boolean isRunning();

  /** Returns the lifecycle state of the service. */
  State state();

  /**
   * If the service is {@linkplain State#STARTING starting} or {@linkplain State#RUNNING running},
   * this initiates service shutdown and returns immediately. If the service is {@linkplain
   * State#NEW new}, it is {@linkplain State#TERMINATED terminated} without having been started nor

            /* This guarantees that we leave in a valid state
             */
            if (state != 0 && state != 3 && state != 4) {
                if (LogStream.level >= 1) {
                    log.println("Invalid state: " + state);
                }
                state = 0;
                thread = null;
            }
        }
    }

    /**
     * Disconnects from the remote endpoint.
     *

        } catch (Exception e) {
            state = RdmaConnectionState.ERROR;
            throw new IOException("DiSNI RDMA send failed", e);
        }
    }

    @Override
    public ByteBuffer receive(int timeout) throws IOException {
        if (state != RdmaConnectionState.ESTABLISHED && state != RdmaConnectionState.CONNECTED) {

              + this
              + " to reach a terminal state. "
              + "Current state: "
              + state());
    }
  }

  /** Checks that the current state is equal to the expected state. */
  @GuardedBy("monitor")
  private void checkCurrentState(State expected) {
    State actual = state();
    if (actual != expected) {
      if (actual == FAILED) {

        totalFailures.incrementAndGet();
        lastFailureTime.set(System.currentTimeMillis());

        State current = state.get();

        if (current == State.HALF_OPEN) {
            // Single failure in half-open state reopens the circuit
            if (state.compareAndSet(State.HALF_OPEN, State.OPEN)) {
                stateChangeTime.set(System.currentTimeMillis());
                consecutiveFailures.set(1);

    }

    @Test
    @DisplayName("Test initial state is CLOSED")
    void testInitialState() {
        assertEquals(SimpleCircuitBreaker.State.CLOSED, circuitBreaker.getState());
        assertTrue(circuitBreaker.allowsRequests());
    }

    @Test
    @DisplayName("Test successful calls in CLOSED state")
    void testSuccessfulCalls() throws Exception {

    assertEquals(Service.State.RUNNING, service.state());

    exitRun.countDown(); // the service will exit voluntarily
    executionThread.join();

    assertTrue(service.shutDownCalled);
    assertEquals(Service.State.TERMINATED, service.state());

    service.stopAsync().awaitTerminated(); // no-op
    assertEquals(Service.State.TERMINATED, service.state());
    assertTrue(service.shutDownCalled);
  }

        int state, t, x, i, off;
        byte ch;
        final byte[] type = new byte[128];
        final byte[] buf = new byte[16];
        final byte[] ext = extension.toLowerCase().getBytes("ASCII");

        state = ST_START;
        t = x = i = 0;
        for (off = 0; off < inLen; off++) {
            ch = in[off];
            switch (state) {
            case ST_START:

    void testFailoverStateCreation() {
        ChannelFailover.FailoverState state = new ChannelFailover.FailoverState("test-channel");

        assertEquals("test-channel", state.getChannelId());
        assertEquals(0, state.getRetryCount());
        assertTrue(state.shouldRetry());
        assertTrue(state.getFailureTime() > 0);
        assertTrue(state.getNextRetryTime() > state.getFailureTime());
    }

    @Test

    checkState(state != State.FAILED);
    switch (state) {
      case DONE:
        return false;
      case READY:
        return true;
      default:
    }
    return tryToComputeNext();
  }

  private boolean tryToComputeNext() {
    state = State.FAILED; // temporary pessimism
    next = computeNext();
    if (state != State.DONE) {
      state = State.READY;
      return true;
    }