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XtAppAddSignal(3Xt)
X11R6
NAME
  XtAppAddSignal, XtRemoveSignal, XtNoticeSignal - register and remove a
  signal source

SYNOPSIS
  XtSignalId XtAppAddSignal(app_context, proc, client_data)
	  XtAppContext app_context;
	  XtSignalCallbackProc proc;
	  XtPointer client_data;

  void XtRemoveSignal(id)
	  XtSignalIdid;

  void XtNoticeSignal(id)
	  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 XtAppAddSignal 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 operating
  system dependent signal handler the application may call XtAppAddSignal 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 XtAppAddSignal.

  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 callback whenever the flag is
  True, and the flag is set to False just before the callback is invoked.

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

SEE ALSO
  XtAppAddTimeOut(3Xt), XtAppAddInput(3Xt), XtAppAddWorkProc(3Xt),

  X Toolkit Intrinsics -- C Language Interface

  Xlib -- C Language X Interface

Index for Section 3Xt

Alphabetical listing for X

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