1 /*
   2  * Copyright (c) 2003, 2019, 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/symbolTable.hpp"
  27 #include "classfile/systemDictionary.hpp"
  28 #include "interpreter/interpreter.hpp"
  29 #include "interpreter/oopMapCache.hpp"
  30 #include "jvmtifiles/jvmtiEnv.hpp"
  31 #include "logging/log.hpp"
  32 #include "logging/logStream.hpp"
  33 #include "memory/allocation.inline.hpp"
  34 #include "memory/resourceArea.hpp"
  35 #include "oops/instanceKlass.hpp"
  36 #include "oops/oop.inline.hpp"
  37 #include "prims/jvmtiAgentThread.hpp"
  38 #include "prims/jvmtiEventController.inline.hpp"
  39 #include "prims/jvmtiImpl.hpp"
  40 #include "prims/jvmtiRedefineClasses.hpp"
  41 #include "runtime/atomic.hpp"
  42 #include "runtime/deoptimization.hpp"
  43 #include "runtime/frame.inline.hpp"
  44 #include "runtime/handles.inline.hpp"
  45 #include "runtime/interfaceSupport.inline.hpp"
  46 #include "runtime/javaCalls.hpp"
  47 #include "runtime/os.hpp"
  48 #include "runtime/serviceThread.hpp"
  49 #include "runtime/signature.hpp"
  50 #include "runtime/thread.inline.hpp"
  51 #include "runtime/threadSMR.hpp"
  52 #include "runtime/vframe.hpp"
  53 #include "runtime/vframe_hp.hpp"
  54 #include "runtime/vmOperations.hpp"
  55 #include "utilities/exceptions.hpp"
  56 
  57 //
  58 // class JvmtiAgentThread
  59 //
  60 // JavaThread used to wrap a thread started by an agent
  61 // using the JVMTI method RunAgentThread.
  62 //
  63 
  64 JvmtiAgentThread::JvmtiAgentThread(JvmtiEnv* env, jvmtiStartFunction start_fn, const void *start_arg)
  65     : JavaThread(start_function_wrapper) {
  66     _env = env;
  67     _start_fn = start_fn;
  68     _start_arg = start_arg;
  69 }
  70 
  71 void
  72 JvmtiAgentThread::start_function_wrapper(JavaThread *thread, TRAPS) {
  73     // It is expected that any Agent threads will be created as
  74     // Java Threads.  If this is the case, notification of the creation
  75     // of the thread is given in JavaThread::thread_main().
  76     assert(thread->is_Java_thread(), "debugger thread should be a Java Thread");
  77     assert(thread == JavaThread::current(), "sanity check");
  78 
  79     JvmtiAgentThread *dthread = (JvmtiAgentThread *)thread;
  80     dthread->call_start_function();
  81 }
  82 
  83 void
  84 JvmtiAgentThread::call_start_function() {
  85     ThreadToNativeFromVM transition(this);
  86     _start_fn(_env->jvmti_external(), jni_environment(), (void*)_start_arg);
  87 }
  88 
  89 
  90 //
  91 // class GrowableCache - private methods
  92 //
  93 
  94 void GrowableCache::recache() {
  95   int len = _elements->length();
  96 
  97   FREE_C_HEAP_ARRAY(address, _cache);
  98   _cache = NEW_C_HEAP_ARRAY(address,len+1, mtInternal);
  99 
 100   for (int i=0; i<len; i++) {
 101     _cache[i] = _elements->at(i)->getCacheValue();
 102     //
 103     // The cache entry has gone bad. Without a valid frame pointer
 104     // value, the entry is useless so we simply delete it in product
 105     // mode. The call to remove() will rebuild the cache again
 106     // without the bad entry.
