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_IdentityException(), CHECK);
418 initialize_class(vmSymbols::java_lang_IllegalArgumentException(), CHECK);
419 initialize_class(vmSymbols::java_lang_InternalError(), CHECK);
420 }
421
422 void Threads::initialize_jsr292_core_classes(TRAPS) {
423 TraceTime timer("Initialize java.lang.invoke classes", TRACETIME_LOG(Info, startuptime));
424
425 initialize_class(vmSymbols::java_lang_invoke_MethodHandle(), CHECK);
426 initialize_class(vmSymbols::java_lang_invoke_ResolvedMethodName(), CHECK);
427 initialize_class(vmSymbols::java_lang_invoke_MemberName(), CHECK);
428 initialize_class(vmSymbols::java_lang_invoke_MethodHandleNatives(), CHECK);
429
430 if (UseSharedSpaces) {
431 HeapShared::initialize_java_lang_invoke(CHECK);
432 }
433 }
434
435 // One-shot PeriodicTask subclass for reading the release file
436 class ReadReleaseFileTask : public PeriodicTask {
437 public:
438 ReadReleaseFileTask() : PeriodicTask(100) {}
439
440 virtual void task() {
441 os::read_image_release_file();
442
443 // Reclaim our storage and disenroll ourself.
444 delete this;
445 }
446 };
447
448 jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) {
449 extern void JDK_Version_init();
450
451 // Preinitialize version info.
452 VM_Version::early_initialize();
453
454 // Check version
455 if (!is_supported_jni_version(args->version)) return JNI_EVERSION;
456
457 // Deferred "static" initialization
458 NonJavaThread::init();
459
460 // Initialize library-based TLS
461 ThreadLocalStorage::init();
462
463 // Initialize the output stream module
464 ostream_init();
465
466 // Process java launcher properties.
467 Arguments::process_sun_java_launcher_properties(args);
468
469 // Initialize the os module
470 os::init();
471
472 // Initialize memory pools
473 Arena::initialize_chunk_pool();
474
475 MACOS_AARCH64_ONLY(os::current_thread_enable_wx(WXWrite));
476
477 // Record VM creation timing statistics
478 TraceVmCreationTime create_vm_timer;
479 create_vm_timer.start();
480
481 // Initialize system properties.
482 Arguments::init_system_properties();
483
484 // So that JDK version can be used as a discriminator when parsing arguments
485 JDK_Version_init();
486
487 // Update/Initialize System properties after JDK version number is known
488 Arguments::init_version_specific_system_properties();
489
490 // Make sure to initialize log configuration *before* parsing arguments
491 LogConfiguration::initialize(create_vm_timer.begin_time());
492
493 // Parse arguments
494 // Note: this internally calls os::init_container_support()
495 jint parse_result = Arguments::parse(args);
496 if (parse_result != JNI_OK) return parse_result;
497
498 // Initialize NMT right after argument parsing to keep the pre-NMT-init window small.
499 MemTracker::initialize();
500
501 os::init_before_ergo();
502
503 jint ergo_result = Arguments::apply_ergo();
504 if (ergo_result != JNI_OK) return ergo_result;
505
506 // Final check of all ranges after ergonomics which may change values.
507 if (!JVMFlagLimit::check_all_ranges()) {
508 return JNI_EINVAL;
509 }
510
511 // Final check of all 'AfterErgo' constraints after ergonomics which may change values.
512 bool constraint_result = JVMFlagLimit::check_all_constraints(JVMFlagConstraintPhase::AfterErgo);
513 if (!constraint_result) {
514 return JNI_EINVAL;
515 }
516
517 if (PauseAtStartup) {
518 os::pause();
519 }
520
521 HOTSPOT_VM_INIT_BEGIN();
522
523 // Timing (must come after argument parsing)
524 TraceTime timer("Create VM", TRACETIME_LOG(Info, startuptime));
525
526 // Initialize the os module after parsing the args
527 jint os_init_2_result = os::init_2();
528 if (os_init_2_result != JNI_OK) return os_init_2_result;
529
530 #ifdef CAN_SHOW_REGISTERS_ON_ASSERT
531 // Initialize assert poison page mechanism.
532 if (ShowRegistersOnAssert) {
533 initialize_assert_poison();
534 }
535 #endif // CAN_SHOW_REGISTERS_ON_ASSERT
536
537 SafepointMechanism::initialize();
538
539 jint adjust_after_os_result = Arguments::adjust_after_os();
540 if (adjust_after_os_result != JNI_OK) return adjust_after_os_result;
541
542 // Initialize output stream logging
543 ostream_init_log();
544
545 // Launch -agentlib/-agentpath and converted -Xrun agents
546 JvmtiAgentList::load_agents();
547
548 // Initialize Threads state
549 _number_of_threads = 0;
550 _number_of_non_daemon_threads = 0;
551
552 // Initialize global data structures and create system classes in heap
553 vm_init_globals();
554
555 #if INCLUDE_JVMCI
556 if (JVMCICounterSize > 0) {
557 JavaThread::_jvmci_old_thread_counters = NEW_C_HEAP_ARRAY(jlong, JVMCICounterSize, mtJVMCI);
558 memset(JavaThread::_jvmci_old_thread_counters, 0, sizeof(jlong) * JVMCICounterSize);
559 } else {
560 JavaThread::_jvmci_old_thread_counters = nullptr;
561 }
562 #endif // INCLUDE_JVMCI
563
564 // Initialize OopStorage for threadObj
565 JavaThread::_thread_oop_storage = OopStorageSet::create_strong("Thread OopStorage", mtThread);
566
567 // Attach the main thread to this os thread
568 JavaThread* main_thread = new JavaThread();
569 main_thread->set_thread_state(_thread_in_vm);
570 main_thread->initialize_thread_current();
571 // Once mutexes and main_thread are ready, we can use NmtVirtualMemoryLocker.
