How to control boost::asio initialisation on Windows? - boost-asio

Question

I'm developing a program for a system running Windows 7 Embedded.
The program uses boost::asio sockets to communicate on both UDP and TCP sockets (it acts as a DHCP server and it's controlled by a RESTful interface).
Normally it works fine. However, occasionally it doesn't initialise correctly and won't respond to any DHCP or HTTP messages. I suspect that this is because the program has started before the underlying Winsock is ready. I naively attempted to wait for the Winsock to initialise prior to creating the boost::asio::io_service and sockets using the code below:
WSADATA wsaData;
while (WSAStartup(MAKEWORD(2,2), &wsaData))
{
BOOST_LOG_TRIVIAL(error) << "WSAStartup failed, waiting...";
boost::this_thread::sleep_for(COMMS_DELAY_PERIOD);
}
But I now realise that boost::asio is initialised before main is called on a Windows system. See the code below from winsock_init.hpp:
// Static variable to ensure that winsock is initialised before main, and
// therefore before any other threads can get started.
static const winsock_init<>& winsock_init_instance = winsock_init<>(false);
Is there a way to ensure that asio is correctly initialised in a Windows system before using it, without editing the DLL?

Answer 1

In now appreciate that the comments about DLLs in winsock_init.hpp is just an example, the asio library isn't built in to a DLL.
Also the example code only applies to MSVC (not surprising since it's Windows specific). However, on our project we build with both MSVC and MinGw (gcc) under Qt. The following code worked for us:
#include <boost/asio/detail/winsock_init.hpp>
#ifdef _MSC_VER
#pragma warning(push)
#pragma warning(disable:4073)
#pragma init_seg(lib)
boost::asio::detail::winsock_init<>::manual manual_winsock_init;
#pragma warning(pop)
#else // using MinGw (gcc)
boost::asio::detail::winsock_init<>::manual manual_winsock_init
__attribute__ ((init_priority (101)));
#endif