1 /*
2 * Copyright (c) 2003, 2012, 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 _class_loader = NULL;
239 #ifdef CHECK_UNHANDLED_OOPS
240 // This one is always allocated with new, but check it just in case.
241 Thread *thread = Thread::current();
242 if (thread->is_in_stack((address)&_method)) {
243 thread->allow_unhandled_oop((oop*)&_method);
244 }
245 #endif // CHECK_UNHANDLED_OOPS
246 }
247
248 JvmtiBreakpoint::JvmtiBreakpoint(Method* m_method, jlocation location) {
249 _method = m_method;
250 _class_loader = _method->method_holder()->class_loader_data()->class_loader();
251 assert(_method != NULL, "_method != NULL");
252 _bci = (int) location;
253 assert(_bci >= 0, "_bci >= 0");
254 }
255
256 void JvmtiBreakpoint::copy(JvmtiBreakpoint& bp) {
257 _method = bp._method;
258 _bci = bp._bci;
259 _class_loader = bp._class_loader;
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 // class loader can be NULL
274 return _method != NULL &&
275 _bci >= 0;
276 }
277
278 address JvmtiBreakpoint::getBcp() {
279 return _method->bcp_from(_bci);
280 }
281
282 void JvmtiBreakpoint::each_method_version_do(method_action meth_act) {
283 ((Method*)_method->*meth_act)(_bci);
284
285 // add/remove breakpoint to/from versions of the method that
286 // are EMCP. Directly or transitively obsolete methods are
287 // not saved in the PreviousVersionInfo.
288 Thread *thread = Thread::current();
289 instanceKlassHandle ikh = instanceKlassHandle(thread, _method->method_holder());
290 Symbol* m_name = _method->name();
291 Symbol* m_signature = _method->signature();
292
293 {
294 ResourceMark rm(thread);
295 // PreviousVersionInfo objects returned via PreviousVersionWalker
296 // contain a GrowableArray of handles. We have to clean up the
297 // GrowableArray _after_ the PreviousVersionWalker destructor
298 // has destroyed the handles.
299 {
300 // search previous versions if they exist
301 PreviousVersionWalker pvw((InstanceKlass *)ikh());
302 for (PreviousVersionInfo * pv_info = pvw.next_previous_version();
303 pv_info != NULL; pv_info = pvw.next_previous_version()) {
304 GrowableArray<methodHandle>* methods =
305 pv_info->prev_EMCP_method_handles();
306
307 if (methods == NULL) {
308 // We have run into a PreviousVersion generation where
309 // all methods were made obsolete during that generation's
310 // RedefineClasses() operation. At the time of that
311 // operation, all EMCP methods were flushed so we don't
312 // have to go back any further.
313 //
314 // A NULL methods array is different than an empty methods
315 // array. We cannot infer any optimizations about older
316 // generations from an empty methods array for the current
317 // generation.
318 break;
319 }
320
321 for (int i = methods->length() - 1; i >= 0; i--) {
322 methodHandle method = methods->at(i);
323 // obsolete methods that are running are not deleted from
324 // previous version array, but they are skipped here.
