1 /*
   2  * Copyright (c) 2003, 2025, 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 "classfile/classLoaderExt.hpp"
  26 #include "classfile/javaClasses.inline.hpp"
  27 #include "classfile/stringTable.hpp"
  28 #include "classfile/modules.hpp"
  29 #include "classfile/systemDictionary.hpp"
  30 #include "classfile/vmClasses.hpp"
  31 #include "classfile/vmSymbols.hpp"
  32 #include "gc/shared/collectedHeap.hpp"
  33 #include "interpreter/bytecodeStream.hpp"
  34 #include "interpreter/interpreter.hpp"
  35 #include "jfr/jfrEvents.hpp"
  36 #include "jvmtifiles/jvmtiEnv.hpp"
  37 #include "logging/log.hpp"
  38 #include "logging/logConfiguration.hpp"
  39 #include "memory/allocation.hpp"
  40 #include "memory/resourceArea.hpp"
  41 #include "memory/universe.hpp"
  42 #include "oops/instanceKlass.hpp"
  43 #include "oops/klass.inline.hpp"
  44 #include "oops/objArrayOop.inline.hpp"
  45 #include "oops/oop.inline.hpp"
  46 #include "prims/jniCheck.hpp"
  47 #include "prims/jvm_misc.hpp"
  48 #include "prims/jvmtiAgentThread.hpp"
  49 #include "prims/jvmtiClassFileReconstituter.hpp"
  50 #include "prims/jvmtiCodeBlobEvents.hpp"
  51 #include "prims/jvmtiExtensions.hpp"
  52 #include "prims/jvmtiGetLoadedClasses.hpp"
  53 #include "prims/jvmtiImpl.hpp"
  54 #include "prims/jvmtiManageCapabilities.hpp"
  55 #include "prims/jvmtiRawMonitor.hpp"
  56 #include "prims/jvmtiRedefineClasses.hpp"
  57 #include "prims/jvmtiTagMap.hpp"
  58 #include "prims/jvmtiThreadState.inline.hpp"
  59 #include "prims/jvmtiUtil.hpp"
  60 #include "runtime/arguments.hpp"
  61 #include "runtime/deoptimization.hpp"
  62 #include "runtime/fieldDescriptor.inline.hpp"
  63 #include "runtime/handles.inline.hpp"
  64 #include "runtime/interfaceSupport.inline.hpp"
  65 #include "runtime/javaCalls.hpp"
  66 #include "runtime/javaThread.inline.hpp"
  67 #include "runtime/jfieldIDWorkaround.hpp"
  68 #include "runtime/jniHandles.inline.hpp"
  69 #include "runtime/objectMonitor.inline.hpp"
  70 #include "runtime/os.hpp"
  71 #include "runtime/osThread.hpp"
  72 #include "runtime/reflectionUtils.hpp"
  73 #include "runtime/signature.hpp"
  74 #include "runtime/threadHeapSampler.hpp"
  75 #include "runtime/threads.hpp"
  76 #include "runtime/threadSMR.hpp"
  77 #include "runtime/timerTrace.hpp"
  78 #include "runtime/vframe.inline.hpp"
  79 #include "runtime/vmThread.hpp"
  80 #include "services/threadService.hpp"
  81 #include "utilities/exceptions.hpp"
  82 #include "utilities/preserveException.hpp"
  83 #include "utilities/utf8.hpp"
  84 
  85 
  86 #define FIXLATER 0 // REMOVE this when completed.
  87 
  88  // FIXLATER: hook into JvmtiTrace
  89 #define TraceJVMTICalls false
  90 
  91 JvmtiEnv::JvmtiEnv(jint version) : JvmtiEnvBase(version) {
  92 }
  93 
  94 JvmtiEnv::~JvmtiEnv() {
  95 }
  96 
  97 JvmtiEnv*
  98 JvmtiEnv::create_a_jvmti(jint version) {
  99   return new JvmtiEnv(version);
 100 }
 101 
 102 // VM operation class to copy jni function table at safepoint.
 103 // More than one java threads or jvmti agents may be reading/
 104 // modifying jni function tables. To reduce the risk of bad
 105 // interaction b/w these threads it is copied at safepoint.
 106 class VM_JNIFunctionTableCopier : public VM_Operation {
 107  private:
 108   const struct JNINativeInterface_ *_function_table;
 109  public:
 110   VM_JNIFunctionTableCopier(const struct JNINativeInterface_ *func_tbl) {
 111     _function_table = func_tbl;
 112   };
 113 
 114   VMOp_Type type() const { return VMOp_JNIFunctionTableCopier; }
 115   void doit() {
 116     copy_jni_function_table(_function_table);
 117   };
 118 };
 119 
 120 //
 121 // Do not change the "prefix" marker below, everything above it is copied
 122 // unchanged into the filled stub, everything below is controlled by the
 123 // stub filler (only method bodies are carried forward, and then only for
 124 // functionality still in the spec).
 125 //
 126 // end file prefix
 127 
 128   //
 129   // Memory Management functions
 130   //
 131 
 132 // mem_ptr - pre-checked for null
 133 jvmtiError
 134 JvmtiEnv::Allocate(jlong size, unsigned char** mem_ptr) {
 135   return allocate(size, mem_ptr);
 136 } /* end Allocate */
 137 
 138 
 139 // mem - null is a valid value, must be checked
 140 jvmtiError
 141 JvmtiEnv::Deallocate(unsigned char* mem) {
 142   return deallocate(mem);
 143 } /* end Deallocate */
 144 
 145 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
 146 // data - null is a valid value, must be checked
 147 jvmtiError
 148 JvmtiEnv::SetThreadLocalStorage(jthread thread, const void* data) {
 149   JavaThread* current = JavaThread::current();
 150   JvmtiThreadState* state = nullptr;
 151   JvmtiVTMSTransitionDisabler disabler(thread);
 152   ThreadsListHandle tlh(current);
 153 
 154   JavaThread* java_thread = nullptr;
 155   oop thread_obj = nullptr;
 156   if (thread == nullptr) {
 157     java_thread = current;
 158     state = java_thread->jvmti_thread_state();
 159   } else {
 160     jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, current, &java_thread, &thread_obj);
 161     if (err != JVMTI_ERROR_NONE) {
 162       return err;
 163     }
 164     state = java_lang_Thread::jvmti_thread_state(thread_obj);
 165   }
 166   if (state == nullptr) {
 167     if (data == nullptr) {
 168       // leaving state unset same as data set to null
 169       return JVMTI_ERROR_NONE;
 170     }
 171     // otherwise, create the state
 172     HandleMark hm(current);
 173     Handle thread_handle(current, thread_obj);
 174     state = JvmtiThreadState::state_for(java_thread, thread_handle);
 175     if (state == nullptr) {
 176       return JVMTI_ERROR_THREAD_NOT_ALIVE;
 177     }
 178   }
 179   state->env_thread_state(this)->set_agent_thread_local_storage_data((void*)data);
 180   return JVMTI_ERROR_NONE;
 181 } /* end SetThreadLocalStorage */
 182 
 183 
 184 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
 185 // data_ptr - pre-checked for null
 186 jvmtiError
 187 JvmtiEnv::GetThreadLocalStorage(jthread thread, void** data_ptr) {
 188   JavaThread* current_thread = JavaThread::current();
 189   if (thread == nullptr) {
 190     JvmtiThreadState* state = current_thread->jvmti_thread_state();
 191     *data_ptr = (state == nullptr) ? nullptr :
 192       state->env_thread_state(this)->get_agent_thread_local_storage_data();
 193   } else {
 194     // jvmti_GetThreadLocalStorage is "in native" and doesn't transition
 195     // the thread to _thread_in_vm. However, when the TLS for a thread
 196     // other than the current thread is required we need to transition
 197     // from native so as to resolve the jthread.
 198 
 199     MACOS_AARCH64_ONLY(ThreadWXEnable __wx(WXWrite, current_thread));
 200     ThreadInVMfromNative __tiv(current_thread);
 201     VM_ENTRY_BASE(jvmtiError, JvmtiEnv::GetThreadLocalStorage , current_thread)
 202     debug_only(VMNativeEntryWrapper __vew;)
 203 
 204     JvmtiVTMSTransitionDisabler disabler(thread);
 205     ThreadsListHandle tlh(current_thread);
 206 
 207     JavaThread* java_thread = nullptr;
 208     oop thread_obj = nullptr;
 209     jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, current_thread, &java_thread, &thread_obj);
 210     if (err != JVMTI_ERROR_NONE) {
 211       return err;
 212     }
 213 
 214     HandleMark hm(current_thread);
 215     Handle thread_handle(current_thread, thread_obj);
 216     JvmtiThreadState* state = JvmtiThreadState::state_for(java_thread, thread_handle);
 217     *data_ptr = (state == nullptr) ? nullptr :
 218       state->env_thread_state(this)->get_agent_thread_local_storage_data();
 219   }
 220   return JVMTI_ERROR_NONE;
 221 } /* end GetThreadLocalStorage */
 222 
 223   //
 224   // Module functions
 225   //
 226 
 227 // module_count_ptr - pre-checked for null
 228 // modules_ptr - pre-checked for null
 229 jvmtiError
 230 JvmtiEnv::GetAllModules(jint* module_count_ptr, jobject** modules_ptr) {
 231     JvmtiModuleClosure jmc;
 232 
 233     return jmc.get_all_modules(this, module_count_ptr, modules_ptr);
 234 } /* end GetAllModules */
 235 
 236 
 237 // class_loader - null is a valid value, must be pre-checked
 238 // package_name - pre-checked for null
 239 // module_ptr - pre-checked for null
 240 jvmtiError
 241 JvmtiEnv::GetNamedModule(jobject class_loader, const char* package_name, jobject* module_ptr) {
 242   JavaThread* THREAD = JavaThread::current(); // For exception macros.
 243   ResourceMark rm(THREAD);
 244 
 245   Handle h_loader (THREAD, JNIHandles::resolve(class_loader));
 246   // Check that loader is a subclass of java.lang.ClassLoader.
 247   if (h_loader.not_null() && !java_lang_ClassLoader::is_subclass(h_loader->klass())) {
 248     return JVMTI_ERROR_ILLEGAL_ARGUMENT;
 249   }
 250   oop module = Modules::get_named_module(h_loader, package_name);
 251   *module_ptr = module != nullptr ? JNIHandles::make_local(THREAD, module) : nullptr;
 252   return JVMTI_ERROR_NONE;
 253 } /* end GetNamedModule */
 254 
 255 
 256 // module - pre-checked for null
 257 // to_module - pre-checked for null
 258 jvmtiError
 259 JvmtiEnv::AddModuleReads(jobject module, jobject to_module) {
 260   JavaThread* THREAD = JavaThread::current(); // For exception macros.
 261 
 262   // check module
 263   Handle h_module(THREAD, JNIHandles::resolve(module));
 264   if (!java_lang_Module::is_instance(h_module())) {
 265     return JVMTI_ERROR_INVALID_MODULE;
 266   }
 267   // check to_module
 268   Handle h_to_module(THREAD, JNIHandles::resolve(to_module));
 269   if (!java_lang_Module::is_instance(h_to_module())) {
 270     return JVMTI_ERROR_INVALID_MODULE;
 271   }
 272   return JvmtiExport::add_module_reads(h_module, h_to_module, THREAD);
 273 } /* end AddModuleReads */
 274 
 275 
 276 // module - pre-checked for null
 277 // pkg_name - pre-checked for null
 278 // to_module - pre-checked for null
 279 jvmtiError
 280 JvmtiEnv::AddModuleExports(jobject module, const char* pkg_name, jobject to_module) {
 281   JavaThread* THREAD = JavaThread::current(); // For exception macros.
 282   Handle h_pkg = java_lang_String::create_from_str(pkg_name, THREAD);
 283 
 284   // check module
 285   Handle h_module(THREAD, JNIHandles::resolve(module));
 286   if (!java_lang_Module::is_instance(h_module())) {
 287     return JVMTI_ERROR_INVALID_MODULE;
 288   }
 289   // check to_module
 290   Handle h_to_module(THREAD, JNIHandles::resolve(to_module));
 291   if (!java_lang_Module::is_instance(h_to_module())) {
 292     return JVMTI_ERROR_INVALID_MODULE;
 293   }
 294   return JvmtiExport::add_module_exports(h_module, h_pkg, h_to_module, THREAD);
 295 } /* end AddModuleExports */
 296 
 297 
 298 // module - pre-checked for null
 299 // pkg_name - pre-checked for null
 300 // to_module - pre-checked for null
 301 jvmtiError
 302 JvmtiEnv::AddModuleOpens(jobject module, const char* pkg_name, jobject to_module) {
 303   JavaThread* THREAD = JavaThread::current(); // For exception macros.
 304   Handle h_pkg = java_lang_String::create_from_str(pkg_name, THREAD);
 305 
 306   // check module
 307   Handle h_module(THREAD, JNIHandles::resolve(module));
 308   if (!java_lang_Module::is_instance(h_module())) {
 309     return JVMTI_ERROR_INVALID_MODULE;
 310   }
 311   // check to_module
 312   Handle h_to_module(THREAD, JNIHandles::resolve(to_module));
 313   if (!java_lang_Module::is_instance(h_to_module())) {
 314     return JVMTI_ERROR_INVALID_MODULE;
 315   }
 316   return JvmtiExport::add_module_opens(h_module, h_pkg, h_to_module, THREAD);
 317 } /* end AddModuleOpens */
 318 
 319 
 320 // module - pre-checked for null
 321 // service - pre-checked for null
 322 jvmtiError
 323 JvmtiEnv::AddModuleUses(jobject module, jclass service) {
 324   JavaThread* THREAD = JavaThread::current(); // For exception macros.
 325 
 326   // check module
 327   Handle h_module(THREAD, JNIHandles::resolve(module));
 328   if (!java_lang_Module::is_instance(h_module())) {
 329     return JVMTI_ERROR_INVALID_MODULE;
 330   }
 331   // check service
 332   Handle h_service(THREAD, JNIHandles::resolve_external_guard(service));
 333   if (!java_lang_Class::is_instance(h_service()) ||
 334       java_lang_Class::is_primitive(h_service())) {
 335     return JVMTI_ERROR_INVALID_CLASS;
 336   }
 337   return JvmtiExport::add_module_uses(h_module, h_service, THREAD);
 338 } /* end AddModuleUses */
 339 
 340 
 341 // module - pre-checked for null
 342 // service - pre-checked for null
 343 // impl_class - pre-checked for null
 344 jvmtiError
 345 JvmtiEnv::AddModuleProvides(jobject module, jclass service, jclass impl_class) {
 346   JavaThread* THREAD = JavaThread::current(); // For exception macros.
 347 
 348   // check module
 349   Handle h_module(THREAD, JNIHandles::resolve(module));
 350   if (!java_lang_Module::is_instance(h_module())) {
 351     return JVMTI_ERROR_INVALID_MODULE;
 352   }
 353   // check service
 354   Handle h_service(THREAD, JNIHandles::resolve_external_guard(service));
 355   if (!java_lang_Class::is_instance(h_service()) ||
 356       java_lang_Class::is_primitive(h_service())) {
 357     return JVMTI_ERROR_INVALID_CLASS;
 358   }
 359   // check impl_class
 360   Handle h_impl_class(THREAD, JNIHandles::resolve_external_guard(impl_class));
 361   if (!java_lang_Class::is_instance(h_impl_class()) ||
 362       java_lang_Class::is_primitive(h_impl_class())) {
 363     return JVMTI_ERROR_INVALID_CLASS;
 364   }
 365   return JvmtiExport::add_module_provides(h_module, h_service, h_impl_class, THREAD);
 366 } /* end AddModuleProvides */
 367 
 368 // module - pre-checked for null
 369 // is_modifiable_class_ptr - pre-checked for null
 370 jvmtiError
 371 JvmtiEnv::IsModifiableModule(jobject module, jboolean* is_modifiable_module_ptr) {
 372   JavaThread* current = JavaThread::current();
 373 
 374   // check module
 375   Handle h_module(current, JNIHandles::resolve(module));
 376   if (!java_lang_Module::is_instance(h_module())) {
 377     return JVMTI_ERROR_INVALID_MODULE;
 378   }
 379 
 380   *is_modifiable_module_ptr = JNI_TRUE;
 381   return JVMTI_ERROR_NONE;
 382 } /* end IsModifiableModule */
 383 
 384 
 385   //
 386   // Class functions
 387   //
 388 
 389 // class_count_ptr - pre-checked for null
 390 // classes_ptr - pre-checked for null
 391 jvmtiError
 392 JvmtiEnv::GetLoadedClasses(jint* class_count_ptr, jclass** classes_ptr) {
 393   return JvmtiGetLoadedClasses::getLoadedClasses(this, class_count_ptr, classes_ptr);
 394 } /* end GetLoadedClasses */
 395 
 396 
 397 // initiating_loader - null is a valid value, must be checked
 398 // class_count_ptr - pre-checked for null
 399 // classes_ptr - pre-checked for null
 400 jvmtiError
 401 JvmtiEnv::GetClassLoaderClasses(jobject initiating_loader, jint* class_count_ptr, jclass** classes_ptr) {
 402   return JvmtiGetLoadedClasses::getClassLoaderClasses(this, initiating_loader,
 403                                                   class_count_ptr, classes_ptr);
 404 } /* end GetClassLoaderClasses */
 405 
 406 // k_mirror - may be primitive, this must be checked
 407 // is_modifiable_class_ptr - pre-checked for null
 408 jvmtiError
 409 JvmtiEnv::IsModifiableClass(oop k_mirror, jboolean* is_modifiable_class_ptr) {
 410   *is_modifiable_class_ptr = VM_RedefineClasses::is_modifiable_class(k_mirror)?
 411                                                        JNI_TRUE : JNI_FALSE;
 412   return JVMTI_ERROR_NONE;
 413 } /* end IsModifiableClass */
 414 
 415 // class_count - pre-checked to be greater than or equal to 0
 416 // classes - pre-checked for null
 417 jvmtiError
 418 JvmtiEnv::RetransformClasses(jint class_count, const jclass* classes) {
 419 //TODO: add locking
 420 
 421   int index;
 422   JavaThread* current_thread = JavaThread::current();
 423   ResourceMark rm(current_thread);
 424 
 425   jvmtiClassDefinition* class_definitions =
 426                             NEW_RESOURCE_ARRAY(jvmtiClassDefinition, class_count);
 427   NULL_CHECK(class_definitions, JVMTI_ERROR_OUT_OF_MEMORY);
 428 
 429   for (index = 0; index < class_count; index++) {
 430     HandleMark hm(current_thread);
 431 
 432     jclass jcls = classes[index];
 433     oop k_mirror = JNIHandles::resolve_external_guard(jcls);
 434     if (k_mirror == nullptr) {
 435       return JVMTI_ERROR_INVALID_CLASS;
 436     }
 437     if (!k_mirror->is_a(vmClasses::Class_klass())) {
 438       return JVMTI_ERROR_INVALID_CLASS;
 439     }
 440 
 441     if (!VM_RedefineClasses::is_modifiable_class(k_mirror)) {
 442       return JVMTI_ERROR_UNMODIFIABLE_CLASS;
 443     }
 444 
 445     Klass* klass = java_lang_Class::as_Klass(k_mirror);
 446 
 447     jint status = klass->jvmti_class_status();
 448     if (status & (JVMTI_CLASS_STATUS_ERROR)) {
 449       return JVMTI_ERROR_INVALID_CLASS;
 450     }
 451 
 452     InstanceKlass* ik = InstanceKlass::cast(klass);
 453     if (ik->get_cached_class_file_bytes() == nullptr) {
 454       // Not cached, we need to reconstitute the class file from the
 455       // VM representation. We don't attach the reconstituted class
 456       // bytes to the InstanceKlass here because they have not been
 457       // validated and we're not at a safepoint.
 458       JvmtiClassFileReconstituter reconstituter(ik);
 459       if (reconstituter.get_error() != JVMTI_ERROR_NONE) {
 460         return reconstituter.get_error();
 461       }
 462 
 463       class_definitions[index].class_byte_count = (jint)reconstituter.class_file_size();
 464       class_definitions[index].class_bytes      = (unsigned char*)
 465                                                        reconstituter.class_file_bytes();
 466     } else {
 467       // it is cached, get it from the cache
 468       class_definitions[index].class_byte_count = ik->get_cached_class_file_len();
 469       class_definitions[index].class_bytes      = ik->get_cached_class_file_bytes();
 470     }
 471     class_definitions[index].klass              = jcls;
 472   }
 473   EventRetransformClasses event;
 474   VM_RedefineClasses op(class_count, class_definitions, jvmti_class_load_kind_retransform);
 475   VMThread::execute(&op);
 476   jvmtiError error = op.check_error();
 477   if (error == JVMTI_ERROR_NONE) {
 478     event.set_classCount(class_count);
 479     event.set_redefinitionId(op.id());
 480     event.commit();
 481   }
 482   return error;
 483 } /* end RetransformClasses */
 484 
 485 
 486 // class_count - pre-checked to be greater than or equal to 0
 487 // class_definitions - pre-checked for null
 488 jvmtiError
 489 JvmtiEnv::RedefineClasses(jint class_count, const jvmtiClassDefinition* class_definitions) {
 490 //TODO: add locking
 491   EventRedefineClasses event;
 492   VM_RedefineClasses op(class_count, class_definitions, jvmti_class_load_kind_redefine);
 493   VMThread::execute(&op);
 494   jvmtiError error = op.check_error();
 495   if (error == JVMTI_ERROR_NONE) {
 496     event.set_classCount(class_count);
 497     event.set_redefinitionId(op.id());
 498     event.commit();
 499   }
 500   return error;
 501 } /* end RedefineClasses */
 502 
 503 
 504   //
 505   // Object functions
 506   //
 507 
 508 // size_ptr - pre-checked for null
 509 jvmtiError
 510 JvmtiEnv::GetObjectSize(jobject object, jlong* size_ptr) {
 511   oop mirror = JNIHandles::resolve_external_guard(object);
 512   NULL_CHECK(mirror, JVMTI_ERROR_INVALID_OBJECT);
 513   *size_ptr = (jlong)mirror->size() * wordSize;
 514   return JVMTI_ERROR_NONE;
 515 } /* end GetObjectSize */
 516 
 517   //
 518   // Method functions
 519   //
 520 
 521 // prefix - null is a valid value, must be checked
 522 jvmtiError
 523 JvmtiEnv::SetNativeMethodPrefix(const char* prefix) {
 524   return prefix == nullptr?
