, hid_t dxpl_id, hid_t UNUSED estack_id)
 {
     herr_t              ret_value = SUCCEED;
 
@@ -723,7 +723,7 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5VL_attr_close(void *attr, H5VL_t *vol_plugin, hid_t dxpl_id, hid_t UNUSED event_q)
+H5VL_attr_close(void *attr, H5VL_t *vol_plugin, hid_t dxpl_id, hid_t UNUSED estack_id)
 {
     herr_t              ret_value = SUCCEED;
 
@@ -734,7 +734,7 @@ H5VL_attr_close(void *attr, H5VL_t *vol_plugin, hid_t dxpl_id, hid_t UNUSED even
     if(NULL == vol_plugin->cls->attr_cls.close){
         HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "vol plugin has no `attr close' method")
         /*
-        if(H5VL_object_close(id, dxpl_id, event_q) < 0)
+        if(H5VL_object_close(id, dxpl_id, estack_id) < 0)
             HGOTO_ERROR(H5E_SYM, H5E_CANTRELEASE, FAIL, "unable to close object")
         */
     }
@@ -770,7 +770,7 @@ done:
 void *
 H5VL_datatype_commit(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, const char *name, 
                      hid_t type_id, hid_t lcpl_id, hid_t tcpl_id, hid_t tapl_id, 
-                     hid_t dxpl_id, hid_t UNUSED event_q)
+                     hid_t dxpl_id, hid_t UNUSED estack_id)
 {
     void *ret_value = NULL;              /* Return value */
 
@@ -807,7 +807,7 @@ done:
  */
 void *
 H5VL_datatype_open(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, const char *name, 
-                   hid_t tapl_id, hid_t dxpl_id, hid_t UNUSED event_q)
+                   hid_t tapl_id, hid_t dxpl_id, hid_t UNUSED estack_id)
 {
     void *ret_value = NULL;              /* Return value */
 
@@ -824,7 +824,7 @@ H5VL_datatype_open(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin,
         loc_params.loc_data.loc_by_name.plist_id = tapl_id;
 
         /* Open the object class */
-        if((ret_value = H5VL_object_open(id, loc_params, dxpl_id, event_q)) < 0)
+        if((ret_value = H5VL_object_open(id, loc_params, dxpl_id, estack_id)) < 0)
             HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, NULL, "unable to open object")
 #endif
     /* call the corresponding VOL open callback */
@@ -853,7 +853,7 @@ done:
  */
 ssize_t 
 H5VL_datatype_get_binary(void *obj, H5VL_t *vol_plugin, unsigned char *buf, size_t size, 
-                         hid_t dxpl_id, hid_t UNUSED event_q)
+                         hid_t dxpl_id, hid_t UNUSED estack_id)
 {
     ssize_t ret_value = FAIL;
 
@@ -887,7 +887,7 @@ done:
  */
 herr_t
 H5VL_datatype_get(void *obj, H5VL_t *vol_plugin, H5VL_datatype_get_t get_type, 
-                  hid_t dxpl_id, hid_t event_q, ...)
+                  hid_t dxpl_id, hid_t estack_id, ...)
 {
     va_list           arguments;             /* argument list passed from the API call */
     herr_t            ret_value = SUCCEED;
@@ -896,7 +896,7 @@ H5VL_datatype_get(void *obj, H5VL_t *vol_plugin, H5VL_datatype_get_t get_type,
 
     if(NULL == vol_plugin->cls->datatype_cls.get)
 	HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "vol plugin has no `datatype get' method")
-    va_start (arguments, event_q);
+    va_start (arguments, estack_id);
     if((ret_value = (vol_plugin->cls->datatype_cls.get)(obj, get_type, dxpl_id, 
                                                         H5_REQUEST_NULL, arguments)) < 0)
         HGOTO_ERROR(H5E_VOL, H5E_CANTGET, FAIL, "get failed")
@@ -921,7 +921,7 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5VL_datatype_close(void *dt, H5VL_t *vol_plugin, hid_t dxpl_id, hid_t UNUSED event_q)
+H5VL_datatype_close(void *dt, H5VL_t *vol_plugin, hid_t dxpl_id, hid_t UNUSED estack_id)
 {
     herr_t		ret_value = SUCCEED;    /* Return value */
 
@@ -962,7 +962,7 @@ done:
  */
 void *
 H5VL_dataset_create(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, const char *name, 
-                    hid_t dcpl_id, hid_t dapl_id, hid_t dxpl_id, hid_t UNUSED event_q)
+                    hid_t dcpl_id, hid_t dapl_id, hid_t dxpl_id, hid_t UNUSED estack_id)
 {
     void *ret_value; /* Return value */
 
@@ -997,7 +997,7 @@ done:
  */
 void *
 H5VL_dataset_open(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, const char *name, 
-                  hid_t dapl_id, hid_t dxpl_id, hid_t UNUSED event_q)
+                  hid_t dapl_id, hid_t dxpl_id, hid_t UNUSED estack_id)
 {
     void *ret_value; /* Return value */
 
@@ -1008,7 +1008,7 @@ H5VL_dataset_open(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, c
         ;
 #if 0
         /* Open the object class */
-        if((ret_value = H5VL_object_open(id, loc_params, dxpl_id, event_q)) < 0)
+        if((ret_value = H5VL_object_open(id, loc_params, dxpl_id, estack_id)) < 0)
             HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, NULL, "unable to open object")
 #endif
     }
@@ -1040,7 +1040,7 @@ done:
  */
 herr_t 
 H5VL_dataset_read(void *dset, H5VL_t *vol_plugin, hid_t mem_type_id, hid_t mem_space_id, 
-                  hid_t file_space_id, hid_t plist_id, void *buf, hid_t UNUSED event_q)
+                  hid_t file_space_id, hid_t plist_id, void *buf, hid_t UNUSED estack_id)
 {
     herr_t              ret_value = SUCCEED;
 
