1 /*
2 * Copyright (c) 2003, 2014, 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 "interpreter/oopMapCache.hpp"
29 #include "jvmtifiles/jvmtiEnv.hpp"
30 #include "memory/resourceArea.hpp"
31 #include "oops/instanceKlass.hpp"
32 #include "prims/jvmtiAgentThread.hpp"
33 #include "prims/jvmtiEventController.inline.hpp"
34 #include "prims/jvmtiImpl.hpp"
35 #include "prims/jvmtiRedefineClasses.hpp"
36 #include "runtime/atomic.hpp"
37 #include "runtime/deoptimization.hpp"
38 #include "runtime/handles.hpp"
39 #include "runtime/handles.inline.hpp"
40 #include "runtime/interfaceSupport.hpp"
41 #include "runtime/javaCalls.hpp"
42 #include "runtime/os.hpp"
43 #include "runtime/serviceThread.hpp"
44 #include "runtime/signature.hpp"
45 #include "runtime/thread.inline.hpp"
46 #include "runtime/vframe.hpp"
47 #include "runtime/vframe_hp.hpp"
48 #include "runtime/vm_operations.hpp"
49 #include "utilities/exceptions.hpp"
50
51 //
52 // class JvmtiAgentThread
53 //
54 // JavaThread used to wrap a thread started by an agent
55 // using the JVMTI method RunAgentThread.
56 //
57
58 JvmtiAgentThread::JvmtiAgentThread(JvmtiEnv* env, jvmtiStartFunction start_fn, const void *start_arg)
59 : JavaThread(start_function_wrapper) {
60 _env = env;
61 _start_fn = start_fn;
62 _start_arg = start_arg;
63 }
64
65 void
66 JvmtiAgentThread::start_function_wrapper(JavaThread *thread, TRAPS) {
67 // It is expected that any Agent threads will be created as
68 // Java Threads. If this is the case, notification of the creation
69 // of the thread is given in JavaThread::thread_main().
70 assert(thread->is_Java_thread(), "debugger thread should be a Java Thread");
71 assert(thread == JavaThread::current(), "sanity check");
72
73 JvmtiAgentThread *dthread = (JvmtiAgentThread *)thread;
74 dthread->call_start_function();
75 }
76
77 void
78 JvmtiAgentThread::call_start_function() {
79 ThreadToNativeFromVM transition(this);
80 _start_fn(_env->jvmti_external(), jni_environment(), (void*)_start_arg);
81 }
82
83
84 //
85 // class GrowableCache - private methods
86 //
87
88 void GrowableCache::recache() {
89 int len = _elements->length();
90
91 FREE_C_HEAP_ARRAY(address, _cache, mtInternal);
92 _cache = NEW_C_HEAP_ARRAY(address,len+1, mtInternal);
93
94 for (int i=0; i<len; i++) {
95 _cache[i] = _elements->at(i)->getCacheValue();
96 //
97 // The cache entry has gone bad. Without a valid frame pointer
98 // value, the entry is useless so we simply delete it in product
99 // mode. The call to remove() will rebuild the cache again
100 // without the bad entry.
