1 /*
2 * Copyright (c) 2014, 2020, 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 #include "precompiled.hpp"
26 #include "aot/aotLoader.hpp"
27 #include "classfile/classLoaderDataGraph.hpp"
28 #include "classfile/stringTable.hpp"
29 #include "gc/shared/oopStorage.inline.hpp"
30 #include "gc/shared/oopStorageSet.hpp"
31 #include "gc/shared/strongRootsScope.hpp"
32 #include "jfr/leakprofiler/utilities/unifiedOopRef.inline.hpp"
33 #include "jfr/leakprofiler/checkpoint/rootResolver.hpp"
34 #include "jfr/utilities/jfrThreadIterator.hpp"
35 #include "memory/iterator.hpp"
36 #include "memory/universe.hpp"
37 #include "oops/klass.hpp"
38 #include "oops/oop.hpp"
39 #include "prims/jvmtiThreadState.hpp"
40 #include "runtime/frame.inline.hpp"
41 #include "runtime/mutexLocker.hpp"
42 #include "runtime/vframe_hp.hpp"
43 #include "services/management.hpp"
44 #include "utilities/growableArray.hpp"
45
46 class ReferenceLocateClosure : public OopClosure {
47 protected:
48 RootCallback& _callback;
49 RootCallbackInfo _info;
50 bool _complete;
51
52 void do_oop_shared(UnifiedOopRef ref);
53
54 public:
55 ReferenceLocateClosure(RootCallback& callback,
56 OldObjectRoot::System system,
57 OldObjectRoot::Type type,
58 const void* context) : _callback(callback),
59 _info(),
60 _complete(false) {
61 _info._high = NULL;
62 _info._low = NULL;
63 _info._system = system;
64 _info._type = type;
65 _info._context = context;
66 }
67
68 virtual void do_oop(oop* ref);
69 virtual void do_oop(narrowOop* ref);
70
71 bool complete() const {
72 return _complete;
73 }
74 };
75
76 void ReferenceLocateClosure::do_oop_shared(UnifiedOopRef ref) {
77 assert(!ref.is_null(), "invariant");
78 if (!_complete) {
79 _info._high = ref.addr<address>();
80 _complete = _callback.process(_info);
81 }
82 }
83
84 void ReferenceLocateClosure::do_oop(oop* ref) {
85 do_oop_shared(UnifiedOopRef::encode_in_native(ref));
86 }
87
88 void ReferenceLocateClosure::do_oop(narrowOop* ref) {
89 do_oop_shared(UnifiedOopRef::encode_in_native(ref));
90 }
91
92 class ReferenceToRootClosure : public StackObj {
93 private:
94 RootCallback& _callback;
95 RootCallbackInfo _info;
96 bool _complete;
97
98 bool do_cldg_roots();
99 bool do_object_synchronizer_roots();
100 bool do_universe_roots();
101 bool do_oop_storage_roots();
102 bool do_jvmti_roots();
103 bool do_management_roots();
104 bool do_string_table_roots();
105 bool do_aot_loader_roots();
106
107 bool do_roots();
108
109 public:
110 ReferenceToRootClosure(RootCallback& callback) : _callback(callback),
111 _info(),
112 _complete(false) {
113 _info._high = NULL;
114 _info._low = NULL;
115 _info._context = NULL;
116 _info._system = OldObjectRoot::_system_undetermined;
117 _info._type = OldObjectRoot::_type_undetermined;
118
119 assert_locked_or_safepoint(Threads_lock);
120 do_roots();
121 }
122
123 bool complete() const {
124 return _complete;
125 }
126 };
127
128 bool ReferenceToRootClosure::do_cldg_roots() {
129 assert(!complete(), "invariant");
130 ReferenceLocateClosure rlc(_callback, OldObjectRoot::_class_loader_data, OldObjectRoot::_type_undetermined, NULL);
131 CLDToOopClosure cldt_closure(&rlc, ClassLoaderData::_claim_none);
132 ClassLoaderDataGraph::always_strong_cld_do(&cldt_closure);
133 return rlc.complete();
134 }
135
136 bool ReferenceToRootClosure::do_object_synchronizer_roots() {
137 assert(!complete(), "invariant");
138 ReferenceLocateClosure rlc(_callback, OldObjectRoot::_object_synchronizer, OldObjectRoot::_type_undetermined, NULL);
139 ObjectSynchronizer::oops_do(&rlc);
140 return rlc.complete();
141 }
142
143 bool ReferenceToRootClosure::do_universe_roots() {
144 assert(!complete(), "invariant");
145 ReferenceLocateClosure rlc(_callback, OldObjectRoot::_universe, OldObjectRoot::_type_undetermined, NULL);
146 Universe::oops_do(&rlc);
147 return rlc.complete();
148 }
149
150 bool ReferenceToRootClosure::do_oop_storage_roots() {
151 int i = 0;
152 for (OopStorageSet::Iterator it = OopStorageSet::strong_iterator(); !it.is_end(); ++it, ++i) {
153 assert(!complete(), "invariant");
