1 /*
2 * Copyright (c) 2003, 2005, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25
26 # include "incls/_precompiled.incl"
27 # include "incls/_jvmtiGetLoadedClasses.cpp.incl"
28
29
30 // The closure for GetLoadedClasses and GetClassLoaderClasses
31 class JvmtiGetLoadedClassesClosure : public StackObj {
32 // Since the SystemDictionary::classes_do callback
33 // doesn't pass a closureData pointer,
34 // we use a thread-local slot to hold a pointer to
35 // a stack allocated instance of this structure.
36 private:
37 jobject _initiatingLoader;
38 int _count;
39 Handle* _list;
40 int _index;
41
42 private:
43 // Getting and setting the thread local pointer
44 static JvmtiGetLoadedClassesClosure* get_this() {
45 JvmtiGetLoadedClassesClosure* result = NULL;
46 JavaThread* thread = JavaThread::current();
47 result = thread->get_jvmti_get_loaded_classes_closure();
48 return result;
49 }
50 static void set_this(JvmtiGetLoadedClassesClosure* that) {
51 JavaThread* thread = JavaThread::current();
52 thread->set_jvmti_get_loaded_classes_closure(that);
53 }
54
55 public:
56 // Constructor/Destructor
57 JvmtiGetLoadedClassesClosure() {
58 JvmtiGetLoadedClassesClosure* that = get_this();
59 assert(that == NULL, "JvmtiGetLoadedClassesClosure in use");
60 _initiatingLoader = NULL;
61 _count = 0;
62 _list = NULL;
63 _index = 0;
64 set_this(this);
65 }
66
67 JvmtiGetLoadedClassesClosure(jobject initiatingLoader) {
68 JvmtiGetLoadedClassesClosure* that = get_this();
69 assert(that == NULL, "JvmtiGetLoadedClassesClosure in use");
70 _initiatingLoader = initiatingLoader;
71 _count = 0;
72 _list = NULL;
73 _index = 0;
74 set_this(this);
75 }
76
77 ~JvmtiGetLoadedClassesClosure() {
78 JvmtiGetLoadedClassesClosure* that = get_this();
79 assert(that != NULL, "JvmtiGetLoadedClassesClosure not found");
80 set_this(NULL);
81 _initiatingLoader = NULL;
82 _count = 0;
83 if (_list != NULL) {
84 FreeHeap(_list);
85 _list = NULL;
86 }
87 _index = 0;
88 }
89
90 // Accessors.
91 jobject get_initiatingLoader() {
92 return _initiatingLoader;
93 }
94
95 int get_count() {
96 return _count;
97 }
98
99 void set_count(int value) {
100 _count = value;
101 }
102
103 Handle* get_list() {
104 return _list;
105 }
106
107 void set_list(Handle* value) {
108 _list = value;
109 }
110
111 int get_index() {
112 return _index;
113 }
114
115 void set_index(int value) {
116 _index = value;
117 }
118
119 Handle get_element(int index) {
120 if ((_list != NULL) && (index < _count)) {
121 return _list[index];
122 } else {
123 assert(false, "empty get_element");
124 return Handle();
125 }
126 }
127
128 void set_element(int index, Handle value) {
129 if ((_list != NULL) && (index < _count)) {
130 _list[index] = value;
131 } else {
132 assert(false, "bad set_element");
133 }
134 }
135
136 // Other predicates
137 bool available() {
138 return (_list != NULL);
139 }
140
141 #ifdef ASSERT
142 // For debugging.
