On 2024-Feb-03, Andrey M. Borodin wrote: > Here's the test draft. This test reliably reproduces sleep on CV when waiting > next multixact to be filled into "members" SLRU. > Cost of having this test: > 1. We need a new injection point type "wait" (in addition to "error" and > "notice"). It cannot be avoided, because we need to sync at least 3 processed > to observe condition we want. > 2. We need new way to declare injection point that can happen inside critical > section. I've called it "prepared injection point". > > Complexity of having this test is higher than complexity of CV-sleep patch > itself. Do we want it? If so I can produce cleaner version, currently all > multixact tests are int injection_points test module.
Well, it would be nice to have *some* test, but as you say it is way more complex than the thing being tested, and it zooms in on the functioning of the multixact creation in insane quantum-physics ways ... to the point that you can no longer trust that multixact works the same way with the test than without it. So what I did is manually run other tests (pgbench) to verify that the corner case in multixact creation is being handled correctly, and pushed the patch after a few corrections, in particular so that it would follow the CV sleeping protocol a little more closely to what the CV documentation suggests, which is not at all what the patch did. I also fixed a few comments that had been neglected and changed the name and description of the CV in the docs. Now, maybe we can still add the test later, but it needs a rebase. -- Álvaro Herrera Breisgau, Deutschland — https://www.EnterpriseDB.com/ “Cuando no hay humildad las personas se degradan” (A. Christie)
