jvmtiImpl.cpp revision 1798:fa83ab460c54
1/* 2 * Copyright (c) 2003, 2007, 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 "incls/_precompiled.incl" 26# include "incls/_jvmtiImpl.cpp.incl" 27 28// 29// class JvmtiAgentThread 30// 31// JavaThread used to wrap a thread started by an agent 32// using the JVMTI method RunAgentThread. 33// 34 35JvmtiAgentThread::JvmtiAgentThread(JvmtiEnv* env, jvmtiStartFunction start_fn, const void *start_arg) 36 : JavaThread(start_function_wrapper) { 37 _env = env; 38 _start_fn = start_fn; 39 _start_arg = start_arg; 40} 41 42void 43JvmtiAgentThread::start_function_wrapper(JavaThread *thread, TRAPS) { 44 // It is expected that any Agent threads will be created as 45 // Java Threads. If this is the case, notification of the creation 46 // of the thread is given in JavaThread::thread_main(). 47 assert(thread->is_Java_thread(), "debugger thread should be a Java Thread"); 48 assert(thread == JavaThread::current(), "sanity check"); 49 50 JvmtiAgentThread *dthread = (JvmtiAgentThread *)thread; 51 dthread->call_start_function(); 52} 53 54void 55JvmtiAgentThread::call_start_function() { 56 ThreadToNativeFromVM transition(this); 57 _start_fn(_env->jvmti_external(), jni_environment(), (void*)_start_arg); 58} 59 60 61// 62// class GrowableCache - private methods 63// 64 65void GrowableCache::recache() { 66 int len = _elements->length(); 67 68 FREE_C_HEAP_ARRAY(address, _cache); 69 _cache = NEW_C_HEAP_ARRAY(address,len+1); 70 71 for (int i=0; i<len; i++) { 72 _cache[i] = _elements->at(i)->getCacheValue(); 73 // 74 // The cache entry has gone bad. Without a valid frame pointer 75 // value, the entry is useless so we simply delete it in product 76 // mode. The call to remove() will rebuild the cache again 77 // without the bad entry. 78 // 79 if (_cache[i] == NULL) { 80 assert(false, "cannot recache NULL elements"); 81 remove(i); 82 return; 83 } 84 } 85 _cache[len] = NULL; 86 87 _listener_fun(_this_obj,_cache); 88} 89 90bool GrowableCache::equals(void* v, GrowableElement *e2) { 91 GrowableElement *e1 = (GrowableElement *) v; 92 assert(e1 != NULL, "e1 != NULL"); 93 assert(e2 != NULL, "e2 != NULL"); 94 95 return e1->equals(e2); 96} 97 98// 99// class GrowableCache - public methods 100// 101 102GrowableCache::GrowableCache() { 103 _this_obj = NULL; 104 _listener_fun = NULL; 105 _elements = NULL; 106 _cache = NULL; 107} 108 109GrowableCache::~GrowableCache() { 110 clear(); 111 delete _elements; 112 FREE_C_HEAP_ARRAY(address, _cache); 113} 114 115void GrowableCache::initialize(void *this_obj, void listener_fun(void *, address*) ) { 116 _this_obj = this_obj; 117 _listener_fun = listener_fun; 118 _elements = new (ResourceObj::C_HEAP) GrowableArray<GrowableElement*>(5,true); 119 recache(); 120} 121 122// number of elements in the collection 123int GrowableCache::length() { 124 return _elements->length(); 125} 126 127// get the value of the index element in the collection 128GrowableElement* GrowableCache::at(int index) { 129 GrowableElement *e = (GrowableElement *) _elements->at(index); 130 assert(e != NULL, "e != NULL"); 131 return e; 132} 133 134int GrowableCache::find(GrowableElement* e) { 135 return _elements->find(e, GrowableCache::equals); 136} 137 138// append a copy of the element to the end of the collection 139void GrowableCache::append(GrowableElement* e) { 140 GrowableElement *new_e = e->clone(); 141 _elements->append(new_e); 142 recache(); 143} 144 145// insert a copy of the element using lessthan() 146void GrowableCache::insert(GrowableElement* e) { 147 GrowableElement *new_e = e->clone(); 148 _elements->append(new_e); 149 150 int n = length()-2; 151 for (int i=n; i>=0; i--) { 152 GrowableElement *e1 = _elements->at(i); 153 GrowableElement *e2 = _elements->at(i+1); 154 if (e2->lessThan(e1)) { 155 _elements->at_put(i+1, e1); 156 _elements->at_put(i, e2); 157 } 158 } 159 160 recache(); 161} 162 163// remove the element at index 164void GrowableCache::remove (int index) { 165 GrowableElement *e = _elements->at(index); 166 assert(e != NULL, "e != NULL"); 167 _elements->remove(e); 168 delete e; 169 recache(); 170} 171 172// clear out all elements, release all heap space and 173// let our listener know that things have changed. 174void GrowableCache::clear() { 175 int len = _elements->length(); 176 for (int i=0; i<len; i++) { 177 delete _elements->at(i); 178 } 179 _elements->clear(); 180 recache(); 181} 182 183void GrowableCache::oops_do(OopClosure* f) { 184 int len = _elements->length(); 185 for (int i=0; i<len; i++) { 186 GrowableElement *e = _elements->at(i); 187 e->oops_do(f); 188 } 189} 190 191void GrowableCache::gc_epilogue() { 192 int len = _elements->length(); 193 // recompute the new cache value after GC 194 for (int i=0; i<len; i++) { 195 _cache[i] = _elements->at(i)->getCacheValue(); 196 } 197} 198 199// 200// class JvmtiBreakpoint 201// 202 203JvmtiBreakpoint::JvmtiBreakpoint() { 204 _method = NULL; 205 _bci = 0; 206#ifdef CHECK_UNHANDLED_OOPS 207 // This one is always allocated with new, but check it just in case. 208 Thread *thread = Thread::current(); 209 if (thread->is_in_stack((address)&_method)) { 210 thread->allow_unhandled_oop((oop*)&_method); 211 } 212#endif // CHECK_UNHANDLED_OOPS 213} 214 215JvmtiBreakpoint::JvmtiBreakpoint(methodOop m_method, jlocation location) { 216 _method = m_method; 217 assert(_method != NULL, "_method != NULL"); 218 _bci = (int) location; 219#ifdef CHECK_UNHANDLED_OOPS 220 // Could be allocated with new and wouldn't be on the unhandled oop list. 221 Thread *thread = Thread::current(); 222 if (thread->is_in_stack((address)&_method)) { 223 thread->allow_unhandled_oop(&_method); 224 } 225#endif // CHECK_UNHANDLED_OOPS 226 227 assert(_bci >= 0, "_bci >= 0"); 228} 229 230void JvmtiBreakpoint::copy(JvmtiBreakpoint& bp) { 231 _method = bp._method; 232 _bci = bp._bci; 233} 234 235bool JvmtiBreakpoint::lessThan(JvmtiBreakpoint& bp) { 236 Unimplemented(); 237 return false; 238} 239 240bool JvmtiBreakpoint::equals(JvmtiBreakpoint& bp) { 241 return _method == bp._method 242 && _bci == bp._bci; 243} 244 245bool JvmtiBreakpoint::is_valid() { 246 return _method != NULL && 247 _bci >= 0; 248} 249 250address JvmtiBreakpoint::getBcp() { 251 return _method->bcp_from(_bci); 252} 253 254void JvmtiBreakpoint::each_method_version_do(method_action meth_act) { 255 ((methodOopDesc*)_method->*meth_act)(_bci); 256 257 // add/remove breakpoint to/from versions of the method that 258 // are EMCP. Directly or transitively obsolete methods are 259 // not saved in the PreviousVersionInfo. 260 Thread *thread = Thread::current(); 261 instanceKlassHandle ikh = instanceKlassHandle(thread, _method->method_holder()); 262 symbolOop m_name = _method->name(); 263 symbolOop m_signature = _method->signature(); 264 265 { 266 ResourceMark rm(thread); 267 // PreviousVersionInfo objects returned via PreviousVersionWalker 268 // contain a GrowableArray of handles. We have to clean up the 269 // GrowableArray _after_ the PreviousVersionWalker destructor 270 // has destroyed the handles. 