154 OopStorage* oop_storage = *it;
155 OldObjectRoot::Type type = oop_storage == OopStorageSet::jni_global() ?
156 OldObjectRoot::_global_jni_handle :
157 OldObjectRoot::_global_oop_handle;
158 OldObjectRoot::System system = OldObjectRoot::System(OldObjectRoot::_strong_oop_storage_set_first + i);
159 ReferenceLocateClosure rlc(_callback, system, type, NULL);
160 oop_storage->oops_do(&rlc);
161 if (rlc.complete()) {
162 return true;
163 }
164 }
165 return false;
166 }
167
168 bool ReferenceToRootClosure::do_jvmti_roots() {
169 assert(!complete(), "invariant");
170 ReferenceLocateClosure rlc(_callback, OldObjectRoot::_jvmti, OldObjectRoot::_global_jni_handle, NULL);
171 JvmtiExport::oops_do(&rlc);
172 return rlc.complete();
173 }
174
175 bool ReferenceToRootClosure::do_management_roots() {
176 assert(!complete(), "invariant");
177 ReferenceLocateClosure rlc(_callback, OldObjectRoot::_management, OldObjectRoot::_type_undetermined, NULL);
178 Management::oops_do(&rlc);
179 return rlc.complete();
180 }
181
182 bool ReferenceToRootClosure::do_aot_loader_roots() {
183 assert(!complete(), "invariant");
184 ReferenceLocateClosure rcl(_callback, OldObjectRoot::_aot, OldObjectRoot::_type_undetermined, NULL);
185 AOTLoader::oops_do(&rcl);
186 return rcl.complete();
187 }
188
189 bool ReferenceToRootClosure::do_roots() {
190 assert(!complete(), "invariant");
191 assert(OldObjectRoot::_system_undetermined == _info._system, "invariant");
192 assert(OldObjectRoot::_type_undetermined == _info._type, "invariant");
193
194 if (do_cldg_roots()) {
195 _complete = true;
196 return true;
197 }
198
199 if (do_object_synchronizer_roots()) {
200 _complete = true;
201 return true;
202 }
203
204 if (do_universe_roots()) {
205 _complete = true;
206 return true;
207 }
208
209 if (do_oop_storage_roots()) {
210 _complete = true;
211 return true;
212 }
213
214 if (do_jvmti_roots()) {
215 _complete = true;
216 return true;
217 }
218
219 if (do_management_roots()) {
220 _complete = true;
221 return true;
222 }
223
224 if (do_aot_loader_roots()) {
225 _complete = true;
226 return true;
227 }
228
229 return false;
230 }
231
232 class ReferenceToThreadRootClosure : public StackObj {
233 private:
234 RootCallback& _callback;
235 bool _complete;
236
237 bool do_java_threads_oops(JavaThread* jt);
238 bool do_thread_roots(JavaThread* jt);
239 bool do_thread_stack_fast(JavaThread* jt);
240 bool do_thread_stack_detailed(JavaThread* jt);
241 bool do_thread_jni_handles(JavaThread* jt);
242 bool do_thread_handle_area(JavaThread* jt);
243
244 public:
245 ReferenceToThreadRootClosure(RootCallback& callback) :_callback(callback), _complete(false) {
246 assert_locked_or_safepoint(Threads_lock);
247 JfrJavaThreadIterator iter;
248 while (iter.has_next()) {
249 if (do_thread_roots(iter.next())) {
250 return;
251 }
252 }
253 }
254
255 bool complete() const {
256 return _complete;
257 }
258 };
259
260 bool ReferenceToThreadRootClosure::do_thread_handle_area(JavaThread* jt) {
261 assert(jt != NULL, "invariant");
262 assert(!complete(), "invariant");
263 ReferenceLocateClosure rcl(_callback, OldObjectRoot::_threads, OldObjectRoot::_handle_area, jt);
264 jt->handle_area()->oops_do(&rcl);
265 return rcl.complete();
266 }
267
268 bool ReferenceToThreadRootClosure::do_thread_jni_handles(JavaThread* jt) {
269 assert(jt != NULL, "invariant");
270 assert(!complete(), "invariant");
271
272 ReferenceLocateClosure rcl(_callback, OldObjectRoot::_threads, OldObjectRoot::_local_jni_handle, jt);
273 jt->active_handles()->oops_do(&rcl);
274 return rcl.complete();
275 }
276
277 bool ReferenceToThreadRootClosure::do_thread_stack_fast(JavaThread* jt) {
