1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/prims/jvmtiGetLoadedClasses.cpp Wed Apr 27 01:25:04 2016 +0800
1.3 @@ -0,0 +1,326 @@
1.4 +/*
1.5 + * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.23 + * or visit www.oracle.com if you need additional information or have any
1.24 + * questions.
1.25 + *
1.26 + */
1.27 +
1.28 +#include "precompiled.hpp"
1.29 +#include "classfile/systemDictionary.hpp"
1.30 +#include "memory/universe.inline.hpp"
1.31 +#include "prims/jvmtiGetLoadedClasses.hpp"
1.32 +#include "runtime/thread.hpp"
1.33 +
1.34 +
1.35 +// The closure for GetLoadedClasses
1.36 +class LoadedClassesClosure : public KlassClosure {
1.37 +private:
1.38 + Stack<jclass, mtInternal> _classStack;
1.39 + JvmtiEnv* _env;
1.40 +
1.41 +public:
1.42 + LoadedClassesClosure(JvmtiEnv* env) {
1.43 + _env = env;
1.44 + }
1.45 +
1.46 + void do_klass(Klass* k) {
1.47 + // Collect all jclasses
1.48 + _classStack.push((jclass) _env->jni_reference(k->java_mirror()));
1.49 + }
1.50 +
1.51 + int extract(jclass* result_list) {
1.52 + // The size of the Stack will be 0 after extract, so get it here
1.53 + int count = (int)_classStack.size();
1.54 + int i = count;
1.55 +
1.56 + // Pop all jclasses, fill backwards
1.57 + while (!_classStack.is_empty()) {
1.58 + result_list[--i] = _classStack.pop();
1.59 + }
1.60 +
1.61 + // Return the number of elements written
1.62 + return count;
1.63 + }
1.64 +
1.65 + // Return current size of the Stack
1.66 + int get_count() {
1.67 + return (int)_classStack.size();
1.68 + }
1.69 +};
1.70 +
1.71 +// The closure for GetClassLoaderClasses
1.72 +class JvmtiGetLoadedClassesClosure : public StackObj {
1.73 + // Since the SystemDictionary::classes_do callback
1.74 + // doesn't pass a closureData pointer,
1.75 + // we use a thread-local slot to hold a pointer to
1.76 + // a stack allocated instance of this structure.
1.77 + private:
1.78 + jobject _initiatingLoader;
1.79 + int _count;
1.80 + Handle* _list;
1.81 + int _index;
1.82 +
1.83 + private:
1.84 + // Getting and setting the thread local pointer
1.85 + static JvmtiGetLoadedClassesClosure* get_this() {
1.86 + JvmtiGetLoadedClassesClosure* result = NULL;
1.87 + JavaThread* thread = JavaThread::current();
1.88 + result = thread->get_jvmti_get_loaded_classes_closure();
1.89 + return result;
1.90 + }
1.91 + static void set_this(JvmtiGetLoadedClassesClosure* that) {
1.92 + JavaThread* thread = JavaThread::current();
1.93 + thread->set_jvmti_get_loaded_classes_closure(that);
1.94 + }
1.95 +
1.96 + public:
1.97 + // Constructor/Destructor
1.98 + JvmtiGetLoadedClassesClosure() {
1.99 + JvmtiGetLoadedClassesClosure* that = get_this();
1.100 + assert(that == NULL, "JvmtiGetLoadedClassesClosure in use");
1.101 + _initiatingLoader = NULL;
1.102 + _count = 0;
1.103 + _list = NULL;
1.104 + _index = 0;
1.105 + set_this(this);
1.106 + }
1.107 +
1.108 + JvmtiGetLoadedClassesClosure(jobject initiatingLoader) {
1.109 + JvmtiGetLoadedClassesClosure* that = get_this();
1.110 + assert(that == NULL, "JvmtiGetLoadedClassesClosure in use");
1.111 + _initiatingLoader = initiatingLoader;
1.112 + _count = 0;
1.113 + _list = NULL;
1.114 + _index = 0;
1.115 + set_this(this);
1.116 + }
1.117 +
1.118 + ~JvmtiGetLoadedClassesClosure() {
1.119 + JvmtiGetLoadedClassesClosure* that = get_this();
1.120 + assert(that != NULL, "JvmtiGetLoadedClassesClosure not found");
1.121 + set_this(NULL);
1.122 + _initiatingLoader = NULL;
1.123 + _count = 0;
1.124 + if (_list != NULL) {
1.125 + FreeHeap(_list);
1.126 + _list = NULL;
1.127 + }
1.128 + _index = 0;
1.129 + }
1.130 +
1.131 + // Accessors.
