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
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  24 
  25 #ifndef SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PARALLELSCAVENGEHEAP_HPP
  26 #define SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PARALLELSCAVENGEHEAP_HPP
  27 
  28 #include "gc_implementation/parallelScavenge/generationSizer.hpp"
  29 #include "gc_implementation/parallelScavenge/objectStartArray.hpp"
  30 #include "gc_implementation/parallelScavenge/psGCAdaptivePolicyCounters.hpp"
  31 #include "gc_implementation/parallelScavenge/psOldGen.hpp"
  32 #include "gc_implementation/parallelScavenge/psYoungGen.hpp"
  33 #include "gc_implementation/shared/gcPolicyCounters.hpp"
  34 #include "gc_implementation/shared/gcWhen.hpp"
  35 #include "gc_interface/collectedHeap.inline.hpp"
  36 #include "memory/collectorPolicy.hpp"
  37 #include "memory/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() : CollectedHeap(), _death_march_count(0) { }
  78 
  79   // For use by VM operations
  80   enum CollectionType {
  81     Scavenge,
  82     MarkSweep
  83   };
  84 
  85   virtual Name kind() const {
  86     return CollectedHeap::ParallelScavengeHeap;
  87   }
  88 
  89   virtual CollectorPolicy* collector_policy() const { return (CollectorPolicy*) _collector_policy; }
  90 
  91   static PSYoungGen* young_gen() { return _young_gen; }
  92   static PSOldGen* old_gen()     { return _old_gen; }
  93 
  94   virtual PSAdaptiveSizePolicy* size_policy() { return _size_policy; }
  95 
  96   static PSGCAdaptivePolicyCounters* gc_policy_counters() { return _gc_policy_counters; }
  97 
  98   static ParallelScavengeHeap* heap();
  99 
 100   static GCTaskManager* const gc_task_manager() { return _gc_task_manager; }
 101 
 102   AdjoiningGenerations* gens() { return _gens; }
 103 
 104   // Returns JNI_OK on success
 105   virtual jint initialize();
 106 
 107   void post_initialize();
 108   void update_counters();
 109 
 110   // The alignment used for the various areas
 111   size_t space_alignment()      { return _collector_policy->space_alignment(); }
 112   size_t generation_alignment() { return _collector_policy->gen_alignment(); }
 113 
 114   // Return the (conservative) maximum heap alignment
 115   static size_t conservative_max_heap_alignment() {
 116     return CollectorPolicy::compute_heap_alignment();
 117   }
 118 
 119   size_t capacity() const;
 120   size_t used() const;
 121 
 122   // Return "true" if all generations have reached the
 123   // maximal committed limit that they can reach, without a garbage
 124   // collection.
 125   virtual bool is_maximal_no_gc() const;
 126 
 127   // Return true if the reference points to an object that
 128   // can be moved in a partial collection.  For currently implemented
 129   // generational collectors that means during a collection of
 130   // the young gen.
 131   virtual bool is_scavengable(const void* addr);
 132 
 133   // Does this heap support heap inspection? (+PrintClassHistogram)
 134   bool supports_heap_inspection() const { return true; }
 135 
 136   size_t max_capacity() const;
 137 
 138   // Whether p is in the allocated part of the heap
 139   bool is_in(const void* p) const;
 140 
 141   bool is_in_reserved(const void* p) const;
 142 
 143   bool is_in_young(oop p);  // reserved part
 144   bool is_in_old(oop p);    // reserved part
 145 
 146   // Memory allocation.   "gc_time_limit_was_exceeded" will
 147   // be set to true if the adaptive size policy determine that
 148   // an excessive amount of time is being spent doing collections
 149   // and caused a NULL to be returned.  If a NULL is not returned,
 150   // "gc_time_limit_was_exceeded" has an undefined meaning.
 151   HeapWord* mem_allocate(size_t size, bool* gc_overhead_limit_was_exceeded);
 152 
 153   // Allocation attempt(s) during a safepoint. It should never be called
 154   // to allocate a new TLAB as this allocation might be satisfied out
 155   // of the old generation.
