1 /*
2 * Copyright (c) 2003, 2018, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "classfile/systemDictionary.hpp"
27 #include "jvmtifiles/jvmtiEnv.hpp"
28 #include "memory/resourceArea.hpp"
29 #include "oops/objArrayKlass.hpp"
30 #include "oops/objArrayOop.hpp"
31 #include "oops/oop.inline.hpp"
32 #include "prims/jvmtiEnvBase.hpp"
33 #include "prims/jvmtiEventController.inline.hpp"
34 #include "prims/jvmtiExtensions.hpp"
35 #include "prims/jvmtiImpl.hpp"
36 #include "prims/jvmtiManageCapabilities.hpp"
37 #include "prims/jvmtiTagMap.hpp"
38 #include "prims/jvmtiThreadState.inline.hpp"
39 #include "runtime/biasedLocking.hpp"
40 #include "runtime/deoptimization.hpp"
41 #include "runtime/interfaceSupport.inline.hpp"
42 #include "runtime/jfieldIDWorkaround.hpp"
43 #include "runtime/jniHandles.inline.hpp"
44 #include "runtime/objectMonitor.hpp"
45 #include "runtime/objectMonitor.inline.hpp"
46 #include "runtime/signature.hpp"
47 #include "runtime/thread.inline.hpp"
48 #include "runtime/threadSMR.hpp"
49 #include "runtime/vframe.hpp"
50 #include "runtime/vframe_hp.hpp"
51 #include "runtime/vmThread.hpp"
52 #include "runtime/vm_operations.hpp"
53
54 ///////////////////////////////////////////////////////////////
55 //
56 // JvmtiEnvBase
57 //
58
59 JvmtiEnvBase* JvmtiEnvBase::_head_environment = NULL;
60
61 bool JvmtiEnvBase::_globally_initialized = false;
62 volatile bool JvmtiEnvBase::_needs_clean_up = false;
63
64 jvmtiPhase JvmtiEnvBase::_phase = JVMTI_PHASE_PRIMORDIAL;
65
66 volatile int JvmtiEnvBase::_dying_thread_env_iteration_count = 0;
67
68 extern jvmtiInterface_1_ jvmti_Interface;
69 extern jvmtiInterface_1_ jvmtiTrace_Interface;
70
71
72 // perform initializations that must occur before any JVMTI environments
73 // are released but which should only be initialized once (no matter
74 // how many environments are created).
75 void
76 JvmtiEnvBase::globally_initialize() {
77 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
78 assert(_globally_initialized == false, "bad call");
79
80 JvmtiManageCapabilities::initialize();
81
82 // register extension functions and events
83 JvmtiExtensions::register_extensions();
84
85 #ifdef JVMTI_TRACE
86 JvmtiTrace::initialize();
87 #endif
88
89 _globally_initialized = true;
90 }
91
92
93 void
94 JvmtiEnvBase::initialize() {
95 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
96
97 // Add this environment to the end of the environment list (order is important)
98 {
99 // This block of code must not contain any safepoints, as list deallocation
100 // (which occurs at a safepoint) cannot occur simultaneously with this list
101 // addition. Note: NoSafepointVerifier cannot, currently, be used before
102 // threads exist.
103 JvmtiEnvIterator it;
104 JvmtiEnvBase *previous_env = NULL;
105 for (JvmtiEnvBase* env = it.first(); env != NULL; env = it.next(env)) {
106 previous_env = env;
107 }
108 if (previous_env == NULL) {
109 _head_environment = this;
110 } else {
111 previous_env->set_next_environment(this);
112 }
113 }
114
115 if (_globally_initialized == false) {
116 globally_initialize();
117 }
118 }
119
120 jvmtiPhase
121 JvmtiEnvBase::phase() {
122 // For the JVMTI environments possessed the can_generate_early_vmstart:
123 // replace JVMTI_PHASE_PRIMORDIAL with JVMTI_PHASE_START
124 if (_phase == JVMTI_PHASE_PRIMORDIAL &&
125 JvmtiExport::early_vmstart_recorded() &&
126 early_vmstart_env()) {
127 return JVMTI_PHASE_START;
128 }
129 return _phase; // Normal case
130 }
131
132 bool
133 JvmtiEnvBase::is_valid() {
134 jint value = 0;
135
136 // This object might not be a JvmtiEnvBase so we can't assume
137 // the _magic field is properly aligned. Get the value in a safe
138 // way and then check against JVMTI_MAGIC.
139
140 switch (sizeof(_magic)) {
141 case 2:
142 value = Bytes::get_native_u2((address)&_magic);
143 break;
144
145 case 4:
146 value = Bytes::get_native_u4((address)&_magic);
147 break;
148
149 case 8:
150 value = Bytes::get_native_u8((address)&_magic);
151 break;
152
153 default:
154 guarantee(false, "_magic field is an unexpected size");
155 }
156
157 return value == JVMTI_MAGIC;
158 }
159
160
161 bool
162 JvmtiEnvBase::use_version_1_0_semantics() {
163 int major, minor, micro;
164
165 JvmtiExport::decode_version_values(_version, &major, &minor, µ);
166 return major == 1 && minor == 0; // micro version doesn't matter here
167 }
168
169
170 bool
171 JvmtiEnvBase::use_version_1_1_semantics() {
172 int major, minor, micro;
173
174 JvmtiExport::decode_version_values(_version, &major, &minor, µ);
175 return major == 1 && minor == 1; // micro version doesn't matter here
176 }
177
178 bool
179 JvmtiEnvBase::use_version_1_2_semantics() {
180 int major, minor, micro;
181
182 JvmtiExport::decode_version_values(_version, &major, &minor, µ);
183 return major == 1 && minor == 2; // micro version doesn't matter here
184 }
185
186
187 JvmtiEnvBase::JvmtiEnvBase(jint version) : _env_event_enable() {
188 _version = version;
189 _env_local_storage = NULL;
190 _tag_map = NULL;
191 _native_method_prefix_count = 0;
192 _native_method_prefixes = NULL;
193 _next = NULL;
194 _class_file_load_hook_ever_enabled = false;
195
196 // Moot since ClassFileLoadHook not yet enabled.
197 // But "true" will give a more predictable ClassFileLoadHook behavior
198 // for environment creation during ClassFileLoadHook.
199 _is_retransformable = true;
200
201 // all callbacks initially NULL
202 memset(&_event_callbacks,0,sizeof(jvmtiEventCallbacks));
203
204 // all capabilities initially off
205 memset(&_current_capabilities, 0, sizeof(_current_capabilities));
206
207 // all prohibited capabilities initially off
208 memset(&_prohibited_capabilities, 0, sizeof(_prohibited_capabilities));
209
210 _magic = JVMTI_MAGIC;
211
212 JvmtiEventController::env_initialize((JvmtiEnv*)this);
213
214 #ifdef JVMTI_TRACE
215 _jvmti_external.functions = TraceJVMTI != NULL ? &jvmtiTrace_Interface : &jvmti_Interface;
216 #else
217 _jvmti_external.functions = &jvmti_Interface;
218 #endif
219 }
220
221
222 void
223 JvmtiEnvBase::dispose() {
224
225 #ifdef JVMTI_TRACE
226 JvmtiTrace::shutdown();
227 #endif
228
229 // Dispose of event info and let the event controller call us back
230 // in a locked state (env_dispose, below)
231 JvmtiEventController::env_dispose(this);
232 }
233
234 void
235 JvmtiEnvBase::env_dispose() {
236 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
237
238 // We have been entered with all events disabled on this environment.
239 // A race to re-enable events (by setting callbacks) is prevented by
240 // checking for a valid environment when setting callbacks (while
241 // holding the JvmtiThreadState_lock).
