### Concurrence et Burgers

L'idée de code **asynchrone** décrite ci-dessus est parfois aussi appelée **"concurrence"**. Ce qui est différent du **"parallélisme"**.

La **concurrence** et le **parallélisme** sont tous deux liés à l'idée de "différentes choses arrivant plus ou moins au même moment".

Mais les détails entre la **concurrence** et le **parallélisme** diffèrent sur de nombreux points.

En ajoutant `standard`, Uvicorn va installer et utiliser quelques dépendances supplémentaires recommandées.

Cela inclut `uvloop`, le remplaçant performant de `asyncio`, qui fournit le gros gain de performance en matière de concurrence.

///

////

//// tab | Hypercorn

* <a href="https://github.com/pgjones/hypercorn" class="external-link" target="_blank">Hypercorn</a>, un serveur ASGI également compatible avec HTTP/2.

```Python hl_lines="7"
{!../../docs_src/first_steps/tutorial003.py!}
```

/// note

Si vous ne connaissez pas la différence, allez voir la section [Concurrence : *"Vous êtes pressés ?"*](../async.md#vous-etes-presses){.internal-link target=_blank}.

///

### Étape 5 : retourner le contenu

```Python hl_lines="8"
{!../../docs_src/first_steps/tutorial001.py!}
```

from typing import AsyncGenerator, ContextManager, TypeVar

import anyio
from anyio import CapacityLimiter
from starlette.concurrency import iterate_in_threadpool as iterate_in_threadpool  # noqa
from starlette.concurrency import run_in_threadpool as run_in_threadpool  # noqa
from starlette.concurrency import (  # noqa
    run_until_first_complete as run_until_first_complete,
)

_T = TypeVar("_T")


@asynccontextmanager

### Concurrent Burgers

You go with your crush to get fast food, you stand in line while the cashier takes the orders from the people in front of you. 😍

<img src="/img/async/concurrent-burgers/concurrent-burgers-01.png" class="illustration">

Then it's your turn, you place your order of 2 very fancy burgers for your crush and you. 🍔🍔

### Concurrencia y Hamburguesas

El concepto de código **asíncrono** descrito anteriormente a veces también se llama **"concurrencia"**. Es diferente del **"paralelismo"**.

**Concurrencia** y **paralelismo** ambos se relacionan con "cosas diferentes que suceden más o menos al mismo tiempo".

Pero los detalles entre *concurrencia* y *paralelismo* son bastante diferentes.

import java.time.Duration;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.CancellationException;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Future;
import java.util.concurrent.Semaphore;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;

import static java.util.concurrent.TimeUnit.MILLISECONDS;
import static java.util.concurrent.TimeUnit.NANOSECONDS;
import static java.util.concurrent.TimeUnit.SECONDS;

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import java.time.Duration;
import java.util.concurrent.Callable;
import java.util.concurrent.CountDownLatch;

import java.time.Duration;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.CancellationException;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Future;
import java.util.concurrent.Semaphore;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;

			// the concurrency make sure we choose only the "start"
			// concurrency to be equal to the lowest number of
			// local disks per server.
			for _, localDiskCount := range globalEndpoints.NLocalDisksPathsPerPool() {
				if localDiskCount < concurrency {
					concurrency = localDiskCount
				}
			}

			// Any concurrency less than '4' just stick to '4' concurrent
			// operations for now to begin with.