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.inline.hpp"
31 #include "cds/methodProfiler.hpp"
32 #include "classfile/classLoader.hpp"
33 #include "classfile/javaClasses.hpp"
34 #include "classfile/javaThreadStatus.hpp"
35 #include "classfile/symbolTable.hpp"
36 #include "classfile/systemDictionary.hpp"
37 #include "classfile/systemDictionaryShared.hpp"
38 #include "classfile/vmClasses.hpp"
39 #include "classfile/vmSymbols.hpp"
40 #include "code/aotCodeCache.hpp"
41 #include "compiler/compilationPolicy.hpp"
42 #include "compiler/compileBroker.hpp"
43 #include "compiler/compilerThread.hpp"
44 #include "compiler/compileTask.hpp"
45 #include "compiler/precompiler.hpp"
46 #include "gc/shared/barrierSet.hpp"
47 #include "gc/shared/barrierSetNMethod.hpp"
48 #include "gc/shared/gcVMOperations.hpp"
49 #include "gc/shared/oopStorage.hpp"
50 #include "gc/shared/oopStorageSet.hpp"
51 #include "gc/shared/stringdedup/stringDedup.hpp"
52 #include "interpreter/interpreterRuntime.hpp"
53 #include "jfr/jfrEvents.hpp"
54 #include "jvm.h"
55 #include "jvmtifiles/jvmtiEnv.hpp"
56 #include "logging/log.hpp"
57 #include "logging/logAsyncWriter.hpp"
58 #include "logging/logConfiguration.hpp"
59 #include "memory/allocation.inline.hpp"
60 #include "memory/iterator.hpp"
61 #include "memory/oopFactory.hpp"
62 #include "memory/resourceArea.hpp"
63 #include "memory/universe.hpp"
64 #include "nmt/memTracker.hpp"
65 #include "oops/instanceKlass.hpp"
66 #include "oops/klass.inline.hpp"
67 #include "oops/oop.inline.hpp"
68 #include "oops/symbol.hpp"
69 #include "prims/jvm_misc.hpp"
70 #include "prims/jvmtiAgentList.hpp"
71 #include "prims/jvmtiEnvBase.hpp"
72 #include "runtime/arguments.hpp"
73 #include "runtime/fieldDescriptor.inline.hpp"
74 #include "runtime/flags/jvmFlagLimit.hpp"
75 #include "runtime/globals.hpp"
76 #include "runtime/globals_extension.hpp"
77 #include "runtime/handles.inline.hpp"
78 #include "runtime/interfaceSupport.inline.hpp"
79 #include "runtime/java.hpp"
80 #include "runtime/javaCalls.hpp"
81 #include "runtime/javaThread.inline.hpp"
82 #include "runtime/jniHandles.inline.hpp"
83 #include "runtime/jniPeriodicChecker.hpp"
84 #include "runtime/lockStack.inline.hpp"
85 #include "runtime/monitorDeflationThread.hpp"
86 #include "runtime/mutexLocker.hpp"
87 #include "runtime/nonJavaThread.hpp"
88 #include "runtime/objectMonitor.inline.hpp"
89 #include "runtime/osThread.hpp"
90 #include "runtime/perfData.hpp"
91 #include "runtime/safepoint.hpp"
92 #include "runtime/safepointMechanism.inline.hpp"
93 #include "runtime/safepointVerifiers.hpp"
94 #include "runtime/serviceThread.hpp"
95 #include "runtime/sharedRuntime.hpp"
96 #include "runtime/stackWatermarkSet.inline.hpp"
97 #include "runtime/stubCodeGenerator.hpp"
98 #include "runtime/thread.inline.hpp"
99 #include "runtime/threads.hpp"
100 #include "runtime/threadSMR.inline.hpp"
101 #include "runtime/timer.hpp"
102 #include "runtime/timerTrace.hpp"
103 #include "runtime/trimNativeHeap.hpp"
104 #include "runtime/vm_version.hpp"
105 #include "runtime/vmOperations.hpp"
106 #include "sanitizers/address.hpp"
107 #include "services/attachListener.hpp"
108 #include "services/management.hpp"
109 #include "services/threadIdTable.hpp"
110 #include "services/threadService.hpp"
111 #include "utilities/debug.hpp"
112 #include "utilities/dtrace.hpp"
113 #include "utilities/events.hpp"
114 #include "utilities/macros.hpp"
115 #include "utilities/vmError.hpp"
116 #if INCLUDE_JVMCI
117 #include "jvmci/jvmci.hpp"
118 #include "jvmci/jvmciEnv.hpp"
119 #endif
120 #ifdef COMPILER1
121 #include "c1/c1_Runtime1.hpp"
122 #endif
123 #ifdef COMPILER2
124 #include "opto/idealGraphPrinter.hpp"
125 #include "opto/runtime.hpp"
126 #endif
127 #if INCLUDE_JFR
128 #include "jfr/jfr.hpp"
129 #endif
130
131 // Initialization after module runtime initialization
132 void universe_post_module_init(); // must happen after call_initPhase2
133
134
135 static void initialize_class(Symbol* class_name, TRAPS) {
136 Klass* klass = SystemDictionary::resolve_or_fail(class_name, true, CHECK);
137 InstanceKlass::cast(klass)->initialize(CHECK);
138 }
139
140
141 // Creates the initial ThreadGroup
142 static Handle create_initial_thread_group(TRAPS) {
143 Handle system_instance = JavaCalls::construct_new_instance(
144 vmClasses::ThreadGroup_klass(),
145 vmSymbols::void_method_signature(),
146 CHECK_NH);
147 Universe::set_system_thread_group(system_instance());
148
149 Handle string = java_lang_String::create_from_str("main", CHECK_NH);
150 Handle main_instance = JavaCalls::construct_new_instance(
151 vmClasses::ThreadGroup_klass(),
152 vmSymbols::threadgroup_string_void_signature(),
153 system_instance,
154 string,
155 CHECK_NH);
156 return main_instance;
157 }
158
159 // Creates the initial Thread, and sets it to running.
160 static void create_initial_thread(Handle thread_group, JavaThread* thread,
161 TRAPS) {
162 InstanceKlass* ik = vmClasses::Thread_klass();
163 assert(ik->is_initialized(), "must be");
164 instanceHandle thread_oop = ik->allocate_instance_handle(CHECK);
165
166 // Cannot use JavaCalls::construct_new_instance because the java.lang.Thread
167 // constructor calls Thread.current(), which must be set here for the
168 // initial thread.
169 java_lang_Thread::set_thread(thread_oop(), thread);
170 thread->set_threadOopHandles(thread_oop());
171
172 Handle string = java_lang_String::create_from_str("main", CHECK);
173
174 JavaValue result(T_VOID);
175 JavaCalls::call_special(&result, thread_oop,
176 ik,
177 vmSymbols::object_initializer_name(),
178 vmSymbols::threadgroup_string_void_signature(),
179 thread_group,
180 string,
181 CHECK);
182
183 DEBUG_ONLY(int64_t main_thread_tid = java_lang_Thread::thread_id(thread_oop());)
184 assert(main_thread_tid == ThreadIdentifier::initial(), "");
185 assert(main_thread_tid == thread->monitor_owner_id(), "");
186 JFR_ONLY(assert(JFR_JVM_THREAD_ID(thread) == static_cast<traceid>(main_thread_tid), "initial tid mismatch");)
187
188 // Set thread status to running since main thread has
189 // been started and running.
190 java_lang_Thread::set_thread_status(thread_oop(),
191 JavaThreadStatus::RUNNABLE);
192 }
193
194 // Extract version and vendor specific information from
195 // java.lang.VersionProps fields.
196 // Returned char* is allocated in the thread's resource area
197 // so must be copied for permanency.
198 static const char* get_java_version_info(InstanceKlass* ik,
199 Symbol* field_name) {
200 fieldDescriptor fd;
201 bool found = ik != nullptr &&
202 ik->find_local_field(field_name,
203 vmSymbols::string_signature(), &fd);
204 if (found) {
205 oop name_oop = ik->java_mirror()->obj_field(fd.offset());
206 if (name_oop == nullptr) {
207 return nullptr;
208 }
209 const char* name = java_lang_String::as_utf8_string(name_oop);
210 return name;
211 } else {
212 return nullptr;
213 }
214 }
215
216 // ======= Threads ========
217
218 // The Threads class links together all active threads, and provides
219 // operations over all threads. It is protected by the Threads_lock,
220 // which is also used in other global contexts like safepointing.
221 // ThreadsListHandles are used to safely perform operations on one
222 // or more threads without the risk of the thread exiting during the
223 // operation.
224 //
225 // Note: The Threads_lock is currently more widely used than we
226 // would like. We are actively migrating Threads_lock uses to other
227 // mechanisms in order to reduce Threads_lock contention.
228
229 int Threads::_number_of_threads = 0;
230 int Threads::_number_of_non_daemon_threads = 0;
231 int Threads::_return_code = 0;
232 uintx Threads::_thread_claim_token = 1; // Never zero.
233
234 #ifdef ASSERT
235 bool Threads::_vm_complete = false;
236 #endif
237
238 // General purpose hook into Java code, run once when the VM is initialized.
239 // The Java library method itself may be changed independently from the VM.
240 static void call_postVMInitHook(TRAPS) {
241 Klass* klass = SystemDictionary::resolve_or_null(vmSymbols::jdk_internal_vm_PostVMInitHook(), THREAD);
242 if (klass != nullptr) {
243 JavaValue result(T_VOID);
244 JavaCalls::call_static(&result, klass, vmSymbols::run_method_name(),
245 vmSymbols::void_method_signature(),
246 CHECK);
247 }
248 }
249
250 // All NonJavaThreads (i.e., every non-JavaThread in the system).
251 void Threads::non_java_threads_do(ThreadClosure* tc) {
252 NoSafepointVerifier nsv;
253 for (NonJavaThread::Iterator njti; !njti.end(); njti.step()) {
254 tc->do_thread(njti.current());
255 }
256 }
257
258 // All JavaThreads
259 #define ALL_JAVA_THREADS(X) \
260 for (JavaThread* X : *ThreadsSMRSupport::get_java_thread_list())
261
262 // All JavaThreads
263 void Threads::java_threads_do(ThreadClosure* tc) {
264 assert_locked_or_safepoint(Threads_lock);
265 // ALL_JAVA_THREADS iterates through all JavaThreads.
266 ALL_JAVA_THREADS(p) {
267 tc->do_thread(p);
268 }
269 }
270
271 // All JavaThreads + all non-JavaThreads (i.e., every thread in the system).
272 void Threads::threads_do(ThreadClosure* tc) {
273 assert_locked_or_safepoint(Threads_lock);
274 java_threads_do(tc);
275 non_java_threads_do(tc);
276 }
277
278 void Threads::possibly_parallel_threads_do(bool is_par, ThreadClosure* tc) {
279 assert_at_safepoint();
280
281 uintx claim_token = Threads::thread_claim_token();
282 ALL_JAVA_THREADS(p) {
283 if (p->claim_threads_do(is_par, claim_token)) {
284 tc->do_thread(p);
285 }
286 }
287 for (NonJavaThread::Iterator njti; !njti.end(); njti.step()) {
288 Thread* current = njti.current();
289 if (current->claim_threads_do(is_par, claim_token)) {
290 tc->do_thread(current);
291 }
292 }
293 }
294
295 // The system initialization in the library has three phases.
296 //
297 // Phase 1: java.lang.System class initialization
298 // java.lang.System is a primordial class loaded and initialized
299 // by the VM early during startup. java.lang.System.<clinit>
300 // only does registerNatives and keeps the rest of the class
301 // initialization work later until thread initialization completes.
302 //
303 // System.initPhase1 initializes the system properties, the static
304 // fields in, out, and err. Set up java signal handlers, OS-specific
305 // system settings, and thread group of the main thread.
306 static void call_initPhase1(TRAPS) {
307 Klass* klass = vmClasses::System_klass();
308 JavaValue result(T_VOID);
309 JavaCalls::call_static(&result, klass, vmSymbols::initPhase1_name(),
310 vmSymbols::void_method_signature(), CHECK);
311 }
312
313 // Phase 2. Module system initialization
314 // This will initialize the module system. Only java.base classes
315 // can be loaded until phase 2 completes.
316 //
317 // Call System.initPhase2 after the compiler initialization and jsr292
318 // classes get initialized because module initialization runs a lot of java
319 // code, that for performance reasons, should be compiled. Also, this will
320 // enable the startup code to use lambda and other language features in this
321 // phase and onward.
322 //
323 // After phase 2, The VM will begin search classes from -Xbootclasspath/a.
324 static void call_initPhase2(TRAPS) {
325 TraceTime timer("Initialize module system", TRACETIME_LOG(Info, startuptime));
326
327 Klass* klass = vmClasses::System_klass();
328
329 JavaValue result(T_INT);
330 JavaCallArguments args;
331 args.push_int(DisplayVMOutputToStderr);
332 args.push_int(log_is_enabled(Debug, init)); // print stack trace if exception thrown
333 JavaCalls::call_static(&result, klass, vmSymbols::initPhase2_name(),
334 vmSymbols::boolean_boolean_int_signature(), &args, CHECK);
335 if (result.get_jint() != JNI_OK) {
336 vm_exit_during_initialization(); // no message or exception
337 }
338
339 universe_post_module_init();
340 }
341
342 // Phase 3. final setup - set security manager, system class loader and TCCL
343 //
344 // This will instantiate and set the security manager, set the system class
345 // loader as well as the thread context class loader. The security manager
346 // and system class loader may be a custom class loaded from -Xbootclasspath/a,
347 // other modules or the application's classpath.
348 static void call_initPhase3(TRAPS) {
349 Klass* klass = vmClasses::System_klass();
350 JavaValue result(T_VOID);
351 JavaCalls::call_static(&result, klass, vmSymbols::initPhase3_name(),
352 vmSymbols::void_method_signature(), CHECK);
353 }
354
355 void Threads::initialize_java_lang_classes(JavaThread* main_thread, TRAPS) {
356 TraceTime timer("Initialize java.lang classes", TRACETIME_LOG(Info, startuptime));
357
358 // This is before the execution of the very first Java bytecode.
359 if (CDSConfig::is_using_aot_linked_classes()) {
360 AOTLinkedClassBulkLoader::link_classes(THREAD);
361 }
362
363 initialize_class(vmSymbols::java_lang_String(), CHECK);
364
365 // Inject CompactStrings value after the static initializers for String ran.
366 java_lang_String::set_compact_strings(CompactStrings);
367
368 // Initialize java_lang.System (needed before creating the thread)
369 initialize_class(vmSymbols::java_lang_System(), CHECK);
370 // The VM creates & returns objects of this class. Make sure it's initialized.
371 initialize_class(vmSymbols::java_lang_Class(), CHECK);
372
373 initialize_class(vmSymbols::java_lang_ThreadGroup(), CHECK);
374 Handle thread_group = create_initial_thread_group(CHECK);
375 Universe::set_main_thread_group(thread_group());
376 initialize_class(vmSymbols::java_lang_Thread(), CHECK);
377 create_initial_thread(thread_group, main_thread, CHECK);
378
379 HeapShared::init_box_classes(CHECK);
380
381 // The VM creates objects of this class.
382 initialize_class(vmSymbols::java_lang_Module(), CHECK);
383
384 #ifdef ASSERT
385 InstanceKlass *k = vmClasses::UnsafeConstants_klass();
386 assert(k->is_not_initialized(), "UnsafeConstants should not already be initialized");
387 #endif
388
389 // initialize the hardware-specific constants needed by Unsafe
390 initialize_class(vmSymbols::jdk_internal_misc_UnsafeConstants(), CHECK);
391 jdk_internal_misc_UnsafeConstants::set_unsafe_constants();
392
393 // The VM preresolves methods to these classes. Make sure that they get initialized
394 initialize_class(vmSymbols::java_lang_reflect_Method(), CHECK);
395 initialize_class(vmSymbols::java_lang_ref_Finalizer(), CHECK);
396
397 if (CDSConfig::is_using_aot_linked_classes()) {
398 // This is necessary for reflection to work in early core lib bootstrap code.
399 vmClasses::reflect_AccessibleObject_klass()->link_class(CHECK);
400 vmClasses::reflect_Field_klass()->link_class(CHECK);
401 vmClasses::reflect_Parameter_klass()->link_class(CHECK);
402 vmClasses::reflect_Method_klass()->link_class(CHECK);
403 vmClasses::reflect_Constructor_klass()->link_class(CHECK);
404 }
405
406 HeapShared::materialize_thread_object();
407
408 // Phase 1 of the system initialization in the library, java.lang.System class initialization
409 call_initPhase1(CHECK);
410
411 // Get the Java runtime name, version, and vendor info after java.lang.System is initialized.
412 // Some values are actually configure-time constants but some can be set via the jlink tool and
413 // so must be read dynamically. We treat them all the same.
414 InstanceKlass* ik = SystemDictionary::find_instance_klass(THREAD, vmSymbols::java_lang_VersionProps(),
415 Handle());
416 {
417 ResourceMark rm(main_thread);
418 JDK_Version::set_java_version(get_java_version_info(ik, vmSymbols::java_version_name()));
419
420 JDK_Version::set_runtime_name(get_java_version_info(ik, vmSymbols::java_runtime_name_name()));
421
422 JDK_Version::set_runtime_version(get_java_version_info(ik, vmSymbols::java_runtime_version_name()));
423
424 JDK_Version::set_runtime_vendor_version(get_java_version_info(ik, vmSymbols::java_runtime_vendor_version_name()));
425
426 JDK_Version::set_runtime_vendor_vm_bug_url(get_java_version_info(ik, vmSymbols::java_runtime_vendor_vm_bug_url_name()));
427 }
428
429 // an instance of OutOfMemory exception has been allocated earlier
430 initialize_class(vmSymbols::java_lang_OutOfMemoryError(), CHECK);
431 initialize_class(vmSymbols::java_lang_NullPointerException(), CHECK);
432 initialize_class(vmSymbols::java_lang_ClassCastException(), CHECK);
433 initialize_class(vmSymbols::java_lang_ArrayStoreException(), CHECK);
434 initialize_class(vmSymbols::java_lang_ArithmeticException(), CHECK);
435 initialize_class(vmSymbols::jdk_internal_vm_PreemptedException(), CHECK);
436 initialize_class(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), CHECK);
437 initialize_class(vmSymbols::java_lang_StackOverflowError(), CHECK);
438 initialize_class(vmSymbols::java_lang_IllegalMonitorStateException(), CHECK);
439 initialize_class(vmSymbols::java_lang_IllegalArgumentException(), CHECK);
440 initialize_class(vmSymbols::java_lang_InternalError(), CHECK);
441 }
442
443 bool Threads::initialize_compilation(TRAPS) {
444 // initialize compiler(s)
445 bool force_JVMCI_initialization = false;
446
447 #if defined(COMPILER1) || COMPILER2_OR_JVMCI
448 bool init_compilation = true;
449 #if INCLUDE_JVMCI
450 if (EnableJVMCI) {
451 // Initialize JVMCI eagerly when it is explicitly requested.
452 // Or when JVMCILibDumpJNIConfig or JVMCIPrintProperties is enabled.
453 force_JVMCI_initialization = EagerJVMCI || JVMCIPrintProperties || JVMCILibDumpJNIConfig;
454 if (!force_JVMCI_initialization && UseJVMCICompiler && !UseJVMCINativeLibrary && (!UseInterpreter || !BackgroundCompilation)) {
455 // Force initialization of jarjvmci otherwise requests for blocking
456 // compilations will not actually block until jarjvmci is initialized.
457 force_JVMCI_initialization = true;
458 }
459 if (JVMCIPrintProperties || JVMCILibDumpJNIConfig) {
460 // Both JVMCILibDumpJNIConfig and JVMCIPrintProperties exit the VM
461 // so compilation should be disabled. This prevents dumping or
462 // printing from happening more than once.
463 init_compilation = false;
464 }
465 }
466 #endif
467 if (init_compilation) {
468 CompileBroker::compilation_init(CHECK_false);
469 }
470 #endif
471
472 return force_JVMCI_initialization;
473 }
474
475 void Threads::initialize_jsr292_core_classes(TRAPS) {
476 TraceTime timer("Initialize java.lang.invoke classes", TRACETIME_LOG(Info, startuptime));
477
478 initialize_class(vmSymbols::java_lang_invoke_MethodHandle(), CHECK);
479 initialize_class(vmSymbols::java_lang_invoke_ResolvedMethodName(), CHECK);
480 initialize_class(vmSymbols::java_lang_invoke_MemberName(), CHECK);
481 initialize_class(vmSymbols::java_lang_invoke_MethodHandleNatives(), CHECK);
482
483 if (UseSharedSpaces) {
484 HeapShared::initialize_java_lang_invoke(CHECK);
485 }
486 }
487
488 // One-shot PeriodicTask subclass for reading the release file
489 class ReadReleaseFileTask : public PeriodicTask {
490 public:
491 ReadReleaseFileTask() : PeriodicTask(100) {}
492
493 virtual void task() {
494 os::read_image_release_file();
495
496 // Reclaim our storage and disenroll ourself.
497 delete this;
498 }
499 };
500
501 jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) {
502 extern void JDK_Version_init();
503
504 // Preinitialize version info.
505 VM_Version::early_initialize();
506
507 // Check version
508 if (!is_supported_jni_version(args->version)) return JNI_EVERSION;
509
510 // Deferred "static" initialization
511 NonJavaThread::init();
512
513 // Initialize library-based TLS
514 ThreadLocalStorage::init();
515
516 // Initialize the output stream module
517 ostream_init();
518
519 // Process java launcher properties.
520 Arguments::process_sun_java_launcher_properties(args);
521
522 // Initialize the os module
523 os::init();
524
525 // Initialize memory pools
526 Arena::initialize_chunk_pool();
527
528 MACOS_AARCH64_ONLY(os::current_thread_enable_wx(WXWrite));
529
530 // Record VM creation timing statistics
531 TraceVmCreationTime create_vm_timer;
532 create_vm_timer.start();
533
534 // Initialize system properties.
535 Arguments::init_system_properties();
536
537 // So that JDK version can be used as a discriminator when parsing arguments
538 JDK_Version_init();
539
540 // Update/Initialize System properties after JDK version number is known
541 Arguments::init_version_specific_system_properties();
542
543 // Make sure to initialize log configuration *before* parsing arguments
544 LogConfiguration::initialize(create_vm_timer.begin_time());
545
546 // Parse arguments
547 // Note: this internally calls os::init_container_support()
548 jint parse_result = Arguments::parse(args);
549 if (parse_result != JNI_OK) return parse_result;
550
551 // Initialize NMT right after argument parsing to keep the pre-NMT-init window small.
552 MemTracker::initialize();
553
554 os::init_before_ergo();
555
556 jint ergo_result = Arguments::apply_ergo();
557 if (ergo_result != JNI_OK) return ergo_result;
558
559 // Final check of all ranges after ergonomics which may change values.
560 if (!JVMFlagLimit::check_all_ranges()) {
561 return JNI_EINVAL;
562 }
563
564 // Final check of all 'AfterErgo' constraints after ergonomics which may change values.
565 bool constraint_result = JVMFlagLimit::check_all_constraints(JVMFlagConstraintPhase::AfterErgo);
566 if (!constraint_result) {
567 return JNI_EINVAL;
568 }
569
570 if (PauseAtStartup) {
571 os::pause();
572 }
573
574 HOTSPOT_VM_INIT_BEGIN();
575
576 // Timing (must come after argument parsing)
577 TraceTime timer("Create VM", TRACETIME_LOG(Info, startuptime));
578
579 // Initialize the os module after parsing the args
580 jint os_init_2_result = os::init_2();
581 if (os_init_2_result != JNI_OK) return os_init_2_result;
582
583 #ifdef CAN_SHOW_REGISTERS_ON_ASSERT
584 // Initialize assert poison page mechanism.
585 if (ShowRegistersOnAssert) {
586 initialize_assert_poison();
587 }
588 #endif // CAN_SHOW_REGISTERS_ON_ASSERT
589
590 SafepointMechanism::initialize();
591
592 jint adjust_after_os_result = Arguments::adjust_after_os();
593 if (adjust_after_os_result != JNI_OK) return adjust_after_os_result;
594
595 // Initialize output stream logging
596 ostream_init_log();
597
598 // Launch -agentlib/-agentpath and converted -Xrun agents
599 JvmtiAgentList::load_agents();
600
601 // Initialize Threads state
602 _number_of_threads = 0;
603 _number_of_non_daemon_threads = 0;
604
605 // Initialize global data structures and create system classes in heap
606 vm_init_globals();
607
608 #if INCLUDE_JVMCI
609 if (JVMCICounterSize > 0) {
610 JavaThread::_jvmci_old_thread_counters = NEW_C_HEAP_ARRAY(jlong, JVMCICounterSize, mtJVMCI);
611 memset(JavaThread::_jvmci_old_thread_counters, 0, sizeof(jlong) * JVMCICounterSize);
612 } else {
613 JavaThread::_jvmci_old_thread_counters = nullptr;
614 }
615 #endif // INCLUDE_JVMCI
616
617 // Initialize OopStorage for threadObj
618 JavaThread::_thread_oop_storage = OopStorageSet::create_strong("Thread OopStorage", mtThread);
619
620 // Attach the main thread to this os thread. It is added to the threads list inside
621 // universe_init(), within init_globals().
622 JavaThread* main_thread = new JavaThread();
623 main_thread->set_thread_state(_thread_in_vm);
624 main_thread->initialize_thread_current();
625 // Once mutexes and main_thread are ready, we can use NmtVirtualMemoryLocker.
626 MemTracker::NmtVirtualMemoryLocker::set_safe_to_use();
627 // must do this before set_active_handles
628 main_thread->record_stack_base_and_size();
629 main_thread->register_thread_stack_with_NMT();
630 main_thread->set_active_handles(JNIHandleBlock::allocate_block());
631 MACOS_AARCH64_ONLY(main_thread->init_wx());
632
633 MutexLockerImpl::init_counters(); // depends on mutex_init(), perfMemory_init(), and Thread::initialize_thread_current().
634
635 // Set the _monitor_owner_id now since we will run Java code before the Thread instance
636 // is even created. The same value will be assigned to the Thread instance on init.
637 const int64_t main_thread_tid = ThreadIdentifier::next();
638 guarantee(main_thread_tid == 3, "Must equal the PRIMORDIAL_TID used in Threads.java");
639 main_thread->set_monitor_owner_id(main_thread_tid);
640
641 if (!Thread::set_as_starting_thread(main_thread)) {
642 vm_shutdown_during_initialization(
643 "Failed necessary internal allocation. Out of swap space");
644 main_thread->smr_delete();
645 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
646 return JNI_ENOMEM;
647 }
648
649 JFR_ONLY(Jfr::initialize_main_thread(main_thread);)
650
651 // Enable guard page *after* os::create_main_thread(), otherwise it would
652 // crash Linux VM, see notes in os_linux.cpp.
653 main_thread->stack_overflow_state()->create_stack_guard_pages();
654
655 // Initialize Java-Level synchronization subsystem
656 ObjectMonitor::Initialize();
657 ObjectSynchronizer::initialize();
658
659 Deoptimization::init_counters();
660 VMThread::init_counters();
661
662 // Initialize global modules
663 jint status = init_globals();
664 if (status != JNI_OK) {
665 main_thread->smr_delete();
666 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
667 return status;
668 }
669 if (xtty != nullptr)
670 xtty->elem("vm_main_thread thread='%zu'",
671 (uintx) main_thread->osthread()->thread_id());
672
673 // Have the WatcherThread read the release file in the background.
674 ReadReleaseFileTask* read_task = new ReadReleaseFileTask();
675 read_task->enroll();
676
677 // Create WatcherThread as soon as we can since we need it in case
678 // of hangs during error reporting.
679 WatcherThread::start();
680
681 status = init_globals2();
682 if (status != JNI_OK) {
683 Threads::remove(main_thread, false);
684 // It is possible that we managed to fully initialize Universe but have then
685 // failed by throwing an exception. In that case our caller JNI_CreateJavaVM
686 // will want to report it, so we can't delete the main thread.
687 if (!main_thread->has_pending_exception()) {
688 main_thread->smr_delete();
689 }
690 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
691 return status;
692 }
693
694 ObjectMonitor::Initialize2();
695
696 JFR_ONLY(Jfr::on_create_vm_1();)
697
698 // Should be done after the heap is fully created
699 main_thread->cache_global_variables();
700
701 // Any JVMTI raw monitors entered in onload will transition into
702 // real raw monitor. VM is setup enough here for raw monitor enter.
703 JvmtiExport::transition_pending_onload_raw_monitors();
704
705 // Create the VMThread
706 { TraceTime timer("Start VMThread", TRACETIME_LOG(Info, startuptime));
707
708 VMThread::create();
709 VMThread* vmthread = VMThread::vm_thread();
710
711 if (!os::create_thread(vmthread, os::vm_thread)) {
712 vm_exit_during_initialization("Cannot create VM thread. "
713 "Out of system resources.");
714 }
715
716 // Wait for the VM thread to become ready, and VMThread::run to initialize
717 // Monitors can have spurious returns, must always check another state flag
718 {
719 MonitorLocker ml(Notify_lock);
720 os::start_thread(vmthread);
721 while (!vmthread->is_running()) {
722 ml.wait();
723 }
724 }
725 }
726
727 assert(Universe::is_fully_initialized(), "not initialized");
728 if (VerifyDuringStartup) {
729 // Make sure we're starting with a clean slate.
730 VM_Verify verify_op;
731 VMThread::execute(&verify_op);
732 }
733
734 // We need this to update the java.vm.info property in case any flags used
735 // to initially define it have been changed. This is needed for both CDS
736 // since UseSharedSpaces may be changed after java.vm.info
737 // is initially computed. See Abstract_VM_Version::vm_info_string().
738 // This update must happen before we initialize the java classes, but
739 // after any initialization logic that might modify the flags.
740 Arguments::update_vm_info_property(VM_Version::vm_info_string());
741
742 JavaThread* THREAD = JavaThread::current(); // For exception macros.
743 HandleMark hm(THREAD);
744
745 // Always call even when there are not JVMTI environments yet, since environments
746 // may be attached late and JVMTI must track phases of VM execution
747 JvmtiExport::enter_early_start_phase();
748
749 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
750 JvmtiExport::post_early_vm_start();
751
752 // Launch -Xrun agents early if EagerXrunInit is set
753 if (EagerXrunInit) {
754 JvmtiAgentList::load_xrun_agents();
755 }
756
757 initialize_java_lang_classes(main_thread, CHECK_JNI_ERR);
758
759 quicken_jni_functions();
760
761 // No more stub generation allowed after that point.
762 StubCodeDesc::freeze();
763
764 // Prepare AOT heap loader for GC.
765 HeapShared::enable_gc();
766
767 #ifdef ADDRESS_SANITIZER
768 Asan::initialize();
769 #endif
770
771 // Set flag that basic initialization has completed. Used by exceptions and various
772 // debug stuff, that does not work until all basic classes have been initialized.
773 set_init_completed();
774
775 LogConfiguration::post_initialize();
776 Metaspace::post_initialize();
777 MutexLockerImpl::post_initialize();
778
779 HOTSPOT_VM_INIT_END();
780
781 // record VM initialization completion time
782 #if INCLUDE_MANAGEMENT
783 Management::record_vm_init_completed();
784 #endif // INCLUDE_MANAGEMENT
785
786 log_info(os)("Initialized VM with process ID %d", os::current_process_id());
787
788 if (!FLAG_IS_DEFAULT(CreateCoredumpOnCrash) && CreateCoredumpOnCrash) {
789 char buffer[2*JVM_MAXPATHLEN];
790 os::check_core_dump_prerequisites(buffer, sizeof(buffer), true);
791 }
792
793 // Signal Dispatcher needs to be started before VMInit event is posted
794 os::initialize_jdk_signal_support(CHECK_JNI_ERR);
795
796 // Start Attach Listener if +StartAttachListener or it can't be started lazily
797 if (!DisableAttachMechanism) {
798 AttachListener::vm_start();
799 if (StartAttachListener || AttachListener::init_at_startup()) {
800 AttachListener::init();
801 }
802 }
803
804 // Launch -Xrun agents if EagerXrunInit is not set.
805 if (!EagerXrunInit) {
806 JvmtiAgentList::load_xrun_agents();
807 }
808
809 Arena::start_chunk_pool_cleaner_task();
810
811 // Start the service thread
812 // The service thread enqueues JVMTI deferred events and does various hashtable
813 // and other cleanups. Needs to start before the compilers start posting events.
814 ServiceThread::initialize();
815
816 if (CDSConfig::is_using_aot_linked_classes()) {
817 nmethod::post_delayed_compiled_method_load_events();
818 }
819
820 // Start the monitor deflation thread:
821 MonitorDeflationThread::initialize();
822
823 #if INCLUDE_CDS
824 // Start the method sampler
825 MethodProfiler::initialize();
826 #endif
827
828 bool force_JVMCI_initialization = initialize_compilation(CHECK_JNI_ERR);
829
830 if (CDSConfig::is_using_aot_linked_classes()) {
831 SystemDictionary::restore_archived_method_handle_intrinsics();
832 AOTLinkedClassBulkLoader::init_javabase_classes(THREAD);
833 }
834
835 // Start string deduplication thread if requested.
836 if (StringDedup::is_enabled()) {
837 StringDedup::start();
838 }
839
840 // Pre-initialize some JSR292 core classes to avoid deadlock during class loading.
841 // It is done after compilers are initialized, because otherwise compilations of
842 // signature polymorphic MH intrinsics can be missed
843 // (see SystemDictionary::find_method_handle_intrinsic).
844 initialize_jsr292_core_classes(CHECK_JNI_ERR);
845
846 // This will initialize the module system. Only java.base classes can be
847 // loaded until phase 2 completes
848 call_initPhase2(CHECK_JNI_ERR);
849
850 if (CDSConfig::is_using_aot_linked_classes()) {
851 AOTLinkedClassBulkLoader::init_non_javabase_classes(THREAD);
852 }
853 #ifndef PRODUCT
854 HeapShared::initialize_test_class_from_archive(THREAD);
855 #endif
856
857 JFR_ONLY(Jfr::on_create_vm_2();)
858
859 // Always call even when there are not JVMTI environments yet, since environments
860 // may be attached late and JVMTI must track phases of VM execution
861 JvmtiExport::enter_start_phase();
862
863 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
864 JvmtiExport::post_vm_start();
865
866 // Final system initialization including security manager and system class loader
867 call_initPhase3(CHECK_JNI_ERR);
868
869 // cache the system and platform class loaders
870 SystemDictionary::compute_java_loaders(CHECK_JNI_ERR);
871
872 // Initiate replay training processing once preloading is over.
873 CompileBroker::init_training_replay();
874
875 AOTLinkedClassBulkLoader::replay_training_at_init_for_preloaded_classes(CHECK_JNI_ERR);
876
877 if (Continuations::enabled()) {
878 // Initialize Continuation class now so that failure to create enterSpecial/doYield
879 // special nmethods due to limited CodeCache size can be treated as a fatal error at
880 // startup with the proper message that CodeCache size is too small.
881 initialize_class(vmSymbols::jdk_internal_vm_Continuation(), CHECK_JNI_ERR);
882 }
883
884 #if INCLUDE_CDS
885 if (PrecompileCode) {
886 Precompiler::compile_aot_code(CHECK_JNI_ERR);
887 if (PrecompileOnlyAndExit) {
888 AOTCodeCache::close();
889 log_vm_init_stats();
890 vm_direct_exit(0, "Code precompiation is over");
891 }
892 }
893 #endif
894
895 #if defined(COMPILER2)
896 // Pre-load cached compiled methods
897 AOTCodeCache::preload_code(CHECK_JNI_ERR);
898 #endif
899
900 if (NativeHeapTrimmer::enabled()) {
901 NativeHeapTrimmer::initialize();
902 }
903
904 // Always call even when there are not JVMTI environments yet, since environments
905 // may be attached late and JVMTI must track phases of VM execution
906 JvmtiExport::enter_live_phase();
907
908 // Make perfmemory accessible
909 PerfMemory::set_accessible(true);
910
911 // Notify JVMTI agents that VM initialization is complete - nop if no agents.
912 JvmtiExport::post_vm_initialized();
913
914 #if INCLUDE_JVMCI
915 if (force_JVMCI_initialization) {
916 JVMCI::initialize_compiler_in_create_vm(CHECK_JNI_ERR);
917 }
918 #endif
919
920 JFR_ONLY(Jfr::on_create_vm_3();)
921
922 #if INCLUDE_MANAGEMENT
923 bool start_agent = true;
924 #if INCLUDE_CDS
925 start_agent = !CDSConfig::is_dumping_final_static_archive();
926 if (!start_agent) {
927 log_info(aot)("Not starting management agent during creation of AOT cache.");
928 }
929 #endif // INCLUDE_CDS
930 if (start_agent) {
931 Management::initialize(THREAD);
932
933 if (HAS_PENDING_EXCEPTION) {
934 // management agent fails to start possibly due to
935 // configuration problem and is responsible for printing
936 // stack trace if appropriate. Simply exit VM.
937 vm_exit(1);
938 }
939 }
940 #endif // INCLUDE_MANAGEMENT
941
942 if (UsePerfData) PerfDataManager::create_misc_perfdata();
943 if (CheckJNICalls) JniPeriodicChecker::engage();
944
945 call_postVMInitHook(THREAD);
946 // The Java side of PostVMInitHook.run must deal with all
947 // exceptions and provide means of diagnosis.
948 if (HAS_PENDING_EXCEPTION) {
949 CLEAR_PENDING_EXCEPTION;
950 }
951
952 // Let WatcherThread run all registered periodic tasks now.
953 // NOTE: All PeriodicTasks should be registered by now. If they
954 // aren't, late joiners might appear to start slowly (we might
955 // take a while to process their first tick).
956 WatcherThread::run_all_tasks();
957
958 // Finish materializing AOT objects
959 HeapShared::finish_materialize_objects();
960
961 create_vm_timer.end();
962 #ifdef ASSERT
963 _vm_complete = true;
964 #endif
965
966 if (CDSConfig::is_dumping_classic_static_archive()) {
967 // Classic -Xshare:dump, aka "old workflow"
968 AOTMetaspace::dump_static_archive(CHECK_JNI_ERR);
969 } else if (CDSConfig::is_dumping_final_static_archive()) {
970 tty->print_cr("Reading AOTConfiguration %s and writing AOTCache %s", AOTConfiguration, AOTCache);
971 AOTMetaspace::dump_static_archive(CHECK_JNI_ERR);
972 }
973
974 log_info(init)("At VM initialization completion:");
975 log_vm_init_stats();
976
977 if (UsePerfData) {
978 if (ProfileVMLocks) {
979 main_thread->set_profile_vm_locks(true);
980 }
981 if (ProfileVMCalls) {
982 main_thread->set_profile_vm_calls(true);
983 }
984 if (ProfileRuntimeCalls) {
985 main_thread->set_profile_rt_calls(true);
986 }
987 if (ProfileVMOps) {
988 main_thread->set_profile_vm_ops(true);
989 }
990 }
991
992 return JNI_OK;
993 }
994
995 // Threads::destroy_vm() is normally called from jni_DestroyJavaVM() when
996 // the program falls off the end of main(). Another VM exit path is through
997 // vm_exit(), when the program calls System.exit() to return a value, or when
998 // there is a serious error in VM.
999 // These two separate shutdown paths are not exactly the same, but they share
1000 // Shutdown.shutdown() at Java level and before_exit() and VM_Exit op at VM level.
1001 //
1002 // Shutdown sequence:
1003 // + Shutdown native memory tracking if it is on
1004 // + Wait until we are the last non-daemon thread to execute
1005 // <-- every thing is still working at this moment -->
1006 // + Call java.lang.Shutdown.shutdown(), which will invoke Java level
1007 // shutdown hooks
1008 // + Call before_exit(), prepare for VM exit
1009 // > run VM level shutdown hooks (they are registered through JVM_OnExit(),
1010 // currently the only user of this mechanism is File.deleteOnExit())
1011 // > stop watcher thread,
1012 // post thread end and vm death events to JVMTI,
1013 // stop signal thread
1014 // + Call JavaThread::exit(), it will:
1015 // > release JNI handle blocks, remove stack guard pages
1016 // > remove this thread from Threads list
1017 // <-- no more Java code from this thread after this point -->
1018 // + Stop VM thread, it will bring the remaining VM to a safepoint and stop
1019 // the compiler threads at safepoint
1020 // <-- do not use anything that could get blocked by Safepoint -->
1021 // + Disable tracing at JNI/JVM barriers
1022 // + Set _vm_exited flag for threads that are still running native code
1023 // + Call exit_globals()
1024 // > deletes tty
1025 // > deletes PerfMemory resources
1026 // + Delete this thread
1027 // + Return to caller
1028
1029 void Threads::destroy_vm() {
1030 JavaThread* thread = JavaThread::current();
1031
1032 #ifdef ASSERT
1033 _vm_complete = false;
1034 #endif
1035 // Wait until we are the last non-daemon thread to execute, or
1036 // if we are a daemon then wait until the last non-daemon thread has
1037 // executed.
1038 bool daemon = java_lang_Thread::is_daemon(thread->threadObj());
1039 int expected = daemon ? 0 : 1;
1040 {
1041 MonitorLocker nu(Threads_lock);
1042 while (Threads::number_of_non_daemon_threads() > expected)
1043 // This wait should make safepoint checks, wait without a timeout.
1044 nu.wait(0);
1045 }
1046
1047 EventShutdown e;
1048 if (e.should_commit()) {
1049 e.set_reason("No remaining non-daemon Java threads");
1050 e.commit();
1051 }
1052
1053 // Hang forever on exit if we are reporting an error.
1054 if (ShowMessageBoxOnError && VMError::is_error_reported()) {
1055 os::infinite_sleep();
1056 }
1057 os::wait_for_keypress_at_exit();
1058
1059 // run Java level shutdown hooks
1060 thread->invoke_shutdown_hooks();
1061
1062 before_exit(thread);
1063
1064 thread->exit(true);
1065
1066 // We are no longer on the main thread list but could still be in a
1067 // secondary list where another thread may try to interact with us.
1068 // So wait until all such interactions are complete before we bring
1069 // the VM to the termination safepoint. Normally this would be done
1070 // using thread->smr_delete() below where we delete the thread, but
1071 // we can't call that after the termination safepoint is active as
1072 // we will deadlock on the Threads_lock. Once all interactions are
1073 // complete it is safe to directly delete the thread at any time.
1074 ThreadsSMRSupport::wait_until_not_protected(thread);
1075
1076 // Stop VM thread.
1077 {
1078 // 4945125 The vm thread comes to a safepoint during exit.
1079 // GC vm_operations can get caught at the safepoint, and the
1080 // heap is unparseable if they are caught. Grab the Heap_lock
1081 // to prevent this. The GC vm_operations will not be able to
1082 // queue until after the vm thread is dead. After this point,
1083 // we'll never emerge out of the safepoint before the VM exits.
1084 // Assert that the thread is terminated so that acquiring the
1085 // Heap_lock doesn't cause the terminated thread to participate in
1086 // the safepoint protocol.
1087
1088 assert(thread->is_terminated(), "must be terminated here");
1089 MutexLocker ml(Heap_lock);
1090
1091 VMThread::wait_for_vm_thread_exit();
1092 assert(SafepointSynchronize::is_at_safepoint(), "VM thread should exit at Safepoint");
1093 VMThread::destroy();
1094 }
1095
1096 // Now, all Java threads are gone except daemon threads. Daemon threads
1097 // running Java code or in VM are stopped by the Safepoint. However,
1098 // daemon threads executing native code are still running. But they
1099 // will be stopped at native=>Java/VM barriers. Note that we can't
1100 // simply kill or suspend them, as it is inherently deadlock-prone.
1101
1102 #if INCLUDE_CDS
1103 if (AOTVerifyTrainingData) {
1104 TrainingData::verify();
1105 }
1106 #endif
1107
1108 VM_Exit::set_vm_exited();
1109
1110 // Clean up ideal graph printers after the VMThread has started
1111 // the final safepoint which will block all the Compiler threads.
1112 // Note that this Thread has already logically exited so the
1113 // clean_up() function's use of a JavaThreadIteratorWithHandle
1114 // would be a problem except set_vm_exited() has remembered the
1115 // shutdown thread which is granted a policy exception.
1116 #if defined(COMPILER2) && !defined(PRODUCT)
1117 IdealGraphPrinter::clean_up();
1118 #endif
1119
1120 notify_vm_shutdown();
1121
1122 // exit_globals() will delete tty
1123 exit_globals();
1124
1125 // Deleting the shutdown thread here is safe. See comment on
1126 // wait_until_not_protected() above.
1127 delete thread;
1128
1129 #if INCLUDE_JVMCI
1130 if (JVMCICounterSize > 0) {
1131 FREE_C_HEAP_ARRAY(jlong, JavaThread::_jvmci_old_thread_counters);
1132 }
1133 #endif
1134
1135 LogConfiguration::finalize();
1136 }
1137
1138
1139 jboolean Threads::is_supported_jni_version_including_1_1(jint version) {
1140 if (version == JNI_VERSION_1_1) return JNI_TRUE;
1141 return is_supported_jni_version(version);
1142 }
1143
1144
1145 jboolean Threads::is_supported_jni_version(jint version) {
1146 if (version == JNI_VERSION_1_2) return JNI_TRUE;
1147 if (version == JNI_VERSION_1_4) return JNI_TRUE;
1148 if (version == JNI_VERSION_1_6) return JNI_TRUE;
1149 if (version == JNI_VERSION_1_8) return JNI_TRUE;
1150 if (version == JNI_VERSION_9) return JNI_TRUE;
1151 if (version == JNI_VERSION_10) return JNI_TRUE;
1152 if (version == JNI_VERSION_19) return JNI_TRUE;
1153 if (version == JNI_VERSION_20) return JNI_TRUE;
1154 if (version == JNI_VERSION_21) return JNI_TRUE;
1155 if (version == JNI_VERSION_24) return JNI_TRUE;
1156 return JNI_FALSE;
1157 }
1158
1159 void Threads::add(JavaThread* p, bool force_daemon) {
1160 // The threads lock must be owned at this point
1161 assert(Threads_lock->owned_by_self(), "must have threads lock");
1162 assert(p->monitor_owner_id() != 0, "should be set");
1163
1164 BarrierSet::barrier_set()->on_thread_attach(p);
1165
1166 // Once a JavaThread is added to the Threads list, smr_delete() has
1167 // to be used to delete it. Otherwise we can just delete it directly.
1168 p->set_on_thread_list();
1169
1170 _number_of_threads++;
1171 oop threadObj = p->threadObj();
1172 bool daemon = true;
1173 // Bootstrapping problem: threadObj can be null for initial
1174 // JavaThread (or for threads attached via JNI)
1175 if (!force_daemon &&
1176 (threadObj == nullptr || !java_lang_Thread::is_daemon(threadObj))) {
1177 _number_of_non_daemon_threads++;
1178 daemon = false;
1179 }
1180
1181 ThreadService::add_thread(p, daemon);
1182
1183 // Maintain fast thread list
1184 ThreadsSMRSupport::add_thread(p);
1185
1186 // Increase the ObjectMonitor ceiling for the new thread.
1187 ObjectSynchronizer::inc_in_use_list_ceiling();
1188
1189 // Possible GC point.
1190 Events::log(Thread::current(), "Thread added: " INTPTR_FORMAT, p2i(p));
1191
1192 // Make new thread known to active EscapeBarrier
1193 EscapeBarrier::thread_added(p);
1194 }
1195
1196 void Threads::remove(JavaThread* p, bool is_daemon) {
1197 // Extra scope needed for Thread_lock, so we can check
1198 // that we do not remove thread without safepoint code notice
1199 {
1200 ConditionalMutexLocker throttle_ml(ThreadsLockThrottle_lock, UseThreadsLockThrottleLock);
1201 MonitorLocker ml(Threads_lock);
1202
1203 if (ThreadIdTable::is_initialized()) {
1204 // This cleanup must be done before the current thread's GC barrier
1205 // is detached since we need to touch the threadObj oop.
1206 jlong tid = SharedRuntime::get_java_tid(p);
1207 ThreadIdTable::remove_thread(tid);
1208 }
1209
1210 // BarrierSet state must be destroyed after the last thread transition
1211 // before the thread terminates. Thread transitions result in calls to
1212 // StackWatermarkSet::on_safepoint(), which performs GC processing,
1213 // requiring the GC state to be alive.
1214 BarrierSet::barrier_set()->on_thread_detach(p);
1215 if (p->is_exiting()) {
1216 // If we got here via JavaThread::exit(), then we remember that the
1217 // thread's GC barrier has been detached. We don't do this when we get
1218 // here from another path, e.g., cleanup_failed_attach_current_thread().
1219 p->set_terminated(JavaThread::_thread_gc_barrier_detached);
1220 }
1221
1222 assert(ThreadsSMRSupport::get_java_thread_list()->includes(p), "p must be present");
1223
1224 // Maintain fast thread list
1225 ThreadsSMRSupport::remove_thread(p);
1226
1227 _number_of_threads--;
1228 if (!is_daemon) {
1229 _number_of_non_daemon_threads--;
1230
1231 // If this is the last non-daemon thread then we need to do
1232 // a notify on the Threads_lock so a thread waiting
1233 // on destroy_vm will wake up. But that thread could be a daemon
1234 // or non-daemon, so we notify for both the 0 and 1 case.
1235 if (number_of_non_daemon_threads() <= 1) {
1236 ml.notify_all();
1237 }
1238 }
1239 ThreadService::remove_thread(p, is_daemon);
1240
1241 // Make sure that safepoint code disregard this thread. This is needed since
1242 // the thread might mess around with locks after this point. This can cause it
1243 // to do callbacks into the safepoint code. However, the safepoint code is not aware
1244 // of this thread since it is removed from the queue.
1245 p->set_terminated(JavaThread::_thread_terminated);
1246
1247 // Notify threads waiting in EscapeBarriers
1248 EscapeBarrier::thread_removed(p);
1249 } // unlock Threads_lock and ThreadsLockThrottle_lock
1250
1251 // Reduce the ObjectMonitor ceiling for the exiting thread.
1252 ObjectSynchronizer::dec_in_use_list_ceiling();
1253
1254 // Since Events::log uses a lock, we grab it outside the Threads_lock
1255 Events::log(Thread::current(), "Thread exited: " INTPTR_FORMAT, p2i(p));
1256 }
1257
1258 // Operations on the Threads list for GC. These are not explicitly locked,
1259 // but the garbage collector must provide a safe context for them to run.
1260 // In particular, these things should never be called when the Threads_lock
1261 // is held by some other thread. (Note: the Safepoint abstraction also
1262 // uses the Threads_lock to guarantee this property. It also makes sure that
1263 // all threads gets blocked when exiting or starting).
1264
1265 void Threads::oops_do(OopClosure* f, NMethodClosure* cf) {
1266 ALL_JAVA_THREADS(p) {
1267 p->oops_do(f, cf);
1268 }
1269 VMThread::vm_thread()->oops_do(f, cf);
1270 }
1271
1272 void Threads::change_thread_claim_token() {
1273 if (++_thread_claim_token == 0) {
1274 // On overflow of the token counter, there is a risk of future
1275 // collisions between a new global token value and a stale token
1276 // for a thread, because not all iterations visit all threads.
1277 // (Though it's pretty much a theoretical concern for non-trivial
1278 // token counter sizes.) To deal with the possibility, reset all
1279 // the thread tokens to zero on global token overflow.
1280 struct ResetClaims : public ThreadClosure {
1281 virtual void do_thread(Thread* t) {
1282 t->claim_threads_do(false, 0);
1283 }
1284 } reset_claims;
1285 Threads::threads_do(&reset_claims);
1286 // On overflow, update the global token to non-zero, to
1287 // avoid the special "never claimed" initial thread value.
1288 _thread_claim_token = 1;
1289 }
1290 }
1291
1292 #ifdef ASSERT
1293 static void assert_thread_claimed(const char* kind, Thread* t, uintx expected) {
1294 const uintx token = t->threads_do_token();
1295 assert(token == expected,
1296 "%s " PTR_FORMAT " has incorrect value %zu != %zu",
1297 kind, p2i(t), token, expected);
1298 }
1299
1300 void Threads::assert_all_threads_claimed() {
1301 ALL_JAVA_THREADS(p) {
1302 assert_thread_claimed("JavaThread", p, _thread_claim_token);
1303 }
1304
1305 struct NJTClaimedVerifierClosure : public ThreadClosure {
1306 uintx _thread_claim_token;
1307
1308 NJTClaimedVerifierClosure(uintx thread_claim_token) : ThreadClosure(), _thread_claim_token(thread_claim_token) { }
1309
1310 virtual void do_thread(Thread* thread) override {
1311 assert_thread_claimed("Non-JavaThread", VMThread::vm_thread(), _thread_claim_token);
1312 }
1313 } tc(_thread_claim_token);
1314
1315 non_java_threads_do(&tc);
1316 }
1317 #endif // ASSERT
1318
1319 class ParallelOopsDoThreadClosure : public ThreadClosure {
1320 private:
1321 OopClosure* _f;
1322 NMethodClosure* _cf;
1323 public:
1324 ParallelOopsDoThreadClosure(OopClosure* f, NMethodClosure* cf) : _f(f), _cf(cf) {}
1325 void do_thread(Thread* t) {
1326 t->oops_do(_f, _cf);
1327 }
1328 };
1329
1330 void Threads::possibly_parallel_oops_do(bool is_par, OopClosure* f, NMethodClosure* cf) {
1331 ParallelOopsDoThreadClosure tc(f, cf);
1332 possibly_parallel_threads_do(is_par, &tc);
1333 }
1334
1335 void Threads::metadata_do(MetadataClosure* f) {
1336 ALL_JAVA_THREADS(p) {
1337 p->metadata_do(f);
1338 }
1339 }
1340
1341 class ThreadHandlesClosure : public ThreadClosure {
1342 void (*_f)(Metadata*);
1343 public:
1344 ThreadHandlesClosure(void f(Metadata*)) : _f(f) {}
1345 virtual void do_thread(Thread* thread) {
1346 thread->metadata_handles_do(_f);
1347 }
1348 };
1349
1350 void Threads::metadata_handles_do(void f(Metadata*)) {
1351 // Only walk the Handles in Thread.
1352 ThreadHandlesClosure handles_closure(f);
1353 threads_do(&handles_closure);
1354 }
1355
1356 #if INCLUDE_JVMTI
1357 // Get Java threads that are waiting to enter or re-enter the specified monitor.