 107     //
 108     if (_cache[i] == NULL) {
 109       assert(false, "cannot recache NULL elements");
 110       remove(i);
 111       return;
 112     }
 113   }
 114   _cache[len] = NULL;
 115 
 116   _listener_fun(_this_obj,_cache);
 117 }
 118 
 119 bool GrowableCache::equals(void* v, GrowableElement *e2) {
 120   GrowableElement *e1 = (GrowableElement *) v;
 121   assert(e1 != NULL, "e1 != NULL");
 122   assert(e2 != NULL, "e2 != NULL");
 123 
 124   return e1->equals(e2);
 125 }
 126 
 127 //
 128 // class GrowableCache - public methods
 129 //
 130 
 131 GrowableCache::GrowableCache() {
 132   _this_obj       = NULL;
 133   _listener_fun   = NULL;
 134   _elements       = NULL;
 135   _cache          = NULL;
 136 }
 137 
 138 GrowableCache::~GrowableCache() {
 139   clear();
 140   delete _elements;
 141   FREE_C_HEAP_ARRAY(address, _cache);
 142 }
 143 
 144 void GrowableCache::initialize(void *this_obj, void listener_fun(void *, address*) ) {
 145   _this_obj       = this_obj;
 146   _listener_fun   = listener_fun;
 147   _elements       = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<GrowableElement*>(5,true);
 148   recache();
 149 }
 150 
 151 // number of elements in the collection
 152 int GrowableCache::length() {
 153   return _elements->length();
 154 }
 155 
 156 // get the value of the index element in the collection
 157 GrowableElement* GrowableCache::at(int index) {
 158   GrowableElement *e = (GrowableElement *) _elements->at(index);
 159   assert(e != NULL, "e != NULL");
 160   return e;
 161 }
 162 
 163 int GrowableCache::find(GrowableElement* e) {
 164   return _elements->find(e, GrowableCache::equals);
 165 }
 166 
 167 // append a copy of the element to the end of the collection
 168 void GrowableCache::append(GrowableElement* e) {
 169   GrowableElement *new_e = e->clone();
 170   _elements->append(new_e);
 171   recache();
 172 }
 173 
 174 // insert a copy of the element using lessthan()
 175 void GrowableCache::insert(GrowableElement* e) {
 176   GrowableElement *new_e = e->clone();
 177   _elements->append(new_e);
 178 
 179   int n = length()-2;
 180   for (int i=n; i>=0; i--) {
 181     GrowableElement *e1 = _elements->at(i);
 182     GrowableElement *e2 = _elements->at(i+1);
 183     if (e2->lessThan(e1)) {
 184       _elements->at_put(i+1, e1);
 185       _elements->at_put(i,   e2);
 186     }
 187   }
 188 
 189   recache();
 190 }
 191 
 192 // remove the element at index
 193 void GrowableCache::remove (int index) {
 194   GrowableElement *e = _elements->at(index);
 195   assert(e != NULL, "e != NULL");
 196   _elements->remove(e);
 197   delete e;
 198   recache();
 199 }
 200 
 201 // clear out all elements, release all heap space and
 202 // let our listener know that things have changed.
 203 void GrowableCache::clear() {
 204   int len = _elements->length();
 205   for (int i=0; i<len; i++) {
 206     delete _elements->at(i);
 207   }
 208   _elements->clear();
 209   recache();
 210 }
 211 
 212 void GrowableCache::oops_do(OopClosure* f) {
 213   int len = _elements->length();
 214   for (int i=0; i<len; i++) {
 215     GrowableElement *e = _elements->at(i);
 216     e->oops_do(f);
 217   }
 218 }
 219 
 220 void GrowableCache::metadata_do(void f(Metadata*)) {
 221   int len = _elements->length();
 222   for (int i=0; i<len; i++) {
 223     GrowableElement *e = _elements->at(i);
 224     e->metadata_do(f);
 225   }
 226 }
 227 
 228 void GrowableCache::gc_epilogue() {
 229   int len = _elements->length();
 230   for (int i=0; i<len; i++) {
 231     _cache[i] = _elements->at(i)->getCacheValue();
 232   }
 233 }
 234 
 235 //
 236 // class JvmtiBreakpoint
 237 //
 238 
 239 JvmtiBreakpoint::JvmtiBreakpoint() {
 240   _method = NULL;
 241   _bci    = 0;
 242   _class_holder = NULL;
 243 }
 244 
 245 JvmtiBreakpoint::JvmtiBreakpoint(Method* m_method, jlocation location) {
 246   _method        = m_method;
 247   _class_holder  = _method->method_holder()->klass_holder();
 248 #ifdef CHECK_UNHANDLED_OOPS
 249   // _class_holder can't be wrapped in a Handle, because JvmtiBreakpoints are
 250   // sometimes allocated on the heap.
 251   //
 252   // The code handling JvmtiBreakpoints allocated on the stack can't be
 253   // interrupted by a GC until _class_holder is reachable by the GC via the
 254   // oops_do method.
