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/aotMetaspace.hpp"
29 #include "cds/cds_globals.hpp"
30 #include "cds/cdsConfig.hpp"
31 #include "cds/heapShared.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/compilerThread.hpp"
45 #include "compiler/compileTask.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/threads.hpp"
101 #include "runtime/threadSMR.inline.hpp"
102 #include "runtime/timer.hpp"
103 #include "runtime/timerTrace.hpp"
104 #include "runtime/trimNativeHeap.hpp"
105 #include "runtime/vm_version.hpp"
106 #include "runtime/vmOperations.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
341 // Phase 3. final setup - set security manager, system class loader and TCCL
342 //
343 // This will instantiate and set the security manager, set the system class
344 // loader as well as the thread context class loader. The security manager
345 // and system class loader may be a custom class loaded from -Xbootclasspath/a,
346 // other modules or the application's classpath.
347 static void call_initPhase3(TRAPS) {
348 Klass* klass = vmClasses::System_klass();
349 JavaValue result(T_VOID);
350 JavaCalls::call_static(&result, klass, vmSymbols::initPhase3_name(),
351 vmSymbols::void_method_signature(), CHECK);
352 }
353
354 void Threads::initialize_java_lang_classes(JavaThread* main_thread, TRAPS) {
355 TraceTime timer("Initialize java.lang classes", TRACETIME_LOG(Info, startuptime));
356
357 initialize_class(vmSymbols::java_lang_String(), CHECK);
358
359 // Inject CompactStrings value after the static initializers for String ran.
360 java_lang_String::set_compact_strings(CompactStrings);
361
362 // Initialize java_lang.System (needed before creating the thread)
363 initialize_class(vmSymbols::java_lang_System(), CHECK);
364 // The VM creates & returns objects of this class. Make sure it's initialized.
365 initialize_class(vmSymbols::java_lang_Class(), CHECK);
366
367 initialize_class(vmSymbols::java_lang_ThreadGroup(), CHECK);
368 Handle thread_group = create_initial_thread_group(CHECK);
369 Universe::set_main_thread_group(thread_group());
370 initialize_class(vmSymbols::java_lang_Thread(), CHECK);
371 create_initial_thread(thread_group, main_thread, CHECK);
372
373 HeapShared::init_box_classes(CHECK);
374
375 // The VM creates objects of this class.
376 initialize_class(vmSymbols::java_lang_Module(), CHECK);
377
378 #ifdef ASSERT
379 InstanceKlass *k = vmClasses::UnsafeConstants_klass();
380 assert(k->is_not_initialized(), "UnsafeConstants should not already be initialized");
381 #endif
382
383 // initialize the hardware-specific constants needed by Unsafe
384 initialize_class(vmSymbols::jdk_internal_misc_UnsafeConstants(), CHECK);
385 jdk_internal_misc_UnsafeConstants::set_unsafe_constants();
386
387 // The VM preresolves methods to these classes. Make sure that they get initialized
388 initialize_class(vmSymbols::java_lang_reflect_Method(), CHECK);
389 initialize_class(vmSymbols::java_lang_ref_Finalizer(), CHECK);
390
391 if (CDSConfig::is_using_aot_linked_classes()) {
392 // This is necessary for reflection to work in early core lib bootstrap code.
393 vmClasses::reflect_AccessibleObject_klass()->link_class(CHECK);
394 vmClasses::reflect_Field_klass()->link_class(CHECK);
395 vmClasses::reflect_Parameter_klass()->link_class(CHECK);
396 vmClasses::reflect_Method_klass()->link_class(CHECK);
397 vmClasses::reflect_Constructor_klass()->link_class(CHECK);
398 }
399
400 // Phase 1 of the system initialization in the library, java.lang.System class initialization
401 call_initPhase1(CHECK);
402
403 // Get the Java runtime name, version, and vendor info after java.lang.System is initialized.
404 // Some values are actually configure-time constants but some can be set via the jlink tool and
405 // so must be read dynamically. We treat them all the same.
406 InstanceKlass* ik = SystemDictionary::find_instance_klass(THREAD, vmSymbols::java_lang_VersionProps(),
407 Handle());
408 {
409 ResourceMark rm(main_thread);
410 JDK_Version::set_java_version(get_java_version_info(ik, vmSymbols::java_version_name()));
411
412 JDK_Version::set_runtime_name(get_java_version_info(ik, vmSymbols::java_runtime_name_name()));
413
414 JDK_Version::set_runtime_version(get_java_version_info(ik, vmSymbols::java_runtime_version_name()));
415
416 JDK_Version::set_runtime_vendor_version(get_java_version_info(ik, vmSymbols::java_runtime_vendor_version_name()));
417
418 JDK_Version::set_runtime_vendor_vm_bug_url(get_java_version_info(ik, vmSymbols::java_runtime_vendor_vm_bug_url_name()));
419 }
420
421 // an instance of OutOfMemory exception has been allocated earlier
422 initialize_class(vmSymbols::java_lang_OutOfMemoryError(), CHECK);
423 initialize_class(vmSymbols::java_lang_NullPointerException(), CHECK);
424 initialize_class(vmSymbols::java_lang_ClassCastException(), CHECK);
425 initialize_class(vmSymbols::java_lang_ArrayStoreException(), CHECK);
426 initialize_class(vmSymbols::java_lang_ArithmeticException(), CHECK);
427 initialize_class(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), CHECK);
428 initialize_class(vmSymbols::java_lang_StackOverflowError(), CHECK);
429 initialize_class(vmSymbols::java_lang_IllegalMonitorStateException(), CHECK);
430 initialize_class(vmSymbols::java_lang_IllegalArgumentException(), CHECK);
431 initialize_class(vmSymbols::java_lang_InternalError(), CHECK);
432 }
433
434 bool Threads::initialize_compilation(TRAPS) {
435 // initialize compiler(s)
436 bool force_JVMCI_initialization = false;
437
438 #if defined(COMPILER1) || COMPILER2_OR_JVMCI
439 bool init_compilation = true;
440 #if INCLUDE_JVMCI
441 if (EnableJVMCI) {
442 // Initialize JVMCI eagerly when it is explicitly requested.
443 // Or when JVMCILibDumpJNIConfig or JVMCIPrintProperties is enabled.
444 force_JVMCI_initialization = EagerJVMCI || JVMCIPrintProperties || JVMCILibDumpJNIConfig;
445 if (!force_JVMCI_initialization && UseJVMCICompiler && !UseJVMCINativeLibrary && (!UseInterpreter || !BackgroundCompilation)) {
446 // Force initialization of jarjvmci otherwise requests for blocking
447 // compilations will not actually block until jarjvmci is initialized.
