1 /*
2 * Copyright (c) 2003, 2013, 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::gc_epilogue() {
214 int len = _elements->length();
215 for (int i=0; i<len; i++) {
216 _cache[i] = _elements->at(i)->getCacheValue();
217 }
218 }
219
220 //
221 // class JvmtiBreakpoint
222 //
223
224 JvmtiBreakpoint::JvmtiBreakpoint() {
225 _method = NULL;
226 _bci = 0;
227 _class_loader = NULL;
228 #ifdef CHECK_UNHANDLED_OOPS
229 // This one is always allocated with new, but check it just in case.
230 Thread *thread = Thread::current();
231 if (thread->is_in_stack((address)&_method)) {
232 thread->allow_unhandled_oop((oop*)&_method);
233 }
234 #endif // CHECK_UNHANDLED_OOPS
235 }
236
237 JvmtiBreakpoint::JvmtiBreakpoint(Method* m_method, jlocation location) {
238 _method = m_method;
239 _class_loader = _method->method_holder()->class_loader_data()->class_loader();
240 assert(_method != NULL, "_method != NULL");
241 _bci = (int) location;
242 assert(_bci >= 0, "_bci >= 0");
243 }
244
245 void JvmtiBreakpoint::copy(JvmtiBreakpoint& bp) {
246 _method = bp._method;
247 _bci = bp._bci;
248 _class_loader = bp._class_loader;
249 }
250
251 bool JvmtiBreakpoint::lessThan(JvmtiBreakpoint& bp) {
252 Unimplemented();
253 return false;
254 }
255
256 bool JvmtiBreakpoint::equals(JvmtiBreakpoint& bp) {
257 return _method == bp._method
258 && _bci == bp._bci;
259 }
260
261 bool JvmtiBreakpoint::is_valid() {
262 // class loader can be NULL
263 return _method != NULL &&
264 _bci >= 0;
265 }
266
267 address JvmtiBreakpoint::getBcp() {
268 return _method->bcp_from(_bci);
269 }
270
271 void JvmtiBreakpoint::each_method_version_do(method_action meth_act) {
272 ((Method*)_method->*meth_act)(_bci);
273
274 // add/remove breakpoint to/from versions of the method that
275 // are EMCP. Directly or transitively obsolete methods are
276 // not saved in the PreviousVersionNodes.
277 Thread *thread = Thread::current();
278 instanceKlassHandle ikh = instanceKlassHandle(thread, _method->method_holder());
279 Symbol* m_name = _method->name();
280 Symbol* m_signature = _method->signature();
281
282 // search previous versions if they exist
283 PreviousVersionWalker pvw(thread, (InstanceKlass *)ikh());
284 for (PreviousVersionNode * pv_node = pvw.next_previous_version();
285 pv_node != NULL; pv_node = pvw.next_previous_version()) {
286 GrowableArray<Method*>* methods = pv_node->prev_EMCP_methods();
287
288 if (methods == NULL) {
289 // We have run into a PreviousVersion generation where
290 // all methods were made obsolete during that generation's
291 // RedefineClasses() operation. At the time of that
292 // operation, all EMCP methods were flushed so we don't
293 // have to go back any further.
294 //
295 // A NULL methods array is different than an empty methods
296 // array. We cannot infer any optimizations about older
297 // generations from an empty methods array for the current
298 // generation.
299 break;
300 }
301
302 for (int i = methods->length() - 1; i >= 0; i--) {
303 Method* method = methods->at(i);
304 // obsolete methods that are running are not deleted from
305 // previous version array, but they are skipped here.
