1 /*
2 * Copyright (c) 2003, 2019, 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/symbolTable.hpp"
27 #include "classfile/systemDictionary.hpp"
28 #include "code/nmethod.hpp"
29 #include "gc/shared/oopStorage.hpp"
30 #include "gc/shared/oopStorageSet.hpp"
31 #include "interpreter/interpreter.hpp"
32 #include "interpreter/oopMapCache.hpp"
33 #include "jvmtifiles/jvmtiEnv.hpp"
34 #include "logging/log.hpp"
35 #include "logging/logStream.hpp"
36 #include "memory/allocation.inline.hpp"
37 #include "memory/resourceArea.hpp"
38 #include "oops/instanceKlass.hpp"
39 #include "oops/oop.inline.hpp"
40 #include "prims/jvmtiAgentThread.hpp"
41 #include "prims/jvmtiEventController.inline.hpp"
42 #include "prims/jvmtiImpl.hpp"
43 #include "prims/jvmtiRedefineClasses.hpp"
44 #include "runtime/deoptimization.hpp"
45 #include "runtime/frame.inline.hpp"
46 #include "runtime/handles.inline.hpp"
47 #include "runtime/interfaceSupport.inline.hpp"
48 #include "runtime/javaCalls.hpp"
49 #include "runtime/os.hpp"
50 #include "runtime/serviceThread.hpp"
51 #include "runtime/signature.hpp"
52 #include "runtime/thread.inline.hpp"
53 #include "runtime/threadSMR.hpp"
54 #include "runtime/vframe.hpp"
55 #include "runtime/vframe_hp.hpp"
56 #include "runtime/vmOperations.hpp"
57 #include "utilities/exceptions.hpp"
58
59 //
60 // class JvmtiAgentThread
61 //
62 // JavaThread used to wrap a thread started by an agent
63 // using the JVMTI method RunAgentThread.
64 //
65
66 JvmtiAgentThread::JvmtiAgentThread(JvmtiEnv* env, jvmtiStartFunction start_fn, const void *start_arg)
67 : JavaThread(start_function_wrapper) {
68 _env = env;
69 _start_fn = start_fn;
70 _start_arg = start_arg;
71 }
72
73 void
74 JvmtiAgentThread::start_function_wrapper(JavaThread *thread, TRAPS) {
75 // It is expected that any Agent threads will be created as
76 // Java Threads. If this is the case, notification of the creation
77 // of the thread is given in JavaThread::thread_main().
78 assert(thread->is_Java_thread(), "debugger thread should be a Java Thread");
79 assert(thread == JavaThread::current(), "sanity check");
80
81 JvmtiAgentThread *dthread = (JvmtiAgentThread *)thread;
82 dthread->call_start_function();
83 }
84
85 void
86 JvmtiAgentThread::call_start_function() {
87 ThreadToNativeFromVM transition(this);
88 _start_fn(_env->jvmti_external(), jni_environment(), (void*)_start_arg);
89 }
90
91
92 //
93 // class GrowableCache - private methods
94 //
95
96 void GrowableCache::recache() {
97 int len = _elements->length();
98
99 FREE_C_HEAP_ARRAY(address, _cache);
100 _cache = NEW_C_HEAP_ARRAY(address,len+1, mtInternal);
101
102 for (int i=0; i<len; i++) {
103 _cache[i] = _elements->at(i)->getCacheValue();
104 //
105 // The cache entry has gone bad. Without a valid frame pointer
106 // value, the entry is useless so we simply delete it in product
107 // mode. The call to remove() will rebuild the cache again
108 // without the bad entry.
109 //
110 if (_cache[i] == NULL) {
111 assert(false, "cannot recache NULL elements");
112 remove(i);
113 return;
114 }
115 }
116 _cache[len] = NULL;
117
118 _listener_fun(_this_obj,_cache);
119 }
120
121 bool GrowableCache::equals(void* v, GrowableElement *e2) {
122 GrowableElement *e1 = (GrowableElement *) v;
123 assert(e1 != NULL, "e1 != NULL");
124 assert(e2 != NULL, "e2 != NULL");
125
126 return e1->equals(e2);
127 }
128
129 //
130 // class GrowableCache - public methods
131 //
132
133 GrowableCache::GrowableCache() {
134 _this_obj = NULL;
135 _listener_fun = NULL;
136 _elements = NULL;
137 _cache = NULL;
138 }
139
140 GrowableCache::~GrowableCache() {
141 clear();
142 delete _elements;
143 FREE_C_HEAP_ARRAY(address, _cache);
144 }
145
146 void GrowableCache::initialize(void *this_obj, void listener_fun(void *, address*) ) {
147 _this_obj = this_obj;
148 _listener_fun = listener_fun;
149 _elements = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<GrowableElement*>(5,true);
150 recache();
151 }
152
153 // number of elements in the collection
154 int GrowableCache::length() {
155 return _elements->length();
156 }
157
158 // get the value of the index element in the collection
159 GrowableElement* GrowableCache::at(int index) {
160 GrowableElement *e = (GrowableElement *) _elements->at(index);
161 assert(e != NULL, "e != NULL");
162 return e;
163 }
164
165 int GrowableCache::find(GrowableElement* e) {
166 return _elements->find(e, GrowableCache::equals);
167 }
168
169 // append a copy of the element to the end of the collection
170 void GrowableCache::append(GrowableElement* e) {
171 GrowableElement *new_e = e->clone();
172 _elements->append(new_e);
173 recache();
174 }
175
176 // remove the element at index
177 void GrowableCache::remove (int index) {
178 GrowableElement *e = _elements->at(index);
179 assert(e != NULL, "e != NULL");
180 _elements->remove(e);
181 delete e;
182 recache();
183 }
184
185 // clear out all elements, release all heap space and
186 // let our listener know that things have changed.
