SG-17742 Attempt to fix the crash issue with Houdini

python/app/dialog.py

@@ -38,6 +38,7 @@
 from .note_updater import NoteUpdater
 from .widget_all_fields import AllFieldsWidget
 from .work_area_dialog import WorkAreaDialog
+from .utils import monitor_qobject_lifetime
 
 shotgun_model = sgtk.platform.import_framework(
     "tk-framework-shotgunutils", "shotgun_model"
@@ -135,8 +136,10 @@ def __init__(self, parent=None):
 
         # create a background task manager
         self._task_manager = task_manager.BackgroundTaskManager(
-            self, start_processing=True, max_threads=2
+            self, max_threads=2
         )
+        monitor_qobject_lifetime(self._task_manager, "Main task manager")
+        self._task_manager.start_processing()
 
         # register the data fetcher with the global schema manager
         shotgun_globals.register_bg_task_manager(self._task_manager)
@@ -278,6 +281,10 @@ def closeEvent(self, event):
         # close splash
         self._overlay.hide()
 
+        # destroy the current Qt Model
+        self._overlay.destroy()
+        self.destroy()
+
         # okay to close dialog
         event.accept()
 
@@ -869,7 +876,7 @@ def _change_work_area(self, entity_type, entity_id):
                     }
 
                     self._app.log_debug(
-                        "Creating new task:\n%s" % pprint.pprint(sg_data)
+                        "Creating new task:\n%s" % pprint.pformat(sg_data)
                     )
                     task_data = self._app.shotgun.create("Task", sg_data)
                     (entity_type, entity_id) = (task_data["type"], task_data["id"])
@@ -1208,6 +1215,8 @@ def setup_entity_model_view(self, entity_data):
         entity_data["model"] = ModelClass(
             entity_data["entity_type"], entity_data["view"], self._task_manager
         )
+        monitor_qobject_lifetime(entity_data["model"])
+
 
         # create proxy for sorting
         entity_data["sort_proxy"] = FilterItemProxyModel(self)

python/app/utils.py

@@ -216,3 +216,63 @@ def create_human_readable_timestamp(datetime_obj):
         time_str = datetime_obj.strftime("%H:%M")
 
     return (time_str, full_time_str)
+
+
+# storage for any tracked qobjects
+_g_monitored_qobjects = {}
+
+
+def monitor_qobject_lifetime(obj, name=""):
+    """
+    Debug method to help track the lifetime of a QObject derived instance.  Hooks into
+    the instances destroyed signal to report when the QObject has been destroyed.
+
+    :param obj:     The QObject instance to monitor
+    :param name:    An optional name to be appended to the debug output, useful for identifying
+                    a specific instance of a class.
+    """
+    msg = type(obj).__name__
+    if name:
+        msg = "%s [%s]" % (msg, name)
+
+    app = sgtk.platform.current_bundle()
+
+    global _g_monitored_qobjects
+    uid = len(_g_monitored_qobjects)
+    _g_monitored_qobjects[uid] = msg
+    obj.destroyed.connect(lambda m=msg, u=uid: _on_qobject_destroyed(m, u))
+
+
+def _on_qobject_destroyed(name, uid):
+    """
+    Slot triggered whenever a monitored qobject is destroyed - reports to debug that the object
+    was destroyed.
+
+    :param name:    Name of the instance that was destroyed
+    :param uid:     Unique id of the QObject used to look it up in the monitored list
+    """
+    app = sgtk.platform.current_bundle()
+    app.log_debug("%s destroyed" % name)
+    global _g_monitored_qobjects
+    if uid in _g_monitored_qobjects:
+        del _g_monitored_qobjects[uid]
+
+
+def report_non_destroyed_qobjects(clear_list=True):
+    """
+    Report any monitored QObjects that have not yet been destroyed.  Care should be taken to
+    account for QObjects that are pending destruction via deleteLater signals that may be
+    pending.
+
+    :param clear_list:  If true then the list of monitored QObjects will be cleared after
+                        this function has reported them.
+    """
+    app = sgtk.platform.current_bundle()
+    global _g_monitored_qobjects
+    app.log_debug(
+        "%d monitored QObjects have not been destroyed!" % len(_g_monitored_qobjects)
+    )
+    for msg in _g_monitored_qobjects.values():
+        app.log_debug(" - %s" % msg)
+    if clear_list:
+        _g_monitored_qobjects = {}

python/app/widget_all_fields.py

@@ -85,7 +85,7 @@ def clear(self):
                 # set it's parent to None so that it is removed from the widget hierarchy
                 x.setParent(None)
                 # mark it to be deleted when event processing returns to the main loop
-                x.deleteLater()
+                x.destroy()
 
             self._widgets = []