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 // Revoke any biases before querying the mark word
974 BiasedLocking::revoke_at_safepoint(hobj);
975
976 address owner = NULL;
977 {
978 markWord mark = hobj()->mark();
979
980 if (!mark.has_monitor()) {
981 // this object has a lightweight monitor
982
983 if (mark.has_locker()) {
984 owner = (address)mark.locker(); // save the address of the Lock word
985 }
986 // implied else: no owner
987 } else {
988 // this object has a heavyweight monitor
989 mon = mark.monitor();
990
991 // The owner field of a heavyweight monitor may be NULL for no
992 // owner, a JavaThread * or it may still be the address of the
993 // Lock word in a JavaThread's stack. A monitor can be inflated
994 // by a non-owning JavaThread, but only the owning JavaThread
995 // can change the owner field from the Lock word to the
996 // JavaThread * and it may not have done that yet.
997 owner = (address)mon->owner();
998 }
999 }
1000
1001 if (owner != NULL) {
1002 // This monitor is owned so we have to find the owning JavaThread.
1003 owning_thread = Threads::owning_thread_from_monitor_owner(tlh.list(), owner);
1004 assert(owning_thread != NULL, "owning JavaThread must not be NULL");
1005 Handle th(current_thread, owning_thread->threadObj());
1006 ret.owner = (jthread)jni_reference(calling_thread, th);
1007 }
1008
1009 if (owning_thread != NULL) { // monitor is owned
1010 // The recursions field of a monitor does not reflect recursions
1011 // as lightweight locks before inflating the monitor are not included.
1012 // We have to count the number of recursive monitor entries the hard way.
1013 // We pass a handle to survive any GCs along the way.
1014 ret.entry_count = count_locked_objects(owning_thread, hobj);
1015 }
1016 // implied else: entry_count == 0
1017 }
1018
1019 jint nWant = 0, nWait = 0;
1020 if (mon != NULL) {
1021 // this object has a heavyweight monitor
1022 nWant = mon->contentions(); // # of threads contending for monitor
1023 nWait = mon->waiters(); // # of threads in Object.wait()
1024 ret.waiter_count = nWant + nWait;
1025 ret.notify_waiter_count = nWait;
1026 } else {
1027 // this object has a lightweight monitor
1028 ret.waiter_count = 0;
1029 ret.notify_waiter_count = 0;
1030 }
1031
1032 // Allocate memory for heavyweight and lightweight monitor.
1033 jvmtiError err;
1034 err = allocate(ret.waiter_count * sizeof(jthread *), (unsigned char**)&ret.waiters);
1035 if (err != JVMTI_ERROR_NONE) {
1036 return err;
1037 }
1038 err = allocate(ret.notify_waiter_count * sizeof(jthread *),
1039 (unsigned char**)&ret.notify_waiters);
1040 if (err != JVMTI_ERROR_NONE) {
1041 deallocate((unsigned char*)ret.waiters);
1042 return err;
1043 }
1044
1045 // now derive the rest of the fields
1046 if (mon != NULL) {
1047 // this object has a heavyweight monitor
1048
1049 // Number of waiters may actually be less than the waiter count.
1050 // So NULL out memory so that unused memory will be NULL.
1051 memset(ret.waiters, 0, ret.waiter_count * sizeof(jthread *));
1052 memset(ret.notify_waiters, 0, ret.notify_waiter_count * sizeof(jthread *));
1053
1054 if (ret.waiter_count > 0) {
1055 // we have contending and/or waiting threads
1056 if (nWant > 0) {
1057 // we have contending threads
1058 ResourceMark rm(current_thread);
1059 // get_pending_threads returns only java thread so we do not need to
1060 // check for non java threads.
1061 GrowableArray<JavaThread*>* wantList = Threads::get_pending_threads(tlh.list(), nWant, (address)mon);
1062 if (wantList->length() < nWant) {
1063 // robustness: the pending list has gotten smaller
1064 nWant = wantList->length();
1065 }
1066 for (int i = 0; i < nWant; i++) {
1067 JavaThread *pending_thread = wantList->at(i);
1068 Handle th(current_thread, pending_thread->threadObj());
1069 ret.waiters[i] = (jthread)jni_reference(calling_thread, th);
1070 }
1071 }
1072 if (nWait > 0) {
1073 // we have threads in Object.wait()
1074 int offset = nWant; // add after any contending threads
1075 ObjectWaiter *waiter = mon->first_waiter();
1076 for (int i = 0, j = 0; i < nWait; i++) {
1077 if (waiter == NULL) {
1078 // robustness: the waiting list has gotten smaller
1079 nWait = j;
1080 break;
1081 }
1082 JavaThread *w = mon->thread_of_waiter(waiter);
1083 if (w != NULL) {
1084 // If the thread was found on the ObjectWaiter list, then
1085 // it has not been notified. This thread can't change the
1086 // state of the monitor so it doesn't need to be suspended.
