1 /*

     2  * Copyright 2005-2007 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

    20  * CA 95054 USA or visit www.sun.com if you need additional information or

    21  * have any questions.

    22  *

    23  */

    24 

    25 //

    26 // psPromotionManager is used by a single thread to manage object survival

    27 // during a scavenge. The promotion manager contains thread local data only.

    28 //

    29 // NOTE! Be carefull when allocating the stacks on cheap. If you are going

    30 // to use a promotion manager in more than one thread, the stacks MUST be

    31 // on cheap. This can lead to memory leaks, though, as they are not auto

    32 // deallocated.

    33 //

    34 // FIX ME FIX ME Add a destructor, and don't rely on the user to drain/flush/deallocate!

    35 //

    36 

    37 // Move to some global location

    38 #define HAS_BEEN_MOVED 0x1501d01d

    39 // End move to some global location

    40 

    41 

    42 class MutableSpace;

    43 class PSOldGen;

    44 class ParCompactionManager;

    45 class ObjectStartArray;

    46 class ParallelCompactData;

    47 class ParMarkBitMap;

    48 

    49 // Move to it's own file if this works out.

    50 

    51 class ParCompactionManager : public CHeapObj {

    52   friend class ParallelTaskTerminator;

    53   friend class ParMarkBitMap;

    54   friend class PSParallelCompact;

    55   friend class StealChunkCompactionTask;

    56   friend class UpdateAndFillClosure;

    57   friend class RefProcTaskExecutor;

    58 

    59  public:

    60 

    61 // ------------------------  Don't putback if not needed

    62   // Actions that the compaction manager should take.

    63   enum Action {

    64     Update,

    65     Copy,

    66     UpdateAndCopy,

    67     CopyAndUpdate,

    68     VerifyUpdate,

    69     ResetObjects,

    70     NotValid

    71   };

    72 // ------------------------  End don't putback if not needed

    73 

    74  private:

    75   static ParCompactionManager**  _manager_array;

    76   static OopTaskQueueSet*      _stack_array;

    77   static ObjectStartArray*     _start_array;

    78   static ChunkTaskQueueSet*    _chunk_array;

    79   static PSOldGen*             _old_gen;

    80 

    81   OopTaskQueue                 _marking_stack;

    82   GrowableArray<oop>*          _overflow_stack;

    83   // Is there a way to reuse the _marking_stack for the

    84   // saving empty chunks?  For now just create a different

    85   // type of TaskQueue.

    86 

    87 #ifdef USE_ChunkTaskQueueWithOverflow

    88   ChunkTaskQueueWithOverflow   _chunk_stack;

    89 #else

    90   ChunkTaskQueue               _chunk_stack;

    91   GrowableArray<size_t>*       _chunk_overflow_stack;

    92 #endif

    93 

    94 #if 1  // does this happen enough to need a per thread stack?

    95   GrowableArray<Klass*>*       _revisit_klass_stack;

    96 #endif

    97   static ParMarkBitMap* _mark_bitmap;

    98 

    99   Action _action;

   100 

   101   static PSOldGen* old_gen()             { return _old_gen; }

   102   static ObjectStartArray* start_array() { return _start_array; }

   103   static OopTaskQueueSet* stack_array()   { return _stack_array; }

   104 

   105   static void initialize(ParMarkBitMap* mbm);

   106 

   107  protected:

   108   // Array of tasks.  Needed by the ParallelTaskTerminator.

   109   static ChunkTaskQueueSet* chunk_array()   { return _chunk_array; }

   110 

   111   OopTaskQueue*  marking_stack()          { return &_marking_stack; }

   112   GrowableArray<oop>* overflow_stack()    { return _overflow_stack; }

   113 #ifdef USE_ChunkTaskQueueWithOverflow

   114   ChunkTaskQueueWithOverflow* chunk_stack() { return &_chunk_stack; }

   115 #else

   116   ChunkTaskQueue*  chunk_stack()          { return &_chunk_stack; }

   117   GrowableArray<size_t>* chunk_overflow_stack() { return _chunk_overflow_stack; }

   118 #endif

   119 

   120   // Pushes onto the marking stack.  If the marking stack is full,

   121   // pushes onto the overflow stack.

   122   void stack_push(oop obj);

   123   // Do not implement an equivalent stack_pop.  Deal with the

   124   // marking stack and overflow stack directly.

   125 

   126   // Pushes onto the chunk stack.  If the chunk stack is full,

   127   // pushes onto the chunk overflow stack.

   128   void chunk_stack_push(size_t chunk_index);

   129  public:

   130 

   131   Action action() { return _action; }

   132   void set_action(Action v) { _action = v; }

   133 

   134   inline static ParCompactionManager* manager_array(int index);

   135 

   136   ParCompactionManager();

   137   ~ParCompactionManager();

   138 

   139   void allocate_stacks();

   140   void deallocate_stacks();

   141   ParMarkBitMap* mark_bitmap() { return _mark_bitmap; }

   142 

   143   // Take actions in preparation for a compaction.

   144   static void reset();

   145 

   146   // void drain_stacks();

   147 

   148   bool should_update();

   149   bool should_copy();

   150   bool should_verify_only();

   151   bool should_reset_only();

   152 

   153 #if 1

   154   // Probably stays as a growable array

   155   GrowableArray<Klass*>* revisit_klass_stack() { return _revisit_klass_stack; }

   156 #endif

   157 

   158   // Save oop for later processing.  Must not fail.

   159   void save_for_scanning(oop m);

   160   // Get a oop for scanning.  If returns null, no oop were found.

   161   oop retrieve_for_scanning();

   162 

   163   // Save chunk for later processing.  Must not fail.

   164   void save_for_processing(size_t chunk_index);

   165   // Get a chunk for processing.  If returns null, no chunk were found.

   166   bool retrieve_for_processing(size_t& chunk_index);

   167 

   168   // Access function for compaction managers

   169   static ParCompactionManager* gc_thread_compaction_manager(int index);

   170 

   171   static bool steal(int queue_num, int* seed, Task& t) {

   172     return stack_array()->steal(queue_num, seed, t);

   173   }

   174 

   175   static bool steal(int queue_num, int* seed, ChunkTask& t) {

   176     return chunk_array()->steal(queue_num, seed, t);

   177   }

   178 

   179   // Process tasks remaining on any stack

   180   void drain_marking_stacks(OopClosure *blk);

   181 

   182   // Process tasks remaining on any stack

   183   void drain_chunk_stacks();

   184 

   185   // Process tasks remaining on any stack

   186   void drain_chunk_overflow_stack();

   187 

   188   // Debugging support

   189 #ifdef ASSERT

   190   bool stacks_have_been_allocated();

   191 #endif

   192 };

   193 

   194 inline ParCompactionManager* ParCompactionManager::manager_array(int index) {

   195   assert(_manager_array != NULL, "access of NULL manager_array");

   196   assert(index >= 0 && index <= (int)ParallelGCThreads,

   197     "out of range manager_array access");

   198   return _manager_array[index];

   199 }