572 MemTracker::NmtVirtualMemoryLocker::set_safe_to_use();
573 // must do this before set_active_handles
574 main_thread->record_stack_base_and_size();
575 main_thread->register_thread_stack_with_NMT();
576 main_thread->set_active_handles(JNIHandleBlock::allocate_block());
577 MACOS_AARCH64_ONLY(main_thread->init_wx());
578
579 // Set the _monitor_owner_id now since we will run Java code before the Thread instance
580 // is even created. The same value will be assigned to the Thread instance on init.
581 main_thread->set_monitor_owner_id(ThreadIdentifier::next());
582
583 if (!Thread::set_as_starting_thread(main_thread)) {
584 vm_shutdown_during_initialization(
585 "Failed necessary internal allocation. Out of swap space");
586 main_thread->smr_delete();
587 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
588 return JNI_ENOMEM;
589 }
590
591 JFR_ONLY(Jfr::initialize_main_thread(main_thread);)
592
593 // Enable guard page *after* os::create_main_thread(), otherwise it would
594 // crash Linux VM, see notes in os_linux.cpp.
595 main_thread->stack_overflow_state()->create_stack_guard_pages();
596
597 // Initialize Java-Level synchronization subsystem
598 ObjectMonitor::Initialize();
599 ObjectSynchronizer::initialize();
600
601 // Initialize global modules
602 jint status = init_globals();
603 if (status != JNI_OK) {
604 main_thread->smr_delete();
605 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
606 return status;
607 }
608
609 // Have the WatcherThread read the release file in the background.
610 ReadReleaseFileTask* read_task = new ReadReleaseFileTask();
611 read_task->enroll();
612
613 // Create WatcherThread as soon as we can since we need it in case
614 // of hangs during error reporting.
615 WatcherThread::start();
616
617 // Add main_thread to threads list to finish barrier setup with
618 // on_thread_attach. Should be before starting to build Java objects in
619 // init_globals2, which invokes barriers.
620 {
621 MutexLocker mu(Threads_lock);
622 Threads::add(main_thread);
623 }
624
625 status = init_globals2();
626 if (status != JNI_OK) {
627 Threads::remove(main_thread, false);
628 // It is possible that we managed to fully initialize Universe but have then
629 // failed by throwing an exception. In that case our caller JNI_CreateJavaVM
630 // will want to report it, so we can't delete the main thread.
631 if (!main_thread->has_pending_exception()) {
632 main_thread->smr_delete();
633 }
634 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
635 return status;
636 }
637
638 ObjectMonitor::Initialize2();
639
640 JFR_ONLY(Jfr::on_create_vm_1();)
641
642 // Should be done after the heap is fully created
643 main_thread->cache_global_variables();
644
645 // Any JVMTI raw monitors entered in onload will transition into
646 // real raw monitor. VM is setup enough here for raw monitor enter.
647 JvmtiExport::transition_pending_onload_raw_monitors();
648
649 // Create the VMThread
650 { TraceTime timer("Start VMThread", TRACETIME_LOG(Info, startuptime));
651
652 VMThread::create();
653 VMThread* vmthread = VMThread::vm_thread();
654
655 if (!os::create_thread(vmthread, os::vm_thread)) {
656 vm_exit_during_initialization("Cannot create VM thread. "
657 "Out of system resources.");
658 }
659
660 // Wait for the VM thread to become ready, and VMThread::run to initialize
661 // Monitors can have spurious returns, must always check another state flag
662 {
663 MonitorLocker ml(Notify_lock);
664 os::start_thread(vmthread);
665 while (!vmthread->is_running()) {
666 ml.wait();
667 }
668 }
669 }
670
671 assert(Universe::is_fully_initialized(), "not initialized");
672 if (VerifyDuringStartup) {
673 // Make sure we're starting with a clean slate.
674 VM_Verify verify_op;
675 VMThread::execute(&verify_op);
676 }
677
678 // We need this to update the java.vm.info property in case any flags used
679 // to initially define it have been changed. This is needed for both CDS
680 // since UseSharedSpaces may be changed after java.vm.info
681 // is initially computed. See Abstract_VM_Version::vm_info_string().
682 // This update must happen before we initialize the java classes, but
683 // after any initialization logic that might modify the flags.
684 Arguments::update_vm_info_property(VM_Version::vm_info_string());
685
686 JavaThread* THREAD = JavaThread::current(); // For exception macros.
687 HandleMark hm(THREAD);
688
689 // Always call even when there are not JVMTI environments yet, since environments
690 // may be attached late and JVMTI must track phases of VM execution
691 JvmtiExport::enter_early_start_phase();
692
693 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
694 JvmtiExport::post_early_vm_start();
695
696 // Launch -Xrun agents early if EagerXrunInit is set
697 if (EagerXrunInit) {
698 JvmtiAgentList::load_xrun_agents();
699 }
700
701 initialize_java_lang_classes(main_thread, CHECK_JNI_ERR);
702
703 quicken_jni_functions();
704
705 // No more stub generation allowed after that point.
706 StubCodeDesc::freeze();
707
708 #ifdef ADDRESS_SANITIZER
709 Asan::initialize();
710 #endif
711
712 // Set flag that basic initialization has completed. Used by exceptions and various
713 // debug stuff, that does not work until all basic classes have been initialized.
