1 /* 2 * Copyright (c) 2003, 2017, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "classfile/systemDictionary.hpp" 27 #include "interpreter/interpreter.hpp" 28 #include "interpreter/oopMapCache.hpp" 29 #include "jvmtifiles/jvmtiEnv.hpp" 30 #include "logging/log.hpp" 31 #include "logging/logStream.hpp" 32 #include "memory/resourceArea.hpp" 33 #include "oops/instanceKlass.hpp" 34 #include "oops/oop.inline.hpp" 35 #include "prims/jvmtiAgentThread.hpp" 36 #include "prims/jvmtiEventController.inline.hpp" 37 #include "prims/jvmtiImpl.hpp" 38 #include "prims/jvmtiRedefineClasses.hpp" 39 #include "runtime/atomic.hpp" 40 #include "runtime/deoptimization.hpp" 41 #include "runtime/handles.hpp" 42 #include "runtime/handles.inline.hpp" 43 #include "runtime/interfaceSupport.hpp" 44 #include "runtime/javaCalls.hpp" 45 #include "runtime/os.hpp" 46 #include "runtime/serviceThread.hpp" 47 #include "runtime/signature.hpp" 48 #include "runtime/thread.inline.hpp" 49 #include "runtime/threadSMR.hpp" 50 #include "runtime/vframe.hpp" 51 #include "runtime/vframe_hp.hpp" 52 #include "runtime/vm_operations.hpp" 53 #include "utilities/exceptions.hpp" 54 55 // 56 // class JvmtiAgentThread 57 // 58 // JavaThread used to wrap a thread started by an agent 59 // using the JVMTI method RunAgentThread. 60 // 61 62 JvmtiAgentThread::JvmtiAgentThread(JvmtiEnv* env, jvmtiStartFunction start_fn, const void *start_arg) 63 : JavaThread(start_function_wrapper) { 64 _env = env; 65 _start_fn = start_fn; 66 _start_arg = start_arg; 67 } 68 69 void 70 JvmtiAgentThread::start_function_wrapper(JavaThread *thread, TRAPS) { 71 // It is expected that any Agent threads will be created as 72 // Java Threads. If this is the case, notification of the creation 73 // of the thread is given in JavaThread::thread_main(). 74 assert(thread->is_Java_thread(), "debugger thread should be a Java Thread"); 75 assert(thread == JavaThread::current(), "sanity check"); 76 77 JvmtiAgentThread *dthread = (JvmtiAgentThread *)thread; 78 dthread->call_start_function(); 79 } 80 81 void 82 JvmtiAgentThread::call_start_function() { 83 ThreadToNativeFromVM transition(this); 84 _start_fn(_env->jvmti_external(), jni_environment(), (void*)_start_arg); 85 } 86 87 88 // 89 // class GrowableCache - private methods 90 // 91 92 void GrowableCache::recache() { 93 int len = _elements->length(); 94 95 FREE_C_HEAP_ARRAY(address, _cache); 96 _cache = NEW_C_HEAP_ARRAY(address,len+1, mtInternal); 97 98 for (int i=0; i<len; i++) { 99 _cache[i] = _elements->at(i)->getCacheValue(); 100 // 101 // The cache entry has gone bad. Without a valid frame pointer 102 // value, the entry is useless so we simply delete it in product 103 // mode. The call to remove() will rebuild the cache again 104 // without the bad entry. 105 // 106 if (_cache[i] == NULL) { 107 assert(false, "cannot recache NULL elements"); 108 remove(i); 109 return; 110 } 111 } 112 _cache[len] = NULL; 113 114 _listener_fun(_this_obj,_cache); 115 } 116 117 bool GrowableCache::equals(void* v, GrowableElement *e2) { 118 GrowableElement *e1 = (GrowableElement *) v; 119 assert(e1 != NULL, "e1 != NULL"); 120 assert(e2 != NULL, "e2 != NULL"); 121 122 return e1->equals(e2); 123 } 124 125 // 126 // class GrowableCache - public methods 127 // 128 129 GrowableCache::GrowableCache() { 130 _this_obj = NULL; 131 _listener_fun = NULL; 132 _elements = NULL; 133 _cache = NULL; 134 } 135 136 GrowableCache::~GrowableCache() { 137 clear(); 138 delete _elements; 139 FREE_C_HEAP_ARRAY(address, _cache); 140 } 141 142 void GrowableCache::initialize(void *this_obj, void listener_fun(void *, address*) ) { 143 _this_obj = this_obj; 144 _listener_fun = listener_fun; 145 _elements = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<GrowableElement*>(5,true); 146 recache(); 147 } 148 149 // number of elements in the collection 150 int GrowableCache::length() { 151 return _elements->length(); 152 } 153 154 // get the value of the index