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/jvm_misc.hpp" 60 #include "runtime/arguments.hpp" 61 #include "runtime/fieldDescriptor.inline.hpp" 62 #include "runtime/flags/jvmFlagLimit.hpp" 63 #include "runtime/handles.inline.hpp" 64 #include "runtime/globals.hpp" 65 #include "runtime/interfaceSupport.inline.hpp" 66 #include "runtime/java.hpp" 67 #include "runtime/javaCalls.hpp" 68 #include "runtime/javaThread.inline.hpp" 69 #include "runtime/jniHandles.inline.hpp" 70 #include "runtime/jniPeriodicChecker.hpp" 71 #include "runtime/lockStack.inline.hpp" 72 #include "runtime/monitorDeflationThread.hpp" 73 #include "runtime/mutexLocker.hpp" 74 #include "runtime/nonJavaThread.hpp" 75 #include "runtime/objectMonitor.inline.hpp" 76 #include "runtime/osThread.hpp" 77 #include "runtime/safepoint.hpp" 78 #include "runtime/safepointMechanism.inline.hpp" 79 #include "runtime/safepointVerifiers.hpp" 80 #include "runtime/serviceThread.hpp" 81 #include "runtime/sharedRuntime.hpp" 82 #include "runtime/statSampler.hpp" 83 #include "runtime/stubCodeGenerator.hpp" 84 #include "runtime/thread.inline.hpp" 85 #include "runtime/threads.hpp" 86 #include "runtime/threadSMR.inline.hpp" 87 #include "runtime/timer.hpp" 88 #include "runtime/timerTrace.hpp" 89 #include "runtime/vmOperations.hpp" 90 #include "runtime/vm_version.hpp" 91 #include "services/attachListener.hpp" 92 #include "services/management.hpp" 93 #include "services/memTracker.hpp" 94 #include "services/threadIdTable.hpp" 95 #include "services/threadService.hpp" 96 #include "utilities/dtrace.hpp" 97 #include "utilities/events.hpp" 98 #include "utilities/macros.hpp" 99 #include "utilities/systemMemoryBarrier.hpp" 100 #include "utilities/vmError.hpp" 101 #if INCLUDE_JVMCI 102 #include "jvmci/jvmci.hpp" 103 #include "jvmci/jvmciEnv.hpp" 104 #endif 105 #ifdef COMPILER2 106 #include "opto/idealGraphPrinter.hpp" 107 #endif 108 #if INCLUDE_RTM_OPT 109 #include "runtime/rtmLocking.hpp" 110 #endif 111 #if INCLUDE_JFR 112 #include "jfr/jfr.hpp" 113 #endif 114 115 // Initialization after module runtime initialization 116 void universe_post_module_init(); // must happen after call_initPhase2 117 118 119 static void initialize_class(Symbol* class_name, TRAPS) { 120 Klass* klass = SystemDictionary::resolve_or_fail(class_name, true, CHECK); 121 InstanceKlass::cast(klass)->initialize(CHECK); 122 } 123 124 125 // Creates the initial ThreadGroup 126 static Handle create_initial_thread_group(TRAPS) { 127 Handle system_instance = JavaCalls::construct_new_instance( 128 vmClasses::ThreadGroup_klass(), 129 vmSymbols::void_method_signature(), 130 CHECK_NH); 131 Universe::set_system_thread_group(system_instance()); 132 133 Handle string = java_lang_String::create_from_str("main", CHECK_NH); 134 Handle main_instance = JavaCalls::construct_new_instance( 135 vmClasses::ThreadGroup_klass(), 136 vmSymbols::threadgroup_string_void_signature(), 137 system_instance, 138 string, 139 CHECK_NH); 140 return main_instance; 141 } 142 143 // Creates the initial Thread, and sets it to running. 144 static void create_initial_thread(Handle thread_group, JavaThread* thread, 145 TRAPS) { 146 InstanceKlass* ik = vmClasses::Thread_klass(); 147 assert(ik->is_initialized(), "must be"); 148 instanceHandle thread_oop = ik->allocate_instance_handle(CHECK); 149 150 // Cannot use JavaCalls::construct_new_instance because the java.lang.Thread 151 // constructor calls Thread.current(), which must be set here for the 152 // initial thread. 153 java_lang_Thread::set_thread(thread_oop(), thread); 154 thread->set_threadOopHandles(thread_oop()); 155 156 Handle string = java_lang_String::create_from_str("main", CHECK); 157 158 JavaValue result(T_VOID); 159 JavaCalls::call_special(&result, thread_oop, 160 ik, 161 vmSymbols::object_initializer_name(), 162 vmSymbols::threadgroup_string_void_signature(), 163 thread_group, 164 string, 165 CHECK); 166 167 // Set thread status to running since main thread has 168 // been started and running. 169 java_lang_Thread::set_thread_status(thread_oop(), 170 JavaThreadStatus::RUNNABLE); 171 } 172 173 // Extract version and vendor specific information from 174 // java.lang.VersionProps fields. 175 // Returned char* is allocated in the thread's resource area 176 // so must be copied for permanency. 177 static const char* get_java_version_info(InstanceKlass* ik, 178 Symbol* field_name) { 179 fieldDescriptor fd; 180 bool found = ik != nullptr && 181 ik->find_local_field(field_name, 182 vmSymbols::string_signature(), &fd); 183 if (found) { 184 oop name_oop = ik->java_mirror()->obj_field(fd.offset()); 185 if (name_oop == nullptr) { 186 return nullptr; 187 } 188 const char* name = java_lang_String::as_utf8_string(name_oop); 189 return name; 190 } else { 191 return nullptr; 192 } 193 } 194 195 // ======= Threads ======== 196 197 // The Threads class links together all active threads, and provides 198 // operations over all threads. It is protected by the Threads_lock, 199 // which is also used in other global contexts like safepointing. 200 // ThreadsListHandles are used to safely perform operations on one 201 // or more threads without the risk of the thread exiting during the 202 // operation. 203 // 204 // Note: The Threads_lock is currently more widely used than we 205 // would like. We are actively migrating Threads_lock uses to other 206 // mechanisms in order to reduce Threads_lock contention. 207 208 int Threads::_number_of_threads = 0; 209 int Threads::_number_of_non_daemon_threads = 0; 210 int Threads::_return_code = 0; 211 uintx Threads::_thread_claim_token = 1; // Never zero. 212 213 #ifdef ASSERT 214 bool Threads::_vm_complete = false; 215 #endif 216 217 // General purpose hook into Java code, run once when the VM is initialized. 218 // The Java library method itself may be changed independently from the VM. 219 static void call_postVMInitHook(TRAPS) { 220 Klass* klass = SystemDictionary::resolve_or_null(vmSymbols::jdk_internal_vm_PostVMInitHook(), THREAD); 221 if (klass != nullptr) { 222 JavaValue result(T_VOID); 223 JavaCalls::call_static(&result, klass, vmSymbols::run_method_name(), 224 vmSymbols::void_method_signature(), 225 CHECK); 226 } 227 } 228 229 // All NonJavaThreads (i.e., every non-JavaThread in the system). 