1 /* 2 * Copyright (c) 2003, 2018, 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/allocation.inline.hpp" 33 #include "memory/resourceArea.hpp" 34 #include "oops/instanceKlass.hpp" 35 #include "oops/oop.inline.hpp" 36 #include "prims/jvmtiAgentThread.hpp" 37 #include "prims/jvmtiEventController.inline.hpp" 38 #include "prims/jvmtiImpl.hpp" 39 #include "prims/jvmtiRedefineClasses.hpp" 40 #include "runtime/atomic.hpp" 41 #include "runtime/deoptimization.hpp" 42 #include "runtime/handles.hpp" 43 #include "runtime/handles.inline.hpp" 44 #include "runtime/interfaceSupport.inline.hpp" 45 #include "runtime/javaCalls.hpp" 46 #include "runtime/os.hpp" 47 #include "runtime/serviceThread.hpp" 48 #include "runtime/signature.hpp" 49 #include "runtime/thread.inline.hpp" 50 #include "runtime/threadSMR.hpp" 51 #include "runtime/vframe.hpp" 52 #include "runtime/vframe_hp.hpp" 53 #include "runtime/vm_operations.hpp" 54 #include "utilities/exceptions.hpp" 55 56 // 57 // class JvmtiAgentThread 58 // 59 // JavaThread used to wrap a thread started by an agent 60 // using the JVMTI method RunAgentThread. 61 // 62 63 JvmtiAgentThread::JvmtiAgentThread(JvmtiEnv* env, jvmtiStartFunction start_fn, const void *start_arg) 64 : JavaThread(start_function_wrapper) { 65 _env = env; 66 _start_fn = start_fn; 67 _start_arg = start_arg; 68 } 69 70 void 71 JvmtiAgentThread::start_function_wrapper(JavaThread *thread, TRAPS) { 72 // It is expected that any Agent threads will be created as 73 // Java Threads. If this is the case, notification of the creation 74 // of the thread is given in JavaThread::thread_main(). 75 assert(thread->is_Java_thread(), "debugger thread should be a Java Thread"); 76 assert(thread == JavaThread::current(), "sanity check"); 77 78 JvmtiAgentThread *dthread = (JvmtiAgentThread *)thread; 79 dthread->call_start_function(); 80 } 81 82 void 83 JvmtiAgentThread::call_start_function() { 84 ThreadToNativeFromVM transition(this); 85 _start_fn(_env->jvmti_external(), jni_environment(), (void*)_start_arg); 86 } 87 88 89 // 90 // class GrowableCache - private methods 91 // 92 93 void GrowableCache::recache() { 94 int len = _elements->length(); 95 96 FREE_C_HEAP_ARRAY(address, _cache); 97 _cache = NEW_C_HEAP_ARRAY(address,len+1, mtInternal); 98 99 for (int i=0; i<len; i++) { 100 _cache[i] = _elements->at(i)->getCacheValue(); 101 // 102 // The cache entry has gone bad. Without a valid frame pointer 103 // value, the entry is useless so we simply delete it in product 104 // mode. The call to remove() will rebuild the cache again 105 // without the bad entry. 106 // 107 if (_cache[i] == NULL) { 108 assert(false, "cannot recache NULL elements"); 109 remove(i); 110 return; 111 } 112 } 113 _cache[len] = NULL; 114 115 _listener_fun(_this_obj,_cache); 116 } 117 118 bool GrowableCache::equals(void* v, GrowableElement *e2) { 119 GrowableElement *e1 = (GrowableElement *) v; 120 assert(e1 != NULL, "e1 != NULL"); 121 assert(e2 != NULL, "e2 != NULL"); 122 123 return e1->equals(e2); 124 } 125 126 // 127 // class GrowableCache - public methods 128 // 129 130 GrowableCache::GrowableCache() { 131 _this_obj = NULL; 132 _listener_fun = NULL; 133 _elements = NULL; 134 _cache = NULL; 135 } 136 137 GrowableCache::~GrowableCache() { 138 clear(); 139 delete _elements; 140 FREE_C_HEAP_ARRAY(address, _cache); 141 } 142 143 void GrowableCache::initialize(void *this_obj, void listener_fun(void *, address*) ) { 144 _this_obj = this_obj; 145 _listener_fun = listener_fun; 146 _elements = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<GrowableElement*>(5,true); 147 recache(); 148 } 149 150 // number of elements in the collection 151 int GrowableCache::length() { 152 return _elements->length(); 153 } 154 155 // get the value of the index element in the collection 156 GrowableElement* GrowableCache::at(int index) { 157 GrowableElement *e = (GrowableElement *) _elements->at(index); 