1 /*
2 * Copyright (c) 2013, 2019, Red Hat, Inc. All rights reserved.
3 *
4 * This code is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 only, as
6 * published by the Free Software Foundation.
7 *
8 * This code is distributed in the hope that it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
11 * version 2 for more details (a copy is included in the LICENSE file that
12 * accompanied this code).
13 *
14 * You should have received a copy of the GNU General Public License version
15 * 2 along with this work; if not, write to the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
17 *
18 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
19 * or visit www.oracle.com if you need additional information or have any
20 * questions.
21 *
22 */
23
24 #ifndef SHARE_GC_SHENANDOAH_SHENANDOAHHEAP_HPP
25 #define SHARE_GC_SHENANDOAH_SHENANDOAHHEAP_HPP
26
27 #include "gc/shared/markBitMap.hpp"
28 #include "gc/shared/softRefPolicy.hpp"
29 #include "gc/shared/collectedHeap.hpp"
30 #include "gc/shenandoah/shenandoahAsserts.hpp"
31 #include "gc/shenandoah/shenandoahAllocRequest.hpp"
32 #include "gc/shenandoah/shenandoahLock.hpp"
33 #include "gc/shenandoah/shenandoahEvacOOMHandler.hpp"
34 #include "gc/shenandoah/shenandoahSharedVariables.hpp"
35 #include "services/memoryManager.hpp"
36
37 class ConcurrentGCTimer;
38 class ReferenceProcessor;
39 class ShenandoahAllocTracker;
40 class ShenandoahCollectorPolicy;
41 class ShenandoahControlThread;
42 class ShenandoahGCSession;
43 class ShenandoahGCStateResetter;
44 class ShenandoahHeuristics;
45 class ShenandoahMarkingContext;
46 class ShenandoahMarkCompact;
47 class ShenandoahMode;
48 class ShenandoahPhaseTimings;
49 class ShenandoahHeap;
50 class ShenandoahHeapRegion;
51 class ShenandoahHeapRegionClosure;
52 class ShenandoahCollectionSet;
53 class ShenandoahFreeSet;
54 class ShenandoahConcurrentMark;
55 class ShenandoahMarkCompact;
56 class ShenandoahMonitoringSupport;
57 class ShenandoahPacer;
58 class ShenandoahTraversalGC;
59 class ShenandoahVerifier;
60 class ShenandoahWorkGang;
61 class VMStructs;
62
63 class ShenandoahRegionIterator : public StackObj {
64 private:
65 ShenandoahHeap* _heap;
66
67 DEFINE_PAD_MINUS_SIZE(0, DEFAULT_CACHE_LINE_SIZE, sizeof(volatile size_t));
68 volatile size_t _index;
69 DEFINE_PAD_MINUS_SIZE(1, DEFAULT_CACHE_LINE_SIZE, 0);
70
71 // No implicit copying: iterators should be passed by reference to capture the state
72 ShenandoahRegionIterator(const ShenandoahRegionIterator& that);
73 ShenandoahRegionIterator& operator=(const ShenandoahRegionIterator& o);
74
75 public:
76 ShenandoahRegionIterator();
77 ShenandoahRegionIterator(ShenandoahHeap* heap);
78
79 // Reset iterator to default state
80 void reset();
81
82 // Returns next region, or NULL if there are no more regions.
83 // This is multi-thread-safe.
84 inline ShenandoahHeapRegion* next();
85
86 // This is *not* MT safe. However, in the absence of multithreaded access, it
87 // can be used to determine if there is more work to do.