230 void Threads::non_java_threads_do(ThreadClosure* tc) { 231 NoSafepointVerifier nsv; 232 for (NonJavaThread::Iterator njti; !njti.end(); njti.step()) { 233 tc->do_thread(njti.current()); 234 } 235 } 236 237 // All JavaThreads 238 #define ALL_JAVA_THREADS(X) \ 239 for (JavaThread* X : *ThreadsSMRSupport::get_java_thread_list()) 240 241 // All JavaThreads 242 void Threads::java_threads_do(ThreadClosure* tc) { 243 assert_locked_or_safepoint(Threads_lock); 244 // ALL_JAVA_THREADS iterates through all JavaThreads. 245 ALL_JAVA_THREADS(p) { 246 tc->do_thread(p); 247 } 248 } 249 250 // All JavaThreads + all non-JavaThreads (i.e., every thread in the system). 251 void Threads::threads_do(ThreadClosure* tc) { 252 assert_locked_or_safepoint(Threads_lock); 253 java_threads_do(tc); 254 non_java_threads_do(tc); 255 } 256 257 void Threads::possibly_parallel_threads_do(bool is_par, ThreadClosure* tc) { 258 assert_at_safepoint(); 259 260 uintx claim_token = Threads::thread_claim_token(); 261 ALL_JAVA_THREADS(p) { 262 if (p->claim_threads_do(is_par, claim_token)) { 263 tc->do_thread(p); 264 } 265 } 266 for (NonJavaThread::Iterator njti; !njti.end(); njti.step()) { 267 Thread* current = njti.current(); 268 if (current->claim_threads_do(is_par, claim_token)) { 269 tc->do_thread(current); 270 } 271 } 272 } 273 274 // The system initialization in the library has three phases. 275 // 276 // Phase 1: java.lang.System class initialization 277 // java.lang.System is a primordial class loaded and initialized 278 // by the VM early during startup. java.lang.System.<clinit> 279 // only does registerNatives and keeps the rest of the class 280 // initialization work later until thread initialization completes. 281 // 282 // System.initPhase1 initializes the system properties, the static 283 // fields in, out, and err. Set up java signal handlers, OS-specific 284 // system settings, and thread group of the main thread. 285 static void call_initPhase1(TRAPS) { 286 Klass* klass = vmClasses::System_klass(); 287 JavaValue result(T_VOID); 288 JavaCalls::call_static(&result, klass, vmSymbols::initPhase1_name(), 289 vmSymbols::void_method_signature(), CHECK); 290 } 291 292 // Phase 2. Module system initialization 293 // This will initialize the module system. Only java.base classes 294 // can be loaded until phase 2 completes. 295 // 296 // Call System.initPhase2 after the compiler initialization and jsr292 297 // classes get initialized because module initialization runs a lot of java 298 // code, that for performance reasons, should be compiled. Also, this will 299 // enable the startup code to use lambda and other language features in this 300 // phase and onward. 301 // 302 // After phase 2, The VM will begin search classes from -Xbootclasspath/a. 303 static void call_initPhase2(TRAPS) { 304 TraceTime timer("Initialize module system", TRACETIME_LOG(Info, startuptime)); 305 306 Klass* klass = vmClasses::System_klass(); 307 308 JavaValue result(T_INT); 309 JavaCallArguments args; 310 args.push_int(DisplayVMOutputToStderr); 311 args.push_int(log_is_enabled(Debug, init)); // print stack trace if exception thrown 312 JavaCalls::call_static(&result, klass, vmSymbols::initPhase2_name(), 313 vmSymbols::boolean_boolean_int_signature(), &args, CHECK); 314 if (result.get_jint() != JNI_OK) { 315 vm_exit_during_initialization(); // no message or exception 316 } 317 318 universe_post_module_init(); 319 } 320 321 // Phase 3. final setup - set security manager, system class loader and TCCL 322 // 323 // This will instantiate and set the security manager, set the system class 324 // loader as well as the thread context class loader. The security manager 325 // and system class loader may be a custom class loaded from -Xbootclasspath/a, 326 // other modules or the application's classpath. 327 static void call_initPhase3(TRAPS) { 328 Klass* klass = vmClasses::System_klass(); 329 JavaValue result(T_VOID); 330 JavaCalls::call_static(&result, klass, vmSymbols::initPhase3_name(), 331 vmSymbols::void_method_signature(), CHECK); 332 } 333 334 void Threads::initialize_java_lang_classes(JavaThread* main_thread, TRAPS) { 335 TraceTime timer("Initialize java.lang classes", TRACETIME_LOG(Info, startuptime)); 336 337 if (EagerXrunInit && Arguments::init_libraries_at_startup()) { 338 create_vm_init_libraries(); 339 } 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 // Convert -Xrun to -agentlib: if there is no JVM_OnLoad 505 // Must be before create_vm_init_agents() 506 if (Arguments::init_libraries_at_startup()) { 507 convert_vm_init_libraries_to_agents(); 508 } 509 510 // Launch -agentlib/-agentpath and converted -Xrun agents 511 if (Arguments::init_agents_at_startup()) { 512 create_vm_init_agents(); 513 } 514 515 // Initialize Threads state 516 _number_of_threads = 0; 517 _number_of_non_daemon_threads = 0; 518 519 // Initialize global data structures and create system classes in heap 520 vm_init_globals(); 521 522 #if INCLUDE_JVMCI 523 if (JVMCICounterSize > 0) { 524 JavaThread::_jvmci_old_thread_counters = NEW_C_HEAP_ARRAY(jlong, JVMCICounterSize, mtJVMCI); 525 memset(JavaThread::_jvmci_old_thread_counters, 0, sizeof(jlong) * JVMCICounterSize); 526 } else { 527 JavaThread::_jvmci_old_thread_counters = nullptr; 528 } 529 #endif // INCLUDE_JVMCI 530 531 // Initialize OopStorage for threadObj 532 JavaThread::_thread_oop_storage = OopStorageSet::create_strong("Thread OopStorage", mtThread); 533 534 // Attach the main thread to this os thread 535 JavaThread* main_thread = new JavaThread(); 536 main_thread->set_thread_state(_thread_in_vm); 537 main_thread->initialize_thread_current(); 538 // must do this before set_active_handles 539 main_thread->record_stack_base_and_size(); 540 main_thread->register_thread_stack_with_NMT(); 541 main_thread->set_active_handles(JNIHandleBlock::allocate_block()); 542 MACOS_AARCH64_ONLY(main_thread->init_wx()); 543 544 if (!main_thread->set_as_starting_thread()) { 545 vm_shutdown_during_initialization( 546 "Failed necessary internal allocation. Out of swap space"); 547 main_thread->smr_delete(); 548 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again 549 return JNI_ENOMEM; 550 } 551 552 // Enable guard page *after* os::create_main_thread(), otherwise it would 553 // crash Linux VM, see notes in os_linux.cpp. 554 main_thread->stack_overflow_state()->create_stack_guard_pages(); 555 556 if (UseSystemMemoryBarrier) { 557 if (!SystemMemoryBarrier::initialize()) { 558 vm_shutdown_during_initialization("Failed to initialize the requested system memory barrier synchronization."); 559 return JNI_EINVAL; 560 } 561 log_debug(os)("Using experimental system memory barrier synchronization"); 562 } 563 564 // Initialize Java-Level synchronization subsystem 565 ObjectMonitor::Initialize(); 566 ObjectSynchronizer::initialize(); 567 568 // Initialize global modules 569 jint status = init_globals(); 570 if (status != JNI_OK) { 571 main_thread->smr_delete(); 572 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again 573 return status; 574 } 575 576 JFR_ONLY(Jfr::on_create_vm_1();) 577 578 // Should be done after the heap is fully created 579 main_thread->cache_global_variables(); 580 581 { MutexLocker mu(Threads_lock); 582 Threads::add(main_thread); 583 } 584 585 // Any JVMTI raw monitors entered in onload will transition into 586 // real raw monitor. VM is setup enough here for raw monitor enter. 