PoolLatchUtil.java

package org.opensource.clearpool.util;

import java.util.concurrent.CountDownLatch;

import org.opensource.clearpool.exception.ConnectionPoolException;

/**
 * This class's duty is to control the order of the thread running.It make sure the daemon thread is
 * running when the main thread returned.
 * 
 * @author xionghui
 * @date 26.07.2014
 * @version 1.0
 */
public class PoolLatchUtil {
  // 2 hooks: IdleCheckHook and HtmlAdaptorHook.
  private static CountDownLatch startLatch = new CountDownLatch(2);

  private PoolLatchUtil() {}

  /**
   * Count down startLatch.
   */
  public static void countDownStartLatch() {
    if (startLatch != null) {
      startLatch.countDown();
    }
  }

  /**
   * Wait one time.
   */
  public static void await() {
    try {
      if (startLatch != null) {
        startLatch.await();
        // help gc
        startLatch = null;
      }
    } catch (InterruptedException e) {
      throw new ConnectionPoolException(e);
    }
  }
}