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src/hotspot/share/gc/shenandoah/shenandoahHeapRegion.hpp

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  1 /*
  2  * Copyright (c) 2013, 2019, Red Hat, Inc. All rights reserved.

  3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  4  *
  5  * This code is free software; you can redistribute it and/or modify it
  6  * under the terms of the GNU General Public License version 2 only, as
  7  * published by the Free Software Foundation.
  8  *
  9  * This code is distributed in the hope that it will be useful, but WITHOUT
 10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 12  * version 2 for more details (a copy is included in the LICENSE file that
 13  * accompanied this code).
 14  *
 15  * You should have received a copy of the GNU General Public License version
 16  * 2 along with this work; if not, write to the Free Software Foundation,
 17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 18  *
 19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 20  * or visit www.oracle.com if you need additional information or have any
 21  * questions.
 22  *
 23  */
 24 
 25 #ifndef SHARE_GC_SHENANDOAH_SHENANDOAHHEAPREGION_HPP
 26 #define SHARE_GC_SHENANDOAH_SHENANDOAHHEAPREGION_HPP
 27 
 28 #include "gc/shared/gc_globals.hpp"
 29 #include "gc/shared/spaceDecorator.hpp"


 30 #include "gc/shenandoah/shenandoahAllocRequest.hpp"
 31 #include "gc/shenandoah/shenandoahAsserts.hpp"
 32 #include "gc/shenandoah/shenandoahHeap.hpp"
 33 #include "gc/shenandoah/shenandoahPacer.hpp"
 34 #include "gc/shenandoah/shenandoahPadding.hpp"
 35 #include "utilities/sizes.hpp"
 36 
 37 class VMStructs;
 38 class ShenandoahHeapRegionStateConstant;
 39 
 40 class ShenandoahHeapRegion {
 41   friend class VMStructs;
 42   friend class ShenandoahHeapRegionStateConstant;
 43 private:
 44   /*
 45     Region state is described by a state machine. Transitions are guarded by
 46     heap lock, which allows changing the state of several regions atomically.
 47     Region states can be logically aggregated in groups.
 48 
 49       "Empty":
 50       .................................................................
 51       .                                                               .
 52       .                                                               .
 53       .         Uncommitted  <-------  Committed <------------------------\

106       h) Humongous start can go pinned, and thus can be protected from moves (humongous continuations should
107          follow associated humongous starts, not pinnable/movable by themselves);
108       i) Empty cannot go Trash, avoiding useless work;
109       j) ...
110    */
111 
112   enum RegionState {
113     _empty_uncommitted,       // region is empty and has memory uncommitted
114     _empty_committed,         // region is empty and has memory committed
115     _regular,                 // region is for regular allocations
116     _humongous_start,         // region is the humongous start
117     _humongous_cont,          // region is the humongous continuation
118     _pinned_humongous_start,  // region is both humongous start and pinned
119     _cset,                    // region is in collection set
120     _pinned,                  // region is pinned
121     _pinned_cset,             // region is pinned and in cset (evac failure path)
122     _trash,                   // region contains only trash
123     _REGION_STATES_NUM        // last
124   };
125 

126   static const char* region_state_to_string(RegionState s) {
127     switch (s) {
128       case _empty_uncommitted:       return "Empty Uncommitted";
129       case _empty_committed:         return "Empty Committed";
130       case _regular:                 return "Regular";
131       case _humongous_start:         return "Humongous Start";
132       case _humongous_cont:          return "Humongous Continuation";
133       case _pinned_humongous_start:  return "Humongous Start, Pinned";
134       case _cset:                    return "Collection Set";
135       case _pinned:                  return "Pinned";
136       case _pinned_cset:             return "Collection Set, Pinned";
137       case _trash:                   return "Trash";
138       default:
139         ShouldNotReachHere();
140         return "";
141     }
142   }
143 

144   // This method protects from accidental changes in enum order:
145   int region_state_to_ordinal(RegionState s) const {
146     switch (s) {
147       case _empty_uncommitted:      return 0;
148       case _empty_committed:        return 1;
149       case _regular:                return 2;
150       case _humongous_start:        return 3;
151       case _humongous_cont:         return 4;
152       case _cset:                   return 5;
153       case _pinned:                 return 6;
154       case _trash:                  return 7;
155       case _pinned_cset:            return 8;
156       case _pinned_humongous_start: return 9;
157       default:
158         ShouldNotReachHere();
159         return -1;
160     }
161   }
162 
163   void report_illegal_transition(const char* method);

164 
165 public:
166   static const int region_states_num() {
167     return _REGION_STATES_NUM;
168   }
169 
170   // Allowed transitions from the outside code:
171   void make_regular_allocation();

172   void make_regular_bypass();
173   void make_humongous_start();
174   void make_humongous_cont();
175   void make_humongous_start_bypass();
176   void make_humongous_cont_bypass();
177   void make_pinned();
178   void make_unpinned();
179   void make_cset();
180   void make_trash();
181   void make_trash_immediate();
182   void make_empty();
183   void make_uncommitted();
184   void make_committed_bypass();
185 
186   // Individual states:
187   bool is_empty_uncommitted()      const { return _state == _empty_uncommitted; }
188   bool is_empty_committed()        const { return _state == _empty_committed; }
189   bool is_regular()                const { return _state == _regular; }
190   bool is_humongous_continuation() const { return _state == _humongous_cont; }
191 
192   // Participation in logical groups:
193   bool is_empty()                  const { return is_empty_committed() || is_empty_uncommitted(); }
194   bool is_active()                 const { return !is_empty() && !is_trash(); }
195   bool is_trash()                  const { return _state == _trash; }
196   bool is_humongous_start()        const { return _state == _humongous_start || _state == _pinned_humongous_start; }
197   bool is_humongous()              const { return is_humongous_start() || is_humongous_continuation(); }



198   bool is_committed()              const { return !is_empty_uncommitted(); }
199   bool is_cset()                   const { return _state == _cset   || _state == _pinned_cset; }
200   bool is_pinned()                 const { return _state == _pinned || _state == _pinned_cset || _state == _pinned_humongous_start; }




201 
202   // Macro-properties:
203   bool is_alloc_allowed()          const { return is_empty() || is_regular() || _state == _pinned; }
204   bool is_stw_move_allowed()       const { return is_regular() || _state == _cset || (ShenandoahHumongousMoves && _state == _humongous_start); }
205 
206   RegionState state()              const { return _state; }
207   int  state_ordinal()             const { return region_state_to_ordinal(_state); }
208 
209   void record_pin();
210   void record_unpin();
211   size_t pin_count() const;
212 
213 private:
214   static size_t RegionCount;
215   static size_t RegionSizeBytes;
216   static size_t RegionSizeWords;
217   static size_t RegionSizeBytesShift;
218   static size_t RegionSizeWordsShift;
219   static size_t RegionSizeBytesMask;
220   static size_t RegionSizeWordsMask;
221   static size_t HumongousThresholdBytes;
222   static size_t HumongousThresholdWords;
223   static size_t MaxTLABSizeBytes;
224   static size_t MaxTLABSizeWords;
225 
226   // Never updated fields
227   size_t const _index;
228   HeapWord* const _bottom;
229   HeapWord* const _end;
230 
231   // Rarely updated fields
232   HeapWord* _new_top;
233   double _empty_time;
234 


235   // Seldom updated fields
236   RegionState _state;

237 
238   // Frequently updated fields
239   HeapWord* _top;
240 
241   size_t _tlab_allocs;
242   size_t _gclab_allocs;

243 
244   volatile size_t _live_data;
245   volatile size_t _critical_pins;
246 
247   HeapWord* volatile _update_watermark;
248 







249 public:
250   ShenandoahHeapRegion(HeapWord* start, size_t index, bool committed);
251 
252   static const size_t MIN_NUM_REGIONS = 10;
253 
254   // Return adjusted max heap size
255   static size_t setup_sizes(size_t max_heap_size);
256 
257   double empty_time() {
258     return _empty_time;
259   }
260 
261   inline static size_t required_regions(size_t bytes) {
262     return (bytes + ShenandoahHeapRegion::region_size_bytes() - 1) >> ShenandoahHeapRegion::region_size_bytes_shift();
263   }
264 