448 force_JVMCI_initialization = true;
449 }
450 if (JVMCIPrintProperties || JVMCILibDumpJNIConfig) {
451 // Both JVMCILibDumpJNIConfig and JVMCIPrintProperties exit the VM
452 // so compilation should be disabled. This prevents dumping or
453 // printing from happening more than once.
454 init_compilation = false;
455 }
456 }
457 #endif
458 if (init_compilation) {
459 CompileBroker::compilation_init(CHECK_false);
460 }
461 #endif
462
463 return force_JVMCI_initialization;
464 }
465
466 void Threads::initialize_jsr292_core_classes(TRAPS) {
467 TraceTime timer("Initialize java.lang.invoke classes", TRACETIME_LOG(Info, startuptime));
468
469 initialize_class(vmSymbols::java_lang_invoke_MethodHandle(), CHECK);
470 initialize_class(vmSymbols::java_lang_invoke_ResolvedMethodName(), CHECK);
471 initialize_class(vmSymbols::java_lang_invoke_MemberName(), CHECK);
472 initialize_class(vmSymbols::java_lang_invoke_MethodHandleNatives(), CHECK);
473
474 if (UseSharedSpaces) {
475 HeapShared::initialize_java_lang_invoke(CHECK);
476 }
477 }
478
479 // One-shot PeriodicTask subclass for reading the release file
480 class ReadReleaseFileTask : public PeriodicTask {
481 public:
482 ReadReleaseFileTask() : PeriodicTask(100) {}
483
484 virtual void task() {
485 os::read_image_release_file();
486
487 // Reclaim our storage and disenroll ourself.
488 delete this;
489 }
490 };
491
492 jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) {
493 extern void JDK_Version_init();
494
495 // Preinitialize version info.
496 VM_Version::early_initialize();
497
498 // Check version
499 if (!is_supported_jni_version(args->version)) return JNI_EVERSION;
500
501 // Initialize library-based TLS
502 ThreadLocalStorage::init();
503
504 // Initialize the output stream module
505 ostream_init();
506
507 // Process java launcher properties.
508 Arguments::process_sun_java_launcher_properties(args);
509
510 // Initialize the os module
511 os::init();
512
513 // Initialize memory pools
514 Arena::initialize_chunk_pool();
515
516 MACOS_AARCH64_ONLY(os::current_thread_enable_wx(WXWrite));
517
518 // Record VM creation timing statistics
519 TraceVmCreationTime create_vm_timer;
520 create_vm_timer.start();
521
522 // Initialize system properties.
523 Arguments::init_system_properties();
524
525 // So that JDK version can be used as a discriminator when parsing arguments
526 JDK_Version_init();
527
528 // Update/Initialize System properties after JDK version number is known
529 Arguments::init_version_specific_system_properties();
530
531 // Make sure to initialize log configuration *before* parsing arguments
532 LogConfiguration::initialize(create_vm_timer.begin_time());
533
534 // Parse arguments
535 // Note: this internally calls os::init_container_support()
536 jint parse_result = Arguments::parse(args);
537 if (parse_result != JNI_OK) return parse_result;
538
539 // Initialize NMT right after argument parsing to keep the pre-NMT-init window small.
540 MemTracker::initialize();
541
542 os::init_before_ergo();
543
544 jint ergo_result = Arguments::apply_ergo();
545 if (ergo_result != JNI_OK) return ergo_result;
546
547 // Final check of all ranges after ergonomics which may change values.
548 if (!JVMFlagLimit::check_all_ranges()) {
549 return JNI_EINVAL;
550 }
551
552 // Final check of all 'AfterErgo' constraints after ergonomics which may change values.
553 bool constraint_result = JVMFlagLimit::check_all_constraints(JVMFlagConstraintPhase::AfterErgo);
554 if (!constraint_result) {
555 return JNI_EINVAL;
556 }
557
558 if (PauseAtStartup) {
559 os::pause();
560 }
561
562 HOTSPOT_VM_INIT_BEGIN();
563
564 // Timing (must come after argument parsing)
565 TraceTime timer("Create VM", TRACETIME_LOG(Info, startuptime));
566
567 // Initialize the os module after parsing the args
568 jint os_init_2_result = os::init_2();
569 if (os_init_2_result != JNI_OK) return os_init_2_result;
570
571 #ifdef CAN_SHOW_REGISTERS_ON_ASSERT
572 // Initialize assert poison page mechanism.
573 if (ShowRegistersOnAssert) {
574 initialize_assert_poison();
575 }
576 #endif // CAN_SHOW_REGISTERS_ON_ASSERT
577
578 SafepointMechanism::initialize();
579
580 jint adjust_after_os_result = Arguments::adjust_after_os();
581 if (adjust_after_os_result != JNI_OK) return adjust_after_os_result;
582
583 // Initialize output stream logging
584 ostream_init_log();
585
586 // Launch -agentlib/-agentpath and converted -Xrun agents
587 JvmtiAgentList::load_agents();
588
589 // Initialize Threads state
590 _number_of_threads = 0;
591 _number_of_non_daemon_threads = 0;
592
593 // Initialize global data structures and create system classes in heap
594 vm_init_globals();
595
596 #if INCLUDE_JVMCI
597 if (JVMCICounterSize > 0) {
598 JavaThread::_jvmci_old_thread_counters = NEW_C_HEAP_ARRAY(jlong, JVMCICounterSize, mtJVMCI);
599 memset(JavaThread::_jvmci_old_thread_counters, 0, sizeof(jlong) * JVMCICounterSize);
600 } else {
601 JavaThread::_jvmci_old_thread_counters = nullptr;
602 }
603 #endif // INCLUDE_JVMCI
604
605 // Initialize OopStorage for threadObj
606 JavaThread::_thread_oop_storage = OopStorageSet::create_strong("Thread OopStorage", mtThread);
607
608 // Attach the main thread to this os thread
609 JavaThread* main_thread = new JavaThread();
610 main_thread->set_thread_state(_thread_in_vm);
611 main_thread->initialize_thread_current();
612 // Once mutexes and main_thread are ready, we can use NmtVirtualMemoryLocker.
613 MemTracker::NmtVirtualMemoryLocker::set_safe_to_use();
614 // must do this before set_active_handles
615 main_thread->record_stack_base_and_size();
616 main_thread->register_thread_stack_with_NMT();
617 main_thread->set_active_handles(JNIHandleBlock::allocate_block());
618 MACOS_AARCH64_ONLY(main_thread->init_wx());
619
620 MutexLockerImpl::init_counters(); // depends on mutex_init(), perfMemory_init(), and Thread::initialize_thread_current().
621
622 // Set the _monitor_owner_id now since we will run Java code before the Thread instance
623 // is even created. The same value will be assigned to the Thread instance on init.
