Mercurial > hg > truffle
annotate src/share/vm/gc_implementation/parNew/parNewGeneration.hpp @ 113:ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
Summary: Compressed oops in instances, arrays, and headers. Code contributors are coleenp, phh, never, swamyv
Reviewed-by: jmasa, kamg, acorn, tbell, kvn, rasbold
| author | coleenp |
|---|---|
| date | Sun, 13 Apr 2008 17:43:42 -0400 |
| parents | a61af66fc99e |
| children | d1605aabd0a1 |
| rev | line source |
|---|---|
| 0 | 1 /* |
| 2 * Copyright 2001-2007 Sun Microsystems, Inc. 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 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 ChunkArray; | |
| 26 class ParScanWithoutBarrierClosure; | |
| 27 class ParScanWithBarrierClosure; | |
| 28 class ParRootScanWithoutBarrierClosure; | |
| 29 class ParRootScanWithBarrierTwoGensClosure; | |
| 30 class ParEvacuateFollowersClosure; | |
| 31 | |
| 32 // It would be better if these types could be kept local to the .cpp file, | |
| 33 // but they must be here to allow ParScanClosure::do_oop_work to be defined | |
| 34 // in genOopClosures.inline.hpp. | |
| 35 | |
| 36 typedef OopTaskQueue ObjToScanQueue; | |
| 37 typedef OopTaskQueueSet ObjToScanQueueSet; | |
| 38 | |
| 39 // Enable this to get push/pop/steal stats. | |
| 40 const int PAR_STATS_ENABLED = 0; | |
| 41 | |
| 42 class ParKeepAliveClosure: public DefNewGeneration::KeepAliveClosure { | |
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43 private: |
| 0 | 44 ParScanWeakRefClosure* _par_cl; |
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45 protected: |
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46 template <class T> void do_oop_work(T* p); |
| 0 | 47 public: |
| 48 ParKeepAliveClosure(ParScanWeakRefClosure* cl); | |
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49 virtual void do_oop(oop* p); |
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50 virtual void do_oop(narrowOop* p); |
| 0 | 51 }; |
| 52 | |
| 53 // The state needed by thread performing parallel young-gen collection. | |
| 54 class ParScanThreadState { | |
| 55 friend class ParScanThreadStateSet; | |
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56 private: |
| 0 | 57 ObjToScanQueue *_work_queue; |
| 58 | |
| 59 ParGCAllocBuffer _to_space_alloc_buffer; | |
| 60 | |
| 61 ParScanWithoutBarrierClosure _to_space_closure; // scan_without_gc_barrier | |
| 62 ParScanWithBarrierClosure _old_gen_closure; // scan_with_gc_barrier | |
| 63 ParRootScanWithoutBarrierClosure _to_space_root_closure; // scan_root_without_gc_barrier | |
| 64 // One of these two will be passed to process_strong_roots, which will | |
| 65 // set its generation. The first is for two-gen configs where the | |
| 66 // old gen collects the perm gen; the second is for arbitrary configs. | |
| 67 // The second isn't used right now (it used to be used for the train, an | |
| 68 // incremental collector) but the declaration has been left as a reminder. | |
| 69 ParRootScanWithBarrierTwoGensClosure _older_gen_closure; | |
| 70 // This closure will always be bound to the old gen; it will be used | |
| 71 // in evacuate_followers. | |
| 72 ParRootScanWithBarrierTwoGensClosure _old_gen_root_closure; // scan_old_root_with_gc_barrier | |
| 73 ParEvacuateFollowersClosure _evacuate_followers; | |
| 74 DefNewGeneration::IsAliveClosure _is_alive_closure; | |
| 75 ParScanWeakRefClosure _scan_weak_ref_closure; | |
| 76 ParKeepAliveClosure _keep_alive_closure; | |
| 77 | |
| 78 | |
| 79 Space* _to_space; | |
| 80 Space* to_space() { return _to_space; } | |
