1 /* 2 * Copyright (c) 2023, 2024, 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/heuristics/shenandoahSpaceInfo.hpp" 33 #include "gc/shenandoah/shenandoahAsserts.hpp" 34 #include "gc/shenandoah/shenandoahAllocRequest.hpp" 35 #include "gc/shenandoah/shenandoahLock.hpp" 36 #include "gc/shenandoah/shenandoahEvacOOMHandler.hpp" 37 #include "gc/shenandoah/shenandoahPadding.hpp" 38 #include "gc/shenandoah/shenandoahSharedVariables.hpp" 39 #include "gc/shenandoah/shenandoahUnload.hpp" 40 #include "memory/metaspace.hpp" 41 #include "services/memoryManager.hpp" 42 #include "utilities/globalDefinitions.hpp" 43 #include "utilities/stack.hpp" 44 45 class ConcurrentGCTimer; 46 class ObjectIterateScanRootClosure; 47 class ShenandoahCollectorPolicy; 48 class ShenandoahControlThread; 49 class ShenandoahGCSession; 50 class ShenandoahGCStateResetter; 51 class ShenandoahHeuristics; 52 class ShenandoahMarkingContext; 53 class ShenandoahMode; 54 class ShenandoahPhaseTimings; 55 class ShenandoahHeap; 56 class ShenandoahHeapRegion; 57 class ShenandoahHeapRegionClosure; 58 class ShenandoahCollectionSet; 59 class ShenandoahFreeSet; 60 class ShenandoahConcurrentMark; 61 class ShenandoahFullGC; 62 class ShenandoahMonitoringSupport; 63 class ShenandoahPacer; 64 class ShenandoahReferenceProcessor; 65 class ShenandoahVerifier; 66 class ShenandoahWorkerThreads; 67 class VMStructs; 68 69 // Used for buffering per-region liveness data. 70 // Needed since ShenandoahHeapRegion uses atomics to update liveness. 71 // The ShenandoahHeap array has max-workers elements, each of which is an array of 72 // uint16_t * max_regions. The choice of uint16_t is not accidental: 73 // there is a tradeoff between static/dynamic footprint that translates 74 // into cache pressure (which is already high during marking), and 75 // too many atomic updates. uint32_t is too large, uint8_t is too small. 76 typedef uint16_t ShenandoahLiveData; 77 #define SHENANDOAH_LIVEDATA_MAX ((ShenandoahLiveData)-1) 78 79 class ShenandoahRegionIterator : public StackObj { 80 private: 81 ShenandoahHeap* _heap; 82 83 shenandoah_padding(0); 84 volatile size_t _index; 85 shenandoah_padding(1); 86 87 // No implicit copying: iterators should be passed by reference to capture the state 88 NONCOPYABLE(ShenandoahRegionIterator); 89 90 public: 91 ShenandoahRegionIterator(); 92 ShenandoahRegionIterator(ShenandoahHeap* heap); 93 94 // Reset iterator to default state 95 void reset(); 96 97 // Returns next region, or null if there are no more regions. 98 // This is multi-thread-safe. 99 inline ShenandoahHeapRegion* next(); 100 101 // This is *not* MT safe. However, in the absence of multithreaded access, it 102 // can be used to determine if there is more work to do. 103 bool has_next() const; 104 }; 105 106 class ShenandoahHeapRegionClosure : public StackObj { 107 public: 108 virtual void heap_region_do(ShenandoahHeapRegion* r) = 0; 109 virtual bool is_thread_safe() { return false; } 110 }; 111 112 typedef ShenandoahLock ShenandoahHeapLock; 113 typedef ShenandoahLocker ShenandoahHeapLocker; 114 typedef Stack<oop, mtGC> ShenandoahScanObjectStack; 115 116 // Shenandoah GC is low-pause concurrent GC that uses Brooks forwarding pointers 117 // to encode forwarding data. See BrooksPointer for details on forwarding data encoding. 118 // See ShenandoahControlThread for GC cycle structure. 