1 /*
2 * Copyright (c) 2003, 2019, 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 "classfile/classLoaderDataGraph.hpp"
27 #include "classfile/moduleEntry.hpp"
28 #include "classfile/systemDictionary.hpp"
29 #include "jvmtifiles/jvmtiEnv.hpp"
30 #include "memory/resourceArea.hpp"
31 #include "oops/objArrayKlass.hpp"
32 #include "oops/objArrayOop.hpp"
33 #include "oops/oop.inline.hpp"
34 #include "oops/oopHandle.inline.hpp"
35 #include "prims/jvmtiEnvBase.hpp"
36 #include "prims/jvmtiEventController.inline.hpp"
37 #include "prims/jvmtiExtensions.hpp"
38 #include "prims/jvmtiImpl.hpp"
39 #include "prims/jvmtiManageCapabilities.hpp"
40 #include "prims/jvmtiTagMap.hpp"
41 #include "prims/jvmtiThreadState.inline.hpp"
42 #include "runtime/biasedLocking.hpp"
43 #include "runtime/deoptimization.hpp"
44 #include "runtime/frame.inline.hpp"
45 #include "runtime/handles.inline.hpp"
46 #include "runtime/interfaceSupport.inline.hpp"
47 #include "runtime/jfieldIDWorkaround.hpp"
48 #include "runtime/jniHandles.inline.hpp"
49 #include "runtime/objectMonitor.hpp"
50 #include "runtime/objectMonitor.inline.hpp"
51 #include "runtime/signature.hpp"
52 #include "runtime/thread.inline.hpp"
53 #include "runtime/threadSMR.hpp"
54 #include "runtime/vframe.hpp"
55 #include "runtime/vframe_hp.hpp"
56 #include "runtime/vmThread.hpp"
57 #include "runtime/vmOperations.hpp"
58
59 ///////////////////////////////////////////////////////////////
60 //
61 // JvmtiEnvBase
62 //
63
64 JvmtiEnvBase* JvmtiEnvBase::_head_environment = NULL;
65
66 bool JvmtiEnvBase::_globally_initialized = false;
67 volatile bool JvmtiEnvBase::_needs_clean_up = false;
68
69 jvmtiPhase JvmtiEnvBase::_phase = JVMTI_PHASE_PRIMORDIAL;
70
71 volatile int JvmtiEnvBase::_dying_thread_env_iteration_count = 0;
72
73 extern jvmtiInterface_1_ jvmti_Interface;
74 extern jvmtiInterface_1_ jvmtiTrace_Interface;
75
76
77 // perform initializations that must occur before any JVMTI environments
78 // are released but which should only be initialized once (no matter
79 // how many environments are created).
80 void
81 JvmtiEnvBase::globally_initialize() {
82 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
83 assert(_globally_initialized == false, "bad call");
84
85 JvmtiManageCapabilities::initialize();
86
87 // register extension functions and events
88 JvmtiExtensions::register_extensions();
89
90 #ifdef JVMTI_TRACE
91 JvmtiTrace::initialize();
92 #endif
93
94 _globally_initialized = true;
95 }
96
97
98 void
99 JvmtiEnvBase::initialize() {
100 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
101
102 // Add this environment to the end of the environment list (order is important)
103 {
104 // This block of code must not contain any safepoints, as list deallocation
105 // (which occurs at a safepoint) cannot occur simultaneously with this list
106 // addition. Note: NoSafepointVerifier cannot, currently, be used before
107 // threads exist.
108 JvmtiEnvIterator it;
109 JvmtiEnvBase *previous_env = NULL;
110 for (JvmtiEnvBase* env = it.first(); env != NULL; env = it.next(env)) {
111 previous_env = env;
112 }
113 if (previous_env == NULL) {
114 _head_environment = this;
115 } else {
116 previous_env->set_next_environment(this);
117 }
118 }
119
120 if (_globally_initialized == false) {
121 globally_initialize();
122 }
123 }
124
125 jvmtiPhase
126 JvmtiEnvBase::phase() {
127 // For the JVMTI environments possessed the can_generate_early_vmstart:
128 // replace JVMTI_PHASE_PRIMORDIAL with JVMTI_PHASE_START
129 if (_phase == JVMTI_PHASE_PRIMORDIAL &&
130 JvmtiExport::early_vmstart_recorded() &&
131 early_vmstart_env()) {
132 return JVMTI_PHASE_START;
133 }
134 return _phase; // Normal case
135 }
136
137 bool
138 JvmtiEnvBase::is_valid() {
139 jint value = 0;
140
141 // This object might not be a JvmtiEnvBase so we can't assume
142 // the _magic field is properly aligned. Get the value in a safe
143 // way and then check against JVMTI_MAGIC.
144
145 switch (sizeof(_magic)) {
146 case 2:
147 value = Bytes::get_native_u2((address)&_magic);
148 break;
149
150 case 4:
151 value = Bytes::get_native_u4((address)&_magic);
152 break;
153
154 case 8:
155 value = Bytes::get_native_u8((address)&_magic);
156 break;
157
158 default:
159 guarantee(false, "_magic field is an unexpected size");
160 }
161
162 return value == JVMTI_MAGIC;
163 }
164
165
166 bool
167 JvmtiEnvBase::use_version_1_0_semantics() {
168 int major, minor, micro;
169
170 JvmtiExport::decode_version_values(_version, &major, &minor, µ);
171 return major == 1 && minor == 0; // micro version doesn't matter here
172 }
173
174
175 bool
176 JvmtiEnvBase::use_version_1_1_semantics() {
177 int major, minor, micro;
178
179 JvmtiExport::decode_version_values(_version, &major, &minor, µ);
180 return major == 1 && minor == 1; // micro version doesn't matter here
181 }
182
183 bool
184 JvmtiEnvBase::use_version_1_2_semantics() {
185 int major, minor, micro;
186
187 JvmtiExport::decode_version_values(_version, &major, &minor, µ);
188 return major == 1 && minor == 2; // micro version doesn't matter here
189 }
190
191
192 JvmtiEnvBase::JvmtiEnvBase(jint version) : _env_event_enable() {
193 _version = version;
194 _env_local_storage = NULL;
195 _tag_map = NULL;
196 _native_method_prefix_count = 0;
197 _native_method_prefixes = NULL;
198 _next = NULL;
199 _class_file_load_hook_ever_enabled = false;
200
201 // Moot since ClassFileLoadHook not yet enabled.
202 // But "true" will give a more predictable ClassFileLoadHook behavior
203 // for environment creation during ClassFileLoadHook.
204 _is_retransformable = true;
205
206 // all callbacks initially NULL
207 memset(&_event_callbacks,0,sizeof(jvmtiEventCallbacks));
208
209 // all capabilities initially off
210 memset(&_current_capabilities, 0, sizeof(_current_capabilities));
211
212 // all prohibited capabilities initially off
213 memset(&_prohibited_capabilities, 0, sizeof(_prohibited_capabilities));
214
215 _magic = JVMTI_MAGIC;
216
217 JvmtiEventController::env_initialize((JvmtiEnv*)this);
218
219 #ifdef JVMTI_TRACE
220 _jvmti_external.functions = TraceJVMTI != NULL ? &jvmtiTrace_Interface : &jvmti_Interface;
221 #else
222 _jvmti_external.functions = &jvmti_Interface;
223 #endif
224 }
225
226
227 void
228 JvmtiEnvBase::dispose() {
229
230 #ifdef JVMTI_TRACE
231 JvmtiTrace::shutdown();
232 #endif
233
234 // Dispose of event info and let the event controller call us back
235 // in a locked state (env_dispose, below)
236 JvmtiEventController::env_dispose(this);
237 }
238
239 void
240 JvmtiEnvBase::env_dispose() {
241 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
242
243 // We have been entered with all events disabled on this environment.
