1 /* 2 * Copyright (c) 2002, 2019, 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_GC_PARALLEL_PSPROMOTIONMANAGER_HPP 26 #define SHARE_GC_PARALLEL_PSPROMOTIONMANAGER_HPP 27 28 #include "gc/parallel/psPromotionLAB.hpp" 29 #include "gc/shared/copyFailedInfo.hpp" 30 #include "gc/shared/gcTrace.hpp" 31 #include "gc/shared/preservedMarks.hpp" 32 #include "gc/shared/taskqueue.hpp" 33 #include "memory/padded.hpp" 34 #include "utilities/globalDefinitions.hpp" 35 36 // 37 // psPromotionManager is used by a single thread to manage object survival 38 // during a scavenge. The promotion manager contains thread local data only. 39 // 40 // NOTE! Be careful when allocating the stacks on cheap. If you are going 41 // to use a promotion manager in more than one thread, the stacks MUST be 42 // on cheap. This can lead to memory leaks, though, as they are not auto 43 // deallocated. 44 // 45 // FIX ME FIX ME Add a destructor, and don't rely on the user to drain/flush/deallocate! 46 // 47 48 class MutableSpace; 49 class PSOldGen; 50 class ParCompactionManager; 51 52 class PSPromotionManager { 53 friend class PSScavenge; 54 friend class ScavengeRootsTask; 55 friend class PSRefProcTaskExecutor; 56 friend class PSRefProcTask; 57 58 private: 59 static PaddedEnd<PSPromotionManager>* _manager_array; 60 static OopStarTaskQueueSet* _stack_array_depth; 61 static PreservedMarksSet* _preserved_marks_set; 62 static PSOldGen* _old_gen; 63 static MutableSpace* _young_space; 64 65 #if TASKQUEUE_STATS 66 size_t _masked_pushes; 67 size_t _masked_steals; 68 size_t _arrays_chunked; 69 size_t _array_chunks_processed; 70 71 void print_local_stats(outputStream* const out, uint i) const; 72 static void print_taskqueue_stats(); 73 74 void reset_stats(); 75 #endif // TASKQUEUE_STATS 76 77 PSYoungPromotionLAB _young_lab; 78 PSOldPromotionLAB _old_lab; 79 bool _young_gen_is_full; 80 bool _old_gen_is_full; 81 82 OopStarTaskQueue _claimed_stack_depth; 83 OverflowTaskQueue<oop, mtGC> _claimed_stack_breadth; 84 85 bool _totally_drain; 86 uint _target_stack_size; 87 88 uint _array_chunk_size; 89 uint _min_array_size_for_chunking; 90 91 PreservedMarks* _preserved_marks; 92 PromotionFailedInfo _promotion_failed_info; 93 94 // Accessors 95 static PSOldGen* old_gen() { return _old_gen; } 96 static MutableSpace* young_space() { return _young_space; } 97 98 inline static PSPromotionManager* manager_array(uint index); 99 template <class T> inline void claim_or_forward_internal_depth(T* p); 100 101 // On the task queues we push reference locations as well as 102 // partially-scanned arrays (in the latter case, we push an oop to 103 // the from-space image of the array and the length on the 104 // from-space image indicates how many entries on the array we still 105 // need to scan; this is basically how ParNew did partial array 106 // scanning too). To be able to distinguish between reference 107 // locations and partially-scanned array oops we simply mask the 108 // latter oops with 0x01. The next three methods do the masking, 109 // unmasking, and checking whether the oop is masked or not. Notice 110 // that the signature of the mask and unmask methods looks a bit 111 // strange, as they accept and return different types (oop and 112 // oop*). This is because of the difference in types between what 113 // the task queue holds (oop*) and oops to partially-scanned arrays 114 // (oop). We do all the necessary casting in the mask / unmask 115 // methods to avoid sprinkling the rest of the code with more casts. 