pprof-2.go

package main

import (
	"flag"
	"log"
	"os"
	"runtime"
	"runtime/pprof"
	"sync"
	"time"
)

var cpuprofile = flag.String("cpuprofile", "", "write cpu profile to `file`")
var memprofile = flag.String("memprofile", "", "write memory profile to `file`")

func main() {
	flag.Parse()
	if *cpuprofile != "" {
		f, err := os.Create(*cpuprofile)
		if err != nil {
			log.Fatal("could not create CPU profile: ", err)
		}
		if err := pprof.StartCPUProfile(f); err != nil {
			log.Fatal("could not start CPU profile: ", err)
		}
		defer pprof.StopCPUProfile()
	}

	// ... rest of the program ...

	if *memprofile != "" {
		f, err := os.Create(*memprofile)
		if err != nil {
			log.Fatal("could not create memory profile: ", err)
		}
		runtime.GC() // get up-to-date statistics
		if err := pprof.WriteHeapProfile(f); err != nil {
			log.Fatal("could not write memory profile: ", err)
		}
		f.Close()
	}

	go func() {
		var wg sync.WaitGroup
		for i := 0; i < 100; i++ {
			wg.Add(i)
			go leakyFunction(wg)
			wg.Wait()
		}
	}()
}

func leakyFunction(wg sync.WaitGroup) {
	defer wg.Done()
	s := make([]string, 3)
	for i := 0; i < 10000000; i++ {
		s = append(s, "lambdaman..")
		if (i % 100000) == 0 {
			time.Sleep(500 * time.Millisecond)
		}
	}
}