587 JvmtiExport::transition_pending_onload_raw_monitors(); 588 589 // Create the VMThread 590 { TraceTime timer("Start VMThread", TRACETIME_LOG(Info, startuptime)); 591 592 VMThread::create(); 593 VMThread* vmthread = VMThread::vm_thread(); 594 595 if (!os::create_thread(vmthread, os::vm_thread)) { 596 vm_exit_during_initialization("Cannot create VM thread. " 597 "Out of system resources."); 598 } 599 600 // Wait for the VM thread to become ready, and VMThread::run to initialize 601 // Monitors can have spurious returns, must always check another state flag 602 { 603 MonitorLocker ml(Notify_lock); 604 os::start_thread(vmthread); 605 while (!vmthread->is_running()) { 606 ml.wait(); 607 } 608 } 609 } 610 611 assert(Universe::is_fully_initialized(), "not initialized"); 612 if (VerifyDuringStartup) { 613 // Make sure we're starting with a clean slate. 614 VM_Verify verify_op; 615 VMThread::execute(&verify_op); 616 } 617 618 // We need this to update the java.vm.info property in case any flags used 619 // to initially define it have been changed. This is needed for both CDS 620 // since UseSharedSpaces may be changed after java.vm.info 621 // is initially computed. See Abstract_VM_Version::vm_info_string(). 622 // This update must happen before we initialize the java classes, but 623 // after any initialization logic that might modify the flags. 624 Arguments::update_vm_info_property(VM_Version::vm_info_string()); 625 626 JavaThread* THREAD = JavaThread::current(); // For exception macros. 627 HandleMark hm(THREAD); 628 629 // Always call even when there are not JVMTI environments yet, since environments 630 // may be attached late and JVMTI must track phases of VM execution 631 JvmtiExport::enter_early_start_phase(); 632 633 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents. 634 JvmtiExport::post_early_vm_start(); 635 636 initialize_java_lang_classes(main_thread, CHECK_JNI_ERR); 637 638 quicken_jni_functions(); 639 640 // No more stub generation allowed after that point. 641 StubCodeDesc::freeze(); 642 643 // Set flag that basic initialization has completed. Used by exceptions and various 644 // debug stuff, that does not work until all basic classes have been initialized. 645 set_init_completed(); 646 647 LogConfiguration::post_initialize(); 648 Metaspace::post_initialize(); 649 MutexLocker::post_initialize(); 650 651 HOTSPOT_VM_INIT_END(); 652 653 // record VM initialization completion time 654 #if INCLUDE_MANAGEMENT 655 Management::record_vm_init_completed(); 656 #endif // INCLUDE_MANAGEMENT 657 658 // Signal Dispatcher needs to be started before VMInit event is posted 659 os::initialize_jdk_signal_support(CHECK_JNI_ERR); 660 661 // Start Attach Listener if +StartAttachListener or it can't be started lazily 662 if (!DisableAttachMechanism) { 663 AttachListener::vm_start(); 664 if (StartAttachListener || AttachListener::init_at_startup()) { 665 AttachListener::init(); 666 } 667 } 668 669 // Launch -Xrun agents 670 // Must be done in the JVMTI live phase so that for backward compatibility the JDWP 671 // back-end can launch with -Xdebug -Xrunjdwp. 672 if (!EagerXrunInit && Arguments::init_libraries_at_startup()) { 673 create_vm_init_libraries(); 674 } 675 676 Chunk::start_chunk_pool_cleaner_task(); 677 678 // Start the service thread 679 // The service thread enqueues JVMTI deferred events and does various hashtable 680 // and other cleanups. Needs to start before the compilers start posting events. 681 ServiceThread::initialize(); 682 683 // Start the monitor deflation thread: 684 MonitorDeflationThread::initialize(); 685 686 // initialize compiler(s) 687 #if defined(COMPILER1) || COMPILER2_OR_JVMCI 688 #if INCLUDE_JVMCI 689 bool force_JVMCI_intialization = false; 690 if (EnableJVMCI) { 691 // Initialize JVMCI eagerly when it is explicitly requested. 692 // Or when JVMCILibDumpJNIConfig or JVMCIPrintProperties is enabled. 693 force_JVMCI_intialization = EagerJVMCI || JVMCIPrintProperties || JVMCILibDumpJNIConfig; 694 695 if (!force_JVMCI_intialization) { 696 // 8145270: Force initialization of JVMCI runtime otherwise requests for blocking 697 // compilations via JVMCI will not actually block until JVMCI is initialized. 698 force_JVMCI_intialization = UseJVMCICompiler && (!UseInterpreter || !BackgroundCompilation); 699 } 700 } 701 #endif 702 CompileBroker::compilation_init_phase1(CHECK_JNI_ERR); 703 // Postpone completion of compiler initialization to after JVMCI 704 // is initialized to avoid timeouts of blocking compilations. 705 if (JVMCI_ONLY(!force_JVMCI_intialization) NOT_JVMCI(true)) { 706 CompileBroker::compilation_init_phase2(); 707 } 708 #endif 709 710 // Pre-initialize some JSR292 core classes to avoid deadlock during class loading. 711 // It is done after compilers are initialized, because otherwise compilations of 712 // signature polymorphic MH intrinsics can be missed 713 // (see SystemDictionary::find_method_handle_intrinsic). 