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 "jvmtifiles/jvmtiEnv.hpp"
29 #include "memory/resourceArea.hpp"
30 #include "oops/instanceKlass.hpp"
31 #include "prims/jvmtiAgentThread.hpp"
32 #include "prims/jvmtiEventController.inline.hpp"
33 #include "prims/jvmtiImpl.hpp"
34 #include "prims/jvmtiRedefineClasses.hpp"
35 #include "runtime/atomic.hpp"
36 #include "runtime/deoptimization.hpp"
37 #include "runtime/handles.hpp"
38 #include "runtime/handles.inline.hpp"
39 #include "runtime/interfaceSupport.hpp"
40 #include "runtime/javaCalls.hpp"
41 #include "runtime/os.hpp"
42 #include "runtime/serviceThread.hpp"
43 #include "runtime/signature.hpp"
44 #include "runtime/thread.inline.hpp"
45 #include "runtime/vframe.hpp"
46 #include "runtime/vframe_hp.hpp"
47 #include "runtime/vm_operations.hpp"
48 #include "utilities/exceptions.hpp"
49
50 //
51 // class JvmtiAgentThread
52 //
53 // JavaThread used to wrap a thread started by an agent
54 // using the JVMTI method RunAgentThread.
55 //
56
57 JvmtiAgentThread::JvmtiAgentThread(JvmtiEnv* env, jvmtiStartFunction start_fn, const void *start_arg)
58 : JavaThread(start_function_wrapper) {
59 _env = env;
60 _start_fn = start_fn;
61 _start_arg = start_arg;
62 }
63
64 void
65 JvmtiAgentThread::start_function_wrapper(JavaThread *thread, TRAPS) {
66 // It is expected that any Agent threads will be created as
67 // Java Threads. If this is the case, notification of the creation
68 // of the thread is given in JavaThread::thread_main().
69 assert(thread->is_Java_thread(), "debugger thread should be a Java Thread");
70 assert(thread == JavaThread::current(), "sanity check");
71
72 JvmtiAgentThread *dthread = (JvmtiAgentThread *)thread;
73 dthread->call_start_function();
74 }
75
76 void
77 JvmtiAgentThread::call_start_function() {
78 ThreadToNativeFromVM transition(this);
79 _start_fn(_env->jvmti_external(), jni_environment(), (void*)_start_arg);
80 }
81
82
83 //
84 // class GrowableCache - private methods
85 //
86
87 void GrowableCache::recache() {
88 int len = _elements->length();
89
90 FREE_C_HEAP_ARRAY(address, _cache, mtInternal);
91 _cache = NEW_C_HEAP_ARRAY(address,len+1, mtInternal);
92
93 for (int i=0; i<len; i++) {
94 _cache[i] = _elements->at(i)->getCacheValue();
95 //
96 // The cache entry has gone bad. Without a valid frame pointer
97 // value, the entry is useless so we simply delete it in product
98 // mode. The call to remove() will rebuild the cache again
99 // without the bad entry.
100 //
101 if (_cache[i] == NULL) {
102 assert(false, "cannot recache NULL elements");
103 remove(i);
104 return;
105 }
106 }
107 _cache[len] = NULL;
108
109 _listener_fun(_this_obj,_cache);
110 }
111
112 bool GrowableCache::equals(void* v, GrowableElement *e2) {
113 GrowableElement *e1 = (GrowableElement *) v;
114 assert(e1 != NULL, "e1 != NULL");
115 assert(e2 != NULL, "e2 != NULL");
116
117 return e1->equals(e2);
118 }
119
120 //
121 // class GrowableCache - public methods
122 //
123
124 GrowableCache::GrowableCache() {
125 _this_obj = NULL;
126 _listener_fun = NULL;
127 _elements = NULL;
128 _cache = NULL;
129 }
130
131 GrowableCache::~GrowableCache() {
132 clear();
133 delete _elements;
134 FREE_C_HEAP_ARRAY(address, _cache, mtInternal);
135 }
136
137 void GrowableCache::initialize(void *this_obj, void listener_fun(void *, address*) ) {
138 _this_obj = this_obj;
139 _listener_fun = listener_fun;
140 _elements = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<GrowableElement*>(5,true);
141 recache();
142 }
143
144 // number of elements in the collection
145 int GrowableCache::length() {
146 return _elements->length();
147 }
148
149 // get the value of the index element in the collection
150 GrowableElement* GrowableCache::at(int index) {
151 GrowableElement *e = (GrowableElement *) _elements->at(index);
152 assert(e != NULL, "e != NULL");
153 return e;
154 }
155
156 int GrowableCache::find(GrowableElement* e) {
157 return _elements->find(e, GrowableCache::equals);
158 }
159
160 // append a copy of the element to the end of the collection
161 void GrowableCache::append(GrowableElement* e) {
162 GrowableElement *new_e = e->clone();
163 _elements->append(new_e);
164 recache();
165 }
166
167 // insert a copy of the element using lessthan()
168 void GrowableCache::insert(GrowableElement* e) {
169 GrowableElement *new_e = e->clone();
170 _elements->append(new_e);
171
172 int n = length()-2;
173 for (int i=n; i>=0; i--) {
174 GrowableElement *e1 = _elements->at(i);
175 GrowableElement *e2 = _elements->at(i+1);
176 if (e2->lessThan(e1)) {
177 _elements->at_put(i+1, e1);
178 _elements->at_put(i, e2);
179 }
180 }
181
182 recache();
183 }
184
185 // remove the element at index
186 void GrowableCache::remove (int index) {
187 GrowableElement *e = _elements->at(index);
188 assert(e != NULL, "e != NULL");
189 _elements->remove(e);
190 delete e;
191 recache();
192 }
193
194 // clear out all elements, release all heap space and
195 // let our listener know that things have changed.
