[Python-Dev] generic async io (was: microthreading vs. async io)

[Nick Maclaren]

Greg Ewing <greg.ewing at canterbury.ac.nz> wrote:
>
> > An I/O operation passes a buffer, length, file and action and receives a
> > token back.
> 
> You seem to be using the word "threading" in a completely
> different way than usual here, which may be causing some
> confusion.

Not really, though I may have been unclear again.  Here is why that
approach is best regarded as a threading concept:

Perhaps the main current approach to using threads to implement
asynchronous I/O operates by the main threads doing just that, and
the I/O threads transferring the data synchronously.  The reason
that a token is needed is to avoid a synchronous data copy that
blocks both threads.

My general point is that all experience is that asynchronous I/O is
best done by separating it completely from threads, and defining a
proper asynchronous but NOT threaded interface.


Regards,
Nick Maclaren,
University of Cambridge Computing Service,
New Museums Site, Pembroke Street, Cambridge CB2 3QH, England.
Email:  nmm1 at cam.ac.uk
Tel.:  +44 1223 334761    Fax:  +44 1223 334679