Golang Server.LockKeyspaceForAction方法代码示例

// LockKeyspace will lock the keyspace in the topology server.
// UnlockKeyspace should be called if this returns no error.
func (n *ActionNode) LockKeyspace(ctx context.Context, ts topo.Server, keyspace string) (lockPath string, err error) {
	log.Infof("Locking keyspace %v for action %v", keyspace, n.Action)

	span := trace.NewSpanFromContext(ctx)
	span.StartClient("TopoServer.LockKeyspaceForAction")
	span.Annotate("action", n.Action)
	span.Annotate("keyspace", keyspace)
	defer span.Finish()

	return ts.LockKeyspaceForAction(ctx, keyspace, n.ToJSON())
}

// LockKeyspace will lock the keyspace in the topology server.
// UnlockKeyspace should be called if this returns no error.
func (n *ActionNode) LockKeyspace(ctx context.Context, ts topo.Server, keyspace string) (lockPath string, err error) {
	log.Infof("Locking keyspace %v for action %v", keyspace, n.Action)

	ctx, cancel := context.WithTimeout(ctx, *LockTimeout)
	defer cancel()

	span := trace.NewSpanFromContext(ctx)
	span.StartClient("TopoServer.LockKeyspaceForAction")
	span.Annotate("action", n.Action)
	span.Annotate("keyspace", keyspace)
	defer span.Finish()

	j, err := n.ToJSON()
	if err != nil {
		return "", err
	}
	return ts.LockKeyspaceForAction(ctx, keyspace, j)
}

// checkKeyspaceLockUnblocks makes sure that a routine waiting on a lock
// is unblocked when another routine frees the lock
func checkKeyspaceLockUnblocks(ctx context.Context, t *testing.T, ts topo.Server) {
	unblock := make(chan struct{})
	finished := make(chan struct{})

	// as soon as we're unblocked, we try to lock the keyspace
	go func() {
		<-unblock
		lockPath, err := ts.LockKeyspaceForAction(ctx, "test_keyspace", "fake-content")
		if err != nil {
			t.Fatalf("LockKeyspaceForAction(test_keyspace) failed: %v", err)
		}
		if err = ts.UnlockKeyspaceForAction(ctx, "test_keyspace", lockPath, "fake-results"); err != nil {
			t.Fatalf("UnlockKeyspaceForAction(test_keyspace): %v", err)
		}
		close(finished)
	}()

	// lock the keyspace
	lockPath2, err := ts.LockKeyspaceForAction(ctx, "test_keyspace", "fake-content")
	if err != nil {
		t.Fatalf("LockKeyspaceForAction(test_keyspace) failed: %v", err)
	}

	// unblock the go routine so it starts waiting
	close(unblock)

	// sleep for a while so we're sure the go routine is blocking
	time.Sleep(timeUntilLockIsTaken)

	if err = ts.UnlockKeyspaceForAction(ctx, "test_keyspace", lockPath2, "fake-results"); err != nil {
		t.Fatalf("UnlockKeyspaceForAction(test_keyspace): %v", err)
	}

	timeout := time.After(10 * time.Second)
	select {
	case <-finished:
	case <-timeout:
		t.Fatalf("unlocking timed out")
	}
}

func checkKeyspaceLockTimeout(ctx context.Context, t *testing.T, ts topo.Server) {
	lockPath, err := ts.LockKeyspaceForAction(ctx, "test_keyspace", "fake-content")
	if err != nil {
		t.Fatalf("LockKeyspaceForAction: %v", err)
	}

	// test we can't take the lock again
	fastCtx, cancel := context.WithTimeout(ctx, timeUntilLockIsTaken)
	if _, err := ts.LockKeyspaceForAction(fastCtx, "test_keyspace", "unused-fake-content"); err != topo.ErrTimeout {
		t.Fatalf("LockKeyspaceForAction(again): %v", err)
	}
	cancel()

	// test we can interrupt taking the lock
	interruptCtx, cancel := context.WithCancel(ctx)
	go func() {
		time.Sleep(timeUntilLockIsTaken)
		cancel()
	}()
	if _, err := ts.LockKeyspaceForAction(interruptCtx, "test_keyspace", "unused-fake-content"); err != topo.ErrInterrupted {
		t.Fatalf("LockKeyspaceForAction(interrupted): %v", err)
	}

	if err := ts.UnlockKeyspaceForAction(ctx, "test_keyspace", lockPath, "fake-results"); err != nil {
		t.Fatalf("UnlockKeyspaceForAction(): %v", err)
	}

	// test we can't unlock again
	if err := ts.UnlockKeyspaceForAction(ctx, "test_keyspace", lockPath, "fake-results"); err == nil {
		t.Fatalf("UnlockKeyspaceForAction(again) worked")
	}
}

func CheckKeyspaceLock(t *testing.T, ts topo.Server) {
	if err := ts.CreateKeyspace("test_keyspace", &topo.Keyspace{}); err != nil {
		t.Fatalf("CreateKeyspace: %v", err)
	}

	interrupted := make(chan struct{}, 1)
	lockPath, err := ts.LockKeyspaceForAction("test_keyspace", "fake-content", 5*time.Second, interrupted)
	if err != nil {
		t.Fatalf("LockKeyspaceForAction: %v", err)
	}

	// test we can't take the lock again
	if _, err := ts.LockKeyspaceForAction("test_keyspace", "unused-fake-content", time.Second/10, interrupted); err != topo.ErrTimeout {
		t.Errorf("LockKeyspaceForAction(again): %v", err)
	}

	// test we can interrupt taking the lock
	go func() {
		time.Sleep(time.Second / 10)
		close(interrupted)
	}()
	if _, err := ts.LockKeyspaceForAction("test_keyspace", "unused-fake-content", 5*time.Second, interrupted); err != topo.ErrInterrupted {
		t.Errorf("LockKeyspaceForAction(interrupted): %v", err)
	}

	if err := ts.UnlockKeyspaceForAction("test_keyspace", lockPath, "fake-results"); err != nil {
		t.Errorf("UnlockKeyspaceForAction(): %v", err)
	}

	// test we can't unlock again
	if err := ts.UnlockKeyspaceForAction("test_keyspace", lockPath, "fake-results"); err == nil {
		t.Error("UnlockKeyspaceForAction(again) worked")
	}

	// test we can't lock a non-existing keyspace
	interrupted = make(chan struct{}, 1)
	if _, err := ts.LockKeyspaceForAction("test_keyspace_666", "fake-content", 5*time.Second, interrupted); err == nil {
		t.Fatalf("LockKeyspaceForAction(test_keyspace_666) worked for non-existing keyspace")
	}
}

// checkKeyspaceLockMissing makes sure we can't lock a non-existing keyspace
func checkKeyspaceLockMissing(ctx context.Context, t *testing.T, ts topo.Server) {
	if _, err := ts.LockKeyspaceForAction(ctx, "test_keyspace_666", "fake-content"); err == nil {
		t.Fatalf("LockKeyspaceForAction(test_keyspace_666) worked for non-existing keyspace")
	}
}

// LockKeyspace will lock the keyspace in the topology server.
// UnlockKeyspace should be called if this returns no error.
func (n *ActionNode) LockKeyspace(ts topo.Server, keyspace string, lockTimeout time.Duration, interrupted chan struct{}) (lockPath string, err error) {
	log.Infof("Locking keyspace %v for action %v", keyspace, n.Action)
	return ts.LockKeyspaceForAction(keyspace, n.ToJson(), lockTimeout, interrupted)
}