1 /*
2 * Copyright (c) 2003, 2018, 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 "logging/log.hpp"
31 #include "logging/logStream.hpp"
32 #include "memory/allocation.inline.hpp"
33 #include "memory/resourceArea.hpp"
34 #include "oops/instanceKlass.hpp"
35 #include "oops/oop.inline.hpp"
36 #include "prims/jvmtiAgentThread.hpp"
37 #include "prims/jvmtiEventController.inline.hpp"
38 #include "prims/jvmtiImpl.hpp"
39 #include "prims/jvmtiRedefineClasses.hpp"
40 #include "runtime/atomic.hpp"
41 #include "runtime/deoptimization.hpp"
42 #include "runtime/handles.hpp"
43 #include "runtime/handles.inline.hpp"
44 #include "runtime/interfaceSupport.inline.hpp"
45 #include "runtime/javaCalls.hpp"
46 #include "runtime/os.hpp"
47 #include "runtime/serviceThread.hpp"
48 #include "runtime/signature.hpp"
49 #include "runtime/thread.inline.hpp"
50 #include "runtime/threadSMR.hpp"
51 #include "runtime/vframe.hpp"
52 #include "runtime/vframe_hp.hpp"
53 #include "runtime/vm_operations.hpp"
54 #include "utilities/exceptions.hpp"
55
56 //
57 // class JvmtiAgentThread
58 //
59 // JavaThread used to wrap a thread started by an agent
60 // using the JVMTI method RunAgentThread.
61 //
62
63 JvmtiAgentThread::JvmtiAgentThread(JvmtiEnv* env, jvmtiStartFunction start_fn, const void *start_arg)
64 : JavaThread(start_function_wrapper) {
65 _env = env;
66 _start_fn = start_fn;
67 _start_arg = start_arg;
68 }
69
70 void
71 JvmtiAgentThread::start_function_wrapper(JavaThread *thread, TRAPS) {
72 // It is expected that any Agent threads will be created as
73 // Java Threads. If this is the case, notification of the creation
74 // of the thread is given in JavaThread::thread_main().
75 assert(thread->is_Java_thread(), "debugger thread should be a Java Thread");
76 assert(thread == JavaThread::current(), "sanity check");
77
78 JvmtiAgentThread *dthread = (JvmtiAgentThread *)thread;
79 dthread->call_start_function();
80 }
81
82 void
83 JvmtiAgentThread::call_start_function() {
84 ThreadToNativeFromVM transition(this);
85 _start_fn(_env->jvmti_external(), jni_environment(), (void*)_start_arg);
86 }
87
88
89 //
90 // class GrowableCache - private methods
91 //
92
93 void GrowableCache::recache() {
94 int len = _elements->length();
95
96 FREE_C_HEAP_ARRAY(address, _cache);
97 _cache = NEW_C_HEAP_ARRAY(address,len+1, mtInternal);
98
99 for (int i=0; i<len; i++) {
100 _cache[i] = _elements->at(i)->getCacheValue();
101 //
102 // The cache entry has gone bad. Without a valid frame pointer
103 // value, the entry is useless so we simply delete it in product
104 // mode. The call to remove() will rebuild the cache again
105 // without the bad entry.
106 //
107 if (_cache[i] == NULL) {
108 assert(false, "cannot recache NULL elements");
109 remove(i);
110 return;
111 }
112 }
113 _cache[len] = NULL;
114
115 _listener_fun(_this_obj,_cache);
116 }
117
118 bool GrowableCache::equals(void* v, GrowableElement *e2) {
119 GrowableElement *e1 = (GrowableElement *) v;
120 assert(e1 != NULL, "e1 != NULL");
121 assert(e2 != NULL, "e2 != NULL");
122
123 return e1->equals(e2);
124 }
125
126 //
127 // class GrowableCache - public methods
128 //
129
130 GrowableCache::GrowableCache() {
131 _this_obj = NULL;
132 _listener_fun = NULL;
133 _elements = NULL;
134 _cache = NULL;
135 }
136
137 GrowableCache::~GrowableCache() {
138 clear();
139 delete _elements;
140 FREE_C_HEAP_ARRAY(address, _cache);
141 }
142
143 void GrowableCache::initialize(void *this_obj, void listener_fun(void *, address*) ) {
144 _this_obj = this_obj;
145 _listener_fun = listener_fun;
146 _elements = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<GrowableElement*>(5,true);
147 recache();
148 }
149
150 // number of elements in the collection
151 int GrowableCache::length() {
152 return _elements->length();
153 }
154
155 // get the value of the index element in the collection
156 GrowableElement* GrowableCache::at(int index) {
157 GrowableElement *e = (GrowableElement *) _elements->at(index);
