1 //******************************************************************************
2 //
3 // File: SharedObjectArrayReductionBuf_1.java
4 // Package: edu.rit.mp.buf
5 // Unit: Class edu.rit.mp.buf.SharedObjectArrayReductionBuf_1
6 //
7 // This Java source file is copyright (C) 2012 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.mp.buf;
41
42 import edu.rit.mp.Buf;
43 import edu.rit.pj.reduction.ObjectOp;
44 import edu.rit.pj.reduction.Op;
45 import edu.rit.pj.reduction.SharedObjectArray;
46 import edu.rit.util.Range;
47
48 /**
49 * Class SharedObjectArrayReductionBuf_1 provides a reduction buffer for class
50 * {@linkplain SharedObjectArrayBuf_1}.
51 *
52 * @param <T> Data type of the objects in the buffer.
53 *
54 * @author Alan Kaminsky
55 * @version 01-Apr-2012
56 */
57 class SharedObjectArrayReductionBuf_1<T>
58 extends SharedObjectArrayBuf_1<T> {
59
60 // Hidden data members.
61 ObjectOp<T> myOp;
62 SharedObjectArrayBuf<T> myBuf;
63
64 // Exported constructors.
65 /**
66 * Construct a new shared object array reduction buffer.
67 *
68 * @param theArray Shared array.
69 * @param theRange Range of array elements to include in the buffer. The
70 * stride is assumed to be 1.
71 * @param op Binary operation.
72 * @param theBuf Underlying shared object array buffer.
73 * @exception NullPointerException (unchecked exception) Thrown if
74 * <code>op</code> is null.
75 */
76 public SharedObjectArrayReductionBuf_1(SharedObjectArray<T> theArray,
77 Range theRange,
78 ObjectOp<T> op,
79 SharedObjectArrayBuf<T> theBuf) {
80 super(theArray, theRange);
81 if (op == null) {
82 throw new NullPointerException("SharedObjectArrayReductionBuf_1(): op is null");
83 }
84 myOp = op;
85 myBuf = theBuf;
86 }
87
88 // Exported operations.
89 /**
90 * Store the given item in this buffer.
91 * <P>
92 * The <code>put()</code> method must not block the calling thread; if it does,
93 * all message I/O in MP will be blocked.
94 *
95 * @param i Item index in the range 0 .. <code>length()</code>-1.
96 * @param item Item to be stored at index <code>i</code>.
97 */
98 public void put(int i, T item) {
99 myArray.reduce(myArrayOffset + i, item, myOp);
100 reset();
101 myBuf.reset();
102 }
103
104 /**
105 * {@inheritDoc}
106 *
107 * Create a buffer for performing parallel reduction using the given binary
108 * operation. The results of the reduction are placed into this buffer.
109 * @exception ClassCastException (unchecked exception) Thrown if this
110 * buffer's element data type and the given binary operation's argument data
111 * type are not the same.
112 */
113 public Buf getReductionBuf(Op op) {
114 throw new UnsupportedOperationException();
115 }
116
117 }