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/*
* Copyright (c) 2023, 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.
*
*/
/*
* @test
* @bug 8317262
* @library /testlibrary /test/lib
* @build jdk.test.whitebox.WhiteBox
* @run driver jdk.test.lib.helpers.ClassFileInstaller jdk.test.whitebox.WhiteBox
* @run main/othervm -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -XX:+HandshakeALot -XX:GuaranteedSafepointInterval=1 TestStackWalk
*/
import jvmti.JVMTIUtils;
import jdk.test.lib.Asserts;
import jdk.test.whitebox.WhiteBox;
import java.util.concurrent.CountDownLatch;
public class TestStackWalk {
static Thread worker1;
static Thread worker2;
static volatile boolean done;
static volatile int counter = 0;
static Object lock = new Object();
public static void main(String... args) throws Exception {
worker1 = new Thread(() -> syncedWorker());
worker1.start();
worker2 = new Thread(() -> syncedWorker());
worker2.start();
Thread worker3 = new Thread(() -> stackWalker());
worker3.start();
worker1.join();
worker2.join();
worker3.join();
}
public static void syncedWorker() {
synchronized (lock) {
while (!done) {
counter++;
}
}
}
public static void stackWalker() {
// Suspend workers so the one looping waiting for "done"
// doesn't execute the handshake below, increasing the
// chances the VMThread will do it.
suspendWorkers();
WhiteBox wb = WhiteBox.getWhiteBox();
long end = System.currentTimeMillis() + 20000;
while (end > System.currentTimeMillis()) {
wb.handshakeWalkStack(worker1, false /* all_threads */);
wb.handshakeWalkStack(worker2, false /* all_threads */);
}
resumeWorkers();
done = true;
}
static void suspendWorkers() {
JVMTIUtils.suspendThread(worker1);
JVMTIUtils.suspendThread(worker2);
}
static void resumeWorkers() {
JVMTIUtils.resumeThread(worker1);
JVMTIUtils.resumeThread(worker2);
}
}
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