1
2 /*
3 * Copyright (c) 1997, 2025, Oracle and/or its affiliates. All rights reserved.
4 * Copyright (c) 2021, Azul Systems, Inc. All rights reserved.
5 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
6 *
7 * This code is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License version 2 only, as
9 * published by the Free Software Foundation.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 *
25 */
26
27 #include "cds/aotLinkedClassBulkLoader.hpp"
28 #include "cds/cds_globals.hpp"
29 #include "cds/cdsConfig.hpp"
30 #include "cds/heapShared.hpp"
31 #include "cds/metaspaceShared.hpp"
32 #include "classfile/classLoader.hpp"
33 #include "classfile/javaClasses.hpp"
34 #include "classfile/javaThreadStatus.hpp"
35 #include "classfile/symbolTable.hpp"
36 #include "classfile/systemDictionary.hpp"
37 #include "classfile/vmClasses.hpp"
38 #include "classfile/vmSymbols.hpp"
39 #include "compiler/compileBroker.hpp"
40 #include "compiler/compileTask.hpp"
41 #include "compiler/compilerThread.hpp"
42 #include "gc/shared/barrierSet.hpp"
43 #include "gc/shared/barrierSetNMethod.hpp"
44 #include "gc/shared/gcVMOperations.hpp"
45 #include "gc/shared/oopStorage.hpp"
46 #include "gc/shared/oopStorageSet.hpp"
47 #include "gc/shared/stringdedup/stringDedup.hpp"
48 #include "jfr/jfrEvents.hpp"
49 #include "jvm.h"
50 #include "jvmtifiles/jvmtiEnv.hpp"
51 #include "logging/log.hpp"
52 #include "logging/logAsyncWriter.hpp"
53 #include "logging/logConfiguration.hpp"
54 #include "memory/allocation.inline.hpp"
55 #include "memory/iterator.hpp"
56 #include "memory/oopFactory.hpp"
57 #include "memory/resourceArea.hpp"
58 #include "memory/universe.hpp"
59 #include "nmt/memTracker.hpp"
60 #include "oops/instanceKlass.hpp"
61 #include "oops/klass.inline.hpp"
62 #include "oops/oop.inline.hpp"
63 #include "oops/symbol.hpp"
64 #include "prims/jvm_misc.hpp"
65 #include "prims/jvmtiAgentList.hpp"
66 #include "prims/jvmtiEnvBase.hpp"
67 #include "runtime/arguments.hpp"
68 #include "runtime/fieldDescriptor.inline.hpp"
69 #include "runtime/flags/jvmFlagLimit.hpp"
70 #include "runtime/globals.hpp"
71 #include "runtime/globals_extension.hpp"
72 #include "runtime/handles.inline.hpp"
73 #include "runtime/interfaceSupport.inline.hpp"
74 #include "runtime/java.hpp"
75 #include "runtime/javaCalls.hpp"
76 #include "runtime/javaThread.inline.hpp"
77 #include "runtime/jniHandles.inline.hpp"
78 #include "runtime/jniPeriodicChecker.hpp"
79 #include "runtime/lockStack.inline.hpp"
80 #include "runtime/monitorDeflationThread.hpp"
81 #include "runtime/mutexLocker.hpp"
82 #include "runtime/nonJavaThread.hpp"
83 #include "runtime/objectMonitor.inline.hpp"
84 #include "runtime/osThread.hpp"
85 #include "runtime/perfData.hpp"
86 #include "runtime/safepoint.hpp"
87 #include "runtime/safepointMechanism.inline.hpp"
88 #include "runtime/safepointVerifiers.hpp"
89 #include "runtime/serviceThread.hpp"
90 #include "runtime/sharedRuntime.hpp"
91 #include "runtime/stackWatermarkSet.inline.hpp"
92 #include "runtime/stubCodeGenerator.hpp"
93 #include "runtime/thread.inline.hpp"
94 #include "runtime/threadSMR.inline.hpp"
95 #include "runtime/threads.hpp"
96 #include "runtime/timer.hpp"
97 #include "runtime/timerTrace.hpp"
98 #include "runtime/trimNativeHeap.hpp"
99 #include "runtime/vmOperations.hpp"
100 #include "runtime/vm_version.hpp"
101 #include "services/attachListener.hpp"
102 #include "services/management.hpp"
103 #include "services/threadIdTable.hpp"
104 #include "services/threadService.hpp"
105 #include "utilities/dtrace.hpp"
106 #include "utilities/events.hpp"
107 #include "utilities/macros.hpp"
108 #include "utilities/vmError.hpp"
109 #if INCLUDE_JVMCI
110 #include "jvmci/jvmci.hpp"
111 #include "jvmci/jvmciEnv.hpp"
112 #endif
113 #ifdef COMPILER2
114 #include "opto/idealGraphPrinter.hpp"
115 #endif
116 #if INCLUDE_JFR
117 #include "jfr/jfr.hpp"
118 #endif
119
120 // Initialization after module runtime initialization
121 void universe_post_module_init(); // must happen after call_initPhase2
122
123
124 static void initialize_class(Symbol* class_name, TRAPS) {
125 Klass* klass = SystemDictionary::resolve_or_fail(class_name, true, CHECK);
126 InstanceKlass::cast(klass)->initialize(CHECK);
127 }
128
129
130 // Creates the initial ThreadGroup
131 static Handle create_initial_thread_group(TRAPS) {
132 Handle system_instance = JavaCalls::construct_new_instance(
133 vmClasses::ThreadGroup_klass(),
134 vmSymbols::void_method_signature(),
135 CHECK_NH);
136 Universe::set_system_thread_group(system_instance());
137
138 Handle string = java_lang_String::create_from_str("main", CHECK_NH);
139 Handle main_instance = JavaCalls::construct_new_instance(
140 vmClasses::ThreadGroup_klass(),
141 vmSymbols::threadgroup_string_void_signature(),
142 system_instance,
143 string,
144 CHECK_NH);
145 return main_instance;
146 }
147
148 // Creates the initial Thread, and sets it to running.
149 static void create_initial_thread(Handle thread_group, JavaThread* thread,
150 TRAPS) {
151 InstanceKlass* ik = vmClasses::Thread_klass();
152 assert(ik->is_initialized(), "must be");
153 instanceHandle thread_oop = ik->allocate_instance_handle(CHECK);
154
155 // Cannot use JavaCalls::construct_new_instance because the java.lang.Thread
156 // constructor calls Thread.current(), which must be set here for the
157 // initial thread.
158 java_lang_Thread::set_thread(thread_oop(), thread);
159 thread->set_threadOopHandles(thread_oop());
160
161 Handle string = java_lang_String::create_from_str("main", CHECK);
162
163 JavaValue result(T_VOID);
164 JavaCalls::call_special(&result, thread_oop,
165 ik,
166 vmSymbols::object_initializer_name(),
167 vmSymbols::threadgroup_string_void_signature(),
168 thread_group,
169 string,
170 CHECK);
171
172 DEBUG_ONLY(int64_t main_thread_tid = java_lang_Thread::thread_id(thread_oop());)
173 assert(main_thread_tid == ThreadIdentifier::initial(), "");
174 assert(main_thread_tid == thread->monitor_owner_id(), "");
175 JFR_ONLY(assert(JFR_JVM_THREAD_ID(thread) == static_cast<traceid>(main_thread_tid), "initial tid mismatch");)
176
177 // Set thread status to running since main thread has
178 // been started and running.
179 java_lang_Thread::set_thread_status(thread_oop(),
180 JavaThreadStatus::RUNNABLE);
181 }
182
183 // Extract version and vendor specific information from
184 // java.lang.VersionProps fields.
185 // Returned char* is allocated in the thread's resource area
186 // so must be copied for permanency.
