1 /* 2 * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "classfile/systemDictionary.hpp" 27 #include "interpreter/interpreter.hpp" 28 #include "jvmtifiles/jvmtiEnv.hpp" 29 #include "memory/resourceArea.hpp" 30 #include "oops/instanceKlass.hpp" 31 #include "prims/jvmtiAgentThread.hpp" 32 #include "prims/jvmtiEventController.inline.hpp" 33 #include "prims/jvmtiImpl.hpp" 34 #include "prims/jvmtiRedefineClasses.hpp" 35 #include "runtime/atomic.hpp" 36 #include "runtime/deoptimization.hpp" 37 #include "runtime/handles.hpp" 38 #include "runtime/handles.inline.hpp" 39 #include "runtime/interfaceSupport.hpp" 40 #include "runtime/javaCalls.hpp" 41 #include "runtime/os.hpp" 42 #include "runtime/serviceThread.hpp" 43 #include "runtime/signature.hpp" 44 #include "runtime/thread.inline.hpp" 45 #include "runtime/vframe.hpp" 46 #include "runtime/vframe_hp.hpp" 47 #include "runtime/vm_operations.hpp" 48 #include "utilities/exceptions.hpp" 49 50 // 51 // class JvmtiAgentThread 52 // 53 // JavaThread used to wrap a thread started by an agent 54 // using the JVMTI method RunAgentThread. 55 // 56 57 JvmtiAgentThread::JvmtiAgentThread(JvmtiEnv* env, jvmtiStartFunction start_fn, const void *start_arg) 58 : JavaThread(start_function_wrapper) { 59 _env = env; 60 _start_fn = start_fn; 61 _start_arg = start_arg; 62 } 63 64 void 65 JvmtiAgentThread::start_function_wrapper(JavaThread *thread, TRAPS) { 66 // It is expected that any Agent threads will be created as 67 // Java Threads. If this is the case, notification of the creation 68 // of the thread is given in JavaThread::thread_main(). 69 assert(thread->is_Java_thread(), "debugger thread should be a Java Thread"); 70 assert(thread == JavaThread::current(), "sanity check"); 71 72 JvmtiAgentThread *dthread = (JvmtiAgentThread *)thread; 73 dthread->call_start_function(); 74 } 75 76 void 77 JvmtiAgentThread::call_start_function() { 78 ThreadToNativeFromVM transition(this); 79 _start_fn(_env->jvmti_external(), jni_environment(), (void*)_start_arg); 80 } 81 82 83 // 84 // class GrowableCache - private methods 85 // 86 87 void GrowableCache::recache() { 88 int len = _elements->length(); 89 90 FREE_C_HEAP_ARRAY(address, _cache, mtInternal); 91 _cache = NEW_C_HEAP_ARRAY(address,len+1, mtInternal); 92 93 for (int i=0; i<len; i++) { 94 _cache[i] = _elements->at(i)->getCacheValue(); 95 // 96 // The cache entry has gone bad. Without a valid frame pointer 97 // value, the entry is useless so we simply delete it in product 98 // mode. The call to remove() will rebuild the cache again 99 // without the bad entry. 100 // 101 if (_cache[i] == NULL) { 102 assert(false, "cannot recache NULL elements"); 103 remove(i); 104 return; 105 } 106 } 107 _cache[len] = NULL; 108 109 _listener_fun(_this_obj,_cache); 110 } 111 112 bool GrowableCache::equals(void* v, GrowableElement *e2) { 113 GrowableElement *e1 = (GrowableElement *) v; 114 assert(e1 != NULL, "e1 != NULL"); 115 assert(e2 != NULL, "e2 != NULL"); 116 117 return e1->equals(e2); 118 } 119 120 // 121 // class GrowableCache - public methods 122 // 123 124 GrowableCache::GrowableCache() { 125 _this_obj = NULL; 126 _listener_fun = NULL; 127 _elements = NULL; 128 _cache = NULL; 129 } 130 131 GrowableCache::~GrowableCache() { 132 clear(); 133 delete _elements; 134 FREE_C_HEAP_ARRAY(address, _cache, mtInternal); 135 } 136 137 void GrowableCache::initialize(void *this_obj, void listener_fun(void *, address*) ) { 138 _this_obj = this_obj; 139 _listener_fun = listener_fun; 140 _elements = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<GrowableElement*>(5,true); 141 recache(); 142 } 143 144 // number of elements in the collection 145 int GrowableCache::length() { 146 return _elements->length(); 147 } 148 149 // get the value of the index element in the collection 150 