How to handle waitingForLock in LockWaitCancel()

Hi,

I sometimes encountered SEGV errors in my test case
when I canceled the execution.
Probably it's due to the almost simultaneous arrival
of multiple signals and the following patch seems to
fix the bug. However I'm afraid that the change should
cause another bug.

Comments ?

Regards,
Hiroshi Inoue

Index: proc.c
===================================================================
RCS file:
/home/projects/pgsql/cvsroot/pgsql/src/backend/storage/lmgr/proc.c,v
retrieving revision 1.98
diff -c -c -r1.98 proc.c
*** proc.c 2001/01/26 18:23:12 1.98
--- proc.c 2001/03/05 02:28:09
***************
*** 327,334 ****
if (!waitingForLock)
return false;

- waitingForLock = false;
-
/* Turn off the deadlock timer, if it's still running (see
ProcSleep) */
#ifndef __BEOS__
{
--- 327,332 ----
***************
*** 345,350 ****
--- 343,349 ----

/* Unlink myself from the wait queue, if on it (might not be
anymore!) *
/
LockLockTable();
+ waitingForLock = false;
if (MyProc->links.next != INVALID_OFFSET)
RemoveFromWaitQueue(MyProc);
UnlockLockTable();