Golang runtime.After函數代碼示例

// TODO(jdef): find a way to test this without killing CI builds.
// intended to be run with -race
func TestProc_doWithNestedXConcurrent(t *testing.T) {
	t.Skip("disabled for causing CI timeouts.")
	config := defaultConfig
	config.actionQueueDepth = 0
	p := newConfigured(config)

	var wg sync.WaitGroup
	const CONC = 20
	wg.Add(CONC)

	// this test spins up TONS of goroutines that can take a little while to execute on a busy
	// CI server. drawing the line at 10s because I've never seen it take anywhere near that long.
	timeout := 10 * time.Second

	for i := 0; i < CONC; i++ {
		i := i
		errOnce := NewErrorOnce(p.Done())
		runtime.After(func() { runDelegationTest(t, p, fmt.Sprintf("nested%d", i), errOnce, timeout) }).Then(wg.Done)
		go func() {
			select {
			case err := <-errOnce.Err():
				if err != nil {
					t.Fatalf("delegate %d: unexpected error: %v", i, err)
				}
			case <-time.After(2 * timeout):
				t.Fatalf("delegate %d: timed out waiting for doer result", i)
			}
		}()
	}
	ch := runtime.After(wg.Wait)
	fatalAfter(t, ch, 2*timeout, "timed out waiting for concurrent delegates")

	<-p.End()
	fatalAfter(t, p.Done(), 5*time.Second, "timed out waiting for process death")
}

func (self *procImpl) begin() runtime.Signal {
	if !self.state.transition(stateNew, stateRunning) {
		panic(fmt.Errorf("failed to transition from New to Idle state"))
	}
	defer log.V(2).Infof("started process %d", self.pid)
	var entered runtime.Latch

	// execute actions on the backlog chan
	return runtime.After(func() {
		runtime.Until(func() {
			if entered.Acquire() {
				close(self.running)
				self.wg.Add(1)
			}
			for action := range self.backlog {
				select {
				case <-self.terminate:
					return
				default:
					// signal to indicate there's room in the backlog now
					self.changed.Broadcast()
					// rely on Until to handle action panics
					action()
				}
			}
		}, self.actionHandlerCrashDelay, self.terminate)
	}).Then(func() {
		log.V(2).Infof("finished processing action backlog for process %d", self.pid)
		if !entered.Acquire() {
			self.wg.Done()
		}
	})
}

func TestProc_multiAction(t *testing.T) {
	p := New()
	const COUNT = 10
	var called sync.WaitGroup
	called.Add(COUNT)

	// test FIFO property
	next := 0
	for i := 0; i < COUNT; i++ {
		log.Infof("do'ing deferred action %d", i)
		idx := i
		err := p.Do(func() {
			defer called.Done()
			log.Infof("deferred action invoked")
			if next != idx {
				t.Fatalf("expected index %d instead of %d", idx, next)
			}
			next++
		})
		if err != nil {
			t.Fatalf("unexpected error: %v", err)
		}
	}

	fatalAfter(t, runtime.After(called.Wait), 2*time.Second, "timed out waiting for deferred actions to be invoked")

	p.End()

	fatalAfter(t, p.Done(), 5*time.Second, "timed out waiting for process death")
}

func TestProc_manyEndings(t *testing.T) {
	p := New()
	const COUNT = 20
	var wg sync.WaitGroup
	wg.Add(COUNT)
	for i := 0; i < COUNT; i++ {
		runtime.On(p.End(), wg.Done)
	}
	fatalAfter(t, runtime.After(wg.Wait), 5*time.Second, "timed out waiting for loose End()s")
	fatalAfter(t, p.Done(), 5*time.Second, "timed out waiting for process death")
}

