1 /*
2 * Copyright (c) 2003, 2021, 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/javaClasses.hpp"
28 #include "classfile/moduleEntry.hpp"
29 #include "jvmtifiles/jvmtiEnv.hpp"
30 #include "memory/iterator.hpp"
31 #include "memory/resourceArea.hpp"
32 #include "oops/klass.inline.hpp"
33 #include "oops/objArrayKlass.hpp"
34 #include "oops/objArrayOop.hpp"
35 #include "oops/oop.inline.hpp"
36 #include "oops/oopHandle.inline.hpp"
37 #include "prims/jvmtiEnvBase.hpp"
38 #include "prims/jvmtiEventController.inline.hpp"
39 #include "prims/jvmtiExtensions.hpp"
40 #include "prims/jvmtiImpl.hpp"
41 #include "prims/jvmtiManageCapabilities.hpp"
42 #include "prims/jvmtiTagMap.hpp"
43 #include "prims/jvmtiThreadState.inline.hpp"
44 #include "runtime/biasedLocking.hpp"
45 #include "runtime/deoptimization.hpp"
46 #include "runtime/frame.inline.hpp"
47 #include "runtime/handles.inline.hpp"
48 #include "runtime/interfaceSupport.inline.hpp"
49 #include "runtime/jfieldIDWorkaround.hpp"
50 #include "runtime/jniHandles.inline.hpp"
51 #include "runtime/objectMonitor.inline.hpp"
52 #include "runtime/osThread.hpp"
53 #include "runtime/signature.hpp"
54 #include "runtime/thread.inline.hpp"
55 #include "runtime/threadSMR.hpp"
56 #include "runtime/vframe.inline.hpp"
57 #include "runtime/vframe_hp.hpp"
58 #include "runtime/vmThread.hpp"
59 #include "runtime/vmOperations.hpp"
60
61
62 ///////////////////////////////////////////////////////////////
63 //
64 // JvmtiEnvBase
65 //
66
67 JvmtiEnvBase* JvmtiEnvBase::_head_environment = NULL;
68
69 bool JvmtiEnvBase::_globally_initialized = false;
70 volatile bool JvmtiEnvBase::_needs_clean_up = false;
71
72 jvmtiPhase JvmtiEnvBase::_phase = JVMTI_PHASE_PRIMORDIAL;
73
74 volatile int JvmtiEnvBase::_dying_thread_env_iteration_count = 0;
75
76 extern jvmtiInterface_1_ jvmti_Interface;
77 extern jvmtiInterface_1_ jvmtiTrace_Interface;
78
79
80 // perform initializations that must occur before any JVMTI environments
81 // are released but which should only be initialized once (no matter
82 // how many environments are created).
83 void
84 JvmtiEnvBase::globally_initialize() {
85 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
86 assert(_globally_initialized == false, "bad call");
87
88 JvmtiManageCapabilities::initialize();
89
90 // register extension functions and events
91 JvmtiExtensions::register_extensions();
92
93 #ifdef JVMTI_TRACE
94 JvmtiTrace::initialize();
95 #endif
96
97 _globally_initialized = true;
98 }
99
100
101 void
102 JvmtiEnvBase::initialize() {
103 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
104
105 // Add this environment to the end of the environment list (order is important)
106 {
107 // This block of code must not contain any safepoints, as list deallocation
108 // (which occurs at a safepoint) cannot occur simultaneously with this list
109 // addition. Note: NoSafepointVerifier cannot, currently, be used before
110 // threads exist.
111 JvmtiEnvIterator it;
112 JvmtiEnvBase *previous_env = NULL;
113 for (JvmtiEnvBase* env = it.first(); env != NULL; env = it.next(env)) {
114 previous_env = env;
115 }
116 if (previous_env == NULL) {
117 _head_environment = this;
118 } else {
119 previous_env->set_next_environment(this);
120 }
121 }
122
123 if (_globally_initialized == false) {
124 globally_initialize();
125 }
126 }
127
128 jvmtiPhase
129 JvmtiEnvBase::phase() {
130 // For the JVMTI environments possessed the can_generate_early_vmstart:
131 // replace JVMTI_PHASE_PRIMORDIAL with JVMTI_PHASE_START
132 if (_phase == JVMTI_PHASE_PRIMORDIAL &&
133 JvmtiExport::early_vmstart_recorded() &&
134 early_vmstart_env()) {
135 return JVMTI_PHASE_START;
136 }
137 return _phase; // Normal case
138 }
139
140 bool
141 JvmtiEnvBase::is_valid() {
142 jint value = 0;
143
144 // This object might not be a JvmtiEnvBase so we can't assume
145 // the _magic field is properly aligned. Get the value in a safe
146 // way and then check against JVMTI_MAGIC.
147
148 switch (sizeof(_magic)) {
149 case 2:
150 value = Bytes::get_native_u2((address)&_magic);
151 break;
152
153 case 4:
154 value = Bytes::get_native_u4((address)&_magic);
155 break;
156
157 case 8:
158 value = Bytes::get_native_u8((address)&_magic);
159 break;
160
161 default:
162 guarantee(false, "_magic field is an unexpected size");
163 }
164
165 return value == JVMTI_MAGIC;
166 }
167
168
169 bool
170 JvmtiEnvBase::use_version_1_0_semantics() {
171 int major, minor, micro;
172
173 JvmtiExport::decode_version_values(_version, &major, &minor, µ);
174 return major == 1 && minor == 0; // micro version doesn't matter here
175 }
176
177
178 bool
179 JvmtiEnvBase::use_version_1_1_semantics() {
180 int major, minor, micro;
181
182 JvmtiExport::decode_version_values(_version, &major, &minor, µ);
183 return major == 1 && minor == 1; // micro version doesn't matter here
184 }
185
186 bool
187 JvmtiEnvBase::use_version_1_2_semantics() {
188 int major, minor, micro;
189
190 JvmtiExport::decode_version_values(_version, &major, &minor, µ);
191 return major == 1 && minor == 2; // micro version doesn't matter here
192 }
193
194
195 JvmtiEnvBase::JvmtiEnvBase(jint version) : _env_event_enable() {
196 _version = version;
197 _env_local_storage = NULL;
198 _tag_map = NULL;
199 _native_method_prefix_count = 0;
200 _native_method_prefixes = NULL;
201 _next = NULL;
202 _class_file_load_hook_ever_enabled = false;
203
204 // Moot since ClassFileLoadHook not yet enabled.
205 // But "true" will give a more predictable ClassFileLoadHook behavior
206 // for environment creation during ClassFileLoadHook.
207 _is_retransformable = true;
208
209 // all callbacks initially NULL
210 memset(&_event_callbacks,0,sizeof(jvmtiEventCallbacks));
211
212 // all capabilities initially off
213 memset(&_current_capabilities, 0, sizeof(_current_capabilities));
214
215 // all prohibited capabilities initially off
216 memset(&_prohibited_capabilities, 0, sizeof(_prohibited_capabilities));
217
218 _magic = JVMTI_MAGIC;
219
220 JvmtiEventController::env_initialize((JvmtiEnv*)this);
221
222 #ifdef JVMTI_TRACE
223 _jvmti_external.functions = TraceJVMTI != NULL ? &jvmtiTrace_Interface : &jvmti_Interface;
224 #else
225 _jvmti_external.functions = &jvmti_Interface;
226 #endif
227 }
228
229
230 void
231 JvmtiEnvBase::dispose() {
232
233 #ifdef JVMTI_TRACE
234 JvmtiTrace::shutdown();
235 #endif
236
237 // Dispose of event info and let the event controller call us back
238 // in a locked state (env_dispose, below)
239 JvmtiEventController::env_dispose(this);
240 }
241
242 void
243 JvmtiEnvBase::env_dispose() {
244 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
245
246 // We have been entered with all events disabled on this environment.
247 // A race to re-enable events (by setting callbacks) is prevented by
248 // checking for a valid environment when setting callbacks (while
249 // holding the JvmtiThreadState_lock).
250
251 // Mark as invalid.
