1
2 /*
3 * Copyright (c) 1997, 2025, Oracle and/or its affiliates. All rights reserved.
4 * Copyright (c) 2021, Azul Systems, Inc. All rights reserved.
5 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
6 *
7 * This code is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License version 2 only, as
9 * published by the Free Software Foundation.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 *
25 */
26
27 #include "cds/aotLinkedClassBulkLoader.hpp"
28 #include "cds/cds_globals.hpp"
29 #include "cds/cdsConfig.hpp"
30 #include "cds/heapShared.hpp"
31 #include "cds/metaspaceShared.hpp"
32 #include "cds/methodProfiler.hpp"
33 #include "classfile/classLoader.hpp"
34 #include "classfile/javaClasses.hpp"
35 #include "classfile/javaThreadStatus.hpp"
36 #include "classfile/symbolTable.hpp"
37 #include "classfile/systemDictionary.hpp"
38 #include "classfile/systemDictionaryShared.hpp"
39 #include "classfile/vmClasses.hpp"
40 #include "classfile/vmSymbols.hpp"
41 #include "code/aotCodeCache.hpp"
42 #include "compiler/compilationPolicy.hpp"
43 #include "compiler/compileBroker.hpp"
44 #include "compiler/compileTask.hpp"
45 #include "compiler/compilerThread.hpp"
46 #include "compiler/precompiler.hpp"
47 #include "gc/shared/barrierSet.hpp"
48 #include "gc/shared/barrierSetNMethod.hpp"
49 #include "gc/shared/gcVMOperations.hpp"
50 #include "gc/shared/oopStorage.hpp"
51 #include "gc/shared/oopStorageSet.hpp"
52 #include "gc/shared/stringdedup/stringDedup.hpp"
53 #include "interpreter/interpreterRuntime.hpp"
54 #include "jfr/jfrEvents.hpp"
55 #include "jvm.h"
56 #include "jvmtifiles/jvmtiEnv.hpp"
57 #include "logging/log.hpp"
58 #include "logging/logAsyncWriter.hpp"
59 #include "logging/logConfiguration.hpp"
60 #include "memory/allocation.inline.hpp"
61 #include "memory/iterator.hpp"
62 #include "memory/oopFactory.hpp"
63 #include "memory/resourceArea.hpp"
64 #include "memory/universe.hpp"
65 #include "nmt/memTracker.hpp"
66 #include "oops/instanceKlass.hpp"
67 #include "oops/klass.inline.hpp"
68 #include "oops/oop.inline.hpp"
69 #include "oops/symbol.hpp"
70 #include "prims/jvm_misc.hpp"
71 #include "prims/jvmtiAgentList.hpp"
72 #include "prims/jvmtiEnvBase.hpp"
73 #include "runtime/arguments.hpp"
74 #include "runtime/fieldDescriptor.inline.hpp"
75 #include "runtime/flags/jvmFlagLimit.hpp"
76 #include "runtime/globals.hpp"
77 #include "runtime/globals_extension.hpp"
78 #include "runtime/handles.inline.hpp"
79 #include "runtime/interfaceSupport.inline.hpp"
80 #include "runtime/java.hpp"
81 #include "runtime/javaCalls.hpp"
82 #include "runtime/javaThread.inline.hpp"
83 #include "runtime/jniHandles.inline.hpp"
84 #include "runtime/jniPeriodicChecker.hpp"
85 #include "runtime/lockStack.inline.hpp"
86 #include "runtime/monitorDeflationThread.hpp"
87 #include "runtime/mutexLocker.hpp"
88 #include "runtime/nonJavaThread.hpp"
89 #include "runtime/objectMonitor.inline.hpp"
90 #include "runtime/osThread.hpp"
91 #include "runtime/perfData.hpp"
92 #include "runtime/safepoint.hpp"
93 #include "runtime/safepointMechanism.inline.hpp"
94 #include "runtime/safepointVerifiers.hpp"
95 #include "runtime/serviceThread.hpp"
96 #include "runtime/sharedRuntime.hpp"
97 #include "runtime/stackWatermarkSet.inline.hpp"
98 #include "runtime/stubCodeGenerator.hpp"
99 #include "runtime/thread.inline.hpp"
100 #include "runtime/threadSMR.inline.hpp"
101 #include "runtime/threads.hpp"
102 #include "runtime/timer.hpp"
103 #include "runtime/timerTrace.hpp"
104 #include "runtime/trimNativeHeap.hpp"
105 #include "runtime/vmOperations.hpp"
106 #include "runtime/vm_version.hpp"
107 #include "services/attachListener.hpp"
108 #include "services/management.hpp"
109 #include "services/threadIdTable.hpp"
110 #include "services/threadService.hpp"
111 #include "utilities/dtrace.hpp"
112 #include "utilities/events.hpp"
113 #include "utilities/macros.hpp"
114 #include "utilities/vmError.hpp"
115 #if INCLUDE_JVMCI
116 #include "jvmci/jvmci.hpp"
117 #include "jvmci/jvmciEnv.hpp"
118 #endif
119 #ifdef COMPILER1
120 #include "c1/c1_Runtime1.hpp"
121 #endif
122 #ifdef COMPILER2
123 #include "opto/idealGraphPrinter.hpp"
124 #include "opto/runtime.hpp"
125 #endif
126 #if INCLUDE_JFR
127 #include "jfr/jfr.hpp"
128 #endif
129
130 // Initialization after module runtime initialization
131 void universe_post_module_init(); // must happen after call_initPhase2
132
133
134 static void initialize_class(Symbol* class_name, TRAPS) {
135 Klass* klass = SystemDictionary::resolve_or_fail(class_name, true, CHECK);
136 InstanceKlass::cast(klass)->initialize(CHECK);
137 }
138
139
140 // Creates the initial ThreadGroup
141 static Handle create_initial_thread_group(TRAPS) {
142 Handle system_instance = JavaCalls::construct_new_instance(
143 vmClasses::ThreadGroup_klass(),
144 vmSymbols::void_method_signature(),
145 CHECK_NH);
146 Universe::set_system_thread_group(system_instance());
147
148 Handle string = java_lang_String::create_from_str("main", CHECK_NH);
149 Handle main_instance = JavaCalls::construct_new_instance(
150 vmClasses::ThreadGroup_klass(),
151 vmSymbols::threadgroup_string_void_signature(),
152 system_instance,
153 string,
154 CHECK_NH);
155 return main_instance;
156 }
157
158 // Creates the initial Thread, and sets it to running.
159 static void create_initial_thread(Handle thread_group, JavaThread* thread,
160 TRAPS) {
161 InstanceKlass* ik = vmClasses::Thread_klass();
162 assert(ik->is_initialized(), "must be");
163 instanceHandle thread_oop = ik->allocate_instance_handle(CHECK);
164
165 // Cannot use JavaCalls::construct_new_instance because the java.lang.Thread
166 // constructor calls Thread.current(), which must be set here for the
167 // initial thread.
168 java_lang_Thread::set_thread(thread_oop(), thread);
169 thread->set_threadOopHandles(thread_oop());
170
171 Handle string = java_lang_String::create_from_str("main", CHECK);
172
173 JavaValue result(T_VOID);
174 JavaCalls::call_special(&result, thread_oop,
175 ik,
176 vmSymbols::object_initializer_name(),
177 vmSymbols::threadgroup_string_void_signature(),
178 thread_group,
179 string,
180 CHECK);
181
182 DEBUG_ONLY(int64_t main_thread_tid = java_lang_Thread::thread_id(thread_oop());)
183 assert(main_thread_tid == ThreadIdentifier::initial(), "");
184 assert(main_thread_tid == thread->monitor_owner_id(), "");
185 JFR_ONLY(assert(JFR_JVM_THREAD_ID(thread) == static_cast<traceid>(main_thread_tid), "initial tid mismatch");)
186
187 // Set thread status to running since main thread has
188 // been started and running.
189 java_lang_Thread::set_thread_status(thread_oop(),
190 JavaThreadStatus::RUNNABLE);
191 }
192
193 // Extract version and vendor specific information from
194 // java.lang.VersionProps fields.
195 // Returned char* is allocated in the thread's resource area
196 // so must be copied for permanency.
