baseclass: Track object lifetime to help debug ref leaks

src/virtManager/baseclass.py

@@ -42,6 +42,9 @@ class vmmGObject(gobject.GObject):
         self._gobject_timeouts = []
         self._gconf_handles = []
 
+        self._object_key = str(self)
+        self.config.add_object(self._object_key)
+
     def cleanup(self):
         # Do any cleanup required to drop reference counts so object is
         # actually reaped by python. Usually means unregistering callbacks
@@ -81,6 +84,14 @@ class vmmGObject(gobject.GObject):
         from virtManager import halhelper
         return halhelper.get_hal_helper()
 
+    def __del__(self):
+        if hasattr(gobject.GObject, "__del__"):
+            getattr(gobject.GObject, "__del__")(self)
+
+        try:
+            self.config.remove_object(self._object_key)
+        except:
+            logging.exception("Error removing %s" % self._object_key)
 
 class vmmGObjectUI(vmmGObject):
     def __init__(self, filename, windowname):

src/virtManager/config.py

@@ -115,6 +115,8 @@ class vmmConfig(object):
         self.hv_packages = []
         self.libvirt_packages = []
 
+        self._objects = []
+
         self.status_icons = {
             libvirt.VIR_DOMAIN_BLOCKED: gtk.gdk.pixbuf_new_from_file_at_size(self.get_icon_dir() + "/state_running.png", 18, 18),
             libvirt.VIR_DOMAIN_CRASHED: gtk.gdk.pixbuf_new_from_file_at_size(self.get_icon_dir() + "/state_crashed.png", 18, 18),
@@ -179,6 +181,15 @@ class vmmConfig(object):
     def remove_notifier(self, h):
         self.conf.notify_remove(h)
 
+    # Used for debugging reference leaks, we keep track of all objects
+    # come and go so we can do a leak report at app shutdown
+    def add_object(self, obj):
+        self._objects.append(obj)
+    def remove_object(self, obj):
+        self._objects.remove(obj)
+    def get_objects(self):
+        return self._objects[:]
+
     # Per-VM/Connection/Connection Host Option dealings
     def _perconn_helper(self, uri, pref_func, func_type, value=None):
         suffix = "connection_prefs/%s" % gconf.escape_key(uri, len(uri))

src/virtManager/engine.py

@@ -47,6 +47,9 @@ from virtManager.error import vmmErrorDialog
 from virtManager.systray import vmmSystray
 import virtManager.util as util
 
+# Enable this to get a report of leaked objects on app shutdown
+debug_ref_leaks = False
+
 def default_uri():
     tryuri = None
     if os.path.exists("/var/lib/xend") and os.path.exists("/proc/xen"):
@@ -473,6 +476,12 @@ class vmmEngine(vmmGObject):
         conns = self.connections.values()
         for conn in conns:
             conn["connection"].close()
+        self.connections = {}
+
+        if debug_ref_leaks:
+            for name in self.config.get_objects():
+                logging.debug("Leaked %s" % name)
+
         logging.debug("Exiting app normally.")
         gtk.main_quit()