Question

I am currently trying to use boost::asio for some simple tcp networking for the first time, and I allready came across something I am not really sure how to deal with. As far as I understand io_service.run() method is basically a loop which runs until there is nothing more left to do, which means it will run until I release my little server object. Since I allready got some sort of mainloop set up, I would rather like to update the networking loop manually from there just for the sake of simplicity, and I think io_service.poll() would do what I want, sort of like this:

void myApplication::update()
{
     myIoService.poll();
     //do other stuff
}

This seems to work, but I am still wondering if there is a drawback from this method since that does not seem to be the common way to deal with boost::asios io services. Is this a valid approach or should I rather use io_service.run() in a non blocking extra thread?

Answer 1

Using io_service::poll instead of io_service::run is perfectly acceptable. The difference is explained in the documentation

The poll() function may also be used
to dispatch ready handlers, but
without blocking.

Note that io_service::run will block if there’s any work left in the queue

The work class is used to inform the
io_service when work starts and
finishes. This ensures that the
io_service object’s run() function
will not exit while work is underway,
and that it does exit when there is no
unfinished work remaining.

whereas io_service::poll does not exhibit this behavior, it just invokes ready handlers. Also note that you will need to invoke io_service::reset on any subsequent invocation to io_service:run or io_service::poll.