Method toSafeNanos

output/java_guava/1.4.19/Monitor.java:972–977

Returns unit.toNanos(time), additionally ensuring the returned value is not at risk of overflowing or underflowing, by bounding the value between 0 and (Long.MAX_VALUE / 4) 3. Actually waiting for more than 219 years is not supported!

(long time, TimeUnit unit)

   */

  private static long toSafeNanos(long time, TimeUnit unit) {
    long timeoutNanos = unit.toNanos(time);
    return (timeoutNanos <= 0L) ? 0L : (timeoutNanos > (Long.MAX_VALUE / 4) * 3)
      ? (Long.MAX_VALUE / 4) * 3
      : timeoutNanos;
  }

  /**
   * Returns System.nanoTime() unless the timeout has already elapsed. Returns 0L if and only if the