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src/hotspot/share/classfile/classLoaderData.hpp

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@@ -24,21 +24,15 @@
 
 #ifndef SHARE_VM_CLASSFILE_CLASSLOADERDATA_HPP
 #define SHARE_VM_CLASSFILE_CLASSLOADERDATA_HPP
 
 #include "memory/allocation.hpp"
-#include "memory/memRegion.hpp"
-#include "memory/metaspace.hpp"
-#include "memory/metaspaceCounters.hpp"
 #include "oops/oopHandle.hpp"
-#include "runtime/mutex.hpp"
+#include "runtime/handles.hpp"
 #include "trace/traceMacros.hpp"
 #include "utilities/growableArray.hpp"
 #include "utilities/macros.hpp"
-#if INCLUDE_TRACE
-#include "utilities/ticks.hpp"
-#endif
 
 //
 // A class loader represents a linkset. Conceptually, a linkset identifies
 // the complete transitive closure of resolved links that a dynamic linker can
 // produce.

@@ -49,26 +43,26 @@
 //
 // ClassLoaderData are stored in the runtime representation of classes,
 // and provides iterators for root tracing and other GC operations.
 
 class ClassLoaderData;
+class Dictionary;
 class JNIMethodBlock;
-class Metadebug;
+class Metaspace;
 class ModuleEntry;
-class PackageEntry;
 class ModuleEntryTable;
+class Mutex;
+class PackageEntry;
 class PackageEntryTable;
-class DictionaryEntry;
-class Dictionary;
 
 // GC root for walking class loader data created
 
 class ClassLoaderDataGraph : public AllStatic {
   friend class ClassLoaderData;
-  friend class ClassLoaderDataGraphMetaspaceIterator;
   friend class ClassLoaderDataGraphKlassIteratorAtomic;
   friend class ClassLoaderDataGraphKlassIteratorStatic;
+  friend class ClassLoaderDataGraphMetaspaceIterator;
   friend class VMStructs;
  private:
   // All CLDs (except the null CLD) can be reached by walking _head->_next->...
   static ClassLoaderData* _head;
   static ClassLoaderData* _unloading;

@@ -79,11 +73,10 @@
   // OOM has been seen in metaspace allocation. Used to prevent some
   // allocations until class unloading
   static bool _metaspace_oom;
 
   static ClassLoaderData* add(Handle class_loader, bool anonymous, TRAPS);
-  static void post_class_unload_events();
  public:
   static ClassLoaderData* find_or_create(Handle class_loader, TRAPS);
   static void purge();
   static void clear_claimed_marks();
   // oops do

@@ -147,108 +140,77 @@
 
   static bool has_metaspace_oom()           { return _metaspace_oom; }
   static void set_metaspace_oom(bool value) { _metaspace_oom = value; }
 
   static void dump_on(outputStream * const out) PRODUCT_RETURN;
-  static void dump() { dump_on(tty); }
-  static void verify();
-  static void print_creation(outputStream* out, Handle loader, ClassLoaderData* cld, TRAPS);
-
   static bool unload_list_contains(const void* x);
-#ifndef PRODUCT
-  static bool contains_loader_data(ClassLoaderData* loader_data);
-#endif
 
-#if INCLUDE_TRACE
- private:
-  static Ticks _class_unload_time;
-  static void class_unload_event(Klass* const k);
-#endif
+  NOT_PRODUCT(static void verify();)
+  NOT_PRODUCT(static bool contains_loader_data(ClassLoaderData* loader_data);)
 };
 
 // ClassLoaderData class
 
 class ClassLoaderData : public CHeapObj<mtClass> {
+  friend class ClassLoaderDataGraph;
+  friend class ClassLoaderDataGraphKlassIteratorAtomic;
+  friend class ClassLoaderDataGraphKlassIteratorStatic;
+  friend class ClassLoaderDataGraphMetaspaceIterator;
+  friend class MetaDataFactory;
+  friend class Method;
+  friend class Universe;
   friend class VMStructs;
  private:
   class Dependencies VALUE_OBJ_CLASS_SPEC {
+    friend class ClassLoaderData;
+    friend class ClassLoaderDataGraph;
+   private:
     objArrayOop _list_head;
-    void locked_add(objArrayHandle last,
-                    objArrayHandle new_dependency,
-                    Thread* THREAD);
-   public:
     Dependencies() : _list_head(NULL) {}
-    Dependencies(TRAPS) : _list_head(NULL) {
-      init(CHECK);
-    }
-    void add(Handle dependency, TRAPS);
+    Dependencies(TRAPS) : _list_head(NULL) { init(CHECK); }
     void init(TRAPS);
+    void add(Handle dependency, TRAPS);
+    void locked_add(objArrayHandle last, objArrayHandle new_dependency, Thread* THREAD);
     void oops_do(OopClosure* f);
   };
 
