1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.transaction.locking;
18
19 /**
20 * A multi level lock. Depending on the implementation more than one owner may own a certain lock level on the same lock.
21 *
22 * @version $Id: MultiLevelLock.java 493628 2007-01-07 01:42:48Z joerg $
23 * @see LockManager
24 */
25 public interface MultiLevelLock {
26
27 /**
28 * Tries to acquire a certain lock level on this lock.
29 *
30 * @param ownerId a unique id identifying the entity that wants to acquire a certain lock level on this lock
31 * @param targetLockLevel the lock level to acquire
32 * @param wait <code>true</code> if this method shall block when the desired lock level can not be acquired
33 * @param reentrant <code>true</code> if lock levels of the same entity acquired earlier
34 * should not restrict compatibility with the lock level desired now
35 * @param timeoutMSecs if blocking is enabled by the <code>wait</code> parameter this specifies the maximum wait time in milliseconds
36 * @return <code>true</code> if the lock actually was acquired
37 * @throws InterruptedException when the thread waiting on this method is interrupted
38 */
39 public boolean acquire(Object ownerId, int targetLockLevel, boolean wait, boolean reentrant, long timeoutMSecs)
40 throws InterruptedException;
41
42 /**
43 * Releases any lock levels the specified owner may hold on this lock.
44 *
45 * @param ownerId a unique id identifying the entity that wants to release all lock levels
46 * @return <code>true</code> if the lock actually was released, <code>false</code> in case
47 * there was no lock held by the owner
48 */
49 public boolean release(Object ownerId);
50
51 /**
52 * Retuns the highest lock level the specified owner holds on this lock or <code>0</code> if it holds no locks at all.
53 *
54 * @param ownerId a unique id identifying the entity that wants to know its highest lock level
55 * @return the highest lock level
56 */
57 public int getLockLevel(Object ownerId);
58 }