1 /*
2 * Copyright (c) 2013, 2015, Red Hat, Inc. and/or its affiliates.
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_VM_GC_SHENANDOAH_SHENANDOAHHEAP_HPP
25 #define SHARE_VM_GC_SHENANDOAH_SHENANDOAHHEAP_HPP
26
27 #include "gc/shared/cmBitMap.hpp"
28
29 class ConcurrentGCTimer;
30
31 class ShenandoahCollectorPolicy;
32 class ShenandoahHeapRegion;
33 class ShenandoahHeapRegionClosure;
34 class ShenandoahHeapRegionSet;
35 class ShenandoahCollectionSet;
36 class ShenandoahFreeSet;
37 class ShenandoahConcurrentMark;
38 class ShenandoahConcurrentThread;
39 class ShenandoahMonitoringSupport;
40
41 class ShenandoahAlwaysTrueClosure : public BoolObjectClosure {
42 public:
43 bool do_object_b(oop p) { return true; }
44 };
45
46
47 class ShenandoahForwardedIsAliveClosure: public BoolObjectClosure {
48 private:
49 ShenandoahHeap* _heap;
50 public:
51 ShenandoahForwardedIsAliveClosure();
52 void init(ShenandoahHeap* heap);
53 bool do_object_b(oop obj);
54 };
55
56
57 // // A "ShenandoahHeap" is an implementation of a java heap for HotSpot.
58 // // It uses a new pauseless GC algorithm based on Brooks pointers.
59 // // Derived from G1
60
61 // //
62 // // CollectedHeap
63 // // SharedHeap
64 // // ShenandoahHeap
65
66 class ShenandoahHeap : public CollectedHeap {
67 public:
68 enum ShenandoahCancelCause {
69 _oom_evacuation,
70 _vm_stop,
71 };
72 private:
73
74 static ShenandoahHeap* _pgc;
75 ShenandoahCollectorPolicy* _shenandoah_policy;
76 VirtualSpace _storage;
77 ShenandoahHeapRegion* _first_region;
78 HeapWord* _first_region_bottom;
79
80 // Sortable array of regions
81 ShenandoahHeapRegionSet* _ordered_regions;
82 ShenandoahHeapRegionSet* _sorted_regions;
83 ShenandoahFreeSet* _free_regions;
84 ShenandoahCollectionSet* _collection_set;
85 ShenandoahHeapRegion* _currentAllocationRegion;
86 ShenandoahConcurrentMark* _scm;
87
88
89
90 ShenandoahConcurrentThread* _concurrent_gc_thread;
91
92 ShenandoahMonitoringSupport* _monitoring_support;
93
94 size_t _num_regions;
95 size_t _max_regions;
96 size_t _initialSize;
97 #ifndef NDEBUG
98 uint _numAllocs;
99 #endif
100 uint _max_parallel_workers;
101 uint _max_conc_workers;
102 uint _max_workers;
103
104 WorkGang* _conc_workers;
105 WorkGang* _workers;
106
107
108 volatile size_t _used;
109
110 CMBitMap _mark_bit_map0;
111 CMBitMap _mark_bit_map1;
112 CMBitMap* _complete_mark_bit_map;
113 CMBitMap* _next_mark_bit_map;
114
115 bool* _in_cset_fast_test;
116 bool* _in_cset_fast_test_base;
117 size_t _in_cset_fast_test_length;
118
119 HeapWord** _complete_top_at_mark_starts;
120 HeapWord** _complete_top_at_mark_starts_base;
121
122 HeapWord** _next_top_at_mark_starts;
123 HeapWord** _next_top_at_mark_starts_base;
124
125 volatile jbyte _cancelled_concgc;
126
127 jbyte _growing_heap;
128
129 size_t _bytes_allocated_since_cm;
130 size_t _bytes_allocated_during_cm;
131 size_t _bytes_allocated_during_cm_start;
132 size_t _max_allocated_gc;
133 size_t _allocated_last_gc;
134 size_t _used_start_gc;
135
136 unsigned int _concurrent_mark_in_progress;
137
138 bool _full_gc_in_progress;
139
140 unsigned int _evacuation_in_progress;
141 bool _need_update_refs;
142 bool _need_reset_bitmaps;
143
144 ReferenceProcessor* _ref_processor;
145
146 ShenandoahForwardedIsAliveClosure isAlive;
147
148 ConcurrentGCTimer* _gc_timer;
149
150 public:
151 ShenandoahHeap(ShenandoahCollectorPolicy* policy);
152
153 HeapWord *first_region_bottom() { return _first_region_bottom; }
154
155 const char* name() const /* override */;
156 HeapWord* allocate_new_tlab(size_t word_size) /* override */;
157 void print_on(outputStream* st) const /* override */;