 525               SetNativeMethodPrefixes(0, nullptr) :
 526               SetNativeMethodPrefixes(1, (char**)&prefix);
 527 } /* end SetNativeMethodPrefix */
 528 
 529 
 530 // prefix_count - pre-checked to be greater than or equal to 0
 531 // prefixes - pre-checked for null
 532 jvmtiError
 533 JvmtiEnv::SetNativeMethodPrefixes(jint prefix_count, char** prefixes) {
 534   // Have to grab JVMTI thread state lock to be sure that some thread
 535   // isn't accessing the prefixes at the same time we are setting them.
 536   // No locks during VM bring-up.
 537   if (Threads::number_of_threads() == 0) {
 538     return set_native_method_prefixes(prefix_count, prefixes);
 539   } else {
 540     MutexLocker mu(JvmtiThreadState_lock);
 541     return set_native_method_prefixes(prefix_count, prefixes);
 542   }
 543 } /* end SetNativeMethodPrefixes */
 544 
 545   //
 546   // Event Management functions
 547   //
 548 
 549 // callbacks - null is a valid value, must be checked
 550 // size_of_callbacks - pre-checked to be greater than or equal to 0
 551 jvmtiError
 552 JvmtiEnv::SetEventCallbacks(const jvmtiEventCallbacks* callbacks, jint size_of_callbacks) {
 553   JvmtiVTMSTransitionDisabler disabler;
 554   JvmtiEventController::set_event_callbacks(this, callbacks, size_of_callbacks);
 555   return JVMTI_ERROR_NONE;
 556 } /* end SetEventCallbacks */
 557 
 558 
 559 // event_thread - null is a valid value, must be checked
 560 jvmtiError
 561 JvmtiEnv::SetEventNotificationMode(jvmtiEventMode mode, jvmtiEvent event_type, jthread event_thread,   ...) {
 562   bool enabled = (mode == JVMTI_ENABLE);
 563 
 564   // event_type must be valid
 565   if (!JvmtiEventController::is_valid_event_type(event_type)) {
 566     return JVMTI_ERROR_INVALID_EVENT_TYPE;
 567   }
 568 
 569   // assure that needed capabilities are present
 570   if (enabled && !JvmtiUtil::has_event_capability(event_type, get_capabilities())) {
 571     return JVMTI_ERROR_MUST_POSSESS_CAPABILITY;
 572   }
 573 
 574   if (event_type == JVMTI_EVENT_CLASS_FILE_LOAD_HOOK && enabled) {
 575     record_class_file_load_hook_enabled();
 576   }
 577   JvmtiVTMSTransitionDisabler disabler;
 578 
 579   if (event_thread == nullptr) {
 580     // Can be called at Agent_OnLoad() time with event_thread == nullptr
 581     // when Thread::current() does not work yet so we cannot create a
 582     // ThreadsListHandle that is common to both thread-specific and
 583     // global code paths.
 584 
 585     JvmtiEventController::set_user_enabled(this, nullptr, (oop) nullptr, event_type, enabled);
 586   } else {
 587     // We have a specified event_thread.
 588     JavaThread* current = JavaThread::current();
 589     ThreadsListHandle tlh(current);
 590 
 591     JavaThread* java_thread = nullptr;
 592     oop thread_obj = nullptr;
 593     jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), event_thread, current, &java_thread, &thread_obj);
 594     if (err != JVMTI_ERROR_NONE) {
 595       return err;
 596     }
 597 
 598     // global events cannot be controlled at thread level.
 599     if (JvmtiEventController::is_global_event(event_type)) {
 600       return JVMTI_ERROR_ILLEGAL_ARGUMENT;
 601     }
 602 
 603     JvmtiEventController::set_user_enabled(this, java_thread, thread_obj, event_type, enabled);
 604   }
 605 
 606   return JVMTI_ERROR_NONE;
 607 } /* end SetEventNotificationMode */
 608 
 609   //
 610   // Capability functions
 611   //
 612 
 613 // capabilities_ptr - pre-checked for null
 614 jvmtiError
 615 JvmtiEnv::GetPotentialCapabilities(jvmtiCapabilities* capabilities_ptr) {
 616   JvmtiManageCapabilities::get_potential_capabilities(get_capabilities(),
 617                                                       get_prohibited_capabilities(),
 618                                                       capabilities_ptr);
 619   return JVMTI_ERROR_NONE;
 620 } /* end GetPotentialCapabilities */
 621 
 622 
 623 // capabilities_ptr - pre-checked for null
 624 jvmtiError
 625 JvmtiEnv::AddCapabilities(const jvmtiCapabilities* capabilities_ptr) {
 626   return JvmtiManageCapabilities::add_capabilities(get_capabilities(),
 627                                                    get_prohibited_capabilities(),
 628                                                    capabilities_ptr,
 629                                                    get_capabilities());
 630 } /* end AddCapabilities */
 631 
 632 
 633 // capabilities_ptr - pre-checked for null
 634 jvmtiError
 635 JvmtiEnv::RelinquishCapabilities(const jvmtiCapabilities* capabilities_ptr) {
 636   JvmtiManageCapabilities::relinquish_capabilities(get_capabilities(), capabilities_ptr, get_capabilities());
 637   return JVMTI_ERROR_NONE;
 638 } /* end RelinquishCapabilities */
 639 
 640 
 641 // capabilities_ptr - pre-checked for null
 642 jvmtiError
 643 JvmtiEnv::GetCapabilities(jvmtiCapabilities* capabilities_ptr) {
 644   JvmtiManageCapabilities::copy_capabilities(get_capabilities(), capabilities_ptr);
 645   return JVMTI_ERROR_NONE;
 646 } /* end GetCapabilities */
 647 
 648   //
 649   // Class Loader Search functions
 650   //
 651 
 652 // segment - pre-checked for null
 653 jvmtiError
 654 JvmtiEnv::AddToBootstrapClassLoaderSearch(const char* segment) {
 655   jvmtiPhase phase = get_phase();
 656   if (phase == JVMTI_PHASE_ONLOAD) {
 657     Arguments::append_sysclasspath(segment);
 658     return JVMTI_ERROR_NONE;
 659   } else if (use_version_1_0_semantics()) {
 660     // This JvmtiEnv requested version 1.0 semantics and this function
 661     // is only allowed in the ONLOAD phase in version 1.0 so we need to
 662     // return an error here.
 663     return JVMTI_ERROR_WRONG_PHASE;
 664   } else if (phase == JVMTI_PHASE_LIVE) {
 665     // The phase is checked by the wrapper that called this function,
 666     // but this thread could be racing with the thread that is
 667     // terminating the VM so we check one more time.
 668 
 669     // create the zip entry
 670     ClassPathZipEntry* zip_entry = ClassLoader::create_class_path_zip_entry(segment);
 671     if (zip_entry == nullptr) {
 672       return JVMTI_ERROR_ILLEGAL_ARGUMENT;
 673     }
 674 
 675     // add the jar file to the bootclasspath
 676     log_info(class, load)("opened: %s", zip_entry->name());
 677 #if INCLUDE_CDS
 678     ClassLoaderExt::append_boot_classpath(zip_entry);
 679 #else
 680     ClassLoader::add_to_boot_append_entries(zip_entry);
 681 #endif
 682     return JVMTI_ERROR_NONE;
 683   } else {
 684     return JVMTI_ERROR_WRONG_PHASE;
 685   }
 686 
 687 } /* end AddToBootstrapClassLoaderSearch */
 688 
 689 
 690 // segment - pre-checked for null
 691 jvmtiError
 692 JvmtiEnv::AddToSystemClassLoaderSearch(const char* segment) {
 693   jvmtiPhase phase = get_phase();
 694 
 695   if (phase == JVMTI_PHASE_ONLOAD) {
 696     for (SystemProperty* p = Arguments::system_properties(); p != nullptr; p = p->next()) {
 697       if (strcmp("java.class.path", p->key()) == 0) {
 698         p->append_value(segment);
 699         break;
 700       }
 701     }
 702     return JVMTI_ERROR_NONE;
 703   } else if (phase == JVMTI_PHASE_LIVE) {
 704     // The phase is checked by the wrapper that called this function,
 705     // but this thread could be racing with the thread that is
 706     // terminating the VM so we check one more time.
 707     JavaThread* THREAD = JavaThread::current(); // For exception macros.
 708     HandleMark hm(THREAD);
 709 
 710     // create the zip entry (which will open the zip file and hence
 711     // check that the segment is indeed a zip file).
 712     ClassPathZipEntry* zip_entry = ClassLoader::create_class_path_zip_entry(segment);
 713     if (zip_entry == nullptr) {
 714       return JVMTI_ERROR_ILLEGAL_ARGUMENT;
 715     }
 716     delete zip_entry;   // no longer needed
 717 
 718     Handle loader(THREAD, SystemDictionary::java_system_loader());
 719 
 720     // need the path as java.lang.String
 721     Handle path = java_lang_String::create_from_platform_dependent_str(segment, THREAD);
 722     if (HAS_PENDING_EXCEPTION) {
 723       CLEAR_PENDING_EXCEPTION;
 724       return JVMTI_ERROR_INTERNAL;
 725     }
 726 
 727     // Invoke the appendToClassPathForInstrumentation method - if the method
 728     // is not found it means the loader doesn't support adding to the class path
 729     // in the live phase.
 730     {
 731       JavaValue res(T_VOID);
 732       JavaCalls::call_special(&res,
 733                               loader,
 734                               loader->klass(),
 735                               vmSymbols::appendToClassPathForInstrumentation_name(),
 736                               vmSymbols::appendToClassPathForInstrumentation_signature(),
 737                               path,
 738                               THREAD);
 739       if (HAS_PENDING_EXCEPTION) {
 740         Symbol* ex_name = PENDING_EXCEPTION->klass()->name();
 741         CLEAR_PENDING_EXCEPTION;
 742 
 743         if (ex_name == vmSymbols::java_lang_NoSuchMethodError()) {
 744           return JVMTI_ERROR_CLASS_LOADER_UNSUPPORTED;
 745         } else {
 746           return JVMTI_ERROR_INTERNAL;
 747         }
 748       }
 749     }
 750 
 751     return JVMTI_ERROR_NONE;
 752   } else {
 753     return JVMTI_ERROR_WRONG_PHASE;
 754   }
 755 } /* end AddToSystemClassLoaderSearch */
 756 
 757   //
 758   // General functions
 759   //
 760 
 761 // phase_ptr - pre-checked for null
 762 jvmtiError
 763 JvmtiEnv::GetPhase(jvmtiPhase* phase_ptr) {
 764   *phase_ptr = phase();
 765   return JVMTI_ERROR_NONE;
 766 } /* end GetPhase */
 767 
 768 
 769 jvmtiError
 770 JvmtiEnv::DisposeEnvironment() {
 771   dispose();
 772   return JVMTI_ERROR_NONE;
 773 } /* end DisposeEnvironment */
 774 
 775 
 776 // data - null is a valid value, must be checked
 777 jvmtiError
 778 JvmtiEnv::SetEnvironmentLocalStorage(const void* data) {
 779   set_env_local_storage(data);
 780   return JVMTI_ERROR_NONE;
 781 } /* end SetEnvironmentLocalStorage */
 782 
 783 
 784 // data_ptr - pre-checked for null
 785 jvmtiError
 786 JvmtiEnv::GetEnvironmentLocalStorage(void** data_ptr) {
 787   *data_ptr = (void*)get_env_local_storage();
 788   return JVMTI_ERROR_NONE;
 789 } /* end GetEnvironmentLocalStorage */
 790 
 791 // version_ptr - pre-checked for null
 792 jvmtiError
 793 JvmtiEnv::GetVersionNumber(jint* version_ptr) {
 794   *version_ptr = JVMTI_VERSION;
 795   return JVMTI_ERROR_NONE;
 796 } /* end GetVersionNumber */
 797 
 798 
 799 // name_ptr - pre-checked for null
 800 jvmtiError
 801 JvmtiEnv::GetErrorName(jvmtiError error, char** name_ptr) {
 802   if (error < JVMTI_ERROR_NONE || error > JVMTI_ERROR_MAX) {
 803     return JVMTI_ERROR_ILLEGAL_ARGUMENT;
 804   }
 805   const char *name = JvmtiUtil::error_name(error);
 806   if (name == nullptr) {
 807     return JVMTI_ERROR_ILLEGAL_ARGUMENT;
 808   }
 809   size_t len = strlen(name) + 1;
 810   jvmtiError err = allocate(len, (unsigned char**)name_ptr);
 811   if (err == JVMTI_ERROR_NONE) {
 812     memcpy(*name_ptr, name, len);
 813   }
 814   return err;
 815 } /* end GetErrorName */
 816 
 817 
 818 jvmtiError
 819 JvmtiEnv::SetVerboseFlag(jvmtiVerboseFlag flag, jboolean value) {
 820   LogLevelType level = value == 0 ? LogLevel::Off : LogLevel::Info;
 821   switch (flag) {
 822   case JVMTI_VERBOSE_OTHER:
 823     // ignore
 824     break;
 825   case JVMTI_VERBOSE_CLASS:
 826     LogConfiguration::configure_stdout(level, false, LOG_TAGS(class, unload));
 827     LogConfiguration::configure_stdout(level, false, LOG_TAGS(class, load));
 828     break;
 829   case JVMTI_VERBOSE_GC:
 830     LogConfiguration::configure_stdout(level, true, LOG_TAGS(gc));
 831     break;
 832   case JVMTI_VERBOSE_JNI:
 833     level = value == 0 ? LogLevel::Off : LogLevel::Debug;
 834     LogConfiguration::configure_stdout(level, true, LOG_TAGS(jni, resolve));
 835     break;
 836   default:
 837     return JVMTI_ERROR_ILLEGAL_ARGUMENT;
 838   };
 839   return JVMTI_ERROR_NONE;
 840 } /* end SetVerboseFlag */
 841 
 842 
 843 // format_ptr - pre-checked for null
 844 jvmtiError
 845 JvmtiEnv::GetJLocationFormat(jvmtiJlocationFormat* format_ptr) {
 846   *format_ptr = JVMTI_JLOCATION_JVMBCI;
 847   return JVMTI_ERROR_NONE;
 848 } /* end GetJLocationFormat */
 849 
 850   //
 851   // Thread functions
 852   //
 853 
 854 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
 855 // thread_state_ptr - pre-checked for null
 856 jvmtiError
 857 JvmtiEnv::GetThreadState(jthread thread, jint* thread_state_ptr) {
 858   JavaThread* current_thread = JavaThread::current();
 859   JvmtiVTMSTransitionDisabler disabler(thread);
 860   ThreadsListHandle tlh(current_thread);
 861 
 862   JavaThread* java_thread = nullptr;
 863   oop thread_oop = nullptr;
 864   jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, current_thread, &java_thread, &thread_oop);
 865   if (err != JVMTI_ERROR_NONE && err != JVMTI_ERROR_THREAD_NOT_ALIVE) {
 866     // We got an error code so we don't have a JavaThread*, but only
 867     // return an error from here if the error is not because the thread
 868     // is a virtual thread.
 869     return err;
 870   }
 871   *thread_state_ptr = JvmtiEnvBase::get_thread_or_vthread_state(thread_oop, java_thread);
 872   return JVMTI_ERROR_NONE;
 873 } /* end GetThreadState */
 874 
 875 
 876 // thread_ptr - pre-checked for null
 877 jvmtiError
 878 JvmtiEnv::GetCurrentThread(jthread* thread_ptr) {
 879   JavaThread* cur_thread = JavaThread::current();
 880   oop thread_oop = get_vthread_or_thread_oop(cur_thread);
 881 
 882   *thread_ptr = (jthread)JNIHandles::make_local(cur_thread, thread_oop);
 883   return JVMTI_ERROR_NONE;
 884 } /* end GetCurrentThread */
 885 
 886 
 887 // threads_count_ptr - pre-checked for null
 888 // threads_ptr - pre-checked for null
 889 jvmtiError
 890 JvmtiEnv::GetAllThreads(jint* threads_count_ptr, jthread** threads_ptr) {
 891   int nthreads        = 0;
 892   Handle *thread_objs = nullptr;
 893   Thread* current_thread = Thread::current();
 894   ResourceMark rm(current_thread);
 895   HandleMark hm(current_thread);
 896 
 897   // enumerate threads (including agent threads)
 898   ThreadsListEnumerator tle(current_thread, true);
 899   nthreads = tle.num_threads();
 900   *threads_count_ptr = nthreads;
 901 
 902   if (nthreads == 0) {
 903     *threads_ptr = nullptr;
 904     return JVMTI_ERROR_NONE;
 905   }
 906 
 907   thread_objs = NEW_RESOURCE_ARRAY(Handle, nthreads);
 908   NULL_CHECK(thread_objs, JVMTI_ERROR_OUT_OF_MEMORY);
 909 
 910   for (int i = 0; i < nthreads; i++) {
 911     thread_objs[i] = Handle(tle.get_threadObj(i));
 912   }
 913 
 914   jthread *jthreads  = new_jthreadArray(nthreads, thread_objs);
 915   NULL_CHECK(jthreads, JVMTI_ERROR_OUT_OF_MEMORY);
 916 
 917   *threads_ptr = jthreads;
 918   return JVMTI_ERROR_NONE;
 919 } /* end GetAllThreads */
 920 
 921 
 922 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
 923 jvmtiError
 924 JvmtiEnv::SuspendThread(jthread thread) {
 925   JavaThread* current = JavaThread::current();
 926   HandleMark hm(current);
 927   Handle self_tobj;
 928 
 929   jvmtiError err;
 930   {
 931     JvmtiVTMSTransitionDisabler disabler(true);
 932     ThreadsListHandle tlh(current);
 933     JavaThread* java_thread = nullptr;
 934     oop thread_oop = nullptr;
 935 
 936     err = get_threadOop_and_JavaThread(tlh.list(), thread, current, &java_thread, &thread_oop);
 937     if (err != JVMTI_ERROR_NONE) {
 938       return err;
 939     }
 940 
 941     // Do not use JvmtiVTMSTransitionDisabler in context of self suspend to avoid deadlocks.
 942     if (java_thread != current) {
 943       err = suspend_thread(thread_oop, java_thread, /* single_suspend */ true);
 944       return err;
 945     }
 946     // protect thread_oop as a safepoint can be reached in disabler destructor
 947     self_tobj = Handle(current, thread_oop);
 948   }
 949   // Do self suspend for current JavaThread.
 950   err = suspend_thread(self_tobj(), current, /* single_suspend */ true);
 951   return err;
 952 } /* end SuspendThread */
 953 
 954 
 955 // request_count - pre-checked to be greater than or equal to 0
 956 // request_list - pre-checked for null
 957 // results - pre-checked for null
 958 jvmtiError
 959 JvmtiEnv::SuspendThreadList(jint request_count, const jthread* request_list, jvmtiError* results) {
 960   JavaThread* current = JavaThread::current();
 961   HandleMark hm(current);
 962   Handle self_tobj;
 963   int self_idx = -1;
 964 
 965   {
 966     JvmtiVTMSTransitionDisabler disabler(true);
 967     ThreadsListHandle tlh(current);
 968 
 969     for (int i = 0; i < request_count; i++) {
 970       JavaThread *java_thread = nullptr;
 971       oop thread_oop = nullptr;
 972       jthread thread = request_list[i];
 973       jvmtiError err = JvmtiExport::cv_external_thread_to_JavaThread(tlh.list(), thread, &java_thread, &thread_oop);
 974 
 975       if (thread_oop != nullptr &&
 976           java_lang_VirtualThread::is_instance(thread_oop) &&
 977           !JvmtiEnvBase::is_vthread_alive(thread_oop)) {
 978         err = JVMTI_ERROR_THREAD_NOT_ALIVE;
 979       }
 980       if (err != JVMTI_ERROR_NONE) {
 981         if (thread_oop == nullptr || err != JVMTI_ERROR_INVALID_THREAD) {
 982           results[i] = err;
 983           continue;
 984         }
 985       }
 986       if (java_thread == current) {
 987         self_idx = i;
 988         self_tobj = Handle(current, thread_oop);
 989         continue; // self suspend after all other suspends
 990       }
 991       results[i] = suspend_thread(thread_oop, java_thread, /* single_suspend */ true);
 992     }
 993   }
 994   // Self suspend after all other suspends if necessary.
 995   // Do not use JvmtiVTMSTransitionDisabler in context of self suspend to avoid deadlocks.