624 main_thread->set_monitor_owner_id(ThreadIdentifier::next());
625
626 if (!Thread::set_as_starting_thread(main_thread)) {
627 vm_shutdown_during_initialization(
628 "Failed necessary internal allocation. Out of swap space");
629 main_thread->smr_delete();
630 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
631 return JNI_ENOMEM;
632 }
633
634 JFR_ONLY(Jfr::initialize_main_thread(main_thread);)
635
636 // Enable guard page *after* os::create_main_thread(), otherwise it would
637 // crash Linux VM, see notes in os_linux.cpp.
638 main_thread->stack_overflow_state()->create_stack_guard_pages();
639
640 // Initialize Java-Level synchronization subsystem
641 ObjectMonitor::Initialize();
642 ObjectSynchronizer::initialize();
643
644 Deoptimization::init_counters();
645 VMThread::init_counters();
646
647 // Initialize global modules
648 jint status = init_globals();
649 if (status != JNI_OK) {
650 main_thread->smr_delete();
651 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
652 return status;
653 }
654 if (xtty != nullptr)
655 xtty->elem("vm_main_thread thread='%zu'",
656 (uintx) main_thread->osthread()->thread_id());
657
658 // Have the WatcherThread read the release file in the background.
659 ReadReleaseFileTask* read_task = new ReadReleaseFileTask();
660 read_task->enroll();
661
662 // Create WatcherThread as soon as we can since we need it in case
663 // of hangs during error reporting.
664 WatcherThread::start();
665
666 // Add main_thread to threads list to finish barrier setup with
667 // on_thread_attach. Should be before starting to build Java objects in
668 // init_globals2, which invokes barriers.
669 {
670 MutexLocker mu(Threads_lock);
671 Threads::add(main_thread);
672 }
673
674 status = init_globals2();
675 if (status != JNI_OK) {
676 Threads::remove(main_thread, false);
677 // It is possible that we managed to fully initialize Universe but have then
678 // failed by throwing an exception. In that case our caller JNI_CreateJavaVM
679 // will want to report it, so we can't delete the main thread.
680 if (!main_thread->has_pending_exception()) {
681 main_thread->smr_delete();
682 }
683 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
684 return status;
685 }
686
687 ObjectMonitor::Initialize2();
688
689 JFR_ONLY(Jfr::on_create_vm_1();)
690
691 // Should be done after the heap is fully created
692 main_thread->cache_global_variables();
693
694 // Any JVMTI raw monitors entered in onload will transition into
695 // real raw monitor. VM is setup enough here for raw monitor enter.
696 JvmtiExport::transition_pending_onload_raw_monitors();
697
698 // Create the VMThread
699 { TraceTime timer("Start VMThread", TRACETIME_LOG(Info, startuptime));
700
701 VMThread::create();
702 VMThread* vmthread = VMThread::vm_thread();
703
704 if (!os::create_thread(vmthread, os::vm_thread)) {
705 vm_exit_during_initialization("Cannot create VM thread. "
706 "Out of system resources.");
707 }
708
709 // Wait for the VM thread to become ready, and VMThread::run to initialize
710 // Monitors can have spurious returns, must always check another state flag
711 {
712 MonitorLocker ml(Notify_lock);
713 os::start_thread(vmthread);
714 while (!vmthread->is_running()) {
715 ml.wait();
716 }
717 }
718 }
719
720 assert(Universe::is_fully_initialized(), "not initialized");
721 if (VerifyDuringStartup) {
722 // Make sure we're starting with a clean slate.
723 VM_Verify verify_op;
724 VMThread::execute(&verify_op);
725 }
726
727 // We need this to update the java.vm.info property in case any flags used
728 // to initially define it have been changed. This is needed for both CDS
729 // since UseSharedSpaces may be changed after java.vm.info
730 // is initially computed. See Abstract_VM_Version::vm_info_string().
731 // This update must happen before we initialize the java classes, but
732 // after any initialization logic that might modify the flags.
733 Arguments::update_vm_info_property(VM_Version::vm_info_string());
734
735 JavaThread* THREAD = JavaThread::current(); // For exception macros.
736 HandleMark hm(THREAD);
737
738 // Always call even when there are not JVMTI environments yet, since environments
739 // may be attached late and JVMTI must track phases of VM execution
740 JvmtiExport::enter_early_start_phase();
741
742 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
743 JvmtiExport::post_early_vm_start();
744
745 // Launch -Xrun agents early if EagerXrunInit is set
746 if (EagerXrunInit) {
747 JvmtiAgentList::load_xrun_agents();
748 }
749
750 initialize_java_lang_classes(main_thread, CHECK_JNI_ERR);
751
752 quicken_jni_functions();
753
754 // No more stub generation allowed after that point.
755 StubCodeDesc::freeze();
756
757 // Set flag that basic initialization has completed. Used by exceptions and various
758 // debug stuff, that does not work until all basic classes have been initialized.
759 set_init_completed();
760
761 LogConfiguration::post_initialize();
762 Metaspace::post_initialize();
763 MutexLockerImpl::post_initialize();
764
765 HOTSPOT_VM_INIT_END();
766
767 // record VM initialization completion time
768 #if INCLUDE_MANAGEMENT
769 Management::record_vm_init_completed();
770 #endif // INCLUDE_MANAGEMENT
771
772 log_info(os)("Initialized VM with process ID %d", os::current_process_id());
773
774 if (!FLAG_IS_DEFAULT(CreateCoredumpOnCrash) && CreateCoredumpOnCrash) {
775 char buffer[2*JVM_MAXPATHLEN];
776 os::check_core_dump_prerequisites(buffer, sizeof(buffer), true);
777 }
778
779 // Signal Dispatcher needs to be started before VMInit event is posted
780 os::initialize_jdk_signal_support(CHECK_JNI_ERR);
781
782 // Start Attach Listener if +StartAttachListener or it can't be started lazily
783 if (!DisableAttachMechanism) {
784 AttachListener::vm_start();
785 if (StartAttachListener || AttachListener::init_at_startup()) {
786 AttachListener::init();
787 }
788 }
789
790 // Launch -Xrun agents if EagerXrunInit is not set.
791 if (!EagerXrunInit) {
792 JvmtiAgentList::load_xrun_agents();
793 }
794
795 Arena::start_chunk_pool_cleaner_task();
796
797 // Start the service thread
798 // The service thread enqueues JVMTI deferred events and does various hashtable
799 // and other cleanups. Needs to start before the compilers start posting events.