 255   Thread::current()->allow_unhandled_oop(&_class_holder);
 256 #endif // CHECK_UNHANDLED_OOPS
 257   assert(_method != NULL, "_method != NULL");
 258   _bci           = (int) location;
 259   assert(_bci >= 0, "_bci >= 0");
 260 }
 261 
 262 void JvmtiBreakpoint::copy(JvmtiBreakpoint& bp) {
 263   _method   = bp._method;
 264   _bci      = bp._bci;
 265   _class_holder = bp._class_holder;
 266 }
 267 
 268 bool JvmtiBreakpoint::lessThan(JvmtiBreakpoint& bp) {
 269   Unimplemented();
 270   return false;
 271 }
 272 
 273 bool JvmtiBreakpoint::equals(JvmtiBreakpoint& bp) {
 274   return _method   == bp._method
 275     &&   _bci      == bp._bci;
 276 }
 277 
 278 bool JvmtiBreakpoint::is_valid() {
 279   // class loader can be NULL
 280   return _method != NULL &&
 281          _bci >= 0;
 282 }
 283 
 284 address JvmtiBreakpoint::getBcp() const {
 285   return _method->bcp_from(_bci);
 286 }
 287 
 288 void JvmtiBreakpoint::each_method_version_do(method_action meth_act) {
 289   ((Method*)_method->*meth_act)(_bci);
 290 
 291   // add/remove breakpoint to/from versions of the method that are EMCP.
 292   Thread *thread = Thread::current();
 293   InstanceKlass* ik = _method->method_holder();
 294   Symbol* m_name = _method->name();
 295   Symbol* m_signature = _method->signature();
 296 
 297   // search previous versions if they exist
 298   for (InstanceKlass* pv_node = ik->previous_versions();
 299        pv_node != NULL;
 300        pv_node = pv_node->previous_versions()) {
 301     Array<Method*>* methods = pv_node->methods();
 302 
 303     for (int i = methods->length() - 1; i >= 0; i--) {
 304       Method* method = methods->at(i);
 305       // Only set breakpoints in running EMCP methods.
 306       if (method->is_running_emcp() &&
 307           method->name() == m_name &&
 308           method->signature() == m_signature) {
 309         ResourceMark rm;
 310         log_debug(redefine, class, breakpoint)
 311           ("%sing breakpoint in %s(%s)", meth_act == &Method::set_breakpoint ? "sett" : "clear",
 312            method->name()->as_C_string(), method->signature()->as_C_string());
 313         (method->*meth_act)(_bci);
 314         break;
 315       }
 316     }
 317   }
 318 }
 319 
 320 void JvmtiBreakpoint::set() {
 321   each_method_version_do(&Method::set_breakpoint);
 322 }
 323 
 324 void JvmtiBreakpoint::clear() {
 325   each_method_version_do(&Method::clear_breakpoint);
 326 }
 327 
 328 void JvmtiBreakpoint::print_on(outputStream* out) const {
 329 #ifndef PRODUCT
 330   ResourceMark rm;
 331   const char *class_name  = (_method == NULL) ? "NULL" : _method->klass_name()->as_C_string();
 332   const char *method_name = (_method == NULL) ? "NULL" : _method->name()->as_C_string();
 333   out->print("Breakpoint(%s,%s,%d,%p)", class_name, method_name, _bci, getBcp());
 334 #endif
 335 }
 336 
 337 
 338 //
 339 // class VM_ChangeBreakpoints
 340 //
 341 // Modify the Breakpoints data structure at a safepoint
 342 //
 343 
 344 void VM_ChangeBreakpoints::doit() {
 345   switch (_operation) {
 346   case SET_BREAKPOINT:
 347     _breakpoints->set_at_safepoint(*_bp);
 348     break;
 349   case CLEAR_BREAKPOINT:
 350     _breakpoints->clear_at_safepoint(*_bp);
 351     break;
 352   default:
 353     assert(false, "Unknown operation");
 354   }
 355 }
 356 
 357 void VM_ChangeBreakpoints::oops_do(OopClosure* f) {
 358   // The JvmtiBreakpoints in _breakpoints will be visited via
 359   // JvmtiExport::oops_do.
