[Boost-users] Boost.Asio async read/write callback weirdness/

From: James Vanns (james.vanns_at_[hidden])
Date: 2008-07-09 06:56:29

I am using this as my main event loop (so I can call it within another event loop that does additional processing):

wait () {
    m_io.run_one(); // Executes at most 1
    m_io.reset(); // Apparently I must do this
    m_io.poll(); // Executes 0 or more handlers but doesn't block
    m_io.reset(); // Apparently I must do this
}

So that run_one blocks until at least 1 handler has been executed and then poll doesn't block but executes the rest...

I register a callback with async_read and async_write. On the client side the write callback is executed and the buffer is emptied (I'm using asio::streambuf). However,  on the receiving endpoint (the server) the io_service reports that handlers (the correct amount for a send/write from the client side - e.g. they tally) are ready or have been executed - but no callback is actually registered. Running wireshark (ethereal) whilst the send/recvs are supposed to be happening reports that no data is sent!! That is, until I quite the client app (which closes the socket, stops the io_service etc.) then wireshark reports all the data that should have already been sent! I am really confused!! The callbacks report that the data has been sent (or at least that is what I understand) and the callbacks are even executed at the other end (or rather they're not but the io_service reports that handlers have been executed!).

Can anyone think of why this might be??

Regards,

Jim

PS: Some more code:

        async_write (m_socket, m_outbound,
                     transfer_at_least(p_max),
                     bind(&base_io::write_callback,
                          shared_from_this(),
                          placeholders::error,
                          placeholders::bytes_transferred));

        async_read (m_socket, m_inbound,
                    bind(&base_io::read_callback,
                         shared_from_this(),
                         placeholders::error,
                         placeholders::bytes_transferred));

-- 
James Vanns
Systems Programmer
Framestore CFC Ltd.