244 // A race to re-enable events (by setting callbacks) is prevented by
245 // checking for a valid environment when setting callbacks (while
246 // holding the JvmtiThreadState_lock).
247
248 // Mark as invalid.
249 _magic = DISPOSED_MAGIC;
250
251 // Relinquish all capabilities.
252 jvmtiCapabilities *caps = get_capabilities();
253 JvmtiManageCapabilities::relinquish_capabilities(caps, caps, caps);
254
255 // Same situation as with events (see above)
256 set_native_method_prefixes(0, NULL);
257
258 JvmtiTagMap* tag_map_to_deallocate = _tag_map;
259 set_tag_map(NULL);
260 // A tag map can be big, deallocate it now
261 if (tag_map_to_deallocate != NULL) {
262 delete tag_map_to_deallocate;
263 }
264
265 _needs_clean_up = true;
266 }
267
268
269 JvmtiEnvBase::~JvmtiEnvBase() {
270 assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
271
272 // There is a small window of time during which the tag map of a
273 // disposed environment could have been reallocated.
274 // Make sure it is gone.
275 JvmtiTagMap* tag_map_to_deallocate = _tag_map;
276 set_tag_map(NULL);
277 // A tag map can be big, deallocate it now
278 if (tag_map_to_deallocate != NULL) {
279 delete tag_map_to_deallocate;
280 }
281
282 _magic = BAD_MAGIC;
283 }
284
285
286 void
287 JvmtiEnvBase::periodic_clean_up() {
288 assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
289
290 // JvmtiEnvBase reference is saved in JvmtiEnvThreadState. So
291 // clean up JvmtiThreadState before deleting JvmtiEnv pointer.
292 JvmtiThreadState::periodic_clean_up();
293
294 // Unlink all invalid environments from the list of environments
295 // and deallocate them
296 JvmtiEnvIterator it;
297 JvmtiEnvBase* previous_env = NULL;
298 JvmtiEnvBase* env = it.first();
299 while (env != NULL) {
300 if (env->is_valid()) {
301 previous_env = env;
302 env = it.next(env);
303 } else {
304 // This one isn't valid, remove it from the list and deallocate it
305 JvmtiEnvBase* defunct_env = env;
306 env = it.next(env);
307 if (previous_env == NULL) {
308 _head_environment = env;
309 } else {
310 previous_env->set_next_environment(env);
311 }
312 delete defunct_env;
313 }
314 }
315
316 }
317
318
319 void
320 JvmtiEnvBase::check_for_periodic_clean_up() {
321 assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
322
323 class ThreadInsideIterationClosure: public ThreadClosure {
324 private:
325 bool _inside;
326 public:
327 ThreadInsideIterationClosure() : _inside(false) {};
328
329 void do_thread(Thread* thread) {
330 _inside |= thread->is_inside_jvmti_env_iteration();
331 }
332
333 bool is_inside_jvmti_env_iteration() {
334 return _inside;
335 }
336 };
337
338 if (_needs_clean_up) {
339 // Check if we are currently iterating environment,
340 // deallocation should not occur if we are
341 ThreadInsideIterationClosure tiic;
342 Threads::threads_do(&tiic);
343 if (!tiic.is_inside_jvmti_env_iteration() &&
344 !is_inside_dying_thread_env_iteration()) {
345 _needs_clean_up = false;
346 JvmtiEnvBase::periodic_clean_up();
347 }
348 }
349 }
350
351
352 void
353 JvmtiEnvBase::record_first_time_class_file_load_hook_enabled() {
354 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(),
355 "sanity check");
356
357 if (!_class_file_load_hook_ever_enabled) {
358 _class_file_load_hook_ever_enabled = true;
359
360 if (get_capabilities()->can_retransform_classes) {
361 _is_retransformable = true;
362 } else {
363 _is_retransformable = false;
364
365 // cannot add retransform capability after ClassFileLoadHook has been enabled
366 get_prohibited_capabilities()->can_retransform_classes = 1;
367 }
368 }
369 }
370
371
372 void
373 JvmtiEnvBase::record_class_file_load_hook_enabled() {
374 if (!_class_file_load_hook_ever_enabled) {
375 if (Threads::number_of_threads() == 0) {
376 record_first_time_class_file_load_hook_enabled();
377 } else {
378 MutexLocker mu(JvmtiThreadState_lock);
379 record_first_time_class_file_load_hook_enabled();
380 }
381 }
382 }
383
384
385 jvmtiError
386 JvmtiEnvBase::set_native_method_prefixes(jint prefix_count, char** prefixes) {
387 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(),
388 "sanity check");
389
390 int old_prefix_count = get_native_method_prefix_count();
391 char **old_prefixes = get_native_method_prefixes();
392
393 // allocate and install the new prefixex
394 if (prefix_count == 0 || !is_valid()) {
395 _native_method_prefix_count = 0;
396 _native_method_prefixes = NULL;
397 } else {
398 // there are prefixes, allocate an array to hold them, and fill it
399 char** new_prefixes = (char**)os::malloc((prefix_count) * sizeof(char*), mtInternal);
400 if (new_prefixes == NULL) {
401 return JVMTI_ERROR_OUT_OF_MEMORY;
402 }
403 for (int i = 0; i < prefix_count; i++) {
404 char* prefix = prefixes[i];
405 if (prefix == NULL) {
406 for (int j = 0; j < (i-1); j++) {
407 os::free(new_prefixes[j]);
408 }
409 os::free(new_prefixes);
410 return JVMTI_ERROR_NULL_POINTER;
411 }
412 prefix = os::strdup(prefixes[i]);
413 if (prefix == NULL) {
414 for (int j = 0; j < (i-1); j++) {
415 os::free(new_prefixes[j]);
416 }
417 os::free(new_prefixes);
418 return JVMTI_ERROR_OUT_OF_MEMORY;
419 }
420 new_prefixes[i] = prefix;
421 }
422 _native_method_prefix_count = prefix_count;
423 _native_method_prefixes = new_prefixes;
424 }
425
426 // now that we know the new prefixes have been successfully installed we can
427 // safely remove the old ones
428 if (old_prefix_count != 0) {
429 for (int i = 0; i < old_prefix_count; i++) {
430 os::free(old_prefixes[i]);
431 }
432 os::free(old_prefixes);
433 }
434
435 return JVMTI_ERROR_NONE;
436 }
437
438
439 // Collect all the prefixes which have been set in any JVM TI environments
440 // by the SetNativeMethodPrefix(es) functions. Be sure to maintain the
441 // order of environments and the order of prefixes within each environment.
442 // Return in a resource allocated array.
443 char**
444 JvmtiEnvBase::get_all_native_method_prefixes(int* count_ptr) {
445 assert(Threads::number_of_threads() == 0 ||
446 SafepointSynchronize::is_at_safepoint() ||
447 JvmtiThreadState_lock->is_locked(),
448 "sanity check");
449
450 int total_count = 0;
451 GrowableArray<char*>* prefix_array =new GrowableArray<char*>(5);
452
453 JvmtiEnvIterator it;
454 for (JvmtiEnvBase* env = it.first(); env != NULL; env = it.next(env)) {
455 int prefix_count = env->get_native_method_prefix_count();
456 char** prefixes = env->get_native_method_prefixes();
457 for (int j = 0; j < prefix_count; j++) {
458 // retrieve a prefix and so that it is safe against asynchronous changes
459 // copy it into the resource area
460 char* prefix = prefixes[j];
461 char* prefix_copy = NEW_RESOURCE_ARRAY(char, strlen(prefix)+1);
462 strcpy(prefix_copy, prefix);
463 prefix_array->at_put_grow(total_count++, prefix_copy);
464 }
465 }
466
467 char** all_prefixes = NEW_RESOURCE_ARRAY(char*, total_count);
468 char** p = all_prefixes;
469 for (int i = 0; i < total_count; ++i) {
470 *p++ = prefix_array->at(i);
471 }
472 *count_ptr = total_count;
473 return all_prefixes;
474 }
475
476 void
477 JvmtiEnvBase::set_event_callbacks(const jvmtiEventCallbacks* callbacks,
478 jint size_of_callbacks) {
479 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
480
481 size_t byte_cnt = sizeof(jvmtiEventCallbacks);
482
483 // clear in either case to be sure we got any gap between sizes
484 memset(&_event_callbacks, 0, byte_cnt);
485
486 // Now that JvmtiThreadState_lock is held, prevent a possible race condition where events
487 // are re-enabled by a call to set event callbacks where the DisposeEnvironment
488 // occurs after the boiler-plate environment check and before the lock is acquired.