271 { 272 // search previous versions if they exist 273 PreviousVersionWalker pvw((instanceKlass *)ikh()->klass_part()); 274 for (PreviousVersionInfo * pv_info = pvw.next_previous_version(); 275 pv_info != NULL; pv_info = pvw.next_previous_version()) { 276 GrowableArray<methodHandle>* methods = 277 pv_info->prev_EMCP_method_handles(); 278 279 if (methods == NULL) { 280 // We have run into a PreviousVersion generation where 281 // all methods were made obsolete during that generation's 282 // RedefineClasses() operation. At the time of that 283 // operation, all EMCP methods were flushed so we don't 284 // have to go back any further. 285 // 286 // A NULL methods array is different than an empty methods 287 // array. We cannot infer any optimizations about older 288 // generations from an empty methods array for the current 289 // generation. 290 break; 291 } 292 293 for (int i = methods->length() - 1; i >= 0; i--) { 294 methodHandle method = methods->at(i); 295 if (method->name() == m_name && method->signature() == m_signature) { 296 RC_TRACE(0x00000800, ("%sing breakpoint in %s(%s)", 297 meth_act == &methodOopDesc::set_breakpoint ? "sett" : "clear", 298 method->name()->as_C_string(), 299 method->signature()->as_C_string())); 300 assert(!method->is_obsolete(), "only EMCP methods here"); 301 302 ((methodOopDesc*)method()->*meth_act)(_bci); 303 break; 304 } 305 } 306 } 307 } // pvw is cleaned up 308 } // rm is cleaned up 309} 310 311void JvmtiBreakpoint::set() { 312 each_method_version_do(&methodOopDesc::set_breakpoint); 313} 314 315void JvmtiBreakpoint::clear() { 316 each_method_version_do(&methodOopDesc::clear_breakpoint); 317} 318 319void JvmtiBreakpoint::print() { 320#ifndef PRODUCT 321 const char *class_name = (_method == NULL) ? "NULL" : _method->klass_name()->as_C_string(); 322 const char *method_name = (_method == NULL) ? "NULL" : _method->name()->as_C_string(); 323 324 tty->print("Breakpoint(%s,%s,%d,%p)",class_name, method_name, _bci, getBcp()); 325#endif 326} 327 328 329// 330// class VM_ChangeBreakpoints 331// 332// Modify the Breakpoints data structure at a safepoint 333// 334 335void VM_ChangeBreakpoints::doit() { 336 switch (_operation) { 337 case SET_BREAKPOINT: 338 _breakpoints->set_at_safepoint(*_bp); 339 break; 340 case CLEAR_BREAKPOINT: 341 _breakpoints->clear_at_safepoint(*_bp); 342 break; 343 case CLEAR_ALL_BREAKPOINT: 344 _breakpoints->clearall_at_safepoint(); 345 break; 346 default: 347 assert(false, "Unknown operation"); 348 } 349} 350 351void VM_ChangeBreakpoints::oops_do(OopClosure* f) { 352 // This operation keeps breakpoints alive 353 if (_breakpoints != NULL) { 354 _breakpoints->oops_do(f); 355 } 356 if (_bp != NULL) { 357 _bp->oops_do(f); 358 } 359} 360 361// 362// class JvmtiBreakpoints 363// 364// a JVMTI internal collection of JvmtiBreakpoint 365// 366 367JvmtiBreakpoints::JvmtiBreakpoints(void listener_fun(void *,address *)) { 368 _bps.initialize(this,listener_fun); 369} 370 371JvmtiBreakpoints:: ~JvmtiBreakpoints() {} 372 373void JvmtiBreakpoints::oops_do(OopClosure* f) { 374 _bps.oops_do(f); 375} 376 377void JvmtiBreakpoints::gc_epilogue() { 378 _bps.gc_epilogue(); 379} 380 381void JvmtiBreakpoints::print() { 382#ifndef PRODUCT 383 ResourceMark rm; 384 385 int n = _bps.length(); 386 for (int i=0; i<n; i++) { 387 JvmtiBreakpoint& bp = _bps.at(i); 388 tty->print("%d: ", i); 389 bp.print(); 390 tty->print_cr(""); 391 } 392#endif 393} 394 395 396void JvmtiBreakpoints::set_at_safepoint(JvmtiBreakpoint& bp) { 397 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint"); 398 399 int i = _bps.find(bp); 400 if (i == -1) { 401 _bps.append(bp); 402 bp.set(); 403 } 404} 405 406void