1.132 + jobject get_initiatingLoader() {
1.133 + return _initiatingLoader;
1.134 + }
1.135 +
1.136 + int get_count() {
1.137 + return _count;
1.138 + }
1.139 +
1.140 + void set_count(int value) {
1.141 + _count = value;
1.142 + }
1.143 +
1.144 + Handle* get_list() {
1.145 + return _list;
1.146 + }
1.147 +
1.148 + void set_list(Handle* value) {
1.149 + _list = value;
1.150 + }
1.151 +
1.152 + int get_index() {
1.153 + return _index;
1.154 + }
1.155 +
1.156 + void set_index(int value) {
1.157 + _index = value;
1.158 + }
1.159 +
1.160 + Handle get_element(int index) {
1.161 + if ((_list != NULL) && (index < _count)) {
1.162 + return _list[index];
1.163 + } else {
1.164 + assert(false, "empty get_element");
1.165 + return Handle();
1.166 + }
1.167 + }
1.168 +
1.169 + void set_element(int index, Handle value) {
1.170 + if ((_list != NULL) && (index < _count)) {
1.171 + _list[index] = value;
1.172 + } else {
1.173 + assert(false, "bad set_element");
1.174 + }
1.175 + }
1.176 +
1.177 + // Other predicates
1.178 + bool available() {
1.179 + return (_list != NULL);
1.180 + }
1.181 +
1.182 +#ifdef ASSERT
1.183 + // For debugging.
1.184 + void check(int limit) {
1.185 + for (int i = 0; i < limit; i += 1) {
1.186 + assert(Universe::heap()->is_in(get_element(i)()), "check fails");
1.187 + }
1.188 + }
1.189 +#endif
1.190 +
1.191 + // Public methods that get called within the scope of the closure
1.192 + void allocate() {
1.193 + _list = NEW_C_HEAP_ARRAY(Handle, _count, mtInternal);
1.194 + assert(_list != NULL, "Out of memory");
1.195 + if (_list == NULL) {
1.196 + _count = 0;
1.197 + }
1.198 + }
1.199 +
1.200 + void extract(JvmtiEnv *env, jclass* result) {
1.201 + for (int index = 0; index < _count; index += 1) {
1.202 + result[index] = (jclass) env->jni_reference(get_element(index));
1.203 + }
1.204 + }
1.205 +
1.206 + static void increment_with_loader(Klass* k, ClassLoaderData* loader_data) {
1.207 + JvmtiGetLoadedClassesClosure* that = JvmtiGetLoadedClassesClosure::get_this();
1.208 + oop class_loader = loader_data->class_loader();
1.209 + if (class_loader == JNIHandles::resolve(that->get_initiatingLoader())) {
1.210 + for (Klass* l = k; l != NULL; l = l->array_klass_or_null()) {
1.211 + that->set_count(that->get_count() + 1);
1.212 + }
1.213 + }
1.214 + }
1.215 +
1.216 + static void prim_array_increment_with_loader(Klass* array, ClassLoaderData* loader_data) {
1.217 + JvmtiGetLoadedClassesClosure* that = JvmtiGetLoadedClassesClosure::get_this();
1.218 + oop class_loader = loader_data->class_loader();
1.219 + if (class_loader == JNIHandles::resolve(that->get_initiatingLoader())) {
1.220 + that->set_count(that->get_count() + 1);
1.221 + }
1.222 + }
1.223 +
1.224 + static void add_with_loader(Klass* k, ClassLoaderData* loader_data) {
1.225 + JvmtiGetLoadedClassesClosure* that = JvmtiGetLoadedClassesClosure::get_this();
1.226 + if (that->available()) {
1.227 + oop class_loader = loader_data->class_loader();
1.228 + if (class_loader == JNIHandles::resolve(that->get_initiatingLoader())) {
1.229 + for (Klass* l = k; l != NULL; l = l->array_klass_or_null()) {
1.230 + oop mirror = l->java_mirror();
1.231 + that->set_element(that->get_index(), mirror);
1.232 + that->set_index(that->get_index() + 1);
1.233 + }
1.234 + }
1.235 + }
1.236 + }
1.237 +
1.238 + // increment the count for the given basic type array class (and any
1.239 + // multi-dimensional arrays). For example, for [B we check for
1.240 + // [[B, [[[B, .. and the count is incremented for each one that exists.
