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/javaClasses.inline.hpp"
  26 #include "classfile/modules.hpp"
  27 #include "classfile/stringTable.hpp"
  28 #include "classfile/systemDictionary.hpp"
  29 #include "classfile/vmClasses.hpp"
  30 #include "classfile/vmSymbols.hpp"
  31 #include "gc/shared/collectedHeap.hpp"
  32 #include "interpreter/bytecodeStream.hpp"
  33 #include "interpreter/interpreter.hpp"
  34 #include "jfr/jfrEvents.hpp"
  35 #include "jvmtifiles/jvmtiEnv.hpp"
  36 #include "logging/log.hpp"
  37 #include "logging/logConfiguration.hpp"
  38 #include "memory/allocation.hpp"
  39 #include "memory/resourceArea.hpp"
  40 #include "memory/universe.hpp"
  41 #include "oops/fieldStreams.inline.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/signature.hpp"
  73 #include "runtime/threadHeapSampler.hpp"
  74 #include "runtime/threads.hpp"
  75 #include "runtime/threadSMR.hpp"
  76 #include "runtime/timerTrace.hpp"
  77 #include "runtime/vframe.inline.hpp"
  78 #include "runtime/vmThread.hpp"
  79 #include "services/threadService.hpp"
  80 #include "utilities/exceptions.hpp"
  81 #include "utilities/preserveException.hpp"
  82 #include "utilities/utf8.hpp"
  83 
  84 
  85 #define FIXLATER 0 // REMOVE this when completed.
  86 
  87  // FIXLATER: hook into JvmtiTrace
  88 #define TraceJVMTICalls false
  89 
  90 JvmtiEnv::JvmtiEnv(jint version) : JvmtiEnvBase(version) {
  91 }
  92 
  93 JvmtiEnv::~JvmtiEnv() {
  94 }
  95 
  96 JvmtiEnv*
  97 JvmtiEnv::create_a_jvmti(jint version) {
  98   return new JvmtiEnv(version);
  99 }
 100 
 101 // VM operation class to copy jni function table at safepoint.
 102 // More than one java threads or jvmti agents may be reading/
 103 // modifying jni function tables. To reduce the risk of bad
 104 // interaction b/w these threads it is copied at safepoint.
 105 class VM_JNIFunctionTableCopier : public VM_Operation {
 106  private:
 107   const struct JNINativeInterface_ *_function_table;
 108  public:
 109   VM_JNIFunctionTableCopier(const struct JNINativeInterface_ *func_tbl) {
 110     _function_table = func_tbl;
 111   };
 112 
 113   VMOp_Type type() const { return VMOp_JNIFunctionTableCopier; }
 114   void doit() {
 115     copy_jni_function_table(_function_table);
 116   };
 117 };
 118 
 119 //
 120 // Do not change the "prefix" marker below, everything above it is copied
 121 // unchanged into the filled stub, everything below is controlled by the
 122 // stub filler (only method bodies are carried forward, and then only for
 123 // functionality still in the spec).
 124 //
 125 // end file prefix
 126 
 127   //
 128   // Memory Management functions
 129   //
 130 
 131 // mem_ptr - pre-checked for null
 132 jvmtiError
 133 JvmtiEnv::Allocate(jlong size, unsigned char** mem_ptr) {
 134   return allocate(size, mem_ptr);
 135 } /* end Allocate */
 136 
 137 
 138 // mem - null is a valid value, must be checked
 139 jvmtiError
 140 JvmtiEnv::Deallocate(unsigned char* mem) {
 141   return deallocate(mem);
 142 } /* end Deallocate */
 143 
 144 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
 145 // data - null is a valid value, must be checked
 146 jvmtiError
 147 JvmtiEnv::SetThreadLocalStorage(jthread thread, const void* data) {
 148   JavaThread* current = JavaThread::current();
 149   JvmtiThreadState* state = nullptr;
 150   JvmtiVTMSTransitionDisabler disabler(thread);
 151   ThreadsListHandle tlh(current);
 152 
 153   JavaThread* java_thread = nullptr;
 154   oop thread_obj = nullptr;
 155   if (thread == nullptr) {
 156     java_thread = current;
 157     state = java_thread->jvmti_thread_state();
 158   } else {
 159     jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, current, &java_thread, &thread_obj);
 160     if (err != JVMTI_ERROR_NONE) {
 161       return err;
 162     }
 163     state = java_lang_Thread::jvmti_thread_state(thread_obj);
 164   }
 165   if (state == nullptr) {
 166     if (data == nullptr) {
 167       // leaving state unset same as data set to null
 168       return JVMTI_ERROR_NONE;
 169     }
 170     // otherwise, create the state
 171     HandleMark hm(current);
 172     Handle thread_handle(current, thread_obj);
 173     state = JvmtiThreadState::state_for(java_thread, thread_handle);
 174     if (state == nullptr) {
 175       return JVMTI_ERROR_THREAD_NOT_ALIVE;
 176     }
 177   }
 178   state->env_thread_state(this)->set_agent_thread_local_storage_data((void*)data);
 179   return JVMTI_ERROR_NONE;
 180 } /* end SetThreadLocalStorage */
 181 
 182 
 183 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
 184 // data_ptr - pre-checked for null
 185 jvmtiError
 186 JvmtiEnv::GetThreadLocalStorage(jthread thread, void** data_ptr) {
 187   JavaThread* current_thread = JavaThread::current();
 188   if (thread == nullptr) {
 189     JvmtiThreadState* state = current_thread->jvmti_thread_state();
 190     *data_ptr = (state == nullptr) ? nullptr :
 191       state->env_thread_state(this)->get_agent_thread_local_storage_data();
 192   } else {
 193     // jvmti_GetThreadLocalStorage is "in native" and doesn't transition
 194     // the thread to _thread_in_vm. However, when the TLS for a thread
 195     // other than the current thread is required we need to transition
 196     // from native so as to resolve the jthread.
 197 
 198     MACOS_AARCH64_ONLY(ThreadWXEnable __wx(WXWrite, current_thread));
 199     ThreadInVMfromNative __tiv(current_thread);
 200     VM_ENTRY_BASE(jvmtiError, JvmtiEnv::GetThreadLocalStorage , current_thread)
 201     DEBUG_ONLY(VMNativeEntryWrapper __vew;)
 202 
 203     JvmtiVTMSTransitionDisabler disabler(thread);
 204     ThreadsListHandle tlh(current_thread);
 205 
 206     JavaThread* java_thread = nullptr;
 207     oop thread_obj = nullptr;
 208     jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, current_thread, &java_thread, &thread_obj);
 209     if (err != JVMTI_ERROR_NONE) {
 210       return err;
 211     }
 212 
 213     HandleMark hm(current_thread);
 214     Handle thread_handle(current_thread, thread_obj);
 215     JvmtiThreadState* state = JvmtiThreadState::state_for(java_thread, thread_handle);
 216     *data_ptr = (state == nullptr) ? nullptr :
 217       state->env_thread_state(this)->get_agent_thread_local_storage_data();
 218   }
 219   return JVMTI_ERROR_NONE;
 220 } /* end GetThreadLocalStorage */
 221 
 222   //
 223   // Module functions
 224   //
 225 
 226 // module_count_ptr - pre-checked for null
 227 // modules_ptr - pre-checked for null
 228 jvmtiError
 229 JvmtiEnv::GetAllModules(jint* module_count_ptr, jobject** modules_ptr) {
 230     JvmtiModuleClosure jmc;
 231 
 232     return jmc.get_all_modules(this, module_count_ptr, modules_ptr);
 233 } /* end GetAllModules */
 234 
 235 
 236 // class_loader - null is a valid value, must be pre-checked
 237 // package_name - pre-checked for null
 238 // module_ptr - pre-checked for null
 239 jvmtiError
 240 JvmtiEnv::GetNamedModule(jobject class_loader, const char* package_name, jobject* module_ptr) {
 241   JavaThread* THREAD = JavaThread::current(); // For exception macros.
 242   ResourceMark rm(THREAD);
 243 
 244   Handle h_loader (THREAD, JNIHandles::resolve(class_loader));
 245   // Check that loader is a subclass of java.lang.ClassLoader.
 246   if (h_loader.not_null() && !java_lang_ClassLoader::is_subclass(h_loader->klass())) {
 247     return JVMTI_ERROR_ILLEGAL_ARGUMENT;
 248   }
 249   oop module = Modules::get_named_module(h_loader, package_name);
 250   *module_ptr = module != nullptr ? JNIHandles::make_local(THREAD, module) : nullptr;
 251   return JVMTI_ERROR_NONE;
 252 } /* end GetNamedModule */
 253 
 254 
 255 // module - pre-checked for null
 256 // to_module - pre-checked for null
 257 jvmtiError
 258 JvmtiEnv::AddModuleReads(jobject module, jobject to_module) {
 259   JavaThread* THREAD = JavaThread::current(); // For exception macros.
 260 
 261   // check module
 262   Handle h_module(THREAD, JNIHandles::resolve(module));
 263   if (!java_lang_Module::is_instance(h_module())) {
 264     return JVMTI_ERROR_INVALID_MODULE;
 265   }
 266   // check to_module
 267   Handle h_to_module(THREAD, JNIHandles::resolve(to_module));
 268   if (!java_lang_Module::is_instance(h_to_module())) {
 269     return JVMTI_ERROR_INVALID_MODULE;
 270   }
 271   return JvmtiExport::add_module_reads(h_module, h_to_module, THREAD);
 272 } /* end AddModuleReads */
 273 
 274 
 275 // module - pre-checked for null
 276 // pkg_name - pre-checked for null
 277 // to_module - pre-checked for null
 278 jvmtiError
 279 JvmtiEnv::AddModuleExports(jobject module, const char* pkg_name, jobject to_module) {
 280   JavaThread* THREAD = JavaThread::current(); // For exception macros.
 281   Handle h_pkg = java_lang_String::create_from_str(pkg_name, THREAD);
 282 
 283   // check module
 284   Handle h_module(THREAD, JNIHandles::resolve(module));
 285   if (!java_lang_Module::is_instance(h_module())) {
 286     return JVMTI_ERROR_INVALID_MODULE;
 287   }
 288   // check to_module
 289   Handle h_to_module(THREAD, JNIHandles::resolve(to_module));
 290   if (!java_lang_Module::is_instance(h_to_module())) {
 291     return JVMTI_ERROR_INVALID_MODULE;
 292   }
 293   return JvmtiExport::add_module_exports(h_module, h_pkg, h_to_module, THREAD);
 294 } /* end AddModuleExports */
 295 
 296 
 297 // module - pre-checked for null
 298 // pkg_name - pre-checked for null
 299 // to_module - pre-checked for null
 300 jvmtiError
 301 JvmtiEnv::AddModuleOpens(jobject module, const char* pkg_name, jobject to_module) {
 302   JavaThread* THREAD = JavaThread::current(); // For exception macros.
 303   Handle h_pkg = java_lang_String::create_from_str(pkg_name, THREAD);
 304 
 305   // check module
 306   Handle h_module(THREAD, JNIHandles::resolve(module));
 307   if (!java_lang_Module::is_instance(h_module())) {
 308     return JVMTI_ERROR_INVALID_MODULE;
 309   }
 310   // check to_module
 311   Handle h_to_module(THREAD, JNIHandles::resolve(to_module));
 312   if (!java_lang_Module::is_instance(h_to_module())) {
 313     return JVMTI_ERROR_INVALID_MODULE;
 314   }
 315   return JvmtiExport::add_module_opens(h_module, h_pkg, h_to_module, THREAD);
 316 } /* end AddModuleOpens */
 317 
 318 
 319 // module - pre-checked for null
 320 // service - pre-checked for null
 321 jvmtiError
 322 JvmtiEnv::AddModuleUses(jobject module, jclass service) {
 323   JavaThread* THREAD = JavaThread::current(); // For exception macros.
 324 
 325   // check module
 326   Handle h_module(THREAD, JNIHandles::resolve(module));
 327   if (!java_lang_Module::is_instance(h_module())) {
 328     return JVMTI_ERROR_INVALID_MODULE;
 329   }
 330   // check service
 331   Handle h_service(THREAD, JNIHandles::resolve_external_guard(service));
 332   if (!java_lang_Class::is_instance(h_service()) ||
 333       java_lang_Class::is_primitive(h_service())) {
 334     return JVMTI_ERROR_INVALID_CLASS;
 335   }
 336   return JvmtiExport::add_module_uses(h_module, h_service, THREAD);
 337 } /* end AddModuleUses */
 338 
 339 
 340 // module - pre-checked for null
 341 // service - pre-checked for null
 342 // impl_class - pre-checked for null
 343 jvmtiError
 344 JvmtiEnv::AddModuleProvides(jobject module, jclass service, jclass impl_class) {
 345   JavaThread* THREAD = JavaThread::current(); // For exception macros.
 346 
 347   // check module
 348   Handle h_module(THREAD, JNIHandles::resolve(module));
 349   if (!java_lang_Module::is_instance(h_module())) {
 350     return JVMTI_ERROR_INVALID_MODULE;
 351   }
 352   // check service
 353   Handle h_service(THREAD, JNIHandles::resolve_external_guard(service));
 354   if (!java_lang_Class::is_instance(h_service()) ||
 355       java_lang_Class::is_primitive(h_service())) {
 356     return JVMTI_ERROR_INVALID_CLASS;
 357   }
 358   // check impl_class
 359   Handle h_impl_class(THREAD, JNIHandles::resolve_external_guard(impl_class));
 360   if (!java_lang_Class::is_instance(h_impl_class()) ||
 361       java_lang_Class::is_primitive(h_impl_class())) {
 362     return JVMTI_ERROR_INVALID_CLASS;
 363   }
 364   return JvmtiExport::add_module_provides(h_module, h_service, h_impl_class, THREAD);
 365 } /* end AddModuleProvides */
 366 
 367 // module - pre-checked for null
 368 // is_modifiable_class_ptr - pre-checked for null
 369 jvmtiError
 370 JvmtiEnv::IsModifiableModule(jobject module, jboolean* is_modifiable_module_ptr) {
 371   JavaThread* current = JavaThread::current();
 372 
 373   // check module
 374   Handle h_module(current, JNIHandles::resolve(module));
 375   if (!java_lang_Module::is_instance(h_module())) {
 376     return JVMTI_ERROR_INVALID_MODULE;
 377   }
 378 
 379   *is_modifiable_module_ptr = JNI_TRUE;
 380   return JVMTI_ERROR_NONE;
 381 } /* end IsModifiableModule */
 382 
 383 
 384   //
 385   // Class functions
 386   //
 387 
 388 // class_count_ptr - pre-checked for null
 389 // classes_ptr - pre-checked for null
 390 jvmtiError
 391 JvmtiEnv::GetLoadedClasses(jint* class_count_ptr, jclass** classes_ptr) {
 392   return JvmtiGetLoadedClasses::getLoadedClasses(this, class_count_ptr, classes_ptr);
 393 } /* end GetLoadedClasses */
 394 
 395 
 396 // initiating_loader - null is a valid value, must be checked
 397 // class_count_ptr - pre-checked for null
 398 // classes_ptr - pre-checked for null
 399 jvmtiError
 400 JvmtiEnv::GetClassLoaderClasses(jobject initiating_loader, jint* class_count_ptr, jclass** classes_ptr) {
 401   return JvmtiGetLoadedClasses::getClassLoaderClasses(this, initiating_loader,
 402                                                   class_count_ptr, classes_ptr);
 403 } /* end GetClassLoaderClasses */
 404 
 405 // k_mirror - may be primitive, this must be checked
 406 // is_modifiable_class_ptr - pre-checked for null
 407 jvmtiError
 408 JvmtiEnv::IsModifiableClass(oop k_mirror, jboolean* is_modifiable_class_ptr) {
 409   *is_modifiable_class_ptr = VM_RedefineClasses::is_modifiable_class(k_mirror)?
 410                                                        JNI_TRUE : JNI_FALSE;
 411   return JVMTI_ERROR_NONE;
 412 } /* end IsModifiableClass */
 413 
 414 // class_count - pre-checked to be greater than or equal to 0
 415 // classes - pre-checked for null
 416 jvmtiError
 417 JvmtiEnv::RetransformClasses(jint class_count, const jclass* classes) {
 418 //TODO: add locking
 419 
 420   int index;
 421   JavaThread* current_thread = JavaThread::current();
 422   ResourceMark rm(current_thread);
 423 
 424   jvmtiClassDefinition* class_definitions =
 425                             NEW_RESOURCE_ARRAY(jvmtiClassDefinition, class_count);
 426   NULL_CHECK(class_definitions, JVMTI_ERROR_OUT_OF_MEMORY);
 427 
 428   for (index = 0; index < class_count; index++) {
 429     HandleMark hm(current_thread);
 430 
 431     jclass jcls = classes[index];
 432     oop k_mirror = JNIHandles::resolve_external_guard(jcls);
 433     if (k_mirror == nullptr) {
 434       return JVMTI_ERROR_INVALID_CLASS;
 435     }
 436     if (!k_mirror->is_a(vmClasses::Class_klass())) {
 437       return JVMTI_ERROR_INVALID_CLASS;
 438     }
 439 
 440     if (!VM_RedefineClasses::is_modifiable_class(k_mirror)) {
 441       return JVMTI_ERROR_UNMODIFIABLE_CLASS;
 442     }
 443 
 444     Klass* klass = java_lang_Class::as_Klass(k_mirror);
 445 
 446     jint status = klass->jvmti_class_status();
 447     if (status & (JVMTI_CLASS_STATUS_ERROR)) {
 448       return JVMTI_ERROR_INVALID_CLASS;
 449     }
 450 
 451     InstanceKlass* ik = InstanceKlass::cast(klass);
 452     if (ik->get_cached_class_file_bytes() == nullptr) {
 453       // Link the class to avoid races with the rewriter. This will call the verifier also
 454       // on the class. Linking is also done in VM_RedefineClasses below, but we need
 455       // to keep that for other VM_RedefineClasses callers.
 456       JavaThread* THREAD = current_thread;
 457       ik->link_class(THREAD);
 458       if (HAS_PENDING_EXCEPTION) {
 459         // Retransform/JVMTI swallows error messages. Using this class will rerun the verifier in a context
 460         // that propagates the VerifyError, if thrown.
 461         CLEAR_PENDING_EXCEPTION;
 462         return JVMTI_ERROR_INVALID_CLASS;
 463       }
 464 
 465       // Not cached, we need to reconstitute the class file from the
 466       // VM representation. We don't attach the reconstituted class
 467       // bytes to the InstanceKlass here because they have not been
 468       // validated and we're not at a safepoint.
 469       JvmtiClassFileReconstituter reconstituter(ik);
 470       if (reconstituter.get_error() != JVMTI_ERROR_NONE) {
 471         return reconstituter.get_error();
 472       }
 473 
 474       class_definitions[index].class_byte_count = (jint)reconstituter.class_file_size();
 475       class_definitions[index].class_bytes      = (unsigned char*)
 476                                                        reconstituter.class_file_bytes();
 477     } else {
 478       // it is cached, get it from the cache
 479       class_definitions[index].class_byte_count = ik->get_cached_class_file_len();
 480       class_definitions[index].class_bytes      = ik->get_cached_class_file_bytes();
 481     }
 482     class_definitions[index].klass              = jcls;
 483   }
 484   EventRetransformClasses event;
 485   VM_RedefineClasses op(class_count, class_definitions, jvmti_class_load_kind_retransform);
 486   VMThread::execute(&op);
 487   jvmtiError error = op.check_error();
 488   if (error == JVMTI_ERROR_NONE) {
 489     event.set_classCount(class_count);
 490     event.set_redefinitionId(op.id());
 491     event.commit();
 492   }
 493   return error;
 494 } /* end RetransformClasses */
 495 
 496 
 497 // class_count - pre-checked to be greater than or equal to 0
 498 // class_definitions - pre-checked for null
 499 jvmtiError
 500 JvmtiEnv::RedefineClasses(jint class_count, const jvmtiClassDefinition* class_definitions) {
 501 //TODO: add locking
 502   EventRedefineClasses event;
 503   VM_RedefineClasses op(class_count, class_definitions, jvmti_class_load_kind_redefine);
 504   VMThread::execute(&op);
 505   jvmtiError error = op.check_error();
 506   if (error == JVMTI_ERROR_NONE) {
 507     event.set_classCount(class_count);
 508     event.set_redefinitionId(op.id());
 509     event.commit();
 510   }
 511   return error;
 512 } /* end RedefineClasses */
 513 
 514 
 515   //
 516   // Object functions
 517   //
 518 
 519 // size_ptr - pre-checked for null
 520 jvmtiError
 521 JvmtiEnv::GetObjectSize(jobject object, jlong* size_ptr) {
 522   oop mirror = JNIHandles::resolve_external_guard(object);
 523   NULL_CHECK(mirror, JVMTI_ERROR_INVALID_OBJECT);
 524   *size_ptr = (jlong)mirror->size() * wordSize;
 525   return JVMTI_ERROR_NONE;
 526 } /* end GetObjectSize */
 527 
 528   //
 529   // Method functions
 530   //
 531 
 532 // prefix - null is a valid value, must be checked
 533 jvmtiError
 534 JvmtiEnv::SetNativeMethodPrefix(const char* prefix) {
 535   return prefix == nullptr?
