1 /*
   2  * Copyright (c) 2002, 2016, 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_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/preservedMarks.hpp"
  32 #include "gc/shared/taskqueue.hpp"
  33 #include "memory/allocation.hpp"
  34 #include "memory/padded.hpp"
  35 #include "utilities/globalDefinitions.hpp"
  36 
  37 //
  38 // psPromotionManager is used by a single thread to manage object survival
  39 // during a scavenge. The promotion manager contains thread local data only.
  40 //
  41 // NOTE! Be careful when allocating the stacks on cheap. If you are going
  42 // to use a promotion manager in more than one thread, the stacks MUST be
  43 // on cheap. This can lead to memory leaks, though, as they are not auto
  44 // deallocated.
  45 //
  46 // FIX ME FIX ME Add a destructor, and don't rely on the user to drain/flush/deallocate!
  47 //
  48 
  49 class MutableSpace;
  50 class PSOldGen;
  51 class ParCompactionManager;
  52 
  53 class PSPromotionManager VALUE_OBJ_CLASS_SPEC {
  54   friend class PSScavenge;
  55   friend class PSRefProcTaskExecutor;
  56  private:
  57   static PaddedEnd<PSPromotionManager>* _manager_array;
  58   static OopStarTaskQueueSet*           _stack_array_depth;
  59   static PreservedMarksSet*             _preserved_marks_set;
  60   static PSOldGen*                      _old_gen;
  61   static MutableSpace*                  _young_space;
  62 
  63 #if TASKQUEUE_STATS
  64   size_t                              _masked_pushes;
  65   size_t                              _masked_steals;
  66   size_t                              _arrays_chunked;
  67   size_t                              _array_chunks_processed;
  68 
  69   void print_local_stats(outputStream* const out, uint i) const;
  70   static void print_taskqueue_stats();
  71 
  72   void reset_stats();
  73 #endif // TASKQUEUE_STATS
  74 
  75   PSYoungPromotionLAB                 _young_lab;
  76   PSOldPromotionLAB                   _old_lab;
  77   bool                                _young_gen_is_full;
  78   bool                                _old_gen_is_full;
  79 
  80   OopStarTaskQueue                    _claimed_stack_depth;
  81   OverflowTaskQueue<oop, mtGC>        _claimed_stack_breadth;
  82 
  83   bool                                _totally_drain;
  84   uint                                _target_stack_size;
  85 
  86   uint                                _array_chunk_size;
  87   uint                                _min_array_size_for_chunking;
  88 
  89   PreservedMarks*                     _preserved_marks;
  90   PromotionFailedInfo                 _promotion_failed_info;
  91 
  92   // Accessors
  93   static PSOldGen* old_gen()         { return _old_gen; }
  94   static MutableSpace* young_space() { return _young_space; }
  95 
  96   inline static PSPromotionManager* manager_array(uint index);
  97   template <class T> inline void claim_or_forward_internal_depth(T* p);
  98 
  99   // On the task queues we push reference locations as well as
 100   // partially-scanned arrays (in the latter case, we push an oop to
 101   // the from-space image of the array and the length on the
 102   // from-space image indicates how many entries on the array we still
 103   // need to scan; this is basically how ParNew does partial array
 104   // scanning too). To be able to distinguish between reference
 105   // locations and partially-scanned array oops we simply mask the
 106   // latter oops with 0x01. The next three methods do the masking,
 107   // unmasking, and checking whether the oop is masked or not. Notice
 108   // that the signature of the mask and unmask methods looks a bit
 109   // strange, as they accept and return different types (oop and
 110   // oop*). This is because of the difference in types between what
 111   // the task queue holds (oop*) and oops to partially-scanned arrays
 112   // (oop). We do all the necessary casting in the mask / unmask
 113   // methods to avoid sprinkling the rest of the code with more casts.
