jdk/src/share/classes/java/awt/ActiveEvent.java
author martin
Mon, 10 Mar 2008 14:32:51 -0700
changeset 48 dc5744ca15ea
parent 2 90ce3da70b43
child 5506 202f599c92aa
permissions -rw-r--r--
4960438: (process) Need IO redirection API for subprocesses Reviewed-by: alanb, iris
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/*
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 * Copyright 1997-2002 Sun Microsystems, Inc.  All Rights Reserved.
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 *
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 * This code is free software; you can redistribute it and/or modify it
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 * under the terms of the GNU General Public License version 2 only, as
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 * published by the Free Software Foundation.  Sun designates this
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 * particular file as subject to the "Classpath" exception as provided
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 * by Sun in the LICENSE file that accompanied this code.
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 *
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 * This code is distributed in the hope that it will be useful, but WITHOUT
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 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
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 * version 2 for more details (a copy is included in the LICENSE file that
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 * accompanied this code).
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 *
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 * You should have received a copy of the GNU General Public License version
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 * 2 along with this work; if not, write to the Free Software Foundation,
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 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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 *
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 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
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 * CA 95054 USA or visit www.sun.com if you need additional information or
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 * have any questions.
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 */
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package java.awt;
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/**
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 * An interface for events that know how to dispatch themselves.
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 * By implementing this interface an event can be placed upon the event
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 * queue and its <code>dispatch()</code> method will be called when the event
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 * is dispatched, using the <code>EventDispatchThread</code>.
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 * <p>
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 * This is a very useful mechanism for avoiding deadlocks. If
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 * a thread is executing in a critical section (i.e., it has entered
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 * one or more monitors), calling other synchronized code may
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 * cause deadlocks. To avoid the potential deadlocks, an
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 * <code>ActiveEvent</code> can be created to run the second section of
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 * code at later time. If there is contention on the monitor,
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 * the second thread will simply block until the first thread
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 * has finished its work and exited its monitors.
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 * <p>
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 * For security reasons, it is often desirable to use an <code>ActiveEvent</code>
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 * to avoid calling untrusted code from a critical thread. For
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 * instance, peer implementations can use this facility to avoid
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 * making calls into user code from a system thread. Doing so avoids
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 * potential deadlocks and denial-of-service attacks.
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 *
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 * @author  Timothy Prinzing
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 * @since   1.2
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 */
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public interface ActiveEvent {
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    /**
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     * Dispatch the event to its target, listeners of the events source,
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     * or do whatever it is this event is supposed to do.
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     */
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    public void dispatch();
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}