1 /* 2 * Copyright (c) 2013, 2019, Red Hat, Inc. All rights reserved. 3 * 4 * This code is free software; you can redistribute it and/or modify it 5 * under the terms of the GNU General Public License version 2 only, as 6 * published by the Free Software Foundation. 7 * 8 * This code is distributed in the hope that it will be useful, but WITHOUT 9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 11 * version 2 for more details (a copy is included in the LICENSE file that 12 * accompanied this code). 13 * 14 * You should have received a copy of the GNU General Public License version 15 * 2 along with this work; if not, write to the Free Software Foundation, 16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 17 * 18 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 19 * or visit www.oracle.com if you need additional information or have any 20 * questions. 21 * 22 */ 23 24 #ifndef SHARE_GC_SHENANDOAH_SHENANDOAHHEAP_HPP 25 #define SHARE_GC_SHENANDOAH_SHENANDOAHHEAP_HPP 26 27 #include "gc/shared/markBitMap.hpp" 28 #include "gc/shared/softRefPolicy.hpp" 29 #include "gc/shared/collectedHeap.hpp" 30 #include "gc/shenandoah/shenandoahAsserts.hpp" 31 #include "gc/shenandoah/shenandoahAllocRequest.hpp" 32 #include "gc/shenandoah/shenandoahLock.hpp" 33 #include "gc/shenandoah/shenandoahEvacOOMHandler.hpp" 34 #include "gc/shenandoah/shenandoahSharedVariables.hpp" 35 #include "memory/metaspace/metaspaceEnums.hpp" 36 #include "services/memoryManager.hpp" 37 38 class ConcurrentGCTimer; 39 class ReferenceProcessor; 40 class ShenandoahAllocTracker; 41 class ShenandoahCollectorPolicy; 42 class ShenandoahControlThread; 43 class ShenandoahGCSession; 44 class ShenandoahGCStateResetter; 45 class ShenandoahHeuristics; 46 class ShenandoahMarkingContext; 47 class ShenandoahMode; 48 class ShenandoahPhaseTimings; 49 class ShenandoahHeap; 50 class ShenandoahHeapRegion; 51 class ShenandoahHeapRegionClosure; 52 class ShenandoahCollectionSet; 53 class ShenandoahFreeSet; 54 class ShenandoahConcurrentMark; 55 class ShenandoahMarkCompact; 56 class ShenandoahMonitoringSupport; 57 class ShenandoahPacer; 58 class ShenandoahTraversalGC; 59 class ShenandoahVerifier; 60 class ShenandoahWorkGang; 61 class VMStructs; 62 63 class ShenandoahRegionIterator : public StackObj { 64 private: 65 ShenandoahHeap* _heap; 66 67 DEFINE_PAD_MINUS_SIZE(0, DEFAULT_CACHE_LINE_SIZE, sizeof(volatile size_t)); 68 volatile size_t _index; 69 DEFINE_PAD_MINUS_SIZE(1, DEFAULT_CACHE_LINE_SIZE, 0); 70 71 // No implicit copying: iterators should be passed by reference to capture the state 72 ShenandoahRegionIterator(const ShenandoahRegionIterator& that); 73 ShenandoahRegionIterator& operator=(const ShenandoahRegionIterator& o); 74 75 public: 76 ShenandoahRegionIterator(); 77 ShenandoahRegionIterator(ShenandoahHeap* heap); 78 79 // Reset iterator to default state 80 void reset(); 81 82 // Returns next region, or NULL if there are no more regions. 