element in the collection 155 GrowableElement* GrowableCache::at(int index) { 156 GrowableElement *e = (GrowableElement *) _elements->at(index); 157 assert(e != NULL, "e != NULL"); 158 return e; 159 } 160 161 int GrowableCache::find(GrowableElement* e) { 162 return _elements->find(e, GrowableCache::equals); 163 } 164 165 // append a copy of the element to the end of the collection 166 void GrowableCache::append(GrowableElement* e) { 167 GrowableElement *new_e = e->clone(); 168 _elements->append(new_e); 169 recache(); 170 } 171 172 // insert a copy of the element using lessthan() 173 void GrowableCache::insert(GrowableElement* e) { 174 GrowableElement *new_e = e->clone(); 175 _elements->append(new_e); 176 177 int n = length()-2; 178 for (int i=n; i>=0; i--) { 179 GrowableElement *e1 = _elements->at(i); 180 GrowableElement *e2 = _elements->at(i+1); 181 if (e2->lessThan(e1)) { 182 _elements->at_put(i+1, e1); 183 _elements->at_put(i, e2); 184 } 185 } 186 187 recache(); 188 } 189 190 // remove the element at index 191 void GrowableCache::remove (int index) { 192 GrowableElement *e = _elements->at(index); 193 assert(e != NULL, "e != NULL"); 194 _elements->remove(e); 195 delete e; 196 recache(); 197 } 198 199 // clear out all elements, release all heap space and 200 // let our listener know that things have changed. 201 void GrowableCache::clear() { 202 int len = _elements->length(); 203 for (int i=0; i<len; i++) { 204 delete _elements->at(i); 205 } 206 _elements->clear(); 207 recache(); 208 } 209 210 void GrowableCache::oops_do(OopClosure* f) { 211 int len = _elements->length(); 212 for (int i=0; i<len; i++) { 213 GrowableElement *e = _elements->at(i); 214 e->oops_do(f); 215 } 216 } 217 218 void GrowableCache::metadata_do(void f(Metadata*)) { 219 int len = _elements->length(); 220 for (int i=0; i<len; i++) { 221 GrowableElement *e = _elements->at(i); 222 e->metadata_do(f); 223 } 224 } 225 226 void GrowableCache::gc_epilogue() { 227 int len = _elements->length(); 228 for (int i=0; i<len; i++) { 229 _cache[i] = _elements->at(i)->getCacheValue(); 230 } 231 } 232 233 // 234 // class JvmtiBreakpoint 235 // 236 237 JvmtiBreakpoint::JvmtiBreakpoint() { 238 _method = NULL; 239 _bci = 0; 240 _class_holder = NULL; 241 } 242 243 JvmtiBreakpoint::JvmtiBreakpoint(Method* m_method, jlocation location) { 244 _method = m_method; 245 _class_holder = _method->method_holder()->klass_holder(); 246 #ifdef CHECK_UNHANDLED_OOPS 247 // _class_holder can't be wrapped in a Handle, because JvmtiBreakpoints are 248 // sometimes allocated on the heap. 249 // 250 // The code handling JvmtiBreakpoints allocated on the stack can't be 251 // interrupted by a GC until _class_holder is reachable by the GC via the 252 // oops_do method. 253 Thread::current()->allow_unhandled_oop(&_class_holder); 254 #endif // CHECK_UNHANDLED_OOPS 255 assert(_method != NULL, "_method != NULL"); 256 _bci = (int) location; 257 assert(_bci >= 0, "_bci >= 0"); 258 } 259 260 void JvmtiBreakpoint::copy(JvmtiBreakpoint& bp) { 261 _method = bp._method; 262 _bci = bp._bci; 263 _class_holder = bp._class_holder; 264 } 265 266 bool JvmtiBreakpoint::lessThan(JvmtiBreakpoint& bp) { 267 Unimplemented(); 268 return false; 269 } 270 271 bool JvmtiBreakpoint::equals(JvmtiBreakpoint& bp) { 272 return _method == bp._method 273 && _bci == bp._bci; 274 } 275 276 bool JvmtiBreakpoint::is_valid() { 277 // class loader can be NULL 278 return _method != NULL && 279 _bci >= 0; 280 } 281 282 address JvmtiBreakpoint::getBcp() const { 283 return _method->bcp_from(_bci); 284 } 285 286 void JvmtiBreakpoint::each_method_version_do(method_action meth_act) { 287 ((Method*)_method->*meth_act)(_bci); 288 289 // add/remove breakpoint to/from versions of the method that are EMCP. 290 Thread *thread = Thread::current(); 291 InstanceKlass* ik = _method->method_holder(); 292 Symbol* m_name = _method->name(); 293 Symbol* m_signature = _method->signature(); 294 295 // search previous versions if they exist 296 for (InstanceKlass* pv_node = ik->previous_versions(); 297 pv_node != NULL; 298 pv_node = pv_node->previous_versions()) { 299 Array<Method*>* methods = pv_node->methods(); 300 301 for (int i = methods->length() - 1; i >= 0; i--) { 302 Method* method = methods->at(i); 303 // Only set breakpoints in running EMCP methods. 