Golang fslock.NewLock函数代码示例

func (s *fslockSuite) TestIsLockHeldTwoLocks(c *C) {
	dir := c.MkDir()
	lock1, err := fslock.NewLock(dir, "testing")
	c.Assert(err, IsNil)
	lock2, err := fslock.NewLock(dir, "testing")
	c.Assert(err, IsNil)

	err = lock1.Lock("")
	c.Assert(err, IsNil)
	c.Assert(lock2.IsLockHeld(), Equals, false)
}

func (s *fslockSuite) TestMessageAcrossLocks(c *C) {
	dir := c.MkDir()
	lock1, err := fslock.NewLock(dir, "testing")
	c.Assert(err, IsNil)
	lock2, err := fslock.NewLock(dir, "testing")
	c.Assert(err, IsNil)

	err = lock1.Lock("very busy")
	c.Assert(err, IsNil)
	c.Assert(lock2.Message(), Equals, "very busy")
}

func (s *fslockSuite) TestLockWithTimeoutLocked(c *C) {
	dir := c.MkDir()
	lock1, err := fslock.NewLock(dir, "testing")
	c.Assert(err, IsNil)
	lock2, err := fslock.NewLock(dir, "testing")
	c.Assert(err, IsNil)

	err = lock1.Lock("")
	c.Assert(err, IsNil)

	err = lock2.LockWithTimeout(10*time.Millisecond, "")
	c.Assert(err, Equals, fslock.ErrTimeout)
}

func (s *fslockSuite) TestNewLockWithExistingDir(c *C) {
	dir := c.MkDir()
	err := os.MkdirAll(dir, 0755)
	c.Assert(err, IsNil)
	_, err = fslock.NewLock(dir, "special")
	c.Assert(err, IsNil)
}

func (s *fslockSuite) TestTomb(c *C) {
	const timeToDie = 200 * time.Millisecond
	die := tomb.Tomb{}

	dir := c.MkDir()
	lock, err := fslock.NewLock(dir, "testing")
	c.Assert(err, IsNil)
	// Just use one lock, and try to lock it twice.
	err = lock.Lock("very busy")
	c.Assert(err, IsNil)

	checkTomb := func() error {
		select {
		case <-die.Dying():
			return tomb.ErrDying
		default:
			// no-op to fall through to return.
		}
		return nil
	}

	go func() {
		time.Sleep(timeToDie)
		die.Killf("time to die")
	}()

	err = lock.LockWithFunc("won't happen", checkTomb)
	c.Assert(err, Equals, tomb.ErrDying)
	c.Assert(lock.Message(), Equals, "very busy")

}

func (s *fslockSuite) TestUnlock(c *C) {
	dir := c.MkDir()
	lock, err := fslock.NewLock(dir, "testing")
	c.Assert(err, IsNil)

	err = lock.Unlock()
	c.Assert(err, Equals, fslock.ErrLockNotHeld)
}

func (s *fslockSuite) TestLockWithTimeoutUnlocked(c *C) {
	dir := c.MkDir()
	lock, err := fslock.NewLock(dir, "testing")
	c.Assert(err, IsNil)

	err = lock.LockWithTimeout(10*time.Millisecond, "")
	c.Assert(err, IsNil)
}

func (s *fslockSuite) TestNewLockWithExistingFileInPlace(c *C) {
	dir := c.MkDir()
	err := os.MkdirAll(dir, 0755)
	c.Assert(err, IsNil)
	path := path.Join(dir, "locks")
	err = ioutil.WriteFile(path, []byte("foo"), 0644)
	c.Assert(err, IsNil)

	_, err = fslock.NewLock(path, "special")
	c.Assert(err, ErrorMatches, `.* not a directory`)
}

