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 unsigned int _concurrent_mark_in_progress;
187
188 bool _full_gc_in_progress;
189 bool _update_refs_in_progress;
190
191 unsigned int _evacuation_in_progress;
192 bool _need_update_refs;
193 bool _need_reset_bitmaps;
194
195 ReferenceProcessor* _ref_processor;
196
197 ShenandoahForwardedIsAliveClosure _forwarded_is_alive;
198 ShenandoahIsAliveClosure _is_alive;
199
200 ConcurrentGCTimer* _gc_timer;
201
202 // See allocate_memory()
203 volatile jbyte _heap_lock;
204
205 ShenandoahConnectionMatrix* _connection_matrix;
206
207 #ifdef ASSERT
208 Thread* volatile _heap_lock_owner;
209 int _heap_expansion_count;
210 #endif
211
212 public:
213 ShenandoahHeap(ShenandoahCollectorPolicy* policy);
214
215 const char* name() const /* override */;
216 HeapWord* allocate_new_tlab(size_t word_size) /* override */;
217 void print_on(outputStream* st) const /* override */;
218 void print_extended_on(outputStream *st) const /* override */;
219
220 ShenandoahHeap::Name kind() const /* override */{
221 return CollectedHeap::ShenandoahHeap;
222 }
223
224 jint initialize() /* override */;
225 void post_initialize() /* override */;
226 size_t capacity() const /* override */;
227 size_t used() const /* override */;
228 size_t committed() const;
229 bool is_maximal_no_gc() const /* override */;
230 size_t max_capacity() const /* override */;
231 size_t initial_capacity() const /* override */;
232 bool is_in(const void* p) const /* override */;
233 bool is_scavengable(const void* addr) /* override */;
234 HeapWord* mem_allocate(size_t size, bool* what) /* override */;
235 bool can_elide_tlab_store_barriers() const /* override */;
236 oop new_store_pre_barrier(JavaThread* thread, oop new_obj) /* override */;
237 bool can_elide_initializing_store_barrier(oop new_obj) /* override */;
238 bool card_mark_must_follow_store() const /* override */;
239 void collect(GCCause::Cause cause) /* override */;
240 void do_full_collection(bool clear_all_soft_refs) /* override */;
241 AdaptiveSizePolicy* size_policy() /* override */;
242 CollectorPolicy* collector_policy() const /* override */;
243 void ensure_parsability(bool retire_tlabs) /* override */;
244 HeapWord* block_start(const void* addr) const /* override */;
245 size_t block_size(const HeapWord* addr) const /* override */;
246 bool block_is_obj(const HeapWord* addr) const /* override */;
247 jlong millis_since_last_gc() /* override */;
248 void prepare_for_verify() /* override */;
249 void print_gc_threads_on(outputStream* st) const /* override */;
250 void gc_threads_do(ThreadClosure* tcl) const /* override */;
251 void print_tracing_info() const /* override */;
252 void verify(VerifyOption vo) /* override */;
253 bool supports_tlab_allocation() const /* override */;
254 size_t tlab_capacity(Thread *thr) const /* override */;
255 void object_iterate(ObjectClosure* cl) /* override */;
256 void safe_object_iterate(ObjectClosure* cl) /* override */;
257 size_t unsafe_max_tlab_alloc(Thread *thread) const /* override */;
258 size_t max_tlab_size() const /* override */;
259 void resize_all_tlabs() /* override */;
260 void accumulate_statistics_all_gclabs() /* override */;
261 HeapWord* tlab_post_allocation_setup(HeapWord* obj) /* override */;
262 uint oop_extra_words() /* override */;
263 size_t tlab_used(Thread* ignored) const /* override */;
264 void stop() /* override */;
265
266 WorkGang* get_safepoint_workers() { return _safepoint_workers; }
267
268 #ifndef CC_INTERP
269 void compile_prepare_oop(MacroAssembler* masm, Register obj) /* override */;
270 #endif
271
272 void register_nmethod(nmethod* nm);
273 void unregister_nmethod(nmethod* nm);
274
275 void pin_object(oop o) /* override */;
276 void unpin_object(oop o) /* override */;
277
278 static ShenandoahHeap* heap();
279 static ShenandoahHeap* heap_no_check();
280 static size_t conservative_max_heap_alignment();
281 static address in_cset_fast_test_addr();
282 static address cancelled_concgc_addr();
283
284 ShenandoahCollectorPolicy *shenandoahPolicy() const { return _shenandoah_policy; }
285 ShenandoahPhaseTimings* phase_timings() const { return _phase_timings; }
286 ShenandoahAllocTracker* alloc_tracker() const { return _alloc_tracker; }
287
288 inline ShenandoahHeapRegion* heap_region_containing(const void* addr) const;
289 inline size_t heap_region_index_containing(const void* addr) const;
290 inline bool requires_marking(const void* entry) const;
291 template <class T>
292 inline oop maybe_update_oop_ref(T* p);
293
294 void trash_cset_regions();
295
296 void start_concurrent_marking();
297 void stop_concurrent_marking();
298 inline bool concurrent_mark_in_progress() const;
299 static address concurrent_mark_in_progress_addr();
300
301 void prepare_for_concurrent_evacuation();
302 void evacuate_and_update_roots();
303 // Fixup roots after concurrent cycle failed
304 void fixup_roots();
305
306 void do_partial_collection();
307
308 void update_heap_references(ShenandoahHeapRegionSet* regions, bool concurrent);
309 void concurrent_update_heap_references();
310 void prepare_update_refs();
311 void finish_update_refs();
312
313 void roots_iterate(OopClosure* cl);
314
315 private:
316 void set_evacuation_in_progress(bool in_progress);
317
318 public:
319 inline bool is_evacuation_in_progress() const;
320 void set_evacuation_in_progress_concurrently(bool in_progress);
321 void set_evacuation_in_progress_at_safepoint(bool in_progress);
322 static address evacuation_in_progress_addr();
323
324 void set_full_gc_in_progress(bool in_progress);
325 bool is_full_gc_in_progress() const;
326
327 void set_update_refs_in_progress(bool in_progress);
328 bool is_update_refs_in_progress() const;
329 static address update_refs_in_progress_addr();
330
331 inline bool need_update_refs() const;
332 void set_need_update_refs(bool update_refs);
333
334 inline bool region_in_collection_set(size_t region_index) const;
335
336 // Mainly there to avoid accidentally calling the templated
337 // method below with ShenandoahHeapRegion* which would be *wrong*.
338 inline bool in_collection_set(ShenandoahHeapRegion* r) const;
339
340 template <class T>
341 inline bool in_collection_set(T obj) const;
342
343 inline bool allocated_after_next_mark_start(HeapWord* addr) const;
344 void set_next_top_at_mark_start(HeapWord* region_base, HeapWord* addr);
345 HeapWord* next_top_at_mark_start(HeapWord* region_base);
346
347 inline bool allocated_after_complete_mark_start(HeapWord* addr) const;
348 void set_complete_top_at_mark_start(HeapWord* region_base, HeapWord* addr);
349 HeapWord* complete_top_at_mark_start(HeapWord* region_base);
350
351 // Evacuates object src. Returns the evacuated object if this thread
352 // succeeded, otherwise rolls back the evacuation and returns the
353 // evacuated object by the competing thread. 'succeeded' is an out
354 // param and set to true if this thread succeeded, otherwise to false.
355 inline oop evacuate_object(oop src, Thread* thread, bool& evacuated);
356 inline bool cancelled_concgc() const;
357 inline bool check_cancelled_concgc_and_yield(bool sts_active = true);
358 inline bool try_cancel_concgc();
359 inline void clear_cancelled_concgc();
360
361 ShenandoahHeapRegionSet* regions() const { return _ordered_regions;}
362 ShenandoahFreeSet* free_regions() const { return _free_regions; }
363 ShenandoahCollectionSet* collection_set() const { return _collection_set; }
364 void clear_free_regions();
365 void add_free_region(ShenandoahHeapRegion* r);
366
367 ShenandoahConnectionMatrix* connection_matrix() const;
368
369 void increase_used(size_t bytes);
370 void decrease_used(size_t bytes);
371
372 void set_used(size_t bytes);
373
374 void increase_committed(size_t bytes);
375 void decrease_committed(size_t bytes);
376
377 void handle_heap_shrinkage();
378
379 size_t garbage();
380
381 void reset_next_mark_bitmap(WorkGang* gang);
382 void reset_complete_mark_bitmap(WorkGang* gang);
383
384 MarkBitMap* complete_mark_bit_map();
385 MarkBitMap* next_mark_bit_map();
386 inline bool is_marked_complete(oop obj) const;
387 inline bool mark_next(oop obj) const;
388 inline bool is_marked_next(oop obj) const;
389 bool is_next_bitmap_clear();
390 bool is_next_bitmap_clear_range(HeapWord* start, HeapWord* end);
391 bool is_complete_bitmap_clear_range(HeapWord* start, HeapWord* end);
392
393 bool commit_bitmaps(ShenandoahHeapRegion* r);
394 bool uncommit_bitmaps(ShenandoahHeapRegion* r);
395
396 template <class T>
397 inline oop update_oop_ref_not_null(T* p, oop obj);
398
399 template <class T>
400 inline oop maybe_update_oop_ref_not_null(T* p, oop obj);
401
402 void print_heap_regions_on(outputStream* st) const;
403
404 size_t bytes_allocated_since_cm();
405 void set_bytes_allocated_since_cm(size_t bytes);
406
407 size_t trash_humongous_region_at(ShenandoahHeapRegion *r);
408
409 ShenandoahMonitoringSupport* monitoring_support();
410 ShenandoahConcurrentMark* concurrentMark() { return _scm;}
411 ShenandoahPartialGC* partial_gc();
412 ShenandoahVerifier* verifier();
413
414 ReferenceProcessor* ref_processor() { return _ref_processor;}
415
416 WorkGang* workers() const { return _workers;}
417
418 uint max_workers();
419
420 void assert_gc_workers(uint nworker) PRODUCT_RETURN;
421
422 void do_evacuation();
423 ShenandoahHeapRegion* next_compaction_region(const ShenandoahHeapRegion* r);
424
425 void heap_region_iterate(ShenandoahHeapRegionClosure* blk, bool skip_cset_regions = false, bool skip_humongous_continuation = false) const;
426
427 // Delete entries for dead interned string and clean up unreferenced symbols
428 // in symbol table, possibly in parallel.