187 void GrowableCache::clear() {
188 int len = _elements->length();
189 for (int i=0; i<len; i++) {
190 delete _elements->at(i);
191 }
192 _elements->clear();
193 recache();
194 }
195
196 //
197 // class JvmtiBreakpoint
198 //
199
200 JvmtiBreakpoint::JvmtiBreakpoint(Method* m_method, jlocation location)
201 : _method(m_method), _bci((int)location), _class_holder(NULL) {
202 assert(_method != NULL, "No method for breakpoint.");
203 assert(_bci >= 0, "Negative bci for breakpoint.");
204 oop class_holder_oop = _method->method_holder()->klass_holder();
205 _class_holder = OopStorageSet::vm_global()->allocate();
206 if (_class_holder == NULL) {
207 vm_exit_out_of_memory(sizeof(oop), OOM_MALLOC_ERROR,
208 "Cannot create breakpoint oop handle");
209 }
210 NativeAccess<>::oop_store(_class_holder, class_holder_oop);
211 }
212
213 JvmtiBreakpoint::~JvmtiBreakpoint() {
214 if (_class_holder != NULL) {
215 NativeAccess<>::oop_store(_class_holder, (oop)NULL);
216 OopStorageSet::vm_global()->release(_class_holder);
217 }
218 }
219
220 void JvmtiBreakpoint::copy(JvmtiBreakpoint& bp) {
221 _method = bp._method;
222 _bci = bp._bci;
223 _class_holder = OopStorageSet::vm_global()->allocate();
224 if (_class_holder == NULL) {
225 vm_exit_out_of_memory(sizeof(oop), OOM_MALLOC_ERROR,
226 "Cannot create breakpoint oop handle");
227 }
228 oop resolved_ch = NativeAccess<>::oop_load(bp._class_holder);
229 NativeAccess<>::oop_store(_class_holder, resolved_ch);
230 }
231
232 bool JvmtiBreakpoint::equals(JvmtiBreakpoint& bp) {
233 return _method == bp._method
234 && _bci == bp._bci;
235 }
236
237 address JvmtiBreakpoint::getBcp() const {
238 return _method->bcp_from(_bci);
239 }
240
241 void JvmtiBreakpoint::each_method_version_do(method_action meth_act) {
242 ((Method*)_method->*meth_act)(_bci);
243
244 // add/remove breakpoint to/from versions of the method that are EMCP.
245 Thread *thread = Thread::current();
246 InstanceKlass* ik = _method->method_holder();
247 Symbol* m_name = _method->name();
248 Symbol* m_signature = _method->signature();
249
250 // search previous versions if they exist
251 for (InstanceKlass* pv_node = ik->previous_versions();
252 pv_node != NULL;
253 pv_node = pv_node->previous_versions()) {
254 Array<Method*>* methods = pv_node->methods();
255
256 for (int i = methods->length() - 1; i >= 0; i--) {
257 Method* method = methods->at(i);
258 // Only set breakpoints in running EMCP methods.
