Fri, 06 Mar 2015 16:47:46 +0100
8074561: Wrong volatile qualifier for field ClassLoaderDataGraphKlassIteratorAtomic::_next_klass
Reviewed-by: mgerdin, stefank
duke@435 | 1 | /* |
acorn@4425 | 2 | * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved. |
duke@435 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
duke@435 | 4 | * |
duke@435 | 5 | * This code is free software; you can redistribute it and/or modify it |
duke@435 | 6 | * under the terms of the GNU General Public License version 2 only, as |
duke@435 | 7 | * published by the Free Software Foundation. |
duke@435 | 8 | * |
duke@435 | 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
duke@435 | 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
duke@435 | 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
duke@435 | 12 | * version 2 for more details (a copy is included in the LICENSE file that |
duke@435 | 13 | * accompanied this code). |
duke@435 | 14 | * |
duke@435 | 15 | * You should have received a copy of the GNU General Public License version |
duke@435 | 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
duke@435 | 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
duke@435 | 18 | * |
trims@1907 | 19 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
trims@1907 | 20 | * or visit www.oracle.com if you need additional information or have any |
trims@1907 | 21 | * questions. |
duke@435 | 22 | * |
duke@435 | 23 | */ |
duke@435 | 24 | |
stefank@2314 | 25 | #ifndef SHARE_VM_CLASSFILE_PLACEHOLDERS_HPP |
stefank@2314 | 26 | #define SHARE_VM_CLASSFILE_PLACEHOLDERS_HPP |
stefank@2314 | 27 | |
stefank@2325 | 28 | #include "runtime/thread.hpp" |
stefank@2314 | 29 | #include "utilities/hashtable.hpp" |
stefank@2314 | 30 | |
duke@435 | 31 | class PlaceholderEntry; |
duke@435 | 32 | |
duke@435 | 33 | // Placeholder objects. These represent classes currently |
duke@435 | 34 | // being loaded, as well as arrays of primitives. |
duke@435 | 35 | // |
duke@435 | 36 | |
zgu@3900 | 37 | class PlaceholderTable : public TwoOopHashtable<Symbol*, mtClass> { |
duke@435 | 38 | friend class VMStructs; |
duke@435 | 39 | |
duke@435 | 40 | public: |
duke@435 | 41 | PlaceholderTable(int table_size); |
duke@435 | 42 | |
coleenp@4037 | 43 | PlaceholderEntry* new_entry(int hash, Symbol* name, ClassLoaderData* loader_data, bool havesupername, Symbol* supername); |
coleenp@2497 | 44 | void free_entry(PlaceholderEntry* entry); |
duke@435 | 45 | |
duke@435 | 46 | PlaceholderEntry* bucket(int i) { |
zgu@3900 | 47 | return (PlaceholderEntry*)Hashtable<Symbol*, mtClass>::bucket(i); |
duke@435 | 48 | } |
duke@435 | 49 | |
duke@435 | 50 | PlaceholderEntry** bucket_addr(int i) { |
zgu@3900 | 51 | return (PlaceholderEntry**)Hashtable<Symbol*, mtClass>::bucket_addr(i); |
duke@435 | 52 | } |
duke@435 | 53 | |
duke@435 | 54 | void add_entry(int index, PlaceholderEntry* new_entry) { |
zgu@3900 | 55 | Hashtable<Symbol*, mtClass>::add_entry(index, (HashtableEntry<Symbol*, mtClass>*)new_entry); |
duke@435 | 56 | } |
duke@435 | 57 | |
coleenp@2497 | 58 | void add_entry(int index, unsigned int hash, Symbol* name, |
coleenp@4037 | 59 | ClassLoaderData* loader_data, bool havesupername, Symbol* supername); |
duke@435 | 60 | |
coleenp@2497 | 61 | // This returns a Symbol* to match type for SystemDictionary |
coleenp@2497 | 62 | Symbol* find_entry(int index, unsigned int hash, |
coleenp@4037 | 63 | Symbol* name, ClassLoaderData* loader_data); |
duke@435 | 64 | |
