util/concurrent/Cancellable.java

/*
 * Written by Doug Lea with assistance from members of JCP JSR-166
 * Expert Group and released to the public domain. Use, modify, and
 * redistribute this code in any way without acknowledgement.
 */

package java.util.concurrent;

/**
 * An asynchronous task that can be cancelled.  Cancellation is performed by
 * the <tt>cancel</tt> method.  Additional methods are provided to determine
 * if the task completed normally or was cancelled.
 *
 * @since 1.5
 *
 * @spec JSR-166
 * @revised $Date: 2003/02/26 10:48:09 $
 * @editor $Author: jozart $
 */
public interface Cancellable {

    /**
     * Cancels execution of this task if it has not already completed.
     * If this task has not started when <tt>cancel</tt> is called, this
     * task will never run.  If the task has already started, then
     * the <tt>interruptIfRunning</tt> parameter determines whether the
     * thread executing this task should be interrupted in an attempt to
     * stop the task.
     *
     * @param interruptIfRunning <tt>true</tt> if the thread executing this
     * task should be interrupted; otherwise, in-progress tasks are allowed
     * to complete
     * @return <tt>true</tt> if task has not already completed or been
     * cancelled; <tt>false</tt> otherwise
     */
    boolean cancel(boolean mayInterruptIfRunning);

    /**
     * Returns <tt>true</tt> if this task was cancelled before it completed
     * normally.
     *
     * @return <tt>true</tt> if task was cancelled before it completed
     */
    boolean isCancelled();

    /**
     * Returns <tt>true</tt> if this task ran to completion or was cancelled.
     *
     * @return <tt>true</tt> if task completed normally or was cancelled
     */
    boolean isDone();
}
Revision:	1.2
Committed:	Tue May 27 18:14:39 2003 UTC (21 years ago) by dl
Branch:	MAIN
CVS Tags:	JSR166_PRERELEASE_0_1
Changes since 1.1:	+3 -1 lines
Log Message:	re-check-in initial implementations
#	User	Rev	Content
1	tim	1.1	/*
2	dl	1.2	* Written by Doug Lea with assistance from members of JCP JSR-166
3			* Expert Group and released to the public domain. Use, modify, and
4			* redistribute this code in any way without acknowledgement.
5	tim	1.1	*/
6
7			package java.util.concurrent;
8
9			/**
10			* An asynchronous task that can be cancelled. Cancellation is performed by
11			* the <tt>cancel</tt> method. Additional methods are provided to determine
12			* if the task completed normally or was cancelled.
13			*
14			* @since 1.5
15			*
16			* @spec JSR-166
17			* @revised $Date: 2003/02/26 10:48:09 $
18			* @editor $Author: jozart $
19			*/
20			public interface Cancellable {
21
22			/**
23			* Cancels execution of this task if it has not already completed.
24			* If this task has not started when <tt>cancel</tt> is called, this
25			* task will never run. If the task has already started, then
26			* the <tt>interruptIfRunning</tt> parameter determines whether the
27			* thread executing this task should be interrupted in an attempt to
28			* stop the task.
29			*
30			* @param interruptIfRunning <tt>true</tt> if the thread executing this
31			* task should be interrupted; otherwise, in-progress tasks are allowed
32			* to complete
33			* @return <tt>true</tt> if task has not already completed or been
34			* cancelled; <tt>false</tt> otherwise
35			*/
36			boolean cancel(boolean mayInterruptIfRunning);
37
38			/**
39			* Returns <tt>true</tt> if this task was cancelled before it completed
40			* normally.
41			*
42			* @return <tt>true</tt> if task was cancelled before it completed
43			*/
44			boolean isCancelled();
45
46			/**
47			* Returns <tt>true</tt> if this task ran to completion or was cancelled.
48			*
49			* @return <tt>true</tt> if task completed normally or was cancelled
50			*/
51			boolean isDone();
52			}