diff --git a/camellia-server/src/main/java/com/ishland/c2me/base/common/scheduler/AbstractPosAwarePrioritizedTask.java b/camellia-server/src/main/java/com/ishland/c2me/base/common/scheduler/AbstractPosAwarePrioritizedTask.java
new file mode 100644
index 0000000..8cdc25b
--- /dev/null
+++ b/camellia-server/src/main/java/com/ishland/c2me/base/common/scheduler/AbstractPosAwarePrioritizedTask.java
@@ -0,0 +1,50 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2021-2026 ishland
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.ishland.c2me.base.common.scheduler;
+
+import com.ishland.flowsched.executor.Task;
+import it.unimi.dsi.fastutil.objects.ReferenceArrayList;
+
+import java.util.Objects;
+
+public abstract class AbstractPosAwarePrioritizedTask extends Task {
+
+    protected final ReferenceArrayList<Runnable> postExec = new ReferenceArrayList<>(4);
+    private final long pos;
+
+    public AbstractPosAwarePrioritizedTask(long pos) {
+        this.pos = pos;
+    }
+
+    public long getPos() {
+        return this.pos;
+    }
+
+    public void addPostExec(Runnable runnable) {
+        synchronized (this.postExec) {
+            postExec.add(Objects.requireNonNull(runnable));
+        }
+    }
+}
diff --git a/camellia-server/src/main/java/com/ishland/c2me/base/common/scheduler/LockTokenImpl.java b/camellia-server/src/main/java/com/ishland/c2me/base/common/scheduler/LockTokenImpl.java
new file mode 100644
index 0000000..84b294a
--- /dev/null
+++ b/camellia-server/src/main/java/com/ishland/c2me/base/common/scheduler/LockTokenImpl.java
@@ -0,0 +1,90 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2021-2026 ishland
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.ishland.c2me.base.common.scheduler;
+
+import com.ishland.flowsched.executor.LockToken;
+
+import java.util.Objects;
+
+public final class LockTokenImpl implements LockToken {
+    private final int ownerTag;
+    private final long pos;
+    private final Usage usage;
+
+    public LockTokenImpl(int ownerTag, long pos, Usage usage) {
+        this.ownerTag = ownerTag;
+        this.pos = pos;
+        this.usage = usage;
+    }
+
+    public int ownerTag() {
+        return ownerTag;
+    }
+
+    public long pos() {
+        return pos;
+    }
+
+    public Usage usage() {
+        return usage;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (obj == this) return true;
+        if (obj == null || obj.getClass() != this.getClass()) return false;
+        var that = (LockTokenImpl) obj;
+        return this.ownerTag == that.ownerTag &&
+               this.pos == that.pos &&
+               Objects.equals(this.usage, that.usage);
+    }
+
+    @Override
+    public int hashCode() {
+        // inlined Objects.hash(ownerTag, usage, pos)
+        int result = 1;
+
+        result = 31 * result + Integer.hashCode(ownerTag);
+        result = 31 * result + usage.hashCode();
+        result = 31 * result + Long.hashCode(pos);
+
+        return result;
+    }
+
+    @Override
+    public String toString() {
+        return "LockTokenImpl[" +
+               "ownerTag=" + ownerTag + ", " +
+               "pos=" + pos + ", " +
+               "usage=" + usage + ']';
+    }
+
+
+    public enum Usage {
+        WORLDGEN,
+        LIGHTING,
+    }
+
+}
diff --git a/camellia-server/src/main/java/com/ishland/c2me/base/common/scheduler/ScheduledTask.java b/camellia-server/src/main/java/com/ishland/c2me/base/common/scheduler/ScheduledTask.java
new file mode 100644
index 0000000..85b8434
--- /dev/null
+++ b/camellia-server/src/main/java/com/ishland/c2me/base/common/scheduler/ScheduledTask.java
@@ -0,0 +1,76 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2021-2026 ishland
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.ishland.c2me.base.common.scheduler;
+
+import com.ishland.flowsched.executor.LockToken;
+
+import java.util.concurrent.CompletableFuture;
+import java.util.function.Supplier;
+
+public class ScheduledTask<T> extends AbstractPosAwarePrioritizedTask {
+
+    private final Supplier<CompletableFuture<T>> action;
+    private final LockToken[] lockTokens;
+    private final CompletableFuture<T> future = new CompletableFuture<>();
+
