From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37110) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Y99wT-0004AP-JC for qemu-devel@nongnu.org; Thu, 08 Jan 2015 05:03:58 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Y99wK-0002Sj-4L for qemu-devel@nongnu.org; Thu, 08 Jan 2015 05:03:49 -0500 Received: from mail-we0-x231.google.com ([2a00:1450:400c:c03::231]:40123) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Y99wJ-0002Rc-UA for qemu-devel@nongnu.org; Thu, 08 Jan 2015 05:03:40 -0500 Received: by mail-we0-f177.google.com with SMTP id q59so1562454wes.8 for ; Thu, 08 Jan 2015 02:03:39 -0800 (PST) Received: from playground.station (net-37-117-147-67.cust.vodafonedsl.it. [37.117.147.67]) by mx.google.com with ESMTPSA id qg11sm21175327wic.17.2015.01.08.02.03.37 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 08 Jan 2015 02:03:38 -0800 (PST) Sender: Paolo Bonzini From: Paolo Bonzini Date: Thu, 8 Jan 2015 11:03:27 +0100 Message-Id: <1420711408-15766-4-git-send-email-pbonzini@redhat.com> In-Reply-To: <1420711408-15766-1-git-send-email-pbonzini@redhat.com> References: <1420711408-15766-1-git-send-email-pbonzini@redhat.com> Subject: [Qemu-devel] [PATCH 3/4] qemu-timer: introduce timer_deinit List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org In some cases, a timer was set to NULL so that we could check if it is initialized. Use the timer_list field instead, and add a timer_deinit function that NULLs it. It then makes sense that timer_del be a no-op (instead of a crasher) on such a de-initialized timer. It avoids the need to poke at the timerlist field to check if the timers are initialized. Signed-off-by: Paolo Bonzini --- include/qemu/timer.h | 11 +++++++++++ qemu-timer.c | 14 +++++++++++--- 2 files changed, 22 insertions(+), 3 deletions(-) diff --git a/include/qemu/timer.h b/include/qemu/timer.h index 9f44233..5d5802f 100644 --- a/include/qemu/timer.h +++ b/include/qemu/timer.h @@ -595,6 +595,17 @@ static inline QEMUTimer *timer_new_ms(QEMUClockType type, QEMUTimerCB *cb, } /** + * timer_deinit: + * @ts: the timer to be de-initialised + * + * Deassociate the timer from any timerlist. You should + * call timer_del before. After this call, any further + * timer_del call cannot cause dangling pointer accesses + * even if the previously used timerlist is freed. + */ +void timer_deinit(QEMUTimer *ts); + +/** * timer_free: * @ts: the timer * diff --git a/qemu-timer.c b/qemu-timer.c index 98d9d1b..464396f 100644 --- a/qemu-timer.c +++ b/qemu-timer.c @@ -342,6 +342,12 @@ void timer_init_tl(QEMUTimer *ts, ts->expire_time = -1; } +void timer_deinit(QEMUTimer *ts) +{ + assert(ts->expire_time == -1); + ts->timer_list = NULL; +} + void timer_free(QEMUTimer *ts) { g_free(ts); @@ -398,9 +404,11 @@ void timer_del(QEMUTimer *ts) { QEMUTimerList *timer_list = ts->timer_list; - qemu_mutex_lock(&timer_list->active_timers_lock); - timer_del_locked(timer_list, ts); - qemu_mutex_unlock(&timer_list->active_timers_lock); + if (timer_list) { + qemu_mutex_lock(&timer_list->active_timers_lock); + timer_del_locked(timer_list, ts); + qemu_mutex_unlock(&timer_list->active_timers_lock); + } } /* modify the current timer so that it will be fired when current_time -- 2.1.0