Use static ThreadLocal for light engine propagator

The propagator has been changed so that its world may be updated.
This reduces extra memory by only requiring one propagator to be
cached per thread, rather than one propagator per world per thread.

This change also avoids the dodgy behavior of ThreadLocal retaining
references to values long after they would be collectable.

Fixes #13234

Author: Spottedleaf

paper-server/patches/features/0001-Moonrise-optimisation-patches.patch

@@ -18182,7 +18182,7 @@ index 0000000000000000000000000000000000000000..ed80017c8f257b981d626a37ffc5480d
 +}
 diff --git a/ca/spottedleaf/moonrise/patches/starlight/light/BlockStarLightEngine.java b/ca/spottedleaf/moonrise/patches/starlight/light/BlockStarLightEngine.java
 new file mode 100644
-index 0000000000000000000000000000000000000000..fa7b784a89626e8528c249d7889a598bd7ee3d49
+index 0000000000000000000000000000000000000000..b623fb6974f5c4875a1ddc09053e72e6e67dda17
 --- /dev/null
 +++ b/ca/spottedleaf/moonrise/patches/starlight/light/BlockStarLightEngine.java
 @@ -0,0 +1,280 @@
@@ -18208,8 +18208,8 @@ index 0000000000000000000000000000000000000000..fa7b784a89626e8528c249d7889a598b
 +
 +public final class BlockStarLightEngine extends StarLightEngine {
 +
-+    public BlockStarLightEngine(final Level world) {
-+        super(false, world);
++    public BlockStarLightEngine() {
++        super(false);
 +    }
 +
 +    @Override
@@ -18915,10 +18915,10 @@ index 0000000000000000000000000000000000000000..5c7b3804cdbcb0a873a0d195325c2658
 +}
 diff --git a/ca/spottedleaf/moonrise/patches/starlight/light/SkyStarLightEngine.java b/ca/spottedleaf/moonrise/patches/starlight/light/SkyStarLightEngine.java
 new file mode 100644
-index 0000000000000000000000000000000000000000..f9aef289e9a2d6f63c98c72c56ef32b8793f57f4
+index 0000000000000000000000000000000000000000..cdb679fb6e3d342efc776329124209d1f433cc8f
 --- /dev/null
 +++ b/ca/spottedleaf/moonrise/patches/starlight/light/SkyStarLightEngine.java
-@@ -0,0 +1,681 @@
+@@ -0,0 +1,689 @@
 +package ca.spottedleaf.moonrise.patches.starlight.light;
 +
 +import ca.spottedleaf.moonrise.common.util.WorldUtil;
@@ -18971,11 +18971,21 @@ index 0000000000000000000000000000000000000000..f9aef289e9a2d6f63c98c72c56ef32b8
 +        Arrays.fill(this.heightMapBlockChange, Integer.MIN_VALUE); // clear heightmap
 +    }
 +
-+    protected final boolean[] nullPropagationCheckCache;
++    protected boolean[] nullPropagationCheckCache;
 +
-+    public SkyStarLightEngine(final Level world) {
-+        super(true, world);
-+        this.nullPropagationCheckCache = new boolean[WorldUtil.getTotalLightSections(world)];
++    public SkyStarLightEngine() {
++        super(true);
++    }
++
++    @Override
++    public void setWorld(final Level world) {
++        super.setWorld(world);
++        if (world != null) {
++            final int minArraySize = WorldUtil.getTotalLightSections(world);
++            if (this.nullPropagationCheckCache == null || this.nullPropagationCheckCache.length < minArraySize) {
++                this.nullPropagationCheckCache = new boolean[minArraySize];
++            }
++        }
 +    }
 +
 +    @Override
@@ -19361,8 +19371,6 @@ index 0000000000000000000000000000000000000000..f9aef289e9a2d6f63c98c72c56ef32b8
 +        this.performLightDecrease(lightAccess);
 +    }
 +
-+    protected final int[] heightMapGen = new int[32 * 32];
-+
 +    @Override
 +    protected void lightChunk(final LightChunkGetter lightAccess, final ChunkAccess chunk, final boolean needsEdgeChecks) {
