Mercurial > hg > truffle
comparison src/share/vm/oops/symbol.cpp @ 2177:3582bf76420e
6990754: Use native memory and reference counting to implement SymbolTable
Summary: move symbols from permgen into C heap and reference count them
Reviewed-by: never, acorn, jmasa, stefank
author | coleenp |
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date | Thu, 27 Jan 2011 16:11:27 -0800 |
parents | src/share/vm/oops/symbolOop.cpp@f95d63e2154a |
children | 1d1603768966 |
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2176:27e4ea99855d | 2177:3582bf76420e |
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1 /* | |
2 * Copyright (c) 1997, 2009, Oracle and/or its affiliates. All rights reserved. | |
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 * | |
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA | |
20 * or visit www.oracle.com if you need additional information or have any | |
21 * questions. | |
22 * | |
23 */ | |
24 | |
25 | |
26 #include "precompiled.hpp" | |
27 #include "oops/oop.inline.hpp" | |
28 #include "oops/symbol.hpp" | |
29 #include "runtime/os.hpp" | |
30 #include "memory/allocation.inline.hpp" | |
31 | |
32 Symbol::Symbol(const u1* name, int length) : _refcount(0), _length(length) { | |
33 _identity_hash = os::random(); | |
34 for (int i = 0; i < _length; i++) { | |
35 byte_at_put(i, name[i]); | |
36 } | |
37 } | |
38 | |
39 void* Symbol::operator new(size_t size, int len) { | |
40 return (void *) AllocateHeap(object_size(len) * HeapWordSize, "symbol"); | |
41 } | |
42 | |
43 // ------------------------------------------------------------------ | |
44 // Symbol::equals | |
45 // | |
46 // Compares the symbol with a string of the given length. | |
47 bool Symbol::equals(const char* str, int len) const { | |
48 int l = utf8_length(); | |
49 if (l != len) return false; | |
50 while (l-- > 0) { | |
51 if (str[l] != (char) byte_at(l)) | |
52 return false; | |
53 } | |
54 assert(l == -1, "we should be at the beginning"); | |
55 return true; | |
56 } | |
57 | |
58 | |
59 // ------------------------------------------------------------------ | |
60 // Symbol::starts_with | |
61 // | |
62 // Tests if the symbol starts with the specified prefix of the given | |
63 // length. | |
64 bool Symbol::starts_with(const char* prefix, int len) const { | |
65 if (len > utf8_length()) return false; | |
66 while (len-- > 0) { | |
67 if (prefix[len] != (char) byte_at(len)) | |
68 return false; | |
69 } | |
70 assert(len == -1, "we should be at the beginning"); | |
71 return true; | |
72 } | |
73 | |
74 | |
75 // ------------------------------------------------------------------ | |
76 // Symbol::index_of | |
77 // | |
78 // Finds if the given string is a substring of this symbol's utf8 bytes. | |
79 // Return -1 on failure. Otherwise return the first index where str occurs. | |
80 int Symbol::index_of_at(int i, const char* str, int len) const { | |
81 assert(i >= 0 && i <= utf8_length(), "oob"); | |
82 if (len <= 0) return 0; | |
83 char first_char = str[0]; | |
84 address bytes = (address) ((Symbol*)this)->base(); | |
85 address limit = bytes + utf8_length() - len; // inclusive limit | |
86 address scan = bytes + i; | |
87 if (scan > limit) | |
88 return -1; | |
89 for (;;) { | |
90 scan = (address) memchr(scan, first_char, (limit + 1 - scan)); | |
91 if (scan == NULL) | |
92 return -1; // not found | |
93 assert(scan >= bytes+i && scan <= limit, "scan oob"); | |
94 if (memcmp(scan, str, len) == 0) | |
95 return (int)(scan - bytes); | |
96 } | |
97 } | |
98 | |
99 | |
100 char* Symbol::as_C_string(char* buf, int size) const { | |
101 if (size > 0) { | |
102 int len = MIN2(size - 1, utf8_length()); | |
103 for (int i = 0; i < len; i++) { | |
104 buf[i] = byte_at(i); | |
105 } | |
106 buf[len] = '\0'; | |
