[Python-Dev] Twisted Isn't Specific (was Re: Trial balloon: microthreads library in stdlib)

[Phillip J. Eby]

At 04:25 PM 2/15/2007 +1300, Greg Ewing wrote:
>Phillip J. Eby wrote:
>>peak.events, for example, lets you have multiple event loops running in 
>>the same or different threads.
>
>Different threads is okay if you're willing to use threads,
>but you might not. The reason you're using an event loop
>may well be precisely so that you *don't* have to use
>threads.
>
>And... how do you run multiple event loops simultaneously
>in the *same* thread?

When one is nested inside the other.  This isn't a common need, but it's 
occasionally useful if you need to switch back and forth between blocking 
and non-blocking code.  For example, suppose that you have some code that 
wants to offer a synchronous interface to an asynchronous library...  and 
the synchronous code is being called from a FastCGI "accept" event 
loop.  The inner code can't use the outer event loop, because the outer 
loop isn't going to proceed until the inner code is finished.