 996   if (self_tobj() != nullptr) {
 997     // there should not be any error for current java_thread
 998     results[self_idx] = suspend_thread(self_tobj(), current, /* single_suspend */ true);
 999   }
1000   // per-thread suspend results returned via results parameter
1001   return JVMTI_ERROR_NONE;
1002 } /* end SuspendThreadList */
1003 
1004 
1005 jvmtiError
1006 JvmtiEnv::SuspendAllVirtualThreads(jint except_count, const jthread* except_list) {
1007   if (get_capabilities()->can_support_virtual_threads == 0) {
1008     return JVMTI_ERROR_MUST_POSSESS_CAPABILITY;
1009   }
1010   JavaThread* current = JavaThread::current();
1011   HandleMark hm(current);
1012   Handle self_tobj;
1013 
1014   {
1015     ResourceMark rm(current);
1016     JvmtiVTMSTransitionDisabler disabler(true);
1017     ThreadsListHandle tlh(current);
1018     GrowableArray<jthread>* elist = new GrowableArray<jthread>(except_count);
1019 
1020     jvmtiError err = JvmtiEnvBase::check_thread_list(except_count, except_list);
1021     if (err != JVMTI_ERROR_NONE) {
1022       return err;
1023     }
1024 
1025     // Collect threads from except_list for which resumed status must be restored (only for VirtualThread case)
1026     for (int idx = 0; idx < except_count; idx++) {
1027       jthread thread = except_list[idx];
1028       oop thread_oop = JNIHandles::resolve_external_guard(thread);
1029       if (java_lang_VirtualThread::is_instance(thread_oop) && !JvmtiVTSuspender::is_vthread_suspended(thread_oop)) {
1030           // is not suspended, so its resumed status must be restored
1031           elist->append(except_list[idx]);
1032       }
1033     }
1034 
1035     for (JavaThreadIteratorWithHandle jtiwh; JavaThread *java_thread = jtiwh.next(); ) {
1036       oop vt_oop = java_thread->jvmti_vthread();
1037       if (!java_thread->is_exiting() &&
1038           !java_thread->is_jvmti_agent_thread() &&
1039           !java_thread->is_hidden_from_external_view() &&
1040           vt_oop != nullptr &&
1041           ((java_lang_VirtualThread::is_instance(vt_oop) &&
1042             JvmtiEnvBase::is_vthread_alive(vt_oop) &&
1043             !JvmtiVTSuspender::is_vthread_suspended(vt_oop)) ||
1044             (vt_oop->is_a(vmClasses::BoundVirtualThread_klass()) && !java_thread->is_suspended())) &&
1045           !is_in_thread_list(except_count, except_list, vt_oop)
1046          ) {
1047         if (java_thread == current) {
1048           self_tobj = Handle(current, vt_oop);
1049           continue; // self suspend after all other suspends
1050         }
1051         suspend_thread(vt_oop, java_thread, /* single_suspend */ false);
1052       }
1053     }
1054     JvmtiVTSuspender::register_all_vthreads_suspend();
1055 
1056     // Restore resumed state for threads from except list that were not suspended before.
1057     for (int idx = 0; idx < elist->length(); idx++) {
1058       jthread thread = elist->at(idx);
1059       oop thread_oop = JNIHandles::resolve_external_guard(thread);
1060       if (JvmtiVTSuspender::is_vthread_suspended(thread_oop)) {
1061         JvmtiVTSuspender::register_vthread_resume(thread_oop);
1062       }
1063     }
1064   }
1065   // Self suspend after all other suspends if necessary.
1066   // Do not use JvmtiVTMSTransitionDisabler in context of self suspend to avoid deadlocks.
1067   if (self_tobj() != nullptr) {
1068     suspend_thread(self_tobj(), current, /* single_suspend */ false);
1069   }
1070   return JVMTI_ERROR_NONE;
1071 } /* end SuspendAllVirtualThreads */
1072 
1073 
1074 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
1075 jvmtiError
1076 JvmtiEnv::ResumeThread(jthread thread) {
1077   JvmtiVTMSTransitionDisabler disabler(true);
1078   JavaThread* current = JavaThread::current();
1079   ThreadsListHandle tlh(current);
1080 
1081   JavaThread* java_thread = nullptr;
1082   oop thread_oop = nullptr;
1083   jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, current, &java_thread, &thread_oop);
1084   if (err != JVMTI_ERROR_NONE) {
1085     return err;
1086   }
1087   err = resume_thread(thread_oop, java_thread, /* single_resume */ true);
1088   return err;
1089 } /* end ResumeThread */
1090 
1091 
1092 // request_count - pre-checked to be greater than or equal to 0
1093 // request_list - pre-checked for null
1094 // results - pre-checked for null
1095 jvmtiError
1096 JvmtiEnv::ResumeThreadList(jint request_count, const jthread* request_list, jvmtiError* results) {
1097   oop thread_oop = nullptr;
1098   JavaThread* java_thread = nullptr;
1099   JvmtiVTMSTransitionDisabler disabler(true);
1100   ThreadsListHandle tlh;
1101 
1102   for (int i = 0; i < request_count; i++) {
1103     jthread thread = request_list[i];
1104     jvmtiError err = JvmtiExport::cv_external_thread_to_JavaThread(tlh.list(), thread, &java_thread, &thread_oop);
1105 
1106     if (thread_oop != nullptr &&
1107         java_lang_VirtualThread::is_instance(thread_oop) &&
1108         !JvmtiEnvBase::is_vthread_alive(thread_oop)) {
1109       err = JVMTI_ERROR_THREAD_NOT_ALIVE;
1110     }
1111     if (err != JVMTI_ERROR_NONE) {
1112       if (thread_oop == nullptr || err != JVMTI_ERROR_INVALID_THREAD) {
1113         results[i] = err;
1114         continue;
1115       }
1116     }
1117     results[i] = resume_thread(thread_oop, java_thread, /* single_resume */ true);
1118   }
1119   // per-thread resume results returned via results parameter
1120   return JVMTI_ERROR_NONE;
1121 } /* end ResumeThreadList */
1122 
1123 
1124 jvmtiError
1125 JvmtiEnv::ResumeAllVirtualThreads(jint except_count, const jthread* except_list) {
1126   if (get_capabilities()->can_support_virtual_threads == 0) {
1127     return JVMTI_ERROR_MUST_POSSESS_CAPABILITY;
1128   }
1129   jvmtiError err = JvmtiEnvBase::check_thread_list(except_count, except_list);
1130   if (err != JVMTI_ERROR_NONE) {
1131     return err;
1132   }
1133   ResourceMark rm;
1134   JvmtiVTMSTransitionDisabler disabler(true);
1135   GrowableArray<jthread>* elist = new GrowableArray<jthread>(except_count);
1136 
1137   // Collect threads from except_list for which suspended status must be restored (only for VirtualThread case)
1138   for (int idx = 0; idx < except_count; idx++) {
1139     jthread thread = except_list[idx];
1140     oop thread_oop = JNIHandles::resolve_external_guard(thread);
1141     if (java_lang_VirtualThread::is_instance(thread_oop) && JvmtiVTSuspender::is_vthread_suspended(thread_oop)) {
1142       // is suspended, so its suspended status must be restored
1143       elist->append(except_list[idx]);
1144     }
1145   }
1146 
1147   for (JavaThreadIteratorWithHandle jtiwh; JavaThread *java_thread = jtiwh.next(); ) {
1148     oop vt_oop = java_thread->jvmti_vthread();
1149     if (!java_thread->is_exiting() &&
1150         !java_thread->is_jvmti_agent_thread() &&
1151         !java_thread->is_hidden_from_external_view() &&
1152         vt_oop != nullptr &&
1153         ((java_lang_VirtualThread::is_instance(vt_oop) &&
1154           JvmtiEnvBase::is_vthread_alive(vt_oop) &&
1155           JvmtiVTSuspender::is_vthread_suspended(vt_oop)) ||
1156           (vt_oop->is_a(vmClasses::BoundVirtualThread_klass()) && java_thread->is_suspended())) &&
1157         !is_in_thread_list(except_count, except_list, vt_oop)
1158     ) {
1159       resume_thread(vt_oop, java_thread, /* single_resume */ false);
1160     }
1161   }
1162   JvmtiVTSuspender::register_all_vthreads_resume();
1163 
1164   // Restore suspended state for threads from except list that were suspended before.
1165   for (int idx = 0; idx < elist->length(); idx++) {
1166     jthread thread = elist->at(idx);
1167     oop thread_oop = JNIHandles::resolve_external_guard(thread);
1168     if (!JvmtiVTSuspender::is_vthread_suspended(thread_oop)) {
1169       JvmtiVTSuspender::register_vthread_suspend(thread_oop);
1170     }
1171   }
1172   return JVMTI_ERROR_NONE;
1173 } /* end ResumeAllVirtualThreads */
1174 
1175 
1176 jvmtiError
1177 JvmtiEnv::StopThread(jthread thread, jobject exception) {
1178   JavaThread* current_thread = JavaThread::current();
1179 
1180   JvmtiVTMSTransitionDisabler disabler(thread);
1181   ThreadsListHandle tlh(current_thread);
1182   JavaThread* java_thread = nullptr;
1183   oop thread_oop = nullptr;
1184 
1185   NULL_CHECK(thread, JVMTI_ERROR_INVALID_THREAD);
1186 
1187   jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, current_thread, &java_thread, &thread_oop);
1188 
1189   bool is_virtual = thread_oop != nullptr && thread_oop->is_a(vmClasses::BaseVirtualThread_klass());
1190 
1191   if (is_virtual && !is_JavaThread_current(java_thread, thread_oop)) {
1192     if (!is_vthread_suspended(thread_oop, java_thread)) {
1193       return JVMTI_ERROR_THREAD_NOT_SUSPENDED;
1194     }
1195     if (java_thread == nullptr) { // unmounted virtual thread
1196       return JVMTI_ERROR_OPAQUE_FRAME;
1197     }
1198   }
1199   if (err != JVMTI_ERROR_NONE) {
1200     return err;
1201   }
1202   oop e = JNIHandles::resolve_external_guard(exception);
1203   NULL_CHECK(e, JVMTI_ERROR_NULL_POINTER);
1204 
1205   JavaThread::send_async_exception(java_thread, e);
1206 
1207   return JVMTI_ERROR_NONE;
1208 
1209 } /* end StopThread */
1210 
1211 
1212 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
1213 jvmtiError
1214 JvmtiEnv::InterruptThread(jthread thread) {
1215   JavaThread* current_thread = JavaThread::current();
1216   HandleMark hm(current_thread);
1217 
1218   JvmtiVTMSTransitionDisabler disabler(thread);
1219   ThreadsListHandle tlh(current_thread);
1220 
1221   JavaThread* java_thread = nullptr;
1222   oop thread_obj = nullptr;
1223   jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, current_thread, &java_thread, &thread_obj);
1224   if (err != JVMTI_ERROR_NONE) {
1225     return err;
1226   }
1227 
1228   if (java_lang_VirtualThread::is_instance(thread_obj)) {
1229     // For virtual threads we have to call into Java to interrupt:
1230     Handle obj(current_thread, thread_obj);
1231     JvmtiJavaUpcallMark jjum(current_thread); // hide JVMTI events for Java upcall
1232     JavaValue result(T_VOID);
1233     JavaCalls::call_virtual(&result,
1234                             obj,
1235                             vmClasses::Thread_klass(),
1236                             vmSymbols::interrupt_method_name(),
1237                             vmSymbols::void_method_signature(),
1238                             current_thread);
1239 
1240     return JVMTI_ERROR_NONE;
1241   }
1242 
1243   // Really this should be a Java call to Thread.interrupt to ensure the same
1244   // semantics, however historically this has not been done for some reason.
1245   // So we continue with that (which means we don't interact with any Java-level
1246   // Interruptible object) but we must set the Java-level interrupted state.
1247   java_lang_Thread::set_interrupted(thread_obj, true);
1248   java_thread->interrupt();
1249 
1250   return JVMTI_ERROR_NONE;
1251 } /* end InterruptThread */
1252 
1253 
1254 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
1255 // info_ptr - pre-checked for null
1256 jvmtiError
1257 JvmtiEnv::GetThreadInfo(jthread thread, jvmtiThreadInfo* info_ptr) {
1258   JavaThread* current_thread = JavaThread::current();
1259   ResourceMark rm(current_thread);
1260   HandleMark hm(current_thread);
1261   JavaThread* java_thread = nullptr;
1262   oop thread_oop = nullptr;
1263 
1264   JvmtiVTMSTransitionDisabler disabler(thread);
1265   ThreadsListHandle tlh(current_thread);
1266 
1267   // if thread is null the current thread is used
1268   if (thread == nullptr) {
1269     java_thread = JavaThread::current();
1270     thread_oop = get_vthread_or_thread_oop(java_thread);
1271     if (thread_oop == nullptr || !thread_oop->is_a(vmClasses::Thread_klass())) {
1272       return JVMTI_ERROR_INVALID_THREAD;
1273     }
1274   } else {
1275     jvmtiError err = JvmtiExport::cv_external_thread_to_JavaThread(tlh.list(), thread, &java_thread, &thread_oop);
1276     if (err != JVMTI_ERROR_NONE) {
1277       // We got an error code so we don't have a JavaThread *, but
1278       // only return an error from here if we didn't get a valid
1279       // thread_oop.
1280       // In the virtual thread case the cv_external_thread_to_JavaThread is expected to correctly set
1281       // the thread_oop and return JVMTI_ERROR_INVALID_THREAD which we ignore here.
1282       if (thread_oop == nullptr) {
1283         return err;
1284       }
1285     }
1286   }
1287   // We have a valid thread_oop so we can return some thread info.
1288 
1289   Handle thread_obj(current_thread, thread_oop);
1290   Handle name;
1291   ThreadPriority priority;
1292   Handle     thread_group;
1293   Handle context_class_loader;
1294   bool          is_daemon;
1295 
1296   name = Handle(current_thread, java_lang_Thread::name(thread_obj()));
1297 
1298   if (java_lang_VirtualThread::is_instance(thread_obj())) {
1299     priority = (ThreadPriority)JVMTI_THREAD_NORM_PRIORITY;
1300     is_daemon = true;
1301     if (java_lang_VirtualThread::state(thread_obj()) == java_lang_VirtualThread::TERMINATED) {
1302       thread_group = Handle(current_thread, nullptr);
1303     } else {
1304       thread_group = Handle(current_thread, java_lang_Thread_Constants::get_VTHREAD_GROUP());
1305     }
1306   } else {
1307     priority = java_lang_Thread::priority(thread_obj());
1308     is_daemon = java_lang_Thread::is_daemon(thread_obj());
1309     if (java_lang_Thread::get_thread_status(thread_obj()) == JavaThreadStatus::TERMINATED) {
1310       thread_group = Handle(current_thread, nullptr);
1311     } else {
1312       thread_group = Handle(current_thread, java_lang_Thread::threadGroup(thread_obj()));
1313     }
1314   }
1315 
1316   oop loader = java_lang_Thread::context_class_loader(thread_obj());
1317   context_class_loader = Handle(current_thread, loader);
1318 
1319   { const char *n;
1320 
1321     if (name() != nullptr) {
1322       n = java_lang_String::as_utf8_string(name());
1323     } else {
1324       size_t utf8_length = 0;
1325       n = UNICODE::as_utf8((jchar*) nullptr, utf8_length);
1326     }
1327 
1328     info_ptr->name = (char *) jvmtiMalloc(strlen(n)+1);
1329     if (info_ptr->name == nullptr)
1330       return JVMTI_ERROR_OUT_OF_MEMORY;
1331 
1332     strcpy(info_ptr->name, n);
1333   }
1334   info_ptr->is_daemon = is_daemon;
1335   info_ptr->priority  = priority;
1336 
1337   info_ptr->context_class_loader = (context_class_loader.is_null()) ? nullptr :
1338                                     jni_reference(context_class_loader);
1339   info_ptr->thread_group = jni_reference(thread_group);
1340 
1341   return JVMTI_ERROR_NONE;
1342 } /* end GetThreadInfo */
1343 
1344 
1345 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
1346 // owned_monitor_count_ptr - pre-checked for null
1347 // owned_monitors_ptr - pre-checked for null
1348 jvmtiError
1349 JvmtiEnv::GetOwnedMonitorInfo(jthread thread, jint* owned_monitor_count_ptr, jobject** owned_monitors_ptr) {
1350   JavaThread* calling_thread = JavaThread::current();
1351   HandleMark hm(calling_thread);
1352 
1353   JvmtiVTMSTransitionDisabler disabler(thread);
1354   ThreadsListHandle tlh(calling_thread);
1355 
1356   JavaThread* java_thread = nullptr;
1357   oop thread_oop = nullptr;
1358   jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, calling_thread, &java_thread, &thread_oop);
1359   if (err != JVMTI_ERROR_NONE) {
1360     return err;
1361   }
1362 
1363   if (LockingMode == LM_LEGACY && java_thread == nullptr) {
1364     *owned_monitor_count_ptr = 0;
1365     return JVMTI_ERROR_NONE;
1366   }
1367 
1368   // growable array of jvmti monitors info on the C-heap
1369   GrowableArray<jvmtiMonitorStackDepthInfo*> *owned_monitors_list =
1370       new (mtServiceability) GrowableArray<jvmtiMonitorStackDepthInfo*>(1, mtServiceability);
1371 
1372   Handle thread_handle(calling_thread, thread_oop);
1373   EscapeBarrier eb(java_thread != nullptr, calling_thread, java_thread);
1374   if (!eb.deoptimize_objects(MaxJavaStackTraceDepth)) {
1375     delete owned_monitors_list;
1376     return JVMTI_ERROR_OUT_OF_MEMORY;
1377   }
1378   // get owned monitors info with handshake
1379   GetOwnedMonitorInfoClosure op(this, calling_thread, owned_monitors_list);
1380   JvmtiHandshake::execute(&op, &tlh, java_thread, thread_handle);
1381   err = op.result();
1382 
1383   jint owned_monitor_count = owned_monitors_list->length();
1384   if (err == JVMTI_ERROR_NONE) {
1385     if ((err = allocate(owned_monitor_count * sizeof(jobject *),
1386                       (unsigned char**)owned_monitors_ptr)) == JVMTI_ERROR_NONE) {
1387       // copy into the returned array
1388       for (int i = 0; i < owned_monitor_count; i++) {
1389         (*owned_monitors_ptr)[i] =
1390           ((jvmtiMonitorStackDepthInfo*)owned_monitors_list->at(i))->monitor;
1391       }
1392       *owned_monitor_count_ptr = owned_monitor_count;
1393     }
1394   }
1395   // clean up.
1396   for (int i = 0; i < owned_monitor_count; i++) {
1397     deallocate((unsigned char*)owned_monitors_list->at(i));
1398   }
1399   delete owned_monitors_list;
1400 
1401   return err;
1402 } /* end GetOwnedMonitorInfo */
1403 
1404 
1405 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
1406 // monitor_info_count_ptr - pre-checked for null
1407 // monitor_info_ptr - pre-checked for null
1408 jvmtiError
1409 JvmtiEnv::GetOwnedMonitorStackDepthInfo(jthread thread, jint* monitor_info_count_ptr, jvmtiMonitorStackDepthInfo** monitor_info_ptr) {
1410   JavaThread* calling_thread = JavaThread::current();
1411   HandleMark hm(calling_thread);
1412 
1413   JvmtiVTMSTransitionDisabler disabler(thread);
1414   ThreadsListHandle tlh(calling_thread);
1415 
1416   JavaThread* java_thread = nullptr;
1417   oop thread_oop = nullptr;
1418   jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, calling_thread, &java_thread, &thread_oop);
1419   if (err != JVMTI_ERROR_NONE) {
1420     return err;
1421   }
1422 
1423   if (LockingMode == LM_LEGACY && java_thread == nullptr) {
1424     *monitor_info_count_ptr = 0;
1425     return JVMTI_ERROR_NONE;
1426   }
1427 
1428   // growable array of jvmti monitors info on the C-heap
1429   GrowableArray<jvmtiMonitorStackDepthInfo*> *owned_monitors_list =
1430       new (mtServiceability) GrowableArray<jvmtiMonitorStackDepthInfo*>(1, mtServiceability);
1431 
1432   Handle thread_handle(calling_thread, thread_oop);
1433   EscapeBarrier eb(java_thread != nullptr, calling_thread, java_thread);
1434   if (!eb.deoptimize_objects(MaxJavaStackTraceDepth)) {
1435     delete owned_monitors_list;
1436     return JVMTI_ERROR_OUT_OF_MEMORY;
1437   }
1438   // get owned monitors info with handshake
1439   GetOwnedMonitorInfoClosure op(this, calling_thread, owned_monitors_list);
1440   JvmtiHandshake::execute(&op, &tlh, java_thread, thread_handle);
1441   err = op.result();
1442 
1443   jint owned_monitor_count = owned_monitors_list->length();
1444   if (err == JVMTI_ERROR_NONE) {
1445     if ((err = allocate(owned_monitor_count * sizeof(jvmtiMonitorStackDepthInfo),
1446                         (unsigned char**)monitor_info_ptr)) == JVMTI_ERROR_NONE) {
1447       // copy to output array.
1448       for (int i = 0; i < owned_monitor_count; i++) {
1449         (*monitor_info_ptr)[i].monitor =
1450           ((jvmtiMonitorStackDepthInfo*)owned_monitors_list->at(i))->monitor;
1451         (*monitor_info_ptr)[i].stack_depth =
1452           ((jvmtiMonitorStackDepthInfo*)owned_monitors_list->at(i))->stack_depth;
1453       }
1454     }
1455     *monitor_info_count_ptr = owned_monitor_count;
1456   }
1457 
1458   // clean up.
