1 //****************************************************************************** 2 // 3 // File: ObjectArrayReductionBuf.java 4 // Package: edu.rit.mp.buf 5 // Unit: Class edu.rit.mp.buf.ObjectArrayReductionBuf 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 edu.rit.mp.Buf; 43 import edu.rit.mp.ObjectBuf; 44 import edu.rit.pj.reduction.ObjectOp; 45 import edu.rit.pj.reduction.Op; 46 import edu.rit.pj.reduction.ReduceArrays; 47 import edu.rit.util.Range; 48 49 /** 50 * Class ObjectArrayReductionBuf provides a reduction buffer for class 51 * {@linkplain ObjectArrayBuf}. 52 * 53 * @param <T> Data type of the objects in the buffer. 54 * 55 * @author Alan Kaminsky 56 * @version 23-Mar-2009 57 */ 58 @SuppressWarnings("unchecked") 59 class ObjectArrayReductionBuf<T> 60 extends ObjectArrayBuf<T> { 61 62 // Hidden data members. 63 ObjectOp<T> myOp; 64 ObjectArrayBuf<T> myBuf; 65 66 // Exported constructors. 67 /** 68 * Construct a new object array reduction buffer. 69 * 70 * @param theArray Array. 71 * @param theRange Range of array elements to include in the buffer. 72 * @param op Binary operation. 73 * @param theBuf Underlying object array buffer. 74 * @exception NullPointerException (unchecked exception) Thrown if 75 * <code>op</code> is null. 76 */ 77 public ObjectArrayReductionBuf(T[] theArray, 78 Range theRange, 79 ObjectOp<T> op, 80 ObjectArrayBuf<T> theBuf) { 81 super(theArray, theRange); 82 if (op == null) { 83 throw new NullPointerException("ObjectArrayReductionBuf(): op is null"); 84 } 85 myOp = op; 86 myBuf = theBuf; 87 } 88 89 // Exported operations. 90 /** 91 * Store the given item in this buffer. 92 * <P> 93 * The <code>put()</code> method must not block the calling thread; if it does, 94 * all message I/O in MP will be blocked. 95 * 96 * @param i Item index in the range 0 .. <code>length()</code>-1. 97 * @param item Item to be stored at index <code>i</code>. 98 */ 99 public void put(int i, T item) { 100 int off = myArrayOffset + i * myStride; 101 myArray[off] = myOp.op(myArray[off], item); 102 reset(); 103 myBuf.reset(); 104 } 105 106 /** 107 * {@inheritDoc} 108 * 109 * Copy items from the given buffer to this buffer. The number of items 110 * copied is this buffer's length or <code>theSrc</code>'s length, whichever is 111 * smaller. If <code>theSrc</code> is this buffer, the <code>copy()</code> method 112 * does nothing. 113 * @exception ClassCastException (unchecked exception) Thrown if 114 * <code>theSrc</code>'s item data type is not the same as this buffer's item 115 * data type. 116 */ 117 public void copy(Buf theSrc) { 118 if (theSrc == this) { 119 } else if (theSrc instanceof ObjectArrayBuf) { 120 ObjectArrayBuf<T> src = (ObjectArrayBuf<T>) theSrc; 121 ReduceArrays.reduce(src.myArray, src.myRange, this.myArray, this.myRange, myOp); 122 reset(); 123 myBuf.reset(); 124 } else { 125 ObjectBuf.defaultCopy((ObjectBuf<T>) theSrc, this); 126 reset(); 127 myBuf.reset(); 128 } 129 } 130 131 /** 132 * {@inheritDoc} 133 * 134 * Create a buffer for performing parallel reduction using the given binary 135 * operation. The results of the reduction are placed into this buffer. 136 * @exception ClassCastException (unchecked exception) Thrown if this 137 * buffer's element data type and the given binary operation's argument data 138 * type are not the same. 139 */ 140 public Buf getReductionBuf(Op op) { 141 throw new UnsupportedOperationException(); 142 } 143 144 }