From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51777) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YFfum-0007dp-GR for qemu-devel@nongnu.org; Mon, 26 Jan 2015 04:25:09 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YFfud-0005s8-ES for qemu-devel@nongnu.org; Mon, 26 Jan 2015 04:25:00 -0500 Received: from mail-wg0-x22a.google.com ([2a00:1450:400c:c00::22a]:45422) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YFfud-0005s3-7F for qemu-devel@nongnu.org; Mon, 26 Jan 2015 04:24:51 -0500 Received: by mail-wg0-f42.google.com with SMTP id x13so7874126wgg.1 for ; Mon, 26 Jan 2015 01:24:50 -0800 (PST) Received: from playground.station (net-2-35-193-154.cust.vodafonedsl.it. [2.35.193.154]) by mx.google.com with ESMTPSA id 7sm13482382wjq.29.2015.01.26.01.24.49 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 26 Jan 2015 01:24:49 -0800 (PST) Sender: Paolo Bonzini From: Paolo Bonzini Date: Mon, 26 Jan 2015 10:24:19 +0100 Message-Id: <1422264270-19278-9-git-send-email-pbonzini@redhat.com> In-Reply-To: <1422264270-19278-1-git-send-email-pbonzini@redhat.com> References: <1422264270-19278-1-git-send-email-pbonzini@redhat.com> Subject: [Qemu-devel] [PULL 08/19] 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 9a3504c..ca5befb 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 -- 1.8.3.1