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.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_GC_PARALLEL_PARALLELSCAVENGEHEAP_HPP
  26 #define SHARE_VM_GC_PARALLEL_PARALLELSCAVENGEHEAP_HPP
  27 
  28 #include "gc/parallel/generationSizer.hpp"
  29 #include "gc/parallel/objectStartArray.hpp"
  30 #include "gc/parallel/psGCAdaptivePolicyCounters.hpp"
  31 #include "gc/parallel/psOldGen.hpp"
  32 #include "gc/parallel/psYoungGen.hpp"
  33 #include "gc/shared/collectedHeap.hpp"
  34 #include "gc/shared/collectorPolicy.hpp"
  35 #include "gc/shared/gcPolicyCounters.hpp"
  36 #include "gc/shared/gcWhen.hpp"
  37 #include "gc/shared/strongRootsScope.hpp"

  38 #include "utilities/ostream.hpp"
  39 
  40 class AdjoiningGenerations;
  41 class GCHeapSummary;
  42 class GCTaskManager;
  43 class PSAdaptiveSizePolicy;
  44 class PSHeapSummary;
  45 
  46 class ParallelScavengeHeap : public CollectedHeap {
  47   friend class VMStructs;
  48  private:
  49   static PSYoungGen* _young_gen;
  50   static PSOldGen*   _old_gen;
  51 
  52   // Sizing policy for entire heap
  53   static PSAdaptiveSizePolicy*       _size_policy;
  54   static PSGCAdaptivePolicyCounters* _gc_policy_counters;
  55 
  56   GenerationSizer* _collector_policy;
  57 
  58   // Collection of generations that are adjacent in the
  59   // space reserved for the heap.
  60   AdjoiningGenerations* _gens;
  61   unsigned int _death_march_count;
  62 
  63   // The task manager
  64   static GCTaskManager* _gc_task_manager;
  65 
  66   void trace_heap(GCWhen::Type when, const GCTracer* tracer);
  67 
  68  protected:
  69   static inline size_t total_invocations();
  70   HeapWord* allocate_new_tlab(size_t size);
  71 
  72   inline bool should_alloc_in_eden(size_t size) const;
  73   inline void death_march_check(HeapWord* const result, size_t size);
  74   HeapWord* mem_allocate_old_gen(size_t size);
  75 
  76  public:
  77   ParallelScavengeHeap(GenerationSizer* policy) :
  78     CollectedHeap(), _collector_policy(policy), _death_march_count(0) { }
  79 
  80   // For use by VM operations
  81   enum CollectionType {
  82     Scavenge,
  83     MarkSweep
  84   };
  85 
  86   virtual Name kind() const {
  87     return CollectedHeap::ParallelScavengeHeap;
  88   }
  89 