+    public ScheduledTask(long pos, Supplier<CompletableFuture<T>> action, LockToken[] lockTokens) {
+        super(pos);
+        this.action = action;
+        this.lockTokens = lockTokens;
+    }
+
+    @Override
+    public void run(Runnable releaseLocks) {
+        action.get().whenComplete((t, throwable) -> {
+            releaseLocks.run();
+            if (throwable != null) {
+                future.completeExceptionally(throwable);
+            } else {
+                future.complete(t);
+            }
+            for (Runnable runnable : this.postExec) {
+                try {
+                    runnable.run();
+                } catch (Throwable t1) {
+                    t1.printStackTrace();
+                }
+            }
+        });
+    }
+
+    @Override
+    public void propagateException(Throwable t) {
+        future.completeExceptionally(t);
+    }
+
+    @Override
+    public LockToken[] lockTokens() {
+        return this.lockTokens;
+    }
+
+    public CompletableFuture<T> getFuture() {
+        return this.future;
+    }
+}
diff --git a/camellia-server/src/main/java/com/ishland/c2me/base/common/scheduler/SchedulingManager.java b/camellia-server/src/main/java/com/ishland/c2me/base/common/scheduler/SchedulingManager.java
new file mode 100644
index 0000000..f5ccdc2
--- /dev/null
+++ b/camellia-server/src/main/java/com/ishland/c2me/base/common/scheduler/SchedulingManager.java
@@ -0,0 +1,266 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2021-2026 ishland
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.ishland.c2me.base.common.scheduler;
+
+import com.ishland.c2me.base.common.GlobalExecutors;
+import com.ishland.flowsched.executor.ExecutorManager;
+import it.unimi.dsi.fastutil.longs.Long2IntOpenHashMap;
+import it.unimi.dsi.fastutil.objects.ObjectArraySet;
+import net.minecraft.server.level.ChunkLevel;
+import net.minecraft.world.level.ChunkPos;
+
+import java.util.ArrayDeque;
+import java.util.Queue;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+import java.util.concurrent.Executor;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.locks.StampedLock;
+
+public class SchedulingManager {
+
+    private static final AtomicInteger COUNTER = new AtomicInteger(0);
+
+    public static final int MAX_LEVEL = ChunkLevel.MAX_LEVEL + 1;
+    private final ConcurrentMap<Long, FreeableTaskList> pos2Tasks = new ConcurrentHashMap<>();
+    private final Long2IntOpenHashMap prioritiesFromLevel = new Long2IntOpenHashMap() {
+        @Override
+        protected void rehash(int newN) {
+            if (n < newN) {
+                super.rehash(newN);
+            }
+        }
+    };
+    private final StampedLock prioritiesLock = new StampedLock();
+    private final int id = COUNTER.getAndIncrement();
+    private volatile ChunkPos currentSyncLoad = null;
+
+    private boolean consolidatingLevelUpdates = false;
+    private Queue<Runnable> consolidatedLevelUpdates = new ArrayDeque<>();
+
+    private final Executor executor;
+
+    {
+        prioritiesFromLevel.defaultReturnValue(MAX_LEVEL);
+    }
+    private final ExecutorManager worker;
+
+    public SchedulingManager(Executor managementExecutor, ExecutorManager worker) {
+        this.executor = managementExecutor;
+        this.worker = worker;
+    }
+
+    public void enqueue(AbstractPosAwarePrioritizedTask task) {
+        retry:
+        while (true) {
+            final long pos = task.getPos();
+            final FreeableTaskList locks = this.pos2Tasks.computeIfAbsent(pos, unused -> new FreeableTaskList());
+            synchronized (locks) {
+                if (locks.freed) continue retry;
+                locks.add(task);
+            }
+            int priority = this.getPriority(pos);
+            task.addPostExec(() -> {
+                final FreeableTaskList tasks = this.pos2Tasks.get(task.getPos());
+                if (tasks != null) {
+                    synchronized (tasks) {
+                        if (tasks.freed) return;
+                        tasks.remove(task);
+                        if (tasks.isEmpty()) {
+                            tasks.freed = true;
+                        }
+                    }
+                    if (tasks.freed) {
