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/markBitMap.hpp"
28 #include "gc/shenandoah/shenandoahHeapLock.hpp"
29 #include "gc/shenandoah/shenandoahWorkGroup.hpp"
30
31 class ConcurrentGCTimer;
32
33 class ShenandoahAllocTracker;
34 class ShenandoahCollectorPolicy;
35 class ShenandoahConnectionMatrix;
36 class ShenandoahPhaseTimings;
37 class ShenandoahHeapRegion;
38 class ShenandoahHeapRegionClosure;
39 class ShenandoahHeapRegionSet;
40 class ShenandoahCollectionSet;
41 class ShenandoahFreeSet;
42 class ShenandoahConcurrentMark;
43 class ShenandoahPartialGC;
44 class ShenandoahVerifier;
45 class ShenandoahConcurrentThread;
46 class ShenandoahMonitoringSupport;
47
48 class ShenandoahUpdateRefsClosure: public OopClosure {
49 private:
50 ShenandoahHeap* _heap;
51
52 template <class T>
53 inline void do_oop_work(T* p);
54
55 public:
56 ShenandoahUpdateRefsClosure();
57 inline void do_oop(oop* p);
58 inline void do_oop(narrowOop* p);
59 };
60
61 #ifdef ASSERT
62 class ShenandoahAssertToSpaceClosure : public OopClosure {
63 private:
64 template <class T>
65 void do_oop_nv(T* p);
66 public:
67 void do_oop(narrowOop* p);
68 void do_oop(oop* p);
69 };
70 #endif
71
72 class ShenandoahAlwaysTrueClosure : public BoolObjectClosure {
73 public:
74 bool do_object_b(oop p) { return true; }
75 };
76
77 class ShenandoahForwardedIsAliveClosure: public BoolObjectClosure {
78 private:
79 ShenandoahHeap* _heap;
80 public:
81 ShenandoahForwardedIsAliveClosure();
82 void init(ShenandoahHeap* heap) {
83 _heap = heap;
84 }
85 bool do_object_b(oop obj);
86 };
87
88 class ShenandoahIsAliveClosure: public BoolObjectClosure {
89 private:
90 ShenandoahHeap* _heap;
91 public:
92 ShenandoahIsAliveClosure();
93 void init(ShenandoahHeap* heap) {
94 _heap = heap;
95 }
96 bool do_object_b(oop obj);
97 };
98
99
100 // // A "ShenandoahHeap" is an implementation of a java heap for HotSpot.
101 // // It uses a new pauseless GC algorithm based on Brooks pointers.
102 // // Derived from G1
103
104 // //
105 // // CollectedHeap
106 // // SharedHeap
107 // // ShenandoahHeap
108
109 class ShenandoahHeap : public CollectedHeap {
110 enum CancelState {
111
112 // Normal state. GC has not been cancelled and is open for cancellation.
113 // Worker threads can suspend for safepoint.
114 CANCELLABLE,
115
116 // GC has been cancelled. Worker threads can not suspend for
117 // safepoint but must finish their work as soon as possible.
118 CANCELLED,
119
120 // GC has not been cancelled and must not be cancelled. At least
121 // one worker thread checks for pending safepoint and may suspend
122 // if a safepoint is pending.
