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/safepoint.hpp"
86 #include "runtime/safepointMechanism.inline.hpp"
87 #include "runtime/safepointVerifiers.hpp"
88 #include "runtime/serviceThread.hpp"
89 #include "runtime/sharedRuntime.hpp"
90 #include "runtime/stackWatermarkSet.inline.hpp"
91 #include "runtime/statSampler.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::java_lang_ArrayIndexOutOfBoundsException(), CHECK);
409 initialize_class(vmSymbols::java_lang_StackOverflowError(), CHECK);
410 initialize_class(vmSymbols::java_lang_IllegalMonitorStateException(), CHECK);
411 initialize_class(vmSymbols::java_lang_IdentityException(), 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 jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) {
430 extern void JDK_Version_init();
431
432 // Preinitialize version info.
433 VM_Version::early_initialize();
434
435 // Check version
436 if (!is_supported_jni_version(args->version)) return JNI_EVERSION;
437
438 // Initialize library-based TLS
439 ThreadLocalStorage::init();
440
441 // Initialize the output stream module
442 ostream_init();
443
444 // Process java launcher properties.
445 Arguments::process_sun_java_launcher_properties(args);
446
447 // Initialize the os module
448 os::init();
449
450 MACOS_AARCH64_ONLY(os::current_thread_enable_wx(WXWrite));
451
452 // Record VM creation timing statistics
453 TraceVmCreationTime create_vm_timer;
454 create_vm_timer.start();
455
456 // Initialize system properties.
457 Arguments::init_system_properties();
458
459 // So that JDK version can be used as a discriminator when parsing arguments
460 JDK_Version_init();
461
462 // Update/Initialize System properties after JDK version number is known
463 Arguments::init_version_specific_system_properties();
464
465 // Make sure to initialize log configuration *before* parsing arguments
466 LogConfiguration::initialize(create_vm_timer.begin_time());
467
468 // Parse arguments
469 // Note: this internally calls os::init_container_support()
470 jint parse_result = Arguments::parse(args);
471 if (parse_result != JNI_OK) return parse_result;
472
473 // Initialize NMT right after argument parsing to keep the pre-NMT-init window small.
474 MemTracker::initialize();
475
476 os::init_before_ergo();
477
478 jint ergo_result = Arguments::apply_ergo();
479 if (ergo_result != JNI_OK) return ergo_result;
480
481 // Final check of all ranges after ergonomics which may change values.
482 if (!JVMFlagLimit::check_all_ranges()) {
483 return JNI_EINVAL;
484 }
485
486 // Final check of all 'AfterErgo' constraints after ergonomics which may change values.
487 bool constraint_result = JVMFlagLimit::check_all_constraints(JVMFlagConstraintPhase::AfterErgo);
488 if (!constraint_result) {
489 return JNI_EINVAL;
490 }
491
492 if (PauseAtStartup) {
493 os::pause();
494 }
495
496 HOTSPOT_VM_INIT_BEGIN();
497
498 // Timing (must come after argument parsing)
499 TraceTime timer("Create VM", TRACETIME_LOG(Info, startuptime));
500
501 // Initialize the os module after parsing the args
502 jint os_init_2_result = os::init_2();
503 if (os_init_2_result != JNI_OK) return os_init_2_result;
504
505 #ifdef CAN_SHOW_REGISTERS_ON_ASSERT
506 // Initialize assert poison page mechanism.
507 if (ShowRegistersOnAssert) {
508 initialize_assert_poison();
509 }
510 #endif // CAN_SHOW_REGISTERS_ON_ASSERT
511
512 SafepointMechanism::initialize();
513
514 jint adjust_after_os_result = Arguments::adjust_after_os();
515 if (adjust_after_os_result != JNI_OK) return adjust_after_os_result;
516
517 // Initialize output stream logging
518 ostream_init_log();
519
520 // Launch -agentlib/-agentpath and converted -Xrun agents
521 JvmtiAgentList::load_agents();
522
523 // Initialize Threads state
524 _number_of_threads = 0;
525 _number_of_non_daemon_threads = 0;
526
527 // Initialize global data structures and create system classes in heap
528 vm_init_globals();
529
530 #if INCLUDE_JVMCI
531 if (JVMCICounterSize > 0) {
532 JavaThread::_jvmci_old_thread_counters = NEW_C_HEAP_ARRAY(jlong, JVMCICounterSize, mtJVMCI);
533 memset(JavaThread::_jvmci_old_thread_counters, 0, sizeof(jlong) * JVMCICounterSize);
534 } else {
535 JavaThread::_jvmci_old_thread_counters = nullptr;
536 }
537 #endif // INCLUDE_JVMCI
538
539 // Initialize OopStorage for threadObj
540 JavaThread::_thread_oop_storage = OopStorageSet::create_strong("Thread OopStorage", mtThread);
541
542 // Attach the main thread to this os thread
543 JavaThread* main_thread = new JavaThread();
544 main_thread->set_thread_state(_thread_in_vm);
545 main_thread->initialize_thread_current();
546 // Once mutexes and main_thread are ready, we can use NmtVirtualMemoryLocker.
547 MemTracker::NmtVirtualMemoryLocker::set_safe_to_use();
548 // must do this before set_active_handles
549 main_thread->record_stack_base_and_size();
550 main_thread->register_thread_stack_with_NMT();
551 main_thread->set_active_handles(JNIHandleBlock::allocate_block());
552 MACOS_AARCH64_ONLY(main_thread->init_wx());
553
554 // Set the _monitor_owner_id now since we will run Java code before the Thread instance
555 // is even created. The same value will be assigned to the Thread instance on init.
