Add a new timer operation kill_timer(). Effectively the

'opposite' of init_timer(), it marks the end of a timer's
lifetime. After this call the timer will not be pending,
its callback handler will not be running, and future calls
to set_timer() will silently fail.

Signed-off-by: Keir Fraser <keir@xensource.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/xen/include/xen/timer.h b/xen/include/xen/timer.h
index c89e98c346..f53a7ed35f 100644
--- a/xen/include/xen/timer.h
+++ b/xen/include/xen/timer.h
@@ -22,6 +22,8 @@ struct timer {
     void         *data;
     /* Timer-heap offset. */
     unsigned int  heap_offset;
+    /* Has this timer been killed (cannot be activated)? */
+    int           killed;
 };
 
 /*
@@ -64,6 +66,13 @@ extern void set_timer(struct timer *timer, s_time_t expires);
 extern void stop_timer(struct timer *timer);
 
 /*
+ * Deactivate a timer and prevent it from being re-set (future calls to
+ * set_timer will silently fail). When this function returns it is guaranteed
+ * that the timer callback handler is not running on any CPU.
+ */
+extern void kill_timer(struct timer *timer);
+
+/*
  * Initialisation. Must be called before any other timer function.
  */
 extern void timer_init(void);