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(&reg_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