src/hotspot/share/jfr/recorder/storage/jfrMemorySpace.hpp

/*
 * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
 * 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.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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#ifndef SHARE_VM_JFR_RECORDER_STORAGE_JFRMEMORYSPACE_HPP
#define SHARE_VM_JFR_RECORDER_STORAGE_JFRMEMORYSPACE_HPP

#include "jfr/utilities/jfrAllocation.hpp"
#include "jfr/utilities/jfrDoublyLinkedList.hpp"
#include "jfr/utilities/jfrIterator.hpp"
#include "jfr/utilities/jfrTypes.hpp"
#include "runtime/os.hpp"
#include "utilities/globalDefinitions.hpp"
#include "utilities/macros.hpp"

template <typename T, template <typename> class RetrievalType, typename Callback>
class JfrMemorySpace : public JfrCHeapObj {
 public:
  typedef T Type;
  typedef RetrievalType<JfrMemorySpace<T, RetrievalType, Callback> > Retrieval;
  typedef JfrDoublyLinkedList<Type> List;
  typedef StopOnNullIterator<List> Iterator;
 private:
  List _free;
  List _full;
  size_t _min_elem_size;
  size_t _limit_size;
  size_t _cache_count;
  Callback* _callback;

  bool should_populate_cache() const { return _free.count() < _cache_count; }

 public:
  JfrMemorySpace(size_t min_elem_size, size_t limit_size, size_t cache_count, Callback* callback);
  ~JfrMemorySpace();
  bool initialize();

  size_t min_elem_size() const { return _min_elem_size; }
  size_t limit_size() const { return _limit_size; }

  bool has_full() const { return _full.head() != NULL; }
  bool has_free() const { return _free.head() != NULL; }
  bool is_full_empty() const { return !has_full(); }
  bool is_free_empty() const { return !has_free(); }

  size_t full_count() const { return _full.count(); }
  size_t free_count() const { return _free.count(); }

  List& full() { return _full; }
  const List& full() const { return _full; }
  List& free() { return _free; }
  const List& free() const { return _free; }

  Type* full_head() { return _full.head(); }
  Type* full_tail() { return _full.tail(); }
  Type* free_head() { return _free.head(); }
  Type* free_tail() { return _free.tail(); }

  void insert_free_head(Type* t) { _free.prepend(t); }
  void insert_free_tail(Type* t) { _free.append(t); }
  void insert_free_tail(Type* t, Type* tail, size_t count) { _free.append_list(t, tail, count); }
  void insert_full_head(Type* t) { _full.prepend(t); }
  void insert_full_tail(Type* t) { _full.append(t); }
  void insert_full_tail(Type* t, Type* tail, size_t count) { _full.append_list(t, tail, count); }

  Type* remove_free(Type* t) { return _free.remove(t); }
  Type* remove_full(Type* t) { return _full.remove(t); }
  Type* remove_free_tail() { _free.remove(_free.tail()); }
  Type* remove_full_tail() { return _full.remove(_full.tail()); }
  Type* clear_full(bool return_tail = false) { return _full.clear(return_tail); }
  Type* clear_free(bool return_tail = false) { return _free.clear(return_tail); }
  void release_full(Type* t);
  void release_free(Type* t);

  void register_full(Type* t, Thread* thread) { _callback->register_full(t, thread); }
  void lock() { _callback->lock(); }
  void unlock() { _callback->unlock(); }
  DEBUG_ONLY(bool is_locked() const { return _callback->is_locked(); })

  Type* allocate(size_t size);
  void deallocate(Type* t);
  Type* get(size_t size, Thread* thread) { return Retrieval::get(size, this, thread); }

  template <typename IteratorCallback, typename IteratorType>
  void iterate(IteratorCallback& callback, bool full = true, jfr_iter_direction direction = forward);

  debug_only(bool in_full_list(const Type* t) const { return _full.in_list(t); })
  debug_only(bool in_free_list(const Type* t) const { return _free.in_list(t); })
};

// allocations are even multiples of the mspace min size
inline u8 align_allocation_size(u8 requested_size, size_t min_elem_size) {
  assert((int)min_elem_size % os::vm_page_size() == 0, "invariant");
  u8 alloc_size_bytes = min_elem_size;
  while (requested_size > alloc_size_bytes) {
    alloc_size_bytes <<= 1;
  }
  assert((int)alloc_size_bytes % os::vm_page_size() == 0, "invariant");
  return alloc_size_bytes;
}

template <typename T, template <typename> class RetrievalType, typename Callback>
T* JfrMemorySpace<T, RetrievalType, Callback>::allocate(size_t size) {
  const u8 aligned_size_bytes = align_allocation_size(size, _min_elem_size);
  void* const allocation = JfrCHeapObj::new_array<u1>(aligned_size_bytes + sizeof(T));
  if (allocation == NULL) {
    return NULL;
  }
  T* const t = new (allocation) T;
  assert(t != NULL, "invariant");
  if (!t->initialize(sizeof(T), aligned_size_bytes)) {
    JfrCHeapObj::free(t, aligned_size_bytes + sizeof(T));
    return NULL;
  }
  return t;
}

template <typename T, template <typename> class RetrievalType, typename Callback>
void JfrMemorySpace<T, RetrievalType, Callback>::deallocate(T* t) {
  assert(t != NULL, "invariant");
  assert(!_free.in_list(t), "invariant");
  assert(!_full.in_list(t), "invariant");
  assert(t != NULL, "invariant");
  JfrCHeapObj::free(t, t->total_size());
}

template <typename Mspace>
class MspaceLock {
 private:
  Mspace* _mspace;
 public:
  MspaceLock(Mspace* mspace) : _mspace(mspace) { _mspace->lock(); }
  ~MspaceLock() { _mspace->unlock(); }
};

template <typename Mspace>
class ReleaseOp : public StackObj {
 private:
  Mspace* _mspace;
  Thread* _thread;
  bool _release_full;
 public:
  typedef typename Mspace::Type Type;
  ReleaseOp(Mspace* mspace, Thread* thread, bool release_full = true) : _mspace(mspace), _thread(thread), _release_full(release_full) {}
  bool process(Type* t);
  size_t processed() const { return 0; }
};

#endif // SHARE_VM_JFR_RECORDER_STORAGE_JFRMEMORYSPACE_HPP