title: boost::asio io_service run integrate in main run loop of iOS application
body: <p>I'm implementing async data exchange of background thread with main thread in nonblocking mode. Found out in Unix especially iOS can use for that sockets only (based on "Advanced Programming in the UNIX Environment" W. Richard Stevens Stephen A. Rago). 
  So in my iOS application main thread is UI and background thread (from std) generates some data. I've implemented all needed callback from <code>boost::asio</code> (<code>async_accept</code>, <code>async_read</code> etc.). 
  I've tried adding <code>io_service.poll()</code> in that thread, but it looks like all callbacks are being invoked from background thread.
  And I think I need to integrate <code>io_service.run()</code> in <code>NSRunLoop</code>. How can I do that?
  Thanks.</p>