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Using list command in go tool pprof sometimes some lines of code are missing.

There is beginning of the function:

func SlowSearch(out io.Writer) {

    file, err := os.Open(filePath)
    if err != nil {
        panic(err)
    }

    fileContents, err := ioutil.ReadAll(file)
    if err != nil {
        panic(err)
    }

    r := regexp.MustCompile("@")
    seenBrowsers := []string{}
    uniqueBrowsers := 0
    foundUsers := ""

This works normal:

go test -bench . -cpuprofile bench_cpu.pprof
go tool pprof .\hw3.test.exe .\bench_cpu.pprof

Result:

(pprof) list SlowSearch
Total: 5.12s
ROUTINE ======================== hw3.SlowSearch in C:\Egor\MyProject\learn_mail.ru\3\99_hw\common.go
         0      910ms (flat, cum) 17.77% of Total
         .          .     18:   file, err := os.Open(filePath)
         .          .     19:   if err != nil {
         .          .     20:           panic(err)
         .          .     21:   }

There is only function definiton line is missed.

This works worse:

go test -bench . -benchmem -cpuprofile bench_cpu.pprof -memprofile bench_mem.pprof -memprofilerate 1

Result:

(pprof) list SlowSearch
Total: 4.40s
ROUTINE ======================== hw3.SlowSearch in C:\Egor\MyProject\learn_mail.ru\3\99_hw\common.go
         0      1.67s (flat, cum) 37.95% of Total
         .          .     28:   r := regexp.MustCompile("@")
         .          .     29:   seenBrowsers := []string{}
         .          .     30:   uniqueBrowsers := 0
         .          .     31:   foundUsers := ""

Much more source lines are missed.

Golang version:

go version go1.16.3 windows/amd64

I have tried to delete all binary files and rebuild - result the same. Commands list, weblist, web interface with parameter -http give same result with same missed lines in source code.

How can I return missed lines of function?

Egor Artemenko
  • 1
  • Probably because there are no samples for any of those lines, so even if it did show the lines, there would be no more information. – JimB Jun 16 '21 at 14:07
  • @JimB , there is cum > 0: ` . 40ms 23: fileContents, err := ioutil.ReadAll(file)` – Egor Artemenko Jun 16 '21 at 16:15

0 Answers0