  90   virtual CollectorPolicy* collector_policy() const { return _collector_policy; }
  91 
  92   static PSYoungGen* young_gen() { return _young_gen; }
  93   static PSOldGen* old_gen()     { return _old_gen; }
  94 
  95   virtual PSAdaptiveSizePolicy* size_policy() { return _size_policy; }
  96 
  97   static PSGCAdaptivePolicyCounters* gc_policy_counters() { return _gc_policy_counters; }
  98 
  99   static ParallelScavengeHeap* heap();
 100 
 101   static GCTaskManager* const gc_task_manager() { return _gc_task_manager; }
 102 
 103   AdjoiningGenerations* gens() { return _gens; }
 104 
 105   // Returns JNI_OK on success
 106   virtual jint initialize();
 107 
 108   void post_initialize();
 109   void update_counters();
 110 
 111   // The alignment used for the various areas
 112   size_t space_alignment()      { return _collector_policy->space_alignment(); }
 113   size_t generation_alignment() { return _collector_policy->gen_alignment(); }
 114 
 115   // Return the (conservative) maximum heap alignment
 116   static size_t conservative_max_heap_alignment() {
 117     return CollectorPolicy::compute_heap_alignment();
 118   }
 119 
 120   size_t capacity() const;
 121   size_t used() const;
 122 
 123   // Return "true" if all generations have reached the
 124   // maximal committed limit that they can reach, without a garbage
 125   // collection.
 126   virtual bool is_maximal_no_gc() const;
 127 
 128   // Return true if the reference points to an object that
 129   // can be moved in a partial collection.  For currently implemented
 130   // generational collectors that means during a collection of
 131   // the young gen.
 132   virtual bool is_scavengable(const void* addr);
 133 
 134   size_t max_capacity() const;
 135 
 136   // Whether p is in the allocated part of the heap
 137   bool is_in(const void* p) const;
 138 
 139   bool is_in_reserved(const void* p) const;
 140 
 141   bool is_in_young(oop p);  // reserved part
 142   bool is_in_old(oop p);    // reserved part
 143 
 144   // Memory allocation.   "gc_time_limit_was_exceeded" will
 145   // be set to true if the adaptive size policy determine that
 146   // an excessive amount of time is being spent doing collections
 147   // and caused a NULL to be returned.  If a NULL is not returned,
 148   // "gc_time_limit_was_exceeded" has an undefined meaning.
 149   HeapWord* mem_allocate(size_t size, bool* gc_overhead_limit_was_exceeded);
 150 
 151   // Allocation attempt(s) during a safepoint. It should never be called
 152   // to allocate a new TLAB as this allocation might be satisfied out
 153   // of the old generation.
 154   HeapWord* failed_mem_allocate(size_t size);
 155 
 156   // Support for System.gc()
 157   void collect(GCCause::Cause cause);
 158 
 159   // These also should be called by the vm thread at a safepoint (e.g., from a
 160   // VM operation).
 161   //
 162   // The first collects the young generation only, unless the scavenge fails; it
 163   // will then attempt a full gc.  The second collects the entire heap; if
 164   // maximum_compaction is true, it will compact everything and clear all soft
 165   // references.
 166   inline void invoke_scavenge();
 167 
 168   // Perform a full collection
 169   virtual void do_full_collection(bool clear_all_soft_refs);
 170 
 171   bool supports_inline_contig_alloc() const { return !UseNUMA; }
 172 
 173   HeapWord** top_addr() const { return !UseNUMA ? young_gen()->top_addr() : (HeapWord**)-1; }
 174   HeapWord** end_addr() const { return !UseNUMA ? young_gen()->end_addr() : (HeapWord**)-1; }
 175 
 176   void ensure_parsability(bool retire_tlabs);
 177   void accumulate_statistics_all_tlabs();
 178   void resize_all_tlabs();
 179 
 180   bool supports_tlab_allocation() const { return true; }
 181 
 182   size_t tlab_capacity(Thread* thr) const;
 183   size_t tlab_used(Thread* thr) const;
 184   size_t unsafe_max_tlab_alloc(Thread* thr) const;
 185 
 186   // Can a compiler initialize a new object without store barriers?
 187   // This permission only extends from the creation of a new object
 188   // via a TLAB up to the first subsequent safepoint.
 189   virtual bool can_elide_tlab_store_barriers() const {
 190     return true;
 191   }
 192 
 193   virtual bool card_mark_must_follow_store() const {
 194     return false;
 195   }
 196 
 197   // Return true if we don't we need a store barrier for
 198   // initializing stores to an object at this address.
 199   virtual bool can_elide_initializing_store_barrier(oop new_obj);
 200 
 201   void object_iterate(ObjectClosure* cl);
 202   void safe_object_iterate(ObjectClosure* cl) { object_iterate(cl); }
 203 
 204   HeapWord* block_start(const void* addr) const;
 205   size_t block_size(const HeapWord* addr) const;
 206   bool block_is_obj(const HeapWord* addr) const;
 207 
 208   jlong millis_since_last_gc();
 209 
 210   void prepare_for_verify();
 211   PSHeapSummary create_ps_heap_summary();
 212   virtual void print_on(outputStream* st) const;
 213   virtual void print_on_error(outputStream* st) const;
 214   virtual void print_gc_threads_on(outputStream* st) const;
 215   virtual void gc_threads_do(ThreadClosure* tc) const;
 216   virtual void print_tracing_info() const;
 217 
 218   void verify(bool silent, VerifyOption option /* ignored */);
 219 
 220   void print_heap_change(size_t prev_used);
 221 
 222   // Resize the young generation.  The reserved space for the
 223   // generation may be expanded in preparation for the resize.
 224   void resize_young_gen(size_t eden_size, size_t survivor_size);
 225 
 226   // Resize the old generation.  The reserved space for the
 227   // generation may be expanded in preparation for the resize.
 228   void resize_old_gen(size_t desired_free_space);
 229 
 230   // Save the tops of the spaces in all generations
 231   void record_gen_tops_before_GC() PRODUCT_RETURN;
 232 
 233   // Mangle the unused parts of all spaces in the heap
 234   void gen_mangle_unused_area() PRODUCT_RETURN;
 235 
 236   // Call these in sequential code around the processing of strong roots.
 237   class ParStrongRootsScope : public MarkScope {
 238    public:
 239     ParStrongRootsScope();
 240     ~ParStrongRootsScope();
 241   };






















 242 };
 243 
 244 #endif // SHARE_VM_GC_PARALLEL_PARALLELSCAVENGEHEAP_HPP
--- EOF ---