1 /*
2 * Copyright (c) 1997, 2025, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2021, Azul Systems, Inc. All rights reserved.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26 #include "cds/aotLinkedClassBulkLoader.hpp"
27 #include "cds/aotMetaspace.hpp"
28 #include "cds/cds_globals.hpp"
29 #include "cds/cdsConfig.hpp"
30 #include "cds/heapShared.hpp"
31 #include "classfile/classLoader.hpp"
32 #include "classfile/javaClasses.hpp"
33 #include "classfile/javaThreadStatus.hpp"
34 #include "classfile/symbolTable.hpp"
35 #include "classfile/systemDictionary.hpp"
36 #include "classfile/vmClasses.hpp"
37 #include "classfile/vmSymbols.hpp"
38 #include "compiler/compileBroker.hpp"
39 #include "compiler/compilerThread.hpp"
40 #include "compiler/compileTask.hpp"
41 #include "gc/shared/barrierSet.hpp"
42 #include "gc/shared/barrierSetNMethod.hpp"
43 #include "gc/shared/gcVMOperations.hpp"
44 #include "gc/shared/oopStorage.hpp"
45 #include "gc/shared/oopStorageSet.hpp"
46 #include "gc/shared/stringdedup/stringDedup.hpp"
47 #include "jfr/jfrEvents.hpp"
48 #include "jvm.h"
49 #include "jvmtifiles/jvmtiEnv.hpp"
50 #include "logging/log.hpp"
51 #include "logging/logAsyncWriter.hpp"
52 #include "logging/logConfiguration.hpp"
53 #include "memory/allocation.inline.hpp"
54 #include "memory/iterator.hpp"
55 #include "memory/oopFactory.hpp"
56 #include "memory/resourceArea.hpp"
57 #include "memory/universe.hpp"
58 #include "nmt/memTracker.hpp"
59 #include "oops/instanceKlass.hpp"
60 #include "oops/klass.inline.hpp"
61 #include "oops/oop.inline.hpp"
62 #include "oops/symbol.hpp"
63 #include "prims/jvm_misc.hpp"
64 #include "prims/jvmtiAgentList.hpp"
65 #include "prims/jvmtiEnvBase.hpp"
66 #include "runtime/arguments.hpp"
67 #include "runtime/fieldDescriptor.inline.hpp"
68 #include "runtime/flags/jvmFlagLimit.hpp"
69 #include "runtime/globals.hpp"
70 #include "runtime/globals_extension.hpp"
71 #include "runtime/handles.inline.hpp"
72 #include "runtime/interfaceSupport.inline.hpp"
73 #include "runtime/java.hpp"
74 #include "runtime/javaCalls.hpp"
75 #include "runtime/javaThread.inline.hpp"
76 #include "runtime/jniHandles.inline.hpp"
77 #include "runtime/jniPeriodicChecker.hpp"
78 #include "runtime/lockStack.inline.hpp"
79 #include "runtime/monitorDeflationThread.hpp"
80 #include "runtime/mutexLocker.hpp"
81 #include "runtime/nonJavaThread.hpp"
82 #include "runtime/objectMonitor.inline.hpp"
83 #include "runtime/osThread.hpp"
84 #include "runtime/perfData.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/stubCodeGenerator.hpp"
92 #include "runtime/thread.inline.hpp"
93 #include "runtime/threads.hpp"
94 #include "runtime/threadSMR.inline.hpp"
95 #include "runtime/timer.hpp"
96 #include "runtime/timerTrace.hpp"
97 #include "runtime/trimNativeHeap.hpp"
98 #include "runtime/vm_version.hpp"
99 #include "runtime/vmOperations.hpp"
100 #include "sanitizers/address.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 // This is before the execution of the very first Java bytecode.
348 if (CDSConfig::is_using_aot_linked_classes()) {
349 AOTLinkedClassBulkLoader::link_classes(THREAD);
350 }
351
352 initialize_class(vmSymbols::java_lang_String(), CHECK);
353
354 // Inject CompactStrings value after the static initializers for String ran.
355 java_lang_String::set_compact_strings(CompactStrings);
356
357 // Initialize java_lang.System (needed before creating the thread)
358 initialize_class(vmSymbols::java_lang_System(), CHECK);
359 // The VM creates & returns objects of this class. Make sure it's initialized.
360 initialize_class(vmSymbols::java_lang_Class(), CHECK);
361
362 initialize_class(vmSymbols::java_lang_ThreadGroup(), CHECK);
363 Handle thread_group = create_initial_thread_group(CHECK);
364 Universe::set_main_thread_group(thread_group());
365 initialize_class(vmSymbols::java_lang_Thread(), CHECK);
366 create_initial_thread(thread_group, main_thread, CHECK);
367
368 HeapShared::init_box_classes(CHECK);
369
370 // The VM creates objects of this class.
371 initialize_class(vmSymbols::java_lang_Module(), CHECK);
372
373 #ifdef ASSERT
374 InstanceKlass *k = vmClasses::UnsafeConstants_klass();
375 assert(k->is_not_initialized(), "UnsafeConstants should not already be initialized");
376 #endif
377
378 // initialize the hardware-specific constants needed by Unsafe
379 initialize_class(vmSymbols::jdk_internal_misc_UnsafeConstants(), CHECK);
380 jdk_internal_misc_UnsafeConstants::set_unsafe_constants();
381
382 // The VM preresolves methods to these classes. Make sure that they get initialized
383 initialize_class(vmSymbols::java_lang_reflect_Method(), CHECK);
384 initialize_class(vmSymbols::java_lang_ref_Finalizer(), CHECK);
385
386 // Phase 1 of the system initialization in the library, java.lang.System class initialization
387 call_initPhase1(CHECK);
388
389 // Get the Java runtime name, version, and vendor info after java.lang.System is initialized.
390 // Some values are actually configure-time constants but some can be set via the jlink tool and
391 // so must be read dynamically. We treat them all the same.
