1 /*
2 * Copyright (c) 2003, 2011, 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 "interpreter/interpreter.hpp"
28 #include "jvmtifiles/jvmtiEnv.hpp"
29 #include "memory/resourceArea.hpp"
30 #include "oops/instanceKlass.hpp"
31 #include "prims/jvmtiAgentThread.hpp"
32 #include "prims/jvmtiEventController.inline.hpp"
33 #include "prims/jvmtiImpl.hpp"
34 #include "prims/jvmtiRedefineClasses.hpp"
35 #include "runtime/atomic.hpp"
36 #include "runtime/deoptimization.hpp"
37 #include "runtime/handles.hpp"
38 #include "runtime/handles.inline.hpp"
39 #include "runtime/interfaceSupport.hpp"
40 #include "runtime/javaCalls.hpp"
41 #include "runtime/signature.hpp"
42 #include "runtime/vframe.hpp"
43 #include "runtime/vframe_hp.hpp"
44 #include "runtime/vm_operations.hpp"
45 #include "utilities/exceptions.hpp"
46 #ifdef TARGET_OS_FAMILY_linux
47 # include "thread_linux.inline.hpp"
48 #endif
49 #ifdef TARGET_OS_FAMILY_solaris
50 # include "thread_solaris.inline.hpp"
51 #endif
52 #ifdef TARGET_OS_FAMILY_windows
53 # include "thread_windows.inline.hpp"
54 #endif
55
56 //
57 // class JvmtiAgentThread
58 //
59 // JavaThread used to wrap a thread started by an agent
60 // using the JVMTI method RunAgentThread.
61 //
62
63 JvmtiAgentThread::JvmtiAgentThread(JvmtiEnv* env, jvmtiStartFunction start_fn, const void *start_arg)
64 : JavaThread(start_function_wrapper) {
65 _env = env;
66 _start_fn = start_fn;
67 _start_arg = start_arg;
68 }
69
70 void
71 JvmtiAgentThread::start_function_wrapper(JavaThread *thread, TRAPS) {
72 // It is expected that any Agent threads will be created as
73 // Java Threads. If this is the case, notification of the creation
74 // of the thread is given in JavaThread::thread_main().
75 assert(thread->is_Java_thread(), "debugger thread should be a Java Thread");
76 assert(thread == JavaThread::current(), "sanity check");
77
78 JvmtiAgentThread *dthread = (JvmtiAgentThread *)thread;
79 dthread->call_start_function();
80 }
81
82 void
83 JvmtiAgentThread::call_start_function() {
84 ThreadToNativeFromVM transition(this);
85 _start_fn(_env->jvmti_external(), jni_environment(), (void*)_start_arg);
86 }
87
88
89 //
90 // class GrowableCache - private methods
91 //
92
93 void GrowableCache::recache() {
94 int len = _elements->length();
95
96 FREE_C_HEAP_ARRAY(address, _cache);
97 _cache = NEW_C_HEAP_ARRAY(address,len+1);
98
99 for (int i=0; i<len; i++) {
100 _cache[i] = _elements->at(i)->getCacheValue();
101 //
102 // The cache entry has gone bad. Without a valid frame pointer
103 // value, the entry is useless so we simply delete it in product
104 // mode. The call to remove() will rebuild the cache again
105 // without the bad entry.
106 //
107 if (_cache[i] == NULL) {
108 assert(false, "cannot recache NULL elements");
109 remove(i);
110 return;
111 }
112 }
113 _cache[len] = NULL;
114
115 _listener_fun(_this_obj,_cache);
116 }
117
118 bool GrowableCache::equals(void* v, GrowableElement *e2) {
119 GrowableElement *e1 = (GrowableElement *) v;
120 assert(e1 != NULL, "e1 != NULL");
121 assert(e2 != NULL, "e2 != NULL");
122
123 return e1->equals(e2);
124 }
125
126 //
127 // class GrowableCache - public methods
128 //
129
130 GrowableCache::GrowableCache() {
131 _this_obj = NULL;
132 _listener_fun = NULL;
133 _elements = NULL;
134 _cache = NULL;
135 }
136
137 GrowableCache::~GrowableCache() {
138 clear();
139 delete _elements;
140 FREE_C_HEAP_ARRAY(address, _cache);
141 }
142
143 void GrowableCache::initialize(void *this_obj, void listener_fun(void *, address*) ) {
144 _this_obj = this_obj;
145 _listener_fun = listener_fun;
146 _elements = new (ResourceObj::C_HEAP) GrowableArray<GrowableElement*>(5,true);
147 recache();
148 }
149
150 // number of elements in the collection
151 int GrowableCache::length() {
152 return _elements->length();
153 }
154
155 // get the value of the index element in the collection
156 GrowableElement* GrowableCache::at(int index) {
157 GrowableElement *e = (GrowableElement *) _elements->at(index);
158 assert(e != NULL, "e != NULL");
159 return e;
160 }
161
162 int GrowableCache::find(GrowableElement* e) {
163 return _elements->find(e, GrowableCache::equals);
164 }
165
166 // append a copy of the element to the end of the collection
167 void GrowableCache::append(GrowableElement* e) {
168 GrowableElement *new_e = e->clone();
169 _elements->append(new_e);
170 recache();
171 }
172
173 // insert a copy of the element using lessthan()
174 void GrowableCache::insert(GrowableElement* e) {
175 GrowableElement *new_e = e->clone();
176 _elements->append(new_e);
177
178 int n = length()-2;
179 for (int i=n; i>=0; i--) {
180 GrowableElement *e1 = _elements->at(i);
181 GrowableElement *e2 = _elements->at(i+1);
182 if (e2->lessThan(e1)) {
183 _elements->at_put(i+1, e1);
184 _elements->at_put(i, e2);
185 }
186 }
187
188 recache();
189 }
190
191 // remove the element at index
192 void GrowableCache::remove (int index) {
193 GrowableElement *e = _elements->at(index);
194 assert(e != NULL, "e != NULL");
195 _elements->remove(e);
196 delete e;
197 recache();
198 }
199
200 // clear out all elements, release all heap space and
201 // let our listener know that things have changed.
