From @AlexDaniel

https://github.com/rakudo/rakudo/blob/9594a3ece38ca212023cf3ece7405d955303db13/src/core/asyncops.pm#L50

<jnthn> I thought I killed that off once
<jnthn> I did in 539b5f44ef3f pre-xmas
<jnthn> Because I thought it was pretty ridiculous having a non-atomic CAS in there :/
<jnthn> I made the mistake of tossing it with something else and it seems it got restored later as if I did it by accident rather than by quiet sleight of hand :P
<AlexDaniel> jnthn​: can you take care of it now? :)
<jnthn> AlexDaniel​: Well, we could actually do with a working cas... :P
<jnthn> (A few things I'd like to do could use it)
<jnthn> So I'll probably just fix it sometime next year :)
<jnthn> AlexDaniel​: Feel free, and mark it [CONC]; I watch the CONC list for stuff to do :)

From @jnthn

On Tue, 27 Dec 2016 12​:32​:50 -0800, alex.jakimenko@​gmail.com wrote​:

https://github.com/rakudo/rakudo/blob/9594a3ece38ca212023cf3ece7405d955303db13/src/core/asyncops.pm#L50

<jnthn> I thought I killed that off once
<jnthn> I did in 539b5f44ef3f pre-xmas
<jnthn> Because I thought it was pretty ridiculous having a non-atomic
CAS in there :/
<jnthn> I made the mistake of tossing it with something else and it
seems it got restored later as if I did it by accident rather than by
quiet sleight of hand :P
<AlexDaniel> jnthn​: can you take care of it now? :)
<jnthn> AlexDaniel​: Well, we could actually do with a working cas...
:P
<jnthn> (A few things I'd like to do could use it)
<jnthn> So I'll probably just fix it sometime next year :)
<jnthn> AlexDaniel​: Feel free, and mark it [CONC]; I watch the CONC
list for stuff to do :)

This got sorted out. There's now lots of tests that cas really does an atomic compare and swap (e.g. S17-lowlevel/cas.t).

The RT System itself - Status changed from 'new' to 'open'

@jnthn - Status changed from 'open' to 'resolved'