187 static const char* get_java_version_info(InstanceKlass* ik,
188 Symbol* field_name) {
189 fieldDescriptor fd;
190 bool found = ik != nullptr &&
191 ik->find_local_field(field_name,
192 vmSymbols::string_signature(), &fd);
193 if (found) {
194 oop name_oop = ik->java_mirror()->obj_field(fd.offset());
195 if (name_oop == nullptr) {
196 return nullptr;
197 }
198 const char* name = java_lang_String::as_utf8_string(name_oop);
199 return name;
200 } else {
201 return nullptr;
202 }
203 }
204
205 // ======= Threads ========
206
207 // The Threads class links together all active threads, and provides
208 // operations over all threads. It is protected by the Threads_lock,
209 // which is also used in other global contexts like safepointing.
210 // ThreadsListHandles are used to safely perform operations on one
211 // or more threads without the risk of the thread exiting during the
212 // operation.
213 //
214 // Note: The Threads_lock is currently more widely used than we
215 // would like. We are actively migrating Threads_lock uses to other
216 // mechanisms in order to reduce Threads_lock contention.
217
218 int Threads::_number_of_threads = 0;
219 int Threads::_number_of_non_daemon_threads = 0;
220 int Threads::_return_code = 0;
221 uintx Threads::_thread_claim_token = 1; // Never zero.
222
223 #ifdef ASSERT
224 bool Threads::_vm_complete = false;
225 #endif
226
227 // General purpose hook into Java code, run once when the VM is initialized.
228 // The Java library method itself may be changed independently from the VM.
229 static void call_postVMInitHook(TRAPS) {
230 Klass* klass = SystemDictionary::resolve_or_null(vmSymbols::jdk_internal_vm_PostVMInitHook(), THREAD);
231 if (klass != nullptr) {
232 JavaValue result(T_VOID);
233 JavaCalls::call_static(&result, klass, vmSymbols::run_method_name(),
234 vmSymbols::void_method_signature(),
235 CHECK);
236 }
237 }
238
239 // All NonJavaThreads (i.e., every non-JavaThread in the system).
240 void Threads::non_java_threads_do(ThreadClosure* tc) {
241 NoSafepointVerifier nsv;
242 for (NonJavaThread::Iterator njti; !njti.end(); njti.step()) {
243 tc->do_thread(njti.current());
244 }
245 }
246
247 // All JavaThreads
248 #define ALL_JAVA_THREADS(X) \
249 for (JavaThread* X : *ThreadsSMRSupport::get_java_thread_list())
250
251 // All JavaThreads
252 void Threads::java_threads_do(ThreadClosure* tc) {
253 assert_locked_or_safepoint(Threads_lock);
254 // ALL_JAVA_THREADS iterates through all JavaThreads.
255 ALL_JAVA_THREADS(p) {
256 tc->do_thread(p);
257 }
258 }
259
260 // All JavaThreads + all non-JavaThreads (i.e., every thread in the system).
261 void Threads::threads_do(ThreadClosure* tc) {
262 assert_locked_or_safepoint(Threads_lock);
263 java_threads_do(tc);
264 non_java_threads_do(tc);
265 }
266
267 void Threads::possibly_parallel_threads_do(bool is_par, ThreadClosure* tc) {
268 assert_at_safepoint();
269
270 uintx claim_token = Threads::thread_claim_token();
271 ALL_JAVA_THREADS(p) {
272 if (p->claim_threads_do(is_par, claim_token)) {
273 tc->do_thread(p);
274 }
275 }
276 for (NonJavaThread::Iterator njti; !njti.end(); njti.step()) {
277 Thread* current = njti.current();
278 if (current->claim_threads_do(is_par, claim_token)) {
279 tc->do_thread(current);
280 }
281 }
282 }
283
284 // The system initialization in the library has three phases.
285 //
286 // Phase 1: java.lang.System class initialization
287 // java.lang.System is a primordial class loaded and initialized
288 // by the VM early during startup. java.lang.System.<clinit>
289 // only does registerNatives and keeps the rest of the class
290 // initialization work later until thread initialization completes.
291 //
292 // System.initPhase1 initializes the system properties, the static
293 // fields in, out, and err. Set up java signal handlers, OS-specific
294 // system settings, and thread group of the main thread.
295 static void call_initPhase1(TRAPS) {
296 Klass* klass = vmClasses::System_klass();
297 JavaValue result(T_VOID);
298 JavaCalls::call_static(&result, klass, vmSymbols::initPhase1_name(),
299 vmSymbols::void_method_signature(), CHECK);
300 }
301
302 // Phase 2. Module system initialization
303 // This will initialize the module system. Only java.base classes
304 // can be loaded until phase 2 completes.
305 //
306 // Call System.initPhase2 after the compiler initialization and jsr292
307 // classes get initialized because module initialization runs a lot of java
308 // code, that for performance reasons, should be compiled. Also, this will
309 // enable the startup code to use lambda and other language features in this
310 // phase and onward.
311 //
312 // After phase 2, The VM will begin search classes from -Xbootclasspath/a.
313 static void call_initPhase2(TRAPS) {
314 TraceTime timer("Initialize module system", TRACETIME_LOG(Info, startuptime));
315
316 Klass* klass = vmClasses::System_klass();
317
318 JavaValue result(T_INT);
319 JavaCallArguments args;
320 args.push_int(DisplayVMOutputToStderr);
321 args.push_int(log_is_enabled(Debug, init)); // print stack trace if exception thrown
322 JavaCalls::call_static(&result, klass, vmSymbols::initPhase2_name(),
323 vmSymbols::boolean_boolean_int_signature(), &args, CHECK);
324 if (result.get_jint() != JNI_OK) {
325 vm_exit_during_initialization(); // no message or exception
326 }
327
328 universe_post_module_init();
329 }
330
331 // Phase 3. final setup - set security manager, system class loader and TCCL
332 //
333 // This will instantiate and set the security manager, set the system class
334 // loader as well as the thread context class loader. The security manager
335 // and system class loader may be a custom class loaded from -Xbootclasspath/a,
336 // other modules or the application's classpath.
337 static void call_initPhase3(TRAPS) {
338 Klass* klass = vmClasses::System_klass();
339 JavaValue result(T_VOID);
340 JavaCalls::call_static(&result, klass, vmSymbols::initPhase3_name(),
341 vmSymbols::void_method_signature(), CHECK);
342 }
343
344 void Threads::initialize_java_lang_classes(JavaThread* main_thread, TRAPS) {
345 TraceTime timer("Initialize java.lang classes", TRACETIME_LOG(Info, startuptime));
346
347 initialize_class(vmSymbols::java_lang_String(), CHECK);
348
349 // Inject CompactStrings value after the static initializers for String ran.
350 java_lang_String::set_compact_strings(CompactStrings);
351
352 // Initialize java_lang.System (needed before creating the thread)
353 initialize_class(vmSymbols::java_lang_System(), CHECK);
354 // The VM creates & returns objects of this class. Make sure it's initialized.
355 initialize_class(vmSymbols::java_lang_Class(), CHECK);
356
357 initialize_class(vmSymbols::java_lang_ThreadGroup(), CHECK);
358 Handle thread_group = create_initial_thread_group(CHECK);
359 Universe::set_main_thread_group(thread_group());
360 initialize_class(vmSymbols::java_lang_Thread(), CHECK);
361 create_initial_thread(thread_group, main_thread, CHECK);
362
363 HeapShared::init_box_classes(CHECK);
364
365 // The VM creates objects of this class.
366 initialize_class(vmSymbols::java_lang_Module(), CHECK);
367
368 #ifdef ASSERT
369 InstanceKlass *k = vmClasses::UnsafeConstants_klass();
370 assert(k->is_not_initialized(), "UnsafeConstants should not already be initialized");
371 #endif
372
373 // initialize the hardware-specific constants needed by Unsafe
374 initialize_class(vmSymbols::jdk_internal_misc_UnsafeConstants(), CHECK);
375 jdk_internal_misc_UnsafeConstants::set_unsafe_constants();
376
377 // The VM preresolves methods to these classes. Make sure that they get initialized
378 initialize_class(vmSymbols::java_lang_reflect_Method(), CHECK);
379 initialize_class(vmSymbols::java_lang_ref_Finalizer(), CHECK);
380
381 // Phase 1 of the system initialization in the library, java.lang.System class initialization
382 call_initPhase1(CHECK);
383
384 // Get the Java runtime name, version, and vendor info after java.lang.System is initialized.