556 main_thread->set_monitor_owner_id(ThreadIdentifier::next());
557
558 if (!Thread::set_as_starting_thread(main_thread)) {
559 vm_shutdown_during_initialization(
560 "Failed necessary internal allocation. Out of swap space");
561 main_thread->smr_delete();
562 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
563 return JNI_ENOMEM;
564 }
565
566 JFR_ONLY(Jfr::initialize_main_thread(main_thread);)
567
568 // Enable guard page *after* os::create_main_thread(), otherwise it would
569 // crash Linux VM, see notes in os_linux.cpp.
570 main_thread->stack_overflow_state()->create_stack_guard_pages();
571
572 // Initialize Java-Level synchronization subsystem
573 ObjectMonitor::Initialize();
574 ObjectSynchronizer::initialize();
575
576 // Initialize global modules
577 jint status = init_globals();
578 if (status != JNI_OK) {
579 main_thread->smr_delete();
580 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
581 return status;
582 }
583
584 // Create WatcherThread as soon as we can since we need it in case
585 // of hangs during error reporting.
586 WatcherThread::start();
587
588 // Add main_thread to threads list to finish barrier setup with
589 // on_thread_attach. Should be before starting to build Java objects in
590 // init_globals2, which invokes barriers.
591 {
592 MutexLocker mu(Threads_lock);
593 Threads::add(main_thread);
594 }
595
596 status = init_globals2();
597 if (status != JNI_OK) {
598 Threads::remove(main_thread, false);
599 // It is possible that we managed to fully initialize Universe but have then
600 // failed by throwing an exception. In that case our caller JNI_CreateJavaVM
601 // will want to report it, so we can't delete the main thread.
602 if (!main_thread->has_pending_exception()) {
603 main_thread->smr_delete();
604 }
605 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
606 return status;
607 }
608
609 ObjectMonitor::Initialize2();
610
611 JFR_ONLY(Jfr::on_create_vm_1();)
612
613 // Should be done after the heap is fully created
614 main_thread->cache_global_variables();
615
616 // Any JVMTI raw monitors entered in onload will transition into
617 // real raw monitor. VM is setup enough here for raw monitor enter.
618 JvmtiExport::transition_pending_onload_raw_monitors();
619
620 // Create the VMThread
621 { TraceTime timer("Start VMThread", TRACETIME_LOG(Info, startuptime));
622
623 VMThread::create();
624 VMThread* vmthread = VMThread::vm_thread();
625
626 if (!os::create_thread(vmthread, os::vm_thread)) {
627 vm_exit_during_initialization("Cannot create VM thread. "
628 "Out of system resources.");
629 }
630
631 // Wait for the VM thread to become ready, and VMThread::run to initialize
632 // Monitors can have spurious returns, must always check another state flag
633 {
634 MonitorLocker ml(Notify_lock);
635 os::start_thread(vmthread);
636 while (!vmthread->is_running()) {
637 ml.wait();
638 }
639 }
640 }
641
642 assert(Universe::is_fully_initialized(), "not initialized");
643 if (VerifyDuringStartup) {
644 // Make sure we're starting with a clean slate.
645 VM_Verify verify_op;
646 VMThread::execute(&verify_op);
647 }
648
649 // We need this to update the java.vm.info property in case any flags used
650 // to initially define it have been changed. This is needed for both CDS
651 // since UseSharedSpaces may be changed after java.vm.info
652 // is initially computed. See Abstract_VM_Version::vm_info_string().
653 // This update must happen before we initialize the java classes, but
654 // after any initialization logic that might modify the flags.
655 Arguments::update_vm_info_property(VM_Version::vm_info_string());
656
657 JavaThread* THREAD = JavaThread::current(); // For exception macros.
658 HandleMark hm(THREAD);
659
660 // Always call even when there are not JVMTI environments yet, since environments
661 // may be attached late and JVMTI must track phases of VM execution
662 JvmtiExport::enter_early_start_phase();
663
664 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
665 JvmtiExport::post_early_vm_start();
666
667 // Launch -Xrun agents early if EagerXrunInit is set
668 if (EagerXrunInit) {
669 JvmtiAgentList::load_xrun_agents();
670 }
671
672 initialize_java_lang_classes(main_thread, CHECK_JNI_ERR);
673
674 quicken_jni_functions();
675
676 // No more stub generation allowed after that point.
677 StubCodeDesc::freeze();
678
679 // Set flag that basic initialization has completed. Used by exceptions and various
680 // debug stuff, that does not work until all basic classes have been initialized.
681 set_init_completed();
682
683 LogConfiguration::post_initialize();
684 Metaspace::post_initialize();
685 MutexLockerImpl::post_initialize();
686
687 HOTSPOT_VM_INIT_END();
688
689 // record VM initialization completion time
690 #if INCLUDE_MANAGEMENT
691 Management::record_vm_init_completed();
692 #endif // INCLUDE_MANAGEMENT
693
694 log_info(os)("Initialized VM with process ID %d", os::current_process_id());
695
696 if (!FLAG_IS_DEFAULT(CreateCoredumpOnCrash) && CreateCoredumpOnCrash) {
697 char buffer[2*JVM_MAXPATHLEN];
698 os::check_core_dump_prerequisites(buffer, sizeof(buffer), true);
699 }
700
701 // Signal Dispatcher needs to be started before VMInit event is posted
702 os::initialize_jdk_signal_support(CHECK_JNI_ERR);
703
704 // Start Attach Listener if +StartAttachListener or it can't be started lazily
705 if (!DisableAttachMechanism) {
706 AttachListener::vm_start();
707 if (StartAttachListener || AttachListener::init_at_startup()) {
708 AttachListener::init();
709 }
710 }
711
712 // Launch -Xrun agents if EagerXrunInit is not set.