 360   if (_bp != NULL) {
 361     _bp->oops_do(f);
 362   }
 363 }
 364 
 365 void VM_ChangeBreakpoints::metadata_do(void f(Metadata*)) {
 366   // Walk metadata in breakpoints to keep from being deallocated with RedefineClasses
 367   if (_bp != NULL) {
 368     _bp->metadata_do(f);
 369   }
 370 }
 371 
 372 //
 373 // class JvmtiBreakpoints
 374 //
 375 // a JVMTI internal collection of JvmtiBreakpoint
 376 //
 377 
 378 JvmtiBreakpoints::JvmtiBreakpoints(void listener_fun(void *,address *)) {
 379   _bps.initialize(this,listener_fun);
 380 }
 381 
 382 JvmtiBreakpoints:: ~JvmtiBreakpoints() {}
 383 
 384 void  JvmtiBreakpoints::oops_do(OopClosure* f) {
 385   _bps.oops_do(f);
 386 }
 387 
 388 void  JvmtiBreakpoints::metadata_do(void f(Metadata*)) {
 389   _bps.metadata_do(f);
 390 }
 391 
 392 void JvmtiBreakpoints::gc_epilogue() {
 393   _bps.gc_epilogue();
 394 }
 395 
 396 void JvmtiBreakpoints::print() {
 397 #ifndef PRODUCT
 398   LogTarget(Trace, jvmti) log;
 399   LogStream log_stream(log);
 400 
 401   int n = _bps.length();
 402   for (int i=0; i<n; i++) {
 403     JvmtiBreakpoint& bp = _bps.at(i);
 404     log_stream.print("%d: ", i);
 405     bp.print_on(&log_stream);
 406     log_stream.cr();
 407   }
 408 #endif
 409 }
 410 
 411 
 412 void JvmtiBreakpoints::set_at_safepoint(JvmtiBreakpoint& bp) {
 413   assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
 414 
 415   int i = _bps.find(bp);
 416   if (i == -1) {
 417     _bps.append(bp);
 418     bp.set();
 419   }
 420 }
 421 
 422 void JvmtiBreakpoints::clear_at_safepoint(JvmtiBreakpoint& bp) {
 423   assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
 424 
 425   int i = _bps.find(bp);
 426   if (i != -1) {
 427     _bps.remove(i);
 428     bp.clear();
 429   }
 430 }
 431 
 432 int JvmtiBreakpoints::length() { return _bps.length(); }
 433 
 434 int JvmtiBreakpoints::set(JvmtiBreakpoint& bp) {
 435   if ( _bps.find(bp) != -1) {
 436      return JVMTI_ERROR_DUPLICATE;
 437   }
 438   VM_ChangeBreakpoints set_breakpoint(VM_ChangeBreakpoints::SET_BREAKPOINT, &bp);
 439   VMThread::execute(&set_breakpoint);
 440   return JVMTI_ERROR_NONE;
 441 }
 442 
 443 int JvmtiBreakpoints::clear(JvmtiBreakpoint& bp) {
 444   if ( _bps.find(bp) == -1) {
 445      return JVMTI_ERROR_NOT_FOUND;
 446   }
 447 
 448   VM_ChangeBreakpoints clear_breakpoint(VM_ChangeBreakpoints::CLEAR_BREAKPOINT, &bp);
 449   VMThread::execute(&clear_breakpoint);
 450   return JVMTI_ERROR_NONE;
 451 }
 452 
 453 void JvmtiBreakpoints::clearall_in_class_at_safepoint(Klass* klass) {
 454   bool changed = true;
 455   // We are going to run thru the list of bkpts
 456   // and delete some.  This deletion probably alters
 457   // the list in some implementation defined way such
 458   // that when we delete entry i, the next entry might
 459   // no longer be at i+1.  To be safe, each time we delete
 460   // an entry, we'll just start again from the beginning.
 461   // We'll stop when we make a pass thru the whole list without
 462   // deleting anything.
 463   while (changed) {
 464     int len = _bps.length();
 465     changed = false;
 466     for (int i = 0; i < len; i++) {
 467       JvmtiBreakpoint& bp = _bps.at(i);
 468       if (bp.method()->method_holder() == klass) {
 469         bp.clear();
 470         _bps.remove(i);
 471         // This changed 'i' so we have to start over.
 472         changed = true;
 473         break;
 474       }
 475     }
 476   }
 477 }
 478 
 479 //
 480 // class JvmtiCurrentBreakpoints
 481 //
 482 
 483 JvmtiBreakpoints *JvmtiCurrentBreakpoints::_jvmti_breakpoints  = NULL;
 484 address *         JvmtiCurrentBreakpoints::_breakpoint_list    = NULL;
