mirrors/postgres
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Removed bad Assert(!buf->ri_lock) when unlocking exclusively

Browse Source 
locked buffer.
This commit is contained in:
Vadim B. Mikheev 1999-06-11 09:00:02 +00:00
parent 4ca7b4d2e5
commit 3b79cc0c55
1 changed files with 19 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

25
src/backend/storage/buffer/bufmgr.c
View File

@ -7,7 +7,7 @@
* *
* *
* IDENTIFICATION * IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/storage/buffer/bufmgr.c,v 1.54 1999/06/10 14:17:09 vadim Exp $ * $Header: /cvsroot/pgsql/src/backend/storage/buffer/bufmgr.c,v 1.55 1999/06/11 09:00:02 vadim Exp $
* *
*------------------------------------------------------------------------- *-------------------------------------------------------------------------
*/ */
@ -1960,7 +1960,12 @@ UnlockBuffers()
} }
if (BufferLocks[i] & BL_RI_LOCK) if (BufferLocks[i] & BL_RI_LOCK)
{ {
Assert(buf->ri_lock); /*
* Someone else could remove our RI lock when acquiring
* W lock. This is possible if we came here from elog(ERROR)
* from IpcSemaphore{Lock|Unlock}(WaitCLSemId). And so we
* don't do Assert(buf->ri_lock) here.
*/
buf->ri_lock = false; buf->ri_lock = false;
} }
if (BufferLocks[i] & BL_W_LOCK) if (BufferLocks[i] & BL_W_LOCK)
@ -2008,7 +2013,6 @@ LockBuffer(Buffer buffer, int mode)
{ {
Assert(buf->w_lock); Assert(buf->w_lock);
Assert(buf->r_locks == 0); Assert(buf->r_locks == 0);
Assert(!buf->ri_lock);
Assert(!(BufferLocks[buffer - 1] & (BL_R_LOCK | BL_RI_LOCK))) Assert(!(BufferLocks[buffer - 1] & (BL_R_LOCK | BL_RI_LOCK)))
buf->w_lock = false; buf->w_lock = false;
BufferLocks[buffer - 1] &= ~BL_W_LOCK; BufferLocks[buffer - 1] &= ~BL_W_LOCK;
@ -2043,10 +2047,15 @@ LockBuffer(Buffer buffer, int mode)
Assert(!(BufferLocks[buffer - 1] & (BL_R_LOCK | BL_W_LOCK | BL_RI_LOCK))); Assert(!(BufferLocks[buffer - 1] & (BL_R_LOCK | BL_W_LOCK | BL_RI_LOCK)));
while (buf->r_locks > 0 || buf->w_lock) while (buf->r_locks > 0 || buf->w_lock)
{ {
if (buf->r_locks > 3) if (buf->r_locks > 3 || (BufferLocks[buffer - 1] & BL_RI_LOCK))
{ {
if (!(BufferLocks[buffer - 1] & BL_RI_LOCK)) /*
BufferLocks[buffer - 1] |= BL_RI_LOCK; * Our RI lock might be removed by concurrent W lock
* acquiring (see what we do with RI locks below
* when our own W acquiring succeeded) and so
* we set RI lock again if we already did this.
*/
BufferLocks[buffer - 1] |= BL_RI_LOCK;
buf->ri_lock = true; buf->ri_lock = true;
} }
#ifdef HAS_TEST_AND_SET #ifdef HAS_TEST_AND_SET
@ -2063,6 +2072,10 @@ LockBuffer(Buffer buffer, int mode)
BufferLocks[buffer - 1] |= BL_W_LOCK; BufferLocks[buffer - 1] |= BL_W_LOCK;
if (BufferLocks[buffer - 1] & BL_RI_LOCK) if (BufferLocks[buffer - 1] & BL_RI_LOCK)
{ {
/*
* It's possible to remove RI locks acquired by another
* W lockers here, but they'll take care about it.
*/
buf->ri_lock = false; buf->ri_lock = false;
BufferLocks[buffer - 1] &= ~BL_RI_LOCK; BufferLocks[buffer - 1] &= ~BL_RI_LOCK;
} }