1 /*
   2  * Copyright (c) 2003, 2024, 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/javaClasses.inline.hpp"
  27 #include "classfile/moduleEntry.hpp"
  28 #include "classfile/vmClasses.hpp"
  29 #include "classfile/vmSymbols.hpp"
  30 #include "code/nmethod.hpp"
  31 #include "code/pcDesc.hpp"
  32 #include "code/scopeDesc.hpp"
  33 #include "gc/shared/oopStorageSet.hpp"
  34 #include "interpreter/interpreter.hpp"
  35 #include "jvmtifiles/jvmtiEnv.hpp"
  36 #include "logging/log.hpp"
  37 #include "logging/logStream.hpp"
  38 #include "memory/allocation.inline.hpp"
  39 #include "memory/resourceArea.hpp"
  40 #include "memory/universe.hpp"
  41 #include "oops/klass.inline.hpp"
  42 #include "oops/objArrayKlass.hpp"
  43 #include "oops/objArrayOop.hpp"
  44 #include "oops/oop.inline.hpp"
  45 #include "oops/oopHandle.inline.hpp"
  46 #include "prims/jvmtiAgentList.hpp"
  47 #include "prims/jvmtiCodeBlobEvents.hpp"
  48 #include "prims/jvmtiEventController.hpp"
  49 #include "prims/jvmtiEventController.inline.hpp"
  50 #include "prims/jvmtiExport.hpp"
  51 #include "prims/jvmtiImpl.hpp"
  52 #include "prims/jvmtiManageCapabilities.hpp"
  53 #include "prims/jvmtiRawMonitor.hpp"
  54 #include "prims/jvmtiRedefineClasses.hpp"
  55 #include "prims/jvmtiTagMap.hpp"
  56 #include "prims/jvmtiThreadState.inline.hpp"
  57 #include "runtime/arguments.hpp"
  58 #include "runtime/fieldDescriptor.inline.hpp"
  59 #include "runtime/handles.inline.hpp"
  60 #include "runtime/interfaceSupport.inline.hpp"
  61 #include "runtime/javaCalls.hpp"
  62 #include "runtime/javaThread.hpp"
  63 #include "runtime/jniHandles.inline.hpp"
  64 #include "runtime/keepStackGCProcessed.hpp"
  65 #include "runtime/objectMonitor.hpp"
  66 #include "runtime/objectMonitor.inline.hpp"
  67 #include "runtime/os.hpp"
  68 #include "runtime/osThread.hpp"
  69 #include "runtime/safepointVerifiers.hpp"
  70 #include "runtime/serviceThread.hpp"
  71 #include "runtime/threads.hpp"
  72 #include "runtime/threadSMR.hpp"
  73 #include "runtime/vframe.inline.hpp"
  74 #include "runtime/vm_version.hpp"
  75 #include "utilities/macros.hpp"
  76 
  77 #ifdef JVMTI_TRACE
  78 #define EVT_TRACE(evt,out) if ((JvmtiTrace::event_trace_flags(evt) & JvmtiTrace::SHOW_EVENT_SENT) != 0) { SafeResourceMark rm; log_trace(jvmti) out; }
  79 #define EVT_TRIG_TRACE(evt,out) if ((JvmtiTrace::event_trace_flags(evt) & JvmtiTrace::SHOW_EVENT_TRIGGER) != 0) { SafeResourceMark rm; log_trace(jvmti) out; }
  80 #else
  81 #define EVT_TRIG_TRACE(evt,out)
  82 #define EVT_TRACE(evt,out)
  83 #endif
  84 
  85 ///////////////////////////////////////////////////////////////
  86 //
  87 // JvmtiEventTransition
  88 //
  89 // TO DO --
  90 //  more handle purging
  91 
  92 // Use this for JavaThreads and state is  _thread_in_vm.
  93 class JvmtiJavaThreadEventTransition : StackObj {
  94 private:
  95   ResourceMark _rm;
  96   ThreadToNativeFromVM _transition;
  97   HandleMark _hm;
  98 
  99 public:
 100   JvmtiJavaThreadEventTransition(JavaThread *thread) :
 101     _rm(),
 102     _transition(thread),
 103     _hm(thread)  {};
 104 };
 105 
 106 // For JavaThreads which are not in _thread_in_vm state
 107 // and other system threads use this.
 108 class JvmtiThreadEventTransition : StackObj {
 109 private:
 110   ResourceMark _rm;
 111   HandleMark _hm;
 112   JavaThreadState _saved_state;
 113   JavaThread *_jthread;
 114 
 115 public:
 116   JvmtiThreadEventTransition(Thread *thread) : _rm(), _hm(thread) {
 117     if (thread->is_Java_thread()) {
 118        _jthread = JavaThread::cast(thread);
 119        _saved_state = _jthread->thread_state();
 120        if (_saved_state == _thread_in_Java) {
 121          ThreadStateTransition::transition_from_java(_jthread, _thread_in_native);
 122        } else {
 123          ThreadStateTransition::transition_from_vm(_jthread, _thread_in_native);
 124        }
 125     } else {
 126       _jthread = nullptr;
 127     }
 128   }
 129 
 130   ~JvmtiThreadEventTransition() {
 131     if (_jthread != nullptr)
 132       ThreadStateTransition::transition_from_native(_jthread, _saved_state);
 133   }
 134 };
 135 
 136 
 137 ///////////////////////////////////////////////////////////////
 138 //
 139 // JvmtiEventMark
 140 //
 141 
 142 class JvmtiEventMark : public StackObj {
 143 private:
 144   JavaThread *_thread;
 145   JNIEnv* _jni_env;
 146   JvmtiThreadState::ExceptionState _saved_exception_state;
 147 
 148 public:
 149   JvmtiEventMark(JavaThread *thread) :  _thread(thread),
 150                                         _jni_env(thread->jni_environment()),
 151                                         _saved_exception_state(JvmtiThreadState::ES_CLEARED) {
 152     JvmtiThreadState *state = thread->jvmti_thread_state();
 153     // we are before an event.
 154     // Save current jvmti thread exception state.
 155     if (state != nullptr) {
 156       _saved_exception_state = state->get_exception_state();
 157     }
 158 
 159     thread->push_jni_handle_block();
 160     assert(thread == JavaThread::current(), "thread must be current!");
 161     thread->frame_anchor()->make_walkable();
 162   };
 163 
 164   ~JvmtiEventMark() {
 165     _thread->pop_jni_handle_block();
 166 
 167     JvmtiThreadState* state = _thread->jvmti_thread_state();
 168     // we are continuing after an event.
 169     if (state != nullptr) {
 170       // Restore the jvmti thread exception state.
 171       state->restore_exception_state(_saved_exception_state);
 172     }
 173   }
 174 
 175   jobject to_jobject(oop obj) { return JNIHandles::make_local(_thread,obj); }
 176 
 177   jclass to_jclass(Klass* klass) { return (klass == nullptr ? nullptr : (jclass)to_jobject(klass->java_mirror())); }
 178 
 179   jmethodID to_jmethodID(const methodHandle& method) { return method->jmethod_id(); }
 180 
 181   JNIEnv* jni_env() { return _jni_env; }
 182 };
 183 
 184 class JvmtiThreadEventMark : public JvmtiEventMark {
 185 private:
 186   jobject _jthread;
 187 
 188 public:
 189   JvmtiThreadEventMark(JavaThread *thread) :
 190     JvmtiEventMark(thread) {
 191     _jthread = to_jobject(thread->threadObj());
 192   };
 193  jthread jni_thread() { return (jthread)_jthread; }
 194 };
 195 
 196 class JvmtiVirtualThreadEventMark : public JvmtiEventMark {
 197 private:
 198   jobject _jthread;
 199 
 200 public:
 201   JvmtiVirtualThreadEventMark(JavaThread *thread) :
 202     JvmtiEventMark(thread) {
 203     assert(thread->vthread() != nullptr || thread->threadObj() == nullptr, "sanity check");
 204     _jthread = to_jobject(thread->vthread());
 205   };
 206   jthread jni_thread() { return (jthread)_jthread; }
 207 };
 208 
 209 class JvmtiClassEventMark : public JvmtiVirtualThreadEventMark {
 210 private:
 211   jclass _jc;
 212 
 213 public:
 214   JvmtiClassEventMark(JavaThread *thread, Klass* klass) :
 215     JvmtiVirtualThreadEventMark(thread) {
 216     _jc = to_jclass(klass);
 217   };
 218   jclass jni_class() { return _jc; }
 219 };
 220 
 221 class JvmtiMethodEventMark : public JvmtiVirtualThreadEventMark {
 222 private:
 223   jmethodID _mid;
 224 
 225 public:
 226   JvmtiMethodEventMark(JavaThread *thread, const methodHandle& method) :
 227     JvmtiVirtualThreadEventMark(thread),
 228     _mid(to_jmethodID(method)) {};
 229   jmethodID jni_methodID() { return _mid; }
 230 };
 231 
 232 class JvmtiLocationEventMark : public JvmtiMethodEventMark {
 233 private:
 234   jlocation _loc;
 235 
 236 public:
 237   JvmtiLocationEventMark(JavaThread *thread, const methodHandle& method, address location) :
 238     JvmtiMethodEventMark(thread, method),
 239     _loc(location - method->code_base()) {};
 240   jlocation location() { return _loc; }
 241 };
 242 
 243 class JvmtiExceptionEventMark : public JvmtiLocationEventMark {
 244 private:
 245   jobject _exc;
 246 
 247 public:
 248   JvmtiExceptionEventMark(JavaThread *thread, const methodHandle& method, address location, Handle exception) :
 249     JvmtiLocationEventMark(thread, method, location),
 250     _exc(to_jobject(exception())) {};
 251   jobject exception() { return _exc; }
 252 };
 253 
 254 class JvmtiClassFileLoadEventMark : public JvmtiThreadEventMark {
 255 private:
 256   const char *_class_name;
 257   jobject _jloader;
 258   jobject _protection_domain;
 259   jclass  _class_being_redefined;
 260 
 261 public:
 262   JvmtiClassFileLoadEventMark(JavaThread *thread, Symbol* name,
 263      Handle class_loader, Handle prot_domain, Klass* class_being_redefined) : JvmtiThreadEventMark(thread) {
 264       _class_name = name != nullptr? name->as_utf8() : nullptr;
 265       _jloader = (jobject)to_jobject(class_loader());
 266       _protection_domain = (jobject)to_jobject(prot_domain());
 267       if (class_being_redefined == nullptr) {
 268         _class_being_redefined = nullptr;
 269       } else {
 270         _class_being_redefined = (jclass)to_jclass(class_being_redefined);
 271       }
 272   };
 273   const char *class_name() {
 274     return _class_name;
 275   }
 276   jobject jloader() {
 277     return _jloader;
 278   }
 279   jobject protection_domain() {
 280     return _protection_domain;
 281   }
 282   jclass class_being_redefined() {
 283     return _class_being_redefined;
 284   }
 285 };
 286 
 287 //////////////////////////////////////////////////////////////////////////////
 288 
 289 int               JvmtiExport::_field_access_count                        = 0;
 290 int               JvmtiExport::_field_modification_count                  = 0;
 291 
 292 bool              JvmtiExport::_can_access_local_variables                = false;
 293 bool              JvmtiExport::_can_hotswap_or_post_breakpoint            = false;
 294 bool              JvmtiExport::_can_modify_any_class                      = false;
 295 bool              JvmtiExport::_can_walk_any_space                        = false;
 296 
 297 uint64_t          JvmtiExport::_redefinition_count                        = 0;
 298 bool              JvmtiExport::_all_dependencies_are_recorded             = false;
 299 
 300 //
 301 // field access management
 302 //
 303 
 304 // interpreter generator needs the address of the counter
 305 address JvmtiExport::get_field_access_count_addr() {
 306   // We don't grab a lock because we don't want to
 307   // serialize field access between all threads. This means that a
 308   // thread on another processor can see the wrong count value and
 309   // may either miss making a needed call into post_field_access()
 310   // or will make an unneeded call into post_field_access(). We pay
 311   // this price to avoid slowing down the VM when we aren't watching
 312   // field accesses.
 313   // Other access/mutation safe by virtue of being in VM state.
 314   return (address)(&_field_access_count);
 315 }
 316 
 317 //
 318 // field modification management
 319 //
 320 
 321 // interpreter generator needs the address of the counter
 322 address JvmtiExport::get_field_modification_count_addr() {
 323   // We don't grab a lock because we don't
 324   // want to serialize field modification between all threads. This
 325   // means that a thread on another processor can see the wrong
 326   // count value and may either miss making a needed call into
 327   // post_field_modification() or will make an unneeded call into
 328   // post_field_modification(). We pay this price to avoid slowing
 329   // down the VM when we aren't watching field modifications.
 330   // Other access/mutation safe by virtue of being in VM state.
 331   return (address)(&_field_modification_count);
 332 }
 333 
 334 
 335 ///////////////////////////////////////////////////////////////
 336 // Functions needed by java.lang.instrument for starting up javaagent.
 337 ///////////////////////////////////////////////////////////////
 338 
 339 jint
 340 JvmtiExport::get_jvmti_interface(JavaVM *jvm, void **penv, jint version) {
 341   // The JVMTI_VERSION_INTERFACE_JVMTI part of the version number
 342   // has already been validated in JNI GetEnv().
 343   int major, minor, micro;
 344 
 345   // micro version doesn't matter here (yet?)
 346   decode_version_values(version, &major, &minor, &micro);
 347   switch (major) {
 348     case 1:
 349       switch (minor) {
 350         case 0:  // version 1.0.<micro> is recognized
 351         case 1:  // version 1.1.<micro> is recognized
 352         case 2:  // version 1.2.<micro> is recognized
 353           break;
 354 
 355         default:
 356           return JNI_EVERSION;  // unsupported minor version number
 357       }
 358       break;
 359     case 9:
 360       switch (minor) {
 361         case 0:  // version 9.0.<micro> is recognized
 362           break;
 363         default:
 364           return JNI_EVERSION;  // unsupported minor version number
 365       }
 366       break;
 367     case 11:
 368       switch (minor) {
 369         case 0:  // version 11.0.<micro> is recognized
 370           break;
 371         default:
 372           return JNI_EVERSION;  // unsupported minor version number
 373       }
 374       break;
 375     default:
 376       // Starting from 13 we do not care about minor version anymore
 377       if (major < 13 || major > VM_Version::vm_major_version()) {
 378         return JNI_EVERSION;  // unsupported major version number
 379       }
 380   }
 381 
 382   if (JvmtiEnv::get_phase() == JVMTI_PHASE_LIVE) {
 383     JavaThread* current_thread = JavaThread::current();
 384     // transition code: native to VM
 385     MACOS_AARCH64_ONLY(ThreadWXEnable __wx(WXWrite, current_thread));
 386     ThreadInVMfromNative __tiv(current_thread);
 387     VM_ENTRY_BASE(jvmtiEnv*, JvmtiExport::get_jvmti_interface, current_thread)
 388     debug_only(VMNativeEntryWrapper __vew;)
 389 
 390     JvmtiEnv *jvmti_env = JvmtiEnv::create_a_jvmti(version);
 391     *penv = jvmti_env->jvmti_external();  // actual type is jvmtiEnv* -- not to be confused with JvmtiEnv*
 392 
 393     if (Continuations::enabled()) {
 394       // Virtual threads support for agents loaded into running VM.
 395       // There is a performance impact when VTMS transitions are enabled.
 396       if (!JvmtiVTMSTransitionDisabler::VTMS_notify_jvmti_events()) {
 397         JvmtiEnvBase::enable_virtual_threads_notify_jvmti();
 398       }
 399     }
 400     return JNI_OK;
 401 
 402   } else if (JvmtiEnv::get_phase() == JVMTI_PHASE_ONLOAD) {
 403     // not live, no thread to transition
 404     JvmtiEnv *jvmti_env = JvmtiEnv::create_a_jvmti(version);
 405     *penv = jvmti_env->jvmti_external();  // actual type is jvmtiEnv* -- not to be confused with JvmtiEnv*
 406 
 407     if (Continuations::enabled()) {
 408       // Virtual threads support for agents loaded at startup.
 409       // There is a performance impact when VTMS transitions are enabled.
