1/*
2 * Copyright (c) 2003, 2019, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25#include "precompiled.hpp"
26#include "classfile/classLoaderDataGraph.hpp"
27#include "classfile/moduleEntry.hpp"
28#include "classfile/systemDictionary.hpp"
29#include "jvmtifiles/jvmtiEnv.hpp"
30#include "memory/resourceArea.hpp"
31#include "oops/objArrayKlass.hpp"
32#include "oops/objArrayOop.hpp"
33#include "oops/oop.inline.hpp"
34#include "oops/oopHandle.inline.hpp"
35#include "prims/jvmtiEnvBase.hpp"
36#include "prims/jvmtiEventController.inline.hpp"
37#include "prims/jvmtiExtensions.hpp"
38#include "prims/jvmtiImpl.hpp"
39#include "prims/jvmtiManageCapabilities.hpp"
40#include "prims/jvmtiTagMap.hpp"
41#include "prims/jvmtiThreadState.inline.hpp"
42#include "runtime/biasedLocking.hpp"
43#include "runtime/deoptimization.hpp"
44#include "runtime/frame.inline.hpp"
45#include "runtime/handles.inline.hpp"
46#include "runtime/interfaceSupport.inline.hpp"
47#include "runtime/jfieldIDWorkaround.hpp"
48#include "runtime/jniHandles.inline.hpp"
49#include "runtime/objectMonitor.hpp"
50#include "runtime/objectMonitor.inline.hpp"
51#include "runtime/signature.hpp"
52#include "runtime/thread.inline.hpp"
53#include "runtime/threadSMR.hpp"
54#include "runtime/vframe.hpp"
55#include "runtime/vframe_hp.hpp"
56#include "runtime/vmThread.hpp"
57#include "runtime/vmOperations.hpp"
58
59///////////////////////////////////////////////////////////////
60//
61// JvmtiEnvBase
62//
63
64JvmtiEnvBase* JvmtiEnvBase::_head_environment = NULL;
65
66bool JvmtiEnvBase::_globally_initialized = false;
67volatile bool JvmtiEnvBase::_needs_clean_up = false;
68
69jvmtiPhase JvmtiEnvBase::_phase = JVMTI_PHASE_PRIMORDIAL;
70
71volatile int JvmtiEnvBase::_dying_thread_env_iteration_count = 0;
72
73extern jvmtiInterface_1_ jvmti_Interface;
74extern jvmtiInterface_1_ jvmtiTrace_Interface;
75
76
77// perform initializations that must occur before any JVMTI environments
78// are released but which should only be initialized once (no matter
79// how many environments are created).
80void
81JvmtiEnvBase::globally_initialize() {
82 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
83 assert(_globally_initialized == false, "bad call");
84
85 JvmtiManageCapabilities::initialize();
86
87 // register extension functions and events
88 JvmtiExtensions::register_extensions();
89
90#ifdef JVMTI_TRACE
91 JvmtiTrace::initialize();
92#endif
93
94 _globally_initialized = true;
95}
96
97
98void
99JvmtiEnvBase::initialize() {
100 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
101
102 // Add this environment to the end of the environment list (order is important)
103 {
104 // This block of code must not contain any safepoints, as list deallocation
105 // (which occurs at a safepoint) cannot occur simultaneously with this list
106 // addition. Note: NoSafepointVerifier cannot, currently, be used before
107 // threads exist.
108 JvmtiEnvIterator it;
109 JvmtiEnvBase *previous_env = NULL;
110 for (JvmtiEnvBase* env = it.first(); env != NULL; env = it.next(env)) {
111 previous_env = env;
112 }
113 if (previous_env == NULL) {
114 _head_environment = this;
115 } else {
116 previous_env->set_next_environment(this);
117 }
118 }
119
120 if (_globally_initialized == false) {
121 globally_initialize();
122 }
123}
124
125jvmtiPhase
126JvmtiEnvBase::phase() {
127 // For the JVMTI environments possessed the can_generate_early_vmstart:
128 // replace JVMTI_PHASE_PRIMORDIAL with JVMTI_PHASE_START
129 if (_phase == JVMTI_PHASE_PRIMORDIAL &&
130 JvmtiExport::early_vmstart_recorded() &&
131 early_vmstart_env()) {
132 return JVMTI_PHASE_START;
133 }
134 return _phase; // Normal case
135}
136
137bool
138JvmtiEnvBase::is_valid() {
139 jint value = 0;
140
141 // This object might not be a JvmtiEnvBase so we can't assume
142 // the _magic field is properly aligned. Get the value in a safe
143 // way and then check against JVMTI_MAGIC.
144
145 switch (sizeof(_magic)) {
146 case 2:
147 value = Bytes::get_native_u2((address)&_magic);
148 break;
149
150 case 4:
151 value = Bytes::get_native_u4((address)&_magic);
152 break;
153
154 case 8:
155 value = Bytes::get_native_u8((address)&_magic);
156 break;
157
158 default:
159 guarantee(false, "_magic field is an unexpected size");
160 }
161
162 return value == JVMTI_MAGIC;
163}
164
165
166bool
167JvmtiEnvBase::use_version_1_0_semantics() {
168 int major, minor, micro;
169
170 JvmtiExport::decode_version_values(_version, &major, &minor, &micro);
171 return major == 1 && minor == 0; // micro version doesn't matter here
172}
173
174
175bool
176JvmtiEnvBase::use_version_1_1_semantics() {
177 int major, minor, micro;
178
179 JvmtiExport::decode_version_values(_version, &major, &minor, &micro);
180 return major == 1 && minor == 1; // micro version doesn't matter here
181}
182
183bool
184JvmtiEnvBase::use_version_1_2_semantics() {
185 int major, minor, micro;
186
187 JvmtiExport::decode_version_values(_version, &major, &minor, &micro);
188 return major == 1 && minor == 2; // micro version doesn't matter here
189}
190
191
192JvmtiEnvBase::JvmtiEnvBase(jint version) : _env_event_enable() {
193 _version = version;
194 _env_local_storage = NULL;
195 _tag_map = NULL;
196 _native_method_prefix_count = 0;
197 _native_method_prefixes = NULL;
198 _next = NULL;
199 _class_file_load_hook_ever_enabled = false;
200
201 // Moot since ClassFileLoadHook not yet enabled.
202 // But "true" will give a more predictable ClassFileLoadHook behavior
203 // for environment creation during ClassFileLoadHook.
204 _is_retransformable = true;
205
206 // all callbacks initially NULL
207 memset(&_event_callbacks,0,sizeof(jvmtiEventCallbacks));
208
209 // all capabilities initially off
210 memset(&_current_capabilities, 0, sizeof(_current_capabilities));
211
212 // all prohibited capabilities initially off
213 memset(&_prohibited_capabilities, 0, sizeof(_prohibited_capabilities));
214
215 _magic = JVMTI_MAGIC;
216
217 JvmtiEventController::env_initialize((JvmtiEnv*)this);
218
219#ifdef JVMTI_TRACE
220 _jvmti_external.functions = TraceJVMTI != NULL ? &jvmtiTrace_Interface : &jvmti_Interface;
221#else
222 _jvmti_external.functions = &jvmti_Interface;
223#endif
224}
225
226
227void
228JvmtiEnvBase::dispose() {
229
230#ifdef JVMTI_TRACE
231 JvmtiTrace::shutdown();
232#endif
233
234 // Dispose of event info and let the event controller call us back
235 // in a locked state (env_dispose, below)
236 JvmtiEventController::env_dispose(this);
237}
238
239void
240JvmtiEnvBase::env_dispose() {
241 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
242
243 // We have been entered with all events disabled on this environment.