242
243 // Mark as invalid.
244 _magic = DISPOSED_MAGIC;
245
246 // Relinquish all capabilities.
247 jvmtiCapabilities *caps = get_capabilities();
248 JvmtiManageCapabilities::relinquish_capabilities(caps, caps, caps);
249
250 // Same situation as with events (see above)
251 set_native_method_prefixes(0, NULL);
252
253 JvmtiTagMap* tag_map_to_deallocate = _tag_map;
254 set_tag_map(NULL);
255 // A tag map can be big, deallocate it now
256 if (tag_map_to_deallocate != NULL) {
257 delete tag_map_to_deallocate;
258 }
259
260 _needs_clean_up = true;
261 }
262
263
264 JvmtiEnvBase::~JvmtiEnvBase() {
265 assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
266
267 // There is a small window of time during which the tag map of a
268 // disposed environment could have been reallocated.
269 // Make sure it is gone.
270 JvmtiTagMap* tag_map_to_deallocate = _tag_map;
271 set_tag_map(NULL);
272 // A tag map can be big, deallocate it now
273 if (tag_map_to_deallocate != NULL) {
274 delete tag_map_to_deallocate;
275 }
276
277 _magic = BAD_MAGIC;
278 }
279
280
281 void
282 JvmtiEnvBase::periodic_clean_up() {
283 assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
284
285 // JvmtiEnvBase reference is saved in JvmtiEnvThreadState. So
286 // clean up JvmtiThreadState before deleting JvmtiEnv pointer.
287 JvmtiThreadState::periodic_clean_up();
288
289 // Unlink all invalid environments from the list of environments
290 // and deallocate them
291 JvmtiEnvIterator it;
292 JvmtiEnvBase* previous_env = NULL;
293 JvmtiEnvBase* env = it.first();
294 while (env != NULL) {
295 if (env->is_valid()) {
296 previous_env = env;
297 env = it.next(env);
298 } else {
299 // This one isn't valid, remove it from the list and deallocate it
300 JvmtiEnvBase* defunct_env = env;
301 env = it.next(env);
302 if (previous_env == NULL) {
303 _head_environment = env;
304 } else {
305 previous_env->set_next_environment(env);
306 }
307 delete defunct_env;
308 }
309 }
310
311 }
312
313
314 void
315 JvmtiEnvBase::check_for_periodic_clean_up() {
316 assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
317
318 class ThreadInsideIterationClosure: public ThreadClosure {
319 private:
320 bool _inside;
321 public:
322 ThreadInsideIterationClosure() : _inside(false) {};
323
324 void do_thread(Thread* thread) {
325 _inside |= thread->is_inside_jvmti_env_iteration();
326 }
327
328 bool is_inside_jvmti_env_iteration() {
329 return _inside;
330 }
331 };
332
333 if (_needs_clean_up) {
334 // Check if we are currently iterating environment,
335 // deallocation should not occur if we are
336 ThreadInsideIterationClosure tiic;
337 Threads::threads_do(&tiic);
338 if (!tiic.is_inside_jvmti_env_iteration() &&
339 !is_inside_dying_thread_env_iteration()) {
340 _needs_clean_up = false;
341 JvmtiEnvBase::periodic_clean_up();
342 }
343 }
344 }
345
346
347 void
348 JvmtiEnvBase::record_first_time_class_file_load_hook_enabled() {
349 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(),
350 "sanity check");
351
352 if (!_class_file_load_hook_ever_enabled) {
353 _class_file_load_hook_ever_enabled = true;
354
355 if (get_capabilities()->can_retransform_classes) {
356 _is_retransformable = true;
357 } else {
358 _is_retransformable = false;
359
360 // cannot add retransform capability after ClassFileLoadHook has been enabled
361 get_prohibited_capabilities()->can_retransform_classes = 1;
362 }
363 }
364 }
365
366
367 void
368 JvmtiEnvBase::record_class_file_load_hook_enabled() {
369 if (!_class_file_load_hook_ever_enabled) {
370 if (Threads::number_of_threads() == 0) {
371 record_first_time_class_file_load_hook_enabled();
372 } else {
373 MutexLocker mu(JvmtiThreadState_lock);
374 record_first_time_class_file_load_hook_enabled();
375 }
376 }
377 }
378
379
380 jvmtiError
381 JvmtiEnvBase::set_native_method_prefixes(jint prefix_count, char** prefixes) {
382 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(),
383 "sanity check");
384
385 int old_prefix_count = get_native_method_prefix_count();
386 char **old_prefixes = get_native_method_prefixes();
387
388 // allocate and install the new prefixex
389 if (prefix_count == 0 || !is_valid()) {
390 _native_method_prefix_count = 0;
391 _native_method_prefixes = NULL;
392 } else {
393 // there are prefixes, allocate an array to hold them, and fill it
394 char** new_prefixes = (char**)os::malloc((prefix_count) * sizeof(char*), mtInternal);
395 if (new_prefixes == NULL) {
396 return JVMTI_ERROR_OUT_OF_MEMORY;
397 }
398 for (int i = 0; i < prefix_count; i++) {
399 char* prefix = prefixes[i];
400 if (prefix == NULL) {
401 for (int j = 0; j < (i-1); j++) {
402 os::free(new_prefixes[j]);
403 }
404 os::free(new_prefixes);
405 return JVMTI_ERROR_NULL_POINTER;
406 }
407 prefix = os::strdup(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_OUT_OF_MEMORY;
414 }
415 new_prefixes[i] = prefix;
416 }
417 _native_method_prefix_count = prefix_count;
418 _native_method_prefixes = new_prefixes;
419 }
420
421 // now that we know the new prefixes have been successfully installed we can
422 // safely remove the old ones
423 if (old_prefix_count != 0) {
424 for (int i = 0; i < old_prefix_count; i++) {
425 os::free(old_prefixes[i]);
426 }
427 os::free(old_prefixes);
428 }
429
430 return JVMTI_ERROR_NONE;
431 }
432
433
434 // Collect all the prefixes which have been set in any JVM TI environments
435 // by the SetNativeMethodPrefix(es) functions. Be sure to maintain the
436 // order of environments and the order of prefixes within each environment.
437 // Return in a resource allocated array.
438 char**
439 JvmtiEnvBase::get_all_native_method_prefixes(int* count_ptr) {
440 assert(Threads::number_of_threads() == 0 ||
441 SafepointSynchronize::is_at_safepoint() ||
442 JvmtiThreadState_lock->is_locked(),
443 "sanity check");
444
445 int total_count = 0;
446 GrowableArray<char*>* prefix_array =new GrowableArray<char*>(5);
447
448 JvmtiEnvIterator it;
449 for (JvmtiEnvBase* env = it.first(); env != NULL; env = it.next(env)) {
450 int prefix_count = env->get_native_method_prefix_count();
451 char** prefixes = env->get_native_method_prefixes();
452 for (int j = 0; j < prefix_count; j++) {
453 // retrieve a prefix and so that it is safe against asynchronous changes
454 // copy it into the resource area
455 char* prefix = prefixes[j];
456 char* prefix_copy = NEW_RESOURCE_ARRAY(char, strlen(prefix)+1);
457 strcpy(prefix_copy, prefix);
458 prefix_array->at_put_grow(total_count++, prefix_copy);
459 }
460 }
461
462 char** all_prefixes = NEW_RESOURCE_ARRAY(char*, total_count);
463 char** p = all_prefixes;
464 for (int i = 0; i < total_count; ++i) {
465 *p++ = prefix_array->at(i);
466 }
467 *count_ptr = total_count;
468 return all_prefixes;
469 }
470
471 void
472 JvmtiEnvBase::set_event_callbacks(const jvmtiEventCallbacks* callbacks,
473 jint size_of_callbacks) {
474 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
475
476 size_t byte_cnt = sizeof(jvmtiEventCallbacks);
477
478 // clear in either case to be sure we got any gap between sizes
479 memset(&_event_callbacks, 0, byte_cnt);
480
481 // Now that JvmtiThreadState_lock is held, prevent a possible race condition where events
482 // are re-enabled by a call to set event callbacks where the DisposeEnvironment
483 // occurs after the boiler-plate environment check and before the lock is acquired.
