Rewrite chunk system (#8177)

Patch documentation to come

Issues with the old system that are fixed now:
- World generation does not scale with cpu cores effectively.
- Relies on the main thread for scheduling and maintaining chunk state, dropping chunk load/generate rates at lower tps.
- Unreliable prioritisation of chunk gen/load calls that block the main thread.
- Shutdown logic is utterly unreliable, as it has to wait for all chunks to unload - is it guaranteed that the chunk system is in a state on shutdown that it can reliably do this? Watchdog shutdown also typically failed due to thread checks, which is now resolved.
- Saving of data is not unified (i.e can save chunk data without saving entity data, poses problems for desync if shutdown is really abnormal.
- Entities are not loaded with chunks. This caused quite a bit of headache for Chunk#getEntities API, but now the new chunk system loads entities with chunks so that they are ready whenever the chunk loads in. Effectively brings the behavior back to 1.16 era, but still storing entities in their own separate regionfiles.

The above list is not complete. The patch documentation will complete it.

New chunk system hard relies on starlight and dataconverter, and most importantly the new concurrent utilities in ConcurrentUtil.

Some of the old async chunk i/o interface (i.e the old file io thread reroutes _some_ calls to the new file io thread) is kept for plugin compat reasons. It will be removed in the next major version of minecraft.

The old legacy chunk system patches have been moved to the removed folder in case we need them again.

1 files changed, 67 insertions, 0 deletions

diff --git a/patches/server/0778-Fix-tripwire-state-inconsistency.patch b/patches/server/0778-Fix-tripwire-state-inconsistency.patch
new file mode 100644
index 0000000000..eba71d4136
--- /dev/null
+++ b/patches/server/0778-Fix-tripwire-state-inconsistency.patch
@@ -0,0 +1,67 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Nassim Jahnke <[email protected]>
+Date: Sun, 19 Dec 2021 21:11:20 +0100
+Subject: [PATCH] Fix tripwire state inconsistency
+
+This patch prevents updating and re-setting the tripwire when being removed in certain conditions
+
+diff --git a/src/main/java/net/minecraft/world/level/block/TripWireBlock.java b/src/main/java/net/minecraft/world/level/block/TripWireBlock.java
+index 4e2fb4ee8e46b3c363992ff23e26f5a648c5f003..7f60175bf671d282c11e9084670d2bb900968255 100644
+--- a/src/main/java/net/minecraft/world/level/block/TripWireBlock.java
++++ b/src/main/java/net/minecraft/world/level/block/TripWireBlock.java
+@@ -74,7 +74,7 @@ public class TripWireBlock extends Block {
+     @Override
+     public void onRemove(BlockState state, Level world, BlockPos pos, BlockState newState, boolean moved) {
+         if (!moved && !state.is(newState.getBlock())) {
+-            this.updateSource(world, pos, (BlockState) state.setValue(TripWireBlock.POWERED, true));
++            this.updateSource(world, pos, (BlockState) state.setValue(TripWireBlock.POWERED, true), true); // Paper - fix state inconsistency
+         }
+     }
+ 
+@@ -89,6 +89,12 @@ public class TripWireBlock extends Block {
+     }
+ 
+     private void updateSource(Level world, BlockPos pos, BlockState state) {
++        // Paper start - fix state inconsistency
++        this.updateSource(world, pos, state, false);
++    }
++
++    private void updateSource(Level world, BlockPos pos, BlockState state, boolean beingRemoved) {
++        // Paper end
+         Direction[] aenumdirection = new Direction[]{Direction.SOUTH, Direction.WEST};
+         int i = aenumdirection.length;
+         int j = 0;
+@@ -104,7 +110,7 @@ public class TripWireBlock extends Block {
+ 
+                     if (iblockdata1.is((Block) this.hook)) {
+                         if (iblockdata1.getValue(TripWireHookBlock.FACING) == enumdirection.getOpposite()) {
+-                            this.hook.calculateState(world, blockposition1, iblockdata1, false, true, k, state);
++                            this.hook.calculateState(world, blockposition1, iblockdata1, false, true, k, state, beingRemoved); // Paper - fix state inconsistency
+                         }
+                     } else if (iblockdata1.is((Block) this)) {
+                         ++k;
+diff --git a/src/main/java/net/minecraft/world/level/block/TripWireHookBlock.java b/src/main/java/net/minecraft/world/level/block/TripWireHookBlock.java
+index 4a516828e5c6abd63511ee7c93fcff11203cf8d0..004dce26ff073f1de52a84cd425c4f60fdab5e50 100644
+--- a/src/main/java/net/minecraft/world/level/block/TripWireHookBlock.java
++++ b/src/main/java/net/minecraft/world/level/block/TripWireHookBlock.java
+@@ -108,6 +108,12 @@ public class TripWireHookBlock extends Block {
+     }
+ 
+     public void calculateState(Level world, BlockPos pos, BlockState state, boolean beingRemoved, boolean flag1, int i, @Nullable BlockState iblockdata1) {
++        // Paper start - fix tripwire inconsistency
++        this.calculateState(world, pos, state, beingRemoved, flag1, i, iblockdata1, false);
++    }
++
++    public void calculateState(Level world, BlockPos pos, BlockState state, boolean beingRemoved, boolean flag1, int i, @Nullable BlockState iblockdata1, boolean tripWireBeingRemoved) {
++        // Paper end
+         Direction enumdirection = (Direction) state.getValue(TripWireHookBlock.FACING);
+         boolean flag2 = (Boolean) state.getValue(TripWireHookBlock.ATTACHED);
+         boolean flag3 = (Boolean) state.getValue(TripWireHookBlock.POWERED);
+@@ -141,6 +147,7 @@ public class TripWireHookBlock extends Block {
+                 boolean flag7 = (Boolean) iblockdata2.getValue(TripWireBlock.POWERED);
+ 
+                 flag5 |= flag6 && flag7;
++                if (k != i || !tripWireBeingRemoved || !flag6) // Paper - don't update the tripwire again if being removed and not disarmed
+                 aiblockdata[k] = iblockdata2;
+                 if (k == i) {
+                     world.scheduleTick(pos, (Block) this, 10);