1 /*
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   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.
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   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
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  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
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  24 
  25 #ifndef SHARE_VM_GC_SHARED_COLLECTORPOLICY_HPP
  26 #define SHARE_VM_GC_SHARED_COLLECTORPOLICY_HPP
  27 
  28 #include "gc/shared/barrierSet.hpp"
  29 #include "gc/shared/cardTableRS.hpp"
  30 #include "gc/shared/generationSpec.hpp"
  31 #include "memory/allocation.hpp"
  32 #include "utilities/macros.hpp"
  33 
  34 // This class (or more correctly, subtypes of this class)
  35 // are used to define global garbage collector attributes.
  36 // This includes initialization of generations and any other
  37 // shared resources they may need.
  38 //
  39 // In general, all flag adjustment and validation should be
  40 // done in initialize_flags(), which is called prior to
  41 // initialize_size_info().
  42 //
  43 // This class is not fully developed yet. As more collector(s)
  44 // are added, it is expected that we will come across further
  45 // behavior that requires global attention. The correct place
  46 // to deal with those issues is this class.
  47 
  48 // Forward declarations.
  49 class GenCollectorPolicy;
  50 class AdaptiveSizePolicy;
  51 #if INCLUDE_ALL_GCS
  52 class ConcurrentMarkSweepPolicy;
  53 class G1CollectorPolicy;
  54 #endif // INCLUDE_ALL_GCS
  55 
  56 class GCPolicyCounters;
  57 class MarkSweepPolicy;
  58 
  59 class CollectorPolicy : public CHeapObj<mtGC> {
  60  protected:
  61   virtual void initialize_alignments() = 0;
  62   virtual void initialize_flags();
  63   virtual void initialize_size_info();
  64 
  65   DEBUG_ONLY(virtual void assert_flags();)
  66   DEBUG_ONLY(virtual void assert_size_info();)
  67 
  68   size_t _initial_heap_byte_size;
  69   size_t _max_heap_byte_size;
  70   size_t _min_heap_byte_size;
  71 
  72   size_t _space_alignment;
  73   size_t _heap_alignment;
  74 
  75   CollectorPolicy();
  76 
  77  public:
  78   void initialize_all() {
  79     initialize_alignments();
  80     initialize_flags();
  81     initialize_size_info();
  82   }
  83 
  84   // Return maximum heap alignment that may be imposed by the policy.
  85   static size_t compute_heap_alignment();
  86 
  87   size_t space_alignment()        { return _space_alignment; }
  88   size_t heap_alignment()         { return _heap_alignment; }
  89 
  90   size_t initial_heap_byte_size() { return _initial_heap_byte_size; }
  91   size_t max_heap_byte_size()     { return _max_heap_byte_size; }
  92   size_t min_heap_byte_size()     { return _min_heap_byte_size; }
  93 };
  94 
  95 class GenCollectorPolicy : public CollectorPolicy {
  96   friend class TestGenCollectorPolicy;
  97   friend class VMStructs;
  98 
  99 protected:
 100   size_t _min_young_size;
 101   size_t _initial_young_size;
 102   size_t _max_young_size;
 103   size_t _min_old_size;
 104   size_t _initial_old_size;
 105   size_t _max_old_size;
 106 
 107   // _gen_alignment and _space_alignment will have the same value most of the
 108   // time. When using large pages they can differ.
 109   size_t _gen_alignment;
 110 
 111   GCPolicyCounters* _gc_policy_counters;
 112 
 113   void initialize_flags();
 114   void initialize_size_info();
 115 
 116   DEBUG_ONLY(void assert_flags();)
 117   DEBUG_ONLY(void assert_size_info();)
 118 
 119   // Compute max heap alignment.
 120   size_t compute_max_alignment();
 121 
 122   // Scale the base_size by NewRatio according to
 123   //     result = base_size / (NewRatio + 1)
 124   // and align by min_alignment()
 125   size_t scale_by_NewRatio_aligned(size_t base_size);
 126 
 127   // Bound the value by the given maximum minus the min_alignment.
 128   size_t bound_minus_alignment(size_t desired_size, size_t maximum_size);
 129 
 130  public:
 131   GenCollectorPolicy();
 132 
 133   // Accessors
 134   size_t min_young_size()     { return _min_young_size; }
 135   size_t initial_young_size() { return _initial_young_size; }
 136   size_t max_young_size()     { return _max_young_size; }
 137   size_t gen_alignment()      { return _gen_alignment; }
 138   size_t min_old_size()       { return _min_old_size; }
 139   size_t initial_old_size()   { return _initial_old_size; }
 140   size_t max_old_size()       { return _max_old_size; }
 141 
 142   // Performance Counter support
 143   GCPolicyCounters* counters()     { return _gc_policy_counters; }
 144 
 145   // Create the jstat counters for the GC policy.
 146   virtual void initialize_gc_policy_counters() = 0;
 147 
 148   size_t young_gen_size_lower_bound();
 149 
 150   size_t old_gen_size_lower_bound();
 151 };
 152 
 153 class MarkSweepPolicy : public GenCollectorPolicy {
 154  protected:
 155   void initialize_alignments();
 156 
 157  public:
 158   MarkSweepPolicy() {}
 159 
 160   void initialize_gc_policy_counters();
 161 };
 162 
 163 #endif // SHARE_VM_GC_SHARED_COLLECTORPOLICY_HPP