800 ServiceThread::initialize();
801
802 // Start the monitor deflation thread:
803 MonitorDeflationThread::initialize();
804
805 #if INCLUDE_CDS
806 // Start the method sampler
807 MethodProfiler::initialize();
808 #endif
809
810 bool force_JVMCI_initialization = initialize_compilation(CHECK_JNI_ERR);
811
812 if (CDSConfig::is_using_aot_linked_classes()) {
813 SystemDictionary::restore_archived_method_handle_intrinsics();
814 AOTLinkedClassBulkLoader::finish_loading_javabase_classes(CHECK_JNI_ERR);
815 }
816
817 // Start string deduplication thread if requested.
818 if (StringDedup::is_enabled()) {
819 StringDedup::start();
820 }
821
822 // Pre-initialize some JSR292 core classes to avoid deadlock during class loading.
823 // It is done after compilers are initialized, because otherwise compilations of
824 // signature polymorphic MH intrinsics can be missed
825 // (see SystemDictionary::find_method_handle_intrinsic).
826 initialize_jsr292_core_classes(CHECK_JNI_ERR);
827
828 // This will initialize the module system. Only java.base classes can be
829 // loaded until phase 2 completes
830 call_initPhase2(CHECK_JNI_ERR);
831
832 if (CDSConfig::is_using_aot_linked_classes() && !CDSConfig::is_dumping_final_static_archive()) {
833 AOTLinkedClassBulkLoader::load_non_javabase_classes(THREAD);
834 }
835 #ifndef PRODUCT
836 HeapShared::initialize_test_class_from_archive(THREAD);
837 #endif
838
839 JFR_ONLY(Jfr::on_create_vm_2();)
840
841 // Always call even when there are not JVMTI environments yet, since environments
842 // may be attached late and JVMTI must track phases of VM execution
843 JvmtiExport::enter_start_phase();
844
845 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
846 JvmtiExport::post_vm_start();
847
848 // Final system initialization including security manager and system class loader
849 call_initPhase3(CHECK_JNI_ERR);
850
851 // cache the system and platform class loaders
852 SystemDictionary::compute_java_loaders(CHECK_JNI_ERR);
853
854 // Initiate replay training processing once preloading is over.
855 CompileBroker::init_training_replay();
856
857 AOTLinkedClassBulkLoader::replay_training_at_init_for_preloaded_classes(CHECK_JNI_ERR);
858
859 if (Continuations::enabled()) {
860 // Initialize Continuation class now so that failure to create enterSpecial/doYield
861 // special nmethods due to limited CodeCache size can be treated as a fatal error at
862 // startup with the proper message that CodeCache size is too small.
863 initialize_class(vmSymbols::jdk_internal_vm_Continuation(), CHECK_JNI_ERR);
864 }
865
866 #if INCLUDE_CDS
867 if (PrecompileCode) {
868 Precompiler::compile_aot_code(CHECK_JNI_ERR);
869 if (PrecompileOnlyAndExit) {
870 AOTCodeCache::close();
871 log_vm_init_stats();
872 vm_direct_exit(0, "Code precompiation is over");
873 }
874 }
875 #endif
876
877 #if defined(COMPILER2)
878 // Pre-load cached compiled methods
879 AOTCodeCache::preload_code(CHECK_JNI_ERR);
880 #endif
881
882 if (NativeHeapTrimmer::enabled()) {
883 NativeHeapTrimmer::initialize();
884 }
885
886 // Always call even when there are not JVMTI environments yet, since environments
887 // may be attached late and JVMTI must track phases of VM execution
888 JvmtiExport::enter_live_phase();
889
890 // Make perfmemory accessible
891 PerfMemory::set_accessible(true);
892
893 // Notify JVMTI agents that VM initialization is complete - nop if no agents.
894 JvmtiExport::post_vm_initialized();
895
896 #if INCLUDE_JVMCI
897 if (force_JVMCI_initialization) {
898 JVMCI::initialize_compiler_in_create_vm(CHECK_JNI_ERR);
899 }
900 #endif
901
902 JFR_ONLY(Jfr::on_create_vm_3();)
903
904 #if INCLUDE_MANAGEMENT
905 bool start_agent = true;
906 #if INCLUDE_CDS
907 start_agent = !CDSConfig::is_dumping_final_static_archive();
908 if (!start_agent) {
909 log_info(aot)("Not starting management agent during creation of AOT cache.");
910 }
911 #endif // INCLUDE_CDS
912 if (start_agent) {
913 Management::initialize(THREAD);
914
915 if (HAS_PENDING_EXCEPTION) {
916 // management agent fails to start possibly due to
917 // configuration problem and is responsible for printing
918 // stack trace if appropriate. Simply exit VM.
919 vm_exit(1);
920 }
921 }
922 #endif // INCLUDE_MANAGEMENT
923
924 if (UsePerfData) PerfDataManager::create_misc_perfdata();
925 if (CheckJNICalls) JniPeriodicChecker::engage();
926
927 call_postVMInitHook(THREAD);
928 // The Java side of PostVMInitHook.run must deal with all
929 // exceptions and provide means of diagnosis.
930 if (HAS_PENDING_EXCEPTION) {
931 CLEAR_PENDING_EXCEPTION;
932 }
933
934 // Let WatcherThread run all registered periodic tasks now.
935 // NOTE: All PeriodicTasks should be registered by now. If they
936 // aren't, late joiners might appear to start slowly (we might
937 // take a while to process their first tick).
938 WatcherThread::run_all_tasks();
939
940 create_vm_timer.end();
941 #ifdef ASSERT
942 _vm_complete = true;
943 #endif
944
945 if (CDSConfig::is_dumping_classic_static_archive()) {
946 // Classic -Xshare:dump, aka "old workflow"
947 AOTMetaspace::preload_and_dump(CHECK_JNI_ERR);
948 } else if (CDSConfig::is_dumping_final_static_archive()) {
949 tty->print_cr("Reading AOTConfiguration %s and writing AOTCache %s", AOTConfiguration, AOTCache);
950 AOTMetaspace::preload_and_dump(CHECK_JNI_ERR);
951 }
952
953 log_info(init)("At VM initialization completion:");
954 log_vm_init_stats();
955
956 if (UsePerfData) {
957 if (ProfileVMLocks) {
958 main_thread->set_profile_vm_locks(true);
959 }
960 if (ProfileVMCalls) {
961 main_thread->set_profile_vm_calls(true);
962 }
963 if (ProfileRuntimeCalls) {
964 main_thread->set_profile_rt_calls(true);
965 }
966 if (ProfileVMOps) {
967 main_thread->set_profile_vm_ops(true);
968 }
969 }
970
971 return JNI_OK;
972 }
973
974 // Threads::destroy_vm() is normally called from jni_DestroyJavaVM() when
975 // the program falls off the end of main(). Another VM exit path is through
976 // vm_exit(), when the program calls System.exit() to return a value, or when
977 // there is a serious error in VM.