325 if (!method->is_obsolete() &&
326 method->name() == m_name &&
327 method->signature() == m_signature) {
328 RC_TRACE(0x00000800, ("%sing breakpoint in %s(%s)",
329 meth_act == &Method::set_breakpoint ? "sett" : "clear",
330 method->name()->as_C_string(),
331 method->signature()->as_C_string()));
332
333 ((Method*)method()->*meth_act)(_bci);
334 break;
335 }
336 }
337 }
338 } // pvw is cleaned up
339 } // rm is cleaned up
340 }
341
342 void JvmtiBreakpoint::set() {
343 each_method_version_do(&Method::set_breakpoint);
344 }
345
346 void JvmtiBreakpoint::clear() {
347 each_method_version_do(&Method::clear_breakpoint);
348 }
349
350 void JvmtiBreakpoint::print() {
351 #ifndef PRODUCT
352 const char *class_name = (_method == NULL) ? "NULL" : _method->klass_name()->as_C_string();
353 const char *method_name = (_method == NULL) ? "NULL" : _method->name()->as_C_string();
354
355 tty->print("Breakpoint(%s,%s,%d,%p)",class_name, method_name, _bci, getBcp());
356 #endif
357 }
358
359
360 //
361 // class VM_ChangeBreakpoints
362 //
363 // Modify the Breakpoints data structure at a safepoint
364 //
365
366 void VM_ChangeBreakpoints::doit() {
367 switch (_operation) {
368 case SET_BREAKPOINT:
369 _breakpoints->set_at_safepoint(*_bp);
370 break;
371 case CLEAR_BREAKPOINT:
372 _breakpoints->clear_at_safepoint(*_bp);
373 break;
374 case CLEAR_ALL_BREAKPOINT:
375 _breakpoints->clearall_at_safepoint();
376 break;
377 default:
378 assert(false, "Unknown operation");
379 }
380 }
381
382 void VM_ChangeBreakpoints::oops_do(OopClosure* f) {
383 // This operation keeps breakpoints alive
384 if (_breakpoints != NULL) {
385 _breakpoints->oops_do(f);
386 }
387 if (_bp != NULL) {
388 _bp->oops_do(f);
389 }
390 }
391
392 //
393 // class JvmtiBreakpoints
394 //
395 // a JVMTI internal collection of JvmtiBreakpoint
396 //
397
398 JvmtiBreakpoints::JvmtiBreakpoints(void listener_fun(void *,address *)) {
399 _bps.initialize(this,listener_fun);
400 }
401
402 JvmtiBreakpoints:: ~JvmtiBreakpoints() {}
403
404 void JvmtiBreakpoints::oops_do(OopClosure* f) {
405 _bps.oops_do(f);
406 }
407
408 void JvmtiBreakpoints::gc_epilogue() {
409 _bps.gc_epilogue();
410 }
411
412 void JvmtiBreakpoints::print() {
413 #ifndef PRODUCT
414 ResourceMark rm;
415
416 int n = _bps.length();
417 for (int i=0; i<n; i++) {
418 JvmtiBreakpoint& bp = _bps.at(i);
419 tty->print("%d: ", i);
420 bp.print();
421 tty->print_cr("");
422 }
423 #endif
424 }
425
426
427 void JvmtiBreakpoints::set_at_safepoint(JvmtiBreakpoint& bp) {
428 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
429
430 int i = _bps.find(bp);
431 if (i == -1) {
432 _bps.append(bp);
433 bp.set();
434 }
435 }
436
437 void JvmtiBreakpoints::clear_at_safepoint(JvmtiBreakpoint& bp) {
438 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
439
440 int i = _bps.find(bp);
441 if (i != -1) {
442 _bps.remove(i);
443 bp.clear();
444 }
445 }
446
447 void JvmtiBreakpoints::clearall_at_safepoint() {
448 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
449
450 int len = _bps.length();
451 for (int i=0; i<len; i++) {
452 _bps.at(i).clear();
453 }
454 _bps.clear();
455 }
456
457 int JvmtiBreakpoints::length() { return _bps.length(); }
458
459 int JvmtiBreakpoints::set(JvmtiBreakpoint& bp) {
460 if ( _bps.find(bp) != -1) {
461 return JVMTI_ERROR_DUPLICATE;
462 }
463 VM_ChangeBreakpoints set_breakpoint(this,VM_ChangeBreakpoints::SET_BREAKPOINT, &bp);
464 VMThread::execute(&set_breakpoint);
465 return JVMTI_ERROR_NONE;
466 }
467
468 int JvmtiBreakpoints::clear(JvmtiBreakpoint& bp) {
469 if ( _bps.find(bp) == -1) {
470 return JVMTI_ERROR_NOT_FOUND;
471 }
472
473 VM_ChangeBreakpoints clear_breakpoint(this,VM_ChangeBreakpoints::CLEAR_BREAKPOINT, &bp);
474 VMThread::execute(&clear_breakpoint);
475 return JVMTI_ERROR_NONE;
476 }
477
478 void JvmtiBreakpoints::clearall_in_class_at_safepoint(Klass* klass) {
479 bool changed = true;
480 // We are going to run thru the list of bkpts
481 // and delete some. This deletion probably alters
482 // the list in some implementation defined way such
483 // that when we delete entry i, the next entry might
484 // no longer be at i+1. To be safe, each time we delete
485 // an entry, we'll just start again from the beginning.
