From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54997) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Wx9cX-00027D-61 for qemu-devel@nongnu.org; Wed, 18 Jun 2014 02:45:30 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Wx9cO-0003R5-2h for qemu-devel@nongnu.org; Wed, 18 Jun 2014 02:45:21 -0400 Received: from mail-wg0-x233.google.com ([2a00:1450:400c:c00::233]:64039) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Wx9cN-0003Qr-Rh for qemu-devel@nongnu.org; Wed, 18 Jun 2014 02:45:11 -0400 Received: by mail-wg0-f51.google.com with SMTP id x12so332487wgg.22 for ; Tue, 17 Jun 2014 23:45:11 -0700 (PDT) Sender: Paolo Bonzini From: Paolo Bonzini Date: Wed, 18 Jun 2014 08:44:00 +0200 Message-Id: <1403073840-32603-37-git-send-email-pbonzini@redhat.com> In-Reply-To: <1403073840-32603-1-git-send-email-pbonzini@redhat.com> References: <1403073840-32603-1-git-send-email-pbonzini@redhat.com> Subject: [Qemu-devel] [PATCH 2.1 36/36] monitor: protect event emission List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: wenchaoqemu@gmail.com, lcapitulino@redhat.com Event emission must be protected by a mutex because of access to the shared rate-limiting state, and to guard against concurrent monitor "hot-plug" by means of human-monitor-command. Reviewed-by: Luiz Capitulino Signed-off-by: Paolo Bonzini --- monitor.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/monitor.c b/monitor.c index 2b97e4e..38a64a3 100644 --- a/monitor.c +++ b/monitor.c @@ -217,6 +217,9 @@ struct Monitor { /* QMP checker flags */ #define QMP_ACCEPT_UNKNOWNS 1 +/* Protects mon_list, monitor_event_state. */ +static QemuMutex monitor_lock; + static QLIST_HEAD(mon_list, Monitor) mon_list; static QLIST_HEAD(mon_fdsets, MonFdset) mon_fdsets; static int mon_refcount; @@ -465,6 +468,7 @@ static MonitorQAPIEventState monitor_qapi_event_state[QAPI_EVENT_MAX]; /* * Emits the event to every monitor instance, @event is only used for trace + * Called with monitor_lock held. */ static void monitor_qapi_event_emit(QAPIEvent event, QObject *data) { @@ -497,6 +501,7 @@ monitor_qapi_event_queue(QAPIEvent event, QDict *data, Error **errp) now); /* Rate limit of 0 indicates no throttling */ + qemu_mutex_lock(&monitor_lock); if (!evstate->rate) { monitor_qapi_event_emit(event, QOBJECT(data)); evstate->last = now; @@ -521,6 +526,7 @@ monitor_qapi_event_queue(QAPIEvent event, QDict *data, Error **errp) evstate->last = now; } } + qemu_mutex_unlock(&monitor_lock); } /* @@ -536,12 +542,14 @@ static void monitor_qapi_event_handler(void *opaque) evstate->data, evstate->last, now); + qemu_mutex_lock(&monitor_lock); if (evstate->data) { monitor_qapi_event_emit(evstate->event, evstate->data); qobject_decref(evstate->data); evstate->data = NULL; } evstate->last = now; + qemu_mutex_unlock(&monitor_lock); } /* @@ -5285,6 +5293,11 @@ static void monitor_readline_flush(void *opaque) monitor_flush(opaque); } +static void __attribute__((constructor)) monitor_lock_init(void) +{ + qemu_mutex_init(&monitor_lock); +} + void monitor_init(CharDriverState *chr, int flags) { static int is_first_init = 1; @@ -5322,7 +5335,10 @@ void monitor_init(CharDriverState *chr, int flags) monitor_event, mon); } + qemu_mutex_lock(&monitor_lock); QLIST_INSERT_HEAD(&mon_list, mon, entry); + qemu_mutex_unlock(&monitor_lock); + if (!default_mon || (flags & MONITOR_IS_DEFAULT)) default_mon = mon; } -- 1.9.3