1 //******************************************************************************
2 //
3 // File: Unsigned16BitIntegerMatrixReductionBuf.java
4 // Package: edu.rit.mp.buf
5 // Unit: Class edu.rit.mp.buf.Unsigned16BitIntegerMatrixReductionBuf
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.ShortBuffer;
44
45 import edu.rit.mp.Buf;
46 import edu.rit.mp.Unsigned16BitIntegerBuf;
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 Unsigned16BitIntegerMatrixReductionBuf provides a reduction buffer for
54 * class {@linkplain Unsigned16BitIntegerMatrixBuf}.
55 *
56 * @author Alan Kaminsky
57 * @version 05-Apr-2009
58 */
59 class Unsigned16BitIntegerMatrixReductionBuf
60 extends Unsigned16BitIntegerMatrixBuf {
61
62 // Hidden data members.
63 IntegerOp myOp;
64
65 // Exported constructors.
66 /**
67 * Construct a new unsigned 16-bit integer matrix reduction buffer. It is
68 * assumed that the rows and columns of <code>theMatrix</code> are allocated and
69 * that each row of <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 Unsigned16BitIntegerMatrixReductionBuf(int[][] theMatrix,
79 Range theRowRange,
80 Range theColRange,
81 IntegerOp op) {
82 super(theMatrix, theRowRange, theColRange);
83 if (op == null) {
84 throw new NullPointerException("Unsigned16BitIntegerMatrixReductionBuf(): 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 int 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 Unsigned16BitIntegerMatrixBuf) {
119 Unsigned16BitIntegerMatrixBuf src
120 = (Unsigned16BitIntegerMatrixBuf) theSrc;
121 ReduceArrays.reduce(src.myMatrix, src.myRowRange, src.myColRange,
122 this.myMatrix, this.myRowRange, this.myColRange,
123 myOp);
124 } else {
125 Unsigned16BitIntegerBuf.defaultCopy((Unsigned16BitIntegerBuf) theSrc, this);
126 }
127 }
128
129 /**
130 * {@inheritDoc}
131 *
132 * Create a buffer for performing parallel reduction using the given binary
133 * operation. The results of the reduction are placed into this buffer.
134 * @exception ClassCastException (unchecked exception) Thrown if this
135 * buffer's element data type and the given binary operation's argument data
136 * type are not the same.
137 */
138 public Buf getReductionBuf(Op op) {
139 throw new UnsupportedOperationException();
140 }
141
142 // Hidden operations.
143 /**
144 * {@inheritDoc}
145 *
146 * Receive as many items as possible from the given byte buffer to this
147 * buffer.
148 * <P>
149 * The <code>receiveItems()</code> method must not block the calling thread; if
150 * it does, all message I/O in MP will be blocked.
151 */
152 protected int receiveItems(int i,
153 int num,
154 ByteBuffer buffer) {
155 ShortBuffer shortbuffer = buffer.asShortBuffer();
156 num = Math.min(num, shortbuffer.remaining());
157 int n = 0;
158 int r = i2r(i);
159 int row = r * myRowStride + myLowerRow;
160 int c = i2c(i);
161 int col = c * myColStride + myLowerCol;
162 int ncols = Math.min(myColCount - c, num);
163 while (r < myRowCount && ncols > 0) {
164 int[] myMatrix_row = myMatrix[row];
165 for (c = 0; c < ncols; ++c) {
166 myMatrix_row[col]
167 = myOp.op(myMatrix_row[col], shortbuffer.get()) & 0xFFFF;
168 col += myColStride;
169 }
170 num -= ncols;
171 n += ncols;
172 ++r;
173 row += myRowStride;
174 col = myLowerCol;
175 ncols = Math.min(myColCount, num);
176 }
177 buffer.position(buffer.position() + 2 * n);
178 return n;
179 }
180
181 }