Call a dbus python inside a thread

Question

I get segfaults when calling the dbus method inside the stream. This is my scenario: I have a Service1 program that provides a test method. The second Service2 program provides an expansion method. Since this method does some serious numerical calculations, I pass some parameters from exposure to the current stream reader. This thread, in turn, calls the method of the Service1 method when it finishes its work. I get segfaults in the last dbus call.

Code:

# Service1.py class Service1(Object): def __init__(self, bus): name = BusName('com.example.Service1', bus) path = '/' super(Service1, self).__init__(name, path) @method(dbus_interface='com.example.Service1', in_signature='s', out_signature='s') def test(self, test): print 'test being called' return test dbus_loop = DBusGMainLoop() dsession = SessionBus(mainloop=dbus_loop) loop = gobject.MainLoop() gobject.threads_init() im = Service1(dsession) loop.run() # Service2.py dbus_loop = DBusGMainLoop() dsession = SessionBus(mainloop=dbus_loop) class Service2(Object): def __init__(self, bus): name = BusName('com.example.Service2', bus) super(Service2, self).__init__(name, '/') self.queue = Queue() self.db = bus.get_object('com.example.Service1', '/') self.dbi = dbus.Interface(self.db, dbus_interface='com.example.Service1') @method(dbus_interface='com.example.Service2', in_signature='', out_signature='') def expose(self): print 'calling expose' self.queue.put(('params',)) def reader(self): while True: val = self.queue.get() dd = self.dbi.test('test') print dd self.queue.task_done() gobject.threads_init() loop = gobject.MainLoop() im = Service2(dsession) reader = threading.Thread(target=im.reader) reader.start() loop.run() 

To test, run Service1.py, Service2.py and later this snippet:

 dbus_loop = DBusGMainLoop() session = SessionBus(mainloop=dbus_loop) proxy = session.get_object('com.example.Service2', '/') test_i = dbus.Interface(proxy, dbus_interface='com.example.Service2') test_i.expose() 

Service2.py should work after running this code several times. But why?

Answer 1

gobject.threads_init() not enough, you need to call dbus.mainloop.glib.threads_init() to ensure the security of the dbus-glib stream.

Answer 2

In Service1.py , try calling gobject.threads_init() before assigning dbus_loop to DBusGMainLoop() .