1 /*
   2  * Copyright (c) 2002, 2015, 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.
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   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  *
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  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
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  24 
  25 #ifndef SHARE_VM_GC_PARALLEL_PSPROMOTIONMANAGER_HPP
  26 #define SHARE_VM_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/taskqueue.hpp"
  32 #include "memory/allocation.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 VALUE_OBJ_CLASS_SPEC {
  53   friend class PSScavenge;
  54   friend class PSRefProcTaskExecutor;
  55  private:
  56   static PaddedEnd<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_local_stats(outputStream* const out, uint i) const;
  68   static void print_taskqueue_stats(outputStream* const out = gclog_or_tty);
  69 
  70   void reset_stats();
  71 #endif // TASKQUEUE_STATS
  72 
  73   PSYoungPromotionLAB                 _young_lab;
  74   PSOldPromotionLAB                   _old_lab;
  75   bool                                _young_gen_is_full;
  76   bool                                _old_gen_is_full;
  77 
  78   OopStarTaskQueue                    _claimed_stack_depth;
  79   OverflowTaskQueue<oop, mtGC>        _claimed_stack_breadth;
  80 
  81   bool                                _totally_drain;
  82   uint                                _target_stack_size;
  83 
  84   uint                                _array_chunk_size;
  85   uint                                _min_array_size_for_chunking;
  86 
  87   PromotionFailedInfo                 _promotion_failed_info;
  88 
  89   // Accessors
  90   static PSOldGen* old_gen()         { return _old_gen; }
  91   static MutableSpace* young_space() { return _young_space; }
  92 
  93   inline static PSPromotionManager* manager_array(uint index);
  94   template <class T> inline void claim_or_forward_internal_depth(T* p);
  95 
  96   // On the task queues we push reference locations as well as
  97   // partially-scanned arrays (in the latter case, we push an oop to
  98   // the from-space image of the array and the length on the
  99   // from-space image indicates how many entries on the array we still
 100   // need to scan; this is basically how ParNew does partial array
 101   // scanning too). To be able to distinguish between reference
 102   // locations and partially-scanned array oops we simply mask the
 103   // latter oops with 0x01. The next three methods do the masking,
 104   // unmasking, and checking whether the oop is masked or not. Notice
 105   // that the signature of the mask and unmask methods looks a bit
 106   // strange, as they accept and return different types (oop and
 107   // oop*). This is because of the difference in types between what
 108   // the task queue holds (oop*) and oops to partially-scanned arrays
 109   // (oop). We do all the necessary casting in the mask / unmask
 110   // methods to avoid sprinkling the rest of the code with more casts.
 111 
 112   // These are added to the taskqueue so PS_CHUNKED_ARRAY_OOP_MASK (or any
 113   // future masks) can't conflict with COMPRESSED_OOP_MASK
 114 #define PS_CHUNKED_ARRAY_OOP_MASK  0x2
 115 
 116   bool is_oop_masked(StarTask p) {
 117     // If something is marked chunked it's always treated like wide oop*
 118     return (((intptr_t)(oop*)p) & PS_CHUNKED_ARRAY_OOP_MASK) ==
 119                                   PS_CHUNKED_ARRAY_OOP_MASK;
 120   }
 121 
 122   oop* mask_chunked_array_oop(oop obj) {
 123     assert(!is_oop_masked((oop*) obj), "invariant");
 124     oop* ret = (oop*) (cast_from_oop<uintptr_t>(obj) | PS_CHUNKED_ARRAY_OOP_MASK);
 125     assert(is_oop_masked(ret), "invariant");
 126     return ret;
 127   }
 128 
 129   oop unmask_chunked_array_oop(StarTask p) {
 130     assert(is_oop_masked(p), "invariant");
 131     assert(!p.is_narrow(), "chunked array oops cannot be narrow");
 132     oop *chunk = (oop*)p;  // cast p to oop (uses conversion operator)
 133     oop ret = oop((oop*)((uintptr_t)chunk & ~PS_CHUNKED_ARRAY_OOP_MASK));
 134     assert(!is_oop_masked((oop*) ret), "invariant");
 135     return ret;
 136   }
 137 
 138   template <class T> void  process_array_chunk_work(oop obj,
 139                                                     int start, int end);
 140   void process_array_chunk(oop old);
 141 
 142   template <class T> void push_depth(T* p);
 143 
 144   inline void promotion_trace_event(oop new_obj, oop old_obj, size_t obj_size,
 145                                     uint age, bool tenured,
 146                                     const PSPromotionLAB* lab);
 147 
 148  protected:
 149   static OopStarTaskQueueSet* stack_array_depth()   { return _stack_array_depth; }
 150  public:
 151   // Static
 152   static void initialize();
 153 
 154   static void pre_scavenge();
 155   static bool post_scavenge(YoungGCTracer& gc_tracer);
 156 
 157   static PSPromotionManager* gc_thread_promotion_manager(uint index);
 158   static PSPromotionManager* vm_thread_promotion_manager();
 159 
 160   static bool steal_depth(int queue_num, int* seed, StarTask& t);
 161 
 162   PSPromotionManager();
 163 
 164   // Accessors
 165   OopStarTaskQueue* claimed_stack_depth() {
 166     return &_claimed_stack_depth;
 167   }
 168 
 169   bool young_gen_is_full()             { return _young_gen_is_full; }
 170 
 171   bool old_gen_is_full()               { return _old_gen_is_full; }
 172   void set_old_gen_is_full(bool state) { _old_gen_is_full = state; }
 173 
 174   // Promotion methods
 175   template<bool promote_immediately> oop copy_to_survivor_space(oop o);
 176   oop oop_promotion_failed(oop obj, markOop obj_mark);
 177 
 178   void reset();
 179 
 180   void flush_labs();
 181   void drain_stacks(bool totally_drain) {
 182     drain_stacks_depth(totally_drain);
 183   }
 184  public:
 185   void drain_stacks_cond_depth() {
 186     if (claimed_stack_depth()->size() > _target_stack_size) {
 187       drain_stacks_depth(false);
 188     }
 189   }
 190   void drain_stacks_depth(bool totally_drain);
 191 
 192   bool stacks_empty() {
 193     return claimed_stack_depth()->is_empty();
 194   }
 195 
 196   inline void process_popped_location_depth(StarTask p);
 197 
 198   static bool should_scavenge(oop* p, bool check_to_space = false);
 199   static bool should_scavenge(narrowOop* p, bool check_to_space = false);
 200 
 201   template <class T, bool promote_immediately>
 202   void copy_and_push_safe_barrier(T* p);
 203 
 204   template <class T> inline void claim_or_forward_depth(T* p);
 205 
 206   TASKQUEUE_STATS_ONLY(inline void record_steal(StarTask& p);)
 207 
 208   void push_contents(oop obj);
 209 };
 210 
 211 #endif // SHARE_VM_GC_PARALLEL_PSPROMOTIONMANAGER_HPP
--- EOF ---