1 /*
2 * Copyright (c) 2003, 2017, 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/systemDictionary.hpp"
27 #include "jvmtifiles/jvmtiEnv.hpp"
28 #include "memory/resourceArea.hpp"
29 #include "oops/objArrayKlass.hpp"
30 #include "oops/objArrayOop.hpp"
31 #include "oops/oop.inline.hpp"
32 #include "prims/jvmtiEnvBase.hpp"
33 #include "prims/jvmtiEventController.inline.hpp"
34 #include "prims/jvmtiExtensions.hpp"
35 #include "prims/jvmtiImpl.hpp"
36 #include "prims/jvmtiManageCapabilities.hpp"
37 #include "prims/jvmtiTagMap.hpp"
38 #include "prims/jvmtiThreadState.inline.hpp"
39 #include "runtime/biasedLocking.hpp"
40 #include "runtime/deoptimization.hpp"
41 #include "runtime/interfaceSupport.hpp"
42 #include "runtime/jfieldIDWorkaround.hpp"
43 #include "runtime/objectMonitor.hpp"
44 #include "runtime/objectMonitor.inline.hpp"
45 #include "runtime/signature.hpp"
46 #include "runtime/thread.inline.hpp"
47 #include "runtime/vframe.hpp"
48 #include "runtime/vframe_hp.hpp"
49 #include "runtime/vmThread.hpp"
50 #include "runtime/vm_operations.hpp"
51
52 ///////////////////////////////////////////////////////////////
53 //
54 // JvmtiEnvBase
55 //
56
57 JvmtiEnvBase* JvmtiEnvBase::_head_environment = NULL;
58
59 bool JvmtiEnvBase::_globally_initialized = false;
60 volatile bool JvmtiEnvBase::_needs_clean_up = false;
61
62 jvmtiPhase JvmtiEnvBase::_phase = JVMTI_PHASE_PRIMORDIAL;
63
64 volatile int JvmtiEnvBase::_dying_thread_env_iteration_count = 0;
65
66 extern jvmtiInterface_1_ jvmti_Interface;
67 extern jvmtiInterface_1_ jvmtiTrace_Interface;
68
69
70 // perform initializations that must occur before any JVMTI environments
71 // are released but which should only be initialized once (no matter
72 // how many environments are created).
73 void
74 JvmtiEnvBase::globally_initialize() {
75 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
76 assert(_globally_initialized == false, "bad call");
77
78 JvmtiManageCapabilities::initialize();
79
80 // register extension functions and events
81 JvmtiExtensions::register_extensions();
82
83 #ifdef JVMTI_TRACE
84 JvmtiTrace::initialize();
85 #endif
86
87 _globally_initialized = true;
88 }
89
90
91 void
92 JvmtiEnvBase::initialize() {
93 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
94
95 // Add this environment to the end of the environment list (order is important)
96 {
97 // This block of code must not contain any safepoints, as list deallocation
98 // (which occurs at a safepoint) cannot occur simultaneously with this list
99 // addition. Note: NoSafepointVerifier cannot, currently, be used before
100 // threads exist.
101 JvmtiEnvIterator it;
102 JvmtiEnvBase *previous_env = NULL;
103 for (JvmtiEnvBase* env = it.first(); env != NULL; env = it.next(env)) {
104 previous_env = env;
105 }
106 if (previous_env == NULL) {
107 _head_environment = this;
108 } else {
109 previous_env->set_next_environment(this);
110 }
111 }
112
113 if (_globally_initialized == false) {
114 globally_initialize();
115 }
116 }
117
118 jvmtiPhase
119 JvmtiEnvBase::phase() {
120 // For the JVMTI environments possessed the can_generate_early_vmstart:
121 // replace JVMTI_PHASE_PRIMORDIAL with JVMTI_PHASE_START
122 if (_phase == JVMTI_PHASE_PRIMORDIAL &&
123 JvmtiExport::early_vmstart_recorded() &&
124 early_vmstart_env()) {
125 return JVMTI_PHASE_START;
126 }
127 return _phase; // Normal case
128 }
129
130 bool
131 JvmtiEnvBase::is_valid() {
132 jint value = 0;
133
134 // This object might not be a JvmtiEnvBase so we can't assume
135 // the _magic field is properly aligned. Get the value in a safe
136 // way and then check against JVMTI_MAGIC.
137
138 switch (sizeof(_magic)) {
139 case 2:
140 value = Bytes::get_native_u2((address)&_magic);
141 break;
142
143 case 4:
144 value = Bytes::get_native_u4((address)&_magic);
145 break;
146
147 case 8:
148 value = Bytes::get_native_u8((address)&_magic);
149 break;
150
151 default:
152 guarantee(false, "_magic field is an unexpected size");
153 }
154
155 return value == JVMTI_MAGIC;
156 }
157
158
159 bool
160 JvmtiEnvBase::use_version_1_0_semantics() {
161 int major, minor, micro;
162
163 JvmtiExport::decode_version_values(_version, &major, &minor, µ);
164 return major == 1 && minor == 0; // micro version doesn't matter here
165 }
166
167
168 bool
169 JvmtiEnvBase::use_version_1_1_semantics() {
170 int major, minor, micro;
171
172 JvmtiExport::decode_version_values(_version, &major, &minor, µ);
173 return major == 1 && minor == 1; // micro version doesn't matter here
174 }
175
176 bool
177 JvmtiEnvBase::use_version_1_2_semantics() {
178 int major, minor, micro;
179
180 JvmtiExport::decode_version_values(_version, &major, &minor, µ);
181 return major == 1 && minor == 2; // micro version doesn't matter here
182 }
183
184
185 JvmtiEnvBase::JvmtiEnvBase(jint version) : _env_event_enable() {
186 _version = version;
187 _env_local_storage = NULL;
188 _tag_map = NULL;
189 _native_method_prefix_count = 0;
190 _native_method_prefixes = NULL;
191 _next = NULL;
192 _class_file_load_hook_ever_enabled = false;
193
194 // Moot since ClassFileLoadHook not yet enabled.
195 // But "true" will give a more predictable ClassFileLoadHook behavior
196 // for environment creation during ClassFileLoadHook.
197 _is_retransformable = true;
198
199 // all callbacks initially NULL
200 memset(&_event_callbacks,0,sizeof(jvmtiEventCallbacks));
201
202 // all capabilities initially off
203 memset(&_current_capabilities, 0, sizeof(_current_capabilities));
204
205 // all prohibited capabilities initially off
206 memset(&_prohibited_capabilities, 0, sizeof(_prohibited_capabilities));
207
208 _magic = JVMTI_MAGIC;
209
210 JvmtiEventController::env_initialize((JvmtiEnv*)this);
211
212 #ifdef JVMTI_TRACE
213 _jvmti_external.functions = TraceJVMTI != NULL ? &jvmtiTrace_Interface : &jvmti_Interface;
214 #else
215 _jvmti_external.functions = &jvmti_Interface;
216 #endif
217 }
218
219
220 void
221 JvmtiEnvBase::dispose() {
222
223 #ifdef JVMTI_TRACE
224 JvmtiTrace::shutdown();
225 #endif
226
227 // Dispose of event info and let the event controller call us back
228 // in a locked state (env_dispose, below)
229 JvmtiEventController::env_dispose(this);
230 }
231
232 void
233 JvmtiEnvBase::env_dispose() {
234 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
235
236 // We have been entered with all events disabled on this environment.
