Hello Luiz et al.,
thanks for your answer and sorry for digging that thread up again. At
least for the reference:
The invalid file descriptor warning stems from the g_io_channel_shutdown
call in attrib/interactive.c:disconnect_io. Afaict the
g_io_channel_shutdown call is redundant and thus causes the glib
warning. When establishing the connection gatttool uses approximately
the following call sequence.
attrib/utils.c:gatt_connect
> btio/btio.c:bt_io_connect
> btio/btio.c:create_io
> **socket**
> btio/btio.c:l2cap_connect
> **connect**
In btio/btio.c:create_io the socket is created, a corresponding glib IO
channel is created in a call to g_io_channel_unix_new and the IO channel
is instructed to close the socket as soon as the last IO channel
reference is dropped in a call to g_io_channel_set_close_on_unref.
When disconnecting in gatttool, the last reference to the glib IO
channel seems to be dropped somewhere at the end of the following call
sequence (after the last reference to the ATT object is dropped in
bt_att_unref):
attrib/interactive.c:disconnect_io
> attrib/gattrib.c:g_attrib_unref
> src/shared/att.c:bt_att_unref
> src/shared/att.c:bt_att_free
> ...
In a nutshell: Afaict the g_io_channel_unref call in disconnect_io is
redundant since the last IO channel reference is dropped in
g_attrib_unref before this call. Since the IO channel is instructed to
close the socket when the last reference is dropped, the call to
g_io_channel_shutdown is also redundant (see attached patch). Applying
the patch will indeed get rid of the glib warning. Can somebody second
that this the correct way of fixing the cleanup sequence?
Regards,
Tobias
On 27/07/15 10:27, Luiz Augusto von Dentz wrote:
Hi Tobias,
On Mon, Jul 27, 2015 at 10:14 AM, Tobias Preclik
<linux-bluetooth@xxxxxxxxxxxxxxxxx> wrote:
Hello,
it seems the cleanup process when disconnecting from a bluetooth LE device
changed in bluez 5.32 but gatttool (attrib/interactive.c:disconnect_io)
wasn't updated.
$ ./gatttool -I
[ ][LE]> connect FF:A7:8C:98:46:B6 random
Attempting to connect to FF:A7:8C:98:46:B6
Connection successful
[FF:A7:8C:98:46:B6][LE]> disconnect
(gatttool:20949): GLib-WARNING **: Invalid file descriptor.
[FF:A7:8C:98:46:B6][LE]> exit
What's the right way to do it in gatttool/bluez 5.32?
There are new tools to use with GATT, bluetoothctl/bluetoothd is the
preferred since with that you have GAP, etc, but if want to use a
stand alone tool then I suggest you use btgatt-client.
diff -crB bluez-5.40-orig/attrib/interactive.c bluez-5.40/attrib/interactive.c
*** bluez-5.40-orig/attrib/interactive.c 2016-07-07 15:20:13.955103280 +0200
--- bluez-5.40/attrib/interactive.c 2016-07-07 15:20:23.170926414 +0200
***************
*** 191,199 ****
g_attrib_unref(attrib);
attrib = NULL;
opt_mtu = 0;
-
- g_io_channel_shutdown(iochannel, FALSE, NULL);
- g_io_channel_unref(iochannel);
iochannel = NULL;
set_state(STATE_DISCONNECTED);
--- 191,196 ----
