1 /* 2 * Copyright (c) 2013, 2020, Red Hat, 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 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 #ifndef SHARE_GC_SHENANDOAH_SHENANDOAHHEAP_HPP 26 #define SHARE_GC_SHENANDOAH_SHENANDOAHHEAP_HPP 27 28 #include "gc/shared/markBitMap.hpp" 29 #include "gc/shared/softRefPolicy.hpp" 30 #include "gc/shared/collectedHeap.hpp" 31 #include "gc/shenandoah/shenandoahAsserts.hpp" 32 #include "gc/shenandoah/shenandoahAllocRequest.hpp" 33 #include "gc/shenandoah/shenandoahLock.hpp" 34 #include "gc/shenandoah/shenandoahEvacOOMHandler.hpp" 35 #include "gc/shenandoah/shenandoahPadding.hpp" 36 #include "gc/shenandoah/shenandoahSharedVariables.hpp" 37 #include "gc/shenandoah/shenandoahUnload.hpp" 38 #include "services/memoryManager.hpp" 39 #include "utilities/globalDefinitions.hpp" 40 41 class ConcurrentGCTimer; 42 class ReferenceProcessor; 43 class ShenandoahCollectorPolicy; 44 class ShenandoahControlThread; 45 class ShenandoahGCSession; 46 class ShenandoahGCStateResetter; 47 class ShenandoahHeuristics; 48 class ShenandoahMarkingContext; 49 class ShenandoahMarkCompact; 50 class ShenandoahMode; 51 class ShenandoahPhaseTimings; 52 class ShenandoahHeap; 53 class ShenandoahHeapRegion; 54 class ShenandoahHeapRegionClosure; 55 class ShenandoahCollectionSet; 56 class ShenandoahFreeSet; 57 class ShenandoahConcurrentMark; 58 class ShenandoahMarkCompact; 59 class ShenandoahMonitoringSupport; 60 class ShenandoahPacer; 61 class ShenandoahVerifier; 62 class ShenandoahWorkGang; 63 class VMStructs; 64 65 // Used for buffering per-region liveness data. 66 // Needed since ShenandoahHeapRegion uses atomics to update liveness. 67 // The ShenandoahHeap array has max-workers elements, each of which is an array of 68 // uint16_t * max_regions. The choice of uint16_t is not accidental: 69 // there is a tradeoff between static/dynamic footprint that translates 70 // into cache pressure (which is already high during marking), and 71 // too many atomic updates. uint32_t is too large, uint8_t is too small. 72 typedef uint16_t ShenandoahLiveData; 73 #define SHENANDOAH_LIVEDATA_MAX ((ShenandoahLiveData)-1) 74 75 class ShenandoahRegionIterator : public StackObj { 76 private: 77 ShenandoahHeap* _heap; 78 79 shenandoah_padding(0); 80 volatile size_t _index; 81 shenandoah_padding(1); 82 83 // No implicit copying: iterators should be passed by reference to capture the state 84 NONCOPYABLE(ShenandoahRegionIterator); 85 86 public: 87 ShenandoahRegionIterator(); 88 ShenandoahRegionIterator(ShenandoahHeap* heap); 89 90 // Reset iterator to default state 91 void reset(); 92 93 // Returns next region, or NULL if there are no more regions. 94 // This is multi-thread-safe. 95 inline ShenandoahHeapRegion* next(); 96 97 // This is *not* MT safe. However, in the absence of multithreaded access, it 98 // can be used to determine if there is more work to do. 99 bool has_next() const; 100 }; 101 102 class ShenandoahHeapRegionClosure : public StackObj { 103 public: 104 virtual void heap_region_do(ShenandoahHeapRegion* r) = 0; 105 virtual bool is_thread_safe() { return false; } 106 }; 107 108 #ifdef ASSERT 109 class ShenandoahAssertToSpaceClosure : public OopClosure { 110 private: 111 template <class T> 112 void do_oop_work(T* p); 113 public: 114 void do_oop(narrowOop* p); 115 void do_oop(oop* p); 116 }; 117 #endif 118 119 typedef ShenandoahLock ShenandoahHeapLock; 120 typedef ShenandoahLocker ShenandoahHeapLocker; 121 122 // Shenandoah GC is low-pause concurrent GC that uses Brooks forwarding pointers 123 // to encode forwarding data. See BrooksPointer for details on forwarding data encoding. 