htlcswitch: expand TestWaitingQueueThreadSafety to assert proper queue length

htlcswitch/queue.go

@@ -67,8 +67,6 @@ func (p *packetQueue) Stop() {
 	close(p.quit)
 
 	p.queueCond.Signal()
-
-	p.wg.Wait()
 }
 
 // packetCoordinator is a goroutine that handles the packet overflow queue.
@@ -126,8 +124,8 @@ func (p *packetQueue) packetCoordinator() {
 				p.queueCond.L.Lock()
 				p.queue[0] = nil
 				p.queue = p.queue[1:]
-				p.queueCond.L.Unlock()
 				atomic.AddInt32(&p.queueLen, -1)
+				p.queueCond.L.Unlock()
 			case <-p.quit:
 				return
 			}

htlcswitch/queue_test.go

@@ -29,6 +29,14 @@ func TestWaitingQueueThreadSafety(t *testing.T) {
 		})
 	}
 
+	// The reported length of the queue should be the exact number of
+	// packets we added above.
+	queueLength := q.Length()
+	if queueLength != numPkts {
+		t.Fatalf("queue has wrong length: expected %v, got %v", numPkts,
+			queueLength)
+	}
+
 	var b []lnwire.MilliSatoshi
 	for i := 0; i < numPkts; i++ {
 		q.SignalFreeSlot()
@@ -42,6 +50,14 @@ func TestWaitingQueueThreadSafety(t *testing.T) {
 		}
 	}
 
+	// The length of the queue should be zero at this point.
+	time.Sleep(time.Millisecond * 50)
+	queueLength = q.Length()
+	if queueLength != 0 {
+		t.Fatalf("queue has wrong length: expected %v, got %v", 0,
+			queueLength)
+	}
+
 	if !reflect.DeepEqual(b, a) {
 		t.Fatal("wrong order of the objects")
 	}