Blow up if a plugin tries to mutate visibleChunks directly and prevent them
from doing so.
Also provide a safe get call if any plugins directly call get on it so
that it uses the special logic to check pending.
Also restores ABI for the visibleChunks field back to what it was too.
Additionally, remove the stack trace from Timings Stack Corruption for any
error thrown on Minecraft Timings, and tell them to get the error ABOVE this
instead, so people stop giving us useless error reports.
Also fixes a memory leak when the source map down sizes but dest map didn't,
which resulted in lingering references to old chunk holders.
Fixes#3414
Mark chunks that are blocking main thread for world generation as urgent
Implements a general priority system so that chunks that are sorted in
the generator queues can prioritize certain chunks over another.
Urgent chunks will jump to the front of the line, ensuring that a
sync chunk load on an ungenerated chunk does not lag the server for
a long period of time if the servers generator queues are filled with
lots of chunks already.
This massively reduces the lag spikes from sync chunk gens.
Then we further prioritize loading order so nearby chunks have higher
priority than distant chunks, reducing the pressure a high no tick
view distance holds on you.
Chunks in front of the player have higher priority, to help with
fast traveling players keep up with their movement.
This commit also improves single core cpu scenarios in that we will
now automatically disable Async Chunks as well as Minecrafts thread
pool.
It is never recommended to use async chunks on a single CPU as context
switching will be slower than just running it all on main.
This also bumps the number of server worker threads by default too.
Mojang does not utilize the workers in an effecient manner, resulting
in them using barely any sustained CPU.
So give it more workers so more chunks can be processed concurrently
This change also improves urgent chunk loading, so players flying into
unloaded chunks will hurt a little bit less (but still hurt)
Ping #3395#3363 (Not marking as closed, we need to make prevent moving work)
When crossing certain chunk boundaries, the client needlessly
calculates light maps for chunk neighbours. In some specific map
configurations, these calculations cause a 500ms+ freeze on the Client.
This patch basically serves as a workaround by sending light maps
to the client, so that it doesn't attempt to calculate them.
This mitigates the frametime impact to a minimum (but it's still there).
Aikar
Spottedleaf
MeFisto94