1 /*
2 * Copyright (c) 2003, 2010, 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/handles.hpp"
36 #include "runtime/handles.inline.hpp"
37 #include "runtime/interfaceSupport.hpp"
38 #include "runtime/javaCalls.hpp"
39 #include "runtime/signature.hpp"
40 #include "runtime/vframe.hpp"
41 #include "runtime/vframe_hp.hpp"
42 #include "runtime/vm_operations.hpp"
43 #include "utilities/exceptions.hpp"
44 #ifdef TARGET_OS_FAMILY_linux
45 # include "thread_linux.inline.hpp"
46 #endif
47 #ifdef TARGET_OS_FAMILY_solaris
48 # include "thread_solaris.inline.hpp"
49 #endif
50 #ifdef TARGET_OS_FAMILY_windows
51 # include "thread_windows.inline.hpp"
52 #endif
53
54 //
55 // class JvmtiAgentThread
56 //
57 // JavaThread used to wrap a thread started by an agent
58 // using the JVMTI method RunAgentThread.
59 //
60
61 JvmtiAgentThread::JvmtiAgentThread(JvmtiEnv* env, jvmtiStartFunction start_fn, const void *start_arg)
62 : JavaThread(start_function_wrapper) {
63 _env = env;
64 _start_fn = start_fn;
65 _start_arg = start_arg;
66 }
67
68 void
69 JvmtiAgentThread::start_function_wrapper(JavaThread *thread, TRAPS) {
70 // It is expected that any Agent threads will be created as
71 // Java Threads. If this is the case, notification of the creation
72 // of the thread is given in JavaThread::thread_main().
73 assert(thread->is_Java_thread(), "debugger thread should be a Java Thread");
74 assert(thread == JavaThread::current(), "sanity check");
75
76 JvmtiAgentThread *dthread = (JvmtiAgentThread *)thread;
77 dthread->call_start_function();
78 }
79
80 void
81 JvmtiAgentThread::call_start_function() {
82 ThreadToNativeFromVM transition(this);
83 _start_fn(_env->jvmti_external(), jni_environment(), (void*)_start_arg);
84 }
85
86
87 //
88 // class GrowableCache - private methods
89 //
90
91 void GrowableCache::recache() {
92 int len = _elements->length();
93
94 FREE_C_HEAP_ARRAY(address, _cache);
95 _cache = NEW_C_HEAP_ARRAY(address,len+1);
96
97 for (int i=0; i<len; i++) {
98 _cache[i] = _elements->at(i)->getCacheValue();
99 //
100 // The cache entry has gone bad. Without a valid frame pointer
101 // value, the entry is useless so we simply delete it in product
102 // mode. The call to remove() will rebuild the cache again
103 // without the bad entry.
104 //
105 if (_cache[i] == NULL) {
106 assert(false, "cannot recache NULL elements");
107 remove(i);
108 return;
109 }
110 }
111 _cache[len] = NULL;
112
113 _listener_fun(_this_obj,_cache);
114 }
115
116 bool GrowableCache::equals(void* v, GrowableElement *e2) {
117 GrowableElement *e1 = (GrowableElement *) v;
118 assert(e1 != NULL, "e1 != NULL");
119 assert(e2 != NULL, "e2 != NULL");
120
121 return e1->equals(e2);
122 }
123
124 //
125 // class GrowableCache - public methods
126 //
127
128 GrowableCache::GrowableCache() {
129 _this_obj = NULL;
130 _listener_fun = NULL;
131 _elements = NULL;
132 _cache = NULL;
133 }
134
135 GrowableCache::~GrowableCache() {
136 clear();
137 delete _elements;
138 FREE_C_HEAP_ARRAY(address, _cache);
139 }
140
141 void GrowableCache::initialize(void *this_obj, void listener_fun(void *, address*) ) {
142 _this_obj = this_obj;
143 _listener_fun = listener_fun;
144 _elements = new (ResourceObj::C_HEAP) GrowableArray<GrowableElement*>(5,true);
145 recache();
146 }
147
148 // number of elements in the collection
149 int GrowableCache::length() {
150 return _elements->length();
151 }
152
153 // get the value of the index element in the collection
154 GrowableElement* GrowableCache::at(int index) {
155 GrowableElement *e = (GrowableElement *) _elements->at(index);
