1 /* 2 * Copyright (c) 2003, 2011, 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 58 // 59 // class JvmtiAgentThread 60 // 61 // JavaThread used to wrap a thread started by an agent 62 // using the JVMTI method RunAgentThread. 63 // 64 65 JvmtiAgentThread::JvmtiAgentThread(JvmtiEnv* env, jvmtiStartFunction start_fn, const void *start_arg) 66 : JavaThread(start_function_wrapper) { 67 _env = env; 68 _start_fn = start_fn; 69 _start_arg = start_arg; 70 } 71 72 void 73 JvmtiAgentThread::start_function_wrapper(JavaThread *thread, TRAPS) { 74 // It is expected that any Agent threads will be created as 75 // Java Threads. If this is the case, notification of the creation 76 // of the thread is given in JavaThread::thread_main(). 77 assert(thread->is_Java_thread(), "debugger thread should be a Java Thread"); 78 assert(thread == JavaThread::current(), "sanity check"); 79 80 JvmtiAgentThread *dthread = (JvmtiAgentThread *)thread; 81 dthread->call_start_function(); 82 } 83 84 void 85 JvmtiAgentThread::call_start_function() { 86 ThreadToNativeFromVM transition(this); 87 _start_fn(_env->jvmti_external(), jni_environment(), (void*)_start_arg); 88 } 89 90 91 // 92 // class GrowableCache - private methods 93 // 94 95 void GrowableCache::recache() { 96 int len = _elements->length(); 97 98 FREE_C_HEAP_ARRAY(address, _cache); 99 _cache = NEW_C_HEAP_ARRAY(address,len+1); 100 101 for (int i=0; i<len; i++) { 102 _cache[i] = _elements->at(i)->getCacheValue(); 103 // 104 // The cache entry has gone bad. Without a valid frame pointer 105 // value, the entry is useless so we simply delete it in product 106 // mode. The call to remove() will rebuild the cache again 107 // without the bad entry. 108 // 109 if (_cache[i] == NULL) { 110 assert(false, "cannot recache NULL elements"); 111 remove(i); 112 return; 113 } 114 } 115 _cache[len] = NULL; 116 117 _listener_fun(_this_obj,_cache); 118 } 119 120 bool GrowableCache::equals(void* v, GrowableElement *e2) { 121 GrowableElement *e1 = (GrowableElement *) v; 122 assert(e1 != NULL, "e1 != NULL"); 123 assert(e2 != NULL, "e2 != NULL"); 124 125 return e1->equals(e2); 126 } 127 128 // 129 // class GrowableCache - public methods 130 // 131 132 GrowableCache::GrowableCache() { 133 _this_obj = NULL; 134 _listener_fun = NULL; 135 _elements = NULL; 136 _cache = NULL; 137 } 138 139 GrowableCache::~GrowableCache() { 140 clear(); 141 delete _elements; 142 FREE_C_HEAP_ARRAY(address, _cache); 143 } 144 145 void GrowableCache::initialize(void *this_obj, void listener_fun(void *, address*) ) { 146 _this_obj = this_obj; 147 _listener_fun = listener_fun; 148 _elements = new (ResourceObj::C_HEAP) GrowableArray<GrowableElement*>(5,true); 149 recache(); 150 } 151 152 // number of elements in the collection 153 int GrowableCache::length() { 154 return _elements->length(); 155 } 156 157 // get the value of the index element in the collection 158 GrowableElement* GrowableCache::at(int index) { 159 GrowableElement *e = (GrowableElement *) _elements->at(index); 160 assert(e != NULL, "e != NULL"); 161 return e; 162 } 163 164 int GrowableCache::find(GrowableElement* e) { 165 return _elements->find(e, GrowableCache::equals); 166 } 167 168 // append a copy of the element to the end of the collection 169 void GrowableCache::append(GrowableElement* e) { 170 GrowableElement *new_e = e->clone(); 171 _elements->append(new_e); 172 recache(); 173 } 174 175 // insert a copy of the element using lessthan() 176 void GrowableCache::insert(GrowableElement* e) { 177 GrowableElement *new_e = e->clone(); 178 _elements->append(new_e); 179 180 int n = length()-2; 181 for (int i=n; i>=0; i--) { 182 GrowableElement *e1 = _elements->at(i); 183 GrowableElement *e2 = _elements->at(i+1); 184 if (e2->lessThan(e1)) { 185 _elements->at_put(i+1, e1); 186 _elements->at_put(i, e2); 187 } 188 } 189 190 recache(); 191 } 192 193 // remove the element at index 194 void GrowableCache::remove (int index) { 195 GrowableElement *e = _elements->at(index); 196 assert(e != NULL, "e != NULL"); 197 _elements->remove(e); 198 delete e; 199 recache(); 200 } 201 202 // clear out all elements, release all heap space and 203 // let our listener know that things have changed. 