1 /*
2 * Copyright (c) 2003, 2020, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "classfile/classLoaderDataGraph.hpp"
27 #include "classfile/moduleEntry.hpp"
28 #include "classfile/systemDictionary.hpp"
29 #include "jvmtifiles/jvmtiEnv.hpp"
30 #include "memory/iterator.hpp"
31 #include "memory/resourceArea.hpp"
32 #include "oops/objArrayKlass.hpp"
33 #include "oops/objArrayOop.hpp"
34 #include "oops/oop.inline.hpp"
35 #include "oops/oopHandle.inline.hpp"
36 #include "prims/jvmtiEnvBase.hpp"
37 #include "prims/jvmtiEventController.inline.hpp"
38 #include "prims/jvmtiExtensions.hpp"
39 #include "prims/jvmtiImpl.hpp"
40 #include "prims/jvmtiManageCapabilities.hpp"
41 #include "prims/jvmtiTagMap.hpp"
42 #include "prims/jvmtiThreadState.inline.hpp"
43 #include "runtime/biasedLocking.hpp"
44 #include "runtime/deoptimization.hpp"
45 #include "runtime/frame.inline.hpp"
46 #include "runtime/handles.inline.hpp"
47 #include "runtime/interfaceSupport.inline.hpp"
48 #include "runtime/jfieldIDWorkaround.hpp"
49 #include "runtime/jniHandles.inline.hpp"
50 #include "runtime/objectMonitor.hpp"
51 #include "runtime/objectMonitor.inline.hpp"
52 #include "runtime/signature.hpp"
53 #include "runtime/thread.inline.hpp"
54 #include "runtime/threadSMR.hpp"
55 #include "runtime/vframe.hpp"
56 #include "runtime/vframe_hp.hpp"
57 #include "runtime/vmThread.hpp"
58 #include "runtime/vmOperations.hpp"
59
60 ///////////////////////////////////////////////////////////////
61 //
62 // JvmtiEnvBase
63 //
64
65 JvmtiEnvBase* JvmtiEnvBase::_head_environment = NULL;
66
67 bool JvmtiEnvBase::_globally_initialized = false;
68 volatile bool JvmtiEnvBase::_needs_clean_up = false;
69
70 jvmtiPhase JvmtiEnvBase::_phase = JVMTI_PHASE_PRIMORDIAL;
71
72 volatile int JvmtiEnvBase::_dying_thread_env_iteration_count = 0;
73
74 extern jvmtiInterface_1_ jvmti_Interface;
75 extern jvmtiInterface_1_ jvmtiTrace_Interface;
76
77
78 // perform initializations that must occur before any JVMTI environments
79 // are released but which should only be initialized once (no matter
80 // how many environments are created).
81 void
82 JvmtiEnvBase::globally_initialize() {
83 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
84 assert(_globally_initialized == false, "bad call");
85
86 JvmtiManageCapabilities::initialize();
87
88 // register extension functions and events
89 JvmtiExtensions::register_extensions();
90
91 #ifdef JVMTI_TRACE
92 JvmtiTrace::initialize();
93 #endif
94
95 _globally_initialized = true;
96 }
97
98
99 void
100 JvmtiEnvBase::initialize() {
101 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
102
103 // Add this environment to the end of the environment list (order is important)
104 {
105 // This block of code must not contain any safepoints, as list deallocation
106 // (which occurs at a safepoint) cannot occur simultaneously with this list
107 // addition. Note: NoSafepointVerifier cannot, currently, be used before
108 // threads exist.
109 JvmtiEnvIterator it;
110 JvmtiEnvBase *previous_env = NULL;
111 for (JvmtiEnvBase* env = it.first(); env != NULL; env = it.next(env)) {
112 previous_env = env;
113 }
114 if (previous_env == NULL) {
115 _head_environment = this;
116 } else {
117 previous_env->set_next_environment(this);
118 }
119 }
120
121 if (_globally_initialized == false) {
122 globally_initialize();
123 }
124 }
125
126 jvmtiPhase
127 JvmtiEnvBase::phase() {
128 // For the JVMTI environments possessed the can_generate_early_vmstart:
129 // replace JVMTI_PHASE_PRIMORDIAL with JVMTI_PHASE_START
130 if (_phase == JVMTI_PHASE_PRIMORDIAL &&
131 JvmtiExport::early_vmstart_recorded() &&
132 early_vmstart_env()) {
133 return JVMTI_PHASE_START;
134 }
135 return _phase; // Normal case
136 }
137
138 bool
139 JvmtiEnvBase::is_valid() {
140 jint value = 0;
141
142 // This object might not be a JvmtiEnvBase so we can't assume
143 // the _magic field is properly aligned. Get the value in a safe
144 // way and then check against JVMTI_MAGIC.
145
146 switch (sizeof(_magic)) {
147 case 2:
148 value = Bytes::get_native_u2((address)&_magic);
149 break;
150
151 case 4:
152 value = Bytes::get_native_u4((address)&_magic);
153 break;
154
155 case 8:
156 value = Bytes::get_native_u8((address)&_magic);
157 break;
158
159 default:
160 guarantee(false, "_magic field is an unexpected size");
161 }
162
163 return value == JVMTI_MAGIC;
164 }
165
166
167 bool
168 JvmtiEnvBase::use_version_1_0_semantics() {
169 int major, minor, micro;
170
171 JvmtiExport::decode_version_values(_version, &major, &minor, µ);
172 return major == 1 && minor == 0; // micro version doesn't matter here
173 }
174
175
176 bool
177 JvmtiEnvBase::use_version_1_1_semantics() {
178 int major, minor, micro;
179
180 JvmtiExport::decode_version_values(_version, &major, &minor, µ);
181 return major == 1 && minor == 1; // micro version doesn't matter here
182 }
183
184 bool
185 JvmtiEnvBase::use_version_1_2_semantics() {
186 int major, minor, micro;
187
188 JvmtiExport::decode_version_values(_version, &major, &minor, µ);
189 return major == 1 && minor == 2; // micro version doesn't matter here
190 }
191
192
193 JvmtiEnvBase::JvmtiEnvBase(jint version) : _env_event_enable() {
194 _version = version;
195 _env_local_storage = NULL;
196 _tag_map = NULL;
197 _native_method_prefix_count = 0;
198 _native_method_prefixes = NULL;
199 _next = NULL;
200 _class_file_load_hook_ever_enabled = false;
201
202 // Moot since ClassFileLoadHook not yet enabled.
203 // But "true" will give a more predictable ClassFileLoadHook behavior
204 // for environment creation during ClassFileLoadHook.
205 _is_retransformable = true;
206
207 // all callbacks initially NULL
208 memset(&_event_callbacks,0,sizeof(jvmtiEventCallbacks));
209
210 // all capabilities initially off
211 memset(&_current_capabilities, 0, sizeof(_current_capabilities));
212
213 // all prohibited capabilities initially off
214 memset(&_prohibited_capabilities, 0, sizeof(_prohibited_capabilities));
215
216 _magic = JVMTI_MAGIC;
217
218 JvmtiEventController::env_initialize((JvmtiEnv*)this);
219
220 #ifdef JVMTI_TRACE
221 _jvmti_external.functions = TraceJVMTI != NULL ? &jvmtiTrace_Interface : &jvmti_Interface;
222 #else
223 _jvmti_external.functions = &jvmti_Interface;
224 #endif
225 }
226
227
228 void
229 JvmtiEnvBase::dispose() {
230
231 #ifdef JVMTI_TRACE
232 JvmtiTrace::shutdown();
233 #endif
234
235 // Dispose of event info and let the event controller call us back
236 // in a locked state (env_dispose, below)
237 JvmtiEventController::env_dispose(this);
238 }
239
240 void
241 JvmtiEnvBase::env_dispose() {
242 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
243
244 // We have been entered with all events disabled on this environment.