156 assert(e != NULL, "e != NULL");
157 return e;
158 }
159
160 int GrowableCache::find(GrowableElement* e) {
161 return _elements->find(e, GrowableCache::equals);
162 }
163
164 // append a copy of the element to the end of the collection
165 void GrowableCache::append(GrowableElement* e) {
166 GrowableElement *new_e = e->clone();
167 _elements->append(new_e);
168 recache();
169 }
170
171 // insert a copy of the element using lessthan()
172 void GrowableCache::insert(GrowableElement* e) {
173 GrowableElement *new_e = e->clone();
174 _elements->append(new_e);
175
176 int n = length()-2;
177 for (int i=n; i>=0; i--) {
178 GrowableElement *e1 = _elements->at(i);
179 GrowableElement *e2 = _elements->at(i+1);
180 if (e2->lessThan(e1)) {
181 _elements->at_put(i+1, e1);
182 _elements->at_put(i, e2);
183 }
184 }
185
186 recache();
187 }
188
189 // remove the element at index
190 void GrowableCache::remove (int index) {
191 GrowableElement *e = _elements->at(index);
192 assert(e != NULL, "e != NULL");
193 _elements->remove(e);
194 delete e;
195 recache();
196 }
197
198 // clear out all elements, release all heap space and
199 // let our listener know that things have changed.
200 void GrowableCache::clear() {
201 int len = _elements->length();
202 for (int i=0; i<len; i++) {
203 delete _elements->at(i);
204 }
205 _elements->clear();
206 recache();
207 }
208
209 void GrowableCache::oops_do(OopClosure* f) {
210 int len = _elements->length();
211 for (int i=0; i<len; i++) {
212 GrowableElement *e = _elements->at(i);
213 e->oops_do(f);
214 }
215 }
216
217 void GrowableCache::gc_epilogue() {
218 int len = _elements->length();
219 // recompute the new cache value after GC
220 for (int i=0; i<len; i++) {
221 _cache[i] = _elements->at(i)->getCacheValue();
222 }
223 }
224
225 //
226 // class JvmtiBreakpoint
227 //
228
229 JvmtiBreakpoint::JvmtiBreakpoint() {
230 _method = NULL;
231 _bci = 0;
232 #ifdef CHECK_UNHANDLED_OOPS
233 // This one is always allocated with new, but check it just in case.
234 Thread *thread = Thread::current();
235 if (thread->is_in_stack((address)&_method)) {
236 thread->allow_unhandled_oop((oop*)&_method);
237 }
238 #endif // CHECK_UNHANDLED_OOPS
239 }
240
241 JvmtiBreakpoint::JvmtiBreakpoint(methodOop m_method, jlocation location) {
242 _method = m_method;
243 assert(_method != NULL, "_method != NULL");
244 _bci = (int) location;
245 #ifdef CHECK_UNHANDLED_OOPS
246 // Could be allocated with new and wouldn't be on the unhandled oop list.
247 Thread *thread = Thread::current();
248 if (thread->is_in_stack((address)&_method)) {
249 thread->allow_unhandled_oop(&_method);
250 }
251 #endif // CHECK_UNHANDLED_OOPS
252
253 assert(_bci >= 0, "_bci >= 0");
254 }
255
256 void JvmtiBreakpoint::copy(JvmtiBreakpoint& bp) {
257 _method = bp._method;
258 _bci = bp._bci;
259 }
260
261 bool JvmtiBreakpoint::lessThan(JvmtiBreakpoint& bp) {
262 Unimplemented();
263 return false;
264 }
265
266 bool JvmtiBreakpoint::equals(JvmtiBreakpoint& bp) {
267 return _method == bp._method
268 && _bci == bp._bci;
269 }
270
271 bool JvmtiBreakpoint::is_valid() {
272 return _method != NULL &&
273 _bci >= 0;
274 }
275
276 address JvmtiBreakpoint::getBcp() {
277 return _method->bcp_from(_bci);
278 }
279
280 void JvmtiBreakpoint::each_method_version_do(method_action meth_act) {
281 ((methodOopDesc*)_method->*meth_act)(_bci);
282
283 // add/remove breakpoint to/from versions of the method that
284 // are EMCP. Directly or transitively obsolete methods are
285 // not saved in the PreviousVersionInfo.
