1 /* 2 * Copyright (c) 1997, 2023, Oracle and/or its affiliates. All rights reserved. 3 * Copyright (c) 2021, Azul Systems, Inc. All rights reserved. 4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 5 * 6 * This code is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License version 2 only, as 8 * published by the Free Software Foundation. 9 * 10 * This code is distributed in the hope that it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 13 * version 2 for more details (a copy is included in the LICENSE file that 14 * accompanied this code). 15 * 16 * You should have received a copy of the GNU General Public License version 17 * 2 along with this work; if not, write to the Free Software Foundation, 18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 19 * 20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 21 * or visit www.oracle.com if you need additional information or have any 22 * questions. 23 * 24 */ 25 26 #include "precompiled.hpp" 27 #include "cds/cds_globals.hpp" 28 #include "cds/metaspaceShared.hpp" 29 #include "classfile/classLoader.hpp" 30 #include "classfile/javaClasses.hpp" 31 #include "classfile/javaThreadStatus.hpp" 32 #include "classfile/systemDictionary.hpp" 33 #include "classfile/vmClasses.hpp" 34 #include "classfile/vmSymbols.hpp" 35 #include "compiler/compileBroker.hpp" 36 #include "compiler/compileTask.hpp" 37 #include "compiler/compilerThread.hpp" 38 #include "gc/shared/barrierSet.hpp" 39 #include "gc/shared/barrierSetNMethod.hpp" 40 #include "gc/shared/gcVMOperations.hpp" 41 #include "gc/shared/oopStorage.hpp" 42 #include "gc/shared/oopStorageSet.hpp" 43 #include "gc/shared/stringdedup/stringDedup.hpp" 44 #include "jfr/jfrEvents.hpp" 45 #include "jvm.h" 46 #include "jvmtifiles/jvmtiEnv.hpp" 47 #include "logging/log.hpp" 48 #include "logging/logAsyncWriter.hpp" 49 #include "logging/logConfiguration.hpp" 50 #include "memory/allocation.inline.hpp" 51 #include "memory/iterator.hpp" 52 #include "memory/oopFactory.hpp" 53 #include "memory/resourceArea.hpp" 54 #include "memory/universe.hpp" 55 #include "oops/instanceKlass.hpp" 56 #include "oops/klass.inline.hpp" 57 #include "oops/oop.inline.hpp" 58 #include "oops/symbol.hpp" 59 #include "prims/jvmtiAgentList.hpp" 60 #include "prims/jvm_misc.hpp" 61 #include "runtime/arguments.hpp" 62 #include "runtime/fieldDescriptor.inline.hpp" 63 #include "runtime/flags/jvmFlagLimit.hpp" 64 #include "runtime/handles.inline.hpp" 65 #include "runtime/globals.hpp" 66 #include "runtime/interfaceSupport.inline.hpp" 67 #include "runtime/java.hpp" 68 #include "runtime/javaCalls.hpp" 69 #include "runtime/javaThread.inline.hpp" 70 #include "runtime/jniHandles.inline.hpp" 71 #include "runtime/jniPeriodicChecker.hpp" 72 #include "runtime/lockStack.inline.hpp" 73 #include "runtime/monitorDeflationThread.hpp" 74 #include "runtime/mutexLocker.hpp" 75 #include "runtime/nonJavaThread.hpp" 76 #include "runtime/objectMonitor.inline.hpp" 77 #include "runtime/osThread.hpp" 78 #include "runtime/safepoint.hpp" 79 #include "runtime/safepointMechanism.inline.hpp" 80 #include "runtime/safepointVerifiers.hpp" 81 #include "runtime/serviceThread.hpp" 82 #include "runtime/sharedRuntime.hpp" 83 #include "runtime/statSampler.hpp" 84 #include "runtime/stubCodeGenerator.hpp" 85 #include "runtime/thread.inline.hpp" 86 #include "runtime/threads.hpp" 87 #include "runtime/threadSMR.inline.hpp" 88 #include "runtime/timer.hpp" 89 #include "runtime/timerTrace.hpp" 90 #include "runtime/trimNativeHeap.hpp" 91 #include "runtime/vmOperations.hpp" 92 #include "runtime/vm_version.hpp" 93 #include "services/attachListener.hpp" 94 #include "services/management.hpp" 95 #include "services/memTracker.hpp" 96 #include "services/threadIdTable.hpp" 97 #include "services/threadService.hpp" 98 #include "utilities/dtrace.hpp" 99 #include "utilities/events.hpp" 100 #include "utilities/macros.hpp" 101 #include "utilities/vmError.hpp" 102 #if INCLUDE_JVMCI 103 #include "jvmci/jvmci.hpp" 104 #include "jvmci/jvmciEnv.hpp" 105 #endif 106 #ifdef COMPILER2 107 #include "opto/idealGraphPrinter.hpp" 108 #endif 109 #if INCLUDE_RTM_OPT 110 #include "runtime/rtmLocking.hpp" 111 #endif 112 #if INCLUDE_JFR 113 #include "jfr/jfr.hpp" 114 #endif 115 #if INCLUDE_VM_STRUCTS 116 #include "runtime/vmStructs.hpp" 117 #endif 118 119 // Initialization after module runtime initialization 120 void universe_post_module_init(); // must happen after call_initPhase2 121 122 123 static void initialize_class(Symbol* class_name, TRAPS) { 124 Klass* klass = SystemDictionary::resolve_or_fail(class_name, true, CHECK); 125 InstanceKlass::cast(klass)->initialize(CHECK); 126 } 127 128 129 // Creates the initial ThreadGroup 130 static Handle create_initial_thread_group(TRAPS) { 131 Handle system_instance = JavaCalls::construct_new_instance( 132 vmClasses::ThreadGroup_klass(), 133 vmSymbols::void_method_signature(), 134 CHECK_NH); 135 Universe::set_system_thread_group(system_instance()); 136 137 Handle string = java_lang_String::create_from_str("main", CHECK_NH); 138 Handle main_instance = JavaCalls::construct_new_instance( 139 vmClasses::ThreadGroup_klass(), 140 vmSymbols::threadgroup_string_void_signature(), 141 system_instance, 142 string, 143 CHECK_NH); 144 return main_instance; 145 } 146 147 // Creates the initial Thread, and sets it to running. 148 static void create_initial_thread(Handle thread_group, JavaThread* thread, 149 TRAPS) { 150 InstanceKlass* ik = vmClasses::Thread_klass(); 151 assert(ik->is_initialized(), "must be"); 152 instanceHandle thread_oop = ik->allocate_instance_handle(CHECK); 153 154 // Cannot use JavaCalls::construct_new_instance because the java.lang.Thread 155 // constructor calls Thread.current(), which must be set here for the 156 // initial thread. 157 java_lang_Thread::set_thread(thread_oop(), thread); 158 thread->set_threadOopHandles(thread_oop()); 159 160 Handle string = java_lang_String::create_from_str("main", CHECK); 161 162 JavaValue result(T_VOID); 163 JavaCalls::call_special(&result, thread_oop, 164 ik, 165 vmSymbols::object_initializer_name(), 166 vmSymbols::threadgroup_string_void_signature(), 167 thread_group, 168 string, 169 CHECK); 170 171 // Set thread status to running since main thread has 172 // been started and running. 173 java_lang_Thread::set_thread_status(thread_oop(), 174 JavaThreadStatus::RUNNABLE); 175 } 176 177 // Extract version and vendor specific information from 178 // java.lang.VersionProps fields. 179 // Returned char* is allocated in the thread's resource area 180 // so must be copied for permanency. 