Hi Alexis.
Thank you for fixes the benchMarck.
About the class GSSManagerImpl, yes it is necessary because the
System.getProperty(USE_NATIVE_PROP) returns a String.
On Sat, May 24, 2014 at 12:19 PM, Aleksey Shipilev <
aleksey.shipi...@oracle.com> wrote:
> On 05/24/2014 06:34 PM, Otávio Gonçalves de Santana wrote:
> > The Boolean class has cache for true and false and using it, will save
> > memory and will faster than using create new instance of boolean.
> > Using JMH[1] with a code test[2] the result was:
>
> I agree Boolean.valueOf (whether explicit or implicit) should be used if
> identity is not required. Do you really need explicit Boolean.valueOf
> in, say, GSSManagerImpl, instead of relying on autoboxing?
>
> That said, your benchmark is not correct. At very least, you have to use
> explicit BlackHoles to avoid DCE [1][2]. This is how you do it:
>
> @State(Scope.Thread)
> @OutputTimeUnit(TimeUnit.SECONDS)
> public class BooleanBenchmark {
>
> @Param("1000000")
> private int size;
>
> private List<String> booleanString;
> private boolean[] booleans;
>
> @Setup
> public void s() {
> booleans = new boolean[size];
> booleanString = new ArrayList<String>(size);
>
> for (int index = 0; index < size; index++) {
> if (index % 2 == 0) {
> booleans[index] = true;
> booleanString.add(Boolean.TRUE.toString());
> } else {
> booleans[index] = false;
> booleanString.add(Boolean.FALSE.toString());
> }
> }
> }
>
> @GenerateMicroBenchmark
> public void valueOfBoolean(BlackHole bh) {
> for (boolean b : booleans) {
> Boolean result = b;
> bh.consume(result);
> }
> }
>
> @GenerateMicroBenchmark
> public void valueOfString(BlackHole bh) {
> for (String b : booleanString) {
> Boolean result = Boolean.valueOf(b);
> bh.consume(result);
> }
> }
>
> @GenerateMicroBenchmark
> public void newInstanceBoolean(BlackHole bh) {
> for (boolean b : booleans) {
> Boolean result = new Boolean(b);
> bh.consume(result);
> }
> }
>
> @GenerateMicroBenchmark
> public void newInstanceString(BlackHole bh) {
> for (String b : booleanString) {
> Boolean result = new Boolean(b);
> bh.consume(result);
> }
> }
> }
>
> Thanks,
> -Aleksey.
>
>
> [1]
>
> http://hg.openjdk.java.net/code-tools/jmh/file/75f8b23444f6/jmh-samples/src/main/java/org/openjdk/jmh/samples/JMHSample_08_DeadCode.java
> [2]
>
> http://hg.openjdk.java.net/code-tools/jmh/file/75f8b23444f6/jmh-samples/src/main/java/org/openjdk/jmh/samples/JMHSample_09_Blackholes.java
>
>
--
Atenciosamente.
Otávio Gonçalves de Santana
blog: http://otaviosantana.blogspot.com.br/
twitter: http://twitter.com/otaviojava
site: http://www.otaviojava.com.br
(11) 98255-3513
