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From: frodek@forit.forut.no (Frode Kileng)
Newsgroups: comp.windows.x
Subject: SIGIO/SIGALRM in conflict with XLib ?
Summary: SIGIO & SIGALRM interrupts crashes XLib based application running on Openwindows 2
Keywords: Interrupts, Openwindows2, X Error BadRequest, X Error BadLength
Message-ID: <1991Apr18.162642.21502@mack.uit.no>
Date: 18 Apr 91 16:26:42 GMT
Sender: Frode Kileng
Organization: Norwegian Telecom Adm. Research Dep., Tromsoe, Norway
Lines: 46

Configuration:
	Sparc Station 1
	Openwindows 2
	Olwm.

I have a program for displaying X-ray images.  The program has been up running
for a couple of months at this time.  I'm now working with an audio expansion to
the program.

The audio part is set up to receive SIGIO interrupts when it is time to
read/write from/to the audio device.  The program also receives 
SIGALRM interrupts that I use to display the peek level of the audio and
to show record/play time.  At each SIGALRM interrupt I send 1-2 draw requests
to the X server.  The program run

Both the imaging part and the audio part work if I run them one at a time.
BUT it crash every time when I'm recording/playing and at the same time use
the imaging part.  The program crashes with the different X error messages :
  
  X Error BadRequest		X Error:  BadValue
    Request Major code 254 ()	  Request Major code 89 ()
    Request Minor code 254	  Request Minor code 0
    ResourceID 0xa00028		  ResourceID 0xa0002a
    Error Serial #285		  Error Serial #310
    Current Serial #312		  Current Serial #312

  X Error:  BadValue		X Error BadLength
    Request Major code 89 ()	  ..............
    Request Minor code 0	  ..............
    ResourceID 0xa0002a
    Error Serial #310
    Current Serial #312

Some times the program crash with no error messages at all.

My guess is that the program is doing a XLib call from the imaging part
and at the same time receives a SIGALRM interrupt
generating another XLib request before the first request is carried 
through.


I will appreciate any help on this problem.


Frode Kileng
Frode.Kileng@fbt.tf.tele.no	(frodek@forit.forut.no)