124 // See ShenandoahControlThread for GC cycle structure. 125 // 126 class ShenandoahHeap : public CollectedHeap { 127 friend class ShenandoahAsserts; 128 friend class VMStructs; 129 friend class ShenandoahGCSession; 130 friend class ShenandoahGCStateResetter; 131 132 // ---------- Locks that guard important data structures in Heap 133 // 134 private: 135 ShenandoahHeapLock _lock; 136 137 public: 138 ShenandoahHeapLock* lock() { 139 return &_lock; 140 } 141 142 // ---------- Initialization, termination, identification, printing routines 143 // 144 public: 145 static ShenandoahHeap* heap(); 146 147 const char* name() const { return "Shenandoah"; } 148 ShenandoahHeap::Name kind() const { return CollectedHeap::Shenandoah; } 149 150 ShenandoahHeap(ShenandoahCollectorPolicy* policy); 151 jint initialize(); 152 void post_initialize(); 153 void initialize_heuristics(); 154 155 void initialize_serviceability(); 156 157 void print_on(outputStream* st) const; 158 void print_extended_on(outputStream *st) const; 159 void print_tracing_info() const; 160 void print_heap_regions_on(outputStream* st) const; 161 162 void stop(); 163 164 void prepare_for_verify(); 165 void verify(VerifyOption vo); 166 167 // ---------- Heap counters and metrics 168 // 169 private: 170 size_t _initial_size; 171 size_t _minimum_size; 172 shenandoah_padding(0); 173 volatile size_t _used; 174 volatile size_t _committed; 175 volatile size_t _bytes_allocated_since_gc_start; 176 shenandoah_padding(1); 177 178 public: 179 void increase_used(size_t bytes); 180 void decrease_used(size_t bytes); 181 void set_used(size_t bytes); 182 183 void increase_committed(size_t bytes); 184 void decrease_committed(size_t bytes); 185 void increase_allocated(size_t bytes); 186 187 size_t bytes_allocated_since_gc_start(); 188 void reset_bytes_allocated_since_gc_start(); 189 190 size_t min_capacity() const; 191 size_t max_capacity() const; 192 size_t initial_capacity() const; 193 size_t capacity() const; 194 size_t used() const; 195 size_t committed() const; 196 197 // ---------- Workers handling 198 // 199 private: 200 uint _max_workers; 201 ShenandoahWorkGang* _workers; 202 ShenandoahWorkGang* _safepoint_workers; 203 204 public: 205 uint max_workers(); 206 void assert_gc_workers(uint nworker) NOT_DEBUG_RETURN; 207 208 WorkGang* workers() const; 209 WorkGang* get_safepoint_workers(); 210 211 void gc_threads_do(ThreadClosure* tcl) const; 212 213 // ---------- Heap regions handling machinery 214 // 215 private: 216 MemRegion _heap_region; 217 bool _heap_region_special; 218 size_t _num_regions; 219 ShenandoahHeapRegion** _regions; 220 ShenandoahRegionIterator _update_refs_iterator; 221 222 public: 223 224 inline HeapWord* base() const { return _heap_region.start(); } 225 226 inline size_t num_regions() const { return _num_regions; } 227 inline bool is_heap_region_special() { return _heap_region_special; } 228 229 inline ShenandoahHeapRegion* const heap_region_containing(const void* addr) const; 230 inline size_t heap_region_index_containing(const void* addr) const; 231 232 inline ShenandoahHeapRegion* const get_region(size_t region_idx) const; 233 234 void heap_region_iterate(ShenandoahHeapRegionClosure* blk) const; 235 void parallel_heap_region_iterate(ShenandoahHeapRegionClosure* blk) const; 236 237 // ---------- GC state machinery 238 // 239 // GC state describes the important parts of collector state, that may be 240 // used to make barrier selection decisions in the native and generated code. 241 // Multiple bits can be set at once. 242 // 243 // Important invariant: when GC state is zero, the heap is stable, and no barriers 244 // are required. 