Mega-commit to make heap_open/heap_openr/heap_close take an

additional argument specifying the kind of lock to acquire/release (or
'NoLock' to do no lock processing).  Ensure that all relations are locked
with some appropriate lock level before being examined --- this ensures
that relevant shared-inval messages have been processed and should prevent
problems caused by concurrent VACUUM.  Fix several bugs having to do with
mismatched increment/decrement of relation ref count and mismatched
heap_open/close (which amounts to the same thing).  A bogus ref count on
a relation doesn't matter much *unless* a SI Inval message happens to
arrive at the wrong time, which is probably why we got away with this
sloppiness for so long.  Repair missing grab of AccessExclusiveLock in
DROP TABLE, ALTER/RENAME TABLE, etc, as noted by Hiroshi.
Recommend 'make clean all' after pulling this update; I modified the
Relation struct layout slightly.
Will post further discussion to pghackers list shortly.

1 files changed, 18 insertions, 11 deletions

diff --git a/src/backend/bootstrap/bootstrap.c b/src/backend/bootstrap/bootstrap.c
index 8db37d0a081..18d9567ab89 100644
--- a/src/backend/bootstrap/bootstrap.c
+++ b/src/backend/bootstrap/bootstrap.c
@@ -7,7 +7,7 @@
  * Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/bootstrap/bootstrap.c,v 1.66 1999/07/19 02:27:04 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/bootstrap/bootstrap.c,v 1.67 1999/09/18 19:06:27 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -396,7 +396,8 @@ boot_openrel(char *relname)
 	if (Typ == (struct typmap **) NULL)
 	{
 		StartPortalAllocMode(DefaultAllocMode, 0);
-		rel = heap_openr(TypeRelationName);
+		rel = heap_openr(TypeRelationName, NoLock);
+		Assert(rel);
 		scan = heap_beginscan(rel, 0, SnapshotNow, 0, (ScanKey) NULL);
 		i = 0;
 		while (HeapTupleIsValid(tup = heap_getnext(scan, 0)))
@@ -416,7 +417,7 @@ boot_openrel(char *relname)
 					sizeof((*app)->am_typ));
 		}
 		heap_endscan(scan);
-		heap_close(rel);
+		heap_close(rel, NoLock);
 		EndPortalAllocMode();
 	}
 
@@ -427,7 +428,7 @@ boot_openrel(char *relname)
 		printf("Amopen: relation %s. attrsize %d\n", relname ? relname : "(null)",
 			   (int) ATTRIBUTE_TUPLE_SIZE);
 
-	reldesc = heap_openr(relname);
+	reldesc = heap_openr(relname, NoLock);
 	Assert(reldesc);
 	numattr = reldesc->rd_rel->relnatts;
 	for (i = 0; i < numattr; i++)
@@ -490,7 +491,7 @@ closerel(char *name)
 	{
 		if (!Quiet)
 			printf("Amclose: relation %s.\n", relname ? relname : "(null)");
-		heap_close(reldesc);
+		heap_close(reldesc, NoLock);
 		reldesc = (Relation) NULL;
 	}
 }
@@ -737,7 +738,7 @@ cleanup()
 		proc_exit(1);
 	}
 	if (reldesc != (Relation) NULL)
-		heap_close(reldesc);
+		heap_close(reldesc, NoLock);
 	CommitTransactionCommand();
 	proc_exit(Warnings);
 }
@@ -775,7 +776,8 @@ gettype(char *type)
 		}
 		if (DebugMode)
 			printf("bootstrap.c: External Type: %s\n", type);
-		rel = heap_openr(TypeRelationName);
+		rel = heap_openr(TypeRelationName, NoLock);
+		Assert(rel);
 		scan = heap_beginscan(rel, 0, SnapshotNow, 0, (ScanKey) NULL);
 		i = 0;
 		while (HeapTupleIsValid(tup = heap_getnext(scan, 0)))
@@ -795,7 +797,7 @@ gettype(char *type)
 					sizeof((*app)->am_typ));
 		}
 		heap_endscan(scan);
-		heap_close(rel);
+		heap_close(rel, NoLock);
 		return gettype(type);
 	}
 	elog(ERROR, "Error: unknown type '%s'.\n", type);
@@ -1106,11 +1108,16 @@ build_indices()
 
 	for (; ILHead != (IndexList *) NULL; ILHead = ILHead->il_next)
 	{
-		heap = heap_openr(ILHead->il_heap);
+		heap = heap_openr(ILHead->il_heap, NoLock);
+		Assert(heap);
 		ind = index_openr(ILHead->il_ind);
+		Assert(ind);
 		index_build(heap, ind, ILHead->il_natts, ILHead->il_attnos,
 				 ILHead->il_nparams, ILHead->il_params, ILHead->il_finfo,
 					ILHead->il_predInfo);
+		/* In normal processing mode, index_build would close the heap
+		 * and index, but in bootstrap mode it will not.
+		 */
 
 		/*
 		 * All of the rest of this routine is needed only because in
@@ -1128,9 +1135,9 @@ build_indices()
 		 *
 		 * -mer
 		 */
-		heap = heap_openr(ILHead->il_heap);
-
 		if (!BootstrapAlreadySeen(RelationGetRelid(heap)))
 			UpdateStats(RelationGetRelid(heap), 0, true);
+
+		/* XXX Probably we ought to close the heap and index here? */
 	}
 }