119 // 120 class ShenandoahHeap : public CollectedHeap, public ShenandoahSpaceInfo { 121 friend class ShenandoahAsserts; 122 friend class VMStructs; 123 friend class ShenandoahGCSession; 124 friend class ShenandoahGCStateResetter; 125 friend class ShenandoahParallelObjectIterator; 126 friend class ShenandoahSafepoint; 127 128 // Supported GC 129 friend class ShenandoahConcurrentGC; 130 friend class ShenandoahDegenGC; 131 friend class ShenandoahFullGC; 132 friend class ShenandoahUnload; 133 134 // ---------- Locks that guard important data structures in Heap 135 // 136 private: 137 ShenandoahHeapLock _lock; 138 139 public: 140 ShenandoahHeapLock* lock() { 141 return &_lock; 142 } 143 144 // ---------- Initialization, termination, identification, printing routines 145 // 146 public: 147 static ShenandoahHeap* heap(); 148 149 const char* name() const override { return "Shenandoah"; } 150 ShenandoahHeap::Name kind() const override { return CollectedHeap::Shenandoah; } 151 152 ShenandoahHeap(ShenandoahCollectorPolicy* policy); 153 jint initialize() override; 154 void post_initialize() override; 155 void initialize_mode(); 156 void initialize_heuristics(); 157 158 void initialize_serviceability() override; 159 160 void print_on(outputStream* st) const override; 161 void print_extended_on(outputStream *st) const override; 162 void print_tracing_info() const override; 163 void print_heap_regions_on(outputStream* st) const; 164 165 void stop() override; 166 167 void prepare_for_verify() override; 168 void verify(VerifyOption vo) override; 169 170 // WhiteBox testing support. 171 bool supports_concurrent_gc_breakpoints() const override { 172 return true; 173 } 174 175 // ---------- Heap counters and metrics 176 // 177 private: 178 size_t _initial_size; 179 size_t _minimum_size; 180 volatile size_t _soft_max_size; 181 shenandoah_padding(0); 182 volatile size_t _used; 183 volatile size_t _committed; 184 volatile size_t _bytes_allocated_since_gc_start; 185 shenandoah_padding(1); 186 187 public: 188 void increase_used(size_t bytes); 189 void decrease_used(size_t bytes); 190 void set_used(size_t bytes); 191 192 void increase_committed(size_t bytes); 193 void decrease_committed(size_t bytes); 194 void increase_allocated(size_t bytes); 195 196 size_t bytes_allocated_since_gc_start() const override; 197 void reset_bytes_allocated_since_gc_start(); 198 199 size_t min_capacity() const; 200 size_t max_capacity() const override; 201 size_t soft_max_capacity() const override; 202 size_t initial_capacity() const; 203 size_t capacity() const override; 204 size_t used() const override; 205 size_t committed() const; 206 size_t available() const override; 207 208 void set_soft_max_capacity(size_t v); 209 210 // ---------- Periodic Tasks 211 // 212 private: 213 void notify_heap_changed(); 214 215 public: 216 void set_forced_counters_update(bool value); 217 void handle_force_counters_update(); 218 219 // ---------- Workers handling 220 // 221 private: 222 uint _max_workers; 223 ShenandoahWorkerThreads* _workers; 224 ShenandoahWorkerThreads* _safepoint_workers; 225 226 public: 227 uint max_workers(); 228 void assert_gc_workers(uint nworker) NOT_DEBUG_RETURN; 229 230 WorkerThreads* workers() const; 231 WorkerThreads* safepoint_workers() override; 232 233 void gc_threads_do(ThreadClosure* tcl) const override; 234 235 // ---------- Heap regions handling machinery 236 // 237 private: 238 MemRegion _heap_region; 239 bool _heap_region_special; 240 size_t _num_regions; 241 ShenandoahHeapRegion** _regions; 242 ShenandoahRegionIterator _update_refs_iterator; 243 244 public: 245 246 inline HeapWord* base() const { return _heap_region.start(); } 247 248 inline size_t num_regions() const { return _num_regions; } 249 inline bool is_heap_region_special() { return _heap_region_special; } 250 251 inline ShenandoahHeapRegion* heap_region_containing(const void* addr) const; 252 inline size_t heap_region_index_containing(const void* addr) const; 253 254 inline ShenandoahHeapRegion* get_region(size_t region_idx) const; 255 256 void heap_region_iterate(ShenandoahHeapRegionClosure* blk) const; 257 void parallel_heap_region_iterate(ShenandoahHeapRegionClosure* blk) const; 258 259 // ---------- GC state machinery 260 // 261 // GC state describes the important parts of collector state, that may be 262 // used to make barrier selection decisions in the native and generated code. 263 // Multiple bits can be set at once. 264 // 265 // Important invariant: when GC state is zero, the heap is stable, and no barriers 266 // are required. 