On Fri, 29 Apr 2022 03:00:40 GMT, Stuart Marks <sma...@openjdk.org> wrote:
>> Basic but fairly comprehensive set of tests for `IdentityHashMap`. The patch >> in the bug report that breaks `IdentityHashMap` now causes several cases in >> this new test to fail. There's more that could be done, but the new tests >> cover most of the core functions of `IdentityHashMap`. Unfortunately it >> seems difficult to merge this with the existing, comprehensive Collections >> tests (e.g., MOAT.java) because those tests implicity rely on >> `equals()`-based contract instead of the special-purpose `==`-based contract >> used by `IdentityHashMap`. > > Stuart Marks has updated the pull request incrementally with two additional > commits since the last revision: > > - Assertions over return values. Some refinement of equals() testing. > - Add comment about Map.Entry identity not guaranteed. Hello Stuart, I had a look at the updates. This looks good to me, thank you for the changes. Just a couple of comments/questions that I've included at relevant lines. test/jdk/java/util/IdentityHashMap/Basic.java line 50: > 48: // that a map's entrySet contains exactly the expected mappings. In most > cases, keys and > 49: // values should be compared by identity, not equality. However, the > identities of Map.Entry > 50: // instances from an IdentityHashSet are not guaranteed; the keys and > values they contain I think I understand what you are saying here, but it took me a few reads to understand it. More so because of `IdentityHashSet` here, which I think is a typo. So what's being stated here is that you cannot do something like: IdentityHashMap m = new IdentityHashMap(); ... var e1 = m.entrySet(); var e2 = m.entrySet(); assertSame(e1, e2); // this isn't guaranteed to pass Did I understand this right? test/jdk/java/util/IdentityHashMap/Basic.java line 500: > 498: Box newKey = new Box(k1a); > 499: Box newVal = new Box(v1a); > 500: Box r = map.computeIfAbsent(newKey, k -> { called[0] = true; > return newVal; }); More of a curiosity than a review comment - I see that various places in this PR use a boolean array with one element instead of just a boolean type. Is that a personal coding preference or is there something more to it? ------------- PR: https://git.openjdk.java.net/jdk/pull/8354