286 Thread *thread = Thread::current();
287 instanceKlassHandle ikh = instanceKlassHandle(thread, _method->method_holder());
288 symbolOop m_name = _method->name();
289 symbolOop m_signature = _method->signature();
290
291 {
292 ResourceMark rm(thread);
293 // PreviousVersionInfo objects returned via PreviousVersionWalker
294 // contain a GrowableArray of handles. We have to clean up the
295 // GrowableArray _after_ the PreviousVersionWalker destructor
296 // has destroyed the handles.
297 {
298 // search previous versions if they exist
299 PreviousVersionWalker pvw((instanceKlass *)ikh()->klass_part());
300 for (PreviousVersionInfo * pv_info = pvw.next_previous_version();
301 pv_info != NULL; pv_info = pvw.next_previous_version()) {
302 GrowableArray<methodHandle>* methods =
303 pv_info->prev_EMCP_method_handles();
304
305 if (methods == NULL) {
306 // We have run into a PreviousVersion generation where
307 // all methods were made obsolete during that generation's
308 // RedefineClasses() operation. At the time of that
309 // operation, all EMCP methods were flushed so we don't
310 // have to go back any further.
311 //
312 // A NULL methods array is different than an empty methods
313 // array. We cannot infer any optimizations about older
314 // generations from an empty methods array for the current
315 // generation.
316 break;
317 }
318
319 for (int i = methods->length() - 1; i >= 0; i--) {
320 methodHandle method = methods->at(i);
321 if (method->name() == m_name && method->signature() == m_signature) {
322 RC_TRACE(0x00000800, ("%sing breakpoint in %s(%s)",
323 meth_act == &methodOopDesc::set_breakpoint ? "sett" : "clear",
324 method->name()->as_C_string(),
325 method->signature()->as_C_string()));
326 assert(!method->is_obsolete(), "only EMCP methods here");
327
328 ((methodOopDesc*)method()->*meth_act)(_bci);
329 break;
330 }
331 }
332 }
333 } // pvw is cleaned up
334 } // rm is cleaned up
335 }
336
337 void JvmtiBreakpoint::set() {
338 each_method_version_do(&methodOopDesc::set_breakpoint);
339 }
340
341 void JvmtiBreakpoint::clear() {
342 each_method_version_do(&methodOopDesc::clear_breakpoint);
343 }
344
345 void JvmtiBreakpoint::print() {
346 #ifndef PRODUCT
347 const char *class_name = (_method == NULL) ? "NULL" : _method->klass_name()->as_C_string();
348 const char *method_name = (_method == NULL) ? "NULL" : _method->name()->as_C_string();
349
350 tty->print("Breakpoint(%s,%s,%d,%p)",class_name, method_name, _bci, getBcp());
351 #endif
352 }
353
354
355 //
356 // class VM_ChangeBreakpoints
357 //
358 // Modify the Breakpoints data structure at a safepoint
359 //
360
361 void VM_ChangeBreakpoints::doit() {
362 switch (_operation) {
363 case SET_BREAKPOINT:
364 _breakpoints->set_at_safepoint(*_bp);
365 break;
366 case CLEAR_BREAKPOINT:
367 _breakpoints->clear_at_safepoint(*_bp);
368 break;
369 case CLEAR_ALL_BREAKPOINT:
370 _breakpoints->clearall_at_safepoint();
371 break;
372 default:
373 assert(false, "Unknown operation");
374 }
375 }
376
377 void VM_ChangeBreakpoints::oops_do(OopClosure* f) {