1087 Handle th(current_thread, w->threadObj());
1088 ret.waiters[offset + j] = (jthread)jni_reference(calling_thread, th);
1089 ret.notify_waiters[j++] = (jthread)jni_reference(calling_thread, th);
1090 }
1091 waiter = mon->next_waiter(waiter);
1092 }
1093 }
1094 } // ThreadsListHandle is destroyed here.
1095
1096 // Adjust count. nWant and nWait count values may be less than original.
1097 ret.waiter_count = nWant + nWait;
1098 ret.notify_waiter_count = nWait;
1099 } else {
1100 // this object has a lightweight monitor and we have nothing more
1101 // to do here because the defaults are just fine.
1102 }
1103
1104 // we don't update return parameter unless everything worked
1105 *info_ptr = ret;
1106
1107 return JVMTI_ERROR_NONE;
1108 }
1109
1110 ResourceTracker::ResourceTracker(JvmtiEnv* env) {
1111 _env = env;
1112 _allocations = new (ResourceObj::C_HEAP, mtServiceability) GrowableArray<unsigned char*>(20, mtServiceability);
1113 _failed = false;
1114 }
1115 ResourceTracker::~ResourceTracker() {
1116 if (_failed) {
1117 for (int i=0; i<_allocations->length(); i++) {
1118 _env->deallocate(_allocations->at(i));
1119 }
1120 }
1121 delete _allocations;
1122 }
1123
1124 jvmtiError ResourceTracker::allocate(jlong size, unsigned char** mem_ptr) {
1125 unsigned char *ptr;
1126 jvmtiError err = _env->allocate(size, &ptr);
1127 if (err == JVMTI_ERROR_NONE) {
1128 _allocations->append(ptr);
1129 *mem_ptr = ptr;
1130 } else {
1131 *mem_ptr = NULL;
1132 _failed = true;
1133 }
1134 return err;
1135 }
1136
1137 unsigned char* ResourceTracker::allocate(jlong size) {
1138 unsigned char* ptr;
1139 allocate(size, &ptr);
1140 return ptr;
1141 }
1142
1143 char* ResourceTracker::strdup(const char* str) {
1144 char *dup_str = (char*)allocate(strlen(str)+1);
1145 if (dup_str != NULL) {
1146 strcpy(dup_str, str);
1147 }
1148 return dup_str;
1149 }
1150
1151 struct StackInfoNode {
1152 struct StackInfoNode *next;
1153 jvmtiStackInfo info;
1154 };
1155
1156 // Create a jvmtiStackInfo inside a linked list node and create a
1157 // buffer for the frame information, both allocated as resource objects.
1158 // Fill in both the jvmtiStackInfo and the jvmtiFrameInfo.
1159 // Note that either or both of thr and thread_oop
1160 // may be null if the thread is new or has exited.
