user space program hangs

[Dan Peters <daniel.peters@gat.com>]

Hi,
I have a real time task running at 4 hz, which records some data and
sends it to the
user program for display.  The user program has a couple of pthreads,
and is also displaying images from a frame grabber
using Xlib.   I have found that if I try to make locally defined
function calls, the user space program randomly hangs exactly at
the call, and does not enter the function.  The real-time stuff keeps on

working fine.  I am forced to put everything inline to prevent
this.  Has anybody had this problem, and if so is there a fix?
 I am using the RTlinux v3.0 CD distribution.

thanks,
Dan Peters