lm.ref = 0
	lm.isWriteLock = false
}

// DRLocker returns a sync.Locker interface that implements
// the Lock and Unlock methods by calling drw.RLock and drw.RUnlock.
func (lm *LRWMutex) DRLocker() sync.Locker {
	return (*drlocker)(lm)
}

type drlocker LRWMutex

func (dr *drlocker) Lock()   { (*LRWMutex)(dr).RLock() }

}

// Borrowed from rwmutex_test.go
func TestDRLocker(t *testing.T) {
	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()