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 // This is before the execution of the very first Java bytecode.
347 if (CDSConfig::is_using_aot_linked_classes()) {
348 AOTLinkedClassBulkLoader::link_classes(THREAD);
349 }
350
351 initialize_class(vmSymbols::java_lang_String(), CHECK);
352
353 // Inject CompactStrings value after the static initializers for String ran.
354 java_lang_String::set_compact_strings(CompactStrings);
355
356 // Initialize java_lang.System (needed before creating the thread)
357 initialize_class(vmSymbols::java_lang_System(), CHECK);
358 // The VM creates & returns objects of this class. Make sure it's initialized.
359 initialize_class(vmSymbols::java_lang_Class(), CHECK);
360
361 initialize_class(vmSymbols::java_lang_ThreadGroup(), CHECK);
362 Handle thread_group = create_initial_thread_group(CHECK);
363 Universe::set_main_thread_group(thread_group());
364 initialize_class(vmSymbols::java_lang_Thread(), CHECK);
365 create_initial_thread(thread_group, main_thread, CHECK);
366
367 HeapShared::init_box_classes(CHECK);
368
369 // The VM creates objects of this class.
370 initialize_class(vmSymbols::java_lang_Module(), CHECK);
371
372 #ifdef ASSERT
373 InstanceKlass *k = vmClasses::UnsafeConstants_klass();
374 assert(k->is_not_initialized(), "UnsafeConstants should not already be initialized");
375 #endif
376
377 // initialize the hardware-specific constants needed by Unsafe
378 initialize_class(vmSymbols::jdk_internal_misc_UnsafeConstants(), CHECK);
379 jdk_internal_misc_UnsafeConstants::set_unsafe_constants();
380
381 // The VM preresolves methods to these classes. Make sure that they get initialized
382 initialize_class(vmSymbols::java_lang_reflect_Method(), CHECK);
383 initialize_class(vmSymbols::java_lang_ref_Finalizer(), CHECK);
384
385 // Phase 1 of the system initialization in the library, java.lang.System class initialization
386 call_initPhase1(CHECK);
387
388 // Get the Java runtime name, version, and vendor info after java.lang.System is initialized.
389 // Some values are actually configure-time constants but some can be set via the jlink tool and
390 // so must be read dynamically. We treat them all the same.
391 InstanceKlass* ik = SystemDictionary::find_instance_klass(THREAD, vmSymbols::java_lang_VersionProps(),
392 Handle());
393 {
394 ResourceMark rm(main_thread);
395 JDK_Version::set_java_version(get_java_version_info(ik, vmSymbols::java_version_name()));
396
397 JDK_Version::set_runtime_name(get_java_version_info(ik, vmSymbols::java_runtime_name_name()));
398
399 JDK_Version::set_runtime_version(get_java_version_info(ik, vmSymbols::java_runtime_version_name()));
400
401 JDK_Version::set_runtime_vendor_version(get_java_version_info(ik, vmSymbols::java_runtime_vendor_version_name()));
402
403 JDK_Version::set_runtime_vendor_vm_bug_url(get_java_version_info(ik, vmSymbols::java_runtime_vendor_vm_bug_url_name()));
404 }
405
406 // an instance of OutOfMemory exception has been allocated earlier
407 initialize_class(vmSymbols::java_lang_OutOfMemoryError(), CHECK);
408 initialize_class(vmSymbols::java_lang_NullPointerException(), CHECK);
409 initialize_class(vmSymbols::java_lang_ClassCastException(), CHECK);
410 initialize_class(vmSymbols::java_lang_ArrayStoreException(), CHECK);
411 initialize_class(vmSymbols::java_lang_ArithmeticException(), CHECK);
412 initialize_class(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), CHECK);
413 initialize_class(vmSymbols::java_lang_StackOverflowError(), CHECK);
414 initialize_class(vmSymbols::java_lang_IllegalMonitorStateException(), CHECK);
415 initialize_class(vmSymbols::java_lang_IdentityException(), 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 // Set flag that basic initialization has completed. Used by exceptions and various
707 // debug stuff, that does not work until all basic classes have been initialized.
708 set_init_completed();
709
710 LogConfiguration::post_initialize();
711 Metaspace::post_initialize();
712 MutexLockerImpl::post_initialize();
713
714 HOTSPOT_VM_INIT_END();
715
716 // record VM initialization completion time
717 #if INCLUDE_MANAGEMENT
718 Management::record_vm_init_completed();
719 #endif // INCLUDE_MANAGEMENT
720
721 log_info(os)("Initialized VM with process ID %d", os::current_process_id());
722
723 if (!FLAG_IS_DEFAULT(CreateCoredumpOnCrash) && CreateCoredumpOnCrash) {
724 char buffer[2*JVM_MAXPATHLEN];
725 os::check_core_dump_prerequisites(buffer, sizeof(buffer), true);
726 }
727
728 // Signal Dispatcher needs to be started before VMInit event is posted
729 os::initialize_jdk_signal_support(CHECK_JNI_ERR);
730
731 // Start Attach Listener if +StartAttachListener or it can't be started lazily
732 if (!DisableAttachMechanism) {
733 AttachListener::vm_start();
734 if (StartAttachListener || AttachListener::init_at_startup()) {
735 AttachListener::init();
736 }
737 }
738
739 // Launch -Xrun agents if EagerXrunInit is not set.