978 // These two separate shutdown paths are not exactly the same, but they share
979 // Shutdown.shutdown() at Java level and before_exit() and VM_Exit op at VM level.
980 //
981 // Shutdown sequence:
982 // + Shutdown native memory tracking if it is on
983 // + Wait until we are the last non-daemon thread to execute
984 // <-- every thing is still working at this moment -->
985 // + Call java.lang.Shutdown.shutdown(), which will invoke Java level
986 // shutdown hooks
987 // + Call before_exit(), prepare for VM exit
988 // > run VM level shutdown hooks (they are registered through JVM_OnExit(),
989 // currently the only user of this mechanism is File.deleteOnExit())
990 // > stop watcher thread,
991 // post thread end and vm death events to JVMTI,
992 // stop signal thread
993 // + Call JavaThread::exit(), it will:
994 // > release JNI handle blocks, remove stack guard pages
995 // > remove this thread from Threads list
996 // <-- no more Java code from this thread after this point -->
997 // + Stop VM thread, it will bring the remaining VM to a safepoint and stop
998 // the compiler threads at safepoint
999 // <-- do not use anything that could get blocked by Safepoint -->
1000 // + Disable tracing at JNI/JVM barriers
1001 // + Set _vm_exited flag for threads that are still running native code
1002 // + Call exit_globals()
1003 // > deletes tty
1004 // > deletes PerfMemory resources
1005 // + Delete this thread
1006 // + Return to caller
1007
1008 void Threads::destroy_vm() {
1009 JavaThread* thread = JavaThread::current();
1010
1011 #ifdef ASSERT
1012 _vm_complete = false;
1013 #endif
1014 // Wait until we are the last non-daemon thread to execute, or
1015 // if we are a daemon then wait until the last non-daemon thread has
1016 // executed.
1017 bool daemon = java_lang_Thread::is_daemon(thread->threadObj());
1018 int expected = daemon ? 0 : 1;
1019 {
1020 MonitorLocker nu(Threads_lock);
1021 while (Threads::number_of_non_daemon_threads() > expected)
1022 // This wait should make safepoint checks, wait without a timeout.
1023 nu.wait(0);
1024 }
1025
1026 EventShutdown e;
1027 if (e.should_commit()) {
1028 e.set_reason("No remaining non-daemon Java threads");
1029 e.commit();
1030 }
1031
1032 // Hang forever on exit if we are reporting an error.
1033 if (ShowMessageBoxOnError && VMError::is_error_reported()) {
1034 os::infinite_sleep();
1035 }
1036 os::wait_for_keypress_at_exit();
1037
1038 // run Java level shutdown hooks
1039 thread->invoke_shutdown_hooks();
1040
1041 before_exit(thread);
1042
1043 thread->exit(true);
1044
1045 // We are no longer on the main thread list but could still be in a
1046 // secondary list where another thread may try to interact with us.
1047 // So wait until all such interactions are complete before we bring
1048 // the VM to the termination safepoint. Normally this would be done
1049 // using thread->smr_delete() below where we delete the thread, but
1050 // we can't call that after the termination safepoint is active as
1051 // we will deadlock on the Threads_lock. Once all interactions are
1052 // complete it is safe to directly delete the thread at any time.
1053 ThreadsSMRSupport::wait_until_not_protected(thread);
1054
1055 // Stop VM thread.
1056 {
1057 // 4945125 The vm thread comes to a safepoint during exit.
1058 // GC vm_operations can get caught at the safepoint, and the
1059 // heap is unparseable if they are caught. Grab the Heap_lock
1060 // to prevent this. The GC vm_operations will not be able to
1061 // queue until after the vm thread is dead. After this point,
1062 // we'll never emerge out of the safepoint before the VM exits.
1063 // Assert that the thread is terminated so that acquiring the
1064 // Heap_lock doesn't cause the terminated thread to participate in
1065 // the safepoint protocol.
1066
1067 assert(thread->is_terminated(), "must be terminated here");
1068 MutexLocker ml(Heap_lock);
1069
1070 VMThread::wait_for_vm_thread_exit();
1071 assert(SafepointSynchronize::is_at_safepoint(), "VM thread should exit at Safepoint");
1072 VMThread::destroy();
1073 }
1074
1075 // Now, all Java threads are gone except daemon threads. Daemon threads
1076 // running Java code or in VM are stopped by the Safepoint. However,
1077 // daemon threads executing native code are still running. But they
1078 // will be stopped at native=>Java/VM barriers. Note that we can't
1079 // simply kill or suspend them, as it is inherently deadlock-prone.
1080
1081 #if INCLUDE_CDS
1082 if (AOTVerifyTrainingData) {
1083 TrainingData::verify();
1084 }
1085 #endif
1086
1087 VM_Exit::set_vm_exited();
1088
1089 // Clean up ideal graph printers after the VMThread has started
1090 // the final safepoint which will block all the Compiler threads.
1091 // Note that this Thread has already logically exited so the
1092 // clean_up() function's use of a JavaThreadIteratorWithHandle
1093 // would be a problem except set_vm_exited() has remembered the
1094 // shutdown thread which is granted a policy exception.
1095 #if defined(COMPILER2) && !defined(PRODUCT)
1096 IdealGraphPrinter::clean_up();
1097 #endif
1098
1099 notify_vm_shutdown();
1100
1101 // exit_globals() will delete tty
1102 exit_globals();
1103
1104 // Deleting the shutdown thread here is safe. See comment on
1105 // wait_until_not_protected() above.
1106 delete thread;
1107
1108 #if INCLUDE_JVMCI
1109 if (JVMCICounterSize > 0) {
1110 FREE_C_HEAP_ARRAY(jlong, JavaThread::_jvmci_old_thread_counters);
1111 }
1112 #endif
1113
1114 LogConfiguration::finalize();
1115 }
1116
1117
1118 jboolean Threads::is_supported_jni_version_including_1_1(jint version) {
1119 if (version == JNI_VERSION_1_1) return JNI_TRUE;
1120 return is_supported_jni_version(version);
1121 }
1122
1123
1124 jboolean Threads::is_supported_jni_version(jint version) {
1125 if (version == JNI_VERSION_1_2) return JNI_TRUE;
1126 if (version == JNI_VERSION_1_4) return JNI_TRUE;
1127 if (version == JNI_VERSION_1_6) return JNI_TRUE;
1128 if (version == JNI_VERSION_1_8) return JNI_TRUE;
1129 if (version == JNI_VERSION_9) return JNI_TRUE;
1130 if (version == JNI_VERSION_10) return JNI_TRUE;
1131 if (version == JNI_VERSION_19) return JNI_TRUE;
1132 if (version == JNI_VERSION_20) return JNI_TRUE;
1133 if (version == JNI_VERSION_21) return JNI_TRUE;
1134 if (version == JNI_VERSION_24) return JNI_TRUE;
1135 return JNI_FALSE;
1136 }
1137
1138 void Threads::add(JavaThread* p, bool force_daemon) {
1139 // The threads lock must be owned at this point
1140 assert(Threads_lock->owned_by_self(), "must have threads lock");
1141 assert(p->monitor_owner_id() != 0, "should be set");
1142
1143 BarrierSet::barrier_set()->on_thread_attach(p);
1144
1145 // Once a JavaThread is added to the Threads list, smr_delete() has
1146 // to be used to delete it. Otherwise we can just delete it directly.
