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