feat(example): add bench with setup

Author: not-matthias

example/helper.go

@@ -0,0 +1,45 @@
+package example
+
+import "time"
+
+//go:noinline
+func recursiveFib(n int) uint64 {
+	if n <= 1 {
+		return uint64(n)
+	}
+	return recursiveFib(n-1) + recursiveFib(n-2)
+}
+
+//go:noinline
+func expensiveOperation() uint64 {
+	// Large memory allocation
+	data := make([]uint64, 1024*1024) // 8 MiB allocation
+	for i := range data {
+		data[i] = 42
+	}
+
+	// Expensive recursive computation that will dominate flamegraph
+	fibResult := recursiveFib(30)
+
+	// More expensive work - sum the data
+	sum := uint64(0)
+	for _, v := range data {
+		sum += v
+	}
+
+	return sum + fibResult
+}
+
+//go:noinline
+func doWork(n int) uint64 {
+	if n <= 1 {
+		return uint64(n)
+	}
+	return doWork(n-1) + doWork(n-2)
+}
+
+func actualWork() uint64 {
+	time.Sleep(1 * time.Millisecond)
+	result := doWork(30)
+	return 42 + result
+}

example/setup_test.go

@@ -0,0 +1,29 @@
+package example
+
+import (
+	"runtime"
+	"testing"
+)
+
+func BenchmarkLargeSetup(b *testing.B) {
+	expensiveOperation()
+	b.ResetTimer()
+
+	var result uint64
+	for i := 0; i < b.N; i++ {
+		result = actualWork()
+	}
+	runtime.KeepAlive(result)
+}
+
+func BenchmarkLargeSetupInLoop(b *testing.B) {
+	var result uint64
+	for i := 0; i < b.N; i++ {
+		b.StopTimer()
+		expensiveOperation()
+		b.StartTimer()
+
+		result = actualWork()
+	}
+	runtime.KeepAlive(result)
+}