486 // We'll stop when we make a pass thru the whole list without
487 // deleting anything.
488 while (changed) {
489 int len = _bps.length();
490 changed = false;
491 for (int i = 0; i < len; i++) {
492 JvmtiBreakpoint& bp = _bps.at(i);
493 if (bp.method()->method_holder() == klass) {
494 bp.clear();
495 _bps.remove(i);
496 // This changed 'i' so we have to start over.
497 changed = true;
498 break;
499 }
500 }
501 }
502 }
503
504 void JvmtiBreakpoints::clearall() {
505 VM_ChangeBreakpoints clearall_breakpoint(this,VM_ChangeBreakpoints::CLEAR_ALL_BREAKPOINT);
506 VMThread::execute(&clearall_breakpoint);
507 }
508
509 //
510 // class JvmtiCurrentBreakpoints
511 //
512
513 JvmtiBreakpoints *JvmtiCurrentBreakpoints::_jvmti_breakpoints = NULL;
514 address * JvmtiCurrentBreakpoints::_breakpoint_list = NULL;
515
516
517 JvmtiBreakpoints& JvmtiCurrentBreakpoints::get_jvmti_breakpoints() {
518 if (_jvmti_breakpoints != NULL) return (*_jvmti_breakpoints);
519 _jvmti_breakpoints = new JvmtiBreakpoints(listener_fun);
520 assert(_jvmti_breakpoints != NULL, "_jvmti_breakpoints != NULL");
521 return (*_jvmti_breakpoints);
522 }
523
524 void JvmtiCurrentBreakpoints::listener_fun(void *this_obj, address *cache) {
525 JvmtiBreakpoints *this_jvmti = (JvmtiBreakpoints *) this_obj;
526 assert(this_jvmti != NULL, "this_jvmti != NULL");
527
528 debug_only(int n = this_jvmti->length(););
529 assert(cache[n] == NULL, "cache must be NULL terminated");
530
531 set_breakpoint_list(cache);
532 }
533
534
535 void JvmtiCurrentBreakpoints::oops_do(OopClosure* f) {
536 if (_jvmti_breakpoints != NULL) {
537 _jvmti_breakpoints->oops_do(f);
538 }
539 }
540
541 void JvmtiCurrentBreakpoints::gc_epilogue() {
542 if (_jvmti_breakpoints != NULL) {
543 _jvmti_breakpoints->gc_epilogue();
544 }
545 }
546
547 ///////////////////////////////////////////////////////////////
548 //
549 // class VM_GetOrSetLocal
550 //
551
552 // Constructor for non-object getter
553 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, jint depth, int index, BasicType type)
554 : _thread(thread)
555 , _calling_thread(NULL)
556 , _depth(depth)
557 , _index(index)
558 , _type(type)
559 , _set(false)
560 , _jvf(NULL)
561 , _result(JVMTI_ERROR_NONE)
562 {
563 }
564
565 // Constructor for object or non-object setter
566 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, jint depth, int index, BasicType type, jvalue value)
567 : _thread(thread)
568 , _calling_thread(NULL)
569 , _depth(depth)
570 , _index(index)
571 , _type(type)
572 , _value(value)
573 , _set(true)
574 , _jvf(NULL)
575 , _result(JVMTI_ERROR_NONE)
576 {
577 }
578
579 // Constructor for object getter
580 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, JavaThread* calling_thread, jint depth, int index)
581 : _thread(thread)
582 , _calling_thread(calling_thread)
583 , _depth(depth)
584 , _index(index)
585 , _type(T_OBJECT)
586 , _set(false)
587 , _jvf(NULL)
588 , _result(JVMTI_ERROR_NONE)
589 {
590 }
591
592 vframe *VM_GetOrSetLocal::get_vframe() {
593 if (!_thread->has_last_Java_frame()) {
594 return NULL;
595 }
596 RegisterMap reg_map(_thread);
597 vframe *vf = _thread->last_java_vframe(®_map);
598 int d = 0;
599 while ((vf != NULL) && (d < _depth)) {
600 vf = vf->java_sender();
601 d++;
602 }
603 return vf;
604 }
605
606 javaVFrame *VM_GetOrSetLocal::get_java_vframe() {
607 vframe* vf = get_vframe();
608 if (vf == NULL) {
609 _result = JVMTI_ERROR_NO_MORE_FRAMES;
610 return NULL;
611 }
612 javaVFrame *jvf = (javaVFrame*)vf;
613
614 if (!vf->is_java_frame()) {
615 _result = JVMTI_ERROR_OPAQUE_FRAME;
616 return NULL;
617 }
618 return jvf;
619 }
620
621 // Check that the klass is assignable to a type with the given signature.
