1 /*
  2  * Copyright (c) 2023, Oracle and/or its affiliates. All rights reserved.
  3  * Copyright (c) 2013, 2021, Red Hat, Inc. All rights reserved.

  4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  5  *
  6  * This code is free software; you can redistribute it and/or modify it
  7  * under the terms of the GNU General Public License version 2 only, as
  8  * published by the Free Software Foundation.
  9  *
 10  * This code is distributed in the hope that it will be useful, but WITHOUT
 11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 13  * version 2 for more details (a copy is included in the LICENSE file that
 14  * accompanied this code).
 15  *
 16  * You should have received a copy of the GNU General Public License version
 17  * 2 along with this work; if not, write to the Free Software Foundation,
 18  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 19  *
 20  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 21  * or visit www.oracle.com if you need additional information or have any
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 25 
 26 #ifndef SHARE_GC_SHENANDOAH_SHENANDOAHHEAP_HPP
 27 #define SHARE_GC_SHENANDOAH_SHENANDOAHHEAP_HPP
 28 

 29 #include "gc/shared/markBitMap.hpp"
 30 #include "gc/shared/softRefPolicy.hpp"
 31 #include "gc/shared/collectedHeap.hpp"


 32 #include "gc/shenandoah/shenandoahAsserts.hpp"
 33 #include "gc/shenandoah/shenandoahAllocRequest.hpp"


 34 #include "gc/shenandoah/shenandoahLock.hpp"
 35 #include "gc/shenandoah/shenandoahEvacOOMHandler.hpp"



 36 #include "gc/shenandoah/shenandoahPadding.hpp"

 37 #include "gc/shenandoah/shenandoahSharedVariables.hpp"
 38 #include "gc/shenandoah/shenandoahUnload.hpp"
 39 #include "memory/metaspace.hpp"
 40 #include "services/memoryManager.hpp"
 41 #include "utilities/globalDefinitions.hpp"
 42 #include "utilities/stack.hpp"
 43 
 44 class ConcurrentGCTimer;
 45 class ObjectIterateScanRootClosure;

 46 class ShenandoahCollectorPolicy;
 47 class ShenandoahControlThread;
 48 class ShenandoahGCSession;
 49 class ShenandoahGCStateResetter;



 50 class ShenandoahHeuristics;


 51 class ShenandoahMarkingContext;
 52 class ShenandoahMode;
 53 class ShenandoahPhaseTimings;
 54 class ShenandoahHeap;
 55 class ShenandoahHeapRegion;
 56 class ShenandoahHeapRegionClosure;
 57 class ShenandoahCollectionSet;
 58 class ShenandoahFreeSet;
 59 class ShenandoahConcurrentMark;
 60 class ShenandoahFullGC;
 61 class ShenandoahMonitoringSupport;

 62 class ShenandoahPacer;
 63 class ShenandoahReferenceProcessor;
 64 class ShenandoahVerifier;
 65 class ShenandoahWorkerThreads;
 66 class VMStructs;
 67 
 68 // Used for buffering per-region liveness data.
 69 // Needed since ShenandoahHeapRegion uses atomics to update liveness.
 70 // The ShenandoahHeap array has max-workers elements, each of which is an array of
 71 // uint16_t * max_regions. The choice of uint16_t is not accidental:
 72 // there is a tradeoff between static/dynamic footprint that translates
 73 // into cache pressure (which is already high during marking), and
 74 // too many atomic updates. uint32_t is too large, uint8_t is too small.
 75 typedef uint16_t ShenandoahLiveData;
 76 #define SHENANDOAH_LIVEDATA_MAX ((ShenandoahLiveData)-1)
 77 
 78 class ShenandoahRegionIterator : public StackObj {
 79 private:
 80   ShenandoahHeap* _heap;
 81 
 82   shenandoah_padding(0);
 83   volatile size_t _index;
 84   shenandoah_padding(1);
 85 
 86   // No implicit copying: iterators should be passed by reference to capture the state
 87   NONCOPYABLE(ShenandoahRegionIterator);
 88 
 89 public:
 90   ShenandoahRegionIterator();
 91   ShenandoahRegionIterator(ShenandoahHeap* heap);
 92 
 93   // Reset iterator to default state
 94   void reset();
 95 
 96   // Returns next region, or null if there are no more regions.
 97   // This is multi-thread-safe.
 98   inline ShenandoahHeapRegion* next();
 99 
100   // This is *not* MT safe. However, in the absence of multithreaded access, it
101   // can be used to determine if there is more work to do.
102   bool has_next() const;
103 };
104 
105 class ShenandoahHeapRegionClosure : public StackObj {
106 public:
107   virtual void heap_region_do(ShenandoahHeapRegion* r) = 0;
108   virtual bool is_thread_safe() { return false; }
109 };
110 