 114 
 115   // These are added to the taskqueue so PS_CHUNKED_ARRAY_OOP_MASK (or any
 116   // future masks) can't conflict with COMPRESSED_OOP_MASK
 117 #define PS_CHUNKED_ARRAY_OOP_MASK  0x2
 118 
 119   bool is_oop_masked(StarTask p) {
 120     // If something is marked chunked it's always treated like wide oop*
 121     return (((intptr_t)(oop*)p) & PS_CHUNKED_ARRAY_OOP_MASK) ==
 122                                   PS_CHUNKED_ARRAY_OOP_MASK;
 123   }
 124 
 125   oop* mask_chunked_array_oop(oop obj) {
 126     assert(!is_oop_masked((oop*) obj), "invariant");
 127     oop* ret = (oop*) (cast_from_oop<uintptr_t>(obj) | PS_CHUNKED_ARRAY_OOP_MASK);
 128     assert(is_oop_masked(ret), "invariant");
 129     return ret;
 130   }
 131 
 132   oop unmask_chunked_array_oop(StarTask p) {
 133     assert(is_oop_masked(p), "invariant");
 134     assert(!p.is_narrow(), "chunked array oops cannot be narrow");
 135     oop *chunk = (oop*)p;  // cast p to oop (uses conversion operator)
 136     oop ret = oop((oop*)((uintptr_t)chunk & ~PS_CHUNKED_ARRAY_OOP_MASK));
 137     assert(!is_oop_masked((oop*) ret), "invariant");
 138     return ret;
 139   }
 140 
 141   template <class T> void  process_array_chunk_work(oop obj,
 142                                                     int start, int end);
 143   void process_array_chunk(oop old);
 144 
 145   template <class T> void push_depth(T* p);
 146 
 147   inline void promotion_trace_event(oop new_obj, oop old_obj, size_t obj_size,
 148                                     uint age, bool tenured,
 149                                     const PSPromotionLAB* lab);
 150 
 151  protected:
 152   static OopStarTaskQueueSet* stack_array_depth()   { return _stack_array_depth; }
 153  public:
 154   // Static
 155   static void initialize();
 156 
 157   static void pre_scavenge();
 158   static bool post_scavenge(YoungGCTracer& gc_tracer);
 159 
 160   static PSPromotionManager* gc_thread_promotion_manager(uint index);
 161   static PSPromotionManager* vm_thread_promotion_manager();
 162 
 163   static bool steal_depth(int queue_num, int* seed, StarTask& t);
 164 
 165   PSPromotionManager();
 166 
 167   // Accessors
 168   OopStarTaskQueue* claimed_stack_depth() {
 169     return &_claimed_stack_depth;
 170   }
 171 
 172   bool young_gen_is_full()             { return _young_gen_is_full; }
 173 
 174   bool old_gen_is_full()               { return _old_gen_is_full; }
 175   void set_old_gen_is_full(bool state) { _old_gen_is_full = state; }
 176 
 177   // Promotion methods
 178   template<bool promote_immediately> oop copy_to_survivor_space(oop o);
 179   oop oop_promotion_failed(oop obj, markOop obj_mark);
 180 
 181   void reset();
 182   void register_preserved_marks(PreservedMarks* preserved_marks);
 183   static void restore_preserved_marks();
 184 
 185   void flush_labs();
 186   void drain_stacks(bool totally_drain) {
 187     drain_stacks_depth(totally_drain);
 188   }
 189  public:
 190   void drain_stacks_cond_depth() {
 191     if (claimed_stack_depth()->size() > _target_stack_size) {
 192       drain_stacks_depth(false);
 193     }
 194   }
 195   void drain_stacks_depth(bool totally_drain);
 196 
 197   bool stacks_empty() {
 198     return claimed_stack_depth()->is_empty();
 199   }
 200 
 201   inline void process_popped_location_depth(StarTask p);
 202 
 203   static bool should_scavenge(oop* p, bool check_to_space = false);
 204   static bool should_scavenge(narrowOop* p, bool check_to_space = false);
 205 
 206   template <class T, bool promote_immediately>
 207   void copy_and_push_safe_barrier(T* p);
 208 
 209   template <class T> inline void claim_or_forward_depth(T* p);
 210 
 211   TASKQUEUE_STATS_ONLY(inline void record_steal(StarTask& p);)
 212 
 213   void push_contents(oop obj);
 214 };
 215 
 216 #endif // SHARE_VM_GC_PARALLEL_PSPROMOTIONMANAGER_HPP