252 _magic = DISPOSED_MAGIC;
253
254 // Relinquish all capabilities.
255 jvmtiCapabilities *caps = get_capabilities();
256 JvmtiManageCapabilities::relinquish_capabilities(caps, caps, caps);
257
258 // Same situation as with events (see above)
259 set_native_method_prefixes(0, NULL);
260
261 JvmtiTagMap* tag_map_to_clear = tag_map_acquire();
262 // A tag map can be big, clear it now to save memory until
263 // the destructor runs.
264 if (tag_map_to_clear != NULL) {
265 tag_map_to_clear->clear();
266 }
267
268 _needs_clean_up = true;
269 }
270
271
272 JvmtiEnvBase::~JvmtiEnvBase() {
273 assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
274
275 // There is a small window of time during which the tag map of a
276 // disposed environment could have been reallocated.
277 // Make sure it is gone.
278 JvmtiTagMap* tag_map_to_deallocate = _tag_map;
279 set_tag_map(NULL);
280 // A tag map can be big, deallocate it now
281 if (tag_map_to_deallocate != NULL) {
282 delete tag_map_to_deallocate;
283 }
284
285 _magic = BAD_MAGIC;
286 }
287
288
289 void
290 JvmtiEnvBase::periodic_clean_up() {
291 assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
292
293 // JvmtiEnvBase reference is saved in JvmtiEnvThreadState. So
294 // clean up JvmtiThreadState before deleting JvmtiEnv pointer.
295 JvmtiThreadState::periodic_clean_up();
296
297 // Unlink all invalid environments from the list of environments
298 // and deallocate them
299 JvmtiEnvIterator it;
300 JvmtiEnvBase* previous_env = NULL;
301 JvmtiEnvBase* env = it.first();
302 while (env != NULL) {
303 if (env->is_valid()) {
304 previous_env = env;
305 env = it.next(env);
306 } else {
307 // This one isn't valid, remove it from the list and deallocate it
308 JvmtiEnvBase* defunct_env = env;
309 env = it.next(env);
310 if (previous_env == NULL) {
311 _head_environment = env;
312 } else {
313 previous_env->set_next_environment(env);
314 }
315 delete defunct_env;
316 }
317 }
318
319 }
320
321
322 void
323 JvmtiEnvBase::check_for_periodic_clean_up() {
324 assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
325
326 class ThreadInsideIterationClosure: public ThreadClosure {
327 private:
328 bool _inside;
329 public:
330 ThreadInsideIterationClosure() : _inside(false) {};
331
332 void do_thread(Thread* thread) {
333 _inside |= thread->is_inside_jvmti_env_iteration();
334 }
335
336 bool is_inside_jvmti_env_iteration() {
337 return _inside;
338 }
339 };
340
341 if (_needs_clean_up) {
342 // Check if we are currently iterating environment,
343 // deallocation should not occur if we are
344 ThreadInsideIterationClosure tiic;
345 Threads::threads_do(&tiic);
346 if (!tiic.is_inside_jvmti_env_iteration() &&
347 !is_inside_dying_thread_env_iteration()) {
348 _needs_clean_up = false;
349 JvmtiEnvBase::periodic_clean_up();
350 }
351 }
352 }
353
354
355 void
356 JvmtiEnvBase::record_first_time_class_file_load_hook_enabled() {
357 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(),
358 "sanity check");
359
360 if (!_class_file_load_hook_ever_enabled) {
361 _class_file_load_hook_ever_enabled = true;
362
363 if (get_capabilities()->can_retransform_classes) {
364 _is_retransformable = true;
365 } else {
366 _is_retransformable = false;
367
368 // cannot add retransform capability after ClassFileLoadHook has been enabled
369 get_prohibited_capabilities()->can_retransform_classes = 1;
370 }
371 }
372 }
373
374
375 void
376 JvmtiEnvBase::record_class_file_load_hook_enabled() {
377 if (!_class_file_load_hook_ever_enabled) {
378 if (Threads::number_of_threads() == 0) {
379 record_first_time_class_file_load_hook_enabled();
380 } else {
381 MutexLocker mu(JvmtiThreadState_lock);
382 record_first_time_class_file_load_hook_enabled();
383 }
384 }
385 }
386
387
388 jvmtiError
389 JvmtiEnvBase::set_native_method_prefixes(jint prefix_count, char** prefixes) {
390 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(),
391 "sanity check");
392
393 int old_prefix_count = get_native_method_prefix_count();
394 char **old_prefixes = get_native_method_prefixes();
395
396 // allocate and install the new prefixex
397 if (prefix_count == 0 || !is_valid()) {
398 _native_method_prefix_count = 0;
399 _native_method_prefixes = NULL;
400 } else {
401 // there are prefixes, allocate an array to hold them, and fill it
402 char** new_prefixes = (char**)os::malloc((prefix_count) * sizeof(char*), mtInternal);
403 if (new_prefixes == NULL) {
404 return JVMTI_ERROR_OUT_OF_MEMORY;
405 }
406 for (int i = 0; i < prefix_count; i++) {
407 char* prefix = prefixes[i];
408 if (prefix == NULL) {
409 for (int j = 0; j < (i-1); j++) {
410 os::free(new_prefixes[j]);
411 }
412 os::free(new_prefixes);
413 return JVMTI_ERROR_NULL_POINTER;
414 }
415 prefix = os::strdup(prefixes[i]);
416 if (prefix == NULL) {
417 for (int j = 0; j < (i-1); j++) {
418 os::free(new_prefixes[j]);
419 }
420 os::free(new_prefixes);
421 return JVMTI_ERROR_OUT_OF_MEMORY;
422 }
423 new_prefixes[i] = prefix;
424 }
425 _native_method_prefix_count = prefix_count;
426 _native_method_prefixes = new_prefixes;
427 }
428
429 // now that we know the new prefixes have been successfully installed we can
430 // safely remove the old ones
431 if (old_prefix_count != 0) {
432 for (int i = 0; i < old_prefix_count; i++) {
433 os::free(old_prefixes[i]);
434 }
435 os::free(old_prefixes);
436 }
437
438 return JVMTI_ERROR_NONE;
439 }
440
441
442 // Collect all the prefixes which have been set in any JVM TI environments
443 // by the SetNativeMethodPrefix(es) functions. Be sure to maintain the
444 // order of environments and the order of prefixes within each environment.
445 // Return in a resource allocated array.
446 char**
447 JvmtiEnvBase::get_all_native_method_prefixes(int* count_ptr) {
448 assert(Threads::number_of_threads() == 0 ||
449 SafepointSynchronize::is_at_safepoint() ||
450 JvmtiThreadState_lock->is_locked(),
451 "sanity check");
452
453 int total_count = 0;
454 GrowableArray<char*>* prefix_array =new GrowableArray<char*>(5);
455
456 JvmtiEnvIterator it;
457 for (JvmtiEnvBase* env = it.first(); env != NULL; env = it.next(env)) {
458 int prefix_count = env->get_native_method_prefix_count();
459 char** prefixes = env->get_native_method_prefixes();
460 for (int j = 0; j < prefix_count; j++) {
461 // retrieve a prefix and so that it is safe against asynchronous changes
462 // copy it into the resource area
463 char* prefix = prefixes[j];
464 char* prefix_copy = NEW_RESOURCE_ARRAY(char, strlen(prefix)+1);
465 strcpy(prefix_copy, prefix);
466 prefix_array->at_put_grow(total_count++, prefix_copy);
467 }
468 }
469
470 char** all_prefixes = NEW_RESOURCE_ARRAY(char*, total_count);
471 char** p = all_prefixes;
472 for (int i = 0; i < total_count; ++i) {
473 *p++ = prefix_array->at(i);
474 }
475 *count_ptr = total_count;
476 return all_prefixes;
477 }
478
479 void
480 JvmtiEnvBase::set_event_callbacks(const jvmtiEventCallbacks* callbacks,
481 jint size_of_callbacks) {
482 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
483
484 size_t byte_cnt = sizeof(jvmtiEventCallbacks);
485
486 // clear in either case to be sure we got any gap between sizes
487 memset(&_event_callbacks, 0, byte_cnt);
488
489 // Now that JvmtiThreadState_lock is held, prevent a possible race condition where events
490 // are re-enabled by a call to set event callbacks where the DisposeEnvironment
491 // occurs after the boiler-plate environment check and before the lock is acquired.