714 initialize_jsr292_core_classes(CHECK_JNI_ERR); 715 716 // This will initialize the module system. Only java.base classes can be 717 // loaded until phase 2 completes 718 call_initPhase2(CHECK_JNI_ERR); 719 720 JFR_ONLY(Jfr::on_create_vm_2();) 721 722 // Always call even when there are not JVMTI environments yet, since environments 723 // may be attached late and JVMTI must track phases of VM execution 724 JvmtiExport::enter_start_phase(); 725 726 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents. 727 JvmtiExport::post_vm_start(); 728 729 // Final system initialization including security manager and system class loader 730 call_initPhase3(CHECK_JNI_ERR); 731 732 // cache the system and platform class loaders 733 SystemDictionary::compute_java_loaders(CHECK_JNI_ERR); 734 735 #if INCLUDE_CDS 736 // capture the module path info from the ModuleEntryTable 737 ClassLoader::initialize_module_path(THREAD); 738 if (HAS_PENDING_EXCEPTION) { 739 java_lang_Throwable::print(PENDING_EXCEPTION, tty); 740 vm_exit_during_initialization("ClassLoader::initialize_module_path() failed unexpectedly"); 741 } 742 #endif 743 744 #if INCLUDE_JVMCI 745 if (force_JVMCI_intialization) { 746 JVMCI::initialize_compiler(CHECK_JNI_ERR); 747 CompileBroker::compilation_init_phase2(); 748 } 749 #endif 750 751 // Always call even when there are not JVMTI environments yet, since environments 752 // may be attached late and JVMTI must track phases of VM execution 753 JvmtiExport::enter_live_phase(); 754 755 // Make perfmemory accessible 756 PerfMemory::set_accessible(true); 757 758 // Notify JVMTI agents that VM initialization is complete - nop if no agents. 759 JvmtiExport::post_vm_initialized(); 760 761 JFR_ONLY(Jfr::on_create_vm_3();) 762 763 #if INCLUDE_MANAGEMENT 764 Management::initialize(THREAD); 765 766 if (HAS_PENDING_EXCEPTION) { 767 // management agent fails to start possibly due to 768 // configuration problem and is responsible for printing 769 // stack trace if appropriate. Simply exit VM. 770 vm_exit(1); 771 } 772 #endif // INCLUDE_MANAGEMENT 773 774 StatSampler::engage(); 775 if (CheckJNICalls) JniPeriodicChecker::engage(); 776 777 #if INCLUDE_RTM_OPT 778 RTMLockingCounters::init(); 779 #endif 780 781 call_postVMInitHook(THREAD); 782 // The Java side of PostVMInitHook.run must deal with all 783 // exceptions and provide means of diagnosis. 784 if (HAS_PENDING_EXCEPTION) { 785 CLEAR_PENDING_EXCEPTION; 786 } 787 788 { 789 MutexLocker ml(PeriodicTask_lock); 790 // Make sure the WatcherThread can be started by WatcherThread::start() 791 // or by dynamic enrollment. 792 WatcherThread::make_startable(); 793 // Start up the WatcherThread if there are any periodic tasks 794 // NOTE: All PeriodicTasks should be registered by now. If they 795 // aren't, late joiners might appear to start slowly (we might 796 // take a while to process their first tick). 797 if (PeriodicTask::num_tasks() > 0) { 798 WatcherThread::start(); 799 } 800 } 801 802 create_vm_timer.end(); 803 #ifdef ASSERT 804 _vm_complete = true; 805 #endif 806 807 if (DumpSharedSpaces) { 808 MetaspaceShared::preload_and_dump(); 809 ShouldNotReachHere(); 810 } 811 812 return JNI_OK; 813 } 814 815 // type for the Agent_OnLoad and JVM_OnLoad entry points 816 extern "C" { 817 typedef jint (JNICALL *OnLoadEntry_t)(JavaVM *, char *, void *); 818 } 819 // Find a command line agent library and return its entry point for 820 // -agentlib: -agentpath: -Xrun 821 // num_symbol_entries must be passed-in since only the caller knows the number of symbols in the array. 822 static OnLoadEntry_t lookup_on_load(AgentLibrary* agent, 823 const char *on_load_symbols[], 824 size_t num_symbol_entries) { 825 OnLoadEntry_t on_load_entry = nullptr; 826 void *library = nullptr; 827 828 if (!agent->valid()) { 829 char buffer[JVM_MAXPATHLEN]; 830 char ebuf[1024] = ""; 831 const char *name = agent->name(); 832 const char *msg = "Could not find agent library "; 833 834 // First check to see if agent is statically linked into executable 835 if (os::find_builtin_agent(agent, on_load_symbols, num_symbol_entries)) { 836 library = agent->os_lib(); 837 } else if (agent->is_absolute_path()) { 838 library = os::dll_load(name, ebuf, sizeof ebuf); 839 if (library == nullptr) { 840 const char *sub_msg = " in absolute path, with error: "; 841 size_t len = strlen(msg) + strlen(name) + strlen(sub_msg) + strlen(ebuf) + 1; 842 char *buf = NEW_C_HEAP_ARRAY(char, len, mtThread); 843 jio_snprintf(buf, len, "%s%s%s%s", msg, name, sub_msg, ebuf); 844 // If we can't find the agent, exit. 845 vm_exit_during_initialization(buf, nullptr); 846 FREE_C_HEAP_ARRAY(char, buf); 847 } 848 } else { 849 // Try to load the agent from the standard dll directory 850 if (os::dll_locate_lib(buffer, sizeof(buffer), Arguments::get_dll_dir(), 851 name)) { 852 library = os::dll_load(buffer, ebuf, sizeof ebuf); 853 } 854 if (library == nullptr) { // Try the library path directory. 855 if (os::dll_build_name(buffer, sizeof(buffer), name)) { 856 library = os::dll_load(buffer, ebuf, sizeof ebuf); 857 } 858 if (library == nullptr) { 859 const char *sub_msg = " on the library path, with error: "; 860 const char *sub_msg2 = "\nModule java.instrument may be missing from runtime image."; 861 862 size_t len = strlen(msg) + strlen(name) + strlen(sub_msg) + 863 strlen(ebuf) + strlen(sub_msg2) + 1; 864 char *buf = NEW_C_HEAP_ARRAY(char, len, mtThread); 865 if (!agent->is_instrument_lib()) { 866 jio_snprintf(buf, len, "%s%s%s%s", msg, name, sub_msg, ebuf); 867 } else { 868 jio_snprintf(buf, len, "%s%s%s%s%s", msg, name, sub_msg, ebuf, sub_msg2); 869 } 870 // If we can't find the agent, exit. 871 vm_exit_during_initialization(buf, nullptr); 872 FREE_C_HEAP_ARRAY(char, buf); 873 } 874 } 875 } 876 agent->set_os_lib(library); 877 agent->set_valid(); 878 } 879 880 // Find the OnLoad function. 881 on_load_entry = 882 CAST_TO_FN_PTR(OnLoadEntry_t, os::find_agent_function(agent, 883 false, 884 on_load_symbols, 885 num_symbol_entries)); 886 return on_load_entry; 887 } 888 889 // Find the JVM_OnLoad entry point 890 static OnLoadEntry_t lookup_jvm_on_load(AgentLibrary* agent) { 891 const char *on_load_symbols[] = JVM_ONLOAD_SYMBOLS; 892 return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*)); 893 } 894 895 // Find the Agent_OnLoad entry point 896 static OnLoadEntry_t lookup_agent_on_load(AgentLibrary* agent) { 897 const char *on_load_symbols[] = AGENT_ONLOAD_SYMBOLS; 898 return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*)); 899 } 900 901 // For backwards compatibility with -Xrun 902 // Convert libraries with no JVM_OnLoad, but which have Agent_OnLoad to be 903 // treated like -agentpath: 904 // Must be called before agent libraries are created 905 void Threads::convert_vm_init_libraries_to_agents() { 906 AgentLibrary* agent; 907 AgentLibrary* next; 908 909 for (agent = Arguments::libraries(); agent != nullptr; agent = next) { 910 next = agent->next(); // cache the next agent now as this agent may get moved off this list 911 OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent); 912 913 // If there is an JVM_OnLoad function it will get called later, 914 // otherwise see if there is an Agent_OnLoad 915 if (on_load_entry == nullptr) { 916 on_load_entry = lookup_agent_on_load(agent); 917 if (on_load_entry != nullptr) { 918 // switch it to the agent list -- so that Agent_OnLoad will be called, 919 // JVM_OnLoad won't be attempted and Agent_OnUnload will 920 Arguments::convert_library_to_agent(agent); 921 } else { 922 vm_exit_during_initialization("Could not find JVM_OnLoad or Agent_OnLoad function in the library", agent->name()); 923 } 924 } 925 } 926 } 927 928 // Create agents for -agentlib: -agentpath: and converted -Xrun 929 // Invokes Agent_OnLoad 930 // Called very early -- before JavaThreads exist 931 void Threads::create_vm_init_agents() { 932 extern struct JavaVM_ main_vm; 933 AgentLibrary* agent; 934 935 JvmtiExport::enter_onload_phase(); 936 937 for (agent = Arguments::agents(); agent != nullptr; agent = agent->next()) { 938 // CDS dumping does not support native JVMTI agent. 