1 /* 2 * Copyright (c) 2003, 2024, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "classfile/classLoaderDataGraph.hpp" 27 #include "classfile/javaClasses.inline.hpp" 28 #include "classfile/moduleEntry.hpp" 29 #include "classfile/symbolTable.hpp" 30 #include "classfile/vmSymbols.hpp" 31 #include "jvmtifiles/jvmtiEnv.hpp" 32 #include "memory/iterator.hpp" 33 #include "memory/resourceArea.hpp" 34 #include "oops/klass.inline.hpp" 35 #include "oops/objArrayKlass.hpp" 36 #include "oops/objArrayOop.hpp" 37 #include "oops/oop.inline.hpp" 38 #include "oops/oopHandle.inline.hpp" 39 #include "prims/jvmtiEnvBase.hpp" 40 #include "prims/jvmtiEventController.inline.hpp" 41 #include "prims/jvmtiExtensions.hpp" 42 #include "prims/jvmtiImpl.hpp" 43 #include "prims/jvmtiManageCapabilities.hpp" 44 #include "prims/jvmtiTagMap.hpp" 45 #include "prims/jvmtiThreadState.inline.hpp" 46 #include "runtime/continuationEntry.inline.hpp" 47 #include "runtime/deoptimization.hpp" 48 #include "runtime/frame.inline.hpp" 49 #include "runtime/handles.inline.hpp" 50 #include "runtime/interfaceSupport.inline.hpp" 51 #include "runtime/javaCalls.hpp" 52 #include "runtime/javaThread.inline.hpp" 53 #include "runtime/jfieldIDWorkaround.hpp" 54 #include "runtime/jniHandles.inline.hpp" 55 #include "runtime/objectMonitor.inline.hpp" 56 #include "runtime/osThread.hpp" 57 #include "runtime/signature.hpp" 58 #include "runtime/stackWatermarkSet.inline.hpp" 59 #include "runtime/threads.hpp" 60 #include "runtime/threadSMR.inline.hpp" 61 #include "runtime/vframe.inline.hpp" 62 #include "runtime/vframe_hp.hpp" 63 #include "runtime/vmThread.hpp" 64 #include "runtime/vmOperations.hpp" 65 #include "services/threadService.hpp" 66 67 68 /////////////////////////////////////////////////////////////// 69 // 70 // JvmtiEnvBase 71 // 72 73 JvmtiEnvBase* JvmtiEnvBase::_head_environment = nullptr; 74 75 bool JvmtiEnvBase::_globally_initialized = false; 76 volatile bool JvmtiEnvBase::_needs_clean_up = false; 77 78 jvmtiPhase JvmtiEnvBase::_phase = JVMTI_PHASE_PRIMORDIAL; 79 80 volatile int JvmtiEnvBase::_dying_thread_env_iteration_count = 0; 81 82 extern jvmtiInterface_1_ jvmti_Interface; 83 extern jvmtiInterface_1_ jvmtiTrace_Interface; 84 85 86 // perform initializations that must occur before any JVMTI environments 87 // are released but which should only be initialized once (no matter 88 // how many environments are created). 89 void 90 JvmtiEnvBase::globally_initialize() { 91 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check"); 92 assert(_globally_initialized == false, "bad call"); 93 94 JvmtiManageCapabilities::initialize(); 95 96 // register extension functions and events 97 JvmtiExtensions::register_extensions(); 98 99 #ifdef JVMTI_TRACE 100 JvmtiTrace::initialize(); 101 #endif 102 103 _globally_initialized = true; 104 } 105 106 107 void 108 JvmtiEnvBase::initialize() { 109 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check"); 110 111 // Add this environment to the end of the environment list (order is important) 112 { 113 // This block of code must not contain any safepoints, as list deallocation 114 // (which occurs at a safepoint) cannot occur simultaneously with this list 115 // addition. Note: NoSafepointVerifier cannot, currently, be used before 116 // threads exist. 117 JvmtiEnvIterator it; 118 JvmtiEnvBase *previous_env = nullptr; 119 for (JvmtiEnvBase* env = it.first(); env != nullptr; env = it.next(env)) { 120 previous_env = env; 121 } 122 if (previous_env == nullptr) { 123 _head_environment = this; 124 } else { 125 previous_env->set_next_environment(this); 126 } 127 } 128 129 if (_globally_initialized == false) { 130 globally_initialize(); 131 } 132 } 133 134 jvmtiPhase 135 JvmtiEnvBase::phase() { 136 // For the JVMTI environments possessed the can_generate_early_vmstart: 137 // replace JVMTI_PHASE_PRIMORDIAL with JVMTI_PHASE_START 138 if (_phase == JVMTI_PHASE_PRIMORDIAL && 139 JvmtiExport::early_vmstart_recorded() && 140 early_vmstart_env()) { 141 return JVMTI_PHASE_START; 142 } 143 return _phase; // Normal case 144 } 145 146 bool 147 JvmtiEnvBase::is_valid() { 148 jlong value = 0; 149 150 // This object might not be a JvmtiEnvBase so we can't assume 151 // the _magic field is properly aligned. Get the value in a safe 152 // way and then check against JVMTI_MAGIC. 153 154 switch (sizeof(_magic)) { 155 case 2: 156 value = Bytes::get_native_u2((address)&_magic); 157 break; 158 159 case 4: 160 value = Bytes::get_native_u4((address)&_magic); 161 break; 162 163 case 8: 164 value = Bytes::get_native_u8((address)&_magic); 165 break; 166 167 default: 168 guarantee(false, "_magic field is an unexpected size"); 169 } 170 171 return value == JVMTI_MAGIC; 172 } 173 174 175 bool 176 JvmtiEnvBase::use_version_1_0_semantics() { 177 int major, minor, micro; 178 179 JvmtiExport::decode_version_values(_version, &major, &minor, µ); 180 return major == 1 && minor == 0; // micro version doesn't matter here 181 } 182 183 184 bool 185 JvmtiEnvBase::use_version_1_1_semantics() { 186 int major, minor, micro; 187 188 JvmtiExport::decode_version_values(_version, &major, &minor, µ); 189 return major == 1 && minor == 1; // micro version doesn't matter here 190 } 191 192 bool 193 JvmtiEnvBase::use_version_1_2_semantics() { 194 int major, minor, micro; 195 196 JvmtiExport::decode_version_values(_version, &major, &minor, µ); 197 return major == 1 && minor == 2; // micro version doesn't matter here 198 } 199 200 201 JvmtiEnvBase::JvmtiEnvBase(jint version) : _env_event_enable() { 202 _version = version; 203 _env_local_storage = nullptr; 204 _tag_map = nullptr; 205 _native_method_prefix_count = 0; 206 _native_method_prefixes = nullptr; 207 _next = nullptr; 208 _class_file_load_hook_ever_enabled = false; 209 210 // Moot since ClassFileLoadHook not yet enabled. 211 // But "true" will give a more predictable ClassFileLoadHook behavior 212 // for environment creation during ClassFileLoadHook. 213 _is_retransformable = true; 214 215 // all callbacks initially null 216 memset(&_event_callbacks, 0, sizeof(jvmtiEventCallbacks)); 217 memset(&_ext_event_callbacks, 0, sizeof(jvmtiExtEventCallbacks)); 218 219 // all capabilities initially off 220 memset(&_current_capabilities, 0, sizeof(_current_capabilities)); 221 222 // all prohibited capabilities initially off 223 memset(&_prohibited_capabilities, 0, sizeof(_prohibited_capabilities)); 224 225 _magic = JVMTI_MAGIC; 226 227 JvmtiEventController::env_initialize((JvmtiEnv*)this); 228 229 #ifdef JVMTI_TRACE 230 _jvmti_external.functions = TraceJVMTI != nullptr ? &jvmtiTrace_Interface : &jvmti_Interface; 231 #else 232 _jvmti_external.functions = &jvmti_Interface; 233 #endif 234 } 235 236 237 void 238 JvmtiEnvBase::dispose() { 239 240 #ifdef JVMTI_TRACE 241 JvmtiTrace::shutdown(); 242 #endif 243 244 // Dispose of event info and let the event controller call us back 245 // in a locked state (env_dispose, below) 246 JvmtiEventController::env_dispose(this); 247 } 248 249 void 250 JvmtiEnvBase::env_dispose() { 251 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check"); 252 253 // We have been entered with all events disabled on this environment. 254 // A race to re-enable events (by setting callbacks) is prevented by 255 // checking for a valid environment when setting callbacks (while 256 // holding the JvmtiThreadState_lock). 257 258 // Mark as invalid. 259 _magic = DISPOSED_MAGIC; 260 261 // Relinquish all capabilities. 262 jvmtiCapabilities *caps = get_capabilities(); 263 JvmtiManageCapabilities::relinquish_capabilities(caps, caps, caps); 264 265 // Same situation as with events (see above) 266 set_native_method_prefixes(0, nullptr); 267 268 JvmtiTagMap* tag_map_to_clear = tag_map_acquire(); 269 // A tag map can be big, clear it now to save memory until 270 // the destructor runs. 271 if (tag_map_to_clear != nullptr) { 272 tag_map_to_clear->clear(); 273 } 274 275 _needs_clean_up = true; 276 } 277 278 279 JvmtiEnvBase::~JvmtiEnvBase() { 280 assert(SafepointSynchronize::is_at_safepoint(), "sanity check"); 281 282 // There is a small window of time during which the tag map of a 283 // disposed environment could have been reallocated. 284 // Make sure it is gone. 285 JvmtiTagMap* tag_map_to_deallocate = _tag_map; 286 set_tag_map(nullptr); 287 // A tag map can be big, deallocate it now 288 if (tag_map_to_deallocate != nullptr) { 289 delete tag_map_to_deallocate; 290 } 291 292 _magic = BAD_MAGIC; 293 } 294 295 296 void 297 JvmtiEnvBase::periodic_clean_up() { 298 assert(SafepointSynchronize::is_at_safepoint(), "sanity check"); 299 300 // JvmtiEnvBase reference is saved in JvmtiEnvThreadState. So 301 // clean up JvmtiThreadState before deleting JvmtiEnv pointer. 302 JvmtiThreadState::periodic_clean_up(); 303 304 // Unlink all invalid environments from the list of environments 305 // and deallocate them 306 JvmtiEnvIterator it; 307 JvmtiEnvBase* previous_env = nullptr; 308 JvmtiEnvBase* env = it.first(); 309 while (env != nullptr) { 310 if (env->is_valid()) { 311 previous_env = env; 312 env = it.next(env); 313 } else { 314 // This one isn't valid, remove it from the list and deallocate it 315 JvmtiEnvBase* defunct_env = env; 316 env = it.next(env); 317 if (previous_env == nullptr) { 318 _head_environment = env; 319 } else { 320 previous_env->set_next_environment(env); 321 } 322 delete defunct_env; 323 } 324 } 325 326 } 327 328 329 void 330 JvmtiEnvBase::check_for_periodic_clean_up() { 331 assert(SafepointSynchronize::is_at_safepoint(), "sanity check"); 332 333 class ThreadInsideIterationClosure: public ThreadClosure { 334 private: 335 bool _inside; 336 public: 337 ThreadInsideIterationClosure() : _inside(false) {}; 338 339 void do_thread(Thread* thread) { 340 _inside |= thread->is_inside_jvmti_env_iteration(); 341 } 342 343 bool is_inside_jvmti_env_iteration() { 344 return _inside; 345 } 346 }; 347 348 if (_needs_clean_up) { 349 // Check if we are currently iterating environment, 350 // deallocation should not occur if we are 351 ThreadInsideIterationClosure tiic; 352 Threads::threads_do(&tiic); 353 if (!tiic.is_inside_jvmti_env_iteration() && 354 !is_inside_dying_thread_env_iteration()) { 355 _needs_clean_up = false; 356 JvmtiEnvBase::periodic_clean_up(); 357 } 358 } 359 } 360 361 362 void 363 JvmtiEnvBase::record_first_time_class_file_load_hook_enabled() { 364 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), 365 "sanity check"); 366 367 if (!_class_file_load_hook_ever_enabled) { 368 _class_file_load_hook_ever_enabled = true; 369 370 if (get_capabilities()->can_retransform_classes) { 371 _is_retransformable = true; 372 } else { 373 _is_retransformable = false; 374 375 // cannot add retransform capability after ClassFileLoadHook has been enabled 376 get_prohibited_capabilities()->can_retransform_classes = 1; 377 } 378 } 379 } 380 381 382 void 383 JvmtiEnvBase::record_class_file_load_hook_enabled() { 384 if (!