484 if (callbacks != NULL && is_valid()) {
485 if (size_of_callbacks < (jint)byte_cnt) {
486 byte_cnt = size_of_callbacks;
487 }
488 memcpy(&_event_callbacks, callbacks, byte_cnt);
489 }
490 }
491
492
493 // In the fullness of time, all users of the method should instead
494 // directly use allocate, besides being cleaner and faster, this will
495 // mean much better out of memory handling
496 unsigned char *
497 JvmtiEnvBase::jvmtiMalloc(jlong size) {
498 unsigned char* mem = NULL;
499 jvmtiError result = allocate(size, &mem);
500 assert(result == JVMTI_ERROR_NONE, "Allocate failed");
501 return mem;
502 }
503
504
505 // Handle management
506
507 jobject JvmtiEnvBase::jni_reference(Handle hndl) {
508 return JNIHandles::make_local(hndl());
509 }
510
511 jobject JvmtiEnvBase::jni_reference(JavaThread *thread, Handle hndl) {
512 return JNIHandles::make_local(thread, hndl());
513 }
514
515 void JvmtiEnvBase::destroy_jni_reference(jobject jobj) {
516 JNIHandles::destroy_local(jobj);
517 }
518
519 void JvmtiEnvBase::destroy_jni_reference(JavaThread *thread, jobject jobj) {
520 JNIHandles::destroy_local(jobj); // thread is unused.
521 }
522
523 //
524 // Threads
525 //
526
527 jobject *
528 JvmtiEnvBase::new_jobjectArray(int length, Handle *handles) {
529 if (length == 0) {
530 return NULL;
531 }
532
533 jobject *objArray = (jobject *) jvmtiMalloc(sizeof(jobject) * length);
534 NULL_CHECK(objArray, NULL);
535
536 for (int i=0; i<length; i++) {
537 objArray[i] = jni_reference(handles[i]);
538 }
539 return objArray;
540 }
541
542 jthread *
543 JvmtiEnvBase::new_jthreadArray(int length, Handle *handles) {
544 return (jthread *) new_jobjectArray(length,handles);
545 }
546
547 jthreadGroup *
548 JvmtiEnvBase::new_jthreadGroupArray(int length, Handle *handles) {
549 return (jthreadGroup *) new_jobjectArray(length,handles);
550 }
551
552 // return the vframe on the specified thread and depth, NULL if no such frame
553 vframe*
554 JvmtiEnvBase::vframeFor(JavaThread* java_thread, jint depth) {
555 if (!java_thread->has_last_Java_frame()) {
556 return NULL;
557 }
558 RegisterMap reg_map(java_thread);
559 vframe *vf = java_thread->last_java_vframe(®_map);
560 int d = 0;
561 while ((vf != NULL) && (d < depth)) {
562 vf = vf->java_sender();
563 d++;
564 }
565 return vf;
566 }
567
568
569 //
570 // utilities: JNI objects
571 //
572
573
574 jclass
575 JvmtiEnvBase::get_jni_class_non_null(Klass* k) {
576 assert(k != NULL, "k != NULL");
577 Thread *thread = Thread::current();
578 return (jclass)jni_reference(Handle(thread, k->java_mirror()));
579 }
580
581 //
582 // Field Information
583 //
584
585 bool
586 JvmtiEnvBase::get_field_descriptor(Klass* k, jfieldID field, fieldDescriptor* fd) {
587 if (!jfieldIDWorkaround::is_valid_jfieldID(k, field)) {
588 return false;
589 }
590 bool found = false;
591 if (jfieldIDWorkaround::is_static_jfieldID(field)) {
592 JNIid* id = jfieldIDWorkaround::from_static_jfieldID(field);
593 found = id->find_local_field(fd);
594 } else {
595 // Non-static field. The fieldID is really the offset of the field within the object.
596 int offset = jfieldIDWorkaround::from_instance_jfieldID(k, field);
597 found = InstanceKlass::cast(k)->find_field_from_offset(offset, false, fd);
598 }
599 return found;
600 }
601
602 //
603 // Object Monitor Information
604 //
605
606 //
607 // Count the number of objects for a lightweight monitor. The hobj
608 // parameter is object that owns the monitor so this routine will
609 // count the number of times the same object was locked by frames
610 // in java_thread.
611 //
612 jint
613 JvmtiEnvBase::count_locked_objects(JavaThread *java_thread, Handle hobj) {
614 jint ret = 0;
615 if (!java_thread->has_last_Java_frame()) {
616 return ret; // no Java frames so no monitors
617 }
618
619 ResourceMark rm;
620 HandleMark hm;
621 RegisterMap reg_map(java_thread);
622
623 for(javaVFrame *jvf=java_thread->last_java_vframe(®_map); jvf != NULL;
624 jvf = jvf->java_sender()) {
625 GrowableArray<MonitorInfo*>* mons = jvf->monitors();
626 if (!mons->is_empty()) {
627 for (int i = 0; i < mons->length(); i++) {
628 MonitorInfo *mi = mons->at(i);
629 if (mi->owner_is_scalar_replaced()) continue;
630
631 // see if owner of the monitor is our object
632 if (mi->owner() != NULL && mi->owner() == hobj()) {
633 ret++;
634 }
635 }
636 }
637 }
638 return ret;
639 }
640
641
642
643 jvmtiError
644 JvmtiEnvBase::get_current_contended_monitor(JavaThread *calling_thread, JavaThread *java_thread, jobject *monitor_ptr) {
645 #ifdef ASSERT
646 uint32_t debug_bits = 0;
647 #endif
648 assert((SafepointSynchronize::is_at_safepoint() ||
649 java_thread->is_thread_fully_suspended(false, &debug_bits)),
650 "at safepoint or target thread is suspended");
651 oop obj = NULL;
652 ObjectMonitor *mon = java_thread->current_waiting_monitor();
653 if (mon == NULL) {
654 // thread is not doing an Object.wait() call
655 mon = java_thread->current_pending_monitor();
656 if (mon != NULL) {
657 // The thread is trying to enter() or raw_enter() an ObjectMonitor.
