Summary: Is there a select()-like call for message queues?

Peter da Silva peter at ficc.uu.net
Tue Jan 16 05:07:04 AEST 1990


> -Let's add 4 new system calls: aread, awrite, await, and status.
> -This doesn't break any existing programs, nor does it do any injury to
> -the design goals of UNIX.

> Yes, it does!  Go back and read what I said in my previous message.

I'm sorry, but other than the assertion that asynchronous I/O is itself
a violation of the design goals I don't see anything that would lead to
this conclusion. And I don't see that that, in and of itself, is a
problem in the face of all the poor asynchronous I/O models that are
spreading like gangrene through the UNIX world. At the worst it's a matter
of choosing the lesser of two necessary evils.

I mean you seem to agree that *allowing* asynchronous I/O is a good idea.
Can you come up with a cleaner model? I'd love to see it.

I would agree that asynchronous I/O makes for problems in the traditional
big-kernel-with-ad-hoc-coroutines *implementation* of UNIX. But that's
another story.
-- 
 _--_|\  Peter da Silva. +1 713 274 5180. <peter at ficc.uu.net>.
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