1161 void
1162 MultipleStackTracesCollector::fill_frames(jthread jt, JavaThread *thr, oop thread_oop) {
1163 #ifdef ASSERT
1164 Thread *current_thread = Thread::current();
1165 assert(SafepointSynchronize::is_at_safepoint() ||
1166 thr->is_handshake_safe_for(current_thread),
1167 "call by myself / at safepoint / at handshake");
1168 #endif
1169
1170 jint state = 0;
1171 struct StackInfoNode *node = NEW_RESOURCE_OBJ(struct StackInfoNode);
1172 jvmtiStackInfo *infop = &(node->info);
1173 node->next = head();
1174 set_head(node);
1175 infop->frame_count = 0;
1176 infop->thread = jt;
1177
1178 if (thread_oop != NULL) {
1179 // get most state bits
1180 state = (jint)java_lang_Thread::get_thread_status(thread_oop);
1181 }
1182
1183 if (thr != NULL) { // add more state bits if there is a JavaThead to query
1184 if (thr->is_suspended()) {
1185 state |= JVMTI_THREAD_STATE_SUSPENDED;
1186 }
1187 JavaThreadState jts = thr->thread_state();
1188 if (jts == _thread_in_native) {
1189 state |= JVMTI_THREAD_STATE_IN_NATIVE;
1190 }
1191 if (thr->is_interrupted(false)) {
1192 state |= JVMTI_THREAD_STATE_INTERRUPTED;
1193 }
1194 }
1195 infop->state = state;
1196
1197 if (thr != NULL && (state & JVMTI_THREAD_STATE_ALIVE) != 0) {
1198 infop->frame_buffer = NEW_RESOURCE_ARRAY(jvmtiFrameInfo, max_frame_count());
1199 env()->get_stack_trace(thr, 0, max_frame_count(),
1200 infop->frame_buffer, &(infop->frame_count));
1201 } else {
1202 infop->frame_buffer = NULL;
1203 infop->frame_count = 0;
1204 }
1205 _frame_count_total += infop->frame_count;
1206 }
1207
1208 // Based on the stack information in the linked list, allocate memory
1209 // block to return and fill it from the info in the linked list.
1210 void
1211 MultipleStackTracesCollector::allocate_and_fill_stacks(jint thread_count) {
1212 // do I need to worry about alignment issues?
1213 jlong alloc_size = thread_count * sizeof(jvmtiStackInfo)
1214 + _frame_count_total * sizeof(jvmtiFrameInfo);
1215 env()->allocate(alloc_size, (unsigned char **)&_stack_info);
1216
1217 // pointers to move through the newly allocated space as it is filled in
1218 jvmtiStackInfo *si = _stack_info + thread_count; // bottom of stack info
1219 jvmtiFrameInfo *fi = (jvmtiFrameInfo *)si; // is the top of frame info
1220
1221 // copy information in resource area into allocated buffer
1222 // insert stack info backwards since linked list is backwards
1223 // insert frame info forwards
1224 // walk the StackInfoNodes
1225 for (struct StackInfoNode *sin = head(); sin != NULL; sin = sin->next) {
1226 jint frame_count = sin->info.frame_count;
1227 size_t frames_size = frame_count * sizeof(jvmtiFrameInfo);
1228 --si;
1229 memcpy(si, &(sin->info), sizeof(jvmtiStackInfo));
1230 if (frames_size == 0) {
1231 si->frame_buffer = NULL;
1232 } else {
1233 memcpy(fi, sin->info.frame_buffer, frames_size);
1234 si->frame_buffer = fi; // point to the new allocated copy of the frames
1235 fi += frame_count;
1236 }
1237 }
1238 assert(si == _stack_info, "the last copied stack info must be the first record");
1239 assert((unsigned char *)fi == ((unsigned char *)_stack_info) + alloc_size,
1240 "the last copied frame info must be the last record");
1241 }
1242
1243
1244 void
1245 VM_GetThreadListStackTraces::doit() {
1246 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
1247
1248 ResourceMark rm;
1249 ThreadsListHandle tlh;
1250 for (int i = 0; i < _thread_count; ++i) {
1251 jthread jt = _thread_list[i];
1252 JavaThread* java_thread = NULL;
1253 oop thread_oop = NULL;
1254 jvmtiError err = JvmtiExport::cv_external_thread_to_JavaThread(tlh.list(), jt, &java_thread, &thread_oop);
1255 if (err != JVMTI_ERROR_NONE) {
1256 // We got an error code so we don't have a JavaThread *, but
1257 // only return an error from here if we didn't get a valid
1258 // thread_oop.
1259 if (thread_oop == NULL) {
1260 _collector.set_result(err);
1261 return;
1262 }
1263 // We have a valid thread_oop.