622 // Another solution could be to use the function Klass::is_subtype_of(type).
623 // But the type class can be forced to load/initialize eagerly in such a case.
624 // This may cause unexpected consequences like CFLH or class-init JVMTI events.
625 // It is better to avoid such a behavior.
626 bool VM_GetOrSetLocal::is_assignable(const char* ty_sign, Klass* klass, Thread* thread) {
627 assert(ty_sign != NULL, "type signature must not be NULL");
628 assert(thread != NULL, "thread must not be NULL");
629 assert(klass != NULL, "klass must not be NULL");
630
631 int len = (int) strlen(ty_sign);
632 if (ty_sign[0] == 'L' && ty_sign[len-1] == ';') { // Need pure class/interface name
633 ty_sign++;
634 len -= 2;
635 }
636 TempNewSymbol ty_sym = SymbolTable::new_symbol(ty_sign, len, thread);
637 if (klass->name() == ty_sym) {
638 return true;
639 }
640 // Compare primary supers
641 int super_depth = klass->super_depth();
642 int idx;
643 for (idx = 0; idx < super_depth; idx++) {
644 if (klass->primary_super_of_depth(idx)->name() == ty_sym) {
645 return true;
646 }
647 }
648 // Compare secondary supers
649 Array<Klass*>* sec_supers = klass->secondary_supers();
650 for (idx = 0; idx < sec_supers->length(); idx++) {
651 if (((Klass*) sec_supers->at(idx))->name() == ty_sym) {
652 return true;
653 }
654 }
655 return false;
656 }
657
658 // Checks error conditions:
659 // JVMTI_ERROR_INVALID_SLOT
660 // JVMTI_ERROR_TYPE_MISMATCH
661 // Returns: 'true' - everything is Ok, 'false' - error code
662
663 bool VM_GetOrSetLocal::check_slot_type(javaVFrame* jvf) {
664 Method* method_oop = jvf->method();
665 if (!method_oop->has_localvariable_table()) {
666 // Just to check index boundaries
667 jint extra_slot = (_type == T_LONG || _type == T_DOUBLE) ? 1 : 0;
668 if (_index < 0 || _index + extra_slot >= method_oop->max_locals()) {
669 _result = JVMTI_ERROR_INVALID_SLOT;
670 return false;
671 }
672 return true;
673 }
674
675 jint num_entries = method_oop->localvariable_table_length();
676 if (num_entries == 0) {
677 _result = JVMTI_ERROR_INVALID_SLOT;
678 return false; // There are no slots
679 }
680 int signature_idx = -1;
681 int vf_bci = jvf->bci();
682 LocalVariableTableElement* table = method_oop->localvariable_table_start();
683 for (int i = 0; i < num_entries; i++) {
684 int start_bci = table[i].start_bci;
685 int end_bci = start_bci + table[i].length;
686
687 // Here we assume that locations of LVT entries
688 // with the same slot number cannot be overlapped
689 if (_index == (jint) table[i].slot && start_bci <= vf_bci && vf_bci <= end_bci) {
690 signature_idx = (int) table[i].descriptor_cp_index;
691 break;
692 }
693 }
694 if (signature_idx == -1) {
695 _result = JVMTI_ERROR_INVALID_SLOT;
696 return false; // Incorrect slot index
697 }
698 Symbol* sign_sym = method_oop->constants()->symbol_at(signature_idx);
699 const char* signature = (const char *) sign_sym->as_utf8();
700 BasicType slot_type = char2type(signature[0]);
701
702 switch (slot_type) {
703 case T_BYTE:
704 case T_SHORT:
705 case T_CHAR:
706 case T_BOOLEAN:
707 slot_type = T_INT;
708 break;
709 case T_ARRAY:
710 slot_type = T_OBJECT;
711 break;
712 };
713 if (_type != slot_type) {
714 _result = JVMTI_ERROR_TYPE_MISMATCH;
715 return false;
716 }
717
718 jobject jobj = _value.l;
719 if (_set && slot_type == T_OBJECT && jobj != NULL) { // NULL reference is allowed
720 // Check that the jobject class matches the return type signature.