378 // This operation keeps breakpoints alive
379 if (_breakpoints != NULL) {
380 _breakpoints->oops_do(f);
381 }
382 if (_bp != NULL) {
383 _bp->oops_do(f);
384 }
385 }
386
387 //
388 // class JvmtiBreakpoints
389 //
390 // a JVMTI internal collection of JvmtiBreakpoint
391 //
392
393 JvmtiBreakpoints::JvmtiBreakpoints(void listener_fun(void *,address *)) {
394 _bps.initialize(this,listener_fun);
395 }
396
397 JvmtiBreakpoints:: ~JvmtiBreakpoints() {}
398
399 void JvmtiBreakpoints::oops_do(OopClosure* f) {
400 _bps.oops_do(f);
401 }
402
403 void JvmtiBreakpoints::gc_epilogue() {
404 _bps.gc_epilogue();
405 }
406
407 void JvmtiBreakpoints::print() {
408 #ifndef PRODUCT
409 ResourceMark rm;
410
411 int n = _bps.length();
412 for (int i=0; i<n; i++) {
413 JvmtiBreakpoint& bp = _bps.at(i);
414 tty->print("%d: ", i);
415 bp.print();
416 tty->print_cr("");
417 }
418 #endif
419 }
420
421
422 void JvmtiBreakpoints::set_at_safepoint(JvmtiBreakpoint& bp) {
423 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
424
425 int i = _bps.find(bp);
426 if (i == -1) {
427 _bps.append(bp);
428 bp.set();
429 }
430 }
431
432 void JvmtiBreakpoints::clear_at_safepoint(JvmtiBreakpoint& bp) {
433 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
434
435 int i = _bps.find(bp);
436 if (i != -1) {
437 _bps.remove(i);
438 bp.clear();
439 }
440 }
441
442 void JvmtiBreakpoints::clearall_at_safepoint() {
443 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
444
445 int len = _bps.length();
446 for (int i=0; i<len; i++) {
447 _bps.at(i).clear();
448 }
449 _bps.clear();
450 }
451
452 int JvmtiBreakpoints::length() { return _bps.length(); }
453
454 int JvmtiBreakpoints::set(JvmtiBreakpoint& bp) {
455 if ( _bps.find(bp) != -1) {
456 return JVMTI_ERROR_DUPLICATE;
457 }
458 VM_ChangeBreakpoints set_breakpoint(this,VM_ChangeBreakpoints::SET_BREAKPOINT, &bp);
459 VMThread::execute(&set_breakpoint);
460 return JVMTI_ERROR_NONE;
461 }
462
463 int JvmtiBreakpoints::clear(JvmtiBreakpoint& bp) {
464 if ( _bps.find(bp) == -1) {
465 return JVMTI_ERROR_NOT_FOUND;
466 }
467
468 VM_ChangeBreakpoints clear_breakpoint(this,VM_ChangeBreakpoints::CLEAR_BREAKPOINT, &bp);
469 VMThread::execute(&clear_breakpoint);
470 return JVMTI_ERROR_NONE;
471 }
472
473 void JvmtiBreakpoints::clearall_in_class_at_safepoint(klassOop klass) {
474 bool changed = true;
475 // We are going to run thru the list of bkpts
476 // and delete some. This deletion probably alters
477 // the list in some implementation defined way such
478 // that when we delete entry i, the next entry might
479 // no longer be at i+1. To be safe, each time we delete
480 // an entry, we'll just start again from the beginning.
481 // We'll stop when we make a pass thru the whole list without
482 // deleting anything.
483 while (changed) {
484 int len = _bps.length();
485 changed = false;
486 for (int i = 0; i < len; i++) {
487 JvmtiBreakpoint& bp = _bps.at(i);
488 if (bp.method()->method_holder() == klass) {
489 bp.clear();
490 _bps.remove(i);
491 // This changed 'i' so we have to start over.