158 assert(e != NULL, "e != NULL"); 159 return e; 160 } 161 162 int GrowableCache::find(GrowableElement* e) { 163 return _elements->find(e, GrowableCache::equals); 164 } 165 166 // append a copy of the element to the end of the collection 167 void GrowableCache::append(GrowableElement* e) { 168 GrowableElement *new_e = e->clone(); 169 _elements->append(new_e); 170 recache(); 171 } 172 173 // insert a copy of the element using lessthan() 174 void GrowableCache::insert(GrowableElement* e) { 175 GrowableElement *new_e = e->clone(); 176 _elements->append(new_e); 177 178 int n = length()-2; 179 for (int i=n; i>=0; i--) { 180 GrowableElement *e1 = _elements->at(i); 181 GrowableElement *e2 = _elements->at(i+1); 182 if (e2->lessThan(e1)) { 183 _elements->at_put(i+1, e1); 184 _elements->at_put(i, e2); 185 } 186 } 187 188 recache(); 189 } 190 191 // remove the element at index 192 void GrowableCache::remove (int index) { 193 GrowableElement *e = _elements->at(index); 194 assert(e != NULL, "e != NULL"); 195 _elements->remove(e); 196 delete e; 197 recache(); 198 } 199 200 // clear out all elements, release all heap space and 201 // let our listener know that things have changed. 202 void GrowableCache::clear() { 203 int len = _elements->length(); 204 for (int i=0; i<len; i++) { 205 delete _elements->at(i); 206 } 207 _elements->clear(); 208 recache(); 209 } 210 211 void GrowableCache::oops_do(OopClosure* f) { 212 int len = _elements->length(); 213 for (int i=0; i<len; i++) { 214 GrowableElement *e = _elements->at(i); 215 e->oops_do(f); 216 } 217 } 218 219 void GrowableCache::metadata_do(void f(Metadata*)) { 220 int len = _elements->length(); 221 for (int i=0; i<len; i++) { 222 GrowableElement *e = _elements->at(i); 223 e->metadata_do(f); 224 } 225 } 226 227 void GrowableCache::gc_epilogue() { 228 int len = _elements->length(); 229 for (int i=0; i<len; i++) { 230 _cache[i] = _elements->at(i)->getCacheValue(); 231 } 232 } 233 234 // 235 // class JvmtiBreakpoint 236 // 237 238 JvmtiBreakpoint::JvmtiBreakpoint() { 239 _method = NULL; 240 _bci = 0; 241 _class_holder = NULL; 242 } 243 244 JvmtiBreakpoint::JvmtiBreakpoint(Method* m_method, jlocation location) { 245 _method = m_method; 246 _class_holder = _method->method_holder()->klass_holder(); 247 #ifdef CHECK_UNHANDLED_OOPS 248 // _class_holder can't be wrapped in a Handle, because JvmtiBreakpoints are 249 // sometimes allocated on the heap. 250 // 251 // The code handling JvmtiBreakpoints allocated on the stack can't be 252 // interrupted by a GC until _class_holder is reachable by the GC via the 253 // oops_do method. 254 Thread::current()->allow_unhandled_oop(&_class_holder); 255 #endif // CHECK_UNHANDLED_OOPS 256 assert(_method != NULL, "_method != NULL"); 257 _bci = (int) location; 258 assert(_bci >= 0, "_bci >= 0"); 259 } 260 261 void JvmtiBreakpoint::copy(JvmtiBreakpoint& bp) { 262 _method = bp._method; 263 _bci = bp._bci; 264 _class_holder = bp._class_holder; 265 } 266 267 bool JvmtiBreakpoint::lessThan(JvmtiBreakpoint& bp) { 268 Unimplemented(); 269 return false; 270 } 271 272 bool JvmtiBreakpoint::equals(JvmtiBreakpoint& bp) { 273 return _method == bp._method 274 && _bci == bp._bci; 275 } 276 277 bool JvmtiBreakpoint::is_valid() { 278 // class loader can be NULL 279 return _method != NULL && 280 _bci >= 0; 281 } 282 283 address JvmtiBreakpoint::getBcp() const { 284 return _method->bcp_from(_bci); 285 } 286 287 void JvmtiBreakpoint::each_method_version_do(method_action meth_act) { 288 ((Method*)_method->*meth_act)(_bci); 289 290 // add/remove breakpoint to/from versions of the method that are EMCP. 291 Thread *thread = Thread::current(); 292 InstanceKlass* ik = _method->method_holder(); 293 Symbol* m_name = _method->name(); 294 Symbol* m_signature = _method->signature(); 295 296 // search previous versions if they exist 297 for (InstanceKlass* pv_node = ik->previous_versions(); 298 pv_node != NULL; 299 pv_node = pv_node->previous_versions()) { 300 Array<Method*>* methods = pv_node->methods(); 301 302 for (int i = methods->length() - 1; i >= 0; i--) { 303 Method* method = methods->at(i); 304 // Only set breakpoints in running EMCP methods. 