feat: give high priority to closeChan

worker.go

@@ -91,24 +91,34 @@ func (w *workerWrapper) run() {
 		// NOTE: Blocking here will prevent the worker from closing down.
 		w.worker.BlockUntilReady()
 		select {
-		case w.reqChan <- workRequest{
-			jobChan:       jobChan,
-			retChan:       retChan,
-			interruptFunc: w.interrupt,
-		}:
+		// give more priority to closeChan. Because select will randomly select one when multiple channel available,
+		// when many closeChan and reqChan come at the same time in extreme cases, giving high priority to closeChan
+		// to prevent closeChan to be ignored all the time
+		case <-w.closeChan:
+			return
+		default:
+			nextReq := workRequest{
+				jobChan:       jobChan,
+				retChan:       retChan,
+				interruptFunc: w.interrupt,
+			}
+
 			select {
-			case payload := <-jobChan:
-				result := w.worker.Process(payload)
+			case w.reqChan <- nextReq:
 				select {
-				case retChan <- result:
+				case payload := <-jobChan:
+					result := w.worker.Process(payload)
+					select {
+					case retChan <- result:
+					case <-w.interruptChan:
+						w.interruptChan = make(chan struct{})
+					}
 				case <-w.interruptChan:
 					w.interruptChan = make(chan struct{})
 				}
-			case <-w.interruptChan:
-				w.interruptChan = make(chan struct{})
+			case <-w.closeChan:
+				return
 			}
-		case <-w.closeChan:
-			return
 		}
 	}
 }