385 // Some values are actually configure-time constants but some can be set via the jlink tool and
386 // so must be read dynamically. We treat them all the same.
387 InstanceKlass* ik = SystemDictionary::find_instance_klass(THREAD, vmSymbols::java_lang_VersionProps(),
388 Handle());
389 {
390 ResourceMark rm(main_thread);
391 JDK_Version::set_java_version(get_java_version_info(ik, vmSymbols::java_version_name()));
392
393 JDK_Version::set_runtime_name(get_java_version_info(ik, vmSymbols::java_runtime_name_name()));
394
395 JDK_Version::set_runtime_version(get_java_version_info(ik, vmSymbols::java_runtime_version_name()));
396
397 JDK_Version::set_runtime_vendor_version(get_java_version_info(ik, vmSymbols::java_runtime_vendor_version_name()));
398
399 JDK_Version::set_runtime_vendor_vm_bug_url(get_java_version_info(ik, vmSymbols::java_runtime_vendor_vm_bug_url_name()));
400 }
401
402 // an instance of OutOfMemory exception has been allocated earlier
403 initialize_class(vmSymbols::java_lang_OutOfMemoryError(), CHECK);
404 initialize_class(vmSymbols::java_lang_NullPointerException(), CHECK);
405 initialize_class(vmSymbols::java_lang_ClassCastException(), CHECK);
406 initialize_class(vmSymbols::java_lang_ArrayStoreException(), CHECK);
407 initialize_class(vmSymbols::java_lang_ArithmeticException(), CHECK);
408 initialize_class(vmSymbols::jdk_internal_vm_PreemptedException(), CHECK);
409 initialize_class(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), CHECK);
410 initialize_class(vmSymbols::java_lang_StackOverflowError(), CHECK);
411 initialize_class(vmSymbols::java_lang_IllegalMonitorStateException(), CHECK);
412 initialize_class(vmSymbols::java_lang_IllegalArgumentException(), CHECK);
413 initialize_class(vmSymbols::java_lang_InternalError(), CHECK);
414 }
415
416 void Threads::initialize_jsr292_core_classes(TRAPS) {
417 TraceTime timer("Initialize java.lang.invoke classes", TRACETIME_LOG(Info, startuptime));
418
419 initialize_class(vmSymbols::java_lang_invoke_MethodHandle(), CHECK);
420 initialize_class(vmSymbols::java_lang_invoke_ResolvedMethodName(), CHECK);
421 initialize_class(vmSymbols::java_lang_invoke_MemberName(), CHECK);
422 initialize_class(vmSymbols::java_lang_invoke_MethodHandleNatives(), CHECK);
423
424 if (UseSharedSpaces) {
425 HeapShared::initialize_java_lang_invoke(CHECK);
426 }
427 }
428
429 // One-shot PeriodicTask subclass for reading the release file
430 class ReadReleaseFileTask : public PeriodicTask {
431 public:
432 ReadReleaseFileTask() : PeriodicTask(100) {}
433
434 virtual void task() {
435 os::read_image_release_file();
436
437 // Reclaim our storage and disenroll ourself.
438 delete this;
439 }
440 };
441
442 jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) {
443 extern void JDK_Version_init();
444
445 // Preinitialize version info.
446 VM_Version::early_initialize();
447
448 // Check version
449 if (!is_supported_jni_version(args->version)) return JNI_EVERSION;
450
451 // Initialize library-based TLS
452 ThreadLocalStorage::init();
453
454 // Initialize the output stream module
455 ostream_init();
456
457 // Process java launcher properties.
458 Arguments::process_sun_java_launcher_properties(args);
459
460 // Initialize the os module
461 os::init();
462
463 // Initialize memory pools
464 Arena::initialize_chunk_pool();
465
466 MACOS_AARCH64_ONLY(os::current_thread_enable_wx(WXWrite));
467
468 // Record VM creation timing statistics
469 TraceVmCreationTime create_vm_timer;
470 create_vm_timer.start();
471
472 // Initialize system properties.
473 Arguments::init_system_properties();
474
475 // So that JDK version can be used as a discriminator when parsing arguments
476 JDK_Version_init();
477
478 // Update/Initialize System properties after JDK version number is known
479 Arguments::init_version_specific_system_properties();
480
481 // Make sure to initialize log configuration *before* parsing arguments
482 LogConfiguration::initialize(create_vm_timer.begin_time());
483
484 // Parse arguments
485 // Note: this internally calls os::init_container_support()
486 jint parse_result = Arguments::parse(args);
487 if (parse_result != JNI_OK) return parse_result;
488
489 // Initialize NMT right after argument parsing to keep the pre-NMT-init window small.
490 MemTracker::initialize();
491
492 os::init_before_ergo();
493
494 jint ergo_result = Arguments::apply_ergo();
495 if (ergo_result != JNI_OK) return ergo_result;
496
497 // Final check of all ranges after ergonomics which may change values.
498 if (!JVMFlagLimit::check_all_ranges()) {
499 return JNI_EINVAL;
500 }
501
502 // Final check of all 'AfterErgo' constraints after ergonomics which may change values.
503 bool constraint_result = JVMFlagLimit::check_all_constraints(JVMFlagConstraintPhase::AfterErgo);
504 if (!constraint_result) {
505 return JNI_EINVAL;
506 }
507
508 if (PauseAtStartup) {
509 os::pause();
510 }
511
512 HOTSPOT_VM_INIT_BEGIN();
513
514 // Timing (must come after argument parsing)
515 TraceTime timer("Create VM", TRACETIME_LOG(Info, startuptime));
516
517 // Initialize the os module after parsing the args
518 jint os_init_2_result = os::init_2();
519 if (os_init_2_result != JNI_OK) return os_init_2_result;
520
521 #ifdef CAN_SHOW_REGISTERS_ON_ASSERT
522 // Initialize assert poison page mechanism.
523 if (ShowRegistersOnAssert) {
524 initialize_assert_poison();
525 }
526 #endif // CAN_SHOW_REGISTERS_ON_ASSERT
527
528 SafepointMechanism::initialize();
529
530 jint adjust_after_os_result = Arguments::adjust_after_os();
531 if (adjust_after_os_result != JNI_OK) return adjust_after_os_result;
532
533 // Initialize output stream logging
534 ostream_init_log();
535
536 // Launch -agentlib/-agentpath and converted -Xrun agents
537 JvmtiAgentList::load_agents();
538
539 // Initialize Threads state
540 _number_of_threads = 0;
541 _number_of_non_daemon_threads = 0;
542
543 // Initialize global data structures and create system classes in heap
544 vm_init_globals();
545
546 #if INCLUDE_JVMCI
547 if (JVMCICounterSize > 0) {
548 JavaThread::_jvmci_old_thread_counters = NEW_C_HEAP_ARRAY(jlong, JVMCICounterSize, mtJVMCI);
549 memset(JavaThread::_jvmci_old_thread_counters, 0, sizeof(jlong) * JVMCICounterSize);
550 } else {
551 JavaThread::_jvmci_old_thread_counters = nullptr;
552 }
553 #endif // INCLUDE_JVMCI
554
555 // Initialize OopStorage for threadObj
556 JavaThread::_thread_oop_storage = OopStorageSet::create_strong("Thread OopStorage", mtThread);
557
558 // Attach the main thread to this os thread
559 JavaThread* main_thread = new JavaThread();
560 main_thread->set_thread_state(_thread_in_vm);
561 main_thread->initialize_thread_current();
562 // Once mutexes and main_thread are ready, we can use NmtVirtualMemoryLocker.