245 // 246 public: 247 enum GCStateBitPos { 248 // Heap has forwarded objects: needs LRB barriers. 249 HAS_FORWARDED_BITPOS = 0, 250 251 // Heap is under marking: needs SATB barriers. 252 MARKING_BITPOS = 1, 253 254 // Heap is under evacuation: needs LRB barriers. (Set together with HAS_FORWARDED) 255 EVACUATION_BITPOS = 2, 256 257 // Heap is under updating: needs no additional barriers. 258 UPDATEREFS_BITPOS = 3, 259 }; 260 261 enum GCState { 262 STABLE = 0, 263 HAS_FORWARDED = 1 << HAS_FORWARDED_BITPOS, 264 MARKING = 1 << MARKING_BITPOS, 265 EVACUATION = 1 << EVACUATION_BITPOS, 266 UPDATEREFS = 1 << UPDATEREFS_BITPOS, 267 }; 268 269 private: 270 ShenandoahSharedBitmap _gc_state; 271 ShenandoahSharedFlag _degenerated_gc_in_progress; 272 ShenandoahSharedFlag _full_gc_in_progress; 273 ShenandoahSharedFlag _full_gc_move_in_progress; 274 ShenandoahSharedFlag _progress_last_gc; 275 ShenandoahSharedFlag _concurrent_strong_root_in_progress; 276 ShenandoahSharedFlag _concurrent_weak_root_in_progress; 277 278 void set_gc_state_all_threads(char state); 279 void set_gc_state_mask(uint mask, bool value); 280 281 public: 282 char gc_state() const; 283 static address gc_state_addr(); 284 285 void set_concurrent_mark_in_progress(bool in_progress); 286 void set_evacuation_in_progress(bool in_progress); 287 void set_update_refs_in_progress(bool in_progress); 288 void set_degenerated_gc_in_progress(bool in_progress); 289 void set_full_gc_in_progress(bool in_progress); 290 void set_full_gc_move_in_progress(bool in_progress); 291 void set_has_forwarded_objects(bool cond); 292 void set_concurrent_strong_root_in_progress(bool cond); 293 void set_concurrent_weak_root_in_progress(bool cond); 294 295 inline bool is_stable() const; 296 inline bool is_idle() const; 297 inline bool is_concurrent_mark_in_progress() const; 298 inline bool is_update_refs_in_progress() const; 299 inline bool is_evacuation_in_progress() const; 300 inline bool is_degenerated_gc_in_progress() const; 301 inline bool is_full_gc_in_progress() const; 302 inline bool is_full_gc_move_in_progress() const; 303 inline bool has_forwarded_objects() const; 304 inline bool is_gc_in_progress_mask(uint mask) const; 305 inline bool is_stw_gc_in_progress() const; 306 inline bool is_concurrent_strong_root_in_progress() const; 307 inline bool is_concurrent_weak_root_in_progress() const; 308 309 // ---------- GC cancellation and degeneration machinery 310 // 311 // Cancelled GC flag is used to notify concurrent phases that they should terminate. 312 // 313 public: 314 enum ShenandoahDegenPoint { 315 _degenerated_unset, 316 _degenerated_outside_cycle, 317 _degenerated_mark, 318 _degenerated_evac, 319 _degenerated_updaterefs, 320 _DEGENERATED_LIMIT 321 }; 322 323 static const char* degen_point_to_string(ShenandoahDegenPoint point) { 324 switch (point) { 325 case _degenerated_unset: 326 return "<UNSET>"; 327 case _degenerated_outside_cycle: 328 return "Outside of Cycle"; 329 case _degenerated_mark: 330 return "Mark"; 331 case _degenerated_evac: 332 return "Evacuation"; 333 case _degenerated_updaterefs: 334 return "Update Refs"; 335 default: 336 ShouldNotReachHere(); 337 return "ERROR"; 338 } 339 }; 340 341 private: 342 enum CancelState { 343 // Normal state. GC has not been cancelled and is open for cancellation. 