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Java example source code file (memTrackWorker.hpp)

This example Java source code file (memTrackWorker.hpp) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

generationdata, max_generations, memrecorder, memsnapshot, memtrackworker, namedthread, not_product, null, share_vm_services_mem_track_worker_hpp, value_obj_class_spec

The memTrackWorker.hpp Java example source code

/*
 * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 *
 */

#ifndef SHARE_VM_SERVICES_MEM_TRACK_WORKER_HPP
#define SHARE_VM_SERVICES_MEM_TRACK_WORKER_HPP

#include "memory/allocation.hpp"
#include "runtime/thread.hpp"
#include "services/memRecorder.hpp"

// Maximum MAX_GENERATIONS generation data can be tracked.
#define MAX_GENERATIONS  512

class GenerationData VALUE_OBJ_CLASS_SPEC {
 private:
  int           _number_of_classes;
  MemRecorder*  _recorder_list;

 public:
  GenerationData(): _number_of_classes(0), _recorder_list(NULL) { }

  inline int  number_of_classes() const { return _number_of_classes; }
  inline void set_number_of_classes(long num) { _number_of_classes = num; }

  inline MemRecorder* next_recorder() {
    if (_recorder_list == NULL) {
      return NULL;
    } else {
      MemRecorder* tmp = _recorder_list;
      _recorder_list = _recorder_list->next();
      return tmp;
    }
  }

  inline bool has_more_recorder() const {
    return (_recorder_list != NULL);
  }

  // add recorders to this generation
  void add_recorders(MemRecorder* head) {
    if (head != NULL) {
      if (_recorder_list == NULL) {
        _recorder_list = head;
      } else {
        MemRecorder* tmp = _recorder_list;
        for (; tmp->next() != NULL; tmp = tmp->next());
        tmp->set_next(head);
      }
    }
  }

  void reset();

  NOT_PRODUCT(MemRecorder* peek() const { return _recorder_list; })
};

class MemTrackWorker : public NamedThread {
 private:
  // circular buffer. This buffer contains generation data to be merged into global
  // snaphsot.
  // Each slot holds a generation
  GenerationData  _gen[MAX_GENERATIONS];
  int             _head, _tail; // head and tail pointers to above circular buffer

  bool            _has_error;

  MemSnapshot*    _snapshot;

 public:
  MemTrackWorker(MemSnapshot* snapshot);
  ~MemTrackWorker();
  _NOINLINE_ void* operator new(size_t size) throw();
  _NOINLINE_ void* operator new(size_t size, const std::nothrow_t& nothrow_constant) throw();

  void start();
  void run();

  inline bool has_error() const { return _has_error; }

  // task at synchronization point
  void at_sync_point(MemRecorder* pending_recorders, int number_of_classes);

  // for debugging purpose, they are not thread safe.
  NOT_PRODUCT(static int count_recorder(const MemRecorder* head);)
  NOT_PRODUCT(int count_pending_recorders() const;)

  NOT_PRODUCT(int _sync_point_count;)
  NOT_PRODUCT(int _merge_count;)
  NOT_PRODUCT(int _last_gen_in_use;)

  // how many generations are queued
  inline int generations_in_use() const {
    return (_tail >= _head ? (_tail - _head + 1) : (MAX_GENERATIONS - (_head - _tail) + 1));
  }
};

#endif // SHARE_VM_SERVICES_MEM_TRACK_WORKER_HPP

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