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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 TestUncommit
* @requires vm.gc.Z
* @summary Test ZGC uncommit unused memory
* @library /test/lib
* @run main/othervm -XX:+UseZGC -Xlog:gc*,gc+heap=debug,gc+stats=off -Xms128M -Xmx512M -XX:ZUncommitDelay=10 gc.z.TestUncommit
*/
import java.util.ArrayList;
import jdk.test.lib.Utils;
public class TestUncommit {
private static final int delay = 10 * 1000; // milliseconds
private static final int allocSize = 200 * 1024 * 1024; // 200M
private static final int smallObjectSize = 4 * 1024; // 4K
private static final int mediumObjectSize = 2 * 1024 * 1024; // 2M
private static final int largeObjectSize = allocSize;
private static volatile ArrayList<byte[]> keepAlive;
private static final long startTime = System.nanoTime();
private static void log(String msg) {
final String elapsedSeconds = String.format("%.3fs", (System.nanoTime() - startTime) / 1_000_000_000.0);
System.out.println("[" + elapsedSeconds + "] (" + Thread.currentThread().getName() + ") " + msg);
}
private static long capacity() {
return Runtime.getRuntime().totalMemory();
}
private static void allocate(int objectSize) {
keepAlive = new ArrayList<>();
for (int i = 0; i < allocSize; i+= objectSize) {
keepAlive.add(new byte[objectSize]);
}
}
private static void reclaim() {
keepAlive = null;
System.gc();
}
private static void test(int objectSize) throws Exception {
final var beforeAlloc = capacity();
final var timeBeforeAlloc = System.nanoTime();
// Allocate memory
log("Allocating");
allocate(objectSize);
final var afterAlloc = capacity();
// Reclaim memory
log("Reclaiming");
reclaim();
log("Waiting for uncommit to start");
while (capacity() >= afterAlloc) {
Thread.sleep(1000);
}
log("Uncommit started");
final var timeUncommitStart = System.nanoTime();
final var actualDelay = (timeUncommitStart - timeBeforeAlloc) / 1_000_000;
log("Waiting for uncommit to complete");
while (capacity() > beforeAlloc) {
Thread.sleep(1000);
}
log("Uncommit completed");
final var afterUncommit = capacity();
log(" Uncommit Delay: " + delay);
log(" Object Size: " + objectSize);
log(" Alloc Size: " + allocSize);
log(" Before Alloc: " + beforeAlloc);
log(" After Alloc: " + afterAlloc);
log(" After Uncommit: " + afterUncommit);
log(" Actual Uncommit Delay: " + actualDelay);
// Verify
if (actualDelay < delay) {
throw new Exception("Uncommitted too fast");
}
if (actualDelay > delay * 2 * Utils.TIMEOUT_FACTOR) {
throw new Exception("Uncommitted too slow");
}
if (afterUncommit < beforeAlloc) {
throw new Exception("Uncommitted too much");
}
if (afterUncommit > beforeAlloc) {
throw new Exception("Uncommitted too little");
}
log("Success");
}
public static void main(String[] args) throws Exception {
for (int i = 0; i < 2; i++) {
log("Iteration " + i);
test(smallObjectSize);
test(mediumObjectSize);
test(largeObjectSize);
}
}
}
¤ Dauer der Verarbeitung: 0.21 Sekunden
(vorverarbeitet)
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