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 static ShenandoahHeap* _pgc; 135 ShenandoahCollectorPolicy* _shenandoah_policy; 136 VirtualSpace _storage; 137 ShenandoahHeapRegion* _first_region; 138 HeapWord* _first_region_bottom; 139 140 // Sortable array of regions 141 ShenandoahHeapRegionSet* _ordered_regions; 142 ShenandoahHeapRegionSet* _sorted_regions; 143 ShenandoahFreeSet* _free_regions; 144 ShenandoahCollectionSet* _collection_set; 145 146 ShenandoahHeapRegion* _currentAllocationRegion; 147 ShenandoahConcurrentMark* _scm; 148 ShenandoahPartialGC* _partial_gc; 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 do_partial_collection(); 303 void verify_matrix(); 304 private: 305 void set_evacuation_in_progress(bool in_progress); 306 public: 307 inline bool is_evacuation_in_progress(); 308 void set_evacuation_in_progress_concurrently(bool in_progress); 309 void set_evacuation_in_progress_at_safepoint(bool in_progress); 310 311 void set_full_gc_in_progress(bool in_progress); 312 bool is_full_gc_in_progress() const; 313 314 inline bool need_update_refs() const; 315 void set_need_update_refs(bool update_refs); 316 317 inline bool region_in_collection_set(size_t region_index) const; 318 319 void set_region_in_collection_set(size_t region_index, bool b); 320 321 // Mainly there to avoid accidentally calling the templated 322 // method below with ShenandoahHeapRegion* which would be *wrong*. 323 inline bool in_collection_set(ShenandoahHeapRegion* r) const; 324 325 template <class T> 326 inline bool in_collection_set(T obj) const; 327 328 void clear_cset_fast_test(); 329 330 inline bool allocated_after_next_mark_start(HeapWord* addr) const; 331 void set_next_top_at_mark_start(HeapWord* region_base, HeapWord* addr); 332 HeapWord* next_top_at_mark_start(HeapWord* region_base); 333 334 inline bool allocated_after_complete_mark_start(HeapWord* addr) const; 335 void set_complete_top_at_mark_start(HeapWord* region_base, HeapWord* addr); 336 HeapWord* complete_top_at_mark_start(HeapWord* region_base); 337 338 inline oop evacuate_object(oop src, Thread* thread); 339 inline bool cancelled_concgc() const; 340 inline void set_cancelled_concgc(bool v); 341 inline bool try_cancel_concgc() const; 342 void clear_cancelled_concgc(); 343 344 ShenandoahHeapRegionSet* regions() { return _ordered_regions;} 345 ShenandoahFreeSet* free_regions(); 346 ShenandoahCollectionSet* collection_set() { return _collection_set; } 347 void clear_free_regions(); 348 void add_free_region(ShenandoahHeapRegion* r); 349 350 ShenandoahConnectionMatrix* connection_matrix(); 351 352 void increase_used(size_t bytes); 353 void decrease_used(size_t bytes); 354 355 void set_used(size_t bytes); 356 size_t calculateUsed(); 357 358 size_t garbage(); 359 360 void reset_next_mark_bitmap(WorkGang* gang); 361 void reset_complete_mark_bitmap(WorkGang* gang); 362 363 CMBitMap* complete_mark_bit_map(); 364 CMBitMap* next_mark_bit_map(); 365 inline bool is_marked_complete(oop obj) const; 366 inline bool mark_next(oop obj) const; 367 inline bool is_marked_next(oop obj) const; 368 bool is_next_bitmap_clear(); 369 bool is_complete_bitmap_clear_range(HeapWord* start, HeapWord* end); 370 371 void parallel_evacuate_region(ShenandoahHeapRegion* from_region); 372 373 template <class T> 374 inline oop update_oop_ref_not_null(T* p, oop obj); 375 376 template <class T> 377 inline oop maybe_update_oop_ref_not_null(T* p, oop obj); 378 379 void print_heap_regions(outputStream* st = tty) const; 380 void print_all_refs(const char* prefix); 381 void print_heap_locations(HeapWord* start, HeapWord* end); 382 383 void calculate_matrix(int* connections); 384 void print_matrix(int* connections); 385 386 size_t bytes_allocated_since_cm(); 387 void set_bytes_allocated_since_cm(size_t