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 "cds/methodProfiler.hpp"
32 #include "classfile/classLoader.hpp"
33 #include "classfile/javaClasses.hpp"
34 #include "classfile/javaThreadStatus.hpp"
35 #include "classfile/symbolTable.hpp"
36 #include "classfile/systemDictionary.hpp"
37 #include "classfile/systemDictionaryShared.hpp"
38 #include "classfile/vmClasses.hpp"
39 #include "classfile/vmSymbols.hpp"
40 #include "code/aotCodeCache.hpp"
41 #include "compiler/compilationPolicy.hpp"
42 #include "compiler/compileBroker.hpp"
43 #include "compiler/compilerThread.hpp"
44 #include "compiler/compileTask.hpp"
45 #include "compiler/precompiler.hpp"
46 #include "gc/shared/barrierSet.hpp"
47 #include "gc/shared/barrierSetNMethod.hpp"
48 #include "gc/shared/gcVMOperations.hpp"
49 #include "gc/shared/oopStorage.hpp"
50 #include "gc/shared/oopStorageSet.hpp"
51 #include "gc/shared/stringdedup/stringDedup.hpp"
52 #include "interpreter/interpreterRuntime.hpp"
53 #include "jfr/jfrEvents.hpp"
54 #include "jvm.h"
55 #include "jvmtifiles/jvmtiEnv.hpp"
56 #include "logging/log.hpp"
57 #include "logging/logAsyncWriter.hpp"
58 #include "logging/logConfiguration.hpp"
59 #include "memory/allocation.inline.hpp"
60 #include "memory/iterator.hpp"
61 #include "memory/oopFactory.hpp"
62 #include "memory/resourceArea.hpp"
63 #include "memory/universe.hpp"
64 #include "nmt/memTracker.hpp"
65 #include "oops/instanceKlass.hpp"
66 #include "oops/klass.inline.hpp"
67 #include "oops/oop.inline.hpp"
68 #include "oops/symbol.hpp"
69 #include "prims/jvm_misc.hpp"
70 #include "prims/jvmtiAgentList.hpp"
71 #include "prims/jvmtiEnvBase.hpp"
72 #include "runtime/arguments.hpp"
73 #include "runtime/fieldDescriptor.inline.hpp"
74 #include "runtime/flags/jvmFlagLimit.hpp"
75 #include "runtime/globals.hpp"
76 #include "runtime/globals_extension.hpp"
77 #include "runtime/handles.inline.hpp"
78 #include "runtime/interfaceSupport.inline.hpp"
79 #include "runtime/java.hpp"
80 #include "runtime/javaCalls.hpp"
81 #include "runtime/javaThread.inline.hpp"
82 #include "runtime/jniHandles.inline.hpp"
83 #include "runtime/jniPeriodicChecker.hpp"
84 #include "runtime/lockStack.inline.hpp"
85 #include "runtime/monitorDeflationThread.hpp"
86 #include "runtime/mutexLocker.hpp"
87 #include "runtime/nonJavaThread.hpp"
88 #include "runtime/objectMonitor.inline.hpp"
89 #include "runtime/osThread.hpp"
90 #include "runtime/perfData.hpp"
91 #include "runtime/safepoint.hpp"
92 #include "runtime/safepointMechanism.inline.hpp"
93 #include "runtime/safepointVerifiers.hpp"
94 #include "runtime/serviceThread.hpp"
95 #include "runtime/sharedRuntime.hpp"
96 #include "runtime/stackWatermarkSet.inline.hpp"
97 #include "runtime/stubCodeGenerator.hpp"
98 #include "runtime/thread.inline.hpp"
99 #include "runtime/threads.hpp"
100 #include "runtime/threadSMR.inline.hpp"
101 #include "runtime/timer.hpp"
102 #include "runtime/timerTrace.hpp"
103 #include "runtime/trimNativeHeap.hpp"
104 #include "runtime/vm_version.hpp"
105 #include "runtime/vmOperations.hpp"
106 #include "services/attachListener.hpp"
107 #include "services/management.hpp"
108 #include "services/threadIdTable.hpp"
109 #include "services/threadService.hpp"
110 #include "utilities/dtrace.hpp"
111 #include "utilities/events.hpp"
112 #include "utilities/macros.hpp"
113 #include "utilities/vmError.hpp"
114 #if INCLUDE_JVMCI
115 #include "jvmci/jvmci.hpp"
116 #include "jvmci/jvmciEnv.hpp"
117 #endif
118 #ifdef COMPILER1
119 #include "c1/c1_Runtime1.hpp"
120 #endif
121 #ifdef COMPILER2
122 #include "opto/idealGraphPrinter.hpp"
123 #include "opto/runtime.hpp"
124 #endif
125 #if INCLUDE_JFR
126 #include "jfr/jfr.hpp"
127 #endif
128
129 // Initialization after module runtime initialization
130 void universe_post_module_init(); // must happen after call_initPhase2
131
132
133 static void initialize_class(Symbol* class_name, TRAPS) {
134 Klass* klass = SystemDictionary::resolve_or_fail(class_name, true, CHECK);
135 InstanceKlass::cast(klass)->initialize(CHECK);
136 }
137
138
139 // Creates the initial ThreadGroup
140 static Handle create_initial_thread_group(TRAPS) {
141 Handle system_instance = JavaCalls::construct_new_instance(
142 vmClasses::ThreadGroup_klass(),
143 vmSymbols::void_method_signature(),
144 CHECK_NH);
145 Universe::set_system_thread_group(system_instance());
146
147 Handle string = java_lang_String::create_from_str("main", CHECK_NH);
148 Handle main_instance = JavaCalls::construct_new_instance(
149 vmClasses::ThreadGroup_klass(),
150 vmSymbols::threadgroup_string_void_signature(),
151 system_instance,
152 string,
153 CHECK_NH);
154 return main_instance;
155 }
156
157 // Creates the initial Thread, and sets it to running.
158 static void create_initial_thread(Handle thread_group, JavaThread* thread,
159 TRAPS) {
160 InstanceKlass* ik = vmClasses::Thread_klass();
161 assert(ik->is_initialized(), "must be");
162 instanceHandle thread_oop = ik->allocate_instance_handle(CHECK);
163
164 // Cannot use JavaCalls::construct_new_instance because the java.lang.Thread
165 // constructor calls Thread.current(), which must be set here for the
166 // initial thread.
167 java_lang_Thread::set_thread(thread_oop(), thread);
168 thread->set_threadOopHandles(thread_oop());
169
170 Handle string = java_lang_String::create_from_str("main", CHECK);
171
172 JavaValue result(T_VOID);
173 JavaCalls::call_special(&result, thread_oop,
174 ik,
175 vmSymbols::object_initializer_name(),
176 vmSymbols::threadgroup_string_void_signature(),
177 thread_group,
178 string,
179 CHECK);
180
181 DEBUG_ONLY(int64_t main_thread_tid = java_lang_Thread::thread_id(thread_oop());)
182 assert(main_thread_tid == ThreadIdentifier::initial(), "");
183 assert(main_thread_tid == thread->monitor_owner_id(), "");
184 JFR_ONLY(assert(JFR_JVM_THREAD_ID(thread) == static_cast<traceid>(main_thread_tid), "initial tid mismatch");)
185
186 // Set thread status to running since main thread has
187 // been started and running.
188 java_lang_Thread::set_thread_status(thread_oop(),
189 JavaThreadStatus::RUNNABLE);
190 }
191
192 // Extract version and vendor specific information from
193 // java.lang.VersionProps fields.
194 // Returned char* is allocated in the thread's resource area
195 // so must be copied for permanency.
196 static const char* get_java_version_info(InstanceKlass* ik,
197 Symbol* field_name) {
198 fieldDescriptor fd;
199 bool found = ik != nullptr &&
200 ik->find_local_field(field_name,
201 vmSymbols::string_signature(), &fd);
202 if (found) {
203 oop name_oop = ik->java_mirror()->obj_field(fd.offset());
204 if (name_oop == nullptr) {
205 return nullptr;
206 }
207 const char* name = java_lang_String::as_utf8_string(name_oop);
208 return name;
209 } else {
210 return nullptr;
211 }
212 }
213
214 // ======= Threads ========
215
216 // The Threads class links together all active threads, and provides
217 // operations over all threads. It is protected by the Threads_lock,
218 // which is also used in other global contexts like safepointing.
