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/vframe.hpp" 45 #include "runtime/vframe_hp.hpp" 46 #include "runtime/vm_operations.hpp" 47 #include "utilities/exceptions.hpp" 48 #ifdef TARGET_OS_FAMILY_linux 49 # include "thread_linux.inline.hpp" 50 #endif 51 #ifdef TARGET_OS_FAMILY_solaris 52 # include "thread_solaris.inline.hpp" 53 #endif 54 #ifdef TARGET_OS_FAMILY_windows 55 # include "thread_windows.inline.hpp" 56 #endif 57 #ifdef TARGET_OS_FAMILY_bsd 58 # include "thread_bsd.inline.hpp" 59 #endif 60 61 // 62 // class JvmtiAgentThread 63 // 64 // JavaThread used to wrap a thread started by an agent 65 // using the JVMTI method RunAgentThread. 66 // 67 68 JvmtiAgentThread::JvmtiAgentThread(JvmtiEnv* env, jvmtiStartFunction start_fn, const void *start_arg) 69 : JavaThread(start_function_wrapper) { 70 _env = env; 71 _start_fn = start_fn; 72 _start_arg = start_arg; 73 } 74 75 void 76 JvmtiAgentThread::start_function_wrapper(JavaThread *thread, TRAPS) { 77 // It is expected that any Agent threads will be created as 78 // Java Threads. If this is the case, notification of the creation 79 // of the thread is given in JavaThread::thread_main(). 80 assert(thread->is_Java_thread(), "debugger thread should be a Java Thread"); 81 assert(thread == JavaThread::current(), "sanity check"); 82 83 JvmtiAgentThread *dthread = (JvmtiAgentThread *)thread; 84 dthread->call_start_function(); 85 } 86 87 void 88 JvmtiAgentThread::call_start_function() { 89 ThreadToNativeFromVM transition(this); 90 _start_fn(_env->jvmti_external(), jni_environment(), (void*)_start_arg); 91 } 92 93 94 // 95 // class GrowableCache - private methods 96 // 97 98 void GrowableCache::recache() { 99 int len = _elements->length(); 100 101 FREE_C_HEAP_ARRAY(address, _cache, mtInternal); 102 _cache = NEW_C_HEAP_ARRAY(address,len+1, mtInternal); 103 104 for (int i=0; i<len; i++) { 105 _cache[i] = _elements->at(i)->getCacheValue(); 106 // 107 // The cache entry has gone bad. Without a valid frame pointer 108 // value, the entry is useless so we simply delete it in product 109 // mode. The call to remove() will rebuild the cache again 110 // without the bad entry. 111 // 112 if (_cache[i] == NULL) { 113 assert(false, "cannot recache NULL elements"); 114 remove(i); 115 return; 116 } 117 } 118 _cache[len] = NULL; 119 120 _listener_fun(_this_obj,_cache); 121 } 122 123 bool GrowableCache::equals(void* v, GrowableElement *e2) { 124 GrowableElement *e1 = (GrowableElement *) v; 125 assert(e1 != NULL, "e1 != NULL"); 126 assert(e2 != NULL, "e2 != NULL"); 127 128 return e1->equals(e2); 129 } 130 131 // 132 // class GrowableCache - public methods 133 // 134 135 GrowableCache::GrowableCache() { 136 _this_obj = NULL; 137 _listener_fun = NULL; 138 _elements = NULL; 139 _cache = NULL; 140 } 141 142 GrowableCache::~GrowableCache() { 143 clear(); 144 delete _elements; 145 FREE_C_HEAP_ARRAY(address, _cache, mtInternal); 146 } 147 148 void GrowableCache::initialize(void *this_obj, void listener_fun(void *, address*) ) { 149 _this_obj = this_obj; 150 _listener_fun = listener_fun; 151 _elements = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<GrowableElement*>(5,true); 152 recache(); 153 } 154 155 // number of elements in the collection 156 int GrowableCache::length() { 157 return _elements->length(); 158 } 159 160 // get the value of the index element in the collection 161 GrowableElement* GrowableCache::at(int index) { 162 GrowableElement *e = (GrowableElement *) _elements->at(index); 163 assert(e != NULL, "e != NULL"); 164 return e; 165 } 166 167 int GrowableCache::find(GrowableElement* e) { 168 return _elements->find(e, GrowableCache::equals); 169 } 170 171 // append a copy of the element to the end of the collection 172 void GrowableCache::append(GrowableElement* e) { 173 GrowableElement *new_e = e->clone(); 174 _elements->append(new_e); 175 recache(); 176 } 177 178 // insert a copy of the element using lessthan() 179 void GrowableCache::insert(GrowableElement* e) { 180 GrowableElement *new_e = e->clone(); 181 _elements->append(new_e); 182 183 int n = length()-2; 184 for (int i=n; i>=0; i--) { 185 GrowableElement *e1 = _elements->at(i); 186 GrowableElement *e2 = _elements->at(i+1); 187 if (e2->lessThan(e1)) { 188 _elements->at_put(i+1, e1); 189 _elements->at_put(i, e2); 190 } 191 } 192 193 recache(); 194 } 195 196 // remove the element at index 197 void GrowableCache::remove (int index) { 198 GrowableElement *e = _elements->at(index); 199 assert(e != NULL, "e != NULL"); 200 _elements->remove(e); 201 delete e; 202 recache(); 203 } 204 205 // clear out all elements, release all heap space and 206 // let our listener know that things have changed. 