01: /*--
02:
03: Copyright (C) 2002-2005 Adrian Price.
04: All rights reserved.
05:
06: Redistribution and use in source and binary forms, with or without
07: modification, are permitted provided that the following conditions
08: are met:
09:
10: 1. Redistributions of source code must retain the above copyright
11: notice, this list of conditions, and the following disclaimer.
12:
13: 2. Redistributions in binary form must reproduce the above copyright
14: notice, this list of conditions, and the disclaimer that follows
15: these conditions in the documentation and/or other materials
16: provided with the distribution.
17:
18: 3. The names "OBE" and "Open Business Engine" must not be used to
19: endorse or promote products derived from this software without prior
20: written permission. For written permission, please contact
21: adrianprice@sourceforge.net.
22:
23: 4. Products derived from this software may not be called "OBE" or
24: "Open Business Engine", nor may "OBE" or "Open Business Engine"
25: appear in their name, without prior written permission from
26: Adrian Price (adrianprice@users.sourceforge.net).
27:
28: THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
29: WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
30: OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
31: DISCLAIMED. IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT,
32: INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
33: (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
34: SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35: HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
36: STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
37: IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
38: POSSIBILITY OF SUCH DAMAGE.
39:
40: For more information on OBE, please see
41: <http://obe.sourceforge.net/>.
42:
43: */
44:
45: package org.obe.spi.model;
46:
47: /**
48: * Implements the logic and state of an XOR-JOIN instance.
49: *
50: * @author Adrian Price
51: */
52: public final class OrJoinInstance extends JoinInstance {
53: private static final long serialVersionUID = 8542861376795573396L;
54:
55: /**
56: * Constructs a new XOR-join instance.
57: *
58: * @param transitions IDs of afferent transitions.
59: */
60: public OrJoinInstance(String[] transitions) {
61: super (transitions);
62: }
63:
64: /**
65: * Handles the activation of an afferent transition. An XOR-join fires as
66: * soon as one its afferent transitions has fired; subsequent activations
67: * of any of the transitions are ignored until the join is {@link #reset}.
68: *
69: * @param transitionId The ID of the transition that fired.
70: * @return <code>true</code> if the join fired.
71: */
72: public synchronized boolean shouldFire(String transitionId) {
73: // Only fire once until reset.
74: boolean fire = false;
75: if (!hasFired()) {
76: for (int i = 0; i < _transitions.length; i++) {
77: if (_transitions[i].equals(transitionId)) {
78: if (didFire(i)) {
79: fire();
80: fire = true;
81: }
82: break;
83: }
84: }
85: }
86: return fire;
87: }
88: }
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