237 // A race to re-enable events (by setting callbacks) is prevented by
238 // checking for a valid environment when setting callbacks (while
239 // holding the JvmtiThreadState_lock).
240
241 // Mark as invalid.
242 _magic = DISPOSED_MAGIC;
243
244 // Relinquish all capabilities.
245 jvmtiCapabilities *caps = get_capabilities();
246 JvmtiManageCapabilities::relinquish_capabilities(caps, caps, caps);
247
248 // Same situation as with events (see above)
249 set_native_method_prefixes(0, NULL);
250
251 JvmtiTagMap* tag_map_to_deallocate = _tag_map;
252 set_tag_map(NULL);
253 // A tag map can be big, deallocate it now
254 if (tag_map_to_deallocate != NULL) {
255 delete tag_map_to_deallocate;
256 }
257
258 _needs_clean_up = true;
259 }
260
261
262 JvmtiEnvBase::~JvmtiEnvBase() {
263 assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
264
265 // There is a small window of time during which the tag map of a
266 // disposed environment could have been reallocated.
267 // Make sure it is gone.
268 JvmtiTagMap* tag_map_to_deallocate = _tag_map;
269 set_tag_map(NULL);
270 // A tag map can be big, deallocate it now
271 if (tag_map_to_deallocate != NULL) {
272 delete tag_map_to_deallocate;
273 }
274
275 _magic = BAD_MAGIC;
276 }
277
278
279 void
280 JvmtiEnvBase::periodic_clean_up() {
281 assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
282
283 // JvmtiEnvBase reference is saved in JvmtiEnvThreadState. So
284 // clean up JvmtiThreadState before deleting JvmtiEnv pointer.
285 JvmtiThreadState::periodic_clean_up();
286
287 // Unlink all invalid environments from the list of environments
288 // and deallocate them
289 JvmtiEnvIterator it;
290 JvmtiEnvBase* previous_env = NULL;
291 JvmtiEnvBase* env = it.first();
292 while (env != NULL) {
293 if (env->is_valid()) {
294 previous_env = env;
295 env = it.next(env);
296 } else {
297 // This one isn't valid, remove it from the list and deallocate it
298 JvmtiEnvBase* defunct_env = env;
299 env = it.next(env);
300 if (previous_env == NULL) {
301 _head_environment = env;
302 } else {
303 previous_env->set_next_environment(env);
304 }
305 delete defunct_env;
306 }
307 }
308
309 }
310
311
312 void
313 JvmtiEnvBase::check_for_periodic_clean_up() {
314 assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
315
316 class ThreadInsideIterationClosure: public ThreadClosure {
317 private:
318 bool _inside;
319 public:
320 ThreadInsideIterationClosure() : _inside(false) {};
321
322 void do_thread(Thread* thread) {
323 _inside |= thread->is_inside_jvmti_env_iteration();
324 }
325
326 bool is_inside_jvmti_env_iteration() {
327 return _inside;
328 }
329 };
330
331 if (_needs_clean_up) {
332 // Check if we are currently iterating environment,
333 // deallocation should not occur if we are
334 ThreadInsideIterationClosure tiic;
335 Threads::threads_do(&tiic);
336 if (!tiic.is_inside_jvmti_env_iteration() &&
337 !is_inside_dying_thread_env_iteration()) {
338 _needs_clean_up = false;
339 JvmtiEnvBase::periodic_clean_up();
340 }
341 }
342 }
343
344
345 void
346 JvmtiEnvBase::record_first_time_class_file_load_hook_enabled() {
347 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(),
348 "sanity check");
349
350 if (!_class_file_load_hook_ever_enabled) {
351 _class_file_load_hook_ever_enabled = true;
352
353 if (get_capabilities()->can_retransform_classes) {
354 _is_retransformable = true;
355 } else {
356 _is_retransformable = false;
357
358 // cannot add retransform capability after ClassFileLoadHook has been enabled
359 get_prohibited_capabilities()->can_retransform_classes = 1;
360 }
361 }
362 }
363
364
365 void
366 JvmtiEnvBase::record_class_file_load_hook_enabled() {
367 if (!_class_file_load_hook_ever_enabled) {
368 if (Threads::number_of_threads() == 0) {
369 record_first_time_class_file_load_hook_enabled();
370 } else {
371 MutexLocker mu(JvmtiThreadState_lock);
372 record_first_time_class_file_load_hook_enabled();
373 }
374 }
375 }
376
377
378 jvmtiError
379 JvmtiEnvBase::set_native_method_prefixes(jint prefix_count, char** prefixes) {
380 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(),
381 "sanity check");
382
383 int old_prefix_count = get_native_method_prefix_count();
384 char **old_prefixes = get_native_method_prefixes();
385
386 // allocate and install the new prefixex
387 if (prefix_count == 0 || !is_valid()) {
388 _native_method_prefix_count = 0;
389 _native_method_prefixes = NULL;
390 } else {
391 // there are prefixes, allocate an array to hold them, and fill it
392 char** new_prefixes = (char**)os::malloc((prefix_count) * sizeof(char*), mtInternal);
393 if (new_prefixes == NULL) {
394 return JVMTI_ERROR_OUT_OF_MEMORY;
395 }
396 for (int i = 0; i < prefix_count; i++) {
397 char* prefix = prefixes[i];
398 if (prefix == NULL) {
399 for (int j = 0; j < (i-1); j++) {
400 os::free(new_prefixes[j]);
401 }
402 os::free(new_prefixes);
403 return JVMTI_ERROR_NULL_POINTER;
404 }
405 prefix = os::strdup(prefixes[i]);
406 if (prefix == NULL) {
407 for (int j = 0; j < (i-1); j++) {
408 os::free(new_prefixes[j]);
409 }
410 os::free(new_prefixes);
411 return JVMTI_ERROR_OUT_OF_MEMORY;
412 }
413 new_prefixes[i] = prefix;
414 }
415 _native_method_prefix_count = prefix_count;
416 _native_method_prefixes = new_prefixes;
417 }
418
419 // now that we know the new prefixes have been successfully installed we can
420 // safely remove the old ones
421 if (old_prefix_count != 0) {
422 for (int i = 0; i < old_prefix_count; i++) {
423 os::free(old_prefixes[i]);
424 }
425 os::free(old_prefixes);
426 }
427
428 return JVMTI_ERROR_NONE;
429 }
430
431
432 // Collect all the prefixes which have been set in any JVM TI environments
433 // by the SetNativeMethodPrefix(es) functions. Be sure to maintain the
434 // order of environments and the order of prefixes within each environment.
435 // Return in a resource allocated array.