740 if (!EagerXrunInit) {
741 JvmtiAgentList::load_xrun_agents();
742 }
743
744 Arena::start_chunk_pool_cleaner_task();
745
746 // Start the service thread
747 // The service thread enqueues JVMTI deferred events and does various hashtable
748 // and other cleanups. Needs to start before the compilers start posting events.
749 ServiceThread::initialize();
750
751 if (CDSConfig::is_using_aot_linked_classes()) {
752 nmethod::post_delayed_compiled_method_load_events();
753 }
754
755 // Start the monitor deflation thread:
756 MonitorDeflationThread::initialize();
757
758 // initialize compiler(s)
759 #if defined(COMPILER1) || COMPILER2_OR_JVMCI
760 bool init_compilation = true;
761 #if INCLUDE_JVMCI
762 bool force_JVMCI_initialization = false;
763 if (EnableJVMCI) {
764 // Initialize JVMCI eagerly when it is explicitly requested.
765 // Or when JVMCILibDumpJNIConfig or JVMCIPrintProperties is enabled.
766 force_JVMCI_initialization = EagerJVMCI || JVMCIPrintProperties || JVMCILibDumpJNIConfig;
767 if (!force_JVMCI_initialization && UseJVMCICompiler && !UseJVMCINativeLibrary && (!UseInterpreter || !BackgroundCompilation)) {
768 // Force initialization of jarjvmci otherwise requests for blocking
769 // compilations will not actually block until jarjvmci is initialized.
770 force_JVMCI_initialization = true;
771 }
772 if (JVMCIPrintProperties || JVMCILibDumpJNIConfig) {
773 // Both JVMCILibDumpJNIConfig and JVMCIPrintProperties exit the VM
774 // so compilation should be disabled. This prevents dumping or
775 // printing from happening more than once.
776 init_compilation = false;
777 }
778 }
779 #endif
780 if (init_compilation) {
781 CompileBroker::compilation_init(CHECK_JNI_ERR);
782 }
783 #endif
784
785 if (CDSConfig::is_using_aot_linked_classes()) {
786 SystemDictionary::restore_archived_method_handle_intrinsics();
787 AOTLinkedClassBulkLoader::init_javabase_classes(THREAD);
788 }
789
790 // Start string deduplication thread if requested.
791 if (StringDedup::is_enabled()) {
792 StringDedup::start();
793 }
794
795 // Pre-initialize some JSR292 core classes to avoid deadlock during class loading.
796 // It is done after compilers are initialized, because otherwise compilations of
797 // signature polymorphic MH intrinsics can be missed
798 // (see SystemDictionary::find_method_handle_intrinsic).
799 initialize_jsr292_core_classes(CHECK_JNI_ERR);
800
801 // This will initialize the module system. Only java.base classes can be
802 // loaded until phase 2 completes
803 call_initPhase2(CHECK_JNI_ERR);
804
805 if (CDSConfig::is_using_aot_linked_classes()) {
806 AOTLinkedClassBulkLoader::init_non_javabase_classes(THREAD);
807 }
808 #ifndef PRODUCT
809 HeapShared::initialize_test_class_from_archive(THREAD);
810 #endif
811
812 JFR_ONLY(Jfr::on_create_vm_2();)
813
814 // Always call even when there are not JVMTI environments yet, since environments
815 // may be attached late and JVMTI must track phases of VM execution
816 JvmtiExport::enter_start_phase();
817
818 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
819 JvmtiExport::post_vm_start();
820
821 // Final system initialization including security manager and system class loader
822 call_initPhase3(CHECK_JNI_ERR);
823
824 // cache the system and platform class loaders
825 SystemDictionary::compute_java_loaders(CHECK_JNI_ERR);
826
827 // Initiate replay training processing once preloading is over.
828 CompileBroker::init_training_replay();
829
830 AOTLinkedClassBulkLoader::replay_training_at_init_for_preloaded_classes(CHECK_JNI_ERR);
831
832 if (Continuations::enabled()) {
833 // Initialize Continuation class now so that failure to create enterSpecial/doYield
834 // special nmethods due to limited CodeCache size can be treated as a fatal error at
835 // startup with the proper message that CodeCache size is too small.