 536               SetNativeMethodPrefixes(0, nullptr) :
 537               SetNativeMethodPrefixes(1, (char**)&prefix);
 538 } /* end SetNativeMethodPrefix */
 539 
 540 
 541 // prefix_count - pre-checked to be greater than or equal to 0
 542 // prefixes - pre-checked for null
 543 jvmtiError
 544 JvmtiEnv::SetNativeMethodPrefixes(jint prefix_count, char** prefixes) {
 545   // Have to grab JVMTI thread state lock to be sure that some thread
 546   // isn't accessing the prefixes at the same time we are setting them.
 547   // No locks during VM bring-up.
 548   if (Threads::number_of_threads() == 0) {
 549     return set_native_method_prefixes(prefix_count, prefixes);
 550   } else {
 551     MutexLocker mu(JvmtiThreadState_lock);
 552     return set_native_method_prefixes(prefix_count, prefixes);
 553   }
 554 } /* end SetNativeMethodPrefixes */
 555 
 556   //
 557   // Event Management functions
 558   //
 559 
 560 // callbacks - null is a valid value, must be checked
 561 // size_of_callbacks - pre-checked to be greater than or equal to 0
 562 jvmtiError
 563 JvmtiEnv::SetEventCallbacks(const jvmtiEventCallbacks* callbacks, jint size_of_callbacks) {
 564   JvmtiVTMSTransitionDisabler disabler;
 565   JvmtiEventController::set_event_callbacks(this, callbacks, size_of_callbacks);
 566   return JVMTI_ERROR_NONE;
 567 } /* end SetEventCallbacks */
 568 
 569 
 570 // event_thread - null is a valid value, must be checked
 571 jvmtiError
 572 JvmtiEnv::SetEventNotificationMode(jvmtiEventMode mode, jvmtiEvent event_type, jthread event_thread,   ...) {
 573   bool enabled = (mode == JVMTI_ENABLE);
 574 
 575   // event_type must be valid
 576   if (!JvmtiEventController::is_valid_event_type(event_type)) {
 577     return JVMTI_ERROR_INVALID_EVENT_TYPE;
 578   }
 579 
 580   // assure that needed capabilities are present
 581   if (enabled && !JvmtiUtil::has_event_capability(event_type, get_capabilities())) {
 582     return JVMTI_ERROR_MUST_POSSESS_CAPABILITY;
 583   }
 584 
 585   if (event_type == JVMTI_EVENT_CLASS_FILE_LOAD_HOOK && enabled) {
 586     record_class_file_load_hook_enabled();
 587   }
 588   JvmtiVTMSTransitionDisabler disabler;
 589 
 590   if (event_thread == nullptr) {
 591     // Can be called at Agent_OnLoad() time with event_thread == nullptr
 592     // when Thread::current() does not work yet so we cannot create a
 593     // ThreadsListHandle that is common to both thread-specific and
 594     // global code paths.
 595 
 596     JvmtiEventController::set_user_enabled(this, nullptr, (oop) nullptr, event_type, enabled);
 597   } else {
 598     // We have a specified event_thread.
 599     JavaThread* current = JavaThread::current();
 600     ThreadsListHandle tlh(current);
 601 
 602     JavaThread* java_thread = nullptr;
 603     oop thread_obj = nullptr;
 604     jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), event_thread, current, &java_thread, &thread_obj);
 605     if (err != JVMTI_ERROR_NONE) {
 606       return err;
 607     }
 608 
 609     // global events cannot be controlled at thread level.
 610     if (JvmtiEventController::is_global_event(event_type)) {
 611       return JVMTI_ERROR_ILLEGAL_ARGUMENT;
 612     }
 613 
 614     JvmtiEventController::set_user_enabled(this, java_thread, thread_obj, event_type, enabled);
 615   }
 616 
 617   return JVMTI_ERROR_NONE;
 618 } /* end SetEventNotificationMode */
 619 
 620   //
 621   // Capability functions
 622   //
 623 
 624 // capabilities_ptr - pre-checked for null
 625 jvmtiError
 626 JvmtiEnv::GetPotentialCapabilities(jvmtiCapabilities* capabilities_ptr) {
 627   JvmtiManageCapabilities::get_potential_capabilities(get_capabilities(),
 628                                                       get_prohibited_capabilities(),
 629                                                       capabilities_ptr);
 630   return JVMTI_ERROR_NONE;
 631 } /* end GetPotentialCapabilities */
 632 
 633 
 634 // capabilities_ptr - pre-checked for null
 635 jvmtiError
 636 JvmtiEnv::AddCapabilities(const jvmtiCapabilities* capabilities_ptr) {
 637   return JvmtiManageCapabilities::add_capabilities(get_capabilities(),
 638                                                    get_prohibited_capabilities(),
 639                                                    capabilities_ptr,
 640                                                    get_capabilities());
 641 } /* end AddCapabilities */
 642 
 643 
 644 // capabilities_ptr - pre-checked for null
 645 jvmtiError
 646 JvmtiEnv::RelinquishCapabilities(const jvmtiCapabilities* capabilities_ptr) {
 647   JvmtiManageCapabilities::relinquish_capabilities(get_capabilities(), capabilities_ptr, get_capabilities());
 648   return JVMTI_ERROR_NONE;
 649 } /* end RelinquishCapabilities */
 650 
 651 
 652 // capabilities_ptr - pre-checked for null
 653 jvmtiError
 654 JvmtiEnv::GetCapabilities(jvmtiCapabilities* capabilities_ptr) {
 655   JvmtiManageCapabilities::copy_capabilities(get_capabilities(), capabilities_ptr);
 656   return JVMTI_ERROR_NONE;
 657 } /* end GetCapabilities */
 658 
 659   //
 660   // Class Loader Search functions
 661   //
 662 
 663 // segment - pre-checked for null
 664 jvmtiError
 665 JvmtiEnv::AddToBootstrapClassLoaderSearch(const char* segment) {
 666   jvmtiPhase phase = get_phase();
 667   if (phase == JVMTI_PHASE_ONLOAD) {
 668     Arguments::append_sysclasspath(segment);
 669     return JVMTI_ERROR_NONE;
 670   } else if (use_version_1_0_semantics()) {
 671     // This JvmtiEnv requested version 1.0 semantics and this function
 672     // is only allowed in the ONLOAD phase in version 1.0 so we need to
 673     // return an error here.
 674     return JVMTI_ERROR_WRONG_PHASE;
 675   } else if (phase == JVMTI_PHASE_LIVE) {
 676     // The phase is checked by the wrapper that called this function,
 677     // but this thread could be racing with the thread that is
 678     // terminating the VM so we check one more time.
 679 
 680     // create the zip entry
 681     ClassPathZipEntry* zip_entry = ClassLoader::create_class_path_zip_entry(segment);
 682     if (zip_entry == nullptr) {
 683       return JVMTI_ERROR_ILLEGAL_ARGUMENT;
 684     }
 685 
 686     // add the jar file to the bootclasspath
 687     log_info(class, load)("opened: %s", zip_entry->name());
 688 #if INCLUDE_CDS
 689     ClassLoader::append_boot_classpath(zip_entry);
 690 #else
 691     ClassLoader::add_to_boot_append_entries(zip_entry);
 692 #endif
 693     return JVMTI_ERROR_NONE;
 694   } else {
 695     return JVMTI_ERROR_WRONG_PHASE;
 696   }
 697 
 698 } /* end AddToBootstrapClassLoaderSearch */
 699 
 700 
 701 // segment - pre-checked for null
 702 jvmtiError
 703 JvmtiEnv::AddToSystemClassLoaderSearch(const char* segment) {
 704   jvmtiPhase phase = get_phase();
 705 
 706   if (phase == JVMTI_PHASE_ONLOAD) {
 707     for (SystemProperty* p = Arguments::system_properties(); p != nullptr; p = p->next()) {
 708       if (strcmp("java.class.path", p->key()) == 0) {
 709         p->append_value(segment);
 710         break;
 711       }
 712     }
 713     return JVMTI_ERROR_NONE;
 714   } else if (phase == JVMTI_PHASE_LIVE) {
 715     // The phase is checked by the wrapper that called this function,
 716     // but this thread could be racing with the thread that is
 717     // terminating the VM so we check one more time.
 718     JavaThread* THREAD = JavaThread::current(); // For exception macros.
 719     HandleMark hm(THREAD);
 720 
 721     // create the zip entry (which will open the zip file and hence
 722     // check that the segment is indeed a zip file).
 723     ClassPathZipEntry* zip_entry = ClassLoader::create_class_path_zip_entry(segment);
 724     if (zip_entry == nullptr) {
 725       return JVMTI_ERROR_ILLEGAL_ARGUMENT;
 726     }
 727     delete zip_entry;   // no longer needed
 728 
 729     Handle loader(THREAD, SystemDictionary::java_system_loader());
 730 
 731     // need the path as java.lang.String
 732     Handle path = java_lang_String::create_from_platform_dependent_str(segment, THREAD);
 733     if (HAS_PENDING_EXCEPTION) {
 734       CLEAR_PENDING_EXCEPTION;
 735       return JVMTI_ERROR_INTERNAL;
 736     }
 737 
 738     // Invoke the appendToClassPathForInstrumentation method - if the method
 739     // is not found it means the loader doesn't support adding to the class path
 740     // in the live phase.
 741     {
 742       JavaValue res(T_VOID);
 743       JavaCalls::call_special(&res,
 744                               loader,
 745                               loader->klass(),
 746                               vmSymbols::appendToClassPathForInstrumentation_name(),
 747                               vmSymbols::appendToClassPathForInstrumentation_signature(),
 748                               path,
 749                               THREAD);
 750       if (HAS_PENDING_EXCEPTION) {
 751         Symbol* ex_name = PENDING_EXCEPTION->klass()->name();
 752         CLEAR_PENDING_EXCEPTION;
 753 
 754         if (ex_name == vmSymbols::java_lang_NoSuchMethodError()) {
 755           return JVMTI_ERROR_CLASS_LOADER_UNSUPPORTED;
 756         } else {
 757           return JVMTI_ERROR_INTERNAL;
 758         }
 759       }
 760     }
 761 
 762     return JVMTI_ERROR_NONE;
 763   } else {
 764     return JVMTI_ERROR_WRONG_PHASE;
 765   }
 766 } /* end AddToSystemClassLoaderSearch */
 767 
 768   //
 769   // General functions
 770   //
 771 
 772 // phase_ptr - pre-checked for null
 773 jvmtiError
 774 JvmtiEnv::GetPhase(jvmtiPhase* phase_ptr) {
 775   *phase_ptr = phase();
 776   return JVMTI_ERROR_NONE;
 777 } /* end GetPhase */
 778 
 779 
 780 jvmtiError
 781 JvmtiEnv::DisposeEnvironment() {
 782   dispose();
 783   return JVMTI_ERROR_NONE;
 784 } /* end DisposeEnvironment */
 785 
 786 
 787 // data - null is a valid value, must be checked
 788 jvmtiError
 789 JvmtiEnv::SetEnvironmentLocalStorage(const void* data) {
 790   set_env_local_storage(data);
 791   return JVMTI_ERROR_NONE;
 792 } /* end SetEnvironmentLocalStorage */
 793 
 794 
 795 // data_ptr - pre-checked for null
 796 jvmtiError
 797 JvmtiEnv::GetEnvironmentLocalStorage(void** data_ptr) {
 798   *data_ptr = (void*)get_env_local_storage();
 799   return JVMTI_ERROR_NONE;
 800 } /* end GetEnvironmentLocalStorage */
 801 
 802 // version_ptr - pre-checked for null
 803 jvmtiError
 804 JvmtiEnv::GetVersionNumber(jint* version_ptr) {
 805   *version_ptr = JVMTI_VERSION;
 806   return JVMTI_ERROR_NONE;
 807 } /* end GetVersionNumber */
 808 
 809 
 810 // name_ptr - pre-checked for null
 811 jvmtiError
 812 JvmtiEnv::GetErrorName(jvmtiError error, char** name_ptr) {
 813   if (error < JVMTI_ERROR_NONE || error > JVMTI_ERROR_MAX) {
 814     return JVMTI_ERROR_ILLEGAL_ARGUMENT;
 815   }
 816   const char *name = JvmtiUtil::error_name(error);
 817   if (name == nullptr) {
 818     return JVMTI_ERROR_ILLEGAL_ARGUMENT;
 819   }
 820   size_t len = strlen(name) + 1;
 821   jvmtiError err = allocate(len, (unsigned char**)name_ptr);
 822   if (err == JVMTI_ERROR_NONE) {
 823     memcpy(*name_ptr, name, len);
 824   }
 825   return err;
 826 } /* end GetErrorName */
 827 
 828 
 829 jvmtiError
 830 JvmtiEnv::SetVerboseFlag(jvmtiVerboseFlag flag, jboolean value) {
 831   LogLevelType level = value == 0 ? LogLevel::Off : LogLevel::Info;
 832   switch (flag) {
 833   case JVMTI_VERBOSE_OTHER:
 834     // ignore
 835     break;
 836   case JVMTI_VERBOSE_CLASS:
 837     LogConfiguration::configure_stdout(level, false, LOG_TAGS(class, unload));
 838     LogConfiguration::configure_stdout(level, false, LOG_TAGS(class, load));
 839     break;
 840   case JVMTI_VERBOSE_GC:
 841     LogConfiguration::configure_stdout(level, true, LOG_TAGS(gc));
 842     break;
 843   case JVMTI_VERBOSE_JNI:
 844     level = value == 0 ? LogLevel::Off : LogLevel::Debug;
 845     LogConfiguration::configure_stdout(level, true, LOG_TAGS(jni, resolve));
 846     break;
 847   default:
 848     return JVMTI_ERROR_ILLEGAL_ARGUMENT;
 849   };
 850   return JVMTI_ERROR_NONE;
 851 } /* end SetVerboseFlag */
 852 
 853 
 854 // format_ptr - pre-checked for null
 855 jvmtiError
 856 JvmtiEnv::GetJLocationFormat(jvmtiJlocationFormat* format_ptr) {
 857   *format_ptr = JVMTI_JLOCATION_JVMBCI;
 858   return JVMTI_ERROR_NONE;
 859 } /* end GetJLocationFormat */
 860 
 861   //
 862   // Thread functions
 863   //
 864 
 865 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
 866 // thread_state_ptr - pre-checked for null
 867 jvmtiError
 868 JvmtiEnv::GetThreadState(jthread thread, jint* thread_state_ptr) {
 869   JavaThread* current_thread = JavaThread::current();
 870   JvmtiVTMSTransitionDisabler disabler(thread);
 871   ThreadsListHandle tlh(current_thread);
 872 
 873   JavaThread* java_thread = nullptr;
 874   oop thread_oop = nullptr;
 875   jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, current_thread, &java_thread, &thread_oop);
 876   if (err != JVMTI_ERROR_NONE && err != JVMTI_ERROR_THREAD_NOT_ALIVE) {
 877     // We got an error code so we don't have a JavaThread*, but only
 878     // return an error from here if the error is not because the thread
 879     // is a virtual thread.
 880     return err;
 881   }
 882   *thread_state_ptr = JvmtiEnvBase::get_thread_or_vthread_state(thread_oop, java_thread);
 883   return JVMTI_ERROR_NONE;
 884 } /* end GetThreadState */
 885 
 886 
 887 // thread_ptr - pre-checked for null
 888 jvmtiError
 889 JvmtiEnv::GetCurrentThread(jthread* thread_ptr) {
 890   JavaThread* cur_thread = JavaThread::current();
 891   oop thread_oop = get_vthread_or_thread_oop(cur_thread);
 892 
 893   *thread_ptr = (jthread)JNIHandles::make_local(cur_thread, thread_oop);
 894   return JVMTI_ERROR_NONE;
 895 } /* end GetCurrentThread */
 896 
 897 
 898 // threads_count_ptr - pre-checked for null
 899 // threads_ptr - pre-checked for null
 900 jvmtiError
 901 JvmtiEnv::GetAllThreads(jint* threads_count_ptr, jthread** threads_ptr) {
 902   int nthreads        = 0;
 903   Handle *thread_objs = nullptr;
 904   Thread* current_thread = Thread::current();
 905   ResourceMark rm(current_thread);
 906   HandleMark hm(current_thread);
 907 
 908   // enumerate threads (including agent threads)
 909   ThreadsListEnumerator tle(current_thread, true);
 910   nthreads = tle.num_threads();
 911   *threads_count_ptr = nthreads;
 912 
 913   if (nthreads == 0) {
 914     *threads_ptr = nullptr;
 915     return JVMTI_ERROR_NONE;
 916   }
 917 
 918   thread_objs = NEW_RESOURCE_ARRAY(Handle, nthreads);
 919   NULL_CHECK(thread_objs, JVMTI_ERROR_OUT_OF_MEMORY);
 920 
 921   for (int i = 0; i < nthreads; i++) {
 922     thread_objs[i] = Handle(tle.get_threadObj(i));
 923   }
 924 
 925   jthread *jthreads  = new_jthreadArray(nthreads, thread_objs);
 926   NULL_CHECK(jthreads, JVMTI_ERROR_OUT_OF_MEMORY);
 927 
 928   *threads_ptr = jthreads;
 929   return JVMTI_ERROR_NONE;
 930 } /* end GetAllThreads */
 931 
 932 
 933 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
 934 jvmtiError
 935 JvmtiEnv::SuspendThread(jthread thread) {
 936   JavaThread* current = JavaThread::current();
 937   HandleMark hm(current);
 938   Handle self_tobj;
 939 
 940   jvmtiError err;
 941   {
 942     JvmtiVTMSTransitionDisabler disabler(true);
 943     ThreadsListHandle tlh(current);
 944     JavaThread* java_thread = nullptr;
 945     oop thread_oop = nullptr;
 946 
 947     err = get_threadOop_and_JavaThread(tlh.list(), thread, current, &java_thread, &thread_oop);
 948     if (err != JVMTI_ERROR_NONE) {
 949       return err;
 950     }
 951 
 952     // Do not use JvmtiVTMSTransitionDisabler in context of self suspend to avoid deadlocks.
 953     if (java_thread != current) {
 954       err = suspend_thread(thread_oop, java_thread, /* single_suspend */ true);
 955       return err;
 956     }
 957     // protect thread_oop as a safepoint can be reached in disabler destructor
 958     self_tobj = Handle(current, thread_oop);
 959   }
 960   // Do self suspend for current JavaThread.
 961   err = suspend_thread(self_tobj(), current, /* single_suspend */ true);
 962   return err;
 963 } /* end SuspendThread */
 964 
 965 
 966 // request_count - pre-checked to be greater than or equal to 0
 967 // request_list - pre-checked for null
 968 // results - pre-checked for null
 969 jvmtiError
 970 JvmtiEnv::SuspendThreadList(jint request_count, const jthread* request_list, jvmtiError* results) {
 971   JavaThread* current = JavaThread::current();
 972   HandleMark hm(current);
 973   Handle self_tobj;
 974   int self_idx = -1;
 975 
 976   {
 977     JvmtiVTMSTransitionDisabler disabler(true);
 978     ThreadsListHandle tlh(current);
 979 
 980     for (int i = 0; i < request_count; i++) {
 981       JavaThread *java_thread = nullptr;
 982       oop thread_oop = nullptr;
 983       jthread thread = request_list[i];
 984       jvmtiError err = JvmtiExport::cv_external_thread_to_JavaThread(tlh.list(), thread, &java_thread, &thread_oop);
 985 
 986       if (thread_oop != nullptr &&
 987           java_lang_VirtualThread::is_instance(thread_oop) &&
 988           !JvmtiEnvBase::is_vthread_alive(thread_oop)) {
 989         err = JVMTI_ERROR_THREAD_NOT_ALIVE;
 990       }
 991       if (err != JVMTI_ERROR_NONE) {
 992         if (thread_oop == nullptr || err != JVMTI_ERROR_INVALID_THREAD) {
 993           results[i] = err;
 994           continue;
 995         }
 996       }
 997       if (java_thread == current) {
 998         self_idx = i;
 999         self_tobj = Handle(current, thread_oop);
1000         continue; // self suspend after all other suspends
1001       }
1002       if (java_lang_VirtualThread::is_instance(thread_oop)) {
1003         oop carrier_thread = java_lang_VirtualThread::carrier_thread(thread_oop);
1004         java_thread = carrier_thread == nullptr ? nullptr : java_lang_Thread::thread(carrier_thread);
1005       }
1006       results[i] = suspend_thread(thread_oop, java_thread, /* single_suspend */ true);
1007     }
1008   }
1009   // Self suspend after all other suspends if necessary.
1010   // Do not use JvmtiVTMSTransitionDisabler in context of self suspend to avoid deadlocks.
