client.log

DEBUG:asyncio:Using selector: EpollSelector
DEBUG:asyncio:poll 24996.047 ms took 0.013 ms: 1 events
DEBUG:asyncio:poll 24994.410 ms took 0.315 ms: 1 events
ERROR:asyncio:Task was destroyed but it is pending!
source_traceback: Object created at (most recent call last):
  File "./client.py", line 75, in <module>
    loop.run_until_complete(main())
  File "/usr/lib64/python3.7/asyncio/base_events.py", line 560, in run_until_complete
    self.run_forever()
  File "/usr/lib64/python3.7/asyncio/base_events.py", line 528, in run_forever
    self._run_once()
  File "/usr/lib64/python3.7/asyncio/base_events.py", line 1756, in _run_once
    handle._run()
  File "/usr/lib64/python3.7/asyncio/events.py", line 88, in _run
    self._context.run(self._callback, *self._args)
  File "/home/tu500/.local/lib/python3.7/site-packages/dbussy.py", line 1759, in call_dispatch
    status = dispatch()
  File "/home/tu500/.local/lib/python3.7/site-packages/dbussy.py", line 2278, in dispatch
    dbus.dbus_connection_dispatch(self._dbobj)
  File "/home/tu500/.local/lib/python3.7/site-packages/dbussy.py", line 2506, in wrap_function
    result = function(self, Message(dbus.dbus_message_ref(message)), user_data)
  File "/home/tu500/.local/lib/python3.7/site-packages/ravel.py", line 2347, in _message_interface_dispatch
    bus.loop.create_task(result)
task: <Task pending coro=<LevelA.on_new_levelB() done, defined at ./client.py:56> wait_for=<Future pending cb=[<TaskWakeupMethWrapper object at 0x7fa68792f168>()] created at /usr/lib64/python3.7/asyncio/base_events.py:385> created at /home/tu500/.local/lib/python3.7/site-packages/ravel.py:2347>
ERROR:asyncio:Task was destroyed but it is pending!
source_traceback: Object created at (most recent call last):
  File "./client.py", line 75, in <module>
    loop.run_until_complete(main())
  File "/usr/lib64/python3.7/asyncio/base_events.py", line 560, in run_until_complete
    self.run_forever()
  File "/usr/lib64/python3.7/asyncio/base_events.py", line 528, in run_forever
    self._run_once()
  File "/usr/lib64/python3.7/asyncio/base_events.py", line 1756, in _run_once
    handle._run()
  File "/usr/lib64/python3.7/asyncio/events.py", line 88, in _run
    self._context.run(self._callback, *self._args)
  File "/home/tu500/.local/lib/python3.7/site-packages/dbussy.py", line 1780, in handle_watch_event
    call_dispatch()
  File "/home/tu500/.local/lib/python3.7/site-packages/dbussy.py", line 1759, in call_dispatch
    status = dispatch()
  File "/home/tu500/.local/lib/python3.7/site-packages/dbussy.py", line 2278, in dispatch
    dbus.dbus_connection_dispatch(self._dbobj)
  File "/home/tu500/.local/lib/python3.7/site-packages/dbussy.py", line 2506, in wrap_function
    result = function(self, Message(dbus.dbus_message_ref(message)), user_data)
  File "/home/tu500/.local/lib/python3.7/site-packages/ravel.py", line 2347, in _message_interface_dispatch
    bus.loop.create_task(result)
task: <Task pending coro=<LevelA.on_new_levelB() done, defined at ./client.py:56> wait_for=<Future pending cb=[<TaskWakeupMethWrapper object at 0x7fa68792f6d8>()] created at /usr/lib64/python3.7/asyncio/base_events.py:385> created at /home/tu500/.local/lib/python3.7/site-packages/ravel.py:2347>
dbus[28503]: arguments to dbus_pending_call_steal_reply() were incorrect, assertion "pending->completed" failed in file ../../dbus/dbus-pending-call.c line 733.
This is normally a bug in some application using the D-Bus library.

