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   // how many generations are queued
  70   inline int generations_in_use() const {
  71     return (_tail >= _head ? (_tail - _head + 1) : (MAX_GENERATIONS - (_head - _tail) + 1));
  72   }
  73 };
  74 
  75 #endif // SHARE_VM_SERVICES_MEM_TRACK_WORKER_HPP