939 // CDS dumping supports Java agent if the AllowArchivingWithJavaAgent diagnostic option is specified. 940 if (Arguments::is_dumping_archive()) { 941 if(!agent->is_instrument_lib()) { 942 vm_exit_during_cds_dumping("CDS dumping does not support native JVMTI agent, name", agent->name()); 943 } else if (!AllowArchivingWithJavaAgent) { 944 vm_exit_during_cds_dumping( 945 "Must enable AllowArchivingWithJavaAgent in order to run Java agent during CDS dumping"); 946 } 947 } 948 949 OnLoadEntry_t on_load_entry = lookup_agent_on_load(agent); 950 951 if (on_load_entry != nullptr) { 952 // Invoke the Agent_OnLoad function 953 jint err = (*on_load_entry)(&main_vm, agent->options(), nullptr); 954 if (err != JNI_OK) { 955 vm_exit_during_initialization("agent library failed to init", agent->name()); 956 } 957 } else { 958 vm_exit_during_initialization("Could not find Agent_OnLoad function in the agent library", agent->name()); 959 } 960 } 961 962 JvmtiExport::enter_primordial_phase(); 963 } 964 965 extern "C" { 966 typedef void (JNICALL *Agent_OnUnload_t)(JavaVM *); 967 } 968 969 void Threads::shutdown_vm_agents() { 970 // Send any Agent_OnUnload notifications 971 const char *on_unload_symbols[] = AGENT_ONUNLOAD_SYMBOLS; 972 size_t num_symbol_entries = ARRAY_SIZE(on_unload_symbols); 973 extern struct JavaVM_ main_vm; 974 for (AgentLibrary* agent = Arguments::agents(); agent != nullptr; agent = agent->next()) { 975 976 // Find the Agent_OnUnload function. 977 Agent_OnUnload_t unload_entry = CAST_TO_FN_PTR(Agent_OnUnload_t, 978 os::find_agent_function(agent, 979 false, 980 on_unload_symbols, 981 num_symbol_entries)); 982 983 // Invoke the Agent_OnUnload function 984 if (unload_entry != nullptr) { 985 JavaThread* thread = JavaThread::current(); 986 ThreadToNativeFromVM ttn(thread); 987 HandleMark hm(thread); 988 (*unload_entry)(&main_vm); 989 } 990 } 991 } 992 993 // Called for after the VM is initialized for -Xrun libraries which have not been converted to agent libraries 994 // Invokes JVM_OnLoad 995 void Threads::create_vm_init_libraries() { 996 extern struct JavaVM_ main_vm; 997 AgentLibrary* agent; 998 999 for (agent = Arguments::libraries(); agent != nullptr; agent = agent->next()) { 1000 OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent); 1001 1002 if (on_load_entry != nullptr) { 1003 // Invoke the JVM_OnLoad function 1004 JavaThread* thread = JavaThread::current(); 1005 ThreadToNativeFromVM ttn(thread); 1006 HandleMark hm(thread); 1007 jint err = (*on_load_entry)(&main_vm, agent->options(), nullptr); 1008 if (err != JNI_OK) { 1009 vm_exit_during_initialization("-Xrun library failed to init", agent->name()); 1010 } 1011 } else { 1012 vm_exit_during_initialization("Could not find JVM_OnLoad function in -Xrun library", agent->name()); 1013 } 1014 } 1015 } 1016 1017 // Threads::destroy_vm() is normally called from jni_DestroyJavaVM() when 1018 // the program falls off the end of main(). Another VM exit path is through 1019 // vm_exit() when the program calls System.exit() to return a value or when 1020 // there is a serious error in VM. The two shutdown paths are not exactly 1021 // the same, but they share Shutdown.shutdown() at Java level and before_exit() 1022 // and VM_Exit op at VM level. 1023 // 1024 // Shutdown sequence: 1025 // + Shutdown native memory tracking if it is on 1026 // + Wait until we are the last non-daemon thread to execute 1027 // <-- every thing is still working at this moment --> 1028 // + Call java.lang.Shutdown.shutdown(), which will invoke Java level 1029 // shutdown hooks 1030 // + Call before_exit(), prepare for VM exit 1031 // > run VM level shutdown hooks (they are registered through JVM_OnExit(), 1032 // currently the only user of this mechanism is File.deleteOnExit()) 1033 // > stop StatSampler, watcher thread, 1034 // post thread end and vm death events to JVMTI, 1035 // stop signal thread 1036 // + Call JavaThread::exit(), it will: 1037 // > release JNI handle blocks, remove stack guard pages 1038 // > remove this thread from Threads list 1039 // <-- no more Java code from this thread after this point --> 1040 // + Stop VM thread, it will bring the remaining VM to a safepoint and stop 1041 // the compiler threads at safepoint 1042 // <-- do not use anything that could get blocked by Safepoint --> 1043 // + Disable tracing at JNI/JVM barriers 1044 // + Set _vm_exited flag for threads that are still running native code 1045 // + Call exit_globals() 1046 // > deletes tty 1047 // > deletes PerfMemory resources 1048 // + Delete this thread 1049 // + Return to caller 1050 1051 void Threads::destroy_vm() { 1052 JavaThread* thread = JavaThread::current(); 1053 1054 #ifdef ASSERT 1055 _vm_complete = false; 1056 #endif 1057 // Wait until we are the last non-daemon thread to execute, or 1058 // if we are a daemon then wait until the last non-daemon thread has 1059 // executed. 1060 bool daemon = java_lang_Thread::is_daemon(thread->threadObj()); 1061 int expected = daemon ? 0 : 1; 1062 { 1063 MonitorLocker nu(Threads_lock); 1064 while (Threads::number_of_non_daemon_threads() > expected) 1065 // This wait should make safepoint checks, wait without a timeout. 1066 nu.wait(0); 1067 } 1068 1069 EventShutdown e; 1070 if (e.should_commit()) { 1071 e.set_reason("No remaining non-daemon Java threads"); 1072 e.commit(); 1073 } 1074 1075 // Hang forever on exit if we are reporting an error. 