Implement new/free for struct evutil_monotonic_timer and export monotonic time functions

event.c

@@ -993,6 +993,21 @@ done:
 	return (res);
 }
 
+/* Get the monotonic time for this event_base' timer */
+int
+event_gettime_monotonic(struct event_base *base, struct timeval *tv)
+{
+  int rv = -1;
+
+  if (base && tv) {
+    EVBASE_ACQUIRE_LOCK(base, th_base_lock);
+    rv = evutil_gettime_monotonic_(&(base->monotonic_timer), tv);
+    EVBASE_RELEASE_LOCK(base, th_base_lock);
+  }
+
+  return rv;
+}
+
 const char **
 event_get_supported_methods(void)
 {

evutil_time.c

@@ -54,6 +54,7 @@
 #include "event2/util.h"
 #include "util-internal.h"
 #include "log-internal.h"
+#include "mm-internal.h"
 
 #ifndef EVENT__HAVE_GETTIMEOFDAY
 /* No gettimeofday; this must be windows. */
@@ -160,6 +161,55 @@ adjust_monotonic_time(struct evutil_monotonic_timer *base,
 	base->last_time = *tv;
 }
 
+/*
+   Allocate a new struct evutil_monotonic_timer
+ */
+struct evutil_monotonic_timer *
+evutil_monotonic_timer_new(void)
+{
+  struct evutil_monotonic_timer *p = NULL;
+
+  p = mm_malloc(sizeof(*p));
+  if (!p) goto done;
+
+  memset(p, 0, sizeof(*p));
+
+ done:
+  return p;
+}
+
+/*
+   Free a struct evutil_monotonic_timer
+ */
+void
+evutil_monotonic_timer_free(struct evutil_monotonic_timer *timer)
+{
+  if (timer) {
+    mm_free(timer);
+  }
+}
+
+/*
+   Set up a struct evutil_monotonic_timer for initial use
+ */
+int
+evutil_configure_monotonic_time(struct evutil_monotonic_timer *timer,
+                                int flags)
+{
+  return evutil_configure_monotonic_time_(timer, flags);
+}
+
+/*
+   Query the current monotonic time
+ */
+int
+evutil_gettime_monotonic(struct evutil_monotonic_timer *timer,
+                         struct timeval *tp)
+{
+  return evutil_gettime_monotonic_(timer, tp);
+}
+
+
 #if defined(HAVE_POSIX_MONOTONIC)
 /* =====
    The POSIX clock_gettime() interface provides a few ways to get at a

include/event2/event.h

@@ -396,6 +396,12 @@ const char *event_base_get_method(const struct event_base *);
 EVENT2_EXPORT_SYMBOL
 const char **event_get_supported_methods(void);
 
+/** Query the current monotonic time from a the timer for a struct
+ * event_base.
+ */
+EVENT2_EXPORT_SYMBOL
+int event_gettime_monotonic(struct event_base *base, struct timeval *tp);
+
 /**
    @name event type flag
 

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

time-internal.h

@@ -86,9 +86,6 @@ struct evutil_monotonic_timer {
 	struct timeval last_time;
 };
 
-#define EV_MONOT_PRECISE  1
-#define EV_MONOT_FALLBACK 2
-
 int evutil_configure_monotonic_time_(struct evutil_monotonic_timer *mt,
     int flags);
 int evutil_gettime_monotonic_(struct evutil_monotonic_timer *mt, struct timeval *tv);