304 if (method->is_running_emcp() && 305 method->name() == m_name && 306 method->signature() == m_signature) { 307 ResourceMark rm; 308 log_debug(redefine, class, breakpoint) 309 ("%sing breakpoint in %s(%s)", meth_act == &Method::set_breakpoint ? "sett" : "clear", 310 method->name()->as_C_string(), method->signature()->as_C_string()); 311 (method->*meth_act)(_bci); 312 break; 313 } 314 } 315 } 316 } 317 318 void JvmtiBreakpoint::set() { 319 each_method_version_do(&Method::set_breakpoint); 320 } 321 322 void JvmtiBreakpoint::clear() { 323 each_method_version_do(&Method::clear_breakpoint); 324 } 325 326 void JvmtiBreakpoint::print_on(outputStream* out) const { 327 #ifndef PRODUCT 328 ResourceMark rm; 329 const char *class_name = (_method == NULL) ? "NULL" : _method->klass_name()->as_C_string(); 330 const char *method_name = (_method == NULL) ? "NULL" : _method->name()->as_C_string(); 331 out->print("Breakpoint(%s,%s,%d,%p)", class_name, method_name, _bci, getBcp()); 332 #endif 333 } 334 335 336 // 337 // class VM_ChangeBreakpoints 338 // 339 // Modify the Breakpoints data structure at a safepoint 340 // 341 342 void VM_ChangeBreakpoints::doit() { 343 switch (_operation) { 344 case SET_BREAKPOINT: 345 _breakpoints->set_at_safepoint(*_bp); 346 break; 347 case CLEAR_BREAKPOINT: 348 _breakpoints->clear_at_safepoint(*_bp); 349 break; 350 default: 351 assert(false, "Unknown operation"); 352 } 353 } 354 355 void VM_ChangeBreakpoints::oops_do(OopClosure* f) { 356 // The JvmtiBreakpoints in _breakpoints will be visited via 357 // JvmtiExport::oops_do. 358 if (_bp != NULL) { 359 _bp->oops_do(f); 360 } 361 } 362 363 void VM_ChangeBreakpoints::metadata_do(void f(Metadata*)) { 364 // Walk metadata in breakpoints to keep from being deallocated with RedefineClasses 365 if (_bp != NULL) { 366 _bp->metadata_do(f); 367 } 368 } 369 370 // 371 // class JvmtiBreakpoints 372 // 373 // a JVMTI internal collection of JvmtiBreakpoint 374 // 375 376 JvmtiBreakpoints::JvmtiBreakpoints(void listener_fun(void *,address *)) { 377 _bps.initialize(this,listener_fun); 378 } 379 380 JvmtiBreakpoints:: ~JvmtiBreakpoints() {} 381 382 void JvmtiBreakpoints::oops_do(OopClosure* f) { 383 _bps.oops_do(f); 384 } 385 386 void JvmtiBreakpoints::metadata_do(void f(Metadata*)) { 387 _bps.metadata_do(f); 388 } 389 390 void JvmtiBreakpoints::gc_epilogue() { 391 _bps.gc_epilogue(); 392 } 393 394 void JvmtiBreakpoints::print() { 395 #ifndef PRODUCT 396 LogTarget(Trace, jvmti) log; 397 LogStream log_stream(log); 398 399 int n = _bps.length(); 400 for (int i=0; i<n; i++) { 401 JvmtiBreakpoint& bp = _bps.at(i); 402 log_stream.print("%d: ", i); 403 bp.print_on(&log_stream); 404 log_stream.cr(); 405 } 406 #endif 407 } 408 409 410 void JvmtiBreakpoints::set_at_safepoint(JvmtiBreakpoint& bp) { 411 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint"); 412 413 int i = _bps.find(bp); 414 if (i == -1) { 415 _bps.append(bp); 416 bp.set(); 417 } 418 } 419 420 void JvmtiBreakpoints::clear_at_safepoint(JvmtiBreakpoint& bp) { 421 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint"); 422 423 int i = _bps.find(bp); 424 if (i != -1) { 425 _bps.remove(i); 426 bp.clear(); 427 } 428 } 429 430 int JvmtiBreakpoints::length() { return _bps.length(); } 431 432 int JvmtiBreakpoints::set(JvmtiBreakpoint& bp) { 433 if ( _bps.find(bp) != -1) { 434 return JVMTI_ERROR_DUPLICATE; 435 } 436 VM_ChangeBreakpoints set_breakpoint(VM_ChangeBreakpoints::SET_BREAKPOINT, &bp); 437 VMThread::execute(&set_breakpoint); 438 return JVMTI_ERROR_NONE; 439 } 440 441 int JvmtiBreakpoints::clear(JvmtiBreakpoint& bp) { 