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