Note initial addition of p5-Coro version 5.22 as devel/p5-Coro into
The NetBSD Packages Collection.

The Perl 5 module collection Coro manages continuations in general,
most often in the form of cooperative threads.The specific flavor
of thread offered by this module also guarantees you that it will
not switch between threads unless necessary, at easily-identified
points in your program, so locking and parallel access are rarely
an issue, making thread programming much safer and easier than using
other thread models.

(seb)