@Override
          public void run() {
            list.execute();
          }
        };
    Thread thread1 = new Thread(execute);
    Thread thread2 = new Thread(execute);
    thread1.start();
    thread2.start();
    assertEquals(0, runCalled.get());
    okayToRun.countDown();
    thread1.join();
    thread2.join();
    assertEquals(1, runCalled.get());
  }

      }
      return;
    }

    /*
     * This is an unsynchronized read! After the read, the function returns immediately or acquires
     * the lock to check again. Since an IDLE state was observed inside the preceding synchronized
     * block, and reference field assignment is atomic, this may save reacquiring the lock when
     * another thread or the worker task has cleared the count and set the state.
     *

      }
      return;
    }

    /*
     * This is an unsynchronized read! After the read, the function returns immediately or acquires
     * the lock to check again. Since an IDLE state was observed inside the preceding synchronized
     * block, and reference field assignment is atomic, this may save reacquiring the lock when
     * another thread or the worker task has cleared the count and set the state.
     *

   * As such, this field must be cleared before every map mutation.
   *
   * Note about volatile: volatile doesn't make it safe to read from a mutable graph in one thread
   * while writing to it in another. All it does is help with _reading_ from multiple threads
   * concurrently. For more information, see AbstractNetworkTest.concurrentIteration.
   */

            });
    assertFalse(task.isDone());
    Thread thread =
        new Thread(
            new Runnable() {
              @Override
              public void run() {
                try {
                  task.run();
                } finally {
                  exitLatch.countDown();
                }
              }
            });
    thread.start();
    enterLatch.await();

    List<Thread> threads = new ArrayList<>(numThreads);
    final List<Throwable> exceptions = new ArrayList<>(numThreads);
    for (int i = 0; i < numThreads; i++) {
      Thread thread = new Thread(task);
      thread.setUncaughtExceptionHandler(
          new UncaughtExceptionHandler() {
            @Override
            public void uncaughtException(Thread t, Throwable e) {

     *       observing a null thread does not mean the object is safe to reuse.
     *   <li>If this field's value is some other thread object, we know that it's not our thread.
     *   <li>If this field's value == null because it originally belonged to another thread and that
     *       thread cleared it, we still know that it's not associated with our thread

  /**
   * Returns an exception handler that exits the system. This is particularly useful for the main
   * thread, which may start up other, non-daemon threads, but fail to fully initialize the
   * application successfully.
   *
   * <p>Example usage:
   *
   * <pre>
   * public static void main(String[] args) {
   *   Thread.currentThread().setUncaughtExceptionHandler(UncaughtExceptionHandlers.systemExit());
   *   ...
   * </pre>
   *

On Windows, [Current] now returns the process owner user when
the current thread is impersonating another user. Previously,

      throw AssertionError("Thread ${Thread.currentThread().name} MUST hold lock on $this")
    }
  }

  @Suppress("NOTHING_TO_INLINE")
  internal inline fun Any.assertThreadDoesntHoldLock() {
    if (assertionsEnabled && taskRunner.lock.isHeldByCurrentThread) {
      throw AssertionError("Thread ${Thread.currentThread().name} MUST NOT hold lock on $this")
    }
  }