1 /*
2 * Copyright (c) 2003, 2017, 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/resourceArea.hpp"
33 #include "oops/instanceKlass.hpp"
34 #include "oops/oop.inline.hpp"
35 #include "prims/jvmtiAgentThread.hpp"
36 #include "prims/jvmtiEventController.inline.hpp"
37 #include "prims/jvmtiImpl.hpp"
38 #include "prims/jvmtiRedefineClasses.hpp"
39 #include "runtime/atomic.hpp"
40 #include "runtime/deoptimization.hpp"
41 #include "runtime/handles.hpp"
42 #include "runtime/handles.inline.hpp"
43 #include "runtime/interfaceSupport.hpp"
44 #include "runtime/javaCalls.hpp"
45 #include "runtime/os.hpp"
46 #include "runtime/serviceThread.hpp"
47 #include "runtime/signature.hpp"
48 #include "runtime/thread.inline.hpp"
49 #include "runtime/threadSMR.hpp"
50 #include "runtime/vframe.hpp"
51 #include "runtime/vframe_hp.hpp"
52 #include "runtime/vm_operations.hpp"
53 #include "utilities/exceptions.hpp"
54
55 //
56 // class JvmtiAgentThread
57 //
58 // JavaThread used to wrap a thread started by an agent
59 // using the JVMTI method RunAgentThread.
60 //
61
62 JvmtiAgentThread::JvmtiAgentThread(JvmtiEnv* env, jvmtiStartFunction start_fn, const void *start_arg)
63 : JavaThread(start_function_wrapper) {
64 _env = env;
65 _start_fn = start_fn;
66 _start_arg = start_arg;
67 }
68
69 void
70 JvmtiAgentThread::start_function_wrapper(JavaThread *thread, TRAPS) {
71 // It is expected that any Agent threads will be created as
72 // Java Threads. If this is the case, notification of the creation
73 // of the thread is given in JavaThread::thread_main().
74 assert(thread->is_Java_thread(), "debugger thread should be a Java Thread");
75 assert(thread == JavaThread::current(), "sanity check");
76
77 JvmtiAgentThread *dthread = (JvmtiAgentThread *)thread;
78 dthread->call_start_function();
79 }
80
81 void
82 JvmtiAgentThread::call_start_function() {
83 ThreadToNativeFromVM transition(this);
84 _start_fn(_env->jvmti_external(), jni_environment(), (void*)_start_arg);
85 }
86
87
88 //
89 // class GrowableCache - private methods
90 //
91
92 void GrowableCache::recache() {
93 int len = _elements->length();
94
95 FREE_C_HEAP_ARRAY(address, _cache);
96 _cache = NEW_C_HEAP_ARRAY(address,len+1, mtInternal);
97
98 for (int i=0; i<len; i++) {
99 _cache[i] = _elements->at(i)->getCacheValue();
100 //
101 // The cache entry has gone bad. Without a valid frame pointer
102 // value, the entry is useless so we simply delete it in product
103 // mode. The call to remove() will rebuild the cache again
104 // without the bad entry.
105 //
106 if (_cache[i] == NULL) {
107 assert(false, "cannot recache NULL elements");
108 remove(i);
109 return;
110 }
111 }
112 _cache[len] = NULL;
113
114 _listener_fun(_this_obj,_cache);
115 }
116
117 bool GrowableCache::equals(void* v, GrowableElement *e2) {
118 GrowableElement *e1 = (GrowableElement *) v;
119 assert(e1 != NULL, "e1 != NULL");
120 assert(e2 != NULL, "e2 != NULL");
121
122 return e1->equals(e2);
123 }
124
125 //
126 // class GrowableCache - public methods
127 //
128
129 GrowableCache::GrowableCache() {
130 _this_obj = NULL;
131 _listener_fun = NULL;
132 _elements = NULL;
133 _cache = NULL;
134 }
135
136 GrowableCache::~GrowableCache() {
137 clear();
138 delete _elements;
139 FREE_C_HEAP_ARRAY(address, _cache);
140 }
141
142 void GrowableCache::initialize(void *this_obj, void listener_fun(void *, address*) ) {
143 _this_obj = this_obj;
144 _listener_fun = listener_fun;
145 _elements = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<GrowableElement*>(5,true);
146 recache();
147 }
148
149 // number of elements in the collection
150 int GrowableCache::length() {
151 return _elements->length();
152 }
153
154 // get the value of the index element in the collection
155 GrowableElement* GrowableCache::at(int index) {
156 GrowableElement *e = (GrowableElement *) _elements->at(index);
157 assert(e != NULL, "e != NULL");
158 return e;
159 }
160
161 int GrowableCache::find(GrowableElement* e) {
162 return _elements->find(e, GrowableCache::equals);
163 }
164
165 // append a copy of the element to the end of the collection
166 void GrowableCache::append(GrowableElement* e) {
167 GrowableElement *new_e = e->clone();
168 _elements->append(new_e);
169 recache();
170 }
171
172 // insert a copy of the element using lessthan()
173 void GrowableCache::insert(GrowableElement* e) {
174 GrowableElement *new_e = e->clone();
175 _elements->append(new_e);
176
177 int n = length()-2;
178 for (int i=n; i>=0; i--) {
179 GrowableElement *e1 = _elements->at(i);
180 GrowableElement *e2 = _elements->at(i+1);
181 if (e2->lessThan(e1)) {
182 _elements->at_put(i+1, e1);
183 _elements->at_put(i, e2);
184 }
185 }
186
187 recache();
188 }
189
190 // remove the element at index
191 void GrowableCache::remove (int index) {
192 GrowableElement *e = _elements->at(index);
193 assert(e != NULL, "e != NULL");
194 _elements->remove(e);
195 delete e;
196 recache();
197 }
198
199 // clear out all elements, release all heap space and
200 // let our listener know that things have changed.
