Mercurial > hg > truffle
annotate src/share/vm/utilities/taskqueue.hpp @ 375:81cd571500b0
6725697: par compact - rename class ChunkData to RegionData
Reviewed-by: iveresov, tonyp
| author | jcoomes |
|---|---|
| date | Tue, 30 Sep 2008 12:20:22 -0700 |
| parents | 1ee8caae33af |
| children | 23673011938d |
| rev | line source |
|---|---|
| 0 | 1 /* |
| 196 | 2 * Copyright 2001-2008 Sun Microsystems, Inc. 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 * | |
| 19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, | |
| 20 * CA 95054 USA or visit www.sun.com if you need additional information or | |
| 21 * have any questions. | |
| 22 * | |
| 23 */ | |
| 24 | |
| 25 class TaskQueueSuper: public CHeapObj { | |
| 26 protected: | |
| 27 // The first free element after the last one pushed (mod _n). | |
| 28 // (For now we'll assume only 32-bit CAS). | |
| 29 volatile juint _bottom; | |
| 30 | |
| 31 // log2 of the size of the queue. | |
| 32 enum SomeProtectedConstants { | |
| 33 Log_n = 14 | |
| 34 }; | |
| 35 | |
| 36 // Size of the queue. | |
| 37 juint n() { return (1 << Log_n); } | |
| 38 // For computing "x mod n" efficiently. | |
| 39 juint n_mod_mask() { return n() - 1; } | |
| 40 | |
| 41 struct Age { | |
| 42 jushort _top; | |
| 43 jushort _tag; | |
| 44 | |
| 45 jushort tag() const { return _tag; } | |
| 46 jushort top() const { return _top; } | |
| 47 | |
| 48 Age() { _tag = 0; _top = 0; } | |
| 49 | |
| 50 friend bool operator ==(const Age& a1, const Age& a2) { | |
| 51 return a1.tag() == a2.tag() && a1.top() == a2.top(); | |
| 52 } | |
| 53 | |
| 54 }; | |
| 55 Age _age; | |
| 56 // These make sure we do single atomic reads and writes. | |
| 57 Age get_age() { | |
| 58 jint res = *(volatile jint*)(&_age); | |
| 59 return *(Age*)(&res); | |
| 60 } | |
| 61 void set_age(Age a) { | |
| 62 *(volatile jint*)(&_age) = *(int*)(&a); | |
| 63 } | |
| 64 | |
| 65 jushort get_top() { | |
| 66 return get_age().top(); | |
| 67 } | |
| 68 | |
| 69 // These both operate mod _n. | |
| 70 juint increment_index(juint ind) { | |
| 71 return (ind + 1) & n_mod_mask(); | |
| 72 } | |
| 73 juint decrement_index(juint ind) { | |
| 74 return (ind - 1) & n_mod_mask(); | |
| 75 } | |
| 76 | |
| 77 // Returns a number in the range [0.._n). If the result is "n-1", it | |
| 78 // should be interpreted as 0. | |
| 79 juint dirty_size(juint bot, juint top) { | |
| 80 return ((jint)bot - (jint)top) & n_mod_mask(); | |
| 81 } | |
| 82 | |
| 83 // Returns the size corresponding to the given "bot" and "top". | |
| 84 juint size(juint bot, juint top) { | |
| 85 juint sz = dirty_size(bot, top); | |
| 86 // Has the queue "wrapped", so that bottom is less than top? | |
| 87 // There's a complicated special case here. A pair of threads could | |
| 88 // perform pop_local and pop_global operations concurrently, starting | |
| 89 // from a state in which _bottom == _top+1. The pop_local could | |
| 90 // succeed in decrementing _bottom, and the pop_global in incrementing | |
| 91 // _top (in which case the pop_global will be awarded the contested | |
| 92 // queue element.) The resulting state must be interpreted as an empty | |
| 93 // queue. (We only need to worry about one such event: only the queue | |
| 94 // owner performs pop_local's, and several concurrent threads | |
| 95 // attempting to perform the pop_global will all perform the same CAS, | |
| 96 // and only one can succeed. Any stealing thread that reads after | |
| 97 // either the increment or decrement will seen an empty queue, and will | |
| 98 // not join the competitors. The "sz == -1 || sz == _n-1" state will | |
| 99 // not be modified by concurrent queues, so the owner thread can reset | |
| 100 // the state to _bottom == top so subsequent pushes will be performed | |
| 101 // normally. | |
