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 #include "gc/shenandoah/shenandoahWorkGroup.hpp"
29
30 class ConcurrentGCTimer;
31
32 class ShenandoahCollectorPolicy;
33 class ShenandoahConnectionMatrix;
34 class ShenandoahHeapRegion;
35 class ShenandoahHeapRegionClosure;
36 class ShenandoahHeapRegionSet;
37 class ShenandoahCollectionSet;
38 class ShenandoahFreeSet;
39 class ShenandoahConcurrentMark;
40 class ShenandoahPartialGC;
41 class ShenandoahConcurrentThread;
42 class ShenandoahMonitoringSupport;
43
44 class SCMUpdateRefsClosure: public OopClosure {
45 private:
46 ShenandoahHeap* _heap;
47
48 template <class T>
49 inline void do_oop_work(T* p);
50
51 public:
52 SCMUpdateRefsClosure();
53
54 public:
55 inline void do_oop(oop* p);
56 inline void do_oop(narrowOop* p);
57 };
58
59 #ifdef ASSERT
60 class AssertToSpaceClosure : public OopClosure {
61 private:
62 template <class T>
63 void do_oop_nv(T* p);
64 public:
65 void do_oop(narrowOop* p);
66 void do_oop(oop* p);
67 };
68 #endif
69
70 class ShenandoahAlwaysTrueClosure : public BoolObjectClosure {
71 public:
72 bool do_object_b(oop p) { return true; }
73 };
74
75
76 class ShenandoahForwardedIsAliveClosure: public BoolObjectClosure {
77
78 private:
79 ShenandoahHeap* _heap;
80 public:
81 ShenandoahForwardedIsAliveClosure();
82 void init(ShenandoahHeap* heap);
83 bool do_object_b(oop obj);
84 };
85
86
87 // // A "ShenandoahHeap" is an implementation of a java heap for HotSpot.
88 // // It uses a new pauseless GC algorithm based on Brooks pointers.
89 // // Derived from G1
90
91 // //
92 // // CollectedHeap
93 // // SharedHeap
94 // // ShenandoahHeap
95
96 class ShenandoahHeap : public CollectedHeap {
97 enum LockState { unlocked = 0, locked = 1 };
98
99 public:
100 class ShenandoahHeapLock : public StackObj {
101 private:
102 ShenandoahHeap* _heap;
103
104 public:
105 ShenandoahHeapLock(ShenandoahHeap* heap) : _heap(heap) {
106 while (OrderAccess::load_acquire(& _heap->_heap_lock) == locked || Atomic::cmpxchg(locked, &_heap->_heap_lock, unlocked) == locked) {
107 SpinPause();
108 }
109 assert(_heap->_heap_lock == locked, "sanity");
110
111 #ifdef ASSERT
112 assert(_heap->_heap_lock_owner == NULL, "must not be owned");
113 _heap->_heap_lock_owner = Thread::current();
114 #endif
115 }
116
117 ~ShenandoahHeapLock() {
118 #ifdef ASSERT
119 _heap->assert_heaplock_owned_by_current_thread();
120 _heap->_heap_lock_owner = NULL;
121 #endif
122 OrderAccess::release_store_fence(&_heap->_heap_lock, unlocked);
123 }
124
125 };
126
127 public:
128 enum ShenandoahCancelCause {
129 _oom_evacuation,
130 _vm_stop,
131 };
132 private:
133
134 ShenandoahCollectorPolicy* _shenandoah_policy;
135 VirtualSpace _storage;
136 size_t _bitmap_size;
137 MemRegion _heap_region;
138
139 // Sortable array of regions
140 ShenandoahHeapRegionSet* _ordered_regions;
141 ShenandoahFreeSet* _free_regions;
142 ShenandoahCollectionSet* _collection_set;
143
144 ShenandoahConcurrentMark* _scm;
145 ShenandoahPartialGC* _partial_gc;
146
147 ShenandoahConcurrentThread* _concurrent_gc_thread;
148
149 ShenandoahMonitoringSupport* _monitoring_support;
150
151 size_t _num_regions;
152 size_t _max_regions;
153 size_t _initialSize;
154
155 uint _max_workers;
156 ShenandoahWorkGang* _workers;
157
158 volatile size_t _used;
159
160 CMBitMap _verification_bit_map;
161 CMBitMap _mark_bit_map0;
162 CMBitMap _mark_bit_map1;
163 CMBitMap* _complete_mark_bit_map;
164 CMBitMap* _next_mark_bit_map;
165
166 bool* _in_cset_fast_test;
167 bool* _in_cset_fast_test_base;
168 size_t _in_cset_fast_test_length;
169
170 HeapWord** _complete_top_at_mark_starts;
171 HeapWord** _complete_top_at_mark_starts_base;
172
173 HeapWord** _next_top_at_mark_starts;
174 HeapWord** _next_top_at_mark_starts_base;
175
176 volatile jbyte _cancelled_concgc;
177
178 size_t _bytes_allocated_since_cm;
179 size_t _bytes_allocated_during_cm;
180 size_t _allocated_last_gc;
181 size_t _used_start_gc;
182
183 unsigned int _concurrent_mark_in_progress;
184
185 bool _full_gc_in_progress;
186 bool _update_refs_in_progress;
187
188 unsigned int _evacuation_in_progress;
189 bool _need_update_refs;
190 bool _need_reset_bitmaps;
191
192 ReferenceProcessor* _ref_processor;
193
194 ShenandoahForwardedIsAliveClosure isAlive;
195
196 ConcurrentGCTimer* _gc_timer;
197
198 // See allocate_memory()
199 volatile jbyte _heap_lock;
200
201 ShenandoahConnectionMatrix* _connection_matrix;
202
203 #ifdef ASSERT
204 Thread* volatile _heap_lock_owner;
205 #endif
206
207 public:
208 ShenandoahHeap(ShenandoahCollectorPolicy* policy);
209
210 const char* name() const /* override */;
211 HeapWord* allocate_new_tlab(size_t word_size) /* override */;
212 void print_on(outputStream* st) const /* override */;
213
214 ShenandoahHeap::Name kind() const /* override */{
215 return CollectedHeap::ShenandoahHeap;
216 }
217
218 jint initialize() /* override */;
219 void post_initialize() /* override */;
220 size_t capacity() const /* override */;
221 size_t used() const /* override */;
222 bool is_maximal_no_gc() const /* override */;
223 size_t max_capacity() const /* override */;
224 size_t min_capacity() const /* override */;
225 bool is_in(const void* p) const /* override */;
226 bool is_scavengable(const void* addr) /* override */;
227 HeapWord* mem_allocate(size_t size, bool* what) /* override */;
228 bool can_elide_tlab_store_barriers() const /* override */;
229 oop new_store_pre_barrier(JavaThread* thread, oop new_obj) /* override */;
230 bool can_elide_initializing_store_barrier(oop new_obj) /* override */;
231 bool card_mark_must_follow_store() const /* override */;
232 void collect(GCCause::Cause) /* override */;
233 void do_full_collection(bool clear_all_soft_refs) /* override */;
234 AdaptiveSizePolicy* size_policy() /* override */;
235 CollectorPolicy* collector_policy() const /* override */;
236 void ensure_parsability(bool retire_tlabs) /* override */;
237 HeapWord* block_start(const void* addr) const /* override */;
238 size_t block_size(const HeapWord* addr) const /* override */;
239 bool block_is_obj(const HeapWord* addr) const /* override */;
240 jlong millis_since_last_gc() /* override */;
241 void prepare_for_verify() /* override */;
242 void print_gc_threads_on(outputStream* st) const /* override */;
243 void gc_threads_do(ThreadClosure* tcl) const /* override */;
244 void print_tracing_info() const /* override */;
245 void verify(VerifyOption vo) /* override */;
246 bool supports_tlab_allocation() const /* override */;
247 size_t tlab_capacity(Thread *thr) const /* override */;
248 void object_iterate(ObjectClosure* cl) /* override */;
249 void safe_object_iterate(ObjectClosure* cl) /* override */;
250 size_t unsafe_max_tlab_alloc(Thread *thread) const /* override */;
251 size_t max_tlab_size() const /* override */;
252 void resize_all_tlabs() /* override */;
253 void accumulate_statistics_all_gclabs() /* override */;
254 HeapWord* tlab_post_allocation_setup(HeapWord* obj) /* override */;
255 uint oop_extra_words() /* override */;
256 size_t tlab_used(Thread* ignored) const /* override */;
257 void stop() /* override */;
258
259 #ifndef CC_INTERP
260 void compile_prepare_oop(MacroAssembler* masm, Register obj) /* override */;
261 #endif
262
263 void register_nmethod(nmethod* nm);
264 void unregister_nmethod(nmethod* nm);
265
266 void pin_object(oop o) /* override */;
267 void unpin_object(oop o) /* override */;
268
269 static ShenandoahHeap* heap();
270 static ShenandoahHeap* heap_no_check();
271 static size_t conservative_max_heap_alignment();
272 static address in_cset_fast_test_addr();
273 static address cancelled_concgc_addr();
274
275 ShenandoahCollectorPolicy *shenandoahPolicy() { return _shenandoah_policy;}
276
277 inline ShenandoahHeapRegion* heap_region_containing(const void* addr) const;
278 inline size_t heap_region_index_containing(const void* addr) const;
279 inline bool requires_marking(const void* entry) const;
280 template <class T>
281 inline oop maybe_update_oop_ref(T* p);
282
283 void recycle_dirty_regions();
284
285 void start_concurrent_marking();
286 void stop_concurrent_marking();
287 inline bool concurrent_mark_in_progress();
288 static address concurrent_mark_in_progress_addr();
289
290 void prepare_for_concurrent_evacuation();
291 void evacuate_and_update_roots();
292
293 void do_partial_collection();
294
295 void update_heap_references(ShenandoahHeapRegionSet* regions);
296 void concurrent_update_heap_references();
297 void prepare_update_refs();
298 void finish_update_refs();
299 void verify_update_refs();
300
301 private:
302 void set_evacuation_in_progress(bool in_progress);
