Force immediate back-end window creation
#include <X11/extensions/dmxext.h>
Bool DMXForceWindowCreation(Display *dpy, Window window);
When using the lazy window creation optimization, windows are not created on the back-end X servers until they are required. DMXForceWindowCreation() forces the immediate creation of the window requested.
DMXForceWindowCreation() returns True unless there is a protocol error. DMXForceWindowCreation() can generate BadWindow errors.