diff --git a/main.py b/main.py
index 02b8f7a..ce94cb8 100644
--- a/main.py
+++ b/main.py
@@ -33,8 +33,6 @@ if not os.path.exists(inpDir):
 if not os.path.exists(tmpDir):
     os.mkdir(tmpDir)
 
-lock_simulation = False
-
 app = FastAPI()
 
 app.add_middleware(GZipMiddleware, minimum_size=1000)
@@ -148,16 +146,17 @@ async def fastapi_dump_inp(network: str, inp: str) -> bool:
     dump_inp(network, inp)
     return True
 
+app.state.lock_simulation = False
+
 # 必须用这个PlainTextResponse，不然每个key都有引号
 @app.get("/runproject/", response_class = PlainTextResponse)
-def fastapi_run_project(network: str) -> str:
-    global lock_simulation
-    if lock_simulation:
+async def fastapi_run_project(network: str) -> str:
+    if app.state.lock_simulation:
         raise HTTPException(status_code=409, detail="is in simulation")   
 
-    lock_simulation = True
+    app.state.lock_simulation = True
     result = run_project(network)
-    lock_simulation = False
+    app.state.lock_simulation = False
     return result
         
 # put in inp folder, name without extension