1011   if (self_tobj() != nullptr) {
1012     // there should not be any error for current java_thread
1013     results[self_idx] = suspend_thread(self_tobj(), current, /* single_suspend */ true);
1014   }
1015   // per-thread suspend results returned via results parameter
1016   return JVMTI_ERROR_NONE;
1017 } /* end SuspendThreadList */
1018 
1019 
1020 jvmtiError
1021 JvmtiEnv::SuspendAllVirtualThreads(jint except_count, const jthread* except_list) {
1022   if (get_capabilities()->can_support_virtual_threads == 0) {
1023     return JVMTI_ERROR_MUST_POSSESS_CAPABILITY;
1024   }
1025   JavaThread* current = JavaThread::current();
1026   HandleMark hm(current);
1027   Handle self_tobj;
1028 
1029   {
1030     ResourceMark rm(current);
1031     JvmtiVTMSTransitionDisabler disabler(true);
1032     ThreadsListHandle tlh(current);
1033     GrowableArray<jthread>* elist = new GrowableArray<jthread>(except_count);
1034 
1035     jvmtiError err = JvmtiEnvBase::check_thread_list(except_count, except_list);
1036     if (err != JVMTI_ERROR_NONE) {
1037       return err;
1038     }
1039 
1040     // Collect threads from except_list for which resumed status must be restored (only for VirtualThread case)
1041     for (int idx = 0; idx < except_count; idx++) {
1042       jthread thread = except_list[idx];
1043       oop thread_oop = JNIHandles::resolve_external_guard(thread);
1044       if (java_lang_VirtualThread::is_instance(thread_oop) && !JvmtiVTSuspender::is_vthread_suspended(thread_oop)) {
1045           // is not suspended, so its resumed status must be restored
1046           elist->append(except_list[idx]);
1047       }
1048     }
1049 
1050     for (JavaThreadIteratorWithHandle jtiwh; JavaThread *java_thread = jtiwh.next(); ) {
1051       oop vt_oop = java_thread->jvmti_vthread();
1052       if (!java_thread->is_exiting() &&
1053           !java_thread->is_jvmti_agent_thread() &&
1054           !java_thread->is_hidden_from_external_view() &&
1055           vt_oop != nullptr &&
1056           ((java_lang_VirtualThread::is_instance(vt_oop) &&
1057             JvmtiEnvBase::is_vthread_alive(vt_oop) &&
1058             !JvmtiVTSuspender::is_vthread_suspended(vt_oop)) ||
1059             (vt_oop->is_a(vmClasses::BoundVirtualThread_klass()) && !java_thread->is_suspended())) &&
1060           !is_in_thread_list(except_count, except_list, vt_oop)
1061          ) {
1062         if (java_thread == current) {
1063           self_tobj = Handle(current, vt_oop);
1064           continue; // self suspend after all other suspends
1065         }
1066         suspend_thread(vt_oop, java_thread, /* single_suspend */ false);
1067       }
1068     }
1069     JvmtiVTSuspender::register_all_vthreads_suspend();
1070 
1071     // Restore resumed state for threads from except list that were not suspended before.
1072     for (int idx = 0; idx < elist->length(); idx++) {
1073       jthread thread = elist->at(idx);
1074       oop thread_oop = JNIHandles::resolve_external_guard(thread);
1075       if (JvmtiVTSuspender::is_vthread_suspended(thread_oop)) {
1076         JvmtiVTSuspender::register_vthread_resume(thread_oop);
1077       }
1078     }
1079   }
1080   // Self suspend after all other suspends if necessary.
1081   // Do not use JvmtiVTMSTransitionDisabler in context of self suspend to avoid deadlocks.
1082   if (self_tobj() != nullptr) {
1083     suspend_thread(self_tobj(), current, /* single_suspend */ false);
1084   }
1085   return JVMTI_ERROR_NONE;
1086 } /* end SuspendAllVirtualThreads */
1087 
1088 
1089 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
1090 jvmtiError
1091 JvmtiEnv::ResumeThread(jthread thread) {
1092   JvmtiVTMSTransitionDisabler disabler(true);
1093   JavaThread* current = JavaThread::current();
1094   ThreadsListHandle tlh(current);
1095 
1096   JavaThread* java_thread = nullptr;
1097   oop thread_oop = nullptr;
1098   jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, current, &java_thread, &thread_oop);
1099   if (err != JVMTI_ERROR_NONE) {
1100     return err;
1101   }
1102   err = resume_thread(thread_oop, java_thread, /* single_resume */ true);
1103   return err;
1104 } /* end ResumeThread */
1105 
1106 
1107 // request_count - pre-checked to be greater than or equal to 0
1108 // request_list - pre-checked for null
1109 // results - pre-checked for null
1110 jvmtiError
1111 JvmtiEnv::ResumeThreadList(jint request_count, const jthread* request_list, jvmtiError* results) {
1112   oop thread_oop = nullptr;
1113   JavaThread* java_thread = nullptr;
1114   JvmtiVTMSTransitionDisabler disabler(true);
1115   ThreadsListHandle tlh;
1116 
1117   for (int i = 0; i < request_count; i++) {
1118     jthread thread = request_list[i];
1119     jvmtiError err = JvmtiExport::cv_external_thread_to_JavaThread(tlh.list(), thread, &java_thread, &thread_oop);
1120 
1121     if (thread_oop != nullptr &&
1122         java_lang_VirtualThread::is_instance(thread_oop) &&
1123         !JvmtiEnvBase::is_vthread_alive(thread_oop)) {
1124       err = JVMTI_ERROR_THREAD_NOT_ALIVE;
1125     }
1126     if (err != JVMTI_ERROR_NONE) {
1127       if (thread_oop == nullptr || err != JVMTI_ERROR_INVALID_THREAD) {
1128         results[i] = err;
1129         continue;
1130       }
1131     }
1132     if (java_lang_VirtualThread::is_instance(thread_oop)) {
1133       oop carrier_thread = java_lang_VirtualThread::carrier_thread(thread_oop);
1134       java_thread = carrier_thread == nullptr ? nullptr : java_lang_Thread::thread(carrier_thread);
1135     }
1136     results[i] = resume_thread(thread_oop, java_thread, /* single_resume */ true);
1137   }
1138   // per-thread resume results returned via results parameter
1139   return JVMTI_ERROR_NONE;
1140 } /* end ResumeThreadList */
1141 
1142 
1143 jvmtiError
1144 JvmtiEnv::ResumeAllVirtualThreads(jint except_count, const jthread* except_list) {
1145   if (get_capabilities()->can_support_virtual_threads == 0) {
1146     return JVMTI_ERROR_MUST_POSSESS_CAPABILITY;
1147   }
1148   jvmtiError err = JvmtiEnvBase::check_thread_list(except_count, except_list);
1149   if (err != JVMTI_ERROR_NONE) {
1150     return err;
1151   }
1152   ResourceMark rm;
1153   JvmtiVTMSTransitionDisabler disabler(true);
1154   GrowableArray<jthread>* elist = new GrowableArray<jthread>(except_count);
1155 
1156   // Collect threads from except_list for which suspended status must be restored (only for VirtualThread case)
1157   for (int idx = 0; idx < except_count; idx++) {
1158     jthread thread = except_list[idx];
1159     oop thread_oop = JNIHandles::resolve_external_guard(thread);
1160     if (java_lang_VirtualThread::is_instance(thread_oop) && JvmtiVTSuspender::is_vthread_suspended(thread_oop)) {
1161       // is suspended, so its suspended status must be restored
1162       elist->append(except_list[idx]);
1163     }
1164   }
1165 
1166   for (JavaThreadIteratorWithHandle jtiwh; JavaThread *java_thread = jtiwh.next(); ) {
1167     oop vt_oop = java_thread->jvmti_vthread();
1168     if (!java_thread->is_exiting() &&
1169         !java_thread->is_jvmti_agent_thread() &&
1170         !java_thread->is_hidden_from_external_view() &&
1171         vt_oop != nullptr &&
1172         ((java_lang_VirtualThread::is_instance(vt_oop) &&
1173           JvmtiEnvBase::is_vthread_alive(vt_oop) &&
1174           JvmtiVTSuspender::is_vthread_suspended(vt_oop)) ||
1175           (vt_oop->is_a(vmClasses::BoundVirtualThread_klass()) && java_thread->is_suspended())) &&
1176         !is_in_thread_list(except_count, except_list, vt_oop)
1177     ) {
1178       resume_thread(vt_oop, java_thread, /* single_resume */ false);
1179     }
1180   }
1181   JvmtiVTSuspender::register_all_vthreads_resume();
1182 
1183   // Restore suspended state for threads from except list that were suspended before.
1184   for (int idx = 0; idx < elist->length(); idx++) {
1185     jthread thread = elist->at(idx);
1186     oop thread_oop = JNIHandles::resolve_external_guard(thread);
1187     if (!JvmtiVTSuspender::is_vthread_suspended(thread_oop)) {
1188       JvmtiVTSuspender::register_vthread_suspend(thread_oop);
1189     }
1190   }
1191   return JVMTI_ERROR_NONE;
1192 } /* end ResumeAllVirtualThreads */
1193 
1194 
1195 jvmtiError
1196 JvmtiEnv::StopThread(jthread thread, jobject exception) {
1197   JavaThread* current_thread = JavaThread::current();
1198 
1199   JvmtiVTMSTransitionDisabler disabler(thread);
1200   ThreadsListHandle tlh(current_thread);
1201   JavaThread* java_thread = nullptr;
1202   oop thread_oop = nullptr;
1203 
1204   NULL_CHECK(thread, JVMTI_ERROR_INVALID_THREAD);
1205 
1206   jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, current_thread, &java_thread, &thread_oop);
1207 
1208   bool is_virtual = thread_oop != nullptr && thread_oop->is_a(vmClasses::BaseVirtualThread_klass());
1209 
1210   if (is_virtual && !is_JavaThread_current(java_thread, thread_oop)) {
1211     if (!is_vthread_suspended(thread_oop, java_thread)) {
1212       return JVMTI_ERROR_THREAD_NOT_SUSPENDED;
1213     }
1214     if (java_thread == nullptr) { // unmounted virtual thread
1215       return JVMTI_ERROR_OPAQUE_FRAME;
1216     }
1217   }
1218   if (err != JVMTI_ERROR_NONE) {
1219     return err;
1220   }
1221   oop e = JNIHandles::resolve_external_guard(exception);
1222   NULL_CHECK(e, JVMTI_ERROR_NULL_POINTER);
1223 
1224   JavaThread::send_async_exception(java_thread, e);
1225 
1226   return JVMTI_ERROR_NONE;
1227 
1228 } /* end StopThread */
1229 
1230 
1231 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
1232 jvmtiError
1233 JvmtiEnv::InterruptThread(jthread thread) {
1234   JavaThread* current_thread = JavaThread::current();
1235   HandleMark hm(current_thread);
1236 
1237   JvmtiVTMSTransitionDisabler disabler(thread);
1238   ThreadsListHandle tlh(current_thread);
1239 
1240   JavaThread* java_thread = nullptr;
1241   oop thread_obj = nullptr;
1242   jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, current_thread, &java_thread, &thread_obj);
1243   if (err != JVMTI_ERROR_NONE) {
1244     return err;
1245   }
1246 
1247   if (java_lang_VirtualThread::is_instance(thread_obj)) {
1248     // For virtual threads we have to call into Java to interrupt:
1249     Handle obj(current_thread, thread_obj);
1250     JvmtiJavaUpcallMark jjum(current_thread); // hide JVMTI events for Java upcall
1251     JavaValue result(T_VOID);
1252     JavaCalls::call_virtual(&result,
1253                             obj,
1254                             vmClasses::Thread_klass(),
1255                             vmSymbols::interrupt_method_name(),
1256                             vmSymbols::void_method_signature(),
1257                             current_thread);
1258 
1259     return JVMTI_ERROR_NONE;
1260   }
1261 
1262   // Really this should be a Java call to Thread.interrupt to ensure the same
1263   // semantics, however historically this has not been done for some reason.
1264   // So we continue with that (which means we don't interact with any Java-level
1265   // Interruptible object) but we must set the Java-level interrupted state.
1266   java_lang_Thread::set_interrupted(thread_obj, true);
1267   java_thread->interrupt();
1268 
1269   return JVMTI_ERROR_NONE;
1270 } /* end InterruptThread */
1271 
1272 
1273 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
1274 // info_ptr - pre-checked for null
1275 jvmtiError
1276 JvmtiEnv::GetThreadInfo(jthread thread, jvmtiThreadInfo* info_ptr) {
1277   JavaThread* current_thread = JavaThread::current();
1278   ResourceMark rm(current_thread);
1279   HandleMark hm(current_thread);
1280   JavaThread* java_thread = nullptr;
1281   oop thread_oop = nullptr;
1282 
1283   JvmtiVTMSTransitionDisabler disabler(thread);
1284   ThreadsListHandle tlh(current_thread);
1285 
1286   // if thread is null the current thread is used
1287   if (thread == nullptr) {
1288     java_thread = JavaThread::current();
1289     thread_oop = get_vthread_or_thread_oop(java_thread);
1290     if (thread_oop == nullptr || !thread_oop->is_a(vmClasses::Thread_klass())) {
1291       return JVMTI_ERROR_INVALID_THREAD;
1292     }
1293   } else {
1294     jvmtiError err = JvmtiExport::cv_external_thread_to_JavaThread(tlh.list(), thread, &java_thread, &thread_oop);
1295     if (err != JVMTI_ERROR_NONE) {
1296       // We got an error code so we don't have a JavaThread *, but
1297       // only return an error from here if we didn't get a valid
1298       // thread_oop.
1299       // In the virtual thread case the cv_external_thread_to_JavaThread is expected to correctly set
1300       // the thread_oop and return JVMTI_ERROR_INVALID_THREAD which we ignore here.
1301       if (thread_oop == nullptr) {
1302         return err;
1303       }
1304     }
1305   }
1306   // We have a valid thread_oop so we can return some thread info.
1307 
1308   Handle thread_obj(current_thread, thread_oop);
1309   Handle name;
1310   ThreadPriority priority;
1311   Handle     thread_group;
1312   Handle context_class_loader;
1313   bool          is_daemon;
1314 
1315   name = Handle(current_thread, java_lang_Thread::name(thread_obj()));
1316 
1317   if (java_lang_VirtualThread::is_instance(thread_obj())) {
1318     priority = (ThreadPriority)JVMTI_THREAD_NORM_PRIORITY;
1319     is_daemon = true;
1320     if (java_lang_VirtualThread::state(thread_obj()) == java_lang_VirtualThread::TERMINATED) {
1321       thread_group = Handle(current_thread, nullptr);
1322     } else {
1323       thread_group = Handle(current_thread, java_lang_Thread_Constants::get_VTHREAD_GROUP());
1324     }
1325   } else {
1326     priority = java_lang_Thread::priority(thread_obj());
1327     is_daemon = java_lang_Thread::is_daemon(thread_obj());
1328     if (java_lang_Thread::get_thread_status(thread_obj()) == JavaThreadStatus::TERMINATED) {
1329       thread_group = Handle(current_thread, nullptr);
1330     } else {
1331       thread_group = Handle(current_thread, java_lang_Thread::threadGroup(thread_obj()));
1332     }
1333   }
1334 
1335   oop loader = java_lang_Thread::context_class_loader(thread_obj());
1336   context_class_loader = Handle(current_thread, loader);
1337 
1338   { const char *n;
1339 
1340     if (name() != nullptr) {
1341       n = java_lang_String::as_utf8_string(name());
1342     } else {
1343       size_t utf8_length = 0;
1344       n = UNICODE::as_utf8((jchar*) nullptr, utf8_length);
1345     }
1346 
1347     info_ptr->name = (char *) jvmtiMalloc(strlen(n)+1);
1348     if (info_ptr->name == nullptr)
1349       return JVMTI_ERROR_OUT_OF_MEMORY;
1350 
1351     strcpy(info_ptr->name, n);
1352   }
1353   info_ptr->is_daemon = is_daemon;
1354   info_ptr->priority  = priority;
1355 
1356   info_ptr->context_class_loader = (context_class_loader.is_null()) ? nullptr :
1357                                     jni_reference(context_class_loader);
1358   info_ptr->thread_group = jni_reference(thread_group);
1359 
1360   return JVMTI_ERROR_NONE;
1361 } /* end GetThreadInfo */
1362 
1363 
1364 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
1365 // owned_monitor_count_ptr - pre-checked for null
1366 // owned_monitors_ptr - pre-checked for null
1367 jvmtiError
1368 JvmtiEnv::GetOwnedMonitorInfo(jthread thread, jint* owned_monitor_count_ptr, jobject** owned_monitors_ptr) {
1369   JavaThread* calling_thread = JavaThread::current();
1370   HandleMark hm(calling_thread);
1371 
1372   JvmtiVTMSTransitionDisabler disabler(thread);
1373   ThreadsListHandle tlh(calling_thread);
1374 
1375   JavaThread* java_thread = nullptr;
1376   oop thread_oop = nullptr;
1377   jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, calling_thread, &java_thread, &thread_oop);
1378   if (err != JVMTI_ERROR_NONE) {
1379     return err;
1380   }
1381 
1382   // growable array of jvmti monitors info on the C-heap
1383   GrowableArray<jvmtiMonitorStackDepthInfo*> *owned_monitors_list =
1384       new (mtServiceability) GrowableArray<jvmtiMonitorStackDepthInfo*>(1, mtServiceability);
1385 
1386   Handle thread_handle(calling_thread, thread_oop);
1387   EscapeBarrier eb(java_thread != nullptr, calling_thread, java_thread);
1388   if (!eb.deoptimize_objects(MaxJavaStackTraceDepth)) {
1389     delete owned_monitors_list;
1390     return JVMTI_ERROR_OUT_OF_MEMORY;
1391   }
1392   // get owned monitors info with handshake
1393   GetOwnedMonitorInfoClosure op(this, calling_thread, owned_monitors_list);
1394   JvmtiHandshake::execute(&op, &tlh, java_thread, thread_handle);
1395   err = op.result();
1396 
1397   jint owned_monitor_count = owned_monitors_list->length();
1398   if (err == JVMTI_ERROR_NONE) {
1399     if ((err = allocate(owned_monitor_count * sizeof(jobject *),
1400                       (unsigned char**)owned_monitors_ptr)) == JVMTI_ERROR_NONE) {
1401       // copy into the returned array
1402       for (int i = 0; i < owned_monitor_count; i++) {
1403         (*owned_monitors_ptr)[i] =
1404           ((jvmtiMonitorStackDepthInfo*)owned_monitors_list->at(i))->monitor;
1405       }
1406       *owned_monitor_count_ptr = owned_monitor_count;
1407     }
1408   }
1409   // clean up.
1410   for (int i = 0; i < owned_monitor_count; i++) {
1411     deallocate((unsigned char*)owned_monitors_list->at(i));
1412   }
1413   delete owned_monitors_list;
1414 
1415   return err;
1416 } /* end GetOwnedMonitorInfo */
1417 
1418 
1419 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
1420 // monitor_info_count_ptr - pre-checked for null
1421 // monitor_info_ptr - pre-checked for null
1422 jvmtiError
1423 JvmtiEnv::GetOwnedMonitorStackDepthInfo(jthread thread, jint* monitor_info_count_ptr, jvmtiMonitorStackDepthInfo** monitor_info_ptr) {
1424   JavaThread* calling_thread = JavaThread::current();
1425   HandleMark hm(calling_thread);
1426 
1427   JvmtiVTMSTransitionDisabler disabler(thread);
1428   ThreadsListHandle tlh(calling_thread);
1429 
1430   JavaThread* java_thread = nullptr;
1431   oop thread_oop = nullptr;
1432   jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, calling_thread, &java_thread, &thread_oop);
1433   if (err != JVMTI_ERROR_NONE) {
1434     return err;
1435   }
1436 
1437   // growable array of jvmti monitors info on the C-heap
1438   GrowableArray<jvmtiMonitorStackDepthInfo*> *owned_monitors_list =
1439       new (mtServiceability) GrowableArray<jvmtiMonitorStackDepthInfo*>(1, mtServiceability);
1440 
1441   Handle thread_handle(calling_thread, thread_oop);
1442   EscapeBarrier eb(java_thread != nullptr, calling_thread, java_thread);
1443   if (!eb.deoptimize_objects(MaxJavaStackTraceDepth)) {
1444     delete owned_monitors_list;
1445     return JVMTI_ERROR_OUT_OF_MEMORY;
1446   }
1447   // get owned monitors info with handshake
1448   GetOwnedMonitorInfoClosure op(this, calling_thread, owned_monitors_list);
1449   JvmtiHandshake::execute(&op, &tlh, java_thread, thread_handle);
1450   err = op.result();
1451 
1452   jint owned_monitor_count = owned_monitors_list->length();
1453   if (err == JVMTI_ERROR_NONE) {
1454     if ((err = allocate(owned_monitor_count * sizeof(jvmtiMonitorStackDepthInfo),
1455                         (unsigned char**)monitor_info_ptr)) == JVMTI_ERROR_NONE) {
1456       // copy to output array.
1457       for (int i = 0; i < owned_monitor_count; i++) {
1458         (*monitor_info_ptr)[i].monitor =
1459           ((jvmtiMonitorStackDepthInfo*)owned_monitors_list->at(i))->monitor;
1460         (*monitor_info_ptr)[i].stack_depth =
1461           ((jvmtiMonitorStackDepthInfo*)owned_monitors_list->at(i))->stack_depth;
1462       }
1463     }
1464     *monitor_info_count_ptr = owned_monitor_count;
1465   }
1466 
1467   // clean up.