158
159 ShenandoahHeap::Name kind() const /* override */{
160 return CollectedHeap::ShenandoahHeap;
161 }
162
163 jint initialize() /* override */;
164 void post_initialize() /* override */;
165 size_t capacity() const /* override */;
166 size_t used() const /* override */;
167 bool is_maximal_no_gc() const /* override */;
168 size_t max_capacity() const /* override */;
169 size_t min_capacity() const /* override */;
170 bool is_in(const void* p) const /* override */;
171 bool is_scavengable(const void* addr) /* override */;
172 HeapWord* mem_allocate(size_t size, bool* what) /* override */;
173 bool can_elide_tlab_store_barriers() const /* override */;
174 oop new_store_pre_barrier(JavaThread* thread, oop new_obj) /* override */;
175 bool can_elide_initializing_store_barrier(oop new_obj) /* override */;
176 bool card_mark_must_follow_store() const /* override */;
177 void collect(GCCause::Cause) /* override */;
178 void do_full_collection(bool clear_all_soft_refs) /* override */;
179 AdaptiveSizePolicy* size_policy() /* override */;
180 CollectorPolicy* collector_policy() const /* override */;
181 void ensure_parsability(bool retire_tlabs) /* override */;
182 HeapWord* block_start(const void* addr) const /* override */;
183 size_t block_size(const HeapWord* addr) const /* override */;
184 bool block_is_obj(const HeapWord* addr) const /* override */;
185 jlong millis_since_last_gc() /* override */;
186 void prepare_for_verify() /* override */;
187 void print_gc_threads_on(outputStream* st) const /* override */;
188 void gc_threads_do(ThreadClosure* tcl) const /* override */;
189 void print_tracing_info() const /* override */;
190 void verify(VerifyOption vo) /* override */;
191 bool supports_tlab_allocation() const /* override */;
192 size_t tlab_capacity(Thread *thr) const /* override */;
193 void object_iterate(ObjectClosure* cl) /* override */;
194 void safe_object_iterate(ObjectClosure* cl) /* override */;
195 size_t unsafe_max_tlab_alloc(Thread *thread) const /* override */;
196 size_t max_tlab_size() const /* override */;
197 void resize_all_tlabs() /* override */;
198 void accumulate_statistics_all_gclabs() /* override */;
199 HeapWord* tlab_post_allocation_setup(HeapWord* obj) /* override */;
200 uint oop_extra_words() /* override */;
201 size_t tlab_used(Thread* ignored) const /* override */;
202 void stop() /* override */;
203
204 #ifndef CC_INTERP
205 void compile_prepare_oop(MacroAssembler* masm, Register obj) /* override */;
206 #endif
207
208 void register_nmethod(nmethod* nm);
209 void unregister_nmethod(nmethod* nm);
210
211 void pin_object(oop o) /* override */;
212 void unpin_object(oop o) /* override */;
213
214 static ShenandoahHeap* heap();
215 static ShenandoahHeap* heap_no_check();
216 static size_t conservative_max_heap_alignment();
217 static address in_cset_fast_test_addr();
218 static address cancelled_concgc_addr();
219
220 static void pretouch_storage(char* start, char* end, WorkGang* workers);
221
222 ShenandoahCollectorPolicy *shenandoahPolicy() { return _shenandoah_policy;}
223
224 inline ShenandoahHeapRegion* heap_region_containing(const void* addr) const;
225 inline uint heap_region_index_containing(const void* addr) const;
226 inline bool requires_marking(const void* entry) const;
227 template <class T>
228 inline oop maybe_update_oop_ref(T* p);
229
230 void recycle_dirty_regions();
231
232 void start_concurrent_marking();
233 void stop_concurrent_marking();
234 inline bool concurrent_mark_in_progress();
235 static address concurrent_mark_in_progress_addr();
236
237 void prepare_for_concurrent_evacuation();