 485 
 486 
 487 JvmtiBreakpoints& JvmtiCurrentBreakpoints::get_jvmti_breakpoints() {
 488   if (_jvmti_breakpoints != NULL) return (*_jvmti_breakpoints);
 489   _jvmti_breakpoints = new JvmtiBreakpoints(listener_fun);
 490   assert(_jvmti_breakpoints != NULL, "_jvmti_breakpoints != NULL");
 491   return (*_jvmti_breakpoints);
 492 }
 493 
 494 void  JvmtiCurrentBreakpoints::listener_fun(void *this_obj, address *cache) {
 495   JvmtiBreakpoints *this_jvmti = (JvmtiBreakpoints *) this_obj;
 496   assert(this_jvmti != NULL, "this_jvmti != NULL");
 497 
 498   debug_only(int n = this_jvmti->length(););
 499   assert(cache[n] == NULL, "cache must be NULL terminated");
 500 
 501   set_breakpoint_list(cache);
 502 }
 503 
 504 
 505 void JvmtiCurrentBreakpoints::oops_do(OopClosure* f) {
 506   if (_jvmti_breakpoints != NULL) {
 507     _jvmti_breakpoints->oops_do(f);
 508   }
 509 }
 510 
 511 void JvmtiCurrentBreakpoints::metadata_do(void f(Metadata*)) {
 512   if (_jvmti_breakpoints != NULL) {
 513     _jvmti_breakpoints->metadata_do(f);
 514   }
 515 }
 516 
 517 void JvmtiCurrentBreakpoints::gc_epilogue() {
 518   if (_jvmti_breakpoints != NULL) {
 519     _jvmti_breakpoints->gc_epilogue();
 520   }
 521 }
 522 
 523 ///////////////////////////////////////////////////////////////
 524 //
 525 // class VM_GetOrSetLocal
 526 //
 527 
 528 // Constructor for non-object getter
 529 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, jint depth, jint index, BasicType type)
 530   : _thread(thread)
 531   , _calling_thread(NULL)
 532   , _depth(depth)
 533   , _index(index)
 534   , _type(type)
 535   , _jvf(NULL)
 536   , _set(false)
 537   , _result(JVMTI_ERROR_NONE)
 538 {
 539 }
 540 
 541 // Constructor for object or non-object setter
 542 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, jint depth, jint index, BasicType type, jvalue value)
 543   : _thread(thread)
 544   , _calling_thread(NULL)
 545   , _depth(depth)
 546   , _index(index)
 547   , _type(type)
 548   , _value(value)
 549   , _jvf(NULL)
 550   , _set(true)
 551   , _result(JVMTI_ERROR_NONE)
 552 {
 553 }
 554 
 555 // Constructor for object getter
 556 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, JavaThread* calling_thread, jint depth, int index)
 557   : _thread(thread)
 558   , _calling_thread(calling_thread)
 559   , _depth(depth)
 560   , _index(index)
 561   , _type(T_OBJECT)
 562   , _jvf(NULL)
 563   , _set(false)
 564   , _result(JVMTI_ERROR_NONE)
 565 {
 566 }
 567 
 568 vframe *VM_GetOrSetLocal::get_vframe() {
 569   if (!_thread->has_last_Java_frame()) {
 570     return NULL;
 571   }
 572   RegisterMap reg_map(_thread);
 573   vframe *vf = _thread->last_java_vframe(&reg_map);
 574   int d = 0;
 575   while ((vf != NULL) && (d < _depth)) {
 576     vf = vf->java_sender();
 577     d++;
 578   }
 579   return vf;
 580 }
 581 
 582 javaVFrame *VM_GetOrSetLocal::get_java_vframe() {
 583   vframe* vf = get_vframe();
 584   if (vf == NULL) {
 585     _result = JVMTI_ERROR_NO_MORE_FRAMES;
 586     return NULL;
 587   }
 588   javaVFrame *jvf = (javaVFrame*)vf;
 589 
 590   if (!vf->is_java_frame()) {
 591     _result = JVMTI_ERROR_OPAQUE_FRAME;
 592     return NULL;
 593   }
 594   return jvf;
 595 }
 596 
 597 // Check that the klass is assignable to a type with the given signature.
 598 // Another solution could be to use the function Klass::is_subtype_of(type).
 599 // But the type class can be forced to load/initialize eagerly in such a case.
 600 // This may cause unexpected consequences like CFLH or class-init JVMTI events.
 601 // It is better to avoid such a behavior.
