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