1 //****************************************************************************** 2 // 3 // File: LongArrayBuf_1.java 4 // Package: edu.rit.mp.buf 5 // Unit: Class edu.rit.mp.buf.LongArrayBuf_1 6 // 7 // This Java source file is copyright (C) 2007 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.LongBuffer; 44 45 import edu.rit.mp.Buf; 46 import edu.rit.pj.reduction.LongOp; 47 import edu.rit.pj.reduction.Op; 48 import edu.rit.util.Range; 49 50 /** 51 * Class LongArrayBuf_1 provides a buffer for an array of long items sent or 52 * received using the Message Protocol (MP). The array element stride must be 1. 53 * While an instance of class LongArrayBuf may be constructed directly, normally 54 * you will use a factory method in class {@linkplain 55 * edu.rit.mp.LongBuf LongBuf}. See that class for further information. 56 * 57 * @author Alan Kaminsky 58 * @version 25-Oct-2007 59 */ 60 public class LongArrayBuf_1 61 extends LongArrayBuf { 62 63 // Exported constructors. 64 /** 65 * Construct a new long array buffer. 66 * 67 * @param theArray Array. 68 * @param theRange Range of array elements to include in the buffer. The 69 * stride is assumed to be 1. 70 */ 71 public LongArrayBuf_1(long[] theArray, 72 Range theRange) { 73 super(theArray, theRange); 74 } 75 76 // Exported operations. 77 /** 78 * {@inheritDoc} 79 * 80 * Obtain the given item from this buffer. 81 * <P> 82 * The <code>get()</code> method must not block the calling thread; if it does, 83 * all message I/O in MP will be blocked. 84 */ 85 public long get(int i) { 86 return myArray[myArrayOffset + i]; 87 } 88 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 long item) { 99 myArray[myArrayOffset + i] = item; 100 } 101 102 /** 103 * {@inheritDoc} 104 * 105 * Create a buffer for performing parallel reduction using the given binary 106 * operation. The results of the reduction are placed into this buffer. 107 * @exception ClassCastException (unchecked exception) Thrown if this 108 * buffer's element data type and the given binary operation's argument data 109 * type are not the same. 110 */ 111 public Buf getReductionBuf(Op op) { 112 return new LongArrayReductionBuf_1(myArray, myRange, (LongOp) op); 113 } 114 115 // Hidden operations. 116 /** 117 * {@inheritDoc} 118 * 119 * Send as many items as possible from this buffer to the given byte buffer. 120 * <P> 121 * The <code>sendItems()</code> method must not block the calling thread; if it 122 * does, all message I/O in MP will be blocked. 123 */ 124 protected int sendItems(int i, 125 ByteBuffer buffer) { 126 LongBuffer longbuffer = buffer.asLongBuffer(); 127 int n = Math.min(myLength - i, longbuffer.remaining()); 128 longbuffer.put(myArray, myArrayOffset + i, n); 129 buffer.position(buffer.position() + 8 * n); 130 return n; 131 } 132 133 /** 134 * {@inheritDoc} 135 * 136 * Receive as many items as possible from the given byte buffer to this 137 * buffer. 138 * <P> 139 * The <code>receiveItems()</code> method must not block the calling thread; if 140 * it does, all message I/O in MP will be blocked. 141 */ 142 protected int receiveItems(int i, 143 int num, 144 ByteBuffer buffer) { 145 LongBuffer longbuffer = buffer.asLongBuffer(); 146 int n = Math.min(num, Math.min(myLength - i, longbuffer.remaining())); 147 longbuffer.get(myArray, myArrayOffset + i, n); 148 buffer.position(buffer.position() + 8 * n); 149 return n; 150 } 151 152 }