[Python-ideas] IDEA: do not alter default SIGINT handling

Giovanni Bajo rasky at develer.com
Thu Sep 17 10:15:41 CEST 2009

On Mon, 14 Sep 2009 10:23:14 +0900, Stephen J. Turnbull wrote:

> MRAB writes:
>  > How about 2 (or 3?) in rapid succession ("here's a CTRL-C, and here's
>  > another one to show I mean it!" :-)).
> That's more complexity than you want to put in a signal handler.  The
> way Emacs handles this is that the signal handler just enqueues a quit
> event, and the event loop checks for it and handles it.  In other places
> (such as looping functions) more complex QUIT processing (that checks
> for repeated signals and throws to the innermost QUIT catcher) is done,
> but this can only be done in "safe" places, not in the signal handler
> itself.  I imagine Python works the same way and it works fine in pure
> Python programs, too.

A cursory check over the signal handler shows the Python calls 
PyErr_SetNone(PyExc_KeyboardInterrupt) within the signal handler itself.

Handling a double-Ctrl-C would be very trivial, would solve the OP 
problem, and would not declare all existing C/C++ code in the world as 
"non-compatible-with-Python-ctrl-c-by-default", which is the current 
shame we live in.
Giovanni Bajo
Develer S.r.l.

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