1 /*
2 * Copyright (c) 2003, 2013, 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/os.hpp"
42 #include "runtime/serviceThread.hpp"
43 #include "runtime/signature.hpp"
44 #include "runtime/vframe.hpp"
45 #include "runtime/vframe_hp.hpp"
46 #include "runtime/vm_operations.hpp"
47 #include "utilities/exceptions.hpp"
48 #ifdef TARGET_OS_FAMILY_linux
49 # include "thread_linux.inline.hpp"
50 #endif
51 #ifdef TARGET_OS_FAMILY_solaris
52 # include "thread_solaris.inline.hpp"
53 #endif
54 #ifdef TARGET_OS_FAMILY_windows
55 # include "thread_windows.inline.hpp"
56 #endif
57 #ifdef TARGET_OS_FAMILY_bsd
58 # include "thread_bsd.inline.hpp"
59 #endif
60
61 //
62 // class JvmtiAgentThread
63 //
64 // JavaThread used to wrap a thread started by an agent
65 // using the JVMTI method RunAgentThread.
66 //
67
68 JvmtiAgentThread::JvmtiAgentThread(JvmtiEnv* env, jvmtiStartFunction start_fn, const void *start_arg)
69 : JavaThread(start_function_wrapper) {
70 _env = env;
71 _start_fn = start_fn;
72 _start_arg = start_arg;
73 }
74
75 void
76 JvmtiAgentThread::start_function_wrapper(JavaThread *thread, TRAPS) {
77 // It is expected that any Agent threads will be created as
78 // Java Threads. If this is the case, notification of the creation
79 // of the thread is given in JavaThread::thread_main().
80 assert(thread->is_Java_thread(), "debugger thread should be a Java Thread");
81 assert(thread == JavaThread::current(), "sanity check");
82
83 JvmtiAgentThread *dthread = (JvmtiAgentThread *)thread;
84 dthread->call_start_function();
85 }
86
87 void
88 JvmtiAgentThread::call_start_function() {
89 ThreadToNativeFromVM transition(this);
90 _start_fn(_env->jvmti_external(), jni_environment(), (void*)_start_arg);
91 }
92
93
94 //
95 // class GrowableCache - private methods
96 //
97
98 void GrowableCache::recache() {
99 int len = _elements->length();
100
101 FREE_C_HEAP_ARRAY(address, _cache, mtInternal);
102 _cache = NEW_C_HEAP_ARRAY(address,len+1, mtInternal);
103
104 for (int i=0; i<len; i++) {
105 _cache[i] = _elements->at(i)->getCacheValue();
106 //
107 // The cache entry has gone bad. Without a valid frame pointer
108 // value, the entry is useless so we simply delete it in product
109 // mode. The call to remove() will rebuild the cache again
110 // without the bad entry.
111 //
112 if (_cache[i] == NULL) {
113 assert(false, "cannot recache NULL elements");
114 remove(i);
115 return;
116 }
117 }
118 _cache[len] = NULL;
119
120 _listener_fun(_this_obj,_cache);
121 }
122
123 bool GrowableCache::equals(void* v, GrowableElement *e2) {
124 GrowableElement *e1 = (GrowableElement *) v;
125 assert(e1 != NULL, "e1 != NULL");
126 assert(e2 != NULL, "e2 != NULL");
127
128 return e1->equals(e2);
129 }
130
131 //
132 // class GrowableCache - public methods
133 //
134
135 GrowableCache::GrowableCache() {
136 _this_obj = NULL;
137 _listener_fun = NULL;
138 _elements = NULL;
139 _cache = NULL;
140 }
141
142 GrowableCache::~GrowableCache() {
143 clear();
144 delete _elements;
145 FREE_C_HEAP_ARRAY(address, _cache, mtInternal);
146 }
147
148 void GrowableCache::initialize(void *this_obj, void listener_fun(void *, address*) ) {
149 _this_obj = this_obj;
150 _listener_fun = listener_fun;
151 _elements = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<GrowableElement*>(5,true);
152 recache();
153 }
154
155 // number of elements in the collection
156 int GrowableCache::length() {
157 return _elements->length();
158 }
159
160 // get the value of the index element in the collection
161 GrowableElement* GrowableCache::at(int index) {
162 GrowableElement *e = (GrowableElement *) _elements->at(index);
163 assert(e != NULL, "e != NULL");
164 return e;
165 }
166
167 int GrowableCache::find(GrowableElement* e) {
168 return _elements->find(e, GrowableCache::equals);
169 }
170
171 // append a copy of the element to the end of the collection
172 void GrowableCache::append(GrowableElement* e) {
173 GrowableElement *new_e = e->clone();
174 _elements->append(new_e);
175 recache();
176 }
177
178 // insert a copy of the element using lessthan()
179 void GrowableCache::insert(GrowableElement* e) {
180 GrowableElement *new_e = e->clone();
181 _elements->append(new_e);
182
183 int n = length()-2;
184 for (int i=n; i>=0; i--) {
185 GrowableElement *e1 = _elements->at(i);
186 GrowableElement *e2 = _elements->at(i+1);
187 if (e2->lessThan(e1)) {
188 _elements->at_put(i+1, e1);
189 _elements->at_put(i, e2);
190 }
191 }
192
193 recache();
194 }
195
196 // remove the element at index
197 void GrowableCache::remove (int index) {
198 GrowableElement *e = _elements->at(index);
199 assert(e != NULL, "e != NULL");
200 _elements->remove(e);
201 delete e;
202 recache();
203 }
204
205 // clear out all elements, release all heap space and
206 // let our listener know that things have changed.