245 // A race to re-enable events (by setting callbacks) is prevented by
246 // checking for a valid environment when setting callbacks (while
247 // holding the JvmtiThreadState_lock).
248
249 // Mark as invalid.
250 _magic = DISPOSED_MAGIC;
251
252 // Relinquish all capabilities.
253 jvmtiCapabilities *caps = get_capabilities();
254 JvmtiManageCapabilities::relinquish_capabilities(caps, caps, caps);
255
256 // Same situation as with events (see above)
257 set_native_method_prefixes(0, NULL);
258
259 JvmtiTagMap* tag_map_to_deallocate = _tag_map;
260 set_tag_map(NULL);
261 // A tag map can be big, deallocate it now
262 if (tag_map_to_deallocate != NULL) {
263 delete tag_map_to_deallocate;
264 }
265
266 _needs_clean_up = true;
267 }
268
269
270 JvmtiEnvBase::~JvmtiEnvBase() {
271 assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
272
273 // There is a small window of time during which the tag map of a
274 // disposed environment could have been reallocated.
275 // Make sure it is gone.
276 JvmtiTagMap* tag_map_to_deallocate = _tag_map;
277 set_tag_map(NULL);
278 // A tag map can be big, deallocate it now
279 if (tag_map_to_deallocate != NULL) {
280 delete tag_map_to_deallocate;
281 }
282
283 _magic = BAD_MAGIC;
284 }
285
286
287 void
288 JvmtiEnvBase::periodic_clean_up() {
289 assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
290
291 // JvmtiEnvBase reference is saved in JvmtiEnvThreadState. So
292 // clean up JvmtiThreadState before deleting JvmtiEnv pointer.
293 JvmtiThreadState::periodic_clean_up();
294
295 // Unlink all invalid environments from the list of environments
296 // and deallocate them
297 JvmtiEnvIterator it;
298 JvmtiEnvBase* previous_env = NULL;
299 JvmtiEnvBase* env = it.first();
300 while (env != NULL) {
301 if (env->is_valid()) {
302 previous_env = env;
303 env = it.next(env);
304 } else {
305 // This one isn't valid, remove it from the list and deallocate it
306 JvmtiEnvBase* defunct_env = env;
307 env = it.next(env);
308 if (previous_env == NULL) {
309 _head_environment = env;
310 } else {
311 previous_env->set_next_environment(env);
312 }
313 delete defunct_env;
314 }
315 }
316
317 }
318
319
320 void
321 JvmtiEnvBase::check_for_periodic_clean_up() {
322 assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
323
324 class ThreadInsideIterationClosure: public ThreadClosure {
325 private:
326 bool _inside;
327 public:
328 ThreadInsideIterationClosure() : _inside(false) {};
329
330 void do_thread(Thread* thread) {
331 _inside |= thread->is_inside_jvmti_env_iteration();
332 }
333
334 bool is_inside_jvmti_env_iteration() {
335 return _inside;
336 }
337 };
338
339 if (_needs_clean_up) {
340 // Check if we are currently iterating environment,
341 // deallocation should not occur if we are
342 ThreadInsideIterationClosure tiic;
343 Threads::threads_do(&tiic);
344 if (!tiic.is_inside_jvmti_env_iteration() &&
345 !is_inside_dying_thread_env_iteration()) {
346 _needs_clean_up = false;
347 JvmtiEnvBase::periodic_clean_up();
348 }
349 }
350 }
351
352
353 void
354 JvmtiEnvBase::record_first_time_class_file_load_hook_enabled() {
355 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(),
356 "sanity check");
357
358 if (!_class_file_load_hook_ever_enabled) {
359 _class_file_load_hook_ever_enabled = true;
360
361 if (get_capabilities()->can_retransform_classes) {
362 _is_retransformable = true;
363 } else {
364 _is_retransformable = false;
365
366 // cannot add retransform capability after ClassFileLoadHook has been enabled
367 get_prohibited_capabilities()->can_retransform_classes = 1;
368 }
369 }
370 }
371
372
373 void
374 JvmtiEnvBase::record_class_file_load_hook_enabled() {
375 if (!_class_file_load_hook_ever_enabled) {
376 if (Threads::number_of_threads() == 0) {
377 record_first_time_class_file_load_hook_enabled();
378 } else {
379 MutexLocker mu(JvmtiThreadState_lock);
380 record_first_time_class_file_load_hook_enabled();
381 }
382 }
383 }
384
385
386 jvmtiError
387 JvmtiEnvBase::set_native_method_prefixes(jint prefix_count, char** prefixes) {
388 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(),
389 "sanity check");
390
391 int old_prefix_count = get_native_method_prefix_count();
392 char **old_prefixes = get_native_method_prefixes();
393
394 // allocate and install the new prefixex
395 if (prefix_count == 0 || !is_valid()) {
396 _native_method_prefix_count = 0;
397 _native_method_prefixes = NULL;
398 } else {
399 // there are prefixes, allocate an array to hold them, and fill it
400 char** new_prefixes = (char**)os::malloc((prefix_count) * sizeof(char*), mtInternal);
401 if (new_prefixes == NULL) {
402 return JVMTI_ERROR_OUT_OF_MEMORY;
403 }
404 for (int i = 0; i < prefix_count; i++) {
405 char* prefix = 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_NULL_POINTER;
412 }
413 prefix = os::strdup(prefixes[i]);
414 if (prefix == NULL) {
415 for (int j = 0; j < (i-1); j++) {
416 os::free(new_prefixes[j]);
417 }
418 os::free(new_prefixes);
419 return JVMTI_ERROR_OUT_OF_MEMORY;
420 }
421 new_prefixes[i] = prefix;
422 }
423 _native_method_prefix_count = prefix_count;
424 _native_method_prefixes = new_prefixes;
425 }
426
427 // now that we know the new prefixes have been successfully installed we can
428 // safely remove the old ones
429 if (old_prefix_count != 0) {
430 for (int i = 0; i < old_prefix_count; i++) {
431 os::free(old_prefixes[i]);
432 }
433 os::free(old_prefixes);
434 }
435
436 return JVMTI_ERROR_NONE;
437 }
438
439
440 // Collect all the prefixes which have been set in any JVM TI environments
441 // by the SetNativeMethodPrefix(es) functions. Be sure to maintain the
442 // order of environments and the order of prefixes within each environment.
443 // Return in a resource allocated array.
