[Python-Dev] POSIX thread code

[Guido van Rossum]

[Tim]
> I'm deadly opposed to letting a keyboard interrupt break out of a
> wait for a Python lock.

I've heard this before.  Can you explain why?  It would not be
incorrect -- if the SIGINT had arrived a microsecond before the wait
started, the program would have been interrupted in exactly the same
state.  It's one of the few places where code can be blocked in a
system call (if you want to call a lock wait a system call -- it's
close enough for me) and a ^C doesn't stop it, and that can be
annoying at times.

Of course, if it's not the main thread, signals including SIGINT
shouldn't do anything, but that's a separate issue.  Breaking the main
thread IMO is useful behavior for interactive programs and for scripts
invoked from the command line.  (In practice, this is probably only
interesting for interactive use -- if you hang your main thread on a
deadlock, there's no way to get your >>> prompt back, and that may
mean no way to figure out what went wrong or save stuff you wanted to
save.

--Guido van Rossum (home page: http://www.python.org/~guido/)