_class_file_load_hook_ever_enabled) { 385 if (Threads::number_of_threads() == 0) { 386 record_first_time_class_file_load_hook_enabled(); 387 } else { 388 MutexLocker mu(JvmtiThreadState_lock); 389 record_first_time_class_file_load_hook_enabled(); 390 } 391 } 392 } 393 394 395 jvmtiError 396 JvmtiEnvBase::set_native_method_prefixes(jint prefix_count, char** prefixes) { 397 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), 398 "sanity check"); 399 400 int old_prefix_count = get_native_method_prefix_count(); 401 char **old_prefixes = get_native_method_prefixes(); 402 403 // allocate and install the new prefixex 404 if (prefix_count == 0 || !is_valid()) { 405 _native_method_prefix_count = 0; 406 _native_method_prefixes = nullptr; 407 } else { 408 // there are prefixes, allocate an array to hold them, and fill it 409 char** new_prefixes = (char**)os::malloc((prefix_count) * sizeof(char*), mtInternal); 410 if (new_prefixes == nullptr) { 411 return JVMTI_ERROR_OUT_OF_MEMORY; 412 } 413 for (int i = 0; i < prefix_count; i++) { 414 char* prefix = prefixes[i]; 415 if (prefix == nullptr) { 416 for (int j = 0; j < (i-1); j++) { 417 os::free(new_prefixes[j]); 418 } 419 os::free(new_prefixes); 420 return JVMTI_ERROR_NULL_POINTER; 421 } 422 prefix = os::strdup(prefixes[i]); 423 if (prefix == nullptr) { 424 for (int j = 0; j < (i-1); j++) { 425 os::free(new_prefixes[j]); 426 } 427 os::free(new_prefixes); 428 return JVMTI_ERROR_OUT_OF_MEMORY; 429 } 430 new_prefixes[i] = prefix; 431 } 432 _native_method_prefix_count = prefix_count; 433 _native_method_prefixes = new_prefixes; 434 } 435 436 // now that we know the new prefixes have been successfully installed we can 437 // safely remove the old ones 438 if (old_prefix_count != 0) { 439 for (int i = 0; i < old_prefix_count; i++) { 440 os::free(old_prefixes[i]); 441 } 442 os::free(old_prefixes); 443 } 444 445 return JVMTI_ERROR_NONE; 446 } 447 448 449 // Collect all the prefixes which have been set in any JVM TI environments 450 // by the SetNativeMethodPrefix(es) functions. Be sure to maintain the 451 // order of environments and the order of prefixes within each environment. 452 // Return in a resource allocated array. 453 char** 454 JvmtiEnvBase::get_all_native_method_prefixes(int* count_ptr) { 455 assert(Threads::number_of_threads() == 0 || 456 SafepointSynchronize::is_at_safepoint() || 457 JvmtiThreadState_lock->is_locked(), 458 "sanity check"); 459 460 int total_count = 0; 461 GrowableArray<char*>* prefix_array =new GrowableArray<char*>(5); 462 463 JvmtiEnvIterator it; 464 for (JvmtiEnvBase* env = it.first(); env != nullptr; env = it.next(env)) { 465 int prefix_count = env->get_native_method_prefix_count(); 466 char** prefixes = env->get_native_method_prefixes(); 467 for (int j = 0; j < prefix_count; j++) { 468 // retrieve a prefix and so that it is safe against asynchronous changes 469 // copy it into the resource area 470 char* prefix = prefixes[j]; 471 char* prefix_copy = NEW_RESOURCE_ARRAY(char, strlen(prefix)+1); 472 strcpy(prefix_copy, prefix); 473 prefix_array->at_put_grow(total_count++, prefix_copy); 474 } 475 } 476 477 char** all_prefixes = NEW_RESOURCE_ARRAY(char*, total_count); 478 char** p = all_prefixes; 479 for (int i = 0; i < total_count; ++i) { 480 *p++ = prefix_array->at(i); 481 } 482 *count_ptr = total_count; 483 return all_prefixes; 484 } 485 486 void 487 JvmtiEnvBase::set_event_callbacks(const jvmtiEventCallbacks* callbacks, 488 jint size_of_callbacks) { 489 assert(Threads::number_of_threads() == 0 || JvmtiThreadState_lock->is_locked(), "sanity check"); 490 491 size_t byte_cnt = sizeof(jvmtiEventCallbacks); 492 493 // clear in either case to be sure we got any gap between sizes 494 memset(&_event_callbacks, 0, byte_cnt); 495 496 // Now that JvmtiThreadState_lock is held, prevent a possible race condition where events 497 // are re-enabled by a call to set event callbacks where the DisposeEnvironment 498 // occurs after the boiler-plate environment check and before the lock is acquired. 499 if (callbacks != nullptr && is_valid()) { 500 if (size_of_callbacks < (jint)byte_cnt) { 501 byte_cnt = size_of_callbacks; 502 } 503 memcpy(&_event_callbacks, callbacks, byte_cnt); 504 } 505 } 506 507 508 // In the fullness of time, all users of the method should instead 509 // directly use allocate, besides being cleaner and faster, this will 510 // mean much better out of memory handling 511 unsigned char * 512 JvmtiEnvBase::jvmtiMalloc(jlong size) { 513 unsigned char* mem = nullptr; 514 jvmtiError result = allocate(size, &mem); 515 assert(result == JVMTI_ERROR_NONE, "Allocate failed"); 516 return mem; 517 } 518 519 520 // Handle management 521 522 jobject JvmtiEnvBase::jni_reference(Handle hndl) { 523 return JNIHandles::make_local(hndl()); 524 } 525 526 jobject JvmtiEnvBase::jni_reference(JavaThread *thread, Handle hndl) { 527 return JNIHandles::make_local(thread, hndl()); 528 } 529 530 void JvmtiEnvBase::destroy_jni_reference(jobject jobj) { 531 JNIHandles::destroy_local(jobj); 532 } 533 534 void JvmtiEnvBase::destroy_jni_reference(JavaThread *thread, jobject jobj) { 535 JNIHandles::destroy_local(jobj); // thread is unused. 536 } 537 538 // 539 // Threads 540 // 541 542 jthread * 543 JvmtiEnvBase::new_jthreadArray(int length, Handle *handles) { 544 if (length == 0) { 545 return nullptr; 546 } 547 548 jthread* objArray = (jthread *) jvmtiMalloc(sizeof(jthread) * length); 549 NULL_CHECK(objArray, nullptr); 550 551 for (int i = 0; i < length; i++) { 552 objArray[i] = (jthread)jni_reference(handles[i]); 553 } 554 return objArray; 555 } 556 557 jthreadGroup * 558 JvmtiEnvBase::new_jthreadGroupArray(int length, objArrayHandle groups) { 559 if (length == 0) { 560 return nullptr; 561 } 562 563 jthreadGroup* objArray = (jthreadGroup *) jvmtiMalloc(sizeof(jthreadGroup) * length); 564 NULL_CHECK(objArray, nullptr); 565 566 for (int i = 0; i < length; i++) { 567 objArray[i] = (jthreadGroup)JNIHandles::make_local(groups->obj_at(i)); 568 } 569 return objArray; 570 } 571 572 // Return the vframe on the specified thread and depth, null if no such frame. 573 // The thread and the oops in the returned vframe might not have been processed. 574 javaVFrame* 575 JvmtiEnvBase::jvf_for_thread_and_depth(JavaThread* java_thread, jint depth) { 576 if (!java_thread->has_last_Java_frame()) { 577 return nullptr; 578 } 579 RegisterMap reg_map(java_thread, 580 RegisterMap::UpdateMap::include, 581 RegisterMap::ProcessFrames::skip, 582 RegisterMap::WalkContinuation::include); 583 javaVFrame *jvf = java_thread->last_java_vframe(®_map); 584 585 jvf = JvmtiEnvBase::check_and_skip_hidden_frames(java_thread, jvf); 586 587 for (int d = 0; jvf != nullptr && d < depth; d++) { 588 jvf = jvf->java_sender(); 589 } 590 return jvf; 591 } 592 593 // 594 // utilities: JNI objects 595 // 596 597 598 jclass 599 JvmtiEnvBase::get_jni_class_non_null(Klass* k) { 600 assert(k != nullptr, "k != null"); 601 Thread *thread = Thread::current(); 602 return (jclass)jni_reference(Handle(thread, k->java_mirror())); 603 } 604 605 // 606 // Field Information 607 // 608 609 bool 610 JvmtiEnvBase::get_field_descriptor(Klass* k, jfieldID field, fieldDescriptor* fd) { 611 if (!jfieldIDWorkaround::is_valid_jfieldID(k, field)) { 612 return false; 613 } 614 bool found = false; 615 if (jfieldIDWorkaround::is_static_jfieldID(field)) { 616 JNIid* id = jfieldIDWorkaround::from_static_jfieldID(field); 617 found = id->find_local_field(fd); 618 } else { 619 // Non-static field. The fieldID is really the offset of the field within the object. 620 int offset = jfieldIDWorkaround::from_instance_jfieldID(k, field); 621 found = InstanceKlass::cast(k)->find_field_from_offset(offset, false, fd); 622 } 623 return found; 624 } 625 626 bool 627 JvmtiEnvBase::is_vthread_alive(oop vt) { 628 oop cont = java_lang_VirtualThread::continuation(vt); 629 return !jdk_internal_vm_Continuation::done(cont) && 630 java_lang_VirtualThread::state(vt) != java_lang_VirtualThread::NEW; 631 } 632 633 // Return JavaThread if virtual thread is mounted, null otherwise. 634 JavaThread* JvmtiEnvBase::get_JavaThread_or_null(oop vthread) { 635 oop carrier_thread = java_lang_VirtualThread::carrier_thread(vthread); 636 if (carrier_thread == nullptr) { 637 return nullptr; 638 } 639 640 JavaThread* java_thread = java_lang_Thread::thread(carrier_thread); 641 642 // This could be a different thread to the current one. So we need to ensure that 643 // processing has started before we are allowed to read the continuation oop of 644 // another thread, as it is a direct root of that other thread. 645 StackWatermarkSet::start_processing(java_thread, StackWatermarkKind::gc); 646 647 oop cont = java_lang_VirtualThread::continuation(vthread); 648 assert(cont != nullptr, "must be"); 649 assert(Continuation::continuation_scope(cont) == java_lang_VirtualThread::vthread_scope(), "must be"); 650 return Continuation::is_continuation_mounted(java_thread, cont) ? java_thread : nullptr; 651 } 652 653 javaVFrame* 654 JvmtiEnvBase::check_and_skip_hidden_frames(bool is_in_VTMS_transition, javaVFrame* jvf) { 655 // The second condition is needed to hide notification methods. 656 if (!is_in_VTMS_transition && (jvf == nullptr || !jvf->method()->jvmti_mount_transition())) { 657 return jvf; // No frames to skip. 658 } 659 // Find jvf with a method annotated with @JvmtiMountTransition. 660 for ( ; jvf != nullptr; jvf = jvf->java_sender()) { 661 if (jvf->method()->jvmti_mount_transition()) { // Cannot actually appear in an unmounted continuation; they're never frozen. 662 jvf = jvf->java_sender(); // Skip annotated method. 663 break; 664 } 665 if (jvf->method()->changes_current_thread()) { 666 break; 667 } 668 // Skip frame above annotated method. 669 } 670 return jvf; 671 } 672 673 javaVFrame* 674 JvmtiEnvBase::check_and_skip_hidden_frames(JavaThread* jt, javaVFrame* jvf) { 675 jvf = check_and_skip_hidden_frames(jt->is_in_VTMS_transition(), jvf); 676 return jvf; 677 } 678 679 javaVFrame* 680 JvmtiEnvBase::check_and_skip_hidden_frames(oop vthread, javaVFrame* jvf) { 681 JvmtiThreadState* state = java_lang_Thread::jvmti_thread_state(vthread); 682 if (state == nullptr) { 683 // nothing to skip 684 return jvf; 685 } 686 jvf = check_and_skip_hidden_frames(java_lang_Thread::is_in_VTMS_transition(vthread), jvf); 687 return jvf; 688 } 689 690 javaVFrame* 691 JvmtiEnvBase::get_vthread_jvf(oop vthread) { 692 assert(java_lang_VirtualThread::state(vthread) != java_lang_VirtualThread::NEW, "sanity check"); 693 assert(java_lang_VirtualThread::state(vthread) != java_lang_VirtualThread::TERMINATED, "sanity check"); 694 695 Thread* cur_thread = Thread::current(); 696 oop cont = java_lang_VirtualThread::continuation(vthread); 697 javaVFrame* jvf = nullptr; 698 699 JavaThread* java_thread = get_JavaThread_or_null(vthread); 700 if (java_thread != nullptr) { 701 if (!java_thread->has_last_Java_frame()) { 702 // TBD: This is a temporary work around to avoid a guarantee caused by 703 // the native enterSpecial frame on the top. No frames will be found 704 // by the JVMTI functions such as GetStackTrace. 705 return nullptr; 706 } 707 vframeStream vfs(java_thread); 708 jvf = vfs.at_end() ? nullptr : vfs.asJavaVFrame(); 709 jvf = check_and_skip_hidden_frames(java_thread, jvf); 710 } else { 711 vframeStream vfs(cont); 712 jvf = vfs.at_end() ? nullptr : vfs.asJavaVFrame(); 713 jvf = check_and_skip_hidden_frames(vthread, jvf); 714 } 715 return jvf; 716 } 717 718 // Return correct javaVFrame for a carrier (non-virtual) thread. 719 // It strips vthread frames at the top if there are any. 720 javaVFrame* 721 JvmtiEnvBase::get_cthread_last_java_vframe(JavaThread* jt, RegisterMap* reg_map_p) { 722 // Strip vthread frames in case of carrier thread with mounted continuation. 723 bool cthread_with_cont = JvmtiEnvBase::is_cthread_with_continuation(jt); 724 javaVFrame *jvf = cthread_with_cont ? jt->carrier_last_java_vframe(reg_map_p) 725 : jt->last_java_vframe(reg_map_p); 726 // Skip hidden frames only for carrier threads 727 // which are in non-temporary VTMS transition. 728 if (jt->is_in_VTMS_transition()) { 729 jvf = check_and_skip_hidden_frames(jt, jvf); 730 } 731 return jvf; 732 } 733 734 jint 735 JvmtiEnvBase::get_thread_state_base(oop thread_oop, JavaThread* jt) { 736 jint state = 0; 737 738 if (thread_oop != nullptr) { 739 // Get most state bits. 740 state = (jint)java_lang_Thread::get_thread_status(thread_oop); 741 } 742 if (jt != nullptr) { 743 // We have a JavaThread* so add more state bits. 744 JavaThreadState jts = jt->thread_state(); 745 746 if (jt->is_carrier_thread_suspended() || 747 ((jt->jvmti_vthread() == nullptr || jt->jvmti_vthread() == thread_oop) && jt->is_suspended())) { 748 // Suspended non-virtual thread. 