trash:   make(map[string]metacache),
}

type metacacheManager struct {
	mu      sync.RWMutex
	init    sync.Once
	buckets map[string]*bucketMetacache
	trash   map[string]metacache // Recently deleted lists.
}

const metacacheMaxEntries = 5000

// initManager will start async saving the cache.
func (m *metacacheManager) initManager() {
	// Add a transient bucket.

**FastAPI** 🔜 ✍ 🎚 🆎 `BackgroundTasks` 👆 & 🚶‍♀️ ⚫️ 👈 🔢.

## ✍ 📋 🔢

✍ 🔢 🏃 🖥 📋.

⚫️ 🐩 🔢 👈 💪 📨 🔢.

⚫️ 💪 `async def` ⚖️ 😐 `def` 🔢, **FastAPI** 🔜 💭 ❔ 🍵 ⚫️ ☑.

👉 💼, 📋 🔢 🔜 ✍ 📁 (⚖ 📨 📧).

& ✍ 🛠️ 🚫 ⚙️ `async` & `await`, 👥 🔬 🔢 ⏮️ 😐 `def`:

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

## 🚮 🖥 📋

En este caso, es una función `async`.

---

También podrías definirla como una función normal en lugar de `async def`:

{* ../../docs_src/first_steps/tutorial003.py hl[7] *}

/// note | Nota

Si no sabes la diferencia, revisa la sección [Async: *"¿Tienes prisa?"*](../async.md#in-a-hurry){.internal-link target=_blank}.

///

import java.net.Inet6Address
import java.net.InetAddress
import okhttp3.internal.interleave

/**
 * Implementation of HappyEyeballs Sorting Addresses.
 *
 * The current implementation does not address any of:
 *  - Async DNS split by IP class
 *  - Stateful handling of connectivity results
 *  - The prioritisation of addresses
 *
 * https://datatracker.ietf.org/doc/html/rfc8305#section-4
 */

<details markdown="1">
<summary>또는 <code>async def</code> 사용하기...</summary>

여러분의 코드가 `async` / `await`을 사용한다면, `async def`를 사용하십시오.

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

from fastapi import FastAPI

app = FastAPI()


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


@app.get("/items/{item_id}")
async def read_item(item_id: int, q: Union[str, None] = None):

```

<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"}


@app.get("/items/{item_id}")
async def read_item(item_id: int, q: Union[str, None] = None):

<summary>Of maak gebruik van <code>async def</code>...</summary>

Als je code gebruik maakt van `async` / `await`, gebruik dan `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"}


@app.get("/items/{item_id}")

<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"}


@app.get("/items/{item_id}")
async def read_item(item_id: int, q: Union[str, None] = None):

It is just a standard function that can receive parameters.

It can be an `async def` or normal `def` function, **FastAPI** will know how to handle it correctly.

In this case, the task function will write to a file (simulating sending an email).

And as the write operation doesn't use `async` and `await`, we define the function with normal `def`:

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

É apenas uma função padrão que pode receber parâmetros.

Pode ser uma função `async def` ou `def` normal, o **FastAPI** saberá como lidar com isso corretamente.

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] *}