1 /*
2 * Copyright (c) 2003, 2009, 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 # include "incls/_precompiled.incl"
25 # include "incls/_jvmtiEnvBase.cpp.incl"
26
27
28 ///////////////////////////////////////////////////////////////
29 //
30 // JvmtiEnvBase
31 //
32
33 JvmtiEnvBase* JvmtiEnvBase::_head_environment = NULL;
34
35 bool JvmtiEnvBase::_globally_initialized = false;
36 volatile bool JvmtiEnvBase::_needs_clean_up = false;
37
38 jvmtiPhase JvmtiEnvBase::_phase = JVMTI_PHASE_PRIMORDIAL;
39
40 volatile int JvmtiEnvBase::_dying_thread_env_iteration_count = 0;
41
42 extern jvmtiInterface_1_ jvmti_Interface;
43 extern jvmtiInterface_1_ jvmtiTrace_Interface;
44
45
46 // perform initializations that must occur before any JVMTI environments
47 // are released but which should only be initialized once (no matter
48 // how many environments are created).
49 void
50 JvmtiEnvBase::globally_initialize() {
51 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
52 assert(_globally_initialized == false, "bad call");
53
54 JvmtiManageCapabilities::initialize();
55
56 #ifndef JVMTI_KERNEL
57 // register extension functions and events
58 JvmtiExtensions::register_extensions();
59 #endif // !JVMTI_KERNEL
60
61 #ifdef JVMTI_TRACE
62 JvmtiTrace::initialize();
63 #endif
64
65 _globally_initialized = true;
66 }
67
68
69 void
70 JvmtiEnvBase::initialize() {
71 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
72
73 // Add this environment to the end of the environment list (order is important)
74 {
75 // This block of code must not contain any safepoints, as list deallocation
76 // (which occurs at a safepoint) cannot occur simultaneously with this list
77 // addition. Note: No_Safepoint_Verifier cannot, currently, be used before
78 // threads exist.
79 JvmtiEnvIterator it;
80 JvmtiEnvBase *previous_env = NULL;
81 for (JvmtiEnvBase* env = it.first(); env != NULL; env = it.next(env)) {
82 previous_env = env;
83 }
84 if (previous_env == NULL) {
85 _head_environment = this;
86 } else {
87 previous_env->set_next_environment(this);
88 }
89 }
90
91 if (_globally_initialized == false) {
92 globally_initialize();
93 }
94 }
95
96
97 bool
98 JvmtiEnvBase::is_valid() {
99 jint value = 0;
100
101 // This object might not be a JvmtiEnvBase so we can't assume
102 // the _magic field is properly aligned. Get the value in a safe
103 // way and then check against JVMTI_MAGIC.
104
105 switch (sizeof(_magic)) {
106 case 2:
107 value = Bytes::get_native_u2((address)&_magic);
108 break;
109
110 case 4:
111 value = Bytes::get_native_u4((address)&_magic);
112 break;
113
114 case 8:
115 value = Bytes::get_native_u8((address)&_magic);
116 break;
117
118 default:
119 guarantee(false, "_magic field is an unexpected size");
120 }
121
122 return value == JVMTI_MAGIC;
123 }
124
125
126 bool
127 JvmtiEnvBase::use_version_1_0_semantics() {
128 int major, minor, micro;
129
130 JvmtiExport::decode_version_values(_version, &major, &minor, µ);
131 return major == 1 && minor == 0; // micro version doesn't matter here
132 }
133
134
135 bool
136 JvmtiEnvBase::use_version_1_1_semantics() {
137 int major, minor, micro;
138
139 JvmtiExport::decode_version_values(_version, &major, &minor, µ);
140 return major == 1 && minor == 1; // micro version doesn't matter here
141 }
142
143
144 JvmtiEnvBase::JvmtiEnvBase(jint version) : _env_event_enable() {
145 _version = version;
146 _env_local_storage = NULL;
147 _tag_map = NULL;
148 _native_method_prefix_count = 0;
149 _native_method_prefixes = NULL;
150 _next = NULL;
151 _class_file_load_hook_ever_enabled = false;
152
153 // Moot since ClassFileLoadHook not yet enabled.
154 // But "true" will give a more predictable ClassFileLoadHook behavior
155 // for environment creation during ClassFileLoadHook.
156 _is_retransformable = true;
157
158 // all callbacks initially NULL
159 memset(&_event_callbacks,0,sizeof(jvmtiEventCallbacks));
160
161 // all capabilities initially off
162 memset(&_current_capabilities, 0, sizeof(_current_capabilities));
163
164 // all prohibited capabilities initially off
165 memset(&_prohibited_capabilities, 0, sizeof(_prohibited_capabilities));
166
167 _magic = JVMTI_MAGIC;
168
169 JvmtiEventController::env_initialize((JvmtiEnv*)this);
170
171 #ifdef JVMTI_TRACE
172 _jvmti_external.functions = TraceJVMTI != NULL ? &jvmtiTrace_Interface : &jvmti_Interface;
173 #else
174 _jvmti_external.functions = &jvmti_Interface;
175 #endif
176 }
177
178
179 void
180 JvmtiEnvBase::dispose() {
181
182 #ifdef JVMTI_TRACE
183 JvmtiTrace::shutdown();
184 #endif
185
186 // Dispose of event info and let the event controller call us back
187 // in a locked state (env_dispose, below)
188 JvmtiEventController::env_dispose(this);
189 }
190
191 void
192 JvmtiEnvBase::env_dispose() {
193 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
194
195 // We have been entered with all events disabled on this environment.
196 // A race to re-enable events (by setting callbacks) is prevented by
197 // checking for a valid environment when setting callbacks (while
198 // holding the JvmtiThreadState_lock).
199
200 // Mark as invalid.
201 _magic = DISPOSED_MAGIC;
202
203 // Relinquish all capabilities.
204 jvmtiCapabilities *caps = get_capabilities();
205 JvmtiManageCapabilities::relinquish_capabilities(caps, caps, caps);
206
207 // Same situation as with events (see above)
208 set_native_method_prefixes(0, NULL);
209
210 #ifndef JVMTI_KERNEL
211 JvmtiTagMap* tag_map_to_deallocate = _tag_map;
212 set_tag_map(NULL);
213 // A tag map can be big, deallocate it now
214 if (tag_map_to_deallocate != NULL) {
215 delete tag_map_to_deallocate;
216 }
217 #endif // !JVMTI_KERNEL
218
219 _needs_clean_up = true;
220 }
221
222
223 JvmtiEnvBase::~JvmtiEnvBase() {
224 assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
225
226 // There is a small window of time during which the tag map of a
227 // disposed environment could have been reallocated.
228 // Make sure it is gone.