563 MemTracker::NmtVirtualMemoryLocker::set_safe_to_use();
564 // must do this before set_active_handles
565 main_thread->record_stack_base_and_size();
566 main_thread->register_thread_stack_with_NMT();
567 main_thread->set_active_handles(JNIHandleBlock::allocate_block());
568 MACOS_AARCH64_ONLY(main_thread->init_wx());
569
570 // Set the _monitor_owner_id now since we will run Java code before the Thread instance
571 // is even created. The same value will be assigned to the Thread instance on init.
572 main_thread->set_monitor_owner_id(ThreadIdentifier::next());
573
574 if (!Thread::set_as_starting_thread(main_thread)) {
575 vm_shutdown_during_initialization(
576 "Failed necessary internal allocation. Out of swap space");
577 main_thread->smr_delete();
578 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
579 return JNI_ENOMEM;
580 }
581
582 JFR_ONLY(Jfr::initialize_main_thread(main_thread);)
583
584 // Enable guard page *after* os::create_main_thread(), otherwise it would
585 // crash Linux VM, see notes in os_linux.cpp.
586 main_thread->stack_overflow_state()->create_stack_guard_pages();
587
588 // Initialize Java-Level synchronization subsystem
589 ObjectMonitor::Initialize();
590 ObjectSynchronizer::initialize();
591
592 // Initialize global modules
593 jint status = init_globals();
594 if (status != JNI_OK) {
595 main_thread->smr_delete();
596 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
597 return status;
598 }
599
600 // Have the WatcherThread read the release file in the background.
601 ReadReleaseFileTask* read_task = new ReadReleaseFileTask();
602 read_task->enroll();
603
604 // Create WatcherThread as soon as we can since we need it in case
605 // of hangs during error reporting.
606 WatcherThread::start();
607
608 // Add main_thread to threads list to finish barrier setup with
609 // on_thread_attach. Should be before starting to build Java objects in
610 // init_globals2, which invokes barriers.
611 {
612 MutexLocker mu(Threads_lock);
613 Threads::add(main_thread);
614 }
615
616 status = init_globals2();
617 if (status != JNI_OK) {
618 Threads::remove(main_thread, false);
619 // It is possible that we managed to fully initialize Universe but have then
620 // failed by throwing an exception. In that case our caller JNI_CreateJavaVM
621 // will want to report it, so we can't delete the main thread.
622 if (!main_thread->has_pending_exception()) {
623 main_thread->smr_delete();
624 }
625 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
626 return status;
627 }
628
629 ObjectMonitor::Initialize2();
630
631 JFR_ONLY(Jfr::on_create_vm_1();)
632
633 // Should be done after the heap is fully created
634 main_thread->cache_global_variables();
635
636 // Any JVMTI raw monitors entered in onload will transition into
637 // real raw monitor. VM is setup enough here for raw monitor enter.
638 JvmtiExport::transition_pending_onload_raw_monitors();
639
640 // Create the VMThread
641 { TraceTime timer("Start VMThread", TRACETIME_LOG(Info, startuptime));
642
643 VMThread::create();
644 VMThread* vmthread = VMThread::vm_thread();
645
646 if (!os::create_thread(vmthread, os::vm_thread)) {
647 vm_exit_during_initialization("Cannot create VM thread. "
648 "Out of system resources.");
649 }
650
651 // Wait for the VM thread to become ready, and VMThread::run to initialize
652 // Monitors can have spurious returns, must always check another state flag
653 {
654 MonitorLocker ml(Notify_lock);
655 os::start_thread(vmthread);
656 while (!vmthread->is_running()) {
657 ml.wait();
658 }
659 }
660 }
661
662 assert(Universe::is_fully_initialized(), "not initialized");
663 if (VerifyDuringStartup) {
664 // Make sure we're starting with a clean slate.
665 VM_Verify verify_op;
666 VMThread::execute(&verify_op);
667 }
668
669 // We need this to update the java.vm.info property in case any flags used
670 // to initially define it have been changed. This is needed for both CDS
671 // since UseSharedSpaces may be changed after java.vm.info
672 // is initially computed. See Abstract_VM_Version::vm_info_string().
673 // This update must happen before we initialize the java classes, but
674 // after any initialization logic that might modify the flags.
675 Arguments::update_vm_info_property(VM_Version::vm_info_string());
676
677 JavaThread* THREAD = JavaThread::current(); // For exception macros.
678 HandleMark hm(THREAD);
679
680 // Always call even when there are not JVMTI environments yet, since environments
681 // may be attached late and JVMTI must track phases of VM execution
682 JvmtiExport::enter_early_start_phase();
683
684 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
685 JvmtiExport::post_early_vm_start();
686
687 // Launch -Xrun agents early if EagerXrunInit is set
688 if (EagerXrunInit) {
689 JvmtiAgentList::load_xrun_agents();
690 }
691
692 initialize_java_lang_classes(main_thread, CHECK_JNI_ERR);
693
694 quicken_jni_functions();
695
696 // No more stub generation allowed after that point.
697 StubCodeDesc::freeze();
698
699 // Set flag that basic initialization has completed. Used by exceptions and various
700 // debug stuff, that does not work until all basic classes have been initialized.
701 set_init_completed();
702
703 LogConfiguration::post_initialize();
704 Metaspace::post_initialize();
705 MutexLockerImpl::post_initialize();
706
707 HOTSPOT_VM_INIT_END();
708
709 // record VM initialization completion time
710 #if INCLUDE_MANAGEMENT
711 Management::record_vm_init_completed();
712 #endif // INCLUDE_MANAGEMENT
713
714 log_info(os)("Initialized VM with process ID %d", os::current_process_id());
715
716 if (!FLAG_IS_DEFAULT(CreateCoredumpOnCrash) && CreateCoredumpOnCrash) {
717 char buffer[2*JVM_MAXPATHLEN];
718 os::check_core_dump_prerequisites(buffer, sizeof(buffer), true);
719 }
720
721 // Signal Dispatcher needs to be started before VMInit event is posted
722 os::initialize_jdk_signal_support(CHECK_JNI_ERR);
723
724 // Start Attach Listener if +StartAttachListener or it can't be started lazily
725 if (!DisableAttachMechanism) {
726 AttachListener::vm_start();
727 if (StartAttachListener || AttachListener::init_at_startup()) {
728 AttachListener::init();
729 }
730 }
731
732 // Launch -Xrun agents if EagerXrunInit is not set.
733 if (!EagerXrunInit) {
734 JvmtiAgentList::load_xrun_agents();
735 }
736
737 Arena::start_chunk_pool_cleaner_task();
738
739 // Start the service thread
740 // The service thread enqueues JVMTI deferred events and does various hashtable
741 // and other cleanups. Needs to start before the compilers start posting events.
742 ServiceThread::initialize();
743
744 // Start the monitor deflation thread:
745 MonitorDeflationThread::initialize();
746
747 // initialize compiler(s)
748 #if defined(COMPILER1) || COMPILER2_OR_JVMCI
749 bool init_compilation = true;
750 #if INCLUDE_JVMCI
751 bool force_JVMCI_initialization = false;
752 if (EnableJVMCI) {
753 // Initialize JVMCI eagerly when it is explicitly requested.
754 // Or when JVMCILibDumpJNIConfig or JVMCIPrintProperties is enabled.
755 force_JVMCI_initialization = EagerJVMCI || JVMCIPrintProperties || JVMCILibDumpJNIConfig;
756 if (!force_JVMCI_initialization && UseJVMCICompiler && !UseJVMCINativeLibrary && (!UseInterpreter || !BackgroundCompilation)) {
757 // Force initialization of jarjvmci otherwise requests for blocking
758 // compilations will not actually block until jarjvmci is initialized.