101 //
102 if (_cache[i] == NULL) {
103 assert(false, "cannot recache NULL elements");
104 remove(i);
105 return;
106 }
107 }
108 _cache[len] = NULL;
109
110 _listener_fun(_this_obj,_cache);
111 }
112
113 bool GrowableCache::equals(void* v, GrowableElement *e2) {
114 GrowableElement *e1 = (GrowableElement *) v;
115 assert(e1 != NULL, "e1 != NULL");
116 assert(e2 != NULL, "e2 != NULL");
117
118 return e1->equals(e2);
119 }
120
121 //
122 // class GrowableCache - public methods
123 //
124
125 GrowableCache::GrowableCache() {
126 _this_obj = NULL;
127 _listener_fun = NULL;
128 _elements = NULL;
129 _cache = NULL;
130 }
131
132 GrowableCache::~GrowableCache() {
133 clear();
134 delete _elements;
135 FREE_C_HEAP_ARRAY(address, _cache, mtInternal);
136 }
137
138 void GrowableCache::initialize(void *this_obj, void listener_fun(void *, address*) ) {
139 _this_obj = this_obj;
140 _listener_fun = listener_fun;
141 _elements = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<GrowableElement*>(5,true);
142 recache();
143 }
144
145 // number of elements in the collection
146 int GrowableCache::length() {
147 return _elements->length();
148 }
149
150 // get the value of the index element in the collection
151 GrowableElement* GrowableCache::at(int index) {
152 GrowableElement *e = (GrowableElement *) _elements->at(index);
153 assert(e != NULL, "e != NULL");
154 return e;
155 }
156
157 int GrowableCache::find(GrowableElement* e) {
158 return _elements->find(e, GrowableCache::equals);
159 }
160
161 // append a copy of the element to the end of the collection
162 void GrowableCache::append(GrowableElement* e) {
163 GrowableElement *new_e = e->clone();
164 _elements->append(new_e);
165 recache();
166 }
167
168 // insert a copy of the element using lessthan()
169 void GrowableCache::insert(GrowableElement* e) {
170 GrowableElement *new_e = e->clone();
171 _elements->append(new_e);
172
173 int n = length()-2;
174 for (int i=n; i>=0; i--) {
175 GrowableElement *e1 = _elements->at(i);
176 GrowableElement *e2 = _elements->at(i+1);
177 if (e2->lessThan(e1)) {
178 _elements->at_put(i+1, e1);
179 _elements->at_put(i, e2);
180 }
181 }
182
183 recache();
184 }
185
186 // remove the element at index
187 void GrowableCache::remove (int index) {
188 GrowableElement *e = _elements->at(index);
189 assert(e != NULL, "e != NULL");
190 _elements->remove(e);
191 delete e;
192 recache();
193 }
194
195 // clear out all elements, release all heap space and
196 // let our listener know that things have changed.
197 void GrowableCache::clear() {
198 int len = _elements->length();
199 for (int i=0; i<len; i++) {
200 delete _elements->at(i);
201 }
202 _elements->clear();
203 recache();
204 }
205
206 void GrowableCache::oops_do(OopClosure* f) {
207 int len = _elements->length();
208 for (int i=0; i<len; i++) {
209 GrowableElement *e = _elements->at(i);
210 e->oops_do(f);
211 }
212 }
213
214 void GrowableCache::metadata_do(void f(Metadata*)) {
215 int len = _elements->length();
216 for (int i=0; i<len; i++) {
217 GrowableElement *e = _elements->at(i);
218 e->metadata_do(f);
219 }
220 }
221
222 void GrowableCache::gc_epilogue() {
223 int len = _elements->length();
224 for (int i=0; i<len; i++) {
225 _cache[i] = _elements->at(i)->getCacheValue();
226 }
227 }
228
229 //
230 // class JvmtiBreakpoint
231 //
232
233 JvmtiBreakpoint::JvmtiBreakpoint() {
234 _method = NULL;
235 _bci = 0;
236 _class_holder = NULL;
237 }
238
239 JvmtiBreakpoint::JvmtiBreakpoint(Method* m_method, jlocation location) {
240 _method = m_method;
241 _class_holder = _method->method_holder()->klass_holder();
242 #ifdef CHECK_UNHANDLED_OOPS
243 // _class_holder can't be wrapped in a Handle, because JvmtiBreakpoints are
244 // sometimes allocated on the heap.
245 //
246 // The code handling JvmtiBreakpoints allocated on the stack can't be
247 // interrupted by a GC until _class_holder is reachable by the GC via the
248 // oops_do method.
249 Thread::current()->allow_unhandled_oop(&_class_holder);
250 #endif // CHECK_UNHANDLED_OOPS
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_holder = bp._class_holder;
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 PreviousVersionNodes.
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 // search previous versions if they exist
294 PreviousVersionWalker pvw(thread, (InstanceKlass *)ikh());
295 for (PreviousVersionNode * pv_node = pvw.next_previous_version();
296 pv_node != NULL; pv_node = pvw.next_previous_version()) {
297 GrowableArray<Method*>* methods = pv_node->prev_EMCP_methods();
298
299 if (methods == NULL) {
300 // We have run into a PreviousVersion generation where
301 // all methods were made obsolete during that generation's
302 // RedefineClasses() operation. At the time of that
303 // operation, all EMCP methods were flushed so we don't
304 // have to go back any further.
305 //
306 // A NULL methods array is different than an empty methods
307 // array. We cannot infer any optimizations about older
308 // generations from an empty methods array for the current
309 // generation.