// MergeOutput waits for the given tasks to complete. meanwhile it logs each time a task
// process completes or generates an error. when shouldQuit closes, tasks are canceled and this
// func eventually returns once all ongoing event handlers have completed running.
func MergeOutput(tasks []*Task, shouldQuit <-chan struct{}) Events {
	tc := make(chan *Completion)

	var waitForTasks sync.WaitGroup
	waitForTasks.Add(len(tasks))

	for _, t := range tasks {
		t := t
		// translate task dead signal into Done
		go func() {
			<-t.done
			waitForTasks.Done()
		}()
		// fan-in task completion and error events to tc, ec
		go t.forwardUntil(tc, shouldQuit)
	}

	tclistener := make(chan *Completion)
	done := runtime.After(func() {
		completionFinished := runtime.After(func() {
			defer close(tclistener)
			forwardCompletionUntil(tc, tclistener, nil, shouldQuit, func(tt *Completion, shutdown bool) {
				prefix := ""
				if shutdown {
					prefix = "(shutdown) "
				}
				log.Infof(prefix+"task %q exited with status %d", tt.name, tt.code)
			})
		})
		waitForTasks.Wait()
		close(tc)
		<-completionFinished
	})
	ei := newEventsImpl(tclistener, done)
	return ei
}

// spawns a go-routine to watch for unscheduled pods and queue them up
// for scheduling. returns immediately.
func (q *queuer) Run(done <-chan struct{}) {
	go runtime.Until(func() {
		log.Info("Watching for newly created pods")
		q.lock.Lock()
		defer q.lock.Unlock()

		for {
			// limit blocking here for short intervals so that scheduling
			// may proceed even if there have been no recent pod changes
			p := q.podUpdates.Await(enqueuePopTimeout)
			if p == nil {
				signalled := runtime.After(q.deltaCond.Wait)
				// we've yielded the lock
				select {
				case <-time.After(enqueueWaitTimeout):
					q.deltaCond.Broadcast() // abort Wait()
					<-signalled             // wait for lock re-acquisition
					log.V(4).Infoln("timed out waiting for a pod update")
				case <-signalled:
					// we've acquired the lock and there may be
					// changes for us to process now
				}
				continue
			}

			pod := p.(*Pod)
			if recoverAssignedSlave(pod.Pod) != "" {
				log.V(3).Infof("dequeuing assigned pod for scheduling: %v", pod.Pod.Name)
				q.dequeue(pod.GetUID())
			} else if pod.InGracefulTermination() {
				// pods which are pre-scheduled (i.e. NodeName is set) may be gracefully deleted,
				// even though they are not running yet.
				log.V(3).Infof("dequeuing graceful deleted pre-scheduled pod for scheduling: %v", pod.Pod.Name)
				q.dequeue(pod.GetUID())
			} else {
				// use ReplaceExisting because we are always pushing the latest state
				now := time.Now()
				pod.deadline = &now
				if q.podQueue.Offer(pod, queue.ReplaceExisting) {
					q.unscheduledCond.Broadcast()
					log.V(3).Infof("queued pod for scheduling: %v", pod.Pod.Name)
				} else {
					log.Warningf("failed to queue pod for scheduling: %v", pod.Pod.Name)
				}
			}
		}
	}, 1*time.Second, done)
}

// Notify runs Elect() on m, and calls Start()/Stop() on s when the
// elected master starts/stops matching 'id'. Never returns.
func Notify(m MasterElector, path, id string, s Service, abort <-chan struct{}) {
	n := &notifier{id: Master(id), service: s, masters: make(chan Master, 1)}
	finished := runtime.After(func() {
		runtime.Until(func() {
			for {
				w := m.Elect(path, id)
				for {
					select {
					case <-abort:
						return
					case event, open := <-w.ResultChan():
						if !open {
							break
						}
						if event.Type != watch.Modified {
							continue
						}
						electedMaster, ok := event.Object.(Master)
						if !ok {
							glog.Errorf("Unexpected object from election channel: %v", event.Object)
							break
						}

					sendElected:
						for {
							select {
							case <-abort:
								return
							case n.masters <- electedMaster:
								break sendElected
							default: // ring full, discard old value and add the new
								select {
								case <-abort:
									return
								case <-n.masters:
								default: // ring was cleared for us?!
								}
							}
						}
					}
				}
			}
		}, 0, abort)
	})
	runtime.Until(func() { n.serviceLoop(finished) }, 0, abort)
}

// OnError spawns a goroutine that waits for an error. if a non-nil error is read from
// the channel then the handler func is invoked, otherwise (nil error or closed chan)
// the handler is skipped. if a nil handler is specified then it's not invoked.
// the signal chan that's returned closes once the error process logic (and handler,
// if any) has completed.
func OnError(ch <-chan error, f func(error), abort <-chan struct{}) <-chan struct{} {
	return runtime.After(func() {
		if ch == nil {
			return
		}
		select {
		case err, ok := <-ch:
			if ok && err != nil && f != nil {
				f(err)
			}
		case <-abort:
			if f != nil {
				f(errProcessTerminated)
			}
		}
	})
}

func Test(t *testing.T) {
	m := NewFake()
	changes := make(chan bool, 1500)
	done := make(chan struct{})
	s := &slowService{t: t, changes: changes, done: done}

