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/*
* 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);
}
}
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