244 // A race to re-enable events (by setting callbacks) is prevented by
245 // checking for a valid environment when setting callbacks (while
246 // holding the JvmtiThreadState_lock).
247
248 // Mark as invalid.
249 _magic = DISPOSED_MAGIC;
250
251 // Relinquish all capabilities.
252 jvmtiCapabilities *caps = get_capabilities();
253 JvmtiManageCapabilities::relinquish_capabilities(caps, caps, caps);
254
255 // Same situation as with events (see above)
256 set_native_method_prefixes(0, NULL);
257
258 JvmtiTagMap* tag_map_to_deallocate = _tag_map;
259 set_tag_map(NULL);
260 // A tag map can be big, deallocate it now
261 if (tag_map_to_deallocate != NULL) {
262 delete tag_map_to_deallocate;
263 }
264
265 _needs_clean_up = true;
266}
267
268
269JvmtiEnvBase::~JvmtiEnvBase() {
270 assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
271
272 // There is a small window of time during which the tag map of a
273 // disposed environment could have been reallocated.
274 // Make sure it is gone.
275 JvmtiTagMap* tag_map_to_deallocate = _tag_map;
276 set_tag_map(NULL);
277 // A tag map can be big, deallocate it now
278 if (tag_map_to_deallocate != NULL) {
279 delete tag_map_to_deallocate;
280 }
281
282 _magic = BAD_MAGIC;
283}
284
285
286void
287JvmtiEnvBase::periodic_clean_up() {
288 assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
289
290 // JvmtiEnvBase reference is saved in JvmtiEnvThreadState. So
291 // clean up JvmtiThreadState before deleting JvmtiEnv pointer.
292 JvmtiThreadState::periodic_clean_up();
293
294 // Unlink all invalid environments from the list of environments
295 // and deallocate them
296 JvmtiEnvIterator it;
297 JvmtiEnvBase* previous_env = NULL;
298 JvmtiEnvBase* env = it.first();
299 while (env != NULL) {
300 if (env->is_valid()) {
301 previous_env = env;
302 env = it.next(env);
303 } else {
304 // This one isn't valid, remove it from the list and deallocate it
305 JvmtiEnvBase* defunct_env = env;
306 env = it.next(env);
307 if (previous_env == NULL) {
308 _head_environment = env;
309 } else {
310 previous_env->set_next_environment(env);
311 }
312 delete defunct_env;
313 }
314 }
315
316}
317
318
319void
320JvmtiEnvBase::check_for_periodic_clean_up() {
321 assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
322
323 class ThreadInsideIterationClosure: public ThreadClosure {
324 private:
325 bool _inside;
326 public:
327 ThreadInsideIterationClosure() : _inside(false) {};
328
329 void do_thread(Thread* thread) {
330 _inside |= thread->is_inside_jvmti_env_iteration();
331 }
332
333 bool is_inside_jvmti_env_iteration() {
334 return _inside;
335 }
336 };
337
338 if (_needs_clean_up) {
339 // Check if we are currently iterating environment,
340 // deallocation should not occur if we are
341 ThreadInsideIterationClosure tiic;
342 Threads::threads_do(&tiic);
343 if (!tiic.is_inside_jvmti_env_iteration() &&
344 !is_inside_dying_thread_env_iteration()) {
345 _needs_clean_up = false;
346 JvmtiEnvBase::periodic_clean_up();
347 }
348 }
349}
350
351
352void
353JvmtiEnvBase::record_first_time_class_file_load_hook_enabled() {
354 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(),
355 "sanity check");
356
357 if (!_class_file_load_hook_ever_enabled) {
358 _class_file_load_hook_ever_enabled = true;
359
360 if (get_capabilities()->can_retransform_classes) {
361 _is_retransformable = true;
362 } else {
363 _is_retransformable = false;
364
365 // cannot add retransform capability after ClassFileLoadHook has been enabled
366 get_prohibited_capabilities()->can_retransform_classes = 1;
367 }
368 }
369}
370
371
372void
373JvmtiEnvBase::record_class_file_load_hook_enabled() {
374 if (!_class_file_load_hook_ever_enabled) {
375 if (Threads::number_of_threads() == 0) {
376 record_first_time_class_file_load_hook_enabled();
377 } else {
378 MutexLocker mu(JvmtiThreadState_lock);
379 record_first_time_class_file_load_hook_enabled();
380 }
381 }
382}
383
384
385jvmtiError
386JvmtiEnvBase::set_native_method_prefixes(jint prefix_count, char** prefixes) {
387 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(),
388 "sanity check");
389
390 int old_prefix_count = get_native_method_prefix_count();
391 char **old_prefixes = get_native_method_prefixes();
392
393 // allocate and install the new prefixex
394 if (prefix_count == 0 || !is_valid()) {
395 _native_method_prefix_count = 0;
396 _native_method_prefixes = NULL;
397 } else {
398 // there are prefixes, allocate an array to hold them, and fill it
399 char** new_prefixes = (char**)os::malloc((prefix_count) * sizeof(char*), mtInternal);
400 if (new_prefixes == NULL) {
401 return JVMTI_ERROR_OUT_OF_MEMORY;
402 }
403 for (int i = 0; i < prefix_count; i++) {
404 char* prefix = prefixes[i];
405 if (prefix == NULL) {
406 for (int j = 0; j < (i-1); j++) {
407 os::free(new_prefixes[j]);
408 }
409 os::free(new_prefixes);
410 return JVMTI_ERROR_NULL_POINTER;
411 }
412 prefix = os::strdup(prefixes[i]);
413 if (prefix == NULL) {
414 for (int j = 0; j < (i-1); j++) {
415 os::free(new_prefixes[j]);
416 }
417 os::free(new_prefixes);
418 return JVMTI_ERROR_OUT_OF_MEMORY;
419 }
420 new_prefixes[i] = prefix;
421 }
422 _native_method_prefix_count = prefix_count;
423 _native_method_prefixes = new_prefixes;
424 }
425
426 // now that we know the new prefixes have been successfully installed we can
427 // safely remove the old ones
428 if (old_prefix_count != 0) {
429 for (int i = 0; i < old_prefix_count; i++) {
430 os::free(old_prefixes[i]);
431 }
432 os::free(old_prefixes);
433 }
434
435 return JVMTI_ERROR_NONE;
436}
437
438
439// Collect all the prefixes which have been set in any JVM TI environments
440// by the SetNativeMethodPrefix(es) functions. Be sure to maintain the
441// order of environments and the order of prefixes within each environment.
442// Return in a resource allocated array.
443char**
444JvmtiEnvBase::get_all_native_method_prefixes(int* count_ptr) {
445 assert(Threads::number_of_threads() == 0 ||
446 SafepointSynchronize::is_at_safepoint() ||
447 JvmtiThreadState_lock->is_locked(),
448 "sanity check");
449
450 int total_count = 0;
451 GrowableArray<char*>* prefix_array =new GrowableArray<char*>(5);
452
453 JvmtiEnvIterator it;
454 for (JvmtiEnvBase* env = it.first(); env != NULL; env = it.next(env)) {
455 int prefix_count = env->get_native_method_prefix_count();
456 char** prefixes = env->get_native_method_prefixes();
457 for (int j = 0; j < prefix_count; j++) {
458 // retrieve a prefix and so that it is safe against asynchronous changes
459 // copy it into the resource area
460 char* prefix = prefixes[j];
461 char* prefix_copy = NEW_RESOURCE_ARRAY(char, strlen(prefix)+1);
462 strcpy(prefix_copy, prefix);
463 prefix_array->at_put_grow(total_count++, prefix_copy);
464 }
465 }
466
467 char** all_prefixes = NEW_RESOURCE_ARRAY(char*, total_count);
468 char** p = all_prefixes;
469 for (int i = 0; i < total_count; ++i) {
470 *p++ = prefix_array->at(i);
471 }
472 *count_ptr = total_count;
473 return all_prefixes;
474}
475
476void
477JvmtiEnvBase::set_event_callbacks(const jvmtiEventCallbacks* callbacks,
478 jint size_of_callbacks) {
479 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check");
480
481 size_t byte_cnt = sizeof(jvmtiEventCallbacks);
482
483 // clear in either case to be sure we got any gap between sizes
484 memset(&_event_callbacks, 0, byte_cnt);
485
486 // Now that JvmtiThreadState_lock is held, prevent a possible race condition where events
487 // are re-enabled by a call to set event callbacks where the DisposeEnvironment
488 // occurs after the boiler-plate environment check and before the lock is acquired.
