store: fix race condition on stats token allocation

store: fix race condition on stats token allocation



https://code.launchpad.net/~niemeyer/juju-core/fix-store-token-race/+merge/122944

(do not edit description out of merge proposal)

[niemeyer, 2012-09-05 20:57:15]

Please take a look.

[dave_cheney.net, 2012-09-05 21:17:39]

On 2012/09/05 20:57:15, niemeyer wrote:
> Please take a look.

Thank you for fixing this. Looks good I guess, but I dont' really understand the
fix. By ensuring an index exists, does this fix the race ?

[niemeyer, 2012-09-06 02:28:12]

Please take a look.

[niemeyer, 2012-09-06 02:29:24]

On 2012/09/05 21:17:39, dfc wrote:
> Thank you for fixing this. Looks good I guess, but I dont' really understand
the
> fix. By ensuring an index exists, does this fix the race ?

Yeah, the race was already anticipated, but it trusted on the database to tell
"Hey, that already exists!", and since there was no unique index on the field,
that was not happening.

[dave_cheney.net, 2012-09-06 02:30:12]

LGTM.

On Thu, Sep 6, 2012 at 12:29 PM,  <n13m3y3r@gmail.com> wrote:
> On 2012/09/05 21:17:39, dfc wrote:
>>
>> Thank you for fixing this. Looks good I guess, but I dont' really
>
> understand the
>>
>> fix. By ensuring an index exists, does this fix the race ?
>
>
> Yeah, the race was already anticipated, but it trusted on the database
> to tell "Hey, that already exists!", and since there was no unique index
> on the field, that was not happening.
>
> https://codereview.appspot.com/6490083/

[fwereade, 2012-09-06 07:02:28]

LGTM

[niemeyer, 2012-09-06 13:58:25]

*** Submitted:

store: fix race condition on stats token allocation

R=dfc, fwereade
CC=
https://codereview.appspot.com/6490083