[Glade-users] GTK+ threads: works great but compile-time warning

[pdbuchan at yahoo.com (David Buchan)]

Sorry to mail-bomb everyone, but I should clarify why I lose control in this case. The computation is like 
calculating pi to infinite digits. It keeps going forever (while (onoff == 1) statement). My hope was to have 
the user toggle onoff between 0 and 1 by button click.

--- On Sun, 5/29/11, David Buchan <pdbuchan at yahoo.com> wrote:

> From: David Buchan <pdbuchan at yahoo.com>
> Subject: Re: [Glade-users] GTK+ threads: works great but compile-time warning
> To: glade-users at lists.ximian.com
> Date: Sunday, May 29, 2011, 7:17 PM
> I found some people on the web who
> were putting a cast (GThreadFunc) before the 1st argument of
> g_thread_create. I did this, and got rid of the error
> message. Weird, and a little worrisome. Regardless, the code
> works.
>
> But it occurs to me that maybe I don't need to do threads
> at all.
> Here's specifically what I want to achieve:
>
> I have the user press a button to begin some heavy
> computation, but I also want the user to be able to press
> another button, if desired, to stop the computation. They
> won't need to do anything else. That is, other than stop the
> computation, they need no more functionality while the
> numbers are being crunched.
>
> I had tested briefly and found that once the computation
> started, I lost control and had to click on the x to close
> out the window. In Ubuntu, the screen darkens to inform the
> user that they've lost control. This is what initially led
> me to believe I needed threads.
>
> Is there a way to allow them to stop the computation
> without resorting to threads? Seems like something a lot of
> programs would need, and I (perhaps mistakely) didn't think
> threads were quite so commonly used.
>
> Dave
>
> --- On Sat, 5/28/11, David Buchan <pdbuchan at yahoo.com>
> wrote:
>
> > From: David Buchan <pdbuchan at yahoo.com>
> > Subject: GTK+ threads: works great but compile-time
> warning
> > To: glade-users at lists.ximian.com
> > Date: Saturday, May 28, 2011, 8:58 PM
> > Hi guys,
> >
> > Info: Ubuntu (lucid), gtkbuilder from glade 3.6.7, C
> > language with gcc.
> >
> > I took some of Tadej's thread code from his Bits and
> Pieces
> > blog post, and modified it to closer to what I need.
> >
> > Specifically, I moved the thread creation into a
> callback,
> > on the basis that I understood that all callbacks
> were
> > inside main's threadlock so it should be equivalent.
> I
> > removed the timeout.
> >
> > You click on button1 and it's label will cycle from
> > "thread" to "cycle" each second. You click on button2
> to
> > stop it.
> >
> > It does the job, but gives a compile-time warning:
> >
> > test5.c: In function ?on_button1_clicked?:
> > test5.c:33: warning: passing argument 1 of
> > ?g_thread_create_full? from incompatible pointer
> type
> > /usr/include/glib-2.0/glib/gthread.h:225: note:
> expected
> > ?GThreadFunc? but argument is of type ?void *
> > (*)(struct TestData *)?
> >
> > Note that I call g_thread_create not
> g_thread_create_full.
> > Comments?
> > Code attached.
> >
> > Thanks,
> > Dave
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