196 void GrowableCache::clear() {
197 int len = _elements->length();
198 for (int i=0; i<len; i++) {
199 delete _elements->at(i);
200 }
201 _elements->clear();
202 recache();
203 }
204
205 void GrowableCache::oops_do(OopClosure* f) {
206 int len = _elements->length();
207 for (int i=0; i<len; i++) {
208 GrowableElement *e = _elements->at(i);
209 e->oops_do(f);
210 }
211 }
212
213 void GrowableCache::metadata_do(void f(Metadata*)) {
214 int len = _elements->length();
215 for (int i=0; i<len; i++) {
216 GrowableElement *e = _elements->at(i);
217 e->metadata_do(f);
218 }
219 }
220
221 void GrowableCache::gc_epilogue() {
222 int len = _elements->length();
223 for (int i=0; i<len; i++) {
224 _cache[i] = _elements->at(i)->getCacheValue();
225 }
226 }
227
228 //
229 // class JvmtiBreakpoint
230 //
231
232 JvmtiBreakpoint::JvmtiBreakpoint() {
233 _method = NULL;
234 _bci = 0;
235 _class_holder = NULL;
236 }
237
238 JvmtiBreakpoint::JvmtiBreakpoint(Method* m_method, jlocation location) {
239 _method = m_method;
240 _class_holder = _method->method_holder()->klass_holder();
241 #ifdef CHECK_UNHANDLED_OOPS
242 // _class_holder can't be wrapped in a Handle, because JvmtiBreakpoints are
243 // sometimes allocated on the heap.
244 //
245 // The code handling JvmtiBreakpoints allocated on the stack can't be
246 // interrupted by a GC until _class_holder is reachable by the GC via the
247 // oops_do method.
248 Thread::current()->allow_unhandled_oop(&_class_holder);
249 #endif // CHECK_UNHANDLED_OOPS
250 assert(_method != NULL, "_method != NULL");
251 _bci = (int) location;
252 assert(_bci >= 0, "_bci >= 0");
253 }
254
255 void JvmtiBreakpoint::copy(JvmtiBreakpoint& bp) {
256 _method = bp._method;
257 _bci = bp._bci;
258 _class_holder = bp._class_holder;
259 }
260
261 bool JvmtiBreakpoint::lessThan(JvmtiBreakpoint& bp) {
262 Unimplemented();
263 return false;
264 }
265
266 bool JvmtiBreakpoint::equals(JvmtiBreakpoint& bp) {
267 return _method == bp._method
268 && _bci == bp._bci;
269 }
270
271 bool JvmtiBreakpoint::is_valid() {
272 // class loader can be NULL
273 return _method != NULL &&
274 _bci >= 0;
275 }
276
277 address JvmtiBreakpoint::getBcp() {
278 return _method->bcp_from(_bci);
279 }
280
281 void JvmtiBreakpoint::each_method_version_do(method_action meth_act) {
282 ((Method*)_method->*meth_act)(_bci);
283
284 // add/remove breakpoint to/from versions of the method that
285 // are EMCP. Directly or transitively obsolete methods are
286 // not saved in the PreviousVersionNodes.
287 Thread *thread = Thread::current();
288 instanceKlassHandle ikh = instanceKlassHandle(thread, _method->method_holder());
289 Symbol* m_name = _method->name();
290 Symbol* m_signature = _method->signature();
291
292 // search previous versions if they exist
293 PreviousVersionWalker pvw(thread, (InstanceKlass *)ikh());
294 for (PreviousVersionNode * pv_node = pvw.next_previous_version();
295 pv_node != NULL; pv_node = pvw.next_previous_version()) {
296 GrowableArray<Method*>* methods = pv_node->prev_EMCP_methods();
297
298 if (methods == NULL) {
299 // We have run into a PreviousVersion generation where
300 // all methods were made obsolete during that generation's
301 // RedefineClasses() operation. At the time of that
302 // operation, all EMCP methods were flushed so we don't
303 // have to go back any further.
304 //
305 // A NULL methods array is different than an empty methods
306 // array. We cannot infer any optimizations about older
307 // generations from an empty methods array for the current
308 // generation.
309 break;
310 }
311
312 for (int i = methods->length() - 1; i >= 0; i--) {
313 Method* method = methods->at(i);
314 // obsolete methods that are running are not deleted from
315 // previous version array, but they are skipped here.
316 if (!method->is_obsolete() &&
317 method->name() == m_name &&
318 method->signature() == m_signature) {
319 RC_TRACE(0x00000800, ("%sing breakpoint in %s(%s)",
320 meth_act == &Method::set_breakpoint ? "sett" : "clear",
321 method->name()->as_C_string(),
322 method->signature()->as_C_string()));
323
324 (method->*meth_act)(_bci);
325 break;
326 }
327 }
328 }
329 }
330
331 void JvmtiBreakpoint::set() {
332 each_method_version_do(&Method::set_breakpoint);
333 }
334
335 void JvmtiBreakpoint::clear() {
336 each_method_version_do(&Method::clear_breakpoint);
337 }
338
339 void JvmtiBreakpoint::print() {
340 #ifndef PRODUCT
341 const char *class_name = (_method == NULL) ? "NULL" : _method->klass_name()->as_C_string();
342 const char *method_name = (_method == NULL) ? "NULL" : _method->name()->as_C_string();
343
344 tty->print("Breakpoint(%s,%s,%d,%p)",class_name, method_name, _bci, getBcp());
345 #endif
346 }
347
348
349 //
350 // class VM_ChangeBreakpoints
351 //
352 // Modify the Breakpoints data structure at a safepoint
353 //
354
355 void VM_ChangeBreakpoints::doit() {
356 switch (_operation) {
357 case SET_BREAKPOINT:
358 _breakpoints->set_at_safepoint(*_bp);
359 break;
360 case CLEAR_BREAKPOINT:
361 _breakpoints->clear_at_safepoint(*_bp);
362 break;
363 default:
364 assert(false, "Unknown operation");
365 }
366 }
367
368 void VM_ChangeBreakpoints::oops_do(OopClosure* f) {
369 // The JvmtiBreakpoints in _breakpoints will be visited via
370 // JvmtiExport::oops_do.
371 if (_bp != NULL) {
372 _bp->oops_do(f);
373 }
374 }
375
376 void VM_ChangeBreakpoints::metadata_do(void f(Metadata*)) {
377 // Walk metadata in breakpoints to keep from being deallocated with RedefineClasses
378 if (_bp != NULL) {
379 _bp->metadata_do(f);
380 }
381 }
382
383 //
384 // class JvmtiBreakpoints
385 //
386 // a JVMTI internal collection of JvmtiBreakpoint
387 //
388
389 JvmtiBreakpoints::JvmtiBreakpoints(void listener_fun(void *,address *)) {
390 _bps.initialize(this,listener_fun);
391 }
392
393 JvmtiBreakpoints:: ~JvmtiBreakpoints() {}
394
395 void JvmtiBreakpoints::oops_do(OopClosure* f) {
396 _bps.oops_do(f);
397 }
398
399 void JvmtiBreakpoints::metadata_do(void f(Metadata*)) {
400 _bps.metadata_do(f);
401 }
402
403 void JvmtiBreakpoints::gc_epilogue() {
404 _bps.gc_epilogue();
405 }
406
407 void JvmtiBreakpoints::print() {
408 #ifndef PRODUCT
409 ResourceMark rm;
410
411 int n = _bps.length();
412 for (int i=0; i<n; i++) {
413 JvmtiBreakpoint& bp = _bps.at(i);
414 tty->print("%d: ", i);
415 bp.print();
416 tty->cr();
417 }
418 #endif
419 }
420
421
422 void JvmtiBreakpoints::set_at_safepoint(JvmtiBreakpoint& bp) {
423 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
424
425 int i = _bps.find(bp);
426 if (i == -1) {
427 _bps.append(bp);
428 bp.set();
429 }
430 }
431
432 void JvmtiBreakpoints::clear_at_safepoint(JvmtiBreakpoint& bp) {
433 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
434
435 int i = _bps.find(bp);
436 if (i != -1) {
437 _bps.remove(i);
438 bp.clear();
439 }
440 }
441
442 int JvmtiBreakpoints::length() { return _bps.length(); }
443
444 int JvmtiBreakpoints::set(JvmtiBreakpoint& bp) {
445 if ( _bps.find(bp) != -1) {
446 return JVMTI_ERROR_DUPLICATE;
447 }
448 VM_ChangeBreakpoints set_breakpoint(VM_ChangeBreakpoints::SET_BREAKPOINT, &bp);
449 VMThread::execute(&set_breakpoint);
450 return JVMTI_ERROR_NONE;
451 }
452
453 int JvmtiBreakpoints::clear(JvmtiBreakpoint& bp) {
454 if ( _bps.find(bp) == -1) {
455 return JVMTI_ERROR_NOT_FOUND;
456 }
457
458 VM_ChangeBreakpoints clear_breakpoint(VM_ChangeBreakpoints::CLEAR_BREAKPOINT, &bp);
459 VMThread::execute(&clear_breakpoint);
460 return JVMTI_ERROR_NONE;
461 }
462
463 void JvmtiBreakpoints::clearall_in_class_at_safepoint(Klass* klass) {
464 bool changed = true;
465 // We are going to run thru the list of bkpts
466 // and delete some. This deletion probably alters
467 // the list in some implementation defined way such
468 // that when we delete entry i, the next entry might
469 // no longer be at i+1. To be safe, each time we delete
470 // an entry, we'll just start again from the beginning.