197 static const char* get_java_version_info(InstanceKlass* ik,
198 Symbol* field_name) {
199 fieldDescriptor fd;
200 bool found = ik != nullptr &&
201 ik->find_local_field(field_name,
202 vmSymbols::string_signature(), &fd);
203 if (found) {
204 oop name_oop = ik->java_mirror()->obj_field(fd.offset());
205 if (name_oop == nullptr) {
206 return nullptr;
207 }
208 const char* name = java_lang_String::as_utf8_string(name_oop);
209 return name;
210 } else {
211 return nullptr;
212 }
213 }
214
215 // ======= Threads ========
216
217 // The Threads class links together all active threads, and provides
218 // operations over all threads. It is protected by the Threads_lock,
219 // which is also used in other global contexts like safepointing.
220 // ThreadsListHandles are used to safely perform operations on one
221 // or more threads without the risk of the thread exiting during the
222 // operation.
223 //
224 // Note: The Threads_lock is currently more widely used than we
225 // would like. We are actively migrating Threads_lock uses to other
226 // mechanisms in order to reduce Threads_lock contention.
227
228 int Threads::_number_of_threads = 0;
229 int Threads::_number_of_non_daemon_threads = 0;
230 int Threads::_return_code = 0;
231 uintx Threads::_thread_claim_token = 1; // Never zero.
232
233 #ifdef ASSERT
234 bool Threads::_vm_complete = false;
235 #endif
236
237 // General purpose hook into Java code, run once when the VM is initialized.
238 // The Java library method itself may be changed independently from the VM.
239 static void call_postVMInitHook(TRAPS) {
240 Klass* klass = SystemDictionary::resolve_or_null(vmSymbols::jdk_internal_vm_PostVMInitHook(), THREAD);
241 if (klass != nullptr) {
242 JavaValue result(T_VOID);
243 JavaCalls::call_static(&result, klass, vmSymbols::run_method_name(),
244 vmSymbols::void_method_signature(),
245 CHECK);
246 }
247 }
248
249 // All NonJavaThreads (i.e., every non-JavaThread in the system).
250 void Threads::non_java_threads_do(ThreadClosure* tc) {
251 NoSafepointVerifier nsv;
252 for (NonJavaThread::Iterator njti; !njti.end(); njti.step()) {
253 tc->do_thread(njti.current());
254 }
255 }
256
257 // All JavaThreads
258 #define ALL_JAVA_THREADS(X) \
259 for (JavaThread* X : *ThreadsSMRSupport::get_java_thread_list())
260
261 // All JavaThreads
262 void Threads::java_threads_do(ThreadClosure* tc) {
263 assert_locked_or_safepoint(Threads_lock);
264 // ALL_JAVA_THREADS iterates through all JavaThreads.
265 ALL_JAVA_THREADS(p) {
266 tc->do_thread(p);
267 }
268 }
269
270 // All JavaThreads + all non-JavaThreads (i.e., every thread in the system).
271 void Threads::threads_do(ThreadClosure* tc) {
272 assert_locked_or_safepoint(Threads_lock);
273 java_threads_do(tc);
274 non_java_threads_do(tc);
275 }
276
277 void Threads::possibly_parallel_threads_do(bool is_par, ThreadClosure* tc) {
278 assert_at_safepoint();
279
280 uintx claim_token = Threads::thread_claim_token();
281 ALL_JAVA_THREADS(p) {
282 if (p->claim_threads_do(is_par, claim_token)) {
283 tc->do_thread(p);
284 }
285 }
286 for (NonJavaThread::Iterator njti; !njti.end(); njti.step()) {
287 Thread* current = njti.current();
288 if (current->claim_threads_do(is_par, claim_token)) {
289 tc->do_thread(current);
290 }
291 }
292 }
293
294 // The system initialization in the library has three phases.
295 //
296 // Phase 1: java.lang.System class initialization
297 // java.lang.System is a primordial class loaded and initialized
298 // by the VM early during startup. java.lang.System.<clinit>
299 // only does registerNatives and keeps the rest of the class
300 // initialization work later until thread initialization completes.
301 //
302 // System.initPhase1 initializes the system properties, the static
303 // fields in, out, and err. Set up java signal handlers, OS-specific
304 // system settings, and thread group of the main thread.
305 static void call_initPhase1(TRAPS) {
306 Klass* klass = vmClasses::System_klass();
307 JavaValue result(T_VOID);
308 JavaCalls::call_static(&result, klass, vmSymbols::initPhase1_name(),
309 vmSymbols::void_method_signature(), CHECK);
310 }
311
312 // Phase 2. Module system initialization
313 // This will initialize the module system. Only java.base classes
314 // can be loaded until phase 2 completes.
315 //
316 // Call System.initPhase2 after the compiler initialization and jsr292
317 // classes get initialized because module initialization runs a lot of java
318 // code, that for performance reasons, should be compiled. Also, this will
319 // enable the startup code to use lambda and other language features in this
320 // phase and onward.
321 //
322 // After phase 2, The VM will begin search classes from -Xbootclasspath/a.
323 static void call_initPhase2(TRAPS) {
324 TraceTime timer("Initialize module system", TRACETIME_LOG(Info, startuptime));
325
326 Klass* klass = vmClasses::System_klass();
327
328 JavaValue result(T_INT);
329 JavaCallArguments args;
330 args.push_int(DisplayVMOutputToStderr);
331 args.push_int(log_is_enabled(Debug, init)); // print stack trace if exception thrown
332 JavaCalls::call_static(&result, klass, vmSymbols::initPhase2_name(),
333 vmSymbols::boolean_boolean_int_signature(), &args, CHECK);
334 if (result.get_jint() != JNI_OK) {
335 vm_exit_during_initialization(); // no message or exception
336 }
337
338 universe_post_module_init();
339
340 #if 0
341 if (CDSConfig::is_using_aot_linked_classes()) {
342 AOTLinkedClassBulkLoader::load_non_javabase_boot_classes(THREAD);
343 if (CDSConfig::is_using_full_module_graph()) {
344 assert(SystemDictionary::java_platform_loader() != nullptr, "must be");
345 assert(SystemDictionary::java_system_loader() != nullptr, "must be");
346 AOTLinkedClassBulkLoader::load_platform_classes(THREAD);
347 AOTLinkedClassBulkLoader::load_app_classes(THREAD);
348 } else {
349 // Special case -- we assume that the final archive has the same module graph
350 // as the training run.
351 // AOTLinkedClassBulkLoader will be called for the platform/system loaders
352 // inside SystemDictionary::compute_java_loaders().
353 assert(CDSConfig::is_dumping_final_static_archive(), "must be");
354 assert(SystemDictionary::java_platform_loader() == nullptr, "must be");
355 assert(SystemDictionary::java_system_loader() == nullptr, "must be");
356 }
357 }
358
359 #ifndef PRODUCT
360 HeapShared::initialize_test_class_from_archive(THREAD);
361 #endif
362 #endif
363 }
364
365 // Phase 3. final setup - set security manager, system class loader and TCCL
366 //
367 // This will instantiate and set the security manager, set the system class
368 // loader as well as the thread context class loader. The security manager
369 // and system class loader may be a custom class loaded from -Xbootclasspath/a,
370 // other modules or the application's classpath.
371 static void call_initPhase3(TRAPS) {
372 Klass* klass = vmClasses::System_klass();
373 JavaValue result(T_VOID);
374 JavaCalls::call_static(&result, klass, vmSymbols::initPhase3_name(),
375 vmSymbols::void_method_signature(), CHECK);
376 }
377
378 void Threads::initialize_java_lang_classes(JavaThread* main_thread, TRAPS) {
379 TraceTime timer("Initialize java.lang classes", TRACETIME_LOG(Info, startuptime));
380
381 initialize_class(vmSymbols::java_lang_String(), CHECK);
382
383 // Inject CompactStrings value after the static initializers for String ran.
384 java_lang_String::set_compact_strings(CompactStrings);
385
386 // Initialize java_lang.System (needed before creating the thread)
387 initialize_class(vmSymbols::java_lang_System(), CHECK);
388 // The VM creates & returns objects of this class. Make sure it's initialized.
389 initialize_class(vmSymbols::java_lang_Class(), CHECK);
390
391 initialize_class(vmSymbols::java_lang_ThreadGroup(), CHECK);
392 Handle thread_group = create_initial_thread_group(CHECK);
393 Universe::set_main_thread_group(thread_group());
394 initialize_class(vmSymbols::java_lang_Thread(), CHECK);
395 create_initial_thread(thread_group, main_thread, CHECK);
396
397 HeapShared::init_box_classes(CHECK);
398
399 // The VM creates objects of this class.