749 state |= JVMTI_THREAD_STATE_SUSPENDED; 750 } 751 if (jts == _thread_in_native) { 752 state |= JVMTI_THREAD_STATE_IN_NATIVE; 753 } 754 if (jt->is_interrupted(false)) { 755 state |= JVMTI_THREAD_STATE_INTERRUPTED; 756 } 757 } 758 return state; 759 } 760 761 jint 762 JvmtiEnvBase::get_thread_state(oop thread_oop, JavaThread* jt) { 763 jint state = 0; 764 765 if (is_thread_carrying_vthread(jt, thread_oop)) { 766 state = (jint)java_lang_Thread::get_thread_status(thread_oop); 767 768 // This is for extra safety. Other bits are not expected nor needed. 769 state &= (JVMTI_THREAD_STATE_ALIVE | JVMTI_THREAD_STATE_INTERRUPTED); 770 771 if (jt->is_carrier_thread_suspended()) { 772 state |= JVMTI_THREAD_STATE_SUSPENDED; 773 } 774 // It's okay for the JVMTI state to be reported as WAITING when waiting 775 // for something other than an Object.wait. So, we treat a thread carrying 776 // a virtual thread as waiting indefinitely which is not runnable. 777 // It is why the RUNNABLE bit is not needed and the WAITING bits are added. 778 state |= JVMTI_THREAD_STATE_WAITING | JVMTI_THREAD_STATE_WAITING_INDEFINITELY; 779 } else { 780 state = get_thread_state_base(thread_oop, jt); 781 } 782 return state; 783 } 784 785 jint 786 JvmtiEnvBase::get_vthread_state(oop thread_oop, JavaThread* java_thread) { 787 jint state = 0; 788 bool ext_suspended = JvmtiVTSuspender::is_vthread_suspended(thread_oop); 789 jint interrupted = java_lang_Thread::interrupted(thread_oop); 790 791 if (java_thread != nullptr) { 792 // If virtual thread is blocked on a monitor enter the BLOCKED_ON_MONITOR_ENTER bit 793 // is set for carrier thread instead of virtual. 794 // Other state bits except filtered ones are expected to be the same. 795 oop ct_oop = java_lang_VirtualThread::carrier_thread(thread_oop); 796 jint filtered_bits = JVMTI_THREAD_STATE_SUSPENDED | JVMTI_THREAD_STATE_INTERRUPTED; 797 798 // This call can trigger a safepoint, so thread_oop must not be used after it. 799 state = get_thread_state_base(ct_oop, java_thread) & ~filtered_bits; 800 } else { 801 int vt_state = java_lang_VirtualThread::state(thread_oop); 802 state = (jint)java_lang_VirtualThread::map_state_to_thread_status(vt_state); 803 } 804 // Ensure the thread has not exited after retrieving suspended/interrupted values. 805 if ((state & JVMTI_THREAD_STATE_ALIVE) != 0) { 806 if (ext_suspended) { 807 state |= JVMTI_THREAD_STATE_SUSPENDED; 808 } 809 if (interrupted) { 810 state |= JVMTI_THREAD_STATE_INTERRUPTED; 811 } 812 } 813 return state; 814 } 815 816 jint 817 JvmtiEnvBase::get_thread_or_vthread_state(oop thread_oop, JavaThread* java_thread) { 818 jint state = 0; 819 if (java_lang_VirtualThread::is_instance(thread_oop)) { 820 state = JvmtiEnvBase::get_vthread_state(thread_oop, java_thread); 821 } else { 822 state = JvmtiEnvBase::get_thread_state(thread_oop, java_thread); 823 } 824 return state; 825 } 826 827 jvmtiError 828 JvmtiEnvBase::get_live_threads(JavaThread* current_thread, Handle group_hdl, jint *count_ptr, Handle **thread_objs_p) { 829 jint count = 0; 830 Handle *thread_objs = nullptr; 831 ThreadsListEnumerator tle(current_thread, /* include_jvmti_agent_threads */ true); 832 int nthreads = tle.num_threads(); 833 if (nthreads > 0) { 834 thread_objs = NEW_RESOURCE_ARRAY_RETURN_NULL(Handle, nthreads); 835 NULL_CHECK(thread_objs, JVMTI_ERROR_OUT_OF_MEMORY); 836 for (int i = 0; i < nthreads; i++) { 837 Handle thread = tle.get_threadObj(i); 838 if (thread()->is_a(vmClasses::Thread_klass()) && java_lang_Thread::threadGroup(thread()) == group_hdl()) { 839 thread_objs[count++] = thread; 840 } 841 } 842 } 843 *thread_objs_p = thread_objs; 844 *count_ptr = count; 845 return JVMTI_ERROR_NONE; 846 } 847 848 jvmtiError 849 JvmtiEnvBase::get_subgroups(JavaThread* current_thread, Handle group_hdl, jint *count_ptr, objArrayHandle *group_objs_p) { 850 851 // This call collects the strong and weak groups 852 JavaThread* THREAD = current_thread; 853 JavaValue result(T_OBJECT); 854 JavaCalls::call_virtual(&result, 855 group_hdl, 856 vmClasses::ThreadGroup_klass(), 857 SymbolTable::new_permanent_symbol("subgroupsAsArray"), 858 vmSymbols::void_threadgroup_array_signature(), 859 THREAD); 860 if (HAS_PENDING_EXCEPTION) { 861 Symbol* ex_name = PENDING_EXCEPTION->klass()->name(); 862 CLEAR_PENDING_EXCEPTION; 863 if (ex_name == vmSymbols::java_lang_OutOfMemoryError()) { 864 return JVMTI_ERROR_OUT_OF_MEMORY; 865 } else { 866 return JVMTI_ERROR_INTERNAL; 867 } 868 } 869 870 assert(result.get_type() == T_OBJECT, "just checking"); 871 objArrayOop groups = (objArrayOop)result.get_oop(); 872 873 *count_ptr = groups == nullptr ? 0 : groups->length(); 874 *group_objs_p = objArrayHandle(current_thread, groups); 875 876 return JVMTI_ERROR_NONE; 877 } 878 879 // 880 // Object Monitor Information 881 // 882 883 // 884 // Count the number of objects for a lightweight monitor. The hobj 885 // parameter is object that owns the monitor so this routine will 886 // count the number of times the same object was locked by frames 887 // in java_thread. 888 // 889 jint 890 JvmtiEnvBase::count_locked_objects(JavaThread *java_thread, Handle hobj) { 891 jint ret = 0; 892 if (!java_thread->has_last_Java_frame()) { 893 return ret; // no Java frames so no monitors 894 } 895 896 Thread* current_thread = Thread::current(); 897 ResourceMark rm(current_thread); 898 HandleMark hm(current_thread); 899 RegisterMap reg_map(java_thread, 900 RegisterMap::UpdateMap::include, 901 RegisterMap::ProcessFrames::include, 902 RegisterMap::WalkContinuation::skip); 903 904 for (javaVFrame *jvf = java_thread->last_java_vframe(®_map); jvf != nullptr; 905 jvf = jvf->java_sender()) { 906 GrowableArray<MonitorInfo*>* mons = jvf->monitors(); 907 if (!mons->is_empty()) { 908 for (int i = 0; i < mons->length(); i++) { 909 MonitorInfo *mi = mons->at(i); 910 if (mi->owner_is_scalar_replaced()) continue; 911 912 // see if owner of the monitor is our object 913 if (mi->owner() != nullptr && mi->owner() == hobj()) { 914 ret++; 915 } 916 } 917 } 918 } 919 return ret; 920 } 921 922 jvmtiError 923 JvmtiEnvBase::get_current_contended_monitor(JavaThread *calling_thread, JavaThread *java_thread, 924 jobject *monitor_ptr, bool is_virtual) { 925 Thread *current_thread = Thread::current(); 926 assert(java_thread->is_handshake_safe_for(current_thread), 927 "call by myself or at handshake"); 928 if (!is_virtual && JvmtiEnvBase::is_cthread_with_continuation(java_thread)) { 929 // Carrier thread with a mounted continuation case. 930 // No contended monitor can be owned by carrier thread in this case. 931 *monitor_ptr = nullptr; 932 return JVMTI_ERROR_NONE; 933 } 934 oop obj = nullptr; 935 // The ObjectMonitor* can't be async deflated since we are either 936 // at a safepoint or the calling thread is operating on itself so 937 // it cannot leave the underlying wait()/enter() call. 938 ObjectMonitor *mon = java_thread->current_waiting_monitor(); 939 if (mon == nullptr) { 940 // thread is not doing an Object.wait() call 941 mon = java_thread->current_pending_monitor(); 942 if (mon != nullptr) { 943 // The thread is trying to enter() an ObjectMonitor. 944 obj = mon->object(); 945 assert(obj != nullptr, "ObjectMonitor should have a valid object!"); 946 } 947 } else { 948 // thread is doing an Object.wait() call 949 oop thread_oop = get_vthread_or_thread_oop(java_thread); 950 jint state = get_thread_or_vthread_state(thread_oop, java_thread); 951 952 if (state & JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER) { 953 // thread is re-entering the monitor in an Object.wait() call 954 obj = mon->object(); 955 assert(obj != nullptr, "Object.wait() should have an object"); 956 } 957 } 958 959 if (obj == nullptr) { 960 *monitor_ptr = nullptr; 961 } else { 962 HandleMark hm(current_thread); 963 Handle hobj(current_thread, obj); 964 *monitor_ptr = jni_reference(calling_thread, hobj); 965 } 966 return JVMTI_ERROR_NONE; 967 } 968 969 jvmtiError 970 JvmtiEnvBase::get_owned_monitors(JavaThread *calling_thread, JavaThread* java_thread, 971 GrowableArray<jvmtiMonitorStackDepthInfo*> *owned_monitors_list) { 972 // Note: 973 // calling_thread is the thread that requested the list of monitors for java_thread. 974 // java_thread is the thread owning the monitors. 975 // current_thread is the thread executing this code, can be a non-JavaThread (e.g. VM Thread). 976 // And they all may be different threads. 977 jvmtiError err = JVMTI_ERROR_NONE; 978 Thread *current_thread = Thread::current(); 979 assert(java_thread->is_handshake_safe_for(current_thread), 980 "call by myself or at handshake"); 981 982 if (JvmtiEnvBase::is_cthread_with_continuation(java_thread)) { 983 // Carrier thread with a mounted continuation case. 984 // No contended monitor can be owned by carrier thread in this case. 985 return JVMTI_ERROR_NONE; 986 } 987 if (java_thread->has_last_Java_frame()) { 988 ResourceMark rm(current_thread); 989 HandleMark hm(current_thread); 990 RegisterMap reg_map(java_thread, 991 RegisterMap::UpdateMap::include, 992 RegisterMap::ProcessFrames::include, 993 RegisterMap::WalkContinuation::skip); 994 995 int depth = 0; 996 for (javaVFrame *jvf = get_cthread_last_java_vframe(java_thread, ®_map); 997 jvf != nullptr; jvf = jvf->java_sender()) { 998 if (MaxJavaStackTraceDepth == 0 || depth++ < MaxJavaStackTraceDepth) { // check for stack too deep 999 // add locked objects for this frame into list 1000 err = get_locked_objects_in_frame(calling_thread, java_thread, jvf, owned_monitors_list, depth-1); 1001 if (err != JVMTI_ERROR_NONE) { 1002 return err; 1003 } 1004 } 1005 } 1006 } 1007 1008 // Get off stack monitors. (e.g. acquired via jni MonitorEnter). 1009 JvmtiMonitorClosure jmc(calling_thread, owned_monitors_list, this); 1010 ObjectSynchronizer::owned_monitors_iterate(&jmc, java_thread); 1011 err = jmc.error(); 1012 1013 return err; 1014 } 1015 1016 jvmtiError 1017 JvmtiEnvBase::get_owned_monitors(JavaThread* calling_thread, JavaThread* java_thread, javaVFrame* jvf, 1018 GrowableArray<jvmtiMonitorStackDepthInfo*> *owned_monitors_list) { 1019 jvmtiError err = JVMTI_ERROR_NONE; 1020 Thread *current_thread = Thread::current(); 1021 assert(java_thread->is_handshake_safe_for(current_thread), 1022 "call by myself or at handshake"); 1023 1024 int depth = 0; 1025 for ( ; jvf != nullptr; jvf = jvf->java_sender()) { 1026 if (MaxJavaStackTraceDepth == 0 || depth++ < MaxJavaStackTraceDepth) { // check for stack too deep 1027 // Add locked objects for this frame into list. 1028 err = get_locked_objects_in_frame(calling_thread, java_thread, jvf, owned_monitors_list, depth - 1); 1029 if (err != JVMTI_ERROR_NONE) { 1030 return err; 1031 } 1032 } 1033 } 1034 1035 // Get off stack monitors. (e.g. acquired via jni MonitorEnter). 1036 JvmtiMonitorClosure jmc(calling_thread, owned_monitors_list, this); 1037 ObjectSynchronizer::owned_monitors_iterate(&jmc, java_thread); 1038 err = jmc.error(); 1039 1040 return err; 1041 } 1042 1043 // Save JNI local handles for any objects that this frame owns. 1044 jvmtiError 1045 JvmtiEnvBase::get_locked_objects_in_frame(JavaThread* calling_thread, JavaThread* java_thread, 1046 javaVFrame *jvf, GrowableArray<jvmtiMonitorStackDepthInfo*>* owned_monitors_list, jint stack_depth) { 1047 jvmtiError err = JVMTI_ERROR_NONE; 1048 Thread* current_thread = Thread::current(); 1049 ResourceMark rm(current_thread); 1050 HandleMark hm(current_thread); 1051 1052 GrowableArray<MonitorInfo*>* mons = jvf->monitors(); 1053 if (mons->is_empty()) { 1054 return err; // this javaVFrame holds no monitors 1055 } 1056 1057 oop wait_obj = nullptr; 1058 { 1059 // The ObjectMonitor* can't be async deflated since we are either 1060 // at a safepoint or the calling thread is operating on itself so 1061 // it cannot leave the underlying wait() call. 1062 // Save object of current wait() call (if any) for later comparison. 