)

// local lock servers
var globalLockServer *localLocker

// RWLocker - locker interface to introduce GetRLock, RUnlock.
type RWLocker interface {
	GetLock(ctx context.Context, timeout *dynamicTimeout) (lkCtx LockContext, timedOutErr error)
	Unlock(lkCtx LockContext)
	GetRLock(ctx context.Context, timeout *dynamicTimeout) (lkCtx LockContext, timedOutErr error)
	RUnlock(lkCtx LockContext)
}

)

func testSimpleWriteLock(t *testing.T, duration time.Duration) (locked bool) {
	ctx := t.Context()
	lrwm := NewLRWMutex()

	if !lrwm.GetRLock(ctx, "", "object1", time.Second) {
		panic("Failed to acquire read lock")
	}
	// fmt.Println("1st read lock acquired, waiting...")

	if !lrwm.GetRLock(ctx, "", "object1", time.Second) {
		panic("Failed to acquire read lock")
	}
	// fmt.Println("2nd read lock acquired, waiting...")

	ctx1, cancel1 := context.WithCancel(t.Context())
	if !drwm1.GetRLock(ctx1, cancel1, id, source, Options{Timeout: time.Second}) {
		panic("Failed to acquire read lock")
	}
	// fmt.Println("1st read lock acquired, waiting...")

	drwm2 := NewDRWMutex(ds, "simplelock")
	ctx2, cancel2 := context.WithCancel(t.Context())
	if !drwm2.GetRLock(ctx2, cancel2, id, source, Options{Timeout: time.Second}) {

	nsUnlocker := func() {}
	defer func() {
		if unlockOnDefer {
			nsUnlocker()
		}
	}()

	// Acquire lock
	if !opts.NoLock {
		lock := z.NewNSLock(bucket, object)
		lkctx, err := lock.GetRLock(ctx, globalOperationTimeout)
		if err != nil {
			return nil, err
		}
		ctx = lkctx.Context()
		nsUnlocker = func() { lock.RUnlock(lkctx) }
		unlockOnDefer = true
	}

		Timeout: drwMutexInfinite,
	})
}

// GetRLock tries to get a read lock on dm before the timeout elapses.
//
// If one or more read locks are already in use, it will grant another lock.
// Otherwise the calling go routine blocks until either the mutex becomes
// available and return success or more time has passed than the timeout
// value and return false.

	}

	dm := NewDRWMutex(ds, "aap")
	dm.refreshInterval = testDrwMutexRefreshInterval

	ctx, cancel := context.WithCancel(t.Context())

	if !dm.GetLock(ctx, cancel, id, source, Options{Timeout: 5 * time.Minute}) {
		t.Fatal("GetLock() should be successful")
	}

	// Make it run twice.
	timer := time.NewTimer(testDrwMutexRefreshInterval * 2)

	select {
	case <-ctx.Done():

	nsUnlocker := func() {}
	defer func() {
		if unlockOnDefer {
			nsUnlocker()
		}
	}()

	// Acquire lock
	if !opts.NoLock {
		lock := er.NewNSLock(bucket, object)
		lkctx, err := lock.GetRLock(ctx, globalOperationTimeout)
		if err != nil {
			return nil, err
		}
		ctx = lkctx.Context()

		// Release lock when the metadata is verified, and reader
		// is ready to be read.
		//

	plkctx, err := partIDLock.GetLock(ctx, globalOperationTimeout)
	if err != nil {
		return PartInfo{}, err
	}

	ctx = plkctx.Context()
	defer partIDLock.Unlock(plkctx)

	// Read lock for upload id, only held while reading the upload metadata.
	uploadIDRLock := er.NewNSLock(bucket, pathJoin(object, uploadID))
	rlkctx, err := uploadIDRLock.GetRLock(ctx, globalOperationTimeout)
	if err != nil {

        private void executePlan() {
            // Even if the build is halted, we still want to execute TEARDOWN and after:* steps
            // for proper cleanup, so we don't return early here
            Clock global = getClock(GLOBAL);
            global.start();
            lock.readLock().lock();
            try {
                // Process build steps in a logical order:

}

func runCallhome(ctx context.Context, objAPI ObjectLayer) bool {
	// Make sure only 1 callhome is running on the cluster.
	locker := objAPI.NewNSLock(minioMetaBucket, "callhome/runCallhome.lock")
	lkctx, err := locker.GetLock(ctx, callhomeLeaderLockTimeout)
	if err != nil {
		// lock timedout means some other node is the leader,
		// cycle back return 'true'
		return true
	}

	ctx = lkctx.Context()
	defer locker.Unlock(lkctx)