 410       JvmtiVTMSTransitionDisabler::set_VTMS_notify_jvmti_events(true);
 411     }
 412     return JNI_OK;
 413 
 414   } else {
 415     // Called at the wrong time
 416     *penv = nullptr;
 417     return JNI_EDETACHED;
 418   }
 419 }
 420 
 421 JvmtiThreadState*
 422 JvmtiExport::get_jvmti_thread_state(JavaThread *thread) {
 423   assert(thread == JavaThread::current(), "must be current thread");
 424   if (thread->is_vthread_mounted() && thread->jvmti_thread_state() == nullptr) {
 425     JvmtiEventController::thread_started(thread);
 426   }
 427   return thread->jvmti_thread_state();
 428 }
 429 
 430 void
 431 JvmtiExport::add_default_read_edges(Handle h_module, TRAPS) {
 432   if (!Universe::is_module_initialized()) {
 433     return; // extra safety
 434   }
 435   assert(!h_module.is_null(), "module should always be set");
 436 
 437   // Invoke the transformedByAgent method
 438   JavaValue result(T_VOID);
 439   JavaCalls::call_static(&result,
 440                          vmClasses::module_Modules_klass(),
 441                          vmSymbols::transformedByAgent_name(),
 442                          vmSymbols::transformedByAgent_signature(),
 443                          h_module,
 444                          THREAD);
 445 
 446   if (HAS_PENDING_EXCEPTION) {
 447     LogTarget(Trace, jvmti) log;
 448     LogStream log_stream(log);
 449     java_lang_Throwable::print(PENDING_EXCEPTION, &log_stream);
 450     log_stream.cr();
 451     CLEAR_PENDING_EXCEPTION;
 452     return;
 453   }
 454 }
 455 
 456 jvmtiError
 457 JvmtiExport::add_module_reads(Handle module, Handle to_module, TRAPS) {
 458   if (!Universe::is_module_initialized()) {
 459     return JVMTI_ERROR_NONE; // extra safety
 460   }
 461   assert(!module.is_null(), "module should always be set");
 462   assert(!to_module.is_null(), "to_module should always be set");
 463 
 464   // Invoke the addReads method
 465   JavaValue result(T_VOID);
 466   JavaCalls::call_static(&result,
 467                          vmClasses::module_Modules_klass(),
 468                          vmSymbols::addReads_name(),
 469                          vmSymbols::addReads_signature(),
 470                          module,
 471                          to_module,
 472                          THREAD);
 473 
 474   if (HAS_PENDING_EXCEPTION) {
 475     LogTarget(Trace, jvmti) log;
 476     LogStream log_stream(log);
 477     java_lang_Throwable::print(PENDING_EXCEPTION, &log_stream);
 478     log_stream.cr();
 479     CLEAR_PENDING_EXCEPTION;
 480     return JVMTI_ERROR_INTERNAL;
 481   }
 482   return JVMTI_ERROR_NONE;
 483 }
 484 
 485 jvmtiError
 486 JvmtiExport::add_module_exports(Handle module, Handle pkg_name, Handle to_module, TRAPS) {
 487   if (!Universe::is_module_initialized()) {
 488     return JVMTI_ERROR_NONE; // extra safety
 489   }
 490   assert(!module.is_null(), "module should always be set");
 491   assert(!to_module.is_null(), "to_module should always be set");
 492   assert(!pkg_name.is_null(), "pkg_name should always be set");
 493 
 494   // Invoke the addExports method
 495   JavaValue result(T_VOID);
 496   JavaCalls::call_static(&result,
 497                          vmClasses::module_Modules_klass(),
 498                          vmSymbols::addExports_name(),
 499                          vmSymbols::addExports_signature(),
 500                          module,
 501                          pkg_name,
 502                          to_module,
 503                          THREAD);
 504 
 505   if (HAS_PENDING_EXCEPTION) {
 506     Symbol* ex_name = PENDING_EXCEPTION->klass()->name();
 507     LogTarget(Trace, jvmti) log;
 508     LogStream log_stream(log);
 509     java_lang_Throwable::print(PENDING_EXCEPTION, &log_stream);
 510     log_stream.cr();
 511     CLEAR_PENDING_EXCEPTION;
 512     if (ex_name == vmSymbols::java_lang_IllegalArgumentException()) {
 513       return JVMTI_ERROR_ILLEGAL_ARGUMENT;
 514     }
 515     return JVMTI_ERROR_INTERNAL;
 516   }
 517   return JVMTI_ERROR_NONE;
 518 }
 519 
 520 jvmtiError
 521 JvmtiExport::add_module_opens(Handle module, Handle pkg_name, Handle to_module, TRAPS) {
 522   if (!Universe::is_module_initialized()) {
 523     return JVMTI_ERROR_NONE; // extra safety
 524   }
 525   assert(!module.is_null(), "module should always be set");
 526   assert(!to_module.is_null(), "to_module should always be set");
 527   assert(!pkg_name.is_null(), "pkg_name should always be set");
 528 
 529   // Invoke the addOpens method
 530   JavaValue result(T_VOID);
 531   JavaCalls::call_static(&result,
 532                          vmClasses::module_Modules_klass(),
 533                          vmSymbols::addOpens_name(),
 534                          vmSymbols::addExports_signature(),
 535                          module,
 536                          pkg_name,
 537                          to_module,
 538                          THREAD);
 539 
 540   if (HAS_PENDING_EXCEPTION) {
 541     Symbol* ex_name = PENDING_EXCEPTION->klass()->name();
 542     LogTarget(Trace, jvmti) log;
 543     LogStream log_stream(log);
 544     java_lang_Throwable::print(PENDING_EXCEPTION, &log_stream);
 545     log_stream.cr();
 546     CLEAR_PENDING_EXCEPTION;
 547     if (ex_name == vmSymbols::java_lang_IllegalArgumentException()) {
 548       return JVMTI_ERROR_ILLEGAL_ARGUMENT;
 549     }
 550     return JVMTI_ERROR_INTERNAL;
 551   }
 552   return JVMTI_ERROR_NONE;
 553 }
 554 
 555 jvmtiError
 556 JvmtiExport::add_module_uses(Handle module, Handle service, TRAPS) {
 557   if (!Universe::is_module_initialized()) {
 558     return JVMTI_ERROR_NONE; // extra safety
 559   }
 560   assert(!module.is_null(), "module should always be set");
 561   assert(!service.is_null(), "service should always be set");
 562 
 563   // Invoke the addUses method
 564   JavaValue result(T_VOID);
 565   JavaCalls::call_static(&result,
 566                          vmClasses::module_Modules_klass(),
 567                          vmSymbols::addUses_name(),
 568                          vmSymbols::addUses_signature(),
 569                          module,
 570                          service,
 571                          THREAD);
 572 
 573   if (HAS_PENDING_EXCEPTION) {
 574     LogTarget(Trace, jvmti) log;
 575     LogStream log_stream(log);
 576     java_lang_Throwable::print(PENDING_EXCEPTION, &log_stream);
 577     log_stream.cr();
 578     CLEAR_PENDING_EXCEPTION;
 579     return JVMTI_ERROR_INTERNAL;
 580   }
 581   return JVMTI_ERROR_NONE;
 582 }
 583 
 584 jvmtiError
 585 JvmtiExport::add_module_provides(Handle module, Handle service, Handle impl_class, TRAPS) {
 586   if (!Universe::is_module_initialized()) {
 587     return JVMTI_ERROR_NONE; // extra safety
 588   }
 589   assert(!module.is_null(), "module should always be set");
 590   assert(!service.is_null(), "service should always be set");
 591   assert(!impl_class.is_null(), "impl_class should always be set");
 592 
 593   // Invoke the addProvides method
 594   JavaValue result(T_VOID);
 595   JavaCalls::call_static(&result,
 596                          vmClasses::module_Modules_klass(),
 597                          vmSymbols::addProvides_name(),
 598                          vmSymbols::addProvides_signature(),
 599                          module,
 600                          service,
 601                          impl_class,
 602                          THREAD);
 603 
 604   if (HAS_PENDING_EXCEPTION) {
 605     LogTarget(Trace, jvmti) log;
 606     LogStream log_stream(log);
 607     java_lang_Throwable::print(PENDING_EXCEPTION, &log_stream);
 608     log_stream.cr();
 609     CLEAR_PENDING_EXCEPTION;
 610     return JVMTI_ERROR_INTERNAL;
 611   }
 612   return JVMTI_ERROR_NONE;
 613 }
 614 
 615 void
 616 JvmtiExport::decode_version_values(jint version, int * major, int * minor,
 617                                    int * micro) {
 618   *major = (version & JVMTI_VERSION_MASK_MAJOR) >> JVMTI_VERSION_SHIFT_MAJOR;
 619   *minor = (version & JVMTI_VERSION_MASK_MINOR) >> JVMTI_VERSION_SHIFT_MINOR;
 620   *micro = (version & JVMTI_VERSION_MASK_MICRO) >> JVMTI_VERSION_SHIFT_MICRO;
 621 }
 622 
 623 void JvmtiExport::enter_primordial_phase() {
 624   JvmtiEnvBase::set_phase(JVMTI_PHASE_PRIMORDIAL);
 625 }
 626 
 627 void JvmtiExport::enter_early_start_phase() {
 628   set_early_vmstart_recorded(true);
 629 }
 630 
 631 void JvmtiExport::enter_start_phase() {
 632   JvmtiEnvBase::set_phase(JVMTI_PHASE_START);
 633 }
 634 
 635 void JvmtiExport::enter_onload_phase() {
 636   JvmtiEnvBase::set_phase(JVMTI_PHASE_ONLOAD);
 637 }
 638 
 639 void JvmtiExport::enter_live_phase() {
 640   JvmtiEnvBase::set_phase(JVMTI_PHASE_LIVE);
 641 }
 642 
 643 //
 644 // JVMTI events that the VM posts to the debugger and also startup agent
 645 // and call the agent's premain() for java.lang.instrument.
 646 //
 647 
 648 void JvmtiExport::post_early_vm_start() {
 649   EVT_TRIG_TRACE(JVMTI_EVENT_VM_START, ("Trg Early VM start event triggered" ));
 650 
 651   // can now enable some events
 652   JvmtiEventController::vm_start();
 653 
 654   JvmtiEnvIterator it;
 655   for (JvmtiEnv* env = it.first(); env != nullptr; env = it.next(env)) {
 656     // Only early vmstart envs post early VMStart event
 657     if (env->early_vmstart_env() && env->is_enabled(JVMTI_EVENT_VM_START)) {
 658       EVT_TRACE(JVMTI_EVENT_VM_START, ("Evt Early VM start event sent" ));
 659       JavaThread *thread  = JavaThread::current();
 660       JvmtiThreadEventMark jem(thread);
 661       JvmtiJavaThreadEventTransition jet(thread);
 662       jvmtiEventVMStart callback = env->callbacks()->VMStart;
 663       if (callback != nullptr) {
 664         (*callback)(env->jvmti_external(), jem.jni_env());
 665       }
 666     }
 667   }
 668 }
 669 
 670 void JvmtiExport::post_vm_start() {
 671   EVT_TRIG_TRACE(JVMTI_EVENT_VM_START, ("Trg VM start event triggered" ));
 672 
 673   // can now enable some events
 674   JvmtiEventController::vm_start();
 675 
 676   JvmtiEnvIterator it;
 677   for (JvmtiEnv* env = it.first(); env != nullptr; env = it.next(env)) {
 678     // Early vmstart envs do not post normal VMStart event
 679     if (!env->early_vmstart_env() && env->is_enabled(JVMTI_EVENT_VM_START)) {
 680       EVT_TRACE(JVMTI_EVENT_VM_START, ("Evt VM start event sent" ));
 681 
 682       JavaThread *thread  = JavaThread::current();
 683       JvmtiThreadEventMark jem(thread);
 684       JvmtiJavaThreadEventTransition jet(thread);
 685       jvmtiEventVMStart callback = env->callbacks()->VMStart;
 686       if (callback != nullptr) {
 687         (*callback)(env->jvmti_external(), jem.jni_env());
 688       }
 689     }
 690   }
 691 }
 692 
 693 static OopStorage* _jvmti_oop_storage = nullptr;
 694 static OopStorage* _weak_tag_storage = nullptr;
 695 
 696 OopStorage* JvmtiExport::jvmti_oop_storage() {
 697   assert(_jvmti_oop_storage != nullptr, "not yet initialized");
 698   return _jvmti_oop_storage;
 699 }
 700 
 701 OopStorage* JvmtiExport::weak_tag_storage() {
 702   assert(_weak_tag_storage != nullptr, "not yet initialized");
 703   return _weak_tag_storage;
 704 }
 705 
 706 void JvmtiExport::initialize_oop_storage() {
 707   // OopStorage needs to be created early in startup and unconditionally
 708   // because of OopStorageSet static array indices.
 709   _jvmti_oop_storage = OopStorageSet::create_strong("JVMTI OopStorage", mtServiceability);
 710   _weak_tag_storage  = OopStorageSet::create_weak("JVMTI Tag Weak OopStorage", mtServiceability);
 711   _weak_tag_storage->register_num_dead_callback(&JvmtiTagMap::gc_notification);
 712 }
 713 
 714 // Lookup an agent from an JvmtiEnv. Return agent only if it is not yet initialized.
 715 // An agent can create multiple JvmtiEnvs, but for agent initialization, we are only interested in the initial one.
 716 static JvmtiAgent* lookup_uninitialized_agent(JvmtiEnv* env, void* callback) {
 717   JvmtiAgent* const agent = JvmtiAgentList::lookup(env, callback);
 718   return agent == nullptr || agent->is_initialized() ? nullptr : agent;
 719 }
 720 
 721 void JvmtiExport::post_vm_initialized() {
 722   EVT_TRIG_TRACE(JVMTI_EVENT_VM_INIT, ("Trg VM init event triggered" ));
 723 
 724   // can now enable events
 725   JvmtiEventController::vm_init();
 726 
 727   JvmtiEnvIterator it;
 728   for (JvmtiEnv* env = it.first(); env != nullptr; env = it.next(env)) {
 729     if (env->is_enabled(JVMTI_EVENT_VM_INIT)) {
 730       EVT_TRACE(JVMTI_EVENT_VM_INIT, ("Evt VM init event sent" ));
 731 
 732       JavaThread *thread  = JavaThread::current();
 733       JvmtiThreadEventMark jem(thread);
 734       JvmtiJavaThreadEventTransition jet(thread);
 735       jvmtiEventVMInit callback = env->callbacks()->VMInit;
 736       if (callback != nullptr) {
 737         // We map the JvmtiEnv to its Agent to measure when and for how long
 738         // it took to initialize so that JFR can report this information.
 739         JvmtiAgent* const agent = lookup_uninitialized_agent(env, reinterpret_cast<void*>(callback));
 740         if (agent != nullptr) {
 741           agent->initialization_begin();
 742         }
 743         (*callback)(env->jvmti_external(), jem.jni_env(), jem.jni_thread());
 744         if (agent != nullptr) {
 745           agent->initialization_end();
 746         }
 747       }
 748     }
 749   }
 750 
 751   // Agents are initialized as part of posting the VMInit event above.
 752   // For -Xrun agents and agents with no VMInit callback, we explicitly ensure they are also initialized.
 753   // JVM_OnLoad and Agent_OnLoad callouts are performed too early for the proper timestamp logic.
 754   JvmtiAgentList::initialize();
 755 }
 756 
 757 void JvmtiExport::post_vm_death() {
 758   EVT_TRIG_TRACE(JVMTI_EVENT_VM_DEATH, ("Trg VM death event triggered" ));
 759 
 760   JvmtiTagMap::flush_all_object_free_events();
 761 
 762   JvmtiEnvIterator it;
 763   for (JvmtiEnv* env = it.first(); env != nullptr; env = it.next(env)) {
 764     if (env->is_enabled(JVMTI_EVENT_VM_DEATH)) {
 765       EVT_TRACE(JVMTI_EVENT_VM_DEATH, ("Evt VM death event sent" ));
 766 
 767       JavaThread *thread  = JavaThread::current();
 768       JvmtiEventMark jem(thread);
 769       JvmtiJavaThreadEventTransition jet(thread);
 770       jvmtiEventVMDeath callback = env->callbacks()->VMDeath;
 771       if (callback != nullptr) {
 772         (*callback)(env->jvmti_external(), jem.jni_env());
 773       }
 774     }
 775   }
 776 
 777   JvmtiEnvBase::set_phase(JVMTI_PHASE_DEAD);
 778   JvmtiEventController::vm_death();
 779 }
 780 
 781 char**
 782 JvmtiExport::get_all_native_method_prefixes(int* count_ptr) {
 783   // Have to grab JVMTI thread state lock to be sure environment doesn't
 784   // go away while we iterate them.  No locks during VM bring-up.
 785   if (Threads::number_of_threads() == 0 || SafepointSynchronize::is_at_safepoint()) {
 786     return JvmtiEnvBase::get_all_native_method_prefixes(count_ptr);
 787   } else {
 788     MutexLocker mu(JvmtiThreadState_lock);
 789     return JvmtiEnvBase::get_all_native_method_prefixes(count_ptr);
 790   }
 791 }
 792 
 793 // Convert an external thread reference to a JavaThread found on the
 794 // specified ThreadsList. The ThreadsListHandle in the caller "protects"
 795 // the returned JavaThread *.
 796 //
 797 // If thread_oop_p is not null, then the caller wants to use the oop
 798 // after this call so the oop is returned. On success, *jt_pp is set
 799 // to the converted JavaThread * and JVMTI_ERROR_NONE is returned.
 800 // On error, returns various JVMTI_ERROR_* values.
 801 //
 802 jvmtiError
 803 JvmtiExport::cv_external_thread_to_JavaThread(ThreadsList * t_list,
 804                                               jthread thread,
 805                                               JavaThread ** jt_pp,
 806                                               oop * thread_oop_p) {
 807   assert(t_list != nullptr, "must have a ThreadsList");
 808   assert(jt_pp != nullptr, "must have a return JavaThread pointer");
 809   // thread_oop_p is optional so no assert()
 810 
 811   if (thread_oop_p != nullptr) {
 812     *thread_oop_p = nullptr;
 813   }
 814 
 815   oop thread_oop = JNIHandles::resolve_external_guard(thread);
 816   if (thread_oop == nullptr) {
 817     // null jthread, GC'ed jthread or a bad JNI handle.
 818     return JVMTI_ERROR_INVALID_THREAD;
 819   }
 820   // Looks like an oop at this point.
 821 
 822   if (!thread_oop->is_a(vmClasses::Thread_klass())) {
 823     // The oop is not a java.lang.Thread.
 824     return JVMTI_ERROR_INVALID_THREAD;
 825   }
 826   // Looks like a java.lang.Thread oop at this point.
 827 
 828   if (thread_oop_p != nullptr) {
 829     // Return the oop to the caller; the caller may still want
 830     // the oop even if this function returns an error.
 831     *thread_oop_p = thread_oop;
 832   }
 833 
 834   JavaThread * java_thread = java_lang_Thread::thread(thread_oop);
 835   if (java_thread == nullptr) {
 836     if (java_lang_VirtualThread::is_instance(thread_oop)) {
 837       return JVMTI_ERROR_INVALID_THREAD;
 838     }
 839     // The java.lang.Thread does not contain a JavaThread * so it has
 840     // not yet run or it has died.
 841     return JVMTI_ERROR_THREAD_NOT_ALIVE;
 842   }
 843   // Looks like a live JavaThread at this point.
 844 
 845   if (!t_list->includes(java_thread)) {
 846     // Not on the JavaThreads list so it is not alive.
 847     return JVMTI_ERROR_THREAD_NOT_ALIVE;
 848   }
 849 
 850   // Return a live JavaThread that is "protected" by the
 851   // ThreadsListHandle in the caller.
 852   *jt_pp = java_thread;
 853 
 854   return JVMTI_ERROR_NONE;
 855 }
 856 
 857 // Convert an oop to a JavaThread found on the specified ThreadsList.
 858 // The ThreadsListHandle in the caller "protects" the returned
 859 // JavaThread *.
 860 //
 861 // On success, *jt_pp is set to the converted JavaThread * and
 862 // JVMTI_ERROR_NONE is returned. On error, returns various
 863 // JVMTI_ERROR_* values.
 864 //
 865 jvmtiError
 866 JvmtiExport::cv_oop_to_JavaThread(ThreadsList * t_list, oop thread_oop,
 867                                   JavaThread ** jt_pp) {
 868   assert(t_list != nullptr, "must have a ThreadsList");
 869   assert(thread_oop != nullptr, "must have an oop");
 870   assert(jt_pp != nullptr, "must have a return JavaThread pointer");
 871 
 872   if (!thread_oop->is_a(vmClasses::Thread_klass())) {
 873     // The oop is not a java.lang.Thread.
 874     return JVMTI_ERROR_INVALID_THREAD;
 875   }
 876   // Looks like a java.lang.Thread oop at this point.
 877 
 878   JavaThread * java_thread = java_lang_Thread::thread(thread_oop);
 879   if (java_thread == nullptr) {
 880     // The java.lang.Thread does not contain a JavaThread * so it has
 881     // not yet run or it has died.
 882     return JVMTI_ERROR_THREAD_NOT_ALIVE;
 883   }
 884   // Looks like a live JavaThread at this point.
 885 
 886   if (!t_list->includes(java_thread)) {
 887     // Not on the JavaThreads list so it is not alive.
 888     return JVMTI_ERROR_THREAD_NOT_ALIVE;
 889   }
 890 
 891   // Return a live JavaThread that is "protected" by the
 892   // ThreadsListHandle in the caller.
