PR: Wait on all shutdown threads (IPython console)

spyder/app/tests/test_mainwindow.py

@@ -129,11 +129,6 @@ def test_leaks(main_window, qtbot):
 
     Many other ways of leaking exist but are not covered here.
     """
-    def wait_all_shutdown():
-        objects = gc.get_objects()
-        for o in objects:
-            if isinstance(o, KernelHandler):
-                o.wait_shutdown_thread()
 
     def ns_fun(main_window, qtbot):
         # Wait until the window is fully up
@@ -148,7 +143,7 @@ def ns_fun(main_window, qtbot):
         # Count initial objects
         # Only one of each should be present, but because of many leaks,
         # this is most likely not the case. Here only closing is tested
-        wait_all_shutdown()
+        KernelHandler.wait_all_shutdown_threads()
         gc.collect()
         objects = gc.get_objects()
         n_code_editor_init = 0
@@ -183,7 +178,7 @@ def ns_fun(main_window, qtbot):
         main_window.ipyconsole.restart()
 
         # Wait until the shells are closed
-        wait_all_shutdown()
+        KernelHandler.wait_all_shutdown_threads()
         return n_shell_init, n_code_editor_init
 
     n_shell_init, n_code_editor_init = ns_fun(main_window, qtbot)

spyder/plugins/ipythonconsole/utils/kernel_handler.py

@@ -137,6 +137,14 @@ class KernelHandler(QObject):
     The kernel raised an error while connecting.
     """
 
+    _shutdown_thread_list = []
+    """List of running shutdown threads"""
+
+    _shutdown_thread_list_lock = Lock()
+    """
+    Lock to add threads to _shutdown_thread_list or clear that list.
+    """
+
     def __init__(
         self,
         connection_file,
@@ -165,7 +173,6 @@ def __init__(
             self.handle_comm_ready)
 
         # Internal
-        self._shutdown_thread = None
         self._shutdown_lock = Lock()
         self._stdout_thread = None
         self._stderr_thread = None
@@ -489,7 +496,6 @@ def init_kernel_client(cls, connection_file, hostname, sshkey, password):
     def close(self, shutdown_kernel=True, now=False):
         """Close kernel"""
         self.close_comm()
-
         if shutdown_kernel and self.kernel_manager is not None:
             km = self.kernel_manager
             km.stop_restarter()
@@ -503,7 +509,8 @@ def close(self, shutdown_kernel=True, now=False):
                 shutdown_thread.run = self._thread_shutdown_kernel
                 shutdown_thread.start()
                 shutdown_thread.finished.connect(self.after_shutdown)
-                self._shutdown_thread = shutdown_thread
+                with self._shutdown_thread_list_lock:
+                    self._shutdown_thread_list.append(shutdown_thread)
 
         if (
             self.kernel_client is not None
@@ -515,7 +522,6 @@ def after_shutdown(self):
         """Cleanup after shutdown"""
         self.close_std_threads()
         self.kernel_comm.remove(only_closing=True)
-        self._shutdown_thread = None
 
     def _thread_shutdown_kernel(self):
         """Shutdown kernel."""
@@ -531,18 +537,19 @@ def _thread_shutdown_kernel(self):
             # kernel was externally killed
             pass
 
-    def wait_shutdown_thread(self):
+    @classmethod
+    def wait_all_shutdown_threads(cls):
         """Wait shutdown thread."""
-        thread = self._shutdown_thread
-        if thread is None:
-            return
-        if thread.isRunning():
-            try:
-                thread.kernel_manager._kill_kernel()
-            except Exception:
-                pass
-            thread.quit()
-            thread.wait()
+        with cls._shutdown_thread_list_lock:
+            for thread in cls._shutdown_thread_list:
+                if thread.isRunning():
+                    try:
+                        thread.kernel_manager._kill_kernel()
+                    except Exception:
+                        pass
+                    thread.quit()
+                    thread.wait()
+            cls._shutdown_thread_list = []
 
     def copy(self):
         """Copy kernel."""

spyder/plugins/ipythonconsole/widgets/main_widget.py

@@ -1644,10 +1644,8 @@ def close_all_clients(self):
             client.close_client(is_last_client)
             open_clients.remove(client)
 
-        # Wait for all KernelHandler's to shutdown.
-        for client in self.clients:
-            if client.kernel_handler:
-                client.kernel_handler.wait_shutdown_thread()
+        # Wait for all KernelHandler threads to shutdown.
+        KernelHandler.wait_all_shutdown_threads()
 
         # Close cached kernel
         self.close_cached_kernel()