RFR: 8350811: [JMH] test foreign.StrLenTest failed with StringIndexOutOfBoundsException for size=451 [v2]

[Volodymyr Paprotski]

On Tue, 4 Mar 2025 19:37:32 GMT, Vladimir Ivanov <vaivanov at openjdk.org> wrote:

>> test setup was updated to generate data of requested size.
>
> Vladimir Ivanov has updated the pull request incrementally with one additional commit since the last revision:
> 
>   JDK-8350811 [JMH] test foreign.StrLenTest failed with StringIndexOutOfBoundsException for size=451

test/micro/org/openjdk/bench/java/lang/foreign/StrLenTest.java line 149:

> 147:         while (lorem.length() < size) {
> 148:             lorem += lorem;
> 149:         }

This is matter of taste, but I would prefer StringBuilder instead:

        StringBuilder builder = new StringBuilder(lorem.length()+size);
        for (int l = 0; l<size; l+=lorem.length()) {
            builder.append(lorem);
        }
        return builder.substring(0, size);

test/micro/org/openjdk/bench/java/lang/foreign/StrLenTest.java line 181:

> 179: 
> 180:     static class SlicingPool {
> 181:         final MemorySegment pool;

This seems ok; though I was suspicious but I can't measure a difference: with the default parameters for size of 5, 20, 100, arena was 10x-200x+ times bigger. Now it fits exactly.

I measured 1x, 10x, 100x (for size 1500 and 15000) and results appear consistent.

So, this is just a note; looks good

-------------

PR Review Comment: https://git.openjdk.org/jdk/pull/23873#discussion_r1982330072
PR Review Comment: https://git.openjdk.org/jdk/pull/23873#discussion_r1982357391