Nesse caso, a função de tarefa gravará em um arquivo (simulando o envio de um e-mail).

E como a operação de gravação não usa `async` e `await`, definimos a função com `def` normal:

{* ../../docs_src/background_tasks/tutorial001.py hl[6:9] *}

## Adicionar a tarefa em segundo plano

<img src="/img/tutorial/websockets/image05.png">

## Обработка отключений и работа с несколькими клиентами

Если веб-сокет соединение закрыто, то `await websocket.receive_text()` вызовет исключение `WebSocketDisconnect`, которое можно поймать и обработать как в этом примере:

{* ../../docs_src/websockets/tutorial003_py39.py hl[79:81] *}

Чтобы воспроизвести пример:

def read_item(item_id: int, q: Union[str, None] = None):
    return {"item_id": item_id, "q": q}
```

<details markdown="1">
<summary>O usa <code>async def</code>...</summary>

Si tu código usa `async` / `await`, usa `async def`:

```Python hl_lines="9  14"
from typing import Union

from fastapi import FastAPI

app = FastAPI()


@app.get("/")
async def read_root():
    return {"Hello": "World"}

def read_item(item_id: int, q: Union[str, None] = None):
    return {"item_id": item_id, "q": q}
```

<details markdown="1">
<summary>Ou use <code>async def</code>...</summary>

Se seu código utiliza `async` / `await`, use `async def`:

```Python hl_lines="9  14"
from typing import Union

from fastapi import FastAPI

app = FastAPI()


@app.get("/")
async def read_root():
    return {"Hello": "World"}

                }
            });
        }

        // Start all threads
        for (Thread thread : threads) {
            thread.start();
        }

        // Wait for all threads to complete
        for (Thread thread : threads) {
            thread.join(5000); // 5 second timeout
        }

        // Verify no errors occurred during concurrent execution

        var first = true

        override fun createSocket(): Socket {
          if (first) {
            first = false
            firstConnectLatch.await()
          }
          return super.createSocket()
        }
      }

    client =
      client
        .newBuilder()
        .protocols(listOf(Protocol.H2_PRIOR_KNOWLEDGE))

백그라운드 작업으로 실행할 함수를 정의합니다.

이것은 단순히 매개변수를 받을 수 있는 표준 함수일 뿐입니다.

**FastAPI**는 이것이 `async def` 함수이든, 일반 `def` 함수이든 내부적으로 이를 올바르게 처리합니다.

이 경우, 아래 작업은 파일에 쓰는 함수입니다. (이메일 보내기 시물레이션)

그리고 이 작업은 `async`와 `await`를 사용하지 않으므로 일반 `def` 함수로 선언합니다.

{* ../../docs_src/background_tasks/tutorial001.py hl[6:9] *}

## 백그라운드 작업 추가

_경로 작동 함수_ 내에서 작업 함수를 `.add_task()` 함수 통해 _백그라운드 작업_ 개체에 전달합니다.

    return {"item_id": item_id, "q": q}
```

<details markdown="1">
<summary>Atau gunakan <code>async def</code>...</summary>

Jika kode anda menggunakan `async` / `await`, gunakan `async def`:

```Python hl_lines="9  14"
from typing import Union

from fastapi import FastAPI

app = FastAPI()


@app.get("/")
async def read_root():

def read_item(item_id: int, q: Union[str, None] = None):
    return {"item_id": item_id, "q": q}
```

<details markdown="1">
<summary>Və ya <code>async def</code>...</summary>

Əgər kodunuzda `async` və ya `await` vardırsa `async def` istifadə edə bilərik:

```Python hl_lines="9  14"
from typing import Union

from fastapi import FastAPI

app = FastAPI()


@app.get("/")
async def read_root():

    }

    val startedTask = startNextTask()
    val otherTasksStarted = startedTask != yieldCompleteTask

    try {
      while (currentTask != self) {
        taskRunner.wait()
      }
    } finally {
      serialTaskQueue.remove(yieldCompleteTask)
    }

    // If we're yielding until we're exhausted and a task run, keep going until a task doesn't run.