1468   for (int i = 0; i < owned_monitor_count; i++) {
1469     deallocate((unsigned char*)owned_monitors_list->at(i));
1470   }
1471   delete owned_monitors_list;
1472 
1473   return err;
1474 } /* end GetOwnedMonitorStackDepthInfo */
1475 
1476 
1477 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
1478 // monitor_ptr - pre-checked for null
1479 jvmtiError
1480 JvmtiEnv::GetCurrentContendedMonitor(jthread thread, jobject* monitor_ptr) {
1481   JavaThread* current = JavaThread::current();
1482 
1483   *monitor_ptr = nullptr;
1484 
1485   // get contended monitor information with handshake
1486   GetCurrentContendedMonitorClosure op(this, current, monitor_ptr);
1487   JvmtiHandshake::execute(&op, thread);
1488   return op.result();
1489 } /* end GetCurrentContendedMonitor */
1490 
1491 
1492 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
1493 // proc - pre-checked for null
1494 // arg - null is a valid value, must be checked
1495 jvmtiError
1496 JvmtiEnv::RunAgentThread(jthread thread, jvmtiStartFunction proc, const void* arg, jint priority) {
1497   JavaThread* current_thread = JavaThread::current();
1498 
1499   JavaThread* java_thread = nullptr;
1500   oop thread_oop = nullptr;
1501   ThreadsListHandle tlh(current_thread);
1502   jvmtiError err = JvmtiExport::cv_external_thread_to_JavaThread(tlh.list(), thread, &java_thread, &thread_oop);
1503   if (err != JVMTI_ERROR_NONE) {
1504     // We got an error code so we don't have a JavaThread *, but
1505     // only return an error from here if we didn't get a valid
1506     // thread_oop.
1507     if (thread_oop == nullptr) {
1508       return err;
1509     }
1510     // We have a valid thread_oop.
1511   }
1512 
1513   if (thread_oop->is_a(vmClasses::BaseVirtualThread_klass())) {
1514     // No support for virtual threads.
1515     return JVMTI_ERROR_UNSUPPORTED_OPERATION;
1516   }
1517   if (java_thread != nullptr) {
1518     // 'thread' refers to an existing JavaThread.
1519     return JVMTI_ERROR_INVALID_THREAD;
1520   }
1521 
1522   if (priority < JVMTI_THREAD_MIN_PRIORITY || priority > JVMTI_THREAD_MAX_PRIORITY) {
1523     return JVMTI_ERROR_INVALID_PRIORITY;
1524   }
1525 
1526   Handle thread_hndl(current_thread, thread_oop);
1527 
1528   JvmtiAgentThread* new_thread = new JvmtiAgentThread(this, proc, arg);
1529 
1530   // At this point it may be possible that no osthread was created for the
1531   // JavaThread due to lack of resources.
1532   if (new_thread->osthread() == nullptr) {
1533     // The new thread is not known to Thread-SMR yet so we can just delete.
1534     delete new_thread;
1535     return JVMTI_ERROR_OUT_OF_MEMORY;
1536   }
1537 
1538   JavaThread::start_internal_daemon(current_thread, new_thread, thread_hndl,
1539                                     (ThreadPriority)priority);
1540 
1541   return JVMTI_ERROR_NONE;
1542 } /* end RunAgentThread */
1543 
1544   //
1545   // Thread Group functions
1546   //
1547 
1548 // group_count_ptr - pre-checked for null
1549 // groups_ptr - pre-checked for null
1550 jvmtiError
1551 JvmtiEnv::GetTopThreadGroups(jint* group_count_ptr, jthreadGroup** groups_ptr) {
1552   JavaThread* current_thread = JavaThread::current();
1553 
1554   // Only one top level thread group now.
1555   *group_count_ptr = 1;
1556 
1557   // Allocate memory to store global-refs to the thread groups.
1558   // Assume this area is freed by caller.
1559   *groups_ptr = (jthreadGroup *) jvmtiMalloc((sizeof(jthreadGroup)) * (*group_count_ptr));
1560 
1561   NULL_CHECK(*groups_ptr, JVMTI_ERROR_OUT_OF_MEMORY);
1562 
1563   // Convert oop to Handle, then convert Handle to global-ref.
1564   {
1565     HandleMark hm(current_thread);
1566     Handle system_thread_group(current_thread, Universe::system_thread_group());
1567     *groups_ptr[0] = jni_reference(system_thread_group);
1568   }
1569 
1570   return JVMTI_ERROR_NONE;
1571 } /* end GetTopThreadGroups */
1572 
1573 
1574 // info_ptr - pre-checked for null
1575 jvmtiError
1576 JvmtiEnv::GetThreadGroupInfo(jthreadGroup group, jvmtiThreadGroupInfo* info_ptr) {
1577   Thread* current_thread = Thread::current();
1578   ResourceMark rm(current_thread);
1579   HandleMark hm(current_thread);
1580 
1581   Handle group_obj (current_thread, JNIHandles::resolve_external_guard(group));
1582   NULL_CHECK(group_obj(), JVMTI_ERROR_INVALID_THREAD_GROUP);
1583 
1584   const char* name;
1585   Handle parent_group;
1586   bool is_daemon;
1587   ThreadPriority max_priority;
1588 
1589   name         = java_lang_ThreadGroup::name(group_obj());
1590   parent_group = Handle(current_thread, java_lang_ThreadGroup::parent(group_obj()));
1591   is_daemon    = java_lang_ThreadGroup::is_daemon(group_obj());
1592   max_priority = java_lang_ThreadGroup::maxPriority(group_obj());
1593 
1594   info_ptr->is_daemon    = is_daemon;
1595   info_ptr->max_priority = max_priority;
1596   info_ptr->parent       = jni_reference(parent_group);
1597 
1598   if (name != nullptr) {
1599     info_ptr->name = (char*)jvmtiMalloc(strlen(name)+1);
1600     NULL_CHECK(info_ptr->name, JVMTI_ERROR_OUT_OF_MEMORY);
1601     strcpy(info_ptr->name, name);
1602   } else {
1603     info_ptr->name = nullptr;
1604   }
1605 
1606   return JVMTI_ERROR_NONE;
1607 } /* end GetThreadGroupInfo */
1608 
1609 // thread_count_ptr - pre-checked for null
1610 // threads_ptr - pre-checked for null
1611 // group_count_ptr - pre-checked for null
1612 // groups_ptr - pre-checked for null
1613 jvmtiError
1614 JvmtiEnv::GetThreadGroupChildren(jthreadGroup group, jint* thread_count_ptr, jthread** threads_ptr, jint* group_count_ptr, jthreadGroup** groups_ptr) {
1615   jvmtiError err;
1616   JavaThread* current_thread = JavaThread::current();
1617   oop group_obj = JNIHandles::resolve_external_guard(group);
1618   NULL_CHECK(group_obj, JVMTI_ERROR_INVALID_THREAD_GROUP);
1619 
1620   Handle *thread_objs = nullptr;
1621   objArrayHandle group_objs;
1622   jint nthreads = 0;
1623   jint ngroups = 0;
1624   int hidden_threads = 0;
1625 
1626   ResourceMark rm(current_thread);
1627   HandleMark hm(current_thread);
1628 
1629   Handle group_hdl(current_thread, group_obj);
1630 
1631   err = get_live_threads(current_thread, group_hdl, &nthreads, &thread_objs);
1632   if (err != JVMTI_ERROR_NONE) {
1633     return err;
1634   }
1635   err = get_subgroups(current_thread, group_hdl, &ngroups, &group_objs);
1636   if (err != JVMTI_ERROR_NONE) {
1637     return err;
1638   }
1639 
1640   *group_count_ptr  = ngroups;
1641   *thread_count_ptr = nthreads;
1642   *threads_ptr     = new_jthreadArray(nthreads, thread_objs);
1643   *groups_ptr      = new_jthreadGroupArray(ngroups, group_objs);
1644   if (nthreads > 0 && *threads_ptr == nullptr) {
1645     return JVMTI_ERROR_OUT_OF_MEMORY;
1646   }
1647   if (ngroups > 0 && *groups_ptr == nullptr) {
1648     return JVMTI_ERROR_OUT_OF_MEMORY;
1649   }
1650 
1651   return JVMTI_ERROR_NONE;
1652 } /* end GetThreadGroupChildren */
1653 
1654 
1655   //
1656   // Stack Frame functions
1657   //
1658 
1659 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
1660 // max_frame_count - pre-checked to be greater than or equal to 0
1661 // frame_buffer - pre-checked for null
1662 // count_ptr - pre-checked for null
1663 jvmtiError
1664 JvmtiEnv::GetStackTrace(jthread thread, jint start_depth, jint max_frame_count, jvmtiFrameInfo* frame_buffer, jint* count_ptr) {
1665   GetStackTraceClosure op(this, start_depth, max_frame_count, frame_buffer, count_ptr);
1666   JvmtiHandshake::execute(&op, thread);
1667   return op.result();
1668 } /* end GetStackTrace */
1669 
1670 
1671 // max_frame_count - pre-checked to be greater than or equal to 0
1672 // stack_info_ptr - pre-checked for null
1673 // thread_count_ptr - pre-checked for null
1674 jvmtiError
1675 JvmtiEnv::GetAllStackTraces(jint max_frame_count, jvmtiStackInfo** stack_info_ptr, jint* thread_count_ptr) {
1676   jvmtiError err = JVMTI_ERROR_NONE;
1677   JavaThread* calling_thread = JavaThread::current();
1678 
1679   // JVMTI get stack traces at safepoint.
1680   VM_GetAllStackTraces op(this, calling_thread, max_frame_count);
1681   VMThread::execute(&op);
1682   *thread_count_ptr = op.final_thread_count();
1683   *stack_info_ptr = op.stack_info();
1684   err = op.result();
1685   return err;
1686 } /* end GetAllStackTraces */
1687 
1688 
1689 // thread_count - pre-checked to be greater than or equal to 0
1690 // thread_list - pre-checked for null
1691 // max_frame_count - pre-checked to be greater than or equal to 0
1692 // stack_info_ptr - pre-checked for null
1693 jvmtiError
1694 JvmtiEnv::GetThreadListStackTraces(jint thread_count, const jthread* thread_list, jint max_frame_count, jvmtiStackInfo** stack_info_ptr) {
1695   jvmtiError err = JVMTI_ERROR_NONE;
1696 
1697   if (thread_count == 1) {
1698     // Use direct handshake if we need to get only one stack trace.
1699     JavaThread *current_thread = JavaThread::current();
1700 
1701     jthread thread = thread_list[0];
1702 
1703     GetSingleStackTraceClosure op(this, current_thread, thread, max_frame_count);
1704     JvmtiHandshake::execute(&op, thread);
1705     err = op.result();
1706     if (err == JVMTI_ERROR_NONE) {
1707       *stack_info_ptr = op.stack_info();
1708     }
1709   } else {
1710     JvmtiVTMSTransitionDisabler disabler;
1711 
1712     // JVMTI get stack traces at safepoint.
1713     VM_GetThreadListStackTraces op(this, thread_count, thread_list, max_frame_count);
1714     VMThread::execute(&op);
1715     err = op.result();
1716     if (err == JVMTI_ERROR_NONE) {
1717       *stack_info_ptr = op.stack_info();
1718     }
1719   }
1720   return err;
1721 } /* end GetThreadListStackTraces */
1722 
1723 
1724 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
1725 // count_ptr - pre-checked for null
1726 jvmtiError
1727 JvmtiEnv::GetFrameCount(jthread thread, jint* count_ptr) {
1728   GetFrameCountClosure op(this, count_ptr);
1729   JvmtiHandshake::execute(&op, thread);
1730   return op.result();
1731 } /* end GetFrameCount */
1732 
1733 
1734 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
1735 jvmtiError
1736 JvmtiEnv::PopFrame(jthread thread) {
1737   JavaThread* current_thread = JavaThread::current();
1738   HandleMark hm(current_thread);
1739 
1740   if (thread == nullptr) {
1741     return JVMTI_ERROR_INVALID_THREAD;
1742   }
1743   JvmtiVTMSTransitionDisabler disabler(thread);
1744   ThreadsListHandle tlh(current_thread);
1745 
1746   JavaThread* java_thread = nullptr;
1747   oop thread_obj = nullptr;
1748   jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, current_thread, &java_thread, &thread_obj);
1749   Handle thread_handle(current_thread, thread_obj);
1750 
1751   if (err != JVMTI_ERROR_NONE) {
1752     return err;
1753   }
1754   bool self = java_thread == current_thread;
1755 
1756   err = check_non_suspended_or_opaque_frame(java_thread, thread_obj, self);
1757   if (err != JVMTI_ERROR_NONE) {
1758     return err;
1759   }
1760 
1761   // retrieve or create the state
1762   JvmtiThreadState* state = JvmtiThreadState::state_for(java_thread);
1763   if (state == nullptr) {
1764     return JVMTI_ERROR_THREAD_NOT_ALIVE;
1765   }
1766 
1767   // Eagerly reallocate scalar replaced objects.
1768   EscapeBarrier eb(true, current_thread, java_thread);
1769   if (!eb.deoptimize_objects(1)) {
1770     // Reallocation of scalar replaced objects failed -> return with error
1771     return JVMTI_ERROR_OUT_OF_MEMORY;
1772   }
1773 
1774   MutexLocker mu(JvmtiThreadState_lock);
1775   UpdateForPopTopFrameClosure op(state);
1776   JvmtiHandshake::execute(&op, &tlh, java_thread, thread_handle);
1777   return op.result();
1778 } /* end PopFrame */
1779 
1780 
1781 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
1782 // depth - pre-checked as non-negative
1783 // method_ptr - pre-checked for null
1784 // location_ptr - pre-checked for null
1785 jvmtiError
1786 JvmtiEnv::GetFrameLocation(jthread thread, jint depth, jmethodID* method_ptr, jlocation* location_ptr) {
1787   GetFrameLocationClosure op(this, depth, method_ptr, location_ptr);
1788   JvmtiHandshake::execute(&op, thread);
1789   return op.result();
1790 } /* end GetFrameLocation */
1791 
1792 
1793 // Threads_lock NOT held, java_thread not protected by lock
1794 // depth - pre-checked as non-negative
1795 jvmtiError
1796 JvmtiEnv::NotifyFramePop(jthread thread, jint depth) {
1797   ResourceMark rm;
1798   JvmtiVTMSTransitionDisabler disabler(thread);
1799   JavaThread* current = JavaThread::current();
1800   ThreadsListHandle tlh(current);
1801 
1802   JavaThread* java_thread = nullptr;
1803   oop thread_obj = nullptr;
1804   jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, current, &java_thread, &thread_obj);
1805   if (err != JVMTI_ERROR_NONE) {
1806     return err;
1807   }
1808 
1809   HandleMark hm(current);
1810   Handle thread_handle(current, thread_obj);
1811   JvmtiThreadState *state = JvmtiThreadState::state_for(java_thread, thread_handle);
1812   if (state == nullptr) {
1813     return JVMTI_ERROR_THREAD_NOT_ALIVE;
1814   }
1815 
1816   SetOrClearFramePopClosure op(this, state, true /* set */, depth);
1817   MutexLocker mu(current, JvmtiThreadState_lock);
1818   JvmtiHandshake::execute(&op, &tlh, java_thread, thread_handle);
1819   return op.result();
1820 } /* end NotifyFramePop */
1821 
1822 // Threads_lock NOT held, java_thread not protected by lock
1823 jvmtiError
1824 JvmtiEnv::ClearAllFramePops(jthread thread) {
1825   ResourceMark rm;
1826   JvmtiVTMSTransitionDisabler disabler(thread);
1827   JavaThread* current = JavaThread::current();
1828   ThreadsListHandle tlh(current);
1829 
1830   JavaThread* java_thread = nullptr;
1831   oop thread_obj = nullptr;
1832   jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, current, &java_thread, &thread_obj);
1833   if (err != JVMTI_ERROR_NONE) {
1834     return err;
1835   }
1836 
1837   HandleMark hm(current);
1838   Handle thread_handle(current, thread_obj);
1839   JvmtiThreadState *state = JvmtiThreadState::state_for(java_thread, thread_handle);
1840   if (state == nullptr) {
1841     return JVMTI_ERROR_THREAD_NOT_ALIVE;
1842   }
1843 
1844   SetOrClearFramePopClosure op(this, state, false /* clear all frame pops*/);
1845   MutexLocker mu(current, JvmtiThreadState_lock);
1846   JvmtiHandshake::execute(&op, &tlh, java_thread, thread_handle);
1847   return op.result();
1848 } /* end ClearAllFramePops */
1849 
1850   //
1851   // Force Early Return functions
1852   //
1853 
1854 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
1855 jvmtiError
1856 JvmtiEnv::ForceEarlyReturnObject(jthread thread, jobject value) {
1857   jvalue val;
1858   val.l = value;
1859   return force_early_return(thread, val, atos);
1860 } /* end ForceEarlyReturnObject */
1861 
1862 
1863 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
1864 jvmtiError
1865 JvmtiEnv::ForceEarlyReturnInt(jthread thread, jint value) {
1866   jvalue val;
1867   val.i = value;
1868   return force_early_return(thread, val, itos);
1869 } /* end ForceEarlyReturnInt */
1870 
1871 
1872 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
1873 jvmtiError
1874 JvmtiEnv::ForceEarlyReturnLong(jthread thread, jlong value) {
1875   jvalue val;
1876   val.j = value;
1877   return force_early_return(thread, val, ltos);
1878 } /* end ForceEarlyReturnLong */
1879 
1880 
1881 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
1882 jvmtiError
1883 JvmtiEnv::ForceEarlyReturnFloat(jthread thread, jfloat value) {
1884   jvalue val;
1885   val.f = value;
1886   return force_early_return(thread, val, ftos);
1887 } /* end ForceEarlyReturnFloat */
1888 
1889 
1890 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
1891 jvmtiError
1892 JvmtiEnv::ForceEarlyReturnDouble(jthread thread, jdouble value) {
1893   jvalue val;
1894   val.d = value;
1895   return force_early_return(thread, val, dtos);
1896 } /* end ForceEarlyReturnDouble */
1897 
1898 
1899 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
1900 jvmtiError
1901 JvmtiEnv::ForceEarlyReturnVoid(jthread thread) {
1902   jvalue val;
1903   val.j = 0L;
1904   return force_early_return(thread, val, vtos);
1905 } /* end ForceEarlyReturnVoid */
1906 
1907 
1908   //
1909   // Heap functions
1910   //
1911 
1912 // klass - null is a valid value, must be checked
1913 // initial_object - null is a valid value, must be checked
1914 // callbacks - pre-checked for null
1915 // user_data - null is a valid value, must be checked
1916 jvmtiError
1917 JvmtiEnv::FollowReferences(jint heap_filter, jclass klass, jobject initial_object, const jvmtiHeapCallbacks* callbacks, const void* user_data) {
1918   // check klass if provided
1919   Klass* k = nullptr;
1920   if (klass != nullptr) {
1921     oop k_mirror = JNIHandles::resolve_external_guard(klass);
1922     if (k_mirror == nullptr) {
1923       return JVMTI_ERROR_INVALID_CLASS;
1924     }
1925     if (java_lang_Class::is_primitive(k_mirror)) {
1926       return JVMTI_ERROR_NONE;
1927     }
1928     k = java_lang_Class::as_Klass(k_mirror);
1929     if (klass == nullptr) {
1930       return JVMTI_ERROR_INVALID_CLASS;
1931     }
1932   }
1933 
1934   if (initial_object != nullptr) {
1935     oop init_obj = JNIHandles::resolve_external_guard(initial_object);
1936     if (init_obj == nullptr) {
1937       return JVMTI_ERROR_INVALID_OBJECT;
1938     }
1939   }
1940 
1941   Thread *thread = Thread::current();
1942   HandleMark hm(thread);
1943 
1944   TraceTime t("FollowReferences", TRACETIME_LOG(Debug, jvmti, objecttagging));
1945   JvmtiTagMap::tag_map_for(this)->follow_references(heap_filter, k, initial_object, callbacks, user_data);
1946   return JVMTI_ERROR_NONE;
1947 } /* end FollowReferences */
1948 
1949 
1950 // klass - null is a valid value, must be checked
1951 // callbacks - pre-checked for null
1952 // user_data - null is a valid value, must be checked
1953 jvmtiError
1954 JvmtiEnv::IterateThroughHeap(jint heap_filter, jclass klass, const jvmtiHeapCallbacks* callbacks, const void* user_data) {
1955   // check klass if provided
1956   Klass* k = nullptr;
1957   if (klass != nullptr) {
1958     oop k_mirror = JNIHandles::resolve_external_guard(klass);
1959     if (k_mirror == nullptr) {
1960       return JVMTI_ERROR_INVALID_CLASS;
1961     }
1962     if (java_lang_Class::is_primitive(k_mirror)) {
1963       return JVMTI_ERROR_NONE;
1964     }
1965     k = java_lang_Class::as_Klass(k_mirror);
1966     if (k == nullptr) {
1967       return JVMTI_ERROR_INVALID_CLASS;
1968     }
1969   }
1970 
1971   TraceTime t("IterateThroughHeap", TRACETIME_LOG(Debug, jvmti, objecttagging));
1972   JvmtiTagMap::tag_map_for(this)->iterate_through_heap(heap_filter, k, callbacks, user_data);
1973   return JVMTI_ERROR_NONE;
1974 } /* end IterateThroughHeap */
1975 
1976 
1977 // tag_ptr - pre-checked for null
1978 jvmtiError
1979 JvmtiEnv::GetTag(jobject object, jlong* tag_ptr) {
1980   oop o = JNIHandles::resolve_external_guard(object);
1981   NULL_CHECK(o, JVMTI_ERROR_INVALID_OBJECT);
1982   *tag_ptr = JvmtiTagMap::tag_map_for(this)->get_tag(object);
1983   return JVMTI_ERROR_NONE;
1984 } /* end GetTag */
1985 
1986 
1987 jvmtiError
1988 JvmtiEnv::SetTag(jobject object, jlong tag) {
1989   oop o = JNIHandles::resolve_external_guard(object);
1990   NULL_CHECK(o, JVMTI_ERROR_INVALID_OBJECT);
1991   JvmtiTagMap::tag_map_for(this)->set_tag(object, tag);
1992   return JVMTI_ERROR_NONE;
1993 } /* end SetTag */
1994 
1995 
1996 // tag_count - pre-checked to be greater than or equal to 0
1997 // tags - pre-checked for null
1998 // count_ptr - pre-checked for null
1999 // object_result_ptr - null is a valid value, must be checked
2000 // tag_result_ptr - null is a valid value, must be checked
2001 jvmtiError
2002 JvmtiEnv::GetObjectsWithTags(jint tag_count, const jlong* tags, jint* count_ptr, jobject** object_result_ptr, jlong** tag_result_ptr) {
2003   TraceTime t("GetObjectsWithTags", TRACETIME_LOG(Debug, jvmti, objecttagging));
2004   return JvmtiTagMap::tag_map_for(this)->get_objects_with_tags((jlong*)tags, tag_count, count_ptr, object_result_ptr, tag_result_ptr);
2005 } /* end GetObjectsWithTags */
2006 
2007 
2008 jvmtiError
2009 JvmtiEnv::ForceGarbageCollection() {
2010   Universe::heap()->collect(GCCause::_jvmti_force_gc);
2011   return JVMTI_ERROR_NONE;
2012 } /* end ForceGarbageCollection */
2013 
2014 
2015   //
2016   // Heap (1.0) functions
2017   //
2018 
2019 // object_reference_callback - pre-checked for null
2020 // user_data - null is a valid value, must be checked
2021 jvmtiError
2022 JvmtiEnv::IterateOverObjectsReachableFromObject(jobject object, jvmtiObjectReferenceCallback object_reference_callback, const void* user_data) {
2023   oop o = JNIHandles::resolve_external_guard(object);
2024   NULL_CHECK(o, JVMTI_ERROR_INVALID_OBJECT);
2025   JvmtiTagMap::tag_map_for(this)->iterate_over_objects_reachable_from_object(object, object_reference_callback, user_data);
2026   return JVMTI_ERROR_NONE;
2027 } /* end IterateOverObjectsReachableFromObject */
2028 
2029 
2030 // heap_root_callback - null is a valid value, must be checked
2031 // stack_ref_callback - null is a valid value, must be checked
2032 // object_ref_callback - null is a valid value, must be checked
2033 // user_data - null is a valid value, must be checked
2034 jvmtiError
2035 JvmtiEnv::IterateOverReachableObjects(jvmtiHeapRootCallback heap_root_callback, jvmtiStackReferenceCallback stack_ref_callback, jvmtiObjectReferenceCallback object_ref_callback, const void* user_data) {
2036   TraceTime t("IterateOverReachableObjects", TRACETIME_LOG(Debug, jvmti, objecttagging));
2037   JvmtiTagMap::tag_map_for(this)->iterate_over_reachable_objects(heap_root_callback, stack_ref_callback, object_ref_callback, user_data);
2038   return JVMTI_ERROR_NONE;
2039 } /* end IterateOverReachableObjects */
2040 
2041 
2042 // heap_object_callback - pre-checked for null
2043 // user_data - null is a valid value, must be checked
2044 jvmtiError
2045 JvmtiEnv::IterateOverHeap(jvmtiHeapObjectFilter object_filter, jvmtiHeapObjectCallback heap_object_callback, const void* user_data) {
2046   TraceTime t("IterateOverHeap", TRACETIME_LOG(Debug, jvmti, objecttagging));
2047   Thread *thread = Thread::current();
2048   HandleMark hm(thread);
2049   JvmtiTagMap::tag_map_for(this)->iterate_over_heap(object_filter, nullptr, heap_object_callback, user_data);
2050   return JVMTI_ERROR_NONE;
2051 } /* end IterateOverHeap */
2052 
2053 
2054 // k_mirror - may be primitive, this must be checked
2055 // heap_object_callback - pre-checked for null
2056 // user_data - null is a valid value, must be checked
2057 jvmtiError
2058 JvmtiEnv::IterateOverInstancesOfClass(oop k_mirror, jvmtiHeapObjectFilter object_filter, jvmtiHeapObjectCallback heap_object_callback, const void* user_data) {
2059   if (java_lang_Class::is_primitive(k_mirror)) {
2060     // DO PRIMITIVE CLASS PROCESSING
2061     return JVMTI_ERROR_NONE;
2062   }
2063   Klass* klass = java_lang_Class::as_Klass(k_mirror);
2064   if (klass == nullptr) {
2065     return JVMTI_ERROR_INVALID_CLASS;
2066   }
2067   TraceTime t("IterateOverInstancesOfClass", TRACETIME_LOG(Debug, jvmti, objecttagging));
2068   JvmtiTagMap::tag_map_for(this)->iterate_over_heap(object_filter, klass, heap_object_callback, user_data);
2069   return JVMTI_ERROR_NONE;
2070 } /* end IterateOverInstancesOfClass */
2071 
2072 
2073   //
2074   // Local Variable functions
2075   //
2076 
2077 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
2078 // depth - pre-checked as non-negative
2079 // value_ptr - pre-checked for null
2080 jvmtiError
2081 JvmtiEnv::GetLocalObject(jthread thread, jint depth, jint slot, jobject* value_ptr) {
2082   JavaThread* current_thread = JavaThread::current();
2083   // rm object is created to clean up the javaVFrame created in
2084   // doit_prologue(), but after doit() is finished with it.