436 char**
437 JvmtiEnvBase::get_all_native_method_prefixes(int* count_ptr) {
438 assert(Threads::number_of_threads() == 0 ||
439 SafepointSynchronize::is_at_safepoint() ||
440 JvmtiThreadState_lock->is_locked(),
441 "sanity check");
442
443 int total_count = 0;
444 GrowableArray<char*>* prefix_array =new GrowableArray<char*>(5);
445
446 JvmtiEnvIterator it;
447 for (JvmtiEnvBase* env = it.first(); env != NULL; env = it.next(env)) {
448 int prefix_count = env->get_native_method_prefix_count();
449 char** prefixes = env->get_native_method_prefixes();
450 for (int j = 0; j < prefix_count; j++) {
451 // retrieve a prefix and so that it is safe against asynchronous changes
452 // copy it into the resource area
453 char* prefix = prefixes[j];
454 char* prefix_copy = NEW_RESOURCE_ARRAY(char, strlen(prefix)+1);
455 strcpy(prefix_copy, prefix);
456 prefix_array->at_put_grow(total_count++, prefix_copy);
457 }
458 }
459
460 char** all_prefixes = NEW_RESOURCE_ARRAY(char*, total_count);
461 char** p = all_prefixes;
462 for (int i = 0; i < total_count; ++i) {
463 *p++ = prefix_array->at(i);
464 }
465 *count_ptr = total_count;
466 return all_prefixes;
467 }
468
469 void
470 JvmtiEnvBase::set_event_callbacks(const jvmtiEventCallbacks* callbacks,
471 jint size_of_callbacks) {
472 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
473
474 size_t byte_cnt = sizeof(jvmtiEventCallbacks);
475
476 // clear in either case to be sure we got any gap between sizes
477 memset(&_event_callbacks, 0, byte_cnt);
478
479 // Now that JvmtiThreadState_lock is held, prevent a possible race condition where events
480 // are re-enabled by a call to set event callbacks where the DisposeEnvironment
481 // occurs after the boiler-plate environment check and before the lock is acquired.
482 if (callbacks != NULL && is_valid()) {
483 if (size_of_callbacks < (jint)byte_cnt) {
484 byte_cnt = size_of_callbacks;
485 }
486 memcpy(&_event_callbacks, callbacks, byte_cnt);
487 }
488 }
489
490 // Called from JVMTI entry points which perform stack walking. If the
491 // associated JavaThread is the current thread, then wait_for_suspend
492 // is not used. Otherwise, it determines if we should wait for the
493 // "other" thread to complete external suspension. (NOTE: in future
494 // releases the suspension mechanism should be reimplemented so this
495 // is not necessary.)
496 //
497 bool
498 JvmtiEnvBase::is_thread_fully_suspended(JavaThread* thr, bool wait_for_suspend, uint32_t *bits) {
499 // "other" threads require special handling
500 if (thr != JavaThread::current()) {
501 if (wait_for_suspend) {
502 // We are allowed to wait for the external suspend to complete
503 // so give the other thread a chance to get suspended.
504 if (!thr->wait_for_ext_suspend_completion(SuspendRetryCount,
505 SuspendRetryDelay, bits)) {
506 // didn't make it so let the caller know
507 return false;
508 }
509 }
510 // We aren't allowed to wait for the external suspend to complete
511 // so if the other thread isn't externally suspended we need to
512 // let the caller know.
513 else if (!thr->is_ext_suspend_completed_with_lock(bits)) {
514 return false;
515 }
516 }
517
518 return true;
519 }
520
521
522 // In the fullness of time, all users of the method should instead
523 // directly use allocate, besides being cleaner and faster, this will
524 // mean much better out of memory handling
525 unsigned char *
526 JvmtiEnvBase::jvmtiMalloc(jlong size) {
527 unsigned char* mem = NULL;
528 jvmtiError result = allocate(size, &mem);
529 assert(result == JVMTI_ERROR_NONE, "Allocate failed");
530 return mem;
531 }
532
533
534 //
535 // Threads
536 //
537
538 jobject *
539 JvmtiEnvBase::new_jobjectArray(int length, Handle *handles) {
540 if (length == 0) {
541 return NULL;
542 }
543
544 jobject *objArray = (jobject *) jvmtiMalloc(sizeof(jobject) * length);
545 NULL_CHECK(objArray, NULL);
546
547 for (int i=0; i<length; i++) {
548 objArray[i] = jni_reference(handles[i]);
549 }
550 return objArray;
551 }
552
553 jthread *
554 JvmtiEnvBase::new_jthreadArray(int length, Handle *handles) {
555 return (jthread *) new_jobjectArray(length,handles);
556 }
557
558 jthreadGroup *
559 JvmtiEnvBase::new_jthreadGroupArray(int length, Handle *handles) {
560 return (jthreadGroup *) new_jobjectArray(length,handles);
561 }
562
563
564 JavaThread *
565 JvmtiEnvBase::get_JavaThread(jthread jni_thread) {
566 oop t = JNIHandles::resolve_external_guard(jni_thread);
567 if (t == NULL || !t->is_a(SystemDictionary::Thread_klass())) {
568 return NULL;
569 }
570 // The following returns NULL if the thread has not yet run or is in
571 // process of exiting
572 return java_lang_Thread::thread(t);
573 }
574
575
576 // return the vframe on the specified thread and depth, NULL if no such frame
577 vframe*
578 JvmtiEnvBase::vframeFor(JavaThread* java_thread, jint depth) {
579 if (!java_thread->has_last_Java_frame()) {
580 return NULL;
581 }
582 RegisterMap reg_map(java_thread);
583 vframe *vf = java_thread->last_java_vframe(®_map);
584 int d = 0;
585 while ((vf != NULL) && (d < depth)) {
586 vf = vf->java_sender();
587 d++;
588 }
589 return vf;
590 }
591
592
593 //
594 // utilities: JNI objects
595 //
596
597
598 jclass
599 JvmtiEnvBase::get_jni_class_non_null(Klass* k) {
600 assert(k != NULL, "k != NULL");
601 Thread *thread = Thread::current();
602 return (jclass)jni_reference(Handle(thread, k->java_mirror()));
603 }
604
605 //
606 // Field Information
607 //
608
609 bool
610 JvmtiEnvBase::get_field_descriptor(Klass* k, jfieldID field, fieldDescriptor* fd) {
611 if (!jfieldIDWorkaround::is_valid_jfieldID(k, field)) {
612 return false;
613 }
614 bool found = false;
615 if (jfieldIDWorkaround::is_static_jfieldID(field)) {
616 JNIid* id = jfieldIDWorkaround::from_static_jfieldID(field);
617 found = id->find_local_field(fd);
618 } else {
619 // Non-static field. The fieldID is really the offset of the field within the object.
620 int offset = jfieldIDWorkaround::from_instance_jfieldID(k, field);
621 found = InstanceKlass::cast(k)->find_field_from_offset(offset, false, fd);
622 }
623 return found;
624 }
625
626 //
627 // Object Monitor Information
628 //
629
630 //
631 // Count the number of objects for a lightweight monitor. The hobj
632 // parameter is object that owns the monitor so this routine will
633 // count the number of times the same object was locked by frames
634 // in java_thread.