265   inline static size_t region_count() {
266     return ShenandoahHeapRegion::RegionCount;
267   }
268 
269   inline static size_t region_size_bytes() {
270     return ShenandoahHeapRegion::RegionSizeBytes;
271   }
272 
273   inline static size_t region_size_words() {
274     return ShenandoahHeapRegion::RegionSizeWords;
275   }
276 
277   inline static size_t region_size_bytes_shift() {
278     return ShenandoahHeapRegion::RegionSizeBytesShift;
279   }
280 
281   inline static size_t region_size_words_shift() {
282     return ShenandoahHeapRegion::RegionSizeWordsShift;
283   }
284 

297   }
298 
299   // Convert to jint with sanity checking
300   inline static jint region_size_words_jint() {
301     assert (ShenandoahHeapRegion::RegionSizeWords <= (size_t)max_jint, "sanity");
302     return (jint)ShenandoahHeapRegion::RegionSizeWords;
303   }
304 
305   // Convert to jint with sanity checking
306   inline static jint region_size_bytes_shift_jint() {
307     assert (ShenandoahHeapRegion::RegionSizeBytesShift <= (size_t)max_jint, "sanity");
308     return (jint)ShenandoahHeapRegion::RegionSizeBytesShift;
309   }
310 
311   // Convert to jint with sanity checking
312   inline static jint region_size_words_shift_jint() {
313     assert (ShenandoahHeapRegion::RegionSizeWordsShift <= (size_t)max_jint, "sanity");
314     return (jint)ShenandoahHeapRegion::RegionSizeWordsShift;
315   }
316 
317   inline static size_t humongous_threshold_bytes() {
318     return ShenandoahHeapRegion::HumongousThresholdBytes;
319   }
320 
321   inline static size_t humongous_threshold_words() {
322     return ShenandoahHeapRegion::HumongousThresholdWords;
323   }
324 
325   inline static size_t max_tlab_size_bytes() {
326     return ShenandoahHeapRegion::MaxTLABSizeBytes;
327   }
328 
329   inline static size_t max_tlab_size_words() {
330     return ShenandoahHeapRegion::MaxTLABSizeWords;
331   }
332 
333   inline size_t index() const {
334     return _index;
335   }
336 
337   // Allocation (return null if full)
338   inline HeapWord* allocate(size_t word_size, ShenandoahAllocRequest::Type type);











339 
340   inline void clear_live_data();
341   void set_live_data(size_t s);
342 
343   // Increase live data for newly allocated region
344   inline void increase_live_data_alloc_words(size_t s);
345 
346   // Increase live data for region scanned with GC
347   inline void increase_live_data_gc_words(size_t s);
348 
349   inline bool has_live() const;
350   inline size_t get_live_data_bytes() const;
351   inline size_t get_live_data_words() const;
352 
353   inline size_t garbage() const;
354 
355   void print_on(outputStream* st) const;
356 
357   void recycle();
























358 
359   void oop_iterate(OopIterateClosure* cl);







360 
361   HeapWord* block_start(const void* p) const;
362   size_t block_size(const HeapWord* p) const;
363   bool block_is_obj(const HeapWord* p) const { return p < top(); }
364 
365   // Find humongous start region that this region belongs to
366   ShenandoahHeapRegion* humongous_start_region() const;
367 
368   HeapWord* top() const         { return _top;     }
369   void set_top(HeapWord* v)     { _top = v;        }
370 
371   HeapWord* new_top() const     { return _new_top; }
372   void set_new_top(HeapWord* v) { _new_top = v;    }
373 
374   HeapWord* bottom() const      { return _bottom;  }
375   HeapWord* end() const         { return _end;     }
376 
377   size_t capacity() const       { return byte_size(bottom(), end()); }
378   size_t used() const           { return byte_size(bottom(), top()); }

379   size_t free() const           { return byte_size(top(),    end()); }
380 





381   inline void adjust_alloc_metadata(ShenandoahAllocRequest::Type type, size_t);
382   void reset_alloc_metadata();
383   size_t get_shared_allocs() const;
384   size_t get_tlab_allocs() const;
385   size_t get_gclab_allocs() const;

386 
387   inline HeapWord* get_update_watermark() const;
388   inline void set_update_watermark(HeapWord* w);
389   inline void set_update_watermark_at_safepoint(HeapWord* w);
390 




































391 private:

392   void do_commit();
393   void do_uncommit();
394 
395   void oop_iterate_objects(OopIterateClosure* cl);
396   void oop_iterate_humongous(OopIterateClosure* cl);
397 
398   inline void internal_increase_live_data(size_t s);
399 
400   void set_state(RegionState to);
401 };
402 
403 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHHEAPREGION_HPP

  1 /*
  2  * Copyright (c) 2013, 2019, Red Hat, Inc. All rights reserved.
  3  * Copyright Amazon.com Inc. or its affiliates. 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
 22  * questions.
 23  *
 24  */
 25 
 26 #ifndef SHARE_GC_SHENANDOAH_SHENANDOAHHEAPREGION_HPP
 27 #define SHARE_GC_SHENANDOAH_SHENANDOAHHEAPREGION_HPP
 28 
 29 #include "gc/shared/gc_globals.hpp"
 30 #include "gc/shared/spaceDecorator.hpp"
 31 #include "gc/shenandoah/shenandoahAffiliation.hpp"
 32 #include "gc/shenandoah/shenandoahAgeCensus.hpp"
 33 #include "gc/shenandoah/shenandoahAllocRequest.hpp"
 34 #include "gc/shenandoah/shenandoahAsserts.hpp"
 35 #include "gc/shenandoah/shenandoahHeap.hpp"

 36 #include "gc/shenandoah/shenandoahPadding.hpp"
 37 #include "utilities/sizes.hpp"
 38 
 39 class VMStructs;
 40 class ShenandoahHeapRegionStateConstant;
 41 
 42 class ShenandoahHeapRegion {
 43   friend class VMStructs;
 44   friend class ShenandoahHeapRegionStateConstant;
 45 private:
 46   /*
 47     Region state is described by a state machine. Transitions are guarded by
 48     heap lock, which allows changing the state of several regions atomically.
 49     Region states can be logically aggregated in groups.
 50 
 51       "Empty":
 52       .................................................................
 53       .                                                               .
 54       .                                                               .
 55       .         Uncommitted  <-------  Committed <------------------------\