181 static const char* get_java_version_info(InstanceKlass* ik, 182 Symbol* field_name) { 183 fieldDescriptor fd; 184 bool found = ik != nullptr && 185 ik->find_local_field(field_name, 186 vmSymbols::string_signature(), &fd); 187 if (found) { 188 oop name_oop = ik->java_mirror()->obj_field(fd.offset()); 189 if (name_oop == nullptr) { 190 return nullptr; 191 } 192 const char* name = java_lang_String::as_utf8_string(name_oop); 193 return name; 194 } else { 195 return nullptr; 196 } 197 } 198 199 // ======= Threads ======== 200 201 // The Threads class links together all active threads, and provides 202 // operations over all threads. It is protected by the Threads_lock, 203 // which is also used in other global contexts like safepointing. 204 // ThreadsListHandles are used to safely perform operations on one 205 // or more threads without the risk of the thread exiting during the 206 // operation. 207 // 208 // Note: The Threads_lock is currently more widely used than we 209 // would like. We are actively migrating Threads_lock uses to other 210 // mechanisms in order to reduce Threads_lock contention. 211 212 int Threads::_number_of_threads = 0; 213 int Threads::_number_of_non_daemon_threads = 0; 214 int Threads::_return_code = 0; 215 uintx Threads::_thread_claim_token = 1; // Never zero. 216 217 #ifdef ASSERT 218 bool Threads::_vm_complete = false; 219 #endif 220 221 // General purpose hook into Java code, run once when the VM is initialized. 222 // The Java library method itself may be changed independently from the VM. 223 static void call_postVMInitHook(TRAPS) { 224 Klass* klass = SystemDictionary::resolve_or_null(vmSymbols::jdk_internal_vm_PostVMInitHook(), THREAD); 225 if (klass != nullptr) { 226 JavaValue result(T_VOID); 227 JavaCalls::call_static(&result, klass, vmSymbols::run_method_name(), 228 vmSymbols::void_method_signature(), 229 CHECK); 230 } 231 } 232 233 // All NonJavaThreads (i.e., every non-JavaThread in the system). 234 void Threads::non_java_threads_do(ThreadClosure* tc) { 235 NoSafepointVerifier nsv; 236 for (NonJavaThread::Iterator njti; !njti.end(); njti.step()) { 237 tc->do_thread(njti.current()); 238 } 239 } 240 241 // All JavaThreads 242 #define ALL_JAVA_THREADS(X) \ 243 for (JavaThread* X : *ThreadsSMRSupport::get_java_thread_list()) 244 245 // All JavaThreads 246 void Threads::java_threads_do(ThreadClosure* tc) { 247 assert_locked_or_safepoint(Threads_lock); 248 // ALL_JAVA_THREADS iterates through all JavaThreads. 249 ALL_JAVA_THREADS(p) { 250 tc->do_thread(p); 251 } 252 } 253 254 // All JavaThreads + all non-JavaThreads (i.e., every thread in the system). 255 void Threads::threads_do(ThreadClosure* tc) { 256 assert_locked_or_safepoint(Threads_lock); 257 java_threads_do(tc); 258 non_java_threads_do(tc); 259 } 260 261 void Threads::possibly_parallel_threads_do(bool is_par, ThreadClosure* tc) { 262 assert_at_safepoint(); 263 264 uintx claim_token = Threads::thread_claim_token(); 265 ALL_JAVA_THREADS(p) { 266 if (p->claim_threads_do(is_par, claim_token)) { 267 tc->do_thread(p); 268 } 269 } 270 for (NonJavaThread::Iterator njti; !njti.end(); njti.step()) { 271 Thread* current = njti.current(); 272 if (current->claim_threads_do(is_par, claim_token)) { 273 tc->do_thread(current); 274 } 275 } 276 } 277 278 // The system initialization in the library has three phases. 279 // 280 // Phase 1: java.lang.System class initialization 281 // java.lang.System is a primordial class loaded and initialized 282 // by the VM early during startup. java.lang.System.<clinit> 283 // only does registerNatives and keeps the rest of the class 284 // initialization work later until thread initialization completes. 285 // 286 // System.initPhase1 initializes the system properties, the static 287 // fields in, out, and err. Set up java signal handlers, OS-specific 288 // system settings, and thread group of the main thread. 289 static void call_initPhase1(TRAPS) { 290 Klass* klass = vmClasses::System_klass(); 291 JavaValue result(T_VOID); 292 JavaCalls::call_static(&result, klass, vmSymbols::initPhase1_name(), 293 vmSymbols::void_method_signature(), CHECK); 294 } 295 296 // Phase 2. Module system initialization 297 // This will initialize the module system. Only java.base classes 298 // can be loaded until phase 2 completes. 299 // 300 // Call System.initPhase2 after the compiler initialization and jsr292 301 // classes get initialized because module initialization runs a lot of java 302 // code, that for performance reasons, should be compiled. Also, this will 303 // enable the startup code to use lambda and other language features in this 304 // phase and onward. 305 // 306 // After phase 2, The VM will begin search classes from -Xbootclasspath/a. 307 static void call_initPhase2(TRAPS) { 308 TraceTime timer("Initialize module system", TRACETIME_LOG(Info, startuptime)); 309 310 Klass* klass = vmClasses::System_klass(); 311 312 JavaValue result(T_INT); 313 JavaCallArguments args; 314 args.push_int(DisplayVMOutputToStderr); 315 args.push_int(log_is_enabled(Debug, init)); // print stack trace if exception thrown 316 JavaCalls::call_static(&result, klass, vmSymbols::initPhase2_name(), 317 vmSymbols::boolean_boolean_int_signature(), &args, CHECK); 318 if (result.get_jint() != JNI_OK) { 319 vm_exit_during_initialization(); // no message or exception 320 } 321 322 universe_post_module_init(); 323 } 324 325 // Phase 3. final setup - set security manager, system class loader and TCCL 326 // 327 // This will instantiate and set the security manager, set the system class 328 // loader as well as the thread context class loader. The security manager 329 // and system class loader may be a custom class loaded from -Xbootclasspath/a, 330 // other modules or the application's classpath. 331 static void call_initPhase3(TRAPS) { 332 Klass* klass = vmClasses::System_klass(); 333 JavaValue result(T_VOID); 334 JavaCalls::call_static(&result, klass, vmSymbols::initPhase3_name(), 335 vmSymbols::void_method_signature(), CHECK); 336 } 337 338 void Threads::initialize_java_lang_classes(JavaThread* main_thread, TRAPS) { 339 TraceTime timer("Initialize java.lang classes", TRACETIME_LOG(Info, startuptime)); 340 341 initialize_class(vmSymbols::java_lang_String(), CHECK); 342 343 // Inject CompactStrings value after the static initializers for String ran. 344 java_lang_String::set_compact_strings(CompactStrings); 345 346 // Initialize java_lang.System (needed before creating the thread) 347 initialize_class(vmSymbols::java_lang_System(), CHECK); 348 // The VM creates & returns objects of this class. Make sure it's initialized. 