 893   *jt_pp = java_thread;
 894 
 895   return JVMTI_ERROR_NONE;
 896 }
 897 
 898 class JvmtiClassFileLoadHookPoster : public StackObj {
 899  private:
 900   Symbol*            _h_name;
 901   Handle               _class_loader;
 902   Handle               _h_protection_domain;
 903   unsigned char **     _data_ptr;
 904   unsigned char **     _end_ptr;
 905   JavaThread *         _thread;
 906   jint                 _curr_len;
 907   unsigned char *      _curr_data;
 908   JvmtiEnv *           _curr_env;
 909   JvmtiCachedClassFileData ** _cached_class_file_ptr;
 910   JvmtiThreadState *   _state;
 911   Klass*               _class_being_redefined;
 912   JvmtiClassLoadKind   _load_kind;
 913   bool                 _has_been_modified;
 914 
 915  public:
 916   inline JvmtiClassFileLoadHookPoster(Symbol* h_name, Handle class_loader,
 917                                       Handle h_protection_domain,
 918                                       unsigned char **data_ptr, unsigned char **end_ptr,
 919                                       JvmtiCachedClassFileData **cache_ptr) {
 920     _h_name = h_name;
 921     _class_loader = class_loader;
 922     _h_protection_domain = h_protection_domain;
 923     _data_ptr = data_ptr;
 924     _end_ptr = end_ptr;
 925     _thread = JavaThread::current();
 926     _curr_len = pointer_delta_as_int(*end_ptr, *data_ptr);
 927     _curr_data = *data_ptr;
 928     _curr_env = nullptr;
 929     _cached_class_file_ptr = cache_ptr;
 930     _has_been_modified = false;
 931 
 932     assert(!_thread->is_in_any_VTMS_transition(), "CFLH events are not allowed in any VTMS transition");
 933 
 934     _state = JvmtiExport::get_jvmti_thread_state(_thread);
 935     if (_state != nullptr) {
 936       _class_being_redefined = _state->get_class_being_redefined();
 937       _load_kind = _state->get_class_load_kind();
 938       Klass* klass = (_class_being_redefined == nullptr) ? nullptr : _class_being_redefined;
 939       if (_load_kind != jvmti_class_load_kind_load && klass != nullptr) {
 940         ModuleEntry* module_entry = InstanceKlass::cast(klass)->module();
 941         assert(module_entry != nullptr, "module_entry should always be set");
 942         if (module_entry->is_named() &&
 943             module_entry->module() != nullptr &&
 944             !module_entry->has_default_read_edges()) {
 945           if (!module_entry->set_has_default_read_edges()) {
 946             // We won a potential race.
 947             // Add read edges to the unnamed modules of the bootstrap and app class loaders
 948             Handle class_module(_thread, module_entry->module()); // Obtain j.l.r.Module
 949             JvmtiExport::add_default_read_edges(class_module, _thread);
 950           }
 951         }
 952       }
 953       // Clear class_being_redefined flag here. The action
 954       // from agent handler could generate a new class file load
 955       // hook event and if it is not cleared the new event generated
 956       // from regular class file load could have this stale redefined
 957       // class handle info.
 958       _state->clear_class_being_redefined();
 959     } else {
 960       // redefine and retransform will always set the thread state
 961       _class_being_redefined = nullptr;
 962       _load_kind = jvmti_class_load_kind_load;
 963     }
 964   }
 965 
 966   void post() {
 967     post_all_envs();
 968     copy_modified_data();
 969   }
 970 
 971   bool has_been_modified() { return _has_been_modified; }
 972 
 973  private:
 974   void post_all_envs() {
 975     if (_load_kind != jvmti_class_load_kind_retransform) {
 976       // for class load and redefine,
 977       // call the non-retransformable agents
 978       JvmtiEnvIterator it;
 979       for (JvmtiEnv* env = it.first(); env != nullptr; env = it.next(env)) {
 980         if (!env->is_retransformable() && env->is_enabled(JVMTI_EVENT_CLASS_FILE_LOAD_HOOK)) {
 981           // non-retransformable agents cannot retransform back,
 982           // so no need to cache the original class file bytes
 983           post_to_env(env, false);
 984         }
 985       }
 986     }
 987     JvmtiEnvIterator it;
 988     for (JvmtiEnv* env = it.first(); env != nullptr; env = it.next(env)) {
 989       // retransformable agents get all events
 990       if (env->is_retransformable() && env->is_enabled(JVMTI_EVENT_CLASS_FILE_LOAD_HOOK)) {
 991         // retransformable agents need to cache the original class file
 992         // bytes if changes are made via the ClassFileLoadHook
 993         post_to_env(env, true);
 994       }
 995     }
 996   }
 997 
 998   void post_to_env(JvmtiEnv* env, bool caching_needed) {
 999     if (env->phase() == JVMTI_PHASE_PRIMORDIAL && !env->early_class_hook_env()) {
1000       return;
1001     }
1002     unsigned char *new_data = nullptr;
1003     jint new_len = 0;
1004     JvmtiClassFileLoadEventMark jem(_thread, _h_name, _class_loader,
1005                                     _h_protection_domain,
1006                                     _class_being_redefined);
1007     JvmtiJavaThreadEventTransition jet(_thread);
1008     jvmtiEventClassFileLoadHook callback = env->callbacks()->ClassFileLoadHook;
1009     if (callback != nullptr) {
1010       (*callback)(env->jvmti_external(), jem.jni_env(),
1011                   jem.class_being_redefined(),
1012                   jem.jloader(), jem.class_name(),
1013                   jem.protection_domain(),
1014                   _curr_len, _curr_data,
1015                   &new_len, &new_data);
1016     }
1017     if (new_data != nullptr) {
1018       // this agent has modified class data.
1019       _has_been_modified = true;
1020       if (caching_needed && *_cached_class_file_ptr == nullptr) {
1021         // data has been changed by the new retransformable agent
1022         // and it hasn't already been cached, cache it
1023         JvmtiCachedClassFileData *p;
1024         p = (JvmtiCachedClassFileData *)os::malloc(
1025           offset_of(JvmtiCachedClassFileData, data) + _curr_len, mtInternal);
1026         if (p == nullptr) {
1027           vm_exit_out_of_memory(offset_of(JvmtiCachedClassFileData, data) + _curr_len,
1028             OOM_MALLOC_ERROR,
1029             "unable to allocate cached copy of original class bytes");
1030         }
1031         p->length = _curr_len;
1032         memcpy(p->data, _curr_data, _curr_len);
1033         *_cached_class_file_ptr = p;
1034       }
1035 
1036       if (_curr_data != *_data_ptr) {
1037         // curr_data is previous agent modified class data.
1038         // And this has been changed by the new agent so
1039         // we can delete it now.
1040         _curr_env->Deallocate(_curr_data);
1041       }
1042 
1043       // Class file data has changed by the current agent.
1044       _curr_data = new_data;
1045       _curr_len = new_len;
1046       // Save the current agent env we need this to deallocate the
1047       // memory allocated by this agent.
1048       _curr_env = env;
1049     }
1050   }
1051 
1052   void copy_modified_data() {
1053     // if one of the agent has modified class file data.
1054     // Copy modified class data to new resources array.
1055     if (_curr_data != *_data_ptr) {
1056       *_data_ptr = NEW_RESOURCE_ARRAY(u1, _curr_len);
1057       memcpy(*_data_ptr, _curr_data, _curr_len);
1058       *_end_ptr = *_data_ptr + _curr_len;
1059       _curr_env->Deallocate(_curr_data);
1060     }
1061   }
1062 };
1063 
1064 bool JvmtiExport::is_early_phase() {
1065   return JvmtiEnvBase::get_phase() <= JVMTI_PHASE_PRIMORDIAL;
1066 }
1067 
1068 bool JvmtiExport::has_early_class_hook_env() {
1069   JvmtiEnvIterator it;
1070   for (JvmtiEnv* env = it.first(); env != nullptr; env = it.next(env)) {
1071     if (env->early_class_hook_env()) {
1072       return true;
1073     }
1074   }
1075   return false;
1076 }
1077 
1078 bool JvmtiExport::_should_post_class_file_load_hook = false;
1079 
1080 // This flag is read by C2 during VM internal objects allocation
1081 int JvmtiExport::_should_notify_object_alloc = 0;
1082 
1083 // this entry is for class file load hook on class load, redefine and retransform
1084 bool JvmtiExport::post_class_file_load_hook(Symbol* h_name,
1085                                             Handle class_loader,
1086                                             Handle h_protection_domain,
1087                                             unsigned char **data_ptr,
1088                                             unsigned char **end_ptr,
1089                                             JvmtiCachedClassFileData **cache_ptr) {
1090   if (JvmtiEnv::get_phase() < JVMTI_PHASE_PRIMORDIAL) {
1091     return false;
1092   }
1093 
1094   if (JavaThread::current()->is_in_any_VTMS_transition()) {
1095     return false; // no events should be posted if thread is in any VTMS transition
1096   }
1097 
1098   JvmtiClassFileLoadHookPoster poster(h_name, class_loader,
1099                                       h_protection_domain,
1100                                       data_ptr, end_ptr,
1101                                       cache_ptr);
1102   poster.post();
1103   return poster.has_been_modified();
1104 }
1105 
1106 void JvmtiExport::report_unsupported(bool on) {
1107   // If any JVMTI service is turned on, we need to exit before native code
1108   // tries to access nonexistent services.
1109   if (on) {
1110     vm_exit_during_initialization("Java Kernel does not support JVMTI.");
1111   }
1112 }
1113 
1114 
1115 static inline Klass* oop_to_klass(oop obj) {
1116   Klass* k = obj->klass();
1117 
1118   // if the object is a java.lang.Class then return the java mirror
1119   if (k == vmClasses::Class_klass()) {
1120     if (!java_lang_Class::is_primitive(obj)) {
1121       k = java_lang_Class::as_Klass(obj);
1122       assert(k != nullptr, "class for non-primitive mirror must exist");
1123     }
1124   }
1125   return k;
1126 }
1127 
1128 class JvmtiObjectAllocEventMark : public JvmtiClassEventMark  {
1129  private:
1130    jobject _jobj;
1131    jlong    _size;
1132  public:
1133    JvmtiObjectAllocEventMark(JavaThread *thread, oop obj) : JvmtiClassEventMark(thread, oop_to_klass(obj)) {
1134      _jobj = (jobject)to_jobject(obj);
1135      _size = obj->size() * wordSize;
1136    };
1137    jobject jni_jobject() { return _jobj; }
1138    jlong size() { return _size; }
1139 };
1140 
1141 class JvmtiCompiledMethodLoadEventMark : public JvmtiMethodEventMark {
1142  private:
1143   jint _code_size;
1144   const void *_code_data;
1145   jint _map_length;
1146   jvmtiAddrLocationMap *_map;
1147   const void *_compile_info;
1148  public:
1149   JvmtiCompiledMethodLoadEventMark(JavaThread *thread, nmethod *nm, void* compile_info_ptr = nullptr)
1150           : JvmtiMethodEventMark(thread,methodHandle(thread, nm->method())) {
1151     _code_data = nm->code_begin();
1152     _code_size = nm->code_size();
1153     _compile_info = compile_info_ptr; // Set void pointer of compiledMethodLoad Event. Default value is null.
1154     JvmtiCodeBlobEvents::build_jvmti_addr_location_map(nm, &_map, &_map_length);
1155   }
1156   ~JvmtiCompiledMethodLoadEventMark() {
1157      FREE_C_HEAP_ARRAY(jvmtiAddrLocationMap, _map);
1158   }
1159 
1160   jint code_size() { return _code_size; }
1161   const void *code_data() { return _code_data; }
1162   jint map_length() { return _map_length; }
1163   const jvmtiAddrLocationMap* map() { return _map; }
1164   const void *compile_info() { return _compile_info; }
1165 };
1166 
1167 
1168 
1169 class JvmtiMonitorEventMark : public JvmtiVirtualThreadEventMark {
1170 private:
1171   jobject _jobj;
1172 public:
1173   JvmtiMonitorEventMark(JavaThread *thread, oop object)
1174           : JvmtiVirtualThreadEventMark(thread){
1175      _jobj = to_jobject(object);
1176   }
1177   jobject jni_object() { return _jobj; }
1178 };
1179 
1180 ///////////////////////////////////////////////////////////////
1181 //
1182 // pending CompiledMethodUnload support
1183 //
1184 
1185 void JvmtiExport::post_compiled_method_unload(
1186        jmethodID method, const void *code_begin) {
1187   if (JvmtiEnv::get_phase() < JVMTI_PHASE_PRIMORDIAL) {
1188     return;
1189   }
1190   JavaThread* thread = JavaThread::current();
1191   EVT_TRIG_TRACE(JVMTI_EVENT_COMPILED_METHOD_UNLOAD,
1192                  ("[%s] method compile unload event triggered",
1193                   JvmtiTrace::safe_get_thread_name(thread)));
1194 
1195   // post the event for each environment that has this event enabled.
1196   JvmtiEnvIterator it;
1197   for (JvmtiEnv* env = it.first(); env != nullptr; env = it.next(env)) {
1198     if (env->is_enabled(JVMTI_EVENT_COMPILED_METHOD_UNLOAD)) {
1199       if (env->phase() == JVMTI_PHASE_PRIMORDIAL) {
1200         continue;
1201       }
1202       EVT_TRACE(JVMTI_EVENT_COMPILED_METHOD_UNLOAD,
1203                 ("[%s] class compile method unload event sent jmethodID " PTR_FORMAT,
1204                  JvmtiTrace::safe_get_thread_name(thread), p2i(method)));
1205 
1206       ResourceMark rm(thread);
1207 
1208       JvmtiEventMark jem(thread);
1209       JvmtiJavaThreadEventTransition jet(thread);
1210       jvmtiEventCompiledMethodUnload callback = env->callbacks()->CompiledMethodUnload;
1211       if (callback != nullptr) {
1212         (*callback)(env->jvmti_external(), method, code_begin);
1213       }
1214     }
1215   }
1216 }
1217 
1218 ///////////////////////////////////////////////////////////////
1219 //
1220 // JvmtiExport
1221 //
1222 
1223 void JvmtiExport::post_raw_breakpoint(JavaThread *thread, Method* method, address location) {
1224   HandleMark hm(thread);
1225   methodHandle mh(thread, method);
1226 
1227   JvmtiThreadState *state = get_jvmti_thread_state(thread);
1228   if (state == nullptr) {
1229     return;
1230   }
1231   if (thread->is_in_any_VTMS_transition()) {
1232     return; // no events should be posted if thread is in any VTMS transition
1233   }
1234 
1235   EVT_TRIG_TRACE(JVMTI_EVENT_BREAKPOINT, ("[%s] Trg Breakpoint triggered",
1236                       JvmtiTrace::safe_get_thread_name(thread)));
1237   JvmtiEnvThreadStateIterator it(state);
1238   for (JvmtiEnvThreadState* ets = it.first(); ets != nullptr; ets = it.next(ets)) {
1239     ets->compare_and_set_current_location(mh(), location, JVMTI_EVENT_BREAKPOINT);
1240     if (!ets->breakpoint_posted() && ets->is_enabled(JVMTI_EVENT_BREAKPOINT)) {
1241       ThreadState old_os_state = thread->osthread()->get_state();
1242       thread->osthread()->set_state(BREAKPOINTED);
1243       EVT_TRACE(JVMTI_EVENT_BREAKPOINT, ("[%s] Evt Breakpoint sent %s.%s @ " INTX_FORMAT,
1244                      JvmtiTrace::safe_get_thread_name(thread),
1245                      (mh() == nullptr) ? "null" : mh()->klass_name()->as_C_string(),
1246                      (mh() == nullptr) ? "null" : mh()->name()->as_C_string(),
1247                      location - mh()->code_base() ));
1248 
1249       JvmtiEnv *env = ets->get_env();
1250       JvmtiLocationEventMark jem(thread, mh, location);
1251       JvmtiJavaThreadEventTransition jet(thread);
1252       jvmtiEventBreakpoint callback = env->callbacks()->Breakpoint;
1253       if (callback != nullptr) {
1254         (*callback)(env->jvmti_external(), jem.jni_env(), jem.jni_thread(),
1255                     jem.jni_methodID(), jem.location());
1256       }
1257 
1258       ets->set_breakpoint_posted();
1259       thread->osthread()->set_state(old_os_state);
1260     }
1261   }
1262 }
1263 
1264 //////////////////////////////////////////////////////////////////////////////
1265 
1266 bool              JvmtiExport::_can_get_source_debug_extension            = false;
1267 bool              JvmtiExport::_can_maintain_original_method_order        = false;
1268 bool              JvmtiExport::_can_post_interpreter_events               = false;
1269 bool              JvmtiExport::_can_post_on_exceptions                    = false;
1270 bool              JvmtiExport::_can_post_breakpoint                       = false;
1271 bool              JvmtiExport::_can_post_field_access                     = false;
1272 bool              JvmtiExport::_can_post_field_modification               = false;
1273 bool              JvmtiExport::_can_post_method_entry                     = false;
1274 bool              JvmtiExport::_can_post_method_exit                      = false;
1275 bool              JvmtiExport::_can_post_frame_pop                        = false;
1276 bool              JvmtiExport::_can_pop_frame                             = false;
1277 bool              JvmtiExport::_can_force_early_return                    = false;
1278 bool              JvmtiExport::_can_support_virtual_threads               = false;
1279 bool              JvmtiExport::_can_get_owned_monitor_info                = false;
1280 
1281 bool              JvmtiExport::_early_vmstart_recorded                    = false;
1282 
1283 bool              JvmtiExport::_should_post_single_step                   = false;
1284 bool              JvmtiExport::_should_post_field_access                  = false;
1285 bool              JvmtiExport::_should_post_field_modification            = false;
1286 bool              JvmtiExport::_should_post_class_load                    = false;
1287 bool              JvmtiExport::_should_post_class_prepare                 = false;
1288 bool              JvmtiExport::_should_post_class_unload                  = false;
1289 bool              JvmtiExport::_should_post_thread_life                   = false;
1290 bool              JvmtiExport::_should_clean_up_heap_objects              = false;
1291 bool              JvmtiExport::_should_post_native_method_bind            = false;
1292 bool              JvmtiExport::_should_post_dynamic_code_generated        = false;
1293 bool              JvmtiExport::_should_post_data_dump                     = false;
1294 bool              JvmtiExport::_should_post_compiled_method_load          = false;
1295 bool              JvmtiExport::_should_post_compiled_method_unload        = false;
1296 bool              JvmtiExport::_should_post_monitor_contended_enter       = false;
1297 bool              JvmtiExport::_should_post_monitor_contended_entered     = false;
1298 bool              JvmtiExport::_should_post_monitor_wait                  = false;
1299 bool              JvmtiExport::_should_post_monitor_waited                = false;
1300 bool              JvmtiExport::_should_post_garbage_collection_start      = false;
1301 bool              JvmtiExport::_should_post_garbage_collection_finish     = false;
1302 bool              JvmtiExport::_should_post_object_free                   = false;
1303 bool              JvmtiExport::_should_post_resource_exhausted            = false;
1304 bool              JvmtiExport::_should_post_vm_object_alloc               = false;
1305 bool              JvmtiExport::_should_post_sampled_object_alloc          = false;
1306 bool              JvmtiExport::_should_post_on_exceptions                 = false;
1307 bool              JvmtiExport::_should_post_vthread_start                 = false;
