+uint64_t stat_segment_version (void);
+uint64_t stat_segment_version_r (stat_client_main_t * sm);
+
+typedef struct
+{
+ uint64_t epoch;
+} stat_segment_access_t;
+
+static inline uint64_t
+_time_now_nsec (void)
+{
+ struct timespec ts;
+ clock_gettime (CLOCK_REALTIME, &ts);
+ return 1e9 * ts.tv_sec + ts.tv_nsec;
+}
+
+static inline void *
+stat_segment_adjust (stat_client_main_t * sm, void *data)
+{
+ char *csh = (char *) sm->shared_header;
+ char *p = csh + ((char *) data - (char *) sm->shared_header->base);
+ if (p > csh && p + sizeof (p) < csh + sm->memory_size)
+ return (void *) p;
+ return 0;
+}
+
+/*
+ * Returns 0 on success, -1 on failure (timeout)
+ */
+static inline int
+stat_segment_access_start (stat_segment_access_t * sa,
+ stat_client_main_t * sm)
+{
+ vlib_stats_shared_header_t *shared_header = sm->shared_header;
+ uint64_t max_time;
+
+ sa->epoch = shared_header->epoch;
+ if (sm->timeout)
+ {
+ max_time = _time_now_nsec () + sm->timeout;
+ while (shared_header->in_progress != 0 && _time_now_nsec () < max_time)
+ ;
+ }
+ else
+ {
+ while (shared_header->in_progress != 0)
+ ;
+ }
+ sm->directory_vector = (vlib_stats_entry_t *) stat_segment_adjust (
+ sm, (void *) sm->shared_header->directory_vector);
+ if (sm->timeout)
+ return _time_now_nsec () < max_time ? 0 : -1;
+ return 0;
+}
+
+/*
+ * set maximum number of nano seconds to wait for in_progress state
+ */
+static inline void
+stat_segment_set_timeout_nsec (stat_client_main_t * sm, uint64_t timeout)
+{
+ sm->timeout = timeout;
+}
+
+/*
+ * set maximum number of nano seconds to wait for in_progress state
+ * this function can be called directly by module using shared stat
+ * segment
+ */
+static inline void
+stat_segment_set_timeout (uint64_t timeout)
+{
+ stat_client_main_t *sm = &stat_client_main;
+ stat_segment_set_timeout_nsec (sm, timeout);
+}
+
+
+static inline bool
+stat_segment_access_end (stat_segment_access_t * sa, stat_client_main_t * sm)
+{
+ vlib_stats_shared_header_t *shared_header = sm->shared_header;
+
+ if (shared_header->epoch != sa->epoch || shared_header->in_progress)
+ return false;
+ return true;
+}