 602 bool VM_GetOrSetLocal::is_assignable(const char* ty_sign, Klass* klass, Thread* thread) {
 603   assert(ty_sign != NULL, "type signature must not be NULL");
 604   assert(thread != NULL, "thread must not be NULL");
 605   assert(klass != NULL, "klass must not be NULL");
 606 
 607   int len = (int) strlen(ty_sign);
 608   if (ty_sign[0] == 'L' && ty_sign[len-1] == ';') { // Need pure class/interface name
 609     ty_sign++;
 610     len -= 2;
 611   }
 612   TempNewSymbol ty_sym = SymbolTable::new_symbol(ty_sign, len);
 613   if (klass->name() == ty_sym) {
 614     return true;
 615   }
 616   // Compare primary supers
 617   int super_depth = klass->super_depth();
 618   int idx;
 619   for (idx = 0; idx < super_depth; idx++) {
 620     if (klass->primary_super_of_depth(idx)->name() == ty_sym) {
 621       return true;
 622     }
 623   }
 624   // Compare secondary supers
 625   const Array<Klass*>* sec_supers = klass->secondary_supers();
 626   for (idx = 0; idx < sec_supers->length(); idx++) {
 627     if (((Klass*) sec_supers->at(idx))->name() == ty_sym) {
 628       return true;
 629     }
 630   }
 631   return false;
 632 }
 633 
 634 // Checks error conditions:
 635 //   JVMTI_ERROR_INVALID_SLOT
 636 //   JVMTI_ERROR_TYPE_MISMATCH
 637 // Returns: 'true' - everything is Ok, 'false' - error code
 638 
 639 bool VM_GetOrSetLocal::check_slot_type_lvt(javaVFrame* jvf) {
 640   Method* method_oop = jvf->method();
 641   jint num_entries = method_oop->localvariable_table_length();
 642   if (num_entries == 0) {
 643     _result = JVMTI_ERROR_INVALID_SLOT;
 644     return false;       // There are no slots
 645   }
 646   int signature_idx = -1;
 647   int vf_bci = jvf->bci();
 648   LocalVariableTableElement* table = method_oop->localvariable_table_start();
 649   for (int i = 0; i < num_entries; i++) {
 650     int start_bci = table[i].start_bci;
 651     int end_bci = start_bci + table[i].length;
 652 
 653     // Here we assume that locations of LVT entries
 654     // with the same slot number cannot be overlapped
 655     if (_index == (jint) table[i].slot && start_bci <= vf_bci && vf_bci <= end_bci) {
 656       signature_idx = (int) table[i].descriptor_cp_index;
 657       break;
 658     }
 659   }
 660   if (signature_idx == -1) {
 661     _result = JVMTI_ERROR_INVALID_SLOT;
 662     return false;       // Incorrect slot index
 663   }
 664   Symbol*   sign_sym  = method_oop->constants()->symbol_at(signature_idx);
 665   const char* signature = (const char *) sign_sym->as_utf8();
 666   BasicType slot_type = char2type(signature[0]);
 667 
 668   switch (slot_type) {
 669   case T_BYTE:
 670   case T_SHORT:
 671   case T_CHAR:
 672   case T_BOOLEAN:
 673     slot_type = T_INT;
 674     break;
 675   case T_ARRAY:
 676     slot_type = T_OBJECT;
 677     break;
 678   default:
 679     break;
 680   };
 681   if (_type != slot_type) {
 682     _result = JVMTI_ERROR_TYPE_MISMATCH;
 683     return false;
 684   }
 685 
 686   jobject jobj = _value.l;
 687   if (_set && slot_type == T_OBJECT && jobj != NULL) { // NULL reference is allowed
 688     // Check that the jobject class matches the return type signature.
 689     JavaThread* cur_thread = JavaThread::current();
 690     HandleMark hm(cur_thread);
 691 
 692     Handle obj(cur_thread, JNIHandles::resolve_external_guard(jobj));
 693     NULL_CHECK(obj, (_result = JVMTI_ERROR_INVALID_OBJECT, false));
 694     Klass* ob_k = obj->klass();
 695     NULL_CHECK(ob_k, (_result = JVMTI_ERROR_INVALID_OBJECT, false));
 696 
 697     if (!is_assignable(signature, ob_k, cur_thread)) {
 698       _result = JVMTI_ERROR_TYPE_MISMATCH;
 699       return false;
 700     }
 701   }
 702   return true;
 703 }
 704 
 705 bool VM_GetOrSetLocal::check_slot_type_no_lvt(javaVFrame* jvf) {
 706   Method* method_oop = jvf->method();
 707   jint extra_slot = (_type == T_LONG || _type == T_DOUBLE) ? 1 : 0;
 708 
 709   if (_index < 0 || _index + extra_slot >= method_oop->max_locals()) {
 710     _result = JVMTI_ERROR_INVALID_SLOT;
 711     return false;
 712   }
 713   StackValueCollection *locals = _jvf->locals();
 714   BasicType slot_type = locals->at(_index)->type();
 715 
 716   if (slot_type == T_CONFLICT) {
 717     _result = JVMTI_ERROR_INVALID_SLOT;
 718     return false;
 719   }
 720   if (extra_slot) {
 721     BasicType extra_slot_type = locals->at(_index + 1)->type();
 722     if (extra_slot_type != T_INT) {
 723       _result = JVMTI_ERROR_INVALID_SLOT;
 724       return false;
 725     }
 726   }
 727   if (_type != slot_type && (_type == T_OBJECT || slot_type != T_INT)) {
 728     _result = JVMTI_ERROR_TYPE_MISMATCH;
 729     return false;
 730   }
 731   return true;
 732 }
 733 
 734 static bool can_be_deoptimized(vframe* vf) {
 735   return (vf->is_compiled_frame() && vf->fr().can_be_deoptimized());
 736 }
 737 
 738 bool VM_GetOrSetLocal::doit_prologue() {
 739   _jvf = get_java_vframe();
 740   NULL_CHECK(_jvf, false);
 741 
 742   Method* method_oop = _jvf->method();
 743   if (method_oop->is_native()) {
 744     if (getting_receiver() && !method_oop->is_static()) {
 745       return true;
 746     } else {
 747       _result = JVMTI_ERROR_OPAQUE_FRAME;
 748       return false;
 749     }
 750   }
 751 
 752   if (!check_slot_type_no_lvt(_jvf)) {
 753     return false;
 754   }
 755   if (method_oop->has_localvariable_table()) {
 756     return check_slot_type_lvt(_jvf);
 757   }
 758   return true;
 759 }
 760 
 761 void VM_GetOrSetLocal::doit() {
 762   InterpreterOopMap oop_mask;
 763   _jvf->method()->mask_for(_jvf->bci(), &oop_mask);
 764   if (oop_mask.is_dead(_index)) {
 765     // The local can be invalid and uninitialized in the scope of current bci
 766     _result = JVMTI_ERROR_INVALID_SLOT;
 767     return;
 768   }
 769   if (_set) {
 770     // Force deoptimization of frame if compiled because it's
 771     // possible the compiler emitted some locals as constant values,
 772     // meaning they are not mutable.
