On Wed, Sep 9, 2026, at 6:12 AM, Nazir Bilal Yavuz wrote: > Hi, > > On Tue, 8 Sept 2026 at 23:58, Nathan Bossart <[email protected]> wrote: >> >> On Tue, Sep 08, 2026 at 11:58:42AM -0400, Greg Burd wrote: >> > The test writes one full input buffer (INPUT_BUF_SIZE, 65536 bytes) down a >> > COPY FROM PROGRAM pipe: a 65524-byte line, then a complete \. marker, then >> > 8 trailing bytes. That leaves 11 bytes unexamined when the SIMD path wants >> > to refill, which is under sizeof(Vector8) and already holds the whole >> > marker. The writer then dribbles a byte every 50ms and keeps the pipe open, >> > so a speculative load blocks rather than seeing EOF. statement_timeout >> > bounds the failure, so a regression fails the test instead of hanging the >> > suite. Skipped on Windows, where the blocking pipe and SIGPIPE behavior >> > isn't reliable. >> >> I'm not sure this particular corner case deserves its own TAP test. > > I have similar feelings.
It was just a first swing at a test, and I agree with both of you it felt heavyweight for the issue at hand. But it does capture the issue. >> IMHO >> that is disproportionately expensive. It really only serves to prevent us >> from removing the backslash scan from the SIMD path, which I don't think >> we're likely to do. > > I too thought it would be expensive but it wasn't on my machine; it > took 0.5s, which is lower than I expected. > > >> Furthermore, I'm not aware of any existing examples >> where a test writes and then invokes its own Perl script, and I can't get >> too excited about being the first to commit something like that. So, I'd >> prefer to leave this test out for now. If the new test fit cleanly into an >> existing suite or was less magical, I might be more eager to include it, >> but it's probably still unlikely to be worth the energy and maintenance >> risk. Yeah, that's a solid judgement call. One I should have made myself. > Perhaps we can save this Perl script as another file and invoke that > file. This seems better to me. However, I agree that adding this test > might be overkill given the current circumstances. It's overkill, let's focus and get the fix in. > -- > Regards, > Nazir Bilal Yavuz > Microsoft best. -greg