471 // We'll stop when we make a pass thru the whole list without
472 // deleting anything.
473 while (changed) {
474 int len = _bps.length();
475 changed = false;
476 for (int i = 0; i < len; i++) {
477 JvmtiBreakpoint& bp = _bps.at(i);
478 if (bp.method()->method_holder() == klass) {
479 bp.clear();
480 _bps.remove(i);
481 // This changed 'i' so we have to start over.
482 changed = true;
483 break;
484 }
485 }
486 }
487 }
488
489 //
490 // class JvmtiCurrentBreakpoints
491 //
492
493 JvmtiBreakpoints *JvmtiCurrentBreakpoints::_jvmti_breakpoints = NULL;
494 address * JvmtiCurrentBreakpoints::_breakpoint_list = NULL;
495
496
497 JvmtiBreakpoints& JvmtiCurrentBreakpoints::get_jvmti_breakpoints() {
498 if (_jvmti_breakpoints != NULL) return (*_jvmti_breakpoints);
499 _jvmti_breakpoints = new JvmtiBreakpoints(listener_fun);
500 assert(_jvmti_breakpoints != NULL, "_jvmti_breakpoints != NULL");
501 return (*_jvmti_breakpoints);
502 }
503
504 void JvmtiCurrentBreakpoints::listener_fun(void *this_obj, address *cache) {
505 JvmtiBreakpoints *this_jvmti = (JvmtiBreakpoints *) this_obj;
506 assert(this_jvmti != NULL, "this_jvmti != NULL");
507
508 debug_only(int n = this_jvmti->length(););
509 assert(cache[n] == NULL, "cache must be NULL terminated");
510
511 set_breakpoint_list(cache);
512 }
513
514
515 void JvmtiCurrentBreakpoints::oops_do(OopClosure* f) {
516 if (_jvmti_breakpoints != NULL) {
517 _jvmti_breakpoints->oops_do(f);
518 }
519 }
520
521 void JvmtiCurrentBreakpoints::metadata_do(void f(Metadata*)) {
522 if (_jvmti_breakpoints != NULL) {
523 _jvmti_breakpoints->metadata_do(f);
524 }
525 }
526
527 void JvmtiCurrentBreakpoints::gc_epilogue() {
528 if (_jvmti_breakpoints != NULL) {
529 _jvmti_breakpoints->gc_epilogue();
530 }
531 }
532
533 ///////////////////////////////////////////////////////////////
534 //
535 // class VM_GetOrSetLocal
536 //
537
538 // Constructor for non-object getter
539 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, jint depth, int index, BasicType type)
540 : _thread(thread)
541 , _calling_thread(NULL)
542 , _depth(depth)
543 , _index(index)
544 , _type(type)
545 , _set(false)
546 , _jvf(NULL)
547 , _result(JVMTI_ERROR_NONE)
548 {
549 }
550
551 // Constructor for object or non-object setter
552 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, jint depth, int index, BasicType type, jvalue value)
553 : _thread(thread)
554 , _calling_thread(NULL)
555 , _depth(depth)
556 , _index(index)
557 , _type(type)
558 , _value(value)
559 , _set(true)
560 , _jvf(NULL)
561 , _result(JVMTI_ERROR_NONE)
562 {
563 }
564
565 // Constructor for object getter
566 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, JavaThread* calling_thread, jint depth, int index)
567 : _thread(thread)
568 , _calling_thread(calling_thread)
569 , _depth(depth)
570 , _index(index)
571 , _type(T_OBJECT)
572 , _set(false)
573 , _jvf(NULL)
574 , _result(JVMTI_ERROR_NONE)
575 {
576 }
577
578 vframe *VM_GetOrSetLocal::get_vframe() {
579 if (!_thread->has_last_Java_frame()) {
580 return NULL;
581 }
582 RegisterMap reg_map(_thread);
583 vframe *vf = _thread->last_java_vframe(®_map);
584 int d = 0;
585 while ((vf != NULL) && (d < _depth)) {
586 vf = vf->java_sender();
587 d++;
588 }
589 return vf;
590 }
591
592 javaVFrame *VM_GetOrSetLocal::get_java_vframe() {
593 vframe* vf = get_vframe();
594 if (vf == NULL) {
595 _result = JVMTI_ERROR_NO_MORE_FRAMES;
596 return NULL;
597 }
598 javaVFrame *jvf = (javaVFrame*)vf;
599
600 if (!vf->is_java_frame()) {
601 _result = JVMTI_ERROR_OPAQUE_FRAME;
602 return NULL;
603 }
604 return jvf;
605 }
606
607 // Check that the klass is assignable to a type with the given signature.
608 // Another solution could be to use the function Klass::is_subtype_of(type).
609 // But the type class can be forced to load/initialize eagerly in such a case.
610 // This may cause unexpected consequences like CFLH or class-init JVMTI events.
611 // It is better to avoid such a behavior.
612 bool VM_GetOrSetLocal::is_assignable(const char* ty_sign, Klass* klass, Thread* thread) {
613 assert(ty_sign != NULL, "type signature must not be NULL");
614 assert(thread != NULL, "thread must not be NULL");
615 assert(klass != NULL, "klass must not be NULL");
616
617 int len = (int) strlen(ty_sign);
618 if (ty_sign[0] == 'L' && ty_sign[len-1] == ';') { // Need pure class/interface name
619 ty_sign++;
620 len -= 2;
621 }
622 TempNewSymbol ty_sym = SymbolTable::new_symbol(ty_sign, len, thread);
623 if (klass->name() == ty_sym) {
624 return true;
625 }
626 // Compare primary supers
627 int super_depth = klass->super_depth();
628 int idx;
629 for (idx = 0; idx < super_depth; idx++) {
630 if (klass->primary_super_of_depth(idx)->name() == ty_sym) {
631 return true;
632 }
633 }
634 // Compare secondary supers
635 Array<Klass*>* sec_supers = klass->secondary_supers();
636 for (idx = 0; idx < sec_supers->length(); idx++) {
637 if (((Klass*) sec_supers->at(idx))->name() == ty_sym) {
638 return true;
639 }
640 }
641 return false;
642 }
643
644 // Checks error conditions:
645 // JVMTI_ERROR_INVALID_SLOT
646 // JVMTI_ERROR_TYPE_MISMATCH
647 // Returns: 'true' - everything is Ok, 'false' - error code
648
649 bool VM_GetOrSetLocal::check_slot_type(javaVFrame* jvf) {
650 Method* method_oop = jvf->method();
651 if (!method_oop->has_localvariable_table()) {
652 // Just to check index boundaries
653 jint extra_slot = (_type == T_LONG || _type == T_DOUBLE) ? 1 : 0;
654 if (_index < 0 || _index + extra_slot >= method_oop->max_locals()) {
655 _result = JVMTI_ERROR_INVALID_SLOT;
656 return false;
657 }
658 return true;
659 }
660
661 jint num_entries = method_oop->localvariable_table_length();
662 if (num_entries == 0) {
663 _result = JVMTI_ERROR_INVALID_SLOT;
664 return false; // There are no slots
665 }
666 int signature_idx = -1;
667 int vf_bci = jvf->bci();
668 LocalVariableTableElement* table = method_oop->localvariable_table_start();
669 for (int i = 0; i < num_entries; i++) {
670 int start_bci = table[i].start_bci;
671 int end_bci = start_bci + table[i].length;
672
673 // Here we assume that locations of LVT entries
674 // with the same slot number cannot be overlapped
675 if (_index == (jint) table[i].slot && start_bci <= vf_bci && vf_bci <= end_bci) {
676 signature_idx = (int) table[i].descriptor_cp_index;
677 break;
678 }
679 }
680 if (signature_idx == -1) {
681 _result = JVMTI_ERROR_INVALID_SLOT;
682 return false; // Incorrect slot index
683 }
684 Symbol* sign_sym = method_oop->constants()->symbol_at(signature_idx);
685 const char* signature = (const char *) sign_sym->as_utf8();
686 BasicType slot_type = char2type(signature[0]);
687
688 switch (slot_type) {
689 case T_BYTE:
690 case T_SHORT:
691 case T_CHAR:
692 case T_BOOLEAN:
693 slot_type = T_INT;
694 break;
695 case T_ARRAY:
696 slot_type = T_OBJECT;
697 break;
698 };
699 if (_type != slot_type) {
700 _result = JVMTI_ERROR_TYPE_MISMATCH;
701 return false;
702 }
703
704 jobject jobj = _value.l;
705 if (_set && slot_type == T_OBJECT && jobj != NULL) { // NULL reference is allowed
706 // Check that the jobject class matches the return type signature.