1076 if (ShowMessageBoxOnError && VMError::is_error_reported()) { 1077 os::infinite_sleep(); 1078 } 1079 os::wait_for_keypress_at_exit(); 1080 1081 // run Java level shutdown hooks 1082 thread->invoke_shutdown_hooks(); 1083 1084 before_exit(thread); 1085 1086 thread->exit(true); 1087 1088 // We are no longer on the main thread list but could still be in a 1089 // secondary list where another thread may try to interact with us. 1090 // So wait until all such interactions are complete before we bring 1091 // the VM to the termination safepoint. Normally this would be done 1092 // using thread->smr_delete() below where we delete the thread, but 1093 // we can't call that after the termination safepoint is active as 1094 // we will deadlock on the Threads_lock. Once all interactions are 1095 // complete it is safe to directly delete the thread at any time. 1096 ThreadsSMRSupport::wait_until_not_protected(thread); 1097 1098 // Stop VM thread. 1099 { 1100 // 4945125 The vm thread comes to a safepoint during exit. 1101 // GC vm_operations can get caught at the safepoint, and the 1102 // heap is unparseable if they are caught. Grab the Heap_lock 1103 // to prevent this. The GC vm_operations will not be able to 1104 // queue until after the vm thread is dead. After this point, 1105 // we'll never emerge out of the safepoint before the VM exits. 1106 // Assert that the thread is terminated so that acquiring the 1107 // Heap_lock doesn't cause the terminated thread to participate in 1108 // the safepoint protocol. 1109 1110 assert(thread->is_terminated(), "must be terminated here"); 1111 MutexLocker ml(Heap_lock); 1112 1113 VMThread::wait_for_vm_thread_exit(); 1114 assert(SafepointSynchronize::is_at_safepoint(), "VM thread should exit at Safepoint"); 1115 VMThread::destroy(); 1116 } 1117 1118 // Now, all Java threads are gone except daemon threads. Daemon threads 1119 // running Java code or in VM are stopped by the Safepoint. However, 1120 // daemon threads executing native code are still running. But they 1121 // will be stopped at native=>Java/VM barriers. Note that we can't 1122 // simply kill or suspend them, as it is inherently deadlock-prone. 1123 1124 VM_Exit::set_vm_exited(); 1125 1126 // Clean up ideal graph printers after the VMThread has started 1127 // the final safepoint which will block all the Compiler threads. 1128 // Note that this Thread has already logically exited so the 1129 // clean_up() function's use of a JavaThreadIteratorWithHandle 1130 // would be a problem except set_vm_exited() has remembered the 1131 // shutdown thread which is granted a policy exception. 1132 #if defined(COMPILER2) && !defined(PRODUCT) 1133 IdealGraphPrinter::clean_up(); 1134 #endif 1135 1136 notify_vm_shutdown(); 1137 1138 // exit_globals() will delete tty 1139 exit_globals(); 1140 1141 // Deleting the shutdown thread here is safe. See comment on 1142 // wait_until_not_protected() above. 1143 delete thread; 1144 1145 #if INCLUDE_JVMCI 1146 if (JVMCICounterSize > 0) { 1147 FREE_C_HEAP_ARRAY(jlong, JavaThread::_jvmci_old_thread_counters); 1148 } 1149 #endif 1150 1151 LogConfiguration::finalize(); 1152 } 1153 1154 1155 jboolean Threads::is_supported_jni_version_including_1_1(jint version) { 1156 if (version == JNI_VERSION_1_1) return JNI_TRUE; 1157 return is_supported_jni_version(version); 1158 } 1159 1160 1161 jboolean Threads::is_supported_jni_version(jint version) { 1162 if (version == JNI_VERSION_1_2) return JNI_TRUE; 1163 if (version == JNI_VERSION_1_4) return JNI_TRUE; 1164 if (version == JNI_VERSION_1_6) return JNI_TRUE; 1165 if (version == JNI_VERSION_1_8) return JNI_TRUE; 1166 if (version == JNI_VERSION_9) return JNI_TRUE; 1167 if (version == JNI_VERSION_10) return JNI_TRUE; 1168 if (version == JNI_VERSION_19) return JNI_TRUE; 1169 if (version == JNI_VERSION_20) return JNI_TRUE; 1170 return JNI_FALSE; 1171 } 1172 1173 void Threads::add(JavaThread* p, bool force_daemon) { 1174 // The threads lock must be owned at this point 1175 assert(Threads_lock->owned_by_self(), "must have threads lock"); 1176 1177 BarrierSet::barrier_set()->on_thread_attach(p); 1178 1179 // Once a JavaThread is added to the Threads list, smr_delete() has 1180 // to be used to delete it. Otherwise we can just delete it directly. 1181 p->set_on_thread_list(); 1182 1183 _number_of_threads++; 1184 oop threadObj = p->threadObj(); 1185 bool daemon = true; 1186 // Bootstrapping problem: threadObj can be null for initial 1187 // JavaThread (or for threads attached via JNI) 1188 if (!force_daemon && 1189 (threadObj == nullptr || !java_lang_Thread::is_daemon(threadObj))) { 1190 _number_of_non_daemon_threads++; 1191 daemon = false; 1192 } 1193 1194 ThreadService::add_thread(p, daemon); 1195 1196 // Maintain fast thread list 1197 ThreadsSMRSupport::add_thread(p); 1198 1199 // Increase the ObjectMonitor ceiling for the new thread. 1200 ObjectSynchronizer::inc_in_use_list_ceiling(); 1201 1202 // Possible GC point. 1203 Events::log(p, "Thread added: " INTPTR_FORMAT, p2i(p)); 1204 1205 // Make new thread known to active EscapeBarrier 1206 EscapeBarrier::thread_added(p); 1207 } 1208 1209 void Threads::remove(JavaThread* p, bool is_daemon) { 1210 // Extra scope needed for Thread_lock, so we can check 1211 // that we do not remove thread without safepoint code notice 1212 { MonitorLocker ml(Threads_lock); 1213 1214 if (ThreadIdTable::is_initialized()) { 1215 // This cleanup must be done before the current thread's GC barrier 1216 // is detached since we need to touch the threadObj oop. 1217 jlong tid = SharedRuntime::get_java_tid(p); 1218 ThreadIdTable::remove_thread(tid); 1219 } 1220 1221 // BarrierSet state must be destroyed after the last thread transition 1222 // before the thread terminates. Thread transitions result in calls to 1223 // StackWatermarkSet::on_safepoint(), which performs GC processing, 1224 // requiring the GC state to be alive. 1225 BarrierSet::barrier_set()->on_thread_detach(p); 1226 if (p->is_exiting()) { 1227 // If we got here via JavaThread::exit(), then we remember that the 1228 // thread's GC barrier has been detached. We don't do this when we get 1229 // here from another path, e.g., cleanup_failed_attach_current_thread(). 