1 /* 2 * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1PARSCANTHREADSTATE_HPP 26 #define SHARE_VM_GC_IMPLEMENTATION_G1_G1PARSCANTHREADSTATE_HPP 27 28 #include "gc_implementation/g1/dirtyCardQueue.hpp" 29 #include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp" 30 #include "gc_implementation/g1/g1CollectedHeap.hpp" 31 #include "gc_implementation/g1/g1CollectorPolicy.hpp" 32 #include "gc_implementation/g1/g1OopClosures.hpp" 33 #include "gc_implementation/g1/g1RemSet.hpp" 34 #include "gc_implementation/shared/ageTable.hpp" 35 #include "memory/allocation.hpp" 36 #include "oops/oop.hpp" 37 38 class HeapRegion; 39 class outputStream; 40 41 class G1ParScanThreadState : public StackObj { 42 protected: 43 G1CollectedHeap* _g1h; 44 RefToScanQueue* _refs; 45 DirtyCardQueue _dcq; 46 G1SATBCardTableModRefBS* _ct_bs; 47 G1RemSet* _g1_rem; 48 49 G1ParGCAllocBuffer _surviving_alloc_buffer; 50 G1ParGCAllocBuffer _tenured_alloc_buffer; 51 G1ParGCAllocBuffer* _alloc_buffers[GCAllocPurposeCount]; 52 ageTable _age_table; 53 54 G1ParScanClosure _scanner; 55 56 size_t _alloc_buffer_waste; 57 size_t _undo_waste; 58 59 OopsInHeapRegionClosure* _evac_failure_cl; 60 61 int _hash_seed; 62 uint _queue_num; 63 64 size_t _term_attempts; 65 66 double _start; 67 double _start_strong_roots; 68 double _strong_roots_time; 69 double _start_term; 70 double _term_time; 71 72 // Map from young-age-index (0 == not young, 1 is youngest) to 73 // surviving words. base is what we get back from the malloc call 74 size_t* _surviving_young_words_base; 75 // this points into the array, as we use the first few entries for padding 76 size_t* _surviving_young_words; 77 78 #define PADDING_ELEM_NUM (DEFAULT_CACHE_LINE_SIZE / sizeof(size_t)) 79 80 void add_to_alloc_buffer_waste(size_t waste) { _alloc_buffer_waste += waste; } 81 82 void add_to_undo_waste(size_t waste) { _undo_waste += waste; } 83 84 DirtyCardQueue& dirty_card_queue() { return _dcq; } 85 G1SATBCardTableModRefBS* ctbs() { return _ct_bs; } 86 87 template <class T> inline void immediate_rs_update(HeapRegion* from, T* p, int tid); 88 89 template <class T> void deferred_rs_update(HeapRegion* from, T* p, int tid) { 90 // If the new value of the field points to the same region or 91 // is the to-space, we don't need to include it in the Rset updates. 92 if (!from->is_in_reserved(oopDesc::load_decode_heap_oop(p)) && !from->is_survivor()) { 93 size_t card_index = ctbs()->index_for(p); 94 // If the card hasn't been added to the buffer, do it. 95 if (ctbs()->mark_card_deferred(card_index)) { 96 dirty_card_queue().enqueue((jbyte*)ctbs()->byte_for_index(card_index)); 97 } 98 } 99 } 100 101 public: 102 G1ParScanThreadState(G1CollectedHeap* g1h, uint queue_num, ReferenceProcessor* rp); 103 ~G1ParScanThreadState() { 104 retire_alloc_buffers(); 105 FREE_C_HEAP_ARRAY(size_t, _surviving_young_words_base, mtGC); 106 } 107 108 RefToScanQueue* refs() { return _refs; } 109 ageTable* age_table() { return &_age_table; } 110 111 G1ParGCAllocBuffer* alloc_buffer(GCAllocPurpose purpose) { 112 return _alloc_buffers[purpose]; 113 } 114 115 size_t alloc_buffer_waste() const { return _alloc_buffer_waste; } 116 size_t undo_waste() const { return _undo_waste; } 117 118 #ifdef ASSERT 119 bool verify_ref(narrowOop* ref) const; 120 bool verify_ref(oop* ref) const; 121 bool verify_task(StarTask ref) const; 122 #endif // ASSERT 123 124 template <class T> void push_on_queue(T* ref) { 125 assert(verify_ref(ref), "sanity"); 126 refs()->push(ref); 127 } 128 129 template <class T> inline void update_rs(HeapRegion* from, T* p, int tid); 130 131 HeapWord* allocate_slow(GCAllocPurpose purpose, size_t word_sz) { 132 HeapWord* obj = NULL; 133 size_t gclab_word_size = _g1h->desired_plab_sz(purpose); 134 if (word_sz * 100 < gclab_word_size * ParallelGCBufferWastePct) { 135 G1ParGCAllocBuffer* alloc_buf = alloc_buffer(purpose); 136 add_to_alloc_buffer_waste(alloc_buf->words_remaining()); 137 alloc_buf->retire(false /* end_of_gc */, false /* retain */); 138 139 HeapWord* buf = _g1h->par_allocate_during_gc(purpose, gclab_word_size); 140 if (buf == NULL) return NULL; // Let caller handle allocation failure. 141 // Otherwise. 