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/shenandoahSharedVariables.hpp"
36 #include "gc/shenandoah/shenandoahUnload.hpp"
37 #include "services/memoryManager.hpp"
38 #include "utilities/globalDefinitions.hpp"
39
40 class ConcurrentGCTimer;
41 class ReferenceProcessor;
42 class ShenandoahAllocTracker;
43 class ShenandoahCollectorPolicy;
44 class ShenandoahControlThread;
45 class ShenandoahGCSession;
46 class ShenandoahGCStateResetter;
47 class ShenandoahHeuristics;
48 class ShenandoahMarkingContext;
49 class ShenandoahMarkCompact;
50 class ShenandoahMode;
51 class ShenandoahPhaseTimings;
52 class ShenandoahHeap;
53 class ShenandoahHeapRegion;
54 class ShenandoahHeapRegionClosure;
55 class ShenandoahCollectionSet;
56 class ShenandoahFreeSet;
57 class ShenandoahConcurrentMark;
58 class ShenandoahMarkCompact;
59 class ShenandoahMonitoringSupport;
60 class ShenandoahPacer;
61 class ShenandoahTraversalGC;
62 class ShenandoahVerifier;
63 class ShenandoahWorkGang;
64 class VMStructs;
65
66 class ShenandoahRegionIterator : public StackObj {
67 private:
68 ShenandoahHeap* _heap;
69
70 DEFINE_PAD_MINUS_SIZE(0, DEFAULT_CACHE_LINE_SIZE, sizeof(volatile size_t));
71 volatile size_t _index;
72 DEFINE_PAD_MINUS_SIZE(1, DEFAULT_CACHE_LINE_SIZE, 0);
73
74 // No implicit copying: iterators should be passed by reference to capture the state
75 NONCOPYABLE(ShenandoahRegionIterator);
76
77 public:
78 ShenandoahRegionIterator();
79 ShenandoahRegionIterator(ShenandoahHeap* heap);
80
81 // Reset iterator to default state
82 void reset();
83
84 // Returns next region, or NULL if there are no more regions.
85 // This is multi-thread-safe.
86 inline ShenandoahHeapRegion* next();
87
88 // This is *not* MT safe. However, in the absence of multithreaded access, it
89 // can be used to determine if there is more work to do.
90 bool has_next() const;
91 };
92
93 class ShenandoahHeapRegionClosure : public StackObj {
94 public:
95 virtual void heap_region_do(ShenandoahHeapRegion* r) = 0;
96 virtual bool is_thread_safe() { return false; }
97 };
98
99 #ifdef ASSERT
100 class ShenandoahAssertToSpaceClosure : public OopClosure {
101 private:
102 template <class T>
103 void do_oop_work(T* p);
104 public:
105 void do_oop(narrowOop* p);
106 void do_oop(oop* p);
107 };
108 #endif
109
110 typedef ShenandoahLock ShenandoahHeapLock;
111 typedef ShenandoahLocker ShenandoahHeapLocker;
112
113 // Shenandoah GC is low-pause concurrent GC that uses Brooks forwarding pointers
114 // to encode forwarding data. See BrooksPointer for details on forwarding data encoding.
115 // See ShenandoahControlThread for GC cycle structure.
116 //
117 class ShenandoahHeap : public CollectedHeap {
118 friend class ShenandoahAsserts;
119 friend class VMStructs;
120 friend class ShenandoahGCSession;
121 friend class ShenandoahGCStateResetter;
122
123 // ---------- Locks that guard important data structures in Heap
124 //
125 private:
126 ShenandoahHeapLock _lock;
127
128 public:
129 ShenandoahHeapLock* lock() {
130 return &_lock;
131 }
132
133 void assert_heaplock_owned_by_current_thread() NOT_DEBUG_RETURN;
134 void assert_heaplock_not_owned_by_current_thread() NOT_DEBUG_RETURN;
135 void assert_heaplock_or_safepoint() NOT_DEBUG_RETURN;
136
137 // ---------- Initialization, termination, identification, printing routines
138 //
139 public:
140 static ShenandoahHeap* heap();
141 static ShenandoahHeap* heap_no_check();
142
143 const char* name() const { return "Shenandoah"; }
144 ShenandoahHeap::Name kind() const { return CollectedHeap::Shenandoah; }
145
146 ShenandoahHeap(ShenandoahCollectorPolicy* policy);
147 jint initialize();
148 void post_initialize();
149 void initialize_heuristics();
150
151 void initialize_serviceability();
152
153 void print_on(outputStream* st) const;
154 void print_extended_on(outputStream *st) const;
155 void print_tracing_info() const;
156 void print_gc_threads_on(outputStream* st) const;
157 void print_heap_regions_on(outputStream* st) const;
158
159 void stop();
160
161 void prepare_for_verify();
162 void verify(VerifyOption vo);
163
164 // ---------- Heap counters and metrics
165 //
166 private:
167 size_t _initial_size;
168 size_t _minimum_size;
169 DEFINE_PAD_MINUS_SIZE(0, DEFAULT_CACHE_LINE_SIZE, sizeof(volatile size_t));
170 volatile size_t _used;
171 volatile size_t _committed;
172 volatile size_t _bytes_allocated_since_gc_start;
173 DEFINE_PAD_MINUS_SIZE(1, DEFAULT_CACHE_LINE_SIZE, 0);
174
175 public:
176 void increase_used(size_t bytes);
177 void decrease_used(size_t bytes);
178 void set_used(size_t bytes);
179
180 void increase_committed(size_t bytes);
181 void decrease_committed(size_t bytes);
182 void increase_allocated(size_t bytes);
183
184 size_t bytes_allocated_since_gc_start();
185 void reset_bytes_allocated_since_gc_start();
186
187 size_t min_capacity() const;
188 size_t max_capacity() const;
189 size_t initial_capacity() const;
190 size_t capacity() const;
191 size_t used() const;
192 size_t committed() const;
193
194 // ---------- Workers handling
195 //
196 private:
197 uint _max_workers;
198 ShenandoahWorkGang* _workers;
199 ShenandoahWorkGang* _safepoint_workers;
200
201 public:
202 uint max_workers();
203 void assert_gc_workers(uint nworker) NOT_DEBUG_RETURN;
204
205 WorkGang* workers() const;
206 WorkGang* get_safepoint_workers();
207
208 void gc_threads_do(ThreadClosure* tcl) const;
209
210 // ---------- Heap regions handling machinery
211 //
212 private:
213 MemRegion _heap_region;
214 bool _heap_region_special;
215 size_t _num_regions;
216 ShenandoahHeapRegion** _regions;
217 ShenandoahRegionIterator _update_refs_iterator;
218
219 public:
220
221 inline HeapWord* base() const { return _heap_region.start(); }
222
223 inline size_t num_regions() const { return _num_regions; }
224 inline bool is_heap_region_special() { return _heap_region_special; }
225
226 inline ShenandoahHeapRegion* const heap_region_containing(const void* addr) const;
227 inline size_t heap_region_index_containing(const void* addr) const;
228
229 inline ShenandoahHeapRegion* const get_region(size_t region_idx) const;
230
231 void heap_region_iterate(ShenandoahHeapRegionClosure* blk) const;
232 void parallel_heap_region_iterate(ShenandoahHeapRegionClosure* blk) const;
233
234 // ---------- GC state machinery
235 //
236 // GC state describes the important parts of collector state, that may be
237 // used to make barrier selection decisions in the native and generated code.
238 // Multiple bits can be set at once.
239 //
240 // Important invariant: when GC state is zero, the heap is stable, and no barriers
241 // are required.
242 //
243 public:
244 enum GCStateBitPos {
245 // Heap has forwarded objects: needs LRB barriers.
246 HAS_FORWARDED_BITPOS = 0,
247
248 // Heap is under marking: needs SATB barriers.
249 MARKING_BITPOS = 1,
250
251 // Heap is under evacuation: needs LRB barriers. (Set together with HAS_FORWARDED)
252 EVACUATION_BITPOS = 2,
253
254 // Heap is under updating: needs no additional barriers.
255 UPDATEREFS_BITPOS = 3,
256
257 // Heap is under traversal collection
258 TRAVERSAL_BITPOS = 4
259 };
260
261 enum GCState {
262 STABLE = 0,
263 HAS_FORWARDED = 1 << HAS_FORWARDED_BITPOS,
264 MARKING = 1 << MARKING_BITPOS,
265 EVACUATION = 1 << EVACUATION_BITPOS,
266 UPDATEREFS = 1 << UPDATEREFS_BITPOS,
267 TRAVERSAL = 1 << TRAVERSAL_BITPOS
268 };
269
270 private:
271 ShenandoahSharedBitmap _gc_state;
272 ShenandoahSharedFlag _degenerated_gc_in_progress;
273 ShenandoahSharedFlag _full_gc_in_progress;
274 ShenandoahSharedFlag _full_gc_move_in_progress;
275 ShenandoahSharedFlag _progress_last_gc;
276 ShenandoahSharedFlag _concurrent_root_in_progress;
277
278 void set_gc_state_all_threads(char state);
279 void set_gc_state_mask(uint mask, bool value);
280
281 public:
282 char gc_state() const;
283 static address gc_state_addr();
284
285 void set_concurrent_mark_in_progress(bool in_progress);
286 void set_evacuation_in_progress(bool in_progress);
287 void set_update_refs_in_progress(bool in_progress);
288 void set_degenerated_gc_in_progress(bool in_progress);
289 void set_full_gc_in_progress(bool in_progress);
290 void set_full_gc_move_in_progress(bool in_progress);
291 void set_concurrent_traversal_in_progress(bool in_progress);
292 void set_has_forwarded_objects(bool cond);
293 void set_concurrent_root_in_progress(bool cond);
294
295 inline bool is_stable() const;
296 inline bool is_idle() const;
297 inline bool is_concurrent_mark_in_progress() const;
298 inline bool is_update_refs_in_progress() const;
299 inline bool is_evacuation_in_progress() const;
300 inline bool is_degenerated_gc_in_progress() const;
301 inline bool is_full_gc_in_progress() const;
302 inline bool is_full_gc_move_in_progress() const;
303 inline bool is_concurrent_traversal_in_progress() const;
304 inline bool has_forwarded_objects() const;
305 inline bool is_gc_in_progress_mask(uint mask) const;
306 inline bool is_stw_gc_in_progress() const;
307 inline bool is_concurrent_root_in_progress() const;
308
309 // ---------- GC cancellation and degeneration machinery
310 //
311 // Cancelled GC flag is used to notify concurrent phases that they should terminate.
312 //
313 public:
314 enum ShenandoahDegenPoint {
315 _degenerated_unset,
316 _degenerated_traversal,
317 _degenerated_outside_cycle,
318 _degenerated_mark,
319 _degenerated_evac,
320 _degenerated_updaterefs,
321 _DEGENERATED_LIMIT
322 };
323
324 static const char* degen_point_to_string(ShenandoahDegenPoint point) {
325 switch (point) {
326 case _degenerated_unset:
327 return "<UNSET>";
328 case _degenerated_traversal:
329 return "Traversal";
330 case _degenerated_outside_cycle:
331 return "Outside of Cycle";
332 case _degenerated_mark:
333 return "Mark";
334 case _degenerated_evac:
335 return "Evacuation";
336 case _degenerated_updaterefs:
337 return "Update Refs";
338 default:
339 ShouldNotReachHere();
340 return "ERROR";
341 }
342 };
343
344 private:
345 enum CancelState {
346 // Normal state. GC has not been cancelled and is open for cancellation.
347 // Worker threads can suspend for safepoint.
348 CANCELLABLE,
349
350 // GC has been cancelled. Worker threads can not suspend for
351 // safepoint but must finish their work as soon as possible.
352 CANCELLED,
353
354 // GC has not been cancelled and must not be cancelled. At least
355 // one worker thread checks for pending safepoint and may suspend
356 // if a safepoint is pending.
357 NOT_CANCELLED
358 };
359
360 ShenandoahSharedEnumFlag<CancelState> _cancelled_gc;
361 bool try_cancel_gc();
362
363 public:
364 static address cancelled_gc_addr();
365
366 inline bool cancelled_gc() const;
367 inline bool check_cancelled_gc_and_yield(bool sts_active = true);
368
369 inline void clear_cancelled_gc();
370
371 void cancel_gc(GCCause::Cause cause);
372
373 // ---------- GC operations entry points
374 //
375 public:
376 // Entry points to STW GC operations, these cause a related safepoint, that then
377 // call the entry method below
378 void vmop_entry_init_mark();
379 void vmop_entry_final_mark();
380 void vmop_entry_final_evac();
381 void vmop_entry_init_updaterefs();
382 void vmop_entry_final_updaterefs();
383 void vmop_entry_init_traversal();
384 void vmop_entry_final_traversal();
385 void vmop_entry_full(GCCause::Cause cause);
386 void vmop_degenerated(ShenandoahDegenPoint point);
387
388 // Entry methods to normally STW GC operations. These set up logging, monitoring
389 // and workers for net VM operation
390 void entry_init_mark();
391 void entry_final_mark();
392 void entry_final_evac();
393 void entry_init_updaterefs();
394 void entry_final_updaterefs();
395 void entry_init_traversal();
396 void entry_final_traversal();
397 void entry_full(GCCause::Cause cause);
398 void entry_degenerated(int point);
399
400 // Entry methods to normally concurrent GC operations. These set up logging, monitoring
401 // for concurrent operation.
402 void entry_reset();
403 void entry_mark();
404 void entry_preclean();
405 void entry_roots();
406 void entry_cleanup();
407 void entry_evac();
408 void entry_updaterefs();
409 void entry_traversal();
410 void entry_uncommit(double shrink_before);
411
412 private:
413 // Actual work for the phases
414 void op_init_mark();
415 void op_final_mark();
416 void op_final_evac();
417 void op_init_updaterefs();
418 void op_final_updaterefs();
419 void op_init_traversal();
420 void op_final_traversal();
421 void op_full(GCCause::Cause cause);
422 void op_degenerated(ShenandoahDegenPoint point);
423 void op_degenerated_fail();
424 void op_degenerated_futile();
425
426 void op_reset();
427 void op_mark();
428 void op_preclean();
429 void op_roots();
430 void op_cleanup();
431 void op_conc_evac();
432 void op_stw_evac();
433 void op_updaterefs();
434 void op_traversal();
435 void op_uncommit(double shrink_before);
436
437 // Messages for GC trace events, they have to be immortal for
438 // passing around the logging/tracing systems
439 const char* init_mark_event_message() const;
440 const char* final_mark_event_message() const;
441 const char* conc_mark_event_message() const;
442 const char* init_traversal_event_message() const;
443 const char* final_traversal_event_message() const;
444 const char* conc_traversal_event_message() const;
445 const char* degen_event_message(ShenandoahDegenPoint point) const;
446
447 // ---------- GC subsystems
448 //
449 private:
450 ShenandoahControlThread* _control_thread;
451 ShenandoahCollectorPolicy* _shenandoah_policy;
452 ShenandoahMode* _gc_mode;
453 ShenandoahHeuristics* _heuristics;
454 ShenandoahFreeSet* _free_set;
455 ShenandoahConcurrentMark* _scm;
456 ShenandoahTraversalGC* _traversal_gc;
457 ShenandoahMarkCompact* _full_gc;
458 ShenandoahPacer* _pacer;
459 ShenandoahVerifier* _verifier;
460
461 ShenandoahAllocTracker* _alloc_tracker;
462 ShenandoahPhaseTimings* _phase_timings;
463
464 ShenandoahControlThread* control_thread() { return _control_thread; }
465 ShenandoahMarkCompact* full_gc() { return _full_gc; }
466
467 public:
468 ShenandoahCollectorPolicy* shenandoah_policy() const { return _shenandoah_policy; }
469 ShenandoahHeuristics* heuristics() const { return _heuristics; }
470 ShenandoahFreeSet* free_set() const { return _free_set; }
471 ShenandoahConcurrentMark* concurrent_mark() { return _scm; }
472 ShenandoahTraversalGC* traversal_gc() const { return _traversal_gc; }
473 bool is_traversal_mode() const { return _traversal_gc != NULL; }
474 ShenandoahPacer* pacer() const { return _pacer; }
475
476 ShenandoahPhaseTimings* phase_timings() const { return _phase_timings; }
477 ShenandoahAllocTracker* alloc_tracker() const { return _alloc_tracker; }
478
479 ShenandoahVerifier* verifier();
480
481 // ---------- VM subsystem bindings
482 //
483 private:
484 ShenandoahMonitoringSupport* _monitoring_support;
485 MemoryPool* _memory_pool;
486 GCMemoryManager _stw_memory_manager;
487 GCMemoryManager _cycle_memory_manager;
488 ConcurrentGCTimer* _gc_timer;
489 SoftRefPolicy _soft_ref_policy;
490
491 // For exporting to SA
492 int _log_min_obj_alignment_in_bytes;
493 public:
494 ShenandoahMonitoringSupport* monitoring_support() { return _monitoring_support; }
495 GCMemoryManager* cycle_memory_manager() { return &_cycle_memory_manager; }
496 GCMemoryManager* stw_memory_manager() { return &_stw_memory_manager; }
497 SoftRefPolicy* soft_ref_policy() { return &_soft_ref_policy; }
498
499 GrowableArray<GCMemoryManager*> memory_managers();
500 GrowableArray<MemoryPool*> memory_pools();
501 MemoryUsage memory_usage();
502 GCTracer* tracer();
503 GCTimer* gc_timer() const;
504
505 // ---------- Reference processing
506 //
507 private:
508 AlwaysTrueClosure _subject_to_discovery;
509 ReferenceProcessor* _ref_processor;
510 ShenandoahSharedFlag _process_references;
511
512 void ref_processing_init();
513
514 public:
515 ReferenceProcessor* ref_processor() { return _ref_processor; }
516 void set_process_references(bool pr);
517 bool process_references() const;
518
519 // ---------- Class Unloading
520 //
521 private:
522 ShenandoahSharedFlag _unload_classes;
523 ShenandoahUnload _unloader;
524
525 public:
526 void set_unload_classes(bool uc);
527 bool unload_classes() const;
528
529 // Perform STW class unloading and weak root cleaning
530 void parallel_cleaning(bool full_gc);
531
532 private:
533 void stw_unload_classes(bool full_gc);
534 void stw_process_weak_roots(bool full_gc);
535
536 // Prepare concurrent root processing
537 void prepare_concurrent_roots();
538 // Prepare and finish concurrent unloading
539 void prepare_concurrent_unloading();
540 void finish_concurrent_unloading();
541
542 // ---------- Generic interface hooks
543 // Minor things that super-interface expects us to implement to play nice with
544 // the rest of runtime. Some of the things here are not required to be implemented,
545 // and can be stubbed out.
546 //
547 public:
548 AdaptiveSizePolicy* size_policy() shenandoah_not_implemented_return(NULL);
549 bool is_maximal_no_gc() const shenandoah_not_implemented_return(false);
550
551 bool is_in(const void* p) const;
552
553 MemRegion reserved_region() const { return _reserved; }
554 bool is_in_reserved(const void* addr) const { return _reserved.contains(addr); }
555
556 void collect(GCCause::Cause cause);
557 void do_full_collection(bool clear_all_soft_refs);
558
559 // Used for parsing heap during error printing
560 HeapWord* block_start(const void* addr) const;
561 bool block_is_obj(const HeapWord* addr) const;
562 bool print_location(outputStream* st, void* addr) const;
563
564 // Used for native heap walkers: heap dumpers, mostly
565 void object_iterate(ObjectClosure* cl);
566
567 // Keep alive an object that was loaded with AS_NO_KEEPALIVE.
568 void keep_alive(oop obj);
569
570 // Used by RMI
571 jlong millis_since_last_gc();
572
573 // ---------- Safepoint interface hooks
574 //
575 public:
576 void safepoint_synchronize_begin();
577 void safepoint_synchronize_end();
578
579 // ---------- Code roots handling hooks
580 //
581 public:
582 void register_nmethod(nmethod* nm);
583 void unregister_nmethod(nmethod* nm);
584 void flush_nmethod(nmethod* nm);
585 void verify_nmethod(nmethod* nm) {}
586
587 // ---------- Pinning hooks
588 //
589 public:
590 // Shenandoah supports per-object (per-region) pinning
591 bool supports_object_pinning() const { return true; }
592
593 oop pin_object(JavaThread* thread, oop obj);
594 void unpin_object(JavaThread* thread, oop obj);
595
596 void sync_pinned_region_status();
597 void assert_pinned_region_status() NOT_DEBUG_RETURN;
598
599 // ---------- Allocation support
600 //
601 private:
602 HeapWord* allocate_memory_under_lock(ShenandoahAllocRequest& request, bool& in_new_region);
603 inline HeapWord* allocate_from_gclab(Thread* thread, size_t size);
604 HeapWord* allocate_from_gclab_slow(Thread* thread, size_t size);
605 HeapWord* allocate_new_gclab(size_t min_size, size_t word_size, size_t* actual_size);
606 void retire_and_reset_gclabs();
607
608 public:
609 HeapWord* allocate_memory(ShenandoahAllocRequest& request);
610 HeapWord* mem_allocate(size_t size, bool* what);
611 MetaWord* satisfy_failed_metadata_allocation(ClassLoaderData* loader_data,
612 size_t size,
613 Metaspace::MetadataType mdtype);
614
615 void notify_mutator_alloc_words(size_t words, bool waste);
616
617 // Shenandoah supports TLAB allocation
618 bool supports_tlab_allocation() const { return true; }
619
620 HeapWord* allocate_new_tlab(size_t min_size, size_t requested_size, size_t* actual_size);
621 size_t tlab_capacity(Thread *thr) const;
622 size_t unsafe_max_tlab_alloc(Thread *thread) const;
623 size_t max_tlab_size() const;
624 size_t tlab_used(Thread* ignored) const;
625
626 void resize_tlabs();
627
628 void ensure_parsability(bool retire_tlabs);
629 void make_parsable(bool retire_tlabs);
630
631 // ---------- Marking support
632 //
633 private:
634 ShenandoahMarkingContext* _marking_context;
635 MemRegion _bitmap_region;
636 MemRegion _aux_bitmap_region;
637 MarkBitMap _verification_bit_map;
638 MarkBitMap _aux_bit_map;
639
640 size_t _bitmap_size;
641 size_t _bitmap_regions_per_slice;
642 size_t _bitmap_bytes_per_slice;
643
644 bool _bitmap_region_special;
645 bool _aux_bitmap_region_special;
646
647 // Used for buffering per-region liveness data.
648 // Needed since ShenandoahHeapRegion uses atomics to update liveness.
649 //
650 // The array has max-workers elements, each of which is an array of
651 // jushort * max_regions. The choice of jushort is not accidental:
652 // there is a tradeoff between static/dynamic footprint that translates
653 // into cache pressure (which is already high during marking), and
654 // too many atomic updates. size_t/jint is too large, jbyte is too small.
655 jushort** _liveness_cache;
656
657 public:
658 inline ShenandoahMarkingContext* complete_marking_context() const;
659 inline ShenandoahMarkingContext* marking_context() const;
660 inline void mark_complete_marking_context();
661 inline void mark_incomplete_marking_context();
662
663 template<class T>
664 inline void marked_object_iterate(ShenandoahHeapRegion* region, T* cl);
665
666 template<class T>
667 inline void marked_object_iterate(ShenandoahHeapRegion* region, T* cl, HeapWord* limit);
668
669 template<class T>
670 inline void marked_object_oop_iterate(ShenandoahHeapRegion* region, T* cl, HeapWord* limit);
671
672 void reset_mark_bitmap();
673
674 // SATB barriers hooks
675 template<bool RESOLVE>
676 inline bool requires_marking(const void* entry) const;
677 void force_satb_flush_all_threads();
678
679 // Support for bitmap uncommits
680 bool commit_bitmap_slice(ShenandoahHeapRegion *r);
681 bool uncommit_bitmap_slice(ShenandoahHeapRegion *r);
682 bool is_bitmap_slice_committed(ShenandoahHeapRegion* r, bool skip_self = false);
683
684 // Liveness caching support
685 jushort* get_liveness_cache(uint worker_id);
686 void flush_liveness_cache(uint worker_id);
687
688 // ---------- Evacuation support
689 //
690 private:
691 ShenandoahCollectionSet* _collection_set;
692 ShenandoahEvacOOMHandler _oom_evac_handler;
693
694 void evacuate_and_update_roots();
695
696 public:
697 static address in_cset_fast_test_addr();
698
699 ShenandoahCollectionSet* collection_set() const { return _collection_set; }
700
701 // Checks if object is in the collection set.
702 inline bool in_collection_set(oop obj) const;
703
704 // Checks if location is in the collection set. Can be interior pointer, not the oop itself.
705 inline bool in_collection_set_loc(void* loc) const;
706
707 // Evacuates object src. Returns the evacuated object, either evacuated
708 // by this thread, or by some other thread.
709 inline oop evacuate_object(oop src, Thread* thread);
710
711 // Call before/after evacuation.
712 void enter_evacuation();
713 void leave_evacuation();
714
715 // ---------- Helper functions
716 //
717 public:
718 template <class T>
719 inline oop evac_update_with_forwarded(T* p);
720
721 template <class T>
722 inline oop maybe_update_with_forwarded(T* p);
723
724 template <class T>
725 inline oop maybe_update_with_forwarded_not_null(T* p, oop obj);
726
727 template <class T>
728 inline oop update_with_forwarded_not_null(T* p, oop obj);
729
730 static inline oop cas_oop(oop n, narrowOop* addr, oop c);
731 static inline oop cas_oop(oop n, oop* addr, oop c);
732 static inline oop cas_oop(oop n, narrowOop* addr, narrowOop c);
733
734 void trash_humongous_region_at(ShenandoahHeapRegion *r);
735
736 void deduplicate_string(oop str);
737
738 private:
739 void trash_cset_regions();
740 void update_heap_references(bool concurrent);
741
742 // ---------- Testing helpers functions
743 //
744 private:
745 ShenandoahSharedFlag _inject_alloc_failure;
746
747 void try_inject_alloc_failure();
748 bool should_inject_alloc_failure();
749 };
750
751 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHHEAP_HPP