 +        this.rewriteNibbleCacheForSkylight(chunk);
@@ -19602,10 +19610,10 @@ index 0000000000000000000000000000000000000000..f9aef289e9a2d6f63c98c72c56ef32b8
 +}
 diff --git a/ca/spottedleaf/moonrise/patches/starlight/light/StarLightEngine.java b/ca/spottedleaf/moonrise/patches/starlight/light/StarLightEngine.java
 new file mode 100644
-index 0000000000000000000000000000000000000000..7ba2b8d58a78662fda7f2b8f4c8c87b8e8ecb275
+index 0000000000000000000000000000000000000000..c6222bfb75706052df41d821f2fcfc4620ce3672
 --- /dev/null
 +++ b/ca/spottedleaf/moonrise/patches/starlight/light/StarLightEngine.java
-@@ -0,0 +1,1438 @@
+@@ -0,0 +1,1450 @@
 +package ca.spottedleaf.moonrise.patches.starlight.light;
 +
 +import ca.spottedleaf.concurrentutil.util.IntegerUtil;
@@ -19696,17 +19704,17 @@ index 0000000000000000000000000000000000000000..7ba2b8d58a78662fda7f2b8f4c8c87b8
 +    // for the y chunk section it's from [minLightSection, maxLightSection] or [0, maxLightSection - minLightSection]
 +    // index = x + (z * 5) + (y * 25)
 +    // null index indicates the chunk section doesn't exist (empty or out of bounds)
-+    protected final LevelChunkSection[] sectionCache;
++    protected LevelChunkSection[] sectionCache;
 +
 +    // the exact same as above, except for storing fast access to SWMRNibbleArray
 +    // for the y chunk section it's from [minLightSection, maxLightSection] or [0, maxLightSection - minLightSection]
 +    // index = x + (z * 5) + (y * 25)
-+    protected final SWMRNibbleArray[] nibbleCache;
++    protected SWMRNibbleArray[] nibbleCache;
 +
 +    // the exact same as above, except for storing fast access to nibbles to call change callbacks for
 +    // for the y chunk section it's from [minLightSection, maxLightSection] or [0, maxLightSection - minLightSection]
 +    // index = x + (z * 5) + (y * 25)
-+    protected final boolean[] notifyUpdateCache;
++    protected boolean[] notifyUpdateCache;
 +
 +    // always initialsed during start of lighting.
 +    // index = x + (z * 5)
@@ -19732,27 +19740,39 @@ index 0000000000000000000000000000000000000000..7ba2b8d58a78662fda7f2b8f4c8c87b8
 +
 +    protected final boolean skylightPropagator;
 +    protected final int emittedLightMask;
-+    protected final boolean isClientSide;
++    protected boolean isClientSide;
 +
-+    protected final Level world;
-+    protected final int minLightSection;
-+    protected final int maxLightSection;
-+    protected final int minSection;
-+    protected final int maxSection;
++    protected Level world;
++    protected int minLightSection;
++    protected int maxLightSection;
++    protected int minSection;
++    protected int maxSection;
 +
-+    protected StarLightEngine(final boolean skylightPropagator, final Level world) {
++    protected StarLightEngine(final boolean skylightPropagator) {
 +        this.skylightPropagator = skylightPropagator;
 +        this.emittedLightMask = skylightPropagator ? 0 : 0xF;
-+        this.isClientSide = world.isClientSide();
++    }
++
++    public void setWorld(final Level world) {
 +        this.world = world;
-+        this.minLightSection = WorldUtil.getMinLightSection(world);
-+        this.maxLightSection = WorldUtil.getMaxLightSection(world);
-+        this.minSection = WorldUtil.getMinSection(world);
-+        this.maxSection = WorldUtil.getMaxSection(world);
++        if (world != null) {
++            this.isClientSide = world.isClientSide();
