Path: utzoo!attcan!uunet!cs.utexas.edu!tut.cis.ohio-state.edu!snorkelwacker!bloom-beacon!TUVA.SAINET.MFENET!BLAKEC
From: BLAKEC@TUVA.SAINET.MFENET
Newsgroups: comp.windows.x
Subject: (none)
Message-ID: <891121123341.5280012c@CCC.NMFECC.GOV>
Date: 21 Nov 89 20:33:41 GMT
Sender: root@athena.mit.edu (Wizard A. Root)
Organization: The Internet
Lines: 27

Subject: Using signal() and kill() in X
Date:    Tue, 21-NOV-1989 13:41 MST
X-VMS-Mail-To: ARPA%"xpert@expo.lcs.mit.edu"

We are implementing a system where we have an X client which handles
all of the windowing characteristics of the application and another
process which transfers information to the X client and signals it
using XSendEvent.  Unfortunately, this causes the second process's
executable to be very large (about 224 kbytes) because it has to pull
in alot of Xlib routines to handle the XOpenDisplay and the XSendEvent.
We are operating on a Silicon Graphic Personal Iris running System V
UNIX and would like to use UNIX's kill and signal system calls to
signal the X client.

The question:  I heard that there might be a problem using the kill
to signal an X client because Xlib does not handle the case of
a UNIX system call returning because a signal occurred while the
system call was being executed.  Is this true?  And if it is, is
there a work around?  Also, under what circumstances would this
error occur (e.g. Can it occur while the X client is waiting on
an X event or does it only occur during the period of time when the
X client is dispatching an X event).

Any help would be greatly appreciated.

Carl D. Blake
SAIC, Tucson, AZ