@@ -1073,7 +1073,7 @@ done:
  */
 herr_t 
 H5VL_dataset_write(void *dset, H5VL_t *vol_plugin, hid_t mem_type_id, hid_t mem_space_id, 
-                   hid_t file_space_id, hid_t plist_id, const void *buf, hid_t UNUSED event_q)
+                   hid_t file_space_id, hid_t plist_id, const void *buf, hid_t UNUSED estack_id)
 {
     herr_t              ret_value = SUCCEED;
 
@@ -1106,7 +1106,7 @@ done:
  */
 herr_t 
 H5VL_dataset_set_extent(void *dset, H5VL_t *vol_plugin, const hsize_t size[], 
-                        hid_t dxpl_id, hid_t UNUSED event_q)
+                        hid_t dxpl_id, hid_t UNUSED estack_id)
 {
     herr_t              ret_value = SUCCEED;
 
@@ -1138,7 +1138,7 @@ done:
  */
 herr_t
 H5VL_dataset_get(void *dset, H5VL_t *vol_plugin, H5VL_dataset_get_t get_type, 
-                 hid_t dxpl_id, hid_t event_q, ...)
+                 hid_t dxpl_id, hid_t estack_id, ...)
 {
     va_list           arguments;             /* argument list passed from the API call */
     herr_t            ret_value = SUCCEED;
@@ -1148,7 +1148,7 @@ H5VL_dataset_get(void *dset, H5VL_t *vol_plugin, H5VL_dataset_get_t get_type,
     if(NULL == vol_plugin->cls->dataset_cls.get)
 	HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "vol plugin has no `dataset get' method")
 
-    va_start (arguments, event_q);
+    va_start (arguments, estack_id);
     if((ret_value = (vol_plugin->cls->dataset_cls.get)(dset, get_type, dxpl_id, H5_REQUEST_NULL, arguments)) < 0)
         HGOTO_ERROR(H5E_VOL, H5E_CANTGET, FAIL, "get failed")
     va_end (arguments);
@@ -1158,7 +1158,7 @@ H5VL_dataset_get(void *dset, H5VL_t *vol_plugin, H5VL_dataset_get_t get_type,
     if(H5VL_DATASET_GET_TYPE == get_type) {
         hid_t           *ret_id;
 
-        va_start (arguments, event_q);
+        va_start (arguments, estack_id);
         ret_id = va_arg (arguments, hid_t *);
 
         if(H5Tcommitted(*ret_id)) {
@@ -1190,7 +1190,7 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5VL_dataset_close(void *dset, H5VL_t *vol_plugin, hid_t dxpl_id, hid_t UNUSED event_q)
+H5VL_dataset_close(void *dset, H5VL_t *vol_plugin, hid_t dxpl_id, hid_t UNUSED estack_id)
 {
     herr_t              ret_value = SUCCEED;
 
@@ -1201,7 +1201,7 @@ H5VL_dataset_close(void *dset, H5VL_t *vol_plugin, hid_t dxpl_id, hid_t UNUSED e
     if(NULL == vol_plugin->cls->dataset_cls.close){
         ;
 #if 0
-        if(H5VL_object_close(id, dxpl_id, dxpl_id, event_q) < 0)
+        if(H5VL_object_close(id, dxpl_id, dxpl_id, estack_id) < 0)
             HGOTO_ERROR(H5E_SYM, H5E_CANTRELEASE, FAIL, "unable to close object")
 #endif
     }
@@ -1237,7 +1237,7 @@ done:
  */
 void *
 H5VL_file_create(H5VL_t **plugin, const char *name, unsigned flags, hid_t fcpl_id, 
-                 hid_t fapl_id, hid_t dxpl_id, hid_t UNUSED event_q)
+                 hid_t fapl_id, hid_t dxpl_id, hid_t UNUSED estack_id)
 {
     H5P_genplist_t     *plist;                 /* Property list pointer */
     H5VL_class_t       *vol_cls;               /* VOL class attached to fapl_id */
@@ -1290,7 +1290,7 @@ done:
  */
 void *
 H5VL_file_open(H5VL_t **plugin, const char *name, unsigned flags, hid_t fapl_id, 
-               hid_t dxpl_id, hid_t UNUSED event_q)
+               hid_t dxpl_id, hid_t UNUSED estack_id)
 {
     H5P_genplist_t     *plist;                 /* Property list pointer */
     H5VL_class_t       *vol_cls;               /* VOL class attached to fapl_id */
@@ -1343,7 +1343,7 @@ done:
  */
 herr_t
 H5VL_file_flush(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, H5F_scope_t scope, 
-                hid_t dxpl_id, hid_t UNUSED event_q)
+                hid_t dxpl_id, hid_t UNUSED estack_id)
 {
     herr_t              ret_value = SUCCEED;
 
@@ -1375,7 +1375,7 @@ done:
  */
 herr_t
 H5VL_file_get(void *file, H5VL_t *vol_plugin, H5VL_file_get_t get_type, 
-              hid_t dxpl_id, hid_t event_q, ...)
+              hid_t dxpl_id, hid_t estack_id, ...)
 {
     va_list           arguments;             /* argument list passed from the API call */
     herr_t            ret_value = SUCCEED;
@@ -1385,7 +1385,7 @@ H5VL_file_get(void *file, H5VL_t *vol_plugin, H5VL_file_get_t get_type,
     if(NULL == vol_plugin->cls->file_cls.get)
 	HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "vol plugin has no `file get' method")
 
-    va_start(arguments, event_q);
+    va_start(arguments, estack_id);
     if((ret_value = (vol_plugin->cls->file_cls.get)(file, get_type, dxpl_id, H5_REQUEST_NULL, arguments)) < 0)
         HGOTO_ERROR(H5E_VOL, H5E_CANTGET, FAIL, "get failed")
     va_end(arguments);
@@ -1410,7 +1410,7 @@ done:
  */
 herr_t
 H5VL_file_misc(void *file, H5VL_t *vol_plugin, H5VL_file_misc_t misc_type, 
-               hid_t dxpl_id, hid_t event_q, ...)
+               hid_t dxpl_id, hid_t estack_id, ...)
 {
     va_list           arguments;             /* argument list passed from the API call */
     herr_t            ret_value = SUCCEED;
@@ -1423,7 +1423,7 @@ H5VL_file_misc(void *file, H5VL_t *vol_plugin, H5VL_file_misc_t misc_type,
         va_list             tmp_args;       /* argument list passed from the API call */
         hid_t               fapl_id;
 
