1 //****************************************************************************** 2 // 3 // File: ShortMatrixBuf_1.java 4 // Package: edu.rit.mp.buf 5 // Unit: Class edu.rit.mp.buf.ShortMatrixBuf_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.ShortBuffer; 44 45 import edu.rit.mp.Buf; 46 import edu.rit.pj.reduction.Op; 47 import edu.rit.pj.reduction.ShortOp; 48 import edu.rit.util.Range; 49 50 /** 51 * Class ShortMatrixBuf_1 provides a buffer for a matrix of short items sent or 52 * received using the Message Protocol (MP). The matrix row and column strides 53 * must both be 1. While an instance of class ShortMatrixBuf_1 may be 54 * constructed directly, normally you will use a factory method in class 55 * {@linkplain edu.rit.mp.ShortBuf ShortBuf}. See that class for further 56 * information. 57 * 58 * @author Alan Kaminsky 59 * @version 05-Apr-2009 60 */ 61 public class ShortMatrixBuf_1 62 extends ShortMatrixBuf { 63 64 // Exported constructors. 65 /** 66 * Construct a new short matrix buffer. It is assumed that the rows and 67 * columns of <code>theMatrix</code> are allocated and that each row of 68 * <code>theMatrix</code> has the same number of columns. 69 * 70 * @param theMatrix Matrix. 71 * @param theRowRange Range of rows to include. The stride is assumed to be 72 * 1. 73 * @param theColRange Range of columns to include. The stride is assumed to 74 * be 1. 75 */ 76 public ShortMatrixBuf_1(short[][] theMatrix, 77 Range theRowRange, 78 Range theColRange) { 79 super(theMatrix, theRowRange, theColRange); 80 } 81 82 // Exported operations. 83 /** 84 * {@inheritDoc} 85 * 86 * Obtain the given item from this buffer. 87 * <P> 88 * The <code>get()</code> method must not block the calling thread; if it does, 89 * all message I/O in MP will be blocked. 90 */ 91 public short get(int i) { 92 return myMatrix[i2r(i) + myLowerRow][i2c(i) + myLowerCol]; 93 } 94 95 /** 96 * {@inheritDoc} 97 * 98 * Store the given item in this buffer. 99 * <P> 100 * The <code>put()</code> method must not block the calling thread; if it does, 101 * all message I/O in MP will be blocked. 102 */ 103 public void put(int i, 104 short item) { 105 myMatrix[i2r(i) + myLowerRow][i2c(i) + myLowerCol] = item; 106 } 107 108 /** 109 * {@inheritDoc} 110 * 111 * Create a buffer for performing parallel reduction using the given binary 112 * operation. The results of the reduction are placed into this buffer. 113 * @exception ClassCastException (unchecked exception) Thrown if this 114 * buffer's element data type and the given binary operation's argument data 115 * type are not the same. 116 */ 117 public Buf getReductionBuf(Op op) { 118 return new ShortMatrixReductionBuf_1(myMatrix, myRowRange, myColRange, (ShortOp) op); 119 } 120 121 // Hidden operations. 122 /** 123 * {@inheritDoc} 124 * 125 * Send as many items as possible from this buffer to the given byte buffer. 126 * <P> 127 * The <code>sendItems()</code> method must not block the calling thread; if it 128 * does, all message I/O in MP will be blocked. 129 */ 130 protected int sendItems(int i, 131 ByteBuffer buffer) { 132 ShortBuffer shortbuffer = buffer.asShortBuffer(); 133 int n = 0; 134 int r = i2r(i); 135 int row = r + myLowerRow; 136 int c = i2c(i); 137 int col = c + myLowerCol; 138 int ncols = Math.min(myColCount - c, shortbuffer.remaining()); 139 while (r < myRowCount && ncols > 0) { 140 shortbuffer.put(myMatrix[row], col, ncols); 141 n += ncols; 142 ++r; 143 ++row; 144 c = 0; 145 col = myLowerCol; 146 ncols = Math.min(myColCount, shortbuffer.remaining()); 147 } 148 buffer.position(buffer.position() + 2 * n); 149 return n; 150 } 151 152 /** 153 * {@inheritDoc} 154 * 155 * Receive as many items as possible from the given byte buffer to this 156 * buffer. 157 * <P> 158 * The <code>receiveItems()</code> method must not block the calling thread; if 159 * it does, all message I/O in MP will be blocked. 160 */ 161 protected int receiveItems(int i, 162 int num, 163 ByteBuffer buffer) { 164 ShortBuffer shortbuffer = buffer.asShortBuffer(); 165 num = Math.min(num, shortbuffer.remaining()); 166 int n = 0; 167 int r = i2r(i); 168 int row = r + myLowerRow; 169 int c = i2c(i); 170 int col = c + myLowerCol; 171 int ncols = Math.min(myColCount - c, num); 172 while (r < myRowCount && ncols > 0) { 173 shortbuffer.get(myMatrix[row], col, ncols); 174 num -= ncols; 175 n += ncols; 176 ++r; 177 ++row; 178 col = myLowerCol; 179 ncols = Math.min(myColCount, num); 180 } 181 buffer.position(buffer.position() + 2 * n); 182 return n; 183 } 184 185 }