267 // 268 public: 269 enum GCStateBitPos { 270 // Heap has forwarded objects: needs LRB barriers. 271 HAS_FORWARDED_BITPOS = 0, 272 273 // Heap is under marking: needs SATB barriers. 274 MARKING_BITPOS = 1, 275 276 // Heap is under evacuation: needs LRB barriers. (Set together with HAS_FORWARDED) 277 EVACUATION_BITPOS = 2, 278 279 // Heap is under updating: needs no additional barriers. 280 UPDATEREFS_BITPOS = 3, 281 282 // Heap is under weak-reference/roots processing: needs weak-LRB barriers. 283 WEAK_ROOTS_BITPOS = 4, 284 }; 285 286 enum GCState { 287 STABLE = 0, 288 HAS_FORWARDED = 1 << HAS_FORWARDED_BITPOS, 289 MARKING = 1 << MARKING_BITPOS, 290 EVACUATION = 1 << EVACUATION_BITPOS, 291 UPDATEREFS = 1 << UPDATEREFS_BITPOS, 292 WEAK_ROOTS = 1 << WEAK_ROOTS_BITPOS, 293 }; 294 295 private: 296 bool _gc_state_changed; 297 ShenandoahSharedBitmap _gc_state; 298 299 // tracks if new regions have been allocated or retired since last check 300 ShenandoahSharedFlag _heap_changed; 301 ShenandoahSharedFlag _degenerated_gc_in_progress; 302 ShenandoahSharedFlag _full_gc_in_progress; 303 ShenandoahSharedFlag _full_gc_move_in_progress; 304 ShenandoahSharedFlag _concurrent_strong_root_in_progress; 305 306 size_t _gc_no_progress_count; 307 308 // This updates the singlular, global gc state. This must happen on a safepoint. 309 void set_gc_state(uint mask, bool value); 310 311 public: 312 char gc_state() const; 313 314 // This copies the global gc state into a thread local variable for java threads. 315 // It is primarily intended to support quick access at barriers. 316 void propagate_gc_state_to_java_threads(); 317 318 // This is public to support assertions that the state hasn't been changed off of 319 // a safepoint and that any changes were propagated to java threads after the safepoint. 320 bool has_gc_state_changed() const { return _gc_state_changed; } 321 322 // Returns true if allocations have occurred in new regions or if regions have been 323 // uncommitted since the previous calls. This call will reset the flag to false. 324 bool has_changed() { 325 return _heap_changed.try_unset(); 326 } 327 328 void set_concurrent_mark_in_progress(bool in_progress); 329 void set_evacuation_in_progress(bool in_progress); 330 void set_update_refs_in_progress(bool in_progress); 331 void set_degenerated_gc_in_progress(bool in_progress); 332 void set_full_gc_in_progress(bool in_progress); 333 void set_full_gc_move_in_progress(bool in_progress); 334 void set_has_forwarded_objects(bool cond); 335 void set_concurrent_strong_root_in_progress(bool cond); 336 void set_concurrent_weak_root_in_progress(bool cond); 337 338 inline bool is_stable() const; 339 inline bool is_idle() const; 340 inline bool is_concurrent_mark_in_progress() const; 341 inline bool is_update_refs_in_progress() const; 342 inline bool is_evacuation_in_progress() const; 343 inline bool is_degenerated_gc_in_progress() const; 344 inline bool is_full_gc_in_progress() const; 345 inline bool is_full_gc_move_in_progress() const; 346 inline bool has_forwarded_objects() const; 347 348 inline bool is_stw_gc_in_progress() const; 349 inline bool is_concurrent_strong_root_in_progress() const; 350 inline bool is_concurrent_weak_root_in_progress() const; 351 352 private: 353 enum CancelState { 354 // Normal state. GC has not been cancelled and is open for cancellation. 355 // Worker threads can suspend for safepoint. 356 CANCELLABLE, 357 358 // GC has been cancelled. Worker threads can not suspend for 359 // safepoint but must finish their work as soon as possible. 