1459   for (int i = 0; i < owned_monitor_count; i++) {
1460     deallocate((unsigned char*)owned_monitors_list->at(i));
1461   }
1462   delete owned_monitors_list;
1463 
1464   return err;
1465 } /* end GetOwnedMonitorStackDepthInfo */
1466 
1467 
1468 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
1469 // monitor_ptr - pre-checked for null
1470 jvmtiError
1471 JvmtiEnv::GetCurrentContendedMonitor(jthread thread, jobject* monitor_ptr) {
1472   JavaThread* current = JavaThread::current();
1473 
1474   *monitor_ptr = nullptr;
1475 
1476   // get contended monitor information with handshake
1477   GetCurrentContendedMonitorClosure op(this, current, monitor_ptr);
1478   JvmtiHandshake::execute(&op, thread);
1479   return op.result();
1480 } /* end GetCurrentContendedMonitor */
1481 
1482 
1483 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
1484 // proc - pre-checked for null
1485 // arg - null is a valid value, must be checked
1486 jvmtiError
1487 JvmtiEnv::RunAgentThread(jthread thread, jvmtiStartFunction proc, const void* arg, jint priority) {
1488   JavaThread* current_thread = JavaThread::current();
1489 
1490   JavaThread* java_thread = nullptr;
1491   oop thread_oop = nullptr;
1492   ThreadsListHandle tlh(current_thread);
1493   jvmtiError err = JvmtiExport::cv_external_thread_to_JavaThread(tlh.list(), thread, &java_thread, &thread_oop);
1494   if (err != JVMTI_ERROR_NONE) {
1495     // We got an error code so we don't have a JavaThread *, but
1496     // only return an error from here if we didn't get a valid
1497     // thread_oop.
1498     if (thread_oop == nullptr) {
1499       return err;
1500     }
1501     // We have a valid thread_oop.
1502   }
1503 
1504   if (thread_oop->is_a(vmClasses::BaseVirtualThread_klass())) {
1505     // No support for virtual threads.
1506     return JVMTI_ERROR_UNSUPPORTED_OPERATION;
1507   }
1508   if (java_thread != nullptr) {
1509     // 'thread' refers to an existing JavaThread.
1510     return JVMTI_ERROR_INVALID_THREAD;
1511   }
1512 
1513   if (priority < JVMTI_THREAD_MIN_PRIORITY || priority > JVMTI_THREAD_MAX_PRIORITY) {
1514     return JVMTI_ERROR_INVALID_PRIORITY;
1515   }
1516 
1517   Handle thread_hndl(current_thread, thread_oop);
1518 
1519   JvmtiAgentThread* new_thread = new JvmtiAgentThread(this, proc, arg);
1520 
1521   // At this point it may be possible that no osthread was created for the
1522   // JavaThread due to lack of resources.
1523   if (new_thread->osthread() == nullptr) {
1524     // The new thread is not known to Thread-SMR yet so we can just delete.
1525     delete new_thread;
1526     return JVMTI_ERROR_OUT_OF_MEMORY;
1527   }
1528 
1529   JavaThread::start_internal_daemon(current_thread, new_thread, thread_hndl,
1530                                     (ThreadPriority)priority);
1531 
1532   return JVMTI_ERROR_NONE;
1533 } /* end RunAgentThread */
1534 
1535   //
1536   // Thread Group functions
1537   //
1538 
1539 // group_count_ptr - pre-checked for null
1540 // groups_ptr - pre-checked for null
1541 jvmtiError
1542 JvmtiEnv::GetTopThreadGroups(jint* group_count_ptr, jthreadGroup** groups_ptr) {
1543   JavaThread* current_thread = JavaThread::current();
1544 
1545   // Only one top level thread group now.
1546   *group_count_ptr = 1;
1547 
1548   // Allocate memory to store global-refs to the thread groups.
1549   // Assume this area is freed by caller.
1550   *groups_ptr = (jthreadGroup *) jvmtiMalloc((sizeof(jthreadGroup)) * (*group_count_ptr));
1551 
1552   NULL_CHECK(*groups_ptr, JVMTI_ERROR_OUT_OF_MEMORY);
1553 
1554   // Convert oop to Handle, then convert Handle to global-ref.
1555   {
1556     HandleMark hm(current_thread);
1557     Handle system_thread_group(current_thread, Universe::system_thread_group());
1558     *groups_ptr[0] = jni_reference(system_thread_group);
1559   }
1560 
1561   return JVMTI_ERROR_NONE;
1562 } /* end GetTopThreadGroups */
1563 
1564 
1565 // info_ptr - pre-checked for null
1566 jvmtiError
1567 JvmtiEnv::GetThreadGroupInfo(jthreadGroup group, jvmtiThreadGroupInfo* info_ptr) {
1568   Thread* current_thread = Thread::current();
1569   ResourceMark rm(current_thread);
1570   HandleMark hm(current_thread);
1571 
1572   Handle group_obj (current_thread, JNIHandles::resolve_external_guard(group));
1573   NULL_CHECK(group_obj(), JVMTI_ERROR_INVALID_THREAD_GROUP);
1574 
1575   const char* name;
1576   Handle parent_group;
1577   bool is_daemon;
1578   ThreadPriority max_priority;
1579 
1580   name         = java_lang_ThreadGroup::name(group_obj());
1581   parent_group = Handle(current_thread, java_lang_ThreadGroup::parent(group_obj()));
1582   is_daemon    = java_lang_ThreadGroup::is_daemon(group_obj());
1583   max_priority = java_lang_ThreadGroup::maxPriority(group_obj());
1584 
1585   info_ptr->is_daemon    = is_daemon;
1586   info_ptr->max_priority = max_priority;
1587   info_ptr->parent       = jni_reference(parent_group);
1588 
1589   if (name != nullptr) {
1590     info_ptr->name = (char*)jvmtiMalloc(strlen(name)+1);
1591     NULL_CHECK(info_ptr->name, JVMTI_ERROR_OUT_OF_MEMORY);
1592     strcpy(info_ptr->name, name);
1593   } else {
1594     info_ptr->name = nullptr;
1595   }
1596 
1597   return JVMTI_ERROR_NONE;
1598 } /* end GetThreadGroupInfo */
1599 
1600 // thread_count_ptr - pre-checked for null
1601 // threads_ptr - pre-checked for null
1602 // group_count_ptr - pre-checked for null
1603 // groups_ptr - pre-checked for null
1604 jvmtiError
1605 JvmtiEnv::GetThreadGroupChildren(jthreadGroup group, jint* thread_count_ptr, jthread** threads_ptr, jint* group_count_ptr, jthreadGroup** groups_ptr) {
1606   jvmtiError err;
1607   JavaThread* current_thread = JavaThread::current();
1608   oop group_obj = JNIHandles::resolve_external_guard(group);
1609   NULL_CHECK(group_obj, JVMTI_ERROR_INVALID_THREAD_GROUP);
1610 
1611   Handle *thread_objs = nullptr;
1612   objArrayHandle group_objs;
1613   jint nthreads = 0;
1614   jint ngroups = 0;
1615   int hidden_threads = 0;
1616 
1617   ResourceMark rm(current_thread);
1618   HandleMark hm(current_thread);
1619 
1620   Handle group_hdl(current_thread, group_obj);
1621 
1622   err = get_live_threads(current_thread, group_hdl, &nthreads, &thread_objs);
1623   if (err != JVMTI_ERROR_NONE) {
1624     return err;
1625   }
1626   err = get_subgroups(current_thread, group_hdl, &ngroups, &group_objs);
1627   if (err != JVMTI_ERROR_NONE) {
1628     return err;
1629   }
1630 
1631   *group_count_ptr  = ngroups;
1632   *thread_count_ptr = nthreads;
1633   *threads_ptr     = new_jthreadArray(nthreads, thread_objs);
1634   *groups_ptr      = new_jthreadGroupArray(ngroups, group_objs);
1635   if (nthreads > 0 && *threads_ptr == nullptr) {
1636     return JVMTI_ERROR_OUT_OF_MEMORY;
1637   }
1638   if (ngroups > 0 && *groups_ptr == nullptr) {
1639     return JVMTI_ERROR_OUT_OF_MEMORY;
1640   }
1641 
1642   return JVMTI_ERROR_NONE;
1643 } /* end GetThreadGroupChildren */
1644 
1645 
1646   //
1647   // Stack Frame functions
1648   //
1649 
1650 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
1651 // max_frame_count - pre-checked to be greater than or equal to 0
1652 // frame_buffer - pre-checked for null
1653 // count_ptr - pre-checked for null
1654 jvmtiError
1655 JvmtiEnv::GetStackTrace(jthread thread, jint start_depth, jint max_frame_count, jvmtiFrameInfo* frame_buffer, jint* count_ptr) {
1656   GetStackTraceClosure op(this, start_depth, max_frame_count, frame_buffer, count_ptr);
1657   JvmtiHandshake::execute(&op, thread);
1658   return op.result();
1659 } /* end GetStackTrace */
1660 
1661 
1662 // max_frame_count - pre-checked to be greater than or equal to 0
1663 // stack_info_ptr - pre-checked for null
1664 // thread_count_ptr - pre-checked for null
1665 jvmtiError
1666 JvmtiEnv::GetAllStackTraces(jint max_frame_count, jvmtiStackInfo** stack_info_ptr, jint* thread_count_ptr) {
1667   jvmtiError err = JVMTI_ERROR_NONE;
1668   JavaThread* calling_thread = JavaThread::current();
1669 
1670   // JVMTI get stack traces at safepoint.
1671   VM_GetAllStackTraces op(this, calling_thread, max_frame_count);
1672   VMThread::execute(&op);
1673   *thread_count_ptr = op.final_thread_count();
1674   *stack_info_ptr = op.stack_info();
1675   err = op.result();
1676   return err;
1677 } /* end GetAllStackTraces */
1678 
1679 
1680 // thread_count - pre-checked to be greater than or equal to 0
1681 // thread_list - pre-checked for null
1682 // max_frame_count - pre-checked to be greater than or equal to 0
1683 // stack_info_ptr - pre-checked for null
1684 jvmtiError
1685 JvmtiEnv::GetThreadListStackTraces(jint thread_count, const jthread* thread_list, jint max_frame_count, jvmtiStackInfo** stack_info_ptr) {
1686   jvmtiError err = JVMTI_ERROR_NONE;
1687 
1688   if (thread_count == 1) {
1689     // Use direct handshake if we need to get only one stack trace.
1690     JavaThread *current_thread = JavaThread::current();
1691 
1692     jthread thread = thread_list[0];
1693 
1694     GetSingleStackTraceClosure op(this, current_thread, thread, max_frame_count);
1695     JvmtiHandshake::execute(&op, thread);
1696     err = op.result();
1697     if (err == JVMTI_ERROR_NONE) {
1698       *stack_info_ptr = op.stack_info();
1699     }
1700   } else {
1701     JvmtiVTMSTransitionDisabler disabler;
1702 
1703     // JVMTI get stack traces at safepoint.
1704     VM_GetThreadListStackTraces op(this, thread_count, thread_list, max_frame_count);
1705     VMThread::execute(&op);
1706     err = op.result();
1707     if (err == JVMTI_ERROR_NONE) {
1708       *stack_info_ptr = op.stack_info();
1709     }
1710   }
1711   return err;
1712 } /* end GetThreadListStackTraces */
1713 
1714 
1715 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
1716 // count_ptr - pre-checked for null
1717 jvmtiError
1718 JvmtiEnv::GetFrameCount(jthread thread, jint* count_ptr) {
1719   GetFrameCountClosure op(this, count_ptr);
1720   JvmtiHandshake::execute(&op, thread);
1721   return op.result();
1722 } /* end GetFrameCount */
1723 
1724 
1725 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
1726 jvmtiError
1727 JvmtiEnv::PopFrame(jthread thread) {
1728   JavaThread* current_thread = JavaThread::current();
1729   HandleMark hm(current_thread);
1730 
1731   if (thread == nullptr) {
1732     return JVMTI_ERROR_INVALID_THREAD;
1733   }
1734   JvmtiVTMSTransitionDisabler disabler(thread);
1735   ThreadsListHandle tlh(current_thread);
1736 
1737   JavaThread* java_thread = nullptr;
1738   oop thread_obj = nullptr;
1739   jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, current_thread, &java_thread, &thread_obj);
1740   Handle thread_handle(current_thread, thread_obj);
1741 
1742   if (err != JVMTI_ERROR_NONE) {
1743     return err;
1744   }
1745   bool self = java_thread == current_thread;
1746 
1747   err = check_non_suspended_or_opaque_frame(java_thread, thread_obj, self);
1748   if (err != JVMTI_ERROR_NONE) {
1749     return err;
1750   }
1751 
1752   // retrieve or create the state
1753   JvmtiThreadState* state = JvmtiThreadState::state_for(java_thread);
1754   if (state == nullptr) {
1755     return JVMTI_ERROR_THREAD_NOT_ALIVE;
1756   }
1757 
1758   // Eagerly reallocate scalar replaced objects.
1759   EscapeBarrier eb(true, current_thread, java_thread);
1760   if (!eb.deoptimize_objects(1)) {
1761     // Reallocation of scalar replaced objects failed -> return with error
1762     return JVMTI_ERROR_OUT_OF_MEMORY;
1763   }
1764 
1765   MutexLocker mu(JvmtiThreadState_lock);
1766   UpdateForPopTopFrameClosure op(state);
1767   JvmtiHandshake::execute(&op, &tlh, java_thread, thread_handle);
1768   return op.result();
1769 } /* end PopFrame */
1770 
1771 
1772 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
1773 // depth - pre-checked as non-negative
1774 // method_ptr - pre-checked for null
1775 // location_ptr - pre-checked for null
1776 jvmtiError
1777 JvmtiEnv::GetFrameLocation(jthread thread, jint depth, jmethodID* method_ptr, jlocation* location_ptr) {
1778   GetFrameLocationClosure op(this, depth, method_ptr, location_ptr);
1779   JvmtiHandshake::execute(&op, thread);
1780   return op.result();
1781 } /* end GetFrameLocation */
1782 
1783 
1784 // Threads_lock NOT held, java_thread not protected by lock
1785 // depth - pre-checked as non-negative
1786 jvmtiError
1787 JvmtiEnv::NotifyFramePop(jthread thread, jint depth) {
1788   ResourceMark rm;
1789   JvmtiVTMSTransitionDisabler disabler(thread);
1790   JavaThread* current = JavaThread::current();
1791   ThreadsListHandle tlh(current);
1792 
1793   JavaThread* java_thread = nullptr;
1794   oop thread_obj = nullptr;
1795   jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, current, &java_thread, &thread_obj);
1796   if (err != JVMTI_ERROR_NONE) {
1797     return err;
1798   }
1799 
1800   HandleMark hm(current);
1801   Handle thread_handle(current, thread_obj);
1802   JvmtiThreadState *state = JvmtiThreadState::state_for(java_thread, thread_handle);
1803   if (state == nullptr) {
1804     return JVMTI_ERROR_THREAD_NOT_ALIVE;
1805   }
1806 
1807   SetOrClearFramePopClosure op(this, state, true /* set */, depth);
1808   MutexLocker mu(current, JvmtiThreadState_lock);
1809   JvmtiHandshake::execute(&op, &tlh, java_thread, thread_handle);
1810   return op.result();
1811 } /* end NotifyFramePop */
1812 
1813 // Threads_lock NOT held, java_thread not protected by lock
1814 jvmtiError
1815 JvmtiEnv::ClearAllFramePops(jthread thread) {
1816   ResourceMark rm;
1817   JvmtiVTMSTransitionDisabler disabler(thread);
1818   JavaThread* current = JavaThread::current();
1819   ThreadsListHandle tlh(current);
1820 
1821   JavaThread* java_thread = nullptr;
1822   oop thread_obj = nullptr;
1823   jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, current, &java_thread, &thread_obj);
1824   if (err != JVMTI_ERROR_NONE) {
1825     return err;
1826   }
1827 
1828   HandleMark hm(current);
1829   Handle thread_handle(current, thread_obj);
1830   JvmtiThreadState *state = JvmtiThreadState::state_for(java_thread, thread_handle);
1831   if (state == nullptr) {
1832     return JVMTI_ERROR_THREAD_NOT_ALIVE;
1833   }
1834 
1835   SetOrClearFramePopClosure op(this, state, false /* clear all frame pops*/);
1836   MutexLocker mu(current, JvmtiThreadState_lock);
1837   JvmtiHandshake::execute(&op, &tlh, java_thread, thread_handle);
1838   return op.result();
1839 } /* end ClearAllFramePops */
1840 
1841   //
1842   // Force Early Return functions
1843   //
1844 
1845 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
1846 jvmtiError
1847 JvmtiEnv::ForceEarlyReturnObject(jthread thread, jobject value) {
1848   jvalue val;
1849   val.l = value;
1850   return force_early_return(thread, val, atos);
1851 } /* end ForceEarlyReturnObject */
1852 
1853 
1854 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
1855 jvmtiError
1856 JvmtiEnv::ForceEarlyReturnInt(jthread thread, jint value) {
1857   jvalue val;
1858   val.i = value;
1859   return force_early_return(thread, val, itos);
1860 } /* end ForceEarlyReturnInt */
1861 
1862 
1863 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
1864 jvmtiError
1865 JvmtiEnv::ForceEarlyReturnLong(jthread thread, jlong value) {
1866   jvalue val;
1867   val.j = value;
1868   return force_early_return(thread, val, ltos);
1869 } /* end ForceEarlyReturnLong */
1870 
1871 
1872 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
1873 jvmtiError
1874 JvmtiEnv::ForceEarlyReturnFloat(jthread thread, jfloat value) {
1875   jvalue val;
1876   val.f = value;
1877   return force_early_return(thread, val, ftos);
1878 } /* end ForceEarlyReturnFloat */
1879 
1880 
1881 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
1882 jvmtiError
1883 JvmtiEnv::ForceEarlyReturnDouble(jthread thread, jdouble value) {
1884   jvalue val;
1885   val.d = value;
1886   return force_early_return(thread, val, dtos);
1887 } /* end ForceEarlyReturnDouble */
1888 
1889 
1890 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
1891 jvmtiError
1892 JvmtiEnv::ForceEarlyReturnVoid(jthread thread) {
1893   jvalue val;
1894   val.j = 0L;
1895   return force_early_return(thread, val, vtos);
1896 } /* end ForceEarlyReturnVoid */
1897 
1898 
1899   //
1900   // Heap functions
1901   //
1902 
1903 // klass - null is a valid value, must be checked
1904 // initial_object - null is a valid value, must be checked
1905 // callbacks - pre-checked for null
1906 // user_data - null is a valid value, must be checked
1907 jvmtiError
1908 JvmtiEnv::FollowReferences(jint heap_filter, jclass klass, jobject initial_object, const jvmtiHeapCallbacks* callbacks, const void* user_data) {
1909   // check klass if provided
1910   Klass* k = nullptr;
1911   if (klass != nullptr) {
1912     oop k_mirror = JNIHandles::resolve_external_guard(klass);
1913     if (k_mirror == nullptr) {
1914       return JVMTI_ERROR_INVALID_CLASS;
1915     }
1916     if (java_lang_Class::is_primitive(k_mirror)) {
1917       return JVMTI_ERROR_NONE;
1918     }
1919     k = java_lang_Class::as_Klass(k_mirror);
1920     if (klass == nullptr) {
1921       return JVMTI_ERROR_INVALID_CLASS;
1922     }
1923   }
1924 
1925   if (initial_object != nullptr) {
1926     oop init_obj = JNIHandles::resolve_external_guard(initial_object);
1927     if (init_obj == nullptr) {
1928       return JVMTI_ERROR_INVALID_OBJECT;
1929     }
1930   }
1931 
1932   Thread *thread = Thread::current();
1933   HandleMark hm(thread);
1934 
1935   TraceTime t("FollowReferences", TRACETIME_LOG(Debug, jvmti, objecttagging));
1936   JvmtiTagMap::tag_map_for(this)->follow_references(heap_filter, k, initial_object, callbacks, user_data);
1937   return JVMTI_ERROR_NONE;
1938 } /* end FollowReferences */
1939 
1940 
1941 // klass - null is a valid value, must be checked
1942 // callbacks - pre-checked for null
1943 // user_data - null is a valid value, must be checked
1944 jvmtiError
1945 JvmtiEnv::IterateThroughHeap(jint heap_filter, jclass klass, const jvmtiHeapCallbacks* callbacks, const void* user_data) {
1946   // check klass if provided
1947   Klass* k = nullptr;
1948   if (klass != nullptr) {
1949     oop k_mirror = JNIHandles::resolve_external_guard(klass);
1950     if (k_mirror == nullptr) {
1951       return JVMTI_ERROR_INVALID_CLASS;
1952     }
1953     if (java_lang_Class::is_primitive(k_mirror)) {
1954       return JVMTI_ERROR_NONE;
1955     }
1956     k = java_lang_Class::as_Klass(k_mirror);
1957     if (k == nullptr) {
1958       return JVMTI_ERROR_INVALID_CLASS;
1959     }
1960   }
1961 
1962   TraceTime t("IterateThroughHeap", TRACETIME_LOG(Debug, jvmti, objecttagging));
1963   JvmtiTagMap::tag_map_for(this)->iterate_through_heap(heap_filter, k, callbacks, user_data);
1964   return JVMTI_ERROR_NONE;
1965 } /* end IterateThroughHeap */
1966 
1967 
1968 // tag_ptr - pre-checked for null
1969 jvmtiError
1970 JvmtiEnv::GetTag(jobject object, jlong* tag_ptr) {
1971   oop o = JNIHandles::resolve_external_guard(object);
1972   NULL_CHECK(o, JVMTI_ERROR_INVALID_OBJECT);
1973   *tag_ptr = JvmtiTagMap::tag_map_for(this)->get_tag(object);
1974   return JVMTI_ERROR_NONE;
1975 } /* end GetTag */
1976 
1977 
1978 jvmtiError
1979 JvmtiEnv::SetTag(jobject object, jlong tag) {
1980   oop o = JNIHandles::resolve_external_guard(object);
1981   NULL_CHECK(o, JVMTI_ERROR_INVALID_OBJECT);
1982   JvmtiTagMap::tag_map_for(this)->set_tag(object, tag);
1983   return JVMTI_ERROR_NONE;
1984 } /* end SetTag */
1985 
1986 
1987 // tag_count - pre-checked to be greater than or equal to 0
1988 // tags - pre-checked for null
1989 // count_ptr - pre-checked for null
1990 // object_result_ptr - null is a valid value, must be checked
1991 // tag_result_ptr - null is a valid value, must be checked
1992 jvmtiError
1993 JvmtiEnv::GetObjectsWithTags(jint tag_count, const jlong* tags, jint* count_ptr, jobject** object_result_ptr, jlong** tag_result_ptr) {
1994   TraceTime t("GetObjectsWithTags", TRACETIME_LOG(Debug, jvmti, objecttagging));
1995   return JvmtiTagMap::tag_map_for(this)->get_objects_with_tags((jlong*)tags, tag_count, count_ptr, object_result_ptr, tag_result_ptr);
1996 } /* end GetObjectsWithTags */
1997 
1998 
1999 jvmtiError
2000 JvmtiEnv::ForceGarbageCollection() {
2001   Universe::heap()->collect(GCCause::_jvmti_force_gc);
2002   return JVMTI_ERROR_NONE;
2003 } /* end ForceGarbageCollection */
2004 
2005 
2006   //
2007   // Heap (1.0) functions
2008   //
2009 
2010 // object_reference_callback - pre-checked for null
2011 // user_data - null is a valid value, must be checked
2012 jvmtiError
2013 JvmtiEnv::IterateOverObjectsReachableFromObject(jobject object, jvmtiObjectReferenceCallback object_reference_callback, const void* user_data) {
2014   oop o = JNIHandles::resolve_external_guard(object);
2015   NULL_CHECK(o, JVMTI_ERROR_INVALID_OBJECT);
2016   JvmtiTagMap::tag_map_for(this)->iterate_over_objects_reachable_from_object(object, object_reference_callback, user_data);
2017   return JVMTI_ERROR_NONE;
2018 } /* end IterateOverObjectsReachableFromObject */
2019 
2020 
2021 // heap_root_callback - null is a valid value, must be checked
2022 // stack_ref_callback - null is a valid value, must be checked
2023 // object_ref_callback - null is a valid value, must be checked
2024 // user_data - null is a valid value, must be checked
2025 jvmtiError
2026 JvmtiEnv::IterateOverReachableObjects(jvmtiHeapRootCallback heap_root_callback, jvmtiStackReferenceCallback stack_ref_callback, jvmtiObjectReferenceCallback object_ref_callback, const void* user_data) {
2027   TraceTime t("IterateOverReachableObjects", TRACETIME_LOG(Debug, jvmti, objecttagging));
2028   JvmtiTagMap::tag_map_for(this)->iterate_over_reachable_objects(heap_root_callback, stack_ref_callback, object_ref_callback, user_data);
2029   return JVMTI_ERROR_NONE;
2030 } /* end IterateOverReachableObjects */
2031 
2032 
2033 // heap_object_callback - pre-checked for null
2034 // user_data - null is a valid value, must be checked
2035 jvmtiError
2036 JvmtiEnv::IterateOverHeap(jvmtiHeapObjectFilter object_filter, jvmtiHeapObjectCallback heap_object_callback, const void* user_data) {
2037   TraceTime t("IterateOverHeap", TRACETIME_LOG(Debug, jvmti, objecttagging));
2038   Thread *thread = Thread::current();
2039   HandleMark hm(thread);
2040   JvmtiTagMap::tag_map_for(this)->iterate_over_heap(object_filter, nullptr, heap_object_callback, user_data);
2041   return JVMTI_ERROR_NONE;
2042 } /* end IterateOverHeap */
2043 
2044 
2045 // k_mirror - may be primitive, this must be checked
2046 // heap_object_callback - pre-checked for null
2047 // user_data - null is a valid value, must be checked
2048 jvmtiError
2049 JvmtiEnv::IterateOverInstancesOfClass(oop k_mirror, jvmtiHeapObjectFilter object_filter, jvmtiHeapObjectCallback heap_object_callback, const void* user_data) {
2050   if (java_lang_Class::is_primitive(k_mirror)) {
2051     // DO PRIMITIVE CLASS PROCESSING
2052     return JVMTI_ERROR_NONE;
2053   }
2054   Klass* klass = java_lang_Class::as_Klass(k_mirror);
2055   if (klass == nullptr) {
2056     return JVMTI_ERROR_INVALID_CLASS;
2057   }
2058   TraceTime t("IterateOverInstancesOfClass", TRACETIME_LOG(Debug, jvmti, objecttagging));
2059   JvmtiTagMap::tag_map_for(this)->iterate_over_heap(object_filter, klass, heap_object_callback, user_data);
2060   return JVMTI_ERROR_NONE;
2061 } /* end IterateOverInstancesOfClass */
2062 
2063 
2064   //
2065   // Local Variable functions
2066   //
2067 
2068 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
2069 // depth - pre-checked as non-negative
2070 // value_ptr - pre-checked for null
2071 jvmtiError
2072 JvmtiEnv::GetLocalObject(jthread thread, jint depth, jint slot, jobject* value_ptr) {
2073   JavaThread* current_thread = JavaThread::current();
2074   // rm object is created to clean up the javaVFrame created in
2075   // doit_prologue(), but after doit() is finished with it.
