On Tue, 23 Apr 2024 17:40:21 GMT, Andy Goryachev <ango...@openjdk.org> wrote:
>> John Hendrikx has updated the pull request incrementally with one additional >> commit since the last revision: >> >> Fix mac test values > > tests/system/src/test/java/test/com/sun/javafx/text/TextLayoutTest.java line > 453: > >> 451: TextLayoutTest::assumeMac, >> 452: "The quick brown लोमड़ी jumps over the lazy कुत्ता", >> 453: 160.0f, List.of(155.3047f, 91.04719f) > > Question: these numbers are compared exactly (Float::compare), can we expect > them to be exactly the same on all possible platforms/versions? Exact comparisons on float numbers should not be a problem, as long as you don't assume that with a different order of operations you will get the same result. For example, `y + x - y` may not exactly equal `x + y - y` or `x`. Since we don't have different code paths for different platforms, and since all code paths are deterministic(*), it should be fine to do an exact comparison. If this ever does fail, I think then is a good time to do a more thorough investigation. So far these tests have run dozens of time on my machine, and on several of the machines of people reviewing without problems. (*) In tests, the most often encountered source of non-determinism in Java is when a `Set` or `Map` is involved which contains objects with the default hash code which can change each time a new JVM is created; usually I change such collections to linked versions, or do an explicit sort somewhere to ensure it is deterministic again. ------------- PR Review Comment: https://git.openjdk.org/jfx/pull/1236#discussion_r1576784350