108       h) Humongous start can go pinned, and thus can be protected from moves (humongous continuations should
109          follow associated humongous starts, not pinnable/movable by themselves);
110       i) Empty cannot go Trash, avoiding useless work;
111       j) ...
112    */
113 
114   enum RegionState {
115     _empty_uncommitted,       // region is empty and has memory uncommitted
116     _empty_committed,         // region is empty and has memory committed
117     _regular,                 // region is for regular allocations
118     _humongous_start,         // region is the humongous start
119     _humongous_cont,          // region is the humongous continuation
120     _pinned_humongous_start,  // region is both humongous start and pinned
121     _cset,                    // region is in collection set
122     _pinned,                  // region is pinned
123     _pinned_cset,             // region is pinned and in cset (evac failure path)
124     _trash,                   // region contains only trash
125     _REGION_STATES_NUM        // last
126   };
127 
128 public:
129   static const char* region_state_to_string(RegionState s) {
130     switch (s) {
131       case _empty_uncommitted:       return "Empty Uncommitted";
132       case _empty_committed:         return "Empty Committed";
133       case _regular:                 return "Regular";
134       case _humongous_start:         return "Humongous Start";
135       case _humongous_cont:          return "Humongous Continuation";
136       case _pinned_humongous_start:  return "Humongous Start, Pinned";
137       case _cset:                    return "Collection Set";
138       case _pinned:                  return "Pinned";
139       case _pinned_cset:             return "Collection Set, Pinned";
140       case _trash:                   return "Trash";
141       default:
142         ShouldNotReachHere();
143         return "";
144     }
145   }
146 
147 private:
148   // This method protects from accidental changes in enum order:
149   int region_state_to_ordinal(RegionState s) const {
150     switch (s) {
151       case _empty_uncommitted:      return 0;
152       case _empty_committed:        return 1;
153       case _regular:                return 2;
154       case _humongous_start:        return 3;
155       case _humongous_cont:         return 4;
156       case _cset:                   return 5;
157       case _pinned:                 return 6;
158       case _trash:                  return 7;
159       case _pinned_cset:            return 8;
160       case _pinned_humongous_start: return 9;
161       default:
162         ShouldNotReachHere();
163         return -1;
164     }
165   }
166 
167   void report_illegal_transition(const char* method);
168   void recycle_internal();
169 
170 public:
171   static int region_states_num() {
172     return _REGION_STATES_NUM;
173   }
174 
175   // Allowed transitions from the outside code:
176   void make_regular_allocation(ShenandoahAffiliation affiliation);
177   void make_affiliated_maybe();
178   void make_regular_bypass();
179   void make_humongous_start();
180   void make_humongous_cont();
181   void make_humongous_start_bypass(ShenandoahAffiliation affiliation);
182   void make_humongous_cont_bypass(ShenandoahAffiliation affiliation);
183   void make_pinned();
184   void make_unpinned();
185   void make_cset();
186   void make_trash();
187   void make_trash_immediate();
188   void make_empty();
189   void make_uncommitted();
190   void make_committed_bypass();
191 
192   // Primitive state predicates
193   bool is_empty_uncommitted()      const { return state() == _empty_uncommitted; }
194   bool is_empty_committed()        const { return state() == _empty_committed; }
195   bool is_regular()                const { return state() == _regular; }
196   bool is_humongous_continuation() const { return state() == _humongous_cont; }
197   bool is_regular_pinned()         const { return state() == _pinned; }
198   bool is_trash()                  const { return state() == _trash; }
199 
200   // Derived state predicates (boolean combinations of individual states)
201   bool static is_empty_state(RegionState state) { return state == _empty_committed || state == _empty_uncommitted; }
202   bool static is_humongous_start_state(RegionState state) { return state == _humongous_start || state == _pinned_humongous_start; }
203   bool is_empty()                  const { return is_empty_state(this->state()); }
204   bool is_active()                 const { auto cur_state = state(); return !is_empty_state(cur_state) && cur_state != _trash; }
205   bool is_humongous_start()        const { return is_humongous_start_state(state()); }
206   bool is_humongous()              const { auto cur_state = state(); return is_humongous_start_state(cur_state) || cur_state == _humongous_cont; }
207   bool is_committed()              const { return !is_empty_uncommitted(); }
208   bool is_cset()                   const { auto cur_state = state(); return cur_state == _cset || cur_state == _pinned_cset; }
209   bool is_pinned()                 const { auto cur_state = state(); return cur_state == _pinned || cur_state == _pinned_cset || cur_state == _pinned_humongous_start; }
210 
211   inline bool is_young() const;
212   inline bool is_old() const;
213   inline bool is_affiliated() const;
214 
215   // Macro-properties:
216   bool is_alloc_allowed()          const { auto cur_state = state(); return is_empty_state(cur_state) || cur_state == _regular || cur_state == _pinned; }
217   bool is_stw_move_allowed()       const { auto cur_state = state(); return cur_state == _regular || cur_state == _cset || (ShenandoahHumongousMoves && cur_state == _humongous_start); }
218 
219   RegionState state()              const { return Atomic::load(&_state); }
220   int  state_ordinal()             const { return region_state_to_ordinal(state()); }
221 
222   void record_pin();
223   void record_unpin();
224   size_t pin_count() const;
225 
226 private:
227   static size_t RegionCount;
228   static size_t RegionSizeBytes;
229   static size_t RegionSizeWords;
230   static size_t RegionSizeBytesShift;
231   static size_t RegionSizeWordsShift;
232   static size_t RegionSizeBytesMask;
233   static size_t RegionSizeWordsMask;