158 assert(e != NULL, "e != NULL");
159 return e;
160 }
161
162 int GrowableCache::find(GrowableElement* e) {
163 return _elements->find(e, GrowableCache::equals);
164 }
165
166 // append a copy of the element to the end of the collection
167 void GrowableCache::append(GrowableElement* e) {
168 GrowableElement *new_e = e->clone();
169 _elements->append(new_e);
170 recache();
171 }
172
173 // insert a copy of the element using lessthan()
174 void GrowableCache::insert(GrowableElement* e) {
175 GrowableElement *new_e = e->clone();
176 _elements->append(new_e);
177
178 int n = length()-2;
179 for (int i=n; i>=0; i--) {
180 GrowableElement *e1 = _elements->at(i);
181 GrowableElement *e2 = _elements->at(i+1);
182 if (e2->lessThan(e1)) {
183 _elements->at_put(i+1, e1);
184 _elements->at_put(i, e2);
185 }
186 }
187
188 recache();
189 }
190
191 // remove the element at index
192 void GrowableCache::remove (int index) {
193 GrowableElement *e = _elements->at(index);
194 assert(e != NULL, "e != NULL");
195 _elements->remove(e);
196 delete e;
197 recache();
198 }
199
200 // clear out all elements, release all heap space and
201 // let our listener know that things have changed.
202 void GrowableCache::clear() {
203 int len = _elements->length();
204 for (int i=0; i<len; i++) {
205 delete _elements->at(i);
206 }
207 _elements->clear();
208 recache();
209 }
210
211 void GrowableCache::oops_do(OopClosure* f) {
212 int len = _elements->length();
213 for (int i=0; i<len; i++) {
214 GrowableElement *e = _elements->at(i);
215 e->oops_do(f);
216 }
217 }
218
219 void GrowableCache::metadata_do(void f(Metadata*)) {
220 int len = _elements->length();
221 for (int i=0; i<len; i++) {
222 GrowableElement *e = _elements->at(i);
223 e->metadata_do(f);
224 }
225 }
226
227 void GrowableCache::gc_epilogue() {
228 int len = _elements->length();
229 for (int i=0; i<len; i++) {
230 _cache[i] = _elements->at(i)->getCacheValue();
231 }
232 }
233
234 //
235 // class JvmtiBreakpoint
236 //
237
238 JvmtiBreakpoint::JvmtiBreakpoint() {
239 _method = NULL;
240 _bci = 0;
241 _class_holder = NULL;
242 }
243
244 JvmtiBreakpoint::JvmtiBreakpoint(Method* m_method, jlocation location) {
245 _method = m_method;
246 _class_holder = _method->method_holder()->klass_holder();
247 #ifdef CHECK_UNHANDLED_OOPS
248 // _class_holder can't be wrapped in a Handle, because JvmtiBreakpoints are
249 // sometimes allocated on the heap.
250 //
251 // The code handling JvmtiBreakpoints allocated on the stack can't be
252 // interrupted by a GC until _class_holder is reachable by the GC via the
253 // oops_do method.
254 Thread::current()->allow_unhandled_oop(&_class_holder);
255 #endif // CHECK_UNHANDLED_OOPS
256 assert(_method != NULL, "_method != NULL");
257 _bci = (int) location;
258 assert(_bci >= 0, "_bci >= 0");
259 }
260
261 void JvmtiBreakpoint::copy(JvmtiBreakpoint& bp) {
262 _method = bp._method;
263 _bci = bp._bci;
264 _class_holder = bp._class_holder;
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 // class loader can be NULL
279 return _method != NULL &&
280 _bci >= 0;
281 }
282
283 address JvmtiBreakpoint::getBcp() const {
284 return _method->bcp_from(_bci);
285 }
286
287 void JvmtiBreakpoint::each_method_version_do(method_action meth_act) {
288 ((Method*)_method->*meth_act)(_bci);
289
290 // add/remove breakpoint to/from versions of the method that are EMCP.
291 Thread *thread = Thread::current();
292 InstanceKlass* ik = _method->method_holder();
293 Symbol* m_name = _method->name();
294 Symbol* m_signature = _method->signature();
295
296 // search previous versions if they exist
297 for (InstanceKlass* pv_node = ik->previous_versions();
298 pv_node != NULL;
299 pv_node = pv_node->previous_versions()) {
300 Array<Method*>* methods = pv_node->methods();
301
302 for (int i = methods->length() - 1; i >= 0; i--) {
303 Method* method = methods->at(i);
304 // Only set breakpoints in running EMCP methods.