83 // This is multi-thread-safe. 84 inline ShenandoahHeapRegion* next(); 85 86 // This is *not* MT safe. However, in the absence of multithreaded access, it 87 // can be used to determine if there is more work to do. 88 bool has_next() const; 89 }; 90 91 class ShenandoahHeapRegionClosure : public StackObj { 92 public: 93 virtual void heap_region_do(ShenandoahHeapRegion* r) = 0; 94 virtual bool is_thread_safe() { return false; } 95 }; 96 97 #ifdef ASSERT 98 class ShenandoahAssertToSpaceClosure : public OopClosure { 99 private: 100 template <class T> 101 void do_oop_work(T* p); 102 public: 103 void do_oop(narrowOop* p); 104 void do_oop(oop* p); 105 }; 106 #endif 107 108 typedef ShenandoahLock ShenandoahHeapLock; 109 typedef ShenandoahLocker ShenandoahHeapLocker; 110 111 // Shenandoah GC is low-pause concurrent GC that uses Brooks forwarding pointers 112 // to encode forwarding data. See BrooksPointer for details on forwarding data encoding. 113 // See ShenandoahControlThread for GC cycle structure. 114 // 115 class ShenandoahHeap : public CollectedHeap { 116 friend class ShenandoahAsserts; 117 friend class VMStructs; 118 friend class ShenandoahGCSession; 119 friend class ShenandoahGCStateResetter; 120 121 // ---------- Locks that guard important data structures in Heap 122 // 123 private: 124 ShenandoahHeapLock _lock; 125 126 public: 127 ShenandoahHeapLock* lock() { 128 return &_lock; 129 } 130 131 void assert_heaplock_owned_by_current_thread() NOT_DEBUG_RETURN; 132 void assert_heaplock_not_owned_by_current_thread() NOT_DEBUG_RETURN; 133 void assert_heaplock_or_safepoint() NOT_DEBUG_RETURN; 134 135 // ---------- Initialization, termination, identification, printing routines 136 // 137 public: 138 static ShenandoahHeap* heap(); 139 static ShenandoahHeap* heap_no_check(); 140 141 const char* name() const { return "Shenandoah"; } 142 ShenandoahHeap::Name kind() const { return CollectedHeap::Shenandoah; } 143 144 ShenandoahHeap(ShenandoahCollectorPolicy* policy); 145 jint initialize(); 146 void post_initialize(); 147 void initialize_heuristics(); 148 149 void initialize_serviceability(); 150 151 void print_on(outputStream* st) const; 152 void print_extended_on(outputStream *st) const; 153 void print_tracing_info() const; 154 void print_gc_threads_on(outputStream* st) const; 155 void print_heap_regions_on(outputStream* st) const; 156 157 void stop(); 158 159 void prepare_for_verify(); 160 void verify(VerifyOption vo); 161 162 // ---------- Heap counters and metrics 163 // 164 private: 165 size_t _initial_size; 166 size_t _minimum_size; 167 DEFINE_PAD_MINUS_SIZE(0, DEFAULT_CACHE_LINE_SIZE, sizeof(volatile size_t)); 168 volatile size_t _used; 169 volatile size_t _committed; 170 volatile size_t _bytes_allocated_since_gc_start; 171 DEFINE_PAD_MINUS_SIZE(1, DEFAULT_CACHE_LINE_SIZE, 0); 172 173 public: 174 void increase_used(size_t bytes); 175 void decrease_used(size_t bytes); 176 void set_used(size_t bytes); 177 178 void increase_committed(size_t bytes); 179 void decrease_committed(size_t bytes); 180 void increase_allocated(size_t bytes); 181 182 size_t bytes_allocated_since_gc_start(); 183 void reset_bytes_allocated_since_gc_start(); 184 185 size_t min_capacity() const; 186 size_t max_capacity() const; 187 size_t initial_capacity() const; 188 size_t capacity() const; 189 size_t used() const; 190 size_t committed() const; 191 192 // ---------- Workers handling 193 // 194 private: 195 uint _max_workers; 196 ShenandoahWorkGang* _workers; 197 ShenandoahWorkGang* _safepoint_workers; 198 199 public: 200 uint max_workers(); 201 void assert_gc_workers(uint nworker) NOT_DEBUG_RETURN; 202 203 WorkGang* workers() const; 204 WorkGang* get_safepoint_workers(); 205 206 void gc_threads_do(ThreadClosure* tcl) const; 207 208 // ---------- Heap regions handling machinery 209 // 210 private: 211 MemRegion _heap_region; 212 bool _heap_region_special; 213 size_t _num_regions; 214 ShenandoahHeapRegion** _regions; 215 ShenandoahRegionIterator _update_refs_iterator; 216 217 public: 218 inline size_t num_regions() const { return _num_regions; } 219 inline bool is_heap_region_special() { return _heap_region_special; } 220 221 inline ShenandoahHeapRegion* const heap_region_containing(const void* addr) const; 222 inline size_t heap_region_index_containing(const void* addr) const; 223 224 inline ShenandoahHeapRegion* const get_region(size_t region_idx) const; 225 226 void heap_region_iterate(ShenandoahHeapRegionClosure* blk) const; 227 void parallel_heap_region_iterate(ShenandoahHeapRegionClosure* blk) const; 228 229 // ---------- GC state machinery 230 // 231 // GC state describes the important parts of collector state, that may be 232 // used to make barrier selection decisions in the native and generated code. 233 // Multiple bits can be set at once. 234 // 235 // Important invariant: when GC state is zero, the heap is stable, and no barriers 236 // are required. 237 // 238 public: 239 enum GCStateBitPos { 240 // Heap has forwarded objects: needs LRB barriers. 241 HAS_FORWARDED_BITPOS = 0, 242 243 // Heap is under marking: needs SATB barriers. 244 MARKING_BITPOS = 1, 245 246 // Heap is under evacuation: needs LRB barriers. (Set together with HAS_FORWARDED) 247 EVACUATION_BITPOS = 2, 248 249 // Heap is under updating: needs no additional barriers. 250 UPDATEREFS_BITPOS = 3, 251 252 // Heap is under traversal collection 253 TRAVERSAL_BITPOS = 4 254 }; 255 256 enum GCState { 257 STABLE = 0, 258 HAS_FORWARDED = 1 << HAS_FORWARDED_BITPOS, 259 MARKING = 1 << MARKING_BITPOS, 260 EVACUATION = 1 << EVACUATION_BITPOS, 261 UPDATEREFS = 1 << UPDATEREFS_BITPOS, 262 TRAVERSAL = 1 << TRAVERSAL_BITPOS 263 }; 264 265 private: 266 ShenandoahSharedBitmap _gc_state; 267 ShenandoahSharedFlag _degenerated_gc_in_progress; 268 ShenandoahSharedFlag _full_gc_in_progress; 269 ShenandoahSharedFlag _full_gc_move_in_progress; 270 ShenandoahSharedFlag _progress_last_gc; 271 272 void set_gc_state_all_threads(char state); 273 void set_gc_state_mask(uint mask, bool value); 274 275 public: 276 char gc_state() const; 277 static address gc_state_addr(); 278 279 void set_concurrent_mark_in_progress(bool in_progress); 280 void set_evacuation_in_progress(bool in_progress); 281 void set_update_refs_in_progress(bool in_progress); 282 void set_degenerated_gc_in_progress(bool in_progress); 283 void set_full_gc_in_progress(bool in_progress); 284 void set_full_gc_move_in_progress(bool in_progress); 285 void set_concurrent_traversal_in_progress(bool in_progress); 286 void set_has_forwarded_objects(bool cond); 287 288 inline bool is_stable() const; 289 inline bool is_idle() const; 290 inline bool is_concurrent_mark_in_progress() const; 291 inline bool is_update_refs_in_progress() const; 292 inline bool is_evacuation_in_progress() const; 293 inline bool is_degenerated_gc_in_progress() const; 294 inline bool is_full_gc_in_progress() const; 295 inline bool is_full_gc_move_in_progress() const; 296 inline bool is_concurrent_traversal_in_progress() const; 297 inline bool has_forwarded_objects() const; 298 inline bool is_gc_in_progress_mask(uint mask) const; 299 300 // ---------- GC cancellation and degeneration machinery 301 // 302 // Cancelled GC flag is used to notify concurrent phases that they should terminate. 303 // 304 public: 305 enum ShenandoahDegenPoint { 306 _degenerated_unset, 307 _degenerated_traversal, 308 _degenerated_outside_cycle, 309 _degenerated_mark, 310 _degenerated_evac, 311 _degenerated_updaterefs, 312 _DEGENERATED_LIMIT 313 }; 314 315 static const char* degen_point_to_string(ShenandoahDegenPoint point) { 316 switch (point) { 317 case _degenerated_unset: 318 return "<UNSET>"; 319 case _degenerated_traversal: 320 return "Traversal"; 321 case _degenerated_outside_cycle: 322 return "Outside of Cycle"; 323 case _degenerated_mark: 324 return "Mark"; 325 case _degenerated_evac: 326 return "Evacuation"; 327 case _degenerated_updaterefs: 328 return "Update Refs"; 329 default: 330 ShouldNotReachHere(); 331 return "ERROR"; 332 } 333 }; 334 335 private: 336 enum CancelState { 337 // Normal state. GC has not been cancelled and is open for cancellation. 338 // Worker threads can suspend for safepoint. 339 CANCELLABLE, 340 341 // GC has been cancelled. Worker threads can not suspend for 342 // safepoint but must finish their work as soon as possible. 343 CANCELLED, 344 345 // GC has not been cancelled and must not be cancelled. At least 346 // one worker thread checks for pending safepoint and may suspend 347 // if a safepoint is pending. 348 NOT_CANCELLED 349 }; 350 351 ShenandoahSharedEnumFlag<CancelState> _cancelled_gc; 352 bool try_cancel_gc(); 353 354 public: 355 static address cancelled_gc_addr(); 356 357 inline bool cancelled_gc() const; 358 inline bool check_cancelled_gc_and_yield(bool sts_active = true); 359 360 inline void clear_cancelled_gc(); 361 362 void cancel_gc(GCCause::Cause cause); 363 364 // ---------- GC operations entry points 365 // 366 public: 367 // Entry points to STW GC operations, these cause a related safepoint, that then 368 // call the entry method below 369 void vmop_entry_init_mark(); 370 void vmop_entry_final_mark(); 371 void vmop_entry_final_evac(); 372 void vmop_entry_init_updaterefs(); 373 void vmop_entry_final_updaterefs(); 374 void vmop_entry_init_traversal(); 375 void vmop_entry_final_traversal(); 376 void vmop_entry_full(GCCause::Cause cause); 377 void vmop_degenerated(ShenandoahDegenPoint point); 378 379 // Entry methods to normally STW GC operations. These set up logging, monitoring 380 // and workers for net VM operation 381 void entry_init_mark(); 382 void entry_final_mark(); 383 void entry_final_evac(); 384 void entry_init_updaterefs(); 385 void entry_final_updaterefs(); 386 void entry_init_traversal(); 387 void entry_final_traversal(); 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_roots(); 397 void entry_cleanup(); 398 void entry_evac(); 399 void entry_updaterefs(); 400 void entry_traversal(); 401 void entry_uncommit(double shrink_before); 402 403 private: 404 // Actual work for the phases 405 void op_init_mark(); 406 void op_final_mark(); 407 void op_final_evac(); 408 void op_init_updaterefs(); 409 void op_final_updaterefs(); 410 void op_init_traversal(); 411 void op_final_traversal(); 412 void op_full(GCCause::Cause cause); 413 void op_degenerated(ShenandoahDegenPoint point); 414 void op_degenerated_fail(); 415 void op_degenerated_futile(); 416 417 void op_reset(); 418 void op_mark(); 419 void op_preclean(); 420 void op_roots(); 421 void op_cleanup(); 422 void op_conc_evac(); 423 void op_stw_evac(); 424 void op_updaterefs(); 425 void op_traversal(); 426 void op_uncommit(double shrink_before); 427 428 // Messages for GC