From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Aikar <aikar@aikar.co> Date: Fri, 29 May 2020 20:29:02 -0400 Subject: [PATCH] Synchronize PalettedContainer instead of ThreadingDetector/Semaphore Mojang has flaws in their logic about chunks being concurrently wrote to. So we constantly see crashes around multiple threads writing. Additionally, java has optimized synchronization so well that its in many times faster than trying to manage read write locks for low contention situations. And this is extremely a low contention situation. diff --git a/src/main/java/net/minecraft/world/level/chunk/PalettedContainer.java b/src/main/java/net/minecraft/world/level/chunk/PalettedContainer.java index 6b37d460a76156162743d77d192f34366b29e5f9..268752a0b939abcaa9c7a302d2642b0c0fa2d331 100644 --- a/src/main/java/net/minecraft/world/level/chunk/PalettedContainer.java +++ b/src/main/java/net/minecraft/world/level/chunk/PalettedContainer.java @@ -30,14 +30,14 @@ public class PalettedContainer<T> implements PaletteResize<T>, PalettedContainer public final IdMap<T> registry; private volatile PalettedContainer.Data<T> data; private final PalettedContainer.Strategy strategy; - private final ThreadingDetector threadingDetector = new ThreadingDetector("PalettedContainer"); + // private final ThreadingDetector threadingDetector = new ThreadingDetector("PalettedContainer"); // Paper - unused public void acquire() { - this.threadingDetector.checkAndLock(); + // this.threadingDetector.checkAndLock(); // Paper - disable this - use proper synchronization } public void release() { - this.threadingDetector.checkAndUnlock(); + // this.threadingDetector.checkAndUnlock(); // Paper - disable this } public static <T> Codec<PalettedContainer<T>> codecRW(IdMap<T> idList, Codec<T> entryCodec, PalettedContainer.Strategy paletteProvider, T defaultValue) { @@ -104,7 +104,7 @@ public class PalettedContainer<T> implements PaletteResize<T>, PalettedContainer } @Override - public int onResize(int newBits, T object) { + public synchronized int onResize(int newBits, T object) { // Paper - synchronize PalettedContainer.Data<T> data = this.data; PalettedContainer.Data<T> data2 = this.createOrReuseData(data, newBits); data2.copyFrom(data.palette, data.storage); @@ -129,7 +129,7 @@ public class PalettedContainer<T> implements PaletteResize<T>, PalettedContainer return this.getAndSet(this.strategy.getIndex(x, y, z), value); } - private T getAndSet(int index, T value) { + private synchronized T getAndSet(int index, T value) { // Paper - synchronize int i = this.data.palette.idFor(value); int j = this.data.storage.getAndSet(index, i); return this.data.palette.valueFor(j); @@ -145,7 +145,7 @@ public class PalettedContainer<T> implements PaletteResize<T>, PalettedContainer } } - private void set(int index, T value) { + private synchronized void set(int index, T value) { // Paper - synchronize int i = this.data.palette.idFor(value); this.data.storage.set(index, i); } @@ -168,7 +168,7 @@ public class PalettedContainer<T> implements PaletteResize<T>, PalettedContainer intSet.forEach(id -> action.accept(palette.valueFor(id))); } - public void read(FriendlyByteBuf buf) { + public synchronized void read(FriendlyByteBuf buf) { // Paper - synchronize this.acquire(); try { @@ -183,7 +183,7 @@ public class PalettedContainer<T> implements PaletteResize<T>, PalettedContainer } @Override - public void write(FriendlyByteBuf buf) { + public synchronized void write(FriendlyByteBuf buf) { // Paper - synchronize this.acquire(); try { @@ -231,7 +231,7 @@ public class PalettedContainer<T> implements PaletteResize<T>, PalettedContainer } @Override - public PalettedContainerRO.PackedData<T> pack(IdMap<T> idList, PalettedContainer.Strategy paletteProvider) { + public synchronized PalettedContainerRO.PackedData<T> pack(IdMap<T> idList, PalettedContainer.Strategy paletteProvider) { // Paper - synchronize this.acquire(); PalettedContainerRO.PackedData var12;