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[Qemu-devel] [PATCH 3/4] qemu-timer: introduce timer_deinit
From: |
Paolo Bonzini |
Subject: |
[Qemu-devel] [PATCH 3/4] qemu-timer: introduce timer_deinit |
Date: |
Thu, 8 Jan 2015 11:03:27 +0100 |
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 <address@hidden>
---
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
- [Qemu-devel] [PATCH 0/4] qemu-timer: introduce usable pointer-free API, Paolo Bonzini, 2015/01/08
- [Qemu-devel] [PATCH 4/4] vmstate: accept QEMUTimer in VMSTATE_TIMER*, add VMSTATE_TIMER_PTR*, Paolo Bonzini, 2015/01/08
- [Qemu-devel] [PATCH 1/4] qemu-timer: rename timer_init to timer_init_tl, Paolo Bonzini, 2015/01/08
- [Qemu-devel] [PATCH 2/4] qemu-timer: add timer_init and timer_init_ns/us/ms, Paolo Bonzini, 2015/01/08
- [Qemu-devel] [PATCH 3/4] qemu-timer: introduce timer_deinit,
Paolo Bonzini <=
- Re: [Qemu-devel] [PATCH 0/4] qemu-timer: introduce usable pointer-free API, Fam Zheng, 2015/01/08