259 if (method->is_running_emcp() &&
260 method->name() == m_name &&
261 method->signature() == m_signature) {
262 ResourceMark rm;
263 log_debug(redefine, class, breakpoint)
264 ("%sing breakpoint in %s(%s)", meth_act == &Method::set_breakpoint ? "sett" : "clear",
265 method->name()->as_C_string(), method->signature()->as_C_string());
266 (method->*meth_act)(_bci);
267 break;
268 }
269 }
270 }
271 }
272
273 void JvmtiBreakpoint::set() {
274 each_method_version_do(&Method::set_breakpoint);
275 }
276
277 void JvmtiBreakpoint::clear() {
278 each_method_version_do(&Method::clear_breakpoint);
279 }
280
281 void JvmtiBreakpoint::print_on(outputStream* out) const {
282 #ifndef PRODUCT
283 ResourceMark rm;
284 const char *class_name = (_method == NULL) ? "NULL" : _method->klass_name()->as_C_string();
285 const char *method_name = (_method == NULL) ? "NULL" : _method->name()->as_C_string();
286 out->print("Breakpoint(%s,%s,%d,%p)", class_name, method_name, _bci, getBcp());
287 #endif
288 }
289
290
291 //
292 // class VM_ChangeBreakpoints
293 //
294 // Modify the Breakpoints data structure at a safepoint
295 //
296
297 void VM_ChangeBreakpoints::doit() {
298 switch (_operation) {
299 case SET_BREAKPOINT:
300 _breakpoints->set_at_safepoint(*_bp);
301 break;
302 case CLEAR_BREAKPOINT:
303 _breakpoints->clear_at_safepoint(*_bp);
304 break;
305 default:
306 assert(false, "Unknown operation");
307 }
308 }
309
310 //
311 // class JvmtiBreakpoints
312 //
313 // a JVMTI internal collection of JvmtiBreakpoint
314 //
315
316 JvmtiBreakpoints::JvmtiBreakpoints(void listener_fun(void *,address *)) {
317 _bps.initialize(this,listener_fun);
318 }
319
320 JvmtiBreakpoints:: ~JvmtiBreakpoints() {}
321
322 void JvmtiBreakpoints::print() {
323 #ifndef PRODUCT
324 LogTarget(Trace, jvmti) log;
325 LogStream log_stream(log);
326
327 int n = _bps.length();
328 for (int i=0; i<n; i++) {
329 JvmtiBreakpoint& bp = _bps.at(i);
330 log_stream.print("%d: ", i);
331 bp.print_on(&log_stream);
332 log_stream.cr();
333 }
334 #endif
335 }
336
337
338 void JvmtiBreakpoints::set_at_safepoint(JvmtiBreakpoint& bp) {
339 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
340
341 int i = _bps.find(bp);
342 if (i == -1) {
343 _bps.append(bp);
344 bp.set();
345 }
346 }
347
348 void JvmtiBreakpoints::clear_at_safepoint(JvmtiBreakpoint& bp) {
349 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
350
351 int i = _bps.find(bp);
352 if (i != -1) {
353 _bps.remove(i);
354 bp.clear();
355 }
356 }
357
358 int JvmtiBreakpoints::length() { return _bps.length(); }
359
360 int JvmtiBreakpoints::set(JvmtiBreakpoint& bp) {
361 if ( _bps.find(bp) != -1) {
362 return JVMTI_ERROR_DUPLICATE;
363 }
364 VM_ChangeBreakpoints set_breakpoint(VM_ChangeBreakpoints::SET_BREAKPOINT, &bp);
365 VMThread::execute(&set_breakpoint);
366 return JVMTI_ERROR_NONE;
367 }
368
369 int JvmtiBreakpoints::clear(JvmtiBreakpoint& bp) {
370 if ( _bps.find(bp) == -1) {
371 return JVMTI_ERROR_NOT_FOUND;
372 }
373
374 VM_ChangeBreakpoints clear_breakpoint(VM_ChangeBreakpoints::CLEAR_BREAKPOINT, &bp);
375 VMThread::execute(&clear_breakpoint);
376 return JVMTI_ERROR_NONE;
377 }
378
379 void JvmtiBreakpoints::clearall_in_class_at_safepoint(Klass* klass) {
380 bool changed = true;
381 // We are going to run thru the list of bkpts
382 // and delete some. This deletion probably alters
383 // the list in some implementation defined way such
384 // that when we delete entry i, the next entry might
385 // no longer be at i+1. To be safe, each time we delete
386 // an entry, we'll just start again from the beginning.
387 // We'll stop when we make a pass thru the whole list without
388 // deleting anything.
389 while (changed) {
390 int len = _bps.length();
391 changed = false;
392 for (int i = 0; i < len; i++) {
393 JvmtiBreakpoint& bp = _bps.at(i);
394 if (bp.method()->method_holder() == klass) {
395 bp.clear();
396 _bps.remove(i);
397 // This changed 'i' so we have to start over.