229 #ifndef JVMTI_KERNEL
230 JvmtiTagMap* tag_map_to_deallocate = _tag_map;
231 set_tag_map(NULL);
232 // A tag map can be big, deallocate it now
233 if (tag_map_to_deallocate != NULL) {
234 delete tag_map_to_deallocate;
235 }
236 #endif // !JVMTI_KERNEL
237
238 _magic = BAD_MAGIC;
239 }
240
241
242 void
243 JvmtiEnvBase::periodic_clean_up() {
244 assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
245
246 // JvmtiEnvBase reference is saved in JvmtiEnvThreadState. So
247 // clean up JvmtiThreadState before deleting JvmtiEnv pointer.
248 JvmtiThreadState::periodic_clean_up();
249
250 // Unlink all invalid environments from the list of environments
251 // and deallocate them
252 JvmtiEnvIterator it;
253 JvmtiEnvBase* previous_env = NULL;
254 JvmtiEnvBase* env = it.first();
255 while (env != NULL) {
256 if (env->is_valid()) {
257 previous_env = env;
258 env = it.next(env);
259 } else {
260 // This one isn't valid, remove it from the list and deallocate it
261 JvmtiEnvBase* defunct_env = env;
262 env = it.next(env);
263 if (previous_env == NULL) {
264 _head_environment = env;
265 } else {
266 previous_env->set_next_environment(env);
267 }
268 delete defunct_env;
269 }
270 }
271
272 }
273
274
275 void
276 JvmtiEnvBase::check_for_periodic_clean_up() {
277 assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
278
279 class ThreadInsideIterationClosure: public ThreadClosure {
280 private:
281 bool _inside;
282 public:
283 ThreadInsideIterationClosure() : _inside(false) {};
284
285 void do_thread(Thread* thread) {
286 _inside |= thread->is_inside_jvmti_env_iteration();
287 }
288
289 bool is_inside_jvmti_env_iteration() {
290 return _inside;
291 }
292 };
293
294 if (_needs_clean_up) {
295 // Check if we are currently iterating environment,
296 // deallocation should not occur if we are
297 ThreadInsideIterationClosure tiic;
298 Threads::threads_do(&tiic);
299 if (!tiic.is_inside_jvmti_env_iteration() &&
300 !is_inside_dying_thread_env_iteration()) {
301 _needs_clean_up = false;
302 JvmtiEnvBase::periodic_clean_up();
303 }
304 }
305 }
306
307
308 void
309 JvmtiEnvBase::record_first_time_class_file_load_hook_enabled() {
310 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(),
311 "sanity check");
312
313 if (!_class_file_load_hook_ever_enabled) {
314 _class_file_load_hook_ever_enabled = true;
315
316 if (get_capabilities()->can_retransform_classes) {
317 _is_retransformable = true;
318 } else {
319 _is_retransformable = false;
320
321 // cannot add retransform capability after ClassFileLoadHook has been enabled
322 get_prohibited_capabilities()->can_retransform_classes = 1;
323 }
324 }
325 }
326
327
328 void
329 JvmtiEnvBase::record_class_file_load_hook_enabled() {
330 if (!_class_file_load_hook_ever_enabled) {
331 if (Threads::number_of_threads() == 0) {
332 record_first_time_class_file_load_hook_enabled();
333 } else {
334 MutexLocker mu(JvmtiThreadState_lock);
335 record_first_time_class_file_load_hook_enabled();
336 }
337 }
338 }
339
340
341 jvmtiError
342 JvmtiEnvBase::set_native_method_prefixes(jint prefix_count, char** prefixes) {
343 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(),
344 "sanity check");
345
346 int old_prefix_count = get_native_method_prefix_count();
347 char **old_prefixes = get_native_method_prefixes();
348
349 // allocate and install the new prefixex
350 if (prefix_count == 0 || !is_valid()) {
351 _native_method_prefix_count = 0;
352 _native_method_prefixes = NULL;
353 } else {
354 // there are prefixes, allocate an array to hold them, and fill it
355 char** new_prefixes = (char**)os::malloc((prefix_count) * sizeof(char*));
356 if (new_prefixes == NULL) {
357 return JVMTI_ERROR_OUT_OF_MEMORY;
358 }
359 for (int i = 0; i < prefix_count; i++) {
360 char* prefix = prefixes[i];
361 if (prefix == NULL) {
362 for (int j = 0; j < (i-1); j++) {
363 os::free(new_prefixes[j]);
364 }
365 os::free(new_prefixes);
366 return JVMTI_ERROR_NULL_POINTER;
367 }
368 prefix = os::strdup(prefixes[i]);
369 if (prefix == NULL) {
370 for (int j = 0; j < (i-1); j++) {
371 os::free(new_prefixes[j]);
372 }
373 os::free(new_prefixes);
374 return JVMTI_ERROR_OUT_OF_MEMORY;
375 }
376 new_prefixes[i] = prefix;
377 }
378 _native_method_prefix_count = prefix_count;
379 _native_method_prefixes = new_prefixes;
380 }
381
382 // now that we know the new prefixes have been successfully installed we can
383 // safely remove the old ones
384 if (old_prefix_count != 0) {
385 for (int i = 0; i < old_prefix_count; i++) {
386 os::free(old_prefixes[i]);
387 }
388 os::free(old_prefixes);
389 }
390
391 return JVMTI_ERROR_NONE;
392 }
393
394
395 // Collect all the prefixes which have been set in any JVM TI environments
396 // by the SetNativeMethodPrefix(es) functions. Be sure to maintain the
397 // order of environments and the order of prefixes within each environment.
398 // Return in a resource allocated array.
399 char**
400 JvmtiEnvBase::get_all_native_method_prefixes(int* count_ptr) {
401 assert(Threads::number_of_threads() == 0 ||
402 SafepointSynchronize::is_at_safepoint() ||
403 JvmtiThreadState_lock->is_locked(),
404 "sanity check");
405
406 int total_count = 0;
407 GrowableArray<char*>* prefix_array =new GrowableArray<char*>(5);
408
409 JvmtiEnvIterator it;
410 for (JvmtiEnvBase* env = it.first(); env != NULL; env = it.next(env)) {
411 int prefix_count = env->get_native_method_prefix_count();
412 char** prefixes = env->get_native_method_prefixes();
413 for (int j = 0; j < prefix_count; j++) {
414 // retrieve a prefix and so that it is safe against asynchronous changes
415 // copy it into the resource area
416 char* prefix = prefixes[j];
417 char* prefix_copy = NEW_RESOURCE_ARRAY(char, strlen(prefix)+1);
418 strcpy(prefix_copy, prefix);
419 prefix_array->at_put_grow(total_count++, prefix_copy);
420 }
421 }
422
423 char** all_prefixes = NEW_RESOURCE_ARRAY(char*, total_count);
424 char** p = all_prefixes;
425 for (int i = 0; i < total_count; ++i) {
426 *p++ = prefix_array->at(i);
427 }
428 *count_ptr = total_count;
429 return all_prefixes;
430 }
431
432 void
433 JvmtiEnvBase::set_event_callbacks(const jvmtiEventCallbacks* callbacks,
434 jint size_of_callbacks) {
435 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
436
437 size_t byte_cnt = sizeof(jvmtiEventCallbacks);
438
439 // clear in either case to be sure we got any gap between sizes
440 memset(&_event_callbacks, 0, byte_cnt);
441
442 // Now that JvmtiThreadState_lock is held, prevent a possible race condition where events
443 // are re-enabled by a call to set event callbacks where the DisposeEnvironment
444 // occurs after the boiler-plate environment check and before the lock is acquired.
