/* * Copyright (c) 1997, 2002, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code 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. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code 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 in the LICENSE file that * accompanied this code). * * 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package java.awt; /** * An interface for events that know how to 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 * @since 1.2 */ public interface ActiveEvent { /** * Dispatch the event to its target, listeners of the events source, * or do whatever it is this event is supposed to do. */ public void dispatch(); }