107 } | |
108 return buf; | |
109 } | |
110 | |
111 char* Symbol::as_C_string() const { | |
112 int len = utf8_length(); | |
113 char* str = NEW_RESOURCE_ARRAY(char, len + 1); | |
114 return as_C_string(str, len + 1); | |
115 } | |
116 | |
117 char* Symbol::as_C_string_flexible_buffer(Thread* t, | |
118 char* buf, int size) const { | |
119 char* str; | |
120 int len = utf8_length(); | |
121 int buf_len = len + 1; | |
122 if (size < buf_len) { | |
123 str = NEW_RESOURCE_ARRAY(char, buf_len); | |
124 } else { | |
125 str = buf; | |
126 } | |
127 return as_C_string(str, buf_len); | |
128 } | |
129 | |
130 void Symbol::print_symbol_on(outputStream* st) const { | |
131 st = st ? st : tty; | |
132 int length = UTF8::unicode_length((const char*)bytes(), utf8_length()); | |
133 const char *ptr = (const char *)bytes(); | |
134 jchar value; | |
135 for (int index = 0; index < length; index++) { | |
136 ptr = UTF8::next(ptr, &value); | |
137 if (value >= 32 && value < 127 || value == '\'' || value == '\\') { | |
138 st->put(value); | |
139 } else { | |
140 st->print("\\u%04x", value); | |
141 } | |
142 } | |
143 } | |
144 | |
145 jchar* Symbol::as_unicode(int& length) const { | |
146 Symbol* this_ptr = (Symbol*)this; | |
147 length = UTF8::unicode_length((char*)this_ptr->bytes(), utf8_length()); | |
148 jchar* result = NEW_RESOURCE_ARRAY(jchar, length); | |
149 if (length > 0) { | |
150 UTF8::convert_to_unicode((char*)this_ptr->bytes(), result, length); | |
151 } | |
152 return result; | |
153 } | |
154 | |
155 const char* Symbol::as_klass_external_name(char* buf, int size) const { | |
156 if (size > 0) { | |
157 char* str = as_C_string(buf, size); | |
158 int length = (int)strlen(str); | |
159 // Turn all '/'s into '.'s (also for array klasses) | |
160 for (int index = 0; index < length; index++) { | |
161 if (str[index] == '/') { | |
162 str[index] = '.'; | |
163 } | |
164 } | |
165 return str; | |
166 } else { | |
167 return buf; | |
168 } | |
169 } | |
170 | |
171 const char* Symbol::as_klass_external_name() const { | |
172 char* str = as_C_string(); | |
173 int length = (int)strlen(str); | |
174 // Turn all '/'s into '.'s (also for array klasses) | |
175 for (int index = 0; index < length; index++) { | |
176 if (str[index] == '/') { | |
177 str[index] = '.'; | |
178 } | |
179 } | |
180 return str; | |
181 } | |
182 | |
183 | |
184 void Symbol::print_on(outputStream* st) const { | |
185 if (this == NULL) { | |
186 st->print_cr("NULL"); | |
187 } else { | |
188 st->print("Symbol: '"); | |
189 print_symbol_on(st); | |
190 st->print("'"); | |
191 st->print(" count %d", refcount()); | |
192 } | |
193 } | |
194 | |
195 // The print_value functions are present in all builds, to support the | |
196 // disassembler and error reporting. | |
197 void Symbol::print_value_on(outputStream* st) const { | |
198 if (this == NULL) { | |
199 st->print("NULL"); | |
200 } else { | |
201 st->print("'"); | |
202 for (int i = 0; i < utf8_length(); i++) { | |
203 st->print("%c", byte_at(i)); | |
204 } | |
205 st->print("'"); | |
206 } | |
207 } | |
208 | |
209 void Symbol::increment_refcount() { | |
210 // Only increment the refcount if positive. If negative either | |
211 // overflow has occurred or it is a permanent symbol in a read only | |
212 // shared archive. | |
213 if (_refcount >= 0) { | |
214 Atomic::inc(&_refcount); | |
215 NOT_PRODUCT(Atomic::inc(&_total_count);) | |
216 } | |
217 } | |
218 | |
219 void Symbol::decrement_refcount() { | |
220 if (_refcount >= 0) { | |
221 Atomic::dec(&_refcount); | |
222 #ifdef ASSERT | |
223 if (_refcount < 0) { | |
224 print(); | |
225 assert(false, "reference count underflow for symbol"); | |
226 } | |
227 #endif | |
228 } | |
229 } | |
230 | |
231 NOT_PRODUCT(int Symbol::_total_count = 0;) |