207 void GrowableCache::clear() {
208 int len = _elements->length();
209 for (int i=0; i<len; i++) {
210 delete _elements->at(i);
211 }
212 _elements->clear();
213 recache();
214 }
215
216 void GrowableCache::oops_do(OopClosure* f) {
217 int len = _elements->length();
218 for (int i=0; i<len; i++) {
219 GrowableElement *e = _elements->at(i);
220 e->oops_do(f);
221 }
222 }
223
224 void GrowableCache::gc_epilogue() {
225 int len = _elements->length();
226 for (int i=0; i<len; i++) {
227 _cache[i] = _elements->at(i)->getCacheValue();
228 }
229 }
230
231 //
232 // class JvmtiBreakpoint
233 //
234
235 JvmtiBreakpoint::JvmtiBreakpoint() {
236 _method = NULL;
237 _bci = 0;
238 #ifdef CHECK_UNHANDLED_OOPS
239 // This one is always allocated with new, but check it just in case.
240 Thread *thread = Thread::current();
241 if (thread->is_in_stack((address)&_method)) {
242 thread->allow_unhandled_oop((oop*)&_method);
243 }
244 #endif // CHECK_UNHANDLED_OOPS
245 }
246
247 JvmtiBreakpoint::JvmtiBreakpoint(methodOop m_method, jlocation location) {
248 _method = m_method;
249 assert(_method != NULL, "_method != NULL");
250 _bci = (int) location;
251 #ifdef CHECK_UNHANDLED_OOPS
252 // Could be allocated with new and wouldn't be on the unhandled oop list.
253 Thread *thread = Thread::current();
254 if (thread->is_in_stack((address)&_method)) {
255 thread->allow_unhandled_oop(&_method);
256 }
257 #endif // CHECK_UNHANDLED_OOPS
258
259 assert(_bci >= 0, "_bci >= 0");
260 }
261
262 void JvmtiBreakpoint::copy(JvmtiBreakpoint& bp) {
263 _method = bp._method;
264 _bci = bp._bci;
265 }
266
267 bool JvmtiBreakpoint::lessThan(JvmtiBreakpoint& bp) {
268 Unimplemented();
269 return false;
270 }
271
272 bool JvmtiBreakpoint::equals(JvmtiBreakpoint& bp) {
273 return _method == bp._method
274 && _bci == bp._bci;
275 }
276
277 bool JvmtiBreakpoint::is_valid() {
278 return _method != NULL &&
279 _bci >= 0;
280 }
281
282 address JvmtiBreakpoint::getBcp() {
283 return _method->bcp_from(_bci);
284 }
285
286 void JvmtiBreakpoint::each_method_version_do(method_action meth_act) {
287 ((methodOopDesc*)_method->*meth_act)(_bci);
288
289 // add/remove breakpoint to/from versions of the method that
290 // are EMCP. Directly or transitively obsolete methods are
291 // not saved in the PreviousVersionInfo.
292 Thread *thread = Thread::current();
293 instanceKlassHandle ikh = instanceKlassHandle(thread, _method->method_holder());
294 Symbol* m_name = _method->name();
295 Symbol* m_signature = _method->signature();
296
297 {
298 ResourceMark rm(thread);
299 // PreviousVersionInfo objects returned via PreviousVersionWalker
300 // contain a GrowableArray of handles. We have to clean up the
301 // GrowableArray _after_ the PreviousVersionWalker destructor
302 // has destroyed the handles.
