2
|
1 |
/*
|
|
2 |
* Copyright 1997-2002 Sun Microsystems, Inc. All Rights Reserved.
|
|
3 |
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
|
|
4 |
*
|
|
5 |
* This code is free software; you can redistribute it and/or modify it
|
|
6 |
* under the terms of the GNU General Public License version 2 only, as
|
|
7 |
* published by the Free Software Foundation. Sun designates this
|
|
8 |
* particular file as subject to the "Classpath" exception as provided
|
|
9 |
* by Sun in the LICENSE file that accompanied this code.
|
|
10 |
*
|
|
11 |
* This code is distributed in the hope that it will be useful, but WITHOUT
|
|
12 |
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
|
13 |
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
|
|
14 |
* version 2 for more details (a copy is included in the LICENSE file that
|
|
15 |
* accompanied this code).
|
|
16 |
*
|
|
17 |
* You should have received a copy of the GNU General Public License version
|
|
18 |
* 2 along with this work; if not, write to the Free Software Foundation,
|
|
19 |
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
|
|
20 |
*
|
|
21 |
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
|
|
22 |
* CA 95054 USA or visit www.sun.com if you need additional information or
|
|
23 |
* have any questions.
|
|
24 |
*/
|
|
25 |
|
|
26 |
package java.awt;
|
|
27 |
|
|
28 |
/**
|
|
29 |
* An interface for events that know how to dispatch themselves.
|
|
30 |
* By implementing this interface an event can be placed upon the event
|
|
31 |
* queue and its <code>dispatch()</code> method will be called when the event
|
|
32 |
* is dispatched, using the <code>EventDispatchThread</code>.
|
|
33 |
* <p>
|
|
34 |
* This is a very useful mechanism for avoiding deadlocks. If
|
|
35 |
* a thread is executing in a critical section (i.e., it has entered
|
|
36 |
* one or more monitors), calling other synchronized code may
|
|
37 |
* cause deadlocks. To avoid the potential deadlocks, an
|
|
38 |
* <code>ActiveEvent</code> can be created to run the second section of
|
|
39 |
* code at later time. If there is contention on the monitor,
|
|
40 |
* the second thread will simply block until the first thread
|
|
41 |
* has finished its work and exited its monitors.
|
|
42 |
* <p>
|
|
43 |
* For security reasons, it is often desirable to use an <code>ActiveEvent</code>
|
|
44 |
* to avoid calling untrusted code from a critical thread. For
|
|
45 |
* instance, peer implementations can use this facility to avoid
|
|
46 |
* making calls into user code from a system thread. Doing so avoids
|
|
47 |
* potential deadlocks and denial-of-service attacks.
|
|
48 |
*
|
|
49 |
* @author Timothy Prinzing
|
|
50 |
* @since 1.2
|
|
51 |
*/
|
|
52 |
public interface ActiveEvent {
|
|
53 |
|
|
54 |
/**
|
|
55 |
* Dispatch the event to its target, listeners of the events source,
|
|
56 |
* or do whatever it is this event is supposed to do.
|
|
57 |
*/
|
|
58 |
public void dispatch();
|
|
59 |
}
|