Avoid Unsafe on paper (#1678)

worldedit-bukkit/adapters/adapter-1_17_1/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/fawe/v1_17_R1_2/PaperweightGetBlocks.java

@@ -1,7 +1,6 @@
 package com.sk89q.worldedit.bukkit.adapter.impl.fawe.v1_17_R1_2;
 
 import com.fastasyncworldedit.bukkit.adapter.BukkitGetBlocks;
-import com.fastasyncworldedit.bukkit.adapter.DelegateSemaphore;
 import com.fastasyncworldedit.core.Fawe;
 import com.fastasyncworldedit.core.FaweCache;
 import com.fastasyncworldedit.core.configuration.Settings;
@@ -74,6 +73,7 @@ import java.util.Set;
 import java.util.UUID;
 import java.util.concurrent.Callable;
 import java.util.concurrent.Future;
+import java.util.concurrent.Semaphore;
 import java.util.concurrent.locks.ReadWriteLock;
 import java.util.concurrent.locks.ReentrantReadWriteLock;
 import java.util.function.Function;
@@ -505,7 +505,7 @@ public class PaperweightGetBlocks extends CharGetBlocks implements BukkitGetBloc
                         }
 
                         //ensure that the server doesn't try to tick the chunksection while we're editing it (again).
-                        DelegateSemaphore lock = PaperweightPlatformAdapter.applyLock(existingSection);
+                        Semaphore lock = PaperweightPlatformAdapter.applyLock(existingSection);
                         PaperweightPlatformAdapter.clearCounts(existingSection);
                         if (PaperLib.isPaper()) {
                             existingSection.tickingList.clear();
@@ -867,7 +867,7 @@ public class PaperweightGetBlocks extends CharGetBlocks implements BukkitGetBloc
             data = new char[4096];
             Arrays.fill(data, (char) BlockTypesCache.ReservedIDs.AIR);
         }
-        DelegateSemaphore lock = PaperweightPlatformAdapter.applyLock(section);
+        Semaphore lock = PaperweightPlatformAdapter.applyLock(section);
         synchronized (lock) {
             // Efficiently convert ChunkSection to raw data
             try {

worldedit-bukkit/adapters/adapter-1_17_1/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/fawe/v1_17_R1_2/PaperweightPlatformAdapter.java

@@ -30,6 +30,7 @@ import net.minecraft.server.level.ChunkMap;
 import net.minecraft.server.level.ServerLevel;
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.util.BitStorage;
+import net.minecraft.util.ThreadingDetector;
 import net.minecraft.world.level.ChunkPos;
 import net.minecraft.world.level.LevelAccessor;
 import net.minecraft.world.level.biome.Biome;
@@ -117,8 +118,15 @@ public final class PaperweightPlatformAdapter extends NMSAdapter {
             methodGetVisibleChunk = MethodHandles.lookup().unreflect(getVisibleChunkIfPresent);
 
             Unsafe unsafe = ReflectionUtils.getUnsafe();
-            fieldLock = PalettedContainer.class.getDeclaredField(Refraction.pickName("lock", "m"));
+            if (!PaperLib.isPaper()) {
+
+                fieldLock = ThreadingDetector.class.getDeclaredField(Refraction.pickName("lock", "m"));
                 fieldLockOffset = unsafe.objectFieldOffset(fieldLock);
+            } else {
+                // in paper, the used methods are synchronized properly
+                fieldLock = null;
+                fieldLockOffset = -1;
+            }
 
             fieldGameEventDispatcherSections = LevelChunk.class.getDeclaredField(Refraction.pickName(
                     "gameEventDispatcherSections", "x"));
@@ -162,8 +170,12 @@ public final class PaperweightPlatformAdapter extends NMSAdapter {
         return false;
     }
 
-    static DelegateSemaphore applyLock(LevelChunkSection section) {
+    private static final ThreadLocal<Semaphore> SEMAPHORE_THREAD_LOCAL = ThreadLocal.withInitial(() -> new Semaphore(1));
-        //todo there has to be a better way to do this. Maybe using a() in DataPaletteBlock which acquires the lock in NMS?
+
+    static Semaphore applyLock(LevelChunkSection section) {
+        if (PaperLib.isPaper()) {
+            return SEMAPHORE_THREAD_LOCAL.get();
+        }
         try {
             synchronized (section) {
                 Unsafe unsafe = ReflectionUtils.getUnsafe();

worldedit-bukkit/adapters/adapter-1_18/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/fawe/v1_18_R1/PaperweightGetBlocks.java