207 void GrowableCache::clear() { 208 int len = _elements->length(); 209 for (int i=0; i<len; i++) { 210 delete _elements->at(i); 211 } 212 _elements->clear(); 213 recache(); 214 } 215 216 void GrowableCache::oops_do(OopClosure* f) { 217 int len = _elements->length(); 218 for (int i=0; i<len; i++) { 219 GrowableElement *e = _elements->at(i); 220 e->oops_do(f); 221 } 222 } 223 224 void GrowableCache::gc_epilogue() { 225 int len = _elements->length(); 226 for (int i=0; i<len; i++) { 227 _cache[i] = _elements->at(i)->getCacheValue(); 228 } 229 } 230 231 // 232 // class JvmtiBreakpoint 233 // 234 235 JvmtiBreakpoint::JvmtiBreakpoint() { 236 _method = NULL; 237 _bci = 0; 238 #ifdef CHECK_UNHANDLED_OOPS 239 // This one is always allocated with new, but check it just in case. 240 Thread *thread = Thread::current(); 241 if (thread->is_in_stack((address)&_method)) { 242 thread->allow_unhandled_oop((oop*)&_method); 243 } 244 #endif // CHECK_UNHANDLED_OOPS 245 } 246 247 JvmtiBreakpoint::JvmtiBreakpoint(methodOop m_method, jlocation location) { 248 _method = m_method; 249 assert(_method != NULL, "_method != NULL"); 250 _bci = (int) location; 251 #ifdef CHECK_UNHANDLED_OOPS 252 // Could be allocated with new and wouldn't be on the unhandled oop list. 253 Thread *thread = Thread::current(); 254 if (thread->is_in_stack((address)&_method)) { 255 thread->allow_unhandled_oop(&_method); 256 } 257 #endif // CHECK_UNHANDLED_OOPS 258 259 assert(_bci >= 0, "_bci >= 0"); 260 } 261 262 void JvmtiBreakpoint::copy(JvmtiBreakpoint& bp) { 263 _method = bp._method; 264 _bci = bp._bci; 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 return _method != NULL && 279 _bci >= 0; 280 } 281 282 address JvmtiBreakpoint::getBcp() { 283 return _method->bcp_from(_bci); 284 } 285 286 void JvmtiBreakpoint::each_method_version_do(method_action meth_act) { 287 ((methodOopDesc*)_method->*meth_act)(_bci); 288 289 // add/remove breakpoint to/from versions of the method that 290 // are EMCP. Directly or transitively obsolete methods are 291 // not saved in the PreviousVersionInfo. 292 Thread *thread = Thread::current(); 293 instanceKlassHandle ikh = instanceKlassHandle(thread, _method->method_holder()); 294 Symbol* m_name = _method->name(); 295 Symbol* m_signature = _method->signature(); 296 297 { 298 ResourceMark rm(thread); 299 // PreviousVersionInfo objects returned via PreviousVersionWalker 300 // contain a GrowableArray of handles. We have to clean up the 301 // GrowableArray _after_ the PreviousVersionWalker destructor 302 // has destroyed the handles. 303 { 304 // search previous versions if they exist 305 PreviousVersionWalker pvw((instanceKlass *)ikh()->klass_part()); 306 for (PreviousVersionInfo * pv_info = pvw.next_previous_version(); 307 pv_info != NULL; pv_info = pvw.next_previous_version()) { 308 GrowableArray<methodHandle>* methods = 309 pv_info->prev_EMCP_method_handles(); 310 311 if (methods == NULL) { 312 // We have run into a PreviousVersion generation where 313 // all methods were made obsolete during that generation's 314 // RedefineClasses() operation. At the time of that 315 // operation, all EMCP methods were flushed so we don't 316 // have to go back any further. 317 // 318 // A NULL methods array is different than an empty methods 319 // array. We cannot infer any optimizations about older 320 // generations from an empty methods array for the current 321 // generation. 