src/share/vm/gc_implementation/parallelScavenge/psCompactionManager.hpp

Thu, 22 Sep 2011 10:57:37 -0700

author
johnc
date
Thu, 22 Sep 2011 10:57:37 -0700
changeset 3175
4dfb2df418f2
parent 2314
f95d63e2154a
child 3294
bca17e38de00
permissions
-rw-r--r--

6484982: G1: process references during evacuation pauses
Summary: G1 now uses two reference processors - one is used by concurrent marking and the other is used by STW GCs (both full and incremental evacuation pauses). In an evacuation pause, the reference processor is embedded into the closures used to scan objects. Doing so causes causes reference objects to be 'discovered' by the reference processor. At the end of the evacuation pause, these discovered reference objects are processed - preserving (and copying) referent objects (and their reachable graphs) as appropriate.
Reviewed-by: ysr, jwilhelm, brutisso, stefank, tonyp

     1 /*
     2  * Copyright (c) 2005, 2010, 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  */
    25 #ifndef SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSCOMPACTIONMANAGER_HPP
    26 #define SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSCOMPACTIONMANAGER_HPP
    28 #include "memory/allocation.hpp"
    29 #include "utilities/stack.hpp"
    30 #include "utilities/taskqueue.hpp"
    32 // Move to some global location
    33 #define HAS_BEEN_MOVED 0x1501d01d
    34 // End move to some global location
    37 class MutableSpace;
    38 class PSOldGen;
    39 class ParCompactionManager;
    40 class ObjectStartArray;
    41 class ParallelCompactData;
    42 class ParMarkBitMap;
    44 class ParCompactionManager : public CHeapObj {
    45   friend class ParallelTaskTerminator;
    46   friend class ParMarkBitMap;
    47   friend class PSParallelCompact;
    48   friend class StealRegionCompactionTask;
    49   friend class UpdateAndFillClosure;
    50   friend class RefProcTaskExecutor;
    52  public:
    54 // ------------------------  Don't putback if not needed
    55   // Actions that the compaction manager should take.
    56   enum Action {
    57     Update,
    58     Copy,
    59     UpdateAndCopy,
    60     CopyAndUpdate,
    61     VerifyUpdate,
    62     ResetObjects,
    63     NotValid
    64   };
    65 // ------------------------  End don't putback if not needed
    67  private:
    68   // 32-bit:  4K * 8 = 32KiB; 64-bit:  8K * 16 = 128KiB
    69   #define QUEUE_SIZE (1 << NOT_LP64(12) LP64_ONLY(13))
    70   typedef OverflowTaskQueue<ObjArrayTask, QUEUE_SIZE> ObjArrayTaskQueue;
    71   typedef GenericTaskQueueSet<ObjArrayTaskQueue>      ObjArrayTaskQueueSet;
    72   #undef QUEUE_SIZE
    74   static ParCompactionManager** _manager_array;
    75   static OopTaskQueueSet*       _stack_array;
    76   static ObjArrayTaskQueueSet*  _objarray_queues;
    77   static ObjectStartArray*      _start_array;
    78   static RegionTaskQueueSet*    _region_array;
    79   static PSOldGen*              _old_gen;
    81 private:
    82   OverflowTaskQueue<oop>        _marking_stack;
    83   ObjArrayTaskQueue             _objarray_stack;
    85   // Is there a way to reuse the _marking_stack for the
    86   // saving empty regions?  For now just create a different
    87   // type of TaskQueue.
    88   RegionTaskQueue               _region_stack;
    90   Stack<Klass*>                 _revisit_klass_stack;
    91   Stack<DataLayout*>            _revisit_mdo_stack;
    93   static ParMarkBitMap* _mark_bitmap;
    95   Action _action;
    97   static PSOldGen* old_gen()             { return _old_gen; }
    98   static ObjectStartArray* start_array() { return _start_array; }
    99   static OopTaskQueueSet* stack_array()  { return _stack_array; }
   101   static void initialize(ParMarkBitMap* mbm);
   103  protected:
   104   // Array of tasks.  Needed by the ParallelTaskTerminator.
   105   static RegionTaskQueueSet* region_array()      { return _region_array; }
   106   OverflowTaskQueue<oop>*  marking_stack()       { return &_marking_stack; }
   107   RegionTaskQueue* region_stack()                { return &_region_stack; }
   109   // Pushes onto the marking stack.  If the marking stack is full,
   110   // pushes onto the overflow stack.
   111   void stack_push(oop obj);
   112   // Do not implement an equivalent stack_pop.  Deal with the
   113   // marking stack and overflow stack directly.
   115  public:
   116   Action action() { return _action; }
   117   void set_action(Action v) { _action = v; }
   119   inline static ParCompactionManager* manager_array(int index);
   121   ParCompactionManager();
   123   ParMarkBitMap* mark_bitmap() { return _mark_bitmap; }
   125   // Take actions in preparation for a compaction.
   126   static void reset();
   128   // void drain_stacks();
   130   bool should_update();
   131   bool should_copy();
   132   bool should_verify_only();
   133   bool should_reset_only();
   135   Stack<Klass*>* revisit_klass_stack() { return &_revisit_klass_stack; }
   136   Stack<DataLayout*>* revisit_mdo_stack() { return &_revisit_mdo_stack; }
   138   // Save for later processing.  Must not fail.
   139   inline void push(oop obj) { _marking_stack.push(obj); }
   140   inline void push_objarray(oop objarray, size_t index);
   141   inline void push_region(size_t index);
   143   // Access function for compaction managers
   144   static ParCompactionManager* gc_thread_compaction_manager(int index);
   146   static bool steal(int queue_num, int* seed, oop& t) {
   147     return stack_array()->steal(queue_num, seed, t);
   148   }
   150   static bool steal_objarray(int queue_num, int* seed, ObjArrayTask& t) {
   151     return _objarray_queues->steal(queue_num, seed, t);
   152   }
   154   static bool steal(int queue_num, int* seed, size_t& region) {
   155     return region_array()->steal(queue_num, seed, region);
   156   }
   158   // Process tasks remaining on any marking stack
   159   void follow_marking_stacks();
   160   inline bool marking_stacks_empty() const;
   162   // Process tasks remaining on any stack
   163   void drain_region_stacks();
   165 };
   167 inline ParCompactionManager* ParCompactionManager::manager_array(int index) {
   168   assert(_manager_array != NULL, "access of NULL manager_array");
   169   assert(index >= 0 && index <= (int)ParallelGCThreads,
   170     "out of range manager_array access");
   171   return _manager_array[index];
   172 }
   174 bool ParCompactionManager::marking_stacks_empty() const {
   175   return _marking_stack.is_empty() && _objarray_stack.is_empty();
   176 }
   178 #endif // SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSCOMPACTIONMANAGER_HPP

mercurial