278 assert(jt != NULL, "invariant");
279 assert(!complete(), "invariant");
280
281 if (_callback.entries() == 0) {
282 _complete = true;
283 return true;
284 }
285
286 RootCallbackInfo info;
287 info._high = NULL;
288 info._low = NULL;
289 info._context = jt;
290 info._system = OldObjectRoot::_threads;
291 info._type = OldObjectRoot::_stack_variable;
292
293 for (int i = 0; i < _callback.entries(); ++i) {
294 const address adr = _callback.at(i).addr<address>();
295 if (jt->is_in_usable_stack(adr)) {
296 info._high = adr;
297 _complete = _callback.process(info);
298 if (_complete) {
299 return true;
300 }
301 }
302 }
303 assert(!complete(), "invariant");
304 return false;
305 }
306
307 bool ReferenceToThreadRootClosure::do_thread_stack_detailed(JavaThread* jt) {
308 assert(jt != NULL, "invariant");
309 assert(!complete(), "invariant");
310
311 ReferenceLocateClosure rcl(_callback, OldObjectRoot::_threads, OldObjectRoot::_stack_variable, jt);
312
313 if (jt->has_last_Java_frame()) {
314 // traverse the registered growable array gc_array
315 // can't do this as it is not reachable from outside
316
317 // Traverse the monitor chunks
318 MonitorChunk* chunk = jt->monitor_chunks();
319 for (; chunk != NULL; chunk = chunk->next()) {
320 chunk->oops_do(&rcl);
321 }
322
323 if (rcl.complete()) {
324 return true;
325 }
326
327 // Traverse the execution stack
328 for (StackFrameStream fst(jt); !fst.is_done(); fst.next()) {
329 fst.current()->oops_do(&rcl, NULL, fst.register_map());
330 }
331
332 } // last java frame
333
334 if (rcl.complete()) {
335 return true;
336 }
337
338 GrowableArray<jvmtiDeferredLocalVariableSet*>* const list = JvmtiDeferredUpdates::deferred_locals(jt);
339 if (list != NULL) {
340 for (int i = 0; i < list->length(); i++) {
341 list->at(i)->oops_do(&rcl);
342 }
343 }
344
345 if (rcl.complete()) {
346 return true;
347 }
348
349 // Traverse instance variables at the end since the GC may be moving things
350 // around using this function
351 /*
352 * // can't reach these oop* from the outside
353 f->do_oop((oop*) &_threadObj);
354 f->do_oop((oop*) &_vm_result);
355 f->do_oop((oop*) &_exception_oop);
356 f->do_oop((oop*) &_pending_async_exception);
357 */
358
359 JvmtiThreadState* const jvmti_thread_state = jt->jvmti_thread_state();
360 if (jvmti_thread_state != NULL) {
361 jvmti_thread_state->oops_do(&rcl, NULL);
362 }
363
364 return rcl.complete();
365 }
366
367 bool ReferenceToThreadRootClosure::do_java_threads_oops(JavaThread* jt) {
368 assert(jt != NULL, "invariant");
369 assert(!complete(), "invariant");
370
371 ReferenceLocateClosure rcl(_callback, OldObjectRoot::_threads, OldObjectRoot::_global_jni_handle, jt);
372 jt->oops_do(&rcl, NULL);
373 return rcl.complete();
374 }
375
376 bool ReferenceToThreadRootClosure::do_thread_roots(JavaThread* jt) {
377 assert(jt != NULL, "invariant");
378
379 if (do_thread_stack_fast(jt)) {
380 _complete = true;
381 return true;
382 }
383
384 if (do_thread_jni_handles(jt)) {
385 _complete = true;
386 return true;
387 }
388
389 if (do_thread_handle_area(jt)) {
390 _complete = true;
391 return true;
392 }
393
394 if (do_thread_stack_detailed(jt)) {
395 _complete = true;
396 return true;
397 }
398
399 return false;
400 }
401
402 class RootResolverMarkScope : public MarkScope {
403 };
404
405 void RootResolver::resolve(RootCallback& callback) {
406 RootResolverMarkScope mark_scope;
407
408 // thread local roots
409 ReferenceToThreadRootClosure rtrc(callback);
410 if (rtrc.complete()) {
411 return;
412 }
413 // system global roots
414 ReferenceToRootClosure rrc(callback);
415 }