1 /* 2 * Copyright (c) 2023, Oracle and/or its affiliates. All rights reserved. 3 * Copyright (c) 2013, 2021, Red Hat, Inc. All rights reserved. 4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 5 * 6 * This code is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License version 2 only, as 8 * published by the Free Software Foundation. 9 * 10 * This code is distributed in the hope that it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 13 * version 2 for more details (a copy is included in the LICENSE file that 14 * accompanied this code). 15 * 16 * You should have received a copy of the GNU General Public License version 17 * 2 along with this work; if not, write to the Free Software Foundation, 18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 19 * 20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 21 * or visit www.oracle.com if you need additional information or have any 22 * questions. 23 * 24 */ 25 26 #ifndef SHARE_GC_SHENANDOAH_SHENANDOAHHEAP_HPP 27 #define SHARE_GC_SHENANDOAH_SHENANDOAHHEAP_HPP 28 29 #include "gc/shared/markBitMap.hpp" 30 #include "gc/shared/softRefPolicy.hpp" 31 #include "gc/shared/collectedHeap.hpp" 32 #include "gc/shenandoah/shenandoahAsserts.hpp" 33 #include "gc/shenandoah/shenandoahAllocRequest.hpp" 34 #include "gc/shenandoah/shenandoahLock.hpp" 35 #include "gc/shenandoah/shenandoahEvacOOMHandler.hpp" 36 #include "gc/shenandoah/shenandoahPadding.hpp" 37 #include "gc/shenandoah/shenandoahSharedVariables.hpp" 38 #include "gc/shenandoah/shenandoahUnload.hpp" 39 #include "memory/metaspace.hpp" 40 #include "services/memoryManager.hpp" 41 #include "utilities/globalDefinitions.hpp" 42 #include "utilities/stack.hpp" 43 44 class ConcurrentGCTimer; 45 class ObjectIterateScanRootClosure; 46 class ShenandoahCollectorPolicy; 47 class ShenandoahControlThread; 48 class ShenandoahGCSession; 49 class ShenandoahGCStateResetter; 50 class ShenandoahHeuristics; 51 class ShenandoahMarkingContext; 52 class ShenandoahMode; 53 class ShenandoahPhaseTimings; 54 class ShenandoahHeap; 55 class ShenandoahHeapRegion; 56 class ShenandoahHeapRegionClosure; 57 class ShenandoahCollectionSet; 58 class ShenandoahFreeSet; 59 class ShenandoahConcurrentMark; 60 class ShenandoahFullGC; 61 class ShenandoahMonitoringSupport; 62 class ShenandoahPacer; 63 class ShenandoahReferenceProcessor; 64 class ShenandoahVerifier; 65 class ShenandoahWorkerThreads; 66 class VMStructs; 67 68 // Used for buffering per-region liveness data. 69 // Needed since ShenandoahHeapRegion uses atomics to update liveness. 70 // The ShenandoahHeap array has max-workers elements, each of which is an array of 71 // uint16_t * max_regions. The choice of uint16_t is not accidental: 72 // there is a tradeoff between static/dynamic footprint that translates 73 // into cache pressure (which is already high during marking), and 74 // too many atomic updates. uint32_t is too large, uint8_t is too small. 75 typedef uint16_t ShenandoahLiveData; 76 #define SHENANDOAH_LIVEDATA_MAX ((ShenandoahLiveData)-1) 77 78 class ShenandoahRegionIterator : public StackObj { 79 private: 80 ShenandoahHeap* _heap; 81 82 shenandoah_padding(0); 83 volatile size_t _index; 84 shenandoah_padding(1); 85 86 // No implicit copying: iterators should be passed by reference to capture the state 87 NONCOPYABLE(ShenandoahRegionIterator); 88 89 public: 90 ShenandoahRegionIterator(); 91 ShenandoahRegionIterator(ShenandoahHeap* heap); 92 93 // Reset iterator to default state 94 void reset(); 95 96 // Returns next region, or null if there are no more regions. 