aoqi@0: /*
aoqi@0:  * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved.
aoqi@0:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
aoqi@0:  *
aoqi@0:  * This code is free software; you can redistribute it and/or modify it
aoqi@0:  * under the terms of the GNU General Public License version 2 only, as
aoqi@0:  * published by the Free Software Foundation.
aoqi@0:  *
aoqi@0:  * This code is distributed in the hope that it will be useful, but WITHOUT
aoqi@0:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
aoqi@0:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
aoqi@0:  * version 2 for more details (a copy is included in the LICENSE file that
aoqi@0:  * accompanied this code).
aoqi@0:  *
aoqi@0:  * You should have received a copy of the GNU General Public License version
aoqi@0:  * 2 along with this work; if not, write to the Free Software Foundation,
aoqi@0:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
aoqi@0:  *
aoqi@0:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
aoqi@0:  * or visit www.oracle.com if you need additional information or have any
aoqi@0:  * questions.
aoqi@0:  *
aoqi@0:  */
aoqi@0: 
aoqi@0: #include "precompiled.hpp"
aoqi@0: #include "classfile/systemDictionary.hpp"
aoqi@0: #include "memory/universe.inline.hpp"
aoqi@0: #include "prims/jvmtiGetLoadedClasses.hpp"
aoqi@0: #include "runtime/thread.hpp"
aoqi@0: 
aoqi@0: 
aoqi@0: // The closure for GetLoadedClasses
aoqi@0: class LoadedClassesClosure : public KlassClosure {
aoqi@0: private:
aoqi@0:   Stack<jclass, mtInternal> _classStack;
aoqi@0:   JvmtiEnv* _env;
aoqi@0: 
aoqi@0: public:
aoqi@0:   LoadedClassesClosure(JvmtiEnv* env) {
aoqi@0:     _env = env;
aoqi@0:   }
aoqi@0: 
aoqi@0:   void do_klass(Klass* k) {
aoqi@0:     // Collect all jclasses
aoqi@0:     _classStack.push((jclass) _env->jni_reference(k->java_mirror()));
aoqi@0:   }
aoqi@0: 
aoqi@0:   int extract(jclass* result_list) {
aoqi@0:     // The size of the Stack will be 0 after extract, so get it here
aoqi@0:     int count = (int)_classStack.size();
aoqi@0:     int i = count;
aoqi@0: 
aoqi@0:     // Pop all jclasses, fill backwards
aoqi@0:     while (!_classStack.is_empty()) {
aoqi@0:       result_list[--i] = _classStack.pop();
aoqi@0:     }
aoqi@0: 
aoqi@0:     // Return the number of elements written
aoqi@0:     return count;
aoqi@0:   }
aoqi@0: 
aoqi@0:   // Return current size of the Stack
aoqi@0:   int get_count() {
aoqi@0:     return (int)_classStack.size();
aoqi@0:   }
aoqi@0: };
aoqi@0: 
aoqi@0: // The closure for GetClassLoaderClasses
aoqi@0: class JvmtiGetLoadedClassesClosure : public StackObj {
aoqi@0:   // Since the SystemDictionary::classes_do callback
aoqi@0:   // doesn't pass a closureData pointer,
aoqi@0:   // we use a thread-local slot to hold a pointer to
aoqi@0:   // a stack allocated instance of this structure.
