1 /*
2 * Copyright (c) 1997, 2006, 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 # include "incls/_precompiled.incl"
26 # include "incls/_symbolKlass.cpp.incl"
27
28 symbolOop symbolKlass::allocate_symbol(u1* name, int len, TRAPS) {
29 // Don't allow symbol oops to be created which cannot fit in a symbolOop.
30 if (len > symbolOopDesc::max_length()) {
31 THROW_MSG_0(vmSymbols::java_lang_InternalError(),
32 "name is too long to represent");
33 }
34 int size = symbolOopDesc::object_size(len);
35 symbolKlassHandle h_k(THREAD, as_klassOop());
36 symbolOop sym = (symbolOop)
37 CollectedHeap::permanent_obj_allocate(h_k, size, CHECK_NULL);
38 assert(!sym->is_parsable(), "not expecting parsability yet.");
39 No_Safepoint_Verifier no_safepoint;
40 sym->set_utf8_length(len);
41 for (int i = 0; i < len; i++) {
42 sym->byte_at_put(i, name[i]);
43 }
44 // Let the first emptySymbol be created and
45 // ensure only one is ever created.
46 assert(sym->is_parsable() || Universe::emptySymbol() == NULL,
47 "should be parsable here.");
48 return sym;
49 }
50
51 bool symbolKlass::allocate_symbols(int names_count, const char** names,
52 int* lengths, symbolOop* sym_oops, TRAPS) {
53 if (UseConcMarkSweepGC || UseParallelGC) {
54 // Concurrent GC needs to mark all the allocated symbol oops after
55 // the remark phase which isn't done below (except the first symbol oop).
56 // So return false which will let the symbols be allocated one by one.
57 // The parallel collector uses an object start array to find the
58 // start of objects on a dirty card. The object start array is not
59 // updated for the start of each symbol so is not precise. During
60 // object array verification this causes a verification failure.
61 // In a product build this causes extra searching for the start of
62 // a symbol. As with the concurrent collector a return of false will
63 // cause each symbol to be allocated separately and in the case
64 // of the parallel collector will cause the object
65 // start array to be updated.
66 return false;
67 }
68
69 assert(names_count > 0, "can't allocate 0 symbols");
70
71 int total_size = 0;
72 int i, sizes[SymbolTable::symbol_alloc_batch_size];
73 for (i=0; i<names_count; i++) {
74 int len = lengths[i];
75 if (len > symbolOopDesc::max_length()) {
76 return false;
77 }
78 int sz = symbolOopDesc::object_size(len);
79 sizes[i] = sz * HeapWordSize;
80 total_size += sz;
81 }
82 symbolKlassHandle h_k(THREAD, as_klassOop());
83 HeapWord* base = Universe::heap()->permanent_mem_allocate(total_size);
84 if (base == NULL) {
85 return false;
86 }
87
88 // CAN'T take any safepoint during the initialization of the symbol oops !
89 No_Safepoint_Verifier nosafepoint;
90
91 klassOop sk = h_k();
92 int pos = 0;
93 for (i=0; i<names_count; i++) {
94 symbolOop s = (symbolOop) (((char*)base) + pos);
95 s->set_mark(markOopDesc::prototype());
96 s->set_klass(sk);
97 s->set_utf8_length(lengths[i]);
98 const char* name = names[i];
99 for (int j=0; j<lengths[i]; j++) {
100 s->byte_at_put(j, name[j]);
101 }
102
103 assert(s->is_parsable(), "should be parsable here.");
104
105 sym_oops[i] = s;
106 pos += sizes[i];
107 }
108 return true;
109 }
110
111 klassOop symbolKlass::create_klass(TRAPS) {
112 symbolKlass o;
113 KlassHandle h_this_klass(THREAD, Universe::klassKlassObj());
114 KlassHandle k = base_create_klass(h_this_klass, header_size(), o.vtbl_value(), CHECK_NULL);
115 // Make sure size calculation is right
116 assert(k()->size() == align_object_size(header_size()), "wrong size for object");
117 // java_lang_Class::create_mirror(k, CHECK_NULL); // Allocate mirror
118 return k();
119 }
120
121 int symbolKlass::oop_size(oop obj) const {
122 assert(obj->is_symbol(),"must be a symbol");
123 symbolOop s = symbolOop(obj);
124 int size = s->object_size();
125 return size;
126 }
127
128 bool symbolKlass::oop_is_parsable(oop obj) const {
129 assert(obj->is_symbol(),"must be a symbol");
130 symbolOop s = symbolOop(obj);
131 return s->object_is_parsable();
132 }
133
134 void symbolKlass::oop_follow_contents(oop obj) {
135 assert (obj->is_symbol(), "object must be symbol");
136 // Performance tweak: We skip iterating over the klass pointer since we
137 // know that Universe::symbolKlassObj never moves.
