WorkerTask.java

/*
 * Aphelion
 * Copyright (c) 2013  Joris van der Wel
 * 
 * This file is part of Aphelion
 * 
 * Aphelion is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, version 3 of the License.
 * 
 * Aphelion is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU Affero General Public License
 * along with Aphelion.  If not, see <http://www.gnu.org/licenses/>.
 * 
 * In addition, the following supplemental terms apply, based on section 7 of
 * the GNU Affero General Public License (version 3):
 * a) Preservation of all legal notices and author attributions
 * b) Prohibition of misrepresentation of the origin of this material, and
 * modified versions are required to be marked in reasonable ways as
 * different from the original version (for example by appending a copyright notice).
 * 
 * Linking this library statically or dynamically with other modules is making a
 * combined work based on this library. Thus, the terms and conditions of the
 * GNU Affero General Public License cover the whole combination.
 * 
 * As a special exception, the copyright holders of this library give you 
 * permission to link this library with independent modules to produce an 
 * executable, regardless of the license terms of these independent modules,
 * and to copy and distribute the resulting executable under terms of your 
 * choice, provided that you also meet, for each linked independent module,
 * the terms and conditions of the license of that module. An independent
 * module is a module which is not derived from or based on this library.
 */
package aphelion.shared.event;

import aphelion.shared.event.promise.AbstractPromise;
import aphelion.shared.event.promise.PromiseException;

/**
 *
 * @param <ARGUMENT> 
 * @param <RETURN> 
 * @author Joris
 */
public abstract class WorkerTask<ARGUMENT, RETURN>
{
        /** Execute your expensive work here.
         * Note: A worker task should not add more tasks on its own (Workable.addWorkerTask),
         * Use Workable.runOnMain first!
         * @param argument Same as the "argument" argument in Workable.addWorkerTask
         * @return Passed to AbstractPromise.resolve as argument "ret"
         * @throws aphelion.shared.event.promise.PromiseException 
         *         Passed to AbstractPromise.reject as argument "ex"
         */
        public abstract RETURN work(ARGUMENT argument) throws PromiseException;
        
        // Set by event loop
        ARGUMENT argument;
        AbstractPromise promise;
        
        // Set by worker thread
        PromiseException error;
        RETURN ret;
}