   class ChunkedHandleList VALUE_OBJ_CLASS_SPEC {
+    friend class ClassLoaderData;
+   private:
     struct Chunk : public CHeapObj<mtClass> {
       static const size_t CAPACITY = 32;
-
       oop _data[CAPACITY];
       volatile juint _size;
       Chunk* _next;
-
-      Chunk(Chunk* c) : _next(c), _size(0) { }
+      Chunk(Chunk* c) : _next(c), _size(0) {}
     };
-
     Chunk* volatile _head;
-
-    void oops_do_chunk(OopClosure* f, Chunk* c, const juint size);
-
-   public:
     ChunkedHandleList() : _head(NULL) {}
     ~ChunkedHandleList();
 
     // Only one thread at a time can add, guarded by ClassLoaderData::metaspace_lock().
     // However, multiple threads can execute oops_do concurrently with add.
     oop* add(oop o);
-#ifdef ASSERT
-    bool contains(oop* p);
-#endif
     void oops_do(OopClosure* f);
+    void oops_do_chunk(OopClosure* f, Chunk* c, const juint size);
+    DEBUG_ONLY(bool contains(oop* p);)
   };
 
-  friend class ClassLoaderDataGraph;
-  friend class ClassLoaderDataGraphKlassIteratorAtomic;
-  friend class ClassLoaderDataGraphKlassIteratorStatic;
-  friend class ClassLoaderDataGraphMetaspaceIterator;
-  friend class MetaDataFactory;
-  friend class Method;
+  static ClassLoaderData* _the_null_class_loader_data;
 
-  static ClassLoaderData * _the_null_class_loader_data;
+  Dependencies _dependencies; // holds dependencies from this class loader
+                              // data to others.
+
+  ChunkedHandleList _handles; // Handles to constant pool arrays, Modules, etc, which
+                              // have the same life cycle of the corresponding ClassLoader.
 
   oop _class_loader;          // oop used to uniquely identify a class loader
                               // class loader or a canonical class path
-  Dependencies _dependencies; // holds dependencies from this class loader
-                              // data to others.
 
   Metaspace * volatile _metaspace;  // Meta-space where meta-data defined by the
                                     // classes in the class loader are allocated.
   Mutex* _metaspace_lock;  // Locks the metaspace for allocations and setup.
-  bool _unloading;         // true if this class loader goes away
-  bool _is_anonymous;      // if this CLD is for an anonymous class
-
-  // Remembered sets support for the oops in the class loader data.
-  bool _modified_oops;             // Card Table Equivalent (YC/CMS support)
-  bool _accumulated_modified_oops; // Mod Union Equivalent (CMS support)
-
-  s2 _keep_alive;          // if this CLD is kept alive without a keep_alive_object().
-                           // Used for anonymous classes and the boot class
-                           // loader. _keep_alive does not need to be volatile or
-                           // atomic since there is one unique CLD per 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.
-  ChunkedHandleList _handles; // Handles to constant pool arrays, Modules, etc, which
-                              // have the same life cycle of the corresponding ClassLoader.
 
   Klass* volatile _klasses;              // The classes defined by the class loader.
   PackageEntryTable* volatile _packages; // The packages defined by the class loader.
   ModuleEntryTable*  volatile _modules;  // The modules defined by the class loader.
   ModuleEntry* _unnamed_module;          // This class loader's unnamed module.

@@ -264,169 +226,151 @@
   GrowableArray<Metadata*>*      _deallocate_list;
 
   // Support for walking class loader data objects
   ClassLoaderData* _next; /// Next loader_datas created
 
-  // ReadOnly and ReadWrite metaspaces (static because only on the null
-  // class loader for now).
-  static Metaspace* _ro_metaspace;
-  static Metaspace* _rw_metaspace;
+  s2 _keep_alive;          // if this CLD is kept alive without a keep_alive_object().
+                           // Used for anonymous classes and the boot class
+                           // loader. _keep_alive does not need to be volatile or
+                           // atomic since there is one unique CLD per 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.
 
   TRACE_DEFINE_TRACE_ID_FIELD;
 
+  bool _unloading;         // true if this class loader goes away
+  bool _is_anonymous;      // if this CLD is for an anonymous class
+
+  // Remembered sets support for the oops in the class loader data.
+  bool _modified_oops;             // Card Table Equivalent (YC/CMS support)
+  bool _accumulated_modified_oops; // Mod Union Equivalent (CMS support)
+
   void set_next(ClassLoaderData* next) { _next = next; }
   ClassLoaderData* next() const        { return _next; }
 
   ClassLoaderData(Handle h_class_loader, bool is_anonymous, Dependencies dependencies);
   ~ClassLoaderData();
 
