Reset the io_service in preparation for a subsequent run() invocation.

void reset();

This function must be called prior to any second or later set of invocations of the run(), run_one(), poll() or poll_one() functions when a previous invocation of these functions returned due to the io_service being stopped or running out of work. This function allows the io_service to reset any internal state, such as a "stopped" flag.

This function must not be called while there are any unfinished calls to the run(), run_one(), poll() or poll_one() functions.