/*
    Copyright (c) 2009-2012 250bpm s.r.o.
    Copyright (c) 2007-2009 iMatix Corporation
    Copyright (c) 2007-2011 Other contributors as noted in the AUTHORS file

    This file is part of Crossroads I/O project.

    Crossroads I/O is free software; you can redistribute it and/or modify it
    under the terms of the GNU Lesser General Public License as published by
    the Free Software Foundation; either version 3 of the License, or
    (at your option) any later version.

    Crossroads 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 Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#ifndef __XS_I_ENGINE_HPP_INCLUDED__
#define __XS_I_ENGINE_HPP_INCLUDED__

namespace xs
{

    class io_thread_t;

    //  Abstract interface to be implemented by various engines.

    struct i_engine
    {
        virtual ~i_engine () {}

        //  Plug the engine to the session.
        virtual void plug (xs::io_thread_t *io_thread_,
            class session_base_t *session_) = 0;

        //  Unplug the engine from the session.
        virtual void unplug () = 0;

        //  Terminate and deallocate the engine. Note that 'detached'
        //  events are not fired on termination.
        virtual void terminate () = 0;

        //  This method is called by the session to signalise that more
        //  messages can be written to the pipe.
        virtual void activate_in () = 0;

        //  This method is called by the session to signalise that there
        //  are messages to send available.
        virtual void activate_out () = 0;
    };

}

#endif