GrowableElement* GrowableCache::at(int index) { 151 GrowableElement *e = (GrowableElement *) _elements->at(index); 152 assert(e != NULL, "e != NULL"); 153 return e; 154 } 155 156 int GrowableCache::find(GrowableElement* e) { 157 return _elements->find(e, GrowableCache::equals); 158 } 159 160 // append a copy of the element to the end of the collection 161 void GrowableCache::append(GrowableElement* e) { 162 GrowableElement *new_e = e->clone(); 163 _elements->append(new_e); 164 recache(); 165 } 166 167 // insert a copy of the element using lessthan() 168 void GrowableCache::insert(GrowableElement* e) { 169 GrowableElement *new_e = e->clone(); 170 _elements->append(new_e); 171 172 int n = length()-2; 173 for (int i=n; i>=0; i--) { 174 GrowableElement *e1 = _elements->at(i); 175 GrowableElement *e2 = _elements->at(i+1); 176 if (e2->lessThan(e1)) { 177 _elements->at_put(i+1, e1); 178 _elements->at_put(i, e2); 179 } 180 } 181 182 recache(); 183 } 184 185 // remove the element at index 186 void GrowableCache::remove (int index) { 187 GrowableElement *e = _elements->at(index); 188 assert(e != NULL, "e != NULL"); 189 _elements->remove(e); 190 delete e; 191 recache(); 192 } 193 194 // clear out all elements, release all heap space and 195 // let our listener know that things have changed. 196 void GrowableCache::clear() { 197 int len = _elements->length(); 198 for (int i=0; i<len; i++) { 199 delete _elements->at(i); 200 } 201 _elements->clear(); 202 recache(); 203 } 204 205 void GrowableCache::oops_do(OopClosure* f) { 206 int len = _elements->length(); 207 for (int i=0; i<len; i++) { 208 GrowableElement *e = _elements->at(i); 209 e->oops_do(f); 210 } 211 } 212 213 void GrowableCache::gc_epilogue() { 214 int len = _elements->length(); 215 for (int i=0; i<len; i++) { 216 _cache[i] = _elements->at(i)->getCacheValue(); 217 } 218 } 219 220 // 221 // class JvmtiBreakpoint 222 // 223 224 JvmtiBreakpoint::JvmtiBreakpoint() { 225 _method = NULL; 226 _bci = 0; 227 _class_loader = NULL; 228 #ifdef CHECK_UNHANDLED_OOPS 229 // This one is always allocated with new, but check it just in case. 230 Thread *thread = Thread::current(); 231 if (thread->is_in_stack((address)&_method)) { 232 thread->allow_unhandled_oop((oop*)&_method); 233 } 234 #endif // CHECK_UNHANDLED_OOPS 235 } 236 237 JvmtiBreakpoint::JvmtiBreakpoint(Method* m_method, jlocation location) { 238 _method = m_method; 239 _class_loader = _method->method_holder()->class_loader_data()->class_loader(); 240 assert(_method != NULL, "_method != NULL"); 241 _bci = (int) location; 242 assert(_bci >= 0, "_bci >= 0"); 243 } 244 245 void JvmtiBreakpoint::copy(JvmtiBreakpoint& bp) { 246 _method = bp._method; 247 _bci = bp._bci; 248 _class_loader = bp._class_loader; 249 } 250 251 bool JvmtiBreakpoint::lessThan(JvmtiBreakpoint& bp) { 252 Unimplemented(); 253 return false; 254 } 255 256 bool JvmtiBreakpoint::equals(JvmtiBreakpoint& bp) { 257 return _method == bp._method 258 && _bci == bp._bci; 259 } 260 261 bool JvmtiBreakpoint::is_valid() { 262 // class loader can be NULL 263 return _method != NULL && 264 _bci >= 0; 265 } 266 267 address JvmtiBreakpoint::getBcp() { 268 return _method->bcp_from(_bci); 269 } 270 271 void JvmtiBreakpoint::each_method_version_do(method_action meth_act) { 272 ((Method*)_method->*meth_act)(_bci); 273 274 // add/remove breakpoint to/from versions of the method that 275 // are EMCP. Directly or transitively obsolete methods are 276 // not saved in the PreviousVersionInfo. 277 Thread *thread = Thread::current(); 278 instanceKlassHandle ikh = instanceKlassHandle(thread, _method->method_holder()); 279 Symbol* m_name = _method->name(); 280 Symbol* m_signature = _method->signature(); 281 282 { 283 ResourceMark rm(thread); 284 // PreviousVersionInfo objects returned via PreviousVersionWalker 285 // contain a GrowableArray of handles. We have to clean up the 286 // GrowableArray _after_ the PreviousVersionWalker destructor 287 // has destroyed the handles. 