[Qemu-devel] [PATCH] fix race between timer firing vs. alarm_timer->pending = 0

[Paolo Bonzini]

The period for Win32 timers is very short and always the same
independent of dynticks, so it's possible that the timer fires
before qemu_run_all_timers has reset alarm_timer->pending to zero.
Reset alarm_timer->pending before rearming.

Signed-off-by: Paolo Bonzini <address@hidden>

Signed-off-by: Paolo Bonzini <address@hidden>
---
 qemu-timer.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/qemu-timer.c b/qemu-timer.c
index 329d3a4..49eac86 100644
--- a/qemu-timer.c
+++ b/qemu-timer.c
@@ -706,14 +706,14 @@ void configure_icount(const char *option)
 
 void qemu_run_all_timers(void)
 {
+    alarm_timer->pending = 0;
+
     /* rearm timer, if not periodic */
     if (alarm_timer->expired) {
         alarm_timer->expired = 0;
         qemu_rearm_alarm_timer(alarm_timer);
     }
 
-    alarm_timer->pending = 0;
-
     /* vm time timers */
     if (vm_running) {
         qemu_run_timers(vm_clock);
-- 
1.6.6.1