1 /*
   2  * Copyright (c) 2001, 2018, 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
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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 GCTaskManager;
  45 class MemoryManager;
  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* _young_manager;
  71   GCMemoryManager* _old_manager;
  72 
  73   MemoryPool* _eden_pool;
  74   MemoryPool* _survivor_pool;
  75   MemoryPool* _old_pool;
  76 
  77   virtual void initialize_serviceability();
  78 
  79   void trace_heap(GCWhen::Type when, const GCTracer* tracer);
  80 
  81  protected:
  82   static inline size_t total_invocations();
  83   HeapWord* allocate_new_tlab(size_t size);
  84 
  85   inline bool should_alloc_in_eden(size_t size) const;
  86   inline void death_march_check(HeapWord* const result, size_t size);
  87   HeapWord* mem_allocate_old_gen(size_t size);
  88 
  89  public:
  90   ParallelScavengeHeap(GenerationSizer* policy) :
  91     CollectedHeap(), _collector_policy(policy), _death_march_count(0) { }
  92 
  93   // For use by VM operations
  94   enum CollectionType {
  95     Scavenge,
  96     MarkSweep
  97   };
  98 
  99   virtual Name kind() const {
 100     return CollectedHeap::ParallelScavengeHeap;
 101   }
 102 
 103   virtual const char* name() const {
 104     return "Parallel";
 105   }
 106 
 107   virtual CollectorPolicy* collector_policy() const { return _collector_policy; }
 108 
 109   virtual GrowableArray<GCMemoryManager*> memory_managers();
 110   virtual GrowableArray<MemoryPool*> memory_pools();
 111 
 112   static PSYoungGen* young_gen() { return _young_gen; }
 113   static PSOldGen* old_gen()     { return _old_gen; }
 114 
 115   virtual PSAdaptiveSizePolicy* size_policy() { return _size_policy; }
 116 
 117   static PSGCAdaptivePolicyCounters* gc_policy_counters() { return _gc_policy_counters; }
 118 
 119   static ParallelScavengeHeap* heap();
 120 
 121   static GCTaskManager* const gc_task_manager() { return _gc_task_manager; }
 122 
 123   AdjoiningGenerations* gens() { return _gens; }
 124 
 125   // Returns JNI_OK on success
 126   virtual jint initialize();
 127 
 128   void post_initialize();
 129   void update_counters();
 130 
 131   // The alignment used for the various areas
 132   size_t space_alignment()      { return _collector_policy->space_alignment(); }
 133   size_t generation_alignment() { return _collector_policy->gen_alignment(); }
 134 
 135   // Return the (conservative) maximum heap alignment
 136   static size_t conservative_max_heap_alignment() {
 137     return CollectorPolicy::compute_heap_alignment();
 138   }
 139 
 140   size_t capacity() const;
 141   size_t used() const;
 142 
 143   // Return "true" if all generations have reached the
 144   // maximal committed limit that they can reach, without a garbage
 145   // collection.
 146   virtual bool is_maximal_no_gc() const;
 147 
 148   // Return true if the reference points to an object that
 149   // can be moved in a partial collection.  For currently implemented
 150   // generational collectors that means during a collection of
 151   // the young gen.
 152   virtual bool is_scavengable(oop obj);
 153   virtual void register_nmethod(nmethod* nm);
 154   virtual void verify_nmethod(nmethod* nmethod);
 155 
 156   size_t max_capacity() const;
 157 
 158   // Whether p is in the allocated part of the heap
 159   bool is_in(const void* p) const;
 160 
 161   bool is_in_reserved(const void* p) const;
 162 
 163   bool is_in_young(oop p);  // reserved part
 164   bool is_in_old(oop p);    // reserved part
 165 
 166   // Memory allocation.   "gc_time_limit_was_exceeded" will
 167   // be set to true if the adaptive size policy determine that
 168   // an excessive amount of time is being spent doing collections
 169   // and caused a NULL to be returned.  If a NULL is not returned,
 170   // "gc_time_limit_was_exceeded" has an undefined meaning.
 171   HeapWord* mem_allocate(size_t size, bool* gc_overhead_limit_was_exceeded);
 172 
 173   // Allocation attempt(s) during a safepoint. It should never be called
 174   // to allocate a new TLAB as this allocation might be satisfied out
 175   // of the old generation.
 176   HeapWord* failed_mem_allocate(size_t size);
 177 
 178   // Support for System.gc()
 179   void collect(GCCause::Cause cause);
 180 
 181   // These also should be called by the vm thread at a safepoint (e.g., from a
 182   // VM operation).
 183   //
 184   // The first collects the young generation only, unless the scavenge fails; it
 185   // will then attempt a full gc.  The second collects the entire heap; if
 186   // maximum_compaction is true, it will compact everything and clear all soft
 187   // references.