489 if (callbacks != NULL && is_valid()) {
490 if (size_of_callbacks < (jint)byte_cnt) {
491 byte_cnt = size_of_callbacks;
492 }
493 memcpy(&_event_callbacks, callbacks, byte_cnt);
494 }
495 }
496
497
498 // In the fullness of time, all users of the method should instead
499 // directly use allocate, besides being cleaner and faster, this will
500 // mean much better out of memory handling
501 unsigned char *
502 JvmtiEnvBase::jvmtiMalloc(jlong size) {
503 unsigned char* mem = NULL;
504 jvmtiError result = allocate(size, &mem);
505 assert(result == JVMTI_ERROR_NONE, "Allocate failed");
506 return mem;
507 }
508
509
510 // Handle management
511
512 jobject JvmtiEnvBase::jni_reference(Handle hndl) {
513 return JNIHandles::make_local(hndl());
514 }
515
516 jobject JvmtiEnvBase::jni_reference(JavaThread *thread, Handle hndl) {
517 return JNIHandles::make_local(thread, hndl());
518 }
519
520 void JvmtiEnvBase::destroy_jni_reference(jobject jobj) {
521 JNIHandles::destroy_local(jobj);
522 }
523
524 void JvmtiEnvBase::destroy_jni_reference(JavaThread *thread, jobject jobj) {
525 JNIHandles::destroy_local(jobj); // thread is unused.
526 }
527
528 //
529 // Threads
530 //
531
532 jobject *
533 JvmtiEnvBase::new_jobjectArray(int length, Handle *handles) {
534 if (length == 0) {
535 return NULL;
536 }
537
538 jobject *objArray = (jobject *) jvmtiMalloc(sizeof(jobject) * length);
539 NULL_CHECK(objArray, NULL);
540
541 for (int i=0; i<length; i++) {
542 objArray[i] = jni_reference(handles[i]);
543 }
544 return objArray;
545 }
546
547 jthread *
548 JvmtiEnvBase::new_jthreadArray(int length, Handle *handles) {
549 return (jthread *) new_jobjectArray(length,handles);
550 }
551
552 jthreadGroup *
553 JvmtiEnvBase::new_jthreadGroupArray(int length, Handle *handles) {
554 return (jthreadGroup *) new_jobjectArray(length,handles);
555 }
556
557 // return the vframe on the specified thread and depth, NULL if no such frame
558 vframe*
559 JvmtiEnvBase::vframeFor(JavaThread* java_thread, jint depth) {
560 if (!java_thread->has_last_Java_frame()) {
561 return NULL;
562 }
563 RegisterMap reg_map(java_thread);
564 vframe *vf = java_thread->last_java_vframe(®_map);
565 int d = 0;
566 while ((vf != NULL) && (d < depth)) {
567 vf = vf->java_sender();
568 d++;
569 }
570 return vf;
571 }
572
573
574 //
575 // utilities: JNI objects
576 //
577
578
579 jclass
580 JvmtiEnvBase::get_jni_class_non_null(Klass* k) {
581 assert(k != NULL, "k != NULL");
582 Thread *thread = Thread::current();
583 return (jclass)jni_reference(Handle(thread, k->java_mirror()));
584 }
585
586 //
587 // Field Information
588 //
589
590 bool
591 JvmtiEnvBase::get_field_descriptor(Klass* k, jfieldID field, fieldDescriptor* fd) {
592 if (!jfieldIDWorkaround::is_valid_jfieldID(k, field)) {
593 return false;
594 }
595 bool found = false;
596 if (jfieldIDWorkaround::is_static_jfieldID(field)) {
597 JNIid* id = jfieldIDWorkaround::from_static_jfieldID(field);
598 found = id->find_local_field(fd);
599 } else {
600 // Non-static field. The fieldID is really the offset of the field within the object.
601 int offset = jfieldIDWorkaround::from_instance_jfieldID(k, field);
602 found = InstanceKlass::cast(k)->find_field_from_offset(offset, false, fd);
603 }
604 return found;
605 }
606
607 //
608 // Object Monitor Information
609 //
610
611 //
612 // Count the number of objects for a lightweight monitor. The hobj
613 // parameter is object that owns the monitor so this routine will
614 // count the number of times the same object was locked by frames
615 // in java_thread.
616 //
617 jint
618 JvmtiEnvBase::count_locked_objects(JavaThread *java_thread, Handle hobj) {
619 jint ret = 0;
620 if (!java_thread->has_last_Java_frame()) {
621 return ret; // no Java frames so no monitors
622 }
623
624 ResourceMark rm;
625 HandleMark hm;
626 RegisterMap reg_map(java_thread);
627
628 for(javaVFrame *jvf=java_thread->last_java_vframe(®_map); jvf != NULL;
629 jvf = jvf->java_sender()) {
630 GrowableArray<MonitorInfo*>* mons = jvf->monitors();
631 if (!mons->is_empty()) {
632 for (int i = 0; i < mons->length(); i++) {
633 MonitorInfo *mi = mons->at(i);
634 if (mi->owner_is_scalar_replaced()) continue;
635
636 // see if owner of the monitor is our object
637 if (mi->owner() != NULL && mi->owner() == hobj()) {
638 ret++;
639 }
640 }
641 }
642 }
643 return ret;
644 }
645
646
647
648 jvmtiError
649 JvmtiEnvBase::get_current_contended_monitor(JavaThread *calling_thread, JavaThread *java_thread, jobject *monitor_ptr) {
650 #ifdef ASSERT
651 uint32_t debug_bits = 0;
652 #endif
653 assert((SafepointSynchronize::is_at_safepoint() ||
654 java_thread->is_thread_fully_suspended(false, &debug_bits)),
655 "at safepoint or target thread is suspended");
656 oop obj = NULL;
657 ObjectMonitor *mon = java_thread->current_waiting_monitor();
658 if (mon == NULL) {
659 // thread is not doing an Object.wait() call
660 mon = java_thread->current_pending_monitor();
661 if (mon != NULL) {
662 // The thread is trying to enter() an ObjectMonitor.