310 break;
311 }
312
313 for (int i = methods->length() - 1; i >= 0; i--) {
314 Method* method = methods->at(i);
315 // obsolete methods that are running are not deleted from
316 // previous version array, but they are skipped here.
317 if (!method->is_obsolete() &&
318 method->name() == m_name &&
319 method->signature() == m_signature) {
320 RC_TRACE(0x00000800, ("%sing breakpoint in %s(%s)",
321 meth_act == &Method::set_breakpoint ? "sett" : "clear",
322 method->name()->as_C_string(),
323 method->signature()->as_C_string()));
324
325 (method->*meth_act)(_bci);
326 break;
327 }
328 }
329 }
330 }
331
332 void JvmtiBreakpoint::set() {
333 each_method_version_do(&Method::set_breakpoint);
334 }
335
336 void JvmtiBreakpoint::clear() {
337 each_method_version_do(&Method::clear_breakpoint);
338 }
339
340 void JvmtiBreakpoint::print() {
341 #ifndef PRODUCT
342 const char *class_name = (_method == NULL) ? "NULL" : _method->klass_name()->as_C_string();
343 const char *method_name = (_method == NULL) ? "NULL" : _method->name()->as_C_string();
344
345 tty->print("Breakpoint(%s,%s,%d,%p)",class_name, method_name, _bci, getBcp());
346 #endif
347 }
348
349
350 //
351 // class VM_ChangeBreakpoints
352 //
353 // Modify the Breakpoints data structure at a safepoint
354 //
355
356 void VM_ChangeBreakpoints::doit() {
357 switch (_operation) {
358 case SET_BREAKPOINT:
359 _breakpoints->set_at_safepoint(*_bp);
360 break;
361 case CLEAR_BREAKPOINT:
362 _breakpoints->clear_at_safepoint(*_bp);
363 break;
364 default:
365 assert(false, "Unknown operation");
366 }
367 }
368
369 void VM_ChangeBreakpoints::oops_do(OopClosure* f) {
370 // The JvmtiBreakpoints in _breakpoints will be visited via
371 // JvmtiExport::oops_do.
372 if (_bp != NULL) {
373 _bp->oops_do(f);
374 }
375 }
376
377 void VM_ChangeBreakpoints::metadata_do(void f(Metadata*)) {
378 // Walk metadata in breakpoints to keep from being deallocated with RedefineClasses
379 if (_bp != NULL) {
380 _bp->metadata_do(f);
381 }
382 }
383
384 //
385 // class JvmtiBreakpoints
386 //
387 // a JVMTI internal collection of JvmtiBreakpoint
388 //
389
390 JvmtiBreakpoints::JvmtiBreakpoints(void listener_fun(void *,address *)) {
391 _bps.initialize(this,listener_fun);
392 }
393
394 JvmtiBreakpoints:: ~JvmtiBreakpoints() {}
395
396 void JvmtiBreakpoints::oops_do(OopClosure* f) {
397 _bps.oops_do(f);
398 }
399
400 void JvmtiBreakpoints::metadata_do(void f(Metadata*)) {
401 _bps.metadata_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->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(Klass* 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::metadata_do(void f(Metadata*)) {
523 if (_jvmti_breakpoints != NULL) {
524 _jvmti_breakpoints->metadata_do(f);
525 }
526 }
527
528 void JvmtiCurrentBreakpoints::gc_epilogue() {
529 if (_jvmti_breakpoints != NULL) {
530 _jvmti_breakpoints->gc_epilogue();
531 }
532 }
533
534 ///////////////////////////////////////////////////////////////
535 //
536 // class VM_GetOrSetLocal
537 //
538
539 // Constructor for non-object getter
540 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, jint depth, int index, BasicType type)
541 : _thread(thread)
542 , _calling_thread(NULL)
543 , _depth(depth)
544 , _index(index)
545 , _type(type)
546 , _set(false)
547 , _jvf(NULL)
548 , _result(JVMTI_ERROR_NONE)
549 {
550 }
551
552 // Constructor for object or non-object setter
553 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, jint depth, int index, BasicType type, jvalue value)
554 : _thread(thread)
