1 /*
   2  * Copyright (c) 2001, 2015, 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.
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  24 
  25 #ifndef SHARE_VM_GC_SERIAL_TENUREDGENERATION_HPP
  26 #define SHARE_VM_GC_SERIAL_TENUREDGENERATION_HPP
  27 
  28 #include "gc/serial/cSpaceCounters.hpp"
  29 #include "gc/shared/cardGeneration.hpp"
  30 #include "gc/shared/gcStats.hpp"
  31 #include "gc/shared/generationCounters.hpp"
  32 #include "utilities/macros.hpp"
  33 
  34 // TenuredGeneration models the heap containing old (promoted/tenured) objects
  35 // contained in a single contiguous space.
  36 //
  37 // Garbage collection is performed using mark-compact.
  38 
  39 class TenuredGeneration: public CardGeneration {
  40   friend class VMStructs;
  41   // Abstractly, this is a subtype that gets access to protected fields.
  42   friend class VM_PopulateDumpSharedSpace;
  43 
  44  protected:
  45   ContiguousSpace*  _the_space;       // Actual space holding objects
  46 
  47   GenerationCounters*   _gen_counters;
  48   CSpaceCounters*       _space_counters;
  49 
  50   // Allocation failure
  51   virtual bool expand(size_t bytes, size_t expand_bytes);
  52 
  53   // Accessing spaces
  54   ContiguousSpace* space() const { return _the_space; }
  55 
  56   void assert_correct_size_change_locking();
  57  public:
  58   TenuredGeneration(ReservedSpace rs, size_t initial_byte_size,
  59                                int level, GenRemSet* remset);
  60 
  61   Generation::Name kind() { return Generation::MarkSweepCompact; }
  62 
  63   // Printing
  64   const char* name() const { return "tenured generation"; }
  65   const char* short_name() const { return "Tenured"; }
  66 
  67   // Does a "full" (forced) collection invoked on this generation collect
  68   // all younger generations as well? Note that this is a
  69   // hack to allow the collection of the younger gen first if the flag is
  70   // set.
  71   virtual bool full_collects_younger_generations() const {
  72     return !ScavengeBeforeFullGC;
  73   }
  74 
  75   size_t unsafe_max_alloc_nogc() const;
  76   size_t contiguous_available() const;
  77 
  78   // Iteration
  79   void object_iterate(ObjectClosure* blk);
  80 
  81   virtual inline HeapWord* allocate(size_t word_size, bool is_tlab);
  82   virtual inline HeapWord* par_allocate(size_t word_size, bool is_tlab);
  83 
  84 #define TenuredGen_SINCE_SAVE_MARKS_DECL(OopClosureType, nv_suffix)     \
  85   void oop_since_save_marks_iterate##nv_suffix(OopClosureType* cl);
  86   TenuredGen_SINCE_SAVE_MARKS_DECL(OopsInGenClosure,_v)
  87   SPECIALIZED_SINCE_SAVE_MARKS_CLOSURES(TenuredGen_SINCE_SAVE_MARKS_DECL)
  88 
  89   void save_marks();
  90   void reset_saved_marks();
  91   bool no_allocs_since_save_marks();
  92 
  93   inline size_t block_size(const HeapWord* addr) const;
  94 
  95   inline bool block_is_obj(const HeapWord* addr) const;
  96 
  97   virtual void collect(bool full,
  98                        bool clear_all_soft_refs,
  99                        size_t size,
 100                        bool is_tlab);
 101   HeapWord* expand_and_allocate(size_t size,
 102                                 bool is_tlab,
 103                                 bool parallel = false);
 104 
 105   virtual void prepare_for_verify();
 106 
 107 
 108   virtual void gc_prologue(bool full);
 109   virtual void gc_epilogue(bool full);
 110   bool should_collect(bool   full,
 111                       size_t word_size,
 112                       bool   is_tlab);
 113 
 114   virtual void compute_new_size();
 115 
 116   // Performance Counter support
 117   void update_counters();
 118 
 119   virtual void record_spaces_top();
 120 
 121   // Statistics
 122 
 123   virtual void update_gc_stats(int level, bool full);
 124 
 125   virtual bool promotion_attempt_is_safe(size_t max_promoted_in_bytes) const;
 126 
 127   virtual void verify();
 128   virtual void print_on(outputStream* st) const;
 129 };
 130 
 131 #endif // SHARE_VM_GC_SERIAL_TENUREDGENERATION_HPP