88 bool has_next() const;
89 };
90
91 class ShenandoahHeapRegionClosure : public StackObj {
92 public:
93 virtual void heap_region_do(ShenandoahHeapRegion* r) = 0;
94 virtual bool is_thread_safe() { return false; }
95 };
96
97 #ifdef ASSERT
98 class ShenandoahAssertToSpaceClosure : public OopClosure {
99 private:
100 template <class T>
101 void do_oop_work(T* p);
102 public:
103 void do_oop(narrowOop* p);
104 void do_oop(oop* p);
105 };
106 #endif
107
108 typedef ShenandoahLock ShenandoahHeapLock;
109 typedef ShenandoahLocker ShenandoahHeapLocker;
110
111 // Shenandoah GC is low-pause concurrent GC that uses Brooks forwarding pointers
112 // to encode forwarding data. See BrooksPointer for details on forwarding data encoding.
113 // See ShenandoahControlThread for GC cycle structure.
114 //
115 class ShenandoahHeap : public CollectedHeap {
116 friend class ShenandoahAsserts;
117 friend class VMStructs;
118 friend class ShenandoahGCSession;
119 friend class ShenandoahGCStateResetter;
120
121 // ---------- Locks that guard important data structures in Heap
122 //
123 private:
124 ShenandoahHeapLock _lock;
125
126 public:
127 ShenandoahHeapLock* lock() {
128 return &_lock;
129 }
130
131 void assert_heaplock_owned_by_current_thread() NOT_DEBUG_RETURN;
132 void assert_heaplock_not_owned_by_current_thread() NOT_DEBUG_RETURN;
133 void assert_heaplock_or_safepoint() NOT_DEBUG_RETURN;
134
135 // ---------- Initialization, termination, identification, printing routines
136 //
137 public:
138 static ShenandoahHeap* heap();
139 static ShenandoahHeap* heap_no_check();
140
141 const char* name() const { return "Shenandoah"; }
142 ShenandoahHeap::Name kind() const { return CollectedHeap::Shenandoah; }
143
144 ShenandoahHeap(ShenandoahCollectorPolicy* policy);
145 jint initialize();
146 void post_initialize();
147 void initialize_heuristics();
148
149 void initialize_serviceability();
150
151 void print_on(outputStream* st) const;
152 void print_extended_on(outputStream *st) const;
153 void print_tracing_info() const;
154 void print_gc_threads_on(outputStream* st) const;
155 void print_heap_regions_on(outputStream* st) const;
156
157 void stop();
158
159 void prepare_for_verify();
160 void verify(VerifyOption vo);
161
162 // ---------- Heap counters and metrics
163 //
164 private:
165 size_t _initial_size;
166 size_t _minimum_size;
167 DEFINE_PAD_MINUS_SIZE(0, DEFAULT_CACHE_LINE_SIZE, sizeof(volatile size_t));
168 volatile size_t _used;
169 volatile size_t _committed;
170 volatile size_t _bytes_allocated_since_gc_start;
171 DEFINE_PAD_MINUS_SIZE(1, DEFAULT_CACHE_LINE_SIZE, 0);
172
173 public:
174 void increase_used(size_t bytes);
175 void decrease_used(size_t bytes);
176 void set_used(size_t bytes);
177
178 void increase_committed(size_t bytes);
179 void decrease_committed(size_t bytes);
180 void increase_allocated(size_t bytes);
181
182 size_t bytes_allocated_since_gc_start();
183 void reset_bytes_allocated_since_gc_start();
184
185 size_t min_capacity() const;
186 size_t max_capacity() const;
187 size_t initial_capacity() const;
188 size_t capacity() const;
189 size_t used() const;
190 size_t committed() const;
191
192 // ---------- Workers handling
193 //
194 private:
195 uint _max_workers;
196 ShenandoahWorkGang* _workers;
197 ShenandoahWorkGang* _safepoint_workers;
198
199 public:
200 uint max_workers();
201 void assert_gc_workers(uint nworker) NOT_DEBUG_RETURN;
202
203 WorkGang* workers() const;
204 WorkGang* get_safepoint_workers();
205
206 void gc_threads_do(ThreadClosure* tcl) const;
207
208 // ---------- Heap regions handling machinery
209 //
210 private:
211 MemRegion _heap_region;
212 bool _heap_region_special;
213 size_t _num_regions;
214 ShenandoahHeapRegion** _regions;
215 ShenandoahRegionIterator _update_refs_iterator;
216
217 public:
218
219 inline HeapWord* base() const { return _heap_region.start(); }
220
221 inline size_t num_regions() const { return _num_regions; }
222 inline bool is_heap_region_special() { return _heap_region_special; }
223
224 inline ShenandoahHeapRegion* const heap_region_containing(const void* addr) const;
225 inline size_t heap_region_index_containing(const void* addr) const;
226
227 inline ShenandoahHeapRegion* const get_region(size_t region_idx) const;
228
229 void heap_region_iterate(ShenandoahHeapRegionClosure* blk) const;
230 void parallel_heap_region_iterate(ShenandoahHeapRegionClosure* blk) const;
231
232 // ---------- GC state machinery
233 //
234 // GC state describes the important parts of collector state, that may be
235 // used to make barrier selection decisions in the native and generated code.