429 void unload_classes_and_cleanup_tables(bool full_gc);
430
431 inline size_t num_regions() const { return _num_regions; }
432
433 BoolObjectClosure* is_alive_closure();
434
435 private:
436 template<class T>
437 inline void marked_object_iterate(ShenandoahHeapRegion* region, T* cl, HeapWord* limit);
438
439 template<class T>
440 inline void marked_object_oop_iterate(ShenandoahHeapRegion* region, T* cl, HeapWord* limit);
441
442 public:
443 template<class T>
444 inline void marked_object_iterate(ShenandoahHeapRegion* region, T* cl);
445
446 template<class T>
447 inline void marked_object_safe_iterate(ShenandoahHeapRegion* region, T* cl);
448
449 template<class T>
450 inline void marked_object_oop_iterate(ShenandoahHeapRegion* region, T* cl);
451
452 template<class T>
453 inline void marked_object_oop_safe_iterate(ShenandoahHeapRegion* region, T* cl);
454
455 GCTimer* gc_timer() const;
456
457 void swap_mark_bitmaps();
458
459 void cancel_concgc(GCCause::Cause cause);
460 void cancel_concgc(ShenandoahCancelCause cause);
461
462 ShenandoahHeapLock* lock() { return &_lock; }
463 void assert_heaplock_owned_by_current_thread() PRODUCT_RETURN;
464 void assert_heaplock_not_owned_by_current_thread() PRODUCT_RETURN;
465 void assert_heaplock_or_safepoint() PRODUCT_RETURN;
466
467 public:
468 typedef enum {
469 _alloc_shared, // Allocate common, outside of TLAB
470 _alloc_shared_gc, // Allocate common, outside of GCLAB
471 _alloc_tlab, // Allocate TLAB
472 _alloc_gclab, // Allocate GCLAB
473 _ALLOC_LIMIT,
474 } AllocType;
475
476 static const char* alloc_type_to_string(AllocType type) {
477 switch (type) {
478 case _alloc_shared:
479 return "Shared";
480 case _alloc_shared_gc:
481 return "Shared GC";
482 case _alloc_tlab:
483 return "TLAB";
484 case _alloc_gclab:
485 return "GCLAB";
486 default:
487 ShouldNotReachHere();
488 return "";
489 }
490 }
491 private:
492 HeapWord* allocate_new_lab(size_t word_size, AllocType type);
493 HeapWord* allocate_memory_under_lock(size_t word_size, AllocType type, bool &new_region);
494 HeapWord* allocate_memory(size_t word_size, AllocType type);
495 // Shenandoah functionality.
496 inline HeapWord* allocate_from_gclab(Thread* thread, size_t size);
497 HeapWord* allocate_from_gclab_slow(Thread* thread, size_t size);
498 HeapWord* allocate_new_gclab(size_t word_size);
499
500 template<class T>
501 inline void do_marked_object(MarkBitMap* bitmap, T* cl, oop obj);
502
503 ShenandoahConcurrentThread* concurrent_thread() { return _concurrent_gc_thread; }
504
505 inline bool mark_next_no_checks(oop obj) const;
506
507 public:
508 inline oop atomic_compare_exchange_oop(oop n, narrowOop* addr, oop c);
509 inline oop atomic_compare_exchange_oop(oop n, oop* addr, oop c);
510
511 private:
512 void ref_processing_init();
513
514 GCTracer* tracer();
515
516 void set_concurrent_mark_in_progress(bool in_progress);
517
518 void oom_during_evacuation();
519
520 HeapWord* allocate_large_memory(size_t word_size);
521
522 const char* cancel_cause_to_string(ShenandoahCancelCause cause);
523
524 private:
525 size_t* _recycled_regions;
526
527 uint64_t _alloc_seq_at_last_gc_start;
528 uint64_t _alloc_seq_at_last_gc_end;
529 size_t _used_at_last_gc;
530
531 public:
532 void recycle_trash_assist(size_t limit);
533 void recycle_trash();
534
535 uint64_t alloc_seq_at_last_gc_end() const { return _alloc_seq_at_last_gc_end; }
536 uint64_t alloc_seq_at_last_gc_start() const { return _alloc_seq_at_last_gc_start;}
537 size_t used_at_last_gc() const { return _used_at_last_gc;}
538
539 void set_alloc_seq_gc_start();
540 void set_alloc_seq_gc_end();
541
542 void set_used_at_last_gc() {_used_at_last_gc = used();}
543 };
544
545 #endif // SHARE_VM_GC_SHENANDOAH_SHENANDOAHHEAP_HPP