322 break; 323 } 324 325 for (int i = methods->length() - 1; i >= 0; i--) { 326 methodHandle method = methods->at(i); 327 if (method->name() == m_name && method->signature() == m_signature) { 328 RC_TRACE(0x00000800, ("%sing breakpoint in %s(%s)", 329 meth_act == &methodOopDesc::set_breakpoint ? "sett" : "clear", 330 method->name()->as_C_string(), 331 method->signature()->as_C_string())); 332 assert(!method->is_obsolete(), "only EMCP methods here"); 333 334 ((methodOopDesc*)method()->*meth_act)(_bci); 335 break; 336 } 337 } 338 } 339 } // pvw is cleaned up 340 } // rm is cleaned up 341 } 342 343 void JvmtiBreakpoint::set() { 344 each_method_version_do(&methodOopDesc::set_breakpoint); 345 } 346 347 void JvmtiBreakpoint::clear() { 348 each_method_version_do(&methodOopDesc::clear_breakpoint); 349 } 350 351 void JvmtiBreakpoint::print() { 352 #ifndef PRODUCT 353 const char *class_name = (_method == NULL) ? "NULL" : _method->klass_name()->as_C_string(); 354 const char *method_name = (_method == NULL) ? "NULL" : _method->name()->as_C_string(); 355 356 tty->print("Breakpoint(%s,%s,%d,%p)",class_name, method_name, _bci, getBcp()); 357 #endif 358 } 359 360 361 // 362 // class VM_ChangeBreakpoints 363 // 364 // Modify the Breakpoints data structure at a safepoint 365 // 366 367 void VM_ChangeBreakpoints::doit() { 368 switch (_operation) { 369 case SET_BREAKPOINT: 370 _breakpoints->set_at_safepoint(*_bp); 371 break; 372 case CLEAR_BREAKPOINT: 373 _breakpoints->clear_at_safepoint(*_bp); 374 break; 375 case CLEAR_ALL_BREAKPOINT: 376 _breakpoints->clearall_at_safepoint(); 377 break; 378 default: 379 assert(false, "Unknown operation"); 380 } 381 } 382 383 void VM_ChangeBreakpoints::oops_do(OopClosure* f) { 384 // This operation keeps breakpoints alive 385 if (_breakpoints != NULL) { 386 _breakpoints->oops_do(f); 387 } 388 if (_bp != NULL) { 389 _bp->oops_do(f); 390 } 391 } 392 393 // 394 // class JvmtiBreakpoints 395 // 396 // a JVMTI internal collection of JvmtiBreakpoint 397 // 398 399 JvmtiBreakpoints::JvmtiBreakpoints(void listener_fun(void *,address *)) { 400 _bps.initialize(this,listener_fun); 401 } 402 403 JvmtiBreakpoints:: ~JvmtiBreakpoints() {} 404 405 void JvmtiBreakpoints::oops_do(OopClosure* f) { 406 _bps.oops_do(f); 407 } 408 409 void JvmtiBreakpoints::gc_epilogue() { 410 _bps.gc_epilogue(); 411 } 412 413 void JvmtiBreakpoints::print() { 414 #ifndef PRODUCT 415 ResourceMark rm; 416 417 int n = _bps.length(); 418 for (int i=0; i<n; i++) { 419 JvmtiBreakpoint& bp = _bps.at(i); 420 tty->print("%d: ", i); 421 bp.print(); 422 tty->print_cr(""); 423 } 424 #endif 425 } 426 427 428 void JvmtiBreakpoints::set_at_safepoint(JvmtiBreakpoint& bp) { 429 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint"); 430 431 int i = _bps.find(bp); 432 if (i == -1) { 433 _bps.append(bp); 434 bp.set(); 435 } 436 } 437 438 void JvmtiBreakpoints::clear_at_safepoint(JvmtiBreakpoint& bp) { 439 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint"); 440 441 int i = _bps.find(bp); 442 if (i != -1) { 443 _bps.remove(i); 444 bp.clear(); 445 } 446 } 447 448 void JvmtiBreakpoints::clearall_at_safepoint() { 449 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint"); 450 451 int len = _bps.length(); 452 for (int i=0; i<len; i++) { 453 _bps.at(i).clear(); 454 } 455 _bps.clear(); 456 } 457 458 int JvmtiBreakpoints::length() { return _bps.length(); } 459 460 int JvmtiBreakpoints::set(JvmtiBreakpoint& bp) { 461 if ( _bps.find(bp) != -1) { 462 return JVMTI_ERROR_DUPLICATE; 463 } 464 VM_ChangeBreakpoints set_breakpoint(this,VM_ChangeBreakpoints::SET_BREAKPOINT, &bp); 465 VMThread::execute(&set_breakpoint); 466 return JVMTI_ERROR_NONE; 467 } 468 469 int JvmtiBreakpoints::clear(JvmtiBreakpoint& bp) { 470 if ( _bps.find(bp) == -1) { 471 return JVMTI_ERROR_NOT_FOUND; 472 } 473 474 VM_ChangeBreakpoints clear_breakpoint(this,VM_ChangeBreakpoints::CLEAR_BREAKPOINT, &bp); 475 VMThread::execute(&clear_breakpoint); 476 return JVMTI_ERROR_NONE; 477 } 478 479 void JvmtiBreakpoints::clearall_in_class_at_safepoint(klassOop klass) { 480 bool changed = true; 481 // We are going to run thru the list of bkpts 482 // and delete some. This deletion probably alters 483 // the list in some implementation defined way such 484 // that when we delete entry i, the next entry might 485 // no longer be at i+1. To be safe, each time we delete 486 // an entry, we'll just start again from the beginning. 