select implementation not POSIX compliant?

Could you post the test case for this behavior: I assume your test app is buggy: a select call that is executed after close returned must return EBADF, everything else would be a bug.

Regarding your main point: The return result from select/poll is undefined in Linux if you close a descriptor while another thread polls or selects it. This is consistent with the behavior of other Unices - for example HP UX kills the process if you replace a descriptor that is being polled with dup2.

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Manfred

Actually Solaris and Linux are consistent in terms of the behavior of select in this respect. I suspect that the first select is blocking the socket from being used at all, so the second select can't tell that it is closed.

Right, hence my feeling that select is over all fairly broken. The big difference between Solaris and Linux though is that close will call recv* calls to return on Solaris, and close doesn't do that on Linux. The work around is to use shutdown on Linux before calling close. This also works on Solaris, though it makes the recv set errno differently.

Thanks for looking at this issue,
-Nick

The objects are refcounted so the socket hasn't gone away until the point the select returns.

Alan