/* * @(#)ActiveEvent.java 1.9 06/10/10 * * Copyright 1990-2008 Sun Microsystems, Inc. All Rights Reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License version * 2 only, as published by the Free Software Foundation. * * This program 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 version 2 for more details (a copy is * included at /legal/license.txt). * * You should have received a copy of the GNU General Public License * version 2 along with this work; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA * 02110-1301 USA * * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa * Clara, CA 95054 or visit www.sun.com if you need additional * information or have any questions. * */ package java.awt; /** * An interface for events that know how dispatch themselves. * By implementing this interface an event can be placed upon the event * queue and its <code>dispatch()</code> method will be called when the event * is dispatched, using the <code>EventDispatchThread</code>. * <p> * This is a very useful mechanism for avoiding deadlocks. If * a thread is executing in a critical section (i.e., it has entered * one or more monitors), calling other synchronized code may * cause deadlocks. To avoid the potential deadlocks, an * <code>ActiveEvent</code> can be created to run the second section of * code at later time. If there is contention on the monitor, * the second thread will simply block until the first thread * has finished its work and exited its monitors. * <p> * For security reasons, it is often desirable to use an <code>ActiveEvent</code> * to avoid calling untrusted code from a critical thread. For * instance, peer implementations can use this facility to avoid * making calls into user code from a system thread. Doing so avoids * potential deadlocks and denial-of-service attacks. * * @author Timothy Prinzing * @version 1.9 02/02/00 * @since 1.2 */ public interface ActiveEvent { /** * Dispatch the event to it's target, listeners of the events source, * or do whatever it is this event is supposed to do. */ public void dispatch(); }