444 char**
445 JvmtiEnvBase::get_all_native_method_prefixes(int* count_ptr) {
446 assert(Threads::number_of_threads() == 0 ||
447 SafepointSynchronize::is_at_safepoint() ||
448 JvmtiThreadState_lock->is_locked(),
449 "sanity check");
450
451 int total_count = 0;
452 GrowableArray<char*>* prefix_array =new GrowableArray<char*>(5);
453
454 JvmtiEnvIterator it;
455 for (JvmtiEnvBase* env = it.first(); env != NULL; env = it.next(env)) {
456 int prefix_count = env->get_native_method_prefix_count();
457 char** prefixes = env->get_native_method_prefixes();
458 for (int j = 0; j < prefix_count; j++) {
459 // retrieve a prefix and so that it is safe against asynchronous changes
460 // copy it into the resource area
461 char* prefix = prefixes[j];
462 char* prefix_copy = NEW_RESOURCE_ARRAY(char, strlen(prefix)+1);
463 strcpy(prefix_copy, prefix);
464 prefix_array->at_put_grow(total_count++, prefix_copy);
465 }
466 }
467
468 char** all_prefixes = NEW_RESOURCE_ARRAY(char*, total_count);
469 char** p = all_prefixes;
470 for (int i = 0; i < total_count; ++i) {
471 *p++ = prefix_array->at(i);
472 }
473 *count_ptr = total_count;
474 return all_prefixes;
475 }
476
477 void
478 JvmtiEnvBase::set_event_callbacks(const jvmtiEventCallbacks* callbacks,
479 jint size_of_callbacks) {
480 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
481
482 size_t byte_cnt = sizeof(jvmtiEventCallbacks);
483
484 // clear in either case to be sure we got any gap between sizes
485 memset(&_event_callbacks, 0, byte_cnt);
486
487 // Now that JvmtiThreadState_lock is held, prevent a possible race condition where events
488 // are re-enabled by a call to set event callbacks where the DisposeEnvironment
489 // occurs after the boiler-plate environment check and before the lock is acquired.
490 if (callbacks != NULL && is_valid()) {
491 if (size_of_callbacks < (jint)byte_cnt) {
492 byte_cnt = size_of_callbacks;
493 }
494 memcpy(&_event_callbacks, callbacks, byte_cnt);
495 }
496 }
497
498
499 // In the fullness of time, all users of the method should instead
500 // directly use allocate, besides being cleaner and faster, this will
501 // mean much better out of memory handling
502 unsigned char *
503 JvmtiEnvBase::jvmtiMalloc(jlong size) {
504 unsigned char* mem = NULL;
505 jvmtiError result = allocate(size, &mem);
506 assert(result == JVMTI_ERROR_NONE, "Allocate failed");
507 return mem;
508 }
509
510
511 // Handle management
512
513 jobject JvmtiEnvBase::jni_reference(Handle hndl) {
514 return JNIHandles::make_local(hndl());
515 }
516
517 jobject JvmtiEnvBase::jni_reference(JavaThread *thread, Handle hndl) {
518 return JNIHandles::make_local(thread, hndl());
519 }
520
521 void JvmtiEnvBase::destroy_jni_reference(jobject jobj) {
522 JNIHandles::destroy_local(jobj);
523 }
524
525 void JvmtiEnvBase::destroy_jni_reference(JavaThread *thread, jobject jobj) {
526 JNIHandles::destroy_local(jobj); // thread is unused.
527 }
528
529 //
530 // Threads
531 //
532
533 jobject *
534 JvmtiEnvBase::new_jobjectArray(int length, Handle *handles) {
535 if (length == 0) {
536 return NULL;
537 }
538
539 jobject *objArray = (jobject *) jvmtiMalloc(sizeof(jobject) * length);
540 NULL_CHECK(objArray, NULL);
541
542 for (int i=0; i<length; i++) {
543 objArray[i] = jni_reference(handles[i]);
544 }
545 return objArray;
546 }
547
548 jthread *
549 JvmtiEnvBase::new_jthreadArray(int length, Handle *handles) {
550 return (jthread *) new_jobjectArray(length,handles);
551 }
552
553 jthreadGroup *
554 JvmtiEnvBase::new_jthreadGroupArray(int length, Handle *handles) {
555 return (jthreadGroup *) new_jobjectArray(length,handles);
556 }
557
558 // return the vframe on the specified thread and depth, NULL if no such frame
559 vframe*
560 JvmtiEnvBase::vframeFor(JavaThread* java_thread, jint depth) {
561 if (!java_thread->has_last_Java_frame()) {
562 return NULL;
563 }
564 RegisterMap reg_map(java_thread);
565 vframe *vf = java_thread->last_java_vframe(®_map);
566 int d = 0;
567 while ((vf != NULL) && (d < depth)) {
568 vf = vf->java_sender();
569 d++;
570 }
571 return vf;
572 }
573
574
575 //
576 // utilities: JNI objects
577 //
578
579
580 jclass
581 JvmtiEnvBase::get_jni_class_non_null(Klass* k) {
582 assert(k != NULL, "k != NULL");
583 Thread *thread = Thread::current();
584 return (jclass)jni_reference(Handle(thread, k->java_mirror()));
585 }
586
587 //
588 // Field Information
589 //
590
591 bool
592 JvmtiEnvBase::get_field_descriptor(Klass* k, jfieldID field, fieldDescriptor* fd) {
593 if (!jfieldIDWorkaround::is_valid_jfieldID(k, field)) {
594 return false;
595 }
596 bool found = false;
597 if (jfieldIDWorkaround::is_static_jfieldID(field)) {
598 JNIid* id = jfieldIDWorkaround::from_static_jfieldID(field);
599 found = id->find_local_field(fd);
600 } else {
601 // Non-static field. The fieldID is really the offset of the field within the object.
602 int offset = jfieldIDWorkaround::from_instance_jfieldID(k, field);
603 found = InstanceKlass::cast(k)->find_field_from_offset(offset, false, fd);
604 }
605 return found;
606 }
607
608 //
609 // Object Monitor Information
610 //
611
612 //
613 // Count the number of objects for a lightweight monitor. The hobj
614 // parameter is object that owns the monitor so this routine will
615 // count the number of times the same object was locked by frames
616 // in java_thread.
617 //
618 jint
619 JvmtiEnvBase::count_locked_objects(JavaThread *java_thread, Handle hobj) {
620 jint ret = 0;
621 if (!java_thread->has_last_Java_frame()) {
622 return ret; // no Java frames so no monitors
623 }
624
625 ResourceMark rm;
626 HandleMark hm;
627 RegisterMap reg_map(java_thread);
628
629 for(javaVFrame *jvf=java_thread->last_java_vframe(®_map); jvf != NULL;
630 jvf = jvf->java_sender()) {
631 GrowableArray<MonitorInfo*>* mons = jvf->monitors();
632 if (!mons->is_empty()) {
633 for (int i = 0; i < mons->length(); i++) {
634 MonitorInfo *mi = mons->at(i);
635 if (mi->owner_is_scalar_replaced()) continue;
636
637 // see if owner of the monitor is our object
638 if (mi->owner() != NULL && mi->owner() == hobj()) {
639 ret++;
640 }
641 }
642 }
643 }
644 return ret;
645 }
646
647
648
649 jvmtiError
650 JvmtiEnvBase::get_current_contended_monitor(JavaThread *calling_thread, JavaThread *java_thread, jobject *monitor_ptr) {
651 JavaThread *current_jt = JavaThread::current();
652 assert(current_jt == java_thread ||
653 current_jt == java_thread->active_handshaker(),
654 "call by myself or at direct handshake");
655 oop obj = NULL;
656 // The ObjectMonitor* can't be async deflated since we are either
657 // at a safepoint or the calling thread is operating on itself so
658 // it cannot leave the underlying wait()/enter() call.
659 ObjectMonitor *mon = java_thread->current_waiting_monitor();
660 if (mon == NULL) {
661 // thread is not doing an Object.wait() call
662 mon = java_thread->current_pending_monitor();
663 if (mon != NULL) {
664 // The thread is trying to enter() an ObjectMonitor.
