Hi,
You are right, I did some modification to your code and make it able to
reproduce everytime: https://play.golang.org/p/y6vxC_DNjp9
Thanks!
在 2019年5月8日星期三 UTC+8下午7:15:26，rog写道：
>
> It seems clear to me that C ("can run but has not implemented the
> singleton pattern, function f may r
It seems clear to me that C ("can run but has not implemented the singleton
pattern, function f may run multi times") is not the correct answer,
because I'm pretty sure that f cannot run more than once.
However, it's still not a correct Once implementation, because as has
already been pointed out,
On Tue, May 7, 2019 at 9:42 PM White Pure wrote:
> Hi,
> Thanks for your reply.
> The second bug is a known issue, so let’s ignore that. In that case, I
> think function f still can only be executed once.
> But why does the load and store of o.done need to be done using atomic
> opera
Hi,
Thanks for your reply.
The second bug is a known issue, so let’s ignore that. In that case, I
think function f still can only be executed once.
But why does the load and store of o.done need to be done using atomic
operations? I suppose there’s mutex assuring the happens-before.
Hi,
Thanks for your reply.
The second bug is a known issue, so let’s ignore that. In that case, I
think function f still can only be executed once.
But why does the load and store of o.done need to be done using atomic
operations? I suppose there’s mutex assuring the happens-before.
Hello,
The code contains two bugs.
1) The load and store of o.done needs to be done using atomic stores.
2) The statement to set o.done = 1 needs to be after the call to f.
Otherwise, another goroutine can hit the check at the top of Done and
return before the code in f has completed.
On