445 if (callbacks != NULL && is_valid()) {
446 if (size_of_callbacks < (jint)byte_cnt) {
447 byte_cnt = size_of_callbacks;
448 }
449 memcpy(&_event_callbacks, callbacks, byte_cnt);
450 }
451 }
452
453 // Called from JVMTI entry points which perform stack walking. If the
454 // associated JavaThread is the current thread, then wait_for_suspend
455 // is not used. Otherwise, it determines if we should wait for the
456 // "other" thread to complete external suspension. (NOTE: in future
457 // releases the suspension mechanism should be reimplemented so this
458 // is not necessary.)
459 //
460 bool
461 JvmtiEnvBase::is_thread_fully_suspended(JavaThread* thr, bool wait_for_suspend, uint32_t *bits) {
462 // "other" threads require special handling
463 if (thr != JavaThread::current()) {
464 if (wait_for_suspend) {
465 // We are allowed to wait for the external suspend to complete
466 // so give the other thread a chance to get suspended.
467 if (!thr->wait_for_ext_suspend_completion(SuspendRetryCount,
468 SuspendRetryDelay, bits)) {
469 // didn't make it so let the caller know
470 return false;
471 }
472 }
473 // We aren't allowed to wait for the external suspend to complete
474 // so if the other thread isn't externally suspended we need to
475 // let the caller know.
476 else if (!thr->is_ext_suspend_completed_with_lock(bits)) {
477 return false;
478 }
479 }
480
481 return true;
482 }
483
484
485 // In the fullness of time, all users of the method should instead
486 // directly use allocate, besides being cleaner and faster, this will
487 // mean much better out of memory handling
488 unsigned char *
489 JvmtiEnvBase::jvmtiMalloc(jlong size) {
490 unsigned char* mem;
491 jvmtiError result = allocate(size, &mem);
492 assert(result == JVMTI_ERROR_NONE, "Allocate failed");
493 return mem;
494 }
495
496
497 //
498 // Threads
499 //
500
501 jobject *
502 JvmtiEnvBase::new_jobjectArray(int length, Handle *handles) {
503 if (length == 0) {
504 return NULL;
505 }
506
507 jobject *objArray = (jobject *) jvmtiMalloc(sizeof(jobject) * length);
508 NULL_CHECK(objArray, NULL);
509
510 for (int i=0; i<length; i++) {
511 objArray[i] = jni_reference(handles[i]);
512 }
513 return objArray;
514 }
515
516 jthread *
517 JvmtiEnvBase::new_jthreadArray(int length, Handle *handles) {
518 return (jthread *) new_jobjectArray(length,handles);
519 }
520
521 jthreadGroup *
522 JvmtiEnvBase::new_jthreadGroupArray(int length, Handle *handles) {
523 return (jthreadGroup *) new_jobjectArray(length,handles);
524 }
525
526
527 JavaThread *
528 JvmtiEnvBase::get_JavaThread(jthread jni_thread) {
529 oop t = JNIHandles::resolve_external_guard(jni_thread);
530 if (t == NULL || !t->is_a(SystemDictionary::Thread_klass())) {
531 return NULL;
532 }
533 // The following returns NULL if the thread has not yet run or is in
534 // process of exiting
535 return java_lang_Thread::thread(t);
536 }
537
538
539 // update the access_flags for the field in the klass
540 void
541 JvmtiEnvBase::update_klass_field_access_flag(fieldDescriptor *fd) {
542 instanceKlass* ik = instanceKlass::cast(fd->field_holder());
543 typeArrayOop fields = ik->fields();
544 fields->ushort_at_put(fd->index(), (jushort)fd->access_flags().as_short());
545 }
546
547
548 // return the vframe on the specified thread and depth, NULL if no such frame
549 vframe*
550 JvmtiEnvBase::vframeFor(JavaThread* java_thread, jint depth) {
551 if (!java_thread->has_last_Java_frame()) {
552 return NULL;
553 }
554 RegisterMap reg_map(java_thread);
555 vframe *vf = java_thread->last_java_vframe(®_map);
556 int d = 0;
557 while ((vf != NULL) && (d < depth)) {
558 vf = vf->java_sender();
559 d++;
560 }
561 return vf;
562 }
563
564
565 //
566 // utilities: JNI objects
567 //
568
569
570 jclass
571 JvmtiEnvBase::get_jni_class_non_null(klassOop k) {
572 assert(k != NULL, "k != NULL");
573 return (jclass)jni_reference(Klass::cast(k)->java_mirror());
574 }
575
576 #ifndef JVMTI_KERNEL
577
578 //
579 // Field Information
580 //
581
582 bool
583 JvmtiEnvBase::get_field_descriptor(klassOop k, jfieldID field, fieldDescriptor* fd) {
584 if (!jfieldIDWorkaround::is_valid_jfieldID(k, field)) {
585 return false;
586 }
587 bool found = false;
588 if (jfieldIDWorkaround::is_static_jfieldID(field)) {
589 JNIid* id = jfieldIDWorkaround::from_static_jfieldID(field);
590 int offset = id->offset();
591 klassOop holder = id->holder();
592 found = instanceKlass::cast(holder)->find_local_field_from_offset(offset, true, fd);
593 } else {
594 // Non-static field. The fieldID is really the offset of the field within the object.
595 int offset = jfieldIDWorkaround::from_instance_jfieldID(k, field);
596 found = instanceKlass::cast(k)->find_field_from_offset(offset, false, fd);
597 }
598 return found;
599 }
600
601 //
602 // Object Monitor Information
603 //
604
605 //
606 // Count the number of objects for a lightweight monitor. The hobj
607 // parameter is object that owns the monitor so this routine will
608 // count the number of times the same object was locked by frames
609 // in java_thread.
610 //
611 jint
612 JvmtiEnvBase::count_locked_objects(JavaThread *java_thread, Handle hobj) {
613 jint ret = 0;
614 if (!java_thread->has_last_Java_frame()) {
615 return ret; // no Java frames so no monitors
616 }
617
618 ResourceMark rm;
619 HandleMark hm;
620 RegisterMap reg_map(java_thread);
621
622 for(javaVFrame *jvf=java_thread->last_java_vframe(®_map); jvf != NULL;
623 jvf = jvf->java_sender()) {
624 GrowableArray<MonitorInfo*>* mons = jvf->monitors();
625 if (!mons->is_empty()) {
626 for (int i = 0; i < mons->length(); i++) {
627 MonitorInfo *mi = mons->at(i);
628 if (mi->owner_is_scalar_replaced()) continue;
629
630 // see if owner of the monitor is our object
631 if (mi->owner() != NULL && mi->owner() == hobj()) {
632 ret++;
633 }
634 }
635 }
636 }
637 return ret;
638 }
639
640
641
642 jvmtiError
643 JvmtiEnvBase::get_current_contended_monitor(JavaThread *calling_thread, JavaThread *java_thread, jobject *monitor_ptr) {
644 #ifdef ASSERT
645 uint32_t debug_bits = 0;
646 #endif
647 assert((SafepointSynchronize::is_at_safepoint() ||
648 is_thread_fully_suspended(java_thread, false, &debug_bits)),
649 "at safepoint or target thread is suspended");
650 oop obj = NULL;
651 ObjectMonitor *mon = java_thread->current_waiting_monitor();
652 if (mon == NULL) {
653 // thread is not doing an Object.wait() call
654 mon = java_thread->current_pending_monitor();
655 if (mon != NULL) {
656 // The thread is trying to enter() or raw_enter() an ObjectMonitor.
657 obj = (oop)mon->object();
658 // If obj == NULL, then ObjectMonitor is raw which doesn't count
659 // as contended for this API
660 }
661 // implied else: no contended ObjectMonitor
662 } else {
663 // thread is doing an Object.wait() call
664 obj = (oop)mon->object();
665 assert(obj != NULL, "Object.wait() should have an object");
666 }
667
668 if (obj == NULL) {
669 *monitor_ptr = NULL;
670 } else {
671 HandleMark hm;
672 Handle hobj(obj);
673 *monitor_ptr = jni_reference(calling_thread, hobj);
674 }
675 return JVMTI_ERROR_NONE;
676 }
677
678
679 jvmtiError
680 JvmtiEnvBase::get_owned_monitors(JavaThread *calling_thread, JavaThread* java_thread,
681 GrowableArray<jvmtiMonitorStackDepthInfo*> *owned_monitors_list) {
682 jvmtiError err = JVMTI_ERROR_NONE;
683 #ifdef ASSERT
684 uint32_t debug_bits = 0;
685 #endif
686 assert((SafepointSynchronize::is_at_safepoint() ||
687 is_thread_fully_suspended(java_thread, false, &debug_bits)),
688 "at safepoint or target thread is suspended");
689
690 if (java_thread->has_last_Java_frame()) {
691 ResourceMark rm;
692 HandleMark hm;
693 RegisterMap reg_map(java_thread);
694
695 int depth = 0;
696 for (javaVFrame *jvf = java_thread->last_java_vframe(®_map); jvf != NULL;
697 jvf = jvf->java_sender()) {
698 if (depth++ < MaxJavaStackTraceDepth) { // check for stack too deep
699 // add locked objects for this frame into list
700 err = get_locked_objects_in_frame(calling_thread, java_thread, jvf, owned_monitors_list, depth-1);
701 if (err != JVMTI_ERROR_NONE) {
702 return err;
703 }
704 }
705 }
706 }
707
708 // Get off stack monitors. (e.g. acquired via jni MonitorEnter).
709 JvmtiMonitorClosure jmc(java_thread, calling_thread, owned_monitors_list, this);
710 ObjectSynchronizer::monitors_iterate(&jmc);
711 err = jmc.error();
712
713 return err;
714 }
715
716 // Save JNI local handles for any objects that this frame owns.
717 jvmtiError
718 JvmtiEnvBase::get_locked_objects_in_frame(JavaThread* calling_thread, JavaThread* java_thread,
719 javaVFrame *jvf, GrowableArray<jvmtiMonitorStackDepthInfo*>* owned_monitors_list, int stack_depth) {
720 jvmtiError err = JVMTI_ERROR_NONE;
721 ResourceMark rm;
722
723 GrowableArray<MonitorInfo*>* mons = jvf->monitors();
724 if (mons->is_empty()) {
725 return err; // this javaVFrame holds no monitors
726 }
727
728 HandleMark hm;
729 oop wait_obj = NULL;
730 {
731 // save object of current wait() call (if any) for later comparison
732 ObjectMonitor *mon = java_thread->current_waiting_monitor();
733 if (mon != NULL) {
734 wait_obj = (oop)mon->object();
735 }
736 }
737 oop pending_obj = NULL;
738 {
739 // save object of current enter() call (if any) for later comparison
740 ObjectMonitor *mon = java_thread->current_pending_monitor();
741 if (mon != NULL) {
742 pending_obj = (oop)mon->object();
743 }
744 }
745
746 for (int i = 0; i < mons->length(); i++) {
747 MonitorInfo *mi = mons->at(i);
748
749 if (mi->owner_is_scalar_replaced()) continue;
750
751 oop obj = mi->owner();
752 if (obj == NULL) {
753 // this monitor doesn't have an owning object so skip it
754 continue;
755 }
756
757 if (wait_obj == obj) {
758 // the thread is waiting on this monitor so it isn't really owned
759 continue;
760 }
761
762 if (pending_obj == obj) {
763 // the thread is pending on this monitor so it isn't really owned
764 continue;
765 }
766
767 if (owned_monitors_list->length() > 0) {
768 // Our list has at least one object on it so we have to check
769 // for recursive object locking
770 bool found = false;
771 for (int j = 0; j < owned_monitors_list->length(); j++) {
772 jobject jobj = ((jvmtiMonitorStackDepthInfo*)owned_monitors_list->at(j))->monitor;
773 oop check = JNIHandles::resolve(jobj);
774 if (check == obj) {
775 found = true; // we found the object
776 break;
777 }
778 }
779
780 if (found) {
781 // already have this object so don't include it
782 continue;
783 }
784 }
785
786 // add the owning object to our list
787 jvmtiMonitorStackDepthInfo *jmsdi;
788 err = allocate(sizeof(jvmtiMonitorStackDepthInfo), (unsigned char **)&jmsdi);
789 if (err != JVMTI_ERROR_NONE) {
790 return err;
791 }
792 Handle hobj(obj);
793 jmsdi->monitor = jni_reference(calling_thread, hobj);
794 jmsdi->stack_depth = stack_depth;
795 owned_monitors_list->append(jmsdi);
796 }
797
798 return err;
799 }
800
801 jvmtiError
802 JvmtiEnvBase::get_stack_trace(JavaThread *java_thread,
803 jint start_depth, jint max_count,
804 jvmtiFrameInfo* frame_buffer, jint* count_ptr) {
805 #ifdef ASSERT
806 uint32_t debug_bits = 0;
807 #endif
808 assert((SafepointSynchronize::is_at_safepoint() ||
809 is_thread_fully_suspended(java_thread, false, &debug_bits)),
810 "at safepoint or target thread is suspended");
811 int count = 0;
812 if (java_thread->has_last_Java_frame()) {
813 RegisterMap reg_map(java_thread);
814 Thread* current_thread = Thread::current();
815 ResourceMark rm(current_thread);
816 javaVFrame *jvf = java_thread->last_java_vframe(®_map);
817 HandleMark hm(current_thread);
818 if (start_depth != 0) {
819 if (start_depth > 0) {
820 for (int j = 0; j < start_depth && jvf != NULL; j++) {
821 jvf = jvf->java_sender();
822 }
823 if (jvf == NULL) {
824 // start_depth is deeper than the stack depth
825 return JVMTI_ERROR_ILLEGAL_ARGUMENT;
826 }
827 } else { // start_depth < 0
828 // we are referencing the starting depth based on the oldest
829 // part of the stack.
