Mercurial > jdk8-mips64-public > hotspot / file revision

 /*

  * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.

  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

  *

  * This code is free software; you can redistribute it and/or modify it

  * under the terms of the GNU General Public License version 2 only, as

  * published by the Free Software Foundation.

  *

  * This code is distributed in the hope that it will be useful, but WITHOUT

  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

  * version 2 for more details (a copy is included in the LICENSE file that

  * accompanied this code).

  *

  * You should have received a copy of the GNU General Public License version

  * 2 along with this work; if not, write to the Free Software Foundation,

  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

  *

  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

  * or visit www.oracle.com if you need additional information or have any

  * questions.

  *

  */

 //

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

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

 //

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

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

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

 // deallocated.

 //

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

 //

 // Move to some global location

 #define HAS_BEEN_MOVED 0x1501d01d

 // End move to some global location

 class MutableSpace;

 class PSOldGen;

 class ParCompactionManager;

 #define PS_PM_STATS         0

 class PSPromotionManager : public CHeapObj {

   friend class PSScavenge;

   friend class PSRefProcTaskExecutor;

  private:

   static PSPromotionManager**         _manager_array;

   static OopStarTaskQueueSet*         _stack_array_depth;

   static OopTaskQueueSet*             _stack_array_breadth;

   static PSOldGen*                    _old_gen;

   static MutableSpace*                _young_space;

 #if PS_PM_STATS

   uint                                _total_pushes;

   uint                                _masked_pushes;

   uint                                _overflow_pushes;

   uint                                _max_overflow_length;

   uint                                _arrays_chunked;

   uint                                _array_chunks_processed;

   uint                                _total_steals;

   uint                                _masked_steals;

   void print_stats(uint i);

   static void print_stats();

 #endif // PS_PM_STATS

   PSYoungPromotionLAB                 _young_lab;

   PSOldPromotionLAB                   _old_lab;

   bool                                _young_gen_is_full;

   bool                                _old_gen_is_full;

   PrefetchQueue                       _prefetch_queue;

   OopStarTaskQueue                    _claimed_stack_depth;

   OverflowTaskQueue<oop>              _claimed_stack_breadth;

   bool                                _depth_first;

   bool                                _totally_drain;

   uint                                _target_stack_size;

   uint                                _array_chunk_size;

   uint                                _min_array_size_for_chunking;

   // Accessors

   static PSOldGen* old_gen()         { return _old_gen; }

   static MutableSpace* young_space() { return _young_space; }

   inline static PSPromotionManager* manager_array(int index);

   template <class T> inline void claim_or_forward_internal_depth(T* p);

   template <class T> inline void claim_or_forward_internal_breadth(T* p);

   // On the task queues we push reference locations as well as

   // partially-scanned arrays (in the latter case, we push an oop to

   // the from-space image of the array and the length on the

   // from-space image indicates how many entries on the array we still

   // need to scan; this is basically how ParNew does partial array

   // scanning too). To be able to distinguish between reference

   // locations and partially-scanned array oops we simply mask the

   // latter oops with 0x01. The next three methods do the masking,

   // unmasking, and checking whether the oop is masked or not. Notice

   // that the signature of the mask and unmask methods looks a bit

   // strange, as they accept and return different types (oop and

   // oop*). This is because of the difference in types between what

   // the task queue holds (oop*) and oops to partially-scanned arrays

   // (oop). We do all the necessary casting in the mask / unmask

   // methods to avoid sprinkling the rest of the code with more casts.

   // These are added to the taskqueue so PS_CHUNKED_ARRAY_OOP_MASK (or any

   // future masks) can't conflict with COMPRESSED_OOP_MASK

 #define PS_CHUNKED_ARRAY_OOP_MASK  0x2

   bool is_oop_masked(StarTask p) {

     // If something is marked chunked it's always treated like wide oop*

     return (((intptr_t)(oop*)p) & PS_CHUNKED_ARRAY_OOP_MASK) ==

                                   PS_CHUNKED_ARRAY_OOP_MASK;

   }

   oop* mask_chunked_array_oop(oop obj) {

     assert(!is_oop_masked((oop*) obj), "invariant");

     oop* ret = (oop*) ((uintptr_t)obj | PS_CHUNKED_ARRAY_OOP_MASK);

     assert(is_oop_masked(ret), "invariant");

     return ret;

