src/utility/shared_resource.h

   1 /***************************************************************************
   2  *   Copyright (C) 2008-2016 by Andrzej Rybczak                            *
   3  *   electricityispower@gmail.com                                          *
   4  *                                                                         *
   5  *   This program is free software; you can redistribute it and/or modify  *
   6  *   it under the terms of the GNU General Public License as published by  *
   7  *   the Free Software Foundation; either version 2 of the License, or     *
   8  *   (at your option) any later version.                                   *
   9  *                                                                         *
  10  *   This program is distributed in the hope that it will be useful,       *
  11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  13  *   GNU General Public License for more details.                          *
  14  *                                                                         *
  15  *   You should have received a copy of the GNU General Public License     *
  16  *   along with this program; if not, write to the                         *
  17  *   Free Software Foundation, Inc.,                                       *
  18  *   51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.              *
  19  ***************************************************************************/
  20
  21 #ifndef NCMPCPP_UTILITY_SHARED_RESOURCE_H
  22 #define NCMPCPP_UTILITY_SHARED_RESOURCE_H
  23
  24 #include <mutex>
  25
  26 template <typename ResourceT>
  27 struct Shared
  28 {
  29         struct Resource
  30         {
  31                 Resource(std::mutex &mutex, ResourceT &resource)
  32                         : m_lock(std::unique_lock<std::mutex>(mutex)), m_resource(resource)
  33                 { }
  34
  35                 ResourceT &operator*() { return m_resource; }
  36                 const ResourceT &operator*() const { return m_resource; }
  37
  38                 ResourceT *operator->() { return &m_resource; }
  39                 const ResourceT *operator->() const { return &m_resource; }
  40
  41         private:
  42                 std::unique_lock<std::mutex> m_lock;
  43                 ResourceT &m_resource;
  44         };
  45
  46         Shared(){ }
  47
  48         template <typename ValueT>
  49         Shared(ValueT &&value)
  50                 : m_resource(std::forward<ValueT>(value))
  51         { }
  52
  53         Resource acquire() { return Resource(m_mutex, m_resource); }
  54
  55 private:
  56         std::mutex m_mutex;
  57         ResourceT m_resource;
  58 };
  59
  60 #endif // NCMPCPP_UTILITY_SHARED_RESOURCE_H