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 org.apache.beam.runners.direct;
  
  import static org.mockito.Mockito.mock;
  import static org.mockito.Mockito.never;
  import static org.mockito.Mockito.verify;
  
  import java.util.concurrent.ExecutorService;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.util.concurrent.MoreExecutors;
  import org.junit.Before;
  import org.junit.Rule;
  import org.junit.Test;
  import org.junit.rules.ExpectedException;
  import org.junit.runner.RunWith;
  import org.junit.runners.JUnit4;
  
  /** Tests for {@link TransformExecutorServices}. */
  @RunWith(JUnit4.class)
  public class TransformExecutorServicesTest {
    @Rule public ExpectedException thrown = ExpectedException.none();
  
    private ExecutorService executorService;
  
    @Before
    public void setup() {
      executorService = MoreExecutors.newDirectExecutorService();
    }
  
    @Test
    public void parallelScheduleMultipleSchedulesBothImmediately() {
      @SuppressWarnings("unchecked")
      DirectTransformExecutor<Object> first = mock(DirectTransformExecutor.class);
      @SuppressWarnings("unchecked")
      DirectTransformExecutor<Object> second = mock(DirectTransformExecutor.class);
  
      TransformExecutorService parallel = TransformExecutorServices.parallel(executorService);
      parallel.schedule(first);
      parallel.schedule(second);
  
      verify(first).run();
      verify(second).run();
  
      parallel.complete(first);
      parallel.complete(second);
    }
  
    @Test
    public void parallelRejectedStillActiveThrows() {
      @SuppressWarnings("unchecked")
      DirectTransformExecutor<Object> first = mock(DirectTransformExecutor.class);
  
      TransformExecutorService parallel = TransformExecutorServices.parallel(executorService);
      executorService.shutdown();
      thrown.expect(IllegalStateException.class);
      thrown.expectMessage("still active");
      parallel.schedule(first);
    }
  
    @Test
    public void parallelRejectedShutdownSucceeds() {
      @SuppressWarnings("unchecked")
      DirectTransformExecutor<Object> first = mock(DirectTransformExecutor.class);
  
      TransformExecutorService parallel = TransformExecutorServices.parallel(executorService);
      executorService.shutdown();
      parallel.shutdown();
      parallel.schedule(first);
    }
  
    @Test
    public void serialScheduleTwoWaitsForFirstToComplete() {
      @SuppressWarnings("unchecked")
      DirectTransformExecutor<Object> first = mock(DirectTransformExecutor.class);
      @SuppressWarnings("unchecked")
      DirectTransformExecutor<Object> second = mock(DirectTransformExecutor.class);
  
      TransformExecutorService serial = TransformExecutorServices.serial(executorService);
      serial.schedule(first);
      verify(first).run();
  
      serial.schedule(second);
      verify(second, never()).run();
  
      serial.complete(first);
      verify(second).run();
  
      serial.complete(second);
    }
  
    @Test
    public void serialCompleteNotExecutingTaskThrows() {
      @SuppressWarnings("unchecked")
      DirectTransformExecutor<Object> first = mock(DirectTransformExecutor.class);
      @SuppressWarnings("unchecked")
      DirectTransformExecutor<Object> second = mock(DirectTransformExecutor.class);
  
      TransformExecutorService serial = TransformExecutorServices.serial(executorService);
      serial.schedule(first);
      thrown.expect(IllegalStateException.class);
      thrown.expectMessage("unexpected currently executing");
  
      serial.complete(second);
    }
  
    /**
     * Tests that a Serial {@link TransformExecutorService} does not schedule follow up work if the
     * executor is shut down when the initial work completes.
     */
    @Test
    public void serialShutdownCompleteActive() {
      @SuppressWarnings("unchecked")
      DirectTransformExecutor<Object> first = mock(DirectTransformExecutor.class);
      @SuppressWarnings("unchecked")
      DirectTransformExecutor<Object> second = mock(DirectTransformExecutor.class);
  
      TransformExecutorService serial = TransformExecutorServices.serial(executorService);
      serial.schedule(first);
      verify(first).run();
  
      serial.schedule(second);
      verify(second, never()).run();
  
      serial.shutdown();
      serial.complete(first);
      verify(second, never()).run();
    }
  }
  