go func() {
		if locked {
			runtime.LockOSThread()
		}
		for {
			select {
			case <-c:
				cack <- true
				return
			default:
				runtime.Gosched()
			}
		}
	}()
	time.Sleep(10 * time.Millisecond)
	c <- true
	<-cack
}

func TestYieldLocked(t *testing.T) {
	const N = 10
	c := make(chan bool)
	go func() {
		runtime.LockOSThread()
		for i := 0; i < N; i++ {
			runtime.Gosched()

	}
}

func TestDebugLogWraparound(t *testing.T) {
	skipDebugLog(t)

	// Make sure we don't switch logs so it's easier to fill one up.
	runtime.LockOSThread()
	defer runtime.UnlockOSThread()

	runtime.ResetDebugLog()
	var longString = strings.Repeat("a", 128)
	var want strings.Builder
	for i, j := 0, 0; j < 2*runtime.DebugLogBytes; i, j = i+1, j+len(longString) {

func (k Key) ReadSubKeyNames() ([]string, error) {
	// RegEnumKeyEx must be called repeatedly and to completion.
	// During this time, this goroutine cannot migrate away from
	// its current thread. See #49320.
	runtime.LockOSThread()
	defer runtime.UnlockOSThread()

	names := make([]string, 0)
	// Registry key size limit is 255 bytes and described there:
	// https://learn.microsoft.com/en-us/windows/win32/sysinfo/registry-element-size-limits

				if e != 0 {
					return e
				}
				return nil
			},
		},
	}

	waiter := func(q <-chan uintptr, r chan<- uintptr, once bool) {
		for x := range q {
			runtime.LockOSThread()
			v, _, e := syscall.Syscall(syscall.SYS_PRCTL, PR_GET_KEEPCAPS, 0, 0)
			if e != 0 {
				t.Errorf("tid=%d prctl(PR_GET_KEEPCAPS) failed: %v", syscall.Gettid(), e)
			} else if x != v {

		runtime.Close(w)
	}()
	runtime.Closeonexec(r)
	runtime.Closeonexec(w)

	var want, got int64
	var wg sync.WaitGroup
	ready := make(chan *runtime.M)
	wg.Add(1)
	go func() {
		runtime.LockOSThread()
		want, got = runtime.WaitForSigusr1(r, w, func(mp *runtime.M) {
			ready <- mp
		})
		runtime.UnlockOSThread()
		wg.Done()
	}()
	waitingM := <-ready
	runtime.SendSigusr1(waitingM)

	if runtime.GOOS == "android" {
		return
	}
	// Used to panic because of the UnlockOSThread below.
	C.lockOSThreadC()
}

//export lockOSThreadCallback
func lockOSThreadCallback() {
	runtime.LockOSThread()
	runtime.UnlockOSThread()
	go C.usleep(10000)
	runtime.Gosched()
}

// issue 4054 part 2 - part 1 in test.go

var issue4054b = []int{C.A, C.B, C.C, C.D, C.E, C.F, C.G, C.H, C.II, C.J}

// of goroutines. A Go program creates a new thread only when a goroutine
// is ready to run but all the existing threads are blocked in system calls, cgo calls,
// or are locked to other goroutines due to use of runtime.LockOSThread.
//
// SetMaxThreads is useful mainly for limiting the damage done by
// programs that create an unbounded number of threads. The idea is
// to take down the program before it takes down the operating system.

	// exitsyscall, since it would otherwise be free to move us to
	// a different M. The call to unlockOSThread is in this function
	// after cgocallbackg1, or in the case of panicking, in unwindm.
	lockOSThread()

	checkm := gp.m

	// Save current syscall parameters, so m.winsyscall can be
	// used again if callback decide to make syscall.
	winsyscall := gp.m.winsyscall

			// Warning: Do not call UnlockOSThread! Notably, netns.Do does call this.
			runtime.LockOSThread()
			if err := setupSandbox(); err != nil {
				return err
			}
			// Mark we have actually run the command. This lets us distinguish from a failure in setupSandbox() vs f()
			executed = true
			return f()

// new process, so it normally starts with the program name.
//
// If the calling goroutine has locked the operating system thread
// with [runtime.LockOSThread] and modified any inheritable OS-level
// thread state (for example, Linux or Plan 9 name spaces), the new
// process will inherit the caller's thread state.
//