234   static size_t MaxTLABSizeBytes;
235   static size_t MaxTLABSizeWords;
236 
237   // Never updated fields
238   size_t const _index;
239   HeapWord* const _bottom;
240   HeapWord* const _end;
241 
242   // Rarely updated fields
243   HeapWord* _new_top;
244   double _empty_time;
245 
246   HeapWord* _top_before_promoted;
247 
248   // Seldom updated fields
249   volatile RegionState _state;
250   HeapWord* _coalesce_and_fill_boundary; // for old regions not selected as collection set candidates.
251 
252   // Frequently updated fields
253   HeapWord* _top;
254 
255   size_t _tlab_allocs;
256   size_t _gclab_allocs;
257   size_t _plab_allocs;
258 
259   volatile size_t _live_data;
260   volatile size_t _critical_pins;
261 
262   HeapWord* volatile _update_watermark;
263 
264   uint _age;
265   CENSUS_NOISE(uint _youth;)   // tracks epochs of retrograde ageing (rejuvenation)
266 
267   ShenandoahSharedFlag _recycling; // Used to indicate that the region is being recycled; see try_recycle*().
268 
269   bool _needs_bitmap_reset;
270 
271 public:
272   ShenandoahHeapRegion(HeapWord* start, size_t index, bool committed);
273 
274   static const size_t MIN_NUM_REGIONS = 10;
275 
276   // Return adjusted max heap size
277   static size_t setup_sizes(size_t max_heap_size);
278 
279   double empty_time() {
280     return _empty_time;
281   }
282 
283   inline static size_t required_regions(size_t bytes) {
284     return (bytes + ShenandoahHeapRegion::region_size_bytes() - 1) >> ShenandoahHeapRegion::region_size_bytes_shift();
285   }
286 
287   inline static bool requires_humongous(size_t words) {
288     return words > ShenandoahHeapRegion::RegionSizeWords;
289   }
290 
291   inline static size_t region_count() {
292     return ShenandoahHeapRegion::RegionCount;
293   }
294 
295   inline static size_t region_size_bytes() {
296     return ShenandoahHeapRegion::RegionSizeBytes;
297   }
298 
299   inline static size_t region_size_words() {
300     return ShenandoahHeapRegion::RegionSizeWords;
301   }
302 
303   inline static size_t region_size_bytes_shift() {
304     return ShenandoahHeapRegion::RegionSizeBytesShift;
305   }
306 
307   inline static size_t region_size_words_shift() {
308     return ShenandoahHeapRegion::RegionSizeWordsShift;
309   }
310 

323   }
324 
325   // Convert to jint with sanity checking
326   inline static jint region_size_words_jint() {
327     assert (ShenandoahHeapRegion::RegionSizeWords <= (size_t)max_jint, "sanity");
328     return (jint)ShenandoahHeapRegion::RegionSizeWords;
329   }
330 
331   // Convert to jint with sanity checking
332   inline static jint region_size_bytes_shift_jint() {
333     assert (ShenandoahHeapRegion::RegionSizeBytesShift <= (size_t)max_jint, "sanity");
334     return (jint)ShenandoahHeapRegion::RegionSizeBytesShift;
335   }
336 
337   // Convert to jint with sanity checking
338   inline static jint region_size_words_shift_jint() {
339     assert (ShenandoahHeapRegion::RegionSizeWordsShift <= (size_t)max_jint, "sanity");
340     return (jint)ShenandoahHeapRegion::RegionSizeWordsShift;
341   }
342 