201 void GrowableCache::clear() {
202 int len = _elements->length();
203 for (int i=0; i<len; i++) {
204 delete _elements->at(i);
205 }
206 _elements->clear();
207 recache();
208 }
209
210 void GrowableCache::oops_do(OopClosure* f) {
211 int len = _elements->length();
212 for (int i=0; i<len; i++) {
213 GrowableElement *e = _elements->at(i);
214 e->oops_do(f);
215 }
216 }
217
218 void GrowableCache::metadata_do(void f(Metadata*)) {
219 int len = _elements->length();
220 for (int i=0; i<len; i++) {
221 GrowableElement *e = _elements->at(i);
222 e->metadata_do(f);
223 }
224 }
225
226 void GrowableCache::gc_epilogue() {
227 int len = _elements->length();
228 for (int i=0; i<len; i++) {
229 _cache[i] = _elements->at(i)->getCacheValue();
230 }
231 }
232
233 //
234 // class JvmtiBreakpoint
235 //
236
237 JvmtiBreakpoint::JvmtiBreakpoint() {
238 _method = NULL;
239 _bci = 0;
240 _class_holder = NULL;
241 }
242
243 JvmtiBreakpoint::JvmtiBreakpoint(Method* m_method, jlocation location) {
244 _method = m_method;
245 _class_holder = _method->method_holder()->klass_holder();
246 #ifdef CHECK_UNHANDLED_OOPS
247 // _class_holder can't be wrapped in a Handle, because JvmtiBreakpoints are
248 // sometimes allocated on the heap.
249 //
250 // The code handling JvmtiBreakpoints allocated on the stack can't be
251 // interrupted by a GC until _class_holder is reachable by the GC via the
252 // oops_do method.
253 Thread::current()->allow_unhandled_oop(&_class_holder);
254 #endif // CHECK_UNHANDLED_OOPS
255 assert(_method != NULL, "_method != NULL");
256 _bci = (int) location;
257 assert(_bci >= 0, "_bci >= 0");
258 }
259
260 void JvmtiBreakpoint::copy(JvmtiBreakpoint& bp) {
261 _method = bp._method;
262 _bci = bp._bci;
263 _class_holder = bp._class_holder;
264 }
265
266 bool JvmtiBreakpoint::lessThan(JvmtiBreakpoint& bp) {
267 Unimplemented();
268 return false;
269 }
270
271 bool JvmtiBreakpoint::equals(JvmtiBreakpoint& bp) {
272 return _method == bp._method
273 && _bci == bp._bci;
274 }
275
276 bool JvmtiBreakpoint::is_valid() {
277 // class loader can be NULL
278 return _method != NULL &&
279 _bci >= 0;
280 }
281
282 address JvmtiBreakpoint::getBcp() const {
283 return _method->bcp_from(_bci);
284 }
285
286 void JvmtiBreakpoint::each_method_version_do(method_action meth_act) {
287 ((Method*)_method->*meth_act)(_bci);
288
289 // add/remove breakpoint to/from versions of the method that are EMCP.
290 Thread *thread = Thread::current();
291 InstanceKlass* ik = _method->method_holder();
292 Symbol* m_name = _method->name();
293 Symbol* m_signature = _method->signature();
294
295 // search previous versions if they exist
296 for (InstanceKlass* pv_node = ik->previous_versions();
297 pv_node != NULL;
298 pv_node = pv_node->previous_versions()) {
299 Array<Method*>* methods = pv_node->methods();
300
301 for (int i = methods->length() - 1; i >= 0; i--) {
302 Method* method = methods->at(i);
303 // Only set breakpoints in running EMCP methods.