305 if (method->is_running_emcp() && 306 method->name() == m_name && 307 method->signature() == m_signature) { 308 ResourceMark rm; 309 log_debug(redefine, class, breakpoint) 310 ("%sing breakpoint in %s(%s)", meth_act == &Method::set_breakpoint ? "sett" : "clear", 311 method->name()->as_C_string(), method->signature()->as_C_string()); 312 (method->*meth_act)(_bci); 313 break; 314 } 315 } 316 } 317 } 318 319 void JvmtiBreakpoint::set() { 320 each_method_version_do(&Method::set_breakpoint); 321 } 322 323 void JvmtiBreakpoint::clear() { 324 each_method_version_do(&Method::clear_breakpoint); 325 } 326 327 void JvmtiBreakpoint::print_on(outputStream* out) const { 328 #ifndef PRODUCT 329 ResourceMark rm; 330 const char *class_name = (_method == NULL) ? "NULL" : _method->klass_name()->as_C_string(); 331 const char *method_name = (_method == NULL) ? "NULL" : _method->name()->as_C_string(); 332 out->print("Breakpoint(%s,%s,%d,%p)", class_name, method_name, _bci, getBcp()); 333 #endif 334 } 335 336 337 // 338 // class VM_ChangeBreakpoints 339 // 340 // Modify the Breakpoints data structure at a safepoint 341 // 342 343 void VM_ChangeBreakpoints::doit() { 344 switch (_operation) { 345 case SET_BREAKPOINT: 346 _breakpoints->set_at_safepoint(*_bp); 347 break; 348 case CLEAR_BREAKPOINT: 349 _breakpoints->clear_at_safepoint(*_bp); 350 break; 351 default: 352 assert(false, "Unknown operation"); 353 } 354 } 355 356 void VM_ChangeBreakpoints::oops_do(OopClosure* f) { 357 // The JvmtiBreakpoints in _breakpoints will be visited via 358 // JvmtiExport::oops_do. 359 if (_bp != NULL) { 360 _bp->oops_do(f); 361 } 362 } 363 364 void VM_ChangeBreakpoints::metadata_do(void f(Metadata*)) { 365 // Walk metadata in breakpoints to keep from being deallocated with RedefineClasses 366 if (_bp != NULL) { 367 _bp->metadata_do(f); 368 } 369 } 370 371 // 372 // class JvmtiBreakpoints 373 // 374 // a JVMTI internal collection of JvmtiBreakpoint 375 // 376 377 JvmtiBreakpoints::JvmtiBreakpoints(void listener_fun(void *,address *)) { 378 _bps.initialize(this,listener_fun); 379 } 380 381 JvmtiBreakpoints:: ~JvmtiBreakpoints() {} 382 383 void JvmtiBreakpoints::oops_do(OopClosure* f) { 384 _bps.oops_do(f); 385 } 386 387 void JvmtiBreakpoints::metadata_do(void f(Metadata*)) { 388 _bps.metadata_do(f); 389 } 390 391 void JvmtiBreakpoints::gc_epilogue() { 392 _bps.gc_epilogue(); 393 } 394 395 void JvmtiBreakpoints::print() { 396 #ifndef PRODUCT 397 LogTarget(Trace, jvmti) log; 398 LogStream log_stream(log); 399 400 int n = _bps.length(); 401 for (int i=0; i<n; i++) { 402 JvmtiBreakpoint& bp = _bps.at(i); 403 log_stream.print("%d: ", i); 404 bp.print_on(&log_stream); 405 log_stream.cr(); 406 } 407 #endif 408 } 409 410 411 void JvmtiBreakpoints::set_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.append(bp); 417 bp.set(); 418 } 419 } 420 421 void JvmtiBreakpoints::clear_at_safepoint(JvmtiBreakpoint& bp) { 422 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint"); 423 424 int i = _bps.find(bp); 425 if (i != -1) { 426 _bps.remove(i); 427 bp.clear(); 428 } 429 } 430 431 int JvmtiBreakpoints::length() { return _bps.length(); } 432 433 int JvmtiBreakpoints::set(JvmtiBreakpoint& bp) { 434 if ( _bps.find(bp) != -1) { 435 return JVMTI_ERROR_DUPLICATE; 436 } 437 VM_ChangeBreakpoints set_breakpoint(VM_ChangeBreakpoints::SET_BREAKPOINT, &bp); 438 VMThread::execute(&set_breakpoint); 439 return JVMTI_ERROR_NONE; 440 } 441 442 int JvmtiBreakpoints::clear(JvmtiBreakpoint& bp) { 443 if ( _bps.find(bp) == -1) { 444 return JVMTI_ERROR_NOT_FOUND; 445 } 446 447 VM_ChangeBreakpoints clear_breakpoint(VM_ChangeBreakpoints::CLEAR_BREAKPOINT, &bp); 448 VMThread::execute(&clear_breakpoint); 449 return JVMTI_ERROR_NONE; 450 } 451 452 void JvmtiBreakpoints::clearall_in_class_at_safepoint(Klass* klass) { 453 bool changed = true; 454 // We are going to run thru the list of bkpts 455 // and delete some. This deletion probably alters 456 // the list in some implementation defined way such 457 // that when we delete entry i, the next entry might 458 // no longer be at i+1. To be safe, each time we delete 459 // an entry, we'll just start again from the beginning. 