1308 bool              JvmtiExport::_should_post_vthread_end                   = false;
1309 bool              JvmtiExport::_should_post_vthread_mount                 = false;
1310 bool              JvmtiExport::_should_post_vthread_unmount               = false;
1311 
1312 ////////////////////////////////////////////////////////////////////////////////////////////////
1313 
1314 
1315 //
1316 // JVMTI single step management
1317 //
1318 void JvmtiExport::at_single_stepping_point(JavaThread *thread, Method* method, address location) {
1319   assert(JvmtiExport::should_post_single_step(), "must be single stepping");
1320 
1321   HandleMark hm(thread);
1322   methodHandle mh(thread, method);
1323 
1324   // update information about current location and post a step event
1325   JvmtiThreadState *state = get_jvmti_thread_state(thread);
1326   if (state == nullptr) {
1327     return;
1328   }
1329   EVT_TRIG_TRACE(JVMTI_EVENT_SINGLE_STEP, ("[%s] Trg Single Step triggered",
1330                       JvmtiTrace::safe_get_thread_name(thread)));
1331   if (!state->hide_single_stepping()) {
1332     if (state->is_pending_step_for_popframe()) {
1333       state->process_pending_step_for_popframe();
1334     }
1335     if (state->is_pending_step_for_earlyret()) {
1336       state->process_pending_step_for_earlyret();
1337     }
1338     JvmtiExport::post_single_step(thread, mh(), location);
1339   }
1340 }
1341 
1342 
1343 void JvmtiExport::expose_single_stepping(JavaThread *thread) {
1344   JvmtiThreadState *state = get_jvmti_thread_state(thread);
1345   if (state != nullptr) {
1346     state->clear_hide_single_stepping();
1347   }
1348 }
1349 
1350 
1351 bool JvmtiExport::hide_single_stepping(JavaThread *thread) {
1352   JvmtiThreadState *state = get_jvmti_thread_state(thread);
1353   if (state != nullptr && state->is_enabled(JVMTI_EVENT_SINGLE_STEP)) {
1354     state->set_hide_single_stepping();
1355     return true;
1356   } else {
1357     return false;
1358   }
1359 }
1360 
1361 void JvmtiExport::post_class_load(JavaThread *thread, Klass* klass) {
1362   if (JvmtiEnv::get_phase() < JVMTI_PHASE_PRIMORDIAL) {
1363     return;
1364   }
1365   HandleMark hm(thread);
1366 
1367   JvmtiThreadState *state = get_jvmti_thread_state(thread);
1368   if (state == nullptr) {
1369     return;
1370   }
1371   if (thread->is_in_any_VTMS_transition()) {
1372     return; // no events should be posted if thread is in any VTMS transition
1373   }
1374 
1375   EVT_TRIG_TRACE(JVMTI_EVENT_CLASS_LOAD, ("[%s] Trg Class Load triggered",
1376                       JvmtiTrace::safe_get_thread_name(thread)));
1377   JvmtiEnvThreadStateIterator it(state);
1378   for (JvmtiEnvThreadState* ets = it.first(); ets != nullptr; ets = it.next(ets)) {
1379     if (ets->is_enabled(JVMTI_EVENT_CLASS_LOAD)) {
1380       JvmtiEnv *env = ets->get_env();
1381       if (env->phase() == JVMTI_PHASE_PRIMORDIAL) {
1382         continue;
1383       }
1384       EVT_TRACE(JVMTI_EVENT_CLASS_LOAD, ("[%s] Evt Class Load sent %s",
1385                                          JvmtiTrace::safe_get_thread_name(thread),
1386                                          klass==nullptr? "null" : klass->external_name() ));
1387       JvmtiClassEventMark jem(thread, klass);
1388       JvmtiJavaThreadEventTransition jet(thread);
1389       jvmtiEventClassLoad callback = env->callbacks()->ClassLoad;
1390       if (callback != nullptr) {
1391         (*callback)(env->jvmti_external(), jem.jni_env(), jem.jni_thread(), jem.jni_class());
1392       }
1393     }
1394   }
1395 }
1396 
1397 
1398 void JvmtiExport::post_class_prepare(JavaThread *thread, Klass* klass) {
1399   if (JvmtiEnv::get_phase() < JVMTI_PHASE_PRIMORDIAL) {
1400     return;
1401   }
1402   HandleMark hm(thread);
1403 
1404   JvmtiThreadState *state = get_jvmti_thread_state(thread);
1405   if (state == nullptr) {
1406     return;
1407   }
1408   if (thread->is_in_any_VTMS_transition()) {
1409     return; // no events should be posted if thread is in any VTMS transition
1410   }
1411 
1412   EVT_TRIG_TRACE(JVMTI_EVENT_CLASS_PREPARE, ("[%s] Trg Class Prepare triggered",
1413                       JvmtiTrace::safe_get_thread_name(thread)));
1414   JvmtiEnvThreadStateIterator it(state);
1415   for (JvmtiEnvThreadState* ets = it.first(); ets != nullptr; ets = it.next(ets)) {
1416     if (ets->is_enabled(JVMTI_EVENT_CLASS_PREPARE)) {
1417       JvmtiEnv *env = ets->get_env();
1418       if (env->phase() == JVMTI_PHASE_PRIMORDIAL) {
1419         continue;
1420       }
1421       EVT_TRACE(JVMTI_EVENT_CLASS_PREPARE, ("[%s] Evt Class Prepare sent %s",
1422                                             JvmtiTrace::safe_get_thread_name(thread),
1423                                             klass==nullptr? "null" : klass->external_name() ));
1424       JvmtiClassEventMark jem(thread, klass);
1425       JvmtiJavaThreadEventTransition jet(thread);
1426       jvmtiEventClassPrepare callback = env->callbacks()->ClassPrepare;
1427       if (callback != nullptr) {
1428         (*callback)(env->jvmti_external(), jem.jni_env(), jem.jni_thread(), jem.jni_class());
1429       }
1430     }
1431   }
1432 }
1433 
1434 void JvmtiExport::post_class_unload(Klass* klass) {
1435   if (JvmtiEnv::get_phase() < JVMTI_PHASE_PRIMORDIAL) {
1436     return;
1437   }
1438 
1439   // postings to the service thread so that it can perform them in a safe
1440   // context and in-order.
1441   ResourceMark rm;
1442   // JvmtiDeferredEvent copies the string.
1443   JvmtiDeferredEvent event = JvmtiDeferredEvent::class_unload_event(klass->name()->as_C_string());
1444   ServiceThread::enqueue_deferred_event(&event);
1445 }
1446 
1447 
1448 void JvmtiExport::post_class_unload_internal(const char* name) {
1449   if (JvmtiEnv::get_phase() < JVMTI_PHASE_PRIMORDIAL) {
1450     return;
1451   }
1452   assert(Thread::current()->is_service_thread(), "must be called from ServiceThread");
1453   JavaThread *thread = JavaThread::current();
1454   HandleMark hm(thread);
1455 
1456   EVT_TRIG_TRACE(EXT_EVENT_CLASS_UNLOAD, ("[?] Trg Class Unload triggered" ));
1457   if (JvmtiEventController::is_enabled((jvmtiEvent)EXT_EVENT_CLASS_UNLOAD)) {
1458 
1459     JvmtiEnvIterator it;
1460     for (JvmtiEnv* env = it.first(); env != nullptr; env = it.next(env)) {
1461       if (env->phase() == JVMTI_PHASE_PRIMORDIAL) {
1462         continue;
1463       }
1464       if (env->is_enabled((jvmtiEvent)EXT_EVENT_CLASS_UNLOAD)) {
1465         EVT_TRACE(EXT_EVENT_CLASS_UNLOAD, ("[?] Evt Class Unload sent %s", name));
1466 
1467         JvmtiEventMark jem(thread);
1468         JvmtiJavaThreadEventTransition jet(thread);
1469         jvmtiExtensionEvent callback = env->ext_callbacks()->ClassUnload;
1470         if (callback != nullptr) {
1471           (*callback)(env->jvmti_external(), jem.jni_env(), name);
1472         }
1473       }
1474     }
1475   }
1476 }
1477 
1478 
1479 void JvmtiExport::post_thread_start(JavaThread *thread) {
1480   if (JvmtiEnv::get_phase() < JVMTI_PHASE_PRIMORDIAL) {
1481     return;
1482   }
1483   assert(thread->thread_state() == _thread_in_vm, "must be in vm state");
1484 
1485   EVT_TRIG_TRACE(JVMTI_EVENT_THREAD_START, ("[%s] Trg Thread Start event triggered",
1486                       JvmtiTrace::safe_get_thread_name(thread)));
1487 
1488   // do JVMTI thread initialization (if needed)
1489   JvmtiEventController::thread_started(thread);
1490 
1491   if (thread->threadObj()->is_a(vmClasses::BoundVirtualThread_klass())) {
1492     if (JvmtiExport::can_support_virtual_threads()) {
1493       // Check for VirtualThreadStart event instead.
1494       HandleMark hm(thread);
1495       Handle vthread(thread, thread->threadObj());
1496       JvmtiExport::post_vthread_start((jthread)vthread.raw_value());
1497     }
1498     return;
1499   }
1500 
1501   // Do not post thread start event for hidden java thread.
1502   if (JvmtiEventController::is_enabled(JVMTI_EVENT_THREAD_START) &&
1503       !thread->is_hidden_from_external_view()) {
1504     JvmtiEnvIterator it;
1505     for (JvmtiEnv* env = it.first(); env != nullptr; env = it.next(env)) {
1506       if (env->phase() == JVMTI_PHASE_PRIMORDIAL) {
1507         continue;
1508       }
1509       if (env->is_enabled(JVMTI_EVENT_THREAD_START)) {
1510         EVT_TRACE(JVMTI_EVENT_THREAD_START, ("[%s] Evt Thread Start event sent",
1511                      JvmtiTrace::safe_get_thread_name(thread) ));
1512 
1513         JvmtiVirtualThreadEventMark jem(thread);
1514         JvmtiJavaThreadEventTransition jet(thread);
1515         jvmtiEventThreadStart callback = env->callbacks()->ThreadStart;
1516         if (callback != nullptr) {
1517           (*callback)(env->jvmti_external(), jem.jni_env(), jem.jni_thread());
1518         }
1519       }
1520     }
1521   }
1522 }
1523 
1524 
1525 void JvmtiExport::post_thread_end(JavaThread *thread) {
1526   if (JvmtiEnv::get_phase() < JVMTI_PHASE_PRIMORDIAL) {
1527     return;
1528   }
1529   EVT_TRIG_TRACE(JVMTI_EVENT_THREAD_END, ("[%s] Trg Thread End event triggered",
1530                       JvmtiTrace::safe_get_thread_name(thread)));
1531 
1532   JvmtiThreadState *state = get_jvmti_thread_state(thread);
1533   if (state == nullptr) {
1534     return;
1535   }
1536 
1537   if (thread->threadObj()->is_a(vmClasses::BoundVirtualThread_klass())) {
1538     if (JvmtiExport::can_support_virtual_threads()) {
1539       // Check for VirtualThreadEnd event instead.
1540       HandleMark hm(thread);
1541       Handle vthread(thread, thread->threadObj());
1542       JvmtiExport::post_vthread_end((jthread)vthread.raw_value());
1543     }
1544     return;
1545   }
1546 
1547   // Do not post thread end event for hidden java thread.
1548   if (state->is_enabled(JVMTI_EVENT_THREAD_END) &&
1549       !thread->is_hidden_from_external_view()) {
1550 
1551     JvmtiEnvThreadStateIterator it(state);
1552     for (JvmtiEnvThreadState* ets = it.first(); ets != nullptr; ets = it.next(ets)) {
1553       JvmtiEnv *env = ets->get_env();
1554       if (env->phase() == JVMTI_PHASE_PRIMORDIAL) {
1555         continue;
1556       }
1557       if (ets->is_enabled(JVMTI_EVENT_THREAD_END)) {
1558         EVT_TRACE(JVMTI_EVENT_THREAD_END, ("[%s] Evt Thread End event sent",
1559                      JvmtiTrace::safe_get_thread_name(thread) ));
1560 
1561         JvmtiVirtualThreadEventMark jem(thread);
1562         JvmtiJavaThreadEventTransition jet(thread);
1563         jvmtiEventThreadEnd callback = env->callbacks()->ThreadEnd;
1564         if (callback != nullptr) {
1565           (*callback)(env->jvmti_external(), jem.jni_env(), jem.jni_thread());
1566         }
1567       }
1568     }
1569   }
1570 }
1571 
1572 
1573 void JvmtiExport::post_vthread_start(jobject vthread) {
1574   if (JvmtiEnv::get_phase() < JVMTI_PHASE_PRIMORDIAL) {
1575     return;
1576   }
1577   EVT_TRIG_TRACE(JVMTI_EVENT_VIRTUAL_THREAD_START, ("[%p] Trg Virtual Thread Start event triggered", vthread));
1578 
1579   JavaThread *thread = JavaThread::current();
1580   assert(!thread->is_hidden_from_external_view(), "carrier threads can't be hidden");
1581 
1582   if (JvmtiEventController::is_enabled(JVMTI_EVENT_VIRTUAL_THREAD_START)) {
1583     JvmtiEnvIterator it;
1584     for (JvmtiEnv* env = it.first(); env != nullptr; env = it.next(env)) {
1585       if (env->phase() == JVMTI_PHASE_PRIMORDIAL) {
1586         continue;
1587       }
1588       if (env->is_enabled(JVMTI_EVENT_VIRTUAL_THREAD_START)) {
1589         EVT_TRACE(JVMTI_EVENT_VIRTUAL_THREAD_START, ("[%p] Evt Virtual Thread Start event sent", vthread));
1590 
1591         JvmtiVirtualThreadEventMark jem(thread);
1592         JvmtiJavaThreadEventTransition jet(thread);
1593         jvmtiEventVirtualThreadStart callback = env->callbacks()->VirtualThreadStart;
1594         if (callback != nullptr) {
1595           (*callback)(env->jvmti_external(), jem.jni_env(), jem.jni_thread());
1596         }
1597       }
1598     }
1599   }
1600 }
1601 
1602 void JvmtiExport::post_vthread_end(jobject vthread) {
1603   if (JvmtiEnv::get_phase() < JVMTI_PHASE_PRIMORDIAL) {
1604     return;
1605   }
1606   EVT_TRIG_TRACE(JVMTI_EVENT_VIRTUAL_THREAD_END, ("[%p] Trg Virtual Thread End event triggered", vthread));
1607 
1608   JavaThread *thread = JavaThread::current();
1609   assert(!thread->is_hidden_from_external_view(), "carrier threads can't be hidden");
1610 
1611   JvmtiThreadState *state = get_jvmti_thread_state(thread);
1612   if (state == nullptr) {
1613     return;
1614   }
1615 
1616   if (state->is_enabled(JVMTI_EVENT_VIRTUAL_THREAD_END)) {
1617     JvmtiEnvThreadStateIterator it(state);
1618 
1619     for (JvmtiEnvThreadState* ets = it.first(); ets != nullptr; ets = it.next(ets)) {
1620       JvmtiEnv *env = ets->get_env();
1621       if (env->phase() == JVMTI_PHASE_PRIMORDIAL) {
1622         continue;
1623       }
1624       if (ets->is_enabled(JVMTI_EVENT_VIRTUAL_THREAD_END)) {
1625         EVT_TRACE(JVMTI_EVENT_VIRTUAL_THREAD_END, ("[%p] Evt Virtual Thread End event sent", vthread));
1626 
1627         JvmtiVirtualThreadEventMark jem(thread);
1628         JvmtiJavaThreadEventTransition jet(thread);
1629         jvmtiEventVirtualThreadEnd callback = env->callbacks()->VirtualThreadEnd;
1630         if (callback != nullptr) {
1631           (*callback)(env->jvmti_external(), jem.jni_env(), vthread);
1632         }
1633       }
1634     }
1635   }
1636 }
1637 
1638 void JvmtiExport::post_vthread_mount(jobject vthread) {
1639   if (JvmtiEnv::get_phase() < JVMTI_PHASE_PRIMORDIAL) {
1640     return;
1641   }
1642   JavaThread *thread = JavaThread::current();
1643   HandleMark hm(thread);
1644   EVT_TRIG_TRACE(EXT_EVENT_VIRTUAL_THREAD_MOUNT, ("[%p] Trg Virtual Thread Mount event triggered", vthread));
1645 
1646   JvmtiThreadState *state = get_jvmti_thread_state(thread);
1647   if (state == nullptr) {
1648     return;
1649   }
1650 
1651   if (state->is_enabled((jvmtiEvent)EXT_EVENT_VIRTUAL_THREAD_MOUNT)) {
1652     JvmtiEnvThreadStateIterator it(state);
1653 
1654     for (JvmtiEnvThreadState* ets = it.first(); ets != nullptr; ets = it.next(ets)) {
1655       JvmtiEnv *env = ets->get_env();
1656       if (env->phase() == JVMTI_PHASE_PRIMORDIAL) {
1657         continue;
1658       }
1659       if (ets->is_enabled((jvmtiEvent)EXT_EVENT_VIRTUAL_THREAD_MOUNT)) {
1660         EVT_TRACE(EXT_EVENT_VIRTUAL_THREAD_MOUNT, ("[%p] Evt Virtual Thread Mount event sent", vthread));
1661 
1662         JvmtiVirtualThreadEventMark jem(thread);
1663         JvmtiJavaThreadEventTransition jet(thread);
1664         jvmtiExtensionEvent callback = env->ext_callbacks()->VirtualThreadMount;
1665         if (callback != nullptr) {
1666           (*callback)(env->jvmti_external(), jem.jni_env(), jem.jni_thread());
1667         }
1668       }
1669     }
1670   }
1671 }
1672 
1673 void JvmtiExport::post_vthread_unmount(jobject vthread) {
1674   if (JvmtiEnv::get_phase() < JVMTI_PHASE_PRIMORDIAL) {
1675     return;
1676   }
1677   JavaThread *thread = JavaThread::current();
1678   HandleMark hm(thread);
1679   EVT_TRIG_TRACE(EXT_EVENT_VIRTUAL_THREAD_UNMOUNT, ("[%p] Trg Virtual Thread Unmount event triggered", vthread));
1680 
1681   JvmtiThreadState *state = get_jvmti_thread_state(thread);
1682   if (state == nullptr) {
1683     return;
1684   }
1685 
1686   if (state->is_enabled((jvmtiEvent)EXT_EVENT_VIRTUAL_THREAD_UNMOUNT)) {
1687     JvmtiEnvThreadStateIterator it(state);
1688 
1689     for (JvmtiEnvThreadState* ets = it.first(); ets != nullptr; ets = it.next(ets)) {
1690       JvmtiEnv *env = ets->get_env();
1691       if (env->phase() == JVMTI_PHASE_PRIMORDIAL) {
1692         continue;
1693       }
1694       if (ets->is_enabled((jvmtiEvent)EXT_EVENT_VIRTUAL_THREAD_UNMOUNT)) {
1695         EVT_TRACE(EXT_EVENT_VIRTUAL_THREAD_UNMOUNT, ("[%p] Evt Virtual Thread Unmount event sent", vthread));
1696 
1697         JvmtiVirtualThreadEventMark jem(thread);
1698         JvmtiJavaThreadEventTransition jet(thread);
1699         jvmtiExtensionEvent callback = env->ext_callbacks()->VirtualThreadUnmount;
1700         if (callback != nullptr) {
1701           (*callback)(env->jvmti_external(), jem.jni_env(), jem.jni_thread());
1702         }
1703       }
1704     }
1705   }
1706 }
1707 
1708 void JvmtiExport::continuation_yield_cleanup(JavaThread* thread, jint continuation_frame_count) {
1709   if (JvmtiEnv::get_phase() < JVMTI_PHASE_PRIMORDIAL) {
1710     return;
1711   }
1712 
1713   assert(thread == JavaThread::current(), "must be");
1714   JvmtiThreadState *state = get_jvmti_thread_state(thread);
1715   if (state == nullptr) {
1716     return;
1717   }
1718   state->invalidate_cur_stack_depth();
1719 
1720   // Clear frame_pop requests in frames popped by yield
1721   if (can_post_frame_pop()) {
1722     JvmtiEnvThreadStateIterator it(state);
1723     int top_frame_num = state->cur_stack_depth() + continuation_frame_count;
1724 
1725     for (JvmtiEnvThreadState* ets = it.first(); ets != nullptr; ets = it.next(ets)) {
1726       if (!ets->has_frame_pops()) {
1727         continue;
1728       }
1729       for (int frame_idx = 0; frame_idx < continuation_frame_count; frame_idx++) {
1730         int frame_num = top_frame_num - frame_idx;
1731 
1732         if (!state->is_virtual() && ets->is_frame_pop(frame_num)) {
1733           // remove the frame's entry
1734           MutexLocker mu(JvmtiThreadState_lock);
1735           ets->clear_frame_pop(frame_num);
1736         }
1737       }
1738     }
1739   }
1740 }
1741 
1742 void JvmtiExport::post_object_free(JvmtiEnv* env, GrowableArray<jlong>* objects) {
1743   assert(objects != nullptr, "Nothing to post");
1744 
1745   JavaThread *javaThread = JavaThread::current();
1746   if (javaThread->is_in_any_VTMS_transition()) {
1747     return; // no events should be posted if thread is in any VTMS transition
1748   }
1749   if (!env->is_enabled(JVMTI_EVENT_OBJECT_FREE)) {
1750     return; // the event type has been already disabled
1751   }
1752 
1753   EVT_TRIG_TRACE(JVMTI_EVENT_OBJECT_FREE, ("[?] Trg Object Free triggered" ));
1754   EVT_TRACE(JVMTI_EVENT_OBJECT_FREE, ("[?] Evt Object Free sent"));
1755 
1756   JvmtiThreadEventMark jem(javaThread);
1757   JvmtiJavaThreadEventTransition jet(javaThread);
1758   jvmtiEventObjectFree callback = env->callbacks()->ObjectFree;
1759   if (callback != nullptr) {
1760     for (int index = 0; index < objects->length(); index++) {
1761       (*callback)(env->jvmti_external(), objects->at(index));
1762     }
1763   }
1764 }
1765 
1766 void JvmtiExport::post_resource_exhausted(jint resource_exhausted_flags, const char* description) {
1767 
1768   JavaThread *thread  = JavaThread::current();
1769 
1770   if (thread->is_in_any_VTMS_transition()) {
1771     return; // no events should be posted if thread is in any VTMS transition
1772   }
1773 
1774   log_error(jvmti)("Posting Resource Exhausted event: %s",
1775                    description != nullptr ? description : "unknown");
1776 
1777   // JDK-8213834: handlers of ResourceExhausted may attempt some analysis
1778   // which often requires running java.