306 if (!method->is_obsolete() &&
307 method->name() == m_name &&
308 method->signature() == m_signature) {
309 RC_TRACE(0x00000800, ("%sing breakpoint in %s(%s)",
310 meth_act == &Method::set_breakpoint ? "sett" : "clear",
311 method->name()->as_C_string(),
312 method->signature()->as_C_string()));
313
314 (method->*meth_act)(_bci);
315 break;
316 }
317 }
318 }
319 }
320
321 void JvmtiBreakpoint::set() {
322 each_method_version_do(&Method::set_breakpoint);
323 }
324
325 void JvmtiBreakpoint::clear() {
326 each_method_version_do(&Method::clear_breakpoint);
327 }
328
329 void JvmtiBreakpoint::print() {
330 #ifndef PRODUCT
331 const char *class_name = (_method == NULL) ? "NULL" : _method->klass_name()->as_C_string();
332 const char *method_name = (_method == NULL) ? "NULL" : _method->name()->as_C_string();
333
334 tty->print("Breakpoint(%s,%s,%d,%p)",class_name, method_name, _bci, getBcp());
335 #endif
336 }
337
338
339 //
340 // class VM_ChangeBreakpoints
341 //
342 // Modify the Breakpoints data structure at a safepoint
343 //
344
345 void VM_ChangeBreakpoints::doit() {
346 switch (_operation) {
347 case SET_BREAKPOINT:
348 _breakpoints->set_at_safepoint(*_bp);
349 break;
350 case CLEAR_BREAKPOINT:
351 _breakpoints->clear_at_safepoint(*_bp);
352 break;
353 default:
354 assert(false, "Unknown operation");
355 }
356 }
357
358 void VM_ChangeBreakpoints::oops_do(OopClosure* f) {
359 // The JvmtiBreakpoints in _breakpoints will be visited via
360 // JvmtiExport::oops_do.
361 if (_bp != NULL) {
362 _bp->oops_do(f);
363 }
364 }
365
366 //
367 // class JvmtiBreakpoints
368 //
369 // a JVMTI internal collection of JvmtiBreakpoint
370 //
371
372 JvmtiBreakpoints::JvmtiBreakpoints(void listener_fun(void *,address *)) {
373 _bps.initialize(this,listener_fun);
374 }
375
376 JvmtiBreakpoints:: ~JvmtiBreakpoints() {}
377
378 void JvmtiBreakpoints::oops_do(OopClosure* f) {
379 _bps.oops_do(f);
380 }
381
382 void JvmtiBreakpoints::gc_epilogue() {
383 _bps.gc_epilogue();
384 }
385
386 void JvmtiBreakpoints::print() {
387 #ifndef PRODUCT
388 ResourceMark rm;
389
390 int n = _bps.length();
391 for (int i=0; i<n; i++) {
392 JvmtiBreakpoint& bp = _bps.at(i);
393 tty->print("%d: ", i);
394 bp.print();
395 tty->print_cr("");
396 }
397 #endif
398 }
399
400
401 void JvmtiBreakpoints::set_at_safepoint(JvmtiBreakpoint& bp) {
402 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
403
404 int i = _bps.find(bp);
405 if (i == -1) {
406 _bps.append(bp);
407 bp.set();
408 }
409 }
410
411 void JvmtiBreakpoints::clear_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.remove(i);
417 bp.clear();
418 }
419 }
420
421 int JvmtiBreakpoints::length() { return _bps.length(); }
422
423 int JvmtiBreakpoints::set(JvmtiBreakpoint& bp) {
424 if ( _bps.find(bp) != -1) {
425 return JVMTI_ERROR_DUPLICATE;
426 }
427 VM_ChangeBreakpoints set_breakpoint(VM_ChangeBreakpoints::SET_BREAKPOINT, &bp);
428 VMThread::execute(&set_breakpoint);
429 return JVMTI_ERROR_NONE;
430 }
431
432 int JvmtiBreakpoints::clear(JvmtiBreakpoint& bp) {
433 if ( _bps.find(bp) == -1) {
434 return JVMTI_ERROR_NOT_FOUND;
435 }
436
437 VM_ChangeBreakpoints clear_breakpoint(VM_ChangeBreakpoints::CLEAR_BREAKPOINT, &bp);
438 VMThread::execute(&clear_breakpoint);
439 return JVMTI_ERROR_NONE;
440 }
441
442 void JvmtiBreakpoints::clearall_in_class_at_safepoint(Klass* klass) {
443 bool changed = true;
444 // We are going to run thru the list of bkpts
445 // and delete some. This deletion probably alters
446 // the list in some implementation defined way such
447 // that when we delete entry i, the next entry might
448 // no longer be at i+1. To be safe, each time we delete
449 // an entry, we'll just start again from the beginning.
