golang pprof example

profile.go

// Example:
//    go test <options> -cpuprofile cpu.prof -memprofile mem.prof ./...
//    go tool pprof  # Interactive console
//    go tool pprof -http=localhost:6060 cpu.prof  # Visualization

import (
  "flag"
  "log"
  "runtime"
  "runtime/pprof"
)

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

// pprof if -cpuprofile
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()
}

// <something to profile>

// pprof if -memprofile
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()
}