219 // ThreadsListHandles are used to safely perform operations on one
220 // or more threads without the risk of the thread exiting during the
221 // operation.
222 //
223 // Note: The Threads_lock is currently more widely used than we
224 // would like. We are actively migrating Threads_lock uses to other
225 // mechanisms in order to reduce Threads_lock contention.
226
227 int Threads::_number_of_threads = 0;
228 int Threads::_number_of_non_daemon_threads = 0;
229 int Threads::_return_code = 0;
230 uintx Threads::_thread_claim_token = 1; // Never zero.
231
232 #ifdef ASSERT
233 bool Threads::_vm_complete = false;
234 #endif
235
236 // General purpose hook into Java code, run once when the VM is initialized.
237 // The Java library method itself may be changed independently from the VM.
238 static void call_postVMInitHook(TRAPS) {
239 Klass* klass = SystemDictionary::resolve_or_null(vmSymbols::jdk_internal_vm_PostVMInitHook(), THREAD);
240 if (klass != nullptr) {
241 JavaValue result(T_VOID);
242 JavaCalls::call_static(&result, klass, vmSymbols::run_method_name(),
243 vmSymbols::void_method_signature(),
244 CHECK);
245 }
246 }
247
248 // All NonJavaThreads (i.e., every non-JavaThread in the system).
249 void Threads::non_java_threads_do(ThreadClosure* tc) {
250 NoSafepointVerifier nsv;
251 for (NonJavaThread::Iterator njti; !njti.end(); njti.step()) {
252 tc->do_thread(njti.current());
253 }
254 }
255
256 // All JavaThreads
257 #define ALL_JAVA_THREADS(X) \
258 for (JavaThread* X : *ThreadsSMRSupport::get_java_thread_list())
259
260 // All JavaThreads
261 void Threads::java_threads_do(ThreadClosure* tc) {
262 assert_locked_or_safepoint(Threads_lock);
263 // ALL_JAVA_THREADS iterates through all JavaThreads.
264 ALL_JAVA_THREADS(p) {
265 tc->do_thread(p);
266 }
267 }
268
269 // All JavaThreads + all non-JavaThreads (i.e., every thread in the system).
270 void Threads::threads_do(ThreadClosure* tc) {
271 assert_locked_or_safepoint(Threads_lock);
272 java_threads_do(tc);
273 non_java_threads_do(tc);
274 }
275
276 void Threads::possibly_parallel_threads_do(bool is_par, ThreadClosure* tc) {
277 assert_at_safepoint();
278
279 uintx claim_token = Threads::thread_claim_token();
280 ALL_JAVA_THREADS(p) {
281 if (p->claim_threads_do(is_par, claim_token)) {
282 tc->do_thread(p);
283 }
284 }
285 for (NonJavaThread::Iterator njti; !njti.end(); njti.step()) {
286 Thread* current = njti.current();
287 if (current->claim_threads_do(is_par, claim_token)) {
288 tc->do_thread(current);
289 }
290 }
291 }
292
293 // The system initialization in the library has three phases.
294 //
295 // Phase 1: java.lang.System class initialization
296 // java.lang.System is a primordial class loaded and initialized
297 // by the VM early during startup. java.lang.System.<clinit>
298 // only does registerNatives and keeps the rest of the class
299 // initialization work later until thread initialization completes.
300 //
301 // System.initPhase1 initializes the system properties, the static
302 // fields in, out, and err. Set up java signal handlers, OS-specific
303 // system settings, and thread group of the main thread.
304 static void call_initPhase1(TRAPS) {
305 Klass* klass = vmClasses::System_klass();
306 JavaValue result(T_VOID);
307 JavaCalls::call_static(&result, klass, vmSymbols::initPhase1_name(),
308 vmSymbols::void_method_signature(), CHECK);
309 }
310
311 // Phase 2. Module system initialization
312 // This will initialize the module system. Only java.base classes
313 // can be loaded until phase 2 completes.
314 //
315 // Call System.initPhase2 after the compiler initialization and jsr292
316 // classes get initialized because module initialization runs a lot of java
317 // code, that for performance reasons, should be compiled. Also, this will
318 // enable the startup code to use lambda and other language features in this
319 // phase and onward.
320 //
321 // After phase 2, The VM will begin search classes from -Xbootclasspath/a.
322 static void call_initPhase2(TRAPS) {
323 TraceTime timer("Initialize module system", TRACETIME_LOG(Info, startuptime));
324
325 Klass* klass = vmClasses::System_klass();
326
327 JavaValue result(T_INT);
328 JavaCallArguments args;
329 args.push_int(DisplayVMOutputToStderr);
330 args.push_int(log_is_enabled(Debug, init)); // print stack trace if exception thrown
331 JavaCalls::call_static(&result, klass, vmSymbols::initPhase2_name(),
332 vmSymbols::boolean_boolean_int_signature(), &args, CHECK);
333 if (result.get_jint() != JNI_OK) {
334 vm_exit_during_initialization(); // no message or exception
335 }
336
337 universe_post_module_init();
338 }
339
340 // Phase 3. final setup - set security manager, system class loader and TCCL
341 //
342 // This will instantiate and set the security manager, set the system class
343 // loader as well as the thread context class loader. The security manager
344 // and system class loader may be a custom class loaded from -Xbootclasspath/a,
345 // other modules or the application's classpath.
346 static void call_initPhase3(TRAPS) {
347 Klass* klass = vmClasses::System_klass();
348 JavaValue result(T_VOID);
349 JavaCalls::call_static(&result, klass, vmSymbols::initPhase3_name(),
350 vmSymbols::void_method_signature(), CHECK);
351 }
352
353 void Threads::initialize_java_lang_classes(JavaThread* main_thread, TRAPS) {
354 TraceTime timer("Initialize java.lang classes", TRACETIME_LOG(Info, startuptime));
355
356 initialize_class(vmSymbols::java_lang_String(), CHECK);
357
358 // Inject CompactStrings value after the static initializers for String ran.
359 java_lang_String::set_compact_strings(CompactStrings);
360
361 // Initialize java_lang.System (needed before creating the thread)
362 initialize_class(vmSymbols::java_lang_System(), CHECK);
363 // The VM creates & returns objects of this class. Make sure it's initialized.
364 initialize_class(vmSymbols::java_lang_Class(), CHECK);
365
366 initialize_class(vmSymbols::java_lang_ThreadGroup(), CHECK);
367 Handle thread_group = create_initial_thread_group(CHECK);
368 Universe::set_main_thread_group(thread_group());
369 initialize_class(vmSymbols::java_lang_Thread(), CHECK);
370 create_initial_thread(thread_group, main_thread, CHECK);
371
372 HeapShared::init_box_classes(CHECK);
373
374 // The VM creates objects of this class.
375 initialize_class(vmSymbols::java_lang_Module(), CHECK);
376
377 #ifdef ASSERT
378 InstanceKlass *k = vmClasses::UnsafeConstants_klass();
379 assert(k->is_not_initialized(), "UnsafeConstants should not already be initialized");
380 #endif
381
382 // initialize the hardware-specific constants needed by Unsafe
383 initialize_class(vmSymbols::jdk_internal_misc_UnsafeConstants(), CHECK);
384 jdk_internal_misc_UnsafeConstants::set_unsafe_constants();
385
386 // The VM preresolves methods to these classes. Make sure that they get initialized
387 initialize_class(vmSymbols::java_lang_reflect_Method(), CHECK);
388 initialize_class(vmSymbols::java_lang_ref_Finalizer(), CHECK);
389
390 if (CDSConfig::is_using_aot_linked_classes()) {
391 // This is necessary for reflection to work in early core lib bootstrap code.
392 vmClasses::reflect_AccessibleObject_klass()->link_class(CHECK);
393 vmClasses::reflect_Field_klass()->link_class(CHECK);
394 vmClasses::reflect_Parameter_klass()->link_class(CHECK);
395 vmClasses::reflect_Method_klass()->link_class(CHECK);
396 vmClasses::reflect_Constructor_klass()->link_class(CHECK);
397 }
398
399 // Phase 1 of the system initialization in the library, java.lang.System class initialization
400 call_initPhase1(CHECK);
401
402 // Get the Java runtime name, version, and vendor info after java.lang.System is initialized.
