On Tue, Feb 19, 2019 at 9:34 AM Manlio Perillo <manlio.peri...@gmail.com> wrote: > > The Go language specification never mentions undefined behavior, however > Ian Lance Taylor wrote, in [1], that: > > - if your program has a race condition, the behavior is undefined. > > [1] https://groups.google.com/forum/#!topic/golang-nuts/MB1QmhDd_Rk:
Although I did say that, I want to clarify that I'm not really comfortable with saying that Go ever has undefined behavior in the sense that C does. Race conditions in general are covered by the Go memory model at https://golang.org/ref/mem. That document explains how you need to write your program to guarantee certain behavior. If you don't write your program that way, the results are unspecified. However, I don't think they are undefined in the sense of C. For example, if two different goroutines write to the same global variable then we don't know which value that variable will get, and we don't necessarily know for sure that it will get one value or the other--it may in some cases get some peculiar combination of the values. And the program may panic or even simply crash. But I'm not comfortable saying that the program is undefined in the sense of C, in which anything at all may happen. In particular I'm not comfortable saying that a Go compiler may optimize in the way that a C compiler may, by assuming that undefined behavior may never happen. I'm not sure that Go will ever have undefined behavior in that sense. 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.