1063 ObjectMonitor *mon = java_thread->current_waiting_monitor(); 1064 if (mon != nullptr) { 1065 wait_obj = mon->object(); 1066 } 1067 } 1068 oop pending_obj = nullptr; 1069 { 1070 // The ObjectMonitor* can't be async deflated since we are either 1071 // at a safepoint or the calling thread is operating on itself so 1072 // it cannot leave the underlying enter() call. 1073 // Save object of current enter() call (if any) for later comparison. 1074 ObjectMonitor *mon = java_thread->current_pending_monitor(); 1075 if (mon != nullptr) { 1076 pending_obj = mon->object(); 1077 } 1078 } 1079 1080 for (int i = 0; i < mons->length(); i++) { 1081 MonitorInfo *mi = mons->at(i); 1082 1083 if (mi->owner_is_scalar_replaced()) continue; 1084 1085 oop obj = mi->owner(); 1086 if (obj == nullptr) { 1087 // this monitor doesn't have an owning object so skip it 1088 continue; 1089 } 1090 1091 if (wait_obj == obj) { 1092 // the thread is waiting on this monitor so it isn't really owned 1093 continue; 1094 } 1095 1096 if (pending_obj == obj) { 1097 // the thread is pending on this monitor so it isn't really owned 1098 continue; 1099 } 1100 1101 if (owned_monitors_list->length() > 0) { 1102 // Our list has at least one object on it so we have to check 1103 // for recursive object locking 1104 bool found = false; 1105 for (int j = 0; j < owned_monitors_list->length(); j++) { 1106 jobject jobj = ((jvmtiMonitorStackDepthInfo*)owned_monitors_list->at(j))->monitor; 1107 oop check = JNIHandles::resolve(jobj); 1108 if (check == obj) { 1109 found = true; // we found the object 1110 break; 1111 } 1112 } 1113 1114 if (found) { 1115 // already have this object so don't include it 1116 continue; 1117 } 1118 } 1119 1120 // add the owning object to our list 1121 jvmtiMonitorStackDepthInfo *jmsdi; 1122 err = allocate(sizeof(jvmtiMonitorStackDepthInfo), (unsigned char **)&jmsdi); 1123 if (err != JVMTI_ERROR_NONE) { 1124 return err; 1125 } 1126 Handle hobj(Thread::current(), obj); 1127 jmsdi->monitor = jni_reference(calling_thread, hobj); 1128 jmsdi->stack_depth = stack_depth; 1129 owned_monitors_list->append(jmsdi); 1130 } 1131 1132 return err; 1133 } 1134 1135 jvmtiError 1136 JvmtiEnvBase::get_stack_trace(javaVFrame *jvf, 1137 jint start_depth, jint max_count, 1138 jvmtiFrameInfo* frame_buffer, jint* count_ptr) { 1139 Thread *current_thread = Thread::current(); 1140 ResourceMark rm(current_thread); 1141 HandleMark hm(current_thread); 1142 int count = 0; 1143 1144 if (start_depth != 0) { 1145 if (start_depth > 0) { 1146 for (int j = 0; j < start_depth && jvf != nullptr; j++) { 1147 jvf = jvf->java_sender(); 1148 } 1149 if (jvf == nullptr) { 1150 // start_depth is deeper than the stack depth. 1151 return JVMTI_ERROR_ILLEGAL_ARGUMENT; 1152 } 1153 } else { // start_depth < 0 1154 // We are referencing the starting depth based on the oldest 1155 // part of the stack. 1156 // Optimize to limit the number of times that java_sender() is called. 1157 javaVFrame *jvf_cursor = jvf; 1158 javaVFrame *jvf_prev = nullptr; 1159 javaVFrame *jvf_prev_prev = nullptr; 1160 int j = 0; 1161 while (jvf_cursor != nullptr) { 1162 jvf_prev_prev = jvf_prev; 1163 jvf_prev = jvf_cursor; 1164 for (j = 0; j > start_depth && jvf_cursor != nullptr; j--) { 1165 jvf_cursor = jvf_cursor->java_sender(); 1166 } 1167 } 1168 if (j == start_depth) { 1169 // Previous pointer is exactly where we want to start. 1170 jvf = jvf_prev; 1171 } else { 1172 // We need to back up further to get to the right place. 1173 if (jvf_prev_prev == nullptr) { 1174 // The -start_depth is greater than the stack depth. 1175 return JVMTI_ERROR_ILLEGAL_ARGUMENT; 1176 } 1177 // j is now the number of frames on the stack starting with 1178 // jvf_prev, we start from jvf_prev_prev and move older on 1179 // the stack that many, and the result is -start_depth frames 1180 // remaining. 1181 jvf = jvf_prev_prev; 1182 for (; j < 0; j++) { 1183 jvf = jvf->java_sender(); 1184 } 1185 } 1186 } 1187 } 1188 for (; count < max_count && jvf != nullptr; count++) { 1189 frame_buffer[count].method = jvf->method()->jmethod_id(); 1190 frame_buffer[count].location = (jvf->method()->is_native() ? -1 : jvf->bci()); 1191 jvf = jvf->java_sender(); 1192 } 1193 *count_ptr = count; 1194 return JVMTI_ERROR_NONE; 1195 } 1196 1197 jvmtiError 1198 JvmtiEnvBase::get_stack_trace(JavaThread *java_thread, 1199 jint start_depth, jint max_count, 1200 jvmtiFrameInfo* frame_buffer, jint* count_ptr) { 1201 Thread *current_thread = Thread::current(); 1202 assert(SafepointSynchronize::is_at_safepoint() || 1203 java_thread->is_handshake_safe_for(current_thread), 1204 "call by myself / at safepoint / at handshake"); 1205 int count = 0; 1206 jvmtiError err = JVMTI_ERROR_NONE; 1207 1208 if (java_thread->has_last_Java_frame()) { 1209 RegisterMap reg_map(java_thread, 1210 RegisterMap::UpdateMap::include, 1211 RegisterMap::ProcessFrames::skip, 1212 RegisterMap::WalkContinuation::skip); 1213 ResourceMark rm(current_thread); 1214 javaVFrame *jvf = get_cthread_last_java_vframe(java_thread, ®_map); 1215 1216 err = get_stack_trace(jvf, start_depth, max_count, frame_buffer, count_ptr); 1217 } else { 1218 *count_ptr = 0; 1219 if (start_depth != 0) { 1220 // no frames and there is a starting depth 1221 err = JVMTI_ERROR_ILLEGAL_ARGUMENT; 1222 } 1223 } 1224 return err; 1225 } 1226 1227 jint 1228 JvmtiEnvBase::get_frame_count(javaVFrame *jvf) { 1229 int count = 0; 1230 1231 while (jvf != nullptr) { 1232 jvf = jvf->java_sender(); 1233 count++; 1234 } 1235 return count; 1236 } 1237 1238 jvmtiError 1239 JvmtiEnvBase::get_frame_count(JavaThread* jt, jint *count_ptr) { 1240 Thread *current_thread = Thread::current(); 1241 assert(current_thread == jt || 1242 SafepointSynchronize::is_at_safepoint() || 1243 jt->is_handshake_safe_for(current_thread), 1244 "call by myself / at safepoint / at handshake"); 1245 1246 if (!jt->has_last_Java_frame()) { // no Java frames 1247 *count_ptr = 0; 1248 } else { 1249 ResourceMark rm(current_thread); 1250 RegisterMap reg_map(jt, 1251 RegisterMap::UpdateMap::include, 1252 RegisterMap::ProcessFrames::include, 1253 RegisterMap::WalkContinuation::skip); 1254 javaVFrame *jvf = get_cthread_last_java_vframe(jt, ®_map); 1255 1256 *count_ptr = get_frame_count(jvf); 1257 } 1258 return JVMTI_ERROR_NONE; 1259 } 1260 1261 jvmtiError 1262 JvmtiEnvBase::get_frame_count(oop vthread_oop, jint *count_ptr) { 1263 Thread *current_thread = Thread::current(); 1264 ResourceMark rm(current_thread); 1265 javaVFrame *jvf = JvmtiEnvBase::get_vthread_jvf(vthread_oop); 1266 1267 *count_ptr = get_frame_count(jvf); 1268 return JVMTI_ERROR_NONE; 1269 } 1270 1271 jvmtiError 1272 JvmtiEnvBase::get_frame_location(javaVFrame* jvf, jint depth, 1273 jmethodID* method_ptr, jlocation* location_ptr) { 1274 int cur_depth = 0; 1275 1276 while (jvf != nullptr && cur_depth < depth) { 1277 jvf = jvf->java_sender(); 1278 cur_depth++; 1279 } 1280 assert(depth >= cur_depth, "ran out of frames too soon"); 1281 if (jvf == nullptr) { 1282 return JVMTI_ERROR_NO_MORE_FRAMES; 1283 } 1284 Method* method = jvf->method(); 1285 if (method->is_native()) { 1286 *location_ptr = -1; 1287 } else { 1288 *location_ptr = jvf->bci(); 1289 } 1290 *method_ptr = method->jmethod_id(); 1291 return JVMTI_ERROR_NONE; 1292 } 1293 1294 jvmtiError 1295 JvmtiEnvBase::get_frame_location(JavaThread *java_thread, jint depth, 1296 jmethodID* method_ptr, jlocation* location_ptr) { 1297 Thread* current = Thread::current(); 1298 assert(java_thread->is_handshake_safe_for(current), 1299 "call by myself or at handshake"); 1300 if (!java_thread->has_last_Java_frame()) { 1301 return JVMTI_ERROR_NO_MORE_FRAMES; 1302 } 1303 ResourceMark rm(current); 1304 HandleMark hm(current); 1305 RegisterMap reg_map(java_thread, 1306 RegisterMap::UpdateMap::include, 1307 RegisterMap::ProcessFrames::skip, 1308 RegisterMap::WalkContinuation::include); 1309 javaVFrame* jvf = JvmtiEnvBase::get_cthread_last_java_vframe(java_thread, ®_map); 1310 1311 return get_frame_location(jvf, depth, method_ptr, location_ptr); 1312 } 1313 1314 jvmtiError 1315 JvmtiEnvBase::get_frame_location(oop vthread_oop, jint depth, 1316 jmethodID* method_ptr, jlocation* location_ptr) { 1317 Thread* current = Thread::current(); 1318 ResourceMark rm(current); 1319 HandleMark hm(current); 1320 javaVFrame *jvf = JvmtiEnvBase::get_vthread_jvf(vthread_oop); 1321 1322 return get_frame_location(jvf, depth, method_ptr, location_ptr); 1323 } 1324 1325 jvmtiError 1326 JvmtiEnvBase::set_frame_pop(JvmtiThreadState* state, javaVFrame* jvf, jint depth) { 1327 for (int d = 0; jvf != nullptr && d < depth; d++) { 1328 jvf = jvf->java_sender(); 1329 } 1330 if (jvf == nullptr) { 1331 return JVMTI_ERROR_NO_MORE_FRAMES; 1332 } 1333 if (jvf->method()->is_native()) { 1334 return JVMTI_ERROR_OPAQUE_FRAME; 1335 } 1336 assert(jvf->frame_pointer() != nullptr, "frame pointer mustn't be null"); 1337 int frame_number = (int)get_frame_count(jvf); 1338 state->env_thread_state((JvmtiEnvBase*)this)->set_frame_pop(frame_number); 1339 return JVMTI_ERROR_NONE; 1340 } 1341 1342 bool 1343 JvmtiEnvBase::is_cthread_with_mounted_vthread(JavaThread* jt) { 1344 oop thread_oop = jt->threadObj(); 1345 assert(thread_oop != nullptr, "sanity check"); 1346 oop mounted_vt = jt->jvmti_vthread(); 1347 1348 return mounted_vt != nullptr && mounted_vt != thread_oop; 1349 } 1350 1351 bool 1352 JvmtiEnvBase::is_cthread_with_continuation(JavaThread* jt) { 1353 const ContinuationEntry* cont_entry = nullptr; 1354 if (jt->has_last_Java_frame()) { 1355 cont_entry = jt->vthread_continuation(); 1356 } 1357 return cont_entry != nullptr && is_cthread_with_mounted_vthread(jt); 1358 } 1359 1360 // Check if VirtualThread or BoundVirtualThread is suspended. 1361 bool 1362 JvmtiEnvBase::is_vthread_suspended(oop vt_oop, JavaThread* jt) { 1363 bool suspended = false; 1364 if (java_lang_VirtualThread::is_instance(vt_oop)) { 1365 suspended = JvmtiVTSuspender::is_vthread_suspended(vt_oop); 1366 } 1367 if (vt_oop->is_a(vmClasses::BoundVirtualThread_klass())) { 1368 suspended = jt->is_suspended(); 1369 } 1370 return suspended; 1371 } 1372 1373 // If (thread == null) then return current thread object. 1374 // Otherwise return JNIHandles::resolve_external_guard(thread). 1375 oop 1376 JvmtiEnvBase::current_thread_obj_or_resolve_external_guard(jthread thread) { 1377 oop thread_obj = JNIHandles::resolve_external_guard(thread); 1378 if (thread == nullptr) { 1379 thread_obj = get_vthread_or_thread_oop(JavaThread::current()); 1380 } 1381 return thread_obj; 1382 } 1383 1384 jvmtiError 1385 JvmtiEnvBase::get_threadOop_and_JavaThread(ThreadsList* t_list, jthread thread, JavaThread* cur_thread, 1386 JavaThread** jt_pp, oop* thread_oop_p) { 1387 JavaThread* java_thread = nullptr; 1388 oop thread_oop = nullptr; 1389 1390 if (thread == nullptr) { 1391 if (cur_thread == nullptr) { // cur_thread can be null when called from a VM_op 1392 return JVMTI_ERROR_INVALID_THREAD; 1393 } 1394 java_thread = cur_thread; 1395 thread_oop = get_vthread_or_thread_oop(java_thread); 1396 if (thread_oop == nullptr || !thread_oop->is_a(vmClasses::Thread_klass())) { 1397 return JVMTI_ERROR_INVALID_THREAD; 1398 } 1399 } else { 1400 jvmtiError err = JvmtiExport::cv_external_thread_to_JavaThread(t_list, thread, &java_thread, &thread_oop); 1401 if (err != JVMTI_ERROR_NONE) { 1402 // We got an error code so we don't have a JavaThread*, but only return 1403 // an error from here if we didn't get a valid thread_oop. In a vthread case 1404 // the cv_external_thread_to_JavaThread is expected to correctly set the 1405 // thread_oop and return JVMTI_ERROR_INVALID_THREAD which we ignore here. 1406 if (thread_oop == nullptr || err != JVMTI_ERROR_INVALID_THREAD) { 1407 *thread_oop_p = thread_oop; 1408 return err; 1409 } 1410 } 1411 if (java_thread == nullptr && java_lang_VirtualThread::is_instance(thread_oop)) { 1412 java_thread = get_JavaThread_or_null(thread_oop); 1413 } 1414 } 1415 *jt_pp = java_thread; 1416 *thread_oop_p = thread_oop; 1417 if (java_lang_VirtualThread::is_instance(thread_oop) && 1418 !JvmtiEnvBase::is_vthread_alive(thread_oop)) { 1419 return JVMTI_ERROR_THREAD_NOT_ALIVE; 1420 } 1421 return JVMTI_ERROR_NONE; 1422 } 1423 1424 jvmtiError 1425 JvmtiEnvBase::get_threadOop_and_JavaThread(ThreadsList* t_list, jthread thread, 1426 JavaThread** jt_pp, oop* thread_oop_p) { 1427 JavaThread* cur_thread = JavaThread::current(); 1428 jvmtiError err = get_threadOop_and_JavaThread(t_list, thread, cur_thread, jt_pp, thread_oop_p); 1429 return err; 1430 } 1431 1432 // Check for JVMTI_ERROR_NOT_SUSPENDED and JVMTI_ERROR_OPAQUE_FRAME errors. 