714 set_init_completed();
715
716 LogConfiguration::post_initialize();
717 Metaspace::post_initialize();
718 MutexLockerImpl::post_initialize();
719
720 HOTSPOT_VM_INIT_END();
721
722 // record VM initialization completion time
723 #if INCLUDE_MANAGEMENT
724 Management::record_vm_init_completed();
725 #endif // INCLUDE_MANAGEMENT
726
727 log_info(os)("Initialized VM with process ID %d", os::current_process_id());
728
729 if (!FLAG_IS_DEFAULT(CreateCoredumpOnCrash) && CreateCoredumpOnCrash) {
730 char buffer[2*JVM_MAXPATHLEN];
731 os::check_core_dump_prerequisites(buffer, sizeof(buffer), true);
732 }
733
734 // Signal Dispatcher needs to be started before VMInit event is posted
735 os::initialize_jdk_signal_support(CHECK_JNI_ERR);
736
737 // Start Attach Listener if +StartAttachListener or it can't be started lazily
738 if (!DisableAttachMechanism) {
739 AttachListener::vm_start();
740 if (StartAttachListener || AttachListener::init_at_startup()) {
741 AttachListener::init();
742 }
743 }
744
745 // Launch -Xrun agents if EagerXrunInit is not set.
746 if (!EagerXrunInit) {
747 JvmtiAgentList::load_xrun_agents();
748 }
749
750 Arena::start_chunk_pool_cleaner_task();
751
752 // Start the service thread
753 // The service thread enqueues JVMTI deferred events and does various hashtable
754 // and other cleanups. Needs to start before the compilers start posting events.
755 ServiceThread::initialize();
756
757 if (CDSConfig::is_using_aot_linked_classes()) {
758 nmethod::post_delayed_compiled_method_load_events();
759 }
760
761 // Start the monitor deflation thread:
762 MonitorDeflationThread::initialize();
763
764 // initialize compiler(s)
765 #if defined(COMPILER1) || COMPILER2_OR_JVMCI
766 bool init_compilation = true;
767 #if INCLUDE_JVMCI
768 bool force_JVMCI_initialization = false;
769 if (EnableJVMCI) {
770 // Initialize JVMCI eagerly when it is explicitly requested.
771 // Or when JVMCILibDumpJNIConfig or JVMCIPrintProperties is enabled.
772 force_JVMCI_initialization = EagerJVMCI || JVMCIPrintProperties || JVMCILibDumpJNIConfig;
773 if (!force_JVMCI_initialization && UseJVMCICompiler && !UseJVMCINativeLibrary && (!UseInterpreter || !BackgroundCompilation)) {
774 // Force initialization of jarjvmci otherwise requests for blocking
775 // compilations will not actually block until jarjvmci is initialized.
776 force_JVMCI_initialization = true;
777 }
778 if (JVMCIPrintProperties || JVMCILibDumpJNIConfig) {
779 // Both JVMCILibDumpJNIConfig and JVMCIPrintProperties exit the VM
780 // so compilation should be disabled. This prevents dumping or
781 // printing from happening more than once.
782 init_compilation = false;
783 }
784 }
785 #endif
786 if (init_compilation) {
787 CompileBroker::compilation_init(CHECK_JNI_ERR);
788 }
789 #endif
790
791 if (CDSConfig::is_using_aot_linked_classes()) {
792 SystemDictionary::restore_archived_method_handle_intrinsics();
793 AOTLinkedClassBulkLoader::init_javabase_classes(THREAD);
794 }
795
796 // Start string deduplication thread if requested.
797 if (StringDedup::is_enabled()) {
798 StringDedup::start();
799 }
800
801 // Pre-initialize some JSR292 core classes to avoid deadlock during class loading.
802 // It is done after compilers are initialized, because otherwise compilations of
803 // signature polymorphic MH intrinsics can be missed
804 // (see SystemDictionary::find_method_handle_intrinsic).
805 initialize_jsr292_core_classes(CHECK_JNI_ERR);
806
807 // This will initialize the module system. Only java.base classes can be
808 // loaded until phase 2 completes
809 call_initPhase2(CHECK_JNI_ERR);
810
811 if (CDSConfig::is_using_aot_linked_classes()) {
812 AOTLinkedClassBulkLoader::init_non_javabase_classes(THREAD);
813 }
814 #ifndef PRODUCT
815 HeapShared::initialize_test_class_from_archive(THREAD);
816 #endif
817
818 JFR_ONLY(Jfr::on_create_vm_2();)
819
820 // Always call even when there are not JVMTI environments yet, since environments
821 // may be attached late and JVMTI must track phases of VM execution
822 JvmtiExport::enter_start_phase();
823
824 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
825 JvmtiExport::post_vm_start();
826
827 // Final system initialization including security manager and system class loader
828 call_initPhase3(CHECK_JNI_ERR);
829
830 // cache the system and platform class loaders
831 SystemDictionary::compute_java_loaders(CHECK_JNI_ERR);
832
833 // Initiate replay training processing once preloading is over.
834 CompileBroker::init_training_replay();
835
836 AOTLinkedClassBulkLoader::replay_training_at_init_for_preloaded_classes(CHECK_JNI_ERR);
837
838 if (Continuations::enabled()) {
839 // Initialize Continuation class now so that failure to create enterSpecial/doYield
840 // special nmethods due to limited CodeCache size can be treated as a fatal error at
841 // startup with the proper message that CodeCache size is too small.
842 initialize_class(vmSymbols::jdk_internal_vm_Continuation(), CHECK_JNI_ERR);
843 }
844
845 if (NativeHeapTrimmer::enabled()) {
846 NativeHeapTrimmer::initialize();
847 }
848
849 // Always call even when there are not JVMTI environments yet, since environments
850 // may be attached late and JVMTI must track phases of VM execution
851 JvmtiExport::enter_live_phase();
852
853 // Make perfmemory accessible
854 PerfMemory::set_accessible(true);
855
856 // Notify JVMTI agents that VM initialization is complete - nop if no agents.
