Spawn the fastCGI process

I need to spawn the FastCGI process somehow. The purpose in the
following: i have some time-consuming requests and 2 fcgi process
normally. When such time-consuming request comes, it occupies the
fastcgi process complittely, and if two such requests come, all two
processes will be occupied and no more requests server can process.
So i need the way to allow background running of such time-consuming
actions (with the ability to pause/stop if user needs).
I found some (unclear) information about fcgispawner class, can it be
Any help is welcome!!!