[Sheepdog] [PATCH] zookeeper: switch gcc atomic builtins to atomic helpers

[Liu Yuan]

On 05/08/2012 08:21 PM, Yunkai Zhang wrote:

>> > The combination of a read and an atomic_sub later looks racy to me, what
>> > prevents nr_zk_levents from changing between the two calls?
> The watcher function was executed in another thread(create by
> zookeeper_init() ), we should use atomic function to read/wirte
> nr_zk_levents in any time.
> 


Maybe you don't get Christoph.

        if (!uatomic_read(&zk_notify_blocked) &&
             uatomic_read(&nr_zk_levents)) {
                nr_levents = uatomic_sub_return(&nr_zk_levents, 1) + 1;

I guess he means the possible race between uatomic_read() and
uatomic_sub_return() on the same value.

Thanks,
Yuan