1264 }
1265 _collector.fill_frames(jt, java_thread, thread_oop);
1266 }
1267 _collector.allocate_and_fill_stacks(_thread_count);
1268 }
1269
1270 void
1271 GetSingleStackTraceClosure::do_thread(Thread *target) {
1272 JavaThread *jt = target->as_Java_thread();
1273 oop thread_oop = jt->threadObj();
1274
1275 if (!jt->is_exiting() && thread_oop != NULL) {
1276 ResourceMark rm;
1277 _collector.fill_frames(_jthread, jt, thread_oop);
1278 _collector.allocate_and_fill_stacks(1);
1279 }
1280 }
1281
1282 void
1283 VM_GetAllStackTraces::doit() {
1284 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
1285
1286 ResourceMark rm;
1287 _final_thread_count = 0;
1288 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *jt = jtiwh.next(); ) {
1289 oop thread_oop = jt->threadObj();
1290 if (thread_oop != NULL &&
1291 !jt->is_exiting() &&
1292 java_lang_Thread::is_alive(thread_oop) &&
1293 !jt->is_hidden_from_external_view()) {
1294 ++_final_thread_count;
1295 // Handle block of the calling thread is used to create local refs.
1296 _collector.fill_frames((jthread)JNIHandles::make_local(_calling_thread, thread_oop),
1297 jt, thread_oop);
1298 }
1299 }
1300 _collector.allocate_and_fill_stacks(_final_thread_count);
1301 }
1302
1303 // Verifies that the top frame is a java frame in an expected state.
1304 // Deoptimizes frame if needed.
1305 // Checks that the frame method signature matches the return type (tos).
1306 // HandleMark must be defined in the caller only.
1307 // It is to keep a ret_ob_h handle alive after return to the caller.
1308 jvmtiError
1309 JvmtiEnvBase::check_top_frame(Thread* current_thread, JavaThread* java_thread,
1310 jvalue value, TosState tos, Handle* ret_ob_h) {
1311 ResourceMark rm(current_thread);
1312
1313 vframe *vf = vframeForNoProcess(java_thread, 0);
1314 NULL_CHECK(vf, JVMTI_ERROR_NO_MORE_FRAMES);
1315
1316 javaVFrame *jvf = (javaVFrame*) vf;
1317 if (!vf->is_java_frame() || jvf->method()->is_native()) {
1318 return JVMTI_ERROR_OPAQUE_FRAME;
1319 }
1320
1321 // If the frame is a compiled one, need to deoptimize it.
1322 if (vf->is_compiled_frame()) {
1323 if (!vf->fr().can_be_deoptimized()) {
1324 return JVMTI_ERROR_OPAQUE_FRAME;
1325 }
1326 Deoptimization::deoptimize_frame(java_thread, jvf->fr().id());
1327 }
1328
1329 // Get information about method return type
1330 Symbol* signature = jvf->method()->signature();
1331
1332 ResultTypeFinder rtf(signature);
1333 TosState fr_tos = as_TosState(rtf.type());
1334 if (fr_tos != tos) {
1335 if (tos != itos || (fr_tos != btos && fr_tos != ztos && fr_tos != ctos && fr_tos != stos)) {
1336 return JVMTI_ERROR_TYPE_MISMATCH;
1337 }
1338 }
1339
1340 // Check that the jobject class matches the return type signature.
1341 jobject jobj = value.l;
1342 if (tos == atos && jobj != NULL) { // NULL reference is allowed
1343 Handle ob_h(current_thread, JNIHandles::resolve_external_guard(jobj));
1344 NULL_CHECK(ob_h, JVMTI_ERROR_INVALID_OBJECT);
1345 Klass* ob_k = ob_h()->klass();
1346 NULL_CHECK(ob_k, JVMTI_ERROR_INVALID_OBJECT);
1347
1348 // Method return type signature.
1349 char* ty_sign = 1 + strchr(signature->as_C_string(), JVM_SIGNATURE_ENDFUNC);
1350
1351 if (!VM_GetOrSetLocal::is_assignable(ty_sign, ob_k, current_thread)) {
1352 return JVMTI_ERROR_TYPE_MISMATCH;
1353 }
1354 *ret_ob_h = ob_h;
1355 }
1356 return JVMTI_ERROR_NONE;
1357 } /* end check_top_frame */
1358
1359
1360 // ForceEarlyReturn<type> follows the PopFrame approach in many aspects.
1361 // Main difference is on the last stage in the interpreter.
1362 // The PopFrame stops method execution to continue execution
1363 // from the same method call instruction.
1364 // The ForceEarlyReturn forces return from method so the execution
1365 // continues at the bytecode following the method call.
