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 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();
          }
      }
  }