713 if (!EagerXrunInit) {
714 JvmtiAgentList::load_xrun_agents();
715 }
716
717 Arena::start_chunk_pool_cleaner_task();
718
719 // Start the service thread
720 // The service thread enqueues JVMTI deferred events and does various hashtable
721 // and other cleanups. Needs to start before the compilers start posting events.
722 ServiceThread::initialize();
723
724 // Start the monitor deflation thread:
725 MonitorDeflationThread::initialize();
726
727 // initialize compiler(s)
728 #if defined(COMPILER1) || COMPILER2_OR_JVMCI
729 bool init_compilation = true;
730 #if INCLUDE_JVMCI
731 bool force_JVMCI_initialization = false;
732 if (EnableJVMCI) {
733 // Initialize JVMCI eagerly when it is explicitly requested.
734 // Or when JVMCILibDumpJNIConfig or JVMCIPrintProperties is enabled.
735 force_JVMCI_initialization = EagerJVMCI || JVMCIPrintProperties || JVMCILibDumpJNIConfig;
736 if (!force_JVMCI_initialization && UseJVMCICompiler && !UseJVMCINativeLibrary && (!UseInterpreter || !BackgroundCompilation)) {
737 // Force initialization of jarjvmci otherwise requests for blocking
738 // compilations will not actually block until jarjvmci is initialized.
739 force_JVMCI_initialization = true;
740 }
741 if (JVMCIPrintProperties || JVMCILibDumpJNIConfig) {
742 // Both JVMCILibDumpJNIConfig and JVMCIPrintProperties exit the VM
743 // so compilation should be disabled. This prevents dumping or
744 // printing from happening more than once.
745 init_compilation = false;
746 }
747 }
748 #endif
749 if (init_compilation) {
750 CompileBroker::compilation_init(CHECK_JNI_ERR);
751 }
752 #endif
753
754 if (CDSConfig::is_using_aot_linked_classes()) {
755 AOTLinkedClassBulkLoader::finish_loading_javabase_classes(CHECK_JNI_ERR);
756 SystemDictionary::restore_archived_method_handle_intrinsics();
757 }
758
759 // Start string deduplication thread if requested.
760 if (StringDedup::is_enabled()) {
761 StringDedup::start();
762 }
763
764 // Pre-initialize some JSR292 core classes to avoid deadlock during class loading.
765 // It is done after compilers are initialized, because otherwise compilations of
766 // signature polymorphic MH intrinsics can be missed
767 // (see SystemDictionary::find_method_handle_intrinsic).
768 initialize_jsr292_core_classes(CHECK_JNI_ERR);
769
770 // This will initialize the module system. Only java.base classes can be
771 // loaded until phase 2 completes
772 call_initPhase2(CHECK_JNI_ERR);
773
774 if (CDSConfig::is_using_aot_linked_classes()) {
775 AOTLinkedClassBulkLoader::load_non_javabase_classes(THREAD);
776 }
777 #ifndef PRODUCT
778 HeapShared::initialize_test_class_from_archive(THREAD);
779 #endif
780
781 JFR_ONLY(Jfr::on_create_vm_2();)
782
783 // Always call even when there are not JVMTI environments yet, since environments
784 // may be attached late and JVMTI must track phases of VM execution
785 JvmtiExport::enter_start_phase();
786
787 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
788 JvmtiExport::post_vm_start();
789
790 // Final system initialization including security manager and system class loader
791 call_initPhase3(CHECK_JNI_ERR);
792
793 // cache the system and platform class loaders
794 SystemDictionary::compute_java_loaders(CHECK_JNI_ERR);
795
796 if (Continuations::enabled()) {
797 // Initialize Continuation class now so that failure to create enterSpecial/doYield
798 // special nmethods due to limited CodeCache size can be treated as a fatal error at
799 // startup with the proper message that CodeCache size is too small.
800 initialize_class(vmSymbols::jdk_internal_vm_Continuation(), CHECK_JNI_ERR);
801 }
802
803 if (NativeHeapTrimmer::enabled()) {
804 NativeHeapTrimmer::initialize();
805 }
806
807 // Always call even when there are not JVMTI environments yet, since environments
808 // may be attached late and JVMTI must track phases of VM execution
809 JvmtiExport::enter_live_phase();
810
811 // Make perfmemory accessible
812 PerfMemory::set_accessible(true);
813
814 // Notify JVMTI agents that VM initialization is complete - nop if no agents.
815 JvmtiExport::post_vm_initialized();
816
817 #if INCLUDE_JVMCI
818 if (force_JVMCI_initialization) {
819 JVMCI::initialize_compiler(CHECK_JNI_ERR);
820 }
821 #endif
822
823 JFR_ONLY(Jfr::on_create_vm_3();)
824
825 #if INCLUDE_MANAGEMENT
826 Management::initialize(THREAD);
827
828 if (HAS_PENDING_EXCEPTION) {
829 // management agent fails to start possibly due to
830 // configuration problem and is responsible for printing
831 // stack trace if appropriate. Simply exit VM.
