On Wednesday, July 6, 2016 at 11:38:58 PM UTC+8, Axel Wagner wrote: > > You are misreading this. a) it implicitly refers to a single architecture > and b) it doesn't say that single-word accesses are atomic, it says that > multi-word accesses are inherently non-atomic. >
I can't get the conclusion for a) from that article. That article really imply (at least) pointers in go are atomic. That article is written by Ross Cox. Making it a single-word access is necessary but not sufficient, to actually > get atomic reads/writes you need to use sync/atomic > <https://godoc.org/sync/atomic> (and I don't understand why questions > about which accesses are atomic keep coming up on golang-nuts and /r/golang > and the like, when there exists a method that *gives* you atomic accesses > in the best way possible for any given architecture). > > On Wed, Jul 6, 2016 at 5:32 PM, T L <tapi...@gmail.com <javascript:>> > wrote: > >> http://research.swtch.com/gorace >> >> >>> ... >>> >> The race is fundamentally caused by being able to observe partial updates >>> to Go's multiword values (slices, interfaces, and strings): the updates are >>> not atomic. >>> >>> The fix is to make the updates atomic. In Go, the easiest way to do that >>> is to make the representation a single pointer that points at an immutable >>> structure. When the value needs to be updated, you allocate a new >>> structure, fill it in completely, and only then change the pointer to point >>> at it. This makes the assignment atomic: another goroutine reading the >>> pointer at the same time sees either the new data or the old data, but not >>> a mix, assuming the compiler is careful to read the pointer just once and >>> then access both fields using the same pointer value. >>> >> ... >>> >> >> >> -- >> 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...@googlegroups.com <javascript:>. >> For more options, visit https://groups.google.com/d/optout. >> > > -- 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.