857 JvmtiExport::post_vm_initialized();
858
859 #if INCLUDE_JVMCI
860 if (force_JVMCI_initialization) {
861 JVMCI::initialize_compiler_in_create_vm(CHECK_JNI_ERR);
862 }
863 #endif
864
865 JFR_ONLY(Jfr::on_create_vm_3();)
866
867 #if INCLUDE_MANAGEMENT
868 bool start_agent = true;
869 #if INCLUDE_CDS
870 start_agent = !CDSConfig::is_dumping_final_static_archive();
871 if (!start_agent) {
872 log_info(aot)("Not starting management agent during creation of AOT cache.");
873 }
874 #endif // INCLUDE_CDS
875 if (start_agent) {
876 Management::initialize(THREAD);
877
878 if (HAS_PENDING_EXCEPTION) {
879 // management agent fails to start possibly due to
880 // configuration problem and is responsible for printing
881 // stack trace if appropriate. Simply exit VM.
882 vm_exit(1);
883 }
884 }
885 #endif // INCLUDE_MANAGEMENT
886
887 if (UsePerfData) PerfDataManager::create_misc_perfdata();
888 if (CheckJNICalls) JniPeriodicChecker::engage();
889
890 call_postVMInitHook(THREAD);
891 // The Java side of PostVMInitHook.run must deal with all
892 // exceptions and provide means of diagnosis.
893 if (HAS_PENDING_EXCEPTION) {
894 CLEAR_PENDING_EXCEPTION;
895 }
896
897 // Let WatcherThread run all registered periodic tasks now.
898 // NOTE: All PeriodicTasks should be registered by now. If they
899 // aren't, late joiners might appear to start slowly (we might
900 // take a while to process their first tick).
901 WatcherThread::run_all_tasks();
902
903 create_vm_timer.end();
904 #ifdef ASSERT
905 _vm_complete = true;
906 #endif
907
908 if (CDSConfig::is_dumping_classic_static_archive()) {
909 // Classic -Xshare:dump, aka "old workflow"
910 AOTMetaspace::dump_static_archive(CHECK_JNI_ERR);
911 } else if (CDSConfig::is_dumping_final_static_archive()) {
912 tty->print_cr("Reading AOTConfiguration %s and writing AOTCache %s", AOTConfiguration, AOTCache);
913 AOTMetaspace::dump_static_archive(CHECK_JNI_ERR);
914 }
915
916 if (log_is_enabled(Info, perf, class, link)) {
917 LogStreamHandle(Info, perf, class, link) log;
918 log.print_cr("At VM initialization completion:");
919 ClassLoader::print_counters(&log);
920 }
921
922 return JNI_OK;
923 }
924
925 // Threads::destroy_vm() is normally called from jni_DestroyJavaVM() when
926 // the program falls off the end of main(). Another VM exit path is through
927 // vm_exit(), when the program calls System.exit() to return a value, or when
928 // there is a serious error in VM.
929 // These two separate shutdown paths are not exactly the same, but they share
930 // Shutdown.shutdown() at Java level and before_exit() and VM_Exit op at VM level.
931 //
932 // Shutdown sequence:
933 // + Shutdown native memory tracking if it is on
934 // + Wait until we are the last non-daemon thread to execute
935 // <-- every thing is still working at this moment -->
936 // + Call java.lang.Shutdown.shutdown(), which will invoke Java level
937 // shutdown hooks
938 // + Call before_exit(), prepare for VM exit
939 // > run VM level shutdown hooks (they are registered through JVM_OnExit(),
940 // currently the only user of this mechanism is File.deleteOnExit())
941 // > stop watcher thread,
942 // post thread end and vm death events to JVMTI,
943 // stop signal thread
944 // + Call JavaThread::exit(), it will:
945 // > release JNI handle blocks, remove stack guard pages
946 // > remove this thread from Threads list
947 // <-- no more Java code from this thread after this point -->
948 // + Stop VM thread, it will bring the remaining VM to a safepoint and stop
949 // the compiler threads at safepoint
950 // <-- do not use anything that could get blocked by Safepoint -->
951 // + Disable tracing at JNI/JVM barriers
952 // + Set _vm_exited flag for threads that are still running native code
953 // + Call exit_globals()
954 // > deletes tty
955 // > deletes PerfMemory resources
956 // + Delete this thread
957 // + Return to caller
958
959 void Threads::destroy_vm() {
960 JavaThread* thread = JavaThread::current();
961
962 #ifdef ASSERT
963 _vm_complete = false;
964 #endif
965 // Wait until we are the last non-daemon thread to execute, or
966 // if we are a daemon then wait until the last non-daemon thread has
967 // executed.
968 bool daemon = java_lang_Thread::is_daemon(thread->threadObj());
969 int expected = daemon ? 0 : 1;
970 {
971 MonitorLocker nu(Threads_lock);
972 while (Threads::number_of_non_daemon_threads() > expected)
973 // This wait should make safepoint checks, wait without a timeout.
974 nu.wait(0);
975 }
976
977 EventShutdown e;
978 if (e.should_commit()) {
979 e.set_reason("No remaining non-daemon Java threads");
980 e.commit();
981 }
982
983 // Hang forever on exit if we are reporting an error.
984 if (ShowMessageBoxOnError && VMError::is_error_reported()) {
985 os::infinite_sleep();
986 }
987 os::wait_for_keypress_at_exit();
988
989 // run Java level shutdown hooks
990 thread->invoke_shutdown_hooks();
991
992 before_exit(thread);
993
994 thread->exit(true);
995
996 // We are no longer on the main thread list but could still be in a
997 // secondary list where another thread may try to interact with us.