JvmtiBreakpoints::clear_at_safepoint(JvmtiBreakpoint& bp) { 407 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint"); 408 409 int i = _bps.find(bp); 410 if (i != -1) { 411 _bps.remove(i); 412 bp.clear(); 413 } 414} 415 416void JvmtiBreakpoints::clearall_at_safepoint() { 417 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint"); 418 419 int len = _bps.length(); 420 for (int i=0; i<len; i++) { 421 _bps.at(i).clear(); 422 } 423 _bps.clear(); 424} 425 426int JvmtiBreakpoints::length() { return _bps.length(); } 427 428int JvmtiBreakpoints::set(JvmtiBreakpoint& bp) { 429 if ( _bps.find(bp) != -1) { 430 return JVMTI_ERROR_DUPLICATE; 431 } 432 VM_ChangeBreakpoints set_breakpoint(this,VM_ChangeBreakpoints::SET_BREAKPOINT, &bp); 433 VMThread::execute(&set_breakpoint); 434 return JVMTI_ERROR_NONE; 435} 436 437int JvmtiBreakpoints::clear(JvmtiBreakpoint& bp) { 438 if ( _bps.find(bp) == -1) { 439 return JVMTI_ERROR_NOT_FOUND; 440 } 441 442 VM_ChangeBreakpoints clear_breakpoint(this,VM_ChangeBreakpoints::CLEAR_BREAKPOINT, &bp); 443 VMThread::execute(&clear_breakpoint); 444 return JVMTI_ERROR_NONE; 445} 446 447void JvmtiBreakpoints::clearall_in_class_at_safepoint(klassOop klass) { 448 bool changed = true; 449 // We are going to run thru the list of bkpts 450 // and delete some. This deletion probably alters 451 // the list in some implementation defined way such 452 // that when we delete entry i, the next entry might 453 // no longer be at i+1. To be safe, each time we delete 454 // an entry, we'll just start again from the beginning. 455 // We'll stop when we make a pass thru the whole list without 456 // deleting anything. 457 while (changed) { 458 int len = _bps.length(); 459 changed = false; 460 for (int i = 0; i < len; i++) { 461 JvmtiBreakpoint& bp = _bps.at(i); 462 if (bp.method()->method_holder() == klass) { 463 bp.clear(); 464 _bps.remove(i); 465 // This changed 'i' so we have to start over. 466 changed = true; 467 break; 468 } 469 } 470 } 471} 472 473void JvmtiBreakpoints::clearall() { 474 VM_ChangeBreakpoints clearall_breakpoint(this,VM_ChangeBreakpoints::CLEAR_ALL_BREAKPOINT); 475 VMThread::execute(&clearall_breakpoint); 476} 477 478// 479// class JvmtiCurrentBreakpoints 480// 481 482JvmtiBreakpoints *JvmtiCurrentBreakpoints::_jvmti_breakpoints = NULL; 483address * JvmtiCurrentBreakpoints::_breakpoint_list = NULL; 484 485 486JvmtiBreakpoints& 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 493void 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 504void JvmtiCurrentBreakpoints::oops_do(OopClosure* f) { 505 if (_jvmti_breakpoints != NULL) { 506 _jvmti_breakpoints->oops_do(f); 507 } 508} 509 510void JvmtiCurrentBreakpoints::gc_epilogue() { 511 if (_jvmti_breakpoints != NULL) { 512 _jvmti_breakpoints->gc_epilogue(); 513 } 514} 515 516 517/////////////////////////////////////////////////////////////// 518// 519// class VM_GetOrSetLocal 520// 521 522// Constructor for non-object getter 523VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, jint depth, int index, BasicType type) 524 : _thread(thread) 525 , _calling_thread(NULL) 526 , _depth(depth) 527 , _index(index) 528 , _type(type) 529 , _set(false) 530 , _jvf(NULL) 531 , _result(JVMTI_ERROR_NONE) 532{ 533} 534 535// Constructor for object or non-object setter 536VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, jint depth, int index, BasicType type, jvalue value) 537 : _thread(thread) 538 , _calling_thread(NULL) 539 , _depth(depth) 540 , _index(index) 541 , _type(type) 542 , _value(value) 543 , _set(true) 544 , _jvf(NULL) 545 , _result(JVMTI_ERROR_NONE) 546{ 547} 548 549// Constructor for object getter 550VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, JavaThread* calling_thread, jint depth, int index) 551 : _thread(thread) 552 , _calling_thread(calling_thread) 553 , _depth(depth) 554 , _index(index) 555 , _type(T_OBJECT) 556 , _set(false) 557 , _jvf(NULL) 558 , _result(JVMTI_ERROR_NONE) 559{ 560} 561 562 563vframe *VM_GetOrSetLocal::get_vframe() { 564 if (!