diff --git a/main.py b/main.py
index c78e1b2..3e38de1 100644
--- a/main.py
+++ b/main.py
@@ -146,20 +146,22 @@ async def fastapi_dump_inp(network: str, inp: str) -> bool:
     dump_inp(network, inp)
     return True
 
-lock = threading.Lock()
+app.state.lock = asyncio.Lock()  # Create an async lock object
 
 # 必须用这个PlainTextResponse，不然每个key都有引号
 @app.get("/runproject/", response_class = PlainTextResponse)
 async def fastapi_run_project(network: str) -> str:
-    if lock.locked():
+    if app.state.lock.locked():
         raise HTTPException(status_code=400, detail="is in simulation")
     else:
         try:
-            with lock:
-                result = run_project(network)
-                return result
+            app.state.lock.acquire()  # Acquire the lock
+            result = run_project(network)
+            return result
         except asyncio.CancelledError:
             raise HTTPException(status_code=400, detail="is in simulation")
+        finally:
+            app.state.lock.release()
 
 # put in inp folder, name without extension
 @app.get("/runinp/")