836 initialize_class(vmSymbols::jdk_internal_vm_Continuation(), CHECK_JNI_ERR);
837 }
838
839 if (NativeHeapTrimmer::enabled()) {
840 NativeHeapTrimmer::initialize();
841 }
842
843 // Always call even when there are not JVMTI environments yet, since environments
844 // may be attached late and JVMTI must track phases of VM execution
845 JvmtiExport::enter_live_phase();
846
847 // Make perfmemory accessible
848 PerfMemory::set_accessible(true);
849
850 // Notify JVMTI agents that VM initialization is complete - nop if no agents.
851 JvmtiExport::post_vm_initialized();
852
853 #if INCLUDE_JVMCI
854 if (force_JVMCI_initialization) {
855 JVMCI::initialize_compiler_in_create_vm(CHECK_JNI_ERR);
856 }
857 #endif
858
859 JFR_ONLY(Jfr::on_create_vm_3();)
860
861 #if INCLUDE_MANAGEMENT
862 bool start_agent = true;
863 #if INCLUDE_CDS
864 start_agent = !CDSConfig::is_dumping_final_static_archive();
865 if (!start_agent) {
866 log_info(aot)("Not starting management agent during creation of AOT cache.");
867 }
868 #endif // INCLUDE_CDS
869 if (start_agent) {
870 Management::initialize(THREAD);
871
872 if (HAS_PENDING_EXCEPTION) {
873 // management agent fails to start possibly due to
874 // configuration problem and is responsible for printing
875 // stack trace if appropriate. Simply exit VM.
876 vm_exit(1);
877 }
878 }
879 #endif // INCLUDE_MANAGEMENT
880
881 if (UsePerfData) PerfDataManager::create_misc_perfdata();
882 if (CheckJNICalls) JniPeriodicChecker::engage();
883
884 call_postVMInitHook(THREAD);
885 // The Java side of PostVMInitHook.run must deal with all
886 // exceptions and provide means of diagnosis.
887 if (HAS_PENDING_EXCEPTION) {
888 CLEAR_PENDING_EXCEPTION;
889 }
890
891 // Let WatcherThread run all registered periodic tasks now.
892 // NOTE: All PeriodicTasks should be registered by now. If they
893 // aren't, late joiners might appear to start slowly (we might
894 // take a while to process their first tick).
895 WatcherThread::run_all_tasks();
896
897 create_vm_timer.end();
898 #ifdef ASSERT
899 _vm_complete = true;
900 #endif
901
902 if (CDSConfig::is_dumping_classic_static_archive()) {
903 // Classic -Xshare:dump, aka "old workflow"
904 AOTMetaspace::dump_static_archive(CHECK_JNI_ERR);
905 } else if (CDSConfig::is_dumping_final_static_archive()) {
906 tty->print_cr("Reading AOTConfiguration %s and writing AOTCache %s", AOTConfiguration, AOTCache);
907 AOTMetaspace::dump_static_archive(CHECK_JNI_ERR);
908 }
909
910 if (log_is_enabled(Info, perf, class, link)) {
911 LogStreamHandle(Info, perf, class, link) log;
912 log.print_cr("At VM initialization completion:");
913 ClassLoader::print_counters(&log);
914 }
915
916 return JNI_OK;
917 }
918
919 // Threads::destroy_vm() is normally called from jni_DestroyJavaVM() when
920 // the program falls off the end of main(). Another VM exit path is through
921 // vm_exit(), when the program calls System.exit() to return a value, or when
922 // there is a serious error in VM.
923 // These two separate shutdown paths are not exactly the same, but they share
924 // Shutdown.shutdown() at Java level and before_exit() and VM_Exit op at VM level.
925 //
926 // Shutdown sequence:
927 // + Shutdown native memory tracking if it is on
928 // + Wait until we are the last non-daemon thread to execute
929 // <-- every thing is still working at this moment -->
930 // + Call java.lang.Shutdown.shutdown(), which will invoke Java level
931 // shutdown hooks
932 // + Call before_exit(), prepare for VM exit
933 // > run VM level shutdown hooks (they are registered through JVM_OnExit(),
934 // currently the only user of this mechanism is File.deleteOnExit())
935 // > stop watcher thread,
936 // post thread end and vm death events to JVMTI,
937 // stop signal thread
938 // + Call JavaThread::exit(), it will:
939 // > release JNI handle blocks, remove stack guard pages
940 // > remove this thread from Threads list
941 // <-- no more Java code from this thread after this point -->
942 // + Stop VM thread, it will bring the remaining VM to a safepoint and stop
943 // the compiler threads at safepoint
944 // <-- do not use anything that could get blocked by Safepoint -->
945 // + Disable tracing at JNI/JVM barriers
946 // + Set _vm_exited flag for threads that are still running native code
947 // + Call exit_globals()
948 // > deletes tty
949 // > deletes PerfMemory resources
950 // + Delete this thread
951 // + Return to caller
952
953 void Threads::destroy_vm() {
954 JavaThread* thread = JavaThread::current();
955
956 #ifdef ASSERT
957 _vm_complete = false;
958 #endif
959 // Wait until we are the last non-daemon thread to execute, or
960 // if we are a daemon then wait until the last non-daemon thread has
961 // executed.