400 initialize_class(vmSymbols::java_lang_Module(), CHECK);
401
402 #ifdef ASSERT
403 InstanceKlass *k = vmClasses::UnsafeConstants_klass();
404 assert(k->is_not_initialized(), "UnsafeConstants should not already be initialized");
405 #endif
406
407 // initialize the hardware-specific constants needed by Unsafe
408 initialize_class(vmSymbols::jdk_internal_misc_UnsafeConstants(), CHECK);
409 jdk_internal_misc_UnsafeConstants::set_unsafe_constants();
410
411 // The VM preresolves methods to these classes. Make sure that they get initialized
412 initialize_class(vmSymbols::java_lang_reflect_Method(), CHECK);
413 initialize_class(vmSymbols::java_lang_ref_Finalizer(), CHECK);
414
415 // Phase 1 of the system initialization in the library, java.lang.System class initialization
416 call_initPhase1(CHECK);
417
418 // Get the Java runtime name, version, and vendor info after java.lang.System is initialized.
419 // Some values are actually configure-time constants but some can be set via the jlink tool and
420 // so must be read dynamically. We treat them all the same.
421 InstanceKlass* ik = SystemDictionary::find_instance_klass(THREAD, vmSymbols::java_lang_VersionProps(),
422 Handle());
423 {
424 ResourceMark rm(main_thread);
425 JDK_Version::set_java_version(get_java_version_info(ik, vmSymbols::java_version_name()));
426
427 JDK_Version::set_runtime_name(get_java_version_info(ik, vmSymbols::java_runtime_name_name()));
428
429 JDK_Version::set_runtime_version(get_java_version_info(ik, vmSymbols::java_runtime_version_name()));
430
431 JDK_Version::set_runtime_vendor_version(get_java_version_info(ik, vmSymbols::java_runtime_vendor_version_name()));
432
433 JDK_Version::set_runtime_vendor_vm_bug_url(get_java_version_info(ik, vmSymbols::java_runtime_vendor_vm_bug_url_name()));
434 }
435
436 // an instance of OutOfMemory exception has been allocated earlier
437 initialize_class(vmSymbols::java_lang_OutOfMemoryError(), CHECK);
438 initialize_class(vmSymbols::java_lang_NullPointerException(), CHECK);
439 initialize_class(vmSymbols::java_lang_ClassCastException(), CHECK);
440 initialize_class(vmSymbols::java_lang_ArrayStoreException(), CHECK);
441 initialize_class(vmSymbols::java_lang_ArithmeticException(), CHECK);
442 initialize_class(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), CHECK);
443 initialize_class(vmSymbols::java_lang_StackOverflowError(), CHECK);
444 initialize_class(vmSymbols::java_lang_IllegalMonitorStateException(), CHECK);
445 initialize_class(vmSymbols::java_lang_IllegalArgumentException(), CHECK);
446 initialize_class(vmSymbols::java_lang_InternalError(), CHECK);
447 }
448
449 bool Threads::initialize_compilation(TRAPS) {
450 // initialize compiler(s)
451 bool force_JVMCI_initialization = false;
452
453 #if defined(COMPILER1) || COMPILER2_OR_JVMCI
454 bool init_compilation = true;
455 #if INCLUDE_JVMCI
456 if (EnableJVMCI) {
457 // Initialize JVMCI eagerly when it is explicitly requested.
458 // Or when JVMCILibDumpJNIConfig or JVMCIPrintProperties is enabled.
459 force_JVMCI_initialization = EagerJVMCI || JVMCIPrintProperties || JVMCILibDumpJNIConfig;
460 if (!force_JVMCI_initialization && UseJVMCICompiler && !UseJVMCINativeLibrary && (!UseInterpreter || !BackgroundCompilation)) {
461 // Force initialization of jarjvmci otherwise requests for blocking
462 // compilations will not actually block until jarjvmci is initialized.
463 force_JVMCI_initialization = true;
464 }
465 if (JVMCIPrintProperties || JVMCILibDumpJNIConfig) {
466 // Both JVMCILibDumpJNIConfig and JVMCIPrintProperties exit the VM
467 // so compilation should be disabled. This prevents dumping or
468 // printing from happening more than once.
469 init_compilation = false;
470 }
471 }
472 #endif
473 if (init_compilation) {
474 CompileBroker::compilation_init(CHECK_false);
475 }
476 #endif
477
478 return force_JVMCI_initialization;
479 }
480
481 void Threads::initialize_jsr292_core_classes(TRAPS) {
482 TraceTime timer("Initialize java.lang.invoke classes", TRACETIME_LOG(Info, startuptime));
483
484 initialize_class(vmSymbols::java_lang_invoke_MethodHandle(), CHECK);
485 initialize_class(vmSymbols::java_lang_invoke_ResolvedMethodName(), CHECK);
486 initialize_class(vmSymbols::java_lang_invoke_MemberName(), CHECK);
487 initialize_class(vmSymbols::java_lang_invoke_MethodHandleNatives(), CHECK);
488
489 if (UseSharedSpaces) {
490 HeapShared::initialize_java_lang_invoke(CHECK);
491 }
492 }
493
494 // One-shot PeriodicTask subclass for reading the release file
495 class ReadReleaseFileTask : public PeriodicTask {
496 public:
497 ReadReleaseFileTask() : PeriodicTask(100) {}
498
499 virtual void task() {
500 os::read_image_release_file();
501
502 // Reclaim our storage and disenroll ourself.
503 delete this;
504 }
505 };
506
507 jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) {
508 extern void JDK_Version_init();
509
510 // Preinitialize version info.
511 VM_Version::early_initialize();
512
513 // Check version
514 if (!is_supported_jni_version(args->version)) return JNI_EVERSION;
515
516 // Initialize library-based TLS
517 ThreadLocalStorage::init();
518
519 // Initialize the output stream module
520 ostream_init();
521
522 // Process java launcher properties.
523 Arguments::process_sun_java_launcher_properties(args);
524
525 // Initialize the os module
526 os::init();
527
528 // Initialize memory pools
529 Arena::initialize_chunk_pool();
530
531 MACOS_AARCH64_ONLY(os::current_thread_enable_wx(WXWrite));
532
533 // Record VM creation timing statistics
534 TraceVmCreationTime create_vm_timer;
535 create_vm_timer.start();
536
537 // Initialize system properties.
538 Arguments::init_system_properties();
539
540 // So that JDK version can be used as a discriminator when parsing arguments
541 JDK_Version_init();
542
543 // Update/Initialize System properties after JDK version number is known
544 Arguments::init_version_specific_system_properties();
545
546 // Make sure to initialize log configuration *before* parsing arguments
547 LogConfiguration::initialize(create_vm_timer.begin_time());
548
549 // Parse arguments
550 // Note: this internally calls os::init_container_support()
551 jint parse_result = Arguments::parse(args);
552 if (parse_result != JNI_OK) return parse_result;
553
554 // Initialize NMT right after argument parsing to keep the pre-NMT-init window small.
555 MemTracker::initialize();
556
557 os::init_before_ergo();
558
559 jint ergo_result = Arguments::apply_ergo();
560 if (ergo_result != JNI_OK) return ergo_result;
561
562 // Final check of all ranges after ergonomics which may change values.
563 if (!JVMFlagLimit::check_all_ranges()) {
564 return JNI_EINVAL;
565 }
566
567 // Final check of all 'AfterErgo' constraints after ergonomics which may change values.
568 bool constraint_result = JVMFlagLimit::check_all_constraints(JVMFlagConstraintPhase::AfterErgo);
569 if (!constraint_result) {
570 return JNI_EINVAL;
571 }
572
573 if (PauseAtStartup) {
574 os::pause();
575 }
576
577 HOTSPOT_VM_INIT_BEGIN();
578
579 // Timing (must come after argument parsing)
580 TraceTime timer("Create VM", TRACETIME_LOG(Info, startuptime));
581
582 // Initialize the os module after parsing the args
583 jint os_init_2_result = os::init_2();
584 if (os_init_2_result != JNI_OK) return os_init_2_result;
585
586 #ifdef CAN_SHOW_REGISTERS_ON_ASSERT
587 // Initialize assert poison page mechanism.