344 // Worker threads can suspend for safepoint. 345 CANCELLABLE, 346 347 // GC has been cancelled. Worker threads can not suspend for 348 // safepoint but must finish their work as soon as possible. 349 CANCELLED, 350 351 // GC has not been cancelled and must not be cancelled. At least 352 // one worker thread checks for pending safepoint and may suspend 353 // if a safepoint is pending. 354 NOT_CANCELLED 355 }; 356 357 ShenandoahSharedEnumFlag<CancelState> _cancelled_gc; 358 bool try_cancel_gc(); 359 360 public: 361 static address cancelled_gc_addr(); 362 363 inline bool cancelled_gc() const; 364 inline bool check_cancelled_gc_and_yield(bool sts_active = true); 365 366 inline void clear_cancelled_gc(); 367 368 void cancel_gc(GCCause::Cause cause); 369 370 // ---------- GC operations entry points 371 // 372 public: 373 // Entry points to STW GC operations, these cause a related safepoint, that then 374 // call the entry method below 375 void vmop_entry_init_mark(); 376 void vmop_entry_final_mark(); 377 void vmop_entry_init_updaterefs(); 378 void vmop_entry_final_updaterefs(); 379 void vmop_entry_full(GCCause::Cause cause); 380 void vmop_degenerated(ShenandoahDegenPoint point); 381 382 // Entry methods to normally STW GC operations. These set up logging, monitoring 383 // and workers for net VM operation 384 void entry_init_mark(); 385 void entry_final_mark(); 386 void entry_init_updaterefs(); 387 void entry_final_updaterefs(); 388 void entry_full(GCCause::Cause cause); 389 void entry_degenerated(int point); 390 391 // Entry methods to normally concurrent GC operations. These set up logging, monitoring 392 // for concurrent operation. 393 void entry_reset(); 394 void entry_mark(); 395 void entry_preclean(); 396 void entry_weak_roots(); 397 void entry_class_unloading(); 398 void entry_strong_roots(); 399 void entry_cleanup_early(); 400 void entry_evac(); 401 void entry_updaterefs(); 402 void entry_cleanup_complete(); 403 void entry_uncommit(double shrink_before); 404 405 private: 406 // Actual work for the phases 407 void op_init_mark(); 408 void op_final_mark(); 409 void op_init_updaterefs(); 410 void op_final_updaterefs(); 411 void op_full(GCCause::Cause cause); 412 void op_degenerated(ShenandoahDegenPoint point); 413 void op_degenerated_fail(); 414 void op_degenerated_futile(); 415 416 void op_reset(); 417 void op_mark(); 418 void op_preclean(); 419 void op_weak_roots(); 420 void op_class_unloading(); 421 void op_strong_roots(); 422 void op_cleanup_early(); 423 void op_conc_evac(); 424 void op_stw_evac(); 425 void op_updaterefs(); 426 void op_cleanup_complete(); 427 void op_uncommit(double shrink_before); 428 429 // Messages for GC trace events, they have to be immortal for 430 // passing around the logging/tracing systems 431 const char* init_mark_event_message() const; 432 const char* final_mark_event_message() const; 433 const char* conc_mark_event_message() const; 434 const char* degen_event_message(ShenandoahDegenPoint point) const; 435 436 // ---------- GC subsystems 437 // 438 private: 439 ShenandoahControlThread* _control_thread; 