| 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 |
*/ |
| 6 |
|
| 7 |
package java.util.concurrent; |
| 8 |
|
| 9 |
/** |
| 10 |
* Something, usually a task, that can be cancelled. Cancellation is |
| 11 |
* performed by the <tt>cancel</tt> method. Additional methods are |
| 12 |
* provided to determine if the task completed normally or was |
| 13 |
* cancelled. |
| 14 |
* |
| 15 |
* @since 1.5 |
| 16 |
* |
| 17 |
* @spec JSR-166 |
| 18 |
* @revised $Date: 2003/06/21 12:23:28 $ |
| 19 |
* @editor $Author: dl $ |
| 20 |
* @see FutureTask |
| 21 |
* @see Executor |
| 22 |
*/ |
| 23 |
public interface Cancellable { |
| 24 |
|
| 25 |
/** |
| 26 |
* Attempt to cancel execution of this task. This attempt will |
| 27 |
* fail if the task has already completed, already been cancelled, or could not be |
| 28 |
* cancelled for some other reason. If successful, and this task |
| 29 |
* has not started when <tt>cancel</tt> is called, this task will |
| 30 |
* never run. If the task has already started, then the |
| 31 |
* <tt>interruptIfRunning</tt> parameter determines whether the |
| 32 |
* thread executing this task should be interrupted in an attempt |
| 33 |
* to stop the task. |
| 34 |
* |
| 35 |
* @param mayInterruptIfRunning <tt>true</tt> if the thread executing this |
| 36 |
* task should be interrupted; otherwise, in-progress tasks are allowed |
| 37 |
* to complete |
| 38 |
* @return <tt>false</tt> if the task could not be cancelled, |
| 39 |
* typically because is has already completed normally; |
| 40 |
* <tt>true</tt> otherwise |
| 41 |
*/ |
| 42 |
boolean cancel(boolean mayInterruptIfRunning); |
| 43 |
|
| 44 |
/** |
| 45 |
* Returns <tt>true</tt> if this task was cancelled before it completed |
| 46 |
* normally. |
| 47 |
* |
| 48 |
* @return <tt>true</tt> if task was cancelled before it completed |
| 49 |
*/ |
| 50 |
boolean isCancelled(); |
| 51 |
|
| 52 |
/** |
| 53 |
* Returns <tt>true</tt> if this task ran to completion or was cancelled. |
| 54 |
* |
| 55 |
* @return <tt>true</tt> if task completed normally or was cancelled |
| 56 |
*/ |
| 57 |
boolean isDone(); |
| 58 |
} |