204 void GrowableCache::clear() { 205 int len = _elements->length(); 206 for (int i=0; i<len; i++) { 207 delete _elements->at(i); 208 } 209 _elements->clear(); 210 recache(); 211 } 212 213 void GrowableCache::oops_do(OopClosure* f) { 214 int len = _elements->length(); 215 for (int i=0; i<len; i++) { 216 GrowableElement *e = _elements->at(i); 217 e->oops_do(f); 218 } 219 } 220 221 void GrowableCache::gc_epilogue() { 222 int len = _elements->length(); 223 for (int i=0; i<len; i++) { 224 _cache[i] = _elements->at(i)->getCacheValue(); 225 } 226 } 227 228 // 229 // class JvmtiBreakpoint 230 // 231 232 JvmtiBreakpoint::JvmtiBreakpoint() { 233 _method = NULL; 234 _bci = 0; 235 #ifdef CHECK_UNHANDLED_OOPS 236 // This one is always allocated with new, but check it just in case. 237 Thread *thread = Thread::current(); 238 if (thread->is_in_stack((address)&_method)) { 239 thread->allow_unhandled_oop((oop*)&_method); 240 } 241 #endif // CHECK_UNHANDLED_OOPS 242 } 243 244 JvmtiBreakpoint::JvmtiBreakpoint(methodOop m_method, jlocation location) { 245 _method = m_method; 246 assert(_method != NULL, "_method != NULL"); 247 _bci = (int) location; 248 #ifdef CHECK_UNHANDLED_OOPS 249 // Could be allocated with new and wouldn't be on the unhandled oop list. 250 Thread *thread = Thread::current(); 251 if (thread->is_in_stack((address)&_method)) { 252 thread->allow_unhandled_oop(&_method); 253 } 254 #endif // CHECK_UNHANDLED_OOPS 255 256 assert(_bci >= 0, "_bci >= 0"); 257 } 258 259 void JvmtiBreakpoint::copy(JvmtiBreakpoint& bp) { 260 _method = bp._method; 261 _bci = bp._bci; 262 } 263 264 bool JvmtiBreakpoint::lessThan(JvmtiBreakpoint& bp) { 265 Unimplemented(); 266 return false; 267 } 268 269 bool JvmtiBreakpoint::equals(JvmtiBreakpoint& bp) { 270 return _method == bp._method 271 && _bci == bp._bci; 272 } 273 274 bool JvmtiBreakpoint::is_valid() { 275 return _method != NULL && 276 _bci >= 0; 277 } 278 279 address JvmtiBreakpoint::getBcp() { 280 return _method->bcp_from(_bci); 281 } 282 283 void JvmtiBreakpoint::each_method_version_do(method_action meth_act) { 284 ((methodOopDesc*)_method->*meth_act)(_bci); 285 286 // add/remove breakpoint to/from versions of the method that 287 // are EMCP. Directly or transitively obsolete methods are 288 // not saved in the PreviousVersionInfo. 289 Thread *thread = Thread::current(); 290 instanceKlassHandle ikh = instanceKlassHandle(thread, _method->method_holder()); 291 Symbol* m_name = _method->name(); 292 Symbol* m_signature = _method->signature(); 293 294 { 295 ResourceMark rm(thread); 296 // PreviousVersionInfo objects returned via PreviousVersionWalker 297 // contain a GrowableArray of handles. We have to clean up the 298 // GrowableArray _after_ the PreviousVersionWalker destructor 299 // has destroyed the handles. 300 { 301 // search previous versions if they exist 302 PreviousVersionWalker pvw((instanceKlass *)ikh()->klass_part()); 303 for (PreviousVersionInfo * pv_info = pvw.next_previous_version(); 304 pv_info != NULL; pv_info = pvw.next_previous_version()) { 305 GrowableArray<methodHandle>* methods = 306 pv_info->prev_EMCP_method_handles(); 307 308 if (methods == NULL) { 309 // We have run into a PreviousVersion generation where 310 // all methods were made obsolete during that generation's 311 // RedefineClasses() operation. At the time of that 312 // operation, all EMCP methods were flushed so we don't 313 // have to go back any further. 314 // 315 // A NULL methods array is different than an empty methods 316 // array. We cannot infer any optimizations about older 317 // generations from an empty methods array for the current 318 // generation. 