Fix #837

Author: apocelipes

executor.go

@@ -36,6 +36,8 @@ type executor struct {
 
 	// used by the executor to receive a stop signal from the scheduler
 	stopCh chan struct{}
+	// ensure that stop runs before the next call to start and only runs once
+	stopOnce *sync.Once
 	// the timeout value when stopping
 	stopTimeout time.Duration
 	// used to signal that the executor has completed shutdown
@@ -88,6 +90,7 @@ func (e *executor) start() {
 	// any other uses within the executor should create a context
 	// using the executor context as parent.
 	e.ctx, e.cancel = context.WithCancel(context.Background())
+	e.stopOnce = &sync.Once{}
 
 	// the standardJobsWg tracks
 	standardJobsWg := &waitGroupWithMutex{}
@@ -111,7 +114,9 @@ func (e *executor) start() {
 		case jIn := <-e.jobsIn:
 			select {
 			case <-e.stopCh:
-				e.stop(standardJobsWg, singletonJobsWg, limitModeJobsWg)
+				e.stopOnce.Do(func() {
+					e.stop(standardJobsWg, singletonJobsWg, limitModeJobsWg)
+				})
 				return
 			default:
 			}
@@ -131,7 +136,7 @@ func (e *executor) start() {
 
 			// spin off into a goroutine to unblock the executor and
 			// allow for processing for more work
-			go func() {
+			go func(executorCtx context.Context) {
 				// make sure to cancel the above context per the docs
 				// // Canceling this context releases resources associated with it, so code should
 				// // call cancel as soon as the operations running in this Context complete.
@@ -211,8 +216,7 @@ func (e *executor) start() {
 						}
 					} else {
 						select {
-						case <-e.stopCh:
-							e.stop(standardJobsWg, singletonJobsWg, limitModeJobsWg)
+						case <-executorCtx.Done():
 							return
 						default:
 						}
@@ -228,9 +232,11 @@ func (e *executor) start() {
 						}(*j)
 					}
 				}
-			}()
+			}(e.ctx)
 		case <-e.stopCh:
-			e.stop(standardJobsWg, singletonJobsWg, limitModeJobsWg)
+			e.stopOnce.Do(func() {
+				e.stop(standardJobsWg, singletonJobsWg, limitModeJobsWg)
+			})
 			return
 		}
 	}