[Merge] lp:~ralph-lange/epics-base/cac-dtor-racecond-fix into lp:epics-base

[Ralph Lange <Ralph.Lange@bessy.de>]

Ralph Lange has proposed merging lp:~ralph-lange/epics-base/cac-dtor-racecond-fix into lp:epics-base.

Requested reviews:
  EPICS Core Developers (epics-core)


While the cac dtor runs and waits for TCP circuit threads to exit,
new circuits could be opened by name resolution replies on existing
(still active) circuits.

Avoid this by setting a flag (lock being held) in the dtor, and
checking it in cac::transferChanToVirtCircuit.

-- 
https://code.launchpad.net/~ralph-lange/epics-base/cac-dtor-racecond-fix/+merge/33449
Your team EPICS Core Developers is requested to review the proposed merge of lp:~ralph-lange/epics-base/cac-dtor-racecond-fix into lp:epics-base.

=== modified file 'src/ca/cac.cpp'
--- src/ca/cac.cpp	2010-08-16 23:45:06 +0000
+++ src/ca/cac.cpp	2010-08-23 20:26:17 +0000
@@ -146,7 +146,8 @@
     maxRecvBytesTCP ( MAX_TCP ),
     maxContigFrames ( contiguousMsgCountWhichTriggersFlowControl ),
     beaconAnomalyCount ( 0u ),
-    iiuExistenceCount ( 0u )
+    iiuExistenceCount ( 0u ),
+    cacShutdownInProgress ( false )
 {
 	if ( ! osiSockAttach () ) {
         throwWithLocation ( caErrorCode (ECA_INTERNAL) );
@@ -282,7 +283,10 @@
         epicsGuard < epicsMutex > guard ( this->mutex );
         if ( this->pudpiiu ) {
             this->pudpiiu->shutdown ( cbGuard, guard );
-    
+
+            // make sure no new tcp circuits are created
+            this->cacShutdownInProgress = true;
+
             //
             // shutdown all tcp circuits
             //
@@ -576,6 +580,13 @@
     epicsGuard < epicsMutex > guard ( this->mutex );
 
     /*
+     * Do not open new circuits while the cac is shutting down
+     */
+    if ( this->cacShutdownInProgress ) {
+        return;
+    }
+
+    /*
      * ignore search replies for deleted channels
      */
     nciu * pChan = this->chanTable.lookup ( cid );

=== modified file 'src/ca/cac.h'
--- src/ca/cac.h	2010-08-10 21:05:46 +0000
+++ src/ca/cac.h	2010-08-23 20:26:17 +0000
@@ -283,6 +283,7 @@
     unsigned beaconAnomalyCount;
     unsigned short _serverPort;
     unsigned iiuExistenceCount;
+    bool cacShutdownInProgress;
 
     void recycleReadNotifyIO ( 
         epicsGuard < epicsMutex > &, netReadNotifyIO &io );