442 if ( _bps.find(bp) == -1) { 443 return JVMTI_ERROR_NOT_FOUND; 444 } 445 446 VM_ChangeBreakpoints clear_breakpoint(VM_ChangeBreakpoints::CLEAR_BREAKPOINT, &bp); 447 VMThread::execute(&clear_breakpoint); 448 return JVMTI_ERROR_NONE; 449 } 450 451 void JvmtiBreakpoints::clearall_in_class_at_safepoint(Klass* klass) { 452 bool changed = true; 453 // We are going to run thru the list of bkpts 454 // and delete some. This deletion probably alters 455 // the list in some implementation defined way such 456 // that when we delete entry i, the next entry might 457 // no longer be at i+1. To be safe, each time we delete 458 // an entry, we'll just start again from the beginning. 459 // We'll stop when we make a pass thru the whole list without 460 // deleting anything. 461 while (changed) { 462 int len = _bps.length(); 463 changed = false; 464 for (int i = 0; i < len; i++) { 465 JvmtiBreakpoint& bp = _bps.at(i); 466 if (bp.method()->method_holder() == klass) { 467 bp.clear(); 468 _bps.remove(i); 469 // This changed 'i' so we have to start over. 470 changed = true; 471 break; 472 } 473 } 474 } 475 } 476 477 // 478 // class JvmtiCurrentBreakpoints 479 // 480 481 JvmtiBreakpoints *JvmtiCurrentBreakpoints::_jvmti_breakpoints = NULL; 482 address * JvmtiCurrentBreakpoints::_breakpoint_list = NULL; 483 484 485 JvmtiBreakpoints& JvmtiCurrentBreakpoints::get_jvmti_breakpoints() { 486 if (_jvmti_breakpoints != NULL) return (*_jvmti_breakpoints); 487 _jvmti_breakpoints = new JvmtiBreakpoints(listener_fun); 488 assert(_jvmti_breakpoints != NULL, "_jvmti_breakpoints != NULL"); 489 return (*_jvmti_breakpoints); 490 } 491 492 void JvmtiCurrentBreakpoints::listener_fun(void *this_obj, address *cache) { 493 JvmtiBreakpoints *this_jvmti = (JvmtiBreakpoints *) this_obj; 494 assert(this_jvmti != NULL, "this_jvmti != NULL"); 495 496 debug_only(int n = this_jvmti->length();); 497 assert(cache[n] == NULL, "cache must be NULL terminated"); 498 499 set_breakpoint_list(cache); 500 } 501 502 503 void JvmtiCurrentBreakpoints::oops_do(OopClosure* f) { 504 if (_jvmti_breakpoints != NULL) { 505 _jvmti_breakpoints->oops_do(f); 506 } 507 } 508 509 void JvmtiCurrentBreakpoints::metadata_do(void f(Metadata*)) { 510 if (_jvmti_breakpoints != NULL) { 511 _jvmti_breakpoints->metadata_do(f); 512 } 513 } 514 515 void JvmtiCurrentBreakpoints::gc_epilogue() { 516 if (_jvmti_breakpoints != NULL) { 517 _jvmti_breakpoints->gc_epilogue(); 518 } 519 } 520 521 /////////////////////////////////////////////////////////////// 522 // 523 // class VM_GetOrSetLocal 524 // 525 526 // Constructor for non-object getter 527 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, jint depth, int index, BasicType type) 528 : _thread(thread) 529 , _calling_thread(NULL) 530 , _depth(depth) 531 , _index(index) 532 , _type(type) 533 , _set(false) 534 , _jvf(NULL) 535 , _result(JVMTI_ERROR_NONE) 536 { 537 } 538 539 // Constructor for object or non-object setter 540 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, jint depth, int index, BasicType type, jvalue value) 541 : _thread(thread) 542 , _calling_thread(NULL) 543 , _depth(depth) 544 , _index(index) 545 , _type(type) 546 , _value(value) 547 , _set(true) 548 , _jvf(NULL) 549 , _result(JVMTI_ERROR_NONE) 550 { 551 } 552 553 // Constructor for object getter 554 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, JavaThread* calling_thread, jint depth, int index) 555 : _thread(thread) 556 , _calling_thread(calling_thread) 557 , _depth(depth) 558 , _index(index) 559 , _type(T_OBJECT) 560 , _set(false) 561 , _jvf(NULL) 562 , _result(JVMTI_ERROR_NONE) 563 { 564 } 565 566 vframe *VM_GetOrSetLocal::get_vframe() { 567 if (!