defer_timer_benchmarks.go

// goos: darwin
// goarch: arm64
// pkg: github.com/hashicorp/raft
// BenchmarkTimeAfter-10                436           3896361 ns/op         2152307 B/op      30001 allocs/op
// BenchmarkTimer-10                    764           1399790 ns/op         2000058 B/op      30001 allocs/op
// BenchmarkWithoutDefer-10         3362208               356.1 ns/op             0 B/op          0 allocs/op
// BenchmarkWithDefer1-10            406236              2952 ns/op               0 B/op          0 allocs/op
// BenchmarkWithDefer2-10            404098              2956 ns/op               0 B/op          0 allocs/op

const timerBenchAttempt = 10000

func BenchmarkTimeAfter(b *testing.B) {
	b.ReportAllocs()
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		for attempt := 0; attempt < timerBenchAttempt; attempt++ {
			select {
			case <-time.After(50 * time.Millisecond):
			default:
			}
		}
	}
}

func BenchmarkTimer(b *testing.B) {
	b.ReportAllocs()
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		for attempt := 0; attempt < timerBenchAttempt; attempt++ {
			timer := time.NewTimer(50 * time.Millisecond)
			select {
			case <-timer.C:
			default:
				timer.Stop()
			}
		}
	}
}

func BenchmarkWithoutDefer(b *testing.B) {
	b.ReportAllocs()
	b.ResetTimer()

	for i := 0; i < b.N; i++ {
		if ans := withoutDefer(1098); ans != 881296890 {
			panic(ans)
		}
	}
}

func BenchmarkWithDefer1(b *testing.B) {
	b.ReportAllocs()
	b.ResetTimer()

	for i := 0; i < b.N; i++ {
		if ans := withDefer1(1098); ans != 881296890 {
			panic(ans)
		}
	}
}

func BenchmarkWithDefer2(b *testing.B) {
	b.ReportAllocs()
	b.ResetTimer()

	for i := 0; i < b.N; i++ {
		if ans := withDefer2(1098); ans != 881296890 {
			panic(ans)
		}
	}
}

func withDefer1(v int) (ans int) {
	if v > 1 {
		defer func() {
			ans *= 2
		}()
	}

	for i := 0; i < v; i++ {
		ans += i * i
	}

	return
}

func withDefer2(v int) (ans int) {
	defer func() {
		if v > 1 {
			ans *= 2
		}
	}()

	for i := 0; i < v; i++ {
		ans += i * i
	}

	return
}

func withoutDefer(v int) (ans int) {
	for i := 0; i < v; i++ {
		ans += i * i
	}

	if v > 1 {
		ans *= 2
	}

	return
}