721 JavaThread* cur_thread = JavaThread::current();
722 HandleMark hm(cur_thread);
723
724 Handle obj = Handle(cur_thread, JNIHandles::resolve_external_guard(jobj));
725 NULL_CHECK(obj, (_result = JVMTI_ERROR_INVALID_OBJECT, false));
726 KlassHandle ob_kh = KlassHandle(cur_thread, obj->klass());
727 NULL_CHECK(ob_kh, (_result = JVMTI_ERROR_INVALID_OBJECT, false));
728
729 if (!is_assignable(signature, ob_kh(), cur_thread)) {
730 _result = JVMTI_ERROR_TYPE_MISMATCH;
731 return false;
732 }
733 }
734 return true;
735 }
736
737 static bool can_be_deoptimized(vframe* vf) {
738 return (vf->is_compiled_frame() && vf->fr().can_be_deoptimized());
739 }
740
741 bool VM_GetOrSetLocal::doit_prologue() {
742 _jvf = get_java_vframe();
743 NULL_CHECK(_jvf, false);
744
745 if (_jvf->method()->is_native()) {
746 if (getting_receiver() && !_jvf->method()->is_static()) {
747 return true;
748 } else {
749 _result = JVMTI_ERROR_OPAQUE_FRAME;
750 return false;
751 }
752 }
753
754 if (!check_slot_type(_jvf)) {
755 return false;
756 }
757 return true;
758 }
759
760 void VM_GetOrSetLocal::doit() {
761 if (_set) {
762 // Force deoptimization of frame if compiled because it's
763 // possible the compiler emitted some locals as constant values,
764 // meaning they are not mutable.
765 if (can_be_deoptimized(_jvf)) {
766
767 // Schedule deoptimization so that eventually the local
768 // update will be written to an interpreter frame.
769 Deoptimization::deoptimize_frame(_jvf->thread(), _jvf->fr().id());
770
771 // Now store a new value for the local which will be applied
772 // once deoptimization occurs. Note however that while this
773 // write is deferred until deoptimization actually happens
774 // can vframe created after this point will have its locals
775 // reflecting this update so as far as anyone can see the
776 // write has already taken place.
777
778 // If we are updating an oop then get the oop from the handle
779 // since the handle will be long gone by the time the deopt
780 // happens. The oop stored in the deferred local will be
781 // gc'd on its own.
