2 * Copyright (c) 2005, Eric Crahen
4 * Permission is hereby granted, free of charge, to any person obtaining a copy
5 * of this software and associated documentation files (the "Software"), to deal
6 * in the Software without restriction, including without limitation the rights
7 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
8 * copies of the Software, and to permit persons to whom the Software is furnished
9 * to do so, subject to the following conditions:
11 * The above copyright notice and this permission notice shall be included in all
12 * copies or substantial portions of the Software.
14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
17 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
18 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
19 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
23 #ifndef __ZTCANCELABLE_H__
24 #define __ZTCANCELABLE_H__
26 #include "zthread/Exceptions.h"
33 * @author Eric Crahen <http://www.code-foo.com>
34 * @date <2003-07-16T09:28:46-0400>
37 * The Cancelable interface defines a common method of adding general <i>disable-and-exit</i>
38 * semantics to some object. By cancel()ing a Cancelable object, a request is
39 * made to disable that object.
43 * A cancel()ed object may not necessarily abort it work immediately. Often, it much more
44 * elegant for a cancel()ed object to complete handling whatever responsibilities have
45 * been assigned to it, but it will <i>not</i> take on any new responsibility.
49 * A cancel()ed should complete its responsibilities as soon as possible.
50 * Canceling is not only a request to stop taking on new responsibility, and to
51 * complete its current responsibility. Its also a request to complete dealing with its
52 * current responsibilities, quickly when possible.
57 //! Destroy a Cancelable object.
58 virtual ~Cancelable() {}
61 * Canceling a Cancelable object makes a request to disable that object.
62 * This entails refusing to take on any new responsibility, and completing
63 * its current responsibilities quickly.
65 * Canceling an object more than once has no effect.
67 * @post The Cancelable object will have permanently transitioned to a
68 * disabled state; it will now refuse to accept new responsibility.
70 virtual void cancel() = 0;
73 * Determine if a Cancelable object has been canceled.
76 * - <em>true</em> if cancel() was called prior to this function.
77 * - <em>false</em> otherwise.
79 virtual bool isCanceled() = 0;
84 } // namespace ZThread
86 #endif // __ZTCANCELABLE_H__