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