Connection Management
The Zephyr Bluetooth stack uses an abstraction called bt_conn
to represent connections to other devices. The internals of this struct
are not exposed to the application, but a limited amount of information
(such as the remote address) can be acquired using the
bt_conn_get_info() API. Connection objects are reference
counted, and the application is expected to use the
bt_conn_ref() API whenever storing a connection pointer for a
longer period of time, since this ensures that the object remains valid
(even if the connection would get disconnected). Similarly the
bt_conn_unref() API is to be used when releasing a reference
to a connection.
An application may track connections by registering a
bt_conn_cb struct using the bt_conn_cb_register()
or BT_CONN_CB_DEFINE APIs. This struct lets the application
define callbacks for connection & disconnection events, as well as other
events related to a connection such as a change in the security level or
the connection parameters. When acting as a central the application will
also get hold of the connection object through the return value of the
bt_conn_le_create() API.