hadoop-hdds/common/src/main/java/org/apache/hadoop/ozone/lock/BootstrapStateHandler.java

/**
 * 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
 * <p>
 * http://www.apache.org/licenses/LICENSE-2.0
 * <p>
 * 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.
 */

package org.apache.hadoop.ozone.lock;

import java.util.concurrent.Semaphore;

/** Bootstrap state handler interface. */
public interface BootstrapStateHandler {
  Lock getBootstrapStateLock();

  /** Bootstrap state handler lock implementation. */
  class Lock implements AutoCloseable {
    private final Semaphore semaphore = new Semaphore(1);
    public Lock lock() throws InterruptedException {
      semaphore.acquire();
      return this;
    }
    public void unlock() {
      semaphore.release();
    }
    public void close() {
      unlock();
    }
  }
}