@@ -1,7 +1,6 @@
 package com.sk89q.worldedit.bukkit.adapter.impl.fawe.v1_18_R1;
 
 import com.fastasyncworldedit.bukkit.adapter.BukkitGetBlocks;
-import com.fastasyncworldedit.bukkit.adapter.DelegateSemaphore;
 import com.fastasyncworldedit.core.Fawe;
 import com.fastasyncworldedit.core.FaweCache;
 import com.fastasyncworldedit.core.configuration.Settings;
@@ -75,6 +74,7 @@ import java.util.Set;
 import java.util.UUID;
 import java.util.concurrent.Callable;
 import java.util.concurrent.Future;
+import java.util.concurrent.Semaphore;
 import java.util.concurrent.locks.ReadWriteLock;
 import java.util.concurrent.locks.ReentrantReadWriteLock;
 import java.util.function.Function;
@@ -560,7 +560,7 @@ public class PaperweightGetBlocks extends CharGetBlocks implements BukkitGetBloc
                         if (PaperLib.isPaper()) {
                             existingSection.tickingList.clear();
                         }
-                        DelegateSemaphore lock = PaperweightPlatformAdapter.applyLock(existingSection);
+                        Semaphore lock = PaperweightPlatformAdapter.applyLock(existingSection);
 
                         synchronized (lock) {
                             // lock.acquire();
@@ -895,7 +895,7 @@ public class PaperweightGetBlocks extends CharGetBlocks implements BukkitGetBloc
             data = new char[4096];
             Arrays.fill(data, (char) BlockTypesCache.ReservedIDs.AIR);
         }
-        DelegateSemaphore lock = PaperweightPlatformAdapter.applyLock(section);
+        Semaphore lock = PaperweightPlatformAdapter.applyLock(section);
         synchronized (lock) {
             // Efficiently convert ChunkSection to raw data
             try {

worldedit-bukkit/adapters/adapter-1_18/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/fawe/v1_18_R1/PaperweightPlatformAdapter.java

@@ -133,11 +133,20 @@ public final class PaperweightPlatformAdapter extends NMSAdapter {
             methodGetVisibleChunk = MethodHandles.lookup().unreflect(getVisibleChunkIfPresent);
 
             Unsafe unsafe = ReflectionUtils.getUnsafe();
+            if (!PaperLib.isPaper()) {
                 fieldThreadingDetector = PalettedContainer.class.getDeclaredField(Refraction.pickName("threadingDetector", "f"));
                 fieldThreadingDetectorOffset = unsafe.objectFieldOffset(fieldThreadingDetector);
 
                 fieldLock = ThreadingDetector.class.getDeclaredField(Refraction.pickName("lock", "c"));
                 fieldLockOffset = unsafe.objectFieldOffset(fieldLock);
+            } else {
+                // in paper, the used methods are synchronized properly
+                fieldThreadingDetector = null;
+                fieldThreadingDetectorOffset = -1;
+
+                fieldLock = null;
+                fieldLockOffset = -1;
+            }
 
             fieldGameEventDispatcherSections = LevelChunk.class.getDeclaredField(Refraction.pickName(
                     "gameEventDispatcherSections", "t"));
@@ -181,7 +190,12 @@ public final class PaperweightPlatformAdapter extends NMSAdapter {
         return false;
     }
 
-    static DelegateSemaphore applyLock(LevelChunkSection section) {
+    private static final ThreadLocal<Semaphore> SEMAPHORE_THREAD_LOCAL = ThreadLocal.withInitial(() -> new Semaphore(1));
+
+    static Semaphore applyLock(LevelChunkSection section) {
+        if (PaperLib.isPaper()) {
+            return SEMAPHORE_THREAD_LOCAL.get();
+        }
         try {
             synchronized (section) {
                 Unsafe unsafe = ReflectionUtils.getUnsafe();

worldedit-bukkit/adapters/adapter-1_18_2/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/fawe/v1_18_R2/PaperweightGetBlocks.java