123 NOT_CANCELLED
124
125 };
126
127 public:
128 enum ShenandoahCancelCause {
129 _oom_evacuation,
130 _vm_stop,
131 };
132 private:
133 ShenandoahHeapLock _lock;
134 ShenandoahCollectorPolicy* _shenandoah_policy;
135 size_t _bitmap_size;
136 size_t _bitmap_words_per_region;
137 MemRegion _heap_region;
138 MemRegion _bitmap0_region;
139 MemRegion _bitmap1_region;
140
141 // Sortable array of regions
142 ShenandoahHeapRegionSet* _ordered_regions;
143 ShenandoahFreeSet* _free_regions;
144 ShenandoahCollectionSet* _collection_set;
145
146 ShenandoahConcurrentMark* _scm;
147 ShenandoahPartialGC* _partial_gc;
148 ShenandoahVerifier* _verifier;
149
150 ShenandoahConcurrentThread* _concurrent_gc_thread;
151
152 ShenandoahMonitoringSupport* _monitoring_support;
153
154 ShenandoahPhaseTimings* _phase_timings;
155 ShenandoahAllocTracker* _alloc_tracker;
156
157 size_t _num_regions;
158 size_t _initial_size;
159
160 uint _max_workers;
161 ShenandoahWorkGang* _workers;
162 ShenandoahWorkGang* _safepoint_workers;
163
164 volatile size_t _used;
165 volatile size_t _committed;
166
167 MarkBitMap _verification_bit_map;
168 MarkBitMap _mark_bit_map0;
169 MarkBitMap _mark_bit_map1;
170 MarkBitMap* _complete_mark_bit_map;
171 MarkBitMap* _next_mark_bit_map;
172
173 HeapWord** _complete_top_at_mark_starts;
174 HeapWord** _complete_top_at_mark_starts_base;
175
176 HeapWord** _next_top_at_mark_starts;
177 HeapWord** _next_top_at_mark_starts_base;
178
179 volatile jbyte _cancelled_concgc;
180
181 size_t _bytes_allocated_since_cm;
182 size_t _bytes_allocated_during_cm;
183 size_t _allocated_last_gc;
184 size_t _used_start_gc;
185
186 char _concurrent_mark_in_progress;
187
188 bool _full_gc_in_progress;
189 bool _update_refs_in_progress;
190 bool _concurrent_partial_in_progress;
191
192 unsigned int _evacuation_in_progress;
193 bool _need_update_refs;
194 bool _need_reset_bitmaps;
195
196 ReferenceProcessor* _ref_processor;
197
198 ShenandoahForwardedIsAliveClosure _forwarded_is_alive;
199 ShenandoahIsAliveClosure _is_alive;
200
201 ConcurrentGCTimer* _gc_timer;
202
203 // See allocate_memory()
204 volatile jbyte _heap_lock;
205
206 ShenandoahConnectionMatrix* _connection_matrix;
207
208 #ifdef ASSERT
209 Thread* volatile _heap_lock_owner;
210 int _heap_expansion_count;
211 #endif
212
213 public:
214 ShenandoahHeap(ShenandoahCollectorPolicy* policy);
215
216 const char* name() const /* override */;
217 HeapWord* allocate_new_tlab(size_t word_size) /* override */;
218 void print_on(outputStream* st) const /* override */;
219 void print_extended_on(outputStream *st) const /* override */;
220
221 ShenandoahHeap::Name kind() const /* override */{
222 return CollectedHeap::ShenandoahHeap;
223 }
224
225 jint initialize() /* override */;
226 void post_initialize() /* override */;
227 size_t capacity() const /* override */;
228 size_t used() const /* override */;
229 size_t committed() const;
230 bool is_maximal_no_gc() const /* override */;
231 size_t max_capacity() const /* override */;
232 size_t initial_capacity() const /* override */;
233 bool is_in(const void* p) const /* override */;
234 bool is_scavengable(const void* addr) /* override */;
235 HeapWord* mem_allocate(size_t size, bool* what) /* override */;
236 bool can_elide_tlab_store_barriers() const /* override */;
237 oop new_store_pre_barrier(JavaThread* thread, oop new_obj) /* override */;
238 bool can_elide_initializing_store_barrier(oop new_obj) /* override */;
239 bool card_mark_must_follow_store() const /* override */;
240 void collect(GCCause::Cause cause) /* override */;
241 void do_full_collection(bool clear_all_soft_refs) /* override */;
242 AdaptiveSizePolicy* size_policy() /* override */;
243 CollectorPolicy* collector_policy() const /* override */;
244 void ensure_parsability(bool retire_tlabs) /* override */;
245 HeapWord* block_start(const void* addr) const /* override */;
246 size_t block_size(const HeapWord* addr) const /* override */;
