https://invisible-island.net/xterm/xtoolkit/
XtSessionGetToken, XtSessionReturnToken - token management for check- pointing
#include <X11/Intrinsic.h> XtCheckpointToken XtSessionGetToken(Widget w); void XtSessionReturnToken(XtCheckpointToken token);
w Specifies the session widget. token Specifies the token to be returned.
The XtSessionGetToken function will return NULL if the checkpoint oper- ation instigated by the session manager is not currently under way. To indicate the completion of a deferred save operation and to return the checkpoint token use XtSessionReturnToken.
X Toolkit Intrinsics – C Language Interface Xlib - C Language X Interface X Version 11 libXt 1.1.5.2 XtSessionGetToken(3)