111 typedef ShenandoahLock    ShenandoahHeapLock;
112 typedef ShenandoahLocker  ShenandoahHeapLocker;
113 typedef Stack<oop, mtGC>  ShenandoahScanObjectStack;
114 
115 // Shenandoah GC is low-pause concurrent GC that uses Brooks forwarding pointers
116 // to encode forwarding data. See BrooksPointer for details on forwarding data encoding.
117 // See ShenandoahControlThread for GC cycle structure.
118 //
119 class ShenandoahHeap : public CollectedHeap {
120   friend class ShenandoahAsserts;
121   friend class VMStructs;
122   friend class ShenandoahGCSession;
123   friend class ShenandoahGCStateResetter;
124   friend class ShenandoahParallelObjectIterator;
125   friend class ShenandoahSafepoint;

126   // Supported GC
127   friend class ShenandoahConcurrentGC;

128   friend class ShenandoahDegenGC;
129   friend class ShenandoahFullGC;
130   friend class ShenandoahUnload;
131 
132 // ---------- Locks that guard important data structures in Heap
133 //
134 private:
135   ShenandoahHeapLock _lock;

136 
137 public:
138   ShenandoahHeapLock* lock() {
139     return &_lock;
140   }
141 

















142 // ---------- Initialization, termination, identification, printing routines
143 //
144 public:
145   static ShenandoahHeap* heap();
146 
147   const char* name()          const override { return "Shenandoah"; }
148   ShenandoahHeap::Name kind() const override { return CollectedHeap::Shenandoah; }
149 
150   ShenandoahHeap(ShenandoahCollectorPolicy* policy);
151   jint initialize() override;
152   void post_initialize() override;
153   void initialize_mode();
154   void initialize_heuristics();
155 
156   void initialize_serviceability() override;
157 
158   void print_on(outputStream* st)              const override;
159   void print_extended_on(outputStream *st)     const override;
160   void print_tracing_info()                    const override;
161   void print_heap_regions_on(outputStream* st) const;
162 
163   void stop() override;
164 
165   void prepare_for_verify() override;
166   void verify(VerifyOption vo) override;
167 



168 // WhiteBox testing support.
169   bool supports_concurrent_gc_breakpoints() const override {
170     return true;
171   }
172 
173 // ---------- Heap counters and metrics
174 //
175 private:
176            size_t _initial_size;
177            size_t _minimum_size;

178   volatile size_t _soft_max_size;
179   shenandoah_padding(0);
180   volatile size_t _used;
181   volatile size_t _committed;
182   volatile size_t _bytes_allocated_since_gc_start;
183   shenandoah_padding(1);
184 


185 public:
186   void increase_used(size_t bytes);
187   void decrease_used(size_t bytes);
188   void set_used(size_t bytes);

189 
190   void increase_committed(size_t bytes);
191   void decrease_committed(size_t bytes);
192   void increase_allocated(size_t bytes);
193 
194   size_t bytes_allocated_since_gc_start();
195   void reset_bytes_allocated_since_gc_start();
196 
197   size_t min_capacity()      const;
198   size_t max_capacity()      const override;
199   size_t soft_max_capacity() const;
200   size_t initial_capacity()  const;
201   size_t capacity()          const override;
202   size_t used()              const override;
203   size_t committed()         const;
204 
205   void set_soft_max_capacity(size_t v);
206 









207 // ---------- Workers handling
208 //
209 private:
210   uint _max_workers;
211   ShenandoahWorkerThreads* _workers;
212   ShenandoahWorkerThreads* _safepoint_workers;
213 


214 public:
215   uint max_workers();
216   void assert_gc_workers(uint nworker) NOT_DEBUG_RETURN;
217 
218   WorkerThreads* workers() const;
219   WorkerThreads* safepoint_workers() override;
220 
221   void gc_threads_do(ThreadClosure* tcl) const override;
222 
223 // ---------- Heap regions handling machinery
224 //
225 private:
226   MemRegion _heap_region;
227   bool      _heap_region_special;
228   size_t    _num_regions;
229   ShenandoahHeapRegion** _regions;

