Re: What causes GLib I/O Channels operations to use up 100% CPU in GTK+ app.?

[tomas tuxteam de]

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On Thu, Oct 12, 2006 at 02:41:06AM -0700, Daniel Yek wrote:
> Attaching file in email body...
>
> At 02:36 AM 10/12/2006, Daniel Yek wrote:
> > Hi,
> >
> > I am attaching the source code of a small test program here.
> >
> > Could somebody enlighten me why after an I/O Channel operation 
> > (g_io_channel_shutdown() here), the GTK+ program started to use up 100% CPU?
> >
> > Is it monitoring something? Do I need to undo g_io_add_watch() somehow? 
> > What operation is needed to not get into such situation?

I just browsed through your program (so take my rablings with a grain of
salt), but a couple of things strike me:

  - who is writing to the writing end of the pipe? Note that writing
    into and reading from the same pipe is not recommended (although for
    a small test program and if you are writing small amounts of data
    you might get away with iti ;-)

  - One thing which happens easily is: when the writing side closes, the
    reading side gets a read with 0 bytes (as a "signal" of EOF). In a
    select() (and that is what is at GTK's core dispatching things),
    this file descriptor is considered ready (but yielding zero bytes).
    I don't know whether GIOChannel wraps this (I doubt it can), but this
    is the typical cause for "spinning" in such programs.

Uh. I don't know if I was clear.

Regards
- -- tomÃÂs
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