782 if (_type == T_OBJECT) {
783 _value.l = (jobject) (JNIHandles::resolve_external_guard(_value.l));
784 }
785 // Re-read the vframe so we can see that it is deoptimized
786 // [ Only need because of assert in update_local() ]
787 _jvf = get_java_vframe();
788 ((compiledVFrame*)_jvf)->update_local(_type, _index, _value);
789 return;
790 }
791 StackValueCollection *locals = _jvf->locals();
792 HandleMark hm;
793
794 switch (_type) {
795 case T_INT: locals->set_int_at (_index, _value.i); break;
796 case T_LONG: locals->set_long_at (_index, _value.j); break;
797 case T_FLOAT: locals->set_float_at (_index, _value.f); break;
798 case T_DOUBLE: locals->set_double_at(_index, _value.d); break;
799 case T_OBJECT: {
800 Handle ob_h(JNIHandles::resolve_external_guard(_value.l));
801 locals->set_obj_at (_index, ob_h);
802 break;
803 }
804 default: ShouldNotReachHere();
805 }
806 _jvf->set_locals(locals);
807 } else {
808 if (_jvf->method()->is_native() && _jvf->is_compiled_frame()) {
809 assert(getting_receiver(), "Can only get here when getting receiver");
810 oop receiver = _jvf->fr().get_native_receiver();
811 _value.l = JNIHandles::make_local(_calling_thread, receiver);
812 } else {
813 StackValueCollection *locals = _jvf->locals();
814
815 if (locals->at(_index)->type() == T_CONFLICT) {
816 memset(&_value, 0, sizeof(_value));
817 _value.l = NULL;
818 return;
819 }
820
821 switch (_type) {
822 case T_INT: _value.i = locals->int_at (_index); break;
823 case T_LONG: _value.j = locals->long_at (_index); break;
824 case T_FLOAT: _value.f = locals->float_at (_index); break;
825 case T_DOUBLE: _value.d = locals->double_at(_index); break;
826 case T_OBJECT: {
827 // Wrap the oop to be returned in a local JNI handle since
828 // oops_do() no longer applies after doit() is finished.
829 oop obj = locals->obj_at(_index)();
830 _value.l = JNIHandles::make_local(_calling_thread, obj);
831 break;
832 }
833 default: ShouldNotReachHere();
834 }
835 }
836 }
837 }
838
839
840 bool VM_GetOrSetLocal::allow_nested_vm_operations() const {
841 return true; // May need to deoptimize
842 }
843
844
845 VM_GetReceiver::VM_GetReceiver(
846 JavaThread* thread, JavaThread* caller_thread, jint depth)
847 : VM_GetOrSetLocal(thread, caller_thread, depth, 0) {}
848
849 /////////////////////////////////////////////////////////////////////////////////////////
850
851 //
852 // class JvmtiSuspendControl - see comments in jvmtiImpl.hpp
853 //
854
855 bool JvmtiSuspendControl::suspend(JavaThread *java_thread) {
856 // external suspend should have caught suspending a thread twice
857
858 // Immediate suspension required for JPDA back-end so JVMTI agent threads do
859 // not deadlock due to later suspension on transitions while holding
860 // raw monitors. Passing true causes the immediate suspension.
861 // java_suspend() will catch threads in the process of exiting
862 // and will ignore them.
863 java_thread->java_suspend();
864
865 // It would be nice to have the following assertion in all the time,
866 // but it is possible for a racing resume request to have resumed
867 // this thread right after we suspended it. Temporarily enable this
868 // assertion if you are chasing a different kind of bug.
869 //
870 // assert(java_lang_Thread::thread(java_thread->threadObj()) == NULL ||
871 // java_thread->is_being_ext_suspended(), "thread is not suspended");
872
873 if (java_lang_Thread::thread(java_thread->threadObj()) == NULL) {
874 // check again because we can get delayed in java_suspend():
875 // the thread is in process of exiting.
876 return false;
877 }
878
879 return true;
880 }
881
882 bool JvmtiSuspendControl::resume(JavaThread *java_thread) {
883 // external suspend should have caught resuming a thread twice
884 assert(java_thread->is_being_ext_suspended(), "thread should be suspended");
885
886 // resume thread
887 {
888 // must always grab Threads_lock, see JVM_SuspendThread
889 MutexLocker ml(Threads_lock);
890 java_thread->java_resume();
891 }
892
893 return true;
894 }
895
896
897 void JvmtiSuspendControl::print() {
898 #ifndef PRODUCT
899 MutexLocker mu(Threads_lock);
900 ResourceMark rm;
901
902 tty->print("Suspended Threads: [");
903 for (JavaThread *thread = Threads::first(); thread != NULL; thread = thread->next()) {
904 #if JVMTI_TRACE
905 const char *name = JvmtiTrace::safe_get_thread_name(thread);
906 #else
907 const char *name = "";
908 #endif /*JVMTI_TRACE */
909 tty->print("%s(%c ", name, thread->is_being_ext_suspended() ? 'S' : '_');
910 if (!thread->has_last_Java_frame()) {
911 tty->print("no stack");
912 }
913 tty->print(") ");
914 }
915 tty->print_cr("]");
916 #endif
917 }
918
919 #ifndef KERNEL
920
921 JvmtiDeferredEvent JvmtiDeferredEvent::compiled_method_load_event(
922 nmethod* nm) {
923 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_COMPILED_METHOD_LOAD);
924 event._event_data.compiled_method_load = nm;
925 // Keep the nmethod alive until the ServiceThread can process
926 // this deferred event.