_thread->has_last_Java_frame()) { 568 return NULL; 569 } 570 RegisterMap reg_map(_thread); 571 vframe *vf = _thread->last_java_vframe(®_map); 572 int d = 0; 573 while ((vf != NULL) && (d < _depth)) { 574 vf = vf->java_sender(); 575 d++; 576 } 577 return vf; 578 } 579 580 javaVFrame *VM_GetOrSetLocal::get_java_vframe() { 581 vframe* vf = get_vframe(); 582 if (vf == NULL) { 583 _result = JVMTI_ERROR_NO_MORE_FRAMES; 584 return NULL; 585 } 586 javaVFrame *jvf = (javaVFrame*)vf; 587 588 if (!vf->is_java_frame()) { 589 _result = JVMTI_ERROR_OPAQUE_FRAME; 590 return NULL; 591 } 592 return jvf; 593 } 594 595 // Check that the klass is assignable to a type with the given signature. 596 // Another solution could be to use the function Klass::is_subtype_of(type). 597 // But the type class can be forced to load/initialize eagerly in such a case. 598 // This may cause unexpected consequences like CFLH or class-init JVMTI events. 599 // It is better to avoid such a behavior. 600 bool VM_GetOrSetLocal::is_assignable(const char* ty_sign, Klass* klass, Thread* thread) { 601 assert(ty_sign != NULL, "type signature must not be NULL"); 602 assert(thread != NULL, "thread must not be NULL"); 603 assert(klass != NULL, "klass must not be NULL"); 604 605 int len = (int) strlen(ty_sign); 606 if (ty_sign[0] == 'L' && ty_sign[len-1] == ';') { // Need pure class/interface name 607 ty_sign++; 608 len -= 2; 609 } 610 TempNewSymbol ty_sym = SymbolTable::new_symbol(ty_sign, len, thread); 611 if (klass->name() == ty_sym) { 612 return true; 613 } 614 // Compare primary supers 615 int super_depth = klass->super_depth(); 616 int idx; 617 for (idx = 0; idx < super_depth; idx++) { 618 if (klass->primary_super_of_depth(idx)->name() == ty_sym) { 619 return true; 620 } 621 } 622 // Compare secondary supers 623 Array<Klass*>* sec_supers = klass->secondary_supers(); 624 for (idx = 0; idx < sec_supers->length(); idx++) { 625 if (((Klass*) sec_supers->at(idx))->name() == ty_sym) { 626 return true; 627 } 628 } 629 return false; 630 } 631 632 // Checks error conditions: 633 // JVMTI_ERROR_INVALID_SLOT 634 // JVMTI_ERROR_TYPE_MISMATCH 635 // Returns: 'true' - everything is Ok, 'false' - error code 636 637 bool VM_GetOrSetLocal::check_slot_type(javaVFrame* jvf) { 638 Method* method_oop = jvf->method(); 639 if (!method_oop->has_localvariable_table()) { 640 // Just to check index boundaries 641 jint extra_slot = (_type == T_LONG || _type == T_DOUBLE) ? 1 : 0; 642 if (_index < 0 || _index + extra_slot >= method_oop->max_locals()) { 643 _result = JVMTI_ERROR_INVALID_SLOT; 644 return false; 645 } 646 return true; 647 } 648 649 jint num_entries = method_oop->localvariable_table_length(); 650 if (num_entries == 0) { 651 _result = JVMTI_ERROR_INVALID_SLOT; 652 return false; // There are no slots 653 } 654 int signature_idx = -1; 655 int vf_bci = jvf->bci(); 656 LocalVariableTableElement* table = method_oop->localvariable_table_start(); 657 for (int i = 0; i < num_entries; i++) { 658 int start_bci = table[i].start_bci; 659 int end_bci = start_bci + table[i].length; 660 661 // Here we assume that locations of LVT entries 662 // with the same slot number cannot be overlapped 663 if (_index == (jint) table[i].slot && start_bci <= vf_bci && vf_bci <= end_bci) { 664 signature_idx = (int) table[i].descriptor_cp_index; 665 break; 666 } 667 } 668 if (signature_idx == -1) { 669 _result = JVMTI_ERROR_INVALID_SLOT; 670 return false; // Incorrect slot index 671 } 672 Symbol* sign_sym = method_oop->constants()->symbol_at(signature_idx); 673 const char* signature = (const char *) sign_sym->as_utf8(); 674 BasicType slot_type = char2type(signature[0]); 675 676 switch (slot_type) { 677 case T_BYTE: 678 case T_SHORT: 679 case T_CHAR: 680 case T_BOOLEAN: 681 slot_type = T_INT; 682 break; 683 case T_ARRAY: 684 slot_type = T_OBJECT; 685 break; 686 default: 687 break; 688 }; 689 if (_type != slot_type) { 690 _result = JVMTI_ERROR_TYPE_MISMATCH; 691 return false; 692 } 693 694 jobject jobj = _value.l; 695 if (_set && slot_type == T_OBJECT && jobj != NULL) { // NULL reference is allowed 696 // Check that the jobject class matches the return type signature. 