492 changed = true;
493 break;
494 }
495 }
496 }
497 }
498
499 void JvmtiBreakpoints::clearall() {
500 VM_ChangeBreakpoints clearall_breakpoint(this,VM_ChangeBreakpoints::CLEAR_ALL_BREAKPOINT);
501 VMThread::execute(&clearall_breakpoint);
502 }
503
504 //
505 // class JvmtiCurrentBreakpoints
506 //
507
508 JvmtiBreakpoints *JvmtiCurrentBreakpoints::_jvmti_breakpoints = NULL;
509 address * JvmtiCurrentBreakpoints::_breakpoint_list = NULL;
510
511
512 JvmtiBreakpoints& JvmtiCurrentBreakpoints::get_jvmti_breakpoints() {
513 if (_jvmti_breakpoints != NULL) return (*_jvmti_breakpoints);
514 _jvmti_breakpoints = new JvmtiBreakpoints(listener_fun);
515 assert(_jvmti_breakpoints != NULL, "_jvmti_breakpoints != NULL");
516 return (*_jvmti_breakpoints);
517 }
518
519 void JvmtiCurrentBreakpoints::listener_fun(void *this_obj, address *cache) {
520 JvmtiBreakpoints *this_jvmti = (JvmtiBreakpoints *) this_obj;
521 assert(this_jvmti != NULL, "this_jvmti != NULL");
522
523 debug_only(int n = this_jvmti->length(););
524 assert(cache[n] == NULL, "cache must be NULL terminated");
525
526 set_breakpoint_list(cache);
527 }
528
529
530 void JvmtiCurrentBreakpoints::oops_do(OopClosure* f) {
531 if (_jvmti_breakpoints != NULL) {
532 _jvmti_breakpoints->oops_do(f);
533 }
534 }
535
536 void JvmtiCurrentBreakpoints::gc_epilogue() {
537 if (_jvmti_breakpoints != NULL) {
538 _jvmti_breakpoints->gc_epilogue();
539 }
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
589 vframe *VM_GetOrSetLocal::get_vframe() {
590 if (!_thread->has_last_Java_frame()) {
591 return NULL;
592 }
593 RegisterMap reg_map(_thread);
594 vframe *vf = _thread->last_java_vframe(®_map);
595 int d = 0;
596 while ((vf != NULL) && (d < _depth)) {
597 vf = vf->java_sender();
598 d++;
599 }
600 return vf;
601 }
602
603 javaVFrame *VM_GetOrSetLocal::get_java_vframe() {
604 vframe* vf = get_vframe();
605 if (vf == NULL) {
606 _result = JVMTI_ERROR_NO_MORE_FRAMES;
607 return NULL;
608 }
609 javaVFrame *jvf = (javaVFrame*)vf;
610
611 if (!vf->is_java_frame() || jvf->method()->is_native()) {
612 _result = JVMTI_ERROR_OPAQUE_FRAME;
613 return NULL;
614 }
615 return jvf;
616 }
617
618 // Check that the klass is assignable to a type with the given signature.
619 // Another solution could be to use the function Klass::is_subtype_of(type).
620 // But the type class can be forced to load/initialize eagerly in such a case.
621 // This may cause unexpected consequences like CFLH or class-init JVMTI events.
622 // It is better to avoid such a behavior.
623 bool VM_GetOrSetLocal::is_assignable(const char* ty_sign, Klass* klass, Thread* thread) {
624 assert(ty_sign != NULL, "type signature must not be NULL");
625 assert(thread != NULL, "thread must not be NULL");
626 assert(klass != NULL, "klass must not be NULL");
627
628 int len = (int) strlen(ty_sign);
629 if (ty_sign[0] == 'L' && ty_sign[len-1] == ';') { // Need pure class/interface name
630 ty_sign++;
631 len -= 2;
632 }
633 symbolHandle ty_sym = oopFactory::new_symbol_handle(ty_sign, len, thread);
634 if (klass->name() == ty_sym()) {
635 return true;
636 }
637 // Compare primary supers
638 int super_depth = klass->super_depth();
639 int idx;
640 for (idx = 0; idx < super_depth; idx++) {
641 if (Klass::cast(klass->primary_super_of_depth(idx))->name() == ty_sym()) {
642 return true;
643 }
644 }
645 // Compare secondary supers
646 objArrayOop sec_supers = klass->secondary_supers();
647 for (idx = 0; idx < sec_supers->length(); idx++) {
648 if (Klass::cast((klassOop) sec_supers->obj_at(idx))->name() == ty_sym()) {
649 return true;
650 }
651 }
652 return false;
653 }
654
655 // Checks error conditions:
656 // JVMTI_ERROR_INVALID_SLOT
657 // JVMTI_ERROR_TYPE_MISMATCH
658 // Returns: 'true' - everything is Ok, 'false' - error code
659
660 bool VM_GetOrSetLocal::check_slot_type(javaVFrame* jvf) {
