/*
    * 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.surefire.api.util.internal;
  
  import java.util.concurrent.ExecutionException;
  import java.util.concurrent.FutureTask;
  import java.util.concurrent.atomic.AtomicBoolean;
  import java.util.concurrent.atomic.AtomicInteger;
  
  import org.junit.Test;
  
  import static org.apache.maven.surefire.api.util.internal.ConcurrencyUtils.runIfZeroCountDown;
  import static org.hamcrest.MatcherAssert.assertThat;
  import static org.hamcrest.Matchers.is;
  import static org.junit.Assert.assertFalse;
  import static org.junit.Assert.assertTrue;
  
  /**
   * Concurrency utilities.
   *
   * @author <a href="mailto:tibordigana@apache.org">Tibor Digana (tibor17)</a>
   * @since 2.19
   */
  public class ConcurrencyUtilsTest {
  
      @Test
      public void countDownShouldBeUnchangedAsZeroNegativeTest() {
          AtomicInteger atomicCounter = new AtomicInteger(0);
          AtomicBoolean runner = new AtomicBoolean();
          runIfZeroCountDown(() -> runner.set(true), atomicCounter);
          assertFalse(runner.get());
          assertThat(atomicCounter.get(), is(0));
      }
  
      @Test
      public void countDownShouldBeUnchangedAsNegativeNegativeTest() {
          AtomicInteger atomicCounter = new AtomicInteger(-1);
          AtomicBoolean runner = new AtomicBoolean();
          runIfZeroCountDown(() -> runner.set(true), atomicCounter);
          assertFalse(runner.get());
          assertThat(atomicCounter.get(), is(-1));
      }
  
      @Test
      public void countDownShouldBeDecreasedByOneThreadModification() {
          AtomicInteger atomicCounter = new AtomicInteger(10);
          AtomicBoolean runner = new AtomicBoolean();
          runIfZeroCountDown(() -> runner.set(true), atomicCounter);
          assertFalse(runner.get());
          assertThat(atomicCounter.get(), is(9));
      }
  
      @Test
      public void countDownToZeroShouldBeDecreasedByOneThreadModification() {
          AtomicInteger atomicCounter = new AtomicInteger(1);
          AtomicBoolean runner = new AtomicBoolean();
          runIfZeroCountDown(() -> runner.set(true), atomicCounter);
          assertTrue(runner.get());
          assertThat(atomicCounter.get(), is(0));
      }
  
      @Test
      public void countDownShouldBeDecreasedByTwoThreadsModification() throws ExecutionException, InterruptedException {
          AtomicInteger atomicCounter = new AtomicInteger(3);
  
          FutureTask<Boolean> task = new FutureTask<>(() -> {
              AtomicBoolean runner = new AtomicBoolean();
              runIfZeroCountDown(() -> runner.set(true), atomicCounter);
              return runner.get();
          });
          Thread t = new Thread(task);
          t.start();
  
          AtomicBoolean runner = new AtomicBoolean();
          runIfZeroCountDown(() -> runner.set(true), atomicCounter);
          assertFalse(runner.get());
  
          assertFalse(task.get());
  
          assertThat(atomicCounter.get(), is(1));
  
          runner.set(false);
          runIfZeroCountDown(() -> runner.set(true), atomicCounter);
         assertTrue(runner.get());
 
         assertThat(atomicCounter.get(), is(0));
     }
 }