303 public:
304 inline bool is_evacuation_in_progress();
305 void set_evacuation_in_progress_concurrently(bool in_progress);
306 void set_evacuation_in_progress_at_safepoint(bool in_progress);
307
308 void set_full_gc_in_progress(bool in_progress);
309 bool is_full_gc_in_progress() const;
310
311 void set_update_refs_in_progress(bool in_progress);
312 bool is_update_refs_in_progress() const;
313 static address update_refs_in_progress_addr();
314
315 inline bool need_update_refs() const;
316 void set_need_update_refs(bool update_refs);
317
318 inline bool region_in_collection_set(size_t region_index) const;
319
320 void set_region_in_collection_set(size_t region_index, bool b);
321
322 // Mainly there to avoid accidentally calling the templated
323 // method below with ShenandoahHeapRegion* which would be *wrong*.
324 inline bool in_collection_set(ShenandoahHeapRegion* r) const;
325
326 template <class T>
327 inline bool in_collection_set(T obj) const;
328
329 void clear_cset_fast_test();
330
331 inline bool allocated_after_next_mark_start(HeapWord* addr) const;
332 void set_next_top_at_mark_start(HeapWord* region_base, HeapWord* addr);
333 HeapWord* next_top_at_mark_start(HeapWord* region_base);
334
335 inline bool allocated_after_complete_mark_start(HeapWord* addr) const;
336 void set_complete_top_at_mark_start(HeapWord* region_base, HeapWord* addr);
337 HeapWord* complete_top_at_mark_start(HeapWord* region_base);
338
339 // Evacuates object src. Returns the evacuated object if this thread
340 // succeeded, otherwise rolls back the evacuation and returns the
341 // evacuated object by the competing thread. 'succeeded' is an out
342 // param and set to true if this thread succeeded, otherwise to false.
343 inline oop evacuate_object(oop src, Thread* thread, bool& evacuated);
344 inline bool cancelled_concgc() const;
345 inline bool try_cancel_concgc();
346 inline void clear_cancelled_concgc();
347
348 ShenandoahHeapRegionSet* regions() { return _ordered_regions;}
349 ShenandoahFreeSet* free_regions();
350 ShenandoahCollectionSet* collection_set() { return _collection_set; }
351 void clear_free_regions();
352 void add_free_region(ShenandoahHeapRegion* r);
353
354 ShenandoahConnectionMatrix* connection_matrix();
355
356 void increase_used(size_t bytes);
357 void decrease_used(size_t bytes);
358
359 void set_used(size_t bytes);
360 size_t calculateUsed();
361
362 size_t garbage();
363
364 void reset_next_mark_bitmap(WorkGang* gang);
365 void reset_complete_mark_bitmap(WorkGang* gang);
366
367 CMBitMap* complete_mark_bit_map();
368 CMBitMap* next_mark_bit_map();
369 inline bool is_marked_complete(oop obj) const;
370 inline bool mark_next(oop obj) const;
371 inline bool is_marked_next(oop obj) const;
372 bool is_next_bitmap_clear();
373 bool is_complete_bitmap_clear_range(HeapWord* start, HeapWord* end);
374
375 void parallel_evacuate_region(ShenandoahHeapRegion* from_region);
376
377 template <class T>
378 inline oop update_oop_ref_not_null(T* p, oop obj);
379
380 template <class T>
381 inline oop maybe_update_oop_ref_not_null(T* p, oop obj);
382
383 void print_heap_regions(outputStream* st = tty) const;
384 void print_all_refs(const char* prefix);
385 void print_heap_locations(HeapWord* start, HeapWord* end);
386
387 size_t bytes_allocated_since_cm();
388 void set_bytes_allocated_since_cm(size_t bytes);
389
390 void reclaim_humongous_region_at(ShenandoahHeapRegion* r);
391
392 VirtualSpace* storage() const;
393
394 ShenandoahMonitoringSupport* monitoring_support();
395 ShenandoahConcurrentMark* concurrentMark() { return _scm;}
396 ShenandoahPartialGC* partial_gc();
397
398 ReferenceProcessor* ref_processor() { return _ref_processor;}
399
400 WorkGang* workers() const { return _workers;}
401
402 uint max_workers();
403
404 void do_evacuation();
405 ShenandoahHeapRegion* next_compaction_region(const ShenandoahHeapRegion* r);
406
407 void heap_region_iterate(ShenandoahHeapRegionClosure* blk, bool skip_dirty_regions = false, bool skip_humongous_continuation = false) const;
408
409 void verify_heap_after_evacuation();
410 void verify_heap_after_marking();
411 void verify_heap_reachable_at_safepoint();
412
413 // Delete entries for dead interned string and clean up unreferenced symbols
414 // in symbol table, possibly in parallel.
