[PATCH 2 of 2] evolve: lock the working copy early in next and prev (issue5244)

[Pierre-Yves David]

On 10/16/2016 04:03 PM, Simon Farnsworth wrote:
> On 16/10/2016 12:43, Pierre-Yves David wrote:
>>
>>
>> On 10/08/2016 05:18 PM, Simon Farnsworth wrote:
>>> # HG changeset patch
>>> # User Simon Farnsworth <simonfar at fb.com>
>>> # Date 1475939634 25200
>>> #      Sat Oct 08 08:13:54 2016 -0700
>>> # Node ID 8a0c9c0158b3e9574a4571af3dce9978844b825d
>>> # Parent  ee284d7c5faa5d9f17853f51c17883844b985c58
>>> evolve: lock the working copy early in next and prev (issue5244)
>>>
>>> Both next and prev depend on a consistent working copy, but were
>>> waiting to
>>> take the lock until they were ready to alter the working copy.
>>>
>>> Take the lock before reading the working copy state, and do not
>>> release it
>>> until we're definitely not going to change the working copy.
>>
>> The fix approach seems good, but the implementation is a bit strangeto
>> me. See inline.
>>
> I can remove the early unlocks, but the goal is to unlock early when we
> no longer need the locks.

It does not seems like much is actually happening between the lock 
release and the end of the commands. Unless I'm missing something, I 
think we can just unlock at the end.

-- 
Pierre-Yves David