403 // Some values are actually configure-time constants but some can be set via the jlink tool and
404 // so must be read dynamically. We treat them all the same.
405 InstanceKlass* ik = SystemDictionary::find_instance_klass(THREAD, vmSymbols::java_lang_VersionProps(),
406 Handle());
407 {
408 ResourceMark rm(main_thread);
409 JDK_Version::set_java_version(get_java_version_info(ik, vmSymbols::java_version_name()));
410
411 JDK_Version::set_runtime_name(get_java_version_info(ik, vmSymbols::java_runtime_name_name()));
412
413 JDK_Version::set_runtime_version(get_java_version_info(ik, vmSymbols::java_runtime_version_name()));
414
415 JDK_Version::set_runtime_vendor_version(get_java_version_info(ik, vmSymbols::java_runtime_vendor_version_name()));
416
417 JDK_Version::set_runtime_vendor_vm_bug_url(get_java_version_info(ik, vmSymbols::java_runtime_vendor_vm_bug_url_name()));
418 }
419
420 // an instance of OutOfMemory exception has been allocated earlier
421 initialize_class(vmSymbols::java_lang_OutOfMemoryError(), CHECK);
422 initialize_class(vmSymbols::java_lang_NullPointerException(), CHECK);
423 initialize_class(vmSymbols::java_lang_ClassCastException(), CHECK);
424 initialize_class(vmSymbols::java_lang_ArrayStoreException(), CHECK);
425 initialize_class(vmSymbols::java_lang_ArithmeticException(), CHECK);
426 initialize_class(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), CHECK);
427 initialize_class(vmSymbols::java_lang_StackOverflowError(), CHECK);
428 initialize_class(vmSymbols::java_lang_IllegalMonitorStateException(), CHECK);
429 initialize_class(vmSymbols::java_lang_IllegalArgumentException(), CHECK);
430 initialize_class(vmSymbols::java_lang_InternalError(), CHECK);
431 }
432
433 bool Threads::initialize_compilation(TRAPS) {
434 // initialize compiler(s)
435 bool force_JVMCI_initialization = false;
436
437 #if defined(COMPILER1) || COMPILER2_OR_JVMCI
438 bool init_compilation = true;
439 #if INCLUDE_JVMCI
440 if (EnableJVMCI) {
441 // Initialize JVMCI eagerly when it is explicitly requested.
442 // Or when JVMCILibDumpJNIConfig or JVMCIPrintProperties is enabled.
443 force_JVMCI_initialization = EagerJVMCI || JVMCIPrintProperties || JVMCILibDumpJNIConfig;
444 if (!force_JVMCI_initialization && UseJVMCICompiler && !UseJVMCINativeLibrary && (!UseInterpreter || !BackgroundCompilation)) {
445 // Force initialization of jarjvmci otherwise requests for blocking
446 // compilations will not actually block until jarjvmci is initialized.
447 force_JVMCI_initialization = true;
448 }
449 if (JVMCIPrintProperties || JVMCILibDumpJNIConfig) {
450 // Both JVMCILibDumpJNIConfig and JVMCIPrintProperties exit the VM
451 // so compilation should be disabled. This prevents dumping or
452 // printing from happening more than once.
453 init_compilation = false;
454 }
455 }
456 #endif
457 if (init_compilation) {
458 CompileBroker::compilation_init(CHECK_false);
459 }
460 #endif
461
462 return force_JVMCI_initialization;
463 }
464
465 void Threads::initialize_jsr292_core_classes(TRAPS) {
466 TraceTime timer("Initialize java.lang.invoke classes", TRACETIME_LOG(Info, startuptime));
467
468 initialize_class(vmSymbols::java_lang_invoke_MethodHandle(), CHECK);
469 initialize_class(vmSymbols::java_lang_invoke_ResolvedMethodName(), CHECK);
470 initialize_class(vmSymbols::java_lang_invoke_MemberName(), CHECK);
471 initialize_class(vmSymbols::java_lang_invoke_MethodHandleNatives(), CHECK);
472
473 if (UseSharedSpaces) {
474 HeapShared::initialize_java_lang_invoke(CHECK);
475 }
476 }
477
478 // One-shot PeriodicTask subclass for reading the release file
479 class ReadReleaseFileTask : public PeriodicTask {
480 public:
481 ReadReleaseFileTask() : PeriodicTask(100) {}
482
483 virtual void task() {
484 os::read_image_release_file();
485
486 // Reclaim our storage and disenroll ourself.
487 delete this;
488 }
489 };
490
491 jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) {
492 extern void JDK_Version_init();
493
494 // Preinitialize version info.
495 VM_Version::early_initialize();
496
497 // Check version
498 if (!is_supported_jni_version(args->version)) return JNI_EVERSION;
499
500 // Deferred "static" initialization
501 NonJavaThread::init();
502
503 // Initialize library-based TLS
504 ThreadLocalStorage::init();
505
506 // Initialize the output stream module
507 ostream_init();
508
509 // Process java launcher properties.
510 Arguments::process_sun_java_launcher_properties(args);
511
512 // Initialize the os module
513 os::init();
514
515 // Initialize memory pools
516 Arena::initialize_chunk_pool();
517
518 MACOS_AARCH64_ONLY(os::current_thread_enable_wx(WXWrite));
519
520 // Record VM creation timing statistics
521 TraceVmCreationTime create_vm_timer;
522 create_vm_timer.start();
523
524 // Initialize system properties.
525 Arguments::init_system_properties();
526
527 // So that JDK version can be used as a discriminator when parsing arguments
528 JDK_Version_init();
529
530 // Update/Initialize System properties after JDK version number is known
531 Arguments::init_version_specific_system_properties();
532
533 // Make sure to initialize log configuration *before* parsing arguments
534 LogConfiguration::initialize(create_vm_timer.begin_time());
535
536 // Parse arguments
537 // Note: this internally calls os::init_container_support()
538 jint parse_result = Arguments::parse(args);
539 if (parse_result != JNI_OK) return parse_result;
540
541 // Initialize NMT right after argument parsing to keep the pre-NMT-init window small.
542 MemTracker::initialize();
543
544 os::init_before_ergo();
545
546 jint ergo_result = Arguments::apply_ergo();
547 if (ergo_result != JNI_OK) return ergo_result;
548
549 // Final check of all ranges after ergonomics which may change values.
550 if (!JVMFlagLimit::check_all_ranges()) {
551 return JNI_EINVAL;
552 }
553
554 // Final check of all 'AfterErgo' constraints after ergonomics which may change values.
555 bool constraint_result = JVMFlagLimit::check_all_constraints(JVMFlagConstraintPhase::AfterErgo);
556 if (!constraint_result) {
557 return JNI_EINVAL;
558 }
559
560 if (PauseAtStartup) {
561 os::pause();
562 }
563
564 HOTSPOT_VM_INIT_BEGIN();
565
566 // Timing (must come after argument parsing)
567 TraceTime timer("Create VM", TRACETIME_LOG(Info, startuptime));
568
569 // Initialize the os module after parsing the args
570 jint os_init_2_result = os::init_2();
571 if (os_init_2_result != JNI_OK) return os_init_2_result;
572
573 #ifdef CAN_SHOW_REGISTERS_ON_ASSERT
574 // Initialize assert poison page mechanism.
