interleave_2.rb

# Job 1
sms_credits = community.sms_credits # start with 100 credits
# Switch! -------------------------------------------------------------------
                      # Job 2
                      sms_credits = community.sms_credits # still 100 credits!!
                      if sms_credits > 0
                        send_sms recipient, message

                        # take off a credit
                        community.sms_credits = sms_credits - 1
                        community.save # 99 credits
                      end
# Switch! -------------------------------------------------------------------
# Back to Job 1
if sms_credits > 0
  send_sms recipient, message

  # take off a credit
  community.sms_credits = sms_credits - 1
  community.save # also 99 credits!
end