1 //******************************************************************************
2 //
3 // File: Unsigned16BitIntegerArrayReductionBuf_1.java
4 // Package: edu.rit.mp.buf
5 // Unit: Class edu.rit.mp.buf.Unsigned16BitIntegerArrayReductionBuf_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.mp.Unsigned16BitIntegerBuf;
46 import edu.rit.pj.reduction.IntegerOp;
47 import edu.rit.pj.reduction.Op;
48 import edu.rit.pj.reduction.ReduceArrays;
49 import edu.rit.util.Range;
50
51 /**
52 * Class Unsigned16BitIntegerArrayReductionBuf_1 provides a reduction buffer for
53 * class {@linkplain Unsigned16BitIntegerArrayBuf_1}.
54 *
55 * @author Alan Kaminsky
56 * @version 26-Oct-2007
57 */
58 class Unsigned16BitIntegerArrayReductionBuf_1
59 extends Unsigned16BitIntegerArrayBuf_1 {
60
61 // Hidden data members.
62 IntegerOp myOp;
63
64 // Exported constructors.
65 /**
66 * Construct a new unsigned 16-bit integer array reduction buffer.
67 *
68 * @param theArray Array.
69 * @param theRange Range of array elements to include in the buffer. The
70 * stride is assumed to be 1.
71 * @param op Binary operation.
72 * @exception NullPointerException (unchecked exception) Thrown if
73 * <code>op</code> is null.
74 */
75 public Unsigned16BitIntegerArrayReductionBuf_1(int[] theArray,
76 Range theRange,
77 IntegerOp op) {
78 super(theArray, theRange);
79 if (op == null) {
80 throw new NullPointerException("Unsigned16BitIntegerArrayReductionBuf_1(): op is null");
81 }
82 myOp = op;
83 }
84
85 // Exported operations.
86 /**
87 * {@inheritDoc}
88 *
89 * Store the given item in this buffer.
90 * <P>
91 * The <code>put()</code> method must not block the calling thread; if it does,
92 * all message I/O in MP will be blocked.
93 */
94 public void put(int i,
95 int item) {
96 int off = myArrayOffset + i;
97 myArray[off] = myOp.op(myArray[off], item);
98 }
99
100 /**
101 * {@inheritDoc}
102 *
103 * Copy items from the given buffer to this buffer. The number of items
104 * copied is this buffer's length or <code>theSrc</code>'s length, whichever is
105 * smaller. If <code>theSrc</code> is this buffer, the <code>copy()</code> method
106 * does nothing.
107 * @exception ClassCastException (unchecked exception) Thrown if
108 * <code>theSrc</code>'s item data type is not the same as this buffer's item
109 * data type.
110 */
111 public void copy(Buf theSrc) {
112 if (theSrc == this) {
113 } else if (theSrc instanceof Unsigned16BitIntegerArrayBuf) {
114 Unsigned16BitIntegerArrayBuf src
115 = (Unsigned16BitIntegerArrayBuf) theSrc;
116 ReduceArrays.reduce(src.myArray, src.myRange, this.myArray, this.myRange, myOp);
117 } else {
118 Unsigned16BitIntegerBuf.defaultCopy((Unsigned16BitIntegerBuf) theSrc, this);
119 }
120 }
121
122 /**
123 * {@inheritDoc}
124 *
125 * Create a buffer for performing parallel reduction using the given binary
126 * operation. The results of the reduction are placed into this buffer.
127 * @exception ClassCastException (unchecked exception) Thrown if this
128 * buffer's element data type and the given binary operation's argument data
129 * type are not the same.
130 */
131 public Buf getReductionBuf(Op op) {
132 throw new UnsupportedOperationException();
133 }
134
135 // Hidden operations.
136 /**
137 * {@inheritDoc}
138 *
139 * Receive as many items as possible from the given byte buffer to this
140 * buffer.
141 * <P>
142 * The <code>receiveItems()</code> method must not block the calling thread; if
143 * it does, all message I/O in MP will be blocked.
144 */
145 protected int receiveItems(int i,
146 int num,
147 ByteBuffer buffer) {
148 int index = i;
149 int off = myArrayOffset + i;
150 int max = Math.min(i + num, myLength);
151 while (index < max && buffer.remaining() >= 2) {
152 myArray[off] = myOp.op(myArray[off], buffer.getShort() & 0xFFFF);
153 ++index;
154 ++off;
155 }
156 return index - i;
157 }
158
159 }