| 102 if (sz == (n()-1)) return 0; | |
| 103 else return sz; | |
| 104 } | |
| 105 | |
| 106 public: | |
| 107 TaskQueueSuper() : _bottom(0), _age() {} | |
| 108 | |
| 109 // Return "true" if the TaskQueue contains any tasks. | |
| 110 bool peek(); | |
| 111 | |
| 112 // Return an estimate of the number of elements in the queue. | |
| 113 // The "careful" version admits the possibility of pop_local/pop_global | |
| 114 // races. | |
| 115 juint size() { | |
| 116 return size(_bottom, get_top()); | |
| 117 } | |
| 118 | |
| 119 juint dirty_size() { | |
| 120 return dirty_size(_bottom, get_top()); | |
| 121 } | |
| 122 | |
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123 void set_empty() { |
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124 _bottom = 0; |
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125 _age = Age(); |
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126 } |
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127 |
| 0 | 128 // Maximum number of elements allowed in the queue. This is two less |
| 129 // than the actual queue size, for somewhat complicated reasons. | |
| 130 juint max_elems() { return n() - 2; } | |
| 131 | |
| 132 }; | |
| 133 | |
| 134 template<class E> class GenericTaskQueue: public TaskQueueSuper { | |
| 135 private: | |
| 136 // Slow paths for push, pop_local. (pop_global has no fast path.) | |
| 137 bool push_slow(E t, juint dirty_n_elems); | |
| 138 bool pop_local_slow(juint localBot, Age oldAge); | |
| 139 | |
| 140 public: | |
| 141 // Initializes the queue to empty. | |
| 142 GenericTaskQueue(); | |
| 143 | |
| 144 void initialize(); | |
| 145 | |
| 146 // Push the task "t" on the queue. Returns "false" iff the queue is | |
| 147 // full. | |
| 148 inline bool push(E t); | |
| 149 | |
| 150 // If succeeds in claiming a task (from the 'local' end, that is, the | |
| 151 // most recently pushed task), returns "true" and sets "t" to that task. | |
| 152 // Otherwise, the queue is empty and returns false. | |
| 153 inline bool pop_local(E& t); | |
| 154 | |
| 155 // If succeeds in claiming a task (from the 'global' end, that is, the | |
| 156 // least recently pushed task), returns "true" and sets "t" to that task. | |
| 157 // Otherwise, the queue is empty and returns false. | |
| 158 bool pop_global(E& t); | |
| 159 | |
| 160 // Delete any resource associated with the queue. | |
| 161 ~GenericTaskQueue(); | |
| 162 | |
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163 // apply the closure to all elements in the task queue |
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164 void oops_do(OopClosure* f); |
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165 |
| 0 | 166 private: |
| 167 // Element array. | |
| 168 volatile E* _elems; | |
| 169 }; | |
| 170 | |
| 171 template<class E> | |
| 172 GenericTaskQueue<E>::GenericTaskQueue():TaskQueueSuper() { | |
| 173 assert(sizeof(Age) == sizeof(jint), "Depends on this."); | |
| 174 } | |
| 175 | |
| 176 template<class E> | |
| 177 void GenericTaskQueue<E>::initialize() { | |
| 178 _elems = NEW_C_HEAP_ARRAY(E, n()); | |
| 179 guarantee(_elems != NULL, "Allocation failed."); | |
| 180 } | |
| 181 | |
| 182 template<class E> | |
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183 void GenericTaskQueue<E>::oops_do(OopClosure* f) { |
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184 // tty->print_cr("START OopTaskQueue::oops_do"); |
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185 int iters = size(); |
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186 juint index = _bottom; |
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187 for (int i = 0; i < iters; ++i) { |
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188 index = decrement_index(index); |