++            this.minLightSection = WorldUtil.getMinLightSection(world);
++            this.maxLightSection = WorldUtil.getMaxLightSection(world);
++            this.minSection = WorldUtil.getMinSection(world);
++            this.maxSection = WorldUtil.getMaxSection(world);
++            final int minArraySize = 5 * 5 * ((this.maxLightSection - this.minLightSection + 1) + 2); // add two extra sections for buffer
 +
-+        this.sectionCache = new LevelChunkSection[5 * 5 * ((this.maxLightSection - this.minLightSection + 1) + 2)]; // add two extra sections for buffer
-+        this.nibbleCache = new SWMRNibbleArray[5 * 5 * ((this.maxLightSection - this.minLightSection + 1) + 2)]; // add two extra sections for buffer
-+        this.notifyUpdateCache = new boolean[5 * 5 * ((this.maxLightSection - this.minLightSection + 1) + 2)]; // add two extra sections for buffer
++            if (this.sectionCache == null || this.sectionCache.length < minArraySize) {
++                this.sectionCache = new LevelChunkSection[minArraySize];
++            }
++            if (this.nibbleCache == null || this.nibbleCache.length < minArraySize) {
++                this.nibbleCache = new SWMRNibbleArray[minArraySize];
++            }
++            if (this.notifyUpdateCache == null || this.notifyUpdateCache.length < minArraySize) {
++                this.notifyUpdateCache = new boolean[minArraySize];
++            }
++        }
 +    }
 +
 +    protected final void setupEncodeOffset(final int centerX, final int centerY, final int centerZ) {
@@ -21046,10 +21066,10 @@ index 0000000000000000000000000000000000000000..7ba2b8d58a78662fda7f2b8f4c8c87b8
 +}
 diff --git a/ca/spottedleaf/moonrise/patches/starlight/light/StarLightInterface.java b/ca/spottedleaf/moonrise/patches/starlight/light/StarLightInterface.java
 new file mode 100644
-index 0000000000000000000000000000000000000000..649042cd0a83aaf6866b09b21dfc54b337320111
+index 0000000000000000000000000000000000000000..7faf226b753a03e03b0dec9bbfcc94a6c3f5bc0f
 --- /dev/null
 +++ b/ca/spottedleaf/moonrise/patches/starlight/light/StarLightInterface.java
-@@ -0,0 +1,920 @@
+@@ -0,0 +1,936 @@
 +package ca.spottedleaf.moonrise.patches.starlight.light;
 +
 +import ca.spottedleaf.concurrentutil.collection.MultiThreadedQueue;
@@ -21099,8 +21119,8 @@ index 0000000000000000000000000000000000000000..649042cd0a83aaf6866b09b21dfc54b3
 +    public final Level world;
 +    public final LightChunkGetter lightAccess;
 +
-+    private final ThreadLocal<SkyStarLightEngine> cachedSkyPropagator;
-+    private final ThreadLocal<BlockStarLightEngine> cachedBlockPropagator;
++    private static final ThreadLocal<SkyStarLightEngine> SKY_PROPAGATOR = new ThreadLocal<>();
++    private static final ThreadLocal<BlockStarLightEngine> BLOCK_PROPAGATOR = new ThreadLocal<>();
 +
 +    private final LightQueue lightQueue;
 +
@@ -21121,8 +21141,6 @@ index 0000000000000000000000000000000000000000..649042cd0a83aaf6866b09b21dfc54b3
 +    public StarLightInterface(final LightChunkGetter lightAccess, final boolean hasSkyLight, final boolean hasBlockLight, final LevelLightEngine lightEngine) {
 +        this.lightAccess = lightAccess;
 +        this.world = lightAccess == null ? null : (Level)lightAccess.getLevel();
-+        this.cachedSkyPropagator = hasSkyLight && lightAccess != null ? new ThreadLocal<>() : null;
-+        this.cachedBlockPropagator = hasBlockLight && lightAccess != null ? new ThreadLocal<>() : null;
 +        this.isClientSide = !(this.world instanceof ServerLevel);
