[Seaside] [Glass] Why session locking is necessary for Seaside?

[Dale Henrichs]

On 03/22/2017 02:42 AM, Johan Brichau wrote:
>>> I am intrigued about the ORIGINAL needs of such a need. Because as Pharo and GemStone and too it makes me wonder if the lock would be needed on GemStone.
>> I've read some of the newer Seaside code and while I can easily tell that there is still session state being copied and restored (see senders and implementers of snapShotCopy and restoreFromSnapShot:), it is not easy to tell how it is being protected from logical or physical corruption ... WACache has a mutex protecting the cache updates, but I still don't see how the component snapshots are being protected from concurrent updates ...
> That should be the WAMutualExclusionFilter, no?
> This one is never installed in the Gemstone code.
>
Ah, that does look like the one ... so maybe you know how/if this filter 
is bypassed by ajax calls when running in Pharo ... or perhaps it's just 
more visible with GemStone?

Dale