489 if (callbacks != NULL && is_valid()) {
490 if (size_of_callbacks < (jint)byte_cnt) {
491 byte_cnt = size_of_callbacks;
492 }
493 memcpy(&_event_callbacks, callbacks, byte_cnt);
494 }
495}
496
497
498// In the fullness of time, all users of the method should instead
499// directly use allocate, besides being cleaner and faster, this will
500// mean much better out of memory handling
501unsigned char *
502JvmtiEnvBase::jvmtiMalloc(jlong size) {
503 unsigned char* mem = NULL;
504 jvmtiError result = allocate(size, &mem);
505 assert(result == JVMTI_ERROR_NONE, "Allocate failed");
506 return mem;
507}
508
509
510// Handle management
511
512jobject JvmtiEnvBase::jni_reference(Handle hndl) {
513 return JNIHandles::make_local(hndl());
514}
515
516jobject JvmtiEnvBase::jni_reference(JavaThread *thread, Handle hndl) {
517 return JNIHandles::make_local(thread, hndl());
518}
519
520void JvmtiEnvBase::destroy_jni_reference(jobject jobj) {
521 JNIHandles::destroy_local(jobj);
522}
523
524void JvmtiEnvBase::destroy_jni_reference(JavaThread *thread, jobject jobj) {
525 JNIHandles::destroy_local(jobj); // thread is unused.
526}
527
528//
529// Threads
530//
531
532jobject *
533JvmtiEnvBase::new_jobjectArray(int length, Handle *handles) {
534 if (length == 0) {
535 return NULL;
536 }
537
538 jobject *objArray = (jobject *) jvmtiMalloc(sizeof(jobject) * length);
539 NULL_CHECK(objArray, NULL);
540
541 for (int i=0; i<length; i++) {
542 objArray[i] = jni_reference(handles[i]);
543 }
544 return objArray;
545}
546
547jthread *
548JvmtiEnvBase::new_jthreadArray(int length, Handle *handles) {
549 return (jthread *) new_jobjectArray(length,handles);
550}
551
552jthreadGroup *
553JvmtiEnvBase::new_jthreadGroupArray(int length, Handle *handles) {
554 return (jthreadGroup *) new_jobjectArray(length,handles);
555}
556
557// return the vframe on the specified thread and depth, NULL if no such frame
558vframe*
559JvmtiEnvBase::vframeFor(JavaThread* java_thread, jint depth) {
560 if (!java_thread->has_last_Java_frame()) {
561 return NULL;
562 }
563 RegisterMap reg_map(java_thread);
564 vframe *vf = java_thread->last_java_vframe(&reg_map);
565 int d = 0;
566 while ((vf != NULL) && (d < depth)) {
567 vf = vf->java_sender();
568 d++;
569 }
570 return vf;
571}
572
573
574//
575// utilities: JNI objects
576//
577
578
579jclass
580JvmtiEnvBase::get_jni_class_non_null(Klass* k) {
581 assert(k != NULL, "k != NULL");
582 Thread *thread = Thread::current();
583 return (jclass)jni_reference(Handle(thread, k->java_mirror()));
584}
585
586//
587// Field Information
588//
589
590bool
591JvmtiEnvBase::get_field_descriptor(Klass* k, jfieldID field, fieldDescriptor* fd) {
592 if (!jfieldIDWorkaround::is_valid_jfieldID(k, field)) {
593 return false;
594 }
595 bool found = false;
596 if (jfieldIDWorkaround::is_static_jfieldID(field)) {
597 JNIid* id = jfieldIDWorkaround::from_static_jfieldID(field);
598 found = id->find_local_field(fd);
599 } else {
600 // Non-static field. The fieldID is really the offset of the field within the object.
601 int offset = jfieldIDWorkaround::from_instance_jfieldID(k, field);
602 found = InstanceKlass::cast(k)->find_field_from_offset(offset, false, fd);
603 }
604 return found;
605}
606
607//
608// Object Monitor Information
609//
610
611//
612// Count the number of objects for a lightweight monitor. The hobj
613// parameter is object that owns the monitor so this routine will
614// count the number of times the same object was locked by frames
615// in java_thread.
616//
617jint
618JvmtiEnvBase::count_locked_objects(JavaThread *java_thread, Handle hobj) {
619 jint ret = 0;
620 if (!java_thread->has_last_Java_frame()) {
621 return ret; // no Java frames so no monitors
622 }
623
624 ResourceMark rm;
625 HandleMark hm;
626 RegisterMap reg_map(java_thread);
627
628 for(javaVFrame *jvf=java_thread->last_java_vframe(&reg_map); jvf != NULL;
629 jvf = jvf->java_sender()) {
630 GrowableArray<MonitorInfo*>* mons = jvf->monitors();
631 if (!mons->is_empty()) {
632 for (int i = 0; i < mons->length(); i++) {
633 MonitorInfo *mi = mons->at(i);
634 if (mi->owner_is_scalar_replaced()) continue;
635
636 // see if owner of the monitor is our object
637 if (mi->owner() != NULL && mi->owner() == hobj()) {
638 ret++;
639 }
640 }
641 }
642 }
643 return ret;
644}
645
646
647
648jvmtiError
649JvmtiEnvBase::get_current_contended_monitor(JavaThread *calling_thread, JavaThread *java_thread, jobject *monitor_ptr) {
650#ifdef ASSERT
651 uint32_t debug_bits = 0;
652#endif
653 assert((SafepointSynchronize::is_at_safepoint() ||
654 java_thread->is_thread_fully_suspended(false, &debug_bits)),
655 "at safepoint or target thread is suspended");
656 oop obj = NULL;
657 ObjectMonitor *mon = java_thread->current_waiting_monitor();
658 if (mon == NULL) {
659 // thread is not doing an Object.wait() call
660 mon = java_thread->current_pending_monitor();
661 if (mon != NULL) {
662 // The thread is trying to enter() or raw_enter() an ObjectMonitor.