998 // So wait until all such interactions are complete before we bring
999 // the VM to the termination safepoint. Normally this would be done
1000 // using thread->smr_delete() below where we delete the thread, but
1001 // we can't call that after the termination safepoint is active as
1002 // we will deadlock on the Threads_lock. Once all interactions are
1003 // complete it is safe to directly delete the thread at any time.
1004 ThreadsSMRSupport::wait_until_not_protected(thread);
1005
1006 // Stop VM thread.
1007 {
1008 // 4945125 The vm thread comes to a safepoint during exit.
1009 // GC vm_operations can get caught at the safepoint, and the
1010 // heap is unparseable if they are caught. Grab the Heap_lock
1011 // to prevent this. The GC vm_operations will not be able to
1012 // queue until after the vm thread is dead. After this point,
1013 // we'll never emerge out of the safepoint before the VM exits.
1014 // Assert that the thread is terminated so that acquiring the
1015 // Heap_lock doesn't cause the terminated thread to participate in
1016 // the safepoint protocol.
1017
1018 assert(thread->is_terminated(), "must be terminated here");
1019 MutexLocker ml(Heap_lock);
1020
1021 VMThread::wait_for_vm_thread_exit();
1022 assert(SafepointSynchronize::is_at_safepoint(), "VM thread should exit at Safepoint");
1023 VMThread::destroy();
1024 }
1025
1026 // Now, all Java threads are gone except daemon threads. Daemon threads
1027 // running Java code or in VM are stopped by the Safepoint. However,
1028 // daemon threads executing native code are still running. But they
1029 // will be stopped at native=>Java/VM barriers. Note that we can't
1030 // simply kill or suspend them, as it is inherently deadlock-prone.
1031
1032 VM_Exit::set_vm_exited();
1033
1034 // Clean up ideal graph printers after the VMThread has started
1035 // the final safepoint which will block all the Compiler threads.
1036 // Note that this Thread has already logically exited so the
1037 // clean_up() function's use of a JavaThreadIteratorWithHandle
1038 // would be a problem except set_vm_exited() has remembered the
1039 // shutdown thread which is granted a policy exception.
1040 #if defined(COMPILER2) && !defined(PRODUCT)
1041 IdealGraphPrinter::clean_up();
1042 #endif
1043
1044 notify_vm_shutdown();
1045
1046 // exit_globals() will delete tty
1047 exit_globals();
1048
1049 // Deleting the shutdown thread here is safe. See comment on
1050 // wait_until_not_protected() above.
1051 delete thread;
1052
1053 #if INCLUDE_JVMCI
1054 if (JVMCICounterSize > 0) {
1055 FREE_C_HEAP_ARRAY(jlong, JavaThread::_jvmci_old_thread_counters);
1056 }
1057 #endif
1058
1059 LogConfiguration::finalize();
1060 }
1061
1062
1063 jboolean Threads::is_supported_jni_version_including_1_1(jint version) {
1064 if (version == JNI_VERSION_1_1) return JNI_TRUE;
1065 return is_supported_jni_version(version);
1066 }
1067
1068
1069 jboolean Threads::is_supported_jni_version(jint version) {
1070 if (version == JNI_VERSION_1_2) return JNI_TRUE;
1071 if (version == JNI_VERSION_1_4) return JNI_TRUE;
1072 if (version == JNI_VERSION_1_6) return JNI_TRUE;
1073 if (version == JNI_VERSION_1_8) return JNI_TRUE;
1074 if (version == JNI_VERSION_9) return JNI_TRUE;
1075 if (version == JNI_VERSION_10) return JNI_TRUE;
1076 if (version == JNI_VERSION_19) return JNI_TRUE;
1077 if (version == JNI_VERSION_20) return JNI_TRUE;
1078 if (version == JNI_VERSION_21) return JNI_TRUE;
1079 if (version == JNI_VERSION_24) return JNI_TRUE;
1080 return JNI_FALSE;
1081 }
1082
1083 void Threads::add(JavaThread* p, bool force_daemon) {
1084 // The threads lock must be owned at this point
1085 assert(Threads_lock->owned_by_self(), "must have threads lock");
1086 assert(p->monitor_owner_id() != 0, "should be set");
1087
1088 BarrierSet::barrier_set()->on_thread_attach(p);
1089
1090 // Once a JavaThread is added to the Threads list, smr_delete() has
1091 // to be used to delete it. Otherwise we can just delete it directly.
1092 p->set_on_thread_list();
1093
1094 _number_of_threads++;
1095 oop threadObj = p->threadObj();
1096 bool daemon = true;
1097 // Bootstrapping problem: threadObj can be null for initial
1098 // JavaThread (or for threads attached via JNI)
1099 if (!force_daemon &&
1100 (threadObj == nullptr || !java_lang_Thread::is_daemon(threadObj))) {
1101 _number_of_non_daemon_threads++;
1102 daemon = false;
1103 }
1104
1105 ThreadService::add_thread(p, daemon);
1106
1107 // Maintain fast thread list
1108 ThreadsSMRSupport::add_thread(p);
1109
1110 // Increase the ObjectMonitor ceiling for the new thread.
1111 ObjectSynchronizer::inc_in_use_list_ceiling();
1112
1113 // Possible GC point.
1114 Events::log(Thread::current(), "Thread added: " INTPTR_FORMAT, p2i(p));
1115
1116 // Make new thread known to active EscapeBarrier
1117 EscapeBarrier::thread_added(p);
1118 }
1119
1120 void Threads::remove(JavaThread* p, bool is_daemon) {
1121 // Extra scope needed for Thread_lock, so we can check
1122 // that we do not remove thread without safepoint code notice
1123 {
1124 ConditionalMutexLocker throttle_ml(ThreadsLockThrottle_lock, UseThreadsLockThrottleLock);
1125 MonitorLocker ml(Threads_lock);
1126
1127 if (ThreadIdTable::is_initialized()) {
1128 // This cleanup must be done before the current thread's GC barrier
1129 // is detached since we need to touch the threadObj oop.