492 if (callbacks != NULL && is_valid()) {
493 if (size_of_callbacks < (jint)byte_cnt) {
494 byte_cnt = size_of_callbacks;
495 }
496 memcpy(&_event_callbacks, callbacks, byte_cnt);
497 }
498 }
499
500
501 // In the fullness of time, all users of the method should instead
502 // directly use allocate, besides being cleaner and faster, this will
503 // mean much better out of memory handling
504 unsigned char *
505 JvmtiEnvBase::jvmtiMalloc(jlong size) {
506 unsigned char* mem = NULL;
507 jvmtiError result = allocate(size, &mem);
508 assert(result == JVMTI_ERROR_NONE, "Allocate failed");
509 return mem;
510 }
511
512
513 // Handle management
514
515 jobject JvmtiEnvBase::jni_reference(Handle hndl) {
516 return JNIHandles::make_local(hndl());
517 }
518
519 jobject JvmtiEnvBase::jni_reference(JavaThread *thread, Handle hndl) {
520 return JNIHandles::make_local(thread, hndl());
521 }
522
523 void JvmtiEnvBase::destroy_jni_reference(jobject jobj) {
524 JNIHandles::destroy_local(jobj);
525 }
526
527 void JvmtiEnvBase::destroy_jni_reference(JavaThread *thread, jobject jobj) {
528 JNIHandles::destroy_local(jobj); // thread is unused.
529 }
530
531 //
532 // Threads
533 //
534
535 jobject *
536 JvmtiEnvBase::new_jobjectArray(int length, Handle *handles) {
537 if (length == 0) {
538 return NULL;
539 }
540
541 jobject *objArray = (jobject *) jvmtiMalloc(sizeof(jobject) * length);
542 NULL_CHECK(objArray, NULL);
543
544 for (int i=0; i<length; i++) {
545 objArray[i] = jni_reference(handles[i]);
546 }
547 return objArray;
548 }
549
550 jthread *
551 JvmtiEnvBase::new_jthreadArray(int length, Handle *handles) {
552 return (jthread *) new_jobjectArray(length,handles);
553 }
554
555 jthreadGroup *
556 JvmtiEnvBase::new_jthreadGroupArray(int length, Handle *handles) {
557 return (jthreadGroup *) new_jobjectArray(length,handles);
558 }
559
560 // return the vframe on the specified thread and depth, NULL if no such frame
561 // The thread and the oops in the returned vframe might not have been process.
562 vframe*
563 JvmtiEnvBase::vframeForNoProcess(JavaThread* java_thread, jint depth) {
564 if (!java_thread->has_last_Java_frame()) {
565 return NULL;
566 }
567 RegisterMap reg_map(java_thread, true /* update_map */, false /* process_frames */);
568 vframe *vf = java_thread->last_java_vframe(®_map);
569 int d = 0;
570 while ((vf != NULL) && (d < depth)) {
571 vf = vf->java_sender();
572 d++;
573 }
574 return vf;
575 }
576
577
578 //
579 // utilities: JNI objects
580 //
581
582
583 jclass
584 JvmtiEnvBase::get_jni_class_non_null(Klass* k) {
585 assert(k != NULL, "k != NULL");
586 Thread *thread = Thread::current();
587 return (jclass)jni_reference(Handle(thread, k->java_mirror()));
588 }
589
590 //
591 // Field Information
592 //
593
594 bool
595 JvmtiEnvBase::get_field_descriptor(Klass* k, jfieldID field, fieldDescriptor* fd) {
596 if (!jfieldIDWorkaround::is_valid_jfieldID(k, field)) {
597 return false;
598 }
599 bool found = false;
600 if (jfieldIDWorkaround::is_static_jfieldID(field)) {
601 JNIid* id = jfieldIDWorkaround::from_static_jfieldID(field);
602 found = id->find_local_field(fd);
603 } else {
604 // Non-static field. The fieldID is really the offset of the field within the object.
605 int offset = jfieldIDWorkaround::from_instance_jfieldID(k, field);
606 found = InstanceKlass::cast(k)->find_field_from_offset(offset, false, fd);
607 }
608 return found;
609 }
610
611 //
612 // Object Monitor Information
613 //
614
615 //
616 // Count the number of objects for a lightweight monitor. The hobj
617 // parameter is object that owns the monitor so this routine will
618 // count the number of times the same object was locked by frames
619 // in java_thread.
620 //
621 jint
622 JvmtiEnvBase::count_locked_objects(JavaThread *java_thread, Handle hobj) {
623 jint ret = 0;
624 if (!java_thread->has_last_Java_frame()) {
625 return ret; // no Java frames so no monitors
626 }
627
628 Thread* current_thread = Thread::current();
629 ResourceMark rm(current_thread);
630 HandleMark hm(current_thread);
631 RegisterMap reg_map(java_thread);
632
633 for(javaVFrame *jvf=java_thread->last_java_vframe(®_map); jvf != NULL;
634 jvf = jvf->java_sender()) {
635 GrowableArray<MonitorInfo*>* mons = jvf->monitors();
636 if (!mons->is_empty()) {
637 for (int i = 0; i < mons->length(); i++) {
638 MonitorInfo *mi = mons->at(i);
639 if (mi->owner_is_scalar_replaced()) continue;
640
641 // see if owner of the monitor is our object
642 if (mi->owner() != NULL && mi->owner() == hobj()) {
643 ret++;
644 }
645 }
646 }
647 }
648 return ret;
649 }
650
651
652
653 jvmtiError
654 JvmtiEnvBase::get_current_contended_monitor(JavaThread *calling_thread, JavaThread *java_thread, jobject *monitor_ptr) {
655 Thread *current_thread = Thread::current();
656 assert(java_thread->is_handshake_safe_for(current_thread),
657 "call by myself or at handshake");
658 oop obj = NULL;
659 // The ObjectMonitor* can't be async deflated since we are either
660 // at a safepoint or the calling thread is operating on itself so
661 // it cannot leave the underlying wait()/enter() call.
662 ObjectMonitor *mon = java_thread->current_waiting_monitor();
663 if (mon == NULL) {
664 // thread is not doing an Object.wait() call
665 mon = java_thread->current_pending_monitor();
666 if (mon != NULL) {
667 // The thread is trying to enter() an ObjectMonitor.
668 obj = mon->object();
669 assert(obj != NULL, "ObjectMonitor should have a valid object!");
670 }
671 // implied else: no contended ObjectMonitor
672 } else {
673 // thread is doing an Object.wait() call
674 obj = mon->object();
675 assert(obj != NULL, "Object.wait() should have an object");
676 }
677
678 if (obj == NULL) {
679 *monitor_ptr = NULL;
680 } else {
681 HandleMark hm(current_thread);
682 Handle hobj(current_thread, obj);
683 *monitor_ptr = jni_reference(calling_thread, hobj);
684 }
685 return JVMTI_ERROR_NONE;
686 }
687
688
689 jvmtiError
690 JvmtiEnvBase::get_owned_monitors(JavaThread *calling_thread, JavaThread* java_thread,
691 GrowableArray<jvmtiMonitorStackDepthInfo*> *owned_monitors_list) {
692 // Note:
693 // calling_thread is the thread that requested the list of monitors for java_thread.
694 // java_thread is the thread owning the monitors.
695 // current_thread is the thread executing this code, can be a non-JavaThread (e.g. VM Thread).
696 // And they all may be different threads.