663 obj = (oop)mon->object();
664 assert(obj != NULL, "ObjectMonitor should have a valid object!");
665 }
666 // implied else: no contended ObjectMonitor
667 } else {
668 // thread is doing an Object.wait() call
669 obj = (oop)mon->object();
670 assert(obj != NULL, "Object.wait() should have an object");
671 }
672
673 if (obj == NULL) {
674 *monitor_ptr = NULL;
675 } else {
676 HandleMark hm;
677 Handle hobj(Thread::current(), obj);
678 *monitor_ptr = jni_reference(calling_thread, hobj);
679 }
680 return JVMTI_ERROR_NONE;
681 }
682
683
684 jvmtiError
685 JvmtiEnvBase::get_owned_monitors(JavaThread *calling_thread, JavaThread* java_thread,
686 GrowableArray<jvmtiMonitorStackDepthInfo*> *owned_monitors_list) {
687 jvmtiError err = JVMTI_ERROR_NONE;
688 #ifdef ASSERT
689 uint32_t debug_bits = 0;
690 #endif
691 assert((SafepointSynchronize::is_at_safepoint() ||
692 java_thread->is_thread_fully_suspended(false, &debug_bits)),
693 "at safepoint or target thread is suspended");
694
695 if (java_thread->has_last_Java_frame()) {
696 ResourceMark rm;
697 HandleMark hm;
698 RegisterMap reg_map(java_thread);
699
700 int depth = 0;
701 for (javaVFrame *jvf = java_thread->last_java_vframe(®_map); jvf != NULL;
702 jvf = jvf->java_sender()) {
703 if (MaxJavaStackTraceDepth == 0 || depth++ < MaxJavaStackTraceDepth) { // check for stack too deep
704 // add locked objects for this frame into list
705 err = get_locked_objects_in_frame(calling_thread, java_thread, jvf, owned_monitors_list, depth-1);
706 if (err != JVMTI_ERROR_NONE) {
707 return err;
708 }
709 }
710 }
711 }
712
713 // Get off stack monitors. (e.g. acquired via jni MonitorEnter).
714 JvmtiMonitorClosure jmc(java_thread, calling_thread, owned_monitors_list, this);
715 ObjectSynchronizer::monitors_iterate(&jmc);
716 err = jmc.error();
717
718 return err;
719 }
720
721 // Save JNI local handles for any objects that this frame owns.
722 jvmtiError
723 JvmtiEnvBase::get_locked_objects_in_frame(JavaThread* calling_thread, JavaThread* java_thread,
724 javaVFrame *jvf, GrowableArray<jvmtiMonitorStackDepthInfo*>* owned_monitors_list, jint stack_depth) {
725 jvmtiError err = JVMTI_ERROR_NONE;
726 ResourceMark rm;
727
728 GrowableArray<MonitorInfo*>* mons = jvf->monitors();
729 if (mons->is_empty()) {
730 return err; // this javaVFrame holds no monitors
731 }
732
733 HandleMark hm;
734 oop wait_obj = NULL;
735 {
736 // save object of current wait() call (if any) for later comparison
737 ObjectMonitor *mon = java_thread->current_waiting_monitor();
738 if (mon != NULL) {
739 wait_obj = (oop)mon->object();
740 }
741 }
742 oop pending_obj = NULL;
743 {
744 // save object of current enter() call (if any) for later comparison
745 ObjectMonitor *mon = java_thread->current_pending_monitor();
746 if (mon != NULL) {
747 pending_obj = (oop)mon->object();
748 }
749 }
750
751 for (int i = 0; i < mons->length(); i++) {
752 MonitorInfo *mi = mons->at(i);
753
754 if (mi->owner_is_scalar_replaced()) continue;
755
756 oop obj = mi->owner();
757 if (obj == NULL) {
758 // this monitor doesn't have an owning object so skip it
759 continue;
760 }
761
762 if (wait_obj == obj) {
763 // the thread is waiting on this monitor so it isn't really owned
764 continue;
765 }
766
767 if (pending_obj == obj) {
768 // the thread is pending on this monitor so it isn't really owned
769 continue;
770 }
771
772 if (owned_monitors_list->length() > 0) {
773 // Our list has at least one object on it so we have to check
774 // for recursive object locking
775 bool found = false;
776 for (int j = 0; j < owned_monitors_list->length(); j++) {
777 jobject jobj = ((jvmtiMonitorStackDepthInfo*)owned_monitors_list->at(j))->monitor;
778 oop check = JNIHandles::resolve(jobj);
779 if (check == obj) {
780 found = true; // we found the object
781 break;
782 }
783 }
784
785 if (found) {
786 // already have this object so don't include it
787 continue;
788 }
789 }
790
791 // add the owning object to our list
792 jvmtiMonitorStackDepthInfo *jmsdi;
793 err = allocate(sizeof(jvmtiMonitorStackDepthInfo), (unsigned char **)&jmsdi);
794 if (err != JVMTI_ERROR_NONE) {
795 return err;
796 }
797 Handle hobj(Thread::current(), obj);
798 jmsdi->monitor = jni_reference(calling_thread, hobj);
799 jmsdi->stack_depth = stack_depth;
800 owned_monitors_list->append(jmsdi);
801 }
802
803 return err;
804 }
805
806 jvmtiError
807 JvmtiEnvBase::get_stack_trace(JavaThread *java_thread,
808 jint start_depth, jint max_count,
809 jvmtiFrameInfo* frame_buffer, jint* count_ptr) {
810 #ifdef ASSERT
811 uint32_t debug_bits = 0;
812 #endif
813 assert((SafepointSynchronize::is_at_safepoint() ||
814 java_thread->is_thread_fully_suspended(false, &debug_bits)),
815 "at safepoint or target thread is suspended");
816 int count = 0;
817 if (java_thread->has_last_Java_frame()) {
818 RegisterMap reg_map(java_thread);
819 Thread* current_thread = Thread::current();
820 ResourceMark rm(current_thread);
821 javaVFrame *jvf = java_thread->last_java_vframe(®_map);
822 HandleMark hm(current_thread);
823 if (start_depth != 0) {
824 if (start_depth > 0) {
825 for (int j = 0; j < start_depth && jvf != NULL; j++) {
826 jvf = jvf->java_sender();
827 }
828 if (jvf == NULL) {
829 // start_depth is deeper than the stack depth
830 return JVMTI_ERROR_ILLEGAL_ARGUMENT;
831 }
832 } else { // start_depth < 0
833 // we are referencing the starting depth based on the oldest
834 // part of the stack.
835 // optimize to limit the number of times that java_sender() is called
836 javaVFrame *jvf_cursor = jvf;
837 javaVFrame *jvf_prev = NULL;
838 javaVFrame *jvf_prev_prev = NULL;
839 int j = 0;
840 while (jvf_cursor != NULL) {
841 jvf_prev_prev = jvf_prev;
842 jvf_prev = jvf_cursor;
843 for (j = 0; j > start_depth && jvf_cursor != NULL; j--) {
844 jvf_cursor = jvf_cursor->java_sender();
845 }
846 }
847 if (j == start_depth) {
848 // previous pointer is exactly where we want to start
849 jvf = jvf_prev;
850 } else {
851 // we need to back up further to get to the right place
852 if (jvf_prev_prev == NULL) {
853 // the -start_depth is greater than the stack depth
854 return JVMTI_ERROR_ILLEGAL_ARGUMENT;
855 }
856 // j now is the number of frames on the stack starting with
857 // jvf_prev, we start from jvf_prev_prev and move older on
858 // the stack that many, the result is -start_depth frames
859 // remaining.