555 , _calling_thread(NULL)
556 , _depth(depth)
557 , _index(index)
558 , _type(type)
559 , _value(value)
560 , _set(true)
561 , _jvf(NULL)
562 , _result(JVMTI_ERROR_NONE)
563 {
564 }
565
566 // Constructor for object getter
567 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, JavaThread* calling_thread, jint depth, int index)
568 : _thread(thread)
569 , _calling_thread(calling_thread)
570 , _depth(depth)
571 , _index(index)
572 , _type(T_OBJECT)
573 , _set(false)
574 , _jvf(NULL)
575 , _result(JVMTI_ERROR_NONE)
576 {
577 }
578
579 vframe *VM_GetOrSetLocal::get_vframe() {
580 if (!_thread->has_last_Java_frame()) {
581 return NULL;
582 }
583 RegisterMap reg_map(_thread);
584 vframe *vf = _thread->last_java_vframe(®_map);
585 int d = 0;
586 while ((vf != NULL) && (d < _depth)) {
587 vf = vf->java_sender();
588 d++;
589 }
590 return vf;
591 }
592
593 javaVFrame *VM_GetOrSetLocal::get_java_vframe() {
594 vframe* vf = get_vframe();
595 if (vf == NULL) {
596 _result = JVMTI_ERROR_NO_MORE_FRAMES;
597 return NULL;
598 }
599 javaVFrame *jvf = (javaVFrame*)vf;
600
601 if (!vf->is_java_frame()) {
602 _result = JVMTI_ERROR_OPAQUE_FRAME;
603 return NULL;
604 }
605 return jvf;
606 }
607
608 // Check that the klass is assignable to a type with the given signature.
609 // Another solution could be to use the function Klass::is_subtype_of(type).
610 // But the type class can be forced to load/initialize eagerly in such a case.
611 // This may cause unexpected consequences like CFLH or class-init JVMTI events.
612 // It is better to avoid such a behavior.
613 bool VM_GetOrSetLocal::is_assignable(const char* ty_sign, Klass* klass, Thread* thread) {
614 assert(ty_sign != NULL, "type signature must not be NULL");
615 assert(thread != NULL, "thread must not be NULL");
616 assert(klass != NULL, "klass must not be NULL");
617
618 int len = (int) strlen(ty_sign);
619 if (ty_sign[0] == 'L' && ty_sign[len-1] == ';') { // Need pure class/interface name
620 ty_sign++;
621 len -= 2;
622 }
623 TempNewSymbol ty_sym = SymbolTable::new_symbol(ty_sign, len, thread);
624 if (klass->name() == ty_sym) {
625 return true;
626 }
627 // Compare primary supers
628 int super_depth = klass->super_depth();
629 int idx;
630 for (idx = 0; idx < super_depth; idx++) {
631 if (klass->primary_super_of_depth(idx)->name() == ty_sym) {
632 return true;
633 }
634 }
635 // Compare secondary supers
636 Array<Klass*>* sec_supers = klass->secondary_supers();
637 for (idx = 0; idx < sec_supers->length(); idx++) {
638 if (((Klass*) sec_supers->at(idx))->name() == ty_sym) {
639 return true;
640 }
641 }
642 return false;
643 }
644
645 // Checks error conditions:
646 // JVMTI_ERROR_INVALID_SLOT
647 // JVMTI_ERROR_TYPE_MISMATCH
648 // Returns: 'true' - everything is Ok, 'false' - error code
649
650 bool VM_GetOrSetLocal::check_slot_type(javaVFrame* jvf) {
651 Method* method_oop = jvf->method();
652 if (!method_oop->has_localvariable_table()) {
653 // Just to check index boundaries
654 jint extra_slot = (_type == T_LONG || _type == T_DOUBLE) ? 1 : 0;
655 if (_index < 0 || _index + extra_slot >= method_oop->max_locals()) {
656 _result = JVMTI_ERROR_INVALID_SLOT;
657 return false;
658 }
659 return true;
660 }
661
662 jint num_entries = method_oop->localvariable_table_length();
663 if (num_entries == 0) {
664 _result = JVMTI_ERROR_INVALID_SLOT;
665 return false; // There are no slots
666 }
667 int signature_idx = -1;
668 int vf_bci = jvf->bci();
669 LocalVariableTableElement* table = method_oop->localvariable_table_start();