202 void GrowableCache::clear() {
203 int len = _elements->length();
204 for (int i=0; i<len; i++) {
205 delete _elements->at(i);
206 }
207 _elements->clear();
208 recache();
209 }
210
211 void GrowableCache::oops_do(OopClosure* f) {
212 int len = _elements->length();
213 for (int i=0; i<len; i++) {
214 GrowableElement *e = _elements->at(i);
215 e->oops_do(f);
216 }
217 }
218
219 void GrowableCache::gc_epilogue() {
220 int len = _elements->length();
221 for (int i=0; i<len; i++) {
222 _cache[i] = _elements->at(i)->getCacheValue();
223 }
224 }
225
226 //
227 // class JvmtiBreakpoint
228 //
229
230 JvmtiBreakpoint::JvmtiBreakpoint() {
231 _method = NULL;
232 _bci = 0;
233 #ifdef CHECK_UNHANDLED_OOPS
234 // This one is always allocated with new, but check it just in case.
235 Thread *thread = Thread::current();
236 if (thread->is_in_stack((address)&_method)) {
237 thread->allow_unhandled_oop((oop*)&_method);
238 }
239 #endif // CHECK_UNHANDLED_OOPS
240 }
241
242 JvmtiBreakpoint::JvmtiBreakpoint(methodOop m_method, jlocation location) {
243 _method = m_method;
244 assert(_method != NULL, "_method != NULL");
245 _bci = (int) location;
246 #ifdef CHECK_UNHANDLED_OOPS
247 // Could be allocated with new and wouldn't be on the unhandled oop list.
248 Thread *thread = Thread::current();
249 if (thread->is_in_stack((address)&_method)) {
250 thread->allow_unhandled_oop(&_method);
251 }
252 #endif // CHECK_UNHANDLED_OOPS
253
254 assert(_bci >= 0, "_bci >= 0");
255 }
256
257 void JvmtiBreakpoint::copy(JvmtiBreakpoint& bp) {
258 _method = bp._method;
259 _bci = bp._bci;
260 }
261
262 bool JvmtiBreakpoint::lessThan(JvmtiBreakpoint& bp) {
263 Unimplemented();
264 return false;
265 }
266
267 bool JvmtiBreakpoint::equals(JvmtiBreakpoint& bp) {
268 return _method == bp._method
269 && _bci == bp._bci;
270 }
271
272 bool JvmtiBreakpoint::is_valid() {
273 return _method != NULL &&
274 _bci >= 0;
275 }
276
277 address JvmtiBreakpoint::getBcp() {
278 return _method->bcp_from(_bci);
279 }
280
281 void JvmtiBreakpoint::each_method_version_do(method_action meth_act) {
282 ((methodOopDesc*)_method->*meth_act)(_bci);
283
284 // add/remove breakpoint to/from versions of the method that
285 // are EMCP. Directly or transitively obsolete methods are
286 // not saved in the PreviousVersionInfo.
287 Thread *thread = Thread::current();
288 instanceKlassHandle ikh = instanceKlassHandle(thread, _method->method_holder());
289 symbolOop m_name = _method->name();
290 symbolOop m_signature = _method->signature();
291
292 {
293 ResourceMark rm(thread);
294 // PreviousVersionInfo objects returned via PreviousVersionWalker
295 // contain a GrowableArray of handles. We have to clean up the
296 // GrowableArray _after_ the PreviousVersionWalker destructor
297 // has destroyed the handles.
