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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

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#ifndef SHARE_VM_GC_PARALLEL_PARALLELSCAVENGEHEAP_HPP

#define SHARE_VM_GC_PARALLEL_PARALLELSCAVENGEHEAP_HPP

#include "gc/parallel/generationSizer.hpp"

#include "gc/parallel/objectStartArray.hpp"

#include "gc/parallel/psGCAdaptivePolicyCounters.hpp"

#include "gc/parallel/psOldGen.hpp"

#include "gc/parallel/psYoungGen.hpp"

#include "gc/shared/collectedHeap.hpp"

#include "gc/shared/collectorPolicy.hpp"

#include "gc/shared/gcPolicyCounters.hpp"

#include "gc/shared/gcWhen.hpp"

#include "gc/shared/strongRootsScope.hpp"

#include "memory/metaspace.hpp"

#include "utilities/growableArray.hpp"

#include "utilities/ostream.hpp"

class AdjoiningGenerations;

class GCHeapSummary;

class GCTaskManager;

class MemoryManager;

class MemoryPool;

class PSAdaptiveSizePolicy;

class PSHeapSummary;

class ParallelScavengeHeap : public CollectedHeap {

  friend class VMStructs;

 private:

  static PSYoungGen* _young_gen;

  static PSOldGen*   _old_gen;

  // Sizing policy for entire heap

  static PSAdaptiveSizePolicy*       _size_policy;

  static PSGCAdaptivePolicyCounters* _gc_policy_counters;

  GenerationSizer* _collector_policy;

  // Collection of generations that are adjacent in the

  // space reserved for the heap.

  AdjoiningGenerations* _gens;

  unsigned int _death_march_count;

  // The task manager

  static GCTaskManager* _gc_task_manager;

  GCMemoryManager* _young_manager;

  GCMemoryManager* _old_manager;

  MemoryPool* _eden_pool;

  MemoryPool* _survivor_pool;

  MemoryPool* _old_pool;

  virtual void initialize_serviceability();

  void trace_heap(GCWhen::Type when, const GCTracer* tracer);

 protected:

  static inline size_t total_invocations();

  HeapWord* allocate_new_tlab(size_t size);

  inline bool should_alloc_in_eden(size_t size) const;

  inline void death_march_check(HeapWord* const result, size_t size);

  HeapWord* mem_allocate_old_gen(size_t size);

 public:

  ParallelScavengeHeap(GenerationSizer* policy) :

    CollectedHeap(), _collector_policy(policy), _death_march_count(0) { }

  // For use by VM operations

  enum CollectionType {

    Scavenge,

    MarkSweep

  };

  virtual Name kind() const {

    return CollectedHeap::ParallelScavengeHeap;

  }

  virtual const char* name() const {

    return "Parallel";

  }

  virtual CollectorPolicy* collector_policy() const { return _collector_policy; }

  virtual GrowableArray<GCMemoryManager*> memory_managers();

  virtual GrowableArray<MemoryPool*> memory_pools();

  static PSYoungGen* young_gen() { return _young_gen; }

  static PSOldGen* old_gen()     { return _old_gen; }

  virtual PSAdaptiveSizePolicy* size_policy() { return _size_policy; }

  static PSGCAdaptivePolicyCounters* gc_policy_counters() { return _gc_policy_counters; }

  static ParallelScavengeHeap* heap();

  static GCTaskManager* const gc_task_manager() { return _gc_task_manager; }

  AdjoiningGenerations* gens() { return _gens; }

  // Returns JNI_OK on success

  virtual jint initialize();

  void post_initialize();

  void update_counters();

  // The alignment used for the various areas

  size_t space_alignment()      { return _collector_policy->space_alignment(); }

  size_t generation_alignment() { return _collector_policy->gen_alignment(); }

  // Return the (conservative) maximum heap alignment

  static size_t conservative_max_heap_alignment() {

    return CollectorPolicy::compute_heap_alignment();

  }

  size_t capacity() const;

  size_t used() const;

  // Return "true" if all generations have reached the

  // maximal committed limit that they can reach, without a garbage

  // collection.

  virtual bool is_maximal_no_gc() const;

  // Return true if the reference points to an object that

  // can be moved in a partial collection.  For currently implemented

  // generational collectors that means during a collection of

  // the young gen.

  virtual bool is_scavengable(oop obj);

  virtual void register_nmethod(nmethod* nm);

  virtual void verify_nmethod(nmethod* nmethod);

  size_t max_capacity() const;

  // Whether p is in the allocated part of the heap

  bool is_in(const void* p) const;

  bool is_in_reserved(const void* p) const;

  bool is_in_young(oop p);  // reserved part

  bool is_in_old(oop p);    // reserved part

  // Memory allocation.   "gc_time_limit_was_exceeded" will

  // be set to true if the adaptive size policy determine that

  // an excessive amount of time is being spent doing collections

  // and caused a NULL to be returned.  If a NULL is not returned,

  // "gc_time_limit_was_exceeded" has an undefined meaning.

  HeapWord* mem_allocate(size_t size, bool* gc_overhead_limit_was_exceeded);

  // Allocation attempt(s) during a safepoint. It should never be called

  // to allocate a new TLAB as this allocation might be satisfied out

  // of the old generation.

