src/jdk.jdwp.agent/share/native/libjdwp/commonRef.c

@@ -1,7 +1,7 @@
  /*
-  * Copyright (c) 1998, 2022, Oracle and/or its affiliates. All rights reserved.
+  * Copyright (c) 1998, 2026, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this

@@ -42,10 +42,12 @@
   * deleted and the weak ref inside may be reused (these may happen in
   * either order). Using the sequence number
   * as the object id prevents ambiguity in the object id when the weak ref
   * is reused. The RefNode* is stored with the object as it's JVMTI Tag.
   *
+  * References to value objects are always strong.
+  *
   * The ref member is changed from weak to strong when
   * gc of the object is to be prevented.
   * Whether or not it is strong, it is never exported from this module.
   *
   * A reference count of each jobject is also maintained here. It tracks

@@ -85,29 +87,32 @@
  /* Returns true if this is a strong reference, meaning that either or both of
     isPinAll and isCommonPin are true. */
  static jboolean
  isStrong(RefNode* node)
  {
-     return node->isPinAll || node->isCommonPin;
+     return node->isValueObject || node->isPinAll || node->isCommonPin;
  }
  
  /* Create a fresh RefNode structure, create a weak ref and tag the object */
  static RefNode *
  createNode(JNIEnv *env, jobject ref)
  {
      RefNode   *node;
      jobject    strongOrWeakRef;
      jvmtiError error;
      jboolean   pinAll = gdata->pinAllCount != 0;
+     jboolean   isValueObject;
  
      /* Could allocate RefNode's in blocks, not sure it would help much */
      node = (RefNode*)jvmtiAllocate((int)sizeof(RefNode));
      if (node == NULL) {
          return NULL;
      }
  
-     if (pinAll) {
+     isValueObject = JNI_FUNC_PTR(env,IsValueObject)(env, ref);
+ 
+     if (pinAll || isValueObject) {
          /* Create strong reference to make sure we have a reference */
          strongOrWeakRef = JNI_FUNC_PTR(env,NewGlobalRef)(env, ref);
      } else {
          /* Create weak reference to make sure we have a reference */
          strongOrWeakRef = JNI_FUNC_PTR(env,NewWeakGlobalRef)(env, ref);

@@ -134,10 +139,11 @@
      }
  
      /* Fill in RefNode */
      node->ref         = strongOrWeakRef;
      node->count       = 1;
+     node->isValueObject = isValueObject;
      node->isPinAll    = pinAll;
      node->isCommonPin = JNI_FALSE;
      node->seqNum      = newSeqNum();
  
      /* Count RefNode's created */

@@ -199,11 +205,11 @@
  
  /* Change a RefNode to have a weak reference */
  static jweak
  weakenNode(JNIEnv *env, RefNode *node, jboolean isUnpinAll)
  {
-     jboolean willStillBeStrong = (node->isPinAll && !isUnpinAll) || (node->isCommonPin && isUnpinAll);
+     jboolean willStillBeStrong = node->isValueObject || (node->isPinAll && !isUnpinAll) || (node->isCommonPin && isUnpinAll);
  
      // If the node is strong, but the reason(s) for it being strong
      // will no longer exist, then weaken it.
      if (isStrong(node) && !willStillBeStrong) {
          jweak weakRef;