415 void unload_classes_and_cleanup_tables();
416
417 size_t num_regions();
418 size_t max_regions();
419
420 // TODO: consider moving this into ShenandoahHeapRegion.
421
422 private:
423 template<class T>
424 inline void marked_object_iterate(ShenandoahHeapRegion* region, T* cl, HeapWord* limit);
425
426 template<class T>
427 inline void marked_object_oop_iterate(ShenandoahHeapRegion* region, T* cl, HeapWord* limit);
428
429 public:
430 template<class T>
431 inline void marked_object_iterate(ShenandoahHeapRegion* region, T* cl);
432
433 template<class T>
434 inline void marked_object_safe_iterate(ShenandoahHeapRegion* region, T* cl);
435
436 template<class T>
437 inline void marked_object_oop_iterate(ShenandoahHeapRegion* region, T* cl);
438
439 template<class T>
440 inline void marked_object_oop_safe_iterate(ShenandoahHeapRegion* region, T* cl);
441
442 GCTimer* gc_timer() const;
443
444 void swap_mark_bitmaps();
445
446 void cancel_concgc(GCCause::Cause cause);
447 void cancel_concgc(ShenandoahCancelCause cause);
448
449 void assert_heaplock_owned_by_current_thread() PRODUCT_RETURN;
450 void assert_heaplock_or_safepoint() PRODUCT_RETURN;
451
452 public:
453 typedef enum {
454 _lab_thread,
455 _lab_gc,
456 } LabType;
457 private:
458 HeapWord* allocate_new_lab(size_t word_size, LabType type);
459 HeapWord* allocate_memory_under_lock(size_t word_size, LabType type);
460 HeapWord* allocate_memory(size_t word_size, LabType type);
461 // Shenandoah functionality.
462 inline HeapWord* allocate_from_gclab(Thread* thread, size_t size);
463 HeapWord* allocate_from_gclab_slow(Thread* thread, size_t size);
464 HeapWord* allocate_new_gclab(size_t word_size);
465
466 void roots_iterate(OopClosure* cl);
467
468 template<class T>
469 inline void do_marked_object(CMBitMap* bitmap, T* cl, oop obj);
470
471 ShenandoahConcurrentThread* concurrent_thread() { return _concurrent_gc_thread; }
472
473 inline bool mark_next_no_checks(oop obj) const;
474
475 void parallel_evacuate();
476
477 public:
478 inline oop atomic_compare_exchange_oop(oop n, narrowOop* addr, oop c);
479 inline oop atomic_compare_exchange_oop(oop n, oop* addr, oop c);
480
481 private:
482 #ifdef ASSERT
483 void verify_evacuated_region(ShenandoahHeapRegion* from_region);
484 #endif
485
486 inline void copy_object(oop p, HeapWord* s, size_t words);
487 void verify_copy(oop p, oop c);
488 void verify_heap_size_consistency();
489 private:
490 void ref_processing_init();
491
492 GCTracer* tracer();
493
494 void grow_heap_by(size_t num_regions);
495 void ensure_new_regions(size_t num_new_regions);
496
497 void verify_evacuation(ShenandoahHeapRegion* from_region);
498 void set_concurrent_mark_in_progress(bool in_progress);
499
500 void oom_during_evacuation();
501
502 HeapWord* allocate_memory_work(size_t word_size, LabType type);
503 HeapWord* allocate_large_memory(size_t word_size);
504
505 const char* cancel_cause_to_string(ShenandoahCancelCause cause);
506
507 private:
508 size_t* _recycled_regions;
509 size_t _recycled_region_count;
510
511 public:
512 void start_deferred_recycling();
513 void defer_recycle(ShenandoahHeapRegion* r);
514 void finish_deferred_recycle();
515
516 bool supports_per_thread_monitor_deflation() const {
517 return true;
518 }
519
520 void deflate_idle_monitors_all_threads();
521 };
522
523 #endif // SHARE_VM_GC_SHENANDOAH_SHENANDOAHHEAP_HPP