On 26/01/2016 10:38 PM, Bruce Evans wrote: > On Tue, 26 Jan 2016, Kubilay Kocak wrote: > >>> Log: >>> Restore flushing of output for revoke(2) again. Document revoke()'s >>> intended behaviour in its man page. Simplify tty_drain() to match. >>> Don't call ttydevsw methods in tty_flush() if the device is gone >>> since we now sometimes call it then. >>> ... >>> This was first broken then fixed in 1995. I changed only the tty >>> ... >> >> Seems like >> >>> This was next broken in 1997 then fixed in 1998. Importing Lite2 made >>> ... >> >> A fantastic >> >>> This was next broken in 2008 by replacing everything in tty.c and not >>> ... >> >> Regression test candidate :) >> >>> It is now possible to fix this better using the new FREVOKE flag. > > Regression tests for devices are difficult to write and more difficult > to run. Simpler for ttys than for networking or disks, but you still > need at least 2 generic tty ports just to test things that are not > very related to hardware.
Of course, though perhaps mocking external subsystems/components is something we could do, as is relatively standard for testing only the code you want to cover, rather than (requiring) the entire integration. > Bugs in flushing and draining are sometimes obvious by observing if > echo 123 >/dev/ttyXx works when it should fail or fails when it should > work. > > For more arcane bugs, I use the old NIST POSIX test suite. This is > badly written and hard to use and not very complete, but it finds about > 30 regressions between FreeBSD-5 and FreeBSD-9. 30 over-counts for error > cascades but undercounts for blocking and some other timing bugs, and > of course strict POSIX tests don't get near FreeBSD features like > revoke() or bidrectional devices. > > Bruce _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
