Use clock_gettime() instead of gettimeofday() to have a monotonic clock and use CLOCK_CONF_SECOND explicitly

arch/cpu/native/rtimer-arch.c

@@ -79,11 +79,11 @@ rtimer_arch_schedule(rtimer_clock_t t)
 
   c = t - (unsigned short)clock_time();
   
-  val.it_value.tv_sec = c / 1000;
+  val.it_value.tv_sec = c / CLOCK_SECOND;
-  val.it_value.tv_usec = (c % 1000) * 1000;
+  val.it_value.tv_usec = (c % CLOCK_SECOND) * CLOCK_SECOND;
 
-  PRINTF("rtimer_arch_schedule time %u %u in %d.%d seconds\n", t, c, c / 1000,
+  PRINTF("rtimer_arch_schedule time %u %u in %d.%d seconds\n", t, c, val.it_value.tv_sec,
-	 (c % 1000) * 1000);
+      val.it_value.tv_usec);
 
   val.it_interval.tv_sec = val.it_interval.tv_usec = 0;
   setitimer(ITIMER_REAL, &val, NULL);

arch/platform/native/Makefile.native

@@ -19,6 +19,10 @@ else
 CONTIKI_TARGET_SOURCEFILES += tun6-net.c
 endif
 
+ifeq ($(HOST_OS),Linux)
+TARGET_LIBFILES += -lrt
+endif
+
 CONTIKI_SOURCEFILES += $(CONTIKI_TARGET_SOURCEFILES)
 
 .SUFFIXES:

arch/platform/native/clock.c

@@ -42,24 +42,49 @@
 #include <sys/time.h>
 
 /*---------------------------------------------------------------------------*/
-clock_time_t
+typedef struct clock_timespec_s {
-clock_time(void)
+  time_t  tv_sec;
+  long  tv_nsec;
+} clock_timespec_t;
+/*---------------------------------------------------------------------------*/
+static void
+get_time(clock_timespec_t *spec)
 {
+#if defined(__linux__) || (defined(__MACH__) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101200)
+  struct timespec ts;
+
+  clock_gettime(CLOCK_MONOTONIC, &ts);
+
+  spec->tv_sec = ts.tv_sec;
+  spec->tv_nsec = ts.tv_nsec;
+#else
   struct timeval tv;
 
   gettimeofday(&tv, NULL);
 
-  return tv.tv_sec * 1000 + tv.tv_usec / 1000;
+  spec->tv_sec = tv.tv_sec;
+  spec->tv_nsec = tv.tv_usec * 1000;
+#endif
+}
+/*---------------------------------------------------------------------------*/
+clock_time_t
+clock_time(void)
+{
+  clock_timespec_t ts;
+
+  get_time(&ts);
+
+  return ts.tv_sec * CLOCK_SECOND + ts.tv_nsec / (1000000000 / CLOCK_SECOND);
 }
 /*---------------------------------------------------------------------------*/
 unsigned long
 clock_seconds(void)
 {
-  struct timeval tv;
+  clock_timespec_t ts;
 
-  gettimeofday(&tv, NULL);
+  get_time(&ts);
 
-  return tv.tv_sec;
+  return ts.tv_sec;
 }
 /*---------------------------------------------------------------------------*/
 void