97 // This is multi-thread-safe. 98 inline ShenandoahHeapRegion* next(); 99 100 // This is *not* MT safe. However, in the absence of multithreaded access, it 101 // can be used to determine if there is more work to do. 102 bool has_next() const; 103 }; 104 105 class ShenandoahHeapRegionClosure : public StackObj { 106 public: 107 virtual void heap_region_do(ShenandoahHeapRegion* r) = 0; 108 virtual bool is_thread_safe() { return false; } 109 }; 110 111 typedef ShenandoahLock ShenandoahHeapLock; 112 typedef ShenandoahLocker ShenandoahHeapLocker; 113 typedef Stack<oop, mtGC> ShenandoahScanObjectStack; 114 115 // Shenandoah GC is low-pause concurrent GC that uses Brooks forwarding pointers 116 // to encode forwarding data. See BrooksPointer for details on forwarding data encoding. 117 // See ShenandoahControlThread for GC cycle structure. 118 // 119 class ShenandoahHeap : public CollectedHeap { 120 friend class ShenandoahAsserts; 121 friend class VMStructs; 122 friend class ShenandoahGCSession; 123 friend class ShenandoahGCStateResetter; 124 friend class ShenandoahParallelObjectIterator; 125 friend class ShenandoahSafepoint; 126 // Supported GC 127 friend class ShenandoahConcurrentGC; 128 friend class ShenandoahDegenGC; 129 friend class ShenandoahFullGC; 130 friend class ShenandoahUnload; 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 override { return "Shenandoah"; } 148 ShenandoahHeap::Name kind() const override { return CollectedHeap::Shenandoah; } 149 150 ShenandoahHeap(ShenandoahCollectorPolicy* policy); 151 jint initialize() override; 152 void post_initialize() override; 153 void initialize_mode(); 154 void initialize_heuristics(); 155 156 void initialize_serviceability() override; 157 158 void print_on(outputStream* st) const override; 159 void print_extended_on(outputStream *st) const override; 160 void print_tracing_info() const override; 161 void print_heap_regions_on(outputStream* st) const; 162 163 void stop() override; 164 165 void prepare_for_verify() override; 166 void verify(VerifyOption vo) override; 167 168 // WhiteBox testing support. 169 bool supports_concurrent_gc_breakpoints() const override { 170 return true; 171 } 172 173 // ---------- Heap counters and metrics 174 // 175 private: 176 size_t _initial_size; 177 size_t _minimum_size; 178 volatile size_t _soft_max_size; 179 shenandoah_padding(0); 180 volatile size_t _used; 181 volatile size_t _committed; 182 volatile size_t _bytes_allocated_since_gc_start; 183 shenandoah_padding(1); 184 185 public: 186 void increase_used(size_t bytes); 187 void decrease_used(size_t bytes); 188 void set_used(size_t bytes); 189 190 void increase_committed(size_t bytes); 191 void decrease_committed(size_t bytes); 192 void increase_allocated(size_t bytes); 193 194 size_t bytes_allocated_since_gc_start(); 195 void reset_bytes_allocated_since_gc_start(); 196 197 size_t min_capacity() const; 198 size_t max_capacity() const override; 199 size_t soft_max_capacity() const; 200 size_t initial_capacity() const; 201 size_t capacity() const override; 202 size_t used() const override; 203 size_t committed() const; 204 205 void set_soft_max_capacity(size_t v); 206 207 // ---------- Workers handling 208 // 209 private: 210 uint _max_workers; 211 ShenandoahWorkerThreads* _workers; 212 ShenandoahWorkerThreads* _safepoint_workers; 213 214 public: 215 uint max_workers(); 216 void assert_gc_workers(uint nworker) NOT_DEBUG_RETURN; 217 218 WorkerThreads* workers() const; 219 WorkerThreads* safepoint_workers() override; 220 221 void gc_threads_do(ThreadClosure* tcl) const override; 222 223 // ---------- Heap regions handling machinery 224 // 225 private: 226 MemRegion _heap_region; 227 bool _heap_region_special; 228 size_t _num_regions; 229 ShenandoahHeapRegion** _regions; 230 ShenandoahRegionIterator _update_refs_iterator; 231 232 public: 233 234 inline HeapWord* base() const { return _heap_region.start(); } 235 236 inline size_t num_regions() const { return _num_regions; } 237 inline bool is_heap_region_special() { return _heap_region_special; } 238 239 