-        va_start (tmp_args, event_q);
+        va_start (tmp_args, estack_id);
         fapl_id = va_arg (tmp_args, hid_t);
         va_end (tmp_args);
 
@@ -1433,7 +1433,7 @@ H5VL_file_misc(void *file, H5VL_t *vol_plugin, H5VL_file_misc_t misc_type,
         if(H5P_get(plist, H5F_ACS_VOL_NAME, &vol_cls) < 0)
             HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get vol plugin")
 
-        va_start (arguments, event_q);
+        va_start (arguments, estack_id);
         if((ret_value = (vol_cls->file_cls.misc)(file, misc_type, dxpl_id, H5_REQUEST_NULL, arguments)) < 0)
             HGOTO_ERROR(H5E_VOL, H5E_CANTGET, FAIL, "misc failed")
         va_end (arguments);
@@ -1442,7 +1442,7 @@ H5VL_file_misc(void *file, H5VL_t *vol_plugin, H5VL_file_misc_t misc_type,
         if(NULL == vol_plugin->cls->file_cls.misc)
             HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "vol plugin has no `file misc' method")
 
-        va_start (arguments, event_q);
+        va_start (arguments, estack_id);
         if((ret_value = (vol_plugin->cls->file_cls.misc)(file, misc_type, dxpl_id, H5_REQUEST_NULL, arguments)) < 0)
             HGOTO_ERROR(H5E_VOL, H5E_CANTGET, FAIL, "misc failed")
         va_end (arguments);
@@ -1468,7 +1468,7 @@ done:
  */
 herr_t
 H5VL_file_optional(void *file, H5VL_t *vol_plugin, H5VL_file_optional_t optional_type, 
-                   hid_t dxpl_id, hid_t event_q, ...)
+                   hid_t dxpl_id, hid_t estack_id, ...)
 {
     va_list           arguments;             /* argument list passed from the API call */
     herr_t            ret_value = SUCCEED;
@@ -1478,7 +1478,7 @@ H5VL_file_optional(void *file, H5VL_t *vol_plugin, H5VL_file_optional_t optional
     if(NULL == vol_plugin->cls->file_cls.optional)
 	HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "vol plugin has no `file optional' method")
 
-    va_start (arguments, event_q);
+    va_start (arguments, estack_id);
     if((ret_value = (vol_plugin->cls->file_cls.optional)(file, optional_type, dxpl_id, H5_REQUEST_NULL, arguments)) < 0)
         HGOTO_ERROR(H5E_VOL, H5E_CANTGET, FAIL, "optional failed")
     va_end (arguments);
@@ -1508,7 +1508,7 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5VL_file_close(void *file, H5VL_t *vol_plugin, hid_t dxpl_id, hid_t UNUSED event_q)
+H5VL_file_close(void *file, H5VL_t *vol_plugin, hid_t dxpl_id, hid_t UNUSED estack_id)
 {
     herr_t              ret_value = SUCCEED;
 
@@ -1546,7 +1546,7 @@ done:
  */
 void *
 H5VL_group_create(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, const char *name, 
-                  hid_t gcpl_id, hid_t gapl_id, hid_t dxpl_id, hid_t UNUSED event_q)
+                  hid_t gcpl_id, hid_t gapl_id, hid_t dxpl_id, hid_t UNUSED estack_id)
 {
     void *ret_value = NULL; /* Return value */
 
@@ -1581,7 +1581,7 @@ done:
  */
 void *
 H5VL_group_open(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, const char *name, 
-                hid_t gapl_id, hid_t dxpl_id, hid_t UNUSED event_q)
+                hid_t gapl_id, hid_t dxpl_id, hid_t UNUSED estack_id)
 {
     void *ret_value; /* Return value */
 
@@ -1592,7 +1592,7 @@ H5VL_group_open(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, con
         ;
 #if 0
         /* Open the object class */
-        if((ret_value = H5VL_object_open(id, loc_params, dxpl_id, event_q)) < 0)
+        if((ret_value = H5VL_object_open(id, loc_params, dxpl_id, estack_id)) < 0)
             HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, NULL, "unable to open object")
 #endif
     }
@@ -1623,7 +1623,7 @@ done:
  */
 herr_t
 H5VL_group_get(void *obj, H5VL_t *vol_plugin, H5VL_group_get_t get_type, 
-               hid_t dxpl_id, hid_t event_q, ...)
+               hid_t dxpl_id, hid_t estack_id, ...)
 {
     va_list           arguments;             /* argument list passed from the API call */
     herr_t            ret_value = SUCCEED;
@@ -1632,7 +1632,7 @@ H5VL_group_get(void *obj, H5VL_t *vol_plugin, H5VL_group_get_t get_type,
 
     if(NULL == vol_plugin->cls->group_cls.get)
 	HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "vol plugin has no `group get' method")
-    va_start (arguments, event_q);
+    va_start (arguments, estack_id);
     if((ret_value = (vol_plugin->cls->group_cls.get)(obj, get_type, dxpl_id, H5_REQUEST_NULL, arguments)) < 0)
         HGOTO_ERROR(H5E_VOL, H5E_CANTGET, FAIL, "get failed")
     va_end (arguments);
@@ -1657,7 +1657,7 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5VL_group_close(void *grp, H5VL_t *vol_plugin, hid_t dxpl_id, hid_t UNUSED event_q)
+H5VL_group_close(void *grp, H5VL_t *vol_plugin, hid_t dxpl_id, hid_t UNUSED estack_id)
 {
     herr_t              ret_value = SUCCEED;
 
