t.Errorf("TestSimpleWriteLockTimedOut(): \nexpected %#v\ngot      %#v", expected, locked)
	}
}

func testDualWriteLock(t *testing.T, duration time.Duration) (locked bool) {
	drwm1 := NewDRWMutex(ds, "duallock")

	// fmt.Println("Getting initial write lock")
	ctx1, cancel1 := context.WithCancel(context.Background())
	if !drwm1.GetLock(ctx1, cancel1, id, source, Options{Timeout: time.Second}) {

 *       "safe" edge is created.
 *   <li>If a cycle is detected, an "unsafe" (cyclic) edge is created to represent a potential
 *       deadlock situation, and the appropriate Policy is executed.
 * </ul>
 *
 * <p>Note that detection of potential deadlock does not necessarily indicate that deadlock will
 * happen, as it is possible that higher level application logic prevents the cyclic lock

    assertSame(firstException.getCause(), expected.getCause());
    // lockA should work after lockB is released.
    lockB.unlock();
    lockA.lock();
  }

  // Tests transitive deadlock detection.
  public void testDeadlock_threeLocks() {
    // Establish an ordering from lockA -> lockB.
    lockA.lock();
    lockB.lock();
    lockB.unlock();
    lockA.unlock();

WebAssembly.instantiate(fs.readFileSync(process.argv[2]), go.importObject).then((result) => {
	process.on("exit", (code) => { // Node.js exits if no event handler is pending
		if (code === 0 && !go.exited) {
			// deadlock, make Go print error and stack traces
			go._pendingEvent = { id: 0 };
			go._resume();
		}
	});
	return go.run(result.instance);
}).catch((err) => {
	console.error(err);
	process.exit(1);

    assertSame(firstException.getCause(), expected.getCause());
    // lockA should work after lockB is released.
    lockB.unlock();
    lockA.lock();
  }

  // Tests transitive deadlock detection.
  public void testDeadlock_threeLocks() {
    // Establish an ordering from lockA -> lockB.
    lockA.lock();
    lockB.lock();
    lockB.unlock();
    lockA.unlock();

    Thread.sleep(UNIT.toMillis(3 * DELAY));
    assertEquals(1, service.numIterations.get());
  }

  public void testCustomScheduler_deadlock() throws InterruptedException, BrokenBarrierException {
    final CyclicBarrier inGetNextSchedule = new CyclicBarrier(2);
    // This will flakily deadlock, so run it multiple times to increase the flake likelihood
    for (int i = 0; i < 1000; i++) {
      Service service =

import junit.framework.TestCase;
import org.checkerframework.checker.nullness.qual.Nullable;

public final class InterruptibleTaskTest extends TestCase {

  // Regression test for a deadlock where a task could be stuck busy waiting for the task to
  // transition to DONE
  public void testInterruptThrows() throws Exception {
    final CountDownLatch isInterruptibleRegistered = new CountDownLatch(1);

    Thread.sleep(UNIT.toMillis(3 * DELAY));
    assertEquals(1, service.numIterations.get());
  }

  public void testCustomScheduler_deadlock() throws InterruptedException, BrokenBarrierException {
    final CyclicBarrier inGetNextSchedule = new CyclicBarrier(2);
    // This will flakily deadlock, so run it multiple times to increase the flake likelihood
    for (int i = 0; i < 1000; i++) {
      Service service =

The reader thread must never run application-layer code. Otherwise one slow stream can hold up the entire connection.

import junit.framework.TestCase;
import org.checkerframework.checker.nullness.qual.Nullable;

public final class InterruptibleTaskTest extends TestCase {

  // Regression test for a deadlock where a task could be stuck busy waiting for the task to
  // transition to DONE
  public void testInterruptThrows() throws Exception {
    final CountDownLatch isInterruptibleRegistered = new CountDownLatch(1);