CrossThreadChannel Class Reference

#include <crossthread.h>

Public Member Functions
	CrossThreadChannel (bool non_blocking)
	~CrossThreadChannel ()
void	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 Member Functions
bool	poll_for_request ()

Private Attributes
GIOChannel *	receive_channel
GSource *	receive_source
sigc::slot< bool, Glib::IOCondition >	receive_slot
int	fds [2]

Friends
gboolean	cross_thread_channel_call_receive_slot (GIOChannel *, GIOCondition condition, void *data)

Detailed Description

A simple abstraction of a mechanism of signalling one thread from another. The signaller calls ::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.

Definition at line 45 of file crossthread.h.

Constructor & Destructor Documentation

CrossThreadChannel::CrossThreadChannel

(

bool

non_blocking

)

if 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.

Definition at line 3 of file crossthread.posix.cc.

CrossThreadChannel::~CrossThreadChannel

(

)

Definition at line 29 of file crossthread.posix.cc.

Member Function Documentation

void CrossThreadChannel::attach

(

Glib::RefPtr< Glib::MainContext >

context

)

Definition at line 59 of file crossthread.cc.

int CrossThreadChannel::deliver

(

char

msg

)

Definition at line 61 of file crossthread.posix.cc.

void CrossThreadChannel::drain

(

)

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.

Definition at line 54 of file crossthread.posix.cc.

bool CrossThreadChannel::poll_for_request ( )

private

Definition at line 67 of file crossthread.posix.cc.

int CrossThreadChannel::receive	(	char &	msg,
		bool	wait = false
	)

if using ::deliver() to wakeup the listening thread, then the listener should call ::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.

Definition at line 91 of file crossthread.posix.cc.

void CrossThreadChannel::set_receive_handler

(

sigc::slot< bool, Glib::IOCondition >

s

)

Definition at line 53 of file crossthread.cc.

void CrossThreadChannel::wakeup

(

)

Tell the listening thread that is has work to do.

Definition at line 47 of file crossthread.posix.cc.

Friends And Related Function Documentation

gboolean cross_thread_channel_call_receive_slot ( GIOChannel *  , GIOCondition  condition, void *  data  )

friend

Definition at line 46 of file crossthread.cc.

Member Data Documentation

int CrossThreadChannel::fds[2]

private

Definition at line 98 of file crossthread.h.

GIOChannel* CrossThreadChannel::receive_channel

private

Definition at line 91 of file crossthread.h.

sigc::slot<bool,Glib::IOCondition> CrossThreadChannel::receive_slot

private

Definition at line 93 of file crossthread.h.

GSource* CrossThreadChannel::receive_source

private

Definition at line 92 of file crossthread.h.

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The documentation for this class was generated from the following files:

• /usr/local/music/src/ardour/4.0/libs/pbd/pbd/crossthread.h
• /usr/local/music/src/ardour/4.0/libs/pbd/crossthread.cc
• /usr/local/music/src/ardour/4.0/libs/pbd/crossthread.posix.cc
• /usr/local/music/src/ardour/4.0/libs/pbd/crossthread.win.cc