658 obj = (oop)mon->object();
659 // If obj == NULL, then ObjectMonitor is raw which doesn't count
660 // as contended for this API
661 }
662 // implied else: no contended ObjectMonitor
663 } else {
664 // thread is doing an Object.wait() call
665 obj = (oop)mon->object();
666 assert(obj != NULL, "Object.wait() should have an object");
667 }
668
669 if (obj == NULL) {
670 *monitor_ptr = NULL;
671 } else {
672 HandleMark hm;
673 Handle hobj(Thread::current(), obj);
674 *monitor_ptr = jni_reference(calling_thread, hobj);
675 }
676 return JVMTI_ERROR_NONE;
677 }
678
679
680 jvmtiError
681 JvmtiEnvBase::get_owned_monitors(JavaThread *calling_thread, JavaThread* java_thread,
682 GrowableArray<jvmtiMonitorStackDepthInfo*> *owned_monitors_list) {
683 jvmtiError err = JVMTI_ERROR_NONE;
684 #ifdef ASSERT
685 uint32_t debug_bits = 0;
686 #endif
687 assert((SafepointSynchronize::is_at_safepoint() ||
688 java_thread->is_thread_fully_suspended(false, &debug_bits)),
689 "at safepoint or target thread is suspended");
690
691 if (java_thread->has_last_Java_frame()) {
692 ResourceMark rm;
693 HandleMark hm;
694 RegisterMap reg_map(java_thread);
695
696 int depth = 0;
697 for (javaVFrame *jvf = java_thread->last_java_vframe(®_map); jvf != NULL;
698 jvf = jvf->java_sender()) {
699 if (MaxJavaStackTraceDepth == 0 || depth++ < MaxJavaStackTraceDepth) { // check for stack too deep
700 // add locked objects for this frame into list
701 err = get_locked_objects_in_frame(calling_thread, java_thread, jvf, owned_monitors_list, depth-1);
702 if (err != JVMTI_ERROR_NONE) {
703 return err;
704 }
705 }
706 }
707 }
708
709 // Get off stack monitors. (e.g. acquired via jni MonitorEnter).
710 JvmtiMonitorClosure jmc(java_thread, calling_thread, owned_monitors_list, this);
711 ObjectSynchronizer::monitors_iterate(&jmc);
712 err = jmc.error();
713
714 return err;
715 }
716
717 // Save JNI local handles for any objects that this frame owns.
718 jvmtiError
719 JvmtiEnvBase::get_locked_objects_in_frame(JavaThread* calling_thread, JavaThread* java_thread,
720 javaVFrame *jvf, GrowableArray<jvmtiMonitorStackDepthInfo*>* owned_monitors_list, jint stack_depth) {
721 jvmtiError err = JVMTI_ERROR_NONE;
722 ResourceMark rm;
723
724 GrowableArray<MonitorInfo*>* mons = jvf->monitors();
725 if (mons->is_empty()) {
726 return err; // this javaVFrame holds no monitors
727 }
728
729 HandleMark hm;
730 oop wait_obj = NULL;
731 {
732 // save object of current wait() call (if any) for later comparison
733 ObjectMonitor *mon = java_thread->current_waiting_monitor();
734 if (mon != NULL) {
735 wait_obj = (oop)mon->object();
736 }
737 }
738 oop pending_obj = NULL;
739 {
740 // save object of current enter() call (if any) for later comparison
741 ObjectMonitor *mon = java_thread->current_pending_monitor();
742 if (mon != NULL) {
743 pending_obj = (oop)mon->object();
744 }
745 }
746
747 for (int i = 0; i < mons->length(); i++) {
748 MonitorInfo *mi = mons->at(i);
749
750 if (mi->owner_is_scalar_replaced()) continue;
751
752 oop obj = mi->owner();
753 if (obj == NULL) {
754 // this monitor doesn't have an owning object so skip it
755 continue;
756 }
757
758 if (wait_obj == obj) {
759 // the thread is waiting on this monitor so it isn't really owned
760 continue;
761 }
762
763 if (pending_obj == obj) {
764 // the thread is pending on this monitor so it isn't really owned
765 continue;
766 }
767
768 if (owned_monitors_list->length() > 0) {
769 // Our list has at least one object on it so we have to check
770 // for recursive object locking
771 bool found = false;
772 for (int j = 0; j < owned_monitors_list->length(); j++) {
773 jobject jobj = ((jvmtiMonitorStackDepthInfo*)owned_monitors_list->at(j))->monitor;
774 oop check = JNIHandles::resolve(jobj);
775 if (check == obj) {
776 found = true; // we found the object
777 break;
778 }
779 }
780
781 if (found) {
782 // already have this object so don't include it
783 continue;
784 }
785 }
786
787 // add the owning object to our list
788 jvmtiMonitorStackDepthInfo *jmsdi;
789 err = allocate(sizeof(jvmtiMonitorStackDepthInfo), (unsigned char **)&jmsdi);
790 if (err != JVMTI_ERROR_NONE) {
791 return err;
792 }
793 Handle hobj(Thread::current(), obj);
794 jmsdi->monitor = jni_reference(calling_thread, hobj);
795 jmsdi->stack_depth = stack_depth;
796 owned_monitors_list->append(jmsdi);
797 }
798
799 return err;
800 }
801
802 jvmtiError
803 JvmtiEnvBase::get_stack_trace(JavaThread *java_thread,
804 jint start_depth, jint max_count,
805 jvmtiFrameInfo* frame_buffer, jint* count_ptr) {
806 #ifdef ASSERT
807 uint32_t debug_bits = 0;
808 #endif
809 assert((SafepointSynchronize::is_at_safepoint() ||
810 java_thread->is_thread_fully_suspended(false, &debug_bits)),
811 "at safepoint or target thread is suspended");
812 int count = 0;
813 if (java_thread->has_last_Java_frame()) {
814 RegisterMap reg_map(java_thread);
815 Thread* current_thread = Thread::current();
816 ResourceMark rm(current_thread);
817 javaVFrame *jvf = java_thread->last_java_vframe(®_map);
818 HandleMark hm(current_thread);
819 if (start_depth != 0) {
820 if (start_depth > 0) {
821 for (int j = 0; j < start_depth && jvf != NULL; j++) {
822 jvf = jvf->java_sender();
823 }
824 if (jvf == NULL) {
825 // start_depth is deeper than the stack depth
826 return JVMTI_ERROR_ILLEGAL_ARGUMENT;
827 }
828 } else { // start_depth < 0
829 // we are referencing the starting depth based on the oldest
830 // part of the stack.
831 // optimize to limit the number of times that java_sender() is called
832 javaVFrame *jvf_cursor = jvf;
833 javaVFrame *jvf_prev = NULL;
834 javaVFrame *jvf_prev_prev = NULL;
835 int j = 0;
836 while (jvf_cursor != NULL) {
837 jvf_prev_prev = jvf_prev;
838 jvf_prev = jvf_cursor;
839 for (j = 0; j > start_depth && jvf_cursor != NULL; j--) {
840 jvf_cursor = jvf_cursor->java_sender();
841 }
842 }
843 if (j == start_depth) {
844 // previous pointer is exactly where we want to start
845 jvf = jvf_prev;
846 } else {
847 // we need to back up further to get to the right place
848 if (jvf_prev_prev == NULL) {
849 // the -start_depth is greater than the stack depth
850 return JVMTI_ERROR_ILLEGAL_ARGUMENT;
851 }
852 // j now is the number of frames on the stack starting with
853 // jvf_prev, we start from jvf_prev_prev and move older on
854 // the stack that many, the result is -start_depth frames
855 // remaining.
