1 /*
  2  * Copyright (c) 2023, Oracle and/or its affiliates. All rights reserved.
  3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  4  *
  5  * This code is free software; you can redistribute it and/or modify it
  6  * under the terms of the GNU General Public License version 2 only, as
  7  * published by the Free Software Foundation.
  8  *
  9  * This code is distributed in the hope that it will be useful, but WITHOUT
 10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 12  * version 2 for more details (a copy is included in the LICENSE file that
 13  * accompanied this code).
 14  *
 15  * You should have received a copy of the GNU General Public License version
 16  * 2 along with this work; if not, write to the Free Software Foundation,
 17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 18  *
 19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 20  * or visit www.oracle.com if you need additional information or have any
 21  * questions.
 22  */
 23 
 24 /**
 25  * @test
 26  * @bug 8307365
 27  * @summary Exercise JvmtiThreadState creation concurrently with terminating vthreads
 28  * @requires vm.continuations
 29  * @modules java.base/java.lang:+open
 30  * @run main/othervm/native -agentlib:ThreadStateTest ThreadStateTest
 31  */
 32 
 33 import java.util.concurrent.*;
 34 import java.util.Arrays;
 35 import java.util.ArrayList;
 36 import java.util.List;
 37 import java.lang.reflect.Constructor;
 38 import java.lang.reflect.InvocationTargetException;
 39 
 40 public class ThreadStateTest {
 41     static final int VTHREAD_COUNT = 64;
 42 
 43     private static native void setSingleSteppingMode(boolean enable);
 44     private static native void setMonitorContendedMode(boolean enable);
 45     private static native void testGetThreadState(Thread thread);
 46     private static native void testGetThreadListStackTraces(Thread thread);
 47 
 48     final Runnable FOO = () -> {
 49         testGetThreadState(Thread.currentThread());
 50         testGetThreadListStackTraces(Thread.currentThread());
 51         Thread.yield();
 52     };
 53 
 54     private void runTest() throws Exception {
 55         int tryCount = 150;
 56 
 57         // Force creation of JvmtiThreadState on vthread start.
 58         setMonitorContendedMode(true);
 59 
 60         while (tryCount-- > 0) {
 61             ExecutorService scheduler = Executors.newFixedThreadPool(8);
 62             ThreadFactory factory = virtualThreadBuilder(scheduler).factory();
 63 
 64             List<Thread> virtualThreads = new ArrayList<>();
 65             for (int i = 0; i < VTHREAD_COUNT; i++) {
 66                 Thread vt = factory.newThread(FOO);
 67                 vt.setName("VT-" + i);
 68                 virtualThreads.add(vt);
 69             }
 70 
 71             for (Thread t : virtualThreads) {
 72                 t.start();
 73             }
 74 
 75             // Give some time for vthreads to finish.
 76             Thread.sleep(10);
 77 
 78             // Trigger race of JvmtiThreadState creation with terminating vthreads.
 79             setMonitorContendedMode(false);
 80             setMonitorContendedMode(true);
 81 
 82             for (Thread t : virtualThreads) {
 83                 t.join();
 84             }
 85             // Let all carriers go away.
 86             scheduler.shutdown();
 87             Thread.sleep(20);
 88 
 89             // Check that looping over all JvmtiThreadStates works fine.
 90             setSingleSteppingMode(true);
 91 
 92             // Reset for next iteration
 93             setSingleSteppingMode(false);
 94         }
 95     }
 96 
 97     public static void main(String[] args) throws Exception {
 98         ThreadStateTest obj = new ThreadStateTest();
 99         obj.runTest();
100     }
101 
102     private static Thread.Builder.OfVirtual virtualThreadBuilder(Executor scheduler) {
103         Thread.Builder.OfVirtual builder = Thread.ofVirtual();
104         try {
105             Class<?> clazz = Class.forName("java.lang.ThreadBuilders$VirtualThreadBuilder");
106             Constructor<?> ctor = clazz.getDeclaredConstructor(Executor.class);
107             ctor.setAccessible(true);
108             return (Thread.Builder.OfVirtual) ctor.newInstance(scheduler);
109         } catch (InvocationTargetException e) {
110             Throwable cause = e.getCause();
111             if (cause instanceof RuntimeException re) {
112                 throw re;
113             }
114             throw new RuntimeException(e);
115         } catch (Exception e) {
116             throw new RuntimeException(e);
117         }
118     }
119 }