247 bool block_is_obj(const HeapWord* addr) const /* override */;
248 jlong millis_since_last_gc() /* override */;
249 void prepare_for_verify() /* override */;
250 void print_gc_threads_on(outputStream* st) const /* override */;
251 void gc_threads_do(ThreadClosure* tcl) const /* override */;
252 void print_tracing_info() const /* override */;
253 void verify(VerifyOption vo) /* override */;
254 bool supports_tlab_allocation() const /* override */;
255 size_t tlab_capacity(Thread *thr) const /* override */;
256 void object_iterate(ObjectClosure* cl) /* override */;
257 void safe_object_iterate(ObjectClosure* cl) /* override */;
258 size_t unsafe_max_tlab_alloc(Thread *thread) const /* override */;
259 size_t max_tlab_size() const /* override */;
260 void resize_all_tlabs() /* override */;
261 void accumulate_statistics_all_gclabs() /* override */;
262 HeapWord* tlab_post_allocation_setup(HeapWord* obj) /* override */;
263 uint oop_extra_words() /* override */;
264 size_t tlab_used(Thread* ignored) const /* override */;
265 void stop() /* override */;
266
267 WorkGang* get_safepoint_workers() { return _safepoint_workers; }
268
269 #ifndef CC_INTERP
270 void compile_prepare_oop(MacroAssembler* masm, Register obj) /* override */;
271 #endif
272
273 void register_nmethod(nmethod* nm);
274 void unregister_nmethod(nmethod* nm);
275
276 void pin_object(oop o) /* override */;
277 void unpin_object(oop o) /* override */;
278
279 static ShenandoahHeap* heap();
280 static ShenandoahHeap* heap_no_check();
281 static size_t conservative_max_heap_alignment();
282 static address in_cset_fast_test_addr();
283 static address cancelled_concgc_addr();
284
285 ShenandoahCollectorPolicy *shenandoahPolicy() const { return _shenandoah_policy; }
286 ShenandoahPhaseTimings* phase_timings() const { return _phase_timings; }
287 ShenandoahAllocTracker* alloc_tracker() const { return _alloc_tracker; }
288
289 inline ShenandoahHeapRegion* heap_region_containing(const void* addr) const;
290 inline size_t heap_region_index_containing(const void* addr) const;
291 inline bool requires_marking(const void* entry) const;
292 template <class T>
293 inline oop maybe_update_oop_ref(T* p);
294
295 template <class T>
296 inline oop evac_update_oop_ref(T* p, bool& evac);
297
298 void trash_cset_regions();
299
300 void start_concurrent_marking();
301 void stop_concurrent_marking();
302 inline bool concurrent_mark_in_progress() const;
303 static address concurrent_mark_in_progress_addr();
304
305 void set_concurrent_partial_in_progress(bool in_progress);
306 inline bool is_concurrent_partial_in_progress() const;
307
308 void prepare_for_concurrent_evacuation();
309 void evacuate_and_update_roots();
310 // Fixup roots after concurrent cycle failed
311 void fixup_roots();
312
313 void update_heap_references(ShenandoahHeapRegionSet* regions, bool concurrent);
314 void concurrent_update_heap_references();
315 void prepare_update_refs();
316 void finish_update_refs();
317
318 void roots_iterate(OopClosure* cl);
319
320 private:
321 void set_evacuation_in_progress(bool in_progress);
322
323 public:
324 inline bool is_evacuation_in_progress() const;
325 void set_evacuation_in_progress_concurrently(bool in_progress);
326 void set_evacuation_in_progress_at_safepoint(bool in_progress);
327 static address evacuation_in_progress_addr();
328
329 void set_full_gc_in_progress(bool in_progress);
330 bool is_full_gc_in_progress() const;
331
332 void set_update_refs_in_progress(bool in_progress);
333 bool is_update_refs_in_progress() const;
334 static address update_refs_in_progress_addr();
335
336 inline bool need_update_refs() const;
337 void set_need_update_refs(bool update_refs);
338
339 inline bool region_in_collection_set(size_t region_index) const;
340
341 // Mainly there to avoid accidentally calling the templated
342 // method below with ShenandoahHeapRegion* which would be *wrong*.
