Merge

Author: AlanBateman

src/java.management/share/classes/java/lang/management/ThreadMXBean.java

@@ -590,17 +590,13 @@ public interface ThreadMXBean extends PlatformManagedObject {
     public void setThreadCpuTimeEnabled(boolean enable);
 
     /**
-     * Finds cycles of threads that are in deadlock waiting to acquire
-     * object monitors. That is, threads that are blocked waiting to enter a
-     * synchronization block or waiting to reenter a synchronization block
-     * after an {@link Object#wait Object.wait} call,
-     * where each thread owns one monitor while
-     * trying to obtain another monitor already held by another thread
-     * in a cycle.
-     * This method returns the IDs of the platform threads that are in
-     * deadlock. The IDs of virtual threads that are in deadlock are not
-     * included. The IDs of platform threads that are in a cycle with
-     * virtual threads may or may not be included.
+     * Finds cycles of platform threads that are in deadlock waiting to acquire
+     * object monitors. That is, platform threads that are blocked waiting to
+     * enter a synchronization block or waiting to reenter a synchronization block
+     * after an {@link Object#wait Object.wait} call, where each platform thread
+     * owns one monitor while trying to obtain another monitor already held by
+     * another platform thread in a cycle. Cycles that include virtual threads
+     * are not found by this method.
      * <p>
      * More formally, a thread is <em>monitor deadlocked</em> if it is
      * part of a cycle in the relation "is waiting for an object monitor
@@ -645,14 +641,10 @@ public interface ThreadMXBean extends PlatformManagedObject {
      * Finds cycles of platform threads that are in deadlock waiting to
      * acquire object monitors or
      * <a href="LockInfo.html#OwnableSynchronizer">ownable synchronizers</a>.
-     * Threads are <em>deadlocked</em> in a cycle waiting for a lock of
-     * these two types if each thread owns one lock while
-     * trying to acquire another lock already held
-     * by another thread in the cycle.
-     * This method returns the IDs of the platform threads that are in
-     * deadlock. The IDs of virtual threads that are in deadlock are not
-     * included. The IDs of platform threads that are in a cycle with
-     * virtual threads may or may not be included.
+     * Platform threads are <em>deadlocked</em> in a cycle waiting for a lock of
+     * these two types if each thread owns one lock while trying to acquire
+     * another lock already held by another platform thread in the cycle.
+     * Cycles that include virtual threads are not found by this method.
      * <p>
      * This method is designed for troubleshooting use, but not for
      * synchronization control.  It might be an expensive operation.

src/java.management/share/classes/sun/management/ThreadImpl.java

@@ -439,12 +439,11 @@ protected void setThreadAllocatedMemoryEnabled(boolean enable) {
     /**
      * Returns an array of thread identifiers for the threads in the given
      * array. Returns {@code null} if {@code threads} is null or the array
-     * of threads only includes carrier threads.
+     * of threads is empty.
      */
     private long[] threadsToIds(Thread[] threads) {
         if (threads != null) {
             long[] tids = Stream.of(threads)
-                    .filter(t -> !(t instanceof jdk.internal.misc.CarrierThread))
                     .mapToLong(Thread::threadId)
                     .toArray();
             if (tids.length > 0) {

test/jdk/java/lang/management/ThreadMXBean/VirtualThreadDeadlocks.java

@@ -23,7 +23,8 @@
 
 /**
  * @test
- * @summary Test ThredMXBean.findDeadlockedThreads with deadlocked virtual threads
+ * @summary Test ThredMXBean.findMonitorDeadlockedThreads with cycles of
+ *   platform and virtual threads in deadlock
  * @compile --enable-preview -source ${jdk.version} VirtualThreadDeadlocks.java
  * @run main/othervm --enable-preview VirtualThreadDeadlocks PP
  * @run main/othervm --enable-preview VirtualThreadDeadlocks PV
@@ -74,8 +75,8 @@ public static void main(String[] args) throws Exception {
         Thread.sleep(2000);
 
         ThreadMXBean bean = ManagementFactory.getPlatformMXBean(ThreadMXBean.class);
-        long[] deadlockedThreads = sorted(bean.findDeadlockedThreads());
-        System.out.println("findDeadlockedThreads => " + Arrays.toString(deadlockedThreads));
+        long[] deadlockedThreads = sorted(bean.findMonitorDeadlockedThreads());
+        System.out.println("findMonitorDeadlockedThreads => " + Arrays.toString(deadlockedThreads));
 
         // deadlocks involving virtual threads are not detected
         long[] expectedThreads = (!thread1.isVirtual() && !thread2.isVirtual())