588 if (ShowRegistersOnAssert) {
589 initialize_assert_poison();
590 }
591 #endif // CAN_SHOW_REGISTERS_ON_ASSERT
592
593 SafepointMechanism::initialize();
594
595 jint adjust_after_os_result = Arguments::adjust_after_os();
596 if (adjust_after_os_result != JNI_OK) return adjust_after_os_result;
597
598 // Initialize output stream logging
599 ostream_init_log();
600
601 // Launch -agentlib/-agentpath and converted -Xrun agents
602 JvmtiAgentList::load_agents();
603
604 // Initialize Threads state
605 _number_of_threads = 0;
606 _number_of_non_daemon_threads = 0;
607
608 // Initialize global data structures and create system classes in heap
609 vm_init_globals();
610
611 #if INCLUDE_JVMCI
612 if (JVMCICounterSize > 0) {
613 JavaThread::_jvmci_old_thread_counters = NEW_C_HEAP_ARRAY(jlong, JVMCICounterSize, mtJVMCI);
614 memset(JavaThread::_jvmci_old_thread_counters, 0, sizeof(jlong) * JVMCICounterSize);
615 } else {
616 JavaThread::_jvmci_old_thread_counters = nullptr;
617 }
618 #endif // INCLUDE_JVMCI
619
620 // Initialize OopStorage for threadObj
621 JavaThread::_thread_oop_storage = OopStorageSet::create_strong("Thread OopStorage", mtThread);
622
623 // Attach the main thread to this os thread
624 JavaThread* main_thread = new JavaThread();
625 main_thread->set_thread_state(_thread_in_vm);
626 main_thread->initialize_thread_current();
627 // Once mutexes and main_thread are ready, we can use NmtVirtualMemoryLocker.
628 MemTracker::NmtVirtualMemoryLocker::set_safe_to_use();
629 // must do this before set_active_handles
630 main_thread->record_stack_base_and_size();
631 main_thread->register_thread_stack_with_NMT();
632 main_thread->set_active_handles(JNIHandleBlock::allocate_block());
633 MACOS_AARCH64_ONLY(main_thread->init_wx());
634
635 MutexLockerImpl::init_counters(); // depends on mutex_init(), perfMemory_init(), and Thread::initialize_thread_current().
636
637 // Set the _monitor_owner_id now since we will run Java code before the Thread instance
638 // is even created. The same value will be assigned to the Thread instance on init.
639 main_thread->set_monitor_owner_id(ThreadIdentifier::next());
640
641 if (!Thread::set_as_starting_thread(main_thread)) {
642 vm_shutdown_during_initialization(
643 "Failed necessary internal allocation. Out of swap space");
644 main_thread->smr_delete();
645 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
646 return JNI_ENOMEM;
647 }
648
649 JFR_ONLY(Jfr::initialize_main_thread(main_thread);)
650
651 // Enable guard page *after* os::create_main_thread(), otherwise it would
652 // crash Linux VM, see notes in os_linux.cpp.
653 main_thread->stack_overflow_state()->create_stack_guard_pages();
654
655 // Initialize Java-Level synchronization subsystem
656 ObjectMonitor::Initialize();
657 ObjectSynchronizer::initialize();
658
659 Deoptimization::init_counters();
660 VMThread::init_counters();
661
662 // Initialize global modules
663 jint status = init_globals();
664 if (status != JNI_OK) {
665 main_thread->smr_delete();
666 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
667 return status;
668 }
669 if (xtty != nullptr)
670 xtty->elem("vm_main_thread thread='%zu'",
671 (uintx) main_thread->osthread()->thread_id());
672
673 // Have the WatcherThread read the release file in the background.
674 ReadReleaseFileTask* read_task = new ReadReleaseFileTask();
675 read_task->enroll();
676
677 // Create WatcherThread as soon as we can since we need it in case
678 // of hangs during error reporting.
679 WatcherThread::start();
680
681 // Add main_thread to threads list to finish barrier setup with
682 // on_thread_attach. Should be before starting to build Java objects in
683 // init_globals2, which invokes barriers.
684 {
685 MutexLocker mu(Threads_lock);
686 Threads::add(main_thread);
687 }
688
689 status = init_globals2();
690 if (status != JNI_OK) {
691 Threads::remove(main_thread, false);
692 // It is possible that we managed to fully initialize Universe but have then
693 // failed by throwing an exception. In that case our caller JNI_CreateJavaVM
694 // will want to report it, so we can't delete the main thread.
695 if (!main_thread->has_pending_exception()) {
696 main_thread->smr_delete();
697 }
698 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
699 return status;
700 }
701
702 ObjectMonitor::Initialize2();
703
704 JFR_ONLY(Jfr::on_create_vm_1();)
705
706 // Should be done after the heap is fully created
707 main_thread->cache_global_variables();
708
709 // Any JVMTI raw monitors entered in onload will transition into
710 // real raw monitor. VM is setup enough here for raw monitor enter.
711 JvmtiExport::transition_pending_onload_raw_monitors();
712
713 // Create the VMThread
714 { TraceTime timer("Start VMThread", TRACETIME_LOG(Info, startuptime));
715
716 VMThread::create();
717 VMThread* vmthread = VMThread::vm_thread();
718
719 if (!os::create_thread(vmthread, os::vm_thread)) {
720 vm_exit_during_initialization("Cannot create VM thread. "
721 "Out of system resources.");
722 }
723
724 // Wait for the VM thread to become ready, and VMThread::run to initialize
725 // Monitors can have spurious returns, must always check another state flag
726 {
727 MonitorLocker ml(Notify_lock);
728 os::start_thread(vmthread);
729 while (!vmthread->is_running()) {
730 ml.wait();
731 }
732 }
733 }
734
735 assert(Universe::is_fully_initialized(), "not initialized");
736 if (VerifyDuringStartup) {
737 // Make sure we're starting with a clean slate.
738 VM_Verify verify_op;
739 VMThread::execute(&verify_op);
740 }
741
742 // We need this to update the java.vm.info property in case any flags used
743 // to initially define it have been changed. This is needed for both CDS
744 // since UseSharedSpaces may be changed after java.vm.info
745 // is initially computed. See Abstract_VM_Version::vm_info_string().
746 // This update must happen before we initialize the java classes, but
747 // after any initialization logic that might modify the flags.
748 Arguments::update_vm_info_property(VM_Version::vm_info_string());
749
750 JavaThread* THREAD = JavaThread::current(); // For exception macros.
751 HandleMark hm(THREAD);
752
753 // Always call even when there are not JVMTI environments yet, since environments
754 // may be attached late and JVMTI must track phases of VM execution
755 JvmtiExport::enter_early_start_phase();
756
757 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
758 JvmtiExport::post_early_vm_start();
759
760 // Launch -Xrun agents early if EagerXrunInit is set
761 if (EagerXrunInit) {
762 JvmtiAgentList::load_xrun_agents();
763 }
764
765 initialize_java_lang_classes(main_thread, CHECK_JNI_ERR);
766
767 quicken_jni_functions();
768
769 // No more stub generation allowed after that point.
770 StubCodeDesc::freeze();
771
772 // Set flag that basic initialization has completed. Used by exceptions and various
773 // debug stuff, that does not work until all basic classes have been initialized.
774 set_init_completed();
775
776 LogConfiguration::post_initialize();
777 Metaspace::post_initialize();
778 MutexLockerImpl::post_initialize();
779
780 HOTSPOT_VM_INIT_END();
781
782 // record VM initialization completion time
783 #if INCLUDE_MANAGEMENT
784 Management::record_vm_init_completed();
785 #endif // INCLUDE_MANAGEMENT
786
787 log_info(os)("Initialized VM with process ID %d", os::current_process_id());
788
789 if (!FLAG_IS_DEFAULT(CreateCoredumpOnCrash) && CreateCoredumpOnCrash) {
790 char buffer[2*JVM_MAXPATHLEN];
791 os::check_core_dump_prerequisites(buffer, sizeof(buffer), true);
792 }
793
794 // Signal Dispatcher needs to be started before VMInit event is posted
795 os::initialize_jdk_signal_support(CHECK_JNI_ERR);
796
797 // Start Attach Listener if +StartAttachListener or it can't be started lazily
798 if (!DisableAttachMechanism) {
799 AttachListener::vm_start();
800 if (StartAttachListener || AttachListener::init_at_startup()) {
801 AttachListener::init();
802 }
803 }
804
805 // Launch -Xrun agents if EagerXrunInit is not set.