962 bool daemon = java_lang_Thread::is_daemon(thread->threadObj());
963 int expected = daemon ? 0 : 1;
964 {
965 MonitorLocker nu(Threads_lock);
966 while (Threads::number_of_non_daemon_threads() > expected)
967 // This wait should make safepoint checks, wait without a timeout.
968 nu.wait(0);
969 }
970
971 EventShutdown e;
972 if (e.should_commit()) {
973 e.set_reason("No remaining non-daemon Java threads");
974 e.commit();
975 }
976
977 // Hang forever on exit if we are reporting an error.
978 if (ShowMessageBoxOnError && VMError::is_error_reported()) {
979 os::infinite_sleep();
980 }
981 os::wait_for_keypress_at_exit();
982
983 // run Java level shutdown hooks
984 thread->invoke_shutdown_hooks();
985
986 before_exit(thread);
987
988 thread->exit(true);
989
990 // We are no longer on the main thread list but could still be in a
991 // secondary list where another thread may try to interact with us.
992 // So wait until all such interactions are complete before we bring
993 // the VM to the termination safepoint. Normally this would be done
994 // using thread->smr_delete() below where we delete the thread, but
995 // we can't call that after the termination safepoint is active as
996 // we will deadlock on the Threads_lock. Once all interactions are
997 // complete it is safe to directly delete the thread at any time.
998 ThreadsSMRSupport::wait_until_not_protected(thread);
999
1000 // Stop VM thread.
1001 {
1002 // 4945125 The vm thread comes to a safepoint during exit.
1003 // GC vm_operations can get caught at the safepoint, and the
1004 // heap is unparseable if they are caught. Grab the Heap_lock
1005 // to prevent this. The GC vm_operations will not be able to
1006 // queue until after the vm thread is dead. After this point,
1007 // we'll never emerge out of the safepoint before the VM exits.
1008 // Assert that the thread is terminated so that acquiring the
1009 // Heap_lock doesn't cause the terminated thread to participate in
1010 // the safepoint protocol.
1011
1012 assert(thread->is_terminated(), "must be terminated here");
1013 MutexLocker ml(Heap_lock);
1014
1015 VMThread::wait_for_vm_thread_exit();
1016 assert(SafepointSynchronize::is_at_safepoint(), "VM thread should exit at Safepoint");
1017 VMThread::destroy();
1018 }
1019
1020 // Now, all Java threads are gone except daemon threads. Daemon threads
1021 // running Java code or in VM are stopped by the Safepoint. However,
1022 // daemon threads executing native code are still running. But they
1023 // will be stopped at native=>Java/VM barriers. Note that we can't
1024 // simply kill or suspend them, as it is inherently deadlock-prone.
1025
1026 VM_Exit::set_vm_exited();
1027
1028 // Clean up ideal graph printers after the VMThread has started
1029 // the final safepoint which will block all the Compiler threads.
1030 // Note that this Thread has already logically exited so the
1031 // clean_up() function's use of a JavaThreadIteratorWithHandle
1032 // would be a problem except set_vm_exited() has remembered the
1033 // shutdown thread which is granted a policy exception.
1034 #if defined(COMPILER2) && !defined(PRODUCT)
1035 IdealGraphPrinter::clean_up();
1036 #endif
1037
1038 notify_vm_shutdown();
1039
1040 // exit_globals() will delete tty
1041 exit_globals();
1042
1043 // Deleting the shutdown thread here is safe. See comment on
1044 // wait_until_not_protected() above.
1045 delete thread;
1046
1047 #if INCLUDE_JVMCI
1048 if (JVMCICounterSize > 0) {
1049 FREE_C_HEAP_ARRAY(jlong, JavaThread::_jvmci_old_thread_counters);
1050 }
1051 #endif
1052
1053 LogConfiguration::finalize();
1054 }
1055
1056
1057 jboolean Threads::is_supported_jni_version_including_1_1(jint version) {
1058 if (version == JNI_VERSION_1_1) return JNI_TRUE;
1059 return is_supported_jni_version(version);
1060 }
1061
1062
1063 jboolean Threads::is_supported_jni_version(jint version) {
1064 if (version == JNI_VERSION_1_2) return JNI_TRUE;
1065 if (version == JNI_VERSION_1_4) return JNI_TRUE;
1066 if (version == JNI_VERSION_1_6) return JNI_TRUE;
1067 if (version == JNI_VERSION_1_8) return JNI_TRUE;
1068 if (version == JNI_VERSION_9) return JNI_TRUE;
1069 if (version == JNI_VERSION_10) return JNI_TRUE;
1070 if (version == JNI_VERSION_19) return JNI_TRUE;
1071 if (version == JNI_VERSION_20) return JNI_TRUE;
1072 if (version == JNI_VERSION_21) return JNI_TRUE;
1073 if (version == JNI_VERSION_24) return JNI_TRUE;
1074 return JNI_FALSE;
1075 }
1076
1077 void Threads::add(JavaThread* p, bool force_daemon) {
1078 // The threads lock must be owned at this point
1079 assert(Threads_lock->owned_by_self(), "must have threads lock");
1080 assert(p->monitor_owner_id() != 0, "should be set");
1081
1082 BarrierSet::barrier_set()->on_thread_attach(p);
1083
1084 // Once a JavaThread is added to the Threads list, smr_delete() has
1085 // to be used to delete it. Otherwise we can just delete it directly.
1086 p->set_on_thread_list();
1087
1088 _number_of_threads++;
1089 oop threadObj = p->threadObj();
1090 bool daemon = true;
1091 // Bootstrapping problem: threadObj can be null for initial
1092 // JavaThread (or for threads attached via JNI)
1093 if (!force_daemon &&
1094 (threadObj == nullptr || !java_lang_Thread::is_daemon(threadObj))) {
1095 _number_of_non_daemon_threads++;
1096 daemon = false;
1097 }
1098
1099 ThreadService::add_thread(p, daemon);
1100
1101 // Maintain fast thread list
1102 ThreadsSMRSupport::add_thread(p);
1103
1104 // Increase the ObjectMonitor ceiling for the new thread.
1105 ObjectSynchronizer::inc_in_use_list_ceiling();
1106
1107 // Possible GC point.
1108 Events::log(Thread::current(), "Thread added: " INTPTR_FORMAT, p2i(p));
1109
1110 // Make new thread known to active EscapeBarrier
1111 EscapeBarrier::thread_added(p);
1112 }
1113
1114 void Threads::remove(JavaThread* p, bool is_daemon) {
1115 // Extra scope needed for Thread_lock, so we can check
1116 // that we do not remove thread without safepoint code notice
1117 {
1118 ConditionalMutexLocker throttle_ml(ThreadsLockThrottle_lock, UseThreadsLockThrottleLock);
1119 MonitorLocker ml(Threads_lock);
1120
1121 if (ThreadIdTable::is_initialized()) {
1122 // This cleanup must be done before the current thread's GC barrier
1123 // is detached since we need to touch the threadObj oop.
1124 jlong tid = SharedRuntime::get_java_tid(p);
1125 ThreadIdTable::remove_thread(tid);
1126 }
1127
1128 // BarrierSet state must be destroyed after the last thread transition
1129 // before the thread terminates. Thread transitions result in calls to
1130 // StackWatermarkSet::on_safepoint(), which performs GC processing,
1131 // requiring the GC state to be alive.
1132 BarrierSet::barrier_set()->on_thread_detach(p);
1133 if (p->is_exiting()) {
1134 // If we got here via JavaThread::exit(), then we remember that the
1135 // thread's GC barrier has been detached. We don't do this when we get
1136 // here from another path, e.g., cleanup_failed_attach_current_thread().
1137 p->set_terminated(JavaThread::_thread_gc_barrier_detached);
1138 }
1139
1140 assert(ThreadsSMRSupport::get_java_thread_list()->includes(p), "p must be present");
1141
1142 // Maintain fast thread list
1143 ThreadsSMRSupport::remove_thread(p);
1144
1145 _number_of_threads--;
1146 if (!is_daemon) {
1147 _number_of_non_daemon_threads--;
1148
1149 // If this is the last non-daemon thread then we need to do
1150 // a notify on the Threads_lock so a thread waiting
1151 // on destroy_vm will wake up. But that thread could be a daemon
1152 // or non-daemon, so we notify for both the 0 and 1 case.
1153 if (number_of_non_daemon_threads() <= 1) {
1154 ml.notify_all();
1155 }
1156 }
1157 ThreadService::remove_thread(p, is_daemon);
1158
1159 // Make sure that safepoint code disregard this thread. This is needed since
1160 // the thread might mess around with locks after this point. This can cause it
1161 // to do callbacks into the safepoint code. However, the safepoint code is not aware
1162 // of this thread since it is removed from the queue.
1163 p->set_terminated(JavaThread::_thread_terminated);
1164
1165 // Notify threads waiting in EscapeBarriers
1166 EscapeBarrier::thread_removed(p);
1167 } // unlock Threads_lock and ThreadsLockThrottle_lock
1168
1169 // Reduce the ObjectMonitor ceiling for the exiting thread.
1170 ObjectSynchronizer::dec_in_use_list_ceiling();
1171
1172 // Since Events::log uses a lock, we grab it outside the Threads_lock
1173 Events::log(Thread::current(), "Thread exited: " INTPTR_FORMAT, p2i(p));
1174 }
1175
1176 // Operations on the Threads list for GC. These are not explicitly locked,
1177 // but the garbage collector must provide a safe context for them to run.