661 methodOop method_oop = jvf->method();
662 if (!method_oop->has_localvariable_table()) {
663 // Just to check index boundaries
664 jint extra_slot = (_type == T_LONG || _type == T_DOUBLE) ? 1 : 0;
665 if (_index < 0 || _index + extra_slot >= method_oop->max_locals()) {
666 _result = JVMTI_ERROR_INVALID_SLOT;
667 return false;
668 }
669 return true;
670 }
671
672 jint num_entries = method_oop->localvariable_table_length();
673 if (num_entries == 0) {
674 _result = JVMTI_ERROR_INVALID_SLOT;
675 return false; // There are no slots
676 }
677 int signature_idx = -1;
678 int vf_bci = jvf->bci();
679 LocalVariableTableElement* table = method_oop->localvariable_table_start();
680 for (int i = 0; i < num_entries; i++) {
681 int start_bci = table[i].start_bci;
682 int end_bci = start_bci + table[i].length;
683
684 // Here we assume that locations of LVT entries
685 // with the same slot number cannot be overlapped
686 if (_index == (jint) table[i].slot && start_bci <= vf_bci && vf_bci <= end_bci) {
687 signature_idx = (int) table[i].descriptor_cp_index;
688 break;
689 }
690 }
691 if (signature_idx == -1) {
692 _result = JVMTI_ERROR_INVALID_SLOT;
693 return false; // Incorrect slot index
694 }
695 symbolOop sign_sym = method_oop->constants()->symbol_at(signature_idx);
696 const char* signature = (const char *) sign_sym->as_utf8();
697 BasicType slot_type = char2type(signature[0]);
698
699 switch (slot_type) {
700 case T_BYTE:
701 case T_SHORT:
702 case T_CHAR:
703 case T_BOOLEAN:
704 slot_type = T_INT;
705 break;
706 case T_ARRAY:
707 slot_type = T_OBJECT;
708 break;
709 };
710 if (_type != slot_type) {
711 _result = JVMTI_ERROR_TYPE_MISMATCH;
712 return false;
713 }
714
715 jobject jobj = _value.l;
716 if (_set && slot_type == T_OBJECT && jobj != NULL) { // NULL reference is allowed
717 // Check that the jobject class matches the return type signature.
718 JavaThread* cur_thread = JavaThread::current();
719 HandleMark hm(cur_thread);
720
721 Handle obj = Handle(cur_thread, JNIHandles::resolve_external_guard(jobj));
722 NULL_CHECK(obj, (_result = JVMTI_ERROR_INVALID_OBJECT, false));
723 KlassHandle ob_kh = KlassHandle(cur_thread, obj->klass());
724 NULL_CHECK(ob_kh, (_result = JVMTI_ERROR_INVALID_OBJECT, false));
725
726 if (!is_assignable(signature, Klass::cast(ob_kh()), cur_thread)) {
727 _result = JVMTI_ERROR_TYPE_MISMATCH;
728 return false;
729 }
730 }
731 return true;
732 }
733
734 static bool can_be_deoptimized(vframe* vf) {
735 return (vf->is_compiled_frame() && vf->fr().can_be_deoptimized());
736 }
737
738 bool VM_GetOrSetLocal::doit_prologue() {
739 _jvf = get_java_vframe();
740 NULL_CHECK(_jvf, false);
741
742 if (!check_slot_type(_jvf)) {
743 return false;
744 }
745 return true;
746 }
747
748 void VM_GetOrSetLocal::doit() {
749 if (_set) {
750 // Force deoptimization of frame if compiled because it's
751 // possible the compiler emitted some locals as constant values,
752 // meaning they are not mutable.
753 if (can_be_deoptimized(_jvf)) {
754
755 // Schedule deoptimization so that eventually the local
756 // update will be written to an interpreter frame.
757 VM_DeoptimizeFrame deopt(_jvf->thread(), _jvf->fr().id());
758 VMThread::execute(&deopt);
759
760 // Now store a new value for the local which will be applied
761 // once deoptimization occurs. Note however that while this
762 // write is deferred until deoptimization actually happens
763 // can vframe created after this point will have its locals
764 // reflecting this update so as far as anyone can see the
765 // write has already taken place.
766
767 // If we are updating an oop then get the oop from the handle
768 // since the handle will be long gone by the time the deopt
769 // happens. The oop stored in the deferred local will be
770 // gc'd on its own.