_thread->has_last_Java_frame()) { 565 return NULL; 566 } 567 RegisterMap reg_map(_thread); 568 vframe *vf = _thread->last_java_vframe(®_map); 569 int d = 0; 570 while ((vf != NULL) && (d < _depth)) { 571 vf = vf->java_sender(); 572 d++; 573 } 574 return vf; 575} 576 577javaVFrame *VM_GetOrSetLocal::get_java_vframe() { 578 vframe* vf = get_vframe(); 579 if (vf == NULL) { 580 _result = JVMTI_ERROR_NO_MORE_FRAMES; 581 return NULL; 582 } 583 javaVFrame *jvf = (javaVFrame*)vf; 584 585 if (!vf->is_java_frame() || jvf->method()->is_native()) { 586 _result = JVMTI_ERROR_OPAQUE_FRAME; 587 return NULL; 588 } 589 return jvf; 590} 591 592// Check that the klass is assignable to a type with the given signature. 593// Another solution could be to use the function Klass::is_subtype_of(type). 594// But the type class can be forced to load/initialize eagerly in such a case. 595// This may cause unexpected consequences like CFLH or class-init JVMTI events. 596// It is better to avoid such a behavior. 597bool VM_GetOrSetLocal::is_assignable(const char* ty_sign, Klass* klass, Thread* thread) { 598 assert(ty_sign != NULL, "type signature must not be NULL"); 599 assert(thread != NULL, "thread must not be NULL"); 600 assert(klass != NULL, "klass must not be NULL"); 601 602 int len = (int) strlen(ty_sign); 603 if (ty_sign[0] == 'L' && ty_sign[len-1] == ';') { // Need pure class/interface name 604 ty_sign++; 605 len -= 2; 606 } 607 symbolHandle ty_sym = oopFactory::new_symbol_handle(ty_sign, len, thread); 608 if (klass->name() == ty_sym()) { 609 return true; 610 } 611 // Compare primary supers 612 int super_depth = klass->super_depth(); 613 int idx; 614 for (idx = 0; idx < super_depth; idx++) { 615 if (Klass::cast(klass->primary_super_of_depth(idx))->name() == ty_sym()) { 616 return true; 617 } 618 } 619 // Compare secondary supers 620 objArrayOop sec_supers = klass->secondary_supers(); 621 for (idx = 0; idx < sec_supers->length(); idx++) { 622 if (Klass::cast((klassOop) sec_supers->obj_at(idx))->name() == ty_sym()) { 623 return true; 624 } 625 } 626 return false; 627} 628 629// Checks error conditions: 630// JVMTI_ERROR_INVALID_SLOT 631// JVMTI_ERROR_TYPE_MISMATCH 632// Returns: 'true' - everything is Ok, 'false' - error code 633 634bool VM_GetOrSetLocal::check_slot_type(javaVFrame* jvf) { 635 methodOop method_oop = jvf->method(); 636 if (!method_oop->has_localvariable_table()) { 637 // Just to check index boundaries 638 jint extra_slot = (_type == T_LONG || _type == T_DOUBLE) ? 1 : 0; 639 if (_index < 0 || _index + extra_slot >= method_oop->max_locals()) { 640 _result = JVMTI_ERROR_INVALID_SLOT; 641 return false; 642 } 643 return true; 644 } 645 646 jint num_entries = method_oop->localvariable_table_length(); 647 if (num_entries == 0) { 648 _result = JVMTI_ERROR_INVALID_SLOT; 649 return false; // There are no slots 650 } 651 int signature_idx = -1; 652 int vf_bci = jvf->bci(); 653 LocalVariableTableElement* table = method_oop->localvariable_table_start(); 654 for (int i = 0; i < num_entries; i++) { 655 int start_bci = table[i].start_bci; 656 int end_bci = start_bci + table[i].length; 657 658 // Here