635 //
636 jint
637 JvmtiEnvBase::count_locked_objects(JavaThread *java_thread, Handle hobj) {
638 jint ret = 0;
639 if (!java_thread->has_last_Java_frame()) {
640 return ret; // no Java frames so no monitors
641 }
642
643 ResourceMark rm;
644 HandleMark hm;
645 RegisterMap reg_map(java_thread);
646
647 for(javaVFrame *jvf=java_thread->last_java_vframe(®_map); jvf != NULL;
648 jvf = jvf->java_sender()) {
649 GrowableArray<MonitorInfo*>* mons = jvf->monitors();
650 if (!mons->is_empty()) {
651 for (int i = 0; i < mons->length(); i++) {
652 MonitorInfo *mi = mons->at(i);
653 if (mi->owner_is_scalar_replaced()) continue;
654
655 // see if owner of the monitor is our object
656 if (mi->owner() != NULL && mi->owner() == hobj()) {
657 ret++;
658 }
659 }
660 }
661 }
662 return ret;
663 }
664
665
666
667 jvmtiError
668 JvmtiEnvBase::get_current_contended_monitor(JavaThread *calling_thread, JavaThread *java_thread, jobject *monitor_ptr) {
669 #ifdef ASSERT
670 uint32_t debug_bits = 0;
671 #endif
672 assert((SafepointSynchronize::is_at_safepoint() ||
673 is_thread_fully_suspended(java_thread, false, &debug_bits)),
674 "at safepoint or target thread is suspended");
675 oop obj = NULL;
676 ObjectMonitor *mon = java_thread->current_waiting_monitor();
677 if (mon == NULL) {
678 // thread is not doing an Object.wait() call
679 mon = java_thread->current_pending_monitor();
680 if (mon != NULL) {
681 // The thread is trying to enter() or raw_enter() an ObjectMonitor.
682 obj = (oop)mon->object();
683 // If obj == NULL, then ObjectMonitor is raw which doesn't count
684 // as contended for this API
685 }
686 // implied else: no contended ObjectMonitor
687 } else {
688 // thread is doing an Object.wait() call
689 obj = (oop)mon->object();
690 assert(obj != NULL, "Object.wait() should have an object");
691 }
692
693 if (obj == NULL) {
694 *monitor_ptr = NULL;
695 } else {
696 HandleMark hm;
697 Handle hobj(Thread::current(), obj);
698 *monitor_ptr = jni_reference(calling_thread, hobj);
699 }
700 return JVMTI_ERROR_NONE;
701 }
702
703
704 jvmtiError
705 JvmtiEnvBase::get_owned_monitors(JavaThread *calling_thread, JavaThread* java_thread,
706 GrowableArray<jvmtiMonitorStackDepthInfo*> *owned_monitors_list) {
707 jvmtiError err = JVMTI_ERROR_NONE;
708 #ifdef ASSERT
709 uint32_t debug_bits = 0;
710 #endif
711 assert((SafepointSynchronize::is_at_safepoint() ||
712 is_thread_fully_suspended(java_thread, false, &debug_bits)),
713 "at safepoint or target thread is suspended");
714
715 if (java_thread->has_last_Java_frame()) {
716 ResourceMark rm;
717 HandleMark hm;
718 RegisterMap reg_map(java_thread);
719
720 int depth = 0;
721 for (javaVFrame *jvf = java_thread->last_java_vframe(®_map); jvf != NULL;
722 jvf = jvf->java_sender()) {
723 if (depth++ < MaxJavaStackTraceDepth) { // check for stack too deep
724 // add locked objects for this frame into list
725 err = get_locked_objects_in_frame(calling_thread, java_thread, jvf, owned_monitors_list, depth-1);
726 if (err != JVMTI_ERROR_NONE) {
727 return err;
728 }
729 }
730 }
731 }
732
733 // Get off stack monitors. (e.g. acquired via jni MonitorEnter).
734 JvmtiMonitorClosure jmc(java_thread, calling_thread, owned_monitors_list, this);
735 ObjectSynchronizer::monitors_iterate(&jmc);
736 err = jmc.error();
737
738 return err;
739 }
740
741 // Save JNI local handles for any objects that this frame owns.
742 jvmtiError
743 JvmtiEnvBase::get_locked_objects_in_frame(JavaThread* calling_thread, JavaThread* java_thread,
744 javaVFrame *jvf, GrowableArray<jvmtiMonitorStackDepthInfo*>* owned_monitors_list, int stack_depth) {
745 jvmtiError err = JVMTI_ERROR_NONE;
746 ResourceMark rm;
747
748 GrowableArray<MonitorInfo*>* mons = jvf->monitors();
749 if (mons->is_empty()) {
750 return err; // this javaVFrame holds no monitors
751 }
752
753 HandleMark hm;
754 oop wait_obj = NULL;
755 {
756 // save object of current wait() call (if any) for later comparison
757 ObjectMonitor *mon = java_thread->current_waiting_monitor();
758 if (mon != NULL) {
759 wait_obj = (oop)mon->object();
760 }
761 }
762 oop pending_obj = NULL;
763 {
764 // save object of current enter() call (if any) for later comparison
765 ObjectMonitor *mon = java_thread->current_pending_monitor();
766 if (mon != NULL) {
767 pending_obj = (oop)mon->object();
768 }
769 }
770
771 for (int i = 0; i < mons->length(); i++) {
772 MonitorInfo *mi = mons->at(i);
773
774 if (mi->owner_is_scalar_replaced()) continue;
775
776 oop obj = mi->owner();
777 if (obj == NULL) {
778 // this monitor doesn't have an owning object so skip it
779 continue;
780 }
781
782 if (wait_obj == obj) {
783 // the thread is waiting on this monitor so it isn't really owned
784 continue;
785 }
786
787 if (pending_obj == obj) {
788 // the thread is pending on this monitor so it isn't really owned
789 continue;
790 }
791
792 if (owned_monitors_list->length() > 0) {
793 // Our list has at least one object on it so we have to check
794 // for recursive object locking
795 bool found = false;
796 for (int j = 0; j < owned_monitors_list->length(); j++) {
797 jobject jobj = ((jvmtiMonitorStackDepthInfo*)owned_monitors_list->at(j))->monitor;
798 oop check = JNIHandles::resolve(jobj);
799 if (check == obj) {
800 found = true; // we found the object
801 break;
802 }
803 }
804
805 if (found) {
806 // already have this object so don't include it
807 continue;
808 }
809 }
810
811 // add the owning object to our list
812 jvmtiMonitorStackDepthInfo *jmsdi;
813 err = allocate(sizeof(jvmtiMonitorStackDepthInfo), (unsigned char **)&jmsdi);
814 if (err != JVMTI_ERROR_NONE) {
815 return err;
816 }
817 Handle hobj(Thread::current(), obj);
818 jmsdi->monitor = jni_reference(calling_thread, hobj);
819 jmsdi->stack_depth = stack_depth;
820 owned_monitors_list->append(jmsdi);
821 }
822
823 return err;
824 }
825
826 jvmtiError
827 JvmtiEnvBase::get_stack_trace(JavaThread *java_thread,
828 jint start_depth, jint max_count,
829 jvmtiFrameInfo* frame_buffer, jint* count_ptr) {
830 #ifdef ASSERT
831 uint32_t debug_bits = 0;
832 #endif
833 assert((SafepointSynchronize::is_at_safepoint() ||
834 is_thread_fully_suspended(java_thread, false, &debug_bits)),
835 "at safepoint or target thread is suspended");
836 int count = 0;
837 if (java_thread->has_last_Java_frame()) {
838 RegisterMap reg_map(java_thread);
839 Thread* current_thread = Thread::current();
840 ResourceMark rm(current_thread);
841 javaVFrame *jvf = java_thread->last_java_vframe(®_map);
842 HandleMark hm(current_thread);
843 if (start_depth != 0) {
844 if (start_depth > 0) {
845 for (int j = 0; j < start_depth && jvf != NULL; j++) {
846 jvf = jvf->java_sender();
847 }
848 if (jvf == NULL) {
849 // start_depth is deeper than the stack depth
850 return JVMTI_ERROR_ILLEGAL_ARGUMENT;
851 }
852 } else { // start_depth < 0
853 // we are referencing the starting depth based on the oldest
854 // part of the stack.
