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 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.distributedlog.lock;
  
  import java.util.concurrent.CompletableFuture;
  import org.apache.distributedlog.exceptions.LockingException;
  import org.apache.distributedlog.io.AsyncCloseable;
  
  /**
   * Interface for distributed locking.
   */
  public interface DistributedLock extends AsyncCloseable {
  
      /**
       * Asynchronously acquire the lock.
       *
       * @return future represents the acquire result.
       */
      CompletableFuture<? extends DistributedLock> asyncAcquire();
  
      /**
       * Check if hold lock. If it doesn't, then re-acquire the lock.
       *
       * @throws LockingException if the lock attempt fails
       * @see #checkOwnership()
       */
      void checkOwnershipAndReacquire() throws LockingException;
  
      /**
       * Check if the lock is held. If not, error out and do not re-acquire.
       * Use this in cases where there are many waiters by default and re-acquire
       * is unlikely to succeed.
       *
       * @throws LockingException if we lost the ownership
       * @see #checkOwnershipAndReacquire()
       */
      void checkOwnership() throws LockingException;
  
  }
  