238 void evacuate_and_update_roots();
239 inline bool is_evacuation_in_progress();
240 void set_evacuation_in_progress(bool in_progress);
241
242 void set_full_gc_in_progress(bool in_progress);
243 bool is_full_gc_in_progress() const;
244
245 inline bool need_update_refs() const;
246 void set_need_update_refs(bool update_refs);
247
248 inline bool region_in_collection_set(size_t region_index) const;
249
250 void set_region_in_collection_set(size_t region_index, bool b);
251
252 // Mainly there to avoid accidentally calling the templated
253 // method below with ShenandoahHeapRegion* which would be *wrong*.
254 inline bool in_collection_set(ShenandoahHeapRegion* r) const;
255
256 template <class T>
257 inline bool in_collection_set(T obj) const;
258
259 void clear_cset_fast_test();
260
261 inline bool allocated_after_next_mark_start(HeapWord* addr) const;
262 void set_next_top_at_mark_start(HeapWord* region_base, HeapWord* addr);
263 HeapWord* next_top_at_mark_start(HeapWord* region_base);
264
265 inline bool allocated_after_complete_mark_start(HeapWord* addr) const;
266 void set_complete_top_at_mark_start(HeapWord* region_base, HeapWord* addr);
267 HeapWord* complete_top_at_mark_start(HeapWord* region_base);
268
269 inline oop evacuate_object(oop src, Thread* thread);
270 inline bool cancelled_concgc() const;
271 inline bool try_cancel_concgc() const;
272 void clear_cancelled_concgc();
273
274 ShenandoahHeapRegionSet* regions() { return _ordered_regions;}
275 ShenandoahHeapRegionSet* sorted_regions() { return _sorted_regions;}
276 ShenandoahFreeSet* free_regions();
277 void clear_free_regions();
278 void add_free_region(ShenandoahHeapRegion* r);
279
280 void increase_used(size_t bytes);
281 void decrease_used(size_t bytes);
282
283 void set_used(size_t bytes);
284 size_t calculateUsed();
285
286 void reset_next_mark_bitmap(WorkGang* gang);
287 void reset_complete_mark_bitmap(WorkGang* gang);
288
289 CMBitMap* complete_mark_bit_map();
290 CMBitMap* next_mark_bit_map();
291 inline bool is_marked_complete(oop obj) const;
292 inline bool mark_next(oop obj) const;
293 inline bool is_marked_next(oop obj) const;
294 bool is_next_bitmap_clear();
295 bool is_complete_bitmap_clear_range(HeapWord* start, HeapWord* end);
296
297 void parallel_evacuate_region(ShenandoahHeapRegion* from_region);
298
299 template <class T>
300 inline oop update_oop_ref_not_null(T* p, oop obj);
301
302 void print_heap_regions(outputStream* st = tty) const;
303 void print_all_refs(const char* prefix);
304 void print_heap_locations(HeapWord* start, HeapWord* end);
305
306 size_t bytes_allocated_since_cm();
307 void set_bytes_allocated_since_cm(size_t bytes);
308
309 size_t max_allocated_gc();
310
311 void reclaim_humongous_region_at(ShenandoahHeapRegion* r);
312
313 VirtualSpace* storage() const;
314
315 ShenandoahMonitoringSupport* monitoring_support();
316 ShenandoahConcurrentMark* concurrentMark() { return _scm;}
317
318 ReferenceProcessor* ref_processor() { return _ref_processor;}
319
320 WorkGang* conc_workers() const { return _conc_workers;}
321 WorkGang* workers() const { return _workers;}
322
323 uint max_conc_workers();
324 uint max_workers();
325 uint max_parallel_workers();
326
327 void do_evacuation();
328 ShenandoahHeapRegion* next_compaction_region(const ShenandoahHeapRegion* r);
329
330 void heap_region_iterate(ShenandoahHeapRegionClosure* blk, bool skip_dirty_regions = false, bool skip_humongous_continuation = false) const;
331
332 void verify_heap_after_evacuation();
333
334 // Delete entries for dead interned string and clean up unreferenced symbols
335 // in symbol table, possibly in parallel.