830 // optimize to limit the number of times that java_sender() is called
831 javaVFrame *jvf_cursor = jvf;
832 javaVFrame *jvf_prev = NULL;
833 javaVFrame *jvf_prev_prev;
834 int j = 0;
835 while (jvf_cursor != NULL) {
836 jvf_prev_prev = jvf_prev;
837 jvf_prev = jvf_cursor;
838 for (j = 0; j > start_depth && jvf_cursor != NULL; j--) {
839 jvf_cursor = jvf_cursor->java_sender();
840 }
841 }
842 if (j == start_depth) {
843 // previous pointer is exactly where we want to start
844 jvf = jvf_prev;
845 } else {
846 // we need to back up further to get to the right place
847 if (jvf_prev_prev == NULL) {
848 // the -start_depth is greater than the stack depth
849 return JVMTI_ERROR_ILLEGAL_ARGUMENT;
850 }
851 // j now is the number of frames on the stack starting with
852 // jvf_prev, we start from jvf_prev_prev and move older on
853 // the stack that many, the result is -start_depth frames
854 // remaining.
855 jvf = jvf_prev_prev;
856 for (; j < 0; j++) {
857 jvf = jvf->java_sender();
858 }
859 }
860 }
861 }
862 for (; count < max_count && jvf != NULL; count++) {
863 frame_buffer[count].method = jvf->method()->jmethod_id();
864 frame_buffer[count].location = (jvf->method()->is_native() ? -1 : jvf->bci());
865 jvf = jvf->java_sender();
866 }
867 } else {
868 if (start_depth != 0) {
869 // no frames and there is a starting depth
870 return JVMTI_ERROR_ILLEGAL_ARGUMENT;
871 }
872 }
873 *count_ptr = count;
874 return JVMTI_ERROR_NONE;
875 }
876
877 jvmtiError
878 JvmtiEnvBase::get_frame_count(JvmtiThreadState *state, jint *count_ptr) {
879 assert((state != NULL),
880 "JavaThread should create JvmtiThreadState before calling this method");
881 *count_ptr = state->count_frames();
882 return JVMTI_ERROR_NONE;
883 }
884
885 jvmtiError
886 JvmtiEnvBase::get_frame_location(JavaThread *java_thread, jint depth,
887 jmethodID* method_ptr, jlocation* location_ptr) {
888 #ifdef ASSERT
889 uint32_t debug_bits = 0;
890 #endif
891 assert((SafepointSynchronize::is_at_safepoint() ||
892 is_thread_fully_suspended(java_thread, false, &debug_bits)),
893 "at safepoint or target thread is suspended");
894 Thread* current_thread = Thread::current();
895 ResourceMark rm(current_thread);
896
897 vframe *vf = vframeFor(java_thread, depth);
898 if (vf == NULL) {
899 return JVMTI_ERROR_NO_MORE_FRAMES;
900 }
901
902 // vframeFor should return a java frame. If it doesn't
903 // it means we've got an internal error and we return the
904 // error in product mode. In debug mode we will instead
905 // attempt to cast the vframe to a javaVFrame and will
906 // cause an assertion/crash to allow further diagnosis.
907 #ifdef PRODUCT
908 if (!vf->is_java_frame()) {
909 return JVMTI_ERROR_INTERNAL;
910 }
911 #endif
912
913 HandleMark hm(current_thread);
914 javaVFrame *jvf = javaVFrame::cast(vf);
915 methodOop method = jvf->method();
916 if (method->is_native()) {
917 *location_ptr = -1;
918 } else {
919 *location_ptr = jvf->bci();
920 }
921 *method_ptr = method->jmethod_id();
922
923 return JVMTI_ERROR_NONE;
924 }
925
926
927 jvmtiError
928 JvmtiEnvBase::get_object_monitor_usage(JavaThread* calling_thread, jobject object, jvmtiMonitorUsage* info_ptr) {
929 HandleMark hm;
930 Handle hobj;
931
932 bool at_safepoint = SafepointSynchronize::is_at_safepoint();
933
934 // Check arguments
935 {
936 oop mirror = JNIHandles::resolve_external_guard(object);
937 NULL_CHECK(mirror, JVMTI_ERROR_INVALID_OBJECT);
938 NULL_CHECK(info_ptr, JVMTI_ERROR_NULL_POINTER);
939
940 hobj = Handle(mirror);
941 }
942
943 JavaThread *owning_thread = NULL;
944 ObjectMonitor *mon = NULL;
945 jvmtiMonitorUsage ret = {
946 NULL, 0, 0, NULL, 0, NULL
947 };
948
949 uint32_t debug_bits = 0;
950 // first derive the object's owner and entry_count (if any)
951 {
952 // Revoke any biases before querying the mark word
953 if (SafepointSynchronize::is_at_safepoint()) {
954 BiasedLocking::revoke_at_safepoint(hobj);
955 } else {
956 BiasedLocking::revoke_and_rebias(hobj, false, calling_thread);
957 }
958
959 address owner = NULL;
960 {
961 markOop mark = hobj()->mark();
962
963 if (!mark->has_monitor()) {
964 // this object has a lightweight monitor
965
966 if (mark->has_locker()) {
967 owner = (address)mark->locker(); // save the address of the Lock word
968 }
969 // implied else: no owner
970 } else {
971 // this object has a heavyweight monitor
972 mon = mark->monitor();
973
974 // The owner field of a heavyweight monitor may be NULL for no
975 // owner, a JavaThread * or it may still be the address of the
976 // Lock word in a JavaThread's stack. A monitor can be inflated
977 // by a non-owning JavaThread, but only the owning JavaThread
978 // can change the owner field from the Lock word to the
979 // JavaThread * and it may not have done that yet.
980 owner = (address)mon->owner();
981 }
982 }
983
984 if (owner != NULL) {
985 // This monitor is owned so we have to find the owning JavaThread.
986 // Since owning_thread_from_monitor_owner() grabs a lock, GC can
987 // move our object at this point. However, our owner value is safe
988 // since it is either the Lock word on a stack or a JavaThread *.
989 owning_thread = Threads::owning_thread_from_monitor_owner(owner, !at_safepoint);
990 assert(owning_thread != NULL, "sanity check");
991 if (owning_thread != NULL) { // robustness
992 // The monitor's owner either has to be the current thread, at safepoint
993 // or it has to be suspended. Any of these conditions will prevent both
994 // contending and waiting threads from modifying the state of
995 // the monitor.
