42 

    43   bool      _dictionary_walk;

    43 public:

    44   LoadedClassesClosure(Thread* thread, JvmtiEnv* env) : _env(env), _cur_thread(thread) {

    45     assert(_cur_thread == Thread::current(), "must be current thread");

    46   }

    47 

    48   void do_klass(Klass* k) {

    49     // Collect all jclasses

    50     _classStack.push((jclass) _env->jni_reference(Handle(_cur_thread, k->java_mirror())));

    51   }

    73 // The closure for GetClassLoaderClasses

    64 public:

    74 class JvmtiGetLoadedClassesClosure : public StackObj {

    65   LoadedClassesClosure(JvmtiEnv* env, bool dictionary_walk) :

    75   // Since the ClassLoaderDataGraph::dictionary_all_entries_do callback

    66       _env(env),

    76   // doesn't pass a closureData pointer,

    67       _cur_thread(Thread::current()),

    77   // we use a thread-local slot to hold a pointer to

    68       _dictionary_walk(dictionary_walk) {

    78   // a stack allocated instance of this structure.

    79  private:

    80   jobject _initiatingLoader;

    81   int     _count;

    82   Handle* _list;

    83   int     _index;

    84 

    85  private:

    86   // Getting and setting the thread local pointer

    87   static JvmtiGetLoadedClassesClosure* get_this() {

    88     JvmtiGetLoadedClassesClosure* result = NULL;

    89     JavaThread* thread = JavaThread::current();

    90     result = thread->get_jvmti_get_loaded_classes_closure();

    91     return result;

    92   }

    93   static void set_this(JvmtiGetLoadedClassesClosure* that) {

    94     JavaThread* thread = JavaThread::current();

    95     thread->set_jvmti_get_loaded_classes_closure(that);

    98  public:

    71   void do_klass(Klass* k) {

    99   // Constructor/Destructor

    72     // Collect all jclasses

   100   JvmtiGetLoadedClassesClosure() {

    73     _classStack.push((jclass) _env->jni_reference(Handle(_cur_thread, k->java_mirror())));

   101     JvmtiGetLoadedClassesClosure* that = get_this();

    74     if (_dictionary_walk) {

   102     assert(that == NULL, "JvmtiGetLoadedClassesClosure in use");

    75       // Collect array classes this way when walking the dictionary (because array classes are

   103     _initiatingLoader = NULL;

    76       // not in the dictionary).

   104     _count = 0;

    77       for (Klass* l = k->array_klass_or_null(); l != NULL; l = l->array_klass_or_null()) {

   105     _list = NULL;

    78         _classStack.push((jclass) _env->jni_reference(Handle(_cur_thread, l->java_mirror())));

   106     _index = 0;

   107     set_this(this);

   108   }

   109 

   110   JvmtiGetLoadedClassesClosure(jobject initiatingLoader) {

   111     JvmtiGetLoadedClassesClosure* that = get_this();

   112     assert(that == NULL, "JvmtiGetLoadedClassesClosure in use");

   113     _initiatingLoader = initiatingLoader;

   114     _count = 0;

   115     _list = NULL;

   116     _index = 0;

   117     set_this(this);

   118   }

   119 

   120   ~JvmtiGetLoadedClassesClosure() {

   121     JvmtiGetLoadedClassesClosure* that = get_this();

   122     assert(that != NULL, "JvmtiGetLoadedClassesClosure not found");

   123     set_this(NULL);

   124     _initiatingLoader = NULL;

   125     _count = 0;

   126     if (_list != NULL) {

   127       FreeHeap(_list);

   128       _list = NULL;

   129     }

   130     _index = 0;

   131   }

   132 

   133   // Accessors.