336 void unlink_string_and_symbol_table(BoolObjectClosure* is_alive, bool unlink_strings = true, bool unlink_symbols = true);
337
338 size_t num_regions();
339 size_t max_regions();
340
341 // TODO: consider moving this into ShenandoahHeapRegion.
342
343 template<class T>
344 inline void marked_object_iterate(ShenandoahHeapRegion* region, T* cl);
345
346 GCTimer* gc_timer() const;
347
348 void swap_mark_bitmaps();
349
350 private:
351 HeapWord* allocate_new_tlab(size_t word_size, bool mark);
352 HeapWord* allocate_memory(size_t word_size, bool evacuating);
353 // Shenandoah functionality.
354 inline HeapWord* allocate_from_gclab(Thread* thread, size_t size);
355 HeapWord* allocate_from_gclab_slow(Thread* thread, size_t size);
356 HeapWord* allocate_new_gclab(size_t word_size);
357
358 void roots_iterate(OopClosure* cl);
359
360 template<class T>
361 inline void do_marked_object(CMBitMap* bitmap, T* cl, oop obj);
362
363 ShenandoahConcurrentThread* concurrent_thread() { return _concurrent_gc_thread; }
364
365 inline bool mark_next_no_checks(oop obj) const;
366
367 void parallel_evacuate();
368
369 template <class T>
370 inline oop maybe_update_oop_ref_not_null(T* p, oop obj);
371
372 inline oop atomic_compare_exchange_oop(oop n, narrowOop* addr, oop c);
373 inline oop atomic_compare_exchange_oop(oop n, oop* addr, oop c);
374
375 void evacuate_region(ShenandoahHeapRegion* from_region, ShenandoahHeapRegion* to_region);
376
377 #ifdef ASSERT
378 void verify_evacuated_region(ShenandoahHeapRegion* from_region);
379 #endif
380
381 inline void copy_object(oop p, HeapWord* s, size_t words);
382 void verify_copy(oop p, oop c);
383 void verify_heap_size_consistency();
384 void verify_heap_after_marking();
385 void verify_heap_after_update_refs();
386 void verify_regions_after_update_refs();
387
388 void ref_processing_init();
389
390 GCTracer* tracer();
391 ShenandoahCollectionSet* collection_set() { return _collection_set; }
392
393 bool call_from_write_barrier(bool evacuating);
394 bool check_grow_heap();
395 void grow_heap_by(size_t num_regions);
396 void ensure_new_regions(size_t num_new_regions);
397
398 void verify_evacuation(ShenandoahHeapRegion* from_region);
399 void set_concurrent_mark_in_progress(bool in_progress);
400
401 void oom_during_evacuation();
402 void cancel_concgc(GCCause::Cause cause);
403 void cancel_concgc(ShenandoahCancelCause cause);
404 inline void set_cancelled_concgc(bool v);
405
406 void verify_live();
407 void verify_liveness_after_concurrent_mark();
408
409 HeapWord* allocate_memory_work(size_t word_size);
410 HeapWord* allocate_large_memory(size_t word_size);
411
412 void set_from_region_protection(bool protect);
413
414 const char* cancel_cause_to_string(ShenandoahCancelCause cause);
415
416 };
417
418 #endif // SHARE_VM_GC_SHENANDOAH_SHENANDOAHHEAP_HPP