Fake threads (was [Python-Dev] ActiveState & fork & Perl)

[Christian Tismer]

Vladimir Marangozov wrote:
...
> > too-simple-to-be-obvious?-ly y'rs  - tim
> 
> Yes. I'm trying to understand the following:
> 
> 1. What does a generator generate?

Trying my little understanding.

A generator generates a series of results if you ask for it.
That's done by a resume call (generator, resume your computation),
and the generate continues until he either comes to a suspend
(return a value, but be prepared to continue from here) or it
does a final return.

> 2. Clearly, what's the difference between a generator and a thread?

Threads can be scheduled automatically, and they don't return
values to each other, natively.
Generators are asymmetric to their callers, they're much like
functions.
Coroutines are more symmetric. They "return" to each other
values. They are not determined as caller and callee, but
they cooperate on the same level.
Therefore, threads and coroutines look more similar, just that
coroutines usually are'nt scheduled automatically. Add a scheduler,
don't pass values, and you have threads, nearly.
(of course I dropped the I/O blocking stuff which doesn't
apply and isn't the intent of fake threads).

ciao - chris

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