Only synchronise tree generation at the very lowest level (#1788)

* Only synchronise tree generation at the very lowest level
 - Fixes #1681

* Perform the generate inside try-finally and actually use the resultant copied map to place blocks to the editsession

* Check result of generateTree and return null if failed

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

@@ -10,6 +10,7 @@ import com.fastasyncworldedit.core.queue.IBatchProcessor;
 import com.fastasyncworldedit.core.queue.IChunkGet;
 import com.fastasyncworldedit.core.queue.implementation.packet.ChunkPacket;
 import com.fastasyncworldedit.core.util.NbtUtils;
+import com.fastasyncworldedit.core.util.TaskManager;
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
@@ -561,16 +562,26 @@ public final class PaperweightFaweAdapter extends CachedBukkitAdapter implements
             ); // bukkit skips the feature gen which does this offset normally, so we have to add it back
         }
         ServerLevel serverLevel = ((CraftWorld) bukkitWorld).getHandle();
+        final BlockVector3 finalBlockVector = blockVector3;
+        // Sync to main thread to ensure no clashes occur
+        Map<BlockPos, CraftBlockState> placed = TaskManager.taskManager().sync(() -> {
             serverLevel.captureTreeGeneration = true;
             serverLevel.captureBlockStates = true;
-        boolean grownTree = bukkitWorld.generateTree(BukkitAdapter.adapt(bukkitWorld, blockVector3), bukkitType);
+            try {
+                if (!bukkitWorld.generateTree(BukkitAdapter.adapt(bukkitWorld, finalBlockVector), bukkitType)) {
+                    return null;
+                }
+                return ImmutableMap.copyOf(serverLevel.capturedBlockStates);
+            } finally {
                 serverLevel.captureBlockStates = false;
                 serverLevel.captureTreeGeneration = false;
-        if (!grownTree) {
                 serverLevel.capturedBlockStates.clear();
+            }
+        });
+        if (placed == null || placed.isEmpty()) {
             return false;
-        } else {
+        }
-            for (CraftBlockState craftBlockState : serverLevel.capturedBlockStates.values()) {
+        for (CraftBlockState craftBlockState : placed.values()) {
             if (craftBlockState == null || craftBlockState.getType() == Material.AIR) {
                 continue;
             }
@@ -578,11 +589,8 @@ public final class PaperweightFaweAdapter extends CachedBukkitAdapter implements
                     BukkitAdapter.adapt(((org.bukkit.block.BlockState) craftBlockState).getBlockData())
             );
         }
-
-            serverLevel.capturedBlockStates.clear();
         return true;
     }
-    }
 
     @Override
     public List<org.bukkit.entity.Entity> getEntities(org.bukkit.World world) {

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

@@ -10,6 +10,7 @@ import com.fastasyncworldedit.core.queue.IBatchProcessor;
 import com.fastasyncworldedit.core.queue.IChunkGet;
 import com.fastasyncworldedit.core.queue.implementation.packet.ChunkPacket;
 import com.fastasyncworldedit.core.util.NbtUtils;
+import com.fastasyncworldedit.core.util.TaskManager;
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
@@ -553,16 +554,26 @@ public final class PaperweightFaweAdapter extends CachedBukkitAdapter implements
             ); // bukkit skips the feature gen which does this offset normally, so we have to add it back
         }
         ServerLevel serverLevel = ((CraftWorld) bukkitWorld).getHandle();
+        final BlockVector3 finalBlockVector = blockVector3;
+        // Sync to main thread to ensure no clashes occur
+        Map<BlockPos, CraftBlockState> placed = TaskManager.taskManager().sync(() -> {
             serverLevel.captureTreeGeneration = true;
             serverLevel.captureBlockStates = true;
-        boolean grownTree = bukkitWorld.generateTree(BukkitAdapter.adapt(bukkitWorld, blockVector3), bukkitType);
+            try {
+                if (!bukkitWorld.generateTree(BukkitAdapter.adapt(bukkitWorld, finalBlockVector), bukkitType)) {
+                    return null;
+                }
+                return ImmutableMap.copyOf(serverLevel.capturedBlockStates);
+            } finally {
                 serverLevel.captureBlockStates = false;
                 serverLevel.captureTreeGeneration = false;
-        if (!grownTree) {
                 serverLevel.capturedBlockStates.clear();
+            }
+        });
+        if (placed == null || placed.isEmpty()) {
             return false;
-        } else {
+        }
-            for (CraftBlockState craftBlockState : serverLevel.capturedBlockStates.values()) {
+        for (CraftBlockState craftBlockState : placed.values()) {
             if (craftBlockState == null || craftBlockState.getType() == Material.AIR) {
                 continue;
             }
@@ -570,11 +581,8 @@ public final class PaperweightFaweAdapter extends CachedBukkitAdapter implements
                     BukkitAdapter.adapt(((org.bukkit.block.BlockState) craftBlockState).getBlockData())
             );
         }
-
-            serverLevel.capturedBlockStates.clear();
         return true;
     }
-    }
 
