XtAppLock, XtAppUnlock - lock and unlock application context
#include <X11/Intrinsic.h>
void XtAppLock(XtAppContext app_context);
void XtAppUnlock(XtAppContext app_context);
Specifies the application context.
XtAppLock locks the application context including all its related displays and widgets.
XtAppUnlock unlocks the application context.
X Toolkit Intrinsics - C Language Interface
Xlib - C Language X Interface