860 jvf = jvf_prev_prev;
861 for (; j < 0; j++) {
862 jvf = jvf->java_sender();
863 }
864 }
865 }
866 }
867 for (; count < max_count && jvf != NULL; count++) {
868 frame_buffer[count].method = jvf->method()->jmethod_id();
869 frame_buffer[count].location = (jvf->method()->is_native() ? -1 : jvf->bci());
870 jvf = jvf->java_sender();
871 }
872 } else {
873 if (start_depth != 0) {
874 // no frames and there is a starting depth
875 return JVMTI_ERROR_ILLEGAL_ARGUMENT;
876 }
877 }
878 *count_ptr = count;
879 return JVMTI_ERROR_NONE;
880 }
881
882 jvmtiError
883 JvmtiEnvBase::get_frame_count(JvmtiThreadState *state, jint *count_ptr) {
884 assert((state != NULL),
885 "JavaThread should create JvmtiThreadState before calling this method");
886 *count_ptr = state->count_frames();
887 return JVMTI_ERROR_NONE;
888 }
889
890 jvmtiError
891 JvmtiEnvBase::get_frame_location(JavaThread *java_thread, jint depth,
892 jmethodID* method_ptr, jlocation* location_ptr) {
893 #ifdef ASSERT
894 uint32_t debug_bits = 0;
895 #endif
896 assert((SafepointSynchronize::is_at_safepoint() ||
897 java_thread->is_thread_fully_suspended(false, &debug_bits)),
898 "at safepoint or target thread is suspended");
899 Thread* current_thread = Thread::current();
900 ResourceMark rm(current_thread);
901
902 vframe *vf = vframeFor(java_thread, depth);
903 if (vf == NULL) {
904 return JVMTI_ERROR_NO_MORE_FRAMES;
905 }
906
907 // vframeFor should return a java frame. If it doesn't
908 // it means we've got an internal error and we return the
909 // error in product mode. In debug mode we will instead
910 // attempt to cast the vframe to a javaVFrame and will
911 // cause an assertion/crash to allow further diagnosis.
912 #ifdef PRODUCT
913 if (!vf->is_java_frame()) {
914 return JVMTI_ERROR_INTERNAL;
915 }
916 #endif
917
918 HandleMark hm(current_thread);
919 javaVFrame *jvf = javaVFrame::cast(vf);
920 Method* method = jvf->method();
921 if (method->is_native()) {
922 *location_ptr = -1;
923 } else {
924 *location_ptr = jvf->bci();
925 }
926 *method_ptr = method->jmethod_id();
927
928 return JVMTI_ERROR_NONE;
929 }
930
931
932 jvmtiError
933 JvmtiEnvBase::get_object_monitor_usage(JavaThread* calling_thread, jobject object, jvmtiMonitorUsage* info_ptr) {
934 HandleMark hm;
935 Handle hobj;
936
937 Thread* current_thread = Thread::current();
938 bool at_safepoint = SafepointSynchronize::is_at_safepoint();
939
940 // Check arguments
941 {
942 oop mirror = JNIHandles::resolve_external_guard(object);
943 NULL_CHECK(mirror, JVMTI_ERROR_INVALID_OBJECT);
944 NULL_CHECK(info_ptr, JVMTI_ERROR_NULL_POINTER);
945
946 hobj = Handle(current_thread, mirror);
947 }
948
949 JavaThread *owning_thread = NULL;
950 ObjectMonitor *mon = NULL;
951 jvmtiMonitorUsage ret = {
952 NULL, 0, 0, NULL, 0, NULL
953 };
954
955 uint32_t debug_bits = 0;
956 // first derive the object's owner and entry_count (if any)
957 {
958 // Revoke any biases before querying the mark word
959 if (at_safepoint) {
960 BiasedLocking::revoke_at_safepoint(hobj);
961 } else {
962 BiasedLocking::revoke(hobj, calling_thread);
963 }
964
965 address owner = NULL;
966 {
967 markWord mark = hobj()->mark();
968
969 if (!mark.has_monitor()) {
970 // this object has a lightweight monitor
971
972 if (mark.has_locker()) {
973 owner = (address)mark.locker(); // save the address of the Lock word
974 }
975 // implied else: no owner
976 } else {
977 // this object has a heavyweight monitor
978 mon = mark.monitor();
979
980 // The owner field of a heavyweight monitor may be NULL for no
981 // owner, a JavaThread * or it may still be the address of the
982 // Lock word in a JavaThread's stack. A monitor can be inflated
983 // by a non-owning JavaThread, but only the owning JavaThread
984 // can change the owner field from the Lock word to the
985 // JavaThread * and it may not have done that yet.
986 owner = (address)mon->owner();
987 }
988 }
989
990 if (owner != NULL) {
991 // Use current thread since function can be called from a
992 // JavaThread or the VMThread.
993 ThreadsListHandle tlh;
994 // This monitor is owned so we have to find the owning JavaThread.
995 owning_thread = Threads::owning_thread_from_monitor_owner(tlh.list(), owner);
996 // Cannot assume (owning_thread != NULL) here because this function
997 // may not have been called at a safepoint and the owning_thread
998 // might not be suspended.
999 if (owning_thread != NULL) {
1000 // The monitor's owner either has to be the current thread, at safepoint
1001 // or it has to be suspended. Any of these conditions will prevent both
1002 // contending and waiting threads from modifying the state of
1003 // the monitor.
1004 if (!at_safepoint && !owning_thread->is_thread_fully_suspended(true, &debug_bits)) {
1005 // Don't worry! This return of JVMTI_ERROR_THREAD_NOT_SUSPENDED
1006 // will not make it back to the JVM/TI agent. The error code will
1007 // get intercepted in JvmtiEnv::GetObjectMonitorUsage() which
1008 // will retry the call via a VM_GetObjectMonitorUsage VM op.
1009 return JVMTI_ERROR_THREAD_NOT_SUSPENDED;
1010 }
1011 HandleMark hm;
1012 Handle th(current_thread, owning_thread->threadObj());
1013 ret.owner = (jthread)jni_reference(calling_thread, th);
1014 }
1015 // implied else: no owner
1016 } // ThreadsListHandle is destroyed here.
1017
1018 if (owning_thread != NULL) { // monitor is owned
1019 // The recursions field of a monitor does not reflect recursions
1020 // as lightweight locks before inflating the monitor are not included.
1021 // We have to count the number of recursive monitor entries the hard way.
1022 // We pass a handle to survive any GCs along the way.
1023 ResourceMark rm;
1024 ret.entry_count = count_locked_objects(owning_thread, hobj);
1025 }
1026 // implied else: entry_count == 0
1027 }
1028
1029 jint nWant = 0, nWait = 0;
1030 if (mon != NULL) {
1031 // this object has a heavyweight monitor
1032 nWant = mon->contentions(); // # of threads contending for monitor
1033 nWait = mon->waiters(); // # of threads in Object.wait()
1034 ret.waiter_count = nWant + nWait;
1035 ret.notify_waiter_count = nWait;
1036 } else {
1037 // this object has a lightweight monitor
1038 ret.waiter_count = 0;
1039 ret.notify_waiter_count = 0;
1040 }
1041
1042 // Allocate memory for heavyweight and lightweight monitor.
1043 jvmtiError err;
1044 err = allocate(ret.waiter_count * sizeof(jthread *), (unsigned char**)&ret.waiters);
1045 if (err != JVMTI_ERROR_NONE) {
1046 return err;
1047 }
1048 err = allocate(ret.notify_waiter_count * sizeof(jthread *),
1049 (unsigned char**)&ret.notify_waiters);
1050 if (err != JVMTI_ERROR_NONE) {
1051 deallocate((unsigned char*)ret.waiters);
1052 return err;
1053 }
1054
1055 // now derive the rest of the fields
1056 if (mon != NULL) {
1057 // this object has a heavyweight monitor
1058
1059 // Number of waiters may actually be less than the waiter count.
1060 // So NULL out memory so that unused memory will be NULL.
1061 memset(ret.waiters, 0, ret.waiter_count * sizeof(jthread *));
1062 memset(ret.notify_waiters, 0, ret.notify_waiter_count * sizeof(jthread *));
1063
1064 if (ret.waiter_count > 0) {
1065 // we have contending and/or waiting threads
1066 HandleMark hm;
1067 // Use current thread since function can be called from a
1068 // JavaThread or the VMThread.
1069 ThreadsListHandle tlh;
1070 if (nWant > 0) {
1071 // we have contending threads
1072 ResourceMark rm;
1073 // get_pending_threads returns only java thread so we do not need to
1074 // check for non java threads.
