getting a unique thread id?

[Friedrich Dominicus <frido q-software-solutions de>]

I have a question about thread in glib. AFAIKT there is not api
function for getting the some sort of unique thread id. The only
function which comes near is:
g_thread_self, but there is not structure but privat or so which could
yield the id of the thread. However how can that be achieved?

Thanks
Friedrich