1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243
|
/*
* Copyright (c) 2022, 2024, 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 id=default
* @bug 8284161 8286788
* @summary Test java.lang.management.ThreadInfo contains expected information for carrier threads
* @requires vm.continuations
* @modules java.base/java.lang:+open
* @library /test/lib
* @run junit CarrierThreadInfo
*/
/**
* @test id=LM_LIGHTWEIGHT
* @requires vm.continuations
* @modules java.base/java.lang:+open
* @library /test/lib
* @run junit/othervm -XX:LockingMode=2 CarrierThreadInfo
*/
/**
* @test id=LM_LEGACY
* @requires vm.continuations
* @modules java.base/java.lang:+open
* @library /test/lib
* @run junit/othervm -XX:LockingMode=1 CarrierThreadInfo
*/
/**
* @test id=LM_MONITOR
* @requires vm.continuations
* @modules java.base/java.lang:+open
* @library /test/lib
* @run junit/othervm -XX:LockingMode=0 CarrierThreadInfo
*/
import java.lang.management.LockInfo;
import java.lang.management.ManagementFactory;
import java.lang.management.ThreadInfo;
import java.lang.management.ThreadMXBean;
import java.util.Arrays;
import java.util.concurrent.Executor;
import java.util.concurrent.Executors;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicReference;
import jdk.test.lib.thread.VThreadScheduler;
import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;
class CarrierThreadInfo {
/**
* Test that ThreadInfo.getLockedMonitors returns information about a lock held by
* a carrier thread.
*/
@Test
void testCarrierThreadHoldsLock() throws Exception {
Object lock = new Object();
ThreadFactory factory = task -> Thread.ofPlatform().unstarted(() -> {
synchronized (lock) {
task.run();
}
});
try (var scheduler = new CustomScheduler(factory)) {
var started = new AtomicBoolean();
var done = new AtomicBoolean();
Thread vthread = scheduler.forkVirtualThread(() -> {
started.set(true);
while (!done.get()) {
Thread.onSpinWait();
}
});
try {
awaitTrue(started);
// carrier threads holds the lock
long carrierId = scheduler.carrier().threadId();
ThreadInfo threadInfo = ManagementFactory.getPlatformMXBean(ThreadMXBean.class)
.getThreadInfo(new long[] { carrierId }, true, true)[0];
boolean holdsLock = Arrays.stream(threadInfo.getLockedMonitors())
.anyMatch(mi -> mi.getIdentityHashCode() == System.identityHashCode(lock));
assertTrue(holdsLock, "Carrier should hold lock");
} finally {
done.set(true);
}
}
}
/**
* Test that ThreadInfo.getLockedMonitors does not return information about a lock
* held by mounted virtual thread.
*/
@Test
void testVirtualThreadHoldsLock() throws Exception {
ThreadFactory factory = Executors.defaultThreadFactory();
try (var scheduler = new CustomScheduler(factory)) {
var started = new AtomicBoolean();
var lock = new Object();
var done = new AtomicBoolean();
Thread vthread = scheduler.forkVirtualThread(() -> {
started.set(true);
while (!done.get()) {
Thread.onSpinWait();
}
});
try {
awaitTrue(started);
// carrier threads does not hold lock
long carrierId = scheduler.carrier().threadId();
ThreadInfo threadInfo = ManagementFactory.getPlatformMXBean(ThreadMXBean.class)
.getThreadInfo(new long[] { carrierId }, true, true)[0];
boolean holdsLock = Arrays.stream(threadInfo.getLockedMonitors())
.anyMatch(mi -> mi.getIdentityHashCode() == System.identityHashCode(lock));
assertFalse(holdsLock, "Carrier should not hold lock");
} finally {
done.set(true);
}
}
}
/**
* Test that ThreadInfo.getLockOwnerId and getLockInfo return information about a
* synthetic lock that make it appear that the carrier is blocking waiting on the
* virtual thread.
*/
@Test
void testCarrierThreadWaits() throws Exception {
ThreadFactory factory = Executors.defaultThreadFactory();
try (var scheduler = new CustomScheduler(factory)) {
var started = new AtomicBoolean();
var done = new AtomicBoolean();
Thread vthread = scheduler.forkVirtualThread(() -> {
started.set(true);
while (!done.get()) {
Thread.onSpinWait();
}
});
try {
awaitTrue(started);
long carrierId = scheduler.carrier().threadId();
long vthreadId = vthread.threadId();
ThreadInfo threadInfo = ManagementFactory.getThreadMXBean().getThreadInfo(carrierId);
assertNotNull(threadInfo);
// carrier should be blocked waiting for lock owned by virtual thread
assertEquals(vthreadId, threadInfo.getLockOwnerId());
// carrier thread should be on blocked waiting on virtual thread
LockInfo lockInfo = threadInfo.getLockInfo();
assertNotNull(lockInfo);
assertEquals(vthread.getClass().getName(), lockInfo.getClassName());
assertEquals(System.identityHashCode(vthread), lockInfo.getIdentityHashCode());
} finally {
done.set(true);
}
}
}
/**
* Custom scheduler with a single carrier thread.
*/
private static class CustomScheduler implements AutoCloseable {
private final ExecutorService pool;
private final Executor scheduler;
private final AtomicReference<Thread> carrierRef = new AtomicReference<>();
CustomScheduler(ThreadFactory factory) {
pool = Executors.newSingleThreadExecutor(factory);
scheduler = task -> {
pool.submit(() -> {
carrierRef.set(Thread.currentThread());
try {
task.run();
} finally {
carrierRef.set(null);
}
});
};
}
/**
* Returns the carrier thread if a virtual thread is mounted.
*/
Thread carrier() throws InterruptedException {
return carrierRef.get();
}
/**
* Starts a virtual thread to execute the give task.
*/
Thread forkVirtualThread(Runnable task) {
ThreadFactory factory = VThreadScheduler.virtualThreadFactory(scheduler);
Thread thread = factory.newThread(task);
thread.start();
return thread;
}
@Override
public void close() {
pool.close();
}
}
/**
* Waits for the boolean value to become true.
*/
private static void awaitTrue(AtomicBoolean ref) throws InterruptedException {
while (!ref.get()) {
Thread.sleep(20);
}
}
}
|