public class ChannelFailover {
    private final ChannelManager manager;
    private final ExecutorService executor;
    private final Map<String, FailoverState> failoverStates;
    
    public ChannelFailover(ChannelManager manager) {
        this.manager = manager;
        this.executor = Executors.newCachedThreadPool();
        this.failoverStates = new ConcurrentHashMap<>();
    }
    

  /**
   * Returns a snapshot of tasks currently scheduled for execution. Does not include the
   * currently-executing task unless it is also scheduled for future execution.
   */
  val scheduledTasks: List<Task>
    get() = taskRunner.withLock { futureTasks.toList() }

  /**
   * Schedules [task] for execution in [delayNanos]. A task may only have one future execution

        if (cleanupTask != null) {
            cleanupTask.cancel(false);
        }

        // Force cleanup of all resources
        int cleaned = forceCleanup();

        // Shutdown executor
        cleanupExecutor.shutdown();
        try {
            if (!cleanupExecutor.awaitTermination(5, TimeUnit.SECONDS)) {
                cleanupExecutor.shutdownNow();
            }

=== ":material-language-kotlin: Kotlin"
    ```kotlin
      private val executor = Executors.newScheduledThreadPool(1)
      private val client = OkHttpClient()

      fun run() {
        val request = Request.Builder()

    assertTrue(ArbitraryInstances.get(ConcurrentMap.class).isEmpty());
    assertTrue(ArbitraryInstances.get(ConcurrentNavigableMap.class).isEmpty());
    ArbitraryInstances.get(Executor.class).execute(ArbitraryInstances.get(Runnable.class));
    assertNotNull(ArbitraryInstances.get(ThreadFactory.class));
    assertFreshInstanceReturned(
        BlockingQueue.class,
        BlockingDeque.class,

    assertTrue(ArbitraryInstances.get(ConcurrentMap.class).isEmpty());
    assertTrue(ArbitraryInstances.get(ConcurrentNavigableMap.class).isEmpty());
    ArbitraryInstances.get(Executor.class).execute(ArbitraryInstances.get(Runnable.class));
    assertNotNull(ArbitraryInstances.get(ThreadFactory.class));
    assertFreshInstanceReturned(
        BlockingQueue.class,
        BlockingDeque.class,

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

        thumbnailQueueBhv.batchInsert(list);
    }

    /**
     * Generates thumbnails using the provided executor service.
     *
     * @param executorService the executor service for parallel processing
     * @param cleanup whether to run in cleanup mode
     * @return the number of tasks processed
     */

    }

    // Test execute method with successful execution
    public void test_execute_success() {
        pythonJob.filename("test.py");
        pythonJob.args("arg1", "arg2");

        testProcessHelper.exitValue = 0;
        testProcessHelper.processOutput = "Python script executed successfully";

        String result = pythonJob.execute();

        assertNotNull(result);

     */
    requireNonNull(futures);

    // Corner case: List is empty.
    if (futures.isEmpty()) {
      handleAllCompleted();
      return;
    }

    // NOTE: If we ever want to use a custom executor here, have a look at CombinedFuture as we'll
    // need to handle RejectedExecutionException

    if (allMustSucceed) {
      // We need fail fast, so we have to keep track of which future failed so we can propagate