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 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 // ---------- Initialization, termination, identification, printing routines
132 //
133 public:
134 static ShenandoahHeap* heap();
135
136 const char* name() const { return "Shenandoah"; }
137 ShenandoahHeap::Name kind() const { return CollectedHeap::Shenandoah; }
138
139 ShenandoahHeap(ShenandoahCollectorPolicy* policy);
140 jint initialize();
141 void post_initialize();
142 void initialize_heuristics();
143
144 void initialize_serviceability();
145
146 void print_on(outputStream* st) const;
147 void print_extended_on(outputStream *st) const;
148 void print_tracing_info() const;
149 void print_heap_regions_on(outputStream* st) const;
150
151 void stop();
152
153 void prepare_for_verify();
154 void verify(VerifyOption vo);
155
156 // ---------- Heap counters and metrics
157 //
158 private:
159 size_t _initial_size;
160 size_t _minimum_size;
161 shenandoah_padding(0);
162 volatile size_t _used;
163 volatile size_t _committed;
164 volatile size_t _bytes_allocated_since_gc_start;
165 shenandoah_padding(1);
166
167 public:
168 void increase_used(size_t bytes);
169 void decrease_used(size_t bytes);
170 void set_used(size_t bytes);
171
172 void increase_committed(size_t bytes);
173 void decrease_committed(size_t bytes);
174 void increase_allocated(size_t bytes);
175
176 size_t bytes_allocated_since_gc_start();
177 void reset_bytes_allocated_since_gc_start();
178
179 size_t min_capacity() const;
180 size_t max_capacity() const;
181 size_t initial_capacity() const;
182 size_t capacity() const;
183 size_t used() const;
184 size_t committed() const;
185
186 // ---------- Workers handling
187 //
188 private:
189 uint _max_workers;
190 ShenandoahWorkGang* _workers;
191 ShenandoahWorkGang* _safepoint_workers;
192
193 public:
194 uint max_workers();
195 void assert_gc_workers(uint nworker) NOT_DEBUG_RETURN;
196
197 WorkGang* workers() const;
198 WorkGang* get_safepoint_workers();
199
200 void gc_threads_do(ThreadClosure* tcl) const;
201 // Runs the given AbstractGangTask with the current active workers.
202 virtual void run_task(AbstractGangTask* task);
203
204 // ---------- Heap regions handling machinery
205 //
206 private:
207 MemRegion _heap_region;
208 bool _heap_region_special;
209 size_t _num_regions;
210 ShenandoahHeapRegion** _regions;
211 ShenandoahRegionIterator _update_refs_iterator;
212
213 public:
214
215 inline HeapWord* base() const { return _heap_region.start(); }
216
217 inline size_t num_regions() const { return _num_regions; }
218 inline bool is_heap_region_special() { return _heap_region_special; }
219
220 inline ShenandoahHeapRegion* const heap_region_containing(const void* addr) const;
221 inline size_t heap_region_index_containing(const void* addr) const;
222
223 inline ShenandoahHeapRegion* const get_region(size_t region_idx) const;
224
225 void heap_region_iterate(ShenandoahHeapRegionClosure* blk) const;
226 void parallel_heap_region_iterate(ShenandoahHeapRegionClosure* blk) const;
227
228 // ---------- GC state machinery
229 //
230 // GC state describes the important parts of collector state, that may be
231 // used to make barrier selection decisions in the native and generated code.
232 // Multiple bits can be set at once.
233 //
234 // Important invariant: when GC state is zero, the heap is stable, and no barriers
235 // are required.
236 //
237 public:
238 enum GCStateBitPos {
239 // Heap has forwarded objects: needs LRB barriers.
240 HAS_FORWARDED_BITPOS = 0,
241
242 // Heap is under marking: needs SATB barriers.
243 MARKING_BITPOS = 1,
244
245 // Heap is under evacuation: needs LRB barriers. (Set together with HAS_FORWARDED)
246 EVACUATION_BITPOS = 2,
247
248 // Heap is under updating: needs no additional barriers.