2085   ResourceMark rm(current_thread);
2086   HandleMark hm(current_thread);
2087   JvmtiVTMSTransitionDisabler disabler(thread);
2088   ThreadsListHandle tlh(current_thread);
2089 
2090   JavaThread* java_thread = nullptr;
2091   oop thread_obj = nullptr;
2092   jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, current_thread, &java_thread, &thread_obj);
2093   if (err != JVMTI_ERROR_NONE) {
2094     return err;
2095   }
2096   bool self = is_JavaThread_current(java_thread, thread_obj);
2097 
2098   if (java_lang_VirtualThread::is_instance(thread_obj)) {
2099     VM_VirtualThreadGetOrSetLocal op(this, Handle(current_thread, thread_obj),
2100                                      current_thread, depth, slot, self);
2101     VMThread::execute(&op);
2102     err = op.result();
2103     if (err == JVMTI_ERROR_NONE) {
2104       *value_ptr = op.value().l;
2105     }
2106   } else {
2107     // Support for ordinary threads
2108     VM_GetOrSetLocal op(java_thread, current_thread, depth, slot, self);
2109     VMThread::execute(&op);
2110     err = op.result();
2111     if (err == JVMTI_ERROR_NONE) {
2112       *value_ptr = op.value().l;
2113     }
2114   }
2115   return err;
2116 } /* end GetLocalObject */
2117 
2118 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
2119 // depth - pre-checked as non-negative
2120 // value - pre-checked for null
2121 jvmtiError
2122 JvmtiEnv::GetLocalInstance(jthread thread, jint depth, jobject* value_ptr){
2123   JavaThread* current_thread = JavaThread::current();
2124   // rm object is created to clean up the javaVFrame created in
2125   // doit_prologue(), but after doit() is finished with it.
2126   ResourceMark rm(current_thread);
2127   HandleMark hm(current_thread);
2128   JvmtiVTMSTransitionDisabler disabler(thread);
2129   ThreadsListHandle tlh(current_thread);
2130 
2131   JavaThread* java_thread = nullptr;
2132   oop thread_obj = nullptr;
2133   jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, current_thread, &java_thread, &thread_obj);
2134   if (err != JVMTI_ERROR_NONE) {
2135     return err;
2136   }
2137   bool self = is_JavaThread_current(java_thread, thread_obj);
2138 
2139   if (java_lang_VirtualThread::is_instance(thread_obj)) {
2140     VM_VirtualThreadGetReceiver op(this, Handle(current_thread, thread_obj),
2141                                    current_thread, depth, self);
2142     VMThread::execute(&op);
2143     err = op.result();
2144     if (err == JVMTI_ERROR_NONE) {
2145       *value_ptr = op.value().l;
2146     }
2147   } else {
2148     // Support for ordinary threads
2149     VM_GetReceiver op(java_thread, current_thread, depth, self);
2150     VMThread::execute(&op);
2151     err = op.result();
2152     if (err == JVMTI_ERROR_NONE) {
2153       *value_ptr = op.value().l;
2154     }
2155   }
2156   return err;
2157 } /* end GetLocalInstance */
2158 
2159 
2160 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
2161 // depth - pre-checked as non-negative
2162 // value_ptr - pre-checked for null
2163 jvmtiError
2164 JvmtiEnv::GetLocalInt(jthread thread, jint depth, jint slot, jint* value_ptr) {
2165   JavaThread* current_thread = JavaThread::current();
2166   // rm object is created to clean up the javaVFrame created in
2167   // doit_prologue(), but after doit() is finished with it.
2168   ResourceMark rm(current_thread);
2169   HandleMark hm(current_thread);
2170   JvmtiVTMSTransitionDisabler disabler(thread);
2171   ThreadsListHandle tlh(current_thread);
2172 
2173   JavaThread* java_thread = nullptr;
2174   oop thread_obj = nullptr;
2175   jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, current_thread, &java_thread, &thread_obj);
2176   if (err != JVMTI_ERROR_NONE) {
2177     return err;
2178   }
2179   bool self = is_JavaThread_current(java_thread, thread_obj);
2180 
2181   if (java_lang_VirtualThread::is_instance(thread_obj)) {
2182     VM_VirtualThreadGetOrSetLocal op(this, Handle(current_thread, thread_obj),
2183                                      depth, slot, T_INT, self);
2184     VMThread::execute(&op);
2185     err = op.result();
2186     if (err == JVMTI_ERROR_NONE) {
2187       *value_ptr = op.value().i;
2188     }
2189   } else {
2190     // Support for ordinary threads
2191     VM_GetOrSetLocal op(java_thread, depth, slot, T_INT, self);
2192     VMThread::execute(&op);
2193     err = op.result();
2194     if (err == JVMTI_ERROR_NONE) {
2195       *value_ptr = op.value().i;
2196     }
2197   }
2198   return err;
2199 } /* end GetLocalInt */
2200 
2201 
2202 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
2203 // depth - pre-checked as non-negative
2204 // value_ptr - pre-checked for null
2205 jvmtiError
2206 JvmtiEnv::GetLocalLong(jthread thread, jint depth, jint slot, jlong* value_ptr) {
2207   JavaThread* current_thread = JavaThread::current();
2208   // rm object is created to clean up the javaVFrame created in
2209   // doit_prologue(), but after doit() is finished with it.
2210   ResourceMark rm(current_thread);
2211   HandleMark hm(current_thread);
2212   JvmtiVTMSTransitionDisabler disabler(thread);
2213   ThreadsListHandle tlh(current_thread);
2214 
2215   JavaThread* java_thread = nullptr;
2216   oop thread_obj = nullptr;
2217   jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, current_thread, &java_thread, &thread_obj);
2218   if (err != JVMTI_ERROR_NONE) {
2219     return err;
2220   }
2221   bool self = is_JavaThread_current(java_thread, thread_obj);
2222 
2223   if (java_lang_VirtualThread::is_instance(thread_obj)) {
2224     VM_VirtualThreadGetOrSetLocal op(this, Handle(current_thread, thread_obj),
2225                                      depth, slot, T_LONG, self);
2226     VMThread::execute(&op);
2227     err = op.result();
2228     if (err == JVMTI_ERROR_NONE) {
2229       *value_ptr = op.value().j;
2230     }
2231   } else {
2232     // Support for ordinary threads
2233     VM_GetOrSetLocal op(java_thread, depth, slot, T_LONG, self);
2234     VMThread::execute(&op);
2235     err = op.result();
2236     if (err == JVMTI_ERROR_NONE) {
2237       *value_ptr = op.value().j;
2238     }
2239   }
2240   return err;
2241 } /* end GetLocalLong */
2242 
2243 
2244 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
2245 // depth - pre-checked as non-negative
2246 // value_ptr - pre-checked for null
2247 jvmtiError
2248 JvmtiEnv::GetLocalFloat(jthread thread, jint depth, jint slot, jfloat* value_ptr) {
2249   JavaThread* current_thread = JavaThread::current();
2250   // rm object is created to clean up the javaVFrame created in
2251   // doit_prologue(), but after doit() is finished with it.
2252   ResourceMark rm(current_thread);
2253   HandleMark hm(current_thread);
2254   JvmtiVTMSTransitionDisabler disabler(thread);
2255   ThreadsListHandle tlh(current_thread);
2256 
2257   JavaThread* java_thread = nullptr;
2258   oop thread_obj = nullptr;
2259   jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, current_thread, &java_thread, &thread_obj);
2260   if (err != JVMTI_ERROR_NONE) {
2261     return err;
2262   }
2263   bool self = is_JavaThread_current(java_thread, thread_obj);
2264 
2265   if (java_lang_VirtualThread::is_instance(thread_obj)) {
2266     VM_VirtualThreadGetOrSetLocal op(this, Handle(current_thread, thread_obj),
2267                                      depth, slot, T_FLOAT, self);
2268     VMThread::execute(&op);
2269     err = op.result();
2270     if (err == JVMTI_ERROR_NONE) {
2271       *value_ptr = op.value().f;
2272     }
2273   } else {
2274     // Support for ordinary threads
2275     VM_GetOrSetLocal op(java_thread, depth, slot, T_FLOAT, self);
2276     VMThread::execute(&op);
2277     err = op.result();
2278     if (err == JVMTI_ERROR_NONE) {
2279       *value_ptr = op.value().f;
2280     }
2281   }
2282   return err;
2283 } /* end GetLocalFloat */
2284 
2285 
2286 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
2287 // depth - pre-checked as non-negative
2288 // value_ptr - pre-checked for null
2289 jvmtiError
2290 JvmtiEnv::GetLocalDouble(jthread thread, jint depth, jint slot, jdouble* value_ptr) {
2291   JavaThread* current_thread = JavaThread::current();
2292   // rm object is created to clean up the javaVFrame created in
2293   // doit_prologue(), but after doit() is finished with it.
2294   ResourceMark rm(current_thread);
2295   HandleMark hm(current_thread);
2296   JvmtiVTMSTransitionDisabler disabler(thread);
2297   ThreadsListHandle tlh(current_thread);
2298 
2299   JavaThread* java_thread = nullptr;
2300   oop thread_obj = nullptr;
2301   jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, current_thread, &java_thread, &thread_obj);
2302   if (err != JVMTI_ERROR_NONE) {
2303     return err;
2304   }
2305   bool self = is_JavaThread_current(java_thread, thread_obj);
2306 
2307   if (java_lang_VirtualThread::is_instance(thread_obj)) {
2308     VM_VirtualThreadGetOrSetLocal op(this, Handle(current_thread, thread_obj),
2309                                      depth, slot, T_DOUBLE, self);
2310     VMThread::execute(&op);
2311     err = op.result();
2312     if (err == JVMTI_ERROR_NONE) {
2313       *value_ptr = op.value().d;
2314     }
2315   } else {
2316     // Support for ordinary threads
2317     VM_GetOrSetLocal op(java_thread, depth, slot, T_DOUBLE, self);
2318     VMThread::execute(&op);
2319     err = op.result();
2320     if (err == JVMTI_ERROR_NONE) {
2321       *value_ptr = op.value().d;
2322     }
2323   }
2324   return err;
2325 } /* end GetLocalDouble */
2326 
2327 
2328 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
2329 // depth - pre-checked as non-negative
2330 jvmtiError
2331 JvmtiEnv::SetLocalObject(jthread thread, jint depth, jint slot, jobject value) {
2332   JavaThread* current_thread = JavaThread::current();
2333   // rm object is created to clean up the javaVFrame created in
2334   // doit_prologue(), but after doit() is finished with it.
2335   ResourceMark rm(current_thread);
2336   HandleMark hm(current_thread);
2337   JvmtiVTMSTransitionDisabler disabler(thread);
2338   ThreadsListHandle tlh(current_thread);
2339 
2340   JavaThread* java_thread = nullptr;
2341   oop thread_obj = nullptr;
2342   jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, current_thread, &java_thread, &thread_obj);
2343   if (err != JVMTI_ERROR_NONE) {
2344     return err;
2345   }
2346   bool self = is_JavaThread_current(java_thread, thread_obj);
2347   jvalue val;
2348   val.l = value;
2349 
2350   if (java_lang_VirtualThread::is_instance(thread_obj)) {
2351     VM_VirtualThreadGetOrSetLocal op(this, Handle(current_thread, thread_obj),
2352                                      depth, slot, T_OBJECT, val, self);
2353     VMThread::execute(&op);
2354     err = op.result();
2355   } else {
2356     // Support for ordinary threads
2357     VM_GetOrSetLocal op(java_thread, depth, slot, T_OBJECT, val, self);
2358     VMThread::execute(&op);
2359     err = op.result();
2360   }
2361   return err;
2362 } /* end SetLocalObject */
2363 
2364 
2365 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
2366 // depth - pre-checked as non-negative
2367 jvmtiError
2368 JvmtiEnv::SetLocalInt(jthread thread, jint depth, jint slot, jint value) {
2369   JavaThread* current_thread = JavaThread::current();
2370   // rm object is created to clean up the javaVFrame created in
2371   // doit_prologue(), but after doit() is finished with it.
2372   ResourceMark rm(current_thread);
2373   HandleMark hm(current_thread);
2374   JvmtiVTMSTransitionDisabler disabler(thread);
2375   ThreadsListHandle tlh(current_thread);
2376 
2377   JavaThread* java_thread = nullptr;
2378   oop thread_obj = nullptr;
2379   jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, current_thread, &java_thread, &thread_obj);
2380   if (err != JVMTI_ERROR_NONE) {
2381     return err;
2382   }
2383   bool self = is_JavaThread_current(java_thread, thread_obj);
2384   jvalue val;
2385   val.i = value;
2386 
2387   if (java_lang_VirtualThread::is_instance(thread_obj)) {
2388     VM_VirtualThreadGetOrSetLocal op(this, Handle(current_thread, thread_obj),
2389                                      depth, slot, T_INT, val, self);
2390     VMThread::execute(&op);
2391     err = op.result();
2392   } else {
2393     // Support for ordinary threads
2394     VM_GetOrSetLocal op(java_thread, depth, slot, T_INT, val, self);
2395     VMThread::execute(&op);
2396     err = op.result();
2397   }
2398   return err;
2399 } /* end SetLocalInt */
2400 
2401 
2402 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
2403 // depth - pre-checked as non-negative
2404 jvmtiError
2405 JvmtiEnv::SetLocalLong(jthread thread, jint depth, jint slot, jlong value) {
2406   JavaThread* current_thread = JavaThread::current();
2407   // rm object is created to clean up the javaVFrame created in
2408   // doit_prologue(), but after doit() is finished with it.
2409   ResourceMark rm(current_thread);
2410   HandleMark hm(current_thread);
2411   JvmtiVTMSTransitionDisabler disabler(thread);
2412   ThreadsListHandle tlh(current_thread);
2413 
2414   JavaThread* java_thread = nullptr;
2415   oop thread_obj = nullptr;
2416   jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, current_thread, &java_thread, &thread_obj);
2417   if (err != JVMTI_ERROR_NONE) {
2418     return err;
2419   }
2420   bool self = is_JavaThread_current(java_thread, thread_obj);
2421   jvalue val;
2422   val.j = value;
2423 
2424   if (java_lang_VirtualThread::is_instance(thread_obj)) {
2425     VM_VirtualThreadGetOrSetLocal op(this, Handle(current_thread, thread_obj),
2426                                      depth, slot, T_LONG, val, self);
2427     VMThread::execute(&op);
2428     err = op.result();
2429   } else {
2430     // Support for ordinary threads
2431     VM_GetOrSetLocal op(java_thread, depth, slot, T_LONG, val, self);
2432     VMThread::execute(&op);
2433     err = op.result();
2434   }
2435   return err;
2436 } /* end SetLocalLong */
2437 
2438 
2439 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
2440 // depth - pre-checked as non-negative
2441 jvmtiError
2442 JvmtiEnv::SetLocalFloat(jthread thread, jint depth, jint slot, jfloat value) {
2443   JavaThread* current_thread = JavaThread::current();
2444   // rm object is created to clean up the javaVFrame created in
2445   // doit_prologue(), but after doit() is finished with it.
2446   ResourceMark rm(current_thread);
2447   HandleMark hm(current_thread);
2448   JvmtiVTMSTransitionDisabler disabler(thread);
2449   ThreadsListHandle tlh(current_thread);
2450 
2451   JavaThread* java_thread = nullptr;
2452   oop thread_obj = nullptr;
2453   jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, current_thread, &java_thread, &thread_obj);
2454   if (err != JVMTI_ERROR_NONE) {
2455     return err;
2456   }
2457   bool self = is_JavaThread_current(java_thread, thread_obj);
2458   jvalue val;
2459   val.f = value;
2460 
2461   if (java_lang_VirtualThread::is_instance(thread_obj)) {
2462     VM_VirtualThreadGetOrSetLocal op(this, Handle(current_thread, thread_obj),
2463                                      depth, slot, T_FLOAT, val, self);
2464     VMThread::execute(&op);
2465     err = op.result();
2466   } else {
2467     // Support for ordinary threads
2468     VM_GetOrSetLocal op(java_thread, depth, slot, T_FLOAT, val, self);
2469     VMThread::execute(&op);
2470     err = op.result();
2471   }
2472   return err;
2473 } /* end SetLocalFloat */
2474 
2475 
2476 // thread - NOT protected by ThreadsListHandle and NOT pre-checked
2477 // depth - pre-checked as non-negative
2478 jvmtiError
2479 JvmtiEnv::SetLocalDouble(jthread thread, jint depth, jint slot, jdouble value) {
2480   JavaThread* current_thread = JavaThread::current();
2481   // rm object is created to clean up the javaVFrame created in
2482   // doit_prologue(), but after doit() is finished with it.
