Re: Concurrent Hash Map javadoc question
Martin Buchholz via Concurrency-interest <[email protected]>
| Newsgroups | gmane.comp.java.jsr.166-concurrency,gmane.comp.java.openjdk.general |
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| Message-ID | <CA+kOe0-=2k2vdGeNUPOWfX4OVn8mvps7AFnV-kRGx97mUhw5XA@mail.gmail.com> |
How about The entire method invocation is performed atomically, so the function is applied at most once per key. => The entire method invocation is performed atomically. The function is applied at most once per key. On Tue, Sep 17, 2019 at 7:08 PM Benjamin Manes <[email protected]> wrote: > All three state that "The entire method invocation is performed > atomically" and computeIfAbsent merely explains this with the addition "so > the function is applied at most once per key." Since all computations are > atomic operations in ConcurrentHashMap, this seems to be implied in the > other cases rather than explicitly clarified. > > On Tue, Sep 17, 2019 at 6:36 PM Martin Buchholz via Concurrency-interest < > [email protected]> wrote: > >> I think this doc difference is intentional. >> >> 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 <[email protected]> >> 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 <[email protected]> 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 >>> > >>> >> _______________________________________________ >> Concurrency-interest mailing list >> [email protected] >> http://cs.oswego.edu/mailman/listinfo/concurrency-interest >> > _______________________________________________ Concurrency-interest mailing list [email protected] http://cs.oswego.edu/mailman/listinfo/concurrency-interest