Hopefully, this page is exactly what you are looking for, but if not, you can always find further assistance on Unix/Linux Forum!
XtToolkitThreadInitialize(3) XT FUNCTIONS XtToolkitThreadInitialize(3)
NAME
XtToolkitThreadInitialize - initialize the toolkit for multiple threads
SYNTAX
Boolean XtToolkitThreadInitialize(void);
DESCRIPTION
If XtToolkitThreadInitialize was previously called, it returns. The
application programmer must ensure that two or more threads do not
simultaneously attempt to call XtToolkitThreadInitialize; the effect of
this is undefined. XtToolkitThreadInitialize returns True if the host
operating system has threads and the Intrinsics are thread safe.
SEE ALSO
X Toolkit Intrinsics - C Language Interface
Xlib - C Language X Interface
X Version 11 libXt 1.0.4 XtToolkitThreadInitialize(3)