927 nmethodLocker::lock_nmethod(nm);
928 return event;
929 }
930
931 JvmtiDeferredEvent JvmtiDeferredEvent::compiled_method_unload_event(
932 nmethod* nm, jmethodID id, const void* code) {
933 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_COMPILED_METHOD_UNLOAD);
934 event._event_data.compiled_method_unload.nm = nm;
935 event._event_data.compiled_method_unload.method_id = id;
936 event._event_data.compiled_method_unload.code_begin = code;
937 // Keep the nmethod alive until the ServiceThread can process
938 // this deferred event. This will keep the memory for the
939 // generated code from being reused too early. We pass
940 // zombie_ok == true here so that our nmethod that was just
941 // made into a zombie can be locked.
942 nmethodLocker::lock_nmethod(nm, true /* zombie_ok */);
943 return event;
944 }
945
946 JvmtiDeferredEvent JvmtiDeferredEvent::dynamic_code_generated_event(
947 const char* name, const void* code_begin, const void* code_end) {
948 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_DYNAMIC_CODE_GENERATED);
949 // Need to make a copy of the name since we don't know how long
950 // the event poster will keep it around after we enqueue the
951 // deferred event and return. strdup() failure is handled in
952 // the post() routine below.
953 event._event_data.dynamic_code_generated.name = os::strdup(name);
954 event._event_data.dynamic_code_generated.code_begin = code_begin;
955 event._event_data.dynamic_code_generated.code_end = code_end;
956 return event;
957 }
958
959 void JvmtiDeferredEvent::post() {
960 assert(ServiceThread::is_service_thread(Thread::current()),
961 "Service thread must post enqueued events");
962 switch(_type) {
963 case TYPE_COMPILED_METHOD_LOAD: {
964 nmethod* nm = _event_data.compiled_method_load;
965 JvmtiExport::post_compiled_method_load(nm);
966 // done with the deferred event so unlock the nmethod
967 nmethodLocker::unlock_nmethod(nm);
968 break;
969 }
970 case TYPE_COMPILED_METHOD_UNLOAD: {
971 nmethod* nm = _event_data.compiled_method_unload.nm;
972 JvmtiExport::post_compiled_method_unload(
973 _event_data.compiled_method_unload.method_id,
974 _event_data.compiled_method_unload.code_begin);
975 // done with the deferred event so unlock the nmethod
976 nmethodLocker::unlock_nmethod(nm);
977 break;
978 }
979 case TYPE_DYNAMIC_CODE_GENERATED: {
980 JvmtiExport::post_dynamic_code_generated_internal(
981 // if strdup failed give the event a default name
982 (_event_data.dynamic_code_generated.name == NULL)
983 ? "unknown_code" : _event_data.dynamic_code_generated.name,
984 _event_data.dynamic_code_generated.code_begin,
985 _event_data.dynamic_code_generated.code_end);
986 if (_event_data.dynamic_code_generated.name != NULL) {
987 // release our copy
988 os::free((void *)_event_data.dynamic_code_generated.name);
989 }
990 break;
991 }
992 default:
993 ShouldNotReachHere();
994 }
995 }
996
997 JvmtiDeferredEventQueue::QueueNode* JvmtiDeferredEventQueue::_queue_tail = NULL;
998 JvmtiDeferredEventQueue::QueueNode* JvmtiDeferredEventQueue::_queue_head = NULL;
999
1000 volatile JvmtiDeferredEventQueue::QueueNode*
1001 JvmtiDeferredEventQueue::_pending_list = NULL;
1002
1003 bool JvmtiDeferredEventQueue::has_events() {
1004 assert(Service_lock->owned_by_self(), "Must own Service_lock");
1005 return _queue_head != NULL || _pending_list != NULL;
1006 }
1007
1008 void JvmtiDeferredEventQueue::enqueue(const JvmtiDeferredEvent& event) {
1009 assert(Service_lock->owned_by_self(), "Must own Service_lock");
1010
1011 process_pending_events();
1012
1013 // Events get added to the end of the queue (and are pulled off the front).