450 // We'll stop when we make a pass thru the whole list without
451 // deleting anything.
452 while (changed) {
453 int len = _bps.length();
454 changed = false;
455 for (int i = 0; i < len; i++) {
456 JvmtiBreakpoint& bp = _bps.at(i);
457 if (bp.method()->method_holder() == klass) {
458 bp.clear();
459 _bps.remove(i);
460 // This changed 'i' so we have to start over.
461 changed = true;
462 break;
463 }
464 }
465 }
466 }
467
468 //
469 // class JvmtiCurrentBreakpoints
470 //
471
472 JvmtiBreakpoints *JvmtiCurrentBreakpoints::_jvmti_breakpoints = NULL;
473 address * JvmtiCurrentBreakpoints::_breakpoint_list = NULL;
474
475
476 JvmtiBreakpoints& JvmtiCurrentBreakpoints::get_jvmti_breakpoints() {
477 if (_jvmti_breakpoints != NULL) return (*_jvmti_breakpoints);
478 _jvmti_breakpoints = new JvmtiBreakpoints(listener_fun);
479 assert(_jvmti_breakpoints != NULL, "_jvmti_breakpoints != NULL");
480 return (*_jvmti_breakpoints);
481 }
482
483 void JvmtiCurrentBreakpoints::listener_fun(void *this_obj, address *cache) {
484 JvmtiBreakpoints *this_jvmti = (JvmtiBreakpoints *) this_obj;
485 assert(this_jvmti != NULL, "this_jvmti != NULL");
486
487 debug_only(int n = this_jvmti->length(););
488 assert(cache[n] == NULL, "cache must be NULL terminated");
489
490 set_breakpoint_list(cache);
491 }
492
493
494 void JvmtiCurrentBreakpoints::oops_do(OopClosure* f) {
495 if (_jvmti_breakpoints != NULL) {
496 _jvmti_breakpoints->oops_do(f);
497 }
498 }
499
500 void JvmtiCurrentBreakpoints::gc_epilogue() {
501 if (_jvmti_breakpoints != NULL) {
502 _jvmti_breakpoints->gc_epilogue();
503 }
504 }
505
506 ///////////////////////////////////////////////////////////////
507 //
508 // class VM_GetOrSetLocal
509 //
510
511 // Constructor for non-object getter
512 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, jint depth, int index, BasicType type)
513 : _thread(thread)
514 , _calling_thread(NULL)
515 , _depth(depth)
516 , _index(index)
517 , _type(type)
518 , _set(false)
519 , _jvf(NULL)
520 , _result(JVMTI_ERROR_NONE)
521 {
522 }
523
524 // Constructor for object or non-object setter
525 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, jint depth, int index, BasicType type, jvalue value)
526 : _thread(thread)
527 , _calling_thread(NULL)
528 , _depth(depth)
529 , _index(index)
530 , _type(type)
531 , _value(value)
532 , _set(true)
533 , _jvf(NULL)
534 , _result(JVMTI_ERROR_NONE)
535 {
536 }
537
538 // Constructor for object getter
539 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, JavaThread* calling_thread, jint depth, int index)
540 : _thread(thread)
541 , _calling_thread(calling_thread)
542 , _depth(depth)
543 , _index(index)
544 , _type(T_OBJECT)
545 , _set(false)
546 , _jvf(NULL)
547 , _result(JVMTI_ERROR_NONE)
548 {
549 }
550
551 vframe *VM_GetOrSetLocal::get_vframe() {
552 if (!_thread->has_last_Java_frame()) {
553 return NULL;
554 }
555 RegisterMap reg_map(_thread);
556 vframe *vf = _thread->last_java_vframe(®_map);
557 int d = 0;
558 while ((vf != NULL) && (d < _depth)) {
559 vf = vf->java_sender();
560 d++;
561 }
562 return vf;
563 }
564
565 javaVFrame *VM_GetOrSetLocal::get_java_vframe() {
566 vframe* vf = get_vframe();
567 if (vf == NULL) {
568 _result = JVMTI_ERROR_NO_MORE_FRAMES;
569 return NULL;
570 }
571 javaVFrame *jvf = (javaVFrame*)vf;
572
573 if (!vf->is_java_frame()) {
574 _result = JVMTI_ERROR_OPAQUE_FRAME;
575 return NULL;
576 }
577 return jvf;
578 }
579
580 // Check that the klass is assignable to a type with the given signature.