-  // GC interface.
-  void clear_claimed()          { _claimed = 0; }
-  bool claimed() const          { return _claimed == 1; }
-  bool claim();
+  void init_dependencies(TRAPS);
+
+  // Deallocate free list during class unloading.
+  void free_deallocate_list();
+  void unload_deallocate_list();    // for the classes that are unloaded
+
+  void unload();
+  bool keep_alive() const { return _keep_alive > 0; }
 
   // The CLD are not placed in the Heap, so the Card Table or
   // the Mod Union Table can't be used to mark when CLD have modified oops.
   // The CT and MUT bits saves this information for the whole class loader data.
   void clear_modified_oops()             { _modified_oops = false; }
- public:
-  void record_modified_oops()            { _modified_oops = true; }
-  bool has_modified_oops()               { return _modified_oops; }
-
-  void accumulate_modified_oops()        { if (has_modified_oops()) _accumulated_modified_oops = true; }
-  void clear_accumulated_modified_oops() { _accumulated_modified_oops = false; }
-  bool has_accumulated_modified_oops()   { return _accumulated_modified_oops; }
- private:
 
-  void unload();
-  bool keep_alive() const       { return _keep_alive > 0; }
   void classes_do(void f(Klass*));
-  void loaded_classes_do(KlassClosure* klass_closure);
   void classes_do(void f(InstanceKlass*));
+  void loaded_classes_do(KlassClosure* klass_closure);
   void methods_do(void f(Method*));
   void modules_do(void f(ModuleEntry*));
   void packages_do(void f(PackageEntry*));
 
-  // Deallocate free list during class unloading.
-  void free_deallocate_list();      // for the classes that are not unloaded
-  void unload_deallocate_list();    // for the classes that are unloaded
-
-  // Allocate out of this class loader data
-  MetaWord* allocate(size_t size);
-
-  Dictionary* create_dictionary();
  public:
+  void oops_do(OopClosure* f, bool must_claim, bool clear_modified_oops = false);
+  void classes_do(KlassClosure* klass_closure);
 
-  bool is_alive(BoolObjectClosure* is_alive_closure) const;
-
-  // Accessors
-  Metaspace* metaspace_or_null() const     { return _metaspace; }
-
-  static ClassLoaderData* the_null_class_loader_data() {
-    return _the_null_class_loader_data;
-  }
-
-  Mutex* metaspace_lock() const { return _metaspace_lock; }
-
-  bool is_anonymous() const { return _is_anonymous; }
-
-  static void init_null_class_loader_data() {
-    assert(_the_null_class_loader_data == NULL, "cannot initialize twice");
-    assert(ClassLoaderDataGraph::_head == NULL, "cannot initialize twice");
-
-    // We explicitly initialize the Dependencies object at a later phase in the initialization
-    _the_null_class_loader_data = new ClassLoaderData(Handle(), false, Dependencies());
-    ClassLoaderDataGraph::_head = _the_null_class_loader_data;
-    assert(_the_null_class_loader_data->is_the_null_class_loader_data(), "Must be");
-  }
-
-  bool is_the_null_class_loader_data() const {
-    return this == _the_null_class_loader_data;
-  }
-  bool is_system_class_loader_data() const;
-  bool is_platform_class_loader_data() const;
-  bool is_builtin_class_loader_data() const;
-
-  // The Metaspace is created lazily so may be NULL.  This
-  // method will allocate a Metaspace if needed.
-  Metaspace* metaspace_non_null();
+  void record_modified_oops() { _modified_oops = true; }
+  bool has_modified_oops() const { return _modified_oops; }
 
-  oop class_loader() const      { return _class_loader; }
+  void accumulate_modified_oops() { if (has_modified_oops()) _accumulated_modified_oops = true; }
+  void clear_accumulated_modified_oops() { _accumulated_modified_oops = false; }
+  bool has_accumulated_modified_oops() const { return _accumulated_modified_oops; }
 
+  bool is_alive(BoolObjectClosure* is_alive_closure) const;
   // The object the GC is using to keep this ClassLoaderData alive.
   oop keep_alive_object() const;
+  // Used to refcount an anonymous class's CLD in order to
+  // indicate their aliveness without a keep_alive_object().
+  void inc_keep_alive();
+  void dec_keep_alive();
 
   // Returns true if this class loader data is for a loader going away.
   bool is_unloading() const     {
     assert(!(is_the_null_class_loader_data() && _unloading), "The null class loader can never be unloaded");
     return _unloading;
   }
 
-  // Used to refcount an anonymous class's CLD in order to
-  // indicate their aliveness without a keep_alive_object().
-  void inc_keep_alive();
-  void dec_keep_alive();
+  void clear_claimed() { _claimed = 0; }
+  bool claimed() const { return _claimed == 1; }
+  bool claim();
 
