So we have a dedicated thread for every socket that just reads frames and dispatches them.

The reader thread must never run application-layer code. Otherwise one slow stream can hold up the entire connection.

    @RepeatedTest(10)
    @DisplayName("Test thread safety")
    void testThreadSafety() throws InterruptedException {
        SimpleCircuitBreaker breaker = new SimpleCircuitBreaker("concurrent", 5, 3, 100);
        AtomicInteger successCount = new AtomicInteger(0);
        AtomicInteger failureCount = new AtomicInteger(0);

        // Create multiple threads
        Thread[] threads = new Thread[10];

            monitor.leave();
          }
        });
    awaitUninterruptibly(enteredLatch);
  }

  @CanIgnoreReturnValue
  static Thread startThread(Runnable runnable) {
    Thread thread = new Thread(runnable);
    thread.setDaemon(true);
    thread.start();
    return thread;
  }

  /**
   * Generates a test case verifying that calling any enterXxx, tryEnterXxx, or waitForXxx method

    }

    @Override
    public int size() {
      assertTrue(Thread.holdsLock(mutex));
      return super.size();
    }

    @Override
    public boolean isEmpty() {
      assertTrue(Thread.holdsLock(mutex));
      return super.isEmpty();
    }

    @Override
    public @Nullable V remove(Object object) {
      assertTrue(Thread.holdsLock(mutex));
      return super.remove(object);
    }

    @Override

      Thread.currentThread().interrupt();
      // better than `end > System.nanoTime()` because `System.nanoTime()` could wrap around
      return end - System.nanoTime() > 0;
    }
  }

  /** Invokes {@code toJoin.}{@link Thread#join() join()} uninterruptibly. */
  @J2ktIncompatible
  @GwtIncompatible // concurrency
  public static void joinUninterruptibly(Thread toJoin) {
    boolean interrupted = false;
    try {

  }

  @SuppressWarnings("ThreadPriorityCheck") // TODO: b/175898629 - Consider onSpinWait.
  static void awaitWaiting(Thread t) {
    while (true) {
      Thread.State state = t.getState();
      switch (state) {
        case RUNNABLE:
        case BLOCKED:
          Thread.yield();
          break;
        case WAITING:
          return;
        default:

        final int threadCount = 10;
        Thread[] threads = new Thread[threadCount];

        // Create threads that access password
        for (int i = 0; i < threadCount; i++) {
            final int index = i;
            threads[i] = new Thread(() -> {
                try {
                    Thread.sleep((long) (Math.random() * 10));
                    if (index == threadCount - 1) {

    call: Call,
    delay: Long,
  ): Thread {
    val thread =
      object : Thread("canceler") {
        override fun run() {
          try {
            sleep(delay)
          } catch (e: InterruptedException) {
            throw AssertionError()
          }
          call.cancel()
        }
      }
    thread.start()
    return thread
  }

    assertFalse(future.isDone());
    assertFalse(future.isCancelled());

    CountDownLatch successLatch = new CountDownLatch(1);

    // Run cancellation in a separate thread as an extra thread-safety test.
    new Thread(
            () -> {
              assertThrows(CancellationException.class, future::get);
              successLatch.countDown();
            })
        .start();

    }

    // Test thread safety
    @Test
    public void test_threadSafety() {
        // Test that the provider returns the same instances in multi-threaded environment
        final int threadCount = 10;
        final Thread[] threads = new Thread[threadCount];
        final InvertibleCryptographer[] invertibles = new InvertibleCryptographer[threadCount];