2076   ResourceMark rm(current_thread);
2077   HandleMark hm(current_thread);
2078   JvmtiVTMSTransitionDisabler disabler(thread);
2079   ThreadsListHandle tlh(current_thread);
2080 
2081   JavaThread* java_thread = nullptr;
2082   oop thread_obj = nullptr;
2083   jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, current_thread, &java_thread, &thread_obj);
2084   if (err != JVMTI_ERROR_NONE) {
2085     return err;
2086   }
2087   bool self = is_JavaThread_current(java_thread, thread_obj);
2088 
2089   if (java_lang_VirtualThread::is_instance(thread_obj)) {
2090     VM_VirtualThreadGetOrSetLocal op(this, Handle(current_thread, thread_obj),
2091                                      current_thread, depth, slot, self);
2092     VMThread::execute(&op);
2093     err = op.result();
2094     if (err == JVMTI_ERROR_NONE) {
2095       *value_ptr = op.value().l;
2096     }
2097   } else {
2098     // Support for ordinary threads
2099     VM_GetOrSetLocal op(java_thread, current_thread, depth, slot, self);
2100     VMThread::execute(&op);
2101     err = op.result();
2102     if (err == JVMTI_ERROR_NONE) {
2103       *value_ptr = op.value().l;
2104     }
2105   }
2106   return err;
2107 } /* end GetLocalObject */
2108 
2109 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
2110 // depth - pre-checked as non-negative
2111 // value - pre-checked for null
2112 jvmtiError
2113 JvmtiEnv::GetLocalInstance(jthread thread, jint depth, jobject* value_ptr){
2114   JavaThread* current_thread = JavaThread::current();
2115   // rm object is created to clean up the javaVFrame created in
2116   // doit_prologue(), but after doit() is finished with it.
2117   ResourceMark rm(current_thread);
2118   HandleMark hm(current_thread);
2119   JvmtiVTMSTransitionDisabler disabler(thread);
2120   ThreadsListHandle tlh(current_thread);
2121 
2122   JavaThread* java_thread = nullptr;
2123   oop thread_obj = nullptr;
2124   jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, current_thread, &java_thread, &thread_obj);
2125   if (err != JVMTI_ERROR_NONE) {
2126     return err;
2127   }
2128   bool self = is_JavaThread_current(java_thread, thread_obj);
2129 
2130   if (java_lang_VirtualThread::is_instance(thread_obj)) {
2131     VM_VirtualThreadGetReceiver op(this, Handle(current_thread, thread_obj),
2132                                    current_thread, depth, self);
2133     VMThread::execute(&op);
2134     err = op.result();
2135     if (err == JVMTI_ERROR_NONE) {
2136       *value_ptr = op.value().l;
2137     }
2138   } else {
2139     // Support for ordinary threads
2140     VM_GetReceiver op(java_thread, current_thread, depth, self);
2141     VMThread::execute(&op);
2142     err = op.result();
2143     if (err == JVMTI_ERROR_NONE) {
2144       *value_ptr = op.value().l;
2145     }
2146   }
2147   return err;
2148 } /* end GetLocalInstance */
2149 
2150 
2151 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
2152 // depth - pre-checked as non-negative
2153 // value_ptr - pre-checked for null
2154 jvmtiError
2155 JvmtiEnv::GetLocalInt(jthread thread, jint depth, jint slot, jint* value_ptr) {
2156   JavaThread* current_thread = JavaThread::current();
2157   // rm object is created to clean up the javaVFrame created in
2158   // doit_prologue(), but after doit() is finished with it.
2159   ResourceMark rm(current_thread);
2160   HandleMark hm(current_thread);
2161   JvmtiVTMSTransitionDisabler disabler(thread);
2162   ThreadsListHandle tlh(current_thread);
2163 
2164   JavaThread* java_thread = nullptr;
2165   oop thread_obj = nullptr;
2166   jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, current_thread, &java_thread, &thread_obj);
2167   if (err != JVMTI_ERROR_NONE) {
2168     return err;
2169   }
2170   bool self = is_JavaThread_current(java_thread, thread_obj);
2171 
2172   if (java_lang_VirtualThread::is_instance(thread_obj)) {
2173     VM_VirtualThreadGetOrSetLocal op(this, Handle(current_thread, thread_obj),
2174                                      depth, slot, T_INT, self);
2175     VMThread::execute(&op);
2176     err = op.result();
2177     if (err == JVMTI_ERROR_NONE) {
2178       *value_ptr = op.value().i;
2179     }
2180   } else {
2181     // Support for ordinary threads
2182     VM_GetOrSetLocal op(java_thread, depth, slot, T_INT, self);
2183     VMThread::execute(&op);
2184     err = op.result();
2185     if (err == JVMTI_ERROR_NONE) {
2186       *value_ptr = op.value().i;
2187     }
2188   }
2189   return err;
2190 } /* end GetLocalInt */
2191 
2192 
2193 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
2194 // depth - pre-checked as non-negative
2195 // value_ptr - pre-checked for null
2196 jvmtiError
2197 JvmtiEnv::GetLocalLong(jthread thread, jint depth, jint slot, jlong* value_ptr) {
2198   JavaThread* current_thread = JavaThread::current();
2199   // rm object is created to clean up the javaVFrame created in
2200   // doit_prologue(), but after doit() is finished with it.
2201   ResourceMark rm(current_thread);
2202   HandleMark hm(current_thread);
2203   JvmtiVTMSTransitionDisabler disabler(thread);
2204   ThreadsListHandle tlh(current_thread);
2205 
2206   JavaThread* java_thread = nullptr;
2207   oop thread_obj = nullptr;
2208   jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, current_thread, &java_thread, &thread_obj);
2209   if (err != JVMTI_ERROR_NONE) {
2210     return err;
2211   }
2212   bool self = is_JavaThread_current(java_thread, thread_obj);
2213 
2214   if (java_lang_VirtualThread::is_instance(thread_obj)) {
2215     VM_VirtualThreadGetOrSetLocal op(this, Handle(current_thread, thread_obj),
2216                                      depth, slot, T_LONG, self);
2217     VMThread::execute(&op);
2218     err = op.result();
2219     if (err == JVMTI_ERROR_NONE) {
2220       *value_ptr = op.value().j;
2221     }
2222   } else {
2223     // Support for ordinary threads
2224     VM_GetOrSetLocal op(java_thread, depth, slot, T_LONG, self);
2225     VMThread::execute(&op);
2226     err = op.result();
2227     if (err == JVMTI_ERROR_NONE) {
2228       *value_ptr = op.value().j;
2229     }
2230   }
2231   return err;
2232 } /* end GetLocalLong */
2233 
2234 
2235 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
2236 // depth - pre-checked as non-negative
2237 // value_ptr - pre-checked for null
2238 jvmtiError
2239 JvmtiEnv::GetLocalFloat(jthread thread, jint depth, jint slot, jfloat* value_ptr) {
2240   JavaThread* current_thread = JavaThread::current();
2241   // rm object is created to clean up the javaVFrame created in
2242   // doit_prologue(), but after doit() is finished with it.
2243   ResourceMark rm(current_thread);
2244   HandleMark hm(current_thread);
2245   JvmtiVTMSTransitionDisabler disabler(thread);
2246   ThreadsListHandle tlh(current_thread);
2247 
2248   JavaThread* java_thread = nullptr;
2249   oop thread_obj = nullptr;
2250   jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, current_thread, &java_thread, &thread_obj);
2251   if (err != JVMTI_ERROR_NONE) {
2252     return err;
2253   }
2254   bool self = is_JavaThread_current(java_thread, thread_obj);
2255 
2256   if (java_lang_VirtualThread::is_instance(thread_obj)) {
2257     VM_VirtualThreadGetOrSetLocal op(this, Handle(current_thread, thread_obj),
2258                                      depth, slot, T_FLOAT, self);
2259     VMThread::execute(&op);
2260     err = op.result();
2261     if (err == JVMTI_ERROR_NONE) {
2262       *value_ptr = op.value().f;
2263     }
2264   } else {
2265     // Support for ordinary threads
2266     VM_GetOrSetLocal op(java_thread, depth, slot, T_FLOAT, self);
2267     VMThread::execute(&op);
2268     err = op.result();
2269     if (err == JVMTI_ERROR_NONE) {
2270       *value_ptr = op.value().f;
2271     }
2272   }
2273   return err;
2274 } /* end GetLocalFloat */
2275 
2276 
2277 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
2278 // depth - pre-checked as non-negative
2279 // value_ptr - pre-checked for null
2280 jvmtiError
2281 JvmtiEnv::GetLocalDouble(jthread thread, jint depth, jint slot, jdouble* value_ptr) {
2282   JavaThread* current_thread = JavaThread::current();
2283   // rm object is created to clean up the javaVFrame created in
2284   // doit_prologue(), but after doit() is finished with it.
2285   ResourceMark rm(current_thread);
2286   HandleMark hm(current_thread);
2287   JvmtiVTMSTransitionDisabler disabler(thread);
2288   ThreadsListHandle tlh(current_thread);
2289 
2290   JavaThread* java_thread = nullptr;
2291   oop thread_obj = nullptr;
2292   jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, current_thread, &java_thread, &thread_obj);
2293   if (err != JVMTI_ERROR_NONE) {
2294     return err;
2295   }
2296   bool self = is_JavaThread_current(java_thread, thread_obj);
2297 
2298   if (java_lang_VirtualThread::is_instance(thread_obj)) {
2299     VM_VirtualThreadGetOrSetLocal op(this, Handle(current_thread, thread_obj),
2300                                      depth, slot, T_DOUBLE, self);
2301     VMThread::execute(&op);
2302     err = op.result();
2303     if (err == JVMTI_ERROR_NONE) {
2304       *value_ptr = op.value().d;
2305     }
2306   } else {
2307     // Support for ordinary threads
2308     VM_GetOrSetLocal op(java_thread, depth, slot, T_DOUBLE, self);
2309     VMThread::execute(&op);
2310     err = op.result();
2311     if (err == JVMTI_ERROR_NONE) {
2312       *value_ptr = op.value().d;
2313     }
2314   }
2315   return err;
2316 } /* end GetLocalDouble */
2317 
2318 
2319 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
2320 // depth - pre-checked as non-negative
2321 jvmtiError
2322 JvmtiEnv::SetLocalObject(jthread thread, jint depth, jint slot, jobject value) {
2323   JavaThread* current_thread = JavaThread::current();
2324   // rm object is created to clean up the javaVFrame created in
2325   // doit_prologue(), but after doit() is finished with it.
2326   ResourceMark rm(current_thread);
2327   HandleMark hm(current_thread);
2328   JvmtiVTMSTransitionDisabler disabler(thread);
2329   ThreadsListHandle tlh(current_thread);
2330 
2331   JavaThread* java_thread = nullptr;
2332   oop thread_obj = nullptr;
2333   jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, current_thread, &java_thread, &thread_obj);
2334   if (err != JVMTI_ERROR_NONE) {
2335     return err;
2336   }
2337   bool self = is_JavaThread_current(java_thread, thread_obj);
2338   jvalue val;
2339   val.l = value;
2340 
2341   if (java_lang_VirtualThread::is_instance(thread_obj)) {
2342     VM_VirtualThreadGetOrSetLocal op(this, Handle(current_thread, thread_obj),
2343                                      depth, slot, T_OBJECT, val, self);
2344     VMThread::execute(&op);
2345     err = op.result();
2346   } else {
2347     // Support for ordinary threads
2348     VM_GetOrSetLocal op(java_thread, depth, slot, T_OBJECT, val, self);
2349     VMThread::execute(&op);
2350     err = op.result();
2351   }
2352   return err;
2353 } /* end SetLocalObject */
2354 
2355 
2356 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
2357 // depth - pre-checked as non-negative
2358 jvmtiError
2359 JvmtiEnv::SetLocalInt(jthread thread, jint depth, jint slot, jint value) {
2360   JavaThread* current_thread = JavaThread::current();
2361   // rm object is created to clean up the javaVFrame created in
2362   // doit_prologue(), but after doit() is finished with it.
2363   ResourceMark rm(current_thread);
2364   HandleMark hm(current_thread);
2365   JvmtiVTMSTransitionDisabler disabler(thread);
2366   ThreadsListHandle tlh(current_thread);
2367 
2368   JavaThread* java_thread = nullptr;
2369   oop thread_obj = nullptr;
2370   jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, current_thread, &java_thread, &thread_obj);
2371   if (err != JVMTI_ERROR_NONE) {
2372     return err;
2373   }
2374   bool self = is_JavaThread_current(java_thread, thread_obj);
2375   jvalue val;
2376   val.i = value;
2377 
2378   if (java_lang_VirtualThread::is_instance(thread_obj)) {
2379     VM_VirtualThreadGetOrSetLocal op(this, Handle(current_thread, thread_obj),
2380                                      depth, slot, T_INT, val, self);
2381     VMThread::execute(&op);
2382     err = op.result();
2383   } else {
2384     // Support for ordinary threads
2385     VM_GetOrSetLocal op(java_thread, depth, slot, T_INT, val, self);
2386     VMThread::execute(&op);
2387     err = op.result();
2388   }
2389   return err;
2390 } /* end SetLocalInt */
2391 
2392 
2393 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
2394 // depth - pre-checked as non-negative
2395 jvmtiError
2396 JvmtiEnv::SetLocalLong(jthread thread, jint depth, jint slot, jlong value) {
2397   JavaThread* current_thread = JavaThread::current();
2398   // rm object is created to clean up the javaVFrame created in
2399   // doit_prologue(), but after doit() is finished with it.
2400   ResourceMark rm(current_thread);
2401   HandleMark hm(current_thread);
2402   JvmtiVTMSTransitionDisabler disabler(thread);
2403   ThreadsListHandle tlh(current_thread);
2404 
2405   JavaThread* java_thread = nullptr;
2406   oop thread_obj = nullptr;
2407   jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, current_thread, &java_thread, &thread_obj);
2408   if (err != JVMTI_ERROR_NONE) {
2409     return err;
2410   }
2411   bool self = is_JavaThread_current(java_thread, thread_obj);
2412   jvalue val;
2413   val.j = value;
2414 
2415   if (java_lang_VirtualThread::is_instance(thread_obj)) {
2416     VM_VirtualThreadGetOrSetLocal op(this, Handle(current_thread, thread_obj),
2417                                      depth, slot, T_LONG, val, self);
2418     VMThread::execute(&op);
2419     err = op.result();
2420   } else {
2421     // Support for ordinary threads
2422     VM_GetOrSetLocal op(java_thread, depth, slot, T_LONG, val, self);
2423     VMThread::execute(&op);
2424     err = op.result();
2425   }
2426   return err;
2427 } /* end SetLocalLong */
2428 
2429 
2430 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
2431 // depth - pre-checked as non-negative
2432 jvmtiError
2433 JvmtiEnv::SetLocalFloat(jthread thread, jint depth, jint slot, jfloat value) {
2434   JavaThread* current_thread = JavaThread::current();
2435   // rm object is created to clean up the javaVFrame created in
2436   // doit_prologue(), but after doit() is finished with it.