298 {
299 // search previous versions if they exist
300 PreviousVersionWalker pvw((instanceKlass *)ikh()->klass_part());
301 for (PreviousVersionInfo * pv_info = pvw.next_previous_version();
302 pv_info != NULL; pv_info = pvw.next_previous_version()) {
303 GrowableArray<methodHandle>* methods =
304 pv_info->prev_EMCP_method_handles();
305
306 if (methods == NULL) {
307 // We have run into a PreviousVersion generation where
308 // all methods were made obsolete during that generation's
309 // RedefineClasses() operation. At the time of that
310 // operation, all EMCP methods were flushed so we don't
311 // have to go back any further.
312 //
313 // A NULL methods array is different than an empty methods
314 // array. We cannot infer any optimizations about older
315 // generations from an empty methods array for the current
316 // generation.
317 break;
318 }
319
320 for (int i = methods->length() - 1; i >= 0; i--) {
321 methodHandle method = methods->at(i);
322 if (method->name() == m_name && method->signature() == m_signature) {
323 RC_TRACE(0x00000800, ("%sing breakpoint in %s(%s)",
324 meth_act == &methodOopDesc::set_breakpoint ? "sett" : "clear",
325 method->name()->as_C_string(),
326 method->signature()->as_C_string()));
327 assert(!method->is_obsolete(), "only EMCP methods here");
328
329 ((methodOopDesc*)method()->*meth_act)(_bci);
330 break;
331 }
332 }
333 }
334 } // pvw is cleaned up
335 } // rm is cleaned up
336 }
337
338 void JvmtiBreakpoint::set() {
339 each_method_version_do(&methodOopDesc::set_breakpoint);
340 }
341
342 void JvmtiBreakpoint::clear() {
343 each_method_version_do(&methodOopDesc::clear_breakpoint);
344 }
345
346 void JvmtiBreakpoint::print() {
347 #ifndef PRODUCT
348 const char *class_name = (_method == NULL) ? "NULL" : _method->klass_name()->as_C_string();
349 const char *method_name = (_method == NULL) ? "NULL" : _method->name()->as_C_string();
350
351 tty->print("Breakpoint(%s,%s,%d,%p)",class_name, method_name, _bci, getBcp());
352 #endif
353 }
354
355
356 //
357 // class VM_ChangeBreakpoints
358 //
359 // Modify the Breakpoints data structure at a safepoint
360 //
361
362 void VM_ChangeBreakpoints::doit() {
363 switch (_operation) {
364 case SET_BREAKPOINT:
365 _breakpoints->set_at_safepoint(*_bp);
366 break;
367 case CLEAR_BREAKPOINT:
368 _breakpoints->clear_at_safepoint(*_bp);
369 break;
370 case CLEAR_ALL_BREAKPOINT:
371 _breakpoints->clearall_at_safepoint();
372 break;
373 default:
374 assert(false, "Unknown operation");
375 }
376 }
377
378 void VM_ChangeBreakpoints::oops_do(OopClosure* f) {
379 // This operation keeps breakpoints alive
380 if (_breakpoints != NULL) {
381 _breakpoints->oops_do(f);
382 }
383 if (_bp != NULL) {
384 _bp->oops_do(f);
385 }
386 }
387
388 //
389 // class JvmtiBreakpoints
390 //
391 // a JVMTI internal collection of JvmtiBreakpoint
392 //
393
394 JvmtiBreakpoints::JvmtiBreakpoints(void listener_fun(void *,address *)) {
395 _bps.initialize(this,listener_fun);
396 }
397
398 JvmtiBreakpoints:: ~JvmtiBreakpoints() {}
399
400 void JvmtiBreakpoints::oops_do(OopClosure* f) {
401 _bps.oops_do(f);
402 }
403
404 void JvmtiBreakpoints::gc_epilogue() {
405 _bps.gc_epilogue();
406 }
407
408 void JvmtiBreakpoints::print() {
409 #ifndef PRODUCT
410 ResourceMark rm;
411
412 int n = _bps.length();
413 for (int i=0; i<n; i++) {
414 JvmtiBreakpoint& bp = _bps.at(i);
415 tty->print("%d: ", i);
416 bp.print();
417 tty->print_cr("");
418 }
419 #endif
420 }
421
422
423 void JvmtiBreakpoints::set_at_safepoint(JvmtiBreakpoint& bp) {
424 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
425
426 int i = _bps.find(bp);
427 if (i == -1) {
428 _bps.append(bp);
429 bp.set();
430 }
431 }
432
433 void JvmtiBreakpoints::clear_at_safepoint(JvmtiBreakpoint& bp) {
434 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
435
436 int i = _bps.find(bp);
437 if (i != -1) {
438 _bps.remove(i);
439 bp.clear();
440 }
441 }
442
443 void JvmtiBreakpoints::clearall_at_safepoint() {
444 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
445
446 int len = _bps.length();
447 for (int i=0; i<len; i++) {
448 _bps.at(i).clear();
449 }
450 _bps.clear();
451 }
452
453 int JvmtiBreakpoints::length() { return _bps.length(); }
454
455 int JvmtiBreakpoints::set(JvmtiBreakpoint& bp) {
456 if ( _bps.find(bp) != -1) {
457 return JVMTI_ERROR_DUPLICATE;
458 }
459 VM_ChangeBreakpoints set_breakpoint(this,VM_ChangeBreakpoints::SET_BREAKPOINT, &bp);
460 VMThread::execute(&set_breakpoint);
461 return JVMTI_ERROR_NONE;
462 }
463
464 int JvmtiBreakpoints::clear(JvmtiBreakpoint& bp) {
465 if ( _bps.find(bp) == -1) {
466 return JVMTI_ERROR_NOT_FOUND;
467 }
468
469 VM_ChangeBreakpoints clear_breakpoint(this,VM_ChangeBreakpoints::CLEAR_BREAKPOINT, &bp);
470 VMThread::execute(&clear_breakpoint);
471 return JVMTI_ERROR_NONE;
472 }
473
474 void JvmtiBreakpoints::clearall_in_class_at_safepoint(klassOop klass) {
475 bool changed = true;
476 // We are going to run thru the list of bkpts
477 // and delete some. This deletion probably alters
478 // the list in some implementation defined way such
479 // that when we delete entry i, the next entry might
480 // no longer be at i+1. To be safe, each time we delete
481 // an entry, we'll just start again from the beginning.
