| /* |
| * Copyright (c) 2003, 2017, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| #include "precompiled.hpp" |
| #include "classfile/systemDictionary.hpp" |
| #include "gc/shared/collectedHeap.hpp" |
| #include "memory/universe.inline.hpp" |
| #include "prims/jvmtiGetLoadedClasses.hpp" |
| #include "runtime/thread.hpp" |
| #include "utilities/stack.inline.hpp" |
| |
| |
| // The closure for GetLoadedClasses |
| class LoadedClassesClosure : public KlassClosure { |
| private: |
| Stack<jclass, mtInternal> _classStack; |
| JvmtiEnv* _env; |
| Thread* _cur_thread; |
| |
| public: |
| LoadedClassesClosure(Thread* thread, JvmtiEnv* env) : _cur_thread(thread), _env(env) { |
| assert(_cur_thread == Thread::current(), "must be current thread"); |
| } |
| |
| void do_klass(Klass* k) { |
| // Collect all jclasses |
| _classStack.push((jclass) _env->jni_reference(Handle(_cur_thread, k->java_mirror()))); |
| } |
| |
| int extract(jclass* result_list) { |
| // The size of the Stack will be 0 after extract, so get it here |
| int count = (int)_classStack.size(); |
| int i = count; |
| |
| // Pop all jclasses, fill backwards |
| while (!_classStack.is_empty()) { |
| result_list[--i] = _classStack.pop(); |
| } |
| |
| // Return the number of elements written |
| return count; |
| } |
| |
| // Return current size of the Stack |
| int get_count() { |
| return (int)_classStack.size(); |
| } |
| }; |
| |
| // The closure for GetClassLoaderClasses |
| class JvmtiGetLoadedClassesClosure : public StackObj { |
| // Since the ClassLoaderDataGraph::dictionary_all_entries_do callback |
| // doesn't pass a closureData pointer, |
| // we use a thread-local slot to hold a pointer to |
| // a stack allocated instance of this structure. |
| private: |
| jobject _initiatingLoader; |
| int _count; |
| Handle* _list; |
| int _index; |
| |
| private: |
| // Getting and setting the thread local pointer |
| static JvmtiGetLoadedClassesClosure* get_this() { |
| JvmtiGetLoadedClassesClosure* result = NULL; |
| JavaThread* thread = JavaThread::current(); |
| result = thread->get_jvmti_get_loaded_classes_closure(); |
| return result; |
| } |
| static void set_this(JvmtiGetLoadedClassesClosure* that) { |
| JavaThread* thread = JavaThread::current(); |
| thread->set_jvmti_get_loaded_classes_closure(that); |
| } |
| |
| public: |
| // Constructor/Destructor |
| JvmtiGetLoadedClassesClosure() { |
| JvmtiGetLoadedClassesClosure* that = get_this(); |
| assert(that == NULL, "JvmtiGetLoadedClassesClosure in use"); |
| _initiatingLoader = NULL; |
| _count = 0; |
| _list = NULL; |
| _index = 0; |
| set_this(this); |
| } |
| |
| JvmtiGetLoadedClassesClosure(jobject initiatingLoader) { |
| JvmtiGetLoadedClassesClosure* that = get_this(); |
| assert(that == NULL, "JvmtiGetLoadedClassesClosure in use"); |
| _initiatingLoader = initiatingLoader; |
| _count = 0; |
| _list = NULL; |
| _index = 0; |
| set_this(this); |
| } |
| |
| ~JvmtiGetLoadedClassesClosure() { |
| JvmtiGetLoadedClassesClosure* that = get_this(); |
| assert(that != NULL, "JvmtiGetLoadedClassesClosure not found"); |
| set_this(NULL); |
| _initiatingLoader = NULL; |
| _count = 0; |
| if (_list != NULL) { |
| FreeHeap(_list); |
| _list = NULL; |
| } |
| _index = 0; |
| } |
| |
| // Accessors. |
| jobject get_initiatingLoader() { |
| return _initiatingLoader; |
| } |
| |
| int get_count() { |
| return _count; |
| } |
| |
| void set_count(int value) { |
| _count = value; |
| } |
| |
| Handle* get_list() { |
| return _list; |
| } |
| |
| void set_list(Handle* value) { |
| _list = value; |
| } |
| |
| int get_index() { |
| return _index; |
| } |
| |
| void set_index(int value) { |
| _index = value; |
| } |
| |
| Handle get_element(int index) { |
| if ((_list != NULL) && (index < _count)) { |
| return _list[index]; |
| } else { |
| assert(false, "empty get_element"); |
| return Handle(); |
| } |
| } |
| |
| void set_element(int index, Handle value) { |
| if ((_list != NULL) && (index < _count)) { |
| _list[index] = value; |
| } else { |
| assert(false, "bad set_element"); |
| } |
| } |
| |
| // Other predicates |
| bool available() { |
| return (_list != NULL); |
| } |
| |
| #ifdef ASSERT |
| // For debugging. |
| void check(int limit) { |
| for (int i = 0; i < limit; i += 1) { |
| assert(Universe::heap()->is_in(get_element(i)()), "check fails"); |
| } |
| } |
| #endif |
| |
| // Public methods that get called within the scope of the closure |
| void allocate() { |
| _list = NEW_C_HEAP_ARRAY(Handle, _count, mtInternal); |
| assert(_list != NULL, "Out of memory"); |
| if (_list == NULL) { |
| _count = 0; |
| } |
| } |
| |
| void extract(JvmtiEnv *env, jclass* result) { |
| for (int index = 0; index < _count; index += 1) { |
| result[index] = (jclass) env->jni_reference(get_element(index)); |
| } |
| } |
| |
| static void increment_with_loader(InstanceKlass* k, ClassLoaderData* loader_data) { |
| JvmtiGetLoadedClassesClosure* that = JvmtiGetLoadedClassesClosure::get_this(); |