806 if (!EagerXrunInit) {
807 JvmtiAgentList::load_xrun_agents();
808 }
809
810 Arena::start_chunk_pool_cleaner_task();
811
812 // Start the service thread
813 // The service thread enqueues JVMTI deferred events and does various hashtable
814 // and other cleanups. Needs to start before the compilers start posting events.
815 ServiceThread::initialize();
816
817 // Start the monitor deflation thread:
818 MonitorDeflationThread::initialize();
819
820 #if INCLUDE_CDS
821 // Start the method sampler
822 MethodProfiler::initialize();
823 #endif
824
825 bool force_JVMCI_initialization = initialize_compilation(CHECK_JNI_ERR);
826
827 if (CDSConfig::is_using_aot_linked_classes()) {
828 AOTLinkedClassBulkLoader::finish_loading_javabase_classes(CHECK_JNI_ERR);
829 SystemDictionary::restore_archived_method_handle_intrinsics();
830 }
831
832 // Start string deduplication thread if requested.
833 if (StringDedup::is_enabled()) {
834 StringDedup::start();
835 }
836
837 // Pre-initialize some JSR292 core classes to avoid deadlock during class loading.
838 // It is done after compilers are initialized, because otherwise compilations of
839 // signature polymorphic MH intrinsics can be missed
840 // (see SystemDictionary::find_method_handle_intrinsic).
841 initialize_jsr292_core_classes(CHECK_JNI_ERR);
842
843 // This will initialize the module system. Only java.base classes can be
844 // loaded until phase 2 completes
845 call_initPhase2(CHECK_JNI_ERR);
846
847 if (CDSConfig::is_using_aot_linked_classes() && !CDSConfig::is_dumping_final_static_archive()) {
848 AOTLinkedClassBulkLoader::load_non_javabase_classes(THREAD);
849 }
850 #ifndef PRODUCT
851 HeapShared::initialize_test_class_from_archive(THREAD);
852 #endif
853
854 JFR_ONLY(Jfr::on_create_vm_2();)
855
856 // Always call even when there are not JVMTI environments yet, since environments
857 // may be attached late and JVMTI must track phases of VM execution
858 JvmtiExport::enter_start_phase();
859
860 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
861 JvmtiExport::post_vm_start();
862
863 // Final system initialization including security manager and system class loader
864 call_initPhase3(CHECK_JNI_ERR);
865
866 // cache the system and platform class loaders
867 SystemDictionary::compute_java_loaders(CHECK_JNI_ERR);
868
869 // Initiate replay training processing once preloading is over.
870 CompileBroker::init_training_replay();
871
872 AOTLinkedClassBulkLoader::replay_training_at_init_for_preloaded_classes(CHECK_JNI_ERR);
873
874 if (Continuations::enabled()) {
875 // Initialize Continuation class now so that failure to create enterSpecial/doYield
876 // special nmethods due to limited CodeCache size can be treated as a fatal error at
877 // startup with the proper message that CodeCache size is too small.
878 initialize_class(vmSymbols::jdk_internal_vm_Continuation(), CHECK_JNI_ERR);
879 }
880
881 #if INCLUDE_CDS
882 if (PrecompileCode) {
883 Precompiler::compile_cached_code(CHECK_JNI_ERR);
884 if (PrecompileOnlyAndExit) {
885 AOTCodeCache::close();
886 log_vm_init_stats();
887 vm_direct_exit(0, "Code precompiation is over");
888 }
889 }
890 #endif
891
892 #if defined(COMPILER2)
893 // Pre-load cached compiled methods
894 AOTCodeCache::preload_code(CHECK_JNI_ERR);
895 #endif
896
897 if (NativeHeapTrimmer::enabled()) {
898 NativeHeapTrimmer::initialize();
899 }
900
901 // Always call even when there are not JVMTI environments yet, since environments
902 // may be attached late and JVMTI must track phases of VM execution
903 JvmtiExport::enter_live_phase();
904
905 // Make perfmemory accessible
906 PerfMemory::set_accessible(true);
907
908 // Notify JVMTI agents that VM initialization is complete - nop if no agents.
909 JvmtiExport::post_vm_initialized();
910
911 #if INCLUDE_JVMCI
912 if (force_JVMCI_initialization) {
913 JVMCI::initialize_compiler_in_create_vm(CHECK_JNI_ERR);
914 }
915 #endif
916
917 JFR_ONLY(Jfr::on_create_vm_3();)
918
919 #if INCLUDE_MANAGEMENT
920 Management::initialize(THREAD);
921
922 if (HAS_PENDING_EXCEPTION) {
923 // management agent fails to start possibly due to
924 // configuration problem and is responsible for printing
925 // stack trace if appropriate. Simply exit VM.
926 vm_exit(1);
927 }
928 #endif // INCLUDE_MANAGEMENT
929
930 if (UsePerfData) PerfDataManager::create_misc_perfdata();
931 if (CheckJNICalls) JniPeriodicChecker::engage();
932
933 call_postVMInitHook(THREAD);
934 // The Java side of PostVMInitHook.run must deal with all
935 // exceptions and provide means of diagnosis.
936 if (HAS_PENDING_EXCEPTION) {
937 CLEAR_PENDING_EXCEPTION;
938 }
939
940 // Let WatcherThread run all registered periodic tasks now.
941 // NOTE: All PeriodicTasks should be registered by now. If they
942 // aren't, late joiners might appear to start slowly (we might
943 // take a while to process their first tick).
944 WatcherThread::run_all_tasks();
945
946 create_vm_timer.end();
947 #ifdef ASSERT
948 _vm_complete = true;
949 #endif
950
951 if (CDSConfig::is_dumping_classic_static_archive()) {
952 // Classic -Xshare:dump, aka "old workflow"
953 MetaspaceShared::preload_and_dump(CHECK_JNI_ERR);
954 } else if (CDSConfig::is_dumping_final_static_archive()) {
955 if (CDSConfig::is_experimental_leyden_workflow()) {
956 // TODO: copy the verification and loader constraints from preimage to final image
957 // TODO: load archived classes for custom loaders as well.
958 log_info(cds)("Dumping final image of CacheDataStore %s", CacheDataStore);
959 MetaspaceShared::preload_and_dump(CHECK_JNI_ERR);
960 vm_direct_exit(0, "CacheDataStore dumping is complete");
961 } else {
962 tty->print_cr("Reading AOTConfiguration %s and writing AOTCache %s", AOTConfiguration, AOTCache);
963 MetaspaceShared::preload_and_dump(CHECK_JNI_ERR);
964 }
965 }
966
967 log_info(init)("At VM initialization completion:");
968 log_vm_init_stats();
969
970 if (UsePerfData) {
971 if (ProfileVMLocks) {
972 main_thread->set_profile_vm_locks(true);
973 }
974 if (ProfileVMCalls) {
975 main_thread->set_profile_vm_calls(true);
976 }
977 if (ProfileRuntimeCalls) {
978 main_thread->set_profile_rt_calls(true);
979 }
980 if (ProfileVMOps) {
981 main_thread->set_profile_vm_ops(true);
982 }
983 }
984
985 return JNI_OK;
986 }
987
988 // Threads::destroy_vm() is normally called from jni_DestroyJavaVM() when
989 // the program falls off the end of main(). Another VM exit path is through
990 // vm_exit(), when the program calls System.exit() to return a value, or when
991 // there is a serious error in VM.
992 // These two separate shutdown paths are not exactly the same, but they share
993 // Shutdown.shutdown() at Java level and before_exit() and VM_Exit op at VM level.
