From add40e9777de139fb317ca6b1fb0dc142601cfcd Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Thu, 3 Oct 2013 15:11:43 +0200 Subject: timer: add timer_mod_anticipate and timer_mod_anticipate_ns These let a user anticipate the deadline of a timer, atomically with other sites that call the function. This helps avoiding complicated lock hierarchies. Reviewed-by: Alex Bligh Signed-off-by: Paolo Bonzini --- qemu-timer.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) (limited to 'qemu-timer.c') diff --git a/qemu-timer.c b/qemu-timer.c index 0305ad5313..e15ce477cc 100644 --- a/qemu-timer.c +++ b/qemu-timer.c @@ -410,11 +410,40 @@ void timer_mod_ns(QEMUTimer *ts, int64_t expire_time) } } +/* modify the current timer so that it will be fired when current_time + >= expire_time or the current deadline, whichever comes earlier. + The corresponding callback will be called. */ +void timer_mod_anticipate_ns(QEMUTimer *ts, int64_t expire_time) +{ + QEMUTimerList *timer_list = ts->timer_list; + bool rearm; + + qemu_mutex_lock(&timer_list->active_timers_lock); + if (ts->expire_time == -1 || ts->expire_time > expire_time) { + if (ts->expire_time != -1) { + timer_del_locked(timer_list, ts); + } + rearm = timer_mod_ns_locked(timer_list, ts, expire_time); + } else { + rearm = false; + } + qemu_mutex_unlock(&timer_list->active_timers_lock); + + if (rearm) { + timerlist_rearm(timer_list); + } +} + void timer_mod(QEMUTimer *ts, int64_t expire_time) { timer_mod_ns(ts, expire_time * ts->scale); } +void timer_mod_anticipate(QEMUTimer *ts, int64_t expire_time) +{ + timer_mod_anticipate_ns(ts, expire_time * ts->scale); +} + bool timer_pending(QEMUTimer *ts) { return ts->expire_time >= 0; -- cgit v1.2.1