src/hotspot/share/classfile/classLoaderData.hpp

CLD claiming

   s2 _keep_alive;          // if this CLD is kept alive.
                            // Used for unsafe anonymous classes and the boot class
                            // loader. _keep_alive does not need to be volatile or
                            // atomic since there is one unique CLD per unsafe anonymous class.
 
-  volatile int _claimed;   // true if claimed, for example during GC traces.
-                           // To avoid applying oop closure more than once.
-                           // Has to be an int because we cas it.
+  volatile int _claim_value; // non-zero if claimed, for example during GC traces.
+                             // To avoid applying oop closure more than once.
   ChunkedHandleList _handles; // Handles to constant pool arrays, Modules, etc, which
                               // have the same life cycle of the corresponding ClassLoader.
 
   NOT_PRODUCT(volatile int _dependency_count;)  // number of class loader dependencies
 

@@ -329,15 +328,27
   MetaWord* allocate(size_t size);
 
   Dictionary* create_dictionary();
 
   void initialize_name(Handle class_loader);
+
  public:
   // GC interface.
-  void clear_claimed() { _claimed = 0; }
-  bool claimed() const { return _claimed == 1; }
-  bool claim();
+
+  // The "claim_value" is typically used to check if oops_do needs to be applied on
+  // the CLD or not. Most GCs only perform strong marking during the marking phase,
+  // in which case the claim value is
+  enum {
+    _claim_value_none        = 0,
+    _claim_value_strong      = 1,
+    _claim_value_finalizable = 2
+  };
+  void clear_claimed() { _claim_value = 0; }
+  bool claimed() const { return _claim_value != 0; }
+  bool claim(int claim_value);
+  int claim_value() const { return _claim_value; }
+  void set_claim_value(int claim_value) { _claim_value = claim_value; }
 
   // Computes if the CLD is alive or not. This is safe to call in concurrent
   // contexts.
   bool is_alive() const;
 

@@ -393,11 +404,11
   void inc_keep_alive();
   void dec_keep_alive();
 
   void initialize_holder(Handle holder);
 
-  void oops_do(OopClosure* f, bool must_claim, bool clear_modified_oops = false);
+  void oops_do(OopClosure* f, int claim_value, bool clear_modified_oops = false);
 
   void classes_do(KlassClosure* klass_closure);
   Klass* klasses() { return _klasses; }
 
   JNIMethodBlock* jmethod_ids() const              { return _jmethod_ids; }