Re: select

Guido van Rossum (Guido.van.Rossum@cwi.nl)
Mon, 29 Jun 1992 11:12:41 +0200

(See also my previous message where I explain that Jack Jansen has
just created a BSD select interface.)

>The question is how do you specify you wish to select/poll on it
>for both reading and writing? Remember, sockets are bi-directional.

I'd say specify it twice, once for reading and once for writing. This
works with Jack's implementation. Or is there a limitation to poll
that makes this impossible?

>I like that. But you should make it milliseconds since that is what
>the select() and poll() actually take. (Although for the project I am
>working on, I will probably only set it for 5-10 MINUTES :) )

The standard solution in Python for this is floating point. I still
want to change the time.sleep() function to accept a floating point
number so I can get rid of the separate time.millisleep() function --
the module time predates the existence of floating point in Python...

>The problem with poll() is that on some platforms, it handles
>sockets, pipes, and files differently than select(). But I think
>that the C code should be able to select which one you wish
>to use via a #define statement when you do the compile.

In the event that I or someone else may have to create an
implementation of Jack's select.select() using SYSV poll(), can you
(or another SYSV guru) enlighten me as to the nature of these
differences?

--Guido van Rossum, CWI, Amsterdam <guido@cwi.nl>
"What a senseless waste of human life"