rev 13243 : 8179268: Factor out AdaptiveSizePolicy from top-level interfaces CollectorPolicy and CollectedHeap
Reviewed-by: pliden, mgerdin

   1 /*
   2  * Copyright (c) 2001, 2016, 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.
  22  *
  23  */
  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   // Set to true when policy wants soft refs cleared.
  76   // Reset to false by gc after it clears all soft refs.
  77   bool _should_clear_all_soft_refs;
  78 
  79   // Set to true by the GC if the just-completed gc cleared all
  80   // softrefs.  This is set to true whenever a gc clears all softrefs, and
  81   // set to false each time gc returns to the mutator.  For example, in the
  82   // ParallelScavengeHeap case the latter would be done toward the end of
  83   // mem_allocate() where it returns op.result()
  84   bool _all_soft_refs_clear;
  85 
  86   CollectorPolicy();
  87 
  88  public:
  89   virtual void initialize_all() {
  90     initialize_alignments();
  91     initialize_flags();
  92     initialize_size_info();
  93   }
  94 
  95   // Return maximum heap alignment that may be imposed by the policy.
  96   static size_t compute_heap_alignment();
  97 
  98   size_t space_alignment()        { return _space_alignment; }
  99   size_t heap_alignment()         { return _heap_alignment; }
 100 
 101   size_t initial_heap_byte_size() { return _initial_heap_byte_size; }
 102   size_t max_heap_byte_size()     { return _max_heap_byte_size; }
 103   size_t min_heap_byte_size()     { return _min_heap_byte_size; }
 104 

 105   bool should_clear_all_soft_refs() { return _should_clear_all_soft_refs; }
 106   void set_should_clear_all_soft_refs(bool v) { _should_clear_all_soft_refs = v; }
 107   // Returns the current value of _should_clear_all_soft_refs.
 108   // _should_clear_all_soft_refs is set to false as a side effect.
 109   bool use_should_clear_all_soft_refs(bool v);
 110   bool all_soft_refs_clear() { return _all_soft_refs_clear; }
 111   void set_all_soft_refs_clear(bool v) { _all_soft_refs_clear = v; }
 112 
 113   // Called by the GC after Soft Refs have been cleared to indicate
 114   // that the request in _should_clear_all_soft_refs has been fulfilled.
 115   virtual void cleared_all_soft_refs();
 116 
 117   // Identification methods.
 118   virtual GenCollectorPolicy*           as_generation_policy()            { return NULL; }
 119   virtual MarkSweepPolicy*              as_mark_sweep_policy()            { return NULL; }
 120 #if INCLUDE_ALL_GCS
 121   virtual ConcurrentMarkSweepPolicy*    as_concurrent_mark_sweep_policy() { return NULL; }
 122 #endif // INCLUDE_ALL_GCS
 123   // Note that these are not virtual.
 124   bool is_generation_policy()            { return as_generation_policy() != NULL; }
 125   bool is_mark_sweep_policy()            { return as_mark_sweep_policy() != NULL; }
 126 #if INCLUDE_ALL_GCS
 127   bool is_concurrent_mark_sweep_policy() { return as_concurrent_mark_sweep_policy() != NULL; }
 128 #else  // INCLUDE_ALL_GCS
 129   bool is_concurrent_mark_sweep_policy() { return false; }
 130 #endif // INCLUDE_ALL_GCS
 131 
 132 
 133   virtual CardTableRS* create_rem_set(MemRegion reserved);
 134 
 135   MetaWord* satisfy_failed_metadata_allocation(ClassLoaderData* loader_data,
 136                                                size_t size,
 137                                                Metaspace::MetadataType mdtype);
 138 };
 139 
 140 class ClearedAllSoftRefs : public StackObj {
 141   bool _clear_all_soft_refs;
 142   CollectorPolicy* _collector_policy;
 143  public:
 144   ClearedAllSoftRefs(bool clear_all_soft_refs,
 145                      CollectorPolicy* collector_policy) :
 146     _clear_all_soft_refs(clear_all_soft_refs),
 147     _collector_policy(collector_policy) {}
 148 
 149   ~ClearedAllSoftRefs() {
 150     if (_clear_all_soft_refs) {
 151       _collector_policy->cleared_all_soft_refs();
 152     }
 153   }
 154 };
 155 
 156 class GenCollectorPolicy : public CollectorPolicy {
 157   friend class TestGenCollectorPolicy;
 158   friend class VMStructs;
 159 
 160 protected:
 161   size_t _min_young_size;
 162   size_t _initial_young_size;
 163   size_t _max_young_size;
 164   size_t _min_old_size;
 165   size_t _initial_old_size;
 166   size_t _max_old_size;
 167 
 168   // _gen_alignment and _space_alignment will have the same value most of the
 169   // time. When using large pages they can differ.