@@ -1668,7 +1668,7 @@ H5VL_group_close(void *grp, H5VL_t *vol_plugin, hid_t dxpl_id, hid_t UNUSED even
     if(NULL == vol_plugin->cls->group_cls.close) {
         ;
 #if 0
-        if(H5VL_object_close(id, dxpl_id, event_q) < 0)
+        if(H5VL_object_close(id, dxpl_id, estack_id) < 0)
             HGOTO_ERROR(H5E_SYM, H5E_CANTRELEASE, FAIL, "unable to close object")
 #endif
     }
@@ -1702,7 +1702,7 @@ done:
  */
 herr_t
 H5VL_link_create(H5VL_link_create_type_t create_type, void *obj, H5VL_loc_params_t loc_params, 
-                 H5VL_t *vol_plugin, hid_t lcpl_id, hid_t lapl_id, hid_t dxpl_id, hid_t UNUSED event_q)
+                 H5VL_t *vol_plugin, hid_t lcpl_id, hid_t lapl_id, hid_t dxpl_id, hid_t UNUSED estack_id)
 {
     herr_t               ret_value = SUCCEED;  /* Return value */
 
@@ -1736,7 +1736,7 @@ done:
 herr_t 
 H5VL_link_move(void *src_obj, H5VL_loc_params_t loc_params1, void *dst_obj,
                H5VL_loc_params_t loc_params2, H5VL_t *vol_plugin, hbool_t copy_flag, 
-               hid_t lcpl_id, hid_t lapl_id, hid_t dxpl_id, hid_t UNUSED event_q)
+               hid_t lcpl_id, hid_t lapl_id, hid_t dxpl_id, hid_t UNUSED estack_id)
 {
     herr_t               ret_value = SUCCEED;  /* Return value */
 
@@ -1771,7 +1771,7 @@ done:
 herr_t 
 H5VL_link_iterate(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, 
                   hbool_t recursive, H5_index_t idx_type, H5_iter_order_t order, hsize_t *idx, 
-                  H5L_iterate_t op, void *op_data, hid_t dxpl_id, hid_t UNUSED event_q)
+                  H5L_iterate_t op, void *op_data, hid_t dxpl_id, hid_t UNUSED estack_id)
 {
     herr_t            ret_value = SUCCEED;
 
@@ -1804,7 +1804,7 @@ done:
  */
 herr_t
 H5VL_link_get(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, H5VL_link_get_t get_type, 
-              hid_t dxpl_id, hid_t event_q, ...)
+              hid_t dxpl_id, hid_t estack_id, ...)
 {
     va_list           arguments;             /* argument list passed from the API call */
     herr_t            ret_value = SUCCEED;
@@ -1813,7 +1813,7 @@ H5VL_link_get(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, H5VL_
 
     if(NULL == vol_plugin->cls->link_cls.get)
 	HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "vol plugin has no `link get' method")
-    va_start (arguments, event_q);
+    va_start (arguments, estack_id);
     if((ret_value = (vol_plugin->cls->link_cls.get)(obj, loc_params, get_type, dxpl_id, H5_REQUEST_NULL, arguments)) < 0)
         HGOTO_ERROR(H5E_VOL, H5E_CANTGET, FAIL, "get failed")
     va_end (arguments);
@@ -1837,7 +1837,7 @@ done:
  */
 herr_t 
 H5VL_link_remove(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, 
-                 hid_t dxpl_id, hid_t UNUSED event_q)
+                 hid_t dxpl_id, hid_t UNUSED estack_id)
 {
     herr_t             ret_value = SUCCEED;    /* Return value */
 
@@ -1871,7 +1871,7 @@ done:
  */
 void *
 H5VL_object_open(void *obj, H5VL_loc_params_t params, H5VL_t *vol_plugin, H5I_type_t *opened_type,
-                 hid_t dxpl_id, hid_t UNUSED event_q)
+                 hid_t dxpl_id, hid_t UNUSED estack_id)
 {
     void *ret_value;              /* Return value */
 
@@ -1906,7 +1906,7 @@ done:
 herr_t 
 H5VL_object_copy(void *src_obj, H5VL_loc_params_t loc_params1, H5VL_t *vol_plugin1, const char *src_name, 
                  void *dst_obj, H5VL_loc_params_t loc_params2, H5VL_t *vol_plugin2, const char *dst_name, 
-                 hid_t ocpypl_id, hid_t lcpl_id, hid_t dxpl_id, hid_t UNUSED event_q)
+                 hid_t ocpypl_id, hid_t lcpl_id, hid_t dxpl_id, hid_t UNUSED estack_id)
 {
     herr_t              ret_value = SUCCEED;
 
@@ -1942,7 +1942,7 @@ done:
  */
 herr_t H5VL_object_visit(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, 
                          H5_index_t idx_type, H5_iter_order_t order, H5O_iterate_t op, 
-                         void *op_data, hid_t dxpl_id, hid_t UNUSED event_q)
+                         void *op_data, hid_t dxpl_id, hid_t UNUSED estack_id)
 {
     herr_t            ret_value = SUCCEED;
 
@@ -1977,7 +1977,7 @@ done:
  */
 herr_t
 H5VL_object_lookup(hid_t id, H5VL_loc_type_t lookup_type, void **location, 
-                   hid_t dxpl_id, hid_t event_q, ...)
+                   hid_t dxpl_id, hid_t estack_id, ...)
 {
     va_list           arguments;             /* argument list passed from the API call */
     H5VL_class_t      *vol_plugin;            /* VOL structure attached to id */
@@ -1991,7 +1991,7 @@ H5VL_object_lookup(hid_t id, H5VL_loc_type_t lookup_type, void **location,
     if(NULL == vol_plugin->object_cls.lookup)
 	HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "vol plugin has no `object lookup' method")
 