697 JavaThread* cur_thread = JavaThread::current(); 698 HandleMark hm(cur_thread); 699 700 Handle obj(cur_thread, JNIHandles::resolve_external_guard(jobj)); 701 NULL_CHECK(obj, (_result = JVMTI_ERROR_INVALID_OBJECT, false)); 702 Klass* ob_k = obj->klass(); 703 NULL_CHECK(ob_k, (_result = JVMTI_ERROR_INVALID_OBJECT, false)); 704 705 if (!is_assignable(signature, ob_k, cur_thread)) { 706 _result = JVMTI_ERROR_TYPE_MISMATCH; 707 return false; 708 } 709 } 710 return true; 711 } 712 713 static bool can_be_deoptimized(vframe* vf) { 714 return (vf->is_compiled_frame() && vf->fr().can_be_deoptimized()); 715 } 716 717 bool VM_GetOrSetLocal::doit_prologue() { 718 _jvf = get_java_vframe(); 719 NULL_CHECK(_jvf, false); 720 721 if (_jvf->method()->is_native()) { 722 if (getting_receiver() && !_jvf->method()->is_static()) { 723 return true; 724 } else { 725 _result = JVMTI_ERROR_OPAQUE_FRAME; 726 return false; 727 } 728 } 729 730 if (!check_slot_type(_jvf)) { 731 return false; 732 } 733 return true; 734 } 735 736 void VM_GetOrSetLocal::doit() { 737 InterpreterOopMap oop_mask; 738 _jvf->method()->mask_for(_jvf->bci(), &oop_mask); 739 if (oop_mask.is_dead(_index)) { 740 // The local can be invalid and uninitialized in the scope of current bci 741 _result = JVMTI_ERROR_INVALID_SLOT; 742 return; 743 } 744 if (_set) { 745 // Force deoptimization of frame if compiled because it's 746 // possible the compiler emitted some locals as constant values, 747 // meaning they are not mutable. 748 if (can_be_deoptimized(_jvf)) { 749 750 // Schedule deoptimization so that eventually the local 751 // update will be written to an interpreter frame. 752 Deoptimization::deoptimize_frame(_jvf->thread(), _jvf->fr().id()); 753 754 // Now store a new value for the local which will be applied 755 // once deoptimization occurs. Note however that while this 756 // write is deferred until deoptimization actually happens 757 // can vframe created after this point will have its locals 758 // reflecting this update so as far as anyone can see the 759 // write has already taken place. 760 761 // If we are updating an oop then get the oop from the handle 762 // since the handle will be long gone by the time the deopt 763 // happens. The oop stored in the deferred local will be 764 // gc'd on its own. 765 if (_type == T_OBJECT) { 766 _value.l = (jobject) (JNIHandles::resolve_external_guard(_value.l)); 767 } 768 // Re-read the vframe so we can see that it is deoptimized 769 // [ Only need because of assert in update_local() ] 770 _jvf = get_java_vframe(); 771 ((compiledVFrame*)_jvf)->update_local(_type, _index, _value); 772 return; 773 } 774 StackValueCollection *locals = _jvf->locals(); 775 HandleMark hm; 776 777 switch (_type) { 778 case T_INT: locals->set_int_at (_index, _value.i); break; 779 case T_LONG: locals->set_long_at (_index, _value.j); break; 780 case T_FLOAT: locals->set_float_at (_index, _value.f); break; 781 case T_DOUBLE: locals->set_double_at(_index, _value.d); break; 782 case T_OBJECT: { 783 Handle ob_h(Thread::current(), JNIHandles::resolve_external_guard(_value.l)); 784 locals->set_obj_at (_index, ob_h); 785 break; 786 } 787 default: ShouldNotReachHere(); 788 } 789 _jvf->set_locals(locals); 790 } else { 791 if (_jvf->method()->is_native() && _jvf->is_compiled_frame()) { 792 assert(getting_receiver(), "Can only get here when getting receiver"); 793 oop receiver = _jvf->fr().get_native_receiver(); 794 _value.l = JNIHandles::make_local(_calling_thread, receiver); 795 } else { 796 StackValueCollection *locals = _jvf->locals(); 797 798 if (locals->at(_index)->type() == T_CONFLICT) { 799 memset(&_value, 0, sizeof(_value)); 800 _value.l = NULL; 801 return; 802 } 803 804 switch (_type) { 805 case T_INT: _value.i = locals->int_at (_index); break; 806 case T_LONG: _value.j = locals->long_at (_index); break; 807 case T_FLOAT: _value.f = locals->float_at (_index); break; 808 case T_DOUBLE: _value.d = locals->double_at(_index); break; 809 case T_OBJECT: { 810 // Wrap the oop to be returned in a local JNI handle since 811 // oops_do() no longer applies after doit() is finished. 