581 // Another solution could be to use the function Klass::is_subtype_of(type).
582 // But the type class can be forced to load/initialize eagerly in such a case.
583 // This may cause unexpected consequences like CFLH or class-init JVMTI events.
584 // It is better to avoid such a behavior.
585 bool VM_GetOrSetLocal::is_assignable(const char* ty_sign, Klass* klass, Thread* thread) {
586 assert(ty_sign != NULL, "type signature must not be NULL");
587 assert(thread != NULL, "thread must not be NULL");
588 assert(klass != NULL, "klass must not be NULL");
589
590 int len = (int) strlen(ty_sign);
591 if (ty_sign[0] == 'L' && ty_sign[len-1] == ';') { // Need pure class/interface name
592 ty_sign++;
593 len -= 2;
594 }
595 TempNewSymbol ty_sym = SymbolTable::new_symbol(ty_sign, len, thread);
596 if (klass->name() == ty_sym) {
597 return true;
598 }
599 // Compare primary supers
600 int super_depth = klass->super_depth();
601 int idx;
602 for (idx = 0; idx < super_depth; idx++) {
603 if (klass->primary_super_of_depth(idx)->name() == ty_sym) {
604 return true;
605 }
606 }
607 // Compare secondary supers
608 Array<Klass*>* sec_supers = klass->secondary_supers();
609 for (idx = 0; idx < sec_supers->length(); idx++) {
610 if (((Klass*) sec_supers->at(idx))->name() == ty_sym) {
611 return true;
612 }
613 }
614 return false;
615 }
616
617 // Checks error conditions:
618 // JVMTI_ERROR_INVALID_SLOT
619 // JVMTI_ERROR_TYPE_MISMATCH
620 // Returns: 'true' - everything is Ok, 'false' - error code
621
622 bool VM_GetOrSetLocal::check_slot_type(javaVFrame* jvf) {
623 Method* method_oop = jvf->method();
624 if (!method_oop->has_localvariable_table()) {
625 // Just to check index boundaries
626 jint extra_slot = (_type == T_LONG || _type == T_DOUBLE) ? 1 : 0;
627 if (_index < 0 || _index + extra_slot >= method_oop->max_locals()) {
628 _result = JVMTI_ERROR_INVALID_SLOT;
629 return false;
630 }
631 return true;
632 }
633
634 jint num_entries = method_oop->localvariable_table_length();
635 if (num_entries == 0) {
636 _result = JVMTI_ERROR_INVALID_SLOT;
637 return false; // There are no slots
638 }
639 int signature_idx = -1;
640 int vf_bci = jvf->bci();
641 LocalVariableTableElement* table = method_oop->localvariable_table_start();
642 for (int i = 0; i < num_entries; i++) {
643 int start_bci = table[i].start_bci;
644 int end_bci = start_bci + table[i].length;
645
646 // Here we assume that locations of LVT entries
647 // with the same slot number cannot be overlapped
648 if (_index == (jint) table[i].slot && start_bci <= vf_bci && vf_bci <= end_bci) {
649 signature_idx = (int) table[i].descriptor_cp_index;
650 break;
651 }
652 }
653 if (signature_idx == -1) {
654 _result = JVMTI_ERROR_INVALID_SLOT;
655 return false; // Incorrect slot index
656 }
657 Symbol* sign_sym = method_oop->constants()->symbol_at(signature_idx);
658 const char* signature = (const char *) sign_sym->as_utf8();
659 BasicType slot_type = char2type(signature[0]);
660
661 switch (slot_type) {
662 case T_BYTE:
663 case T_SHORT:
664 case T_CHAR:
665 case T_BOOLEAN:
666 slot_type = T_INT;
667 break;
668 case T_ARRAY:
669 slot_type = T_OBJECT;
670 break;
671 };
672 if (_type != slot_type) {
673 _result = JVMTI_ERROR_TYPE_MISMATCH;
674 return false;
675 }
676
677 jobject jobj = _value.l;
678 if (_set && slot_type == T_OBJECT && jobj != NULL) { // NULL reference is allowed
679 // Check that the jobject class matches the return type signature.
