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