--- jsr166/src/test/tck/SystemTest.java	2015/04/25 04:55:31	1.13
+++ jsr166/src/test/tck/SystemTest.java	2017/05/14 03:09:25	1.14
@@ -27,43 +27,22 @@ public class SystemTest extends JSR166Te
 
     /**
      * Nanos between readings of millis is no longer than millis (plus
-     * possible rounding).
+     * possible rounding), and vice versa.
      * This shows only that nano timing not (much) worse than milli.
      */
-    public void testNanoTime1() throws InterruptedException {
-        long m1 = System.currentTimeMillis();
-        Thread.sleep(1);
-        long n1 = System.nanoTime();
-        Thread.sleep(SHORT_DELAY_MS);
-        long n2 = System.nanoTime();
-        Thread.sleep(1);
-        long m2 = System.currentTimeMillis();
-        long millis = m2 - m1;
-        long nanos = n2 - n1;
-        assertTrue(nanos >= 0);
-        long nanosAsMillis = nanos / 1000000;
-        assertTrue(nanosAsMillis <= millis + MILLIS_ROUND);
-    }
-
-    /**
-     * Millis between readings of nanos is less than nanos, adjusting
-     * for rounding.
-     * This shows only that nano timing not (much) worse than milli.
-     */
-    public void testNanoTime2() throws InterruptedException {
-        long n1 = System.nanoTime();
+    public void testNanoTime() throws InterruptedException {
+        long m0 = System.currentTimeMillis();
+        long n0 = System.nanoTime();
         Thread.sleep(1);
         long m1 = System.currentTimeMillis();
-        Thread.sleep(SHORT_DELAY_MS);
+        long n1 = System.nanoTime();
+        Thread.sleep(50);       // avoid possibly scaled SHORT_DELAY_MS
         long m2 = System.currentTimeMillis();
-        Thread.sleep(1);
         long n2 = System.nanoTime();
-        long millis = m2 - m1;
-        long nanos = n2 - n1;
-
-        assertTrue(nanos >= 0);
-        long nanosAsMillis = nanos / 1000000;
-        assertTrue(millis <= nanosAsMillis + MILLIS_ROUND);
+        Thread.sleep(1);
+        long m3 = System.currentTimeMillis();
+        long n3 = System.nanoTime();
+        assertTrue((n2 - n1) / 1_000_000 <= m3 - m0 + MILLIS_ROUND);
+        assertTrue(m2 - m1 <= (n3 - n0) / 1_000_000 + MILLIS_ROUND);
     }
-
 }