249 UPDATEREFS_BITPOS = 3,
250 };
251
252 enum GCState {
253 STABLE = 0,
254 HAS_FORWARDED = 1 << HAS_FORWARDED_BITPOS,
255 MARKING = 1 << MARKING_BITPOS,
256 EVACUATION = 1 << EVACUATION_BITPOS,
257 UPDATEREFS = 1 << UPDATEREFS_BITPOS,
258 };
259
260 private:
261 ShenandoahSharedBitmap _gc_state;
262 ShenandoahSharedFlag _degenerated_gc_in_progress;
263 ShenandoahSharedFlag _full_gc_in_progress;
264 ShenandoahSharedFlag _full_gc_move_in_progress;
265 ShenandoahSharedFlag _progress_last_gc;
266 ShenandoahSharedFlag _concurrent_strong_root_in_progress;
267 ShenandoahSharedFlag _concurrent_weak_root_in_progress;
268
269 void set_gc_state_all_threads(char state);
270 void set_gc_state_mask(uint mask, bool value);
271
272 public:
273 char gc_state() const;
274 static address gc_state_addr();
275
276 void set_concurrent_mark_in_progress(bool in_progress);
277 void set_evacuation_in_progress(bool in_progress);
278 void set_update_refs_in_progress(bool in_progress);
279 void set_degenerated_gc_in_progress(bool in_progress);
280 void set_full_gc_in_progress(bool in_progress);
281 void set_full_gc_move_in_progress(bool in_progress);
282 void set_has_forwarded_objects(bool cond);
283 void set_concurrent_strong_root_in_progress(bool cond);
284 void set_concurrent_weak_root_in_progress(bool cond);
285
286 inline bool is_stable() const;
287 inline bool is_idle() const;
288 inline bool is_concurrent_mark_in_progress() const;
289 inline bool is_update_refs_in_progress() const;
290 inline bool is_evacuation_in_progress() const;
291 inline bool is_degenerated_gc_in_progress() const;
292 inline bool is_full_gc_in_progress() const;
293 inline bool is_full_gc_move_in_progress() const;
294 inline bool has_forwarded_objects() const;
295 inline bool is_gc_in_progress_mask(uint mask) const;
296 inline bool is_stw_gc_in_progress() const;
297 inline bool is_concurrent_strong_root_in_progress() const;
298 inline bool is_concurrent_weak_root_in_progress() 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_outside_cycle,
308 _degenerated_mark,
309 _degenerated_evac,
310 _degenerated_updaterefs,
311 _DEGENERATED_LIMIT
312 };
313
314 static const char* degen_point_to_string(ShenandoahDegenPoint point) {
315 switch (point) {
316 case _degenerated_unset:
317 return "<UNSET>";
318 case _degenerated_outside_cycle:
319 return "Outside of Cycle";
320 case _degenerated_mark:
321 return "Mark";
322 case _degenerated_evac:
323 return "Evacuation";
324 case _degenerated_updaterefs:
325 return "Update Refs";
326 default:
327 ShouldNotReachHere();
328 return "ERROR";
329 }
330 };
331
332 private:
333 enum CancelState {
334 // Normal state. GC has not been cancelled and is open for cancellation.
335 // Worker threads can suspend for safepoint.
336 CANCELLABLE,
337
338 // GC has been cancelled. Worker threads can not suspend for
339 // safepoint but must finish their work as soon as possible.
340 CANCELLED,
341
342 // GC has not been cancelled and must not be cancelled. At least
343 // one worker thread checks for pending safepoint and may suspend
344 // if a safepoint is pending.
345 NOT_CANCELLED
346 };
347
348 ShenandoahSharedEnumFlag<CancelState> _cancelled_gc;
349 bool try_cancel_gc();
350
351 public:
352 static address cancelled_gc_addr();
353
354 inline bool cancelled_gc() const;
355 inline bool check_cancelled_gc_and_yield(bool sts_active = true);
356
357 inline void clear_cancelled_gc();
358
359 void cancel_gc(GCCause::Cause cause);
360
361 // ---------- GC operations entry points
362 //
363 public:
364 // Entry points to STW GC operations, these cause a related safepoint, that then
365 // call the entry method below
366 void vmop_entry_init_mark();
367 void vmop_entry_final_mark();
368 void vmop_entry_init_updaterefs();
369 void vmop_entry_final_updaterefs();
370 void vmop_entry_full(GCCause::Cause cause);
371 void vmop_degenerated(ShenandoahDegenPoint point);
372
373 // Entry methods to normally STW GC operations. These set up logging, monitoring
374 // and workers for net VM operation
375 void entry_init_mark();
376 void entry_final_mark();
377 void entry_init_updaterefs();
378 void entry_final_updaterefs();
379 void entry_full(GCCause::Cause cause);
380 void entry_degenerated(int point);
381
382 // Entry methods to normally concurrent GC operations. These set up logging, monitoring
383 // for concurrent operation.