460 // We'll stop when we make a pass thru the whole list without 461 // deleting anything. 462 while (changed) { 463 int len = _bps.length(); 464 changed = false; 465 for (int i = 0; i < len; i++) { 466 JvmtiBreakpoint& bp = _bps.at(i); 467 if (bp.method()->method_holder() == klass) { 468 bp.clear(); 469 _bps.remove(i); 470 // This changed 'i' so we have to start over. 471 changed = true; 472 break; 473 } 474 } 475 } 476 } 477 478 // 479 // class JvmtiCurrentBreakpoints 480 // 481 482 JvmtiBreakpoints *JvmtiCurrentBreakpoints::_jvmti_breakpoints = NULL; 483 address * JvmtiCurrentBreakpoints::_breakpoint_list = NULL; 484 485 486 JvmtiBreakpoints& JvmtiCurrentBreakpoints::get_jvmti_breakpoints() { 487 if (_jvmti_breakpoints != NULL) return (*_jvmti_breakpoints); 488 _jvmti_breakpoints = new JvmtiBreakpoints(listener_fun); 489 assert(_jvmti_breakpoints != NULL, "_jvmti_breakpoints != NULL"); 490 return (*_jvmti_breakpoints); 491 } 492 493 void JvmtiCurrentBreakpoints::listener_fun(void *this_obj, address *cache) { 494 JvmtiBreakpoints *this_jvmti = (JvmtiBreakpoints *) this_obj; 495 assert(this_jvmti != NULL, "this_jvmti != NULL"); 496 497 debug_only(int n = this_jvmti->length();); 498 assert(cache[n] == NULL, "cache must be NULL terminated"); 499 500 set_breakpoint_list(cache); 501 } 502 503 504 void JvmtiCurrentBreakpoints::oops_do(OopClosure* f) { 505 if (_jvmti_breakpoints != NULL) { 506 _jvmti_breakpoints->oops_do(f); 507 } 508 } 509 510 void JvmtiCurrentBreakpoints::metadata_do(void f(Metadata*)) { 511 if (_jvmti_breakpoints != NULL) { 512 _jvmti_breakpoints->metadata_do(f); 513 } 514 } 515 516 void JvmtiCurrentBreakpoints::gc_epilogue() { 517 if (_jvmti_breakpoints != NULL) { 518 _jvmti_breakpoints->gc_epilogue(); 519 } 520 } 521 522 /////////////////////////////////////////////////////////////// 523 // 524 // class VM_GetOrSetLocal 525 // 526 527 // Constructor for non-object getter 528 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, jint depth, jint index, BasicType type) 529 : _thread(thread) 530 , _calling_thread(NULL) 531 , _depth(depth) 532 , _index(index) 533 , _type(type) 534 , _set(false) 535 , _jvf(NULL) 536 , _result(JVMTI_ERROR_NONE) 537 { 538 } 539 540 // Constructor for object or non-object setter 541 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, jint depth, jint index, BasicType type, jvalue value) 542 : _thread(thread) 543 , _calling_thread(NULL) 544 , _depth(depth) 545 , _index(index) 546 , _type(type) 547 , _value(value) 548 , _set(true) 549 , _jvf(NULL) 550 , _result(JVMTI_ERROR_NONE) 551 { 552 } 553 554 // Constructor for object getter 555 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, JavaThread* calling_thread, jint depth, int index) 556 : _thread(thread) 557 , _calling_thread(calling_thread) 558 , _depth(depth) 559 , _index(index) 560 , _type(T_OBJECT) 561 , _set(false) 562 , _jvf(NULL) 563 , _result(JVMTI_ERROR_NONE) 564 { 565 } 566 567 vframe *VM_GetOrSetLocal::get_vframe() { 568 if (!_thread->has_last_Java_frame()) { 569 return NULL; 570 } 571 RegisterMap reg_map(_thread); 572 vframe *vf = _thread->last_java_vframe(®_map); 573 int d = 0; 574 while ((vf != NULL) && (d < _depth)) { 575 vf = vf->java_sender(); 576 d++; 577 } 578 return vf; 579 } 580 581 javaVFrame *VM_GetOrSetLocal::get_java_vframe() { 582 vframe* vf = get_vframe(); 583 if (vf == NULL) { 584 _result = JVMTI_ERROR_NO_MORE_FRAMES; 585 return NULL; 586 } 587 javaVFrame *jvf = (javaVFrame*)vf; 588 589 if (!vf->is_java_frame()) { 590 _result = JVMTI_ERROR_OPAQUE_FRAME; 591 return NULL; 592 } 593 return jvf; 594 } 595 596 // Check that the klass is assignable to a type with the given signature. 