398 changed = true;
399 break;
400 }
401 }
402 }
403 }
404
405 //
406 // class JvmtiCurrentBreakpoints
407 //
408
409 JvmtiBreakpoints *JvmtiCurrentBreakpoints::_jvmti_breakpoints = NULL;
410 address * JvmtiCurrentBreakpoints::_breakpoint_list = NULL;
411
412
413 JvmtiBreakpoints& JvmtiCurrentBreakpoints::get_jvmti_breakpoints() {
414 if (_jvmti_breakpoints != NULL) return (*_jvmti_breakpoints);
415 _jvmti_breakpoints = new JvmtiBreakpoints(listener_fun);
416 assert(_jvmti_breakpoints != NULL, "_jvmti_breakpoints != NULL");
417 return (*_jvmti_breakpoints);
418 }
419
420 void JvmtiCurrentBreakpoints::listener_fun(void *this_obj, address *cache) {
421 JvmtiBreakpoints *this_jvmti = (JvmtiBreakpoints *) this_obj;
422 assert(this_jvmti != NULL, "this_jvmti != NULL");
423
424 debug_only(int n = this_jvmti->length(););
425 assert(cache[n] == NULL, "cache must be NULL terminated");
426
427 set_breakpoint_list(cache);
428 }
429
430 ///////////////////////////////////////////////////////////////
431 //
432 // class VM_GetOrSetLocal
433 //
434
435 // Constructor for non-object getter
436 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, jint depth, jint index, BasicType type)
437 : _thread(thread)
438 , _calling_thread(NULL)
439 , _depth(depth)
440 , _index(index)
441 , _type(type)
442 , _jvf(NULL)
443 , _set(false)
444 , _result(JVMTI_ERROR_NONE)
445 {
446 }
447
448 // Constructor for object or non-object setter
449 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, jint depth, jint index, BasicType type, jvalue value)
450 : _thread(thread)
451 , _calling_thread(NULL)
452 , _depth(depth)
453 , _index(index)
454 , _type(type)
455 , _value(value)
456 , _jvf(NULL)
457 , _set(true)
458 , _result(JVMTI_ERROR_NONE)
459 {
460 }
461
462 // Constructor for object getter
463 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, JavaThread* calling_thread, jint depth, int index)
464 : _thread(thread)
465 , _calling_thread(calling_thread)
466 , _depth(depth)
467 , _index(index)
468 , _type(T_OBJECT)
469 , _jvf(NULL)
470 , _set(false)
471 , _result(JVMTI_ERROR_NONE)
472 {
473 }
474
475 vframe *VM_GetOrSetLocal::get_vframe() {
476 if (!_thread->has_last_Java_frame()) {
477 return NULL;
478 }
479 RegisterMap reg_map(_thread);
480 vframe *vf = _thread->last_java_vframe(®_map);
481 int d = 0;
482 while ((vf != NULL) && (d < _depth)) {
483 vf = vf->java_sender();
484 d++;
485 }
486 return vf;
487 }
488
489 javaVFrame *VM_GetOrSetLocal::get_java_vframe() {
490 vframe* vf = get_vframe();
491 if (vf == NULL) {
492 _result = JVMTI_ERROR_NO_MORE_FRAMES;
493 return NULL;
494 }
495 javaVFrame *jvf = (javaVFrame*)vf;
496
497 if (!vf->is_java_frame()) {
498 _result = JVMTI_ERROR_OPAQUE_FRAME;
499 return NULL;
500 }
501 return jvf;
502 }
503
504 // Check that the klass is assignable to a type with the given signature.
505 // Another solution could be to use the function Klass::is_subtype_of(type).
506 // But the type class can be forced to load/initialize eagerly in such a case.
507 // This may cause unexpected consequences like CFLH or class-init JVMTI events.
508 // It is better to avoid such a behavior.
509 bool VM_GetOrSetLocal::is_assignable(const char* ty_sign, Klass* klass, Thread* thread) {
510 assert(ty_sign != NULL, "type signature must not be NULL");
511 assert(thread != NULL, "thread must not be NULL");
512 assert(klass != NULL, "klass must not be NULL");
513
514 int len = (int) strlen(ty_sign);
515 if (ty_sign[0] == JVM_SIGNATURE_CLASS &&
516 ty_sign[len-1] == JVM_SIGNATURE_ENDCLASS) { // Need pure class/interface name
517 ty_sign++;
518 len -= 2;
519 }
520 TempNewSymbol ty_sym = SymbolTable::new_symbol(ty_sign, len);
521 if (klass->name() == ty_sym) {
522 return true;
523 }
524 // Compare primary supers
525 int super_depth = klass->super_depth();
526 int idx;
527 for (idx = 0; idx < super_depth; idx++) {
528 if (klass->primary_super_of_depth(idx)->name() == ty_sym) {
529 return true;
530 }
531 }
532 // Compare secondary supers
533 const Array<Klass*>* sec_supers = klass->secondary_supers();
534 for (idx = 0; idx < sec_supers->length(); idx++) {
535 if (((Klass*) sec_supers->at(idx))->name() == ty_sym) {
536 return true;
537 }
538 }
539 return false;
540 }
541
542 // Checks error conditions:
543 // JVMTI_ERROR_INVALID_SLOT
