--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/test/sun/misc/VM/GetNanoTimeAdjustment.java Wed Jan 28 17:48:59 2015 +0100
@@ -0,0 +1,249 @@
+/*
+ * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
+ * 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.
+ */
+import java.util.Objects;
+import sun.misc.VM;
+
+/**
+ * @test
+ * @bug 8068730
+ * @summary tests that VM.getgetNanoTimeAdjustment() works as expected.
+ * @run main GetNanoTimeAdjustment
+ * @author danielfuchs
+ */
+public class GetNanoTimeAdjustment {
+
+ static final int MILLIS_IN_SECOND = 1000;
+ static final int NANOS_IN_MILLI = 1000_000;
+ static final int NANOS_IN_MICRO = 1000;
+ static final int NANOS_IN_SECOND = 1000_000_000;
+
+ static final boolean verbose = true;
+
+ static final class TestAssertException extends RuntimeException {
+ TestAssertException(String msg) { super(msg); }
+ }
+
+ private static void assertEquals(long expected, long received, String msg) {
+ if (expected != received) {
+ throw new TestAssertException("Unexpected result for " + msg
+ + ".\n\texpected: " + expected
+ + "\n\tactual: " + received);
+ } else if (verbose) {
+ System.out.println("Got expected " + msg + ": " + received);
+ }
+ }
+
+ private static void assertEquals(Object expected, Object received, String msg) {
+ if (!Objects.equals(expected, received)) {
+ throw new TestAssertException("Unexpected result for " + msg
+ + ".\n\texpected: " + expected
+ + "\n\tactual: " + received);
+ } else if (verbose) {
+ System.out.println("Got expected " + msg + ": " + received);
+ }
+ }
+
+ static final long MAX_OFFSET = 0x0100000000L;
+ static final long MIN_OFFSET = -MAX_OFFSET;
+ static enum Answer {
+ YES, // isOffLimit = YES: we must get -1
+ NO, // isOffLimit = NO: we must not not get -1
+ MAYBE // isOffLimit = MAYBE: we might get -1 or a valid adjustment.
+ };
+ static long distance(long one, long two) {
+ return one > two ? Math.subtractExact(one, two)
+ : Math.subtractExact(two, one);
+ }
+
+
+ static Answer isOffLimits(long before, long after, long offset) {
+ long relativeDistanceBefore = distance(before, offset);
+ long relativeDistanceAfter = distance(after, offset);
+ if (relativeDistanceBefore >= MAX_OFFSET && relativeDistanceAfter >= MAX_OFFSET) {
+ return Answer.YES;
+ }
+ if (relativeDistanceBefore < MAX_OFFSET && relativeDistanceAfter < MAX_OFFSET) {
+ if (relativeDistanceBefore == 0 || relativeDistanceAfter == 0) {
+ return Answer.MAYBE; // unlucky case where
+ }
+ return Answer.NO;
+ }
+ return Answer.MAYBE;
+ }
+
+ static void testWithOffset(String name, long offset) {
+ System.out.println("Testing with offset: " + name);
+ long beforeMillis = System.currentTimeMillis();
+ long adjustment = VM.getNanoTimeAdjustment(offset);
+ long afterMillis = System.currentTimeMillis();
+
+ if (offset >= beforeMillis/MILLIS_IN_SECOND
+ && offset <= afterMillis/MILLIS_IN_SECOND) {
+ if (adjustment == -1) {
+ // it's possible that we have fallen in the unlucky case
+ // where -1 was the genuine result. let's go backward a bit.
+ offset = offset - 10;
+ beforeMillis = System.currentTimeMillis();
+ adjustment = VM.getNanoTimeAdjustment(offset);
+ afterMillis = System.currentTimeMillis();
+ if (adjustment == -1) {
+ throw new RuntimeException(name + ": VM says " + offset
+ + " secs is too far off, "
+ + " when time in seconds is in ["
+ + beforeMillis/MILLIS_IN_SECOND + ", "
+ + afterMillis/MILLIS_IN_SECOND
+ + "]");
+ }
+ }
+ }
+
+ Answer isOffLimit = isOffLimits(beforeMillis/MILLIS_IN_SECOND,
+ afterMillis/MILLIS_IN_SECOND, offset);
+ switch (isOffLimit) {
+ case YES:
+ if (adjustment != -1) {
+ throw new RuntimeException(name
+ + ": VM should have returned -1 for "
+ + offset
+ + " when time in seconds is in ["
+ + beforeMillis/MILLIS_IN_SECOND + ", "
+ + afterMillis/MILLIS_IN_SECOND + "]");
+ }
+ System.out.println("Got expected exception value: " + adjustment);
+ break;
+ case NO:
+ if (adjustment == -1) {
+ throw new RuntimeException(name
+ + "VM says " + offset
+ + " secs is too far off, "
+ + " when time in seconds is in ["
+ + beforeMillis/MILLIS_IN_SECOND + ", "
+ + afterMillis/MILLIS_IN_SECOND
+ + "]");
+ }
+ break;
