public Boolean get() {
            // Check that this method is called exactly once, by the first
            // thread to synchronize.
            long t0 = System.nanoTime();
            while (waitingThreads() != numThreads - 1) {
              if (System.nanoTime() - t0 > timeout) {
                thrown.set(
                    new TimeoutException(
                        "timed out waiting for other threads to block"

          public Boolean get() {
            // Check that this method is called exactly once, by the first
            // thread to synchronize.
            long t0 = System.nanoTime();
            while (waitingThreads() != numThreads - 1) {
              if (System.nanoTime() - t0 > timeout) {
                thrown.set(
                    new TimeoutException(
                        "timed out waiting for other threads to block"

    if (profileTests) runTestProfiled();
    else super.runTest();
  }

  protected void runTestProfiled() throws Throwable {
    long t0 = System.nanoTime();
    try {
      super.runTest();
    } finally {
      long elapsedMillis = (System.nanoTime() - t0) / (1000L * 1000L);
      if (elapsedMillis >= profileThreshold)
        System.out.printf("%n%s: %d%n", toString(), elapsedMillis);
    }
  }