runtime: A new method to get function created goroutine required.

[ghost]

$ go version
go version go1.4.2 linux/amd64

runtime.Stack() prints 'createdby', but there's no other way to access it. runtime.Caller() and runtime.Callers() does not provide goroutine creator info.

[ianlancetaylor]

What would this function return? What would the arguments be?

[ghost]

Ah sorry.

Return *runtime.Func and get one uimtptr as argument, like runtime.FuncForPc() But I don't what naming would be right for this

I wrote this on golang-nuts but it does not appears now

[ianlancetaylor]

I'm sorry, I still don't understand. What would the uintptr argument be?

Are you suggesting something like

func CreatedBy() *Func

which would return the function that created the current goroutine? Or something like

func CreatedBy() (pc uintptr, file string, line int, ok bool)

along the lines of Caller?

One thing I'm wondering about is how useful it is to get the creator of the current goroutine. I don't see any way to ask for the creator of any other goroutine.

Can you describe a use for this in practice?

[ghost]

I mean something like https://golang.org/pkg/runtime/#FuncForPC

func ParentFuncForPC(pc uintptr) *Func
or
func CreatorFuncForPC(pc uintptr) *Func

pc is program count of goroutine.

And this would allow priting even other function's goroutines, and test of net/http library use runtime.Stack() to do this. But it parse stack trace string. https://github.com/golang/go/blob/master/src/net/http/main_test.go#L26-L51

[ianlancetaylor]

It doesn't make sense to speak of printing other function's goroutines. A single function can be being run by many goroutines simultaneously. In your suggested functions, the pc argument seems unnecessary.

[ghost]

Hmm.. I didn't meaned

func Other() {
    // from here
    GetGoroutineOf(Parent) // instead of pc..
}

func Parent() { 
    go func() { // <- get this function
        // etc..
    }()
}

I meaned a function to get

func Parent() { // <- this function
    go func() {
        // etc..
    }()
}

[ianlancetaylor]

Please write a complete small example.

[ghost]

Maybe https://github.com/ceram1/gostack/blob/master/stack_test.go#L63-L80 this can be complete example.