759 force_JVMCI_initialization = true;
760 }
761 if (JVMCIPrintProperties || JVMCILibDumpJNIConfig) {
762 // Both JVMCILibDumpJNIConfig and JVMCIPrintProperties exit the VM
763 // so compilation should be disabled. This prevents dumping or
764 // printing from happening more than once.
765 init_compilation = false;
766 }
767 }
768 #endif
769 if (init_compilation) {
770 CompileBroker::compilation_init(CHECK_JNI_ERR);
771 }
772 #endif
773
774 if (CDSConfig::is_using_aot_linked_classes()) {
775 SystemDictionary::restore_archived_method_handle_intrinsics();
776 AOTLinkedClassBulkLoader::finish_loading_javabase_classes(CHECK_JNI_ERR);
777 }
778
779 // Start string deduplication thread if requested.
780 if (StringDedup::is_enabled()) {
781 StringDedup::start();
782 }
783
784 // Pre-initialize some JSR292 core classes to avoid deadlock during class loading.
785 // It is done after compilers are initialized, because otherwise compilations of
786 // signature polymorphic MH intrinsics can be missed
787 // (see SystemDictionary::find_method_handle_intrinsic).
788 initialize_jsr292_core_classes(CHECK_JNI_ERR);
789
790 // This will initialize the module system. Only java.base classes can be
791 // loaded until phase 2 completes
792 call_initPhase2(CHECK_JNI_ERR);
793
794 if (CDSConfig::is_using_aot_linked_classes()) {
795 AOTLinkedClassBulkLoader::load_non_javabase_classes(THREAD);
796 }
797 #ifndef PRODUCT
798 HeapShared::initialize_test_class_from_archive(THREAD);
799 #endif
800
801 JFR_ONLY(Jfr::on_create_vm_2();)
802
803 // Always call even when there are not JVMTI environments yet, since environments
804 // may be attached late and JVMTI must track phases of VM execution
805 JvmtiExport::enter_start_phase();
806
807 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
808 JvmtiExport::post_vm_start();
809
810 // Final system initialization including security manager and system class loader
811 call_initPhase3(CHECK_JNI_ERR);
812
813 // cache the system and platform class loaders
814 SystemDictionary::compute_java_loaders(CHECK_JNI_ERR);
815
816 // Initiate replay training processing once preloading is over.
817 CompileBroker::init_training_replay();
818
819 AOTLinkedClassBulkLoader::replay_training_at_init_for_preloaded_classes(CHECK_JNI_ERR);
820
821 if (Continuations::enabled()) {
822 // Initialize Continuation class now so that failure to create enterSpecial/doYield
823 // special nmethods due to limited CodeCache size can be treated as a fatal error at
824 // startup with the proper message that CodeCache size is too small.
825 initialize_class(vmSymbols::jdk_internal_vm_Continuation(), CHECK_JNI_ERR);
826 }
827
828 if (NativeHeapTrimmer::enabled()) {
829 NativeHeapTrimmer::initialize();
830 }
831
832 // Always call even when there are not JVMTI environments yet, since environments
833 // may be attached late and JVMTI must track phases of VM execution
834 JvmtiExport::enter_live_phase();
835
836 // Make perfmemory accessible
837 PerfMemory::set_accessible(true);
838
839 // Notify JVMTI agents that VM initialization is complete - nop if no agents.
840 JvmtiExport::post_vm_initialized();
841
842 #if INCLUDE_JVMCI
843 if (force_JVMCI_initialization) {
844 JVMCI::initialize_compiler_in_create_vm(CHECK_JNI_ERR);
845 }
846 #endif
847
848 JFR_ONLY(Jfr::on_create_vm_3();)
849
850 #if INCLUDE_MANAGEMENT
851 bool start_agent = true;
852 #if INCLUDE_CDS
853 start_agent = !CDSConfig::is_dumping_final_static_archive();
854 if (!start_agent) {
855 log_info(aot)("Not starting management agent during creation of AOT cache.");
856 }
857 #endif // INCLUDE_CDS
858 if (start_agent) {
859 Management::initialize(THREAD);
860
861 if (HAS_PENDING_EXCEPTION) {
862 // management agent fails to start possibly due to
863 // configuration problem and is responsible for printing
864 // stack trace if appropriate. Simply exit VM.
865 vm_exit(1);
866 }
867 }
868 #endif // INCLUDE_MANAGEMENT
869
870 if (UsePerfData) PerfDataManager::create_misc_perfdata();
871 if (CheckJNICalls) JniPeriodicChecker::engage();
872
873 call_postVMInitHook(THREAD);
874 // The Java side of PostVMInitHook.run must deal with all
875 // exceptions and provide means of diagnosis.
876 if (HAS_PENDING_EXCEPTION) {
877 CLEAR_PENDING_EXCEPTION;
878 }
879
880 // Let WatcherThread run all registered periodic tasks now.
881 // NOTE: All PeriodicTasks should be registered by now. If they
882 // aren't, late joiners might appear to start slowly (we might
883 // take a while to process their first tick).
884 WatcherThread::run_all_tasks();
885
886 create_vm_timer.end();
887 #ifdef ASSERT
888 _vm_complete = true;
889 #endif
890
891 if (CDSConfig::is_dumping_classic_static_archive()) {
892 // Classic -Xshare:dump, aka "old workflow"
893 MetaspaceShared::preload_and_dump(CHECK_JNI_ERR);
894 } else if (CDSConfig::is_dumping_final_static_archive()) {
895 tty->print_cr("Reading AOTConfiguration %s and writing AOTCache %s", AOTConfiguration, AOTCache);
896 MetaspaceShared::preload_and_dump(CHECK_JNI_ERR);
897 }
898
899 if (log_is_enabled(Info, perf, class, link)) {
900 LogStreamHandle(Info, perf, class, link) log;
901 log.print_cr("At VM initialization completion:");
902 ClassLoader::print_counters(&log);
903 }
904
905 return JNI_OK;
906 }
907
908 // Threads::destroy_vm() is normally called from jni_DestroyJavaVM() when
909 // the program falls off the end of main(). Another VM exit path is through
910 // vm_exit(), when the program calls System.exit() to return a value, or when
911 // there is a serious error in VM.
912 // These two separate shutdown paths are not exactly the same, but they share
913 // Shutdown.shutdown() at Java level and before_exit() and VM_Exit op at VM level.
914 //
915 // Shutdown sequence:
916 // + Shutdown native memory tracking if it is on
917 // + Wait until we are the last non-daemon thread to execute
918 // <-- every thing is still working at this moment -->
919 // + Call java.lang.Shutdown.shutdown(), which will invoke Java level
920 // shutdown hooks
921 // + Call before_exit(), prepare for VM exit
922 // > run VM level shutdown hooks (they are registered through JVM_OnExit(),
923 // currently the only user of this mechanism is File.deleteOnExit())
924 // > stop watcher thread,
925 // post thread end and vm death events to JVMTI,
926 // stop signal thread
927 // + Call JavaThread::exit(), it will:
928 // > release JNI handle blocks, remove stack guard pages
929 // > remove this thread from Threads list
930 // <-- no more Java code from this thread after this point -->
931 // + Stop VM thread, it will bring the remaining VM to a safepoint and stop
932 // the compiler threads at safepoint
933 // <-- do not use anything that could get blocked by Safepoint -->
934 // + Disable tracing at JNI/JVM barriers
935 // + Set _vm_exited flag for threads that are still running native code
936 // + Call exit_globals()
937 // > deletes tty
938 // > deletes PerfMemory resources
939 // + Delete this thread
940 // + Return to caller
941
942 void Threads::destroy_vm() {
943 JavaThread* thread = JavaThread::current();
944
945 #ifdef ASSERT
946 _vm_complete = false;
947 #endif
948 // Wait until we are the last non-daemon thread to execute, or
949 // if we are a daemon then wait until the last non-daemon thread has
950 // executed.
