The same code, but using the new standard:
http://cr.openjdk.java.net/~chegar/docs/portingScript.html
How is the new standard I thought that I should create new thread.
Sorry.
On Sun, Jan 25, 2015 at 10:30 PM, Claes Redestad <claes.redes...@oracle.com>
wrote:
> Wait a minute. Is this the latest? Why start a new thread?
>
> Updating your benchmark to the latest JMH and running them against the
> latest JDK9 I get contradictory
> results (repeatable on two different machines):
>
> Benchmark (param) Mode Cnt Score Error Units
>
> .indexOfChar 10000 thrpt 50 3875.096 ± 12.365 ops/s
> .indexOfString 10000 thrpt 50 4523.693 ± 9.835 ops/s
>
> JMH 1.5 version:
>
> import org.openjdk.jmh.annotations.*;
> import org.openjdk.jmh.infra.Blackhole;
> ...
> private static final String WORDS = "I love java Language 8 because
> has Lambda, Stream and MetaSpace";
>
> @Param("10000")
> private int param;
>
> @Benchmark
> public void indexOfString(Blackhole bh) {
> for (int i = 0; i <= param; i++) {
> int index = WORDS.indexOf(",");
> bh.consume(index);
> }
> }
>
> @Benchmark
> public void indexOfChar(Blackhole bh) {
> for (int i = 0; i <= param; i++) {
> int index = WORDS.indexOf(',');
> bh.consume(index);
> }
> }
>
> Turning WORDS into public String words actually narrows the gap (doesn't
> really make sense to
> benchmark indexOf with a literal char/String on a literal String, IMHO):
>
> Char: 5.158 ± 0.052 ops/ms
> String: 5.314 ± 0.052 ops/ms
>
> Writing the benchmark like this:
>
> public String words = "I love java Language 8 because has Lambda,
> Stream and MetaSpace";
>
> @Benchmark
> public int indexOfString() {
> return words.indexOf(",");
> }
>
> @Benchmark
> public int indexOfChar() {
> return words.indexOf(',');
> }
>
> shows some possible benefit:
>
> Char 50.962 ± 0.529 ops/us
> String 44.765 ± 0.078 ops/us
>
> Comparing with results from older JDKs, it seems something must've subtly
> changed - perhaps
> a regression somewhere. Turning off
>
> The fact that there's no indexOf(char) but rather an indexOf(int), while
> this area is a
> minefield of intrinsics makes all of this very hard to evaluate from a
> performance point of view.
>
> Also, I think everyone would appreciate if you could split the patch into
> one patch per module.
> That'd be a natural split and will simplify getting reviews from each
> appropriate team.
>
> /Claes
>
> On 2015-01-12 23:23, Otávio Gonçalves de Santana wrote:
>
>> These String literals may be replaced by equivalent character literals[1],
>> gaining some performance enhancement.
>>
>> Webrev:
>> https://dl.dropboxusercontent.com/u/16109193/open_jdk/jdk/
>> index_of_character/index.html
>>
>>
>> [1]
>> @State(Scope.Thread)
>> @OutputTimeUnit(TimeUnit.SECONDS)
>> public class IndexOfBenchmark {
>>
>> private static final String WORDS = "I love java Language 8 because
>> has
>> Lambda, Stream and MetaSpace";
>>
>> @Param("10000")
>> private int param;
>>
>> @GenerateMicroBenchmark
>> public void indexOfString(BlackHole bh) {
>>
>> for (int i = 0; i <= param; i++) {
>> int index = WORDS.indexOf(",");
>> bh.consume(index);
>> }
>> }
>>
>> @GenerateMicroBenchmark
>> public void indexOfChar(BlackHole bh) {
>>
>> for (int i = 0; i <= param; i++) {
>> int index = WORDS.indexOf(',');
>> bh.consume(index);
>> }
>> }
>> }
>>
>> Benchmark (param) Mode Samples Mean
>> Mean error Units
>> m.IndexOfBenchmark.indexOfChar 10000 thrpt 10 5579.120
>> 114.179 ops/s
>> m.IndexOfBenchmark.indexOfString 10000 thrpt 10 4562.178
>> 46.751 ops/s
>>
>>
>
--
Otávio Gonçalves de Santana
blog: http://otaviosantana.blogspot.com.br/
twitter: http://twitter.com/otaviojava
site: *http://about.me/otaviojava <http://about.me/otaviojava>*
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