142 alloc_buf->set_word_size(gclab_word_size); 143 alloc_buf->set_buf(buf); 144 145 obj = alloc_buf->allocate(word_sz); 146 assert(obj != NULL, "buffer was definitely big enough..."); 147 } else { 148 obj = _g1h->par_allocate_during_gc(purpose, word_sz); 149 } 150 return obj; 151 } 152 153 HeapWord* allocate(GCAllocPurpose purpose, size_t word_sz) { 154 HeapWord* obj = alloc_buffer(purpose)->allocate(word_sz); 155 if (obj != NULL) return obj; 156 return allocate_slow(purpose, word_sz); 157 } 158 159 void undo_allocation(GCAllocPurpose purpose, HeapWord* obj, size_t word_sz) { 160 if (alloc_buffer(purpose)->contains(obj)) { 161 assert(alloc_buffer(purpose)->contains(obj + word_sz - 1), 162 "should contain whole object"); 163 alloc_buffer(purpose)->undo_allocation(obj, word_sz); 164 } else { 165 CollectedHeap::fill_with_object(obj, word_sz); 166 add_to_undo_waste(word_sz); 167 } 168 } 169 170 void set_evac_failure_closure(OopsInHeapRegionClosure* evac_failure_cl) { 171 _evac_failure_cl = evac_failure_cl; 172 } 173 OopsInHeapRegionClosure* evac_failure_closure() { 174 return _evac_failure_cl; 175 } 176 177 int* hash_seed() { return &_hash_seed; } 178 uint queue_num() { return _queue_num; } 179 180 size_t term_attempts() const { return _term_attempts; } 181 void note_term_attempt() { _term_attempts++; } 182 183 void start_strong_roots() { 184 _start_strong_roots = os::elapsedTime(); 185 } 186 void end_strong_roots() { 187 _strong_roots_time += (os::elapsedTime() - _start_strong_roots); 188 } 189 double strong_roots_time() const { return _strong_roots_time; } 190 191 void start_term_time() { 192 note_term_attempt(); 193 _start_term = os::elapsedTime(); 194 } 195 void end_term_time() { 196 _term_time += (os::elapsedTime() - _start_term); 197 } 198 double term_time() const { return _term_time; } 199 200 double elapsed_time() const { 201 return os::elapsedTime() - _start; 202 } 203 204 static void 205 print_termination_stats_hdr(outputStream* const st = gclog_or_tty); 206 void 207 print_termination_stats(int i, outputStream* const st = gclog_or_tty) const; 208 209 size_t* surviving_young_words() { 210 // We add on to hide entry 0 which accumulates surviving words for 211 // age -1 regions (i.e. non-young ones) 212 return _surviving_young_words; 213 } 214 215 private: 216 void retire_alloc_buffers() { 217 for (int ap = 0; ap < GCAllocPurposeCount; ++ap) { 218 size_t waste = _alloc_buffers[ap]->words_remaining(); 219 add_to_alloc_buffer_waste(waste); 220 _alloc_buffers[ap]->flush_stats_and_retire(_g1h->stats_for_purpose((GCAllocPurpose)ap), 221 true /* end_of_gc */, 222 false /* retain */); 223 } 224 } 225 226 #define G1_PARTIAL_ARRAY_MASK 0x2 227 228 inline bool has_partial_array_mask(oop* ref) const { 229 return ((uintptr_t)ref & G1_PARTIAL_ARRAY_MASK) == G1_PARTIAL_ARRAY_MASK; 230 } 231 232 // We never encode partial array oops as narrowOop*, so return false immediately. 233 // This allows the compiler to create optimized code when popping references from 234 // the work queue. 235 inline bool has_partial_array_mask(narrowOop* ref) const { 236 assert(((uintptr_t)ref & G1_PARTIAL_ARRAY_MASK) != G1_PARTIAL_ARRAY_MASK, "Partial array oop reference encoded as narrowOop*"); 237 return false; 238 } 239 240 // Only implement set_partial_array_mask() for regular oops, not for narrowOops. 241 // We always encode partial arrays as regular oop, to allow the 242 // specialization for has_partial_array_mask() for narrowOops above. 243 // This means that unintentional use of this method with narrowOops are caught 244 // by the compiler. 245 inline oop* set_partial_array_mask(oop obj) const { 246 assert(((uintptr_t)(void *)obj & G1_PARTIAL_ARRAY_MASK) == 0, "Information loss!"); 247 return (oop*) ((uintptr_t)(void *)obj | G1_PARTIAL_ARRAY_MASK); 248 } 249 250 inline oop clear_partial_array_mask(oop* ref) const { 251 return cast_to_oop((intptr_t)ref & ~G1_PARTIAL_ARRAY_MASK); 252 } 253 254 inline void do_oop_partial_array(oop* p); 255 256 // This method is applied to the fields of the objects that have just been copied. 257 template <class T> void do_oop_evac(T* p, HeapRegion* from) { 258 assert(!oopDesc::is_null(oopDesc::load_decode_heap_oop(p)), 259 "Reference should not be NULL here as such are never pushed to the task queue."); 260 oop obj = oopDesc::load_decode_heap_oop_not_null(p); 261 262 // Although we never intentionally push references outside of the collection 263 // set, due to (benign) races in the claim mechanism during RSet scanning more 264 // than one thread might claim the same card. So the same card may be 265 // processed multiple times. So redo this check. 266 if (_g1h->in_cset_fast_test(obj)) { 267 oop forwardee; 268 if (obj->is_forwarded()) { 269 forwardee = obj->forwardee(); 270 } else { 271 forwardee = copy_to_survivor_space(obj); 272 } 273 assert(forwardee != NULL, "forwardee should not be NULL"); 274 oopDesc::encode_store_heap_oop(p, forwardee); 275 } 276 277 assert(obj != NULL, "Must be"); 278 update_rs(from, p, queue_num()); 279 } 280 public: 281 282 oop copy_to_survivor_space(oop const obj); 283 284 template <class T> inline void deal_with_reference(T* ref_to_scan); 285 286 inline void deal_with_reference(StarTask ref); 287 288 public: 289 void trim_queue(); 290 }; 291 292 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1PARSCANTHREADSTATE_HPP