duke@435 | 65 | PlaceholderEntry* get_entry(int index, unsigned int hash, |
coleenp@4037 | 66 | Symbol* name, ClassLoaderData* loader_data); |
duke@435 | 67 | |
duke@435 | 68 | // caller to create a placeholder entry must enumerate an action |
duke@435 | 69 | // caller claims ownership of that action |
duke@435 | 70 | // For parallel classloading: |
duke@435 | 71 | // multiple LOAD_INSTANCE threads can proceed in parallel |
duke@435 | 72 | // multiple LOAD_SUPER threads can proceed in parallel |
duke@435 | 73 | // LOAD_SUPER needed to check for class circularity |
duke@435 | 74 | // DEFINE_CLASS: ultimately define class must be single threaded |
duke@435 | 75 | // on a class/classloader basis |
duke@435 | 76 | // so the head of that queue owns the token |
duke@435 | 77 | // and the rest of the threads return the result the first thread gets |
duke@435 | 78 | enum classloadAction { |
duke@435 | 79 | LOAD_INSTANCE = 1, // calling load_instance_class |
duke@435 | 80 | LOAD_SUPER = 2, // loading superclass for this class |
duke@435 | 81 | DEFINE_CLASS = 3 // find_or_define class |
duke@435 | 82 | }; |
duke@435 | 83 | |
duke@435 | 84 | // find_and_add returns probe pointer - old or new |
acorn@4425 | 85 | // If no entry exists, add a placeholder entry and push SeenThread for classloadAction |
duke@435 | 86 | // If entry exists, reuse entry and push SeenThread for classloadAction |
duke@435 | 87 | PlaceholderEntry* find_and_add(int index, unsigned int hash, |
coleenp@4037 | 88 | Symbol* name, ClassLoaderData* loader_data, |
coleenp@2497 | 89 | classloadAction action, Symbol* supername, |
duke@435 | 90 | Thread* thread); |
duke@435 | 91 | |
duke@435 | 92 | void remove_entry(int index, unsigned int hash, |
coleenp@4037 | 93 | Symbol* name, ClassLoaderData* loader_data); |
duke@435 | 94 | |
acorn@4425 | 95 | // find_and_remove first removes SeenThread for classloadAction |
acorn@4425 | 96 | // If all queues are empty and definer is null, remove the PlacheholderEntry completely |
duke@435 | 97 | void find_and_remove(int index, unsigned int hash, |
acorn@4425 | 98 | Symbol* name, ClassLoaderData* loader_data, |
acorn@4425 | 99 | classloadAction action, Thread* thread); |
duke@435 | 100 | |
duke@435 | 101 | // GC support. |
coleenp@4037 | 102 | void classes_do(KlassClosure* f); |
duke@435 | 103 | |
duke@435 | 104 | // JVMTI support |
coleenp@4037 | 105 | void entries_do(void f(Symbol*)); |
duke@435 | 106 | |
duke@435 | 107 | #ifndef PRODUCT |
duke@435 | 108 | void print(); |
duke@435 | 109 | #endif |
duke@435 | 110 | void verify(); |
duke@435 | 111 | }; |
duke@435 | 112 | |
duke@435 | 113 | // SeenThread objects represent list of threads that are |
duke@435 | 114 | // currently performing a load action on a class. |
duke@435 | 115 | // For class circularity, set before loading a superclass. |
duke@435 | 116 | // For bootclasssearchpath, set before calling load_instance_class. |
duke@435 | 117 | // Defining must be single threaded on a class/classloader basis |
duke@435 | 118 | // For DEFINE_CLASS, the head of the queue owns the |
duke@435 | 119 | // define token and the rest of the threads wait to return the |
duke@435 | 120 | // result the first thread gets. |
zgu@3900 | 121 | class SeenThread: public CHeapObj<mtInternal> { |
duke@435 | 122 | private: |
duke@435 | 123 | Thread *_thread; |
duke@435 | 124 | SeenThread* _stnext; |
duke@435 | 125 | SeenThread* _stprev; |
duke@435 | 126 | public: |
