On 08Aug2017 1151, Nathaniel Smith wrote:
It looks like Thread.join ultimately ends up blocking in Python/thread_nt.h:EnterNonRecursiveMutex, which has a maze of #ifdefs behind it -- I think there are 3 different implementation you might end up with, depending on how CPython was built? Two of them seem to ultimately block in WaitForSingleObject, which would be easy to adapt to handle control-C. Unfortunately I think the implementation that actually gets used on modern systems is the one that blocks in SleepConditionVariableSRW, and I don't see any easy way for a control-C to interrupt that. But maybe I'm missing something -- I'm not a Windows expert.
I'd have to dig back through the recent attempts at changing this, but I believe the SleepConditionVariableSRW path is unused for all versions of Windows. A couple of people (including myself) attempted to enable that code path, but it has some subtle issues that were causing test failures, so we abandoned all the attempts. Though ISTR that someone put in more effort than most of us, but I don't think we've merged it (and if we have, it'd only be in 3.7 at this stage). Cheers, Steve