/interpreter/tags/at2dist041108/src/edu/vub/at/actors/eventloops/Future.java

 1/**
 2 * AmbientTalk/2 Project
 3 * Future.java created on 27-dec-2006 at 15:57:34
 4 * (c) Programming Technology Lab, 2006 - 2007
 5 * Authors: Tom Van Cutsem & Stijn Mostinckx
 6 * 
 7 * Permission is hereby granted, free of charge, to any person
 8 * obtaining a copy of this software and associated documentation
 9 * files (the "Software"), to deal in the Software without
10 * restriction, including without limitation the rights to use,
11 * copy, modify, merge, publish, distribute, sublicense, and/or
12 * sell copies of the Software, and to permit persons to whom the
13 * Software is furnished to do so, subject to the following
14 * conditions:
15 *
16 * The above copyright notice and this permission notice shall be
17 * included in all copies or substantial portions of the Software.
18 *
19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
20 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
21 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
22 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
23 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
24 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
25 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
26 * OTHER DEALINGS IN THE SOFTWARE.
27 */
28package edu.vub.at.actors.eventloops;
29
30/**
31 * A future is a placeholder for a 'return value' that is not yet computed.
32 * 
33 * A future can either be resolved into a value or it can be ruined by an exception.
34 * 
35 * @author tvcutsem
36 */
37public interface Future {
38	
39	/**
40	 * Used to resolve the future into the given result object.
41	 * This will notify any threads waiting for the value.
42	 */
43	public void resolve(Object result);
44	
45	/**
46	 * Used to ruin the future with the given exception.
47	 * This will notify any threads waiting for the value.
48	 */
49	public void ruin(Exception exception);
50	
51	/**
52	 * Used to retrieve the real value from the future.
53	 * @return the resolved value of the future, once it is available.
54	 * @throws Exception if the future has been ruined with an exception.
55	 */
56	public Object get() throws Exception;
57
58}