/*
 * Copyright (c) 2003 - 2009 Israfil Consulting Services Corporation
 * Copyright (c) 2003 - 2009 Christian Edward Gruber
 * All Rights Reserved
 * 
 * This software is licensed under the Berkeley Standard Distribution license,
 * (BSD license), as defined below:
 * 
 * Redistribution and use in source and binary forms, with or without 
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this 
 *    list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice, 
 *    this list of conditions and the following disclaimer in the documentation 
 *    and/or other materials provided with the distribution.
 * 3. Neither the name of Israfil Consulting Services nor the names of its contributors 
 *    may be used to endorse or promote products derived from this software without 
 *    specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND 
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 
 * IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, 
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, 
 * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 
 * OF SUCH DAMAGE.
 * 
 * $Id: Worker.java 401 2007-01-26 02:05:20Z cgruber $
 */
package net.israfil.foundation.concurrent;


/**
 * An object that wraps a Thread and performs units of work within that 
 * thread.  Very handy for concurrent development.
 * 
 * @author <a href="mailto:cgruber@israfil.net">Christian Edward Gruber </a>
 */
public interface Worker {
	

	
	//
	// SIGNALING
	//
	// TODO: Validate signaling.
	// TODO: Implement cleaner signaling.
	// 
	
	public boolean isRunning();
	
	public boolean isStopping();
	
	public boolean isStarting();
	
	public boolean isStopped();
	
	// Accessors
	
	public String getName();
	
	/**
	 * If the worker has stopped due to a thrown error, it should be captured
	 * and available via this method.  This method will throw an IllegalStateException
	 * if called when the worker is not in a Stopped state.
	 *
	 */
	public Throwable getError();
	
	/**
	 * Start the worker
	 * @return boolean Did the Worker startup properly.
	 */
	public boolean start();
	
	/**
	 * Attempts to gracefully shutdown the worker, but interrupts the
	 * thread after 20ms if the worker does not stop on its own.
	 * @throws InterruptedException
	 */
	public void stop() throws InterruptedException;
	
	/**
	 * Attempts to gracefully shutdown the worker, but interrupts the
	 * thread after a given timeout if the worker does not stop on its own.
	 * @throws InterruptedException
	 */
	public void stop(long timeout_miliseconds) throws InterruptedException;

	/**
	 * Attempts to gracefully shutdown the worker, but interrupts the
	 * thread after a given timeout if the worker does not stop on its own.
	 * @throws InterruptedException
	 */
	public void stop(long timeout_miliseconds,int timeout_nanoseconds) throws InterruptedException;
	
	public static enum WorkerState {
		Stopped,Starting,Running,Stopping
	}
}