1433 // Used in PopFrame and ForceEarlyReturn implementations. 1434 jvmtiError 1435 JvmtiEnvBase::check_non_suspended_or_opaque_frame(JavaThread* jt, oop thr_obj, bool self) { 1436 bool is_virtual = thr_obj != nullptr && thr_obj->is_a(vmClasses::BaseVirtualThread_klass()); 1437 1438 if (is_virtual) { 1439 if (!is_JavaThread_current(jt, thr_obj)) { 1440 if (!is_vthread_suspended(thr_obj, jt)) { 1441 return JVMTI_ERROR_THREAD_NOT_SUSPENDED; 1442 } 1443 if (jt == nullptr) { // unmounted virtual thread 1444 return JVMTI_ERROR_OPAQUE_FRAME; 1445 } 1446 } 1447 } else { // platform thread 1448 if (!self && !jt->is_suspended() && 1449 !jt->is_carrier_thread_suspended()) { 1450 return JVMTI_ERROR_THREAD_NOT_SUSPENDED; 1451 } 1452 } 1453 return JVMTI_ERROR_NONE; 1454 } 1455 1456 jvmtiError 1457 JvmtiEnvBase::get_object_monitor_usage(JavaThread* calling_thread, jobject object, jvmtiMonitorUsage* info_ptr) { 1458 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint"); 1459 Thread* current_thread = VMThread::vm_thread(); 1460 assert(current_thread == Thread::current(), "must be"); 1461 1462 HandleMark hm(current_thread); 1463 Handle hobj; 1464 1465 // Check arguments 1466 { 1467 oop mirror = JNIHandles::resolve_external_guard(object); 1468 NULL_CHECK(mirror, JVMTI_ERROR_INVALID_OBJECT); 1469 NULL_CHECK(info_ptr, JVMTI_ERROR_NULL_POINTER); 1470 1471 hobj = Handle(current_thread, mirror); 1472 } 1473 1474 ThreadsListHandle tlh(current_thread); 1475 JavaThread *owning_thread = nullptr; 1476 ObjectMonitor *mon = nullptr; 1477 jvmtiMonitorUsage ret = { 1478 nullptr, 0, 0, nullptr, 0, nullptr 1479 }; 1480 1481 uint32_t debug_bits = 0; 1482 // first derive the object's owner and entry_count (if any) 1483 owning_thread = ObjectSynchronizer::get_lock_owner(tlh.list(), hobj); 1484 if (owning_thread != nullptr) { 1485 Handle th(current_thread, get_vthread_or_thread_oop(owning_thread)); 1486 ret.owner = (jthread)jni_reference(calling_thread, th); 1487 1488 // The recursions field of a monitor does not reflect recursions 1489 // as lightweight locks before inflating the monitor are not included. 1490 // We have to count the number of recursive monitor entries the hard way. 1491 // We pass a handle to survive any GCs along the way. 1492 ret.entry_count = count_locked_objects(owning_thread, hobj); 1493 } 1494 // implied else: entry_count == 0 1495 1496 jint nWant = 0, nWait = 0; 1497 markWord mark = hobj->mark(); 1498 ResourceMark rm(current_thread); 1499 GrowableArray<JavaThread*>* wantList = nullptr; 1500 1501 if (mark.has_monitor()) { 1502 mon = mark.monitor(); 1503 assert(mon != nullptr, "must have monitor"); 1504 // this object has a heavyweight monitor 1505 nWant = mon->contentions(); // # of threads contending for monitor entry, but not re-entry 1506 nWait = mon->waiters(); // # of threads waiting for notification, 1507 // or to re-enter monitor, in Object.wait() 1508 1509 // Get the actual set of threads trying to enter, or re-enter, the monitor. 1510 wantList = Threads::get_pending_threads(tlh.list(), nWant + nWait, (address)mon); 1511 nWant = wantList->length(); 1512 } else { 1513 // this object has a lightweight monitor 1514 } 1515 1516 if (mon != nullptr) { 1517 // Robustness: the actual waiting list can be smaller. 1518 // The nWait count we got from the mon->waiters() may include the re-entering 1519 // the monitor threads after being notified. Here we are correcting the actual 1520 // number of the waiting threads by excluding those re-entering the monitor. 1521 nWait = 0; 1522 for (ObjectWaiter* waiter = mon->first_waiter(); 1523 waiter != nullptr && (nWait == 0 || waiter != mon->first_waiter()); 1524 waiter = mon->next_waiter(waiter)) { 1525 nWait++; 1526 } 1527 } 1528 ret.waiter_count = nWant; 1529 ret.notify_waiter_count = nWait; 1530 1531 // Allocate memory for heavyweight and lightweight monitor. 1532 jvmtiError err; 1533 err = allocate(ret.waiter_count * sizeof(jthread *), (unsigned char**)&ret.waiters); 1534 if (err != JVMTI_ERROR_NONE) { 1535 return err; 1536 } 1537 err = allocate(ret.notify_waiter_count * sizeof(jthread *), 1538 (unsigned char**)&ret.notify_waiters); 1539 if (err != JVMTI_ERROR_NONE) { 1540 deallocate((unsigned char*)ret.waiters); 1541 return err; 1542 } 1543 1544 // now derive the rest of the fields 1545 if (mon != nullptr) { 1546 // this object has a heavyweight monitor 1547 1548 // null out memory for robustness 1549 memset(ret.waiters, 0, ret.waiter_count * sizeof(jthread *)); 1550 memset(ret.notify_waiters, 0, ret.notify_waiter_count * sizeof(jthread *)); 1551 1552 if (ret.waiter_count > 0) { // we have contending threads waiting to enter/re-enter the monitor 1553 // identify threads waiting to enter and re-enter the monitor 1554 // get_pending_threads returns only java thread so we do not need to 1555 // check for non java threads. 1556 for (int i = 0; i < nWant; i++) { 1557 JavaThread *pending_thread = wantList->at(i); 1558 Handle th(current_thread, get_vthread_or_thread_oop(pending_thread)); 1559 ret.waiters[i] = (jthread)jni_reference(calling_thread, th); 1560 } 1561 } 1562 if (ret.notify_waiter_count > 0) { // we have threads waiting to be notified in Object.wait() 1563 ObjectWaiter *waiter = mon->first_waiter(); 1564 for (int i = 0; i < nWait; i++) { 1565 JavaThread *w = mon->thread_of_waiter(waiter); 1566 assert(w != nullptr, "sanity check"); 1567 // If the thread was found on the ObjectWaiter list, then 1568 // it has not been notified. 1569 Handle th(current_thread, get_vthread_or_thread_oop(w)); 1570 ret.notify_waiters[i] = (jthread)jni_reference(calling_thread, th); 1571 waiter = mon->next_waiter(waiter); 1572 } 1573 } 1574 } else { 1575 // this object has a lightweight monitor and we have nothing more 1576 // to do here because the defaults are just fine. 1577 } 1578 1579 // we don't update return parameter unless everything worked 1580 *info_ptr = ret; 1581 1582 return JVMTI_ERROR_NONE; 1583 } 1584 1585 jvmtiError 1586 JvmtiEnvBase::check_thread_list(jint count, const jthread* list) { 1587 if (list == nullptr && count != 0) { 1588 return JVMTI_ERROR_NULL_POINTER; 1589 } 1590 for (int i = 0; i < count; i++) { 1591 jthread thread = list[i]; 1592 oop thread_oop = JNIHandles::resolve_external_guard(thread); 1593 if (thread_oop == nullptr || !thread_oop->is_a(vmClasses::BaseVirtualThread_klass())) { 1594 return JVMTI_ERROR_INVALID_THREAD; 1595 } 1596 } 1597 return JVMTI_ERROR_NONE; 1598 } 1599 1600 bool 1601 JvmtiEnvBase::is_in_thread_list(jint count, const jthread* list, oop jt_oop) { 1602 for (int idx = 0; idx < count; idx++) { 1603 jthread thread = list[idx]; 1604 oop thread_oop = JNIHandles::resolve_external_guard(thread); 1605 if (thread_oop == jt_oop) { 1606 return true; 1607 } 1608 } 1609 return false; 1610 } 1611 1612 class VM_SetNotifyJvmtiEventsMode : public VM_Operation { 1613 private: 1614 bool _enable; 1615 1616 static void correct_jvmti_thread_state(JavaThread* jt) { 1617 oop ct_oop = jt->threadObj(); 1618 oop vt_oop = jt->vthread(); 1619 JvmtiThreadState* jt_state = jt->jvmti_thread_state(); 1620 JvmtiThreadState* ct_state = java_lang_Thread::jvmti_thread_state(jt->threadObj()); 1621 JvmtiThreadState* vt_state = vt_oop != nullptr ? java_lang_Thread::jvmti_thread_state(vt_oop) : nullptr; 1622 bool virt = vt_oop != nullptr && java_lang_VirtualThread::is_instance(vt_oop); 1623 1624 // Correct jt->jvmti_thread_state() and jt->jvmti_vthread(). 1625 // It was not maintained while notifyJvmti was disabled. 1626 if (virt) { 1627 jt->set_jvmti_thread_state(nullptr); // reset jt->jvmti_thread_state() 1628 jt->set_jvmti_vthread(vt_oop); // restore jt->jvmti_vthread() 1629 } else { 1630 jt->set_jvmti_thread_state(ct_state); // restore jt->jvmti_thread_state() 1631 jt->set_jvmti_vthread(ct_oop); // restore jt->jvmti_vthread() 1632 } 1633 } 1634 1635 // This function is called only if _enable == true. 1636 // Iterates over all JavaThread's, counts VTMS transitions and restores 1637 // jt->jvmti_thread_state() and jt->jvmti_vthread() for VTMS transition protocol. 1638 int count_transitions_and_correct_jvmti_thread_states() { 1639 int count = 0; 1640 1641 for (JavaThread* jt : ThreadsListHandle()) { 1642 if (jt->is_in_VTMS_transition()) { 1643 count++; 1644 continue; // no need in JvmtiThreadState correction below if in transition 1645 } 1646 correct_jvmti_thread_state(jt); 1647 } 1648 return count; 1649 } 1650 1651 public: 1652 VMOp_Type type() const { return VMOp_SetNotifyJvmtiEventsMode; } 1653 bool allow_nested_vm_operations() const { return false; } 1654 VM_SetNotifyJvmtiEventsMode(bool enable) : _enable(enable) { 1655 } 1656 1657 void doit() { 1658 int count = _enable ? count_transitions_and_correct_jvmti_thread_states() : 0; 1659 1660 JvmtiVTMSTransitionDisabler::set_VTMS_transition_count(count); 1661 JvmtiVTMSTransitionDisabler::set_VTMS_notify_jvmti_events(_enable); 1662 } 1663 }; 1664 1665 // This function is to support agents loaded into running VM. 1666 // Must be called in thread-in-native mode. 1667 bool 1668 JvmtiEnvBase::enable_virtual_threads_notify_jvmti() { 1669 if (!Continuations::enabled()) { 1670 return false; 1671 } 1672 if (JvmtiVTMSTransitionDisabler::VTMS_notify_jvmti_events()) { 1673 return false; // already enabled 1674 } 1675 VM_SetNotifyJvmtiEventsMode op(true); 1676 VMThread::execute(&op); 1677 return true; 1678 } 1679 1680 // This function is used in WhiteBox, only needed to test the function above. 1681 // It is unsafe to use this function when virtual threads are executed. 1682 // Must be called in thread-in-native mode. 1683 bool 1684 JvmtiEnvBase::disable_virtual_threads_notify_jvmti() { 1685 if (!Continuations::enabled()) { 1686 return false; 1687 } 1688 if (!JvmtiVTMSTransitionDisabler::VTMS_notify_jvmti_events()) { 1689 return false; // already disabled 1690 } 1691 JvmtiVTMSTransitionDisabler disabler(true); // ensure there are no other disablers 1692 VM_SetNotifyJvmtiEventsMode op(false); 1693 VMThread::execute(&op); 1694 return true; 1695 } 1696 1697 // java_thread - protected by ThreadsListHandle 1698 jvmtiError 1699 JvmtiEnvBase::suspend_thread(oop thread_oop, JavaThread* java_thread, bool single_suspend, 1700 int* need_safepoint_p) { 1701 JavaThread* current = JavaThread::current(); 1702 HandleMark hm(current); 1703 Handle thread_h(current, thread_oop); 1704 bool is_virtual = java_lang_VirtualThread::is_instance(thread_h()); 1705 1706 if (is_virtual) { 1707 if (single_suspend) { 1708 if (JvmtiVTSuspender::is_vthread_suspended(thread_h())) { 1709 return JVMTI_ERROR_THREAD_SUSPENDED; 1710 } 1711 JvmtiVTSuspender::register_vthread_suspend(thread_h()); 1712 // Check if virtual thread is mounted and there is a java_thread. 1713 // A non-null java_thread is always passed in the !single_suspend case. 1714 oop carrier_thread = java_lang_VirtualThread::carrier_thread(thread_h()); 1715 java_thread = carrier_thread == nullptr ? nullptr : java_lang_Thread::thread(carrier_thread); 1716 } 1717 // The java_thread can be still blocked in VTMS transition after a previous JVMTI resume call. 1718 // There is no need to suspend the java_thread in this case. After vthread unblocking, 1719 // it will check for ext_suspend request and suspend itself if necessary. 1720 if (java_thread == nullptr || java_thread->is_suspended()) { 1721 // We are done if the virtual thread is unmounted or 1722 // the java_thread is externally suspended. 1723 return JVMTI_ERROR_NONE; 1724 } 1725 // The virtual thread is mounted: suspend the java_thread. 1726 } 1727 // Don't allow hidden thread suspend request. 1728 if (java_thread->is_hidden_from_external_view()) { 1729 return JVMTI_ERROR_NONE; 1730 } 1731 bool is_thread_carrying = is_thread_carrying_vthread(java_thread, thread_h()); 1732 1733 // A case of non-virtual thread. 1734 if (!is_virtual) { 1735 // Thread.suspend() is used in some tests. It sets jt->is_suspended() only. 1736 if (java_thread->is_carrier_thread_suspended() || 1737 (!is_thread_carrying && java_thread->is_suspended())) { 1738 return JVMTI_ERROR_THREAD_SUSPENDED; 1739 } 1740 java_thread->set_carrier_thread_suspended(); 1741 } 1742 assert(!java_thread->is_in_VTMS_transition(), "sanity check"); 1743 1744 assert(!single_suspend || (!is_virtual && java_thread->is_carrier_thread_suspended()) || 1745 (is_virtual && JvmtiVTSuspender::is_vthread_suspended(thread_h())), 1746 "sanity check"); 1747 1748 // An attempt to handshake-suspend a thread carrying a virtual thread will result in 1749 // suspension of mounted virtual thread. So, we just mark it as suspended 1750 // and it will be actually suspended at virtual thread unmount transition. 1751 if (!is_thread_carrying) { 1752 assert(thread_h() != nullptr, "sanity check"); 1753 assert(single_suspend || thread_h()->is_a(vmClasses::BaseVirtualThread_klass()), 1754 "SuspendAllVirtualThreads should never suspend non-virtual threads"); 1755 // Case of mounted virtual or attached carrier thread. 1756 if (!JvmtiSuspendControl::suspend(java_thread)) { 1757 // Thread is already suspended or in process of exiting. 1758 if (java_thread->is_exiting()) { 1759 // The thread was in the process of exiting. 1760 return JVMTI_ERROR_THREAD_NOT_ALIVE; 1761 } 1762 return JVMTI_ERROR_THREAD_SUSPENDED; 1763 } 1764 } 1765 return JVMTI_ERROR_NONE; 1766 } 1767 1768 // java_thread - protected by ThreadsListHandle 1769 jvmtiError 1770 JvmtiEnvBase::resume_thread(oop thread_oop, JavaThread* java_thread, bool single_resume) { 1771 JavaThread* current = JavaThread::current(); 1772 HandleMark hm(current); 1773 Handle thread_h(current, thread_oop); 1774 bool is_virtual = java_lang_VirtualThread::is_instance(thread_h()); 1775 1776 if (is_virtual) { 1777 if (single_resume) { 1778 if (!JvmtiVTSuspender::is_vthread_suspended(thread_h())) { 1779 return JVMTI_ERROR_THREAD_NOT_SUSPENDED; 1780 } 1781 JvmtiVTSuspender::register_vthread_resume(thread_h()); 1782 // Check if virtual thread is mounted and there is a java_thread. 1783 // A non-null java_thread is always passed in the !single_resume case. 1784 oop carrier_thread = java_lang_VirtualThread::carrier_thread(thread_h()); 1785 java_thread = carrier_thread == nullptr ? nullptr : java_lang_Thread::thread(carrier_thread); 1786 } 1787 // The java_thread can be still blocked in VTMS transition after a previous JVMTI suspend call. 1788 // There is no need to resume the java_thread in this case. After vthread unblocking, 1789 // it will check for is_vthread_suspended request and remain resumed if necessary. 1790 if (java_thread == nullptr || !java_thread->is_suspended()) { 1791 // We are done if the virtual thread is unmounted or 1792 // the java_thread is not externally suspended. 1793 return JVMTI_ERROR_NONE; 1794 } 1795 // The virtual thread is mounted and java_thread is supended: resume the java_thread. 1796 } 1797 // Don't allow hidden thread resume request. 1798 if (java_thread->is_hidden_from_external_view()) { 1799 return JVMTI_ERROR_NONE; 1800 } 1801 bool is_thread_carrying = is_thread_carrying_vthread(java_thread, thread_h()); 1802 1803 // A case of a non-virtual thread. 1804 if (!is_virtual) { 1805 if (!java_thread->is_carrier_thread_suspended() && 1806 (is_thread_carrying || !java_thread->is_suspended())) { 1807 return JVMTI_ERROR_THREAD_NOT_SUSPENDED; 1808 } 1809 java_thread->clear_carrier_thread_suspended(); 1810 } 1811 assert(!java_thread->is_in_VTMS_transition(), "sanity check"); 1812 1813 if (!is_thread_carrying) { 1814 assert(thread_h() != nullptr, "sanity check"); 1815 assert(single_resume || thread_h()->is_a(vmClasses::BaseVirtualThread_klass()), 1816 "ResumeAllVirtualThreads should never resume non-virtual threads"); 1817 if (java_thread->is_suspended()) { 1818 if (!JvmtiSuspendControl::resume(java_thread)) { 1819 return JVMTI_ERROR_THREAD_NOT_SUSPENDED; 1820 } 1821 } 1822 } 1823 return JVMTI_ERROR_NONE; 1824 } 1825 1826 ResourceTracker::ResourceTracker(JvmtiEnv* env) { 1827 _env = env; 1828 _allocations = new (mtServiceability) GrowableArray<unsigned char*>(20, mtServiceability); 1829 _failed = false; 1830 } 1831 ResourceTracker::~ResourceTracker() { 1832 if (_failed) { 1833 for (int i=0; i<_allocations->length(); i++) { 1834 _env->deallocate(_allocations->at(i)); 1835 } 1836 } 1837 delete _allocations; 1838 } 1839 1840 jvmtiError ResourceTracker::allocate(jlong size, unsigned char** mem_ptr) { 1841 unsigned char *ptr; 1842 jvmtiError err = _env->allocate(size, &ptr); 1843 if (err == JVMTI_ERROR_NONE) { 1844 _allocations->append(ptr); 1845 *mem_ptr = ptr; 1846 } else { 1847 *mem_ptr = nullptr; 1848 _failed = true; 1849 } 1850 return err; 1851 } 1852 1853 unsigned char* ResourceTracker::allocate(jlong size) { 1854 unsigned char* ptr; 1855 allocate(size, &ptr); 1856 return ptr; 1857 } 1858 1859 char* ResourceTracker::strdup(const char* str) { 1860 char *dup_str = (char*)allocate(strlen(str)+1); 1861 if (dup_str != nullptr) { 1862 strcpy(dup_str, str); 1863 } 1864 return dup_str; 1865 } 1866 1867 struct StackInfoNode { 1868 struct StackInfoNode *next; 1869 jvmtiStackInfo info; 1870 }; 1871 1872 // Create a jvmtiStackInfo inside a linked list node and create a 1873 // buffer for the frame information, both allocated as resource objects. 1874 // Fill in both the jvmtiStackInfo and the jvmtiFrameInfo. 1875 // Note that either or both of thr and thread_oop 1876 // may be null if the thread is new or has exited. 1877 void 1878 MultipleStackTracesCollector::fill_frames(jthread jt, JavaThread *thr, oop thread_oop) { 1879 #ifdef ASSERT 1880 Thread *current_thread = Thread::current(); 1881 assert(SafepointSynchronize::is_at_safepoint() || 1882 thr == nullptr || 1883 thr->is_handshake_safe_for(current_thread), 1884 "unmounted virtual thread / call by myself / at safepoint / at handshake"); 1885 #endif 1886 1887 jint state = 0; 1888 struct StackInfoNode *node = NEW_RESOURCE_OBJ(struct StackInfoNode); 1889 jvmtiStackInfo *infop = &(node->info); 1890 1891 node->next = head(); 1892 set_head(node); 1893 infop->frame_count = 0; 1894 infop->frame_buffer = nullptr; 1895 infop->thread = jt; 1896 1897 if (java_lang_VirtualThread::is_instance(thread_oop)) { 1898 state = JvmtiEnvBase::get_vthread_state(thread_oop, thr); 1899 1900 if ((state & JVMTI_THREAD_STATE_ALIVE) != 0) { 1901 javaVFrame *jvf = JvmtiEnvBase::get_vthread_jvf(thread_oop); 1902 infop->frame_buffer = NEW_RESOURCE_ARRAY(jvmtiFrameInfo, max_frame_count()); 1903 _result = env()->get_stack_trace(jvf, 0, max_frame_count(), 1904 infop->frame_buffer, &(infop->frame_count)); 1905 } 1906 } else { 1907 state = JvmtiEnvBase::get_thread_state(thread_oop, thr); 1908 if (thr != nullptr && (state & JVMTI_THREAD_STATE_ALIVE) != 0) { 1909 infop->frame_buffer = NEW_RESOURCE_ARRAY(jvmtiFrameInfo, max_frame_count()); 1910 _result = env()->get_stack_trace(thr, 0, max_frame_count(), 1911 infop->frame_buffer, &(infop->frame_count)); 1912 } 1913 } 1914 _frame_count_total += infop->frame_count; 1915 infop->state = state; 1916 } 1917 1918 // Based on the stack information in the linked list, allocate memory 1919 // block to return and fill it from the info in the linked list. 1920 void 1921 MultipleStackTracesCollector::allocate_and_fill_stacks(jint thread_count) { 1922 // do I need to worry about alignment issues? 1923 jlong alloc_size = thread_count * sizeof(jvmtiStackInfo) 1924 + _frame_count_total * sizeof(jvmtiFrameInfo); 1925 env()->allocate(alloc_size, (unsigned char **)&_stack_info); 1926 1927 // pointers to move through the newly allocated space as it is filled in 1928 jvmtiStackInfo *si = _stack_info + thread_count; // bottom of stack info 1929 jvmtiFrameInfo *fi = (jvmtiFrameInfo *)si; // is the top of frame info 1930 1931 // copy information in resource area into allocated buffer 1932 // insert stack info backwards since linked list is backwards 1933 // insert frame info forwards 1934 // walk the StackInfoNodes 1935 for (struct StackInfoNode *sin = head(); sin != nullptr; sin = sin->next) { 1936 jint frame_count = sin->info.frame_count; 1937 size_t frames_size = frame_count * sizeof(jvmtiFrameInfo); 1938 --si; 1939 memcpy(si, &(sin->info), sizeof(jvmtiStackInfo)); 1940 if (frames_size == 0) { 1941 si->frame_buffer = nullptr; 1942 } else { 1943 memcpy(fi, sin->info.frame_buffer, frames_size); 1944 si->frame_buffer = fi; // point to the new allocated copy of the frames 1945 fi += frame_count; 1946 } 1947 } 1948 assert(si == _stack_info, "the last copied stack info must be the first record"); 1949 assert((unsigned char *)fi == ((unsigned char *)_stack_info) + alloc_size, 1950 "the last copied frame info must be the last record"); 1951 } 1952 1953 // AdapterClosure is to make use of JvmtiUnitedHandshakeClosure objects from 1954 // Handshake::execute() which is unaware of the do_vthread() member functions. 1955 class AdapterClosure : public HandshakeClosure { 1956 JvmtiUnitedHandshakeClosure* _hs_cl; 1957 Handle _target_h; 1958 1959 public: 1960 AdapterClosure(JvmtiUnitedHandshakeClosure* hs_cl, Handle target_h) 1961 : HandshakeClosure(hs_cl->name()), _hs_cl(hs_cl), _target_h(target_h) {} 1962 1963 virtual void do_thread(Thread* target) { 1964 if (java_lang_VirtualThread::is_instance(_target_h())) { 1965 _hs_cl->do_vthread(_target_h); // virtual thread 1966 } else { 1967 _hs_cl->do_thread(target); // platform thread 1968 } 1969 } 1970 }; 1971 1972 // Supports platform and virtual threads. 1973 // JvmtiVTMSTransitionDisabler is always set by this function. 1974 void 1975 JvmtiHandshake::execute(JvmtiUnitedHandshakeClosure* hs_cl, jthread target) { 1976 JavaThread* current = JavaThread::current(); 1977 HandleMark hm(current); 1978 1979 JvmtiVTMSTransitionDisabler disabler(target); 1980 ThreadsListHandle tlh(current); 1981 JavaThread* java_thread = nullptr; 1982 oop thread_obj = nullptr; 1983 1984 jvmtiError err = JvmtiEnvBase::get_threadOop_and_JavaThread(tlh.list(), target, &java_thread, &thread_obj); 1985 if (err != JVMTI_ERROR_NONE) { 1986 hs_cl->set_result(err); 1987 return; 1988 } 1989 Handle target_h(current, thread_obj); 1990 execute(hs_cl, &tlh, java_thread, target_h); 1991 } 1992 1993 // Supports platform and virtual threads. 1994 // A virtual thread is always identified by the target_h oop handle. 1995 // The target_jt is always nullptr for an unmounted virtual thread. 1996 // JvmtiVTMSTransitionDisabler has to be set before call to this function. 