319 break; 320 } 321 322 for (int i = methods->length() - 1; i >= 0; i--) { 323 methodHandle method = methods->at(i); 324 if (method->name() == m_name && method->signature() == m_signature) { 325 RC_TRACE(0x00000800, ("%sing breakpoint in %s(%s)", 326 meth_act == &methodOopDesc::set_breakpoint ? "sett" : "clear", 327 method->name()->as_C_string(), 328 method->signature()->as_C_string())); 329 assert(!method->is_obsolete(), "only EMCP methods here"); 330 331 ((methodOopDesc*)method()->*meth_act)(_bci); 332 break; 333 } 334 } 335 } 336 } // pvw is cleaned up 337 } // rm is cleaned up 338 } 339 340 void JvmtiBreakpoint::set() { 341 each_method_version_do(&methodOopDesc::set_breakpoint); 342 } 343 344 void JvmtiBreakpoint::clear() { 345 each_method_version_do(&methodOopDesc::clear_breakpoint); 346 } 347 348 void JvmtiBreakpoint::print() { 349 #ifndef PRODUCT 350 const char *class_name = (_method == NULL) ? "NULL" : _method->klass_name()->as_C_string(); 351 const char *method_name = (_method == NULL) ? "NULL" : _method->name()->as_C_string(); 352 353 tty->print("Breakpoint(%s,%s,%d,%p)",class_name, method_name, _bci, getBcp()); 354 #endif 355 } 356 357 358 // 359 // class VM_ChangeBreakpoints 360 // 361 // Modify the Breakpoints data structure at a safepoint 362 // 363 364 void VM_ChangeBreakpoints::doit() { 365 switch (_operation) { 366 case SET_BREAKPOINT: 367 _breakpoints->set_at_safepoint(*_bp); 368 break; 369 case CLEAR_BREAKPOINT: 370 _breakpoints->clear_at_safepoint(*_bp); 371 break; 372 case CLEAR_ALL_BREAKPOINT: 373 _breakpoints->clearall_at_safepoint(); 374 break; 375 default: 376 assert(false, "Unknown operation"); 377 } 378 } 379 380 void VM_ChangeBreakpoints::oops_do(OopClosure* f) { 381 // This operation keeps breakpoints alive 382 if (_breakpoints != NULL) { 383 _breakpoints->oops_do(f); 384 } 385 if (_bp != NULL) { 386 _bp->oops_do(f); 387 } 388 } 389 390 // 391 // class JvmtiBreakpoints 392 // 393 // a JVMTI internal collection of JvmtiBreakpoint 394 // 395 396 JvmtiBreakpoints::JvmtiBreakpoints(void listener_fun(void *,address *)) { 397 _bps.initialize(this,listener_fun); 398 } 399 400 JvmtiBreakpoints:: ~JvmtiBreakpoints() {} 401 402 void JvmtiBreakpoints::oops_do(OopClosure* f) { 403 _bps.oops_do(f); 404 } 405 406 void JvmtiBreakpoints::gc_epilogue() { 407 _bps.gc_epilogue(); 408 } 409 410 void JvmtiBreakpoints::print() { 411 #ifndef PRODUCT 412 ResourceMark rm; 413 414 int n = _bps.length(); 415 for (int i=0; i<n; i++) { 416 JvmtiBreakpoint& bp = _bps.at(i); 417 tty->print("%d: ", i); 418 bp.print(); 419 tty->print_cr(""); 420 } 421 #endif 422 } 423 424 425 void JvmtiBreakpoints::set_at_safepoint(JvmtiBreakpoint& bp) { 426 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint"); 427 428 int i = _bps.find(bp); 429 if (i == -1) { 430 _bps.append(bp); 431 bp.set(); 432 } 433 } 434 435 void JvmtiBreakpoints::clear_at_safepoint(JvmtiBreakpoint& bp) { 436 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint"); 437 438 int i = _bps.find(bp); 439 if (i != -1) { 440 _bps.remove(i); 441 bp.clear(); 442 } 443 } 444 445 void JvmtiBreakpoints::clearall_at_safepoint() { 446 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint"); 447 448 int len = _bps.length(); 449 for (int i=0; i<len; i++) { 450 _bps.at(i).clear(); 451 } 452 _bps.clear(); 453 } 454 455 int JvmtiBreakpoints::length() { return _bps.length(); } 456 457 int JvmtiBreakpoints::set(JvmtiBreakpoint& bp) { 458 if ( _bps.find(bp) != -1) { 459 return JVMTI_ERROR_DUPLICATE; 460 } 461 VM_ChangeBreakpoints set_breakpoint(this,VM_ChangeBreakpoints::SET_BREAKPOINT, &bp); 462 VMThread::execute(&set_breakpoint); 463 return JVMTI_ERROR_NONE; 464 } 465 466 int JvmtiBreakpoints::clear(JvmtiBreakpoint& bp) { 467 if ( _bps.find(bp) == -1) { 468 return JVMTI_ERROR_NOT_FOUND; 469 } 470 471 VM_ChangeBreakpoints clear_breakpoint(this,VM_ChangeBreakpoints::CLEAR_BREAKPOINT, &bp); 472 VMThread::execute(&clear_breakpoint); 473 return JVMTI_ERROR_NONE; 474 } 475 476 void JvmtiBreakpoints::clearall_in_class_at_safepoint(klassOop klass) { 477 bool changed = true; 478 // We are going to run thru the list of bkpts 479 // and delete some. This deletion probably alters 480 // the list in some implementation defined way such 481 // that when we delete entry i, the next entry might 482 // no longer be at i+1. To be safe, each time we delete 483 // an entry, we'll just start again from the beginning. 484 // We'll stop when we make a pass thru the whole list without 485 // deleting anything. 