77 *
88 *
99 * IDENTIFICATION
10- * $Header: /cvsroot/pgsql/src/backend/storage/lmgr/proc.c,v 1.46 1998/12/2918:36:29 momjian Exp $
10+ * $Header: /cvsroot/pgsql/src/backend/storage/lmgr/proc.c,v 1.47 1998/12/2919:32:08 momjian Exp $
1111 *
1212 *-------------------------------------------------------------------------
1313 */
4646 *This is so that we can support more backends. (system-wide semaphore
4747 *sets run out pretty fast.) -ay 4/95
4848 *
49- * $Header: /cvsroot/pgsql/src/backend/storage/lmgr/proc.c,v 1.46 1998/12/2918:36:29 momjian Exp $
49+ * $Header: /cvsroot/pgsql/src/backend/storage/lmgr/proc.c,v 1.47 1998/12/2919:32:08 momjian Exp $
5050 */
5151#include <sys/time.h>
5252#include <unistd.h>
7777#include "storage/proc.h"
7878#include "utils/trace.h"
7979
80- static void HandleDeadLock (void );
80+ static void HandleDeadLock (int sig );
8181static PROC * ProcWakeup (PROC * proc ,int errType );
8282
8383#define DeadlockCheckTimer pg_options[OPT_DEADLOCKTIMEOUT]
@@ -154,6 +154,8 @@ InitProcess(IPCKey key)
154154 * Routine called if deadlock timer goes off. See ProcSleep()
155155 * ------------------
156156 */
157+ pqsignal (SIGALRM ,HandleDeadLock );
158+
157159SpinAcquire (ProcStructLock );
158160
159161/* attach to the free list */
@@ -447,8 +449,10 @@ ProcSleep(PROC_QUEUE *waitQueue,/* lock->waitProcs */
447449TransactionId xid )/* needed by user locks, see below */
448450{
449451int i ;
450- bool deadlock_checked = false;
451452PROC * proc ;
453+ bool deadlock_checked = false;
454+ struct itimerval timeval ,
455+ dummy ;
452456
453457/*
454458 * If the first entries in the waitQueue have a greater priority than
@@ -512,28 +516,27 @@ ProcSleep(PROC_QUEUE *waitQueue,/* lock->waitProcs */
512516SpinRelease (spinlock );
513517
514518/* --------------
515- * We set this so we can wake upafter one second to check for a deadlock.
519+ * We set this so we can wake upperiodically and check for a deadlock.
516520 * If a deadlock is detected, the handler releases the processes
517521 * semaphore and aborts the current transaction.
522+ *
523+ * Need to zero out struct to set the interval and the micro seconds fields
524+ * to 0.
518525 * --------------
519526 */
527+ MemSet (& timeval ,0 ,sizeof (struct itimerval ));
528+ timeval .it_value .tv_sec = \
529+ (DeadlockCheckTimer ?DeadlockCheckTimer :DEADLOCK_CHECK_TIMER );
520530
521531do
522532{
523533MyProc -> errType = NO_ERROR ;/* reset flag after deadlock check */
524534
525- if (deadlock_checked == false)
526- {
527- if (sleep (DeadlockCheckTimer ?DeadlockCheckTimer :DEADLOCK_CHECK_TIMER )
528- == 0 /* no signal interruption */ )
529- {
530- HandleDeadLock ();
531- deadlock_checked = true;
532- }
533- }
534- else
535- pause ();
536-
535+ if (!deadlock_checked )
536+ if (setitimer (ITIMER_REAL ,& timeval ,& dummy ))
537+ elog (FATAL ,"ProcSleep: Unable to set timer for process wakeup" );
538+ deadlock_checked = true;
539+
537540/* --------------
538541 * if someone wakes us between SpinRelease and IpcSemaphoreLock,
539542 * IpcSemaphoreLock will not block. The wakeup is "saved" by
@@ -545,6 +548,14 @@ ProcSleep(PROC_QUEUE *waitQueue,/* lock->waitProcs */
545548}while (MyProc -> errType == STATUS_NOT_FOUND );/* sleep after deadlock
546549 * check */
547550
551+ /* ---------------
552+ * We were awoken before a timeout - now disable the timer
553+ * ---------------
554+ */
555+ timeval .it_value .tv_sec = 0 ;
556+ if (setitimer (ITIMER_REAL ,& timeval ,& dummy ))
557+ elog (FATAL ,"ProcSleep: Unable to diable timer for process wakeup" );
558+
548559/* ----------------
549560 * We were assumed to be in a critical section when we went
550561 * to sleep.
@@ -687,7 +698,7 @@ ProcAddLock(SHM_QUEUE *elem)
687698 * --------------------
688699 */
689700static void
690- HandleDeadLock ()
701+ HandleDeadLock (int sig )
691702{
692703LOCK * mywaitlock ;
693704