305 if (method->is_running_emcp() &&
306 method->name() == m_name &&
307 method->signature() == m_signature) {
308 ResourceMark rm;
309 log_debug(redefine, class, breakpoint)
310 ("%sing breakpoint in %s(%s)", meth_act == &Method::set_breakpoint ? "sett" : "clear",
311 method->name()->as_C_string(), method->signature()->as_C_string());
312 (method->*meth_act)(_bci);
313 break;
314 }
315 }
316 }
317 }
318
319 void JvmtiBreakpoint::set() {
320 each_method_version_do(&Method::set_breakpoint);
321 }
322
323 void JvmtiBreakpoint::clear() {
324 each_method_version_do(&Method::clear_breakpoint);
325 }
326
327 void JvmtiBreakpoint::print_on(outputStream* out) const {
328 #ifndef PRODUCT
329 ResourceMark rm;
330 const char *class_name = (_method == NULL) ? "NULL" : _method->klass_name()->as_C_string();
331 const char *method_name = (_method == NULL) ? "NULL" : _method->name()->as_C_string();
332 out->print("Breakpoint(%s,%s,%d,%p)", class_name, method_name, _bci, getBcp());
333 #endif
334 }
335
336
337 //
338 // class VM_ChangeBreakpoints
339 //
340 // Modify the Breakpoints data structure at a safepoint
341 //
342
343 void VM_ChangeBreakpoints::doit() {
344 switch (_operation) {
345 case SET_BREAKPOINT:
346 _breakpoints->set_at_safepoint(*_bp);
347 break;
348 case CLEAR_BREAKPOINT:
349 _breakpoints->clear_at_safepoint(*_bp);
350 break;
351 default:
352 assert(false, "Unknown operation");
353 }
354 }
355
356 void VM_ChangeBreakpoints::oops_do(OopClosure* f) {
357 // The JvmtiBreakpoints in _breakpoints will be visited via
358 // JvmtiExport::oops_do.
359 if (_bp != NULL) {
360 _bp->oops_do(f);
361 }
362 }
363
364 void VM_ChangeBreakpoints::metadata_do(void f(Metadata*)) {
365 // Walk metadata in breakpoints to keep from being deallocated with RedefineClasses
366 if (_bp != NULL) {
367 _bp->metadata_do(f);
368 }
369 }
370
371 //
372 // class JvmtiBreakpoints
373 //
374 // a JVMTI internal collection of JvmtiBreakpoint
375 //
376
377 JvmtiBreakpoints::JvmtiBreakpoints(void listener_fun(void *,address *)) {
378 _bps.initialize(this,listener_fun);
379 }
380
381 JvmtiBreakpoints:: ~JvmtiBreakpoints() {}
382
383 void JvmtiBreakpoints::oops_do(OopClosure* f) {
384 _bps.oops_do(f);
385 }
386
387 void JvmtiBreakpoints::metadata_do(void f(Metadata*)) {
388 _bps.metadata_do(f);
389 }
390
391 void JvmtiBreakpoints::gc_epilogue() {
392 _bps.gc_epilogue();
393 }
394
395 void JvmtiBreakpoints::print() {
396 #ifndef PRODUCT
397 LogTarget(Trace, jvmti) log;
398 LogStream log_stream(log);
399
400 int n = _bps.length();
401 for (int i=0; i<n; i++) {
402 JvmtiBreakpoint& bp = _bps.at(i);
403 log_stream.print("%d: ", i);
404 bp.print_on(&log_stream);
405 log_stream.cr();
406 }
407 #endif
408 }
409
410
411 void JvmtiBreakpoints::set_at_safepoint(JvmtiBreakpoint& bp) {
412 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
413
414 int i = _bps.find(bp);
415 if (i == -1) {
416 _bps.append(bp);
417 bp.set();
418 }
419 }
420
421 void JvmtiBreakpoints::clear_at_safepoint(JvmtiBreakpoint& bp) {
422 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
423
424 int i = _bps.find(bp);
425 if (i != -1) {
426 _bps.remove(i);
427 bp.clear();
428 }
429 }
430
431 int JvmtiBreakpoints::length() { return _bps.length(); }
432
433 int JvmtiBreakpoints::set(JvmtiBreakpoint& bp) {
434 if ( _bps.find(bp) != -1) {
435 return JVMTI_ERROR_DUPLICATE;
436 }
437 VM_ChangeBreakpoints set_breakpoint(VM_ChangeBreakpoints::SET_BREAKPOINT, &bp);
438 VMThread::execute(&set_breakpoint);
439 return JVMTI_ERROR_NONE;
440 }
441
442 int JvmtiBreakpoints::clear(JvmtiBreakpoint& bp) {
443 if ( _bps.find(bp) == -1) {
444 return JVMTI_ERROR_NOT_FOUND;
445 }
446
447 VM_ChangeBreakpoints clear_breakpoint(VM_ChangeBreakpoints::CLEAR_BREAKPOINT, &bp);
448 VMThread::execute(&clear_breakpoint);
449 return JVMTI_ERROR_NONE;
450 }
451
452 void JvmtiBreakpoints::clearall_in_class_at_safepoint(Klass* klass) {
453 bool changed = true;
454 // We are going to run thru the list of bkpts
455 // and delete some. This deletion probably alters
456 // the list in some implementation defined way such
457 // that when we delete entry i, the next entry might
458 // no longer be at i+1. To be safe, each time we delete
459 // an entry, we'll just start again from the beginning.