665 obj = (oop)mon->object();
666 assert(obj != NULL, "ObjectMonitor should have a valid object!");
667 }
668 // implied else: no contended ObjectMonitor
669 } else {
670 // thread is doing an Object.wait() call
671 obj = (oop)mon->object();
672 assert(obj != NULL, "Object.wait() should have an object");
673 }
674
675 if (obj == NULL) {
676 *monitor_ptr = NULL;
677 } else {
678 HandleMark hm;
679 Handle hobj(current_jt, obj);
680 *monitor_ptr = jni_reference(calling_thread, hobj);
681 }
682 return JVMTI_ERROR_NONE;
683 }
684
685
686 jvmtiError
687 JvmtiEnvBase::get_owned_monitors(JavaThread *calling_thread, JavaThread* java_thread,
688 GrowableArray<jvmtiMonitorStackDepthInfo*> *owned_monitors_list) {
689 jvmtiError err = JVMTI_ERROR_NONE;
690 JavaThread *current_jt = JavaThread::current();
691 assert(current_jt == java_thread ||
692 current_jt == java_thread->active_handshaker(),
693 "call by myself or at direct handshake");
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 // The ObjectMonitor* can't be async deflated since we are either
737 // at a safepoint or the calling thread is operating on itself so
738 // it cannot leave the underlying wait() call.
739 // Save object of current wait() call (if any) for later comparison.
740 ObjectMonitor *mon = java_thread->current_waiting_monitor();
741 if (mon != NULL) {
742 wait_obj = (oop)mon->object();
743 }
744 }
745 oop pending_obj = NULL;
746 {
747 // The ObjectMonitor* can't be async deflated since we are either
748 // at a safepoint or the calling thread is operating on itself so
749 // it cannot leave the underlying enter() call.
750 // Save object of current enter() call (if any) for later comparison.
751 ObjectMonitor *mon = java_thread->current_pending_monitor();
752 if (mon != NULL) {
753 pending_obj = (oop)mon->object();
754 }
755 }
756
757 for (int i = 0; i < mons->length(); i++) {
758 MonitorInfo *mi = mons->at(i);
759
760 if (mi->owner_is_scalar_replaced()) continue;
761
762 oop obj = mi->owner();
763 if (obj == NULL) {
764 // this monitor doesn't have an owning object so skip it
765 continue;
766 }
767
768 if (wait_obj == obj) {
769 // the thread is waiting on this monitor so it isn't really owned
770 continue;
771 }
772
773 if (pending_obj == obj) {
774 // the thread is pending on this monitor so it isn't really owned
775 continue;
776 }
777
778 if (owned_monitors_list->length() > 0) {
779 // Our list has at least one object on it so we have to check
780 // for recursive object locking
781 bool found = false;
782 for (int j = 0; j < owned_monitors_list->length(); j++) {
783 jobject jobj = ((jvmtiMonitorStackDepthInfo*)owned_monitors_list->at(j))->monitor;
784 oop check = JNIHandles::resolve(jobj);
785 if (check == obj) {
786 found = true; // we found the object
787 break;
788 }
789 }
790
791 if (found) {
792 // already have this object so don't include it
793 continue;
794 }
795 }
796
797 // add the owning object to our list
798 jvmtiMonitorStackDepthInfo *jmsdi;
799 err = allocate(sizeof(jvmtiMonitorStackDepthInfo), (unsigned char **)&jmsdi);
800 if (err != JVMTI_ERROR_NONE) {
801 return err;
802 }
803 Handle hobj(Thread::current(), obj);
804 jmsdi->monitor = jni_reference(calling_thread, hobj);
805 jmsdi->stack_depth = stack_depth;
806 owned_monitors_list->append(jmsdi);
807 }
808
809 return err;
810 }
811
812 jvmtiError
813 JvmtiEnvBase::get_stack_trace(JavaThread *java_thread,
814 jint start_depth, jint max_count,
815 jvmtiFrameInfo* frame_buffer, jint* count_ptr) {
816 #ifdef ASSERT
817 uint32_t debug_bits = 0;
818 #endif
819 assert((SafepointSynchronize::is_at_safepoint() ||
820 java_thread->is_thread_fully_suspended(false, &debug_bits)),
821 "at safepoint or target thread is suspended");
822 int count = 0;
823 if (java_thread->has_last_Java_frame()) {
824 RegisterMap reg_map(java_thread);
825 Thread* current_thread = Thread::current();
826 ResourceMark rm(current_thread);
827 javaVFrame *jvf = java_thread->last_java_vframe(®_map);
828 HandleMark hm(current_thread);
829 if (start_depth != 0) {
830 if (start_depth > 0) {
831 for (int j = 0; j < start_depth && jvf != NULL; j++) {
832 jvf = jvf->java_sender();
833 }
834 if (jvf == NULL) {
835 // start_depth is deeper than the stack depth
836 return JVMTI_ERROR_ILLEGAL_ARGUMENT;
837 }
838 } else { // start_depth < 0
839 // we are referencing the starting depth based on the oldest
840 // part of the stack.
841 // optimize to limit the number of times that java_sender() is called
842 javaVFrame *jvf_cursor = jvf;
843 javaVFrame *jvf_prev = NULL;
844 javaVFrame *jvf_prev_prev = NULL;
845 int j = 0;
846 while (jvf_cursor != NULL) {
847 jvf_prev_prev = jvf_prev;
848 jvf_prev = jvf_cursor;
849 for (j = 0; j > start_depth && jvf_cursor != NULL; j--) {
850 jvf_cursor = jvf_cursor->java_sender();
851 }
852 }
853 if (j == start_depth) {
854 // previous pointer is exactly where we want to start
855 jvf = jvf_prev;
856 } else {
857 // we need to back up further to get to the right place
858 if (jvf_prev_prev == NULL) {
859 // the -start_depth is greater than the stack depth
860 return JVMTI_ERROR_ILLEGAL_ARGUMENT;
861 }
862 // j now is the number of frames on the stack starting with
863 // jvf_prev, we start from jvf_prev_prev and move older on
864 // the stack that many, the result is -start_depth frames
865 // remaining.
866 jvf = jvf_prev_prev;
867 for (; j < 0; j++) {
868 jvf = jvf->java_sender();
869 }
870 }
871 }
872 }
873 for (; count < max_count && jvf != NULL; count++) {
874 frame_buffer[count].method = jvf->method()->jmethod_id();
875 frame_buffer[count].location = (jvf->method()->is_native() ? -1 : jvf->bci());
876 jvf = jvf->java_sender();
877 }
878 } else {
879 if (start_depth != 0) {
880 // no frames and there is a starting depth
881 return JVMTI_ERROR_ILLEGAL_ARGUMENT;
882 }
883 }
884 *count_ptr = count;
885 return JVMTI_ERROR_NONE;
886 }
887
888 jvmtiError
889 JvmtiEnvBase::get_frame_count(JvmtiThreadState *state, jint *count_ptr) {
890 assert((state != NULL),
891 "JavaThread should create JvmtiThreadState before calling this method");
892 *count_ptr = state->count_frames();
893 return JVMTI_ERROR_NONE;
894 }
895
896 jvmtiError
897 JvmtiEnvBase::get_frame_location(JavaThread *java_thread, jint depth,
898 jmethodID* method_ptr, jlocation* location_ptr) {
899 #ifdef ASSERT
900 uint32_t debug_bits = 0;
901 #endif
902 assert((SafepointSynchronize::is_at_safepoint() ||
903 java_thread->is_thread_fully_suspended(false, &debug_bits)),
904 "at safepoint or target thread is suspended");
905 Thread* current_thread = Thread::current();
906 ResourceMark rm(current_thread);
907
908 vframe *vf = vframeFor(java_thread, depth);
909 if (vf == NULL) {
910 return JVMTI_ERROR_NO_MORE_FRAMES;
911 }
912
913 // vframeFor should return a java frame. If it doesn't
914 // it means we've got an internal error and we return the
915 // error in product mode. In debug mode we will instead
916 // attempt to cast the vframe to a javaVFrame and will
917 // cause an assertion/crash to allow further diagnosis.
