/*
 * 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 WARRANTIESOR 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.aries.blueprint.utils.threading;

import java.util.concurrent.Callable;
import java.util.concurrent.locks.ReentrantReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock.ReadLock;
import java.util.concurrent.locks.ReentrantReadWriteLock.WriteLock;

public class RWLock
{
  private ReentrantReadWriteLock _lock = new ReentrantReadWriteLock();
  
  public <T> T runReadOperation(Callable<T> call) throws Exception
  {
    ReadLock rl = _lock.readLock();
    rl.lock();
    try {
      return call.call();
    } finally {
      rl.unlock();
    }
  }
  
  public void runReadOperation(Runnable r)
  {
    ReadLock rl = _lock.readLock();
    rl.lock();
    try {
      r.run();
    } finally {
      rl.unlock();
    }
  }
  
  public <T> T runWriteOperation(Callable<T> call) throws Exception
  {
    WriteLock wl = _lock.writeLock();
    wl.lock();
    try {
      return call.call();
    } finally {
      wl.unlock();
    }
  }
  
  public void runWriteOperation(Runnable r)
  {
    WriteLock wl = _lock.writeLock();
    wl.lock();
    try {
      r.run();
    } finally {
      wl.unlock();
    }
  }
}