1178 // In particular, these things should never be called when the Threads_lock
1179 // is held by some other thread. (Note: the Safepoint abstraction also
1180 // uses the Threads_lock to guarantee this property. It also makes sure that
1181 // all threads gets blocked when exiting or starting).
1182
1183 void Threads::oops_do(OopClosure* f, NMethodClosure* cf) {
1184 ALL_JAVA_THREADS(p) {
1185 p->oops_do(f, cf);
1186 }
1187 VMThread::vm_thread()->oops_do(f, cf);
1188 }
1189
1190 void Threads::change_thread_claim_token() {
1191 if (++_thread_claim_token == 0) {
1192 // On overflow of the token counter, there is a risk of future
1193 // collisions between a new global token value and a stale token
1194 // for a thread, because not all iterations visit all threads.
1195 // (Though it's pretty much a theoretical concern for non-trivial
1196 // token counter sizes.) To deal with the possibility, reset all
1197 // the thread tokens to zero on global token overflow.
1198 struct ResetClaims : public ThreadClosure {
1199 virtual void do_thread(Thread* t) {
1200 t->claim_threads_do(false, 0);
1201 }
1202 } reset_claims;
1203 Threads::threads_do(&reset_claims);
1204 // On overflow, update the global token to non-zero, to
1205 // avoid the special "never claimed" initial thread value.
1206 _thread_claim_token = 1;
1207 }
1208 }
1209
1210 #ifdef ASSERT
1211 static void assert_thread_claimed(const char* kind, Thread* t, uintx expected) {
1212 const uintx token = t->threads_do_token();
1213 assert(token == expected,
1214 "%s " PTR_FORMAT " has incorrect value %zu != %zu",
1215 kind, p2i(t), token, expected);
1216 }
1217
1218 void Threads::assert_all_threads_claimed() {
1219 ALL_JAVA_THREADS(p) {
1220 assert_thread_claimed("JavaThread", p, _thread_claim_token);
1221 }
1222
1223 struct NJTClaimedVerifierClosure : public ThreadClosure {
1224 uintx _thread_claim_token;
1225
1226 NJTClaimedVerifierClosure(uintx thread_claim_token) : ThreadClosure(), _thread_claim_token(thread_claim_token) { }
1227
1228 virtual void do_thread(Thread* thread) override {
1229 assert_thread_claimed("Non-JavaThread", VMThread::vm_thread(), _thread_claim_token);
1230 }
1231 } tc(_thread_claim_token);
1232
1233 non_java_threads_do(&tc);
1234 }
1235 #endif // ASSERT
1236
1237 class ParallelOopsDoThreadClosure : public ThreadClosure {
1238 private:
1239 OopClosure* _f;
1240 NMethodClosure* _cf;
1241 public:
1242 ParallelOopsDoThreadClosure(OopClosure* f, NMethodClosure* cf) : _f(f), _cf(cf) {}
1243 void do_thread(Thread* t) {
1244 t->oops_do(_f, _cf);
1245 }
1246 };
1247
1248 void Threads::possibly_parallel_oops_do(bool is_par, OopClosure* f, NMethodClosure* cf) {
1249 ParallelOopsDoThreadClosure tc(f, cf);
1250 possibly_parallel_threads_do(is_par, &tc);
1251 }
1252
1253 void Threads::metadata_do(MetadataClosure* f) {
1254 ALL_JAVA_THREADS(p) {
1255 p->metadata_do(f);
1256 }
1257 }
1258
1259 class ThreadHandlesClosure : public ThreadClosure {
1260 void (*_f)(Metadata*);
1261 public:
1262 ThreadHandlesClosure(void f(Metadata*)) : _f(f) {}
1263 virtual void do_thread(Thread* thread) {
1264 thread->metadata_handles_do(_f);
1265 }
1266 };
1267
1268 void Threads::metadata_handles_do(void f(Metadata*)) {
1269 // Only walk the Handles in Thread.
1270 ThreadHandlesClosure handles_closure(f);
1271 threads_do(&handles_closure);
1272 }
1273
1274 #if INCLUDE_JVMTI
1275 // Get Java threads that are waiting to enter or re-enter the specified monitor.
1276 // Java threads that are executing mounted virtual threads are not included.
1277 GrowableArray<JavaThread*>* Threads::get_pending_threads(ThreadsList * t_list,
1278 int count,
1279 address monitor) {
1280 assert(Thread::current()->is_VM_thread(), "Must be the VM thread");
1281 GrowableArray<JavaThread*>* result = new GrowableArray<JavaThread*>(count);
1282
1283 int i = 0;
1284 for (JavaThread* p : *t_list) {
1285 if (!p->can_call_java()) continue;
1286
1287 oop thread_oop = JvmtiEnvBase::get_vthread_or_thread_oop(p);
1288 if (thread_oop->is_a(vmClasses::BaseVirtualThread_klass())) {
1289 continue;
1290 }
1291 // The first stage of async deflation does not affect any field
1292 // used by this comparison so the ObjectMonitor* is usable here.