230   ShenandoahRegionIterator _update_refs_iterator;
231 
232 public:
233 
234   inline HeapWord* base() const { return _heap_region.start(); }
235 
236   inline size_t num_regions() const { return _num_regions; }
237   inline bool is_heap_region_special() { return _heap_region_special; }
238 
239   inline ShenandoahHeapRegion* const heap_region_containing(const void* addr) const;
240   inline size_t heap_region_index_containing(const void* addr) const;
241 
242   inline ShenandoahHeapRegion* const get_region(size_t region_idx) const;
243 
244   void heap_region_iterate(ShenandoahHeapRegionClosure* blk) const;
245   void parallel_heap_region_iterate(ShenandoahHeapRegionClosure* blk) const;
246 


247 // ---------- GC state machinery
248 //
249 // GC state describes the important parts of collector state, that may be
250 // used to make barrier selection decisions in the native and generated code.
251 // Multiple bits can be set at once.
252 //
253 // Important invariant: when GC state is zero, the heap is stable, and no barriers
254 // are required.
255 //
256 public:
257   enum GCStateBitPos {
258     // Heap has forwarded objects: needs LRB barriers.
259     HAS_FORWARDED_BITPOS   = 0,
260 
261     // Heap is under marking: needs SATB barriers.

262     MARKING_BITPOS    = 1,
263 
264     // Heap is under evacuation: needs LRB barriers. (Set together with HAS_FORWARDED)
265     EVACUATION_BITPOS = 2,
266 
267     // Heap is under updating: needs no additional barriers.
268     UPDATEREFS_BITPOS = 3,
269 
270     // Heap is under weak-reference/roots processing: needs weak-LRB barriers.
271     WEAK_ROOTS_BITPOS  = 4,






272   };
273 
274   enum GCState {
275     STABLE        = 0,
276     HAS_FORWARDED = 1 << HAS_FORWARDED_BITPOS,
277     MARKING       = 1 << MARKING_BITPOS,
278     EVACUATION    = 1 << EVACUATION_BITPOS,
279     UPDATEREFS    = 1 << UPDATEREFS_BITPOS,
280     WEAK_ROOTS    = 1 << WEAK_ROOTS_BITPOS,


281   };
282 
283 private:

284   ShenandoahSharedBitmap _gc_state;

285   ShenandoahSharedFlag   _degenerated_gc_in_progress;
286   ShenandoahSharedFlag   _full_gc_in_progress;
287   ShenandoahSharedFlag   _full_gc_move_in_progress;
288   ShenandoahSharedFlag   _progress_last_gc;
289   ShenandoahSharedFlag   _concurrent_strong_root_in_progress;
290 
291   void set_gc_state_all_threads(char state);
292   void set_gc_state_mask(uint mask, bool value);




293 
294 public:
295   char gc_state() const;
296 
297   void set_concurrent_mark_in_progress(bool in_progress);















298   void set_evacuation_in_progress(bool in_progress);
299   void set_update_refs_in_progress(bool in_progress);
300   void set_degenerated_gc_in_progress(bool in_progress);
301   void set_full_gc_in_progress(bool in_progress);
302   void set_full_gc_move_in_progress(bool in_progress);
303   void set_has_forwarded_objects(bool cond);
304   void set_concurrent_strong_root_in_progress(bool cond);
305   void set_concurrent_weak_root_in_progress(bool cond);
306 


307   inline bool is_stable() const;
308   inline bool is_idle() const;

309   inline bool is_concurrent_mark_in_progress() const;


310   inline bool is_update_refs_in_progress() const;
311   inline bool is_evacuation_in_progress() const;
312   inline bool is_degenerated_gc_in_progress() const;
313   inline bool is_full_gc_in_progress() const;
314   inline bool is_full_gc_move_in_progress() const;
315   inline bool has_forwarded_objects() const;
316 
317   inline bool is_stw_gc_in_progress() const;
318   inline bool is_concurrent_strong_root_in_progress() const;
319   inline bool is_concurrent_weak_root_in_progress() const;





320 
321 private:


322   enum CancelState {
323     // Normal state. GC has not been cancelled and is open for cancellation.
324     // Worker threads can suspend for safepoint.
325     CANCELLABLE,
326 
327     // GC has been cancelled. Worker threads can not suspend for
328     // safepoint but must finish their work as soon as possible.
329     CANCELLED
330   };
331 

