/*

 * 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