680 JavaThread* cur_thread = JavaThread::current();
681 HandleMark hm(cur_thread);
682
683 Handle obj = Handle(cur_thread, JNIHandles::resolve_external_guard(jobj));
684 NULL_CHECK(obj, (_result = JVMTI_ERROR_INVALID_OBJECT, false));
685 KlassHandle ob_kh = KlassHandle(cur_thread, obj->klass());
686 NULL_CHECK(ob_kh, (_result = JVMTI_ERROR_INVALID_OBJECT, false));
687
688 if (!is_assignable(signature, ob_kh(), cur_thread)) {
689 _result = JVMTI_ERROR_TYPE_MISMATCH;
690 return false;
691 }
692 }
693 return true;
694 }
695
696 static bool can_be_deoptimized(vframe* vf) {
697 return (vf->is_compiled_frame() && vf->fr().can_be_deoptimized());
698 }
699
700 bool VM_GetOrSetLocal::doit_prologue() {
701 _jvf = get_java_vframe();
702 NULL_CHECK(_jvf, false);
703
704 if (_jvf->method()->is_native()) {
705 if (getting_receiver() && !_jvf->method()->is_static()) {
706 return true;
707 } else {
708 _result = JVMTI_ERROR_OPAQUE_FRAME;
709 return false;
710 }
711 }
712
713 if (!check_slot_type(_jvf)) {
714 return false;
715 }
716 return true;
717 }
718
719 void VM_GetOrSetLocal::doit() {
720 if (_set) {
721 // Force deoptimization of frame if compiled because it's
722 // possible the compiler emitted some locals as constant values,
723 // meaning they are not mutable.
724 if (can_be_deoptimized(_jvf)) {
725
726 // Schedule deoptimization so that eventually the local
727 // update will be written to an interpreter frame.
728 Deoptimization::deoptimize_frame(_jvf->thread(), _jvf->fr().id());
729
730 // Now store a new value for the local which will be applied
731 // once deoptimization occurs. Note however that while this
732 // write is deferred until deoptimization actually happens
733 // can vframe created after this point will have its locals
734 // reflecting this update so as far as anyone can see the
735 // write has already taken place.
736
737 // If we are updating an oop then get the oop from the handle
738 // since the handle will be long gone by the time the deopt
739 // happens. The oop stored in the deferred local will be
740 // gc'd on its own.