996 if (!at_safepoint && !JvmtiEnv::is_thread_fully_suspended(owning_thread, true, &debug_bits)) {
997 return JVMTI_ERROR_THREAD_NOT_SUSPENDED;
998 }
999 HandleMark hm;
1000 Handle th(owning_thread->threadObj());
1001 ret.owner = (jthread)jni_reference(calling_thread, th);
1002 }
1003 // implied else: no owner
1004 }
1005
1006 if (owning_thread != NULL) { // monitor is owned
1007 if ((address)owning_thread == owner) {
1008 // the owner field is the JavaThread *
1009 assert(mon != NULL,
1010 "must have heavyweight monitor with JavaThread * owner");
1011 ret.entry_count = mon->recursions() + 1;
1012 } else {
1013 // The owner field is the Lock word on the JavaThread's stack
1014 // so the recursions field is not valid. We have to count the
1015 // number of recursive monitor entries the hard way. We pass
1016 // a handle to survive any GCs along the way.
1017 ResourceMark rm;
1018 ret.entry_count = count_locked_objects(owning_thread, hobj);
1019 }
1020 }
1021 // implied else: entry_count == 0
1022 }
1023
1024 int nWant,nWait;
1025 if (mon != NULL) {
1026 // this object has a heavyweight monitor
1027 nWant = mon->contentions(); // # of threads contending for monitor
1028 nWait = mon->waiters(); // # of threads in Object.wait()
1029 ret.waiter_count = nWant + nWait;
1030 ret.notify_waiter_count = nWait;
1031 } else {
1032 // this object has a lightweight monitor
1033 ret.waiter_count = 0;
1034 ret.notify_waiter_count = 0;
1035 }
1036
1037 // Allocate memory for heavyweight and lightweight monitor.
1038 jvmtiError err;
1039 err = allocate(ret.waiter_count * sizeof(jthread *), (unsigned char**)&ret.waiters);
1040 if (err != JVMTI_ERROR_NONE) {
1041 return err;
1042 }
1043 err = allocate(ret.notify_waiter_count * sizeof(jthread *),
1044 (unsigned char**)&ret.notify_waiters);
1045 if (err != JVMTI_ERROR_NONE) {
1046 deallocate((unsigned char*)ret.waiters);
1047 return err;
1048 }
1049
1050 // now derive the rest of the fields
1051 if (mon != NULL) {
1052 // this object has a heavyweight monitor
1053
1054 // Number of waiters may actually be less than the waiter count.
1055 // So NULL out memory so that unused memory will be NULL.
1056 memset(ret.waiters, 0, ret.waiter_count * sizeof(jthread *));
1057 memset(ret.notify_waiters, 0, ret.notify_waiter_count * sizeof(jthread *));
1058
1059 if (ret.waiter_count > 0) {
1060 // we have contending and/or waiting threads
1061 HandleMark hm;
1062 if (nWant > 0) {
1063 // we have contending threads
1064 ResourceMark rm;
1065 // get_pending_threads returns only java thread so we do not need to
1066 // check for non java threads.
1067 GrowableArray<JavaThread*>* wantList = Threads::get_pending_threads(
1068 nWant, (address)mon, !at_safepoint);
1069 if (wantList->length() < nWant) {
1070 // robustness: the pending list has gotten smaller
1071 nWant = wantList->length();
1072 }
1073 for (int i = 0; i < nWant; i++) {
1074 JavaThread *pending_thread = wantList->at(i);
1075 // If the monitor has no owner, then a non-suspended contending
1076 // thread could potentially change the state of the monitor by
1077 // entering it. The JVM/TI spec doesn't allow this.
1078 if (owning_thread == NULL && !at_safepoint &
1079 !JvmtiEnv::is_thread_fully_suspended(pending_thread, true, &debug_bits)) {
1080 if (ret.owner != NULL) {
1081 destroy_jni_reference(calling_thread, ret.owner);
1082 }
1083 for (int j = 0; j < i; j++) {
1084 destroy_jni_reference(calling_thread, ret.waiters[j]);
1085 }
1086 deallocate((unsigned char*)ret.waiters);
1087 deallocate((unsigned char*)ret.notify_waiters);
1088 return JVMTI_ERROR_THREAD_NOT_SUSPENDED;
1089 }
1090 Handle th(pending_thread->threadObj());
1091 ret.waiters[i] = (jthread)jni_reference(calling_thread, th);
1092 }
1093 }
1094 if (nWait > 0) {
1095 // we have threads in Object.wait()
1096 int offset = nWant; // add after any contending threads
1097 ObjectWaiter *waiter = mon->first_waiter();
1098 for (int i = 0, j = 0; i < nWait; i++) {
1099 if (waiter == NULL) {
1100 // robustness: the waiting list has gotten smaller
1101 nWait = j;
1102 break;
1103 }
1104 Thread *t = mon->thread_of_waiter(waiter);
1105 if (t != NULL && t->is_Java_thread()) {
1106 JavaThread *wjava_thread = (JavaThread *)t;
1107 // If the thread was found on the ObjectWaiter list, then
1108 // it has not been notified. This thread can't change the
1109 // state of the monitor so it doesn't need to be suspended.
1110 Handle th(wjava_thread->threadObj());
1111 ret.waiters[offset + j] = (jthread)jni_reference(calling_thread, th);
1112 ret.notify_waiters[j++] = (jthread)jni_reference(calling_thread, th);
1113 }
1114 waiter = mon->next_waiter(waiter);
1115 }
1116 }
1117 }
1118
1119 // Adjust count. nWant and nWait count values may be less than original.
1120 ret.waiter_count = nWant + nWait;
1121 ret.notify_waiter_count = nWait;
1122 } else {
1123 // this object has a lightweight monitor and we have nothing more
1124 // to do here because the defaults are just fine.
1125 }
1126
1127 // we don't update return parameter unless everything worked
1128 *info_ptr = ret;
1129
1130 return JVMTI_ERROR_NONE;
1131 }
1132
1133 ResourceTracker::ResourceTracker(JvmtiEnv* env) {
1134 _env = env;
1135 _allocations = new (ResourceObj::C_HEAP) GrowableArray<unsigned char*>(20, true);
1136 _failed = false;
1137 }
1138 ResourceTracker::~ResourceTracker() {
1139 if (_failed) {
1140 for (int i=0; i<_allocations->length(); i++) {
1141 _env->deallocate(_allocations->at(i));
1142 }
1143 }
1144 delete _allocations;
1145 }
1146
1147 jvmtiError ResourceTracker::allocate(jlong size, unsigned char** mem_ptr) {
1148 unsigned char *ptr;
1149 jvmtiError err = _env->allocate(size, &ptr);
1150 if (err == JVMTI_ERROR_NONE) {
1151 _allocations->append(ptr);
1152 *mem_ptr = ptr;
1153 } else {
1154 *mem_ptr = NULL;
1155 _failed = true;
1156 }
1157 return err;
1158 }
1159
1160 unsigned char* ResourceTracker::allocate(jlong size) {
1161 unsigned char* ptr;
1162 allocate(size, &ptr);
1163 return ptr;
1164 }
1165
1166 char* ResourceTracker::strdup(const char* str) {
1167 char *dup_str = (char*)allocate(strlen(str)+1);
1168 if (dup_str != NULL) {
1169 strcpy(dup_str, str);
1170 }
1171 return dup_str;
1172 }
1173
1174 struct StackInfoNode {
1175 struct StackInfoNode *next;
1176 jvmtiStackInfo info;
1177 };
1178
1179 // Create a jvmtiStackInfo inside a linked list node and create a
1180 // buffer for the frame information, both allocated as resource objects.
