Why are there no SoftDevice APIs that expose dynamic state?

RE: Why are there no SoftDevice APIs that expose dynamic state?

haakonsh — Tue, 01 Oct 2019 12:55:00 GMT

[quote user="Elias Simon"]This appears to be subject to the same limitation as any Application code.[/quote]

Yes, that's true.

[quote user="Elias Simon"]Can the code immediately check that this is due to pending disconnection, or does it have to wait for BLE_GAP_EVT_DISCONNECTED to confirm this?[/quote]

It has to wait for a BLE_GAP_EVT_DISCONNECTED. Though that event is sent from the SoftDevice immediately after it has itself become aware of the disconnected state of the link. Though I guess you can get a race condition where the connection state library believes a connection is valid when it, in fact, is not. Ultimately you need to handle the invalid connection handle return code from the SoftDevice calls in a non-destructive way as any connection can drop at any moment.

RE: Why are there no SoftDevice APIs that expose dynamic state?

Elias — Mon, 30 Sep 2019 18:15:49 GMT

"To keep the predefined states updated, the module uses BLE events."

This appears to be subject to the same limitation as any Application code. There's always a short period of time where the connection state is changed, but observers for the relevant BLE event have not been called.

For example, in that period of time, sd_ble_gatts_hvx() will return INVALID_STATE. Can the code immediately check that this is due to pending disconnection, or does it have to wait for BLE_GAP_EVT_DISCONNECTED to confirm this?

RE: Why are there no SoftDevice APIs that expose dynamic state?

haakonsh — Mon, 30 Sep 2019 09:33:01 GMT

See the Connection state library docs and Connection state API.