| /** |
| * 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 com.twitter.distributedlog.lock; |
| |
| import com.twitter.distributedlog.exceptions.LockingException; |
| import com.twitter.distributedlog.io.AsyncCloseable; |
| import com.twitter.util.Future; |
| |
| /** |
| * Interface for distributed locking |
| */ |
| public interface DistributedLock extends AsyncCloseable { |
| |
| /** |
| * Asynchronously acquire the lock. |
| * |
| * @return future represents the acquire result. |
| */ |
| Future<? 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; |
| |
| } |