304 if (method->is_running_emcp() &&
305 method->name() == m_name &&
306 method->signature() == m_signature) {
307 ResourceMark rm;
308 log_debug(redefine, class, breakpoint)
309 ("%sing breakpoint in %s(%s)", meth_act == &Method::set_breakpoint ? "sett" : "clear",
310 method->name()->as_C_string(), method->signature()->as_C_string());
311 (method->*meth_act)(_bci);
312 break;
313 }
314 }
315 }
316 }
317
318 void JvmtiBreakpoint::set() {
319 each_method_version_do(&Method::set_breakpoint);
320 }
321
322 void JvmtiBreakpoint::clear() {
323 each_method_version_do(&Method::clear_breakpoint);
324 }
325
326 void JvmtiBreakpoint::print_on(outputStream* out) const {
327 #ifndef PRODUCT
328 ResourceMark rm;
329 const char *class_name = (_method == NULL) ? "NULL" : _method->klass_name()->as_C_string();
330 const char *method_name = (_method == NULL) ? "NULL" : _method->name()->as_C_string();
331 out->print("Breakpoint(%s,%s,%d,%p)", class_name, method_name, _bci, getBcp());
332 #endif
333 }
334
335
336 //
337 // class VM_ChangeBreakpoints
338 //
339 // Modify the Breakpoints data structure at a safepoint
340 //
341
342 void VM_ChangeBreakpoints::doit() {
343 switch (_operation) {
344 case SET_BREAKPOINT:
345 _breakpoints->set_at_safepoint(*_bp);
346 break;
347 case CLEAR_BREAKPOINT:
348 _breakpoints->clear_at_safepoint(*_bp);
349 break;
350 default:
351 assert(false, "Unknown operation");
352 }
353 }
354
355 void VM_ChangeBreakpoints::oops_do(OopClosure* f) {
356 // The JvmtiBreakpoints in _breakpoints will be visited via
357 // JvmtiExport::oops_do.
358 if (_bp != NULL) {
359 _bp->oops_do(f);
360 }
361 }
362
363 void VM_ChangeBreakpoints::metadata_do(void f(Metadata*)) {
364 // Walk metadata in breakpoints to keep from being deallocated with RedefineClasses
365 if (_bp != NULL) {
366 _bp->metadata_do(f);
367 }
368 }
369
370 //
371 // class JvmtiBreakpoints
372 //
373 // a JVMTI internal collection of JvmtiBreakpoint
374 //
375
376 JvmtiBreakpoints::JvmtiBreakpoints(void listener_fun(void *,address *)) {
377 _bps.initialize(this,listener_fun);
378 }
379
380 JvmtiBreakpoints:: ~JvmtiBreakpoints() {}
381
382 void JvmtiBreakpoints::oops_do(OopClosure* f) {
383 _bps.oops_do(f);
384 }
385
386 void JvmtiBreakpoints::metadata_do(void f(Metadata*)) {
387 _bps.metadata_do(f);
388 }
389
390 void JvmtiBreakpoints::gc_epilogue() {
391 _bps.gc_epilogue();
392 }
393
394 void JvmtiBreakpoints::print() {
395 #ifndef PRODUCT
396 LogTarget(Trace, jvmti) log;
397 LogStream log_stream(log);
398
399 int n = _bps.length();
400 for (int i=0; i<n; i++) {
401 JvmtiBreakpoint& bp = _bps.at(i);
402 log_stream.print("%d: ", i);
403 bp.print_on(&log_stream);
404 log_stream.cr();
405 }
406 #endif
407 }
408
409
410 void JvmtiBreakpoints::set_at_safepoint(JvmtiBreakpoint& bp) {
411 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
412
413 int i = _bps.find(bp);
414 if (i == -1) {
415 _bps.append(bp);
416 bp.set();
417 }
418 }
419
420 void JvmtiBreakpoints::clear_at_safepoint(JvmtiBreakpoint& bp) {
421 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
422
423 int i = _bps.find(bp);
424 if (i != -1) {
425 _bps.remove(i);
426 bp.clear();
427 }
428 }
429
430 int JvmtiBreakpoints::length() { return _bps.length(); }
431
432 int JvmtiBreakpoints::set(JvmtiBreakpoint& bp) {
433 if ( _bps.find(bp) != -1) {
434 return JVMTI_ERROR_DUPLICATE;
435 }
436 VM_ChangeBreakpoints set_breakpoint(VM_ChangeBreakpoints::SET_BREAKPOINT, &bp);
437 VMThread::execute(&set_breakpoint);
438 return JVMTI_ERROR_NONE;
439 }
440
441 int JvmtiBreakpoints::clear(JvmtiBreakpoint& bp) {
442 if ( _bps.find(bp) == -1) {
443 return JVMTI_ERROR_NOT_FOUND;
444 }
445
446 VM_ChangeBreakpoints clear_breakpoint(VM_ChangeBreakpoints::CLEAR_BREAKPOINT, &bp);
447 VMThread::execute(&clear_breakpoint);
448 return JVMTI_ERROR_NONE;
449 }
450
451 void JvmtiBreakpoints::clearall_in_class_at_safepoint(Klass* klass) {
452 bool changed = true;
453 // We are going to run thru the list of bkpts
454 // and delete some. This deletion probably alters
455 // the list in some implementation defined way such
456 // that when we delete entry i, the next entry might
457 // no longer be at i+1. To be safe, each time we delete
458 // an entry, we'll just start again from the beginning.
