test_epoll fails on Solaris

[serhiy-storchaka]

Bug report

test_epoll fails on Solaris with 4 failures, caused by two non-portable assumptions.

1. A non-blocking connect() is assumed to fail. _connected_pair() requires EINPROGRESS, but it is only returned if the connection cannot be established immediately, and over the loopback Solaris establishes it at once. This affects test_add, test_control_and_wait, test_fromfd and test_unregister_closed:

   AssertionError: Connect should have raised EINPROGRESS
   

2. Unregistering a closed file descriptor is assumed to fail with EBADF. On Solaris it succeeds, so test_unregister_closed fails with AssertionError: OSError not raised. The descriptor is really closed (the peer reads EOF), but removing it from the epoll set still succeeds. On Linux closing a descriptor removes it from the set, so the later removal fails.

The assertion cannot be relaxed: it is the point of gh-83420, select.epoll.unregister() no longer ignores EBADF since 3.9. Solaris has no error to report, so the test can only be skipped there.

Linked PRs

• gh-154379: Fix test_epoll on Solaris #154380
• [3.15] gh-154379: Fix test_epoll on Solaris (GH-154380) #154382
• [3.14] gh-154379: Fix test_epoll on Solaris (GH-154380) #154383
• [3.13] gh-154379: Fix test_epoll on Solaris (GH-154380) #154384