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

 /*

  * Copyright (c) 2001, 2008, 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

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 class PSMarkSweepDecorator;

 class PSYoungGen : public CHeapObj {

   friend class VMStructs;

   friend class ParallelScavengeHeap;

   friend class AdjoiningGenerations;

  protected:

   MemRegion       _reserved;

   PSVirtualSpace* _virtual_space;

   // Spaces

   MutableSpace* _eden_space;

   MutableSpace* _from_space;

   MutableSpace* _to_space;

   // MarkSweep Decorators

   PSMarkSweepDecorator* _eden_mark_sweep;

   PSMarkSweepDecorator* _from_mark_sweep;

   PSMarkSweepDecorator* _to_mark_sweep;

   // 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;

   // Performance counters

   PSGenerationCounters*     _gen_counters;

   SpaceCounters*            _eden_counters;

   SpaceCounters*            _from_counters;

   SpaceCounters*            _to_counters;

   // Initialize the space boundaries

   void compute_initial_space_boundaries();

   // Space boundary helper

   void set_space_boundaries(size_t eden_size, size_t survivor_size);

   virtual bool resize_generation(size_t eden_size, size_t survivor_size);

   virtual void resize_spaces(size_t eden_size, size_t survivor_size);

   // Adjust the spaces to be consistent with the virtual space.

   void post_resize();

   // Return number of bytes that the generation can change.

   // These should not be used by PSYoungGen

   virtual size_t available_for_expansion();

   virtual size_t available_for_contraction();

   // Given a desired shrinkage in the size of the young generation,

   // return the actual size available for shrinkage.

   virtual size_t limit_gen_shrink(size_t desired_change);

   // returns the number of bytes available from the current size

   // down to the minimum generation size.

   size_t available_to_min_gen();

   // Return the number of bytes available for shrinkage considering

   // the location the live data in the generation.

   virtual size_t available_to_live();

  public:

   // Initialize the generation.

   PSYoungGen(size_t        initial_byte_size,

              size_t        minimum_byte_size,

              size_t        maximum_byte_size);

   void initialize_work();

   virtual void initialize(ReservedSpace rs, size_t alignment);

   virtual void initialize_virtual_space(ReservedSpace rs, size_t alignment);

   MemRegion reserved() const            { return _reserved; }

   bool is_in(const void* p) const   {

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

   }

   bool is_in_reserved(const void* p) const   {

       return reserved().contains((void *)p);

   }

   MutableSpace*   eden_space() const    { return _eden_space; }

   MutableSpace*   from_space() const    { return _from_space; }

   MutableSpace*   to_space() const      { return _to_space; }

   PSVirtualSpace* virtual_space() const { return _virtual_space; }

   // For Adaptive size policy

   size_t min_gen_size() { return _min_gen_size; }

   // MarkSweep support

   PSMarkSweepDecorator* eden_mark_sweep() const    { return _eden_mark_sweep; }

   PSMarkSweepDecorator* from_mark_sweep() const    { return _from_mark_sweep; }

   PSMarkSweepDecorator* to_mark_sweep() const      { return _to_mark_sweep;   }

   void precompact();

   void adjust_pointers();

   void compact();

   // Parallel Old

   void move_and_update(ParCompactionManager* cm);

   // Called during/after gc

   void swap_spaces();

   // Resize generation using suggested free space size and survivor size

   // NOTE:  "eden_size" and "survivor_size" are suggestions only. Current

   //        heap layout (particularly, live objects in from space) might

   //        not allow us to use these values.

   void resize(size_t eden_size, size_t survivor_size);

   // Size info

   size_t capacity_in_bytes() const;

   size_t used_in_bytes() const;

   size_t free_in_bytes() const;

   size_t capacity_in_words() const;

   size_t used_in_words() const;

   size_t free_in_words() const;

   // The max this generation can grow to

   size_t max_size() const            { return _reserved.byte_size(); }

   // The max this generation can grow to if the boundary between

   // the generations are allowed to move.

   size_t gen_size_limit() const { return _max_gen_size; }

   bool is_maximal_no_gc() const {

     return true;  // never expands except at a GC

   }

   // Allocation

   HeapWord* allocate(size_t word_size, bool is_tlab) {

     HeapWord* result = eden_space()->cas_allocate(word_size);

     return result;

   }

   HeapWord** top_addr() const   { return eden_space()->top_addr(); }

   HeapWord** end_addr() const   { return eden_space()->end_addr(); }

   // Iteration.

   void oop_iterate(OopClosure* cl);

   void object_iterate(ObjectClosure* cl);

   virtual void reset_after_change();

   virtual void reset_survivors_after_shrink();

   // Performance Counter support

   void update_counters();

   // Debugging - do not use for time critical operations

   void print() const;

   void print_on(outputStream* st) const;

   void print_used_change(size_t prev_used) const;

   virtual const char* name() const { return "PSYoungGen"; }

   void verify(bool allow_dirty);

   // Space boundary invariant checker

   void space_invariants() PRODUCT_RETURN;

   // Helper for mangling survivor spaces.

   void mangle_survivors(MutableSpace* s1,

                         MemRegion s1MR,

                         MutableSpace* s2,

                         MemRegion s2MR) PRODUCT_RETURN;

   void record_spaces_top() PRODUCT_RETURN;

 };