On Tue, May 08, 2012 at 11:20:18PM +0800, Yunkai Zhang wrote: > On Tue, May 8, 2012 at 11:06 PM, Christoph Hellwig <hch at infradead.org> wrote: > > On Tue, May 08, 2012 at 11:01:53PM +0800, Yunkai Zhang wrote: > >> It works well now, I don't know what you worry about? > > > > It works most of the time, but not always. ?Even worse the reace is > > small enough that you won't find it during most testing, and only run > > into it on some heavily loaded production system once in a while. > > Producer: watcher thread > Consumer: main thread > > 1) watcher thread: > When sheep leave, /sheepdog/member/<nodeid_to_str> was deleted by > zookeeper server, watcher() will forge an LEAVE event, and: > atomic_add_and_return(&nr_zk_levents, 1) > > 2) main thread: > Check if atomic_read(&nr_zk_levents) > 0; if so, call > atomic_sub_and_return(&nr_zk_levents, 1), and processes this LEAVE > event. > > What is the problem you worry about? Can you give me an example? You're right - there is a strict relation. Care to add the above explanation as a comment? |