918 #ifdef PRODUCT
919 if (!vf->is_java_frame()) {
920 return JVMTI_ERROR_INTERNAL;
921 }
922 #endif
923
924 HandleMark hm(current_thread);
925 javaVFrame *jvf = javaVFrame::cast(vf);
926 Method* method = jvf->method();
927 if (method->is_native()) {
928 *location_ptr = -1;
929 } else {
930 *location_ptr = jvf->bci();
931 }
932 *method_ptr = method->jmethod_id();
933
934 return JVMTI_ERROR_NONE;
935 }
936
937
938 jvmtiError
939 JvmtiEnvBase::get_object_monitor_usage(JavaThread* calling_thread, jobject object, jvmtiMonitorUsage* info_ptr) {
940 HandleMark hm;
941 Handle hobj;
942
943 Thread* current_thread = Thread::current();
944 bool at_safepoint = SafepointSynchronize::is_at_safepoint();
945
946 // Check arguments
947 {
948 oop mirror = JNIHandles::resolve_external_guard(object);
949 NULL_CHECK(mirror, JVMTI_ERROR_INVALID_OBJECT);
950 NULL_CHECK(info_ptr, JVMTI_ERROR_NULL_POINTER);
951
952 hobj = Handle(current_thread, mirror);
953 }
954
955 JavaThread *owning_thread = NULL;
956 ObjectMonitor *mon = NULL;
957 jvmtiMonitorUsage ret = {
958 NULL, 0, 0, NULL, 0, NULL
959 };
960
961 uint32_t debug_bits = 0;
962 // first derive the object's owner and entry_count (if any)
963 {
964 // Revoke any biases before querying the mark word
965 if (at_safepoint) {
966 BiasedLocking::revoke_at_safepoint(hobj);
967 } else {
968 BiasedLocking::revoke(hobj, calling_thread);
969 }
970
971 address owner = NULL;
972 {
973 markWord mark = hobj()->mark();
974
975 if (!mark.has_monitor()) {
976 // this object has a lightweight monitor
977
978 if (mark.has_locker()) {
979 owner = (address)mark.locker(); // save the address of the Lock word
980 }
981 // implied else: no owner
982 } else {
983 // this object has a heavyweight monitor
984 mon = mark.monitor();
985
986 // The owner field of a heavyweight monitor may be NULL for no
987 // owner, a JavaThread * or it may still be the address of the
988 // Lock word in a JavaThread's stack. A monitor can be inflated
989 // by a non-owning JavaThread, but only the owning JavaThread
990 // can change the owner field from the Lock word to the
991 // JavaThread * and it may not have done that yet.
992 owner = (address)mon->owner();
993 }
994 }
995
996 if (owner != NULL) {
997 // Use current thread since function can be called from a
998 // JavaThread or the VMThread.
999 ThreadsListHandle tlh;
1000 // This monitor is owned so we have to find the owning JavaThread.
1001 owning_thread = Threads::owning_thread_from_monitor_owner(tlh.list(), owner);
1002 // Cannot assume (owning_thread != NULL) here because this function
1003 // may not have been called at a safepoint and the owning_thread
1004 // might not be suspended.
1005 if (owning_thread != NULL) {
1006 // The monitor's owner either has to be the current thread, at safepoint
1007 // or it has to be suspended. Any of these conditions will prevent both
1008 // contending and waiting threads from modifying the state of
1009 // the monitor.
1010 if (!at_safepoint && !owning_thread->is_thread_fully_suspended(true, &debug_bits)) {
1011 // Don't worry! This return of JVMTI_ERROR_THREAD_NOT_SUSPENDED
1012 // will not make it back to the JVM/TI agent. The error code will
1013 // get intercepted in JvmtiEnv::GetObjectMonitorUsage() which
1014 // will retry the call via a VM_GetObjectMonitorUsage VM op.
1015 return JVMTI_ERROR_THREAD_NOT_SUSPENDED;
1016 }
1017 HandleMark hm;
1018 Handle th(current_thread, owning_thread->threadObj());
1019 ret.owner = (jthread)jni_reference(calling_thread, th);
1020 }
1021 // implied else: no owner
1022 } // ThreadsListHandle is destroyed here.
1023
1024 if (owning_thread != NULL) { // monitor is owned
1025 // The recursions field of a monitor does not reflect recursions
1026 // as lightweight locks before inflating the monitor are not included.
1027 // We have to count the number of recursive monitor entries the hard way.
1028 // We pass a handle to survive any GCs along the way.
1029 ResourceMark rm;
1030 ret.entry_count = count_locked_objects(owning_thread, hobj);
1031 }
1032 // implied else: entry_count == 0
1033 }
1034
1035 jint nWant = 0, nWait = 0;
1036 if (mon != NULL) {
1037 // this object has a heavyweight monitor
1038 nWant = mon->contentions(); // # of threads contending for monitor
1039 nWait = mon->waiters(); // # of threads in Object.wait()
1040 ret.waiter_count = nWant + nWait;
1041 ret.notify_waiter_count = nWait;
1042 } else {
1043 // this object has a lightweight monitor
1044 ret.waiter_count = 0;
1045 ret.notify_waiter_count = 0;
1046 }
1047
1048 // Allocate memory for heavyweight and lightweight monitor.
1049 jvmtiError err;
1050 err = allocate(ret.waiter_count * sizeof(jthread *), (unsigned char**)&ret.waiters);
1051 if (err != JVMTI_ERROR_NONE) {
1052 return err;
1053 }
1054 err = allocate(ret.notify_waiter_count * sizeof(jthread *),
1055 (unsigned char**)&ret.notify_waiters);
1056 if (err != JVMTI_ERROR_NONE) {
1057 deallocate((unsigned char*)ret.waiters);
1058 return err;
1059 }
1060
1061 // now derive the rest of the fields
1062 if (mon != NULL) {
1063 // this object has a heavyweight monitor
1064
1065 // Number of waiters may actually be less than the waiter count.
1066 // So NULL out memory so that unused memory will be NULL.
1067 memset(ret.waiters, 0, ret.waiter_count * sizeof(jthread *));
1068 memset(ret.notify_waiters, 0, ret.notify_waiter_count * sizeof(jthread *));
1069
1070 if (ret.waiter_count > 0) {
1071 // we have contending and/or waiting threads
1072 HandleMark hm;
1073 // Use current thread since function can be called from a
1074 // JavaThread or the VMThread.
1075 ThreadsListHandle tlh;
1076 if (nWant > 0) {
1077 // we have contending threads
1078 ResourceMark rm;
1079 // get_pending_threads returns only java thread so we do not need to
1080 // check for non java threads.
1081 GrowableArray<JavaThread*>* wantList = Threads::get_pending_threads(tlh.list(), nWant, (address)mon);
1082 if (wantList->length() < nWant) {
1083 // robustness: the pending list has gotten smaller
1084 nWant = wantList->length();
1085 }
1086 for (int i = 0; i < nWant; i++) {
1087 JavaThread *pending_thread = wantList->at(i);
1088 // If the monitor has no owner, then a non-suspended contending
1089 // thread could potentially change the state of the monitor by
1090 // entering it. The JVM/TI spec doesn't allow this.