487 // We'll stop when we make a pass thru the whole list without 488 // deleting anything. 489 while (changed) { 490 int len = _bps.length(); 491 changed = false; 492 for (int i = 0; i < len; i++) { 493 JvmtiBreakpoint& bp = _bps.at(i); 494 if (bp.method()->method_holder() == klass) { 495 bp.clear(); 496 _bps.remove(i); 497 // This changed 'i' so we have to start over. 498 changed = true; 499 break; 500 } 501 } 502 } 503 } 504 505 void JvmtiBreakpoints::clearall() { 506 VM_ChangeBreakpoints clearall_breakpoint(this,VM_ChangeBreakpoints::CLEAR_ALL_BREAKPOINT); 507 VMThread::execute(&clearall_breakpoint); 508 } 509 510 // 511 // class JvmtiCurrentBreakpoints 512 // 513 514 JvmtiBreakpoints *JvmtiCurrentBreakpoints::_jvmti_breakpoints = NULL; 515 address * JvmtiCurrentBreakpoints::_breakpoint_list = NULL; 516 517 518 JvmtiBreakpoints& JvmtiCurrentBreakpoints::get_jvmti_breakpoints() { 519 if (_jvmti_breakpoints != NULL) return (*_jvmti_breakpoints); 520 _jvmti_breakpoints = new JvmtiBreakpoints(listener_fun); 521 assert(_jvmti_breakpoints != NULL, "_jvmti_breakpoints != NULL"); 522 return (*_jvmti_breakpoints); 523 } 524 525 void JvmtiCurrentBreakpoints::listener_fun(void *this_obj, address *cache) { 526 JvmtiBreakpoints *this_jvmti = (JvmtiBreakpoints *) this_obj; 527 assert(this_jvmti != NULL, "this_jvmti != NULL"); 528 529 debug_only(int n = this_jvmti->length();); 530 assert(cache[n] == NULL, "cache must be NULL terminated"); 531 532 set_breakpoint_list(cache); 533 } 534 535 536 void JvmtiCurrentBreakpoints::oops_do(OopClosure* f) { 537 if (_jvmti_breakpoints != NULL) { 538 _jvmti_breakpoints->oops_do(f); 539 } 540 } 541 542 void JvmtiCurrentBreakpoints::gc_epilogue() { 543 if (_jvmti_breakpoints != NULL) { 544 _jvmti_breakpoints->gc_epilogue(); 545 } 546 } 547 548 /////////////////////////////////////////////////////////////// 549 // 550 // class VM_GetOrSetLocal 551 // 552 553 // Constructor for non-object getter 554 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, jint depth, int index, BasicType type) 555 : _thread(thread) 556 , _calling_thread(NULL) 557 , _depth(depth) 558 , _index(index) 559 , _type(type) 560 , _set(false) 561 , _jvf(NULL) 562 , _result(JVMTI_ERROR_NONE) 563 { 564 } 565 566 // Constructor for object or non-object setter 567 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, jint depth, int index, BasicType type, jvalue value) 568 : _thread(thread) 569 , _calling_thread(NULL) 570 , _depth(depth) 571 , _index(index) 572 , _type(type) 573 , _value(value) 574 , _set(true) 575 , _jvf(NULL) 576 , _result(JVMTI_ERROR_NONE) 577 { 578 } 579 580 // Constructor for object getter 581 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, JavaThread* calling_thread, jint depth, int index) 582 : _thread(thread) 583 , _calling_thread(calling_thread) 584 , _depth(depth) 585 , _index(index) 586 , _type(T_OBJECT) 587 , _set(false) 588 , _jvf(NULL) 589 , _result(JVMTI_ERROR_NONE) 590 { 591 } 592 593 vframe *VM_GetOrSetLocal::get_vframe() { 594 if (!_thread->has_last_Java_frame()) { 595 return NULL; 596 } 597 RegisterMap reg_map(_thread); 598 vframe *vf = _thread->last_java_vframe(®_map); 599 int d = 0; 600 while ((vf != NULL) && (d < _depth)) { 601 vf = vf->java_sender(); 602 d++; 603 } 604 return vf; 605 } 606 607 javaVFrame *VM_GetOrSetLocal::get_java_vframe() { 608 vframe* vf = get_vframe(); 609 if (vf == NULL) { 610 _result = JVMTI_ERROR_NO_MORE_FRAMES; 611 return NULL; 612 } 613 javaVFrame *jvf = (javaVFrame*)vf; 614 615 if (!vf->is_java_frame()) { 616 _result = JVMTI_ERROR_OPAQUE_FRAME; 617 return NULL; 618 } 619 return jvf; 620 } 621 622 // Check that the klass is assignable to a type with the given signature. 623 // Another solution could be to use the function Klass::is_subtype_of(type). 624 // But the type class can be forced to load/initialize eagerly in such a case. 625 // This may cause unexpected consequences like CFLH or class-init JVMTI events. 626 // It is better to avoid such a behavior. 