--- /dev/null	2019-01-28 17:47:49.000000000 +0800
+++ new/src/share/vm/jfr/recorder/storage/jfrMemorySpace.hpp	2019-01-28 17:47:49.000000000 +0800
@@ -0,0 +1,186 @@
+/*
+ * Copyright (c) 2016, 2019, 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
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+#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(Type* t);
+
+  void register_full(Type* t, Thread* thread) { _callback->register_full(t, thread); }
+  void lock() { _callback->lock(); }
+  void unlock() { _callback->unlock(); }
+
+  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;
+ public:
+  typedef typename Mspace::Type Type;
+  ReleaseOp(Mspace* mspace) : _mspace(mspace) {}
+  bool process(Type* t);
+  size_t processed() const { return 0; }
+};
+
+template <typename Mspace>
+class MutexedReleaseOp : public ReleaseOp<Mspace> {
+ private:
+  Thread* _thread;
+ public:
+  typedef typename Mspace::Type Type;
+  MutexedReleaseOp(Mspace* mspace, Thread* thread) : ReleaseOp<Mspace>(mspace), _thread(thread) {}
+  bool process(Type* t);
+  size_t processed() const { return ReleaseOp<Mspace>::processed(); }
+};
+
+template <typename Mspace>
+class ThreadLocalReleaseOp : public StackObj {
+ private:
+  Mspace* _mspace;
+ public:
+  typedef typename Mspace::Type Type;
+  ThreadLocalReleaseOp(Mspace* mspace) : _mspace(mspace) {}
+  bool process(Type* t);
+  size_t processed() const { return 0; }
+};
+
+#endif // SHARE_VM_JFR_RECORDER_STORAGE_JFRMEMORYSPACE_HPP