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