741 if (_type == T_OBJECT) {
742 _value.l = (jobject) (JNIHandles::resolve_external_guard(_value.l));
743 }
744 // Re-read the vframe so we can see that it is deoptimized
745 // [ Only need because of assert in update_local() ]
746 _jvf = get_java_vframe();
747 ((compiledVFrame*)_jvf)->update_local(_type, _index, _value);
748 return;
749 }
750 StackValueCollection *locals = _jvf->locals();
751 HandleMark hm;
752
753 switch (_type) {
754 case T_INT: locals->set_int_at (_index, _value.i); break;
755 case T_LONG: locals->set_long_at (_index, _value.j); break;
756 case T_FLOAT: locals->set_float_at (_index, _value.f); break;
757 case T_DOUBLE: locals->set_double_at(_index, _value.d); break;
758 case T_OBJECT: {
759 Handle ob_h(JNIHandles::resolve_external_guard(_value.l));
760 locals->set_obj_at (_index, ob_h);
761 break;
762 }
763 default: ShouldNotReachHere();
764 }
765 _jvf->set_locals(locals);
766 } else {
767 if (_jvf->method()->is_native() && _jvf->is_compiled_frame()) {
768 assert(getting_receiver(), "Can only get here when getting receiver");
769 oop receiver = _jvf->fr().get_native_receiver();
770 _value.l = JNIHandles::make_local(_calling_thread, receiver);
771 } else {
772 StackValueCollection *locals = _jvf->locals();
773
774 if (locals->at(_index)->type() == T_CONFLICT) {
775 memset(&_value, 0, sizeof(_value));
776 _value.l = NULL;
777 return;
778 }
779
780 switch (_type) {
781 case T_INT: _value.i = locals->int_at (_index); break;
782 case T_LONG: _value.j = locals->long_at (_index); break;
783 case T_FLOAT: _value.f = locals->float_at (_index); break;
784 case T_DOUBLE: _value.d = locals->double_at(_index); break;
785 case T_OBJECT: {
786 // Wrap the oop to be returned in a local JNI handle since
787 // oops_do() no longer applies after doit() is finished.
788 oop obj = locals->obj_at(_index)();
789 _value.l = JNIHandles::make_local(_calling_thread, obj);
790 break;
791 }
792 default: ShouldNotReachHere();
793 }
794 }
795 }
796 }
797
798
799 bool VM_GetOrSetLocal::allow_nested_vm_operations() const {
800 return true; // May need to deoptimize
801 }
802
803
804 VM_GetReceiver::VM_GetReceiver(
805 JavaThread* thread, JavaThread* caller_thread, jint depth)
806 : VM_GetOrSetLocal(thread, caller_thread, depth, 0) {}
807
808 /////////////////////////////////////////////////////////////////////////////////////////
809
810 //
811 // class JvmtiSuspendControl - see comments in jvmtiImpl.hpp
812 //
813
814 bool JvmtiSuspendControl::suspend(JavaThread *java_thread) {
815 // external suspend should have caught suspending a thread twice
816
817 // Immediate suspension required for JPDA back-end so JVMTI agent threads do
818 // not deadlock due to later suspension on transitions while holding
819 // raw monitors. Passing true causes the immediate suspension.
820 // java_suspend() will catch threads in the process of exiting
821 // and will ignore them.
822 java_thread->java_suspend();
823
824 // It would be nice to have the following assertion in all the time,
825 // but it is possible for a racing resume request to have resumed
826 // this thread right after we suspended it. Temporarily enable this
827 // assertion if you are chasing a different kind of bug.
828 //
829 // assert(java_lang_Thread::thread(java_thread->threadObj()) == NULL ||
830 // java_thread->is_being_ext_suspended(), "thread is not suspended");
831
832 if (java_lang_Thread::thread(java_thread->threadObj()) == NULL) {
833 // check again because we can get delayed in java_suspend():
834 // the thread is in process of exiting.
835 return false;
836 }
837
838 return true;
839 }
840
841 bool JvmtiSuspendControl::resume(JavaThread *java_thread) {
842 // external suspend should have caught resuming a thread twice
843 assert(java_thread->is_being_ext_suspended(), "thread should be suspended");
844
845 // resume thread
846 {
847 // must always grab Threads_lock, see JVM_SuspendThread
848 MutexLocker ml(Threads_lock);
849 java_thread->java_resume();
850 }
851
852 return true;
853 }
854
855
856 void JvmtiSuspendControl::print() {
857 #ifndef PRODUCT
858 MutexLocker mu(Threads_lock);
859 ResourceMark rm;
860
861 tty->print("Suspended Threads: [");
862 for (JavaThread *thread = Threads::first(); thread != NULL; thread = thread->next()) {
863 #ifdef JVMTI_TRACE
864 const char *name = JvmtiTrace::safe_get_thread_name(thread);
865 #else
866 const char *name = "";
867 #endif /*JVMTI_TRACE */
868 tty->print("%s(%c ", name, thread->is_being_ext_suspended() ? 'S' : '_');
869 if (!thread->has_last_Java_frame()) {
870 tty->print("no stack");
871 }
872 tty->print(") ");
873 }
874 tty->print_cr("]");
875 #endif
876 }
877
878 JvmtiDeferredEvent JvmtiDeferredEvent::compiled_method_load_event(
879 nmethod* nm) {
880 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_COMPILED_METHOD_LOAD);
881 event._event_data.compiled_method_load = nm;
882 // Keep the nmethod alive until the ServiceThread can process
883 // this deferred event.
