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/*
* Copyright (c) 2019, 2020, 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.
*/
package gc.z;
/*
* @test TestHighUsage
* @requires vm.gc.Z
* @summary Test ZGC "High Usage" rule
* @library /test/lib
* @run main/othervm gc.z.TestHighUsage
*/
import java.util.LinkedList;
import jdk.test.lib.process.ProcessTools;
public class TestHighUsage {
static class Test {
private static final int K = 1024;
private static final int M = K * K;
private static final long maxCapacity = Runtime.getRuntime().maxMemory();
private static final long slowAllocationThreshold = 16 * M;
private static final long highUsageThreshold = maxCapacity / 20; // 5%
private static volatile LinkedList<byte[]> keepAlive;
private static volatile Object dummy;
public static void main(String[] args) throws Exception {
System.out.println("Max capacity: " + (maxCapacity / M) + "M");
System.out.println("High usage threshold: " + (highUsageThreshold / M) + "M");
System.out.println("Allocating live-set");
// Allocate live-set
keepAlive = new LinkedList<>();
while (Runtime.getRuntime().freeMemory() > slowAllocationThreshold) {
while (Runtime.getRuntime().freeMemory() > slowAllocationThreshold) {
keepAlive.add(new byte[128 * K]);
}
// Compact live-set and let allocation rate settle down
System.gc();
Thread.sleep(2000);
}
System.out.println("Allocating garbage slowly");
// Allocate garbage slowly, so that the sampled allocation rate on average
// becomes zero MB/s for the last 1 second windows. Once we reach the high
// usage threshold we idle to allow for a "High Usage" GC cycle to happen.
// We need to allocate slowly to avoid an "Allocation Rate" GC cycle.
for (int i = 0; i < 300; i++) {
if (Runtime.getRuntime().freeMemory() > highUsageThreshold) {
// Allocate
dummy = new byte[128 * K];
System.out.println("Free: " + (Runtime.getRuntime().freeMemory() / M) + "M (Allocating)");
} else {
// Idle
System.out.println("Free: " + (Runtime.getRuntime().freeMemory() / M) + "M (Idling)");
}
Thread.sleep(250);
}
System.out.println("Done");
}
}
public static void main(String[] args) throws Exception {
ProcessTools.executeTestJvm("-XX:+UseZGC",
"-XX:-ZProactive",
"-Xms128M",
"-Xmx128M",
"-XX:ParallelGCThreads=1",
"-XX:ConcGCThreads=1",
"-Xlog:gc,gc+start",
Test.class.getName())
.shouldNotContain("Allocation Stall")
.shouldContain("High Usage")
.shouldHaveExitValue(0);
}
}
¤ Dauer der Verarbeitung: 0.20 Sekunden
(vorverarbeitet)
¤
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