440 ShenandoahCollectorPolicy* _shenandoah_policy; 441 ShenandoahMode* _gc_mode; 442 ShenandoahHeuristics* _heuristics; 443 ShenandoahFreeSet* _free_set; 444 ShenandoahConcurrentMark* _scm; 445 ShenandoahMarkCompact* _full_gc; 446 ShenandoahPacer* _pacer; 447 ShenandoahVerifier* _verifier; 448 449 ShenandoahPhaseTimings* _phase_timings; 450 451 ShenandoahControlThread* control_thread() { return _control_thread; } 452 ShenandoahMarkCompact* full_gc() { return _full_gc; } 453 454 public: 455 ShenandoahCollectorPolicy* shenandoah_policy() const { return _shenandoah_policy; } 456 ShenandoahMode* mode() const { return _gc_mode; } 457 ShenandoahHeuristics* heuristics() const { return _heuristics; } 458 ShenandoahFreeSet* free_set() const { return _free_set; } 459 ShenandoahConcurrentMark* concurrent_mark() { return _scm; } 460 ShenandoahPacer* pacer() const { return _pacer; } 461 462 ShenandoahPhaseTimings* phase_timings() const { return _phase_timings; } 463 464 ShenandoahVerifier* verifier(); 465 466 // ---------- VM subsystem bindings 467 // 468 private: 469 ShenandoahMonitoringSupport* _monitoring_support; 470 MemoryPool* _memory_pool; 471 GCMemoryManager _stw_memory_manager; 472 GCMemoryManager _cycle_memory_manager; 473 ConcurrentGCTimer* _gc_timer; 474 SoftRefPolicy _soft_ref_policy; 475 476 // For exporting to SA 477 int _log_min_obj_alignment_in_bytes; 478 public: 479 ShenandoahMonitoringSupport* monitoring_support() { return _monitoring_support; } 480 GCMemoryManager* cycle_memory_manager() { return &_cycle_memory_manager; } 481 GCMemoryManager* stw_memory_manager() { return &_stw_memory_manager; } 482 SoftRefPolicy* soft_ref_policy() { return &_soft_ref_policy; } 483 484 GrowableArray<GCMemoryManager*> memory_managers(); 485 GrowableArray<MemoryPool*> memory_pools(); 486 MemoryUsage memory_usage(); 487 GCTracer* tracer(); 488 ConcurrentGCTimer* gc_timer() const; 489 490 // ---------- Reference processing 491 // 492 private: 493 AlwaysTrueClosure _subject_to_discovery; 494 ReferenceProcessor* _ref_processor; 495 ShenandoahSharedFlag _process_references; 496 bool _ref_proc_mt_discovery; 497 bool _ref_proc_mt_processing; 498 499 void ref_processing_init(); 500 501 public: 502 ReferenceProcessor* ref_processor() { return _ref_processor; } 503 bool ref_processor_mt_discovery() { return _ref_proc_mt_discovery; } 504 bool ref_processor_mt_processing() { return _ref_proc_mt_processing; } 505 void set_process_references(bool pr); 506 bool process_references() const; 507 508 // ---------- Class Unloading 509 // 510 private: 511 ShenandoahSharedFlag _unload_classes; 512 ShenandoahUnload _unloader; 513 514 public: 515 void set_unload_classes(bool uc); 516 bool unload_classes() const; 517 518 // Perform STW class unloading and weak root cleaning 519 void parallel_cleaning(bool full_gc); 520 521 private: 522 void stw_unload_classes(bool full_gc); 523 void stw_process_weak_roots(bool full_gc); 524 525 // Prepare concurrent root processing 526 void prepare_concurrent_roots(); 527 // Prepare and finish concurrent unloading 528 void prepare_concurrent_unloading(); 529 void finish_concurrent_unloading(); 530 531 // ---------- Generic interface hooks 532 // Minor things that super-interface expects us to implement to play nice with 533 // the rest of runtime. Some of the things here are not required to be implemented, 534 // and can be stubbed out. 535 // 536 public: 