138 // Note: do not follow next link here (see SymbolTable::follow_contents)
139 }
140
141 #ifndef SERIALGC
142 void symbolKlass::oop_follow_contents(ParCompactionManager* cm, oop obj) {
143 assert (obj->is_symbol(), "object must be symbol");
144 // Performance tweak: We skip iterating over the klass pointer since we
145 // know that Universe::symbolKlassObj never moves.
146 // Note: do not follow next link here (see SymbolTable::follow_contents)
147 }
148 #endif // SERIALGC
149
150 int symbolKlass::oop_oop_iterate(oop obj, OopClosure* blk) {
151 assert(obj->is_symbol(), "object must be symbol");
152 symbolOop s = symbolOop(obj);
153 // Get size before changing pointers.
154 // Don't call size() or oop_size() since that is a virtual call.
155 int size = s->object_size();
156 // Performance tweak: We skip iterating over the klass pointer since we
157 // know that Universe::symbolKlassObj never moves.
158 return size;
159 }
160
161
162 int symbolKlass::oop_oop_iterate_m(oop obj, OopClosure* blk, MemRegion mr) {
163 assert(obj->is_symbol(), "object must be symbol");
164 symbolOop s = symbolOop(obj);
165 // Get size before changing pointers.
166 // Don't call size() or oop_size() since that is a virtual call.
167 int size = s->object_size();
168 // Performance tweak: We skip iterating over the klass pointer since we
169 // know that Universe::symbolKlassObj never moves.
170 return size;
171 }
172
173
174 int symbolKlass::oop_adjust_pointers(oop obj) {
175 assert(obj->is_symbol(), "should be symbol");
176 symbolOop s = symbolOop(obj);
177 // Get size before changing pointers.
178 // Don't call size() or oop_size() since that is a virtual call.
179 int size = s->object_size();
180 // Performance tweak: We skip iterating over the klass pointer since we
181 // know that Universe::symbolKlassObj never moves.
182 return size;
183 }
184
185
186 #ifndef SERIALGC
187 void symbolKlass::oop_push_contents(PSPromotionManager* pm, oop obj) {
188 assert(obj->is_symbol(), "should be symbol");
189 }
190
191 int symbolKlass::oop_update_pointers(ParCompactionManager* cm, oop obj) {
192 assert(obj->is_symbol(), "should be symbol");
193 return symbolOop(obj)->object_size();
194 }
195
196 int symbolKlass::oop_update_pointers(ParCompactionManager* cm, oop obj,
197 HeapWord* beg_addr, HeapWord* end_addr) {
198 assert(obj->is_symbol(), "should be symbol");
199 return symbolOop(obj)->object_size();
200 }
201 #endif // SERIALGC
202
203 #ifndef PRODUCT
204 // Printing
205
206 void symbolKlass::oop_print_on(oop obj, outputStream* st) {
207 st->print("Symbol: '");
208 symbolOop(obj)->print_symbol_on(st);
209 st->print("'");
210 }
211
212 #endif //PRODUCT
213
214 void symbolKlass::oop_print_value_on(oop obj, outputStream* st) {
215 symbolOop sym = symbolOop(obj);
216 st->print("'");
217 for (int i = 0; i < sym->utf8_length(); i++) {
218 st->print("%c", sym->byte_at(i));
219 }
220 st->print("'");
221 }
222
223 const char* symbolKlass::internal_name() const {
224 return "{symbol}";
225 }