707 JavaThread* cur_thread = JavaThread::current();
708 HandleMark hm(cur_thread);
709
710 Handle obj = Handle(cur_thread, JNIHandles::resolve_external_guard(jobj));
711 NULL_CHECK(obj, (_result = JVMTI_ERROR_INVALID_OBJECT, false));
712 KlassHandle ob_kh = KlassHandle(cur_thread, obj->klass());
713 NULL_CHECK(ob_kh, (_result = JVMTI_ERROR_INVALID_OBJECT, false));
714
715 if (!is_assignable(signature, ob_kh(), cur_thread)) {
716 _result = JVMTI_ERROR_TYPE_MISMATCH;
717 return false;
718 }
719 }
720 return true;
721 }
722
723 static bool can_be_deoptimized(vframe* vf) {
724 return (vf->is_compiled_frame() && vf->fr().can_be_deoptimized());
725 }
726
727 bool VM_GetOrSetLocal::doit_prologue() {
728 _jvf = get_java_vframe();
729 NULL_CHECK(_jvf, false);
730
731 if (_jvf->method()->is_native()) {
732 if (getting_receiver() && !_jvf->method()->is_static()) {
733 return true;
734 } else {
735 _result = JVMTI_ERROR_OPAQUE_FRAME;
736 return false;
737 }
738 }
739
740 if (!check_slot_type(_jvf)) {
741 return false;
742 }
743 return true;
744 }
745
746 void VM_GetOrSetLocal::doit() {
747 if (_set) {
748 // Force deoptimization of frame if compiled because it's
749 // possible the compiler emitted some locals as constant values,
750 // meaning they are not mutable.
751 if (can_be_deoptimized(_jvf)) {
752
753 // Schedule deoptimization so that eventually the local
754 // update will be written to an interpreter frame.
755 Deoptimization::deoptimize_frame(_jvf->thread(), _jvf->fr().id());
756
757 // Now store a new value for the local which will be applied
758 // once deoptimization occurs. Note however that while this
759 // write is deferred until deoptimization actually happens
760 // can vframe created after this point will have its locals
761 // reflecting this update so as far as anyone can see the
762 // write has already taken place.
763
764 // If we are updating an oop then get the oop from the handle
765 // since the handle will be long gone by the time the deopt
766 // happens. The oop stored in the deferred local will be
767 // gc'd on its own.
768 if (_type == T_OBJECT) {
769 _value.l = (jobject) (JNIHandles::resolve_external_guard(_value.l));
770 }
771 // Re-read the vframe so we can see that it is deoptimized
772 // [ Only need because of assert in update_local() ]
773 _jvf = get_java_vframe();
774 ((compiledVFrame*)_jvf)->update_local(_type, _index, _value);
775 return;
776 }
777 StackValueCollection *locals = _jvf->locals();
778 HandleMark hm;
779
780 switch (_type) {
781 case T_INT: locals->set_int_at (_index, _value.i); break;
782 case T_LONG: locals->set_long_at (_index, _value.j); break;
783 case T_FLOAT: locals->set_float_at (_index, _value.f); break;
784 case T_DOUBLE: locals->set_double_at(_index, _value.d); break;
785 case T_OBJECT: {
786 Handle ob_h(JNIHandles::resolve_external_guard(_value.l));
787 locals->set_obj_at (_index, ob_h);
788 break;
789 }
790 default: ShouldNotReachHere();
791 }
792 _jvf->set_locals(locals);
793 } else {
794 if (_jvf->method()->is_native() && _jvf->is_compiled_frame()) {
795 assert(getting_receiver(), "Can only get here when getting receiver");
796 oop receiver = _jvf->fr().get_native_receiver();
797 _value.l = JNIHandles::make_local(_calling_thread, receiver);
798 } else {
799 StackValueCollection *locals = _jvf->locals();
800
801 if (locals->at(_index)->type() == T_CONFLICT) {
802 memset(&_value, 0, sizeof(_value));
803 _value.l = NULL;
804 return;
805 }
806
807 switch (_type) {
808 case T_INT: _value.i = locals->int_at (_index); break;
809 case T_LONG: _value.j = locals->long_at (_index); break;
810 case T_FLOAT: _value.f = locals->float_at (_index); break;
811 case T_DOUBLE: _value.d = locals->double_at(_index); break;
812 case T_OBJECT: {
813 // Wrap the oop to be returned in a local JNI handle since
814 // oops_do() no longer applies after doit() is finished.
815 oop obj = locals->obj_at(_index)();
816 _value.l = JNIHandles::make_local(_calling_thread, obj);
817 break;
818 }
819 default: ShouldNotReachHere();
820 }
821 }
822 }
823 }
824
825
826 bool VM_GetOrSetLocal::allow_nested_vm_operations() const {
827 return true; // May need to deoptimize
828 }
829
830
831 VM_GetReceiver::VM_GetReceiver(
832 JavaThread* thread, JavaThread* caller_thread, jint depth)
833 : VM_GetOrSetLocal(thread, caller_thread, depth, 0) {}
834
835 /////////////////////////////////////////////////////////////////////////////////////////
836
837 //
838 // class JvmtiSuspendControl - see comments in jvmtiImpl.hpp
839 //
840
841 bool JvmtiSuspendControl::suspend(JavaThread *java_thread) {
842 // external suspend should have caught suspending a thread twice
843
844 // Immediate suspension required for JPDA back-end so JVMTI agent threads do
845 // not deadlock due to later suspension on transitions while holding
846 // raw monitors. Passing true causes the immediate suspension.
