Run the io_context
object's event processing
loop for a specified duration.
template< typename Rep, typename Period> std::size_t run_for( const chrono::duration< Rep, Period > & rel_time);
The run_for()
function blocks until all work has finished and there are no more handlers
to be dispatched, until the io_context
has been stopped, or
until the specified duration has elapsed.
The duration for which the call may block.
The number of handlers that were executed.