459 // We'll stop when we make a pass thru the whole list without
460 // deleting anything.
461 while (changed) {
462 int len = _bps.length();
463 changed = false;
464 for (int i = 0; i < len; i++) {
465 JvmtiBreakpoint& bp = _bps.at(i);
466 if (bp.method()->method_holder() == klass) {
467 bp.clear();
468 _bps.remove(i);
469 // This changed 'i' so we have to start over.
470 changed = true;
471 break;
472 }
473 }
474 }
475 }
476
477 //
478 // class JvmtiCurrentBreakpoints
479 //
480
481 JvmtiBreakpoints *JvmtiCurrentBreakpoints::_jvmti_breakpoints = NULL;
482 address * JvmtiCurrentBreakpoints::_breakpoint_list = NULL;
483
484
485 JvmtiBreakpoints& JvmtiCurrentBreakpoints::get_jvmti_breakpoints() {
486 if (_jvmti_breakpoints != NULL) return (*_jvmti_breakpoints);
487 _jvmti_breakpoints = new JvmtiBreakpoints(listener_fun);
488 assert(_jvmti_breakpoints != NULL, "_jvmti_breakpoints != NULL");
489 return (*_jvmti_breakpoints);
490 }
491
492 void JvmtiCurrentBreakpoints::listener_fun(void *this_obj, address *cache) {
493 JvmtiBreakpoints *this_jvmti = (JvmtiBreakpoints *) this_obj;
494 assert(this_jvmti != NULL, "this_jvmti != NULL");
495
496 debug_only(int n = this_jvmti->length(););
497 assert(cache[n] == NULL, "cache must be NULL terminated");
498
499 set_breakpoint_list(cache);
500 }
501
502
503 void JvmtiCurrentBreakpoints::oops_do(OopClosure* f) {
504 if (_jvmti_breakpoints != NULL) {
505 _jvmti_breakpoints->oops_do(f);
506 }
507 }
508
509 void JvmtiCurrentBreakpoints::metadata_do(void f(Metadata*)) {
510 if (_jvmti_breakpoints != NULL) {
511 _jvmti_breakpoints->metadata_do(f);
512 }
513 }
514
515 void JvmtiCurrentBreakpoints::gc_epilogue() {
516 if (_jvmti_breakpoints != NULL) {
517 _jvmti_breakpoints->gc_epilogue();
518 }
519 }
520
521 ///////////////////////////////////////////////////////////////
522 //
523 // class VM_GetOrSetLocal
524 //
525
526 // Constructor for non-object getter
527 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, jint depth, int index, BasicType type)
528 : _thread(thread)
529 , _calling_thread(NULL)
530 , _depth(depth)
531 , _index(index)
532 , _type(type)
533 , _set(false)
534 , _jvf(NULL)
535 , _result(JVMTI_ERROR_NONE)
536 {
537 }
538
539 // Constructor for object or non-object setter
540 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, jint depth, int index, BasicType type, jvalue value)
541 : _thread(thread)
542 , _calling_thread(NULL)
543 , _depth(depth)
544 , _index(index)
545 , _type(type)
546 , _value(value)
547 , _set(true)
548 , _jvf(NULL)
549 , _result(JVMTI_ERROR_NONE)
550 {
551 }
552
553 // Constructor for object getter
554 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, JavaThread* calling_thread, jint depth, int index)
555 : _thread(thread)
556 , _calling_thread(calling_thread)
557 , _depth(depth)
558 , _index(index)
559 , _type(T_OBJECT)
560 , _set(false)
561 , _jvf(NULL)
562 , _result(JVMTI_ERROR_NONE)
563 {
564 }
565
566 vframe *VM_GetOrSetLocal::get_vframe() {
567 if (!_thread->has_last_Java_frame()) {
568 return NULL;
569 }
570 RegisterMap reg_map(_thread);
571 vframe *vf = _thread->last_java_vframe(®_map);
572 int d = 0;
573 while ((vf != NULL) && (d < _depth)) {
574 vf = vf->java_sender();
575 d++;
576 }
577 return vf;
578 }
579
580 javaVFrame *VM_GetOrSetLocal::get_java_vframe() {
581 vframe* vf = get_vframe();
582 if (vf == NULL) {
583 _result = JVMTI_ERROR_NO_MORE_FRAMES;
584 return NULL;
585 }
586 javaVFrame *jvf = (javaVFrame*)vf;
587
588 if (!vf->is_java_frame()) {
589 _result = JVMTI_ERROR_OPAQUE_FRAME;
590 return NULL;
591 }
592 return jvf;
593 }
594
595 // Check that the klass is assignable to a type with the given signature.
