Exaclty. If you look at other asio examples you'll see the same pattern: async. operations are chained in the way that completion handler of a previous operation launches the next one. This pattern allows you to end the i/o in a very simple way: just break the above chain and the io_service.run() ends. Note also that if your handlers are made of some "connection" object (using shared_from_this, like in the examples) that encapsulates socket, then when the chain terminates, this object is automatically destroyed closing its socket.

However, such a simple design is not always possible. In more complicated cases you have to keep io_service running *always*, even when there's no i/o activity - until explicitly stopped. Refer to the following example to see how you can do this:

http://www.boost.org/doc/libs/1_37_0/doc/html/boost_asio/example/http/server2/io_service_pool.cpp

I don't understand how it works :(. we have few io_service object which are run() in separated threads. but only one is maintained by async_accept chain trick. the rest run() should immediately return.

> you're welcome :)