we assume that locations of LVT entries 659 // with the same slot number cannot be overlapped 660 if (_index == (jint) table[i].slot && start_bci <= vf_bci && vf_bci <= end_bci) { 661 signature_idx = (int) table[i].descriptor_cp_index; 662 break; 663 } 664 } 665 if (signature_idx == -1) { 666 _result = JVMTI_ERROR_INVALID_SLOT; 667 return false; // Incorrect slot index 668 } 669 symbolOop sign_sym = method_oop->constants()->symbol_at(signature_idx); 670 const char* signature = (const char *) sign_sym->as_utf8(); 671 BasicType slot_type = char2type(signature[0]); 672 673 switch (slot_type) { 674 case T_BYTE: 675 case T_SHORT: 676 case T_CHAR: 677 case T_BOOLEAN: 678 slot_type = T_INT; 679 break; 680 case T_ARRAY: 681 slot_type = T_OBJECT; 682 break; 683 }; 684 if (_type != slot_type) { 685 _result = JVMTI_ERROR_TYPE_MISMATCH; 686 return false; 687 } 688 689 jobject jobj = _value.l; 690 if (_set && slot_type == T_OBJECT && jobj != NULL) { // NULL reference is allowed 691 // Check that the jobject class matches the return type signature. 692 JavaThread* cur_thread = JavaThread::current(); 693 HandleMark hm(cur_thread); 694 695 Handle obj = Handle(cur_thread, JNIHandles::resolve_external_guard(jobj)); 696 NULL_CHECK(obj, (_result = JVMTI_ERROR_INVALID_OBJECT, false)); 697 KlassHandle ob_kh = KlassHandle(cur_thread, obj->klass()); 698 NULL_CHECK(ob_kh, (_result = JVMTI_ERROR_INVALID_OBJECT, false)); 699 700 if (!is_assignable(signature, Klass::cast(ob_kh()), cur_thread)) { 701 _result = JVMTI_ERROR_TYPE_MISMATCH; 702 return false; 703 } 704 } 705 return true; 706} 707 708static bool can_be_deoptimized(vframe* vf) { 709 return (vf->is_compiled_frame() && vf->fr().can_be_deoptimized()); 710} 711 712bool VM_GetOrSetLocal::doit_prologue() { 713 _jvf = get_java_vframe(); 714 NULL_CHECK(_jvf, false); 715 716 if (!check_slot_type(_jvf)) { 717 return false; 718 } 719 return true; 720} 721 722void VM_GetOrSetLocal::doit() { 723 if (_set) { 724 // Force deoptimization of frame if compiled because it's 725 // possible the compiler emitted some locals as constant values, 726 // meaning they are not mutable. 727 if (can_be_deoptimized(_jvf)) { 728 729 // Schedule deoptimization so that eventually the local 730 // update will be written to an interpreter frame. 731 VM_DeoptimizeFrame deopt(_jvf->thread(), _jvf->fr().id()); 732 VMThread::execute(&deopt); 733 734 // Now store a new value for the local which will be applied 735 // once deoptimization occurs. Note however that while this 736 // write is deferred until deoptimization actually happens 737 // can vframe created after this point will have its locals 738 // reflecting this update so as far as anyone can see the 739 // write has already taken place. 740 741 // If we are updating an oop then get the oop from the handle 742 // since the handle will be long gone by the time the deopt 743 // happens. The oop stored in the deferred local will be 744 // gc'd on its own. 745 if (_type == T_OBJECT) { 746 _value.l = (jobject) (JNIHandles::resolve_external_guard(_value.l)); 747 } 748 // Re-read the vframe so we can see that it is deoptimized 749 // [ Only need because of assert in update_local() ] 750 _jvf = get_java_vframe(); 751 ((compiledVFrame*)_jvf)->update_local(_type, _index, _value); 752 return; 753 } 754 StackValueCollection *locals = _jvf->locals(); 755 HandleMark hm; 756 757 switch (_type) { 758 case T_INT: locals->set_int_at (_index, _value.i); break; 759 case T_LONG: locals->set_long_at (_index, _value.j); break; 760 case T_FLOAT: locals->set_float_at (_index, _value.f); break; 761 case T_DOUBLE: locals->set_double_at(_index, _value.d); break; 762 case T_OBJECT: { 763 Handle ob_h(JNIHandles::resolve_external_guard(_value.l)); 764 locals->set_obj_at (_index, ob_h); 765 break; 766 } 767 default: ShouldNotReachHere(); 768 } 769 _jvf->set_locals(locals); 770 } else { 771 StackValueCollection *locals = _jvf->locals(); 772 773 if (locals->at(_index)->type() == T_CONFLICT) { 774 memset(&_value, 0, sizeof(_value)); 775 _value.l = NULL; 776 return; 777 } 778 779 switch (_type) { 780 case T_INT: _value.i = locals->int_at (_index); break; 781 case T_LONG: _value.j = locals->long_at (_index); break; 782 case T_FLOAT: _value.f = locals->float_at (_index); break; 783 case T_DOUBLE: _value.d = locals->double_at(_index); break; 784 case T_OBJECT: { 785 // Wrap the oop to be returned in a local JNI handle since 786 // oops_do() no longer applies after doit() is finished. 787 oop obj = locals->obj_at(_index)(); 788 _value.l = JNIHandles::make_local(_calling_thread, obj); 789 break; 790 } 791 default: ShouldNotReachHere(); 792 } 793 } 794} 795 796 797bool VM_GetOrSetLocal::allow_nested_vm_operations() const { 798 return true; // May need to deoptimize 799} 800 801 802///////////////////////////////////////////////////////////////////////////////////////// 803 804// 805// class JvmtiSuspendControl - see comments in jvmtiImpl.hpp 806// 807 808bool JvmtiSuspendControl::suspend(JavaThread *java_thread) { 809 // external suspend should have caught suspending a thread twice 810 811 // Immediate suspension required for JPDA back-end so JVMTI agent threads do 812 // not deadlock due to later suspension on transitions while holding 813 // raw monitors. Passing true causes the immediate suspension. 814 // java_suspend() will catch threads in the process of exiting 815 // and will ignore them. 816 java_thread->java_suspend(); 817 818 // It would be nice to have the following assertion in all the time, 819 // but it is possible for a racing resume request to have resumed 820 // this thread right after we suspended it. Temporarily enable this 821 // assertion if you are chasing a different kind of bug. 822 // 823 // assert(java_lang_Thread::thread(java_thread->threadObj()) == NULL || 824 // java_thread->is_being_ext_suspended(), "thread is not suspended"); 825 826 if (java_lang_Thread::thread(java_thread->threadObj()) == NULL) { 827 // check again because we can get delayed in java_suspend(): 828 // the thread is in process of exiting. 829 return false; 830 } 831 832 return true; 833} 834 835bool JvmtiSuspendControl::resume(JavaThread *java_thread) { 836 // external suspend should have caught resuming a thread twice 837 assert(java_thread->is_being_ext_suspended(), "thread should be suspended"); 838 839 // resume thread 840 { 841 // must always grab Threads_lock, see JVM_SuspendThread 842 MutexLocker ml(Threads_lock); 843 java_thread->java_resume(); 844 } 845 846 return true; 847} 848 849 850void JvmtiSuspendControl::print() { 851#ifndef PRODUCT 852 MutexLocker mu(Threads_lock); 853 ResourceMark rm; 854 855 tty->print("Suspended Threads: ["); 856 for (JavaThread *thread = Threads::first(); thread != NULL; thread = thread->next()) { 857#if JVMTI_TRACE 858 const char *name = JvmtiTrace::safe_get_thread_name(thread); 859#else 860 const char *name = ""; 861#endif /*JVMTI_TRACE */ 862 tty->print("%s(%c ", name, thread->is_being_ext_suspended() ? 'S' : '_'); 863 if (!thread->has_last_Java_frame()) { 864 tty->print("no stack"); 865 } 866 tty->print(") "); 867 } 868 tty->print_cr("]"); 869#endif 870} 871