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189 // tty->print_cr(" doing entry %d," INTPTR_T " -> " INTPTR_T, |
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190 // index, &_elems[index], _elems[index]); |
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191 E* t = (E*)&_elems[index]; // cast away volatility |
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192 oop* p = (oop*)t; |
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193 assert((*t)->is_oop_or_null(), "Not an oop or null"); |
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194 f->do_oop(p); |
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195 } |
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196 // tty->print_cr("END OopTaskQueue::oops_do"); |
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197 } |
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198 |
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199 |
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200 template<class E> |
| 0 | 201 bool GenericTaskQueue<E>::push_slow(E t, juint dirty_n_elems) { |
| 202 if (dirty_n_elems == n() - 1) { | |
| 203 // Actually means 0, so do the push. | |
| 204 juint localBot = _bottom; | |
| 205 _elems[localBot] = t; | |
| 206 _bottom = increment_index(localBot); | |
| 207 return true; | |
| 208 } else | |
| 209 return false; | |
| 210 } | |
| 211 | |
| 212 template<class E> | |
| 213 bool GenericTaskQueue<E>:: | |
| 214 pop_local_slow(juint localBot, Age oldAge) { | |
| 215 // This queue was observed to contain exactly one element; either this | |
| 216 // thread will claim it, or a competing "pop_global". In either case, | |
| 217 // the queue will be logically empty afterwards. Create a new Age value | |
| 218 // that represents the empty queue for the given value of "_bottom". (We | |
| 219 // must also increment "tag" because of the case where "bottom == 1", | |
| 220 // "top == 0". A pop_global could read the queue element in that case, | |
| 221 // then have the owner thread do a pop followed by another push. Without | |
| 222 // the incrementing of "tag", the pop_global's CAS could succeed, | |
| 223 // allowing it to believe it has claimed the stale element.) | |
| 224 Age newAge; | |
| 225 newAge._top = localBot; | |
| 226 newAge._tag = oldAge.tag() + 1; | |
| 227 // Perhaps a competing pop_global has already incremented "top", in which | |
| 228 // case it wins the element. | |
| 229 if (localBot == oldAge.top()) { | |
| 230 Age tempAge; | |
| 231 // No competing pop_global has yet incremented "top"; we'll try to | |
| 232 // install new_age, thus claiming the element. | |
| 233 assert(sizeof(Age) == sizeof(jint) && sizeof(jint) == sizeof(juint), | |
| 234 "Assumption about CAS unit."); | |
| 235 *(jint*)&tempAge = Atomic::cmpxchg(*(jint*)&newAge, (volatile jint*)&_age, *(jint*)&oldAge); | |
| 236 if (tempAge == oldAge) { | |
| 237 // We win. | |
| 238 assert(dirty_size(localBot, get_top()) != n() - 1, | |
| 239 "Shouldn't be possible..."); | |
| 240 return true; | |
| 241 } | |
| 242 } | |
| 243 // We fail; a completing pop_global gets the element. But the queue is | |
| 244 // empty (and top is greater than bottom.) Fix this representation of | |
| 245 // the empty queue to become the canonical one. | |
| 246 set_age(newAge); | |
| 247 assert(dirty_size(localBot, get_top()) != n() - 1, | |
| 248 "Shouldn't be possible..."); | |
| 249 return false; | |
| 250 } | |
| 251 | |
| 252 template<class E> | |
| 253 bool GenericTaskQueue<E>::pop_global(E& t) { | |
| 254 Age newAge; | |
| 255 Age oldAge = get_age(); | |
| 256 juint localBot = _bottom; | |
| 257 juint n_elems = size(localBot, oldAge.top()); | |
| 258 if (n_elems == 0) { | |
| 259 return false; | |
| 260 } | |
| 261 t = _elems[oldAge.top()]; | |
| 262 newAge = oldAge; | |
| 263 newAge._top = increment_index(newAge.top()); | |
