Add stop function for roles

[jbesraa]

After merging #1092 #1095 and #1097 we would like to start completing #1066. One requirement we need is a function to terminate a role, for example for PoolSV2 we need to add PoolSV2::stop. Any ideas on how best to approach this would be appreciated!

[plebhash]

@jbesraa can you elaborate on the motivations for this?

what kind of scenario are we trying to mitigate?

my understanding is that we just want to avoid zombie tasks that stay alive after the test has finished running... if that's the case, I would try to keep handles and use them to explicitly shut down all tasks

[plebhash]

overall, we should be as conservative as possible, because otherwise we will start going down very deep rabbit holes

I was originally excited about #1120 because it felt like a low-hanging-fruit that would allow us to migrate our CI away from MG and patch bugs on the PoC roles in a more sustainable and scalable way on the near future

but if this task will impose the need for deep refactors into the roles, then the trade-offs are no longer worth it in my view

[GitGab19]

Hey @jbesraa did you find a workaround for this?
Have you explored the task collector option suggested by @Shourya742 last call?

[Shourya742]

@GitGab19 I am seeing new changes here: #1066. @jbesraa has introduced state machine in roles crate. I am not very certain why this approach is taken, as in one of the meetings it was decided to not add code specific to integration test suite in production code. But I guess thats the workaround, rather than killing the joinhandles.

[jbesraa]

I am closing this as its irrelevant atm. please move the discussion to #1066

[jbesraa]

#1066 (comment)