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