1147 p->set_on_thread_list();
1148
1149 _number_of_threads++;
1150 oop threadObj = p->threadObj();
1151 bool daemon = true;
1152 // Bootstrapping problem: threadObj can be null for initial
1153 // JavaThread (or for threads attached via JNI)
1154 if (!force_daemon &&
1155 (threadObj == nullptr || !java_lang_Thread::is_daemon(threadObj))) {
1156 _number_of_non_daemon_threads++;
1157 daemon = false;
1158 }
1159
1160 ThreadService::add_thread(p, daemon);
1161
1162 // Maintain fast thread list
1163 ThreadsSMRSupport::add_thread(p);
1164
1165 // Increase the ObjectMonitor ceiling for the new thread.
1166 ObjectSynchronizer::inc_in_use_list_ceiling();
1167
1168 // Possible GC point.
1169 Events::log(Thread::current(), "Thread added: " INTPTR_FORMAT, p2i(p));
1170
1171 // Make new thread known to active EscapeBarrier
1172 EscapeBarrier::thread_added(p);
1173 }
1174
1175 void Threads::remove(JavaThread* p, bool is_daemon) {
1176 // Extra scope needed for Thread_lock, so we can check
1177 // that we do not remove thread without safepoint code notice
1178 {
1179 ConditionalMutexLocker throttle_ml(ThreadsLockThrottle_lock, UseThreadsLockThrottleLock);
1180 MonitorLocker ml(Threads_lock);
1181
1182 if (ThreadIdTable::is_initialized()) {
1183 // This cleanup must be done before the current thread's GC barrier
1184 // is detached since we need to touch the threadObj oop.
1185 jlong tid = SharedRuntime::get_java_tid(p);
1186 ThreadIdTable::remove_thread(tid);
1187 }
1188
1189 // BarrierSet state must be destroyed after the last thread transition
1190 // before the thread terminates. Thread transitions result in calls to
1191 // StackWatermarkSet::on_safepoint(), which performs GC processing,
1192 // requiring the GC state to be alive.
1193 BarrierSet::barrier_set()->on_thread_detach(p);
1194 if (p->is_exiting()) {
1195 // If we got here via JavaThread::exit(), then we remember that the
1196 // thread's GC barrier has been detached. We don't do this when we get
1197 // here from another path, e.g., cleanup_failed_attach_current_thread().
1198 p->set_terminated(JavaThread::_thread_gc_barrier_detached);
1199 }
1200
1201 assert(ThreadsSMRSupport::get_java_thread_list()->includes(p), "p must be present");
1202
1203 // Maintain fast thread list
1204 ThreadsSMRSupport::remove_thread(p);
1205
1206 _number_of_threads--;
1207 if (!is_daemon) {
1208 _number_of_non_daemon_threads--;
1209
1210 // If this is the last non-daemon thread then we need to do
1211 // a notify on the Threads_lock so a thread waiting
1212 // on destroy_vm will wake up. But that thread could be a daemon
1213 // or non-daemon, so we notify for both the 0 and 1 case.
1214 if (number_of_non_daemon_threads() <= 1) {
1215 ml.notify_all();
1216 }
1217 }
1218 ThreadService::remove_thread(p, is_daemon);
1219
1220 // Make sure that safepoint code disregard this thread. This is needed since
1221 // the thread might mess around with locks after this point. This can cause it
1222 // to do callbacks into the safepoint code. However, the safepoint code is not aware
1223 // of this thread since it is removed from the queue.
1224 p->set_terminated(JavaThread::_thread_terminated);
1225
1226 // Notify threads waiting in EscapeBarriers
1227 EscapeBarrier::thread_removed(p);
1228 } // unlock Threads_lock and ThreadsLockThrottle_lock
1229
1230 // Reduce the ObjectMonitor ceiling for the exiting thread.
1231 ObjectSynchronizer::dec_in_use_list_ceiling();
1232
1233 // Since Events::log uses a lock, we grab it outside the Threads_lock
1234 Events::log(Thread::current(), "Thread exited: " INTPTR_FORMAT, p2i(p));
1235 }
1236
1237 // Operations on the Threads list for GC. These are not explicitly locked,
1238 // but the garbage collector must provide a safe context for them to run.
1239 // In particular, these things should never be called when the Threads_lock
1240 // is held by some other thread. (Note: the Safepoint abstraction also
1241 // uses the Threads_lock to guarantee this property. It also makes sure that
1242 // all threads gets blocked when exiting or starting).
1243
1244 void Threads::oops_do(OopClosure* f, NMethodClosure* cf) {
1245 ALL_JAVA_THREADS(p) {
1246 p->oops_do(f, cf);
1247 }
1248 VMThread::vm_thread()->oops_do(f, cf);
1249 }
1250
1251 void Threads::change_thread_claim_token() {
1252 if (++_thread_claim_token == 0) {
1253 // On overflow of the token counter, there is a risk of future
1254 // collisions between a new global token value and a stale token
1255 // for a thread, because not all iterations visit all threads.
1256 // (Though it's pretty much a theoretical concern for non-trivial
1257 // token counter sizes.) To deal with the possibility, reset all
1258 // the thread tokens to zero on global token overflow.
1259 struct ResetClaims : public ThreadClosure {
1260 virtual void do_thread(Thread* t) {
1261 t->claim_threads_do(false, 0);
1262 }
1263 } reset_claims;
1264 Threads::threads_do(&reset_claims);
1265 // On overflow, update the global token to non-zero, to
1266 // avoid the special "never claimed" initial thread value.
