add pause job execution on the scheduler (#518)

* add pause job execution on the scheduler

* Update scheduler_test.go

* fix formatting

example_test.go

@@ -623,6 +623,16 @@ func ExampleScheduler_NextRun() {
 	// 10:30
 }
 
+func ExampleScheduler_PauseJobExecution() {
+	s := gocron.NewScheduler(time.UTC)
+	_, _ = s.Every("1s").Do(task)
+	s.StartAsync()
+	s.PauseJobExecution(true)
+	// jobs don't run
+	s.PauseJobExecution(false)
+	// jobs run again
+}
+
 func ExampleScheduler_RegisterEventListeners() {
 	s := gocron.NewScheduler(time.UTC)
 

executor.go

@@ -37,12 +37,13 @@ const (
 )
 
 type executor struct {
-	jobFunctions chan jobFunction   // the chan upon which the jobFunctions are passed in from the scheduler
-	ctx          context.Context    // used to tell the executor to stop
-	cancel       context.CancelFunc // used to tell the executor to stop
-	wg           *sync.WaitGroup    // used by the scheduler to wait for the executor to stop
-	jobsWg       *sync.WaitGroup    // used by the executor to wait for all jobs to finish
-	singletonWgs *sync.Map          // used by the executor to wait for the singleton runners to complete
+	jobFunctions  chan jobFunction   // the chan upon which the jobFunctions are passed in from the scheduler
+	ctx           context.Context    // used to tell the executor to stop
+	cancel        context.CancelFunc // used to tell the executor to stop
+	wg            *sync.WaitGroup    // used by the scheduler to wait for the executor to stop
+	jobsWg        *sync.WaitGroup    // used by the executor to wait for all jobs to finish
+	singletonWgs  *sync.Map          // used by the executor to wait for the singleton runners to complete
+	skipExecution *atomic.Bool       // used to pause the execution of jobs
 
 	limitMode               limitMode        // when SetMaxConcurrentJobs() is set upon the scheduler
 	limitModeMaxRunningJobs int              // stores the maximum number of concurrently running jobs
@@ -134,6 +135,7 @@ func (e *executor) start() {
 	e.jobsWg = &sync.WaitGroup{}
 
 	e.stopped = atomic.NewBool(false)
+	e.skipExecution = atomic.NewBool(false)
 
 	e.limitModeQueueMu.Lock()
 	e.limitModeQueue = make(chan jobFunction, 1000)
@@ -187,7 +189,7 @@ func (e *executor) run() {
 	for {
 		select {
 		case f := <-e.jobFunctions:
-			if e.stopped.Load() {
+			if e.stopped.Load() || e.skipExecution.Load() {
 				continue
 			}
 

scheduler.go

@@ -1441,3 +1441,7 @@ func (s *Scheduler) RegisterEventListeners(eventListeners ...EventListener) {
 		job.RegisterEventListeners(eventListeners...)
 	}
 }
+
+func (s *Scheduler) PauseJobExecution(shouldPause bool) {
+	s.executor.skipExecution.Store(shouldPause)
+}

scheduler_test.go

@@ -2707,3 +2707,31 @@ func TestScheduler_WithDistributedLocker_With_Name(t *testing.T) {
 		})
 	}
 }
+
+func TestScheduler_PauseJobExecution(t *testing.T) {
+	s := NewScheduler(time.UTC)
+	var counter int
+	var mu sync.Mutex
+
+	_, err := s.Every("100ms").Do(func() {
+		mu.Lock()
+		counter++
+		mu.Unlock()
+	})
+	require.NoError(t, err)
+
+	s.StartAsync()
+	time.Sleep(50 * time.Millisecond)
+
+	s.PauseJobExecution(true)
+	time.Sleep(200 * time.Millisecond)
+
+	s.PauseJobExecution(false)
+	time.Sleep(100 * time.Millisecond)
+	s.Stop()
+
+	mu.Lock()
+	defer mu.Unlock()
+	assert.GreaterOrEqual(t, counter, 1)
+	assert.LessOrEqual(t, counter, 2)
+}