-    va_start (arguments, event_q);
+    va_start (arguments, estack_id);
     if((ret_value = (vol_plugin->object_cls.lookup)(id, lookup_type, location, dxpl_id, H5_REQUEST_NULL, arguments)) < 0)
         HGOTO_ERROR(H5E_VOL, H5E_CANTGET, FAIL, "lookup of object location failed")
     va_end (arguments);
@@ -2014,7 +2014,7 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5VL_object_free_loc(hid_t id, void *location, hid_t dxpl_id, hid_t UNUSED event_q)
+H5VL_object_free_loc(hid_t id, void *location, hid_t dxpl_id, hid_t UNUSED estack_id)
 {
     H5VL_class_t       *vol_plugin;            /* VOL structure attached to id */
     herr_t            ret_value = SUCCEED;
@@ -2052,7 +2052,7 @@ done:
  */
 herr_t
 H5VL_object_get(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, H5VL_object_get_t get_type, 
-                hid_t dxpl_id, hid_t event_q, ...)
+                hid_t dxpl_id, hid_t estack_id, ...)
 {
     va_list           arguments;             /* argument list passed from the API call */
     herr_t            ret_value = SUCCEED;
@@ -2062,7 +2062,7 @@ H5VL_object_get(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, H5V
     if(NULL == vol_plugin->cls->object_cls.get)
 	HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "vol plugin has no `object get' method")
 
-    va_start (arguments, event_q);
+    va_start (arguments, estack_id);
     if((ret_value = (vol_plugin->cls->object_cls.get)(obj, loc_params, get_type, dxpl_id, H5_REQUEST_NULL, arguments)) < 0)
         HGOTO_ERROR(H5E_VOL, H5E_CANTGET, FAIL, "get failed")
     va_end (arguments);
@@ -2086,7 +2086,7 @@ done:
  */
 herr_t
 H5VL_object_misc(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, H5VL_object_misc_t misc_type, 
-                 hid_t dxpl_id, hid_t event_q, ...)
+                 hid_t dxpl_id, hid_t estack_id, ...)
 {
     va_list           arguments;             /* argument list passed from the API call */
     herr_t            ret_value = SUCCEED;
@@ -2096,7 +2096,7 @@ H5VL_object_misc(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, H5
     if(NULL == vol_plugin->cls->object_cls.misc)
 	HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "vol plugin has no `object misc' method")
 
-    va_start (arguments, event_q);
+    va_start (arguments, estack_id);
     if((ret_value = (vol_plugin->cls->object_cls.misc)(obj, loc_params, misc_type, dxpl_id, H5_REQUEST_NULL, arguments)) < 0)
         HGOTO_ERROR(H5E_VOL, H5E_CANTGET, FAIL, "misc failed")
     va_end (arguments);
@@ -2122,7 +2122,7 @@ done:
  */
 herr_t
 H5VL_object_close(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, 
-                  hid_t dxpl_id, hid_t UNUSED event_q)
+                  hid_t dxpl_id, hid_t UNUSED estack_id)
 {
     herr_t              ret_value = SUCCEED;
 
@@ -2152,7 +2152,7 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5VL_request_cancel(void **req, H5VL_t *vol_plugin, H5_status_t *status)
+H5VL_request_cancel(void **req, H5VL_t *vol_plugin, H5ES_status_t *status)
 {
     herr_t              ret_value = SUCCEED;
 
@@ -2182,7 +2182,7 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5VL_request_test(void **req, H5VL_t *vol_plugin, H5_status_t *status)
+H5VL_request_test(void **req, H5VL_t *vol_plugin, H5ES_status_t *status)
 {
     herr_t              ret_value = SUCCEED;
 
@@ -2212,7 +2212,7 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5VL_request_wait(void **req, H5VL_t *vol_plugin, H5_status_t *status)
+H5VL_request_wait(void **req, H5VL_t *vol_plugin, H5ES_status_t *status)
 {
     herr_t              ret_value = SUCCEED;
 
diff --git a/src/H5VLprivate.h b/src/H5VLprivate.h
index 0e1b596..33f3f5a 100644
--- a/src/H5VLprivate.h
+++ b/src/H5VLprivate.h
@@ -30,7 +30,7 @@
 /* Library Private Typedefs */
 /****************************/
 #define H5_REQUEST_NULL NULL
-#define H5_EVENT_QUEUE_NULL -1
+#define H5_EVENT_STACK_NULL -1
 
 /*****************************/
 /* Library Private Variables */
@@ -52,69 +52,69 @@ H5_DLL ssize_t H5VL_get_plugin_name(hid_t id, char *name/*out*/, size_t size);
 H5_DLL void *H5VL_get_object(hid_t id);
 H5_DLL herr_t H5VL_close(H5VL_class_t *vol_plugin);
 