627 bool VM_GetOrSetLocal::is_assignable(const char* ty_sign, Klass* klass, Thread* thread) { 628 assert(ty_sign != NULL, "type signature must not be NULL"); 629 assert(thread != NULL, "thread must not be NULL"); 630 assert(klass != NULL, "klass must not be NULL"); 631 632 int len = (int) strlen(ty_sign); 633 if (ty_sign[0] == 'L' && ty_sign[len-1] == ';') { // Need pure class/interface name 634 ty_sign++; 635 len -= 2; 636 } 637 TempNewSymbol ty_sym = SymbolTable::new_symbol(ty_sign, len, thread); 638 if (klass->name() == ty_sym) { 639 return true; 640 } 641 // Compare primary supers 642 int super_depth = klass->super_depth(); 643 int idx; 644 for (idx = 0; idx < super_depth; idx++) { 645 if (Klass::cast(klass->primary_super_of_depth(idx))->name() == ty_sym) { 646 return true; 647 } 648 } 649 // Compare secondary supers 650 objArrayOop sec_supers = klass->secondary_supers(); 651 for (idx = 0; idx < sec_supers->length(); idx++) { 652 if (Klass::cast((klassOop) sec_supers->obj_at(idx))->name() == ty_sym) { 653 return true; 654 } 655 } 656 return false; 657 } 658 659 // Checks error conditions: 660 // JVMTI_ERROR_INVALID_SLOT 661 // JVMTI_ERROR_TYPE_MISMATCH 662 // Returns: 'true' - everything is Ok, 'false' - error code 663 664 bool VM_GetOrSetLocal::check_slot_type(javaVFrame* jvf) { 665 methodOop method_oop = jvf->method(); 666 if (!method_oop->has_localvariable_table()) { 667 // Just to check index boundaries 668 jint extra_slot = (_type == T_LONG || _type == T_DOUBLE) ? 1 : 0; 669 if (_index < 0 || _index + extra_slot >= method_oop->max_locals()) { 670 _result = JVMTI_ERROR_INVALID_SLOT; 671 return false; 672 } 673 return true; 674 } 675 676 jint num_entries = method_oop->localvariable_table_length(); 677 if (num_entries == 0) { 678 _result = JVMTI_ERROR_INVALID_SLOT; 679 return false; // There are no slots 680 } 681 int signature_idx = -1; 682 int vf_bci = jvf->bci(); 683 LocalVariableTableElement* table = method_oop->localvariable_table_start(); 684 for (int i = 0; i < num_entries; i++) { 685 int start_bci = table[i].start_bci; 686 int end_bci = start_bci + table[i].length; 687 688 // Here we assume that locations of LVT entries 689 // with the same slot number cannot be overlapped 690 if (_index == (jint) table[i].slot && start_bci <= vf_bci && vf_bci <= end_bci) { 691 signature_idx = (int) table[i].descriptor_cp_index; 692 break; 693 } 694 } 695 if (signature_idx == -1) { 696 _result = JVMTI_ERROR_INVALID_SLOT; 697 return false; // Incorrect slot index 698 } 699 Symbol* sign_sym = method_oop->constants()->symbol_at(signature_idx); 700 const char* signature = (const char *) sign_sym->as_utf8(); 701 BasicType slot_type = char2type(signature[0]); 702 703 switch (slot_type) { 704 case T_BYTE: 705 case T_SHORT: 706 case T_CHAR: 707 case T_BOOLEAN: 708 slot_type = T_INT; 709 break; 710 case T_ARRAY: 711 slot_type = T_OBJECT; 712 break; 713 }; 714 if (_type != slot_type) { 715 _result = JVMTI_ERROR_TYPE_MISMATCH; 716 return false; 717 } 718 719 jobject jobj = _value.l; 720 if (_set && slot_type == T_OBJECT && jobj != NULL) { // NULL reference is allowed 721 // Check that the jobject class matches the return type signature. 722 JavaThread* cur_thread = JavaThread::current(); 723 HandleMark hm(cur_thread); 724 725 Handle obj = Handle(cur_thread, JNIHandles::resolve_external_guard(jobj)); 726 NULL_CHECK(obj, (_result = JVMTI_ERROR_INVALID_OBJECT, false)); 727 KlassHandle ob_kh = KlassHandle(cur_thread, obj->klass()); 728 NULL_CHECK(ob_kh, (_result = JVMTI_ERROR_INVALID_OBJECT, false)); 729 730 if (!is_assignable(signature, Klass::cast(ob_kh()), cur_thread)) { 731 _result = JVMTI_ERROR_TYPE_MISMATCH; 732 return false; 733 } 734 } 735 return true; 736 } 737 738 static bool can_be_deoptimized(vframe* vf) { 739 return (vf->is_compiled_frame() && vf->fr().can_be_deoptimized()); 740 } 741 742 bool VM_GetOrSetLocal::doit_prologue() { 743 _jvf = get_java_vframe(); 744 NULL_CHECK(_jvf, false); 745 746 if (_jvf->method()->is_native()) { 747 if (getting_receiver() && !_jvf->method()->is_static()) { 748 return true; 749 } else { 750 _result = JVMTI_ERROR_OPAQUE_FRAME; 751 return false; 752 } 753 } 754 755 if (!check_slot_type(_jvf)) { 756 return false; 757 } 758 return true; 759 } 760 761 void VM_GetOrSetLocal::doit() { 762 if (_set) { 763 // Force deoptimization of frame if compiled because it's 764 // possible the compiler emitted some locals as constant values, 765 // meaning they are not mutable. 