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 class GenerationData : public _ValueObj {
  36  private:
  37   int           _number_of_classes;
  38   MemRecorder*  _recorder_list;
  39 
  40  public:
  41   GenerationData(): _number_of_classes(0), _recorder_list(NULL) { }
  42 
  43   inline int  number_of_classes() const { return _number_of_classes; }
  44   inline void set_number_of_classes(long num) { _number_of_classes = num; }
  45 
  46   inline MemRecorder* next_recorder() {
  47     if (_recorder_list == NULL) {
  48       return NULL;
  49     } else {
  50       MemRecorder* tmp = _recorder_list;
  51       _recorder_list = _recorder_list->next();
  52       return tmp;
  53     }
  54   }
  55 
  56   inline bool has_more_recorder() const {
  57     return (_recorder_list != NULL);
  58   }
  59 
  60   // add recorders to this generation
  61   void add_recorders(MemRecorder* head) {
  62     if (head != NULL) {
  63       if (_recorder_list == NULL) {
  64         _recorder_list = head;
  65       } else {
  66         MemRecorder* tmp = _recorder_list;
  67         for (; tmp->next() != NULL; tmp = tmp->next());
  68         tmp->set_next(head);
  69       }
  70     }
  71   }
  72 
  73   void reset();
  74 
  75   NOT_PRODUCT(MemRecorder* peek() const { return _recorder_list; })
  76 };
  77 
  78 class MemTrackWorker : public NamedThread {
  79  private:
  80   // circular buffer. This buffer contains generation data to be merged into global
  81   // snaphsot.
  82   // Each slot holds a generation
  83   GenerationData  _gen[MAX_GENERATIONS];
  84   int             _head, _tail; // head and tail pointers to above circular buffer
  85 
  86   bool            _has_error;
  87 
  88  public:
  89   MemTrackWorker();
  90   ~MemTrackWorker();
  91   _NOINLINE_ void* operator new(size_t size);
  92   _NOINLINE_ void* operator new(size_t size, const std::nothrow_t& nothrow_constant);
  93 
  94   void start();
  95   void run();
  96 
  97   inline bool has_error() const { return _has_error; }
  98 
  99   // task at synchronization point
 100   void at_sync_point(MemRecorder* pending_recorders, int number_of_classes);
 101 
 102   // for debugging purpose, they are not thread safe.
 103   NOT_PRODUCT(static int count_recorder(const MemRecorder* head);)
 104   NOT_PRODUCT(int count_pending_recorders() const;)
 105 
 106   NOT_PRODUCT(int _sync_point_count;)
 107   NOT_PRODUCT(int _merge_count;)
 108   NOT_PRODUCT(int _last_gen_in_use;)
 109 
 110   // how many generations are queued
 111   inline int generations_in_use() const {
 112     return (_tail >= _head ? (_tail - _head + 1) : (MAX_GENERATIONS - (_head - _tail) + 1));
 113   }
 114 };
 115 
 116 #endif // SHARE_VM_SERVICES_MEM_TRACK_WORKER_HPP