544 // JVMTI_ERROR_TYPE_MISMATCH
545 // Returns: 'true' - everything is Ok, 'false' - error code
546
547 bool VM_GetOrSetLocal::check_slot_type_lvt(javaVFrame* jvf) {
548 Method* method_oop = jvf->method();
549 jint num_entries = method_oop->localvariable_table_length();
550 if (num_entries == 0) {
551 _result = JVMTI_ERROR_INVALID_SLOT;
552 return false; // There are no slots
553 }
554 int signature_idx = -1;
555 int vf_bci = jvf->bci();
556 LocalVariableTableElement* table = method_oop->localvariable_table_start();
557 for (int i = 0; i < num_entries; i++) {
558 int start_bci = table[i].start_bci;
559 int end_bci = start_bci + table[i].length;
560
561 // Here we assume that locations of LVT entries
562 // with the same slot number cannot be overlapped
563 if (_index == (jint) table[i].slot && start_bci <= vf_bci && vf_bci <= end_bci) {
564 signature_idx = (int) table[i].descriptor_cp_index;
565 break;
566 }
567 }
568 if (signature_idx == -1) {
569 _result = JVMTI_ERROR_INVALID_SLOT;
570 return false; // Incorrect slot index
571 }
572 Symbol* sign_sym = method_oop->constants()->symbol_at(signature_idx);
573 BasicType slot_type = Signature::basic_type(sign_sym);
574
575 switch (slot_type) {
576 case T_BYTE:
577 case T_SHORT:
578 case T_CHAR:
579 case T_BOOLEAN:
580 slot_type = T_INT;
581 break;
582 case T_ARRAY:
583 slot_type = T_OBJECT;
584 break;
585 default:
586 break;
587 };
588 if (_type != slot_type) {
589 _result = JVMTI_ERROR_TYPE_MISMATCH;
590 return false;
591 }
592
593 jobject jobj = _value.l;
594 if (_set && slot_type == T_OBJECT && jobj != NULL) { // NULL reference is allowed
595 // Check that the jobject class matches the return type signature.
596 JavaThread* cur_thread = JavaThread::current();
597 HandleMark hm(cur_thread);
598
599 Handle obj(cur_thread, JNIHandles::resolve_external_guard(jobj));
600 NULL_CHECK(obj, (_result = JVMTI_ERROR_INVALID_OBJECT, false));
601 Klass* ob_k = obj->klass();
602 NULL_CHECK(ob_k, (_result = JVMTI_ERROR_INVALID_OBJECT, false));
603
604 const char* signature = (const char *) sign_sym->as_utf8();
605 if (!is_assignable(signature, ob_k, cur_thread)) {
606 _result = JVMTI_ERROR_TYPE_MISMATCH;
607 return false;
608 }
609 }
610 return true;
611 }
612
613 bool VM_GetOrSetLocal::check_slot_type_no_lvt(javaVFrame* jvf) {
614 Method* method_oop = jvf->method();
615 jint extra_slot = (_type == T_LONG || _type == T_DOUBLE) ? 1 : 0;
616
617 if (_index < 0 || _index + extra_slot >= method_oop->max_locals()) {
618 _result = JVMTI_ERROR_INVALID_SLOT;
619 return false;
620 }
621 StackValueCollection *locals = _jvf->locals();
622 BasicType slot_type = locals->at(_index)->type();
623
624 if (slot_type == T_CONFLICT) {
625 _result = JVMTI_ERROR_INVALID_SLOT;
626 return false;
627 }
628 if (extra_slot) {
629 BasicType extra_slot_type = locals->at(_index + 1)->type();
630 if (extra_slot_type != T_INT) {
631 _result = JVMTI_ERROR_INVALID_SLOT;
632 return false;
633 }
634 }
635 if (_type != slot_type && (_type == T_OBJECT || slot_type != T_INT)) {
636 _result = JVMTI_ERROR_TYPE_MISMATCH;
637 return false;
638 }
639 return true;
640 }
641
642 static bool can_be_deoptimized(vframe* vf) {
643 return (vf->is_compiled_frame() && vf->fr().can_be_deoptimized());
644 }
645
646 bool VM_GetOrSetLocal::doit_prologue() {
647 _jvf = get_java_vframe();
648 NULL_CHECK(_jvf, false);
649
650 Method* method_oop = _jvf->method();
651 if (getting_receiver()) {
652 if (method_oop->is_static()) {
653 _result = JVMTI_ERROR_INVALID_SLOT;
654 return false;
655 }
656 return true;
657 }
658
659 if (method_oop->is_native()) {
660 _result = JVMTI_ERROR_OPAQUE_FRAME;
661 return false;
662 }
663
664 if (!check_slot_type_no_lvt(_jvf)) {
665 return false;
666 }
667 if (method_oop->has_localvariable_table()) {
668 return check_slot_type_lvt(_jvf);
669 }
670 return true;
671 }
672
673 void VM_GetOrSetLocal::doit() {
674 InterpreterOopMap oop_mask;
675 _jvf->method()->mask_for(_jvf->bci(), &oop_mask);
676 if (oop_mask.is_dead(_index)) {
677 // The local can be invalid and uninitialized in the scope of current bci
678 _result = JVMTI_ERROR_INVALID_SLOT;
679 return;
680 }
681 if (_set) {
682 // Force deoptimization of frame if compiled because it's
683 // possible the compiler emitted some locals as constant values,
684 // meaning they are not mutable.