1091 if (owning_thread == NULL && !at_safepoint &&
1092 !pending_thread->is_thread_fully_suspended(true, &debug_bits)) {
1093 if (ret.owner != NULL) {
1094 destroy_jni_reference(calling_thread, ret.owner);
1095 }
1096 for (int j = 0; j < i; j++) {
1097 destroy_jni_reference(calling_thread, ret.waiters[j]);
1098 }
1099 deallocate((unsigned char*)ret.waiters);
1100 deallocate((unsigned char*)ret.notify_waiters);
1101 return JVMTI_ERROR_THREAD_NOT_SUSPENDED;
1102 }
1103 Handle th(current_thread, pending_thread->threadObj());
1104 ret.waiters[i] = (jthread)jni_reference(calling_thread, th);
1105 }
1106 }
1107 if (nWait > 0) {
1108 // we have threads in Object.wait()
1109 int offset = nWant; // add after any contending threads
1110 ObjectWaiter *waiter = mon->first_waiter();
1111 for (int i = 0, j = 0; i < nWait; i++) {
1112 if (waiter == NULL) {
1113 // robustness: the waiting list has gotten smaller
1114 nWait = j;
1115 break;
1116 }
1117 Thread *t = mon->thread_of_waiter(waiter);
1118 if (t != NULL && t->is_Java_thread()) {
1119 JavaThread *wjava_thread = (JavaThread *)t;
1120 // If the thread was found on the ObjectWaiter list, then
1121 // it has not been notified. This thread can't change the
1122 // state of the monitor so it doesn't need to be suspended.
1123 Handle th(current_thread, wjava_thread->threadObj());
1124 ret.waiters[offset + j] = (jthread)jni_reference(calling_thread, th);
1125 ret.notify_waiters[j++] = (jthread)jni_reference(calling_thread, th);
1126 }
1127 waiter = mon->next_waiter(waiter);
1128 }
1129 }
1130 } // ThreadsListHandle is destroyed here.
1131
1132 // Adjust count. nWant and nWait count values may be less than original.
1133 ret.waiter_count = nWant + nWait;
1134 ret.notify_waiter_count = nWait;
1135 } else {
1136 // this object has a lightweight monitor and we have nothing more
1137 // to do here because the defaults are just fine.
1138 }
1139
1140 // we don't update return parameter unless everything worked
1141 *info_ptr = ret;
1142
1143 return JVMTI_ERROR_NONE;
1144 }
1145
1146 ResourceTracker::ResourceTracker(JvmtiEnv* env) {
1147 _env = env;
1148 _allocations = new (ResourceObj::C_HEAP, mtServiceability) GrowableArray<unsigned char*>(20, mtServiceability);
1149 _failed = false;
1150 }
1151 ResourceTracker::~ResourceTracker() {
1152 if (_failed) {
1153 for (int i=0; i<_allocations->length(); i++) {
1154 _env->deallocate(_allocations->at(i));
1155 }
1156 }
1157 delete _allocations;
1158 }
1159
1160 jvmtiError ResourceTracker::allocate(jlong size, unsigned char** mem_ptr) {
1161 unsigned char *ptr;
1162 jvmtiError err = _env->allocate(size, &ptr);
1163 if (err == JVMTI_ERROR_NONE) {
1164 _allocations->append(ptr);
1165 *mem_ptr = ptr;
1166 } else {
1167 *mem_ptr = NULL;
1168 _failed = true;
1169 }
1170 return err;
1171 }
1172
1173 unsigned char* ResourceTracker::allocate(jlong size) {
1174 unsigned char* ptr;
1175 allocate(size, &ptr);
1176 return ptr;
1177 }
1178
1179 char* ResourceTracker::strdup(const char* str) {
1180 char *dup_str = (char*)allocate(strlen(str)+1);
1181 if (dup_str != NULL) {
1182 strcpy(dup_str, str);
1183 }
1184 return dup_str;
1185 }
1186
1187 struct StackInfoNode {
1188 struct StackInfoNode *next;
1189 jvmtiStackInfo info;
1190 };
1191
1192 // Create a jvmtiStackInfo inside a linked list node and create a
1193 // buffer for the frame information, both allocated as resource objects.
1194 // Fill in both the jvmtiStackInfo and the jvmtiFrameInfo.
1195 // Note that either or both of thr and thread_oop
1196 // may be null if the thread is new or has exited.
1197 void
1198 VM_GetMultipleStackTraces::fill_frames(jthread jt, JavaThread *thr, oop thread_oop) {
1199 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
1200
1201 jint state = 0;
1202 struct StackInfoNode *node = NEW_RESOURCE_OBJ(struct StackInfoNode);
1203 jvmtiStackInfo *infop = &(node->info);
1204 node->next = head();
1205 set_head(node);
1206 infop->frame_count = 0;
1207 infop->thread = jt;
1208
1209 if (thread_oop != NULL) {
1210 // get most state bits
1211 state = (jint)java_lang_Thread::get_thread_status(thread_oop);
1212 }
1213
1214 if (thr != NULL) { // add more state bits if there is a JavaThead to query
1215 // same as is_being_ext_suspended() but without locking
1216 if (thr->is_ext_suspended() || thr->is_external_suspend()) {
1217 state |= JVMTI_THREAD_STATE_SUSPENDED;
1218 }
1219 JavaThreadState jts = thr->thread_state();
1220 if (jts == _thread_in_native) {
1221 state |= JVMTI_THREAD_STATE_IN_NATIVE;
1222 }
1223 if (thr->is_interrupted(false)) {
1224 state |= JVMTI_THREAD_STATE_INTERRUPTED;
1225 }
1226 }
1227 infop->state = state;
1228
1229 if (thr != NULL && (state & JVMTI_THREAD_STATE_ALIVE) != 0) {
1230 infop->frame_buffer = NEW_RESOURCE_ARRAY(jvmtiFrameInfo, max_frame_count());
1231 env()->get_stack_trace(thr, 0, max_frame_count(),
1232 infop->frame_buffer, &(infop->frame_count));
1233 } else {
1234 infop->frame_buffer = NULL;
1235 infop->frame_count = 0;
1236 }
1237 _frame_count_total += infop->frame_count;
1238 }
1239
1240 // Based on the stack information in the linked list, allocate memory
1241 // block to return and fill it from the info in the linked list.
1242 void
1243 VM_GetMultipleStackTraces::allocate_and_fill_stacks(jint thread_count) {
1244 // do I need to worry about alignment issues?