236 // Multiple bits can be set at once.
237 //
238 // Important invariant: when GC state is zero, the heap is stable, and no barriers
239 // are required.
240 //
241 public:
242 enum GCStateBitPos {
243 // Heap has forwarded objects: needs LRB barriers.
244 HAS_FORWARDED_BITPOS = 0,
245
246 // Heap is under marking: needs SATB barriers.
247 MARKING_BITPOS = 1,
248
249 // Heap is under evacuation: needs LRB barriers. (Set together with HAS_FORWARDED)
250 EVACUATION_BITPOS = 2,
251
252 // Heap is under updating: needs no additional barriers.
253 UPDATEREFS_BITPOS = 3,
254
255 // Heap is under traversal collection
256 TRAVERSAL_BITPOS = 4
257 };
258
259 enum GCState {
260 STABLE = 0,
261 HAS_FORWARDED = 1 << HAS_FORWARDED_BITPOS,
262 MARKING = 1 << MARKING_BITPOS,
263 EVACUATION = 1 << EVACUATION_BITPOS,
264 UPDATEREFS = 1 << UPDATEREFS_BITPOS,
265 TRAVERSAL = 1 << TRAVERSAL_BITPOS
266 };
267
268 private:
269 ShenandoahSharedBitmap _gc_state;
270 ShenandoahSharedFlag _degenerated_gc_in_progress;
271 ShenandoahSharedFlag _full_gc_in_progress;
272 ShenandoahSharedFlag _full_gc_move_in_progress;
273 ShenandoahSharedFlag _progress_last_gc;
274
275 void set_gc_state_all_threads(char state);
276 void set_gc_state_mask(uint mask, bool value);
277
278 public:
279 char gc_state() const;
280 static address gc_state_addr();
281
282 void set_concurrent_mark_in_progress(bool in_progress);
283 void set_evacuation_in_progress(bool in_progress);
284 void set_update_refs_in_progress(bool in_progress);
285 void set_degenerated_gc_in_progress(bool in_progress);
286 void set_full_gc_in_progress(bool in_progress);
287 void set_full_gc_move_in_progress(bool in_progress);
288 void set_concurrent_traversal_in_progress(bool in_progress);
289 void set_has_forwarded_objects(bool cond);
290
291 inline bool is_stable() const;
292 inline bool is_idle() const;
293 inline bool is_concurrent_mark_in_progress() const;
294 inline bool is_update_refs_in_progress() const;
295 inline bool is_evacuation_in_progress() const;
296 inline bool is_degenerated_gc_in_progress() const;
297 inline bool is_full_gc_in_progress() const;
298 inline bool is_full_gc_move_in_progress() const;
299 inline bool is_concurrent_traversal_in_progress() const;
300 inline bool has_forwarded_objects() const;
301 inline bool is_gc_in_progress_mask(uint mask) const;
302
303 // ---------- GC cancellation and degeneration machinery
304 //
305 // Cancelled GC flag is used to notify concurrent phases that they should terminate.
