Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!wuarchive!texbell!texsun!newstop!sun!kimba!hvr
From: hvr@kimba.Sun.COM (Heather Rose)
Newsgroups: comp.windows.x
Subject: Re: X & signals
Keywords: xwindows signals
Message-ID: <132610@sun.Eng.Sun.COM>
Date: 7 Mar 90 03:40:44 GMT
References: <1154@sdrc.UUCP>
Sender: news@sun.Eng.Sun.COM
Reply-To: hvr@sun.UUCP (Heather Rose)
Organization: Sun Microsystems, Mountain View
Lines: 34

In article <1154@sdrc.UUCP> evgabb@sdrc.UUCP (Rob Gabbard) writes:
>Has anyone had any problems with using alarm signals with X ? My problem is
>this - I have an X application that may be away from the event loop for 
>quite some time.  So, to avoid overflowing the event queue, I have a routine
>that looks somthing like this:
>
>	clean_queue()
>	{
>		while ( XPending( display ) )
>			{
>			XtNextEvent( &event );
>			XtDispatchEvent( &event );
>			}
>
>		signal(SIGALRM,clean_queue);
>	}
>
>	Upon exiting my event loop to go and do something else I call 
>signal(SIGALRM,clean_queue) and then use setitimer to send an alarm every
>few seconds. Then, when reentering my event loop I turn the timer back off.
>
>	This works fine for a while but it eventually crashes. The error
>messages range from invalid protocol requests to bad op codes in 
>XDeleteProperty.  This is running under Ultrix on a DECStation 3100.

The XView toolkit provides an interface for signals (including alarms).
If you are not using XView, you might want to take a peek at the implementation
of the notifier library.  XView source is included in the X11R4 distribution.

The applicable code would be in <contrib>/toolkits/XView/lib/libxvin/notify

Regards,

Heather