832 vm_exit(1);
833 }
834 #endif // INCLUDE_MANAGEMENT
835
836 StatSampler::engage();
837 if (CheckJNICalls) JniPeriodicChecker::engage();
838
839 call_postVMInitHook(THREAD);
840 // The Java side of PostVMInitHook.run must deal with all
841 // exceptions and provide means of diagnosis.
842 if (HAS_PENDING_EXCEPTION) {
843 CLEAR_PENDING_EXCEPTION;
844 }
845
846 // Let WatcherThread run all registered periodic tasks now.
847 // NOTE: All PeriodicTasks should be registered by now. If they
848 // aren't, late joiners might appear to start slowly (we might
849 // take a while to process their first tick).
850 WatcherThread::run_all_tasks();
851
852 create_vm_timer.end();
853 #ifdef ASSERT
854 _vm_complete = true;
855 #endif
856
857 if (CDSConfig::is_dumping_classic_static_archive()) {
858 // Classic -Xshare:dump, aka "old workflow"
859 MetaspaceShared::preload_and_dump(CHECK_JNI_ERR);
860 } else if (CDSConfig::is_dumping_final_static_archive()) {
861 tty->print_cr("Reading AOTConfiguration %s and writing AOTCache %s", AOTConfiguration, AOTCache);
862 MetaspaceShared::preload_and_dump(CHECK_JNI_ERR);
863 }
864
865 if (log_is_enabled(Info, perf, class, link)) {
866 LogStreamHandle(Info, perf, class, link) log;
867 log.print_cr("At VM initialization completion:");
868 ClassLoader::print_counters(&log);
869 }
870
871 return JNI_OK;
872 }
873
874 // Threads::destroy_vm() is normally called from jni_DestroyJavaVM() when
875 // the program falls off the end of main(). Another VM exit path is through
876 // vm_exit(), when the program calls System.exit() to return a value, or when
877 // there is a serious error in VM.
878 // These two separate shutdown paths are not exactly the same, but they share
879 // Shutdown.shutdown() at Java level and before_exit() and VM_Exit op at VM level.
880 //
881 // Shutdown sequence:
882 // + Shutdown native memory tracking if it is on
883 // + Wait until we are the last non-daemon thread to execute
884 // <-- every thing is still working at this moment -->
885 // + Call java.lang.Shutdown.shutdown(), which will invoke Java level
886 // shutdown hooks
887 // + Call before_exit(), prepare for VM exit
888 // > run VM level shutdown hooks (they are registered through JVM_OnExit(),
889 // currently the only user of this mechanism is File.deleteOnExit())
890 // > stop StatSampler, watcher thread,
891 // post thread end and vm death events to JVMTI,
892 // stop signal thread
893 // + Call JavaThread::exit(), it will:
894 // > release JNI handle blocks, remove stack guard pages
895 // > remove this thread from Threads list
896 // <-- no more Java code from this thread after this point -->
897 // + Stop VM thread, it will bring the remaining VM to a safepoint and stop
898 // the compiler threads at safepoint
899 // <-- do not use anything that could get blocked by Safepoint -->
900 // + Disable tracing at JNI/JVM barriers
901 // + Set _vm_exited flag for threads that are still running native code
902 // + Call exit_globals()
903 // > deletes tty
904 // > deletes PerfMemory resources
905 // + Delete this thread
906 // + Return to caller
907
908 void Threads::destroy_vm() {
909 JavaThread* thread = JavaThread::current();
910
911 #ifdef ASSERT
912 _vm_complete = false;
913 #endif
914 // Wait until we are the last non-daemon thread to execute, or
915 // if we are a daemon then wait until the last non-daemon thread has
916 // executed.
917 bool daemon = java_lang_Thread::is_daemon(thread->threadObj());
918 int expected = daemon ? 0 : 1;
919 {
920 MonitorLocker nu(Threads_lock);
921 while (Threads::number_of_non_daemon_threads() > expected)
922 // This wait should make safepoint checks, wait without a timeout.
923 nu.wait(0);
924 }
925
926 EventShutdown e;
927 if (e.should_commit()) {
928 e.set_reason("No remaining non-daemon Java threads");
929 e.commit();
930 }
931
932 // Hang forever on exit if we are reporting an error.
933 if (ShowMessageBoxOnError && VMError::is_error_reported()) {
934 os::infinite_sleep();
935 }
936 os::wait_for_keypress_at_exit();
937
938 // run Java level shutdown hooks
939 thread->invoke_shutdown_hooks();
940
941 before_exit(thread);
942
943 thread->exit(true);
944
945 // We are no longer on the main thread list but could still be in a
946 // secondary list where another thread may try to interact with us.
947 // So wait until all such interactions are complete before we bring
948 // the VM to the termination safepoint. Normally this would be done
949 // using thread->smr_delete() below where we delete the thread, but
950 // we can't call that after the termination safepoint is active as
951 // we will deadlock on the Threads_lock. Once all interactions are
952 // complete it is safe to directly delete the thread at any time.
953 ThreadsSMRSupport::wait_until_not_protected(thread);
954
955 // Stop VM thread.
956 {
957 // 4945125 The vm thread comes to a safepoint during exit.
958 // GC vm_operations can get caught at the safepoint, and the
959 // heap is unparseable if they are caught. Grab the Heap_lock
960 // to prevent this. The GC vm_operations will not be able to
961 // queue until after the vm thread is dead. After this point,
962 // we'll never emerge out of the safepoint before the VM exits.
963 // Assert that the thread is terminated so that acquiring the
964 // Heap_lock doesn't cause the terminated thread to participate in
965 // the safepoint protocol.
