8145908: [Newtest] Multi-threading stress test for G1 Remembered Sets
Reviewed-by: tschatzl, mchernov
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/stress/gc/TestMultiThreadStressRSet.java Tue Mar 01 20:30:28 2016 +0400
@@ -0,0 +1,305 @@
+/*
+ * Copyright (c) 2016, 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.io.PrintStream;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.Random;
+import sun.hotspot.WhiteBox;
+
+/*
+ * @test TestMultiThreadStressRSet.java
+ * @key stress
+ * @requires vm.gc=="G1" | vm.gc=="null"
+ * @requires os.maxMemory > 2G
+ *
+ * @summary Stress G1 Remembered Set using multiple threads
+ * @library /test/lib /testlibrary
+ * @build sun.hotspot.WhiteBox
+ * @run main ClassFileInstaller sun.hotspot.WhiteBox
+ * sun.hotspot.WhiteBox$WhiteBoxPermission
+ * @run main/othervm -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI
+ * -XX:+UseG1GC -XX:G1SummarizeRSetStatsPeriod=1 -Xlog:gc
+ * -Xmx500m -XX:G1HeapRegionSize=1m -XX:MaxGCPauseMillis=1000 TestMultiThreadStressRSet 10 4
+ *
+ * @run main/othervm -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI
+ * -XX:+UseG1GC -XX:G1SummarizeRSetStatsPeriod=100 -Xlog:gc
+ * -Xmx1G -XX:G1HeapRegionSize=8m -XX:MaxGCPauseMillis=1000 TestMultiThreadStressRSet 60 16
+ *
+ * @run main/othervm/timeout=700 -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI
+ * -XX:+UseG1GC -XX:G1SummarizeRSetStatsPeriod=100 -Xlog:gc
+ * -Xmx500m -XX:G1HeapRegionSize=1m -XX:MaxGCPauseMillis=1000 TestMultiThreadStressRSet 600 32
+ */
+public class TestMultiThreadStressRSet {
+
+ private static final Random RND = new Random(2015 * 2016);
+ private static final WhiteBox WB = WhiteBox.getWhiteBox();
+ private static final int REF_SIZE = WB.getHeapOopSize();
+ private static final int REGION_SIZE = WB.g1RegionSize();
+
+ // How many regions to use for the storage
+ private static final int STORAGE_REGIONS = 20;
+
+ // Size a single obj in the storage
+ private static final int OBJ_SIZE = 1024;
+
+ // How many regions of young/old gen to use in the BUFFER
+ private static final int BUFFER_YOUNG_REGIONS = 60;
+ private static final int BUFFER_OLD_REGIONS = 40;
+
+ // Total number of objects in the storage.
+ private final int N;
+
+ // The storage of byte[]
+ private final List<Object> STORAGE;
+
+ // Where references to the Storage will be stored
+ private final List<Object[]> BUFFER;
+
+ // The length of a buffer element.
+ // RSet deals with "cards" (areas of 512 bytes), not with single refs
+ // So, to affect the RSet the BUFFER refs should be allocated in different
+ // memory cards.
+ private final int BUF_ARR_LEN = 100 * (512 / REF_SIZE);
+
+ // Total number of objects in the young/old buffers
+ private final int YOUNG;
+ private final int OLD;
+
+ // To cause Remembered Sets change their coarse level the test uses a window
+ // within STORAGE. All the BUFFER elements refer to only STORAGE objects
+ // from the current window. The window is defined by a range.
+ // The first element has got the index: 'windowStart',
+ // the last one: 'windowStart + windowSize - 1'
+ // The window is shifting periodically.
+ private int windowStart;
+ private final int windowSize;
+
+ // Counter of created worker threads
+ private int counter = 0;
+
+ private volatile String errorMessage = null;
+ private volatile boolean isEnough = false;
+
+ public static void main(String args[]) {
+ if (args.length != 2) {
+ throw new IllegalArgumentException("TEST BUG: wrong arg count " + args.length);
+ }
+ long time = Long.parseLong(args[0]);
+ int threads = Integer.parseInt(args[1]);
+ new TestMultiThreadStressRSet().test(time * 1000, threads);
+ }
+
+ /**
+ * Initiates test parameters, fills out the STORAGE and BUFFER.
+ */
+ public TestMultiThreadStressRSet() {
+
+ N = (REGION_SIZE - 1) * STORAGE_REGIONS / OBJ_SIZE + 1;
+ STORAGE = new ArrayList<>(N);
+ int bytes = OBJ_SIZE - 20;
+ for (int i = 0; i < N - 1; i++) {
+ STORAGE.add(new byte[bytes]);
+ }
+ STORAGE.add(new byte[REGION_SIZE / 2 + 100]); // humongous
+ windowStart = 0;
+ windowSize = REGION_SIZE / OBJ_SIZE;
+
+ BUFFER = new ArrayList<>();
+ int sizeOfBufferObject = 20 + REF_SIZE * BUF_ARR_LEN;
+ OLD = REGION_SIZE * BUFFER_OLD_REGIONS / sizeOfBufferObject;
+ YOUNG = REGION_SIZE * BUFFER_YOUNG_REGIONS / sizeOfBufferObject;
+ for (int i = 0; i < OLD + YOUNG; i++) {
+ BUFFER.add(new Object[BUF_ARR_LEN]);
+ }
+ }
+
+ /**
+ * Does the testing. Steps:
+ * <ul>
+ * <li> starts the Shifter thread
+ * <li> during the given time starts new Worker threads, keeping the number
+ * of live thread under limit.