855 // optimize to limit the number of times that java_sender() is called
856 javaVFrame *jvf_cursor = jvf;
857 javaVFrame *jvf_prev = NULL;
858 javaVFrame *jvf_prev_prev = NULL;
859 int j = 0;
860 while (jvf_cursor != NULL) {
861 jvf_prev_prev = jvf_prev;
862 jvf_prev = jvf_cursor;
863 for (j = 0; j > start_depth && jvf_cursor != NULL; j--) {
864 jvf_cursor = jvf_cursor->java_sender();
865 }
866 }
867 if (j == start_depth) {
868 // previous pointer is exactly where we want to start
869 jvf = jvf_prev;
870 } else {
871 // we need to back up further to get to the right place
872 if (jvf_prev_prev == NULL) {
873 // the -start_depth is greater than the stack depth
874 return JVMTI_ERROR_ILLEGAL_ARGUMENT;
875 }
876 // j now is the number of frames on the stack starting with
877 // jvf_prev, we start from jvf_prev_prev and move older on
878 // the stack that many, the result is -start_depth frames
879 // remaining.
880 jvf = jvf_prev_prev;
881 for (; j < 0; j++) {
882 jvf = jvf->java_sender();
883 }
884 }
885 }
886 }
887 for (; count < max_count && jvf != NULL; count++) {
888 frame_buffer[count].method = jvf->method()->jmethod_id();
889 frame_buffer[count].location = (jvf->method()->is_native() ? -1 : jvf->bci());
890 jvf = jvf->java_sender();
891 }
892 } else {
893 if (start_depth != 0) {
894 // no frames and there is a starting depth
895 return JVMTI_ERROR_ILLEGAL_ARGUMENT;
896 }
897 }
898 *count_ptr = count;
899 return JVMTI_ERROR_NONE;
900 }
901
902 jvmtiError
903 JvmtiEnvBase::get_frame_count(JvmtiThreadState *state, jint *count_ptr) {
904 assert((state != NULL),
905 "JavaThread should create JvmtiThreadState before calling this method");
906 *count_ptr = state->count_frames();
907 return JVMTI_ERROR_NONE;
908 }
909
910 jvmtiError
911 JvmtiEnvBase::get_frame_location(JavaThread *java_thread, jint depth,
912 jmethodID* method_ptr, jlocation* location_ptr) {
913 #ifdef ASSERT
914 uint32_t debug_bits = 0;
915 #endif
916 assert((SafepointSynchronize::is_at_safepoint() ||
917 is_thread_fully_suspended(java_thread, false, &debug_bits)),
918 "at safepoint or target thread is suspended");
919 Thread* current_thread = Thread::current();
920 ResourceMark rm(current_thread);
921
922 vframe *vf = vframeFor(java_thread, depth);
923 if (vf == NULL) {
924 return JVMTI_ERROR_NO_MORE_FRAMES;
925 }
926
927 // vframeFor should return a java frame. If it doesn't
928 // it means we've got an internal error and we return the
929 // error in product mode. In debug mode we will instead
930 // attempt to cast the vframe to a javaVFrame and will
931 // cause an assertion/crash to allow further diagnosis.
932 #ifdef PRODUCT
933 if (!vf->is_java_frame()) {
934 return JVMTI_ERROR_INTERNAL;
935 }
936 #endif
937
938 HandleMark hm(current_thread);
939 javaVFrame *jvf = javaVFrame::cast(vf);
940 Method* method = jvf->method();
941 if (method->is_native()) {
942 *location_ptr = -1;
943 } else {
944 *location_ptr = jvf->bci();
945 }
946 *method_ptr = method->jmethod_id();
947
948 return JVMTI_ERROR_NONE;
949 }
950
951
952 jvmtiError
953 JvmtiEnvBase::get_object_monitor_usage(JavaThread* calling_thread, jobject object, jvmtiMonitorUsage* info_ptr) {
954 HandleMark hm;
955 Handle hobj;
956
957 Thread* current_thread = Thread::current();
958 bool at_safepoint = SafepointSynchronize::is_at_safepoint();
959
960 // Check arguments
961 {
962 oop mirror = JNIHandles::resolve_external_guard(object);
963 NULL_CHECK(mirror, JVMTI_ERROR_INVALID_OBJECT);
964 NULL_CHECK(info_ptr, JVMTI_ERROR_NULL_POINTER);
965
966 hobj = Handle(current_thread, mirror);
967 }
968
969 JavaThread *owning_thread = NULL;
970 ObjectMonitor *mon = NULL;
971 jvmtiMonitorUsage ret = {
972 NULL, 0, 0, NULL, 0, NULL
973 };
974
975 uint32_t debug_bits = 0;
976 // first derive the object's owner and entry_count (if any)
977 {
978 // Revoke any biases before querying the mark word
979 if (SafepointSynchronize::is_at_safepoint()) {
980 BiasedLocking::revoke_at_safepoint(hobj);
981 } else {
982 BiasedLocking::revoke_and_rebias(hobj, false, calling_thread);
983 }
984
985 address owner = NULL;
986 {
987 markOop mark = hobj()->mark();
988
989 if (!mark->has_monitor()) {
990 // this object has a lightweight monitor
991
992 if (mark->has_locker()) {
993 owner = (address)mark->locker(); // save the address of the Lock word
994 }
995 // implied else: no owner
996 } else {
997 // this object has a heavyweight monitor
998 mon = mark->monitor();
999
1000 // The owner field of a heavyweight monitor may be NULL for no
1001 // owner, a JavaThread * or it may still be the address of the
1002 // Lock word in a JavaThread's stack. A monitor can be inflated
1003 // by a non-owning JavaThread, but only the owning JavaThread
1004 // can change the owner field from the Lock word to the
1005 // JavaThread * and it may not have done that yet.
1006 owner = (address)mon->owner();
1007 }
1008 }
1009
1010 if (owner != NULL) {
1011 // This monitor is owned so we have to find the owning JavaThread.
1012 // Since owning_thread_from_monitor_owner() grabs a lock, GC can
1013 // move our object at this point. However, our owner value is safe
1014 // since it is either the Lock word on a stack or a JavaThread *.
1015 owning_thread = Threads::owning_thread_from_monitor_owner(owner, !at_safepoint);
1016 // Cannot assume (owning_thread != NULL) here because this function
1017 // may not have been called at a safepoint and the owning_thread
1018 // might not be suspended.
1019 if (owning_thread != NULL) {
1020 // The monitor's owner either has to be the current thread, at safepoint
1021 // or it has to be suspended. Any of these conditions will prevent both
1022 // contending and waiting threads from modifying the state of
1023 // the monitor.
1024 if (!at_safepoint && !JvmtiEnv::is_thread_fully_suspended(owning_thread, true, &debug_bits)) {
1025 // Don't worry! This return of JVMTI_ERROR_THREAD_NOT_SUSPENDED
1026 // will not make it back to the JVM/TI agent. The error code will
1027 // get intercepted in JvmtiEnv::GetObjectMonitorUsage() which
1028 // will retry the call via a VM_GetObjectMonitorUsage VM op.
