liburcu-dev binary package in Ubuntu Focal arm64

 This data synchronization library provides read-side access which scales
 linearly with the number of cores. It does so by allowing multiples copies of
 a given data structure to live at the same time, and by monitoring the data
 structure accesses to detect grace periods after which memory reclamation is
 possible.
 .
 Install this package if you wish to develop your own programs using the
 userspace RCU library.

Source package