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

 /*

  * Copyright 2001-2006 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

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

  * have any questions.

  *

  */

 class PSMarkSweepDecorator;

 class PSOldGen : public CHeapObj {

   friend class VMStructs;

   friend class PSPromotionManager; // Uses the cas_allocate methods

   friend class ParallelScavengeHeap;

   friend class AdjoiningGenerations;

  protected:

   MemRegion                _reserved;          // Used for simple containment tests

   PSVirtualSpace*          _virtual_space;     // Controls mapping and unmapping of virtual mem

   ObjectStartArray         _start_array;       // Keeps track of where objects start in a 512b block

   MutableSpace*            _object_space;      // Where all the objects live

   PSMarkSweepDecorator*    _object_mark_sweep; // The mark sweep view of _object_space

   const char* const        _name;              // Name of this generation.

   // Performance Counters

   PSGenerationCounters*    _gen_counters;

   SpaceCounters*           _space_counters;

   // Sizing information, in bytes, set in constructor

   const size_t _init_gen_size;

   const size_t _min_gen_size;

   const size_t _max_gen_size;

   // Used when initializing the _name field.

   static inline const char* select_name();

   HeapWord* allocate_noexpand(size_t word_size, bool is_tlab) {

     // We assume the heap lock is held here.

     assert(!is_tlab, "Does not support TLAB allocation");

     assert_locked_or_safepoint(Heap_lock);

     HeapWord* res = object_space()->allocate(word_size);

     if (res != NULL) {

       _start_array.allocate_block(res);

     }

     return res;

   }

   // Support for MT garbage collection. CAS allocation is lower overhead than grabbing

   // and releasing the heap lock, which is held during gc's anyway. This method is not

   // safe for use at the same time as allocate_noexpand()!

   HeapWord* cas_allocate_noexpand(size_t word_size) {

     assert(SafepointSynchronize::is_at_safepoint(), "Must only be called at safepoint")

     HeapWord* res = object_space()->cas_allocate(word_size);

     if (res != NULL) {

       _start_array.allocate_block(res);

     }

     return res;

   }

   // Support for MT garbage collection. See above comment.

   HeapWord* cas_allocate(size_t word_size) {

     HeapWord* res = cas_allocate_noexpand(word_size);

     return (res == NULL) ? expand_and_cas_allocate(word_size) : res;

   }

   HeapWord* expand_and_allocate(size_t word_size, bool is_tlab);

   HeapWord* expand_and_cas_allocate(size_t word_size);

   void expand(size_t bytes);

   bool expand_by(size_t bytes);

   bool expand_to_reserved();

   void shrink(size_t bytes);

   void post_resize();

  public:

   // Initialize the generation.

   PSOldGen(ReservedSpace rs, size_t alignment,

            size_t initial_size, size_t min_size, size_t max_size,

            const char* perf_data_name, int level);

   PSOldGen(size_t initial_size, size_t min_size, size_t max_size,

            const char* perf_data_name, int level);

   void initialize(ReservedSpace rs, size_t alignment,

                   const char* perf_data_name, int level);

   void initialize_virtual_space(ReservedSpace rs, size_t alignment);

   void initialize_work(const char* perf_data_name, int level);

   MemRegion reserved() const                { return _reserved; }

   virtual size_t max_gen_size()             { return _max_gen_size; }

   size_t min_gen_size()                     { return _min_gen_size; }

   // Returns limit on the maximum size of the generation.  This

   // is the same as _max_gen_size for PSOldGen but need not be

   // for a derived class.

   virtual size_t gen_size_limit();

   bool is_in(const void* p) const           {

     return _virtual_space->contains((void *)p);

   }

   bool is_in_reserved(const void* p) const {

     return reserved().contains(p);

   }

   MutableSpace*         object_space() const      { return _object_space; }

   PSMarkSweepDecorator* object_mark_sweep() const { return _object_mark_sweep; }

   ObjectStartArray*     start_array()             { return &_start_array; }

   PSVirtualSpace*       virtual_space() const     { return _virtual_space;}

   // Has the generation been successfully allocated?

   bool is_allocated();

   // MarkSweep methods

   virtual void precompact();

   void adjust_pointers();

   void compact();

   // Parallel old

   virtual void move_and_update(ParCompactionManager* cm);

   // Size info

   size_t capacity_in_bytes() const        { return object_space()->capacity_in_bytes(); }

   size_t used_in_bytes() const            { return object_space()->used_in_bytes(); }

   size_t free_in_bytes() const            { return object_space()->free_in_bytes(); }

   size_t capacity_in_words() const        { return object_space()->capacity_in_words(); }

   size_t used_in_words() const            { return object_space()->used_in_words(); }

   size_t free_in_words() const            { return object_space()->free_in_words(); }

   // Includes uncommitted memory

   size_t contiguous_available() const;

   bool is_maximal_no_gc() const {

     return virtual_space()->uncommitted_size() == 0;

   }

   // Calculating new sizes

   void resize(size_t desired_free_space);

   // Allocation. We report all successful allocations to the size policy

   // Note that the perm gen does not use this method, and should not!

   HeapWord* allocate(size_t word_size, bool is_tlab);

   // Iteration.

   void oop_iterate(OopClosure* cl) { object_space()->oop_iterate(cl); }

   void object_iterate(ObjectClosure* cl) { object_space()->object_iterate(cl); }

   // Debugging - do not use for time critical operations

   virtual void print() const;

   virtual void print_on(outputStream* st) const;

   void print_used_change(size_t prev_used) const;

   void verify(bool allow_dirty);

   void verify_object_start_array();

   // These should not used

   virtual void reset_after_change();

   // These should not used

   virtual size_t available_for_expansion();

   virtual size_t available_for_contraction();

   void space_invariants() PRODUCT_RETURN;

   // Performace Counter support

   void update_counters();

   // Printing support

   virtual const char* name() const { return _name; }

 };