trace events, they have to be immortal for 429 // passing around the logging/tracing systems 430 const char* init_mark_event_message() const; 431 const char* final_mark_event_message() const; 432 const char* conc_mark_event_message() const; 433 const char* degen_event_message(ShenandoahDegenPoint point) const; 434 435 // ---------- GC subsystems 436 // 437 private: 438 ShenandoahControlThread* _control_thread; 439 ShenandoahCollectorPolicy* _shenandoah_policy; 440 ShenandoahMode* _gc_mode; 441 ShenandoahHeuristics* _heuristics; 442 ShenandoahFreeSet* _free_set; 443 ShenandoahConcurrentMark* _scm; 444 ShenandoahTraversalGC* _traversal_gc; 445 ShenandoahMarkCompact* _full_gc; 446 ShenandoahPacer* _pacer; 447 ShenandoahVerifier* _verifier; 448 449 ShenandoahAllocTracker* _alloc_tracker; 450 ShenandoahPhaseTimings* _phase_timings; 451 452 ShenandoahControlThread* control_thread() { return _control_thread; } 453 ShenandoahMarkCompact* full_gc() { return _full_gc; } 454 455 public: 456 ShenandoahCollectorPolicy* shenandoah_policy() const { return _shenandoah_policy; } 457 ShenandoahHeuristics* heuristics() const { return _heuristics; } 458 ShenandoahFreeSet* free_set() const { return _free_set; } 459 ShenandoahConcurrentMark* concurrent_mark() { return _scm; } 460 ShenandoahTraversalGC* traversal_gc() const { return _traversal_gc; } 461 bool is_traversal_mode() const { return _traversal_gc != NULL; } 462 ShenandoahPacer* pacer() const { return _pacer; } 463 464 ShenandoahPhaseTimings* phase_timings() const { return _phase_timings; } 465 ShenandoahAllocTracker* alloc_tracker() const { return _alloc_tracker; } 466 467 ShenandoahVerifier* verifier(); 468 469 // ---------- VM subsystem bindings 470 // 471 private: 472 ShenandoahMonitoringSupport* _monitoring_support; 473 MemoryPool* _memory_pool; 474 GCMemoryManager _stw_memory_manager; 475 GCMemoryManager _cycle_memory_manager; 476 ConcurrentGCTimer* _gc_timer; 477 SoftRefPolicy _soft_ref_policy; 478 479 // For exporting to SA 480 int _log_min_obj_alignment_in_bytes; 481 public: 482 ShenandoahMonitoringSupport* monitoring_support() { return _monitoring_support; } 483 GCMemoryManager* cycle_memory_manager() { return &_cycle_memory_manager; } 484 GCMemoryManager* stw_memory_manager() { return &_stw_memory_manager; } 485 SoftRefPolicy* soft_ref_policy() { return &_soft_ref_policy; } 486 487 GrowableArray<GCMemoryManager*> memory_managers(); 488 GrowableArray<MemoryPool*> memory_pools(); 489 MemoryUsage memory_usage(); 490 GCTracer* tracer(); 491 GCTimer* gc_timer() const; 492 493 // ---------- Reference processing 494 // 495 private: 496 AlwaysTrueClosure _subject_to_discovery; 497 ReferenceProcessor* _ref_processor; 498 ShenandoahSharedFlag _process_references; 499 500 void ref_processing_init(); 501 502 public: 503 ReferenceProcessor* ref_processor() { return _ref_processor; } 504 void set_process_references(bool pr); 505 bool process_references() const; 506 507 // ---------- Class Unloading 508 // 509 private: 510 ShenandoahSharedFlag _unload_classes; 511 512 public: 513 void set_unload_classes(bool uc); 514 bool unload_classes() const; 515 516 // Perform STW class unloading and weak root cleaning 517 void parallel_cleaning(bool full_gc); 518 519 private: 520 void stw_unload_classes(bool full_gc); 521 void stw_process_weak_roots(bool full_gc); 522 523 // ---------- Generic interface hooks 524 // Minor things