1029 return JVMTI_ERROR_THREAD_NOT_SUSPENDED;
1030 }
1031 HandleMark hm;
1032 Handle th(current_thread, owning_thread->threadObj());
1033 ret.owner = (jthread)jni_reference(calling_thread, th);
1034 }
1035 // implied else: no owner
1036 }
1037
1038 if (owning_thread != NULL) { // monitor is owned
1039 // The recursions field of a monitor does not reflect recursions
1040 // as lightweight locks before inflating the monitor are not included.
1041 // We have to count the number of recursive monitor entries the hard way.
1042 // We pass a handle to survive any GCs along the way.
1043 ResourceMark rm;
1044 ret.entry_count = count_locked_objects(owning_thread, hobj);
1045 }
1046 // implied else: entry_count == 0
1047 }
1048
1049 jint nWant = 0, nWait = 0;
1050 if (mon != NULL) {
1051 // this object has a heavyweight monitor
1052 nWant = mon->contentions(); // # of threads contending for monitor
1053 nWait = mon->waiters(); // # of threads in Object.wait()
1054 ret.waiter_count = nWant + nWait;
1055 ret.notify_waiter_count = nWait;
1056 } else {
1057 // this object has a lightweight monitor
1058 ret.waiter_count = 0;
1059 ret.notify_waiter_count = 0;
1060 }
1061
1062 // Allocate memory for heavyweight and lightweight monitor.
1063 jvmtiError err;
1064 err = allocate(ret.waiter_count * sizeof(jthread *), (unsigned char**)&ret.waiters);
1065 if (err != JVMTI_ERROR_NONE) {
1066 return err;
1067 }
1068 err = allocate(ret.notify_waiter_count * sizeof(jthread *),
1069 (unsigned char**)&ret.notify_waiters);
1070 if (err != JVMTI_ERROR_NONE) {
1071 deallocate((unsigned char*)ret.waiters);
1072 return err;
1073 }
1074
1075 // now derive the rest of the fields
1076 if (mon != NULL) {
1077 // this object has a heavyweight monitor
1078
1079 // Number of waiters may actually be less than the waiter count.
1080 // So NULL out memory so that unused memory will be NULL.
1081 memset(ret.waiters, 0, ret.waiter_count * sizeof(jthread *));
1082 memset(ret.notify_waiters, 0, ret.notify_waiter_count * sizeof(jthread *));
1083
1084 if (ret.waiter_count > 0) {
1085 // we have contending and/or waiting threads
1086 HandleMark hm;
1087 if (nWant > 0) {
1088 // we have contending threads
1089 ResourceMark rm;
1090 // get_pending_threads returns only java thread so we do not need to
1091 // check for non java threads.
1092 GrowableArray<JavaThread*>* wantList = Threads::get_pending_threads(
1093 nWant, (address)mon, !at_safepoint);
1094 if (wantList->length() < nWant) {
1095 // robustness: the pending list has gotten smaller
1096 nWant = wantList->length();
1097 }
1098 for (int i = 0; i < nWant; i++) {
1099 JavaThread *pending_thread = wantList->at(i);
1100 // If the monitor has no owner, then a non-suspended contending
1101 // thread could potentially change the state of the monitor by
1102 // entering it. The JVM/TI spec doesn't allow this.
1103 if (owning_thread == NULL && !at_safepoint &
1104 !JvmtiEnv::is_thread_fully_suspended(pending_thread, true, &debug_bits)) {
1105 if (ret.owner != NULL) {
1106 destroy_jni_reference(calling_thread, ret.owner);
1107 }
1108 for (int j = 0; j < i; j++) {
1109 destroy_jni_reference(calling_thread, ret.waiters[j]);
1110 }
1111 deallocate((unsigned char*)ret.waiters);
1112 deallocate((unsigned char*)ret.notify_waiters);
1113 return JVMTI_ERROR_THREAD_NOT_SUSPENDED;
1114 }
1115 Handle th(current_thread, pending_thread->threadObj());
1116 ret.waiters[i] = (jthread)jni_reference(calling_thread, th);
1117 }
1118 }
1119 if (nWait > 0) {
1120 // we have threads in Object.wait()
1121 int offset = nWant; // add after any contending threads
1122 ObjectWaiter *waiter = mon->first_waiter();
1123 for (int i = 0, j = 0; i < nWait; i++) {
1124 if (waiter == NULL) {
1125 // robustness: the waiting list has gotten smaller
1126 nWait = j;
1127 break;
1128 }
1129 Thread *t = mon->thread_of_waiter(waiter);
1130 if (t != NULL && t->is_Java_thread()) {
1131 JavaThread *wjava_thread = (JavaThread *)t;
1132 // If the thread was found on the ObjectWaiter list, then
1133 // it has not been notified. This thread can't change the
1134 // state of the monitor so it doesn't need to be suspended.
1135 Handle th(current_thread, wjava_thread->threadObj());
1136 ret.waiters[offset + j] = (jthread)jni_reference(calling_thread, th);
1137 ret.notify_waiters[j++] = (jthread)jni_reference(calling_thread, th);
1138 }
1139 waiter = mon->next_waiter(waiter);
1140 }
1141 }
1142 }
1143
1144 // Adjust count. nWant and nWait count values may be less than original.
1145 ret.waiter_count = nWant + nWait;
1146 ret.notify_waiter_count = nWait;
1147 } else {
1148 // this object has a lightweight monitor and we have nothing more
1149 // to do here because the defaults are just fine.
1150 }
1151
1152 // we don't update return parameter unless everything worked
1153 *info_ptr = ret;
1154
1155 return JVMTI_ERROR_NONE;
1156 }
1157
1158 ResourceTracker::ResourceTracker(JvmtiEnv* env) {
1159 _env = env;
1160 _allocations = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<unsigned char*>(20, true);
1161 _failed = false;
1162 }
1163 ResourceTracker::~ResourceTracker() {
1164 if (_failed) {
1165 for (int i=0; i<_allocations->length(); i++) {
1166 _env->deallocate(_allocations->at(i));
1167 }
1168 }
1169 delete _allocations;
1170 }
1171
1172 jvmtiError ResourceTracker::allocate(jlong size, unsigned char** mem_ptr) {
1173 unsigned char *ptr;
1174 jvmtiError err = _env->allocate(size, &ptr);
1175 if (err == JVMTI_ERROR_NONE) {
1176 _allocations->append(ptr);
1177 *mem_ptr = ptr;
1178 } else {
1179 *mem_ptr = NULL;
1180 _failed = true;
1181 }
1182 return err;
1183 }
1184
1185 unsigned char* ResourceTracker::allocate(jlong size) {
1186 unsigned char* ptr;
1187 allocate(size, &ptr);
1188 return ptr;
1189 }
1190
1191 char* ResourceTracker::strdup(const char* str) {
1192 char *dup_str = (char*)allocate(strlen(str)+1);
1193 if (dup_str != NULL) {
1194 strcpy(dup_str, str);
1195 }
1196 return dup_str;
1197 }
1198
1199 struct StackInfoNode {
1200 struct StackInfoNode *next;
1201 jvmtiStackInfo info;
1202 };
1203
1204 // Create a jvmtiStackInfo inside a linked list node and create a
1205 // buffer for the frame information, both allocated as resource objects.
