RFR: 8378354: Faulty assertion in checkInvariants method of ConcurrentHashMap

[cdw200806]

On Fri, 20 Feb 2026 15:05:18 GMT, Jaikiran Pai <jpai at openjdk.org> wrote:

> > We should create an issue in JBS for this.
> 
> I've now filed https://bugs.openjdk.org/browse/JDK-8378354.
> 
> @cdw200806, please update the title of this PR to `8378354: Faulty assertion in checkInvariants method of ConcurrentHashMap` to initiate an official review of this change. Please also merge the latest changes from master branch into this PR.

@jaikiran @DougLea @AlanBateman @liach 

Hi Colleagues in JDK, I also have another findings, but it is hard to fix. So I just mention here, please check. If you decide to raise a ticket to me, please share the ticket number to me, thanks. 

        Run this 4 line code in a main() method, JDK will throw StackOverflowError caused by recursion.
        Before throw err, the console print "{(this Map)=Some String}"


        ConcurrentHashMap map = new ConcurrentHashMap();
        map.put(map, "Some String");
        System.out.println(map);
        map.put(map, "Some String");

        The toString() method  of ConcurrentHashMap seems to fixed this issue by replace this map to "(this Map)" .
        But for hashCode() method of ConcurrentHashMap, it seems has not consider the recursion case.

        Why hard to fix: consider this case, the key has recursion it self, it will throw StackOverflowError too.
        ConcurrentHashMap map = new ConcurrentHashMap();
        Map map2 = new HashMap();
        map2.put(map2, "Some String");
        map.put(map2, "Some String");

-------------

PR Comment: https://git.openjdk.org/jdk/pull/24612#issuecomment-3936476482