663 obj = (oop)mon->object();
664 // If obj == NULL, then ObjectMonitor is raw which doesn't count
665 // as contended for this API
666 }
667 // implied else: no contended ObjectMonitor
668 } else {
669 // thread is doing an Object.wait() call
670 obj = (oop)mon->object();
671 assert(obj != NULL, "Object.wait() should have an object");
672 }
673
674 if (obj == NULL) {
675 *monitor_ptr = NULL;
676 } else {
677 HandleMark hm;
678 Handle hobj(Thread::current(), obj);
679 *monitor_ptr = jni_reference(calling_thread, hobj);
680 }
681 return JVMTI_ERROR_NONE;
682}
683
684
685jvmtiError
686JvmtiEnvBase::get_owned_monitors(JavaThread *calling_thread, JavaThread* java_thread,
687 GrowableArray<jvmtiMonitorStackDepthInfo*> *owned_monitors_list) {
688 jvmtiError err = JVMTI_ERROR_NONE;
689#ifdef ASSERT
690 uint32_t debug_bits = 0;
691#endif
692 assert((SafepointSynchronize::is_at_safepoint() ||
693 java_thread->is_thread_fully_suspended(false, &debug_bits)),
694 "at safepoint or target thread is suspended");
695
696 if (java_thread->has_last_Java_frame()) {
697 ResourceMark rm;
698 HandleMark hm;
699 RegisterMap reg_map(java_thread);
700
701 int depth = 0;
702 for (javaVFrame *jvf = java_thread->last_java_vframe(&reg_map); jvf != NULL;
703 jvf = jvf->java_sender()) {
704 if (MaxJavaStackTraceDepth == 0 || depth++ < MaxJavaStackTraceDepth) { // check for stack too deep
705 // add locked objects for this frame into list
706 err = get_locked_objects_in_frame(calling_thread, java_thread, jvf, owned_monitors_list, depth-1);
707 if (err != JVMTI_ERROR_NONE) {
708 return err;
709 }
710 }
711 }
712 }
713
714 // Get off stack monitors. (e.g. acquired via jni MonitorEnter).
715 JvmtiMonitorClosure jmc(java_thread, calling_thread, owned_monitors_list, this);
716 ObjectSynchronizer::monitors_iterate(&jmc);
717 err = jmc.error();
718
719 return err;
720}
721
722// Save JNI local handles for any objects that this frame owns.
723jvmtiError
724JvmtiEnvBase::get_locked_objects_in_frame(JavaThread* calling_thread, JavaThread* java_thread,
725 javaVFrame *jvf, GrowableArray<jvmtiMonitorStackDepthInfo*>* owned_monitors_list, jint stack_depth) {
726 jvmtiError err = JVMTI_ERROR_NONE;
727 ResourceMark rm;
728
729 GrowableArray<MonitorInfo*>* mons = jvf->monitors();
730 if (mons->is_empty()) {
731 return err; // this javaVFrame holds no monitors
732 }
733
734 HandleMark hm;
735 oop wait_obj = NULL;
736 {
737 // save object of current wait() call (if any) for later comparison
738 ObjectMonitor *mon = java_thread->current_waiting_monitor();
739 if (mon != NULL) {
740 wait_obj = (oop)mon->object();
741 }
742 }
743 oop pending_obj = NULL;
744 {
745 // save object of current enter() call (if any) for later comparison
746 ObjectMonitor *mon = java_thread->current_pending_monitor();
747 if (mon != NULL) {
748 pending_obj = (oop)mon->object();
749 }
750 }
751
752 for (int i = 0; i < mons->length(); i++) {
753 MonitorInfo *mi = mons->at(i);
754
755 if (mi->owner_is_scalar_replaced()) continue;
756
757 oop obj = mi->owner();
758 if (obj == NULL) {
759 // this monitor doesn't have an owning object so skip it
760 continue;
761 }
762
763 if (wait_obj == obj) {
764 // the thread is waiting on this monitor so it isn't really owned
765 continue;
766 }
767
768 if (pending_obj == obj) {
769 // the thread is pending on this monitor so it isn't really owned
770 continue;
771 }
772
773 if (owned_monitors_list->length() > 0) {
774 // Our list has at least one object on it so we have to check
775 // for recursive object locking
776 bool found = false;
777 for (int j = 0; j < owned_monitors_list->length(); j++) {
778 jobject jobj = ((jvmtiMonitorStackDepthInfo*)owned_monitors_list->at(j))->monitor;
779 oop check = JNIHandles::resolve(jobj);
780 if (check == obj) {
781 found = true; // we found the object
782 break;
783 }
784 }
785
786 if (found) {
787 // already have this object so don't include it
788 continue;
789 }
790 }
791
792 // add the owning object to our list
793 jvmtiMonitorStackDepthInfo *jmsdi;
794 err = allocate(sizeof(jvmtiMonitorStackDepthInfo), (unsigned char **)&jmsdi);
795 if (err != JVMTI_ERROR_NONE) {
796 return err;
797 }
798 Handle hobj(Thread::current(), obj);
799 jmsdi->monitor = jni_reference(calling_thread, hobj);
800 jmsdi->stack_depth = stack_depth;
801 owned_monitors_list->append(jmsdi);
802 }
803
804 return err;
805}
806
807jvmtiError
808JvmtiEnvBase::get_stack_trace(JavaThread *java_thread,
809 jint start_depth, jint max_count,
810 jvmtiFrameInfo* frame_buffer, jint* count_ptr) {
811#ifdef ASSERT
812 uint32_t debug_bits = 0;
813#endif
814 assert((SafepointSynchronize::is_at_safepoint() ||
815 java_thread->is_thread_fully_suspended(false, &debug_bits)),
816 "at safepoint or target thread is suspended");
817 int count = 0;
818 if (java_thread->has_last_Java_frame()) {
819 RegisterMap reg_map(java_thread);
820 Thread* current_thread = Thread::current();
821 ResourceMark rm(current_thread);
822 javaVFrame *jvf = java_thread->last_java_vframe(&reg_map);
823 HandleMark hm(current_thread);
824 if (start_depth != 0) {
825 if (start_depth > 0) {
826 for (int j = 0; j < start_depth && jvf != NULL; j++) {
827 jvf = jvf->java_sender();
828 }
829 if (jvf == NULL) {
830 // start_depth is deeper than the stack depth
831 return JVMTI_ERROR_ILLEGAL_ARGUMENT;
832 }
833 } else { // start_depth < 0
834 // we are referencing the starting depth based on the oldest
835 // part of the stack.
836 // optimize to limit the number of times that java_sender() is called
837 javaVFrame *jvf_cursor = jvf;
838 javaVFrame *jvf_prev = NULL;
839 javaVFrame *jvf_prev_prev = NULL;
840 int j = 0;
841 while (jvf_cursor != NULL) {
842 jvf_prev_prev = jvf_prev;
843 jvf_prev = jvf_cursor;
844 for (j = 0; j > start_depth && jvf_cursor != NULL; j--) {
845 jvf_cursor = jvf_cursor->java_sender();
846 }
847 }
848 if (j == start_depth) {
849 // previous pointer is exactly where we want to start
850 jvf = jvf_prev;
851 } else {
852 // we need to back up further to get to the right place
853 if (jvf_prev_prev == NULL) {
854 // the -start_depth is greater than the stack depth
855 return JVMTI_ERROR_ILLEGAL_ARGUMENT;
856 }
857 // j now is the number of frames on the stack starting with
858 // jvf_prev, we start from jvf_prev_prev and move older on
859 // the stack that many, the result is -start_depth frames
860 // remaining.
861 jvf = jvf_prev_prev;
862 for (; j < 0; j++) {
863 jvf = jvf->java_sender();
864 }
865 }
866 }
867 }
868 for (; count < max_count && jvf != NULL; count++) {
869 frame_buffer[count].method = jvf->method()->jmethod_id();
870 frame_buffer[count].location = (jvf->method()->is_native() ? -1 : jvf->bci());
871 jvf = jvf->java_sender();
872 }
873 } else {
874 if (start_depth != 0) {
875 // no frames and there is a starting depth
876 return JVMTI_ERROR_ILLEGAL_ARGUMENT;
877 }
878 }
879 *count_ptr = count;
880 return JVMTI_ERROR_NONE;
881}
882
883jvmtiError
884JvmtiEnvBase::get_frame_count(JvmtiThreadState *state, jint *count_ptr) {
885 assert((state != NULL),
886 "JavaThread should create JvmtiThreadState before calling this method");
887 *count_ptr = state->count_frames();
888 return JVMTI_ERROR_NONE;
889}
890
891jvmtiError
892JvmtiEnvBase::get_frame_location(JavaThread *java_thread, jint depth,
893 jmethodID* method_ptr, jlocation* location_ptr) {
894#ifdef ASSERT
895 uint32_t debug_bits = 0;
896#endif
897 assert((SafepointSynchronize::is_at_safepoint() ||
898 java_thread->is_thread_fully_suspended(false, &debug_bits)),
899 "at safepoint or target thread is suspended");
900 Thread* current_thread = Thread::current();
901 ResourceMark rm(current_thread);
902
903 vframe *vf = vframeFor(java_thread, depth);
904 if (vf == NULL) {
905 return JVMTI_ERROR_NO_MORE_FRAMES;
906 }
907
908 // vframeFor should return a java frame. If it doesn't
909 // it means we've got an internal error and we return the
910 // error in product mode. In debug mode we will instead
911 // attempt to cast the vframe to a javaVFrame and will
912 // cause an assertion/crash to allow further diagnosis.
