* that every {@code Runnable} that is {@linkplain #add added} will be executed after {@link
 * #execute()} is called. Any {@code Runnable} added after the call to {@code execute} is still
 * guaranteed to execute. There is no guarantee, however, that listeners will be executed in the
 * order that they are added.
 *

```

////

These dependencies will be executed/solved the same way as normal dependencies. But their value (if they return any) won't be passed to your *path operation function*.

/// tip

Some editors check for unused function parameters, and show them as errors.

Using these `dependencies` in the *path operation decorator* you can make sure they are executed while avoiding editor/tooling errors.

    boolean executed = false;

    public void add(Runnable runnable, Executor executor) {
      Preconditions.checkNotNull(runnable, "Runnable was null.");
      Preconditions.checkNotNull(executor, "Executor was null.");

      boolean executeImmediate = false;

      synchronized (runnables) {
        if (!executed) {

   *
   * The [dispatcher][OkHttpClient.dispatcher] defines when the request will run: usually
   * immediately unless there are several other requests currently being executed.
   *
   * This client will later call back `responseCallback` with either an HTTP response or a failure
   * exception.
   *
   * @throws IllegalStateException when the call has already been executed.
   */

You can define logic (code) that should be executed before the application **starts up**. This means that this code will be executed **once**, **before** the application **starts receiving requests**.

The same way, you can define logic (code) that should be executed when the application is **shutting down**. In this case, this code will be executed **once**, **after** having handled possibly **many requests**.

import okhttp3.internal.connection.RealCall
import okhttp3.internal.connection.RealCall.AsyncCall
import okhttp3.internal.okHttpName
import okhttp3.internal.threadFactory

/**
 * Policy on when async requests are executed.
 *
 * Each dispatcher uses an [ExecutorService] to run calls internally. If you supply your own
 * executor, it should be able to run [the configured maximum][maxRequests] number of calls
 * concurrently.
 */

```Python hl_lines="1  15"
{!../../docs_src/debugging/tutorial001.py!}
```

### About `__name__ == "__main__"`

The main purpose of the `__name__ == "__main__"` is to have some code that is executed when your file is called with:

<div class="termy">

```console
$ python myapp.py
```

</div>

but is not called when another file imports it, like in:

```Python
from myapp import app
```

 * limitations under the License.
 */
package okhttp3.internal.concurrent

/**
 * A unit of work that can be executed one or more times.
 *
 * Recurrence
 * ----------
 *
 * Tasks control their recurrence schedule. The [runOnce] function returns -1L to signify that the
 * task should not be executed again. Otherwise it returns a delay until the next execution.
 *

        }
    }

    protected static class ProcessDestroyer extends TimerTask {

        private final Process p;

        private final InputStreamThread ist;

        private final AtomicBoolean executed = new AtomicBoolean(false);

        private final long timeout;

        public ProcessDestroyer(final Process p, final InputStreamThread ist, final long timeout) {
            this.p = p;

  override fun execute(): Response {
    check(executed.compareAndSet(false, true)) { "Already Executed" }

    timeout.enter()
    callStart()
    try {
      client.dispatcher.executed(this)
      return getResponseWithInterceptorChain()
    } finally {
      client.dispatcher.finished(this)
    }
  }

  override fun enqueue(responseCallback: Callback) {
    check(executed.compareAndSet(false, true)) { "Already Executed" }