inline ShenandoahHeapRegion* const heap_region_containing(const void* addr) const; 240 inline size_t heap_region_index_containing(const void* addr) const; 241 242 inline ShenandoahHeapRegion* const get_region(size_t region_idx) const; 243 244 void heap_region_iterate(ShenandoahHeapRegionClosure* blk) const; 245 void parallel_heap_region_iterate(ShenandoahHeapRegionClosure* blk) const; 246 247 // ---------- GC state machinery 248 // 249 // GC state describes the important parts of collector state, that may be 250 // used to make barrier selection decisions in the native and generated code. 251 // Multiple bits can be set at once. 252 // 253 // Important invariant: when GC state is zero, the heap is stable, and no barriers 254 // are required. 255 // 256 public: 257 enum GCStateBitPos { 258 // Heap has forwarded objects: needs LRB barriers. 259 HAS_FORWARDED_BITPOS = 0, 260 261 // Heap is under marking: needs SATB barriers. 262 MARKING_BITPOS = 1, 263 264 // Heap is under evacuation: needs LRB barriers. (Set together with HAS_FORWARDED) 265 EVACUATION_BITPOS = 2, 266 267 // Heap is under updating: needs no additional barriers. 268 UPDATEREFS_BITPOS = 3, 269 270 // Heap is under weak-reference/roots processing: needs weak-LRB barriers. 271 WEAK_ROOTS_BITPOS = 4, 272 }; 273 274 enum GCState { 275 STABLE = 0, 276 HAS_FORWARDED = 1 << HAS_FORWARDED_BITPOS, 277 MARKING = 1 << MARKING_BITPOS, 278 EVACUATION = 1 << EVACUATION_BITPOS, 279 UPDATEREFS = 1 << UPDATEREFS_BITPOS, 280 WEAK_ROOTS = 1 << WEAK_ROOTS_BITPOS, 281 }; 282 283 private: 284 ShenandoahSharedBitmap _gc_state; 285 ShenandoahSharedFlag _degenerated_gc_in_progress; 286 ShenandoahSharedFlag _full_gc_in_progress; 287 ShenandoahSharedFlag _full_gc_move_in_progress; 288 ShenandoahSharedFlag _progress_last_gc; 289 ShenandoahSharedFlag _concurrent_strong_root_in_progress; 290 291 void set_gc_state_all_threads(char state); 292 void set_gc_state_mask(uint mask, bool value); 293 294 public: 295 char gc_state() const; 296 static address gc_state_addr(); 297 298 void set_concurrent_mark_in_progress(bool in_progress); 299 void set_evacuation_in_progress(bool in_progress); 300 void set_update_refs_in_progress(bool in_progress); 301 void set_degenerated_gc_in_progress(bool in_progress); 302 void set_full_gc_in_progress(bool in_progress); 303 void set_full_gc_move_in_progress(bool in_progress); 304 void set_has_forwarded_objects(bool cond); 305 void set_concurrent_strong_root_in_progress(bool cond); 306 void set_concurrent_weak_root_in_progress(bool cond); 307 308 inline bool is_stable() const; 309 inline bool is_idle() const; 310 inline bool is_concurrent_mark_in_progress() const; 311 inline bool is_update_refs_in_progress() const; 312 inline bool is_evacuation_in_progress() const; 313 inline bool is_degenerated_gc_in_progress() const; 314 inline bool is_full_gc_in_progress() const; 315 inline bool is_full_gc_move_in_progress() const; 316 inline bool has_forwarded_objects() const; 317 inline bool is_gc_in_progress_mask(uint mask) const; 318 inline bool is_stw_gc_in_progress() const; 319 inline bool is_concurrent_strong_root_in_progress() const; 320 inline bool is_concurrent_weak_root_in_progress() const; 321 322 private: 323 enum CancelState { 324 // Normal state. GC has not been cancelled and is open for cancellation. 325 // Worker threads can suspend for safepoint. 326 CANCELLABLE, 327 328 // GC has been cancelled. Worker threads can not suspend for 329 // safepoint but must finish their work as soon as possible. 330 CANCELLED, 331 332 // GC has not been cancelled and must not be cancelled. At least 333 // one worker thread checks for pending safepoint and may suspend 334 // if a safepoint is pending. 