{* ../../docs_src/background_tasks/tutorial001_py310.py hl[14] *}

`.add_task()` 接收以下参数：

* 在后台运行的任务函数(`write_notification`)。
* 应按顺序传递给任务函数的任意参数序列(`email`)。
* 应传递给任务函数的任意关键字参数(`message="some notification"`)。

## 依赖注入 { #dependency-injection }

使用 `BackgroundTasks` 也适用于依赖注入系统，你可以在多个级别声明 `BackgroundTasks` 类型的参数：在 *路径操作函数* 里，在依赖中(可依赖)，在子依赖中，等等。

**FastAPI** 知道在每种情况下该做什么以及如何复用同一对象，因此所有后台任务被合并在一起并且随后在后台运行：

    export TFCI_INSTALLER_WHL_PROJECT_NAME="$TFCI_INSTALLER_WHL_NIGHTLY_PROJECT_NAME"
  fi
  export project_name="$TFCI_INSTALLER_WHL_PROJECT_NAME"
fi

# Mac builds have some specific setup needs. See setup_macos.sh for details
if [[ "${OSTYPE}" =~ darwin* ]]; then
  source ./ci/official/utilities/setup_macos.sh
fi

# Create and expand to the full path of TFCI_OUTPUT_DIR

        // Verify response contains meaningful data
        assertNotNull(res, "Stats response should not be null");
        assertTrue(res.size() > 0, "Stats should contain at least some data");

        // Check for common stats fields (these may need to be adjusted based on actual implementation)
        // Examples of fields that might be present:
        // - Document count
        // - Index size

    interrupter.start();
    // this will happen once the interrupt has been set which means that
    // 1. the runner has been woken up
    // 2. the interrupter is stuck in the call the Thread.interrupt()

    // after some period of time the runner thread should become blocked on the task because it is
    // waiting for the slow interrupting thread to complete Thread.interrupt
    awaitBlockedOnInstanceOf(runner, InterruptibleTask.Blocker.class);

    interrupter.start();
    // this will happen once the interrupt has been set which means that
    // 1. the runner has been woken up
    // 2. the interrupter is stuck in the call the Thread.interrupt()

    // after some period of time the runner thread should become blocked on the task because it is
    // waiting for the slow interrupting thread to complete Thread.interrupt
    awaitBlockedOnInstanceOf(runner, InterruptibleTask.Blocker.class);

            final Set<File> failedToDelete = deleteHelper.deleteFiles(filesToDelete);

            if (failedToDelete.isEmpty() == false) {
                throw new GradleException(
                    "Failed to delete some files:\n\n"
                        + failedToDelete.stream().map(file -> "\t" + rootDir.relativize(file.toPath())).collect(Collectors.joining("\n"))
                        + "\n"
                );
            }

You could also use `from starlette.middleware.cors import CORSMiddleware`.

**FastAPI** provides several middlewares in `fastapi.middleware` just as a convenience for you, the developer. But most of the available middlewares come directly from Starlette.

Запустіть тести за допомогою:

<div class="termy">

```console
$ pytest

================ test session starts ================
platform linux -- Python 3.6.9, pytest-5.3.5, py-1.8.1, pluggy-0.13.1
rootdir: /home/user/code/superawesome-cli/app
plugins: forked-1.1.3, xdist-1.31.0, cov-2.8.1
collected 6 items

---> 100%

test_main.py <span style="color: green; white-space: pre;">......                            [100%]</span>

	lockMaintenanceInterval = 1 * time.Minute

	// Lock validity duration
	lockValidityDuration = 1 * time.Minute
)

// lockMaintenance loops over all locks and discards locks
// that have not been refreshed for some time.
func lockMaintenance(ctx context.Context) {
	if !globalIsDistErasure {
		return
	}

	// Initialize a new ticker with 1 minute between each ticks.
	lkTimer := time.NewTimer(lockMaintenanceInterval)

	m.init.Do(m.initManager)
	m.mu.Lock()
	b, ok := m.buckets[bucket]
	if !ok {
		m.mu.Unlock()
		return
	}
	delete(m.buckets, bucket)
	m.mu.Unlock()

	// Since deletes may take some time we try to do it without
	// holding lock to m all the time.
	b.mu.Lock()
	defer b.mu.Unlock()
	for k, v := range b.caches {
		if time.Since(v.lastUpdate) > metacacheMaxRunningAge {