392 InstanceKlass* ik = SystemDictionary::find_instance_klass(THREAD, vmSymbols::java_lang_VersionProps(),
393 Handle());
394 {
395 ResourceMark rm(main_thread);
396 JDK_Version::set_java_version(get_java_version_info(ik, vmSymbols::java_version_name()));
397
398 JDK_Version::set_runtime_name(get_java_version_info(ik, vmSymbols::java_runtime_name_name()));
399
400 JDK_Version::set_runtime_version(get_java_version_info(ik, vmSymbols::java_runtime_version_name()));
401
402 JDK_Version::set_runtime_vendor_version(get_java_version_info(ik, vmSymbols::java_runtime_vendor_version_name()));
403
404 JDK_Version::set_runtime_vendor_vm_bug_url(get_java_version_info(ik, vmSymbols::java_runtime_vendor_vm_bug_url_name()));
405 }
406
407 // an instance of OutOfMemory exception has been allocated earlier
408 initialize_class(vmSymbols::java_lang_OutOfMemoryError(), CHECK);
409 initialize_class(vmSymbols::java_lang_NullPointerException(), CHECK);
410 initialize_class(vmSymbols::java_lang_ClassCastException(), CHECK);
411 initialize_class(vmSymbols::java_lang_ArrayStoreException(), CHECK);
412 initialize_class(vmSymbols::java_lang_ArithmeticException(), CHECK);
413 initialize_class(vmSymbols::jdk_internal_vm_PreemptedException(), CHECK);
414 initialize_class(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), CHECK);
415 initialize_class(vmSymbols::java_lang_StackOverflowError(), CHECK);
416 initialize_class(vmSymbols::java_lang_IllegalMonitorStateException(), CHECK);
417 initialize_class(vmSymbols::java_lang_IllegalArgumentException(), CHECK);
418 initialize_class(vmSymbols::java_lang_InternalError(), CHECK);
419 }
420
421 void Threads::initialize_jsr292_core_classes(TRAPS) {
422 TraceTime timer("Initialize java.lang.invoke classes", TRACETIME_LOG(Info, startuptime));
423
424 initialize_class(vmSymbols::java_lang_invoke_MethodHandle(), CHECK);
425 initialize_class(vmSymbols::java_lang_invoke_ResolvedMethodName(), CHECK);
426 initialize_class(vmSymbols::java_lang_invoke_MemberName(), CHECK);
427 initialize_class(vmSymbols::java_lang_invoke_MethodHandleNatives(), CHECK);
428
429 if (UseSharedSpaces) {
430 HeapShared::initialize_java_lang_invoke(CHECK);
431 }
432 }
433
434 // One-shot PeriodicTask subclass for reading the release file
435 class ReadReleaseFileTask : public PeriodicTask {
436 public:
437 ReadReleaseFileTask() : PeriodicTask(100) {}
438
439 virtual void task() {
440 os::read_image_release_file();
441
442 // Reclaim our storage and disenroll ourself.
443 delete this;
444 }
445 };
446
447 jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) {
448 extern void JDK_Version_init();
449
450 // Preinitialize version info.
451 VM_Version::early_initialize();
452
453 // Check version
454 if (!is_supported_jni_version(args->version)) return JNI_EVERSION;
455
456 // Deferred "static" initialization
457 NonJavaThread::init();
458
459 // Initialize library-based TLS
460 ThreadLocalStorage::init();
461
462 // Initialize the output stream module
463 ostream_init();
464
465 // Process java launcher properties.
466 Arguments::process_sun_java_launcher_properties(args);
467
468 // Initialize the os module
469 os::init();
470
471 // Initialize memory pools
472 Arena::initialize_chunk_pool();
473
474 MACOS_AARCH64_ONLY(os::current_thread_enable_wx(WXWrite));
475
476 // Record VM creation timing statistics
477 TraceVmCreationTime create_vm_timer;
478 create_vm_timer.start();
479
480 // Initialize system properties.
481 Arguments::init_system_properties();
482
483 // So that JDK version can be used as a discriminator when parsing arguments
484 JDK_Version_init();
485
486 // Update/Initialize System properties after JDK version number is known
487 Arguments::init_version_specific_system_properties();
488
489 // Make sure to initialize log configuration *before* parsing arguments
490 LogConfiguration::initialize(create_vm_timer.begin_time());
491
492 // Parse arguments
493 // Note: this internally calls os::init_container_support()
494 jint parse_result = Arguments::parse(args);
495 if (parse_result != JNI_OK) return parse_result;
496
497 // Initialize NMT right after argument parsing to keep the pre-NMT-init window small.
498 MemTracker::initialize();
499
500 os::init_before_ergo();
501
502 jint ergo_result = Arguments::apply_ergo();
503 if (ergo_result != JNI_OK) return ergo_result;
504
505 // Final check of all ranges after ergonomics which may change values.
506 if (!JVMFlagLimit::check_all_ranges()) {
507 return JNI_EINVAL;
508 }
509
510 // Final check of all 'AfterErgo' constraints after ergonomics which may change values.
511 bool constraint_result = JVMFlagLimit::check_all_constraints(JVMFlagConstraintPhase::AfterErgo);
512 if (!constraint_result) {
513 return JNI_EINVAL;
514 }
515
516 if (PauseAtStartup) {
517 os::pause();
518 }
519
520 HOTSPOT_VM_INIT_BEGIN();
521
522 // Timing (must come after argument parsing)
523 TraceTime timer("Create VM", TRACETIME_LOG(Info, startuptime));
524
525 // Initialize the os module after parsing the args
526 jint os_init_2_result = os::init_2();
527 if (os_init_2_result != JNI_OK) return os_init_2_result;
528
529 #ifdef CAN_SHOW_REGISTERS_ON_ASSERT
530 // Initialize assert poison page mechanism.
531 if (ShowRegistersOnAssert) {
532 initialize_assert_poison();
533 }
534 #endif // CAN_SHOW_REGISTERS_ON_ASSERT
535
536 SafepointMechanism::initialize();
537
538 jint adjust_after_os_result = Arguments::adjust_after_os();
539 if (adjust_after_os_result != JNI_OK) return adjust_after_os_result;
540
541 // Initialize output stream logging
542 ostream_init_log();
543
544 // Launch -agentlib/-agentpath and converted -Xrun agents
545 JvmtiAgentList::load_agents();
546
547 // Initialize Threads state
548 _number_of_threads = 0;
549 _number_of_non_daemon_threads = 0;
550
551 // Initialize global data structures and create system classes in heap
552 vm_init_globals();
553
554 #if INCLUDE_JVMCI
555 if (JVMCICounterSize > 0) {
556 JavaThread::_jvmci_old_thread_counters = NEW_C_HEAP_ARRAY(jlong, JVMCICounterSize, mtJVMCI);
557 memset(JavaThread::_jvmci_old_thread_counters, 0, sizeof(jlong) * JVMCICounterSize);
558 } else {
559 JavaThread::_jvmci_old_thread_counters = nullptr;
560 }
561 #endif // INCLUDE_JVMCI
562
563 // Initialize OopStorage for threadObj
564 JavaThread::_thread_oop_storage = OopStorageSet::create_strong("Thread OopStorage", mtThread);
565
566 // Attach the main thread to this os thread
567 JavaThread* main_thread = new JavaThread();
568 main_thread->set_thread_state(_thread_in_vm);
569 main_thread->initialize_thread_current();
570 // Once mutexes and main_thread are ready, we can use NmtVirtualMemoryLocker.
571 MemTracker::NmtVirtualMemoryLocker::set_safe_to_use();
572 // must do this before set_active_handles
573 main_thread->record_stack_base_and_size();
574 main_thread->register_thread_stack_with_NMT();
575 main_thread->set_active_handles(JNIHandleBlock::allocate_block());
576 MACOS_AARCH64_ONLY(main_thread->init_wx());
577
578 // Set the _monitor_owner_id now since we will run Java code before the Thread instance
579 // is even created. The same value will be assigned to the Thread instance on init.
580 main_thread->set_monitor_owner_id(ThreadIdentifier::next());
581
582 if (!Thread::set_as_starting_thread(main_thread)) {
583 vm_shutdown_during_initialization(
584 "Failed necessary internal allocation. Out of swap space");
585 main_thread->smr_delete();
586 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
587 return JNI_ENOMEM;
588 }
589
590 JFR_ONLY(Jfr::initialize_main_thread(main_thread);)
591
592 // Enable guard page *after* os::create_main_thread(), otherwise it would
593 // crash Linux VM, see notes in os_linux.cpp.
594 main_thread->stack_overflow_state()->create_stack_guard_pages();
595
596 // Initialize Java-Level synchronization subsystem
597 ObjectMonitor::Initialize();
598 ObjectSynchronizer::initialize();
599
600 // Initialize global modules
601 jint status = init_globals();
602 if (status != JNI_OK) {
603 main_thread->smr_delete();
604 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
605 return status;
606 }
607
608 // Have the WatcherThread read the release file in the background.
609 ReadReleaseFileTask* read_task = new ReadReleaseFileTask();
610 read_task->enroll();
611
612 // Create WatcherThread as soon as we can since we need it in case
613 // of hangs during error reporting.
614 WatcherThread::start();
615
616 // Add main_thread to threads list to finish barrier setup with
617 // on_thread_attach. Should be before starting to build Java objects in
618 // init_globals2, which invokes barriers.
619 {
620 MutexLocker mu(Threads_lock);
621 Threads::add(main_thread);
622 }
623
624 status = init_globals2();
625 if (status != JNI_OK) {
626 Threads::remove(main_thread, false);
627 // It is possible that we managed to fully initialize Universe but have then
628 // failed by throwing an exception. In that case our caller JNI_CreateJavaVM
629 // will want to report it, so we can't delete the main thread.
630 if (!main_thread->has_pending_exception()) {
631 main_thread->smr_delete();
632 }
633 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
634 return status;
635 }
636
637 ObjectMonitor::Initialize2();
638
639 JFR_ONLY(Jfr::on_create_vm_1();)
640
641 // Should be done after the heap is fully created
642 main_thread->cache_global_variables();
643
644 // Any JVMTI raw monitors entered in onload will transition into
645 // real raw monitor. VM is setup enough here for raw monitor enter.
646 JvmtiExport::transition_pending_onload_raw_monitors();
647
648 // Create the VMThread
649 { TraceTime timer("Start VMThread", TRACETIME_LOG(Info, startuptime));
650
651 VMThread::create();
652 VMThread* vmthread = VMThread::vm_thread();
653
654 if (!os::create_thread(vmthread, os::vm_thread)) {
655 vm_exit_during_initialization("Cannot create VM thread. "
656 "Out of system resources.");
657 }
658
659 // Wait for the VM thread to become ready, and VMThread::run to initialize
660 // Monitors can have spurious returns, must always check another state flag
661 {
662 MonitorLocker ml(Notify_lock);
663 os::start_thread(vmthread);
664 while (!vmthread->is_running()) {
665 ml.wait();
666 }
667 }
668 }
669
670 assert(Universe::is_fully_initialized(), "not initialized");
671 if (VerifyDuringStartup) {
672 // Make sure we're starting with a clean slate.
673 VM_Verify verify_op;
674 VMThread::execute(&verify_op);
675 }
676
677 // We need this to update the java.vm.info property in case any flags used
678 // to initially define it have been changed. This is needed for both CDS
679 // since UseSharedSpaces may be changed after java.vm.info
680 // is initially computed. See Abstract_VM_Version::vm_info_string().
681 // This update must happen before we initialize the java classes, but
682 // after any initialization logic that might modify the flags.
683 Arguments::update_vm_info_property(VM_Version::vm_info_string());
684
685 JavaThread* THREAD = JavaThread::current(); // For exception macros.
686 HandleMark hm(THREAD);
687
688 // Always call even when there are not JVMTI environments yet, since environments
689 // may be attached late and JVMTI must track phases of VM execution
690 JvmtiExport::enter_early_start_phase();
691
692 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
693 JvmtiExport::post_early_vm_start();
694
695 // Launch -Xrun agents early if EagerXrunInit is set
696 if (EagerXrunInit) {
697 JvmtiAgentList::load_xrun_agents();
698 }
699
700 initialize_java_lang_classes(main_thread, CHECK_JNI_ERR);
701
702 quicken_jni_functions();
703
704 // No more stub generation allowed after that point.
705 StubCodeDesc::freeze();
706
707 #ifdef ADDRESS_SANITIZER
708 Asan::initialize();
709 #endif
710
711 // Set flag that basic initialization has completed. Used by exceptions and various
712 // debug stuff, that does not work until all basic classes have been initialized.
713 set_init_completed();
714
715 LogConfiguration::post_initialize();
716 Metaspace::post_initialize();
717 MutexLockerImpl::post_initialize();
718
719 HOTSPOT_VM_INIT_END();
720
721 // record VM initialization completion time
722 #if INCLUDE_MANAGEMENT
723 Management::record_vm_init_completed();
724 #endif // INCLUDE_MANAGEMENT
725
726 log_info(os)("Initialized VM with process ID %d", os::current_process_id());
727
728 if (!FLAG_IS_DEFAULT(CreateCoredumpOnCrash) && CreateCoredumpOnCrash) {
729 char buffer[2*JVM_MAXPATHLEN];
730 os::check_core_dump_prerequisites(buffer, sizeof(buffer), true);
731 }
732
733 // Signal Dispatcher needs to be started before VMInit event is posted
734 os::initialize_jdk_signal_support(CHECK_JNI_ERR);
735
736 // Start Attach Listener if +StartAttachListener or it can't be started lazily
737 if (!DisableAttachMechanism) {
738 AttachListener::vm_start();
739 if (StartAttachListener || AttachListener::init_at_startup()) {
740 AttachListener::init();
741 }
742 }
743
744 // Launch -Xrun agents if EagerXrunInit is not set.