1293 address pending = (address)p->current_pending_monitor();
1294 address waiting = (address)p->current_waiting_monitor();
1295 // do not include virtual threads to the list
1296 jint state = JvmtiEnvBase::get_thread_state(thread_oop, p);
1297 if (pending == monitor || (waiting == monitor &&
1298 (state & JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER))
1299 ) { // found a match
1300 if (i < count) result->append(p); // save the first count matches
1301 i++;
1302 }
1303 }
1304
1305 return result;
1306 }
1307 #endif // INCLUDE_JVMTI
1308
1309 JavaThread* Threads::owning_thread_from_object(ThreadsList * t_list, oop obj) {
1310 for (JavaThread* q : *t_list) {
1311 // Need to start processing before accessing oops in the thread.
1312 StackWatermark* watermark = StackWatermarkSet::get(q, StackWatermarkKind::gc);
1313 if (watermark != nullptr) {
1314 watermark->start_processing();
1315 }
1316
1317 if (q->lock_stack().contains(obj)) {
1318 return q;
1319 }
1320 }
1321 return nullptr;
1322 }
1323
1324 JavaThread* Threads::owning_thread_from_monitor(ThreadsList* t_list, ObjectMonitor* monitor) {
1325 if (monitor->has_anonymous_owner()) {
1326 return owning_thread_from_object(t_list, monitor->object());
1327 } else {
1328 JavaThread* the_owner = nullptr;
1329 for (JavaThread* q : *t_list) {
1330 if (monitor->has_owner(q)) {
1331 the_owner = q;
1332 break;
1333 }
1334 }
1335 return the_owner;
1336 }
1337 }
1338
1339 class PrintOnClosure : public ThreadClosure {
1340 private:
1341 outputStream* _st;
1342
1343 public:
1344 PrintOnClosure(outputStream* st) :
1345 _st(st) {}
1346
1347 virtual void do_thread(Thread* thread) {
1348 if (thread != nullptr) {
1349 thread->print_on(_st);
1350 _st->cr();
1351 }
1352 }
1353 };
1354
1355 // Threads::print_on() is called at safepoint by VM_PrintThreads operation.
1356 void Threads::print_on(outputStream* st, bool print_stacks,
1357 bool internal_format, bool print_concurrent_locks,
1358 bool print_extended_info) {
1359 char buf[32];
1360 st->print_raw_cr(os::local_time_string(buf, sizeof(buf)));
1361
1362 st->print_cr("Full thread dump %s (%s %s)",
1363 VM_Version::vm_name(),
1364 VM_Version::vm_release(),
1365 VM_Version::vm_info_string());
1366 JDK_Version::current().to_string(buf, sizeof(buf));
1367 const char* runtime_name = JDK_Version::runtime_name() != nullptr ?
1368 JDK_Version::runtime_name() : "";
1369 const char* runtime_version = JDK_Version::runtime_version() != nullptr ?
1370 JDK_Version::runtime_version() : "";
1371 const char* vendor_version = JDK_Version::runtime_vendor_version() != nullptr ?
1372 JDK_Version::runtime_vendor_version() : "";
1373 const char* jdk_debug_level = VM_Version::printable_jdk_debug_level() != nullptr ?