575 if (ShowRegistersOnAssert) {
576 initialize_assert_poison();
577 }
578 #endif // CAN_SHOW_REGISTERS_ON_ASSERT
579
580 SafepointMechanism::initialize();
581
582 jint adjust_after_os_result = Arguments::adjust_after_os();
583 if (adjust_after_os_result != JNI_OK) return adjust_after_os_result;
584
585 // Initialize output stream logging
586 ostream_init_log();
587
588 // Launch -agentlib/-agentpath and converted -Xrun agents
589 JvmtiAgentList::load_agents();
590
591 // Initialize Threads state
592 _number_of_threads = 0;
593 _number_of_non_daemon_threads = 0;
594
595 // Initialize global data structures and create system classes in heap
596 vm_init_globals();
597
598 #if INCLUDE_JVMCI
599 if (JVMCICounterSize > 0) {
600 JavaThread::_jvmci_old_thread_counters = NEW_C_HEAP_ARRAY(jlong, JVMCICounterSize, mtJVMCI);
601 memset(JavaThread::_jvmci_old_thread_counters, 0, sizeof(jlong) * JVMCICounterSize);
602 } else {
603 JavaThread::_jvmci_old_thread_counters = nullptr;
604 }
605 #endif // INCLUDE_JVMCI
606
607 // Initialize OopStorage for threadObj
608 JavaThread::_thread_oop_storage = OopStorageSet::create_strong("Thread OopStorage", mtThread);
609
610 // Attach the main thread to this os thread
611 JavaThread* main_thread = new JavaThread();
612 main_thread->set_thread_state(_thread_in_vm);
613 main_thread->initialize_thread_current();
614 // Once mutexes and main_thread are ready, we can use NmtVirtualMemoryLocker.
615 MemTracker::NmtVirtualMemoryLocker::set_safe_to_use();
616 // must do this before set_active_handles
617 main_thread->record_stack_base_and_size();
618 main_thread->register_thread_stack_with_NMT();
619 main_thread->set_active_handles(JNIHandleBlock::allocate_block());
620 MACOS_AARCH64_ONLY(main_thread->init_wx());
621
622 MutexLockerImpl::init_counters(); // depends on mutex_init(), perfMemory_init(), and Thread::initialize_thread_current().
623
624 // Set the _monitor_owner_id now since we will run Java code before the Thread instance
625 // is even created. The same value will be assigned to the Thread instance on init.
626 main_thread->set_monitor_owner_id(ThreadIdentifier::next());
627
628 if (!Thread::set_as_starting_thread(main_thread)) {
629 vm_shutdown_during_initialization(
630 "Failed necessary internal allocation. Out of swap space");
631 main_thread->smr_delete();
632 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
633 return JNI_ENOMEM;
634 }
635
636 JFR_ONLY(Jfr::initialize_main_thread(main_thread);)
637
638 // Enable guard page *after* os::create_main_thread(), otherwise it would
639 // crash Linux VM, see notes in os_linux.cpp.
640 main_thread->stack_overflow_state()->create_stack_guard_pages();
641
642 // Initialize Java-Level synchronization subsystem
643 ObjectMonitor::Initialize();
644 ObjectSynchronizer::initialize();
645
646 Deoptimization::init_counters();
647 VMThread::init_counters();
648
649 // Initialize global modules
650 jint status = init_globals();
651 if (status != JNI_OK) {
652 main_thread->smr_delete();
653 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
654 return status;
655 }
656 if (xtty != nullptr)
657 xtty->elem("vm_main_thread thread='%zu'",
658 (uintx) main_thread->osthread()->thread_id());
659
660 // Have the WatcherThread read the release file in the background.
661 ReadReleaseFileTask* read_task = new ReadReleaseFileTask();
662 read_task->enroll();
663
664 // Create WatcherThread as soon as we can since we need it in case
665 // of hangs during error reporting.
666 WatcherThread::start();
667
668 // Add main_thread to threads list to finish barrier setup with
669 // on_thread_attach. Should be before starting to build Java objects in
670 // init_globals2, which invokes barriers.
671 {
672 MutexLocker mu(Threads_lock);
673 Threads::add(main_thread);
674 }
675
676 status = init_globals2();
677 if (status != JNI_OK) {
678 Threads::remove(main_thread, false);
679 // It is possible that we managed to fully initialize Universe but have then
680 // failed by throwing an exception. In that case our caller JNI_CreateJavaVM
681 // will want to report it, so we can't delete the main thread.
682 if (!main_thread->has_pending_exception()) {
683 main_thread->smr_delete();
684 }
685 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
686 return status;
687 }
688
689 ObjectMonitor::Initialize2();
690
691 JFR_ONLY(Jfr::on_create_vm_1();)
692
693 // Should be done after the heap is fully created
694 main_thread->cache_global_variables();
695
696 // Any JVMTI raw monitors entered in onload will transition into
697 // real raw monitor. VM is setup enough here for raw monitor enter.
698 JvmtiExport::transition_pending_onload_raw_monitors();
699
700 // Create the VMThread
701 { TraceTime timer("Start VMThread", TRACETIME_LOG(Info, startuptime));
702
703 VMThread::create();
704 VMThread* vmthread = VMThread::vm_thread();
705
706 if (!os::create_thread(vmthread, os::vm_thread)) {
707 vm_exit_during_initialization("Cannot create VM thread. "
708 "Out of system resources.");
709 }
710
711 // Wait for the VM thread to become ready, and VMThread::run to initialize
712 // Monitors can have spurious returns, must always check another state flag
713 {
714 MonitorLocker ml(Notify_lock);
715 os::start_thread(vmthread);
716 while (!vmthread->is_running()) {
717 ml.wait();
718 }
719 }
720 }
721
722 assert(Universe::is_fully_initialized(), "not initialized");
723 if (VerifyDuringStartup) {
724 // Make sure we're starting with a clean slate.
725 VM_Verify verify_op;
726 VMThread::execute(&verify_op);
727 }
728
729 // We need this to update the java.vm.info property in case any flags used
730 // to initially define it have been changed. This is needed for both CDS
731 // since UseSharedSpaces may be changed after java.vm.info
732 // is initially computed. See Abstract_VM_Version::vm_info_string().
733 // This update must happen before we initialize the java classes, but
734 // after any initialization logic that might modify the flags.
735 Arguments::update_vm_info_property(VM_Version::vm_info_string());
736
737 JavaThread* THREAD = JavaThread::current(); // For exception macros.
738 HandleMark hm(THREAD);
739
740 // Always call even when there are not JVMTI environments yet, since environments
741 // may be attached late and JVMTI must track phases of VM execution
742 JvmtiExport::enter_early_start_phase();
743
744 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
745 JvmtiExport::post_early_vm_start();
746
747 // Launch -Xrun agents early if EagerXrunInit is set
748 if (EagerXrunInit) {
749 JvmtiAgentList::load_xrun_agents();
750 }
751
752 initialize_java_lang_classes(main_thread, CHECK_JNI_ERR);
753
754 quicken_jni_functions();
755
756 // No more stub generation allowed after that point.
757 StubCodeDesc::freeze();
758
759 // Set flag that basic initialization has completed. Used by exceptions and various
760 // debug stuff, that does not work until all basic classes have been initialized.
761 set_init_completed();
762
763 LogConfiguration::post_initialize();
764 Metaspace::post_initialize();
765 MutexLockerImpl::post_initialize();
766
767 HOTSPOT_VM_INIT_END();
768
769 // record VM initialization completion time
770 #if INCLUDE_MANAGEMENT
771 Management::record_vm_init_completed();
772 #endif // INCLUDE_MANAGEMENT
773
774 log_info(os)("Initialized VM with process ID %d", os::current_process_id());
775
776 if (!FLAG_IS_DEFAULT(CreateCoredumpOnCrash) && CreateCoredumpOnCrash) {
777 char buffer[2*JVM_MAXPATHLEN];
778 os::check_core_dump_prerequisites(buffer, sizeof(buffer), true);
779 }
780
781 // Signal Dispatcher needs to be started before VMInit event is posted
782 os::initialize_jdk_signal_support(CHECK_JNI_ERR);
783
784 // Start Attach Listener if +StartAttachListener or it can't be started lazily
785 if (!DisableAttachMechanism) {
786 AttachListener::vm_start();
787 if (StartAttachListener || AttachListener::init_at_startup()) {
788 AttachListener::init();
789 }
790 }
791
792 // Launch -Xrun agents if EagerXrunInit is not set.
793 if (!EagerXrunInit) {
794 JvmtiAgentList::load_xrun_agents();
795 }
796
797 Arena::start_chunk_pool_cleaner_task();
798
799 // Start the service thread
800 // The service thread enqueues JVMTI deferred events and does various hashtable
801 // and other cleanups. Needs to start before the compilers start posting events.
802 ServiceThread::initialize();
803
804 // Start the monitor deflation thread:
805 MonitorDeflationThread::initialize();
806
807 #if INCLUDE_CDS
808 // Start the method sampler
809 MethodProfiler::initialize();
810 #endif
811
812 bool force_JVMCI_initialization = initialize_compilation(CHECK_JNI_ERR);
813
814 if (CDSConfig::is_using_aot_linked_classes()) {
815 SystemDictionary::restore_archived_method_handle_intrinsics();
816 AOTLinkedClassBulkLoader::link_or_init_javabase_classes(THREAD);
817 }
818
819 // Start string deduplication thread if requested.
820 if (StringDedup::is_enabled()) {
821 StringDedup::start();
822 }
823
824 // Pre-initialize some JSR292 core classes to avoid deadlock during class loading.
825 // It is done after compilers are initialized, because otherwise compilations of
826 // signature polymorphic MH intrinsics can be missed
827 // (see SystemDictionary::find_method_handle_intrinsic).
828 initialize_jsr292_core_classes(CHECK_JNI_ERR);
829
830 // This will initialize the module system. Only java.base classes can be
831 // loaded until phase 2 completes
832 call_initPhase2(CHECK_JNI_ERR);
833
834 if (CDSConfig::is_using_aot_linked_classes()) {
835 AOTLinkedClassBulkLoader::link_or_init_non_javabase_classes(THREAD);
836 }
837 #ifndef PRODUCT
838 HeapShared::initialize_test_class_from_archive(THREAD);
839 #endif
840
841 JFR_ONLY(Jfr::on_create_vm_2();)
842
843 // Always call even when there are not JVMTI environments yet, since environments
844 // may be attached late and JVMTI must track phases of VM execution
845 JvmtiExport::enter_start_phase();
846
847 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
848 JvmtiExport::post_vm_start();
849
850 // Final system initialization including security manager and system class loader
851 call_initPhase3(CHECK_JNI_ERR);
852
853 // cache the system and platform class loaders
854 SystemDictionary::compute_java_loaders(CHECK_JNI_ERR);
855
856 // Initiate replay training processing once preloading is over.
857 CompileBroker::init_training_replay();
858
859 AOTLinkedClassBulkLoader::replay_training_at_init_for_preloaded_classes(CHECK_JNI_ERR);
860
861 if (Continuations::enabled()) {
862 // Initialize Continuation class now so that failure to create enterSpecial/doYield
863 // special nmethods due to limited CodeCache size can be treated as a fatal error at
864 // startup with the proper message that CodeCache size is too small.
865 initialize_class(vmSymbols::jdk_internal_vm_Continuation(), CHECK_JNI_ERR);
866 }
867
868 #if INCLUDE_CDS
869 if (PrecompileCode) {
870 Precompiler::compile_aot_code(CHECK_JNI_ERR);
871 if (PrecompileOnlyAndExit) {
872 AOTCodeCache::close();
873 log_vm_init_stats();
874 vm_direct_exit(0, "Code precompiation is over");
875 }
876 }
877 #endif
878
879 #if defined(COMPILER2)
880 // Pre-load cached compiled methods
881 AOTCodeCache::preload_code(CHECK_JNI_ERR);
882 #endif
883
884 if (NativeHeapTrimmer::enabled()) {
885 NativeHeapTrimmer::initialize();
886 }
887
888 // Always call even when there are not JVMTI environments yet, since environments
889 // may be attached late and JVMTI must track phases of VM execution
890 JvmtiExport::enter_live_phase();
891
892 // Make perfmemory accessible
893 PerfMemory::set_accessible(true);
894
895 // Notify JVMTI agents that VM initialization is complete - nop if no agents.
896 JvmtiExport::post_vm_initialized();
897
898 #if INCLUDE_JVMCI
899 if (force_JVMCI_initialization) {
900 JVMCI::initialize_compiler_in_create_vm(CHECK_JNI_ERR);
901 }
902 #endif
903
904 JFR_ONLY(Jfr::on_create_vm_3();)
905
906 #if INCLUDE_MANAGEMENT
907 bool start_agent = true;
908 #if INCLUDE_CDS
909 start_agent = !CDSConfig::is_dumping_final_static_archive();
910 if (!start_agent) {
911 log_info(aot)("Not starting management agent during creation of AOT cache.");
912 }
913 #endif // INCLUDE_CDS
914 if (start_agent) {
915 Management::initialize(THREAD);
916
917 if (HAS_PENDING_EXCEPTION) {
918 // management agent fails to start possibly due to
919 // configuration problem and is responsible for printing
920 // stack trace if appropriate. Simply exit VM.
921 vm_exit(1);
922 }
923 }
924 #endif // INCLUDE_MANAGEMENT
925
926 if (UsePerfData) PerfDataManager::create_misc_perfdata();
927 if (CheckJNICalls) JniPeriodicChecker::engage();
928
929 call_postVMInitHook(THREAD);
930 // The Java side of PostVMInitHook.run must deal with all
931 // exceptions and provide means of diagnosis.
932 if (HAS_PENDING_EXCEPTION) {
933 CLEAR_PENDING_EXCEPTION;
934 }
935
936 // Let WatcherThread run all registered periodic tasks now.
937 // NOTE: All PeriodicTasks should be registered by now. If they
938 // aren't, late joiners might appear to start slowly (we might
939 // take a while to process their first tick).
940 WatcherThread::run_all_tasks();
941
942 create_vm_timer.end();
943 #ifdef ASSERT
944 _vm_complete = true;
945 #endif
946
947 if (CDSConfig::is_dumping_classic_static_archive()) {
948 // Classic -Xshare:dump, aka "old workflow"
949 AOTMetaspace::dump_static_archive(CHECK_JNI_ERR);
950 } else if (CDSConfig::is_dumping_final_static_archive()) {
951 tty->print_cr("Reading AOTConfiguration %s and writing AOTCache %s", AOTConfiguration, AOTCache);
952 AOTMetaspace::dump_static_archive(CHECK_JNI_ERR);
953 }
954
955 log_info(init)("At VM initialization completion:");
956 log_vm_init_stats();
957
958 if (UsePerfData) {
959 if (ProfileVMLocks) {
960 main_thread->set_profile_vm_locks(true);
961 }
962 if (ProfileVMCalls) {
963 main_thread->set_profile_vm_calls(true);
964 }
965 if (ProfileRuntimeCalls) {
966 main_thread->set_profile_rt_calls(true);
967 }
968 if (ProfileVMOps) {
969 main_thread->set_profile_vm_ops(true);
970 }
971 }
972
973 return JNI_OK;
974 }
975
976 // Threads::destroy_vm() is normally called from jni_DestroyJavaVM() when
977 // the program falls off the end of main(). Another VM exit path is through
978 // vm_exit(), when the program calls System.exit() to return a value, or when
979 // there is a serious error in VM.
980 // These two separate shutdown paths are not exactly the same, but they share
981 // Shutdown.shutdown() at Java level and before_exit() and VM_Exit op at VM level.
982 //
983 // Shutdown sequence:
984 // + Shutdown native memory tracking if it is on
985 // + Wait until we are the last non-daemon thread to execute
986 // <-- every thing is still working at this moment -->
987 // + Call java.lang.Shutdown.shutdown(), which will invoke Java level
988 // shutdown hooks
989 // + Call before_exit(), prepare for VM exit
990 // > run VM level shutdown hooks (they are registered through JVM_OnExit(),
991 // currently the only user of this mechanism is File.deleteOnExit())
992 // > stop watcher thread,
993 // post thread end and vm death events to JVMTI,
994 // stop signal thread
995 // + Call JavaThread::exit(), it will:
996 // > release JNI handle blocks, remove stack guard pages
997 // > remove this thread from Threads list
998 // <-- no more Java code from this thread after this point -->
999 // + Stop VM thread, it will bring the remaining VM to a safepoint and stop
1000 // the compiler threads at safepoint
1001 // <-- do not use anything that could get blocked by Safepoint -->
1002 // + Disable tracing at JNI/JVM barriers
1003 // + Set _vm_exited flag for threads that are still running native code
1004 // + Call exit_globals()
1005 // > deletes tty
1006 // > deletes PerfMemory resources
1007 // + Delete this thread
1008 // + Return to caller
1009
1010 void Threads::destroy_vm() {
1011 JavaThread* thread = JavaThread::current();
1012
1013 #ifdef ASSERT
1014 _vm_complete = false;
1015 #endif
1016 // Wait until we are the last non-daemon thread to execute, or
1017 // if we are a daemon then wait until the last non-daemon thread has
1018 // executed.
1019 bool daemon = java_lang_Thread::is_daemon(thread->threadObj());
1020 int expected = daemon ? 0 : 1;
1021 {
1022 MonitorLocker nu(Threads_lock);
1023 while (Threads::number_of_non_daemon_threads() > expected)
1024 // This wait should make safepoint checks, wait without a timeout.
1025 nu.wait(0);
1026 }
1027
1028 EventShutdown e;
1029 if (e.should_commit()) {
1030 e.set_reason("No remaining non-daemon Java threads");
1031 e.commit();
1032 }
1033
1034 // Hang forever on exit if we are reporting an error.
1035 if (ShowMessageBoxOnError && VMError::is_error_reported()) {
1036 os::infinite_sleep();
1037 }
1038 os::wait_for_keypress_at_exit();
1039
1040 // run Java level shutdown hooks
1041 thread->invoke_shutdown_hooks();
1042
1043 before_exit(thread);
1044
1045 thread->exit(true);
1046
1047 // We are no longer on the main thread list but could still be in a
1048 // secondary list where another thread may try to interact with us.
1049 // So wait until all such interactions are complete before we bring
1050 // the VM to the termination safepoint. Normally this would be done
1051 // using thread->smr_delete() below where we delete the thread, but
1052 // we can't call that after the termination safepoint is active as
1053 // we will deadlock on the Threads_lock. Once all interactions are
1054 // complete it is safe to directly delete the thread at any time.
1055 ThreadsSMRSupport::wait_until_not_protected(thread);
1056
1057 // Stop VM thread.
1058 {
1059 // 4945125 The vm thread comes to a safepoint during exit.
1060 // GC vm_operations can get caught at the safepoint, and the
1061 // heap is unparseable if they are caught. Grab the Heap_lock
1062 // to prevent this. The GC vm_operations will not be able to
1063 // queue until after the vm thread is dead. After this point,
1064 // we'll never emerge out of the safepoint before the VM exits.
1065 // Assert that the thread is terminated so that acquiring the
1066 // Heap_lock doesn't cause the terminated thread to participate in
1067 // the safepoint protocol.
1068
1069 assert(thread->is_terminated(), "must be terminated here");
1070 MutexLocker ml(Heap_lock);
1071
1072 VMThread::wait_for_vm_thread_exit();
1073 assert(SafepointSynchronize::is_at_safepoint(), "VM thread should exit at Safepoint");
1074 VMThread::destroy();
1075 }
1076
1077 // Now, all Java threads are gone except daemon threads. Daemon threads
1078 // running Java code or in VM are stopped by the Safepoint. However,
1079 // daemon threads executing native code are still running. But they
1080 // will be stopped at native=>Java/VM barriers. Note that we can't
1081 // simply kill or suspend them, as it is inherently deadlock-prone.
1082
1083 #if INCLUDE_CDS
1084 if (AOTVerifyTrainingData) {
1085 TrainingData::verify();
1086 }
1087 #endif
1088
1089 VM_Exit::set_vm_exited();
1090
1091 // Clean up ideal graph printers after the VMThread has started
1092 // the final safepoint which will block all the Compiler threads.
1093 // Note that this Thread has already logically exited so the
1094 // clean_up() function's use of a JavaThreadIteratorWithHandle
1095 // would be a problem except set_vm_exited() has remembered the
1096 // shutdown thread which is granted a policy exception.
1097 #if defined(COMPILER2) && !defined(PRODUCT)
1098 IdealGraphPrinter::clean_up();
1099 #endif
1100
1101 notify_vm_shutdown();
1102
1103 // exit_globals() will delete tty
1104 exit_globals();
1105
1106 // Deleting the shutdown thread here is safe. See comment on
1107 // wait_until_not_protected() above.
1108 delete thread;
1109
1110 #if INCLUDE_JVMCI
1111 if (JVMCICounterSize > 0) {
1112 FREE_C_HEAP_ARRAY(jlong, JavaThread::_jvmci_old_thread_counters);
1113 }
1114 #endif
1115
1116 LogConfiguration::finalize();
1117 }
1118
1119
1120 jboolean Threads::is_supported_jni_version_including_1_1(jint version) {
1121 if (version == JNI_VERSION_1_1) return JNI_TRUE;
1122 return is_supported_jni_version(version);
1123 }
1124
1125
1126 jboolean Threads::is_supported_jni_version(jint version) {
1127 if (version == JNI_VERSION_1_2) return JNI_TRUE;
1128 if (version == JNI_VERSION_1_4) return JNI_TRUE;
1129 if (version == JNI_VERSION_1_6) return JNI_TRUE;
1130 if (version == JNI_VERSION_1_8) return JNI_TRUE;
1131 if (version == JNI_VERSION_9) return JNI_TRUE;
1132 if (version == JNI_VERSION_10) return JNI_TRUE;
1133 if (version == JNI_VERSION_19) return JNI_TRUE;
1134 if (version == JNI_VERSION_20) return JNI_TRUE;
1135 if (version == JNI_VERSION_21) return JNI_TRUE;
1136 if (version == JNI_VERSION_24) return JNI_TRUE;
1137 return JNI_FALSE;
1138 }
1139
1140 void Threads::add(JavaThread* p, bool force_daemon) {
1141 // The threads lock must be owned at this point
1142 assert(Threads_lock->owned_by_self(), "must have threads lock");
1143 assert(p->monitor_owner_id() != 0, "should be set");
1144
1145 BarrierSet::barrier_set()->on_thread_attach(p);
1146
1147 // Once a JavaThread is added to the Threads list, smr_delete() has
1148 // to be used to delete it. Otherwise we can just delete it directly.
1149 p->set_on_thread_list();
1150
1151 _number_of_threads++;
1152 oop threadObj = p->threadObj();
1153 bool daemon = true;
1154 // Bootstrapping problem: threadObj can be null for initial
1155 // JavaThread (or for threads attached via JNI)
1156 if (!force_daemon &&
1157 (threadObj == nullptr || !java_lang_Thread::is_daemon(threadObj))) {
1158 _number_of_non_daemon_threads++;
1159 daemon = false;
1160 }
1161
1162 ThreadService::add_thread(p, daemon);
1163
1164 // Maintain fast thread list
1165 ThreadsSMRSupport::add_thread(p);
1166
1167 // Increase the ObjectMonitor ceiling for the new thread.
1168 ObjectSynchronizer::inc_in_use_list_ceiling();
1169
1170 // Possible GC point.
1171 Events::log(Thread::current(), "Thread added: " INTPTR_FORMAT, p2i(p));
1172
1173 // Make new thread known to active EscapeBarrier
1174 EscapeBarrier::thread_added(p);
1175 }
1176
1177 void Threads::remove(JavaThread* p, bool is_daemon) {
1178 // Extra scope needed for Thread_lock, so we can check
1179 // that we do not remove thread without safepoint code notice
1180 {
1181 ConditionalMutexLocker throttle_ml(ThreadsLockThrottle_lock, UseThreadsLockThrottleLock);
1182 MonitorLocker ml(Threads_lock);
1183
1184 if (ThreadIdTable::is_initialized()) {
1185 // This cleanup must be done before the current thread's GC barrier
1186 // is detached since we need to touch the threadObj oop.
1187 jlong tid = SharedRuntime::get_java_tid(p);
1188 ThreadIdTable::remove_thread(tid);
1189 }
1190
1191 // BarrierSet state must be destroyed after the last thread transition
1192 // before the thread terminates. Thread transitions result in calls to
1193 // StackWatermarkSet::on_safepoint(), which performs GC processing,
1194 // requiring the GC state to be alive.
1195 BarrierSet::barrier_set()->on_thread_detach(p);
1196 if (p->is_exiting()) {
1197 // If we got here via JavaThread::exit(), then we remember that the
1198 // thread's GC barrier has been detached. We don't do this when we get
1199 // here from another path, e.g., cleanup_failed_attach_current_thread().