670 for (int i = 0; i < num_entries; i++) {
671 int start_bci = table[i].start_bci;
672 int end_bci = start_bci + table[i].length;
673
674 // Here we assume that locations of LVT entries
675 // with the same slot number cannot be overlapped
676 if (_index == (jint) table[i].slot && start_bci <= vf_bci && vf_bci <= end_bci) {
677 signature_idx = (int) table[i].descriptor_cp_index;
678 break;
679 }
680 }
681 if (signature_idx == -1) {
682 _result = JVMTI_ERROR_INVALID_SLOT;
683 return false; // Incorrect slot index
684 }
685 Symbol* sign_sym = method_oop->constants()->symbol_at(signature_idx);
686 const char* signature = (const char *) sign_sym->as_utf8();
687 BasicType slot_type = char2type(signature[0]);
688
689 switch (slot_type) {
690 case T_BYTE:
691 case T_SHORT:
692 case T_CHAR:
693 case T_BOOLEAN:
694 slot_type = T_INT;
695 break;
696 case T_ARRAY:
697 slot_type = T_OBJECT;
698 break;
699 };
700 if (_type != slot_type) {
701 _result = JVMTI_ERROR_TYPE_MISMATCH;
702 return false;
703 }
704
705 jobject jobj = _value.l;
706 if (_set && slot_type == T_OBJECT && jobj != NULL) { // NULL reference is allowed
707 // Check that the jobject class matches the return type signature.
708 JavaThread* cur_thread = JavaThread::current();
709 HandleMark hm(cur_thread);
710
711 Handle obj = Handle(cur_thread, JNIHandles::resolve_external_guard(jobj));
712 NULL_CHECK(obj, (_result = JVMTI_ERROR_INVALID_OBJECT, false));
713 KlassHandle ob_kh = KlassHandle(cur_thread, obj->klass());
714 NULL_CHECK(ob_kh, (_result = JVMTI_ERROR_INVALID_OBJECT, false));
715
716 if (!is_assignable(signature, ob_kh(), cur_thread)) {
717 _result = JVMTI_ERROR_TYPE_MISMATCH;
718 return false;
719 }
720 }
721 return true;
722 }
723
724 static bool can_be_deoptimized(vframe* vf) {
725 return (vf->is_compiled_frame() && vf->fr().can_be_deoptimized());
726 }
727
728 bool VM_GetOrSetLocal::doit_prologue() {
729 _jvf = get_java_vframe();
730 NULL_CHECK(_jvf, false);
731
732 if (_jvf->method()->is_native()) {
733 if (getting_receiver() && !_jvf->method()->is_static()) {
734 return true;
735 } else {
736 _result = JVMTI_ERROR_OPAQUE_FRAME;
737 return false;
738 }
739 }
740
741 if (!check_slot_type(_jvf)) {
742 return false;
743 }
744 return true;
745 }
746
747 void VM_GetOrSetLocal::doit() {
748 InterpreterOopMap oop_mask;
749 _jvf->method()->mask_for(_jvf->bci(), &oop_mask);
750 if (oop_mask.is_dead(_index)) {
751 // The local can be invalid and uninitialized in the scope of current bci
752 _result = JVMTI_ERROR_INVALID_SLOT;
753 return;
754 }
755 if (_set) {
756 // Force deoptimization of frame if compiled because it's
757 // possible the compiler emitted some locals as constant values,
758 // meaning they are not mutable.
759 if (can_be_deoptimized(_jvf)) {
760
761 // Schedule deoptimization so that eventually the local
762 // update will be written to an interpreter frame.
763 Deoptimization::deoptimize_frame(_jvf->thread(), _jvf->fr().id());
764
765 // Now store a new value for the local which will be applied
766 // once deoptimization occurs. Note however that while this
767 // write is deferred until deoptimization actually happens
768 // can vframe created after this point will have its locals
769 // reflecting this update so as far as anyone can see the
770 // write has already taken place.
771
772 // If we are updating an oop then get the oop from the handle
773 // since the handle will be long gone by the time the deopt
774 // happens. The oop stored in the deferred local will be
775 // gc'd on its own.