   134   jobject get_initiatingLoader() {

   135     return _initiatingLoader;

   136   }

   137 

   138   int get_count() {

   139     return _count;

   140   }

   141 

   142   void set_count(int value) {

   143     _count = value;

   144   }

   145 

   146   Handle* get_list() {

   147     return _list;

   148   }

   149 

   150   void set_list(Handle* value) {

   151     _list = value;

   152   }

   153 

   154   int get_index() {

   155     return _index;

   156   }

   157 

   158   void set_index(int value) {

   159     _index = value;

   160   }

   161 

   162   Handle get_element(int index) {

   163     if ((_list != NULL) && (index < _count)) {

   164       return _list[index];

   165     } else {

   166       assert(false, "empty get_element");

   167       return Handle();

   168     }

   169   }

   170 

   171   void set_element(int index, Handle value) {

   172     if ((_list != NULL) && (index < _count)) {

   173       _list[index] = value;

   174     } else {

   175       assert(false, "bad set_element");

   176     }

   177   }

   178 

   179   // Other predicates

   180   bool available() {

   181     return (_list != NULL);

   182   }

   183 

   184 #ifdef ASSERT

   185   // For debugging.

   186   void check(int limit) {

   187     for (int i = 0; i < limit; i += 1) {

   188       assert(Universe::heap()->is_in(get_element(i)()), "check fails");

   189     }

   190   }

   191 #endif

   192 

   193   // Public methods that get called within the scope of the closure

   194   void allocate() {

   195     _list = NEW_C_HEAP_ARRAY(Handle, _count, mtInternal);

   196     assert(_list != NULL, "Out of memory");

   197     if (_list == NULL) {

   198       _count = 0;

   199     }

   200   }

   201 

   202   void extract(JvmtiEnv *env, jclass* result) {

   203     for (int index = 0; index < _count; index += 1) {

   204       result[index] = (jclass) env->jni_reference(get_element(index));

   205     }

   206   }

   207 

   208   static void increment_with_loader(InstanceKlass* k, ClassLoaderData* loader_data) {

   209     JvmtiGetLoadedClassesClosure* that = JvmtiGetLoadedClassesClosure::get_this();

   210     oop class_loader = loader_data->class_loader();

   211     if (class_loader == JNIHandles::resolve(that->get_initiatingLoader())) {

   212       for (Klass* l = k; l != NULL; l = l->array_klass_or_null()) {

   213         that->set_count(that->get_count() + 1);

   218   static void add_with_loader(InstanceKlass* k, ClassLoaderData* loader_data) {

    83   jvmtiError get_result(JvmtiEnv *env, jint* classCountPtr, jclass** classesPtr) {

   219     JvmtiGetLoadedClassesClosure* that = JvmtiGetLoadedClassesClosure::get_this();

    84     // Return results by extracting the collected contents into a list

   220     if (that->available()) {

    85     // allocated via JvmtiEnv

   221       oop class_loader = loader_data->class_loader();

    86     jclass* result_list;

   222       if (class_loader == JNIHandles::resolve(that->get_initiatingLoader())) {

    87     jvmtiError error = env->Allocate(get_count() * sizeof(jclass),

   223         Thread *thread = Thread::current();

    88                                (unsigned char**)&result_list);

   224         for (Klass* l = k; l != NULL; l = l->array_klass_or_null()) {

    89 

   225           Handle mirror(thread, l->java_mirror());

    90     if (error == JVMTI_ERROR_NONE) {

   226           that->set_element(that->get_index(), mirror);

    91       int count = extract(result_list);

   227           that->set_index(that->get_index() + 1);

    92       *classCountPtr = count;

   228         }

    93       *classesPtr = result_list;

   229       }

   231   }

    95     return error;

   232 

   233   // increment the count for the given basic type array class (and any

   234   // multi-dimensional arrays). For example, for [B we check for

   235   // [[B, [[[B, .. and the count is incremented for each one that exists.

