XtAppAddBlockHook, XtRemoveBlockHook - register a block hook procedure

app_context
                 Specifies the application context.

       proc      Specifies the block hook procedure.

       num_args  Specifies the application-specific data to be passed to the block hook.

XtAppAddBlockHook registers the specified procedure and returns an identifier for it.  The hook is called
       at any time in the future when the Intrinsics are about to block pending some input.

       Block  hook  procedures are removed automatically and the XtBlockHookId is destroyed when the application
       context in which they were added is destroyed.

       XtRemoveBlockHook removes the specified block hook procedure from the list in which it was registered.

       XtAppAddBlockHook, XtRemoveBlockHook - register a block hook procedure

XToolkitIntrinsics-CLanguageInterfaceXlib-CLanguageXInterface

X Version 11                                       libXt 1.2.1                              XtAppAddBlockHook(3)

       #include <X11/Intrinsic.h>

       XtBlockHookId XtAppAddBlockHook(XtAppContext app_context, XtBlockHookProc proc, XtPointer client_data);

       void XtRemoveBlockHook(XtBlockHookId id);