856 jvf = jvf_prev_prev;
857 for (; j < 0; j++) {
858 jvf = jvf->java_sender();
859 }
860 }
861 }
862 }
863 for (; count < max_count && jvf != NULL; count++) {
864 frame_buffer[count].method = jvf->method()->jmethod_id();
865 frame_buffer[count].location = (jvf->method()->is_native() ? -1 : jvf->bci());
866 jvf = jvf->java_sender();
867 }
868 } else {
869 if (start_depth != 0) {
870 // no frames and there is a starting depth
871 return JVMTI_ERROR_ILLEGAL_ARGUMENT;
872 }
873 }
874 *count_ptr = count;
875 return JVMTI_ERROR_NONE;
876 }
877
878 jvmtiError
879 JvmtiEnvBase::get_frame_count(JvmtiThreadState *state, jint *count_ptr) {
880 assert((state != NULL),
881 "JavaThread should create JvmtiThreadState before calling this method");
882 *count_ptr = state->count_frames();
883 return JVMTI_ERROR_NONE;
884 }
885
886 jvmtiError
887 JvmtiEnvBase::get_frame_location(JavaThread *java_thread, jint depth,
888 jmethodID* method_ptr, jlocation* location_ptr) {
889 #ifdef ASSERT
890 uint32_t debug_bits = 0;
891 #endif
892 assert((SafepointSynchronize::is_at_safepoint() ||
893 java_thread->is_thread_fully_suspended(false, &debug_bits)),
894 "at safepoint or target thread is suspended");
895 Thread* current_thread = Thread::current();
896 ResourceMark rm(current_thread);
897
898 vframe *vf = vframeFor(java_thread, depth);
899 if (vf == NULL) {
900 return JVMTI_ERROR_NO_MORE_FRAMES;
901 }
902
903 // vframeFor should return a java frame. If it doesn't
904 // it means we've got an internal error and we return the
905 // error in product mode. In debug mode we will instead
906 // attempt to cast the vframe to a javaVFrame and will
907 // cause an assertion/crash to allow further diagnosis.
908 #ifdef PRODUCT
909 if (!vf->is_java_frame()) {
910 return JVMTI_ERROR_INTERNAL;
911 }
912 #endif
913
914 HandleMark hm(current_thread);
915 javaVFrame *jvf = javaVFrame::cast(vf);
916 Method* method = jvf->method();
917 if (method->is_native()) {
918 *location_ptr = -1;
919 } else {
920 *location_ptr = jvf->bci();
921 }
922 *method_ptr = method->jmethod_id();
923
924 return JVMTI_ERROR_NONE;
925 }
926
927
928 jvmtiError
929 JvmtiEnvBase::get_object_monitor_usage(JavaThread* calling_thread, jobject object, jvmtiMonitorUsage* info_ptr) {
930 HandleMark hm;
931 Handle hobj;
932
933 Thread* current_thread = Thread::current();
934 bool at_safepoint = SafepointSynchronize::is_at_safepoint();
935
936 // Check arguments
937 {
938 oop mirror = JNIHandles::resolve_external_guard(object);
939 NULL_CHECK(mirror, JVMTI_ERROR_INVALID_OBJECT);
940 NULL_CHECK(info_ptr, JVMTI_ERROR_NULL_POINTER);
941
942 hobj = Handle(current_thread, mirror);
943 }
944
945 JavaThread *owning_thread = NULL;
946 ObjectMonitor *mon = NULL;
947 jvmtiMonitorUsage ret = {
948 NULL, 0, 0, NULL, 0, NULL
949 };
950
951 uint32_t debug_bits = 0;
952 // first derive the object's owner and entry_count (if any)
953 {
954 // Revoke any biases before querying the mark word
955 if (at_safepoint) {
956 BiasedLocking::revoke_at_safepoint(hobj);
957 } else {
958 BiasedLocking::revoke_and_rebias(hobj, false, calling_thread);
959 }
960
961 address owner = NULL;
962 {
963 markOop mark = hobj()->mark();
964
965 if (!mark->has_monitor()) {
966 // this object has a lightweight monitor
967
968 if (mark->has_locker()) {
969 owner = (address)mark->locker(); // save the address of the Lock word
970 }
971 // implied else: no owner
972 } else {
973 // this object has a heavyweight monitor
974 mon = mark->monitor();
975
976 // The owner field of a heavyweight monitor may be NULL for no
977 // owner, a JavaThread * or it may still be the address of the
978 // Lock word in a JavaThread's stack. A monitor can be inflated
979 // by a non-owning JavaThread, but only the owning JavaThread
980 // can change the owner field from the Lock word to the
981 // JavaThread * and it may not have done that yet.
982 owner = (address)mon->owner();
983 }
984 }
985
986 if (owner != NULL) {
987 // Use current thread since function can be called from a
988 // JavaThread or the VMThread.
989 ThreadsListHandle tlh;
990 // This monitor is owned so we have to find the owning JavaThread.
991 owning_thread = Threads::owning_thread_from_monitor_owner(tlh.list(), owner);
992 // Cannot assume (owning_thread != NULL) here because this function
993 // may not have been called at a safepoint and the owning_thread
994 // might not be suspended.
995 if (owning_thread != NULL) {
996 // The monitor's owner either has to be the current thread, at safepoint
997 // or it has to be suspended. Any of these conditions will prevent both
998 // contending and waiting threads from modifying the state of
999 // the monitor.
1000 if (!at_safepoint && !owning_thread->is_thread_fully_suspended(true, &debug_bits)) {
1001 // Don't worry! This return of JVMTI_ERROR_THREAD_NOT_SUSPENDED
1002 // will not make it back to the JVM/TI agent. The error code will
1003 // get intercepted in JvmtiEnv::GetObjectMonitorUsage() which
1004 // will retry the call via a VM_GetObjectMonitorUsage VM op.
1005 return JVMTI_ERROR_THREAD_NOT_SUSPENDED;
1006 }
1007 HandleMark hm;
1008 Handle th(current_thread, owning_thread->threadObj());
1009 ret.owner = (jthread)jni_reference(calling_thread, th);
1010 }
1011 // implied else: no owner
1012 } // ThreadsListHandle is destroyed here.
1013
1014 if (owning_thread != NULL) { // monitor is owned
1015 // The recursions field of a monitor does not reflect recursions
1016 // as lightweight locks before inflating the monitor are not included.
1017 // We have to count the number of recursive monitor entries the hard way.
1018 // We pass a handle to survive any GCs along the way.
1019 ResourceMark rm;
1020 ret.entry_count = count_locked_objects(owning_thread, hobj);
1021 }
1022 // implied else: entry_count == 0
1023 }
1024
1025 jint nWant = 0, nWait = 0;
1026 if (mon != NULL) {
1027 // this object has a heavyweight monitor
1028 nWant = mon->contentions(); // # of threads contending for monitor
1029 nWait = mon->waiters(); // # of threads in Object.wait()
1030 ret.waiter_count = nWant + nWait;
1031 ret.notify_waiter_count = nWait;
1032 } else {
1033 // this object has a lightweight monitor
1034 ret.waiter_count = 0;
1035 ret.notify_waiter_count = 0;
1036 }
1037
1038 // Allocate memory for heavyweight and lightweight monitor.
1039 jvmtiError err;
1040 err = allocate(ret.waiter_count * sizeof(jthread *), (unsigned char**)&ret.waiters);
1041 if (err != JVMTI_ERROR_NONE) {
1042 return err;
1043 }
1044 err = allocate(ret.notify_waiter_count * sizeof(jthread *),
1045 (unsigned char**)&ret.notify_waiters);
1046 if (err != JVMTI_ERROR_NONE) {
1047 deallocate((unsigned char*)ret.waiters);
1048 return err;
1049 }
1050
1051 // now derive the rest of the fields
1052 if (mon != NULL) {
1053 // this object has a heavyweight monitor
1054
1055 // Number of waiters may actually be less than the waiter count.
1056 // So NULL out memory so that unused memory will be NULL.
1057 memset(ret.waiters, 0, ret.waiter_count * sizeof(jthread *));
1058 memset(ret.notify_waiters, 0, ret.notify_waiter_count * sizeof(jthread *));
1059
1060 if (ret.waiter_count > 0) {
1061 // we have contending and/or waiting threads
1062 HandleMark hm;
1063 // Use current thread since function can be called from a
1064 // JavaThread or the VMThread.
1065 ThreadsListHandle tlh;
1066 if (nWant > 0) {
1067 // we have contending threads
1068 ResourceMark rm;
1069 // get_pending_threads returns only java thread so we do not need to
1070 // check for non java threads.