1779   // This will cause problems on threads not able to run java, e.g. compiler
1780   // threads. To forestall these problems, we therefore suppress sending this
1781   // event from threads which are not able to run java.
1782   if (!thread->can_call_java()) {
1783     return;
1784   }
1785 
1786   EVT_TRIG_TRACE(JVMTI_EVENT_RESOURCE_EXHAUSTED, ("Trg resource exhausted event triggered" ));
1787 
1788   JvmtiEnvIterator it;
1789   for (JvmtiEnv* env = it.first(); env != nullptr; env = it.next(env)) {
1790     if (env->is_enabled(JVMTI_EVENT_RESOURCE_EXHAUSTED)) {
1791       EVT_TRACE(JVMTI_EVENT_RESOURCE_EXHAUSTED, ("Evt resource exhausted event sent" ));
1792 
1793       JvmtiThreadEventMark jem(thread);
1794       JvmtiJavaThreadEventTransition jet(thread);
1795       jvmtiEventResourceExhausted callback = env->callbacks()->ResourceExhausted;
1796       if (callback != nullptr) {
1797         (*callback)(env->jvmti_external(), jem.jni_env(),
1798                     resource_exhausted_flags, nullptr, description);
1799       }
1800     }
1801   }
1802 }
1803 
1804 void JvmtiExport::post_method_entry(JavaThread *thread, Method* method, frame current_frame) {
1805   HandleMark hm(thread);
1806   methodHandle mh(thread, method);
1807 
1808   JvmtiThreadState *state = get_jvmti_thread_state(thread);
1809   if (state == nullptr || !state->is_interp_only_mode()) {
1810     // for any thread that actually wants method entry, interp_only_mode is set
1811     return;
1812   }
1813   if (mh->jvmti_mount_transition() || thread->is_in_any_VTMS_transition()) {
1814     return; // no events should be posted if thread is in any VTMS transition
1815   }
1816   EVT_TRIG_TRACE(JVMTI_EVENT_METHOD_ENTRY, ("[%s] Trg Method Entry triggered %s.%s",
1817                      JvmtiTrace::safe_get_thread_name(thread),
1818                      (mh() == nullptr) ? "null" : mh()->klass_name()->as_C_string(),
1819                      (mh() == nullptr) ? "null" : mh()->name()->as_C_string() ));
1820 
1821   state->incr_cur_stack_depth();
1822 
1823   if (state->is_enabled(JVMTI_EVENT_METHOD_ENTRY)) {
1824     JvmtiEnvThreadStateIterator it(state);
1825     for (JvmtiEnvThreadState* ets = it.first(); ets != nullptr; ets = it.next(ets)) {
1826       if (ets->is_enabled(JVMTI_EVENT_METHOD_ENTRY)) {
1827         EVT_TRACE(JVMTI_EVENT_METHOD_ENTRY, ("[%s] Evt Method Entry sent %s.%s",
1828                                              JvmtiTrace::safe_get_thread_name(thread),
1829                                              (mh() == nullptr) ? "null" : mh()->klass_name()->as_C_string(),
1830                                              (mh() == nullptr) ? "null" : mh()->name()->as_C_string() ));
1831 
1832         JvmtiEnv *env = ets->get_env();
1833         JvmtiMethodEventMark jem(thread, mh);
1834         JvmtiJavaThreadEventTransition jet(thread);
1835         jvmtiEventMethodEntry callback = env->callbacks()->MethodEntry;
1836         if (callback != nullptr) {
1837           (*callback)(env->jvmti_external(), jem.jni_env(), jem.jni_thread(), jem.jni_methodID());
1838         }
1839       }
1840     }
1841   }
1842 }
1843 
1844 void JvmtiExport::post_method_exit(JavaThread* thread, Method* method, frame current_frame) {
1845   HandleMark hm(thread);
1846   methodHandle mh(thread, method);
1847 
1848   JvmtiThreadState *state = get_jvmti_thread_state(thread);
1849 
1850   if (state == nullptr || !state->is_interp_only_mode()) {
1851     // for any thread that actually wants method exit, interp_only_mode is set
1852     return;
1853   }
1854 
1855   // return a flag when a method terminates by throwing an exception
1856   // i.e. if an exception is thrown and it's not caught by the current method
1857   bool exception_exit = state->is_exception_detected() && !state->is_exception_caught();
1858   Handle result;
1859   jvalue value;
1860   value.j = 0L;
1861 
1862   if (state->is_enabled(JVMTI_EVENT_METHOD_EXIT)) {
1863     // if the method hasn't been popped because of an exception then we populate
1864     // the return_value parameter for the callback. At this point we only have
1865     // the address of a "raw result" and we just call into the interpreter to
1866     // convert this into a jvalue.
1867     if (!exception_exit) {
1868       oop oop_result;
1869       BasicType type = current_frame.interpreter_frame_result(&oop_result, &value);
1870       if (is_reference_type(type)) {
1871         result = Handle(thread, oop_result);
1872         value.l = JNIHandles::make_local(thread, result());
1873       }
1874     }
1875   }
1876 
1877   // Deferred transition to VM, so we can stash away the return oop before GC
1878   // Note that this transition is not needed when throwing an exception, because
1879   // there is no oop to retain.
1880   JavaThread* current = thread; // for JRT_BLOCK
1881   JRT_BLOCK
1882     post_method_exit_inner(thread, mh, state, exception_exit, current_frame, value);
1883   JRT_BLOCK_END
1884 
1885   if (result.not_null() && !mh->is_native()) {
1886     // We have to restore the oop on the stack for interpreter frames
1887     *(oop*)current_frame.interpreter_frame_tos_address() = result();
1888   }
1889 }
1890 
1891 void JvmtiExport::post_method_exit_inner(JavaThread* thread,
1892                                          methodHandle& mh,
1893                                          JvmtiThreadState *state,
1894                                          bool exception_exit,
1895                                          frame current_frame,
1896                                          jvalue& value) {
1897   if (mh->jvmti_mount_transition() || thread->is_in_any_VTMS_transition()) {
1898     return; // no events should be posted if thread is in any VTMS transition
1899   }
1900 
1901   EVT_TRIG_TRACE(JVMTI_EVENT_METHOD_EXIT, ("[%s] Trg Method Exit triggered %s.%s",
1902                                            JvmtiTrace::safe_get_thread_name(thread),
1903                                            (mh() == nullptr) ? "null" : mh()->klass_name()->as_C_string(),
1904                                            (mh() == nullptr) ? "null" : mh()->name()->as_C_string() ));
1905 
1906   if (state->is_enabled(JVMTI_EVENT_METHOD_EXIT)) {
1907     JvmtiEnvThreadStateIterator it(state);
1908     for (JvmtiEnvThreadState* ets = it.first(); ets != nullptr; ets = it.next(ets)) {
1909       if (ets->is_enabled(JVMTI_EVENT_METHOD_EXIT)) {
1910         EVT_TRACE(JVMTI_EVENT_METHOD_EXIT, ("[%s] Evt Method Exit sent %s.%s",
1911                                             JvmtiTrace::safe_get_thread_name(thread),
1912                                             (mh() == nullptr) ? "null" : mh()->klass_name()->as_C_string(),
1913                                             (mh() == nullptr) ? "null" : mh()->name()->as_C_string() ));
1914 
1915         JvmtiEnv *env = ets->get_env();
1916         JvmtiMethodEventMark jem(thread, mh);
1917         JvmtiJavaThreadEventTransition jet(thread);
1918         jvmtiEventMethodExit callback = env->callbacks()->MethodExit;
1919         if (callback != nullptr) {
1920           (*callback)(env->jvmti_external(), jem.jni_env(), jem.jni_thread(),
1921                       jem.jni_methodID(), exception_exit,  value);
1922         }
1923       }
1924     }
1925   }
1926 
1927   JvmtiEnvThreadStateIterator it(state);
1928   for (JvmtiEnvThreadState* ets = it.first(); ets != nullptr; ets = it.next(ets)) {
1929     if (ets->has_frame_pops()) {
1930       int cur_frame_number = state->cur_stack_depth();
1931 
1932       if (ets->is_frame_pop(cur_frame_number)) {
1933         // we have a NotifyFramePop entry for this frame.
1934         // now check that this env/thread wants this event
1935         if (ets->is_enabled(JVMTI_EVENT_FRAME_POP)) {
1936           EVT_TRACE(JVMTI_EVENT_FRAME_POP, ("[%s] Evt Frame Pop sent %s.%s",
1937                                             JvmtiTrace::safe_get_thread_name(thread),
1938                                             (mh() == nullptr) ? "null" : mh()->klass_name()->as_C_string(),
1939                                             (mh() == nullptr) ? "null" : mh()->name()->as_C_string() ));
1940 
1941           // we also need to issue a frame pop event for this frame
1942           JvmtiEnv *env = ets->get_env();
1943           JvmtiMethodEventMark jem(thread, mh);
1944           JvmtiJavaThreadEventTransition jet(thread);
1945           jvmtiEventFramePop callback = env->callbacks()->FramePop;
1946           if (callback != nullptr) {
1947             (*callback)(env->jvmti_external(), jem.jni_env(), jem.jni_thread(),
1948                         jem.jni_methodID(), exception_exit);
1949           }
1950         }
1951         // remove the frame's entry
1952         {
1953           MutexLocker mu(JvmtiThreadState_lock);
1954           ets->clear_frame_pop(cur_frame_number);
1955         }
1956       }
1957     }
1958   }
1959 
1960   state->decr_cur_stack_depth();
1961 }
1962 
1963 
1964 // Todo: inline this for optimization
1965 void JvmtiExport::post_single_step(JavaThread *thread, Method* method, address location) {
1966   HandleMark hm(thread);
1967   methodHandle mh(thread, method);
1968 
1969   JvmtiThreadState *state = get_jvmti_thread_state(thread);
1970   if (state == nullptr) {
1971     return;
1972   }
1973   if (mh->jvmti_mount_transition() || thread->is_in_any_VTMS_transition()) {
1974     return; // no events should be posted if thread is in any VTMS transition
1975   }
1976 
1977   JvmtiEnvThreadStateIterator it(state);
1978   for (JvmtiEnvThreadState* ets = it.first(); ets != nullptr; ets = it.next(ets)) {
1979     ets->compare_and_set_current_location(mh(), location, JVMTI_EVENT_SINGLE_STEP);
1980     if (!ets->single_stepping_posted() && ets->is_enabled(JVMTI_EVENT_SINGLE_STEP)) {
1981       EVT_TRACE(JVMTI_EVENT_SINGLE_STEP, ("[%s] Evt Single Step sent %s.%s @ " INTX_FORMAT,
1982                     JvmtiTrace::safe_get_thread_name(thread),
1983                     (mh() == nullptr) ? "null" : mh()->klass_name()->as_C_string(),
1984                     (mh() == nullptr) ? "null" : mh()->name()->as_C_string(),
1985                     location - mh()->code_base() ));
1986 
1987       JvmtiEnv *env = ets->get_env();
1988       JvmtiLocationEventMark jem(thread, mh, location);
1989       JvmtiJavaThreadEventTransition jet(thread);
1990       jvmtiEventSingleStep callback = env->callbacks()->SingleStep;
1991       if (callback != nullptr) {
1992         (*callback)(env->jvmti_external(), jem.jni_env(), jem.jni_thread(),
1993                     jem.jni_methodID(), jem.location());
1994       }
1995 
1996       ets->set_single_stepping_posted();
1997     }
1998   }
1999 }
2000 
2001 void JvmtiExport::post_exception_throw(JavaThread *thread, Method* method, address location, oop exception) {
2002   HandleMark hm(thread);
2003   methodHandle mh(thread, method);
2004   Handle exception_handle(thread, exception);
2005   // The KeepStackGCProcessedMark below keeps the target thread and its stack fully
2006   // GC processed across this scope. This is needed because there is a stack walk
2007   // below with safepoint polls inside of it. After such safepoints, we have to
2008   // ensure the stack is sufficiently processed.
2009   KeepStackGCProcessedMark ksgcpm(thread);
2010 
2011   JvmtiThreadState *state = get_jvmti_thread_state(thread);
2012   if (state == nullptr) {
2013     return;
2014   }
2015   if (thread->is_in_any_VTMS_transition()) {
2016     return; // no events should be posted if thread is in any VTMS transition
2017   }
2018 
2019   EVT_TRIG_TRACE(JVMTI_EVENT_EXCEPTION, ("[%s] Trg Exception thrown triggered",
2020                       JvmtiTrace::safe_get_thread_name(thread)));
2021   if (!state->is_exception_detected()) {
2022     state->set_exception_detected();
2023     JvmtiEnvThreadStateIterator it(state);
2024     for (JvmtiEnvThreadState* ets = it.first(); ets != nullptr; ets = it.next(ets)) {
2025       if (ets->is_enabled(JVMTI_EVENT_EXCEPTION) && (exception != nullptr)) {
2026 
2027         EVT_TRACE(JVMTI_EVENT_EXCEPTION,
2028                      ("[%s] Evt Exception thrown sent %s.%s @ " INTX_FORMAT,
2029                       JvmtiTrace::safe_get_thread_name(thread),
2030                       (mh() == nullptr) ? "null" : mh()->klass_name()->as_C_string(),
2031                       (mh() == nullptr) ? "null" : mh()->name()->as_C_string(),
2032                       location - mh()->code_base() ));
2033 
2034         JvmtiEnv *env = ets->get_env();
2035         JvmtiExceptionEventMark jem(thread, mh, location, exception_handle);
2036 
2037         // It's okay to clear these exceptions here because we duplicate
2038         // this lookup in InterpreterRuntime::exception_handler_for_exception.
2039         EXCEPTION_MARK;
2040 
2041         bool should_repeat;
2042         vframeStream st(thread);
2043         assert(!st.at_end(), "cannot be at end");
2044         Method* current_method = nullptr;
2045         // A GC may occur during the Method::fast_exception_handler_bci_for()
2046         // call below if it needs to load the constraint class. Using a
2047         // methodHandle to keep the 'current_method' from being deallocated
2048         // if GC happens.