994 //
995 // Shutdown sequence:
996 // + Shutdown native memory tracking if it is on
997 // + Wait until we are the last non-daemon thread to execute
998 // <-- every thing is still working at this moment -->
999 // + Call java.lang.Shutdown.shutdown(), which will invoke Java level
1000 // shutdown hooks
1001 // + Call before_exit(), prepare for VM exit
1002 // > run VM level shutdown hooks (they are registered through JVM_OnExit(),
1003 // currently the only user of this mechanism is File.deleteOnExit())
1004 // > stop watcher thread,
1005 // post thread end and vm death events to JVMTI,
1006 // stop signal thread
1007 // + Call JavaThread::exit(), it will:
1008 // > release JNI handle blocks, remove stack guard pages
1009 // > remove this thread from Threads list
1010 // <-- no more Java code from this thread after this point -->
1011 // + Stop VM thread, it will bring the remaining VM to a safepoint and stop
1012 // the compiler threads at safepoint
1013 // <-- do not use anything that could get blocked by Safepoint -->
1014 // + Disable tracing at JNI/JVM barriers
1015 // + Set _vm_exited flag for threads that are still running native code
1016 // + Call exit_globals()
1017 // > deletes tty
1018 // > deletes PerfMemory resources
1019 // + Delete this thread
1020 // + Return to caller
1021
1022 void Threads::destroy_vm() {
1023 JavaThread* thread = JavaThread::current();
1024
1025 #ifdef ASSERT
1026 _vm_complete = false;
1027 #endif
1028 // Wait until we are the last non-daemon thread to execute, or
1029 // if we are a daemon then wait until the last non-daemon thread has
1030 // executed.
1031 bool daemon = java_lang_Thread::is_daemon(thread->threadObj());
1032 int expected = daemon ? 0 : 1;
1033 {
1034 MonitorLocker nu(Threads_lock);
1035 while (Threads::number_of_non_daemon_threads() > expected)
1036 // This wait should make safepoint checks, wait without a timeout.
1037 nu.wait(0);
1038 }
1039
1040 EventShutdown e;
1041 if (e.should_commit()) {
1042 e.set_reason("No remaining non-daemon Java threads");
1043 e.commit();
1044 }
1045
1046 // Hang forever on exit if we are reporting an error.
1047 if (ShowMessageBoxOnError && VMError::is_error_reported()) {
1048 os::infinite_sleep();
1049 }
1050 os::wait_for_keypress_at_exit();
1051
1052 // run Java level shutdown hooks
1053 thread->invoke_shutdown_hooks();
1054
1055 before_exit(thread);
1056
1057 thread->exit(true);
1058
1059 // We are no longer on the main thread list but could still be in a
1060 // secondary list where another thread may try to interact with us.
1061 // So wait until all such interactions are complete before we bring
1062 // the VM to the termination safepoint. Normally this would be done
1063 // using thread->smr_delete() below where we delete the thread, but
1064 // we can't call that after the termination safepoint is active as
1065 // we will deadlock on the Threads_lock. Once all interactions are
1066 // complete it is safe to directly delete the thread at any time.
1067 ThreadsSMRSupport::wait_until_not_protected(thread);
1068
1069 // Stop VM thread.
1070 {
1071 // 4945125 The vm thread comes to a safepoint during exit.
1072 // GC vm_operations can get caught at the safepoint, and the
1073 // heap is unparseable if they are caught. Grab the Heap_lock
1074 // to prevent this. The GC vm_operations will not be able to
1075 // queue until after the vm thread is dead. After this point,
1076 // we'll never emerge out of the safepoint before the VM exits.
1077 // Assert that the thread is terminated so that acquiring the
1078 // Heap_lock doesn't cause the terminated thread to participate in
1079 // the safepoint protocol.
1080
1081 assert(thread->is_terminated(), "must be terminated here");
1082 MutexLocker ml(Heap_lock);
1083
1084 VMThread::wait_for_vm_thread_exit();
1085 assert(SafepointSynchronize::is_at_safepoint(), "VM thread should exit at Safepoint");
1086 VMThread::destroy();
1087 }
1088
1089 // Now, all Java threads are gone except daemon threads. Daemon threads
1090 // running Java code or in VM are stopped by the Safepoint. However,
1091 // daemon threads executing native code are still running. But they
1092 // will be stopped at native=>Java/VM barriers. Note that we can't
1093 // simply kill or suspend them, as it is inherently deadlock-prone.
1094
1095 VM_Exit::set_vm_exited();
1096
1097 // Clean up ideal graph printers after the VMThread has started
1098 // the final safepoint which will block all the Compiler threads.
1099 // Note that this Thread has already logically exited so the
1100 // clean_up() function's use of a JavaThreadIteratorWithHandle
1101 // would be a problem except set_vm_exited() has remembered the
1102 // shutdown thread which is granted a policy exception.
1103 #if defined(COMPILER2) && !defined(PRODUCT)
1104 IdealGraphPrinter::clean_up();
1105 #endif
1106
1107 notify_vm_shutdown();
1108
1109 // exit_globals() will delete tty
1110 exit_globals();
1111
1112 // Deleting the shutdown thread here is safe. See comment on
1113 // wait_until_not_protected() above.
1114 delete thread;
1115
1116 #if INCLUDE_JVMCI
1117 if (JVMCICounterSize > 0) {
1118 FREE_C_HEAP_ARRAY(jlong, JavaThread::_jvmci_old_thread_counters);
1119 }
1120 #endif
1121
1122 LogConfiguration::finalize();
1123 }
1124
1125
1126 jboolean Threads::is_supported_jni_version_including_1_1(jint version) {
1127 if (version == JNI_VERSION_1_1) return JNI_TRUE;
1128 return is_supported_jni_version(version);
1129 }
1130
1131
1132 jboolean Threads::is_supported_jni_version(jint version) {
1133 if (version == JNI_VERSION_1_2) return JNI_TRUE;
1134 if (version == JNI_VERSION_1_4) return JNI_TRUE;
1135 if (version == JNI_VERSION_1_6) return JNI_TRUE;
1136 if (version == JNI_VERSION_1_8) return JNI_TRUE;
1137 if (version == JNI_VERSION_9) return JNI_TRUE;
1138 if (version == JNI_VERSION_10) return JNI_TRUE;
1139 if (version == JNI_VERSION_19) return JNI_TRUE;
1140 if (version == JNI_VERSION_20) return JNI_TRUE;
1141 if (version == JNI_VERSION_21) return JNI_TRUE;
1142 if (version == JNI_VERSION_24) return JNI_TRUE;
1143 return JNI_FALSE;
1144 }
1145
1146 void Threads::add(JavaThread* p, bool force_daemon) {
1147 // The threads lock must be owned at this point
1148 assert(Threads_lock->owned_by_self(), "must have threads lock");
1149 assert(p->monitor_owner_id() != 0, "should be set");
1150
1151 BarrierSet::barrier_set()->on_thread_attach(p);
1152
1153 // Once a JavaThread is added to the Threads list, smr_delete() has
1154 // to be used to delete it. Otherwise we can just delete it directly.
1155 p->set_on_thread_list();
1156
1157 _number_of_threads++;
1158 oop threadObj = p->threadObj();
1159 bool daemon = true;
1160 // Bootstrapping problem: threadObj can be null for initial
1161 // JavaThread (or for threads attached via JNI)
1162 if (!force_daemon &&
1163 (threadObj == nullptr || !java_lang_Thread::is_daemon(threadObj))) {
1164 _number_of_non_daemon_threads++;
1165 daemon = false;
1166 }
1167
1168 ThreadService::add_thread(p, daemon);
1169
1170 // Maintain fast thread list
1171 ThreadsSMRSupport::add_thread(p);
1172
1173 // Increase the ObjectMonitor ceiling for the new thread.
1174 ObjectSynchronizer::inc_in_use_list_ceiling();
1175
1176 // Possible GC point.
1177 Events::log(Thread::current(), "Thread added: " INTPTR_FORMAT, p2i(p));
1178
1179 // Make new thread known to active EscapeBarrier
1180 EscapeBarrier::thread_added(p);
1181 }
1182
1183 void Threads::remove(JavaThread* p, bool is_daemon) {
1184 // Extra scope needed for Thread_lock, so we can check
1185 // that we do not remove thread without safepoint code notice
1186 {
1187 ConditionalMutexLocker throttle_ml(ThreadsLockThrottle_lock, UseThreadsLockThrottleLock);
1188 MonitorLocker ml(Threads_lock);
1189
1190 if (ThreadIdTable::is_initialized()) {
1191 // This cleanup must be done before the current thread's GC barrier
1192 // is detached since we need to touch the threadObj oop.
1193 jlong tid = SharedRuntime::get_java_tid(p);
1194 ThreadIdTable::remove_thread(tid);
1195 }
1196
1197 // BarrierSet state must be destroyed after the last thread transition
1198 // before the thread terminates. Thread transitions result in calls to
1199 // StackWatermarkSet::on_safepoint(), which performs GC processing,
1200 // requiring the GC state to be alive.
