sendRequest(methodName, arguments);
    assertEquals(expected, getResponse(methodName).getThrowable().getClass());
  }

  /**
   * Causes this thread to call the named method, and asserts that this thread becomes blocked on
   * the lock-like object. The lock-like object must have a method equivalent to {@link
   * java.util.concurrent.locks.ReentrantLock#hasQueuedThread(Thread)}.
   */

    long timeout = SECONDS.toNanos(60);

    Supplier<Boolean> supplier =
        new Supplier<Boolean>() {
          boolean isWaiting(Thread thread) {
            switch (thread.getState()) {
              case BLOCKED:
              case WAITING:
              case TIMED_WAITING:
                return true;
              default:
                return false;
            }
          }

                // Expected
            }
        }

        assertEquals(State.OPEN, circuitBreaker.getState(), "Circuit should be OPEN");

        // Try to execute - should be blocked with CIFSException
        CIFSException exception = assertThrows(CIFSException.class, () -> {
            circuitBreaker.executeWithCircuitBreaker(() -> "should not execute");

    /**
     * Circuit breaker states
     */
    public enum State {
        CLOSED, // Normal operation
        OPEN, // Failing, requests blocked
        HALF_OPEN // Testing recovery
    }

    private final String name;
    private final AtomicReference<State> state = new AtomicReference<>(State.CLOSED);

  @SuppressWarnings("ThreadPriorityCheck") // TODO: b/175898629 - Consider onSpinWait.
  void awaitTimedWaiting(Thread thread) {
    while (true) {
      switch (thread.getState()) {
        case BLOCKED:
        case NEW:
        case RUNNABLE:
        case WAITING:
          Thread.yield();
          break;
        case TIMED_WAITING:
          return;
        case TERMINATED:

    sendRequest(methodName, arguments);
    assertEquals(expected, getResponse(methodName).getThrowable().getClass());
  }

  /**
   * Causes this thread to call the named method, and asserts that this thread becomes blocked on
   * the lock-like object. The lock-like object must have a method equivalent to {@link
   * java.util.concurrent.locks.ReentrantLock#hasQueuedThread(Thread)}.
   */

    // This should wake up waiter1 and cause the waiter1 node to be removed.
    waiter1.interrupt();

    waiter1.join();
    waiter2.awaitWaiting(); // should still be blocked

    LockSupport.unpark(waiter2); // spurious wakeup
    waiter2.awaitWaiting(); // should eventually re-park

    future.set(null);
    waiter2.join();
  }

  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:
          throw new AssertionError("unexpected state: " + state);
      }
    }
  }

    // This should wake up waiter1 and cause the waiter1 node to be removed.
    waiter1.interrupt();

    waiter1.join();
    waiter2.awaitWaiting(); // should still be blocked

    LockSupport.unpark(waiter2); // spurious wakeup
    waiter2.awaitWaiting(); // should eventually re-park

    future.set(null);
    waiter2.join();
  }

  internal fun removeStream(streamId: Int): Http2Stream? {
    withLock {
      val stream = streams.remove(streamId)

      // The removed stream may be blocked on a connection-wide window update.
      notifyAll()

      return stream
    }
  }

  internal fun updateConnectionFlowControl(read: Long) {
    withLock {
      readBytes.update(total = read)