*
     * @param manager channel manager
     */
    public ChannelFailover(ChannelManager manager) {
        this.manager = manager;
        this.executor = Executors.newCachedThreadPool(r -> {
            Thread t = new Thread(r, "MultiChannelFailover");
            t.setDaemon(true);
            return t;
        });
        this.failoverStates = new ConcurrentHashMap<>();
    }

    /**
     * Handle channel failure
     *

  /**
   * Cached value of #publicSuffixIndex(). Do not use directly.
   *
   * <p>Since this field isn't {@code volatile}, if an instance of this class is shared across
   * threads before it is initialized, then each thread is likely to compute their own copy of the
   * value.
   */
  @SuppressWarnings("Immutable")
  @LazyInit
  private int publicSuffixIndexCache = SUFFIX_NOT_INITIALIZED;

  /**

                }
            });
            readThreads[i].start();
        }

        // Wait for all threads
        for (Thread thread : updateThreads) {
            thread.join(5000);
        }
        for (Thread thread : readThreads) {
            thread.join(5000);
        }

        // Verify final state
        assertEquals(100, entry.getChildren().size());

    }

    public void test_thread_priority_settings() {
        // Test basic priority configurations without creating threads
        dataIndexHelper.setCrawlerPriority(Thread.MIN_PRIORITY);
        dataIndexHelper.setCrawlerPriority(Thread.NORM_PRIORITY);
        dataIndexHelper.setCrawlerPriority(Thread.MAX_PRIORITY);
        assertTrue("Priority settings should be fast", true);
    }

Mas antes disso, controlar código assíncrono era bem mais complexo e difícil.

Nas versões anteriores do Python, você poderia utilizar threads ou <a href="http://www.gevent.org/" class="external-link" target="_blank">Gevent</a>. Mas o código é bem mais complexo de entender, debugar, e pensar sobre.

      --enable-gnu-unique-object \
      --enable-initfini-array \
      --enable-languages="c,c++" \
      --enable-linker-build-id \
      --enable-plugin \
      --enable-shared \
      --enable-threads=posix \
      --with-default-libstdcxx-abi=${LIBSTDCXX_ABI} \
      --with-gcc-major-version-only \
      --with-linker-hash-style="gnu" \
      && \
      make -j$(nproc) && \
      make install

     * as well as to handle state changes in a thread-safe manner. The current state of the future
     * is held in the Sync state, and the lock is released whenever the state changes to {@link
     * #COMPLETED}, {@link #CANCELLED}, or {@link #INTERRUPTED}
     *
     * <p>To avoid races between threads doing release and acquire, we transition to the final state

 * example involving two locks and two threads, deadlock occurs when one thread acquires Lock A, and
 * then Lock B, while another thread acquires Lock B, and then Lock A:
 *
 * <pre>
 * Thread1: acquire(LockA) --X acquire(LockB)
 * Thread2: acquire(LockB) --X acquire(LockA)
 * </pre>
 *
 * <p>Neither thread will progress because each is waiting for the other. In more complex

    //
    // TODO(user): Consider using
    // java/lang/management/OperatingSystemMXBean.html#getSystemLoadAverage()
    //
    // TODO(user): Consider scaling by number of mutator threads,
    // e.g. using Thread#activeCount()
    return max(10L, Runtime.getRuntime().totalMemory() / (32L * 1024L * 1024L));
  }

  /**

Si vous avez de bonnes connaissances techniques (coroutines, threads, code bloquant, etc.) et êtes curieux de comment **FastAPI** gère `async def` versus le `def` classique, cette partie est faite pour vous.

///

### Fonctions de chemin