fn := z.decommissionCancelers[idx]
	if fn == nil {
		// canceling a decommission before it started return an error.
		return errDecommissionNotStarted
	}

	defer fn() // cancel any active thread.

	if z.poolMeta.DecommissionCancel(idx) {
		if err = z.poolMeta.save(ctx, z.serverPools); err != nil {
			return err
		}
		globalNotificationSys.ReloadPoolMeta(ctx)
	}

	return nil
}

   * @param executor the executor in which the listeners callback methods will be run. For fast,
   *     lightweight listeners that would be safe to execute in any thread, consider {@link
   *     MoreExecutors#directExecutor}.
   * @since 13.0
   */
  void addListener(Listener listener, Executor executor);

  /**
   * The lifecycle states of a service.
   *

```
hive.blobstore.use.blobstore.as.scratchdir=true
hive.exec.input.listing.max.threads=50
hive.load.dynamic.partitions.thread=25
hive.metastore.fshandler.threads=50
hive.mv.files.threads=40
mapreduce.input.fileinputformat.list-status.num-threads=50
```

 *   <li><b>pure function:</b> the value produced must depend only on the input bytes, in the order
 *       they appear. Input data is never modified. {@link HashFunction} instances should always be
 *       stateless, and therefore thread-safe.
 *   <li><b>collision-averse:</b> while it can't be helped that a hash function will sometimes
 *       produce the same hash code for distinct inputs (a "collision"), every hash function strives

 *   <li><b>pure function:</b> the value produced must depend only on the input bytes, in the order
 *       they appear. Input data is never modified. {@link HashFunction} instances should always be
 *       stateless, and therefore thread-safe.
 *   <li><b>collision-averse:</b> while it can't be helped that a hash function will sometimes
 *       produce the same hash code for distinct inputs (a "collision"), every hash function strives

 *
 * <p>This class supports an optional fairness policy for ordering waiting producer and consumer
 * threads. By default, this ordering is not guaranteed. However, a queue constructed with fairness
 * set to {@code true} grants threads access in FIFO order. Fairness generally decreases throughput
 * but reduces variability and avoids starvation.
 *

 *
 * <p>As of Guava 23.0, this class is thread-safe and lock-free. It internally uses atomics and
 * compare-and-swap to ensure correctness when multiple threads are used to access it.
 *
 * @param <T> the type of instances that the {@code BloomFilter} accepts
 * @author Dimitris Andreou
 * @author Kevin Bourrillion
 * @since 11.0 (thread-safe since 23.0)
 */
@Beta
@ElementTypesAreNonnullByDefault

{* ../../docs_src/sql_databases/tutorial001_an_py310.py ln[14:18] hl[14:15,17:18] *}

Usar `check_same_thread=False` permite que o FastAPI use o mesmo banco de dados SQLite em diferentes threads. Isso é necessário, pois **uma única requisição** pode usar **mais de uma thread** (por exemplo, em dependências).

    val response = call.execute()
    val inputStream = response.body.byteStream()
    assertThat(inputStream.read()).isEqualTo('A'.code)
    assertThat(inputStream.read()).isEqualTo('B'.code)
    assertThat(inputStream.read()).isEqualTo('C'.code)
    assertThat(inputStream.read()).isEqualTo(-1)
    assertThat(inputStream.read()).isEqualTo(-1)
    inputStream.close()
  }

  @ParameterizedTest

*p += i
</pre>

<p>
If <code>i</code> and <code>*p</code> start equal to 2,
the original code does <code>*p = 3</code>,
so a racing thread can read only 2 or 3 from <code>*p</code>.
The rewritten code does <code>*p = 1</code> and then <code>*p = 3</code>,
allowing a racing thread to read 1 as well.
</p>

<p>
Note that all these optimizations are permitted in C/C++ compilers: