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 ShenandoahHeuristics;
44 class ShenandoahMarkingContext;
45 class ShenandoahPhaseTimings;
46 class ShenandoahHeap;
47 class ShenandoahHeapRegion;
48 class ShenandoahHeapRegionClosure;
49 class ShenandoahCollectionSet;
50 class ShenandoahFreeSet;
51 class ShenandoahConcurrentMark;
52 class ShenandoahMarkCompact;
53 class ShenandoahMonitoringSupport;
54 class ShenandoahPacer;
55 class ShenandoahTraversalGC;
56 class ShenandoahVerifier;
57 class ShenandoahWorkGang;
58 class VMStructs;
59
60 class ShenandoahRegionIterator : public StackObj {
61 private:
62 ShenandoahHeap* _heap;
63
64 DEFINE_PAD_MINUS_SIZE(0, DEFAULT_CACHE_LINE_SIZE, sizeof(volatile size_t));
65 volatile size_t _index;
66 DEFINE_PAD_MINUS_SIZE(1, DEFAULT_CACHE_LINE_SIZE, 0);
67
68 // No implicit copying: iterators should be passed by reference to capture the state
69 ShenandoahRegionIterator(const ShenandoahRegionIterator& that);
70 ShenandoahRegionIterator& operator=(const ShenandoahRegionIterator& o);
71
72 public:
73 ShenandoahRegionIterator();
74 ShenandoahRegionIterator(ShenandoahHeap* heap);
75
76 // Reset iterator to default state
77 void reset();
78
79 // Returns next region, or NULL if there are no more regions.
80 // This is multi-thread-safe.
81 inline ShenandoahHeapRegion* next();
82
83 // This is *not* MT safe. However, in the absence of multithreaded access, it
84 // can be used to determine if there is more work to do.
85 bool has_next() const;
86 };
87
88 class ShenandoahHeapRegionClosure : public StackObj {
89 public:
90 virtual void heap_region_do(ShenandoahHeapRegion* r) = 0;
91 virtual bool is_thread_safe() { return false; }
92 };
93
94 class ShenandoahUpdateRefsClosure: public OopClosure {
95 private:
96 ShenandoahHeap* _heap;
97
98 template <class T>
99 inline void do_oop_work(T* p);
100
101 public:
102 ShenandoahUpdateRefsClosure();
103 inline void do_oop(oop* p);
104 inline void do_oop(narrowOop* p);
105 };
106
107 #ifdef ASSERT
108 class ShenandoahAssertToSpaceClosure : public OopClosure {
109 private:
110 template <class T>
111 void do_oop_work(T* p);
112 public:
113 void do_oop(narrowOop* p);
114 void do_oop(oop* p);
115 };
116 #endif
117
118 class ShenandoahAlwaysTrueClosure : public BoolObjectClosure {
119 public:
120 bool do_object_b(oop p) { return true; }
121 };
122
123 class ShenandoahForwardedIsAliveClosure: public BoolObjectClosure {
124 private:
125 ShenandoahMarkingContext* const _mark_context;
126 public:
127 ShenandoahForwardedIsAliveClosure();
128 bool do_object_b(oop obj);
129 };
130
131 class ShenandoahIsAliveClosure: public BoolObjectClosure {
132 private:
133 ShenandoahMarkingContext* const _mark_context;
134 public:
135 ShenandoahIsAliveClosure();
136 bool do_object_b(oop obj);
137 };
138
139 class ShenandoahIsAliveSelector : public StackObj {
140 private:
141 ShenandoahIsAliveClosure _alive_cl;
142 ShenandoahForwardedIsAliveClosure _fwd_alive_cl;
143 public:
144 BoolObjectClosure* is_alive_closure();
145 };
146
147 // Shenandoah GC is low-pause concurrent GC that uses Brooks forwarding pointers
148 // to encode forwarding data. See BrooksPointer for details on forwarding data encoding.
149 // See ShenandoahControlThread for GC cycle structure.
150 //
151 class ShenandoahHeap : public CollectedHeap {
152 friend class ShenandoahAsserts;
153 friend class VMStructs;
154 friend class ShenandoahGCSession;
155
156 // ---------- Locks that guard important data structures in Heap
157 //
158 private:
159 ShenandoahHeapLock _lock;
160
161 public:
162 ShenandoahHeapLock* lock() {
163 return &_lock;
164 }
165
166 void assert_heaplock_owned_by_current_thread() NOT_DEBUG_RETURN;
167 void assert_heaplock_not_owned_by_current_thread() NOT_DEBUG_RETURN;
168 void assert_heaplock_or_safepoint() NOT_DEBUG_RETURN;
169
170 // ---------- Initialization, termination, identification, printing routines
171 //
172 public:
173 static ShenandoahHeap* heap();
174 static ShenandoahHeap* heap_no_check();
175
176 const char* name() const { return "Shenandoah"; }
177 ShenandoahHeap::Name kind() const { return CollectedHeap::Shenandoah; }
178
179 ShenandoahHeap(ShenandoahCollectorPolicy* policy);
180 jint initialize();
181 void post_initialize();
182 void initialize_heuristics();
183
184 void initialize_serviceability();
185
186 void print_on(outputStream* st) const;
187 void print_extended_on(outputStream *st) const;
188 void print_tracing_info() const;
189 void print_gc_threads_on(outputStream* st) const;
190 void print_heap_regions_on(outputStream* st) const;
191
192 void stop();
193
194 void prepare_for_verify();
195 void verify(VerifyOption vo);
196
197 // ---------- Heap counters and metrics
198 //
199 private:
200 size_t _initial_size;
201 DEFINE_PAD_MINUS_SIZE(0, DEFAULT_CACHE_LINE_SIZE, sizeof(volatile size_t));
202 volatile size_t _used;
203 volatile size_t _committed;
204 volatile size_t _bytes_allocated_since_gc_start;
205 DEFINE_PAD_MINUS_SIZE(1, DEFAULT_CACHE_LINE_SIZE, 0);
206
207 public:
208 void increase_used(size_t bytes);
209 void decrease_used(size_t bytes);
210 void set_used(size_t bytes);
211
212 void increase_committed(size_t bytes);
213 void decrease_committed(size_t bytes);
214 void increase_allocated(size_t bytes);
215
216 size_t bytes_allocated_since_gc_start();
217 void reset_bytes_allocated_since_gc_start();
218
219 size_t max_capacity() const;
220 size_t initial_capacity() const;
221 size_t capacity() const;
222 size_t used() const;
223 size_t committed() const;
224
225 // ---------- Workers handling
226 //
227 private:
228 uint _max_workers;
229 ShenandoahWorkGang* _workers;
230 ShenandoahWorkGang* _safepoint_workers;
231
232 public:
233 uint max_workers();
234 void assert_gc_workers(uint nworker) NOT_DEBUG_RETURN;
235
236 WorkGang* workers() const;
237 WorkGang* get_safepoint_workers();
238
239 void gc_threads_do(ThreadClosure* tcl) const;
240
241 // ---------- Heap regions handling machinery
242 //
243 private:
244 MemRegion _heap_region;
245 size_t _num_regions;
246 ShenandoahHeapRegion** _regions;
247 ShenandoahRegionIterator _update_refs_iterator;
248
249 public:
250 inline size_t num_regions() const { return _num_regions; }
251
252 inline ShenandoahHeapRegion* const heap_region_containing(const void* addr) const;
253 inline size_t heap_region_index_containing(const void* addr) const;
254
255 inline ShenandoahHeapRegion* const get_region(size_t region_idx) const;
256
257 void heap_region_iterate(ShenandoahHeapRegionClosure* blk) const;
258 void parallel_heap_region_iterate(ShenandoahHeapRegionClosure* blk) const;
259
260 // ---------- GC state machinery
261 //
262 // GC state describes the important parts of collector state, that may be
263 // used to make barrier selection decisions in the native and generated code.
264 // Multiple bits can be set at once.
265 //
266 // Important invariant: when GC state is zero, the heap is stable, and no barriers
267 // are required.
268 //
269 public:
270 enum GCStateBitPos {
271 // Heap has forwarded objects: need RB, ACMP, CAS barriers.
272 HAS_FORWARDED_BITPOS = 0,
273
274 // Heap is under marking: needs SATB barriers.
275 MARKING_BITPOS = 1,
276
277 // Heap is under evacuation: needs WB barriers. (Set together with UNSTABLE)
278 EVACUATION_BITPOS = 2,
279
280 // Heap is under updating: needs SVRB/SVWB barriers.
281 UPDATEREFS_BITPOS = 3,
282
283 // Heap is under traversal collection
284 TRAVERSAL_BITPOS = 4,
285 };
286
287 enum GCState {
288 STABLE = 0,
289 HAS_FORWARDED = 1 << HAS_FORWARDED_BITPOS,
290 MARKING = 1 << MARKING_BITPOS,
291 EVACUATION = 1 << EVACUATION_BITPOS,
292 UPDATEREFS = 1 << UPDATEREFS_BITPOS,
293 TRAVERSAL = 1 << TRAVERSAL_BITPOS,
294 };
295
296 private:
297 ShenandoahSharedBitmap _gc_state;
298 ShenandoahSharedFlag _degenerated_gc_in_progress;
299 ShenandoahSharedFlag _full_gc_in_progress;
300 ShenandoahSharedFlag _full_gc_move_in_progress;
301 ShenandoahSharedFlag _progress_last_gc;
302
303 void set_gc_state_all_threads(char state);
304 void set_gc_state_mask(uint mask, bool value);
305
306 public:
307 char gc_state() const;
308 static address gc_state_addr();
309
310 void set_concurrent_mark_in_progress(bool in_progress);
311 void set_evacuation_in_progress(bool in_progress);
312 void set_update_refs_in_progress(bool in_progress);
313 void set_degenerated_gc_in_progress(bool in_progress);
314 void set_full_gc_in_progress(bool in_progress);
315 void set_full_gc_move_in_progress(bool in_progress);
316 void set_concurrent_traversal_in_progress(bool in_progress);
317 void set_has_forwarded_objects(bool cond);
318
319 inline bool is_stable() const;
320 inline bool is_idle() const;
321 inline bool is_concurrent_mark_in_progress() const;
322 inline bool is_update_refs_in_progress() const;
323 inline bool is_evacuation_in_progress() const;
324 inline bool is_degenerated_gc_in_progress() const;
325 inline bool is_full_gc_in_progress() const;
326 inline bool is_full_gc_move_in_progress() const;
327 inline bool is_concurrent_traversal_in_progress() const;
328 inline bool has_forwarded_objects() const;
329 inline bool is_gc_in_progress_mask(uint mask) const;
330
331 // ---------- GC cancellation and degeneration machinery
332 //
333 // Cancelled GC flag is used to notify concurrent phases that they should terminate.
334 //
335 public:
336 enum ShenandoahDegenPoint {
337 _degenerated_unset,
338 _degenerated_traversal,
339 _degenerated_outside_cycle,
340 _degenerated_mark,
341 _degenerated_evac,
342 _degenerated_updaterefs,
343 _DEGENERATED_LIMIT,
344 };
345
346 static const char* degen_point_to_string(ShenandoahDegenPoint point) {
347 switch (point) {
348 case _degenerated_unset:
349 return "<UNSET>";
350 case _degenerated_traversal:
351 return "Traversal";
352 case _degenerated_outside_cycle:
353 return "Outside of Cycle";
354 case _degenerated_mark:
355 return "Mark";
356 case _degenerated_evac:
357 return "Evacuation";
358 case _degenerated_updaterefs:
359 return "Update Refs";
360 default:
361 ShouldNotReachHere();
362 return "ERROR";
363 }
364 };
365
366 private:
367 enum CancelState {
368 // Normal state. GC has not been cancelled and is open for cancellation.
369 // Worker threads can suspend for safepoint.
370 CANCELLABLE,
371
372 // GC has been cancelled. Worker threads can not suspend for
373 // safepoint but must finish their work as soon as possible.
374 CANCELLED,
375
376 // GC has not been cancelled and must not be cancelled. At least
377 // one worker thread checks for pending safepoint and may suspend
378 // if a safepoint is pending.
379 NOT_CANCELLED
380 };
381
382 ShenandoahSharedEnumFlag<CancelState> _cancelled_gc;
383 bool try_cancel_gc();
384
385 public:
386 static address cancelled_gc_addr();
387
388 inline bool cancelled_gc() const;
389 inline bool check_cancelled_gc_and_yield(bool sts_active = true);
390
391 inline void clear_cancelled_gc();
392
393 void cancel_gc(GCCause::Cause cause);
394
395 // ---------- GC operations entry points
396 //
397 public:
398 // Entry points to STW GC operations, these cause a related safepoint, that then
399 // call the entry method below
400 void vmop_entry_init_mark();
401 void vmop_entry_final_mark();
402 void vmop_entry_final_evac();
403 void vmop_entry_init_updaterefs();
404 void vmop_entry_final_updaterefs();
405 void vmop_entry_init_traversal();
406 void vmop_entry_final_traversal();
407 void vmop_entry_full(GCCause::Cause cause);
408 void vmop_degenerated(ShenandoahDegenPoint point);
409
410 // Entry methods to normally STW GC operations. These set up logging, monitoring
411 // and workers for net VM operation
412 void entry_init_mark();
413 void entry_final_mark();
414 void entry_final_evac();
415 void entry_init_updaterefs();
416 void entry_final_updaterefs();
417 void entry_init_traversal();
418 void entry_final_traversal();
419 void entry_full(GCCause::Cause cause);
420 void entry_degenerated(int point);
421
422 // Entry methods to normally concurrent GC operations. These set up logging, monitoring
423 // for concurrent operation.
424 void entry_reset();
425 void entry_mark();
426 void entry_preclean();
427 void entry_cleanup();
428 void entry_evac();
429 void entry_updaterefs();
430 void entry_traversal();
431 void entry_uncommit(double shrink_before);
432
433 private:
434 // Actual work for the phases
435 void op_init_mark();
436 void op_final_mark();
437 void op_final_evac();
438 void op_init_updaterefs();
439 void op_final_updaterefs();
440 void op_init_traversal();
441 void op_final_traversal();
442 void op_full(GCCause::Cause cause);
443 void op_degenerated(ShenandoahDegenPoint point);
444 void op_degenerated_fail();
445 void op_degenerated_futile();
446
447 void op_reset();
448 void op_mark();
449 void op_preclean();
450 void op_cleanup();
451 void op_conc_evac();
452 void op_stw_evac();
453 void op_updaterefs();
454 void op_traversal();
455 void op_uncommit(double shrink_before);
456
457 // Messages for GC trace events, they have to be immortal for
458 // passing around the logging/tracing systems
459 const char* init_mark_event_message() const;
460 const char* final_mark_event_message() const;
461 const char* conc_mark_event_message() const;
462 const char* degen_event_message(ShenandoahDegenPoint point) const;
463
464 // ---------- GC subsystems
465 //
466 private:
467 ShenandoahControlThread* _control_thread;
468 ShenandoahCollectorPolicy* _shenandoah_policy;
469 ShenandoahHeuristics* _heuristics;
470 ShenandoahFreeSet* _free_set;
471 ShenandoahConcurrentMark* _scm;
472 ShenandoahTraversalGC* _traversal_gc;
473 ShenandoahMarkCompact* _full_gc;
474 ShenandoahPacer* _pacer;
475 ShenandoahVerifier* _verifier;
476
477 ShenandoahAllocTracker* _alloc_tracker;
478 ShenandoahPhaseTimings* _phase_timings;
479
480 ShenandoahControlThread* control_thread() { return _control_thread; }
481 ShenandoahMarkCompact* full_gc() { return _full_gc; }
482
483 public:
484 ShenandoahCollectorPolicy* shenandoah_policy() const { return _shenandoah_policy; }
485 ShenandoahHeuristics* heuristics() const { return _heuristics; }
486 ShenandoahFreeSet* free_set() const { return _free_set; }
487 ShenandoahConcurrentMark* concurrent_mark() { return _scm; }
488 ShenandoahTraversalGC* traversal_gc() { return _traversal_gc; }
489 ShenandoahPacer* pacer() const { return _pacer; }
490
491 ShenandoahPhaseTimings* phase_timings() const { return _phase_timings; }
492 ShenandoahAllocTracker* alloc_tracker() const { return _alloc_tracker; }
493
494 ShenandoahVerifier* verifier();
495
496 // ---------- VM subsystem bindings
497 //
498 private:
499 ShenandoahMonitoringSupport* _monitoring_support;
500 MemoryPool* _memory_pool;
501 GCMemoryManager _stw_memory_manager;
502 GCMemoryManager _cycle_memory_manager;
503 ConcurrentGCTimer* _gc_timer;
504 SoftRefPolicy _soft_ref_policy;
505
506 public:
507 ShenandoahMonitoringSupport* monitoring_support() { return _monitoring_support; }
508 GCMemoryManager* cycle_memory_manager() { return &_cycle_memory_manager; }
509 GCMemoryManager* stw_memory_manager() { return &_stw_memory_manager; }
510 SoftRefPolicy* soft_ref_policy() { return &_soft_ref_policy; }
511
512 GrowableArray<GCMemoryManager*> memory_managers();
513 GrowableArray<MemoryPool*> memory_pools();
514 MemoryUsage memory_usage();
515 GCTracer* tracer();
516 GCTimer* gc_timer() const;
517 CollectorPolicy* collector_policy() const;
518
519 // ---------- Reference processing
520 //
521 private:
522 AlwaysTrueClosure _subject_to_discovery;
523 ReferenceProcessor* _ref_processor;
524 ShenandoahSharedFlag _process_references;
525
526 void ref_processing_init();
527
528 public:
529 ReferenceProcessor* ref_processor() { return _ref_processor; }
530 void set_process_references(bool pr);
531 bool process_references() const;
532
533 // ---------- Class Unloading
534 //
535 private:
536 ShenandoahSharedFlag _unload_classes;
537
538 public:
539 void set_unload_classes(bool uc);
540 bool unload_classes() const;
541
542 // Delete entries for dead interned string and clean up unreferenced symbols
543 // in symbol table, possibly in parallel.
544 void unload_classes_and_cleanup_tables(bool full_gc);
545
546 // ---------- Generic interface hooks
547 // Minor things that super-interface expects us to implement to play nice with
548 // the rest of runtime. Some of the things here are not required to be implemented,
549 // and can be stubbed out.
550 //
551 public:
552 AdaptiveSizePolicy* size_policy() shenandoah_not_implemented_return(NULL);
553 bool is_maximal_no_gc() const shenandoah_not_implemented_return(false);
554
555 bool is_in(const void* p) const;
556
557 size_t obj_size(oop obj) const;
558 virtual ptrdiff_t cell_header_size() const;
559
560 // All objects can potentially move
561 bool is_scavengable(oop obj) { return true; };
562
563 void collect(GCCause::Cause cause);
564 void do_full_collection(bool clear_all_soft_refs);
565
566 // Used for parsing heap during error printing
567 HeapWord* block_start(const void* addr) const;
568 size_t block_size(const HeapWord* addr) const;
569 bool block_is_obj(const HeapWord* addr) const;
570
571 // Used for native heap walkers: heap dumpers, mostly
572 void object_iterate(ObjectClosure* cl);
573 void safe_object_iterate(ObjectClosure* cl);
574
575 // Used by RMI
576 jlong millis_since_last_gc();
577
578 // ---------- Safepoint interface hooks
579 //
580 public:
581 void safepoint_synchronize_begin();
582 void safepoint_synchronize_end();
583
584 // ---------- Code roots handling hooks
585 //
586 public:
587 void register_nmethod(nmethod* nm);
588 void unregister_nmethod(nmethod* nm);
589
590 // ---------- Pinning hooks
591 //
592 public:
593 // Shenandoah supports per-object (per-region) pinning
594 bool supports_object_pinning() const { return true; }
595
596 oop pin_object(JavaThread* thread, oop obj);
597 void unpin_object(JavaThread* thread, oop obj);
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 oop obj_allocate(Klass* klass, int size, TRAPS);
616 oop array_allocate(Klass* klass, int size, int length, bool do_zero, TRAPS);
617 oop class_allocate(Klass* klass, int size, TRAPS);
618
619 void notify_mutator_alloc_words(size_t words, bool waste);
620
621 // Shenandoah supports TLAB allocation
622 bool supports_tlab_allocation() const { return true; }
623
624 HeapWord* allocate_new_tlab(size_t min_size, size_t requested_size, size_t* actual_size);
625 size_t tlab_capacity(Thread *thr) const;
626 size_t unsafe_max_tlab_alloc(Thread *thread) const;
627 size_t max_tlab_size() const;
628 size_t tlab_used(Thread* ignored) const;
629
630 HeapWord* tlab_post_allocation_setup(HeapWord* obj);
631 void fill_with_dummy_object(HeapWord* start, HeapWord* end, bool zap);
632 size_t min_dummy_object_size() const;
633
634 void resize_tlabs();
635
636 void ensure_parsability(bool retire_tlabs);
637 void make_parsable(bool retire_tlabs);
638
639 // ---------- Marking support
640 //
641 private:
642 ShenandoahMarkingContext* _marking_context;
643 MemRegion _bitmap_region;
644 MemRegion _aux_bitmap_region;
645 MarkBitMap _verification_bit_map;
646 MarkBitMap _aux_bit_map;
647
648 size_t _bitmap_size;
649 size_t _bitmap_regions_per_slice;
650 size_t _bitmap_bytes_per_slice;
651
652 // Used for buffering per-region liveness data.
653 // Needed since ShenandoahHeapRegion uses atomics to update liveness.
654 //
655 // The array has max-workers elements, each of which is an array of
656 // jushort * max_regions. The choice of jushort is not accidental:
657 // there is a tradeoff between static/dynamic footprint that translates
658 // into cache pressure (which is already high during marking), and
659 // too many atomic updates. size_t/jint is too large, jbyte is too small.
660 jushort** _liveness_cache;
661
662 public:
663 inline ShenandoahMarkingContext* complete_marking_context() const;
664 inline ShenandoahMarkingContext* marking_context() const;
665 inline void mark_complete_marking_context();
666 inline void mark_incomplete_marking_context();
667
668 template<class T>
669 inline void marked_object_iterate(ShenandoahHeapRegion* region, T* cl);
670
671 template<class T>
672 inline void marked_object_iterate(ShenandoahHeapRegion* region, T* cl, HeapWord* limit);
673
674 template<class T>
675 inline void marked_object_oop_iterate(ShenandoahHeapRegion* region, T* cl, HeapWord* limit);
676
677 void reset_mark_bitmap();
678
679 // SATB barriers hooks
680 template<bool RESOLVE>
681 inline bool requires_marking(const void* entry) const;
682 void force_satb_flush_all_threads();
683
684 // Support for bitmap uncommits
685 bool commit_bitmap_slice(ShenandoahHeapRegion *r);
686 bool uncommit_bitmap_slice(ShenandoahHeapRegion *r);
687 bool is_bitmap_slice_committed(ShenandoahHeapRegion* r, bool skip_self = false);
688
689 // Liveness caching support
690 jushort* get_liveness_cache(uint worker_id);
691 void flush_liveness_cache(uint worker_id);
692
693 // ---------- Evacuation support
694 //
695 private:
696 ShenandoahCollectionSet* _collection_set;
697 ShenandoahEvacOOMHandler _oom_evac_handler;
698
699 void evacuate_and_update_roots();
700
701 public:
702 static address in_cset_fast_test_addr();
703
704 ShenandoahCollectionSet* collection_set() const { return _collection_set; }
705
706 template <class T>
707 inline bool in_collection_set(T obj) const;
708
709 // Avoid accidentally calling the method above with ShenandoahHeapRegion*, which would be *wrong*.
710 inline bool in_collection_set(ShenandoahHeapRegion* r) shenandoah_not_implemented_return(false);
711
712 // Evacuates object src. Returns the evacuated object, either evacuated
713 // by this thread, or by some other thread.
714 inline oop evacuate_object(oop src, Thread* thread);
715
716 // Call before/after evacuation.
717 void enter_evacuation();
718 void leave_evacuation();
719
720 // ---------- Helper functions
721 //
722 public:
723 template <class T>
724 inline oop evac_update_with_forwarded(T* p);
725
726 template <class T>
727 inline oop maybe_update_with_forwarded(T* p);
728
729 template <class T>
730 inline oop maybe_update_with_forwarded_not_null(T* p, oop obj);
731
732 template <class T>
733 inline oop update_with_forwarded_not_null(T* p, oop obj);
734
735 inline oop atomic_compare_exchange_oop(oop n, narrowOop* addr, oop c);
736 inline oop atomic_compare_exchange_oop(oop n, oop* addr, oop c);
737
738 void trash_humongous_region_at(ShenandoahHeapRegion *r);
739
740 void deduplicate_string(oop str);
741
742 void stop_concurrent_marking();
743
744 void roots_iterate(OopClosure* cl);
745
746 private:
747 void trash_cset_regions();
748 void update_heap_references(bool concurrent);
749
750 // ---------- Testing helpers functions
751 //
752 private:
753 ShenandoahSharedFlag _inject_alloc_failure;
754
755 void try_inject_alloc_failure();
756 bool should_inject_alloc_failure();
757 };
758
759 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHHEAP_HPP