384 void entry_reset();
385 void entry_mark();
386 void entry_preclean();
387 void entry_weak_roots();
388 void entry_class_unloading();
389 void entry_strong_roots();
390 void entry_cleanup_early();
391 void entry_evac();
392 void entry_updaterefs();
393 void entry_cleanup_complete();
394 void entry_uncommit(double shrink_before);
395
396 private:
397 // Actual work for the phases
398 void op_init_mark();
399 void op_final_mark();
400 void op_init_updaterefs();
401 void op_final_updaterefs();
402 void op_full(GCCause::Cause cause);
403 void op_degenerated(ShenandoahDegenPoint point);
404 void op_degenerated_fail();
405 void op_degenerated_futile();
406
407 void op_reset();
408 void op_mark();
409 void op_preclean();
410 void op_weak_roots();
411 void op_class_unloading();
412 void op_strong_roots();
413 void op_cleanup_early();
414 void op_conc_evac();
415 void op_stw_evac();
416 void op_updaterefs();
417 void op_cleanup_complete();
418 void op_uncommit(double shrink_before);
419
420 // Messages for GC trace events, they have to be immortal for
421 // passing around the logging/tracing systems
422 const char* init_mark_event_message() const;
423 const char* final_mark_event_message() const;
424 const char* conc_mark_event_message() const;
425 const char* degen_event_message(ShenandoahDegenPoint point) const;
426
427 // ---------- GC subsystems
428 //
429 private:
430 ShenandoahControlThread* _control_thread;
431 ShenandoahCollectorPolicy* _shenandoah_policy;
432 ShenandoahMode* _gc_mode;
433 ShenandoahHeuristics* _heuristics;
434 ShenandoahFreeSet* _free_set;
435 ShenandoahConcurrentMark* _scm;
436 ShenandoahMarkCompact* _full_gc;
437 ShenandoahPacer* _pacer;
438 ShenandoahVerifier* _verifier;
439
440 ShenandoahPhaseTimings* _phase_timings;
441
442 ShenandoahControlThread* control_thread() { return _control_thread; }
443 ShenandoahMarkCompact* full_gc() { return _full_gc; }
444
445 public:
446 ShenandoahCollectorPolicy* shenandoah_policy() const { return _shenandoah_policy; }
447 ShenandoahMode* mode() const { return _gc_mode; }
448 ShenandoahHeuristics* heuristics() const { return _heuristics; }
449 ShenandoahFreeSet* free_set() const { return _free_set; }
450 ShenandoahConcurrentMark* concurrent_mark() { return _scm; }
451 ShenandoahPacer* pacer() const { return _pacer; }
452
453 ShenandoahPhaseTimings* phase_timings() const { return _phase_timings; }
454
455 ShenandoahVerifier* verifier();
456
457 // ---------- VM subsystem bindings
458 //
459 private:
460 ShenandoahMonitoringSupport* _monitoring_support;
461 MemoryPool* _memory_pool;
462 GCMemoryManager _stw_memory_manager;
463 GCMemoryManager _cycle_memory_manager;
464 ConcurrentGCTimer* _gc_timer;
465 SoftRefPolicy _soft_ref_policy;
466
467 // For exporting to SA
468 int _log_min_obj_alignment_in_bytes;
469 public:
470 ShenandoahMonitoringSupport* monitoring_support() { return _monitoring_support; }
471 GCMemoryManager* cycle_memory_manager() { return &_cycle_memory_manager; }
472 GCMemoryManager* stw_memory_manager() { return &_stw_memory_manager; }
473 SoftRefPolicy* soft_ref_policy() { return &_soft_ref_policy; }
474
475 GrowableArray<GCMemoryManager*> memory_managers();
476 GrowableArray<MemoryPool*> memory_pools();
477 MemoryUsage memory_usage();
478 GCTracer* tracer();
479 ConcurrentGCTimer* gc_timer() const;
480
481 // ---------- Reference processing
482 //
483 private:
484 AlwaysTrueClosure _subject_to_discovery;
485 ReferenceProcessor* _ref_processor;
486 ShenandoahSharedFlag _process_references;
