How to use

nanoTime

method

in

java.lang.System

/** Calls {@link System#nanoTime()}. */
@SuppressWarnings("GoodTime") // reading system time without TimeSource
static long systemNanoTime() {
 return System.nanoTime();
}

/**
 * Returns System.nanoTime() unless the timeout has already elapsed. Returns 0L if and only if the
 * timeout has already elapsed.
 */
private static long initNanoTime(long timeoutNanos) {
 if (timeoutNanos <= 0L) {
  return 0L;
 } else {
  long startTime = System.nanoTime();
  return (startTime == 0L) ? 1L : startTime;
 }
}

/**
 * Returns the remaining nanos until the given timeout, or 0L if the timeout has already elapsed.
 * Caller must have previously sanitized timeoutNanos using toSafeNanos.
 */
private static long remainingNanos(long startTime, long timeoutNanos) {
 // assert timeoutNanos == 0L || startTime != 0L;
 // TODO : NOT CORRECT, BUT TESTS PASS ANYWAYS!
 // if (true) return timeoutNanos;
 // ONLY 2 TESTS FAIL IF WE DO:
 // if (true) return 0;
 return (timeoutNanos <= 0L) ? 0L : timeoutNanos - (System.nanoTime() - startTime);
}

 long startTime = System.nanoTime();
methodToTime();
long endTime = System.nanoTime();

long duration = (endTime - startTime);  //divide by 1000000 to get milliseconds.

long now() {
  return System.nanoTime();
}

private void printEvent(String name) {
 long nowNanos = System.nanoTime();
 if (name.equals("callStart")) {
  callStartNanos = nowNanos;
 }
 long elapsedNanos = nowNanos - callStartNanos;
 System.out.printf("%.3f %s%n", elapsedNanos / 1000000000d, name);
}

@Override public void onOpen(WebSocket webSocket, Response response) {
 System.out.println("Executing test case " + number + "/" + count);
 startNanos.set(System.nanoTime());
}

 @Override public Response intercept(Chain chain) throws IOException {
  long t1 = System.nanoTime();
  Request request = chain.request();
  logger.info(String.format("Sending request %s on %s%n%s",
    request.url(), chain.connection(), request.headers()));
  Response response = chain.proceed(request);
  long t2 = System.nanoTime();
  logger.info(String.format("Received response for %s in %.1fms%n%s",
    request.url(), (t2 - t1) / 1e6d, response.headers()));
  return response;
 }
}

private void logWithTime(String message) {
 long timeMs = TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - startNs);
 logger.log("[" + timeMs + " ms] " + message);
}

 @Override public EventListener create(Call call) {
  long callId = nextCallId.getAndIncrement();
  System.out.printf("%04d %s%n", callId, call.request().url());
  return new PrintingEventListener(callId, System.nanoTime());
 }
};

private static int randomIntFrom0to100() {
  // XORShift instead of Math.random http://javamex.com/tutorials/random_numbers/xorshift.shtml
  long x = System.nanoTime();
  x ^= (x << 21);
  x ^= (x >>> 35);
  x ^= (x << 4);
  return Math.abs((int) x % 100);
}

private static int randomIntFrom0to(int max) {
  // XORShift instead of Math.random http://javamex.com/tutorials/random_numbers/xorshift.shtml
  long x = System.nanoTime();
  x ^= (x << 21);
  x ^= (x >>> 35);
  x ^= (x << 4);
  return Math.abs((int) x % max);
}

private static int randomIntFrom0to100() {
  // XORShift instead of Math.random http://javamex.com/tutorials/random_numbers/xorshift.shtml
  long x = System.nanoTime();
  x ^= (x << 21);
  x ^= (x >>> 35);
  x ^= (x << 4);
  return Math.abs((int) x % 100);
}

private static int randomIntFrom0to(int max) {
  // XORShift instead of Math.random http://javamex.com/tutorials/random_numbers/xorshift.shtml
  long x = System.nanoTime();
  x ^= (x << 21);
  x ^= (x >>> 35);
  x ^= (x << 4);
  return Math.abs((int) x % max);
}

/**
 * Returns the number of milliseconds since time given by startNanoTime, which must have been
 * previously returned from a call to {@link System.nanoTime()}.
 */
long millisElapsedSince(long startNanoTime) {
 return NANOSECONDS.toMillis(System.nanoTime() - startNanoTime);
}

@Override
public void callStart(Call call) {
 startNs = System.nanoTime();
 logWithTime("callStart: " + call.request());
}

@Override
public void run() {
 startTime = System.nanoTime();
 try {
  future.get(timeout, unit);
 } catch (Exception e) {
  // nothing
  exception = e;
 } finally {
  timeSpentBlocked = System.nanoTime() - startTime;
 }
}

@Override
public void onComplete() {
  System.out.println("onComplete");
  completeTime.set(System.nanoTime());
  completedLatch.countDown();
}

@Override
public void onComplete() {
  System.out.println("onComplete");
  completeTime.set(System.nanoTime());
  completedLatch.countDown();
}

protected void runTestProfiled() throws Throwable {
 long t0 = System.nanoTime();
 try {
  super.runTest();
 } finally {
  long elapsedMillis = (System.nanoTime() - t0) / (1000L * 1000L);
  if (elapsedMillis >= profileThreshold)
   System.out.printf("%n%s: %d%n", toString(), elapsedMillis);
 }
}