596 // Another solution could be to use the function Klass::is_subtype_of(type).
597 // But the type class can be forced to load/initialize eagerly in such a case.
598 // This may cause unexpected consequences like CFLH or class-init JVMTI events.
599 // It is better to avoid such a behavior.
600 bool VM_GetOrSetLocal::is_assignable(const char* ty_sign, Klass* klass, Thread* thread) {
601 assert(ty_sign != NULL, "type signature must not be NULL");
602 assert(thread != NULL, "thread must not be NULL");
603 assert(klass != NULL, "klass must not be NULL");
604
605 int len = (int) strlen(ty_sign);
606 if (ty_sign[0] == 'L' && ty_sign[len-1] == ';') { // Need pure class/interface name
607 ty_sign++;
608 len -= 2;
609 }
610 TempNewSymbol ty_sym = SymbolTable::new_symbol(ty_sign, len, thread);
611 if (klass->name() == ty_sym) {
612 return true;
613 }
614 // Compare primary supers
615 int super_depth = klass->super_depth();
616 int idx;
617 for (idx = 0; idx < super_depth; idx++) {
618 if (klass->primary_super_of_depth(idx)->name() == ty_sym) {
619 return true;
620 }
621 }
622 // Compare secondary supers
623 Array<Klass*>* sec_supers = klass->secondary_supers();
624 for (idx = 0; idx < sec_supers->length(); idx++) {
625 if (((Klass*) sec_supers->at(idx))->name() == ty_sym) {
626 return true;
627 }
628 }
629 return false;
630 }
631
632 // Checks error conditions:
633 // JVMTI_ERROR_INVALID_SLOT
634 // JVMTI_ERROR_TYPE_MISMATCH
635 // Returns: 'true' - everything is Ok, 'false' - error code
636
637 bool VM_GetOrSetLocal::check_slot_type(javaVFrame* jvf) {
638 Method* method_oop = jvf->method();
639 if (!method_oop->has_localvariable_table()) {
640 // Just to check index boundaries
641 jint extra_slot = (_type == T_LONG || _type == T_DOUBLE) ? 1 : 0;
642 if (_index < 0 || _index + extra_slot >= method_oop->max_locals()) {
643 _result = JVMTI_ERROR_INVALID_SLOT;
644 return false;
645 }
646 return true;
647 }
648
649 jint num_entries = method_oop->localvariable_table_length();
650 if (num_entries == 0) {
651 _result = JVMTI_ERROR_INVALID_SLOT;
652 return false; // There are no slots
653 }
654 int signature_idx = -1;
655 int vf_bci = jvf->bci();
656 LocalVariableTableElement* table = method_oop->localvariable_table_start();
657 for (int i = 0; i < num_entries; i++) {
658 int start_bci = table[i].start_bci;
659 int end_bci = start_bci + table[i].length;
660
661 // Here we assume that locations of LVT entries
662 // with the same slot number cannot be overlapped
663 if (_index == (jint) table[i].slot && start_bci <= vf_bci && vf_bci <= end_bci) {
664 signature_idx = (int) table[i].descriptor_cp_index;
665 break;
666 }
667 }
668 if (signature_idx == -1) {
669 _result = JVMTI_ERROR_INVALID_SLOT;
670 return false; // Incorrect slot index
671 }
672 Symbol* sign_sym = method_oop->constants()->symbol_at(signature_idx);
673 const char* signature = (const char *) sign_sym->as_utf8();
674 BasicType slot_type = char2type(signature[0]);
675
676 switch (slot_type) {
677 case T_BYTE:
678 case T_SHORT:
679 case T_CHAR:
680 case T_BOOLEAN:
681 slot_type = T_INT;
682 break;
683 case T_ARRAY:
684 slot_type = T_OBJECT;
685 break;
686 default:
687 break;
688 };
689 if (_type != slot_type) {
690 _result = JVMTI_ERROR_TYPE_MISMATCH;
691 return false;
692 }
693
694 jobject jobj = _value.l;
695 if (_set && slot_type == T_OBJECT && jobj != NULL) { // NULL reference is allowed
696 // Check that the jobject class matches the return type signature.
