//
        // Note that there is a race condition here which can result in missing
        // a cyclic edge: it's possible for two threads to simultaneous find
        // "safe" edges which together form a cycle. Preventing this race
        // condition efficiently without _introducing_ deadlock is probably
        // tricky. For now, just accept the race condition---missing a warning

                for (int j = 0; j < 100; j++) {
                    List<DirectoryCacheEntry.FileInfo> children = entry.getChildren();
                    // Just read, don't assert specific counts due to race conditions
                    assertNotNull(children);
                }
            });
            readThreads[i].start();
        }

        // Wait for all threads

      putNext(this, next);
    }

    void unpark() {
      // This is racy with removeWaiter. The consequence of the race is that we may spuriously call
      // unpark even though the thread has already removed itself from the list. But even if we did
      // use a CAS, that race would still exist (it would just be ever so slightly smaller).
      Thread w = thread;
      if (w != null) {
        thread = null;

        assertTrue("Threads did not complete in time", doneLatch.await(5, TimeUnit.SECONDS));

        // All threads should fail with the same IOException (project ID is blank)
        // But importantly, there should be no race condition errors
        assertEquals(threadCount, failureCount.get());
        assertEquals(0, successCount.get());

        // All exceptions should be about project ID being blank

type Target struct {
	status int32

	totalMessages  int64
	failedMessages int64

	wg sync.WaitGroup

	// Channel of log entries.
	// Reading logCh must hold read lock on logChMu (to avoid read race)
	// Sending a value on logCh must hold read lock on logChMu (to avoid closing)
	logCh   chan any
	logChMu sync.RWMutex

	// store to persist and replay the logs to the target

      putNext(this, next);
    }

    void unpark() {
      // This is racy with removeWaiter. The consequence of the race is that we may spuriously call
      // unpark even though the thread has already removed itself from the list. But even if we did
      // use a CAS, that race would still exist (it would just be ever so slightly smaller).
      Thread w = thread;
      if (w != null) {
        thread = null;

        assertTrue("Threads did not complete in time", doneLatch.await(5, TimeUnit.SECONDS));

        // All threads should fail with the same IOException (endpoint is blank)
        // But importantly, there should be no race condition errors
        assertEquals(threadCount, failureCount.get());
        assertEquals(0, successCount.get());

        // All exceptions should be about endpoint being blank
        for (Exception e : exceptions) {

      long nanos = expirationNanos;
      long now = System.nanoTime();
      if (nanos == 0 || now - nanos >= 0) {
        synchronized (lock) {
          if (nanos == expirationNanos) { // recheck for lost race
            T t = delegate.get();
            value = t;
            nanos = now + durationNanos;
            // In the very unlikely event that nanos is 0, set it to 1;

    thread.join();
    // It's possible to race and suspend the thread just before the park call actually takes effect,
    // causing the thread to be suspended for 3.5 seconds, and then park itself for 2 seconds after
    // being resumed. To avoid a flake in this scenario, calculate how long that thread actually
    // waited and assert based on that time. Empirically, the race where the thread ends up waiting

    thread.join();
    // It's possible to race and suspend the thread just before the park call actually takes effect,
    // causing the thread to be suspended for 3.5 seconds, and then park itself for 2 seconds after
    // being resumed. To avoid a flake in this scenario, calculate how long that thread actually
    // waited and assert based on that time. Empirically, the race where the thread ends up waiting