766 if (can_be_deoptimized(_jvf)) { 767 768 // Schedule deoptimization so that eventually the local 769 // update will be written to an interpreter frame. 770 Deoptimization::deoptimize_frame(_jvf->thread(), _jvf->fr().id()); 771 772 // Now store a new value for the local which will be applied 773 // once deoptimization occurs. Note however that while this 774 // write is deferred until deoptimization actually happens 775 // can vframe created after this point will have its locals 776 // reflecting this update so as far as anyone can see the 777 // write has already taken place. 778 779 // If we are updating an oop then get the oop from the handle 780 // since the handle will be long gone by the time the deopt 781 // happens. The oop stored in the deferred local will be 782 // gc'd on its own. 783 if (_type == T_OBJECT) { 784 _value.l = (jobject) (JNIHandles::resolve_external_guard(_value.l)); 785 } 786 // Re-read the vframe so we can see that it is deoptimized 787 // [ Only need because of assert in update_local() ] 788 _jvf = get_java_vframe(); 789 ((compiledVFrame*)_jvf)->update_local(_type, _index, _value); 790 return; 791 } 792 StackValueCollection *locals = _jvf->locals(); 793 HandleMark hm; 794 795 switch (_type) { 796 case T_INT: locals->set_int_at (_index, _value.i); break; 797 case T_LONG: locals->set_long_at (_index, _value.j); break; 798 case T_FLOAT: locals->set_float_at (_index, _value.f); break; 799 case T_DOUBLE: locals->set_double_at(_index, _value.d); break; 800 case T_OBJECT: { 801 Handle ob_h(JNIHandles::resolve_external_guard(_value.l)); 802 locals->set_obj_at (_index, ob_h); 803 break; 804 } 805 default: ShouldNotReachHere(); 806 } 807 _jvf->set_locals(locals); 808 } else { 809 if (_jvf->method()->is_native() && _jvf->is_compiled_frame()) { 810 assert(getting_receiver(), "Can only get here when getting receiver"); 811 oop receiver = _jvf->fr().get_native_receiver(); 812 _value.l = JNIHandles::make_local(_calling_thread, receiver); 813 } else { 814 StackValueCollection *locals = _jvf->locals(); 815 816 if (locals->at(_index)->type() == T_CONFLICT) { 817 memset(&_value, 0, sizeof(_value)); 818 _value.l = NULL; 819 return; 820 } 821 822 switch (_type) { 823 case T_INT: _value.i = locals->int_at (_index); break; 824 case T_LONG: _value.j = locals->long_at (_index); break; 825 case T_FLOAT: _value.f = locals->float_at (_index); break; 826 case T_DOUBLE: _value.d = locals->double_at(_index); break; 827 case T_OBJECT: { 828 // Wrap the oop to be returned in a local JNI handle since 829 // oops_do() no longer applies after doit() is finished. 830 oop obj = locals->obj_at(_index)(); 831 _value.l = JNIHandles::make_local(_calling_thread, obj); 832 break; 833 } 834 default: ShouldNotReachHere(); 835 } 836 } 837 } 838 } 839 840 841 bool VM_GetOrSetLocal::allow_nested_vm_operations() const { 842 return true; // May need to deoptimize 843 } 844 845 846 VM_GetReceiver::VM_GetReceiver( 847 JavaThread* thread, JavaThread* caller_thread, jint depth) 848 : VM_GetOrSetLocal(thread, caller_thread, depth, 0) {} 849 850 ///////////////////////////////////////////////////////////////////////////////////////// 851 852 // 853 // class JvmtiSuspendControl - see comments in jvmtiImpl.hpp 854 // 855 856 bool JvmtiSuspendControl::suspend(JavaThread *java_thread) { 857 // external suspend should have caught suspending a thread twice 858 859 // Immediate suspension required for JPDA back-end so JVMTI agent threads do 860 // not deadlock due to later suspension on transitions while holding 861 // raw monitors. Passing true causes the immediate suspension. 862 // java_suspend() will catch threads in the process of exiting 863 // and will ignore them. 864 java_thread->java_suspend(); 865 866 // It would be nice to have the following assertion in all the time, 867 // but it is possible for a racing resume request to have resumed 868 // this thread right after we suspended it. Temporarily enable this 869 // assertion if you are chasing a different kind of bug. 870 // 871 // assert(java_lang_Thread::thread(java_thread->threadObj()) == NULL || 872 // java_thread->is_being_ext_suspended(), "thread is not suspended"); 873 874 if (java_lang_Thread::thread(java_thread->threadObj()) == NULL) { 875 // check again because we can get delayed in java_suspend(): 876 // the thread is in process of exiting. 