+                        this.pos2Tasks.remove(task.getPos());
+                    }
+                }
+            });
+            this.worker.schedule(task, priority);
+            return;
+        }
+    }
+
+    public void enqueue(long pos, Runnable command) {
+        this.enqueue(new WrappingTask(pos, command));
+    }
+
+    public Executor positionedExecutor(long pos) {
+        return command -> this.enqueue(pos, command);
+    }
+
+    public void updatePriorityFromLevel(long pos, int level) {
+        this.executor.execute(() -> {
+            updatePriorityFromLevel0(pos, level);
+        });
+    }
+
+    private void updatePriorityFromLevel0(long pos, int level) {
+        if (this.getPriorityFromMap(pos) == level) return;
+        final long stamp = this.prioritiesLock.writeLock();
+        try {
+            if (level < MAX_LEVEL) {
+                this.prioritiesFromLevel.put(pos, level);
+            } else {
+                this.prioritiesFromLevel.remove(pos);
+            }
+        } finally {
+            this.prioritiesLock.unlockWrite(stamp);
+        }
+        updatePriorityInternal(pos);
+    }
+
+    public void updatePriorityFromLevelOnMain(long pos, int level) {
+        if (this.consolidatingLevelUpdates) {
+            this.consolidatedLevelUpdates.add(() -> updatePriorityFromLevel0(pos, level));
+        } else {
+            updatePriorityFromLevel(pos, level);
+        }
+    }
+
+    public void setConsolidatingLevelUpdates(boolean value) {
+        this.consolidatingLevelUpdates = value;
+        if (!value) {
+            if (!this.consolidatedLevelUpdates.isEmpty()) {
+                Queue<Runnable> runnables = this.consolidatedLevelUpdates;
+                this.consolidatedLevelUpdates = new ArrayDeque<>();
+                this.executor.execute(() -> {
+                    for (Runnable runnable : runnables) {
+                        try {
+                            runnable.run();
+                        } catch (Throwable t) {
+                            t.printStackTrace();
+                        }
+                    }
+                });
+            }
+        }
+    }
+
+    private void updatePriorityInternal(long pos) {
+        final int priority = getPriority(pos);
+        final FreeableTaskList locks = this.pos2Tasks.get(pos);
+        if (locks != null) {
+            synchronized (locks) {
+                if (locks.freed) return;
+                for (AbstractPosAwarePrioritizedTask lock : locks) {
+                    this.worker.changePriority(lock, priority);
+                }
+            }
+        }
+    }
+
+    public ExecutorManager getWorker() {
+        return this.worker;
+    }
+
+    private int getPriority(long pos) {
+        final int fromLevel = getPriorityFromMap(pos);
+        int fromSyncLoad;
+        ChunkPos currentSyncLoad1 = currentSyncLoad;
+        if (currentSyncLoad1 != null) {
+            final int chebyshevDistance = chebyshev(ChunkPos.unpack(pos), currentSyncLoad1);
+            if (chebyshevDistance <= 8) {
+                fromSyncLoad = chebyshevDistance;
+//                System.out.println("dist for chunk [%d,%d] is %d".formatted(currentSyncLoad.x, currentSyncLoad.z, chebyshevDistance));
+            } else {
+                fromSyncLoad = MAX_LEVEL;
+            }
+        } else {
+            fromSyncLoad = MAX_LEVEL;
+        }
+        return Math.min(fromLevel, fromSyncLoad);
+    }
+
+    private int getPriorityFromMap(long pos) {
+        int fromLevel = MAX_LEVEL;
+        long stamp = this.prioritiesLock.tryOptimisticRead();
+        try {
+            fromLevel = this.prioritiesFromLevel.get(pos);
+        } catch (Throwable t) {
+        }
+        if (!this.prioritiesLock.validate(stamp)) {
+            stamp = this.prioritiesLock.readLock();
+            try {
+                fromLevel = this.prioritiesFromLevel.get(pos);
+            } finally {
+                this.prioritiesLock.unlockRead(stamp);
+            }
+        }
+        return fromLevel;
+    }
+
+    public void setCurrentSyncLoad(ChunkPos pos) {
+        executor.execute(() -> {
+            if (this.currentSyncLoad != null) {