597 // Another solution could be to use the function Klass::is_subtype_of(type). 598 // But the type class can be forced to load/initialize eagerly in such a case. 599 // This may cause unexpected consequences like CFLH or class-init JVMTI events. 600 // It is better to avoid such a behavior. 601 bool VM_GetOrSetLocal::is_assignable(const char* ty_sign, Klass* klass, Thread* thread) { 602 assert(ty_sign != NULL, "type signature must not be NULL"); 603 assert(thread != NULL, "thread must not be NULL"); 604 assert(klass != NULL, "klass must not be NULL"); 605 606 int len = (int) strlen(ty_sign); 607 if (ty_sign[0] == 'L' && ty_sign[len-1] == ';') { // Need pure class/interface name 608 ty_sign++; 609 len -= 2; 610 } 611 TempNewSymbol ty_sym = SymbolTable::new_symbol(ty_sign, len, thread); 612 if (klass->name() == ty_sym) { 613 return true; 614 } 615 // Compare primary supers 616 int super_depth = klass->super_depth(); 617 int idx; 618 for (idx = 0; idx < super_depth; idx++) { 619 if (klass->primary_super_of_depth(idx)->name() == ty_sym) { 620 return true; 621 } 622 } 623 // Compare secondary supers 624 Array<Klass*>* sec_supers = klass->secondary_supers(); 625 for (idx = 0; idx < sec_supers->length(); idx++) { 626 if (((Klass*) sec_supers->at(idx))->name() == ty_sym) { 627 return true; 628 } 629 } 630 return false; 631 } 632 633 // Checks error conditions: 634 // JVMTI_ERROR_INVALID_SLOT 635 // JVMTI_ERROR_TYPE_MISMATCH 636 // Returns: 'true' - everything is Ok, 'false' - error code 637 638 bool VM_GetOrSetLocal::check_slot_type(javaVFrame* jvf) { 639 Method* method_oop = jvf->method(); 640 if (!method_oop->has_localvariable_table()) { 641 // Just to check index boundaries 642 jint extra_slot = (_type == T_LONG || _type == T_DOUBLE) ? 1 : 0; 643 if (_index < 0 || _index + extra_slot >= method_oop->max_locals()) { 644 _result = JVMTI_ERROR_INVALID_SLOT; 645 return false; 646 } 647 return true; 648 } 649 650 jint num_entries = method_oop->localvariable_table_length(); 651 if (num_entries == 0) { 652 _result = JVMTI_ERROR_INVALID_SLOT; 653 return false; // There are no slots 654 } 655 int signature_idx = -1; 656 int vf_bci = jvf->bci(); 657 LocalVariableTableElement* table = method_oop->localvariable_table_start(); 658 for (int i = 0; i < num_entries; i++) { 659 int start_bci = table[i].start_bci; 660 int end_bci = start_bci + table[i].length; 661 662 // Here we assume that locations of LVT entries 663 // with the same slot number cannot be overlapped 664 if (_index == (jint) table[i].slot && start_bci <= vf_bci && vf_bci <= end_bci) { 665 signature_idx = (int) table[i].descriptor_cp_index; 666 break; 667 } 668 } 669 if (signature_idx == -1) { 670 _result = JVMTI_ERROR_INVALID_SLOT; 671 return false; // Incorrect slot index 672 } 673 Symbol* sign_sym = method_oop->constants()->symbol_at(signature_idx); 674 const char* signature = (const char *) sign_sym->as_utf8(); 675 BasicType slot_type = char2type(signature[0]); 676 677 switch (slot_type) { 678 case T_BYTE: 679 case T_SHORT: 680 case T_CHAR: 681 case T_BOOLEAN: 682 slot_type = T_INT; 683 break; 684 case T_ARRAY: 685 slot_type = T_OBJECT; 686 break; 687 default: 688 break; 689 }; 690 if (_type != slot_type) { 691 _result = JVMTI_ERROR_TYPE_MISMATCH; 692 return false; 693 } 694 695 jobject jobj = _value.l; 696 if (_set && slot_type == T_OBJECT && jobj != NULL) { // NULL reference is allowed 697 // Check that the jobject class matches the return type signature. 