database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-07-08 11:42:09 +03:00
Code Activity

Ensure that 'errno' is saved and restored by all signal handlers that

Browse Source 
might change it.  Experimentation shows that the signal handler call
mechanism does not save/restore errno for you, at least not on Linux
or HPUX, so this is definitely a real risk.
This commit is contained in:
Tom Lane
2000-12-18 17:33:42 +00:00
parent c431db9714
commit 5491233f52
6 changed files with 79 additions and 16 deletions
Download Patch File Download Diff File Expand all files Collapse all files

14
src/backend/storage/lmgr/proc.c
View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/storage/lmgr/proc.c,v 1.87 2000/12/18 00:44:47 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/storage/lmgr/proc.c,v 1.88 2000/12/18 17:33:41 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -48,10 +48,11 @@
* 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 1.87 2000/12/18 00:44:47 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/storage/lmgr/proc.c,v 1.88 2000/12/18 17:33:41 tgl Exp $
*/
#include "postgres.h"
#include <errno.h>
#include <sys/time.h>
#include <unistd.h>
#include <signal.h>
@ -298,7 +299,7 @@ InitProcess(void)
}
/* -----------------------
* get off the wait queue
* get process off any wait queue it might be on
* -----------------------
*/
static bool
@ -623,10 +624,11 @@ ins:;
waitQueue->size++;
lock->waitMask |= myMask;
SpinRelease(spinlock);
MyProc->errType = NO_ERROR; /* initialize result for success */
SpinRelease(spinlock);
/* --------------
* Set timer so we can wake up after awhile and check for a deadlock.
* If a deadlock is detected, the handler releases the process's
@ -826,6 +828,7 @@ ProcAddLock(SHM_QUEUE *elem)
void
HandleDeadLock(SIGNAL_ARGS)
{
int save_errno = errno;
LOCK *mywaitlock;
LockLockTable();
@ -846,6 +849,7 @@ HandleDeadLock(SIGNAL_ARGS)
MyProc->links.next == INVALID_OFFSET)
{
UnlockLockTable();
errno = save_errno;
return;
}
@ -858,6 +862,7 @@ HandleDeadLock(SIGNAL_ARGS)
{
/* No deadlock, so keep waiting */
UnlockLockTable();
errno = save_errno;
return;
}
@ -891,6 +896,7 @@ HandleDeadLock(SIGNAL_ARGS)
* conditions. i don't claim to understand this...
*/
UnlockLockTable();
errno = save_errno;
}
void