685 if (can_be_deoptimized(_jvf)) {
686
687 // Schedule deoptimization so that eventually the local
688 // update will be written to an interpreter frame.
689 Deoptimization::deoptimize_frame(_jvf->thread(), _jvf->fr().id());
690
691 // Now store a new value for the local which will be applied
692 // once deoptimization occurs. Note however that while this
693 // write is deferred until deoptimization actually happens
694 // can vframe created after this point will have its locals
695 // reflecting this update so as far as anyone can see the
696 // write has already taken place.
697
698 // If we are updating an oop then get the oop from the handle
699 // since the handle will be long gone by the time the deopt
700 // happens. The oop stored in the deferred local will be
701 // gc'd on its own.
702 if (_type == T_OBJECT) {
703 _value.l = cast_from_oop<jobject>(JNIHandles::resolve_external_guard(_value.l));
704 }
705 // Re-read the vframe so we can see that it is deoptimized
706 // [ Only need because of assert in update_local() ]
707 _jvf = get_java_vframe();
708 ((compiledVFrame*)_jvf)->update_local(_type, _index, _value);
709 return;
710 }
711 StackValueCollection *locals = _jvf->locals();
712 HandleMark hm;
713
714 switch (_type) {
715 case T_INT: locals->set_int_at (_index, _value.i); break;
716 case T_LONG: locals->set_long_at (_index, _value.j); break;
717 case T_FLOAT: locals->set_float_at (_index, _value.f); break;
718 case T_DOUBLE: locals->set_double_at(_index, _value.d); break;
719 case T_OBJECT: {
720 Handle ob_h(Thread::current(), JNIHandles::resolve_external_guard(_value.l));
721 locals->set_obj_at (_index, ob_h);
722 break;
723 }
724 default: ShouldNotReachHere();
725 }
726 _jvf->set_locals(locals);
727 } else {
728 if (_jvf->method()->is_native() && _jvf->is_compiled_frame()) {
729 assert(getting_receiver(), "Can only get here when getting receiver");
730 oop receiver = _jvf->fr().get_native_receiver();
731 _value.l = JNIHandles::make_local(_calling_thread, receiver);
732 } else {
733 StackValueCollection *locals = _jvf->locals();
734
735 switch (_type) {
736 case T_INT: _value.i = locals->int_at (_index); break;
737 case T_LONG: _value.j = locals->long_at (_index); break;
738 case T_FLOAT: _value.f = locals->float_at (_index); break;
739 case T_DOUBLE: _value.d = locals->double_at(_index); break;
740 case T_OBJECT: {
741 // Wrap the oop to be returned in a local JNI handle since
742 // oops_do() no longer applies after doit() is finished.
743 oop obj = locals->obj_at(_index)();
744 _value.l = JNIHandles::make_local(_calling_thread, obj);
745 break;
746 }
747 default: ShouldNotReachHere();
748 }
749 }
750 }
751 }
752
753
754 bool VM_GetOrSetLocal::allow_nested_vm_operations() const {
755 return true; // May need to deoptimize
756 }
757
758
759 VM_GetReceiver::VM_GetReceiver(
760 JavaThread* thread, JavaThread* caller_thread, jint depth)
761 : VM_GetOrSetLocal(thread, caller_thread, depth, 0) {}
762
763 /////////////////////////////////////////////////////////////////////////////////////////
764
765 //
766 // class JvmtiSuspendControl - see comments in jvmtiImpl.hpp
767 //
768
769 bool JvmtiSuspendControl::suspend(JavaThread *java_thread) {
770 // external suspend should have caught suspending a thread twice
771
772 // Immediate suspension required for JPDA back-end so JVMTI agent threads do
773 // not deadlock due to later suspension on transitions while holding
774 // raw monitors. Passing true causes the immediate suspension.
775 // java_suspend() will catch threads in the process of exiting
776 // and will ignore them.
777 java_thread->java_suspend();
778
779 // It would be nice to have the following assertion in all the time,
780 // but it is possible for a racing resume request to have resumed
781 // this thread right after we suspended it. Temporarily enable this
782 // assertion if you are chasing a different kind of bug.
