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From:   Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Date:   Sun, 21 Feb 2021 15:47:02 -0800
Message-ID: <CABBYNZ+qMec0KbGx4Gfjb5yygXYzxz5WESReo3FS3_WNuqw1UA@mail.gmail.com>
Subject: Re: How to receive notifications after calling StartNotify
To:     Mihai Emilian <be.mihai22@gmail.com>
Cc:     "linux-bluetooth@vger.kernel.org" <linux-bluetooth@vger.kernel.org>
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Hi Mihai,

On Sun, Feb 21, 2021 at 9:13 AM Mihai Emilian <be.mihai22@gmail.com> wrote:
>
> Dear linux-bluetooth community,
>
> I am writing a bluetooth client in C which receives notifications from
> a bluetooth device (server). I am able to call StartNotify() from the
> bluez api and the Notifying property changes to true. However, I am
> not sure how I should listen for the notifications, or where.
>
> There are several questions:
> a) How do I provide a callback function to this?
> b) async or sync method call? Does it matter?
> c) Do I need the main loop to do this and why?

You will need to subscribe for signals, e.g. using g_signal_connect:

https://www.freedesktop.org/software/gstreamer-sdk/data/docs/latest/gio/GDBusProxy.html

Signals are async so typically that would be handled by a mainloop.

> Here's my source code https://pastebin.com/KEGTatsL
>
> Is there an example? I tried looking at the different files such as
> client in bluez kernel source and gatttool source, but I couldn't
> figure this out.
>
> Many thanks,
> Regards,
> Mihai


-- 
Luiz Augusto von Dentz