1 //******************************************************************************
2 //
3 // File: Unsigned8BitIntegerMatrixReductionBuf.java
4 // Package: edu.rit.mp.buf
5 // Unit: Class edu.rit.mp.buf.Unsigned8BitIntegerMatrixReductionBuf
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
44 import edu.rit.mp.Buf;
45 import edu.rit.mp.Unsigned8BitIntegerBuf;
46 import edu.rit.pj.reduction.IntegerOp;
47 import edu.rit.pj.reduction.Op;
48 import edu.rit.pj.reduction.ReduceArrays;
49 import edu.rit.util.Range;
50
51 /**
52 * Class Unsigned8BitIntegerMatrixReductionBuf provides a reduction buffer for
53 * class {@linkplain Unsigned8BitIntegerMatrixBuf}.
54 *
55 * @author Alan Kaminsky
56 * @version 05-Apr-2009
57 */
58 class Unsigned8BitIntegerMatrixReductionBuf
59 extends Unsigned8BitIntegerMatrixBuf {
60
61 // Hidden data members.
62 IntegerOp myOp;
63
64 // Exported constructors.
65 /**
66 * Construct a new unsigned 8-bit integer matrix reduction buffer. It is
67 * assumed that the rows and columns of <code>theMatrix</code> are allocated and
68 * that each row of <code>theMatrix</code> has the same number of columns.
69 *
70 * @param theMatrix Matrix.
71 * @param theRowRange Range of rows to include.
72 * @param theColRange Range of columns to include.
73 * @param op Binary operation.
74 * @exception NullPointerException (unchecked exception) Thrown if
75 * <code>op</code> is null.
76 */
77 public Unsigned8BitIntegerMatrixReductionBuf(int[][] theMatrix,
78 Range theRowRange,
79 Range theColRange,
80 IntegerOp op) {
81 super(theMatrix, theRowRange, theColRange);
82 if (op == null) {
83 throw new NullPointerException("Unsigned8BitIntegerMatrixReductionBuf(): op is null");
84 }
85 myOp = op;
86 }
87
88 // Exported operations.
89 /**
90 * {@inheritDoc}
91 *
92 * Store the given item in this buffer.
93 * <P>
94 * The <code>put()</code> method must not block the calling thread; if it does,
95 * all message I/O in MP will be blocked.
96 */
97 public void put(int i,
98 int item) {
99 int row = (i / myColCount) * myRowStride + myLowerRow;
100 int col = (i % myColCount) * myColStride + myLowerCol;
101 myMatrix[row][col] = myOp.op(myMatrix[row][col], item);
102 }
103
104 /**
105 * {@inheritDoc}
106 *
107 * Copy items from the given buffer to this buffer. The number of items
108 * copied is this buffer's length or <code>theSrc</code>'s length, whichever is
109 * smaller. If <code>theSrc</code> is this buffer, the <code>copy()</code> method
110 * does nothing.
111 * @exception ClassCastException (unchecked exception) Thrown if
112 * <code>theSrc</code>'s item data type is not the same as this buffer's item
113 * data type.
114 */
115 public void copy(Buf theSrc) {
116 if (theSrc == this) {
117 } else if (theSrc instanceof Unsigned8BitIntegerMatrixBuf) {
118 Unsigned8BitIntegerMatrixBuf src
119 = (Unsigned8BitIntegerMatrixBuf) theSrc;
120 ReduceArrays.reduce(src.myMatrix, src.myRowRange, src.myColRange,
121 this.myMatrix, this.myRowRange, this.myColRange,
122 myOp);
123 } else {
124 Unsigned8BitIntegerBuf.defaultCopy((Unsigned8BitIntegerBuf) 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 num = Math.min(num, buffer.remaining());
155 int n = 0;
156 int r = i2r(i);
157 int row = r * myRowStride + myLowerRow;
158 int c = i2c(i);
159 int col = c * myColStride + myLowerCol;
160 int ncols = Math.min(myColCount - c, num);
161 while (r < myRowCount && ncols > 0) {
162 int[] myMatrix_row = myMatrix[row];
163 for (c = 0; c < ncols; ++c) {
164 myMatrix_row[col]
165 = myOp.op(myMatrix_row[col], buffer.get() & 0xFF);
166 col += myColStride;
167 }
168 num -= ncols;
169 n += ncols;
170 ++r;
171 row += myRowStride;
172 col = myLowerCol;
173 ncols = Math.min(myColCount, num);
174 }
175 return n;
176 }
177
178 }