Clean up stopped event loop, disconnecting signals and file descriptor notifiers

Author: hosaka

qasync/__init__.py

@@ -342,7 +342,9 @@ def __init__(self, app=None, set_running_loop=False, already_running=False):
 
         self.__call_soon_signaller = signaller = _make_signaller(QtCore, object, tuple)
         self.__call_soon_signal = signaller.signal
-        signaller.signal.connect(lambda callback, args: self.call_soon(callback, *args))
+        self.__call_soon_signal.connect(
+            lambda callback, args: self.call_soon(callback, *args)
+        )
 
         assert self.__app is not None
         super().__init__()
@@ -438,6 +440,9 @@ def close(self):
         if self.__default_executor is not None:
             self.__default_executor.shutdown()
 
+        if self.__call_soon_signal:
+            self.__call_soon_signal.disconnect()
+
         super().close()
 
         self._timer.stop()
@@ -524,6 +529,7 @@ def _remove_reader(self, fd):
             return False
         else:
             notifier.setEnabled(False)
+            notifier.activated["int"].disconnect()
             return True
 
     def _add_writer(self, fd, callback, *args):
@@ -564,6 +570,7 @@ def _remove_writer(self, fd):
             return False
         else:
             notifier.setEnabled(False)
+            notifier.activated["int"].disconnect()
             return True
 
     def __notifier_cb_wrapper(self, notifiers, notifier, fd, callback, args):
@@ -579,8 +586,6 @@ def __notifier_cb_wrapper(self, notifiers, notifier, fd, callback, args):
             # callback. We must not re-enable it in that case.
             if notifiers.get(fd, None) is notifier:
                 notifier.setEnabled(True)
-            else:
-                notifier.activated["int"].disconnect()
 
     def __on_notifier_ready(self, notifiers, notifier, fd, callback, args):
         if fd not in notifiers:

tests/test_qeventloop.py

@@ -4,19 +4,20 @@
 # BSD License
 
 import asyncio
-import logging
-import sys
-import os
 import ctypes
+import gc
+import logging
 import multiprocessing
-from concurrent.futures import ThreadPoolExecutor, ProcessPoolExecutor
+import os
 import socket
 import subprocess
-
-import qasync
+import sys
+from concurrent.futures import ProcessPoolExecutor, ThreadPoolExecutor
 
 import pytest
 
+import qasync
+
 
 @pytest.fixture
 def loop(request, application):
@@ -790,6 +791,27 @@ async def mycoro():
     assert not loop.is_running()
 
 
+def test_selector_event_loop_cleanup(application):
+    async def app_main():
+        pass
+
+    def run_app(app):
+        event_loop = qasync.QEventLoop(app)
+        event_loop.run_until_complete(app_main())
+        event_loop.close()
+
+    for _ in range(5):
+        run_app(application)
+        gc.collect()
+        loops = [
+            obj
+            for obj in gc.get_objects()
+            if type(obj).__name__ == "QSelectorEventLoop"
+        ]
+        assert len(loops) == 0
+        del loops
+
+
 def teardown_module(module):
     """
     Remove handlers from all loggers