Initial watchdog setup. Bukkit needs adapters, everything needs testing.

worldedit-core/src/main/java/com/sk89q/worldedit/EditSession.java

@@ -22,6 +22,8 @@ package com.sk89q.worldedit;
 import com.sk89q.worldedit.entity.BaseEntity;
 import com.sk89q.worldedit.entity.Entity;
 import com.sk89q.worldedit.event.extent.EditSessionEvent;
+import com.sk89q.worldedit.extension.platform.Capability;
+import com.sk89q.worldedit.extension.platform.Watchdog;
 import com.sk89q.worldedit.extent.ChangeSetExtent;
 import com.sk89q.worldedit.extent.Extent;
 import com.sk89q.worldedit.extent.MaskingExtent;
@@ -38,6 +40,7 @@ import com.sk89q.worldedit.extent.world.BlockQuirkExtent;
 import com.sk89q.worldedit.extent.world.ChunkLoadingExtent;
 import com.sk89q.worldedit.extent.world.FastModeExtent;
 import com.sk89q.worldedit.extent.world.SurvivalModeExtent;
+import com.sk89q.worldedit.extent.world.WatchdogTickingExtent;
 import com.sk89q.worldedit.function.GroundFunction;
 import com.sk89q.worldedit.function.RegionMaskingFilter;
 import com.sk89q.worldedit.function.biome.BiomeReplace;
@@ -214,10 +217,16 @@ public class EditSession implements Extent, AutoCloseable {
         this.world = world;
 
         if (world != null) {
+            Watchdog watchdog = WorldEdit.getInstance().getPlatformManager()
+                .queryCapability(Capability.GAME_HOOKS).getWatchdog();
             Extent extent;
 
             // These extents are ALWAYS used
             extent = fastModeExtent = new FastModeExtent(world, false);
+            if (watchdog != null) {
+                // Reset watchdog before world placement
+                extent = new WatchdogTickingExtent(extent, watchdog);
+            }
             extent = survivalExtent = new SurvivalModeExtent(extent, world);
             extent = new BlockQuirkExtent(extent, world);
             extent = new ChunkLoadingExtent(extent, world);
@@ -230,6 +239,11 @@ public class EditSession implements Extent, AutoCloseable {
             extent = reorderExtent = new MultiStageReorder(extent, false);
             extent = chunkBatchingExtent = new ChunkBatchingExtent(extent);
             extent = wrapExtent(extent, eventBus, event, Stage.BEFORE_REORDER);
+            if (watchdog != null) {
+                // reset before buffering extents, since they may buffer all changes
+                // before the world-placement reset can happen, and still cause halts
+                extent = new WatchdogTickingExtent(extent, watchdog);
+            }
             this.bypassHistory = new DataValidatorExtent(extent, world);
 
             // These extents can be skipped by calling smartSetBlock()

worldedit-core/src/main/java/com/sk89q/worldedit/extension/platform/Platform.java

@@ -83,6 +83,15 @@ public interface Platform {
      */
     int schedule(long delay, long period, Runnable task);
 
+    /**
+     * Get the watchdog service.
+     *
+     * @return the watchdog service, or {@code null} if none
+     */
+    default @Nullable Watchdog getWatchdog() {
+        return null;
+    }
+
     /**
      * Get a list of available or loaded worlds.
      *

worldedit-core/src/main/java/com/sk89q/worldedit/extension/platform/Watchdog.java

@@ -0,0 +1,29 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.extension.platform;
+
+/**
+ * Interface to a {@link Platform}'s watchdog service.
+ */
+public interface Watchdog {
+
+    void tick();
+
+}

worldedit-core/src/main/java/com/sk89q/worldedit/extent/world/WatchdogTickingExtent.java

@@ -0,0 +1,72 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.extent.world;
+
+import com.sk89q.worldedit.WorldEditException;
+import com.sk89q.worldedit.entity.BaseEntity;
+import com.sk89q.worldedit.entity.Entity;
+import com.sk89q.worldedit.extension.platform.Watchdog;
+import com.sk89q.worldedit.extent.AbstractDelegateExtent;
+import com.sk89q.worldedit.extent.Extent;
+import com.sk89q.worldedit.math.BlockVector2;
+import com.sk89q.worldedit.math.BlockVector3;
+import com.sk89q.worldedit.util.Location;
+import com.sk89q.worldedit.world.biome.BiomeType;
+import com.sk89q.worldedit.world.block.BlockStateHolder;
+
+import javax.annotation.Nullable;
+
+/**
+ * Extent that ticks the watchdog before every world-affecting action.
+ */
+public class WatchdogTickingExtent extends AbstractDelegateExtent {
+
+    private final Watchdog watchdog;
+
+    /**
+     * Create a new instance.
+     *
+     * @param extent the extent
+     * @param watchdog the watchdog to reset
+     */
+    public WatchdogTickingExtent(Extent extent, Watchdog watchdog) {
+        super(extent);
+        this.watchdog = watchdog;
+    }
+
+    @Override
+    public <T extends BlockStateHolder<T>> boolean setBlock(BlockVector3 location, T block) throws WorldEditException {
+        watchdog.tick();
+        return super.setBlock(location, block);
+    }
+
+    @Nullable
+    @Override
+    public Entity createEntity(Location location, BaseEntity entity) {
+        watchdog.tick();
+        return super.createEntity(location, entity);
+    }
+
+    @Override
+    public boolean setBiome(BlockVector2 position, BiomeType biome) {
+        watchdog.tick();
+        return super.setBiome(position, biome);
+    }
+}