From 8bfa40d85802909990948c2d4c03350c40ba326b Mon Sep 17 00:00:00 2001
From: Michael Davidsaver <mdavidsaver@bnl.gov>
Date: Thu, 16 Jul 2015 17:05:41 -0400
Subject: [PATCH] dbScan: avoid race on shutdown

---
 src/ioc/db/dbScan.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/src/ioc/db/dbScan.c b/src/ioc/db/dbScan.c
index 9c1a1bef9..0e2d09326 100644
--- a/src/ioc/db/dbScan.c
+++ b/src/ioc/db/dbScan.c
@@ -178,10 +178,6 @@ void scanCleanup(void)
 
     epicsRingPointerDelete(onceQ);
 
-    epicsEventDestroy(startStopEvent);
-    epicsEventDestroy(onceSem);
-    onceSem = startStopEvent = NULL;
-
     free(periodicTaskId);
     papPeriodic = NULL;
     periodicTaskId = NULL;
@@ -191,7 +187,8 @@ long scanInit(void)
 {
     int i;
 
-    startStopEvent = epicsEventMustCreate(epicsEventEmpty);
+    if(!startStopEvent)
+        startStopEvent = epicsEventMustCreate(epicsEventEmpty);
     scanCtl = ctlPause;
 
     initPeriodic();
@@ -643,7 +640,8 @@ static void initOnce(void)
     if ((onceQ = epicsRingPointerCreate(onceQueueSize)) == NULL) {
         cantProceed("initOnce: Ring buffer create failed\n");
     }
-    onceSem = epicsEventMustCreate(epicsEventEmpty);
+    if(!onceSem)
+        onceSem = epicsEventMustCreate(epicsEventEmpty);
     onceTaskId = epicsThreadCreate("scanOnce",
         epicsThreadPriorityScanLow + nPeriodic,
         epicsThreadGetStackSize(epicsThreadStackBig), onceTask, 0);