1200 p->set_terminated(JavaThread::_thread_gc_barrier_detached);
1201 }
1202
1203 assert(ThreadsSMRSupport::get_java_thread_list()->includes(p), "p must be present");
1204
1205 // Maintain fast thread list
1206 ThreadsSMRSupport::remove_thread(p);
1207
1208 _number_of_threads--;
1209 if (!is_daemon) {
1210 _number_of_non_daemon_threads--;
1211
1212 // If this is the last non-daemon thread then we need to do
1213 // a notify on the Threads_lock so a thread waiting
1214 // on destroy_vm will wake up. But that thread could be a daemon
1215 // or non-daemon, so we notify for both the 0 and 1 case.
1216 if (number_of_non_daemon_threads() <= 1) {
1217 ml.notify_all();
1218 }
1219 }
1220 ThreadService::remove_thread(p, is_daemon);
1221
1222 // Make sure that safepoint code disregard this thread. This is needed since
1223 // the thread might mess around with locks after this point. This can cause it
1224 // to do callbacks into the safepoint code. However, the safepoint code is not aware
1225 // of this thread since it is removed from the queue.
1226 p->set_terminated(JavaThread::_thread_terminated);
1227
1228 // Notify threads waiting in EscapeBarriers
1229 EscapeBarrier::thread_removed(p);
1230 } // unlock Threads_lock and ThreadsLockThrottle_lock
1231
1232 // Reduce the ObjectMonitor ceiling for the exiting thread.
1233 ObjectSynchronizer::dec_in_use_list_ceiling();
1234
1235 // Since Events::log uses a lock, we grab it outside the Threads_lock
1236 Events::log(Thread::current(), "Thread exited: " INTPTR_FORMAT, p2i(p));
1237 }
1238
1239 // Operations on the Threads list for GC. These are not explicitly locked,
1240 // but the garbage collector must provide a safe context for them to run.
1241 // In particular, these things should never be called when the Threads_lock
1242 // is held by some other thread. (Note: the Safepoint abstraction also
1243 // uses the Threads_lock to guarantee this property. It also makes sure that
1244 // all threads gets blocked when exiting or starting).
1245
1246 void Threads::oops_do(OopClosure* f, NMethodClosure* cf) {
1247 ALL_JAVA_THREADS(p) {
1248 p->oops_do(f, cf);
1249 }
1250 VMThread::vm_thread()->oops_do(f, cf);
1251 }
1252
1253 void Threads::change_thread_claim_token() {
1254 if (++_thread_claim_token == 0) {
1255 // On overflow of the token counter, there is a risk of future
1256 // collisions between a new global token value and a stale token
1257 // for a thread, because not all iterations visit all threads.
1258 // (Though it's pretty much a theoretical concern for non-trivial
1259 // token counter sizes.) To deal with the possibility, reset all
1260 // the thread tokens to zero on global token overflow.
1261 struct ResetClaims : public ThreadClosure {
1262 virtual void do_thread(Thread* t) {
1263 t->claim_threads_do(false, 0);
1264 }
1265 } reset_claims;
1266 Threads::threads_do(&reset_claims);
1267 // On overflow, update the global token to non-zero, to
1268 // avoid the special "never claimed" initial thread value.
1269 _thread_claim_token = 1;
1270 }
1271 }
1272
1273 #ifdef ASSERT
1274 static void assert_thread_claimed(const char* kind, Thread* t, uintx expected) {
1275 const uintx token = t->threads_do_token();
1276 assert(token == expected,
1277 "%s " PTR_FORMAT " has incorrect value %zu != %zu",
1278 kind, p2i(t), token, expected);
1279 }
1280
1281 void Threads::assert_all_threads_claimed() {
1282 ALL_JAVA_THREADS(p) {
1283 assert_thread_claimed("JavaThread", p, _thread_claim_token);
1284 }
1285
1286 struct NJTClaimedVerifierClosure : public ThreadClosure {
1287 uintx _thread_claim_token;
1288
1289 NJTClaimedVerifierClosure(uintx thread_claim_token) : ThreadClosure(), _thread_claim_token(thread_claim_token) { }
1290
1291 virtual void do_thread(Thread* thread) override {
1292 assert_thread_claimed("Non-JavaThread", VMThread::vm_thread(), _thread_claim_token);
1293 }
1294 } tc(_thread_claim_token);
1295
1296 non_java_threads_do(&tc);
1297 }
1298 #endif // ASSERT
1299
1300 class ParallelOopsDoThreadClosure : public ThreadClosure {
1301 private:
1302 OopClosure* _f;
1303 NMethodClosure* _cf;
1304 public:
1305 ParallelOopsDoThreadClosure(OopClosure* f, NMethodClosure* cf) : _f(f), _cf(cf) {}
1306 void do_thread(Thread* t) {
1307 t->oops_do(_f, _cf);
1308 }
1309 };
1310
1311 void Threads::possibly_parallel_oops_do(bool is_par, OopClosure* f, NMethodClosure* cf) {
1312 ParallelOopsDoThreadClosure tc(f, cf);
1313 possibly_parallel_threads_do(is_par, &tc);
1314 }
1315
1316 void Threads::metadata_do(MetadataClosure* f) {
1317 ALL_JAVA_THREADS(p) {
1318 p->metadata_do(f);
1319 }
1320 }
1321
1322 class ThreadHandlesClosure : public ThreadClosure {
1323 void (*_f)(Metadata*);
1324 public:
1325 ThreadHandlesClosure(void f(Metadata*)) : _f(f) {}
1326 virtual void do_thread(Thread* thread) {
1327 thread->metadata_handles_do(_f);
1328 }
1329 };
1330
1331 void Threads::metadata_handles_do(void f(Metadata*)) {
1332 // Only walk the Handles in Thread.
1333 ThreadHandlesClosure handles_closure(f);
1334 threads_do(&handles_closure);
1335 }
1336
1337 #if INCLUDE_JVMTI
1338 // Get Java threads that are waiting to enter or re-enter the specified monitor.
1339 // Java threads that are executing mounted virtual threads are not included.
1340 GrowableArray<JavaThread*>* Threads::get_pending_threads(ThreadsList * t_list,
1341 int count,
1342 address monitor) {
1343 assert(Thread::current()->is_VM_thread(), "Must be the VM thread");
1344 GrowableArray<JavaThread*>* result = new GrowableArray<JavaThread*>(count);
1345
1346 int i = 0;
1347 for (JavaThread* p : *t_list) {
1348 if (!p->can_call_java()) continue;
1349
1350 oop thread_oop = JvmtiEnvBase::get_vthread_or_thread_oop(p);
1351 if (thread_oop->is_a(vmClasses::BaseVirtualThread_klass())) {
1352 continue;
1353 }
1354 // The first stage of async deflation does not affect any field
1355 // used by this comparison so the ObjectMonitor* is usable here.
1356 address pending = (address)p->current_pending_monitor();
1357 address waiting = (address)p->current_waiting_monitor();
1358 // do not include virtual threads to the list
1359 jint state = JvmtiEnvBase::get_thread_state(thread_oop, p);
1360 if (pending == monitor || (waiting == monitor &&
1361 (state & JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER))
1362 ) { // found a match
1363 if (i < count) result->append(p); // save the first count matches
1364 i++;
1365 }
1366 }
1367
1368 return result;
1369 }
1370 #endif // INCLUDE_JVMTI
1371
1372 JavaThread* Threads::owning_thread_from_object(ThreadsList * t_list, oop obj) {
1373 for (JavaThread* q : *t_list) {
1374 // Need to start processing before accessing oops in the thread.
