On Fri, 29 Apr 2022 03:00:40 GMT, Stuart Marks <[email protected]> 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
