| /* |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| /* |
| * This file is available under and governed by the GNU General Public |
| * License version 2 only, as published by the Free Software Foundation. |
| * However, the following notice accompanied the original version of this |
| * file: |
| * |
| * Written by Doug Lea with assistance from members of JCP JSR-166 |
| * Expert Group and released to the public domain, as explained at |
| * http://creativecommons.org/publicdomain/zero/1.0/ |
| * Other contributors include Andrew Wright, Jeffrey Hayes, |
| * Pat Fisher, Mike Judd. |
| */ |
| |
| import junit.framework.Test; |
| import junit.framework.TestSuite; |
| |
| public class SystemTest extends JSR166TestCase { |
| public static void main(String[] args) { |
| main(suite(), args); |
| } |
| |
| public static Test suite() { |
| return new TestSuite(SystemTest.class); |
| } |
| |
| /** |
| * Worst case rounding for millisecs; set for 60 cycle millis clock. |
| * This value might need to be changed on JVMs with coarser |
| * System.currentTimeMillis clocks. |
| */ |
| static final long MILLIS_ROUND = 17; |
| |
| /** |
| * Nanos between readings of millis is no longer than millis (plus |
| * possible rounding), and vice versa. |
| * This shows only that nano timing not (much) worse than milli. |
| */ |
| public void testNanoTime() throws InterruptedException { |
| long m0 = System.currentTimeMillis(); |
| long n0 = System.nanoTime(); |
| Thread.sleep(1); |
| long m1 = System.currentTimeMillis(); |
| long n1 = System.nanoTime(); |
| Thread.sleep(50); // avoid possibly scaled SHORT_DELAY_MS |
| long m2 = System.currentTimeMillis(); |
| long n2 = System.nanoTime(); |
| 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); |
| } |
| } |