no return value for threading.Condition.wait(timeout)?

Carl Banks pavlovevidence at
Thu Jul 16 17:00:43 EDT 2009

On Jul 16, 8:12 am, Gabriel Rossetti <gabriel.rosse... at>
> Hello everyone,
> I am using threading.Condition.wait(timeout) and was surprised to see
> that there is no return value nor an exception when wait() is used w/ a
> timeout. How am I supposed to know if it was notified or if it timed out?

That's a good question.  Condition.wait seems to violate an invariant
if it can return without having acquired the underlying lock.  And if
it does the least it could do is to return a status so you know if you
have to skeddadle.

Workaround is to use the _is_owned() method of Condition to see if you
are the owner of the condition, but this method is undocumented.

cond = Condition()
while not ok_to_proceed():
    if not cond._is_owned():
        # must've timed out
        raise TimeOutException

Carl Banks

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