288 { 289 // search previous versions if they exist 290 PreviousVersionWalker pvw((InstanceKlass *)ikh()); 291 for (PreviousVersionInfo * pv_info = pvw.next_previous_version(); 292 pv_info != NULL; pv_info = pvw.next_previous_version()) { 293 GrowableArray<methodHandle>* methods = 294 pv_info->prev_EMCP_method_handles(); 295 296 if (methods == NULL) { 297 // We have run into a PreviousVersion generation where 298 // all methods were made obsolete during that generation's 299 // RedefineClasses() operation. At the time of that 300 // operation, all EMCP methods were flushed so we don't 301 // have to go back any further. 302 // 303 // A NULL methods array is different than an empty methods 304 // array. We cannot infer any optimizations about older 305 // generations from an empty methods array for the current 306 // generation. 307 break; 308 } 309 310 for (int i = methods->length() - 1; i >= 0; i--) { 311 methodHandle method = methods->at(i); 312 // obsolete methods that are running are not deleted from 313 // previous version array, but they are skipped here. 314 if (!method->is_obsolete() && 315 method->name() == m_name && 316 method->signature() == m_signature) { 317 RC_TRACE(0x00000800, ("%sing breakpoint in %s(%s)", 318 meth_act == &Method::set_breakpoint ? "sett" : "clear", 319 method->name()->as_C_string(), 320 method->signature()->as_C_string())); 321 322 ((Method*)method()->*meth_act)(_bci); 323 break; 324 } 325 } 326 } 327 } // pvw is cleaned up 328 } // rm is cleaned up 329 } 330 331 void JvmtiBreakpoint::set() { 332 each_method_version_do(&Method::set_breakpoint); 333 } 334 335 void JvmtiBreakpoint::clear() { 336 each_method_version_do(&Method::clear_breakpoint); 337 } 338 339 void JvmtiBreakpoint::print() { 340 #ifndef PRODUCT 341 const char *class_name = (_method == NULL) ? "NULL" : _method->klass_name()->as_C_string(); 342 const char *method_name = (_method == NULL) ? "NULL" : _method->name()->as_C_string(); 343 344 tty->print("Breakpoint(%s,%s,%d,%p)",class_name, method_name, _bci, getBcp()); 345 #endif 346 } 347 348 349 // 350 // class VM_ChangeBreakpoints 351 // 352 // Modify the Breakpoints data structure at a safepoint 353 // 354 355 void VM_ChangeBreakpoints::doit() { 356 switch (_operation) { 357 case SET_BREAKPOINT: 358 _breakpoints->set_at_safepoint(*_bp); 359 break; 360 case CLEAR_BREAKPOINT: 361 _breakpoints->clear_at_safepoint(*_bp); 362 break; 363 default: 364 assert(false, "Unknown operation"); 365 } 366 } 367 368 void VM_ChangeBreakpoints::oops_do(OopClosure* f) { 369 // The JvmtiBreakpoints in _breakpoints will be visited via 370 // JvmtiExport::oops_do. 371 if (_bp != NULL) { 372 _bp->oops_do(f); 373 } 374 } 375 376 // 377 // class JvmtiBreakpoints 378 // 379 // a JVMTI internal collection of JvmtiBreakpoint 380 // 381 382 JvmtiBreakpoints::JvmtiBreakpoints(void listener_fun(void *,address *)) { 383 _bps.initialize(this,listener_fun); 384 } 385 386 JvmtiBreakpoints:: ~JvmtiBreakpoints() {} 387 388 void JvmtiBreakpoints::oops_do(OopClosure* f) { 389 _bps.oops_do(f); 390 } 391 392 void JvmtiBreakpoints::gc_epilogue() { 393 _bps.gc_epilogue(); 394 } 395 396 void JvmtiBreakpoints::print() { 397 #ifndef PRODUCT 398 ResourceMark rm; 399 400 int n = _bps.length(); 401 for (int i=0; i<n; i++) { 402 JvmtiBreakpoint& bp = _bps.at(i); 403 tty->print("%d: ", i); 404 bp.print(); 405 tty->print_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::gc_epilogue() { 511 if (_jvmti_breakpoints != NULL) { 512 _jvmti_breakpoints->gc_epilogue(); 513 } 514 } 515 516 /////////////////////////////////////////////////////////////// 517 // 518 // class VM_GetOrSetLocal 519 // 520 521 // Constructor for non-object getter 522 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, jint depth, int index, BasicType type) 523 : _thread(thread) 524 , _calling_thread(NULL) 525 , _depth(depth) 526 , _index(index) 527 , _type(type) 528 , _set(false) 529 , _jvf(NULL) 530 , _result(JVMTI_ERROR_NONE) 531 { 532 } 533 534 // Constructor for object or non-object setter 535 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, jint depth, int index, BasicType type, jvalue value) 536 : _thread(thread) 537 , _calling_thread(NULL) 538 , _depth(depth) 539 , _index(index) 540 , _type(type) 541 , _value(value) 542 , _set(true) 543 , _jvf(NULL) 544 , _result(JVMTI_ERROR_NONE) 545 { 546 } 547 548 // Constructor for object getter 549 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, JavaThread* calling_thread, jint depth, int index) 550 : _thread(thread) 551 , _calling_thread(calling_thread) 552 , _depth(depth) 553 , _index(index) 554 , _type(T_OBJECT) 555 , _set(false) 556 , _jvf(NULL) 557 , _result(JVMTI_ERROR_NONE) 558 { 559 } 560 561 vframe *VM_GetOrSetLocal::get_vframe() { 562 if (!_thread->has_last_Java_frame()) { 563 return NULL; 564 } 565 RegisterMap reg_map(_thread); 566 vframe *vf = _thread->last_java_vframe(®_map); 567 int d = 0; 568 while ((vf != NULL) && (d < _depth)) { 569 vf = vf->java_sender(); 570 d++; 571 } 572 return vf; 573 } 574 575 javaVFrame *VM_GetOrSetLocal::get_java_vframe() { 576 vframe* vf = get_vframe(); 577 if (vf == NULL) { 578 _result = JVMTI_ERROR_NO_MORE_FRAMES; 579 return NULL; 580 } 581 javaVFrame *jvf = (javaVFrame*)vf; 582 583 if (!vf->is_java_frame()) { 584 _result = JVMTI_ERROR_OPAQUE_FRAME; 585 return NULL; 586 } 587 return jvf; 588 } 589 590 // Check that the klass is assignable to a type with the given signature. 591 // Another solution could be to use the function Klass::is_subtype_of(type). 592 // But the type class can be forced to load/initialize eagerly in such a case. 593 // This may cause unexpected consequences like CFLH or class-init JVMTI events. 594 // It is better to avoid such a behavior. 595 bool VM_GetOrSetLocal::is_assignable(const char* ty_sign, Klass* klass, Thread* thread) { 596 assert(ty_sign != NULL, "type signature must not be NULL"); 597 assert(thread != NULL, "thread must not be NULL"); 598 assert(klass != NULL, "klass must not be NULL"); 599 600 int len = (int) strlen(ty_sign); 601 if (ty_sign[0] == 'L' && ty_sign[len-1] == ';') { // Need pure class/interface name 602 ty_sign++; 603 len -= 2; 604 } 605 TempNewSymbol ty_sym = SymbolTable::new_symbol(ty_sign, len, thread); 606 if (klass->name() == ty_sym) { 607 return true; 608 } 609 // Compare primary supers 610 int super_depth = klass->super_depth(); 611 int idx; 612 for (idx = 0; idx < super_depth; idx++) { 613 if (klass->primary_super_of_depth(idx)->name() == ty_sym) { 614 return true; 615 } 616 } 617 // Compare secondary supers 618 Array<Klass*>* sec_supers = klass->secondary_supers(); 619 for (idx = 0; idx < sec_supers->length(); idx++) { 620 if (((Klass*) sec_supers->at(idx))->name() == ty_sym) { 621 return true; 622 } 623 } 624 return false; 625 } 626 627 // Checks error conditions: 628 // JVMTI_ERROR_INVALID_SLOT 629 // JVMTI_ERROR_TYPE_MISMATCH 630 // Returns: 'true' - everything is Ok, 'false' - error code 631 632 bool VM_GetOrSetLocal::check_slot_type(javaVFrame* jvf) { 633 Method* method_oop = jvf->method(); 634 if (!method_oop->has_localvariable_table()) { 635 // Just to check index boundaries 636 jint extra_slot = (_type == T_LONG || _type == T_DOUBLE) ? 