2437   ResourceMark rm(current_thread);
2438   HandleMark hm(current_thread);
2439   JvmtiVTMSTransitionDisabler disabler(thread);
2440   ThreadsListHandle tlh(current_thread);
2441 
2442   JavaThread* java_thread = nullptr;
2443   oop thread_obj = nullptr;
2444   jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, current_thread, &java_thread, &thread_obj);
2445   if (err != JVMTI_ERROR_NONE) {
2446     return err;
2447   }
2448   bool self = is_JavaThread_current(java_thread, thread_obj);
2449   jvalue val;
2450   val.f = value;
2451 
2452   if (java_lang_VirtualThread::is_instance(thread_obj)) {
2453     VM_VirtualThreadGetOrSetLocal op(this, Handle(current_thread, thread_obj),
2454                                      depth, slot, T_FLOAT, val, self);
2455     VMThread::execute(&op);
2456     err = op.result();
2457   } else {
2458     // Support for ordinary threads
2459     VM_GetOrSetLocal op(java_thread, depth, slot, T_FLOAT, val, self);
2460     VMThread::execute(&op);
2461     err = op.result();
2462   }
2463   return err;
2464 } /* end SetLocalFloat */
2465 
2466 
2467 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
2468 // depth - pre-checked as non-negative
2469 jvmtiError
2470 JvmtiEnv::SetLocalDouble(jthread thread, jint depth, jint slot, jdouble value) {
2471   JavaThread* current_thread = JavaThread::current();
2472   // rm object is created to clean up the javaVFrame created in
2473   // doit_prologue(), but after doit() is finished with it.
2474   ResourceMark rm(current_thread);
2475   HandleMark hm(current_thread);
2476   JvmtiVTMSTransitionDisabler disabler(thread);
2477   ThreadsListHandle tlh(current_thread);
2478 
2479   JavaThread* java_thread = nullptr;
2480   oop thread_obj = nullptr;
2481   jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, current_thread, &java_thread, &thread_obj);
2482   if (err != JVMTI_ERROR_NONE) {
2483     return err;
2484   }
2485   bool self = is_JavaThread_current(java_thread, thread_obj);
2486   jvalue val;
2487   val.d = value;
2488 
2489   if (java_lang_VirtualThread::is_instance(thread_obj)) {
2490     VM_VirtualThreadGetOrSetLocal op(this, Handle(current_thread, thread_obj),
2491                                      depth, slot, T_DOUBLE, val, self);
2492     VMThread::execute(&op);
2493     err = op.result();
2494   } else {
2495     // Support for ordinary threads
2496     VM_GetOrSetLocal op(java_thread, depth, slot, T_DOUBLE, val, self);
2497     VMThread::execute(&op);
2498     err = op.result();
2499   }
2500   return err;
2501 } /* end SetLocalDouble */
2502 
2503 
2504   //
2505   // Breakpoint functions
2506   //
2507 
2508 // method - pre-checked for validity, but may be null meaning obsolete method
2509 jvmtiError
2510 JvmtiEnv::SetBreakpoint(Method* method, jlocation location) {
2511   NULL_CHECK(method, JVMTI_ERROR_INVALID_METHODID);
2512   if (location < 0) {   // simple invalid location check first
2513     return JVMTI_ERROR_INVALID_LOCATION;
2514   }
2515   // verify that the breakpoint is not past the end of the method
2516   if (location >= (jlocation) method->code_size()) {
2517     return JVMTI_ERROR_INVALID_LOCATION;
2518   }
2519 
2520   ResourceMark rm;
2521   JvmtiBreakpoint bp(method, location);
2522   JvmtiBreakpoints& jvmti_breakpoints = JvmtiCurrentBreakpoints::get_jvmti_breakpoints();
2523   if (jvmti_breakpoints.set(bp) == JVMTI_ERROR_DUPLICATE)
2524     return JVMTI_ERROR_DUPLICATE;
2525 
2526   if (TraceJVMTICalls) {
2527     jvmti_breakpoints.print();
2528   }
2529 
2530   return JVMTI_ERROR_NONE;
2531 } /* end SetBreakpoint */
2532 
2533 
2534 // method - pre-checked for validity, but may be null meaning obsolete method
2535 jvmtiError
2536 JvmtiEnv::ClearBreakpoint(Method* method, jlocation location) {
2537   NULL_CHECK(method, JVMTI_ERROR_INVALID_METHODID);
2538 
2539   if (location < 0) {   // simple invalid location check first
2540     return JVMTI_ERROR_INVALID_LOCATION;
2541   }
2542 
2543   // verify that the breakpoint is not past the end of the method
2544   if (location >= (jlocation) method->code_size()) {
2545     return JVMTI_ERROR_INVALID_LOCATION;
2546   }
2547 
2548   JvmtiBreakpoint bp(method, location);
2549 
2550   JvmtiBreakpoints& jvmti_breakpoints = JvmtiCurrentBreakpoints::get_jvmti_breakpoints();
2551   if (jvmti_breakpoints.clear(bp) == JVMTI_ERROR_NOT_FOUND)
2552     return JVMTI_ERROR_NOT_FOUND;
2553 
2554   if (TraceJVMTICalls) {
2555     jvmti_breakpoints.print();
2556   }
2557 
2558   return JVMTI_ERROR_NONE;
2559 } /* end ClearBreakpoint */
2560 
2561 
2562   //
2563   // Watched Field functions
2564   //
2565 
2566 jvmtiError
2567 JvmtiEnv::SetFieldAccessWatch(fieldDescriptor* fdesc_ptr) {
2568   JvmtiVTMSTransitionDisabler disabler;
2569   // make sure we haven't set this watch before
2570   if (fdesc_ptr->is_field_access_watched()) return JVMTI_ERROR_DUPLICATE;
2571   fdesc_ptr->set_is_field_access_watched(true);
2572 
2573   JvmtiEventController::change_field_watch(JVMTI_EVENT_FIELD_ACCESS, true);
2574 
2575   return JVMTI_ERROR_NONE;
2576 } /* end SetFieldAccessWatch */
2577 
2578 
2579 jvmtiError
2580 JvmtiEnv::ClearFieldAccessWatch(fieldDescriptor* fdesc_ptr) {
2581   JvmtiVTMSTransitionDisabler disabler;
2582   // make sure we have a watch to clear
2583   if (!fdesc_ptr->is_field_access_watched()) return JVMTI_ERROR_NOT_FOUND;
2584   fdesc_ptr->set_is_field_access_watched(false);
2585 
2586   JvmtiEventController::change_field_watch(JVMTI_EVENT_FIELD_ACCESS, false);
2587 
2588   return JVMTI_ERROR_NONE;
2589 } /* end ClearFieldAccessWatch */
2590 
2591 
2592 jvmtiError
2593 JvmtiEnv::SetFieldModificationWatch(fieldDescriptor* fdesc_ptr) {
2594   JvmtiVTMSTransitionDisabler disabler;
2595   // make sure we haven't set this watch before
2596   if (fdesc_ptr->is_field_modification_watched()) return JVMTI_ERROR_DUPLICATE;
2597   fdesc_ptr->set_is_field_modification_watched(true);
2598 
2599   JvmtiEventController::change_field_watch(JVMTI_EVENT_FIELD_MODIFICATION, true);
2600 
2601   return JVMTI_ERROR_NONE;
2602 } /* end SetFieldModificationWatch */
2603 
2604 
2605 jvmtiError
2606 JvmtiEnv::ClearFieldModificationWatch(fieldDescriptor* fdesc_ptr) {
2607   JvmtiVTMSTransitionDisabler disabler;
2608    // make sure we have a watch to clear
2609   if (!fdesc_ptr->is_field_modification_watched()) return JVMTI_ERROR_NOT_FOUND;
2610   fdesc_ptr->set_is_field_modification_watched(false);
2611 
2612   JvmtiEventController::change_field_watch(JVMTI_EVENT_FIELD_MODIFICATION, false);
2613 
2614   return JVMTI_ERROR_NONE;
2615 } /* end ClearFieldModificationWatch */
2616 
2617   //
2618   // Class functions
2619   //
2620 
2621 
2622 // k_mirror - may be primitive, this must be checked
2623 // signature_ptr - null is a valid value, must be checked
2624 // generic_ptr - null is a valid value, must be checked
2625 jvmtiError
2626 JvmtiEnv::GetClassSignature(oop k_mirror, char** signature_ptr, char** generic_ptr) {
2627   ResourceMark rm;
2628   bool isPrimitive = java_lang_Class::is_primitive(k_mirror);
2629   Klass* k = nullptr;
2630   if (!isPrimitive) {
2631     k = java_lang_Class::as_Klass(k_mirror);
2632     NULL_CHECK(k, JVMTI_ERROR_INVALID_CLASS);
2633   }
2634   if (signature_ptr != nullptr) {
2635     char* result = nullptr;
2636     if (isPrimitive) {
2637       char tchar = type2char(java_lang_Class::primitive_type(k_mirror));
2638       result = (char*) jvmtiMalloc(2);
2639       result[0] = tchar;
2640       result[1] = '\0';
2641     } else {
2642       const char* class_sig = k->signature_name();
2643       result = (char *) jvmtiMalloc(strlen(class_sig)+1);
2644       strcpy(result, class_sig);
2645     }
2646     *signature_ptr = result;
2647   }
2648   if (generic_ptr != nullptr) {
2649     *generic_ptr = nullptr;
2650     if (!isPrimitive && k->is_instance_klass()) {
2651       Symbol* soo = InstanceKlass::cast(k)->generic_signature();
2652       if (soo != nullptr) {
2653         const char *gen_sig = soo->as_C_string();
2654         if (gen_sig != nullptr) {
2655           char* gen_result;
2656           jvmtiError err = allocate(strlen(gen_sig) + 1,
2657                                     (unsigned char **)&gen_result);
2658           if (err != JVMTI_ERROR_NONE) {
2659             return err;
2660           }
2661           strcpy(gen_result, gen_sig);
2662           *generic_ptr = gen_result;
2663         }
2664       }
2665     }
2666   }
2667   return JVMTI_ERROR_NONE;
2668 } /* end GetClassSignature */
2669 
2670 
2671 // k_mirror - may be primitive, this must be checked
2672 // status_ptr - pre-checked for null
2673 jvmtiError
2674 JvmtiEnv::GetClassStatus(oop k_mirror, jint* status_ptr) {
2675   jint result = 0;
2676   if (java_lang_Class::is_primitive(k_mirror)) {
2677     result |= JVMTI_CLASS_STATUS_PRIMITIVE;
2678   } else {
2679     Klass* k = java_lang_Class::as_Klass(k_mirror);
2680     NULL_CHECK(k, JVMTI_ERROR_INVALID_CLASS);
2681     result = k->jvmti_class_status();
2682   }
2683   *status_ptr = result;
2684 
2685   return JVMTI_ERROR_NONE;
2686 } /* end GetClassStatus */
2687 
2688 
2689 // k_mirror - may be primitive, this must be checked
2690 // source_name_ptr - pre-checked for null
2691 jvmtiError
2692 JvmtiEnv::GetSourceFileName(oop k_mirror, char** source_name_ptr) {
2693   if (java_lang_Class::is_primitive(k_mirror)) {
2694      return JVMTI_ERROR_ABSENT_INFORMATION;
2695   }
2696   Klass* k_klass = java_lang_Class::as_Klass(k_mirror);
2697   NULL_CHECK(k_klass, JVMTI_ERROR_INVALID_CLASS);
2698 
2699   if (!k_klass->is_instance_klass()) {
2700     return JVMTI_ERROR_ABSENT_INFORMATION;
2701   }
2702 
2703   Symbol* sfnOop = InstanceKlass::cast(k_klass)->source_file_name();
2704   NULL_CHECK(sfnOop, JVMTI_ERROR_ABSENT_INFORMATION);
2705   {
2706     JavaThread* current_thread  = JavaThread::current();
2707     ResourceMark rm(current_thread);
2708     const char* sfncp = (const char*) sfnOop->as_C_string();
2709     *source_name_ptr = (char *) jvmtiMalloc(strlen(sfncp)+1);
2710     strcpy(*source_name_ptr, sfncp);
2711   }
2712 
2713   return JVMTI_ERROR_NONE;
2714 } /* end GetSourceFileName */
2715 
2716 
2717 // k_mirror - may be primitive, this must be checked
2718 // modifiers_ptr - pre-checked for null
2719 jvmtiError
2720 JvmtiEnv::GetClassModifiers(oop k_mirror, jint* modifiers_ptr) {
2721   jint result = java_lang_Class::modifiers(k_mirror);
2722   *modifiers_ptr = result;
2723 
2724   return JVMTI_ERROR_NONE;
2725 } /* end GetClassModifiers */
2726 
2727 
2728 // k_mirror - may be primitive, this must be checked
2729 // method_count_ptr - pre-checked for null
2730 // methods_ptr - pre-checked for null
2731 jvmtiError
2732 JvmtiEnv::GetClassMethods(oop k_mirror, jint* method_count_ptr, jmethodID** methods_ptr) {
2733   JavaThread* current_thread  = JavaThread::current();
2734   HandleMark hm(current_thread);
2735 
2736   if (java_lang_Class::is_primitive(k_mirror)) {
2737     *method_count_ptr = 0;
2738     *methods_ptr = (jmethodID*) jvmtiMalloc(0 * sizeof(jmethodID));
2739     return JVMTI_ERROR_NONE;
2740   }
2741   Klass* k = java_lang_Class::as_Klass(k_mirror);
2742   NULL_CHECK(k, JVMTI_ERROR_INVALID_CLASS);
2743 
2744   // Return CLASS_NOT_PREPARED error as per JVMTI spec.
2745   if (!(k->jvmti_class_status() & (JVMTI_CLASS_STATUS_PREPARED|JVMTI_CLASS_STATUS_ARRAY) )) {
2746     return JVMTI_ERROR_CLASS_NOT_PREPARED;
2747   }
2748 
2749   if (!k->is_instance_klass()) {
2750     *method_count_ptr = 0;
2751     *methods_ptr = (jmethodID*) jvmtiMalloc(0 * sizeof(jmethodID));
2752     return JVMTI_ERROR_NONE;
2753   }
2754   InstanceKlass* ik = InstanceKlass::cast(k);
2755   // Allocate the result and fill it in
2756   int result_length = ik->methods()->length();
2757   jmethodID* result_list = (jmethodID*)jvmtiMalloc(result_length * sizeof(jmethodID));
2758   int index;
2759   bool jmethodids_found = true;
2760   int skipped = 0;  // skip overpass methods
2761 
2762   for (index = 0; index < result_length; index++) {
2763     Method* m = ik->methods()->at(index);
2764     // Depending on can_maintain_original_method_order capability use the original
2765     // method ordering indices stored in the class, so we can emit jmethodIDs in
2766     // the order they appeared in the class file or just copy in current order.
2767     int result_index = JvmtiExport::can_maintain_original_method_order() ? ik->method_ordering()->at(index) : index;
2768     assert(result_index >= 0 && result_index < result_length, "invalid original method index");
2769     if (m->is_overpass()) {
2770       result_list[result_index] = nullptr;
2771       skipped++;
2772       continue;
2773     }
2774     jmethodID id;
2775     if (jmethodids_found) {
2776       id = m->find_jmethod_id_or_null();
2777       if (id == nullptr) {
2778         // If we find an uninitialized value, make sure there is
2779         // enough space for all the uninitialized values we might
2780         // find.
2781         ik->ensure_space_for_methodids(index);
2782         jmethodids_found = false;
2783         id = m->jmethod_id();
2784       }
2785     } else {
2786       id = m->jmethod_id();
2787     }
2788     result_list[result_index] = id;
2789   }
2790 
2791   // Fill in return value.
2792   if (skipped > 0) {
2793     // copy results skipping null methodIDs
2794     *methods_ptr = (jmethodID*)jvmtiMalloc((result_length - skipped) * sizeof(jmethodID));
2795     *method_count_ptr = result_length - skipped;
2796     for (index = 0, skipped = 0; index < result_length; index++) {
2797       if (result_list[index] == nullptr) {
2798         skipped++;
2799       } else {
2800         (*methods_ptr)[index - skipped] = result_list[index];
2801       }
2802     }
2803     deallocate((unsigned char *)result_list);
2804   } else {
2805     *method_count_ptr = result_length;
2806     *methods_ptr = result_list;
2807   }
2808 
2809   return JVMTI_ERROR_NONE;
2810 } /* end GetClassMethods */
2811 
2812 
2813 // k_mirror - may be primitive, this must be checked
2814 // field_count_ptr - pre-checked for null
2815 // fields_ptr - pre-checked for null
2816 jvmtiError
2817 JvmtiEnv::GetClassFields(oop k_mirror, jint* field_count_ptr, jfieldID** fields_ptr) {
2818   if (java_lang_Class::is_primitive(k_mirror)) {
2819     *field_count_ptr = 0;
2820     *fields_ptr = (jfieldID*) jvmtiMalloc(0 * sizeof(jfieldID));
2821     return JVMTI_ERROR_NONE;
2822   }
2823   JavaThread* current_thread = JavaThread::current();
2824   HandleMark hm(current_thread);
2825   Klass* k = java_lang_Class::as_Klass(k_mirror);
2826   NULL_CHECK(k, JVMTI_ERROR_INVALID_CLASS);
2827 
2828   // Return CLASS_NOT_PREPARED error as per JVMTI spec.
2829   if (!(k->jvmti_class_status() & (JVMTI_CLASS_STATUS_PREPARED|JVMTI_CLASS_STATUS_ARRAY) )) {
2830     return JVMTI_ERROR_CLASS_NOT_PREPARED;
2831   }
2832 
2833   if (!k->is_instance_klass()) {
2834     *field_count_ptr = 0;
2835     *fields_ptr = (jfieldID*) jvmtiMalloc(0 * sizeof(jfieldID));
2836     return JVMTI_ERROR_NONE;
2837   }
2838 
2839   InstanceKlass* ik = InstanceKlass::cast(k);
2840 
2841   FilteredJavaFieldStream flds(ik);
2842 
2843   int result_count = flds.field_count();
2844 
2845   // Allocate the result and fill it in.
2846   jfieldID* result_list = (jfieldID*)jvmtiMalloc(result_count * sizeof(jfieldID));
2847   for (int i = 0; i < result_count; i++, flds.next()) {
2848     result_list[i] = jfieldIDWorkaround::to_jfieldID(ik, flds.offset(),
2849                                                      flds.access_flags().is_static(),
2850                                                      flds.field_descriptor().is_flat());
2851   }
2852   assert(flds.done(), "just checking");
2853 
2854   // Fill in the results
2855   *field_count_ptr = result_count;
2856   *fields_ptr = result_list;
2857 
2858   return JVMTI_ERROR_NONE;
2859 } /* end GetClassFields */
2860 
2861 
2862 // k_mirror - may be primitive, this must be checked
2863 // interface_count_ptr - pre-checked for null
2864 // interfaces_ptr - pre-checked for null
2865 jvmtiError
2866 JvmtiEnv::GetImplementedInterfaces(oop k_mirror, jint* interface_count_ptr, jclass** interfaces_ptr) {
2867   {
2868     if (java_lang_Class::is_primitive(k_mirror)) {
2869       *interface_count_ptr = 0;
2870       *interfaces_ptr = (jclass*) jvmtiMalloc(0 * sizeof(jclass));
2871       return JVMTI_ERROR_NONE;
2872     }
2873     JavaThread* current_thread = JavaThread::current();
2874     HandleMark hm(current_thread);
2875     Klass* k = java_lang_Class::as_Klass(k_mirror);
2876     NULL_CHECK(k, JVMTI_ERROR_INVALID_CLASS);
2877 
2878     // Return CLASS_NOT_PREPARED error as per JVMTI spec.
