On Wed, Nov 30, 2016 at 2:35 PM, Daniel Fanjul <daniel.fanjul.alcu...@gmail.com> wrote: > Err... I think you understood the opposite. > > A no answer would mean this is that issue. A yes answer means the mutex is > still not enough. I said yes.
I understood that, but the only implication I could draw is that mutexes are useless. Issue 7948 is about generally cleaning up the memory model with respect to the sync package. Ian > On Wednesday, November 30, 2016 at 11:23:49 PM UTC+1, Ian Lance Taylor > wrote: >> >> On Wed, Nov 30, 2016 at 2:01 PM, Daniel Fanjul >> <daniel.fan...@gmail.com> wrote: >> > I was going to answer no, but after a careful review of the go memory >> > model >> > section regarding locks, I am replying: yes, I would. >> > >> > Because the memory model only specifies "happens before" restrictions >> > between calls to Lock() and Unlock() and that is not this case. >> > "For any sync.Mutex or sync.RWMutex variable l and n < m, call n of >> > l.Unlock() happens before call m of l.Lock() returns." >> > "For any call to l.RLock on a sync.RWMutex variable l, there is an n >> > such >> > that the l.RLock happens (returns) after call n to l.Unlock and the >> > matching >> > l.RUnlock happens before call n+1 to l.Lock." >> > >> > The inner most goroutine would run the assignment and a call to l.Lock() >> > or >> > l.Unlock(). You can still swap the actions and "the [resulting] >> > reordering >> > does not change the behavior within that goroutine as defined by the >> > language specification". >> >> OK, I think this is https://golang.org/issue/7948. >> >> 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. -- 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.