335 NOT_CANCELLED 336 }; 337 338 ShenandoahSharedEnumFlag<CancelState> _cancelled_gc; 339 bool try_cancel_gc(); 340 341 public: 342 static address cancelled_gc_addr(); 343 344 inline bool cancelled_gc() const; 345 inline bool check_cancelled_gc_and_yield(bool sts_active = true); 346 347 inline void clear_cancelled_gc(); 348 349 void cancel_gc(GCCause::Cause cause); 350 351 public: 352 // Elastic heap support 353 void entry_uncommit(double shrink_before, size_t shrink_until); 354 void op_uncommit(double shrink_before, size_t shrink_until); 355 356 private: 357 // GC support 358 // Reset bitmap, prepare regions for new GC cycle 359 void prepare_gc(); 360 void prepare_regions_and_collection_set(bool concurrent); 361 // Evacuation 362 void prepare_evacuation(bool concurrent); 363 void evacuate_collection_set(bool concurrent); 364 // Concurrent root processing 365 void prepare_concurrent_roots(); 366 void finish_concurrent_roots(); 367 // Concurrent class unloading support 368 void do_class_unloading(); 369 // Reference updating 370 void prepare_update_heap_references(bool concurrent); 371 void update_heap_references(bool concurrent); 372 // Final update region states 373 void update_heap_region_states(bool concurrent); 374 void rebuild_free_set(bool concurrent); 375 376 void rendezvous_threads(); 377 void recycle_trash(); 378 public: 379 void notify_gc_progress() { _progress_last_gc.set(); } 380 void notify_gc_no_progress() { _progress_last_gc.unset(); } 381 382 // 383 // Mark support 384 private: 385 ShenandoahControlThread* _control_thread; 386 ShenandoahCollectorPolicy* _shenandoah_policy; 387 ShenandoahMode* _gc_mode; 388 ShenandoahHeuristics* _heuristics; 389 ShenandoahFreeSet* _free_set; 390 ShenandoahPacer* _pacer; 391 ShenandoahVerifier* _verifier; 392 393 ShenandoahPhaseTimings* _phase_timings; 394 395 ShenandoahControlThread* control_thread() { return _control_thread; } 396 397 public: 398 ShenandoahCollectorPolicy* shenandoah_policy() const { return _shenandoah_policy; } 399 ShenandoahMode* mode() const { return _gc_mode; } 400 ShenandoahHeuristics* heuristics() const { return _heuristics; } 401 ShenandoahFreeSet* free_set() const { return _free_set; } 402 ShenandoahPacer* pacer() const { return _pacer; } 403 404 ShenandoahPhaseTimings* phase_timings() const { return _phase_timings; } 405 406 ShenandoahVerifier* verifier(); 407 408 // ---------- VM subsystem bindings 409 // 410 private: 411 ShenandoahMonitoringSupport* _monitoring_support; 412 MemoryPool* _memory_pool; 413 GCMemoryManager _stw_memory_manager; 414 GCMemoryManager _cycle_memory_manager; 415 ConcurrentGCTimer* _gc_timer; 416 SoftRefPolicy _soft_ref_policy; 417 418 // For exporting to SA 419 int _log_min_obj_alignment_in_bytes; 420 public: 421 ShenandoahMonitoringSupport* monitoring_support() { return _monitoring_support; } 422 GCMemoryManager* cycle_memory_manager() { return &_cycle_memory_manager; } 423 GCMemoryManager* stw_memory_manager() { return &_stw_memory_manager; } 424 SoftRefPolicy* soft_ref_policy() override { return &_soft_ref_policy; } 425 426 GrowableArray<GCMemoryManager*> memory_managers() override; 427 GrowableArray<MemoryPool*> memory_pools() override; 428 MemoryUsage memory_usage() override; 429 GCTracer* tracer(); 430 ConcurrentGCTimer* gc_timer() const; 431 432 // ---------- Reference processing 433 // 434 private: 435 ShenandoahReferenceProcessor* const _ref_processor; 436 437 public: 438 ShenandoahReferenceProcessor* ref_processor() { return _ref_processor; } 439 440 // ---------- Class Unloading 441 // 442 private: 443 ShenandoahSharedFlag _unload_classes; 444 ShenandoahUnload _unloader; 445 446 public: 447 void set_unload_classes(bool uc); 448 bool unload_classes() const; 449 450 // Perform STW class unloading and weak root cleaning 451 void parallel_cleaning(bool full_gc); 452 453 private: 454 void stw_unload_classes(bool full_gc); 455 void