460 // We'll stop when we make a pass thru the whole list without
461 // deleting anything.
462 while (changed) {
463 int len = _bps.length();
464 changed = false;
465 for (int i = 0; i < len; i++) {
466 JvmtiBreakpoint& bp = _bps.at(i);
467 if (bp.method()->method_holder() == klass) {
468 bp.clear();
469 _bps.remove(i);
470 // This changed 'i' so we have to start over.
471 changed = true;
472 break;
473 }
474 }
475 }
476 }
477
478 //
479 // class JvmtiCurrentBreakpoints
480 //
481
482 JvmtiBreakpoints *JvmtiCurrentBreakpoints::_jvmti_breakpoints = NULL;
483 address * JvmtiCurrentBreakpoints::_breakpoint_list = NULL;
484
485
486 JvmtiBreakpoints& JvmtiCurrentBreakpoints::get_jvmti_breakpoints() {
487 if (_jvmti_breakpoints != NULL) return (*_jvmti_breakpoints);
488 _jvmti_breakpoints = new JvmtiBreakpoints(listener_fun);
489 assert(_jvmti_breakpoints != NULL, "_jvmti_breakpoints != NULL");
490 return (*_jvmti_breakpoints);
491 }
492
493 void JvmtiCurrentBreakpoints::listener_fun(void *this_obj, address *cache) {
494 JvmtiBreakpoints *this_jvmti = (JvmtiBreakpoints *) this_obj;
495 assert(this_jvmti != NULL, "this_jvmti != NULL");
496
497 debug_only(int n = this_jvmti->length(););
498 assert(cache[n] == NULL, "cache must be NULL terminated");
499
500 set_breakpoint_list(cache);
501 }
502
503
504 void JvmtiCurrentBreakpoints::oops_do(OopClosure* f) {
505 if (_jvmti_breakpoints != NULL) {
506 _jvmti_breakpoints->oops_do(f);
507 }
508 }
509
510 void JvmtiCurrentBreakpoints::metadata_do(void f(Metadata*)) {
511 if (_jvmti_breakpoints != NULL) {
512 _jvmti_breakpoints->metadata_do(f);
513 }
514 }
515
516 void JvmtiCurrentBreakpoints::gc_epilogue() {
517 if (_jvmti_breakpoints != NULL) {
518 _jvmti_breakpoints->gc_epilogue();
519 }
520 }
521
522 ///////////////////////////////////////////////////////////////
523 //
524 // class VM_GetOrSetLocal
525 //
526
527 // Constructor for non-object getter
528 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, jint depth, jint index, BasicType type)
529 : _thread(thread)
530 , _calling_thread(NULL)
531 , _depth(depth)
532 , _index(index)
533 , _type(type)
534 , _set(false)
535 , _jvf(NULL)
536 , _result(JVMTI_ERROR_NONE)
537 {
538 }
539
540 // Constructor for object or non-object setter
541 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, jint depth, jint index, BasicType type, jvalue value)
542 : _thread(thread)
543 , _calling_thread(NULL)
544 , _depth(depth)
545 , _index(index)
546 , _type(type)
547 , _value(value)
548 , _set(true)
549 , _jvf(NULL)
550 , _result(JVMTI_ERROR_NONE)
551 {
552 }
553
554 // Constructor for object getter
555 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, JavaThread* calling_thread, jint depth, int index)
556 : _thread(thread)
557 , _calling_thread(calling_thread)
558 , _depth(depth)
559 , _index(index)
560 , _type(T_OBJECT)
561 , _set(false)
562 , _jvf(NULL)
563 , _result(JVMTI_ERROR_NONE)
564 {
565 }
566
567 vframe *VM_GetOrSetLocal::get_vframe() {
568 if (!_thread->has_last_Java_frame()) {
569 return NULL;
570 }
571 RegisterMap reg_map(_thread);
572 vframe *vf = _thread->last_java_vframe(®_map);
573 int d = 0;
574 while ((vf != NULL) && (d < _depth)) {
575 vf = vf->java_sender();
576 d++;
577 }
578 return vf;
579 }
580
581 javaVFrame *VM_GetOrSetLocal::get_java_vframe() {
582 vframe* vf = get_vframe();
583 if (vf == NULL) {
584 _result = JVMTI_ERROR_NO_MORE_FRAMES;
585 return NULL;
586 }
587 javaVFrame *jvf = (javaVFrame*)vf;
588
589 if (!vf->is_java_frame()) {
590 _result = JVMTI_ERROR_OPAQUE_FRAME;
591 return NULL;
592 }
593 return jvf;
594 }
595
596 // Check that the klass is assignable to a type with the given signature.