+                final ChunkPos lastSyncLoad = this.currentSyncLoad;
+                this.currentSyncLoad = null;
+                updateSyncLoadInternal(lastSyncLoad);
+            }
+            if (pos != null) {
+                this.currentSyncLoad = pos;
+                updateSyncLoadInternal(pos);
+            }
+        });
+    }
+
+    public int getId() {
+        return this.id;
+    }
+
+    private void updateSyncLoadInternal(ChunkPos pos) {
+        long startTime = System.nanoTime();
+        for (int xOff = -8; xOff <= 8; xOff++) {
+            for (int zOff = -8; zOff <= 8; zOff++) {
+                updatePriorityInternal(ChunkPos.pack(pos.x() + xOff, pos.z() + zOff));
+            }
+        }
+        long endTime = System.nanoTime();
+    }
+
+    private static int chebyshev(ChunkPos a, ChunkPos b) {
+        return Math.max(Math.abs(a.x() - b.x()), Math.abs(a.z() - b.z()));
+    }
+
+    private static int chebyshev(long a, long b) {
+        return Math.max(Math.abs(ChunkPos.getX(a) - ChunkPos.getX(b)), Math.abs(ChunkPos.getZ(a) - ChunkPos.getZ(b)));
+    }
+
+    private static class FreeableTaskList extends ObjectArraySet<AbstractPosAwarePrioritizedTask> {
+
+        private boolean freed = false;
+
+        @Override
+        public boolean equals(Object o) {
+            return this == o;
+        }
+
+        @Override
+        public int hashCode() {
+            return System.identityHashCode(this);
+        }
+
+    }
+
+}
diff --git a/camellia-server/src/main/java/com/ishland/c2me/base/common/scheduler/SimplePrioritizedTask.java b/camellia-server/src/main/java/com/ishland/c2me/base/common/scheduler/SimplePrioritizedTask.java
new file mode 100644
index 0000000..7c0836d
--- /dev/null
+++ b/camellia-server/src/main/java/com/ishland/c2me/base/common/scheduler/SimplePrioritizedTask.java
@@ -0,0 +1,60 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2021-2026 ishland
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.ishland.c2me.base.common.scheduler;
+
+import com.ishland.flowsched.executor.LockToken;
+import com.ishland.flowsched.executor.Task;
+
+import java.util.Objects;
+
+public class SimplePrioritizedTask extends Task {
+
+    private final Runnable task;
+    private final LockToken[] lockTokens;
+
+    public SimplePrioritizedTask(Runnable task, LockToken[] lockTokens) {
+        this.task = Objects.requireNonNull(task, "task");
+        this.lockTokens = Objects.requireNonNull(lockTokens, "lockTokens");
+    }
+
+    @Override
+    public void run(Runnable releaseLocks) {
+        try {
+            this.task.run();
+        } finally {
+            releaseLocks.run();
+        }
+    }
+
+    @Override
+    public void propagateException(Throwable t) {
+        t.printStackTrace();
+    }
+
+    @Override
+    public LockToken[] lockTokens() {
+        return this.lockTokens;
+    }
+}
diff --git a/camellia-server/src/main/java/com/ishland/c2me/base/common/scheduler/SingleThreadExecutor.java b/camellia-server/src/main/java/com/ishland/c2me/base/common/scheduler/SingleThreadExecutor.java
new file mode 100644
index 0000000..eb731be
--- /dev/null
+++ b/camellia-server/src/main/java/com/ishland/c2me/base/common/scheduler/SingleThreadExecutor.java
@@ -0,0 +1,107 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2021-2026 ishland
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.ishland.c2me.base.common.scheduler;
+
+import com.google.common.base.Preconditions;
+import io.netty.util.internal.PlatformDependent;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.Queue;
+import java.util.concurrent.Executor;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.locks.LockSupport;
+
+public class SingleThreadExecutor extends Thread implements Executor {
+
+    private final AtomicInteger size = new AtomicInteger();
+    public final Queue<Runnable> queue = PlatformDependent.newMpscQueue();
+    private final AtomicBoolean shutdown = new AtomicBoolean(false);
+    private final Object sync = new Object();
+
+    @Override
+    public void run() {
+        main_loop:
+        while (true) {
+            if (pollTasks()) {
+                continue;
+            }
+            if (this.shutdown.get()) {