482 // We'll stop when we make a pass thru the whole list without
483 // deleting anything.
484 while (changed) {
485 int len = _bps.length();
486 changed = false;
487 for (int i = 0; i < len; i++) {
488 JvmtiBreakpoint& bp = _bps.at(i);
489 if (bp.method()->method_holder() == klass) {
490 bp.clear();
491 _bps.remove(i);
492 // This changed 'i' so we have to start over.
493 changed = true;
494 break;
495 }
496 }
497 }
498 }
499
500 void JvmtiBreakpoints::clearall() {
501 VM_ChangeBreakpoints clearall_breakpoint(this,VM_ChangeBreakpoints::CLEAR_ALL_BREAKPOINT);
502 VMThread::execute(&clearall_breakpoint);
503 }
504
505 //
506 // class JvmtiCurrentBreakpoints
507 //
508
509 JvmtiBreakpoints *JvmtiCurrentBreakpoints::_jvmti_breakpoints = NULL;
510 address * JvmtiCurrentBreakpoints::_breakpoint_list = NULL;
511
512
513 JvmtiBreakpoints& JvmtiCurrentBreakpoints::get_jvmti_breakpoints() {
514 if (_jvmti_breakpoints != NULL) return (*_jvmti_breakpoints);
515 _jvmti_breakpoints = new JvmtiBreakpoints(listener_fun);
516 assert(_jvmti_breakpoints != NULL, "_jvmti_breakpoints != NULL");
517 return (*_jvmti_breakpoints);
518 }
519
520 void JvmtiCurrentBreakpoints::listener_fun(void *this_obj, address *cache) {
521 JvmtiBreakpoints *this_jvmti = (JvmtiBreakpoints *) this_obj;
522 assert(this_jvmti != NULL, "this_jvmti != NULL");
523
524 debug_only(int n = this_jvmti->length(););
525 assert(cache[n] == NULL, "cache must be NULL terminated");
526
527 set_breakpoint_list(cache);
528 }
529
530
531 void JvmtiCurrentBreakpoints::oops_do(OopClosure* f) {
532 if (_jvmti_breakpoints != NULL) {
533 _jvmti_breakpoints->oops_do(f);
534 }
535 }
536
537 void JvmtiCurrentBreakpoints::gc_epilogue() {
538 if (_jvmti_breakpoints != NULL) {
539 _jvmti_breakpoints->gc_epilogue();
540 }
541 }
542
543 ///////////////////////////////////////////////////////////////
544 //
545 // class VM_GetOrSetLocal
546 //
547
548 // Constructor for non-object getter
549 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, jint depth, int index, BasicType type)
550 : _thread(thread)
551 , _calling_thread(NULL)
552 , _depth(depth)
553 , _index(index)
554 , _type(type)
555 , _set(false)
556 , _jvf(NULL)
557 , _result(JVMTI_ERROR_NONE)
558 {
559 }
560
561 // Constructor for object or non-object setter
562 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, jint depth, int index, BasicType type, jvalue value)
563 : _thread(thread)
564 , _calling_thread(NULL)
565 , _depth(depth)
566 , _index(index)
567 , _type(type)
568 , _value(value)
569 , _set(true)
570 , _jvf(NULL)
571 , _result(JVMTI_ERROR_NONE)
572 {
573 }
574
575 // Constructor for object getter
576 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, JavaThread* calling_thread, jint depth, int index)
577 : _thread(thread)
578 , _calling_thread(calling_thread)
579 , _depth(depth)
580 , _index(index)
581 , _type(T_OBJECT)
582 , _set(false)
583 , _jvf(NULL)
584 , _result(JVMTI_ERROR_NONE)
585 {
586 }
587
588 vframe *VM_GetOrSetLocal::get_vframe() {
589 if (!_thread->has_last_Java_frame()) {
590 return NULL;
591 }
592 RegisterMap reg_map(_thread);
593 vframe *vf = _thread->last_java_vframe(®_map);
594 int d = 0;
595 while ((vf != NULL) && (d < _depth)) {
596 vf = vf->java_sender();
597 d++;
598 }
599 return vf;
600 }
601
602 javaVFrame *VM_GetOrSetLocal::get_java_vframe() {
603 vframe* vf = get_vframe();
604 if (vf == NULL) {
605 _result = JVMTI_ERROR_NO_MORE_FRAMES;
606 return NULL;
607 }
608 javaVFrame *jvf = (javaVFrame*)vf;
609
610 if (!vf->is_java_frame()) {
611 _result = JVMTI_ERROR_OPAQUE_FRAME;
612 return NULL;
613 }
614 return jvf;
615 }
616
617 // Check that the klass is assignable to a type with the given signature.
