Merge branch 'improve_swmr' into '2.0'
io: add a function to get the 'swmr' to be used.
See merge request !182 (merged)
(cherry picked from commit fb6a67c5)
62df5bd5 io: add a function to get the 'swmr' to be used. cb7ec932 CI: add CI for testing swmr on and off