2049         methodHandle current_mh = methodHandle(thread, current_method);
2050         int current_bci = -1;
2051         do {
2052           current_method = st.method();
2053           current_mh = methodHandle(thread, current_method);
2054           current_bci = st.bci();
2055           do {
2056             should_repeat = false;
2057             Klass* eh_klass = exception_handle()->klass();
2058             current_bci = Method::fast_exception_handler_bci_for(
2059               current_mh, eh_klass, current_bci, THREAD);
2060             if (HAS_PENDING_EXCEPTION) {
2061               exception_handle = Handle(thread, PENDING_EXCEPTION);
2062               CLEAR_PENDING_EXCEPTION;
2063               should_repeat = true;
2064             }
2065           } while (should_repeat && (current_bci != -1));
2066           st.next();
2067         } while ((current_bci < 0) && (!st.at_end()));
2068 
2069         jmethodID catch_jmethodID;
2070         if (current_bci < 0) {
2071           catch_jmethodID = nullptr;
2072           current_bci = 0;
2073         } else {
2074           catch_jmethodID = jem.to_jmethodID(current_mh);
2075         }
2076 
2077         JvmtiJavaThreadEventTransition jet(thread);
2078         jvmtiEventException callback = env->callbacks()->Exception;
2079         if (callback != nullptr) {
2080           (*callback)(env->jvmti_external(), jem.jni_env(), jem.jni_thread(),
2081                       jem.jni_methodID(), jem.location(),
2082                       jem.exception(),
2083                       catch_jmethodID, current_bci);
2084         }
2085       }
2086     }
2087   }
2088 
2089   // frames may get popped because of this throw, be safe - invalidate cached depth
2090   state->invalidate_cur_stack_depth();
2091 }
2092 
2093 
2094 void JvmtiExport::notice_unwind_due_to_exception(JavaThread *thread, Method* method, address location, oop exception, bool in_handler_frame) {
2095   HandleMark hm(thread);
2096   methodHandle mh(thread, method);
2097   Handle exception_handle(thread, exception);
2098 
2099   JvmtiThreadState *state = get_jvmti_thread_state(thread);
2100   if (state == nullptr) {
2101     return;
2102   }
2103   EVT_TRIG_TRACE(JVMTI_EVENT_EXCEPTION_CATCH,
2104                     ("[%s] Trg unwind_due_to_exception triggered %s.%s @ %s" INTX_FORMAT " - %s",
2105                      JvmtiTrace::safe_get_thread_name(thread),
2106                      (mh() == nullptr) ? "null" : mh()->klass_name()->as_C_string(),
2107                      (mh() == nullptr) ? "null" : mh()->name()->as_C_string(),
2108                      location == nullptr ? "no location:" : "",
2109                      location == nullptr ? 0 : location - mh()->code_base(),
2110                      in_handler_frame? "in handler frame" : "not handler frame" ));
2111 
2112   if (state->is_exception_detected()) {
2113 
2114     state->invalidate_cur_stack_depth();
2115     if (!in_handler_frame) {
2116       // Not in exception handler.
2117       if(state->is_interp_only_mode()) {
2118         // method exit and frame pop events are posted only in interp mode.
2119         // When these events are enabled code should be in running in interp mode.
2120         jvalue no_value;
2121         no_value.j = 0L;
2122         JvmtiExport::post_method_exit_inner(thread, mh, state, true, thread->last_frame(), no_value);
2123         // The cached cur_stack_depth might have changed from the
2124         // operations of frame pop or method exit. We are not 100% sure
2125         // the cached cur_stack_depth is still valid depth so invalidate
2126         // it.
2127         state->invalidate_cur_stack_depth();
2128       }
2129     } else {
2130       // In exception handler frame. Report exception catch.
2131       assert(location != nullptr, "must be a known location");
2132       // Update cur_stack_depth - the frames above the current frame
2133       // have been unwound due to this exception:
2134       assert(!state->is_exception_caught(), "exception must not be caught yet.");
2135       state->set_exception_caught();
2136 
2137       if (mh->jvmti_mount_transition() || thread->is_in_any_VTMS_transition()) {
2138         return; // no events should be posted if thread is in any VTMS transition
2139       }
2140       JvmtiEnvThreadStateIterator it(state);
2141       for (JvmtiEnvThreadState* ets = it.first(); ets != nullptr; ets = it.next(ets)) {
2142         if (ets->is_enabled(JVMTI_EVENT_EXCEPTION_CATCH) && (exception_handle() != nullptr)) {
2143           EVT_TRACE(JVMTI_EVENT_EXCEPTION_CATCH,
2144                      ("[%s] Evt ExceptionCatch sent %s.%s @ " INTX_FORMAT,
2145                       JvmtiTrace::safe_get_thread_name(thread),
2146                       (mh() == nullptr) ? "null" : mh()->klass_name()->as_C_string(),
2147                       (mh() == nullptr) ? "null" : mh()->name()->as_C_string(),
2148                       location - mh()->code_base() ));
2149 
2150           JvmtiEnv *env = ets->get_env();
2151           JvmtiExceptionEventMark jem(thread, mh, location, exception_handle);
2152           JvmtiJavaThreadEventTransition jet(thread);
2153           jvmtiEventExceptionCatch callback = env->callbacks()->ExceptionCatch;
2154           if (callback != nullptr) {
2155             (*callback)(env->jvmti_external(), jem.jni_env(), jem.jni_thread(),
2156                       jem.jni_methodID(), jem.location(),
2157                       jem.exception());
2158           }
2159         }
2160       }
2161     }
2162   }
2163 }
2164 
2165 oop JvmtiExport::jni_GetField_probe(JavaThread *thread, jobject jobj, oop obj,
2166                                     Klass* klass, jfieldID fieldID, bool is_static) {
2167   if (*((int *)get_field_access_count_addr()) > 0 && thread->has_last_Java_frame()) {
2168     // At least one field access watch is set so we have more work to do.
2169     post_field_access_by_jni(thread, obj, klass, fieldID, is_static);
2170     // event posting can block so refetch oop if we were passed a jobj
2171     if (jobj != nullptr) return JNIHandles::resolve_non_null(jobj);
2172   }
2173   return obj;
2174 }
2175 
2176 void JvmtiExport::post_field_access_by_jni(JavaThread *thread, oop obj,
2177                                            Klass* klass, jfieldID fieldID, bool is_static) {
2178   // We must be called with a Java context in order to provide reasonable
2179   // values for the klazz, method, and location fields. The callers of this
2180   // function don't make the call unless there is a Java context.
2181   assert(thread->has_last_Java_frame(), "must be called with a Java context");
2182 
2183   if (thread->is_in_any_VTMS_transition()) {
2184     return; // no events should be posted if thread is in any VTMS transition
2185   }
2186 
2187   ResourceMark rm;
2188   fieldDescriptor fd;
2189   // if get_field_descriptor finds fieldID to be invalid, then we just bail
2190   bool valid_fieldID = JvmtiEnv::get_field_descriptor(klass, fieldID, &fd);
2191   assert(valid_fieldID == true,"post_field_access_by_jni called with invalid fieldID");
2192   if (!valid_fieldID) return;
2193   // field accesses are not watched so bail
2194   if (!fd.is_field_access_watched()) return;
2195 
2196   HandleMark hm(thread);
2197   Handle h_obj;
2198   if (!is_static) {
2199     // non-static field accessors have an object, but we need a handle
2200     assert(obj != nullptr, "non-static needs an object");
2201     h_obj = Handle(thread, obj);
2202   }
2203   post_field_access(thread,
2204                     thread->last_frame().interpreter_frame_method(),
2205                     thread->last_frame().interpreter_frame_bcp(),
2206                     klass, h_obj, fieldID);
2207 }
2208 
2209 void JvmtiExport::post_field_access(JavaThread *thread, Method* method,
2210   address location, Klass* field_klass, Handle object, jfieldID field) {
2211 
2212   HandleMark hm(thread);
2213   methodHandle mh(thread, method);
2214 
2215   JvmtiThreadState *state = get_jvmti_thread_state(thread);
2216   if (state == nullptr) {
2217     return;
2218   }
2219   if (thread->is_in_any_VTMS_transition()) {
2220     return; // no events should be posted if thread is in any VTMS transition
2221   }
2222 
2223   EVT_TRIG_TRACE(JVMTI_EVENT_FIELD_ACCESS, ("[%s] Trg Field Access event triggered",
2224                       JvmtiTrace::safe_get_thread_name(thread)));
2225   JvmtiEnvThreadStateIterator it(state);
2226   for (JvmtiEnvThreadState* ets = it.first(); ets != nullptr; ets = it.next(ets)) {
2227     if (ets->is_enabled(JVMTI_EVENT_FIELD_ACCESS)) {
2228       EVT_TRACE(JVMTI_EVENT_FIELD_ACCESS, ("[%s] Evt Field Access event sent %s.%s @ " INTX_FORMAT,
2229                      JvmtiTrace::safe_get_thread_name(thread),
2230                      (mh() == nullptr) ? "null" : mh()->klass_name()->as_C_string(),
2231                      (mh() == nullptr) ? "null" : mh()->name()->as_C_string(),
2232                      location - mh()->code_base() ));
2233 
2234       JvmtiEnv *env = ets->get_env();
2235       JvmtiLocationEventMark jem(thread, mh, location);
2236       jclass field_jclass = jem.to_jclass(field_klass);
2237       jobject field_jobject = jem.to_jobject(object());
2238       JvmtiJavaThreadEventTransition jet(thread);
2239       jvmtiEventFieldAccess callback = env->callbacks()->FieldAccess;
2240       if (callback != nullptr) {
2241         (*callback)(env->jvmti_external(), jem.jni_env(), jem.jni_thread(),
2242                     jem.jni_methodID(), jem.location(),
2243                     field_jclass, field_jobject, field);
2244       }
2245     }
2246   }
2247 }
2248 
2249 oop JvmtiExport::jni_SetField_probe(JavaThread *thread, jobject jobj, oop obj,
2250                                     Klass* klass, jfieldID fieldID, bool is_static,
2251                                     char sig_type, jvalue *value) {
2252   if (*((int *)get_field_modification_count_addr()) > 0 && thread->has_last_Java_frame()) {
2253     // At least one field modification watch is set so we have more work to do.
2254     post_field_modification_by_jni(thread, obj, klass, fieldID, is_static, sig_type, value);
2255     // event posting can block so refetch oop if we were passed a jobj
2256     if (jobj != nullptr) return JNIHandles::resolve_non_null(jobj);
2257   }
2258   return obj;
2259 }
2260 
2261 void JvmtiExport::post_field_modification_by_jni(JavaThread *thread, oop obj,
2262                                                  Klass* klass, jfieldID fieldID, bool is_static,
2263                                                  char sig_type, jvalue *value) {
2264   // We must be called with a Java context in order to provide reasonable
2265   // values for the klazz, method, and location fields. The callers of this
2266   // function don't make the call unless there is a Java context.
2267   assert(thread->has_last_Java_frame(), "must be called with Java context");
2268 
2269   if (thread->is_in_any_VTMS_transition()) {
2270     return; // no events should be posted if thread is in any VTMS transition
2271   }
2272 
2273   ResourceMark rm;
2274   fieldDescriptor fd;
2275   // if get_field_descriptor finds fieldID to be invalid, then we just bail
2276   bool valid_fieldID = JvmtiEnv::get_field_descriptor(klass, fieldID, &fd);
2277   assert(valid_fieldID == true,"post_field_modification_by_jni called with invalid fieldID");
2278   if (!valid_fieldID) return;
2279   // field modifications are not watched so bail
2280   if (!fd.is_field_modification_watched()) return;
2281 
2282   HandleMark hm(thread);
2283 
2284   Handle h_obj;
2285   if (!is_static) {
2286     // non-static field accessors have an object, but we need a handle
2287     assert(obj != nullptr, "non-static needs an object");
2288     h_obj = Handle(thread, obj);
2289   }
2290   post_field_modification(thread,
2291                           thread->last_frame().interpreter_frame_method(),
2292                           thread->last_frame().interpreter_frame_bcp(),
2293                           klass, h_obj, fieldID, sig_type, value);
2294 }
2295 
2296 void JvmtiExport::post_raw_field_modification(JavaThread *thread, Method* method,
2297   address location, Klass* field_klass, Handle object, jfieldID field,
2298   char sig_type, jvalue *value) {
2299 
2300   if (thread->is_in_any_VTMS_transition()) {
2301     return; // no events should be posted if thread is in any VTMS transition
2302   }
2303 
2304   if (sig_type == JVM_SIGNATURE_INT || sig_type == JVM_SIGNATURE_BOOLEAN ||
2305       sig_type == JVM_SIGNATURE_BYTE || sig_type == JVM_SIGNATURE_CHAR ||
2306       sig_type == JVM_SIGNATURE_SHORT) {
2307     // 'I' instructions are used for byte, char, short and int.
2308     // determine which it really is, and convert
2309     fieldDescriptor fd;
2310     bool found = JvmtiEnv::get_field_descriptor(field_klass, field, &fd);
2311     // should be found (if not, leave as is)
2312     if (found) {
2313       jint ival = value->i;
2314       // convert value from int to appropriate type
2315       switch (fd.field_type()) {
2316       case T_BOOLEAN:
2317         sig_type = JVM_SIGNATURE_BOOLEAN;
2318         value->i = 0; // clear it
2319         value->z = (jboolean)ival;
2320         break;
2321       case T_BYTE:
2322         sig_type = JVM_SIGNATURE_BYTE;
2323         value->i = 0; // clear it
2324         value->b = (jbyte)ival;
2325         break;
2326       case T_CHAR:
2327         sig_type = JVM_SIGNATURE_CHAR;
2328         value->i = 0; // clear it
2329         value->c = (jchar)ival;
2330         break;
2331       case T_SHORT:
2332         sig_type = JVM_SIGNATURE_SHORT;
2333         value->i = 0; // clear it
2334         value->s = (jshort)ival;
2335         break;
2336       case T_INT:
2337         // nothing to do
2338         break;
2339       default:
2340         // this is an integer instruction, should be one of above
2341         ShouldNotReachHere();
2342         break;
2343       }
2344     }
2345   }
2346 
2347   assert(sig_type != JVM_SIGNATURE_ARRAY, "array should have sig_type == 'L'");
2348   bool handle_created = false;
2349 
2350   // convert oop to JNI handle.
2351   if (sig_type == JVM_SIGNATURE_CLASS) {
2352     handle_created = true;
2353     value->l = (jobject)JNIHandles::make_local(thread, cast_to_oop(value->l));
2354   }
2355 
2356   post_field_modification(thread, method, location, field_klass, object, field, sig_type, value);
2357 
2358   // Destroy the JNI handle allocated above.
