From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vasiliy G Tolstov Subject: Re: use xs_watch from userspace and use epoll instead of select Date: Fri, 03 Jun 2011 16:17:59 +0400 Message-ID: <1307103479.15777.5.camel@vase> References: <1307102689.15777.3.camel@vase> <1307103239.775.382.camel@zakaz.uk.xensource.com> Reply-To: v.tolstov@selfip.ru Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1307103239.775.382.camel@zakaz.uk.xensource.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Ian Campbell Cc: "xen-devel@lists.xensource.com" List-Id: xen-devel@lists.xenproject.org On Fri, 2011-06-03 at 13:13 +0100, Ian Campbell wrote: > On Fri, 2011-06-03 at 13:04 +0100, Vasiliy G Tolstov wrote: > > Hello. I have some examples of usage xs_watch in userspace that contains > > loop with select function usage. If i use epoll, no events returned from > > epoll_wait... > > Does it matter to use select from fd that used for watch? > > epoll fd added with ev.events = (EPOLLIN | EPOLLPRI | EPOLLONESHOT); > > I think you need to provide an example of the code which doesn't work. > > Ian. > This is not work: if ((err = xs_watch(stats->xs, "data/xenmgm", "xenmgm")) != 0) { log_error("failed to create xenstore watch on path: %s, error: %s", "data/xenmgm", strerror(err)); } fd = xs_fileno(stats->xs); xen_events = malloc(sizeof(struct epoll_event)); memset(xen_events, 0, sizeof(struct epoll_event)); if ((epfd = epoll_create(1)) < 0) { log_error("%s", "failed epoll_create"); return -1; } ev.data.fd = fd; ev.events = (EPOLLIN | EPOLLPRI | EPOLLONESHOT); if ((err = epoll_ctl(epfd, EPOLL_CTL_ADD, fd, &ev)) < 0) { log_error("%s", "failed add event via epoll_ctl"); return err; } if ((err = pthread_create(&(stats->xen_in_tid), &attr, &stats_in_tfunc, mod->data)) != 0) { log_error("failed to create thread: %s", strerror(err)); return err; } if ((err = pthread_detach(stats->xen_in_tid)) != 0) { log_error("failed to detach thread: %s", strerror(err)); return err; } in stats_in_tfunc i'm use this, but looping2 never happening for (;;) { log_debug("%s", "looping1"); if ((nr_events = epoll_wait(epfd, xen_events, 10, -1)) < 0) { log_error("%s", "failed epoll_wait"); return NULL; } log_debug("%s", "looping1"); } -- Vasiliy G Tolstov Selfip.Ru