697 jvmtiError err = JVMTI_ERROR_NONE;
698 Thread *current_thread = Thread::current();
699 assert(java_thread->is_handshake_safe_for(current_thread),
700 "call by myself or at handshake");
701
702 if (java_thread->has_last_Java_frame()) {
703 ResourceMark rm(current_thread);
704 HandleMark hm(current_thread);
705 RegisterMap reg_map(java_thread);
706
707 int depth = 0;
708 for (javaVFrame *jvf = java_thread->last_java_vframe(®_map); jvf != NULL;
709 jvf = jvf->java_sender()) {
710 if (MaxJavaStackTraceDepth == 0 || depth++ < MaxJavaStackTraceDepth) { // check for stack too deep
711 // add locked objects for this frame into list
712 err = get_locked_objects_in_frame(calling_thread, java_thread, jvf, owned_monitors_list, depth-1);
713 if (err != JVMTI_ERROR_NONE) {
714 return err;
715 }
716 }
717 }
718 }
719
720 // Get off stack monitors. (e.g. acquired via jni MonitorEnter).
721 JvmtiMonitorClosure jmc(calling_thread, owned_monitors_list, this);
722 ObjectSynchronizer::monitors_iterate(&jmc, java_thread);
723 err = jmc.error();
724
725 return err;
726 }
727
728 // Save JNI local handles for any objects that this frame owns.
729 jvmtiError
730 JvmtiEnvBase::get_locked_objects_in_frame(JavaThread* calling_thread, JavaThread* java_thread,
731 javaVFrame *jvf, GrowableArray<jvmtiMonitorStackDepthInfo*>* owned_monitors_list, jint stack_depth) {
732 jvmtiError err = JVMTI_ERROR_NONE;
733 Thread* current_thread = Thread::current();
734 ResourceMark rm(current_thread);
735 HandleMark hm(current_thread);
736
737 GrowableArray<MonitorInfo*>* mons = jvf->monitors();
738 if (mons->is_empty()) {
739 return err; // this javaVFrame holds no monitors
740 }
741
742 oop wait_obj = NULL;
743 {
744 // The ObjectMonitor* can't be async deflated since we are either
745 // at a safepoint or the calling thread is operating on itself so
746 // it cannot leave the underlying wait() call.
747 // Save object of current wait() call (if any) for later comparison.
748 ObjectMonitor *mon = java_thread->current_waiting_monitor();
749 if (mon != NULL) {
750 wait_obj = mon->object();
751 }
752 }
753 oop pending_obj = NULL;
754 {
755 // The ObjectMonitor* can't be async deflated since we are either
756 // at a safepoint or the calling thread is operating on itself so
757 // it cannot leave the underlying enter() call.
758 // Save object of current enter() call (if any) for later comparison.
759 ObjectMonitor *mon = java_thread->current_pending_monitor();
760 if (mon != NULL) {
761 pending_obj = mon->object();
762 }
763 }
764
765 for (int i = 0; i < mons->length(); i++) {
766 MonitorInfo *mi = mons->at(i);
767
768 if (mi->owner_is_scalar_replaced()) continue;
769
770 oop obj = mi->owner();
771 if (obj == NULL) {
772 // this monitor doesn't have an owning object so skip it
773 continue;
774 }
775
776 if (wait_obj == obj) {
777 // the thread is waiting on this monitor so it isn't really owned
778 continue;
779 }
780
781 if (pending_obj == obj) {
782 // the thread is pending on this monitor so it isn't really owned
783 continue;
784 }
785
786 if (owned_monitors_list->length() > 0) {
787 // Our list has at least one object on it so we have to check
788 // for recursive object locking
789 bool found = false;
790 for (int j = 0; j < owned_monitors_list->length(); j++) {
791 jobject jobj = ((jvmtiMonitorStackDepthInfo*)owned_monitors_list->at(j))->monitor;
792 oop check = JNIHandles::resolve(jobj);
793 if (check == obj) {
794 found = true; // we found the object
795 break;
796 }
797 }
798
799 if (found) {
800 // already have this object so don't include it
801 continue;
802 }
803 }
804
805 // add the owning object to our list
806 jvmtiMonitorStackDepthInfo *jmsdi;
807 err = allocate(sizeof(jvmtiMonitorStackDepthInfo), (unsigned char **)&jmsdi);
808 if (err != JVMTI_ERROR_NONE) {
809 return err;
810 }
811 Handle hobj(Thread::current(), obj);
812 jmsdi->monitor = jni_reference(calling_thread, hobj);
813 jmsdi->stack_depth = stack_depth;
814 owned_monitors_list->append(jmsdi);
815 }
816
817 return err;
818 }
819
820 jvmtiError
821 JvmtiEnvBase::get_stack_trace(JavaThread *java_thread,
822 jint start_depth, jint max_count,
823 jvmtiFrameInfo* frame_buffer, jint* count_ptr) {
824 #ifdef ASSERT
825 uint32_t debug_bits = 0;
826 #endif
827 Thread *current_thread = Thread::current();
828 assert(SafepointSynchronize::is_at_safepoint() ||
829 java_thread->is_handshake_safe_for(current_thread),
830 "call by myself / at safepoint / at handshake");
831 int count = 0;
832 if (java_thread->has_last_Java_frame()) {
833 RegisterMap reg_map(java_thread, false /* update_map */, false /* process_frames */);
834 ResourceMark rm(current_thread);
835 javaVFrame *jvf = java_thread->last_java_vframe(®_map);
836 HandleMark hm(current_thread);
837 if (start_depth != 0) {
838 if (start_depth > 0) {
839 for (int j = 0; j < start_depth && jvf != NULL; j++) {
840 jvf = jvf->java_sender();
841 }
842 if (jvf == NULL) {
843 // start_depth is deeper than the stack depth
844 return JVMTI_ERROR_ILLEGAL_ARGUMENT;
845 }
846 } else { // start_depth < 0
847 // we are referencing the starting depth based on the oldest
848 // part of the stack.
849 // optimize to limit the number of times that java_sender() is called
850 javaVFrame *jvf_cursor = jvf;
851 javaVFrame *jvf_prev = NULL;
852 javaVFrame *jvf_prev_prev = NULL;
853 int j = 0;
854 while (jvf_cursor != NULL) {
855 jvf_prev_prev = jvf_prev;
856 jvf_prev = jvf_cursor;
857 for (j = 0; j > start_depth && jvf_cursor != NULL; j--) {
858 jvf_cursor = jvf_cursor->java_sender();
859 }
860 }
861 if (j == start_depth) {
862 // previous pointer is exactly where we want to start
863 jvf = jvf_prev;
864 } else {
865 // we need to back up further to get to the right place
866 if (jvf_prev_prev == NULL) {
867 // the -start_depth is greater than the stack depth
868 return JVMTI_ERROR_ILLEGAL_ARGUMENT;
869 }
870 // j now is the number of frames on the stack starting with
871 // jvf_prev, we start from jvf_prev_prev and move older on
872 // the stack that many, the result is -start_depth frames
873 // remaining.
874 jvf = jvf_prev_prev;
875 for (; j < 0; j++) {
876 jvf = jvf->java_sender();
877 }
878 }
879 }
880 }
881 for (; count < max_count && jvf != NULL; count++) {
882 frame_buffer[count].method = jvf->method()->jmethod_id();
883 frame_buffer[count].location = (jvf->method()->is_native() ? -1 : jvf->bci());
884 jvf = jvf->java_sender();
885 }
886 } else {
887 if (start_depth != 0) {
888 // no frames and there is a starting depth
889 return JVMTI_ERROR_ILLEGAL_ARGUMENT;
890 }
891 }
892 *count_ptr = count;
893 return JVMTI_ERROR_NONE;
894 }
895
896 jvmtiError
897 JvmtiEnvBase::get_frame_count(JvmtiThreadState *state, jint *count_ptr) {
898 assert((state != NULL),
899 "JavaThread should create JvmtiThreadState before calling this method");
900 *count_ptr = state->count_frames();
901 return JVMTI_ERROR_NONE;
902 }
903
904 jvmtiError
905 JvmtiEnvBase::get_frame_location(JavaThread *java_thread, jint depth,
906 jmethodID* method_ptr, jlocation* location_ptr) {
907 #ifdef ASSERT
908 uint32_t debug_bits = 0;
909 #endif
910 Thread* current_thread = Thread::current();
911 assert(java_thread->is_handshake_safe_for(current_thread),
912 "call by myself or at handshake");
913 ResourceMark rm(current_thread);
914
915 vframe *vf = vframeForNoProcess(java_thread, depth);
916 if (vf == NULL) {
917 return JVMTI_ERROR_NO_MORE_FRAMES;
918 }
919
920 // vframeFor should return a java frame. If it doesn't
921 // it means we've got an internal error and we return the
922 // error in product mode. In debug mode we will instead
923 // attempt to cast the vframe to a javaVFrame and will
924 // cause an assertion/crash to allow further diagnosis.