487 bool _ref_proc_mt_discovery;
488 bool _ref_proc_mt_processing;
489
490 void ref_processing_init();
491
492 public:
493 ReferenceProcessor* ref_processor() { return _ref_processor; }
494 bool ref_processor_mt_discovery() { return _ref_proc_mt_discovery; }
495 bool ref_processor_mt_processing() { return _ref_proc_mt_processing; }
496 void set_process_references(bool pr);
497 bool process_references() const;
498
499 // ---------- Class Unloading
500 //
501 private:
502 ShenandoahSharedFlag _unload_classes;
503 ShenandoahUnload _unloader;
504
505 public:
506 void set_unload_classes(bool uc);
507 bool unload_classes() const;
508
509 // Perform STW class unloading and weak root cleaning
510 void parallel_cleaning(bool full_gc);
511
512 private:
513 void stw_unload_classes(bool full_gc);
514 void stw_process_weak_roots(bool full_gc);
515
516 // Prepare concurrent root processing
517 void prepare_concurrent_roots();
518 // Prepare and finish concurrent unloading
519 void prepare_concurrent_unloading();
520 void finish_concurrent_unloading();
521
522 // ---------- Generic interface hooks
523 // Minor things that super-interface expects us to implement to play nice with
524 // the rest of runtime. Some of the things here are not required to be implemented,
525 // and can be stubbed out.
526 //
527 public:
528 AdaptiveSizePolicy* size_policy() shenandoah_not_implemented_return(NULL);
529 bool is_maximal_no_gc() const shenandoah_not_implemented_return(false);
530
531 bool is_in(const void* p) const;
532
533 MemRegion reserved_region() const { return _reserved; }
534 bool is_in_reserved(const void* addr) const { return _reserved.contains(addr); }
535
536 void collect(GCCause::Cause cause);
537 void do_full_collection(bool clear_all_soft_refs);
538
539 // Used for parsing heap during error printing
540 HeapWord* block_start(const void* addr) const;
541 bool block_is_obj(const HeapWord* addr) const;
542 bool print_location(outputStream* st, void* addr) const;
543
544 // Used for native heap walkers: heap dumpers, mostly
545 void object_iterate(ObjectClosure* cl);
546
547 // Keep alive an object that was loaded with AS_NO_KEEPALIVE.
548 void keep_alive(oop obj);
549
550 // ---------- Safepoint interface hooks
551 //
552 public:
553 void safepoint_synchronize_begin();
554 void safepoint_synchronize_end();
555
556 // ---------- Code roots handling hooks
557 //
558 public:
559 void register_nmethod(nmethod* nm);
560 void unregister_nmethod(nmethod* nm);
561 void flush_nmethod(nmethod* nm);
562 void verify_nmethod(nmethod* nm) {}
563
564 // ---------- Pinning hooks
565 //
566 public:
567 // Shenandoah supports per-object (per-region) pinning
568 bool supports_object_pinning() const { return true; }
569
570 oop pin_object(JavaThread* thread, oop obj);
571 void unpin_object(JavaThread* thread, oop obj);
572
573 void sync_pinned_region_status();
574 void assert_pinned_region_status() NOT_DEBUG_RETURN;
575
576 // ---------- Allocation support
577 //
578 private:
579 HeapWord* allocate_memory_under_lock(ShenandoahAllocRequest& request, bool& in_new_region);
580 inline HeapWord* allocate_from_gclab(Thread* thread, size_t size);
581 HeapWord* allocate_from_gclab_slow(Thread* thread, size_t size);
582 HeapWord* allocate_new_gclab(size_t min_size, size_t word_size, size_t* actual_size);
583
584 public:
585 HeapWord* allocate_memory(ShenandoahAllocRequest& request);
586 HeapWord* mem_allocate(size_t size, bool* what);