966
967 assert(thread->is_terminated(), "must be terminated here");
968 MutexLocker ml(Heap_lock);
969
970 VMThread::wait_for_vm_thread_exit();
971 assert(SafepointSynchronize::is_at_safepoint(), "VM thread should exit at Safepoint");
972 VMThread::destroy();
973 }
974
975 // Now, all Java threads are gone except daemon threads. Daemon threads
976 // running Java code or in VM are stopped by the Safepoint. However,
977 // daemon threads executing native code are still running. But they
978 // will be stopped at native=>Java/VM barriers. Note that we can't
979 // simply kill or suspend them, as it is inherently deadlock-prone.
980
981 VM_Exit::set_vm_exited();
982
983 // Clean up ideal graph printers after the VMThread has started
984 // the final safepoint which will block all the Compiler threads.
985 // Note that this Thread has already logically exited so the
986 // clean_up() function's use of a JavaThreadIteratorWithHandle
987 // would be a problem except set_vm_exited() has remembered the
988 // shutdown thread which is granted a policy exception.
989 #if defined(COMPILER2) && !defined(PRODUCT)
990 IdealGraphPrinter::clean_up();
991 #endif
992
993 notify_vm_shutdown();
994
995 // exit_globals() will delete tty
996 exit_globals();
997
998 // Deleting the shutdown thread here is safe. See comment on
999 // wait_until_not_protected() above.
1000 delete thread;
1001
1002 #if INCLUDE_JVMCI
1003 if (JVMCICounterSize > 0) {
1004 FREE_C_HEAP_ARRAY(jlong, JavaThread::_jvmci_old_thread_counters);
1005 }
1006 #endif
1007
1008 LogConfiguration::finalize();
1009 }
1010
1011
1012 jboolean Threads::is_supported_jni_version_including_1_1(jint version) {
1013 if (version == JNI_VERSION_1_1) return JNI_TRUE;
1014 return is_supported_jni_version(version);
1015 }
1016
1017
1018 jboolean Threads::is_supported_jni_version(jint version) {
1019 if (version == JNI_VERSION_1_2) return JNI_TRUE;
1020 if (version == JNI_VERSION_1_4) return JNI_TRUE;
1021 if (version == JNI_VERSION_1_6) return JNI_TRUE;
1022 if (version == JNI_VERSION_1_8) return JNI_TRUE;
1023 if (version == JNI_VERSION_9) return JNI_TRUE;
1024 if (version == JNI_VERSION_10) return JNI_TRUE;
1025 if (version == JNI_VERSION_19) return JNI_TRUE;
1026 if (version == JNI_VERSION_20) return JNI_TRUE;
1027 if (version == JNI_VERSION_21) return JNI_TRUE;
1028 if (version == JNI_VERSION_24) return JNI_TRUE;
1029 return JNI_FALSE;
1030 }
1031
1032 void Threads::add(JavaThread* p, bool force_daemon) {
1033 // The threads lock must be owned at this point
1034 assert(Threads_lock->owned_by_self(), "must have threads lock");
1035 assert(p->monitor_owner_id() != 0, "should be set");
1036
1037 BarrierSet::barrier_set()->on_thread_attach(p);
1038
1039 // Once a JavaThread is added to the Threads list, smr_delete() has
1040 // to be used to delete it. Otherwise we can just delete it directly.
1041 p->set_on_thread_list();
1042
1043 _number_of_threads++;
1044 oop threadObj = p->threadObj();
1045 bool daemon = true;
1046 // Bootstrapping problem: threadObj can be null for initial
1047 // JavaThread (or for threads attached via JNI)
1048 if (!force_daemon &&
1049 (threadObj == nullptr || !java_lang_Thread::is_daemon(threadObj))) {
1050 _number_of_non_daemon_threads++;
1051 daemon = false;
1052 }
1053
1054 ThreadService::add_thread(p, daemon);
1055
1056 // Maintain fast thread list
1057 ThreadsSMRSupport::add_thread(p);
1058
1059 // Increase the ObjectMonitor ceiling for the new thread.
1060 ObjectSynchronizer::inc_in_use_list_ceiling();
1061
1062 // Possible GC point.
1063 Events::log(Thread::current(), "Thread added: " INTPTR_FORMAT, p2i(p));
1064
1065 // Make new thread known to active EscapeBarrier
1066 EscapeBarrier::thread_added(p);
1067 }
1068
1069 void Threads::remove(JavaThread* p, bool is_daemon) {
1070 // Extra scope needed for Thread_lock, so we can check
1071 // that we do not remove thread without safepoint code notice
1072 {
1073 ConditionalMutexLocker throttle_ml(ThreadsLockThrottle_lock, UseThreadsLockThrottleLock);
1074 MonitorLocker ml(Threads_lock);
1075
1076 if (ThreadIdTable::is_initialized()) {
1077 // This cleanup must be done before the current thread's GC barrier
1078 // is detached since we need to touch the threadObj oop.
1079 jlong tid = SharedRuntime::get_java_tid(p);
1080 ThreadIdTable::remove_thread(tid);
1081 }
1082
1083 // BarrierSet state must be destroyed after the last thread transition
1084 // before the thread terminates. Thread transitions result in calls to
1085 // StackWatermarkSet::on_safepoint(), which performs GC processing,
1086 // requiring the GC state to be alive.