306 //
307 public:
308 enum ShenandoahDegenPoint {
309 _degenerated_unset,
310 _degenerated_traversal,
311 _degenerated_outside_cycle,
312 _degenerated_mark,
313 _degenerated_evac,
314 _degenerated_updaterefs,
315 _DEGENERATED_LIMIT
316 };
317
318 static const char* degen_point_to_string(ShenandoahDegenPoint point) {
319 switch (point) {
320 case _degenerated_unset:
321 return "<UNSET>";
322 case _degenerated_traversal:
323 return "Traversal";
324 case _degenerated_outside_cycle:
325 return "Outside of Cycle";
326 case _degenerated_mark:
327 return "Mark";
328 case _degenerated_evac:
329 return "Evacuation";
330 case _degenerated_updaterefs:
331 return "Update Refs";
332 default:
333 ShouldNotReachHere();
334 return "ERROR";
335 }
336 };
337
338 private:
339 enum CancelState {
340 // Normal state. GC has not been cancelled and is open for cancellation.
341 // Worker threads can suspend for safepoint.
342 CANCELLABLE,
343
344 // GC has been cancelled. Worker threads can not suspend for
345 // safepoint but must finish their work as soon as possible.
346 CANCELLED,
347
348 // GC has not been cancelled and must not be cancelled. At least
349 // one worker thread checks for pending safepoint and may suspend
350 // if a safepoint is pending.
351 NOT_CANCELLED
352 };
353
354 ShenandoahSharedEnumFlag<CancelState> _cancelled_gc;
355 bool try_cancel_gc();
356
357 public:
358 static address cancelled_gc_addr();
359
360 inline bool cancelled_gc() const;
361 inline bool check_cancelled_gc_and_yield(bool sts_active = true);
362
363 inline void clear_cancelled_gc();
364
365 void cancel_gc(GCCause::Cause cause);
366
367 // ---------- GC operations entry points
368 //
369 public:
370 // Entry points to STW GC operations, these cause a related safepoint, that then
371 // call the entry method below
372 void vmop_entry_init_mark();
373 void vmop_entry_final_mark();
374 void vmop_entry_final_evac();
375 void vmop_entry_init_updaterefs();
376 void vmop_entry_final_updaterefs();
377 void vmop_entry_init_traversal();
378 void vmop_entry_final_traversal();
379 void vmop_entry_full(GCCause::Cause cause);
380 void vmop_degenerated(ShenandoahDegenPoint point);
381
382 // Entry methods to normally STW GC operations. These set up logging, monitoring
383 // and workers for net VM operation
384 void entry_init_mark();
385 void entry_final_mark();
386 void entry_final_evac();
387 void entry_init_updaterefs();
388 void entry_final_updaterefs();
389 void entry_init_traversal();
390 void entry_final_traversal();
391 void entry_full(GCCause::Cause cause);
392 void entry_degenerated(int point);
393
394 // Entry methods to normally concurrent GC operations. These set up logging, monitoring
395 // for concurrent operation.