587 MetaWord* satisfy_failed_metadata_allocation(ClassLoaderData* loader_data,
588 size_t size,
589 Metaspace::MetadataType mdtype);
590
591 void notify_mutator_alloc_words(size_t words, bool waste);
592
593 // Shenandoah supports TLAB allocation
594 bool supports_tlab_allocation() const { return true; }
595
596 HeapWord* allocate_new_tlab(size_t min_size, size_t requested_size, size_t* actual_size);
597 size_t tlab_capacity(Thread *thr) const;
598 size_t unsafe_max_tlab_alloc(Thread *thread) const;
599 size_t max_tlab_size() const;
600 size_t tlab_used(Thread* ignored) const;
601
602 void ensure_parsability(bool retire_labs);
603
604 void labs_make_parsable();
605 void tlabs_retire(bool resize);
606 void gclabs_retire(bool resize);
607
608 // ---------- Marking support
609 //
610 private:
611 ShenandoahMarkingContext* _marking_context;
612 MemRegion _bitmap_region;
613 MemRegion _aux_bitmap_region;
614 MarkBitMap _verification_bit_map;
615 MarkBitMap _aux_bit_map;
616
617 size_t _bitmap_size;
618 size_t _bitmap_regions_per_slice;
619 size_t _bitmap_bytes_per_slice;
620
621 size_t _pretouch_heap_page_size;
622 size_t _pretouch_bitmap_page_size;
623
624 bool _bitmap_region_special;
625 bool _aux_bitmap_region_special;
626
627 ShenandoahLiveData** _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 inline bool requires_marking(const void* entry) const;
648 void force_satb_flush_all_threads();
649
650 // Support for bitmap uncommits
651 bool commit_bitmap_slice(ShenandoahHeapRegion *r);
652 bool uncommit_bitmap_slice(ShenandoahHeapRegion *r);
653 bool is_bitmap_slice_committed(ShenandoahHeapRegion* r, bool skip_self = false);
654
655 // Liveness caching support
656 ShenandoahLiveData* get_liveness_cache(uint worker_id);
657 void flush_liveness_cache(uint worker_id);
658
659 size_t pretouch_heap_page_size() { return _pretouch_heap_page_size; }
660
661 // ---------- Evacuation support
662 //
663 private:
664 ShenandoahCollectionSet* _collection_set;
665 ShenandoahEvacOOMHandler _oom_evac_handler;
666
667 void evacuate_and_update_roots();
668
669 public:
670 static address in_cset_fast_test_addr();
671
672 ShenandoahCollectionSet* collection_set() const { return _collection_set; }
673
674 // Checks if object is in the collection set.
675 inline bool in_collection_set(oop obj) const;
676
677 // Checks if location is in the collection set. Can be interior pointer, not the oop itself.
678 inline bool in_collection_set_loc(void* loc) const;
679
680 // Evacuates object src. Returns the evacuated object, either evacuated
681 // by this thread, or by some other thread.
682 inline oop evacuate_object(oop src, Thread* thread);
683
684 // Call before/after evacuation.
685 inline void enter_evacuation(Thread* t);
686 inline void leave_evacuation(Thread* t);
687
688 // ---------- Helper functions
689 //
690 public:
691 template <class T>
692 inline oop evac_update_with_forwarded(T* p);
693
694 template <class T>
695 inline oop maybe_update_with_forwarded(T* p);
696
697 template <class T>
698 inline oop maybe_update_with_forwarded_not_null(T* p, oop obj);
699
700 template <class T>
701 inline oop update_with_forwarded_not_null(T* p, oop obj);
702
703 static inline oop cas_oop(oop n, narrowOop* addr, oop c);
704 static inline oop cas_oop(oop n, oop* addr, oop c);
705 static inline oop cas_oop(oop n, narrowOop* addr, narrowOop c);
706
707 void trash_humongous_region_at(ShenandoahHeapRegion *r);
708
709 void deduplicate_string(oop str);
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