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_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 "memory/metaspace.hpp"
  39 #include "utilities/ostream.hpp"
  40 
  41 class AdjoiningGenerations;
  42 class GCHeapSummary;
  43 class GCTaskManager;
  44 class PSAdaptiveSizePolicy;
  45 class PSHeapSummary;
  46 
  47 class ParallelScavengeHeap : public CollectedHeap {
  48   friend class VMStructs;
  49  private:
  50   static PSYoungGen* _young_gen;
  51   static PSOldGen*   _old_gen;
  52 
  53   // Sizing policy for entire heap
  54   static PSAdaptiveSizePolicy*       _size_policy;
  55   static PSGCAdaptivePolicyCounters* _gc_policy_counters;
  56 
  57   GenerationSizer* _collector_policy;
  58 
  59   // Collection of generations that are adjacent in the
  60   // space reserved for the heap.
  61   AdjoiningGenerations* _gens;
  62   unsigned int _death_march_count;
  63 
  64   // The task manager
  65   static GCTaskManager* _gc_task_manager;
  66 
  67   void trace_heap(GCWhen::Type when, const GCTracer* tracer);
  68 
  69  protected:
  70   static inline size_t total_invocations();
  71   HeapWord* allocate_new_tlab(size_t size);
  72 
  73   inline bool should_alloc_in_eden(size_t size) const;
  74   inline void death_march_check(HeapWord* const result, size_t size);
  75   HeapWord* mem_allocate_old_gen(size_t size);
  76 
  77  public:
  78   ParallelScavengeHeap(GenerationSizer* policy) :
  79     CollectedHeap(), _collector_policy(policy), _death_march_count(0) { }
  80 
  81   // For use by VM operations
  82   enum CollectionType {
  83     Scavenge,
  84     MarkSweep
  85   };
  86 
  87   virtual Name kind() const {
  88     return CollectedHeap::ParallelScavengeHeap;
  89   }
  90 
  91   virtual const char* name() const {
  92     return "Parallel";
  93   }
  94 
  95   virtual CollectorPolicy* collector_policy() const { return _collector_policy; }
  96 
  97   static PSYoungGen* young_gen() { return _young_gen; }
  98   static PSOldGen* old_gen()     { return _old_gen; }
  99 
 100   virtual PSAdaptiveSizePolicy* size_policy() { return _size_policy; }
 101 
 102   static PSGCAdaptivePolicyCounters* gc_policy_counters() { return _gc_policy_counters; }
 103 
 104   static ParallelScavengeHeap* heap();
 105 
 106   static GCTaskManager* const gc_task_manager() { return _gc_task_manager; }
 107 
 108   AdjoiningGenerations* gens() { return _gens; }
 109 
 110   // Returns JNI_OK on success
 111   virtual jint initialize();
 112 
 113   void post_initialize();
 114   void update_counters();
 115 
 116   // The alignment used for the various areas
 117   size_t space_alignment()      { return _collector_policy->space_alignment(); }
 118   size_t generation_alignment() { return _collector_policy->gen_alignment(); }
 119 
 120   // Return the (conservative) maximum heap alignment
 121   static size_t conservative_max_heap_alignment() {
 122     return CollectorPolicy::compute_heap_alignment();
 123   }
 124 
 125   size_t capacity() const;
 126   size_t used() const;
 127 
 128   // Return "true" if all generations have reached the
 129   // maximal committed limit that they can reach, without a garbage
 130   // collection.
 131   virtual bool is_maximal_no_gc() const;
 132 
 133   // Return true if the reference points to an object that
 134   // can be moved in a partial collection.  For currently implemented
 135   // generational collectors that means during a collection of
 136   // the young gen.
 137   virtual bool is_scavengable(const void* addr);
 138 
 139   size_t max_capacity() const;
 140 
 141   // Whether p is in the allocated part of the heap
 142   bool is_in(const void* p) const;
 143 
 144   bool is_in_reserved(const void* p) const;
 145 
 146   bool is_in_young(oop p);  // reserved part
 147   bool is_in_old(oop p);    // reserved part
 148 
 149   // Memory allocation.   "gc_time_limit_was_exceeded" will
 150   // be set to true if the adaptive size policy determine that
 151   // an excessive amount of time is being spent doing collections
 152   // and caused a NULL to be returned.  If a NULL is not returned,
 153   // "gc_time_limit_was_exceeded" has an undefined meaning.
 154   HeapWord* mem_allocate(size_t size, bool* gc_overhead_limit_was_exceeded);
 155 
 156   // Allocation attempt(s) during a safepoint. It should never be called
 157   // to allocate a new TLAB as this allocation might be satisfied out
 158   // of the old generation.
 159   HeapWord* failed_mem_allocate(size_t size);
 160 
 161   // Support for System.gc()
 162   void collect(GCCause::Cause cause);
 163 
 164   // These also should be called by the vm thread at a safepoint (e.g., from a
 165   // VM operation).
 166   //
 167   // The first collects the young generation only, unless the scavenge fails; it
 168   // will then attempt a full gc.  The second collects the entire heap; if
 169   // maximum_compaction is true, it will compact everything and clear all soft
 170   // references.
 171   inline void invoke_scavenge();
 172 
 173   // Perform a full collection
 174   virtual void do_full_collection(bool clear_all_soft_refs);
 175 
 176   bool supports_inline_contig_alloc() const { return !UseNUMA; }
 177 
 178   HeapWord** top_addr() const { return !UseNUMA ? young_gen()->top_addr() : (HeapWord**)-1; }
 179   HeapWord** end_addr() const { return !UseNUMA ? young_gen()->end_addr() : (HeapWord**)-1; }
 180 
 181   void ensure_parsability(bool retire_tlabs);
 182   void accumulate_statistics_all_tlabs();
 183   void resize_all_tlabs();
 184 
 185   bool supports_tlab_allocation() const { return true; }
 186 
 187   size_t tlab_capacity(Thread* thr) const;
 188   size_t tlab_used(Thread* thr) const;
 189   size_t unsafe_max_tlab_alloc(Thread* thr) const;
 190 
 191   // Can a compiler initialize a new object without store barriers?
 192   // This permission only extends from the creation of a new object
 193   // via a TLAB up to the first subsequent safepoint.
 194   virtual bool can_elide_tlab_store_barriers() const {
 195     return true;
 196   }
 197 
 198   virtual bool card_mark_must_follow_store() const {
 199     return false;
 200   }
 201 
 202   // Return true if we don't we need a store barrier for
 203   // initializing stores to an object at this address.
 204   virtual bool can_elide_initializing_store_barrier(oop new_obj);
 205 
 206   void object_iterate(ObjectClosure* cl);
 207   void safe_object_iterate(ObjectClosure* cl) { object_iterate(cl); }
 208 
 209   HeapWord* block_start(const void* addr) const;
 210   size_t block_size(const HeapWord* addr) const;
 211   bool block_is_obj(const HeapWord* addr) const;
 212 
 213   jlong millis_since_last_gc();
 214 
 215   void prepare_for_verify();
 216   PSHeapSummary create_ps_heap_summary();
 217   virtual void print_on(outputStream* st) const;
 218   virtual void print_on_error(outputStream* st) const;
 219   virtual void print_gc_threads_on(outputStream* st) const;
 220   virtual void gc_threads_do(ThreadClosure* tc) const;
 221   virtual void print_tracing_info() const;
 222 
 223   void verify(VerifyOption option /* ignored */);


 224 
 225   // Resize the young generation.  The reserved space for the
 226   // generation may be expanded in preparation for the resize.
 227   void resize_young_gen(size_t eden_size, size_t survivor_size);
 228 
 229   // Resize the old generation.  The reserved space for the
 230   // generation may be expanded in preparation for the resize.
 231   void resize_old_gen(size_t desired_free_space);
 232 
 233   // Save the tops of the spaces in all generations
 234   void record_gen_tops_before_GC() PRODUCT_RETURN;
 235 
 236   // Mangle the unused parts of all spaces in the heap
 237   void gen_mangle_unused_area() PRODUCT_RETURN;
 238 
 239   // Call these in sequential code around the processing of strong roots.
 240   class ParStrongRootsScope : public MarkScope {
 241    public:
 242     ParStrongRootsScope();
 243     ~ParStrongRootsScope();
 244   };
 245 };
 246 
 247 // Simple class for storing info about the heap at the start of GC, to be used
 248 // after GC for comparison/printing.
 249 class PreGCValues {
 250 public:
 251   PreGCValues(ParallelScavengeHeap* heap) :
 252       _heap_used(heap->used()),
 253       _young_gen_used(heap->young_gen()->used_in_bytes()),
 254       _old_gen_used(heap->old_gen()->used_in_bytes()),
 255       _metadata_used(MetaspaceAux::used_bytes()) { };
 256 
 257   size_t heap_used() const      { return _heap_used; }
 258   size_t young_gen_used() const { return _young_gen_used; }
 259   size_t old_gen_used() const   { return _old_gen_used; }
 260   size_t metadata_used() const  { return _metadata_used; }
 261 
 262 private:
 263   size_t _heap_used;
 264   size_t _young_gen_used;
 265   size_t _old_gen_used;
 266   size_t _metadata_used;
 267 };
 268 
 269 #endif // SHARE_VM_GC_PARALLEL_PARALLELSCAVENGEHEAP_HPP
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