1 : 0; 637 if (_index < 0 || _index + extra_slot >= method_oop->max_locals()) { 638 _result = JVMTI_ERROR_INVALID_SLOT; 639 return false; 640 } 641 return true; 642 } 643 644 jint num_entries = method_oop->localvariable_table_length(); 645 if (num_entries == 0) { 646 _result = JVMTI_ERROR_INVALID_SLOT; 647 return false; // There are no slots 648 } 649 int signature_idx = -1; 650 int vf_bci = jvf->bci(); 651 LocalVariableTableElement* table = method_oop->localvariable_table_start(); 652 for (int i = 0; i < num_entries; i++) { 653 int start_bci = table[i].start_bci; 654 int end_bci = start_bci + table[i].length; 655 656 // Here we assume that locations of LVT entries 657 // with the same slot number cannot be overlapped 658 if (_index == (jint) table[i].slot && start_bci <= vf_bci && vf_bci <= end_bci) { 659 signature_idx = (int) table[i].descriptor_cp_index; 660 break; 661 } 662 } 663 if (signature_idx == -1) { 664 _result = JVMTI_ERROR_INVALID_SLOT; 665 return false; // Incorrect slot index 666 } 667 Symbol* sign_sym = method_oop->constants()->symbol_at(signature_idx); 668 const char* signature = (const char *) sign_sym->as_utf8(); 669 BasicType slot_type = char2type(signature[0]); 670 671 switch (slot_type) { 672 case T_BYTE: 673 case T_SHORT: 674 case T_CHAR: 675 case T_BOOLEAN: 676 slot_type = T_INT; 677 break; 678 case T_ARRAY: 679 slot_type = T_OBJECT; 680 break; 681 }; 682 if (_type != slot_type) { 683 _result = JVMTI_ERROR_TYPE_MISMATCH; 684 return false; 685 } 686 687 jobject jobj = _value.l; 688 if (_set && slot_type == T_OBJECT && jobj != NULL) { // NULL reference is allowed 689 // Check that the jobject class matches the return type signature. 690 JavaThread* cur_thread = JavaThread::current(); 691 HandleMark hm(cur_thread); 692 693 Handle obj = Handle(cur_thread, JNIHandles::resolve_external_guard(jobj)); 694 NULL_CHECK(obj, (_result = JVMTI_ERROR_INVALID_OBJECT, false)); 695 KlassHandle ob_kh = KlassHandle(cur_thread, obj->klass()); 696 NULL_CHECK(ob_kh, (_result = JVMTI_ERROR_INVALID_OBJECT, false)); 697 698 if (!is_assignable(signature, ob_kh(), cur_thread)) { 699 _result = JVMTI_ERROR_TYPE_MISMATCH; 700 return false; 701 } 702 } 703 return true; 704 } 705 706 static bool can_be_deoptimized(vframe* vf) { 707 return (vf->is_compiled_frame() && vf->fr().can_be_deoptimized()); 708 } 709 710 bool VM_GetOrSetLocal::doit_prologue() { 711 _jvf = get_java_vframe(); 712 NULL_CHECK(_jvf, false); 713 714 if (_jvf->method()->is_native()) { 715 if (getting_receiver() && !_jvf->method()->is_static()) { 716 return true; 717 } else { 718 _result = JVMTI_ERROR_OPAQUE_FRAME; 719 return false; 720 } 721 } 722 723 if (!check_slot_type(_jvf)) { 724 return false; 725 } 726 return true; 727 } 728 729 void VM_GetOrSetLocal::doit() { 730 if (_set) { 731 // Force deoptimization of frame if compiled because it's 732 // possible the compiler emitted some locals as constant values, 733 // meaning they are not mutable. 734 if (can_be_deoptimized(_jvf)) { 735 736 // Schedule deoptimization so that eventually the local 737 // update will be written to an interpreter frame. 738 Deoptimization::deoptimize_frame(_jvf->thread(), _jvf->fr().id()); 739 740 // Now store a new value for the local which will be applied 741 // once deoptimization occurs. Note however that while this 742 // write is deferred until deoptimization actually happens 743 // can vframe created after this point will have its locals 744 // reflecting this update so as far as anyone can see the 745 // write has already taken place. 