frose@synoptics.com (Flavio Rose) (11/09/90)
Followup-To: Distribution: world Organization: SynOptics Communications Inc. Santa Clara, Ca. Disclaimer: Sender is *solely* responsible for the contents of message Keywords: Can a program based on the X Toolkit Intrinsics reliably perform a graphic operation (e.g. XtManageChild) in response to the receipt of a UNIX signal? It is my understanding that it is not safe to directly call things like XtManageChild inside a UNIX signal handler. Right? So the handler has to set a flag which is interpreted by some other piece of code that actually does the graphics. Unfortunately I can't figure out how to arrange for this other piece of code to be called. The best approximation I can come up with is to have this code called every so often via XtAppAddTimeout. Without timeouts, I can't see any way to wake up XtAppNextEvent from its slumber when the signal occurs. (I've looked at the code in src/mit/lib/Xt/NextEvent.c from X11R4... as best I can tell, if EINTR wakes it up and no timeout has expired, it goes right back to sleep by calling select once again.) In XView terms, what I am looking for is an equivalent to notify_set_signal_func with NOTIFY_SYNC. Any advice would be most appreciated. The target OS is SunOS, but we want to remain portable to other UNIX versions. Flavio Rose SynOptics Communications, Inc. frose@synoptics.com