360 CANCELLED 361 }; 362 363 ShenandoahSharedEnumFlag<CancelState> _cancelled_gc; 364 bool try_cancel_gc(); 365 366 public: 367 368 inline bool cancelled_gc() const; 369 inline bool check_cancelled_gc_and_yield(bool sts_active = true); 370 371 inline void clear_cancelled_gc(); 372 373 void cancel_gc(GCCause::Cause cause); 374 375 public: 376 // These will uncommit empty regions if heap::committed > shrink_until 377 // and there exists at least one region which was made empty before shrink_before. 378 void maybe_uncommit(double shrink_before, size_t shrink_until); 379 void op_uncommit(double shrink_before, size_t shrink_until); 380 381 // Returns true if the soft maximum heap has been changed using management APIs. 382 bool check_soft_max_changed(); 383 384 private: 385 // GC support 386 // Reset bitmap, prepare regions for new GC cycle 387 void prepare_gc(); 388 void prepare_regions_and_collection_set(bool concurrent); 389 // Evacuation 390 void evacuate_collection_set(bool concurrent); 391 // Concurrent root processing 392 void prepare_concurrent_roots(); 393 void finish_concurrent_roots(); 394 // Concurrent class unloading support 395 void do_class_unloading(); 396 // Reference updating 397 void prepare_update_heap_references(bool concurrent); 398 void update_heap_references(bool concurrent); 399 // Final update region states 400 void update_heap_region_states(bool concurrent); 401 void rebuild_free_set(bool concurrent); 402 403 void rendezvous_threads(const char* name); 404 void recycle_trash(); 405 public: 406 void notify_gc_progress(); 407 void notify_gc_no_progress(); 408 size_t get_gc_no_progress_count() const; 409 410 // 411 // Mark support 412 private: 413 ShenandoahControlThread* _control_thread; 414 ShenandoahCollectorPolicy* _shenandoah_policy; 415 ShenandoahMode* _gc_mode; 416 ShenandoahHeuristics* _heuristics; 417 ShenandoahFreeSet* _free_set; 418 ShenandoahPacer* _pacer; 419 ShenandoahVerifier* _verifier; 420 421 ShenandoahPhaseTimings* _phase_timings; 422 423 ShenandoahControlThread* control_thread() { return _control_thread; } 424 425 public: 426 ShenandoahCollectorPolicy* shenandoah_policy() const { return _shenandoah_policy; } 427 ShenandoahMode* mode() const { return _gc_mode; } 428 ShenandoahHeuristics* heuristics() const { return _heuristics; } 429 ShenandoahFreeSet* free_set() const { return _free_set; } 430 ShenandoahPacer* pacer() const { return _pacer; } 431 432 ShenandoahPhaseTimings* phase_timings() const { return _phase_timings; } 433 434 ShenandoahVerifier* verifier(); 435 436 // ---------- VM subsystem bindings 437 // 438 private: 439 ShenandoahMonitoringSupport* _monitoring_support; 440 MemoryPool* _memory_pool; 441 GCMemoryManager _stw_memory_manager; 442 GCMemoryManager _cycle_memory_manager; 443 ConcurrentGCTimer* _gc_timer; 444 // For exporting to SA 445 int _log_min_obj_alignment_in_bytes; 446 public: 447 ShenandoahMonitoringSupport* monitoring_support() { return _monitoring_support; } 448 GCMemoryManager* cycle_memory_manager() { return &_cycle_memory_manager; } 449 GCMemoryManager* stw_memory_manager() { return &_stw_memory_manager; } 450 451 GrowableArray<GCMemoryManager*> memory_managers() override; 452 GrowableArray<MemoryPool*> memory_pools() override; 453 MemoryUsage memory_usage() override; 454 GCTracer* tracer(); 455 ConcurrentGCTimer* gc_timer() const; 456 457 // ---------- Reference processing 458 // 459 private: 460 ShenandoahReferenceProcessor* const _ref_processor; 461 462 public: 463 ShenandoahReferenceProcessor* ref_processor() { return _ref_processor; } 464 465 // ---------- Class Unloading 466 // 467 private: 468 ShenandoahSharedFlag _unload_classes; 469 ShenandoahUnload _unloader; 470 471 public: 472 void set_unload_classes(bool uc); 473 bool unload_classes() const; 474 475 // Perform STW class unloading and weak root cleaning 476 void parallel_cleaning(bool full_gc); 477 478 private: 479 void stw_unload_classes(bool full_gc); 480 void stw_process_weak_roots(bool full_gc); 481 void stw_weak_refs(bool full_gc); 482 483 // Heap iteration