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/shenandoahHeapLock.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 ShenandoahPhaseTimings;
47 class ShenandoahHeap;
48 class ShenandoahHeapRegion;
49 class ShenandoahHeapRegionClosure;
50 class ShenandoahCollectionSet;
51 class ShenandoahFreeSet;
52 class ShenandoahConcurrentMark;
53 class ShenandoahMarkCompact;
54 class ShenandoahMonitoringSupport;
55 class ShenandoahPacer;
56 class ShenandoahTraversalGC;
57 class ShenandoahVerifier;
58 class ShenandoahWorkGang;
59 class VMStructs;
60
61 class ShenandoahRegionIterator : public StackObj {
62 private:
63 ShenandoahHeap* _heap;
64
65 DEFINE_PAD_MINUS_SIZE(0, DEFAULT_CACHE_LINE_SIZE, sizeof(volatile size_t));
66 volatile size_t _index;
67 DEFINE_PAD_MINUS_SIZE(1, DEFAULT_CACHE_LINE_SIZE, 0);
68
69 // No implicit copying: iterators should be passed by reference to capture the state
70 ShenandoahRegionIterator(const ShenandoahRegionIterator& that);
71 ShenandoahRegionIterator& operator=(const ShenandoahRegionIterator& o);
72
73 public:
74 ShenandoahRegionIterator();
75 ShenandoahRegionIterator(ShenandoahHeap* heap);
76
77 // Reset iterator to default state
78 void reset();
79
80 // Returns next region, or NULL if there are no more regions.
81 // This is multi-thread-safe.
82 inline ShenandoahHeapRegion* next();
83
84 // This is *not* MT safe. However, in the absence of multithreaded access, it
85 // can be used to determine if there is more work to do.
86 bool has_next() const;
87 };
88
89 class ShenandoahHeapRegionClosure : public StackObj {
90 public:
91 virtual void heap_region_do(ShenandoahHeapRegion* r) = 0;
92 virtual bool is_thread_safe() { return false; }
93 };
94
95 #ifdef ASSERT
96 class ShenandoahAssertToSpaceClosure : public OopClosure {
97 private:
98 template <class T>
99 void do_oop_work(T* p);
100 public:
101 void do_oop(narrowOop* p);
102 void do_oop(oop* p);
103 };
104 #endif
105
106
107 // Shenandoah GC is low-pause concurrent GC that uses Brooks forwarding pointers
108 // to encode forwarding data. See BrooksPointer for details on forwarding data encoding.
109 // See ShenandoahControlThread for GC cycle structure.
110 //
111 class ShenandoahHeap : public CollectedHeap {
112 friend class ShenandoahAsserts;
113 friend class VMStructs;
114 friend class ShenandoahGCSession;
115 friend class ShenandoahGCStateResetter;
116
117 // ---------- Locks that guard important data structures in Heap
118 //
119 private:
120 ShenandoahHeapLock _lock;
121
122 public:
123 ShenandoahHeapLock* lock() {
124 return &_lock;
125 }
126
127 void assert_heaplock_owned_by_current_thread() NOT_DEBUG_RETURN;
128 void assert_heaplock_not_owned_by_current_thread() NOT_DEBUG_RETURN;
129 void assert_heaplock_or_safepoint() NOT_DEBUG_RETURN;
130
131 // ---------- Initialization, termination, identification, printing routines
132 //
133 public:
134 static ShenandoahHeap* heap();
135 static ShenandoahHeap* heap_no_check();
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_gc_threads_on(outputStream* st) const;
151 void print_heap_regions_on(outputStream* st) const;
152
153 void stop();
154
155 void prepare_for_verify();
156 void verify(VerifyOption vo);
157
158 // ---------- Heap counters and metrics
159 //
160 private:
161 size_t _initial_size;
162 size_t _minimum_size;
163 DEFINE_PAD_MINUS_SIZE(0, DEFAULT_CACHE_LINE_SIZE, sizeof(volatile size_t));
164 volatile size_t _used;
165 volatile size_t _committed;
166 volatile size_t _bytes_allocated_since_gc_start;
167 DEFINE_PAD_MINUS_SIZE(1, DEFAULT_CACHE_LINE_SIZE, 0);
168
169 public:
170 void increase_used(size_t bytes);
171 void decrease_used(size_t bytes);
172 void set_used(size_t bytes);
173
174 void increase_committed(size_t bytes);
175 void decrease_committed(size_t bytes);
176 void increase_allocated(size_t bytes);
177
178 size_t bytes_allocated_since_gc_start();
179 void reset_bytes_allocated_since_gc_start();
180
181 size_t min_capacity() const;
182 size_t max_capacity() const;
183 size_t initial_capacity() const;
184 size_t capacity() const;
185 size_t used() const;
186 size_t committed() const;
187
188 // ---------- Workers handling
189 //
190 private:
191 uint _max_workers;
192 ShenandoahWorkGang* _workers;
193 ShenandoahWorkGang* _safepoint_workers;
194
195 public:
196 uint max_workers();
197 void assert_gc_workers(uint nworker) NOT_DEBUG_RETURN;
198
199 WorkGang* workers() const;
200 WorkGang* get_safepoint_workers();
201
202 void gc_threads_do(ThreadClosure* tcl) const;
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 inline size_t num_regions() const { return _num_regions; }
215 inline bool is_heap_region_special() { return _heap_region_special; }
216
217 inline ShenandoahHeapRegion* const heap_region_containing(const void* addr) const;
218 inline size_t heap_region_index_containing(const void* addr) const;
219
220 inline ShenandoahHeapRegion* const get_region(size_t region_idx) const;
221
222 void heap_region_iterate(ShenandoahHeapRegionClosure* blk) const;
223 void parallel_heap_region_iterate(ShenandoahHeapRegionClosure* blk) const;
224
225 // ---------- GC state machinery
226 //
227 // GC state describes the important parts of collector state, that may be
228 // used to make barrier selection decisions in the native and generated code.
229 // Multiple bits can be set at once.
230 //
231 // Important invariant: when GC state is zero, the heap is stable, and no barriers
232 // are required.
233 //
234 public:
235 enum GCStateBitPos {
236 // Heap has forwarded objects: needs LRB barriers.
237 HAS_FORWARDED_BITPOS = 0,
238
239 // Heap is under marking: needs SATB barriers.
240 MARKING_BITPOS = 1,
241
242 // Heap is under evacuation: needs LRB barriers. (Set together with HAS_FORWARDED)
243 EVACUATION_BITPOS = 2,
244
245 // Heap is under updating: needs no additional barriers.
246 UPDATEREFS_BITPOS = 3,
247
248 // Heap is under traversal collection
249 TRAVERSAL_BITPOS = 4
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 TRAVERSAL = 1 << TRAVERSAL_BITPOS
259 };
260
261 private:
262 ShenandoahSharedBitmap _gc_state;
263 ShenandoahSharedFlag _degenerated_gc_in_progress;
264 ShenandoahSharedFlag _full_gc_in_progress;
265 ShenandoahSharedFlag _full_gc_move_in_progress;
266 ShenandoahSharedFlag _progress_last_gc;
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_concurrent_traversal_in_progress(bool in_progress);
282 void set_has_forwarded_objects(bool cond);
283
284 inline bool is_stable() const;
285 inline bool is_idle() const;
286 inline bool is_concurrent_mark_in_progress() const;
287 inline bool is_update_refs_in_progress() const;
288 inline bool is_evacuation_in_progress() const;
289 inline bool is_degenerated_gc_in_progress() const;
290 inline bool is_full_gc_in_progress() const;
291 inline bool is_full_gc_move_in_progress() const;
292 inline bool is_concurrent_traversal_in_progress() const;
293 inline bool has_forwarded_objects() const;
294 inline bool is_gc_in_progress_mask(uint mask) const;
295
296 // ---------- GC cancellation and degeneration machinery
297 //
298 // Cancelled GC flag is used to notify concurrent phases that they should terminate.
299 //
300 public:
301 enum ShenandoahDegenPoint {
302 _degenerated_unset,
303 _degenerated_traversal,
304 _degenerated_outside_cycle,
305 _degenerated_mark,
306 _degenerated_evac,
307 _degenerated_updaterefs,
308 _DEGENERATED_LIMIT
309 };
310
311 static const char* degen_point_to_string(ShenandoahDegenPoint point) {
312 switch (point) {
313 case _degenerated_unset:
314 return "<UNSET>";
315 case _degenerated_traversal:
316 return "Traversal";
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_final_evac();
368 void vmop_entry_init_updaterefs();
369 void vmop_entry_final_updaterefs();
370 void vmop_entry_init_traversal();
371 void vmop_entry_final_traversal();
372 void vmop_entry_full(GCCause::Cause cause);
373 void vmop_degenerated(ShenandoahDegenPoint point);
374
375 // Entry methods to normally STW GC operations. These set up logging, monitoring
376 // and workers for net VM operation
377 void entry_init_mark();
378 void entry_final_mark();
379 void entry_final_evac();
380 void entry_init_updaterefs();
381 void entry_final_updaterefs();
382 void entry_init_traversal();
383 void entry_final_traversal();
384 void entry_full(GCCause::Cause cause);
385 void entry_degenerated(int point);
386
387 // Entry methods to normally concurrent GC operations. These set up logging, monitoring
388 // for concurrent operation.
389 void entry_reset();
390 void entry_mark();
391 void entry_preclean();
392 void entry_cleanup();
393 void entry_evac();
394 void entry_updaterefs();
395 void entry_traversal();
396 void entry_uncommit(double shrink_before);
397
398 private:
399 // Actual work for the phases
400 void op_init_mark();
401 void op_final_mark();
402 void op_final_evac();
403 void op_init_updaterefs();
404 void op_final_updaterefs();
405 void op_init_traversal();
406 void op_final_traversal();
407 void op_full(GCCause::Cause cause);
408 void op_degenerated(ShenandoahDegenPoint point);
409 void op_degenerated_fail();
410 void op_degenerated_futile();
411
412 void op_reset();
413 void op_mark();
414 void op_preclean();
415 void op_cleanup();
416 void op_conc_evac();
417 void op_stw_evac();
418 void op_updaterefs();
419 void op_traversal();
420 void op_uncommit(double shrink_before);
421
422 // Messages for GC trace events, they have to be immortal for
423 // passing around the logging/tracing systems
424 const char* init_mark_event_message() const;
425 const char* final_mark_event_message() const;
426 const char* conc_mark_event_message() const;
427 const char* degen_event_message(ShenandoahDegenPoint point) const;
428
429 // ---------- GC subsystems
430 //
431 private:
432 ShenandoahControlThread* _control_thread;
433 ShenandoahCollectorPolicy* _shenandoah_policy;
434 ShenandoahHeuristics* _heuristics;
435 ShenandoahFreeSet* _free_set;
436 ShenandoahConcurrentMark* _scm;
437 ShenandoahTraversalGC* _traversal_gc;
438 ShenandoahMarkCompact* _full_gc;
439 ShenandoahPacer* _pacer;
440 ShenandoahVerifier* _verifier;
441
442 ShenandoahAllocTracker* _alloc_tracker;
443 ShenandoahPhaseTimings* _phase_timings;
444
445 ShenandoahControlThread* control_thread() { return _control_thread; }
446 ShenandoahMarkCompact* full_gc() { return _full_gc; }
447
448 public:
449 ShenandoahCollectorPolicy* shenandoah_policy() const { return _shenandoah_policy; }
450 ShenandoahHeuristics* heuristics() const { return _heuristics; }
451 ShenandoahFreeSet* free_set() const { return _free_set; }
452 ShenandoahConcurrentMark* concurrent_mark() { return _scm; }
453 ShenandoahTraversalGC* traversal_gc() { return _traversal_gc; }
454 ShenandoahPacer* pacer() const { return _pacer; }
455
456 ShenandoahPhaseTimings* phase_timings() const { return _phase_timings; }
457 ShenandoahAllocTracker* alloc_tracker() const { return _alloc_tracker; }
458
459 ShenandoahVerifier* verifier();
460
461 // ---------- VM subsystem bindings
462 //
463 private:
464 ShenandoahMonitoringSupport* _monitoring_support;
465 MemoryPool* _memory_pool;
466 GCMemoryManager _stw_memory_manager;
467 GCMemoryManager _cycle_memory_manager;
468 ConcurrentGCTimer* _gc_timer;
469 SoftRefPolicy _soft_ref_policy;
470
471 // For exporting to SA
472 int _log_min_obj_alignment_in_bytes;
473 public:
474 ShenandoahMonitoringSupport* monitoring_support() { return _monitoring_support; }
475 GCMemoryManager* cycle_memory_manager() { return &_cycle_memory_manager; }
476 GCMemoryManager* stw_memory_manager() { return &_stw_memory_manager; }
477 SoftRefPolicy* soft_ref_policy() { return &_soft_ref_policy; }
478
479 GrowableArray<GCMemoryManager*> memory_managers();
480 GrowableArray<MemoryPool*> memory_pools();
481 MemoryUsage memory_usage();
482 GCTracer* tracer();
483 GCTimer* gc_timer() const;
484
485 // ---------- Reference processing
486 //
487 private:
488 AlwaysTrueClosure _subject_to_discovery;
489 ReferenceProcessor* _ref_processor;
490 ShenandoahSharedFlag _process_references;
491
492 void ref_processing_init();
493
494 public:
495 ReferenceProcessor* ref_processor() { return _ref_processor; }
496 void set_process_references(bool pr);
497 bool process_references() const;
498
499 // ---------- Class Unloading
500 //
501 private:
502 ShenandoahSharedFlag _unload_classes;
503
504 public:
505 void set_unload_classes(bool uc);
506 bool unload_classes() const;
507
508 // Delete entries for dead interned string and clean up unreferenced symbols
509 // in symbol table, possibly in parallel.
510 void unload_classes_and_cleanup_tables(bool full_gc);
511
512 // ---------- Generic interface hooks
513 // Minor things that super-interface expects us to implement to play nice with
514 // the rest of runtime. Some of the things here are not required to be implemented,
515 // and can be stubbed out.
516 //
517 public:
518 AdaptiveSizePolicy* size_policy() shenandoah_not_implemented_return(NULL);
519 bool is_maximal_no_gc() const shenandoah_not_implemented_return(false);
520
521 bool is_in(const void* p) const;
522
523 size_t obj_size(oop obj) const;
524 virtual ptrdiff_t cell_header_size() const;
525
526 void collect(GCCause::Cause cause);
527 void do_full_collection(bool clear_all_soft_refs);
528
529 // Used for parsing heap during error printing
530 HeapWord* block_start(const void* addr) const;
531 bool block_is_obj(const HeapWord* addr) const;
532
533 // Used for native heap walkers: heap dumpers, mostly
534 void object_iterate(ObjectClosure* cl);
535 void safe_object_iterate(ObjectClosure* cl);
536
537 // Used by RMI
538 jlong millis_since_last_gc();
539
540 // ---------- Safepoint interface hooks
541 //
542 public:
543 void safepoint_synchronize_begin();
544 void safepoint_synchronize_end();
545
546 // ---------- Code roots handling hooks
547 //
548 public:
549 void register_nmethod(nmethod* nm);
550 void unregister_nmethod(nmethod* nm);
551 void flush_nmethod(nmethod* nm) {}
552 void verify_nmethod(nmethod* nm) {}
553
554 // ---------- Pinning hooks
555 //
556 public:
557 // Shenandoah supports per-object (per-region) pinning
558 bool supports_object_pinning() const { return true; }
559
560 oop pin_object(JavaThread* thread, oop obj);
561 void unpin_object(JavaThread* thread, oop obj);
562
563 // ---------- Allocation support
564 //
565 private:
566 HeapWord* allocate_memory_under_lock(ShenandoahAllocRequest& request, bool& in_new_region);
567 inline HeapWord* allocate_from_gclab(Thread* thread, size_t size);
568 HeapWord* allocate_from_gclab_slow(Thread* thread, size_t size);
569 HeapWord* allocate_new_gclab(size_t min_size, size_t word_size, size_t* actual_size);
570 void retire_and_reset_gclabs();
571
572 public:
573 HeapWord* allocate_memory(ShenandoahAllocRequest& request);
574 HeapWord* mem_allocate(size_t size, bool* what);
575 MetaWord* satisfy_failed_metadata_allocation(ClassLoaderData* loader_data,
576 size_t size,
577 Metaspace::MetadataType mdtype);
578
579 oop obj_allocate(Klass* klass, int size, TRAPS);
580 oop array_allocate(Klass* klass, int size, int length, bool do_zero, TRAPS);
581 oop class_allocate(Klass* klass, int size, TRAPS);
582
583 void notify_mutator_alloc_words(size_t words, bool waste);
584
585 // Shenandoah supports TLAB allocation
586 bool supports_tlab_allocation() const { return true; }
587
588 HeapWord* allocate_new_tlab(size_t min_size, size_t requested_size, size_t* actual_size);
589 size_t tlab_capacity(Thread *thr) const;
590 size_t unsafe_max_tlab_alloc(Thread *thread) const;
591 size_t max_tlab_size() const;
592 size_t tlab_used(Thread* ignored) const;
593
594 HeapWord* tlab_post_allocation_setup(HeapWord* obj);
595 void fill_with_dummy_object(HeapWord* start, HeapWord* end, bool zap);
596 size_t min_dummy_object_size() const;
597
598 void resize_tlabs();
599
600 void ensure_parsability(bool retire_tlabs);
601 void make_parsable(bool retire_tlabs);
602
603 // ---------- Marking support
604 //
605 private:
606 ShenandoahMarkingContext* _marking_context;
607 MemRegion _bitmap_region;
608 MemRegion _aux_bitmap_region;
609 MarkBitMap _verification_bit_map;
610 MarkBitMap _aux_bit_map;
611
612 size_t _bitmap_size;
613 size_t _bitmap_regions_per_slice;
614 size_t _bitmap_bytes_per_slice;
615
616 bool _bitmap_region_special;
617 bool _aux_bitmap_region_special;
618
619 // Used for buffering per-region liveness data.
620 // Needed since ShenandoahHeapRegion uses atomics to update liveness.
621 //
622 // The array has max-workers elements, each of which is an array of
623 // jushort * max_regions. The choice of jushort is not accidental:
624 // there is a tradeoff between static/dynamic footprint that translates
625 // into cache pressure (which is already high during marking), and
626 // too many atomic updates. size_t/jint is too large, jbyte is too small.
627 jushort** _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 template<bool RESOLVE>
648 inline bool requires_marking(const void* entry) const;
649 void force_satb_flush_all_threads();
650
651 // Support for bitmap uncommits
652 bool commit_bitmap_slice(ShenandoahHeapRegion *r);
653 bool uncommit_bitmap_slice(ShenandoahHeapRegion *r);
654 bool is_bitmap_slice_committed(ShenandoahHeapRegion* r, bool skip_self = false);
655
656 // Liveness caching support
657 jushort* get_liveness_cache(uint worker_id);
658 void flush_liveness_cache(uint worker_id);
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 template <class T>
674 inline bool in_collection_set(T obj) const;
675
676 // Avoid accidentally calling the method above with ShenandoahHeapRegion*, which would be *wrong*.
677 inline bool in_collection_set(ShenandoahHeapRegion* r) shenandoah_not_implemented_return(false);
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 void enter_evacuation();
685 void leave_evacuation();
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 inline oop atomic_compare_exchange_oop(oop n, narrowOop* addr, oop c);
703 inline oop atomic_compare_exchange_oop(oop n, oop* addr, oop c);
704
705 void trash_humongous_region_at(ShenandoahHeapRegion *r);
706
707 void deduplicate_string(oop str);
708
709 void stop_concurrent_marking();
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