content: package org.apache.lucene.util;
  
  /**
   * 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.
   */
  
  import java.util.concurrent.TimeUnit;
  import java.util.concurrent.locks.Lock;
  import java.util.concurrent.locks.Condition;
  import java.util.concurrent.locks.ReentrantLock;
  
  /**
   * A dummy lock as a replacement for {@link ReentrantLock} to disable locking
   * @lucene.internal
   */
  public final class DummyConcurrentLock implements Lock {
  
    /** a default instance, can be always used, as this {@link Lock} is stateless. */
    public static final DummyConcurrentLock INSTANCE = new DummyConcurrentLock();
  
    public void lock() {}
    
    public void lockInterruptibly() {}
    
    public boolean tryLock() {
      return true;
    }
    
    public boolean tryLock(long time, TimeUnit unit) {
      return true;
    }
    
    public void unlock() {}
    
    public Condition newCondition() {
      throw new UnsupportedOperationException();
    }
  
  }
  