 156   HeapWord* failed_mem_allocate(size_t size);
 157 
 158   // Support for System.gc()
 159   void collect(GCCause::Cause cause);
 160 
 161   // These also should be called by the vm thread at a safepoint (e.g., from a
 162   // VM operation).
 163   //
 164   // The first collects the young generation only, unless the scavenge fails; it
 165   // will then attempt a full gc.  The second collects the entire heap; if
 166   // maximum_compaction is true, it will compact everything and clear all soft
 167   // references.
 168   inline void invoke_scavenge();
 169 
 170   // Perform a full collection
 171   virtual void do_full_collection(bool clear_all_soft_refs);
 172 
 173   bool supports_inline_contig_alloc() const { return !UseNUMA; }
 174 
 175   HeapWord** top_addr() const { return !UseNUMA ? young_gen()->top_addr() : (HeapWord**)-1; }
 176   HeapWord** end_addr() const { return !UseNUMA ? young_gen()->end_addr() : (HeapWord**)-1; }
 177 
 178   void ensure_parsability(bool retire_tlabs);
 179   void accumulate_statistics_all_tlabs();
 180   void resize_all_tlabs();
 181 
 182   bool supports_tlab_allocation() const { return true; }
 183 
 184   size_t tlab_capacity(Thread* thr) const;
 185   size_t tlab_used(Thread* thr) const;
 186   size_t unsafe_max_tlab_alloc(Thread* thr) const;
 187 
 188   // Can a compiler initialize a new object without store barriers?
 189   // This permission only extends from the creation of a new object
 190   // via a TLAB up to the first subsequent safepoint.
 191   virtual bool can_elide_tlab_store_barriers() const {
 192     return true;
 193   }
 194 
 195   virtual bool card_mark_must_follow_store() const {
 196     return false;
 197   }
 198 
 199   // Return true if we don't we need a store barrier for
 200   // initializing stores to an object at this address.
 201   virtual bool can_elide_initializing_store_barrier(oop new_obj);
 202 
 203   void object_iterate(ObjectClosure* cl);
 204   void safe_object_iterate(ObjectClosure* cl) { object_iterate(cl); }
 205 
 206   HeapWord* block_start(const void* addr) const;
 207   size_t block_size(const HeapWord* addr) const;
 208   bool block_is_obj(const HeapWord* addr) const;
 209 
 210   jlong millis_since_last_gc();
 211 
 212   void prepare_for_verify();
 213   PSHeapSummary create_ps_heap_summary();
 214   virtual void print_on(outputStream* st) const;
 215   virtual void print_on_error(outputStream* st) const;
 216   virtual void print_gc_threads_on(outputStream* st) const;
 217   virtual void gc_threads_do(ThreadClosure* tc) const;
 218   virtual void print_tracing_info() const;
 219 
 220   void verify(bool silent, VerifyOption option /* ignored */);
 221 
 222   void print_heap_change(size_t prev_used);
 223 
 224   // Resize the young generation.  The reserved space for the
 225   // generation may be expanded in preparation for the resize.
 226   void resize_young_gen(size_t eden_size, size_t survivor_size);
 227 
 228   // Resize the old generation.  The reserved space for the
 229   // generation may be expanded in preparation for the resize.
 230   void resize_old_gen(size_t desired_free_space);
 231 
 232   // Save the tops of the spaces in all generations
 233   void record_gen_tops_before_GC() PRODUCT_RETURN;
 234 
 235   // Mangle the unused parts of all spaces in the heap
 236   void gen_mangle_unused_area() PRODUCT_RETURN;
 237 
 238   // Call these in sequential code around the processing of strong roots.
 239   class ParStrongRootsScope : public MarkScope {
 240    public:
 241     ParStrongRootsScope();
 242     ~ParStrongRootsScope();
 243   };
 244 };
 245 
 246 #endif // SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PARALLELSCAVENGEHEAP_HPP