884 nmethodLocker::lock_nmethod(nm);
885 return event;
886 }
887
888 JvmtiDeferredEvent JvmtiDeferredEvent::compiled_method_unload_event(
889 nmethod* nm, jmethodID id, const void* code) {
890 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_COMPILED_METHOD_UNLOAD);
891 event._event_data.compiled_method_unload.nm = nm;
892 event._event_data.compiled_method_unload.method_id = id;
893 event._event_data.compiled_method_unload.code_begin = code;
894 // Keep the nmethod alive until the ServiceThread can process
895 // this deferred event. This will keep the memory for the
896 // generated code from being reused too early. We pass
897 // zombie_ok == true here so that our nmethod that was just
898 // made into a zombie can be locked.
899 nmethodLocker::lock_nmethod(nm, true /* zombie_ok */);
900 return event;
901 }
902
903 JvmtiDeferredEvent JvmtiDeferredEvent::dynamic_code_generated_event(
904 const char* name, const void* code_begin, const void* code_end) {
905 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_DYNAMIC_CODE_GENERATED);
906 // Need to make a copy of the name since we don't know how long
907 // the event poster will keep it around after we enqueue the
908 // deferred event and return. strdup() failure is handled in
909 // the post() routine below.
910 event._event_data.dynamic_code_generated.name = os::strdup(name);
911 event._event_data.dynamic_code_generated.code_begin = code_begin;
912 event._event_data.dynamic_code_generated.code_end = code_end;
913 return event;
914 }
915
916 void JvmtiDeferredEvent::post() {
917 assert(ServiceThread::is_service_thread(Thread::current()),
918 "Service thread must post enqueued events");
919 switch(_type) {
920 case TYPE_COMPILED_METHOD_LOAD: {
921 nmethod* nm = _event_data.compiled_method_load;
922 JvmtiExport::post_compiled_method_load(nm);
923 // done with the deferred event so unlock the nmethod
924 nmethodLocker::unlock_nmethod(nm);
925 break;
926 }
927 case TYPE_COMPILED_METHOD_UNLOAD: {
928 nmethod* nm = _event_data.compiled_method_unload.nm;
929 JvmtiExport::post_compiled_method_unload(
930 _event_data.compiled_method_unload.method_id,
931 _event_data.compiled_method_unload.code_begin);
932 // done with the deferred event so unlock the nmethod
933 nmethodLocker::unlock_nmethod(nm);
934 break;
935 }
936 case TYPE_DYNAMIC_CODE_GENERATED: {
937 JvmtiExport::post_dynamic_code_generated_internal(
938 // if strdup failed give the event a default name
939 (_event_data.dynamic_code_generated.name == NULL)
940 ? "unknown_code" : _event_data.dynamic_code_generated.name,
941 _event_data.dynamic_code_generated.code_begin,
942 _event_data.dynamic_code_generated.code_end);
943 if (_event_data.dynamic_code_generated.name != NULL) {
944 // release our copy
945 os::free((void *)_event_data.dynamic_code_generated.name);
946 }
947 break;
948 }
949 default:
950 ShouldNotReachHere();
951 }
952 }
953
954 JvmtiDeferredEventQueue::QueueNode* JvmtiDeferredEventQueue::_queue_tail = NULL;
955 JvmtiDeferredEventQueue::QueueNode* JvmtiDeferredEventQueue::_queue_head = NULL;
956
957 volatile JvmtiDeferredEventQueue::QueueNode*
958 JvmtiDeferredEventQueue::_pending_list = NULL;
959
960 bool JvmtiDeferredEventQueue::has_events() {
961 assert(Service_lock->owned_by_self(), "Must own Service_lock");
962 return _queue_head != NULL || _pending_list != NULL;
963 }
964
965 void JvmtiDeferredEventQueue::enqueue(const JvmtiDeferredEvent& event) {
966 assert(Service_lock->owned_by_self(), "Must own Service_lock");
967
968 process_pending_events();
969
970 // Events get added to the end of the queue (and are pulled off the front).