776 if (_type == T_OBJECT) {
777 _value.l = (jobject) (JNIHandles::resolve_external_guard(_value.l));
778 }
779 // Re-read the vframe so we can see that it is deoptimized
780 // [ Only need because of assert in update_local() ]
781 _jvf = get_java_vframe();
782 ((compiledVFrame*)_jvf)->update_local(_type, _index, _value);
783 return;
784 }
785 StackValueCollection *locals = _jvf->locals();
786 HandleMark hm;
787
788 switch (_type) {
789 case T_INT: locals->set_int_at (_index, _value.i); break;
790 case T_LONG: locals->set_long_at (_index, _value.j); break;
791 case T_FLOAT: locals->set_float_at (_index, _value.f); break;
792 case T_DOUBLE: locals->set_double_at(_index, _value.d); break;
793 case T_OBJECT: {
794 Handle ob_h(JNIHandles::resolve_external_guard(_value.l));
795 locals->set_obj_at (_index, ob_h);
796 break;
797 }
798 default: ShouldNotReachHere();
799 }
800 _jvf->set_locals(locals);
801 } else {
802 if (_jvf->method()->is_native() && _jvf->is_compiled_frame()) {
803 assert(getting_receiver(), "Can only get here when getting receiver");
804 oop receiver = _jvf->fr().get_native_receiver();
805 _value.l = JNIHandles::make_local(_calling_thread, receiver);
806 } else {
807 StackValueCollection *locals = _jvf->locals();
808
809 if (locals->at(_index)->type() == T_CONFLICT) {
810 memset(&_value, 0, sizeof(_value));
811 _value.l = NULL;
812 return;
813 }
814
815 switch (_type) {
816 case T_INT: _value.i = locals->int_at (_index); break;
817 case T_LONG: _value.j = locals->long_at (_index); break;
818 case T_FLOAT: _value.f = locals->float_at (_index); break;
819 case T_DOUBLE: _value.d = locals->double_at(_index); break;
820 case T_OBJECT: {
821 // Wrap the oop to be returned in a local JNI handle since
822 // oops_do() no longer applies after doit() is finished.
823 oop obj = locals->obj_at(_index)();
824 _value.l = JNIHandles::make_local(_calling_thread, obj);
825 break;
826 }
827 default: ShouldNotReachHere();
828 }
829 }
830 }
831 }
832
833
834 bool VM_GetOrSetLocal::allow_nested_vm_operations() const {
835 return true; // May need to deoptimize
836 }
837
838
839 VM_GetReceiver::VM_GetReceiver(
840 JavaThread* thread, JavaThread* caller_thread, jint depth)
841 : VM_GetOrSetLocal(thread, caller_thread, depth, 0) {}
842
843 /////////////////////////////////////////////////////////////////////////////////////////
844
845 //
846 // class JvmtiSuspendControl - see comments in jvmtiImpl.hpp
847 //
848
849 bool JvmtiSuspendControl::suspend(JavaThread *java_thread) {
850 // external suspend should have caught suspending a thread twice
851
852 // Immediate suspension required for JPDA back-end so JVMTI agent threads do
853 // not deadlock due to later suspension on transitions while holding
854 // raw monitors. Passing true causes the immediate suspension.
855 // java_suspend() will catch threads in the process of exiting
856 // and will ignore them.
857 java_thread->java_suspend();
858
859 // It would be nice to have the following assertion in all the time,
860 // but it is possible for a racing resume request to have resumed
861 // this thread right after we suspended it. Temporarily enable this
862 // assertion if you are chasing a different kind of bug.
863 //
864 // assert(java_lang_Thread::thread(java_thread->threadObj()) == NULL ||
865 // java_thread->is_being_ext_suspended(), "thread is not suspended");
866
867 if (java_lang_Thread::thread(java_thread->threadObj()) == NULL) {
868 // check again because we can get delayed in java_suspend():
869 // the thread is in process of exiting.
