Message 263895 - Python tracker

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In-reply-to
Author	vstinner
Recipients	brett.cannon, eric.snow, larry, ncoghlan, random832, rhettinger, serhiy.storchaka, vstinner, xiang.zhang
Date	2016年04月21日.08:06:22
SpamBayes Score	-1.0
Marked as misclassified	Yes
Message-id	<1461225982.36.0.541231496411.issue26811@psf.upfronthosting.co.za>

Content
I suggest to remove the micro-optimization from Python 3.5 for safety. I'm ok to experiment a new safer implementation on Python 3.6 ;-) We have more time to fix the code in Python 3.6 if new issues are found. Setting the tuple size to zero looks simple and safe, but the overall hack deserves a comment to explain: * why you use a cached tuple * why the reference count can be different than 2: recursive calls * why do you change the tuple size

Content

I suggest to remove the micro-optimization from Python 3.5 for safety.
I'm ok to experiment a new safer implementation on Python 3.6 ;-) We have more time to fix the code in Python 3.6 if new issues are found. Setting the tuple size to zero looks simple and safe, but the overall hack deserves a comment to explain:
* why you use a cached tuple
* why the reference count can be different than 2: recursive calls
* why do you change the tuple size

History
Date	User	Action	Args
2016年04月21日 08:06:22	vstinner	set	recipients: + vstinner, brett.cannon, rhettinger, ncoghlan, larry, eric.snow, serhiy.storchaka, random832, xiang.zhang
2016年04月21日 08:06:22	vstinner	set	messageid: <1461225982.36.0.541231496411.issue26811@psf.upfronthosting.co.za>
2016年04月21日 08:06:22	vstinner	link	issue26811 messages
2016年04月21日 08:06:22	vstinner	create

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