From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:60412) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Smnns-0001Jz-VP for qemu-devel@nongnu.org; Thu, 05 Jul 2012 11:17:18 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Smnni-0001x1-2G for qemu-devel@nongnu.org; Thu, 05 Jul 2012 11:17:12 -0400 Received: from mail-pb0-f45.google.com ([209.85.160.45]:36068) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Smnnh-0001wK-Pd for qemu-devel@nongnu.org; Thu, 05 Jul 2012 11:17:01 -0400 Received: by pbbro12 with SMTP id ro12so14161944pbb.4 for ; Thu, 05 Jul 2012 08:16:59 -0700 (PDT) Sender: Paolo Bonzini From: Paolo Bonzini Date: Thu, 5 Jul 2012 17:16:23 +0200 Message-Id: <1341501390-797-3-git-send-email-pbonzini@redhat.com> In-Reply-To: <1341501390-797-1-git-send-email-pbonzini@redhat.com> References: <1341501390-797-1-git-send-email-pbonzini@redhat.com> Subject: [Qemu-devel] [PATCH uq/master 2/9] event_notifier: remove event_notifier_test List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: kvm@vger.kernel.org, mst@redhat.com, jan.kiszka@siemens.com, mtosatti@redhat.com, avi@redhat.com, anthony.perard@citrix.com, stefano.stabellini@eu.citrix.com This is broken; since the eventfd is used in nonblocking mode there is a race between reading and writing. Signed-off-by: Paolo Bonzini --- event_notifier.c | 15 --------------- event_notifier.h | 1 - 2 files changed, 16 deletions(-) diff --git a/event_notifier.c b/event_notifier.c index 2b210f4..c339bfe 100644 --- a/event_notifier.c +++ b/event_notifier.c @@ -51,18 +51,3 @@ int event_notifier_test_and_clear(EventNotifier *e) int r = read(e->fd, &value, sizeof(value)); return r == sizeof(value); } - -int event_notifier_test(EventNotifier *e) -{ - uint64_t value; - int r = read(e->fd, &value, sizeof(value)); - if (r == sizeof(value)) { - /* restore previous value. */ - int s = write(e->fd, &value, sizeof(value)); - /* never blocks because we use EFD_SEMAPHORE. - * If we didn't we'd get EAGAIN on overflow - * and we'd have to write code to ignore it. */ - assert(s == sizeof(value)); - } - return r == sizeof(value); -} diff --git a/event_notifier.h b/event_notifier.h index efca852..9b2edf4 100644 --- a/event_notifier.h +++ b/event_notifier.h @@ -24,6 +24,5 @@ void event_notifier_cleanup(EventNotifier *); int event_notifier_get_fd(EventNotifier *); int event_notifier_set(EventNotifier *); int event_notifier_test_and_clear(EventNotifier *); -int event_notifier_test(EventNotifier *); #endif -- 1.7.10.2