745 if (!EagerXrunInit) {
746 JvmtiAgentList::load_xrun_agents();
747 }
748
749 Arena::start_chunk_pool_cleaner_task();
750
751 // Start the service thread
752 // The service thread enqueues JVMTI deferred events and does various hashtable
753 // and other cleanups. Needs to start before the compilers start posting events.
754 ServiceThread::initialize();
755
756 if (CDSConfig::is_using_aot_linked_classes()) {
757 nmethod::post_delayed_compiled_method_load_events();
758 }
759
760 // Start the monitor deflation thread:
761 MonitorDeflationThread::initialize();
762
763 // initialize compiler(s)
764 #if defined(COMPILER1) || COMPILER2_OR_JVMCI
765 bool init_compilation = true;
766 #if INCLUDE_JVMCI
767 bool force_JVMCI_initialization = false;
768 if (EnableJVMCI) {
769 // Initialize JVMCI eagerly when it is explicitly requested.
770 // Or when JVMCILibDumpJNIConfig or JVMCIPrintProperties is enabled.
771 force_JVMCI_initialization = EagerJVMCI || JVMCIPrintProperties || JVMCILibDumpJNIConfig;
772 if (!force_JVMCI_initialization && UseJVMCICompiler && !UseJVMCINativeLibrary && (!UseInterpreter || !BackgroundCompilation)) {
773 // Force initialization of jarjvmci otherwise requests for blocking
774 // compilations will not actually block until jarjvmci is initialized.
775 force_JVMCI_initialization = true;
776 }
777 if (JVMCIPrintProperties || JVMCILibDumpJNIConfig) {
778 // Both JVMCILibDumpJNIConfig and JVMCIPrintProperties exit the VM
779 // so compilation should be disabled. This prevents dumping or
780 // printing from happening more than once.
781 init_compilation = false;
782 }
783 }
784 #endif
785 if (init_compilation) {
786 CompileBroker::compilation_init(CHECK_JNI_ERR);
787 }
788 #endif
789
790 if (CDSConfig::is_using_aot_linked_classes()) {
791 SystemDictionary::restore_archived_method_handle_intrinsics();
792 AOTLinkedClassBulkLoader::init_javabase_classes(THREAD);
793 }
794
795 // Start string deduplication thread if requested.
796 if (StringDedup::is_enabled()) {
797 StringDedup::start();
798 }
799
800 // Pre-initialize some JSR292 core classes to avoid deadlock during class loading.
801 // It is done after compilers are initialized, because otherwise compilations of
802 // signature polymorphic MH intrinsics can be missed
803 // (see SystemDictionary::find_method_handle_intrinsic).
804 initialize_jsr292_core_classes(CHECK_JNI_ERR);
805
806 // This will initialize the module system. Only java.base classes can be
807 // loaded until phase 2 completes
808 call_initPhase2(CHECK_JNI_ERR);
809
810 if (CDSConfig::is_using_aot_linked_classes()) {
811 AOTLinkedClassBulkLoader::init_non_javabase_classes(THREAD);
812 }
813 #ifndef PRODUCT
814 HeapShared::initialize_test_class_from_archive(THREAD);
815 #endif
816
817 JFR_ONLY(Jfr::on_create_vm_2();)
818
819 // Always call even when there are not JVMTI environments yet, since environments
820 // may be attached late and JVMTI must track phases of VM execution
821 JvmtiExport::enter_start_phase();
822
823 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
824 JvmtiExport::post_vm_start();
825
826 // Final system initialization including security manager and system class loader
827 call_initPhase3(CHECK_JNI_ERR);
828
829 // cache the system and platform class loaders
830 SystemDictionary::compute_java_loaders(CHECK_JNI_ERR);
831
832 // Initiate replay training processing once preloading is over.
833 CompileBroker::init_training_replay();
834
835 AOTLinkedClassBulkLoader::replay_training_at_init_for_preloaded_classes(CHECK_JNI_ERR);
836
837 if (Continuations::enabled()) {
838 // Initialize Continuation class now so that failure to create enterSpecial/doYield
839 // special nmethods due to limited CodeCache size can be treated as a fatal error at
840 // startup with the proper message that CodeCache size is too small.
841 initialize_class(vmSymbols::jdk_internal_vm_Continuation(), CHECK_JNI_ERR);
842 }
843
844 if (NativeHeapTrimmer::enabled()) {
845 NativeHeapTrimmer::initialize();
846 }
847
848 // Always call even when there are not JVMTI environments yet, since environments
849 // may be attached late and JVMTI must track phases of VM execution
850 JvmtiExport::enter_live_phase();
851
852 // Make perfmemory accessible
853 PerfMemory::set_accessible(true);
854
855 // Notify JVMTI agents that VM initialization is complete - nop if no agents.
856 JvmtiExport::post_vm_initialized();
857
858 #if INCLUDE_JVMCI
859 if (force_JVMCI_initialization) {
860 JVMCI::initialize_compiler_in_create_vm(CHECK_JNI_ERR);
861 }
862 #endif
863
864 JFR_ONLY(Jfr::on_create_vm_3();)
865
866 #if INCLUDE_MANAGEMENT
867 bool start_agent = true;
868 #if INCLUDE_CDS
869 start_agent = !CDSConfig::is_dumping_final_static_archive();
870 if (!start_agent) {
871 log_info(aot)("Not starting management agent during creation of AOT cache.");
872 }
873 #endif // INCLUDE_CDS
874 if (start_agent) {
875 Management::initialize(THREAD);
876
877 if (HAS_PENDING_EXCEPTION) {
878 // management agent fails to start possibly due to
879 // configuration problem and is responsible for printing
880 // stack trace if appropriate. Simply exit VM.
881 vm_exit(1);
882 }
883 }
884 #endif // INCLUDE_MANAGEMENT
885
886 if (UsePerfData) PerfDataManager::create_misc_perfdata();
887 if (CheckJNICalls) JniPeriodicChecker::engage();
888
889 call_postVMInitHook(THREAD);
890 // The Java side of PostVMInitHook.run must deal with all
891 // exceptions and provide means of diagnosis.
892 if (HAS_PENDING_EXCEPTION) {
893 CLEAR_PENDING_EXCEPTION;
894 }
895
896 // Let WatcherThread run all registered periodic tasks now.
897 // NOTE: All PeriodicTasks should be registered by now. If they
898 // aren't, late joiners might appear to start slowly (we might
899 // take a while to process their first tick).