duke@435 | 127 | SeenThread(Thread *thread) { |
duke@435 | 128 | _thread = thread; |
duke@435 | 129 | _stnext = NULL; |
duke@435 | 130 | _stprev = NULL; |
duke@435 | 131 | } |
duke@435 | 132 | Thread* thread() const { return _thread;} |
duke@435 | 133 | void set_thread(Thread *thread) { _thread = thread; } |
duke@435 | 134 | |
duke@435 | 135 | SeenThread* next() const { return _stnext;} |
duke@435 | 136 | void set_next(SeenThread *seen) { _stnext = seen; } |
duke@435 | 137 | void set_prev(SeenThread *seen) { _stprev = seen; } |
duke@435 | 138 | |
duke@435 | 139 | #ifndef PRODUCT |
duke@435 | 140 | void printActionQ() { |
duke@435 | 141 | SeenThread* seen = this; |
duke@435 | 142 | while (seen != NULL) { |
duke@435 | 143 | seen->thread()->print_value(); |
duke@435 | 144 | tty->print(", "); |
duke@435 | 145 | seen = seen->next(); |
duke@435 | 146 | } |
duke@435 | 147 | } |
duke@435 | 148 | #endif // PRODUCT |
duke@435 | 149 | }; |
duke@435 | 150 | |
duke@435 | 151 | // Placeholder objects represent classes currently being loaded. |
duke@435 | 152 | // All threads examining the placeholder table must hold the |
duke@435 | 153 | // SystemDictionary_lock, so we don't need special precautions |
duke@435 | 154 | // on store ordering here. |
duke@435 | 155 | // The system dictionary is the only user of this class. |
duke@435 | 156 | |
zgu@3900 | 157 | class PlaceholderEntry : public HashtableEntry<Symbol*, mtClass> { |
duke@435 | 158 | friend class VMStructs; |
duke@435 | 159 | |
duke@435 | 160 | |
duke@435 | 161 | private: |
coleenp@4037 | 162 | ClassLoaderData* _loader_data; // initiating loader |
duke@435 | 163 | bool _havesupername; // distinguish between null supername, and unknown |
coleenp@2497 | 164 | Symbol* _supername; |
duke@435 | 165 | Thread* _definer; // owner of define token |
coleenp@4037 | 166 | Klass* _instanceKlass; // InstanceKlass from successful define |
duke@435 | 167 | SeenThread* _superThreadQ; // doubly-linked queue of Threads loading a superclass for this class |
duke@435 | 168 | SeenThread* _loadInstanceThreadQ; // loadInstance thread |
duke@435 | 169 | // can be multiple threads if classloader object lock broken by application |
duke@435 | 170 | // or if classloader supports parallel classloading |
duke@435 | 171 | |
duke@435 | 172 | SeenThread* _defineThreadQ; // queue of Threads trying to define this class |
duke@435 | 173 | // including _definer |
duke@435 | 174 | // _definer owns token |
duke@435 | 175 | // queue waits for and returns results from _definer |
duke@435 | 176 | |
duke@435 | 177 | public: |
duke@435 | 178 | // Simple accessors, used only by SystemDictionary |
coleenp@2497 | 179 | Symbol* klassname() const { return literal(); } |
duke@435 | 180 | |
coleenp@4037 | 181 | ClassLoaderData* loader_data() const { return _loader_data; } |
coleenp@4037 | 182 | void set_loader_data(ClassLoaderData* loader_data) { _loader_data = loader_data; } |
duke@435 | 183 | |
duke@435 | 184 | bool havesupername() const { return _havesupername; } |
duke@435 | 185 | void set_havesupername(bool havesupername) { _havesupername = havesupername; } |
duke@435 | 186 | |
coleenp@2497 | 187 | Symbol* supername() const { return _supername; } |
coleenp@2497 | 188 | void set_supername(Symbol* supername) { |
coleenp@2497 | 189 | _supername = supername; |
coleenp@2497 | 190 | if (_supername != NULL) _supername->increment_refcount(); |
coleenp@2497 | 191 | } |
duke@435 | 192 | |