support 484 void scan_roots_for_iteration(ShenandoahScanObjectStack* oop_stack, ObjectIterateScanRootClosure* oops); 485 bool prepare_aux_bitmap_for_iteration(); 486 void reclaim_aux_bitmap_for_iteration(); 487 488 // ---------- Generic interface hooks 489 // Minor things that super-interface expects us to implement to play nice with 490 // the rest of runtime. Some of the things here are not required to be implemented, 491 // and can be stubbed out. 492 // 493 public: 494 bool is_maximal_no_gc() const override shenandoah_not_implemented_return(false); 495 496 // Check the pointer is in active part of Java heap. 497 // Use is_in_reserved to check if object is within heap bounds. 498 bool is_in(const void* p) const override; 499 500 bool requires_barriers(stackChunkOop obj) const override; 501 502 MemRegion reserved_region() const { return _reserved; } 503 bool is_in_reserved(const void* addr) const { return _reserved.contains(addr); } 504 505 void collect(GCCause::Cause cause) override; 506 void do_full_collection(bool clear_all_soft_refs) override; 507 508 // Used for parsing heap during error printing 509 HeapWord* block_start(const void* addr) const; 510 bool block_is_obj(const HeapWord* addr) const; 511 bool print_location(outputStream* st, void* addr) const override; 512 513 // Used for native heap walkers: heap dumpers, mostly 514 void object_iterate(ObjectClosure* cl) override; 515 // Parallel heap iteration support 516 ParallelObjectIteratorImpl* parallel_object_iterator(uint workers) override; 517 518 // Keep alive an object that was loaded with AS_NO_KEEPALIVE. 519 void keep_alive(oop obj) override; 520 521 // ---------- Safepoint interface hooks 522 // 523 public: 524 void safepoint_synchronize_begin() override; 525 void safepoint_synchronize_end() override; 526 527 // ---------- Code roots handling hooks 528 // 529 public: 530 void register_nmethod(nmethod* nm) override; 531 void unregister_nmethod(nmethod* nm) override; 532 void verify_nmethod(nmethod* nm) override {} 533 534 // ---------- Pinning hooks 535 // 536 public: 537 // Shenandoah supports per-object (per-region) pinning 538 void pin_object(JavaThread* thread, oop obj) override; 539 void unpin_object(JavaThread* thread, oop obj) override; 540 541 void sync_pinned_region_status(); 542 void assert_pinned_region_status() NOT_DEBUG_RETURN; 543 544 // ---------- CDS archive support 545 546 bool can_load_archived_objects() const override { return UseCompressedOops; } 547 HeapWord* allocate_loaded_archive_space(size_t size) override; 548 void complete_loaded_archive_space(MemRegion archive_space) override; 549 550 // ---------- Allocation support 551 // 552 private: 553 HeapWord* allocate_memory_under_lock(ShenandoahAllocRequest& request, bool& in_new_region); 554 inline HeapWord* allocate_from_gclab(Thread* thread, size_t size); 555 HeapWord* allocate_from_gclab_slow(Thread* thread, size_t size); 556 HeapWord* allocate_new_gclab(size_t min_size, size_t word_size, size_t* actual_size); 557 558 public: 559 HeapWord* allocate_memory(ShenandoahAllocRequest& request); 560 HeapWord* mem_allocate(size_t size, bool* what) override; 561 MetaWord* satisfy_failed_metadata_allocation(ClassLoaderData* loader_data, 562 size_t size, 563 Metaspace::MetadataType mdtype) override; 564 565 void notify_mutator_alloc_words(size_t words, bool waste); 566 567 HeapWord* allocate_new_tlab(size_t min_size, size_t requested_size, size_t* actual_size) override; 568 size_t tlab_capacity(Thread *thr) const override; 569 size_t unsafe_max_tlab_alloc(Thread *thread) const override; 570 size_t max_tlab_size() const override; 571 size_t tlab_used(Thread* ignored) const override; 572 573 void ensure_parsability(bool retire_labs) override; 574 575 void labs_make_parsable(); 576 void tlabs_retire(bool resize); 577 void gclabs_retire(bool resize); 578 579 // ---------- Marking support 