The lock in DataWatcher is used to prevent concurrent modifications
to the 'd' field (entries in MCP). However any modifications to
this map only occur on initialization of an Entity in its
constructor. This modification is write-locked.
Every other access is through a readlock, which allows
the threads to pass if there is no thread holding the
writelock.
Since the writelock is only obtained in the constructor
of the Entity, the further readlocks are actually
useless (which get obtained on set, get, etc calls).
The entries field ('d' currently) has also been declared as
Int2ObjectOpenHashMap to avoid autoboxing on put(), get(), etc
calls.
Upstream has released updates that appear to apply compile correctly.
This update has not been tested by PaperMC and as with ANY update, please do your own testing.
Bukkit Changes:
d2834556 SPIGOT-4219: Event for PigZombies angering.
CraftBukkit Changes:
a9c796f1 SPIGOT-4184: Fix furnaces not matching Vanilla smelt or animations
195f071e SPIGOT-4219: Event for PigZombies angering.
5e3082c7 SPIGOT-4230: Improve legacy block types
This enables us a fast reference to the entities current chunk instead
of having to look it up by hashmap lookups.
We also store counts by type to further enable other performance optimizations in later patches.
CraftBukkit removed their implementation that caused this issue,
switching to Mojang's implementation which doesn't appear to share it. I
already removed the important bit in the last upstream merge, this is
just unused and unnecessary now. So we remove it.