+ case MAYBE:
+ System.out.println("Adjustment: " + adjustment);
+ System.out.println("Can't assert for -1 with offset "
+ + offset + "(" + name + ")"
+ + " when time in seconds is in ["
+ + beforeMillis/MILLIS_IN_SECOND + ", "
+ + afterMillis/MILLIS_IN_SECOND
+ + "]");
+ // not conclusive
+ }
+
+ if (isOffLimit == Answer.NO || adjustment != -1) {
+ System.out.println("Validating adjustment: " + adjustment);
+ long expectedMax = distance(offset, beforeMillis/MILLIS_IN_SECOND)
+ * NANOS_IN_SECOND
+ + (beforeMillis % MILLIS_IN_SECOND) * NANOS_IN_MILLI
+ + (afterMillis - beforeMillis + 1) * NANOS_IN_MILLI;
+ long absoluteAdjustment = distance(0, adjustment);
+ if (absoluteAdjustment > expectedMax) {
+ long adjSec = absoluteAdjustment / NANOS_IN_SECOND;
+ long adjMil = (absoluteAdjustment % NANOS_IN_SECOND) / NANOS_IN_MILLI;
+ long adjMic = (absoluteAdjustment % NANOS_IN_MILLI) / NANOS_IN_MICRO;
+ long adjNan = (absoluteAdjustment % NANOS_IN_MICRO);
+ long expSec = expectedMax / NANOS_IN_SECOND;
+ long expMil = (expectedMax % NANOS_IN_SECOND) / NANOS_IN_MILLI;
+ long expMic = (expectedMax % NANOS_IN_MILLI) / NANOS_IN_MICRO;
+ long expNan = (expectedMax % NANOS_IN_MICRO);
+ System.err.println("Excessive adjustment: " + adjSec + "s, "
+ + adjMil + "ms, " + adjMic + "mics, " + adjNan + "ns");
+ System.err.println("Epected max: " + expSec + "s, "
+ + expMil + "ms, " + expMic + "mics, " + expNan + "ns");
+
+ throw new RuntimeException(name
+ + ": Excessive adjustment: " + adjustment
+ + " when time in millis is in ["
+ + beforeMillis + ", " + afterMillis
+ + "] and offset in seconds is " + offset);
+ }
+ }
+
+ }
+
+ static void regular() {
+ System.out.println("*** Testing regular cases ***");
+ final long start = System.currentTimeMillis();
+ long offset = start/1000;
+ long adjustment = VM.getNanoTimeAdjustment(offset);
+ if (start != offset*1000) {
+ if (adjustment == -1) {
+ throw new RuntimeException("VM says " + offset
+ + " secs is too far off, but time millis is "
+ + System.currentTimeMillis());
+ }
+ }
+ if (adjustment == -1) {
+ offset = System.currentTimeMillis()/1000 - 1024;
+ adjustment = VM.getNanoTimeAdjustment(offset);
+ if (adjustment == -1) {
+ throw new RuntimeException("VM says " + offset
+ + " secs is too far off, but time millis is "
+ + System.currentTimeMillis());
+ }
+ }
+ if (adjustment > (start/1000 - offset + 20)*NANOS_IN_SECOND) {
+ throw new RuntimeException("Excessive adjustment: " + adjustment);
+ }
+ testWithOffset("System.currentTimeMillis()/1000",
+ System.currentTimeMillis()/1000);
+ testWithOffset("System.currentTimeMillis()/1000 - 1024",
+ System.currentTimeMillis()/1000 - 1024);
+ testWithOffset("System.currentTimeMillis()/1000 + 1024",
+ System.currentTimeMillis()/1000 + 1024);
+ }
+
+ static void testLimits() {
+ System.out.println("*** Testing limits ***");
+ testWithOffset("System.currentTimeMillis()/1000 - MAX_OFFSET + 1",
+ System.currentTimeMillis()/1000 - MAX_OFFSET + 1);
+ testWithOffset("System.currentTimeMillis()/1000 + MAX_OFFSET - 1",
+ System.currentTimeMillis()/1000 + MAX_OFFSET - 1);
+ testWithOffset("System.currentTimeMillis()/1000 - MAX_OFFSET",
+ System.currentTimeMillis()/1000 - MAX_OFFSET);
+ testWithOffset("System.currentTimeMillis()/1000 + MAX_OFFSET",
+ System.currentTimeMillis()/1000 + MAX_OFFSET);
+ testWithOffset("System.currentTimeMillis()/1000 - MAX_OFFSET - 1024",
+ System.currentTimeMillis()/1000 - MAX_OFFSET - 1024);
+ testWithOffset("System.currentTimeMillis()/1000 + MAX_OFFSET + 1024",
+ System.currentTimeMillis()/1000 + MAX_OFFSET + 1024);
+ testWithOffset("0", 0);
+ testWithOffset("-1", -1);
+ testWithOffset("Integer.MAX_VALUE + System.currentTimeMillis()/1000",
+ ((long)Integer.MAX_VALUE) + System.currentTimeMillis()/1000);
+ testWithOffset("System.currentTimeMillis()/1000 - Integer.MIN_VALUE",
+ System.currentTimeMillis()/1000 - Integer.MIN_VALUE);
+ testWithOffset("Long.MAX_VALUE", Long.MAX_VALUE);
+ testWithOffset("System.currentTimeMillis()/1000 - Long.MIN_VALUE",
+ (Long.MIN_VALUE + System.currentTimeMillis()/1000)*-1);
+ }
+
+ public static void main(String[] args) throws Exception {
+ regular();
+ testLimits();
+ }
+
+}