What precision can I expect from Thread.sleep()?
The fundamental problem with short sleeps is that a call to sleep finishes the current scheduling time slice. Only after all other threads/process finished, the call can return. For the Sun JDK, Thread.sleep(1) is reported to be quite precise on Windows. For Linux, it depends on the timer interrupt of the kernel. If the kernel is compiled with HZ=1000 (the default on alpha), the precision is reported to be good. For HZ=100 (the default on x86) it typically sleeps for 20 ms. Using Thread.sleep(millis, nanos) doesn’t improve the results. In the Sun JDK, the nanosecond value is just rounded to the nearest millisecond.
