+ /**
+ * Sleep until the time of abstime is passed.
+ */
+ static bool sleepUntil(const SGTimeStamp& abstime);
+
+ /**
+ * Sleep for reltime.
+ */
+ static bool sleepFor(const SGTimeStamp& reltime);
+
+ /**
+ * Alias for the most common use case with milliseconds.
+ */
+ static bool sleepForMSec(unsigned msec)
+ { return sleepFor(fromMSec(msec)); }
+
+ /**
+ * elapsed time since the stamp was taken, in msec
+ */
+ int elapsedMSec() const;