// only send so much data without being Recv'd before it starts blocking), along with the
		// backpressure provided by our channels, we have a risk of deadlock where both Xdsproxy and
		// Istiod are trying to Send, but both are blocked by gRPC backpressure until Recv() is called.
		// However, Recv can fail to be called by Send being blocked. This can be triggered by the two

		traceback(^uintptr(0), ^uintptr(0), 0, curgp)
	}

	// We can't call locking forEachG here because this may be during fatal
	// throw/panic, where locking could be out-of-order or a direct
	// deadlock.
	//
	// Instead, use forEachGRace, which requires no locking. We don't lock
	// against concurrent creation of new Gs, but even with allglock we may
	// miss Gs created after this loop.
	forEachGRace(func(gp *g) {

   * under {@code directExecutor}: Not only might the wait for a lock be long, but if the running
   * thread was holding a lock, the listener may deadlock or break lock isolation.
   *
   * <p>This instance is equivalent to:
   *
   * <pre>{@code
   * final class DirectExecutor implements Executor {
   *   public void execute(Runnable r) {
   *     r.run();

	cc := make(chan struct{})
	go func() {
		select {
		case <-cc:
			return
		case <-c:
			buf := make([]byte, 1<<20)
			stacklen := runtime.Stack(buf, true)
			fmt.Printf("=== Timeout, assuming deadlock ===\n*** goroutine dump...\n%s\n*** end\n", string(buf[:stacklen]))
			os.Exit(2)
		}
	}()
	return func() {
		close(cc)
	}

	cc := make(chan struct{})
	go func() {
		select {
		case <-cc:
			return
		case <-c:
			buf := make([]byte, 1<<20)
			stacklen := runtime.Stack(buf, true)
			fmt.Printf("=== Timeout, assuming deadlock ===\n*** goroutine dump...\n%s\n*** end\n", string(buf[:stacklen]))
			os.Exit(2)
		}
	}()
	return func() {
		close(cc)
	}
}

func assertNoActive(t *testing.T, c *Connection) {

   * under {@code directExecutor}: Not only might the wait for a lock be long, but if the running
   * thread was holding a lock, the listener may deadlock or break lock isolation.
   *
   * <p>This instance is equivalent to:
   *
   * <pre>{@code
   * final class DirectExecutor implements Executor {
   *   public void execute(Runnable r) {
   *     r.run();

		// these expectations of *libc code are mostly met by
		// the combined go+cgo system of threads. However,
		// when go causes a thread to exit, via a return from
		// mstart(), the combined runtime can deadlock if
		// these signals are blocked. Thus, don't block these
		// signals when exiting threads.
		// - glibc: SIGCANCEL (32), SIGSETXID (33)
		// - musl: SIGTIMER (32), SIGCANCEL (33), SIGSYNCCALL (34)

	for i := 0; i < 2; i++ {
		select {
		case err := <-errChan:
			if err != nil {
				t.Fatal(err)
			}
		case <-time.After(10 * time.Second):
			t.Fatal("deadlock")
		}
	}

	// Also test CloseWrite being called before the handshake is
	// finished:
	{
		ln2 := newLocalListener(t)
		defer ln2.Close()

		netConn, err := net.Dial("tcp", ln2.Addr().String())

		w.closeAfterReply = true
	}

	// We do this by default because there are a number of clients that
	// send a full request before starting to read the response, and they
	// can deadlock if we start writing the response with unconsumed body
	// remaining. See Issue 15527 for some history.
	//
	// If full duplex mode has been enabled with ResponseController.EnableFullDuplex,

	if err != nil {
		t.Fatalf("Couldn't create cacher: %v", err)
	}
	defer cacher.Stop()

	concurrency := 1000
	wg := sync.WaitGroup{}
	wg.Add(concurrency)

	// Ensure that test doesn't deadlock if cacher already processed everything
	// and get back into Pending state before some watches get called.
	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
	defer cancel()