900 WatcherThread::run_all_tasks();
901
902 create_vm_timer.end();
903 #ifdef ASSERT
904 _vm_complete = true;
905 #endif
906
907 if (CDSConfig::is_dumping_classic_static_archive()) {
908 // Classic -Xshare:dump, aka "old workflow"
909 AOTMetaspace::dump_static_archive(CHECK_JNI_ERR);
910 } else if (CDSConfig::is_dumping_final_static_archive()) {
911 tty->print_cr("Reading AOTConfiguration %s and writing AOTCache %s", AOTConfiguration, AOTCache);
912 AOTMetaspace::dump_static_archive(CHECK_JNI_ERR);
913 }
914
915 if (log_is_enabled(Info, perf, class, link)) {
916 LogStreamHandle(Info, perf, class, link) log;
917 log.print_cr("At VM initialization completion:");
918 ClassLoader::print_counters(&log);
919 }
920
921 return JNI_OK;
922 }
923
924 // Threads::destroy_vm() is normally called from jni_DestroyJavaVM() when
925 // the program falls off the end of main(). Another VM exit path is through
926 // vm_exit(), when the program calls System.exit() to return a value, or when
927 // there is a serious error in VM.
928 // These two separate shutdown paths are not exactly the same, but they share
929 // Shutdown.shutdown() at Java level and before_exit() and VM_Exit op at VM level.
930 //
931 // Shutdown sequence:
932 // + Shutdown native memory tracking if it is on
933 // + Wait until we are the last non-daemon thread to execute
934 // <-- every thing is still working at this moment -->
935 // + Call java.lang.Shutdown.shutdown(), which will invoke Java level
936 // shutdown hooks
937 // + Call before_exit(), prepare for VM exit
938 // > run VM level shutdown hooks (they are registered through JVM_OnExit(),
939 // currently the only user of this mechanism is File.deleteOnExit())
940 // > stop watcher thread,
941 // post thread end and vm death events to JVMTI,
942 // stop signal thread
943 // + Call JavaThread::exit(), it will:
944 // > release JNI handle blocks, remove stack guard pages
945 // > remove this thread from Threads list
946 // <-- no more Java code from this thread after this point -->
947 // + Stop VM thread, it will bring the remaining VM to a safepoint and stop
948 // the compiler threads at safepoint
949 // <-- do not use anything that could get blocked by Safepoint -->
950 // + Disable tracing at JNI/JVM barriers
951 // + Set _vm_exited flag for threads that are still running native code
952 // + Call exit_globals()
953 // > deletes tty
954 // > deletes PerfMemory resources
955 // + Delete this thread
956 // + Return to caller
957
958 void Threads::destroy_vm() {
959 JavaThread* thread = JavaThread::current();
960
961 #ifdef ASSERT
962 _vm_complete = false;
963 #endif
964 // Wait until we are the last non-daemon thread to execute, or
965 // if we are a daemon then wait until the last non-daemon thread has
966 // executed.
967 bool daemon = java_lang_Thread::is_daemon(thread->threadObj());
968 int expected = daemon ? 0 : 1;
969 {
970 MonitorLocker nu(Threads_lock);
971 while (Threads::number_of_non_daemon_threads() > expected)
972 // This wait should make safepoint checks, wait without a timeout.
973 nu.wait(0);
974 }
975
976 EventShutdown e;
977 if (e.should_commit()) {
978 e.set_reason("No remaining non-daemon Java threads");
979 e.commit();
980 }
981
982 // Hang forever on exit if we are reporting an error.
983 if (ShowMessageBoxOnError && VMError::is_error_reported()) {
984 os::infinite_sleep();
985 }
986 os::wait_for_keypress_at_exit();
987
988 // run Java level shutdown hooks
989 thread->invoke_shutdown_hooks();
990
991 before_exit(thread);
992
993 thread->exit(true);
994
995 // We are no longer on the main thread list but could still be in a
996 // secondary list where another thread may try to interact with us.
997 // So wait until all such interactions are complete before we bring
998 // the VM to the termination safepoint. Normally this would be done
999 // using thread->smr_delete() below where we delete the thread, but
1000 // we can't call that after the termination safepoint is active as
1001 // we will deadlock on the Threads_lock. Once all interactions are
1002 // complete it is safe to directly delete the thread at any time.
1003 ThreadsSMRSupport::wait_until_not_protected(thread);
1004
1005 // Stop VM thread.
1006 {
1007 // 4945125 The vm thread comes to a safepoint during exit.
1008 // GC vm_operations can get caught at the safepoint, and the
1009 // heap is unparseable if they are caught. Grab the Heap_lock
1010 // to prevent this. The GC vm_operations will not be able to
1011 // queue until after the vm thread is dead. After this point,
1012 // we'll never emerge out of the safepoint before the VM exits.
1013 // Assert that the thread is terminated so that acquiring the
1014 // Heap_lock doesn't cause the terminated thread to participate in
1015 // the safepoint protocol.
1016
1017 assert(thread->is_terminated(), "must be terminated here");
1018 MutexLocker ml(Heap_lock);
1019
1020 VMThread::wait_for_vm_thread_exit();
1021 assert(SafepointSynchronize::is_at_safepoint(), "VM thread should exit at Safepoint");
1022 VMThread::destroy();
1023 }
1024
1025 // Now, all Java threads are gone except daemon threads. Daemon threads
1026 // running Java code or in VM are stopped by the Safepoint. However,
1027 // daemon threads executing native code are still running. But they
1028 // will be stopped at native=>Java/VM barriers. Note that we can't
1029 // simply kill or suspend them, as it is inherently deadlock-prone.
1030
1031 VM_Exit::set_vm_exited();
1032
1033 // Clean up ideal graph printers after the VMThread has started
1034 // the final safepoint which will block all the Compiler threads.
1035 // Note that this Thread has already logically exited so the
1036 // clean_up() function's use of a JavaThreadIteratorWithHandle
1037 // would be a problem except set_vm_exited() has remembered the
1038 // shutdown thread which is granted a policy exception.
1039 #if defined(COMPILER2) && !defined(PRODUCT)
1040 IdealGraphPrinter::clean_up();
1041 #endif
1042
1043 notify_vm_shutdown();
1044
1045 // exit_globals() will delete tty
1046 exit_globals();
1047
1048 // Deleting the shutdown thread here is safe. See comment on
1049 // wait_until_not_protected() above.
