/*
    * 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.maven.lifecycle.internal.concurrent;
  
  import java.util.concurrent.Executor;
  import java.util.concurrent.ExecutorService;
  import java.util.concurrent.Phaser;
  
  public class PhasingExecutor implements Executor, AutoCloseable {
      private final ExecutorService executor;
      private final Phaser phaser = new Phaser();
  
      public PhasingExecutor(ExecutorService executor) {
          this.executor = executor;
          this.phaser.register();
      }
  
      @Override
      public void execute(Runnable command) {
          phaser.register();
          executor.submit(() -> {
              try {
                  command.run();
              } finally {
                  phaser.arriveAndDeregister();
              }
          });
      }
  
      public void await() {
          phaser.arriveAndAwaitAdvance();
      }
  
      @Override
      public void close() {
          executor.shutdownNow();
      }
  }