486 while (changed) { 487 int len = _bps.length(); 488 changed = false; 489 for (int i = 0; i < len; i++) { 490 JvmtiBreakpoint& bp = _bps.at(i); 491 if (bp.method()->method_holder() == klass) { 492 bp.clear(); 493 _bps.remove(i); 494 // This changed 'i' so we have to start over. 495 changed = true; 496 break; 497 } 498 } 499 } 500 } 501 502 void JvmtiBreakpoints::clearall() { 503 VM_ChangeBreakpoints clearall_breakpoint(this,VM_ChangeBreakpoints::CLEAR_ALL_BREAKPOINT); 504 VMThread::execute(&clearall_breakpoint); 505 } 506 507 // 508 // class JvmtiCurrentBreakpoints 509 // 510 511 JvmtiBreakpoints *JvmtiCurrentBreakpoints::_jvmti_breakpoints = NULL; 512 address * JvmtiCurrentBreakpoints::_breakpoint_list = NULL; 513 514 515 JvmtiBreakpoints& JvmtiCurrentBreakpoints::get_jvmti_breakpoints() { 516 if (_jvmti_breakpoints != NULL) return (*_jvmti_breakpoints); 517 _jvmti_breakpoints = new JvmtiBreakpoints(listener_fun); 518 assert(_jvmti_breakpoints != NULL, "_jvmti_breakpoints != NULL"); 519 return (*_jvmti_breakpoints); 520 } 521 522 void JvmtiCurrentBreakpoints::listener_fun(void *this_obj, address *cache) { 523 JvmtiBreakpoints *this_jvmti = (JvmtiBreakpoints *) this_obj; 524 assert(this_jvmti != NULL, "this_jvmti != NULL"); 525 526 debug_only(int n = this_jvmti->length();); 527 assert(cache[n] == NULL, "cache must be NULL terminated"); 528 529 set_breakpoint_list(cache); 530 } 531 532 533 void JvmtiCurrentBreakpoints::oops_do(OopClosure* f) { 534 if (_jvmti_breakpoints != NULL) { 535 _jvmti_breakpoints->oops_do(f); 536 } 537 } 538 539 void JvmtiCurrentBreakpoints::gc_epilogue() { 540 if (_jvmti_breakpoints != NULL) { 541 _jvmti_breakpoints->gc_epilogue(); 542 } 543 } 544 545 /////////////////////////////////////////////////////////////// 546 // 547 // class VM_GetOrSetLocal 548 // 549 550 // Constructor for non-object getter 551 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, jint depth, int index, BasicType type) 552 : _thread(thread) 553 , _calling_thread(NULL) 554 , _depth(depth) 555 , _index(index) 556 , _type(type) 557 , _set(false) 558 , _jvf(NULL) 559 , _result(JVMTI_ERROR_NONE) 560 { 561 } 562 563 // Constructor for object or non-object setter 564 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, jint depth, int index, BasicType type, jvalue value) 565 : _thread(thread) 566 , _calling_thread(NULL) 567 , _depth(depth) 568 , _index(index) 569 , _type(type) 570 , _value(value) 571 , _set(true) 572 , _jvf(NULL) 573 , _result(JVMTI_ERROR_NONE) 574 { 575 } 576 577 // Constructor for object getter 578 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, JavaThread* calling_thread, jint depth, int index) 579 : _thread(thread) 580 , _calling_thread(calling_thread) 581 , _depth(depth) 582 , _index(index) 583 , _type(T_OBJECT) 584 , _set(false) 585 , _jvf(NULL) 586 , _result(JVMTI_ERROR_NONE) 587 { 588 } 589 590 vframe *VM_GetOrSetLocal::get_vframe() { 591 if (!_thread->has_last_Java_frame()) { 592 return NULL; 593 } 594 RegisterMap reg_map(_thread); 595 vframe *vf = _thread->last_java_vframe(®_map); 596 int d = 0; 597 while ((vf != NULL) && (d < _depth)) { 598 vf = vf->java_sender(); 599 d++; 600 } 601 return vf; 602 } 603 604 javaVFrame *VM_GetOrSetLocal::get_java_vframe() { 605 vframe* vf = get_vframe(); 606 if (vf == NULL) { 607 _result = JVMTI_ERROR_NO_MORE_FRAMES; 608 return NULL; 609 } 610 javaVFrame *jvf = (javaVFrame*)vf; 611 612 if (!vf->is_java_frame()) { 613 _result = JVMTI_ERROR_OPAQUE_FRAME; 614 return NULL; 615 } 616 return jvf; 617 } 618 619 // Check that the klass is assignable to a type with the given signature. 620 // Another solution could be to use the function Klass::is_subtype_of(type). 621 // But the type class can be forced to load/initialize eagerly in such a case. 622 // This may cause unexpected consequences like CFLH or class-init JVMTI events. 623 // It is better to avoid such a behavior. 