VHDS subscription could refer a destructed init manager

[lambdai]

Description:

Brainstormed in my PR #9209 but then I realize the issue is there before.
#7617

The background is RdsRouteConfigSubscription has been shared by multiple providers across listeners.
Upon subscription construction the subscription keep a reference to the Init::Manager provided by the listener.
If the RDS config has VHDS field, VHDS subscription will be created and that Init::Manager reference will be dereferenced.
Since subscription is shared across listeners, the above Init::Manager might be already destructed with the initial listener.

Boom.

[stevenzzzz]

This is a similar problem as RDS in the scope of SRDS, where a new subscription might be created exceed listenerImpl life-span. I think we can fix it by depending on a noop init manager when we detect that the listener is gone. it's kinda of an addition to the #7617, we can probably solve both in one shot.

[lambdai]

Agree. Need to find another signal to indicate init_manager is not required.

[stale]

This issue has been automatically marked as stale because it has not had activity in the last 30 days. It will be closed in the next 7 days unless it is tagged "help wanted" or other activity occurs. Thank you for your contributions.

[stale]

This issue has been automatically closed because it has not had activity in the last 37 days. If this issue is still valid, please ping a maintainer and ask them to label it as "help wanted". Thank you for your contributions.

[stevenzzzz]

/assign stevenzzzz I will grab it

…

On Sun, Jan 19, 2020, 2:37 PM Matt Klein ***@***.***> wrote: Reopened #9254 <#9254>. — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#9254?email_source=notifications&email_token=AA2I6TGSU53N7SX4PD2S2ZDQ6STW5A5CNFSM4JXAJ2U2YY3PNVWWK3TUL52HS4DFWZEXG43VMVCXMZLOORHG65DJMZUWGYLUNFXW5KTDN5WW2ZLOORPWSZGOWB7NWPY#event-2961103679>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AA2I6TGTSARJPL6LU2ROJETQ6STW5ANCNFSM4JXAJ2UQ> .

[stevenzzzz]

I believe this is fixed by #9779, in RDS onConfigUpdate a local init-manager is used instead of listener's init_manager_ in VHDS's subscription creation.

[stevenzzzz]

apparently I can't close it. :)