1087 BarrierSet::barrier_set()->on_thread_detach(p);
1088 if (p->is_exiting()) {
1089 // If we got here via JavaThread::exit(), then we remember that the
1090 // thread's GC barrier has been detached. We don't do this when we get
1091 // here from another path, e.g., cleanup_failed_attach_current_thread().
1092 p->set_terminated(JavaThread::_thread_gc_barrier_detached);
1093 }
1094
1095 assert(ThreadsSMRSupport::get_java_thread_list()->includes(p), "p must be present");
1096
1097 // Maintain fast thread list
1098 ThreadsSMRSupport::remove_thread(p);
1099
1100 _number_of_threads--;
1101 if (!is_daemon) {
1102 _number_of_non_daemon_threads--;
1103
1104 // If this is the last non-daemon thread then we need to do
1105 // a notify on the Threads_lock so a thread waiting
1106 // on destroy_vm will wake up. But that thread could be a daemon
1107 // or non-daemon, so we notify for both the 0 and 1 case.
1108 if (number_of_non_daemon_threads() <= 1) {
1109 ml.notify_all();
1110 }
1111 }
1112 ThreadService::remove_thread(p, is_daemon);
1113
1114 // Make sure that safepoint code disregard this thread. This is needed since
1115 // the thread might mess around with locks after this point. This can cause it
1116 // to do callbacks into the safepoint code. However, the safepoint code is not aware
1117 // of this thread since it is removed from the queue.
1118 p->set_terminated(JavaThread::_thread_terminated);
1119
1120 // Notify threads waiting in EscapeBarriers
1121 EscapeBarrier::thread_removed(p);
1122 } // unlock Threads_lock and ThreadsLockThrottle_lock
1123
1124 // Reduce the ObjectMonitor ceiling for the exiting thread.
1125 ObjectSynchronizer::dec_in_use_list_ceiling();
1126
1127 // Since Events::log uses a lock, we grab it outside the Threads_lock
1128 Events::log(Thread::current(), "Thread exited: " INTPTR_FORMAT, p2i(p));
1129 }
1130
1131 // Operations on the Threads list for GC. These are not explicitly locked,
1132 // but the garbage collector must provide a safe context for them to run.
1133 // In particular, these things should never be called when the Threads_lock
1134 // is held by some other thread. (Note: the Safepoint abstraction also
1135 // uses the Threads_lock to guarantee this property. It also makes sure that
1136 // all threads gets blocked when exiting or starting).
1137
1138 void Threads::oops_do(OopClosure* f, NMethodClosure* cf) {
1139 ALL_JAVA_THREADS(p) {
1140 p->oops_do(f, cf);
1141 }
1142 VMThread::vm_thread()->oops_do(f, cf);
1143 }
1144
1145 void Threads::change_thread_claim_token() {
1146 if (++_thread_claim_token == 0) {
1147 // On overflow of the token counter, there is a risk of future
1148 // collisions between a new global token value and a stale token
1149 // for a thread, because not all iterations visit all threads.
1150 // (Though it's pretty much a theoretical concern for non-trivial
1151 // token counter sizes.) To deal with the possibility, reset all
1152 // the thread tokens to zero on global token overflow.
1153 struct ResetClaims : public ThreadClosure {
1154 virtual void do_thread(Thread* t) {
1155 t->claim_threads_do(false, 0);
1156 }
1157 } reset_claims;
1158 Threads::threads_do(&reset_claims);
1159 // On overflow, update the global token to non-zero, to
1160 // avoid the special "never claimed" initial thread value.
1161 _thread_claim_token = 1;
1162 }
1163 }
1164
1165 #ifdef ASSERT
1166 static void assert_thread_claimed(const char* kind, Thread* t, uintx expected) {
1167 const uintx token = t->threads_do_token();
1168 assert(token == expected,
1169 "%s " PTR_FORMAT " has incorrect value %zu != %zu",
1170 kind, p2i(t), token, expected);
1171 }
1172
1173 void Threads::assert_all_threads_claimed() {
1174 ALL_JAVA_THREADS(p) {
1175 assert_thread_claimed("JavaThread", p, _thread_claim_token);
1176 }
1177
1178 struct NJTClaimedVerifierClosure : public ThreadClosure {
1179 uintx _thread_claim_token;
1180
1181 NJTClaimedVerifierClosure(uintx thread_claim_token) : ThreadClosure(), _thread_claim_token(thread_claim_token) { }
1182
1183 virtual void do_thread(Thread* thread) override {
1184 assert_thread_claimed("Non-JavaThread", VMThread::vm_thread(), _thread_claim_token);
1185 }
1186 } tc(_thread_claim_token);
1187
1188 non_java_threads_do(&tc);
1189 }
1190 #endif // ASSERT
1191
1192 class ParallelOopsDoThreadClosure : public ThreadClosure {
1193 private:
1194 OopClosure* _f;
1195 NMethodClosure* _cf;
1196 public:
1197 ParallelOopsDoThreadClosure(OopClosure* f, NMethodClosure* cf) : _f(f), _cf(cf) {}
1198 void do_thread(Thread* t) {
1199 t->oops_do(_f, _cf);
1200 }
1201 };
1202
1203 void Threads::possibly_parallel_oops_do(bool is_par, OopClosure* f, NMethodClosure* cf) {
1204 ParallelOopsDoThreadClosure tc(f, cf);
1205 possibly_parallel_threads_do(is_par, &tc);
1206 }
1207
1208 void Threads::metadata_do(MetadataClosure* f) {
1209 ALL_JAVA_THREADS(p) {
1210 p->metadata_do(f);
1211 }
1212 }
1213
1214 class ThreadHandlesClosure : public ThreadClosure {
1215 void (*_f)(Metadata*);
1216 public:
1217 ThreadHandlesClosure(void f(Metadata*)) : _f(f) {}
1218 virtual void do_thread(Thread* thread) {
1219 thread->metadata_handles_do(_f);
1220 }
1221 };
1222
1223 void Threads::metadata_handles_do(void f(Metadata*)) {
1224 // Only walk the Handles in Thread.