396 void entry_reset();
397 void entry_mark();
398 void entry_preclean();
399 void entry_roots();
400 void entry_cleanup();
401 void entry_evac();
402 void entry_updaterefs();
403 void entry_traversal();
404 void entry_uncommit(double shrink_before);
405
406 private:
407 // Actual work for the phases
408 void op_init_mark();
409 void op_final_mark();
410 void op_final_evac();
411 void op_init_updaterefs();
412 void op_final_updaterefs();
413 void op_init_traversal();
414 void op_final_traversal();
415 void op_full(GCCause::Cause cause);
416 void op_degenerated(ShenandoahDegenPoint point);
417 void op_degenerated_fail();
418 void op_degenerated_futile();
419
420 void op_reset();
421 void op_mark();
422 void op_preclean();
423 void op_roots();
424 void op_cleanup();
425 void op_conc_evac();
426 void op_stw_evac();
427 void op_updaterefs();
428 void op_traversal();
429 void op_uncommit(double shrink_before);
430
431 // Messages for GC trace events, they have to be immortal for
432 // passing around the logging/tracing systems
433 const char* init_mark_event_message() const;
434 const char* final_mark_event_message() const;
435 const char* conc_mark_event_message() const;
436 const char* degen_event_message(ShenandoahDegenPoint point) const;
437
438 // ---------- GC subsystems
439 //
440 private:
441 ShenandoahControlThread* _control_thread;
442 ShenandoahCollectorPolicy* _shenandoah_policy;
443 ShenandoahMode* _gc_mode;
444 ShenandoahHeuristics* _heuristics;
445 ShenandoahFreeSet* _free_set;
446 ShenandoahConcurrentMark* _scm;
447 ShenandoahTraversalGC* _traversal_gc;
448 ShenandoahMarkCompact* _full_gc;
449 ShenandoahPacer* _pacer;
450 ShenandoahVerifier* _verifier;
451
452 ShenandoahAllocTracker* _alloc_tracker;
453 ShenandoahPhaseTimings* _phase_timings;
454
455 ShenandoahControlThread* control_thread() { return _control_thread; }
456 ShenandoahMarkCompact* full_gc() { return _full_gc; }
457
458 public:
459 ShenandoahCollectorPolicy* shenandoah_policy() const { return _shenandoah_policy; }
460 ShenandoahHeuristics* heuristics() const { return _heuristics; }
461 ShenandoahFreeSet* free_set() const { return _free_set; }
462 ShenandoahConcurrentMark* concurrent_mark() { return _scm; }
463 ShenandoahTraversalGC* traversal_gc() const { return _traversal_gc; }
464 bool is_traversal_mode() const { return _traversal_gc != NULL; }
465 ShenandoahPacer* pacer() const { return _pacer; }
466
467 ShenandoahPhaseTimings* phase_timings() const { return _phase_timings; }
468 ShenandoahAllocTracker* alloc_tracker() const { return _alloc_tracker; }
469
470 ShenandoahVerifier* verifier();
471
472 // ---------- VM subsystem bindings
473 //
474 private:
475 ShenandoahMonitoringSupport* _monitoring_support;
476 MemoryPool* _memory_pool;
477 GCMemoryManager _stw_memory_manager;
478 GCMemoryManager _cycle_memory_manager;
479 ConcurrentGCTimer* _gc_timer;
480 SoftRefPolicy _soft_ref_policy;
481
482 // For exporting to SA
483 int _log_min_obj_alignment_in_bytes;
484 public:
485 ShenandoahMonitoringSupport* monitoring_support() { return _monitoring_support; }
486 GCMemoryManager* cycle_memory_manager() { return &_cycle_memory_manager; }
487 GCMemoryManager* stw_memory_manager() { return &_stw_memory_manager; }
488 SoftRefPolicy* soft_ref_policy() { return &_soft_ref_policy; }
489
490 GrowableArray<GCMemoryManager*> memory_managers();
491 GrowableArray<MemoryPool*> memory_pools();
492 MemoryUsage memory_usage();
493 GCTracer* tracer();
494 GCTimer* gc_timer() const;
495
496 // ---------- Reference processing
497 //
498 private:
499 AlwaysTrueClosure _subject_to_discovery;
500 ReferenceProcessor* _ref_processor;
501 ShenandoahSharedFlag _process_references;
502
503 void ref_processing_init();
504
505 public:
506 ReferenceProcessor* ref_processor() { return _ref_processor; }
507 void set_process_references(bool pr);
508 bool process_references() const;
509
510 // ---------- Class Unloading
511 //
512 private:
513 ShenandoahSharedFlag _unload_classes;
514
515 public:
516 void set_unload_classes(bool uc);
517 bool unload_classes() const;
518
519 // Perform STW class unloading and weak root cleaning
520 void parallel_cleaning(bool full_gc);
521
522 private:
523 void stw_unload_classes(bool full_gc);
524 void stw_process_weak_roots(bool full_gc);
525
526 // ---------- Generic interface hooks
527 // Minor things that super-interface expects us to implement to play nice with
528 // the rest of runtime. Some of the things here are not required to be implemented,
529 // and can be stubbed out.