303 {
304 // search previous versions if they exist
305 PreviousVersionWalker pvw((instanceKlass *)ikh()->klass_part());
306 for (PreviousVersionInfo * pv_info = pvw.next_previous_version();
307 pv_info != NULL; pv_info = pvw.next_previous_version()) {
308 GrowableArray<methodHandle>* methods =
309 pv_info->prev_EMCP_method_handles();
310
311 if (methods == NULL) {
312 // We have run into a PreviousVersion generation where
313 // all methods were made obsolete during that generation's
314 // RedefineClasses() operation. At the time of that
315 // operation, all EMCP methods were flushed so we don't
316 // have to go back any further.
317 //
318 // A NULL methods array is different than an empty methods
319 // array. We cannot infer any optimizations about older
320 // generations from an empty methods array for the current
321 // generation.
322 break;
323 }
324
325 for (int i = methods->length() - 1; i >= 0; i--) {
326 methodHandle method = methods->at(i);
327 if (method->name() == m_name && method->signature() == m_signature) {
328 RC_TRACE(0x00000800, ("%sing breakpoint in %s(%s)",
329 meth_act == &methodOopDesc::set_breakpoint ? "sett" : "clear",
330 method->name()->as_C_string(),
331 method->signature()->as_C_string()));
332 assert(!method->is_obsolete(), "only EMCP methods here");
333
334 ((methodOopDesc*)method()->*meth_act)(_bci);
335 break;
336 }
337 }
338 }
339 } // pvw is cleaned up
340 } // rm is cleaned up
341 }
342
343 void JvmtiBreakpoint::set() {
344 each_method_version_do(&methodOopDesc::set_breakpoint);
345 }
346
347 void JvmtiBreakpoint::clear() {
348 each_method_version_do(&methodOopDesc::clear_breakpoint);
349 }
350
351 void JvmtiBreakpoint::print() {
352 #ifndef PRODUCT
353 const char *class_name = (_method == NULL) ? "NULL" : _method->klass_name()->as_C_string();
354 const char *method_name = (_method == NULL) ? "NULL" : _method->name()->as_C_string();
355
356 tty->print("Breakpoint(%s,%s,%d,%p)",class_name, method_name, _bci, getBcp());
357 #endif
358 }
359
360
361 //
362 // class VM_ChangeBreakpoints
363 //
364 // Modify the Breakpoints data structure at a safepoint
365 //
366
367 void VM_ChangeBreakpoints::doit() {
368 switch (_operation) {
369 case SET_BREAKPOINT:
370 _breakpoints->set_at_safepoint(*_bp);
371 break;
372 case CLEAR_BREAKPOINT:
373 _breakpoints->clear_at_safepoint(*_bp);
374 break;
375 default:
376 assert(false, "Unknown operation");
377 }
378 }
379
380 void VM_ChangeBreakpoints::oops_do(OopClosure* f) {
381 // The JvmtiBreakpoints in _breakpoints will be visited via
382 // JvmtiExport::oops_do.
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 int JvmtiBreakpoints::length() { return _bps.length(); }
444
445 int JvmtiBreakpoints::set(JvmtiBreakpoint& bp) {
446 if ( _bps.find(bp) != -1) {
447 return JVMTI_ERROR_DUPLICATE;
448 }
449 VM_ChangeBreakpoints set_breakpoint(VM_ChangeBreakpoints::SET_BREAKPOINT, &bp);
450 VMThread::execute(&set_breakpoint);
451 return JVMTI_ERROR_NONE;
452 }
453
454 int JvmtiBreakpoints::clear(JvmtiBreakpoint& bp) {
455 if ( _bps.find(bp) == -1) {
456 return JVMTI_ERROR_NOT_FOUND;
457 }
458
459 VM_ChangeBreakpoints clear_breakpoint(VM_ChangeBreakpoints::CLEAR_BREAKPOINT, &bp);
460 VMThread::execute(&clear_breakpoint);
461 return JVMTI_ERROR_NONE;
462 }
463
464 void JvmtiBreakpoints::clearall_in_class_at_safepoint(klassOop klass) {
465 bool changed = true;
466 // We are going to run thru the list of bkpts
467 // and delete some. This deletion probably alters
468 // the list in some implementation defined way such
469 // that when we delete entry i, the next entry might
470 // no longer be at i+1. To be safe, each time we delete
471 // an entry, we'll just start again from the beginning.
472 // We'll stop when we make a pass thru the whole list without
473 // deleting anything.
474 while (changed) {
475 int len = _bps.length();
476 changed = false;
477 for (int i = 0; i < len; i++) {
478 JvmtiBreakpoint& bp = _bps.at(i);
479 if (bp.method()->method_holder() == klass) {
480 bp.clear();
481 _bps.remove(i);
482 // This changed 'i' so we have to start over.