2483   ResourceMark rm(current_thread);
2484   HandleMark hm(current_thread);
2485   JvmtiVTMSTransitionDisabler disabler(thread);
2486   ThreadsListHandle tlh(current_thread);
2487 
2488   JavaThread* java_thread = nullptr;
2489   oop thread_obj = nullptr;
2490   jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, current_thread, &java_thread, &thread_obj);
2491   if (err != JVMTI_ERROR_NONE) {
2492     return err;
2493   }
2494   bool self = is_JavaThread_current(java_thread, thread_obj);
2495   jvalue val;
2496   val.d = value;
2497 
2498   if (java_lang_VirtualThread::is_instance(thread_obj)) {
2499     VM_VirtualThreadGetOrSetLocal op(this, Handle(current_thread, thread_obj),
2500                                      depth, slot, T_DOUBLE, val, self);
2501     VMThread::execute(&op);
2502     err = op.result();
2503   } else {
2504     // Support for ordinary threads
2505     VM_GetOrSetLocal op(java_thread, depth, slot, T_DOUBLE, val, self);
2506     VMThread::execute(&op);
2507     err = op.result();
2508   }
2509   return err;
2510 } /* end SetLocalDouble */
2511 
2512 
2513   //
2514   // Breakpoint functions
2515   //
2516 
2517 // method - pre-checked for validity, but may be null meaning obsolete method
2518 jvmtiError
2519 JvmtiEnv::SetBreakpoint(Method* method, jlocation location) {
2520   NULL_CHECK(method, JVMTI_ERROR_INVALID_METHODID);
2521   if (location < 0) {   // simple invalid location check first
2522     return JVMTI_ERROR_INVALID_LOCATION;
2523   }
2524   // verify that the breakpoint is not past the end of the method
2525   if (location >= (jlocation) method->code_size()) {
2526     return JVMTI_ERROR_INVALID_LOCATION;
2527   }
2528 
2529   ResourceMark rm;
2530   JvmtiBreakpoint bp(method, location);
2531   JvmtiBreakpoints& jvmti_breakpoints = JvmtiCurrentBreakpoints::get_jvmti_breakpoints();
2532   if (jvmti_breakpoints.set(bp) == JVMTI_ERROR_DUPLICATE)
2533     return JVMTI_ERROR_DUPLICATE;
2534 
2535   if (TraceJVMTICalls) {
2536     jvmti_breakpoints.print();
2537   }
2538 
2539   return JVMTI_ERROR_NONE;
2540 } /* end SetBreakpoint */
2541 
2542 
2543 // method - pre-checked for validity, but may be null meaning obsolete method
2544 jvmtiError
2545 JvmtiEnv::ClearBreakpoint(Method* method, jlocation location) {
2546   NULL_CHECK(method, JVMTI_ERROR_INVALID_METHODID);
2547 
2548   if (location < 0) {   // simple invalid location check first
2549     return JVMTI_ERROR_INVALID_LOCATION;
2550   }
2551 
2552   // verify that the breakpoint is not past the end of the method
2553   if (location >= (jlocation) method->code_size()) {
2554     return JVMTI_ERROR_INVALID_LOCATION;
2555   }
2556 
2557   JvmtiBreakpoint bp(method, location);
2558 
2559   JvmtiBreakpoints& jvmti_breakpoints = JvmtiCurrentBreakpoints::get_jvmti_breakpoints();
2560   if (jvmti_breakpoints.clear(bp) == JVMTI_ERROR_NOT_FOUND)
2561     return JVMTI_ERROR_NOT_FOUND;
2562 
2563   if (TraceJVMTICalls) {
2564     jvmti_breakpoints.print();
2565   }
2566 
2567   return JVMTI_ERROR_NONE;
2568 } /* end ClearBreakpoint */
2569 
2570 
2571   //
2572   // Watched Field functions
2573   //
2574 
2575 jvmtiError
2576 JvmtiEnv::SetFieldAccessWatch(fieldDescriptor* fdesc_ptr) {
2577   JvmtiVTMSTransitionDisabler disabler;
2578   // make sure we haven't set this watch before
2579   if (fdesc_ptr->is_field_access_watched()) return JVMTI_ERROR_DUPLICATE;
2580   fdesc_ptr->set_is_field_access_watched(true);
2581 
2582   JvmtiEventController::change_field_watch(JVMTI_EVENT_FIELD_ACCESS, true);
2583 
2584   return JVMTI_ERROR_NONE;
2585 } /* end SetFieldAccessWatch */
2586 
2587 
2588 jvmtiError
2589 JvmtiEnv::ClearFieldAccessWatch(fieldDescriptor* fdesc_ptr) {
2590   JvmtiVTMSTransitionDisabler disabler;
2591   // make sure we have a watch to clear
2592   if (!fdesc_ptr->is_field_access_watched()) return JVMTI_ERROR_NOT_FOUND;
2593   fdesc_ptr->set_is_field_access_watched(false);
2594 
2595   JvmtiEventController::change_field_watch(JVMTI_EVENT_FIELD_ACCESS, false);
2596 
2597   return JVMTI_ERROR_NONE;
2598 } /* end ClearFieldAccessWatch */
2599 
2600 
2601 jvmtiError
2602 JvmtiEnv::SetFieldModificationWatch(fieldDescriptor* fdesc_ptr) {
2603   JvmtiVTMSTransitionDisabler disabler;
2604   // make sure we haven't set this watch before
2605   if (fdesc_ptr->is_field_modification_watched()) return JVMTI_ERROR_DUPLICATE;
2606   fdesc_ptr->set_is_field_modification_watched(true);
2607 
2608   JvmtiEventController::change_field_watch(JVMTI_EVENT_FIELD_MODIFICATION, true);
2609 
2610   return JVMTI_ERROR_NONE;
2611 } /* end SetFieldModificationWatch */
2612 
2613 
2614 jvmtiError
2615 JvmtiEnv::ClearFieldModificationWatch(fieldDescriptor* fdesc_ptr) {
2616   JvmtiVTMSTransitionDisabler disabler;
2617    // make sure we have a watch to clear
2618   if (!fdesc_ptr->is_field_modification_watched()) return JVMTI_ERROR_NOT_FOUND;
2619   fdesc_ptr->set_is_field_modification_watched(false);
2620 
2621   JvmtiEventController::change_field_watch(JVMTI_EVENT_FIELD_MODIFICATION, false);
2622 
2623   return JVMTI_ERROR_NONE;
2624 } /* end ClearFieldModificationWatch */
2625 
2626   //
2627   // Class functions
2628   //
2629 
2630 
2631 // k_mirror - may be primitive, this must be checked
2632 // signature_ptr - null is a valid value, must be checked
2633 // generic_ptr - null is a valid value, must be checked
2634 jvmtiError
2635 JvmtiEnv::GetClassSignature(oop k_mirror, char** signature_ptr, char** generic_ptr) {
2636   ResourceMark rm;
2637   bool isPrimitive = java_lang_Class::is_primitive(k_mirror);
2638   Klass* k = nullptr;
2639   if (!isPrimitive) {
2640     k = java_lang_Class::as_Klass(k_mirror);
2641     NULL_CHECK(k, JVMTI_ERROR_INVALID_CLASS);
2642   }
2643   if (signature_ptr != nullptr) {
2644     char* result = nullptr;
2645     if (isPrimitive) {
2646       char tchar = type2char(java_lang_Class::primitive_type(k_mirror));
2647       result = (char*) jvmtiMalloc(2);
2648       result[0] = tchar;
2649       result[1] = '\0';
2650     } else {
2651       const char* class_sig = k->signature_name();
2652       result = (char *) jvmtiMalloc(strlen(class_sig)+1);
2653       strcpy(result, class_sig);
2654     }
2655     *signature_ptr = result;
2656   }
2657   if (generic_ptr != nullptr) {
2658     *generic_ptr = nullptr;
2659     if (!isPrimitive && k->is_instance_klass()) {
2660       Symbol* soo = InstanceKlass::cast(k)->generic_signature();
2661       if (soo != nullptr) {
2662         const char *gen_sig = soo->as_C_string();
2663         if (gen_sig != nullptr) {
2664           char* gen_result;
2665           jvmtiError err = allocate(strlen(gen_sig) + 1,
2666                                     (unsigned char **)&gen_result);
2667           if (err != JVMTI_ERROR_NONE) {
2668             return err;
2669           }
2670           strcpy(gen_result, gen_sig);
2671           *generic_ptr = gen_result;
2672         }
2673       }
2674     }
2675   }
2676   return JVMTI_ERROR_NONE;
2677 } /* end GetClassSignature */
2678 
2679 
2680 // k_mirror - may be primitive, this must be checked
2681 // status_ptr - pre-checked for null
2682 jvmtiError
2683 JvmtiEnv::GetClassStatus(oop k_mirror, jint* status_ptr) {
2684   jint result = 0;
2685   if (java_lang_Class::is_primitive(k_mirror)) {
2686     result |= JVMTI_CLASS_STATUS_PRIMITIVE;
2687   } else {
2688     Klass* k = java_lang_Class::as_Klass(k_mirror);
2689     NULL_CHECK(k, JVMTI_ERROR_INVALID_CLASS);
2690     result = k->jvmti_class_status();
2691   }
2692   *status_ptr = result;
2693 
2694   return JVMTI_ERROR_NONE;
2695 } /* end GetClassStatus */
2696 
2697 
2698 // k_mirror - may be primitive, this must be checked
2699 // source_name_ptr - pre-checked for null
2700 jvmtiError
2701 JvmtiEnv::GetSourceFileName(oop k_mirror, char** source_name_ptr) {
2702   if (java_lang_Class::is_primitive(k_mirror)) {
2703      return JVMTI_ERROR_ABSENT_INFORMATION;
2704   }
2705   Klass* k_klass = java_lang_Class::as_Klass(k_mirror);
2706   NULL_CHECK(k_klass, JVMTI_ERROR_INVALID_CLASS);
2707 
2708   if (!k_klass->is_instance_klass()) {
2709     return JVMTI_ERROR_ABSENT_INFORMATION;
2710   }
2711 
2712   Symbol* sfnOop = InstanceKlass::cast(k_klass)->source_file_name();
2713   NULL_CHECK(sfnOop, JVMTI_ERROR_ABSENT_INFORMATION);
2714   {
2715     JavaThread* current_thread  = JavaThread::current();
2716     ResourceMark rm(current_thread);
2717     const char* sfncp = (const char*) sfnOop->as_C_string();
2718     *source_name_ptr = (char *) jvmtiMalloc(strlen(sfncp)+1);
2719     strcpy(*source_name_ptr, sfncp);
2720   }
2721 
2722   return JVMTI_ERROR_NONE;
2723 } /* end GetSourceFileName */
2724 
2725 
2726 // k_mirror - may be primitive, this must be checked
2727 // modifiers_ptr - pre-checked for null
2728 jvmtiError
2729 JvmtiEnv::GetClassModifiers(oop k_mirror, jint* modifiers_ptr) {
2730   jint result = java_lang_Class::modifiers(k_mirror);
2731   if (!java_lang_Class::is_primitive(k_mirror)) {
2732     // Reset the deleted  ACC_SUPER bit (deleted in compute_modifier_flags()).
2733     result |= JVM_ACC_SUPER;
2734   }
2735   *modifiers_ptr = result;
2736 
2737   return JVMTI_ERROR_NONE;
2738 } /* end GetClassModifiers */
2739 
2740 
2741 // k_mirror - may be primitive, this must be checked
2742 // method_count_ptr - pre-checked for null
2743 // methods_ptr - pre-checked for null
2744 jvmtiError
2745 JvmtiEnv::GetClassMethods(oop k_mirror, jint* method_count_ptr, jmethodID** methods_ptr) {
2746   JavaThread* current_thread  = JavaThread::current();
2747   HandleMark hm(current_thread);
2748 
2749   if (java_lang_Class::is_primitive(k_mirror)) {
2750     *method_count_ptr = 0;
2751     *methods_ptr = (jmethodID*) jvmtiMalloc(0 * sizeof(jmethodID));
2752     return JVMTI_ERROR_NONE;
2753   }
2754   Klass* k = java_lang_Class::as_Klass(k_mirror);
2755   NULL_CHECK(k, JVMTI_ERROR_INVALID_CLASS);
2756 
2757   // Return CLASS_NOT_PREPARED error as per JVMTI spec.
2758   if (!(k->jvmti_class_status() & (JVMTI_CLASS_STATUS_PREPARED|JVMTI_CLASS_STATUS_ARRAY) )) {
2759     return JVMTI_ERROR_CLASS_NOT_PREPARED;
2760   }
2761 
2762   if (!k->is_instance_klass()) {
2763     *method_count_ptr = 0;
2764     *methods_ptr = (jmethodID*) jvmtiMalloc(0 * sizeof(jmethodID));
2765     return JVMTI_ERROR_NONE;
2766   }
2767   InstanceKlass* ik = InstanceKlass::cast(k);
2768   // Allocate the result and fill it in
2769   int result_length = ik->methods()->length();
2770   jmethodID* result_list = (jmethodID*)jvmtiMalloc(result_length * sizeof(jmethodID));
2771   int index;
2772   int skipped = 0;  // skip overpass methods
2773 
2774   // Make jmethodIDs for all non-overpass methods.
2775   ik->make_methods_jmethod_ids();
2776 
2777   for (index = 0; index < result_length; index++) {
2778     Method* m = ik->methods()->at(index);
2779     // Depending on can_maintain_original_method_order capability use the original
2780     // method ordering indices stored in the class, so we can emit jmethodIDs in
2781     // the order they appeared in the class file or just copy in current order.
2782     int result_index = JvmtiExport::can_maintain_original_method_order() ? ik->method_ordering()->at(index) : index;
2783     assert(result_index >= 0 && result_index < result_length, "invalid original method index");
2784     if (m->is_overpass()) {
2785       result_list[result_index] = nullptr;
2786       skipped++;
2787       continue;
2788     }
2789     jmethodID id = m->find_jmethod_id_or_null();
2790     assert(id != nullptr, "should be created above");
2791     result_list[result_index] = id;
2792   }
2793 
2794   // Fill in return value.
2795   if (skipped > 0) {
2796     // copy results skipping null methodIDs
2797     *methods_ptr = (jmethodID*)jvmtiMalloc((result_length - skipped) * sizeof(jmethodID));
2798     *method_count_ptr = result_length - skipped;
2799     for (index = 0, skipped = 0; index < result_length; index++) {
2800       if (result_list[index] == nullptr) {
2801         skipped++;
2802       } else {
2803         (*methods_ptr)[index - skipped] = result_list[index];
2804       }
2805     }
2806     deallocate((unsigned char *)result_list);
2807   } else {
2808     *method_count_ptr = result_length;
2809     *methods_ptr = result_list;
2810   }
2811 
2812   return JVMTI_ERROR_NONE;
2813 } /* end GetClassMethods */
2814 
2815 
2816 // k_mirror - may be primitive, this must be checked
2817 // field_count_ptr - pre-checked for null
2818 // fields_ptr - pre-checked for null
2819 jvmtiError
2820 JvmtiEnv::GetClassFields(oop k_mirror, jint* field_count_ptr, jfieldID** fields_ptr) {
2821   if (java_lang_Class::is_primitive(k_mirror)) {
2822     *field_count_ptr = 0;
2823     *fields_ptr = (jfieldID*) jvmtiMalloc(0 * sizeof(jfieldID));
2824     return JVMTI_ERROR_NONE;
2825   }
2826   JavaThread* current_thread = JavaThread::current();
2827   HandleMark hm(current_thread);
2828   Klass* k = java_lang_Class::as_Klass(k_mirror);
2829   NULL_CHECK(k, JVMTI_ERROR_INVALID_CLASS);
2830 
2831   // Return CLASS_NOT_PREPARED error as per JVMTI spec.
2832   if (!(k->jvmti_class_status() & (JVMTI_CLASS_STATUS_PREPARED|JVMTI_CLASS_STATUS_ARRAY) )) {
2833     return JVMTI_ERROR_CLASS_NOT_PREPARED;
2834   }
2835 
2836   if (!k->is_instance_klass()) {
2837     *field_count_ptr = 0;
2838     *fields_ptr = (jfieldID*) jvmtiMalloc(0 * sizeof(jfieldID));
2839     return JVMTI_ERROR_NONE;
2840   }
2841 
2842   InstanceKlass* ik = InstanceKlass::cast(k);
2843 
2844   JavaFieldStream flds(ik);
2845 
2846   int result_count = ik->java_fields_count();
2847 
2848   // Allocate the result and fill it in.
2849   jfieldID* result_list = (jfieldID*)jvmtiMalloc(result_count * sizeof(jfieldID));
2850   for (int i = 0; i < result_count; i++, flds.next()) {
2851     result_list[i] = jfieldIDWorkaround::to_jfieldID(ik, flds.offset(),
2852                                                      flds.access_flags().is_static());
2853   }
2854   assert(flds.done(), "just checking");
2855 
2856   // Fill in the results
2857   *field_count_ptr = result_count;
2858   *fields_ptr = result_list;
2859 
2860   return JVMTI_ERROR_NONE;
2861 } /* end GetClassFields */
2862 
2863 
2864 // k_mirror - may be primitive, this must be checked
2865 // interface_count_ptr - pre-checked for null
2866 // interfaces_ptr - pre-checked for null
2867 jvmtiError
2868 JvmtiEnv::GetImplementedInterfaces(oop k_mirror, jint* interface_count_ptr, jclass** interfaces_ptr) {
2869   {
2870     if (java_lang_Class::is_primitive(k_mirror)) {
2871       *interface_count_ptr = 0;
2872       *interfaces_ptr = (jclass*) jvmtiMalloc(0 * sizeof(jclass));
2873       return JVMTI_ERROR_NONE;
2874     }
2875     JavaThread* current_thread = JavaThread::current();
2876     HandleMark hm(current_thread);
2877     Klass* k = java_lang_Class::as_Klass(k_mirror);
2878     NULL_CHECK(k, JVMTI_ERROR_INVALID_CLASS);
2879 
2880     // Return CLASS_NOT_PREPARED error as per JVMTI spec.