| 81 | |
| 82 Generation* _old_gen; | |
| 83 Generation* old_gen() { return _old_gen; } | |
| 84 | |
| 85 HeapWord *_young_old_boundary; | |
| 86 | |
| 87 int _hash_seed; | |
| 88 int _thread_num; | |
| 89 ageTable _ageTable; | |
| 90 | |
| 91 bool _to_space_full; | |
| 92 | |
| 93 int _pushes, _pops, _steals, _steal_attempts, _term_attempts; | |
| 94 int _overflow_pushes, _overflow_refills, _overflow_refill_objs; | |
| 95 | |
| 96 // Timing numbers. | |
| 97 double _start; | |
| 98 double _start_strong_roots; | |
| 99 double _strong_roots_time; | |
| 100 double _start_term; | |
| 101 double _term_time; | |
| 102 | |
| 103 // Helper for trim_queues. Scans subset of an array and makes | |
| 104 // remainder available for work stealing. | |
| 105 void scan_partial_array_and_push_remainder(oop obj); | |
| 106 | |
| 107 // In support of CMS' parallel rescan of survivor space. | |
| 108 ChunkArray* _survivor_chunk_array; | |
| 109 ChunkArray* survivor_chunk_array() { return _survivor_chunk_array; } | |
| 110 | |
| 111 void record_survivor_plab(HeapWord* plab_start, size_t plab_word_size); | |
| 112 | |
| 113 ParScanThreadState(Space* to_space_, ParNewGeneration* gen_, | |
| 114 Generation* old_gen_, int thread_num_, | |
| 115 ObjToScanQueueSet* work_queue_set_, size_t desired_plab_sz_, | |
| 116 ParallelTaskTerminator& term_); | |
| 117 | |
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118 public: |
| 0 | 119 ageTable* age_table() {return &_ageTable;} |
| 120 | |
| 121 ObjToScanQueue* work_queue() { return _work_queue; } | |
| 122 | |
| 123 ParGCAllocBuffer* to_space_alloc_buffer() { | |
| 124 return &_to_space_alloc_buffer; | |
| 125 } | |
| 126 | |
| 127 ParEvacuateFollowersClosure& evacuate_followers_closure() { return _evacuate_followers; } | |
| 128 DefNewGeneration::IsAliveClosure& is_alive_closure() { return _is_alive_closure; } | |
| 129 ParScanWeakRefClosure& scan_weak_ref_closure() { return _scan_weak_ref_closure; } | |
| 130 ParKeepAliveClosure& keep_alive_closure() { return _keep_alive_closure; } | |
| 131 ParScanClosure& older_gen_closure() { return _older_gen_closure; } | |
| 132 ParRootScanWithoutBarrierClosure& to_space_root_closure() { return _to_space_root_closure; }; | |
| 133 | |
| 134 // Decrease queue size below "max_size". | |
| 135 void trim_queues(int max_size); | |
| 136 | |
| 137 // Is new_obj a candidate for scan_partial_array_and_push_remainder method. | |
| 138 inline bool should_be_partially_scanned(oop new_obj, oop old_obj) const; | |
| 139 | |
| 140 int* hash_seed() { return &_hash_seed; } | |
| 141 int thread_num() { return _thread_num; } | |
| 142 | |
| 143 // Allocate a to-space block of size "sz", or else return NULL. | |
| 144 HeapWord* alloc_in_to_space_slow(size_t word_sz); | |
| 145 | |
| 146 HeapWord* alloc_in_to_space(size_t word_sz) { | |
| 147 HeapWord* obj = to_space_alloc_buffer()->allocate(word_sz); | |
| 148 if (obj != NULL) return obj; | |
| 149 else return alloc_in_to_space_slow(word_sz); | |
| 150 } | |
| 151 | |
| 152 HeapWord* young_old_boundary() { return _young_old_boundary; } | |
| 153 | |
| 154 void set_young_old_boundary(HeapWord *boundary) { | |
| 155 _young_old_boundary = boundary; | |
| 156 } | |
| 157 | |
| 158 // Undo the most recent allocation ("obj", of "word_sz"). | |
| 159 void undo_alloc_in_to_space(HeapWord* obj, size_t word_sz); | |
| 160 | |
| 161 int pushes() { return _pushes; } | |
| 162 int pops() { return _pops; } | |
| 163 int steals() { return _steals; } | |
| 164 int steal_attempts() { return _steal_attempts; } | |