-H5_DLL void *H5VL_attr_create(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, const char *attr_name, hid_t acpl_id, hid_t aapl_id, hid_t dxpl_id, hid_t event_q);
-H5_DLL void *H5VL_attr_open(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, const char *name, hid_t aapl_id, hid_t dxpl_id, hid_t event_q);
-H5_DLL herr_t H5VL_attr_read(void *attr, H5VL_t *vol_plugin, hid_t dtype_id, void *buf, hid_t dxpl_id, hid_t event_q);
-H5_DLL herr_t H5VL_attr_write(void *attr, H5VL_t *vol_plugin, hid_t dtype_id, const void *buf, hid_t dxpl_id, hid_t event_q);
+H5_DLL void *H5VL_attr_create(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, const char *attr_name, hid_t acpl_id, hid_t aapl_id, hid_t dxpl_id, hid_t estack_id);
+H5_DLL void *H5VL_attr_open(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, const char *name, hid_t aapl_id, hid_t dxpl_id, hid_t estack_id);
+H5_DLL herr_t H5VL_attr_read(void *attr, H5VL_t *vol_plugin, hid_t dtype_id, void *buf, hid_t dxpl_id, hid_t estack_id);
+H5_DLL herr_t H5VL_attr_write(void *attr, H5VL_t *vol_plugin, hid_t dtype_id, const void *buf, hid_t dxpl_id, hid_t estack_id);
 H5_DLL herr_t H5VL_attr_iterate(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, 
                                 H5_index_t idx_type, H5_iter_order_t order, hsize_t *n, 
-                                H5A_operator2_t op, void *op_data, hid_t dxpl_id, hid_t event_q);
-H5_DLL herr_t H5VL_attr_get(void *attr, H5VL_t *vol_plugin, H5VL_attr_get_t get_type, hid_t dxpl_id, hid_t event_q, ...);
-H5_DLL herr_t H5VL_attr_remove(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin,  const char *attr_name, hid_t dxpl_id, hid_t event_q);
-H5_DLL herr_t H5VL_attr_close(void *attr, H5VL_t *vol_plugin, hid_t dxpl_id, hid_t event_q);
-
-H5_DLL void *H5VL_dataset_create(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, const char *name, hid_t dcpl_id, hid_t dapl_id, hid_t dxpl_id, hid_t event_q);
-H5_DLL void *H5VL_dataset_open(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, const char *name, hid_t dapl_id, hid_t dxpl_id, hid_t event_q);
-H5_DLL herr_t H5VL_dataset_read(void *dset, H5VL_t *vol_plugin, hid_t mem_type_id, hid_t mem_space_id, hid_t file_space_id, hid_t plist_id, void *buf, hid_t event_q);
-H5_DLL herr_t H5VL_dataset_write(void *dset, H5VL_t *vol_plugin, hid_t mem_type_id, hid_t mem_space_id, hid_t file_space_id, hid_t plist_id, const void *buf, hid_t event_q);
-H5_DLL herr_t H5VL_dataset_set_extent(void *dset, H5VL_t *vol_plugin, const hsize_t size[], hid_t dxpl_id, hid_t event_q);
-H5_DLL herr_t H5VL_dataset_get(void *dset, H5VL_t *vol_plugin, H5VL_dataset_get_t get_type, hid_t dxpl_id, hid_t event_q, ...);
-H5_DLL herr_t H5VL_dataset_close(void *dset, H5VL_t *vol_plugin, hid_t dxpl_id, hid_t event_q);
-
-H5_DLL void *H5VL_datatype_commit(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, const char *name, hid_t type_id, hid_t lcpl_id, hid_t tcpl_id, hid_t tapl_id, hid_t dxpl_id, hid_t event_q);
-H5_DLL void *H5VL_datatype_open(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, const char *name, hid_t tapl_id, hid_t dxpl_id, hid_t event_q);
-H5_DLL ssize_t H5VL_datatype_get_binary(void *obj, H5VL_t *vol_plugin, unsigned char *buf, size_t size, hid_t dxpl_id, hid_t event_q);
-H5_DLL herr_t H5VL_datatype_get(void *dt, H5VL_t *vol_plugin, H5VL_datatype_get_t get_type, hid_t dxpl_id, hid_t event_q, ...);
-H5_DLL herr_t H5VL_datatype_close(void *dt, H5VL_t *vol_plugin, hid_t dxpl_id, hid_t event_q);
-
-H5_DLL void *H5VL_file_create(H5VL_t **vol_plugin, const char *name, unsigned flags, hid_t fcpl_id, hid_t fapl_id, hid_t dxpl_id, hid_t event_q);
-H5_DLL void *H5VL_file_open(H5VL_t **vol_plugin, const char *name, unsigned flags, hid_t fapl_id, hid_t dxpl_id, hid_t event_q);
-H5_DLL herr_t H5VL_file_flush(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, H5F_scope_t scope, hid_t dxpl_id, hid_t event_q);
-H5_DLL herr_t H5VL_file_misc(void *file, H5VL_t *vol_plugin, H5VL_file_misc_t misc_type, hid_t dxpl_id, hid_t event_q, ...);
-H5_DLL herr_t H5VL_file_optional(void *file, H5VL_t *vol_plugin, H5VL_file_optional_t optional_type, hid_t dxpl_id, hid_t event_q, ...);
-H5_DLL herr_t H5VL_file_get(void *file, H5VL_t *vol_plugin, H5VL_file_get_t get_type, hid_t dxpl_id, hid_t event_q, ...);
-H5_DLL herr_t H5VL_file_close(void *file, H5VL_t *vol_plugin, hid_t dxpl_id, hid_t event_q);
-
-H5_DLL void *H5VL_group_create(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, const char *name, hid_t gcpl_id, hid_t gapl_id, hid_t dxpl_id, hid_t event_q);
-H5_DLL void *H5VL_group_open(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, const char *name, hid_t gapl_id, hid_t dxpl_id, hid_t event_q);
-H5_DLL herr_t H5VL_group_close(void *grp, H5VL_t *vol_plugin, hid_t dxpl_id, hid_t event_q);
-H5_DLL herr_t H5VL_group_get(void *obj, H5VL_t *vol_plugin, H5VL_group_get_t get_type, hid_t dxpl_id, hid_t event_q, ...);
-
-H5_DLL herr_t H5VL_link_create(H5VL_link_create_type_t create_type, void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, hid_t lcpl_id, hid_t lapl_id, hid_t dxpl_id, hid_t event_q);
+                                H5A_operator2_t op, void *op_data, hid_t dxpl_id, hid_t estack_id);
+H5_DLL herr_t H5VL_attr_get(void *attr, H5VL_t *vol_plugin, H5VL_attr_get_t get_type, hid_t dxpl_id, hid_t estack_id, ...);
+H5_DLL herr_t H5VL_attr_remove(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin,  const char *attr_name, hid_t dxpl_id, hid_t estack_id);
+H5_DLL herr_t H5VL_attr_close(void *attr, H5VL_t *vol_plugin, hid_t dxpl_id, hid_t estack_id);
+
+H5_DLL void *H5VL_dataset_create(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, const char *name, hid_t dcpl_id, hid_t dapl_id, hid_t dxpl_id, hid_t estack_id);
+H5_DLL void *H5VL_dataset_open(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, const char *name, hid_t dapl_id, hid_t dxpl_id, hid_t estack_id);
+H5_DLL herr_t H5VL_dataset_read(void *dset, H5VL_t *vol_plugin, hid_t mem_type_id, hid_t mem_space_id, hid_t file_space_id, hid_t plist_id, void *buf, hid_t estack_id);
+H5_DLL herr_t H5VL_dataset_write(void *dset, H5VL_t *vol_plugin, hid_t mem_type_id, hid_t mem_space_id, hid_t file_space_id, hid_t plist_id, const void *buf, hid_t estack_id);
+H5_DLL herr_t H5VL_dataset_set_extent(void *dset, H5VL_t *vol_plugin, const hsize_t size[], hid_t dxpl_id, hid_t estack_id);
+H5_DLL herr_t H5VL_dataset_get(void *dset, H5VL_t *vol_plugin, H5VL_dataset_get_t get_type, hid_t dxpl_id, hid_t estack_id, ...);
+H5_DLL herr_t H5VL_dataset_close(void *dset, H5VL_t *vol_plugin, hid_t dxpl_id, hid_t estack_id);
+
+H5_DLL void *H5VL_datatype_commit(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, const char *name, hid_t type_id, hid_t lcpl_id, hid_t tcpl_id, hid_t tapl_id, hid_t dxpl_id, hid_t estack_id);
+H5_DLL void *H5VL_datatype_open(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, const char *name, hid_t tapl_id, hid_t dxpl_id, hid_t estack_id);
+H5_DLL ssize_t H5VL_datatype_get_binary(void *obj, H5VL_t *vol_plugin, unsigned char *buf, size_t size, hid_t dxpl_id, hid_t estack_id);
+H5_DLL herr_t H5VL_datatype_get(void *dt, H5VL_t *vol_plugin, H5VL_datatype_get_t get_type, hid_t dxpl_id, hid_t estack_id, ...);
+H5_DLL herr_t H5VL_datatype_close(void *dt, H5VL_t *vol_plugin, hid_t dxpl_id, hid_t estack_id);
+
+H5_DLL void *H5VL_file_create(H5VL_t **vol_plugin, const char *name, unsigned flags, hid_t fcpl_id, hid_t fapl_id, hid_t dxpl_id, hid_t estack_id);
+H5_DLL void *H5VL_file_open(H5VL_t **vol_plugin, const char *name, unsigned flags, hid_t fapl_id, hid_t dxpl_id, hid_t estack_id);
+H5_DLL herr_t H5VL_file_flush(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, H5F_scope_t scope, hid_t dxpl_id, hid_t estack_id);
+H5_DLL herr_t H5VL_file_misc(void *file, H5VL_t *vol_plugin, H5VL_file_misc_t misc_type, hid_t dxpl_id, hid_t estack_id, ...);
+H5_DLL herr_t H5VL_file_optional(void *file, H5VL_t *vol_plugin, H5VL_file_optional_t optional_type, hid_t dxpl_id, hid_t estack_id, ...);
+H5_DLL herr_t H5VL_file_get(void *file, H5VL_t *vol_plugin, H5VL_file_get_t get_type, hid_t dxpl_id, hid_t estack_id, ...);
+H5_DLL herr_t H5VL_file_close(void *file, H5VL_t *vol_plugin, hid_t dxpl_id, hid_t estack_id);
+
+H5_DLL void *H5VL_group_create(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, const char *name, hid_t gcpl_id, hid_t gapl_id, hid_t dxpl_id, hid_t estack_id);
+H5_DLL void *H5VL_group_open(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, const char *name, hid_t gapl_id, hid_t dxpl_id, hid_t estack_id);
+H5_DLL herr_t H5VL_group_close(void *grp, H5VL_t *vol_plugin, hid_t dxpl_id, hid_t estack_id);
+H5_DLL herr_t H5VL_group_get(void *obj, H5VL_t *vol_plugin, H5VL_group_get_t get_type, hid_t dxpl_id, hid_t estack_id, ...);
+
+H5_DLL herr_t H5VL_link_create(H5VL_link_create_type_t create_type, void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, hid_t lcpl_id, hid_t lapl_id, hid_t dxpl_id, hid_t estack_id);
 H5_DLL herr_t H5VL_link_move(void *src_obj, H5VL_loc_params_t loc_params1,
                              void *dst_obj, H5VL_loc_params_t loc_params2, H5VL_t *vol_plugin,
-                             hbool_t copy_flag, hid_t lcpl_id, hid_t lapl_id, hid_t dxpl_id, hid_t event_q);
+                             hbool_t copy_flag, hid_t lcpl_id, hid_t lapl_id, hid_t dxpl_id, hid_t estack_id);
 H5_DLL herr_t H5VL_link_iterate(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, 
                                 hbool_t recursive, H5_index_t idx_type, H5_iter_order_t order, 
-                                hsize_t *idx, H5L_iterate_t op, void *op_data, hid_t dxpl_id, hid_t event_q);
-H5_DLL herr_t H5VL_link_get(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, H5VL_link_get_t get_type, hid_t dxpl_id, hid_t event_q, ...);
-H5_DLL herr_t H5VL_link_remove(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, hid_t dxpl_id, hid_t event_q);
+                                hsize_t *idx, H5L_iterate_t op, void *op_data, hid_t dxpl_id, hid_t estack_id);
+H5_DLL herr_t H5VL_link_get(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, H5VL_link_get_t get_type, hid_t dxpl_id, hid_t estack_id, ...);
+H5_DLL herr_t H5VL_link_remove(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, hid_t dxpl_id, hid_t estack_id);
 
