1 /*
2 * Copyright (c) 2013, 2018, 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_VM_GC_SHENANDOAH_SHENANDOAHHEAP_HPP
25 #define SHARE_VM_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 inline size_t num_regions() const { return _num_regions; }
219 inline bool is_heap_region_special() { return _heap_region_special; }
220
221 inline ShenandoahHeapRegion* const heap_region_containing(const void* addr) const;
222 inline size_t heap_region_index_containing(const void* addr) const;
223
224 inline ShenandoahHeapRegion* const get_region(size_t region_idx) const;
225
226 void heap_region_iterate(ShenandoahHeapRegionClosure* blk) const;
227 void parallel_heap_region_iterate(ShenandoahHeapRegionClosure* blk) const;
228
229 // ---------- GC state machinery
230 //
231 // GC state describes the important parts of collector state, that may be
232 // used to make barrier selection decisions in the native and generated code.
233 // Multiple bits can be set at once.
234 //
235 // Important invariant: when GC state is zero, the heap is stable, and no barriers
236 // are required.
237 //
238 public:
239 enum GCStateBitPos {
240 // Heap has forwarded objects: needs LRB barriers.
241 HAS_FORWARDED_BITPOS = 0,
242
243 // Heap is under marking: needs SATB barriers.
244 MARKING_BITPOS = 1,
245
246 // Heap is under evacuation: needs LRB barriers. (Set together with HAS_FORWARDED)
247 EVACUATION_BITPOS = 2,
248
249 // Heap is under updating: needs no additional barriers.
250 UPDATEREFS_BITPOS = 3,
251
252 // Heap is under traversal collection
253 TRAVERSAL_BITPOS = 4
254 };
255
256 enum GCState {
257 STABLE = 0,
258 HAS_FORWARDED = 1 << HAS_FORWARDED_BITPOS,
259 MARKING = 1 << MARKING_BITPOS,
260 EVACUATION = 1 << EVACUATION_BITPOS,
261 UPDATEREFS = 1 << UPDATEREFS_BITPOS,
262 TRAVERSAL = 1 << TRAVERSAL_BITPOS
263 };
264
265 private:
266 ShenandoahSharedBitmap _gc_state;
267 ShenandoahSharedFlag _degenerated_gc_in_progress;
268 ShenandoahSharedFlag _full_gc_in_progress;
269 ShenandoahSharedFlag _full_gc_move_in_progress;
270 ShenandoahSharedFlag _progress_last_gc;
271
272 void set_gc_state_all_threads(char state);
273 void set_gc_state_mask(uint mask, bool value);
274
275 public:
276 char gc_state() const;
277 static address gc_state_addr();
278
279 void set_concurrent_mark_in_progress(bool in_progress);
280 void set_evacuation_in_progress(bool in_progress);
281 void set_update_refs_in_progress(bool in_progress);
282 void set_degenerated_gc_in_progress(bool in_progress);
283 void set_full_gc_in_progress(bool in_progress);
284 void set_full_gc_move_in_progress(bool in_progress);
285 void set_concurrent_traversal_in_progress(bool in_progress);
286 void set_has_forwarded_objects(bool cond);
287
288 inline bool is_stable() const;
289 inline bool is_idle() const;
290 inline bool is_concurrent_mark_in_progress() const;
291 inline bool is_update_refs_in_progress() const;
292 inline bool is_evacuation_in_progress() const;
293 inline bool is_degenerated_gc_in_progress() const;
294 inline bool is_full_gc_in_progress() const;
295 inline bool is_full_gc_move_in_progress() const;
296 inline bool is_concurrent_traversal_in_progress() const;
297 inline bool has_forwarded_objects() const;
298 inline bool is_gc_in_progress_mask(uint mask) 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_traversal,
308 _degenerated_outside_cycle,
309 _degenerated_mark,
310 _degenerated_evac,
311 _degenerated_updaterefs,
312 _DEGENERATED_LIMIT
313 };
314
315 static const char* degen_point_to_string(ShenandoahDegenPoint point) {
316 switch (point) {
317 case _degenerated_unset:
318 return "<UNSET>";
319 case _degenerated_traversal:
320 return "Traversal";
321 case _degenerated_outside_cycle:
322 return "Outside of Cycle";
323 case _degenerated_mark:
324 return "Mark";
325 case _degenerated_evac:
326 return "Evacuation";
327 case _degenerated_updaterefs:
328 return "Update Refs";
329 default:
330 ShouldNotReachHere();
331 return "ERROR";
332 }
333 };
334
335 private:
336 enum CancelState {
337 // Normal state. GC has not been cancelled and is open for cancellation.
338 // Worker threads can suspend for safepoint.
339 CANCELLABLE,
340
341 // GC has been cancelled. Worker threads can not suspend for
342 // safepoint but must finish their work as soon as possible.
343 CANCELLED,
344
345 // GC has not been cancelled and must not be cancelled. At least
346 // one worker thread checks for pending safepoint and may suspend
347 // if a safepoint is pending.
348 NOT_CANCELLED
349 };
350
351 ShenandoahSharedEnumFlag<CancelState> _cancelled_gc;
352 inline bool try_cancel_gc();
353
354 public:
355 static address cancelled_gc_addr();
356
357 inline bool cancelled_gc() const;
358 inline bool check_cancelled_gc_and_yield(bool sts_active = true);
359
360 inline void clear_cancelled_gc();
361
362 void cancel_gc(GCCause::Cause cause);
363
364 // ---------- GC operations entry points
365 //
366 public:
367 // Entry points to STW GC operations, these cause a related safepoint, that then
368 // call the entry method below
369 void vmop_entry_init_mark();
370 void vmop_entry_final_mark();
371 void vmop_entry_final_evac();
372 void vmop_entry_init_updaterefs();
373 void vmop_entry_final_updaterefs();
374 void vmop_entry_init_traversal();
375 void vmop_entry_final_traversal();
376 void vmop_entry_full(GCCause::Cause cause);
377 void vmop_degenerated(ShenandoahDegenPoint point);
378
379 // Entry methods to normally STW GC operations. These set up logging, monitoring
380 // and workers for net VM operation
381 void entry_init_mark();
382 void entry_final_mark();
383 void entry_final_evac();
384 void entry_init_updaterefs();
385 void entry_final_updaterefs();
386 void entry_init_traversal();
387 void entry_final_traversal();
388 void entry_full(GCCause::Cause cause);
389 void entry_degenerated(int point);
390
391 // Entry methods to normally concurrent GC operations. These set up logging, monitoring
392 // for concurrent operation.
393 void entry_reset();
394 void entry_mark();
395 void entry_preclean();
396 void entry_cleanup();
397 void entry_evac();
398 void entry_updaterefs();
399 void entry_traversal();
400 void entry_uncommit(double shrink_before);
401
402 private:
403 // Actual work for the phases
404 void op_init_mark();
405 void op_final_mark();
406 void op_final_evac();
407 void op_init_updaterefs();
408 void op_final_updaterefs();
409 void op_init_traversal();
410 void op_final_traversal();
411 void op_full(GCCause::Cause cause);
412 void op_degenerated(ShenandoahDegenPoint point);
413 void op_degenerated_fail();
414 void op_degenerated_futile();
415
416 void op_reset();
417 void op_mark();
418 void op_preclean();
419 void op_cleanup();
420 void op_conc_evac();
421 void op_stw_evac();
422 void op_updaterefs();
423 void op_traversal();
424 void op_uncommit(double shrink_before);
425
426 // Messages for GC trace events, they have to be immortal for
427 // passing around the logging/tracing systems
428 const char* init_mark_event_message() const;
429 const char* final_mark_event_message() const;
430 const char* conc_mark_event_message() const;
431 const char* init_traversal_event_message() const;
432 const char* final_traversal_event_message() const;
433 const char* conc_traversal_event_message() const;
434 const char* degen_event_message(ShenandoahDegenPoint point) const;
435
436 // ---------- GC subsystems
437 //
438 private:
439 ShenandoahControlThread* _control_thread;
440 ShenandoahCollectorPolicy* _shenandoah_policy;
441 ShenandoahMode* _gc_mode;
442 ShenandoahHeuristics* _heuristics;
443 ShenandoahFreeSet* _free_set;
444 ShenandoahConcurrentMark* _scm;
445 ShenandoahTraversalGC* _traversal_gc;
446 ShenandoahMarkCompact* _full_gc;
447 ShenandoahPacer* _pacer;
448 ShenandoahVerifier* _verifier;
449
450 ShenandoahAllocTracker* _alloc_tracker;
451 ShenandoahPhaseTimings* _phase_timings;
452
453 ShenandoahControlThread* control_thread() { return _control_thread; }
454 ShenandoahMarkCompact* full_gc() { return _full_gc; }
455
456 public:
457 ShenandoahCollectorPolicy* shenandoah_policy() const { return _shenandoah_policy; }
458 ShenandoahHeuristics* heuristics() const { return _heuristics; }
459 ShenandoahFreeSet* free_set() const { return _free_set; }
460 ShenandoahConcurrentMark* concurrent_mark() { return _scm; }
461 ShenandoahTraversalGC* traversal_gc() const { return _traversal_gc; }
462 bool is_traversal_mode() const { return _traversal_gc != NULL; }
463 ShenandoahPacer* pacer() const { return _pacer; }
464
465 ShenandoahPhaseTimings* phase_timings() const { return _phase_timings; }
466 ShenandoahAllocTracker* alloc_tracker() const { return _alloc_tracker; }
467
468 ShenandoahVerifier* verifier();
469
470 // ---------- VM subsystem bindings
471 //
472 private:
473 ShenandoahMonitoringSupport* _monitoring_support;
474 MemoryPool* _memory_pool;
475 GCMemoryManager _stw_memory_manager;
476 GCMemoryManager _cycle_memory_manager;
477 ConcurrentGCTimer* _gc_timer;