| 165 int term_attempts() { return _term_attempts; } | |
| 166 int overflow_pushes() { return _overflow_pushes; } | |
| 167 int overflow_refills() { return _overflow_refills; } | |
| 168 int overflow_refill_objs() { return _overflow_refill_objs; } | |
| 169 | |
| 170 void note_push() { if (PAR_STATS_ENABLED) _pushes++; } | |
| 171 void note_pop() { if (PAR_STATS_ENABLED) _pops++; } | |
| 172 void note_steal() { if (PAR_STATS_ENABLED) _steals++; } | |
| 173 void note_steal_attempt() { if (PAR_STATS_ENABLED) _steal_attempts++; } | |
| 174 void note_term_attempt() { if (PAR_STATS_ENABLED) _term_attempts++; } | |
| 175 void note_overflow_push() { if (PAR_STATS_ENABLED) _overflow_pushes++; } | |
| 176 void note_overflow_refill(int objs) { | |
| 177 if (PAR_STATS_ENABLED) { | |
| 178 _overflow_refills++; | |
| 179 _overflow_refill_objs += objs; | |
| 180 } | |
| 181 } | |
| 182 | |
| 183 void start_strong_roots() { | |
| 184 _start_strong_roots = os::elapsedTime(); | |
| 185 } | |
| 186 void end_strong_roots() { | |
| 187 _strong_roots_time += (os::elapsedTime() - _start_strong_roots); | |
| 188 } | |
| 189 double strong_roots_time() { return _strong_roots_time; } | |
| 190 void start_term_time() { | |
| 191 note_term_attempt(); | |
| 192 _start_term = os::elapsedTime(); | |
| 193 } | |
| 194 void end_term_time() { | |
| 195 _term_time += (os::elapsedTime() - _start_term); | |
| 196 } | |
| 197 double term_time() { return _term_time; } | |
| 198 | |
| 199 double elapsed() { | |
| 200 return os::elapsedTime() - _start; | |
| 201 } | |
| 202 }; | |
| 203 | |
| 204 class ParNewGenTask: public AbstractGangTask { | |
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205 private: |
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206 ParNewGeneration* _gen; |
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207 Generation* _next_gen; |
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208 HeapWord* _young_old_boundary; |
| 0 | 209 class ParScanThreadStateSet* _state_set; |
| 210 | |
| 211 public: | |
| 212 ParNewGenTask(ParNewGeneration* gen, | |
| 213 Generation* next_gen, | |
| 214 HeapWord* young_old_boundary, | |
| 215 ParScanThreadStateSet* state_set); | |
| 216 | |
| 217 HeapWord* young_old_boundary() { return _young_old_boundary; } | |
| 218 | |
| 219 void work(int i); | |
| 220 }; | |
| 221 | |
| 222 class KeepAliveClosure: public DefNewGeneration::KeepAliveClosure { | |
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223 protected: |
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224 template <class T> void do_oop_work(T* p); |
| 0 | 225 public: |
| 226 KeepAliveClosure(ScanWeakRefClosure* cl); | |
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227 virtual void do_oop(oop* p); |
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228 virtual void do_oop(narrowOop* p); |
| 0 | 229 }; |
| 230 | |
| 231 class EvacuateFollowersClosureGeneral: public VoidClosure { | |
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232 private: |
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233 GenCollectedHeap* _gch; |
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234 int _level; |
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235 OopsInGenClosure* _scan_cur_or_nonheap; |
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236 OopsInGenClosure* _scan_older; |
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237 public: |
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238 EvacuateFollowersClosureGeneral(GenCollectedHeap* gch, int level, |