746 747 // If we are updating an oop then get the oop from the handle 748 // since the handle will be long gone by the time the deopt 749 // happens. The oop stored in the deferred local will be 750 // gc'd on its own. 751 if (_type == T_OBJECT) { 752 _value.l = (jobject) (JNIHandles::resolve_external_guard(_value.l)); 753 } 754 // Re-read the vframe so we can see that it is deoptimized 755 // [ Only need because of assert in update_local() ] 756 _jvf = get_java_vframe(); 757 ((compiledVFrame*)_jvf)->update_local(_type, _index, _value); 758 return; 759 } 760 StackValueCollection *locals = _jvf->locals(); 761 HandleMark hm; 762 763 switch (_type) { 764 case T_INT: locals->set_int_at (_index, _value.i); break; 765 case T_LONG: locals->set_long_at (_index, _value.j); break; 766 case T_FLOAT: locals->set_float_at (_index, _value.f); break; 767 case T_DOUBLE: locals->set_double_at(_index, _value.d); break; 768 case T_OBJECT: { 769 Handle ob_h(JNIHandles::resolve_external_guard(_value.l)); 770 locals->set_obj_at (_index, ob_h); 771 break; 772 } 773 default: ShouldNotReachHere(); 774 } 775 _jvf->set_locals(locals); 776 } else { 777 if (_jvf->method()->is_native() && _jvf->is_compiled_frame()) { 778 assert(getting_receiver(), "Can only get here when getting receiver"); 779 oop receiver = _jvf->fr().get_native_receiver(); 780 _value.l = JNIHandles::make_local(_calling_thread, receiver); 781 } else { 782 StackValueCollection *locals = _jvf->locals(); 783 784 if (locals->at(_index)->type() == T_CONFLICT) { 785 memset(&_value, 0, sizeof(_value)); 786 _value.l = NULL; 787 return; 788 } 789 790 switch (_type) { 791 case T_INT: _value.i = locals->int_at (_index); break; 792 case T_LONG: _value.j = locals->long_at (_index); break; 793 case T_FLOAT: _value.f = locals->float_at (_index); break; 794 case T_DOUBLE: _value.d = locals->double_at(_index); break; 795 case T_OBJECT: { 796 // Wrap the oop to be returned in a local JNI handle since 797 // oops_do() no longer applies after doit() is finished. 798 oop obj = locals->obj_at(_index)(); 799 _value.l = JNIHandles::make_local(_calling_thread, obj); 800 break; 801 } 802 default: ShouldNotReachHere(); 803 } 804 } 805 } 806 } 807 808 809 bool VM_GetOrSetLocal::allow_nested_vm_operations() const { 810 return true; // May need to deoptimize 811 } 812 813 814 VM_GetReceiver::VM_GetReceiver( 815 JavaThread* thread, JavaThread* caller_thread, jint depth) 816 : VM_GetOrSetLocal(thread, caller_thread, depth, 0) {} 817 818 ///////////////////////////////////////////////////////////////////////////////////////// 819 820 // 821 // class JvmtiSuspendControl - see comments in jvmtiImpl.hpp 822 // 823 824 bool JvmtiSuspendControl::suspend(JavaThread *java_thread) { 825 // external suspend should have caught suspending a thread twice 826 827 // Immediate suspension required for JPDA back-end so JVMTI agent threads do 828 // not deadlock due to later suspension on transitions while holding 829 // raw monitors. Passing true causes the immediate suspension. 830 // java_suspend() will catch threads in the process of exiting 831 // and will ignore them. 832 java_thread->java_suspend(); 833 834 // It would be nice to have the following assertion in all the time, 835 // but it is possible for a racing resume request to have resumed 836 // this thread right after we suspended it. Temporarily enable this 837 // assertion if you are chasing a different kind of bug. 838 // 839 // assert(java_lang_Thread::thread(java_thread->threadObj()) == NULL || 840 // java_thread->is_being_ext_suspended(), "thread is not suspended"); 841 842 if (java_lang_Thread::thread(java_thread->threadObj()) == NULL) { 843 // check again because we can get delayed in java_suspend(): 844 // the thread is in process of exiting. 845 return false; 846 } 847 848 return true; 849 } 850 851 bool JvmtiSuspendControl::resume(JavaThread *java_thread) { 852 // external suspend should have caught resuming a thread twice 853 assert(java_thread->is_being_ext_suspended(), "thread should be suspended"); 854 855 // resume thread 856 { 857 // must always grab Threads_lock, see JVM_SuspendThread 858 MutexLocker ml(Threads_lock); 859 java_thread->java_resume(); 860 } 861 862 return true; 863 } 864 865 866 void JvmtiSuspendControl::print() { 867 #ifndef PRODUCT 868 MutexLocker mu(Threads_lock); 869 ResourceMark rm; 870 871 tty->print("Suspended Threads: ["); 872 for (JavaThread *thread = Threads::first(); thread != NULL; thread = thread->next()) { 873 #ifdef JVMTI_TRACE 874 const char *name = JvmtiTrace::safe_get_thread_name(thread); 875 #else 876 const char *name = ""; 877 #endif /*JVMTI_TRACE */ 878 tty->print("%s(%c ", name, thread->is_being_ext_suspended() ? 