Only allow close to happen once

License: MIT
Signed-off-by: Michael Avila <davidmichaelavila@gmail.com>

provider/queue.go

@@ -47,17 +47,21 @@ func NewQueue(ctx context.Context, name string, ds datastore.Datastore) (*Queue,
 		dequeue: make(chan cid.Cid),
 		enqueue: make(chan cid.Cid),
 		close:   make(chan struct{}),
-		done:    make(chan struct{}),
+		done:    make(chan struct{}, 1),
 	}
 	q.work()
 	return q, nil
 }
 
 // Close stops the queue
 func (q *Queue) Close() error {
-	q.close <- struct{}{}
-	<-q.done
-	return nil
+	for {
+		select {
+		case q.close <- struct{}{}:
+		case <-q.done:
+			return nil
+		}
+	}
 }
 
 // Enqueue puts a cid in the queue
@@ -113,6 +117,10 @@ func (q *Queue) work() {
 		var k datastore.Key = datastore.Key{}
 		var c cid.Cid = cid.Undef
 
+		defer func() {
+			q.done <- struct{}{}
+		}()
+
 		for {
 			if c == cid.Undef {
 				k, c = q.nextEntry()
@@ -144,10 +152,8 @@ func (q *Queue) work() {
 				c = cid.Undef
 				q.head++
 			case <-q.ctx.Done():
-				q.done <- struct{}{}
 				return
 			case <-q.close:
-				q.done <- struct{}{}
 				return
 			}
 		}