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