test: improve event-loop mocking

tests/exchange/test_exchange_ws.py

@@ -50,18 +50,18 @@ def test_exchangews_cleanup_error(mocker, caplog):
 
 
 def patch_eventloop_threading(exchange):
-    is_init = False
+    init_event = threading.Event()
 
-    def thread_fuck():
-        nonlocal is_init
+    def thread_func():
         exchange._loop = asyncio.new_event_loop()
-        is_init = True
+        init_event.set()
         exchange._loop.run_forever()
 
-    x = threading.Thread(target=thread_fuck, daemon=True)
+    x = threading.Thread(target=thread_func, daemon=True)
     x.start()
-    while not is_init:
-        pass
+    # Wait for thread to be properly initialized with timeout
+    if not init_event.wait(timeout=5.0):
+        raise RuntimeError("Failed to initialize event loop thread")
 
 
 async def test_exchangews_ohlcv(mocker, time_machine, caplog):