 170   size_t _gen_alignment;
 171 
 172   GenerationSpec* _young_gen_spec;
 173   GenerationSpec* _old_gen_spec;
 174 
 175   GCPolicyCounters* _gc_policy_counters;
 176 
 177   // The sizing of the heap is controlled by a sizing policy.
 178   AdaptiveSizePolicy* _size_policy;
 179 
 180   // Return true if an allocation should be attempted in the older generation
 181   // if it fails in the younger generation.  Return false, otherwise.
 182   virtual bool should_try_older_generation_allocation(size_t word_size) const;
 183 
 184   void initialize_flags();
 185   void initialize_size_info();
 186 
 187   DEBUG_ONLY(void assert_flags();)
 188   DEBUG_ONLY(void assert_size_info();)
 189 
 190   // Try to allocate space by expanding the heap.
 191   virtual HeapWord* expand_heap_and_allocate(size_t size, bool is_tlab);
 192 
 193   // Compute max heap alignment.
 194   size_t compute_max_alignment();
 195 
 196   // Scale the base_size by NewRatio according to
 197   //     result = base_size / (NewRatio + 1)
 198   // and align by min_alignment()
 199   size_t scale_by_NewRatio_aligned(size_t base_size);
 200 
 201   // Bound the value by the given maximum minus the min_alignment.
 202   size_t bound_minus_alignment(size_t desired_size, size_t maximum_size);
 203 
 204  public:
 205   GenCollectorPolicy();
 206 
 207   // Accessors
 208   size_t min_young_size()     { return _min_young_size; }
 209   size_t initial_young_size() { return _initial_young_size; }
 210   size_t max_young_size()     { return _max_young_size; }
 211   size_t gen_alignment()      { return _gen_alignment; }
 212   size_t min_old_size()       { return _min_old_size; }
 213   size_t initial_old_size()   { return _initial_old_size; }
 214   size_t max_old_size()       { return _max_old_size; }
 215 
 216   GenerationSpec* young_gen_spec() const {
 217     assert(_young_gen_spec != NULL, "_young_gen_spec should have been initialized");
 218     return _young_gen_spec;
 219   }
 220 
 221   GenerationSpec* old_gen_spec() const {
 222     assert(_old_gen_spec != NULL, "_old_gen_spec should have been initialized");
 223     return _old_gen_spec;
 224   }
 225 
 226   // Performance Counter support
 227   GCPolicyCounters* counters()     { return _gc_policy_counters; }
 228 
 229   // Create the jstat counters for the GC policy.
 230   virtual void initialize_gc_policy_counters() = 0;
 231 
 232   virtual GenCollectorPolicy* as_generation_policy() { return this; }
 233 
 234   virtual void initialize_generations() { };
 235 
 236   virtual void initialize_all() {
 237     CollectorPolicy::initialize_all();
 238     initialize_generations();
 239   }
 240 
 241   size_t young_gen_size_lower_bound();
 242 
 243   size_t old_gen_size_lower_bound();
 244 
 245   HeapWord* mem_allocate_work(size_t size,
 246                               bool is_tlab,
 247                               bool* gc_overhead_limit_was_exceeded);
 248 
 249   HeapWord *satisfy_failed_allocation(size_t size, bool is_tlab);
 250 
 251   // Adaptive size policy
 252   AdaptiveSizePolicy* size_policy() { return _size_policy; }
 253 
 254   virtual void initialize_size_policy(size_t init_eden_size,
 255                                       size_t init_promo_size,
 256                                       size_t init_survivor_size);
 257 
 258   virtual void cleared_all_soft_refs();
 259 
 260 };
 261 
 262 class MarkSweepPolicy : public GenCollectorPolicy {
 263  protected:
 264   void initialize_alignments();
 265   void initialize_generations();
 266 
 267  public:
 268   MarkSweepPolicy() {}
 269 
 270   MarkSweepPolicy* as_mark_sweep_policy() { return this; }
 271 
 272   void initialize_gc_policy_counters();
 273 };
 274 
 275 #endif // SHARE_VM_GC_SHARED_COLLECTORPOLICY_HPP
--- EOF ---