Protect job.RunCount() with mutex (#375)

* Protect job.RunCount() with mutex

* Minor refactor usage in job.RunCount()

* Lower sleeptime in TestScheduler_WaitForSchedules

job.go

@@ -434,6 +434,8 @@ func (j *Job) setNextRun(t time.Time) {
 
 // RunCount returns the number of time the job ran so far
 func (j *Job) RunCount() int {
+	j.mu.Lock()
+	defer j.mu.Unlock()
 	return j.runCount
 }
 

scheduler.go

@@ -323,14 +323,14 @@ func (s *Scheduler) calculateWeeks(job *Job, lastRun time.Time) nextRun {
 }
 
 func (s *Scheduler) calculateTotalDaysDifference(lastRun time.Time, daysToWeekday int, job *Job) int {
-	if job.getInterval() > 1 && job.RunCount() < len(job.Weekdays()) { // just count weeks after the first jobs were done
-		return daysToWeekday
-	}
-	if job.getInterval() > 1 && job.RunCount() >= len(job.Weekdays()) {
+	if job.getInterval() > 1 {
+		// just count weeks after the first jobs were done
+		if job.RunCount() < len(job.Weekdays()) {
+			return daysToWeekday
+		}
 		if daysToWeekday > 0 {
 			return int(job.getInterval())*7 - (allWeekDays - daysToWeekday)
 		}
-
 		return int(job.getInterval()) * 7
 	}
 

scheduler_test.go

@@ -1841,7 +1841,7 @@ func TestScheduler_WaitForSchedules(t *testing.T) {
 	require.NoError(t, err)
 	s.StartAsync()
 
-	time.Sleep(1100 * time.Millisecond)
+	time.Sleep(1050 * time.Millisecond)
 	s.Stop()
 
 	counterMutex.RLock()