// NPCTE fix for bugId 4510777, esc 532372, MR October 2001
// file Task.java created for this bug fix
/* 
 * @(#)file      Task.java 
 * @(#)author    Sun Microsystems, Inc. 
 * @(#)version   1.2 
 * @(#)date      01/10/03 
 * 
 * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */ 
package com.sun.jmx.snmp.tasks;

/**
 * This interface is implemented by objects that can be executed
 * by a {@link com.sun.jmx.snmp.tasks.TaskServer}. 
 * <p>A <code>Task</code> object implements two methods:
 * <ul><li><code>public void run(): </code> from 
 *               {@link java.lang.Runnable}</li>
 * <ul>This method is called by the {@link com.sun.jmx.snmp.tasks.TaskServer}
 *     when the task is executed.</ul>
 * <li><code>public void cancel(): </code></li>
 * <ul>This method is called by the {@link com.sun.jmx.snmp.tasks.TaskServer}
 *     if the <code>TaskServer</code> is stopped before the 
 *     <code>Task</code> is executed.</ul>
 * </ul>
 * An implementation of {@link com.sun.jmx.snmp.tasks.TaskServer} shall call
 * either <code>run()</code> or <code>cancel()</code>.
 * Whether the task is executed synchronously in the current
 * thread (when calling <code>TaskServer.submitTask()</code> or in a new
 * thread dedicated to the task, or in a daemon thread, depends on the
 * implementation of the <code>TaskServer</code> through which the task
 * is executed. 
 * <p>The implementation of <code>Task</code> must not make any
 * assumption on the implementation of the <code>TaskServer</code> through
 * which it will be executed.
 * <p><b>This API is a Sun Microsystems internal API  and is subject 
 * to change without notice.</b></p>
 * @see com.sun.jmx.snmp.tasks.TaskServer
 *
 * @since 1.5
 **/
public interface Task extends Runnable {
    /**
     * Cancel the submitted task.
     * The implementation of this method is Task-implementation dependent.
     * It could involve some message logging, or even call the run() method.
     * Note that only one of run() or cancel() will be called - and exactly
     * one.
     **/
    public void cancel();
}