 773     if (can_be_deoptimized(_jvf)) {
 774 
 775       // Schedule deoptimization so that eventually the local
 776       // update will be written to an interpreter frame.
 777       Deoptimization::deoptimize_frame(_jvf->thread(), _jvf->fr().id());
 778 
 779       // Now store a new value for the local which will be applied
 780       // once deoptimization occurs. Note however that while this
 781       // write is deferred until deoptimization actually happens
 782       // can vframe created after this point will have its locals
 783       // reflecting this update so as far as anyone can see the
 784       // write has already taken place.
 785 
 786       // If we are updating an oop then get the oop from the handle
 787       // since the handle will be long gone by the time the deopt
 788       // happens. The oop stored in the deferred local will be
 789       // gc'd on its own.
 790       if (_type == T_OBJECT) {
 791         _value.l = (jobject) (JNIHandles::resolve_external_guard(_value.l));
 792       }
 793       // Re-read the vframe so we can see that it is deoptimized
 794       // [ Only need because of assert in update_local() ]
 795       _jvf = get_java_vframe();
 796       ((compiledVFrame*)_jvf)->update_local(_type, _index, _value);
 797       return;
 798     }
 799     StackValueCollection *locals = _jvf->locals();
 800     HandleMark hm;
 801 
 802     switch (_type) {
 803       case T_INT:    locals->set_int_at   (_index, _value.i); break;
 804       case T_LONG:   locals->set_long_at  (_index, _value.j); break;
 805       case T_FLOAT:  locals->set_float_at (_index, _value.f); break;
 806       case T_DOUBLE: locals->set_double_at(_index, _value.d); break;
 807       case T_OBJECT: {
 808         Handle ob_h(Thread::current(), JNIHandles::resolve_external_guard(_value.l));
 809         locals->set_obj_at (_index, ob_h);
 810         break;
 811       }
 812       default: ShouldNotReachHere();
 813     }
 814     _jvf->set_locals(locals);
 815   } else {
 816     if (_jvf->method()->is_native() && _jvf->is_compiled_frame()) {
 817       assert(getting_receiver(), "Can only get here when getting receiver");
 818       oop receiver = _jvf->fr().get_native_receiver();
 819       _value.l = JNIHandles::make_local(_calling_thread, receiver);
 820     } else {
 821       StackValueCollection *locals = _jvf->locals();
 822 
 823       switch (_type) {
 824         case T_INT:    _value.i = locals->int_at   (_index);   break;
 825         case T_LONG:   _value.j = locals->long_at  (_index);   break;
 826         case T_FLOAT:  _value.f = locals->float_at (_index);   break;
 827         case T_DOUBLE: _value.d = locals->double_at(_index);   break;
 828         case T_OBJECT: {
 829           // Wrap the oop to be returned in a local JNI handle since
 830           // oops_do() no longer applies after doit() is finished.
