Ensure that catcache 'busy' flags are reset at transaction abort.

Without this, an elog during cache-entry load leaves that catcache
unusable.  elog in that segment of code is pretty unusual but it can
happen.

src/backend/access/transam/xact.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/access/transam/xact.c,v 1.69 2000/07/02 02:28:38 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/access/transam/xact.c,v 1.70 2000/08/06 04:17:47 tgl Exp $
  *
  * NOTES
  *		Transaction aborts can now occur two ways:
@@ -167,6 +167,7 @@
 #include "utils/inval.h"
 #include "utils/memutils.h"
 #include "utils/portal.h"
+#include "utils/catcache.h"
 #include "utils/relcache.h"
 #include "utils/temprel.h"
 
@@ -797,6 +798,7 @@ static void
 AtAbort_Cache()
 {
 	RelationCacheAbort();
+	SystemCacheAbort();
 	RegisterInvalid(false);
 }
 

src/backend/utils/cache/catcache.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/utils/cache/catcache.c,v 1.69 2000/07/02 05:38:40 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/utils/cache/catcache.c,v 1.70 2000/08/06 04:17:16 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -506,6 +506,7 @@ CatalogCacheIdInvalidate(int cacheId,	/* XXX */
  *					   public functions
  *
  *		ResetSystemCache
+ *		SystemCacheAbort
  *		InitIndexedSysCache
  *		InitSysCache
  *		SearchSysCache
@@ -517,7 +518,7 @@ CatalogCacheIdInvalidate(int cacheId,	/* XXX */
  * --------------------------------
  */
 void
-ResetSystemCache()
+ResetSystemCache(void)
 {
 	CatCache *cache;
 
@@ -545,18 +546,43 @@ ResetSystemCache()
 			{
 				nextelt = DLGetSucc(elt);
 				CatCacheRemoveCTup(cache, elt);
-				if (cache->cc_ntup < 0)
-					elog(NOTICE,
-						 "ResetSystemCache: cc_ntup<0 (software error)");
 			}
 		}
-		cache->cc_ntup = 0;		/* in case of WARN error above */
-		cache->busy = false;	/* to recover from recursive-use error */
+
+		/* double-check that ntup is now zero */
+		if (cache->cc_ntup != 0)
+		{
+			elog(NOTICE,
+				 "ResetSystemCache: cache %d has cc_ntup = %d, should be 0",
+				 cache->id, cache->cc_ntup);
+			cache->cc_ntup = 0;
+		}
 	}
 
 	CACHE1_elog(DEBUG, "end of ResetSystemCache call");
 }
 
+/* --------------------------------
+ *		SystemCacheAbort
+ *
+ * This routine is called to clean up catcache state as needed during
+ * transaction abort.
+ * --------------------------------
+ */
+void
+SystemCacheAbort(void)
+{
+	CatCache *cache;
+
+	/* ----------------
+	 *	clear the "cache busy" flags, which may have been left set if we
+	 *	elog'd out during a cache lookup attempt.
+	 * ----------------
+	 */
+	for (cache = Caches; PointerIsValid(cache); cache = cache->cc_next)
+		cache->busy = false;
+}
+
 /* --------------------------------
  *		SystemCacheRelationFlushed
  *

src/include/utils/catcache.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: catcache.h,v 1.25 2000/06/28 03:33:33 tgl Exp $
+ * $Id: catcache.h,v 1.26 2000/08/06 04:16:40 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -83,6 +83,7 @@ extern void CatalogCacheIdInvalidate(int cacheId, Index hashIndex,
 						 ItemPointer pointer);
 extern void ResetSystemCache(void);
 extern void SystemCacheRelationFlushed(Oid relId);
+extern void SystemCacheAbort(void);
 extern CatCache *InitSysCache(char *relname, char *indname, int id,
 							  int nkeys, int *key,
 							  ScanFunc iScanfuncP);