diff --git a/src/ioc/db/dbEvent.c b/src/ioc/db/dbEvent.c index 5e386dd5c..fb1f3a168 100644 --- a/src/ioc/db/dbEvent.c +++ b/src/ioc/db/dbEvent.c @@ -117,6 +117,8 @@ static char *EVENT_PEND_NAME = "eventTask"; static struct evSubscrip canceledEvent; +static epicsMutexId stopSync; + static unsigned short ringSpace ( const struct event_que *pevq ) { if ( pevq->evque[pevq->putix] == EVENTQEMPTY ) { @@ -258,6 +260,10 @@ dbEventCtx db_init_events (void) { struct event_user * evUser; + if (!stopSync) { + stopSync = epicsMutexMustCreate(); + } + if (!dbevEventUserFreeList) { freeListInitPvt(&dbevEventUserFreeList, sizeof(struct event_user),8); @@ -321,6 +327,8 @@ fail: return NULL; } + + /* intentionally leak stopSync to avoid possible shutdown races */ /* * DB_CLOSE_EVENTS() * @@ -356,11 +364,15 @@ void db_close_events (dbEventCtx ctx) epicsMutexUnlock ( evUser->lock ); + epicsMutexMustLock (stopSync); + epicsEventDestroy(evUser->pexitsem); epicsEventDestroy(evUser->ppendsem); epicsEventDestroy(evUser->pflush_sem); epicsMutexDestroy(evUser->lock); + epicsMutexUnlock (stopSync); + freeListFree(dbevEventUserFreeList, evUser); } @@ -1043,8 +1055,15 @@ static void event_task (void *pParm) taskwdRemove(epicsThreadGetIdSelf()); + /* use stopSync to ensure pexitsem is not destroy'd + * until epicsEventSignal() has returned. + */ + epicsMutexMustLock (stopSync); + epicsEventSignal(evUser->pexitsem); + epicsMutexUnlock(stopSync); + return; }