925 #ifdef PRODUCT
926 if (!vf->is_java_frame()) {
927 return JVMTI_ERROR_INTERNAL;
928 }
929 #endif
930
931 HandleMark hm(current_thread);
932 javaVFrame *jvf = javaVFrame::cast(vf);
933 Method* method = jvf->method();
934 if (method->is_native()) {
935 *location_ptr = -1;
936 } else {
937 *location_ptr = jvf->bci();
938 }
939 *method_ptr = method->jmethod_id();
940
941 return JVMTI_ERROR_NONE;
942 }
943
944
945 jvmtiError
946 JvmtiEnvBase::get_object_monitor_usage(JavaThread* calling_thread, jobject object, jvmtiMonitorUsage* info_ptr) {
947 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
948 Thread* current_thread = VMThread::vm_thread();
949 assert(current_thread == Thread::current(), "must be");
950
951 HandleMark hm(current_thread);
952 Handle hobj;
953
954 // Check arguments
955 {
956 oop mirror = JNIHandles::resolve_external_guard(object);
957 NULL_CHECK(mirror, JVMTI_ERROR_INVALID_OBJECT);
958 NULL_CHECK(info_ptr, JVMTI_ERROR_NULL_POINTER);
959
960 hobj = Handle(current_thread, mirror);
961 }
962
963 ThreadsListHandle tlh(current_thread);
964 JavaThread *owning_thread = NULL;
965 ObjectMonitor *mon = NULL;
966 jvmtiMonitorUsage ret = {
967 NULL, 0, 0, NULL, 0, NULL
968 };
969
970 uint32_t debug_bits = 0;
971 // first derive the object's owner and entry_count (if any)
972 {
973 owning_thread = ObjectSynchronizer::get_lock_owner(tlh.list(), hobj);
974
975 if (owning_thread != NULL) { // monitor is owned
976 // The recursions field of a monitor does not reflect recursions
977 // as lightweight locks before inflating the monitor are not included.
978 // We have to count the number of recursive monitor entries the hard way.
979 // We pass a handle to survive any GCs along the way.
980 ret.entry_count = count_locked_objects(owning_thread, hobj);
981 }
982 // implied else: entry_count == 0
983 }
984
985 jint nWant = 0, nWait = 0;
986 if (mon != NULL) {
987 // this object has a heavyweight monitor
988 nWant = mon->contentions(); // # of threads contending for monitor
989 nWait = mon->waiters(); // # of threads in Object.wait()
990 ret.waiter_count = nWant + nWait;
991 ret.notify_waiter_count = nWait;
992 } else {
993 // this object has a lightweight monitor
994 ret.waiter_count = 0;
995 ret.notify_waiter_count = 0;
996 }
997
998 // Allocate memory for heavyweight and lightweight monitor.
999 jvmtiError err;
1000 err = allocate(ret.waiter_count * sizeof(jthread *), (unsigned char**)&ret.waiters);
1001 if (err != JVMTI_ERROR_NONE) {
1002 return err;
1003 }
1004 err = allocate(ret.notify_waiter_count * sizeof(jthread *),
1005 (unsigned char**)&ret.notify_waiters);
1006 if (err != JVMTI_ERROR_NONE) {
1007 deallocate((unsigned char*)ret.waiters);
1008 return err;
1009 }
1010
1011 // now derive the rest of the fields
1012 if (mon != NULL) {
1013 // this object has a heavyweight monitor
1014
1015 // Number of waiters may actually be less than the waiter count.
1016 // So NULL out memory so that unused memory will be NULL.
1017 memset(ret.waiters, 0, ret.waiter_count * sizeof(jthread *));
1018 memset(ret.notify_waiters, 0, ret.notify_waiter_count * sizeof(jthread *));
1019
1020 if (ret.waiter_count > 0) {
1021 // we have contending and/or waiting threads
1022 if (nWant > 0) {
1023 // we have contending threads
1024 ResourceMark rm(current_thread);
1025 // get_pending_threads returns only java thread so we do not need to
1026 // check for non java threads.
1027 GrowableArray<JavaThread*>* wantList = Threads::get_pending_threads(tlh.list(), nWant, (address)mon);
1028 if (wantList->length() < nWant) {
1029 // robustness: the pending list has gotten smaller
1030 nWant = wantList->length();
1031 }
1032 for (int i = 0; i < nWant; i++) {
1033 JavaThread *pending_thread = wantList->at(i);
1034 Handle th(current_thread, pending_thread->threadObj());
1035 ret.waiters[i] = (jthread)jni_reference(calling_thread, th);
1036 }
1037 }
1038 if (nWait > 0) {
1039 // we have threads in Object.wait()
1040 int offset = nWant; // add after any contending threads
1041 ObjectWaiter *waiter = mon->first_waiter();
1042 for (int i = 0, j = 0; i < nWait; i++) {
1043 if (waiter == NULL) {
1044 // robustness: the waiting list has gotten smaller
1045 nWait = j;
1046 break;
1047 }
1048 JavaThread *w = mon->thread_of_waiter(waiter);
1049 if (w != NULL) {
1050 // If the thread was found on the ObjectWaiter list, then
1051 // it has not been notified. This thread can't change the
1052 // state of the monitor so it doesn't need to be suspended.
1053 Handle th(current_thread, w->threadObj());
1054 ret.waiters[offset + j] = (jthread)jni_reference(calling_thread, th);
1055 ret.notify_waiters[j++] = (jthread)jni_reference(calling_thread, th);
1056 }
1057 waiter = mon->next_waiter(waiter);
1058 }
1059 }
1060 } // ThreadsListHandle is destroyed here.
1061
1062 // Adjust count. nWant and nWait count values may be less than original.
1063 ret.waiter_count = nWant + nWait;
1064 ret.notify_waiter_count = nWait;
1065 } else {
1066 // this object has a lightweight monitor and we have nothing more
1067 // to do here because the defaults are just fine.
1068 }
1069
1070 // we don't update return parameter unless everything worked
1071 *info_ptr = ret;
1072
1073 return JVMTI_ERROR_NONE;
1074 }
1075
1076 ResourceTracker::ResourceTracker(JvmtiEnv* env) {
1077 _env = env;
1078 _allocations = new (ResourceObj::C_HEAP, mtServiceability) GrowableArray<unsigned char*>(20, mtServiceability);
1079 _failed = false;
1080 }
1081 ResourceTracker::~ResourceTracker() {
1082 if (_failed) {
1083 for (int i=0; i<_allocations->length(); i++) {
1084 _env->deallocate(_allocations->at(i));
1085 }
1086 }
1087 delete _allocations;
1088 }
1089
1090 jvmtiError ResourceTracker::allocate(jlong size, unsigned char** mem_ptr) {
1091 unsigned char *ptr;
1092 jvmtiError err = _env->allocate(size, &ptr);
1093 if (err == JVMTI_ERROR_NONE) {
1094 _allocations->append(ptr);
1095 *mem_ptr = ptr;
1096 } else {
1097 *mem_ptr = NULL;
1098 _failed = true;
1099 }
1100 return err;
1101 }
1102
1103 unsigned char* ResourceTracker::allocate(jlong size) {
1104 unsigned char* ptr;
1105 allocate(size, &ptr);
1106 return ptr;
1107 }
1108
1109 char* ResourceTracker::strdup(const char* str) {
1110 char *dup_str = (char*)allocate(strlen(str)+1);
1111 if (dup_str != NULL) {
1112 strcpy(dup_str, str);
1113 }
1114 return dup_str;
1115 }
1116
1117 struct StackInfoNode {
1118 struct StackInfoNode *next;
1119 jvmtiStackInfo info;
1120 };
1121
1122 // Create a jvmtiStackInfo inside a linked list node and create a
1123 // buffer for the frame information, both allocated as resource objects.