597 // Another solution could be to use the function Klass::is_subtype_of(type).
598 // But the type class can be forced to load/initialize eagerly in such a case.
599 // This may cause unexpected consequences like CFLH or class-init JVMTI events.
600 // It is better to avoid such a behavior.
601 bool VM_GetOrSetLocal::is_assignable(const char* ty_sign, Klass* klass, Thread* thread) {
602 assert(ty_sign != NULL, "type signature must not be NULL");
603 assert(thread != NULL, "thread must not be NULL");
604 assert(klass != NULL, "klass must not be NULL");
605
606 int len = (int) strlen(ty_sign);
607 if (ty_sign[0] == 'L' && ty_sign[len-1] == ';') { // Need pure class/interface name
608 ty_sign++;
609 len -= 2;
610 }
611 TempNewSymbol ty_sym = SymbolTable::new_symbol(ty_sign, len, thread);
612 if (klass->name() == ty_sym) {
613 return true;
614 }
615 // Compare primary supers
616 int super_depth = klass->super_depth();
617 int idx;
618 for (idx = 0; idx < super_depth; idx++) {
619 if (klass->primary_super_of_depth(idx)->name() == ty_sym) {
620 return true;
621 }
622 }
623 // Compare secondary supers
624 Array<Klass*>* sec_supers = klass->secondary_supers();
625 for (idx = 0; idx < sec_supers->length(); idx++) {
626 if (((Klass*) sec_supers->at(idx))->name() == ty_sym) {
627 return true;
628 }
629 }
630 return false;
631 }
632
633 // Checks error conditions:
634 // JVMTI_ERROR_INVALID_SLOT
635 // JVMTI_ERROR_TYPE_MISMATCH
636 // Returns: 'true' - everything is Ok, 'false' - error code
637
638 bool VM_GetOrSetLocal::check_slot_type(javaVFrame* jvf) {
639 Method* method_oop = jvf->method();
640 if (!method_oop->has_localvariable_table()) {
641 // Just to check index boundaries
642 jint extra_slot = (_type == T_LONG || _type == T_DOUBLE) ? 1 : 0;
643 if (_index < 0 || _index + extra_slot >= method_oop->max_locals()) {
644 _result = JVMTI_ERROR_INVALID_SLOT;
645 return false;
646 }
647 return true;
648 }
649
650 jint num_entries = method_oop->localvariable_table_length();
651 if (num_entries == 0) {
652 _result = JVMTI_ERROR_INVALID_SLOT;
653 return false; // There are no slots
654 }
655 int signature_idx = -1;
656 int vf_bci = jvf->bci();
657 LocalVariableTableElement* table = method_oop->localvariable_table_start();
658 for (int i = 0; i < num_entries; i++) {
659 int start_bci = table[i].start_bci;
660 int end_bci = start_bci + table[i].length;
661
662 // Here we assume that locations of LVT entries
663 // with the same slot number cannot be overlapped
664 if (_index == (jint) table[i].slot && start_bci <= vf_bci && vf_bci <= end_bci) {
665 signature_idx = (int) table[i].descriptor_cp_index;
666 break;
667 }
668 }
669 if (signature_idx == -1) {
670 _result = JVMTI_ERROR_INVALID_SLOT;
671 return false; // Incorrect slot index
672 }
673 Symbol* sign_sym = method_oop->constants()->symbol_at(signature_idx);
674 const char* signature = (const char *) sign_sym->as_utf8();
675 BasicType slot_type = char2type(signature[0]);
676
677 switch (slot_type) {
678 case T_BYTE:
679 case T_SHORT:
680 case T_CHAR:
681 case T_BOOLEAN:
682 slot_type = T_INT;
683 break;
684 case T_ARRAY:
685 slot_type = T_OBJECT;
686 break;
687 default:
688 break;
689 };
690 if (_type != slot_type) {
691 _result = JVMTI_ERROR_TYPE_MISMATCH;
692 return false;
693 }
694
695 jobject jobj = _value.l;
696 if (_set && slot_type == T_OBJECT && jobj != NULL) { // NULL reference is allowed
697 // Check that the jobject class matches the return type signature.