812 oop obj = locals->obj_at(_index)(); 813 _value.l = JNIHandles::make_local(_calling_thread, obj); 814 break; 815 } 816 default: ShouldNotReachHere(); 817 } 818 } 819 } 820 } 821 822 823 bool VM_GetOrSetLocal::allow_nested_vm_operations() const { 824 return true; // May need to deoptimize 825 } 826 827 828 VM_GetReceiver::VM_GetReceiver( 829 JavaThread* thread, JavaThread* caller_thread, jint depth) 830 : VM_GetOrSetLocal(thread, caller_thread, depth, 0) {} 831 832 ///////////////////////////////////////////////////////////////////////////////////////// 833 834 // 835 // class JvmtiSuspendControl - see comments in jvmtiImpl.hpp 836 // 837 838 bool JvmtiSuspendControl::suspend(JavaThread *java_thread) { 839 // external suspend should have caught suspending a thread twice 840 841 // Immediate suspension required for JPDA back-end so JVMTI agent threads do 842 // not deadlock due to later suspension on transitions while holding 843 // raw monitors. Passing true causes the immediate suspension. 844 // java_suspend() will catch threads in the process of exiting 845 // and will ignore them. 846 java_thread->java_suspend(); 847 848 // It would be nice to have the following assertion in all the time, 849 // but it is possible for a racing resume request to have resumed 850 // this thread right after we suspended it. Temporarily enable this 851 // assertion if you are chasing a different kind of bug. 852 // 853 // assert(java_lang_Thread::thread(java_thread->threadObj()) == NULL || 854 // java_thread->is_being_ext_suspended(), "thread is not suspended"); 855 856 if (java_lang_Thread::thread(java_thread->threadObj()) == NULL) { 857 // check again because we can get delayed in java_suspend(): 858 // the thread is in process of exiting. 859 return false; 860 } 861 862 return true; 863 } 864 865 bool JvmtiSuspendControl::resume(JavaThread *java_thread) { 866 // external suspend should have caught resuming a thread twice 867 assert(java_thread->is_being_ext_suspended(), "thread should be suspended"); 868 869 // resume thread 870 { 871 // must always grab Threads_lock, see JVM_SuspendThread 872 MutexLocker ml(Threads_lock); 873 java_thread->java_resume(); 874 } 875 876 return true; 877 } 878 879 880 void JvmtiSuspendControl::print() { 881 #ifndef PRODUCT 882 LogStreamHandle(Trace, jvmti) log_stream; 883 log_stream.print("Suspended Threads: ["); 884 ThreadsListHandle tlh; 885 JavaThreadIterator jti(tlh.list()); 886 for (JavaThread *thread = jti.first(); thread != NULL; thread = jti.next()) { 887 #ifdef JVMTI_TRACE 888 const char *name = JvmtiTrace::safe_get_thread_name(thread); 889 #else 890 const char *name = ""; 891 #endif /*JVMTI_TRACE */ 892 log_stream.print("%s(%c ", name, thread->is_being_ext_suspended() ? 'S' : '_'); 893 if (!thread->has_last_Java_frame()) { 894 log_stream.print("no stack"); 895 } 896 log_stream.print(") "); 897 } 898 log_stream.print_cr("]"); 899 #endif 900 } 901 902 JvmtiDeferredEvent JvmtiDeferredEvent::compiled_method_load_event( 903 nmethod* nm) { 904 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_COMPILED_METHOD_LOAD); 905 event._event_data.compiled_method_load = nm; 906 // Keep the nmethod alive until the ServiceThread can process 907 // this deferred event. 908 nmethodLocker::lock_nmethod(nm); 909 return event; 910 } 911 912 JvmtiDeferredEvent JvmtiDeferredEvent::compiled_method_unload_event( 913 nmethod* nm, jmethodID id, const void* code) { 914 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_COMPILED_METHOD_UNLOAD); 915 event._event_data.compiled_method_unload.nm = nm; 916 event._event_data.compiled_method_unload.method_id = id; 917 event._event_data.compiled_method_unload.code_begin = code; 918 // Keep the nmethod alive until the ServiceThread can process 919 // this deferred event. This will keep the memory for the 920 // generated code from being reused too early. We pass 921 // zombie_ok == true here so that our nmethod that was just 922 // made into a zombie can be locked. 