1230 p->set_terminated(JavaThread::_thread_gc_barrier_detached); 1231 } 1232 1233 assert(ThreadsSMRSupport::get_java_thread_list()->includes(p), "p must be present"); 1234 1235 // Maintain fast thread list 1236 ThreadsSMRSupport::remove_thread(p); 1237 1238 _number_of_threads--; 1239 if (!is_daemon) { 1240 _number_of_non_daemon_threads--; 1241 1242 // If this is the last non-daemon thread then we need to do 1243 // a notify on the Threads_lock so a thread waiting 1244 // on destroy_vm will wake up. But that thread could be a daemon 1245 // or non-daemon, so we notify for both the 0 and 1 case. 1246 if (number_of_non_daemon_threads() <= 1) { 1247 ml.notify_all(); 1248 } 1249 } 1250 ThreadService::remove_thread(p, is_daemon); 1251 1252 // Make sure that safepoint code disregard this thread. This is needed since 1253 // the thread might mess around with locks after this point. This can cause it 1254 // to do callbacks into the safepoint code. However, the safepoint code is not aware 1255 // of this thread since it is removed from the queue. 1256 p->set_terminated(JavaThread::_thread_terminated); 1257 1258 // Notify threads waiting in EscapeBarriers 1259 EscapeBarrier::thread_removed(p); 1260 } // unlock Threads_lock 1261 1262 // Reduce the ObjectMonitor ceiling for the exiting thread. 1263 ObjectSynchronizer::dec_in_use_list_ceiling(); 1264 1265 // Since Events::log uses a lock, we grab it outside the Threads_lock 1266 Events::log(p, "Thread exited: " INTPTR_FORMAT, p2i(p)); 1267 } 1268 1269 // Operations on the Threads list for GC. These are not explicitly locked, 1270 // but the garbage collector must provide a safe context for them to run. 1271 // In particular, these things should never be called when the Threads_lock 1272 // is held by some other thread. (Note: the Safepoint abstraction also 1273 // uses the Threads_lock to guarantee this property. It also makes sure that 1274 // all threads gets blocked when exiting or starting). 1275 1276 void Threads::oops_do(OopClosure* f, CodeBlobClosure* cf) { 1277 ALL_JAVA_THREADS(p) { 1278 p->oops_do(f, cf); 1279 } 1280 VMThread::vm_thread()->oops_do(f, cf); 1281 } 1282 1283 void Threads::change_thread_claim_token() { 1284 if (++_thread_claim_token == 0) { 1285 // On overflow of the token counter, there is a risk of future 1286 // collisions between a new global token value and a stale token 1287 // for a thread, because not all iterations visit all threads. 1288 // (Though it's pretty much a theoretical concern for non-trivial 1289 // token counter sizes.) To deal with the possibility, reset all 1290 // the thread tokens to zero on global token overflow. 1291 struct ResetClaims : public ThreadClosure { 1292 virtual void do_thread(Thread* t) { 1293 t->claim_threads_do(false, 0); 1294 } 1295 } reset_claims; 1296 Threads::threads_do(&reset_claims); 1297 // On overflow, update the global token to non-zero, to 1298 // avoid the special "never claimed" initial thread value. 1299 _thread_claim_token = 1; 1300 } 1301 } 1302 1303 #ifdef ASSERT 1304 void assert_thread_claimed(const char* kind, Thread* t, uintx expected) { 1305 const uintx token = t->threads_do_token(); 1306 assert(token == expected, 1307 "%s " PTR_FORMAT " has incorrect value " UINTX_FORMAT " != " 1308 UINTX_FORMAT, kind, p2i(t), token, expected); 1309 } 1310 1311 void Threads::assert_all_threads_claimed() { 1312 ALL_JAVA_THREADS(p) { 1313 assert_thread_claimed("JavaThread", p, _thread_claim_token); 1314 } 1315 1316 struct NJTClaimedVerifierClosure : public ThreadClosure { 1317 uintx _thread_claim_token; 1318 1319 NJTClaimedVerifierClosure(uintx thread_claim_token) : ThreadClosure(), _thread_claim_token(thread_claim_token) { } 1320 1321 virtual void do_thread(Thread* thread) override { 1322 assert_thread_claimed("Non-JavaThread", VMThread::vm_thread(), _thread_claim_token); 1323 } 1324 } tc(_thread_claim_token); 1325 1326 non_java_threads_do(&tc); 1327 } 1328 #endif // ASSERT 1329 1330 class ParallelOopsDoThreadClosure : public ThreadClosure { 1331 private: 1332 OopClosure* _f; 1333 CodeBlobClosure* _cf; 1334 public: 1335 ParallelOopsDoThreadClosure(OopClosure* f, CodeBlobClosure* cf) : _f(f), _cf(cf) {} 1336 void do_thread(Thread* t) { 1337 t->oops_do(_f, _cf); 1338 } 1339 }; 1340 1341 void Threads::possibly_parallel_oops_do(bool is_par, OopClosure* f, CodeBlobClosure* cf) { 1342 ParallelOopsDoThreadClosure tc(f, cf); 1343 possibly_parallel_threads_do(is_par, &tc); 1344 } 1345 1346 void Threads::metadata_do(MetadataClosure* f) { 1347 ALL_JAVA_THREADS(p) { 1348 p->metadata_do(f); 1349 } 1350 } 1351 1352 class ThreadHandlesClosure : public ThreadClosure { 1353 void (*_f)(Metadata*); 1354 public: 1355 ThreadHandlesClosure(void f(Metadata*)) : _f(f) {} 1356 virtual void do_thread(Thread* thread) { 1357 thread->metadata_handles_do(_f); 1358 } 1359 }; 1360 1361 void Threads::metadata_handles_do(void f(Metadata*)) { 1362 // Only walk the Handles in Thread. 1363 ThreadHandlesClosure handles_closure(f); 1364 threads_do(&handles_closure); 1365 } 1366 1367 // Get count Java threads that are waiting to enter the specified monitor. 1368 GrowableArray<JavaThread*>* Threads::get_pending_threads(ThreadsList * t_list, 1369 int count, 1370 address monitor) { 1371 GrowableArray<JavaThread*>* result = new GrowableArray<JavaThread*>(count); 1372 1373 int i = 0; 1374 for (JavaThread* p : *t_list) { 1375 if (!p->can_call_java()) continue; 1376 1377 // The first stage of async deflation does not affect any field 1378 // used by this comparison so the ObjectMonitor* is usable here. 1379 address pending = (address)p->current_pending_monitor(); 1380 if (pending == monitor) { // found a match 1381 if (i < count) result->append(p); // save the first count matches 1382 i++; 1383 } 1384 } 1385 1386 return result; 1387 } 1388 1389 1390 JavaThread *Threads::owning_thread_from_monitor_owner(ThreadsList * t_list, 1391 address owner) { 1392 assert(!UseFastLocking, "only with stack-locking"); 1393 // null owner means not locked so we can skip the search 1394 if (owner == nullptr) return nullptr; 1395 1396 for (JavaThread* p : *t_list) { 1397 // first, see if owner is the address of a Java thread 1398 if (owner == (address)p) return p; 1399 } 1400 1401 // Cannot assert on lack of success here since this function may be 1402 // used by code that is trying to report useful problem information 1403 // like deadlock detection. 1404 if (UseHeavyMonitors) return nullptr; 1405 1406 // If we didn't find a matching Java thread and we didn't force use of 1407 // heavyweight monitors, then the owner is the stack address of the 1408 // Lock Word in the owning Java thread's stack. 