	// change master to "notme" such that the initial m.Elect call inside Notify
	// will trigger an obversable event. We will wait for it to make sure the
	// Notify loop will see those master changes triggered by the go routine below.
	m.ChangeMaster(Master("me"))
	temporaryWatch := m.mux.Watch()
	ch := temporaryWatch.ResultChan()

	notifyDone := runtime.After(func() { Notify(m, "", "me", s, done) })

	// wait for the event triggered by the initial m.Elect of Notify. Then drain
	// the channel to not block anything.
	<-ch
	temporaryWatch.Stop()
	for i := 0; i < len(ch); i += 1 { // go 1.3 and 1.4 compatible loop
		<-ch
	}

	go func() {
		defer close(done)
		for i := 0; i < 500; i++ {
			for _, key := range []string{"me", "notme", "alsonotme"} {
				m.ChangeMaster(Master(key))
			}
		}
	}()

	<-notifyDone
	close(changes)

	changesNum := len(changes)
	if changesNum > 1000 || changesNum == 0 {
		t.Errorf("unexpected number of changes: %v", changesNum)
	}
}

// Notify runs Elect() on m, and calls Start()/Stop() on s when the
// elected master starts/stops matching 'id'. Never returns.
func Notify(m MasterElector, path, id string, s Service, abort <-chan struct{}) {
	n := &notifier{id: Master(id), service: s}
	n.changed = make(chan struct{})
	finished := runtime.After(func() {
		runtime.Until(func() {
			for {
				w := m.Elect(path, id)
				for {
					select {
					case <-abort:
						return
					case event, open := <-w.ResultChan():
						if !open {
							break
						}
						if event.Type != watch.Modified {
							continue
						}
						electedMaster, ok := event.Object.(Master)
						if !ok {
							glog.Errorf("Unexpected object from election channel: %v", event.Object)
							break
						}

						n.lock.Lock()
						n.desired = electedMaster
						n.lock.Unlock()

						// notify serviceLoop, but don't block. If a change
						// is queued already it will see the new n.desired.
						select {
						case n.changed <- struct{}{}:
						}
					}
				}
			}
		}, 0, abort)
	})
	runtime.Until(func() { n.serviceLoop(finished) }, 0, abort)
}

// implementation of scheduling plugin's NextPod func; see k8s plugin/pkg/scheduler
func (q *queuer) yield() *api.Pod {
	log.V(2).Info("attempting to yield a pod")
	q.lock.Lock()
	defer q.lock.Unlock()

	for {
		// limit blocking here to short intervals so that we don't block the
		// enqueuer Run() routine for very long
		kpod := q.podQueue.Await(yieldPopTimeout)
		if kpod == nil {
			signalled := runtime.After(q.unscheduledCond.Wait)
			// lock is yielded at this point and we're going to wait for either
			// a timeout, or a signal that there's data
			select {
			case <-time.After(yieldWaitTimeout):
				q.unscheduledCond.Broadcast() // abort Wait()
				<-signalled                   // wait for the go-routine, and the lock
				log.V(4).Infoln("timed out waiting for a pod to yield")
			case <-signalled:
				// we have acquired the lock, and there
				// may be a pod for us to pop now
			}
			continue
		}

		pod := kpod.(*Pod).Pod
		if podName, err := cache.MetaNamespaceKeyFunc(pod); err != nil {
			log.Warningf("yield unable to understand pod object %+v, will skip: %v", pod, err)
		} else if !q.podUpdates.Poll(podName, queue.POP_EVENT) {
			log.V(1).Infof("yield popped a transitioning pod, skipping: %+v", pod)
		} else if annotatedForExecutor(pod) {
			// should never happen if enqueuePods is filtering properly
			log.Warningf("yield popped an already-scheduled pod, skipping: %+v", pod)
		} else {
			return pod
		}
	}
}

