Another problem with select() is that trying to use a file descriptor above FD_SETSIZE in FD_SET() and the likes will actually result in overwriting the stack a

Another problem with select() is that trying to use a file descriptor above FD_SETSIZE in FD_SET() and the likes will actually result in overwriting the stack and will cause random segfaults in other areas of code. Note that sockets aren't the only thing using up file descriptors and it is quite easy to run into this issue. The solution is to use poll() as essentially a drop in replacement. Strangely the winsock version of select() acts more like poll and instead of a bitmask based on socket fds, uses an array of sockets so you can actually use a number of sockets up to FD_SETSIZE regardless of their file descriptor.