/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements. See the NOTICE file distributed with this
 * work for additional information regarding copyright ownership. The ASF
 * licenses this file to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */
package org.apache.knox.gateway.util;

import java.util.concurrent.ExecutorService;
import java.util.concurrent.TimeUnit;

public class ExecutorServiceUtils {

  public static void shutdownAndAwaitTermination(ExecutorService executorService, long timeout, TimeUnit timeUnit) {
    executorService.shutdown(); // Disable new tasks from being submitted
    try {
      // Wait a while for existing tasks to terminate
      if (!executorService.awaitTermination(timeout, timeUnit)) {
        executorService.shutdownNow(); // Cancel currently executing tasks
        // Wait a while for tasks to respond to being cancelled
        if (!executorService.awaitTermination(timeout, timeUnit)) {
          System.err.println("Pool did not terminate");
        }
      }
    } catch (InterruptedException ie) {
      // (Re-)Cancel if current thread also interrupted
      executorService.shutdownNow();
      // Preserve interrupt status
      Thread.currentThread().interrupt();
    }
  }

}