// intended to be run with -race
func TestProc_doWithNestedXConcurrent(t *testing.T) {
	config := defaultConfig
	config.actionQueueDepth = 4000
	p := newConfigured(config)

	var wg sync.WaitGroup
	const CONC = 20
	wg.Add(CONC)

	for i := 0; i < CONC; i++ {
		i := i
		errOnce := NewErrorOnce(p.Done())
		runtime.After(func() { runDelegationTest(t, p, fmt.Sprintf("nested%d", i), errOnce) }).Then(wg.Done)
		go func() {
			err, _ := <-errOnce.Err()
			if err != nil {
				t.Errorf("delegate %d: unexpected error: %v", i, err)
			}
		}()
	}
	wg.Wait()
	<-p.End()
	<-p.Done()
}

// TestExecutorLaunchAndKillTask ensures that the executor is able to launch
// and kill tasks while properly bookkeping its tasks.
func TestExecutorLaunchAndKillTask(t *testing.T) {
	// create a fake pod watch. We use that below to submit new pods to the scheduler
	podListWatch := NewMockPodsListWatch(api.PodList{})

	// create fake apiserver
	testApiServer := NewTestServer(t, api.NamespaceDefault, &podListWatch.list)
	defer testApiServer.server.Close()

	mockDriver := &MockExecutorDriver{}
	updates := make(chan interface{}, 1024)
	config := Config{
		Docker:  dockertools.ConnectToDockerOrDie("fake://"),
		Updates: updates,
		APIClient: client.NewOrDie(&client.Config{
			Host:    testApiServer.server.URL,
			Version: testapi.Default.Version(),
		}),
		Kubelet: &fakeKubelet{
			Kubelet: &kubelet.Kubelet{},
			hostIP:  net.IPv4(127, 0, 0, 1),
		},
		PodStatusFunc: func(kl KubeletInterface, pod *api.Pod) (*api.PodStatus, error) {
			return &api.PodStatus{
				ContainerStatuses: []api.ContainerStatus{
					{
						Name: "foo",
						State: api.ContainerState{
							Running: &api.ContainerStateRunning{},
						},
					},
				},
				Phase: api.PodRunning,
			}, nil
		},
	}
	executor := New(config)

	executor.Init(mockDriver)
	executor.Registered(mockDriver, nil, nil, nil)

	select {
	case <-updates:
	case <-time.After(time.Second):
		t.Fatalf("Executor should send an initial update on Registration")
	}

	pod := NewTestPod(1)
	podTask, err := podtask.New(api.NewDefaultContext(), "",
		*pod, &mesosproto.ExecutorInfo{})
	assert.Equal(t, nil, err, "must be able to create a task from a pod")

	taskInfo := podTask.BuildTaskInfo()
	data, err := testapi.Default.Codec().Encode(pod)
	assert.Equal(t, nil, err, "must be able to encode a pod's spec data")
	taskInfo.Data = data
	var statusUpdateCalls sync.WaitGroup
	statusUpdateDone := func(_ mock.Arguments) { statusUpdateCalls.Done() }

	statusUpdateCalls.Add(1)
	mockDriver.On(
		"SendStatusUpdate",
		mesosproto.TaskState_TASK_STARTING,
	).Return(mesosproto.Status_DRIVER_RUNNING, nil).Run(statusUpdateDone).Once()

	statusUpdateCalls.Add(1)
	mockDriver.On(
		"SendStatusUpdate",
		mesosproto.TaskState_TASK_RUNNING,
	).Return(mesosproto.Status_DRIVER_RUNNING, nil).Run(statusUpdateDone).Once()

	executor.LaunchTask(mockDriver, taskInfo)

	assertext.EventuallyTrue(t, 5*time.Second, func() bool {
		executor.lock.Lock()
		defer executor.lock.Unlock()
		return len(executor.tasks) == 1 && len(executor.pods) == 1
	}, "executor must be able to create a task and a pod")

	gotPodUpdate := false
	select {
	case m := <-updates:
		update, ok := m.(kubelet.PodUpdate)
		if ok && len(update.Pods) == 1 {
			gotPodUpdate = true
		}
	case <-time.After(time.Second):
	}
	assert.Equal(t, true, gotPodUpdate,
		"the executor should send an update about a new pod to "+
			"the updates chan when creating a new one.")