 +        if (this.world == null) {
 +            this.minSection = -4;
@@ -21411,43 +21429,61 @@ index 0000000000000000000000000000000000000000..649042cd0a83aaf6866b09b21dfc54b3
 +    }
 +
 +    public SkyStarLightEngine getSkyLightEngine() {
-+        if (this.cachedSkyPropagator == null) {
++        if (!this.hasSkyLight || this.world == null) {
 +            return null;
 +        }
-+        final SkyStarLightEngine ret = this.cachedSkyPropagator.get();
-+        this.cachedSkyPropagator.set(null);
++
++        SkyStarLightEngine ret = SKY_PROPAGATOR.get();
++        SKY_PROPAGATOR.set(null);
 +
 +        if (ret == null) {
-+            return new SkyStarLightEngine(this.world);
++            ret = new SkyStarLightEngine();
 +        }
++
++        ret.setWorld(this.world);
++
 +        return ret;
 +    }
 +
 +    public void releaseSkyLightEngine(final SkyStarLightEngine engine) {
-+        if (this.cachedSkyPropagator == null || this.cachedSkyPropagator.get() != null) {
++        if (engine != null) {
++            engine.setWorld(null);
++        }
++
++        if (!this.hasSkyLight || this.world == null || SKY_PROPAGATOR.get() != null) {
 +            return;
 +        }
-+        this.cachedSkyPropagator.set(engine);
++
++        SKY_PROPAGATOR.set(engine);
 +    }
 +
 +    public BlockStarLightEngine getBlockLightEngine() {
-+        if (this.cachedBlockPropagator == null) {
++        if (!this.hasBlockLight || this.world == null) {
 +            return null;
 +        }
-+        final BlockStarLightEngine ret = this.cachedBlockPropagator.get();
-+        this.cachedBlockPropagator.set(null);
++
++        BlockStarLightEngine ret = BLOCK_PROPAGATOR.get();
++        BLOCK_PROPAGATOR.set(null);
 +
 +        if (ret == null) {
-+            return new BlockStarLightEngine(this.world);
++            ret = new BlockStarLightEngine();
 +        }
++
++        ret.setWorld(this.world);
++
 +        return ret;
 +    }
 +
 +    public void releaseBlockLightEngine(final BlockStarLightEngine engine) {
-+        if (this.cachedBlockPropagator == null || this.cachedBlockPropagator.get() != null) {
++        if (engine != null) {
++            engine.setWorld(null);
++        }
++
++        if (!this.hasBlockLight || this.world == null || BLOCK_PROPAGATOR.get() != null) {
 +            return;
 +        }
-+        this.cachedBlockPropagator.set(engine);
++
++        BLOCK_PROPAGATOR.set(engine);
 +    }
 +
 +    public LightQueue.ChunkTasks blockChange(final BlockPos pos) {
@@ -21934,7 +21970,7 @@ index 0000000000000000000000000000000000000000..649042cd0a83aaf6866b09b21dfc54b3
 +            }
 +
 +            public boolean markTicketAdded() {
-+                return !this.ticketAdded.get() && !this.ticketAdded.getAndSet(true);
++                return !this.ticketAdded.get() && false == this.ticketAdded.compareAndExchange(false, true);
 +            }
 +
 +            public void schedule() {
@@ -27000,7 +27036,7 @@ index 704733ff5e558a12f2f9dde924ab4c507745595d..5e305c9a64e856de70ed787901c01d09
      }
 
 diff --git a/net/minecraft/server/level/ServerPlayer.java b/net/minecraft/server/level/ServerPlayer.java
-index a5bc4e8a3dde40c416c05e91dfec25bc7efdd013..66c25f323b9a19e25fcaea782dc72f477fd32629 100644
+index 53623b518266edc1436dbba3d965386dc31e6e6c..ecc39329af8722c3c3341d67bee1d22d7ccc7a4d 100644
 --- a/net/minecraft/server/level/ServerPlayer.java
 +++ b/net/minecraft/server/level/ServerPlayer.java
 @@ -201,7 +201,7 @@ import net.minecraft.world.scores.Team;