1130 jlong tid = SharedRuntime::get_java_tid(p);
1131 ThreadIdTable::remove_thread(tid);
1132 }
1133
1134 // BarrierSet state must be destroyed after the last thread transition
1135 // before the thread terminates. Thread transitions result in calls to
1136 // StackWatermarkSet::on_safepoint(), which performs GC processing,
1137 // requiring the GC state to be alive.
1138 BarrierSet::barrier_set()->on_thread_detach(p);
1139 if (p->is_exiting()) {
1140 // If we got here via JavaThread::exit(), then we remember that the
1141 // thread's GC barrier has been detached. We don't do this when we get
1142 // here from another path, e.g., cleanup_failed_attach_current_thread().
1143 p->set_terminated(JavaThread::_thread_gc_barrier_detached);
1144 }
1145
1146 assert(ThreadsSMRSupport::get_java_thread_list()->includes(p), "p must be present");
1147
1148 // Maintain fast thread list
1149 ThreadsSMRSupport::remove_thread(p);
1150
1151 _number_of_threads--;
1152 if (!is_daemon) {
1153 _number_of_non_daemon_threads--;
1154
1155 // If this is the last non-daemon thread then we need to do
1156 // a notify on the Threads_lock so a thread waiting
1157 // on destroy_vm will wake up. But that thread could be a daemon
1158 // or non-daemon, so we notify for both the 0 and 1 case.
1159 if (number_of_non_daemon_threads() <= 1) {
1160 ml.notify_all();
1161 }
1162 }
1163 ThreadService::remove_thread(p, is_daemon);
1164
1165 // Make sure that safepoint code disregard this thread. This is needed since
1166 // the thread might mess around with locks after this point. This can cause it
1167 // to do callbacks into the safepoint code. However, the safepoint code is not aware
1168 // of this thread since it is removed from the queue.
1169 p->set_terminated(JavaThread::_thread_terminated);
1170
1171 // Notify threads waiting in EscapeBarriers
1172 EscapeBarrier::thread_removed(p);
1173 } // unlock Threads_lock and ThreadsLockThrottle_lock
1174
1175 // Reduce the ObjectMonitor ceiling for the exiting thread.
1176 ObjectSynchronizer::dec_in_use_list_ceiling();
1177
1178 // Since Events::log uses a lock, we grab it outside the Threads_lock
1179 Events::log(Thread::current(), "Thread exited: " INTPTR_FORMAT, p2i(p));
1180 }
1181
1182 // Operations on the Threads list for GC. These are not explicitly locked,
1183 // but the garbage collector must provide a safe context for them to run.
1184 // In particular, these things should never be called when the Threads_lock
1185 // is held by some other thread. (Note: the Safepoint abstraction also
1186 // uses the Threads_lock to guarantee this property. It also makes sure that
1187 // all threads gets blocked when exiting or starting).
1188
1189 void Threads::oops_do(OopClosure* f, NMethodClosure* cf) {
1190 ALL_JAVA_THREADS(p) {
1191 p->oops_do(f, cf);
1192 }
1193 VMThread::vm_thread()->oops_do(f, cf);
1194 }
1195
1196 void Threads::change_thread_claim_token() {
1197 if (++_thread_claim_token == 0) {
1198 // On overflow of the token counter, there is a risk of future
1199 // collisions between a new global token value and a stale token
1200 // for a thread, because not all iterations visit all threads.
1201 // (Though it's pretty much a theoretical concern for non-trivial
1202 // token counter sizes.) To deal with the possibility, reset all
1203 // the thread tokens to zero on global token overflow.
1204 struct ResetClaims : public ThreadClosure {
1205 virtual void do_thread(Thread* t) {
1206 t->claim_threads_do(false, 0);
1207 }
1208 } reset_claims;
1209 Threads::threads_do(&reset_claims);
1210 // On overflow, update the global token to non-zero, to
1211 // avoid the special "never claimed" initial thread value.
1212 _thread_claim_token = 1;
1213 }
1214 }
1215
1216 #ifdef ASSERT
1217 static void assert_thread_claimed(const char* kind, Thread* t, uintx expected) {
1218 const uintx token = t->threads_do_token();
1219 assert(token == expected,
1220 "%s " PTR_FORMAT " has incorrect value %zu != %zu",
1221 kind, p2i(t), token, expected);
1222 }
1223
1224 void Threads::assert_all_threads_claimed() {
1225 ALL_JAVA_THREADS(p) {
1226 assert_thread_claimed("JavaThread", p, _thread_claim_token);
1227 }
1228
1229 struct NJTClaimedVerifierClosure : public ThreadClosure {
1230 uintx _thread_claim_token;
1231
1232 NJTClaimedVerifierClosure(uintx thread_claim_token) : ThreadClosure(), _thread_claim_token(thread_claim_token) { }
1233
1234 virtual void do_thread(Thread* thread) override {
1235 assert_thread_claimed("Non-JavaThread", VMThread::vm_thread(), _thread_claim_token);
1236 }
1237 } tc(_thread_claim_token);
1238
1239 non_java_threads_do(&tc);
1240 }
1241 #endif // ASSERT
1242
1243 class ParallelOopsDoThreadClosure : public ThreadClosure {
1244 private:
1245 OopClosure* _f;
1246 NMethodClosure* _cf;
1247 public:
1248 ParallelOopsDoThreadClosure(OopClosure* f, NMethodClosure* cf) : _f(f), _cf(cf) {}
1249 void do_thread(Thread* t) {
1250 t->oops_do(_f, _cf);
1251 }
1252 };
1253
1254 void Threads::possibly_parallel_oops_do(bool is_par, OopClosure* f, NMethodClosure* cf) {
1255 ParallelOopsDoThreadClosure tc(f, cf);
1256 possibly_parallel_threads_do(is_par, &tc);
1257 }
1258
1259 void Threads::metadata_do(MetadataClosure* f) {
1260 ALL_JAVA_THREADS(p) {
1261 p->metadata_do(f);
1262 }
1263 }
1264
1265 class ThreadHandlesClosure : public ThreadClosure {
1266 void (*_f)(Metadata*);
1267 public:
1268 ThreadHandlesClosure(void f(Metadata*)) : _f(f) {}
1269 virtual void do_thread(Thread* thread) {
1270 thread->metadata_handles_do(_f);
1271 }
1272 };
1273
1274 void Threads::metadata_handles_do(void f(Metadata*)) {
1275 // Only walk the Handles in Thread.