	// Allow some time for asynchronous requests to the driver.
	finished := kmruntime.After(statusUpdateCalls.Wait)
	select {
	case <-finished:
	case <-time.After(5 * time.Second):
		t.Fatalf("timed out waiting for status update calls to finish")
	}
//.........這裏部分代碼省略.........

// TestExecutorLaunchAndKillTask ensures that the executor is able to launch tasks and generates
// appropriate status messages for mesos. It then kills the task and validates that appropriate
// actions are taken by the executor.
func TestExecutorLaunchAndKillTask(t *testing.T) {
	var (
		mockDriver = &MockExecutorDriver{}
		registry   = newFakeRegistry()
		executor   = New(Config{
			Docker:    dockertools.ConnectToDockerOrDie("fake://", 0),
			NodeInfos: make(chan NodeInfo, 1),
			Registry:  registry,
		})
		mockKubeAPI  = &mockKubeAPI{}
		pod          = NewTestPod(1)
		executorinfo = &mesosproto.ExecutorInfo{}
	)
	executor.kubeAPI = mockKubeAPI
	executor.Init(mockDriver)
	executor.Registered(mockDriver, nil, nil, nil)

	podTask, err := podtask.New(
		api.NewDefaultContext(),
		podtask.Config{
			Prototype:        executorinfo,
			HostPortStrategy: hostport.StrategyWildcard,
		},
		pod,
	)
	assert.Equal(t, nil, err, "must be able to create a task from a pod")

	pod.Annotations = map[string]string{
		"k8s.mesosphere.io/taskId": podTask.ID,
	}

	podTask.Spec = &podtask.Spec{Executor: executorinfo}
	taskInfo, err := podTask.BuildTaskInfo()
	assert.Equal(t, nil, err, "must be able to build task info")

	data, err := runtime.Encode(testapi.Default.Codec(), pod)
	assert.Equal(t, nil, err, "must be able to encode a pod's spec data")

	taskInfo.Data = data
	var statusUpdateCalls sync.WaitGroup
	statusUpdateCalls.Add(1)
	statusUpdateDone := func(_ mock.Arguments) { statusUpdateCalls.Done() }

	mockDriver.On(
		"SendStatusUpdate",
		mesosproto.TaskState_TASK_STARTING,
	).Return(mesosproto.Status_DRIVER_RUNNING, nil).Run(statusUpdateDone).Once()

	statusUpdateCalls.Add(1)
	mockDriver.On(
		"SendStatusUpdate",
		mesosproto.TaskState_TASK_RUNNING,
	).Return(mesosproto.Status_DRIVER_RUNNING, nil).Run(statusUpdateDone).Once()

	executor.LaunchTask(mockDriver, taskInfo)

	assertext.EventuallyTrue(t, wait.ForeverTestTimeout, func() bool {
		executor.lock.Lock()
		defer executor.lock.Unlock()
		return !registry.empty()
	}, "executor must be able to create a task and a pod")

	// simulate a pod source update; normally this update is generated when binding a pod
	err = registry.phaseChange(pod, api.PodPending)
	assert.NoError(t, err)

	// simulate a pod source update; normally this update is generated by the kubelet once the pod is healthy
	err = registry.phaseChange(pod, api.PodRunning)
	assert.NoError(t, err)

	// Allow some time for asynchronous requests to the driver.
	finished := kmruntime.After(statusUpdateCalls.Wait)
	select {
	case <-finished:
	case <-time.After(wait.ForeverTestTimeout):
		t.Fatalf("timed out waiting for status update calls to finish")
	}

	statusUpdateCalls.Add(1)
	mockDriver.On(
		"SendStatusUpdate",
		mesosproto.TaskState_TASK_KILLED,
	).Return(mesosproto.Status_DRIVER_RUNNING, nil).Run(statusUpdateDone).Once()

	// simulate what happens when the apiserver is told to delete a pod
	mockKubeAPI.On("killPod", pod.Namespace, pod.Name).Return(nil).Run(func(_ mock.Arguments) {
		registry.Remove(podTask.ID)
	})

	executor.KillTask(mockDriver, taskInfo.TaskId)
	assertext.EventuallyTrue(t, wait.ForeverTestTimeout, func() bool {
		executor.lock.Lock()
		defer executor.lock.Unlock()
		return registry.empty()
	}, "executor must be able to kill a created task and pod")

	// Allow some time for asynchronous requests to the driver.
//.........這裏部分代碼省略.........