Path: utzoo!attcan!uunet!husc6!bloom-beacon!ATHENA.MIT.EDU!swick
From: swick@ATHENA.MIT.EDU (Ralph R. Swick)
Newsgroups: comp.windows.x
Subject: Re: Determining validity/type of unknown XIDs - how ??
Message-ID: <8808111340.AA01871@LYRE.MIT.EDU>
Date: 11 Aug 88 13:40:20 GMT
References: <110@tityus.UUCP>
Sender: daemon@bloom-beacon.MIT.EDU
Organization: DEC/MIT Project Athena
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     Date:  11 Aug 88 01:17:03 GMT
     From:  vsi1!daver!athsys!jim@AMES.ARC.NASA.GOV  (Jim Becker)

                       a window ID that has been created but has
     not yet "stablized" for X calls.

If your library is correctly written, I don't understand how this
occurs unless you have separate processes (or display connections)
and are passing ids between them outside of X.

                                        I can safely ignore the service
     request, if I can recognize that the XID is not yet useful. Is there
     a call that will return information about a random XID to me ??

No; you're supposed to remember what it was you asked for.
                                                                       If
     I use it in a normal X call it causes the server to not understand 
     the XID (although it really should), resulting in an X handler trap.

Why should/doesn't it?  If the creation occurs on the same display
connection as the reference, things are supposed to work.  If you're
using multiple display connections, you'll have to invent some way to
synchronize between them.  Often PropertyNotify events are useful
to accomplish this.