atomic_list.h

/***************************************************************************
        Copyright (C) 2002-2015 Kentaro Kitagawa
                           kitagawa@phys.s.u-tokyo.ac.jp

        This program is free software; you can redistribute it and/or
        modify it under the terms of the GNU Library General Public
        License as published by the Free Software Foundation; either
        version 2 of the License, or (at your option) any later version.

        You should have received a copy of the GNU Library General
        Public License and a list of authors along with this program;
        see the files COPYING and AUTHORS.
***************************************************************************/
#ifndef ATOMIC_LIST_H_
#define ATOMIC_LIST_H_

#include "atomic_smart_ptr.h"
#include <deque>

template <typename T, class LIST = std::deque<T> >
class atomic_list : public atomic_shared_ptr<LIST> {
public:
    typedef typename LIST::iterator iterator;
    typedef typename LIST::const_iterator const_iterator;
    typedef local_shared_ptr<const LIST> reader;

    atomic_list() {}
    ~atomic_list() {}

    class writer : public local_shared_ptr<LIST> {
    public:
        writer(atomic_list &x) :
            local_shared_ptr<LIST>(),
            m_target(x),
            m_old_var(x) {
            reset_unsafe(m_old_var ? (new LIST(*m_old_var)) : (new LIST()));
        }
        ~writer() {}
        bool commit() {
            return (m_target.compareAndSet(m_old_var, *this));
        }
    protected:
        writer();
    private:
        atomic_list &m_target;
        const local_shared_ptr<LIST> m_old_var;
    };

    void push_back(const T &x) {
        for(;;) {
            auto tr(*this);
            tr->push_back(x);
            if(tr.commit())
                break;
        }
    }
};

#endif /* ATOMIC_LIST_H_ */