// It can be thought of as like a special channel that always has
// a goroutine blocked on it. If another goroutine calls coroswitch(c),
// the caller becomes the goroutine blocked in c, and the goroutine
// formerly blocked in c starts running.
// These switches continue until a call to coroexit(c),
// which ends the use of the coro by releasing the blocked
// goroutine in c and exiting the current goroutine.
//

// 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.
	//

	return r < 0 && r+rwmutexMaxReaders > 0
}

// RLocker returns a [Locker] interface that implements
// the [RWMutex.Lock] and [RWMutex.Unlock] methods by calling rw.RLock and rw.RUnlock.
func (rw *RWMutex) RLocker() Locker {
	return (*rlocker)(rw)
}

type rlocker RWMutex

func (r *rlocker) Lock()   { (*RWMutex)(r).RLock() }

	state atomic.Uint64 // high 32 bits are counter, low 32 bits are waiter count.
	sema  uint32
}

// Add adds delta, which may be negative, to the [WaitGroup] counter.
// If the counter becomes zero, all goroutines blocked on [WaitGroup.Wait] are released.
// If the counter goes negative, Add panics.
//
// Note that calls with a positive delta that occur when the counter is zero

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.

		}
	default:
		m.disconnect("handler blocked", true)
	}
}

func (m *muxServer) unblockSend(seq uint32) {
	if !m.checkSeq(seq) {
		return
	}
	m.recvMu.Lock()
	defer m.recvMu.Unlock()
	if m.outBlock == nil {
		// Closed
		return
	}
	select {
	case m.outBlock <- struct{}{}:
	default:
		gridLogIf(m.ctx, errors.New("output unblocked overflow"))
	}
}

   * state: BLOCKED, WAITING, or TIMED_WAITING.
   */
  void waitForThreadToEnterWaitState(Thread thread, long timeoutMillis) {
    long startTime = System.nanoTime();
    for (; ; ) {
      Thread.State s = thread.getState();
      if (s == Thread.State.BLOCKED || s == Thread.State.WAITING || s == Thread.State.TIMED_WAITING)
        return;

  }

  /**
   * Asserts that a prior call that had caused this thread to block or wait has since returned
   * normally.
   */
  public void assertPriorCallReturns(@Nullable String methodName) throws Exception {
    assertEquals(null, getResponse(methodName).getResult());
  }

  /**
   * Asserts that a prior call that had caused this thread to block or wait has since returned the
   * expected boolean value.
   */

	// Check that remote is canceled.
	<-serverCanceled
	close(nowBlocking)
}

// testServerStreamPingRunning will test if server and client handle ping even when blocked.
func testServerStreamPingRunning(t *testing.T, local, remote *Manager, inCap int, blockResp, blockReq bool) {
	defer testlogger.T.SetErrorTB(t)()
	errFatal := func(err error) {
		t.Helper()
		if err != nil {
			t.Fatal(err)
		}
	}

  }

  /**
   * Asserts that a prior call that had caused this thread to block or wait has since returned
   * normally.
   */
  public void assertPriorCallReturns(@Nullable String methodName) throws Exception {
    assertEquals(null, getResponse(methodName).getResult());
  }

  /**
   * Asserts that a prior call that had caused this thread to block or wait has since returned the
   * expected boolean value.
   */