Generating execution trace diagram for a go program

[Shan Valleru]

In Go 1.5, it seems like you can generate a execution flow diagram (like this - https://talks.golang.org/2015/dynamic-tools/trace.png) for a go program using trace command.

Anybody know the detailed steps for generating such a flow diagram from a go program?

[Egon]

On Wednesday, 19 August 2015 23:32:16 UTC+3, Shan Valleru wrote:

In Go 1.5, it seems like you can generate a execution flow diagram (like this - https://talks.golang.org/2015/dynamic-tools/trace.png) for a go program using trace command.

Anybody know the detailed steps for generating such a flow diagram from a go program?

Here's the code I used to create a 10s trace from a server. You should be able to modify it to your own needs.

import "runtime/trace"

func trace10(w http.ResponseWriter, r *http.Request) {

f, err := os.Create(time.Now().Format("2006-01-02T150405.pprof"))

if err != nil {

panic(err)

}

defer f.Close()

if err := trace.Start(f); err != nil {

panic(err)

}

defer trace.Stop()

// All the important stuff is happening in other goroutines so we just wait here

time.Sleep(10 * time.Second)

}

Once you have integrated that into your own code whatever way you need:

// on Linux you can create/analyze it as:

go build .

./program

go tool trace program 2015-08-20T133508.pprof

// on Windows

go build .

program.exe

go tool trace program.exe 2015-08-20T133508.pprof

[ondrej...@gmail.com]

This is excellent, really helpful. The -help flag only mentions testing and casual searching only again pops up with info on more testing, I couldn't see anything on actually using it for running a generic binary. Perhaps it would be worth adding this to the documentation?

+ things like not needing the binary as an argument since 1.7 etc.

Or maybe just an example in the package file https://golang.org/pkg/runtime/trace/