Add barrier

src/restic/worker/pool_test.go

@@ -96,8 +96,14 @@ type Job struct {
 	suc chan struct{}
 }
 
-func wait(job worker.Job, done <-chan struct{}) (interface{}, error) {
+func TestPoolCancel(t *testing.T) {
+	barrier := make(chan struct{})
+
+	wait := func(job worker.Job, done <-chan struct{}) (interface{}, error) {
 		j := job.Data.(Job)
+
+		<-barrier
+
 		select {
 		case j.suc <- struct{}{}:
 			return time.Now(), nil
@@ -106,14 +112,14 @@ func wait(job worker.Job, done <-chan struct{}) (interface{}, error) {
 		}
 	}
 
-func TestPoolCancel(t *testing.T) {
 	jobCh, resCh, p := newBufferedPool(20, concurrency, wait)
 
-	suc := make(chan struct{}, 1)
+	suc := make(chan struct{})
 	for i := 0; i < 20; i++ {
 		jobCh <- worker.Job{Data: Job{suc: suc}}
 	}
 
+	close(barrier)
 	<-suc
 	p.Cancel()
 	p.Wait()