1050 delete thread;
1051
1052 #if INCLUDE_JVMCI
1053 if (JVMCICounterSize > 0) {
1054 FREE_C_HEAP_ARRAY(jlong, JavaThread::_jvmci_old_thread_counters);
1055 }
1056 #endif
1057
1058 LogConfiguration::finalize();
1059 }
1060
1061
1062 jboolean Threads::is_supported_jni_version_including_1_1(jint version) {
1063 if (version == JNI_VERSION_1_1) return JNI_TRUE;
1064 return is_supported_jni_version(version);
1065 }
1066
1067
1068 jboolean Threads::is_supported_jni_version(jint version) {
1069 if (version == JNI_VERSION_1_2) return JNI_TRUE;
1070 if (version == JNI_VERSION_1_4) return JNI_TRUE;
1071 if (version == JNI_VERSION_1_6) return JNI_TRUE;
1072 if (version == JNI_VERSION_1_8) return JNI_TRUE;
1073 if (version == JNI_VERSION_9) return JNI_TRUE;
1074 if (version == JNI_VERSION_10) return JNI_TRUE;
1075 if (version == JNI_VERSION_19) return JNI_TRUE;
1076 if (version == JNI_VERSION_20) return JNI_TRUE;
1077 if (version == JNI_VERSION_21) return JNI_TRUE;
1078 if (version == JNI_VERSION_24) return JNI_TRUE;
1079 return JNI_FALSE;
1080 }
1081
1082 void Threads::add(JavaThread* p, bool force_daemon) {
1083 // The threads lock must be owned at this point
1084 assert(Threads_lock->owned_by_self(), "must have threads lock");
1085 assert(p->monitor_owner_id() != 0, "should be set");
1086
1087 BarrierSet::barrier_set()->on_thread_attach(p);
1088
1089 // Once a JavaThread is added to the Threads list, smr_delete() has
1090 // to be used to delete it. Otherwise we can just delete it directly.
1091 p->set_on_thread_list();
1092
1093 _number_of_threads++;
1094 oop threadObj = p->threadObj();
1095 bool daemon = true;
1096 // Bootstrapping problem: threadObj can be null for initial
1097 // JavaThread (or for threads attached via JNI)
1098 if (!force_daemon &&
1099 (threadObj == nullptr || !java_lang_Thread::is_daemon(threadObj))) {
1100 _number_of_non_daemon_threads++;
1101 daemon = false;
1102 }
1103
1104 ThreadService::add_thread(p, daemon);
1105
1106 // Maintain fast thread list
1107 ThreadsSMRSupport::add_thread(p);
1108
1109 // Increase the ObjectMonitor ceiling for the new thread.
1110 ObjectSynchronizer::inc_in_use_list_ceiling();
1111
1112 // Possible GC point.
1113 Events::log(Thread::current(), "Thread added: " INTPTR_FORMAT, p2i(p));
1114
1115 // Make new thread known to active EscapeBarrier
1116 EscapeBarrier::thread_added(p);
1117 }
1118
1119 void Threads::remove(JavaThread* p, bool is_daemon) {
1120 // Extra scope needed for Thread_lock, so we can check
1121 // that we do not remove thread without safepoint code notice
1122 {
1123 ConditionalMutexLocker throttle_ml(ThreadsLockThrottle_lock, UseThreadsLockThrottleLock);
1124 MonitorLocker ml(Threads_lock);
1125
1126 if (ThreadIdTable::is_initialized()) {
1127 // This cleanup must be done before the current thread's GC barrier
1128 // is detached since we need to touch the threadObj oop.
1129 jlong tid = SharedRuntime::get_java_tid(p);
1130 ThreadIdTable::remove_thread(tid);
1131 }
1132
1133 // BarrierSet state must be destroyed after the last thread transition
1134 // before the thread terminates. Thread transitions result in calls to
1135 // StackWatermarkSet::on_safepoint(), which performs GC processing,
1136 // requiring the GC state to be alive.
1137 BarrierSet::barrier_set()->on_thread_detach(p);
1138 if (p->is_exiting()) {
1139 // If we got here via JavaThread::exit(), then we remember that the
1140 // thread's GC barrier has been detached. We don't do this when we get
1141 // here from another path, e.g., cleanup_failed_attach_current_thread().
1142 p->set_terminated(JavaThread::_thread_gc_barrier_detached);
1143 }
1144
1145 assert(ThreadsSMRSupport::get_java_thread_list()->includes(p), "p must be present");
1146
1147 // Maintain fast thread list
1148 ThreadsSMRSupport::remove_thread(p);
1149
1150 _number_of_threads--;
1151 if (!is_daemon) {
1152 _number_of_non_daemon_threads--;
1153
1154 // If this is the last non-daemon thread then we need to do
1155 // a notify on the Threads_lock so a thread waiting
1156 // on destroy_vm will wake up. But that thread could be a daemon
1157 // or non-daemon, so we notify for both the 0 and 1 case.
1158 if (number_of_non_daemon_threads() <= 1) {
1159 ml.notify_all();
1160 }
1161 }
1162 ThreadService::remove_thread(p, is_daemon);
1163
1164 // Make sure that safepoint code disregard this thread. This is needed since
1165 // the thread might mess around with locks after this point. This can cause it
1166 // to do callbacks into the safepoint code. However, the safepoint code is not aware
1167 // of this thread since it is removed from the queue.
1168 p->set_terminated(JavaThread::_thread_terminated);
1169
1170 // Notify threads waiting in EscapeBarriers
1171 EscapeBarrier::thread_removed(p);
1172 } // unlock Threads_lock and ThreadsLockThrottle_lock
1173
1174 // Reduce the ObjectMonitor ceiling for the exiting thread.
1175 ObjectSynchronizer::dec_in_use_list_ceiling();
1176
1177 // Since Events::log uses a lock, we grab it outside the Threads_lock
1178 Events::log(Thread::current(), "Thread exited: " INTPTR_FORMAT, p2i(p));
1179 }
1180
1181 // Operations on the Threads list for GC. These are not explicitly locked,
1182 // but the garbage collector must provide a safe context for them to run.
1183 // In particular, these things should never be called when the Threads_lock
1184 // is held by some other thread. (Note: the Safepoint abstraction also
1185 // uses the Threads_lock to guarantee this property. It also makes sure that
1186 // all threads gets blocked when exiting or starting).
1187
1188 void Threads::oops_do(OopClosure* f, NMethodClosure* cf) {
1189 ALL_JAVA_THREADS(p) {
1190 p->oops_do(f, cf);
1191 }
1192 VMThread::vm_thread()->oops_do(f, cf);
1193 }
1194
1195 void Threads::change_thread_claim_token() {
1196 if (++_thread_claim_token == 0) {
1197 // On overflow of the token counter, there is a risk of future
1198 // collisions between a new global token value and a stale token
1199 // for a thread, because not all iterations visit all threads.
1200 // (Though it's pretty much a theoretical concern for non-trivial
1201 // token counter sizes.) To deal with the possibility, reset all
1202 // the thread tokens to zero on global token overflow.
