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Initial MVCC code.

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New code for locking buffer' context.
This commit is contained in:
Vadim B. Mikheev
1998-12-15 12:47:01 +00:00
parent c5a27161a1
commit 3f7fbf85dc
65 changed files with 1391 additions and 1282 deletions
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27
src/backend/access/nbtree/nbtinsert.c
View File

@@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtinsert.c,v 1.31 1998/11/27 19:51:40 vadim Exp $
* $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtinsert.c,v 1.32 1998/12/15 12:45:20 vadim Exp $
*
*-------------------------------------------------------------------------
*/
@@ -18,6 +18,7 @@
#include <storage/bufpage.h>
#include <access/nbtree.h>
#include <access/heapam.h>
#include <access/xact.h>
#include <storage/bufmgr.h>
#include <fmgr.h>
@@ -67,6 +68,8 @@ _bt_doinsert(Relation rel, BTItem btitem, bool index_is_unique, Relation heapRel
/* trade in our read lock for a write lock */
_bt_relbuf(rel, buf, BT_READ);
l1:
buf = _bt_getbuf(rel, blkno, BT_WRITE);
/*
@@ -120,9 +123,25 @@ _bt_doinsert(Relation rel, BTItem btitem, bool index_is_unique, Relation heapRel
{ /* they're equal */
btitem = (BTItem) PageGetItem(page, PageGetItemId(page, offset));
htup.t_self = btitem->bti_itup.t_tid;
heap_fetch(heapRel, SnapshotSelf, &htup, &buffer);
if (htup.t_data != NULL)
{ /* it is a duplicate */
heap_fetch(heapRel, SnapshotDirty, &htup, &buffer);
if (htup.t_data != NULL) /* it is a duplicate */
{
TransactionId xwait =
(TransactionIdIsValid(SnapshotDirty->xmin)) ?
SnapshotDirty->xmin : SnapshotDirty->xmax;
/*
* If this tuple is being updated by other transaction
* then we have to wait for its commit/abort.
*/
if (TransactionIdIsValid(xwait))
{
if (nbuf != InvalidBuffer)
_bt_relbuf(rel, nbuf, BT_READ);
_bt_relbuf(rel, buf, BT_WRITE);
XactLockTableWait(xwait);
goto l1; /* continue from the begin */
}
elog(ERROR, "Cannot insert a duplicate key into a unique index");
}
/* htup null so no buffer to release */

20
src/backend/access/nbtree/nbtpage.c
View File

@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtpage.c,v 1.16 1998/09/01 03:21:14 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtpage.c,v 1.17 1998/12/15 12:45:23 vadim Exp $
*
* NOTES
* Postgres btree pages look like ordinary relation pages. The opaque
@@ -93,7 +93,7 @@ _bt_metapinit(Relation rel)
/* can't be sharing this with anyone, now... */
if (USELOCKING)
RelationSetLockForWrite(rel);
LockRelation(rel, AccessExclusiveLock);
if ((nblocks = RelationGetNumberOfBlocks(rel)) != 0)
{
@@ -120,7 +120,7 @@ _bt_metapinit(Relation rel)
/* all done */
if (USELOCKING)
RelationUnsetLockForWrite(rel);
UnlockRelation(rel, AccessExclusiveLock);
}
#ifdef NOT_USED
@@ -571,32 +571,26 @@ _bt_getstackbuf(Relation rel, BTStack stack, int access)
static void
_bt_setpagelock(Relation rel, BlockNumber blkno, int access)
{
ItemPointerData iptr;
if (USELOCKING)
{
ItemPointerSet(&iptr, blkno, P_HIKEY);
if (access == BT_WRITE)
RelationSetSingleWLockPage(rel, &iptr);
LockPage(rel, blkno, ExclusiveLock);
else
RelationSetSingleRLockPage(rel, &iptr);
LockPage(rel, blkno, ShareLock);
}
}
static void
_bt_unsetpagelock(Relation rel, BlockNumber blkno, int access)
{
ItemPointerData iptr;
if (USELOCKING)
{
ItemPointerSet(&iptr, blkno, P_HIKEY);
if (access == BT_WRITE)
RelationUnsetSingleWLockPage(rel, &iptr);
UnlockPage(rel, blkno, ExclusiveLock);
else
RelationUnsetSingleRLockPage(rel, &iptr);
UnlockPage(rel, blkno, ShareLock);
}
}