##### io_service::run_one (2 of 2 overloads)

Run the io_service's event processing loop to execute at most one handler.

    std::size_t run_one(
        asio::error_code & ec);

The run_one() function blocks until one handler has been dispatched, or until the io_service has been stopped.

###### Parameters

ec

  Set to indicate what error occurred, if any.

###### Return Value

The number of handlers that were executed.