783 //
784 // assert(java_lang_Thread::thread(java_thread->threadObj()) == NULL ||
785 // java_thread->is_being_ext_suspended(), "thread is not suspended");
786
787 if (java_lang_Thread::thread(java_thread->threadObj()) == NULL) {
788 // check again because we can get delayed in java_suspend():
789 // the thread is in process of exiting.
790 return false;
791 }
792
793 return true;
794 }
795
796 bool JvmtiSuspendControl::resume(JavaThread *java_thread) {
797 // external suspend should have caught resuming a thread twice
798 assert(java_thread->is_being_ext_suspended(), "thread should be suspended");
799
800 // resume thread
801 {
802 // must always grab Threads_lock, see JVM_SuspendThread
803 MutexLocker ml(Threads_lock);
804 java_thread->java_resume();
805 }
806
807 return true;
808 }
809
810
811 void JvmtiSuspendControl::print() {
812 #ifndef PRODUCT
813 ResourceMark rm;
814 LogStreamHandle(Trace, jvmti) log_stream;
815 log_stream.print("Suspended Threads: [");
816 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *thread = jtiwh.next(); ) {
817 #ifdef JVMTI_TRACE
818 const char *name = JvmtiTrace::safe_get_thread_name(thread);
819 #else
820 const char *name = "";
821 #endif /*JVMTI_TRACE */
822 log_stream.print("%s(%c ", name, thread->is_being_ext_suspended() ? 'S' : '_');
823 if (!thread->has_last_Java_frame()) {
824 log_stream.print("no stack");
825 }
826 log_stream.print(") ");
827 }
828 log_stream.print_cr("]");
829 #endif
830 }
831
832 JvmtiDeferredEvent JvmtiDeferredEvent::compiled_method_load_event(
833 nmethod* nm) {
834 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_COMPILED_METHOD_LOAD);
835 event._event_data.compiled_method_load = nm;
836 return event;
837 }
838
839 JvmtiDeferredEvent JvmtiDeferredEvent::compiled_method_unload_event(
840 jmethodID id, const void* code) {
841 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_COMPILED_METHOD_UNLOAD);
842 event._event_data.compiled_method_unload.method_id = id;
843 event._event_data.compiled_method_unload.code_begin = code;
844 return event;
845 }
846
847 JvmtiDeferredEvent JvmtiDeferredEvent::dynamic_code_generated_event(
848 const char* name, const void* code_begin, const void* code_end) {
849 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_DYNAMIC_CODE_GENERATED);
850 // Need to make a copy of the name since we don't know how long
851 // the event poster will keep it around after we enqueue the
852 // deferred event and return. strdup() failure is handled in
853 // the post() routine below.
854 event._event_data.dynamic_code_generated.name = os::strdup(name);
855 event._event_data.dynamic_code_generated.code_begin = code_begin;
856 event._event_data.dynamic_code_generated.code_end = code_end;
857 return event;
858 }
859
860 JvmtiDeferredEvent JvmtiDeferredEvent::class_unload_event(const char* name) {
861 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_CLASS_UNLOAD);
862 // Need to make a copy of the name since we don't know how long
863 // the event poster will keep it around after we enqueue the
864 // deferred event and return. strdup() failure is handled in
865 // the post() routine below.
866 event._event_data.class_unload.name = os::strdup(name);
867 return event;
868 }
869
870 void JvmtiDeferredEvent::post() {
871 assert(Thread::current()->is_service_thread(),
872 "Service thread must post enqueued events");
873 switch(_type) {
874 case TYPE_COMPILED_METHOD_LOAD: {
875 nmethod* nm = _event_data.compiled_method_load;
876 JvmtiExport::post_compiled_method_load(nm);
877 break;
878 }
879 case TYPE_COMPILED_METHOD_UNLOAD: {
880 JvmtiExport::post_compiled_method_unload(
881 _event_data.compiled_method_unload.method_id,
882 _event_data.compiled_method_unload.code_begin);
883 break;
884 }
885 case TYPE_DYNAMIC_CODE_GENERATED: {
886 JvmtiExport::post_dynamic_code_generated_internal(
887 // if strdup failed give the event a default name
888 (_event_data.dynamic_code_generated.name == NULL)
889 ? "unknown_code" : _event_data.dynamic_code_generated.name,
890 _event_data.dynamic_code_generated.code_begin,
891 _event_data.dynamic_code_generated.code_end);
892 if (_event_data.dynamic_code_generated.name != NULL) {
893 // release our copy
894 os::free((void *)_event_data.dynamic_code_generated.name);
895 }
896 break;
897 }
898 case TYPE_CLASS_UNLOAD: {
899 JvmtiExport::post_class_unload_internal(
900 // if strdup failed give the event a default name
901 (_event_data.class_unload.name == NULL)
902 ? "unknown_class" : _event_data.class_unload.name);
903 if (_event_data.class_unload.name != NULL) {
904 // release our copy
905 os::free((void *)_event_data.class_unload.name);
906 }
907 break;
908 }
909 default:
910 ShouldNotReachHere();
911 }
912 }
913
914 void JvmtiDeferredEvent::post_compiled_method_load_event(JvmtiEnv* env) {
915 assert(_type == TYPE_COMPILED_METHOD_LOAD, "only user of this method");
916 nmethod* nm = _event_data.compiled_method_load;
917 JvmtiExport::post_compiled_method_load(env, nm);
918 }
919
920 void JvmtiDeferredEvent::run_nmethod_entry_barriers() {
921 if (_type == TYPE_COMPILED_METHOD_LOAD) {
922 _event_data.compiled_method_load->run_nmethod_entry_barrier();
923 }
924 }
925
926
927 // Keep the nmethod for compiled_method_load from being unloaded.
