Re: glibmm thread safety [was: Re: Adding custom GDK events]

[Daniel Elstner <daniel kitta googlemail com>]

Am Montag, den 15.01.2007, 12:14 +0000 schrieb Chris Vine:

> > Doomed, I'd say.  At least the call to remove_destroy_notify_callback()
> > after the GSource mutex has been unlocked is unavoidable with the
> > current API.  Maybe we'll be able to play some tricks and put something
> > entirely different into the sigc::connection object.  A special-purpose
> > slot which holds a connection ID or something, and goes through the
> > GMainLoop/GSource interface to destroy the callback slot.
[snip]
> Better still for this usage, perhaps there could be a 
> SignalIdle::single_connect() method which returns nothing and which will 
> disconnect the callback whatever it's return value once it has been executed 
> (in other words, it expects a void return value from the callback).

I like that idea.  It's useful beyond solving the threading problems as
well, as you no longer need to use sigc::bind_return(), or change the
code to return a boolean.  I'd prefer to call it connect_oneshot() or
connect_once(), though.  Murray?

In any case, the current plain connect() should of course be fixed too,
if at all possible.  But that'll be more difficult than introducing the
alternative API.

--Daniel