349 initialize_class(vmSymbols::java_lang_Class(), CHECK); 350 initialize_class(vmSymbols::java_lang_ThreadGroup(), CHECK); 351 Handle thread_group = create_initial_thread_group(CHECK); 352 Universe::set_main_thread_group(thread_group()); 353 initialize_class(vmSymbols::java_lang_Thread(), CHECK); 354 create_initial_thread(thread_group, main_thread, CHECK); 355 356 // The VM creates objects of this class. 357 initialize_class(vmSymbols::java_lang_Module(), CHECK); 358 359 #ifdef ASSERT 360 InstanceKlass *k = vmClasses::UnsafeConstants_klass(); 361 assert(k->is_not_initialized(), "UnsafeConstants should not already be initialized"); 362 #endif 363 364 // initialize the hardware-specific constants needed by Unsafe 365 initialize_class(vmSymbols::jdk_internal_misc_UnsafeConstants(), CHECK); 366 jdk_internal_misc_UnsafeConstants::set_unsafe_constants(); 367 368 // The VM preresolves methods to these classes. Make sure that they get initialized 369 initialize_class(vmSymbols::java_lang_reflect_Method(), CHECK); 370 initialize_class(vmSymbols::java_lang_ref_Finalizer(), CHECK); 371 372 // Phase 1 of the system initialization in the library, java.lang.System class initialization 373 call_initPhase1(CHECK); 374 375 // Get the Java runtime name, version, and vendor info after java.lang.System is initialized. 376 // Some values are actually configure-time constants but some can be set via the jlink tool and 377 // so must be read dynamically. We treat them all the same. 378 InstanceKlass* ik = SystemDictionary::find_instance_klass(THREAD, vmSymbols::java_lang_VersionProps(), 379 Handle(), Handle()); 380 { 381 ResourceMark rm(main_thread); 382 JDK_Version::set_java_version(get_java_version_info(ik, vmSymbols::java_version_name())); 383 384 JDK_Version::set_runtime_name(get_java_version_info(ik, vmSymbols::java_runtime_name_name())); 385 386 JDK_Version::set_runtime_version(get_java_version_info(ik, vmSymbols::java_runtime_version_name())); 387 388 JDK_Version::set_runtime_vendor_version(get_java_version_info(ik, vmSymbols::java_runtime_vendor_version_name())); 389 390 JDK_Version::set_runtime_vendor_vm_bug_url(get_java_version_info(ik, vmSymbols::java_runtime_vendor_vm_bug_url_name())); 391 } 392 393 // an instance of OutOfMemory exception has been allocated earlier 394 initialize_class(vmSymbols::java_lang_OutOfMemoryError(), CHECK); 395 initialize_class(vmSymbols::java_lang_NullPointerException(), CHECK); 396 initialize_class(vmSymbols::java_lang_ClassCastException(), CHECK); 397 initialize_class(vmSymbols::java_lang_ArrayStoreException(), CHECK); 398 initialize_class(vmSymbols::java_lang_ArithmeticException(), CHECK); 399 initialize_class(vmSymbols::java_lang_StackOverflowError(), CHECK); 400 initialize_class(vmSymbols::java_lang_IllegalMonitorStateException(), CHECK); 401 initialize_class(vmSymbols::java_lang_IllegalArgumentException(), CHECK); 402 } 403 404 void Threads::initialize_jsr292_core_classes(TRAPS) { 405 TraceTime timer("Initialize java.lang.invoke classes", TRACETIME_LOG(Info, startuptime)); 406 407 initialize_class(vmSymbols::java_lang_invoke_MethodHandle(), CHECK); 408 initialize_class(vmSymbols::java_lang_invoke_ResolvedMethodName(), CHECK); 409 initialize_class(vmSymbols::java_lang_invoke_MemberName(), CHECK); 410 initialize_class(vmSymbols::java_lang_invoke_MethodHandleNatives(), CHECK); 411 } 412 413 jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) { 414 extern void JDK_Version_init(); 415 416 // Preinitialize version info. 417 VM_Version::early_initialize(); 418 419 // Check version 420 if (!is_supported_jni_version(args->version)) return JNI_EVERSION; 421 422 // Initialize library-based TLS 423 ThreadLocalStorage::init(); 424 425 // Initialize the output stream module 426 ostream_init(); 427 428 // Process java launcher properties. 429 Arguments::process_sun_java_launcher_properties(args); 430 431 // Initialize the os module 432 os::init(); 433 434 MACOS_AARCH64_ONLY(os::current_thread_enable_wx(WXWrite)); 435 436 // Record VM creation timing statistics 437 TraceVmCreationTime create_vm_timer; 438 create_vm_timer.start(); 439 440 // Initialize system properties. 441 Arguments::init_system_properties(); 442 443 // So that JDK version can be used as a discriminator when parsing arguments 444 JDK_Version_init(); 445 446 // Update/Initialize System properties after JDK version number is known 447 Arguments::init_version_specific_system_properties(); 448 449 // Make sure to initialize log configuration *before* parsing arguments 450 LogConfiguration::initialize(create_vm_timer.begin_time()); 451 452 // Parse arguments 453 // Note: this internally calls os::init_container_support() 454 jint parse_result = Arguments::parse(args); 455 if (parse_result != JNI_OK) return parse_result; 456 457 // Initialize NMT right after argument parsing to keep the pre-NMT-init window small. 458 MemTracker::initialize(); 459 460 os::init_before_ergo(); 461 462 jint ergo_result = Arguments::apply_ergo(); 463 if (ergo_result != JNI_OK) return ergo_result; 464 465 // Final check of all ranges after ergonomics which may change values. 466 if (!JVMFlagLimit::check_all_ranges()) { 467 return JNI_EINVAL; 468 } 469 470 // Final check of all 'AfterErgo' constraints after ergonomics which may change values. 471 bool constraint_result = JVMFlagLimit::check_all_constraints(JVMFlagConstraintPhase::AfterErgo); 472 if (!constraint_result) { 473 return JNI_EINVAL; 474 } 475 476 if (PauseAtStartup) { 477 os::pause(); 478 } 479 480 HOTSPOT_VM_INIT_BEGIN(); 481 482 // Timing (must come after argument parsing) 483 TraceTime timer("Create VM", TRACETIME_LOG(Info, startuptime)); 484 485 // Initialize the os module after parsing the args 486 jint os_init_2_result = os::init_2(); 487 if (os_init_2_result != JNI_OK) return os_init_2_result; 488 489 #ifdef CAN_SHOW_REGISTERS_ON_ASSERT 490 // Initialize assert poison page mechanism. 491 if (ShowRegistersOnAssert) { 492 initialize_assert_poison(); 493 } 494 #endif // CAN_SHOW_REGISTERS_ON_ASSERT 495 496 SafepointMechanism::initialize(); 497 498 jint adjust_after_os_result = Arguments::adjust_after_os(); 499 if (adjust_after_os_result != JNI_OK) return adjust_after_os_result; 500 501 // Initialize output stream logging 502 ostream_init_log(); 503 504 // Should happen before any agent attaches and pokes into vmStructs 505 #if INCLUDE_VM_STRUCTS 506 if (UseCompactObjectHeaders) { 507 VMStructs::compact_headers_overrides(); 508 } 509 #endif 510 511 // Launch -agentlib/-agentpath and converted -Xrun agents 512 JvmtiAgentList::load_agents(); 513 514 // Initialize Threads state 515 _number_of_threads = 0; 516 _number_of_non_daemon_threads = 0; 517 518 // Initialize global data structures and create system classes in heap 519 vm_init_globals(); 520 521 #if INCLUDE_JVMCI 522 if (JVMCICounterSize > 0) { 523 JavaThread::_jvmci_old_thread_counters = NEW_C_HEAP_ARRAY(jlong, JVMCICounterSize, mtJVMCI); 524 memset(JavaThread::_jvmci_old_thread_counters, 0, sizeof(jlong) * JVMCICounterSize); 525 } else { 526 JavaThread::_jvmci_old_thread_counters = nullptr; 527 } 528 #endif // INCLUDE_JVMCI 529 530 // Initialize OopStorage for threadObj 531 JavaThread::_thread_oop_storage = OopStorageSet::create_strong("Thread OopStorage", mtThread); 532 533 // Attach the main thread to this os thread 534 JavaThread* main_thread = new JavaThread(); 535 main_thread->set_thread_state(_thread_in_vm); 536 main_thread->initialize_thread_current(); 537 // must do this before set_active_handles 538 main_thread->record_stack_base_and_size(); 539 main_thread->register_thread_stack_with_NMT(); 540 main_thread->set_active_handles(JNIHandleBlock::allocate_block()); 541 MACOS_AARCH64_ONLY(main_thread->init_wx()); 542 543 if (!main_thread->set_as_starting_thread()) { 544 vm_shutdown_during_initialization( 545 "Failed necessary internal allocation. Out of swap space"); 546 main_thread->smr_delete(); 547 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again 548 return JNI_ENOMEM; 549 } 550 551 // Enable guard page *after* os::create_main_thread(), otherwise it would 552 // crash Linux VM, see notes in os_linux.cpp. 553 main_thread->stack_overflow_state()->create_stack_guard_pages(); 554 555 // Initialize Java-Level synchronization subsystem 556 ObjectMonitor::Initialize(); 557 ObjectSynchronizer::initialize(); 558 559 // Initialize global modules 560 jint status = init_globals(); 561 if (status != JNI_OK) { 562 main_thread->smr_delete(); 563 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again 564 return status; 565 } 566 567 // Create WatcherThread as soon as we can since we need it in case 568 // of hangs during error reporting. 569 WatcherThread::start(); 570 571 // Add main_thread to threads list to finish barrier setup with 572 // on_thread_attach. Should be before starting to build Java objects in 573 // init_globals2, which invokes barriers. 574 { 575 MutexLocker mu(Threads_lock); 576 Threads::add(main_thread); 577 } 578 579 status = init_globals2(); 580 if (status != JNI_OK) { 581 Threads::remove(main_thread, false); 582 // It is possible that we managed to fully initialize Universe but have then 583 // failed by throwing an exception. In that case our caller JNI_CreateJavaVM 584 // will want to report it, so we can't delete the main thread. 585 if (!main_thread->has_pending_exception()) { 586 main_thread->smr_delete(); 587 } 588 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again 589 return status; 590 } 591 592 JFR_ONLY(Jfr::on_create_vm_1();) 593 594 // Should be done after the heap is fully created 595 main_thread->cache_global_variables(); 596 597 // Any JVMTI raw monitors entered in onload will transition into 598 // real raw monitor. VM is setup enough here for raw monitor enter. 599 JvmtiExport::transition_pending_onload_raw_monitors(); 600 601 // Create the VMThread 602 { TraceTime timer("Start VMThread", TRACETIME_LOG(Info, startuptime)); 603 604 VMThread::create(); 605 VMThread* vmthread = VMThread::vm_thread(); 606 607 if (!os::create_thread(vmthread, os::vm_thread)) { 608 vm_exit_during_initialization("Cannot create VM thread. " 609 "Out of system resources."); 610 } 611 612 // Wait for the VM thread to become ready, and VMThread::run to initialize 613 // Monitors can have spurious returns, must always check another state flag 614 { 615 MonitorLocker ml(Notify_lock); 616 os::start_thread(vmthread); 617 while (!vmthread->is_running()) { 618 ml.wait(); 619 } 620 } 621 } 622 623 assert(Universe::is_fully_initialized(), "not initialized"); 624 if (VerifyDuringStartup) { 625 // Make sure we're starting with a clean slate. 626 VM_Verify verify_op; 627 VMThread::execute(&verify_op); 628 } 629 630 // We need this to update the java.vm.info property in case any flags used 631 // to initially define it have been changed. This is needed for both CDS 632 // since UseSharedSpaces may be changed after java.vm.info 633 // is initially computed. See Abstract_VM_Version::vm_info_string(). 634 // This update must happen before we initialize the java classes, but 635 // after any initialization logic that might modify the flags. 636 Arguments::update_vm_info_property(VM_Version::vm_info_string()); 637 638 JavaThread* THREAD = JavaThread::current(); // For exception macros. 639 HandleMark hm(THREAD); 640 641 // Always call even when there are not JVMTI environments yet, since environments 642 // may be attached late and JVMTI must track phases of VM execution 643 JvmtiExport::enter_early_start_phase(); 644 645 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents. 646 JvmtiExport::post_early_vm_start(); 647 648 // Launch -Xrun agents early if EagerXrunInit is set 649 if (EagerXrunInit) { 650 JvmtiAgentList::load_xrun_agents(); 651 } 652 653 initialize_java_lang_classes(main_thread, CHECK_JNI_ERR); 654 655 quicken_jni_functions(); 656 657 // No more stub generation allowed after that point. 658 StubCodeDesc::freeze(); 659 660 // Set flag that basic initialization has completed. Used by exceptions and various 661 // debug stuff, that does not work until all basic classes have been initialized. 662 set_init_completed(); 663 664 LogConfiguration::post_initialize(); 665 Metaspace::post_initialize(); 666 MutexLocker::post_initialize(); 667 668 HOTSPOT_VM_INIT_END(); 669 670 // record VM initialization completion time 671 #if INCLUDE_MANAGEMENT 672 Management::record_vm_init_completed(); 673 #endif // INCLUDE_MANAGEMENT 674 675 log_info(os)("Initialized VM with process ID %d", os::current_process_id()); 676 677 // Signal Dispatcher needs to be started before VMInit event is posted 678 os::initialize_jdk_signal_support(CHECK_JNI_ERR); 679 680 // Start Attach Listener if +StartAttachListener or it can't be started lazily 681 if (!DisableAttachMechanism) { 682 AttachListener::vm_start(); 683 if (StartAttachListener || AttachListener::init_at_startup()) { 684 AttachListener::init(); 685 } 686 } 687 688 // Launch -Xrun agents if EagerXrunInit is not set. 689 if (!EagerXrunInit) { 690 JvmtiAgentList::load_xrun_agents(); 691 } 692 693 Arena::start_chunk_pool_cleaner_task(); 694 695 // Start the service thread 696 // The service thread enqueues JVMTI deferred events and does various hashtable 697 // and other cleanups. Needs to start before the compilers start posting events. 698 ServiceThread::initialize(); 699 700 // Start the monitor deflation thread: 701 MonitorDeflationThread::initialize(); 702 703 // initialize compiler(s) 704 #if defined(COMPILER1) || COMPILER2_OR_JVMCI 705 #if INCLUDE_JVMCI 706 bool force_JVMCI_intialization = false; 707 if (EnableJVMCI) { 708 // Initialize JVMCI eagerly when it is explicitly requested. 709 // Or when JVMCILibDumpJNIConfig or JVMCIPrintProperties is enabled. 710 force_JVMCI_intialization = EagerJVMCI || JVMCIPrintProperties || JVMCILibDumpJNIConfig; 711 712 if (!force_JVMCI_intialization) { 713 // 8145270: Force initialization of JVMCI runtime otherwise requests for blocking 714 // compilations via JVMCI will not actually block until JVMCI is initialized. 715 force_JVMCI_intialization = UseJVMCICompiler && (!UseInterpreter || !BackgroundCompilation); 716 } 717 } 718 #endif 719 CompileBroker::compilation_init_phase1(CHECK_JNI_ERR); 720 // Postpone completion of compiler initialization to after JVMCI 721 // is initialized to avoid timeouts of blocking compilations. 722 if (JVMCI_ONLY(!force_JVMCI_intialization) NOT_JVMCI(true)) { 723 CompileBroker::compilation_init_phase2(); 724 } 725 #endif 726 727 // Start string deduplication thread if requested. 728 if (StringDedup::is_enabled()) { 729 StringDedup::start(); 730 } 731 732 // Pre-initialize some JSR292 core classes to avoid deadlock during class loading. 733 // It is done after compilers are initialized, because otherwise compilations of 734 // signature polymorphic MH intrinsics can be missed 735 // (see SystemDictionary::find_method_handle_intrinsic). 736 initialize_jsr292_core_classes(CHECK_JNI_ERR); 737 738 // This will initialize the module system. Only java.base classes can be 739 // loaded until phase 2 completes 740 call_initPhase2(CHECK_JNI_ERR); 741 742 JFR_ONLY(Jfr::on_create_vm_2();) 743 744 // Always call even when there are not JVMTI environments yet, since environments 745 // may be attached late and JVMTI must track phases of VM execution 746 JvmtiExport::enter_start_phase(); 747 748 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents. 749 JvmtiExport::post_vm_start(); 750 751 // Final system initialization including security manager and system class loader 752 call_initPhase3(CHECK_JNI_ERR); 753 754 // cache the system and platform class loaders 755 SystemDictionary::compute_java_loaders(CHECK_JNI_ERR); 756 757 #if INCLUDE_CDS 758 // capture the module path info from the ModuleEntryTable 759 ClassLoader::initialize_module_path(THREAD); 760 if (HAS_PENDING_EXCEPTION) { 761 java_lang_Throwable::print(PENDING_EXCEPTION, tty); 762 vm_exit_during_initialization("ClassLoader::initialize_module_path() failed unexpectedly"); 763 } 764 #endif 765 766 #if INCLUDE_JVMCI 767 if (force_JVMCI_intialization) { 768 JVMCI::initialize_compiler(CHECK_JNI_ERR); 769 CompileBroker::compilation_init_phase2(); 770 } 771 #endif 772 773 if (NativeHeapTrimmer::enabled()) { 774 NativeHeapTrimmer::initialize(); 775 } 776 777 // Always call even when there are not JVMTI environments yet, since environments 778 // may be attached late and JVMTI must track phases of VM execution 779 JvmtiExport::enter_live_phase(); 780 781 // Make perfmemory accessible 782 PerfMemory::set_accessible(true); 783 784 // Notify JVMTI agents that VM initialization is complete - nop if no agents. 785 JvmtiExport::post_vm_initialized(); 786 787 JFR_ONLY(Jfr::on_create_vm_3();) 788 789 #if INCLUDE_MANAGEMENT 790 Management::initialize(THREAD); 791 792 if (HAS_PENDING_EXCEPTION) { 793 // management agent fails to start possibly due to 794 // configuration problem and is responsible for printing 795 // stack trace if appropriate. Simply exit VM. 796 vm_exit(1); 797 } 798 #endif // INCLUDE_MANAGEMENT 799 800 StatSampler::engage(); 801 if (CheckJNICalls) JniPeriodicChecker::engage(); 802 803 #if INCLUDE_RTM_OPT 804 RTMLockingCounters::init(); 805 #endif 806 807 call_postVMInitHook(THREAD); 808 // The Java side of PostVMInitHook.run must deal with all 809 // exceptions and provide means of diagnosis. 810 if (HAS_PENDING_EXCEPTION) { 811 CLEAR_PENDING_EXCEPTION; 812 } 813 814 // Let WatcherThread run all registered periodic tasks now. 815 // NOTE: All PeriodicTasks should be registered by now. If they 816 // aren't, late joiners might appear to start slowly (we might 817 // take a while to process their first tick). 818 WatcherThread::run_all_tasks(); 819 820 create_vm_timer.end(); 821 #ifdef ASSERT 822 _vm_complete = true; 823 #endif 824 825 if (DumpSharedSpaces) { 826 MetaspaceShared::preload_and_dump(); 827 } 828 829 return JNI_OK; 830 } 831 832 // Threads::destroy_vm() is normally called from jni_DestroyJavaVM() when 833 // the program falls off the end of main(). Another VM exit path is through 834 // vm_exit() when the program calls System.exit() to return a value or when 835 // there is a serious error in VM. The two shutdown paths are not exactly 836 // the same, but they share Shutdown.shutdown() at Java level and before_exit() 837 // and VM_Exit op at VM level. 838 // 839 // Shutdown sequence: 840 // + Shutdown native memory tracking if it is on 841 // + Wait until we are the last non-daemon thread to execute 842 // <-- every thing is still working at this moment --> 843 // + Call java.lang.Shutdown.shutdown(), which will invoke Java level 844 // shutdown hooks 845 // + Call before_exit(), prepare for VM exit 846 // > run VM level shutdown hooks (they are registered through JVM_OnExit(), 847 // currently the only user of this mechanism is File.deleteOnExit()) 848 // > stop StatSampler, watcher thread, 849 // post thread end and vm death events to JVMTI, 850 // stop signal thread 851 // + Call JavaThread::exit(), it will: 852 // > release JNI handle blocks, remove stack guard pages 853 // > remove this thread from Threads list 854 // <-- no more Java code from this thread after this point --> 855 // + Stop VM thread, it will bring the remaining VM to a safepoint and stop 856 // the compiler threads at safepoint 857 // <-- do not use anything that could get blocked by Safepoint --> 858 // + Disable tracing at JNI/JVM barriers 859 // + Set _vm_exited flag for threads that are still running native code 860 // + Call exit_globals() 861 // > deletes tty 862 // > deletes PerfMemory resources 863 // + Delete this thread 864 // + Return to caller 865 866 void Threads::destroy_vm() { 867 JavaThread* thread = JavaThread::current(); 868 869 #ifdef ASSERT 870 _vm_complete = false; 871 #endif 872 // Wait until we are the last non-daemon thread to execute, or 873 // if we are a daemon then wait until the last non-daemon thread has 874 // executed. 875 bool daemon = java_lang_Thread::is_daemon(thread->threadObj()); 876 int expected = daemon ? 0 : 1; 877 { 878 MonitorLocker nu(Threads_lock); 879 while (Threads::number_of_non_daemon_threads() > expected) 880 // This wait should make safepoint checks, wait without a timeout. 