clean up state transitions

src/libCom/timer/timer.cpp

@@ -148,7 +148,6 @@ void timer::privateCancel ( epicsGuard < epicsMutex > & locker )
     }
     else if ( this->curState == stateActive ) {
         this->queue.cancelPending = true;
-        this->curState = timer::stateLimbo;
         if ( this->queue.processThread != epicsThreadGetIdSelf() ) {
             // make certain timer expire() does not run after cancel () returns,
             // but dont require that lock is applied while calling expire()
@@ -158,15 +157,19 @@ void timer::privateCancel ( epicsGuard < epicsMutex > & locker )
                         this->queue.pExpireTmr == this ) {
                     this->queue.cancelBlockingEvent.wait ();
                 }
-                // in case other threads are waiting
-                this->queue.cancelBlockingEvent.signal ();
             }
+            // in case other threads are waiting
+            this->queue.cancelBlockingEvent.signal ();
         }
     }
 }
 
 epicsTimer::expireInfo timer::getExpireInfo () const
 {
+    // taking a lock here guarantees that users will not 
+    // see brief intervals when a timer isnt active because
+    // it is is canceled when start is called
+    epicsGuard < epicsMutex > locker ( this->queue.mutex );
     if ( this->curState == statePending || this->curState == stateActive ) {
         return expireInfo ( true, this->exp );
     }

src/libCom/timer/timerQueue.cpp

@@ -118,22 +118,25 @@ double timerQueue::process ( const epicsTime & currentTime )
         // while the call back was running
         //
         if ( this->cancelPending ) {
+            this->pExpireTmr->curState = timer::stateLimbo;
 
             // 1) if another thread is canceling cancel() waits for this
             // 2) if this thread is canceling in the timer callback then
             // dont touch timer or notify here because the cancel might 
-            // have occurred because they destroyed the time rin the 
+            // have occurred because they destroyed the timer in the 
             // callback
             this->cancelPending = false;
             this->cancelBlockingEvent.signal ();
         }
-        // restart as nec
         else {
-            this->pExpireTmr->curState = timer::stateLimbo;
+            // restart as nec
             if ( expStat.restart() ) {
                 this->pExpireTmr->privateStart ( 
                     *pTmpNotify, currentTime + expStat.expirationDelay() );
             }
+            else {
+                this->pExpireTmr->curState = timer::stateLimbo;
+            }
         }
         this->pExpireTmr = 0;