1 /* 2 * Copyright (c) 2002, 2012, 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_PARALLELSCAVENGE_PSPROMOTIONMANAGER_HPP 26 #define SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSPROMOTIONMANAGER_HPP 27 28 #include "gc_implementation/parallelScavenge/psPromotionLAB.hpp" 29 #include "memory/allocation.hpp" 30 #include "utilities/taskqueue.hpp" 31 32 // 33 // psPromotionManager is used by a single thread to manage object survival 34 // during a scavenge. The promotion manager contains thread local data only. 35 // 36 // NOTE! Be carefull when allocating the stacks on cheap. If you are going 37 // to use a promotion manager in more than one thread, the stacks MUST be 38 // on cheap. This can lead to memory leaks, though, as they are not auto 39 // deallocated. 40 // 41 // FIX ME FIX ME Add a destructor, and don't rely on the user to drain/flush/deallocate! 42 // 43 44 // Move to some global location 45 #define HAS_BEEN_MOVED 0x1501d01d 46 // End move to some global location 47 48 class MutableSpace; 49 class PSOldGen; 50 class ParCompactionManager; 51 52 class PSPromotionManager : public CHeapObj { 53 friend class PSScavenge; 54 friend class PSRefProcTaskExecutor; 55 private: 56 static PSPromotionManager** _manager_array; 57 static OopStarTaskQueueSet* _stack_array_depth; 58 static PSOldGen* _old_gen; 59 static MutableSpace* _young_space; 60 61 #if TASKQUEUE_STATS 62 size_t _masked_pushes; 63 size_t _masked_steals; 64 size_t _arrays_chunked; 65 size_t _array_chunks_processed; 66 67 void print_taskqueue_stats(uint i) const; 68 void print_local_stats(uint i) const; 69 static void print_stats(); 70 71 void reset_stats(); 72 #endif // TASKQUEUE_STATS 73 74 PSYoungPromotionLAB _young_lab; 75 PSOldPromotionLAB _old_lab; 76 bool _young_gen_is_full; 77 bool _old_gen_is_full; 78 79 OopStarTaskQueue _claimed_stack_depth; 80 OverflowTaskQueue<oop> _claimed_stack_breadth; 81 82 bool _totally_drain; 83 uint _target_stack_size; 84 85 uint _array_chunk_size; 86 uint _min_array_size_for_chunking; 87 88 // Accessors 89 static PSOldGen* old_gen() { return _old_gen; } 90 static MutableSpace* young_space() { return _young_space; } 91 92 inline static PSPromotionManager* manager_array(int index); 93 template <class T> inline void claim_or_forward_internal_depth(T* p); 94 95 // On the task queues we push reference locations as well as 96 // partially-scanned arrays (in the latter case, we push an oop to 97 // the from-space image of the array and the length on the 98 // from-space image indicates how many entries on the array we still 99 // need to scan; this is basically how ParNew does partial array 100 // scanning too). To be able to distinguish between reference 101 // locations and partially-scanned array oops we simply mask the 102 // latter oops with 0x01. The next three methods do the masking, 103 // unmasking, and checking whether the oop is masked or not. Notice 104 // that the signature of the mask and unmask methods looks a bit 105 // strange, as they accept and return different types (oop and 106 // oop*). This is because of the difference in types between what 107 // the task queue holds (oop*) and oops to partially-scanned arrays 108 // (oop). We do all the necessary casting in the mask / unmask 109 // methods to avoid sprinkling the rest of the code with more casts. 110 111 // These are added to the taskqueue so PS_CHUNKED_ARRAY_OOP_MASK (or any 112 // future masks) can't conflict with COMPRESSED_OOP_MASK 113 #define PS_CHUNKED_ARRAY_OOP_MASK 0x2 114 115 bool is_oop_masked(StarTask p) { 116 // If something is marked chunked it's always treated like wide oop* 117 return (((intptr_t)(oop*)p) & PS_CHUNKED_ARRAY_OOP_MASK) == 118 PS_CHUNKED_ARRAY_OOP_MASK; 119 } 120 121 oop* mask_chunked_array_oop(oop obj) { 122 assert(!is_oop_masked((oop*) obj), "invariant"); 123 oop* ret = (oop*) ((uintptr_t)obj | PS_CHUNKED_ARRAY_OOP_MASK); 124 assert(is_oop_masked(ret), "invariant"); 125 return ret; 126 } 127 128 oop unmask_chunked_array_oop(StarTask p) { 129 assert(is_oop_masked(p), "invariant"); 130 assert(!p.is_narrow(), "chunked array oops cannot be narrow"); 131 oop *chunk = (oop*)p; // cast p to oop (uses conversion operator) 132 oop ret = oop((oop*)((uintptr_t)chunk & ~PS_CHUNKED_ARRAY_OOP_MASK)); 133 assert(!is_oop_masked((oop*) ret), "invariant"); 134 return ret; 135 } 136 137 template <class T> void process_array_chunk_work(oop obj, 138 int start, int end); 139 void process_array_chunk(oop old); 140 141 template <class T> void push_depth(T* p) { 142 claimed_stack_depth()->push(p); 143 } 144 145 protected: 146 static OopStarTaskQueueSet* stack_array_depth() { return _stack_array_depth; } 147 public: 148 // Static 149 static void initialize(); 150 151 static void pre_scavenge(); 152 static void post_scavenge(); 153 154 static PSPromotionManager* gc_thread_promotion_manager(int index); 155 static PSPromotionManager* vm_thread_promotion_manager(); 156 157 static bool steal_depth(int queue_num, int* seed, StarTask& t) { 158 return stack_array_depth()->steal(queue_num, seed, t); 159 } 160 161 PSPromotionManager(); 162 163 // Accessors 164 OopStarTaskQueue* claimed_stack_depth() { 165 return &_claimed_stack_depth; 166 } 167 168 bool young_gen_is_full() { return _young_gen_is_full; } 169 170 bool old_gen_is_full() { return _old_gen_is_full; } 171 void set_old_gen_is_full(bool state) { _old_gen_is_full = state; } 172 173 // Promotion methods 174 template<bool promote_immediately> oop copy_to_survivor_space(oop o); 175 oop oop_promotion_failed(oop obj, markOop obj_mark); 176 177 void reset(); 178 179 void flush_labs(); 180 void drain_stacks(bool totally_drain) { 181 drain_stacks_depth(totally_drain); 182 } 183 public: 184 void drain_stacks_cond_depth() { 185 if (claimed_stack_depth()->size() > _target_stack_size) { 186 drain_stacks_depth(false); 187 } 188 } 189 void drain_stacks_depth(bool totally_drain); 190 191 bool stacks_empty() { 192 return claimed_stack_depth()->is_empty(); 193 } 194 195 inline void process_popped_location_depth(StarTask p); 196 197 template <class T> inline void claim_or_forward_depth(T* p); 198 199 TASKQUEUE_STATS_ONLY(inline void record_steal(StarTask& p);) 200 }; 201 202 #endif // SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSPROMOTIONMANAGER_HPP