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_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/growableArray.hpp"
  40 #include "utilities/ostream.hpp"
  41 
  42 class AdjoiningGenerations;
  43 class GCHeapSummary;
  44 class GCMemoryManager;
  45 class GCTaskManager;
  46 class MemoryPool;
  47 class PSAdaptiveSizePolicy;
  48 class PSHeapSummary;
  49 
  50 class ParallelScavengeHeap : public CollectedHeap {
  51   friend class VMStructs;
  52  private:
  53   static PSYoungGen* _young_gen;
  54   static PSOldGen*   _old_gen;
  55 
  56   // Sizing policy for entire heap
  57   static PSAdaptiveSizePolicy*       _size_policy;
  58   static PSGCAdaptivePolicyCounters* _gc_policy_counters;
  59 
  60   GenerationSizer* _collector_policy;
  61 
  62   // Collection of generations that are adjacent in the
  63   // space reserved for the heap.
  64   AdjoiningGenerations* _gens;
  65   unsigned int _death_march_count;
  66 
  67   // The task manager
  68   static GCTaskManager* _gc_task_manager;
  69 
  70   GCMemoryManager* _minor_mgr;
  71   GCMemoryManager* _major_mgr;
  72 
  73   void trace_heap(GCWhen::Type when, const GCTracer* tracer);
  74 
  75  protected:
  76   static inline size_t total_invocations();
  77   HeapWord* allocate_new_tlab(size_t size);
  78 
  79   inline bool should_alloc_in_eden(size_t size) const;
  80   inline void death_march_check(HeapWord* const result, size_t size);
  81   HeapWord* mem_allocate_old_gen(size_t size);
  82 
  83  public:
  84   ParallelScavengeHeap(GenerationSizer* policy) :
  85     CollectedHeap(), _collector_policy(policy), _death_march_count(0) { }
  86 
  87   // For use by VM operations
  88   enum CollectionType {
  89     Scavenge,
  90     MarkSweep
  91   };
  92 
  93   virtual Name kind() const {
  94     return CollectedHeap::ParallelScavengeHeap;
  95   }
  96 
  97   virtual const char* name() const {
  98     return "Parallel";
  99   }
 100 
 101   virtual CollectorPolicy* collector_policy() const { return _collector_policy; }
 102 
 103   virtual GrowableArray<GCMemoryManager*> memory_managers();
 104   virtual GrowableArray<MemoryPool*> memory_pools();
 105 
 106   static PSYoungGen* young_gen() { return _young_gen; }
 107   static PSOldGen* old_gen()     { return _old_gen; }
 108 
 109   virtual PSAdaptiveSizePolicy* size_policy() { return _size_policy; }
 110 
 111   static PSGCAdaptivePolicyCounters* gc_policy_counters() { return _gc_policy_counters; }
 112 
 113   static ParallelScavengeHeap* heap();
 114 
 115   static GCTaskManager* const gc_task_manager() { return _gc_task_manager; }
 116 
 117   AdjoiningGenerations* gens() { return _gens; }
 118 
 119   // Returns JNI_OK on success
 120   virtual jint initialize();
 121 
 122   void post_initialize();
 123   void update_counters();
 124 
 125   // The alignment used for the various areas
 126   size_t space_alignment()      { return _collector_policy->space_alignment(); }
 127   size_t generation_alignment() { return _collector_policy->gen_alignment(); }
 128 
 129   // Return the (conservative) maximum heap alignment
 130   static size_t conservative_max_heap_alignment() {
 131     return CollectorPolicy::compute_heap_alignment();
 132   }
 133 
 134   size_t capacity() const;
 135   size_t used() const;
 136 
 137   // Return "true" if all generations have reached the
 138   // maximal committed limit that they can reach, without a garbage
 139   // collection.
 140   virtual bool is_maximal_no_gc() const;
 141 
 142   // Return true if the reference points to an object that
 143   // can be moved in a partial collection.  For currently implemented
 144   // generational collectors that means during a collection of
 145   // the young gen.
 146   virtual bool is_scavengable(oop obj);
 147   virtual void register_nmethod(nmethod* nm);
 148   virtual void verify_nmethod(nmethod* nmethod);
 149 
 150   size_t max_capacity() const;
 151 
 152   // Whether p is in the allocated part of the heap
 153   bool is_in(const void* p) const;
 154 
 155   bool is_in_reserved(const void* p) const;
 156 
 157   bool is_in_young(oop p);  // reserved part
 158   bool is_in_old(oop p);    // reserved part
 159 
 160   // Memory allocation.   "gc_time_limit_was_exceeded" will
 161   // be set to true if the adaptive size policy determine that
 162   // an excessive amount of time is being spent doing collections
 163   // and caused a NULL to be returned.  If a NULL is not returned,
 164   // "gc_time_limit_was_exceeded" has an undefined meaning.
 165   HeapWord* mem_allocate(size_t size, bool* gc_overhead_limit_was_exceeded);
 166 
 167   // Allocation attempt(s) during a safepoint. It should never be called
 168   // to allocate a new TLAB as this allocation might be satisfied out
 169   // of the old generation.
 170   HeapWord* failed_mem_allocate(size_t size);
 171 
 172   // Support for System.gc()
 173   void collect(GCCause::Cause cause);
 174 
 175   // These also should be called by the vm thread at a safepoint (e.g., from a
 176   // VM operation).
 177   //
 178   // The first collects the young generation only, unless the scavenge fails; it
 179   // will then attempt a full gc.  The second collects the entire heap; if
 180   // maximum_compaction is true, it will compact everything and clear all soft
 181   // references.
 182   inline void invoke_scavenge();
 183 
 184   // Perform a full collection
 185   virtual void do_full_collection(bool clear_all_soft_refs);
 186 
 187   bool supports_inline_contig_alloc() const { return !UseNUMA; }
 188 
 189   HeapWord* volatile* top_addr() const { return !UseNUMA ? young_gen()->top_addr() : (HeapWord* volatile*)-1; }
 190   HeapWord** end_addr() const { return !UseNUMA ? young_gen()->end_addr() : (HeapWord**)-1; }
 191 
 192   void ensure_parsability(bool retire_tlabs);
 193   void accumulate_statistics_all_tlabs();
 194   void resize_all_tlabs();
 195 
 196   bool supports_tlab_allocation() const { return true; }
 197 
 198   size_t tlab_capacity(Thread* thr) const;
 199   size_t tlab_used(Thread* thr) const;
 200   size_t unsafe_max_tlab_alloc(Thread* thr) const;
 201 
 202   // Can a compiler initialize a new object without store barriers?
 203   // This permission only extends from the creation of a new object
 204   // via a TLAB up to the first subsequent safepoint.
 205   virtual bool can_elide_tlab_store_barriers() const {
 206     return true;
 207   }
 208 
 209   virtual bool card_mark_must_follow_store() const {
 210     return false;
 211   }
 212 
 213   // Return true if we don't we need a store barrier for
 214   // initializing stores to an object at this address.
 215   virtual bool can_elide_initializing_store_barrier(oop new_obj);
 216 
 217   void object_iterate(ObjectClosure* cl);
 218   void safe_object_iterate(ObjectClosure* cl) { object_iterate(cl); }
 219 
 220   HeapWord* block_start(const void* addr) const;
 221   size_t block_size(const HeapWord* addr) const;
 222   bool block_is_obj(const HeapWord* addr) const;
 223 
 224   jlong millis_since_last_gc();
 225 
 226   void prepare_for_verify();
 227   PSHeapSummary create_ps_heap_summary();
 228   virtual void print_on(outputStream* st) const;
 229   virtual void print_on_error(outputStream* st) const;
 230   virtual void print_gc_threads_on(outputStream* st) const;
 231   virtual void gc_threads_do(ThreadClosure* tc) const;
 232   virtual void print_tracing_info() const;
 233 
 234   void verify(VerifyOption option /* ignored */);
 235 
 236   // Resize the young generation.  The reserved space for the
 237   // generation may be expanded in preparation for the resize.
 238   void resize_young_gen(size_t eden_size, size_t survivor_size);
 239 
 240   // Resize the old generation.  The reserved space for the
 241   // generation may be expanded in preparation for the resize.
 242   void resize_old_gen(size_t desired_free_space);
 243 
 244   // Save the tops of the spaces in all generations
 245   void record_gen_tops_before_GC() PRODUCT_RETURN;
 246 
 247   // Mangle the unused parts of all spaces in the heap
 248   void gen_mangle_unused_area() PRODUCT_RETURN;
 249 
 250   // Call these in sequential code around the processing of strong roots.
 251   class ParStrongRootsScope : public MarkScope {
 252    public:
 253     ParStrongRootsScope();
 254     ~ParStrongRootsScope();
 255   };
 256 };
 257 
 258 // Simple class for storing info about the heap at the start of GC, to be used
 259 // after GC for comparison/printing.
 260 class PreGCValues {
 261 public:
 262   PreGCValues(ParallelScavengeHeap* heap) :
 263       _heap_used(heap->used()),
 264       _young_gen_used(heap->young_gen()->used_in_bytes()),
 265       _old_gen_used(heap->old_gen()->used_in_bytes()),
 266       _metadata_used(MetaspaceAux::used_bytes()) { };
 267 
 268   size_t heap_used() const      { return _heap_used; }
 269   size_t young_gen_used() const { return _young_gen_used; }
 270   size_t old_gen_used() const   { return _old_gen_used; }
 271   size_t metadata_used() const  { return _metadata_used; }
 272 
 273 private:
 274   size_t _heap_used;
 275   size_t _young_gen_used;
 276   size_t _old_gen_used;
 277   size_t _metadata_used;
 278 };
 279 
 280 // Class that can be used to print information about the
 281 // adaptive size policy at intervals specified by
 282 // AdaptiveSizePolicyOutputInterval.  Only print information
 283 // if an adaptive size policy is in use.
 284 class AdaptiveSizePolicyOutput : AllStatic {
 285   static bool enabled() {
 286     return UseParallelGC &&
 287            UseAdaptiveSizePolicy &&
 288            log_is_enabled(Debug, gc, ergo);
 289   }
 290  public:
 291   static void print() {
 292     if (enabled()) {
 293       ParallelScavengeHeap::heap()->size_policy()->print();
 294     }
 295   }
 296 
 297   static void print(AdaptiveSizePolicy* size_policy, uint count) {
 298     bool do_print =
 299         enabled() &&
 300         (AdaptiveSizePolicyOutputInterval > 0) &&
 301         (count % AdaptiveSizePolicyOutputInterval) == 0;
 302 
 303     if (do_print) {
 304       size_policy->print();
 305     }
 306   }
 307 };
 308 
 309 #endif // SHARE_VM_GC_PARALLEL_PARALLELSCAVENGEHEAP_HPP