1 //******************************************************************************
2 //
3 // File: FloatMatrixReductionBuf.java
4 // Package: edu.rit.mp.buf
5 // Unit: Class edu.rit.mp.buf.FloatMatrixReductionBuf
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 java.nio.ByteBuffer;
43 import java.nio.FloatBuffer;
44
45 import edu.rit.mp.Buf;
46 import edu.rit.mp.FloatBuf;
47 import edu.rit.pj.reduction.FloatOp;
48 import edu.rit.pj.reduction.Op;
49 import edu.rit.pj.reduction.ReduceArrays;
50 import edu.rit.util.Range;
51
52 /**
53 * Class FloatMatrixReductionBuf provides a reduction buffer for class
54 * {@linkplain FloatMatrixBuf}.
55 *
56 * @author Alan Kaminsky
57 * @version 05-Apr-2009
58 */
59 class FloatMatrixReductionBuf
60 extends FloatMatrixBuf {
61
62 // Hidden data members.
63 FloatOp myOp;
64
65 // Exported constructors.
66 /**
67 * Construct a new float matrix reduction buffer. It is assumed that the
68 * rows and columns of <code>theMatrix</code> are allocated and that each row of
69 * <code>theMatrix</code> has the same number of columns.
70 *
71 * @param theMatrix Matrix.
72 * @param theRowRange Range of rows to include.
73 * @param theColRange Range of columns to include.
74 * @param op Binary operation.
75 * @exception NullPointerException (unchecked exception) Thrown if
76 * <code>op</code> is null.
77 */
78 public FloatMatrixReductionBuf(float[][] theMatrix,
79 Range theRowRange,
80 Range theColRange,
81 FloatOp op) {
82 super(theMatrix, theRowRange, theColRange);
83 if (op == null) {
84 throw new NullPointerException("FloatMatrixReductionBuf(): op is null");
85 }
86 myOp = op;
87 }
88
89 // Exported operations.
90 /**
91 * {@inheritDoc}
92 *
93 * Store the given item in this buffer.
94 * <P>
95 * The <code>put()</code> method must not block the calling thread; if it does,
96 * all message I/O in MP will be blocked.
97 */
98 public void put(int i,
99 float item) {
100 int row = (i / myColCount) * myRowStride + myLowerRow;
101 int col = (i % myColCount) * myColStride + myLowerCol;
102 myMatrix[row][col] = myOp.op(myMatrix[row][col], item);
103 }
104
105 /**
106 * {@inheritDoc}
107 *
108 * Copy items from the given buffer to this buffer. The number of items
109 * copied is this buffer's length or <code>theSrc</code>'s length, whichever is
110 * smaller. If <code>theSrc</code> is this buffer, the <code>copy()</code> method
111 * does nothing.
112 * @exception ClassCastException (unchecked exception) Thrown if
113 * <code>theSrc</code>'s item data type is not the same as this buffer's item
114 * data type.
115 */
116 public void copy(Buf theSrc) {
117 if (theSrc == this) {
118 } else if (theSrc instanceof FloatMatrixBuf) {
119 FloatMatrixBuf src = (FloatMatrixBuf) theSrc;
120 ReduceArrays.reduce(src.myMatrix, src.myRowRange, src.myColRange,
121 this.myMatrix, this.myRowRange, this.myColRange,
122 myOp);
123 } else {
124 FloatBuf.defaultCopy((FloatBuf) theSrc, this);
125 }
126 }
127
128 /**
129 * {@inheritDoc}
130 *
131 * Create a buffer for performing parallel reduction using the given binary
132 * operation. The results of the reduction are placed into this buffer.
133 * @exception ClassCastException (unchecked exception) Thrown if this
134 * buffer's element data type and the given binary operation's argument data
135 * type are not the same.
136 */
137 public Buf getReductionBuf(Op op) {
138 throw new UnsupportedOperationException();
139 }
140
141 // Hidden operations.
142 /**
143 * {@inheritDoc}
144 *
145 * Receive as many items as possible from the given byte buffer to this
146 * buffer.
147 * <P>
148 * The <code>receiveItems()</code> method must not block the calling thread; if
149 * it does, all message I/O in MP will be blocked.
150 */
151 protected int receiveItems(int i,
152 int num,
153 ByteBuffer buffer) {
154 FloatBuffer floatbuffer = buffer.asFloatBuffer();
155 num = Math.min(num, floatbuffer.remaining());
156 int n = 0;
157 int r = i2r(i);
158 int row = r * myRowStride + myLowerRow;
159 int c = i2c(i);
160 int col = c * myColStride + myLowerCol;
161 int ncols = Math.min(myColCount - c, num);
162 while (r < myRowCount && ncols > 0) {
163 float[] myMatrix_row = myMatrix[row];
164 for (c = 0; c < ncols; ++c) {
165 myMatrix_row[col]
166 = myOp.op(myMatrix_row[col], floatbuffer.get());
167 col += myColStride;
168 }
169 num -= ncols;
170 n += ncols;
171 ++r;
172 row += myRowStride;
173 col = myLowerCol;
174 ncols = Math.min(myColCount, num);
175 }
176 buffer.position(buffer.position() + 4 * n);
177 return n;
178 }
179
180 }