1 /*
2 * Copyright (C) 2010, Google Inc.
3 * and other copyright owners as documented in the project's IP log.
4 *
5 * This program and the accompanying materials are made available
6 * under the terms of the Eclipse Distribution License v1.0 which
7 * accompanies this distribution, is reproduced below, and is
8 * available at http://www.eclipse.org/org/documents/edl-v10.php
9 *
10 * All rights reserved.
11 *
12 * Redistribution and use in source and binary forms, with or
13 * without modification, are permitted provided that the following
14 * conditions are met:
15 *
16 * - Redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer.
18 *
19 * - Redistributions in binary form must reproduce the above
20 * copyright notice, this list of conditions and the following
21 * disclaimer in the documentation and/or other materials provided
22 * with the distribution.
23 *
24 * - Neither the name of the Eclipse Foundation, Inc. nor the
25 * names of its contributors may be used to endorse or promote
26 * products derived from this software without specific prior
27 * written permission.
28 *
29 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
30 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
31 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
32 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
33 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
34 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
35 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
36 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
37 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
38 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
40 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
41 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
42 */
43
44 package org.eclipse.jgit.lib;
45
46 /**
47 * Asynchronous operation handle.
48 *
49 * Callers that start an asynchronous operation are supplied with a handle that
50 * may be used to attempt cancellation of the operation if the caller does not
51 * wish to continue.
52 */
53 public interface AsyncOperation {
54 /**
55 * Cancels the running task.
56 *
57 * Attempts to cancel execution of this task. This attempt will fail if the
58 * task has already completed, already been cancelled, or could not be
59 * cancelled for some other reason. If successful, and this task has not
60 * started when cancel is called, this task should never run. If the task
61 * has already started, then the mayInterruptIfRunning parameter determines
62 * whether the thread executing this task should be interrupted in an
63 * attempt to stop the task.
64 *
65 * @param mayInterruptIfRunning
66 * true if the thread executing this task should be interrupted;
67 * otherwise, in-progress tasks are allowed to complete
68 * @return false if the task could not be cancelled, typically because it
69 * has already completed normally; true otherwise
70 */
71 public boolean cancel(boolean mayInterruptIfRunning);
72
73 /**
74 * Release resources used by the operation, including cancellation.
75 */
76 public void release();
77 }