2879     if (!(k->jvmti_class_status() & (JVMTI_CLASS_STATUS_PREPARED|JVMTI_CLASS_STATUS_ARRAY) ))
2880       return JVMTI_ERROR_CLASS_NOT_PREPARED;
2881 
2882     if (!k->is_instance_klass()) {
2883       *interface_count_ptr = 0;
2884       *interfaces_ptr = (jclass*) jvmtiMalloc(0 * sizeof(jclass));
2885       return JVMTI_ERROR_NONE;
2886     }
2887 
2888     InstanceKlass* ik = InstanceKlass::cast(k);
2889     Array<InstanceKlass*>* interface_list = ik->local_interfaces();
2890     int result_length = (interface_list == nullptr ? 0 : interface_list->length());
2891     jclass* result_list = (jclass*) jvmtiMalloc(result_length * sizeof(jclass));
2892     for (int i_index = 0; i_index < result_length; i_index += 1) {
2893       InstanceKlass* klass_at = interface_list->at(i_index);
2894       assert(klass_at->is_klass(), "interfaces must be Klass*s");
2895       assert(klass_at->is_interface(), "interfaces must be interfaces");
2896       oop mirror_at = klass_at->java_mirror();
2897       Handle handle_at = Handle(current_thread, mirror_at);
2898       result_list[i_index] = (jclass) jni_reference(handle_at);
2899     }
2900     *interface_count_ptr = result_length;
2901     *interfaces_ptr = result_list;
2902   }
2903 
2904   return JVMTI_ERROR_NONE;
2905 } /* end GetImplementedInterfaces */
2906 
2907 
2908 // k_mirror - may be primitive, this must be checked
2909 // minor_version_ptr - pre-checked for null
2910 // major_version_ptr - pre-checked for null
2911 jvmtiError
2912 JvmtiEnv::GetClassVersionNumbers(oop k_mirror, jint* minor_version_ptr, jint* major_version_ptr) {
2913   if (java_lang_Class::is_primitive(k_mirror)) {
2914     return JVMTI_ERROR_ABSENT_INFORMATION;
2915   }
2916   Klass* klass = java_lang_Class::as_Klass(k_mirror);
2917 
2918   jint status = klass->jvmti_class_status();
2919   if (status & (JVMTI_CLASS_STATUS_ERROR)) {
2920     return JVMTI_ERROR_INVALID_CLASS;
2921   }
2922   if (status & (JVMTI_CLASS_STATUS_ARRAY)) {
2923     return JVMTI_ERROR_ABSENT_INFORMATION;
2924   }
2925 
2926   InstanceKlass* ik = InstanceKlass::cast(klass);
2927   *minor_version_ptr = ik->minor_version();
2928   *major_version_ptr = ik->major_version();
2929 
2930   return JVMTI_ERROR_NONE;
2931 } /* end GetClassVersionNumbers */
2932 
2933 
2934 // k_mirror - may be primitive, this must be checked
2935 // constant_pool_count_ptr - pre-checked for null
2936 // constant_pool_byte_count_ptr - pre-checked for null
2937 // constant_pool_bytes_ptr - pre-checked for null
2938 jvmtiError
2939 JvmtiEnv::GetConstantPool(oop k_mirror, jint* constant_pool_count_ptr, jint* constant_pool_byte_count_ptr, unsigned char** constant_pool_bytes_ptr) {
2940   if (java_lang_Class::is_primitive(k_mirror)) {
2941     return JVMTI_ERROR_ABSENT_INFORMATION;
2942   }
2943 
2944   Klass* klass = java_lang_Class::as_Klass(k_mirror);
2945   Thread *thread = Thread::current();
2946   ResourceMark rm(thread);
2947 
2948   jint status = klass->jvmti_class_status();
2949   if (status & (JVMTI_CLASS_STATUS_ERROR)) {
2950     return JVMTI_ERROR_INVALID_CLASS;
2951   }
2952   if (status & (JVMTI_CLASS_STATUS_ARRAY)) {
2953     return JVMTI_ERROR_ABSENT_INFORMATION;
2954   }
2955 
2956   InstanceKlass* ik = InstanceKlass::cast(klass);
2957   JvmtiConstantPoolReconstituter reconstituter(ik);
2958   if (reconstituter.get_error() != JVMTI_ERROR_NONE) {
2959     return reconstituter.get_error();
2960   }
2961 
2962   unsigned char *cpool_bytes;
2963   int cpool_size = reconstituter.cpool_size();
2964   if (reconstituter.get_error() != JVMTI_ERROR_NONE) {
2965     return reconstituter.get_error();
2966   }
2967   jvmtiError res = allocate(cpool_size, &cpool_bytes);
2968   if (res != JVMTI_ERROR_NONE) {
2969     return res;
2970   }
2971   reconstituter.copy_cpool_bytes(cpool_bytes);
2972   if (reconstituter.get_error() != JVMTI_ERROR_NONE) {
2973     return reconstituter.get_error();
2974   }
2975 
2976   constantPoolHandle  constants(thread, ik->constants());
2977   *constant_pool_count_ptr      = constants->length();
2978   *constant_pool_byte_count_ptr = cpool_size;
2979   *constant_pool_bytes_ptr      = cpool_bytes;
2980 
2981   return JVMTI_ERROR_NONE;
2982 } /* end GetConstantPool */
2983 
2984 
2985 // k_mirror - may be primitive, this must be checked
2986 // is_interface_ptr - pre-checked for null
2987 jvmtiError
2988 JvmtiEnv::IsInterface(oop k_mirror, jboolean* is_interface_ptr) {
2989   {
2990     bool result = false;
2991     if (!java_lang_Class::is_primitive(k_mirror)) {
2992       Klass* k = java_lang_Class::as_Klass(k_mirror);
2993       if (k != nullptr && k->is_interface()) {
2994         result = true;
2995       }
2996     }
2997     *is_interface_ptr = result;
2998   }
2999 
3000   return JVMTI_ERROR_NONE;
3001 } /* end IsInterface */
3002 
3003 
3004 // k_mirror - may be primitive, this must be checked
3005 // is_array_class_ptr - pre-checked for null
3006 jvmtiError
3007 JvmtiEnv::IsArrayClass(oop k_mirror, jboolean* is_array_class_ptr) {
3008   {
3009     bool result = false;
3010     if (!java_lang_Class::is_primitive(k_mirror)) {
3011       Klass* k = java_lang_Class::as_Klass(k_mirror);
3012       if (k != nullptr && k->is_array_klass()) {
3013         result = true;
3014       }
3015     }
3016     *is_array_class_ptr = result;
3017   }
3018 
3019   return JVMTI_ERROR_NONE;
3020 } /* end IsArrayClass */
3021 
3022 
3023 // k_mirror - may be primitive, this must be checked
3024 // classloader_ptr - pre-checked for null
3025 jvmtiError
3026 JvmtiEnv::GetClassLoader(oop k_mirror, jobject* classloader_ptr) {
3027   {
3028     if (java_lang_Class::is_primitive(k_mirror)) {
3029       *classloader_ptr = (jclass) jni_reference(Handle());
3030       return JVMTI_ERROR_NONE;
3031     }
3032     JavaThread* current_thread = JavaThread::current();
3033     HandleMark hm(current_thread);
3034     Klass* k = java_lang_Class::as_Klass(k_mirror);
3035     NULL_CHECK(k, JVMTI_ERROR_INVALID_CLASS);
3036 
3037     oop result_oop = k->class_loader();
3038     if (result_oop == nullptr) {
3039       *classloader_ptr = (jclass) jni_reference(Handle());
3040       return JVMTI_ERROR_NONE;
3041     }
3042     Handle result_handle = Handle(current_thread, result_oop);
3043     jclass result_jnihandle = (jclass) jni_reference(result_handle);
3044     *classloader_ptr = result_jnihandle;
3045   }
3046   return JVMTI_ERROR_NONE;
3047 } /* end GetClassLoader */
3048 
3049 
3050 // k_mirror - may be primitive, this must be checked
3051 // source_debug_extension_ptr - pre-checked for null
3052 jvmtiError
3053 JvmtiEnv::GetSourceDebugExtension(oop k_mirror, char** source_debug_extension_ptr) {
3054   {
3055     if (java_lang_Class::is_primitive(k_mirror)) {
3056       return JVMTI_ERROR_ABSENT_INFORMATION;
3057     }
3058     Klass* k = java_lang_Class::as_Klass(k_mirror);
3059     NULL_CHECK(k, JVMTI_ERROR_INVALID_CLASS);
3060     if (!k->is_instance_klass()) {
3061       return JVMTI_ERROR_ABSENT_INFORMATION;
3062     }
3063     const char* sde = InstanceKlass::cast(k)->source_debug_extension();
3064     NULL_CHECK(sde, JVMTI_ERROR_ABSENT_INFORMATION);
3065 
3066     {
3067       *source_debug_extension_ptr = (char *) jvmtiMalloc(strlen(sde)+1);
3068       strcpy(*source_debug_extension_ptr, sde);
3069     }
3070   }
3071 
3072   return JVMTI_ERROR_NONE;
3073 } /* end GetSourceDebugExtension */
3074 
3075   //
3076   // Object functions
3077   //
3078 
3079 // hash_code_ptr - pre-checked for null
3080 jvmtiError
3081 JvmtiEnv::GetObjectHashCode(jobject object, jint* hash_code_ptr) {
3082   oop mirror = JNIHandles::resolve_external_guard(object);
3083   NULL_CHECK(mirror, JVMTI_ERROR_INVALID_OBJECT);
3084   NULL_CHECK(hash_code_ptr, JVMTI_ERROR_NULL_POINTER);
3085 
3086   if (mirror->is_inline_type()) {
3087     // For inline types, use the klass as a hash code.
3088     // TBD to improve this (see also JvmtiTagMapKey::get_hash for similar case).
3089     *hash_code_ptr = (jint)((int64_t)mirror->klass() >> 3);
3090   } else {
3091     *hash_code_ptr = (jint)mirror->identity_hash();
3092   }
3093   return JVMTI_ERROR_NONE;
3094 } /* end GetObjectHashCode */
3095 
3096 
3097 // info_ptr - pre-checked for null
3098 jvmtiError
3099 JvmtiEnv::GetObjectMonitorUsage(jobject object, jvmtiMonitorUsage* info_ptr) {
3100   // This needs to be performed at a safepoint to gather stable data
3101   // because monitor owner / waiters might not be suspended.
3102   VM_GetObjectMonitorUsage op(this, JavaThread::current(), object, info_ptr);
3103   VMThread::execute(&op);
3104   return op.result();
3105 } /* end GetObjectMonitorUsage */
3106 
3107 
3108   //
3109   // Field functions
3110   //
3111 
3112 // name_ptr - null is a valid value, must be checked
3113 // signature_ptr - null is a valid value, must be checked
3114 // generic_ptr - null is a valid value, must be checked
3115 jvmtiError
3116 JvmtiEnv::GetFieldName(fieldDescriptor* fdesc_ptr, char** name_ptr, char** signature_ptr, char** generic_ptr) {
3117   JavaThread* current_thread  = JavaThread::current();
3118   ResourceMark rm(current_thread);
3119   if (name_ptr == nullptr) {
3120     // just don't return the name
3121   } else {
3122     const char* fieldName = fdesc_ptr->name()->as_C_string();
3123     *name_ptr =  (char*) jvmtiMalloc(strlen(fieldName) + 1);
3124     if (*name_ptr == nullptr)
3125       return JVMTI_ERROR_OUT_OF_MEMORY;
3126     strcpy(*name_ptr, fieldName);
3127   }
3128   if (signature_ptr== nullptr) {
3129     // just don't return the signature
3130   } else {
3131     const char* fieldSignature = fdesc_ptr->signature()->as_C_string();
3132     *signature_ptr = (char*) jvmtiMalloc(strlen(fieldSignature) + 1);
3133     if (*signature_ptr == nullptr)
3134       return JVMTI_ERROR_OUT_OF_MEMORY;
3135     strcpy(*signature_ptr, fieldSignature);
3136   }
3137   if (generic_ptr != nullptr) {
3138     *generic_ptr = nullptr;
3139     Symbol* soop = fdesc_ptr->generic_signature();
3140     if (soop != nullptr) {
3141       const char* gen_sig = soop->as_C_string();
3142       if (gen_sig != nullptr) {
3143         jvmtiError err = allocate(strlen(gen_sig) + 1, (unsigned char **)generic_ptr);
3144         if (err != JVMTI_ERROR_NONE) {
3145           return err;
3146         }
3147         strcpy(*generic_ptr, gen_sig);
3148       }
3149     }
3150   }
3151   return JVMTI_ERROR_NONE;
3152 } /* end GetFieldName */
3153 
3154 
3155 // declaring_class_ptr - pre-checked for null
3156 jvmtiError
3157 JvmtiEnv::GetFieldDeclaringClass(fieldDescriptor* fdesc_ptr, jclass* declaring_class_ptr) {
3158   // As for the GetFieldDeclaringClass method, the XSL generated C++ code that calls it has
3159   // a jclass of the relevant class or a subclass of it, which is fine in terms of ensuring
3160   // the holder is kept alive.
3161   *declaring_class_ptr = get_jni_class_non_null(fdesc_ptr->field_holder());
3162   return JVMTI_ERROR_NONE;
3163 } /* end GetFieldDeclaringClass */
3164 
3165 
3166 // modifiers_ptr - pre-checked for null
3167 jvmtiError
3168 JvmtiEnv::GetFieldModifiers(fieldDescriptor* fdesc_ptr, jint* modifiers_ptr) {
3169 
3170   AccessFlags resultFlags = fdesc_ptr->access_flags();
3171   jint result = resultFlags.as_field_flags();
3172   *modifiers_ptr = result;
3173 
3174   return JVMTI_ERROR_NONE;
3175 } /* end GetFieldModifiers */
3176 
3177 
3178 // is_synthetic_ptr - pre-checked for null
3179 jvmtiError
3180 JvmtiEnv::IsFieldSynthetic(fieldDescriptor* fdesc_ptr, jboolean* is_synthetic_ptr) {
3181   *is_synthetic_ptr = fdesc_ptr->is_synthetic();
3182   return JVMTI_ERROR_NONE;
3183 } /* end IsFieldSynthetic */
3184 
3185 
3186   //
3187   // Method functions
3188   //
3189 
3190 // method - pre-checked for validity, but may be null meaning obsolete method
3191 // name_ptr - null is a valid value, must be checked
3192 // signature_ptr - null is a valid value, must be checked
3193 // generic_ptr - null is a valid value, must be checked
3194 jvmtiError
3195 JvmtiEnv::GetMethodName(Method* method, char** name_ptr, char** signature_ptr, char** generic_ptr) {
3196   NULL_CHECK(method, JVMTI_ERROR_INVALID_METHODID);
3197   JavaThread* current_thread  = JavaThread::current();
3198 
3199   ResourceMark rm(current_thread); // get the utf8 name and signature
3200   if (name_ptr == nullptr) {
3201     // just don't return the name
3202   } else {
3203     const char* utf8_name = (const char *) method->name()->as_utf8();
3204     *name_ptr = (char *) jvmtiMalloc(strlen(utf8_name)+1);
3205     strcpy(*name_ptr, utf8_name);
3206   }
3207   if (signature_ptr == nullptr) {
3208     // just don't return the signature
3209   } else {
3210     const char* utf8_signature = (const char *) method->signature()->as_utf8();
3211     *signature_ptr = (char *) jvmtiMalloc(strlen(utf8_signature) + 1);
3212     strcpy(*signature_ptr, utf8_signature);
3213   }
3214 
3215   if (generic_ptr != nullptr) {
3216     *generic_ptr = nullptr;
3217     Symbol* soop = method->generic_signature();
3218     if (soop != nullptr) {
3219       const char* gen_sig = soop->as_C_string();
3220       if (gen_sig != nullptr) {
3221         jvmtiError err = allocate(strlen(gen_sig) + 1, (unsigned char **)generic_ptr);
3222         if (err != JVMTI_ERROR_NONE) {
3223           return err;
3224         }
3225         strcpy(*generic_ptr, gen_sig);
3226       }
3227     }
3228   }
3229   return JVMTI_ERROR_NONE;
3230 } /* end GetMethodName */
3231 
3232 
3233 // method - pre-checked for validity, but may be null meaning obsolete method
3234 // declaring_class_ptr - pre-checked for null
3235 jvmtiError
3236 JvmtiEnv::GetMethodDeclaringClass(Method* method, jclass* declaring_class_ptr) {
3237   NULL_CHECK(method, JVMTI_ERROR_INVALID_METHODID);
3238   Klass* k = method->method_holder();
3239   Handle holder(Thread::current(), k->klass_holder()); // keep the klass alive
3240   (*declaring_class_ptr) = get_jni_class_non_null(k);
3241   return JVMTI_ERROR_NONE;
3242 } /* end GetMethodDeclaringClass */
3243 
3244 
3245 // method - pre-checked for validity, but may be null meaning obsolete method
3246 // modifiers_ptr - pre-checked for null
3247 jvmtiError
3248 JvmtiEnv::GetMethodModifiers(Method* method, jint* modifiers_ptr) {
3249   NULL_CHECK(method, JVMTI_ERROR_INVALID_METHODID);
3250   (*modifiers_ptr) = method->access_flags().as_method_flags();
3251   return JVMTI_ERROR_NONE;
3252 } /* end GetMethodModifiers */
3253 
3254 
3255 // method - pre-checked for validity, but may be null meaning obsolete method
3256 // max_ptr - pre-checked for null
3257 jvmtiError
3258 JvmtiEnv::GetMaxLocals(Method* method, jint* max_ptr) {
3259   NULL_CHECK(method, JVMTI_ERROR_INVALID_METHODID);
3260   // get max stack
3261   (*max_ptr) = method->max_locals();
3262   return JVMTI_ERROR_NONE;
3263 } /* end GetMaxLocals */
3264 
3265 
3266 // method - pre-checked for validity, but may be null meaning obsolete method
3267 // size_ptr - pre-checked for null
3268 jvmtiError
3269 JvmtiEnv::GetArgumentsSize(Method* method, jint* size_ptr) {
3270   NULL_CHECK(method, JVMTI_ERROR_INVALID_METHODID);
3271   // get size of arguments
3272 
3273   (*size_ptr) = method->size_of_parameters();
3274   return JVMTI_ERROR_NONE;
3275 } /* end GetArgumentsSize */
3276 
3277 
3278 // method - pre-checked for validity, but may be null meaning obsolete method
3279 // entry_count_ptr - pre-checked for null
3280 // table_ptr - pre-checked for null
3281 jvmtiError
3282 JvmtiEnv::GetLineNumberTable(Method* method, jint* entry_count_ptr, jvmtiLineNumberEntry** table_ptr) {
3283   NULL_CHECK(method, JVMTI_ERROR_INVALID_METHODID);
3284   if (!method->has_linenumber_table()) {
3285     return (JVMTI_ERROR_ABSENT_INFORMATION);
3286   }
3287 
3288   // The line number table is compressed so we don't know how big it is until decompressed.
3289   // Decompression is really fast so we just do it twice.
3290 
3291   // Compute size of table
3292   jint num_entries = 0;
3293   CompressedLineNumberReadStream stream(method->compressed_linenumber_table());
3294   while (stream.read_pair()) {
3295     num_entries++;
3296   }
3297   jvmtiLineNumberEntry *jvmti_table =
3298             (jvmtiLineNumberEntry *)jvmtiMalloc(num_entries * (sizeof(jvmtiLineNumberEntry)));
3299 
3300   // Fill jvmti table
3301   if (num_entries > 0) {
3302     int index = 0;
3303     CompressedLineNumberReadStream stream(method->compressed_linenumber_table());
3304     while (stream.read_pair()) {
3305       jvmti_table[index].start_location = (jlocation) stream.bci();
3306       jvmti_table[index].line_number = (jint) stream.line();
3307       index++;
3308     }
3309     assert(index == num_entries, "sanity check");
3310   }
3311 
3312   // Set up results
3313   (*entry_count_ptr) = num_entries;
3314   (*table_ptr) = jvmti_table;
3315 
3316   return JVMTI_ERROR_NONE;
3317 } /* end GetLineNumberTable */
3318 
3319 
3320 // method - pre-checked for validity, but may be null meaning obsolete method
3321 // start_location_ptr - pre-checked for null
3322 // end_location_ptr - pre-checked for null
3323 jvmtiError
3324 JvmtiEnv::GetMethodLocation(Method* method, jlocation* start_location_ptr, jlocation* end_location_ptr) {
3325 
3326   NULL_CHECK(method, JVMTI_ERROR_INVALID_METHODID);
3327   // get start and end location
3328   (*end_location_ptr) = (jlocation) (method->code_size() - 1);
3329   if (method->code_size() == 0) {
3330     // there is no code so there is no start location
3331     (*start_location_ptr) = (jlocation)(-1);
3332   } else {
3333     (*start_location_ptr) = (jlocation)(0);
3334   }
3335 
3336   return JVMTI_ERROR_NONE;
3337 } /* end GetMethodLocation */
3338 
3339 
3340 // method - pre-checked for validity, but may be null meaning obsolete method
3341 // entry_count_ptr - pre-checked for null
3342 // table_ptr - pre-checked for null
3343 jvmtiError
3344 JvmtiEnv::GetLocalVariableTable(Method* method, jint* entry_count_ptr, jvmtiLocalVariableEntry** table_ptr) {
3345 
3346   NULL_CHECK(method, JVMTI_ERROR_INVALID_METHODID);
3347   JavaThread* current_thread  = JavaThread::current();
3348 
3349   // does the klass have any local variable information?
