protected long getNow() {
    long result;
    Long tl = now.get();
    if (tl != null) {
      result = tl;
    } else {
      result = calculateNow();
    }
    return result;
  }
Returns the current time in milliseconds. If the current thread has set the now thread local
then that time is return. Otherwise now is calculated and returned.

@return the current time in milliseconds
geode-core/src/main/java/org/apache/geode/internal/cache/ExpiryTask.java