Re-arrange startup to not use DBus activation in normal case (partial fix for bz 211636)

src/virt-manager.py.in

@@ -102,7 +102,7 @@ from virtManager.remote import vmmRemote
 
 gtk.window_set_default_icon_from_file(icon_dir + "/" + appname + "-icon.svg")
 
-# maps --show-* to engine methods
+# maps --show-* to engine (ie local instance) methods
 def show_engine(engine, show, uri, uuid):
     if show=='creator':
         engine.show_create(uri)
@@ -117,7 +117,7 @@ def show_engine(engine, show, uri, uuid):
     else:
         engine.show_connect()
 
-# maps --show-* to remote manager methods
+# maps --show-* to remote manager (ie dbus call) methods
 def show_remote(managerObj, show, uri, uuid):
     if show=='creator':
         managerObj.show_domain_creator(uri)
@@ -168,23 +168,19 @@ def main():
 
     config = vmmConfig(appname, appversion, gconf_dir, glade_dir, icon_dir)
     engine = vmmEngine(config)
-    if options.nodbus:
-        show_engine(engine, options.show, options.uri, options.uuid)
-    else:
-        bus = None
+    if not(options.nodbus) and not( (os.getenv("DBUS_SESSION_BUS_ADDRESS") is None ) and ( os.getenv("DBUS_STARTER_ADDRESS") is None ) ):
         try:
-            if os.getenv("DBUS_STARTER_ADDRESS") == None and os.getenv("DBUS_SESSION_BUS_ADDRESS") == None:
-                raise RuntimeError, "DBus session/starter bus address not defined"
+            bus = None
+            if os.getenv("DBUS_STARTER_ADDRESS") is None:
             	bus = dbus.SessionBus()
+  	    else:
+		bus = dbus.StarterBus()
 
             dbusProxy = bus.get_object("org.freedesktop.DBus", "/org/freedesktop/DBus")
             dbusObj = dbus.Interface(dbusProxy, "org.freedesktop.DBus")
 
-            # If we're already running, then just talk to existing process
-            if os.getenv("DBUS_STARTER_ADDRESS"):
-                name = dbus.service.BusName("com.redhat.virt.manager", bus=bus)
-                remote = vmmRemote(engine, name)
-            else:
+            if dbusObj.NameHasOwner("com.redhat.virt.manager"):
+                # We're already running, so just talk to existing process
                 managerProxy = bus.get_object("com.redhat.virt.manager", "/com/redhat/virt/manager")
                 managerObj = dbus.Interface(managerProxy, "com.redhat.virt.manager")
 
@@ -192,9 +188,16 @@ def main():
 
                 # yes, we exit completely now - remote service is in charge
                 return
+            else:
+                # Grab the service to allow others to talk to us later
+                name = dbus.service.BusName("com.redhat.virt.manager", bus=bus)
+                remote = vmmRemote(engine, name)
         except:
+            # Something went wrong doing dbus setup, just ignor & carry on
             logging.warning("Could not connection to session bus, disabling DBus service " + \
                             str(sys.exc_info()[0]) + " " + str(sys.exc_info()[1]))
+
+    # Finally start the app for real
     show_engine(engine, options.show, options.uri, options.uuid)
     gtk.main()