1.241 + static void increment_for_basic_type_arrays(Klass* k) {
1.242 + JvmtiGetLoadedClassesClosure* that = JvmtiGetLoadedClassesClosure::get_this();
1.243 + assert(that != NULL, "no JvmtiGetLoadedClassesClosure");
1.244 + for (Klass* l = k; l != NULL; l = l->array_klass_or_null()) {
1.245 + that->set_count(that->get_count() + 1);
1.246 + }
1.247 + }
1.248 +
1.249 + // add the basic type array class and its multi-dimensional array classes to the list
1.250 + static void add_for_basic_type_arrays(Klass* k) {
1.251 + JvmtiGetLoadedClassesClosure* that = JvmtiGetLoadedClassesClosure::get_this();
1.252 + assert(that != NULL, "no JvmtiGetLoadedClassesClosure");
1.253 + assert(that->available(), "no list");
1.254 + for (Klass* l = k; l != NULL; l = l->array_klass_or_null()) {
1.255 + oop mirror = l->java_mirror();
1.256 + that->set_element(that->get_index(), mirror);
1.257 + that->set_index(that->get_index() + 1);
1.258 + }
1.259 + }
1.260 +};
1.261 +
1.262 +
1.263 +jvmtiError
1.264 +JvmtiGetLoadedClasses::getLoadedClasses(JvmtiEnv *env, jint* classCountPtr, jclass** classesPtr) {
1.265 +
1.266 + LoadedClassesClosure closure(env);
1.267 + {
1.268 + // To get a consistent list of classes we need MultiArray_lock to ensure
1.269 + // array classes aren't created.
1.270 + MutexLocker ma(MultiArray_lock);
1.271 +
1.272 + // Iterate through all classes in ClassLoaderDataGraph
1.273 + // and collect them using the LoadedClassesClosure
1.274 + ClassLoaderDataGraph::loaded_classes_do(&closure);
1.275 + }
1.276 +
1.277 + // Return results by extracting the collected contents into a list
1.278 + // allocated via JvmtiEnv
1.279 + jclass* result_list;
1.280 + jvmtiError error = env->Allocate(closure.get_count() * sizeof(jclass),
1.281 + (unsigned char**)&result_list);
1.282 +
1.283 + if (error == JVMTI_ERROR_NONE) {
1.284 + int count = closure.extract(result_list);
1.285 + *classCountPtr = count;
1.286 + *classesPtr = result_list;
1.287 + }
1.288 + return error;
1.289 +}
1.290 +
1.291 +jvmtiError
1.292 +JvmtiGetLoadedClasses::getClassLoaderClasses(JvmtiEnv *env, jobject initiatingLoader,
1.293 + jint* classCountPtr, jclass** classesPtr) {
1.294 + // Since SystemDictionary::classes_do only takes a function pointer
1.295 + // and doesn't call back with a closure data pointer,
1.296 + // we can only pass static methods.
1.297 + JvmtiGetLoadedClassesClosure closure(initiatingLoader);
1.298 + {
1.299 + // To get a consistent list of classes we need MultiArray_lock to ensure
1.300 + // array classes aren't created, and SystemDictionary_lock to ensure that
1.301 + // classes aren't added to the system dictionary,
1.302 + MutexLocker ma(MultiArray_lock);
1.303 + MutexLocker sd(SystemDictionary_lock);
1.304 + // First, count the classes in the system dictionary which have this loader recorded
1.305 + // as an initiating loader. For basic type arrays this information is not recorded
1.306 + // so GetClassLoaderClasses will return all of the basic type arrays. This is okay
1.307 + // because the defining loader for basic type arrays is always the boot class loader
1.308 + // and these classes are "visible" to all loaders.
1.309 + SystemDictionary::classes_do(&JvmtiGetLoadedClassesClosure::increment_with_loader);
1.310 + Universe::basic_type_classes_do(&JvmtiGetLoadedClassesClosure::increment_for_basic_type_arrays);
1.311 + // Next, fill in the classes
1.312 + closure.allocate();
1.313 + SystemDictionary::classes_do(&JvmtiGetLoadedClassesClosure::add_with_loader);
1.314 + Universe::basic_type_classes_do(&JvmtiGetLoadedClassesClosure::add_for_basic_type_arrays);
1.315 + // Drop the SystemDictionary_lock, so the results could be wrong from here,
1.316 + // but we still have a snapshot.
1.317 + }
1.318 + // Post results
1.319 + jclass* result_list;
1.320 + jvmtiError err = env->Allocate(closure.get_count() * sizeof(jclass),
1.321 + (unsigned char**)&result_list);
1.322 + if (err != JVMTI_ERROR_NONE) {
1.323 + return err;
1.324 + }
1.325 + closure.extract(env, result_list);
1.326 + *classCountPtr = closure.get_count();
1.327 + *classesPtr = result_list;
1.328 + return JVMTI_ERROR_NONE;
1.329 +}