580 // 581 private: 582 ShenandoahMarkingContext* _marking_context; 583 MemRegion _bitmap_region; 584 MemRegion _aux_bitmap_region; 585 MarkBitMap _verification_bit_map; 586 MarkBitMap _aux_bit_map; 587 588 size_t _bitmap_size; 589 size_t _bitmap_regions_per_slice; 590 size_t _bitmap_bytes_per_slice; 591 592 size_t _pretouch_heap_page_size; 593 size_t _pretouch_bitmap_page_size; 594 595 bool _bitmap_region_special; 596 bool _aux_bitmap_region_special; 597 598 ShenandoahLiveData** _liveness_cache; 599 600 public: 601 inline ShenandoahMarkingContext* complete_marking_context() const; 602 inline ShenandoahMarkingContext* marking_context() const; 603 inline void mark_complete_marking_context(); 604 inline void mark_incomplete_marking_context(); 605 606 template<class T> 607 inline void marked_object_iterate(ShenandoahHeapRegion* region, T* cl); 608 609 template<class T> 610 inline void marked_object_iterate(ShenandoahHeapRegion* region, T* cl, HeapWord* limit); 611 612 template<class T> 613 inline void marked_object_oop_iterate(ShenandoahHeapRegion* region, T* cl, HeapWord* limit); 614 615 void reset_mark_bitmap(); 616 617 // SATB barriers hooks 618 inline bool requires_marking(const void* entry) const; 619 620 // Support for bitmap uncommits 621 bool commit_bitmap_slice(ShenandoahHeapRegion *r); 622 bool uncommit_bitmap_slice(ShenandoahHeapRegion *r); 623 bool is_bitmap_slice_committed(ShenandoahHeapRegion* r, bool skip_self = false); 624 625 // Liveness caching support 626 ShenandoahLiveData* get_liveness_cache(uint worker_id); 627 void flush_liveness_cache(uint worker_id); 628 629 size_t pretouch_heap_page_size() { return _pretouch_heap_page_size; } 630 631 // ---------- Evacuation support 632 // 633 private: 634 ShenandoahCollectionSet* _collection_set; 635 ShenandoahEvacOOMHandler _oom_evac_handler; 636 637 public: 638 static address in_cset_fast_test_addr(); 639 640 ShenandoahCollectionSet* collection_set() const { return _collection_set; } 641 642 // Checks if object is in the collection set. 643 inline bool in_collection_set(oop obj) const; 644 645 // Checks if location is in the collection set. Can be interior pointer, not the oop itself. 646 inline bool in_collection_set_loc(void* loc) const; 647 648 // Evacuates object src. Returns the evacuated object, either evacuated 649 // by this thread, or by some other thread. 650 oop evacuate_object(oop src, Thread* thread); 651 652 // Call before/after evacuation. 653 inline void enter_evacuation(Thread* t); 654 inline void leave_evacuation(Thread* t); 655 656 // ---------- Helper functions 657 // 658 public: 659 template <class T> 660 inline void conc_update_with_forwarded(T* p); 661 662 template <class T> 663 inline void update_with_forwarded(T* p); 664 665 static inline void atomic_update_oop(oop update, oop* addr, oop compare); 666 static inline void atomic_update_oop(oop update, narrowOop* addr, oop compare); 667 static inline void atomic_update_oop(oop update, narrowOop* addr, narrowOop compare); 668 669 static inline bool atomic_update_oop_check(oop update, oop* addr, oop compare); 670 static inline bool atomic_update_oop_check(oop update, narrowOop* addr, oop compare); 671 static inline bool atomic_update_oop_check(oop update, narrowOop* addr, narrowOop compare); 672 673 static inline void atomic_clear_oop( oop* addr, oop compare); 674 static inline void atomic_clear_oop(narrowOop* addr, oop compare); 675 static inline void atomic_clear_oop(narrowOop* addr, narrowOop compare); 676 677 void trash_humongous_region_at(ShenandoahHeapRegion *r); 678 679 private: 680 void trash_cset_regions(); 681 682 // ---------- Testing helpers functions 683 // 684 private: 685 ShenandoahSharedFlag _inject_alloc_failure; 686 687 void try_inject_alloc_failure(); 688 bool should_inject_alloc_failure(); 689 }; 690 691 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHHEAP_HPP