/**
   * Schedules [task] for execution in [delayNanos]. A task may only have one future execution
   * scheduled. If the task is already in the queue, the earliest execution time is used.
   *
   * The target execution time is implemented on a best-effort basis. If another task in this queue
   * is running when that time is reached, that task is allowed to complete before this task is

        InternalEntry<Object, Object, ?> entry = segment.getEntry(keyOne, hashOne);

        @SuppressWarnings("unchecked")
        Reference<Object> reference = (Reference<Object>) entry;
        reference.enqueue();

        map.put(keyTwo, valueTwo);
        assertFalse(map.containsKey(keyOne));
        assertFalse(map.containsValue(valueOne));
        assertNull(map.get(keyOne));
        assertEquals(1, map.size());

        InternalEntry<Object, Object, ?> entry = segment.getEntry(keyOne, hashOne);

        @SuppressWarnings("unchecked")
        Reference<Object> reference = (Reference<Object>) entry;
        reference.enqueue();

        map.put(keyTwo, valueTwo);
        assertFalse(map.containsKey(keyOne));
        assertFalse(map.containsValue(valueOne));
        assertNull(map.get(keyOne));
        assertEquals(1, map.size());

// "fifo_queue_dequeue_<tensor_id>", to be executed by this API call.

// Caller must call TF_DeleteTensor() over the returned tensor. If the queue is
// empty, this call is blocked.
//
// Tensors are enqueued via the corresponding TF enqueue op.
// TODO(hongm): Add support for `timeout_ms`.
TF_CAPI_EXPORT extern TF_Tensor* TF_DequeueNamedTensor(TF_Session* session,

  @BeforeEach
  fun setup(server: MockWebServer) {
    this.server = server

    server.enqueue(MockResponse())

    client =
      clientTestRule.newClientBuilder()
        .sslSocketFactory(
          handshakeCertificates.sslSocketFactory(),
          handshakeCertificates.trustManager,
        )

    serverSocket.close()

    // Await shutdown.
    for (queue in taskRunner.activeQueues()) {
      if (!queue.idleLatch().await(5, TimeUnit.SECONDS)) {
        throw IOException("Gave up waiting for queue to shut down")
      }
    }
    taskRunnerBackend.shutdown()
  }

  private fun serveConnection(raw: Socket) {
    taskRunner.newQueue().execute("MockWebServer ${raw.remoteSocketAddress}", cancelable = false) {

    .heldCertificate(serverCertificate)
    .build();
MockWebServer server = new MockWebServer();
server.useHttps(serverCertificates.sslSocketFactory(), false);
server.requestClientAuth();
server.enqueue(new MockResponse());

// Create a client certificate and a client that uses it.
HeldCertificate clientCertificate = new HeldCertificate.Builder()
    .commonName("ianmalcolm")
    .signedBy(rootCertificate)

#### Do-stuff-later pool

Sometimes there's an action required like calling the application layer or responding to a ping, and the thread discovering the action is not the thread that should do the work. We enqueue a runnable on this executor and it gets handled by one of the executor's threads.

### Locks

We have 3 different things that we synchronize on.

#### Http2Connection

    responses: MutableList<InetAddress>,
    failures: MutableList<Exception>,
  ) {
    val latch = CountDownLatch(networkRequests.size)

    for (call in networkRequests) {
      call.enqueue(
        object : Callback {
          override fun onFailure(
            call: Call,
            e: IOException,
          ) {
            synchronized(failures) {
              failures.add(e)

              }
            },
            directExecutor()));
    thingToCancel[0] = serializer.submit(Callables.returning(null), directExecutor());
    results.add(thingToCancel[0]);
    // Enqueue more than enough tasks to force reentrancy.
    for (int i = 0; i < 5; i++) {
      results.add(serializer.submit(Callables.returning(null), directExecutor()));
    }

    manualExecutorTask[0].run();