697 JavaThread* cur_thread = JavaThread::current();
698 HandleMark hm(cur_thread);
699
700 Handle obj(cur_thread, JNIHandles::resolve_external_guard(jobj));
701 NULL_CHECK(obj, (_result = JVMTI_ERROR_INVALID_OBJECT, false));
702 Klass* ob_k = obj->klass();
703 NULL_CHECK(ob_k, (_result = JVMTI_ERROR_INVALID_OBJECT, false));
704
705 if (!is_assignable(signature, ob_k, cur_thread)) {
706 _result = JVMTI_ERROR_TYPE_MISMATCH;
707 return false;
708 }
709 }
710 return true;
711 }
712
713 static bool can_be_deoptimized(vframe* vf) {
714 return (vf->is_compiled_frame() && vf->fr().can_be_deoptimized());
715 }
716
717 bool VM_GetOrSetLocal::doit_prologue() {
718 _jvf = get_java_vframe();
719 NULL_CHECK(_jvf, false);
720
721 if (_jvf->method()->is_native()) {
722 if (getting_receiver() && !_jvf->method()->is_static()) {
723 return true;
724 } else {
725 _result = JVMTI_ERROR_OPAQUE_FRAME;
726 return false;
727 }
728 }
729
730 if (!check_slot_type(_jvf)) {
731 return false;
732 }
733 return true;
734 }
735
736 void VM_GetOrSetLocal::doit() {
737 InterpreterOopMap oop_mask;
738 _jvf->method()->mask_for(_jvf->bci(), &oop_mask);
739 if (oop_mask.is_dead(_index)) {
740 // The local can be invalid and uninitialized in the scope of current bci
741 _result = JVMTI_ERROR_INVALID_SLOT;
742 return;
743 }
744 if (_set) {
745 // Force deoptimization of frame if compiled because it's
746 // possible the compiler emitted some locals as constant values,
747 // meaning they are not mutable.
748 if (can_be_deoptimized(_jvf)) {
749
750 // Schedule deoptimization so that eventually the local
751 // update will be written to an interpreter frame.
752 Deoptimization::deoptimize_frame(_jvf->thread(), _jvf->fr().id());
753
754 // Now store a new value for the local which will be applied
755 // once deoptimization occurs. Note however that while this
756 // write is deferred until deoptimization actually happens
757 // can vframe created after this point will have its locals
758 // reflecting this update so as far as anyone can see the
759 // write has already taken place.
760
761 // If we are updating an oop then get the oop from the handle
762 // since the handle will be long gone by the time the deopt
763 // happens. The oop stored in the deferred local will be
764 // gc'd on its own.
765 if (_type == T_OBJECT) {
766 _value.l = (jobject) (JNIHandles::resolve_external_guard(_value.l));
767 }
768 // Re-read the vframe so we can see that it is deoptimized
769 // [ Only need because of assert in update_local() ]
770 _jvf = get_java_vframe();
771 ((compiledVFrame*)_jvf)->update_local(_type, _index, _value);
772 return;
773 }
774 StackValueCollection *locals = _jvf->locals();
775 HandleMark hm;
776
777 switch (_type) {
778 case T_INT: locals->set_int_at (_index, _value.i); break;
779 case T_LONG: locals->set_long_at (_index, _value.j); break;
780 case T_FLOAT: locals->set_float_at (_index, _value.f); break;
781 case T_DOUBLE: locals->set_double_at(_index, _value.d); break;
782 case T_OBJECT: {
783 Handle ob_h(Thread::current(), JNIHandles::resolve_external_guard(_value.l));
784 locals->set_obj_at (_index, ob_h);
785 break;
786 }
787 default: ShouldNotReachHere();
788 }
789 _jvf->set_locals(locals);
790 } else {
791 if (_jvf->method()->is_native() && _jvf->is_compiled_frame()) {
792 assert(getting_receiver(), "Can only get here when getting receiver");
793 oop receiver = _jvf->fr().get_native_receiver();
794 _value.l = JNIHandles::make_local(_calling_thread, receiver);
795 } else {
796 StackValueCollection *locals = _jvf->locals();
797
798 if (locals->at(_index)->type() == T_CONFLICT) {
799 memset(&_value, 0, sizeof(_value));
800 _value.l = NULL;
801 return;
802 }
803
804 switch (_type) {
805 case T_INT: _value.i = locals->int_at (_index); break;
806 case T_LONG: _value.j = locals->long_at (_index); break;
807 case T_FLOAT: _value.f = locals->float_at (_index); break;
808 case T_DOUBLE: _value.d = locals->double_at(_index); break;
809 case T_OBJECT: {
810 // Wrap the oop to be returned in a local JNI handle since
811 // oops_do() no longer applies after doit() is finished.
