Rewrite timeout stop with channel

stress/client/main.go

@@ -179,26 +179,28 @@ func startServer(server *server, port int) {
 type stressClient struct {
 	testID        int
 	address       string
-	testDurationSecs int
 	selector      *weightedRandomTestSelector
 	interopClient testpb.TestServiceClient
+	stop          <-chan bool
 }
 
 // newStressClient construct a new stressClient.
-func newStressClient(id int, addr string, conn *grpc.ClientConn, selector *weightedRandomTestSelector, testDurSecs int) *stressClient {
+func newStressClient(id int, addr string, conn *grpc.ClientConn, selector *weightedRandomTestSelector, stop <-chan bool) *stressClient {
 	client := testpb.NewTestServiceClient(conn)
-	return &stressClient{testID: id, address: addr, selector: selector, testDurationSecs: testDurSecs, interopClient: client}
+	return &stressClient{testID: id, address: addr, selector: selector, interopClient: client, stop: stop}
 }
 
 // mainLoop uses weightedRandomTestSelector to select test case and runs the tests.
 func (c *stressClient) mainLoop(gauge *gauge) {
 	var numCalls int64
 	timeStarted := time.Now()
-	for testEndTime := time.Now().Add(time.Duration(c.testDurationSecs) * time.Second); c.testDurationSecs < 0 || time.Now().Before(testEndTime); {
+	for {
+		done := make(chan bool)
+		go func() {
 			test, err := c.selector.getNextTest()
 			if err != nil {
 				grpclog.Printf("%v", err)
-			continue
+				done <- false
 			}
 			switch test {
 			case "empty_unary":
@@ -214,9 +216,18 @@ func (c *stressClient) mainLoop(gauge *gauge) {
 			default:
 				grpclog.Fatalf("Unsupported test case: %d", test)
 			}
+			done <- true
+		}()
+		select {
+		case <-c.stop:
+			return
+		case r := <-done:
+			if r {
 				numCalls++
 				gauge.set(int64(float64(numCalls) / time.Since(timeStarted).Seconds()))
 			}
+		}
+	}
 }
 
 func logParameterInfo(addresses []string, tests []testCaseWithWeight) {
@@ -250,6 +261,8 @@ func main() {
 
 	var wg sync.WaitGroup
 	wg.Add(len(addresses) * *numChannelsPerServer * *numStubsPerChannel)
+	stop := make(chan bool)
+
 	var clientIndex int
 	for serverIndex, address := range addresses {
 		for connIndex := 0; connIndex < *numChannelsPerServer; connIndex++ {
@@ -260,7 +273,7 @@ func main() {
 			defer conn.Close()
 			for stubIndex := 0; stubIndex < *numStubsPerChannel; stubIndex++ {
 				clientIndex++
-				client := newStressClient(clientIndex, address, conn, testSelector, *testDurationSecs)
+				client := newStressClient(clientIndex, address, conn, testSelector, stop)
 				buf := fmt.Sprintf("/stress_test/server_%d/channel_%d/stub_%d/qps", serverIndex+1, connIndex+1, stubIndex+1)
 				go func() {
 					defer wg.Done()
@@ -275,6 +288,10 @@ func main() {
 		}
 	}
 	go startServer(metricsServer, *metricsPort)
+	if *testDurationSecs > 0 {
+		time.Sleep(time.Duration(*testDurationSecs) * time.Second)
+		close(stop)
+	}
 	wg.Wait()
 	grpclog.Printf(" ===== ALL DONE ===== ")