881 nu.wait(0); 882 } 883 884 EventShutdown e; 885 if (e.should_commit()) { 886 e.set_reason("No remaining non-daemon Java threads"); 887 e.commit(); 888 } 889 890 // Hang forever on exit if we are reporting an error. 891 if (ShowMessageBoxOnError && VMError::is_error_reported()) { 892 os::infinite_sleep(); 893 } 894 os::wait_for_keypress_at_exit(); 895 896 // run Java level shutdown hooks 897 thread->invoke_shutdown_hooks(); 898 899 before_exit(thread); 900 901 thread->exit(true); 902 903 // We are no longer on the main thread list but could still be in a 904 // secondary list where another thread may try to interact with us. 905 // So wait until all such interactions are complete before we bring 906 // the VM to the termination safepoint. Normally this would be done 907 // using thread->smr_delete() below where we delete the thread, but 908 // we can't call that after the termination safepoint is active as 909 // we will deadlock on the Threads_lock. Once all interactions are 910 // complete it is safe to directly delete the thread at any time. 911 ThreadsSMRSupport::wait_until_not_protected(thread); 912 913 // Stop VM thread. 914 { 915 // 4945125 The vm thread comes to a safepoint during exit. 916 // GC vm_operations can get caught at the safepoint, and the 917 // heap is unparseable if they are caught. Grab the Heap_lock 918 // to prevent this. The GC vm_operations will not be able to 919 // queue until after the vm thread is dead. After this point, 920 // we'll never emerge out of the safepoint before the VM exits. 921 // Assert that the thread is terminated so that acquiring the 922 // Heap_lock doesn't cause the terminated thread to participate in 923 // the safepoint protocol. 924 925 assert(thread->is_terminated(), "must be terminated here"); 926 MutexLocker ml(Heap_lock); 927 928 VMThread::wait_for_vm_thread_exit(); 929 assert(SafepointSynchronize::is_at_safepoint(), "VM thread should exit at Safepoint"); 930 VMThread::destroy(); 931 } 932 933 // Now, all Java threads are gone except daemon threads. Daemon threads 934 // running Java code or in VM are stopped by the Safepoint. However, 935 // daemon threads executing native code are still running. But they 936 // will be stopped at native=>Java/VM barriers. Note that we can't 937 // simply kill or suspend them, as it is inherently deadlock-prone. 938 939 VM_Exit::set_vm_exited(); 940 941 // Clean up ideal graph printers after the VMThread has started 942 // the final safepoint which will block all the Compiler threads. 943 // Note that this Thread has already logically exited so the 944 // clean_up() function's use of a JavaThreadIteratorWithHandle 945 // would be a problem except set_vm_exited() has remembered the 946 // shutdown thread which is granted a policy exception. 947 #if defined(COMPILER2) && !defined(PRODUCT) 948 IdealGraphPrinter::clean_up(); 949 #endif 950 951 notify_vm_shutdown(); 952 953 // exit_globals() will delete tty 954 exit_globals(); 955 956 // Deleting the shutdown thread here is safe. See comment on 957 // wait_until_not_protected() above. 958 delete thread; 959 960 #if INCLUDE_JVMCI 961 if (JVMCICounterSize > 0) { 962 FREE_C_HEAP_ARRAY(jlong, JavaThread::_jvmci_old_thread_counters); 963 } 964 #endif 965 966 LogConfiguration::finalize(); 967 } 968 969 970 jboolean Threads::is_supported_jni_version_including_1_1(jint version) { 971 if (version == JNI_VERSION_1_1) return JNI_TRUE; 972 return is_supported_jni_version(version); 973 } 974 975 976 jboolean Threads::is_supported_jni_version(jint version) { 977 if (version == JNI_VERSION_1_2) return JNI_TRUE; 978 if (version == JNI_VERSION_1_4) return JNI_TRUE; 979 if (version == JNI_VERSION_1_6) return JNI_TRUE; 980 if (version == JNI_VERSION_1_8) return JNI_TRUE; 981 if (version == JNI_VERSION_9) return JNI_TRUE; 982 if (version == JNI_VERSION_10) return JNI_TRUE; 983 if (version == JNI_VERSION_19) return JNI_TRUE; 984 if (version == JNI_VERSION_20) return JNI_TRUE; 985 if (version == JNI_VERSION_21) return JNI_TRUE; 986 return JNI_FALSE; 987 } 988 989 void Threads::add(JavaThread* p, bool force_daemon) { 990 // The threads lock must be owned at this point 991 assert(Threads_lock->owned_by_self(), "must have threads lock"); 992 993 BarrierSet::barrier_set()->on_thread_attach(p); 994 995 // Once a JavaThread is added to the Threads list, smr_delete() has 996 // to be used to delete it. Otherwise we can just delete it directly. 997 p->set_on_thread_list(); 998 999 _number_of_threads++; 1000 oop threadObj = p->threadObj(); 1001 bool daemon = true; 1002 // Bootstrapping problem: threadObj can be null for initial 1003 // JavaThread (or for threads attached via JNI) 1004 if (!force_daemon && 1005 (threadObj == nullptr || !java_lang_Thread::is_daemon(threadObj))) { 1006 _number_of_non_daemon_threads++; 1007 daemon = false; 1008 } 1009 1010 ThreadService::add_thread(p, daemon); 1011 1012 // Maintain fast thread list 1013 ThreadsSMRSupport::add_thread(p); 1014 1015 // Increase the ObjectMonitor ceiling for the new thread. 1016 ObjectSynchronizer::inc_in_use_list_ceiling(); 1017 1018 // Possible GC point. 1019 Events::log(p, "Thread added: " INTPTR_FORMAT, p2i(p)); 1020 1021 // Make new thread known to active EscapeBarrier 1022 EscapeBarrier::thread_added(p); 1023 } 1024 1025 void Threads::remove(JavaThread* p, bool is_daemon) { 1026 // Extra scope needed for Thread_lock, so we can check 1027 // that we do not remove thread without safepoint code notice 1028 { MonitorLocker ml(Threads_lock); 1029 1030 if (ThreadIdTable::is_initialized()) { 1031 // This cleanup must be done before the current thread's GC barrier 1032 // is detached since we need to touch the threadObj oop. 1033 jlong tid = SharedRuntime::get_java_tid(p); 1034 ThreadIdTable::remove_thread(tid); 1035 } 1036 1037 // BarrierSet state must be destroyed after the last thread transition 1038 // before the thread terminates. Thread transitions result in calls to 1039 // StackWatermarkSet::on_safepoint(), which performs GC processing, 1040 // requiring the GC state to be alive. 1041 BarrierSet::barrier_set()->on_thread_detach(p); 1042 if (p->is_exiting()) { 1043 // If we got here via JavaThread::exit(), then we remember that the 1044 // thread's GC barrier has been detached. We don't do this when we get 1045 // here from another path, e.g., cleanup_failed_attach_current_thread(). 