     @Override
     public List<org.bukkit.entity.Entity> getEntities(org.bukkit.World world) {

worldedit-bukkit/adapters/adapter-1_19/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/fawe/v1_19_R1/PaperweightFaweAdapter.java

@@ -10,6 +10,7 @@ import com.fastasyncworldedit.core.queue.IBatchProcessor;
 import com.fastasyncworldedit.core.queue.IChunkGet;
 import com.fastasyncworldedit.core.queue.implementation.packet.ChunkPacket;
 import com.fastasyncworldedit.core.util.NbtUtils;
+import com.fastasyncworldedit.core.util.TaskManager;
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
@@ -554,16 +555,26 @@ public final class PaperweightFaweAdapter extends CachedBukkitAdapter implements
             ); // bukkit skips the feature gen which does this offset normally, so we have to add it back
         }
         ServerLevel serverLevel = ((CraftWorld) bukkitWorld).getHandle();
+        final BlockVector3 finalBlockVector = blockVector3;
+        // Sync to main thread to ensure no clashes occur
+        Map<BlockPos, CraftBlockState> placed = TaskManager.taskManager().sync(() -> {
             serverLevel.captureTreeGeneration = true;
             serverLevel.captureBlockStates = true;
-        boolean grownTree = bukkitWorld.generateTree(BukkitAdapter.adapt(bukkitWorld, blockVector3), bukkitType);
+            try {
+                if (!bukkitWorld.generateTree(BukkitAdapter.adapt(bukkitWorld, finalBlockVector), bukkitType)) {
+                    return null;
+                }
+                return ImmutableMap.copyOf(serverLevel.capturedBlockStates);
+            } finally {
                 serverLevel.captureBlockStates = false;
                 serverLevel.captureTreeGeneration = false;
-        if (!grownTree) {
                 serverLevel.capturedBlockStates.clear();
+            }
+        });
+        if (placed == null || placed.isEmpty()) {
             return false;
-        } else {
+        }
-            for (CraftBlockState craftBlockState : serverLevel.capturedBlockStates.values()) {
+        for (CraftBlockState craftBlockState : placed.values()) {
             if (craftBlockState == null || craftBlockState.getType() == Material.AIR) {
                 continue;
             }
@@ -571,11 +582,8 @@ public final class PaperweightFaweAdapter extends CachedBukkitAdapter implements
                     BukkitAdapter.adapt(((org.bukkit.block.BlockState) craftBlockState).getBlockData())
             );
         }
-
-            serverLevel.capturedBlockStates.clear();
         return true;
     }
-    }
 
     @Override
     public List<org.bukkit.entity.Entity> getEntities(org.bukkit.World world) {

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

@@ -24,7 +24,6 @@ import com.fastasyncworldedit.core.Fawe;
 import com.fastasyncworldedit.core.internal.exception.FaweException;
 import com.fastasyncworldedit.core.queue.IChunkGet;
 import com.fastasyncworldedit.core.queue.implementation.packet.ChunkPacket;
-import com.fastasyncworldedit.core.util.TaskManager;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Sets;
 import com.sk89q.jnbt.CompoundTag;
@@ -334,9 +333,7 @@ public class BukkitWorld extends AbstractWorld {
     @Override
     public boolean generateTree(TreeGenerator.TreeType type, EditSession editSession, BlockVector3 pt) {
         //FAWE start - allow tree commands to be undone and obey region restrictions
-        return TaskManager.taskManager().sync(() -> WorldEditPlugin.getInstance().getBukkitImplAdapter().generateTree(type, editSession, pt,
+        return WorldEditPlugin.getInstance().getBukkitImplAdapter().generateTree(type, editSession, pt, getWorld());
-                getWorld()
-        ));
         //FAWE end
     }
 

worldedit-core/src/main/java/com/fastasyncworldedit/core/FaweAPI.java

@@ -77,7 +77,7 @@ public class FaweAPI {
      * </p>
      *
      * @param world     The name of the world
-     * @param autoQueue If it should start dispatching before you enqueue it.
+     * @param autoQueue If it should start dispatching before you close/flush it.
      * @return the queue extent
      */
     public static IQueueExtent<IQueueChunk> createQueue(World world, boolean autoQueue) {

worldedit-core/src/main/java/com/fastasyncworldedit/core/wrappers/WorldWrapper.java

@@ -273,13 +273,11 @@ public class WorldWrapper extends AbstractWorld {
     @Override
     public boolean generateTree(TreeGenerator.TreeType type, EditSession editSession, BlockVector3 position) throws
             MaxChangedBlocksException {
-        return TaskManager.taskManager().sync(() -> {
         try {
             return parent.generateTree(type, editSession, position);
         } catch (MaxChangedBlocksException e) {
             throw new RuntimeException(e);
         }
-        });
     }
 
     @Override