1 /*

     2  * Copyright (c) 2012, 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_SERVICES_MEM_TRACK_WORKER_HPP

    26 #define SHARE_VM_SERVICES_MEM_TRACK_WORKER_HPP

    27 

    28 #include "memory/allocation.hpp"

    29 #include "runtime/thread.hpp"

    30 #include "services/memRecorder.hpp"

    31 

    32 // Maximum MAX_GENERATIONS generation data can be tracked.

    33 #define MAX_GENERATIONS  512

    34 

    35 

    36 class MemTrackWorker : public NamedThread {

    37  private:

    38   // circular buffer. This buffer contains recorders to be merged into global

    39   // snaphsot.

    40   // Each slot holds a linked list of memory recorders, that contains one

    41   // generation of memory data.

    42   MemRecorder*  _gen[MAX_GENERATIONS];

    43   int           _head, _tail; // head and tail pointers to above circular buffer

    44 

    45   bool          _has_error;

    46 

    47  public:

    48   MemTrackWorker();

    49   ~MemTrackWorker();

    50   _NOINLINE_ void* operator new(size_t size);

    51   _NOINLINE_ void* operator new(size_t size, const std::nothrow_t& nothrow_constant);

    52 

    53   void start();

    54   void run();

    55 

    56   inline bool has_error() const { return _has_error; }

    57 

    58   // task at synchronization point

    59   void at_sync_point(MemRecorder* pending_recorders);

    60 

    61   // for debugging purpose, they are not thread safe.

    62   NOT_PRODUCT(static int count_recorder(const MemRecorder* head);)

    63   NOT_PRODUCT(int count_pending_recorders() const;)

    64 

    65   NOT_PRODUCT(int _sync_point_count;)

    66   NOT_PRODUCT(int _merge_count;)

    67   NOT_PRODUCT(int _last_gen_in_use;)

    68 

    69   inline int generations_in_use() const {

    70     return (_tail <= _head ? (_head - _tail + 1) : (MAX_GENERATIONS - (_tail - _head) + 1));

    71   }

    72 };

    73 

    74 #endif // SHARE_VM_SERVICES_MEM_TRACK_WORKER_HPP