Process Queue and Pool

[Nordlöw]

I'm looking for a variant of taskPool but for pids created by 
spawnProcess. The typical patterns it to create a set of 
potentially created processes in ProcessQueue together with a 
ProcessPool that automatically pops for the ProcessQueue when 
their the number of activate processes in ProcessPool has below a 
certain counter which is a member of ProcessPool. Maybe the Queue 
and the Pool should be one aggregate. The typically usage is in a 
build system that only keeps a limited number of processes 
activate at the same time.

Has anybody written such a thing?