| 264 if ( newAge._top == 0 ) newAge._tag++; | |
| 265 Age resAge; | |
| 266 *(jint*)&resAge = Atomic::cmpxchg(*(jint*)&newAge, (volatile jint*)&_age, *(jint*)&oldAge); | |
| 267 // Note that using "_bottom" here might fail, since a pop_local might | |
| 268 // have decremented it. | |
| 269 assert(dirty_size(localBot, newAge._top) != n() - 1, | |
| 270 "Shouldn't be possible..."); | |
| 271 return (resAge == oldAge); | |
| 272 } | |
| 273 | |
| 274 template<class E> | |
| 275 GenericTaskQueue<E>::~GenericTaskQueue() { | |
| 276 FREE_C_HEAP_ARRAY(E, _elems); | |
| 277 } | |
| 278 | |
| 279 // Inherits the typedef of "Task" from above. | |
| 280 class TaskQueueSetSuper: public CHeapObj { | |
| 281 protected: | |
| 282 static int randomParkAndMiller(int* seed0); | |
| 283 public: | |
| 284 // Returns "true" if some TaskQueue in the set contains a task. | |
| 285 virtual bool peek() = 0; | |
| 286 }; | |
| 287 | |
| 288 template<class E> class GenericTaskQueueSet: public TaskQueueSetSuper { | |
| 289 private: | |
| 290 int _n; | |
| 291 GenericTaskQueue<E>** _queues; | |
| 292 | |
| 293 public: | |
| 294 GenericTaskQueueSet(int n) : _n(n) { | |
| 295 typedef GenericTaskQueue<E>* GenericTaskQueuePtr; | |
| 296 _queues = NEW_C_HEAP_ARRAY(GenericTaskQueuePtr, n); | |
| 297 guarantee(_queues != NULL, "Allocation failure."); | |
| 298 for (int i = 0; i < n; i++) { | |
| 299 _queues[i] = NULL; | |
| 300 } | |
| 301 } | |
| 302 | |
| 303 bool steal_1_random(int queue_num, int* seed, E& t); | |
| 304 bool steal_best_of_2(int queue_num, int* seed, E& t); | |
| 305 bool steal_best_of_all(int queue_num, int* seed, E& t); | |
| 306 | |
| 307 void register_queue(int i, GenericTaskQueue<E>* q); | |
| 308 | |
| 309 GenericTaskQueue<E>* queue(int n); | |
| 310 | |
| 311 // The thread with queue number "queue_num" (and whose random number seed | |
| 312 // is at "seed") is trying to steal a task from some other queue. (It | |
| 313 // may try several queues, according to some configuration parameter.) | |
| 314 // If some steal succeeds, returns "true" and sets "t" the stolen task, | |
| 315 // otherwise returns false. | |
| 316 bool steal(int queue_num, int* seed, E& t); | |
| 317 | |
| 318 bool peek(); | |
| 319 }; | |
| 320 | |
| 321 template<class E> | |
| 322 void GenericTaskQueueSet<E>::register_queue(int i, GenericTaskQueue<E>* q) { | |
| 323 assert(0 <= i && i < _n, "index out of range."); | |
| 324 _queues[i] = q; | |
| 325 } | |
| 326 | |
| 327 template<class E> | |
| 328 GenericTaskQueue<E>* GenericTaskQueueSet<E>::queue(int i) { | |
| 329 return _queues[i]; | |
| 330 } | |
| 331 | |
| 332 template<class E> | |
| 333 bool GenericTaskQueueSet<E>::steal(int queue_num, int* seed, E& t) { | |
| 334 for (int i = 0; i < 2 * _n; i++) | |
| 335 if (steal_best_of_2(queue_num, seed, t)) | |
| 336 return true; | |
| 337 return false; | |
| 338 } | |
| 339 | |
| 340 template<class E> | |
| 341 bool GenericTaskQueueSet<E>::steal_best_of_all(int queue_num, int* seed, E& t) { | |
| 342 if (_n > 2) { | |
| 343 int best_k; | |
| 344 jint best_sz = 0; | |
| 345 for (int k = 0; k < _n; k++) { | |
| 346 if (k == queue_num) continue; | |
| 347 jint sz = _queues[k]->size(); | |
| 348 if (sz > best_sz) { | |
| 349 best_sz = sz; | |
| 350 best_k = k; | |
| 351 } | |
| 352 } | |
| 353 return best_sz > 0 && _queues[best_k]->pop_global(t); | |
| 354 } else if (_n == 2) { | |
| 355 // Just try the other one. | |
| 356 int k = (queue_num + 1) % 2; | |
| 357 return _queues[k]->pop_global(t); | |
| 358 } else { | |
| 359 assert(_n == 1, "can't be zero."); | |
| 360 return false; | |
| 361 } | |
| 362 } | |
| 363 | |
| 364 template<class E> | |
| 365 bool GenericTaskQueueSet<E>::steal_1_random(int queue_num, int* seed, E& t) { | |
| 366 if (_n > 2) { | |
| 367 int k = queue_num; | |