2881     if (!(k->jvmti_class_status() & (JVMTI_CLASS_STATUS_PREPARED|JVMTI_CLASS_STATUS_ARRAY) ))
2882       return JVMTI_ERROR_CLASS_NOT_PREPARED;
2883 
2884     if (!k->is_instance_klass()) {
2885       *interface_count_ptr = 0;
2886       *interfaces_ptr = (jclass*) jvmtiMalloc(0 * sizeof(jclass));
2887       return JVMTI_ERROR_NONE;
2888     }
2889 
2890     Array<InstanceKlass*>* interface_list = InstanceKlass::cast(k)->local_interfaces();
2891     const int result_length = (interface_list == nullptr ? 0 : interface_list->length());
2892     jclass* result_list = (jclass*) jvmtiMalloc(result_length * sizeof(jclass));
2893     for (int i_index = 0; i_index < result_length; i_index += 1) {
2894       InstanceKlass* klass_at = interface_list->at(i_index);
2895       assert(klass_at->is_klass(), "interfaces must be Klass*s");
2896       assert(klass_at->is_interface(), "interfaces must be interfaces");
2897       oop mirror_at = klass_at->java_mirror();
2898       Handle handle_at = Handle(current_thread, mirror_at);
2899       result_list[i_index] = (jclass) jni_reference(handle_at);
2900     }
2901     *interface_count_ptr = result_length;
2902     *interfaces_ptr = result_list;
2903   }
2904 
2905   return JVMTI_ERROR_NONE;
2906 } /* end GetImplementedInterfaces */
2907 
2908 
2909 // k_mirror - may be primitive, this must be checked
2910 // minor_version_ptr - pre-checked for null
2911 // major_version_ptr - pre-checked for null
2912 jvmtiError
2913 JvmtiEnv::GetClassVersionNumbers(oop k_mirror, jint* minor_version_ptr, jint* major_version_ptr) {
2914   if (java_lang_Class::is_primitive(k_mirror)) {
2915     return JVMTI_ERROR_ABSENT_INFORMATION;
2916   }
2917   Klass* klass = java_lang_Class::as_Klass(k_mirror);
2918 
2919   jint status = klass->jvmti_class_status();
2920   if (status & (JVMTI_CLASS_STATUS_ERROR)) {
2921     return JVMTI_ERROR_INVALID_CLASS;
2922   }
2923   if (status & (JVMTI_CLASS_STATUS_ARRAY)) {
2924     return JVMTI_ERROR_ABSENT_INFORMATION;
2925   }
2926 
2927   InstanceKlass* ik = InstanceKlass::cast(klass);
2928   *minor_version_ptr = ik->minor_version();
2929   *major_version_ptr = ik->major_version();
2930 
2931   return JVMTI_ERROR_NONE;
2932 } /* end GetClassVersionNumbers */
2933 
2934 
2935 // k_mirror - may be primitive, this must be checked
2936 // constant_pool_count_ptr - pre-checked for null
2937 // constant_pool_byte_count_ptr - pre-checked for null
2938 // constant_pool_bytes_ptr - pre-checked for null
2939 jvmtiError
2940 JvmtiEnv::GetConstantPool(oop k_mirror, jint* constant_pool_count_ptr, jint* constant_pool_byte_count_ptr, unsigned char** constant_pool_bytes_ptr) {
2941   if (java_lang_Class::is_primitive(k_mirror)) {
2942     return JVMTI_ERROR_ABSENT_INFORMATION;
2943   }
2944 
2945   Klass* klass = java_lang_Class::as_Klass(k_mirror);
2946   Thread *thread = Thread::current();
2947   ResourceMark rm(thread);
2948 
2949   jint status = klass->jvmti_class_status();
2950   if (status & (JVMTI_CLASS_STATUS_ERROR)) {
2951     return JVMTI_ERROR_INVALID_CLASS;
2952   }
2953   if (status & (JVMTI_CLASS_STATUS_ARRAY)) {
2954     return JVMTI_ERROR_ABSENT_INFORMATION;
2955   }
2956 
2957   InstanceKlass* ik = InstanceKlass::cast(klass);
2958   JvmtiConstantPoolReconstituter reconstituter(ik);
2959   if (reconstituter.get_error() != JVMTI_ERROR_NONE) {
2960     return reconstituter.get_error();
2961   }
2962 
2963   unsigned char *cpool_bytes;
2964   int cpool_size = reconstituter.cpool_size();
2965   if (reconstituter.get_error() != JVMTI_ERROR_NONE) {
2966     return reconstituter.get_error();
2967   }
2968   jvmtiError res = allocate(cpool_size, &cpool_bytes);
2969   if (res != JVMTI_ERROR_NONE) {
2970     return res;
2971   }
2972   reconstituter.copy_cpool_bytes(cpool_bytes);
2973   if (reconstituter.get_error() != JVMTI_ERROR_NONE) {
2974     return reconstituter.get_error();
2975   }
2976 
2977   constantPoolHandle  constants(thread, ik->constants());
2978   *constant_pool_count_ptr      = constants->length();
2979   *constant_pool_byte_count_ptr = cpool_size;
2980   *constant_pool_bytes_ptr      = cpool_bytes;
2981 
2982   return JVMTI_ERROR_NONE;
2983 } /* end GetConstantPool */
2984 
2985 
2986 // k_mirror - may be primitive, this must be checked
2987 // is_interface_ptr - pre-checked for null
2988 jvmtiError
2989 JvmtiEnv::IsInterface(oop k_mirror, jboolean* is_interface_ptr) {
2990   {
2991     bool result = false;
2992     if (!java_lang_Class::is_primitive(k_mirror)) {
2993       Klass* k = java_lang_Class::as_Klass(k_mirror);
2994       if (k != nullptr && k->is_interface()) {
2995         result = true;
2996       }
2997     }
2998     *is_interface_ptr = result;
2999   }
3000 
3001   return JVMTI_ERROR_NONE;
3002 } /* end IsInterface */
3003 
3004 
3005 // k_mirror - may be primitive, this must be checked
3006 // is_array_class_ptr - pre-checked for null
3007 jvmtiError
3008 JvmtiEnv::IsArrayClass(oop k_mirror, jboolean* is_array_class_ptr) {
3009   {
3010     bool result = false;
3011     if (!java_lang_Class::is_primitive(k_mirror)) {
3012       Klass* k = java_lang_Class::as_Klass(k_mirror);
3013       if (k != nullptr && k->is_array_klass()) {
3014         result = true;
3015       }
3016     }
3017     *is_array_class_ptr = result;
3018   }
3019 
3020   return JVMTI_ERROR_NONE;
3021 } /* end IsArrayClass */
3022 
3023 
3024 // k_mirror - may be primitive, this must be checked
3025 // classloader_ptr - pre-checked for null
3026 jvmtiError
3027 JvmtiEnv::GetClassLoader(oop k_mirror, jobject* classloader_ptr) {
3028   {
3029     if (java_lang_Class::is_primitive(k_mirror)) {
3030       *classloader_ptr = (jclass) jni_reference(Handle());
3031       return JVMTI_ERROR_NONE;
3032     }
3033     JavaThread* current_thread = JavaThread::current();
3034     HandleMark hm(current_thread);
3035     Klass* k = java_lang_Class::as_Klass(k_mirror);
3036     NULL_CHECK(k, JVMTI_ERROR_INVALID_CLASS);
3037 
3038     oop result_oop = k->class_loader();
3039     if (result_oop == nullptr) {
3040       *classloader_ptr = (jclass) jni_reference(Handle());
3041       return JVMTI_ERROR_NONE;
3042     }
3043     Handle result_handle = Handle(current_thread, result_oop);
3044     jclass result_jnihandle = (jclass) jni_reference(result_handle);
3045     *classloader_ptr = result_jnihandle;
3046   }
3047   return JVMTI_ERROR_NONE;
3048 } /* end GetClassLoader */
3049 
3050 
3051 // k_mirror - may be primitive, this must be checked
3052 // source_debug_extension_ptr - pre-checked for null
3053 jvmtiError
3054 JvmtiEnv::GetSourceDebugExtension(oop k_mirror, char** source_debug_extension_ptr) {
3055   {
3056     if (java_lang_Class::is_primitive(k_mirror)) {
3057       return JVMTI_ERROR_ABSENT_INFORMATION;
3058     }
3059     Klass* k = java_lang_Class::as_Klass(k_mirror);
3060     NULL_CHECK(k, JVMTI_ERROR_INVALID_CLASS);
3061     if (!k->is_instance_klass()) {
3062       return JVMTI_ERROR_ABSENT_INFORMATION;
3063     }
3064     const char* sde = InstanceKlass::cast(k)->source_debug_extension();
3065     NULL_CHECK(sde, JVMTI_ERROR_ABSENT_INFORMATION);
3066 
3067     {
3068       *source_debug_extension_ptr = (char *) jvmtiMalloc(strlen(sde)+1);
3069       strcpy(*source_debug_extension_ptr, sde);
3070     }
3071   }
3072 
3073   return JVMTI_ERROR_NONE;
3074 } /* end GetSourceDebugExtension */
3075 
3076   //
3077   // Object functions
3078   //
3079 
3080 // hash_code_ptr - pre-checked for null
3081 jvmtiError
3082 JvmtiEnv::GetObjectHashCode(jobject object, jint* hash_code_ptr) {
3083   oop mirror = JNIHandles::resolve_external_guard(object);
3084   NULL_CHECK(mirror, JVMTI_ERROR_INVALID_OBJECT);
3085   NULL_CHECK(hash_code_ptr, JVMTI_ERROR_NULL_POINTER);
3086 
3087   {
3088     jint result = (jint) mirror->identity_hash();
3089     *hash_code_ptr = result;
3090   }
3091   return JVMTI_ERROR_NONE;
3092 } /* end GetObjectHashCode */
3093 
3094 
3095 // info_ptr - pre-checked for null
3096 jvmtiError
3097 JvmtiEnv::GetObjectMonitorUsage(jobject object, jvmtiMonitorUsage* info_ptr) {
3098   // This needs to be performed at a safepoint to gather stable data
3099   // because monitor owner / waiters might not be suspended.
3100   VM_GetObjectMonitorUsage op(this, JavaThread::current(), object, info_ptr);
3101   VMThread::execute(&op);
3102   return op.result();
3103 } /* end GetObjectMonitorUsage */
3104 
3105 
3106   //
3107   // Field functions
3108   //
3109 
3110 // name_ptr - null is a valid value, must be checked
3111 // signature_ptr - null is a valid value, must be checked
3112 // generic_ptr - null is a valid value, must be checked
3113 jvmtiError
3114 JvmtiEnv::GetFieldName(fieldDescriptor* fdesc_ptr, char** name_ptr, char** signature_ptr, char** generic_ptr) {
3115   JavaThread* current_thread  = JavaThread::current();
3116   ResourceMark rm(current_thread);
3117   if (name_ptr == nullptr) {
3118     // just don't return the name
3119   } else {
3120     const char* fieldName = fdesc_ptr->name()->as_C_string();
3121     *name_ptr =  (char*) jvmtiMalloc(strlen(fieldName) + 1);
3122     if (*name_ptr == nullptr)
3123       return JVMTI_ERROR_OUT_OF_MEMORY;
3124     strcpy(*name_ptr, fieldName);
3125   }
3126   if (signature_ptr== nullptr) {
3127     // just don't return the signature
3128   } else {
3129     const char* fieldSignature = fdesc_ptr->signature()->as_C_string();
3130     *signature_ptr = (char*) jvmtiMalloc(strlen(fieldSignature) + 1);
3131     if (*signature_ptr == nullptr)
3132       return JVMTI_ERROR_OUT_OF_MEMORY;
3133     strcpy(*signature_ptr, fieldSignature);
3134   }
3135   if (generic_ptr != nullptr) {
3136     *generic_ptr = nullptr;
3137     Symbol* soop = fdesc_ptr->generic_signature();
3138     if (soop != nullptr) {
3139       const char* gen_sig = soop->as_C_string();
3140       if (gen_sig != nullptr) {
3141         jvmtiError err = allocate(strlen(gen_sig) + 1, (unsigned char **)generic_ptr);
3142         if (err != JVMTI_ERROR_NONE) {
3143           return err;
3144         }
3145         strcpy(*generic_ptr, gen_sig);
3146       }
3147     }
3148   }
3149   return JVMTI_ERROR_NONE;
3150 } /* end GetFieldName */
3151 
3152 
3153 // declaring_class_ptr - pre-checked for null
3154 jvmtiError
3155 JvmtiEnv::GetFieldDeclaringClass(fieldDescriptor* fdesc_ptr, jclass* declaring_class_ptr) {
3156   // As for the GetFieldDeclaringClass method, the XSL generated C++ code that calls it has
3157   // a jclass of the relevant class or a subclass of it, which is fine in terms of ensuring
3158   // the holder is kept alive.
3159   *declaring_class_ptr = get_jni_class_non_null(fdesc_ptr->field_holder());
3160   return JVMTI_ERROR_NONE;
3161 } /* end GetFieldDeclaringClass */
3162 
3163 
3164 // modifiers_ptr - pre-checked for null
3165 jvmtiError
3166 JvmtiEnv::GetFieldModifiers(fieldDescriptor* fdesc_ptr, jint* modifiers_ptr) {
3167 
3168   AccessFlags resultFlags = fdesc_ptr->access_flags();
3169   jint result = resultFlags.as_field_flags();
3170   *modifiers_ptr = result;
3171 
3172   return JVMTI_ERROR_NONE;
3173 } /* end GetFieldModifiers */
3174 
3175 
3176 // is_synthetic_ptr - pre-checked for null
3177 jvmtiError
3178 JvmtiEnv::IsFieldSynthetic(fieldDescriptor* fdesc_ptr, jboolean* is_synthetic_ptr) {
3179   *is_synthetic_ptr = fdesc_ptr->is_synthetic();
3180   return JVMTI_ERROR_NONE;
3181 } /* end IsFieldSynthetic */
3182 
3183 
3184   //
3185   // Method functions
3186   //
3187 
3188 // method - pre-checked for validity, but may be null meaning obsolete method
3189 // name_ptr - null is a valid value, must be checked
3190 // signature_ptr - null is a valid value, must be checked
3191 // generic_ptr - null is a valid value, must be checked
3192 jvmtiError
3193 JvmtiEnv::GetMethodName(Method* method, char** name_ptr, char** signature_ptr, char** generic_ptr) {
3194   NULL_CHECK(method, JVMTI_ERROR_INVALID_METHODID);
3195   JavaThread* current_thread  = JavaThread::current();
3196 
3197   ResourceMark rm(current_thread); // get the utf8 name and signature
3198   if (name_ptr == nullptr) {
3199     // just don't return the name
3200   } else {
3201     const char* utf8_name = (const char *) method->name()->as_utf8();
3202     *name_ptr = (char *) jvmtiMalloc(strlen(utf8_name)+1);
3203     strcpy(*name_ptr, utf8_name);
3204   }
3205   if (signature_ptr == nullptr) {
3206     // just don't return the signature
3207   } else {
3208     const char* utf8_signature = (const char *) method->signature()->as_utf8();
3209     *signature_ptr = (char *) jvmtiMalloc(strlen(utf8_signature) + 1);
3210     strcpy(*signature_ptr, utf8_signature);
3211   }
3212 
3213   if (generic_ptr != nullptr) {
3214     *generic_ptr = nullptr;
3215     Symbol* soop = method->generic_signature();
3216     if (soop != nullptr) {
3217       const char* gen_sig = soop->as_C_string();
3218       if (gen_sig != nullptr) {
3219         jvmtiError err = allocate(strlen(gen_sig) + 1, (unsigned char **)generic_ptr);
3220         if (err != JVMTI_ERROR_NONE) {
3221           return err;
3222         }
3223         strcpy(*generic_ptr, gen_sig);
3224       }
3225     }
3226   }
3227   return JVMTI_ERROR_NONE;
3228 } /* end GetMethodName */
3229 
3230 
3231 // method - pre-checked for validity, but may be null meaning obsolete method
3232 // declaring_class_ptr - pre-checked for null
3233 jvmtiError
3234 JvmtiEnv::GetMethodDeclaringClass(Method* method, jclass* declaring_class_ptr) {
3235   NULL_CHECK(method, JVMTI_ERROR_INVALID_METHODID);
3236   Klass* k = method->method_holder();
3237   Handle holder(Thread::current(), k->klass_holder()); // keep the klass alive
3238   (*declaring_class_ptr) = get_jni_class_non_null(k);
3239   return JVMTI_ERROR_NONE;
3240 } /* end GetMethodDeclaringClass */
3241 
3242 
3243 // method - pre-checked for validity, but may be null meaning obsolete method
3244 // modifiers_ptr - pre-checked for null
3245 jvmtiError
3246 JvmtiEnv::GetMethodModifiers(Method* method, jint* modifiers_ptr) {
3247   NULL_CHECK(method, JVMTI_ERROR_INVALID_METHODID);
3248   (*modifiers_ptr) = method->access_flags().as_method_flags();
3249   return JVMTI_ERROR_NONE;
3250 } /* end GetMethodModifiers */
3251 
3252 
3253 // method - pre-checked for validity, but may be null meaning obsolete method
3254 // max_ptr - pre-checked for null
3255 jvmtiError
3256 JvmtiEnv::GetMaxLocals(Method* method, jint* max_ptr) {
3257   NULL_CHECK(method, JVMTI_ERROR_INVALID_METHODID);
3258   // get max stack
3259   (*max_ptr) = method->max_locals();
3260   return JVMTI_ERROR_NONE;
3261 } /* end GetMaxLocals */
3262 
3263 
3264 // method - pre-checked for validity, but may be null meaning obsolete method
3265 // size_ptr - pre-checked for null
3266 jvmtiError
3267 JvmtiEnv::GetArgumentsSize(Method* method, jint* size_ptr) {
3268   NULL_CHECK(method, JVMTI_ERROR_INVALID_METHODID);
3269   // get size of arguments
3270 
3271   (*size_ptr) = method->size_of_parameters();
3272   return JVMTI_ERROR_NONE;
3273 } /* end GetArgumentsSize */
3274 
3275 
3276 // method - pre-checked for validity, but may be null meaning obsolete method
3277 // entry_count_ptr - pre-checked for null
3278 // table_ptr - pre-checked for null
3279 jvmtiError
3280 JvmtiEnv::GetLineNumberTable(Method* method, jint* entry_count_ptr, jvmtiLineNumberEntry** table_ptr) {
3281   NULL_CHECK(method, JVMTI_ERROR_INVALID_METHODID);
3282   if (!method->has_linenumber_table()) {
3283     return (JVMTI_ERROR_ABSENT_INFORMATION);
3284   }
3285 
3286   // The line number table is compressed so we don't know how big it is until decompressed.
3287   // Decompression is really fast so we just do it twice.
3288 
3289   // Compute size of table
3290   jint num_entries = 0;
3291   CompressedLineNumberReadStream stream(method->compressed_linenumber_table());
3292   while (stream.read_pair()) {
3293     num_entries++;
3294   }
3295   jvmtiLineNumberEntry *jvmti_table =
3296             (jvmtiLineNumberEntry *)jvmtiMalloc(num_entries * (sizeof(jvmtiLineNumberEntry)));
3297 
3298   // Fill jvmti table
3299   if (num_entries > 0) {
3300     int index = 0;
3301     CompressedLineNumberReadStream stream(method->compressed_linenumber_table());
3302     while (stream.read_pair()) {
3303       jvmti_table[index].start_location = (jlocation) stream.bci();
3304       jvmti_table[index].line_number = (jint) stream.line();
3305       index++;
3306     }
3307     assert(index == num_entries, "sanity check");
3308   }
3309 
3310   // Set up results
3311   (*entry_count_ptr) = num_entries;
3312   (*table_ptr) = jvmti_table;
3313 
3314   return JVMTI_ERROR_NONE;
3315 } /* end GetLineNumberTable */
3316 
3317 
3318 // method - pre-checked for validity, but may be null meaning obsolete method
3319 // start_location_ptr - pre-checked for null
3320 // end_location_ptr - pre-checked for null
3321 jvmtiError
3322 JvmtiEnv::GetMethodLocation(Method* method, jlocation* start_location_ptr, jlocation* end_location_ptr) {
3323 
3324   NULL_CHECK(method, JVMTI_ERROR_INVALID_METHODID);
3325   // get start and end location
3326   (*end_location_ptr) = (jlocation) (method->code_size() - 1);
3327   if (method->code_size() == 0) {
3328     // there is no code so there is no start location
3329     (*start_location_ptr) = (jlocation)(-1);
3330   } else {
3331     (*start_location_ptr) = (jlocation)(0);
3332   }
3333 
3334   return JVMTI_ERROR_NONE;
3335 } /* end GetMethodLocation */
3336 
3337 
3338 // method - pre-checked for validity, but may be null meaning obsolete method
3339 // entry_count_ptr - pre-checked for null
3340 // table_ptr - pre-checked for null
3341 jvmtiError
3342 JvmtiEnv::GetLocalVariableTable(Method* method, jint* entry_count_ptr, jvmtiLocalVariableEntry** table_ptr) {
3343 
3344   NULL_CHECK(method, JVMTI_ERROR_INVALID_METHODID);
3345   JavaThread* current_thread  = JavaThread::current();
3346 
3347   // does the klass have any local variable information?
3348   InstanceKlass* ik = method->method_holder();
3349   if (!ik->has_localvariable_table()) {
3350     return (JVMTI_ERROR_ABSENT_INFORMATION);
3351   }
3352 
3353   ConstantPool* constants = method->constants();
3354   NULL_CHECK(constants, JVMTI_ERROR_ABSENT_INFORMATION);
3355 
3356   // in the vm localvariable table representation, 6 consecutive elements in the table
3357   // represent a 6-tuple of shorts
3358   // [start_pc, length, name_index, descriptor_index, signature_index, index]
3359   jint num_entries = method->localvariable_table_length();
3360   jvmtiLocalVariableEntry *jvmti_table = (jvmtiLocalVariableEntry *)
3361                 jvmtiMalloc(num_entries * (sizeof(jvmtiLocalVariableEntry)));
3362 
3363   if (num_entries > 0) {
3364     LocalVariableTableElement* table = method->localvariable_table_start();
3365     for (int i = 0; i < num_entries; i++) {
3366       // get the 5 tuple information from the vm table
3367       jlocation start_location = (jlocation) table[i].start_bci;
3368       jint length = (jint) table[i].length;
3369       int name_index = (int) table[i].name_cp_index;
3370       int signature_index = (int) table[i].descriptor_cp_index;
3371       int generic_signature_index = (int) table[i].signature_cp_index;
3372       jint slot = (jint) table[i].slot;
3373 
3374       // get utf8 name and signature
3375       char *name_buf = nullptr;
3376       char *sig_buf = nullptr;
3377       char *gen_sig_buf = nullptr;
3378       {
3379         ResourceMark rm(current_thread);
3380 
3381         const char *utf8_name = (const char *) constants->symbol_at(name_index)->as_utf8();
3382         name_buf = (char *) jvmtiMalloc(strlen(utf8_name)+1);
3383         strcpy(name_buf, utf8_name);
3384 
3385         const char *utf8_signature = (const char *) constants->symbol_at(signature_index)->as_utf8();
3386         sig_buf = (char *) jvmtiMalloc(strlen(utf8_signature)+1);
3387         strcpy(sig_buf, utf8_signature);
3388 
3389         if (generic_signature_index > 0) {
3390           const char *utf8_gen_sign = (const char *)
3391                                        constants->symbol_at(generic_signature_index)->as_utf8();
3392           gen_sig_buf = (char *) jvmtiMalloc(strlen(utf8_gen_sign)+1);
3393           strcpy(gen_sig_buf, utf8_gen_sign);
3394         }
3395       }
3396 
3397       // fill in the jvmti local variable table
3398       jvmti_table[i].start_location = start_location;
3399       jvmti_table[i].length = length;
3400       jvmti_table[i].name = name_buf;
3401       jvmti_table[i].signature = sig_buf;
3402       jvmti_table[i].generic_signature = gen_sig_buf;
3403       jvmti_table[i].slot = slot;
3404     }
3405   }
3406 
3407   // set results
3408   (*entry_count_ptr) = num_entries;
3409   (*table_ptr) = jvmti_table;
3410 
3411   return JVMTI_ERROR_NONE;
3412 } /* end GetLocalVariableTable */
3413 
3414 
3415 // method - pre-checked for validity, but may be null meaning obsolete method
3416 // bytecode_count_ptr - pre-checked for null
3417 // bytecodes_ptr - pre-checked for null
3418 jvmtiError
3419 JvmtiEnv::GetBytecodes(Method* method, jint* bytecode_count_ptr, unsigned char** bytecodes_ptr) {
3420   NULL_CHECK(method, JVMTI_ERROR_INVALID_METHODID);
3421 
3422   JavaThread* current_thread = JavaThread::current();
3423   methodHandle mh(current_thread, method);
3424   jint size = (jint)mh->code_size();
3425   jvmtiError err = allocate(size, bytecodes_ptr);
3426   if (err != JVMTI_ERROR_NONE) {
3427     return err;
3428   }
3429 
3430   (*bytecode_count_ptr) = size;
3431   // get byte codes
3432   // Make sure the class is verified and rewritten first.
