1 /*
2 * Copyright (c) 1997, 2017, 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 *
232 // We take care not to be blocking while holding the
233 // SymbolTable_lock. Otherwise, the system might deadlock, since the
234 // symboltable is used during compilation (VM_thread) The lock free
235 // synchronization is simplified by the fact that we do not delete
236 // entries in the symbol table during normal execution (only during
237 // safepoints).
238
239 Symbol* SymbolTable::lookup(const char* name, int len, TRAPS) {
240 unsigned int hashValue = hash_symbol(name, len);
241 int index = the_table()->hash_to_index(hashValue);
242
243 Symbol* s = the_table()->lookup(index, name, len, hashValue);
244
245 // Found
246 if (s != NULL) return s;
247
248 // Grab SymbolTable_lock first.
249 MutexLocker ml(SymbolTable_lock, THREAD);
250
251 // Otherwise, add to symbol to table
252 return the_table()->basic_add(index, (u1*)name, len, hashValue, true, CHECK_NULL);
253 }
254
255 Symbol* SymbolTable::lookup(const Symbol* sym, int begin, int end, TRAPS) {
256 char* buffer;
257 int index, len;
258 unsigned int hashValue;
259 char* name;
260 {
261 debug_only(No_Safepoint_Verifier nsv;)
262
263 name = (char*)sym->base() + begin;
264 len = end - begin;
265 hashValue = hash_symbol(name, len);
266 index = the_table()->hash_to_index(hashValue);
267 Symbol* s = the_table()->lookup(index, name, len, hashValue);
268
269 // Found
270 if (s != NULL) return s;
271 }
272
273 // Otherwise, add to symbol to table. Copy to a C string first.
274 char stack_buf[128];
275 ResourceMark rm(THREAD);
276 if (len <= 128) {
277 buffer = stack_buf;
278 } else {
279 buffer = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, len);
280 }
281 for (int i=0; i<len; i++) {
282 buffer[i] = name[i];
283 }
284 // Make sure there is no safepoint in the code above since name can't move.
285 // We can't include the code in No_Safepoint_Verifier because of the
286 // ResourceMark.
287
288 // Grab SymbolTable_lock first.
289 MutexLocker ml(SymbolTable_lock, THREAD);
290
291 return the_table()->basic_add(index, (u1*)buffer, len, hashValue, true, CHECK_NULL);
292 }
293
294 Symbol* SymbolTable::lookup_only(const char* name, int len,
295 unsigned int& hash) {
296 hash = hash_symbol(name, len);
297 int index = the_table()->hash_to_index(hash);
298
299 Symbol* s = the_table()->lookup(index, name, len, hash);
300 return s;
301 }
302
303 // Look up the address of the literal in the SymbolTable for this Symbol*
304 // Do not create any new symbols
305 // Do not increment the reference count to keep this alive
306 Symbol** SymbolTable::lookup_symbol_addr(Symbol* sym){
307 unsigned int hash = hash_symbol((char*)sym->bytes(), sym->utf8_length());
308 int index = the_table()->hash_to_index(hash);
309
310 for (HashtableEntry<Symbol*, mtSymbol>* e = the_table()->bucket(index); e != NULL; e = e->next()) {
311 if (e->hash() == hash) {
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1 /*
2 * Copyright (c) 1997, 2019, 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 *
232 // We take care not to be blocking while holding the
233 // SymbolTable_lock. Otherwise, the system might deadlock, since the
234 // symboltable is used during compilation (VM_thread) The lock free
235 // synchronization is simplified by the fact that we do not delete
236 // entries in the symbol table during normal execution (only during
237 // safepoints).
238
239 Symbol* SymbolTable::lookup(const char* name, int len, TRAPS) {
240 unsigned int hashValue = hash_symbol(name, len);
241 int index = the_table()->hash_to_index(hashValue);
242
243 Symbol* s = the_table()->lookup(index, name, len, hashValue);
244
245 // Found
246 if (s != NULL) return s;
247
248 // Grab SymbolTable_lock first.
249 MutexLocker ml(SymbolTable_lock, THREAD);
250
251 // Otherwise, add to symbol to table
252 return the_table()->basic_add(index, (u1*)name, len, hashValue, true, THREAD);
253 }
254
255 Symbol* SymbolTable::lookup(const Symbol* sym, int begin, int end, TRAPS) {
256 char* buffer;
257 int index, len;
258 unsigned int hashValue;
259 char* name;
260 {
261 debug_only(No_Safepoint_Verifier nsv;)
262
263 name = (char*)sym->base() + begin;
264 len = end - begin;
265 hashValue = hash_symbol(name, len);
266 index = the_table()->hash_to_index(hashValue);
267 Symbol* s = the_table()->lookup(index, name, len, hashValue);
268
269 // Found
270 if (s != NULL) return s;
271 }
272
273 // Otherwise, add to symbol to table. Copy to a C string first.
274 char stack_buf[128];
275 ResourceMark rm(THREAD);
276 if (len <= 128) {
277 buffer = stack_buf;
278 } else {
279 buffer = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, len);
280 }
281 for (int i=0; i<len; i++) {
282 buffer[i] = name[i];
283 }
284 // Make sure there is no safepoint in the code above since name can't move.
285 // We can't include the code in No_Safepoint_Verifier because of the
286 // ResourceMark.
287
288 // Grab SymbolTable_lock first.
289 MutexLocker ml(SymbolTable_lock, THREAD);
290
291 return the_table()->basic_add(index, (u1*)buffer, len, hashValue, true, THREAD);
292 }
293
294 Symbol* SymbolTable::lookup_only(const char* name, int len,
295 unsigned int& hash) {
296 hash = hash_symbol(name, len);
297 int index = the_table()->hash_to_index(hash);
298
299 Symbol* s = the_table()->lookup(index, name, len, hash);
300 return s;
301 }
302
303 // Look up the address of the literal in the SymbolTable for this Symbol*
304 // Do not create any new symbols
305 // Do not increment the reference count to keep this alive
306 Symbol** SymbolTable::lookup_symbol_addr(Symbol* sym){
307 unsigned int hash = hash_symbol((char*)sym->bytes(), sym->utf8_length());
308 int index = the_table()->hash_to_index(hash);
309
310 for (HashtableEntry<Symbol*, mtSymbol>* e = the_table()->bucket(index); e != NULL; e = e->next()) {
311 if (e->hash() == hash) {
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