opensourcemirror
/
postgresql
mirror of git://git.postgresql.org/git/postgresql.git
1
0
Fork 0
Code Issues Releases Wiki Activity

Fix a variety of locking problems like newer lock waiters getting 

lock before older waiters, and having readlock people not share
locks if a writer is waiting for a lock, and waiting writers not
getting priority over waiting readers.
This commit is contained in:
Bruce Momjian 1998-01-23 22:16:48 +00:00
parent 1de8926bbe
commit 0e8ac82c63
2 changed files with 18 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
src/backend/storage/lmgr/lock.c
View File

@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/storage/lmgr/lock.c,v 1.19 1998/01/23 06:01:03 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/storage/lmgr/lock.c,v 1.20 1998/01/23 22:16:46 momjian Exp $
*
* NOTES
* Outside modules can create a lock table and acquire/release
@ -708,6 +708,20 @@ LockResolveConflicts(LOCKTAB *ltable,
result->nHolding = 0;
}
{
/* ------------------------
* If someone with a greater priority is waiting for the lock,
* do not continue and share the lock, even if we can. bjm
* ------------------------
*/
int myprio = ltable->ctl->prio[lockt];
PROC_QUEUE *waitQueue = &(lock->waitProcs);
PROC *topproc = (PROC *) MAKE_PTR(waitQueue->links.prev);
if (waitQueue->size && topproc->prio > myprio)
return STATUS_FOUND;
}
/* ----------------------------
* first check for global conflicts: If no locks conflict
* with mine, then I get the lock.

6
src/backend/storage/lmgr/proc.c
View File

@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/storage/lmgr/proc.c,v 1.26 1998/01/23 06:01:05 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/storage/lmgr/proc.c,v 1.27 1998/01/23 22:16:48 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@ -46,7 +46,7 @@
* This is so that we can support more backends. (system-wide semaphore
* sets run out pretty fast.) -ay 4/95
*
* $Header: /cvsroot/pgsql/src/backend/storage/lmgr/proc.c,v 1.26 1998/01/23 06:01:05 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/storage/lmgr/proc.c,v 1.27 1998/01/23 22:16:48 momjian Exp $
*/
#include <sys/time.h>
#include <unistd.h>
@ -469,7 +469,7 @@ ProcSleep(PROC_QUEUE *queue,
proc = (PROC *) MAKE_PTR(queue->links.prev);
for (i = 0; i < queue->size; i++)
{
if (proc->prio < prio)
if (proc->prio >= prio)
proc = (PROC *) MAKE_PTR(proc->links.prev);
else
break;