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   void release(ObjectSample* sample);

    57   const ObjectSample* last_resolved() const;

    58   ObjectSample* reuse(ObjectSample* sample);

    59   bool is_full() const;

    60   size_t count() const;

    61 };

    62 

    63 #endif // SHARE_VM_JFR_LEAKPROFILER_SAMPLING_SAMPLELIST_HPP