   236   static void increment_for_basic_type_arrays(Klass* k) {

   237     JvmtiGetLoadedClassesClosure* that = JvmtiGetLoadedClassesClosure::get_this();

   238     assert(that != NULL, "no JvmtiGetLoadedClassesClosure");

   239     for (Klass* l = k; l != NULL; l = l->array_klass_or_null()) {

   240       that->set_count(that->get_count() + 1);

   241     }

   242   }

   243 

   244   // add the basic type array class and its multi-dimensional array classes to the list

   245   static void add_for_basic_type_arrays(Klass* k) {

   246     JvmtiGetLoadedClassesClosure* that = JvmtiGetLoadedClassesClosure::get_this();

   247     assert(that != NULL, "no JvmtiGetLoadedClassesClosure");

   248     assert(that->available(), "no list");

   249     Thread *thread = Thread::current();

   250     for (Klass* l = k; l != NULL; l = l->array_klass_or_null()) {

   251       Handle mirror(thread, l->java_mirror());

   252       that->set_element(that->get_index(), mirror);

   253       that->set_index(that->get_index() + 1);

   254     }

   262   LoadedClassesClosure closure(Thread::current(), env);

   102   LoadedClassesClosure closure(env, false);

   273   // Return results by extracting the collected contents into a list

   113   return closure.get_result(env, classCountPtr, classesPtr);

   274   // allocated via JvmtiEnv

   275   jclass* result_list;

   276   jvmtiError error = env->Allocate(closure.get_count() * sizeof(jclass),

   277                                (unsigned char**)&result_list);

   278 

   279   if (error == JVMTI_ERROR_NONE) {

   280     int count = closure.extract(result_list);

   281     *classCountPtr = count;

   282     *classesPtr = result_list;

   283   }

   284   return error;

   290   // Since ClassLoaderDataGraph::dictionary_all_entries_do only takes a function pointer

   119 

   291   // and doesn't call back with a closure data pointer,

   120   LoadedClassesClosure closure(env, true);

   292   // we can only pass static methods.

   293   JvmtiGetLoadedClassesClosure closure(initiatingLoader);

   296     // array classes aren't created, and SystemDictionary_lock to ensure that

   123     // array classes aren't created during this walk.

   297     // classes aren't added to the class loader data dictionaries.

   300     // First, count the classes in the class loader data dictionaries which have this loader recorded

   126     oop loader = JNIHandles::resolve(initiatingLoader);

   301     // as an initiating loader. For basic type arrays this information is not recorded

   127     // All classes loaded from this loader as initiating loader are

   302     // so GetClassLoaderClasses will return all of the basic type arrays. This is okay

   128     // requested, so only need to walk this loader's ClassLoaderData

   303     // because the defining loader for basic type arrays is always the boot class loader

   129     // dictionary, or the NULL ClassLoaderData dictionary for bootstrap loader.

   304     // and these classes are "visible" to all loaders.

   130     if (loader != NULL) {

   305     ClassLoaderDataGraph::dictionary_all_entries_do(&JvmtiGetLoadedClassesClosure::increment_with_loader);

   131       ClassLoaderData* data = java_lang_ClassLoader::loader_data(loader);

   306     Universe::basic_type_classes_do(&JvmtiGetLoadedClassesClosure::increment_for_basic_type_arrays);

   132       // ClassLoader may not be used yet for loading.

   307     // Next, fill in the classes

   133       if (data != NULL && data->dictionary() != NULL) {

   308     closure.allocate();

   134         data->dictionary()->all_entries_do(&closure);

   309     ClassLoaderDataGraph::dictionary_all_entries_do(&JvmtiGetLoadedClassesClosure::add_with_loader);

   135       }

   310     Universe::basic_type_classes_do(&JvmtiGetLoadedClassesClosure::add_for_basic_type_arrays);

   136     } else {

   311     // Drop the SystemDictionary_lock, so the results could be wrong from here,

   137       ClassLoaderData::the_null_class_loader_data()->dictionary()->all_entries_do(&closure);

   312     // but we still have a snapshot.

   138     }

   139     // Get basic arrays for all loaders.

   140     Universe::basic_type_classes_do(&closure);

   314   // Post results

   142 

   315   jclass* result_list;

   143   return closure.get_result(env, classCountPtr, classesPtr);

   316   jvmtiError err = env->Allocate(closure.get_count() * sizeof(jclass),

   317                                  (unsigned char**)&result_list);

   318   if (err != JVMTI_ERROR_NONE) {

   319     return err;

   320   }

   321   closure.extract(env, result_list);

   322   *classCountPtr = closure.get_count();

   323   *classesPtr = result_list;

   324   return JVMTI_ERROR_NONE;