Mercurial > hg > truffle
annotate agent/src/share/classes/sun/jvm/hotspot/code/CompressedReadStream.java @ 11997:cd25d3be91c5
8012144: multiple SIGSEGVs fails on staxf
Summary: Forward port of 7u change to add additional fence() on RMO platforms, with a load_acquire on all platforms
Reviewed-by: dholmes, kvn
author | vladidan |
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date | Tue, 06 Aug 2013 20:01:40 -0400 |
parents | c18cbe5936b8 |
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rev | line source |
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0 | 1 /* |
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6941466: Oracle rebranding changes for Hotspot repositories
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2 * Copyright (c) 2000, 2005, Oracle and/or its affiliates. All rights reserved. |
0 | 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
4 * | |
5 * This code is free software; you can redistribute it and/or modify it | |
6 * under the terms of the GNU General Public License version 2 only, as | |
7 * published by the Free Software Foundation. | |
8 * | |
9 * This code is distributed in the hope that it will be useful, but WITHOUT | |
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
12 * version 2 for more details (a copy is included in the LICENSE file that | |
13 * accompanied this code). | |
14 * | |
15 * You should have received a copy of the GNU General Public License version | |
16 * 2 along with this work; if not, write to the Free Software Foundation, | |
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | |
18 * | |
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6941466: Oracle rebranding changes for Hotspot repositories
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
c18cbe5936b8
6941466: Oracle rebranding changes for Hotspot repositories
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20 * or visit www.oracle.com if you need additional information or have any |
c18cbe5936b8
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21 * questions. |
0 | 22 * |
23 */ | |
24 | |
25 package sun.jvm.hotspot.code; | |
26 | |
27 import sun.jvm.hotspot.debugger.*; | |
28 | |
29 public class CompressedReadStream extends CompressedStream { | |
30 /** Equivalent to CompressedReadStream(buffer, 0) */ | |
31 public CompressedReadStream(Address buffer) { | |
32 this(buffer, 0); | |
33 } | |
34 | |
35 public CompressedReadStream(Address buffer, int position) { | |
36 super(buffer, position); | |
37 } | |
38 | |
39 public boolean readBoolean() { | |
40 return (read() != 0); | |
41 } | |
42 | |
43 public byte readByte() { | |
44 return (byte) read(); | |
45 } | |
46 | |
47 public char readChar() { | |
48 return (char) readInt(); | |
49 } | |
50 | |
51 public short readShort() { | |
52 return (short) readSignedInt(); | |
53 } | |
54 | |
55 public int readSignedInt() { | |
56 return decodeSign(readInt()); | |
57 } | |
58 | |
59 public int readInt() { | |
60 int b0 = read(); | |
61 if (b0 < L) { | |
62 return b0; | |
63 } else { | |
64 return readIntMb(b0); | |
65 } | |
66 } | |
67 | |
68 | |
69 public float readFloat() { | |
70 return Float.intBitsToFloat(reverseInt(readInt())); | |
71 } | |
72 | |
73 public double readDouble() { | |
74 int rh = readInt(); | |
75 int rl = readInt(); | |
76 int h = reverseInt(rh); | |
77 int l = reverseInt(rl); | |
78 return Double.longBitsToDouble((h << 32) | ((long)l & 0x00000000FFFFFFFFL)); | |
79 } | |
80 | |
81 public long readLong() { | |
82 long low = readSignedInt() & 0x00000000FFFFFFFFL; | |
83 long high = readSignedInt(); | |
84 return (high << 32) | low; | |
85 } | |
86 | |
87 //-------------------------------------------------------------------------------- | |
88 // Internals only below this point | |
89 // | |
90 | |
91 | |
92 // This encoding, called UNSIGNED5, is taken from J2SE Pack200. | |
93 // It assumes that most values have lots of leading zeroes. | |
94 // Very small values, in the range [0..191], code in one byte. | |
95 // Any 32-bit value (including negatives) can be coded, in | |
96 // up to five bytes. The grammar is: | |
97 // low_byte = [0..191] | |
98 // high_byte = [192..255] | |
99 // any_byte = low_byte | high_byte | |
100 // coding = low_byte | |
101 // | high_byte low_byte | |
102 // | high_byte high_byte low_byte | |
103 // | high_byte high_byte high_byte low_byte | |
104 // | high_byte high_byte high_byte high_byte any_byte | |
105 // Each high_byte contributes six bits of payload. | |
106 // The encoding is one-to-one (except for integer overflow) | |
107 // and easy to parse and unparse. | |
108 | |
109 private int readIntMb(int b0) { | |
110 int pos = position - 1; | |
111 int sum = b0; | |
112 // must collect more bytes: b[1]...b[4] | |
113 int lg_H_i = lg_H; | |
114 for (int i = 0; ;) { | |
115 int b_i = read(pos + (++i)); | |
116 sum += b_i << lg_H_i; // sum += b[i]*(64**i) | |
117 if (b_i < L || i == MAX_i) { | |
118 setPosition(pos+i+1); | |
119 return sum; | |
120 } | |
121 lg_H_i += lg_H; | |
122 } | |
123 } | |
124 | |
125 private short read(int index) { | |
126 return (short) buffer.getCIntegerAt(index, 1, true); | |
127 } | |
128 | |
129 /** Reads an unsigned byte, but returns it as a short */ | |
130 private short read() { | |
131 short retval = (short) buffer.getCIntegerAt(position, 1, true); | |
132 ++position; | |
133 return retval; | |
134 } | |
135 } |