8322818: Thread::getStackTrace can fail with InternalError if virtual thread is timed-parked when pinned

Reviewed-by: pchilanomate
This commit is contained in:
Alan Bateman 2024-01-04 05:59:52 +00:00
parent 755722ced6
commit 4db7a1c3bb
2 changed files with 78 additions and 3 deletions
src/java.base/share/classes/java/lang
test/jdk/java/lang/Thread/virtual/stress

@ -975,12 +975,12 @@ final class VirtualThread extends BaseVirtualThread {
* Returns null if the thread is mounted or in transition.
*/
private StackTraceElement[] tryGetStackTrace() {
int initialState = state();
int initialState = state() & ~SUSPENDED;
switch (initialState) {
case NEW, STARTED, TERMINATED -> {
return new StackTraceElement[0]; // unmounted, empty stack
}
case RUNNING, PINNED -> {
case RUNNING, PINNED, TIMED_PINNED -> {
return null; // mounted
}
case PARKED, TIMED_PARKED -> {
@ -992,7 +992,7 @@ final class VirtualThread extends BaseVirtualThread {
case PARKING, TIMED_PARKING, YIELDING -> {
return null; // in transition
}
default -> throw new InternalError();
default -> throw new InternalError("" + initialState);
}
// thread is unmounted, prevent it from continuing

@ -0,0 +1,75 @@
/*
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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
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*
* This code is distributed in the hope that it will be useful, but WITHOUT
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* 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 8322818
* @summary Stress test Thread.getStackTrace on a virtual thread that is pinned
* @requires vm.debug != true
* @run main GetStackTraceALotWhenPinned 100000
*/
/*
* @test
* @requires vm.debug == true
* @run main/timeout=300 GetStackTraceALotWhenPinned 10000
*/
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.locks.LockSupport;
public class GetStackTraceALotWhenPinned {
public static void main(String[] args) throws Exception {
var counter = new AtomicInteger(Integer.parseInt(args[0]));
// Start a virtual thread that loops doing Thread.yield and parking while pinned.
// This loop creates the conditions for the main thread to sample the stack trace
// as it transitions from being unmounted to parking while pinned.
var thread = Thread.startVirtualThread(() -> {
boolean timed = false;
while (counter.decrementAndGet() > 0) {
Thread.yield();
synchronized (GetStackTraceALotWhenPinned.class) {
if (timed) {
LockSupport.parkNanos(Long.MAX_VALUE);
} else {
LockSupport.park();
}
}
timed = !timed;
}
});
long lastTimestamp = System.currentTimeMillis();
while (thread.isAlive()) {
thread.getStackTrace();
LockSupport.unpark(thread);
long currentTime = System.currentTimeMillis();
if ((currentTime - lastTimestamp) > 500) {
System.out.println(counter.get() + " remaining ...");
lastTimestamp = currentTime;
}
}
}
}