aoqi@0:  private:
aoqi@0:   jobject _initiatingLoader;
aoqi@0:   int     _count;
aoqi@0:   Handle* _list;
aoqi@0:   int     _index;
aoqi@0: 
aoqi@0:  private:
aoqi@0:   // Getting and setting the thread local pointer
aoqi@0:   static JvmtiGetLoadedClassesClosure* get_this() {
aoqi@0:     JvmtiGetLoadedClassesClosure* result = NULL;
aoqi@0:     JavaThread* thread = JavaThread::current();
aoqi@0:     result = thread->get_jvmti_get_loaded_classes_closure();
aoqi@0:     return result;
aoqi@0:   }
aoqi@0:   static void set_this(JvmtiGetLoadedClassesClosure* that) {
aoqi@0:     JavaThread* thread = JavaThread::current();
aoqi@0:     thread->set_jvmti_get_loaded_classes_closure(that);
aoqi@0:   }
aoqi@0: 
aoqi@0:  public:
aoqi@0:   // Constructor/Destructor
aoqi@0:   JvmtiGetLoadedClassesClosure() {
aoqi@0:     JvmtiGetLoadedClassesClosure* that = get_this();
aoqi@0:     assert(that == NULL, "JvmtiGetLoadedClassesClosure in use");
aoqi@0:     _initiatingLoader = NULL;
aoqi@0:     _count = 0;
aoqi@0:     _list = NULL;
aoqi@0:     _index = 0;
aoqi@0:     set_this(this);
aoqi@0:   }
aoqi@0: 
aoqi@0:   JvmtiGetLoadedClassesClosure(jobject initiatingLoader) {
aoqi@0:     JvmtiGetLoadedClassesClosure* that = get_this();
aoqi@0:     assert(that == NULL, "JvmtiGetLoadedClassesClosure in use");
aoqi@0:     _initiatingLoader = initiatingLoader;
aoqi@0:     _count = 0;
aoqi@0:     _list = NULL;
aoqi@0:     _index = 0;
aoqi@0:     set_this(this);
aoqi@0:   }
aoqi@0: 
aoqi@0:   ~JvmtiGetLoadedClassesClosure() {
aoqi@0:     JvmtiGetLoadedClassesClosure* that = get_this();
aoqi@0:     assert(that != NULL, "JvmtiGetLoadedClassesClosure not found");
aoqi@0:     set_this(NULL);
aoqi@0:     _initiatingLoader = NULL;
aoqi@0:     _count = 0;
aoqi@0:     if (_list != NULL) {
aoqi@0:       FreeHeap(_list);
aoqi@0:       _list = NULL;
aoqi@0:     }
aoqi@0:     _index = 0;
aoqi@0:   }
aoqi@0: 
aoqi@0:   // Accessors.
aoqi@0:   jobject get_initiatingLoader() {
aoqi@0:     return _initiatingLoader;
aoqi@0:   }
aoqi@0: 
aoqi@0:   int get_count() {
aoqi@0:     return _count;
aoqi@0:   }
aoqi@0: 
aoqi@0:   void set_count(int value) {
aoqi@0:     _count = value;
aoqi@0:   }
aoqi@0: 
aoqi@0:   Handle* get_list() {
aoqi@0:     return _list;
aoqi@0:   }
aoqi@0: 
aoqi@0:   void set_list(Handle* value) {
aoqi@0:     _list = value;
aoqi@0:   }
aoqi@0: 
aoqi@0:   int get_index() {
aoqi@0:     return _index;
aoqi@0:   }
aoqi@0: 
aoqi@0:   void set_index(int value) {
aoqi@0:     _index = value;
aoqi@0:   }
aoqi@0: 
aoqi@0:   Handle get_element(int index) {
aoqi@0:     if ((_list != NULL) && (index < _count)) {
aoqi@0:       return _list[index];
aoqi@0:     } else {
aoqi@0:       assert(false, "empty get_element");
aoqi@0:       return Handle();
aoqi@0:     }
aoqi@0:   }
aoqi@0: 
aoqi@0:   void set_element(int index, Handle value) {
aoqi@0:     if ((_list != NULL) && (index < _count)) {
aoqi@0:       _list[index] = value;
aoqi@0:     } else {
aoqi@0:       assert(false, "bad set_element");
aoqi@0:     }
aoqi@0:   }
aoqi@0: 
aoqi@0:   // Other predicates
aoqi@0:   bool available() {
aoqi@0:     return (_list != NULL);
aoqi@0:   }
aoqi@0: 
aoqi@0: #ifdef ASSERT
aoqi@0:   // For debugging.
