138 lines
4.9 KiB
Java
138 lines
4.9 KiB
Java
/*
|
|
* Copyright (c) 2017, 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.Calendar;
|
|
import java.util.Locale;
|
|
import java.util.SimpleTimeZone;
|
|
import java.util.TimeZone;
|
|
import java.util.function.Supplier;
|
|
|
|
/*
|
|
* @test
|
|
* @bug 8191216
|
|
* @summary test that provokes race between cloning and lazily initializing
|
|
* SimpleTimeZone cache fields
|
|
*/
|
|
public class SimpleTimeZoneCloneRaceTest {
|
|
|
|
public static void main(String[] args) throws InterruptedException {
|
|
|
|
// shared TZ user repeatedly samples sharedTZ and calculates offset
|
|
// using the shared instance
|
|
TimeZoneUser sharedTZuser = new TimeZoneUser(() -> sharedTZ);
|
|
|
|
// cloned TZ user repeatedly samples sharedTZ then clones it and
|
|
// calculates offset using the clone...
|
|
TimeZoneUser clonedTZuser = new TimeZoneUser(() -> {
|
|
// sample shared TZ
|
|
TimeZone tz = sharedTZ;
|
|
// do some computation that takes roughly the same time as it takes
|
|
// sharedTZUser to start changing cache fields in shared TZ
|
|
cpuHogTZ.getOffset(time);
|
|
// now clone the sampled TZ and return it, hoping the clone is done
|
|
// at about the right time....
|
|
return (TimeZone) tz.clone();
|
|
});
|
|
|
|
// start threads
|
|
Thread t1 = new Thread(sharedTZuser);
|
|
Thread t2 = new Thread(clonedTZuser);
|
|
t1.start();
|
|
t2.start();
|
|
|
|
// plant new SimpleTimeZone instances for 2 seconds
|
|
long t0 = System.currentTimeMillis();
|
|
do {
|
|
TimeZone tz1 = createSTZ();
|
|
TimeZone tz2 = createSTZ();
|
|
cpuHogTZ = tz1;
|
|
sharedTZ = tz2;
|
|
} while (System.currentTimeMillis() - t0 < 2000L);
|
|
|
|
sharedTZuser.stop = true;
|
|
clonedTZuser.stop = true;
|
|
t1.join();
|
|
t2.join();
|
|
|
|
System.out.println(
|
|
String.format("shared TZ: %d correct, %d incorrect calculations",
|
|
sharedTZuser.correctCount, sharedTZuser.incorrectCount)
|
|
);
|
|
System.out.println(
|
|
String.format("cloned TZ: %d correct, %d incorrect calculations",
|
|
clonedTZuser.correctCount, clonedTZuser.incorrectCount)
|
|
);
|
|
if (clonedTZuser.incorrectCount > 0) {
|
|
throw new RuntimeException(clonedTZuser.incorrectCount +
|
|
" fatal data races detected");
|
|
}
|
|
}
|
|
|
|
static SimpleTimeZone createSTZ() {
|
|
return new SimpleTimeZone(-28800000,
|
|
"America/Los_Angeles",
|
|
Calendar.APRIL, 1, -Calendar.SUNDAY,
|
|
7200000,
|
|
Calendar.OCTOBER, -1, Calendar.SUNDAY,
|
|
7200000,
|
|
3600000);
|
|
}
|
|
|
|
static volatile TimeZone cpuHogTZ = createSTZ();
|
|
static volatile TimeZone sharedTZ = createSTZ();
|
|
static final long time;
|
|
static final long correctOffset;
|
|
|
|
static {
|
|
TimeZone tz = createSTZ();
|
|
Calendar cal = Calendar.getInstance(tz, Locale.ROOT);
|
|
cal.set(2000, Calendar.MAY, 1, 0, 0, 0);
|
|
time = cal.getTimeInMillis();
|
|
correctOffset = tz.getOffset(time);
|
|
}
|
|
|
|
static class TimeZoneUser implements Runnable {
|
|
private final Supplier<? extends TimeZone> tzSupplier;
|
|
|
|
TimeZoneUser(Supplier<? extends TimeZone> tzSupplier) {
|
|
this.tzSupplier = tzSupplier;
|
|
}
|
|
|
|
volatile boolean stop;
|
|
int correctCount, incorrectCount;
|
|
|
|
@Override
|
|
public void run() {
|
|
while (!stop) {
|
|
TimeZone tz = tzSupplier.get();
|
|
int offset = tz.getOffset(time);
|
|
if (offset == correctOffset) {
|
|
correctCount++;
|
|
} else {
|
|
incorrectCount++;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|