698 JavaThread* cur_thread = JavaThread::current();
699 HandleMark hm(cur_thread);
700
701 Handle obj(cur_thread, JNIHandles::resolve_external_guard(jobj));
702 NULL_CHECK(obj, (_result = JVMTI_ERROR_INVALID_OBJECT, false));
703 Klass* ob_k = obj->klass();
704 NULL_CHECK(ob_k, (_result = JVMTI_ERROR_INVALID_OBJECT, false));
705
706 if (!is_assignable(signature, ob_k, cur_thread)) {
707 _result = JVMTI_ERROR_TYPE_MISMATCH;
708 return false;
709 }
710 }
711 return true;
712 }
713
714 static bool can_be_deoptimized(vframe* vf) {
715 return (vf->is_compiled_frame() && vf->fr().can_be_deoptimized());
716 }
717
718 bool VM_GetOrSetLocal::doit_prologue() {
719 _jvf = get_java_vframe();
720 NULL_CHECK(_jvf, false);
721
722 if (_jvf->method()->is_native()) {
723 if (getting_receiver() && !_jvf->method()->is_static()) {
724 return true;
725 } else {
726 _result = JVMTI_ERROR_OPAQUE_FRAME;
727 return false;
728 }
729 }
730
731 if (!check_slot_type(_jvf)) {
732 return false;
733 }
734 return true;
735 }
736
737 void VM_GetOrSetLocal::doit() {
738 InterpreterOopMap oop_mask;
739 _jvf->method()->mask_for(_jvf->bci(), &oop_mask);
740 if (oop_mask.is_dead(_index)) {
741 // The local can be invalid and uninitialized in the scope of current bci
742 _result = JVMTI_ERROR_INVALID_SLOT;
743 return;
744 }
745 if (_set) {
746 // Force deoptimization of frame if compiled because it's
747 // possible the compiler emitted some locals as constant values,
748 // meaning they are not mutable.
749 if (can_be_deoptimized(_jvf)) {
750
751 // Schedule deoptimization so that eventually the local
752 // update will be written to an interpreter frame.
753 Deoptimization::deoptimize_frame(_jvf->thread(), _jvf->fr().id());
754
755 // Now store a new value for the local which will be applied
756 // once deoptimization occurs. Note however that while this
757 // write is deferred until deoptimization actually happens
758 // can vframe created after this point will have its locals
759 // reflecting this update so as far as anyone can see the
760 // write has already taken place.
761
762 // If we are updating an oop then get the oop from the handle
763 // since the handle will be long gone by the time the deopt
764 // happens. The oop stored in the deferred local will be
765 // gc'd on its own.
766 if (_type == T_OBJECT) {
767 _value.l = (jobject) (JNIHandles::resolve_external_guard(_value.l));
768 }
769 // Re-read the vframe so we can see that it is deoptimized
770 // [ Only need because of assert in update_local() ]
771 _jvf = get_java_vframe();
772 ((compiledVFrame*)_jvf)->update_local(_type, _index, _value);
773 return;
774 }
775 StackValueCollection *locals = _jvf->locals();
776 HandleMark hm;
777
778 switch (_type) {
779 case T_INT: locals->set_int_at (_index, _value.i); break;
780 case T_LONG: locals->set_long_at (_index, _value.j); break;
781 case T_FLOAT: locals->set_float_at (_index, _value.f); break;
782 case T_DOUBLE: locals->set_double_at(_index, _value.d); break;
783 case T_OBJECT: {
784 Handle ob_h(Thread::current(), JNIHandles::resolve_external_guard(_value.l));
785 locals->set_obj_at (_index, ob_h);
786 break;
787 }
788 default: ShouldNotReachHere();
789 }
790 _jvf->set_locals(locals);
791 } else {
792 if (_jvf->method()->is_native() && _jvf->is_compiled_frame()) {
793 assert(getting_receiver(), "Can only get here when getting receiver");
794 oop receiver = _jvf->fr().get_native_receiver();
795 _value.l = JNIHandles::make_local(_calling_thread, receiver);
796 } else {
797 StackValueCollection *locals = _jvf->locals();
798
799 if (locals->at(_index)->type() == T_CONFLICT) {
800 memset(&_value, 0, sizeof(_value));
801 _value.l = NULL;
802 return;
803 }
804
805 switch (_type) {
806 case T_INT: _value.i = locals->int_at (_index); break;
807 case T_LONG: _value.j = locals->long_at (_index); break;
808 case T_FLOAT: _value.f = locals->float_at (_index); break;
809 case T_DOUBLE: _value.d = locals->double_at(_index); break;
810 case T_OBJECT: {
811 // Wrap the oop to be returned in a local JNI handle since
812 // oops_do() no longer applies after doit() is finished.