1181 // Fill in both the jvmtiStackInfo and the jvmtiFrameInfo.
1182 // Note that either or both of thr and thread_oop
1183 // may be null if the thread is new or has exited.
1184 void
1185 VM_GetMultipleStackTraces::fill_frames(jthread jt, JavaThread *thr, oop thread_oop) {
1186 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
1187
1188 jint state = 0;
1189 struct StackInfoNode *node = NEW_RESOURCE_OBJ(struct StackInfoNode);
1190 jvmtiStackInfo *infop = &(node->info);
1191 node->next = head();
1192 set_head(node);
1193 infop->frame_count = 0;
1194 infop->thread = jt;
1195
1196 if (thread_oop != NULL) {
1197 // get most state bits
1198 state = (jint)java_lang_Thread::get_thread_status(thread_oop);
1199 }
1200
1201 if (thr != NULL) { // add more state bits if there is a JavaThead to query
1202 // same as is_being_ext_suspended() but without locking
1203 if (thr->is_ext_suspended() || thr->is_external_suspend()) {
1204 state |= JVMTI_THREAD_STATE_SUSPENDED;
1205 }
1206 JavaThreadState jts = thr->thread_state();
1207 if (jts == _thread_in_native) {
1208 state |= JVMTI_THREAD_STATE_IN_NATIVE;
1209 }
1210 OSThread* osThread = thr->osthread();
1211 if (osThread != NULL && osThread->interrupted()) {
1212 state |= JVMTI_THREAD_STATE_INTERRUPTED;
1213 }
1214 }
1215 infop->state = state;
1216
1217 if (thr != NULL || (state & JVMTI_THREAD_STATE_ALIVE) != 0) {
1218 infop->frame_buffer = NEW_RESOURCE_ARRAY(jvmtiFrameInfo, max_frame_count());
1219 env()->get_stack_trace(thr, 0, max_frame_count(),
1220 infop->frame_buffer, &(infop->frame_count));
1221 } else {
1222 infop->frame_buffer = NULL;
1223 infop->frame_count = 0;
1224 }
1225 _frame_count_total += infop->frame_count;
1226 }
1227
1228 // Based on the stack information in the linked list, allocate memory
1229 // block to return and fill it from the info in the linked list.
1230 void
1231 VM_GetMultipleStackTraces::allocate_and_fill_stacks(jint thread_count) {
1232 // do I need to worry about alignment issues?
1233 jlong alloc_size = thread_count * sizeof(jvmtiStackInfo)
1234 + _frame_count_total * sizeof(jvmtiFrameInfo);
1235 env()->allocate(alloc_size, (unsigned char **)&_stack_info);
1236
1237 // pointers to move through the newly allocated space as it is filled in
1238 jvmtiStackInfo *si = _stack_info + thread_count; // bottom of stack info
1239 jvmtiFrameInfo *fi = (jvmtiFrameInfo *)si; // is the top of frame info
1240
1241 // copy information in resource area into allocated buffer
1242 // insert stack info backwards since linked list is backwards
1243 // insert frame info forwards
1244 // walk the StackInfoNodes
1245 for (struct StackInfoNode *sin = head(); sin != NULL; sin = sin->next) {
1246 jint frame_count = sin->info.frame_count;
1247 size_t frames_size = frame_count * sizeof(jvmtiFrameInfo);
1248 --si;
1249 memcpy(si, &(sin->info), sizeof(jvmtiStackInfo));
1250 if (frames_size == 0) {
1251 si->frame_buffer = NULL;
1252 } else {
1253 memcpy(fi, sin->info.frame_buffer, frames_size);
1254 si->frame_buffer = fi; // point to the new allocated copy of the frames
1255 fi += frame_count;
1256 }
1257 }
1258 assert(si == _stack_info, "the last copied stack info must be the first record");
1259 assert((unsigned char *)fi == ((unsigned char *)_stack_info) + alloc_size,
1260 "the last copied frame info must be the last record");
1261 }
1262
1263
1264 void
1265 VM_GetThreadListStackTraces::doit() {
1266 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
1267
1268 ResourceMark rm;
1269 for (int i = 0; i < _thread_count; ++i) {
1270 jthread jt = _thread_list[i];
1271 oop thread_oop = JNIHandles::resolve_external_guard(jt);
1272 if (thread_oop == NULL || !thread_oop->is_a(SystemDictionary::Thread_klass())) {
1273 set_result(JVMTI_ERROR_INVALID_THREAD);
1274 return;
1275 }
1276 fill_frames(jt, java_lang_Thread::thread(thread_oop), thread_oop);
1277 }
1278 allocate_and_fill_stacks(_thread_count);
1279 }
1280
1281 void
1282 VM_GetAllStackTraces::doit() {
1283 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
1284
1285 ResourceMark rm;
1286 _final_thread_count = 0;
1287 for (JavaThread *jt = Threads::first(); jt != NULL; jt = jt->next()) {
1288 oop thread_oop = jt->threadObj();
1289 if (thread_oop != NULL &&
1290 !jt->is_exiting() &&
1291 java_lang_Thread::is_alive(thread_oop) &&
1292 !jt->is_hidden_from_external_view()) {
1293 ++_final_thread_count;
1294 // Handle block of the calling thread is used to create local refs.
1295 fill_frames((jthread)JNIHandles::make_local(_calling_thread, thread_oop),
1296 jt, thread_oop);
1297 }
1298 }
1299 allocate_and_fill_stacks(_final_thread_count);
1300 }
1301
1302 // Verifies that the top frame is a java frame in an expected state.
1303 // Deoptimizes frame if needed.
1304 // Checks that the frame method signature matches the return type (tos).
1305 // HandleMark must be defined in the caller only.
1306 // It is to keep a ret_ob_h handle alive after return to the caller.
1307 jvmtiError
1308 JvmtiEnvBase::check_top_frame(JavaThread* current_thread, JavaThread* java_thread,
1309 jvalue value, TosState tos, Handle* ret_ob_h) {
1310 ResourceMark rm(current_thread);
1311
1312 vframe *vf = vframeFor(java_thread, 0);
1313 NULL_CHECK(vf, JVMTI_ERROR_NO_MORE_FRAMES);
1314
1315 javaVFrame *jvf = (javaVFrame*) vf;
1316 if (!vf->is_java_frame() || jvf->method()->is_native()) {
1317 return JVMTI_ERROR_OPAQUE_FRAME;
1318 }
1319
1320 // If the frame is a compiled one, need to deoptimize it.
