Memory leak in JVM_StartThread with the integration of Virtual threads

Issue	Fix Version	Assignee	Priority	Status	Resolution	Resolved In Build
JDK-8297690	19.0.2	David Holmes	P4	Resolved	Fixed	b07

ADDITIONAL SYSTEM INFORMATION :
Microsoft Windows [Version 10.0.19044.2006]

openjdk version "19.0.1" 2022-10-18
OpenJDK Runtime Environment (build 19.0.1+10-21)
OpenJDK 64-Bit Server VM (build 19.0.1+10-21, mixed mode, sharing)

A DESCRIPTION OF THE PROBLEM :
See https://youtrack.jetbrains.com/issue/IDEA-305072 for a related discussion.

The attached testcase runs fine without a debugger, but if you run it in debug mode the JVM will get progressively slower until ~2 hours later the JVM will hang indefinitely.

Sometimes the hang is so bad that jstack and jmap will refuse to connect (they are probably unable to spawn a new thread).

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
1. Start a debugging session of the attached testcase:
2. About 2 hours - 2:30 hours later, output will cease and the JVM will hang indefinitely.
3. If you run the same testcase without a debugging session, it will not hang.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
There are about 500 live threads running at a time and no threads or memory seem to be leaking (as far as VisualVM seems to show), so I am not expecting a hang or a crash.
ACTUAL -
JVM hangs. Often when this happens, jstack (and related tools) cannot attach to probe the state of the JVM.

---------- BEGIN SOURCE ----------
pom.xml:
----------------------------
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>

<groupId>org.example</groupId>
<artifactId>ThreadsHang</artifactId>
<version>1.0-SNAPSHOT</version>

<properties>
<maven.compiler.release>19</maven.compiler.release>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>

<dependencies>
<dependency>
<groupId>com.google.guava</groupId>
<artifactId>guava</artifactId>
<version>31.1-jre</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>2.0.3</version>
</dependency>
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-classic</artifactId>
<version>1.4.4</version>
<exclusions>
<exclusion>
<groupId>javax.activation</groupId>
<artifactId>activation</artifactId>
</exclusion>
<exclusion>
<groupId>com.sun.mail</groupId>
<artifactId>javax.mail</artifactId>
</exclusion>
</exclusions>
</dependency>
</dependencies>

<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.10.1</version>
<configuration>
<showWarnings>true</showWarnings>
<showDeprecation>true</showDeprecation>
<compilerArgs>
<arg>-Xlint:all,-preview,-try</arg>
<arg>-Xdiags:verbose</arg>
<arg>-Werror</arg>
<arg>--enable-preview</arg>
</compilerArgs>
</configuration>
</plugin>
</plugins>
</build>
</project>

PlatformThreadsTestcase:
---------------------------------------
import com.google.common.util.concurrent.ThreadFactoryBuilder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Semaphore;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.atomic.LongAdder;

public class PlatformThreadsTestcase
{
private final ThreadFactory blockingTasksThreadFactory = new ThreadFactoryBuilder().
setNameFormat("BlockingTask-%d").
build();
private final ExecutorService blockingTasksExecutor = Executors.newThreadPerTaskExecutor(
blockingTasksThreadFactory);
private final Logger log = LoggerFactory.getLogger(PlatformThreadsTestcase.class);

public static void main(String[] args) throws InterruptedException
{
PlatformThreadsTestcase testcase = new PlatformThreadsTestcase();
testcase.run();
}

public void run() throws InterruptedException
{
Semaphore semaphore = new Semaphore(500);
LongAdder adder = new LongAdder();
while (true)
{
semaphore.acquire();
blockingTasksExecutor.submit(() ->
{
adder.increment();
long sum = adder.sum();
if ((sum % 1000) == 0)
log.info("Progress: {}", sum);
try
{
Thread.sleep(50);
}
catch (InterruptedException e)
{
throw new RuntimeException(e);
}
finally
{
semaphore.release();
}
});
}
}
}
---------- END SOURCE ----------

FREQUENCY : always