Message 364485 - Python tracker

Message364485

Author	vstinner
Recipients	Mark.Shannon, eric.snow, jeremy.kloth, jkloth, larry, maciej.szulik, nanjekyejoannah, ncoghlan, phsilva, rhettinger, shihai1991, vstinner
Date	2020-03-17.22:09:58
SpamBayes Score	-1.0
Marked as misclassified	Yes
Message-id	<1584482999.07.0.0860750655891.issue39511@roundup.psfhosted.org>
In-reply-to

Content
I expect that for objects which are not commonly modified by two interpreters "at the same time", it should be fine. But None, True, small integer singletons, latin-1 str single character singletons, etc. objects are likely to be frequently accessed and so can become a bottleneck. Moreover, Python has an infamous feature: write (modify ob_refcnt) on "read-only" access :-D See "Copy-on-Read" feature popularized by Instagram ;-) https://instagram-engineering.com/copy-on-write-friendly-python-garbage-collection-ad6ed5233ddf

Content

I expect that for objects which are not commonly modified by two interpreters "at the same time", it should be fine.

But None, True, small integer singletons, latin-1 str single character singletons, etc. objects are likely to be frequently accessed and so can become a bottleneck.

Moreover, Python has an infamous feature: write (modify ob_refcnt) on "read-only" access :-D See "Copy-on-Read" feature popularized by Instagram ;-)

https://instagram-engineering.com/copy-on-write-friendly-python-garbage-collection-ad6ed5233ddf

History
Date	User	Action	Args
2020-03-17 22:09:59	vstinner	set	recipients: + vstinner, rhettinger, ncoghlan, larry, jkloth, phsilva, jeremy.kloth, Mark.Shannon, eric.snow, maciej.szulik, nanjekyejoannah, shihai1991
2020-03-17 22:09:59	vstinner	set	messageid: <1584482999.07.0.0860750655891.issue39511@roundup.psfhosted.org>
2020-03-17 22:09:59	vstinner	link	issue39511 messages
2020-03-17 22:09:59	vstinner	create