| 368 while (k == queue_num) k = randomParkAndMiller(seed) % _n; | |
| 369 return _queues[2]->pop_global(t); | |
| 370 } else if (_n == 2) { | |
| 371 // Just try the other one. | |
| 372 int k = (queue_num + 1) % 2; | |
| 373 return _queues[k]->pop_global(t); | |
| 374 } else { | |
| 375 assert(_n == 1, "can't be zero."); | |
| 376 return false; | |
| 377 } | |
| 378 } | |
| 379 | |
| 380 template<class E> | |
| 381 bool GenericTaskQueueSet<E>::steal_best_of_2(int queue_num, int* seed, E& t) { | |
| 382 if (_n > 2) { | |
| 383 int k1 = queue_num; | |
| 384 while (k1 == queue_num) k1 = randomParkAndMiller(seed) % _n; | |
| 385 int k2 = queue_num; | |
| 386 while (k2 == queue_num || k2 == k1) k2 = randomParkAndMiller(seed) % _n; | |
| 387 // Sample both and try the larger. | |
| 388 juint sz1 = _queues[k1]->size(); | |
| 389 juint sz2 = _queues[k2]->size(); | |
| 390 if (sz2 > sz1) return _queues[k2]->pop_global(t); | |
| 391 else return _queues[k1]->pop_global(t); | |
| 392 } else if (_n == 2) { | |
| 393 // Just try the other one. | |
| 394 int k = (queue_num + 1) % 2; | |
| 395 return _queues[k]->pop_global(t); | |
| 396 } else { | |
| 397 assert(_n == 1, "can't be zero."); | |
| 398 return false; | |
| 399 } | |
| 400 } | |
| 401 | |
| 402 template<class E> | |
| 403 bool GenericTaskQueueSet<E>::peek() { | |
| 404 // Try all the queues. | |
| 405 for (int j = 0; j < _n; j++) { | |
| 406 if (_queues[j]->peek()) | |
| 407 return true; | |
| 408 } | |
| 409 return false; | |
| 410 } | |
| 411 | |
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412 // When to terminate from the termination protocol. |
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413 class TerminatorTerminator: public CHeapObj { |
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414 public: |
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415 virtual bool should_exit_termination() = 0; |
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416 }; |
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417 |
| 0 | 418 // A class to aid in the termination of a set of parallel tasks using |
| 419 // TaskQueueSet's for work stealing. | |
| 420 | |
| 421 class ParallelTaskTerminator: public StackObj { | |
| 422 private: | |
| 423 int _n_threads; | |
| 424 TaskQueueSetSuper* _queue_set; | |
| 425 jint _offered_termination; | |
| 426 | |
| 427 bool peek_in_queue_set(); | |
| 428 protected: | |
| 429 virtual void yield(); | |
| 430 void sleep(uint millis); | |
| 431 | |
| 432 public: | |
| 433 | |
| 434 // "n_threads" is the number of threads to be terminated. "queue_set" is a | |
| 435 // queue sets of work queues of other threads. | |
| 436 ParallelTaskTerminator(int n_threads, TaskQueueSetSuper* queue_set); | |
| 437 | |
| 438 // The current thread has no work, and is ready to terminate if everyone | |
| 439 // else is. If returns "true", all threads are terminated. If returns | |
| 440 // "false", available work has been observed in one of the task queues, | |
| 441 // so the global task is not complete. | |
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442 bool offer_termination() { |
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443 return offer_termination(NULL); |
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444 } |
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445 |
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446 // As above, but it also terminates of the should_exit_termination() |
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447 // method of the terminator parameter returns true. If terminator is |
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448 // NULL, then it is ignored. |
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449 bool offer_termination(TerminatorTerminator* terminator); |
| 0 | 450 |
