Merge pull request #43594 from panic08

* pr/43594:
  Polish "Add info contributor support for JDK 24's VirtualThreadSchedulerMXBean"
  Add info contributor support for JDK 24's VirtualThreadSchedulerMXBean

Closes gh-43594

Author: mhalbritter

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/info/ProcessInfo.java

@@ -19,11 +19,13 @@
 import java.lang.management.ManagementFactory;
 import java.lang.management.MemoryMXBean;
 import java.lang.management.MemoryUsage;
+import java.lang.management.PlatformManagedObject;
 
 /**
  * Information about the process of the application.
  *
  * @author Jonatan Ivanov
+ * @author Andrey Litvitski
  * @since 3.3.0
  */
 public class ProcessInfo {
@@ -72,6 +74,31 @@ public MemoryInfo getMemory() {
 		return new MemoryInfo();
 	}
 
+	/**
+	 * Virtual threads information for the process. These values provide details about the
+	 * current state of virtual threads, including the number of mounted threads, queued
+	 * threads, the parallelism level, and the thread pool size.
+	 * @return an instance of {@link VirtualThreadsInfo} containing information about
+	 * virtual threads, or {@code null} if the VirtualThreadSchedulerMXBean is not
+	 * available.
+	 * @since 3.5.0
+	 */
+	@SuppressWarnings("unchecked")
+	public VirtualThreadsInfo getVirtualThreads() {
+		try {
+			Class<PlatformManagedObject> mxBeanClass = (Class<PlatformManagedObject>) Class
+				.forName("jdk.management.VirtualThreadSchedulerMXBean");
+			Object bean = ManagementFactory.getPlatformMXBean(mxBeanClass);
+			return new VirtualThreadsInfo((Integer) mxBeanClass.getMethod("getMountedVirtualThreadCount").invoke(bean),
+					(Long) mxBeanClass.getMethod("getQueuedVirtualThreadCount").invoke(bean),
+					(Integer) mxBeanClass.getMethod("getParallelism").invoke(bean),
+					(Integer) mxBeanClass.getMethod("getPoolSize").invoke(bean));
+		}
+		catch (ReflectiveOperationException ex) {
+			return null;
+		}
+	}
+
 	public long getPid() {
 		return this.pid;
 	}
@@ -84,6 +111,46 @@ public String getOwner() {
 		return this.owner;
 	}
 
+	/**
+	 * Virtual threads information.
+	 *
+	 * @since 3.5.0
+	 */
+	public static class VirtualThreadsInfo {
+
+		private final int mounted;
+
+		private final long queued;
+
+		private final int parallelism;
+
+		private final int poolSize;
+
+		public VirtualThreadsInfo(int mounted, long queued, int parallelism, int poolSize) {
+			this.mounted = mounted;
+			this.queued = queued;
+			this.parallelism = parallelism;
+			this.poolSize = poolSize;
+		}
+
+		public long getMounted() {
+			return this.mounted;
+		}
+
+		public long getQueued() {
+			return this.queued;
+		}
+
+		public int getParallelism() {
+			return this.parallelism;
+		}
+
+		public int getPoolSize() {
+			return this.poolSize;
+		}
+
+	}
+
 	/**
 	 * Memory information.
 	 *

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/info/ProcessInfoTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2024 the original author or authors.
+ * Copyright 2012-2025 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,15 +17,19 @@
 package org.springframework.boot.info;
 
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.condition.EnabledForJreRange;
+import org.junit.jupiter.api.condition.JRE;
 
 import org.springframework.boot.info.ProcessInfo.MemoryInfo.MemoryUsageInfo;
+import org.springframework.boot.info.ProcessInfo.VirtualThreadsInfo;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
 /**
  * Tests for {@link ProcessInfo}.
  *
  * @author Jonatan Ivanov
+ * @author Andrey Litvitski
  */
 class ProcessInfoTests {
 
@@ -54,4 +58,23 @@ void memoryInfoIsAvailable() {
 		assertThat(nonHeapUsageInfo.getMax()).isEqualTo(-1);
 	}
 
+	@Test
+	@EnabledForJreRange(min = JRE.JAVA_24)
+	void virtualThreadsInfoIfAvailable() {
+		ProcessInfo processInfo = new ProcessInfo();
+		VirtualThreadsInfo virtualThreadsInfo = processInfo.getVirtualThreads();
+		assertThat(virtualThreadsInfo).isNotNull();
+		assertThat(virtualThreadsInfo.getMounted()).isGreaterThanOrEqualTo(0);
+		assertThat(virtualThreadsInfo.getQueued()).isGreaterThanOrEqualTo(0);
+		assertThat(virtualThreadsInfo.getParallelism()).isGreaterThan(0);
+		assertThat(virtualThreadsInfo.getPoolSize()).isGreaterThanOrEqualTo(0);
+	}
+
+	@Test
+	@EnabledForJreRange(max = JRE.JAVA_23)
+	void virtualThreadsInfoIfNotAvailable() {
+		ProcessInfo processInfo = new ProcessInfo();
+		assertThat(processInfo.getVirtualThreads()).isNull();
+	}
+
 }