// Transfer locked-ness to the new goroutine.
		// Save lock state to restore later.
		mp := gp.m
		if mp != gp.lockedm.ptr() {
			throw("inconsistent lockedm")
		}
		// Save the external lock count and clear it so
		// that it can't be unlocked from the debug call.
		// Note: we already locked internally to the thread,
		// so if we were locked before we're still locked now.

		casgstatus(gnext, _Gwaiting, _Grunnable)
		casgstatus(gnext, _Grunnable, _Grunning)
	}

	// Donate locked state.
	if locked {
		mp.lockedg.set(gnext)
		gnext.lockedm.set(mp)
	}

	// Release the trace locker. We've completed all the necessary transitions..
	if trace.ok() {
		traceRelease(trace)
	}

	// Switch to gnext. Does not return.
	gogo(&gnext.sched)

// will send SIGTRAP to thread ID tid. gp must be locked to its OS thread and
// running.
//
// On success, InjectDebugCall returns the panic value of fn or nil.
// If fn did not panic, its results will be available in args.
func InjectDebugCall(gp *g, fn any, regArgs *abi.RegArgs, stackArgs any, tkill func(tid int) error, returnOnUnsafePoint bool) (any, error) {
	if gp.lockedm == 0 {
		return nil, plainError("goroutine not locked to thread")

	wl := NewLRWMutex()
	var rl sync.Locker
	wlocked := make(chan bool, 1)
	rlocked := make(chan bool, 1)
	rl = wl.DRLocker()
	n := 10
	go func() {
		for i := 0; i < n; i++ {
			rl.Lock()
			rl.Lock()
			rlocked <- true
			wl.Lock()
			wlocked <- true
		}
	}()
	for i := 0; i < n; i++ {
		<-rlocked
		rl.Unlock()
		select {
		case <-wlocked:
			t.Fatal("RLocker() didn't read-lock it")

					break
				}
				v = atomic.Loaduintptr(&l.key)
				if v&locked == 0 {
					continue Loop
				}
			}
			if v&locked != 0 {
				// Queued. Wait.
				semasleep(-1)
				i = 0
			}
		}
	}
}

func unlock(l *mutex) {
	unlockWithRank(l)
}

// We might not be holding a p in this code.
//
//go:nowritebarrier
func unlock2(l *mutex) {
	gp := getg()
	var mp *m

	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)
	}
}

	}

	// blocking on locked file
	locked := make(chan struct{}, 1)
	go func() {
		bl, blerr := LockedOpenFile(f.Name(), os.O_WRONLY, 0o600)
		if blerr != nil {
			t.Error(blerr)
			return
		}
		locked <- struct{}{}
		if blerr = bl.Close(); blerr != nil {
			t.Error(blerr)
			return
		}
	}()

	select {
	case <-locked:
		t.Error("unexpected unblocking")

// relation at all.
//
// [the Go memory model]: https://go.dev/ref/mem
type Mutex struct {
	state int32
	sema  uint32
}

// A Locker represents an object that can be locked and unlocked.
type Locker interface {
	Lock()
	Unlock()
}

const (
	mutexLocked = 1 << iota // mutex is locked
	mutexWoken
	mutexStarving
	mutexWaiterShift = iota

	// Mutex fairness.
	//

		race.Acquire(unsafe.Pointer(&rw.writerSem))
	}
	return true
}

// Unlock unlocks rw for writing. It is a run-time error if rw is
// not locked for writing on entry to Unlock.
//
// As with Mutexes, a locked [RWMutex] is not associated with a particular
// goroutine. One goroutine may [RWMutex.RLock] ([RWMutex.Lock]) a RWMutex and then

	})

	// Wait until process Q has either failed or locked file B.
	// Otherwise, P.2 might not block on file B as intended.
locked:
	for {
		if _, err := os.Stat(filepath.Join(dir, "locked")); !os.IsNotExist(err) {
			break locked
		}
		timer := time.NewTimer(1 * time.Millisecond)
		select {
		case <-qDone:
			timer.Stop()
			break locked
		case <-timer.C:
		}
	}