From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Aikar 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 ea7b92b9ecb99bc995ab9a6ee5a974a0810778db..d886320211c7fa80960042c9b9ef4951eb34aaf1 100644 --- a/src/main/java/net/minecraft/world/level/chunk/PalettedContainer.java +++ b/src/main/java/net/minecraft/world/level/chunk/PalettedContainer.java @@ -32,14 +32,14 @@ public class PalettedContainer implements PaletteResize { private final T @org.jetbrains.annotations.Nullable [] presetValues; // Paper - Anti-Xray - Add preset values private volatile PalettedContainer.Data 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 } // Paper start - Anti-Xray - Add preset values @@ -113,7 +113,7 @@ public class PalettedContainer implements PaletteResize { } @Override - public int onResize(int newBits, T object) { + public synchronized int onResize(int newBits, T object) { // Paper - synchronize PalettedContainer.Data data = this.data; // Paper start - Anti-Xray - Add preset values @@ -160,7 +160,7 @@ public class PalettedContainer implements PaletteResize { 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); @@ -177,7 +177,7 @@ public class PalettedContainer implements PaletteResize { } - 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); } @@ -200,7 +200,7 @@ public class PalettedContainer implements PaletteResize { }); } - public void read(FriendlyByteBuf buf) { + public synchronized void read(FriendlyByteBuf buf) { // Paper - synchronize this.acquire(); try { @@ -218,7 +218,7 @@ public class PalettedContainer implements PaletteResize { // Paper start - Anti-Xray - Add chunk packet info @Deprecated public void write(FriendlyByteBuf buf) { this.write(buf, null, 0); } // Notice for updates: Please make sure this method isn't used anywhere - public void write(FriendlyByteBuf buf, @Nullable com.destroystokyo.paper.antixray.ChunkPacketInfo chunkPacketInfo, int bottomBlockY) { + public synchronized void write(FriendlyByteBuf buf, @Nullable com.destroystokyo.paper.antixray.ChunkPacketInfo chunkPacketInfo, int bottomBlockY) { // Paper - synchronize this.acquire(); try { @@ -275,7 +275,7 @@ public class PalettedContainer implements PaletteResize { return DataResult.success(new PalettedContainer<>(idList, provider, configuration, bitStorage, list, defaultValue, presetValues)); // Paper - Anti-Xray - Add preset values } - private PalettedContainer.DiscData write(IdMap idList, PalettedContainer.Strategy provider) { + private synchronized PalettedContainer.DiscData write(IdMap idList, PalettedContainer.Strategy provider) { // Paper - synchronize this.acquire(); PalettedContainer.DiscData var12;