| /* |
| * 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.lucene.store; |
| |
| |
| import java.io.Closeable; |
| import java.io.IOException; |
| |
| /** An interprocess mutex lock. |
| * <p>Typical use might look like:<pre class="prettyprint"> |
| * try (final Lock lock = directory.obtainLock("my.lock")) { |
| * // ... code to execute while locked ... |
| * } |
| * </pre> |
| * |
| * @see Directory#obtainLock(String) |
| * |
| * @lucene.internal |
| */ |
| public abstract class Lock implements Closeable { |
| |
| /** |
| * Releases exclusive access. |
| * <p> |
| * Note that exceptions thrown from close may require |
| * human intervention, as it may mean the lock was no |
| * longer valid, or that fs permissions prevent removal |
| * of the lock file, or other reasons. |
| * <p> |
| * {@inheritDoc} |
| * @throws LockReleaseFailedException optional specific exception) if |
| * the lock could not be properly released. |
| */ |
| public abstract void close() throws IOException; |
| |
| /** |
| * Best effort check that this lock is still valid. Locks |
| * could become invalidated externally for a number of reasons, |
| * for example if a user deletes the lock file manually or |
| * when a network filesystem is in use. |
| * @throws IOException if the lock is no longer valid. |
| */ |
| public abstract void ensureValid() throws IOException; |
| } |