1201 BarrierSet::barrier_set()->on_thread_detach(p);
1202 if (p->is_exiting()) {
1203 // If we got here via JavaThread::exit(), then we remember that the
1204 // thread's GC barrier has been detached. We don't do this when we get
1205 // here from another path, e.g., cleanup_failed_attach_current_thread().
1206 p->set_terminated(JavaThread::_thread_gc_barrier_detached);
1207 }
1208
1209 assert(ThreadsSMRSupport::get_java_thread_list()->includes(p), "p must be present");
1210
1211 // Maintain fast thread list
1212 ThreadsSMRSupport::remove_thread(p);
1213
1214 _number_of_threads--;
1215 if (!is_daemon) {
1216 _number_of_non_daemon_threads--;
1217
1218 // If this is the last non-daemon thread then we need to do
1219 // a notify on the Threads_lock so a thread waiting
1220 // on destroy_vm will wake up. But that thread could be a daemon
1221 // or non-daemon, so we notify for both the 0 and 1 case.
1222 if (number_of_non_daemon_threads() <= 1) {
1223 ml.notify_all();
1224 }
1225 }
1226 ThreadService::remove_thread(p, is_daemon);
1227
1228 // Make sure that safepoint code disregard this thread. This is needed since
1229 // the thread might mess around with locks after this point. This can cause it
1230 // to do callbacks into the safepoint code. However, the safepoint code is not aware
1231 // of this thread since it is removed from the queue.
1232 p->set_terminated(JavaThread::_thread_terminated);
1233
1234 // Notify threads waiting in EscapeBarriers
1235 EscapeBarrier::thread_removed(p);
1236 } // unlock Threads_lock and ThreadsLockThrottle_lock
1237
1238 // Reduce the ObjectMonitor ceiling for the exiting thread.
1239 ObjectSynchronizer::dec_in_use_list_ceiling();
1240
1241 // Since Events::log uses a lock, we grab it outside the Threads_lock
1242 Events::log(Thread::current(), "Thread exited: " INTPTR_FORMAT, p2i(p));
1243 }
1244
1245 // Operations on the Threads list for GC. These are not explicitly locked,
1246 // but the garbage collector must provide a safe context for them to run.
1247 // In particular, these things should never be called when the Threads_lock
1248 // is held by some other thread. (Note: the Safepoint abstraction also
1249 // uses the Threads_lock to guarantee this property. It also makes sure that
1250 // all threads gets blocked when exiting or starting).
1251
1252 void Threads::oops_do(OopClosure* f, NMethodClosure* cf) {
1253 ALL_JAVA_THREADS(p) {
1254 p->oops_do(f, cf);
1255 }
1256 VMThread::vm_thread()->oops_do(f, cf);
1257 }
1258
1259 void Threads::change_thread_claim_token() {
1260 if (++_thread_claim_token == 0) {
1261 // On overflow of the token counter, there is a risk of future
1262 // collisions between a new global token value and a stale token
1263 // for a thread, because not all iterations visit all threads.
1264 // (Though it's pretty much a theoretical concern for non-trivial
1265 // token counter sizes.) To deal with the possibility, reset all
1266 // the thread tokens to zero on global token overflow.
1267 struct ResetClaims : public ThreadClosure {
1268 virtual void do_thread(Thread* t) {
1269 t->claim_threads_do(false, 0);
1270 }
1271 } reset_claims;
1272 Threads::threads_do(&reset_claims);
1273 // On overflow, update the global token to non-zero, to
1274 // avoid the special "never claimed" initial thread value.
1275 _thread_claim_token = 1;
1276 }
1277 }
1278
1279 #ifdef ASSERT
1280 static void assert_thread_claimed(const char* kind, Thread* t, uintx expected) {
1281 const uintx token = t->threads_do_token();
1282 assert(token == expected,
1283 "%s " PTR_FORMAT " has incorrect value %zu != %zu",
1284 kind, p2i(t), token, expected);
1285 }
1286
1287 void Threads::assert_all_threads_claimed() {
1288 ALL_JAVA_THREADS(p) {
1289 assert_thread_claimed("JavaThread", p, _thread_claim_token);
1290 }
1291
1292 struct NJTClaimedVerifierClosure : public ThreadClosure {
1293 uintx _thread_claim_token;
1294
1295 NJTClaimedVerifierClosure(uintx thread_claim_token) : ThreadClosure(), _thread_claim_token(thread_claim_token) { }
1296
1297 virtual void do_thread(Thread* thread) override {
1298 assert_thread_claimed("Non-JavaThread", VMThread::vm_thread(), _thread_claim_token);
1299 }
1300 } tc(_thread_claim_token);
1301
1302 non_java_threads_do(&tc);
1303 }
1304 #endif // ASSERT
1305
1306 class ParallelOopsDoThreadClosure : public ThreadClosure {
1307 private:
1308 OopClosure* _f;
1309 NMethodClosure* _cf;
1310 public:
1311 ParallelOopsDoThreadClosure(OopClosure* f, NMethodClosure* cf) : _f(f), _cf(cf) {}
1312 void do_thread(Thread* t) {
1313 t->oops_do(_f, _cf);
1314 }
1315 };
1316
1317 void Threads::possibly_parallel_oops_do(bool is_par, OopClosure* f, NMethodClosure* cf) {
1318 ParallelOopsDoThreadClosure tc(f, cf);
1319 possibly_parallel_threads_do(is_par, &tc);
1320 }
1321
1322 void Threads::metadata_do(MetadataClosure* f) {
1323 ALL_JAVA_THREADS(p) {
1324 p->metadata_do(f);
1325 }
1326 }
1327
1328 class ThreadHandlesClosure : public ThreadClosure {
1329 void (*_f)(Metadata*);
1330 public:
1331 ThreadHandlesClosure(void f(Metadata*)) : _f(f) {}
1332 virtual void do_thread(Thread* thread) {
1333 thread->metadata_handles_do(_f);
1334 }
1335 };
1336
1337 void Threads::metadata_handles_do(void f(Metadata*)) {
1338 // Only walk the Handles in Thread.
1339 ThreadHandlesClosure handles_closure(f);
1340 threads_do(&handles_closure);
1341 }
1342
1343 #if INCLUDE_JVMTI
1344 // Get Java threads that are waiting to enter or re-enter the specified monitor.
1345 // Java threads that are executing mounted virtual threads are not included.
1346 GrowableArray<JavaThread*>* Threads::get_pending_threads(ThreadsList * t_list,
1347 int count,
1348 address monitor) {
1349 assert(Thread::current()->is_VM_thread(), "Must be the VM thread");
1350 GrowableArray<JavaThread*>* result = new GrowableArray<JavaThread*>(count);
1351
1352 int i = 0;
1353 for (JavaThread* p : *t_list) {
1354 if (!p->can_call_java()) continue;
1355
1356 oop thread_oop = JvmtiEnvBase::get_vthread_or_thread_oop(p);
1357 if (thread_oop->is_a(vmClasses::BaseVirtualThread_klass())) {
1358 continue;
1359 }
1360 // The first stage of async deflation does not affect any field
1361 // used by this comparison so the ObjectMonitor* is usable here.
1362 address pending = (address)p->current_pending_monitor();
1363 address waiting = (address)p->current_waiting_monitor();
1364 // do not include virtual threads to the list
1365 jint state = JvmtiEnvBase::get_thread_state(thread_oop, p);
1366 if (pending == monitor || (waiting == monitor &&
1367 (state & JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER))
1368 ) { // found a match
1369 if (i < count) result->append(p); // save the first count matches
1370 i++;
1371 }
1372 }
1373
1374 return result;
1375 }
1376 #endif // INCLUDE_JVMTI
1377
1378 JavaThread *Threads::owning_thread_from_stacklock(ThreadsList * t_list, address basicLock) {
1379 assert(LockingMode == LM_LEGACY, "Not with new lightweight locking");
1380
1381 JavaThread* the_owner = nullptr;
1382 for (JavaThread* q : *t_list) {
1383 if (q->is_lock_owned(basicLock)) {
1384 the_owner = q;
1385 break;
1386 }
1387 }
1388 return the_owner;
1389 }
1390
1391 JavaThread* Threads::owning_thread_from_object(ThreadsList * t_list, oop obj) {
1392 assert(LockingMode == LM_LIGHTWEIGHT, "Only with new lightweight locking");
1393 for (JavaThread* q : *t_list) {
1394 // Need to start processing before accessing oops in the thread.