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239 OopsInGenClosure* cur, |
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240 OopsInGenClosure* older); |
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241 virtual void do_void(); |
| 0 | 242 }; |
| 243 | |
| 244 // Closure for scanning ParNewGeneration. | |
| 245 // Same as ScanClosure, except does parallel GC barrier. | |
| 246 class ScanClosureWithParBarrier: public ScanClosure { | |
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247 protected: |
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248 template <class T> void do_oop_work(T* p); |
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249 public: |
| 0 | 250 ScanClosureWithParBarrier(ParNewGeneration* g, bool gc_barrier); |
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251 virtual void do_oop(oop* p); |
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252 virtual void do_oop(narrowOop* p); |
| 0 | 253 }; |
| 254 | |
| 255 // Implements AbstractRefProcTaskExecutor for ParNew. | |
| 256 class ParNewRefProcTaskExecutor: public AbstractRefProcTaskExecutor { | |
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257 private: |
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258 ParNewGeneration& _generation; |
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259 ParScanThreadStateSet& _state_set; |
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260 public: |
| 0 | 261 ParNewRefProcTaskExecutor(ParNewGeneration& generation, |
| 262 ParScanThreadStateSet& state_set) | |
| 263 : _generation(generation), _state_set(state_set) | |
| 264 { } | |
| 265 | |
| 266 // Executes a task using worker threads. | |
| 267 virtual void execute(ProcessTask& task); | |
| 268 virtual void execute(EnqueueTask& task); | |
| 269 // Switch to single threaded mode. | |
| 270 virtual void set_single_threaded_mode(); | |
| 271 }; | |
| 272 | |
| 273 | |
| 274 // A Generation that does parallel young-gen collection. | |
| 275 | |
| 276 class ParNewGeneration: public DefNewGeneration { | |
| 277 friend class ParNewGenTask; | |
| 278 friend class ParNewRefProcTask; | |
| 279 friend class ParNewRefProcTaskExecutor; | |
| 280 friend class ParScanThreadStateSet; | |
| 281 | |
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282 private: |
| 0 | 283 // XXX use a global constant instead of 64! |
| 284 struct ObjToScanQueuePadded { | |
| 285 ObjToScanQueue work_queue; | |
| 286 char pad[64 - sizeof(ObjToScanQueue)]; // prevent false sharing | |
| 287 }; | |
| 288 | |
| 289 // The per-thread work queues, available here for stealing. | |
| 290 ObjToScanQueueSet* _task_queues; | |
| 291 | |
| 292 // Desired size of survivor space plab's | |
| 293 PLABStats _plab_stats; | |
| 294 | |
| 295 // A list of from-space images of to-be-scanned objects, threaded through | |
| 296 // klass-pointers (klass information already copied to the forwarded | |
| 297 // image.) Manipulated with CAS. | |
| 298 oop _overflow_list; | |
| 299 | |
| 300 // If true, older generation does not support promotion undo, so avoid. | |
| 301 static bool _avoid_promotion_undo; | |
| 302 | |
| 303 // This closure is used by the reference processor to filter out | |
| 304 // references to live referent. | |
| 305 DefNewGeneration::IsAliveClosure _is_alive_closure; | |
| 306 | |
| 307 static oop real_forwardee_slow(oop obj); | |
| 308 static void waste_some_time(); | |
| 309 | |
| 310 // Preserve the mark of "obj", if necessary, in preparation for its mark | |
