1 //******************************************************************************
2 //
3 // File: SharedSigned8BitIntegerArrayBuf_1.java
4 // Package: edu.rit.mp.buf
5 // Unit: Class edu.rit.mp.buf.SharedSigned8BitIntegerArrayBuf_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 SharedSigned8BitIntegerArrayBuf_1 provides a buffer for a multiple
52 * thread safe array of signed 8-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 SharedSigned8BitIntegerArrayBuf_1 may be constructed directly,
55 * normally you will use a factory method in class {@linkplain
56 * edu.rit.mp.Signed8BitIntegerBuf Signed8BitIntegerBuf}. See that class for
57 * further information.
58 *
59 * @author Alan Kaminsky
60 * @version 26-Oct-2007
61 */
62 public class SharedSigned8BitIntegerArrayBuf_1
63 extends SharedSigned8BitIntegerArrayBuf {
64
65 // Exported constructors.
66 /**
67 * Construct a new shared signed 8-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 SharedSigned8BitIntegerArrayBuf_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 SharedSigned8BitIntegerArrayReductionBuf_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() >= 1) {
131 buffer.put((byte) 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() >= 1) {
154 myArray.set(off, buffer.get());
155 ++index;
156 ++off;
157 }
158 return index - i;
159 }
160
161 }