1267 _thread_claim_token = 1;
1268 }
1269 }
1270
1271 #ifdef ASSERT
1272 static void assert_thread_claimed(const char* kind, Thread* t, uintx expected) {
1273 const uintx token = t->threads_do_token();
1274 assert(token == expected,
1275 "%s " PTR_FORMAT " has incorrect value %zu != %zu",
1276 kind, p2i(t), token, expected);
1277 }
1278
1279 void Threads::assert_all_threads_claimed() {
1280 ALL_JAVA_THREADS(p) {
1281 assert_thread_claimed("JavaThread", p, _thread_claim_token);
1282 }
1283
1284 struct NJTClaimedVerifierClosure : public ThreadClosure {
1285 uintx _thread_claim_token;
1286
1287 NJTClaimedVerifierClosure(uintx thread_claim_token) : ThreadClosure(), _thread_claim_token(thread_claim_token) { }
1288
1289 virtual void do_thread(Thread* thread) override {
1290 assert_thread_claimed("Non-JavaThread", VMThread::vm_thread(), _thread_claim_token);
1291 }
1292 } tc(_thread_claim_token);
1293
1294 non_java_threads_do(&tc);
1295 }
1296 #endif // ASSERT
1297
1298 class ParallelOopsDoThreadClosure : public ThreadClosure {
1299 private:
1300 OopClosure* _f;
1301 NMethodClosure* _cf;
1302 public:
1303 ParallelOopsDoThreadClosure(OopClosure* f, NMethodClosure* cf) : _f(f), _cf(cf) {}
1304 void do_thread(Thread* t) {
1305 t->oops_do(_f, _cf);
1306 }
1307 };
1308
1309 void Threads::possibly_parallel_oops_do(bool is_par, OopClosure* f, NMethodClosure* cf) {
1310 ParallelOopsDoThreadClosure tc(f, cf);
1311 possibly_parallel_threads_do(is_par, &tc);
1312 }
1313
1314 void Threads::metadata_do(MetadataClosure* f) {
1315 ALL_JAVA_THREADS(p) {
1316 p->metadata_do(f);
1317 }
1318 }
1319
1320 class ThreadHandlesClosure : public ThreadClosure {
1321 void (*_f)(Metadata*);
1322 public:
1323 ThreadHandlesClosure(void f(Metadata*)) : _f(f) {}
1324 virtual void do_thread(Thread* thread) {
1325 thread->metadata_handles_do(_f);
1326 }
1327 };
1328
1329 void Threads::metadata_handles_do(void f(Metadata*)) {
1330 // Only walk the Handles in Thread.
1331 ThreadHandlesClosure handles_closure(f);
1332 threads_do(&handles_closure);
1333 }
1334
1335 #if INCLUDE_JVMTI
1336 // Get Java threads that are waiting to enter or re-enter the specified monitor.
1337 // Java threads that are executing mounted virtual threads are not included.
1338 GrowableArray<JavaThread*>* Threads::get_pending_threads(ThreadsList * t_list,
1339 int count,
1340 address monitor) {
1341 assert(Thread::current()->is_VM_thread(), "Must be the VM thread");
1342 GrowableArray<JavaThread*>* result = new GrowableArray<JavaThread*>(count);
1343
1344 int i = 0;
1345 for (JavaThread* p : *t_list) {
1346 if (!p->can_call_java()) continue;
1347
1348 oop thread_oop = JvmtiEnvBase::get_vthread_or_thread_oop(p);
1349 if (thread_oop->is_a(vmClasses::BaseVirtualThread_klass())) {
1350 continue;
1351 }
1352 // The first stage of async deflation does not affect any field
1353 // used by this comparison so the ObjectMonitor* is usable here.
1354 address pending = (address)p->current_pending_monitor();
1355 address waiting = (address)p->current_waiting_monitor();
1356 // do not include virtual threads to the list
1357 jint state = JvmtiEnvBase::get_thread_state(thread_oop, p);
1358 if (pending == monitor || (waiting == monitor &&
1359 (state & JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER))
1360 ) { // found a match
1361 if (i < count) result->append(p); // save the first count matches
1362 i++;
1363 }
1364 }
1365
1366 return result;
1367 }
1368 #endif // INCLUDE_JVMTI
1369
1370 JavaThread *Threads::owning_thread_from_stacklock(ThreadsList * t_list, address basicLock) {
1371 assert(LockingMode == LM_LEGACY, "Not with new lightweight locking");
1372
1373 JavaThread* the_owner = nullptr;
1374 for (JavaThread* q : *t_list) {
1375 if (q->is_lock_owned(basicLock)) {
1376 the_owner = q;
1377 break;
1378 }
1379 }
1380 return the_owner;
1381 }
1382
1383 JavaThread* Threads::owning_thread_from_object(ThreadsList * t_list, oop obj) {
1384 assert(LockingMode == LM_LIGHTWEIGHT, "Only with new lightweight locking");
1385 for (JavaThread* q : *t_list) {
1386 // Need to start processing before accessing oops in the thread.
1387 StackWatermark* watermark = StackWatermarkSet::get(q, StackWatermarkKind::gc);
1388 if (watermark != nullptr) {
1389 watermark->start_processing();
1390 }
1391
1392 if (q->lock_stack().contains(obj)) {
1393 return q;
1394 }
1395 }
1396 return nullptr;
1397 }
1398
1399 JavaThread* Threads::owning_thread_from_monitor(ThreadsList* t_list, ObjectMonitor* monitor) {
1400 if (monitor->has_anonymous_owner()) {
1401 if (LockingMode == LM_LIGHTWEIGHT) {
1402 return owning_thread_from_object(t_list, monitor->object());
1403 } else {
1404 assert(LockingMode == LM_LEGACY, "invariant");
1405 return owning_thread_from_stacklock(t_list, (address)monitor->stack_locker());
1406 }
1407 } else {
1408 JavaThread* the_owner = nullptr;
1409 for (JavaThread* q : *t_list) {
1410 if (monitor->has_owner(q)) {
1411 the_owner = q;
1412 break;
1413 }
1414 }
1415 return the_owner;
1416 }
1417 }
1418
1419 class PrintOnClosure : public ThreadClosure {
1420 private:
1421 outputStream* _st;
1422
1423 public:
1424 PrintOnClosure(outputStream* st) :
1425 _st(st) {}
1426
1427 virtual void do_thread(Thread* thread) {
1428 if (thread != nullptr) {
1429 thread->print_on(_st);
1430 _st->cr();
1431 }
1432 }
1433 };
1434
1435 // Threads::print_on() is called at safepoint by VM_PrintThreads operation.
1436 void Threads::print_on(outputStream* st, bool print_stacks,
1437 bool internal_format, bool print_concurrent_locks,
1438 bool print_extended_info) {
1439 char buf[32];
1440 st->print_raw_cr(os::local_time_string(buf, sizeof(buf)));
1441
1442 st->print_cr("Full thread dump %s (%s %s)",
1443 VM_Version::vm_name(),
1444 VM_Version::vm_release(),
1445 VM_Version::vm_info_string());
1446 JDK_Version::current().to_string(buf, sizeof(buf));
1447 const char* runtime_name = JDK_Version::runtime_name() != nullptr ?
