Review

18

/Users/svenamann/Documents/MUBench/mubench.pipeline/../checkouts/lucene/1918/original-src/org/apache/lucene/store/Lock.java

obtain(long)

class Lock {
  /** Attempts to obtain an exclusive lock within amount of
   *  time given. Polls once per {@link #LOCK_POLL_INTERVAL}
   *  (currently 1000) milliseconds until lockWaitTimeout is
   *  passed.
   * @param lockWaitTimeout length of time to wait in
   *        milliseconds or {@link
   *        #LOCK_OBTAIN_WAIT_FOREVER} to retry forever
   * @return true if lock was obtained
   * @throws LockObtainFailedException if lock wait times out
   * @throws IllegalArgumentException if lockWaitTimeout is
   *         out of bounds
   * @throws IOException if obtain() throws IOException
   */
  public boolean obtain(long lockWaitTimeout) throws LockObtainFailedException, IOException {
    failureReason = null;
    boolean locked = obtain();
    if (lockWaitTimeout < 0 && lockWaitTimeout != LOCK_OBTAIN_WAIT_FOREVER)
      throw new IllegalArgumentException("lockWaitTimeout should be LOCK_OBTAIN_WAIT_FOREVER or a non-negative number (got " + lockWaitTimeout + ")");

    long maxSleepCount = lockWaitTimeout / LOCK_POLL_INTERVAL;
    long sleepCount = 0;
    while (!locked) {
      if (lockWaitTimeout != LOCK_OBTAIN_WAIT_FOREVER && sleepCount++ >= maxSleepCount) {
        String reason = "Lock obtain timed out: " + this.toString();
        if (failureReason != null) {
          reason += ": " + failureReason;
        }
        LockObtainFailedException e = new LockObtainFailedException(reason);
        if (failureReason != null) {
          e.initCause(failureReason);
        }
        throw e;
      }
      try {
        Thread.sleep(LOCK_POLL_INTERVAL);
      } catch (InterruptedException e) {
        // In 3.0 we will change this to throw
        // InterruptedException instead
        Thread.currentThread().interrupt();
        throw new IOException(e.toString());
      }
      locked = obtain();
    }
    return locked;
  }

}