+ * <li> stops the Shifter thread
+ * </ul>
+ *
+ * @param timeInMillis how long to stress
+ * @param maxThreads the maximum number of Worker thread working together.
+ */
+ public void test(long timeInMillis, int maxThreads) {
+ if (timeInMillis <= 0 || maxThreads <= 0) {
+ throw new IllegalArgumentException("TEST BUG: be positive!");
+ }
+ System.out.println("%% Time to work: " + timeInMillis / 1000 + "s");
+ System.out.println("%% Number of threads: " + maxThreads);
+ long finish = System.currentTimeMillis() + timeInMillis;
+ Shifter shift = new Shifter(this, 1000, (int) (windowSize * 0.9));
+ shift.start();
+ for (int i = 0; i < maxThreads; i++) {
+ new Worker(this, 100).start();
+ }
+ try {
+ while (System.currentTimeMillis() < finish && errorMessage == null) {
+ Thread.sleep(100);
+ }
+ } catch (Throwable t) {
+ printAllStackTraces(System.err);
+ t.printStackTrace(System.err);
+ this.errorMessage = t.getMessage();
+ } finally {
+ isEnough = true;
+ }
+ System.out.println("%% Total work cycles: " + counter);
+ if (errorMessage != null) {
+ throw new RuntimeException(errorMessage);
+ }
+ }
+
+ /**
+ * Returns an element from from the BUFFER (an object array) to keep
+ * references to the storage.
+ *
+ * @return an Object[] from buffer.
+ */
+ private Object[] getFromBuffer() {
+ int index = counter % (OLD + YOUNG);
+ synchronized (BUFFER) {
+ if (index < OLD) {
+ if (counter % 100 == (counter / 100) % 100) {
+ // need to generate garbage in the old gen to provoke mixed GC
+ return replaceInBuffer(index);
+ } else {
+ return BUFFER.get(index);
+ }
+ } else {
+ return replaceInBuffer(index);
+ }
+ }
+ }
+
+ private Object[] replaceInBuffer(int index) {
+ Object[] objs = new Object[BUF_ARR_LEN];
+ BUFFER.set(index, objs);
+ return objs;
+ }
+
+ /**
+ * Returns a random object from the current window within the storage.
+ * A storage element with index from windowStart to windowStart+windowSize.
+ *
+ * @return a random element from the current window within the storage.
+ */
+ private Object getRandomObject() {
+ int index = (windowStart + RND.nextInt(windowSize)) % N;
+ return STORAGE.get(index);
+ }
+
+ private static void printAllStackTraces(PrintStream ps) {
+ Map<Thread, StackTraceElement[]> traces = Thread.getAllStackTraces();
+ for (Thread t : traces.keySet()) {
+ ps.println(t.toString() + " " + t.getState());
+ for (StackTraceElement traceElement : traces.get(t)) {
+ ps.println("\tat " + traceElement);
+ }
+ }
+ }
+
+ /**
+ * Thread to create a number of references from BUFFER to STORAGE.
+ */
+ private static class Worker extends Thread {
+
+ final TestMultiThreadStressRSet boss;
+ final int refs; // number of refs to OldGen
+
+ /**
+ * @param boss the tests
+ * @param refsToOldGen how many references to the OldGen to create
+ */
+ Worker(TestMultiThreadStressRSet boss, int refsToOldGen) {
+ this.boss = boss;
+ this.refs = refsToOldGen;
+ }
+
+ @Override
+ public void run() {
+ try {
+ while (!boss.isEnough) {
+ Object[] objs = boss.getFromBuffer();
+ int step = objs.length / refs;
+ for (int i = 0; i < refs; i += step) {
+ objs[i] = boss.getRandomObject();
+ }
+ boss.counter++;
+ }
+ } catch (Throwable t) {
+ t.printStackTrace(System.out);
+ boss.errorMessage = t.getMessage();
+ }
+ }
+ }
+
+ /**
+ * Periodically shifts the current STORAGE window, removing references
+ * in BUFFER that refer to objects outside the window.
+ */
+ private static class Shifter extends Thread {
+
+ final TestMultiThreadStressRSet boss;
+ final int sleepTime;
+ final int shift;
+
+ Shifter(TestMultiThreadStressRSet boss, int sleepTime, int shift) {
+ this.boss = boss;
+ this.sleepTime = sleepTime;
+ this.shift = shift;
+ }
+
+ @Override
+ public void run() {
+ try {
+ while (!boss.isEnough) {
+ Thread.sleep(sleepTime);
+ boss.windowStart += shift;
+ for (int i = 0; i < boss.OLD; i++) {
+ Object[] objs = boss.BUFFER.get(i);
+ for (int j = 0; j < objs.length; j++) {
+ objs[j] = null;
+ }
+ }
+ if (!WB.g1InConcurrentMark()) {
+ System.out.println("%% start CMC");
+ WB.g1StartConcMarkCycle();
+ } else {
+ System.out.println("%% CMC is already in progress");
+ }
+ }
+ } catch (Throwable t) {
+ t.printStackTrace(System.out);
+ boss.errorMessage = t.getMessage();
+ }
+ }
+ }
+}
+