1448 JDK_Version::runtime_name() : "";
1449 const char* runtime_version = JDK_Version::runtime_version() != nullptr ?
1450 JDK_Version::runtime_version() : "";
1451 const char* vendor_version = JDK_Version::runtime_vendor_version() != nullptr ?
1452 JDK_Version::runtime_vendor_version() : "";
1453 const char* jdk_debug_level = VM_Version::printable_jdk_debug_level() != nullptr ?
1454 VM_Version::printable_jdk_debug_level() : "";
1455
1456 st->print_cr(" JDK version: %s%s%s (%s) (%sbuild %s)", runtime_name,
1457 (*vendor_version != '\0') ? " " : "", vendor_version,
1458 buf, jdk_debug_level, runtime_version);
1459
1460 st->cr();
1461
1462 #if INCLUDE_SERVICES
1463 // Dump concurrent locks
1464 ConcurrentLocksDump concurrent_locks;
1465 if (print_concurrent_locks) {
1466 concurrent_locks.dump_at_safepoint();
1467 }
1468 #endif // INCLUDE_SERVICES
1469
1470 ThreadsSMRSupport::print_info_on(st);
1471 st->cr();
1472
1473 ALL_JAVA_THREADS(p) {
1474 ResourceMark rm;
1475 p->print_on(st, print_extended_info);
1476 if (print_stacks) {
1477 if (internal_format) {
1478 p->trace_stack();
1479 } else {
1480 p->print_stack_on(st);
1481 if (p->is_vthread_mounted()) {
1482 st->print_cr(" Mounted virtual thread #" INT64_FORMAT, java_lang_Thread::thread_id(p->vthread()));
1483 p->print_vthread_stack_on(st);
1484 }
1485 }
1486 }
1487 st->cr();
1488 #if INCLUDE_SERVICES
1489 if (print_concurrent_locks) {
1490 concurrent_locks.print_locks_on(p, st);
1491 }
1492 #endif // INCLUDE_SERVICES
1493 }
1494
1495 PrintOnClosure cl(st);
1496 non_java_threads_do(&cl);
1497
1498 st->flush();
1499 }
1500
1501 void Threads::print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
1502 int buflen, bool* found_current) {
1503 if (this_thread != nullptr) {
1504 bool is_current = (current == this_thread);
1505 *found_current = *found_current || is_current;
1506 st->print("%s", is_current ? "=>" : " ");
1507
1508 st->print(PTR_FORMAT, p2i(this_thread));
1509 st->print(" ");
1510 this_thread->print_on_error(st, buf, buflen);
1511 st->cr();
1512 }
1513 }
1514
1515 class PrintOnErrorClosure : public ThreadClosure {
1516 outputStream* _st;
1517 Thread* _current;
1518 char* _buf;
1519 int _buflen;
1520 bool* _found_current;
1521 unsigned _num_printed;
1522 public:
1523 PrintOnErrorClosure(outputStream* st, Thread* current, char* buf,
1524 int buflen, bool* found_current) :
1525 _st(st), _current(current), _buf(buf), _buflen(buflen), _found_current(found_current),
1526 _num_printed(0) {}
1527
1528 virtual void do_thread(Thread* thread) {
1529 _num_printed++;
1530 Threads::print_on_error(thread, _st, _current, _buf, _buflen, _found_current);
1531 }
1532
1533 unsigned num_printed() const { return _num_printed; }
1534 };
1535
1536 // Threads::print_on_error() is called by fatal error handler. It's possible
1537 // that VM is not at safepoint and/or current thread is inside signal handler.
1538 // Don't print stack trace, as the stack may not be walkable. Don't allocate
1539 // memory (even in resource area), it might deadlock the error handler.
1540 void Threads::print_on_error(outputStream* st, Thread* current, char* buf,
1541 int buflen) {
1542 ThreadsSMRSupport::print_info_on(st);
1543 st->cr();
1544
1545 bool found_current = false;
1546 st->print_cr("Java Threads: ( => current thread )");
1547 unsigned num_java = 0;
1548 ALL_JAVA_THREADS(thread) {
1549 print_on_error(thread, st, current, buf, buflen, &found_current);
1550 num_java++;
1551 }
1552 st->print_cr("Total: %u", num_java);
1553 st->cr();
1554
1555 st->print_cr("Other Threads:");
1556 unsigned num_other = ((VMThread::vm_thread() != nullptr) ? 1 : 0) +
1557 ((WatcherThread::watcher_thread() != nullptr) ? 1 : 0) +
1558 ((AsyncLogWriter::instance() != nullptr) ? 1 : 0);
1559 print_on_error(VMThread::vm_thread(), st, current, buf, buflen, &found_current);
1560 print_on_error(WatcherThread::watcher_thread(), st, current, buf, buflen, &found_current);
1561 print_on_error(AsyncLogWriter::instance(), st, current, buf, buflen, &found_current);
1562
1563 if (Universe::heap() != nullptr) {
1564 PrintOnErrorClosure print_closure(st, current, buf, buflen, &found_current);
1565 Universe::heap()->gc_threads_do(&print_closure);
1566 num_other += print_closure.num_printed();
1567 }
1568
1569 if (!found_current) {
1570 st->cr();
1571 st->print("=>" PTR_FORMAT " (exited) ", p2i(current));
1572 current->print_on_error(st, buf, buflen);
1573 num_other++;
1574 st->cr();
1575 }
1576 st->print_cr("Total: %u", num_other);
1577 st->cr();
1578
1579 st->print_cr("Threads with active compile tasks:");
1580 unsigned num = print_threads_compiling(st, buf, buflen);
1581 st->print_cr("Total: %u", num);
1582 }
1583
1584 unsigned Threads::print_threads_compiling(outputStream* st, char* buf, int buflen, bool short_form) {
1585 unsigned num = 0;
1586 ALL_JAVA_THREADS(thread) {
1587 if (thread->is_Compiler_thread()) {
1588 CompilerThread* ct = (CompilerThread*) thread;
1589
1590 // Keep task in local variable for null check.
1591 // ct->_task might be set to null by concurring compiler thread
1592 // because it completed the compilation. The task is never freed,
1593 // though, just returned to a free list.
1594 CompileTask* task = ct->task();
1595 if (task != nullptr) {
1596 thread->print_name_on_error(st, buf, buflen);
1597 st->print(" ");
1598 task->print(st, nullptr, short_form, true);
1599 num++;
1600 }
1601 }
1602 }
1603 return num;
1604 }
1605
1606 void Threads::verify() {
1607 ALL_JAVA_THREADS(p) {
1608 p->verify();
1609 }
1610 VMThread* thread = VMThread::vm_thread();
1611 if (thread != nullptr) thread->verify();
1612 }