1 //******************************************************************************
2 //
3 // File: IntegerMatrixReductionBuf_1.java
4 // Package: edu.rit.mp.buf
5 // Unit: Class edu.rit.mp.buf.IntegerMatrixReductionBuf_1
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.IntBuffer;
44
45 import edu.rit.mp.Buf;
46 import edu.rit.mp.IntegerBuf;
47 import edu.rit.pj.reduction.IntegerOp;
48 import edu.rit.pj.reduction.Op;
49 import edu.rit.pj.reduction.ReduceArrays;
50 import edu.rit.util.Range;
51
52 /**
53 * Class IntegerMatrixReductionBuf_1 provides a reduction buffer for class
54 * {@linkplain IntegerMatrixBuf_1}.
55 *
56 * @author Alan Kaminsky
57 * @version 05-Apr-2009
58 */
59 class IntegerMatrixReductionBuf_1
60 extends IntegerMatrixBuf_1 {
61
62 // Hidden data members.
63 IntegerOp myOp;
64
65 // Exported constructors.
66 /**
67 * Construct a new integer 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. The stride is assumed to be
73 * 1.
74 * @param theColRange Range of columns to include. The stride is assumed to
75 * be 1.
76 * @param op Binary operation.
77 * @exception NullPointerException (unchecked exception) Thrown if
78 * <code>op</code> is null.
79 */
80 public IntegerMatrixReductionBuf_1(int[][] theMatrix,
81 Range theRowRange,
82 Range theColRange,
83 IntegerOp op) {
84 super(theMatrix, theRowRange, theColRange);
85 if (op == null) {
86 throw new NullPointerException("IntegerMatrixReductionBuf_1(): op is null");
87 }
88 myOp = op;
89 }
90
91 // Exported operations.
92 /**
93 * {@inheritDoc}
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 public void put(int i,
101 int item) {
102 int row = (i / myColCount) + myLowerRow;
103 int col = (i % myColCount) + myLowerCol;
104 myMatrix[row][col] = myOp.op(myMatrix[row][col], item);
105 }
106
107 /**
108 * {@inheritDoc}
109 *
110 * Copy items from the given buffer to this buffer. The number of items
111 * copied is this buffer's length or <code>theSrc</code>'s length, whichever is
112 * smaller. If <code>theSrc</code> is this buffer, the <code>copy()</code> method
113 * does nothing.
114 * @exception ClassCastException (unchecked exception) Thrown if
115 * <code>theSrc</code>'s item data type is not the same as this buffer's item
116 * data type.
117 */
118 public void copy(Buf theSrc) {
119 if (theSrc == this) {
120 } else if (theSrc instanceof IntegerMatrixBuf) {
121 IntegerMatrixBuf src = (IntegerMatrixBuf) theSrc;
122 ReduceArrays.reduce(src.myMatrix, src.myRowRange, src.myColRange,
123 this.myMatrix, this.myRowRange, this.myColRange,
124 myOp);
125 } else {
126 IntegerBuf.defaultCopy((IntegerBuf) theSrc, this);
127 }
128 }
129
130 /**
131 * {@inheritDoc}
132 *
133 * Create a buffer for performing parallel reduction using the given binary
134 * operation. The results of the reduction are placed into this buffer.
135 * @exception ClassCastException (unchecked exception) Thrown if this
136 * buffer's element data type and the given binary operation's argument data
137 * type are not the same.
138 */
139 public Buf getReductionBuf(Op op) {
140 throw new UnsupportedOperationException();
141 }
142
143 // Hidden operations.
144 /**
145 * {@inheritDoc}
146 *
147 * Receive as many items as possible from the given byte buffer to this
148 * buffer.
149 * <P>
150 * The <code>receiveItems()</code> method must not block the calling thread; if
151 * it does, all message I/O in MP will be blocked.
152 */
153 protected int receiveItems(int i,
154 int num,
155 ByteBuffer buffer) {
156 IntBuffer intbuffer = buffer.asIntBuffer();
157 num = Math.min(num, intbuffer.remaining());
158 int n = 0;
159 int r = i2r(i);
160 int row = r + myLowerRow;
161 int c = i2c(i);
162 int col = c + myLowerCol;
163 int ncols = Math.min(myColCount - c, num);
164 while (r < myRowCount && ncols > 0) {
165 int[] myMatrix_row = myMatrix[row];
166 for (c = 0; c < ncols; ++c) {
167 myMatrix_row[col]
168 = myOp.op(myMatrix_row[col], intbuffer.get());
169 ++col;
170 }
171 num -= ncols;
172 n += ncols;
173 ++r;
174 ++row;
175 col = myLowerCol;
176 ncols = Math.min(myColCount, num);
177 }
178 buffer.position(buffer.position() + 4 * n);
179 return n;
180 }
181
182 }