Minor code quality changes

Changed Lock to subclass ReentrantLock since that is the only subclass DelegateLock should be using. The lock should also never be null so I added an annotation in the constructor.
I also removed some code and replaced it with PaperLib code to just clean up things a little bit.

worldedit-bukkit/src/main/java/com/boydti/fawe/bukkit/adapter/DelegateLock.java

@@ -7,19 +7,16 @@ import java.util.concurrent.atomic.AtomicInteger;
 import java.util.concurrent.locks.Condition;
 import java.util.concurrent.locks.Lock;
 import java.util.concurrent.locks.ReentrantLock;
+import org.jetbrains.annotations.NotNull;
 
 public class DelegateLock extends ReentrantLockWithGetOwner {
-    private final Lock parent;
+    private final ReentrantLock parent;
     private volatile boolean modified;
     private final AtomicInteger count;
 
-    public DelegateLock(Lock parent) {
+    public DelegateLock(@NotNull ReentrantLock parent) {
         this.parent = parent;
-        if (!(parent instanceof ReentrantLock)) {
-            count = new AtomicInteger();
-        } else {
-            count = null;
-        }
+        this.count = null;
     }
 
     public boolean isModified() {
@@ -86,22 +83,15 @@ public class DelegateLock extends ReentrantLockWithGetOwner {
 
     @Override
     public synchronized boolean isLocked() {
-        if (parent instanceof ReentrantLock) {
-            return ((ReentrantLock) parent).isLocked();
-        }
-        return count.get() > 0;
+        return parent.isLocked();
     }
 
     public void untilFree() {
-        if (parent instanceof ReentrantLock) {
-            ReentrantLock rl = (ReentrantLock) parent;
-            if (rl.isLocked()) {
-                rl.lock();
-                rl.unlock();
-            }
-            return;
+        ReentrantLock rl = parent;
+        if (rl.isLocked()) {
+            rl.lock();
+            rl.unlock();
         }
-        while (count.get() > 0);
     }
 
     @Override

worldedit-bukkit/src/main/java/com/boydti/fawe/bukkit/adapter/mc1_14/BukkitAdapter_1_14.java

@@ -12,6 +12,7 @@ import com.boydti.fawe.util.TaskManager;
 import com.sk89q.worldedit.world.block.BlockState;
 import com.sk89q.worldedit.world.block.BlockTypesCache;
 import io.papermc.lib.PaperLib;
+import java.util.concurrent.locks.ReentrantLock;
 import net.jpountz.util.UnsafeUtils;
 import net.minecraft.server.v1_14_R1.Block;
 import net.minecraft.server.v1_14_R1.Chunk;
@@ -115,7 +116,7 @@ public final class BukkitAdapter_1_14 extends NMSAdapter {
         try {
             synchronized (section) {
                 DataPaletteBlock<IBlockData> blocks = section.getBlocks();
-                Lock currentLock = (Lock) fieldLock.get(blocks);
+                ReentrantLock currentLock = (ReentrantLock) fieldLock.get(blocks);
                 if (currentLock instanceof DelegateLock) {
                     return (DelegateLock) currentLock;
                 }

worldedit-bukkit/src/main/java/com/boydti/fawe/bukkit/adapter/mc1_15/BukkitAdapter_1_15.java

@@ -12,6 +12,7 @@ import com.boydti.fawe.util.TaskManager;
 import com.sk89q.worldedit.world.block.BlockState;
 import com.sk89q.worldedit.world.block.BlockTypesCache;
 import io.papermc.lib.PaperLib;
+import java.util.concurrent.locks.ReentrantLock;
 import net.jpountz.util.UnsafeUtils;
 import net.minecraft.server.v1_15_R1.*;
 import org.bukkit.craftbukkit.v1_15_R1.CraftChunk;
@@ -96,7 +97,7 @@ public final class BukkitAdapter_1_15 extends NMSAdapter {
         try {
             synchronized (section) {
                 DataPaletteBlock<IBlockData> blocks = section.getBlocks();
-                Lock currentLock = (Lock) fieldLock.get(blocks);
+                ReentrantLock currentLock = (ReentrantLock) fieldLock.get(blocks);
                 if (currentLock instanceof DelegateLock) {
                     return (DelegateLock) currentLock;
                 }

worldedit-bukkit/src/main/java/com/boydti/fawe/bukkit/adapter/mc1_15_2/BukkitAdapter_1_15_2.java

@@ -12,6 +12,7 @@ import com.boydti.fawe.util.TaskManager;
 import com.sk89q.worldedit.world.block.BlockState;
 import com.sk89q.worldedit.world.block.BlockTypesCache;
 import io.papermc.lib.PaperLib;
+import java.util.concurrent.locks.ReentrantLock;
 import net.jpountz.util.UnsafeUtils;
 import net.minecraft.server.v1_15_R1.*;
 import org.bukkit.craftbukkit.v1_15_R1.CraftChunk;
@@ -93,10 +94,11 @@ public final class BukkitAdapter_1_15_2 extends NMSAdapter {
     }
 
     protected static DelegateLock applyLock(ChunkSection section) {
+        //todo there has to be a better way to do this. Maybe using a() in DataPaletteBlock which aquires the lock in NMS?
         try {
             synchronized (section) {
                 DataPaletteBlock<IBlockData> blocks = section.getBlocks();
-                Lock currentLock = (Lock) fieldLock.get(blocks);
+                ReentrantLock currentLock = (ReentrantLock) fieldLock.get(blocks);
                 if (currentLock instanceof DelegateLock) {
                     return (DelegateLock) currentLock;
                 }

worldedit-bukkit/src/main/java/com/sk89q/worldedit/bukkit/BukkitWorld.java

@@ -342,13 +342,7 @@ public class BukkitWorld extends AbstractWorld {
 	        if (Fawe.isMainThread()) {
 	            world.getChunkAt(X, Z);
 	        } else if (!world.isChunkLoaded(X, Z)) {
-	            if (PaperLib.isPaper()) {
-	                world.getChunkAtAsync(X, Z, true);
-	            } else {
-	                Fawe.get().getQueueHandler().sync(() -> {
-	                    world.getChunkAt(X, Z);
-	                });
-	            }
+	            PaperLib.getChunkAtAsync(world,X, Z, true);
 	        }
 		}
     }