877 return false; 878 } 879 880 return true; 881 } 882 883 bool JvmtiSuspendControl::resume(JavaThread *java_thread) { 884 // external suspend should have caught resuming a thread twice 885 assert(java_thread->is_being_ext_suspended(), "thread should be suspended"); 886 887 // resume thread 888 { 889 // must always grab Threads_lock, see JVM_SuspendThread 890 MutexLocker ml(Threads_lock); 891 java_thread->java_resume(); 892 } 893 894 return true; 895 } 896 897 898 void JvmtiSuspendControl::print() { 899 #ifndef PRODUCT 900 MutexLocker mu(Threads_lock); 901 ResourceMark rm; 902 903 tty->print("Suspended Threads: ["); 904 for (JavaThread *thread = Threads::first(); thread != NULL; thread = thread->next()) { 905 #if JVMTI_TRACE 906 const char *name = JvmtiTrace::safe_get_thread_name(thread); 907 #else 908 const char *name = ""; 909 #endif /*JVMTI_TRACE */ 910 tty->print("%s(%c ", name, thread->is_being_ext_suspended() ? 'S' : '_'); 911 if (!thread->has_last_Java_frame()) { 912 tty->print("no stack"); 913 } 914 tty->print(") "); 915 } 916 tty->print_cr("]"); 917 #endif 918 } 919 920 JvmtiDeferredEvent JvmtiDeferredEvent::compiled_method_load_event( 921 nmethod* nm) { 922 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_COMPILED_METHOD_LOAD); 923 event._event_data.compiled_method_load = nm; 924 // Keep the nmethod alive until the ServiceThread can process 925 // this deferred event. 926 nmethodLocker::lock_nmethod(nm); 927 return event; 928 } 929 930 JvmtiDeferredEvent JvmtiDeferredEvent::compiled_method_unload_event( 931 nmethod* nm, jmethodID id, const void* code) { 932 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_COMPILED_METHOD_UNLOAD); 933 event._event_data.compiled_method_unload.nm = nm; 934 event._event_data.compiled_method_unload.method_id = id; 935 event._event_data.compiled_method_unload.code_begin = code; 936 // Keep the nmethod alive until the ServiceThread can process 937 // this deferred event. This will keep the memory for the 938 // generated code from being reused too early. We pass 939 // zombie_ok == true here so that our nmethod that was just 940 // made into a zombie can be locked. 941 nmethodLocker::lock_nmethod(nm, true /* zombie_ok */); 942 return event; 943 } 944 945 JvmtiDeferredEvent JvmtiDeferredEvent::dynamic_code_generated_event( 946 const char* name, const void* code_begin, const void* code_end) { 947 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_DYNAMIC_CODE_GENERATED); 948 // Need to make a copy of the name since we don't know how long 949 // the event poster will keep it around after we enqueue the 950 // deferred event and return. strdup() failure is handled in 951 // the post() routine below. 952 event._event_data.dynamic_code_generated.name = os::strdup(name); 953 event._event_data.dynamic_code_generated.code_begin = code_begin; 954 event._event_data.dynamic_code_generated.code_end = code_end; 955 return event; 956 } 957 958 void JvmtiDeferredEvent::post() { 959 assert(ServiceThread::is_service_thread(Thread::current()), 960 "Service thread must post enqueued events"); 961 switch(_type) { 962 case TYPE_COMPILED_METHOD_LOAD: { 963 nmethod* nm = _event_data.compiled_method_load; 964 JvmtiExport::post_compiled_method_load(nm); 965 // done with the deferred event so unlock the nmethod 966 nmethodLocker::unlock_nmethod(nm); 967 break; 968 } 969 case TYPE_COMPILED_METHOD_UNLOAD: { 970 nmethod* nm = _event_data.compiled_method_unload.nm; 971 JvmtiExport::post_compiled_method_unload( 972 _event_data.compiled_method_unload.method_id, 973 _event_data.compiled_method_unload.code_begin); 974 // done with the deferred event so unlock the nmethod 975 nmethodLocker::unlock_nmethod(nm); 976 break; 977 } 978 case TYPE_DYNAMIC_CODE_GENERATED: { 979 JvmtiExport::post_dynamic_code_generated_internal( 980 // if strdup failed give the event a default name 981 (_event_data.dynamic_code_generated.name == NULL) 