Lock myLock = CycleDetectingLockFactory.newInstance(Policies.THROW).newReentrantLock("MyLock");
    lock03.lock();
    myLock.lock();
    lock03.unlock();

    PotentialDeadlockException expected =
        assertThrows(PotentialDeadlockException.class, () -> lock01.lock());
    checkMessage(
        expected,
        "MyLock -> OtherOrder.FIRST",
        "OtherOrder.THIRD -> MyLock",

		t.Fatalf("unexpected result. connection was online")
	}

	// Attempt all calls.
	_, err = lkClient.RLock(context.Background(), dsync.LockArgs{})
	if err == nil {
		t.Fatal("Expected for Rlock to fail")
	}

	_, err = lkClient.Lock(context.Background(), dsync.LockArgs{})
	if err == nil {
		t.Fatal("Expected for Lock to fail")
	}

	_, err = lkClient.RUnlock(context.Background(), dsync.LockArgs{})
	if err == nil {

		if err != nil {
			errResp(err)
			return
		}
	}

	nsLock := objectAPI.NewNSLock(minioMetaBucket, "health-check-in-progress")
	lkctx, err := nsLock.GetLock(ctx, newDynamicTimeout(deadline, deadline))
	if err != nil { // returns a locked lock
		errResp(err)
		return
	}

	defer nsLock.Unlock(lkctx)
	healthCtx, healthCancel := context.WithTimeout(lkctx.Context(), deadline)

	resp := lockRPCUnlock.NewResponse()
	_, err := l.ll.Unlock(context.Background(), *args)
	// Ignore the Unlock() "reply" return value because if err == nil, "reply" is always true
	// Consequently, if err != nil, reply is always false
	return l.makeResp(resp, err)
}

// RLockHandler - Acquires an RLock.
func (l *lockRESTServer) RLockHandler(args *dsync.LockArgs) (*dsync.LockResp, *grid.RemoteErr) {

			return false
		default:
			if lm.lock(id, source, isWriteLock) {
				return true
			}
			time.Sleep(time.Duration(r.Float64() * float64(lockRetryInterval)))
		}
	}
}

// Unlock unlocks the write lock.
//
// It is a run-time error if lm is not locked on entry to Unlock.
func (lm *LRWMutex) Unlock() {
	isWriteLock := true
	success := lm.unlock(isWriteLock)
	if !success {

		globalHTTPStats.incS3RequestsIncoming()

		if r.Header.Get(globalObjectPerfUserMetadata) == "" {
			if val := globalServiceFreeze.Load(); val != nil {
				if unlock, ok := val.(chan struct{}); ok && unlock != nil {
					// Wait until unfrozen.
					select {
					case <-unlock:
					case <-r.Context().Done():
						// if client canceled we don't need to wait here forever.
						return
					}
				}
			}
		}

		t.Fatal("Unexpected error", err)
	}
}

// Tests lock and unlock semantics.
func TestLockAndUnlock(t *testing.T) {
	f, err := os.CreateTemp("", "lock")
	if err != nil {
		t.Fatal(err)
	}
	f.Close()
	defer func() {
		err = os.Remove(f.Name())
		if err != nil {
			t.Fatal(err)
		}
	}()

	// lock the file
	l, err := LockedOpenFile(f.Name(), os.O_WRONLY, 0o600)
	if err != nil {

					cancel()
					exit = true
				}
			}
			metaMu.Unlock()
		}
	}()

	const retryDelay = 200 * time.Millisecond
	const maxTries = 5

	// Keep destination...
	// Write results to disk.
	bw := newMetacacheBlockWriter(entries, func(b *metacacheBlock) error {
		// if the block is 0 bytes and its a first block skip it.
		// skip only this for Transient caches.

	}
	ps.Lock()
	defer ps.Unlock()

	sub := &Sub[T]{ch: subCh, types: Mask(mask.Mask()), filter: filter}
	ps.subs = append(ps.subs, sub)

	// We hold a lock, so we are safe to update
	combined := Mask(atomic.LoadUint64(&ps.types))
	combined.Merge(Mask(mask.Mask()))
	atomic.StoreUint64(&ps.types, uint64(combined))

	go func() {
		<-doneCh

		ps.Lock()
		defer ps.Unlock()

	}
}

// IsSet will return whether the singleton has been set.
func (s *Singleton[T]) IsSet() bool {
	select {
	case <-s.set:
		return true
	default:
		return false
	}
}

// Set the value and unblock all Get requests.
// This may only be called once, a second call will panic.
func (s *Singleton[T]) Set(v *T) {
	s.v = v
	close(s.set)