1071 GrowableArray<JavaThread*>* wantList = Threads::get_pending_threads(tlh.list(), nWant, (address)mon);
1072 if (wantList->length() < nWant) {
1073 // robustness: the pending list has gotten smaller
1074 nWant = wantList->length();
1075 }
1076 for (int i = 0; i < nWant; i++) {
1077 JavaThread *pending_thread = wantList->at(i);
1078 // If the monitor has no owner, then a non-suspended contending
1079 // thread could potentially change the state of the monitor by
1080 // entering it. The JVM/TI spec doesn't allow this.
1081 if (owning_thread == NULL && !at_safepoint &
1082 !pending_thread->is_thread_fully_suspended(true, &debug_bits)) {
1083 if (ret.owner != NULL) {
1084 destroy_jni_reference(calling_thread, ret.owner);
1085 }
1086 for (int j = 0; j < i; j++) {
1087 destroy_jni_reference(calling_thread, ret.waiters[j]);
1088 }
1089 deallocate((unsigned char*)ret.waiters);
1090 deallocate((unsigned char*)ret.notify_waiters);
1091 return JVMTI_ERROR_THREAD_NOT_SUSPENDED;
1092 }
1093 Handle th(current_thread, pending_thread->threadObj());
1094 ret.waiters[i] = (jthread)jni_reference(calling_thread, th);
1095 }
1096 }
1097 if (nWait > 0) {
1098 // we have threads in Object.wait()
1099 int offset = nWant; // add after any contending threads
1100 ObjectWaiter *waiter = mon->first_waiter();
1101 for (int i = 0, j = 0; i < nWait; i++) {
1102 if (waiter == NULL) {
1103 // robustness: the waiting list has gotten smaller
1104 nWait = j;
1105 break;
1106 }
1107 Thread *t = mon->thread_of_waiter(waiter);
1108 if (t != NULL && t->is_Java_thread()) {
1109 JavaThread *wjava_thread = (JavaThread *)t;
1110 // If the thread was found on the ObjectWaiter list, then
1111 // it has not been notified. This thread can't change the
1112 // state of the monitor so it doesn't need to be suspended.
1113 Handle th(current_thread, wjava_thread->threadObj());
1114 ret.waiters[offset + j] = (jthread)jni_reference(calling_thread, th);
1115 ret.notify_waiters[j++] = (jthread)jni_reference(calling_thread, th);
1116 }
1117 waiter = mon->next_waiter(waiter);
1118 }
1119 }
1120 } // ThreadsListHandle is destroyed here.
1121
1122 // Adjust count. nWant and nWait count values may be less than original.
1123 ret.waiter_count = nWant + nWait;
1124 ret.notify_waiter_count = nWait;
1125 } else {
1126 // this object has a lightweight monitor and we have nothing more
1127 // to do here because the defaults are just fine.
1128 }
1129
1130 // we don't update return parameter unless everything worked
1131 *info_ptr = ret;
1132
1133 return JVMTI_ERROR_NONE;
1134 }
1135
1136 ResourceTracker::ResourceTracker(JvmtiEnv* env) {
1137 _env = env;
1138 _allocations = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<unsigned char*>(20, true);
1139 _failed = false;
1140 }
1141 ResourceTracker::~ResourceTracker() {
1142 if (_failed) {
1143 for (int i=0; i<_allocations->length(); i++) {
1144 _env->deallocate(_allocations->at(i));
1145 }
1146 }
1147 delete _allocations;
1148 }
1149
1150 jvmtiError ResourceTracker::allocate(jlong size, unsigned char** mem_ptr) {
1151 unsigned char *ptr;
1152 jvmtiError err = _env->allocate(size, &ptr);
1153 if (err == JVMTI_ERROR_NONE) {
1154 _allocations->append(ptr);
1155 *mem_ptr = ptr;
1156 } else {
1157 *mem_ptr = NULL;
1158 _failed = true;
1159 }
1160 return err;
1161 }
1162
1163 unsigned char* ResourceTracker::allocate(jlong size) {
1164 unsigned char* ptr;
1165 allocate(size, &ptr);
1166 return ptr;
1167 }
1168
1169 char* ResourceTracker::strdup(const char* str) {
1170 char *dup_str = (char*)allocate(strlen(str)+1);
1171 if (dup_str != NULL) {
1172 strcpy(dup_str, str);
1173 }
1174 return dup_str;
1175 }
1176
1177 struct StackInfoNode {
1178 struct StackInfoNode *next;
1179 jvmtiStackInfo info;
1180 };
1181
1182 // Create a jvmtiStackInfo inside a linked list node and create a
1183 // buffer for the frame information, both allocated as resource objects.
1184 // Fill in both the jvmtiStackInfo and the jvmtiFrameInfo.
1185 // Note that either or both of thr and thread_oop
1186 // may be null if the thread is new or has exited.
1187 void
1188 VM_GetMultipleStackTraces::fill_frames(jthread jt, JavaThread *thr, oop thread_oop) {
1189 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
1190
1191 jint state = 0;
1192 struct StackInfoNode *node = NEW_RESOURCE_OBJ(struct StackInfoNode);
1193 jvmtiStackInfo *infop = &(node->info);
1194 node->next = head();
1195 set_head(node);
1196 infop->frame_count = 0;
1197 infop->thread = jt;
1198
1199 if (thread_oop != NULL) {
1200 // get most state bits
1201 state = (jint)java_lang_Thread::get_thread_status(thread_oop);
1202 }
1203
1204 if (thr != NULL) { // add more state bits if there is a JavaThead to query
1205 // same as is_being_ext_suspended() but without locking
1206 if (thr->is_ext_suspended() || thr->is_external_suspend()) {
1207 state |= JVMTI_THREAD_STATE_SUSPENDED;
1208 }
1209 JavaThreadState jts = thr->thread_state();
1210 if (jts == _thread_in_native) {
1211 state |= JVMTI_THREAD_STATE_IN_NATIVE;
1212 }
1213 OSThread* osThread = thr->osthread();
1214 if (osThread != NULL && osThread->interrupted()) {
1215 state |= JVMTI_THREAD_STATE_INTERRUPTED;
1216 }
1217 }
1218 infop->state = state;
1219
1220 if (thr != NULL || (state & JVMTI_THREAD_STATE_ALIVE) != 0) {
1221 infop->frame_buffer = NEW_RESOURCE_ARRAY(jvmtiFrameInfo, max_frame_count());
1222 env()->get_stack_trace(thr, 0, max_frame_count(),
1223 infop->frame_buffer, &(infop->frame_count));
1224 } else {
1225 infop->frame_buffer = NULL;
1226 infop->frame_count = 0;
1227 }
1228 _frame_count_total += infop->frame_count;
1229 }
1230
1231 // Based on the stack information in the linked list, allocate memory
1232 // block to return and fill it from the info in the linked list.
1233 void
1234 VM_GetMultipleStackTraces::allocate_and_fill_stacks(jint thread_count) {
1235 // do I need to worry about alignment issues?
