Is the time returned via the real-time clock of better resolution than that returned by System.nanoTime()?
The real-time clock and System.nanoTime() are both based on the same system call and thus the same clock. With Java RTS, all time-based APIs (for example, Timers, Periodic Threads, Deadline Monitoring, and so forth) are based on the high-resolution timer. And, together with real-time priorities, they can ensure that the appropriate code will be executed at the right time for real-time constraints. In contrast, ordinary Java SE APIs offer just a few methods capable of handling high-resolution times, with no guarantee of execution at a given time. Using System.nanoTime() between various points in the code to perform elapsed time measurements should always be accurate.
