Hi,
fyi, jmh tests appropriate for JDK apis are located in the
test/micro/... directories.
The benchmarks are built with:
% make build-microbenchmark
The results are in the build/<platform>/images/test/micro/benchmarks.jar
$.02, Roger
On 12/11/2018 A 9:55 PM, Martin Buchholz wrote:
Hi Michal, pleased to meet you. I'll be your sponsor.
The test will need a legal header, presumably similar to others authored by
redhatters.
It is now possible to check in jmh microbenchmarks (but I've never done so
myself).
The current coding style is non-standard, but deliberate; avoid gratuitous
changes like
- Node<K,V> e;
+ Node<K, V> e;
As author of concurrent/ConcurrentHashMap/WhiteBox.java ...
- I thought you'd need a @modules ... did this test actually pass?
- you should have some kind of @summary that includes the word "whitebox"
- why not "throws ReflectiveOperationException" ?
- your reviewer is a bit on the autistic side, so please change /** to /*
on the @test comment (it's not javadoc!)
On Tue, Dec 11, 2018 at 11:06 AM Michal Vala <mv...@redhat.com> wrote:
Hi,
I've been looking into this bug in HashMap where resize() is called
multiple
times when putting whole map into another.
I come up with following patch:
http://cr.openjdk.java.net/~mvala/jdk/jdk/JDK-8210280/webrev.00/
I've tried to do it as little invasive as possible. New resize(int) method
is
called just from putMapEntries for now. Notice that method is called with
size
of the new map. I was experimenting with calling it with 'size()+s', but
this
leads to unwanted space allocation when inserted map rewrites a lot of
existing
keys.
I've benchmarked this with adding 10millions elements into existing map
and it
gets ~50% improvement:
unpatched
Benchmark Mode Cnt Score Error Units
MyBenchmark.testMethod thrpt 10 1.248 ± 0.058 ops/s
patched
Benchmark Mode Cnt Score Error Units
MyBenchmark.testMethod thrpt 10 1.872 ± 0.109 ops/s
public class MyBenchmark {
static Map<Integer, Integer> mapTocopy = IntStream.range(1,
10_000_000).boxed().collect(Collectors.toMap(k -> k,
k -> k));
@Benchmark
public int testMethod() {
var map = new HashMap<Integer, Integer>();
map.put(-5, -5);
map.putAll(mapTocopy);
return map.size();
}
}
Any ideas for missed corner-cases or some good tests?
--
Michal Vala
OpenJDK QE
Red Hat Czech
