[Python-Dev] Where to put the interrupt module?

[Kevin Jacobs]

On Thu, 12 Jun 2003, Guido van Rossum wrote:
> The interrupt module currently uses PyErr_SetInterrupt(), which can
> only raise KeyboardInterrupt.
> 
> Let's not generalize this until there's a need.  Then, let whoever has
> the need add the generalization.

In that past, there have been a few times where it would have been very
convenient to terminate/signal another thread by posting an exception to it.
Using KeyboardInterrupt to do so is okay, although it seems like something
of a kludge.

> I'm actually a bit wary of such a generalization, because
> KeyboardInterrupt is currently the only *asynchronous* exception that
> code needs to worry about.  There is plenty of code that gives
> KeyboardInterrupt special treatment, [..]

Code that gives special status to KeyboardInterrupt doesn't worry me at all. 
What I am wary of is code that is not written to be exception safe in the
presence of unexpected exceptions (not just asynchronous ones).  The example
I was working on yesterday involved KeyboardInterrupts generated from an SSL
socket in httplib's SSL readline method.  A keyboard interrupt will result
in data read from the socket and then stored in a local variable to be lost. 
Of course, this error wasn't very likely before I patched the SSL module to
check for interrupts, but that is beside the point.

-Kevin

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Kevin Jacobs
The OPAL Group - Enterprise Systems Architect
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