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1   /**
2    * Copyright 2008 Atlassian Pty Ltd 
3    * 
4    * Licensed under the Apache License, Version 2.0 (the "License"); 
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at 
7    * 
8    *     http://www.apache.org/licenses/LICENSE-2.0 
9    * 
10   * Unless required by applicable law or agreed to in writing, software 
11   * distributed under the License is distributed on an "AS IS" BASIS, 
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 
13   * See the License for the specific language governing permissions and 
14   * limitations under the License.
15   */
16  
17  package com.atlassian.util.concurrent;
18  
19  import java.util.concurrent.Callable;
20  import java.util.concurrent.locks.ReadWriteLock;
21  
22  /**
23   * {@link LockManager} allows {@link Callable callables}, {@link Supplier
24   * suppliers} and {@link Runnable runnables} to be run under a lock that is
25   * resolved against an input object.
26   * 
27   * @param <T> The input type that we lock on.
28   * @deprecated use a {@link Function} that returns a {@link ManagedLock}
29   * instead.
30   */
31  @Deprecated
32  public interface LockManager<T> {
33  
34      /**
35       * Execute the supplied {@link Supplier} under a lock determined by the
36       * descriptor. Does not throw a checked exception.
37       * 
38       * @param <R> the result type
39       * @param descriptor to look up the lock
40       * @param supplier the operation to perform under lock
41       * @return whatever the supplied {@link Supplier} returns
42       */
43      <R> R withLock(final T descriptor, final Supplier<R> supplier);
44  
45      /**
46       * Execute the supplied {@link Callable} under a lock determined by the
47       * descriptor.
48       * 
49       * @param <R> the result type
50       * @param descriptor to look up the lock
51       * @param callable the operation to perform under lock
52       * @return whatever the supplied {@link Callable} returns
53       * @throws Exception if the supplied {@link Callable} throws an exception
54       */
55      <R> R withLock(final T descriptor, final Callable<R> callable) throws Exception;
56  
57      /**
58       * Execute the supplied {@link Runnable} under a lock determined by the
59       * descriptor.
60       * 
61       * @param descriptor to look up the lock
62       * @param runnable the operation to perform under lock
63       */
64      void withLock(final T descriptor, final Runnable runnable);
65  
66      /**
67       * Maintains two lock managers that internally use the same map of
68       * {@link ReadWriteLock read/write locks}
69       * 
70       * @param <T>
71       */
72      interface ReadWrite<T> {
73          /**
74           * For performing operations that require read locks
75           * 
76           * @return a lock manager that uses read locks
77           */
78          LockManager<T> read();
79  
80          /**
81           * For performing operations that require write locks
82           * 
83           * @return a lock manager that uses write locks
84           */
85          LockManager<T> write();
86      }
87  }