  D-Bus not built with -rdynamic so unable to print a backtrace

client.py

#!/usr/bin/python3

import asyncio
import ravel
import dbussy

class ClientInterface(dbussy.Introspection.Interface):

    def __init__(self):
        dbussy.Introspection.Interface.__init__(self, self._interface_name)

    def dbus_register(self, path, bus=None):
        if bus is None:
            bus = ravel.session_bus()
        self._dbus_bus = bus
        self._dbus_path = path
        bus.register(path=path, fallback=False, interface=self)

    def dbus_unregister(self):
        self._dbus_bus.unregister(path=self._dbus_path, interface=None)


@ravel.interface(ravel.INTERFACE.CLIENT, name='com.example.levelB')
class LevelB(ClientInterface):

    def __init__(self, path):
        self.path = path
        self.jobs = []

    async def init(self):
        self.dbus_register(self.path)
        self.proxy = await self._dbus_bus['com.example.foobar'][self.path] \
            .get_async_interface(self._interface_name)

@ravel.interface(ravel.INTERFACE.CLIENT, name='com.example.levelA')
class LevelA(ClientInterface):

    def __init__(self, path):
        self.path = path
        self.levelBs = []

    async def init(self):
        self.dbus_register(self.path)
        self.proxy = await self._dbus_bus['com.example.foobar'][self.path] \
            .get_async_interface(self._interface_name)

    async def start_first_stage(self):
        await self.proxy.start_first_stage()

    async def get_levelBs(self):
        l, = await self.proxy.get_levelBs()
        self.levelBs = [LevelB(p) for p in l]
        for j in self.levelBs:
            await j.init()

    @ravel.signal(in_signature='o')
    async def on_new_levelB(self, path):
        j = LevelB(path)
        await j.init()
        self.levelBs.append(j)

async def main():

    levelA = LevelA('/levelA')
    await levelA.init()
    await levelA.start_first_stage()

    await asyncio.sleep(10)

import logging
logging.basicConfig(level=logging.DEBUG)
loop = asyncio.get_event_loop()
loop.set_debug(True)
ravel.session_bus().attach_asyncio(loop)
loop.run_until_complete(main())

server.py

#!/usr/bin/python3

import asyncio
import dbussy
import ravel
import logging
from dbussy import DBUS

logging.getLogger().setLevel(logging.INFO)

class DBusObject():
    def dbus_register(self, path, bus=None):
        if bus is None:
            bus = ravel.session_bus()
        self._dbus_bus = bus
        self._dbus_path = path
        bus.register(path=path, fallback=False, interface=self)

    def dbus_unregister(self):
        self._dbus_bus.unregister(path=self._dbus_path, interface=None)

    def dbus_send_signal(self, name, *args):
        self._dbus_bus.send_signal(
                path=self._dbus_path,
                interface=self._interface_name,
                name=name,
                args=args,
            )

@ravel.interface(ravel.INTERFACE.SERVER, name='com.example.levelB')
class LevelB(DBusObject):
    def __init__(self, index, levelA):
        self.index = index
        self.path = levelA.path + '/p{}'.format(self.index)

    def init(self):
        self.dbus_register(self.path)

@ravel.interface(ravel.INTERFACE.SERVER, name='com.example.levelA')
class LevelA(DBusObject):

    def __init__(self):
        self.levelBs = []
        self.path = '/levelA'

    async def first_stage(self):
        self.levelBs = [LevelB(i, self) for i in range(5)]
        for b in self.levelBs:
            b.init()
            self.dbus_send_signal('on_new_levelB', b.path)
            print('new levelB', b.path)

    @ravel.method(
            in_signature='',
            out_signature='',
        )
    def start_first_stage(self):
        asyncio.create_task(self.first_stage())

    @ravel.signal(in_signature='o')
    def on_new_levelB(self): ...

    def init(self):
        self.dbus_register(self.path)

print('Starting server')
loop = asyncio.get_event_loop()
bus = ravel.session_bus()
bus.attach_asyncio(loop)
bus.request_name(bus_name='com.example.foobar', flags=DBUS.NAME_FLAG_DO_NOT_QUEUE)

levelA = LevelA()
levelA.init()
loop.run_forever()