951 bool daemon = java_lang_Thread::is_daemon(thread->threadObj());
952 int expected = daemon ? 0 : 1;
953 {
954 MonitorLocker nu(Threads_lock);
955 while (Threads::number_of_non_daemon_threads() > expected)
956 // This wait should make safepoint checks, wait without a timeout.
957 nu.wait(0);
958 }
959
960 EventShutdown e;
961 if (e.should_commit()) {
962 e.set_reason("No remaining non-daemon Java threads");
963 e.commit();
964 }
965
966 // Hang forever on exit if we are reporting an error.
967 if (ShowMessageBoxOnError && VMError::is_error_reported()) {
968 os::infinite_sleep();
969 }
970 os::wait_for_keypress_at_exit();
971
972 // run Java level shutdown hooks
973 thread->invoke_shutdown_hooks();
974
975 before_exit(thread);
976
977 thread->exit(true);
978
979 // We are no longer on the main thread list but could still be in a
980 // secondary list where another thread may try to interact with us.
981 // So wait until all such interactions are complete before we bring
982 // the VM to the termination safepoint. Normally this would be done
983 // using thread->smr_delete() below where we delete the thread, but
984 // we can't call that after the termination safepoint is active as
985 // we will deadlock on the Threads_lock. Once all interactions are
986 // complete it is safe to directly delete the thread at any time.
987 ThreadsSMRSupport::wait_until_not_protected(thread);
988
989 // Stop VM thread.
990 {
991 // 4945125 The vm thread comes to a safepoint during exit.
992 // GC vm_operations can get caught at the safepoint, and the
993 // heap is unparseable if they are caught. Grab the Heap_lock
994 // to prevent this. The GC vm_operations will not be able to
995 // queue until after the vm thread is dead. After this point,
996 // we'll never emerge out of the safepoint before the VM exits.
997 // Assert that the thread is terminated so that acquiring the
998 // Heap_lock doesn't cause the terminated thread to participate in
999 // the safepoint protocol.
1000
1001 assert(thread->is_terminated(), "must be terminated here");
1002 MutexLocker ml(Heap_lock);
1003
1004 VMThread::wait_for_vm_thread_exit();
1005 assert(SafepointSynchronize::is_at_safepoint(), "VM thread should exit at Safepoint");
1006 VMThread::destroy();
1007 }
1008
1009 // Now, all Java threads are gone except daemon threads. Daemon threads
1010 // running Java code or in VM are stopped by the Safepoint. However,
1011 // daemon threads executing native code are still running. But they
1012 // will be stopped at native=>Java/VM barriers. Note that we can't
1013 // simply kill or suspend them, as it is inherently deadlock-prone.
1014
1015 VM_Exit::set_vm_exited();
1016
1017 // Clean up ideal graph printers after the VMThread has started
1018 // the final safepoint which will block all the Compiler threads.
1019 // Note that this Thread has already logically exited so the
1020 // clean_up() function's use of a JavaThreadIteratorWithHandle
1021 // would be a problem except set_vm_exited() has remembered the
1022 // shutdown thread which is granted a policy exception.
1023 #if defined(COMPILER2) && !defined(PRODUCT)
1024 IdealGraphPrinter::clean_up();
1025 #endif
1026
1027 notify_vm_shutdown();
1028
1029 // exit_globals() will delete tty
1030 exit_globals();
1031
1032 // Deleting the shutdown thread here is safe. See comment on
1033 // wait_until_not_protected() above.
1034 delete thread;
1035
1036 #if INCLUDE_JVMCI
1037 if (JVMCICounterSize > 0) {
1038 FREE_C_HEAP_ARRAY(jlong, JavaThread::_jvmci_old_thread_counters);
1039 }
1040 #endif
1041
1042 LogConfiguration::finalize();
1043 }
1044
1045
1046 jboolean Threads::is_supported_jni_version_including_1_1(jint version) {
1047 if (version == JNI_VERSION_1_1) return JNI_TRUE;
1048 return is_supported_jni_version(version);
1049 }
1050
1051
1052 jboolean Threads::is_supported_jni_version(jint version) {
1053 if (version == JNI_VERSION_1_2) return JNI_TRUE;
1054 if (version == JNI_VERSION_1_4) return JNI_TRUE;
1055 if (version == JNI_VERSION_1_6) return JNI_TRUE;
1056 if (version == JNI_VERSION_1_8) return JNI_TRUE;
1057 if (version == JNI_VERSION_9) return JNI_TRUE;
1058 if (version == JNI_VERSION_10) return JNI_TRUE;
1059 if (version == JNI_VERSION_19) return JNI_TRUE;
1060 if (version == JNI_VERSION_20) return JNI_TRUE;
1061 if (version == JNI_VERSION_21) return JNI_TRUE;
1062 if (version == JNI_VERSION_24) return JNI_TRUE;
1063 return JNI_FALSE;
1064 }
1065
1066 void Threads::add(JavaThread* p, bool force_daemon) {
1067 // The threads lock must be owned at this point
1068 assert(Threads_lock->owned_by_self(), "must have threads lock");
1069 assert(p->monitor_owner_id() != 0, "should be set");
1070
1071 BarrierSet::barrier_set()->on_thread_attach(p);
1072
1073 // Once a JavaThread is added to the Threads list, smr_delete() has
1074 // to be used to delete it. Otherwise we can just delete it directly.
1075 p->set_on_thread_list();
1076
1077 _number_of_threads++;
1078 oop threadObj = p->threadObj();
1079 bool daemon = true;
1080 // Bootstrapping problem: threadObj can be null for initial
1081 // JavaThread (or for threads attached via JNI)
1082 if (!force_daemon &&
1083 (threadObj == nullptr || !java_lang_Thread::is_daemon(threadObj))) {
1084 _number_of_non_daemon_threads++;
1085 daemon = false;
1086 }
1087
1088 ThreadService::add_thread(p, daemon);
1089
1090 // Maintain fast thread list
1091 ThreadsSMRSupport::add_thread(p);
1092
1093 // Increase the ObjectMonitor ceiling for the new thread.
1094 ObjectSynchronizer::inc_in_use_list_ceiling();
1095
1096 // Possible GC point.
1097 Events::log(Thread::current(), "Thread added: " INTPTR_FORMAT, p2i(p));
1098
1099 // Make new thread known to active EscapeBarrier
1100 EscapeBarrier::thread_added(p);
1101 }
1102
1103 void Threads::remove(JavaThread* p, bool is_daemon) {
1104 // Extra scope needed for Thread_lock, so we can check
1105 // that we do not remove thread without safepoint code notice
1106 {
1107 ConditionalMutexLocker throttle_ml(ThreadsLockThrottle_lock, UseThreadsLockThrottleLock);
1108 MonitorLocker ml(Threads_lock);
1109
1110 if (ThreadIdTable::is_initialized()) {
1111 // This cleanup must be done before the current thread's GC barrier
1112 // is detached since we need to touch the threadObj oop.
1113 jlong tid = SharedRuntime::get_java_tid(p);
1114 ThreadIdTable::remove_thread(tid);
1115 }
1116
1117 // BarrierSet state must be destroyed after the last thread transition
1118 // before the thread terminates. Thread transitions result in calls to
1119 // StackWatermarkSet::on_safepoint(), which performs GC processing,
1120 // requiring the GC state to be alive.
1121 BarrierSet::barrier_set()->on_thread_detach(p);
1122 if (p->is_exiting()) {
1123 // If we got here via JavaThread::exit(), then we remember that the
1124 // thread's GC barrier has been detached. We don't do this when we get
1125 // here from another path, e.g., cleanup_failed_attach_current_thread().
1126 p->set_terminated(JavaThread::_thread_gc_barrier_detached);
1127 }
1128
1129 assert(ThreadsSMRSupport::get_java_thread_list()->includes(p), "p must be present");
1130
1131 // Maintain fast thread list
1132 ThreadsSMRSupport::remove_thread(p);
1133
1134 _number_of_threads--;
1135 if (!is_daemon) {
1136 _number_of_non_daemon_threads--;
1137
1138 // If this is the last non-daemon thread then we need to do
1139 // a notify on the Threads_lock so a thread waiting
1140 // on destroy_vm will wake up. But that thread could be a daemon
1141 // or non-daemon, so we notify for both the 0 and 1 case.