483 changed = true;
484 break;
485 }
486 }
487 }
488 }
489
490 //
491 // class JvmtiCurrentBreakpoints
492 //
493
494 JvmtiBreakpoints *JvmtiCurrentBreakpoints::_jvmti_breakpoints = NULL;
495 address * JvmtiCurrentBreakpoints::_breakpoint_list = NULL;
496
497
498 JvmtiBreakpoints& JvmtiCurrentBreakpoints::get_jvmti_breakpoints() {
499 if (_jvmti_breakpoints != NULL) return (*_jvmti_breakpoints);
500 _jvmti_breakpoints = new JvmtiBreakpoints(listener_fun);
501 assert(_jvmti_breakpoints != NULL, "_jvmti_breakpoints != NULL");
502 return (*_jvmti_breakpoints);
503 }
504
505 void JvmtiCurrentBreakpoints::listener_fun(void *this_obj, address *cache) {
506 JvmtiBreakpoints *this_jvmti = (JvmtiBreakpoints *) this_obj;
507 assert(this_jvmti != NULL, "this_jvmti != NULL");
508
509 debug_only(int n = this_jvmti->length(););
510 assert(cache[n] == NULL, "cache must be NULL terminated");
511
512 set_breakpoint_list(cache);
513 }
514
515
516 void JvmtiCurrentBreakpoints::oops_do(OopClosure* f) {
517 if (_jvmti_breakpoints != NULL) {
518 _jvmti_breakpoints->oops_do(f);
519 }
520 }
521
522 void JvmtiCurrentBreakpoints::gc_epilogue() {
523 if (_jvmti_breakpoints != NULL) {
524 _jvmti_breakpoints->gc_epilogue();
525 }
526 }
527
528 ///////////////////////////////////////////////////////////////
529 //
530 // class VM_GetOrSetLocal
531 //
532
533 // Constructor for non-object getter
534 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, jint depth, int index, BasicType type)
535 : _thread(thread)
536 , _calling_thread(NULL)
537 , _depth(depth)
538 , _index(index)
539 , _type(type)
540 , _set(false)
541 , _jvf(NULL)
542 , _result(JVMTI_ERROR_NONE)
543 {
544 }
545
546 // Constructor for object or non-object setter
547 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, jint depth, int index, BasicType type, jvalue value)
548 : _thread(thread)
549 , _calling_thread(NULL)
550 , _depth(depth)
551 , _index(index)
552 , _type(type)
553 , _value(value)
554 , _set(true)
555 , _jvf(NULL)
556 , _result(JVMTI_ERROR_NONE)
557 {
558 }
559
560 // Constructor for object getter
561 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, JavaThread* calling_thread, jint depth, int index)
562 : _thread(thread)
563 , _calling_thread(calling_thread)
564 , _depth(depth)
565 , _index(index)
566 , _type(T_OBJECT)
567 , _set(false)
568 , _jvf(NULL)
569 , _result(JVMTI_ERROR_NONE)
570 {
571 }
572
573 vframe *VM_GetOrSetLocal::get_vframe() {
574 if (!_thread->has_last_Java_frame()) {
575 return NULL;
576 }
577 RegisterMap reg_map(_thread);
578 vframe *vf = _thread->last_java_vframe(®_map);
579 int d = 0;
580 while ((vf != NULL) && (d < _depth)) {
581 vf = vf->java_sender();
582 d++;
583 }
584 return vf;
585 }
586
587 javaVFrame *VM_GetOrSetLocal::get_java_vframe() {
588 vframe* vf = get_vframe();
589 if (vf == NULL) {
590 _result = JVMTI_ERROR_NO_MORE_FRAMES;
591 return NULL;
592 }
593 javaVFrame *jvf = (javaVFrame*)vf;
594
595 if (!vf->is_java_frame()) {
596 _result = JVMTI_ERROR_OPAQUE_FRAME;
597 return NULL;
598 }
599 return jvf;
600 }
601
602 // Check that the klass is assignable to a type with the given signature.
603 // Another solution could be to use the function Klass::is_subtype_of(type).
604 // But the type class can be forced to load/initialize eagerly in such a case.
605 // This may cause unexpected consequences like CFLH or class-init JVMTI events.
606 // It is better to avoid such a behavior.