1124 // Fill in both the jvmtiStackInfo and the jvmtiFrameInfo.
1125 // Note that either or both of thr and thread_oop
1126 // may be null if the thread is new or has exited.
1127 void
1128 MultipleStackTracesCollector::fill_frames(jthread jt, JavaThread *thr, oop thread_oop) {
1129 #ifdef ASSERT
1130 Thread *current_thread = Thread::current();
1131 assert(SafepointSynchronize::is_at_safepoint() ||
1132 thr->is_handshake_safe_for(current_thread),
1133 "call by myself / at safepoint / at handshake");
1134 #endif
1135
1136 jint state = 0;
1137 struct StackInfoNode *node = NEW_RESOURCE_OBJ(struct StackInfoNode);
1138 jvmtiStackInfo *infop = &(node->info);
1139 node->next = head();
1140 set_head(node);
1141 infop->frame_count = 0;
1142 infop->thread = jt;
1143
1144 if (thread_oop != NULL) {
1145 // get most state bits
1146 state = (jint)java_lang_Thread::get_thread_status(thread_oop);
1147 }
1148
1149 if (thr != NULL) { // add more state bits if there is a JavaThead to query
1150 if (thr->is_suspended()) {
1151 state |= JVMTI_THREAD_STATE_SUSPENDED;
1152 }
1153 JavaThreadState jts = thr->thread_state();
1154 if (jts == _thread_in_native) {
1155 state |= JVMTI_THREAD_STATE_IN_NATIVE;
1156 }
1157 if (thr->is_interrupted(false)) {
1158 state |= JVMTI_THREAD_STATE_INTERRUPTED;
1159 }
1160 }
1161 infop->state = state;
1162
1163 if (thr != NULL && (state & JVMTI_THREAD_STATE_ALIVE) != 0) {
1164 infop->frame_buffer = NEW_RESOURCE_ARRAY(jvmtiFrameInfo, max_frame_count());
1165 env()->get_stack_trace(thr, 0, max_frame_count(),
1166 infop->frame_buffer, &(infop->frame_count));
1167 } else {
1168 infop->frame_buffer = NULL;
1169 infop->frame_count = 0;
1170 }
1171 _frame_count_total += infop->frame_count;
1172 }
1173
1174 // Based on the stack information in the linked list, allocate memory
1175 // block to return and fill it from the info in the linked list.
1176 void
1177 MultipleStackTracesCollector::allocate_and_fill_stacks(jint thread_count) {
1178 // do I need to worry about alignment issues?
1179 jlong alloc_size = thread_count * sizeof(jvmtiStackInfo)
1180 + _frame_count_total * sizeof(jvmtiFrameInfo);
1181 env()->allocate(alloc_size, (unsigned char **)&_stack_info);
1182
1183 // pointers to move through the newly allocated space as it is filled in
1184 jvmtiStackInfo *si = _stack_info + thread_count; // bottom of stack info
1185 jvmtiFrameInfo *fi = (jvmtiFrameInfo *)si; // is the top of frame info
1186
1187 // copy information in resource area into allocated buffer
1188 // insert stack info backwards since linked list is backwards
1189 // insert frame info forwards
1190 // walk the StackInfoNodes
1191 for (struct StackInfoNode *sin = head(); sin != NULL; sin = sin->next) {
1192 jint frame_count = sin->info.frame_count;
1193 size_t frames_size = frame_count * sizeof(jvmtiFrameInfo);
1194 --si;
1195 memcpy(si, &(sin->info), sizeof(jvmtiStackInfo));
1196 if (frames_size == 0) {
1197 si->frame_buffer = NULL;
1198 } else {
1199 memcpy(fi, sin->info.frame_buffer, frames_size);
1200 si->frame_buffer = fi; // point to the new allocated copy of the frames
1201 fi += frame_count;
1202 }
1203 }
1204 assert(si == _stack_info, "the last copied stack info must be the first record");
1205 assert((unsigned char *)fi == ((unsigned char *)_stack_info) + alloc_size,
1206 "the last copied frame info must be the last record");
1207 }
1208
1209
1210 void
1211 VM_GetThreadListStackTraces::doit() {
1212 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
1213
1214 ResourceMark rm;
1215 ThreadsListHandle tlh;
1216 for (int i = 0; i < _thread_count; ++i) {
1217 jthread jt = _thread_list[i];
1218 JavaThread* java_thread = NULL;
1219 oop thread_oop = NULL;
1220 jvmtiError err = JvmtiExport::cv_external_thread_to_JavaThread(tlh.list(), jt, &java_thread, &thread_oop);
1221 if (err != JVMTI_ERROR_NONE) {
1222 // We got an error code so we don't have a JavaThread *, but
1223 // only return an error from here if we didn't get a valid
1224 // thread_oop.
1225 if (thread_oop == NULL) {
1226 _collector.set_result(err);
1227 return;
1228 }
1229 // We have a valid thread_oop.
1230 }
1231 _collector.fill_frames(jt, java_thread, thread_oop);
1232 }
1233 _collector.allocate_and_fill_stacks(_thread_count);
1234 }
1235
1236 void
1237 GetSingleStackTraceClosure::do_thread(Thread *target) {
1238 JavaThread *jt = target->as_Java_thread();
1239 oop thread_oop = jt->threadObj();
1240
1241 if (!jt->is_exiting() && thread_oop != NULL) {
1242 ResourceMark rm;
1243 _collector.fill_frames(_jthread, jt, thread_oop);
1244 _collector.allocate_and_fill_stacks(1);
1245 }
1246 }
1247
1248 void
1249 VM_GetAllStackTraces::doit() {
1250 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
1251
1252 ResourceMark rm;
1253 _final_thread_count = 0;
1254 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *jt = jtiwh.next(); ) {
1255 oop thread_oop = jt->threadObj();
1256 if (thread_oop != NULL &&
1257 !jt->is_exiting() &&
1258 java_lang_Thread::is_alive(thread_oop) &&
1259 !jt->is_hidden_from_external_view()) {
1260 ++_final_thread_count;
1261 // Handle block of the calling thread is used to create local refs.
1262 _collector.fill_frames((jthread)JNIHandles::make_local(_calling_thread, thread_oop),
1263 jt, thread_oop);
1264 }
1265 }
1266 _collector.allocate_and_fill_stacks(_final_thread_count);
1267 }
1268
1269 // Verifies that the top frame is a java frame in an expected state.
1270 // Deoptimizes frame if needed.
1271 // Checks that the frame method signature matches the return type (tos).
1272 // HandleMark must be defined in the caller only.
1273 // It is to keep a ret_ob_h handle alive after return to the caller.
1274 jvmtiError
1275 JvmtiEnvBase::check_top_frame(Thread* current_thread, JavaThread* java_thread,
1276 jvalue value, TosState tos, Handle* ret_ob_h) {
1277 ResourceMark rm(current_thread);
1278
1279 vframe *vf = vframeForNoProcess(java_thread, 0);
1280 NULL_CHECK(vf, JVMTI_ERROR_NO_MORE_FRAMES);
1281
1282 javaVFrame *jvf = (javaVFrame*) vf;
1283 if (!vf->is_java_frame() || jvf->method()->is_native()) {
1284 return JVMTI_ERROR_OPAQUE_FRAME;
1285 }
1286
1287 // If the frame is a compiled one, need to deoptimize it.