1409 // 1410 JavaThread* the_owner = nullptr; 1411 for (JavaThread* q : *t_list) { 1412 if (q->is_lock_owned(owner)) { 1413 the_owner = q; 1414 break; 1415 } 1416 } 1417 1418 // cannot assert on lack of success here; see above comment 1419 return the_owner; 1420 } 1421 1422 JavaThread* Threads::owning_thread_from_object(ThreadsList * t_list, oop obj) { 1423 assert(UseFastLocking, "Only with fast-locking"); 1424 for (JavaThread* q : *t_list) { 1425 if (q->lock_stack().contains(obj)) { 1426 return q; 1427 } 1428 } 1429 return nullptr; 1430 } 1431 1432 JavaThread* Threads::owning_thread_from_monitor(ThreadsList* t_list, ObjectMonitor* monitor) { 1433 if (UseFastLocking) { 1434 if (monitor->is_owner_anonymous()) { 1435 return owning_thread_from_object(t_list, monitor->object()); 1436 } else { 1437 Thread* owner = reinterpret_cast<Thread*>(monitor->owner()); 1438 assert(owner == nullptr || owner->is_Java_thread(), "only JavaThreads own monitors"); 1439 return reinterpret_cast<JavaThread*>(owner); 1440 } 1441 } else { 1442 address owner = (address)monitor->owner(); 1443 return owning_thread_from_monitor_owner(t_list, owner); 1444 } 1445 } 1446 1447 class PrintOnClosure : public ThreadClosure { 1448 private: 1449 outputStream* _st; 1450 1451 public: 1452 PrintOnClosure(outputStream* st) : 1453 _st(st) {} 1454 1455 virtual void do_thread(Thread* thread) { 1456 if (thread != nullptr) { 1457 thread->print_on(_st); 1458 _st->cr(); 1459 } 1460 } 1461 }; 1462 1463 // Threads::print_on() is called at safepoint by VM_PrintThreads operation. 1464 void Threads::print_on(outputStream* st, bool print_stacks, 1465 bool internal_format, bool print_concurrent_locks, 1466 bool print_extended_info) { 1467 char buf[32]; 1468 st->print_raw_cr(os::local_time_string(buf, sizeof(buf))); 1469 1470 st->print_cr("Full thread dump %s (%s %s):", 1471 VM_Version::vm_name(), 1472 VM_Version::vm_release(), 1473 VM_Version::vm_info_string()); 1474 st->cr(); 1475 1476 #if INCLUDE_SERVICES 1477 // Dump concurrent locks 1478 ConcurrentLocksDump concurrent_locks; 1479 if (print_concurrent_locks) { 1480 concurrent_locks.dump_at_safepoint(); 1481 } 1482 #endif // INCLUDE_SERVICES 1483 1484 ThreadsSMRSupport::print_info_on(st); 1485 st->cr(); 1486 1487 ALL_JAVA_THREADS(p) { 1488 ResourceMark rm; 1489 p->print_on(st, print_extended_info); 1490 if (print_stacks) { 1491 if (internal_format) { 1492 p->trace_stack(); 1493 } else { 1494 p->print_stack_on(st); 1495 } 1496 } 1497 st->cr(); 1498 #if INCLUDE_SERVICES 1499 if (print_concurrent_locks) { 1500 concurrent_locks.print_locks_on(p, st); 1501 } 1502 #endif // INCLUDE_SERVICES 1503 } 1504 1505 PrintOnClosure cl(st); 1506 cl.do_thread(VMThread::vm_thread()); 1507 Universe::heap()->gc_threads_do(&cl); 1508 if (StringDedup::is_enabled()) { 1509 StringDedup::threads_do(&cl); 1510 } 1511 cl.do_thread(WatcherThread::watcher_thread()); 1512 cl.do_thread(AsyncLogWriter::instance()); 1513 1514 st->flush(); 1515 } 1516 1517 void Threads::print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf, 1518 int buflen, bool* found_current) { 1519 if (this_thread != nullptr) { 1520 bool is_current = (current == this_thread); 1521 *found_current = *found_current || is_current; 1522 st->print("%s", is_current ? "=>" : " "); 1523 1524 st->print(PTR_FORMAT, p2i(this_thread)); 1525 st->print(" "); 1526 this_thread->print_on_error(st, buf, buflen); 1527 st->cr(); 1528 } 1529 } 1530 1531 class PrintOnErrorClosure : public ThreadClosure { 1532 outputStream* _st; 1533 Thread* _current; 1534 char* _buf; 1535 int _buflen; 1536 bool* _found_current; 1537 public: 1538 PrintOnErrorClosure(outputStream* st, Thread* current, char* buf, 1539 int buflen, bool* found_current) : 1540 _st(st), _current(current), _buf(buf), _buflen(buflen), _found_current(found_current) {} 1541 1542 virtual void do_thread(Thread* thread) { 1543 Threads::print_on_error(thread, _st, _current, _buf, _buflen, _found_current); 1544 } 1545 }; 1546 1547 // Threads::print_on_error() is called by fatal error handler. It's possible 1548 // that VM is not at safepoint and/or current thread is inside signal handler. 1549 // Don't print stack trace, as the stack may not be walkable. Don't allocate 1550 // memory (even in resource area), it might deadlock the error handler. 1551 void Threads::print_on_error(outputStream* st, Thread* current, char* buf, 1552 int buflen) { 1553 ThreadsSMRSupport::print_info_on(st); 1554 st->cr(); 1555 1556 bool found_current = false; 1557 st->print_cr("Java Threads: ( => current thread )"); 1558 ALL_JAVA_THREADS(thread) { 1559 print_on_error(thread, st, current, buf, buflen, &found_current); 1560 } 1561 st->cr(); 1562 1563 st->print_cr("Other Threads:"); 1564 print_on_error(VMThread::vm_thread(), st, current, buf, buflen, &found_current); 1565 print_on_error(WatcherThread::watcher_thread(), st, current, buf, buflen, &found_current); 1566 print_on_error(AsyncLogWriter::instance(), st, current, buf, buflen, &found_current); 1567 1568 if (Universe::heap() != nullptr) { 1569 PrintOnErrorClosure print_closure(st, current, buf, buflen, &found_current); 1570 Universe::heap()->gc_threads_do(&print_closure); 1571 } 1572 1573 if (StringDedup::is_enabled()) { 1574 PrintOnErrorClosure print_closure(st, current, buf, buflen, &found_current); 1575 StringDedup::threads_do(&print_closure); 1576 } 1577 1578 if (!found_current) { 1579 st->cr(); 1580 st->print("=>" PTR_FORMAT " (exited) ", p2i(current)); 1581 current->print_on_error(st, buf, buflen); 1582 st->cr(); 1583 } 1584 st->cr(); 1585 1586 st->print_cr("Threads with active compile tasks:"); 1587 print_threads_compiling(st, buf, buflen); 1588 } 1589 1590 void Threads::print_threads_compiling(outputStream* st, char* buf, int buflen, bool short_form) { 1591 ALL_JAVA_THREADS(thread) { 1592 if (thread->is_Compiler_thread()) { 1593 CompilerThread* ct = (CompilerThread*) thread; 1594 1595 // Keep task in local variable for null check. 1596 // ct->_task might be set to null by concurring compiler thread 1597 // because it completed the compilation. The task is never freed, 1598 // though, just returned to a free list. 1599 CompileTask* task = ct->task(); 1600 if (task != nullptr) { 1601 thread->print_name_on_error(st, buf, buflen); 1602 st->print(" "); 1603 task->print(st, nullptr, short_form, true); 1604 } 1605 } 1606 } 1607 } 1608 1609 void Threads::verify() { 1610 ALL_JAVA_THREADS(p) { 1611 p->verify(); 1612 } 1613 VMThread* thread = VMThread::vm_thread(); 1614 if (thread != nullptr) thread->verify(); 1615 }