607 bool VM_GetOrSetLocal::is_assignable(const char* ty_sign, Klass* klass, Thread* thread) {
608 assert(ty_sign != NULL, "type signature must not be NULL");
609 assert(thread != NULL, "thread must not be NULL");
610 assert(klass != NULL, "klass must not be NULL");
611
612 int len = (int) strlen(ty_sign);
613 if (ty_sign[0] == 'L' && ty_sign[len-1] == ';') { // Need pure class/interface name
614 ty_sign++;
615 len -= 2;
616 }
617 TempNewSymbol ty_sym = SymbolTable::new_symbol(ty_sign, len, thread);
618 if (klass->name() == ty_sym) {
619 return true;
620 }
621 // Compare primary supers
622 int super_depth = klass->super_depth();
623 int idx;
624 for (idx = 0; idx < super_depth; idx++) {
625 if (Klass::cast(klass->primary_super_of_depth(idx))->name() == ty_sym) {
626 return true;
627 }
628 }
629 // Compare secondary supers
630 objArrayOop sec_supers = klass->secondary_supers();
631 for (idx = 0; idx < sec_supers->length(); idx++) {
632 if (Klass::cast((klassOop) sec_supers->obj_at(idx))->name() == ty_sym) {
633 return true;
634 }
635 }
636 return false;
637 }
638
639 // Checks error conditions:
640 // JVMTI_ERROR_INVALID_SLOT
641 // JVMTI_ERROR_TYPE_MISMATCH
642 // Returns: 'true' - everything is Ok, 'false' - error code
643
644 bool VM_GetOrSetLocal::check_slot_type(javaVFrame* jvf) {
645 methodOop method_oop = jvf->method();
646 if (!method_oop->has_localvariable_table()) {
647 // Just to check index boundaries
648 jint extra_slot = (_type == T_LONG || _type == T_DOUBLE) ? 1 : 0;
649 if (_index < 0 || _index + extra_slot >= method_oop->max_locals()) {
650 _result = JVMTI_ERROR_INVALID_SLOT;
651 return false;
652 }
653 return true;
654 }
655
656 jint num_entries = method_oop->localvariable_table_length();
657 if (num_entries == 0) {
658 _result = JVMTI_ERROR_INVALID_SLOT;
659 return false; // There are no slots
660 }
661 int signature_idx = -1;
662 int vf_bci = jvf->bci();
663 LocalVariableTableElement* table = method_oop->localvariable_table_start();
664 for (int i = 0; i < num_entries; i++) {
665 int start_bci = table[i].start_bci;
666 int end_bci = start_bci + table[i].length;
667
668 // Here we assume that locations of LVT entries
669 // with the same slot number cannot be overlapped
670 if (_index == (jint) table[i].slot && start_bci <= vf_bci && vf_bci <= end_bci) {
671 signature_idx = (int) table[i].descriptor_cp_index;
672 break;
673 }
674 }
675 if (signature_idx == -1) {
676 _result = JVMTI_ERROR_INVALID_SLOT;
677 return false; // Incorrect slot index
678 }
679 Symbol* sign_sym = method_oop->constants()->symbol_at(signature_idx);
680 const char* signature = (const char *) sign_sym->as_utf8();
681 BasicType slot_type = char2type(signature[0]);
682
683 switch (slot_type) {
684 case T_BYTE:
685 case T_SHORT:
686 case T_CHAR:
687 case T_BOOLEAN:
688 slot_type = T_INT;
689 break;
690 case T_ARRAY:
691 slot_type = T_OBJECT;
692 break;
693 };
694 if (_type != slot_type) {
695 _result = JVMTI_ERROR_TYPE_MISMATCH;
696 return false;
697 }
698
699 jobject jobj = _value.l;
700 if (_set && slot_type == T_OBJECT && jobj != NULL) { // NULL reference is allowed
701 // Check that the jobject class matches the return type signature.
702 JavaThread* cur_thread = JavaThread::current();
703 HandleMark hm(cur_thread);
704
705 Handle obj = Handle(cur_thread, JNIHandles::resolve_external_guard(jobj));
706 NULL_CHECK(obj, (_result = JVMTI_ERROR_INVALID_OBJECT, false));
707 KlassHandle ob_kh = KlassHandle(cur_thread, obj->klass());
708 NULL_CHECK(ob_kh, (_result = JVMTI_ERROR_INVALID_OBJECT, false));
709
710 if (!is_assignable(signature, Klass::cast(ob_kh()), cur_thread)) {
711 _result = JVMTI_ERROR_TYPE_MISMATCH;
712 return false;
713 }
714 }
715 return true;
716 }
717
718 static bool can_be_deoptimized(vframe* vf) {
719 return (vf->is_compiled_frame() && vf->fr().can_be_deoptimized());
720 }
721
722 bool VM_GetOrSetLocal::doit_prologue() {
723 _jvf = get_java_vframe();
724 NULL_CHECK(_jvf, false);
725
726 if (_jvf->method()->is_native()) {
727 if (getting_receiver() && !_jvf->method()->is_static()) {
728 return true;
729 } else {
730 _result = JVMTI_ERROR_OPAQUE_FRAME;
731 return false;
732 }
733 }
734
735 if (!check_slot_type(_jvf)) {
736 return false;
737 }
738 return true;
739 }
740
741 void VM_GetOrSetLocal::doit() {
742 if (_set) {
743 // Force deoptimization of frame if compiled because it's
744 // possible the compiler emitted some locals as constant values,
745 // meaning they are not mutable.
