Fix a tiny memory leak (one List header) in RelationCacheInvalidate().

This is utterly insignificant in normal operation, but it becomes a
problem during cache inval stress testing.  The original coding in fact
had no leak --- the 8.0 List rewrite created the issue.  I wonder whether
list_concat should pfree the discarded header?

diff --git a/src/backend/utils/cache/relcache.c b/src/backend/utils/cache/relcache.c
index 06a75ffcaf9f4f6e12657db556224704999f0743..459014bd93062733f8a8f7bd4fe67ab9fdfc57cf 100644 (file)
--- a/src/backend/utils/cache/relcache.c
+++ b/src/backend/utils/cache/relcache.c
@@ -1786,8 +1786,6 @@ RelationCacheInvalidate(void)
                }
        }
 
-       rebuildList = list_concat(rebuildFirstList, rebuildList);
-
        /*
         * Now zap any remaining smgr cache entries.  This must happen before we
         * start to rebuild entries, since that may involve catalog fetches which
@@ -1796,6 +1794,12 @@ RelationCacheInvalidate(void)
        smgrcloseall();
 
        /* Phase 2: rebuild the items found to need rebuild in phase 1 */
+       foreach(l, rebuildFirstList)
+       {
+               relation = (Relation) lfirst(l);
+               RelationClearRelation(relation, true);
+       }
+       list_free(rebuildFirstList);
        foreach(l, rebuildList)
        {
                relation = (Relation) lfirst(l);