1 //******************************************************************************
2 //
3 // File: ParallelConstruct.java
4 // Package: edu.rit.pj
5 // Unit: Class edu.rit.pj.ParallelConstruct
6 //
7 // This Java source file is copyright (C) 2007 by Alan Kaminsky. All rights
8 // reserved. For further information, contact the author, Alan Kaminsky, at
9 // ark@cs.rit.edu.
10 //
11 // This Java source file is part of the Parallel Java Library ("PJ"). PJ is free
12 // software; you can redistribute it and/or modify it under the terms of the GNU
13 // General Public License as published by the Free Software Foundation; either
14 // version 3 of the License, or (at your option) any later version.
15 //
16 // PJ is distributed in the hope that it will be useful, but WITHOUT ANY
17 // WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
18 // A PARTICULAR PURPOSE. See the GNU General Public License for more details.
19 //
20 // Linking this library statically or dynamically with other modules is making a
21 // combined work based on this library. Thus, the terms and conditions of the GNU
22 // General Public License cover the whole combination.
23 //
24 // As a special exception, the copyright holders of this library give you
25 // permission to link this library with independent modules to produce an
26 // executable, regardless of the license terms of these independent modules, and
27 // to copy and distribute the resulting executable under terms of your choice,
28 // provided that you also meet, for each linked independent module, the terms
29 // and conditions of the license of that module. An independent module is a module
30 // which is not derived from or based on this library. If you modify this library,
31 // you may extend this exception to your version of the library, but you are not
32 // obligated to do so. If you do not wish to do so, delete this exception
33 // statement from your version.
34 //
35 // A copy of the GNU General Public License is provided in the file gpl.txt. You
36 // may also obtain a copy of the GNU General Public License on the World Wide
37 // Web at http://www.gnu.org/licenses/gpl.html.
38 //
39 //******************************************************************************
40 package edu.rit.pj;
41
42 /**
43 * Class ParallelConstruct is the common base class for all parallel constructs
44 * that are executed by a {@linkplain ParallelTeam}.
45 *
46 * @author Alan Kaminsky
47 * @version 20-Dec-2007
48 */
49 public abstract class ParallelConstruct {
50
51 // Hidden data members.
52 // 128 bytes of extra padding to avert cache interference.
53 private long p0, p1, p2, p3, p4, p5, p6, p7;
54 private long p8, p9, pa, pb, pc, pd, pe, pf;
55
56 // Parallel team that is executing this parallel construct, or null if none.
57 ParallelTeam myTeam;
58
59 // Exported constructors.
60 /**
61 * Construct a new parallel construct.
62 */
63 public ParallelConstruct() {
64 }
65
66 // Exported operations.
67 /**
68 * Determine if a parallel team is executing this parallel construct.
69 *
70 * @return True if a parallel team is executing this parallel construct,
71 * false otherwise.
72 */
73 public final boolean isExecutingInParallel() {
74 return myTeam != null;
75 }
76
77 /**
78 * Returns the parallel team that is executing this parallel construct.
79 *
80 * @return Parallel team.
81 * @exception IllegalStateException (unchecked exception) Thrown if no
82 * parallel team is executing this parallel construct.
83 */
84 public final ParallelTeam team() {
85 if (myTeam == null) {
86 throw new IllegalStateException("ParallelConstruct.team(): No parallel team executing");
87 }
88 return myTeam;
89 }
90
91 /**
92 * Returns the parallel region of code within which a parallel team is
93 * executing this parallel construct.
94 *
95 * @return Parallel region.
96 * @exception IllegalStateException (unchecked exception) Thrown if no
97 * parallel team is executing this parallel construct.
98 */
99 public final ParallelRegion region() {
100 if (myTeam == null) {
101 throw new IllegalStateException("ParallelConstruct.region(): No parallel team executing");
102 }
103 return myTeam.myRegion;
104 }
105
106 /**
107 * Determine the number of threads in the parallel team executing this
108 * parallel construct.
109 *
110 * @return Number of threads in the thread team.
111 * @exception IllegalStateException (unchecked exception) Thrown if no
112 * parallel team is executing this parallel construct.
113 */
114 public final int getThreadCount() {
115 if (myTeam == null) {
116 throw new IllegalStateException("ParallelConstruct.getThreadCount(): No parallel team executing");
117 }
118 return myTeam.K;
119 }
120
121 /**
122 * Determine the index of the calling thread in the parallel team executing
123 * this parallel construct.
124 *
125 * @return Index of the calling thread in the range 0 ..
126 * <code>getThreadCount()-1</code>.
127 * @exception IllegalStateException (unchecked exception) Thrown if no
128 * parallel team is executing this parallel construct. Thrown if the thread
129 * calling
130 * <code>getThreadIndex()</code> is not part of the parallel team executing this
131 * parallel construct.
132 */
133 public final int getThreadIndex() {
134 return getCurrentThread().myIndex;
135 }
136
137 // Hidden operations.
138 /**
139 * Get the parallel team thread that is calling this method.
140 *
141 * @return Parallel team thread.
142 *
143 * @exception IllegalStateException (unchecked exception) Thrown if the
144 * calling thread is not one of the parallel team threads executing this
145 * parallel construct.
146 */
147 ParallelTeamThread getCurrentThread() {
148 if (myTeam == null) {
149 throw new IllegalStateException("ParallelConstruct.getCurrentThread(): No parallel team executing");
150 }
151 try {
152 ParallelTeamThread current = (ParallelTeamThread) Thread.currentThread();
153 if (current.myTeam != this.myTeam) {
154 throw new IllegalStateException("ParallelConstruct.getCurrentThread(): Current thread is not executing this parallel construct");
155 }
156 return current;
157 } catch (ClassCastException exc) {
158 throw new IllegalStateException("ParallelConstruct.getCurrentThread(): Current thread is not a parallel team thread",
159 exc);
160 }
161 }
162
163 }