624 bool VM_GetOrSetLocal::is_assignable(const char* ty_sign, Klass* klass, Thread* thread) { 625 assert(ty_sign != NULL, "type signature must not be NULL"); 626 assert(thread != NULL, "thread must not be NULL"); 627 assert(klass != NULL, "klass must not be NULL"); 628 629 int len = (int) strlen(ty_sign); 630 if (ty_sign[0] == 'L' && ty_sign[len-1] == ';') { // Need pure class/interface name 631 ty_sign++; 632 len -= 2; 633 } 634 TempNewSymbol ty_sym = SymbolTable::new_symbol(ty_sign, len, thread); 635 if (klass->name() == ty_sym) { 636 return true; 637 } 638 // Compare primary supers 639 int super_depth = klass->super_depth(); 640 int idx; 641 for (idx = 0; idx < super_depth; idx++) { 642 if (Klass::cast(klass->primary_super_of_depth(idx))->name() == ty_sym) { 643 return true; 644 } 645 } 646 // Compare secondary supers 647 objArrayOop sec_supers = klass->secondary_supers(); 648 for (idx = 0; idx < sec_supers->length(); idx++) { 649 if (Klass::cast((klassOop) sec_supers->obj_at(idx))->name() == ty_sym) { 650 return true; 651 } 652 } 653 return false; 654 } 655 656 // Checks error conditions: 657 // JVMTI_ERROR_INVALID_SLOT 658 // JVMTI_ERROR_TYPE_MISMATCH 659 // Returns: 'true' - everything is Ok, 'false' - error code 660 661 bool VM_GetOrSetLocal::check_slot_type(javaVFrame* jvf) { 662 methodOop method_oop = jvf->method(); 663 if (!method_oop->has_localvariable_table()) { 664 // Just to check index boundaries 665 jint extra_slot = (_type == T_LONG || _type == T_DOUBLE) ? 1 : 0; 666 if (_index < 0 || _index + extra_slot >= method_oop->max_locals()) { 667 _result = JVMTI_ERROR_INVALID_SLOT; 668 return false; 669 } 670 return true; 671 } 672 673 jint num_entries = method_oop->localvariable_table_length(); 674 if (num_entries == 0) { 675 _result = JVMTI_ERROR_INVALID_SLOT; 676 return false; // There are no slots 677 } 678 int signature_idx = -1; 679 int vf_bci = jvf->bci(); 680 LocalVariableTableElement* table = method_oop->localvariable_table_start(); 681 for (int i = 0; i < num_entries; i++) { 682 int start_bci = table[i].start_bci; 683 int end_bci = start_bci + table[i].length; 684 685 // Here we assume that locations of LVT entries 686 // with the same slot number cannot be overlapped 687 if (_index == (jint) table[i].slot && start_bci <= vf_bci && vf_bci <= end_bci) { 688 signature_idx = (int) table[i].descriptor_cp_index; 689 break; 690 } 691 } 692 if (signature_idx == -1) { 693 _result = JVMTI_ERROR_INVALID_SLOT; 694 return false; // Incorrect slot index 695 } 696 Symbol* sign_sym = method_oop->constants()->symbol_at(signature_idx); 697 const char* signature = (const char *) sign_sym->as_utf8(); 698 BasicType slot_type = char2type(signature[0]); 699 700 switch (slot_type) { 701 case T_BYTE: 702 case T_SHORT: 703 case T_CHAR: 704 case T_BOOLEAN: 705 slot_type = T_INT; 706 break; 707 case T_ARRAY: 708 slot_type = T_OBJECT; 709 break; 710 }; 711 if (_type != slot_type) { 712 _result = JVMTI_ERROR_TYPE_MISMATCH; 713 return false; 714 } 715 716 jobject jobj = _value.l; 717 if (_set && slot_type == T_OBJECT && jobj != NULL) { // NULL reference is allowed 718 // Check that the jobject class matches the return type signature. 719 JavaThread* cur_thread = JavaThread::current(); 720 HandleMark hm(cur_thread); 721 722 Handle obj = Handle(cur_thread, JNIHandles::resolve_external_guard(jobj)); 723 NULL_CHECK(obj, (_result = JVMTI_ERROR_INVALID_OBJECT, false)); 724 KlassHandle ob_kh = KlassHandle(cur_thread, obj->klass()); 725 NULL_CHECK(ob_kh, (_result = JVMTI_ERROR_INVALID_OBJECT, false)); 726 727 if (!is_assignable(signature, Klass::cast(ob_kh()), cur_thread)) { 728 _result = JVMTI_ERROR_TYPE_MISMATCH; 729 return false; 730 } 731 } 732 return true; 733 } 734 735 static bool can_be_deoptimized(vframe* vf) { 736 return (vf->is_compiled_frame() && vf->fr().can_be_deoptimized()); 737 } 738 739 bool VM_GetOrSetLocal::doit_prologue() { 740 _jvf = get_java_vframe(); 741 NULL_CHECK(_jvf, false); 742 743 if (_jvf->method()->is_native()) { 744 if (getting_receiver() && !_jvf->method()->is_static()) { 745 return true; 746 } else { 747 _result = JVMTI_ERROR_OPAQUE_FRAME; 748 return false; 749 } 750 } 751 752 if (!check_slot_type(_jvf)) { 753 return false; 754 } 755 return true; 756 } 757 758 void VM_GetOrSetLocal::doit() { 759 if (_set) { 760 // Force deoptimization of frame if compiled because it's 761 // possible the compiler emitted some locals as constant values, 762 // meaning they are not mutable. 