--- jsr166/src/test/tck/SystemTest.java 2003/08/31 19:24:55 1.1 +++ jsr166/src/test/tck/SystemTest.java 2003/09/14 20:42:41 1.2 @@ -7,7 +7,7 @@ import junit.framework.*; -public class SystemTest extends TestCase { +public class SystemTest extends JSR166TestCase { public static void main(String[] args) { junit.textui.TestRunner.run(suite()); } @@ -16,55 +16,52 @@ public class SystemTest extends TestCase return new TestSuite(SystemTest.class); } + /** + * Nanos between readings of millis is no longer than millis. + * This shows only that nano timing not (much) worse than milli. + */ public void testNanoTime1() { - // Nanos between readings of millis must be no longer than millis - long m1 = System.currentTimeMillis(); - long n1 = System.nanoTime(); - - // Ensure some computation that is not optimized away. - long sum = 0; - for (long i = 1; i < 10000; ++i) - sum += i; - assertTrue(sum != 0); - - long n2 = System.nanoTime(); - - for (long i = 1; i < 10000; ++i) - sum -= i; - assertTrue(sum == 0); - - long m2 = System.currentTimeMillis(); - long millis = m2 - m1; - long nanos = n2 - n1; - - assertTrue(nanos >= 0); - assertTrue(nanos <= millis * 1000000); + try { + 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); + assertTrue(nanos <= millis * 1000000); + } + catch(InterruptedException ie) { + fail("unexpected exception"); + } } + /** + * Millis between readings of nanos is no longer than nanos + * This shows only that nano timing not (much) worse than milli. + */ public void testNanoTime2() { - // Millis between readings of nanos must be no longer than nanos - long n1 = System.nanoTime(); - long m1 = System.currentTimeMillis(); - - // Ensure some computation that is not optimized away. - long sum = 0; - for (long i = 1; i < 10000; ++i) - sum += i; - assertTrue(sum != 0); - - long m2 = System.currentTimeMillis(); - - for (long i = 1; i < 10000; ++i) - sum -= i; - assertTrue(sum == 0); - - long n2 = System.nanoTime(); - - long millis = m2 - m1; - long nanos = n2 - n1; - - assertTrue(nanos >= 0); - assertTrue(millis * 1000000 <= nanos); + try { + long n1 = System.nanoTime(); + Thread.sleep(1); + long m1 = System.currentTimeMillis(); + Thread.sleep(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); + assertTrue(millis * 1000000 <= nanos); + } + catch(InterruptedException ie) { + fail("unexpected exception"); + } } }