gh-110697: test_os TimerfdTests uses selectors (#110789)

Replace select.epoll() with selectors.DefaultSelector to support
FreeBSD 14 and newer.

* Merge common code between test_timerfd_epoll()
  test_timerfd_ns_epoll().
* Replace "_ = func()" with "func()".
* Add TimerfdTests.read_count_signaled() method.

Victor Stinner committed 2y ago

8f07b6e4e3c5e5c549b8c2c7d14a89b2563e6b9e

Parent: a7e2a10

Committed by GitHub <noreply@github.com> on 10/13/2023, 2:20:18 PM