1375 StackWatermark* watermark = StackWatermarkSet::get(q, StackWatermarkKind::gc);
1376 if (watermark != nullptr) {
1377 watermark->start_processing();
1378 }
1379
1380 if (q->lock_stack().contains(obj)) {
1381 return q;
1382 }
1383 }
1384 return nullptr;
1385 }
1386
1387 JavaThread* Threads::owning_thread_from_monitor(ThreadsList* t_list, ObjectMonitor* monitor) {
1388 if (monitor->has_anonymous_owner()) {
1389 return owning_thread_from_object(t_list, monitor->object());
1390 } else {
1391 JavaThread* the_owner = nullptr;
1392 for (JavaThread* q : *t_list) {
1393 if (monitor->has_owner(q)) {
1394 the_owner = q;
1395 break;
1396 }
1397 }
1398 return the_owner;
1399 }
1400 }
1401
1402 class PrintOnClosure : public ThreadClosure {
1403 private:
1404 outputStream* _st;
1405
1406 public:
1407 PrintOnClosure(outputStream* st) :
1408 _st(st) {}
1409
1410 virtual void do_thread(Thread* thread) {
1411 if (thread != nullptr) {
1412 thread->print_on(_st);
1413 _st->cr();
1414 }
1415 }
1416 };
1417
1418 // Threads::print_on() is called at safepoint by VM_PrintThreads operation.
1419 void Threads::print_on(outputStream* st, bool print_stacks,
1420 bool internal_format, bool print_concurrent_locks,
1421 bool print_extended_info) {
1422 char buf[32];
1423 st->print_raw_cr(os::local_time_string(buf, sizeof(buf)));
1424
1425 st->print_cr("Full thread dump %s (%s %s)",
1426 VM_Version::vm_name(),
1427 VM_Version::vm_release(),
1428 VM_Version::vm_info_string());
1429 JDK_Version::current().to_string(buf, sizeof(buf));
1430 const char* runtime_name = JDK_Version::runtime_name() != nullptr ?
1431 JDK_Version::runtime_name() : "";
1432 const char* runtime_version = JDK_Version::runtime_version() != nullptr ?
1433 JDK_Version::runtime_version() : "";
1434 const char* vendor_version = JDK_Version::runtime_vendor_version() != nullptr ?
1435 JDK_Version::runtime_vendor_version() : "";
1436 const char* jdk_debug_level = VM_Version::printable_jdk_debug_level() != nullptr ?
1437 VM_Version::printable_jdk_debug_level() : "";
1438
1439 st->print_cr(" JDK version: %s%s%s (%s) (%sbuild %s)", runtime_name,
1440 (*vendor_version != '\0') ? " " : "", vendor_version,
1441 buf, jdk_debug_level, runtime_version);
1442
1443 st->cr();
1444
1445 #if INCLUDE_SERVICES
1446 // Dump concurrent locks
1447 ConcurrentLocksDump concurrent_locks;
1448 if (print_concurrent_locks) {
1449 concurrent_locks.dump_at_safepoint();
1450 }
1451 #endif // INCLUDE_SERVICES
1452
1453 ThreadsSMRSupport::print_info_on(st);
1454 st->cr();
1455
1456 ALL_JAVA_THREADS(p) {
1457 ResourceMark rm;
1458 p->print_on(st, print_extended_info);
1459 if (print_stacks) {
1460 if (internal_format) {
1461 p->trace_stack();
1462 } else {
1463 p->print_stack_on(st);
1464 if (p->is_vthread_mounted()) {
1465 st->print_cr(" Mounted virtual thread #" INT64_FORMAT, java_lang_Thread::thread_id(p->vthread()));
1466 p->print_vthread_stack_on(st);
1467 }
1468 }
1469 }
1470 st->cr();
1471 #if INCLUDE_SERVICES
1472 if (print_concurrent_locks) {
1473 concurrent_locks.print_locks_on(p, st);
1474 }
1475 #endif // INCLUDE_SERVICES
1476 }
1477
1478 PrintOnClosure cl(st);
1479 non_java_threads_do(&cl);
1480
1481 st->flush();
1482 }
1483
1484 void Threads::print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
1485 int buflen, bool* found_current) {
1486 if (this_thread != nullptr) {
1487 bool is_current = (current == this_thread);
1488 *found_current = *found_current || is_current;
1489 st->print("%s", is_current ? "=>" : " ");
1490
1491 st->print(PTR_FORMAT, p2i(this_thread));
1492 st->print(" ");
1493 this_thread->print_on_error(st, buf, buflen);
1494 st->cr();
1495 }
1496 }
1497
1498 class PrintOnErrorClosure : public ThreadClosure {
1499 outputStream* _st;
1500 Thread* _current;
1501 char* _buf;
1502 int _buflen;
1503 bool* _found_current;
1504 unsigned _num_printed;
1505 public:
1506 PrintOnErrorClosure(outputStream* st, Thread* current, char* buf,
1507 int buflen, bool* found_current) :
1508 _st(st), _current(current), _buf(buf), _buflen(buflen), _found_current(found_current),
1509 _num_printed(0) {}
1510
1511 virtual void do_thread(Thread* thread) {
1512 _num_printed++;
1513 Threads::print_on_error(thread, _st, _current, _buf, _buflen, _found_current);
1514 }
1515
1516 unsigned num_printed() const { return _num_printed; }
1517 };
1518
1519 // Threads::print_on_error() is called by fatal error handler. It's possible
1520 // that VM is not at safepoint and/or current thread is inside signal handler.
1521 // Don't print stack trace, as the stack may not be walkable. Don't allocate
1522 // memory (even in resource area), it might deadlock the error handler.
1523 void Threads::print_on_error(outputStream* st, Thread* current, char* buf,
1524 int buflen) {
1525 ThreadsSMRSupport::print_info_on(st);
1526 st->cr();
1527
1528 bool found_current = false;
1529 st->print_cr("Java Threads: ( => current thread )");
1530 unsigned num_java = 0;
1531 ALL_JAVA_THREADS(thread) {
1532 print_on_error(thread, st, current, buf, buflen, &found_current);
1533 num_java++;
1534 }
1535 st->print_cr("Total: %u", num_java);
1536 st->cr();
1537
1538 st->print_cr("Other Threads:");
1539 unsigned num_other = ((VMThread::vm_thread() != nullptr) ? 1 : 0) +
1540 ((WatcherThread::watcher_thread() != nullptr) ? 1 : 0) +
1541 ((AsyncLogWriter::instance() != nullptr) ? 1 : 0);
1542 print_on_error(VMThread::vm_thread(), st, current, buf, buflen, &found_current);
1543 print_on_error(WatcherThread::watcher_thread(), st, current, buf, buflen, &found_current);
1544 print_on_error(AsyncLogWriter::instance(), st, current, buf, buflen, &found_current);
1545
1546 if (Universe::heap() != nullptr) {
1547 PrintOnErrorClosure print_closure(st, current, buf, buflen, &found_current);
1548 Universe::heap()->gc_threads_do(&print_closure);
1549 num_other += print_closure.num_printed();
1550 }
1551
1552 if (!found_current) {
1553 st->cr();
1554 st->print("=>" PTR_FORMAT " (exited) ", p2i(current));
1555 current->print_on_error(st, buf, buflen);
1556 num_other++;
1557 st->cr();
1558 }
1559 st->print_cr("Total: %u", num_other);
1560 st->cr();
1561
1562 st->print_cr("Threads with active compile tasks:");
1563 unsigned num = print_threads_compiling(st, buf, buflen);
1564 st->print_cr("Total: %u", num);
1565 }
1566
1567 unsigned Threads::print_threads_compiling(outputStream* st, char* buf, int buflen, bool short_form) {
1568 unsigned num = 0;
1569 ALL_JAVA_THREADS(thread) {
1570 if (thread->is_Compiler_thread()) {
1571 CompilerThread* ct = (CompilerThread*) thread;
1572
1573 // Keep task in local variable for null check.
1574 // ct->_task might be set to null by concurring compiler thread
1575 // because it completed the compilation. The task is never freed,
1576 // though, just returned to a free list.
1577 CompileTask* task = ct->task();
1578 if (task != nullptr) {
1579 thread->print_name_on_error(st, buf, buflen);
1580 st->print(" ");
1581 task->print(st, nullptr, short_form, true);
1582 num++;
1583 }
1584 }
1585 }
1586 return num;
1587 }
1588
1589 void Threads::verify() {
1590 ALL_JAVA_THREADS(p) {
1591 p->verify();
1592 }
1593 VMThread* thread = VMThread::vm_thread();
1594 if (thread != nullptr) thread->verify();
1595 }