src/hotspot/share/classfile/placeholders.hpp

*** 39,19 ***
   public:
    // caller to create a placeholder entry must enumerate an action
    // caller claims ownership of that action
    // For parallel classloading:
    // multiple LOAD_INSTANCE threads can proceed in parallel
!   // multiple LOAD_SUPER threads can proceed in parallel
!   // LOAD_SUPER needed to check for class circularity
    // DEFINE_CLASS: ultimately define class must be single threaded
    // on a class/classloader basis
    // so the head of that queue owns the token
    // and the rest of the threads return the result the first thread gets
    enum classloadAction {
      LOAD_INSTANCE = 1,             // calling load_instance_class
!     LOAD_SUPER = 2,                // loading superclass for this class
      DEFINE_CLASS = 3               // find_or_define class
    };
    static void initialize();
    static PlaceholderEntry* get_entry(Symbol* name, ClassLoaderData* loader_data);
  
--- 39,20 ---
   public:
    // caller to create a placeholder entry must enumerate an action
    // caller claims ownership of that action
    // For parallel classloading:
    // multiple LOAD_INSTANCE threads can proceed in parallel
!   // multiple DETECT_CIRCULARITY threads can proceed in parallel
!   // DETECT_CIRCULARITY needed to check for class circularity
    // DEFINE_CLASS: ultimately define class must be single threaded
    // on a class/classloader basis
    // so the head of that queue owns the token
    // and the rest of the threads return the result the first thread gets
+   // PRIMITIVE_OBJECT_FIELD: needed to check for inline type fields circularity
    enum classloadAction {
      LOAD_INSTANCE = 1,             // calling load_instance_class
!     DETECT_CIRCULARITY = 2,        // loading while detecting class circularity
      DEFINE_CLASS = 3               // find_or_define class
    };
    static void initialize();
    static PlaceholderEntry* get_entry(Symbol* name, ClassLoaderData* loader_data);
  

*** 79,14 ***
  // on store ordering here.
  // The system dictionary is the only user of this class.
  class PlaceholderEntry {
    friend class PlaceholderTable;
   private:
!   SymbolHandle      _supername;
    JavaThread*       _definer;       // owner of define token
    InstanceKlass*    _instanceKlass; // InstanceKlass from successful define
!   SeenThread*       _superThreadQ;  // doubly-linked queue of Threads loading a superclass for this class
    SeenThread*       _loadInstanceThreadQ;  // loadInstance thread
                                      // This can't be multiple threads since class loading waits for
                                      // this token to be removed.
  
    SeenThread*       _defineThreadQ; // queue of Threads trying to define this class
--- 80,14 ---
  // on store ordering here.
  // The system dictionary is the only user of this class.
  class PlaceholderEntry {
    friend class PlaceholderTable;
   private:
!   SymbolHandle      _next_klass_name;
    JavaThread*       _definer;       // owner of define token
    InstanceKlass*    _instanceKlass; // InstanceKlass from successful define
!   SeenThread*       _circularityThreadQ;  // doubly-linked queue of Threads loading with circularity detection
    SeenThread*       _loadInstanceThreadQ;  // loadInstance thread
                                      // This can't be multiple threads since class loading waits for
                                      // this token to be removed.
  
    SeenThread*       _defineThreadQ; // queue of Threads trying to define this class

*** 97,34 ***
    SeenThread* actionToQueue(PlaceholderTable::classloadAction action);
    void set_threadQ(SeenThread* seenthread, PlaceholderTable::classloadAction action);
    void add_seen_thread(JavaThread* thread, PlaceholderTable::classloadAction action);
    bool remove_seen_thread(JavaThread* thread, PlaceholderTable::classloadAction action);
  
!   SeenThread*        superThreadQ()        const { return _superThreadQ; }
!   void               set_superThreadQ(SeenThread* SeenThread) { _superThreadQ = SeenThread; }
  
    SeenThread*        loadInstanceThreadQ() const { return _loadInstanceThreadQ; }
    void               set_loadInstanceThreadQ(SeenThread* SeenThread) { _loadInstanceThreadQ = SeenThread; }
  
    SeenThread*        defineThreadQ()       const { return _defineThreadQ; }
    void               set_defineThreadQ(SeenThread* SeenThread) { _defineThreadQ = SeenThread; }
   public:
    PlaceholderEntry() :
       _definer(nullptr), _instanceKlass(nullptr),
!      _superThreadQ(nullptr), _loadInstanceThreadQ(nullptr), _defineThreadQ(nullptr) { }
  
!   Symbol*            supername()           const { return _supername; }
!   void               set_supername(Symbol* supername);
  
    JavaThread*        definer()             const {return _definer; }
    void               set_definer(JavaThread* definer) { _definer = definer; }
  
    InstanceKlass*     instance_klass()      const {return _instanceKlass; }
    void               set_instance_klass(InstanceKlass* ik) { _instanceKlass = ik; }
  
!   bool super_load_in_progress() {
!      return (_superThreadQ != nullptr);
    }
  
    bool instance_load_in_progress() {
      return (_loadInstanceThreadQ != nullptr);
    }
--- 98,34 ---
    SeenThread* actionToQueue(PlaceholderTable::classloadAction action);
    void set_threadQ(SeenThread* seenthread, PlaceholderTable::classloadAction action);
    void add_seen_thread(JavaThread* thread, PlaceholderTable::classloadAction action);
    bool remove_seen_thread(JavaThread* thread, PlaceholderTable::classloadAction action);
  
!   SeenThread*        superThreadQ()        const { return _circularityThreadQ; }
!   void               set_superThreadQ(SeenThread* SeenThread) { _circularityThreadQ = SeenThread; }
  
    SeenThread*        loadInstanceThreadQ() const { return _loadInstanceThreadQ; }
    void               set_loadInstanceThreadQ(SeenThread* SeenThread) { _loadInstanceThreadQ = SeenThread; }
  
    SeenThread*        defineThreadQ()       const { return _defineThreadQ; }
    void               set_defineThreadQ(SeenThread* SeenThread) { _defineThreadQ = SeenThread; }
   public:
    PlaceholderEntry() :
       _definer(nullptr), _instanceKlass(nullptr),
!      _circularityThreadQ(nullptr), _loadInstanceThreadQ(nullptr), _defineThreadQ(nullptr) { }
  
!   Symbol*            next_klass_name()           const { return _next_klass_name; }
!   void               set_next_klass_name(Symbol* next_klass_name);
  
    JavaThread*        definer()             const {return _definer; }
    void               set_definer(JavaThread* definer) { _definer = definer; }
  
    InstanceKlass*     instance_klass()      const {return _instanceKlass; }
    void               set_instance_klass(InstanceKlass* ik) { _instanceKlass = ik; }
  
!   bool circularity_detection_in_progress() {
!      return (_circularityThreadQ != nullptr);
    }
  
    bool instance_load_in_progress() {
      return (_loadInstanceThreadQ != nullptr);
    }