stw_process_weak_roots(bool full_gc); 456 void stw_weak_refs(bool full_gc); 457 458 // Heap iteration support 459 void scan_roots_for_iteration(ShenandoahScanObjectStack* oop_stack, ObjectIterateScanRootClosure* oops); 460 bool prepare_aux_bitmap_for_iteration(); 461 void reclaim_aux_bitmap_for_iteration(); 462 463 // ---------- Generic interface hooks 464 // Minor things that super-interface expects us to implement to play nice with 465 // the rest of runtime. Some of the things here are not required to be implemented, 466 // and can be stubbed out. 467 // 468 public: 469 bool is_maximal_no_gc() const override shenandoah_not_implemented_return(false); 470 471 bool is_in(const void* p) const override; 472 473 bool requires_barriers(stackChunkOop obj) const override; 474 475 MemRegion reserved_region() const { return _reserved; } 476 bool is_in_reserved(const void* addr) const { return _reserved.contains(addr); } 477 478 void collect(GCCause::Cause cause) override; 479 void do_full_collection(bool clear_all_soft_refs) override; 480 481 // Used for parsing heap during error printing 482 HeapWord* block_start(const void* addr) const; 483 bool block_is_obj(const HeapWord* addr) const; 484 bool print_location(outputStream* st, void* addr) const override; 485 486 // Used for native heap walkers: heap dumpers, mostly 487 void object_iterate(ObjectClosure* cl) override; 488 // Parallel heap iteration support 489 ParallelObjectIteratorImpl* parallel_object_iterator(uint workers) override; 490 491 // Keep alive an object that was loaded with AS_NO_KEEPALIVE. 492 void keep_alive(oop obj) override; 493 494 // ---------- Safepoint interface hooks 495 // 496 public: 497 void safepoint_synchronize_begin() override; 498 void safepoint_synchronize_end() override; 499 500 // ---------- Code roots handling hooks 501 // 502 public: 503 void register_nmethod(nmethod* nm) override; 504 void unregister_nmethod(nmethod* nm) override; 505 void verify_nmethod(nmethod* nm) override {} 506 507 // ---------- Pinning hooks 508 // 509 public: 510 // Shenandoah supports per-object (per-region) pinning 511 void pin_object(JavaThread* thread, oop obj) override; 512 void unpin_object(JavaThread* thread, oop obj) override; 513 514 void sync_pinned_region_status(); 515 void assert_pinned_region_status() NOT_DEBUG_RETURN; 516 517 // ---------- Concurrent Stack Processing support 518 // 519 public: 520 bool uses_stack_watermark_barrier() const override { return true; } 521 522 // ---------- Allocation support 523 // 524 private: 525 HeapWord* allocate_memory_under_lock(ShenandoahAllocRequest& request, bool& in_new_region); 526 inline HeapWord* allocate_from_gclab(Thread* thread, size_t size); 527 HeapWord* allocate_from_gclab_slow(Thread* thread, size_t size); 528 HeapWord* allocate_new_gclab(size_t min_size, size_t word_size, size_t* actual_size); 529 530 public: 531 HeapWord* allocate_memory(ShenandoahAllocRequest& request); 532 HeapWord* mem_allocate(size_t size, bool* what) override; 533 MetaWord* satisfy_failed_metadata_allocation(ClassLoaderData* loader_data, 534 size_t size, 535 Metaspace::MetadataType mdtype) override; 536 537 void notify_mutator_alloc_words(size_t words, bool waste); 538 539 HeapWord* allocate_new_tlab(size_t min_size, size_t requested_size, size_t* actual_size) override; 540 size_t tlab_capacity(Thread *thr) const override; 541 size_t unsafe_max_tlab_alloc(Thread *thread) const override; 542 size_t max_tlab_size() const override; 543 size_t tlab_used(Thread* ignored) const override; 544 545 void ensure_parsability(bool retire_labs) override; 546 547 void labs_make_parsable(); 548 void tlabs_retire(bool resize); 549 void gclabs_retire(bool resize); 550 551 // ---------- Marking support 552 // 553 private: 554 ShenandoahMarkingContext* _marking_context; 555 MemRegion _bitmap_region; 556 MemRegion _aux_bitmap_region; 557 MarkBitMap _verification_bit_map; 558 MarkBitMap _aux_bit_map; 559 560 size_t _bitmap_size; 561 size_t _bitmap_regions_per_slice; 562 size_t _bitmap_bytes_per_slice; 563 564 size_t _pretouch_heap_page_size; 565 size_t _pretouch_bitmap_page_size; 566 567 bool _bitmap_region_special; 568 bool _aux_bitmap_region_special; 569 570 ShenandoahLiveData** _liveness_cache; 571 572 public: 573 inline ShenandoahMarkingContext* complete_marking_context() const; 574 inline ShenandoahMarkingContext* marking_context() const; 575 inline void mark_complete_marking_context(); 576 inline void mark_incomplete_marking_context(); 577 578 template<class T> 579 inline void marked_object_iterate(ShenandoahHeapRegion* region, T* cl); 580 581 template<class T> 582 inline void marked_object_iterate(ShenandoahHeapRegion* region, T* cl, HeapWord* limit); 583 584 template<class T> 585 inline void marked_object_oop_iterate(ShenandoahHeapRegion* region, T* cl, HeapWord* limit); 586 587 void reset_mark_bitmap(); 588 589 // SATB barriers hooks 590 inline bool requires_marking(const void* entry) const; 591 592 // Support for bitmap uncommits 593 bool commit_bitmap_slice(ShenandoahHeapRegion *r); 594 bool uncommit_bitmap_slice(ShenandoahHeapRegion *r); 595 bool is_bitmap_slice_committed(ShenandoahHeapRegion* r, bool skip_self = false); 596 597 // Liveness caching support 598 ShenandoahLiveData* get_liveness_cache(uint worker_id); 599 void flush_liveness_cache(uint worker_id); 600 601 size_t pretouch_heap_page_size() { return _pretouch_heap_page_size; } 602 603 // ---------- Evacuation support 604 // 605 private: 606 ShenandoahCollectionSet* _collection_set; 607 ShenandoahEvacOOMHandler _oom_evac_handler; 608 609 public: 610 static address in_cset_fast_test_addr(); 611 612 ShenandoahCollectionSet* collection_set() const { return _collection_set; } 613 614 // Checks if object is in the collection set. 615 inline bool in_collection_set(oop obj) const; 616 617 // Checks if location is in the collection set. Can be interior pointer, not the oop itself. 618 inline bool in_collection_set_loc(void* loc) const; 619 620 // Evacuates object src. Returns the evacuated object, either evacuated 621 // by this thread, or by some other thread. 622 inline oop evacuate_object(oop src, Thread* thread); 623 624 // Call before/after evacuation. 625 inline void enter_evacuation(Thread* t); 626 inline void leave_evacuation(Thread* t); 627 628 // ---------- Helper functions 629 // 630 public: 631 template <class T> 632 inline void conc_update_with_forwarded(T* p); 633 634 template <class T> 635 inline void update_with_forwarded(T* p); 636 637 static inline void atomic_update_oop(oop update, oop* addr, oop compare); 638 static inline void atomic_update_oop(oop update, narrowOop* addr, oop compare); 639 static inline void atomic_update_oop(oop update, narrowOop* addr, narrowOop compare); 640 641 static inline bool atomic_update_oop_check(oop update, oop* addr, oop compare); 642 static inline bool atomic_update_oop_check(oop update, narrowOop* addr, oop compare); 643 static inline bool atomic_update_oop_check(oop update, narrowOop* addr, narrowOop compare); 644 645 static inline void atomic_clear_oop( oop* addr, oop compare); 646 static inline void atomic_clear_oop(narrowOop* addr, oop compare); 647 static inline void atomic_clear_oop(narrowOop* addr, narrowOop compare); 648 649 void trash_humongous_region_at(ShenandoahHeapRegion *r); 650 651 private: 652 void trash_cset_regions(); 653 654 // ---------- Testing helpers functions 655 // 656 private: 657 ShenandoahSharedFlag _inject_alloc_failure; 658 659 void try_inject_alloc_failure(); 660 bool should_inject_alloc_failure(); 661 }; 662 663 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHHEAP_HPP