1276 ThreadHandlesClosure handles_closure(f);
1277 threads_do(&handles_closure);
1278 }
1279
1280 #if INCLUDE_JVMTI
1281 // Get Java threads that are waiting to enter or re-enter the specified monitor.
1282 // Java threads that are executing mounted virtual threads are not included.
1283 GrowableArray<JavaThread*>* Threads::get_pending_threads(ThreadsList * t_list,
1284 int count,
1285 address monitor) {
1286 assert(Thread::current()->is_VM_thread(), "Must be the VM thread");
1287 GrowableArray<JavaThread*>* result = new GrowableArray<JavaThread*>(count);
1288
1289 int i = 0;
1290 for (JavaThread* p : *t_list) {
1291 if (!p->can_call_java()) continue;
1292
1293 oop thread_oop = JvmtiEnvBase::get_vthread_or_thread_oop(p);
1294 if (thread_oop->is_a(vmClasses::BaseVirtualThread_klass())) {
1295 continue;
1296 }
1297 // The first stage of async deflation does not affect any field
1298 // used by this comparison so the ObjectMonitor* is usable here.
1299 address pending = (address)p->current_pending_monitor();
1300 address waiting = (address)p->current_waiting_monitor();
1301 // do not include virtual threads to the list
1302 jint state = JvmtiEnvBase::get_thread_state(thread_oop, p);
1303 if (pending == monitor || (waiting == monitor &&
1304 (state & JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER))
1305 ) { // found a match
1306 if (i < count) result->append(p); // save the first count matches
1307 i++;
1308 }
1309 }
1310
1311 return result;
1312 }
1313 #endif // INCLUDE_JVMTI
1314
1315 JavaThread* Threads::owning_thread_from_object(ThreadsList * t_list, oop obj) {
1316 for (JavaThread* q : *t_list) {
1317 // Need to start processing before accessing oops in the thread.
1318 StackWatermark* watermark = StackWatermarkSet::get(q, StackWatermarkKind::gc);
1319 if (watermark != nullptr) {
1320 watermark->start_processing();
1321 }
1322
1323 if (q->lock_stack().contains(obj)) {
1324 return q;
1325 }
1326 }
1327 return nullptr;
1328 }
1329
1330 JavaThread* Threads::owning_thread_from_monitor(ThreadsList* t_list, ObjectMonitor* monitor) {
1331 if (monitor->has_anonymous_owner()) {
1332 return owning_thread_from_object(t_list, monitor->object());
1333 } else {
1334 JavaThread* the_owner = nullptr;
1335 for (JavaThread* q : *t_list) {
1336 if (monitor->has_owner(q)) {
1337 the_owner = q;
1338 break;
1339 }
1340 }
1341 return the_owner;
1342 }
1343 }
1344
1345 class PrintOnClosure : public ThreadClosure {
1346 private:
1347 outputStream* _st;
1348
1349 public:
1350 PrintOnClosure(outputStream* st) :
1351 _st(st) {}
1352
1353 virtual void do_thread(Thread* thread) {
1354 if (thread != nullptr) {
1355 thread->print_on(_st);
1356 _st->cr();
1357 }
1358 }
1359 };
1360
1361 // Threads::print_on() is called at safepoint by VM_PrintThreads operation.
1362 void Threads::print_on(outputStream* st, bool print_stacks,
1363 bool internal_format, bool print_concurrent_locks,
1364 bool print_extended_info) {
1365 char buf[32];
1366 st->print_raw_cr(os::local_time_string(buf, sizeof(buf)));
1367
1368 st->print_cr("Full thread dump %s (%s %s)",
1369 VM_Version::vm_name(),
1370 VM_Version::vm_release(),
1371 VM_Version::vm_info_string());
1372 JDK_Version::current().to_string(buf, sizeof(buf));
1373 const char* runtime_name = JDK_Version::runtime_name() != nullptr ?
1374 JDK_Version::runtime_name() : "";
1375 const char* runtime_version = JDK_Version::runtime_version() != nullptr ?
1376 JDK_Version::runtime_version() : "";
1377 const char* vendor_version = JDK_Version::runtime_vendor_version() != nullptr ?
1378 JDK_Version::runtime_vendor_version() : "";
1379 const char* jdk_debug_level = VM_Version::printable_jdk_debug_level() != nullptr ?