duke@435 | 193 | Thread* definer() const {return _definer; } |
duke@435 | 194 | void set_definer(Thread* definer) { _definer = definer; } |
duke@435 | 195 | |
hseigel@4278 | 196 | Klass* instance_klass() const {return _instanceKlass; } |
hseigel@4278 | 197 | void set_instance_klass(Klass* ik) { _instanceKlass = ik; } |
duke@435 | 198 | |
duke@435 | 199 | SeenThread* superThreadQ() const { return _superThreadQ; } |
duke@435 | 200 | void set_superThreadQ(SeenThread* SeenThread) { _superThreadQ = SeenThread; } |
duke@435 | 201 | |
duke@435 | 202 | SeenThread* loadInstanceThreadQ() const { return _loadInstanceThreadQ; } |
duke@435 | 203 | void set_loadInstanceThreadQ(SeenThread* SeenThread) { _loadInstanceThreadQ = SeenThread; } |
duke@435 | 204 | |
duke@435 | 205 | SeenThread* defineThreadQ() const { return _defineThreadQ; } |
duke@435 | 206 | void set_defineThreadQ(SeenThread* SeenThread) { _defineThreadQ = SeenThread; } |
duke@435 | 207 | |
duke@435 | 208 | PlaceholderEntry* next() const { |
zgu@3900 | 209 | return (PlaceholderEntry*)HashtableEntry<Symbol*, mtClass>::next(); |
duke@435 | 210 | } |
duke@435 | 211 | |
duke@435 | 212 | PlaceholderEntry** next_addr() { |
zgu@3900 | 213 | return (PlaceholderEntry**)HashtableEntry<Symbol*, mtClass>::next_addr(); |
duke@435 | 214 | } |
duke@435 | 215 | |
duke@435 | 216 | // Test for equality |
duke@435 | 217 | // Entries are unique for class/classloader name pair |
coleenp@4037 | 218 | bool equals(Symbol* class_name, ClassLoaderData* loader) const { |
coleenp@4037 | 219 | return (klassname() == class_name && loader_data() == loader); |
duke@435 | 220 | } |
duke@435 | 221 | |
duke@435 | 222 | SeenThread* actionToQueue(PlaceholderTable::classloadAction action) { |
duke@435 | 223 | SeenThread* queuehead; |
duke@435 | 224 | switch (action) { |
duke@435 | 225 | case PlaceholderTable::LOAD_INSTANCE: |
duke@435 | 226 | queuehead = _loadInstanceThreadQ; |
duke@435 | 227 | break; |
duke@435 | 228 | case PlaceholderTable::LOAD_SUPER: |
duke@435 | 229 | queuehead = _superThreadQ; |
duke@435 | 230 | break; |
duke@435 | 231 | case PlaceholderTable::DEFINE_CLASS: |
duke@435 | 232 | queuehead = _defineThreadQ; |
duke@435 | 233 | break; |
duke@435 | 234 | default: Unimplemented(); |
duke@435 | 235 | } |
duke@435 | 236 | return queuehead; |
duke@435 | 237 | } |
duke@435 | 238 | |
duke@435 | 239 | void set_threadQ(SeenThread* seenthread, PlaceholderTable::classloadAction action) { |
duke@435 | 240 | switch (action) { |
duke@435 | 241 | case PlaceholderTable::LOAD_INSTANCE: |
duke@435 | 242 | _loadInstanceThreadQ = seenthread; |
duke@435 | 243 | break; |
duke@435 | 244 | case PlaceholderTable::LOAD_SUPER: |
duke@435 | 245 | _superThreadQ = seenthread; |
duke@435 | 246 | break; |
duke@435 | 247 | case PlaceholderTable::DEFINE_CLASS: |
duke@435 | 248 | _defineThreadQ = seenthread; |
duke@435 | 249 | break; |
duke@435 | 250 | default: Unimplemented(); |
duke@435 | 251 | } |
duke@435 | 252 | return; |
duke@435 | 253 | } |
duke@435 | 254 | |
duke@435 | 255 | bool super_load_in_progress() { |
duke@435 | 256 | return (_superThreadQ != NULL); |
duke@435 | 257 | } |
duke@435 | 258 | |
duke@435 | 259 | bool instance_load_in_progress() { |
duke@435 | 260 | return (_loadInstanceThreadQ != NULL); |
duke@435 | 261 | } |
duke@435 | 262 | |
duke@435 | 263 | bool define_class_in_progress() { |
duke@435 | 264 | return (_defineThreadQ != NULL); |
duke@435 | 265 | } |
duke@435 | 266 | |