1366
1367 // java_thread - protected by ThreadsListHandle and pre-checked
1368
1369 jvmtiError
1370 JvmtiEnvBase::force_early_return(JavaThread* java_thread, jvalue value, TosState tos) {
1371 // retrieve or create the state
1372 JvmtiThreadState* state = JvmtiThreadState::state_for(java_thread);
1373 if (state == NULL) {
1374 return JVMTI_ERROR_THREAD_NOT_ALIVE;
1375 }
1376
1377 // Eagerly reallocate scalar replaced objects.
1378 JavaThread* current_thread = JavaThread::current();
1379 EscapeBarrier eb(true, current_thread, java_thread);
1380 if (!eb.deoptimize_objects(0)) {
1381 // Reallocation of scalar replaced objects failed -> return with error
1382 return JVMTI_ERROR_OUT_OF_MEMORY;
1383 }
1384
1385 SetForceEarlyReturn op(state, value, tos);
1386 if (java_thread == current_thread) {
1387 op.doit(java_thread, true /* self */);
1388 } else {
1389 Handshake::execute(&op, java_thread);
1390 }
1391 return op.result();
1392 }
1393
1394 void
1395 SetForceEarlyReturn::doit(Thread *target, bool self) {
1396 JavaThread* java_thread = target->as_Java_thread();
1397 Thread* current_thread = Thread::current();
1398 HandleMark hm(current_thread);
1399
1400 if (!self) {
1401 if (!java_thread->is_suspended()) {
1402 _result = JVMTI_ERROR_THREAD_NOT_SUSPENDED;
1403 return;
1404 }
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 _result = JVMTI_ERROR_INTERNAL;
1412 return;
1413 }
1414 {
1415 // The same as for PopFrame. Workaround bug:
1416 // 4812902: popFrame hangs if the method is waiting at a synchronize
1417 // Catch this condition and return an error to avoid hanging.
1418 // Now JVMTI spec allows an implementation to bail out with an opaque
1419 // frame error.
1420 OSThread* osThread = java_thread->osthread();
1421 if (osThread->get_state() == MONITOR_WAIT) {
1422 _result = JVMTI_ERROR_OPAQUE_FRAME;
1423 return;
1424 }
1425 }
1426
1427 Handle ret_ob_h;
1428 _result = JvmtiEnvBase::check_top_frame(current_thread, java_thread, _value, _tos, &ret_ob_h);
1429 if (_result != JVMTI_ERROR_NONE) {
1430 return;
1431 }
1432 assert(_tos != atos || _value.l == NULL || ret_ob_h() != NULL,
1433 "return object oop must not be NULL if jobject is not NULL");
1434
1435 // Update the thread state to reflect that the top frame must be
1436 // forced to return.
1437 // The current frame will be returned later when the suspended
1438 // thread is resumed and right before returning from VM to Java.
1439 // (see call_VM_base() in assembler_<cpu>.cpp).
1440
1441 _state->set_earlyret_pending();
1442 _state->set_earlyret_oop(ret_ob_h());
1443 _state->set_earlyret_value(_value, _tos);
1444
1445 // Set pending step flag for this early return.
1446 // It is cleared when next step event is posted.
1447 _state->set_pending_step_for_earlyret();
1448 }
1449
1450 void
1451 JvmtiMonitorClosure::do_monitor(ObjectMonitor* mon) {
1452 if ( _error != JVMTI_ERROR_NONE) {
1453 // Error occurred in previous iteration so no need to add
1454 // to the list.
1455 return;
1456 }
1457 // Filter out on stack monitors collected during stack walk.
1458 oop obj = 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 GrowableArray<OopHandle>* JvmtiModuleClosure::_tbl = NULL;
1487
1488 void JvmtiModuleClosure::do_module(ModuleEntry* entry) {
1489 assert_locked_or_safepoint(Module_lock);
1490 OopHandle module = entry->module_handle();
1491 guarantee(module.resolve() != NULL, "module object is NULL");
1492 _tbl->push(module);
1493 }
1494
1495 jvmtiError
1496 JvmtiModuleClosure::get_all_modules(JvmtiEnv* env, jint* module_count_ptr, jobject** modules_ptr) {
1497 ResourceMark rm;
1498 MutexLocker mcld(ClassLoaderDataGraph_lock);
1499 MutexLocker ml(Module_lock);
1500
1501 _tbl = new GrowableArray<OopHandle>(77);
1502 if (_tbl == NULL) {
1503 return JVMTI_ERROR_OUT_OF_MEMORY;
1504 }
1505
1506 // Iterate over all the modules loaded to the system.