618 // Another solution could be to use the function Klass::is_subtype_of(type).
619 // But the type class can be forced to load/initialize eagerly in such a case.
620 // This may cause unexpected consequences like CFLH or class-init JVMTI events.
621 // It is better to avoid such a behavior.
622 bool VM_GetOrSetLocal::is_assignable(const char* ty_sign, Klass* klass, Thread* thread) {
623 assert(ty_sign != NULL, "type signature must not be NULL");
624 assert(thread != NULL, "thread must not be NULL");
625 assert(klass != NULL, "klass must not be NULL");
626
627 int len = (int) strlen(ty_sign);
628 if (ty_sign[0] == 'L' && ty_sign[len-1] == ';') { // Need pure class/interface name
629 ty_sign++;
630 len -= 2;
631 }
632 symbolHandle ty_sym = oopFactory::new_symbol_handle(ty_sign, len, thread);
633 if (klass->name() == ty_sym()) {
634 return true;
635 }
636 // Compare primary supers
637 int super_depth = klass->super_depth();
638 int idx;
639 for (idx = 0; idx < super_depth; idx++) {
640 if (Klass::cast(klass->primary_super_of_depth(idx))->name() == ty_sym()) {
641 return true;
642 }
643 }
644 // Compare secondary supers
645 objArrayOop sec_supers = klass->secondary_supers();
646 for (idx = 0; idx < sec_supers->length(); idx++) {
647 if (Klass::cast((klassOop) sec_supers->obj_at(idx))->name() == ty_sym()) {
648 return true;
649 }
650 }
651 return false;
652 }
653
654 // Checks error conditions:
655 // JVMTI_ERROR_INVALID_SLOT
656 // JVMTI_ERROR_TYPE_MISMATCH
657 // Returns: 'true' - everything is Ok, 'false' - error code
658
659 bool VM_GetOrSetLocal::check_slot_type(javaVFrame* jvf) {
660 methodOop method_oop = jvf->method();
661 if (!method_oop->has_localvariable_table()) {
662 // Just to check index boundaries
663 jint extra_slot = (_type == T_LONG || _type == T_DOUBLE) ? 1 : 0;
664 if (_index < 0 || _index + extra_slot >= method_oop->max_locals()) {
665 _result = JVMTI_ERROR_INVALID_SLOT;
666 return false;
667 }
668 return true;
669 }
670
671 jint num_entries = method_oop->localvariable_table_length();
672 if (num_entries == 0) {
673 _result = JVMTI_ERROR_INVALID_SLOT;
674 return false; // There are no slots
675 }
676 int signature_idx = -1;
677 int vf_bci = jvf->bci();
678 LocalVariableTableElement* table = method_oop->localvariable_table_start();
679 for (int i = 0; i < num_entries; i++) {
680 int start_bci = table[i].start_bci;
681 int end_bci = start_bci + table[i].length;
682
683 // Here we assume that locations of LVT entries
684 // with the same slot number cannot be overlapped
685 if (_index == (jint) table[i].slot && start_bci <= vf_bci && vf_bci <= end_bci) {
686 signature_idx = (int) table[i].descriptor_cp_index;
687 break;
688 }
689 }
690 if (signature_idx == -1) {
691 _result = JVMTI_ERROR_INVALID_SLOT;
692 return false; // Incorrect slot index
693 }
694 symbolOop sign_sym = method_oop->constants()->symbol_at(signature_idx);
695 const char* signature = (const char *) sign_sym->as_utf8();
696 BasicType slot_type = char2type(signature[0]);
697
698 switch (slot_type) {
699 case T_BYTE:
700 case T_SHORT:
701 case T_CHAR:
702 case T_BOOLEAN:
703 slot_type = T_INT;
704 break;
705 case T_ARRAY:
706 slot_type = T_OBJECT;
707 break;
708 };
709 if (_type != slot_type) {
710 _result = JVMTI_ERROR_TYPE_MISMATCH;
711 return false;
712 }
713
714 jobject jobj = _value.l;
715 if (_set && slot_type == T_OBJECT && jobj != NULL) { // NULL reference is allowed
716 // Check that the jobject class matches the return type signature.