2359   if (handle_created) {
2360     JNIHandles::destroy_local(value->l);
2361   }
2362 }
2363 
2364 void JvmtiExport::post_field_modification(JavaThread *thread, Method* method,
2365   address location, Klass* field_klass, Handle object, jfieldID field,
2366   char sig_type, jvalue *value_ptr) {
2367 
2368   HandleMark hm(thread);
2369   methodHandle mh(thread, method);
2370 
2371   JvmtiThreadState *state = get_jvmti_thread_state(thread);
2372   if (state == nullptr) {
2373     return;
2374   }
2375   if (thread->is_in_any_VTMS_transition()) {
2376     return; // no events should be posted if thread is in any VTMS transition
2377   }
2378 
2379   EVT_TRIG_TRACE(JVMTI_EVENT_FIELD_MODIFICATION,
2380                      ("[%s] Trg Field Modification event triggered",
2381                       JvmtiTrace::safe_get_thread_name(thread)));
2382   JvmtiEnvThreadStateIterator it(state);
2383   for (JvmtiEnvThreadState* ets = it.first(); ets != nullptr; ets = it.next(ets)) {
2384     if (ets->is_enabled(JVMTI_EVENT_FIELD_MODIFICATION)) {
2385       EVT_TRACE(JVMTI_EVENT_FIELD_MODIFICATION,
2386                    ("[%s] Evt Field Modification event sent %s.%s @ " INTX_FORMAT,
2387                     JvmtiTrace::safe_get_thread_name(thread),
2388                     (mh() == nullptr) ? "null" : mh()->klass_name()->as_C_string(),
2389                     (mh() == nullptr) ? "null" : mh()->name()->as_C_string(),
2390                     location - mh()->code_base() ));
2391 
2392       JvmtiEnv *env = ets->get_env();
2393       JvmtiLocationEventMark jem(thread, mh, location);
2394       jclass field_jclass = jem.to_jclass(field_klass);
2395       jobject field_jobject = jem.to_jobject(object());
2396       JvmtiJavaThreadEventTransition jet(thread);
2397       jvmtiEventFieldModification callback = env->callbacks()->FieldModification;
2398       if (callback != nullptr) {
2399         (*callback)(env->jvmti_external(), jem.jni_env(), jem.jni_thread(),
2400                     jem.jni_methodID(), jem.location(),
2401                     field_jclass, field_jobject, field, sig_type, *value_ptr);
2402       }
2403     }
2404   }
2405 }
2406 
2407 void JvmtiExport::post_native_method_bind(Method* method, address* function_ptr) {
2408   JavaThread* thread = JavaThread::current();
2409   assert(thread->thread_state() == _thread_in_vm, "must be in vm state");
2410 
2411   HandleMark hm(thread);
2412   methodHandle mh(thread, method);
2413 
2414   if (thread->is_in_any_VTMS_transition()) {
2415     return; // no events should be posted if thread is in any VTMS transition
2416   }
2417   EVT_TRIG_TRACE(JVMTI_EVENT_NATIVE_METHOD_BIND, ("[%s] Trg Native Method Bind event triggered",
2418                       JvmtiTrace::safe_get_thread_name(thread)));
2419 
2420   if (JvmtiEventController::is_enabled(JVMTI_EVENT_NATIVE_METHOD_BIND)) {
2421     JvmtiEnvIterator it;
2422     for (JvmtiEnv* env = it.first(); env != nullptr; env = it.next(env)) {
2423       if (env->is_enabled(JVMTI_EVENT_NATIVE_METHOD_BIND)) {
2424         EVT_TRACE(JVMTI_EVENT_NATIVE_METHOD_BIND, ("[%s] Evt Native Method Bind event sent",
2425                      JvmtiTrace::safe_get_thread_name(thread) ));
2426 
2427         JvmtiMethodEventMark jem(thread, mh);
2428         JvmtiJavaThreadEventTransition jet(thread);
2429         JNIEnv* jni_env = (env->phase() == JVMTI_PHASE_PRIMORDIAL) ? nullptr : jem.jni_env();
2430         jvmtiEventNativeMethodBind callback = env->callbacks()->NativeMethodBind;
2431         if (callback != nullptr) {
2432           (*callback)(env->jvmti_external(), jni_env, jem.jni_thread(),
2433                       jem.jni_methodID(), (void*)(*function_ptr), (void**)function_ptr);
2434         }
2435       }
2436     }
2437   }
2438 }
2439 
2440 // Returns a record containing inlining information for the given nmethod
2441 static jvmtiCompiledMethodLoadInlineRecord* create_inline_record(nmethod* nm) {
2442   jint numstackframes = 0;
2443   jvmtiCompiledMethodLoadInlineRecord* record = (jvmtiCompiledMethodLoadInlineRecord*)NEW_RESOURCE_OBJ(jvmtiCompiledMethodLoadInlineRecord);
2444   record->header.kind = JVMTI_CMLR_INLINE_INFO;
2445   record->header.next = nullptr;
2446   record->header.majorinfoversion = JVMTI_CMLR_MAJOR_VERSION_1;
2447   record->header.minorinfoversion = JVMTI_CMLR_MINOR_VERSION_0;
2448   record->numpcs = 0;
2449   for(PcDesc* p = nm->scopes_pcs_begin(); p < nm->scopes_pcs_end(); p++) {
2450    if(p->scope_decode_offset() == DebugInformationRecorder::serialized_null) continue;
2451    record->numpcs++;
2452   }
2453   record->pcinfo = (PCStackInfo*)(NEW_RESOURCE_ARRAY(PCStackInfo, record->numpcs));
2454   int scope = 0;
2455   for(PcDesc* p = nm->scopes_pcs_begin(); p < nm->scopes_pcs_end(); p++) {
2456     if(p->scope_decode_offset() == DebugInformationRecorder::serialized_null) continue;
2457     void* pc_address = (void*)p->real_pc(nm);
2458     assert(pc_address != nullptr, "pc_address must be non-null");
2459     record->pcinfo[scope].pc = pc_address;
2460     numstackframes=0;
2461     for(ScopeDesc* sd = nm->scope_desc_at(p->real_pc(nm));sd != nullptr;sd = sd->sender()) {
2462       numstackframes++;
2463     }
2464     assert(numstackframes != 0, "numstackframes must be nonzero.");
2465     record->pcinfo[scope].methods = (jmethodID *)NEW_RESOURCE_ARRAY(jmethodID, numstackframes);
2466     record->pcinfo[scope].bcis = (jint *)NEW_RESOURCE_ARRAY(jint, numstackframes);
2467     record->pcinfo[scope].numstackframes = numstackframes;
2468     int stackframe = 0;
2469     for(ScopeDesc* sd = nm->scope_desc_at(p->real_pc(nm));sd != nullptr;sd = sd->sender()) {
2470       // sd->method() can be null for stubs but not for nmethods. To be completely robust, include an assert that we should never see a null sd->method()
2471       guarantee(sd->method() != nullptr, "sd->method() cannot be null.");
2472       record->pcinfo[scope].methods[stackframe] = sd->method()->jmethod_id();
2473       record->pcinfo[scope].bcis[stackframe] = sd->bci();
2474       stackframe++;
2475     }
2476     scope++;
2477   }
2478   return record;
2479 }
2480 
2481 void JvmtiExport::post_compiled_method_load(nmethod *nm) {
2482   guarantee(!nm->is_unloading(), "nmethod isn't unloaded or unloading");
2483   if (JvmtiEnv::get_phase() < JVMTI_PHASE_PRIMORDIAL) {
2484     return;
2485   }
2486   JavaThread* thread = JavaThread::current();
2487 
2488   assert(!thread->is_in_any_VTMS_transition(), "compiled method load events are not allowed in any VTMS transition");
2489 
2490   EVT_TRIG_TRACE(JVMTI_EVENT_COMPILED_METHOD_LOAD,
2491                  ("[%s] method compile load event triggered",
2492                  JvmtiTrace::safe_get_thread_name(thread)));
2493 
2494   JvmtiEnvIterator it;
2495   for (JvmtiEnv* env = it.first(); env != nullptr; env = it.next(env)) {
2496     post_compiled_method_load(env, nm);
2497   }
2498 }
2499 
2500 // post a COMPILED_METHOD_LOAD event for a given environment
2501 void JvmtiExport::post_compiled_method_load(JvmtiEnv* env, nmethod *nm) {
2502   if (env->phase() == JVMTI_PHASE_PRIMORDIAL || !env->is_enabled(JVMTI_EVENT_COMPILED_METHOD_LOAD)) {
2503     return;
2504   }
2505   jvmtiEventCompiledMethodLoad callback = env->callbacks()->CompiledMethodLoad;
2506   if (callback == nullptr) {
2507     return;
2508   }
2509   JavaThread* thread = JavaThread::current();
2510 
2511   assert(!thread->is_in_any_VTMS_transition(), "compiled method load events are not allowed in any VTMS transition");
2512 
2513   EVT_TRACE(JVMTI_EVENT_COMPILED_METHOD_LOAD,
2514            ("[%s] method compile load event sent %s.%s  ",
2515             JvmtiTrace::safe_get_thread_name(thread),
2516             (nm->method() == nullptr) ? "null" : nm->method()->klass_name()->as_C_string(),
2517             (nm->method() == nullptr) ? "null" : nm->method()->name()->as_C_string()));
2518   ResourceMark rm(thread);
2519   HandleMark hm(thread);
2520 
2521   // Add inlining information
2522   jvmtiCompiledMethodLoadInlineRecord* inlinerecord = create_inline_record(nm);
2523   // Pass inlining information through the void pointer
2524   JvmtiCompiledMethodLoadEventMark jem(thread, nm, inlinerecord);
2525   JvmtiJavaThreadEventTransition jet(thread);
2526   (*callback)(env->jvmti_external(), jem.jni_methodID(),
2527               jem.code_size(), jem.code_data(), jem.map_length(),
2528               jem.map(), jem.compile_info());
2529 }
2530 
2531 void JvmtiExport::post_dynamic_code_generated_internal(const char *name, const void *code_begin, const void *code_end) {
2532   assert(name != nullptr && name[0] != '\0', "sanity check");
2533 
2534   JavaThread* thread = JavaThread::current();
2535 
2536   assert(!thread->is_in_any_VTMS_transition(), "dynamic code generated events are not allowed in any VTMS transition");
2537 
2538   // In theory everyone coming thru here is in_vm but we need to be certain
2539   // because a callee will do a vm->native transition
2540   ThreadInVMfromUnknown __tiv;
2541 
2542   EVT_TRIG_TRACE(JVMTI_EVENT_DYNAMIC_CODE_GENERATED,
2543                  ("[%s] method dynamic code generated event triggered",
2544                  JvmtiTrace::safe_get_thread_name(thread)));
2545   JvmtiEnvIterator it;
2546   for (JvmtiEnv* env = it.first(); env != nullptr; env = it.next(env)) {
2547     if (env->is_enabled(JVMTI_EVENT_DYNAMIC_CODE_GENERATED)) {
2548       EVT_TRACE(JVMTI_EVENT_DYNAMIC_CODE_GENERATED,
2549                 ("[%s] dynamic code generated event sent for %s",
2550                 JvmtiTrace::safe_get_thread_name(thread), name));
2551       JvmtiEventMark jem(thread);
2552       JvmtiJavaThreadEventTransition jet(thread);
2553       jint length = (jint)pointer_delta(code_end, code_begin, sizeof(char));
2554       jvmtiEventDynamicCodeGenerated callback = env->callbacks()->DynamicCodeGenerated;
2555       if (callback != nullptr) {
2556         (*callback)(env->jvmti_external(), name, (void*)code_begin, length);
2557       }
2558     }
2559   }
2560 }
2561 
2562 void JvmtiExport::post_dynamic_code_generated(const char *name, const void *code_begin, const void *code_end) {
2563   jvmtiPhase phase = JvmtiEnv::get_phase();
2564   if (phase == JVMTI_PHASE_PRIMORDIAL || phase == JVMTI_PHASE_START) {
2565     post_dynamic_code_generated_internal(name, code_begin, code_end);
2566   } else {
2567     // It may not be safe to post the event from this thread.  Defer all
2568     // postings to the service thread so that it can perform them in a safe
2569     // context and in-order.
2570     JvmtiDeferredEvent event = JvmtiDeferredEvent::dynamic_code_generated_event(
2571         name, code_begin, code_end);
2572     ServiceThread::enqueue_deferred_event(&event);
2573   }
2574 }
2575 
2576 
2577 // post a DYNAMIC_CODE_GENERATED event for a given environment
2578 // used by GenerateEvents
2579 void JvmtiExport::post_dynamic_code_generated(JvmtiEnv* env, const char *name,
2580                                               const void *code_begin, const void *code_end)
2581 {
2582   JavaThread* thread = JavaThread::current();
2583 
2584   assert(!thread->is_in_any_VTMS_transition(), "dynamic code generated events are not allowed in any VTMS transition");
2585 
2586   EVT_TRIG_TRACE(JVMTI_EVENT_DYNAMIC_CODE_GENERATED,
2587                  ("[%s] dynamic code generated event triggered (by GenerateEvents)",
2588                   JvmtiTrace::safe_get_thread_name(thread)));
2589   if (env->is_enabled(JVMTI_EVENT_DYNAMIC_CODE_GENERATED)) {
2590     EVT_TRACE(JVMTI_EVENT_DYNAMIC_CODE_GENERATED,
2591               ("[%s] dynamic code generated event sent for %s",
2592                JvmtiTrace::safe_get_thread_name(thread), name));
2593     JvmtiEventMark jem(thread);
2594     JvmtiJavaThreadEventTransition jet(thread);
2595     jint length = (jint)pointer_delta(code_end, code_begin, sizeof(char));
2596     jvmtiEventDynamicCodeGenerated callback = env->callbacks()->DynamicCodeGenerated;
2597     if (callback != nullptr) {
2598       (*callback)(env->jvmti_external(), name, (void*)code_begin, length);
2599     }
2600   }
2601 }
2602 
2603 // post a DynamicCodeGenerated event while holding locks in the VM.
2604 void JvmtiExport::post_dynamic_code_generated_while_holding_locks(const char* name,
2605                                                                   address code_begin, address code_end)
2606 {
2607   JavaThread* thread = JavaThread::current();
2608   // register the stub with the current dynamic code event collector
2609   // Cannot take safepoint here so do not use state_for to get
2610   // jvmti thread state.
2611   // The collector and/or state might be null if JvmtiDynamicCodeEventCollector
2612   // has been initialized while JVMTI_EVENT_DYNAMIC_CODE_GENERATED was disabled.
2613   JvmtiThreadState *state = get_jvmti_thread_state(thread);
2614   if (state != nullptr) {
2615     JvmtiDynamicCodeEventCollector *collector = state->get_dynamic_code_event_collector();
2616     if (collector != nullptr) {
2617       collector->register_stub(name, code_begin, code_end);
2618     }
2619   }
2620 }
2621 
2622 // Collect all the vm internally allocated objects which are visible to java world
2623 void JvmtiExport::record_vm_internal_object_allocation(oop obj) {
2624   Thread* thread = Thread::current_or_null();
2625   if (thread != nullptr && thread->is_Java_thread())  {
2626     // Can not take safepoint here.
2627     NoSafepointVerifier no_sfpt;
2628     // Cannot take safepoint here so do not use state_for to get
2629     // jvmti thread state.
2630     JvmtiThreadState *state = JavaThread::cast(thread)->jvmti_thread_state();
2631     if (state != nullptr) {
2632       // state is non null when VMObjectAllocEventCollector is enabled.
2633       JvmtiVMObjectAllocEventCollector *collector;
2634       collector = state->get_vm_object_alloc_event_collector();
2635       if (collector != nullptr && collector->is_enabled()) {
2636         // Don't record classes as these will be notified via the ClassLoad
2637         // event.
2638         if (obj->klass() != vmClasses::Class_klass()) {
2639           collector->record_allocation(obj);
2640         }
2641       }
2642     }
2643   }
2644 }
2645 
2646 // Collect all the sampled allocated objects.
2647 void JvmtiExport::record_sampled_internal_object_allocation(oop obj) {
2648   Thread* thread = Thread::current_or_null();
2649   if (thread != nullptr && thread->is_Java_thread())  {
2650     // Can not take safepoint here.
2651     NoSafepointVerifier no_sfpt;
2652     // Cannot take safepoint here so do not use state_for to get
2653     // jvmti thread state.
2654     JvmtiThreadState *state = JavaThread::cast(thread)->jvmti_thread_state();
2655     if (state != nullptr) {
2656       // state is non null when SampledObjectAllocEventCollector is enabled.
2657       JvmtiSampledObjectAllocEventCollector *collector;
2658       collector = state->get_sampled_object_alloc_event_collector();
2659 
2660       if (collector != nullptr && collector->is_enabled()) {
2661         collector->record_allocation(obj);
2662       }
2663     }
2664   }
2665 }
2666 
2667 void JvmtiExport::post_garbage_collection_finish() {
2668   Thread *thread = Thread::current(); // this event is posted from VM-Thread.
2669   EVT_TRIG_TRACE(JVMTI_EVENT_GARBAGE_COLLECTION_FINISH,
2670                  ("[%s] garbage collection finish event triggered",
2671                   JvmtiTrace::safe_get_thread_name(thread)));
2672   JvmtiEnvIterator it;
2673   for (JvmtiEnv* env = it.first(); env != nullptr; env = it.next(env)) {
2674     if (env->is_enabled(JVMTI_EVENT_GARBAGE_COLLECTION_FINISH)) {
2675       EVT_TRACE(JVMTI_EVENT_GARBAGE_COLLECTION_FINISH,
2676                 ("[%s] garbage collection finish event sent",
2677                  JvmtiTrace::safe_get_thread_name(thread)));
2678       JvmtiThreadEventTransition jet(thread);
2679       // JNIEnv is null here because this event is posted from VM Thread
2680       jvmtiEventGarbageCollectionFinish callback = env->callbacks()->GarbageCollectionFinish;
2681       if (callback != nullptr) {
2682         (*callback)(env->jvmti_external());
