return false
			}
			if tries.Add(-1) < 0 {
				return false
			}

			runtime.Semacquire(&sem)
			runtime.Semrelease1(&sem, false, 0)
			if runtime.MutexContended(runtime.SemRootLock(&sem)) {
				sawContention.Add(1)
			}
			return true
		}

		stks := [][]string{
			{
				"runtime.unlock",
				"runtime.semrelease1",

		}
	}

	startTheWorld(stw)
	return
}

type Mutex = mutex

var Lock = lock
var Unlock = unlock

var MutexContended = mutexContended

func SemRootLock(addr *uint32) *mutex {
	root := semtable.rootFor(addr)
	return &root.lock
}

var Semacquire = semacquire
var Semrelease1 = semrelease1

func SemNwait(addr *uint32) uint32 {