// This test also happens to test that locks can get created when the parent
// lock directory doesn't exist.
func (s *fslockSuite) TestValidNamesLockDir(c *C) {

	for _, name := range []string{
		"a",
		"longer",
		"longer-with.special-characters",
	} {
		dir := c.MkDir()
		_, err := fslock.NewLock(dir, name)
		c.Assert(err, IsNil)
	}
}

func (s *fslockSuite) TestBreakLock(c *C) {
	dir := c.MkDir()
	lock1, err := fslock.NewLock(dir, "testing")
	c.Assert(err, IsNil)
	lock2, err := fslock.NewLock(dir, "testing")
	c.Assert(err, IsNil)

	err = lock1.Lock("")
	c.Assert(err, IsNil)

	err = lock2.BreakLock()
	c.Assert(err, IsNil)
	c.Assert(lock2.IsLocked(), Equals, false)

	// Normally locks are broken due to client crashes, not duration.
	err = lock1.Unlock()
	c.Assert(err, Equals, fslock.ErrLockNotHeld)

	// Breaking a non-existant isn't an error
	err = lock2.BreakLock()
	c.Assert(err, IsNil)
}

// getUniterLock grabs the "uniter-hook-execution" lock and holds it, or an error
func getUniterLock(dataDir, message string) (*fslock.Lock, error) {
	// Taken from worker/uniter/uniter.go setupLocks()
	lockDir := filepath.Join(dataDir, "locks")
	hookLock, err := fslock.NewLock(lockDir, "uniter-hook-execution")
	if err != nil {
		return nil, err
	}
	err = hookLock.LockWithTimeout(lockTimeout, message)
	if err != nil {
		return nil, err
	}
	return hookLock, nil
}

func (s *fslockSuite) TestLockBlocks(c *C) {

	dir := c.MkDir()
	lock1, err := fslock.NewLock(dir, "testing")
	c.Assert(err, IsNil)
	lock2, err := fslock.NewLock(dir, "testing")
	c.Assert(err, IsNil)

	acquired := make(chan struct{})
	err = lock1.Lock("")
	c.Assert(err, IsNil)

	go func() {
		lock2.Lock("")
		acquired <- struct{}{}
		close(acquired)
	}()

	// Waiting for something not to happen is inherently hard...
	select {
	case <-acquired:
		c.Fatalf("Unexpected lock acquisition")
	case <-time.After(coretesting.ShortWait):
		// all good
	}

	err = lock1.Unlock()
	c.Assert(err, IsNil)

	select {
	case <-acquired:
		// all good
	case <-time.After(coretesting.ShortWait):
		c.Fatalf("Expected lock acquisition")
	}

	c.Assert(lock2.IsLockHeld(), Equals, true)
}

func (s *fslockSuite) TestIsLockHeldBasics(c *C) {
	dir := c.MkDir()
	lock, err := fslock.NewLock(dir, "testing")
	c.Assert(err, IsNil)
	c.Assert(lock.IsLockHeld(), Equals, false)

	err = lock.Lock("")
	c.Assert(err, IsNil)
	c.Assert(lock.IsLockHeld(), Equals, true)

	err = lock.Unlock()
	c.Assert(err, IsNil)
	c.Assert(lock.IsLockHeld(), Equals, false)
}

func (s *fslockSuite) TestMessage(c *C) {
	dir := c.MkDir()
	lock, err := fslock.NewLock(dir, "testing")
	c.Assert(err, IsNil)
	c.Assert(lock.Message(), Equals, "")

	err = lock.Lock("my message")
	c.Assert(err, IsNil)
	c.Assert(lock.Message(), Equals, "my message")

	// Unlocking removes the message.
	err = lock.Unlock()
	c.Assert(err, IsNil)
	c.Assert(lock.Message(), Equals, "")
}

func (s *fslockSuite) TestInitialMessageWhenLocking(c *C) {
	dir := c.MkDir()
	lock, err := fslock.NewLock(dir, "testing")
	c.Assert(err, IsNil)

	err = lock.Lock("initial message")
	c.Assert(err, IsNil)
	c.Assert(lock.Message(), Equals, "initial message")

	err = lock.Unlock()
	c.Assert(err, IsNil)

	err = lock.LockWithTimeout(10*time.Millisecond, "initial timeout message")
	c.Assert(err, IsNil)
	c.Assert(lock.Message(), Equals, "initial timeout message")
}