aoqi@0:   void check(int limit) {
aoqi@0:     for (int i = 0; i < limit; i += 1) {
aoqi@0:       assert(Universe::heap()->is_in(get_element(i)()), "check fails");
aoqi@0:     }
aoqi@0:   }
aoqi@0: #endif
aoqi@0: 
aoqi@0:   // Public methods that get called within the scope of the closure
aoqi@0:   void allocate() {
aoqi@0:     _list = NEW_C_HEAP_ARRAY(Handle, _count, mtInternal);
aoqi@0:     assert(_list != NULL, "Out of memory");
aoqi@0:     if (_list == NULL) {
aoqi@0:       _count = 0;
aoqi@0:     }
aoqi@0:   }
aoqi@0: 
aoqi@0:   void extract(JvmtiEnv *env, jclass* result) {
aoqi@0:     for (int index = 0; index < _count; index += 1) {
aoqi@0:       result[index] = (jclass) env->jni_reference(get_element(index));
aoqi@0:     }
aoqi@0:   }
aoqi@0: 
aoqi@0:   static void increment_with_loader(Klass* k, ClassLoaderData* loader_data) {
aoqi@0:     JvmtiGetLoadedClassesClosure* that = JvmtiGetLoadedClassesClosure::get_this();
aoqi@0:     oop class_loader = loader_data->class_loader();
aoqi@0:     if (class_loader == JNIHandles::resolve(that->get_initiatingLoader())) {
aoqi@0:       for (Klass* l = k; l != NULL; l = l->array_klass_or_null()) {
aoqi@0:         that->set_count(that->get_count() + 1);
aoqi@0:       }
aoqi@0:     }
aoqi@0:   }
aoqi@0: 
aoqi@0:   static void prim_array_increment_with_loader(Klass* array, ClassLoaderData* loader_data) {
aoqi@0:     JvmtiGetLoadedClassesClosure* that = JvmtiGetLoadedClassesClosure::get_this();
aoqi@0:     oop class_loader = loader_data->class_loader();
aoqi@0:     if (class_loader == JNIHandles::resolve(that->get_initiatingLoader())) {
aoqi@0:       that->set_count(that->get_count() + 1);
aoqi@0:     }
aoqi@0:   }
aoqi@0: 
aoqi@0:   static void add_with_loader(Klass* k, ClassLoaderData* loader_data) {
aoqi@0:     JvmtiGetLoadedClassesClosure* that = JvmtiGetLoadedClassesClosure::get_this();
aoqi@0:     if (that->available()) {
aoqi@0:       oop class_loader = loader_data->class_loader();
aoqi@0:       if (class_loader == JNIHandles::resolve(that->get_initiatingLoader())) {
aoqi@0:         for (Klass* l = k; l != NULL; l = l->array_klass_or_null()) {
aoqi@0:           oop mirror = l->java_mirror();
aoqi@0:           that->set_element(that->get_index(), mirror);
aoqi@0:           that->set_index(that->get_index() + 1);
aoqi@0:         }
aoqi@0:       }
aoqi@0:     }
aoqi@0:   }
aoqi@0: 
aoqi@0:   // increment the count for the given basic type array class (and any
aoqi@0:   // multi-dimensional arrays). For example, for [B we check for
aoqi@0:   // [[B, [[[B, .. and the count is incremented for each one that exists.
aoqi@0:   static void increment_for_basic_type_arrays(Klass* k) {
aoqi@0:     JvmtiGetLoadedClassesClosure* that = JvmtiGetLoadedClassesClosure::get_this();
aoqi@0:     assert(that != NULL, "no JvmtiGetLoadedClassesClosure");
aoqi@0:     for (Klass* l = k; l != NULL; l = l->array_klass_or_null()) {
aoqi@0:       that->set_count(that->get_count() + 1);
aoqi@0:     }
aoqi@0:   }
aoqi@0: 
aoqi@0:   // add the basic type array class and its multi-dimensional array classes to the list
aoqi@0:   static void add_for_basic_type_arrays(Klass* k) {
aoqi@0:     JvmtiGetLoadedClassesClosure* that = JvmtiGetLoadedClassesClosure::get_this();
aoqi@0:     assert(that != NULL, "no JvmtiGetLoadedClassesClosure");
aoqi@0:     assert(that->available(), "no list");
aoqi@0:     for (Klass* l = k; l != NULL; l = l->array_klass_or_null()) {
aoqi@0:       oop mirror = l->java_mirror();
aoqi@0:       that->set_element(that->get_index(), mirror);
aoqi@0:       that->set_index(that->get_index() + 1);
aoqi@0:     }
aoqi@0:   }
aoqi@0: };
aoqi@0: 
aoqi@0: 
aoqi@0: jvmtiError
aoqi@0: JvmtiGetLoadedClasses::getLoadedClasses(JvmtiEnv *env, jint* classCountPtr, jclass** classesPtr) {
aoqi@0: 
aoqi@0:   LoadedClassesClosure closure(env);
aoqi@0:   {
aoqi@0:     // To get a consistent list of classes we need MultiArray_lock to ensure
aoqi@0:     // array classes aren't created.
