jdk-24/test/hotspot/jtreg/gc/g1/pinnedobjs/TestDroppedRetainedTAMS.java

73 lines
2.8 KiB
Java

/*
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* 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
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*
* 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.
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/* @test
* @summary Check that TAMSes are correctly updated for regions dropped from
* the retained collection set candidates during a Concurrent Start pause.
* @requires vm.gc.G1
* @requires vm.flagless
* @library /test/lib
* @build jdk.test.whitebox.WhiteBox
* @run driver jdk.test.lib.helpers.ClassFileInstaller jdk.test.whitebox.WhiteBox
* @run main/othervm -XX:+UseG1GC -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions
-XX:+WhiteBoxAPI -Xbootclasspath/a:. -Xmx32m -XX:G1NumCollectionsKeepPinned=1
-XX:+VerifyBeforeGC -XX:+VerifyAfterGC -XX:G1MixedGCLiveThresholdPercent=100
-XX:G1HeapWastePercent=0 -Xlog:gc,gc+ergo+cset=trace gc.g1.pinnedobjs.TestDroppedRetainedTAMS
*/
package gc.g1.pinnedobjs;
import jdk.test.whitebox.WhiteBox;
public class TestDroppedRetainedTAMS {
private static final WhiteBox wb = WhiteBox.getWhiteBox();
private static final char[] dummy = new char[100];
public static void main(String[] args) {
wb.fullGC(); // Move the target dummy object to old gen.
wb.pinObject(dummy);
// After this concurrent cycle the pinned region will be in the the (marking)
// collection set candidates.
wb.g1RunConcurrentGC();
// Pass the Prepare mixed gc which will not do anything about the marking
// candidates.
wb.youngGC();
// Mixed GC. Will complete. That pinned region is now retained. The mixed gcs
// will end here.
wb.youngGC();
// The pinned region will be dropped from the retained candidates during the
// Concurrent Start GC, leaving that region's TAMS broken.
wb.g1RunConcurrentGC();
// Verification will find a lot of broken objects.
wb.youngGC();
System.out.println(dummy);
}
}