3433   JavaThread* THREAD = current_thread;
3434   mh->method_holder()->link_class(THREAD);
3435   if (HAS_PENDING_EXCEPTION) {
3436     CLEAR_PENDING_EXCEPTION;
3437     return JVMTI_ERROR_INVALID_CLASS;
3438   }
3439   JvmtiClassFileReconstituter::copy_bytecodes(mh, *bytecodes_ptr);
3440 
3441   return JVMTI_ERROR_NONE;
3442 } /* end GetBytecodes */
3443 
3444 
3445 // method - pre-checked for validity, but may be null meaning obsolete method
3446 // is_native_ptr - pre-checked for null
3447 jvmtiError
3448 JvmtiEnv::IsMethodNative(Method* method, jboolean* is_native_ptr) {
3449   NULL_CHECK(method, JVMTI_ERROR_INVALID_METHODID);
3450   (*is_native_ptr) = method->is_native();
3451   return JVMTI_ERROR_NONE;
3452 } /* end IsMethodNative */
3453 
3454 
3455 // method - pre-checked for validity, but may be null meaning obsolete method
3456 // is_synthetic_ptr - pre-checked for null
3457 jvmtiError
3458 JvmtiEnv::IsMethodSynthetic(Method* method, jboolean* is_synthetic_ptr) {
3459   NULL_CHECK(method, JVMTI_ERROR_INVALID_METHODID);
3460   (*is_synthetic_ptr) = method->is_synthetic();
3461   return JVMTI_ERROR_NONE;
3462 } /* end IsMethodSynthetic */
3463 
3464 
3465 // method - pre-checked for validity, but may be null meaning obsolete method
3466 // is_obsolete_ptr - pre-checked for null
3467 jvmtiError
3468 JvmtiEnv::IsMethodObsolete(Method* method, jboolean* is_obsolete_ptr) {
3469   if (use_version_1_0_semantics() &&
3470       get_capabilities()->can_redefine_classes == 0) {
3471     // This JvmtiEnv requested version 1.0 semantics and this function
3472     // requires the can_redefine_classes capability in version 1.0 so
3473     // we need to return an error here.
3474     return JVMTI_ERROR_MUST_POSSESS_CAPABILITY;
3475   }
3476 
3477   if (method == nullptr || method->is_obsolete()) {
3478     *is_obsolete_ptr = true;
3479   } else {
3480     *is_obsolete_ptr = false;
3481   }
3482   return JVMTI_ERROR_NONE;
3483 } /* end IsMethodObsolete */
3484 
3485   //
3486   // Raw Monitor functions
3487   //
3488 
3489 // name - pre-checked for null
3490 // monitor_ptr - pre-checked for null
3491 jvmtiError
3492 JvmtiEnv::CreateRawMonitor(const char* name, jrawMonitorID* monitor_ptr) {
3493   JvmtiRawMonitor* rmonitor = new (std::nothrow) JvmtiRawMonitor(name);
3494   NULL_CHECK(rmonitor, JVMTI_ERROR_OUT_OF_MEMORY);
3495 
3496   *monitor_ptr = (jrawMonitorID)rmonitor;
3497 
3498   return JVMTI_ERROR_NONE;
3499 } /* end CreateRawMonitor */
3500 
3501 
3502 // rmonitor - pre-checked for validity
3503 jvmtiError
3504 JvmtiEnv::DestroyRawMonitor(JvmtiRawMonitor * rmonitor) {
3505   if (Threads::number_of_threads() == 0) {
3506     // Remove this monitor from pending raw monitors list
3507     // if it has entered in onload or start phase.
3508     JvmtiPendingMonitors::destroy(rmonitor);
3509   } else {
3510     Thread* thread  = Thread::current();
3511     if (rmonitor->owner() == thread) {
3512       // The caller owns this monitor which we are about to destroy.
3513       // We exit the underlying synchronization object so that the
3514       // "delete monitor" call below can work without an assertion
3515       // failure on systems that don't like destroying synchronization
3516       // objects that are locked.
3517       int r;
3518       int recursion = rmonitor->recursions();
3519       for (int i = 0; i <= recursion; i++) {
3520         r = rmonitor->raw_exit(thread);
3521         assert(r == JvmtiRawMonitor::M_OK, "raw_exit should have worked");
3522         if (r != JvmtiRawMonitor::M_OK) {  // robustness
3523           return JVMTI_ERROR_INTERNAL;
3524         }
3525       }
3526     }
3527     if (rmonitor->owner() != nullptr) {
3528       // The caller is trying to destroy a monitor that is locked by
3529       // someone else. While this is not forbidden by the JVMTI
3530       // spec, it will cause an assertion failure on systems that don't
3531       // like destroying synchronization objects that are locked.
3532       // We indicate a problem with the error return (and leak the
3533       // monitor's memory).
3534       return JVMTI_ERROR_NOT_MONITOR_OWNER;
3535     }
3536   }
3537 
3538   delete rmonitor;
3539 
3540   return JVMTI_ERROR_NONE;
3541 } /* end DestroyRawMonitor */
3542 
3543 
3544 // rmonitor - pre-checked for validity
3545 jvmtiError
3546 JvmtiEnv::RawMonitorEnter(JvmtiRawMonitor * rmonitor) {
3547   if (Threads::number_of_threads() == 0) {
3548     // No JavaThreads exist so JvmtiRawMonitor enter cannot be
3549     // used, add this raw monitor to the pending list.
3550     // The pending monitors will be actually entered when
3551     // the VM is setup.
3552     // See transition_pending_raw_monitors in create_vm()
3553     // in thread.cpp.
3554     JvmtiPendingMonitors::enter(rmonitor);
3555   } else {
3556     Thread* thread = Thread::current();
3557     // 8266889: raw_enter changes Java thread state, needs WXWrite
3558     MACOS_AARCH64_ONLY(ThreadWXEnable __wx(WXWrite, thread));
3559     rmonitor->raw_enter(thread);
3560   }
3561   return JVMTI_ERROR_NONE;
3562 } /* end RawMonitorEnter */
3563 
3564 
3565 // rmonitor - pre-checked for validity
3566 jvmtiError
3567 JvmtiEnv::RawMonitorExit(JvmtiRawMonitor * rmonitor) {
3568   jvmtiError err = JVMTI_ERROR_NONE;
3569 
3570   if (Threads::number_of_threads() == 0) {
3571     // No JavaThreads exist so just remove this monitor from the pending list.
3572     // Bool value from exit is false if rmonitor is not in the list.
3573     if (!JvmtiPendingMonitors::exit(rmonitor)) {
3574       err = JVMTI_ERROR_NOT_MONITOR_OWNER;
3575     }
3576   } else {
3577     Thread* thread = Thread::current();
3578     int r = rmonitor->raw_exit(thread);
3579     if (r == JvmtiRawMonitor::M_ILLEGAL_MONITOR_STATE) {
3580       err = JVMTI_ERROR_NOT_MONITOR_OWNER;
3581     }
3582   }
3583   return err;
3584 } /* end RawMonitorExit */
3585 
3586 
3587 // rmonitor - pre-checked for validity
3588 jvmtiError
3589 JvmtiEnv::RawMonitorWait(JvmtiRawMonitor * rmonitor, jlong millis) {
3590   Thread* thread = Thread::current();
3591   // 8266889: raw_wait changes Java thread state, needs WXWrite
3592   MACOS_AARCH64_ONLY(ThreadWXEnable __wx(WXWrite, thread));
3593   int r = rmonitor->raw_wait(millis, thread);
3594 
3595   switch (r) {
3596   case JvmtiRawMonitor::M_INTERRUPTED:
3597     return JVMTI_ERROR_INTERRUPT;
3598   case JvmtiRawMonitor::M_ILLEGAL_MONITOR_STATE:
3599     return JVMTI_ERROR_NOT_MONITOR_OWNER;
3600   default:
3601     return JVMTI_ERROR_NONE;
3602   }
3603 } /* end RawMonitorWait */
3604 
3605 
3606 // rmonitor - pre-checked for validity
3607 jvmtiError
3608 JvmtiEnv::RawMonitorNotify(JvmtiRawMonitor * rmonitor) {
3609   Thread* thread = Thread::current();
3610   int r = rmonitor->raw_notify(thread);
3611 
3612   if (r == JvmtiRawMonitor::M_ILLEGAL_MONITOR_STATE) {
3613     return JVMTI_ERROR_NOT_MONITOR_OWNER;
3614   }
3615   return JVMTI_ERROR_NONE;
3616 } /* end RawMonitorNotify */
3617 
3618 
3619 // rmonitor - pre-checked for validity
3620 jvmtiError
3621 JvmtiEnv::RawMonitorNotifyAll(JvmtiRawMonitor * rmonitor) {
3622   Thread* thread = Thread::current();
3623   int r = rmonitor->raw_notifyAll(thread);
3624 
3625   if (r == JvmtiRawMonitor::M_ILLEGAL_MONITOR_STATE) {
3626     return JVMTI_ERROR_NOT_MONITOR_OWNER;
3627   }
3628   return JVMTI_ERROR_NONE;
3629 } /* end RawMonitorNotifyAll */
3630 
3631 
3632   //
3633   // JNI Function Interception functions
3634   //
3635 
3636 
3637 // function_table - pre-checked for null
3638 jvmtiError
3639 JvmtiEnv::SetJNIFunctionTable(const jniNativeInterface* function_table) {
3640   // Copy jni function table at safepoint.
3641   VM_JNIFunctionTableCopier copier(function_table);
3642   VMThread::execute(&copier);
3643 
3644   return JVMTI_ERROR_NONE;
3645 } /* end SetJNIFunctionTable */
3646 
3647 
3648 // function_table - pre-checked for null
3649 jvmtiError
3650 JvmtiEnv::GetJNIFunctionTable(jniNativeInterface** function_table) {
3651   *function_table=(jniNativeInterface*)jvmtiMalloc(sizeof(jniNativeInterface));
3652   if (*function_table == nullptr)
3653     return JVMTI_ERROR_OUT_OF_MEMORY;
3654   memcpy(*function_table,(JavaThread::current())->get_jni_functions(),sizeof(jniNativeInterface));
3655   return JVMTI_ERROR_NONE;
3656 } /* end GetJNIFunctionTable */
3657 
3658 
3659   //
3660   // Event Management functions
3661   //
3662 
3663 jvmtiError
3664 JvmtiEnv::GenerateEvents(jvmtiEvent event_type) {
3665   // can only generate two event types
3666   if (event_type != JVMTI_EVENT_COMPILED_METHOD_LOAD &&
3667       event_type != JVMTI_EVENT_DYNAMIC_CODE_GENERATED) {
3668     return JVMTI_ERROR_ILLEGAL_ARGUMENT;
3669   }
3670 
3671   // for compiled_method_load events we must check that the environment
3672   // has the can_generate_compiled_method_load_events capability.
3673   if (event_type == JVMTI_EVENT_COMPILED_METHOD_LOAD) {
3674     if (get_capabilities()->can_generate_compiled_method_load_events == 0) {
3675       return JVMTI_ERROR_MUST_POSSESS_CAPABILITY;
3676     }
3677     return JvmtiCodeBlobEvents::generate_compiled_method_load_events(this);
3678   } else {
3679     return JvmtiCodeBlobEvents::generate_dynamic_code_events(this);
3680   }
3681 
3682 } /* end GenerateEvents */
3683 
3684 
3685   //
3686   // Extension Mechanism functions
3687   //
3688 
3689 // extension_count_ptr - pre-checked for null
3690 // extensions - pre-checked for null
3691 jvmtiError
3692 JvmtiEnv::GetExtensionFunctions(jint* extension_count_ptr, jvmtiExtensionFunctionInfo** extensions) {
3693   return JvmtiExtensions::get_functions(this, extension_count_ptr, extensions);
3694 } /* end GetExtensionFunctions */
3695 
3696 
3697 // extension_count_ptr - pre-checked for null
3698 // extensions - pre-checked for null
3699 jvmtiError
3700 JvmtiEnv::GetExtensionEvents(jint* extension_count_ptr, jvmtiExtensionEventInfo** extensions) {
3701   return JvmtiExtensions::get_events(this, extension_count_ptr, extensions);
3702 } /* end GetExtensionEvents */
3703 
3704 
3705 // callback - null is a valid value, must be checked
3706 jvmtiError
3707 JvmtiEnv::SetExtensionEventCallback(jint extension_event_index, jvmtiExtensionEvent callback) {
3708   return JvmtiExtensions::set_event_callback(this, extension_event_index, callback);
3709 } /* end SetExtensionEventCallback */
3710 
3711   //
3712   // Timers functions
3713   //
3714 
3715 // info_ptr - pre-checked for null
3716 jvmtiError
3717 JvmtiEnv::GetCurrentThreadCpuTimerInfo(jvmtiTimerInfo* info_ptr) {
3718   os::current_thread_cpu_time_info(info_ptr);
3719   return JVMTI_ERROR_NONE;
3720 } /* end GetCurrentThreadCpuTimerInfo */
3721 
3722 
3723 // nanos_ptr - pre-checked for null
3724 jvmtiError
3725 JvmtiEnv::GetCurrentThreadCpuTime(jlong* nanos_ptr) {
3726   Thread* thread = Thread::current();
3727 
3728   // Surprisingly the GetCurrentThreadCpuTime is used by non-JavaThread's.
3729   if (thread->is_Java_thread()) {
3730     if (JavaThread::cast(thread)->is_vthread_mounted()) {
3731       // No support for a VirtualThread (yet).
3732       return JVMTI_ERROR_UNSUPPORTED_OPERATION;
3733     }
3734   }
3735   *nanos_ptr = os::current_thread_cpu_time();
3736   return JVMTI_ERROR_NONE;
3737 } /* end GetCurrentThreadCpuTime */
3738 
3739 
3740 // info_ptr - pre-checked for null
3741 jvmtiError
3742 JvmtiEnv::GetThreadCpuTimerInfo(jvmtiTimerInfo* info_ptr) {
3743   os::thread_cpu_time_info(info_ptr);
3744   return JVMTI_ERROR_NONE;
3745 } /* end GetThreadCpuTimerInfo */
3746 
3747 
3748 // nanos_ptr - pre-checked for null
3749 jvmtiError
3750 JvmtiEnv::GetThreadCpuTime(jthread thread, jlong* nanos_ptr) {
3751   JavaThread* current_thread = JavaThread::current();
3752   ThreadsListHandle tlh(current_thread);
3753   JavaThread* java_thread = nullptr;
3754   oop thread_oop = nullptr;
3755 
3756   jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, current_thread, &java_thread, &thread_oop);
3757 
3758   if (thread_oop != nullptr && thread_oop->is_a(vmClasses::BaseVirtualThread_klass())) {
3759     // No support for virtual threads (yet).
3760     return JVMTI_ERROR_UNSUPPORTED_OPERATION;
3761   }
3762   if (err != JVMTI_ERROR_NONE) {
3763     return err;
3764   }
3765   NULL_CHECK(nanos_ptr, JVMTI_ERROR_NULL_POINTER);
3766 
3767   *nanos_ptr = os::thread_cpu_time(java_thread);
3768   return JVMTI_ERROR_NONE;
3769 } /* end GetThreadCpuTime */
3770 
3771 
3772 // info_ptr - pre-checked for null
3773 jvmtiError
3774 JvmtiEnv::GetTimerInfo(jvmtiTimerInfo* info_ptr) {
3775   os::javaTimeNanos_info(info_ptr);
3776   return JVMTI_ERROR_NONE;
3777 } /* end GetTimerInfo */
3778 
3779 
3780 // nanos_ptr - pre-checked for null
3781 jvmtiError
3782 JvmtiEnv::GetTime(jlong* nanos_ptr) {
3783   *nanos_ptr = os::javaTimeNanos();
3784   return JVMTI_ERROR_NONE;
3785 } /* end GetTime */
3786 
3787 
3788 // processor_count_ptr - pre-checked for null
3789 jvmtiError
3790 JvmtiEnv::GetAvailableProcessors(jint* processor_count_ptr) {
3791   *processor_count_ptr = os::active_processor_count();
3792   return JVMTI_ERROR_NONE;
3793 } /* end GetAvailableProcessors */
3794 
3795 jvmtiError
3796 JvmtiEnv::SetHeapSamplingInterval(jint sampling_interval) {
3797   if (sampling_interval < 0) {
3798     return JVMTI_ERROR_ILLEGAL_ARGUMENT;
3799   }
3800   ThreadHeapSampler::set_sampling_interval(sampling_interval);
3801   return JVMTI_ERROR_NONE;
3802 } /* end SetHeapSamplingInterval */
3803 
3804   //
3805   // System Properties functions
3806   //
3807 
3808 // count_ptr - pre-checked for null
3809 // property_ptr - pre-checked for null
3810 jvmtiError
3811 JvmtiEnv::GetSystemProperties(jint* count_ptr, char*** property_ptr) {
3812   jvmtiError err = JVMTI_ERROR_NONE;
3813 
3814   // Get the number of readable properties.
3815   *count_ptr = Arguments::PropertyList_readable_count(Arguments::system_properties());
3816 
3817   // Allocate memory to hold the exact number of readable properties.
3818   err = allocate(*count_ptr * sizeof(char *), (unsigned char **)property_ptr);
3819   if (err != JVMTI_ERROR_NONE) {
3820     return err;
3821   }
3822   int readable_count = 0;
3823   // Loop through the system properties until all the readable properties are found.
3824   for (SystemProperty* p = Arguments::system_properties(); p != nullptr && readable_count < *count_ptr; p = p->next()) {
3825     if (p->readable()) {
3826       const char *key = p->key();
3827       char **tmp_value = *property_ptr+readable_count;
3828       readable_count++;
3829       err = allocate((strlen(key)+1) * sizeof(char), (unsigned char**)tmp_value);
3830       if (err == JVMTI_ERROR_NONE) {
3831         strcpy(*tmp_value, key);
3832       } else {
3833         // clean up previously allocated memory.
3834         for (int j = 0; j < readable_count; j++) {
3835           Deallocate((unsigned char*)*property_ptr+j);
3836         }
3837         Deallocate((unsigned char*)property_ptr);
3838         break;
3839       }
3840     }
3841   }
3842   assert(err != JVMTI_ERROR_NONE || readable_count == *count_ptr, "Bad readable property count");
3843   return err;
3844 } /* end GetSystemProperties */
3845 
3846 
3847 // property - pre-checked for null
3848 // value_ptr - pre-checked for null
3849 jvmtiError
3850 JvmtiEnv::GetSystemProperty(const char* property, char** value_ptr) {
3851   jvmtiError err = JVMTI_ERROR_NONE;
3852   const char *value;
3853 
3854   // Return JVMTI_ERROR_NOT_AVAILABLE if property is not readable or doesn't exist.
3855   value = Arguments::PropertyList_get_readable_value(Arguments::system_properties(), property);
3856   if (value == nullptr) {
3857     err =  JVMTI_ERROR_NOT_AVAILABLE;
3858   } else {
3859     err = allocate((strlen(value)+1) * sizeof(char), (unsigned char **)value_ptr);
3860     if (err == JVMTI_ERROR_NONE) {
3861       strcpy(*value_ptr, value);
3862     }
3863   }
3864   return err;
3865 } /* end GetSystemProperty */
3866 
3867 
3868 // property - pre-checked for null
3869 // value - null is a valid value, must be checked
3870 jvmtiError
3871 JvmtiEnv::SetSystemProperty(const char* property, const char* value_ptr) {
3872   for (SystemProperty* p = Arguments::system_properties(); p != nullptr; p = p->next()) {
3873     if (strcmp(property, p->key()) == 0) {
3874       if (p->writeable()) {
3875         if (p->set_value(value_ptr, AllocFailStrategy::RETURN_NULL)) {
3876           return JVMTI_ERROR_NONE;
3877         } else {
3878           return JVMTI_ERROR_OUT_OF_MEMORY;
3879         }
3880       } else {
3881         // We found a property, but it's not writeable
3882         return JVMTI_ERROR_NOT_AVAILABLE;
3883       }
3884     }
3885   }
3886 
3887   // We cannot find a property of the given name
3888   return JVMTI_ERROR_NOT_AVAILABLE;
3889 } /* end SetSystemProperty */