1206 // Fill in both the jvmtiStackInfo and the jvmtiFrameInfo.
1207 // Note that either or both of thr and thread_oop
1208 // may be null if the thread is new or has exited.
1209 void
1210 VM_GetMultipleStackTraces::fill_frames(jthread jt, JavaThread *thr, oop thread_oop) {
1211 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
1212
1213 jint state = 0;
1214 struct StackInfoNode *node = NEW_RESOURCE_OBJ(struct StackInfoNode);
1215 jvmtiStackInfo *infop = &(node->info);
1216 node->next = head();
1217 set_head(node);
1218 infop->frame_count = 0;
1219 infop->thread = jt;
1220
1221 if (thread_oop != NULL) {
1222 // get most state bits
1223 state = (jint)java_lang_Thread::get_thread_status(thread_oop);
1224 }
1225
1226 if (thr != NULL) { // add more state bits if there is a JavaThead to query
1227 // same as is_being_ext_suspended() but without locking
1228 if (thr->is_ext_suspended() || thr->is_external_suspend()) {
1229 state |= JVMTI_THREAD_STATE_SUSPENDED;
1230 }
1231 JavaThreadState jts = thr->thread_state();
1232 if (jts == _thread_in_native) {
1233 state |= JVMTI_THREAD_STATE_IN_NATIVE;
1234 }
1235 OSThread* osThread = thr->osthread();
1236 if (osThread != NULL && osThread->interrupted()) {
1237 state |= JVMTI_THREAD_STATE_INTERRUPTED;
1238 }
1239 }
1240 infop->state = state;
1241
1242 if (thr != NULL || (state & JVMTI_THREAD_STATE_ALIVE) != 0) {
1243 infop->frame_buffer = NEW_RESOURCE_ARRAY(jvmtiFrameInfo, max_frame_count());
1244 env()->get_stack_trace(thr, 0, max_frame_count(),
1245 infop->frame_buffer, &(infop->frame_count));
1246 } else {
1247 infop->frame_buffer = NULL;
1248 infop->frame_count = 0;
1249 }
1250 _frame_count_total += infop->frame_count;
1251 }
1252
1253 // Based on the stack information in the linked list, allocate memory
1254 // block to return and fill it from the info in the linked list.
1255 void
1256 VM_GetMultipleStackTraces::allocate_and_fill_stacks(jint thread_count) {
1257 // do I need to worry about alignment issues?
1258 jlong alloc_size = thread_count * sizeof(jvmtiStackInfo)
1259 + _frame_count_total * sizeof(jvmtiFrameInfo);
1260 env()->allocate(alloc_size, (unsigned char **)&_stack_info);
1261
1262 // pointers to move through the newly allocated space as it is filled in
1263 jvmtiStackInfo *si = _stack_info + thread_count; // bottom of stack info
1264 jvmtiFrameInfo *fi = (jvmtiFrameInfo *)si; // is the top of frame info
1265
1266 // copy information in resource area into allocated buffer
1267 // insert stack info backwards since linked list is backwards
1268 // insert frame info forwards
1269 // walk the StackInfoNodes
1270 for (struct StackInfoNode *sin = head(); sin != NULL; sin = sin->next) {
1271 jint frame_count = sin->info.frame_count;
1272 size_t frames_size = frame_count * sizeof(jvmtiFrameInfo);
1273 --si;
1274 memcpy(si, &(sin->info), sizeof(jvmtiStackInfo));
1275 if (frames_size == 0) {
1276 si->frame_buffer = NULL;
1277 } else {
1278 memcpy(fi, sin->info.frame_buffer, frames_size);
1279 si->frame_buffer = fi; // point to the new allocated copy of the frames
1280 fi += frame_count;
1281 }
1282 }
1283 assert(si == _stack_info, "the last copied stack info must be the first record");
1284 assert((unsigned char *)fi == ((unsigned char *)_stack_info) + alloc_size,
1285 "the last copied frame info must be the last record");
1286 }
1287
1288
1289 void
1290 VM_GetThreadListStackTraces::doit() {
1291 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
1292
1293 ResourceMark rm;
1294 for (int i = 0; i < _thread_count; ++i) {
1295 jthread jt = _thread_list[i];
1296 oop thread_oop = JNIHandles::resolve_external_guard(jt);
1297 if (thread_oop == NULL || !thread_oop->is_a(SystemDictionary::Thread_klass())) {
1298 set_result(JVMTI_ERROR_INVALID_THREAD);
1299 return;
1300 }
1301 fill_frames(jt, java_lang_Thread::thread(thread_oop), thread_oop);
1302 }
1303 allocate_and_fill_stacks(_thread_count);
1304 }
1305
1306 void
1307 VM_GetAllStackTraces::doit() {
1308 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
1309
1310 ResourceMark rm;
1311 _final_thread_count = 0;
1312 for (JavaThread *jt = Threads::first(); jt != NULL; jt = jt->next()) {
1313 oop thread_oop = jt->threadObj();
1314 if (thread_oop != NULL &&
1315 !jt->is_exiting() &&
1316 java_lang_Thread::is_alive(thread_oop) &&
1317 !jt->is_hidden_from_external_view()) {
1318 ++_final_thread_count;
1319 // Handle block of the calling thread is used to create local refs.
1320 fill_frames((jthread)JNIHandles::make_local(_calling_thread, thread_oop),
1321 jt, thread_oop);
1322 }
1323 }
1324 allocate_and_fill_stacks(_final_thread_count);
1325 }
1326
1327 // Verifies that the top frame is a java frame in an expected state.
1328 // Deoptimizes frame if needed.
1329 // Checks that the frame method signature matches the return type (tos).
1330 // HandleMark must be defined in the caller only.
1331 // It is to keep a ret_ob_h handle alive after return to the caller.
1332 jvmtiError
1333 JvmtiEnvBase::check_top_frame(JavaThread* current_thread, JavaThread* java_thread,
1334 jvalue value, TosState tos, Handle* ret_ob_h) {
1335 ResourceMark rm(current_thread);
1336
1337 vframe *vf = vframeFor(java_thread, 0);
1338 NULL_CHECK(vf, JVMTI_ERROR_NO_MORE_FRAMES);
1339
1340 javaVFrame *jvf = (javaVFrame*) vf;
1341 if (!vf->is_java_frame() || jvf->method()->is_native()) {
1342 return JVMTI_ERROR_OPAQUE_FRAME;
1343 }
1344
1345 // If the frame is a compiled one, need to deoptimize it.
1346 if (vf->is_compiled_frame()) {
1347 if (!vf->fr().can_be_deoptimized()) {
1348 return JVMTI_ERROR_OPAQUE_FRAME;
1349 }
1350 Deoptimization::deoptimize_frame(java_thread, jvf->fr().id());
1351 }
1352
1353 // Get information about method return type
1354 Symbol* signature = jvf->method()->signature();
1355
1356 ResultTypeFinder rtf(signature);
1357 TosState fr_tos = as_TosState(rtf.type());
1358 if (fr_tos != tos) {
1359 if (tos != itos || (fr_tos != btos && fr_tos != ztos && fr_tos != ctos && fr_tos != stos)) {
1360 return JVMTI_ERROR_TYPE_MISMATCH;
1361 }
1362 }
1363
1364 // Check that the jobject class matches the return type signature.
