01: /* ====================================================================
02: The Jicarilla Software License
03:
04: Copyright (c) 2003 Leo Simons.
05: All rights reserved.
06:
07: Permission is hereby granted, free of charge, to any person obtaining
08: a copy of this software and associated documentation files (the
09: "Software"), to deal in the Software without restriction, including
10: without limitation the rights to use, copy, modify, merge, publish,
11: distribute, sublicense, and/or sell copies of the Software, and to
12: permit persons to whom the Software is furnished to do so, subject to
13: the following conditions:
14:
15: The above copyright notice and this permission notice shall be
16: included in all copies or substantial portions of the Software.
17:
18: THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
19: EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
20: MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
21: IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
22: CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
23: TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
24: SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
25: ==================================================================== */
26: package org.jicarilla.plumbing;
27:
28: import EDU.oswego.cs.dl.util.concurrent.Channel;
29:
30: /**
31: * <p>A Barrier Processor runs am enqueued message through
32: * several stages, <i>in its own thread</i>, before dequeueing it.
33: * In a diagram:</p>
34: *
35: * <pre>
36: * +-----------------------------------------------+
37: * |Barrierprocessor +------------+ |
38: * | ...................| Worker |... |
39: * | . . +------------+ . |
40: * | . . . . |
41: * put() |+---------+ +------+ +------+ +---------+ | take()
42: * ------>|Channel |->|Stage1|->|Stage2|->|Channel |------->
43: * |+---------+ +------+ +------+ +---------+ |
44: * +-----------------------------------------------+
45: * </pre>
46: *
47: * <p>Use a barrier processor if you need to shield stages that are
48: * not thread safe from receiving messages from multiple concurrent
49: * threads. Note a barrier processor may create a big bottleneck in
50: * your system. If this happens, you should consider redesigning
51: * your application so that you can either use multiple
52: * singlethreaded stages of the same type, or change those stages to
53: * be thread-safe. The former is usually the more performant option,
54: * but the latter may be easier (by using synchronization in the
55: * appropriate places in your code).</p>
56: *
57: * @author <a href="lsimons at jicarilla dot org">Leo Simons</a>
58: * @version $Id: BarrierProcessor.java,v 1.1 2004/03/22 21:20:13 lsimons Exp $
59: */
60: public class BarrierProcessor extends DefaultStage {
61: public BarrierProcessor(Channel channel, Sink errorHandler) {
62: super(channel, errorHandler);
63: }
64: }
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