1 files changed, 56 insertions, 0 deletions
diff --git a/include/event2/util.h b/include/event2/util.h
index 62b94773..b152a4b4 100644
--- a/include/event2/util.h
+++ b/include/event2/util.h
@@ -292,6 +292,62 @@ extern "C" {
 #define evutil_socket_t int
 #endif
 
+/**
+ * Structure to hold information about a monotonic timer
+ *
+ * Use this with evutil_configure_monotonic_time() and
+ * evutil_gettime_monotonic().
+ *
+ * This is an opaque structure; you can allocate one using
+ * evutil_monotonic_timer_new().
+ *
+ * @see evutil_monotonic_timer_new(), evutil_monotonic_timer_free(),
+ * evutil_configure_monotonic_time(), evutil_gettime_monotonic()
+ */
+struct evutil_monotonic_timer
+#ifdef EVENT_IN_DOXYGEN_
+{/*Empty body so that doxygen will generate documentation here.*/}
+#endif
+;
+
+#define EV_MONOT_PRECISE  1
+#define EV_MONOT_FALLBACK 2
+
+/** Allocate a new struct evutil_monotonic_timer for use with the
+ * evutil_configure_monotonic_time() and evutil_gettime_monotonic()
+ * functions.  You must configure the timer with
+ * evutil_configure_monotonic_time() before using it.
+ */
+EVENT2_EXPORT_SYMBOL
+struct evutil_monotonic_timer * evutil_monotonic_timer_new(void);
+
+/** Free a struct evutil_monotonic_timer that was allocated using
+ * evutil_monotonic_timer_new().
+ */
+EVENT2_EXPORT_SYMBOL
+void evutil_monotonic_timer_free(struct evutil_monotonic_timer *timer);
+
+/** Set up a struct evutil_monotonic_timer; flags can include
+ * EV_MONOT_PRECISE and EV_MONOT_FALLBACK.
+ */
+EVENT2_EXPORT_SYMBOL
+int evutil_configure_monotonic_time(struct evutil_monotonic_timer *timer,
+                                    int flags);
+
+/** Query the current monotonic time from a struct evutil_monotonic_timer
+ * previously configured with evutil_configure_monotonic_time().  Monotonic
+ * time is guaranteed never to run in reverse, but is not necessarily epoch-
+ * based, or relative to any other definite point.  Use it to make reliable
+ * measurements of elapsed time between events even when the system time
+ * may be changed.
+ *
+ * It is not safe to use this funtion on the same timer from multiple
+ * threads.
+ */
+EVENT2_EXPORT_SYMBOL
+int evutil_gettime_monotonic(struct evutil_monotonic_timer *timer,
+                             struct timeval *tp);
+
 /** Create two new sockets that are connected to each other.
 
     On Unix, this simply calls socketpair().  On Windows, it uses the