aoqi@0:     MutexLocker ma(MultiArray_lock);
aoqi@0: 
aoqi@0:     // Iterate through all classes in ClassLoaderDataGraph
aoqi@0:     // and collect them using the LoadedClassesClosure
aoqi@0:     ClassLoaderDataGraph::loaded_classes_do(&closure);
aoqi@0:   }
aoqi@0: 
aoqi@0:   // Return results by extracting the collected contents into a list
aoqi@0:   // allocated via JvmtiEnv
aoqi@0:   jclass* result_list;
aoqi@0:   jvmtiError error = env->Allocate(closure.get_count() * sizeof(jclass),
aoqi@0:                                (unsigned char**)&result_list);
aoqi@0: 
aoqi@0:   if (error == JVMTI_ERROR_NONE) {
aoqi@0:     int count = closure.extract(result_list);
aoqi@0:     *classCountPtr = count;
aoqi@0:     *classesPtr = result_list;
aoqi@0:   }
aoqi@0:   return error;
aoqi@0: }
aoqi@0: 
aoqi@0: jvmtiError
aoqi@0: JvmtiGetLoadedClasses::getClassLoaderClasses(JvmtiEnv *env, jobject initiatingLoader,
aoqi@0:                                              jint* classCountPtr, jclass** classesPtr) {
aoqi@0:   // Since SystemDictionary::classes_do only takes a function pointer
aoqi@0:   // and doesn't call back with a closure data pointer,
aoqi@0:   // we can only pass static methods.
aoqi@0:   JvmtiGetLoadedClassesClosure closure(initiatingLoader);
aoqi@0:   {
aoqi@0:     // To get a consistent list of classes we need MultiArray_lock to ensure
aoqi@0:     // array classes aren't created, and SystemDictionary_lock to ensure that
aoqi@0:     // classes aren't added to the system dictionary,
aoqi@0:     MutexLocker ma(MultiArray_lock);
aoqi@0:     MutexLocker sd(SystemDictionary_lock);
aoqi@0:     // First, count the classes in the system dictionary which have this loader recorded
aoqi@0:     // as an initiating loader. For basic type arrays this information is not recorded
aoqi@0:     // so GetClassLoaderClasses will return all of the basic type arrays. This is okay
aoqi@0:     // because the defining loader for basic type arrays is always the boot class loader
aoqi@0:     // and these classes are "visible" to all loaders.
aoqi@0:     SystemDictionary::classes_do(&JvmtiGetLoadedClassesClosure::increment_with_loader);
aoqi@0:     Universe::basic_type_classes_do(&JvmtiGetLoadedClassesClosure::increment_for_basic_type_arrays);
aoqi@0:     // Next, fill in the classes
aoqi@0:     closure.allocate();
aoqi@0:     SystemDictionary::classes_do(&JvmtiGetLoadedClassesClosure::add_with_loader);
aoqi@0:     Universe::basic_type_classes_do(&JvmtiGetLoadedClassesClosure::add_for_basic_type_arrays);
aoqi@0:     // Drop the SystemDictionary_lock, so the results could be wrong from here,
aoqi@0:     // but we still have a snapshot.
aoqi@0:   }
aoqi@0:   // Post results
aoqi@0:   jclass* result_list;
aoqi@0:   jvmtiError err = env->Allocate(closure.get_count() * sizeof(jclass),
aoqi@0:                                  (unsigned char**)&result_list);
aoqi@0:   if (err != JVMTI_ERROR_NONE) {
aoqi@0:     return err;
aoqi@0:   }
aoqi@0:   closure.extract(env, result_list);
aoqi@0:   *classCountPtr = closure.get_count();
aoqi@0:   *classesPtr = result_list;
aoqi@0:   return JVMTI_ERROR_NONE;
aoqi@0: }