1142 if (number_of_non_daemon_threads() <= 1) {
1143 ml.notify_all();
1144 }
1145 }
1146 ThreadService::remove_thread(p, is_daemon);
1147
1148 // Make sure that safepoint code disregard this thread. This is needed since
1149 // the thread might mess around with locks after this point. This can cause it
1150 // to do callbacks into the safepoint code. However, the safepoint code is not aware
1151 // of this thread since it is removed from the queue.
1152 p->set_terminated(JavaThread::_thread_terminated);
1153
1154 // Notify threads waiting in EscapeBarriers
1155 EscapeBarrier::thread_removed(p);
1156 } // unlock Threads_lock and ThreadsLockThrottle_lock
1157
1158 // Reduce the ObjectMonitor ceiling for the exiting thread.
1159 ObjectSynchronizer::dec_in_use_list_ceiling();
1160
1161 // Since Events::log uses a lock, we grab it outside the Threads_lock
1162 Events::log(Thread::current(), "Thread exited: " INTPTR_FORMAT, p2i(p));
1163 }
1164
1165 // Operations on the Threads list for GC. These are not explicitly locked,
1166 // but the garbage collector must provide a safe context for them to run.
1167 // In particular, these things should never be called when the Threads_lock
1168 // is held by some other thread. (Note: the Safepoint abstraction also
1169 // uses the Threads_lock to guarantee this property. It also makes sure that
1170 // all threads gets blocked when exiting or starting).
1171
1172 void Threads::oops_do(OopClosure* f, NMethodClosure* cf) {
1173 ALL_JAVA_THREADS(p) {
1174 p->oops_do(f, cf);
1175 }
1176 VMThread::vm_thread()->oops_do(f, cf);
1177 }
1178
1179 void Threads::change_thread_claim_token() {
1180 if (++_thread_claim_token == 0) {
1181 // On overflow of the token counter, there is a risk of future
1182 // collisions between a new global token value and a stale token
1183 // for a thread, because not all iterations visit all threads.
1184 // (Though it's pretty much a theoretical concern for non-trivial
1185 // token counter sizes.) To deal with the possibility, reset all
1186 // the thread tokens to zero on global token overflow.
1187 struct ResetClaims : public ThreadClosure {
1188 virtual void do_thread(Thread* t) {
1189 t->claim_threads_do(false, 0);
1190 }
1191 } reset_claims;
1192 Threads::threads_do(&reset_claims);
1193 // On overflow, update the global token to non-zero, to
1194 // avoid the special "never claimed" initial thread value.
1195 _thread_claim_token = 1;
1196 }
1197 }
1198
1199 #ifdef ASSERT
1200 static void assert_thread_claimed(const char* kind, Thread* t, uintx expected) {
1201 const uintx token = t->threads_do_token();
1202 assert(token == expected,
1203 "%s " PTR_FORMAT " has incorrect value %zu != %zu",
1204 kind, p2i(t), token, expected);
1205 }
1206
1207 void Threads::assert_all_threads_claimed() {
1208 ALL_JAVA_THREADS(p) {
1209 assert_thread_claimed("JavaThread", p, _thread_claim_token);
1210 }
1211
1212 struct NJTClaimedVerifierClosure : public ThreadClosure {
1213 uintx _thread_claim_token;
1214
1215 NJTClaimedVerifierClosure(uintx thread_claim_token) : ThreadClosure(), _thread_claim_token(thread_claim_token) { }
1216
1217 virtual void do_thread(Thread* thread) override {
1218 assert_thread_claimed("Non-JavaThread", VMThread::vm_thread(), _thread_claim_token);
1219 }
1220 } tc(_thread_claim_token);
1221
1222 non_java_threads_do(&tc);
1223 }
1224 #endif // ASSERT
1225
1226 class ParallelOopsDoThreadClosure : public ThreadClosure {
1227 private:
1228 OopClosure* _f;
1229 NMethodClosure* _cf;
1230 public:
1231 ParallelOopsDoThreadClosure(OopClosure* f, NMethodClosure* cf) : _f(f), _cf(cf) {}
1232 void do_thread(Thread* t) {
1233 t->oops_do(_f, _cf);
1234 }
1235 };
1236
1237 void Threads::possibly_parallel_oops_do(bool is_par, OopClosure* f, NMethodClosure* cf) {
1238 ParallelOopsDoThreadClosure tc(f, cf);
1239 possibly_parallel_threads_do(is_par, &tc);
1240 }
1241
1242 void Threads::metadata_do(MetadataClosure* f) {
1243 ALL_JAVA_THREADS(p) {
1244 p->metadata_do(f);
1245 }
1246 }
1247
1248 class ThreadHandlesClosure : public ThreadClosure {
1249 void (*_f)(Metadata*);
1250 public:
1251 ThreadHandlesClosure(void f(Metadata*)) : _f(f) {}
1252 virtual void do_thread(Thread* thread) {
1253 thread->metadata_handles_do(_f);
1254 }
1255 };
1256
1257 void Threads::metadata_handles_do(void f(Metadata*)) {
1258 // Only walk the Handles in Thread.
1259 ThreadHandlesClosure handles_closure(f);
1260 threads_do(&handles_closure);
1261 }
1262
1263 #if INCLUDE_JVMTI
1264 // Get Java threads that are waiting to enter or re-enter the specified monitor.
1265 // Java threads that are executing mounted virtual threads are not included.
1266 GrowableArray<JavaThread*>* Threads::get_pending_threads(ThreadsList * t_list,
1267 int count,
1268 address monitor) {
1269 assert(Thread::current()->is_VM_thread(), "Must be the VM thread");
1270 GrowableArray<JavaThread*>* result = new GrowableArray<JavaThread*>(count);
1271
1272 int i = 0;
1273 for (JavaThread* p : *t_list) {
1274 if (!p->can_call_java()) continue;
1275
1276 oop thread_oop = JvmtiEnvBase::get_vthread_or_thread_oop(p);
1277 if (thread_oop->is_a(vmClasses::BaseVirtualThread_klass())) {
1278 continue;
1279 }
1280 // The first stage of async deflation does not affect any field
1281 // used by this comparison so the ObjectMonitor* is usable here.
1282 address pending = (address)p->current_pending_monitor();
1283 address waiting = (address)p->current_waiting_monitor();
1284 // do not include virtual threads to the list
1285 jint state = JvmtiEnvBase::get_thread_state(thread_oop, p);
1286 if (pending == monitor || (waiting == monitor &&
1287 (state & JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER))
1288 ) { // found a match
1289 if (i < count) result->append(p); // save the first count matches
1290 i++;
1291 }
1292 }
1293
1294 return result;
1295 }
1296 #endif // INCLUDE_JVMTI
1297
1298 JavaThread *Threads::owning_thread_from_stacklock(ThreadsList * t_list, address basicLock) {
1299 assert(LockingMode == LM_LEGACY, "Not with new lightweight locking");
1300
1301 JavaThread* the_owner = nullptr;
1302 for (JavaThread* q : *t_list) {
1303 if (q->is_lock_owned(basicLock)) {
1304 the_owner = q;
1305 break;
1306 }
1307 }
1308 return the_owner;
1309 }
1310
1311 JavaThread* Threads::owning_thread_from_object(ThreadsList * t_list, oop obj) {
1312 assert(LockingMode == LM_LIGHTWEIGHT, "Only with new lightweight locking");
1313 for (JavaThread* q : *t_list) {
1314 // Need to start processing before accessing oops in the thread.
