// Setting a security manager causes the common ForkJoinPool to use InnocuousThreads with no
    // permissions.
    // submit()/join() causes this thread to execute the task instead, so we use a CountDownLatch as
    // a barrier to synchronize.
    // TODO(cpovirk): If some other test already initialized commonPool(), this won't work :(
    // Maybe we should just run this test in its own VM.
    ForkJoinPool.commonPool()
        .execute(