| 451 // Reset the terminator, so that it may be reused again. | |
| 452 // The caller is responsible for ensuring that this is done | |
| 453 // in an MT-safe manner, once the previous round of use of | |
| 454 // the terminator is finished. | |
| 455 void reset_for_reuse(); | |
| 456 | |
| 457 }; | |
| 458 | |
| 459 #define SIMPLE_STACK 0 | |
| 460 | |
| 461 template<class E> inline bool GenericTaskQueue<E>::push(E t) { | |
| 462 #if SIMPLE_STACK | |
| 463 juint localBot = _bottom; | |
| 464 if (_bottom < max_elems()) { | |
| 465 _elems[localBot] = t; | |
| 466 _bottom = localBot + 1; | |
| 467 return true; | |
| 468 } else { | |
| 469 return false; | |
| 470 } | |
| 471 #else | |
| 472 juint localBot = _bottom; | |
| 473 assert((localBot >= 0) && (localBot < n()), "_bottom out of range."); | |
| 474 jushort top = get_top(); | |
| 475 juint dirty_n_elems = dirty_size(localBot, top); | |
| 476 assert((dirty_n_elems >= 0) && (dirty_n_elems < n()), | |
| 477 "n_elems out of range."); | |
| 478 if (dirty_n_elems < max_elems()) { | |
| 479 _elems[localBot] = t; | |
| 480 _bottom = increment_index(localBot); | |
| 481 return true; | |
| 482 } else { | |
| 483 return push_slow(t, dirty_n_elems); | |
| 484 } | |
| 485 #endif | |
| 486 } | |
| 487 | |
| 488 template<class E> inline bool GenericTaskQueue<E>::pop_local(E& t) { | |
| 489 #if SIMPLE_STACK | |
| 490 juint localBot = _bottom; | |
| 491 assert(localBot > 0, "precondition."); | |
| 492 localBot--; | |
| 493 t = _elems[localBot]; | |
| 494 _bottom = localBot; | |
| 495 return true; | |
| 496 #else | |
| 497 juint localBot = _bottom; | |
| 498 // This value cannot be n-1. That can only occur as a result of | |
| 499 // the assignment to bottom in this method. If it does, this method | |
| 500 // resets the size( to 0 before the next call (which is sequential, | |
| 501 // since this is pop_local.) | |
| 502 juint dirty_n_elems = dirty_size(localBot, get_top()); | |
| 503 assert(dirty_n_elems != n() - 1, "Shouldn't be possible..."); | |
| 504 if (dirty_n_elems == 0) return false; | |
| 505 localBot = decrement_index(localBot); | |
| 506 _bottom = localBot; | |
| 507 // This is necessary to prevent any read below from being reordered | |
| 508 // before the store just above. | |
| 509 OrderAccess::fence(); | |
| 510 t = _elems[localBot]; | |
| 511 // This is a second read of "age"; the "size()" above is the first. | |
| 512 // If there's still at least one element in the queue, based on the | |
| 513 // "_bottom" and "age" we've read, then there can be no interference with | |
| 514 // a "pop_global" operation, and we're done. | |
| 515 juint tp = get_top(); | |
| 516 if (size(localBot, tp) > 0) { | |
| 517 assert(dirty_size(localBot, tp) != n() - 1, | |
| 518 "Shouldn't be possible..."); | |
| 519 return true; | |
| 520 } else { | |
| 521 // Otherwise, the queue contained exactly one element; we take the slow | |
| 522 // path. | |
| 523 return pop_local_slow(localBot, get_age()); | |
| 524 } | |
| 525 #endif | |
| 526 } | |
| 527 | |
| 528 typedef oop Task; | |
| 529 typedef GenericTaskQueue<Task> OopTaskQueue; | |
| 530 typedef GenericTaskQueueSet<Task> OopTaskQueueSet; | |
| 531 | |
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532 |
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533 #define COMPRESSED_OOP_MASK 1 |
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534 |
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535 // This is a container class for either an oop* or a narrowOop*. |
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536 // Both are pushed onto a task queue and the consumer will test is_narrow() |
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537 // to determine which should be processed. |
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538 class StarTask { |