530 //
531 public:
532 AdaptiveSizePolicy* size_policy() shenandoah_not_implemented_return(NULL);
533 bool is_maximal_no_gc() const shenandoah_not_implemented_return(false);
534
535 bool is_in(const void* p) const;
536
537 MemRegion reserved_region() const { return _reserved; }
538 bool is_in_reserved(const void* addr) const { return _reserved.contains(addr); }
539
540 void collect(GCCause::Cause cause);
541 void do_full_collection(bool clear_all_soft_refs);
542
543 // Used for parsing heap during error printing
544 HeapWord* block_start(const void* addr) const;
545 bool block_is_obj(const HeapWord* addr) const;
546 bool print_location(outputStream* st, void* addr) const;
547
548 // Used for native heap walkers: heap dumpers, mostly
549 void object_iterate(ObjectClosure* cl);
550 void safe_object_iterate(ObjectClosure* cl);
551
552 // Used by RMI
553 jlong millis_since_last_gc();
554
555 // ---------- Safepoint interface hooks
556 //
557 public:
558 void safepoint_synchronize_begin();
559 void safepoint_synchronize_end();
560
561 // ---------- Code roots handling hooks
562 //
563 public:
564 void register_nmethod(nmethod* nm);
565 void unregister_nmethod(nmethod* nm);
566 void flush_nmethod(nmethod* nm) {}
567 void verify_nmethod(nmethod* nm) {}
568
569 // ---------- Pinning hooks
570 //
571 public:
572 // Shenandoah supports per-object (per-region) pinning
573 bool supports_object_pinning() const { return true; }
574
575 oop pin_object(JavaThread* thread, oop obj);
576 void unpin_object(JavaThread* thread, oop obj);
577
578 void sync_pinned_region_status();
579 void assert_pinned_region_status() NOT_DEBUG_RETURN;
580
581 // ---------- Allocation support
582 //
583 private:
584 HeapWord* allocate_memory_under_lock(ShenandoahAllocRequest& request, bool& in_new_region);
585 inline HeapWord* allocate_from_gclab(Thread* thread, size_t size);
586 HeapWord* allocate_from_gclab_slow(Thread* thread, size_t size);
587 HeapWord* allocate_new_gclab(size_t min_size, size_t word_size, size_t* actual_size);
588 void retire_and_reset_gclabs();
589
590 public:
591 HeapWord* allocate_memory(ShenandoahAllocRequest& request);
592 HeapWord* mem_allocate(size_t size, bool* what);
593 MetaWord* satisfy_failed_metadata_allocation(ClassLoaderData* loader_data,
594 size_t size,
595 Metaspace::MetadataType mdtype);
596
597 void notify_mutator_alloc_words(size_t words, bool waste);
598
599 // Shenandoah supports TLAB allocation
600 bool supports_tlab_allocation() const { return true; }
601
602 HeapWord* allocate_new_tlab(size_t min_size, size_t requested_size, size_t* actual_size);
603 size_t tlab_capacity(Thread *thr) const;
604 size_t unsafe_max_tlab_alloc(Thread *thread) const;
605 size_t max_tlab_size() const;
606 size_t tlab_used(Thread* ignored) const;
607
608 void resize_tlabs();
609
610 void ensure_parsability(bool retire_tlabs);
611 void make_parsable(bool retire_tlabs);
612
613 // ---------- Marking support
614 //
615 private:
616 ShenandoahMarkingContext* _marking_context;
617 MemRegion _bitmap_region;
618 MemRegion _aux_bitmap_region;
619 MarkBitMap _verification_bit_map;
620 MarkBitMap _aux_bit_map;
621
622 size_t _bitmap_size;
623 size_t _bitmap_regions_per_slice;
624 size_t _bitmap_bytes_per_slice;
625
626 bool _bitmap_region_special;
627 bool _aux_bitmap_region_special;
628
629 // Used for buffering per-region liveness data.