1236 jlong alloc_size = thread_count * sizeof(jvmtiStackInfo)
1237 + _frame_count_total * sizeof(jvmtiFrameInfo);
1238 env()->allocate(alloc_size, (unsigned char **)&_stack_info);
1239
1240 // pointers to move through the newly allocated space as it is filled in
1241 jvmtiStackInfo *si = _stack_info + thread_count; // bottom of stack info
1242 jvmtiFrameInfo *fi = (jvmtiFrameInfo *)si; // is the top of frame info
1243
1244 // copy information in resource area into allocated buffer
1245 // insert stack info backwards since linked list is backwards
1246 // insert frame info forwards
1247 // walk the StackInfoNodes
1248 for (struct StackInfoNode *sin = head(); sin != NULL; sin = sin->next) {
1249 jint frame_count = sin->info.frame_count;
1250 size_t frames_size = frame_count * sizeof(jvmtiFrameInfo);
1251 --si;
1252 memcpy(si, &(sin->info), sizeof(jvmtiStackInfo));
1253 if (frames_size == 0) {
1254 si->frame_buffer = NULL;
1255 } else {
1256 memcpy(fi, sin->info.frame_buffer, frames_size);
1257 si->frame_buffer = fi; // point to the new allocated copy of the frames
1258 fi += frame_count;
1259 }
1260 }
1261 assert(si == _stack_info, "the last copied stack info must be the first record");
1262 assert((unsigned char *)fi == ((unsigned char *)_stack_info) + alloc_size,
1263 "the last copied frame info must be the last record");
1264 }
1265
1266
1267 void
1268 VM_GetThreadListStackTraces::doit() {
1269 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
1270
1271 ResourceMark rm;
1272 ThreadsListHandle tlh;
1273 for (int i = 0; i < _thread_count; ++i) {
1274 jthread jt = _thread_list[i];
1275 JavaThread* java_thread = NULL;
1276 oop thread_oop = NULL;
1277 jvmtiError err = JvmtiExport::cv_external_thread_to_JavaThread(tlh.list(), jt, &java_thread, &thread_oop);
1278 if (err != JVMTI_ERROR_NONE) {
1279 // We got an error code so we don't have a JavaThread *, but
1280 // only return an error from here if we didn't get a valid
1281 // thread_oop.
1282 if (thread_oop == NULL) {
1283 set_result(err);
1284 return;
1285 }
1286 // We have a valid thread_oop.
1287 }
1288 fill_frames(jt, java_thread, thread_oop);
1289 }
1290 allocate_and_fill_stacks(_thread_count);
1291 }
1292
1293 void
1294 VM_GetAllStackTraces::doit() {
1295 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
1296
1297 ResourceMark rm;
1298 _final_thread_count = 0;
1299 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *jt = jtiwh.next(); ) {
1300 oop thread_oop = jt->threadObj();
1301 if (thread_oop != NULL &&
1302 !jt->is_exiting() &&
1303 java_lang_Thread::is_alive(thread_oop) &&
1304 !jt->is_hidden_from_external_view()) {
1305 ++_final_thread_count;
1306 // Handle block of the calling thread is used to create local refs.
1307 fill_frames((jthread)JNIHandles::make_local(_calling_thread, thread_oop),
1308 jt, thread_oop);
1309 }
1310 }
1311 allocate_and_fill_stacks(_final_thread_count);
1312 }
1313
1314 // Verifies that the top frame is a java frame in an expected state.
1315 // Deoptimizes frame if needed.
1316 // Checks that the frame method signature matches the return type (tos).
1317 // HandleMark must be defined in the caller only.
1318 // It is to keep a ret_ob_h handle alive after return to the caller.
1319 jvmtiError
1320 JvmtiEnvBase::check_top_frame(JavaThread* current_thread, JavaThread* java_thread,
1321 jvalue value, TosState tos, Handle* ret_ob_h) {
1322 ResourceMark rm(current_thread);
1323
1324 vframe *vf = vframeFor(java_thread, 0);
1325 NULL_CHECK(vf, JVMTI_ERROR_NO_MORE_FRAMES);
1326
1327 javaVFrame *jvf = (javaVFrame*) vf;
1328 if (!vf->is_java_frame() || jvf->method()->is_native()) {
1329 return JVMTI_ERROR_OPAQUE_FRAME;
1330 }
1331
1332 // If the frame is a compiled one, need to deoptimize it.
1333 if (vf->is_compiled_frame()) {
1334 if (!vf->fr().can_be_deoptimized()) {
1335 return JVMTI_ERROR_OPAQUE_FRAME;
1336 }
1337 Deoptimization::deoptimize_frame(java_thread, jvf->fr().id());
1338 }
1339
1340 // Get information about method return type
1341 Symbol* signature = jvf->method()->signature();
1342
1343 ResultTypeFinder rtf(signature);
1344 TosState fr_tos = as_TosState(rtf.type());
1345 if (fr_tos != tos) {
1346 if (tos != itos || (fr_tos != btos && fr_tos != ztos && fr_tos != ctos && fr_tos != stos)) {
1347 return JVMTI_ERROR_TYPE_MISMATCH;
1348 }
1349 }
1350
1351 // Check that the jobject class matches the return type signature.
1352 jobject jobj = value.l;
1353 if (tos == atos && jobj != NULL) { // NULL reference is allowed
1354 Handle ob_h(current_thread, JNIHandles::resolve_external_guard(jobj));
1355 NULL_CHECK(ob_h, JVMTI_ERROR_INVALID_OBJECT);
1356 Klass* ob_k = ob_h()->klass();
1357 NULL_CHECK(ob_k, JVMTI_ERROR_INVALID_OBJECT);
1358
1359 // Method return type signature.
1360 char* ty_sign = 1 + strchr(signature->as_C_string(), ')');
1361
1362 if (!VM_GetOrSetLocal::is_assignable(ty_sign, ob_k, current_thread)) {
1363 return JVMTI_ERROR_TYPE_MISMATCH;
1364 }
1365 *ret_ob_h = ob_h;
1366 }
1367 return JVMTI_ERROR_NONE;
1368 } /* end check_top_frame */
1369
1370
1371 // ForceEarlyReturn<type> follows the PopFrame approach in many aspects.
1372 // Main difference is on the last stage in the interpreter.
1373 // The PopFrame stops method execution to continue execution
1374 // from the same method call instruction.
1375 // The ForceEarlyReturn forces return from method so the execution
1376 // continues at the bytecode following the method call.
1377
1378 // Threads_lock NOT held, java_thread not protected by lock
1379 // java_thread - pre-checked
1380
1381 jvmtiError
1382 JvmtiEnvBase::force_early_return(JavaThread* java_thread, jvalue value, TosState tos) {
1383 JavaThread* current_thread = JavaThread::current();
1384 HandleMark hm(current_thread);
1385 uint32_t debug_bits = 0;
1386
1387 // retrieve or create the state
1388 JvmtiThreadState* state = JvmtiThreadState::state_for(java_thread);
1389 if (state == NULL) {
1390 return JVMTI_ERROR_THREAD_NOT_ALIVE;
1391 }
1392
1393 // Check if java_thread is fully suspended
1394 if (!java_thread->is_thread_fully_suspended(true /* wait for suspend completion */, &debug_bits)) {
1395 return JVMTI_ERROR_THREAD_NOT_SUSPENDED;
1396 }
1397
1398 // Check to see if a ForceEarlyReturn was already in progress
1399 if (state->is_earlyret_pending()) {
1400 // Probably possible for JVMTI clients to trigger this, but the
1401 // JPDA backend shouldn't allow this to happen
1402 return JVMTI_ERROR_INTERNAL;
1403 }
1404 {
1405 // The same as for PopFrame. Workaround bug:
1406 // 4812902: popFrame hangs if the method is waiting at a synchronize
1407 // Catch this condition and return an error to avoid hanging.
1408 // Now JVMTI spec allows an implementation to bail out with an opaque
1409 // frame error.
