Timing issue getting characteristics

[matthewhague]

• bleak version: 0.2.2
• Python version: 3.7.1
• Operating System: Arch Linux

Description

Attempting to print the available services. This fails because bleak has not yet discovered all services.

What I Did

Here is a simplified version of the code i am trying to run

async def print_services(mac_addr : str, loop : asyncio.AbstractEventLoop):
    async with BleakClient(mac_addr, loop=loop) as client:
        svcs = await client.get_services()
        print("Services:", svcs)

def do_thing(mac_addr : str):
    loop = asyncio.get_event_loop()
    loop.run_until_complete(print_services(mac_addr, loop))

The output is

    Services: {}

There should be many services. I can add a delay and get the right result:

async def print_services(mac_addr : str, loop : asyncio.AbstractEventLoop):
    async with BleakClient(mac_addr, loop=loop) as client:
        await asyncio.sleep(10)
        svcs = await client.get_services()
        print("Services:", svcs)

Which results in

Services: {'0000180a-0000-1000-8000-00805f9b34fb': {'UUID': '0000180a-0000-1000-8000-00805f9b34fb', 'Device': '/org/bluez/hci0/dev_F4_B8_5E_F3_B6_84', 'Primary': True, 'Includes': [], 'Path': '/org/bluez/hci0/dev_F4_B8_5E_F3_B6_84/service0021'}, '00001000-0000-1000-8000-00805f9b34fb': {'UUID': '00001000-0000-1000-8000-00805f9b34fb', 'Device': '/org/bluez/hci0/dev_F4_B8_5E_F3_B6_84', 'Primary': True, 'Includes': [], 'Path': '/org/bluez/hci0/dev_F4_B8_5E_F3_B6_84/service0010'}, '00001801-0000-1000-8000-00805f9b34fb': {'UUID': '00001801-0000-1000-8000-00805f9b34fb', 'Device': '/org/bluez/hci0/dev_F4_B8_5E_F3_B6_84', 'Primary': True, 'Includes': [], 'Path': '/org/bluez/hci0/dev_F4_B8_5E_F3_B6_84/service000c'}}

Apologies if this is something i have not understood about the library.

[hbldh]

Hm, strange. I will look into this tonight.

[hbldh]

I think the modification I did in version 0.2.4 will solve the problem. I could not reproduce it by your scripts in Ubuntu 18.04 installation, but I think I had misplaced the checking of the property "ServicesResolved" in getting services so this might solve your problem. Try it out and report back here.

[matthewhague]

Seems to work, thanks!