870 return false;
871 }
872
873 return true;
874 }
875
876 bool JvmtiSuspendControl::resume(JavaThread *java_thread) {
877 // external suspend should have caught resuming a thread twice
878 assert(java_thread->is_being_ext_suspended(), "thread should be suspended");
879
880 // resume thread
881 {
882 // must always grab Threads_lock, see JVM_SuspendThread
883 MutexLocker ml(Threads_lock);
884 java_thread->java_resume();
885 }
886
887 return true;
888 }
889
890
891 void JvmtiSuspendControl::print() {
892 #ifndef PRODUCT
893 MutexLocker mu(Threads_lock);
894 ResourceMark rm;
895
896 tty->print("Suspended Threads: [");
897 for (JavaThread *thread = Threads::first(); thread != NULL; thread = thread->next()) {
898 #ifdef JVMTI_TRACE
899 const char *name = JvmtiTrace::safe_get_thread_name(thread);
900 #else
901 const char *name = "";
902 #endif /*JVMTI_TRACE */
903 tty->print("%s(%c ", name, thread->is_being_ext_suspended() ? 'S' : '_');
904 if (!thread->has_last_Java_frame()) {
905 tty->print("no stack");
906 }
907 tty->print(") ");
908 }
909 tty->print_cr("]");
910 #endif
911 }
912
913 JvmtiDeferredEvent JvmtiDeferredEvent::compiled_method_load_event(
914 nmethod* nm) {
915 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_COMPILED_METHOD_LOAD);
916 event._event_data.compiled_method_load = nm;
917 // Keep the nmethod alive until the ServiceThread can process
918 // this deferred event.
919 nmethodLocker::lock_nmethod(nm);
920 return event;
921 }
922
923 JvmtiDeferredEvent JvmtiDeferredEvent::compiled_method_unload_event(
924 nmethod* nm, jmethodID id, const void* code) {
925 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_COMPILED_METHOD_UNLOAD);
926 event._event_data.compiled_method_unload.nm = nm;
927 event._event_data.compiled_method_unload.method_id = id;
928 event._event_data.compiled_method_unload.code_begin = code;
929 // Keep the nmethod alive until the ServiceThread can process
930 // this deferred event. This will keep the memory for the
931 // generated code from being reused too early. We pass
932 // zombie_ok == true here so that our nmethod that was just
933 // made into a zombie can be locked.
934 nmethodLocker::lock_nmethod(nm, true /* zombie_ok */);
935 return event;
936 }
937
938 JvmtiDeferredEvent JvmtiDeferredEvent::dynamic_code_generated_event(
939 const char* name, const void* code_begin, const void* code_end) {
940 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_DYNAMIC_CODE_GENERATED);
941 // Need to make a copy of the name since we don't know how long
942 // the event poster will keep it around after we enqueue the
943 // deferred event and return. strdup() failure is handled in
944 // the post() routine below.
945 event._event_data.dynamic_code_generated.name = os::strdup(name);
946 event._event_data.dynamic_code_generated.code_begin = code_begin;
947 event._event_data.dynamic_code_generated.code_end = code_end;
948 return event;
949 }
950
951 void JvmtiDeferredEvent::post() {
952 assert(ServiceThread::is_service_thread(Thread::current()),
953 "Service thread must post enqueued events");
954 switch(_type) {
955 case TYPE_COMPILED_METHOD_LOAD: {
956 nmethod* nm = _event_data.compiled_method_load;
957 JvmtiExport::post_compiled_method_load(nm);
958 // done with the deferred event so unlock the nmethod
959 nmethodLocker::unlock_nmethod(nm);
960 break;
961 }
962 case TYPE_COMPILED_METHOD_UNLOAD: {
963 nmethod* nm = _event_data.compiled_method_unload.nm;
964 JvmtiExport::post_compiled_method_unload(
965 _event_data.compiled_method_unload.method_id,
966 _event_data.compiled_method_unload.code_begin);
967 // done with the deferred event so unlock the nmethod
968 nmethodLocker::unlock_nmethod(nm);
969 break;
970 }
971 case TYPE_DYNAMIC_CODE_GENERATED: {
972 JvmtiExport::post_dynamic_code_generated_internal(
973 // if strdup failed give the event a default name
974 (_event_data.dynamic_code_generated.name == NULL)
975 ? "unknown_code" : _event_data.dynamic_code_generated.name,
976 _event_data.dynamic_code_generated.code_begin,
977 _event_data.dynamic_code_generated.code_end);
978 if (_event_data.dynamic_code_generated.name != NULL) {
979 // release our copy
980 os::free((void *)_event_data.dynamic_code_generated.name);
981 }
982 break;
983 }
984 default:
985 ShouldNotReachHere();
986 }
987 }
988
989 JvmtiDeferredEventQueue::QueueNode* JvmtiDeferredEventQueue::_queue_tail = NULL;
990 JvmtiDeferredEventQueue::QueueNode* JvmtiDeferredEventQueue::_queue_head = NULL;
991
992 volatile JvmtiDeferredEventQueue::QueueNode*
993 JvmtiDeferredEventQueue::_pending_list = NULL;
994
995 bool JvmtiDeferredEventQueue::has_events() {
996 assert(Service_lock->owned_by_self(), "Must own Service_lock");
997 return _queue_head != NULL || _pending_list != NULL;
998 }
999
1000 void JvmtiDeferredEventQueue::enqueue(const JvmtiDeferredEvent& event) {
1001 assert(Service_lock->owned_by_self(), "Must own Service_lock");
1002
1003 process_pending_events();
1004
1005 // Events get added to the end of the queue (and are pulled off the front).
