Mastering High Performance with Kotlin

Using black holes

You can use an instance of Blackhole explicitly, but it's really useful if you're going to consume several values with the black hole. In another case, this approach just affects readability and it would be better to just return the value. The next example demonstrates correct and incorrect cases:

@BenchmarkMode(Mode.AverageTime)@OutputTimeUnit(TimeUnit.NANOSECONDS)@State(Scope.Thread)public class MyBenchmark {    double x1 = Math.PI;    double x2 = Math.PI * 2;    @Benchmark    public double baseline() {        return Math.log(x1);    }    @Benchmark    public double measureWrong() {        Math.log(x1);        return Math.log(x2);    }    @Benchmark    public double measureRight_1() {        return Math.log(x1) + Math.log(x2);    }    @Benchmark    public void measureRight_2(Blackhole ...