On Mon, Jun 20, 2016 at 5:57 PM, Bryan Reynaert <alke...@gmail.com> wrote:
>
> the following code panics with: runtime error: slice bounds out of range
>
>
> var testTransform = transform.Chain(norm.NFD, norm.NFC)
>
> func main() {
> for i := 0; i < 200; i++ {
> go func() {
> transform.String(testTransform, "nonemptystring")
> }()
> }
> time.Sleep(time.Second)
> }
>
> The reason is transform.Chain returns a Transformer which keeps an internal
> state
> while sequentially applying each transformation. When called by two
> goroutines,
> this state gets corrupted.
>
> For me, this was unexpected, as each transform by itself seems thread-safe.
> Errors
> caused by this behaviour might be hard to track. I suggest changing the
> implementation
> of transform.Chain.Transform to generate a new state for each call or make a
> note about
> this in the docs.
>
> Or maybe I was expecting something I should not?
>
> I can write a thread-safe version of chain.Transform if this is the way to
> go. Please comment.The general rule for the standard library is that if a type does not explicitly say that it is safe to call methods from multiple goroutines, then it is not safe to do so. That said, it may be reasonable to explicitly state that in this case. I don't think it should be made thread-safe unless the result is just as efficient. Efficiency matters here. Ian -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
