From b111e4d79f2b98d105235cc3a155948136320cbe Mon Sep 17 00:00:00 2001
From: shokollm <270575765+shokollm@users.noreply.github.com>
Date: Sat, 11 Apr 2026 17:35:18 +0000
Subject: [PATCH] fix: make SimulateEngine.stop() synchronous

The stop() method was async but called from a sync context,
causing 'RuntimeError: no running event loop'. Changed to sync
since it just sets flags.
---
 src/backend/app/api/simulate.py             | 2 +-
 src/backend/app/services/simulate/engine.py | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/backend/app/api/simulate.py b/src/backend/app/api/simulate.py
index f4300f9..2a4d978 100644
--- a/src/backend/app/api/simulate.py
+++ b/src/backend/app/api/simulate.py
@@ -226,7 +226,7 @@ def stop_simulation(
 
     if run_id in running_simulations:
         engine = running_simulations[run_id]
-        asyncio.create_task(engine.stop())
+        engine.stop()
         simulation.status = "stopped"
         db.commit()
 
diff --git a/src/backend/app/services/simulate/engine.py b/src/backend/app/services/simulate/engine.py
index 76be8b8..3996809 100644
--- a/src/backend/app/services/simulate/engine.py
+++ b/src/backend/app/services/simulate/engine.py
@@ -258,7 +258,7 @@ class SimulateEngine:
 
             self.signals.append(signal)
 
-    async def stop(self):
+    def stop(self):
         self.running = False
         self.status = "stopped"