1006 QueueNode* node = new QueueNode(event);
1007 if (_queue_tail == NULL) {
1008 _queue_tail = _queue_head = node;
1009 } else {
1010 assert(_queue_tail->next() == NULL, "Must be the last element in the list");
1011 _queue_tail->set_next(node);
1012 _queue_tail = node;
1013 }
1014
1015 Service_lock->notify_all();
1016 assert((_queue_head == NULL) == (_queue_tail == NULL),
1017 "Inconsistent queue markers");
1018 }
1019
1020 JvmtiDeferredEvent JvmtiDeferredEventQueue::dequeue() {
1021 assert(Service_lock->owned_by_self(), "Must own Service_lock");
1022
1023 process_pending_events();
1024
1025 assert(_queue_head != NULL, "Nothing to dequeue");
1026
1027 if (_queue_head == NULL) {
1028 // Just in case this happens in product; it shouldn't but let's not crash
1029 return JvmtiDeferredEvent();
1030 }
1031
1032 QueueNode* node = _queue_head;
1033 _queue_head = _queue_head->next();
1034 if (_queue_head == NULL) {
1035 _queue_tail = NULL;
1036 }
1037
1038 assert((_queue_head == NULL) == (_queue_tail == NULL),
1039 "Inconsistent queue markers");
1040
1041 JvmtiDeferredEvent event = node->event();
1042 delete node;
1043 return event;
1044 }
1045
1046 void JvmtiDeferredEventQueue::add_pending_event(
1047 const JvmtiDeferredEvent& event) {
1048
1049 QueueNode* node = new QueueNode(event);
1050
1051 bool success = false;
1052 QueueNode* prev_value = (QueueNode*)_pending_list;
1053 do {
1054 node->set_next(prev_value);
1055 prev_value = (QueueNode*)Atomic::cmpxchg_ptr(
1056 (void*)node, (volatile void*)&_pending_list, (void*)node->next());
1057 } while (prev_value != node->next());
1058 }
1059
1060 // This method transfers any events that were added by someone NOT holding
1061 // the lock into the mainline queue.
1062 void JvmtiDeferredEventQueue::process_pending_events() {
1063 assert(Service_lock->owned_by_self(), "Must own Service_lock");
1064
1065 if (_pending_list != NULL) {
1066 QueueNode* head =
1067 (QueueNode*)Atomic::xchg_ptr(NULL, (volatile void*)&_pending_list);
1068
1069 assert((_queue_head == NULL) == (_queue_tail == NULL),
1070 "Inconsistent queue markers");
1071
1072 if (head != NULL) {
1073 // Since we've treated the pending list as a stack (with newer
1074 // events at the beginning), we need to join the bottom of the stack
1075 // with the 'tail' of the queue in order to get the events in the
1076 // right order. We do this by reversing the pending list and appending
1077 // it to the queue.
1078
1079 QueueNode* new_tail = head;
1080 QueueNode* new_head = NULL;
1081
1082 // This reverses the list
1083 QueueNode* prev = new_tail;
1084 QueueNode* node = new_tail->next();
1085 new_tail->set_next(NULL);
1086 while (node != NULL) {
1087 QueueNode* next = node->next();
1088 node->set_next(prev);
1089 prev = node;
1090 node = next;
1091 }
1092 new_head = prev;
1093
1094 // Now append the new list to the queue
1095 if (_queue_tail != NULL) {
1096 _queue_tail->set_next(new_head);
1097 } else { // _queue_head == NULL
1098 _queue_head = new_head;
1099 }
1100 _queue_tail = new_tail;
1101 }
1102 }
1103 }