1 //****************************************************************************** 2 // 3 // File: SharedUnsigned16BitIntegerArrayBuf_1.java 4 // Package: edu.rit.mp.buf 5 // Unit: Class edu.rit.mp.buf.SharedUnsigned16BitIntegerArrayBuf_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 44 import edu.rit.mp.Buf; 45 import edu.rit.pj.reduction.IntegerOp; 46 import edu.rit.pj.reduction.Op; 47 import edu.rit.pj.reduction.SharedIntegerArray; 48 import edu.rit.util.Range; 49 50 /** 51 * Class SharedUnsigned16BitIntegerArrayBuf_1 provides a buffer for a multiple 52 * thread safe array of unsigned 16-bit integer items sent or received using the 53 * Message Protocol (MP). The array element stride must be 1. While an instance 54 * of class SharedUnsigned16BitIntegerArrayBuf_1 may be constructed directly, 55 * normally you will use a factory method in class {@linkplain 56 * edu.rit.mp.Unsigned16BitIntegerBuf Unsigned16BitIntegerBuf}. See that class 57 * for further information. 58 * 59 * @author Alan Kaminsky 60 * @version 26-Oct-2007 61 */ 62 public class SharedUnsigned16BitIntegerArrayBuf_1 63 extends SharedUnsigned16BitIntegerArrayBuf { 64 65 // Exported constructors. 66 /** 67 * Construct a new shared unsigned 16-bit integer array buffer. 68 * 69 * @param theArray Shared array. 70 * @param theRange Range of array elements to include in the buffer. The 71 * stride is assumed to be 1. 72 */ 73 public SharedUnsigned16BitIntegerArrayBuf_1(SharedIntegerArray theArray, 74 Range theRange) { 75 super(theArray, theRange); 76 } 77 78 // Exported operations. 79 /** 80 * {@inheritDoc} 81 * 82 * Obtain the given item from this buffer. 83 * <P> 84 * The <code>get()</code> method must not block the calling thread; if it does, 85 * all message I/O in MP will be blocked. 86 */ 87 public int get(int i) { 88 return myArray.get(myArrayOffset + i); 89 } 90 91 /** 92 * {@inheritDoc} 93 * 94 * Store the given item in this buffer. 95 * <P> 96 * The <code>put()</code> method must not block the calling thread; if it does, 97 * all message I/O in MP will be blocked. 98 */ 99 public void put(int i, 100 int item) { 101 myArray.set(myArrayOffset + i, item); 102 } 103 104 /** 105 * {@inheritDoc} 106 * 107 * Create a buffer for performing parallel reduction using the given binary 108 * operation. The results of the reduction are placed into this buffer. 109 * @exception ClassCastException (unchecked exception) Thrown if this 110 * buffer's element data type and the given binary operation's argument data 111 * type are not the same. 112 */ 113 public Buf getReductionBuf(Op op) { 114 return new SharedUnsigned16BitIntegerArrayReductionBuf_1(myArray, myRange, (IntegerOp) op); 115 } 116 117 // Hidden operations. 118 /** 119 * {@inheritDoc} 120 * 121 * Send as many items as possible from this buffer to the given byte buffer. 122 * <P> 123 * The <code>sendItems()</code> method must not block the calling thread; if it 124 * does, all message I/O in MP will be blocked. 125 */ 126 protected int sendItems(int i, 127 ByteBuffer buffer) { 128 int index = i; 129 int off = myArrayOffset + i; 130 while (index < myLength && buffer.remaining() >= 2) { 131 buffer.putShort((short) myArray.get(off)); 132 ++index; 133 ++off; 134 } 135 return index - i; 136 } 137 138 /** 139 * {@inheritDoc} 140 * 141 * Receive as many items as possible from the given byte buffer to this 142 * buffer. 143 * <P> 144 * The <code>receiveItems()</code> method must not block the calling thread; if 145 * it does, all message I/O in MP will be blocked. 146 */ 147 protected int receiveItems(int i, 148 int num, 149 ByteBuffer buffer) { 150 int index = i; 151 int off = myArrayOffset + i; 152 int max = Math.min(i + num, myLength); 153 while (index < max && buffer.remaining() >= 2) { 154 myArray.set(off, buffer.getShort() & 0xFFFF); 155 ++index; 156 ++off; 157 } 158 return index - i; 159 } 160 161 }