116 117 // These are added to the taskqueue so PS_CHUNKED_ARRAY_OOP_MASK (or any 118 // future masks) can't conflict with COMPRESSED_OOP_MASK 119 #define PS_CHUNKED_ARRAY_OOP_MASK 0x2 120 121 bool is_oop_masked(StarTask p) { 122 // If something is marked chunked it's always treated like wide oop* 123 return (((intptr_t)(oop*)p) & PS_CHUNKED_ARRAY_OOP_MASK) == 124 PS_CHUNKED_ARRAY_OOP_MASK; 125 } 126 127 oop* mask_chunked_array_oop(oop obj) { 128 assert(!is_oop_masked((oop*) obj), "invariant"); 129 oop* ret = (oop*) (cast_from_oop<uintptr_t>(obj) | PS_CHUNKED_ARRAY_OOP_MASK); 130 assert(is_oop_masked(ret), "invariant"); 131 return ret; 132 } 133 134 oop unmask_chunked_array_oop(StarTask p) { 135 assert(is_oop_masked(p), "invariant"); 136 assert(!p.is_narrow(), "chunked array oops cannot be narrow"); 137 oop *chunk = (oop*)p; // cast p to oop (uses conversion operator) 138 oop ret = oop((oop*)((uintptr_t)chunk & ~PS_CHUNKED_ARRAY_OOP_MASK)); 139 assert(!is_oop_masked((oop*) ret), "invariant"); 140 return ret; 141 } 142 143 template <class T> void process_array_chunk_work(oop obj, 144 int start, int end); 145 void process_array_chunk(oop old); 146 147 template <class T> void push_depth(T* p); 148 149 inline void promotion_trace_event(oop new_obj, oop old_obj, size_t obj_size, 150 uint age, bool tenured, 151 const PSPromotionLAB* lab); 152 153 protected: 154 static OopStarTaskQueueSet* stack_array_depth() { return _stack_array_depth; } 155 public: 156 // Static 157 static void initialize(); 158 159 static void pre_scavenge(); 160 static bool post_scavenge(YoungGCTracer& gc_tracer); 161 162 static PSPromotionManager* gc_thread_promotion_manager(uint index); 163 static PSPromotionManager* vm_thread_promotion_manager(); 164 165 static bool steal_depth(int queue_num, StarTask& t); 166 167 PSPromotionManager(); 168 169 // Accessors 170 OopStarTaskQueue* claimed_stack_depth() { 171 return &_claimed_stack_depth; 172 } 173 174 bool young_gen_is_full() { return _young_gen_is_full; } 175 176 bool old_gen_is_full() { return _old_gen_is_full; } 177 void set_old_gen_is_full(bool state) { _old_gen_is_full = state; } 178 179 // Promotion methods 180 template<bool promote_immediately> oop copy_to_survivor_space(oop o); 181 oop oop_promotion_failed(oop obj, markWord obj_mark); 182 183 void reset(); 184 void register_preserved_marks(PreservedMarks* preserved_marks); 185 static void restore_preserved_marks(); 186 187 void flush_labs(); 188 void drain_stacks(bool totally_drain) { 189 drain_stacks_depth(totally_drain); 190 } 191 public: 192 void drain_stacks_cond_depth() { 193 if (claimed_stack_depth()->size() > _target_stack_size) { 194 drain_stacks_depth(false); 195 } 196 } 197 void drain_stacks_depth(bool totally_drain); 198 199 bool stacks_empty() { 200 return claimed_stack_depth()->is_empty(); 201 } 202 203 inline void process_popped_location_depth(StarTask p); 204 205 static bool should_scavenge(oop* p, bool check_to_space = false); 206 static bool should_scavenge(narrowOop* p, bool check_to_space = false); 207 208 template <class T, bool promote_immediately> 209 void copy_and_push_safe_barrier(T* p); 210 211 template <class T> inline void claim_or_forward_depth(T* p); 212 213 TASKQUEUE_STATS_ONLY(inline void record_steal(StarTask& p);) 214 215 void push_contents(oop obj); 216 }; 217 218 #endif // SHARE_GC_PARALLEL_PSPROMOTIONMANAGER_HPP