How can I measure time in Java not susceptible to System clock changes?

Question

I would like to measure elapsed time in a Java. However differences in System.currentTimeMillis() and (I believe) System.nanoTime() can be changed

Answer 1

If you don't mind adding a bit of native code to your Java app, use:

• QueryPerformanceCounter() and QueryPerformanceFrequency() on Windows; or

• POSIX clock_gettime() function with CLOCK_MONOTONIC clock ID.

Note that the use of the x86 TSC register is discouraged on multiprocessor systems, so you better use the above APIs.