698 JavaThread* cur_thread = JavaThread::current(); 699 HandleMark hm(cur_thread); 700 701 Handle obj(cur_thread, JNIHandles::resolve_external_guard(jobj)); 702 NULL_CHECK(obj, (_result = JVMTI_ERROR_INVALID_OBJECT, false)); 703 Klass* ob_k = obj->klass(); 704 NULL_CHECK(ob_k, (_result = JVMTI_ERROR_INVALID_OBJECT, false)); 705 706 if (!is_assignable(signature, ob_k, cur_thread)) { 707 _result = JVMTI_ERROR_TYPE_MISMATCH; 708 return false; 709 } 710 } 711 return true; 712 } 713 714 static bool can_be_deoptimized(vframe* vf) { 715 return (vf->is_compiled_frame() && vf->fr().can_be_deoptimized()); 716 } 717 718 bool VM_GetOrSetLocal::doit_prologue() { 719 _jvf = get_java_vframe(); 720 NULL_CHECK(_jvf, false); 721 722 if (_jvf->method()->is_native()) { 723 if (getting_receiver() && !_jvf->method()->is_static()) { 724 return true; 725 } else { 726 _result = JVMTI_ERROR_OPAQUE_FRAME; 727 return false; 728 } 729 } 730 731 if (!check_slot_type(_jvf)) { 732 return false; 733 } 734 return true; 735 } 736 737 void VM_GetOrSetLocal::doit() { 738 InterpreterOopMap oop_mask; 739 _jvf->method()->mask_for(_jvf->bci(), &oop_mask); 740 if (oop_mask.is_dead(_index)) { 741 // The local can be invalid and uninitialized in the scope of current bci 742 _result = JVMTI_ERROR_INVALID_SLOT; 743 return; 744 } 745 if (_set) { 746 // Force deoptimization of frame if compiled because it's 747 // possible the compiler emitted some locals as constant values, 748 // meaning they are not mutable. 749 if (can_be_deoptimized(_jvf)) { 750 751 // Schedule deoptimization so that eventually the local 752 // update will be written to an interpreter frame. 753 Deoptimization::deoptimize_frame(_jvf->thread(), _jvf->fr().id()); 754 755 // Now store a new value for the local which will be applied 756 // once deoptimization occurs. Note however that while this 757 // write is deferred until deoptimization actually happens 758 // can vframe created after this point will have its locals 759 // reflecting this update so as far as anyone can see the 760 // write has already taken place. 761 762 // If we are updating an oop then get the oop from the handle 763 // since the handle will be long gone by the time the deopt 764 // happens. The oop stored in the deferred local will be 765 // gc'd on its own. 766 if (_type == T_OBJECT) { 767 _value.l = (jobject) (JNIHandles::resolve_external_guard(_value.l)); 768 } 769 // Re-read the vframe so we can see that it is deoptimized 770 // [ Only need because of assert in update_local() ] 771 _jvf = get_java_vframe(); 772 ((compiledVFrame*)_jvf)->update_local(_type, _index, _value); 773 return; 774 } 775 StackValueCollection *locals = _jvf->locals(); 776 HandleMark hm; 777 778 switch (_type) { 779 case T_INT: locals->set_int_at (_index, _value.i); break; 780 case T_LONG: locals->set_long_at (_index, _value.j); break; 781 case T_FLOAT: locals->set_float_at (_index, _value.f); break; 782 case T_DOUBLE: locals->set_double_at(_index, _value.d); break; 783 case T_OBJECT: { 784 Handle ob_h(Thread::current(), JNIHandles::resolve_external_guard(_value.l)); 785 locals->set_obj_at (_index, ob_h); 786 break; 787 } 788 default: ShouldNotReachHere(); 789 } 790 _jvf->set_locals(locals); 791 } else { 792 if (_jvf->method()->is_native() && _jvf->is_compiled_frame()) { 793 assert(getting_receiver(), "Can only get here when getting receiver"); 794 oop receiver = _jvf->fr().get_native_receiver(); 795 _value.l = JNIHandles::make_local(_calling_thread, receiver); 796 } else { 797 StackValueCollection *locals = _jvf->locals(); 798 799 if (locals->at(_index)->type() == T_CONFLICT) { 800 memset(&_value, 0, sizeof(_value)); 801 _value.l = NULL; 802 return; 803 } 804 805 switch (_type) { 806 case T_INT: _value.i = locals->int_at (_index); break; 807 case T_LONG: _value.j = locals->long_at (_index); break; 808 case T_FLOAT: _value.f = locals->float_at (_index); break; 809 case T_DOUBLE: _value.d = locals->double_at(_index); break; 810 case T_OBJECT: { 811 // Wrap the oop to be returned in a local JNI handle since 812 // oops_do() no longer applies after doit() is finished. 