1203 struct ResetClaims : public ThreadClosure {
1204 virtual void do_thread(Thread* t) {
1205 t->claim_threads_do(false, 0);
1206 }
1207 } reset_claims;
1208 Threads::threads_do(&reset_claims);
1209 // On overflow, update the global token to non-zero, to
1210 // avoid the special "never claimed" initial thread value.
1211 _thread_claim_token = 1;
1212 }
1213 }
1214
1215 #ifdef ASSERT
1216 static void assert_thread_claimed(const char* kind, Thread* t, uintx expected) {
1217 const uintx token = t->threads_do_token();
1218 assert(token == expected,
1219 "%s " PTR_FORMAT " has incorrect value %zu != %zu",
1220 kind, p2i(t), token, expected);
1221 }
1222
1223 void Threads::assert_all_threads_claimed() {
1224 ALL_JAVA_THREADS(p) {
1225 assert_thread_claimed("JavaThread", p, _thread_claim_token);
1226 }
1227
1228 struct NJTClaimedVerifierClosure : public ThreadClosure {
1229 uintx _thread_claim_token;
1230
1231 NJTClaimedVerifierClosure(uintx thread_claim_token) : ThreadClosure(), _thread_claim_token(thread_claim_token) { }
1232
1233 virtual void do_thread(Thread* thread) override {
1234 assert_thread_claimed("Non-JavaThread", VMThread::vm_thread(), _thread_claim_token);
1235 }
1236 } tc(_thread_claim_token);
1237
1238 non_java_threads_do(&tc);
1239 }
1240 #endif // ASSERT
1241
1242 class ParallelOopsDoThreadClosure : public ThreadClosure {
1243 private:
1244 OopClosure* _f;
1245 NMethodClosure* _cf;
1246 public:
1247 ParallelOopsDoThreadClosure(OopClosure* f, NMethodClosure* cf) : _f(f), _cf(cf) {}
1248 void do_thread(Thread* t) {
1249 t->oops_do(_f, _cf);
1250 }
1251 };
1252
1253 void Threads::possibly_parallel_oops_do(bool is_par, OopClosure* f, NMethodClosure* cf) {
1254 ParallelOopsDoThreadClosure tc(f, cf);
1255 possibly_parallel_threads_do(is_par, &tc);
1256 }
1257
1258 void Threads::metadata_do(MetadataClosure* f) {
1259 ALL_JAVA_THREADS(p) {
1260 p->metadata_do(f);
1261 }
1262 }
1263
1264 class ThreadHandlesClosure : public ThreadClosure {
1265 void (*_f)(Metadata*);
1266 public:
1267 ThreadHandlesClosure(void f(Metadata*)) : _f(f) {}
1268 virtual void do_thread(Thread* thread) {
1269 thread->metadata_handles_do(_f);
1270 }
1271 };
1272
1273 void Threads::metadata_handles_do(void f(Metadata*)) {
1274 // Only walk the Handles in Thread.
1275 ThreadHandlesClosure handles_closure(f);
1276 threads_do(&handles_closure);
1277 }
1278
1279 #if INCLUDE_JVMTI
1280 // Get Java threads that are waiting to enter or re-enter the specified monitor.
1281 // Java threads that are executing mounted virtual threads are not included.
1282 GrowableArray<JavaThread*>* Threads::get_pending_threads(ThreadsList * t_list,
1283 int count,
1284 address monitor) {
1285 assert(Thread::current()->is_VM_thread(), "Must be the VM thread");
1286 GrowableArray<JavaThread*>* result = new GrowableArray<JavaThread*>(count);
1287
1288 int i = 0;
1289 for (JavaThread* p : *t_list) {
1290 if (!p->can_call_java()) continue;
1291
1292 oop thread_oop = JvmtiEnvBase::get_vthread_or_thread_oop(p);
1293 if (thread_oop->is_a(vmClasses::BaseVirtualThread_klass())) {
1294 continue;
1295 }
1296 // The first stage of async deflation does not affect any field
1297 // used by this comparison so the ObjectMonitor* is usable here.
1298 address pending = (address)p->current_pending_monitor();
1299 address waiting = (address)p->current_waiting_monitor();
1300 // do not include virtual threads to the list
1301 jint state = JvmtiEnvBase::get_thread_state(thread_oop, p);
1302 if (pending == monitor || (waiting == monitor &&
1303 (state & JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER))
1304 ) { // found a match
1305 if (i < count) result->append(p); // save the first count matches
1306 i++;
1307 }
1308 }
1309
1310 return result;
1311 }
1312 #endif // INCLUDE_JVMTI
1313
1314 JavaThread* Threads::owning_thread_from_object(ThreadsList * t_list, oop obj) {
1315 for (JavaThread* q : *t_list) {
1316 // Need to start processing before accessing oops in the thread.
1317 StackWatermark* watermark = StackWatermarkSet::get(q, StackWatermarkKind::gc);
1318 if (watermark != nullptr) {
1319 watermark->start_processing();
1320 }
1321
1322 if (q->lock_stack().contains(obj)) {
1323 return q;
1324 }
1325 }
1326 return nullptr;
1327 }
1328
1329 JavaThread* Threads::owning_thread_from_monitor(ThreadsList* t_list, ObjectMonitor* monitor) {
1330 if (monitor->has_anonymous_owner()) {
1331 return owning_thread_from_object(t_list, monitor->object());
1332 } else {
1333 JavaThread* the_owner = nullptr;
1334 for (JavaThread* q : *t_list) {
1335 if (monitor->has_owner(q)) {
1336 the_owner = q;
1337 break;
1338 }
1339 }
1340 return the_owner;
1341 }
1342 }
1343
1344 class PrintOnClosure : public ThreadClosure {
1345 private:
1346 outputStream* _st;
1347
1348 public:
1349 PrintOnClosure(outputStream* st) :
1350 _st(st) {}
1351
1352 virtual void do_thread(Thread* thread) {
1353 if (thread != nullptr) {
1354 thread->print_on(_st);
1355 _st->cr();
1356 }
1357 }
1358 };
1359
1360 // Threads::print_on() is called at safepoint by VM_PrintThreads operation.
1361 void Threads::print_on(outputStream* st, bool print_stacks,
1362 bool internal_format, bool print_concurrent_locks,
1363 bool print_extended_info) {
1364 char buf[32];
1365 st->print_raw_cr(os::local_time_string(buf, sizeof(buf)));
1366
1367 st->print_cr("Full thread dump %s (%s %s)",
1368 VM_Version::vm_name(),
1369 VM_Version::vm_release(),
1370 VM_Version::vm_info_string());
1371 JDK_Version::current().to_string(buf, sizeof(buf));
1372 const char* runtime_name = JDK_Version::runtime_name() != nullptr ?