537 AdaptiveSizePolicy* size_policy() shenandoah_not_implemented_return(NULL); 538 bool is_maximal_no_gc() const shenandoah_not_implemented_return(false); 539 540 bool is_in(const void* p) const; 541 542 MemRegion reserved_region() const { return _reserved; } 543 bool is_in_reserved(const void* addr) const { return _reserved.contains(addr); } 544 545 void collect(GCCause::Cause cause); 546 void do_full_collection(bool clear_all_soft_refs); 547 548 // Used for parsing heap during error printing 549 HeapWord* block_start(const void* addr) const; 550 bool block_is_obj(const HeapWord* addr) const; 551 bool print_location(outputStream* st, void* addr) const; 552 553 // Used for native heap walkers: heap dumpers, mostly 554 void object_iterate(ObjectClosure* cl); 555 556 // Keep alive an object that was loaded with AS_NO_KEEPALIVE. 557 void keep_alive(oop obj); 558 559 // Used by RMI 560 jlong millis_since_last_gc(); 561 562 // ---------- Safepoint interface hooks 563 // 564 public: 565 void safepoint_synchronize_begin(); 566 void safepoint_synchronize_end(); 567 568 // ---------- Code roots handling hooks 569 // 570 public: 571 void register_nmethod(nmethod* nm); 572 void unregister_nmethod(nmethod* nm); 573 void flush_nmethod(nmethod* nm); 574 void verify_nmethod(nmethod* nm) {} 575 576 // ---------- Pinning hooks 577 // 578 public: 579 // Shenandoah supports per-object (per-region) pinning 580 bool supports_object_pinning() const { return true; } 581 582 oop pin_object(JavaThread* thread, oop obj); 583 void unpin_object(JavaThread* thread, oop obj); 584 585 void sync_pinned_region_status(); 586 void assert_pinned_region_status() NOT_DEBUG_RETURN; 587 588 // ---------- Allocation support 589 // 590 private: 591 HeapWord* allocate_memory_under_lock(ShenandoahAllocRequest& request, bool& in_new_region); 592 inline HeapWord* allocate_from_gclab(Thread* thread, size_t size); 593 HeapWord* allocate_from_gclab_slow(Thread* thread, size_t size); 594 HeapWord* allocate_new_gclab(size_t min_size, size_t word_size, size_t* actual_size); 595 596 public: 597 HeapWord* allocate_memory(ShenandoahAllocRequest& request); 598 HeapWord* mem_allocate(size_t size, bool* what); 599 MetaWord* satisfy_failed_metadata_allocation(ClassLoaderData* loader_data, 600 size_t size, 601 Metaspace::MetadataType mdtype); 602 603 void notify_mutator_alloc_words(size_t words, bool waste); 604 605 // Shenandoah supports TLAB allocation 606 bool supports_tlab_allocation() const { return true; } 607 608 HeapWord* allocate_new_tlab(size_t min_size, size_t requested_size, size_t* actual_size); 609 size_t tlab_capacity(Thread *thr) const; 610 size_t unsafe_max_tlab_alloc(Thread *thread) const; 611 size_t max_tlab_size() const; 612 size_t tlab_used(Thread* ignored) const; 613 614 void ensure_parsability(bool retire_labs); 615 616 void labs_make_parsable(); 617 void tlabs_retire(bool resize); 618 void gclabs_retire(bool resize); 619 620 // Runs the given AbstractGangTask with the current active workers. 