that super-interface expects us to implement to play nice with 525 // the rest of runtime. Some of the things here are not required to be implemented, 526 // and can be stubbed out. 527 // 528 public: 529 AdaptiveSizePolicy* size_policy() shenandoah_not_implemented_return(NULL); 530 bool is_maximal_no_gc() const shenandoah_not_implemented_return(false); 531 532 bool is_in(const void* p) const; 533 534 void collect(GCCause::Cause cause); 535 void do_full_collection(bool clear_all_soft_refs); 536 537 // Used for parsing heap during error printing 538 HeapWord* block_start(const void* addr) const; 539 bool block_is_obj(const HeapWord* addr) const; 540 541 // Used for native heap walkers: heap dumpers, mostly 542 void object_iterate(ObjectClosure* cl); 543 void safe_object_iterate(ObjectClosure* cl); 544 545 // Used by RMI 546 jlong millis_since_last_gc(); 547 548 // ---------- Safepoint interface hooks 549 // 550 public: 551 void safepoint_synchronize_begin(); 552 void safepoint_synchronize_end(); 553 554 // ---------- Code roots handling hooks 555 // 556 public: 557 void register_nmethod(nmethod* nm); 558 void unregister_nmethod(nmethod* nm); 559 void flush_nmethod(nmethod* nm) {} 560 void verify_nmethod(nmethod* nm) {} 561 562 // ---------- Pinning hooks 563 // 564 public: 565 // Shenandoah supports per-object (per-region) pinning 566 bool supports_object_pinning() const { return true; } 567 568 oop pin_object(JavaThread* thread, oop obj); 569 void unpin_object(JavaThread* thread, oop obj); 570 571 // ---------- Allocation support 572 // 573 private: 574 HeapWord* allocate_memory_under_lock(ShenandoahAllocRequest& request, bool& in_new_region); 575 inline HeapWord* allocate_from_gclab(Thread* thread, size_t size); 576 HeapWord* allocate_from_gclab_slow(Thread* thread, size_t size); 577 HeapWord* allocate_new_gclab(size_t min_size, size_t word_size, size_t* actual_size); 578 void retire_and_reset_gclabs(); 579 580 public: 581 HeapWord* allocate_memory(ShenandoahAllocRequest& request); 582 HeapWord* mem_allocate(size_t size, bool* what); 583 MetaWord* satisfy_failed_metadata_allocation(ClassLoaderData* loader_data, 584 size_t size, 585 metaspace::MetadataType mdtype); 586 587 void notify_mutator_alloc_words(size_t words, bool waste); 588 589 // Shenandoah supports TLAB allocation 590 bool supports_tlab_allocation() const { return true; } 591 592 HeapWord* allocate_new_tlab(size_t min_size, size_t requested_size, size_t* actual_size); 593 size_t tlab_capacity(Thread *thr) const; 594 size_t unsafe_max_tlab_alloc(Thread *thread) const; 595 size_t max_tlab_size() const; 596 size_t tlab_used(Thread* ignored) const; 597 598 void resize_tlabs(); 599 600 void ensure_parsability(bool retire_tlabs); 601 void make_parsable(bool retire_tlabs); 602 603 // ---------- Marking support 604 // 605 private: 606 ShenandoahMarkingContext* _marking_context; 607 MemRegion _bitmap_region; 608 MemRegion _aux_bitmap_region; 609 MarkBitMap _verification_bit_map; 610 MarkBitMap _aux_bit_map; 611 612 size_t _bitmap_size; 613 size_t _bitmap_regions_per_slice; 614 size_t _bitmap_bytes_per_slice; 615 616 bool _bitmap_region_special; 617 bool _aux_bitmap_region_special; 618 619 // Used for buffering per-region liveness data. 620 // Needed since ShenandoahHeapRegion uses atomics to update liveness. 