1395 StackWatermark* watermark = StackWatermarkSet::get(q, StackWatermarkKind::gc);
1396 if (watermark != nullptr) {
1397 watermark->start_processing();
1398 }
1399
1400 if (q->lock_stack().contains(obj)) {
1401 return q;
1402 }
1403 }
1404 return nullptr;
1405 }
1406
1407 JavaThread* Threads::owning_thread_from_monitor(ThreadsList* t_list, ObjectMonitor* monitor) {
1408 if (monitor->has_anonymous_owner()) {
1409 if (LockingMode == LM_LIGHTWEIGHT) {
1410 return owning_thread_from_object(t_list, monitor->object());
1411 } else {
1412 assert(LockingMode == LM_LEGACY, "invariant");
1413 return owning_thread_from_stacklock(t_list, (address)monitor->stack_locker());
1414 }
1415 } else {
1416 JavaThread* the_owner = nullptr;
1417 for (JavaThread* q : *t_list) {
1418 if (monitor->has_owner(q)) {
1419 the_owner = q;
1420 break;
1421 }
1422 }
1423 return the_owner;
1424 }
1425 }
1426
1427 class PrintOnClosure : public ThreadClosure {
1428 private:
1429 outputStream* _st;
1430
1431 public:
1432 PrintOnClosure(outputStream* st) :
1433 _st(st) {}
1434
1435 virtual void do_thread(Thread* thread) {
1436 if (thread != nullptr) {
1437 thread->print_on(_st);
1438 _st->cr();
1439 }
1440 }
1441 };
1442
1443 // Threads::print_on() is called at safepoint by VM_PrintThreads operation.
1444 void Threads::print_on(outputStream* st, bool print_stacks,
1445 bool internal_format, bool print_concurrent_locks,
1446 bool print_extended_info) {
1447 char buf[32];
1448 st->print_raw_cr(os::local_time_string(buf, sizeof(buf)));
1449
1450 st->print_cr("Full thread dump %s (%s %s):",
1451 VM_Version::vm_name(),
1452 VM_Version::vm_release(),
1453 VM_Version::vm_info_string());
1454 st->cr();
1455
1456 #if INCLUDE_SERVICES
1457 // Dump concurrent locks
1458 ConcurrentLocksDump concurrent_locks;
1459 if (print_concurrent_locks) {
1460 concurrent_locks.dump_at_safepoint();
1461 }
1462 #endif // INCLUDE_SERVICES
1463
1464 ThreadsSMRSupport::print_info_on(st);
1465 st->cr();
1466
1467 ALL_JAVA_THREADS(p) {
1468 ResourceMark rm;
1469 p->print_on(st, print_extended_info);
1470 if (print_stacks) {
1471 if (internal_format) {
1472 p->trace_stack();
1473 } else {
1474 p->print_stack_on(st);
1475 if (p->is_vthread_mounted()) {
1476 st->print_cr(" Mounted virtual thread #" INT64_FORMAT, java_lang_Thread::thread_id(p->vthread()));
1477 p->print_vthread_stack_on(st);
1478 }
1479 }
1480 }
1481 st->cr();
1482 #if INCLUDE_SERVICES
1483 if (print_concurrent_locks) {
1484 concurrent_locks.print_locks_on(p, st);
1485 }
1486 #endif // INCLUDE_SERVICES
1487 }
1488
1489 PrintOnClosure cl(st);
1490 non_java_threads_do(&cl);
1491
1492 st->flush();
1493 }
1494
1495 void Threads::print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
1496 int buflen, bool* found_current) {
1497 if (this_thread != nullptr) {
1498 bool is_current = (current == this_thread);
1499 *found_current = *found_current || is_current;
1500 st->print("%s", is_current ? "=>" : " ");
1501
1502 st->print(PTR_FORMAT, p2i(this_thread));
1503 st->print(" ");
1504 this_thread->print_on_error(st, buf, buflen);
1505 st->cr();
1506 }
1507 }
1508
1509 class PrintOnErrorClosure : public ThreadClosure {
1510 outputStream* _st;
1511 Thread* _current;
1512 char* _buf;
1513 int _buflen;
1514 bool* _found_current;
1515 unsigned _num_printed;
1516 public:
1517 PrintOnErrorClosure(outputStream* st, Thread* current, char* buf,
1518 int buflen, bool* found_current) :
1519 _st(st), _current(current), _buf(buf), _buflen(buflen), _found_current(found_current),
1520 _num_printed(0) {}
1521
1522 virtual void do_thread(Thread* thread) {
1523 _num_printed++;
1524 Threads::print_on_error(thread, _st, _current, _buf, _buflen, _found_current);
1525 }
1526
1527 unsigned num_printed() const { return _num_printed; }
1528 };
1529
1530 // Threads::print_on_error() is called by fatal error handler. It's possible
1531 // that VM is not at safepoint and/or current thread is inside signal handler.
1532 // Don't print stack trace, as the stack may not be walkable. Don't allocate
1533 // memory (even in resource area), it might deadlock the error handler.
1534 void Threads::print_on_error(outputStream* st, Thread* current, char* buf,
1535 int buflen) {
1536 ThreadsSMRSupport::print_info_on(st);
1537 st->cr();
1538
1539 bool found_current = false;
1540 st->print_cr("Java Threads: ( => current thread )");
1541 unsigned num_java = 0;
1542 ALL_JAVA_THREADS(thread) {
1543 print_on_error(thread, st, current, buf, buflen, &found_current);
1544 num_java++;
1545 }
1546 st->print_cr("Total: %u", num_java);
1547 st->cr();
1548
1549 st->print_cr("Other Threads:");
1550 unsigned num_other = ((VMThread::vm_thread() != nullptr) ? 1 : 0) +
1551 ((WatcherThread::watcher_thread() != nullptr) ? 1 : 0) +
1552 ((AsyncLogWriter::instance() != nullptr) ? 1 : 0);
1553 print_on_error(VMThread::vm_thread(), st, current, buf, buflen, &found_current);
1554 print_on_error(WatcherThread::watcher_thread(), st, current, buf, buflen, &found_current);
1555 print_on_error(AsyncLogWriter::instance(), st, current, buf, buflen, &found_current);
1556
1557 if (Universe::heap() != nullptr) {
1558 PrintOnErrorClosure print_closure(st, current, buf, buflen, &found_current);
1559 Universe::heap()->gc_threads_do(&print_closure);
1560 num_other += print_closure.num_printed();
1561 }
1562
1563 if (!found_current) {
1564 st->cr();
1565 st->print("=>" PTR_FORMAT " (exited) ", p2i(current));
1566 current->print_on_error(st, buf, buflen);
1567 num_other++;
1568 st->cr();
1569 }
1570 st->print_cr("Total: %u", num_other);
1571 st->cr();
1572
1573 st->print_cr("Threads with active compile tasks:");
1574 unsigned num = print_threads_compiling(st, buf, buflen);
1575 st->print_cr("Total: %u", num);
1576 }
1577
1578 unsigned Threads::print_threads_compiling(outputStream* st, char* buf, int buflen, bool short_form) {
1579 unsigned num = 0;
1580 ALL_JAVA_THREADS(thread) {
1581 if (thread->is_Compiler_thread()) {
1582 CompilerThread* ct = (CompilerThread*) thread;
1583
1584 // Keep task in local variable for null check.
1585 // ct->_task might be set to null by concurring compiler thread
1586 // because it completed the compilation. The task is never freed,
1587 // though, just returned to a free list.
1588 CompileTask* task = ct->task();
1589 if (task != nullptr) {
1590 thread->print_name_on_error(st, buf, buflen);
1591 st->print(" ");
1592 task->print(st, nullptr, short_form, true);
1593 num++;
1594 }
1595 }
1596 }
1597 return num;
1598 }
1599
1600 void Threads::verify() {
1601 ALL_JAVA_THREADS(p) {
1602 p->verify();
1603 }
1604 VMThread* thread = VMThread::vm_thread();
1605 if (thread != nullptr) thread->verify();
1606 }