@@ -1,7 +1,6 @@
 package com.sk89q.worldedit.bukkit.adapter.impl.fawe.v1_18_R2;
 
 import com.fastasyncworldedit.bukkit.adapter.BukkitGetBlocks;
-import com.fastasyncworldedit.bukkit.adapter.DelegateSemaphore;
 import com.fastasyncworldedit.core.Fawe;
 import com.fastasyncworldedit.core.FaweCache;
 import com.fastasyncworldedit.core.configuration.Settings;
@@ -76,6 +75,7 @@ import java.util.Set;
 import java.util.UUID;
 import java.util.concurrent.Callable;
 import java.util.concurrent.Future;
+import java.util.concurrent.Semaphore;
 import java.util.concurrent.locks.ReadWriteLock;
 import java.util.concurrent.locks.ReentrantReadWriteLock;
 import java.util.function.Function;
@@ -576,7 +576,7 @@ public class PaperweightGetBlocks extends CharGetBlocks implements BukkitGetBloc
                         if (PaperLib.isPaper()) {
                             existingSection.tickingList.clear();
                         }
-                        DelegateSemaphore lock = PaperweightPlatformAdapter.applyLock(existingSection);
+                        Semaphore lock = PaperweightPlatformAdapter.applyLock(existingSection);
 
                         synchronized (lock) {
                             // lock.acquire();
@@ -914,7 +914,7 @@ public class PaperweightGetBlocks extends CharGetBlocks implements BukkitGetBloc
             data = new char[4096];
             Arrays.fill(data, (char) BlockTypesCache.ReservedIDs.AIR);
         }
-        DelegateSemaphore lock = PaperweightPlatformAdapter.applyLock(section);
+        Semaphore lock = PaperweightPlatformAdapter.applyLock(section);
         synchronized (lock) {
             // Efficiently convert ChunkSection to raw data
             try {

worldedit-bukkit/adapters/adapter-1_18_2/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/fawe/v1_18_R2/PaperweightPlatformAdapter.java

@@ -132,11 +132,20 @@ public final class PaperweightPlatformAdapter extends NMSAdapter {
             methodGetVisibleChunk = MethodHandles.lookup().unreflect(getVisibleChunkIfPresent);
 
             Unsafe unsafe = ReflectionUtils.getUnsafe();
+            if (!PaperLib.isPaper()) {
                 fieldThreadingDetector = PalettedContainer.class.getDeclaredField(Refraction.pickName("threadingDetector", "f"));
                 fieldThreadingDetectorOffset = unsafe.objectFieldOffset(fieldThreadingDetector);
 
                 fieldLock = ThreadingDetector.class.getDeclaredField(Refraction.pickName("lock", "c"));
                 fieldLockOffset = unsafe.objectFieldOffset(fieldLock);
+            } else {
+                // in paper, the used methods are synchronized properly
+                fieldThreadingDetector = null;
+                fieldThreadingDetectorOffset = -1;
+
+                fieldLock = null;
+                fieldLockOffset = -1;
+            }
 
             fieldGameEventDispatcherSections = LevelChunk.class.getDeclaredField(Refraction.pickName(
                     "gameEventDispatcherSections", "t"));
@@ -180,7 +189,12 @@ public final class PaperweightPlatformAdapter extends NMSAdapter {
         return false;
     }
 
-    static DelegateSemaphore applyLock(LevelChunkSection section) {
+    private static final ThreadLocal<Semaphore> SEMAPHORE_THREAD_LOCAL = ThreadLocal.withInitial(() -> new Semaphore(1));
+
+    static Semaphore applyLock(LevelChunkSection section) {
+        if (PaperLib.isPaper()) {
+            return SEMAPHORE_THREAD_LOCAL.get();
+        }
         try {
             synchronized (section) {
                 Unsafe unsafe = ReflectionUtils.getUnsafe();
@@ -192,7 +206,7 @@ public final class PaperweightPlatformAdapter extends NMSAdapter {
                 synchronized (currentThreadingDetector) {
                     Semaphore currentLock = (Semaphore) unsafe.getObject(currentThreadingDetector, fieldLockOffset);
                     if (currentLock instanceof DelegateSemaphore) {
-                        return (DelegateSemaphore) currentLock;
+                        return currentLock;
                     }
                     DelegateSemaphore newLock = new DelegateSemaphore(1, currentLock);
                     unsafe.putObject(currentThreadingDetector, fieldLockOffset, newLock);