| oop class_loader = loader_data->class_loader(); |
| if (class_loader == JNIHandles::resolve(that->get_initiatingLoader())) { |
| for (Klass* l = k; l != NULL; l = l->array_klass_or_null()) { |
| that->set_count(that->get_count() + 1); |
| } |
| } |
| } |
| |
| static void add_with_loader(InstanceKlass* k, ClassLoaderData* loader_data) { |
| JvmtiGetLoadedClassesClosure* that = JvmtiGetLoadedClassesClosure::get_this(); |
| if (that->available()) { |
| oop class_loader = loader_data->class_loader(); |
| if (class_loader == JNIHandles::resolve(that->get_initiatingLoader())) { |
| Thread *thread = Thread::current(); |
| for (Klass* l = k; l != NULL; l = l->array_klass_or_null()) { |
| Handle mirror(thread, l->java_mirror()); |
| that->set_element(that->get_index(), mirror); |
| that->set_index(that->get_index() + 1); |
| } |
| } |
| } |
| } |
| |
| // increment the count for the given basic type array class (and any |
| // multi-dimensional arrays). For example, for [B we check for |
| // [[B, [[[B, .. and the count is incremented for each one that exists. |
| static void increment_for_basic_type_arrays(Klass* k) { |
| JvmtiGetLoadedClassesClosure* that = JvmtiGetLoadedClassesClosure::get_this(); |
| assert(that != NULL, "no JvmtiGetLoadedClassesClosure"); |
| for (Klass* l = k; l != NULL; l = l->array_klass_or_null()) { |
| that->set_count(that->get_count() + 1); |
| } |
| } |
| |
| // add the basic type array class and its multi-dimensional array classes to the list |
| static void add_for_basic_type_arrays(Klass* k) { |
| JvmtiGetLoadedClassesClosure* that = JvmtiGetLoadedClassesClosure::get_this(); |
| assert(that != NULL, "no JvmtiGetLoadedClassesClosure"); |
| assert(that->available(), "no list"); |
| Thread *thread = Thread::current(); |
| for (Klass* l = k; l != NULL; l = l->array_klass_or_null()) { |
| Handle mirror(thread, l->java_mirror()); |
| that->set_element(that->get_index(), mirror); |
| that->set_index(that->get_index() + 1); |
| } |
| } |
| }; |
| |
| |
| jvmtiError |
| JvmtiGetLoadedClasses::getLoadedClasses(JvmtiEnv *env, jint* classCountPtr, jclass** classesPtr) { |
| |
| LoadedClassesClosure closure(Thread::current(), env); |
| { |
| // To get a consistent list of classes we need MultiArray_lock to ensure |
| // array classes aren't created. |
| MutexLocker ma(MultiArray_lock); |
| |
| // Iterate through all classes in ClassLoaderDataGraph |
| // and collect them using the LoadedClassesClosure |
| ClassLoaderDataGraph::loaded_classes_do(&closure); |
| } |
| |
| // Return results by extracting the collected contents into a list |
| // allocated via JvmtiEnv |
| jclass* result_list; |
| jvmtiError error = env->Allocate(closure.get_count() * sizeof(jclass), |
| (unsigned char**)&result_list); |
| |
| if (error == JVMTI_ERROR_NONE) { |
| int count = closure.extract(result_list); |
| *classCountPtr = count; |
| *classesPtr = result_list; |
| } |
| return error; |
| } |
| |
| jvmtiError |
| JvmtiGetLoadedClasses::getClassLoaderClasses(JvmtiEnv *env, jobject initiatingLoader, |
| jint* classCountPtr, jclass** classesPtr) { |
| // Since ClassLoaderDataGraph::dictionary_all_entries_do only takes a function pointer |
| // and doesn't call back with a closure data pointer, |
| // we can only pass static methods. |
| JvmtiGetLoadedClassesClosure closure(initiatingLoader); |
| { |
| // To get a consistent list of classes we need MultiArray_lock to ensure |
| // array classes aren't created, and SystemDictionary_lock to ensure that |
| // classes aren't added to the class loader data dictionaries. |
| MutexLocker ma(MultiArray_lock); |
| MutexLocker sd(SystemDictionary_lock); |
| // First, count the classes in the class loader data dictionaries which have this loader recorded |
| // as an initiating loader. For basic type arrays this information is not recorded |
| // so GetClassLoaderClasses will return all of the basic type arrays. This is okay |
| // because the defining loader for basic type arrays is always the boot class loader |
| // and these classes are "visible" to all loaders. |
| ClassLoaderDataGraph::dictionary_all_entries_do(&JvmtiGetLoadedClassesClosure::increment_with_loader); |
| Universe::basic_type_classes_do(&JvmtiGetLoadedClassesClosure::increment_for_basic_type_arrays); |
| // Next, fill in the classes |
| closure.allocate(); |
| ClassLoaderDataGraph::dictionary_all_entries_do(&JvmtiGetLoadedClassesClosure::add_with_loader); |
| Universe::basic_type_classes_do(&JvmtiGetLoadedClassesClosure::add_for_basic_type_arrays); |
| // Drop the SystemDictionary_lock, so the results could be wrong from here, |
| // but we still have a snapshot. |
| } |
| // Post results |
| jclass* result_list; |
| jvmtiError err = env->Allocate(closure.get_count() * sizeof(jclass), |
| (unsigned char**)&result_list); |
| if (err != JVMTI_ERROR_NONE) { |
| return err; |
| } |
| closure.extract(env, result_list); |
| *classCountPtr = closure.get_count(); |
| *classesPtr = result_list; |
| return JVMTI_ERROR_NONE; |
| } |