class Puma::Server

def pool_capacity

@!attribute [r] pool_capacity
value would be 4 until it finishes processing.
a request. If one request comes in, then the
there are 5 threads sitting idle ready to take
For example if the number is 5 then it means

the server is capable of taking right now.
This number represents the number of requests that
def pool_capacity
  @thread_pool&.pool_capacity
end