746 if (can_be_deoptimized(_jvf)) {
747
748 // Schedule deoptimization so that eventually the local
749 // update will be written to an interpreter frame.
750 Deoptimization::deoptimize_frame(_jvf->thread(), _jvf->fr().id());
751
752 // Now store a new value for the local which will be applied
753 // once deoptimization occurs. Note however that while this
754 // write is deferred until deoptimization actually happens
755 // can vframe created after this point will have its locals
756 // reflecting this update so as far as anyone can see the
757 // write has already taken place.
758
759 // If we are updating an oop then get the oop from the handle
760 // since the handle will be long gone by the time the deopt
761 // happens. The oop stored in the deferred local will be
762 // gc'd on its own.
763 if (_type == T_OBJECT) {
764 _value.l = (jobject) (JNIHandles::resolve_external_guard(_value.l));
765 }
766 // Re-read the vframe so we can see that it is deoptimized
767 // [ Only need because of assert in update_local() ]
768 _jvf = get_java_vframe();
769 ((compiledVFrame*)_jvf)->update_local(_type, _index, _value);
770 return;
771 }
772 StackValueCollection *locals = _jvf->locals();
773 HandleMark hm;
774
775 switch (_type) {
776 case T_INT: locals->set_int_at (_index, _value.i); break;
777 case T_LONG: locals->set_long_at (_index, _value.j); break;
778 case T_FLOAT: locals->set_float_at (_index, _value.f); break;
779 case T_DOUBLE: locals->set_double_at(_index, _value.d); break;
780 case T_OBJECT: {
781 Handle ob_h(JNIHandles::resolve_external_guard(_value.l));
782 locals->set_obj_at (_index, ob_h);
783 break;
784 }
785 default: ShouldNotReachHere();
786 }
787 _jvf->set_locals(locals);
788 } else {
789 if (_jvf->method()->is_native() && _jvf->is_compiled_frame()) {
790 assert(getting_receiver(), "Can only get here when getting receiver");
791 oop receiver = _jvf->fr().get_native_receiver();
792 _value.l = JNIHandles::make_local(_calling_thread, receiver);
793 } else {
794 StackValueCollection *locals = _jvf->locals();
795
796 if (locals->at(_index)->type() == T_CONFLICT) {
797 memset(&_value, 0, sizeof(_value));
798 _value.l = NULL;
799 return;
800 }
801
802 switch (_type) {
803 case T_INT: _value.i = locals->int_at (_index); break;
804 case T_LONG: _value.j = locals->long_at (_index); break;
805 case T_FLOAT: _value.f = locals->float_at (_index); break;
806 case T_DOUBLE: _value.d = locals->double_at(_index); break;
807 case T_OBJECT: {
808 // Wrap the oop to be returned in a local JNI handle since
809 // oops_do() no longer applies after doit() is finished.
810 oop obj = locals->obj_at(_index)();
811 _value.l = JNIHandles::make_local(_calling_thread, obj);
812 break;
813 }
814 default: ShouldNotReachHere();
815 }
816 }
817 }
818 }
819
820
821 bool VM_GetOrSetLocal::allow_nested_vm_operations() const {
822 return true; // May need to deoptimize
823 }
824
825
826 VM_GetReceiver::VM_GetReceiver(
827 JavaThread* thread, JavaThread* caller_thread, jint depth)
828 : VM_GetOrSetLocal(thread, caller_thread, depth, 0) {}
829
830 /////////////////////////////////////////////////////////////////////////////////////////
831
832 //
833 // class JvmtiSuspendControl - see comments in jvmtiImpl.hpp
834 //
835
836 bool JvmtiSuspendControl::suspend(JavaThread *java_thread) {
837 // external suspend should have caught suspending a thread twice
838
839 // Immediate suspension required for JPDA back-end so JVMTI agent threads do
840 // not deadlock due to later suspension on transitions while holding
841 // raw monitors. Passing true causes the immediate suspension.
842 // java_suspend() will catch threads in the process of exiting
843 // and will ignore them.
844 java_thread->java_suspend();
845
846 // It would be nice to have the following assertion in all the time,
847 // but it is possible for a racing resume request to have resumed
848 // this thread right after we suspended it. Temporarily enable this
849 // assertion if you are chasing a different kind of bug.
850 //
851 // assert(java_lang_Thread::thread(java_thread->threadObj()) == NULL ||
852 // java_thread->is_being_ext_suspended(), "thread is not suspended");
853
854 if (java_lang_Thread::thread(java_thread->threadObj()) == NULL) {
855 // check again because we can get delayed in java_suspend():
856 // the thread is in process of exiting.