1315 StackWatermark* watermark = StackWatermarkSet::get(q, StackWatermarkKind::gc);
1316 if (watermark != nullptr) {
1317 watermark->start_processing();
1318 }
1319
1320 if (q->lock_stack().contains(obj)) {
1321 return q;
1322 }
1323 }
1324 return nullptr;
1325 }
1326
1327 JavaThread* Threads::owning_thread_from_monitor(ThreadsList* t_list, ObjectMonitor* monitor) {
1328 if (monitor->has_anonymous_owner()) {
1329 if (LockingMode == LM_LIGHTWEIGHT) {
1330 return owning_thread_from_object(t_list, monitor->object());
1331 } else {
1332 assert(LockingMode == LM_LEGACY, "invariant");
1333 return owning_thread_from_stacklock(t_list, (address)monitor->stack_locker());
1334 }
1335 } else {
1336 JavaThread* the_owner = nullptr;
1337 for (JavaThread* q : *t_list) {
1338 if (monitor->has_owner(q)) {
1339 the_owner = q;
1340 break;
1341 }
1342 }
1343 return the_owner;
1344 }
1345 }
1346
1347 class PrintOnClosure : public ThreadClosure {
1348 private:
1349 outputStream* _st;
1350
1351 public:
1352 PrintOnClosure(outputStream* st) :
1353 _st(st) {}
1354
1355 virtual void do_thread(Thread* thread) {
1356 if (thread != nullptr) {
1357 thread->print_on(_st);
1358 _st->cr();
1359 }
1360 }
1361 };
1362
1363 // Threads::print_on() is called at safepoint by VM_PrintThreads operation.
1364 void Threads::print_on(outputStream* st, bool print_stacks,
1365 bool internal_format, bool print_concurrent_locks,
1366 bool print_extended_info) {
1367 char buf[32];
1368 st->print_raw_cr(os::local_time_string(buf, sizeof(buf)));
1369
1370 st->print_cr("Full thread dump %s (%s %s):",
1371 VM_Version::vm_name(),
1372 VM_Version::vm_release(),
1373 VM_Version::vm_info_string());
1374 st->cr();
1375
1376 #if INCLUDE_SERVICES
1377 // Dump concurrent locks
1378 ConcurrentLocksDump concurrent_locks;
1379 if (print_concurrent_locks) {
1380 concurrent_locks.dump_at_safepoint();
1381 }
1382 #endif // INCLUDE_SERVICES
1383
1384 ThreadsSMRSupport::print_info_on(st);
1385 st->cr();
1386
1387 ALL_JAVA_THREADS(p) {
1388 ResourceMark rm;
1389 p->print_on(st, print_extended_info);
1390 if (print_stacks) {
1391 if (internal_format) {
1392 p->trace_stack();
1393 } else {
1394 p->print_stack_on(st);
1395 if (p->is_vthread_mounted()) {
1396 st->print_cr(" Mounted virtual thread #" INT64_FORMAT, java_lang_Thread::thread_id(p->vthread()));
1397 p->print_vthread_stack_on(st);
1398 }
1399 }
1400 }
1401 st->cr();
1402 #if INCLUDE_SERVICES
1403 if (print_concurrent_locks) {
1404 concurrent_locks.print_locks_on(p, st);
1405 }
1406 #endif // INCLUDE_SERVICES
1407 }
1408
1409 PrintOnClosure cl(st);
1410 non_java_threads_do(&cl);
1411
1412 st->flush();
1413 }
1414
1415 void Threads::print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
1416 int buflen, bool* found_current) {
1417 if (this_thread != nullptr) {
1418 bool is_current = (current == this_thread);
1419 *found_current = *found_current || is_current;
1420 st->print("%s", is_current ? "=>" : " ");
1421
1422 st->print(PTR_FORMAT, p2i(this_thread));
1423 st->print(" ");
1424 this_thread->print_on_error(st, buf, buflen);
1425 st->cr();
1426 }
1427 }
1428
1429 class PrintOnErrorClosure : public ThreadClosure {
1430 outputStream* _st;
1431 Thread* _current;
1432 char* _buf;
1433 int _buflen;
1434 bool* _found_current;
1435 unsigned _num_printed;
1436 public:
1437 PrintOnErrorClosure(outputStream* st, Thread* current, char* buf,
1438 int buflen, bool* found_current) :
1439 _st(st), _current(current), _buf(buf), _buflen(buflen), _found_current(found_current),
1440 _num_printed(0) {}
1441
1442 virtual void do_thread(Thread* thread) {
1443 _num_printed++;
1444 Threads::print_on_error(thread, _st, _current, _buf, _buflen, _found_current);
1445 }
1446
1447 unsigned num_printed() const { return _num_printed; }
1448 };
1449
1450 // Threads::print_on_error() is called by fatal error handler. It's possible
1451 // that VM is not at safepoint and/or current thread is inside signal handler.
1452 // Don't print stack trace, as the stack may not be walkable. Don't allocate
1453 // memory (even in resource area), it might deadlock the error handler.
1454 void Threads::print_on_error(outputStream* st, Thread* current, char* buf,
1455 int buflen) {
1456 ThreadsSMRSupport::print_info_on(st);
1457 st->cr();
1458
1459 bool found_current = false;
1460 st->print_cr("Java Threads: ( => current thread )");
1461 unsigned num_java = 0;
1462 ALL_JAVA_THREADS(thread) {
1463 print_on_error(thread, st, current, buf, buflen, &found_current);
1464 num_java++;
1465 }
1466 st->print_cr("Total: %u", num_java);
1467 st->cr();
1468
1469 st->print_cr("Other Threads:");
1470 unsigned num_other = ((VMThread::vm_thread() != nullptr) ? 1 : 0) +
1471 ((WatcherThread::watcher_thread() != nullptr) ? 1 : 0) +
1472 ((AsyncLogWriter::instance() != nullptr) ? 1 : 0);
1473 print_on_error(VMThread::vm_thread(), st, current, buf, buflen, &found_current);
1474 print_on_error(WatcherThread::watcher_thread(), st, current, buf, buflen, &found_current);
1475 print_on_error(AsyncLogWriter::instance(), st, current, buf, buflen, &found_current);
1476
1477 if (Universe::heap() != nullptr) {
1478 PrintOnErrorClosure print_closure(st, current, buf, buflen, &found_current);
1479 Universe::heap()->gc_threads_do(&print_closure);
1480 num_other += print_closure.num_printed();
1481 }
1482
1483 if (!found_current) {
1484 st->cr();
1485 st->print("=>" PTR_FORMAT " (exited) ", p2i(current));
1486 current->print_on_error(st, buf, buflen);
1487 num_other++;
1488 st->cr();
1489 }
1490 st->print_cr("Total: %u", num_other);
1491 st->cr();
1492
1493 st->print_cr("Threads with active compile tasks:");
1494 unsigned num = print_threads_compiling(st, buf, buflen);
1495 st->print_cr("Total: %u", num);
1496 }
1497
1498 unsigned Threads::print_threads_compiling(outputStream* st, char* buf, int buflen, bool short_form) {
1499 unsigned num = 0;
1500 ALL_JAVA_THREADS(thread) {
1501 if (thread->is_Compiler_thread()) {
1502 CompilerThread* ct = (CompilerThread*) thread;
1503
1504 // Keep task in local variable for null check.
1505 // ct->_task might be set to null by concurring compiler thread
1506 // because it completed the compilation. The task is never freed,
1507 // though, just returned to a free list.
1508 CompileTask* task = ct->task();
1509 if (task != nullptr) {
1510 thread->print_name_on_error(st, buf, buflen);
1511 st->print(" ");
1512 task->print(st, nullptr, short_form, true);
1513 num++;
1514 }
1515 }
1516 }
1517 return num;
1518 }
1519
1520 void Threads::verify() {
1521 ALL_JAVA_THREADS(p) {
1522 p->verify();
1523 }
1524 VMThread* thread = VMThread::vm_thread();
1525 if (thread != nullptr) thread->verify();
1526 }