Skip to content
Permalink
Browse files
8262122: [TESTBUG] Shenandoah-specific variant of TestReferenceRefersTo
Reviewed-by: shade
  • Loading branch information
rkennke committed Mar 4, 2021
1 parent a777e82 commit 222a17ef7799743a2b92115dbb1760eec92ca46b
Showing 1 changed file with 325 additions and 0 deletions.
@@ -0,0 +1,325 @@
/*
* Copyright (c) 2020, 2021 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.shenandoah;

/* @test
* @requires vm.gc.Shenandoah
* @library /test/lib
* @build sun.hotspot.WhiteBox
* @modules java.base
* @run main ClassFileInstaller sun.hotspot.WhiteBox
* @run main/othervm
* -Xbootclasspath/a:.
* -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI
* -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:ShenandoahGCMode=satb
* gc.shenandoah.TestReferenceRefersToShenandoah
*/

/* @test
* @requires vm.gc.Shenandoah
* @library /test/lib
* @build sun.hotspot.WhiteBox
* @modules java.base
* @run main ClassFileInstaller sun.hotspot.WhiteBox
* @run main/othervm
* -Xbootclasspath/a:.
* -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI
* -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:ShenandoahGCMode=iu
* gc.shenandoah.TestReferenceRefersToShenandoah
*/

import java.lang.ref.PhantomReference;
import java.lang.ref.Reference;
import java.lang.ref.ReferenceQueue;
import java.lang.ref.WeakReference;
import sun.hotspot.WhiteBox;

public class TestReferenceRefersToShenandoah {
private static final WhiteBox WB = WhiteBox.getWhiteBox();

private static final class TestObject {
public final int value;

public TestObject(int value) {
this.value = value;
}
}

private static volatile TestObject testObjectNone = null;
private static volatile TestObject testObject1 = null;
private static volatile TestObject testObject2 = null;
private static volatile TestObject testObject3 = null;
private static volatile TestObject testObject4 = null;

private static ReferenceQueue<TestObject> queue = null;

private static PhantomReference<TestObject> testPhantom1 = null;

private static WeakReference<TestObject> testWeak2 = null;
private static WeakReference<TestObject> testWeak3 = null;
private static WeakReference<TestObject> testWeak4 = null;

private static void setup() {
testObjectNone = new TestObject(0);
testObject1 = new TestObject(1);
testObject2 = new TestObject(2);
testObject3 = new TestObject(3);
testObject4 = new TestObject(4);

queue = new ReferenceQueue<TestObject>();

testPhantom1 = new PhantomReference<TestObject>(testObject1, queue);

testWeak2 = new WeakReference<TestObject>(testObject2, queue);
testWeak3 = new WeakReference<TestObject>(testObject3, queue);
testWeak4 = new WeakReference<TestObject>(testObject4, queue);
}

private static void gcUntilOld(Object o) throws Exception {
if (!WB.isObjectInOldGen(o)) {
WB.fullGC();
if (!WB.isObjectInOldGen(o)) {
fail("object not promoted by full gc");
}
}
}

private static void gcUntilOld() throws Exception {
gcUntilOld(testObjectNone);
gcUntilOld(testObject1);
gcUntilOld(testObject2);
gcUntilOld(testObject3);
gcUntilOld(testObject4);

gcUntilOld(testPhantom1);

gcUntilOld(testWeak2);
gcUntilOld(testWeak3);
gcUntilOld(testWeak4);
}

private static void progress(String msg) {
System.out.println(msg);
}

private static void fail(String msg) throws Exception {
throw new RuntimeException(msg);
}

private static void expectCleared(Reference<TestObject> ref,
String which) throws Exception {
expectNotValue(ref, testObjectNone, which);
if (!ref.refersTo(null)) {
fail("expected " + which + " to be cleared");
}
}

private static void expectNotCleared(Reference<TestObject> ref,
String which) throws Exception {
expectNotValue(ref, testObjectNone, which);
if (ref.refersTo(null)) {
fail("expected " + which + " to not be cleared");
}
}

private static void expectValue(Reference<TestObject> ref,
TestObject value,
String which) throws Exception {
expectNotValue(ref, testObjectNone, which);
expectNotCleared(ref, which);
if (!ref.refersTo(value)) {
fail(which + " doesn't refer to expected value");
}
}

private static void expectNotValue(Reference<TestObject> ref,
TestObject value,
String which) throws Exception {
if (ref.refersTo(value)) {
fail(which + " refers to unexpected value");
}
}

private static void checkInitialStates() throws Exception {
expectValue(testPhantom1, testObject1, "testPhantom1");
expectValue(testWeak2, testObject2, "testWeak2");
expectValue(testWeak3, testObject3, "testWeak3");
expectValue(testWeak4, testObject4, "testWeak4");
}