763 if (can_be_deoptimized(_jvf)) { 764 765 // Schedule deoptimization so that eventually the local 766 // update will be written to an interpreter frame. 767 Deoptimization::deoptimize_frame(_jvf->thread(), _jvf->fr().id()); 768 769 // Now store a new value for the local which will be applied 770 // once deoptimization occurs. Note however that while this 771 // write is deferred until deoptimization actually happens 772 // can vframe created after this point will have its locals 773 // reflecting this update so as far as anyone can see the 774 // write has already taken place. 775 776 // If we are updating an oop then get the oop from the handle 777 // since the handle will be long gone by the time the deopt 778 // happens. The oop stored in the deferred local will be 779 // gc'd on its own. 780 if (_type == T_OBJECT) { 781 _value.l = (jobject) (JNIHandles::resolve_external_guard(_value.l)); 782 } 783 // Re-read the vframe so we can see that it is deoptimized 784 // [ Only need because of assert in update_local() ] 785 _jvf = get_java_vframe(); 786 ((compiledVFrame*)_jvf)->update_local(_type, _index, _value); 787 return; 788 } 789 StackValueCollection *locals = _jvf->locals(); 790 HandleMark hm; 791 792 switch (_type) { 793 case T_INT: locals->set_int_at (_index, _value.i); break; 794 case T_LONG: locals->set_long_at (_index, _value.j); break; 795 case T_FLOAT: locals->set_float_at (_index, _value.f); break; 796 case T_DOUBLE: locals->set_double_at(_index, _value.d); break; 797 case T_OBJECT: { 798 Handle ob_h(JNIHandles::resolve_external_guard(_value.l)); 799 locals->set_obj_at (_index, ob_h); 800 break; 801 } 802 default: ShouldNotReachHere(); 803 } 804 _jvf->set_locals(locals); 805 } else { 806 if (_jvf->method()->is_native() && _jvf->is_compiled_frame()) { 807 assert(getting_receiver(), "Can only get here when getting receiver"); 808 oop receiver = _jvf->fr().get_native_receiver(); 809 _value.l = JNIHandles::make_local(_calling_thread, receiver); 810 } else { 811 StackValueCollection *locals = _jvf->locals(); 812 813 if (locals->at(_index)->type() == T_CONFLICT) { 814 memset(&_value, 0, sizeof(_value)); 815 _value.l = NULL; 816 return; 817 } 818 819 switch (_type) { 820 case T_INT: _value.i = locals->int_at (_index); break; 821 case T_LONG: _value.j = locals->long_at (_index); break; 822 case T_FLOAT: _value.f = locals->float_at (_index); break; 823 case T_DOUBLE: _value.d = locals->double_at(_index); break; 824 case T_OBJECT: { 825 // Wrap the oop to be returned in a local JNI handle since 826 // oops_do() no longer applies after doit() is finished. 827 oop obj = locals->obj_at(_index)(); 828 _value.l = JNIHandles::make_local(_calling_thread, obj); 829 break; 830 } 831 default: ShouldNotReachHere(); 832 } 833 } 834 } 835 } 836 837 838 bool VM_GetOrSetLocal::allow_nested_vm_operations() const { 839 return true; // May need to deoptimize 840 } 841 842 843 VM_GetReceiver::VM_GetReceiver( 844 JavaThread* thread, JavaThread* caller_thread, jint depth) 845 : VM_GetOrSetLocal(thread, caller_thread, depth, 0) {} 846 847 ///////////////////////////////////////////////////////////////////////////////////////// 848 849 // 850 // class JvmtiSuspendControl - see comments in jvmtiImpl.hpp 851 // 852 853 bool JvmtiSuspendControl::suspend(JavaThread *java_thread) { 854 // external suspend should have caught suspending a thread twice 855 856 // Immediate suspension required for JPDA back-end so JVMTI agent threads do 857 // not deadlock due to later suspension on transitions while holding 858 // raw monitors. Passing true causes the immediate suspension. 859 // java_suspend() will catch threads in the process of exiting 860 // and will ignore them. 861 java_thread->java_suspend(); 862 863 // It would be nice to have the following assertion in all the time, 864 // but it is possible for a racing resume request to have resumed 865 // this thread right after we suspended it. Temporarily enable this 866 // assertion if you are chasing a different kind of bug. 867 // 868 // assert(java_lang_Thread::thread(java_thread->threadObj()) == NULL || 869 // java_thread->is_being_ext_suspended(), "thread is not suspended"); 870 871 if (java_lang_Thread::thread(java_thread->threadObj()) == NULL) { 872 // check again because we can get delayed in java_suspend(): 873 // the thread is in process of exiting. 