| 311 // word being overwritten with a self-forwarding-pointer. | |
| 312 void preserve_mark_if_necessary(oop obj, markOop m); | |
| 313 | |
| 314 protected: | |
| 315 | |
| 316 bool _survivor_overflow; | |
| 317 | |
| 318 bool avoid_promotion_undo() { return _avoid_promotion_undo; } | |
| 319 void set_avoid_promotion_undo(bool v) { _avoid_promotion_undo = v; } | |
| 320 | |
| 321 bool survivor_overflow() { return _survivor_overflow; } | |
| 322 void set_survivor_overflow(bool v) { _survivor_overflow = v; } | |
| 323 | |
| 324 // Adjust the tenuring threshold. See the implementation for | |
| 325 // the details of the policy. | |
| 326 virtual void adjust_desired_tenuring_threshold(); | |
| 327 | |
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328 public: |
| 0 | 329 ParNewGeneration(ReservedSpace rs, size_t initial_byte_size, int level); |
| 330 | |
| 331 ~ParNewGeneration() { | |
| 332 for (uint i = 0; i < ParallelGCThreads; i++) | |
| 333 delete _task_queues->queue(i); | |
| 334 | |
| 335 delete _task_queues; | |
| 336 } | |
| 337 | |
| 338 virtual void ref_processor_init(); | |
| 339 virtual Generation::Name kind() { return Generation::ParNew; } | |
| 340 virtual const char* name() const; | |
| 341 virtual const char* short_name() const { return "ParNew"; } | |
| 342 | |
| 343 // override | |
| 344 virtual bool refs_discovery_is_mt() const { | |
| 345 assert(UseParNewGC, "ParNewGeneration only when UseParNewGC"); | |
| 346 return ParallelGCThreads > 1; | |
| 347 } | |
| 348 | |
| 349 // Make the collection virtual. | |
| 350 virtual void collect(bool full, | |
| 351 bool clear_all_soft_refs, | |
| 352 size_t size, | |
| 353 bool is_tlab); | |
| 354 | |
| 355 // This needs to be visible to the closure function. | |
| 356 // "obj" is the object to be copied, "m" is a recent value of its mark | |
| 357 // that must not contain a forwarding pointer (though one might be | |
| 358 // inserted in "obj"s mark word by a parallel thread). | |
| 359 inline oop copy_to_survivor_space(ParScanThreadState* par_scan_state, | |
| 360 oop obj, size_t obj_sz, markOop m) { | |
| 361 if (_avoid_promotion_undo) { | |
| 362 return copy_to_survivor_space_avoiding_promotion_undo(par_scan_state, | |
| 363 obj, obj_sz, m); | |
| 364 } | |
| 365 | |
| 366 return copy_to_survivor_space_with_undo(par_scan_state, obj, obj_sz, m); | |
| 367 } | |
| 368 | |
| 369 oop copy_to_survivor_space_avoiding_promotion_undo(ParScanThreadState* par_scan_state, | |
| 370 oop obj, size_t obj_sz, markOop m); | |
| 371 | |
| 372 oop copy_to_survivor_space_with_undo(ParScanThreadState* par_scan_state, | |
| 373 oop obj, size_t obj_sz, markOop m); | |
| 374 | |
| 375 // Push the given (from-space) object on the global overflow list. | |
| 376 void push_on_overflow_list(oop from_space_obj); | |
| 377 | |
| 378 // If the global overflow list is non-empty, move some tasks from it | |
| 379 // onto "work_q" (which must be empty). No more than 1/4 of the | |
| 380 // max_elems of "work_q" are moved. | |
| 381 bool take_from_overflow_list(ParScanThreadState* par_scan_state); | |
| 382 | |
| 383 // The task queues to be used by parallel GC threads. | |
| 384 ObjToScanQueueSet* task_queues() { | |
| 385 return _task_queues; | |
| 386 } | |
| 387 | |
| 388 PLABStats* plab_stats() { | |
| 389 return &_plab_stats; | |
| 390 } | |
| 391 | |
| 392 size_t desired_plab_sz() { | |
| 393 return _plab_stats.desired_plab_sz(); | |
| 394 } | |
| 395 | |
| 396 static oop real_forwardee(oop obj); | |
| 397 | |
| 398 DEBUG_ONLY(static bool is_legal_forward_ptr(oop p);) | |
| 399 }; |