982 ? "unknown_code" : _event_data.dynamic_code_generated.name, 983 _event_data.dynamic_code_generated.code_begin, 984 _event_data.dynamic_code_generated.code_end); 985 if (_event_data.dynamic_code_generated.name != NULL) { 986 // release our copy 987 os::free((void *)_event_data.dynamic_code_generated.name); 988 } 989 break; 990 } 991 default: 992 ShouldNotReachHere(); 993 } 994 } 995 996 JvmtiDeferredEventQueue::QueueNode* JvmtiDeferredEventQueue::_queue_tail = NULL; 997 JvmtiDeferredEventQueue::QueueNode* JvmtiDeferredEventQueue::_queue_head = NULL; 998 999 volatile JvmtiDeferredEventQueue::QueueNode* 1000 JvmtiDeferredEventQueue::_pending_list = NULL; 1001 1002 bool JvmtiDeferredEventQueue::has_events() { 1003 assert(Service_lock->owned_by_self(), "Must own Service_lock"); 1004 return _queue_head != NULL || _pending_list != NULL; 1005 } 1006 1007 void JvmtiDeferredEventQueue::enqueue(const JvmtiDeferredEvent& event) { 1008 assert(Service_lock->owned_by_self(), "Must own Service_lock"); 1009 1010 process_pending_events(); 1011 1012 // Events get added to the end of the queue (and are pulled off the front). 1013 QueueNode* node = new QueueNode(event); 1014 if (_queue_tail == NULL) { 1015 _queue_tail = _queue_head = node; 1016 } else { 1017 assert(_queue_tail->next() == NULL, "Must be the last element in the list"); 1018 _queue_tail->set_next(node); 1019 _queue_tail = node; 1020 } 1021 1022 Service_lock->notify_all(); 1023 assert((_queue_head == NULL) == (_queue_tail == NULL), 1024 "Inconsistent queue markers"); 1025 } 1026 1027 JvmtiDeferredEvent JvmtiDeferredEventQueue::dequeue() { 1028 assert(Service_lock->owned_by_self(), "Must own Service_lock"); 1029 1030 process_pending_events(); 1031 1032 assert(_queue_head != NULL, "Nothing to dequeue"); 1033 1034 if (_queue_head == NULL) { 1035 // Just in case this happens in product; it shouldn't but let's not crash 1036 return JvmtiDeferredEvent(); 1037 } 1038 1039 QueueNode* node = _queue_head; 1040 _queue_head = _queue_head->next(); 1041 if (_queue_head == NULL) { 1042 _queue_tail = NULL; 1043 } 1044 1045 assert((_queue_head == NULL) == (_queue_tail == NULL), 1046 "Inconsistent queue markers"); 1047 1048 JvmtiDeferredEvent event = node->event(); 1049 delete node; 1050 return event; 1051 } 1052 1053 void JvmtiDeferredEventQueue::add_pending_event( 1054 const JvmtiDeferredEvent& event) { 1055 1056 QueueNode* node = new QueueNode(event); 1057 1058 bool success = false; 1059 QueueNode* prev_value = (QueueNode*)_pending_list; 1060 do { 1061 node->set_next(prev_value); 1062 prev_value = (QueueNode*)Atomic::cmpxchg_ptr( 1063 (void*)node, (volatile void*)&_pending_list, (void*)node->next()); 1064 } while (prev_value != node->next()); 1065 } 1066 1067 // This method transfers any events that were added by someone NOT holding 1068 // the lock into the mainline queue. 1069 void JvmtiDeferredEventQueue::process_pending_events() { 1070 assert(Service_lock->owned_by_self(), "Must own Service_lock"); 1071 1072 if (_pending_list != NULL) { 1073 QueueNode* head = 1074 (QueueNode*)Atomic::xchg_ptr(NULL, (volatile void*)&_pending_list); 1075 1076 assert((_queue_head == NULL) == (_queue_tail == NULL), 1077 "Inconsistent queue markers"); 1078 1079 if (head != NULL) { 1080 // Since we've treated the pending list as a stack (with newer 1081 // events at the beginning), we need to join the bottom of the stack 1082 // with the 'tail' of the queue in order to get the events in the 1083 // right order. We do this by reversing the pending list and appending 1084 // it to the queue. 1085 1086 QueueNode* new_tail = head; 1087 QueueNode* new_head = NULL; 1088 1089 // This reverses the list 1090 QueueNode* prev = new_tail; 1091 QueueNode* node = new_tail->next(); 1092 new_tail->set_next(NULL); 1093 while (node != NULL) { 1094 QueueNode* next = node->next(); 1095 node->set_next(prev); 1096 prev = node; 1097 node = next; 1098 } 1099 new_head = prev; 1100 1101 // Now append the new list to the queue 1102 if (_queue_tail != NULL) { 1103 _queue_tail->set_next(new_head); 1104 } else { // _queue_head == NULL 1105 _queue_head = new_head; 1106 } 1107 _queue_tail = new_tail; 1108 } 1109 } 1110 }