The problem with partial writes is that the data is not an unstructured stream of bytes, but a concrete binary dump. You can not simply retry again.

My bet is that "/dev/poll" neves does partial writes.

If I am mistaken, I will bug the Illumos people to help me to solve it. So far, this seems a theorical problema.

Just in case it is not, we raise an exception and urge the programmer to report us the issue.

The other option would be to try to be clever and do things like retrying if the partial write is a multiple of the struct size, but what if it not so?.

Instead of guessing and play games, I rather prefer to know if this is actually a problem in the wild. In my tests, with 65530 sockets, I never saw this "impossible" exception.