Sebb,
Do you want me to provide a patch with ConcurrentHashMap where I will have
to handle null keys and values (not same behaviour as HashMap) or we forget
about this approach ?
Regards
Philippe
On Mon, Oct 3, 2011 at 1:58 PM, Philippe Mouawad <philippe.moua...@gmail.com
> wrote:
> Hello,
> Just a little update on my test.
> I added a clear and gc before each Map instanciation and results are
> different:
>
> - HashMapput:645
> - ConcurrentHashMapput:832
> - ConcurrentReaderHashMapput:620
> - HashMap get:17
> - ConcurrentHashMap get:32
> - ConcurrentReaderHashMap get:60
>
>
> So it kind of closes the debate, sorry for disturbance.
> Regards
> Philippe
>
>
>
>
> public class TestMap {
>
> public static void main(String[] args) {
> StopWatch timer = new StopWatch();
>
> Map map = new HashMap();
> testPut(timer, map, "HashMap");
> timer.reset();
>
> map.clear();
> System.gc();
>
> map = new ConcurrentHashMap();
> testPut(timer, map, "ConcurrentHashMap");
> timer.reset();
>
> map.clear();
> System.gc();
>
> map = new ConcurrentReaderHashMap();
> testPut(timer, map, "ConcurrentReaderHashMap");
> timer.reset();
>
>
> map.clear();
> System.gc();
>
> map = new HashMap();
> testGet(timer, map, "HashMap");
> timer.reset();
>
> map.clear();
> System.gc();
>
> map = new ConcurrentHashMap();
> testGet(timer, map, "ConcurrentHashMap");
> timer.reset();
>
> map.clear();
> System.gc();
>
> map = new ConcurrentReaderHashMap();
> testGet(timer, map, "ConcurrentReaderHashMap");
> timer.reset();
> }
>
> /**
> * @param timer
> */
> private static void testGet(StopWatch timer, Map map, String type) {
> timer.start();
> for (int i = 0; i < 1000000; i++) {
> map.get(i);
> }
> timer.stop();
> System.out.println(type+" get:"+timer.getTime());
> }
>
> /**
> * @param timer
> */
> private static void testPut(StopWatch timer, Map map, String type) {
> timer.start();
> for (int i = 0; i < 1000000; i++) {
> map.put(i,i);
> }
> timer.stop();
> System.out.println(type+"put:"+timer.getTime());
> }
>
>
> Regards
> Philippe
>
>
> On Mon, Oct 3, 2011 at 1:37 PM, sebb <seb...@gmail.com> wrote:
>
>> On 3 October 2011 12:15, Rainer Jung <rainer.j...@kippdata.de> wrote:
>> > On 02.10.2011 23:17, Philippe Mouawad wrote:
>> >> Ok, hope we can do the same.
>> >
>> > See https://issues.apache.org/jira/browse/XMLBEANS-447
>> >
>> > We are not the only people, who doubt it's correct to include that class
>> ...
>> >
>> > There was also a discussion some time ago in another ASF project,
>> > because the Sun license which is cited by Doug Lea has a "no use in
>> > nuclear facilities clause", which make it non-usable as an Open Source
>> > license.
>> >
>> > It looks like we are stuck here.
>>
>> Yes, apart from the binary option which brings in lots of unneeded code.
>>
>> > And the mentioning of the Harmony class in the above cited issue is a
>> > red herring. Diffing it with the JDK 5 standard ConcurrentHashMap shows
>> > little difference, so I doubt it will be much faster (though I didn't
>> > inspect the delta in detail).
>>
>> I think the Harmony class was only mentioned as a means of supporting
>> Java 1.4, not as an alternative faster implementation.
>>
>> >> I must say I don't understand why ConcurrentReaderHashMap is not in
>> JDK.
>> >
>> > There's a discussion list for JSR166 (the concurrency stuff lead by Doug
>> > Lea) mentioned on the JSR 166 page maintained by Doug Lea. So maybe you
>> > can post a technical question there (what's the right class that solve
>> > the following problem ... and doesn't have sun licensing restrictions).
>> >
>> > Regards,
>> >
>> > Rainer
>> >
>> >
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>> >
>> >
>>
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>>
>>
>
>
> --
> Cordialement.
> Philippe Mouawad.
>
>
>
>
--
Cordialement.
Philippe Mouawad.
