content: //
  // 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 com.cloud.network.nicira;
  
  import static org.hamcrest.MatcherAssert.assertThat;
  import static org.hamcrest.Matchers.equalTo;
  
  import java.util.concurrent.ExecutorService;
  import java.util.concurrent.Executors;
  import java.util.concurrent.TimeUnit;
  import java.util.concurrent.atomic.AtomicInteger;
  
  import org.junit.Test;
  
  public class ExecutionCounterTest {
  
      @Test
      public void testIncrementCounter() throws Exception {
          final ExecutionCounter executionCounter = new ExecutionCounter(-1);
  
          executionCounter.incrementExecutionCounter().incrementExecutionCounter();
  
          assertThat(executionCounter.getValue(), equalTo(2));
      }
  
      @Test
      public void testHasNotYetReachedTheExecutuionLimit() throws Exception {
          final ExecutionCounter executionCounter = new ExecutionCounter(2);
  
          executionCounter.incrementExecutionCounter();
  
          assertThat(executionCounter.hasReachedExecutionLimit(), equalTo(false));
      }
  
      @Test
      public void testHasAlreadyReachedTheExecutuionLimit() throws Exception {
          final ExecutionCounter executionCounter = new ExecutionCounter(2);
  
          executionCounter.incrementExecutionCounter().incrementExecutionCounter();
  
          assertThat(executionCounter.hasReachedExecutionLimit(), equalTo(true));
      }
  
      @Test
      public void testConcurrentUpdatesToCounter() throws Exception {
          final ExecutionCounter executionCounter = new ExecutionCounter(0);
          final ExecutorService executorService = Executors.newFixedThreadPool(3);
          final AtomicInteger counterTask1 = new AtomicInteger(-1);
          final AtomicInteger counterTask2 = new AtomicInteger(-1);
          final AtomicInteger counterTask3 = new AtomicInteger(-1);
  
          final Runnable task1 = new Runnable() {
              @Override
              public void run() {
                  executionCounter.incrementExecutionCounter().incrementExecutionCounter();
                  executionCounter.incrementExecutionCounter().incrementExecutionCounter();
                  counterTask1.set(executionCounter.getValue());
              }
          };
          final Runnable task2 = new Runnable() {
              @Override
              public void run() {
                  executionCounter.incrementExecutionCounter().incrementExecutionCounter();
                  counterTask2.set(executionCounter.getValue());
              }
          };
          final Runnable task3 = new Runnable() {
              @Override
              public void run() {
                  counterTask3.set(executionCounter.getValue());
              }
          };
  
          executorService.execute(task1);
          executorService.execute(task2);
          executorService.execute(task3);
  
          executorService.shutdown();
          executorService.awaitTermination(5L, TimeUnit.SECONDS);
  
          assertThat(counterTask1.get(), equalTo(4));
          assertThat(counterTask2.get(), equalTo(2));
          assertThat(counterTask3.get(), equalTo(0));
      }
  }
  