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539 void* _holder; // either union oop* or narrowOop* |
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540 public: |
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541 StarTask(narrowOop *p) { _holder = (void *)((uintptr_t)p | COMPRESSED_OOP_MASK); } |
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542 StarTask(oop *p) { _holder = (void*)p; } |
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543 StarTask() { _holder = NULL; } |
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544 operator oop*() { return (oop*)_holder; } |
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545 operator narrowOop*() { |
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546 return (narrowOop*)((uintptr_t)_holder & ~COMPRESSED_OOP_MASK); |
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547 } |
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548 |
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549 // Operators to preserve const/volatile in assignments required by gcc |
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550 void operator=(const volatile StarTask& t) volatile { _holder = t._holder; } |
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551 |
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552 bool is_narrow() const { |
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553 return (((uintptr_t)_holder & COMPRESSED_OOP_MASK) != 0); |
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554 } |
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555 }; |
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556 |
| 0 | 557 typedef GenericTaskQueue<StarTask> OopStarTaskQueue; |
| 558 typedef GenericTaskQueueSet<StarTask> OopStarTaskQueueSet; | |
| 559 | |
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560 typedef size_t RegionTask; // index for region |
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561 typedef GenericTaskQueue<RegionTask> RegionTaskQueue; |
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562 typedef GenericTaskQueueSet<RegionTask> RegionTaskQueueSet; |
| 0 | 563 |
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564 class RegionTaskQueueWithOverflow: public CHeapObj { |
| 0 | 565 protected: |
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566 RegionTaskQueue _region_queue; |
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567 GrowableArray<RegionTask>* _overflow_stack; |
| 0 | 568 |
| 569 public: | |
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570 RegionTaskQueueWithOverflow() : _overflow_stack(NULL) {} |
| 0 | 571 // Initialize both stealable queue and overflow |
| 572 void initialize(); | |
| 573 // Save first to stealable queue and then to overflow | |
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574 void save(RegionTask t); |
| 0 | 575 // Retrieve first from overflow and then from stealable queue |
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576 bool retrieve(RegionTask& region_index); |
| 0 | 577 // Retrieve from stealable queue |
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578 bool retrieve_from_stealable_queue(RegionTask& region_index); |
| 0 | 579 // Retrieve from overflow |
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580 bool retrieve_from_overflow(RegionTask& region_index); |
| 0 | 581 bool is_empty(); |
| 582 bool stealable_is_empty(); | |
| 583 bool overflow_is_empty(); | |
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584 juint stealable_size() { return _region_queue.size(); } |
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585 RegionTaskQueue* task_queue() { return &_region_queue; } |
| 0 | 586 }; |
| 587 | |
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588 #define USE_RegionTaskQueueWithOverflow |