[Twisted-Python] looping in a non-blocking way
projects at reedflute.com
Thu Mar 24 04:01:12 EST 2005
I have an application where I have several polling protocol instances
servicing an array of COM ports driven by timers using
reactor.callLater with typically 50 millisecond timing constants. I'm
also using FTP client protocol instances to concurrently refresh
locally cached data from ftp servers. These files may be quite large and
during the text parsing routines I end up with blocking loops which are
Text files my be parsed in a loop with something like:
for line in datalines:
For large files the above blocks - starving the other COM port protocols
drivers of processing time.
I have tried to "yield" to the reactor by calling reactor.iterate() in
the above loop trying to do what you would normally accomplish with
sleep(0) in a multithreaded application. This solution seemed to
partially solve the problem but I'm experiencing intermittent stability
problems with my polling protocol drivers that are normally quite
robust simply hanging up.
I'm now considering rewriting the above loop as a recursive function
I'm aware of twisted.flow but the examples given are a bit sparse and
obscure and having tried something like
it appears I don't understand how to apply twisted.flow
(iterators/coroutines) solve my particular problem.
I hope I'm missing something obvious and more elegant since the above
possible solutions seems like a lot of rework to solve a very simple
Any thoughts/advise would be much appreciated.
Web -> www.reedflute.com
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