1046 p->set_terminated(JavaThread::_thread_gc_barrier_detached); 1047 } 1048 1049 assert(ThreadsSMRSupport::get_java_thread_list()->includes(p), "p must be present"); 1050 1051 // Maintain fast thread list 1052 ThreadsSMRSupport::remove_thread(p); 1053 1054 _number_of_threads--; 1055 if (!is_daemon) { 1056 _number_of_non_daemon_threads--; 1057 1058 // If this is the last non-daemon thread then we need to do 1059 // a notify on the Threads_lock so a thread waiting 1060 // on destroy_vm will wake up. But that thread could be a daemon 1061 // or non-daemon, so we notify for both the 0 and 1 case. 1062 if (number_of_non_daemon_threads() <= 1) { 1063 ml.notify_all(); 1064 } 1065 } 1066 ThreadService::remove_thread(p, is_daemon); 1067 1068 // Make sure that safepoint code disregard this thread. This is needed since 1069 // the thread might mess around with locks after this point. This can cause it 1070 // to do callbacks into the safepoint code. However, the safepoint code is not aware 1071 // of this thread since it is removed from the queue. 1072 p->set_terminated(JavaThread::_thread_terminated); 1073 1074 // Notify threads waiting in EscapeBarriers 1075 EscapeBarrier::thread_removed(p); 1076 } // unlock Threads_lock 1077 1078 // Reduce the ObjectMonitor ceiling for the exiting thread. 1079 ObjectSynchronizer::dec_in_use_list_ceiling(); 1080 1081 // Since Events::log uses a lock, we grab it outside the Threads_lock 1082 Events::log(p, "Thread exited: " INTPTR_FORMAT, p2i(p)); 1083 } 1084 1085 // Operations on the Threads list for GC. These are not explicitly locked, 1086 // but the garbage collector must provide a safe context for them to run. 1087 // In particular, these things should never be called when the Threads_lock 1088 // is held by some other thread. (Note: the Safepoint abstraction also 1089 // uses the Threads_lock to guarantee this property. It also makes sure that 1090 // all threads gets blocked when exiting or starting). 1091 1092 void Threads::oops_do(OopClosure* f, CodeBlobClosure* cf) { 1093 ALL_JAVA_THREADS(p) { 1094 p->oops_do(f, cf); 1095 } 1096 VMThread::vm_thread()->oops_do(f, cf); 1097 } 1098 1099 void Threads::change_thread_claim_token() { 1100 if (++_thread_claim_token == 0) { 1101 // On overflow of the token counter, there is a risk of future 1102 // collisions between a new global token value and a stale token 1103 // for a thread, because not all iterations visit all threads. 1104 // (Though it's pretty much a theoretical concern for non-trivial 1105 // token counter sizes.) To deal with the possibility, reset all 1106 // the thread tokens to zero on global token overflow. 1107 struct ResetClaims : public ThreadClosure { 1108 virtual void do_thread(Thread* t) { 1109 t->claim_threads_do(false, 0); 1110 } 1111 } reset_claims; 1112 Threads::threads_do(&reset_claims); 1113 // On overflow, update the global token to non-zero, to 1114 // avoid the special "never claimed" initial thread value. 1115 _thread_claim_token = 1; 1116 } 1117 } 1118 1119 #ifdef ASSERT 1120 void assert_thread_claimed(const char* kind, Thread* t, uintx expected) { 1121 const uintx token = t->threads_do_token(); 1122 assert(token == expected, 1123 "%s " PTR_FORMAT " has incorrect value " UINTX_FORMAT " != " 1124 UINTX_FORMAT, kind, p2i(t), token, expected); 1125 } 1126 1127 void Threads::assert_all_threads_claimed() { 1128 ALL_JAVA_THREADS(p) { 1129 assert_thread_claimed("JavaThread", p, _thread_claim_token); 1130 } 1131 1132 struct NJTClaimedVerifierClosure : public ThreadClosure { 1133 uintx _thread_claim_token; 1134 1135 NJTClaimedVerifierClosure(uintx thread_claim_token) : ThreadClosure(), _thread_claim_token(thread_claim_token) { } 1136 1137 virtual void do_thread(Thread* thread) override { 1138 assert_thread_claimed("Non-JavaThread", VMThread::vm_thread(), _thread_claim_token); 1139 } 1140 } tc(_thread_claim_token); 1141 1142 non_java_threads_do(&tc); 1143 } 1144 #endif // ASSERT 1145 1146 class ParallelOopsDoThreadClosure : public ThreadClosure { 1147 private: 1148 OopClosure* _f; 1149 CodeBlobClosure* _cf; 1150 public: 1151 ParallelOopsDoThreadClosure(OopClosure* f, CodeBlobClosure* cf) : _f(f), _cf(cf) {} 1152 void do_thread(Thread* t) { 1153 t->oops_do(_f, _cf); 1154 } 1155 }; 1156 1157 void Threads::possibly_parallel_oops_do(bool is_par, OopClosure* f, CodeBlobClosure* cf) { 1158 ParallelOopsDoThreadClosure tc(f, cf); 1159 possibly_parallel_threads_do(is_par, &tc); 1160 } 1161 1162 void Threads::metadata_do(MetadataClosure* f) { 1163 ALL_JAVA_THREADS(p) { 1164 p->metadata_do(f); 1165 } 1166 } 1167 1168 class ThreadHandlesClosure : public ThreadClosure { 1169 void (*_f)(Metadata*); 1170 public: 1171 ThreadHandlesClosure(void f(Metadata*)) : _f(f) {} 1172 virtual void do_thread(Thread* thread) { 1173 thread->metadata_handles_do(_f); 1174 } 1175 }; 1176 1177 void Threads::metadata_handles_do(void f(Metadata*)) { 1178 // Only walk the Handles in Thread. 1179 ThreadHandlesClosure handles_closure(f); 1180 threads_do(&handles_closure); 1181 } 1182 1183 // Get count Java threads that are waiting to enter the specified monitor. 1184 GrowableArray<JavaThread*>* Threads::get_pending_threads(ThreadsList * t_list, 1185 int count, 1186 address monitor) { 1187 GrowableArray<JavaThread*>* result = new GrowableArray<JavaThread*>(count); 1188 1189 int i = 0; 1190 for (JavaThread* p : *t_list) { 1191 if (!p->can_call_java()) continue; 1192 1193 // The first stage of async deflation does not affect any field 1194 // used by this comparison so the ObjectMonitor* is usable here. 1195 address pending = (address)p->current_pending_monitor(); 1196 if (pending == monitor) { // found a match 1197 if (i < count) result->append(p); // save the first count matches 1198 i++; 1199 } 1200 } 1201 1202 return result; 1203 } 1204 1205 1206 JavaThread *Threads::owning_thread_from_monitor_owner(ThreadsList * t_list, 1207 address owner) { 1208 assert(LockingMode != LM_LIGHTWEIGHT, "Not with new lightweight locking"); 1209 // null owner means not locked so we can skip the search 1210 if (owner == nullptr) return nullptr; 1211 1212 for (JavaThread* p : *t_list) { 1213 // first, see if owner is the address of a Java thread 1214 if (owner == (address)p) return p; 1215 } 1216 1217 // Cannot assert on lack of success here since this function may be 1218 // used by code that is trying to report useful problem information 1219 // like deadlock detection. 1220 if (LockingMode == LM_MONITOR) return nullptr; 1221 1222 // If we didn't find a matching Java thread and we didn't force use of 1223 // heavyweight monitors, then the owner is the stack address of the 1224 // Lock Word in the owning Java thread's stack. 