913#ifdef PRODUCT
914 if (!vf->is_java_frame()) {
915 return JVMTI_ERROR_INTERNAL;
916 }
917#endif
918
919 HandleMark hm(current_thread);
920 javaVFrame *jvf = javaVFrame::cast(vf);
921 Method* method = jvf->method();
922 if (method->is_native()) {
923 *location_ptr = -1;
924 } else {
925 *location_ptr = jvf->bci();
926 }
927 *method_ptr = method->jmethod_id();
928
929 return JVMTI_ERROR_NONE;
930}
931
932
933jvmtiError
934JvmtiEnvBase::get_object_monitor_usage(JavaThread* calling_thread, jobject object, jvmtiMonitorUsage* info_ptr) {
935 HandleMark hm;
936 Handle hobj;
937
938 Thread* current_thread = Thread::current();
939 bool at_safepoint = SafepointSynchronize::is_at_safepoint();
940
941 // Check arguments
942 {
943 oop mirror = JNIHandles::resolve_external_guard(object);
944 NULL_CHECK(mirror, JVMTI_ERROR_INVALID_OBJECT);
945 NULL_CHECK(info_ptr, JVMTI_ERROR_NULL_POINTER);
946
947 hobj = Handle(current_thread, mirror);
948 }
949
950 JavaThread *owning_thread = NULL;
951 ObjectMonitor *mon = NULL;
952 jvmtiMonitorUsage ret = {
953 NULL, 0, 0, NULL, 0, NULL
954 };
955
956 uint32_t debug_bits = 0;
957 // first derive the object's owner and entry_count (if any)
958 {
959 // Revoke any biases before querying the mark word
960 if (at_safepoint) {
961 BiasedLocking::revoke_at_safepoint(hobj);
962 } else {
963 BiasedLocking::revoke_and_rebias(hobj, false, calling_thread);
964 }
965
966 address owner = NULL;
967 {
968 markOop mark = hobj()->mark();
969
970 if (!mark->has_monitor()) {
971 // this object has a lightweight monitor
972
973 if (mark->has_locker()) {
974 owner = (address)mark->locker(); // save the address of the Lock word
975 }
976 // implied else: no owner
977 } else {
978 // this object has a heavyweight monitor
979 mon = mark->monitor();
980
981 // The owner field of a heavyweight monitor may be NULL for no
982 // owner, a JavaThread * or it may still be the address of the
983 // Lock word in a JavaThread's stack. A monitor can be inflated
984 // by a non-owning JavaThread, but only the owning JavaThread
985 // can change the owner field from the Lock word to the
986 // JavaThread * and it may not have done that yet.
987 owner = (address)mon->owner();
988 }
989 }
990
991 if (owner != NULL) {
992 // Use current thread since function can be called from a
993 // JavaThread or the VMThread.
994 ThreadsListHandle tlh;
995 // This monitor is owned so we have to find the owning JavaThread.
996 owning_thread = Threads::owning_thread_from_monitor_owner(tlh.list(), owner);
997 // Cannot assume (owning_thread != NULL) here because this function
998 // may not have been called at a safepoint and the owning_thread
999 // might not be suspended.
1000 if (owning_thread != NULL) {
1001 // The monitor's owner either has to be the current thread, at safepoint
1002 // or it has to be suspended. Any of these conditions will prevent both
1003 // contending and waiting threads from modifying the state of
1004 // the monitor.
1005 if (!at_safepoint && !owning_thread->is_thread_fully_suspended(true, &debug_bits)) {
1006 // Don't worry! This return of JVMTI_ERROR_THREAD_NOT_SUSPENDED
1007 // will not make it back to the JVM/TI agent. The error code will
1008 // get intercepted in JvmtiEnv::GetObjectMonitorUsage() which
1009 // will retry the call via a VM_GetObjectMonitorUsage VM op.
1010 return JVMTI_ERROR_THREAD_NOT_SUSPENDED;
1011 }
1012 HandleMark hm;
1013 Handle th(current_thread, owning_thread->threadObj());
1014 ret.owner = (jthread)jni_reference(calling_thread, th);
1015 }
1016 // implied else: no owner
1017 } // ThreadsListHandle is destroyed here.
1018
1019 if (owning_thread != NULL) { // monitor is owned
1020 // The recursions field of a monitor does not reflect recursions
1021 // as lightweight locks before inflating the monitor are not included.
1022 // We have to count the number of recursive monitor entries the hard way.
1023 // We pass a handle to survive any GCs along the way.
1024 ResourceMark rm;
1025 ret.entry_count = count_locked_objects(owning_thread, hobj);
1026 }
1027 // implied else: entry_count == 0
1028 }
1029
1030 jint nWant = 0, nWait = 0;
1031 if (mon != NULL) {
1032 // this object has a heavyweight monitor
1033 nWant = mon->contentions(); // # of threads contending for monitor
1034 nWait = mon->waiters(); // # of threads in Object.wait()
1035 ret.waiter_count = nWant + nWait;
1036 ret.notify_waiter_count = nWait;
1037 } else {
1038 // this object has a lightweight monitor
1039 ret.waiter_count = 0;
1040 ret.notify_waiter_count = 0;
1041 }
1042
1043 // Allocate memory for heavyweight and lightweight monitor.
1044 jvmtiError err;
1045 err = allocate(ret.waiter_count * sizeof(jthread *), (unsigned char**)&ret.waiters);
1046 if (err != JVMTI_ERROR_NONE) {
1047 return err;
1048 }
1049 err = allocate(ret.notify_waiter_count * sizeof(jthread *),
1050 (unsigned char**)&ret.notify_waiters);
1051 if (err != JVMTI_ERROR_NONE) {
1052 deallocate((unsigned char*)ret.waiters);
1053 return err;
1054 }
1055
1056 // now derive the rest of the fields
1057 if (mon != NULL) {
1058 // this object has a heavyweight monitor
1059
1060 // Number of waiters may actually be less than the waiter count.
1061 // So NULL out memory so that unused memory will be NULL.
1062 memset(ret.waiters, 0, ret.waiter_count * sizeof(jthread *));
1063 memset(ret.notify_waiters, 0, ret.notify_waiter_count * sizeof(jthread *));
1064
1065 if (ret.waiter_count > 0) {
1066 // we have contending and/or waiting threads
1067 HandleMark hm;
1068 // Use current thread since function can be called from a
1069 // JavaThread or the VMThread.
1070 ThreadsListHandle tlh;
1071 if (nWant > 0) {
1072 // we have contending threads
1073 ResourceMark rm;
1074 // get_pending_threads returns only java thread so we do not need to
1075 // check for non java threads.
