content: /*
   * The Alluxio Open Foundation licenses this work under the Apache License, version 2.0
   * (the "License"). You may not use this work except in compliance with the License, which is
   * available at www.apache.org/licenses/LICENSE-2.0
   *
   * This software is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
   * either express or implied, as more fully set forth in the License.
   *
   * See the NOTICE file distributed with this work for information regarding copyright ownership.
   */
  
  package alluxio.resource;
  
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertFalse;
  import static org.junit.Assert.assertTrue;
  
  import org.junit.Test;
  
  import java.util.concurrent.locks.Lock;
  import java.util.concurrent.locks.ReentrantLock;
  import java.util.concurrent.locks.ReentrantReadWriteLock;
  
  /**
   * Unit tests for {@link LockResource}.
   */
  public final class LockResourceTest {
  
    /**
     * Tests {@link LockResource} with {@link ReentrantLock}.
     */
    @Test
    public void reentrantLock() {
      Lock lock = new ReentrantLock();
      try (LockResource r1 = new LockResource(lock)) {
        try (LockResource r2 = new LockResource(lock)) {
          assertTrue(lock.tryLock());
          lock.unlock();
        }
      }
    }
  
    /**
     * Tests {@link LockResource} with {@link ReentrantLock}.
     */
    @Test
    public void reentrantTryLock() {
      Lock lock = new ReentrantLock();
      try (LockResource r1 = new LockResource(lock, true, true)) {
        try (LockResource r2 = new LockResource(lock, true, true)) {
          assertTrue(lock.tryLock());
          lock.unlock();
        }
      }
    }
  
    /**
     * Tests {@link LockResource} with {@link ReentrantReadWriteLock}.
     */
    @Test
    public void reentrantReadWriteLock() {
      ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
  
      try (LockResource r1 = new LockResource(lock.readLock())) {
        try (LockResource r2 = new LockResource(lock.readLock())) {
          assertEquals(lock.getReadHoldCount(), 2);
          assertTrue(lock.readLock().tryLock());
          lock.readLock().unlock();
        }
      }
      assertEquals(lock.getReadHoldCount(), 0);
  
      try (LockResource r1 = new LockResource(lock.writeLock())) {
        try (LockResource r2 = new LockResource(lock.readLock())) {
          assertTrue(lock.isWriteLockedByCurrentThread());
          assertEquals(lock.getReadHoldCount(), 1);
        }
      }
      assertFalse(lock.isWriteLockedByCurrentThread());
      assertEquals(lock.getReadHoldCount(), 0);
  
      try (LockResource r = new LockResource(lock.readLock())) {
        assertFalse(lock.writeLock().tryLock());
      }
    }
  }
  