332   ShenandoahSharedEnumFlag<CancelState> _cancelled_gc;





333   bool try_cancel_gc();
334 
335 public:
336 
337   inline bool cancelled_gc() const;
338   inline bool check_cancelled_gc_and_yield(bool sts_active = true);
339 
340   inline void clear_cancelled_gc();
341 

342   void cancel_gc(GCCause::Cause cause);
343 
344 public:
345   // Elastic heap support
346   void entry_uncommit(double shrink_before, size_t shrink_until);

347   void op_uncommit(double shrink_before, size_t shrink_until);
348 



349 private:
350   // GC support
351   // Reset bitmap, prepare regions for new GC cycle
352   void prepare_gc();
353   void prepare_regions_and_collection_set(bool concurrent);
354   // Evacuation
355   void evacuate_collection_set(bool concurrent);
356   // Concurrent root processing
357   void prepare_concurrent_roots();
358   void finish_concurrent_roots();
359   // Concurrent class unloading support
360   void do_class_unloading();
361   // Reference updating
362   void prepare_update_heap_references(bool concurrent);
363   void update_heap_references(bool concurrent);
364   // Final update region states
365   void update_heap_region_states(bool concurrent);
366   void rebuild_free_set(bool concurrent);
367 
368   void rendezvous_threads();
369   void recycle_trash();
370 public:
371   void notify_gc_progress()    { _progress_last_gc.set();   }
372   void notify_gc_no_progress() { _progress_last_gc.unset(); }


373 
374 //
375 // Mark support
376 private:
377   ShenandoahControlThread*   _control_thread;







378   ShenandoahCollectorPolicy* _shenandoah_policy;
379   ShenandoahMode*            _gc_mode;
380   ShenandoahHeuristics*      _heuristics;
381   ShenandoahFreeSet*         _free_set;
382   ShenandoahPacer*           _pacer;
383   ShenandoahVerifier*        _verifier;
384 
385   ShenandoahPhaseTimings*    _phase_timings;
386 
387   ShenandoahControlThread*   control_thread()          { return _control_thread;    }

388 
389 public:








390   ShenandoahCollectorPolicy* shenandoah_policy() const { return _shenandoah_policy; }
391   ShenandoahMode*            mode()              const { return _gc_mode;           }
392   ShenandoahHeuristics*      heuristics()        const { return _heuristics;        }
393   ShenandoahFreeSet*         free_set()          const { return _free_set;          }
394   ShenandoahPacer*           pacer()             const { return _pacer;             }
395 
396   ShenandoahPhaseTimings*    phase_timings()     const { return _phase_timings;     }




397 
398   ShenandoahVerifier*        verifier();
399 
400 // ---------- VM subsystem bindings
401 //
402 private:
403   ShenandoahMonitoringSupport* _monitoring_support;
404   MemoryPool*                  _memory_pool;
405   GCMemoryManager              _stw_memory_manager;
406   GCMemoryManager              _cycle_memory_manager;
407   ConcurrentGCTimer*           _gc_timer;
408   SoftRefPolicy                _soft_ref_policy;
409 
410   // For exporting to SA
411   int                          _log_min_obj_alignment_in_bytes;
412 public:
413   ShenandoahMonitoringSupport* monitoring_support()          { return _monitoring_support;    }
414   GCMemoryManager* cycle_memory_manager()                    { return &_cycle_memory_manager; }
415   GCMemoryManager* stw_memory_manager()                      { return &_stw_memory_manager;   }
416   SoftRefPolicy* soft_ref_policy()                  override { return &_soft_ref_policy;      }
417 
418   GrowableArray<GCMemoryManager*> memory_managers() override;
419   GrowableArray<MemoryPool*> memory_pools() override;
420   MemoryUsage memory_usage() override;
421   GCTracer* tracer();
422   ConcurrentGCTimer* gc_timer() const;
423 
424 // ---------- Reference processing
425 //
426 private:
427   ShenandoahReferenceProcessor* const _ref_processor;
428 
429 public:
430   ShenandoahReferenceProcessor* ref_processor() { return _ref_processor; }
431 
432 // ---------- Class Unloading
433 //
434 private:

435   ShenandoahSharedFlag _unload_classes;
436   ShenandoahUnload     _unloader;
437 
438 public:
439   void set_unload_classes(bool uc);
440   bool unload_classes() const;
441 
442   // Perform STW class unloading and weak root cleaning
443   void parallel_cleaning(bool full_gc);
444 
445 private:
446   void stw_unload_classes(bool full_gc);
447   void stw_process_weak_roots(bool full_gc);
448   void stw_weak_refs(bool full_gc);
449 



450   // Heap iteration support
451   void scan_roots_for_iteration(ShenandoahScanObjectStack* oop_stack, ObjectIterateScanRootClosure* oops);
452   bool prepare_aux_bitmap_for_iteration();
453   void reclaim_aux_bitmap_for_iteration();
454 
455 // ---------- Generic interface hooks
456 // Minor things that super-interface expects us to implement to play nice with
457 // the rest of runtime. Some of the things here are not required to be implemented,
458 // and can be stubbed out.
459 //
460 public:
461   bool is_maximal_no_gc() const override shenandoah_not_implemented_return(false);
462 
463   bool is_in(const void* p) const override;










464 
465   bool requires_barriers(stackChunkOop obj) const override;
466 
467   MemRegion reserved_region() const { return _reserved; }
468   bool is_in_reserved(const void* addr) const { return _reserved.contains(addr); }
469 
470   void collect(GCCause::Cause cause) override;
471   void do_full_collection(bool clear_all_soft_refs) override;
472 
473   // Used for parsing heap during error printing
474   HeapWord* block_start(const void* addr) const;
475   bool block_is_obj(const HeapWord* addr) const;
476   bool print_location(outputStream* st, void* addr) const override;
477 
478   // Used for native heap walkers: heap dumpers, mostly
479   void object_iterate(ObjectClosure* cl) override;
480   // Parallel heap iteration support
481   ParallelObjectIteratorImpl* parallel_object_iterator(uint workers) override;
482 
483   // Keep alive an object that was loaded with AS_NO_KEEPALIVE.
484   void keep_alive(oop obj) override;
485 
486 // ---------- Safepoint interface hooks
487 //
488 public:
489   void safepoint_synchronize_begin() override;
490   void safepoint_synchronize_end() override;
491 
492 // ---------- Code roots handling hooks
493 //
494 public:
495   void register_nmethod(nmethod* nm) override;
496   void unregister_nmethod(nmethod* nm) override;
497   void verify_nmethod(nmethod* nm) override {}
498 
499 // ---------- Pinning hooks
500 //
501 public:
502   // Shenandoah supports per-object (per-region) pinning
503   void pin_object(JavaThread* thread, oop obj) override;
504   void unpin_object(JavaThread* thread, oop obj) override;
505 
506   void sync_pinned_region_status();
507   void assert_pinned_region_status() NOT_DEBUG_RETURN;
508 
509 // ---------- Concurrent Stack Processing support
510 //
511 public:
512   bool uses_stack_watermark_barrier() const override { return true; }
513 
514 // ---------- Allocation support
515 //
516 private:
517   HeapWord* allocate_memory_under_lock(ShenandoahAllocRequest& request, bool& in_new_region);

518   inline HeapWord* allocate_from_gclab(Thread* thread, size_t size);
519   HeapWord* allocate_from_gclab_slow(Thread* thread, size_t size);
520   HeapWord* allocate_new_gclab(size_t min_size, size_t word_size, size_t* actual_size);
521 