1380 VM_Version::printable_jdk_debug_level() : "";
1381
1382 st->print_cr(" JDK version: %s%s%s (%s) (%sbuild %s)", runtime_name,
1383 (*vendor_version != '\0') ? " " : "", vendor_version,
1384 buf, jdk_debug_level, runtime_version);
1385
1386 st->cr();
1387
1388 #if INCLUDE_SERVICES
1389 // Dump concurrent locks
1390 ConcurrentLocksDump concurrent_locks;
1391 if (print_concurrent_locks) {
1392 concurrent_locks.dump_at_safepoint();
1393 }
1394 #endif // INCLUDE_SERVICES
1395
1396 ThreadsSMRSupport::print_info_on(st);
1397 st->cr();
1398
1399 ALL_JAVA_THREADS(p) {
1400 ResourceMark rm;
1401 p->print_on(st, print_extended_info);
1402 if (print_stacks) {
1403 if (internal_format) {
1404 p->trace_stack();
1405 } else {
1406 p->print_stack_on(st);
1407 if (p->is_vthread_mounted()) {
1408 st->print_cr(" Mounted virtual thread #" INT64_FORMAT, java_lang_Thread::thread_id(p->vthread()));
1409 p->print_vthread_stack_on(st);
1410 }
1411 }
1412 }
1413 st->cr();
1414 #if INCLUDE_SERVICES
1415 if (print_concurrent_locks) {
1416 concurrent_locks.print_locks_on(p, st);
1417 }
1418 #endif // INCLUDE_SERVICES
1419 }
1420
1421 PrintOnClosure cl(st);
1422 non_java_threads_do(&cl);
1423
1424 st->flush();
1425 }
1426
1427 void Threads::print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
1428 int buflen, bool* found_current) {
1429 if (this_thread != nullptr) {
1430 bool is_current = (current == this_thread);
1431 *found_current = *found_current || is_current;
1432 st->print("%s", is_current ? "=>" : " ");
1433
1434 st->print(PTR_FORMAT, p2i(this_thread));
1435 st->print(" ");
1436 this_thread->print_on_error(st, buf, buflen);
1437 st->cr();
1438 }
1439 }
1440
1441 class PrintOnErrorClosure : public ThreadClosure {
1442 outputStream* _st;
1443 Thread* _current;
1444 char* _buf;
1445 int _buflen;
1446 bool* _found_current;
1447 unsigned _num_printed;
1448 public:
1449 PrintOnErrorClosure(outputStream* st, Thread* current, char* buf,
1450 int buflen, bool* found_current) :
1451 _st(st), _current(current), _buf(buf), _buflen(buflen), _found_current(found_current),
1452 _num_printed(0) {}
1453
1454 virtual void do_thread(Thread* thread) {
1455 _num_printed++;
1456 Threads::print_on_error(thread, _st, _current, _buf, _buflen, _found_current);
1457 }
1458
1459 unsigned num_printed() const { return _num_printed; }
1460 };
1461
1462 // Threads::print_on_error() is called by fatal error handler. It's possible
1463 // that VM is not at safepoint and/or current thread is inside signal handler.
1464 // Don't print stack trace, as the stack may not be walkable. Don't allocate
1465 // memory (even in resource area), it might deadlock the error handler.
1466 void Threads::print_on_error(outputStream* st, Thread* current, char* buf,
1467 int buflen) {
1468 ThreadsSMRSupport::print_info_on(st);
1469 st->cr();
1470
1471 bool found_current = false;
1472 st->print_cr("Java Threads: ( => current thread )");
1473 unsigned num_java = 0;
1474 ALL_JAVA_THREADS(thread) {
1475 print_on_error(thread, st, current, buf, buflen, &found_current);
1476 num_java++;
1477 }
1478 st->print_cr("Total: %u", num_java);
1479 st->cr();
1480
1481 st->print_cr("Other Threads:");
1482 unsigned num_other = ((VMThread::vm_thread() != nullptr) ? 1 : 0) +
1483 ((WatcherThread::watcher_thread() != nullptr) ? 1 : 0) +
1484 ((AsyncLogWriter::instance() != nullptr) ? 1 : 0);
1485 print_on_error(VMThread::vm_thread(), st, current, buf, buflen, &found_current);
1486 print_on_error(WatcherThread::watcher_thread(), st, current, buf, buflen, &found_current);
1487 print_on_error(AsyncLogWriter::instance(), st, current, buf, buflen, &found_current);
1488
1489 if (Universe::heap() != nullptr) {
1490 PrintOnErrorClosure print_closure(st, current, buf, buflen, &found_current);
1491 Universe::heap()->gc_threads_do(&print_closure);
1492 num_other += print_closure.num_printed();
1493 }
1494
1495 if (!found_current) {
1496 st->cr();
1497 st->print("=>" PTR_FORMAT " (exited) ", p2i(current));
1498 current->print_on_error(st, buf, buflen);
1499 num_other++;
1500 st->cr();
1501 }
1502 st->print_cr("Total: %u", num_other);
1503 st->cr();
1504
1505 st->print_cr("Threads with active compile tasks:");
1506 unsigned num = print_threads_compiling(st, buf, buflen);
1507 st->print_cr("Total: %u", num);
1508 }
1509
1510 unsigned Threads::print_threads_compiling(outputStream* st, char* buf, int buflen, bool short_form) {
1511 unsigned num = 0;
1512 ALL_JAVA_THREADS(thread) {
1513 if (thread->is_Compiler_thread()) {
1514 CompilerThread* ct = (CompilerThread*) thread;
1515
1516 // Keep task in local variable for null check.
1517 // ct->_task might be set to null by concurring compiler thread
1518 // because it completed the compilation. The task is never freed,
1519 // though, just returned to a free list.
1520 CompileTask* task = ct->task();
1521 if (task != nullptr) {
1522 thread->print_name_on_error(st, buf, buflen);
1523 st->print(" ");
1524 task->print(st, nullptr, short_form, true);
1525 num++;
1526 }
1527 }
1528 }
1529 return num;
1530 }
1531
1532 void Threads::verify() {
1533 ALL_JAVA_THREADS(p) {
1534 p->verify();
1535 }
1536 VMThread* thread = VMThread::vm_thread();
1537 if (thread != nullptr) thread->verify();
1538 }