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livetrax/libs/pbd/pbd/crossthread.h
Robin Gareus 959a37144b
Fix a few hundred doxygen warnings..
There are still over a hundred left, but this addresses many already.
In particular @param references to undocumented parameters.
Most notably in audio_backend.h
2019-09-30 04:45:59 +02:00

109 lines
3.3 KiB
C++

/*
* 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.
*/
#ifndef __pbd__crossthread_h__
#define __pbd__crossthread_h__
#ifdef check
#undef check
#endif
#include <glibmm/main.h>
#include "pbd/libpbd_visibility.h"
#ifdef PLATFORM_WINDOWS
#include <windows.h>
#endif // PLATFORM_WINDOWS
/** A simple abstraction of a mechanism of signalling one thread from another.
* The signaller calls \ref wakeup() to tell the signalled thread to check for
* work to be done.
*
* This implementation provides both selectable() for use in direct
* poll/select-based event loops, and a Glib::IOSource via ios() for use
* in Glib main loop based situations.
*/
class LIBPBD_API CrossThreadChannel {
public:
/** if @a non_blocking is true, the channel will not cause blocking
* when used in an event loop based on poll/select or the glib main
* loop.
*/
CrossThreadChannel(bool non_blocking);
~CrossThreadChannel();
/** Tell the listening thread that is has work to do.
*/
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);
/** if using \ref deliver() to wakeup the listening thread, then
* the listener should call \ref receive() to fetch the message
* type from the channel.
*
* wait = true only make sense for non_blocking channels,
* it polls for data to become available.
*/
int receive (char& msg, bool wait = false);
/** empty the channel of all requests.
* Typically this is done as soon as input
* is noticed on the channel, because the
* handler will look at a separately managed work
* queue. The actual number of queued "wakeups"
* in the channel will not be important.
*/
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
};
#endif /* __pbd__crossthread_h__ */