1076 GrowableArray<JavaThread*>* wantList = Threads::get_pending_threads(tlh.list(), nWant, (address)mon);
1077 if (wantList->length() < nWant) {
1078 // robustness: the pending list has gotten smaller
1079 nWant = wantList->length();
1080 }
1081 for (int i = 0; i < nWant; i++) {
1082 JavaThread *pending_thread = wantList->at(i);
1083 // If the monitor has no owner, then a non-suspended contending
1084 // thread could potentially change the state of the monitor by
1085 // entering it. The JVM/TI spec doesn't allow this.
1086 if (owning_thread == NULL && !at_safepoint &&
1087 !pending_thread->is_thread_fully_suspended(true, &debug_bits)) {
1088 if (ret.owner != NULL) {
1089 destroy_jni_reference(calling_thread, ret.owner);
1090 }
1091 for (int j = 0; j < i; j++) {
1092 destroy_jni_reference(calling_thread, ret.waiters[j]);
1093 }
1094 deallocate((unsigned char*)ret.waiters);
1095 deallocate((unsigned char*)ret.notify_waiters);
1096 return JVMTI_ERROR_THREAD_NOT_SUSPENDED;
1097 }
1098 Handle th(current_thread, pending_thread->threadObj());
1099 ret.waiters[i] = (jthread)jni_reference(calling_thread, th);
1100 }
1101 }
1102 if (nWait > 0) {
1103 // we have threads in Object.wait()
1104 int offset = nWant; // add after any contending threads
1105 ObjectWaiter *waiter = mon->first_waiter();
1106 for (int i = 0, j = 0; i < nWait; i++) {
1107 if (waiter == NULL) {
1108 // robustness: the waiting list has gotten smaller
1109 nWait = j;
1110 break;
1111 }
1112 Thread *t = mon->thread_of_waiter(waiter);
1113 if (t != NULL && t->is_Java_thread()) {
1114 JavaThread *wjava_thread = (JavaThread *)t;
1115 // If the thread was found on the ObjectWaiter list, then
1116 // it has not been notified. This thread can't change the
1117 // state of the monitor so it doesn't need to be suspended.
1118 Handle th(current_thread, wjava_thread->threadObj());
1119 ret.waiters[offset + j] = (jthread)jni_reference(calling_thread, th);
1120 ret.notify_waiters[j++] = (jthread)jni_reference(calling_thread, th);
1121 }
1122 waiter = mon->next_waiter(waiter);
1123 }
1124 }
1125 } // ThreadsListHandle is destroyed here.
1126
1127 // Adjust count. nWant and nWait count values may be less than original.
1128 ret.waiter_count = nWant + nWait;
1129 ret.notify_waiter_count = nWait;
1130 } else {
1131 // this object has a lightweight monitor and we have nothing more
1132 // to do here because the defaults are just fine.
1133 }
1134
1135 // we don't update return parameter unless everything worked
1136 *info_ptr = ret;
1137
1138 return JVMTI_ERROR_NONE;
1139}
1140
1141ResourceTracker::ResourceTracker(JvmtiEnv* env) {
1142 _env = env;
1143 _allocations = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<unsigned char*>(20, true);
1144 _failed = false;
1145}
1146ResourceTracker::~ResourceTracker() {
1147 if (_failed) {
1148 for (int i=0; i<_allocations->length(); i++) {
1149 _env->deallocate(_allocations->at(i));
1150 }
1151 }
1152 delete _allocations;
1153}
1154
1155jvmtiError ResourceTracker::allocate(jlong size, unsigned char** mem_ptr) {
1156 unsigned char *ptr;
1157 jvmtiError err = _env->allocate(size, &ptr);
1158 if (err == JVMTI_ERROR_NONE) {
1159 _allocations->append(ptr);
1160 *mem_ptr = ptr;
1161 } else {
1162 *mem_ptr = NULL;
1163 _failed = true;
1164 }
1165 return err;
1166 }
1167
1168unsigned char* ResourceTracker::allocate(jlong size) {
1169 unsigned char* ptr;
1170 allocate(size, &ptr);
1171 return ptr;
1172}
1173
1174char* ResourceTracker::strdup(const char* str) {
1175 char *dup_str = (char*)allocate(strlen(str)+1);
1176 if (dup_str != NULL) {
1177 strcpy(dup_str, str);
1178 }
1179 return dup_str;
1180}
1181
1182struct StackInfoNode {
1183 struct StackInfoNode *next;
1184 jvmtiStackInfo info;
1185};
1186
1187// Create a jvmtiStackInfo inside a linked list node and create a
1188// buffer for the frame information, both allocated as resource objects.
1189// Fill in both the jvmtiStackInfo and the jvmtiFrameInfo.
1190// Note that either or both of thr and thread_oop
1191// may be null if the thread is new or has exited.
1192void
1193VM_GetMultipleStackTraces::fill_frames(jthread jt, JavaThread *thr, oop thread_oop) {
1194 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
1195
1196 jint state = 0;
1197 struct StackInfoNode *node = NEW_RESOURCE_OBJ(struct StackInfoNode);
1198 jvmtiStackInfo *infop = &(node->info);
1199 node->next = head();
1200 set_head(node);
1201 infop->frame_count = 0;
1202 infop->thread = jt;
1203
1204 if (thread_oop != NULL) {
1205 // get most state bits
1206 state = (jint)java_lang_Thread::get_thread_status(thread_oop);
1207 }
1208
1209 if (thr != NULL) { // add more state bits if there is a JavaThead to query
1210 // same as is_being_ext_suspended() but without locking
1211 if (thr->is_ext_suspended() || thr->is_external_suspend()) {
1212 state |= JVMTI_THREAD_STATE_SUSPENDED;
1213 }
1214 JavaThreadState jts = thr->thread_state();
1215 if (jts == _thread_in_native) {
1216 state |= JVMTI_THREAD_STATE_IN_NATIVE;
1217 }
1218 OSThread* osThread = thr->osthread();
1219 if (osThread != NULL && osThread->interrupted()) {
1220 state |= JVMTI_THREAD_STATE_INTERRUPTED;
1221 }
1222 }
1223 infop->state = state;
1224
1225 if (thr != NULL && (state & JVMTI_THREAD_STATE_ALIVE) != 0) {
1226 infop->frame_buffer = NEW_RESOURCE_ARRAY(jvmtiFrameInfo, max_frame_count());
1227 env()->get_stack_trace(thr, 0, max_frame_count(),
1228 infop->frame_buffer, &(infop->frame_count));
1229 } else {
1230 infop->frame_buffer = NULL;
1231 infop->frame_count = 0;
1232 }
1233 _frame_count_total += infop->frame_count;
1234}
1235
1236// Based on the stack information in the linked list, allocate memory
1237// block to return and fill it from the info in the linked list.
1238void
1239VM_GetMultipleStackTraces::allocate_and_fill_stacks(jint thread_count) {
1240 // do I need to worry about alignment issues?