813 oop obj = locals->obj_at(_index)(); 814 _value.l = JNIHandles::make_local(_calling_thread, obj); 815 break; 816 } 817 default: ShouldNotReachHere(); 818 } 819 } 820 } 821 } 822 823 824 bool VM_GetOrSetLocal::allow_nested_vm_operations() const { 825 return true; // May need to deoptimize 826 } 827 828 829 VM_GetReceiver::VM_GetReceiver( 830 JavaThread* thread, JavaThread* caller_thread, jint depth) 831 : VM_GetOrSetLocal(thread, caller_thread, depth, 0) {} 832 833 ///////////////////////////////////////////////////////////////////////////////////////// 834 835 // 836 // class JvmtiSuspendControl - see comments in jvmtiImpl.hpp 837 // 838 839 bool JvmtiSuspendControl::suspend(JavaThread *java_thread) { 840 // external suspend should have caught suspending a thread twice 841 842 // Immediate suspension required for JPDA back-end so JVMTI agent threads do 843 // not deadlock due to later suspension on transitions while holding 844 // raw monitors. Passing true causes the immediate suspension. 845 // java_suspend() will catch threads in the process of exiting 846 // and will ignore them. 847 java_thread->java_suspend(); 848 849 // It would be nice to have the following assertion in all the time, 850 // but it is possible for a racing resume request to have resumed 851 // this thread right after we suspended it. Temporarily enable this 852 // assertion if you are chasing a different kind of bug. 853 // 854 // assert(java_lang_Thread::thread(java_thread->threadObj()) == NULL || 855 // java_thread->is_being_ext_suspended(), "thread is not suspended"); 856 857 if (java_lang_Thread::thread(java_thread->threadObj()) == NULL) { 858 // check again because we can get delayed in java_suspend(): 859 // the thread is in process of exiting. 860 return false; 861 } 862 863 return true; 864 } 865 866 bool JvmtiSuspendControl::resume(JavaThread *java_thread) { 867 // external suspend should have caught resuming a thread twice 868 assert(java_thread->is_being_ext_suspended(), "thread should be suspended"); 869 870 // resume thread 871 { 872 // must always grab Threads_lock, see JVM_SuspendThread 873 MutexLocker ml(Threads_lock); 874 java_thread->java_resume(); 875 } 876 877 return true; 878 } 879 880 881 void JvmtiSuspendControl::print() { 882 #ifndef PRODUCT 883 LogStreamHandle(Trace, jvmti) log_stream; 884 log_stream.print("Suspended Threads: ["); 885 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *thread = jtiwh.next(); ) { 886 #ifdef JVMTI_TRACE 887 const char *name = JvmtiTrace::safe_get_thread_name(thread); 888 #else 889 const char *name = ""; 890 #endif /*JVMTI_TRACE */ 891 log_stream.print("%s(%c ", name, thread->is_being_ext_suspended() ? 'S' : '_'); 892 if (!thread->has_last_Java_frame()) { 893 log_stream.print("no stack"); 894 } 895 log_stream.print(") "); 896 } 897 log_stream.print_cr("]"); 898 #endif 899 } 900 901 JvmtiDeferredEvent JvmtiDeferredEvent::compiled_method_load_event( 902 nmethod* nm) { 903 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_COMPILED_METHOD_LOAD); 904 event._event_data.compiled_method_load = nm; 905 // Keep the nmethod alive until the ServiceThread can process 906 // this deferred event. 907 nmethodLocker::lock_nmethod(nm); 908 return event; 909 } 910 911 JvmtiDeferredEvent JvmtiDeferredEvent::compiled_method_unload_event( 912 nmethod* nm, jmethodID id, const void* code) { 913 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_COMPILED_METHOD_UNLOAD); 914 event._event_data.compiled_method_unload.nm = nm; 915 event._event_data.compiled_method_unload.method_id = id; 916 event._event_data.compiled_method_unload.code_begin = code; 917 // Keep the nmethod alive until the ServiceThread can process 918 // this deferred event. This will keep the memory for the 919 // generated code from being reused too early. We pass 920 // zombie_ok == true here so that our nmethod that was just 921 // made into a zombie can be locked. 