# Concurrencia y async / await

Detalles sobre la sintaxis `async def` para *path operation functions* y algunos antecedentes sobre el código asíncrono, la concurrencia y el paralelismo.

## ¿Con prisa?

<abbr title="too long; didn't read"><strong>TL;DR:</strong></abbr>

Si estás usando paquetes de terceros que te dicen que los llames con `await`, como:

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

      if (result == CancellationException.class) {
        assertTrue(future.isCancelled());
        if (future.wasInterrupted()) {
          // We were cancelled, it is possible that setFuture could have succeeded too.
          assertThat(numSuccessfulSetCalls.get()).isIn(Range.closed(1, 2));
        } else {
          assertThat(numSuccessfulSetCalls.get()).isEqualTo(1);
        }
      } else {

    return asCharSource(file, charset).readLines(callback);
  }

  /**
   * Process the bytes of a file.
   *
   * <p>(If this seems too complicated, maybe you're looking for {@link #toByteArray}.)
   *
   * @param file the file to read
   * @param processor the object to which the bytes of the file are passed.
   * @return the result of the byte processor

   *
   * @throws IllegalArgumentException if {@code bytes} has fewer than 8 elements
   */
  public static long fromByteArray(byte[] bytes) {
    checkArgument(bytes.length >= BYTES, "array too small: %s < %s", bytes.length, BYTES);
    return fromBytes(
        bytes[0], bytes[1], bytes[2], bytes[3], bytes[4], bytes[5], bytes[6], bytes[7]);
  }

  /**

# 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()
```

   *   flooding. Callers can confirm this by null-checking delegateOrNull().
   *
   * In an ideal world, we would document why we know those things are true every time we call these
   * methods. But that is a bit too painful....
   */

  private Object requireTable() {
    return requireNonNull(table);
  }

  private int[] requireEntries() {
    return requireNonNull(entries);
  }

    return asCharSource(file, charset).readLines(callback);
  }

  /**
   * Process the bytes of a file.
   *
   * <p>(If this seems too complicated, maybe you're looking for {@link #toByteArray}.)
   *
   * @param file the file to read
   * @param processor the object to which the bytes of the file are passed.
   * @return the result of the byte processor

	res.After.Drives = make([]madmin.HealDriveInfo, len(beforeDrives))
	res.Before.Drives = make([]madmin.HealDriveInfo, len(beforeDrives))
	// Copy "after" drive state too from before.
	for k, v := range beforeDrives {
		res.Before.Drives[k] = v
		res.After.Drives[k] = v
	}

	if countErrs(sErrs, errUnformattedDisk) == 0 {
		return res, errNoHealRequired
	}

# 並行與 async / await

有關*路徑操作函式*的 `async def` 語法的細節與非同步 (asynchronous) 程式碼、並行 (concurrency) 與平行 (parallelism) 的一些背景知識。

## 趕時間嗎?

<abbr title="too long; didn't read（文長慎入）"><strong>TL;DR:</strong></abbr>

如果你正在使用要求你以 `await` 語法呼叫的第三方函式庫，例如：

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

然後，使用 `async def` 宣告你的*路徑操作函式*：


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

    assertEquals(ImmutableSet.of(3, 2, 1), i.next());
    assertFalse(i.hasNext());
    assertThrows(NoSuchElementException.class, () -> i.next());
  }

  @GwtIncompatible // too slow for GWT
  public void testPowerSetIteration_iteratorTester() {
    ImmutableSet<Integer> elements = ImmutableSet.of(1, 2);

    Set<Set<Integer>> expected = new LinkedHashSet<>();