'S' : '_'); 879 if (!thread->has_last_Java_frame()) { 880 tty->print("no stack"); 881 } 882 tty->print(") "); 883 } 884 tty->print_cr("]"); 885 #endif 886 } 887 888 JvmtiDeferredEvent JvmtiDeferredEvent::compiled_method_load_event( 889 nmethod* nm) { 890 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_COMPILED_METHOD_LOAD); 891 event._event_data.compiled_method_load = nm; 892 // Keep the nmethod alive until the ServiceThread can process 893 // this deferred event. 894 nmethodLocker::lock_nmethod(nm); 895 return event; 896 } 897 898 JvmtiDeferredEvent JvmtiDeferredEvent::compiled_method_unload_event( 899 nmethod* nm, jmethodID id, const void* code) { 900 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_COMPILED_METHOD_UNLOAD); 901 event._event_data.compiled_method_unload.nm = nm; 902 event._event_data.compiled_method_unload.method_id = id; 903 event._event_data.compiled_method_unload.code_begin = code; 904 // Keep the nmethod alive until the ServiceThread can process 905 // this deferred event. This will keep the memory for the 906 // generated code from being reused too early. We pass 907 // zombie_ok == true here so that our nmethod that was just 908 // made into a zombie can be locked. 909 nmethodLocker::lock_nmethod(nm, true /* zombie_ok */); 910 return event; 911 } 912 913 JvmtiDeferredEvent JvmtiDeferredEvent::dynamic_code_generated_event( 914 const char* name, const void* code_begin, const void* code_end) { 915 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_DYNAMIC_CODE_GENERATED); 916 // Need to make a copy of the name since we don't know how long 917 // the event poster will keep it around after we enqueue the 918 // deferred event and return. strdup() failure is handled in 919 // the post() routine below. 920 event._event_data.dynamic_code_generated.name = os::strdup(name); 921 event._event_data.dynamic_code_generated.code_begin = code_begin; 922 event._event_data.dynamic_code_generated.code_end = code_end; 923 return event; 924 } 925 926 void JvmtiDeferredEvent::post() { 927 assert(ServiceThread::is_service_thread(Thread::current()), 928 "Service thread must post enqueued events"); 929 switch(_type) { 930 case TYPE_COMPILED_METHOD_LOAD: { 931 nmethod* nm = _event_data.compiled_method_load; 932 JvmtiExport::post_compiled_method_load(nm); 933 // done with the deferred event so unlock the nmethod 934 nmethodLocker::unlock_nmethod(nm); 935 break; 936 } 937 case TYPE_COMPILED_METHOD_UNLOAD: { 938 nmethod* nm = _event_data.compiled_method_unload.nm; 939 JvmtiExport::post_compiled_method_unload( 940 _event_data.compiled_method_unload.method_id, 941 _event_data.compiled_method_unload.code_begin); 942 // done with the deferred event so unlock the nmethod 943 nmethodLocker::unlock_nmethod(nm); 944 break; 945 } 946 case TYPE_DYNAMIC_CODE_GENERATED: { 947 JvmtiExport::post_dynamic_code_generated_internal( 948 // if strdup failed give the event a default name 949 (_event_data.dynamic_code_generated.name == NULL) 950 ? "unknown_code" : _event_data.dynamic_code_generated.name, 951 _event_data.dynamic_code_generated.code_begin, 952 _event_data.dynamic_code_generated.code_end); 953 if (_event_data.dynamic_code_generated.name != NULL) { 954 // release our copy 955 os::free((void *)_event_data.dynamic_code_generated.name); 956 } 957 break; 958 } 959 default: 960 