if [[ "$TFCI_DOCKER_PULL_ENABLE" == 1 ]]; then
  # Simple retry logic for docker-pull errors. Sleeps if a pull fails.
  # Pulling an already-pulled container image will finish instantly, so
  # repeating the command costs nothing.
  docker pull "$TFCI_DOCKER_IMAGE" || sleep 15
  docker pull "$TFCI_DOCKER_IMAGE" || sleep 30
  docker pull "$TFCI_DOCKER_IMAGE" || sleep 60
  docker pull "$TFCI_DOCKER_IMAGE"
fi 

                }
            }
            currentProcess = null;

        }
    }

    /**
     * Monitor thread that handles process timeout and termination.
     * This thread sleeps for the specified timeout duration and terminates the process if it hasn't finished.
     */
    protected static class MonitorThread extends Thread {
        /** The process to monitor. */

	t := time.Now()
	return func() {
		doneAt := time.Now()
		d.Sleep(ctx, doneAt.Sub(t))
	}
}

// Sleep sleeps the specified time multiplied by the sleep factor.
// If the factor is updated the sleep will be done again with the new factor.
func (d *dynamicSleeper) Sleep(ctx context.Context, base time.Duration) {
	for {
		// Grab current values
		d.mu.RLock()

		rb.Reset()
		done := make(chan struct{})
		go func() {
			defer close(done)
			time.Sleep(10 * time.Millisecond)
			fn()
		}()
		rb.CloseWithError(errors.New("test error"))
		<-done

		rb.Reset()
		done = make(chan struct{})
		go func() {
			defer close(done)
			fn()
		}()
		time.Sleep(10 * time.Millisecond)
		rb.CloseWithError(errors.New("test error"))
		<-done
	}

      afe.initCause(t);
      throw afe;
    }
  }

  /**
   * Delays, via Thread.sleep, for the given millisecond delay, but if the sleep is shorter than
   * specified, may re-sleep or yield until time elapses.
   */
  @SuppressWarnings("ThreadPriorityCheck") // TODO: b/175898629 - Consider onSpinWait?

	return len(s) >= len(prefix) && (s[0:len(prefix)] == prefix || strings.EqualFold(s[0:len(prefix)], prefix))
}

func ptr[T any](a T) *T {
	return &a
}

// sleepContext sleeps for d duration or until ctx is done.
func sleepContext(ctx context.Context, d time.Duration) error {
	select {
	case <-ctx.Done():
		return ctx.Err()
	case <-time.After(d):
	}
	return nil
}

# First Steps { #first-steps }

The simplest FastAPI file could look like this:

{* ../../docs_src/first_steps/tutorial001_py39.py *}

Copy that to a file `main.py`.

Run the live server:

<div class="termy">

```console
$ <font color="#4E9A06">fastapi</font> dev <u style="text-decoration-style:solid">main.py</u>

  <span style="background-color:#009485"><font color="#D3D7CF"> FastAPI </font></span>  Starting development server 🚀

# Security - First Steps { #security-first-steps }

Let's imagine that you have your **backend** API in some domain.

And you have a **frontend** in another domain or in a different path of the same domain (or in a mobile application).

And you want to have a way for the frontend to authenticate with the backend, using a **username** and **password**.

We can use **OAuth2** to build that with **FastAPI**.

# Безопасность — первые шаги { #security-first-steps }

Представим, что у вас есть **бэкенд** API на некотором домене.

И у вас есть **фронтенд** на другом домене или на другом пути того же домена (или в мобильном приложении).

И вы хотите, чтобы фронтенд мог аутентифицироваться на бэкенде, используя **имя пользователя** и **пароль**.

Мы можем использовать **OAuth2**, чтобы построить это с **FastAPI**.

# Sicherheit – Erste Schritte { #security-first-steps }

Stellen wir uns vor, dass Sie Ihre **Backend**-API auf einer Domain haben.

Und Sie haben ein **Frontend** auf einer anderen Domain oder in einem anderen Pfad derselben Domain (oder in einer Mobile-Anwendung).

Und Sie möchten eine Möglichkeit haben, dass sich das Frontend mithilfe eines **Benutzernamens** und eines **Passworts** beim Backend authentisieren kann.