1075 GrowableArray<JavaThread*>* wantList = Threads::get_pending_threads(tlh.list(), nWant, (address)mon);
1076 if (wantList->length() < nWant) {
1077 // robustness: the pending list has gotten smaller
1078 nWant = wantList->length();
1079 }
1080 for (int i = 0; i < nWant; i++) {
1081 JavaThread *pending_thread = wantList->at(i);
1082 // If the monitor has no owner, then a non-suspended contending
1083 // thread could potentially change the state of the monitor by
1084 // entering it. The JVM/TI spec doesn't allow this.
1085 if (owning_thread == NULL && !at_safepoint &&
1086 !pending_thread->is_thread_fully_suspended(true, &debug_bits)) {
1087 if (ret.owner != NULL) {
1088 destroy_jni_reference(calling_thread, ret.owner);
1089 }
1090 for (int j = 0; j < i; j++) {
1091 destroy_jni_reference(calling_thread, ret.waiters[j]);
1092 }
1093 deallocate((unsigned char*)ret.waiters);
1094 deallocate((unsigned char*)ret.notify_waiters);
1095 return JVMTI_ERROR_THREAD_NOT_SUSPENDED;
1096 }
1097 Handle th(current_thread, pending_thread->threadObj());
1098 ret.waiters[i] = (jthread)jni_reference(calling_thread, th);
1099 }
1100 }
1101 if (nWait > 0) {
1102 // we have threads in Object.wait()
1103 int offset = nWant; // add after any contending threads
1104 ObjectWaiter *waiter = mon->first_waiter();
1105 for (int i = 0, j = 0; i < nWait; i++) {
1106 if (waiter == NULL) {
1107 // robustness: the waiting list has gotten smaller
1108 nWait = j;
1109 break;
1110 }
1111 Thread *t = mon->thread_of_waiter(waiter);
1112 if (t != NULL && t->is_Java_thread()) {
1113 JavaThread *wjava_thread = (JavaThread *)t;
1114 // If the thread was found on the ObjectWaiter list, then
1115 // it has not been notified. This thread can't change the
1116 // state of the monitor so it doesn't need to be suspended.
1117 Handle th(current_thread, wjava_thread->threadObj());
1118 ret.waiters[offset + j] = (jthread)jni_reference(calling_thread, th);
1119 ret.notify_waiters[j++] = (jthread)jni_reference(calling_thread, th);
1120 }
1121 waiter = mon->next_waiter(waiter);
1122 }
1123 }
1124 } // ThreadsListHandle is destroyed here.
1125
1126 // Adjust count. nWant and nWait count values may be less than original.
1127 ret.waiter_count = nWant + nWait;
1128 ret.notify_waiter_count = nWait;
1129 } else {
1130 // this object has a lightweight monitor and we have nothing more
1131 // to do here because the defaults are just fine.
1132 }
1133
1134 // we don't update return parameter unless everything worked
1135 *info_ptr = ret;
1136
1137 return JVMTI_ERROR_NONE;
1138 }
1139
1140 ResourceTracker::ResourceTracker(JvmtiEnv* env) {
1141 _env = env;
1142 _allocations = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<unsigned char*>(20, true);
1143 _failed = false;
1144 }
1145 ResourceTracker::~ResourceTracker() {
1146 if (_failed) {
1147 for (int i=0; i<_allocations->length(); i++) {
1148 _env->deallocate(_allocations->at(i));
1149 }
1150 }
1151 delete _allocations;
1152 }
1153
1154 jvmtiError ResourceTracker::allocate(jlong size, unsigned char** mem_ptr) {
1155 unsigned char *ptr;
1156 jvmtiError err = _env->allocate(size, &ptr);
1157 if (err == JVMTI_ERROR_NONE) {
1158 _allocations->append(ptr);
1159 *mem_ptr = ptr;
1160 } else {
1161 *mem_ptr = NULL;
1162 _failed = true;
1163 }
1164 return err;
1165 }
1166
1167 unsigned char* ResourceTracker::allocate(jlong size) {
1168 unsigned char* ptr;
1169 allocate(size, &ptr);
1170 return ptr;
1171 }
1172
1173 char* ResourceTracker::strdup(const char* str) {
1174 char *dup_str = (char*)allocate(strlen(str)+1);
1175 if (dup_str != NULL) {
1176 strcpy(dup_str, str);
1177 }
1178 return dup_str;
1179 }
1180
1181 struct StackInfoNode {
1182 struct StackInfoNode *next;
1183 jvmtiStackInfo info;
1184 };
1185
1186 // Create a jvmtiStackInfo inside a linked list node and create a
1187 // buffer for the frame information, both allocated as resource objects.
1188 // Fill in both the jvmtiStackInfo and the jvmtiFrameInfo.
1189 // Note that either or both of thr and thread_oop
1190 // may be null if the thread is new or has exited.
1191 void
1192 VM_GetMultipleStackTraces::fill_frames(jthread jt, JavaThread *thr, oop thread_oop) {
1193 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
1194
1195 jint state = 0;
1196 struct StackInfoNode *node = NEW_RESOURCE_OBJ(struct StackInfoNode);
1197 jvmtiStackInfo *infop = &(node->info);
1198 node->next = head();
1199 set_head(node);
1200 infop->frame_count = 0;
1201 infop->thread = jt;
1202
1203 if (thread_oop != NULL) {
1204 // get most state bits
1205 state = (jint)java_lang_Thread::get_thread_status(thread_oop);
1206 }
1207
1208 if (thr != NULL) { // add more state bits if there is a JavaThead to query
1209 // same as is_being_ext_suspended() but without locking
1210 if (thr->is_ext_suspended() || thr->is_external_suspend()) {
1211 state |= JVMTI_THREAD_STATE_SUSPENDED;
1212 }
1213 JavaThreadState jts = thr->thread_state();
1214 if (jts == _thread_in_native) {
1215 state |= JVMTI_THREAD_STATE_IN_NATIVE;
1216 }
1217 if (thr->is_interrupted(false)) {
1218 state |= JVMTI_THREAD_STATE_INTERRUPTED;
1219 }
1220 }
1221 infop->state = state;
1222
1223 if (thr != NULL && (state & JVMTI_THREAD_STATE_ALIVE) != 0) {
1224 infop->frame_buffer = NEW_RESOURCE_ARRAY(jvmtiFrameInfo, max_frame_count());
1225 env()->get_stack_trace(thr, 0, max_frame_count(),
1226 infop->frame_buffer, &(infop->frame_count));
1227 } else {
1228 infop->frame_buffer = NULL;
1229 infop->frame_count = 0;
1230 }
1231 _frame_count_total += infop->frame_count;
1232 }
1233
1234 // Based on the stack information in the linked list, allocate memory
1235 // block to return and fill it from the info in the linked list.
1236 void
1237 VM_GetMultipleStackTraces::allocate_and_fill_stacks(jint thread_count) {
1238 // do I need to worry about alignment issues?