857 return false;
858 }
859
860 return true;
861 }
862
863 bool JvmtiSuspendControl::resume(JavaThread *java_thread) {
864 // external suspend should have caught resuming a thread twice
865 assert(java_thread->is_being_ext_suspended(), "thread should be suspended");
866
867 // resume thread
868 {
869 // must always grab Threads_lock, see JVM_SuspendThread
870 MutexLocker ml(Threads_lock);
871 java_thread->java_resume();
872 }
873
874 return true;
875 }
876
877
878 void JvmtiSuspendControl::print() {
879 #ifndef PRODUCT
880 MutexLocker mu(Threads_lock);
881 ResourceMark rm;
882
883 tty->print("Suspended Threads: [");
884 for (JavaThread *thread = Threads::first(); thread != NULL; thread = thread->next()) {
885 #if JVMTI_TRACE
886 const char *name = JvmtiTrace::safe_get_thread_name(thread);
887 #else
888 const char *name = "";
889 #endif /*JVMTI_TRACE */
890 tty->print("%s(%c ", name, thread->is_being_ext_suspended() ? 'S' : '_');
891 if (!thread->has_last_Java_frame()) {
892 tty->print("no stack");
893 }
894 tty->print(") ");
895 }
896 tty->print_cr("]");
897 #endif
898 }
899
900 JvmtiDeferredEvent JvmtiDeferredEvent::compiled_method_load_event(
901 nmethod* nm) {
902 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_COMPILED_METHOD_LOAD);
903 event._event_data.compiled_method_load = nm;
904 // Keep the nmethod alive until the ServiceThread can process
905 // this deferred event.
906 nmethodLocker::lock_nmethod(nm);
907 return event;
908 }
909
910 JvmtiDeferredEvent JvmtiDeferredEvent::compiled_method_unload_event(
911 nmethod* nm, jmethodID id, const void* code) {
912 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_COMPILED_METHOD_UNLOAD);
913 event._event_data.compiled_method_unload.nm = nm;
914 event._event_data.compiled_method_unload.method_id = id;
915 event._event_data.compiled_method_unload.code_begin = code;
916 // Keep the nmethod alive until the ServiceThread can process
917 // this deferred event. This will keep the memory for the
918 // generated code from being reused too early. We pass
919 // zombie_ok == true here so that our nmethod that was just
920 // made into a zombie can be locked.
921 nmethodLocker::lock_nmethod(nm, true /* zombie_ok */);
922 return event;
923 }
924
925 JvmtiDeferredEvent JvmtiDeferredEvent::dynamic_code_generated_event(
926 const char* name, const void* code_begin, const void* code_end) {
927 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_DYNAMIC_CODE_GENERATED);
928 // Need to make a copy of the name since we don't know how long
929 // the event poster will keep it around after we enqueue the
930 // deferred event and return. strdup() failure is handled in
931 // the post() routine below.
932 event._event_data.dynamic_code_generated.name = os::strdup(name);
933 event._event_data.dynamic_code_generated.code_begin = code_begin;
934 event._event_data.dynamic_code_generated.code_end = code_end;
935 return event;
936 }
937
938 void JvmtiDeferredEvent::post() {
939 assert(ServiceThread::is_service_thread(Thread::current()),
940 "Service thread must post enqueued events");
941 switch(_type) {
942 case TYPE_COMPILED_METHOD_LOAD: {
943 nmethod* nm = _event_data.compiled_method_load;
944 JvmtiExport::post_compiled_method_load(nm);
945 // done with the deferred event so unlock the nmethod
946 nmethodLocker::unlock_nmethod(nm);
947 break;
948 }
949 case TYPE_COMPILED_METHOD_UNLOAD: {
950 nmethod* nm = _event_data.compiled_method_unload.nm;
951 JvmtiExport::post_compiled_method_unload(
952 _event_data.compiled_method_unload.method_id,
953 _event_data.compiled_method_unload.code_begin);
954 // done with the deferred event so unlock the nmethod
955 nmethodLocker::unlock_nmethod(nm);
956 break;
957 }
958 case TYPE_DYNAMIC_CODE_GENERATED: {
959 JvmtiExport::post_dynamic_code_generated_internal(
960 // if strdup failed give the event a default name
961 (_event_data.dynamic_code_generated.name == NULL)
962 ? "unknown_code" : _event_data.dynamic_code_generated.name,
963 _event_data.dynamic_code_generated.code_begin,
964 _event_data.dynamic_code_generated.code_end);
965 if (_event_data.dynamic_code_generated.name != NULL) {
966 // release our copy
967 os::free((void *)_event_data.dynamic_code_generated.name);
968 }
969 break;
970 }
971 default:
972 ShouldNotReachHere();
973 }
974 }
975
976 JvmtiDeferredEventQueue::QueueNode* JvmtiDeferredEventQueue::_queue_tail = NULL;
977 JvmtiDeferredEventQueue::QueueNode* JvmtiDeferredEventQueue::_queue_head = NULL;
978
979 volatile JvmtiDeferredEventQueue::QueueNode*
980 JvmtiDeferredEventQueue::_pending_list = NULL;
981
982 bool JvmtiDeferredEventQueue::has_events() {
983 assert(Service_lock->owned_by_self(), "Must own Service_lock");
984 return _queue_head != NULL || _pending_list != NULL;
985 }
986
987 void JvmtiDeferredEventQueue::enqueue(const JvmtiDeferredEvent& event) {
988 assert(Service_lock->owned_by_self(), "Must own Service_lock");
989
990 process_pending_events();
991
992 // Events get added to the end of the queue (and are pulled off the front).