1245 jlong alloc_size = thread_count * sizeof(jvmtiStackInfo)
1246 + _frame_count_total * sizeof(jvmtiFrameInfo);
1247 env()->allocate(alloc_size, (unsigned char **)&_stack_info);
1248
1249 // pointers to move through the newly allocated space as it is filled in
1250 jvmtiStackInfo *si = _stack_info + thread_count; // bottom of stack info
1251 jvmtiFrameInfo *fi = (jvmtiFrameInfo *)si; // is the top of frame info
1252
1253 // copy information in resource area into allocated buffer
1254 // insert stack info backwards since linked list is backwards
1255 // insert frame info forwards
1256 // walk the StackInfoNodes
1257 for (struct StackInfoNode *sin = head(); sin != NULL; sin = sin->next) {
1258 jint frame_count = sin->info.frame_count;
1259 size_t frames_size = frame_count * sizeof(jvmtiFrameInfo);
1260 --si;
1261 memcpy(si, &(sin->info), sizeof(jvmtiStackInfo));
1262 if (frames_size == 0) {
1263 si->frame_buffer = NULL;
1264 } else {
1265 memcpy(fi, sin->info.frame_buffer, frames_size);
1266 si->frame_buffer = fi; // point to the new allocated copy of the frames
1267 fi += frame_count;
1268 }
1269 }
1270 assert(si == _stack_info, "the last copied stack info must be the first record");
1271 assert((unsigned char *)fi == ((unsigned char *)_stack_info) + alloc_size,
1272 "the last copied frame info must be the last record");
1273 }
1274
1275
1276 void
1277 VM_GetThreadListStackTraces::doit() {
1278 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
1279
1280 ResourceMark rm;
1281 ThreadsListHandle tlh;
1282 for (int i = 0; i < _thread_count; ++i) {
1283 jthread jt = _thread_list[i];
1284 JavaThread* java_thread = NULL;
1285 oop thread_oop = NULL;
1286 jvmtiError err = JvmtiExport::cv_external_thread_to_JavaThread(tlh.list(), jt, &java_thread, &thread_oop);
1287 if (err != JVMTI_ERROR_NONE) {
1288 // We got an error code so we don't have a JavaThread *, but
1289 // only return an error from here if we didn't get a valid
1290 // thread_oop.
1291 if (thread_oop == NULL) {
1292 set_result(err);
1293 return;
1294 }
1295 // We have a valid thread_oop.
1296 }
1297 fill_frames(jt, java_thread, thread_oop);
1298 }
1299 allocate_and_fill_stacks(_thread_count);
1300 }
1301
1302 void
1303 VM_GetAllStackTraces::doit() {
1304 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
1305
1306 ResourceMark rm;
1307 _final_thread_count = 0;
1308 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *jt = jtiwh.next(); ) {
1309 oop thread_oop = jt->threadObj();
1310 if (thread_oop != NULL &&
1311 !jt->is_exiting() &&
1312 java_lang_Thread::is_alive(thread_oop) &&
1313 !jt->is_hidden_from_external_view()) {
1314 ++_final_thread_count;
1315 // Handle block of the calling thread is used to create local refs.
1316 fill_frames((jthread)JNIHandles::make_local(_calling_thread, thread_oop),
1317 jt, thread_oop);
1318 }
1319 }
1320 allocate_and_fill_stacks(_final_thread_count);
1321 }
1322
1323 // Verifies that the top frame is a java frame in an expected state.
1324 // Deoptimizes frame if needed.
1325 // Checks that the frame method signature matches the return type (tos).
1326 // HandleMark must be defined in the caller only.
1327 // It is to keep a ret_ob_h handle alive after return to the caller.
1328 jvmtiError
1329 JvmtiEnvBase::check_top_frame(JavaThread* current_thread, JavaThread* java_thread,
1330 jvalue value, TosState tos, Handle* ret_ob_h) {
1331 ResourceMark rm(current_thread);
1332
1333 vframe *vf = vframeFor(java_thread, 0);
1334 NULL_CHECK(vf, JVMTI_ERROR_NO_MORE_FRAMES);
1335
1336 javaVFrame *jvf = (javaVFrame*) vf;
1337 if (!vf->is_java_frame() || jvf->method()->is_native()) {
1338 return JVMTI_ERROR_OPAQUE_FRAME;
1339 }
1340
1341 // If the frame is a compiled one, need to deoptimize it.
1342 if (vf->is_compiled_frame()) {
1343 if (!vf->fr().can_be_deoptimized()) {
1344 return JVMTI_ERROR_OPAQUE_FRAME;
1345 }
1346 Deoptimization::deoptimize_frame(java_thread, jvf->fr().id());
1347 }
1348
1349 // Get information about method return type
1350 Symbol* signature = jvf->method()->signature();
1351
1352 ResultTypeFinder rtf(signature);
1353 TosState fr_tos = as_TosState(rtf.type());
1354 if (fr_tos != tos) {
1355 if (tos != itos || (fr_tos != btos && fr_tos != ztos && fr_tos != ctos && fr_tos != stos)) {
1356 return JVMTI_ERROR_TYPE_MISMATCH;
1357 }
1358 }
1359
1360 // Check that the jobject class matches the return type signature.
1361 jobject jobj = value.l;
1362 if (tos == atos && jobj != NULL) { // NULL reference is allowed
1363 Handle ob_h(current_thread, JNIHandles::resolve_external_guard(jobj));
1364 NULL_CHECK(ob_h, JVMTI_ERROR_INVALID_OBJECT);
1365 Klass* ob_k = ob_h()->klass();
1366 NULL_CHECK(ob_k, JVMTI_ERROR_INVALID_OBJECT);
1367
1368 // Method return type signature.
1369 char* ty_sign = 1 + strchr(signature->as_C_string(), JVM_SIGNATURE_ENDFUNC);
1370
1371 if (!VM_GetOrSetLocal::is_assignable(ty_sign, ob_k, current_thread)) {
1372 return JVMTI_ERROR_TYPE_MISMATCH;
1373 }
1374 *ret_ob_h = ob_h;
1375 }
1376 return JVMTI_ERROR_NONE;
1377 } /* end check_top_frame */
1378
1379
1380 // ForceEarlyReturn<type> follows the PopFrame approach in many aspects.
1381 // Main difference is on the last stage in the interpreter.
1382 // The PopFrame stops method execution to continue execution
1383 // from the same method call instruction.
1384 // The ForceEarlyReturn forces return from method so the execution
1385 // continues at the bytecode following the method call.
1386
1387 // Threads_lock NOT held, java_thread not protected by lock
1388 // java_thread - pre-checked
1389
1390 jvmtiError
1391 JvmtiEnvBase::force_early_return(JavaThread* java_thread, jvalue value, TosState tos) {
1392 JavaThread* current_thread = JavaThread::current();
1393 HandleMark hm(current_thread);
1394 uint32_t debug_bits = 0;
1395
1396 // retrieve or create the state
1397 JvmtiThreadState* state = JvmtiThreadState::state_for(java_thread);
1398 if (state == NULL) {
1399 return JVMTI_ERROR_THREAD_NOT_ALIVE;
1400 }
1401
1402 // Check if java_thread is fully suspended
1403 if (!java_thread->is_thread_fully_suspended(true /* wait for suspend completion */, &debug_bits)) {
1404 return JVMTI_ERROR_THREAD_NOT_SUSPENDED;
1405 }
1406
1407 // Check to see if a ForceEarlyReturn was already in progress
1408 if (state->is_earlyret_pending()) {
1409 // Probably possible for JVMTI clients to trigger this, but the
1410 // JPDA backend shouldn't allow this to happen
1411 return JVMTI_ERROR_INTERNAL;
1412 }
1413 {
1414 // The same as for PopFrame. Workaround bug:
1415 // 4812902: popFrame hangs if the method is waiting at a synchronize
1416 // Catch this condition and return an error to avoid hanging.
1417 // Now JVMTI spec allows an implementation to bail out with an opaque
1418 // frame error.