923 nmethodLocker::lock_nmethod(nm, true /* zombie_ok */); 924 return event; 925 } 926 927 JvmtiDeferredEvent JvmtiDeferredEvent::dynamic_code_generated_event( 928 const char* name, const void* code_begin, const void* code_end) { 929 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_DYNAMIC_CODE_GENERATED); 930 // Need to make a copy of the name since we don't know how long 931 // the event poster will keep it around after we enqueue the 932 // deferred event and return. strdup() failure is handled in 933 // the post() routine below. 934 event._event_data.dynamic_code_generated.name = os::strdup(name); 935 event._event_data.dynamic_code_generated.code_begin = code_begin; 936 event._event_data.dynamic_code_generated.code_end = code_end; 937 return event; 938 } 939 940 void JvmtiDeferredEvent::post() { 941 assert(ServiceThread::is_service_thread(Thread::current()), 942 "Service thread must post enqueued events"); 943 switch(_type) { 944 case TYPE_COMPILED_METHOD_LOAD: { 945 nmethod* nm = _event_data.compiled_method_load; 946 JvmtiExport::post_compiled_method_load(nm); 947 // done with the deferred event so unlock the nmethod 948 nmethodLocker::unlock_nmethod(nm); 949 break; 950 } 951 case TYPE_COMPILED_METHOD_UNLOAD: { 952 nmethod* nm = _event_data.compiled_method_unload.nm; 953 JvmtiExport::post_compiled_method_unload( 954 _event_data.compiled_method_unload.method_id, 955 _event_data.compiled_method_unload.code_begin); 956 // done with the deferred event so unlock the nmethod 957 nmethodLocker::unlock_nmethod(nm); 958 break; 959 } 960 case TYPE_DYNAMIC_CODE_GENERATED: { 961 JvmtiExport::post_dynamic_code_generated_internal( 962 // if strdup failed give the event a default name 963 (_event_data.dynamic_code_generated.name == NULL) 964 ? "unknown_code" : _event_data.dynamic_code_generated.name, 965 _event_data.dynamic_code_generated.code_begin, 966 _event_data.dynamic_code_generated.code_end); 967 if (_event_data.dynamic_code_generated.name != NULL) { 968 // release our copy 969 os::free((void *)_event_data.dynamic_code_generated.name); 970 } 971 break; 972 } 973 default: 974 ShouldNotReachHere(); 975 } 976 } 977 978 JvmtiDeferredEventQueue::QueueNode* JvmtiDeferredEventQueue::_queue_tail = NULL; 979 JvmtiDeferredEventQueue::QueueNode* JvmtiDeferredEventQueue::_queue_head = NULL; 980 981 bool JvmtiDeferredEventQueue::has_events() { 982 assert(Service_lock->owned_by_self(), "Must own Service_lock"); 983 return _queue_head != NULL; 984 } 985 986 void JvmtiDeferredEventQueue::enqueue(const JvmtiDeferredEvent& event) { 987 assert(Service_lock->owned_by_self(), "Must own Service_lock"); 988 989 // Events get added to the end of the queue (and are pulled off the front). 990 QueueNode* node = new QueueNode(event); 991 if (_queue_tail == NULL) { 992 _queue_tail = _queue_head = node; 993 } else { 994 assert(_queue_tail->next() == NULL, "Must be the last element in the list"); 995 _queue_tail->set_next(node); 996 _queue_tail = node; 997 } 998 999 Service_lock->notify_all(); 1000 assert((_queue_head == NULL) == (_queue_tail == NULL), 1001 "Inconsistent queue markers"); 1002 } 1003 1004 JvmtiDeferredEvent JvmtiDeferredEventQueue::dequeue() { 1005 assert(Service_lock->owned_by_self(), "Must own Service_lock"); 1006 1007 assert(_queue_head != NULL, "Nothing to dequeue"); 1008 1009 if (_queue_head == NULL) { 1010 // Just in case this happens in product; it shouldn't but let's not crash 1011 return JvmtiDeferredEvent(); 1012 } 1013 1014 QueueNode* node = _queue_head; 1015 _queue_head = _queue_head->next(); 1016 if (_queue_head == NULL) { 1017 _queue_tail = NULL; 1018 } 1019 1020 assert((_queue_head == NULL) == (_queue_tail == NULL), 1021 "Inconsistent queue markers"); 1022 1023 JvmtiDeferredEvent event = node->event(); 1024 delete node; 1025 return event; 1026 }