621 // 622 // The array has max-workers elements, each of which is an array of 623 // jushort * max_regions. The choice of jushort is not accidental: 624 // there is a tradeoff between static/dynamic footprint that translates 625 // into cache pressure (which is already high during marking), and 626 // too many atomic updates. size_t/jint is too large, jbyte is too small. 627 jushort** _liveness_cache; 628 629 public: 630 inline ShenandoahMarkingContext* complete_marking_context() const; 631 inline ShenandoahMarkingContext* marking_context() const; 632 inline void mark_complete_marking_context(); 633 inline void mark_incomplete_marking_context(); 634 635 template<class T> 636 inline void marked_object_iterate(ShenandoahHeapRegion* region, T* cl); 637 638 template<class T> 639 inline void marked_object_iterate(ShenandoahHeapRegion* region, T* cl, HeapWord* limit); 640 641 template<class T> 642 inline void marked_object_oop_iterate(ShenandoahHeapRegion* region, T* cl, HeapWord* limit); 643 644 void reset_mark_bitmap(); 645 646 // SATB barriers hooks 647 template<bool RESOLVE> 648 inline bool requires_marking(const void* entry) const; 649 void force_satb_flush_all_threads(); 650 651 // Support for bitmap uncommits 652 bool commit_bitmap_slice(ShenandoahHeapRegion *r); 653 bool uncommit_bitmap_slice(ShenandoahHeapRegion *r); 654 bool is_bitmap_slice_committed(ShenandoahHeapRegion* r, bool skip_self = false); 655 656 // Liveness caching support 657 jushort* get_liveness_cache(uint worker_id); 658 void flush_liveness_cache(uint worker_id); 659 660 // ---------- Evacuation support 661 // 662 private: 663 ShenandoahCollectionSet* _collection_set; 664 ShenandoahEvacOOMHandler _oom_evac_handler; 665 666 void evacuate_and_update_roots(); 667 668 public: 669 static address in_cset_fast_test_addr(); 670 671 ShenandoahCollectionSet* collection_set() const { return _collection_set; } 672 673 template <class T> 674 inline bool in_collection_set(T obj) const; 675 676 // Avoid accidentally calling the method above with ShenandoahHeapRegion*, which would be *wrong*. 677 inline bool in_collection_set(ShenandoahHeapRegion* r) shenandoah_not_implemented_return(false); 678 679 // Evacuates object src. Returns the evacuated object, either evacuated 680 // by this thread, or by some other thread. 681 inline oop evacuate_object(oop src, Thread* thread); 682 683 // Call before/after evacuation. 684 void enter_evacuation(); 685 void leave_evacuation(); 686 687 // ---------- Helper functions 688 // 689 public: 690 template <class T> 691 inline oop evac_update_with_forwarded(T* p); 692 693 template <class T> 694 inline oop maybe_update_with_forwarded(T* p); 695 696 template <class T> 697 inline oop maybe_update_with_forwarded_not_null(T* p, oop obj); 698 699 template <class T> 700 inline oop update_with_forwarded_not_null(T* p, oop obj); 701 702 static inline oop cas_oop(oop n, narrowOop* addr, oop c); 703 static inline oop cas_oop(oop n, oop* addr, oop c); 704 705 void trash_humongous_region_at(ShenandoahHeapRegion *r); 706 707 void deduplicate_string(oop str); 708 709 void stop_concurrent_marking(); 710 711 private: 712 void trash_cset_regions(); 713 void update_heap_references(bool concurrent); 714 715 // ---------- Testing helpers functions 716 // 717 private: 718 ShenandoahSharedFlag _inject_alloc_failure; 719 720 void try_inject_alloc_failure(); 721 bool should_inject_alloc_failure(); 722 }; 723 724 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHHEAP_HPP