/// tip | Dica

{* ../../docs_src/background_tasks/tutorial001_py39.py hl[1,13] *}

**FastAPI** erstellt für Sie das Objekt vom Typ `BackgroundTasks` und übergibt es als diesen Parameter.

## Eine Taskfunktion erstellen { #create-a-task-function }

Erstellen Sie eine Funktion, die als Hintergrundtask ausgeführt werden soll.

Es handelt sich schlicht um eine Standard-Funktion, die Parameter empfangen kann.

 * to the build service.
 */
interface TestFilesCleanupBuildServiceRootExtension {
    val projectStates: MapProperty<String, TestFilesCleanupProjectState>

    /**
     * Key is the path of a task, value is the possible report dirs it generates.
     */
    val taskPathToReports: MapProperty<String, List<File>>

     * Entry point to the execution strategy
     *
     * @param mojos             list of mojos representing a project build
     * @param session           current session
     * @param mojoExecutionRunner mojo execution task which must be invoked by a strategy to actually run it
     * @throws LifecycleExecutionException
     */
    void execute(List<MojoExecution> mojos, MavenSession session, MojoExecutionRunner mojoExecutionRunner)

        return String.format("%s-%d-%d", resource.getClass().getSimpleName(), System.identityHashCode(resource),
                resourceIdCounter.incrementAndGet());
    }

    /**
     * Start the cleanup task
     */
    private void startCleanupTask() {
        if (cleanupTask != null) {
            cleanupTask.cancel(false);
        }

        cleanupTask = cleanupExecutor.scheduleWithFixedDelay(() -> {

{* ../../docs_src/background_tasks/tutorial001_py39.py hl[1,13] *}

O **FastAPI** criará o objeto do tipo `BackgroundTasks` para você e o passará como esse parâmetro.

## Crie uma função de tarefa { #create-a-task-function }

Crie uma função para ser executada como a tarefa em segundo plano.

É apenas uma função padrão que pode receber parâmetros.

## 其他异步函数调用

由于测试函数现在是异步的，因此除了在测试中向 FastAPI 应用程序发送请求之外，您现在还可以调用（和使用 `await` 等待）其他 `async` 异步函数，就和您在代码中的其他任何地方调用它们的方法一样。

/// tip

如果您在测试程序中集成异步函数调用的时候遇到一个 `RuntimeError: Task attached to a different loop` 的报错（例如，使用 <a href="https://stackoverflow.com/questions/41584243/runtimeerror-task-attached-to-a-different-loop" class="external-link" target="_blank">MongoDB 的 MotorClient</a> 时），请记住，只能在异步函数中实例化需要事件循环的对象，例如通过 `'@app.on_event("startup")` 回调函数进行初始化。

/// tip | 팁

테스트에 비동기 함수 호출을 통합할 때 (예: <a href="https://stackoverflow.com/questions/41584243/runtimeerror-task-attached-to-a-different-loop" class="external-link" target="_blank">MongoDB의 MotorClient</a>를 사용할 때) `RuntimeError: Task attached to a different loop` 오류가 발생한다면, 이벤트 루프가 필요한 객체는 반드시 비동기 함수 내에서만 인스턴스화해야 한다는 점을 주의하세요!
예를 들어 `@app.on_event("startup")` 콜백 내에서 인스턴스화하는 것이 좋습니다.

import org.gradle.api.tasks.InputDirectory
import org.gradle.api.tasks.PathSensitive
import org.gradle.api.tasks.PathSensitivity
import org.gradle.api.tasks.TaskAction
import org.gradle.work.DisableCachingByDefault

/**
 * A task used for cleaning up all accepted API changes. The functionality is called whenever the release process initiates "branching".
 */
@DisableCachingByDefault(because = "Not worth caching")

01-01 12:53:32.818 10999 11090 D OkHttp  : [56 ms] callEnd
```

3. Run tests using gradle

```
$ ANDROID_SDK_ROOT=/Users/myusername/Library/Android/sdk ./gradlew :android-test:connectedCheck -PandroidBuild=true
...
> Task :android-test:connectedDebugAndroidTest
...
11:55:40 V/InstrumentationResultParser: Time: 13.271
11:55:40 V/InstrumentationResultParser:
11:55:40 V/InstrumentationResultParser: OK (12 tests)
...