8359870: JVM crashes in AccessInternal::PostRuntimeDispatch

Reviewed-by: alanb, sspitsyn
Backport-of: 13a3927855da61fe27f3b43e5e4755d0c5ac5a16

src/hotspot/share/prims/jvm.cpp

@@ -2966,7 +2966,7 @@ JVM_ENTRY(jobject, JVM_CreateThreadSnapshot(JNIEnv* env, jobject jthread))
   oop snapshot = ThreadSnapshotFactory::get_thread_snapshot(jthread, THREAD);
   return JNIHandles::make_local(THREAD, snapshot);
 #else
-  return nullptr;
+  THROW_NULL(vmSymbols::java_lang_UnsupportedOperationException());
 #endif
 JVM_END
 

src/hotspot/share/services/threadService.cpp

@@ -1439,7 +1439,17 @@ oop ThreadSnapshotFactory::get_thread_snapshot(jobject jthread, TRAPS) {
 
   ResourceMark rm(THREAD);
   HandleMark   hm(THREAD);
-  Handle thread_h(THREAD, JNIHandles::resolve(jthread));
+
+  JavaThread* java_thread = nullptr;
+  oop thread_oop;
+  bool has_javathread = tlh.cv_internal_thread_to_JavaThread(jthread, &java_thread, &thread_oop);
+  assert((has_javathread && thread_oop != nullptr) || !has_javathread, "Missing Thread oop");
+  Handle thread_h(THREAD, thread_oop);
+  bool is_virtual = java_lang_VirtualThread::is_instance(thread_h());  // Deals with null
+
+  if (!has_javathread && !is_virtual) {
+    return nullptr; // thread terminated so not of interest
+  }
 
   // wrapper to auto delete JvmtiVTMSTransitionDisabler
   class TransitionDisabler {
@@ -1460,8 +1470,6 @@ oop ThreadSnapshotFactory::get_thread_snapshot(jobject jthread, TRAPS) {
     }
   } transition_disabler;
 
-  JavaThread* java_thread = nullptr;
-  bool is_virtual = java_lang_VirtualThread::is_instance(thread_h());
   Handle carrier_thread;
   if (is_virtual) {
     // 1st need to disable mount/unmount transitions

src/java.base/share/classes/jdk/internal/vm/ThreadDumper.java

@@ -177,8 +177,11 @@ public class ThreadDumper {
         container.children().forEach(c -> dumpThreads(c, writer));
     }
 
-    private static void dumpThread(Thread thread, TextWriter writer) {
+    private static boolean dumpThread(Thread thread, TextWriter writer) {
         ThreadSnapshot snapshot = ThreadSnapshot.of(thread);
+        if (snapshot == null) {
+            return false; // thread terminated
+        }
         Instant now = Instant.now();
         Thread.State state = snapshot.threadState();
         writer.println("#" + thread.threadId() + " \"" + snapshot.threadName()
@@ -217,6 +220,7 @@ public class ThreadDumper {
             depth++;
         }
         writer.println();
+        return true;
     }
 
     /**
@@ -284,8 +288,9 @@ public class ThreadDumper {
         Iterator<Thread> threads = container.threads().iterator();
         while (threads.hasNext()) {
             Thread thread = threads.next();
-            dumpThread(thread, jsonWriter);
-            threadCount++;
+            if (dumpThread(thread, jsonWriter)) {
+                threadCount++;
+            }
         }
         jsonWriter.endArray(); // threads
 
@@ -303,11 +308,15 @@ public class ThreadDumper {
 
     /**
      * Write a thread to the given JSON writer.
+     * @return true if the thread dump was written, false otherwise
      * @throws UncheckedIOException if an I/O error occurs
      */
-    private static void dumpThread(Thread thread, JsonWriter jsonWriter) {
+    private static boolean dumpThread(Thread thread, JsonWriter jsonWriter) {
         Instant now = Instant.now();
         ThreadSnapshot snapshot = ThreadSnapshot.of(thread);
+        if (snapshot == null) {
+            return false; // thread terminated
+        }
         Thread.State state = snapshot.threadState();
         StackTraceElement[] stackTrace = snapshot.stackTrace();
 
@@ -369,6 +378,7 @@ public class ThreadDumper {
         }
 
         jsonWriter.endObject();
+        return true;
     }
 
     /**

src/java.base/share/classes/jdk/internal/vm/ThreadSnapshot.java

@@ -52,12 +52,14 @@ class ThreadSnapshot {
 
     /**
      * Take a snapshot of a Thread to get all information about the thread.
+     * Return null if a ThreadSnapshot is not created, for example if the
+     * thread has terminated.
      * @throws UnsupportedOperationException if not supported by VM
      */
     static ThreadSnapshot of(Thread thread) {
         ThreadSnapshot snapshot = create(thread);
         if (snapshot == null) {
-            throw new UnsupportedOperationException();
+            return null; // thread terminated
         }
         if (snapshot.stackTrace == null) {
             snapshot.stackTrace = EMPTY_STACK;

test/jdk/com/sun/management/HotSpotDiagnosticMXBean/DumpThreadsWithEliminatedLock.java

@@ -168,4 +168,4 @@ public class DumpThreadsWithEliminatedLock {
         Files.delete(file);
         return file;
     }
-}
+}