717 JavaThread* cur_thread = JavaThread::current();
718 HandleMark hm(cur_thread);
719
720 Handle obj = Handle(cur_thread, JNIHandles::resolve_external_guard(jobj));
721 NULL_CHECK(obj, (_result = JVMTI_ERROR_INVALID_OBJECT, false));
722 KlassHandle ob_kh = KlassHandle(cur_thread, obj->klass());
723 NULL_CHECK(ob_kh, (_result = JVMTI_ERROR_INVALID_OBJECT, false));
724
725 if (!is_assignable(signature, Klass::cast(ob_kh()), cur_thread)) {
726 _result = JVMTI_ERROR_TYPE_MISMATCH;
727 return false;
728 }
729 }
730 return true;
731 }
732
733 static bool can_be_deoptimized(vframe* vf) {
734 return (vf->is_compiled_frame() && vf->fr().can_be_deoptimized());
735 }
736
737 bool VM_GetOrSetLocal::doit_prologue() {
738 _jvf = get_java_vframe();
739 NULL_CHECK(_jvf, false);
740
741 if (_jvf->method()->is_native()) {
742 if (getting_receiver() && !_jvf->method()->is_static()) {
743 return true;
744 } else {
745 _result = JVMTI_ERROR_OPAQUE_FRAME;
746 return false;
747 }
748 }
749
750 if (!check_slot_type(_jvf)) {
751 return false;
752 }
753 return true;
754 }
755
756 void VM_GetOrSetLocal::doit() {
757 if (_set) {
758 // Force deoptimization of frame if compiled because it's
759 // possible the compiler emitted some locals as constant values,
760 // meaning they are not mutable.
761 if (can_be_deoptimized(_jvf)) {
762
763 // Schedule deoptimization so that eventually the local
764 // update will be written to an interpreter frame.
765 Deoptimization::deoptimize_frame(_jvf->thread(), _jvf->fr().id());
766
767 // Now store a new value for the local which will be applied
768 // once deoptimization occurs. Note however that while this
769 // write is deferred until deoptimization actually happens
770 // can vframe created after this point will have its locals
771 // reflecting this update so as far as anyone can see the
772 // write has already taken place.
773
774 // If we are updating an oop then get the oop from the handle
775 // since the handle will be long gone by the time the deopt
776 // happens. The oop stored in the deferred local will be
777 // gc'd on its own.
778 if (_type == T_OBJECT) {
779 _value.l = (jobject) (JNIHandles::resolve_external_guard(_value.l));
780 }
781 // Re-read the vframe so we can see that it is deoptimized
782 // [ Only need because of assert in update_local() ]
783 _jvf = get_java_vframe();
784 ((compiledVFrame*)_jvf)->update_local(_type, _index, _value);
785 return;
786 }
787 StackValueCollection *locals = _jvf->locals();
788 HandleMark hm;
789
790 switch (_type) {
791 case T_INT: locals->set_int_at (_index, _value.i); break;
792 case T_LONG: locals->set_long_at (_index, _value.j); break;
793 case T_FLOAT: locals->set_float_at (_index, _value.f); break;
794 case T_DOUBLE: locals->set_double_at(_index, _value.d); break;
795 case T_OBJECT: {
796 Handle ob_h(JNIHandles::resolve_external_guard(_value.l));
797 locals->set_obj_at (_index, ob_h);
798 break;
799 }
800 default: ShouldNotReachHere();
801 }
802 _jvf->set_locals(locals);
803 } else {
804 if (_jvf->method()->is_native() && _jvf->is_compiled_frame()) {
805 assert(getting_receiver(), "Can only get here when getting receiver");
806 oop receiver = _jvf->fr().get_native_receiver();
807 _value.l = JNIHandles::make_local(_calling_thread, receiver);
808 } else {
809 StackValueCollection *locals = _jvf->locals();
810
811 if (locals->at(_index)->type() == T_CONFLICT) {
812 memset(&_value, 0, sizeof(_value));
813 _value.l = NULL;
814 return;
815 }
816
817 switch (_type) {
818 case T_INT: _value.i = locals->int_at (_index); break;
819 case T_LONG: _value.j = locals->long_at (_index); break;
820 case T_FLOAT: _value.f = locals->float_at (_index); break;
821 case T_DOUBLE: _value.d = locals->double_at(_index); break;
822 case T_OBJECT: {
823 // Wrap the oop to be returned in a local JNI handle since
824 // oops_do() no longer applies after doit() is finished.