1321 if (vf->is_compiled_frame()) {
1322 if (!vf->fr().can_be_deoptimized()) {
1323 return JVMTI_ERROR_OPAQUE_FRAME;
1324 }
1325 VM_DeoptimizeFrame deopt(java_thread, jvf->fr().id());
1326 VMThread::execute(&deopt);
1327 }
1328
1329 // Get information about method return type
1330 symbolHandle signature(current_thread, jvf->method()->signature());
1331
1332 ResultTypeFinder rtf(signature);
1333 TosState fr_tos = as_TosState(rtf.type());
1334 if (fr_tos != tos) {
1335 if (tos != itos || (fr_tos != btos && fr_tos != ctos && fr_tos != stos)) {
1336 return JVMTI_ERROR_TYPE_MISMATCH;
1337 }
1338 }
1339
1340 // Check that the jobject class matches the return type signature.
1341 jobject jobj = value.l;
1342 if (tos == atos && jobj != NULL) { // NULL reference is allowed
1343 Handle ob_h = Handle(current_thread, JNIHandles::resolve_external_guard(jobj));
1344 NULL_CHECK(ob_h, JVMTI_ERROR_INVALID_OBJECT);
1345 KlassHandle ob_kh = KlassHandle(current_thread, ob_h()->klass());
1346 NULL_CHECK(ob_kh, JVMTI_ERROR_INVALID_OBJECT);
1347
1348 // Method return type signature.
1349 char* ty_sign = 1 + strchr(signature->as_C_string(), ')');
1350
1351 if (!VM_GetOrSetLocal::is_assignable(ty_sign, Klass::cast(ob_kh()), current_thread)) {
1352 return JVMTI_ERROR_TYPE_MISMATCH;
1353 }
1354 *ret_ob_h = ob_h;
1355 }
1356 return JVMTI_ERROR_NONE;
1357 } /* end check_top_frame */
1358
1359
1360 // ForceEarlyReturn<type> follows the PopFrame approach in many aspects.
1361 // Main difference is on the last stage in the interpreter.
1362 // The PopFrame stops method execution to continue execution
1363 // from the same method call instruction.
1364 // The ForceEarlyReturn forces return from method so the execution
1365 // continues at the bytecode following the method call.
1366
1367 // Threads_lock NOT held, java_thread not protected by lock
1368 // java_thread - pre-checked
1369
1370 jvmtiError
1371 JvmtiEnvBase::force_early_return(JavaThread* java_thread, jvalue value, TosState tos) {
1372 JavaThread* current_thread = JavaThread::current();
1373 HandleMark hm(current_thread);
1374 uint32_t debug_bits = 0;
1375
1376 // retrieve or create the state
1377 JvmtiThreadState* state = JvmtiThreadState::state_for(java_thread);
1378 if (state == NULL) {
1379 return JVMTI_ERROR_THREAD_NOT_ALIVE;
1380 }
1381
1382 // Check if java_thread is fully suspended
1383 if (!is_thread_fully_suspended(java_thread,
1384 true /* wait for suspend completion */,
1385 &debug_bits)) {
1386 return JVMTI_ERROR_THREAD_NOT_SUSPENDED;
1387 }
1388
1389 // Check to see if a ForceEarlyReturn was already in progress
1390 if (state->is_earlyret_pending()) {
1391 // Probably possible for JVMTI clients to trigger this, but the
1392 // JPDA backend shouldn't allow this to happen
1393 return JVMTI_ERROR_INTERNAL;
1394 }
1395 {
1396 // The same as for PopFrame. Workaround bug:
1397 // 4812902: popFrame hangs if the method is waiting at a synchronize
1398 // Catch this condition and return an error to avoid hanging.
1399 // Now JVMTI spec allows an implementation to bail out with an opaque
1400 // frame error.
1401 OSThread* osThread = java_thread->osthread();
1402 if (osThread->get_state() == MONITOR_WAIT) {
1403 return JVMTI_ERROR_OPAQUE_FRAME;
1404 }
1405 }
1406 Handle ret_ob_h = Handle();
1407 jvmtiError err = check_top_frame(current_thread, java_thread, value, tos, &ret_ob_h);
1408 if (err != JVMTI_ERROR_NONE) {
1409 return err;
1410 }
1411 assert(tos != atos || value.l == NULL || ret_ob_h() != NULL,
1412 "return object oop must not be NULL if jobject is not NULL");
1413
1414 // Update the thread state to reflect that the top frame must be
1415 // forced to return.
1416 // The current frame will be returned later when the suspended
1417 // thread is resumed and right before returning from VM to Java.
1418 // (see call_VM_base() in assembler_<cpu>.cpp).
1419
1420 state->set_earlyret_pending();
1421 state->set_earlyret_oop(ret_ob_h());
1422 state->set_earlyret_value(value, tos);
1423
1424 // Set pending step flag for this early return.
1425 // It is cleared when next step event is posted.
1426 state->set_pending_step_for_earlyret();
1427
1428 return JVMTI_ERROR_NONE;
1429 } /* end force_early_return */
1430
1431 void
1432 JvmtiMonitorClosure::do_monitor(ObjectMonitor* mon) {
1433 if ( _error != JVMTI_ERROR_NONE) {
1434 // Error occurred in previous iteration so no need to add
1435 // to the list.
1436 return;
1437 }
1438 if (mon->owner() == _java_thread ) {
1439 // Filter out on stack monitors collected during stack walk.
1440 oop obj = (oop)mon->object();
1441 bool found = false;
1442 for (int j = 0; j < _owned_monitors_list->length(); j++) {
1443 jobject jobj = ((jvmtiMonitorStackDepthInfo*)_owned_monitors_list->at(j))->monitor;
1444 oop check = JNIHandles::resolve(jobj);
1445 if (check == obj) {
1446 // On stack monitor already collected during the stack walk.
1447 found = true;
1448 break;
1449 }
1450 }
1451 if (found == false) {
1452 // This is off stack monitor (e.g. acquired via jni MonitorEnter).
1453 jvmtiError err;
1454 jvmtiMonitorStackDepthInfo *jmsdi;
1455 err = _env->allocate(sizeof(jvmtiMonitorStackDepthInfo), (unsigned char **)&jmsdi);
1456 if (err != JVMTI_ERROR_NONE) {
1457 _error = err;
1458 return;
1459 }
1460 Handle hobj(obj);
1461 jmsdi->monitor = _env->jni_reference(_calling_thread, hobj);
1462 // stack depth is unknown for this monitor.
1463 jmsdi->stack_depth = -1;
1464 _owned_monitors_list->append(jmsdi);
1465 }
1466 }
1467 }
1468
1469 #endif // !JVMTI_KERNEL