1997 void 1998 JvmtiHandshake::execute(JvmtiUnitedHandshakeClosure* hs_cl, ThreadsListHandle* tlh, 1999 JavaThread* target_jt, Handle target_h) { 2000 bool self = target_jt == JavaThread::current(); 2001 2002 hs_cl->set_self(self); // needed when suspend is required for non-current target thread 2003 2004 if (java_lang_VirtualThread::is_instance(target_h())) { // virtual thread 2005 if (!JvmtiEnvBase::is_vthread_alive(target_h())) { 2006 return; 2007 } 2008 if (target_jt == nullptr) { // unmounted virtual thread 2009 hs_cl->do_vthread(target_h); // execute handshake closure callback on current thread directly 2010 } 2011 } 2012 if (target_jt != nullptr) { // mounted virtual or platform thread 2013 AdapterClosure acl(hs_cl, target_h); 2014 if (self) { // target platform thread is current 2015 acl.do_thread(target_jt); // execute handshake closure callback on current thread directly 2016 } else { 2017 Handshake::execute(&acl, tlh, target_jt); // delegate to Handshake implementation 2018 } 2019 } 2020 } 2021 2022 void 2023 VM_GetThreadListStackTraces::doit() { 2024 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint"); 2025 2026 ResourceMark rm; 2027 ThreadsListHandle tlh; 2028 for (int i = 0; i < _thread_count; ++i) { 2029 jthread jt = _thread_list[i]; 2030 JavaThread* java_thread = nullptr; 2031 oop thread_oop = nullptr; 2032 jvmtiError err = JvmtiEnvBase::get_threadOop_and_JavaThread(tlh.list(), jt, nullptr, &java_thread, &thread_oop); 2033 2034 if (err != JVMTI_ERROR_NONE) { 2035 // We got an error code so we don't have a JavaThread *, but 2036 // only return an error from here if we didn't get a valid 2037 // thread_oop. 2038 // In the virtual thread case the get_threadOop_and_JavaThread is expected to correctly set 2039 // the thread_oop and return JVMTI_ERROR_THREAD_NOT_ALIVE which we ignore here. 2040 // The corresponding thread state will be recorded in the jvmtiStackInfo.state. 2041 if (thread_oop == nullptr) { 2042 _collector.set_result(err); 2043 return; 2044 } 2045 // We have a valid thread_oop. 2046 } 2047 _collector.fill_frames(jt, java_thread, thread_oop); 2048 } 2049 _collector.allocate_and_fill_stacks(_thread_count); 2050 } 2051 2052 void 2053 GetSingleStackTraceClosure::do_thread(Thread *target) { 2054 JavaThread *jt = JavaThread::cast(target); 2055 oop thread_oop = JNIHandles::resolve_external_guard(_jthread); 2056 2057 if (!jt->is_exiting() && thread_oop != nullptr) { 2058 ResourceMark rm; 2059 _collector.fill_frames(_jthread, jt, thread_oop); 2060 _collector.allocate_and_fill_stacks(1); 2061 } 2062 } 2063 2064 void 2065 VM_GetAllStackTraces::doit() { 2066 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint"); 2067 2068 ResourceMark rm; 2069 _final_thread_count = 0; 2070 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *jt = jtiwh.next(); ) { 2071 oop thread_oop = jt->threadObj(); 2072 if (thread_oop != nullptr && 2073 !jt->is_exiting() && 2074 java_lang_Thread::is_alive(thread_oop) && 2075 !jt->is_hidden_from_external_view() && 2076 !thread_oop->is_a(vmClasses::BoundVirtualThread_klass())) { 2077 ++_final_thread_count; 2078 // Handle block of the calling thread is used to create local refs. 2079 _collector.fill_frames((jthread)JNIHandles::make_local(_calling_thread, thread_oop), 2080 jt, thread_oop); 2081 } 2082 } 2083 _collector.allocate_and_fill_stacks(_final_thread_count); 2084 } 2085 2086 // Verifies that the top frame is a java frame in an expected state. 2087 // Deoptimizes frame if needed. 2088 // Checks that the frame method signature matches the return type (tos). 2089 // HandleMark must be defined in the caller only. 2090 // It is to keep a ret_ob_h handle alive after return to the caller. 2091 jvmtiError 2092 JvmtiEnvBase::check_top_frame(Thread* current_thread, JavaThread* java_thread, 2093 jvalue value, TosState tos, Handle* ret_ob_h) { 2094 ResourceMark rm(current_thread); 2095 2096 javaVFrame* jvf = jvf_for_thread_and_depth(java_thread, 0); 2097 NULL_CHECK(jvf, JVMTI_ERROR_NO_MORE_FRAMES); 2098 2099 if (jvf->method()->is_native()) { 2100 return JVMTI_ERROR_OPAQUE_FRAME; 2101 } 2102 2103 // If the frame is a compiled one, need to deoptimize it. 2104 if (jvf->is_compiled_frame()) { 2105 if (!jvf->fr().can_be_deoptimized()) { 2106 return JVMTI_ERROR_OPAQUE_FRAME; 2107 } 2108 Deoptimization::deoptimize_frame(java_thread, jvf->fr().id()); 2109 } 2110 2111 // Get information about method return type 2112 Symbol* signature = jvf->method()->signature(); 2113 2114 ResultTypeFinder rtf(signature); 2115 TosState fr_tos = as_TosState(rtf.type()); 2116 if (fr_tos != tos) { 2117 if (tos != itos || (fr_tos != btos && fr_tos != ztos && fr_tos != ctos && fr_tos != stos)) { 2118 return JVMTI_ERROR_TYPE_MISMATCH; 2119 } 2120 } 2121 2122 // Check that the jobject class matches the return type signature. 2123 jobject jobj = value.l; 2124 if (tos == atos && jobj != nullptr) { // null reference is allowed 2125 Handle ob_h(current_thread, JNIHandles::resolve_external_guard(jobj)); 2126 NULL_CHECK(ob_h, JVMTI_ERROR_INVALID_OBJECT); 2127 Klass* ob_k = ob_h()->klass(); 2128 NULL_CHECK(ob_k, JVMTI_ERROR_INVALID_OBJECT); 2129 2130 // Method return type signature. 2131 char* ty_sign = 1 + strchr(signature->as_C_string(), JVM_SIGNATURE_ENDFUNC); 2132 2133 if (!VM_GetOrSetLocal::is_assignable(ty_sign, ob_k, current_thread)) { 2134 return JVMTI_ERROR_TYPE_MISMATCH; 2135 } 2136 *ret_ob_h = ob_h; 2137 } 2138 return JVMTI_ERROR_NONE; 2139 } /* end check_top_frame */ 2140 2141 2142 // ForceEarlyReturn<type> follows the PopFrame approach in many aspects. 2143 // Main difference is on the last stage in the interpreter. 2144 // The PopFrame stops method execution to continue execution 2145 // from the same method call instruction. 2146 // The ForceEarlyReturn forces return from method so the execution 2147 // continues at the bytecode following the method call. 2148 2149 // thread - NOT protected by ThreadsListHandle and NOT pre-checked 2150 2151 jvmtiError 2152 JvmtiEnvBase::force_early_return(jthread thread, jvalue value, TosState tos) { 2153 JavaThread* current_thread = JavaThread::current(); 2154 HandleMark hm(current_thread); 2155 2156 JvmtiVTMSTransitionDisabler disabler(thread); 2157 ThreadsListHandle tlh(current_thread); 2158 2159 JavaThread* java_thread = nullptr; 2160 oop thread_obj = nullptr; 2161 jvmtiError err = get_threadOop_and_JavaThread(tlh.list(), thread, &java_thread, &thread_obj); 2162 2163 if (err != JVMTI_ERROR_NONE) { 2164 return err; 2165 } 2166 bool self = java_thread == current_thread; 2167 2168 err = check_non_suspended_or_opaque_frame(java_thread, thread_obj, self); 2169 if (err != JVMTI_ERROR_NONE) { 2170 return err; 2171 } 2172 2173 // retrieve or create the state 2174 JvmtiThreadState* state = JvmtiThreadState::state_for(java_thread); 2175 if (state == nullptr) { 2176 return JVMTI_ERROR_THREAD_NOT_ALIVE; 2177 } 2178 2179 // Eagerly reallocate scalar replaced objects. 2180 EscapeBarrier eb(true, current_thread, java_thread); 2181 if (!eb.deoptimize_objects(0)) { 2182 // Reallocation of scalar replaced objects failed -> return with error 2183 return JVMTI_ERROR_OUT_OF_MEMORY; 2184 } 2185 2186 SetForceEarlyReturn op(state, value, tos); 2187 if (self) { 2188 op.doit(java_thread, self); 2189 } else { 2190 Handshake::execute(&op, java_thread); 2191 } 2192 return op.result(); 2193 } 2194 2195 void 2196 SetForceEarlyReturn::doit(Thread *target, bool self) { 2197 JavaThread* java_thread = JavaThread::cast(target); 2198 Thread* current_thread = Thread::current(); 2199 HandleMark hm(current_thread); 2200 2201 if (java_thread->is_exiting()) { 2202 return; /* JVMTI_ERROR_THREAD_NOT_ALIVE (default) */ 2203 } 2204 2205 // Check to see if a ForceEarlyReturn was already in progress 2206 if (_state->is_earlyret_pending()) { 2207 // Probably possible for JVMTI clients to trigger this, but the 2208 // JPDA backend shouldn't allow this to happen 2209 _result = JVMTI_ERROR_INTERNAL; 2210 return; 2211 } 2212 { 2213 // The same as for PopFrame. Workaround bug: 2214 // 4812902: popFrame hangs if the method is waiting at a synchronize 2215 // Catch this condition and return an error to avoid hanging. 2216 // Now JVMTI spec allows an implementation to bail out with an opaque 2217 // frame error. 2218 OSThread* osThread = java_thread->osthread(); 2219 if (osThread->get_state() == MONITOR_WAIT) { 2220 _result = JVMTI_ERROR_OPAQUE_FRAME; 2221 return; 2222 } 2223 } 2224 2225 Handle ret_ob_h; 2226 _result = JvmtiEnvBase::check_top_frame(current_thread, java_thread, _value, _tos, &ret_ob_h); 2227 if (_result != JVMTI_ERROR_NONE) { 2228 return; 2229 } 2230 assert(_tos != atos || _value.l == nullptr || ret_ob_h() != nullptr, 2231 "return object oop must not be null if jobject is not null"); 2232 2233 // Update the thread state to reflect that the top frame must be 2234 // forced to return. 2235 // The current frame will be returned later when the suspended 2236 // thread is resumed and right before returning from VM to Java. 2237 // (see call_VM_base() in assembler_<cpu>.cpp). 2238 2239 _state->set_earlyret_pending(); 2240 _state->set_earlyret_oop(ret_ob_h()); 2241 _state->set_earlyret_value(_value, _tos); 2242 2243 // Set pending step flag for this early return. 2244 // It is cleared when next step event is posted. 2245 _state->set_pending_step_for_earlyret(); 2246 } 2247 2248 void 2249 JvmtiMonitorClosure::do_monitor(ObjectMonitor* mon) { 2250 if ( _error != JVMTI_ERROR_NONE) { 2251 // Error occurred in previous iteration so no need to add 2252 // to the list. 2253 return; 2254 } 2255 // Filter out on stack monitors collected during stack walk. 2256 oop obj = mon->object(); 2257 2258 if (obj == nullptr) { 2259 // This can happen if JNI code drops all references to the 2260 // owning object. 2261 return; 2262 } 2263 2264 bool found = false; 2265 for (int j = 0; j < _owned_monitors_list->length(); j++) { 2266 jobject jobj = ((jvmtiMonitorStackDepthInfo*)_owned_monitors_list->at(j))->monitor; 2267 oop check = JNIHandles::resolve(jobj); 2268 if (check == obj) { 2269 // On stack monitor already collected during the stack walk. 2270 found = true; 2271 break; 2272 } 2273 } 2274 if (found == false) { 2275 // This is off stack monitor (e.g. acquired via jni MonitorEnter). 2276 jvmtiError err; 2277 jvmtiMonitorStackDepthInfo *jmsdi; 2278 err = _env->allocate(sizeof(jvmtiMonitorStackDepthInfo), (unsigned char **)&jmsdi); 2279 if (err != JVMTI_ERROR_NONE) { 2280 _error = err; 2281 return; 2282 } 2283 Handle hobj(Thread::current(), obj); 2284 jmsdi->monitor = _env->jni_reference(_calling_thread, hobj); 2285 // stack depth is unknown for this monitor. 2286 jmsdi->stack_depth = -1; 2287 _owned_monitors_list->append(jmsdi); 2288 } 2289 } 2290 2291 GrowableArray<OopHandle>* JvmtiModuleClosure::_tbl = nullptr; 2292 2293 void JvmtiModuleClosure::do_module(ModuleEntry* entry) { 2294 assert_locked_or_safepoint(Module_lock); 2295 OopHandle module = entry->module_handle(); 2296 guarantee(module.resolve() != nullptr, "module object is null"); 2297 _tbl->push(module); 2298 } 2299 2300 jvmtiError 2301 JvmtiModuleClosure::get_all_modules(JvmtiEnv* env, jint* module_count_ptr, jobject** modules_ptr) { 2302 ResourceMark rm; 2303 MutexLocker mcld(ClassLoaderDataGraph_lock); 2304 MutexLocker ml(Module_lock); 2305 2306 _tbl = new GrowableArray<OopHandle>(77); 2307 if (_tbl == nullptr) { 2308 return JVMTI_ERROR_OUT_OF_MEMORY; 2309 } 2310 2311 // Iterate over all the modules loaded to the system. 