874 return false; 875 } 876 877 return true; 878 } 879 880 bool JvmtiSuspendControl::resume(JavaThread *java_thread) { 881 // external suspend should have caught resuming a thread twice 882 assert(java_thread->is_being_ext_suspended(), "thread should be suspended"); 883 884 // resume thread 885 { 886 // must always grab Threads_lock, see JVM_SuspendThread 887 MutexLocker ml(Threads_lock); 888 java_thread->java_resume(); 889 } 890 891 return true; 892 } 893 894 895 void JvmtiSuspendControl::print() { 896 #ifndef PRODUCT 897 MutexLocker mu(Threads_lock); 898 ResourceMark rm; 899 900 tty->print("Suspended Threads: ["); 901 for (JavaThread *thread = Threads::first(); thread != NULL; thread = thread->next()) { 902 #if JVMTI_TRACE 903 const char *name = JvmtiTrace::safe_get_thread_name(thread); 904 #else 905 const char *name = ""; 906 #endif /*JVMTI_TRACE */ 907 tty->print("%s(%c ", name, thread->is_being_ext_suspended() ? 'S' : '_'); 908 if (!thread->has_last_Java_frame()) { 909 tty->print("no stack"); 910 } 911 tty->print(") "); 912 } 913 tty->print_cr("]"); 914 #endif 915 } 916 917 #ifndef KERNEL 918 919 JvmtiDeferredEvent JvmtiDeferredEvent::compiled_method_load_event( 920 nmethod* nm) { 921 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_COMPILED_METHOD_LOAD); 922 event._event_data.compiled_method_load = nm; 923 // Keep the nmethod alive until the ServiceThread can process 924 // this deferred event. 925 nmethodLocker::lock_nmethod(nm); 926 return event; 927 } 928 929 JvmtiDeferredEvent JvmtiDeferredEvent::compiled_method_unload_event( 930 nmethod* nm, jmethodID id, const void* code) { 931 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_COMPILED_METHOD_UNLOAD); 932 event._event_data.compiled_method_unload.nm = nm; 933 event._event_data.compiled_method_unload.method_id = id; 934 event._event_data.compiled_method_unload.code_begin = code; 935 // Keep the nmethod alive until the ServiceThread can process 936 // this deferred event. This will keep the memory for the 937 // generated code from being reused too early. We pass 938 // zombie_ok == true here so that our nmethod that was just 939 // made into a zombie can be locked. 940 nmethodLocker::lock_nmethod(nm, true /* zombie_ok */); 941 return event; 942 } 943 944 JvmtiDeferredEvent JvmtiDeferredEvent::dynamic_code_generated_event( 945 const char* name, const void* code_begin, const void* code_end) { 946 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_DYNAMIC_CODE_GENERATED); 947 // Need to make a copy of the name since we don't know how long 948 // the event poster will keep it around after we enqueue the 949 // deferred event and return. strdup() failure is handled in 950 // the post() routine below. 951 event._event_data.dynamic_code_generated.name = os::strdup(name); 952 event._event_data.dynamic_code_generated.code_begin = code_begin; 953 event._event_data.dynamic_code_generated.code_end = code_end; 954 return event; 955 } 956 957 void JvmtiDeferredEvent::post() { 958 assert(ServiceThread::is_service_thread(Thread::current()), 959 "Service thread must post enqueued events"); 960 switch(_type) { 961 case TYPE_COMPILED_METHOD_LOAD: { 962 nmethod* nm = _event_data.compiled_method_load; 963 JvmtiExport::post_compiled_method_load(nm); 964 // done with the deferred event so unlock the nmethod 965 nmethodLocker::unlock_nmethod(nm); 966 break; 967 } 968 case TYPE_COMPILED_METHOD_UNLOAD: { 969 nmethod* nm = _event_data.compiled_method_unload.nm; 970 JvmtiExport::post_compiled_method_unload( 971 _event_data.compiled_method_unload.method_id, 972 _event_data.compiled_method_unload.code_begin); 973 // done with the deferred event so unlock the nmethod 974 nmethodLocker::unlock_nmethod(nm); 975 break; 976 } 977 case TYPE_DYNAMIC_CODE_GENERATED: { 978 JvmtiExport::post_dynamic_code_generated_internal( 979 // if strdup failed give the event a default name 980 (_event_data.dynamic_code_generated.name == NULL) 981 ? "unknown_code" : _event_data.dynamic_code_generated.name, 