1225 ThreadHandlesClosure handles_closure(f);
1226 threads_do(&handles_closure);
1227 }
1228
1229 #if INCLUDE_JVMTI
1230 // Get Java threads that are waiting to enter or re-enter the specified monitor.
1231 // Java threads that are executing mounted virtual threads are not included.
1232 GrowableArray<JavaThread*>* Threads::get_pending_threads(ThreadsList * t_list,
1233 int count,
1234 address monitor) {
1235 assert(Thread::current()->is_VM_thread(), "Must be the VM thread");
1236 GrowableArray<JavaThread*>* result = new GrowableArray<JavaThread*>(count);
1237
1238 int i = 0;
1239 for (JavaThread* p : *t_list) {
1240 if (!p->can_call_java()) continue;
1241
1242 oop thread_oop = JvmtiEnvBase::get_vthread_or_thread_oop(p);
1243 if (thread_oop->is_a(vmClasses::BaseVirtualThread_klass())) {
1244 continue;
1245 }
1246 // The first stage of async deflation does not affect any field
1247 // used by this comparison so the ObjectMonitor* is usable here.
1248 address pending = (address)p->current_pending_monitor();
1249 address waiting = (address)p->current_waiting_monitor();
1250 // do not include virtual threads to the list
1251 jint state = JvmtiEnvBase::get_thread_state(thread_oop, p);
1252 if (pending == monitor || (waiting == monitor &&
1253 (state & JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER))
1254 ) { // found a match
1255 if (i < count) result->append(p); // save the first count matches
1256 i++;
1257 }
1258 }
1259
1260 return result;
1261 }
1262 #endif // INCLUDE_JVMTI
1263
1264 JavaThread *Threads::owning_thread_from_stacklock(ThreadsList * t_list, address basicLock) {
1265 assert(LockingMode == LM_LEGACY, "Not with new lightweight locking");
1266
1267 JavaThread* the_owner = nullptr;
1268 for (JavaThread* q : *t_list) {
1269 if (q->is_lock_owned(basicLock)) {
1270 the_owner = q;
1271 break;
1272 }
1273 }
1274 return the_owner;
1275 }
1276
1277 JavaThread* Threads::owning_thread_from_object(ThreadsList * t_list, oop obj) {
1278 assert(LockingMode == LM_LIGHTWEIGHT, "Only with new lightweight locking");
1279 for (JavaThread* q : *t_list) {
1280 // Need to start processing before accessing oops in the thread.
1281 StackWatermark* watermark = StackWatermarkSet::get(q, StackWatermarkKind::gc);
1282 if (watermark != nullptr) {
1283 watermark->start_processing();
1284 }
1285
1286 if (q->lock_stack().contains(obj)) {
1287 return q;
1288 }
1289 }
1290 return nullptr;
1291 }
1292
1293 JavaThread* Threads::owning_thread_from_monitor(ThreadsList* t_list, ObjectMonitor* monitor) {
1294 if (monitor->has_anonymous_owner()) {
1295 if (LockingMode == LM_LIGHTWEIGHT) {
1296 return owning_thread_from_object(t_list, monitor->object());
1297 } else {
1298 assert(LockingMode == LM_LEGACY, "invariant");
1299 return owning_thread_from_stacklock(t_list, (address)monitor->stack_locker());
1300 }
1301 } else {
1302 JavaThread* the_owner = nullptr;
1303 for (JavaThread* q : *t_list) {
1304 if (monitor->has_owner(q)) {
1305 the_owner = q;
1306 break;
1307 }
1308 }
1309 return the_owner;
1310 }
1311 }
1312
1313 class PrintOnClosure : public ThreadClosure {
1314 private:
1315 outputStream* _st;
1316
1317 public:
1318 PrintOnClosure(outputStream* st) :
1319 _st(st) {}
1320
1321 virtual void do_thread(Thread* thread) {
1322 if (thread != nullptr) {
1323 thread->print_on(_st);
1324 _st->cr();
1325 }
1326 }
1327 };
1328
1329 // Threads::print_on() is called at safepoint by VM_PrintThreads operation.