812 oop obj = locals->obj_at(_index)();
813 _value.l = JNIHandles::make_local(_calling_thread, obj);
814 break;
815 }
816 default: ShouldNotReachHere();
817 }
818 }
819 }
820 }
821
822
823 bool VM_GetOrSetLocal::allow_nested_vm_operations() const {
824 return true; // May need to deoptimize
825 }
826
827
828 VM_GetReceiver::VM_GetReceiver(
829 JavaThread* thread, JavaThread* caller_thread, jint depth)
830 : VM_GetOrSetLocal(thread, caller_thread, depth, 0) {}
831
832 /////////////////////////////////////////////////////////////////////////////////////////
833
834 //
835 // class JvmtiSuspendControl - see comments in jvmtiImpl.hpp
836 //
837
838 bool JvmtiSuspendControl::suspend(JavaThread *java_thread) {
839 // external suspend should have caught suspending a thread twice
840
841 // Immediate suspension required for JPDA back-end so JVMTI agent threads do
842 // not deadlock due to later suspension on transitions while holding
843 // raw monitors. Passing true causes the immediate suspension.
844 // java_suspend() will catch threads in the process of exiting
845 // and will ignore them.
846 java_thread->java_suspend();
847
848 // It would be nice to have the following assertion in all the time,
849 // but it is possible for a racing resume request to have resumed
850 // this thread right after we suspended it. Temporarily enable this
851 // assertion if you are chasing a different kind of bug.
852 //
853 // assert(java_lang_Thread::thread(java_thread->threadObj()) == NULL ||
854 // java_thread->is_being_ext_suspended(), "thread is not suspended");
855
856 if (java_lang_Thread::thread(java_thread->threadObj()) == NULL) {
857 // check again because we can get delayed in java_suspend():
858 // the thread is in process of exiting.
859 return false;
860 }
861
862 return true;
863 }
864
865 bool JvmtiSuspendControl::resume(JavaThread *java_thread) {
866 // external suspend should have caught resuming a thread twice
867 assert(java_thread->is_being_ext_suspended(), "thread should be suspended");
868
869 // resume thread
870 {
871 // must always grab Threads_lock, see JVM_SuspendThread
872 MutexLocker ml(Threads_lock);
873 java_thread->java_resume();
874 }
875
876 return true;
877 }
878
879
880 void JvmtiSuspendControl::print() {
881 #ifndef PRODUCT
882 LogStreamHandle(Trace, jvmti) log_stream;
883 log_stream.print("Suspended Threads: [");
884 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *thread = jtiwh.next(); ) {
885 #ifdef JVMTI_TRACE
886 const char *name = JvmtiTrace::safe_get_thread_name(thread);
887 #else
888 const char *name = "";
889 #endif /*JVMTI_TRACE */
890 log_stream.print("%s(%c ", name, thread->is_being_ext_suspended() ? 'S' : '_');
891 if (!thread->has_last_Java_frame()) {
892 log_stream.print("no stack");
893 }
894 log_stream.print(") ");
895 }
896 log_stream.print_cr("]");
897 #endif
898 }
899
900 JvmtiDeferredEvent JvmtiDeferredEvent::compiled_method_load_event(
901 nmethod* nm) {
902 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_COMPILED_METHOD_LOAD);
903 event._event_data.compiled_method_load = nm;
904 // Keep the nmethod alive until the ServiceThread can process
905 // this deferred event.
906 nmethodLocker::lock_nmethod(nm);
907 return event;
908 }
909
910 JvmtiDeferredEvent JvmtiDeferredEvent::compiled_method_unload_event(
911 nmethod* nm, jmethodID id, const void* code) {
912 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_COMPILED_METHOD_UNLOAD);
913 event._event_data.compiled_method_unload.nm = nm;
914 event._event_data.compiled_method_unload.method_id = id;
915 event._event_data.compiled_method_unload.code_begin = code;
916 // Keep the nmethod alive until the ServiceThread can process
917 // this deferred event. This will keep the memory for the
918 // generated code from being reused too early. We pass
919 // zombie_ok == true here so that our nmethod that was just
920 // made into a zombie can be locked.
