bugfix: try to handle USRP devices correctly to avoid crashes
Some problems when we release the device:
- Calling the destructors is wrong, we should set the pointers to NULL.
These are shared pointers, this is C++.
- We have to stop rx by doing a STREAM_MODE_STOP_CONTINUOUS.
- The end-of-burst for tx has been simplified.
This problem when we acquire the device:
- Calling get_rx_stream() many times seems to be problematic.
We now should have a better behavior with UHD 4.2 and N310. (Hopefully with others too.) No crash seen so far.
Edited by Cédric Roux