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e36aeda | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 | // Copyright 2024 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package testing_test
import (
"math/rand/v2"
"testing"
)
// ExBenchmark shows how to use b.Loop in a benchmark.
//
// (If this were a real benchmark, not an example, this would be named
// BenchmarkSomething.)
func ExBenchmark(b *testing.B) {
// Generate a large random slice to use as an input.
// Since this is done before the first call to b.Loop(),
// it doesn't count toward the benchmark time.
input := make([]int, 128<<10)
for i := range input {
input[i] = rand.Int()
}
// Perform the benchmark.
for b.Loop() {
// Normally, the compiler would be allowed to optimize away the call
// to sum because it has no side effects and the result isn't used.
// However, inside a b.Loop loop, the compiler ensures function calls
// aren't optimized away.
sum(input)
}
// Outside the loop, the timer is stopped, so we could perform
// cleanup if necessary without affecting the result.
}
func sum(data []int) int {
total := 0
for _, value := range data {
total += value
}
return total
}
func ExampleB_Loop() {
testing.Benchmark(ExBenchmark)
}
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