1241 jlong alloc_size = thread_count * sizeof(jvmtiStackInfo)
1242 + _frame_count_total * sizeof(jvmtiFrameInfo);
1243 env()->allocate(alloc_size, (unsigned char **)&_stack_info);
1244
1245 // pointers to move through the newly allocated space as it is filled in
1246 jvmtiStackInfo *si = _stack_info + thread_count; // bottom of stack info
1247 jvmtiFrameInfo *fi = (jvmtiFrameInfo *)si; // is the top of frame info
1248
1249 // copy information in resource area into allocated buffer
1250 // insert stack info backwards since linked list is backwards
1251 // insert frame info forwards
1252 // walk the StackInfoNodes
1253 for (struct StackInfoNode *sin = head(); sin != NULL; sin = sin->next) {
1254 jint frame_count = sin->info.frame_count;
1255 size_t frames_size = frame_count * sizeof(jvmtiFrameInfo);
1256 --si;
1257 memcpy(si, &(sin->info), sizeof(jvmtiStackInfo));
1258 if (frames_size == 0) {
1259 si->frame_buffer = NULL;
1260 } else {
1261 memcpy(fi, sin->info.frame_buffer, frames_size);
1262 si->frame_buffer = fi; // point to the new allocated copy of the frames
1263 fi += frame_count;
1264 }
1265 }
1266 assert(si == _stack_info, "the last copied stack info must be the first record");
1267 assert((unsigned char *)fi == ((unsigned char *)_stack_info) + alloc_size,
1268 "the last copied frame info must be the last record");
1269}
1270
1271
1272void
1273VM_GetThreadListStackTraces::doit() {
1274 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
1275
1276 ResourceMark rm;
1277 ThreadsListHandle tlh;
1278 for (int i = 0; i < _thread_count; ++i) {
1279 jthread jt = _thread_list[i];
1280 JavaThread* java_thread = NULL;
1281 oop thread_oop = NULL;
1282 jvmtiError err = JvmtiExport::cv_external_thread_to_JavaThread(tlh.list(), jt, &java_thread, &thread_oop);
1283 if (err != JVMTI_ERROR_NONE) {
1284 // We got an error code so we don't have a JavaThread *, but
1285 // only return an error from here if we didn't get a valid
1286 // thread_oop.
1287 if (thread_oop == NULL) {
1288 set_result(err);
1289 return;
1290 }
1291 // We have a valid thread_oop.
1292 }
1293 fill_frames(jt, java_thread, thread_oop);
1294 }
1295 allocate_and_fill_stacks(_thread_count);
1296}
1297
1298void
1299VM_GetAllStackTraces::doit() {
1300 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
1301
1302 ResourceMark rm;
1303 _final_thread_count = 0;
1304 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *jt = jtiwh.next(); ) {
1305 oop thread_oop = jt->threadObj();
1306 if (thread_oop != NULL &&
1307 !jt->is_exiting() &&
1308 java_lang_Thread::is_alive(thread_oop) &&
1309 !jt->is_hidden_from_external_view()) {
1310 ++_final_thread_count;
1311 // Handle block of the calling thread is used to create local refs.
1312 fill_frames((jthread)JNIHandles::make_local(_calling_thread, thread_oop),
1313 jt, thread_oop);
1314 }
1315 }
1316 allocate_and_fill_stacks(_final_thread_count);
1317}
1318
1319// Verifies that the top frame is a java frame in an expected state.
1320// Deoptimizes frame if needed.
1321// Checks that the frame method signature matches the return type (tos).
1322// HandleMark must be defined in the caller only.
1323// It is to keep a ret_ob_h handle alive after return to the caller.
1324jvmtiError
1325JvmtiEnvBase::check_top_frame(JavaThread* current_thread, JavaThread* java_thread,
1326 jvalue value, TosState tos, Handle* ret_ob_h) {
1327 ResourceMark rm(current_thread);
1328
1329 vframe *vf = vframeFor(java_thread, 0);
1330 NULL_CHECK(vf, JVMTI_ERROR_NO_MORE_FRAMES);
1331
1332 javaVFrame *jvf = (javaVFrame*) vf;
1333 if (!vf->is_java_frame() || jvf->method()->is_native()) {
1334 return JVMTI_ERROR_OPAQUE_FRAME;
1335 }
1336
1337 // If the frame is a compiled one, need to deoptimize it.
1338 if (vf->is_compiled_frame()) {
1339 if (!vf->fr().can_be_deoptimized()) {
1340 return JVMTI_ERROR_OPAQUE_FRAME;
1341 }
1342 Deoptimization::deoptimize_frame(java_thread, jvf->fr().id());
1343 }
1344
1345 // Get information about method return type
1346 Symbol* signature = jvf->method()->signature();
1347
1348 ResultTypeFinder rtf(signature);
1349 TosState fr_tos = as_TosState(rtf.type());
1350 if (fr_tos != tos) {
1351 if (tos != itos || (fr_tos != btos && fr_tos != ztos && fr_tos != ctos && fr_tos != stos)) {
1352 return JVMTI_ERROR_TYPE_MISMATCH;
1353 }
1354 }
1355
1356 // Check that the jobject class matches the return type signature.
1357 jobject jobj = value.l;
1358 if (tos == atos && jobj != NULL) { // NULL reference is allowed
1359 Handle ob_h(current_thread, JNIHandles::resolve_external_guard(jobj));
1360 NULL_CHECK(ob_h, JVMTI_ERROR_INVALID_OBJECT);
1361 Klass* ob_k = ob_h()->klass();
1362 NULL_CHECK(ob_k, JVMTI_ERROR_INVALID_OBJECT);
1363
1364 // Method return type signature.
1365 char* ty_sign = 1 + strchr(signature->as_C_string(), ')');
1366
1367 if (!VM_GetOrSetLocal::is_assignable(ty_sign, ob_k, current_thread)) {
1368 return JVMTI_ERROR_TYPE_MISMATCH;
1369 }
1370 *ret_ob_h = ob_h;
1371 }
1372 return JVMTI_ERROR_NONE;
1373} /* end check_top_frame */
1374
1375
1376// ForceEarlyReturn<type> follows the PopFrame approach in many aspects.
1377// Main difference is on the last stage in the interpreter.
1378// The PopFrame stops method execution to continue execution
1379// from the same method call instruction.
1380// The ForceEarlyReturn forces return from method so the execution
1381// continues at the bytecode following the method call.
1382
1383// Threads_lock NOT held, java_thread not protected by lock
1384// java_thread - pre-checked
1385
1386jvmtiError
1387JvmtiEnvBase::force_early_return(JavaThread* java_thread, jvalue value, TosState tos) {
1388 JavaThread* current_thread = JavaThread::current();
1389 HandleMark hm(current_thread);
1390 uint32_t debug_bits = 0;
1391
1392 // retrieve or create the state
1393 JvmtiThreadState* state = JvmtiThreadState::state_for(java_thread);
1394 if (state == NULL) {
1395 return JVMTI_ERROR_THREAD_NOT_ALIVE;
1396 }
1397
1398 // Check if java_thread is fully suspended
1399 if (!java_thread->is_thread_fully_suspended(true /* wait for suspend completion */, &debug_bits)) {
1400 return JVMTI_ERROR_THREAD_NOT_SUSPENDED;
1401 }
1402
1403 // Check to see if a ForceEarlyReturn was already in progress
1404 if (state->is_earlyret_pending()) {
1405 // Probably possible for JVMTI clients to trigger this, but the
1406 // JPDA backend shouldn't allow this to happen
1407 return JVMTI_ERROR_INTERNAL;
1408 }
1409 {
1410 // The same as for PopFrame. Workaround bug:
1411 // 4812902: popFrame hangs if the method is waiting at a synchronize
1412 // Catch this condition and return an error to avoid hanging.
1413 // Now JVMTI spec allows an implementation to bail out with an opaque
1414 // frame error.
1415 OSThread* osThread = java_thread->osthread();
1416 if (osThread->get_state() == MONITOR_WAIT) {
1417 return JVMTI_ERROR_OPAQUE_FRAME;
1418 }
1419 }
1420 Handle ret_ob_h;
1421 jvmtiError err = check_top_frame(current_thread, java_thread, value, tos, &ret_ob_h);
1422 if (err != JVMTI_ERROR_NONE) {
1423 return err;
1424 }
1425 assert(tos != atos || value.l == NULL || ret_ob_h() != NULL,
1426 "return object oop must not be NULL if jobject is not NULL");
1427
1428 // Update the thread state to reflect that the top frame must be
1429 // forced to return.
