1 /*
   2  * Copyright (c) 2017, 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
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  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
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_JFR_LEAKPROFILER_SAMPLING_SAMPLELIST_HPP
  26 #define SHARE_VM_JFR_LEAKPROFILER_SAMPLING_SAMPLELIST_HPP
  27 #include "jfr/utilities/jfrAllocation.hpp"
  28 #include "jfr/utilities/jfrDoublyLinkedList.hpp"
  29 
  30 class ObjectSample;
  31 
  32 class SampleList : public JfrCHeapObj {
  33   typedef JfrDoublyLinkedList<ObjectSample> List;
  34  private:
  35   List _free_list;
  36   List _in_use_list;
  37   const ObjectSample* _last_resolved;
  38   mutable size_t _allocated;
  39   const size_t _limit;
  40   const size_t _cache_size;
  41 
  42   void populate_cache();
  43   ObjectSample* newSample() const;
  44   void link(ObjectSample* sample);
  45   void unlink(ObjectSample* sample);
  46   void deallocate_samples(List& list);
  47   void reset(ObjectSample* sample);
  48 
  49  public:
  50   SampleList(size_t limit, size_t cache_size = 0);
  51   ~SampleList();
  52 
  53   void set_last_resolved(const ObjectSample* sample);
  54   ObjectSample* get();
  55   ObjectSample* last() const;
  56   ObjectSample* first() const;
  57   void release(ObjectSample* sample);
  58   const ObjectSample* last_resolved() const;
  59   ObjectSample* reuse(ObjectSample* sample);
  60   bool is_full() const;
  61   size_t count() const;
  62 };
  63 
  64 #endif // SHARE_VM_JFR_LEAKPROFILER_SAMPLING_SAMPLELIST_HPP