847 // java_suspend() will catch threads in the process of exiting
848 // and will ignore them.
849 java_thread->java_suspend();
850
851 // It would be nice to have the following assertion in all the time,
852 // but it is possible for a racing resume request to have resumed
853 // this thread right after we suspended it. Temporarily enable this
854 // assertion if you are chasing a different kind of bug.
855 //
856 // assert(java_lang_Thread::thread(java_thread->threadObj()) == NULL ||
857 // java_thread->is_being_ext_suspended(), "thread is not suspended");
858
859 if (java_lang_Thread::thread(java_thread->threadObj()) == NULL) {
860 // check again because we can get delayed in java_suspend():
861 // the thread is in process of exiting.
862 return false;
863 }
864
865 return true;
866 }
867
868 bool JvmtiSuspendControl::resume(JavaThread *java_thread) {
869 // external suspend should have caught resuming a thread twice
870 assert(java_thread->is_being_ext_suspended(), "thread should be suspended");
871
872 // resume thread
873 {
874 // must always grab Threads_lock, see JVM_SuspendThread
875 MutexLocker ml(Threads_lock);
876 java_thread->java_resume();
877 }
878
879 return true;
880 }
881
882
883 void JvmtiSuspendControl::print() {
884 #ifndef PRODUCT
885 MutexLocker mu(Threads_lock);
886 ResourceMark rm;
887
888 tty->print("Suspended Threads: [");
889 for (JavaThread *thread = Threads::first(); thread != NULL; thread = thread->next()) {
890 #ifdef JVMTI_TRACE
891 const char *name = JvmtiTrace::safe_get_thread_name(thread);
892 #else
893 const char *name = "";
894 #endif /*JVMTI_TRACE */
895 tty->print("%s(%c ", name, thread->is_being_ext_suspended() ? 'S' : '_');
896 if (!thread->has_last_Java_frame()) {
897 tty->print("no stack");
898 }
899 tty->print(") ");
900 }
901 tty->print_cr("]");
902 #endif
903 }
904
905 JvmtiDeferredEvent JvmtiDeferredEvent::compiled_method_load_event(
906 nmethod* nm) {
907 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_COMPILED_METHOD_LOAD);
908 event._event_data.compiled_method_load = nm;
909 // Keep the nmethod alive until the ServiceThread can process
910 // this deferred event.
911 nmethodLocker::lock_nmethod(nm);
912 return event;
913 }
914
915 JvmtiDeferredEvent JvmtiDeferredEvent::compiled_method_unload_event(
916 nmethod* nm, jmethodID id, const void* code) {
917 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_COMPILED_METHOD_UNLOAD);
918 event._event_data.compiled_method_unload.nm = nm;
919 event._event_data.compiled_method_unload.method_id = id;
920 event._event_data.compiled_method_unload.code_begin = code;
921 // Keep the nmethod alive until the ServiceThread can process
922 // this deferred event. This will keep the memory for the
923 // generated code from being reused too early. We pass
924 // zombie_ok == true here so that our nmethod that was just
925 // made into a zombie can be locked.
926 nmethodLocker::lock_nmethod(nm, true /* zombie_ok */);
927 return event;
928 }
929
930 JvmtiDeferredEvent JvmtiDeferredEvent::dynamic_code_generated_event(
931 const char* name, const void* code_begin, const void* code_end) {
932 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_DYNAMIC_CODE_GENERATED);
933 // Need to make a copy of the name since we don't know how long
934 // the event poster will keep it around after we enqueue the
935 // deferred event and return. strdup() failure is handled in
936 // the post() routine below.
937 event._event_data.dynamic_code_generated.name = os::strdup(name);
938 event._event_data.dynamic_code_generated.code_begin = code_begin;
939 event._event_data.dynamic_code_generated.code_end = code_end;
940 return event;
941 }
942
943 void JvmtiDeferredEvent::post() {
944 assert(ServiceThread::is_service_thread(Thread::current()),
945 "Service thread must post enqueued events");
946 switch(_type) {
947 case TYPE_COMPILED_METHOD_LOAD: {
948 nmethod* nm = _event_data.compiled_method_load;
949 JvmtiExport::post_compiled_method_load(nm);
950 // done with the deferred event so unlock the nmethod
951 nmethodLocker::unlock_nmethod(nm);
952 break;
953 }
954 case TYPE_COMPILED_METHOD_UNLOAD: {
955 nmethod* nm = _event_data.compiled_method_unload.nm;
956 JvmtiExport::post_compiled_method_unload(
957 _event_data.compiled_method_unload.method_id,
958 _event_data.compiled_method_unload.code_begin);
959 // done with the deferred event so unlock the nmethod
960 nmethodLocker::unlock_nmethod(nm);
961 break;
962 }
963 case TYPE_DYNAMIC_CODE_GENERATED: {
964 JvmtiExport::post_dynamic_code_generated_internal(
965 // if strdup failed give the event a default name
966 (_event_data.dynamic_code_generated.name == NULL)
967 ? "unknown_code" : _event_data.dynamic_code_generated.name,
968 _event_data.dynamic_code_generated.code_begin,
969 _event_data.dynamic_code_generated.code_end);
970 if (_event_data.dynamic_code_generated.name != NULL) {
971 // release our copy
972 os::free((void *)_event_data.dynamic_code_generated.name);
973 }
974 break;
975 }
976 default:
977 ShouldNotReachHere();
978 }
979 }
980
981 JvmtiDeferredEventQueue::QueueNode* JvmtiDeferredEventQueue::_queue_tail = NULL;
982 JvmtiDeferredEventQueue::QueueNode* JvmtiDeferredEventQueue::_queue_head = NULL;
983
984 volatile JvmtiDeferredEventQueue::QueueNode*
985 JvmtiDeferredEventQueue::_pending_list = NULL;
986
987 bool JvmtiDeferredEventQueue::has_events() {
988 assert(Service_lock->owned_by_self(), "Must own Service_lock");
989 return _queue_head != NULL || _pending_list != NULL;
990 }
991
992 void JvmtiDeferredEventQueue::enqueue(const JvmtiDeferredEvent& event) {
993 assert(Service_lock->owned_by_self(), "Must own Service_lock");
994
995 process_pending_events();
996
997 // Events get added to the end of the queue (and are pulled off the front).
