Realtime capabilities?

Aahz Maruch aahz at panix.com
Sun Sep 23 05:39:35 CEST 2001


In article <mailman.1001181266.9227.python-list at python.org>,
Tim Peters <tim.one at home.com> wrote:
>
>This means that an Erlang process (unlike a Python thread) can't hog
>the CPU for a long time (provided the native OS is letting Erlang
>run).  In addition, the Erlang process scheduler guarantees fairness.
>Thus, and so long as Erlang is getting cycles, each Erlang process is
>"guaranteed" to get a timeslice before X seconds have passed (where
>X depends on lots of stuff, including the total number of Erlang
>processes running).  A programmer can exploit all that to deliver
>probabilistic bounds on response time.
>
>So "soft" means "no, we can't absolutely guarantee anything, but we've
>designed the language from the ground up to make it very likely that
>what we deliver in practice will be 'good enough', and provided you
>program intelligently in our model".

In other words, if the original poster is doing more than a tiny amount
of I/O, standard Python/OS threads will probably beat Erlang processes
for fairness, but if an application is almost completely compute-bound,
Erlang will probably beat even Stackless Python.
-- 
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