771 if (_type == T_OBJECT) {
772 _value.l = (jobject) (JNIHandles::resolve_external_guard(_value.l));
773 }
774 // Re-read the vframe so we can see that it is deoptimized
775 // [ Only need because of assert in update_local() ]
776 _jvf = get_java_vframe();
777 ((compiledVFrame*)_jvf)->update_local(_type, _index, _value);
778 return;
779 }
780 StackValueCollection *locals = _jvf->locals();
781 HandleMark hm;
782
783 switch (_type) {
784 case T_INT: locals->set_int_at (_index, _value.i); break;
785 case T_LONG: locals->set_long_at (_index, _value.j); break;
786 case T_FLOAT: locals->set_float_at (_index, _value.f); break;
787 case T_DOUBLE: locals->set_double_at(_index, _value.d); break;
788 case T_OBJECT: {
789 Handle ob_h(JNIHandles::resolve_external_guard(_value.l));
790 locals->set_obj_at (_index, ob_h);
791 break;
792 }
793 default: ShouldNotReachHere();
794 }
795 _jvf->set_locals(locals);
796 } else {
797 StackValueCollection *locals = _jvf->locals();
798
799 if (locals->at(_index)->type() == T_CONFLICT) {
800 memset(&_value, 0, sizeof(_value));
801 _value.l = NULL;
802 return;
803 }
804
805 switch (_type) {
806 case T_INT: _value.i = locals->int_at (_index); break;
807 case T_LONG: _value.j = locals->long_at (_index); break;
808 case T_FLOAT: _value.f = locals->float_at (_index); break;
809 case T_DOUBLE: _value.d = locals->double_at(_index); break;
810 case T_OBJECT: {
811 // Wrap the oop to be returned in a local JNI handle since
812 // oops_do() no longer applies after doit() is finished.
813 oop obj = locals->obj_at(_index)();
814 _value.l = JNIHandles::make_local(_calling_thread, obj);
815 break;
816 }
817 default: ShouldNotReachHere();
818 }
819 }
820 }
821
822
823 bool VM_GetOrSetLocal::allow_nested_vm_operations() const {
824 return true; // May need to deoptimize
825 }
826
827
828 /////////////////////////////////////////////////////////////////////////////////////////
829
830 //
831 // class JvmtiSuspendControl - see comments in jvmtiImpl.hpp
832 //
833
834 bool JvmtiSuspendControl::suspend(JavaThread *java_thread) {
835 // external suspend should have caught suspending a thread twice
836
837 // Immediate suspension required for JPDA back-end so JVMTI agent threads do
838 // not deadlock due to later suspension on transitions while holding
839 // raw monitors. Passing true causes the immediate suspension.
840 // java_suspend() will catch threads in the process of exiting
841 // and will ignore them.
842 java_thread->java_suspend();
843
844 // It would be nice to have the following assertion in all the time,
845 // but it is possible for a racing resume request to have resumed
846 // this thread right after we suspended it. Temporarily enable this
847 // assertion if you are chasing a different kind of bug.
848 //
849 // assert(java_lang_Thread::thread(java_thread->threadObj()) == NULL ||
850 // java_thread->is_being_ext_suspended(), "thread is not suspended");
851
852 if (java_lang_Thread::thread(java_thread->threadObj()) == NULL) {
853 // check again because we can get delayed in java_suspend():
854 // the thread is in process of exiting.
855 return false;
856 }
857
858 return true;
859 }
860
861 bool JvmtiSuspendControl::resume(JavaThread *java_thread) {
862 // external suspend should have caught resuming a thread twice
863 assert(java_thread->is_being_ext_suspended(), "thread should be suspended");
864
865 // resume thread
866 {
867 // must always grab Threads_lock, see JVM_SuspendThread
868 MutexLocker ml(Threads_lock);
869 java_thread->java_resume();
870 }
871
872 return true;
873 }
874
875
876 void JvmtiSuspendControl::print() {
877 #ifndef PRODUCT
878 MutexLocker mu(Threads_lock);
879 ResourceMark rm;
880
881 tty->print("Suspended Threads: [");
882 for (JavaThread *thread = Threads::first(); thread != NULL; thread = thread->next()) {
883 #if JVMTI_TRACE
884 const char *name = JvmtiTrace::safe_get_thread_name(thread);
885 #else
886 const char *name = "";
887 #endif /*JVMTI_TRACE */
888 tty->print("%s(%c ", name, thread->is_being_ext_suspended() ? 'S' : '_');
889 if (!thread->has_last_Java_frame()) {
890 tty->print("no stack");
891 }
892 tty->print(") ");
893 }
894 tty->print_cr("]");
895 #endif
896 }