998 QueueNode* node = new QueueNode(event);
999 if (_queue_tail == NULL) {
1000 _queue_tail = _queue_head = node;
1001 } else {
1002 assert(_queue_tail->next() == NULL, "Must be the last element in the list");
1003 _queue_tail->set_next(node);
1004 _queue_tail = node;
1005 }
1006
1007 Service_lock->notify_all();
1008 assert((_queue_head == NULL) == (_queue_tail == NULL),
1009 "Inconsistent queue markers");
1010 }
1011
1012 JvmtiDeferredEvent JvmtiDeferredEventQueue::dequeue() {
1013 assert(Service_lock->owned_by_self(), "Must own Service_lock");
1014
1015 process_pending_events();
1016
1017 assert(_queue_head != NULL, "Nothing to dequeue");
1018
1019 if (_queue_head == NULL) {
1020 // Just in case this happens in product; it shouldn't but let's not crash
1021 return JvmtiDeferredEvent();
1022 }
1023
1024 QueueNode* node = _queue_head;
1025 _queue_head = _queue_head->next();
1026 if (_queue_head == NULL) {
1027 _queue_tail = NULL;
1028 }
1029
1030 assert((_queue_head == NULL) == (_queue_tail == NULL),
1031 "Inconsistent queue markers");
1032
1033 JvmtiDeferredEvent event = node->event();
1034 delete node;
1035 return event;
1036 }
1037
1038 void JvmtiDeferredEventQueue::add_pending_event(
1039 const JvmtiDeferredEvent& event) {
1040
1041 QueueNode* node = new QueueNode(event);
1042
1043 bool success = false;
1044 QueueNode* prev_value = (QueueNode*)_pending_list;
1045 do {
1046 node->set_next(prev_value);
1047 prev_value = (QueueNode*)Atomic::cmpxchg_ptr(
1048 (void*)node, (volatile void*)&_pending_list, (void*)node->next());
1049 } while (prev_value != node->next());
1050 }
1051
1052 // This method transfers any events that were added by someone NOT holding
1053 // the lock into the mainline queue.
1054 void JvmtiDeferredEventQueue::process_pending_events() {
1055 assert(Service_lock->owned_by_self(), "Must own Service_lock");
1056
1057 if (_pending_list != NULL) {
1058 QueueNode* head =
1059 (QueueNode*)Atomic::xchg_ptr(NULL, (volatile void*)&_pending_list);
1060
1061 assert((_queue_head == NULL) == (_queue_tail == NULL),
1062 "Inconsistent queue markers");
1063
1064 if (head != NULL) {
1065 // Since we've treated the pending list as a stack (with newer
1066 // events at the beginning), we need to join the bottom of the stack
1067 // with the 'tail' of the queue in order to get the events in the
1068 // right order. We do this by reversing the pending list and appending
1069 // it to the queue.
1070
1071 QueueNode* new_tail = head;
1072 QueueNode* new_head = NULL;
1073
1074 // This reverses the list
1075 QueueNode* prev = new_tail;
1076 QueueNode* node = new_tail->next();
1077 new_tail->set_next(NULL);
1078 while (node != NULL) {
1079 QueueNode* next = node->next();
1080 node->set_next(prev);
1081 prev = node;
1082 node = next;
1083 }
1084 new_head = prev;
1085
1086 // Now append the new list to the queue
1087 if (_queue_tail != NULL) {
1088 _queue_tail->set_next(new_head);
1089 } else { // _queue_head == NULL
1090 _queue_head = new_head;
1091 }
1092 _queue_tail = new_tail;
1093 }
1094 }
1095 }