Re: SwingWorker like interface in glib main loop?

[Chris Vine <chris cvine freeserve co uk>]

On Mon, 8 Sep 2008 23:16:44 +0200 (MEST)
"DANIELLLANO terra es" <DANIELLLANO terra es> wrote:

> I just saw Havoc's blog entry "SYNCHRONOUS IO NEVER OK":
> http://log.ometer.com/2008-09.html#7
> 
> and I wondered if there is a
> http://en.wikipedia.org/wiki/SwingWorker
> like interface in glib to run blocking code outside the glib main loop
> to prevent locking the gtk+ GUI?
> 
> Do you guys know an easy solution like SwingWorker for glib?

You can do non-blocking reads and writes with GIOChannel without having
to start any new threads and it is not much more difficult than
blocking reads - you set it non-blocking with g_io_channel_set_flags(),
plumb it into the main loop with g_io_add_watch() and read whatever
happens to be available in your callback function (until you get
G_IO_STATUS_AGAIN returned on the iochannel read), and keep on doing
that until you reach end of file or you have obtained whatever you were
expecting.  At that point you can remove the watch.

However, if you really need blocking reads (not very likely), you can
start a new thread to do the work - see:

http://library.gnome.org/devel/glib/stable/glib-Threads.html

You can hand any result back to the main GUI thread with g_idle_add()
(g_idle_add() is thread safe).

As it happens each thread can have their own main loop (that is, their
own GMainContext and GMainLoop objects), although it does
not sound as if you need to do that.

Chris