1430 // The current frame will be returned later when the suspended
1431 // thread is resumed and right before returning from VM to Java.
1432 // (see call_VM_base() in assembler_<cpu>.cpp).
1433
1434 state->set_earlyret_pending();
1435 state->set_earlyret_oop(ret_ob_h());
1436 state->set_earlyret_value(value, tos);
1437
1438 // Set pending step flag for this early return.
1439 // It is cleared when next step event is posted.
1440 state->set_pending_step_for_earlyret();
1441
1442 return JVMTI_ERROR_NONE;
1443} /* end force_early_return */
1444
1445void
1446JvmtiMonitorClosure::do_monitor(ObjectMonitor* mon) {
1447 if ( _error != JVMTI_ERROR_NONE) {
1448 // Error occurred in previous iteration so no need to add
1449 // to the list.
1450 return;
1451 }
1452 if (mon->owner() == _java_thread ) {
1453 // Filter out on stack monitors collected during stack walk.
1454 oop obj = (oop)mon->object();
1455 bool found = false;
1456 for (int j = 0; j < _owned_monitors_list->length(); j++) {
1457 jobject jobj = ((jvmtiMonitorStackDepthInfo*)_owned_monitors_list->at(j))->monitor;
1458 oop check = JNIHandles::resolve(jobj);
1459 if (check == obj) {
1460 // On stack monitor already collected during the stack walk.
1461 found = true;
1462 break;
1463 }
1464 }
1465 if (found == false) {
1466 // This is off stack monitor (e.g. acquired via jni MonitorEnter).
1467 jvmtiError err;
1468 jvmtiMonitorStackDepthInfo *jmsdi;
1469 err = _env->allocate(sizeof(jvmtiMonitorStackDepthInfo), (unsigned char **)&jmsdi);
1470 if (err != JVMTI_ERROR_NONE) {
1471 _error = err;
1472 return;
1473 }
1474 Handle hobj(Thread::current(), obj);
1475 jmsdi->monitor = _env->jni_reference(_calling_thread, hobj);
1476 // stack depth is unknown for this monitor.
1477 jmsdi->stack_depth = -1;
1478 _owned_monitors_list->append(jmsdi);
1479 }
1480 }
1481}
1482
1483GrowableArray<OopHandle>* JvmtiModuleClosure::_tbl = NULL;
1484
1485void JvmtiModuleClosure::do_module(ModuleEntry* entry) {
1486 assert_locked_or_safepoint(Module_lock);
1487 OopHandle module = entry->module_handle();
1488 guarantee(module.resolve() != NULL, "module object is NULL");
1489 _tbl->push(module);
1490}
1491
1492jvmtiError
1493JvmtiModuleClosure::get_all_modules(JvmtiEnv* env, jint* module_count_ptr, jobject** modules_ptr) {
1494 ResourceMark rm;
1495 MutexLocker mcld(ClassLoaderDataGraph_lock);
1496 MutexLocker ml(Module_lock);
1497
1498 _tbl = new GrowableArray<OopHandle>(77);
1499 if (_tbl == NULL) {
1500 return JVMTI_ERROR_OUT_OF_MEMORY;
1501 }
1502
1503 // Iterate over all the modules loaded to the system.
1504 ClassLoaderDataGraph::modules_do(&do_module);
1505
1506 jint len = _tbl->length();
1507 guarantee(len > 0, "at least one module must be present");
1508
1509 jobject* array = (jobject*)env->jvmtiMalloc((jlong)(len * sizeof(jobject)));
1510 if (array == NULL) {
1511 return JVMTI_ERROR_OUT_OF_MEMORY;
1512 }
1513 for (jint idx = 0; idx < len; idx++) {
1514 array[idx] = JNIHandles::make_local(Thread::current(), _tbl->at(idx).resolve());
1515 }
1516 _tbl = NULL;
1517 *modules_ptr = array;
1518 *module_count_ptr = len;
1519 return JVMTI_ERROR_NONE;
1520}
1521
1522void
1523VM_UpdateForPopTopFrame::doit() {
1524 JavaThread* jt = _state->get_thread();
1525 ThreadsListHandle tlh;
1526 if (jt != NULL && tlh.includes(jt) && !jt->is_exiting() && jt->threadObj() != NULL) {
1527 _state->update_for_pop_top_frame();
1528 } else {
1529 _result = JVMTI_ERROR_THREAD_NOT_ALIVE;
1530 }
1531}
1532
1533void
1534VM_SetFramePop::doit() {
1535 JavaThread* jt = _state->get_thread();
1536 ThreadsListHandle tlh;
1537 if (jt != NULL && tlh.includes(jt) && !jt->is_exiting() && jt->threadObj() != NULL) {
1538 int frame_number = _state->count_frames() - _depth;
1539 _state->env_thread_state((JvmtiEnvBase*)_env)->set_frame_pop(frame_number);
1540 } else {
1541 _result = JVMTI_ERROR_THREAD_NOT_ALIVE;
1542 }
1543}
1544
1545void
1546VM_GetOwnedMonitorInfo::doit() {
1547 _result = JVMTI_ERROR_THREAD_NOT_ALIVE;
1548 ThreadsListHandle tlh;
1549 if (_java_thread != NULL && tlh.includes(_java_thread)
1550 && !_java_thread->is_exiting() && _java_thread->threadObj() != NULL) {
1551 _result = ((JvmtiEnvBase *)_env)->get_owned_monitors(_calling_thread, _java_thread,
1552 _owned_monitors_list);
1553 }
1554}
1555
1556void
1557VM_GetCurrentContendedMonitor::doit() {
1558 _result = JVMTI_ERROR_THREAD_NOT_ALIVE;
1559 ThreadsListHandle tlh;
1560 if (_java_thread != NULL && tlh.includes(_java_thread)
1561 && !_java_thread->is_exiting() && _java_thread->threadObj() != NULL) {
1562 _result = ((JvmtiEnvBase *)_env)->get_current_contended_monitor(_calling_thread,_java_thread,_owned_monitor_ptr);
1563 }
1564}
1565
1566void
1567VM_GetStackTrace::doit() {
1568 _result = JVMTI_ERROR_THREAD_NOT_ALIVE;
1569 ThreadsListHandle tlh;
1570 if (_java_thread != NULL && tlh.includes(_java_thread)
1571 && !_java_thread->is_exiting() && _java_thread->threadObj() != NULL) {
1572 _result = ((JvmtiEnvBase *)_env)->get_stack_trace(_java_thread,
1573 _start_depth, _max_count,
1574 _frame_buffer, _count_ptr);
1575 }
1576}
1577
1578void
1579VM_GetFrameCount::doit() {
1580 _result = JVMTI_ERROR_THREAD_NOT_ALIVE;
1581 JavaThread* jt = _state->get_thread();
1582 ThreadsListHandle tlh;
1583 if (jt != NULL && tlh.includes(jt) && !jt->is_exiting() && jt->threadObj() != NULL) {
1584 _result = ((JvmtiEnvBase*)_env)->get_frame_count(_state, _count_ptr);
1585 }
1586}
1587
1588void
1589VM_GetFrameLocation::doit() {
1590 _result = JVMTI_ERROR_THREAD_NOT_ALIVE;
1591 ThreadsListHandle tlh;
1592 if (_java_thread != NULL && tlh.includes(_java_thread)
1593 && !_java_thread->is_exiting() && _java_thread->threadObj() != NULL) {
1594 _result = ((JvmtiEnvBase*)_env)->get_frame_location(_java_thread, _depth,
1595 _method_ptr, _location_ptr);
1596 }
1597}
1598