921 nmethodLocker::lock_nmethod(nm, true /* zombie_ok */);
922 return event;
923 }
924
925 JvmtiDeferredEvent JvmtiDeferredEvent::dynamic_code_generated_event(
926 const char* name, const void* code_begin, const void* code_end) {
927 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_DYNAMIC_CODE_GENERATED);
928 // Need to make a copy of the name since we don't know how long
929 // the event poster will keep it around after we enqueue the
930 // deferred event and return. strdup() failure is handled in
931 // the post() routine below.
932 event._event_data.dynamic_code_generated.name = os::strdup(name);
933 event._event_data.dynamic_code_generated.code_begin = code_begin;
934 event._event_data.dynamic_code_generated.code_end = code_end;
935 return event;
936 }
937
938 void JvmtiDeferredEvent::post() {
939 assert(ServiceThread::is_service_thread(Thread::current()),
940 "Service thread must post enqueued events");
941 switch(_type) {
942 case TYPE_COMPILED_METHOD_LOAD: {
943 nmethod* nm = _event_data.compiled_method_load;
944 JvmtiExport::post_compiled_method_load(nm);
945 // done with the deferred event so unlock the nmethod
946 nmethodLocker::unlock_nmethod(nm);
947 break;
948 }
949 case TYPE_COMPILED_METHOD_UNLOAD: {
950 nmethod* nm = _event_data.compiled_method_unload.nm;
951 JvmtiExport::post_compiled_method_unload(
952 _event_data.compiled_method_unload.method_id,
953 _event_data.compiled_method_unload.code_begin);
954 // done with the deferred event so unlock the nmethod
955 nmethodLocker::unlock_nmethod(nm);
956 break;
957 }
958 case TYPE_DYNAMIC_CODE_GENERATED: {
959 JvmtiExport::post_dynamic_code_generated_internal(
960 // if strdup failed give the event a default name
961 (_event_data.dynamic_code_generated.name == NULL)
962 ? "unknown_code" : _event_data.dynamic_code_generated.name,
963 _event_data.dynamic_code_generated.code_begin,
964 _event_data.dynamic_code_generated.code_end);
965 if (_event_data.dynamic_code_generated.name != NULL) {
966 // release our copy
967 os::free((void *)_event_data.dynamic_code_generated.name);
968 }
969 break;
970 }
971 default:
972 ShouldNotReachHere();
973 }
974 }
975
976 JvmtiDeferredEventQueue::QueueNode* JvmtiDeferredEventQueue::_queue_tail = NULL;
977 JvmtiDeferredEventQueue::QueueNode* JvmtiDeferredEventQueue::_queue_head = NULL;
978
979 bool JvmtiDeferredEventQueue::has_events() {
980 assert(Service_lock->owned_by_self(), "Must own Service_lock");
981 return _queue_head != NULL;
982 }
983
984 void JvmtiDeferredEventQueue::enqueue(const JvmtiDeferredEvent& event) {
985 assert(Service_lock->owned_by_self(), "Must own Service_lock");
986
987 // Events get added to the end of the queue (and are pulled off the front).
988 QueueNode* node = new QueueNode(event);
989 if (_queue_tail == NULL) {
990 _queue_tail = _queue_head = node;
991 } else {
992 assert(_queue_tail->next() == NULL, "Must be the last element in the list");
993 _queue_tail->set_next(node);
994 _queue_tail = node;
995 }
996
997 Service_lock->notify_all();
998 assert((_queue_head == NULL) == (_queue_tail == NULL),
999 "Inconsistent queue markers");
1000 }
1001
1002 JvmtiDeferredEvent JvmtiDeferredEventQueue::dequeue() {
1003 assert(Service_lock->owned_by_self(), "Must own Service_lock");
1004
1005 assert(_queue_head != NULL, "Nothing to dequeue");
1006
1007 if (_queue_head == NULL) {
1008 // Just in case this happens in product; it shouldn't but let's not crash
1009 return JvmtiDeferredEvent();
1010 }
1011
1012 QueueNode* node = _queue_head;
1013 _queue_head = _queue_head->next();
1014 if (_queue_head == NULL) {
1015 _queue_tail = NULL;
1016 }
1017
1018 assert((_queue_head == NULL) == (_queue_tail == NULL),
1019 "Inconsistent queue markers");
1020
1021 JvmtiDeferredEvent event = node->event();
1022 delete node;
1023 return event;
1024 }