2312 ClassLoaderDataGraph::modules_do(&do_module); 2313 2314 jint len = _tbl->length(); 2315 guarantee(len > 0, "at least one module must be present"); 2316 2317 jobject* array = (jobject*)env->jvmtiMalloc((jlong)(len * sizeof(jobject))); 2318 if (array == nullptr) { 2319 return JVMTI_ERROR_OUT_OF_MEMORY; 2320 } 2321 for (jint idx = 0; idx < len; idx++) { 2322 array[idx] = JNIHandles::make_local(_tbl->at(idx).resolve()); 2323 } 2324 _tbl = nullptr; 2325 *modules_ptr = array; 2326 *module_count_ptr = len; 2327 return JVMTI_ERROR_NONE; 2328 } 2329 2330 void 2331 UpdateForPopTopFrameClosure::doit(Thread *target, bool self) { 2332 Thread* current_thread = Thread::current(); 2333 HandleMark hm(current_thread); 2334 JavaThread* java_thread = JavaThread::cast(target); 2335 2336 if (java_thread->is_exiting()) { 2337 return; /* JVMTI_ERROR_THREAD_NOT_ALIVE (default) */ 2338 } 2339 assert(java_thread == _state->get_thread(), "Must be"); 2340 2341 // Check to see if a PopFrame was already in progress 2342 if (java_thread->popframe_condition() != JavaThread::popframe_inactive) { 2343 // Probably possible for JVMTI clients to trigger this, but the 2344 // JPDA backend shouldn't allow this to happen 2345 _result = JVMTI_ERROR_INTERNAL; 2346 return; 2347 } 2348 2349 // Was workaround bug 2350 // 4812902: popFrame hangs if the method is waiting at a synchronize 2351 // Catch this condition and return an error to avoid hanging. 2352 // Now JVMTI spec allows an implementation to bail out with an opaque frame error. 2353 OSThread* osThread = java_thread->osthread(); 2354 if (osThread->get_state() == MONITOR_WAIT) { 2355 _result = JVMTI_ERROR_OPAQUE_FRAME; 2356 return; 2357 } 2358 2359 ResourceMark rm(current_thread); 2360 // Check if there is more than one Java frame in this thread, that the top two frames 2361 // are Java (not native) frames, and that there is no intervening VM frame 2362 int frame_count = 0; 2363 bool is_interpreted[2]; 2364 intptr_t *frame_sp[2]; 2365 // The 2-nd arg of constructor is needed to stop iterating at java entry frame. 2366 for (vframeStream vfs(java_thread, true, false /* process_frames */); !vfs.at_end(); vfs.next()) { 2367 methodHandle mh(current_thread, vfs.method()); 2368 if (mh->is_native()) { 2369 _result = JVMTI_ERROR_OPAQUE_FRAME; 2370 return; 2371 } 2372 is_interpreted[frame_count] = vfs.is_interpreted_frame(); 2373 frame_sp[frame_count] = vfs.frame_id(); 2374 if (++frame_count > 1) break; 2375 } 2376 if (frame_count < 2) { 2377 // We haven't found two adjacent non-native Java frames on the top. 2378 // There can be two situations here: 2379 // 1. There are no more java frames 2380 // 2. Two top java frames are separated by non-java native frames 2381 if (JvmtiEnvBase::jvf_for_thread_and_depth(java_thread, 1) == nullptr) { 2382 _result = JVMTI_ERROR_NO_MORE_FRAMES; 2383 return; 2384 } else { 2385 // Intervening non-java native or VM frames separate java frames. 2386 // Current implementation does not support this. See bug #5031735. 2387 // In theory it is possible to pop frames in such cases. 2388 _result = JVMTI_ERROR_OPAQUE_FRAME; 2389 return; 2390 } 2391 } 2392 2393 // If any of the top 2 frames is a compiled one, need to deoptimize it 2394 for (int i = 0; i < 2; i++) { 2395 if (!is_interpreted[i]) { 2396 Deoptimization::deoptimize_frame(java_thread, frame_sp[i]); 2397 } 2398 } 2399 2400 // Update the thread state to reflect that the top frame is popped 2401 // so that cur_stack_depth is maintained properly and all frameIDs 2402 // are invalidated. 2403 // The current frame will be popped later when the suspended thread 2404 // is resumed and right before returning from VM to Java. 2405 // (see call_VM_base() in assembler_<cpu>.cpp). 2406 2407 // It's fine to update the thread state here because no JVMTI events 2408 // shall be posted for this PopFrame. 2409 2410 _state->update_for_pop_top_frame(); 2411 java_thread->set_popframe_condition(JavaThread::popframe_pending_bit); 2412 // Set pending step flag for this popframe and it is cleared when next 2413 // step event is posted. 2414 _state->set_pending_step_for_popframe(); 2415 _result = JVMTI_ERROR_NONE; 2416 } 2417 2418 void 2419 SetFramePopClosure::do_thread(Thread *target) { 2420 Thread* current = Thread::current(); 2421 ResourceMark rm(current); // vframes are resource allocated 2422 JavaThread* java_thread = JavaThread::cast(target); 2423 2424 if (java_thread->is_exiting()) { 2425 return; // JVMTI_ERROR_THREAD_NOT_ALIVE (default) 2426 } 2427 2428 if (!_self && !java_thread->is_suspended()) { 2429 _result = JVMTI_ERROR_THREAD_NOT_SUSPENDED; 2430 return; 2431 } 2432 if (!java_thread->has_last_Java_frame()) { 2433 _result = JVMTI_ERROR_NO_MORE_FRAMES; 2434 return; 2435 } 2436 assert(_state->get_thread_or_saved() == java_thread, "Must be"); 2437 2438 RegisterMap reg_map(java_thread, 2439 RegisterMap::UpdateMap::include, 2440 RegisterMap::ProcessFrames::skip, 2441 RegisterMap::WalkContinuation::include); 2442 javaVFrame* jvf = JvmtiEnvBase::get_cthread_last_java_vframe(java_thread, ®_map); 2443 _result = ((JvmtiEnvBase*)_env)->set_frame_pop(_state, jvf, _depth); 2444 } 2445 2446 void 2447 SetFramePopClosure::do_vthread(Handle target_h) { 2448 Thread* current = Thread::current(); 2449 ResourceMark rm(current); // vframes are resource allocated 2450 2451 if (!_self && !JvmtiVTSuspender::is_vthread_suspended(target_h())) { 2452 _result = JVMTI_ERROR_THREAD_NOT_SUSPENDED; 2453 return; 2454 } 2455 javaVFrame *jvf = JvmtiEnvBase::get_vthread_jvf(target_h()); 2456 _result = ((JvmtiEnvBase*)_env)->set_frame_pop(_state, jvf, _depth); 2457 } 2458 2459 void 2460 GetOwnedMonitorInfoClosure::do_thread(Thread *target) { 2461 JavaThread *jt = JavaThread::cast(target); 2462 if (!jt->is_exiting() && (jt->threadObj() != nullptr)) { 2463 _result = ((JvmtiEnvBase *)_env)->get_owned_monitors(_calling_thread, 2464 jt, 2465 _owned_monitors_list); 2466 } 2467 } 2468 2469 void 2470 GetCurrentContendedMonitorClosure::do_thread(Thread *target) { 2471 JavaThread *jt = JavaThread::cast(target); 2472 if (!jt->is_exiting() && (jt->threadObj() != nullptr)) { 2473 _result = ((JvmtiEnvBase *)_env)->get_current_contended_monitor(_calling_thread, 2474 jt, 2475 _owned_monitor_ptr, 2476 _is_virtual); 2477 } 2478 } 2479 2480 void 2481 GetStackTraceClosure::do_thread(Thread *target) { 2482 Thread* current = Thread::current(); 2483 ResourceMark rm(current); 2484 2485 JavaThread *jt = JavaThread::cast(target); 2486 if (!jt->is_exiting() && jt->threadObj() != nullptr) { 2487 _result = ((JvmtiEnvBase *)_env)->get_stack_trace(jt, 2488 _start_depth, _max_count, 2489 _frame_buffer, _count_ptr); 2490 } 2491 } 2492 2493 void 2494 GetStackTraceClosure::do_vthread(Handle target_h) { 2495 Thread* current = Thread::current(); 2496 ResourceMark rm(current); 2497 2498 javaVFrame *jvf = JvmtiEnvBase::get_vthread_jvf(target_h()); 2499 _result = ((JvmtiEnvBase *)_env)->get_stack_trace(jvf, 2500 _start_depth, _max_count, 2501 _frame_buffer, _count_ptr); 2502 } 2503 2504 #ifdef ASSERT 2505 void 2506 PrintStackTraceClosure::do_thread_impl(Thread *target) { 2507 JavaThread *java_thread = JavaThread::cast(target); 2508 Thread *current_thread = Thread::current(); 2509 2510 ResourceMark rm (current_thread); 2511 const char* tname = JvmtiTrace::safe_get_thread_name(java_thread); 2512 oop t_oop = java_thread->jvmti_vthread(); 2513 t_oop = t_oop == nullptr ? java_thread->threadObj() : t_oop; 2514 bool is_vt_suspended = java_lang_VirtualThread::is_instance(t_oop) && JvmtiVTSuspender::is_vthread_suspended(t_oop); 2515 2516 log_error(jvmti)("%s(%s) exiting: %d is_susp: %d is_thread_susp: %d is_vthread_susp: %d " 2517 "is_VTMS_transition_disabler: %d, is_in_VTMS_transition = %d\n", 2518 tname, java_thread->name(), java_thread->is_exiting(), 2519 java_thread->is_suspended(), java_thread->is_carrier_thread_suspended(), is_vt_suspended, 2520 java_thread->is_VTMS_transition_disabler(), java_thread->is_in_VTMS_transition()); 2521 2522 if (java_thread->has_last_Java_frame()) { 2523 RegisterMap reg_map(java_thread, 2524 RegisterMap::UpdateMap::include, 2525 RegisterMap::ProcessFrames::include, 2526 RegisterMap::WalkContinuation::skip); 2527 ResourceMark rm(current_thread); 2528 HandleMark hm(current_thread); 2529 javaVFrame *jvf = java_thread->last_java_vframe(®_map); 2530 while (jvf != nullptr) { 2531 log_error(jvmti)(" %s:%d", 2532 jvf->method()->external_name(), 2533 jvf->method()->line_number_from_bci(jvf->bci())); 2534 jvf = jvf->java_sender(); 2535 } 2536 } 2537 log_error(jvmti)("\n"); 2538 } 2539 2540 void 2541 PrintStackTraceClosure::do_thread(Thread *target) { 2542 JavaThread *java_thread = JavaThread::cast(target); 2543 Thread *current_thread = Thread::current(); 2544 2545 assert(SafepointSynchronize::is_at_safepoint() || 2546 java_thread->is_handshake_safe_for(current_thread), 2547 "call by myself / at safepoint / at handshake"); 2548 2549 PrintStackTraceClosure::do_thread_impl(target); 2550 } 2551 #endif 2552 2553 void 2554 GetFrameCountClosure::do_thread(Thread *target) { 2555 JavaThread* jt = JavaThread::cast(target); 2556 assert(target == jt, "just checking"); 2557 2558 if (!jt->is_exiting() && jt->threadObj() != nullptr) { 2559 _result = ((JvmtiEnvBase*)_env)->get_frame_count(jt, _count_ptr); 2560 } 2561 } 2562 2563 void 2564 GetFrameCountClosure::do_vthread(Handle target_h) { 2565 _result = ((JvmtiEnvBase*)_env)->get_frame_count(target_h(), _count_ptr); 2566 } 2567 2568 void 2569 GetFrameLocationClosure::do_thread(Thread *target) { 2570 JavaThread *jt = JavaThread::cast(target); 2571 assert(target == jt, "just checking"); 2572 2573 if (!jt->is_exiting() && jt->threadObj() != nullptr) { 2574 _result = ((JvmtiEnvBase*)_env)->get_frame_location(jt, _depth, 2575 _method_ptr, _location_ptr); 2576 } 2577 } 2578 2579 void 2580 GetFrameLocationClosure::do_vthread(Handle target_h) { 2581 _result = ((JvmtiEnvBase*)_env)->get_frame_location(target_h(), _depth, 2582 _method_ptr, _location_ptr); 2583 } 2584 2585 void 2586 VirtualThreadGetOwnedMonitorInfoClosure::do_thread(Thread *target) { 2587 if (!JvmtiEnvBase::is_vthread_alive(_vthread_h())) { 2588 _result = JVMTI_ERROR_THREAD_NOT_ALIVE; 2589 return; 2590 } 2591 JavaThread* java_thread = JavaThread::cast(target); 2592 Thread* cur_thread = Thread::current(); 2593 ResourceMark rm(cur_thread); 2594 HandleMark hm(cur_thread); 2595 2596 javaVFrame *jvf = JvmtiEnvBase::get_vthread_jvf(_vthread_h()); 2597 2598 if (!java_thread->is_exiting() && java_thread->threadObj() != nullptr) { 2599 _result = ((JvmtiEnvBase *)_env)->get_owned_monitors(java_thread, 2600 java_thread, 2601 jvf, 2602 _owned_monitors_list); 2603 } 2604 } 2605 2606 void 2607 VirtualThreadGetThreadClosure::do_thread(Thread *target) { 2608 assert(target->is_Java_thread(), "just checking"); 2609 JavaThread *jt = JavaThread::cast(target); 2610 oop carrier_thread = java_lang_VirtualThread::carrier_thread(_vthread_h()); 2611 *_carrier_thread_ptr = (jthread)JNIHandles::make_local(jt, carrier_thread); 2612 } 2613 2614 void 2615 VirtualThreadGetThreadStateClosure::do_thread(Thread *target) { 2616 assert(target->is_Java_thread(), "just checking"); 2617 int vthread_state = java_lang_VirtualThread::state(_vthread_h()); 2618 oop carrier_thread_oop = java_lang_VirtualThread::carrier_thread(_vthread_h()); 2619 jint state; 2620 2621 if (vthread_state == java_lang_VirtualThread::RUNNING && carrier_thread_oop != nullptr) { 2622 state = (jint) java_lang_Thread::get_thread_status(carrier_thread_oop); 2623 JavaThread* java_thread = java_lang_Thread::thread(carrier_thread_oop); 2624 if (java_thread->is_suspended()) { 2625 state |= JVMTI_THREAD_STATE_SUSPENDED; 2626 } 2627 } else { 2628 state = (jint) java_lang_VirtualThread::map_state_to_thread_status(vthread_state); 2629 } 2630 if (java_lang_Thread::interrupted(_vthread_h())) { 2631 state |= JVMTI_THREAD_STATE_INTERRUPTED; 2632 } 2633 *_state_ptr = state; 2634 _result = JVMTI_ERROR_NONE; 2635 }