duke@435 | 267 | // Doubly-linked list of Threads per action for class/classloader pair |
duke@435 | 268 | // Class circularity support: links in thread before loading superclass |
duke@435 | 269 | // bootstrapsearchpath support: links in a thread before load_instance_class |
duke@435 | 270 | // definers: use as queue of define requestors, including owner of |
duke@435 | 271 | // define token. Appends for debugging of requestor order |
duke@435 | 272 | void add_seen_thread(Thread* thread, PlaceholderTable::classloadAction action) { |
duke@435 | 273 | assert_lock_strong(SystemDictionary_lock); |
duke@435 | 274 | SeenThread* threadEntry = new SeenThread(thread); |
duke@435 | 275 | SeenThread* seen = actionToQueue(action); |
duke@435 | 276 | |
duke@435 | 277 | if (seen == NULL) { |
duke@435 | 278 | set_threadQ(threadEntry, action); |
duke@435 | 279 | return; |
duke@435 | 280 | } |
duke@435 | 281 | SeenThread* next; |
duke@435 | 282 | while ((next = seen->next()) != NULL) { |
duke@435 | 283 | seen = next; |
duke@435 | 284 | } |
duke@435 | 285 | seen->set_next(threadEntry); |
duke@435 | 286 | threadEntry->set_prev(seen); |
duke@435 | 287 | return; |
duke@435 | 288 | } |
duke@435 | 289 | |
duke@435 | 290 | bool check_seen_thread(Thread* thread, PlaceholderTable::classloadAction action) { |
duke@435 | 291 | assert_lock_strong(SystemDictionary_lock); |
duke@435 | 292 | SeenThread* threadQ = actionToQueue(action); |
duke@435 | 293 | SeenThread* seen = threadQ; |
duke@435 | 294 | while (seen) { |
duke@435 | 295 | if (thread == seen->thread()) { |
duke@435 | 296 | return true; |
duke@435 | 297 | } |
duke@435 | 298 | seen = seen->next(); |
duke@435 | 299 | } |
duke@435 | 300 | return false; |
duke@435 | 301 | } |
duke@435 | 302 | |
duke@435 | 303 | // returns true if seenthreadQ is now empty |
duke@435 | 304 | // Note, caller must ensure probe still exists while holding |
duke@435 | 305 | // SystemDictionary_lock |
duke@435 | 306 | // ignores if cleanup has already been done |
duke@435 | 307 | // if found, deletes SeenThread |
duke@435 | 308 | bool remove_seen_thread(Thread* thread, PlaceholderTable::classloadAction action) { |
duke@435 | 309 | assert_lock_strong(SystemDictionary_lock); |
duke@435 | 310 | SeenThread* threadQ = actionToQueue(action); |
duke@435 | 311 | SeenThread* seen = threadQ; |
duke@435 | 312 | SeenThread* prev = NULL; |
duke@435 | 313 | while (seen) { |
duke@435 | 314 | if (thread == seen->thread()) { |
duke@435 | 315 | if (prev) { |
duke@435 | 316 | prev->set_next(seen->next()); |
duke@435 | 317 | } else { |
duke@435 | 318 | set_threadQ(seen->next(), action); |
duke@435 | 319 | } |
duke@435 | 320 | if (seen->next()) { |
duke@435 | 321 | seen->next()->set_prev(prev); |
duke@435 | 322 | } |
duke@435 | 323 | delete seen; |
duke@435 | 324 | break; |
duke@435 | 325 | } |
duke@435 | 326 | prev = seen; |
duke@435 | 327 | seen = seen->next(); |
duke@435 | 328 | } |
duke@435 | 329 | return (actionToQueue(action) == NULL); |
duke@435 | 330 | } |
duke@435 | 331 | |
duke@435 | 332 | // GC support |
duke@435 | 333 | // Applies "f->do_oop" to all root oops in the placeholder table. |
coleenp@4037 | 334 | void classes_do(KlassClosure* closure); |
duke@435 | 335 | |
duke@435 | 336 | // Print method doesn't append a cr |
duke@435 | 337 | void print() const PRODUCT_RETURN; |
duke@435 | 338 | void verify() const; |
duke@435 | 339 | }; |
stefank@2314 | 340 | |
stefank@2314 | 341 | #endif // SHARE_VM_CLASSFILE_PLACEHOLDERS_HPP |