143 void check(int limit) {
144 for (int i = 0; i < limit; i += 1) {
145 assert(Universe::heap()->is_in(get_element(i)()), "check fails");
146 }
147 }
148 #endif
149
150 // Public methods that get called within the scope of the closure
151 void allocate() {
152 _list = NEW_C_HEAP_ARRAY(Handle, _count);
153 assert(_list != NULL, "Out of memory");
154 if (_list == NULL) {
155 _count = 0;
156 }
157 }
158
159 void extract(JvmtiEnv *env, jclass* result) {
160 for (int index = 0; index < _count; index += 1) {
161 result[index] = (jclass) env->jni_reference(get_element(index));
162 }
163 }
164
165 // Finally, the static methods that are the callbacks
166 static void increment(klassOop k) {
167 JvmtiGetLoadedClassesClosure* that = JvmtiGetLoadedClassesClosure::get_this();
168 if (that->get_initiatingLoader() == NULL) {
169 for (klassOop l = k; l != NULL; l = Klass::cast(l)->array_klass_or_null()) {
170 that->set_count(that->get_count() + 1);
171 }
172 } else if (k != NULL) {
173 // if initiating loader not null, just include the instance with 1 dimension
174 that->set_count(that->get_count() + 1);
175 }
176 }
177
178 static void increment_with_loader(klassOop k, oop loader) {
179 JvmtiGetLoadedClassesClosure* that = JvmtiGetLoadedClassesClosure::get_this();
180 if (loader == JNIHandles::resolve(that->get_initiatingLoader())) {
181 for (klassOop l = k; l != NULL; l = Klass::cast(l)->array_klass_or_null()) {
182 that->set_count(that->get_count() + 1);
183 }
184 }
185 }
186
187 static void prim_array_increment_with_loader(klassOop array, oop loader) {
188 JvmtiGetLoadedClassesClosure* that = JvmtiGetLoadedClassesClosure::get_this();
189 if (loader == JNIHandles::resolve(that->get_initiatingLoader())) {
190 that->set_count(that->get_count() + 1);
191 }
192 }
193
194 static void add(klassOop k) {
195 JvmtiGetLoadedClassesClosure* that = JvmtiGetLoadedClassesClosure::get_this();
196 if (that->available()) {
197 if (that->get_initiatingLoader() == NULL) {
198 for (klassOop l = k; l != NULL; l = Klass::cast(l)->array_klass_or_null()) {
199 oop mirror = Klass::cast(l)->java_mirror();
200 that->set_element(that->get_index(), mirror);
201 that->set_index(that->get_index() + 1);
202 }
203 } else if (k != NULL) {
204 // if initiating loader not null, just include the instance with 1 dimension
205 oop mirror = Klass::cast(k)->java_mirror();
206 that->set_element(that->get_index(), mirror);
207 that->set_index(that->get_index() + 1);
208 }
209 }
210 }
211
212 static void add_with_loader(klassOop k, oop loader) {
213 JvmtiGetLoadedClassesClosure* that = JvmtiGetLoadedClassesClosure::get_this();
214 if (that->available()) {
215 if (loader == JNIHandles::resolve(that->get_initiatingLoader())) {
216 for (klassOop l = k; l != NULL; l = Klass::cast(l)->array_klass_or_null()) {
217 oop mirror = Klass::cast(l)->java_mirror();
218 that->set_element(that->get_index(), mirror);
219 that->set_index(that->get_index() + 1);
220 }
221 }
222 }
223 }
224
225 // increment the count for the given basic type array class (and any
226 // multi-dimensional arrays). For example, for [B we check for
227 // [[B, [[[B, .. and the count is incremented for each one that exists.
