I'm don't quite understand the problem we're trying to fix:
Currently the launcher's latch is used for the following: a) worker process attach b) worker process exit and c) subscription creation. Since this same latch is used for multiple cases, the launcher process is not able to handle concurrent scenarios like: a) Launcher started a new apply worker and waiting for apply worker to attach and b) create subscription sub2 sending launcher wake up signal. In this scenario, both of them will set latch of the launcher process, the launcher process is not able to identify that both operations have occurred 1) worker is attached 2) subscription is created and apply worker should be started. As a result the apply worker does not get started for the new subscription created immediately and gets started after the timeout of 180 seconds.
I don't see how we could miss a notification. Yes, both events will set the same latch. Why is that a problem? The loop will see that the new worker has attached, and that the new subscription has been created, and process both events. Right?
-- Heikki Linnakangas Neon (https://neon.tech)
