1 //******************************************************************************
2 //
3 // File: ObjectMatrixReductionBuf.java
4 // Package: edu.rit.mp.buf
5 // Unit: Class edu.rit.mp.buf.ObjectMatrixReductionBuf
6 //
7 // This Java source file is copyright (C) 2009 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.mp.ObjectBuf;
44 import edu.rit.pj.reduction.ObjectOp;
45 import edu.rit.pj.reduction.Op;
46 import edu.rit.pj.reduction.ReduceArrays;
47 import edu.rit.util.Range;
48
49 /**
50 * Class ObjectMatrixReductionBuf provides a reduction buffer for class
51 * {@linkplain ObjectMatrixBuf}.
52 *
53 * @param <T> Data type of the objects in the buffer.
54 *
55 * @author Alan Kaminsky
56 * @version 05-Apr-2009
57 */
58 @SuppressWarnings("unchecked")
59 class ObjectMatrixReductionBuf<T>
60 extends ObjectMatrixBuf<T> {
61
62 // Hidden data members.
63 ObjectOp<T> myOp;
64 ObjectMatrixBuf<T> myBuf;
65
66 // Exported constructors.
67 /**
68 * Construct a new object matrix reduction buffer. It is assumed that the
69 * rows and columns of <code>theMatrix</code> are allocated and that each row of
70 * <code>theMatrix</code> has the same number of columns.
71 *
72 * @param theMatrix Matrix.
73 * @param theRowRange Range of rows to include.
74 * @param theColRange Range of columns to include.
75 * @param op Binary operation.
76 * @param theBuf Underlying object matrix buffer.
77 * @exception NullPointerException (unchecked exception) Thrown if
78 * <code>op</code> is null.
79 */
80 public ObjectMatrixReductionBuf(T[][] theMatrix,
81 Range theRowRange,
82 Range theColRange,
83 ObjectOp<T> op,
84 ObjectMatrixBuf<T> theBuf) {
85 super(theMatrix, theRowRange, theColRange);
86 if (op == null) {
87 throw new NullPointerException("ObjectMatrixReductionBuf(): op is null");
88 }
89 myOp = op;
90 myBuf = theBuf;
91 }
92
93 // Exported operations.
94 /**
95 * Store the given item in this buffer.
96 * <P>
97 * The <code>put()</code> method must not block the calling thread; if it does,
98 * all message I/O in MP will be blocked.
99 *
100 * @param i Item index in the range 0 .. <code>length()</code>-1.
101 * @param item Item to be stored at index <code>i</code>.
102 */
103 public void put(int i, T item) {
104 int row = i2r(i) * myRowStride + myLowerRow;
105 int col = i2c(i) * myColStride + myLowerCol;
106 myMatrix[row][col] = myOp.op(myMatrix[row][col], item);
107 reset();
108 myBuf.reset();
109 }
110
111 /**
112 * {@inheritDoc}
113 *
114 * Copy items from the given buffer to this buffer. The number of items
115 * copied is this buffer's length or <code>theSrc</code>'s length, whichever is
116 * smaller. If <code>theSrc</code> is this buffer, the <code>copy()</code> method
117 * does nothing.
118 * @exception ClassCastException (unchecked exception) Thrown if
119 * <code>theSrc</code>'s item data type is not the same as this buffer's item
120 * data type.
121 */
122 public void copy(Buf theSrc) {
123 if (theSrc == this) {
124 } else if (theSrc instanceof ObjectMatrixBuf) {
125 ObjectMatrixBuf<T> src = (ObjectMatrixBuf<T>) theSrc;
126 ReduceArrays.reduce(src.myMatrix, src.myRowRange, src.myColRange,
127 this.myMatrix, this.myRowRange, this.myColRange,
128 myOp);
129 reset();
130 myBuf.reset();
131 } else {
132 ObjectBuf.defaultCopy((ObjectBuf<T>) theSrc, this);
133 reset();
134 myBuf.reset();
135 }
136 }
137
138 /**
139 * {@inheritDoc}
140 *
141 * Create a buffer for performing parallel reduction using the given binary
142 * operation. The results of the reduction are placed into this buffer.
143 * @exception ClassCastException (unchecked exception) Thrown if this
144 * buffer's element data type and the given binary operation's argument data
145 * type are not the same.
146 */
147 public Buf getReductionBuf(Op op) {
148 throw new UnsupportedOperationException();
149 }
150
151 }