228 static void increment_for_basic_type_arrays(klassOop k) {
229 JvmtiGetLoadedClassesClosure* that = JvmtiGetLoadedClassesClosure::get_this();
230 assert(that != NULL, "no JvmtiGetLoadedClassesClosure");
231 for (klassOop l = k; l != NULL; l = Klass::cast(l)->array_klass_or_null()) {
232 that->set_count(that->get_count() + 1);
233 }
234 }
235
236 // add the basic type array class and its multi-dimensional array classes to the list
237 static void add_for_basic_type_arrays(klassOop k) {
238 JvmtiGetLoadedClassesClosure* that = JvmtiGetLoadedClassesClosure::get_this();
239 assert(that != NULL, "no JvmtiGetLoadedClassesClosure");
240 assert(that->available(), "no list");
241 for (klassOop l = k; l != NULL; l = Klass::cast(l)->array_klass_or_null()) {
242 oop mirror = Klass::cast(l)->java_mirror();
243 that->set_element(that->get_index(), mirror);
244 that->set_index(that->get_index() + 1);
245 }
246 }
247 };
248
249
250 jvmtiError
251 JvmtiGetLoadedClasses::getLoadedClasses(JvmtiEnv *env, jint* classCountPtr, jclass** classesPtr) {
252 // Since SystemDictionary::classes_do only takes a function pointer
253 // and doesn't call back with a closure data pointer,
254 // we can only pass static methods.
255
256 JvmtiGetLoadedClassesClosure closure;
257 {
258 // To get a consistent list of classes we need MultiArray_lock to ensure
259 // array classes aren't created, and SystemDictionary_lock to ensure that
260 // classes aren't added to the system dictionary,
261 MutexLocker ma(MultiArray_lock);
262 MutexLocker sd(SystemDictionary_lock);
263
264 // First, count the classes
265 SystemDictionary::classes_do(&JvmtiGetLoadedClassesClosure::increment);
266 Universe::basic_type_classes_do(&JvmtiGetLoadedClassesClosure::increment);
267 // Next, fill in the classes
268 closure.allocate();
269 SystemDictionary::classes_do(&JvmtiGetLoadedClassesClosure::add);
270 Universe::basic_type_classes_do(&JvmtiGetLoadedClassesClosure::add);
271 // Drop the SystemDictionary_lock, so the results could be wrong from here,
272 // but we still have a snapshot.
273 }
274 // Post results
275 jclass* result_list;
276 jvmtiError err = env->Allocate(closure.get_count() * sizeof(jclass),
277 (unsigned char**)&result_list);
278 if (err != JVMTI_ERROR_NONE) {
279 return err;
280 }
281 closure.extract(env, result_list);
282 *classCountPtr = closure.get_count();
283 *classesPtr = result_list;
284 return JVMTI_ERROR_NONE;
285 }
286
287 jvmtiError
288 JvmtiGetLoadedClasses::getClassLoaderClasses(JvmtiEnv *env, jobject initiatingLoader,
289 jint* classCountPtr, jclass** classesPtr) {
290 // Since SystemDictionary::classes_do only takes a function pointer
291 // and doesn't call back with a closure data pointer,
292 // we can only pass static methods.
293 JvmtiGetLoadedClassesClosure closure(initiatingLoader);
294 {
295 // To get a consistent list of classes we need MultiArray_lock to ensure
296 // array classes aren't created, and SystemDictionary_lock to ensure that
297 // classes aren't added to the system dictionary,
298 MutexLocker ma(MultiArray_lock);
299 MutexLocker sd(SystemDictionary_lock);
300 // First, count the classes in the system dictionary which have this loader recorded
301 // as an initiating loader. For basic type arrays this information is not recorded
302 // so GetClassLoaderClasses will return all of the basic type arrays. This is okay
303 // because the defining loader for basic type arrays is always the boot class loader
304 // and these classes are "visible" to all loaders.
305 SystemDictionary::classes_do(&JvmtiGetLoadedClassesClosure::increment_with_loader);
306 Universe::basic_type_classes_do(&JvmtiGetLoadedClassesClosure::increment_for_basic_type_arrays);
307 // Next, fill in the classes
308 closure.allocate();
309 SystemDictionary::classes_do(&JvmtiGetLoadedClassesClosure::add_with_loader);
310 Universe::basic_type_classes_do(&JvmtiGetLoadedClassesClosure::add_for_basic_type_arrays);
311 // Drop the SystemDictionary_lock, so the results could be wrong from here,
312 // but we still have a snapshot.
313 }
314 // Post results
315 jclass* result_list;
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;
325 }