@Override
    public boolean tryLock() {
      return writerSemaphore.tryAcquire();
    }
This ReadWriteLock is useful when different threads need to lock and unlock the read lock. This
is <b>NOT</b> a reentrant lock.
geode-core/src/main/java/org/apache/geode/internal/util/concurrent/SemaphoreReadWriteLock.java