func (rw *rwmutex) unlock() {
	// Announce to readers that there is no active writer.
	r := rw.readerCount.Add(rwmutexMaxReaders)
	if r >= rwmutexMaxReaders {
		throw("unlock of unlocked rwmutex")
	}
	// Unblock blocked readers.
	lock(&rw.rLock)
	for rw.readers.ptr() != nil {
		reader := rw.readers.ptr()
		rw.readers = reader.schedlink
		reader.schedlink.set(nil)
		notewakeup(&reader.park)
		r -= 1

	EvGoBlock             // goroutine blocks [timestamp, reason, stack ID]
	EvGoUnblock           // goroutine is unblocked [timestamp, goroutine ID, goroutine seq, stack ID]
	EvGoSyscallBegin      // syscall enter [timestamp, P seq, stack ID]
	EvGoSyscallEnd        // syscall exit [timestamp]
	EvGoSyscallEndBlocked // syscall exit and it blocked at some point [timestamp]

	})

	// 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:
		}
	}

     * allows tasks in other projects to access the state of this project without deadlocks in cases where there are dependency cycles between projects. It also allows other non-taask work
     * to run while the task is blocked.
     *
     * <p>When parallel execution is not enabled, the lock is shared between projects within a build, and each build in the build tree has its own shared lock.
     */
    ResourceLock getTaskExecutionLock();

// from a placeholder node "arg_tensor_enqueue_<tensor_id>".
//
// `tensor` is still owned by the caller. This call will be blocked if the queue
// has reached its capacity, and will be unblocked when the queued tensors again
// drop below the capacity due to dequeuing.
//
// Tensors are dequeued via the corresponding TF dequeue op.
// TODO(hongm): Add support for `timeout_ms`.

	}
	defer runtime.SetMutexProfileFraction(0)

	m := new(Mutex)

	m.Lock()
	if m.TryLock() {
		t.Fatalf("TryLock succeeded with mutex locked")
	}
	m.Unlock()
	if !m.TryLock() {
		t.Fatalf("TryLock failed with mutex unlocked")
	}
	m.Unlock()

	c := make(chan bool)
	for i := 0; i < 10; i++ {
		go HammerMutex(m, 1000, c)
	}
	for i := 0; i < 10; i++ {
		<-c
	}
}

				// Don't profile ourselves.
				continue
			}

			lock(&mp.threadLock)
			// Do not profile threads blocked on Notes,
			// this includes idle worker threads,
			// idle timer thread, idle heap scavenger, etc.
			if mp.thread == 0 || mp.profilehz == 0 || mp.blocked {
				unlock(&mp.threadLock)
				continue
			}
			// Acquire our own handle to the thread.
			var thread uintptr

    //            (__)\       )\/\
    //                ||----w |
    //                ||     ||
    Runnable state = get();
    Blocker blocker = null;
    while (state instanceof Blocker || state == PARKED) {
      if (state instanceof Blocker) {
        blocker = (Blocker) state;
      }
      spinCount++;
      if (spinCount > MAX_BUSY_WAIT_SPINS) {
        /*

entirely.

If the program is started with a non-empty signal mask, some signals
will be explicitly unblocked as described above. If Notify is called
for a blocked signal, it will be unblocked. If, later, Reset is
called for that signal, or Stop is called on all channels passed to
Notify for that signal, the signal will once again be blocked.

# SIGPIPE

When a Go program writes to a broken pipe, the kernel will raise a
SIGPIPE signal.

    //            (__)\       )\/\
    //                ||----w |
    //                ||     ||
    Runnable state = get();
    Blocker blocker = null;
    while (state instanceof Blocker || state == PARKED) {
      if (state instanceof Blocker) {
        blocker = (Blocker) state;
      }
      spinCount++;
      if (spinCount > MAX_BUSY_WAIT_SPINS) {
        /*