 188   inline void invoke_scavenge();
 189 
 190   // Perform a full collection
 191   virtual void do_full_collection(bool clear_all_soft_refs);
 192 
 193   bool supports_inline_contig_alloc() const { return !UseNUMA; }
 194 
 195   HeapWord* volatile* top_addr() const { return !UseNUMA ? young_gen()->top_addr() : (HeapWord* volatile*)-1; }
 196   HeapWord** end_addr() const { return !UseNUMA ? young_gen()->end_addr() : (HeapWord**)-1; }
 197 
 198   void ensure_parsability(bool retire_tlabs);
 199   void accumulate_statistics_all_tlabs();
 200   void resize_all_tlabs();
 201 
 202   bool supports_tlab_allocation() const { return true; }
 203 
 204   size_t tlab_capacity(Thread* thr) const;
 205   size_t tlab_used(Thread* thr) const;
 206   size_t unsafe_max_tlab_alloc(Thread* thr) const;
 207 
 208   void object_iterate(ObjectClosure* cl);
 209   void safe_object_iterate(ObjectClosure* cl) { object_iterate(cl); }
 210 
 211   HeapWord* block_start(const void* addr) const;
 212   size_t block_size(const HeapWord* addr) const;
 213   bool block_is_obj(const HeapWord* addr) const;
 214 
 215   jlong millis_since_last_gc();
 216 
 217   void prepare_for_verify();
 218   PSHeapSummary create_ps_heap_summary();
 219   virtual void print_on(outputStream* st) const;
 220   virtual void print_on_error(outputStream* st) const;
 221   virtual void print_gc_threads_on(outputStream* st) const;
 222   virtual void gc_threads_do(ThreadClosure* tc) const;
 223   virtual void print_tracing_info() const;
 224 
 225   void verify(VerifyOption option /* ignored */);
 226 
 227   // Resize the young generation.  The reserved space for the
 228   // generation may be expanded in preparation for the resize.
 229   void resize_young_gen(size_t eden_size, size_t survivor_size);
 230 
 231   // Resize the old generation.  The reserved space for the
 232   // generation may be expanded in preparation for the resize.
 233   void resize_old_gen(size_t desired_free_space);
 234 
 235   // Save the tops of the spaces in all generations
 236   void record_gen_tops_before_GC() PRODUCT_RETURN;
 237 
 238   // Mangle the unused parts of all spaces in the heap
 239   void gen_mangle_unused_area() PRODUCT_RETURN;
 240 
 241   // Call these in sequential code around the processing of strong roots.
 242   class ParStrongRootsScope : public MarkScope {
 243    public:
 244     ParStrongRootsScope();
 245     ~ParStrongRootsScope();
 246   };
 247 
 248   GCMemoryManager* old_gc_manager() const { return _old_manager; }
 249   GCMemoryManager* young_gc_manager() const { return _young_manager; }
 250 };
 251 
 252 // Simple class for storing info about the heap at the start of GC, to be used
 253 // after GC for comparison/printing.
 254 class PreGCValues {
 255 public:
 256   PreGCValues(ParallelScavengeHeap* heap) :
 257       _heap_used(heap->used()),
 258       _young_gen_used(heap->young_gen()->used_in_bytes()),
 259       _old_gen_used(heap->old_gen()->used_in_bytes()),
 260       _metadata_used(MetaspaceAux::used_bytes()) { };
 261 
 262   size_t heap_used() const      { return _heap_used; }
 263   size_t young_gen_used() const { return _young_gen_used; }
 264   size_t old_gen_used() const   { return _old_gen_used; }
 265   size_t metadata_used() const  { return _metadata_used; }
 266 
 267 private:
 268   size_t _heap_used;
 269   size_t _young_gen_used;
 270   size_t _old_gen_used;
 271   size_t _metadata_used;
 272 };
 273 
 274 // Class that can be used to print information about the
 275 // adaptive size policy at intervals specified by
 276 // AdaptiveSizePolicyOutputInterval.  Only print information
 277 // if an adaptive size policy is in use.
 278 class AdaptiveSizePolicyOutput : AllStatic {
 279   static bool enabled() {
 280     return UseParallelGC &&
 281            UseAdaptiveSizePolicy &&
 282            log_is_enabled(Debug, gc, ergo);
 283   }
 284  public:
 285   static void print() {
 286     if (enabled()) {
 287       ParallelScavengeHeap::heap()->size_policy()->print();
 288     }
 289   }
 290 
 291   static void print(AdaptiveSizePolicy* size_policy, uint count) {
 292     bool do_print =
 293         enabled() &&
 294         (AdaptiveSizePolicyOutputInterval > 0) &&
 295         (count % AdaptiveSizePolicyOutputInterval) == 0;
 296 
 297     if (do_print) {
 298       size_policy->print();
 299     }
 300   }
 301 };
 302 
 303 #endif // SHARE_VM_GC_PARALLEL_PARALLELSCAVENGEHEAP_HPP