generators shared among threads

Alan Kennedy alanmk at hotmail.com
Sun Mar 5 15:14:47 CET 2006


[jess.austin at gmail.com]
> def f()
>     i = 0
>     while True:
>         yield i
>         i += 1
> g=f()
>
> If I pass g around to various threads and I want them to always be
> yielded a unique value, will I have a race condition?

Yes.

Generators can be shared between threads, but they cannot be resumed
from two threads at the same time.

You should wrap it in a lock to ensure that only one thread at a time
can resume the generator.

Read this thread from a couple of years back about the same topic.

Suggested generator to add to threading module.
http://groups.google.com/group/comp.lang.python/browse_frm/thread/76aa2afa913fe4df/a2ede21f7dd78f34#a2ede21f7dd78f34

Also contained in that thread is an implementation of Queue.Queue which
supplies values from a generator, and which does not require a separate
thread to generate values.

HTH,

--
alan kennedy
------------------------------------------------------
email alan:              http://xhaus.com/contact/alan




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