343 inline bool in_collection_set(ShenandoahHeapRegion* r) const;
344
345 template <class T>
346 inline bool in_collection_set(T obj) const;
347
348 inline bool allocated_after_next_mark_start(HeapWord* addr) const;
349 void set_next_top_at_mark_start(HeapWord* region_base, HeapWord* addr);
350 HeapWord* next_top_at_mark_start(HeapWord* region_base);
351
352 inline bool allocated_after_complete_mark_start(HeapWord* addr) const;
353 void set_complete_top_at_mark_start(HeapWord* region_base, HeapWord* addr);
354 HeapWord* complete_top_at_mark_start(HeapWord* region_base);
355
356 // Evacuates object src. Returns the evacuated object if this thread
357 // succeeded, otherwise rolls back the evacuation and returns the
358 // evacuated object by the competing thread. 'succeeded' is an out
359 // param and set to true if this thread succeeded, otherwise to false.
360 inline oop evacuate_object(oop src, Thread* thread, bool& evacuated);
361 inline bool cancelled_concgc() const;
362 inline bool check_cancelled_concgc_and_yield(bool sts_active = true);
363 inline bool try_cancel_concgc();
364 inline void clear_cancelled_concgc();
365
366 ShenandoahHeapRegionSet* regions() const { return _ordered_regions;}
367 ShenandoahFreeSet* free_regions() const { return _free_regions; }
368 ShenandoahCollectionSet* collection_set() const { return _collection_set; }
369 void clear_free_regions();
370 void add_free_region(ShenandoahHeapRegion* r);
371
372 ShenandoahConnectionMatrix* connection_matrix() const;
373
374 void increase_used(size_t bytes);
375 void decrease_used(size_t bytes);
376
377 void set_used(size_t bytes);
378
379 void increase_committed(size_t bytes);
380 void decrease_committed(size_t bytes);
381
382 void handle_heap_shrinkage();
383
384 size_t garbage();
385
386 void reset_next_mark_bitmap(WorkGang* gang);
387 void reset_complete_mark_bitmap(WorkGang* gang);
388
389 MarkBitMap* complete_mark_bit_map();
390 MarkBitMap* next_mark_bit_map();
391 inline bool is_marked_complete(oop obj) const;
392 inline bool mark_next(oop obj) const;
393 inline bool is_marked_next(oop obj) const;
394 bool is_next_bitmap_clear();
395 bool is_next_bitmap_clear_range(HeapWord* start, HeapWord* end);
396 bool is_complete_bitmap_clear_range(HeapWord* start, HeapWord* end);
397
398 bool commit_bitmaps(ShenandoahHeapRegion* r);
399 bool uncommit_bitmaps(ShenandoahHeapRegion* r);
400
401 template <class T>
402 inline oop update_oop_ref_not_null(T* p, oop obj);
403
404 template <class T>
405 inline oop maybe_update_oop_ref_not_null(T* p, oop obj);
406
407 void print_heap_regions_on(outputStream* st) const;
408
409 size_t bytes_allocated_since_cm();
410 void set_bytes_allocated_since_cm(size_t bytes);
411
412 size_t trash_humongous_region_at(ShenandoahHeapRegion *r);
413
414 ShenandoahMonitoringSupport* monitoring_support();
415 ShenandoahConcurrentMark* concurrentMark() { return _scm;}
416 ShenandoahPartialGC* partial_gc();
417 ShenandoahVerifier* verifier();
418
419 ReferenceProcessor* ref_processor() { return _ref_processor;}
420
421 WorkGang* workers() const { return _workers;}
422
423 uint max_workers();
424
425 void assert_gc_workers(uint nworker) PRODUCT_RETURN;
426
427 void do_evacuation();
428 ShenandoahHeapRegion* next_compaction_region(const ShenandoahHeapRegion* r);
429
430 void heap_region_iterate(ShenandoahHeapRegionClosure* blk, bool skip_cset_regions = false, bool skip_humongous_continuation = false) const;
431
432 // Delete entries for dead interned string and clean up unreferenced symbols
433 // in symbol table, possibly in parallel.