1507 ClassLoaderDataGraph::modules_do(&do_module);
1508
1509 jint len = _tbl->length();
1510 guarantee(len > 0, "at least one module must be present");
1511
1512 jobject* array = (jobject*)env->jvmtiMalloc((jlong)(len * sizeof(jobject)));
1513 if (array == NULL) {
1514 return JVMTI_ERROR_OUT_OF_MEMORY;
1515 }
1516 for (jint idx = 0; idx < len; idx++) {
1517 array[idx] = JNIHandles::make_local(Thread::current(), _tbl->at(idx).resolve());
1518 }
1519 _tbl = NULL;
1520 *modules_ptr = array;
1521 *module_count_ptr = len;
1522 return JVMTI_ERROR_NONE;
1523 }
1524
1525 void
1526 UpdateForPopTopFrameClosure::doit(Thread *target, bool self) {
1527 Thread* current_thread = Thread::current();
1528 HandleMark hm(current_thread);
1529 JavaThread* java_thread = target->as_Java_thread();
1530 assert(java_thread == _state->get_thread(), "Must be");
1531
1532 if (!self && !java_thread->is_suspended()) {
1533 _result = JVMTI_ERROR_THREAD_NOT_SUSPENDED;
1534 return;
1535 }
1536
1537 // Check to see if a PopFrame was already in progress
1538 if (java_thread->popframe_condition() != JavaThread::popframe_inactive) {
1539 // Probably possible for JVMTI clients to trigger this, but the
1540 // JPDA backend shouldn't allow this to happen
1541 _result = JVMTI_ERROR_INTERNAL;
1542 return;
1543 }
1544
1545 // Was workaround bug
1546 // 4812902: popFrame hangs if the method is waiting at a synchronize
1547 // Catch this condition and return an error to avoid hanging.
1548 // Now JVMTI spec allows an implementation to bail out with an opaque frame error.
1549 OSThread* osThread = java_thread->osthread();
1550 if (osThread->get_state() == MONITOR_WAIT) {
1551 _result = JVMTI_ERROR_OPAQUE_FRAME;
1552 return;
1553 }
1554
1555 ResourceMark rm(current_thread);
1556 // Check if there is more than one Java frame in this thread, that the top two frames
1557 // are Java (not native) frames, and that there is no intervening VM frame
1558 int frame_count = 0;
1559 bool is_interpreted[2];
1560 intptr_t *frame_sp[2];
1561 // The 2-nd arg of constructor is needed to stop iterating at java entry frame.
1562 for (vframeStream vfs(java_thread, true, false /* process_frames */); !vfs.at_end(); vfs.next()) {
1563 methodHandle mh(current_thread, vfs.method());
1564 if (mh->is_native()) {
1565 _result = JVMTI_ERROR_OPAQUE_FRAME;
1566 return;
1567 }
1568 is_interpreted[frame_count] = vfs.is_interpreted_frame();
1569 frame_sp[frame_count] = vfs.frame_id();
1570 if (++frame_count > 1) break;
1571 }
1572 if (frame_count < 2) {
1573 // We haven't found two adjacent non-native Java frames on the top.
1574 // There can be two situations here:
1575 // 1. There are no more java frames
1576 // 2. Two top java frames are separated by non-java native frames
1577 if(JvmtiEnvBase::vframeForNoProcess(java_thread, 1) == NULL) {
1578 _result = JVMTI_ERROR_NO_MORE_FRAMES;
1579 return;
1580 } else {
1581 // Intervening non-java native or VM frames separate java frames.
1582 // Current implementation does not support this. See bug #5031735.
1583 // In theory it is possible to pop frames in such cases.
1584 _result = JVMTI_ERROR_OPAQUE_FRAME;
1585 return;
1586 }
1587 }
1588
1589 // If any of the top 2 frames is a compiled one, need to deoptimize it
1590 for (int i = 0; i < 2; i++) {
1591 if (!is_interpreted[i]) {
1592 Deoptimization::deoptimize_frame(java_thread, frame_sp[i]);
1593 }
1594 }
1595
1596 // Update the thread state to reflect that the top frame is popped
1597 // so that cur_stack_depth is maintained properly and all frameIDs
1598 // are invalidated.
