UtilsForTests.java 文件源码

/** The waiting function.  The reduce exits once it gets a signal. Here the
 * signal is the file existence. 
 */
public void reduce(WritableComparable key, Iterator<Writable> val, 
                   OutputCollector<WritableComparable, Writable> output,
                   Reporter reporter)
throws IOException {
  if (fs != null) {
    while (!fs.exists(signal)) {
      try {
        reporter.progress();
        synchronized (this) {
          this.wait(1000); // wait for 1 sec
        }
      } catch (InterruptedException ie) {
        System.out.println("Interrupted while the map was waiting for the"
                           + " signal.");
        break;
      }
    }
  } else {
    throw new IOException("Could not get the DFS!!");
  }
}