434 void unload_classes_and_cleanup_tables(bool full_gc);
435
436 inline size_t num_regions() const { return _num_regions; }
437
438 BoolObjectClosure* is_alive_closure();
439
440 private:
441 template<class T>
442 inline void marked_object_iterate(ShenandoahHeapRegion* region, T* cl, HeapWord* limit);
443
444 template<class T>
445 inline void marked_object_oop_iterate(ShenandoahHeapRegion* region, T* cl, HeapWord* limit);
446
447 public:
448 template<class T>
449 inline void marked_object_iterate(ShenandoahHeapRegion* region, T* cl);
450
451 template<class T>
452 inline void marked_object_safe_iterate(ShenandoahHeapRegion* region, T* cl);
453
454 template<class T>
455 inline void marked_object_oop_iterate(ShenandoahHeapRegion* region, T* cl);
456
457 template<class T>
458 inline void marked_object_oop_safe_iterate(ShenandoahHeapRegion* region, T* cl);
459
460 GCTimer* gc_timer() const;
461
462 void swap_mark_bitmaps();
463
464 void cancel_concgc(GCCause::Cause cause);
465 void cancel_concgc(ShenandoahCancelCause cause);
466
467 ShenandoahHeapLock* lock() { return &_lock; }
468 void assert_heaplock_owned_by_current_thread() PRODUCT_RETURN;
469 void assert_heaplock_not_owned_by_current_thread() PRODUCT_RETURN;
470 void assert_heaplock_or_safepoint() PRODUCT_RETURN;
471
472 public:
473 typedef enum {
474 _alloc_shared, // Allocate common, outside of TLAB
475 _alloc_shared_gc, // Allocate common, outside of GCLAB
476 _alloc_tlab, // Allocate TLAB
477 _alloc_gclab, // Allocate GCLAB
478 _ALLOC_LIMIT,
479 } AllocType;
480
481 static const char* alloc_type_to_string(AllocType type) {
482 switch (type) {
483 case _alloc_shared:
484 return "Shared";
485 case _alloc_shared_gc:
486 return "Shared GC";
487 case _alloc_tlab:
488 return "TLAB";
489 case _alloc_gclab:
490 return "GCLAB";
491 default:
492 ShouldNotReachHere();
493 return "";
494 }
495 }
496 private:
497 HeapWord* allocate_new_lab(size_t word_size, AllocType type);
498 HeapWord* allocate_memory_under_lock(size_t word_size, AllocType type, bool &new_region);
499 HeapWord* allocate_memory(size_t word_size, AllocType type);
500 // Shenandoah functionality.
501 inline HeapWord* allocate_from_gclab(Thread* thread, size_t size);
502 HeapWord* allocate_from_gclab_slow(Thread* thread, size_t size);
503 HeapWord* allocate_new_gclab(size_t word_size);
504
505 template<class T>
506 inline void do_marked_object(MarkBitMap* bitmap, T* cl, oop obj);
507
508 ShenandoahConcurrentThread* concurrent_thread() { return _concurrent_gc_thread; }
509
510 inline bool mark_next_no_checks(oop obj) const;
511
512 public:
513 inline oop atomic_compare_exchange_oop(oop n, narrowOop* addr, oop c);
514 inline oop atomic_compare_exchange_oop(oop n, oop* addr, oop c);
515
516 private:
517 void ref_processing_init();
518
519 GCTracer* tracer();
520
521 void set_concurrent_mark_in_progress(bool in_progress);
522
523 void oom_during_evacuation();
524
525 HeapWord* allocate_large_memory(size_t word_size);
526
527 const char* cancel_cause_to_string(ShenandoahCancelCause cause);
528
529 private:
530 size_t* _recycled_regions;
531
532 uint64_t _alloc_seq_at_last_gc_start;
533 uint64_t _alloc_seq_at_last_gc_end;
534 size_t _used_at_last_gc;
535
536 public:
537 void recycle_trash_assist(size_t limit);
538 void recycle_trash();
539
540 uint64_t alloc_seq_at_last_gc_end() const { return _alloc_seq_at_last_gc_end; }
541 uint64_t alloc_seq_at_last_gc_start() const { return _alloc_seq_at_last_gc_start;}
542 size_t used_at_last_gc() const { return _used_at_last_gc;}
543
544 void set_alloc_seq_gc_start();
545 void set_alloc_seq_gc_end();
546
547 void set_used_at_last_gc() {_used_at_last_gc = used();}
548 };
549
550 #endif // SHARE_VM_GC_SHENANDOAH_SHENANDOAHHEAP_HPP