* Waits for a value that may still be loading. Unlike get(), this method can block (in the case
     * of FutureValueReference).
     *
     * @throws ExecutionException if the loading thread throws an exception
     * @throws ExecutionError if the loading thread throws an error
     */
    V waitForValue() throws ExecutionException;

    /** Returns the weight of this entry. This is assumed to be static between calls to setValue. */

* [LastaFlute](https://github.com/lastaflute/lastaflute "LastaFlute"): Framework Web
* [Lasta Job](https://github.com/lastaflute/lasta-job "Lasta Job"): Agendador de Tarefas
* [Fess Crawler](https://github.com/codelibs/fess-crawler "Fess Crawler"): Rastreador Web

Incluyendo cómo manejar el estado de lifespan que puede ser usado en otras áreas de tu código.

///

## Sub Aplicaciones { #sub-applications }

        if (metadataFile.length() == 0) {
            if (!metadataFile.delete()) {
                // sleep for 10ms just in case this is windows holding a file lock
                try {
                    Thread.sleep(10);
                } catch (InterruptedException e) {
                    // ignore
                }
                metadataFile.delete(); // if this fails, forget about it, we'll try to overwrite it anyway so no need

    }

    @Override
    protected Executor executor() {
      transitionStates.add(state());
      return directExecutor();
    }
  }

  // Functional tests using real thread. We only verify publicly visible state.
  // Interaction assertions are done by the single-threaded unit tests.

  private static class DefaultService extends AbstractIdleService {
    @Override

 * abused as a cache (i.e. for storing values that can be re-calculated) to avoid memory exhaustion.
 * <p>
 * <strong>Note:</strong> Actual implementations must be thread-safe.
 *
 * @see Session#getData()
 * @since 4.0.0
 */
@Experimental
@ThreadSafe
@Provider
public interface SessionData {

    /**
     * Associates the specified session data with the given key.

  static <E extends @Nullable Object> Set<E> newHashSetWithExpectedSize(int expectedSize) {
    return Sets.newHashSetWithExpectedSize(expectedSize);
  }

  /** Returns the platform preferred implementation of a thread-safe hash set. */
  static <E> Set<E> newConcurrentHashSet() {
    return ConcurrentHashMap.newKeySet();
  }

  /**
   * Returns the platform preferred implementation of an insertion ordered set based on a hash

Davor war der Umgang mit asynchronem Code jedoch deutlich komplexer und schwieriger.

In früheren Versionen von Python hätten Sie Threads oder <a href="https://www.gevent.org/" class="external-link" target="_blank">Gevent</a> verwenden können. Der Code ist jedoch viel komplexer zu verstehen, zu debuggen und nachzuvollziehen.

        new Callable<@Nullable Void>() {
          @Override
          public @Nullable Void call() throws Exception {
            // adds two nanoseconds to the ticker
            ticker.advance(1L);
            Thread.sleep(10);
            ticker.advance(1L);
            return null;
          }
        });

    assertEquals(numberOfThreads * 2, ticker.read());
  }

  @GwtIncompatible // concurrency

        if (logger.isDebugEnabled()) {
            logger.debug("Looking up lifecycle mappings for packaging " + packaging + " from "
                    + Thread.currentThread().getContextClassLoader());
        }

        LifecycleMapping lifecycleMappingForPackaging = lookupLifecycleMapping(packaging);

        if (lifecycleMappingForPackaging == null) {
            return null;