On Fri, 24 Sep 2021 10:35:54 GMT, Сергей Цыпанов
<[email protected]> wrote:
> Currently on each invocation of `URLClassPath.FileLoader.getResource()`
> `normalizedBase` URL is recalculated using same final `baseURL` from parent
> class. This can be avoided giving significant improvement in memory
> consumption. Consider the benchmark:
>
> @State(Scope.Benchmark)
> @BenchmarkMode(Mode.AverageTime)
> @OutputTimeUnit(TimeUnit.NANOSECONDS)
> @Fork(jvmArgsAppend = {"-Xms2g", "-Xmx2g"})
> public class URLClassPathBenchmark {
> private final ClassLoader classLoader = getClass().getClassLoader();
>
> @Benchmark
> public URL getResource() {
> return
> classLoader.getResource("file:./config/application.properties");
> }
> }
>
> it demonstrates improvement brought in by this patch:
>
> before
> Benchmark Mode Cnt
> Score Error Units
> URLClassPathBenchmark.getResource avgt 50
> 2840,746 ± 22,206 ns/op
> URLClassPathBenchmark.getResource:·gc.alloc.rate avgt 50
> 645,313 ± 8,072 MB/sec
> URLClassPathBenchmark.getResource:·gc.alloc.rate.norm avgt 50
> 2403,258 ± 17,639 B/op
> URLClassPathBenchmark.getResource:·gc.churn.G1_Eden_Space avgt 50
> 656,624 ± 116,090 MB/sec
> URLClassPathBenchmark.getResource:·gc.churn.G1_Eden_Space.norm avgt 50
> 2450,175 ± 440,011 B/op
> URLClassPathBenchmark.getResource:·gc.churn.G1_Survivor_Space avgt 50
> 0,123 ± 0,149 MB/sec
> URLClassPathBenchmark.getResource:·gc.churn.G1_Survivor_Space.norm avgt 50
> 0,459 ± 0,556 B/op
> URLClassPathBenchmark.getResource:·gc.count avgt 50
> 67,000 counts
> URLClassPathBenchmark.getResource:·gc.time avgt 50
> 117,000 ms
>
> after
> Benchmark Mode Cnt
> Score Error Units
> URLClassPathBenchmark.getResource avgt 100
> 2596,719 ± 9,786 ns/op
> URLClassPathBenchmark.getResource:·gc.alloc.rate avgt 100
> 448,780 ± 1,684 MB/sec
> URLClassPathBenchmark.getResource:·gc.alloc.rate.norm avgt 100
> 1528,040 ± 0,005 B/op
> URLClassPathBenchmark.getResource:·gc.churn.G1_Eden_Space avgt 100
> 479,905 ± 23,369 MB/sec
> URLClassPathBenchmark.getResource:·gc.churn.G1_Eden_Space.norm avgt 100
> 1634,314 ± 79,821 B/op
> URLClassPathBenchmark.getResource:·gc.churn.G1_Survivor_Space avgt 100
> 0,101 ± 0,097 MB/sec
> URLClassPathBenchmark.getResource:·gc.churn.G1_Survivor_Space.norm avgt 100
> 0,345 ± 0,329 B/op
> URLClassPathBenchmark.getResource:·gc.count avgt 100
> 98,000 counts
> URLClassPathBenchmark.getResource:·gc.time avgt 100
> 218,000 ms
This is calling an overidable method within a constructor, which might have
unforeseen side effects. Can you make `Loader::getBaseURL` final? That would
remove the concern.
-------------
PR: https://git.openjdk.java.net/jdk/pull/5677
