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
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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.
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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22 */
23
24 /**
25 * @test
26 * @bug 8312174
27 * @summary missing JVMTI events from vthreads parked during JVMTI attach
28 * @requires vm.continuations
29 * @requires vm.jvmti
30 * @requires vm.compMode != "Xcomp"
31 * @run main/othervm/native
32 * -Djdk.virtualThreadScheduler.parallelism=9
33 * -Djdk.attach.allowAttachSelf=true -XX:+EnableDynamicAgentLoading VThreadEventTest attach
34 */
35
36 import com.sun.tools.attach.VirtualMachine;
37 import java.util.concurrent.ExecutorService;
38 import java.util.concurrent.Executors;
39 import java.util.concurrent.locks.LockSupport;
40 import java.util.List;
41 import java.util.ArrayList;
42
43 /*
44 * The test uses custom implementation of the CountDownLatch class.
45 * The reason is we want the state of tested thread to be predictable.
46 * With java.util.concurrent.CountDownLatch it is not clear what thread state is expected.
47 */
48 class CountDownLatch {
49 private int count = 0;
50
51 CountDownLatch(int count) {
52 this.count = count;
53 }
54
55 public synchronized void countDown() {
56 count--;
57 notify();
58 }
59
60 public synchronized void await() throws InterruptedException {
61 while (count > 0) {
62 wait(1);
63 }
64 }
65 }
66
67 public class VThreadEventTest {
68 static final int TCNT1 = 10;
69 static final int TCNT2 = 4;
70 static final int TCNT3 = 4;
71 static final int THREAD_CNT = TCNT1 + TCNT2 + TCNT3;
72
73 private static void log(String msg) { System.out.println(msg); }
74
75 private static native int threadEndCount();
76 private static native int threadMountCount();
77 private static native int threadUnmountCount();
78
79 private static volatile boolean attached;
80 private static boolean failed;
81 private static List<Thread> test1Threads = new ArrayList(TCNT1);
82
83 private static CountDownLatch ready0 = new CountDownLatch(THREAD_CNT);
84 private static CountDownLatch ready1 = new CountDownLatch(TCNT1);
85 private static CountDownLatch ready2 = new CountDownLatch(THREAD_CNT);
86 private static CountDownLatch mready = new CountDownLatch(1);
87
88 private static void await(CountDownLatch dumpedLatch) {
89 try {
90 dumpedLatch.await();
91 } catch (InterruptedException e) {
92 throw new RuntimeException(e);
93 }
94 }
95
96 // The test1 vthreads are kept unmounted until interrupted after agent attach.
97 static final Runnable test1 = () -> {
98 synchronized (test1Threads) {
99 test1Threads.add(Thread.currentThread());
100 }
101 log("test1 vthread started");
102 ready0.countDown();
103 await(mready);
104 ready1.countDown(); // to guaranty state is not State.WAITING after await(mready)
105 try {
106 Thread.sleep(20000); // big timeout to keep unmounted until interrupted
107 } catch (InterruptedException ex) {
108 // it is expected, ignore
109 }
110 ready2.countDown();
111 };
112
113 // The test2 vthreads are kept mounted until agent attach.
114 static final Runnable test2 = () -> {
115 log("test2 vthread started");
116 ready0.countDown();
117 await(mready);
118 while (!attached) {
119 // keep mounted
120 }
121 ready2.countDown();
122 };
123
124 // The test3 vthreads are kept mounted until agent attach.
125 static final Runnable test3 = () -> {
126 log("test3 vthread started");
127 ready0.countDown();
128 await(mready);
129 while (!attached) {
130 // keep mounted
131 }
132 LockSupport.parkNanos(10_000_000L); // will cause extra mount and unmount
133 ready2.countDown();
134 };
135
136 public static void main(String[] args) throws Exception {
137 if (Runtime.getRuntime().availableProcessors() < 8) {
138 log("WARNING: test expects at least 8 processors.");
139 }
140 try (ExecutorService executorService = Executors.newVirtualThreadPerTaskExecutor()) {
141 for (int i = 0; i < TCNT1; i++) {
142 executorService.execute(test1);
143 }
144 for (int i = 0; i < TCNT2; i++) {
145 executorService.execute(test2);
146 }
147 for (int i = 0; i < TCNT3; i++) {
148 executorService.execute(test3);
149 }
150 await(ready0);
151 mready.countDown();
152 await(ready1); // to guarantee state is not State.TIMED_WAITING after await(mready) in test1()
153 // wait for test1 threads to reach TIMED_WAITING state in sleep()
154 for (Thread t : test1Threads) {
155 Thread.State state = t.getState();
156 log("DBG: state: " + state);
157 while (state != Thread.State.TIMED_WAITING) {
158 Thread.sleep(10);
159 state = t.getState();
160 log("DBG: state: " + state);
161 }
162 }
163
164 VirtualMachine vm = VirtualMachine.attach(String.valueOf(ProcessHandle.current().pid()));
165 vm.loadAgentLibrary("VThreadEventTest");
166 Thread.sleep(200); // to allow the agent to get ready
167
168 attached = true;
169 for (Thread t : test1Threads) {
170 t.interrupt();
171 }
172 ready2.await();
173 }
174 // wait until all VirtualThreadEnd events have been sent
175 for (int sleepNo = 1; threadEndCount() < THREAD_CNT; sleepNo++) {
176 Thread.sleep(100);
177 if (sleepNo % 100 == 0) { // 10 sec period of waiting
178 log("main: waited seconds: " + sleepNo/10);
179 }
180 }
181 int threadEndCnt = threadEndCount();
182 int threadMountCnt = threadMountCount();
183 int threadUnmountCnt = threadUnmountCount();
184 int threadEndExp = THREAD_CNT;
185 int threadMountExp = THREAD_CNT - TCNT2;
186 int threadUnmountExp = THREAD_CNT + TCNT3;
187
188 log("ThreadEnd cnt: " + threadEndCnt + " (expected: " + threadEndExp + ")");
189 log("ThreadMount cnt: " + threadMountCnt + " (expected: " + threadMountExp + ")");
190 log("ThreadUnmount cnt: " + threadUnmountCnt + " (expected: " + threadUnmountExp + ")");
191
192 if (threadEndCnt != threadEndExp) {
193 log("FAILED: unexpected count of ThreadEnd events");
194 failed = true;
195 }
196 if (threadMountCnt != threadMountExp) {
197 log("FAILED: unexpected count of ThreadMount events");
198 failed = true;
199 }
200 if (threadUnmountCnt != threadUnmountExp) {
201 log("FAILED: unexpected count of ThreadUnmount events");
202 failed = true;
203 }
204 if (failed) {
205 throw new RuntimeException("FAILED: event count is wrong");
206 }
207 }
208
209 }
210