343   inline static size_t max_tlab_size_bytes() {
344     return ShenandoahHeapRegion::MaxTLABSizeBytes;
345   }
346 
347   inline static size_t max_tlab_size_words() {
348     return ShenandoahHeapRegion::MaxTLABSizeWords;
349   }
350 
351   inline size_t index() const {
352     return _index;
353   }
354 
355   inline void save_top_before_promote();
356   inline HeapWord* get_top_before_promote() const { return _top_before_promoted; }
357   inline void restore_top_before_promote();
358   inline size_t garbage_before_padded_for_promote() const;
359 
360   // If next available memory is not aligned on address that is multiple of alignment, fill the empty space
361   // so that returned object is aligned on an address that is a multiple of alignment_in_bytes.  Requested
362   // size is in words.  It is assumed that this->is_old().  A pad object is allocated, filled, and registered
363   // if necessary to assure the new allocation is properly aligned.  Return nullptr if memory is not available.
364   inline HeapWord* allocate_aligned(size_t word_size, ShenandoahAllocRequest &req, size_t alignment_in_bytes);
365 
366   // Allocation (return nullptr if full)
367   inline HeapWord* allocate(size_t word_size, const ShenandoahAllocRequest& req);
368 
369   inline void clear_live_data();
370   void set_live_data(size_t s);
371 
372   // Increase live data for newly allocated region
373   inline void increase_live_data_alloc_words(size_t s);
374 
375   // Increase live data for region scanned with GC
376   inline void increase_live_data_gc_words(size_t s);
377 
378   inline bool has_live() const;
379   inline size_t get_live_data_bytes() const;
380   inline size_t get_live_data_words() const;
381 
382   inline size_t garbage() const;
383 
384   void print_on(outputStream* st) const;
385 
386   void try_recycle_under_lock();
387 
388   void try_recycle();
389 
390   inline void begin_preemptible_coalesce_and_fill() {
391     _coalesce_and_fill_boundary = _bottom;
392   }
393 
394   inline void end_preemptible_coalesce_and_fill() {
395     _coalesce_and_fill_boundary = _end;
396   }
397 
398   inline void suspend_coalesce_and_fill(HeapWord* next_focus) {
399     _coalesce_and_fill_boundary = next_focus;
400   }
401 
402   inline HeapWord* resume_coalesce_and_fill() {
403     return _coalesce_and_fill_boundary;
404   }
405 
406   // Coalesce contiguous spans of garbage objects by filling header and registering start locations with remembered set.
407   // This is used by old-gen GC following concurrent marking to make old-gen HeapRegions parsable. Old regions must be
408   // parsable because the mark bitmap is not reliable during the concurrent old mark.
409   // Return true iff region is completely coalesced and filled.  Returns false if cancelled before task is complete.
410   bool oop_coalesce_and_fill(bool cancellable);
411 
412   // Invoke closure on every reference contained within the humongous object that spans this humongous
413   // region if the reference is contained within a DIRTY card and the reference is no more than words following
414   // start within the humongous object.
415   void oop_iterate_humongous_slice_dirty(OopIterateClosure* cl, HeapWord* start, size_t words, bool write_table) const;
416 
417   // Invoke closure on every reference contained within the humongous object starting from start and
418   // ending at start + words.
419   void oop_iterate_humongous_slice_all(OopIterateClosure* cl, HeapWord* start, size_t words) const;
420 
421   HeapWord* block_start(const void* p) const;
422   size_t block_size(const HeapWord* p) const;
423   bool block_is_obj(const HeapWord* p) const { return p < top(); }
424 
425   // Find humongous start region that this region belongs to
426   ShenandoahHeapRegion* humongous_start_region() const;
427 
428   HeapWord* top() const         { return _top;     }
429   void set_top(HeapWord* v)     { _top = v;        }
430 
431   HeapWord* new_top() const     { return _new_top; }
432   void set_new_top(HeapWord* v) { _new_top = v;    }
433 
434   HeapWord* bottom() const      { return _bottom;  }
435   HeapWord* end() const         { return _end;     }
436 
437   size_t capacity() const       { return byte_size(bottom(), end()); }
438   size_t used() const           { return byte_size(bottom(), top()); }
439   size_t used_before_promote() const { return byte_size(bottom(), get_top_before_promote()); }
440   size_t free() const           { return byte_size(top(),    end()); }
441 
442   // Does this region contain this address?
443   bool contains(HeapWord* p) const {
444     return (bottom() <= p) && (p < top());
445   }
446 
447   inline void adjust_alloc_metadata(ShenandoahAllocRequest::Type type, size_t);
448   void reset_alloc_metadata();
449   size_t get_shared_allocs() const;
450   size_t get_tlab_allocs() const;
451   size_t get_gclab_allocs() const;
452   size_t get_plab_allocs() const;
453 
454   inline HeapWord* get_update_watermark() const;
455   inline void set_update_watermark(HeapWord* w);
456   inline void set_update_watermark_at_safepoint(HeapWord* w);
457 
458   inline ShenandoahAffiliation affiliation() const;
459   inline const char* affiliation_name() const;
460 
461   void set_affiliation(ShenandoahAffiliation new_affiliation);
462 
463   // Region ageing and rejuvenation
464   uint age() const { return _age; }
465   CENSUS_NOISE(uint youth() const { return _youth; })
466 
467   void increment_age() {
468     const uint max_age = markWord::max_age;
469     assert(_age <= max_age, "Error");
470     if (_age++ >= max_age) {
471       _age = max_age;   // clamp
472     }
473   }
474 
475   void reset_age() {
476     CENSUS_NOISE(_youth += _age;)
477     _age = 0;
478   }
479 
480   CENSUS_NOISE(void clear_youth() { _youth = 0; })
481 
482   inline bool need_bitmap_reset() const {
483     return _needs_bitmap_reset;
484   }
485 
486   inline void set_needs_bitmap_reset() {
487     _needs_bitmap_reset = true;
488   }
489 
490   inline void unset_needs_bitmap_reset() {
491     _needs_bitmap_reset = false;
492   }
493 
494 private:
495   void decrement_humongous_waste() const;
496   void do_commit();
497   void do_uncommit();
498 



499   inline void internal_increase_live_data(size_t s);
500 
501   void set_state(RegionState to);
502 };
503 
504 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHHEAPREGION_HPP
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