993 QueueNode* node = new QueueNode(event);
994 if (_queue_tail == NULL) {
995 _queue_tail = _queue_head = node;
996 } else {
997 assert(_queue_tail->next() == NULL, "Must be the last element in the list");
998 _queue_tail->set_next(node);
999 _queue_tail = node;
1000 }
1001
1002 Service_lock->notify_all();
1003 assert((_queue_head == NULL) == (_queue_tail == NULL),
1004 "Inconsistent queue markers");
1005 }
1006
1007 JvmtiDeferredEvent JvmtiDeferredEventQueue::dequeue() {
1008 assert(Service_lock->owned_by_self(), "Must own Service_lock");
1009
1010 process_pending_events();
1011
1012 assert(_queue_head != NULL, "Nothing to dequeue");
1013
1014 if (_queue_head == NULL) {
1015 // Just in case this happens in product; it shouldn't but let's not crash
1016 return JvmtiDeferredEvent();
1017 }
1018
1019 QueueNode* node = _queue_head;
1020 _queue_head = _queue_head->next();
1021 if (_queue_head == NULL) {
1022 _queue_tail = NULL;
1023 }
1024
1025 assert((_queue_head == NULL) == (_queue_tail == NULL),
1026 "Inconsistent queue markers");
1027
1028 JvmtiDeferredEvent event = node->event();
1029 delete node;
1030 return event;
1031 }
1032
1033 void JvmtiDeferredEventQueue::add_pending_event(
1034 const JvmtiDeferredEvent& event) {
1035
1036 QueueNode* node = new QueueNode(event);
1037
1038 bool success = false;
1039 QueueNode* prev_value = (QueueNode*)_pending_list;
1040 do {
1041 node->set_next(prev_value);
1042 prev_value = (QueueNode*)Atomic::cmpxchg_ptr(
1043 (void*)node, (volatile void*)&_pending_list, (void*)node->next());
1044 } while (prev_value != node->next());
1045 }
1046
1047 // This method transfers any events that were added by someone NOT holding
1048 // the lock into the mainline queue.
1049 void JvmtiDeferredEventQueue::process_pending_events() {
1050 assert(Service_lock->owned_by_self(), "Must own Service_lock");
1051
1052 if (_pending_list != NULL) {
1053 QueueNode* head =
1054 (QueueNode*)Atomic::xchg_ptr(NULL, (volatile void*)&_pending_list);
1055
1056 assert((_queue_head == NULL) == (_queue_tail == NULL),
1057 "Inconsistent queue markers");
1058
1059 if (head != NULL) {
1060 // Since we've treated the pending list as a stack (with newer
1061 // events at the beginning), we need to join the bottom of the stack
1062 // with the 'tail' of the queue in order to get the events in the
1063 // right order. We do this by reversing the pending list and appending
1064 // it to the queue.
1065
1066 QueueNode* new_tail = head;
1067 QueueNode* new_head = NULL;
1068
1069 // This reverses the list
1070 QueueNode* prev = new_tail;
1071 QueueNode* node = new_tail->next();
1072 new_tail->set_next(NULL);
1073 while (node != NULL) {
1074 QueueNode* next = node->next();
1075 node->set_next(prev);
1076 prev = node;
1077 node = next;
1078 }
1079 new_head = prev;
1080
1081 // Now append the new list to the queue
1082 if (_queue_tail != NULL) {
1083 _queue_tail->set_next(new_head);
1084 } else { // _queue_head == NULL
1085 _queue_head = new_head;
1086 }
1087 _queue_tail = new_tail;
1088 }
1089 }
1090 }