[Help]: Android: Race condition between gatt.disconnect and Bluetooth stack establishing connection

[jasaw]

Requirements

• [X] I've looked at the README 'Common Problems' section

Have you checked this problem on the example app?

No

FlutterBluePlus Version

1.32.8

Flutter Version

3.22.2

What OS?

Android

OS Version

14

Bluetooth Module

Nordic nRF

What is your problem?

In there rare case of FBP calling gatt.disconnect() while the Android Bluetooth stack is in the middle of establishing Bluetooth connection, the connection won't be cancelled even though gatt.disconnect() and gatt.close() have been called, but FBP responds to the app with connection canceled. After that, the onConnectionStateChange callback gets called and FBP happily stores the gatt against the remoteId, maintaining a Bluetooth connection that the app is not aware of.

This is not a serious issue as the app can periodically poll FBP to disconnect all Bluetooth connections, but it would be nicer if the app doesn't need to poll FBP.

Logs

D/[FBP-Android](30007): [FBP] onMethodCall: connect
D/BluetoothAdapter(30007): getBleEnabledArray(): ON
D/BluetoothGatt(30007): connect() - device: XX:XX:XX:XX:8A:77, auto: false
D/BluetoothGatt(30007): registerApp()
D/BluetoothGatt(30007): registerApp() - UUID=f06d1d8e-06a2-4466-9beb-a9dbe69aca7f
D/BluetoothGatt(30007): onClientRegistered() - status=0 clientIf=8
D/BluetoothAdapter(30007): getBleEnabledArray(): ON
I/flutter (30007): 0:00:50.491900	I	Device:	 Disconnecting Bluetooth connection
D/[FBP-Android](30007): [FBP] onMethodCall: disconnect
D/[FBP-Android](30007): [FBP] disconnect: cancelling connection in progress
D/BluetoothGatt(30007): cancelOpen() - device: XX:XX:XX:XX:8A:77
D/BluetoothGatt(30007): close()
D/BluetoothGatt(30007): onClientConnectionState() - status=0 clientIf=8 device=XX:XX:XX:XX:8A:77
D/[FBP-Android](30007): [FBP] onConnectionStateChange:connected
D/[FBP-Android](30007): [FBP]   status: SUCCESS
D/BluetoothGatt(30007): unregisterApp() - mClientIf=8
D/[FBP-Android](30007): [FBP] onMethodCall: requestMtu
D/BluetoothGatt(30007): configureMTU() - device: XX:XX:XX:XX:8A:77 mtu: 512