1239 jlong alloc_size = thread_count * sizeof(jvmtiStackInfo)
1240 + _frame_count_total * sizeof(jvmtiFrameInfo);
1241 env()->allocate(alloc_size, (unsigned char **)&_stack_info);
1242
1243 // pointers to move through the newly allocated space as it is filled in
1244 jvmtiStackInfo *si = _stack_info + thread_count; // bottom of stack info
1245 jvmtiFrameInfo *fi = (jvmtiFrameInfo *)si; // is the top of frame info
1246
1247 // copy information in resource area into allocated buffer
1248 // insert stack info backwards since linked list is backwards
1249 // insert frame info forwards
1250 // walk the StackInfoNodes
1251 for (struct StackInfoNode *sin = head(); sin != NULL; sin = sin->next) {
1252 jint frame_count = sin->info.frame_count;
1253 size_t frames_size = frame_count * sizeof(jvmtiFrameInfo);
1254 --si;
1255 memcpy(si, &(sin->info), sizeof(jvmtiStackInfo));
1256 if (frames_size == 0) {
1257 si->frame_buffer = NULL;
1258 } else {
1259 memcpy(fi, sin->info.frame_buffer, frames_size);
1260 si->frame_buffer = fi; // point to the new allocated copy of the frames
1261 fi += frame_count;
1262 }
1263 }
1264 assert(si == _stack_info, "the last copied stack info must be the first record");
1265 assert((unsigned char *)fi == ((unsigned char *)_stack_info) + alloc_size,
1266 "the last copied frame info must be the last record");
1267 }
1268
1269
1270 void
1271 VM_GetThreadListStackTraces::doit() {
1272 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
1273
1274 ResourceMark rm;
1275 ThreadsListHandle tlh;
1276 for (int i = 0; i < _thread_count; ++i) {
1277 jthread jt = _thread_list[i];
1278 JavaThread* java_thread = NULL;
1279 oop thread_oop = NULL;
1280 jvmtiError err = JvmtiExport::cv_external_thread_to_JavaThread(tlh.list(), jt, &java_thread, &thread_oop);
1281 if (err != JVMTI_ERROR_NONE) {
1282 // We got an error code so we don't have a JavaThread *, but
1283 // only return an error from here if we didn't get a valid
1284 // thread_oop.
1285 if (thread_oop == NULL) {
1286 set_result(err);
1287 return;
1288 }
1289 // We have a valid thread_oop.
1290 }
1291 fill_frames(jt, java_thread, thread_oop);
1292 }
1293 allocate_and_fill_stacks(_thread_count);
1294 }
1295
1296 void
1297 VM_GetAllStackTraces::doit() {
1298 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
1299
1300 ResourceMark rm;
1301 _final_thread_count = 0;
1302 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *jt = jtiwh.next(); ) {
1303 oop thread_oop = jt->threadObj();
1304 if (thread_oop != NULL &&
1305 !jt->is_exiting() &&
1306 java_lang_Thread::is_alive(thread_oop) &&
1307 !jt->is_hidden_from_external_view()) {
1308 ++_final_thread_count;
1309 // Handle block of the calling thread is used to create local refs.
1310 fill_frames((jthread)JNIHandles::make_local(_calling_thread, thread_oop),
1311 jt, thread_oop);
1312 }
1313 }
1314 allocate_and_fill_stacks(_final_thread_count);
1315 }
1316
1317 // Verifies that the top frame is a java frame in an expected state.
1318 // Deoptimizes frame if needed.
1319 // Checks that the frame method signature matches the return type (tos).
1320 // HandleMark must be defined in the caller only.
1321 // It is to keep a ret_ob_h handle alive after return to the caller.
1322 jvmtiError
1323 JvmtiEnvBase::check_top_frame(JavaThread* current_thread, JavaThread* java_thread,
1324 jvalue value, TosState tos, Handle* ret_ob_h) {
1325 ResourceMark rm(current_thread);
1326
1327 vframe *vf = vframeFor(java_thread, 0);
1328 NULL_CHECK(vf, JVMTI_ERROR_NO_MORE_FRAMES);
1329
1330 javaVFrame *jvf = (javaVFrame*) vf;
1331 if (!vf->is_java_frame() || jvf->method()->is_native()) {
1332 return JVMTI_ERROR_OPAQUE_FRAME;
1333 }
1334
1335 // If the frame is a compiled one, need to deoptimize it.
1336 if (vf->is_compiled_frame()) {
1337 if (!vf->fr().can_be_deoptimized()) {
1338 return JVMTI_ERROR_OPAQUE_FRAME;
1339 }
1340 Deoptimization::deoptimize_frame(java_thread, jvf->fr().id());
1341 }
1342
1343 // Get information about method return type
1344 Symbol* signature = jvf->method()->signature();
1345
1346 ResultTypeFinder rtf(signature);
1347 TosState fr_tos = as_TosState(rtf.type());
1348 if (fr_tos != tos) {
1349 if (tos != itos || (fr_tos != btos && fr_tos != ztos && fr_tos != ctos && fr_tos != stos)) {
1350 return JVMTI_ERROR_TYPE_MISMATCH;
1351 }
1352 }
1353
1354 // Check that the jobject class matches the return type signature.
1355 jobject jobj = value.l;
1356 if (tos == atos && jobj != NULL) { // NULL reference is allowed
1357 Handle ob_h(current_thread, JNIHandles::resolve_external_guard(jobj));
1358 NULL_CHECK(ob_h, JVMTI_ERROR_INVALID_OBJECT);
1359 Klass* ob_k = ob_h()->klass();
1360 NULL_CHECK(ob_k, JVMTI_ERROR_INVALID_OBJECT);
1361
1362 // Method return type signature.
1363 char* ty_sign = 1 + strchr(signature->as_C_string(), JVM_SIGNATURE_ENDFUNC);
1364
1365 if (!VM_GetOrSetLocal::is_assignable(ty_sign, ob_k, current_thread)) {
1366 return JVMTI_ERROR_TYPE_MISMATCH;
1367 }
1368 *ret_ob_h = ob_h;
1369 }
1370 return JVMTI_ERROR_NONE;
1371 } /* end check_top_frame */
1372
1373
1374 // ForceEarlyReturn<type> follows the PopFrame approach in many aspects.
1375 // Main difference is on the last stage in the interpreter.
1376 // The PopFrame stops method execution to continue execution
1377 // from the same method call instruction.
1378 // The ForceEarlyReturn forces return from method so the execution
1379 // continues at the bytecode following the method call.
1380
1381 // Threads_lock NOT held, java_thread not protected by lock
1382 // java_thread - pre-checked
1383
1384 jvmtiError
1385 JvmtiEnvBase::force_early_return(JavaThread* java_thread, jvalue value, TosState tos) {
1386 JavaThread* current_thread = JavaThread::current();
1387 HandleMark hm(current_thread);
1388 uint32_t debug_bits = 0;
1389
1390 // retrieve or create the state
1391 JvmtiThreadState* state = JvmtiThreadState::state_for(java_thread);
1392 if (state == NULL) {
1393 return JVMTI_ERROR_THREAD_NOT_ALIVE;
1394 }
1395
1396 // Check if java_thread is fully suspended
1397 if (!java_thread->is_thread_fully_suspended(true /* wait for suspend completion */, &debug_bits)) {
1398 return JVMTI_ERROR_THREAD_NOT_SUSPENDED;
1399 }
1400
1401 // Check to see if a ForceEarlyReturn was already in progress
1402 if (state->is_earlyret_pending()) {
1403 // Probably possible for JVMTI clients to trigger this, but the
1404 // JPDA backend shouldn't allow this to happen
1405 return JVMTI_ERROR_INTERNAL;
1406 }
1407 {
1408 // The same as for PopFrame. Workaround bug:
1409 // 4812902: popFrame hangs if the method is waiting at a synchronize
1410 // Catch this condition and return an error to avoid hanging.
1411 // Now JVMTI spec allows an implementation to bail out with an opaque
1412 // frame error.
1413 OSThread* osThread = java_thread->osthread();
1414 if (osThread->get_state() == MONITOR_WAIT) {
1415 return JVMTI_ERROR_OPAQUE_FRAME;
1416 }
1417 }
1418 Handle ret_ob_h;
1419 jvmtiError err = check_top_frame(current_thread, java_thread, value, tos, &ret_ob_h);
1420 if (err != JVMTI_ERROR_NONE) {
1421 return err;
1422 }
1423 assert(tos != atos || value.l == NULL || ret_ob_h() != NULL,
1424 "return object oop must not be NULL if jobject is not NULL");
1425
1426 // Update the thread state to reflect that the top frame must be
1427 // forced to return.