1014 QueueNode* node = new QueueNode(event);
1015 if (_queue_tail == NULL) {
1016 _queue_tail = _queue_head = node;
1017 } else {
1018 assert(_queue_tail->next() == NULL, "Must be the last element in the list");
1019 _queue_tail->set_next(node);
1020 _queue_tail = node;
1021 }
1022
1023 Service_lock->notify_all();
1024 assert((_queue_head == NULL) == (_queue_tail == NULL),
1025 "Inconsistent queue markers");
1026 }
1027
1028 JvmtiDeferredEvent JvmtiDeferredEventQueue::dequeue() {
1029 assert(Service_lock->owned_by_self(), "Must own Service_lock");
1030
1031 process_pending_events();
1032
1033 assert(_queue_head != NULL, "Nothing to dequeue");
1034
1035 if (_queue_head == NULL) {
1036 // Just in case this happens in product; it shouldn't but let's not crash
1037 return JvmtiDeferredEvent();
1038 }
1039
1040 QueueNode* node = _queue_head;
1041 _queue_head = _queue_head->next();
1042 if (_queue_head == NULL) {
1043 _queue_tail = NULL;
1044 }
1045
1046 assert((_queue_head == NULL) == (_queue_tail == NULL),
1047 "Inconsistent queue markers");
1048
1049 JvmtiDeferredEvent event = node->event();
1050 delete node;
1051 return event;
1052 }
1053
1054 void JvmtiDeferredEventQueue::add_pending_event(
1055 const JvmtiDeferredEvent& event) {
1056
1057 QueueNode* node = new QueueNode(event);
1058
1059 bool success = false;
1060 QueueNode* prev_value = (QueueNode*)_pending_list;
1061 do {
1062 node->set_next(prev_value);
1063 prev_value = (QueueNode*)Atomic::cmpxchg_ptr(
1064 (void*)node, (volatile void*)&_pending_list, (void*)node->next());
1065 } while (prev_value != node->next());
1066 }
1067
1068 // This method transfers any events that were added by someone NOT holding
1069 // the lock into the mainline queue.
1070 void JvmtiDeferredEventQueue::process_pending_events() {
1071 assert(Service_lock->owned_by_self(), "Must own Service_lock");
1072
1073 if (_pending_list != NULL) {
1074 QueueNode* head =
1075 (QueueNode*)Atomic::xchg_ptr(NULL, (volatile void*)&_pending_list);
1076
1077 assert((_queue_head == NULL) == (_queue_tail == NULL),
1078 "Inconsistent queue markers");
1079
1080 if (head != NULL) {
1081 // Since we've treated the pending list as a stack (with newer
1082 // events at the beginning), we need to join the bottom of the stack
1083 // with the 'tail' of the queue in order to get the events in the
1084 // right order. We do this by reversing the pending list and appending
1085 // it to the queue.
1086
1087 QueueNode* new_tail = head;
1088 QueueNode* new_head = NULL;
1089
1090 // This reverses the list
1091 QueueNode* prev = new_tail;
1092 QueueNode* node = new_tail->next();
1093 new_tail->set_next(NULL);
1094 while (node != NULL) {
1095 QueueNode* next = node->next();
1096 node->set_next(prev);
1097 prev = node;
1098 node = next;
1099 }
1100 new_head = prev;
1101
1102 // Now append the new list to the queue
1103 if (_queue_tail != NULL) {
1104 _queue_tail->set_next(new_head);
1105 } else { // _queue_head == NULL
1106 _queue_head = new_head;
1107 }
1108 _queue_tail = new_tail;
1109 }
1110 }
1111 }
1112
1113 #endif // ndef KERNEL