630 // Needed since ShenandoahHeapRegion uses atomics to update liveness.
631 //
632 // The array has max-workers elements, each of which is an array of
633 // jushort * max_regions. The choice of jushort is not accidental:
634 // there is a tradeoff between static/dynamic footprint that translates
635 // into cache pressure (which is already high during marking), and
636 // too many atomic updates. size_t/jint is too large, jbyte is too small.
637 jushort** _liveness_cache;
638
639 public:
640 inline ShenandoahMarkingContext* complete_marking_context() const;
641 inline ShenandoahMarkingContext* marking_context() const;
642 inline void mark_complete_marking_context();
643 inline void mark_incomplete_marking_context();
644
645 template<class T>
646 inline void marked_object_iterate(ShenandoahHeapRegion* region, T* cl);
647
648 template<class T>
649 inline void marked_object_iterate(ShenandoahHeapRegion* region, T* cl, HeapWord* limit);
650
651 template<class T>
652 inline void marked_object_oop_iterate(ShenandoahHeapRegion* region, T* cl, HeapWord* limit);
653
654 void reset_mark_bitmap();
655
656 // SATB barriers hooks
657 template<bool RESOLVE>
658 inline bool requires_marking(const void* entry) const;
659 void force_satb_flush_all_threads();
660
661 // Support for bitmap uncommits
662 bool commit_bitmap_slice(ShenandoahHeapRegion *r);
663 bool uncommit_bitmap_slice(ShenandoahHeapRegion *r);
664 bool is_bitmap_slice_committed(ShenandoahHeapRegion* r, bool skip_self = false);
665
666 // Liveness caching support
667 jushort* get_liveness_cache(uint worker_id);
668 void flush_liveness_cache(uint worker_id);
669
670 // ---------- Evacuation support
671 //
672 private:
673 ShenandoahCollectionSet* _collection_set;
674 ShenandoahEvacOOMHandler _oom_evac_handler;
675
676 void evacuate_and_update_roots();
677
678 public:
679 static address in_cset_fast_test_addr();
680
681 ShenandoahCollectionSet* collection_set() const { return _collection_set; }
682
683 template <class T>
684 inline bool in_collection_set(T obj) const;
685
686 // Avoid accidentally calling the method above with ShenandoahHeapRegion*, which would be *wrong*.
687 inline bool in_collection_set(ShenandoahHeapRegion* r) shenandoah_not_implemented_return(false);
688
689 // Evacuates object src. Returns the evacuated object, either evacuated
690 // by this thread, or by some other thread.
691 inline oop evacuate_object(oop src, Thread* thread);
692
693 // Call before/after evacuation.
694 void enter_evacuation();
695 void leave_evacuation();
696
697 // ---------- Helper functions
698 //
699 public:
700 template <class T>
701 inline oop evac_update_with_forwarded(T* p);
702
703 template <class T>
704 inline oop maybe_update_with_forwarded(T* p);
705
706 template <class T>
707 inline oop maybe_update_with_forwarded_not_null(T* p, oop obj);
708
709 template <class T>
710 inline oop update_with_forwarded_not_null(T* p, oop obj);
711
712 static inline oop cas_oop(oop n, narrowOop* addr, oop c);
713 static inline oop cas_oop(oop n, oop* addr, oop c);
714 static inline oop cas_oop(oop n, narrowOop* addr, narrowOop c);
715
716 void trash_humongous_region_at(ShenandoahHeapRegion *r);
717
718 void deduplicate_string(oop str);
719
720 private:
721 void trash_cset_regions();
722 void update_heap_references(bool concurrent);
723
724 // ---------- Testing helpers functions
725 //
726 private:
727 ShenandoahSharedFlag _inject_alloc_failure;
728
729 void try_inject_alloc_failure();
730 bool should_inject_alloc_failure();
731 };
732
733 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHHEAP_HPP