Removes synchronization from sending packets
Makes normal packet sends no longer need to be wrapped and queued like it use to work.
Adds more packet queue immunities on top of keep alive to let the following scenarios go out
without delay:
- Keep Alive
- Chat
- Kick
- All of the packets during the Player Joined World event
Hoping that latter one helps join timeout issues more too for slow connections.
Removes processing packet queue off of main thread
- for the few cases where it is allowed, order is not necessary nor
should it even be happening concurrently in first place (handshaking/login/status)
Ensures packets sent asynchronously are dispatched on main thread
This helps ensure safety for ProtocolLib as packet listeners
are commonly accessing world state. This will allow you to schedule
a packet to be sent async, but itll be dispatched sync for packet
listeners to process.
This should solve some deadlock risks
This may provide a decent performance improvement because thread synchronization incurs a cache reset
so by avoiding ever entering a synchronized block, we get to avoid that, and packet sending is a really
hot activity.
Java 9+ doesn't allow using the exposed cleanup method, but added
a new method on Unsafe to do it.
So have to detect java version and use the appropriate strategy.
Mojang was semi leaking native memory here by relying on finalizers
to clean up the direct memory.
Finalizers have no guarantee on when they will be ran, and since this is
old generation memory, it might be a while before its called.