1374 VM_Version::printable_jdk_debug_level() : "";
1375
1376 st->print_cr(" JDK version: %s%s%s (%s) (%sbuild %s)", runtime_name,
1377 (*vendor_version != '\0') ? " " : "", vendor_version,
1378 buf, jdk_debug_level, runtime_version);
1379
1380 st->cr();
1381
1382 #if INCLUDE_SERVICES
1383 // Dump concurrent locks
1384 ConcurrentLocksDump concurrent_locks;
1385 if (print_concurrent_locks) {
1386 concurrent_locks.dump_at_safepoint();
1387 }
1388 #endif // INCLUDE_SERVICES
1389
1390 ThreadsSMRSupport::print_info_on(st);
1391 st->cr();
1392
1393 ALL_JAVA_THREADS(p) {
1394 ResourceMark rm;
1395 p->print_on(st, print_extended_info);
1396 if (print_stacks) {
1397 if (internal_format) {
1398 p->trace_stack();
1399 } else {
1400 p->print_stack_on(st);
1401 if (p->is_vthread_mounted()) {
1402 st->print_cr(" Mounted virtual thread #" INT64_FORMAT, java_lang_Thread::thread_id(p->vthread()));
1403 p->print_vthread_stack_on(st);
1404 }
1405 }
1406 }
1407 st->cr();
1408 #if INCLUDE_SERVICES
1409 if (print_concurrent_locks) {
1410 concurrent_locks.print_locks_on(p, st);
1411 }
1412 #endif // INCLUDE_SERVICES
1413 }
1414
1415 PrintOnClosure cl(st);
1416 non_java_threads_do(&cl);
1417
1418 st->flush();
1419 }
1420
1421 void Threads::print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
1422 int buflen, bool* found_current) {
1423 if (this_thread != nullptr) {
1424 bool is_current = (current == this_thread);
1425 *found_current = *found_current || is_current;
1426 st->print("%s", is_current ? "=>" : " ");
1427
1428 st->print(PTR_FORMAT, p2i(this_thread));
1429 st->print(" ");
1430 this_thread->print_on_error(st, buf, buflen);
1431 st->cr();
1432 }
1433 }
1434
1435 class PrintOnErrorClosure : public ThreadClosure {
1436 outputStream* _st;
1437 Thread* _current;
1438 char* _buf;
1439 int _buflen;
1440 bool* _found_current;
1441 unsigned _num_printed;
1442 public:
1443 PrintOnErrorClosure(outputStream* st, Thread* current, char* buf,
1444 int buflen, bool* found_current) :
1445 _st(st), _current(current), _buf(buf), _buflen(buflen), _found_current(found_current),
1446 _num_printed(0) {}
1447
1448 virtual void do_thread(Thread* thread) {
1449 _num_printed++;
1450 Threads::print_on_error(thread, _st, _current, _buf, _buflen, _found_current);
1451 }
1452
1453 unsigned num_printed() const { return _num_printed; }
1454 };
1455
1456 // Threads::print_on_error() is called by fatal error handler. It's possible
1457 // that VM is not at safepoint and/or current thread is inside signal handler.
1458 // Don't print stack trace, as the stack may not be walkable. Don't allocate
1459 // memory (even in resource area), it might deadlock the error handler.
1460 void Threads::print_on_error(outputStream* st, Thread* current, char* buf,
1461 int buflen) {
1462 ThreadsSMRSupport::print_info_on(st);
1463 st->cr();
1464
1465 bool found_current = false;
1466 st->print_cr("Java Threads: ( => current thread )");
1467 unsigned num_java = 0;
1468 ALL_JAVA_THREADS(thread) {
1469 print_on_error(thread, st, current, buf, buflen, &found_current);
1470 num_java++;
1471 }
1472 st->print_cr("Total: %u", num_java);
1473 st->cr();
1474
1475 st->print_cr("Other Threads:");
1476 unsigned num_other = ((VMThread::vm_thread() != nullptr) ? 1 : 0) +
1477 ((WatcherThread::watcher_thread() != nullptr) ? 1 : 0) +
1478 ((AsyncLogWriter::instance() != nullptr) ? 1 : 0);
1479 print_on_error(VMThread::vm_thread(), st, current, buf, buflen, &found_current);
1480 print_on_error(WatcherThread::watcher_thread(), st, current, buf, buflen, &found_current);
1481 print_on_error(AsyncLogWriter::instance(), st, current, buf, buflen, &found_current);
1482
1483 if (Universe::heap() != nullptr) {
1484 PrintOnErrorClosure print_closure(st, current, buf, buflen, &found_current);
1485 Universe::heap()->gc_threads_do(&print_closure);
1486 num_other += print_closure.num_printed();
1487 }
1488
1489 if (!found_current) {
1490 st->cr();
1491 st->print("=>" PTR_FORMAT " (exited) ", p2i(current));
1492 current->print_on_error(st, buf, buflen);
1493 num_other++;
1494 st->cr();
1495 }
1496 st->print_cr("Total: %u", num_other);
1497 st->cr();
1498
1499 st->print_cr("Threads with active compile tasks:");
1500 unsigned num = print_threads_compiling(st, buf, buflen);
1501 st->print_cr("Total: %u", num);
1502 }
1503
1504 unsigned Threads::print_threads_compiling(outputStream* st, char* buf, int buflen, bool short_form) {
1505 unsigned num = 0;
1506 ALL_JAVA_THREADS(thread) {
1507 if (thread->is_Compiler_thread()) {
1508 CompilerThread* ct = (CompilerThread*) thread;
1509
1510 // Keep task in local variable for null check.
1511 // ct->_task might be set to null by concurring compiler thread
1512 // because it completed the compilation. The task is never freed,
1513 // though, just returned to a free list.
1514 CompileTask* task = ct->task();
1515 if (task != nullptr) {
1516 thread->print_name_on_error(st, buf, buflen);
1517 st->print(" ");
1518 task->print(st, nullptr, short_form, true);
1519 num++;
1520 }
1521 }
1522 }
1523 return num;
1524 }
1525
1526 void Threads::verify() {
1527 ALL_JAVA_THREADS(p) {
1528 p->verify();
1529 }
1530 VMThread* thread = VMThread::vm_thread();
1531 if (thread != nullptr) thread->verify();
1532 }