982 _event_data.dynamic_code_generated.code_begin, 983 _event_data.dynamic_code_generated.code_end); 984 if (_event_data.dynamic_code_generated.name != NULL) { 985 // release our copy 986 os::free((void *)_event_data.dynamic_code_generated.name); 987 } 988 break; 989 } 990 default: 991 ShouldNotReachHere(); 992 } 993 } 994 995 JvmtiDeferredEventQueue::QueueNode* JvmtiDeferredEventQueue::_queue_tail = NULL; 996 JvmtiDeferredEventQueue::QueueNode* JvmtiDeferredEventQueue::_queue_head = NULL; 997 998 volatile JvmtiDeferredEventQueue::QueueNode* 999 JvmtiDeferredEventQueue::_pending_list = NULL; 1000 1001 bool JvmtiDeferredEventQueue::has_events() { 1002 assert(Service_lock->owned_by_self(), "Must own Service_lock"); 1003 return _queue_head != NULL || _pending_list != NULL; 1004 } 1005 1006 void JvmtiDeferredEventQueue::enqueue(const JvmtiDeferredEvent& event) { 1007 assert(Service_lock->owned_by_self(), "Must own Service_lock"); 1008 1009 process_pending_events(); 1010 1011 // Events get added to the end of the queue (and are pulled off the front). 1012 QueueNode* node = new QueueNode(event); 1013 if (_queue_tail == NULL) { 1014 _queue_tail = _queue_head = node; 1015 } else { 1016 assert(_queue_tail->next() == NULL, "Must be the last element in the list"); 1017 _queue_tail->set_next(node); 1018 _queue_tail = node; 1019 } 1020 1021 Service_lock->notify_all(); 1022 assert((_queue_head == NULL) == (_queue_tail == NULL), 1023 "Inconsistent queue markers"); 1024 } 1025 1026 JvmtiDeferredEvent JvmtiDeferredEventQueue::dequeue() { 1027 assert(Service_lock->owned_by_self(), "Must own Service_lock"); 1028 1029 process_pending_events(); 1030 1031 assert(_queue_head != NULL, "Nothing to dequeue"); 1032 1033 if (_queue_head == NULL) { 1034 // Just in case this happens in product; it shouldn't but let's not crash 1035 return JvmtiDeferredEvent(); 1036 } 1037 1038 QueueNode* node = _queue_head; 1039 _queue_head = _queue_head->next(); 1040 if (_queue_head == NULL) { 1041 _queue_tail = NULL; 1042 } 1043 1044 assert((_queue_head == NULL) == (_queue_tail == NULL), 1045 "Inconsistent queue markers"); 1046 1047 JvmtiDeferredEvent event = node->event(); 1048 delete node; 1049 return event; 1050 } 1051 1052 void JvmtiDeferredEventQueue::add_pending_event( 1053 const JvmtiDeferredEvent& event) { 1054 1055 QueueNode* node = new QueueNode(event); 1056 1057 bool success = false; 1058 QueueNode* prev_value = (QueueNode*)_pending_list; 1059 do { 1060 node->set_next(prev_value); 1061 prev_value = (QueueNode*)Atomic::cmpxchg_ptr( 1062 (void*)node, (volatile void*)&_pending_list, (void*)node->next()); 1063 } while (prev_value != node->next()); 1064 } 1065 1066 // This method transfers any events that were added by someone NOT holding 1067 // the lock into the mainline queue. 1068 void JvmtiDeferredEventQueue::process_pending_events() { 1069 assert(Service_lock->owned_by_self(), "Must own Service_lock"); 1070 1071 if (_pending_list != NULL) { 1072 QueueNode* head = 1073 (QueueNode*)Atomic::xchg_ptr(NULL, (volatile void*)&_pending_list); 1074 1075 assert((_queue_head == NULL) == (_queue_tail == NULL), 1076 "Inconsistent queue markers"); 1077 1078 if (head != NULL) { 1079 // Since we've treated the pending list as a stack (with newer 1080 // events at the beginning), we need to join the bottom of the stack 1081 // with the 'tail' of the queue in order to get the events in the 1082 // right order. We do this by reversing the pending list and appending 1083 // it to the queue. 1084 1085 QueueNode* new_tail = head; 1086 QueueNode* new_head = NULL; 1087 1088 // This reverses the list 1089 QueueNode* prev = new_tail; 1090 QueueNode* node = new_tail->next(); 1091 new_tail->set_next(NULL); 1092 while (node != NULL) { 1093 QueueNode* next = node->next(); 1094 node->set_next(prev); 1095 prev = node; 1096 node = next; 1097 } 1098 new_head = prev; 1099 1100 // Now append the new list to the queue 1101 if (_queue_tail != NULL) { 1102 _queue_tail->set_next(new_head); 1103 } else { // _queue_head == NULL 1104 _queue_head = new_head; 1105 } 1106 _queue_tail = new_tail; 1107 } 1108 } 1109 } 1110 1111 #endif // ndef KERNEL