   }

   oop unmask_chunked_array_oop(StarTask p) {

     assert(is_oop_masked(p), "invariant");

     assert(!p.is_narrow(), "chunked array oops cannot be narrow");

     oop *chunk = (oop*)p;  // cast p to oop (uses conversion operator)

     oop ret = oop((oop*)((uintptr_t)chunk & ~PS_CHUNKED_ARRAY_OOP_MASK));

     assert(!is_oop_masked((oop*) ret), "invariant");

     return ret;

   }

   template <class T> void  process_array_chunk_work(oop obj,

                                                     int start, int end);

   void process_array_chunk(oop old);

   template <class T> void push_depth(T* p) {

     assert(depth_first(), "pre-condition");

 #if PS_PM_STATS

     ++_total_pushes;

     int stack_length = claimed_stack_depth()->overflow_stack()->length();

 #endif // PS_PM_STATS

     claimed_stack_depth()->push(p);

 #if PS_PM_STATS

     if (claimed_stack_depth()->overflow_stack()->length() != stack_length) {

       ++_overflow_pushes;

       if ((uint)stack_length + 1 > _max_overflow_length) {

         _max_overflow_length = (uint)stack_length + 1;

       }

     }

 #endif // PS_PM_STATS

   }

   void push_breadth(oop o) {

     assert(!depth_first(), "pre-condition");

 #if PS_PM_STATS

     ++_total_pushes;

     int stack_length = claimed_stack_breadth()->overflow_stack()->length();

 #endif // PS_PM_STATS

     claimed_stack_breadth()->push(o);

 #if PS_PM_STATS

     if (claimed_stack_breadth()->overflow_stack()->length() != stack_length) {

       ++_overflow_pushes;

       if ((uint)stack_length + 1 > _max_overflow_length) {

         _max_overflow_length = (uint)stack_length + 1;

       }

     }

 #endif // PS_PM_STATS

   }

  protected:

   static OopStarTaskQueueSet* stack_array_depth()   { return _stack_array_depth; }

   static OopTaskQueueSet*     stack_array_breadth() { return _stack_array_breadth; }

  public:

   // Static

   static void initialize();

   static void pre_scavenge();

   static void post_scavenge();

   static PSPromotionManager* gc_thread_promotion_manager(int index);

   static PSPromotionManager* vm_thread_promotion_manager();

   static bool steal_depth(int queue_num, int* seed, StarTask& t) {

     return stack_array_depth()->steal(queue_num, seed, t);

   }

   static bool steal_breadth(int queue_num, int* seed, oop& t) {

     return stack_array_breadth()->steal(queue_num, seed, t);

   }

   PSPromotionManager();

   // Accessors

   OopStarTaskQueue* claimed_stack_depth() {

     return &_claimed_stack_depth;

   }

   OverflowTaskQueue<oop>* claimed_stack_breadth() {

     return &_claimed_stack_breadth;

   }

   bool young_gen_is_full()             { return _young_gen_is_full; }

   bool old_gen_is_full()               { return _old_gen_is_full; }

   void set_old_gen_is_full(bool state) { _old_gen_is_full = state; }

   // Promotion methods

   oop copy_to_survivor_space(oop o, bool depth_first);

   oop oop_promotion_failed(oop obj, markOop obj_mark);

   void reset();

   void flush_labs();

   void drain_stacks(bool totally_drain) {

     if (depth_first()) {

       drain_stacks_depth(totally_drain);

     } else {

       drain_stacks_breadth(totally_drain);

     }

   }

  public:

   void drain_stacks_cond_depth() {

     if (claimed_stack_depth()->size() > _target_stack_size) {

       drain_stacks_depth(false);

     }

   }

   void drain_stacks_depth(bool totally_drain);

   void drain_stacks_breadth(bool totally_drain);

   bool depth_first() const {

     return _depth_first;

   }

   bool stacks_empty() {

     return depth_first() ?

       claimed_stack_depth()->is_empty() :

       claimed_stack_breadth()->is_empty();

   }

   inline void process_popped_location_depth(StarTask p);

   inline void flush_prefetch_queue();

   template <class T> inline void claim_or_forward_depth(T* p);

   template <class T> inline void claim_or_forward_breadth(T* p);

 #if PS_PM_STATS

   void increment_steals(oop* p = NULL) {

     _total_steals += 1;

     if (p != NULL && is_oop_masked(p)) {

       _masked_steals += 1;

     }

   }

 #endif // PS_PM_STATS

 };