libcruft-util/cruft/util/thread/monitor.hpp

/*
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * Copyright 2018 Danny Robson <danny@nerdcruft.net>
 */

#pragma once

#include <functional>
#include <mutex>
#include <utility>


namespace cruft::thread {
    template <typename ValueT, typename MutexT = std::mutex>
    class monitor {
    public:
        template <typename ...Args>
        monitor (Args &&...args):
            m_value (::std::forward<Args> (args)...)
        { ; }

        class proxy {
        public:
            proxy (MutexT &_mutex, ValueT &_value):
                m_guard (_mutex),
                m_value (_value)
            { ; }

            ValueT* operator-> ()
            {
                return &m_value;
            }

        private:
            ::std::lock_guard<MutexT> m_guard;
            ValueT &m_value;
        };

        auto acquire (void) { return proxy (m_mutex, m_value); }
        auto operator-> () { return acquire (); }

    private:
        MutexT m_mutex;
        ValueT m_value;
    };
};