3350   InstanceKlass* ik = method->method_holder();
3351   if (!ik->has_localvariable_table()) {
3352     return (JVMTI_ERROR_ABSENT_INFORMATION);
3353   }
3354 
3355   ConstantPool* constants = method->constants();
3356   NULL_CHECK(constants, JVMTI_ERROR_ABSENT_INFORMATION);
3357 
3358   // in the vm localvariable table representation, 6 consecutive elements in the table
3359   // represent a 6-tuple of shorts
3360   // [start_pc, length, name_index, descriptor_index, signature_index, index]
3361   jint num_entries = method->localvariable_table_length();
3362   jvmtiLocalVariableEntry *jvmti_table = (jvmtiLocalVariableEntry *)
3363                 jvmtiMalloc(num_entries * (sizeof(jvmtiLocalVariableEntry)));
3364 
3365   if (num_entries > 0) {
3366     LocalVariableTableElement* table = method->localvariable_table_start();
3367     for (int i = 0; i < num_entries; i++) {
3368       // get the 5 tuple information from the vm table
3369       jlocation start_location = (jlocation) table[i].start_bci;
3370       jint length = (jint) table[i].length;
3371       int name_index = (int) table[i].name_cp_index;
3372       int signature_index = (int) table[i].descriptor_cp_index;
3373       int generic_signature_index = (int) table[i].signature_cp_index;
3374       jint slot = (jint) table[i].slot;
3375 
3376       // get utf8 name and signature
3377       char *name_buf = nullptr;
3378       char *sig_buf = nullptr;
3379       char *gen_sig_buf = nullptr;
3380       {
3381         ResourceMark rm(current_thread);
3382 
3383         const char *utf8_name = (const char *) constants->symbol_at(name_index)->as_utf8();
3384         name_buf = (char *) jvmtiMalloc(strlen(utf8_name)+1);
3385         strcpy(name_buf, utf8_name);
3386 
3387         const char *utf8_signature = (const char *) constants->symbol_at(signature_index)->as_utf8();
3388         sig_buf = (char *) jvmtiMalloc(strlen(utf8_signature)+1);
3389         strcpy(sig_buf, utf8_signature);
3390 
3391         if (generic_signature_index > 0) {
3392           const char *utf8_gen_sign = (const char *)
3393                                        constants->symbol_at(generic_signature_index)->as_utf8();
3394           gen_sig_buf = (char *) jvmtiMalloc(strlen(utf8_gen_sign)+1);
3395           strcpy(gen_sig_buf, utf8_gen_sign);
3396         }
3397       }
3398 
3399       // fill in the jvmti local variable table
3400       jvmti_table[i].start_location = start_location;
3401       jvmti_table[i].length = length;
3402       jvmti_table[i].name = name_buf;
3403       jvmti_table[i].signature = sig_buf;
3404       jvmti_table[i].generic_signature = gen_sig_buf;
3405       jvmti_table[i].slot = slot;
3406     }
3407   }
3408 
3409   // set results
3410   (*entry_count_ptr) = num_entries;
3411   (*table_ptr) = jvmti_table;
3412 
3413   return JVMTI_ERROR_NONE;
3414 } /* end GetLocalVariableTable */
3415 
3416 
3417 // method - pre-checked for validity, but may be null meaning obsolete method
3418 // bytecode_count_ptr - pre-checked for null
3419 // bytecodes_ptr - pre-checked for null
3420 jvmtiError
3421 JvmtiEnv::GetBytecodes(Method* method, jint* bytecode_count_ptr, unsigned char** bytecodes_ptr) {
3422   NULL_CHECK(method, JVMTI_ERROR_INVALID_METHODID);
3423 
3424   methodHandle mh(Thread::current(), method);
3425   jint size = (jint)mh->code_size();
3426   jvmtiError err = allocate(size, bytecodes_ptr);
3427   if (err != JVMTI_ERROR_NONE) {
3428     return err;
3429   }
3430 
3431   (*bytecode_count_ptr) = size;
3432   // get byte codes
3433   JvmtiClassFileReconstituter::copy_bytecodes(mh, *bytecodes_ptr);
3434 
3435   return JVMTI_ERROR_NONE;
3436 } /* end GetBytecodes */
3437 
3438 
3439 // method - pre-checked for validity, but may be null meaning obsolete method
3440 // is_native_ptr - pre-checked for null
3441 jvmtiError
3442 JvmtiEnv::IsMethodNative(Method* method, jboolean* is_native_ptr) {
3443   NULL_CHECK(method, JVMTI_ERROR_INVALID_METHODID);
3444   (*is_native_ptr) = method->is_native();
3445   return JVMTI_ERROR_NONE;
3446 } /* end IsMethodNative */
3447 
3448 
3449 // method - pre-checked for validity, but may be null meaning obsolete method
3450 // is_synthetic_ptr - pre-checked for null
3451 jvmtiError
3452 JvmtiEnv::IsMethodSynthetic(Method* method, jboolean* is_synthetic_ptr) {
3453   NULL_CHECK(method, JVMTI_ERROR_INVALID_METHODID);
3454   (*is_synthetic_ptr) = method->is_synthetic();
3455   return JVMTI_ERROR_NONE;
3456 } /* end IsMethodSynthetic */
3457 
3458 
3459 // method - pre-checked for validity, but may be null meaning obsolete method
3460 // is_obsolete_ptr - pre-checked for null
3461 jvmtiError
3462 JvmtiEnv::IsMethodObsolete(Method* method, jboolean* is_obsolete_ptr) {
3463   if (use_version_1_0_semantics() &&
3464       get_capabilities()->can_redefine_classes == 0) {
3465     // This JvmtiEnv requested version 1.0 semantics and this function
3466     // requires the can_redefine_classes capability in version 1.0 so
3467     // we need to return an error here.
3468     return JVMTI_ERROR_MUST_POSSESS_CAPABILITY;
3469   }
3470 
3471   if (method == nullptr || method->is_obsolete()) {
3472     *is_obsolete_ptr = true;
3473   } else {
3474     *is_obsolete_ptr = false;
3475   }
3476   return JVMTI_ERROR_NONE;
3477 } /* end IsMethodObsolete */
3478 
3479   //
3480   // Raw Monitor functions
3481   //
3482 
3483 // name - pre-checked for null
3484 // monitor_ptr - pre-checked for null
3485 jvmtiError
3486 JvmtiEnv::CreateRawMonitor(const char* name, jrawMonitorID* monitor_ptr) {
3487   JvmtiRawMonitor* rmonitor = new (std::nothrow) JvmtiRawMonitor(name);
3488   NULL_CHECK(rmonitor, JVMTI_ERROR_OUT_OF_MEMORY);
3489 
3490   *monitor_ptr = (jrawMonitorID)rmonitor;
3491 
3492   return JVMTI_ERROR_NONE;
3493 } /* end CreateRawMonitor */
3494 
3495 
3496 // rmonitor - pre-checked for validity
3497 jvmtiError
3498 JvmtiEnv::DestroyRawMonitor(JvmtiRawMonitor * rmonitor) {
3499   if (Threads::number_of_threads() == 0) {
3500     // Remove this monitor from pending raw monitors list
3501     // if it has entered in onload or start phase.
3502     JvmtiPendingMonitors::destroy(rmonitor);
3503   } else {
3504     Thread* thread  = Thread::current();
3505     if (rmonitor->owner() == thread) {
3506       // The caller owns this monitor which we are about to destroy.
3507       // We exit the underlying synchronization object so that the
3508       // "delete monitor" call below can work without an assertion
3509       // failure on systems that don't like destroying synchronization
3510       // objects that are locked.
3511       int r;
3512       int recursion = rmonitor->recursions();
3513       for (int i = 0; i <= recursion; i++) {
3514         r = rmonitor->raw_exit(thread);
3515         assert(r == JvmtiRawMonitor::M_OK, "raw_exit should have worked");
3516         if (r != JvmtiRawMonitor::M_OK) {  // robustness
3517           return JVMTI_ERROR_INTERNAL;
3518         }
3519       }
3520     }
3521     if (rmonitor->owner() != nullptr) {
3522       // The caller is trying to destroy a monitor that is locked by
3523       // someone else. While this is not forbidden by the JVMTI
3524       // spec, it will cause an assertion failure on systems that don't
3525       // like destroying synchronization objects that are locked.
3526       // We indicate a problem with the error return (and leak the
3527       // monitor's memory).
3528       return JVMTI_ERROR_NOT_MONITOR_OWNER;
3529     }
3530   }
3531 
3532   delete rmonitor;
3533 
3534   return JVMTI_ERROR_NONE;
3535 } /* end DestroyRawMonitor */
3536 
3537 
3538 // rmonitor - pre-checked for validity
3539 jvmtiError
3540 JvmtiEnv::RawMonitorEnter(JvmtiRawMonitor * rmonitor) {
3541   if (Threads::number_of_threads() == 0) {
3542     // No JavaThreads exist so JvmtiRawMonitor enter cannot be
3543     // used, add this raw monitor to the pending list.
3544     // The pending monitors will be actually entered when
3545     // the VM is setup.
3546     // See transition_pending_raw_monitors in create_vm()
3547     // in thread.cpp.
3548     JvmtiPendingMonitors::enter(rmonitor);
3549   } else {
3550     Thread* thread = Thread::current();
3551     // 8266889: raw_enter changes Java thread state, needs WXWrite
3552     MACOS_AARCH64_ONLY(ThreadWXEnable __wx(WXWrite, thread));
3553     rmonitor->raw_enter(thread);
3554   }
3555   return JVMTI_ERROR_NONE;
3556 } /* end RawMonitorEnter */
3557 
3558 
3559 // rmonitor - pre-checked for validity
3560 jvmtiError
3561 JvmtiEnv::RawMonitorExit(JvmtiRawMonitor * rmonitor) {
3562   jvmtiError err = JVMTI_ERROR_NONE;
3563 
3564   if (Threads::number_of_threads() == 0) {
3565     // No JavaThreads exist so just remove this monitor from the pending list.
3566     // Bool value from exit is false if rmonitor is not in the list.
3567     if (!JvmtiPendingMonitors::exit(rmonitor)) {
3568       err = JVMTI_ERROR_NOT_MONITOR_OWNER;
3569     }
3570   } else {
3571     Thread* thread = Thread::current();
3572     int r = rmonitor->raw_exit(thread);
3573     if (r == JvmtiRawMonitor::M_ILLEGAL_MONITOR_STATE) {
3574       err = JVMTI_ERROR_NOT_MONITOR_OWNER;
3575     }
3576   }
3577   return err;
3578 } /* end RawMonitorExit */
3579 
3580 
3581 // rmonitor - pre-checked for validity
3582 jvmtiError
3583 JvmtiEnv::RawMonitorWait(JvmtiRawMonitor * rmonitor, jlong millis) {
3584   Thread* thread = Thread::current();
3585   // 8266889: raw_wait changes Java thread state, needs WXWrite
3586   MACOS_AARCH64_ONLY(ThreadWXEnable __wx(WXWrite, thread));
3587   int r = rmonitor->raw_wait(millis, thread);
3588 
3589   switch (r) {
3590   case JvmtiRawMonitor::M_INTERRUPTED:
3591     return JVMTI_ERROR_INTERRUPT;
3592   case JvmtiRawMonitor::M_ILLEGAL_MONITOR_STATE:
3593     return JVMTI_ERROR_NOT_MONITOR_OWNER;
3594   default:
3595     return JVMTI_ERROR_NONE;
3596   }
3597 } /* end RawMonitorWait */
3598 
3599 
3600 // rmonitor - pre-checked for validity
3601 jvmtiError
3602 JvmtiEnv::RawMonitorNotify(JvmtiRawMonitor * rmonitor) {
3603   Thread* thread = Thread::current();
3604   int r = rmonitor->raw_notify(thread);
3605 
3606   if (r == JvmtiRawMonitor::M_ILLEGAL_MONITOR_STATE) {
3607     return JVMTI_ERROR_NOT_MONITOR_OWNER;
3608   }
3609   return JVMTI_ERROR_NONE;
3610 } /* end RawMonitorNotify */
3611 
3612 
3613 // rmonitor - pre-checked for validity
3614 jvmtiError
3615 JvmtiEnv::RawMonitorNotifyAll(JvmtiRawMonitor * rmonitor) {
3616   Thread* thread = Thread::current();
3617   int r = rmonitor->raw_notifyAll(thread);
3618 
3619   if (r == JvmtiRawMonitor::M_ILLEGAL_MONITOR_STATE) {
3620     return JVMTI_ERROR_NOT_MONITOR_OWNER;
3621   }
3622   return JVMTI_ERROR_NONE;
3623 } /* end RawMonitorNotifyAll */
3624 
3625 
3626   //
3627   // JNI Function Interception functions
3628   //
3629 
3630 
3631 // function_table - pre-checked for null
3632 jvmtiError
3633 JvmtiEnv::SetJNIFunctionTable(const jniNativeInterface* function_table) {
3634   // Copy jni function table at safepoint.
3635   VM_JNIFunctionTableCopier copier(function_table);
3636   VMThread::execute(&copier);
3637 
3638   return JVMTI_ERROR_NONE;
3639 } /* end SetJNIFunctionTable */
3640 
3641 
3642 // function_table - pre-checked for null
3643 jvmtiError
3644 JvmtiEnv::GetJNIFunctionTable(jniNativeInterface** function_table) {
3645   *function_table=(jniNativeInterface*)jvmtiMalloc(sizeof(jniNativeInterface));
3646   if (*function_table == nullptr)
3647     return JVMTI_ERROR_OUT_OF_MEMORY;
3648   memcpy(*function_table,(JavaThread::current())->get_jni_functions(),sizeof(jniNativeInterface));
3649   return JVMTI_ERROR_NONE;
3650 } /* end GetJNIFunctionTable */
3651 
3652 
3653   //
3654   // Event Management functions
3655   //
3656 
3657 jvmtiError
3658 JvmtiEnv::GenerateEvents(jvmtiEvent event_type) {
3659   // can only generate two event types
3660   if (event_type != JVMTI_EVENT_COMPILED_METHOD_LOAD &&
3661       event_type != JVMTI_EVENT_DYNAMIC_CODE_GENERATED) {
3662     return JVMTI_ERROR_ILLEGAL_ARGUMENT;
3663   }
3664 
3665   // for compiled_method_load events we must check that the environment
3666   // has the can_generate_compiled_method_load_events capability.
3667   if (event_type == JVMTI_EVENT_COMPILED_METHOD_LOAD) {
3668     if (get_capabilities()->can_generate_compiled_method_load_events == 0) {
3669       return JVMTI_ERROR_MUST_POSSESS_CAPABILITY;
3670     }
3671     return JvmtiCodeBlobEvents::generate_compiled_method_load_events(this);
3672   } else {
3673     return JvmtiCodeBlobEvents::generate_dynamic_code_events(this);
3674   }
3675 
3676 } /* end GenerateEvents */
3677 
3678 
3679   //
3680   // Extension Mechanism functions
3681   //
3682 
3683 // extension_count_ptr - pre-checked for null
3684 // extensions - pre-checked for null
3685 jvmtiError
3686 JvmtiEnv::GetExtensionFunctions(jint* extension_count_ptr, jvmtiExtensionFunctionInfo** extensions) {
3687   return JvmtiExtensions::get_functions(this, extension_count_ptr, extensions);
3688 } /* end GetExtensionFunctions */
3689 
3690 
3691 // extension_count_ptr - pre-checked for null
3692 // extensions - pre-checked for null
3693 jvmtiError
3694 JvmtiEnv::GetExtensionEvents(jint* extension_count_ptr, jvmtiExtensionEventInfo** extensions) {
3695   return JvmtiExtensions::get_events(this, extension_count_ptr, extensions);
3696 } /* end GetExtensionEvents */
3697 
3698 
3699 // callback - null is a valid value, must be checked
3700 jvmtiError
3701 JvmtiEnv::SetExtensionEventCallback(jint extension_event_index, jvmtiExtensionEvent callback) {
3702   return JvmtiExtensions::set_event_callback(this, extension_event_index, callback);
3703 } /* end SetExtensionEventCallback */
3704 
3705   //
3706   // Timers functions
3707   //
3708 
3709 // info_ptr - pre-checked for null
3710 jvmtiError
3711 JvmtiEnv::GetCurrentThreadCpuTimerInfo(jvmtiTimerInfo* info_ptr) {
3712   os::current_thread_cpu_time_info(info_ptr);
3713   return JVMTI_ERROR_NONE;
3714 } /* end GetCurrentThreadCpuTimerInfo */
3715 
3716 
3717 // nanos_ptr - pre-checked for null
3718 jvmtiError
3719 JvmtiEnv::GetCurrentThreadCpuTime(jlong* nanos_ptr) {
3720   Thread* thread = Thread::current();
3721 
3722   // Surprisingly the GetCurrentThreadCpuTime is used by non-JavaThread's.
3723   if (thread->is_Java_thread()) {
3724     if (JavaThread::cast(thread)->is_vthread_mounted()) {
3725       // No support for a VirtualThread (yet).
3726       return JVMTI_ERROR_UNSUPPORTED_OPERATION;
3727     }
3728   }
3729   *nanos_ptr = os::current_thread_cpu_time();
3730   return JVMTI_ERROR_NONE;
3731 } /* end GetCurrentThreadCpuTime */
3732 
3733 
3734 // info_ptr - pre-checked for null
3735 jvmtiError
3736 JvmtiEnv::GetThreadCpuTimerInfo(jvmtiTimerInfo* info_ptr) {
3737   os::thread_cpu_time_info(info_ptr);
3738   return JVMTI_ERROR_NONE;
3739 } /* end GetThreadCpuTimerInfo */
3740 
3741 
3742 // nanos_ptr - pre-checked for null
3743 jvmtiError
3744 JvmtiEnv::GetThreadCpuTime(jthread thread, jlong* nanos_ptr) {
3745   JavaThread* current_thread = JavaThread::current();
3746   ThreadsListHandle tlh(current_thread);
3747   JavaThread* java_thread = nullptr;
3748   oop thread_oop = nullptr;
3749 
3750   jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, current_thread, &java_thread, &thread_oop);
3751 
3752   if (thread_oop != nullptr && thread_oop->is_a(vmClasses::BaseVirtualThread_klass())) {
3753     // No support for virtual threads (yet).
3754     return JVMTI_ERROR_UNSUPPORTED_OPERATION;
3755   }
3756   if (err != JVMTI_ERROR_NONE) {
3757     return err;
3758   }
3759   NULL_CHECK(nanos_ptr, JVMTI_ERROR_NULL_POINTER);
3760 
3761   *nanos_ptr = os::thread_cpu_time(java_thread);
3762   return JVMTI_ERROR_NONE;
3763 } /* end GetThreadCpuTime */
3764 
3765 
3766 // info_ptr - pre-checked for null
3767 jvmtiError
3768 JvmtiEnv::GetTimerInfo(jvmtiTimerInfo* info_ptr) {
3769   os::javaTimeNanos_info(info_ptr);
3770   return JVMTI_ERROR_NONE;
3771 } /* end GetTimerInfo */
3772 
3773 
3774 // nanos_ptr - pre-checked for null
3775 jvmtiError
3776 JvmtiEnv::GetTime(jlong* nanos_ptr) {
3777   *nanos_ptr = os::javaTimeNanos();
3778   return JVMTI_ERROR_NONE;
3779 } /* end GetTime */
3780 
3781 
3782 // processor_count_ptr - pre-checked for null
3783 jvmtiError
3784 JvmtiEnv::GetAvailableProcessors(jint* processor_count_ptr) {
3785   *processor_count_ptr = os::active_processor_count();
3786   return JVMTI_ERROR_NONE;
3787 } /* end GetAvailableProcessors */
3788 
3789 jvmtiError
3790 JvmtiEnv::SetHeapSamplingInterval(jint sampling_interval) {
3791   if (sampling_interval < 0) {
3792     return JVMTI_ERROR_ILLEGAL_ARGUMENT;
3793   }
3794   ThreadHeapSampler::set_sampling_interval(sampling_interval);
3795   return JVMTI_ERROR_NONE;
3796 } /* end SetHeapSamplingInterval */
3797 
3798   //
3799   // System Properties functions
3800   //
3801 
3802 // count_ptr - pre-checked for null
3803 // property_ptr - pre-checked for null
3804 jvmtiError
3805 JvmtiEnv::GetSystemProperties(jint* count_ptr, char*** property_ptr) {
3806   jvmtiError err = JVMTI_ERROR_NONE;
3807 
3808   // Get the number of readable properties.
3809   *count_ptr = Arguments::PropertyList_readable_count(Arguments::system_properties());
3810 
3811   // Allocate memory to hold the exact number of readable properties.
3812   err = allocate(*count_ptr * sizeof(char *), (unsigned char **)property_ptr);
3813   if (err != JVMTI_ERROR_NONE) {
3814     return err;
3815   }
3816   int readable_count = 0;
3817   // Loop through the system properties until all the readable properties are found.
3818   for (SystemProperty* p = Arguments::system_properties(); p != nullptr && readable_count < *count_ptr; p = p->next()) {
3819     if (p->readable()) {
3820       const char *key = p->key();
3821       char **tmp_value = *property_ptr+readable_count;
3822       readable_count++;
3823       err = allocate((strlen(key)+1) * sizeof(char), (unsigned char**)tmp_value);
3824       if (err == JVMTI_ERROR_NONE) {
3825         strcpy(*tmp_value, key);
3826       } else {
3827         // clean up previously allocated memory.
3828         for (int j = 0; j < readable_count; j++) {
3829           Deallocate((unsigned char*)*property_ptr+j);
3830         }
3831         Deallocate((unsigned char*)property_ptr);
3832         break;
3833       }
3834     }
3835   }
3836   assert(err != JVMTI_ERROR_NONE || readable_count == *count_ptr, "Bad readable property count");
3837   return err;
3838 } /* end GetSystemProperties */
3839 
3840 
3841 // property - pre-checked for null
3842 // value_ptr - pre-checked for null
3843 jvmtiError
3844 JvmtiEnv::GetSystemProperty(const char* property, char** value_ptr) {
3845   jvmtiError err = JVMTI_ERROR_NONE;
3846   const char *value;
3847 
3848   // Return JVMTI_ERROR_NOT_AVAILABLE if property is not readable or doesn't exist.
3849   value = Arguments::PropertyList_get_readable_value(Arguments::system_properties(), property);
3850   if (value == nullptr) {
3851     err =  JVMTI_ERROR_NOT_AVAILABLE;
3852   } else {
3853     err = allocate((strlen(value)+1) * sizeof(char), (unsigned char **)value_ptr);
3854     if (err == JVMTI_ERROR_NONE) {
3855       strcpy(*value_ptr, value);
3856     }
3857   }
3858   return err;
3859 } /* end GetSystemProperty */
3860 
3861 
3862 // property - pre-checked for null
3863 // value - null is a valid value, must be checked
3864 jvmtiError
3865 JvmtiEnv::SetSystemProperty(const char* property, const char* value_ptr) {
3866   for (SystemProperty* p = Arguments::system_properties(); p != nullptr; p = p->next()) {
3867     if (strcmp(property, p->key()) == 0) {
3868       if (p->writeable()) {
3869         if (p->set_value(value_ptr, AllocFailStrategy::RETURN_NULL)) {
3870           return JVMTI_ERROR_NONE;
3871         } else {
3872           return JVMTI_ERROR_OUT_OF_MEMORY;
3873         }
3874       } else {
3875         // We found a property, but it's not writeable
3876         return JVMTI_ERROR_NOT_AVAILABLE;
3877       }
3878     }
3879   }
3880 
3881   // We cannot find a property of the given name
3882   return JVMTI_ERROR_NOT_AVAILABLE;
3883 } /* end SetSystemProperty */