Concurrent Hash Map javadoc question

[Martin Buchholz]

I was wrong and filed

   1. DK <https://bugs.openjdk.java.net/browse/JDK>
   2. JDK-8231592 <https://bugs.openjdk.java.net/browse/JDK-8231592>

Clarify that ConcurrentHashMap compute methods mapping functions execute at
most once


On Wed, Sep 18, 2019 at 7:23 AM Keith Turner <keith at deenlo.com> wrote:

> On Tue, Sep 17, 2019 at 9:35 PM Martin Buchholz <martinrb at google.com>
> wrote:
> >
> > I think this doc difference is intentional.
>
> If that is the case, it would be really nice update the javadoc to
> make it explicit.
>
> >
> > In case of a retry loop, the value may have changed in the case of
> computeIfPresent or compute and so the function must be called again with
> the new value.
> >
> > On Tue, Sep 17, 2019 at 4:36 PM Martijn Verburg <
> martijnverburg at gmail.com> wrote:
> >>
> >> Hi Keith,
> >>
> >> I think this is one for concurrency interest to answer.
> >>
> >> Cheers,
> >> Martijn
> >>
> >>
> >> On Tue, 17 Sep 2019 at 12:48, Keith Turner <keith at deenlo.com> wrote:
> >>
> >> > The javadoc for ConcurrentHashMap.computeIfAbsent() states the
> >> > remapping function is applied at most once.  The functions
> >> > computeIfPresent() and compute() do not explicitly state if the
> >> > remapping functions could possibly be run multiple times. Does anyone
> >> > know if computeIfPresent() and compute() are guaranteed to only run
> >> > the remapping functions at most once?  If so, should the javadoc be
> >> > updated?
> >> >
> >> > Thanks,
> >> >
> >> > Keith
> >> >
>