 831           oop obj = locals->obj_at(_index)();
 832           _value.l = JNIHandles::make_local(_calling_thread, obj);
 833           break;
 834         }
 835         default: ShouldNotReachHere();
 836       }
 837     }
 838   }
 839 }
 840 
 841 
 842 bool VM_GetOrSetLocal::allow_nested_vm_operations() const {
 843   return true; // May need to deoptimize
 844 }
 845 
 846 
 847 VM_GetReceiver::VM_GetReceiver(
 848     JavaThread* thread, JavaThread* caller_thread, jint depth)
 849     : VM_GetOrSetLocal(thread, caller_thread, depth, 0) {}
 850 
 851 /////////////////////////////////////////////////////////////////////////////////////////
 852 
 853 //
 854 // class JvmtiSuspendControl - see comments in jvmtiImpl.hpp
 855 //
 856 
 857 bool JvmtiSuspendControl::suspend(JavaThread *java_thread) {
 858   // external suspend should have caught suspending a thread twice
 859 
 860   // Immediate suspension required for JPDA back-end so JVMTI agent threads do
 861   // not deadlock due to later suspension on transitions while holding
 862   // raw monitors.  Passing true causes the immediate suspension.
 863   // java_suspend() will catch threads in the process of exiting
 864   // and will ignore them.
 865   java_thread->java_suspend();
 866 
 867   // It would be nice to have the following assertion in all the time,
 868   // but it is possible for a racing resume request to have resumed
 869   // this thread right after we suspended it. Temporarily enable this
 870   // assertion if you are chasing a different kind of bug.
 871   //
 872   // assert(java_lang_Thread::thread(java_thread->threadObj()) == NULL ||
 873   //   java_thread->is_being_ext_suspended(), "thread is not suspended");
 874 
 875   if (java_lang_Thread::thread(java_thread->threadObj()) == NULL) {
 876     // check again because we can get delayed in java_suspend():
 877     // the thread is in process of exiting.
 878     return false;
 879   }
 880 
 881   return true;
 882 }
 883 
 884 bool JvmtiSuspendControl::resume(JavaThread *java_thread) {
 885   // external suspend should have caught resuming a thread twice
 886   assert(java_thread->is_being_ext_suspended(), "thread should be suspended");
 887 
 888   // resume thread
 889   {
 890     // must always grab Threads_lock, see JVM_SuspendThread
 891     MutexLocker ml(Threads_lock);
 892     java_thread->java_resume();
 893   }
 894 
 895   return true;
 896 }
 897 
 898 
 899 void JvmtiSuspendControl::print() {
 900 #ifndef PRODUCT
 901   LogStreamHandle(Trace, jvmti) log_stream;
 902   log_stream.print("Suspended Threads: [");
 903   for (JavaThreadIteratorWithHandle jtiwh; JavaThread *thread = jtiwh.next(); ) {
 904 #ifdef JVMTI_TRACE
 905     const char *name   = JvmtiTrace::safe_get_thread_name(thread);
 906 #else
 907     const char *name   = "";
 908 #endif /*JVMTI_TRACE */
 909     log_stream.print("%s(%c ", name, thread->is_being_ext_suspended() ? 'S' : '_');
 910     if (!thread->has_last_Java_frame()) {
 911       log_stream.print("no stack");
 912     }
 913     log_stream.print(") ");
 914   }
 915   log_stream.print_cr("]");
 916 #endif
 917 }
 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 bool JvmtiDeferredEventQueue::has_events() {
 999   assert(Service_lock->owned_by_self(), "Must own Service_lock");
1000   return _queue_head != NULL;
1001 }
1002 
1003 void JvmtiDeferredEventQueue::enqueue(const JvmtiDeferredEvent& event) {
1004   assert(Service_lock->owned_by_self(), "Must own Service_lock");
1005 
1006   // Events get added to the end of the queue (and are pulled off the front).
1007   QueueNode* node = new QueueNode(event);
1008   if (_queue_tail == NULL) {
1009     _queue_tail = _queue_head = node;
1010   } else {
1011     assert(_queue_tail->next() == NULL, "Must be the last element in the list");
1012     _queue_tail->set_next(node);
1013     _queue_tail = node;
1014   }
1015 
1016   Service_lock->notify_all();
1017   assert((_queue_head == NULL) == (_queue_tail == NULL),
1018          "Inconsistent queue markers");
1019 }
1020 
1021 JvmtiDeferredEvent JvmtiDeferredEventQueue::dequeue() {
1022   assert(Service_lock->owned_by_self(), "Must own Service_lock");
1023 
1024   assert(_queue_head != NULL, "Nothing to dequeue");
1025 
1026   if (_queue_head == NULL) {
1027     // Just in case this happens in product; it shouldn't but let's not crash
1028     return JvmtiDeferredEvent();
1029   }
1030 
1031   QueueNode* node = _queue_head;
1032   _queue_head = _queue_head->next();
1033   if (_queue_head == NULL) {
1034     _queue_tail = NULL;
1035   }
1036 
1037   assert((_queue_head == NULL) == (_queue_tail == NULL),
1038          "Inconsistent queue markers");
1039 
1040   JvmtiDeferredEvent event = node->event();
1041   delete node;
1042   return event;
1043 }