On 9/5/06, Adam Olsen <[EMAIL PROTECTED]> wrote: > On 9/4/06, Gustavo Carneiro <[EMAIL PROTECTED]> wrote: > > Now, we've had this API for a long time already (at least 2.5 > > years). I'm pretty sure it works well enough on most *nix systems. > > Event if it works 99% of the times, it's way better than *failing* > > *100%* of the times, which is what happens now with Python. > > Failing 99% of the time is as bad as failing 100% of the time, if your > goal is to eliminate the short timeout on poll(). 1% is quite a lot, > and it would probably have an annoying tendency to trigger repeatedly > when the user does certain things (not reproducible by you of course). > > That said, I do hope we can get 100%, or at least enough nines that we > can increase the timeout significantly.
Anyway, I was speaking hypothetically. I'm pretty sure writing to a pipe is async signal safe. It is the oldest trick in the book, everyone uses it. I don't have to see a written signed contract to know that it works. Here's a list of web sites google found me that talk about this problem: This one describes the pipe writing technique: http://www.cocoadev.com/index.pl?SignalSafety This one presents a list of "The only routines that POSIX guarantees to be Async-Signal-Safe": http://docsun.cites.uiuc.edu/sun_docs/C/solaris_9/SUNWdev/MTP/p40.html#GEN-95948 Also here: http://www.cs.usyd.edu.au/cgi-bin/man.cgi?section=5&topic=attributes This is all the evidence that I need. And again I reiterate that whether or not async safety can be achieved in practice for all platforms is not Python's problem. Although I believe writing to a pipe is 100% reliable for most platforms. Even if it is not, any mission critical application relying on signals for correct behaviour should be rewritten to use unix sockets instead; end of argument. _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