1373 JDK_Version::runtime_name() : "";
1374 const char* runtime_version = JDK_Version::runtime_version() != nullptr ?
1375 JDK_Version::runtime_version() : "";
1376 const char* vendor_version = JDK_Version::runtime_vendor_version() != nullptr ?
1377 JDK_Version::runtime_vendor_version() : "";
1378 const char* jdk_debug_level = VM_Version::printable_jdk_debug_level() != nullptr ?
1379 VM_Version::printable_jdk_debug_level() : "";
1380
1381 st->print_cr(" JDK version: %s%s%s (%s) (%sbuild %s)", runtime_name,
1382 (*vendor_version != '\0') ? " " : "", vendor_version,
1383 buf, jdk_debug_level, runtime_version);
1384
1385 st->cr();
1386
1387 #if INCLUDE_SERVICES
1388 // Dump concurrent locks
1389 ConcurrentLocksDump concurrent_locks;
1390 if (print_concurrent_locks) {
1391 concurrent_locks.dump_at_safepoint();
1392 }
1393 #endif // INCLUDE_SERVICES
1394
1395 ThreadsSMRSupport::print_info_on(st);
1396 st->cr();
1397
1398 ALL_JAVA_THREADS(p) {
1399 ResourceMark rm;
1400 p->print_on(st, print_extended_info);
1401 if (print_stacks) {
1402 if (internal_format) {
1403 p->trace_stack();
1404 } else {
1405 p->print_stack_on(st);
1406 if (p->is_vthread_mounted()) {
1407 st->print_cr(" Mounted virtual thread #" INT64_FORMAT, java_lang_Thread::thread_id(p->vthread()));
1408 p->print_vthread_stack_on(st);
1409 }
1410 }
1411 }
1412 st->cr();
1413 #if INCLUDE_SERVICES
1414 if (print_concurrent_locks) {
1415 concurrent_locks.print_locks_on(p, st);
1416 }
1417 #endif // INCLUDE_SERVICES
1418 }
1419
1420 PrintOnClosure cl(st);
1421 non_java_threads_do(&cl);
1422
1423 st->flush();
1424 }
1425
1426 void Threads::print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
1427 int buflen, bool* found_current) {
1428 if (this_thread != nullptr) {
1429 bool is_current = (current == this_thread);
1430 *found_current = *found_current || is_current;
1431 st->print("%s", is_current ? "=>" : " ");
1432
1433 st->print(PTR_FORMAT, p2i(this_thread));
1434 st->print(" ");
1435 this_thread->print_on_error(st, buf, buflen);
1436 st->cr();
1437 }
1438 }
1439
1440 class PrintOnErrorClosure : public ThreadClosure {
1441 outputStream* _st;
1442 Thread* _current;
1443 char* _buf;
1444 int _buflen;
1445 bool* _found_current;
1446 unsigned _num_printed;
1447 public:
1448 PrintOnErrorClosure(outputStream* st, Thread* current, char* buf,
1449 int buflen, bool* found_current) :
1450 _st(st), _current(current), _buf(buf), _buflen(buflen), _found_current(found_current),
1451 _num_printed(0) {}
1452
1453 virtual void do_thread(Thread* thread) {
1454 _num_printed++;
1455 Threads::print_on_error(thread, _st, _current, _buf, _buflen, _found_current);
1456 }
1457
1458 unsigned num_printed() const { return _num_printed; }
1459 };
1460
1461 // Threads::print_on_error() is called by fatal error handler. It's possible
1462 // that VM is not at safepoint and/or current thread is inside signal handler.
1463 // Don't print stack trace, as the stack may not be walkable. Don't allocate
1464 // memory (even in resource area), it might deadlock the error handler.
1465 void Threads::print_on_error(outputStream* st, Thread* current, char* buf,
1466 int buflen) {
1467 ThreadsSMRSupport::print_info_on(st);
1468 st->cr();
1469
1470 bool found_current = false;
1471 st->print_cr("Java Threads: ( => current thread )");
1472 unsigned num_java = 0;
1473 ALL_JAVA_THREADS(thread) {
1474 print_on_error(thread, st, current, buf, buflen, &found_current);
1475 num_java++;
1476 }
1477 st->print_cr("Total: %u", num_java);
1478 st->cr();
1479
1480 st->print_cr("Other Threads:");
1481 unsigned num_other = ((VMThread::vm_thread() != nullptr) ? 1 : 0) +
1482 ((WatcherThread::watcher_thread() != nullptr) ? 1 : 0) +
1483 ((AsyncLogWriter::instance() != nullptr) ? 1 : 0);
1484 print_on_error(VMThread::vm_thread(), st, current, buf, buflen, &found_current);
1485 print_on_error(WatcherThread::watcher_thread(), st, current, buf, buflen, &found_current);
1486 print_on_error(AsyncLogWriter::instance(), st, current, buf, buflen, &found_current);
1487
1488 if (Universe::heap() != nullptr) {
1489 PrintOnErrorClosure print_closure(st, current, buf, buflen, &found_current);
1490 Universe::heap()->gc_threads_do(&print_closure);
1491 num_other += print_closure.num_printed();
1492 }
1493
1494 if (!found_current) {
1495 st->cr();
1496 st->print("=>" PTR_FORMAT " (exited) ", p2i(current));
1497 current->print_on_error(st, buf, buflen);
1498 num_other++;
1499 st->cr();
1500 }
1501 st->print_cr("Total: %u", num_other);
1502 st->cr();
1503
1504 st->print_cr("Threads with active compile tasks:");
1505 unsigned num = print_threads_compiling(st, buf, buflen);
1506 st->print_cr("Total: %u", num);
1507 }
1508
1509 unsigned Threads::print_threads_compiling(outputStream* st, char* buf, int buflen, bool short_form) {
1510 unsigned num = 0;
1511 ALL_JAVA_THREADS(thread) {
1512 if (thread->is_Compiler_thread()) {
1513 CompilerThread* ct = (CompilerThread*) thread;
1514
1515 // Keep task in local variable for null check.
1516 // ct->_task might be set to null by concurring compiler thread
1517 // because it completed the compilation. The task is never freed,
1518 // though, just returned to a free list.
1519 CompileTask* task = ct->task();
1520 if (task != nullptr) {
1521 thread->print_name_on_error(st, buf, buflen);
1522 st->print(" ");
1523 task->print(st, nullptr, short_form, true);
1524 num++;
1525 }
1526 }
1527 }
1528 return num;
1529 }
1530
1531 void Threads::verify() {
1532 ALL_JAVA_THREADS(p) {
1533 p->verify();
1534 }
1535 VMThread* thread = VMThread::vm_thread();
1536 if (thread != nullptr) thread->verify();
1537 }