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