Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages

  
 
  

home | help
XtAppAddSignal(3)		 XT FUNCTIONS		     XtAppAddSignal(3)

NAME
       XtAppAddSignal, XtRemoveSignal, XtNoticeSignal -	register and remove a
       signal source

SYNTAX
       XtSignalId XtAppAddSignal(XtAppContext app_context, XtSignalCallback-
	      Proc proc, XtPointer client_data);

       void XtRemoveSignal(XtSignalId id);

       void XtNoticeSignal(XtSignalId id);

ARGUMENTS
       app_context
		 Specifies the application context.

       client_data
		 Specifies the argument	that is	to be passed to	the specified
		 procedure when	a signal has been raised.

       id	 Specifies the ID returned from	the corresponding XtAppAdd-
		 Signal	call.

       proc	 Specifies the procedure that is to be called when the signal
		 has been raised.

DESCRIPTION
       The XtAppAddSignal function initiates a mechanism for handling signals
       within the context of the Intrinsics. Prior to establishing an operat-
       ing system dependent signal handler the application may call XtAppAdd-
       Signal and store	the returned id	in a place accessible to the signal
       handler.

       Upon receipt of a signal	from the operating system, the application may
       call XtNoticeSignal passing the id returned by the call to XtAppAdd-
       Signal.

       XtNoticeSignal is the only Intrinsics function that can safely be
       called from a signal handler. If	XtNoticeSignal is called multiple
       times before the	Intrinsics are able to invoke the registered callback,
       the callback is only called once. Logically the Intrinsics maintain
       ``pending'' for each registered callback. This flag is initially	False
       and is set to True by XtNoticeSignal; the Intrinsics invoke the call-
       back whenever the flag is True, and the flag is set to False just be-
       fore the	callback is invoked.

       The XtRemoveSignal function is called to	remove the specified Intrin-
       sics signal handler. The	client should disable the source of the	signal
       before calling XtRemoveSignal.

SEE ALSO
       XtAppAddTimeOut(3),XtAppAddInput(3),XtAppAddWorkProc(3)
       X Toolkit Intrinsics - C	Language Interface
       Xlib - C	Language X Interface

X Version 11			  libXt	1.1.5		     XtAppAddSignal(3)

NAME | SYNTAX | ARGUMENTS | DESCRIPTION | SEE ALSO

Want to link to this manual page? Use this URL:
<https://www.freebsd.org/cgi/man.cgi?query=XtAppAddSignal&sektion=3&manpath=FreeBSD+12.1-RELEASE+and+Ports>

home | help