928 void JvmtiDeferredEvent::oops_do(OopClosure* f, CodeBlobClosure* cf) {
929 if (cf != NULL && _type == TYPE_COMPILED_METHOD_LOAD) {
930 cf->do_code_blob(_event_data.compiled_method_load);
931 }
932 }
933
934 // The sweeper calls this and marks the nmethods here on the stack so that
935 // they cannot be turned into zombies while in the queue.
936 void JvmtiDeferredEvent::nmethods_do(CodeBlobClosure* cf) {
937 if (cf != NULL && _type == TYPE_COMPILED_METHOD_LOAD) {
938 cf->do_code_blob(_event_data.compiled_method_load);
939 }
940 }
941
942
943 bool JvmtiDeferredEventQueue::has_events() {
944 // We save the queued events before the live phase and post them when it starts.
945 // This code could skip saving the events on the queue before the live
946 // phase and ignore them, but this would change how we do things now.
947 // Starting the service thread earlier causes this to be called before the live phase begins.
948 // The events on the queue should all be posted after the live phase so this is an
949 // ok check. Before the live phase, DynamicCodeGenerated events are posted directly.
950 // If we add other types of events to the deferred queue, this could get ugly.
951 return JvmtiEnvBase::get_phase() == JVMTI_PHASE_LIVE && _queue_head != NULL;
952 }
953
954 void JvmtiDeferredEventQueue::enqueue(JvmtiDeferredEvent event) {
955 // Events get added to the end of the queue (and are pulled off the front).
956 QueueNode* node = new QueueNode(event);
957 if (_queue_tail == NULL) {
958 _queue_tail = _queue_head = node;
959 } else {
960 assert(_queue_tail->next() == NULL, "Must be the last element in the list");
961 _queue_tail->set_next(node);
962 _queue_tail = node;
963 }
964
965 assert((_queue_head == NULL) == (_queue_tail == NULL),
966 "Inconsistent queue markers");
967 }
968
969 JvmtiDeferredEvent JvmtiDeferredEventQueue::dequeue() {
970 assert(_queue_head != NULL, "Nothing to dequeue");
971
972 if (_queue_head == NULL) {
973 // Just in case this happens in product; it shouldn't but let's not crash
974 return JvmtiDeferredEvent();
975 }
976
977 QueueNode* node = _queue_head;
978 _queue_head = _queue_head->next();
979 if (_queue_head == NULL) {
980 _queue_tail = NULL;
981 }
982
983 assert((_queue_head == NULL) == (_queue_tail == NULL),
984 "Inconsistent queue markers");
985
986 JvmtiDeferredEvent event = node->event();
987 delete node;
988 return event;
989 }
990
991 void JvmtiDeferredEventQueue::post(JvmtiEnv* env) {
992 // Post and destroy queue nodes
993 while (_queue_head != NULL) {
994 JvmtiDeferredEvent event = dequeue();
995 event.post_compiled_method_load_event(env);
996 }
997 }
998
999 void JvmtiDeferredEventQueue::run_nmethod_entry_barriers() {
1000 for(QueueNode* node = _queue_head; node != NULL; node = node->next()) {
1001 node->event().run_nmethod_entry_barriers();
1002 }
1003 }
1004
1005
1006 void JvmtiDeferredEventQueue::oops_do(OopClosure* f, CodeBlobClosure* cf) {
1007 for(QueueNode* node = _queue_head; node != NULL; node = node->next()) {
1008 node->event().oops_do(f, cf);
1009 }
1010 }
1011
1012 void JvmtiDeferredEventQueue::nmethods_do(CodeBlobClosure* cf) {
1013 for(QueueNode* node = _queue_head; node != NULL; node = node->next()) {
1014 node->event().nmethods_do(cf);
1015 }
1016 }