class Puma::ThreadPool

def trim(force=false)


even if all threads are being utilized.
and exit. If +force+ is true, then a trim request is requested
If there are any free threads in the pool, tell one to go ahead 
def trim(force=false)
  with_mutex do
    free = @waiting - @todo.size
    if (force or free > 0) and @spawned - @trim_requested > @min
      @trim_requested += 1
      @not_empty.signal
    end
  end
end