922 nmethodLocker::lock_nmethod(nm, true /* zombie_ok */); 923 return event; 924 } 925 926 JvmtiDeferredEvent JvmtiDeferredEvent::dynamic_code_generated_event( 927 const char* name, const void* code_begin, const void* code_end) { 928 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_DYNAMIC_CODE_GENERATED); 929 // Need to make a copy of the name since we don't know how long 930 // the event poster will keep it around after we enqueue the 931 // deferred event and return. strdup() failure is handled in 932 // the post() routine below. 933 event._event_data.dynamic_code_generated.name = os::strdup(name); 934 event._event_data.dynamic_code_generated.code_begin = code_begin; 935 event._event_data.dynamic_code_generated.code_end = code_end; 936 return event; 937 } 938 939 void JvmtiDeferredEvent::post() { 940 assert(ServiceThread::is_service_thread(Thread::current()), 941 "Service thread must post enqueued events"); 942 switch(_type) { 943 case TYPE_COMPILED_METHOD_LOAD: { 944 nmethod* nm = _event_data.compiled_method_load; 945 JvmtiExport::post_compiled_method_load(nm); 946 // done with the deferred event so unlock the nmethod 947 nmethodLocker::unlock_nmethod(nm); 948 break; 949 } 950 case TYPE_COMPILED_METHOD_UNLOAD: { 951 nmethod* nm = _event_data.compiled_method_unload.nm; 952 JvmtiExport::post_compiled_method_unload( 953 _event_data.compiled_method_unload.method_id, 954 _event_data.compiled_method_unload.code_begin); 955 // done with the deferred event so unlock the nmethod 956 nmethodLocker::unlock_nmethod(nm); 957 break; 958 } 959 case TYPE_DYNAMIC_CODE_GENERATED: { 960 JvmtiExport::post_dynamic_code_generated_internal( 961 // if strdup failed give the event a default name 962 (_event_data.dynamic_code_generated.name == NULL) 963 ? "unknown_code" : _event_data.dynamic_code_generated.name, 964 _event_data.dynamic_code_generated.code_begin, 965 _event_data.dynamic_code_generated.code_end); 966 if (_event_data.dynamic_code_generated.name != NULL) { 967 // release our copy 968 os::free((void *)_event_data.dynamic_code_generated.name); 969 } 970 break; 971 } 972 default: 973 ShouldNotReachHere(); 974 } 975 } 976 977 JvmtiDeferredEventQueue::QueueNode* JvmtiDeferredEventQueue::_queue_tail = NULL; 978 JvmtiDeferredEventQueue::QueueNode* JvmtiDeferredEventQueue::_queue_head = NULL; 979 980 bool JvmtiDeferredEventQueue::has_events() { 981 assert(Service_lock->owned_by_self(), "Must own Service_lock"); 982 return _queue_head != NULL; 983 } 984 985 void JvmtiDeferredEventQueue::enqueue(const JvmtiDeferredEvent& event) { 986 assert(Service_lock->owned_by_self(), "Must own Service_lock"); 987 988 // Events get added to the end of the queue (and are pulled off the front). 989 QueueNode* node = new QueueNode(event); 990 if (_queue_tail == NULL) { 991 _queue_tail = _queue_head = node; 992 } else { 993 assert(_queue_tail->next() == NULL, "Must be the last element in the list"); 994 _queue_tail->set_next(node); 995 _queue_tail = node; 996 } 997 998 Service_lock->notify_all(); 999 assert((_queue_head == NULL) == (_queue_tail == NULL), 1000 "Inconsistent queue markers"); 1001 } 1002 1003 JvmtiDeferredEvent JvmtiDeferredEventQueue::dequeue() { 1004 assert(Service_lock->owned_by_self(), "Must own Service_lock"); 1005 1006 assert(_queue_head != NULL, "Nothing to dequeue"); 1007 1008 if (_queue_head == NULL) { 1009 // Just in case this happens in product; it shouldn't but let's not crash 1010 return JvmtiDeferredEvent(); 1011 } 1012 1013 QueueNode* node = _queue_head; 1014 _queue_head = _queue_head->next(); 1015 if (_queue_head == NULL) { 1016 _queue_tail = NULL; 1017 } 1018 1019 assert((_queue_head == NULL) == (_queue_tail == NULL), 1020 "Inconsistent queue markers"); 1021 1022 JvmtiDeferredEvent event = node->event(); 1023 delete node; 1024 return event; 1025 }