1365 jobject jobj = value.l;
1366 if (tos == atos && jobj != NULL) { // NULL reference is allowed
1367 Handle ob_h(current_thread, JNIHandles::resolve_external_guard(jobj));
1368 NULL_CHECK(ob_h, JVMTI_ERROR_INVALID_OBJECT);
1369 Klass* ob_k = ob_h()->klass();
1370 NULL_CHECK(ob_k, JVMTI_ERROR_INVALID_OBJECT);
1371
1372 // Method return type signature.
1373 char* ty_sign = 1 + strchr(signature->as_C_string(), ')');
1374
1375 if (!VM_GetOrSetLocal::is_assignable(ty_sign, ob_k, current_thread)) {
1376 return JVMTI_ERROR_TYPE_MISMATCH;
1377 }
1378 *ret_ob_h = ob_h;
1379 }
1380 return JVMTI_ERROR_NONE;
1381 } /* end check_top_frame */
1382
1383
1384 // ForceEarlyReturn<type> follows the PopFrame approach in many aspects.
1385 // Main difference is on the last stage in the interpreter.
1386 // The PopFrame stops method execution to continue execution
1387 // from the same method call instruction.
1388 // The ForceEarlyReturn forces return from method so the execution
1389 // continues at the bytecode following the method call.
1390
1391 // Threads_lock NOT held, java_thread not protected by lock
1392 // java_thread - pre-checked
1393
1394 jvmtiError
1395 JvmtiEnvBase::force_early_return(JavaThread* java_thread, jvalue value, TosState tos) {
1396 JavaThread* current_thread = JavaThread::current();
1397 HandleMark hm(current_thread);
1398 uint32_t debug_bits = 0;
1399
1400 // retrieve or create the state
1401 JvmtiThreadState* state = JvmtiThreadState::state_for(java_thread);
1402 if (state == NULL) {
1403 return JVMTI_ERROR_THREAD_NOT_ALIVE;
1404 }
1405
1406 // Check if java_thread is fully suspended
1407 if (!is_thread_fully_suspended(java_thread,
1408 true /* wait for suspend completion */,
1409 &debug_bits)) {
1410 return JVMTI_ERROR_THREAD_NOT_SUSPENDED;
1411 }
1412
1413 // Check to see if a ForceEarlyReturn was already in progress
1414 if (state->is_earlyret_pending()) {
1415 // Probably possible for JVMTI clients to trigger this, but the
1416 // JPDA backend shouldn't allow this to happen
1417 return JVMTI_ERROR_INTERNAL;
1418 }
1419 {
1420 // The same as for PopFrame. Workaround bug:
1421 // 4812902: popFrame hangs if the method is waiting at a synchronize
1422 // Catch this condition and return an error to avoid hanging.
1423 // Now JVMTI spec allows an implementation to bail out with an opaque
1424 // frame error.
1425 OSThread* osThread = java_thread->osthread();
1426 if (osThread->get_state() == MONITOR_WAIT) {
1427 return JVMTI_ERROR_OPAQUE_FRAME;
1428 }
1429 }
1430 Handle ret_ob_h;
1431 jvmtiError err = check_top_frame(current_thread, java_thread, value, tos, &ret_ob_h);
1432 if (err != JVMTI_ERROR_NONE) {
1433 return err;
1434 }
1435 assert(tos != atos || value.l == NULL || ret_ob_h() != NULL,
1436 "return object oop must not be NULL if jobject is not NULL");
1437
1438 // Update the thread state to reflect that the top frame must be
1439 // forced to return.
1440 // The current frame will be returned later when the suspended
1441 // thread is resumed and right before returning from VM to Java.
1442 // (see call_VM_base() in assembler_<cpu>.cpp).
1443
1444 state->set_earlyret_pending();
1445 state->set_earlyret_oop(ret_ob_h());
1446 state->set_earlyret_value(value, tos);
1447
1448 // Set pending step flag for this early return.
1449 // It is cleared when next step event is posted.
1450 state->set_pending_step_for_earlyret();
1451
1452 return JVMTI_ERROR_NONE;
1453 } /* end force_early_return */
1454
1455 void
1456 JvmtiMonitorClosure::do_monitor(ObjectMonitor* mon) {
1457 if ( _error != JVMTI_ERROR_NONE) {
1458 // Error occurred in previous iteration so no need to add
1459 // to the list.
1460 return;
1461 }
1462 if (mon->owner() == _java_thread ) {
1463 // Filter out on stack monitors collected during stack walk.
1464 oop obj = (oop)mon->object();
1465 bool found = false;
1466 for (int j = 0; j < _owned_monitors_list->length(); j++) {
1467 jobject jobj = ((jvmtiMonitorStackDepthInfo*)_owned_monitors_list->at(j))->monitor;
1468 oop check = JNIHandles::resolve(jobj);
1469 if (check == obj) {
1470 // On stack monitor already collected during the stack walk.
1471 found = true;
1472 break;
1473 }
1474 }
1475 if (found == false) {
1476 // This is off stack monitor (e.g. acquired via jni MonitorEnter).
1477 jvmtiError err;
1478 jvmtiMonitorStackDepthInfo *jmsdi;
1479 err = _env->allocate(sizeof(jvmtiMonitorStackDepthInfo), (unsigned char **)&jmsdi);
1480 if (err != JVMTI_ERROR_NONE) {
1481 _error = err;
1482 return;
1483 }
1484 Handle hobj(Thread::current(), obj);
1485 jmsdi->monitor = _env->jni_reference(_calling_thread, hobj);
1486 // stack depth is unknown for this monitor.
1487 jmsdi->stack_depth = -1;
1488 _owned_monitors_list->append(jmsdi);
1489 }
1490 }
1491 }
1492
1493 GrowableArray<OopHandle>* JvmtiModuleClosure::_tbl = NULL;
1494
1495 jvmtiError
1496 JvmtiModuleClosure::get_all_modules(JvmtiEnv* env, jint* module_count_ptr, jobject** modules_ptr) {
1497 ResourceMark rm;
1498 MutexLocker ml(Module_lock);
1499
1500 _tbl = new GrowableArray<OopHandle>(77);
1501 if (_tbl == NULL) {
1502 return JVMTI_ERROR_OUT_OF_MEMORY;
1503 }
1504
1505 // Iterate over all the modules loaded to the system.
1506 ClassLoaderDataGraph::modules_do(&do_module);
1507
1508 jint len = _tbl->length();
1509 guarantee(len > 0, "at least one module must be present");
1510
1511 jobject* array = (jobject*)env->jvmtiMalloc((jlong)(len * sizeof(jobject)));
1512 if (array == NULL) {
1513 return JVMTI_ERROR_OUT_OF_MEMORY;
1514 }
1515 for (jint idx = 0; idx < len; idx++) {
1516 array[idx] = JNIHandles::make_local(Thread::current(), _tbl->at(idx).resolve());
1517 }
1518 _tbl = NULL;
1519 *modules_ptr = array;
1520 *module_count_ptr = len;
1521 return JVMTI_ERROR_NONE;
1522 }
1523