  HeapWord* failed_mem_allocate(size_t size);

  // Support for System.gc()

  void collect(GCCause::Cause cause);

  // These also should be called by the vm thread at a safepoint (e.g., from a

  // VM operation).

  //

  // The first collects the young generation only, unless the scavenge fails; it

  // will then attempt a full gc.  The second collects the entire heap; if

  // maximum_compaction is true, it will compact everything and clear all soft

  // references.

  inline void invoke_scavenge();

  // Perform a full collection

  virtual void do_full_collection(bool clear_all_soft_refs);

  bool supports_inline_contig_alloc() const { return !UseNUMA; }

  HeapWord* volatile* top_addr() const { return !UseNUMA ? young_gen()->top_addr() : (HeapWord* volatile*)-1; }

  HeapWord** end_addr() const { return !UseNUMA ? young_gen()->end_addr() : (HeapWord**)-1; }

  void ensure_parsability(bool retire_tlabs);

  void accumulate_statistics_all_tlabs();

  void resize_all_tlabs();

  bool supports_tlab_allocation() const { return true; }

  size_t tlab_capacity(Thread* thr) const;

  size_t tlab_used(Thread* thr) const;

  size_t unsafe_max_tlab_alloc(Thread* thr) const;

  // Can a compiler initialize a new object without store barriers?

  // This permission only extends from the creation of a new object

  // via a TLAB up to the first subsequent safepoint.

  virtual bool can_elide_tlab_store_barriers() const {

    return true;

  }

  virtual bool card_mark_must_follow_store() const {

    return false;

  }

  // Return true if we don't we need a store barrier for

  // initializing stores to an object at this address.

  virtual bool can_elide_initializing_store_barrier(oop new_obj);

  void object_iterate(ObjectClosure* cl);

  void safe_object_iterate(ObjectClosure* cl) { object_iterate(cl); }

  HeapWord* block_start(const void* addr) const;

  size_t block_size(const HeapWord* addr) const;

  bool block_is_obj(const HeapWord* addr) const;

  jlong millis_since_last_gc();

  void prepare_for_verify();

  PSHeapSummary create_ps_heap_summary();

  virtual void print_on(outputStream* st) const;

  virtual void print_on_error(outputStream* st) const;

  virtual void print_gc_threads_on(outputStream* st) const;

  virtual void gc_threads_do(ThreadClosure* tc) const;

  virtual void print_tracing_info() const;

  void verify(VerifyOption option /* ignored */);

  // Resize the young generation.  The reserved space for the

  // generation may be expanded in preparation for the resize.

  void resize_young_gen(size_t eden_size, size_t survivor_size);

  // Resize the old generation.  The reserved space for the

  // generation may be expanded in preparation for the resize.

  void resize_old_gen(size_t desired_free_space);

  // Save the tops of the spaces in all generations

  void record_gen_tops_before_GC() PRODUCT_RETURN;

  // Mangle the unused parts of all spaces in the heap

  void gen_mangle_unused_area() PRODUCT_RETURN;

  // Call these in sequential code around the processing of strong roots.

  class ParStrongRootsScope : public MarkScope {

   public:

    ParStrongRootsScope();

    ~ParStrongRootsScope();

  };

  GCMemoryManager* old_gc_manager() const { return _old_manager; }

  GCMemoryManager* young_gc_manager() const { return _young_manager; }

};

// Simple class for storing info about the heap at the start of GC, to be used

// after GC for comparison/printing.

class PreGCValues {

public:

  PreGCValues(ParallelScavengeHeap* heap) :

      _heap_used(heap->used()),

      _young_gen_used(heap->young_gen()->used_in_bytes()),

      _old_gen_used(heap->old_gen()->used_in_bytes()),

      _metadata_used(MetaspaceAux::used_bytes()) { };

  size_t heap_used() const      { return _heap_used; }

  size_t young_gen_used() const { return _young_gen_used; }

  size_t old_gen_used() const   { return _old_gen_used; }

  size_t metadata_used() const  { return _metadata_used; }

private:

  size_t _heap_used;

  size_t _young_gen_used;

  size_t _old_gen_used;

  size_t _metadata_used;

};

// Class that can be used to print information about the

// adaptive size policy at intervals specified by

// AdaptiveSizePolicyOutputInterval.  Only print information

// if an adaptive size policy is in use.

class AdaptiveSizePolicyOutput : AllStatic {

  static bool enabled() {

    return UseParallelGC &&

           UseAdaptiveSizePolicy &&

           log_is_enabled(Debug, gc, ergo);

  }

 public:

  static void print() {

    if (enabled()) {

      ParallelScavengeHeap::heap()->size_policy()->print();

    }

  }

  static void print(AdaptiveSizePolicy* size_policy, uint count) {

    bool do_print =

        enabled() &&

        (AdaptiveSizePolicyOutputInterval > 0) &&

        (count % AdaptiveSizePolicyOutputInterval) == 0;

    if (do_print) {

      size_policy->print();

    }

  }

};

#endif // SHARE_VM_GC_PARALLEL_PARALLELSCAVENGEHEAP_HPP