LockingThread thread = new LockingThread(lockA);
    thread.start();

    thread.waitUntilHoldingLock();
    assertFalse(lockA.tryLock());

    thread.releaseLockAndFinish();
    assertTrue(lockA.tryLock());
  }

  public void testReentrantWriteLock_tryLock() throws Exception {
    LockingThread thread = new LockingThread(writeLockA);
    thread.start();

    LockingThread thread = new LockingThread(lockA);
    thread.start();

    thread.waitUntilHoldingLock();
    assertFalse(lockA.tryLock());

    thread.releaseLockAndFinish();
    assertTrue(lockA.tryLock());
  }

  public void testReentrantWriteLock_tryLock() throws Exception {
    LockingThread thread = new LockingThread(writeLockA);
    thread.start();

          protected void doStart() {
            new Thread() {
              @Override
              public void run() {
                notifyStarted();
                // We need to wait for the main thread to leave the ServiceManager.startAsync call
                // to
                // ensure that the thread running the failure callbacks is not the main thread.
                Uninterruptibles.awaitUninterruptibly(afterStarted);

        final ClassLoader context = Thread.currentThread().getContextClassLoader();
        try {
            final ClassLoader cl = new URLClassLoader(new URL[0], getClass().getClassLoader());
            Thread.currentThread().setContextClassLoader(cl);
            assertThat(ClassLoaderUtil.getClassLoader(TestCase.class), is(sameInstance(cl)));
        } finally {
            Thread.currentThread().setContextClassLoader(context);

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.

import org.apache.logging.log4j.Logger;

/**
 * A thread that reads from an input stream line by line and maintains a buffer of recent lines.
 * This class provides functionality to read input stream data asynchronously,
 * optionally process each line with a callback function, and maintain a circular buffer
 * of recent lines for retrieval.
 */
public class InputStreamThread extends Thread {
    /** Logger instance for this class */

 * is intended solely to help find problems during development.
 *
 * <p>The EventBus guarantees that it will not call a subscriber method from multiple threads
 * simultaneously, unless the method explicitly allows it by bearing the {@link
 * AllowConcurrentEvents} annotation. If this annotation is not present, subscriber methods need not

{* ../../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).

    Thread.currentThread().interrupt();
    try {
      getChecked(future, TwoArgConstructorException.class);
      fail();
    } catch (TwoArgConstructorException expected) {
      assertThat(expected).hasCauseThat().isInstanceOf(InterruptedException.class);
      assertTrue(Thread.currentThread().isInterrupted());
    } finally {
      Thread.interrupted();
    }
  }

            assertTrue(processHelper.isProcessRunning());

            // Wait a bit for the processes to start
            Thread.sleep(50);

            // Destroy all processes
            processHelper.destroy();

            // Wait a bit for destruction to complete
            Thread.sleep(100);

            assertFalse(processHelper.isProcessRunning());
        } catch (Exception e) {