Specifies the type of function passed to g_main_context_set_poll_func(). The semantics of the function should match those of the poll() system call.
the number of #GPollFD elements which have events or errors reported, or -1 if an error occurred.
See Implementation
Specifies the type of function passed to g_main_context_set_poll_func(). The semantics of the function should match those of the poll() system call.