-  inline unsigned int identity_hash() const { return (unsigned int)(((intptr_t)this) >> 3); }
+  // The Metaspace is created lazily so may be NULL. This
+  // method will allocate a Metaspace if needed.
+  Metaspace* metaspace_non_null();
+  Mutex* metaspace_lock() const { return _metaspace_lock; }
+  Metaspace* metaspace_or_null() const { return _metaspace; }
 
-  void oops_do(OopClosure* f, bool must_claim, bool clear_modified_oops = false);
+  bool is_the_null_class_loader_data() const { return this == _the_null_class_loader_data; }
+  bool is_system_class_loader_data() const;
+  bool is_platform_class_loader_data() const;
+  bool is_builtin_class_loader_data() const;
+  bool is_anonymous() const { return _is_anonymous; }
+
+  oop class_loader() const { return _class_loader; }
+  const char* loader_name();
+  unsigned int identity_hash() const { return (unsigned int)(((intptr_t)this) >> 3); }
+  // Loaded class dictionary
+  Dictionary* dictionary() { return _dictionary; }
 
-  void classes_do(KlassClosure* klass_closure);
   Klass* klasses() { return _klasses; }
+  PackageEntryTable* packages() { return _packages; }
+  ModuleEntry* unnamed_module() { return _unnamed_module; }
+  ModuleEntryTable* modules();
+  bool modules_defined() { return (_modules != NULL); }
 
   JNIMethodBlock* jmethod_ids() const              { return _jmethod_ids; }
   void set_jmethod_ids(JNIMethodBlock* new_block)  { _jmethod_ids = new_block; }
 
-  void print()                                     { print_on(tty); }
-  void print_on(outputStream* out) const;
-  void print_value()                               { print_value_on(tty); }
-  void print_value_on(outputStream* out) const;
-  void dump(outputStream * const out) PRODUCT_RETURN;
-  void verify();
-  const char* loader_name();
-
   OopHandle add_handle(Handle h);
   void remove_handle(OopHandle h);
   void init_handle_locked(OopHandle& pd, Handle h);  // used for concurrent access to ModuleEntry::_pd field
   void add_class(Klass* k, bool publicize = true);
   void remove_class(Klass* k);
   bool contains_klass(Klass* k);
   void record_dependency(const Klass* to, TRAPS);
-  void init_dependencies(TRAPS);
-  PackageEntryTable* packages() { return _packages; }
-  ModuleEntry* unnamed_module() { return _unnamed_module; }
-  ModuleEntryTable* modules();
-  bool modules_defined() { return (_modules != NULL); }
+  void add_to_deallocate_list(Metadata* m);
 
-  // Loaded class dictionary
-  Dictionary* dictionary() const { return _dictionary; }
+  TRACE_DEFINE_TRACE_ID_METHODS;
 
-  void add_to_deallocate_list(Metadata* m);
+  void print() { print_on(tty); }
+  void print_on(outputStream* out) const;
+  void print_value() { print_value_on(tty); }
+  void print_value_on(outputStream* out) const;
+  void dump(outputStream * const out) PRODUCT_RETURN;
+  NOT_PRODUCT(void verify();)
 
+  static void init_null_class_loader_data();
+  static ClassLoaderData* the_null_class_loader_data() { return _the_null_class_loader_data; }
   static ClassLoaderData* class_loader_data(oop loader);
   static ClassLoaderData* class_loader_data_or_null(oop loader);
   static ClassLoaderData* anonymous_class_loader_data(oop loader, TRAPS);
-  static void print_loader(ClassLoaderData *loader_data, outputStream *out);
-
-  TRACE_DEFINE_TRACE_ID_METHODS;
 };
 
 // An iterator that distributes Klasses to parallel worker threads.
 class ClassLoaderDataGraphKlassIteratorAtomic : public StackObj {
+ private:
  Klass* volatile _next_klass;
  public:
   ClassLoaderDataGraphKlassIteratorAtomic();
   Klass* next_klass();
- private:
   static Klass* next_klass_in_cldg(Klass* klass);
 };
 
 class ClassLoaderDataGraphMetaspaceIterator : public StackObj {
+ private:
   ClassLoaderData* _data;
  public:
   ClassLoaderDataGraphMetaspaceIterator();
-  ~ClassLoaderDataGraphMetaspaceIterator();
   bool repeat() { return _data != NULL; }
   Metaspace* get_next() {
     assert(_data != NULL, "Should not be NULL in call to the iterator");
     Metaspace* result = _data->metaspace_or_null();
     _data = _data->next();

@@ -435,6 +379,7 @@
     // there is no guarantee that there will be a non-null result
     // down the list so the caller is going to have to check.
     return result;
   }
 };
+
 #endif // SHARE_VM_CLASSFILE_CLASSLOADERDATA_HPP
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