I have been building a multi threaded server, with each thread having a single epoll fd to manage incoming tcp connections. For inter thread communication I used unix domain sockets with the intention of leveraging the existing per thread epoll.
But it seems that, Epoll stops returning network socket events if the unix domain socket is also added.
My question is can one Epoll instance be used to track events on both tcp sockets and unix domain sockets? Is this the expected behaviour? I didn't come across any literature suggesting so. Or do I need to have a separate Epoll instances to track these two different types of sockets?