ShouldNotReachHere(); 961 } 962 } 963 964 JvmtiDeferredEventQueue::QueueNode* JvmtiDeferredEventQueue::_queue_tail = NULL; 965 JvmtiDeferredEventQueue::QueueNode* JvmtiDeferredEventQueue::_queue_head = NULL; 966 967 volatile JvmtiDeferredEventQueue::QueueNode* 968 JvmtiDeferredEventQueue::_pending_list = NULL; 969 970 bool JvmtiDeferredEventQueue::has_events() { 971 assert(Service_lock->owned_by_self(), "Must own Service_lock"); 972 return _queue_head != NULL || _pending_list != NULL; 973 } 974 975 void JvmtiDeferredEventQueue::enqueue(const JvmtiDeferredEvent& event) { 976 assert(Service_lock->owned_by_self(), "Must own Service_lock"); 977 978 process_pending_events(); 979 980 // Events get added to the end of the queue (and are pulled off the front). 981 QueueNode* node = new QueueNode(event); 982 if (_queue_tail == NULL) { 983 _queue_tail = _queue_head = node; 984 } else { 985 assert(_queue_tail->next() == NULL, "Must be the last element in the list"); 986 _queue_tail->set_next(node); 987 _queue_tail = node; 988 } 989 990 Service_lock->notify_all(); 991 assert((_queue_head == NULL) == (_queue_tail == NULL), 992 "Inconsistent queue markers"); 993 } 994 995 JvmtiDeferredEvent JvmtiDeferredEventQueue::dequeue() { 996 assert(Service_lock->owned_by_self(), "Must own Service_lock"); 997 998 process_pending_events(); 999 1000 assert(_queue_head != NULL, "Nothing to dequeue"); 1001 1002 if (_queue_head == NULL) { 1003 // Just in case this happens in product; it shouldn't but let's not crash 1004 return JvmtiDeferredEvent(); 1005 } 1006 1007 QueueNode* node = _queue_head; 1008 _queue_head = _queue_head->next(); 1009 if (_queue_head == NULL) { 1010 _queue_tail = NULL; 1011 } 1012 1013 assert((_queue_head == NULL) == (_queue_tail == NULL), 1014 "Inconsistent queue markers"); 1015 1016 JvmtiDeferredEvent event = node->event(); 1017 delete node; 1018 return event; 1019 } 1020 1021 void JvmtiDeferredEventQueue::add_pending_event( 1022 const JvmtiDeferredEvent& event) { 1023 1024 QueueNode* node = new QueueNode(event); 1025 1026 bool success = false; 1027 QueueNode* prev_value = (QueueNode*)_pending_list; 1028 do { 1029 node->set_next(prev_value); 1030 prev_value = (QueueNode*)Atomic::cmpxchg_ptr( 1031 (void*)node, (volatile void*)&_pending_list, (void*)node->next()); 1032 } while (prev_value != node->next()); 1033 } 1034 1035 // This method transfers any events that were added by someone NOT holding 1036 // the lock into the mainline queue. 1037 void JvmtiDeferredEventQueue::process_pending_events() { 1038 assert(Service_lock->owned_by_self(), "Must own Service_lock"); 1039 1040 if (_pending_list != NULL) { 1041 QueueNode* head = 1042 (QueueNode*)Atomic::xchg_ptr(NULL, (volatile void*)&_pending_list); 1043 1044 assert((_queue_head == NULL) == (_queue_tail == NULL), 1045 "Inconsistent queue markers"); 1046 1047 if (head != NULL) { 1048 // Since we've treated the pending list as a stack (with newer 1049 // events at the beginning), we need to join the bottom of the stack 1050 // with the 'tail' of the queue in order to get the events in the 1051 // right order. We do this by reversing the pending list and appending 1052 // it to the queue. 1053 1054 QueueNode* new_tail = head; 1055 QueueNode* new_head = NULL; 1056 1057 // This reverses the list 1058 QueueNode* prev = new_tail; 1059 QueueNode* node = new_tail->next(); 1060 new_tail->set_next(NULL); 1061 while (node != NULL) { 1062 QueueNode* next = node->next(); 1063 node->set_next(prev); 1064 prev = node; 1065 node = next; 1066 } 1067 new_head = prev; 1068 1069 // Now append the new list to the queue 1070 if (_queue_tail != NULL) { 1071 _queue_tail->set_next(new_head); 1072 } else { // _queue_head == NULL 1073 _queue_head = new_head; 1074 } 1075 _queue_tail = new_tail; 1076 } 1077 } 1078 }