# Concorrência e async / await

Detalhes sobre a sintaxe `async def` para *funções de operação de rota* e alguns conceitos de código assíncrono, concorrência e paralelismo.

## Com pressa?

<abbr title="muito longo; não li"><strong>TL;DR:</strong></abbr>

Se você estiver utilizando bibliotecas de terceiros que dizem para você chamar as funções com `await`, como:

```Python
results = await some_library()
```

results = await some_library()
```
Alors, déclarez vos *fonctions de chemins* avec `async def` comme ceci :

```Python hl_lines="2"
@app.get('/')
async def read_results():
    results = await some_library()
    return results
```

/// note

Vous pouvez uniquement utiliser `await` dans les fonctions créées avec `async def`.

///

---

        for (int i = 0; i < threadCount; i++) {
            executor.submit(new Runnable() {
                @Override
                public void run() {
                    try {
                        startLatch.await();
                        for (int j = 0; j < operationsPerThread; j++) {
                            crawlerContext.incrementAndGetAccessCount();
                        }

          @Override
          protected void finalize() {
            latch.countDown();
          }
        };
    unused = null; // Hint to the JIT that unused is unreachable
    GcFinalization.await(latch);
    assertEquals(0, latch.getCount());
  }

  public void testAwaitDone_future() {
    SettableFuture<@Nullable Void> future = SettableFuture.create();
    Object unused =
        new Object() {

                }
            }, "ProcessCloser-output-" + sessionId).start();

            try {
                latch.await(10, TimeUnit.SECONDS);
            } catch (final InterruptedException e) {
                logger.warn("Interrupted to wait a process.", e);
            }
            try {
                process.destroyForcibly().waitFor(processDestroyTimeout, TimeUnit.SECONDS);

# Nebenläufigkeit und async / await

Details zur `async def`-Syntax für *Pfadoperation-Funktionen* und Hintergrundinformationen zu asynchronem Code, Nebenläufigkeit und Parallelität.

## In Eile?

<abbr title="too long; didn't read – Zu lang; nicht gelesen"><strong>TL;DR:</strong></abbr>

Wenn Sie Bibliotheken von Dritten verwenden, die mit `await` aufgerufen werden müssen, wie zum Beispiel:

```Python
results = await some_library()
```

🚥 👆 ⚙️ 🥉 🥳 🗃 👈 💬 👆 🤙 👫 ⏮️ `await`, 💖:

```Python
results = await some_library()
```

⤴️, 📣 👆 *➡ 🛠️ 🔢* ⏮️ `async def` 💖:

```Python hl_lines="2"
@app.get('/')
async def read_results():
    results = await some_library()
    return results
```

/// note

👆 💪 🕴 ⚙️ `await` 🔘 🔢 ✍ ⏮️ `async def`.

///

---

          t: Throwable,
          response: Response?,
        ) {
          t.printStackTrace(System.out)
          latch.countDown()
        }
      },
    )

    check(latch.await(30, TimeUnit.SECONDS)) { "Timed out waiting for test $number to finish." }
    val endNanos = System.nanoTime()
    val tookMs = TimeUnit.NANOSECONDS.toMillis(endNanos - startNanos.get())
    println("Took ${tookMs}ms")
  }

    assertEquals(3L, countDownLatch.getCount());

    list.execute();

    // Verify that all of the runnables execute in a reasonable amount of time.
    assertTrue(countDownLatch.await(1L, SECONDS));
  }

  public void testExecute_idempotent() {
    AtomicInteger runCalled = new AtomicInteger();
    list.add(
        new Runnable() {
          @Override
          public void run() {

# هم‌زمانی و async / await

جزئیات در مورد سینتکس `async def` برای *توابع عملیات مسیر* و یه کم پیش‌زمینه در مورد کد ناهم‌زمان، هم‌زمانی و موازی‌سازی.

## عجله داری؟

<abbr title="خیلی طولانی بود؛ نخوندم"><strong>TL;DR:</strong></abbr>

اگه از کتابخونه‌های سوم‌شخصی استفاده می‌کنی که بهت می‌گن با `await` صداشون کنی، مثل:

```Python
results = await some_library()
```

اون وقت، *توابع عملیات مسیرت* رو با `async def` تعریف کن، اینجوری: