1 /*
2 * Copyright (c) 2013, 2019, Red Hat, Inc. All rights reserved.
3 *
4 * This code is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 only, as
6 * published by the Free Software Foundation.
7 *
8 * This code is distributed in the hope that it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
11 * version 2 for more details (a copy is included in the LICENSE file that
12 * accompanied this code).
13 *
14 * You should have received a copy of the GNU General Public License version
15 * 2 along with this work; if not, write to the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
17 *
18 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
19 * or visit www.oracle.com if you need additional information or have any
20 * questions.
21 *
22 */
23
24 #ifndef SHARE_GC_SHENANDOAH_SHENANDOAHHEAP_HPP
25 #define SHARE_GC_SHENANDOAH_SHENANDOAHHEAP_HPP
26
27 #include "gc/shared/markBitMap.hpp"
28 #include "gc/shared/softRefPolicy.hpp"
29 #include "gc/shared/collectedHeap.hpp"
30 #include "gc/shenandoah/shenandoahAsserts.hpp"
31 #include "gc/shenandoah/shenandoahAllocRequest.hpp"
32 #include "gc/shenandoah/shenandoahLock.hpp"
33 #include "gc/shenandoah/shenandoahEvacOOMHandler.hpp"
34 #include "gc/shenandoah/shenandoahSharedVariables.hpp"
35 #include "gc/shenandoah/shenandoahUnload.hpp"
36 #include "services/memoryManager.hpp"
37 #include "utilities/globalDefinitions.hpp"
38
39 class ConcurrentGCTimer;
40 class ReferenceProcessor;
41 class ShenandoahAllocTracker;
42 class ShenandoahCollectorPolicy;
43 class ShenandoahControlThread;
44 class ShenandoahGCSession;
45 class ShenandoahGCStateResetter;
46 class ShenandoahHeuristics;
47 class ShenandoahMarkingContext;
48 class ShenandoahMarkCompact;
49 class ShenandoahMode;
50 class ShenandoahPhaseTimings;
51 class ShenandoahHeap;
52 class ShenandoahHeapRegion;
53 class ShenandoahHeapRegionClosure;
54 class ShenandoahCollectionSet;
55 class ShenandoahFreeSet;
56 class ShenandoahConcurrentMark;
57 class ShenandoahMarkCompact;
58 class ShenandoahMonitoringSupport;
59 class ShenandoahPacer;
60 class ShenandoahTraversalGC;
61 class ShenandoahVerifier;
62 class ShenandoahWorkGang;
63 class VMStructs;
64
65 class ShenandoahRegionIterator : public StackObj {
66 private:
67 ShenandoahHeap* _heap;
68
69 DEFINE_PAD_MINUS_SIZE(0, DEFAULT_CACHE_LINE_SIZE, sizeof(volatile size_t));
70 volatile size_t _index;
71 DEFINE_PAD_MINUS_SIZE(1, DEFAULT_CACHE_LINE_SIZE, 0);
72
73 // No implicit copying: iterators should be passed by reference to capture the state
74 NONCOPYABLE(ShenandoahRegionIterator);
75
76 public:
77 ShenandoahRegionIterator();
78 ShenandoahRegionIterator(ShenandoahHeap* heap);
79
80 // Reset iterator to default state
81 void reset();
82
83 // Returns next region, or NULL if there are no more regions.
84 // This is multi-thread-safe.
85 inline ShenandoahHeapRegion* next();
86
87 // This is *not* MT safe. However, in the absence of multithreaded access, it
88 // can be used to determine if there is more work to do.
89 bool has_next() const;
90 };
91
92 class ShenandoahHeapRegionClosure : public StackObj {
93 public:
94 virtual void heap_region_do(ShenandoahHeapRegion* r) = 0;
95 virtual bool is_thread_safe() { return false; }
96 };
97
98 #ifdef ASSERT
99 class ShenandoahAssertToSpaceClosure : public OopClosure {
100 private:
101 template <class T>
102 void do_oop_work(T* p);
103 public:
104 void do_oop(narrowOop* p);
105 void do_oop(oop* p);
106 };
107 #endif
108
109 typedef ShenandoahLock ShenandoahHeapLock;
110 typedef ShenandoahLocker ShenandoahHeapLocker;
111
112 // Shenandoah GC is low-pause concurrent GC that uses Brooks forwarding pointers
113 // to encode forwarding data. See BrooksPointer for details on forwarding data encoding.
114 // See ShenandoahControlThread for GC cycle structure.
115 //
116 class ShenandoahHeap : public CollectedHeap {
117 friend class ShenandoahAsserts;
118 friend class VMStructs;
119 friend class ShenandoahGCSession;
120 friend class ShenandoahGCStateResetter;
121
122 // ---------- Locks that guard important data structures in Heap
123 //
124 private:
125 ShenandoahHeapLock _lock;
126
127 public:
128 ShenandoahHeapLock* lock() {
129 return &_lock;
130 }
131
132 void assert_heaplock_owned_by_current_thread() NOT_DEBUG_RETURN;
133 void assert_heaplock_not_owned_by_current_thread() NOT_DEBUG_RETURN;
134 void assert_heaplock_or_safepoint() NOT_DEBUG_RETURN;
135
136 // ---------- Initialization, termination, identification, printing routines
137 //
138 public:
139 static ShenandoahHeap* heap();
140 static ShenandoahHeap* heap_no_check();
141
142 const char* name() const { return "Shenandoah"; }
143 ShenandoahHeap::Name kind() const { return CollectedHeap::Shenandoah; }
144
145 ShenandoahHeap(ShenandoahCollectorPolicy* policy);
146 jint initialize();
147 void post_initialize();
148 void initialize_heuristics();
149
150 void initialize_serviceability();
151
152 void print_on(outputStream* st) const;
153 void print_extended_on(outputStream *st) const;
154 void print_tracing_info() const;
155 void print_gc_threads_on(outputStream* st) const;
156 void print_heap_regions_on(outputStream* st) const;
157
158 void stop();
159
160 void prepare_for_verify();
161 void verify(VerifyOption vo);
162
163 // ---------- Heap counters and metrics
164 //
165 private:
166 size_t _initial_size;
167 size_t _minimum_size;
168 DEFINE_PAD_MINUS_SIZE(0, DEFAULT_CACHE_LINE_SIZE, sizeof(volatile size_t));
169 volatile size_t _used;
170 volatile size_t _committed;
171 volatile size_t _bytes_allocated_since_gc_start;
172 DEFINE_PAD_MINUS_SIZE(1, DEFAULT_CACHE_LINE_SIZE, 0);
173
174 public:
175 void increase_used(size_t bytes);
176 void decrease_used(size_t bytes);
177 void set_used(size_t bytes);
178
179 void increase_committed(size_t bytes);
180 void decrease_committed(size_t bytes);
181 void increase_allocated(size_t bytes);
182
183 size_t bytes_allocated_since_gc_start();
184 void reset_bytes_allocated_since_gc_start();
185
186 size_t min_capacity() const;
187 size_t max_capacity() const;
188 size_t initial_capacity() const;
189 size_t capacity() const;
190 size_t used() const;
191 size_t committed() const;
192
193 // ---------- Workers handling
194 //
195 private:
196 uint _max_workers;
197 ShenandoahWorkGang* _workers;
198 ShenandoahWorkGang* _safepoint_workers;
199
200 public:
201 uint max_workers();
202 void assert_gc_workers(uint nworker) NOT_DEBUG_RETURN;
203
204 WorkGang* workers() const;
205 WorkGang* get_safepoint_workers();
206
207 void gc_threads_do(ThreadClosure* tcl) const;
208
209 // ---------- Heap regions handling machinery
210 //
211 private:
212 MemRegion _heap_region;
213 bool _heap_region_special;
214 size_t _num_regions;
215 ShenandoahHeapRegion** _regions;
216 ShenandoahRegionIterator _update_refs_iterator;
217
218 public:
219
220 inline HeapWord* base() const { return _heap_region.start(); }
221
222 inline size_t num_regions() const { return _num_regions; }
223 inline bool is_heap_region_special() { return _heap_region_special; }
224
225 inline ShenandoahHeapRegion* const heap_region_containing(const void* addr) const;
226 inline size_t heap_region_index_containing(const void* addr) const;
227
228 inline ShenandoahHeapRegion* const get_region(size_t region_idx) const;
229
230 void heap_region_iterate(ShenandoahHeapRegionClosure* blk) const;
231 void parallel_heap_region_iterate(ShenandoahHeapRegionClosure* blk) const;
232
233 // ---------- GC state machinery
234 //
235 // GC state describes the important parts of collector state, that may be
236 // used to make barrier selection decisions in the native and generated code.
237 // Multiple bits can be set at once.
238 //
239 // Important invariant: when GC state is zero, the heap is stable, and no barriers
240 // are required.
241 //
242 public:
243 enum GCStateBitPos {
244 // Heap has forwarded objects: needs LRB barriers.
245 HAS_FORWARDED_BITPOS = 0,
246
247 // Heap is under marking: needs SATB barriers.
248 MARKING_BITPOS = 1,
249
250 // Heap is under evacuation: needs LRB barriers. (Set together with HAS_FORWARDED)
251 EVACUATION_BITPOS = 2,
252
253 // Heap is under updating: needs no additional barriers.
254 UPDATEREFS_BITPOS = 3,
255
256 // Heap is under traversal collection
257 TRAVERSAL_BITPOS = 4
258 };
259
260 enum GCState {
261 STABLE = 0,
262 HAS_FORWARDED = 1 << HAS_FORWARDED_BITPOS,
263 MARKING = 1 << MARKING_BITPOS,
264 EVACUATION = 1 << EVACUATION_BITPOS,
265 UPDATEREFS = 1 << UPDATEREFS_BITPOS,
266 TRAVERSAL = 1 << TRAVERSAL_BITPOS
267 };
268
269 private:
270 ShenandoahSharedBitmap _gc_state;
271 ShenandoahSharedFlag _degenerated_gc_in_progress;
272 ShenandoahSharedFlag _full_gc_in_progress;
273 ShenandoahSharedFlag _full_gc_move_in_progress;
274 ShenandoahSharedFlag _progress_last_gc;
275 ShenandoahSharedFlag _concurrent_root_in_progress;
276
277 void set_gc_state_all_threads(char state);
278 void set_gc_state_mask(uint mask, bool value);
279
280 public:
281 char gc_state() const;
282 static address gc_state_addr();
283
284 void set_concurrent_mark_in_progress(bool in_progress);
285 void set_evacuation_in_progress(bool in_progress);
286 void set_update_refs_in_progress(bool in_progress);
287 void set_degenerated_gc_in_progress(bool in_progress);
288 void set_full_gc_in_progress(bool in_progress);
289 void set_full_gc_move_in_progress(bool in_progress);
290 void set_concurrent_traversal_in_progress(bool in_progress);
291 void set_has_forwarded_objects(bool cond);
292 void set_concurrent_root_in_progress(bool cond);
293
294 inline bool is_stable() const;
295 inline bool is_idle() const;
296 inline bool is_concurrent_mark_in_progress() const;
297 inline bool is_update_refs_in_progress() const;
298 inline bool is_evacuation_in_progress() const;
299 inline bool is_degenerated_gc_in_progress() const;
300 inline bool is_full_gc_in_progress() const;
301 inline bool is_full_gc_move_in_progress() const;
302 inline bool is_concurrent_traversal_in_progress() const;
303 inline bool has_forwarded_objects() const;
304 inline bool is_gc_in_progress_mask(uint mask) const;
305 inline bool is_stw_gc_in_progress() const;
306 inline bool is_concurrent_root_in_progress() const;
307
308 // ---------- GC cancellation and degeneration machinery
309 //
310 // Cancelled GC flag is used to notify concurrent phases that they should terminate.
311 //
312 public:
313 enum ShenandoahDegenPoint {
314 _degenerated_unset,
315 _degenerated_traversal,
316 _degenerated_outside_cycle,
317 _degenerated_mark,
318 _degenerated_evac,
319 _degenerated_updaterefs,
320 _DEGENERATED_LIMIT
321 };
322
323 static const char* degen_point_to_string(ShenandoahDegenPoint point) {
324 switch (point) {
325 case _degenerated_unset:
326 return "<UNSET>";
327 case _degenerated_traversal:
328 return "Traversal";
329 case _degenerated_outside_cycle:
330 return "Outside of Cycle";
331 case _degenerated_mark:
332 return "Mark";
333 case _degenerated_evac:
334 return "Evacuation";
335 case _degenerated_updaterefs:
336 return "Update Refs";
337 default:
338 ShouldNotReachHere();
339 return "ERROR";
340 }
341 };
342
343 private:
344 enum CancelState {
345 // Normal state. GC has not been cancelled and is open for cancellation.
346 // Worker threads can suspend for safepoint.
347 CANCELLABLE,
348
349 // GC has been cancelled. Worker threads can not suspend for
350 // safepoint but must finish their work as soon as possible.
351 CANCELLED,
352
353 // GC has not been cancelled and must not be cancelled. At least
354 // one worker thread checks for pending safepoint and may suspend
355 // if a safepoint is pending.
356 NOT_CANCELLED
357 };
358
359 ShenandoahSharedEnumFlag<CancelState> _cancelled_gc;
360 bool try_cancel_gc();
361
362 public:
363 static address cancelled_gc_addr();
364
365 inline bool cancelled_gc() const;
366 inline bool check_cancelled_gc_and_yield(bool sts_active = true);
367
368 inline void clear_cancelled_gc();
369
370 void cancel_gc(GCCause::Cause cause);
371
372 // ---------- GC operations entry points
373 //
374 public:
375 // Entry points to STW GC operations, these cause a related safepoint, that then
376 // call the entry method below
377 void vmop_entry_init_mark();
378 void vmop_entry_final_mark();
379 void vmop_entry_final_evac();
380 void vmop_entry_init_updaterefs();
381 void vmop_entry_final_updaterefs();
382 void vmop_entry_init_traversal();
383 void vmop_entry_final_traversal();
384 void vmop_entry_full(GCCause::Cause cause);
385 void vmop_degenerated(ShenandoahDegenPoint point);
386
387 // Entry methods to normally STW GC operations. These set up logging, monitoring
388 // and workers for net VM operation
389 void entry_init_mark();
390 void entry_final_mark();
391 void entry_final_evac();
392 void entry_init_updaterefs();
393 void entry_final_updaterefs();
394 void entry_init_traversal();
395 void entry_final_traversal();
396 void entry_full(GCCause::Cause cause);
397 void entry_degenerated(int point);
398
399 // Entry methods to normally concurrent GC operations. These set up logging, monitoring
400 // for concurrent operation.
401 void entry_reset();
402 void entry_mark();
403 void entry_preclean();
404 void entry_roots();
405 void entry_cleanup();
406 void entry_evac();
407 void entry_updaterefs();
408 void entry_traversal();
409 void entry_uncommit(double shrink_before);
410
411 private:
412 // Actual work for the phases
413 void op_init_mark();
414 void op_final_mark();
415 void op_final_evac();
416 void op_init_updaterefs();
417 void op_final_updaterefs();
418 void op_init_traversal();
419 void op_final_traversal();
420 void op_full(GCCause::Cause cause);
421 void op_degenerated(ShenandoahDegenPoint point);
422 void op_degenerated_fail();
423 void op_degenerated_futile();
424
425 void op_reset();
426 void op_mark();
427 void op_preclean();
428 void op_roots();
429 void op_cleanup();
430 void op_conc_evac();
431 void op_stw_evac();
432 void op_updaterefs();
433 void op_traversal();
434 void op_uncommit(double shrink_before);
435
436 // Messages for GC trace events, they have to be immortal for
437 // passing around the logging/tracing systems
438 const char* init_mark_event_message() const;
439 const char* final_mark_event_message() const;
440 const char* conc_mark_event_message() const;
441 const char* init_traversal_event_message() const;
442 const char* final_traversal_event_message() const;
443 const char* conc_traversal_event_message() const;
444 const char* degen_event_message(ShenandoahDegenPoint point) const;
445
446 // ---------- GC subsystems
447 //
448 private:
449 ShenandoahControlThread* _control_thread;
450 ShenandoahCollectorPolicy* _shenandoah_policy;
451 ShenandoahMode* _gc_mode;
452 ShenandoahHeuristics* _heuristics;
453 ShenandoahFreeSet* _free_set;
454 ShenandoahConcurrentMark* _scm;
455 ShenandoahTraversalGC* _traversal_gc;
456 ShenandoahMarkCompact* _full_gc;
457 ShenandoahPacer* _pacer;
458 ShenandoahVerifier* _verifier;
459
460 ShenandoahAllocTracker* _alloc_tracker;
461 ShenandoahPhaseTimings* _phase_timings;
462
463 ShenandoahControlThread* control_thread() { return _control_thread; }
464 ShenandoahMarkCompact* full_gc() { return _full_gc; }
465
466 public:
467 ShenandoahCollectorPolicy* shenandoah_policy() const { return _shenandoah_policy; }
468 ShenandoahHeuristics* heuristics() const { return _heuristics; }
469 ShenandoahFreeSet* free_set() const { return _free_set; }
470 ShenandoahConcurrentMark* concurrent_mark() { return _scm; }
471 ShenandoahTraversalGC* traversal_gc() const { return _traversal_gc; }
472 bool is_traversal_mode() const { return _traversal_gc != NULL; }
473 ShenandoahPacer* pacer() const { return _pacer; }
474
475 ShenandoahPhaseTimings* phase_timings() const { return _phase_timings; }
476 ShenandoahAllocTracker* alloc_tracker() const { return _alloc_tracker; }
477
478 ShenandoahVerifier* verifier();
479
480 // ---------- VM subsystem bindings
481 //
482 private:
483 ShenandoahMonitoringSupport* _monitoring_support;
484 MemoryPool* _memory_pool;
485 GCMemoryManager _stw_memory_manager;
486 GCMemoryManager _cycle_memory_manager;
487 ConcurrentGCTimer* _gc_timer;
488 SoftRefPolicy _soft_ref_policy;
489
490 // For exporting to SA
491 int _log_min_obj_alignment_in_bytes;
492 public:
493 ShenandoahMonitoringSupport* monitoring_support() { return _monitoring_support; }
494 GCMemoryManager* cycle_memory_manager() { return &_cycle_memory_manager; }
495 GCMemoryManager* stw_memory_manager() { return &_stw_memory_manager; }
496 SoftRefPolicy* soft_ref_policy() { return &_soft_ref_policy; }
497
498 GrowableArray<GCMemoryManager*> memory_managers();
499 GrowableArray<MemoryPool*> memory_pools();
500 MemoryUsage memory_usage();
501 GCTracer* tracer();
502 GCTimer* gc_timer() const;
503
504 // ---------- Reference processing
505 //
506 private:
507 AlwaysTrueClosure _subject_to_discovery;
508 ReferenceProcessor* _ref_processor;
509 ShenandoahSharedFlag _process_references;
510
511 void ref_processing_init();
512
513 public:
514 ReferenceProcessor* ref_processor() { return _ref_processor; }
515 void set_process_references(bool pr);
516 bool process_references() const;
517
518 // ---------- Class Unloading
519 //
520 private:
521 ShenandoahSharedFlag _unload_classes;
522 ShenandoahUnload _unloader;
523
524 public:
525 void set_unload_classes(bool uc);
526 bool unload_classes() const;
527
528 // Perform STW class unloading and weak root cleaning
529 void parallel_cleaning(bool full_gc);
530
531 private:
532 void stw_unload_classes(bool full_gc);
533 void stw_process_weak_roots(bool full_gc);
534
535 // Prepare concurrent root processing
536 void prepare_concurrent_roots();
537 // Prepare and finish concurrent unloading
538 void prepare_concurrent_unloading();
539 void finish_concurrent_unloading();
540
541 // ---------- Generic interface hooks
542 // Minor things that super-interface expects us to implement to play nice with
543 // the rest of runtime. Some of the things here are not required to be implemented,
544 // and can be stubbed out.
545 //
546 public:
547 AdaptiveSizePolicy* size_policy() shenandoah_not_implemented_return(NULL);
548 bool is_maximal_no_gc() const shenandoah_not_implemented_return(false);
549
550 bool is_in(const void* p) const;
551
552 MemRegion reserved_region() const { return _reserved; }
553 bool is_in_reserved(const void* addr) const { return _reserved.contains(addr); }
554
555 void collect(GCCause::Cause cause);
556 void do_full_collection(bool clear_all_soft_refs);
557
558 // Used for parsing heap during error printing
559 HeapWord* block_start(const void* addr) const;
560 bool block_is_obj(const HeapWord* addr) const;
561 bool print_location(outputStream* st, void* addr) const;
562
563 // Used for native heap walkers: heap dumpers, mostly
564 void object_iterate(ObjectClosure* cl);
565
566 // Keep alive an object that was loaded with AS_NO_KEEPALIVE.
567 void keep_alive(oop obj);
568
569 // Used by RMI
570 jlong millis_since_last_gc();
571
572 // ---------- Safepoint interface hooks
573 //
574 public:
575 void safepoint_synchronize_begin();
576 void safepoint_synchronize_end();
577
578 // ---------- Code roots handling hooks
579 //
580 public:
581 void register_nmethod(nmethod* nm);
582 void unregister_nmethod(nmethod* nm);
583 void flush_nmethod(nmethod* nm);
584 void verify_nmethod(nmethod* nm) {}
585
586 // ---------- Pinning hooks
587 //
588 public:
589 // Shenandoah supports per-object (per-region) pinning
590 bool supports_object_pinning() const { return true; }
591
592 oop pin_object(JavaThread* thread, oop obj);
593 void unpin_object(JavaThread* thread, oop obj);
594
595 void sync_pinned_region_status();
596 void assert_pinned_region_status() NOT_DEBUG_RETURN;
597
598 // ---------- Allocation support
599 //
600 private:
601 HeapWord* allocate_memory_under_lock(ShenandoahAllocRequest& request, bool& in_new_region);
602 inline HeapWord* allocate_from_gclab(Thread* thread, size_t size);
603 HeapWord* allocate_from_gclab_slow(Thread* thread, size_t size);
604 HeapWord* allocate_new_gclab(size_t min_size, size_t word_size, size_t* actual_size);
605 void retire_and_reset_gclabs();
606
607 public:
608 HeapWord* allocate_memory(ShenandoahAllocRequest& request);
609 HeapWord* mem_allocate(size_t size, bool* what);
610 MetaWord* satisfy_failed_metadata_allocation(ClassLoaderData* loader_data,
611 size_t size,
612 Metaspace::MetadataType mdtype);
613
614 void notify_mutator_alloc_words(size_t words, bool waste);
615
616 // Shenandoah supports TLAB allocation
617 bool supports_tlab_allocation() const { return true; }
618
619 HeapWord* allocate_new_tlab(size_t min_size, size_t requested_size, size_t* actual_size);
620 size_t tlab_capacity(Thread *thr) const;
621 size_t unsafe_max_tlab_alloc(Thread *thread) const;
622 size_t max_tlab_size() const;
623 size_t tlab_used(Thread* ignored) const;
624
625 void resize_tlabs();
626
627 void ensure_parsability(bool retire_tlabs);
628 void make_parsable(bool retire_tlabs);
629
630 // ---------- Marking support
631 //
632 private:
633 ShenandoahMarkingContext* _marking_context;
634 MemRegion _bitmap_region;
635 MemRegion _aux_bitmap_region;
636 MarkBitMap _verification_bit_map;
637 MarkBitMap _aux_bit_map;
638
639 size_t _bitmap_size;
640 size_t _bitmap_regions_per_slice;
641 size_t _bitmap_bytes_per_slice;
642
643 bool _bitmap_region_special;
644 bool _aux_bitmap_region_special;
645
646 // Used for buffering per-region liveness data.
647 // Needed since ShenandoahHeapRegion uses atomics to update liveness.
648 //
649 // The array has max-workers elements, each of which is an array of
650 // jushort * max_regions. The choice of jushort is not accidental:
651 // there is a tradeoff between static/dynamic footprint that translates
652 // into cache pressure (which is already high during marking), and
653 // too many atomic updates. size_t/jint is too large, jbyte is too small.
654 jushort** _liveness_cache;
655
656 public:
657 inline ShenandoahMarkingContext* complete_marking_context() const;
658 inline ShenandoahMarkingContext* marking_context() const;
659 inline void mark_complete_marking_context();
660 inline void mark_incomplete_marking_context();
661
662 template<class T>
663 inline void marked_object_iterate(ShenandoahHeapRegion* region, T* cl);
664
665 template<class T>
666 inline void marked_object_iterate(ShenandoahHeapRegion* region, T* cl, HeapWord* limit);
667
668 template<class T>
669 inline void marked_object_oop_iterate(ShenandoahHeapRegion* region, T* cl, HeapWord* limit);
670
671 void reset_mark_bitmap();
672
673 // SATB barriers hooks
674 template<bool RESOLVE>
675 inline bool requires_marking(const void* entry) const;
676 void force_satb_flush_all_threads();
677
678 // Support for bitmap uncommits
679 bool commit_bitmap_slice(ShenandoahHeapRegion *r);
680 bool uncommit_bitmap_slice(ShenandoahHeapRegion *r);
681 bool is_bitmap_slice_committed(ShenandoahHeapRegion* r, bool skip_self = false);
682
683 // Liveness caching support
684 jushort* get_liveness_cache(uint worker_id);
685 void flush_liveness_cache(uint worker_id);
686
687 // ---------- Evacuation support
688 //
689 private:
690 ShenandoahCollectionSet* _collection_set;
691 ShenandoahEvacOOMHandler _oom_evac_handler;
692
693 void evacuate_and_update_roots();
694
695 public:
696 static address in_cset_fast_test_addr();
697
698 ShenandoahCollectionSet* collection_set() const { return _collection_set; }
699
700 template <class T>
701 inline bool in_collection_set(T obj) const;
702
703 // Avoid accidentally calling the method above with ShenandoahHeapRegion*, which would be *wrong*.
704 inline bool in_collection_set(ShenandoahHeapRegion* r) shenandoah_not_implemented_return(false);
705
706 // Evacuates object src. Returns the evacuated object, either evacuated
707 // by this thread, or by some other thread.
708 inline oop evacuate_object(oop src, Thread* thread);
709
710 // Call before/after evacuation.
711 void enter_evacuation();
712 void leave_evacuation();
713
714 // ---------- Helper functions
715 //
716 public:
717 template <class T>
718 inline oop evac_update_with_forwarded(T* p);
719
720 template <class T>
721 inline oop maybe_update_with_forwarded(T* p);
722
723 template <class T>
724 inline oop maybe_update_with_forwarded_not_null(T* p, oop obj);
725
726 template <class T>
727 inline oop update_with_forwarded_not_null(T* p, oop obj);
728
729 static inline oop cas_oop(oop n, narrowOop* addr, oop c);
730 static inline oop cas_oop(oop n, oop* addr, oop c);
731 static inline oop cas_oop(oop n, narrowOop* addr, narrowOop c);
732
733 void trash_humongous_region_at(ShenandoahHeapRegion *r);
734
735 void deduplicate_string(oop str);
736
737 private:
738 void trash_cset_regions();
739 void update_heap_references(bool concurrent);
740
741 // ---------- Testing helpers functions
742 //
743 private:
744 ShenandoahSharedFlag _inject_alloc_failure;
745
746 void try_inject_alloc_failure();
747 bool should_inject_alloc_failure();
748 };
749
750 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHHEAP_HPP