wl := NewLRWMutex()
	var rl sync.Locker
	wlocked := make(chan bool, 1)
	rlocked := make(chan bool, 1)
	rl = wl.DRLocker()
	n := 10
	go func() {
		for range n {
			rl.Lock()
			rl.Lock()
			rlocked <- true
			wl.Lock()
			wlocked <- true
		}
	}()
	for range n {
		<-rlocked
		rl.Unlock()
		select {
		case <-wlocked:
			t.Fatal("RLocker() didn't read-lock it")
		default:
		}

	expected := true
	if locked != expected {
		t.Errorf("TestSimpleWriteLockAcquired(): \nexpected %#v\ngot      %#v", expected, locked)
	}
}

func TestSimpleWriteLockTimedOut(t *testing.T) {
	locked := testSimpleWriteLock(t, testDrwMutexAcquireTimeout)

	expected := false
	if locked != expected {
		t.Errorf("TestSimpleWriteLockTimedOut(): \nexpected %#v\ngot      %#v", expected, locked)
	}
}

			lm.ref = 1
			lm.isWriteLock = true
			locked = true
		}
	} else {
		if !lm.isWriteLock {
			lm.ref++
			locked = true
		}
	}

	return locked
}

const (
	lockRetryInterval = 50 * time.Millisecond
)

// lockLoop will acquire either a read or a write lock
//
// The call will block until the lock is granted using a built-in
// timing randomized back-off algorithm to try again until successful

			return
		}
		locked <- struct{}{}
		if blerr = bl.Close(); blerr != nil {
			t.Error(blerr)
			return
		}
	}()

	select {
	case <-locked:
		t.Error("unexpected unblocking")
	case <-time.After(100 * time.Millisecond):
	}

	// unlock
	if err = dupl.Close(); err != nil {
		t.Fatal(err)
	}

	// the previously blocked routine should be unblocked
	select {

	// In that case, the resource may or may not be unlocked.
	RUnlock(ctx context.Context, args LockArgs) (bool, error)

	// Do write unlock for given LockArgs. It should return
	// * a boolean to indicate success/failure of the operation
	// * an error on failure of unlock request operation.
	// Canceling the context will abort the remote call.
	// In that case, the resource may or may not be unlocked.

// open file descriptor.
package lock

import (
	"errors"
	"os"
	"sync"
)

// ErrAlreadyLocked is returned if the underlying fd is already locked.
var ErrAlreadyLocked = errors.New("file already locked")

// RLockedFile represents a read locked file, implements a special
// closer which only closes the associated *os.File when the ref count.
// has reached zero, i.e when all the readers have given up their locks.

    // after some period of time the runner thread should become blocked on the task because it is
    // waiting for the slow interrupting thread to complete Thread.interrupt
    awaitBlockedOnInstanceOf(runner, InterruptibleTask.Blocker.class);

    Blocker blocker = (Blocker) LockSupport.getBlocker(runner);
    Thread owner = blocker.getOwner();
    assertThat(owner).isSameInstanceAs(interrupter);

	}
	nsLk.ref++
	n.lockMap[resource] = nsLk
	n.lockMapMutex.Unlock()

	// Locking here will block (until timeout).
	if readLock {
		locked = nsLk.GetRLock(ctx, opsID, lockSource, timeout)
	} else {
		locked = nsLk.GetLock(ctx, opsID, lockSource, timeout)
	}

	if !locked { // We failed to get the lock
		// Decrement ref count since we failed to get the lock
		n.lockMapMutex.Lock()
		n.lockMap[resource].ref--

type LockArgs struct {
	// Unique ID of lock/unlock request.
	UID string

	// Resources contains single or multiple entries to be locked/unlocked.
	Resources []string

	// Owner represents unique ID for this instance, an owner who originally requested
	// the locked resource, useful primarily in figuring out stale locks.
	Owner string

	// Source contains the line number, function and file name of the code

	//   locker: A synchronization lock that is unlocked after initialization to avoid deadlocks.
	// Returns:
	//   *Stmt: A newly created statement object for executing SQL operations.
	//   error: An error if the statement preparation fails.
	New(ctx context.Context, key string, isTransaction bool, connPool ConnPool, locker sync.Locker) (*Stmt, error)