1419 OSThread* osThread = java_thread->osthread();
1420 if (osThread->get_state() == MONITOR_WAIT) {
1421 return JVMTI_ERROR_OPAQUE_FRAME;
1422 }
1423 }
1424 Handle ret_ob_h;
1425 jvmtiError err = check_top_frame(current_thread, java_thread, value, tos, &ret_ob_h);
1426 if (err != JVMTI_ERROR_NONE) {
1427 return err;
1428 }
1429 assert(tos != atos || value.l == NULL || ret_ob_h() != NULL,
1430 "return object oop must not be NULL if jobject is not NULL");
1431
1432 // Update the thread state to reflect that the top frame must be
1433 // forced to return.
1434 // The current frame will be returned later when the suspended
1435 // thread is resumed and right before returning from VM to Java.
1436 // (see call_VM_base() in assembler_<cpu>.cpp).
1437
1438 state->set_earlyret_pending();
1439 state->set_earlyret_oop(ret_ob_h());
1440 state->set_earlyret_value(value, tos);
1441
1442 // Set pending step flag for this early return.
1443 // It is cleared when next step event is posted.
1444 state->set_pending_step_for_earlyret();
1445
1446 return JVMTI_ERROR_NONE;
1447 } /* end force_early_return */
1448
1449 void
1450 JvmtiMonitorClosure::do_monitor(ObjectMonitor* mon) {
1451 if ( _error != JVMTI_ERROR_NONE) {
1452 // Error occurred in previous iteration so no need to add
1453 // to the list.
1454 return;
1455 }
1456 if (mon->owner() == _java_thread ) {
1457 // Filter out on stack monitors collected during stack walk.
1458 oop obj = (oop)mon->object();
1459 bool found = false;
1460 for (int j = 0; j < _owned_monitors_list->length(); j++) {
1461 jobject jobj = ((jvmtiMonitorStackDepthInfo*)_owned_monitors_list->at(j))->monitor;
1462 oop check = JNIHandles::resolve(jobj);
1463 if (check == obj) {
1464 // On stack monitor already collected during the stack walk.
1465 found = true;
1466 break;
1467 }
1468 }
1469 if (found == false) {
1470 // This is off stack monitor (e.g. acquired via jni MonitorEnter).
1471 jvmtiError err;
1472 jvmtiMonitorStackDepthInfo *jmsdi;
1473 err = _env->allocate(sizeof(jvmtiMonitorStackDepthInfo), (unsigned char **)&jmsdi);
1474 if (err != JVMTI_ERROR_NONE) {
1475 _error = err;
1476 return;
1477 }
1478 Handle hobj(Thread::current(), obj);
1479 jmsdi->monitor = _env->jni_reference(_calling_thread, hobj);
1480 // stack depth is unknown for this monitor.
1481 jmsdi->stack_depth = -1;
1482 _owned_monitors_list->append(jmsdi);
1483 }
1484 }
1485 }
1486
1487 GrowableArray<OopHandle>* JvmtiModuleClosure::_tbl = NULL;
1488
1489 void JvmtiModuleClosure::do_module(ModuleEntry* entry) {
1490 assert_locked_or_safepoint(Module_lock);
1491 OopHandle module = entry->module_handle();
1492 guarantee(module.resolve() != NULL, "module object is NULL");
1493 _tbl->push(module);
1494 }
1495
1496 jvmtiError
1497 JvmtiModuleClosure::get_all_modules(JvmtiEnv* env, jint* module_count_ptr, jobject** modules_ptr) {
1498 ResourceMark rm;
1499 MutexLocker mcld(ClassLoaderDataGraph_lock);
1500 MutexLocker ml(Module_lock);
1501
1502 _tbl = new GrowableArray<OopHandle>(77);
1503 if (_tbl == NULL) {
1504 return JVMTI_ERROR_OUT_OF_MEMORY;
1505 }
1506
1507 // Iterate over all the modules loaded to the system.
1508 ClassLoaderDataGraph::modules_do(&do_module);
1509
1510 jint len = _tbl->length();
1511 guarantee(len > 0, "at least one module must be present");
1512
1513 jobject* array = (jobject*)env->jvmtiMalloc((jlong)(len * sizeof(jobject)));
1514 if (array == NULL) {
1515 return JVMTI_ERROR_OUT_OF_MEMORY;
1516 }
1517 for (jint idx = 0; idx < len; idx++) {
1518 array[idx] = JNIHandles::make_local(Thread::current(), _tbl->at(idx).resolve());
1519 }
1520 _tbl = NULL;
1521 *modules_ptr = array;
1522 *module_count_ptr = len;
1523 return JVMTI_ERROR_NONE;
1524 }
1525
1526 void
1527 VM_UpdateForPopTopFrame::doit() {
1528 JavaThread* jt = _state->get_thread();
1529 ThreadsListHandle tlh;
1530 if (jt != NULL && tlh.includes(jt) && !jt->is_exiting() && jt->threadObj() != NULL) {
1531 _state->update_for_pop_top_frame();
1532 } else {
1533 _result = JVMTI_ERROR_THREAD_NOT_ALIVE;
1534 }
1535 }
1536
1537 void
1538 VM_SetFramePop::doit() {
1539 JavaThread* jt = _state->get_thread();
1540 ThreadsListHandle tlh;
1541 if (jt != NULL && tlh.includes(jt) && !jt->is_exiting() && jt->threadObj() != NULL) {
1542 int frame_number = _state->count_frames() - _depth;
1543 _state->env_thread_state((JvmtiEnvBase*)_env)->set_frame_pop(frame_number);
1544 } else {
1545 _result = JVMTI_ERROR_THREAD_NOT_ALIVE;
1546 }
1547 }
1548
1549 void
1550 GetOwnedMonitorInfoClosure::do_thread(Thread *target) {
1551 _result = ((JvmtiEnvBase *)_env)->get_owned_monitors(_calling_thread, (JavaThread *)target, _owned_monitors_list);
1552 }
1553
1554 void
1555 GetCurrentContendedMonitorClosure::do_thread(Thread *target) {
1556 _result = ((JvmtiEnvBase *)_env)->get_current_contended_monitor(_calling_thread, (JavaThread *)target, _owned_monitor_ptr);
1557 }
1558
1559 void
1560 VM_GetStackTrace::doit() {
1561 _result = JVMTI_ERROR_THREAD_NOT_ALIVE;
1562 ThreadsListHandle tlh;
1563 if (_java_thread != NULL && tlh.includes(_java_thread)
1564 && !_java_thread->is_exiting() && _java_thread->threadObj() != NULL) {
1565 _result = ((JvmtiEnvBase *)_env)->get_stack_trace(_java_thread,
1566 _start_depth, _max_count,
1567 _frame_buffer, _count_ptr);
1568 }
1569 }
1570
1571 void
1572 VM_GetFrameCount::doit() {
1573 _result = JVMTI_ERROR_THREAD_NOT_ALIVE;
1574 JavaThread* jt = _state->get_thread();
1575 ThreadsListHandle tlh;
1576 if (jt != NULL && tlh.includes(jt) && !jt->is_exiting() && jt->threadObj() != NULL) {
1577 _result = ((JvmtiEnvBase*)_env)->get_frame_count(_state, _count_ptr);
1578 }
1579 }
1580
1581 void
1582 VM_GetFrameLocation::doit() {
1583 _result = JVMTI_ERROR_THREAD_NOT_ALIVE;
1584 ThreadsListHandle tlh;
1585 if (_java_thread != NULL && tlh.includes(_java_thread)
1586 && !_java_thread->is_exiting() && _java_thread->threadObj() != NULL) {
1587 _result = ((JvmtiEnvBase*)_env)->get_frame_location(_java_thread, _depth,
1588 _method_ptr, _location_ptr);
1589 }
1590 }