971 QueueNode* node = new QueueNode(event);
972 if (_queue_tail == NULL) {
973 _queue_tail = _queue_head = node;
974 } else {
975 assert(_queue_tail->next() == NULL, "Must be the last element in the list");
976 _queue_tail->set_next(node);
977 _queue_tail = node;
978 }
979
980 Service_lock->notify_all();
981 assert((_queue_head == NULL) == (_queue_tail == NULL),
982 "Inconsistent queue markers");
983 }
984
985 JvmtiDeferredEvent JvmtiDeferredEventQueue::dequeue() {
986 assert(Service_lock->owned_by_self(), "Must own Service_lock");
987
988 process_pending_events();
989
990 assert(_queue_head != NULL, "Nothing to dequeue");
991
992 if (_queue_head == NULL) {
993 // Just in case this happens in product; it shouldn't but let's not crash
994 return JvmtiDeferredEvent();
995 }
996
997 QueueNode* node = _queue_head;
998 _queue_head = _queue_head->next();
999 if (_queue_head == NULL) {
1000 _queue_tail = NULL;
1001 }
1002
1003 assert((_queue_head == NULL) == (_queue_tail == NULL),
1004 "Inconsistent queue markers");
1005
1006 JvmtiDeferredEvent event = node->event();
1007 delete node;
1008 return event;
1009 }
1010
1011 void JvmtiDeferredEventQueue::add_pending_event(
1012 const JvmtiDeferredEvent& event) {
1013
1014 QueueNode* node = new QueueNode(event);
1015
1016 bool success = false;
1017 QueueNode* prev_value = (QueueNode*)_pending_list;
1018 do {
1019 node->set_next(prev_value);
1020 prev_value = (QueueNode*)Atomic::cmpxchg_ptr(
1021 (void*)node, (volatile void*)&_pending_list, (void*)node->next());
1022 } while (prev_value != node->next());
1023 }
1024
1025 // This method transfers any events that were added by someone NOT holding
1026 // the lock into the mainline queue.
1027 void JvmtiDeferredEventQueue::process_pending_events() {
1028 assert(Service_lock->owned_by_self(), "Must own Service_lock");
1029
1030 if (_pending_list != NULL) {
1031 QueueNode* head =
1032 (QueueNode*)Atomic::xchg_ptr(NULL, (volatile void*)&_pending_list);
1033
1034 assert((_queue_head == NULL) == (_queue_tail == NULL),
1035 "Inconsistent queue markers");
1036
1037 if (head != NULL) {
1038 // Since we've treated the pending list as a stack (with newer
1039 // events at the beginning), we need to join the bottom of the stack
1040 // with the 'tail' of the queue in order to get the events in the
1041 // right order. We do this by reversing the pending list and appending
1042 // it to the queue.
1043
1044 QueueNode* new_tail = head;
1045 QueueNode* new_head = NULL;
1046
1047 // This reverses the list
1048 QueueNode* prev = new_tail;
1049 QueueNode* node = new_tail->next();
1050 new_tail->set_next(NULL);
1051 while (node != NULL) {
1052 QueueNode* next = node->next();
1053 node->set_next(prev);
1054 prev = node;
1055 node = next;
1056 }
1057 new_head = prev;
1058
1059 // Now append the new list to the queue
1060 if (_queue_tail != NULL) {
1061 _queue_tail->set_next(new_head);
1062 } else { // _queue_head == NULL
1063 _queue_head = new_head;
1064 }
1065 _queue_tail = new_tail;
1066 }
1067 }
1068 }