Commit Graph

9 Commits

Author SHA1 Message Date
Aikar
b2d81e21c5
Improve Chunk Prioritization and Internal Scheduler
In previous MC versions, we had a rather simple internal scheduler
for delayed tasks that would just keep pushing task back until desired
tick was reached.

The method it called to schedule the task changed behavior in 1.14, and now
this scheduler is not working nowhere near what it was supposed to be doing.

This was causing long delayed task to eat up CPU (In Oversleep for example)

Rewrite this to just use the CraftScheduler for scheduling delayed tasks.

Once this was fixed, it became quite clear the code that delayed ticket
additions for chunks based on distance was clearly not right, as it was
tested on the previous broken logic.

So the ticket delay process has been vastly revamped to be even smarter.
Chunks behind the player can load slower than the chunks in front of the player.
We also can delay ticket adding until one of its neighbors has loaded, as
this lets us get a smoother spiral out for the chunks (minus frustum intent).

Additionally on frustum previous commit inadvertently broke frustum trying to
fix an issue when the real fix lied elsewhere, so restore chunk priority so
it works again.
2020-06-09 03:17:25 -04:00
Aikar
7c001d64a5
More Improvements to Chunks
Fixed issues where urgent and prioritized chunks didn't actually
always get their priority boosted correctly....

Properly deprioritize non ticking chunks.
Limit recursion on watchdog prints to stop flooding as much
Remove neighbor priorities from watchdog to reduce information
reduce synchronization duration so that watch dog won't block main should main actually wake up
probably fixed a deadlock risk in watchdog printing also that was leading to crashes
fixed chunk holder enqueues not being processed correctly
added async catchers in some locations that should not be ran async

Fixed upstream bug where VITAL callbacks that must run on main actually could
sometimes run on the server thread pool causing alot of these nasty bugs we've seen lately!

This build will provide massive improvements to stability as well as even faster
sync chunk load/gens now that priority is correctly set.

Fixes #3435
2020-05-22 23:52:56 -04:00
Aikar
7e1525ea2d
Many improvements to chunk prioritization and bug fixes
Fixed a few bugs, and made numerous improvements.
Fixed issue where a sync chunk load could have its ticket removed and the
priority ticket could expire...
Still not perfect there but better than before.

Also fixed few other misc issues such as watchdog cpu usage, chunk queue update
had risk of double enqueue due to it no longer being a set.

Added much more information about chunk state to watchdog prints.

I see some more room for improvement even, but this is much better than before.

Fixes #3407
Fixes #3411
Fixes #3395
Fixes #3389
2020-05-20 05:13:01 -04:00
Aikar
614a664bd3
Implement Chunk Priority / Urgency System for Chunks
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)
2020-05-19 04:09:37 -04:00
Aikar
897dd2c840
Foundational work for Future Memory usage improvements
This commit doesn't do much on its own, but adds a new Java Cleaner API
that lets us hook into Garbage Collector events to reclaim pooled objects and
return them to the pool.

Adds framework for Network Packets to know when a packet has finished dispatching
to get an idea when a packet is done sending to players.

Rewrites PooledObjects impl to properly respect max pool size and remove
almost all risk of contention.

Bumps the Paper Async Task Queue to use 2 threads, and properly shuts it down on shutdown.
2020-05-16 21:38:19 -04:00
Aikar
36f34f01c0
Updated Upstream (Bukkit/CraftBukkit)
Upstream has released updates that appears to apply and compile correctly.
This update has not been tested by PaperMC and as with ANY update, please do your own testing

Bukkit Changes:
da9ef3c5 #496: Add methods to get/set ItemStacks in EquipmentSlots
3abebc9f #492: Let Tameable extend Animals rather than Entity
941111a0 #495: Expose ItemStack and hand used in PlayerShearEntityEvent
4fe19cae #494: InventoryView - Add missing Brewing FUEL_TIME

CraftBukkit Changes:
933e9094 #664: Add methods to get/set ItemStacks in EquipmentSlots
18722312 #662: Expose ItemStack and hand used in PlayerShearEntityEvent
2020-05-06 06:05:22 -04:00
Aikar
f37381ea8a
Optimize Network Manager to not need synchronization
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.
2020-05-06 05:28:47 -04:00
Aikar
57dd397155
Updated Upstream (Bukkit/CraftBukkit)
Upstream has released updates that appears to apply and compile correctly.
This update has not been tested by PaperMC and as with ANY update, please do your own testing

Bukkit Changes:
b999860d SPIGOT-2304: Add LootGenerateEvent

CraftBukkit Changes:
77fd87e4 SPIGOT-2304: Implement LootGenerateEvent
a1a705ee SPIGOT-5566: Doused campfires & fires should call EntityChangeBlockEvent
41712edd SPIGOT-5707: PersistentDataHolder not Persistent on API dropped Item
2020-05-01 18:03:57 -04:00
Ytnoos
bf698865f7
Revert "Re-track players that dismount from other players" 2020-04-22 03:16:31 -04:00