/*
 * INESC-ID, Instituto de Engenharia de Sistemas e Computadores Investigação e Desevolvimento em Lisboa
 * Copyright 2013 INESC-ID and/or its affiliates and other
 * contributors as indicated by the @author tags. All rights reserved.
 * See the copyright.txt in the distribution for a full listing of
 * individual contributors.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 3.0 of
 * the License, or (at your option) any later version.
 *
 * This software is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */
package org.infinispan.tx.gmu;

import junit.framework.Assert;
import org.infinispan.util.concurrent.locks.OwnableReentrantReadWriteLock;
import org.testng.annotations.Test;

import java.util.concurrent.TimeUnit;

import static junit.framework.Assert.assertEquals;

/**
 * // TODO: Document this
 *
 * @author Pedro Ruivo
 * @since 5.2
 */
@Test(groups = "functional", testName = "tx.gmu.OwnableReadWriteLockTest")
public class OwnableReadWriteLockTest {

   private static final long TIMEOUT = 10000;


   public void testMultipleRead() throws InterruptedException {
      OwnableReentrantReadWriteLock lock = newLock();
      Owner owner = owner(0);


      for (int i = 0; i < 100; i++) {
         lockShared(lock, owner, true);
      }

      assert lock.getLockState() == -100;

      for (int i = 0; i < 100; i++) {
         lock.unlockShare(owner);
      }

      assert lock.getLockState() == 0;
   }

   public void testReadWrite() throws InterruptedException {
      OwnableReentrantReadWriteLock lock = newLock();
      Owner owner = owner(0);

      lockShared(lock, owner, true);

      assert lock.getLockState() == -1;

      
      boolean result =lock.tryLock(owner, TIMEOUT, TimeUnit.MILLISECONDS);
      assert !result;
      
      assert lock.getLockState() == -1;
      
      lock.unlockShare(owner);
      
      assert lock.getLockState() == 0;
   }

   public void testWriteRead() throws InterruptedException {
      OwnableReentrantReadWriteLock lock = newLock();
      Owner owner = owner(0);
      
      lock.tryLock(owner, TIMEOUT, TimeUnit.MILLISECONDS);
      assert lock.getLockState() == 1;
      lockShared(lock, owner, true);
      assert lock.getLockState() == 1;
      lock.unlockShare(owner);
      assert lock.getLockState() == 1;
      lock.unlock(owner);
      assert lock.getLockState() == 0;
   }


   private Owner owner(int id) {
      return new Owner(id);
   }

   private OwnableReentrantReadWriteLock newLock() {
      return new OwnableReentrantReadWriteLock();
   }
   
   private void lockShared(OwnableReentrantReadWriteLock lock, Owner owner, boolean result) throws InterruptedException {
      boolean locked = lock.tryShareLock(owner, TIMEOUT, TimeUnit.MILLISECONDS);
      assertEquals(result, locked);
   }

   private static class Owner {
      private final int id;

      private Owner(int id) {
         this.id = id;
      }

      @Override
      public boolean equals(Object o) {
         if (this == o) return true;
         if (o == null || getClass() != o.getClass()) return false;

         Owner owner = (Owner) o;

         return id == owner.id;

      }

      @Override
      public int hashCode() {
         return id;
      }
   }

}