diff -r fd16c54261b3 -r 90ce3da70b43 jdk/src/share/classes/java/awt/ActiveEvent.java --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/jdk/src/share/classes/java/awt/ActiveEvent.java Sat Dec 01 00:00:00 2007 +0000 @@ -0,0 +1,59 @@ +/* + * Copyright 1997-2002 Sun Microsystems, Inc. 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. Sun designates this + * particular file as subject to the "Classpath" exception as provided + * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, + * CA 95054 USA or visit www.sun.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 dispatch() method will be called when the event + * is dispatched, using the EventDispatchThread. + *

+ * 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 + * ActiveEvent 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. + *

+ * For security reasons, it is often desirable to use an ActiveEvent + * 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(); +}