cowboy_acceptors will not get updated with OTP relups

[ferd]

An improvement on the previous behaviour was introduced in: d9da533

The problem is that right now, the module tuple for the supervisor is []. When the OTP release handler will try to upgrade code, it will navigate through the OTP supervision tree and ask all of the supervisors to tell them what kind of code their children are running. By leaving it to an empty list, the module will be ignored and not upgraded.

To fix this, the module name must be added to the empty list ([cowboy_acceptor]). However, the acceptors are accepting (a blocking operation) and will be killed after a while if they do not reply to release_handler's requests.

The behaviour of the acceptors should be changed to accept only for a few (milli)seconds at a time, look for new messages (including upgrade ones, coming from the sys module), react to them, and then start accepting over again.

[essen]

I'm not sure this is an issue anymore. We have them upgrading through listener upgrades now. There's no real state to upgrade, just the code itself.

[ferd]

If that is the case, then it shouldn't be a problem anymore.

[essen]

Thanks!