813 oop obj = locals->obj_at(_index)();
814 _value.l = JNIHandles::make_local(_calling_thread, obj);
815 break;
816 }
817 default: ShouldNotReachHere();
818 }
819 }
820 }
821 }
822
823
824 bool VM_GetOrSetLocal::allow_nested_vm_operations() const {
825 return true; // May need to deoptimize
826 }
827
828
829 VM_GetReceiver::VM_GetReceiver(
830 JavaThread* thread, JavaThread* caller_thread, jint depth)
831 : VM_GetOrSetLocal(thread, caller_thread, depth, 0) {}
832
833 /////////////////////////////////////////////////////////////////////////////////////////
834
835 //
836 // class JvmtiSuspendControl - see comments in jvmtiImpl.hpp
837 //
838
839 bool JvmtiSuspendControl::suspend(JavaThread *java_thread) {
840 // external suspend should have caught suspending a thread twice
841
842 // Immediate suspension required for JPDA back-end so JVMTI agent threads do
843 // not deadlock due to later suspension on transitions while holding
844 // raw monitors. Passing true causes the immediate suspension.
845 // java_suspend() will catch threads in the process of exiting
846 // and will ignore them.
847 java_thread->java_suspend();
848
849 // It would be nice to have the following assertion in all the time,
850 // but it is possible for a racing resume request to have resumed
851 // this thread right after we suspended it. Temporarily enable this
852 // assertion if you are chasing a different kind of bug.
853 //
854 // assert(java_lang_Thread::thread(java_thread->threadObj()) == NULL ||
855 // java_thread->is_being_ext_suspended(), "thread is not suspended");
856
857 if (java_lang_Thread::thread(java_thread->threadObj()) == NULL) {
858 // check again because we can get delayed in java_suspend():
859 // the thread is in process of exiting.
860 return false;
861 }
862
863 return true;
864 }
865
866 bool JvmtiSuspendControl::resume(JavaThread *java_thread) {
867 // external suspend should have caught resuming a thread twice
868 assert(java_thread->is_being_ext_suspended(), "thread should be suspended");
869
870 // resume thread
871 {
872 // must always grab Threads_lock, see JVM_SuspendThread
873 MutexLocker ml(Threads_lock);
874 java_thread->java_resume();
875 }
876
877 return true;
878 }
879
880
881 void JvmtiSuspendControl::print() {
882 #ifndef PRODUCT
883 LogStreamHandle(Trace, jvmti) log_stream;
884 log_stream.print("Suspended Threads: [");
885 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *thread = jtiwh.next(); ) {
886 #ifdef JVMTI_TRACE
887 const char *name = JvmtiTrace::safe_get_thread_name(thread);
888 #else
889 const char *name = "";
890 #endif /*JVMTI_TRACE */
891 log_stream.print("%s(%c ", name, thread->is_being_ext_suspended() ? 'S' : '_');
892 if (!thread->has_last_Java_frame()) {
893 log_stream.print("no stack");
894 }
895 log_stream.print(") ");
896 }
897 log_stream.print_cr("]");
898 #endif
899 }
900
901 JvmtiDeferredEvent JvmtiDeferredEvent::compiled_method_load_event(
902 nmethod* nm) {
903 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_COMPILED_METHOD_LOAD);
904 event._event_data.compiled_method_load = nm;
905 // Keep the nmethod alive until the ServiceThread can process
906 // this deferred event.
907 nmethodLocker::lock_nmethod(nm);
908 return event;
909 }
910
911 JvmtiDeferredEvent JvmtiDeferredEvent::compiled_method_unload_event(
912 nmethod* nm, jmethodID id, const void* code) {
913 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_COMPILED_METHOD_UNLOAD);
914 event._event_data.compiled_method_unload.nm = nm;
915 event._event_data.compiled_method_unload.method_id = id;
916 event._event_data.compiled_method_unload.code_begin = code;
917 // Keep the nmethod alive until the ServiceThread can process
918 // this deferred event. This will keep the memory for the
919 // generated code from being reused too early. We pass
920 // zombie_ok == true here so that our nmethod that was just
921 // made into a zombie can be locked.