621 // Returns the total time to run the task. 622 virtual void run_task(AbstractGangTask* task); 623 624 // ---------- Marking support 625 // 626 private: 627 ShenandoahMarkingContext* _marking_context; 628 MemRegion _bitmap_region; 629 MemRegion _aux_bitmap_region; 630 MarkBitMap _verification_bit_map; 631 MarkBitMap _aux_bit_map; 632 633 size_t _bitmap_size; 634 size_t _bitmap_regions_per_slice; 635 size_t _bitmap_bytes_per_slice; 636 637 size_t _pretouch_heap_page_size; 638 size_t _pretouch_bitmap_page_size; 639 640 bool _bitmap_region_special; 641 bool _aux_bitmap_region_special; 642 643 ShenandoahLiveData** _liveness_cache; 644 645 public: 646 inline ShenandoahMarkingContext* complete_marking_context() const; 647 inline ShenandoahMarkingContext* marking_context() const; 648 inline void mark_complete_marking_context(); 649 inline void mark_incomplete_marking_context(); 650 651 template<class T> 652 inline void marked_object_iterate(ShenandoahHeapRegion* region, T* cl); 653 654 template<class T> 655 inline void marked_object_iterate(ShenandoahHeapRegion* region, T* cl, HeapWord* limit); 656 657 template<class T> 658 inline void marked_object_oop_iterate(ShenandoahHeapRegion* region, T* cl, HeapWord* limit); 659 660 void reset_mark_bitmap(); 661 662 // SATB barriers hooks 663 inline bool requires_marking(const void* entry) const; 664 void force_satb_flush_all_threads(); 665 666 // Support for bitmap uncommits 667 bool commit_bitmap_slice(ShenandoahHeapRegion *r); 668 bool uncommit_bitmap_slice(ShenandoahHeapRegion *r); 669 bool is_bitmap_slice_committed(ShenandoahHeapRegion* r, bool skip_self = false); 670 671 // Liveness caching support 672 ShenandoahLiveData* get_liveness_cache(uint worker_id); 673 void flush_liveness_cache(uint worker_id); 674 675 size_t pretouch_heap_page_size() { return _pretouch_heap_page_size; } 676 677 // ---------- Evacuation support 678 // 679 private: 680 ShenandoahCollectionSet* _collection_set; 681 ShenandoahEvacOOMHandler _oom_evac_handler; 682 683 void evacuate_and_update_roots(); 684 685 public: 686 static address in_cset_fast_test_addr(); 687 688 ShenandoahCollectionSet* collection_set() const { return _collection_set; } 689 690 // Checks if object is in the collection set. 691 inline bool in_collection_set(oop obj) const; 692 693 // Checks if location is in the collection set. Can be interior pointer, not the oop itself. 694 inline bool in_collection_set_loc(void* loc) const; 695 696 // Evacuates object src. Returns the evacuated object, either evacuated 697 // by this thread, or by some other thread. 698 inline oop evacuate_object(oop src, Thread* thread); 699 700 // Call before/after evacuation. 701 inline void enter_evacuation(Thread* t); 702 inline void leave_evacuation(Thread* t); 703 704 // ---------- Helper functions 705 // 706 public: 707 template <class T> 708 inline oop evac_update_with_forwarded(T* p); 709 710 template <class T> 711 inline oop maybe_update_with_forwarded(T* p); 712 713 template <class T> 714 inline oop maybe_update_with_forwarded_not_null(T* p, oop obj); 715 716 template <class T> 717 inline oop update_with_forwarded_not_null(T* p, oop obj); 718 719 static inline oop cas_oop(oop n, narrowOop* addr, oop c); 720 static inline oop cas_oop(oop n, oop* addr, oop c); 721 static inline oop cas_oop(oop n, narrowOop* addr, narrowOop c); 722 723 void trash_humongous_region_at(ShenandoahHeapRegion *r); 724 725 void deduplicate_string(oop str); 726 727 private: 728 void trash_cset_regions(); 729 void update_heap_references(bool concurrent); 730 731 // ---------- Testing helpers functions 732 // 733 private: 734 ShenandoahSharedFlag _inject_alloc_failure; 735 736 void try_inject_alloc_failure(); 737 bool should_inject_alloc_failure(); 738 }; 739 740 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHHEAP_HPP