quick connection pool example

renting_zero.rb

require "thread"
require "connection_pool"
require "pp"

NUM_CLIENTS   = 9
MAX_AT_A_TIME = 3
TIMEOUT       = 10
JOB_TIME      = 3

# we'll let people lease access to zero
pool = ConnectionPool.new(size: MAX_AT_A_TIME, timeout: TIMEOUT) { 0 }

res = NUM_CLIENTS.times.map do |n|
  Thread.new do
    begin
      start = Time.now
      
      # let's checkout that zero and have some fun with it!
      pool.with do |zero|
        zero * n
        zero + n
        zero - n
        zero / (n.zero? ? n.succ : n)

        sleep(JOB_TIME)
      end
      
      "Completed in #{(Time.now - start).round} seconds"
    rescue Timeout::Error
      :timed_out!
    end
  end
end

pp res.map(&:value)