1599 // The current frame will be popped later when the suspended thread
1600 // is resumed and right before returning from VM to Java.
1601 // (see call_VM_base() in assembler_<cpu>.cpp).
1602
1603 // It's fine to update the thread state here because no JVMTI events
1604 // shall be posted for this PopFrame.
1605
1606 if (!java_thread->is_exiting() && java_thread->threadObj() != NULL) {
1607 _state->update_for_pop_top_frame();
1608 java_thread->set_popframe_condition(JavaThread::popframe_pending_bit);
1609 // Set pending step flag for this popframe and it is cleared when next
1610 // step event is posted.
1611 _state->set_pending_step_for_popframe();
1612 _result = JVMTI_ERROR_NONE;
1613 }
1614 }
1615
1616 void
1617 SetFramePopClosure::doit(Thread *target, bool self) {
1618 ResourceMark rm;
1619 JavaThread* java_thread = target->as_Java_thread();
1620
1621 assert(_state->get_thread() == java_thread, "Must be");
1622
1623 if (!self && !java_thread->is_suspended()) {
1624 _result = JVMTI_ERROR_THREAD_NOT_SUSPENDED;
1625 return;
1626 }
1627
1628 vframe *vf = JvmtiEnvBase::vframeForNoProcess(java_thread, _depth);
1629 if (vf == NULL) {
1630 _result = JVMTI_ERROR_NO_MORE_FRAMES;
1631 return;
1632 }
1633
1634 if (!vf->is_java_frame() || ((javaVFrame*) vf)->method()->is_native()) {
1635 _result = JVMTI_ERROR_OPAQUE_FRAME;
1636 return;
1637 }
1638
1639 assert(vf->frame_pointer() != NULL, "frame pointer mustn't be NULL");
1640 if (java_thread->is_exiting() || java_thread->threadObj() == NULL) {
1641 return; /* JVMTI_ERROR_THREAD_NOT_ALIVE (default) */
1642 }
1643 int frame_number = _state->count_frames() - _depth;
1644 _state->env_thread_state((JvmtiEnvBase*)_env)->set_frame_pop(frame_number);
1645 _result = JVMTI_ERROR_NONE;
1646 }
1647
1648 void
1649 GetOwnedMonitorInfoClosure::do_thread(Thread *target) {
1650 JavaThread *jt = target->as_Java_thread();
1651 if (!jt->is_exiting() && (jt->threadObj() != NULL)) {
1652 _result = ((JvmtiEnvBase *)_env)->get_owned_monitors(_calling_thread,
1653 jt,
1654 _owned_monitors_list);
1655 }
1656 }
1657
1658 void
1659 GetCurrentContendedMonitorClosure::do_thread(Thread *target) {
1660 JavaThread *jt = target->as_Java_thread();
1661 if (!jt->is_exiting() && (jt->threadObj() != NULL)) {
1662 _result = ((JvmtiEnvBase *)_env)->get_current_contended_monitor(_calling_thread,
1663 jt,
1664 _owned_monitor_ptr);
1665 }
1666 }
1667
1668 void
1669 GetStackTraceClosure::do_thread(Thread *target) {
1670 JavaThread *jt = target->as_Java_thread();
1671 if (!jt->is_exiting() && jt->threadObj() != NULL) {
1672 _result = ((JvmtiEnvBase *)_env)->get_stack_trace(jt,
1673 _start_depth, _max_count,
1674 _frame_buffer, _count_ptr);
1675 }
1676 }
1677
1678 void
1679 GetFrameCountClosure::do_thread(Thread *target) {
1680 JavaThread* jt = _state->get_thread();
1681 assert(target == jt, "just checking");
1682 if (!jt->is_exiting() && jt->threadObj() != NULL) {
1683 _result = ((JvmtiEnvBase*)_env)->get_frame_count(_state, _count_ptr);
1684 }
1685 }
1686
1687 void
1688 GetFrameLocationClosure::do_thread(Thread *target) {
1689 JavaThread *jt = target->as_Java_thread();
1690 if (!jt->is_exiting() && jt->threadObj() != NULL) {
1691 _result = ((JvmtiEnvBase*)_env)->get_frame_location(jt, _depth,
1692 _method_ptr, _location_ptr);
1693 }
1694 }