crossthread.h

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/*
 * Copyright (C) 2006-2015 Paul Davis <paul@linuxaudiosystems.com>
 * Copyright (C) 2015 Robin Gareus <robin@gareus.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
 
#pragma once
 
#ifdef check
#undef check
#endif
 
#include <glibmm/main.h>
 
#include "pbd/libpbd_visibility.h"
 
#ifdef PLATFORM_WINDOWS
#include <windows.h>
#endif // PLATFORM_WINDOWS
 
 
class LIBPBD_API CrossThreadChannel {
public:
        CrossThreadChannel(bool non_blocking);
        ~CrossThreadChannel();
 
        void wakeup();
 
        /* if the listening thread cares about the precise message
         * it is being sent, then \ref deliver() can be used to send
         * a single byte message rather than a simple wakeup. These
         * two mechanisms should not be used on the same CrossThreadChannel
         * because there is no way to know which byte value will be used
         * for ::wakeup()
         */
        int deliver (char msg);
 
        int receive (char& msg, bool wait = false);
 
        void drain ();
 
        void set_receive_handler (sigc::slot<bool,Glib::IOCondition> s);
        void attach (Glib::RefPtr<Glib::MainContext>);
 
private:
        friend gboolean cross_thread_channel_call_receive_slot (GIOChannel*, GIOCondition condition, void *data);
 
        GIOChannel* receive_channel;
        GSource*    receive_source;
        sigc::slot<bool,Glib::IOCondition> receive_slot;
 
        bool poll_for_request();
 
#ifndef PLATFORM_WINDOWS
        int fds[2]; // current implementation uses a pipe/fifo
#else
 
        SOCKET send_socket;
        SOCKET receive_socket;
        struct sockaddr_in recv_address;
#endif
 
};