825 oop obj = locals->obj_at(_index)();
826 _value.l = JNIHandles::make_local(_calling_thread, obj);
827 break;
828 }
829 default: ShouldNotReachHere();
830 }
831 }
832 }
833 }
834
835
836 bool VM_GetOrSetLocal::allow_nested_vm_operations() const {
837 return true; // May need to deoptimize
838 }
839
840
841 VM_GetReceiver::VM_GetReceiver(
842 JavaThread* thread, JavaThread* caller_thread, jint depth)
843 : VM_GetOrSetLocal(thread, caller_thread, depth, 0) {}
844
845 /////////////////////////////////////////////////////////////////////////////////////////
846
847 //
848 // class JvmtiSuspendControl - see comments in jvmtiImpl.hpp
849 //
850
851 bool JvmtiSuspendControl::suspend(JavaThread *java_thread) {
852 // external suspend should have caught suspending a thread twice
853
854 // Immediate suspension required for JPDA back-end so JVMTI agent threads do
855 // not deadlock due to later suspension on transitions while holding
856 // raw monitors. Passing true causes the immediate suspension.
857 // java_suspend() will catch threads in the process of exiting
858 // and will ignore them.
859 java_thread->java_suspend();
860
861 // It would be nice to have the following assertion in all the time,
862 // but it is possible for a racing resume request to have resumed
863 // this thread right after we suspended it. Temporarily enable this
864 // assertion if you are chasing a different kind of bug.
865 //
866 // assert(java_lang_Thread::thread(java_thread->threadObj()) == NULL ||
867 // java_thread->is_being_ext_suspended(), "thread is not suspended");
868
869 if (java_lang_Thread::thread(java_thread->threadObj()) == NULL) {
870 // check again because we can get delayed in java_suspend():
871 // the thread is in process of exiting.
872 return false;
873 }
874
875 return true;
876 }
877
878 bool JvmtiSuspendControl::resume(JavaThread *java_thread) {
879 // external suspend should have caught resuming a thread twice
880 assert(java_thread->is_being_ext_suspended(), "thread should be suspended");
881
882 // resume thread
883 {
884 // must always grab Threads_lock, see JVM_SuspendThread
885 MutexLocker ml(Threads_lock);
886 java_thread->java_resume();
887 }
888
889 return true;
890 }
891
892
893 void JvmtiSuspendControl::print() {
894 #ifndef PRODUCT
895 MutexLocker mu(Threads_lock);
896 ResourceMark rm;
897
898 tty->print("Suspended Threads: [");
899 for (JavaThread *thread = Threads::first(); thread != NULL; thread = thread->next()) {
900 #if JVMTI_TRACE
901 const char *name = JvmtiTrace::safe_get_thread_name(thread);
902 #else
903 const char *name = "";
904 #endif /*JVMTI_TRACE */
905 tty->print("%s(%c ", name, thread->is_being_ext_suspended() ? 'S' : '_');
906 if (!thread->has_last_Java_frame()) {
907 tty->print("no stack");
908 }
909 tty->print(") ");
910 }
911 tty->print_cr("]");
912 #endif
913 }
914
915 #ifndef KERNEL
916
917 JvmtiDeferredEvent JvmtiDeferredEvent::compiled_method_loaded_event(
918 nmethod* nm) {
919 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_COMPILED_METHOD_LOADED);
920 event.set_compiled_method_loaded(nm);
921 nmethodLocker::lock_nmethod(nm); // will be unlocked when posted
922 return event;
923 }
924
925 JvmtiDeferredEvent JvmtiDeferredEvent::compiled_method_unloaded_event(
926 jmethodID id, const void* code) {
927 JvmtiDeferredEvent event =
928 JvmtiDeferredEvent(TYPE_COMPILED_METHOD_UNLOADED);
929 event.set_compiled_method_unloaded(id, code);
930 return event;
931 }
932
933 void JvmtiDeferredEvent::post() {
934 switch(_type) {
935 case TYPE_COMPILED_METHOD_LOADED:
936 JvmtiExport::post_compiled_method_load(compiled_method_loaded());
937 nmethodLocker::unlock_nmethod(compiled_method_loaded());
938 break;
939 case TYPE_COMPILED_METHOD_UNLOADED:
940 JvmtiExport::post_compiled_method_unload(
941 compiled_method_unloaded_method_id(),
942 compiled_method_unloaded_code_begin());
943 break;
944 default:
945 ShouldNotReachHere();
946 }
947 }
948
949 JvmtiDeferredEventQueue::QueueNode* JvmtiDeferredEventQueue::_queue_tail = NULL;
950 JvmtiDeferredEventQueue::QueueNode* JvmtiDeferredEventQueue::_queue_head = NULL;
951
952 volatile JvmtiDeferredEventQueue::QueueNode*