1428 // The current frame will be returned later when the suspended
1429 // thread is resumed and right before returning from VM to Java.
1430 // (see call_VM_base() in assembler_<cpu>.cpp).
1431
1432 state->set_earlyret_pending();
1433 state->set_earlyret_oop(ret_ob_h());
1434 state->set_earlyret_value(value, tos);
1435
1436 // Set pending step flag for this early return.
1437 // It is cleared when next step event is posted.
1438 state->set_pending_step_for_earlyret();
1439
1440 return JVMTI_ERROR_NONE;
1441 } /* end force_early_return */
1442
1443 void
1444 JvmtiMonitorClosure::do_monitor(ObjectMonitor* mon) {
1445 if ( _error != JVMTI_ERROR_NONE) {
1446 // Error occurred in previous iteration so no need to add
1447 // to the list.
1448 return;
1449 }
1450 if (mon->owner() == _java_thread ) {
1451 // Filter out on stack monitors collected during stack walk.
1452 oop obj = (oop)mon->object();
1453 bool found = false;
1454 for (int j = 0; j < _owned_monitors_list->length(); j++) {
1455 jobject jobj = ((jvmtiMonitorStackDepthInfo*)_owned_monitors_list->at(j))->monitor;
1456 oop check = JNIHandles::resolve(jobj);
1457 if (check == obj) {
1458 // On stack monitor already collected during the stack walk.
1459 found = true;
1460 break;
1461 }
1462 }
1463 if (found == false) {
1464 // This is off stack monitor (e.g. acquired via jni MonitorEnter).
1465 jvmtiError err;
1466 jvmtiMonitorStackDepthInfo *jmsdi;
1467 err = _env->allocate(sizeof(jvmtiMonitorStackDepthInfo), (unsigned char **)&jmsdi);
1468 if (err != JVMTI_ERROR_NONE) {
1469 _error = err;
1470 return;
1471 }
1472 Handle hobj(Thread::current(), obj);
1473 jmsdi->monitor = _env->jni_reference(_calling_thread, hobj);
1474 // stack depth is unknown for this monitor.
1475 jmsdi->stack_depth = -1;
1476 _owned_monitors_list->append(jmsdi);
1477 }
1478 }
1479 }
1480
1481 GrowableArray<OopHandle>* JvmtiModuleClosure::_tbl = NULL;
1482
1483 void JvmtiModuleClosure::do_module(ModuleEntry* entry) {
1484 assert_locked_or_safepoint(Module_lock);
1485 OopHandle module = entry->module_handle();
1486 guarantee(module.resolve() != NULL, "module object is NULL");
1487 _tbl->push(module);
1488 }
1489
1490 jvmtiError
1491 JvmtiModuleClosure::get_all_modules(JvmtiEnv* env, jint* module_count_ptr, jobject** modules_ptr) {
1492 ResourceMark rm;
1493 MutexLocker mcld(ClassLoaderDataGraph_lock);
1494 MutexLocker ml(Module_lock);
1495
1496 _tbl = new GrowableArray<OopHandle>(77);
1497 if (_tbl == NULL) {
1498 return JVMTI_ERROR_OUT_OF_MEMORY;
1499 }
1500
1501 // Iterate over all the modules loaded to the system.
1502 ClassLoaderDataGraph::modules_do(&do_module);
1503
1504 jint len = _tbl->length();
1505 guarantee(len > 0, "at least one module must be present");
1506
1507 jobject* array = (jobject*)env->jvmtiMalloc((jlong)(len * sizeof(jobject)));
1508 if (array == NULL) {
1509 return JVMTI_ERROR_OUT_OF_MEMORY;
1510 }
1511 for (jint idx = 0; idx < len; idx++) {
1512 array[idx] = JNIHandles::make_local(Thread::current(), _tbl->at(idx).resolve());
1513 }
1514 _tbl = NULL;
1515 *modules_ptr = array;
1516 *module_count_ptr = len;
1517 return JVMTI_ERROR_NONE;
1518 }
1519
1520 void
1521 VM_UpdateForPopTopFrame::doit() {
1522 JavaThread* jt = _state->get_thread();
1523 ThreadsListHandle tlh;
1524 if (jt != NULL && tlh.includes(jt) && !jt->is_exiting() && jt->threadObj() != NULL) {
1525 _state->update_for_pop_top_frame();
1526 } else {
1527 _result = JVMTI_ERROR_THREAD_NOT_ALIVE;
1528 }
1529 }
1530
1531 void
1532 VM_SetFramePop::doit() {
1533 JavaThread* jt = _state->get_thread();
1534 ThreadsListHandle tlh;
1535 if (jt != NULL && tlh.includes(jt) && !jt->is_exiting() && jt->threadObj() != NULL) {
1536 int frame_number = _state->count_frames() - _depth;
1537 _state->env_thread_state((JvmtiEnvBase*)_env)->set_frame_pop(frame_number);
1538 } else {
1539 _result = JVMTI_ERROR_THREAD_NOT_ALIVE;
1540 }
1541 }
1542
1543 void
1544 VM_GetOwnedMonitorInfo::doit() {
1545 _result = JVMTI_ERROR_THREAD_NOT_ALIVE;
1546 ThreadsListHandle tlh;
1547 if (_java_thread != NULL && tlh.includes(_java_thread)
1548 && !_java_thread->is_exiting() && _java_thread->threadObj() != NULL) {
1549 _result = ((JvmtiEnvBase *)_env)->get_owned_monitors(_calling_thread, _java_thread,
1550 _owned_monitors_list);
1551 }
1552 }
1553
1554 void
1555 VM_GetCurrentContendedMonitor::doit() {
1556 _result = JVMTI_ERROR_THREAD_NOT_ALIVE;
1557 ThreadsListHandle tlh;
1558 if (_java_thread != NULL && tlh.includes(_java_thread)
1559 && !_java_thread->is_exiting() && _java_thread->threadObj() != NULL) {
1560 _result = ((JvmtiEnvBase *)_env)->get_current_contended_monitor(_calling_thread,_java_thread,_owned_monitor_ptr);
1561 }
1562 }
1563
1564 void
1565 VM_GetStackTrace::doit() {
1566 _result = JVMTI_ERROR_THREAD_NOT_ALIVE;
1567 ThreadsListHandle tlh;
1568 if (_java_thread != NULL && tlh.includes(_java_thread)
1569 && !_java_thread->is_exiting() && _java_thread->threadObj() != NULL) {
1570 _result = ((JvmtiEnvBase *)_env)->get_stack_trace(_java_thread,
1571 _start_depth, _max_count,
1572 _frame_buffer, _count_ptr);
1573 }
1574 }
1575
1576 void
1577 VM_GetFrameCount::doit() {
1578 _result = JVMTI_ERROR_THREAD_NOT_ALIVE;
1579 JavaThread* jt = _state->get_thread();
1580 ThreadsListHandle tlh;
1581 if (jt != NULL && tlh.includes(jt) && !jt->is_exiting() && jt->threadObj() != NULL) {
1582 _result = ((JvmtiEnvBase*)_env)->get_frame_count(_state, _count_ptr);
1583 }
1584 }
1585
1586 void
1587 VM_GetFrameLocation::doit() {
1588 _result = JVMTI_ERROR_THREAD_NOT_ALIVE;
1589 ThreadsListHandle tlh;
1590 if (_java_thread != NULL && tlh.includes(_java_thread)
1591 && !_java_thread->is_exiting() && _java_thread->threadObj() != NULL) {
1592 _result = ((JvmtiEnvBase*)_env)->get_frame_location(_java_thread, _depth,
1593 _method_ptr, _location_ptr);
1594 }
1595 }