[Python-ideas] micro-threading PEP proposal (long) -- take 2!
dangyogi at gmail.com
Thu Aug 28 18:05:18 CEST 2008
Andrew Akira Toulouse wrote:
> Forgive the pedantry: do you mean "breathe", rather than "breath"?
> On Wed, Aug 27, 2008 at 6:42 PM, Bruce Frederiksen <dangyogi at gmail.com
> <mailto:dangyogi at gmail.com>> wrote:
> In this case, you're misunderstanding :-).
> What I meant by a "long running" micro_thread starving other
> micro-threads, was a micro_thread that doesn't do anything that
> would cause it to be suspended (e.g., I/O, sleep).
> For example, calculating the number PI to 2000 digits will starve
> other micro_threads.
> Each time a micro_thread does something which causes it to be
> suspended (like a file.read that needs to access the disk, a
> socket.recv or a time.sleep), other micro_threads may run. So the
> first micro_thread doesn't cause the whole os-thread (generally
> the whole Python program) to be suspended, like it does now.
> But if one micro_thread uses the CPU for a long time without doing
> any I/O, then other micro_threads are starved because
> micro_threads are non-preemptive (unlike os-threads).
> I'm adding a "breath" function that allows responsible
> micro_threads to "come up for air" periodically, to give other
> micro_threads a chance to run. But nothing forces a micro_thread
> to cooperate like this...
> I hopes this helps to clear things up!
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