1225 // 1226 JavaThread* the_owner = nullptr; 1227 for (JavaThread* q : *t_list) { 1228 if (q->is_lock_owned(owner)) { 1229 the_owner = q; 1230 break; 1231 } 1232 } 1233 1234 // cannot assert on lack of success here; see above comment 1235 return the_owner; 1236 } 1237 1238 JavaThread* Threads::owning_thread_from_object(ThreadsList * t_list, oop obj) { 1239 assert(LockingMode == LM_LIGHTWEIGHT, "Only with new lightweight locking"); 1240 for (JavaThread* q : *t_list) { 1241 if (q->lock_stack().contains(obj)) { 1242 return q; 1243 } 1244 } 1245 return nullptr; 1246 } 1247 1248 JavaThread* Threads::owning_thread_from_monitor(ThreadsList* t_list, ObjectMonitor* monitor) { 1249 if (LockingMode == LM_LIGHTWEIGHT) { 1250 if (monitor->is_owner_anonymous()) { 1251 return owning_thread_from_object(t_list, monitor->object()); 1252 } else { 1253 Thread* owner = reinterpret_cast<Thread*>(monitor->owner()); 1254 assert(owner == nullptr || owner->is_Java_thread(), "only JavaThreads own monitors"); 1255 return reinterpret_cast<JavaThread*>(owner); 1256 } 1257 } else { 1258 address owner = (address)monitor->owner(); 1259 return owning_thread_from_monitor_owner(t_list, owner); 1260 } 1261 } 1262 1263 class PrintOnClosure : public ThreadClosure { 1264 private: 1265 outputStream* _st; 1266 1267 public: 1268 PrintOnClosure(outputStream* st) : 1269 _st(st) {} 1270 1271 virtual void do_thread(Thread* thread) { 1272 if (thread != nullptr) { 1273 thread->print_on(_st); 1274 _st->cr(); 1275 } 1276 } 1277 }; 1278 1279 // Threads::print_on() is called at safepoint by VM_PrintThreads operation. 1280 void Threads::print_on(outputStream* st, bool print_stacks, 1281 bool internal_format, bool print_concurrent_locks, 1282 bool print_extended_info) { 1283 char buf[32]; 1284 st->print_raw_cr(os::local_time_string(buf, sizeof(buf))); 1285 1286 st->print_cr("Full thread dump %s (%s %s):", 1287 VM_Version::vm_name(), 1288 VM_Version::vm_release(), 1289 VM_Version::vm_info_string()); 1290 st->cr(); 1291 1292 #if INCLUDE_SERVICES 1293 // Dump concurrent locks 1294 ConcurrentLocksDump concurrent_locks; 1295 if (print_concurrent_locks) { 1296 concurrent_locks.dump_at_safepoint(); 1297 } 1298 #endif // INCLUDE_SERVICES 1299 1300 ThreadsSMRSupport::print_info_on(st); 1301 st->cr(); 1302 1303 ALL_JAVA_THREADS(p) { 1304 ResourceMark rm; 1305 p->print_on(st, print_extended_info); 1306 if (print_stacks) { 1307 if (internal_format) { 1308 p->trace_stack(); 1309 } else { 1310 p->print_stack_on(st); 1311 } 1312 } 1313 st->cr(); 1314 #if INCLUDE_SERVICES 1315 if (print_concurrent_locks) { 1316 concurrent_locks.print_locks_on(p, st); 1317 } 1318 #endif // INCLUDE_SERVICES 1319 } 1320 1321 PrintOnClosure cl(st); 1322 cl.do_thread(VMThread::vm_thread()); 1323 Universe::heap()->gc_threads_do(&cl); 1324 cl.do_thread(WatcherThread::watcher_thread()); 1325 cl.do_thread(AsyncLogWriter::instance()); 1326 1327 st->flush(); 1328 } 1329 1330 void Threads::print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf, 1331 int buflen, bool* found_current) { 1332 if (this_thread != nullptr) { 1333 bool is_current = (current == this_thread); 1334 *found_current = *found_current || is_current; 1335 st->print("%s", is_current ? "=>" : " "); 1336 1337 st->print(PTR_FORMAT, p2i(this_thread)); 1338 st->print(" "); 1339 this_thread->print_on_error(st, buf, buflen); 1340 st->cr(); 1341 } 1342 } 1343 1344 class PrintOnErrorClosure : public ThreadClosure { 1345 outputStream* _st; 1346 Thread* _current; 1347 char* _buf; 1348 int _buflen; 1349 bool* _found_current; 1350 unsigned _num_printed; 1351 public: 1352 PrintOnErrorClosure(outputStream* st, Thread* current, char* buf, 1353 int buflen, bool* found_current) : 1354 _st(st), _current(current), _buf(buf), _buflen(buflen), _found_current(found_current), 1355 _num_printed(0) {} 1356 1357 virtual void do_thread(Thread* thread) { 1358 _num_printed++; 1359 Threads::print_on_error(thread, _st, _current, _buf, _buflen, _found_current); 1360 } 1361 1362 unsigned num_printed() const { return _num_printed; } 1363 }; 1364 1365 // Threads::print_on_error() is called by fatal error handler. It's possible 1366 // that VM is not at safepoint and/or current thread is inside signal handler. 1367 // Don't print stack trace, as the stack may not be walkable. Don't allocate 1368 // memory (even in resource area), it might deadlock the error handler. 1369 void Threads::print_on_error(outputStream* st, Thread* current, char* buf, 1370 int buflen) { 1371 ThreadsSMRSupport::print_info_on(st); 1372 st->cr(); 1373 1374 bool found_current = false; 1375 st->print_cr("Java Threads: ( => current thread )"); 1376 unsigned num_java = 0; 1377 ALL_JAVA_THREADS(thread) { 1378 print_on_error(thread, st, current, buf, buflen, &found_current); 1379 num_java++; 1380 } 1381 st->print_cr("Total: %u", num_java); 1382 st->cr(); 1383 1384 st->print_cr("Other Threads:"); 1385 unsigned num_other = ((VMThread::vm_thread() != nullptr) ? 1 : 0) + 1386 ((WatcherThread::watcher_thread() != nullptr) ? 1 : 0) + 1387 ((AsyncLogWriter::instance() != nullptr) ? 1 : 0); 1388 print_on_error(VMThread::vm_thread(), st, current, buf, buflen, &found_current); 1389 print_on_error(WatcherThread::watcher_thread(), st, current, buf, buflen, &found_current); 1390 print_on_error(AsyncLogWriter::instance(), st, current, buf, buflen, &found_current); 1391 1392 if (Universe::heap() != nullptr) { 1393 PrintOnErrorClosure print_closure(st, current, buf, buflen, &found_current); 1394 Universe::heap()->gc_threads_do(&print_closure); 1395 num_other += print_closure.num_printed(); 1396 } 1397 1398 if (!found_current) { 1399 st->cr(); 1400 st->print("=>" PTR_FORMAT " (exited) ", p2i(current)); 1401 current->print_on_error(st, buf, buflen); 1402 num_other++; 1403 st->cr(); 1404 } 1405 st->print_cr("Total: %u", num_other); 1406 st->cr(); 1407 1408 st->print_cr("Threads with active compile tasks:"); 1409 unsigned num = print_threads_compiling(st, buf, buflen); 1410 st->print_cr("Total: %u", num); 1411 } 1412 1413 unsigned Threads::print_threads_compiling(outputStream* st, char* buf, int buflen, bool short_form) { 1414 unsigned num = 0; 1415 ALL_JAVA_THREADS(thread) { 1416 if (thread->is_Compiler_thread()) { 1417 CompilerThread* ct = (CompilerThread*) thread; 1418 1419 // Keep task in local variable for null check. 1420 // ct->_task might be set to null by concurring compiler thread 1421 // because it completed the compilation. The task is never freed, 1422 // though, just returned to a free list. 1423 CompileTask* task = ct->task(); 1424 if (task != nullptr) { 1425 thread->print_name_on_error(st, buf, buflen); 1426 st->print(" "); 1427 task->print(st, nullptr, short_form, true); 1428 num++; 1429 } 1430 } 1431 } 1432 return num; 1433 } 1434 1435 void Threads::verify() { 1436 ALL_JAVA_THREADS(p) { 1437 p->verify(); 1438 } 1439 VMThread* thread = VMThread::vm_thread(); 1440 if (thread != nullptr) thread->verify(); 1441 }