1330 void Threads::print_on(outputStream* st, bool print_stacks,
1331 bool internal_format, bool print_concurrent_locks,
1332 bool print_extended_info) {
1333 char buf[32];
1334 st->print_raw_cr(os::local_time_string(buf, sizeof(buf)));
1335
1336 st->print_cr("Full thread dump %s (%s %s):",
1337 VM_Version::vm_name(),
1338 VM_Version::vm_release(),
1339 VM_Version::vm_info_string());
1340 st->cr();
1341
1342 #if INCLUDE_SERVICES
1343 // Dump concurrent locks
1344 ConcurrentLocksDump concurrent_locks;
1345 if (print_concurrent_locks) {
1346 concurrent_locks.dump_at_safepoint();
1347 }
1348 #endif // INCLUDE_SERVICES
1349
1350 ThreadsSMRSupport::print_info_on(st);
1351 st->cr();
1352
1353 ALL_JAVA_THREADS(p) {
1354 ResourceMark rm;
1355 p->print_on(st, print_extended_info);
1356 if (print_stacks) {
1357 if (internal_format) {
1358 p->trace_stack();
1359 } else {
1360 p->print_stack_on(st);
1361 if (p->is_vthread_mounted()) {
1362 st->print_cr(" Mounted virtual thread #" INT64_FORMAT, java_lang_Thread::thread_id(p->vthread()));
1363 p->print_vthread_stack_on(st);
1364 }
1365 }
1366 }
1367 st->cr();
1368 #if INCLUDE_SERVICES
1369 if (print_concurrent_locks) {
1370 concurrent_locks.print_locks_on(p, st);
1371 }
1372 #endif // INCLUDE_SERVICES
1373 }
1374
1375 PrintOnClosure cl(st);
1376 non_java_threads_do(&cl);
1377
1378 st->flush();
1379 }
1380
1381 void Threads::print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
1382 int buflen, bool* found_current) {
1383 if (this_thread != nullptr) {
1384 bool is_current = (current == this_thread);
1385 *found_current = *found_current || is_current;
1386 st->print("%s", is_current ? "=>" : " ");
1387
1388 st->print(PTR_FORMAT, p2i(this_thread));
1389 st->print(" ");
1390 this_thread->print_on_error(st, buf, buflen);
1391 st->cr();
1392 }
1393 }
1394
1395 class PrintOnErrorClosure : public ThreadClosure {
1396 outputStream* _st;
1397 Thread* _current;
1398 char* _buf;
1399 int _buflen;
1400 bool* _found_current;
1401 unsigned _num_printed;
1402 public:
1403 PrintOnErrorClosure(outputStream* st, Thread* current, char* buf,
1404 int buflen, bool* found_current) :
1405 _st(st), _current(current), _buf(buf), _buflen(buflen), _found_current(found_current),
1406 _num_printed(0) {}
1407
1408 virtual void do_thread(Thread* thread) {
1409 _num_printed++;
1410 Threads::print_on_error(thread, _st, _current, _buf, _buflen, _found_current);
1411 }
1412
1413 unsigned num_printed() const { return _num_printed; }
1414 };
1415
1416 // Threads::print_on_error() is called by fatal error handler. It's possible
1417 // that VM is not at safepoint and/or current thread is inside signal handler.
1418 // Don't print stack trace, as the stack may not be walkable. Don't allocate
1419 // memory (even in resource area), it might deadlock the error handler.
1420 void Threads::print_on_error(outputStream* st, Thread* current, char* buf,
1421 int buflen) {
1422 ThreadsSMRSupport::print_info_on(st);
1423 st->cr();
1424
1425 bool found_current = false;
1426 st->print_cr("Java Threads: ( => current thread )");
1427 unsigned num_java = 0;
1428 ALL_JAVA_THREADS(thread) {
1429 print_on_error(thread, st, current, buf, buflen, &found_current);
1430 num_java++;
1431 }
1432 st->print_cr("Total: %u", num_java);
1433 st->cr();
1434
1435 st->print_cr("Other Threads:");
1436 unsigned num_other = ((VMThread::vm_thread() != nullptr) ? 1 : 0) +
1437 ((WatcherThread::watcher_thread() != nullptr) ? 1 : 0) +
1438 ((AsyncLogWriter::instance() != nullptr) ? 1 : 0);
1439 print_on_error(VMThread::vm_thread(), st, current, buf, buflen, &found_current);
1440 print_on_error(WatcherThread::watcher_thread(), st, current, buf, buflen, &found_current);
1441 print_on_error(AsyncLogWriter::instance(), st, current, buf, buflen, &found_current);
1442
1443 if (Universe::heap() != nullptr) {
1444 PrintOnErrorClosure print_closure(st, current, buf, buflen, &found_current);
1445 Universe::heap()->gc_threads_do(&print_closure);
1446 num_other += print_closure.num_printed();
1447 }
1448
1449 if (!found_current) {
1450 st->cr();
1451 st->print("=>" PTR_FORMAT " (exited) ", p2i(current));
1452 current->print_on_error(st, buf, buflen);
1453 num_other++;
1454 st->cr();
1455 }
1456 st->print_cr("Total: %u", num_other);
1457 st->cr();
1458
1459 st->print_cr("Threads with active compile tasks:");
1460 unsigned num = print_threads_compiling(st, buf, buflen);
1461 st->print_cr("Total: %u", num);
1462 }
1463
1464 unsigned Threads::print_threads_compiling(outputStream* st, char* buf, int buflen, bool short_form) {
1465 unsigned num = 0;
1466 ALL_JAVA_THREADS(thread) {
1467 if (thread->is_Compiler_thread()) {
1468 CompilerThread* ct = (CompilerThread*) thread;
1469
1470 // Keep task in local variable for null check.
1471 // ct->_task might be set to null by concurring compiler thread
1472 // because it completed the compilation. The task is never freed,
1473 // though, just returned to a free list.
1474 CompileTask* task = ct->task();
1475 if (task != nullptr) {
1476 thread->print_name_on_error(st, buf, buflen);
1477 st->print(" ");
1478 task->print(st, nullptr, short_form, true);
1479 num++;
1480 }
1481 }
1482 }
1483 return num;
1484 }
1485
1486 void Threads::verify() {
1487 ALL_JAVA_THREADS(p) {
1488 p->verify();
1489 }
1490 VMThread* thread = VMThread::vm_thread();
1491 if (thread != nullptr) thread->verify();
1492 }