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From: jeff@samna.UUCP (jeff)
Newsgroups: comp.windows.x
Subject: Re: Problem with Signals
Message-ID: <203@samna.UUCP>
Date: 7 Mar 90 23:33:58 GMT
References: <9002281729.AA02895@wilkins.bcm.tmc.edu> <132399@sun.Eng.Sun.COM> <23695@masscomp.ccur.com>
Reply-To: jeff@samna.UUCP (Jeff Barber)
Organization: Samna Corporation, Atlanta
Lines: 38

In article <23695@masscomp.ccur.com> mitch@westford.ccur.com (Mitchel Kuninsky) writes:
:I envision a signal handler like:
:
:	SignalHandler
:	{
:	    sigFlag = TRUE;
:	}
:
:and an XtMainLoop like:
:
:	MyMainLoop()
:	{
:	    XEvent event;
:
:	    for (;;)
:	    {
:(1)		XtNextEvent( &event );
:		if (event.type != NULL_EVENT)	/* or something like this. */
:		    XtDispatchEvent( &event );
:		if (sigFlag)
:		{
:		    process signal.
:		    Inhibit signals.
:		    sigFlag = FALSE;
:(2)		    Enable signals.
:		}
:	    }
:	}

This may be kind of nit-picking, but ... You have a nasty race here.
What if a signal arrives between the re-enabling of signals at (2) and
the next call to XtNextEvent at (1).

I believe this points out the need to have the signal-handling more
tightly integrated with the Intrinsics code.

---
Jeff