+                return;
+            }
+
+//            // attempt to spin-wait before sleeping
+//            if (!pollTasks()) {
+//                Thread.interrupted(); // clear interrupt flag
+//                for (int i = 0; i < 5000; i ++) {
+//                    if (pollTasks()) continue main_loop;
+//                    LockSupport.parkNanos("Spin-waiting for tasks", 10_000); // 100us
+//                }
+//            }
+
+            synchronized (sync) {
+                if (this.size.get() != 0 || this.shutdown.get()) continue main_loop;
+                try {
+                    sync.wait();
+                } catch (InterruptedException ignored) {
+                }
+            }
+        }
+    }
+
+    private boolean pollTasks() {
+        boolean hasWork = false;
+        Runnable task;
+        while ((task = queue.poll()) != null) {
+            this.size.decrementAndGet();
+            try {
+                task.run();
+            } catch (Throwable t) {
+                t.printStackTrace();
+            }
+            hasWork = true;
+        }
+        return hasWork;
+    }
+
+    @Override
+    public void execute(@NotNull Runnable command) {
+        Preconditions.checkNotNull(command, "command");
+        final boolean wasEmpty = this.size.getAndIncrement() == 0;
+        this.queue.add(command);
+        if (wasEmpty) {
+            synchronized (sync) {
+                sync.notify();
+            }
+        }
+    }
+
+    public void shutdown() {
+        this.shutdown.set(true);
+        synchronized (sync) {
+            sync.notify();
+        }
+    }
+}
diff --git a/camellia-server/src/main/java/com/ishland/c2me/base/common/scheduler/ThreadLocalWorldGenSchedulingState.java b/camellia-server/src/main/java/com/ishland/c2me/base/common/scheduler/ThreadLocalWorldGenSchedulingState.java
new file mode 100644
index 0000000..66d3620
--- /dev/null
+++ b/camellia-server/src/main/java/com/ishland/c2me/base/common/scheduler/ThreadLocalWorldGenSchedulingState.java
@@ -0,0 +1,45 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2021-2026 ishland
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.ishland.c2me.base.common.scheduler;
+
+import net.minecraft.server.world.ChunkHolder;
+
+public class ThreadLocalWorldGenSchedulingState {
+
+    private static final ThreadLocal<ChunkHolder> chunkHolder = new ThreadLocal<>();
+
+    public static ChunkHolder getChunkHolder() {
+        return chunkHolder.get();
+    }
+
+    public static void setChunkHolder(ChunkHolder holder) {
+        chunkHolder.set(holder);
+    }
+
+    public static void clearChunkHolder() {
+        chunkHolder.remove();
+    }
+
+}
diff --git a/camellia-server/src/main/java/com/ishland/c2me/base/common/scheduler/WrappingTask.java b/camellia-server/src/main/java/com/ishland/c2me/base/common/scheduler/WrappingTask.java
new file mode 100644
index 0000000..a934083
--- /dev/null
+++ b/camellia-server/src/main/java/com/ishland/c2me/base/common/scheduler/WrappingTask.java
@@ -0,0 +1,67 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2021-2026 ishland
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.ishland.c2me.base.common.scheduler;
+
+import com.ishland.flowsched.executor.LockToken;
+
+import java.util.Objects;
+
+public class WrappingTask extends AbstractPosAwarePrioritizedTask {
+
+    private static final LockToken[] EMPTY_LOCK_TOKENS = new LockToken[0];
+
+    private final Runnable wrapped;
+
+    public WrappingTask(long pos, Runnable wrapped) {
+        super(pos);
+        this.wrapped = Objects.requireNonNull(wrapped);
+    }
+
+    @Override
+    public void run(Runnable releaseLocks) {
+        try {
+            wrapped.run();
+        } finally {
+            releaseLocks.run();
+            for (Runnable runnable : this.postExec) {
+                try {
+                    runnable.run();
+                } catch (Throwable t1) {
+                    t1.printStackTrace();
+                }
+            }
+        }
+    }
+
+    @Override
+    public void propagateException(Throwable t) {
+        t.printStackTrace();
+    }
+
+    @Override
+    public LockToken[] lockTokens() {
+        return EMPTY_LOCK_TOKENS;
+    }
+}