953 JvmtiDeferredEventQueue::_pending_list = NULL;
954
955 bool JvmtiDeferredEventQueue::has_events() {
956 assert(Service_lock->owned_by_self(), "Must own Service_lock");
957 process_pending_events();
958 return _queue_head != NULL;
959 }
960
961 void JvmtiDeferredEventQueue::enqueue(const JvmtiDeferredEvent& event) {
962 assert(Service_lock->owned_by_self(), "Must own Service_lock");
963
964 process_pending_events();
965
966 // Events get added to the beginning of the queue
967 QueueNode* node = new QueueNode(event);
968 if (_queue_tail == NULL) {
969 _queue_tail = _queue_head = node;
970 } else {
971 assert(_queue_tail->next() == NULL, "Must be the last element in the list");
972 _queue_tail->set_next(node);
973 _queue_tail = node;
974 }
975
976 Service_lock->notify_all();
977 assert((_queue_head == NULL) == (_queue_tail == NULL),
978 "Inconsistent queue markers");
979 }
980
981 JvmtiDeferredEvent JvmtiDeferredEventQueue::dequeue() {
982 assert(Service_lock->owned_by_self(), "Must own Service_lock");
983
984 process_pending_events();
985
986 assert(_queue_head != NULL, "Nothing to dequeue");
987
988 if (_queue_head == NULL) {
989 // Just in case this happens in product; it shouldn't be let's not crash
990 return JvmtiDeferredEvent();
991 }
992
993 QueueNode* node = _queue_head;
994 _queue_head = _queue_head->next();
995 if (_queue_head == NULL) {
996 _queue_tail = NULL;
997 }
998
999 assert((_queue_head == NULL) == (_queue_tail == NULL),
1000 "Inconsistent queue markers");
1001
1002 JvmtiDeferredEvent event = node->event();
1003 delete node;
1004 return event;
1005 }
1006
1007 void JvmtiDeferredEventQueue::add_pending_event(
1008 const JvmtiDeferredEvent& event) {
1009
1010 QueueNode* node = new QueueNode(event);
1011
1012 while (true) {
1013 node->set_next((QueueNode*)_pending_list);
1014 QueueNode* old_value = (QueueNode*)Atomic::cmpxchg_ptr(
1015 (void*)node, (volatile void*)&_pending_list, node->next());
1016 if (old_value == node->next()) {
1017 break;
1018 }
1019 }
1020 }
1021
1022 // This method transfers any events that were added by someone NOT holding
1023 // the lock into the mainline queue.
1024 void JvmtiDeferredEventQueue::process_pending_events() {
1025 assert(Service_lock->owned_by_self(), "Must own Service_lock");
1026
1027 if (_pending_list != NULL) {
1028 QueueNode* head;
1029 while (true) {
1030 head = (QueueNode*)_pending_list;
1031 QueueNode* old_value = (QueueNode*)Atomic::cmpxchg_ptr(
1032 NULL, (volatile void*)&_pending_list, (void*)head);
1033 if (old_value == head) {
1034 break;
1035 }
1036 }
1037
1038 assert((_queue_head == NULL) == (_queue_tail == NULL),
1039 "Inconsistent queue markers");
1040
1041 if (head != NULL) {
1042 // Since we've treated the pending list as a stack (with newer
1043 // events at the beginning), we need to join the bottom of the stack
1044 // with the 'tail' of the queue in order to get the events in the
1045 // right order. We do this by reversing the pending list and appending
1046 // it to the queue.
1047
1048 QueueNode* new_tail = head;
1049 QueueNode* new_head = NULL;
1050
1051 // This reverses the list
1052 QueueNode* prev = new_tail;
1053 QueueNode* node = new_tail->next();
1054 new_tail->set_next(NULL);
1055 while (node != NULL) {
1056 QueueNode* next = node->next();
1057 node->set_next(prev);
1058 prev = node;
1059 node = next;
1060 }
1061 new_head = prev;
1062
1063 // Now append the new list to the queue
1064 if (_queue_tail != NULL) {
1065 _queue_tail->set_next(new_head);
1066 } else { // _queue_head == NULL
1067 _queue_head = new_head;
1068 }
1069 _queue_tail = new_tail;
1070
1071 Service_lock->notify_all();
1072 }
1073 }
1074 }
1075
1076 void JvmtiDeferredEventQueue::wait_for_empty_queue() {
1077 MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag);
1078 while (has_events()) {
1079 Service_lock->notify_all();
1080 Service_lock->wait(Mutex::_no_safepoint_check_flag);
1081 }
1082 }
1083
1084 void JvmtiDeferredEventQueue::notify_empty_queue() {
1085 assert(Service_lock->owned_by_self(), "Must own Service_lock");
1086 Service_lock->notify_all();
1087 }
1088
1089 #endif // ndef KERNEL