2683       }
2684     }
2685   }
2686 }
2687 
2688 void JvmtiExport::post_garbage_collection_start() {
2689   Thread* thread = Thread::current(); // this event is posted from vm-thread.
2690   EVT_TRIG_TRACE(JVMTI_EVENT_GARBAGE_COLLECTION_START,
2691                  ("[%s] garbage collection start event triggered",
2692                   JvmtiTrace::safe_get_thread_name(thread)));
2693   JvmtiEnvIterator it;
2694   for (JvmtiEnv* env = it.first(); env != nullptr; env = it.next(env)) {
2695     if (env->is_enabled(JVMTI_EVENT_GARBAGE_COLLECTION_START)) {
2696       EVT_TRACE(JVMTI_EVENT_GARBAGE_COLLECTION_START,
2697                 ("[%s] garbage collection start event sent",
2698                  JvmtiTrace::safe_get_thread_name(thread)));
2699       JvmtiThreadEventTransition jet(thread);
2700       // JNIEnv is null here because this event is posted from VM Thread
2701       jvmtiEventGarbageCollectionStart callback = env->callbacks()->GarbageCollectionStart;
2702       if (callback != nullptr) {
2703         (*callback)(env->jvmti_external());
2704       }
2705     }
2706   }
2707 }
2708 
2709 void JvmtiExport::post_data_dump() {
2710   Thread *thread = Thread::current();
2711   EVT_TRIG_TRACE(JVMTI_EVENT_DATA_DUMP_REQUEST,
2712                  ("[%s] data dump request event triggered",
2713                   JvmtiTrace::safe_get_thread_name(thread)));
2714   JvmtiEnvIterator it;
2715   for (JvmtiEnv* env = it.first(); env != nullptr; env = it.next(env)) {
2716     if (env->is_enabled(JVMTI_EVENT_DATA_DUMP_REQUEST)) {
2717       EVT_TRACE(JVMTI_EVENT_DATA_DUMP_REQUEST,
2718                 ("[%s] data dump request event sent",
2719                  JvmtiTrace::safe_get_thread_name(thread)));
2720      JvmtiThreadEventTransition jet(thread);
2721      // JNIEnv is null here because this event is posted from VM Thread
2722      jvmtiEventDataDumpRequest callback = env->callbacks()->DataDumpRequest;
2723      if (callback != nullptr) {
2724        (*callback)(env->jvmti_external());
2725      }
2726     }
2727   }
2728 }
2729 
2730 void JvmtiExport::post_monitor_contended_enter(JavaThread *thread, ObjectMonitor *obj_mntr) {
2731   oop object = obj_mntr->object();
2732   HandleMark hm(thread);
2733   Handle h(thread, object);
2734 
2735   JvmtiThreadState *state = get_jvmti_thread_state(thread);
2736   if (state == nullptr) {
2737     return;
2738   }
2739   if (thread->is_in_any_VTMS_transition()) {
2740     return; // no events should be posted if thread is in any VTMS transition
2741   }
2742 
2743   EVT_TRIG_TRACE(JVMTI_EVENT_MONITOR_CONTENDED_ENTER,
2744                      ("[%s] monitor contended enter event triggered",
2745                       JvmtiTrace::safe_get_thread_name(thread)));
2746   JvmtiEnvThreadStateIterator it(state);
2747   for (JvmtiEnvThreadState* ets = it.first(); ets != nullptr; ets = it.next(ets)) {
2748     if (ets->is_enabled(JVMTI_EVENT_MONITOR_CONTENDED_ENTER)) {
2749       EVT_TRACE(JVMTI_EVENT_MONITOR_CONTENDED_ENTER,
2750                    ("[%s] monitor contended enter event sent",
2751                     JvmtiTrace::safe_get_thread_name(thread)));
2752       JvmtiMonitorEventMark  jem(thread, h());
2753       JvmtiEnv *env = ets->get_env();
2754       JvmtiThreadEventTransition jet(thread);
2755       jvmtiEventMonitorContendedEnter callback = env->callbacks()->MonitorContendedEnter;
2756       if (callback != nullptr) {
2757         (*callback)(env->jvmti_external(), jem.jni_env(), jem.jni_thread(), jem.jni_object());
2758       }
2759     }
2760   }
2761 }
2762 
2763 void JvmtiExport::post_monitor_contended_entered(JavaThread *thread, ObjectMonitor *obj_mntr) {
2764   oop object = obj_mntr->object();
2765   HandleMark hm(thread);
2766   Handle h(thread, object);
2767 
2768   JvmtiThreadState *state = get_jvmti_thread_state(thread);
2769   if (state == nullptr) {
2770     return;
2771   }
2772   if (thread->is_in_any_VTMS_transition()) {
2773     return; // no events should be posted if thread is in any VTMS transition
2774   }
2775 
2776   EVT_TRIG_TRACE(JVMTI_EVENT_MONITOR_CONTENDED_ENTERED,
2777                      ("[%s] monitor contended entered event triggered",
2778                       JvmtiTrace::safe_get_thread_name(thread)));
2779 
2780   JvmtiEnvThreadStateIterator it(state);
2781   for (JvmtiEnvThreadState* ets = it.first(); ets != nullptr; ets = it.next(ets)) {
2782     if (ets->is_enabled(JVMTI_EVENT_MONITOR_CONTENDED_ENTERED)) {
2783       EVT_TRACE(JVMTI_EVENT_MONITOR_CONTENDED_ENTERED,
2784                    ("[%s] monitor contended enter event sent",
2785                     JvmtiTrace::safe_get_thread_name(thread)));
2786       JvmtiMonitorEventMark  jem(thread, h());
2787       JvmtiEnv *env = ets->get_env();
2788       JvmtiThreadEventTransition jet(thread);
2789       jvmtiEventMonitorContendedEntered callback = env->callbacks()->MonitorContendedEntered;
2790       if (callback != nullptr) {
2791         (*callback)(env->jvmti_external(), jem.jni_env(), jem.jni_thread(), jem.jni_object());
2792       }
2793     }
2794   }
2795 }
2796 
2797 void JvmtiExport::post_monitor_wait(JavaThread *thread, oop object,
2798                                           jlong timeout) {
2799   HandleMark hm(thread);
2800   Handle h(thread, object);
2801 
2802   JvmtiThreadState *state = get_jvmti_thread_state(thread);
2803   if (state == nullptr) {
2804     return;
2805   }
2806   if (thread->is_in_any_VTMS_transition()) {
2807     return; // no events should be posted if thread is in any VTMS transition
2808   }
2809 
2810   EVT_TRIG_TRACE(JVMTI_EVENT_MONITOR_WAIT,
2811                      ("[%s] monitor wait event triggered",
2812                       JvmtiTrace::safe_get_thread_name(thread)));
2813   JvmtiEnvThreadStateIterator it(state);
2814   for (JvmtiEnvThreadState* ets = it.first(); ets != nullptr; ets = it.next(ets)) {
2815     if (ets->is_enabled(JVMTI_EVENT_MONITOR_WAIT)) {
2816       EVT_TRACE(JVMTI_EVENT_MONITOR_WAIT,
2817                    ("[%s] monitor wait event sent",
2818                     JvmtiTrace::safe_get_thread_name(thread)));
2819       JvmtiMonitorEventMark  jem(thread, h());
2820       JvmtiEnv *env = ets->get_env();
2821       JvmtiThreadEventTransition jet(thread);
2822       jvmtiEventMonitorWait callback = env->callbacks()->MonitorWait;
2823       if (callback != nullptr) {
2824         (*callback)(env->jvmti_external(), jem.jni_env(), jem.jni_thread(),
2825                     jem.jni_object(), timeout);
2826       }
2827     }
2828   }
2829 }
2830 
2831 void JvmtiExport::post_monitor_waited(JavaThread *thread, ObjectMonitor *obj_mntr, jboolean timed_out) {
2832   oop object = obj_mntr->object();
2833   HandleMark hm(thread);
2834   Handle h(thread, object);
2835 
2836   JvmtiThreadState *state = get_jvmti_thread_state(thread);
2837   if (state == nullptr) {
2838     return;
2839   }
2840   if (thread->is_in_any_VTMS_transition()) {
2841     return; // no events should be posted if thread is in any VTMS transition
2842   }
2843 
2844   EVT_TRIG_TRACE(JVMTI_EVENT_MONITOR_WAITED,
2845                      ("[%s] monitor waited event triggered",
2846                       JvmtiTrace::safe_get_thread_name(thread)));
2847   JvmtiEnvThreadStateIterator it(state);
2848   for (JvmtiEnvThreadState* ets = it.first(); ets != nullptr; ets = it.next(ets)) {
2849     if (ets->is_enabled(JVMTI_EVENT_MONITOR_WAITED)) {
2850       EVT_TRACE(JVMTI_EVENT_MONITOR_WAITED,
2851                    ("[%s] monitor waited event sent",
2852                     JvmtiTrace::safe_get_thread_name(thread)));
2853       JvmtiMonitorEventMark  jem(thread, h());
2854       JvmtiEnv *env = ets->get_env();
2855       JvmtiThreadEventTransition jet(thread);
2856       jvmtiEventMonitorWaited callback = env->callbacks()->MonitorWaited;
2857       if (callback != nullptr) {
2858         (*callback)(env->jvmti_external(), jem.jni_env(), jem.jni_thread(),
2859                     jem.jni_object(), timed_out);
2860       }
2861     }
2862   }
2863 }
2864 
2865 void JvmtiExport::post_vm_object_alloc(JavaThread *thread, oop object) {
2866   if (object == nullptr) {
2867     return;
2868   }
2869   if (thread->is_in_any_VTMS_transition()) {
2870     return; // no events should be posted if thread is in any VTMS transition
2871   }
2872   HandleMark hm(thread);
2873   Handle h(thread, object);
2874 
2875   EVT_TRIG_TRACE(JVMTI_EVENT_VM_OBJECT_ALLOC, ("[%s] Trg vm object alloc triggered",
2876                       JvmtiTrace::safe_get_thread_name(thread)));
2877   JvmtiEnvIterator it;
2878   for (JvmtiEnv* env = it.first(); env != nullptr; env = it.next(env)) {
2879     if (env->is_enabled(JVMTI_EVENT_VM_OBJECT_ALLOC)) {
2880       EVT_TRACE(JVMTI_EVENT_VM_OBJECT_ALLOC, ("[%s] Evt vmobject alloc sent %s",
2881                                          JvmtiTrace::safe_get_thread_name(thread),
2882                                          object==nullptr? "null" : object->klass()->external_name()));
2883 
2884       JvmtiObjectAllocEventMark jem(thread, h());
2885       JvmtiJavaThreadEventTransition jet(thread);
2886       jvmtiEventVMObjectAlloc callback = env->callbacks()->VMObjectAlloc;
2887       if (callback != nullptr) {
2888         (*callback)(env->jvmti_external(), jem.jni_env(), jem.jni_thread(),
2889                     jem.jni_jobject(), jem.jni_class(), jem.size());
2890       }
2891     }
2892   }
2893 }
2894 
2895 void JvmtiExport::post_sampled_object_alloc(JavaThread *thread, oop object) {
2896   HandleMark hm(thread);
2897   Handle h(thread, object);
2898 
2899   JvmtiThreadState *state = get_jvmti_thread_state(thread);
2900   if (state == nullptr) {
2901     return;
2902   }
2903   if (object == nullptr) {
2904     return;
2905   }
2906   if (thread->is_in_any_VTMS_transition()) {
2907     return; // no events should be posted if thread is in any VTMS transition
2908   }
2909 
2910   EVT_TRIG_TRACE(JVMTI_EVENT_SAMPLED_OBJECT_ALLOC,
2911                  ("[%s] Trg sampled object alloc triggered",
2912                   JvmtiTrace::safe_get_thread_name(thread)));
2913   JvmtiEnvThreadStateIterator it(state);
2914   for (JvmtiEnvThreadState* ets = it.first(); ets != nullptr; ets = it.next(ets)) {
2915     if (ets->is_enabled(JVMTI_EVENT_SAMPLED_OBJECT_ALLOC)) {
2916       EVT_TRACE(JVMTI_EVENT_SAMPLED_OBJECT_ALLOC,
2917                 ("[%s] Evt sampled object alloc sent %s",
2918                  JvmtiTrace::safe_get_thread_name(thread),
2919                  object == nullptr ? "null" : object->klass()->external_name()));
2920 
2921       JvmtiEnv *env = ets->get_env();
2922       JvmtiObjectAllocEventMark jem(thread, h());
2923       JvmtiJavaThreadEventTransition jet(thread);
2924       jvmtiEventSampledObjectAlloc callback = env->callbacks()->SampledObjectAlloc;
2925       if (callback != nullptr) {
2926         (*callback)(env->jvmti_external(), jem.jni_env(), jem.jni_thread(),
2927                     jem.jni_jobject(), jem.jni_class(), jem.size());
2928       }
2929     }
2930   }
2931 }
2932 
2933 ////////////////////////////////////////////////////////////////////////////////////////////////
2934 
2935 void JvmtiExport::cleanup_thread(JavaThread* thread) {
2936   assert(JavaThread::current() == thread, "thread is not current");
2937   MutexLocker mu(thread, JvmtiThreadState_lock);
2938 
2939   if (thread->jvmti_thread_state() != nullptr) {
2940     // This has to happen after the thread state is removed, which is
2941     // why it is not in post_thread_end_event like its complement
2942     // Maybe both these functions should be rolled into the posts?
2943     JvmtiEventController::thread_ended(thread);
2944   }
2945 }
2946 
2947 void JvmtiExport::clear_detected_exception(JavaThread* thread) {
2948   assert(JavaThread::current() == thread, "thread is not current");
2949 
2950   JvmtiThreadState* state = thread->jvmti_thread_state();
2951   if (state != nullptr) {
2952     state->clear_exception_state();
2953   }
2954 }
2955 
2956 // Onload raw monitor transition.
2957 void JvmtiExport::transition_pending_onload_raw_monitors() {
2958   JvmtiPendingMonitors::transition_raw_monitors();
2959 }
2960 
2961 // Setup current current thread for event collection.
2962 void JvmtiEventCollector::setup_jvmti_thread_state() {
2963   // set this event collector to be the current one.
2964   JvmtiThreadState* state = JvmtiThreadState::state_for(JavaThread::current());
2965   // state can only be null if the current thread is exiting which
2966   // should not happen since we're trying to configure for event collection
2967   guarantee(state != nullptr, "exiting thread called setup_jvmti_thread_state");
2968   if (is_vm_object_alloc_event()) {
2969     JvmtiVMObjectAllocEventCollector *prev = state->get_vm_object_alloc_event_collector();
2970 
2971     // If we have a previous collector and it is disabled, it means this allocation came from a
2972     // callback induced VM Object allocation, do not register this collector then.
2973     if (prev && !prev->is_enabled()) {
2974       return;
2975     }
2976     _prev = prev;
2977     state->set_vm_object_alloc_event_collector((JvmtiVMObjectAllocEventCollector *)this);
2978   } else if (is_dynamic_code_event()) {
2979     _prev = state->get_dynamic_code_event_collector();
2980     state->set_dynamic_code_event_collector((JvmtiDynamicCodeEventCollector *)this);
2981   } else if (is_sampled_object_alloc_event()) {
2982     JvmtiSampledObjectAllocEventCollector *prev = state->get_sampled_object_alloc_event_collector();
2983 
2984     if (prev) {
2985       // JvmtiSampledObjectAllocEventCollector wants only one active collector
2986       // enabled. This allows to have a collector detect a user code requiring
2987       // a sample in the callback.
2988       return;
2989     }
2990     state->set_sampled_object_alloc_event_collector((JvmtiSampledObjectAllocEventCollector*) this);
2991   }
2992 
2993   _unset_jvmti_thread_state = true;
2994 }
2995 
2996 // Unset current event collection in this thread and reset it with previous
2997 // collector.
2998 void JvmtiEventCollector::unset_jvmti_thread_state() {
2999   if (!_unset_jvmti_thread_state) {
3000     return;
3001   }
3002 
3003   JvmtiThreadState* state = JavaThread::current()->jvmti_thread_state();
3004   if (state != nullptr) {
3005     // restore the previous event collector (if any)
3006     if (is_vm_object_alloc_event()) {
3007       if (state->get_vm_object_alloc_event_collector() == this) {
3008         state->set_vm_object_alloc_event_collector((JvmtiVMObjectAllocEventCollector *)_prev);
3009       } else {
3010         // this thread's jvmti state was created during the scope of
3011         // the event collector.
3012       }
3013     } else if (is_dynamic_code_event()) {
3014       if (state->get_dynamic_code_event_collector() == this) {
3015         state->set_dynamic_code_event_collector((JvmtiDynamicCodeEventCollector *)_prev);
3016       } else {
3017         // this thread's jvmti state was created during the scope of
3018         // the event collector.
3019       }
3020     } else if (is_sampled_object_alloc_event()) {
3021       if (state->get_sampled_object_alloc_event_collector() == this) {
3022         state->set_sampled_object_alloc_event_collector((JvmtiSampledObjectAllocEventCollector*)_prev);
3023       } else {
3024         // this thread's jvmti state was created during the scope of
3025         // the event collector.
3026       }
3027     }
3028   }
3029 }
3030 
3031 // create the dynamic code event collector
3032 JvmtiDynamicCodeEventCollector::JvmtiDynamicCodeEventCollector() : _code_blobs(nullptr) {
3033   if (JvmtiExport::should_post_dynamic_code_generated()) {
3034     setup_jvmti_thread_state();
3035   }
3036 }
3037 
3038 // iterate over any code blob descriptors collected and post a
3039 // DYNAMIC_CODE_GENERATED event to the profiler.
3040 JvmtiDynamicCodeEventCollector::~JvmtiDynamicCodeEventCollector() {
3041   assert(!JavaThread::current()->owns_locks(), "all locks must be released to post deferred events");
3042  // iterate over any code blob descriptors that we collected
3043  if (_code_blobs != nullptr) {
3044    for (int i=0; i<_code_blobs->length(); i++) {
3045      JvmtiCodeBlobDesc* blob = _code_blobs->at(i);
3046      JvmtiExport::post_dynamic_code_generated(blob->name(), blob->code_begin(), blob->code_end());
3047      FreeHeap(blob);
3048    }
3049    delete _code_blobs;
3050  }
3051  unset_jvmti_thread_state();
3052 }
3053 
3054 // register a stub
3055 void JvmtiDynamicCodeEventCollector::register_stub(const char* name, address start, address end) {
3056  if (_code_blobs == nullptr) {
3057    _code_blobs = new (mtServiceability) GrowableArray<JvmtiCodeBlobDesc*>(1, mtServiceability);
3058  }
3059  _code_blobs->append(new JvmtiCodeBlobDesc(name, start, end));
3060 }
3061 
3062 // Setup current thread to record vm allocated objects.
3063 JvmtiObjectAllocEventCollector::JvmtiObjectAllocEventCollector() :
3064     _allocated(nullptr), _enable(false), _post_callback(nullptr) {
3065 }
3066 
3067 // Post vm_object_alloc event for vm allocated objects visible to java
3068 // world.
3069 void JvmtiObjectAllocEventCollector::generate_call_for_allocated() {
3070   if (_allocated) {
3071     set_enabled(false);
3072     for (int i = 0; i < _allocated->length(); i++) {
3073       oop obj = _allocated->at(i).resolve();
3074       _post_callback(JavaThread::current(), obj);
3075       // Release OopHandle
3076       _allocated->at(i).release(JvmtiExport::jvmti_oop_storage());
3077 
3078     }
3079     delete _allocated, _allocated = nullptr;
3080   }
3081 }
3082 
3083 void JvmtiObjectAllocEventCollector::record_allocation(oop obj) {
3084   assert(is_enabled(), "Object alloc event collector is not enabled");
3085   if (_allocated == nullptr) {
3086     _allocated = new (mtServiceability) GrowableArray<OopHandle>(1, mtServiceability);
3087   }
3088   _allocated->push(OopHandle(JvmtiExport::jvmti_oop_storage(), obj));
3089 }
3090 
3091 // Disable collection of VMObjectAlloc events
3092 NoJvmtiVMObjectAllocMark::NoJvmtiVMObjectAllocMark() : _collector(nullptr) {
3093   // a no-op if VMObjectAlloc event is not enabled
3094   if (!JvmtiExport::should_post_vm_object_alloc()) {
3095     return;
3096   }
3097   Thread* thread = Thread::current_or_null();
3098   if (thread != nullptr && thread->is_Java_thread())  {
3099     JavaThread* current_thread = JavaThread::cast(thread);
3100     JvmtiThreadState *state = current_thread->jvmti_thread_state();
3101     if (state != nullptr) {
3102       JvmtiVMObjectAllocEventCollector *collector;
3103       collector = state->get_vm_object_alloc_event_collector();
3104       if (collector != nullptr && collector->is_enabled()) {
3105         _collector = collector;
3106         _collector->set_enabled(false);
3107       }
3108     }
3109   }
3110 }
3111 
3112 // Re-Enable collection of VMObjectAlloc events (if previously enabled)
3113 NoJvmtiVMObjectAllocMark::~NoJvmtiVMObjectAllocMark() {
3114   if (was_enabled()) {
3115     _collector->set_enabled(true);
3116   }
3117 };
3118 
3119 // Setup current thread to record vm allocated objects.
3120 JvmtiVMObjectAllocEventCollector::JvmtiVMObjectAllocEventCollector() {
3121   if (JvmtiExport::should_post_vm_object_alloc()) {
3122     _enable = true;
3123     setup_jvmti_thread_state();
3124     _post_callback = JvmtiExport::post_vm_object_alloc;
3125   }
3126 }
3127 
3128 JvmtiVMObjectAllocEventCollector::~JvmtiVMObjectAllocEventCollector() {
3129   if (_enable) {
3130     generate_call_for_allocated();
3131   }
3132   unset_jvmti_thread_state();
3133 }
3134 
3135 bool JvmtiSampledObjectAllocEventCollector::object_alloc_is_safe_to_sample() {
3136   Thread* thread = Thread::current();
3137   // Really only sample allocations if this is a JavaThread and not the compiler
3138   // thread.
3139   if (!thread->is_Java_thread() || thread->is_Compiler_thread()) {
3140     return false;
3141   }
3142 
3143   // If the current thread is attaching from native and its Java thread object
3144   // is being allocated, things are not ready for allocation sampling.
3145   JavaThread* jt = JavaThread::cast(thread);
3146   if (jt->is_attaching_via_jni() && jt->threadObj() == nullptr) {
3147     return false;
3148   }
3149 
3150   return true;
3151 }
3152 
3153 // Setup current thread to record sampled allocated objects.
3154 void JvmtiSampledObjectAllocEventCollector::start() {
3155   if (JvmtiExport::should_post_sampled_object_alloc()) {
3156     if (!object_alloc_is_safe_to_sample()) {
3157       return;
3158     }
3159 
3160     _enable = true;
3161     setup_jvmti_thread_state();
3162     _post_callback = JvmtiExport::post_sampled_object_alloc;
3163   }
3164 }
3165 
3166 JvmtiSampledObjectAllocEventCollector::~JvmtiSampledObjectAllocEventCollector() {
3167   if (!_enable) {
3168     return;
3169   }
3170 
3171   generate_call_for_allocated();
3172   unset_jvmti_thread_state();
3173 
3174   // Unset the sampling collector as present in assertion mode only.
3175   assert(Thread::current()->is_Java_thread(),
3176          "Should always be in a Java thread");
3177 }
3178 
3179 JvmtiGCMarker::JvmtiGCMarker() {
3180   // if there aren't any JVMTI environments then nothing to do
3181   if (!JvmtiEnv::environments_might_exist()) {
3182     return;
3183   }
3184 
3185   if (JvmtiExport::should_post_garbage_collection_start()) {
3186     JvmtiExport::post_garbage_collection_start();
3187   }
3188 
3189   if (SafepointSynchronize::is_at_safepoint()) {
3190     // Do clean up tasks that need to be done at a safepoint
3191     JvmtiEnvBase::check_for_periodic_clean_up();
3192   }
3193 }
3194 
3195 JvmtiGCMarker::~JvmtiGCMarker() {
3196   // if there aren't any JVMTI environments then nothing to do
3197   if (!JvmtiEnv::environments_might_exist()) {
3198     return;
3199   }
3200 
3201   // JVMTI notify gc finish
3202   if (JvmtiExport::should_post_garbage_collection_finish()) {
3203     JvmtiExport::post_garbage_collection_finish();
3204   }
3205 }