private static void discardStrongReferences() {
// testObjectNone not dropped
testObject1 = null;
testObject2 = null;
// testObject3 not dropped
testObject4 = null;
}

private static boolean isShenandoahIUMode() {
return "iu".equals(WB.getStringVMFlag("ShenandoahGCMode"));
}

private static void testConcurrentCollection() throws Exception {
progress("setup concurrent collection test");
setup();
progress("gcUntilOld");
gcUntilOld();

progress("acquire control of concurrent cycles");
WB.concurrentGCAcquireControl();
try {
progress("check initial states");
checkInitialStates();

progress("discard strong references");
discardStrongReferences();

progress("run GC to before marking completed");
WB.concurrentGCRunTo(WB.BEFORE_MARKING_COMPLETED);

progress("fetch test objects, possibly keeping some alive");
expectNotCleared(testPhantom1, "testPhantom1");
expectNotCleared(testWeak2, "testWeak2");
expectValue(testWeak3, testObject3, "testWeak3");

// For some collectors, calling get() will keep testObject4 alive.
if (testWeak4.get() == null) {
fail("testWeak4 unexpectedly == null");
}

progress("finish collection");
WB.concurrentGCRunToIdle();

progress("verify expected clears");
expectCleared(testPhantom1, "testPhantom1");
expectCleared(testWeak2, "testWeak2");
expectValue(testWeak3, testObject3, "testWeak3");
// This is true for all currently supported concurrent collectors,
// except Shenandoah+IU, which allows clearing refs even when
// accessed during concurrent marking.
if (isShenandoahIUMode()) {
expectCleared(testWeak4, "testWeak4");
} else {
expectNotCleared(testWeak4, "testWeak4");
}

progress("verify get returns expected values");
if (testWeak2.get() != null) {
fail("testWeak2.get() != null");
}

TestObject obj3 = testWeak3.get();
if (obj3 == null) {
fail("testWeak3.get() returned null");
} else if (obj3.value != 3) {
fail("testWeak3.get().value is " + obj3.value);
}

TestObject obj4 = testWeak4.get();
if (!isShenandoahIUMode()) {
if (obj4 == null) {
fail("testWeak4.get() returned null");
} else if (obj4.value != 4) {
fail("testWeak4.get().value is " + obj4.value);
}
}

progress("verify queue entries");
long timeout = 60000; // 1 minute of milliseconds.
while (true) {
Reference<? extends TestObject> ref = queue.remove(timeout);
if (ref == null) {
break;
} else if (ref == testPhantom1) {
testPhantom1 = null;
} else if (ref == testWeak2) {
testWeak2 = null;
} else if (ref == testWeak3) {
testWeak3 = null;
} else if (ref == testWeak4) {
testWeak4 = null;
} else {
fail("unexpected reference in queue");
}
}
if (testPhantom1 != null) {
fail("testPhantom1 not notified");
} else if (testWeak2 != null) {
fail("testWeak2 not notified");
} else if (testWeak3 == null) {
fail("testWeak3 notified");
} else if (testWeak4 == null) {
if (obj4 != null) {
fail("testWeak4 notified");
}
}

} finally {
progress("release control of concurrent cycles");
WB.concurrentGCReleaseControl();
}
progress("finished concurrent collection test");
}

private static void testSimpleCollection() throws Exception {
progress("setup simple collection test");
setup();
progress("gcUntilOld");
gcUntilOld();

progress("check initial states");
checkInitialStates();

progress("discard strong references");
TestObject tw4 = testWeak4.get(); // Keep testObject4 alive.
discardStrongReferences();

progress("collect garbage");
WB.fullGC();

progress("verify expected clears");
expectCleared(testPhantom1, "testPhantom1");
expectCleared(testWeak2, "testWeak2");
expectValue(testWeak3, testObject3, "testWeak3");
expectNotCleared(testWeak4, "testWeak4");

progress("verify get returns expected values");
if (testWeak2.get() != null) {
fail("testWeak2.get() != null");
} else if (testWeak3.get() != testObject3) {
fail("testWeak3.get() is not expected value");
} else if (testWeak4.get() != tw4) {
fail("testWeak4.get() is not expected value");
}

progress("finished simple collection test");
}

public static void main(String[] args) throws Exception {
if (WB.supportsConcurrentGCBreakpoints()) {
testConcurrentCollection();
}
testSimpleCollection();
}
}

1 comment on commit 222a17e

@openjdk-notifier
Copy link

@openjdk-notifier openjdk-notifier bot commented on 222a17e Mar 4, 2021

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Please sign in to comment.