if r := rw.readerCount.Add(-1); r < 0 {
		if r+1 == 0 || r+1 == -rwmutexMaxReaders {
			throw("runlock of unlocked rwmutex")
		}
		// A writer is pending.
		if rw.readerWait.Add(-1) == 0 {
			// The last reader unblocks the writer.
			lock(&rw.rLock)
			w := rw.writer.ptr()
			if w != nil {
				notewakeup(&w.park)
			}
			unlock(&rw.rLock)
		}
	}
	releaseLockRankAndM(rw.readRank)
}

	if msg.DeadlineMS == 0 || msg.DeadlineMS > uint32(4*c.clientPingInterval/time.Millisecond) {
		go func() {
			wg.Wait()
			m.checkRemoteAlive()
		}()
	}
	return &m
}

// handleInbound sends unblocks when we have delivered the message to the handler.
func (m *muxServer) handleInbound(c *Connection, inbound <-chan []byte, handlerIn chan<- []byte) {
	for {
		select {
		case <-m.ctx.Done():
			return

type lifecycleSignal interface {
	// Signal signals the event, indicating that the event has occurred.
	// Signal is idempotent, once signaled the event stays signaled and
	// it immediately unblocks any goroutine waiting for this event.
	Signal()

	// Signaled returns a channel that is closed when the underlying event
	// has been signaled. Successive calls to Signaled return the same value.
	Signaled() <-chan struct{}

	mfe.blockIPTables(true)
	ipt.DeleteChain(TableNAT, canary)
	if err := waitForBlocked(mfe); err != nil {
		t.Errorf("failed waiting for monitor to be blocked from monitoring: %v", err)
	}

	// After unblocking the monitor, it should now reload
	mfe.blockIPTables(false)

	if err := waitForReloads(&reloads, 2); err != nil {
		t.Errorf("got unexpected number of reloads after slow flush: %v", err)
	}

	if r+1 == 0 || r+1 == -rwmutexMaxReaders {
		race.Enable()
		fatal("sync: RUnlock of unlocked RWMutex")
	}
	// A writer is pending.
	if rw.readerWait.Add(-1) == 0 {
		// The last reader unblocks the writer.
		runtime_Semrelease(&rw.writerSem, false, 1)
	}
}

// Lock locks rw for writing.
// If the lock is already locked for reading or writing,
// Lock blocks until the lock is available.