Initial MVCC code.

New code for locking buffer' context.

Author: vadim4o

src/backend/access/gist/gist.c

@@ -104,8 +104,7 @@ gistbuild(Relation heap,
 	Buffer		buffer = InvalidBuffer;
 	bool	   *compvec;
 
-	/* GiSTs only know how to do stupid locking now */
-	RelationSetLockForWrite(index);
+	/* no locking is needed */
 
 	setheapoverride(true);		/* so we can see the new pg_index tuple */
 	initGISTstate(&giststate, index);
@@ -269,7 +268,6 @@ gistbuild(Relation heap,
 
 	/* okay, all heap tuples are indexed */
 	heap_endscan(scan);
-	RelationUnsetLockForWrite(index);
 
 	if (pred != NULL || oldPred != NULL)
 	{
@@ -343,15 +341,19 @@ gistinsert(Relation r, Datum *datum, char *nulls, ItemPointer ht_ctid, Relation
 	itup = index_formtuple(RelationGetDescr(r), datum, nulls);
 	itup->t_tid = *ht_ctid;
 
+	/*
+	 * Notes in ExecUtils:ExecOpenIndices()
+	 *
 	RelationSetLockForWrite(r);
+	 */
+
 	res = gistdoinsert(r, itup, &giststate);
 	for (i = 0; i < r->rd_att->natts; i++)
 		if (compvec[i] == TRUE)
 			pfree((char *) datum[i]);
 	pfree(itup);
 	pfree(compvec);
 
-	/* XXX two-phase locking -- don't unlock the relation until EOT */
 	return res;
 }
 
@@ -1103,8 +1105,12 @@ gistdelete(Relation r, ItemPointer tid)
 	Buffer		buf;
 	Page		page;
 
-	/* must write-lock on delete */
+	/*
+	 * Notes in ExecUtils:ExecOpenIndices()
+	 * Also note that only vacuum deletes index tuples now...
+	 *
 	RelationSetLockForWrite(r);
+	 */
 
 	blkno = ItemPointerGetBlockNumber(tid);
 	offnum = ItemPointerGetOffsetNumber(tid);
@@ -1120,7 +1126,6 @@ gistdelete(Relation r, ItemPointer tid)
 
 	WriteBuffer(buf);
 
-	/* XXX -- two-phase locking, don't release the write lock */
 }
 
 void

src/backend/access/gist/gistscan.c

@@ -65,7 +65,12 @@ gistbeginscan(Relation r,
 {
 	IndexScanDesc s;
 
+	/*
+	 * Let index_beginscan does its work...
+	 *
 	RelationSetLockForRead(r);
+	 */
+
 	s = RelationGetIndexScan(r, fromEnd, nkeys, key);
 	gistregscan(s);
 

src/backend/access/hash/hashpage.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/access/hash/hashpage.c,v 1.17 1998/09/01 03:20:58 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/access/hash/hashpage.c,v 1.18 1998/12/15 12:45:10 vadim Exp $
  *
  * NOTES
  *	  Postgres hash pages look like ordinary relation pages.  The opaque
@@ -81,7 +81,7 @@ _hash_metapinit(Relation rel)
 
 	/* can't be sharing this with anyone, now... */
 	if (USELOCKING)
-		RelationSetLockForWrite(rel);
+		LockRelation(rel, AccessExclusiveLock);
 
 	if ((nblocks = RelationGetNumberOfBlocks(rel)) != 0)
 	{
@@ -169,7 +169,7 @@ _hash_metapinit(Relation rel)
 	_hash_relbuf(rel, metabuf, HASH_WRITE);
 
 	if (USELOCKING)
-		RelationUnsetLockForWrite(rel);
+		UnlockRelation(rel, AccessExclusiveLock);
 }
 
 /*
@@ -316,19 +316,16 @@ _hash_setpagelock(Relation rel,
 				  BlockNumber blkno,
 				  int access)
 {
-	ItemPointerData iptr;
 
 	if (USELOCKING)
 	{
-		ItemPointerSet(&iptr, blkno, 1);
-
 		switch (access)
 		{
 			case HASH_WRITE:
-				RelationSetSingleWLockPage(rel, &iptr);
+				LockPage(rel, blkno, ExclusiveLock);
 				break;
 			case HASH_READ:
-				RelationSetSingleRLockPage(rel, &iptr);
+				LockPage(rel, blkno, ShareLock);
 				break;
 			default:
 				elog(ERROR, "_hash_setpagelock: invalid access (%d) on blk %x: %s",
@@ -343,19 +340,16 @@ _hash_unsetpagelock(Relation rel,
 					BlockNumber blkno,
 					int access)
 {
-	ItemPointerData iptr;
 
 	if (USELOCKING)
 	{
-		ItemPointerSet(&iptr, blkno, 1);
-
 		switch (access)
 		{
 			case HASH_WRITE:
-				RelationUnsetSingleWLockPage(rel, &iptr);
+				UnlockPage(rel, blkno, ExclusiveLock);
 				break;
 			case HASH_READ:
-				RelationUnsetSingleRLockPage(rel, &iptr);
+				UnlockPage(rel, blkno, ShareLock);
 				break;
 			default:
 				elog(ERROR, "_hash_unsetpagelock: invalid access (%d) on blk %x: %s",