-H5_DLL void *H5VL_object_open(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, H5I_type_t *opened_type, hid_t dxpl_id, hid_t event_q);
+H5_DLL void *H5VL_object_open(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, H5I_type_t *opened_type, hid_t dxpl_id, hid_t estack_id);
 H5_DLL herr_t H5VL_object_copy(void *src_obj, H5VL_loc_params_t loc_params1, H5VL_t *vol_plugin1, const char *src_name, 
                                void *dst_obj, H5VL_loc_params_t loc_params2, H5VL_t *vol_plugin2, const char *dst_name, 
-                               hid_t ocpypl_id, hid_t lcpl_id, hid_t dxpl_id, hid_t event_q);
-H5_DLL herr_t H5VL_object_visit(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, H5_index_t idx_type, H5_iter_order_t order, H5O_iterate_t op, void *op_data, hid_t dxpl_id, hid_t event_q);
-H5_DLL herr_t H5VL_object_get(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, H5VL_object_get_t get_type, hid_t dxpl_id, hid_t event_q, ...);
-H5_DLL herr_t H5VL_object_misc(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, H5VL_object_misc_t misc_type, hid_t dxpl_id, hid_t event_q, ...);
-H5_DLL herr_t H5VL_object_optional(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, H5VL_object_misc_t optional_type, hid_t dxpl_id, hid_t event_q, ...);
-//H5_DLL herr_t H5VL_object_lookup(hid_t uid, H5VL_loc_type_t lookup_type, void **location, hid_t dxpl_id, hid_t event_q, ...);
-//H5_DLL herr_t H5VL_object_free_loc(hid_t loc_id, void *location, hid_t dxpl_id, hid_t event_q);
-H5_DLL herr_t H5VL_object_close(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, hid_t dxpl_id, hid_t event_q);
-
-H5_DLL herr_t H5VL_request_cancel(void **req, H5VL_t *vol_plugin, H5_status_t *status);
-H5_DLL herr_t H5VL_request_test(void **req, H5VL_t *vol_plugin, H5_status_t *status);
-H5_DLL herr_t H5VL_request_wait(void **req, H5VL_t *vol_plugin, H5_status_t *status);
+                               hid_t ocpypl_id, hid_t lcpl_id, hid_t dxpl_id, hid_t estack_id);
+H5_DLL herr_t H5VL_object_visit(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, H5_index_t idx_type, H5_iter_order_t order, H5O_iterate_t op, void *op_data, hid_t dxpl_id, hid_t estack_id);
+H5_DLL herr_t H5VL_object_get(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, H5VL_object_get_t get_type, hid_t dxpl_id, hid_t estack_id, ...);
+H5_DLL herr_t H5VL_object_misc(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, H5VL_object_misc_t misc_type, hid_t dxpl_id, hid_t estack_id, ...);
+H5_DLL herr_t H5VL_object_optional(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, H5VL_object_misc_t optional_type, hid_t dxpl_id, hid_t estack_id, ...);
+//H5_DLL herr_t H5VL_object_lookup(hid_t uid, H5VL_loc_type_t lookup_type, void **location, hid_t dxpl_id, hid_t estack_id, ...);
+//H5_DLL herr_t H5VL_object_free_loc(hid_t loc_id, void *location, hid_t dxpl_id, hid_t estack_id);
+H5_DLL herr_t H5VL_object_close(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, hid_t dxpl_id, hid_t estack_id);
+
+H5_DLL herr_t H5VL_request_cancel(void **req, H5VL_t *vol_plugin, H5ES_status_t *status);
+H5_DLL herr_t H5VL_request_test(void **req, H5VL_t *vol_plugin, H5ES_status_t *status);
+H5_DLL herr_t H5VL_request_wait(void **req, H5VL_t *vol_plugin, H5ES_status_t *status);
 
