1 files changed, 9 insertions, 0 deletions
diff --git a/src/main.c b/src/main.c
index 61a3850..f54aa19 100644
--- a/src/main.c
+++ b/src/main.c
@@ -67,6 +67,9 @@ skip_refresh:
       break;
     }
     if (is_stop) {
+      // cooperative stop: signal all threads, wait for them to finish
+      threads_stop_all(&engine_threads);
+      threads_join(&engine_threads);
       threads_cleanup(&engine_threads);
       ipc_state_set_event(&ipc_state, EVENT_UCI_RUNNING);
       goto waiting_for_go;
@@ -76,6 +79,12 @@ skip_refresh:
   }
 
 quit:
+  // cooperative stop for engine threads, then hard-cancel the UCI thread
+  // (which blocks on stdin and cannot exit cooperatively).
+  if (engine_threads.running_count > 0) {
+    threads_stop_all(&engine_threads);
+    threads_join(&engine_threads);
+  }
   ipc_state_deinit(&ipc_state);
   pthread_cancel(uci_thread);
   threads_deinit(&engine_threads);