1288 if (vf->is_compiled_frame()) {
1289 if (!vf->fr().can_be_deoptimized()) {
1290 return JVMTI_ERROR_OPAQUE_FRAME;
1291 }
1292 Deoptimization::deoptimize_frame(java_thread, jvf->fr().id());
1293 }
1294
1295 // Get information about method return type
1296 Symbol* signature = jvf->method()->signature();
1297
1298 ResultTypeFinder rtf(signature);
1299 TosState fr_tos = as_TosState(rtf.type());
1300 if (fr_tos != tos) {
1301 if (tos != itos || (fr_tos != btos && fr_tos != ztos && fr_tos != ctos && fr_tos != stos)) {
1302 return JVMTI_ERROR_TYPE_MISMATCH;
1303 }
1304 }
1305
1306 // Check that the jobject class matches the return type signature.
1307 jobject jobj = value.l;
1308 if (tos == atos && jobj != NULL) { // NULL reference is allowed
1309 Handle ob_h(current_thread, JNIHandles::resolve_external_guard(jobj));
1310 NULL_CHECK(ob_h, JVMTI_ERROR_INVALID_OBJECT);
1311 Klass* ob_k = ob_h()->klass();
1312 NULL_CHECK(ob_k, JVMTI_ERROR_INVALID_OBJECT);
1313
1314 // Method return type signature.
1315 char* ty_sign = 1 + strchr(signature->as_C_string(), JVM_SIGNATURE_ENDFUNC);
1316
1317 if (!VM_GetOrSetLocal::is_assignable(ty_sign, ob_k, current_thread)) {
1318 return JVMTI_ERROR_TYPE_MISMATCH;
1319 }
1320 *ret_ob_h = ob_h;
1321 }
1322 return JVMTI_ERROR_NONE;
1323 } /* end check_top_frame */
1324
1325
1326 // ForceEarlyReturn<type> follows the PopFrame approach in many aspects.
1327 // Main difference is on the last stage in the interpreter.
1328 // The PopFrame stops method execution to continue execution
1329 // from the same method call instruction.
1330 // The ForceEarlyReturn forces return from method so the execution
1331 // continues at the bytecode following the method call.
1332
1333 // java_thread - protected by ThreadsListHandle and pre-checked
1334
1335 jvmtiError
1336 JvmtiEnvBase::force_early_return(JavaThread* java_thread, jvalue value, TosState tos) {
1337 // retrieve or create the state
1338 JvmtiThreadState* state = JvmtiThreadState::state_for(java_thread);
1339 if (state == NULL) {
1340 return JVMTI_ERROR_THREAD_NOT_ALIVE;
1341 }
1342
1343 // Eagerly reallocate scalar replaced objects.
1344 JavaThread* current_thread = JavaThread::current();
1345 EscapeBarrier eb(true, current_thread, java_thread);
1346 if (!eb.deoptimize_objects(0)) {
1347 // Reallocation of scalar replaced objects failed -> return with error
1348 return JVMTI_ERROR_OUT_OF_MEMORY;
1349 }
1350
1351 SetForceEarlyReturn op(state, value, tos);
1352 if (java_thread == current_thread) {
1353 op.doit(java_thread, true /* self */);
1354 } else {
1355 Handshake::execute(&op, java_thread);
1356 }
1357 return op.result();
1358 }
1359
1360 void
1361 SetForceEarlyReturn::doit(Thread *target, bool self) {
1362 JavaThread* java_thread = target->as_Java_thread();
1363 Thread* current_thread = Thread::current();
1364 HandleMark hm(current_thread);
1365
1366 if (!self) {
1367 if (!java_thread->is_suspended()) {
1368 _result = JVMTI_ERROR_THREAD_NOT_SUSPENDED;
1369 return;
1370 }
1371 }
1372
1373 // Check to see if a ForceEarlyReturn was already in progress
1374 if (_state->is_earlyret_pending()) {
1375 // Probably possible for JVMTI clients to trigger this, but the
1376 // JPDA backend shouldn't allow this to happen
1377 _result = JVMTI_ERROR_INTERNAL;
1378 return;
1379 }
1380 {
1381 // The same as for PopFrame. Workaround bug:
1382 // 4812902: popFrame hangs if the method is waiting at a synchronize
1383 // Catch this condition and return an error to avoid hanging.
1384 // Now JVMTI spec allows an implementation to bail out with an opaque
1385 // frame error.
1386 OSThread* osThread = java_thread->osthread();
1387 if (osThread->get_state() == MONITOR_WAIT) {
1388 _result = JVMTI_ERROR_OPAQUE_FRAME;
1389 return;
1390 }
1391 }
1392
1393 Handle ret_ob_h;
1394 _result = JvmtiEnvBase::check_top_frame(current_thread, java_thread, _value, _tos, &ret_ob_h);
1395 if (_result != JVMTI_ERROR_NONE) {
1396 return;
1397 }
1398 assert(_tos != atos || _value.l == NULL || ret_ob_h() != NULL,
1399 "return object oop must not be NULL if jobject is not NULL");
1400
1401 // Update the thread state to reflect that the top frame must be
1402 // forced to return.
1403 // The current frame will be returned later when the suspended
1404 // thread is resumed and right before returning from VM to Java.
1405 // (see call_VM_base() in assembler_<cpu>.cpp).
1406
1407 _state->set_earlyret_pending();
1408 _state->set_earlyret_oop(ret_ob_h());
1409 _state->set_earlyret_value(_value, _tos);
1410
1411 // Set pending step flag for this early return.
1412 // It is cleared when next step event is posted.
1413 _state->set_pending_step_for_earlyret();
1414 }
1415
1416 void
1417 JvmtiMonitorClosure::do_monitor(ObjectMonitor* mon) {
1418 if ( _error != JVMTI_ERROR_NONE) {
1419 // Error occurred in previous iteration so no need to add
1420 // to the list.
1421 return;
1422 }
1423 // Filter out on stack monitors collected during stack walk.
1424 oop obj = mon->object();
1425 bool found = false;
1426 for (int j = 0; j < _owned_monitors_list->length(); j++) {
1427 jobject jobj = ((jvmtiMonitorStackDepthInfo*)_owned_monitors_list->at(j))->monitor;
1428 oop check = JNIHandles::resolve(jobj);
1429 if (check == obj) {
1430 // On stack monitor already collected during the stack walk.
1431 found = true;
1432 break;
1433 }
1434 }
1435 if (found == false) {
1436 // This is off stack monitor (e.g. acquired via jni MonitorEnter).
1437 jvmtiError err;
1438 jvmtiMonitorStackDepthInfo *jmsdi;
1439 err = _env->allocate(sizeof(jvmtiMonitorStackDepthInfo), (unsigned char **)&jmsdi);
1440 if (err != JVMTI_ERROR_NONE) {
1441 _error = err;
1442 return;
1443 }
1444 Handle hobj(Thread::current(), obj);
1445 jmsdi->monitor = _env->jni_reference(_calling_thread, hobj);
1446 // stack depth is unknown for this monitor.
1447 jmsdi->stack_depth = -1;
1448 _owned_monitors_list->append(jmsdi);
1449 }
1450 }
1451
1452 GrowableArray<OopHandle>* JvmtiModuleClosure::_tbl = NULL;
1453
1454 void JvmtiModuleClosure::do_module(ModuleEntry* entry) {
1455 assert_locked_or_safepoint(Module_lock);
1456 OopHandle module = entry->module_handle();
1457 guarantee(module.resolve() != NULL, "module object is NULL");
1458 _tbl->push(module);
1459 }
1460
1461 jvmtiError
1462 JvmtiModuleClosure::get_all_modules(JvmtiEnv* env, jint* module_count_ptr, jobject** modules_ptr) {
1463 ResourceMark rm;
1464 MutexLocker mcld(ClassLoaderDataGraph_lock);
1465 MutexLocker ml(Module_lock);
1466
1467 _tbl = new GrowableArray<OopHandle>(77);
1468 if (_tbl == NULL) {
1469 return JVMTI_ERROR_OUT_OF_MEMORY;
1470 }
1471
1472 // Iterate over all the modules loaded to the system.
