class EM::Synchrony::ActiveRecord::ConnectionPool

def execute(async)
  f = Fiber.current
  begin
    conn = acquire(f)
    conn.acquired_for_connection_pool += 1
    yield conn
  ensure
    conn.acquired_for_connection_pool -= 1
    release(f) if !async && conn.acquired_for_connection_pool == 0
  end
end