922 nmethodLocker::lock_nmethod(nm, true /* zombie_ok */);
923 return event;
924 }
925
926 JvmtiDeferredEvent JvmtiDeferredEvent::dynamic_code_generated_event(
927 const char* name, const void* code_begin, const void* code_end) {
928 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_DYNAMIC_CODE_GENERATED);
929 // Need to make a copy of the name since we don't know how long
930 // the event poster will keep it around after we enqueue the
931 // deferred event and return. strdup() failure is handled in
932 // the post() routine below.
933 event._event_data.dynamic_code_generated.name = os::strdup(name);
934 event._event_data.dynamic_code_generated.code_begin = code_begin;
935 event._event_data.dynamic_code_generated.code_end = code_end;
936 return event;
937 }
938
939 void JvmtiDeferredEvent::post() {
940 assert(ServiceThread::is_service_thread(Thread::current()),
941 "Service thread must post enqueued events");
942 switch(_type) {
943 case TYPE_COMPILED_METHOD_LOAD: {
944 nmethod* nm = _event_data.compiled_method_load;
945 JvmtiExport::post_compiled_method_load(nm);
946 // done with the deferred event so unlock the nmethod
947 nmethodLocker::unlock_nmethod(nm);
948 break;
949 }
950 case TYPE_COMPILED_METHOD_UNLOAD: {
951 nmethod* nm = _event_data.compiled_method_unload.nm;
952 JvmtiExport::post_compiled_method_unload(
953 _event_data.compiled_method_unload.method_id,
954 _event_data.compiled_method_unload.code_begin);
955 // done with the deferred event so unlock the nmethod
956 nmethodLocker::unlock_nmethod(nm);
957 break;
958 }
959 case TYPE_DYNAMIC_CODE_GENERATED: {
960 JvmtiExport::post_dynamic_code_generated_internal(
961 // if strdup failed give the event a default name
962 (_event_data.dynamic_code_generated.name == NULL)
963 ? "unknown_code" : _event_data.dynamic_code_generated.name,
964 _event_data.dynamic_code_generated.code_begin,
965 _event_data.dynamic_code_generated.code_end);
966 if (_event_data.dynamic_code_generated.name != NULL) {
967 // release our copy
968 os::free((void *)_event_data.dynamic_code_generated.name);
969 }
970 break;
971 }
972 default:
973 ShouldNotReachHere();
974 }
975 }
976
977 JvmtiDeferredEventQueue::QueueNode* JvmtiDeferredEventQueue::_queue_tail = NULL;
978 JvmtiDeferredEventQueue::QueueNode* JvmtiDeferredEventQueue::_queue_head = NULL;
979
980 bool JvmtiDeferredEventQueue::has_events() {
981 assert(Service_lock->owned_by_self(), "Must own Service_lock");
982 return _queue_head != NULL;
983 }
984
985 void JvmtiDeferredEventQueue::enqueue(const JvmtiDeferredEvent& event) {
986 assert(Service_lock->owned_by_self(), "Must own Service_lock");
987
988 // Events get added to the end of the queue (and are pulled off the front).
989 QueueNode* node = new QueueNode(event);
990 if (_queue_tail == NULL) {
991 _queue_tail = _queue_head = node;
992 } else {
993 assert(_queue_tail->next() == NULL, "Must be the last element in the list");
994 _queue_tail->set_next(node);
995 _queue_tail = node;
996 }
997
998 Service_lock->notify_all();
999 assert((_queue_head == NULL) == (_queue_tail == NULL),
1000 "Inconsistent queue markers");
1001 }
1002
1003 JvmtiDeferredEvent JvmtiDeferredEventQueue::dequeue() {
1004 assert(Service_lock->owned_by_self(), "Must own Service_lock");
1005
1006 assert(_queue_head != NULL, "Nothing to dequeue");
1007
1008 if (_queue_head == NULL) {
1009 // Just in case this happens in product; it shouldn't but let's not crash
1010 return JvmtiDeferredEvent();
1011 }
1012
1013 QueueNode* node = _queue_head;
1014 _queue_head = _queue_head->next();
1015 if (_queue_head == NULL) {
1016 _queue_tail = NULL;
1017 }
1018
1019 assert((_queue_head == NULL) == (_queue_tail == NULL),
1020 "Inconsistent queue markers");
1021
1022 JvmtiDeferredEvent event = node->event();
1023 delete node;
1024 return event;
1025 }