478 SoftRefPolicy _soft_ref_policy;
479
480 public:
481 ShenandoahMonitoringSupport* monitoring_support() { return _monitoring_support; }
482 GCMemoryManager* cycle_memory_manager() { return &_cycle_memory_manager; }
483 GCMemoryManager* stw_memory_manager() { return &_stw_memory_manager; }
484 SoftRefPolicy* soft_ref_policy() { return &_soft_ref_policy; }
485
486 GrowableArray<GCMemoryManager*> memory_managers();
487 GrowableArray<MemoryPool*> memory_pools();
488 MemoryUsage memory_usage();
489 GCTracer* tracer();
490 GCTimer* gc_timer() const;
491 CollectorPolicy* collector_policy() const;
492
493 // ---------- Reference processing
494 //
495 private:
496 AlwaysTrueClosure _subject_to_discovery;
497 ReferenceProcessor* _ref_processor;
498 ShenandoahSharedFlag _process_references;
499
500 void ref_processing_init();
501
502 public:
503 ReferenceProcessor* ref_processor() { return _ref_processor; }
504 void set_process_references(bool pr);
505 bool process_references() const;
506
507 // ---------- Class Unloading
508 //
509 private:
510 ShenandoahSharedFlag _unload_classes;
511
512 public:
513 void set_unload_classes(bool uc);
514 bool unload_classes() const;
515
516 // Delete entries for dead interned string and clean up unreferenced symbols
517 // in symbol table, possibly in parallel.
518 void unload_classes_and_cleanup_tables(bool full_gc);
519
520 // ---------- Generic interface hooks
521 // Minor things that super-interface expects us to implement to play nice with
522 // the rest of runtime. Some of the things here are not required to be implemented,
523 // and can be stubbed out.
524 //
525 public:
526 AdaptiveSizePolicy* size_policy() shenandoah_not_implemented_return(NULL);
527 bool is_maximal_no_gc() const shenandoah_not_implemented_return(false);
528
529 bool is_in(const void* p) const;
530
531 // All objects can potentially move
532 bool is_scavengable(oop obj) { return true; };
533
534 void collect(GCCause::Cause cause);
535 void do_full_collection(bool clear_all_soft_refs);
536
537 // Used for parsing heap during error printing
538 HeapWord* block_start(const void* addr) const;
539 size_t block_size(const HeapWord* addr) const;
540 bool block_is_obj(const HeapWord* addr) const;
541
542 // Used for native heap walkers: heap dumpers, mostly
543 void object_iterate(ObjectClosure* cl);
544 void safe_object_iterate(ObjectClosure* cl);
545
546 // Used by RMI
547 jlong millis_since_last_gc();
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
561 // ---------- Pinning hooks
562 //
563 public:
564 // Shenandoah supports per-object (per-region) pinning
565 bool supports_object_pinning() const { return true; }
566
567 oop pin_object(JavaThread* thread, oop obj);
568 void unpin_object(JavaThread* thread, oop obj);
569
570 void sync_pinned_region_status();
571 void assert_pinned_region_status() NOT_DEBUG_RETURN;
572
573 // ---------- Allocation support
574 //
575 private:
576 HeapWord* allocate_memory_under_lock(ShenandoahAllocRequest& request, bool& in_new_region);
577 inline HeapWord* allocate_from_gclab(Thread* thread, size_t size);
578 HeapWord* allocate_from_gclab_slow(Thread* thread, size_t size);
579 HeapWord* allocate_new_gclab(size_t min_size, size_t word_size, size_t* actual_size);
580 void retire_and_reset_gclabs();
581
582 public:
583 HeapWord* allocate_memory(ShenandoahAllocRequest& request);
584 HeapWord* mem_allocate(size_t size, bool* what);
585 MetaWord* satisfy_failed_metadata_allocation(ClassLoaderData* loader_data,
586 size_t size,
587 Metaspace::MetadataType mdtype);
588
589 void notify_mutator_alloc_words(size_t words, bool waste);
590
591 // Shenandoah supports TLAB allocation
592 bool supports_tlab_allocation() const { return true; }
593
594 HeapWord* allocate_new_tlab(size_t min_size, size_t requested_size, size_t* actual_size);
595 size_t tlab_capacity(Thread *thr) const;
596 size_t unsafe_max_tlab_alloc(Thread *thread) const;
597 size_t max_tlab_size() const;
598 size_t tlab_used(Thread* ignored) const;
599
600 void accumulate_statistics_tlabs();
601 void resize_tlabs();
602
603 void ensure_parsability(bool retire_tlabs);
604 void make_parsable(bool retire_tlabs);
605
606 // ---------- Marking support
607 //
608 private:
609 ShenandoahMarkingContext* _marking_context;
610 MemRegion _bitmap_region;
611 MemRegion _aux_bitmap_region;
612 MarkBitMap _verification_bit_map;
613 MarkBitMap _aux_bit_map;
614
615 size_t _bitmap_size;
616 size_t _bitmap_regions_per_slice;
617 size_t _bitmap_bytes_per_slice;
618
619 bool _bitmap_region_special;
620 bool _aux_bitmap_region_special;
621
622 // Used for buffering per-region liveness data.
623 // Needed since ShenandoahHeapRegion uses atomics to update liveness.
624 //
625 // The array has max-workers elements, each of which is an array of
626 // jushort * max_regions. The choice of jushort is not accidental:
627 // there is a tradeoff between static/dynamic footprint that translates
628 // into cache pressure (which is already high during marking), and
629 // too many atomic updates. size_t/jint is too large, jbyte is too small.
630 jushort** _liveness_cache;
631
632 public:
633 inline ShenandoahMarkingContext* complete_marking_context() const;
634 inline ShenandoahMarkingContext* marking_context() const;
635 inline void mark_complete_marking_context();
636 inline void mark_incomplete_marking_context();
637
638 template<class T>
639 inline void marked_object_iterate(ShenandoahHeapRegion* region, T* cl);
640
641 template<class T>
642 inline void marked_object_iterate(ShenandoahHeapRegion* region, T* cl, HeapWord* limit);
643
644 template<class T>
645 inline void marked_object_oop_iterate(ShenandoahHeapRegion* region, T* cl, HeapWord* limit);
646
647 void reset_mark_bitmap();
648
649 // SATB barriers hooks
650 inline bool requires_marking(const void* entry) const;
651 void force_satb_flush_all_threads();
652
653 // Support for bitmap uncommits
654 bool commit_bitmap_slice(ShenandoahHeapRegion *r);
655 bool uncommit_bitmap_slice(ShenandoahHeapRegion *r);
656 bool is_bitmap_slice_committed(ShenandoahHeapRegion* r, bool skip_self = false);
657
658 // Liveness caching support
659 jushort* get_liveness_cache(uint worker_id);
660 void flush_liveness_cache(uint worker_id);
661
662 // ---------- Evacuation support
663 //
664 private:
665 ShenandoahCollectionSet* _collection_set;
666 ShenandoahEvacOOMHandler _oom_evac_handler;
667
668 void evacuate_and_update_roots();
669
670 public:
671 static address in_cset_fast_test_addr();
672
673 ShenandoahCollectionSet* collection_set() const { return _collection_set; }
674
675 template <class T>
676 inline bool in_collection_set(T obj) const;
677
678 // Avoid accidentally calling the method above with ShenandoahHeapRegion*, which would be *wrong*.
679 inline bool in_collection_set(ShenandoahHeapRegion* r) shenandoah_not_implemented_return(false);
680
681 // Evacuates object src. Returns the evacuated object, either evacuated
682 // by this thread, or by some other thread.
683 inline oop evacuate_object(oop src, Thread* thread);
684
685 // Call before/after evacuation.
686 void enter_evacuation();
687 void leave_evacuation();
688
689 // ---------- Helper functions
690 //
691 public:
692 template <class T>
693 inline oop evac_update_with_forwarded(T* p);
694
695 template <class T>
696 inline oop maybe_update_with_forwarded(T* p);
697
698 template <class T>
699 inline oop maybe_update_with_forwarded_not_null(T* p, oop obj);
700
701 template <class T>
702 inline oop update_with_forwarded_not_null(T* p, oop obj);
703
704 static inline oop cas_oop(oop n, narrowOop* addr, oop c);
705 static inline oop cas_oop(oop n, oop* addr, oop c);
706 static inline oop cas_oop(oop n, narrowOop* addr, narrowOop c);
707
708 void trash_humongous_region_at(ShenandoahHeapRegion *r);
709
710 void deduplicate_string(oop str);
711
712 void stop_concurrent_marking();
713
714 private:
715 void trash_cset_regions();
716 void update_heap_references(bool concurrent);
717
718 // ---------- Testing helpers functions
719 //
720 private:
721 ShenandoahSharedFlag _inject_alloc_failure;
722
723 void try_inject_alloc_failure();
724 bool should_inject_alloc_failure();
725 };
726
727 #endif // SHARE_VM_GC_SHENANDOAH_SHENANDOAHHEAP_HPP