1410 OSThread* osThread = java_thread->osthread();
1411 if (osThread->get_state() == MONITOR_WAIT) {
1412 return JVMTI_ERROR_OPAQUE_FRAME;
1413 }
1414 }
1415 Handle ret_ob_h;
1416 jvmtiError err = check_top_frame(current_thread, java_thread, value, tos, &ret_ob_h);
1417 if (err != JVMTI_ERROR_NONE) {
1418 return err;
1419 }
1420 assert(tos != atos || value.l == NULL || ret_ob_h() != NULL,
1421 "return object oop must not be NULL if jobject is not NULL");
1422
1423 // Update the thread state to reflect that the top frame must be
1424 // forced to return.
1425 // The current frame will be returned later when the suspended
1426 // thread is resumed and right before returning from VM to Java.
1427 // (see call_VM_base() in assembler_<cpu>.cpp).
1428
1429 state->set_earlyret_pending();
1430 state->set_earlyret_oop(ret_ob_h());
1431 state->set_earlyret_value(value, tos);
1432
1433 // Set pending step flag for this early return.
1434 // It is cleared when next step event is posted.
1435 state->set_pending_step_for_earlyret();
1436
1437 return JVMTI_ERROR_NONE;
1438 } /* end force_early_return */
1439
1440 void
1441 JvmtiMonitorClosure::do_monitor(ObjectMonitor* mon) {
1442 if ( _error != JVMTI_ERROR_NONE) {
1443 // Error occurred in previous iteration so no need to add
1444 // to the list.
1445 return;
1446 }
1447 if (mon->owner() == _java_thread ) {
1448 // Filter out on stack monitors collected during stack walk.
1449 oop obj = (oop)mon->object();
1450 bool found = false;
1451 for (int j = 0; j < _owned_monitors_list->length(); j++) {
1452 jobject jobj = ((jvmtiMonitorStackDepthInfo*)_owned_monitors_list->at(j))->monitor;
1453 oop check = JNIHandles::resolve(jobj);
1454 if (check == obj) {
1455 // On stack monitor already collected during the stack walk.
1456 found = true;
1457 break;
1458 }
1459 }
1460 if (found == false) {
1461 // This is off stack monitor (e.g. acquired via jni MonitorEnter).
1462 jvmtiError err;
1463 jvmtiMonitorStackDepthInfo *jmsdi;
1464 err = _env->allocate(sizeof(jvmtiMonitorStackDepthInfo), (unsigned char **)&jmsdi);
1465 if (err != JVMTI_ERROR_NONE) {
1466 _error = err;
1467 return;
1468 }
1469 Handle hobj(Thread::current(), obj);
1470 jmsdi->monitor = _env->jni_reference(_calling_thread, hobj);
1471 // stack depth is unknown for this monitor.
1472 jmsdi->stack_depth = -1;
1473 _owned_monitors_list->append(jmsdi);
1474 }
1475 }
1476 }
1477
1478 GrowableArray<OopHandle>* JvmtiModuleClosure::_tbl = NULL;
1479
1480 jvmtiError
1481 JvmtiModuleClosure::get_all_modules(JvmtiEnv* env, jint* module_count_ptr, jobject** modules_ptr) {
1482 ResourceMark rm;
1483 MutexLocker ml(Module_lock);
1484
1485 _tbl = new GrowableArray<OopHandle>(77);
1486 if (_tbl == NULL) {
1487 return JVMTI_ERROR_OUT_OF_MEMORY;
1488 }
1489
1490 // Iterate over all the modules loaded to the system.
1491 ClassLoaderDataGraph::modules_do(&do_module);
1492
1493 jint len = _tbl->length();
1494 guarantee(len > 0, "at least one module must be present");
1495
1496 jobject* array = (jobject*)env->jvmtiMalloc((jlong)(len * sizeof(jobject)));
1497 if (array == NULL) {
1498 return JVMTI_ERROR_OUT_OF_MEMORY;
1499 }
1500 for (jint idx = 0; idx < len; idx++) {
1501 array[idx] = JNIHandles::make_local(Thread::current(), _tbl->at(idx).resolve());
1502 }
1503 _tbl = NULL;
1504 *modules_ptr = array;
1505 *module_count_ptr = len;
1506 return JVMTI_ERROR_NONE;
1507 }
1508
1509 void
1510 VM_UpdateForPopTopFrame::doit() {
1511 JavaThread* jt = _state->get_thread();
1512 ThreadsListHandle tlh;
1513 if (jt != NULL && tlh.includes(jt) && !jt->is_exiting() && jt->threadObj() != NULL) {
1514 _state->update_for_pop_top_frame();
1515 } else {
1516 _result = JVMTI_ERROR_THREAD_NOT_ALIVE;
1517 }
1518 }
1519
1520 void
1521 VM_SetFramePop::doit() {
1522 JavaThread* jt = _state->get_thread();
1523 ThreadsListHandle tlh;
1524 if (jt != NULL && tlh.includes(jt) && !jt->is_exiting() && jt->threadObj() != NULL) {
1525 int frame_number = _state->count_frames() - _depth;
1526 _state->env_thread_state((JvmtiEnvBase*)_env)->set_frame_pop(frame_number);
1527 } else {
1528 _result = JVMTI_ERROR_THREAD_NOT_ALIVE;
1529 }
1530 }
1531
1532 void
1533 VM_GetOwnedMonitorInfo::doit() {
1534 _result = JVMTI_ERROR_THREAD_NOT_ALIVE;
1535 ThreadsListHandle tlh;
1536 if (_java_thread != NULL && tlh.includes(_java_thread)
1537 && !_java_thread->is_exiting() && _java_thread->threadObj() != NULL) {
1538 _result = ((JvmtiEnvBase *)_env)->get_owned_monitors(_calling_thread, _java_thread,
1539 _owned_monitors_list);
1540 }
1541 }
1542
1543 void
1544 VM_GetCurrentContendedMonitor::doit() {
1545 _result = JVMTI_ERROR_THREAD_NOT_ALIVE;
1546 ThreadsListHandle tlh;
1547 if (_java_thread != NULL && tlh.includes(_java_thread)
1548 && !_java_thread->is_exiting() && _java_thread->threadObj() != NULL) {
1549 _result = ((JvmtiEnvBase *)_env)->get_current_contended_monitor(_calling_thread,_java_thread,_owned_monitor_ptr);
1550 }
1551 }
1552
1553 void
1554 VM_GetStackTrace::doit() {
1555 _result = JVMTI_ERROR_THREAD_NOT_ALIVE;
1556 ThreadsListHandle tlh;
1557 if (_java_thread != NULL && tlh.includes(_java_thread)
1558 && !_java_thread->is_exiting() && _java_thread->threadObj() != NULL) {
1559 _result = ((JvmtiEnvBase *)_env)->get_stack_trace(_java_thread,
1560 _start_depth, _max_count,
1561 _frame_buffer, _count_ptr);
1562 }
1563 }
1564
1565 void
1566 VM_GetFrameCount::doit() {
1567 _result = JVMTI_ERROR_THREAD_NOT_ALIVE;
1568 JavaThread* jt = _state->get_thread();
1569 ThreadsListHandle tlh;
1570 if (jt != NULL && tlh.includes(jt) && !jt->is_exiting() && jt->threadObj() != NULL) {
1571 _result = ((JvmtiEnvBase*)_env)->get_frame_count(_state, _count_ptr);
1572 }
1573 }
1574
1575 void
1576 VM_GetFrameLocation::doit() {
1577 _result = JVMTI_ERROR_THREAD_NOT_ALIVE;
1578 ThreadsListHandle tlh;
1579 if (_java_thread != NULL && tlh.includes(_java_thread)
1580 && !_java_thread->is_exiting() && _java_thread->threadObj() != NULL) {
1581 _result = ((JvmtiEnvBase*)_env)->get_frame_location(_java_thread, _depth,
1582 _method_ptr, _location_ptr);
1583 }
1584 }