bytes); 388 389 size_t max_allocated_gc(); 390 391 void reclaim_humongous_region_at(ShenandoahHeapRegion* r); 392 393 VirtualSpace* storage() const; 394 395 ShenandoahMonitoringSupport* monitoring_support(); 396 ShenandoahConcurrentMark* concurrentMark() { return _scm;} 397 ShenandoahPartialGC* partial_gc(); 398 399 ReferenceProcessor* ref_processor() { return _ref_processor;} 400 401 WorkGang* workers() const { return _workers;} 402 403 uint max_workers(); 404 405 void do_evacuation(); 406 ShenandoahHeapRegion* next_compaction_region(const ShenandoahHeapRegion* r); 407 408 void heap_region_iterate(ShenandoahHeapRegionClosure* blk, bool skip_dirty_regions = false, bool skip_humongous_continuation = false) const; 409 410 void verify_heap_after_evacuation(); 411 void verify_heap_after_marking(); 412 413 // Delete entries for dead interned string and clean up unreferenced symbols 414 // in symbol table, possibly in parallel. 415 void unlink_string_and_symbol_table(BoolObjectClosure* is_alive, bool unlink_strings = true, bool unlink_symbols = true); 416 417 size_t num_regions(); 418 size_t max_regions(); 419 420 // TODO: consider moving this into ShenandoahHeapRegion. 421 422 template<class T> 423 inline void marked_object_iterate(ShenandoahHeapRegion* region, T* cl); 424 425 GCTimer* gc_timer() const; 426 427 void swap_mark_bitmaps(); 428 429 void cancel_concgc(GCCause::Cause cause); 430 void cancel_concgc(ShenandoahCancelCause cause); 431 432 void assert_heaplock_owned_by_current_thread() PRODUCT_RETURN; 433 void assert_heaplock_or_safepoint() PRODUCT_RETURN; 434 435 private: 436 HeapWord* allocate_new_tlab(size_t word_size, bool mark); 437 HeapWord* allocate_memory_under_lock(size_t word_size); 438 HeapWord* allocate_memory(size_t word_size, bool evacuating); 439 // Shenandoah functionality. 440 inline HeapWord* allocate_from_gclab(Thread* thread, size_t size); 441 HeapWord* allocate_from_gclab_slow(Thread* thread, size_t size); 442 HeapWord* allocate_new_gclab(size_t word_size); 443 444 void roots_iterate(OopClosure* cl); 445 446 template<class T> 447 inline void do_marked_object(CMBitMap* bitmap, T* cl, oop obj); 448 449 ShenandoahConcurrentThread* concurrent_thread() { return _concurrent_gc_thread; } 450 451 inline bool mark_next_no_checks(oop obj) const; 452 453 void parallel_evacuate(); 454 455 public: 456 inline oop atomic_compare_exchange_oop(oop n, narrowOop* addr, oop c); 457 inline oop atomic_compare_exchange_oop(oop n, oop* addr, oop c); 458 459 private: 460 void evacuate_region(ShenandoahHeapRegion* from_region, ShenandoahHeapRegion* to_region); 461 462 #ifdef ASSERT 463 void verify_evacuated_region(ShenandoahHeapRegion* from_region); 464 #endif 465 466 inline void copy_object(oop p, HeapWord* s, size_t words); 467 void verify_copy(oop p, oop c); 468 void verify_heap_size_consistency(); 469 private: 470 void verify_heap_after_update_refs(); 471 void verify_regions_after_update_refs(); 472 473 void ref_processing_init(); 474 475 GCTracer* tracer(); 476 477 bool call_from_write_barrier(bool evacuating); 478 void grow_heap_by(size_t num_regions); 479 void ensure_new_regions(size_t num_new_regions); 480 481 void verify_evacuation(ShenandoahHeapRegion* from_region); 482 void set_concurrent_mark_in_progress(bool in_progress); 483 484 void oom_during_evacuation(); 485 486 void verify_live(); 487 void verify_liveness_after_concurrent_mark(); 488 489 HeapWord* allocate_memory_work(size_t word_size); 490 HeapWord* allocate_large_memory(size_t word_size); 491 492 #ifdef ASSERT 493 void set_from_region_protection(bool protect); 494 #endif 495 496 const char* cancel_cause_to_string(ShenandoahCancelCause cause); 497 498 }; 499 500 #endif // SHARE_VM_GC_SHENANDOAH_SHENANDOAHHEAP_HPP