kortschak / goroutine

Package for getting the runtime ID of a goroutine

goroutine identification

Package goroutine provides functions that will return the runtime's ID number for the calling goroutine or its creator.

The implementation is derived from Laevus Dexter's comment in Gophers' Slack #darkarts, https://gophers.slack.com/archives/C1C1YSQBT/p1593885226448300 post which linked to this playground snippet https://play.golang.org/p/CSOp9wyzydP.

The code here is an exercise in minimalism, doing as little as possible by deferring nearly all of the logic to runtime functions co-opted via //go:linkname comments.

goroutine's Issues

performance profile

Just curious if you could make a basic performance profile to see how much penalty this calls incur, I can create one if that helps? thx

unclear docs

does this lib return the current goroutine id for the calling function? you say "runtime id" what does that mean?

Currently I am using this to retrieve the current gorotuine id:

func GetGID() uint64 {
	b := make([]byte, 64)
	b = b[:runtime.Stack(b, false)]
	b = bytes.TrimPrefix(b, []byte("goroutine "))
	b = b[:bytes.IndexByte(b, ' ')]
	n, _ := strconv.ParseUint(string(b), 10, 64)
	return n
}

but tmk this is not performant, so maybe this library does what I am looking for ... faster?

race tests fail after 1.18

Running race tests on go1.19+ gives small deltas between the expected and obtained goroutine number. For example on go1.20.

$  go test -race
--- FAIL: TestID (0.39s)
    gid_test.go:31: unexpected id for goroutine number 52758: got:52861 want:52810
FAIL
exit status 1
FAIL	github.com/kortschak/goroutine	0.410s

ref #7

how this lib compares to outdated lib

Before I discovered this repo via this google group discussion:
https://groups.google.com/g/golang-nuts/c/bwJecP42Olk/m/1z_Kk9UfBgAJ?pli=1

I found this repo:
https://github.com/davecheney/junk/tree/master/id

how does this library compare with the version from davecheney?
apparently the davecheney one doesn't compile for go version > 1.5