How accurate is system nanoTime?

nanoTime() is a great function, but one thing it’s not: accurate to the nanosecond. The accuracy of your measurement varies widely depending on your operation system, on your hardware and on your Java version. As a rule of thumb, you can expect microsecond resolution (and a lot better on some systems).

What is Nano time?

NanoTime is the key foundry certified, golden signoff solution for transistor level design. It creates block-level timing models that can be used with PrimeTime® for full-chip signoff.

Is system currentTimeMillis accurate?

Regarding accuracy, you are almost correct. On SOME Windows machines, currentTimeMillis() has a resolution of about 10ms (not 50ms).

Is system currentTimeMillis expensive?

Put another way: there’s nothing inherently costly about System. currentTimeMillis(). It’s pretty fast, especially compared to the 5-second wait you’re attempting to generate.

Is system nanoTime unique?

No, there is no guarantee that every call to System. nanoTime() will return a unique value.

Is nanoTime monotonic?

5 Answers. System. nanoTime should be monotonically increasing — if you have two calls to it, A and B , and A happens-before B , then A <= B . But in practice, you can actually observe nanoTime going “backwards.”

Is system currentTimeMillis thread safe?

public static long currentTimeMillis() // Returns the current time in milliseconds. Pros: It is thread safe. Thread safety means that if this method is called between two or more different threads, it will not return erroneous results.

How does nanoTime work java?

nanoTime. Returns the current value of the running Java Virtual Machine’s high-resolution time source, in nanoseconds. This method can only be used to measure elapsed time and is not related to any other notion of system or wall-clock time.

How do you convert nanoTime to milliseconds in Java?

long startTime = System. nanoTime(); methodToTime(); long endTime = System. nanoTime(); long duration = (endTime – startTime); //divide by 1000000 to get milliseconds.

How small is a nanosecond?

A nanosecond (ns) is an SI unit of time equal to one billionth of a second, that is, 1⁄1 000 000 000 of a second, or 10−9 seconds.

How does system currentTimeMillis work?

currentTimeMillis() method returns the current time in milliseconds. The unit of time of the return value is a millisecond, the granularity of the value depends on the underlying operating system and may be larger. For example, many operating systems measure time in units of tens of milliseconds.

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