1473 ClassLoaderDataGraph::modules_do(&do_module);
1474
1475 jint len = _tbl->length();
1476 guarantee(len > 0, "at least one module must be present");
1477
1478 jobject* array = (jobject*)env->jvmtiMalloc((jlong)(len * sizeof(jobject)));
1479 if (array == NULL) {
1480 return JVMTI_ERROR_OUT_OF_MEMORY;
1481 }
1482 for (jint idx = 0; idx < len; idx++) {
1483 array[idx] = JNIHandles::make_local(Thread::current(), _tbl->at(idx).resolve());
1484 }
1485 _tbl = NULL;
1486 *modules_ptr = array;
1487 *module_count_ptr = len;
1488 return JVMTI_ERROR_NONE;
1489 }
1490
1491 void
1492 UpdateForPopTopFrameClosure::doit(Thread *target, bool self) {
1493 Thread* current_thread = Thread::current();
1494 HandleMark hm(current_thread);
1495 JavaThread* java_thread = target->as_Java_thread();
1496 assert(java_thread == _state->get_thread(), "Must be");
1497
1498 if (!self && !java_thread->is_suspended()) {
1499 _result = JVMTI_ERROR_THREAD_NOT_SUSPENDED;
1500 return;
1501 }
1502
1503 // Check to see if a PopFrame was already in progress
1504 if (java_thread->popframe_condition() != JavaThread::popframe_inactive) {
1505 // Probably possible for JVMTI clients to trigger this, but the
1506 // JPDA backend shouldn't allow this to happen
1507 _result = JVMTI_ERROR_INTERNAL;
1508 return;
1509 }
1510
1511 // Was workaround bug
1512 // 4812902: popFrame hangs if the method is waiting at a synchronize
1513 // Catch this condition and return an error to avoid hanging.
1514 // Now JVMTI spec allows an implementation to bail out with an opaque frame error.
1515 OSThread* osThread = java_thread->osthread();
1516 if (osThread->get_state() == MONITOR_WAIT) {
1517 _result = JVMTI_ERROR_OPAQUE_FRAME;
1518 return;
1519 }
1520
1521 ResourceMark rm(current_thread);
1522 // Check if there is more than one Java frame in this thread, that the top two frames
1523 // are Java (not native) frames, and that there is no intervening VM frame
1524 int frame_count = 0;
1525 bool is_interpreted[2];
1526 intptr_t *frame_sp[2];
1527 // The 2-nd arg of constructor is needed to stop iterating at java entry frame.
1528 for (vframeStream vfs(java_thread, true, false /* process_frames */); !vfs.at_end(); vfs.next()) {
1529 methodHandle mh(current_thread, vfs.method());
1530 if (mh->is_native()) {
1531 _result = JVMTI_ERROR_OPAQUE_FRAME;
1532 return;
1533 }
1534 is_interpreted[frame_count] = vfs.is_interpreted_frame();
1535 frame_sp[frame_count] = vfs.frame_id();
1536 if (++frame_count > 1) break;
1537 }
1538 if (frame_count < 2) {
1539 // We haven't found two adjacent non-native Java frames on the top.
1540 // There can be two situations here:
1541 // 1. There are no more java frames
1542 // 2. Two top java frames are separated by non-java native frames
1543 if(JvmtiEnvBase::vframeForNoProcess(java_thread, 1) == NULL) {
1544 _result = JVMTI_ERROR_NO_MORE_FRAMES;
1545 return;
1546 } else {
1547 // Intervening non-java native or VM frames separate java frames.
1548 // Current implementation does not support this. See bug #5031735.
1549 // In theory it is possible to pop frames in such cases.
1550 _result = JVMTI_ERROR_OPAQUE_FRAME;
1551 return;
1552 }
1553 }
1554
1555 // If any of the top 2 frames is a compiled one, need to deoptimize it
1556 for (int i = 0; i < 2; i++) {
1557 if (!is_interpreted[i]) {
1558 Deoptimization::deoptimize_frame(java_thread, frame_sp[i]);
1559 }
1560 }
1561
1562 // Update the thread state to reflect that the top frame is popped
1563 // so that cur_stack_depth is maintained properly and all frameIDs
1564 // are invalidated.
1565 // The current frame will be popped later when the suspended thread
1566 // is resumed and right before returning from VM to Java.
1567 // (see call_VM_base() in assembler_<cpu>.cpp).
1568
1569 // It's fine to update the thread state here because no JVMTI events
1570 // shall be posted for this PopFrame.
1571
1572 if (!java_thread->is_exiting() && java_thread->threadObj() != NULL) {
1573 _state->update_for_pop_top_frame();
1574 java_thread->set_popframe_condition(JavaThread::popframe_pending_bit);
1575 // Set pending step flag for this popframe and it is cleared when next
1576 // step event is posted.
1577 _state->set_pending_step_for_popframe();
1578 _result = JVMTI_ERROR_NONE;
1579 }
1580 }
1581
1582 void
1583 SetFramePopClosure::doit(Thread *target, bool self) {
1584 ResourceMark rm;
1585 JavaThread* java_thread = target->as_Java_thread();
1586
1587 assert(_state->get_thread() == java_thread, "Must be");
1588
1589 if (!self && !java_thread->is_suspended()) {
1590 _result = JVMTI_ERROR_THREAD_NOT_SUSPENDED;
1591 return;
1592 }
1593
1594 vframe *vf = JvmtiEnvBase::vframeForNoProcess(java_thread, _depth);
1595 if (vf == NULL) {
1596 _result = JVMTI_ERROR_NO_MORE_FRAMES;
1597 return;
1598 }
1599
1600 if (!vf->is_java_frame() || ((javaVFrame*) vf)->method()->is_native()) {
1601 _result = JVMTI_ERROR_OPAQUE_FRAME;
1602 return;
1603 }
1604
1605 assert(vf->frame_pointer() != NULL, "frame pointer mustn't be NULL");
1606 if (java_thread->is_exiting() || java_thread->threadObj() == NULL) {
1607 return; /* JVMTI_ERROR_THREAD_NOT_ALIVE (default) */
1608 }
1609 int frame_number = _state->count_frames() - _depth;
1610 _state->env_thread_state((JvmtiEnvBase*)_env)->set_frame_pop(frame_number);
1611 _result = JVMTI_ERROR_NONE;
1612 }
1613
1614 void
1615 GetOwnedMonitorInfoClosure::do_thread(Thread *target) {
1616 JavaThread *jt = target->as_Java_thread();
1617 if (!jt->is_exiting() && (jt->threadObj() != NULL)) {
1618 _result = ((JvmtiEnvBase *)_env)->get_owned_monitors(_calling_thread,
1619 jt,
1620 _owned_monitors_list);
1621 }
1622 }
1623
1624 void
1625 GetCurrentContendedMonitorClosure::do_thread(Thread *target) {
1626 JavaThread *jt = target->as_Java_thread();
1627 if (!jt->is_exiting() && (jt->threadObj() != NULL)) {
1628 _result = ((JvmtiEnvBase *)_env)->get_current_contended_monitor(_calling_thread,
1629 jt,
1630 _owned_monitor_ptr);
1631 }
1632 }
1633
1634 void
1635 GetStackTraceClosure::do_thread(Thread *target) {
1636 JavaThread *jt = target->as_Java_thread();
1637 if (!jt->is_exiting() && jt->threadObj() != NULL) {
1638 _result = ((JvmtiEnvBase *)_env)->get_stack_trace(jt,
1639 _start_depth, _max_count,
1640 _frame_buffer, _count_ptr);
1641 }
1642 }
1643
1644 void
1645 GetFrameCountClosure::do_thread(Thread *target) {
1646 JavaThread* jt = _state->get_thread();
1647 assert(target == jt, "just checking");
1648 if (!jt->is_exiting() && jt->threadObj() != NULL) {
1649 _result = ((JvmtiEnvBase*)_env)->get_frame_count(_state, _count_ptr);
1650 }
1651 }
1652
1653 void
1654 GetFrameLocationClosure::do_thread(Thread *target) {
1655 JavaThread *jt = target->as_Java_thread();
1656 if (!jt->is_exiting() && jt->threadObj() != NULL) {
1657 _result = ((JvmtiEnvBase*)_env)->get_frame_location(jt, _depth,
1658 _method_ptr, _location_ptr);
1659 }
1660 }