522 public:
523   HeapWord* allocate_memory(ShenandoahAllocRequest& request);
524   HeapWord* mem_allocate(size_t size, bool* what) override;
525   MetaWord* satisfy_failed_metadata_allocation(ClassLoaderData* loader_data,
526                                                size_t size,
527                                                Metaspace::MetadataType mdtype) override;
528 
529   void notify_mutator_alloc_words(size_t words, bool waste);
530 
531   HeapWord* allocate_new_tlab(size_t min_size, size_t requested_size, size_t* actual_size) override;
532   size_t tlab_capacity(Thread *thr) const override;
533   size_t unsafe_max_tlab_alloc(Thread *thread) const override;
534   size_t max_tlab_size() const override;
535   size_t tlab_used(Thread* ignored) const override;
536 
537   void ensure_parsability(bool retire_labs) override;
538 
539   void labs_make_parsable();
540   void tlabs_retire(bool resize);
541   void gclabs_retire(bool resize);
542 
543 // ---------- Marking support
544 //
545 private:
546   ShenandoahMarkingContext* _marking_context;
547   MemRegion  _bitmap_region;
548   MemRegion  _aux_bitmap_region;
549   MarkBitMap _verification_bit_map;
550   MarkBitMap _aux_bit_map;
551 
552   size_t _bitmap_size;
553   size_t _bitmap_regions_per_slice;
554   size_t _bitmap_bytes_per_slice;
555 
556   size_t _pretouch_heap_page_size;
557   size_t _pretouch_bitmap_page_size;
558 
559   bool _bitmap_region_special;
560   bool _aux_bitmap_region_special;
561 
562   ShenandoahLiveData** _liveness_cache;
563 
564 public:
565   inline ShenandoahMarkingContext* complete_marking_context() const;
566   inline ShenandoahMarkingContext* marking_context() const;
567   inline void mark_complete_marking_context();
568   inline void mark_incomplete_marking_context();
569 
570   template<class T>
571   inline void marked_object_iterate(ShenandoahHeapRegion* region, T* cl);
572 
573   template<class T>
574   inline void marked_object_iterate(ShenandoahHeapRegion* region, T* cl, HeapWord* limit);
575 
576   template<class T>
577   inline void marked_object_oop_iterate(ShenandoahHeapRegion* region, T* cl, HeapWord* limit);
578 
579   void reset_mark_bitmap();
580 
581   // SATB barriers hooks
582   inline bool requires_marking(const void* entry) const;
583 
584   // Support for bitmap uncommits
585   bool commit_bitmap_slice(ShenandoahHeapRegion *r);
586   bool uncommit_bitmap_slice(ShenandoahHeapRegion *r);
587   bool is_bitmap_slice_committed(ShenandoahHeapRegion* r, bool skip_self = false);
588 
589   // Liveness caching support
590   ShenandoahLiveData* get_liveness_cache(uint worker_id);
591   void flush_liveness_cache(uint worker_id);
592 
593   size_t pretouch_heap_page_size() { return _pretouch_heap_page_size; }
594 
595 // ---------- Evacuation support
596 //
597 private:
598   ShenandoahCollectionSet* _collection_set;
599   ShenandoahEvacOOMHandler _oom_evac_handler;
600 

601 public:

602   static address in_cset_fast_test_addr();
603 
604   ShenandoahCollectionSet* collection_set() const { return _collection_set; }
605 
606   // Checks if object is in the collection set.
607   inline bool in_collection_set(oop obj) const;
608 
609   // Checks if location is in the collection set. Can be interior pointer, not the oop itself.
610   inline bool in_collection_set_loc(void* loc) const;
611 
612   // Evacuates object src. Returns the evacuated object, either evacuated
613   // by this thread, or by some other thread.
614   inline oop evacuate_object(oop src, Thread* thread);
615 
616   // Call before/after evacuation.
617   inline void enter_evacuation(Thread* t);
618   inline void leave_evacuation(Thread* t);
619 













620 // ---------- Helper functions
621 //
622 public:
623   template <class T>
624   inline void conc_update_with_forwarded(T* p);
625 
626   template <class T>
627   inline void update_with_forwarded(T* p);
628 
629   static inline void atomic_update_oop(oop update,       oop* addr,       oop compare);
630   static inline void atomic_update_oop(oop update, narrowOop* addr,       oop compare);
631   static inline void atomic_update_oop(oop update, narrowOop* addr, narrowOop compare);
632 
633   static inline bool atomic_update_oop_check(oop update,       oop* addr,       oop compare);
634   static inline bool atomic_update_oop_check(oop update, narrowOop* addr,       oop compare);
635   static inline bool atomic_update_oop_check(oop update, narrowOop* addr, narrowOop compare);
636 
637   static inline void atomic_clear_oop(      oop* addr,       oop compare);
638   static inline void atomic_clear_oop(narrowOop* addr,       oop compare);
639   static inline void atomic_clear_oop(narrowOop* addr, narrowOop compare);
640 
641   void trash_humongous_region_at(ShenandoahHeapRegion *r);











642 
643 private:
644   void trash_cset_regions();
645 
646 // ---------- Testing helpers functions
647 //
648 private:
649   ShenandoahSharedFlag _inject_alloc_failure;
650 
651   void try_inject_alloc_failure();
652   bool should_inject_alloc_failure();
653 };
654 
655 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHHEAP_HPP
--- EOF ---