 H5_DLL herr_t H5VL_fapl_open(struct H5P_genplist_t *plist, H5VL_class_t *vol_cls, const void *vol_info);
 H5_DLL herr_t H5VL_fapl_copy(H5VL_class_t *vol_cls, const void *vol_info, void **copied_info);
diff --git a/src/H5VLpublic.h b/src/H5VLpublic.h
index fa23ce9..1171811 100644
--- a/src/H5VLpublic.h
+++ b/src/H5VLpublic.h
@@ -30,12 +30,12 @@
 #include "H5Rpublic.h"
 
 /* Asynchronous operation status */
-typedef enum {
-    H5AO_PENDING,       /* Operation has not yet completed */
-    H5AO_SUCCEEDED,     /* Operation has completed, successfully */
-    H5AO_FAILED,        /* Operation has completed, but failed */
-    H5AO_CANCELLED      /* Operation has no completed and has been cancelled */
-} H5_status_t;
+typedef enum H5ES_status_t {
+    H5ES_STATUS_IN_PROGRESS,   /* Operation has not yet completed */
+    H5ES_STATUS_SUCCEED,       /* Operation has completed, successfully */
+    H5ES_STATUS_FAIL,          /* Operation has completed, but failed */
+    H5ES_STATUS_CANCEL         /* Operation has not completed and has been cancelled */
+} H5ES_status_t;
 
 /* Dataset creation property names */
 #define H5VL_DSET_TYPE_ID        "dataset_type_id"
@@ -303,9 +303,9 @@ typedef struct H5VL_object_class_t {
 
 /* H5AO routines */
 typedef struct H5VL_async_class_t {
-    herr_t (*cancel)(void **, H5_status_t *);
-    herr_t (*test)  (void **, H5_status_t *);
-    herr_t (*wait)  (void **, H5_status_t *);
+    herr_t (*cancel)(void **, H5ES_status_t *);
+    herr_t (*test)  (void **, H5ES_status_t *);
+    herr_t (*wait)  (void **, H5ES_status_t *);
 } H5VL_async_class_t;
 
 /* enum value to identify the class of a VOL plugin (mostly for comparison purposes) */
@@ -413,9 +413,9 @@ H5_DLL herr_t H5VLobject_misc(void *obj, H5VL_loc_params_t loc_params, H5VL_t *v
 H5_DLL herr_t H5VLobject_optional(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, H5VL_object_misc_t optional_type, hid_t dxpl_id, void **req, va_list arguments);
 H5_DLL herr_t H5VLobject_close(void *obj, H5VL_loc_params_t loc_params, H5VL_t *vol_plugin, hid_t dxpl_id, void **req);
 
-H5_DLL herr_t H5VLrequest_cancel(void **req, H5VL_t *vol_plugin, H5_status_t *status);
-H5_DLL herr_t H5VLrequest_test(void **req, H5VL_t *vol_plugin, H5_status_t *status);
-H5_DLL herr_t H5VLrequest_wait(void **req, H5VL_t *vol_plugin, H5_status_t *status);
+H5_DLL herr_t H5VLrequest_cancel(void **req, H5VL_t *vol_plugin, H5ES_status_t *status);
+H5_DLL herr_t H5VLrequest_test(void **req, H5VL_t *vol_plugin, H5ES_status_t *status);
+H5_DLL herr_t H5VLrequest_wait(void **req, H5VL_t *vol_plugin, H5ES_status_t *status);
 
 /* Function prototypes */
 H5_DLL hid_t H5VLregister(const H5VL_class_t *cls);