You could use eio with an event loop per domain and the domain manager to distribute work to other domains. The restriction at the moment is that the tasks you spin off to other domains can't do asynchronous io.
There is work on-going at the moment to bridge or even unify eio (concurrency via effects) and domainslib (nested parallelism via domains and effects) but it's a few months out.
There is work on-going at the moment to bridge or even unify eio (concurrency via effects) and domainslib (nested parallelism via domains and effects) but it's a few months out.