Fix #835 and #837 (#836)

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{}
@@ -131,7 +134,7 @@ 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 +214,7 @@ func (e *executor) start() {
 						}
 					} else {
 						select {
-						case <-e.stopCh:
-							e.stop(standardJobsWg, singletonJobsWg, limitModeJobsWg)
+						case <-executorCtx.Done():
 							return
 						default:
 						}
@@ -228,7 +230,7 @@ func (e *executor) start() {
 						}(*j)
 					}
 				}
-			}()
+			}(e.ctx)
 		case <-e.stopCh:
 			e.stop(standardJobsWg, singletonJobsWg, limitModeJobsWg)
 			return
@@ -473,6 +475,7 @@ func (e *executor) incrementJobCounter(j internalJob, status JobStatus) {
 }
 
 func (e *executor) stop(standardJobsWg, singletonJobsWg, limitModeJobsWg *waitGroupWithMutex) {
+	e.stopOnce.Do(func() {
 		e.logger.Debug("gocron: stopping executor")
 		// we've been asked to stop. This is either because the scheduler has been told
 		// to stop all jobs or the scheduler has been asked to completely shutdown.
@@ -555,4 +558,5 @@ func (e *executor) stop(standardJobsWg, singletonJobsWg, limitModeJobsWg *waitGr
 		if e.limitMode != nil {
 			e.limitMode.started = false
 		}
+	})
 }

scheduler.go

@@ -141,7 +141,7 @@ func NewScheduler(options ...SchedulerOption) (Scheduler, error) {
 		jobUpdateNextRuns:      make(chan uuid.UUID),
 		jobsOutCompleted:       make(chan uuid.UUID),
 		jobOutRequest:          make(chan jobOutRequest, 1000),
-		done:                   make(chan error),
+		done:                   make(chan error, 1),
 	}
 
 	s := &scheduler{