1358 // Java threads that are executing mounted virtual threads are not included.
1359 GrowableArray<JavaThread*>* Threads::get_pending_threads(ThreadsList * t_list,
1360 int count,
1361 address monitor) {
1362 assert(Thread::current()->is_VM_thread(), "Must be the VM thread");
1363 GrowableArray<JavaThread*>* result = new GrowableArray<JavaThread*>(count);
1364
1365 int i = 0;
1366 for (JavaThread* p : *t_list) {
1367 if (!p->can_call_java()) continue;
1368
1369 oop thread_oop = JvmtiEnvBase::get_vthread_or_thread_oop(p);
1370 if (thread_oop->is_a(vmClasses::BaseVirtualThread_klass())) {
1371 continue;
1372 }
1373 // The first stage of async deflation does not affect any field
1374 // used by this comparison so the ObjectMonitor* is usable here.
1375 address pending = (address)p->current_pending_monitor();
1376 address waiting = (address)p->current_waiting_monitor();
1377 // do not include virtual threads to the list
1378 jint state = JvmtiEnvBase::get_thread_state(thread_oop, p);
1379 if (pending == monitor || (waiting == monitor &&
1380 (state & JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER))
1381 ) { // found a match
1382 if (i < count) result->append(p); // save the first count matches
1383 i++;
1384 }
1385 }
1386
1387 return result;
1388 }
1389 #endif // INCLUDE_JVMTI
1390
1391 JavaThread* Threads::owning_thread_from_object(ThreadsList * t_list, oop obj) {
1392 for (JavaThread* q : *t_list) {
1393 // Need to start processing before accessing oops in the thread.
1394 StackWatermark* watermark = StackWatermarkSet::get(q, StackWatermarkKind::gc);
1395 if (watermark != nullptr) {
1396 watermark->start_processing();
1397 }
1398
1399 if (q->lock_stack().contains(obj)) {
1400 return q;
1401 }
1402 }
1403 return nullptr;
1404 }
1405
1406 JavaThread* Threads::owning_thread_from_monitor(ThreadsList* t_list, ObjectMonitor* monitor) {
1407 if (monitor->has_anonymous_owner()) {
1408 return owning_thread_from_object(t_list, monitor->object());
1409 } else {
1410 JavaThread* the_owner = nullptr;
1411 for (JavaThread* q : *t_list) {
1412 if (monitor->has_owner(q)) {
1413 the_owner = q;
1414 break;
1415 }
1416 }
1417 return the_owner;
1418 }
1419 }
1420
1421 class PrintOnClosure : public ThreadClosure {
1422 private:
1423 outputStream* _st;
1424
1425 public:
1426 PrintOnClosure(outputStream* st) :
1427 _st(st) {}
1428
1429 virtual void do_thread(Thread* thread) {
1430 if (thread != nullptr) {
1431 thread->print_on(_st);
1432 _st->cr();
1433 }
1434 }
1435 };
1436
1437 // Threads::print_on() is called at safepoint by VM_PrintThreads operation.
1438 void Threads::print_on(outputStream* st, bool print_stacks,
1439 bool internal_format, bool print_concurrent_locks,
1440 bool print_extended_info) {
1441 char buf[32];
1442 st->print_raw_cr(os::local_time_string(buf, sizeof(buf)));
1443
1444 st->print_cr("Full thread dump %s (%s %s)",
1445 VM_Version::vm_name(),
1446 VM_Version::vm_release(),
1447 VM_Version::vm_info_string());
1448 JDK_Version::current().to_string(buf, sizeof(buf));
1449 const char* runtime_name = JDK_Version::runtime_name() != nullptr ?
1450 JDK_Version::runtime_name() : "";
1451 const char* runtime_version = JDK_Version::runtime_version() != nullptr ?
1452 JDK_Version::runtime_version() : "";
1453 const char* vendor_version = JDK_Version::runtime_vendor_version() != nullptr ?
1454 JDK_Version::runtime_vendor_version() : "";
1455 const char* jdk_debug_level = VM_Version::printable_jdk_debug_level() != nullptr ?
1456 VM_Version::printable_jdk_debug_level() : "";
1457
1458 st->print_cr(" JDK version: %s%s%s (%s) (%sbuild %s)", runtime_name,
1459 (*vendor_version != '\0') ? " " : "", vendor_version,
1460 buf, jdk_debug_level, runtime_version);
1461
1462 st->cr();
1463
1464 #if INCLUDE_SERVICES
1465 // Dump concurrent locks
1466 ConcurrentLocksDump concurrent_locks;
1467 if (print_concurrent_locks) {
1468 concurrent_locks.dump_at_safepoint();
1469 }
1470 #endif // INCLUDE_SERVICES
1471
1472 ThreadsSMRSupport::print_info_on(st);
1473 st->cr();
1474
1475 ALL_JAVA_THREADS(p) {
1476 ResourceMark rm;
1477 p->print_on(st, print_extended_info);
1478 if (print_stacks) {
1479 if (internal_format) {
1480 p->trace_stack();
1481 } else {
1482 p->print_stack_on(st);
1483 if (p->is_vthread_mounted()) {
1484 st->print_cr(" Mounted virtual thread #" INT64_FORMAT, java_lang_Thread::thread_id(p->vthread()));
1485 p->print_vthread_stack_on(st);
1486 }
1487 }
1488 }
1489 st->cr();
1490 #if INCLUDE_SERVICES
1491 if (print_concurrent_locks) {
1492 concurrent_locks.print_locks_on(p, st);
1493 }
1494 #endif // INCLUDE_SERVICES
1495 }
1496
1497 PrintOnClosure cl(st);
1498 non_java_threads_do(&cl);
1499
1500 st->flush();
1501 }
1502
1503 void Threads::print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
1504 int buflen, bool* found_current) {
1505 if (this_thread != nullptr) {
1506 bool is_current = (current == this_thread);
1507 *found_current = *found_current || is_current;
1508 st->print("%s", is_current ? "=>" : " ");
1509
1510 st->print(PTR_FORMAT, p2i(this_thread));
1511 st->print(" ");
1512 this_thread->print_on_error(st, buf, buflen);
1513 st->cr();
1514 }
1515 }
1516
1517 class PrintOnErrorClosure : public ThreadClosure {
1518 outputStream* _st;
1519 Thread* _current;
1520 char* _buf;
1521 int _buflen;
1522 bool* _found_current;
1523 unsigned _num_printed;
1524 public:
1525 PrintOnErrorClosure(outputStream* st, Thread* current, char* buf,
1526 int buflen, bool* found_current) :
1527 _st(st), _current(current), _buf(buf), _buflen(buflen), _found_current(found_current),
1528 _num_printed(0) {}
1529
1530 virtual void do_thread(Thread* thread) {
1531 _num_printed++;
1532 Threads::print_on_error(thread, _st, _current, _buf, _buflen, _found_current);
1533 }
1534
1535 unsigned num_printed() const { return _num_printed; }
1536 };
1537
1538 // Threads::print_on_error() is called by fatal error handler. It's possible
1539 // that VM is not at safepoint and/or current thread is inside signal handler.
1540 // Don't print stack trace, as the stack may not be walkable. Don't allocate
1541 // memory (even in resource area), it might deadlock the error handler.
1542 void Threads::print_on_error(outputStream* st, Thread* current, char* buf,
1543 int buflen) {
1544 ThreadsSMRSupport::print_info_on(st);
1545 st->cr();
1546
1547 bool found_current = false;
1548 st->print_cr("Java Threads: ( => current thread )");
1549 unsigned num_java = 0;
1550 ALL_JAVA_THREADS(thread) {
1551 print_on_error(thread, st, current, buf, buflen, &found_current);
1552 num_java++;
1553 }
1554 st->print_cr("Total: %u", num_java);
1555 st->cr();
1556
1557 st->print_cr("Other Threads:");
1558 unsigned num_other = ((VMThread::vm_thread() != nullptr) ? 1 : 0) +
1559 ((WatcherThread::watcher_thread() != nullptr) ? 1 : 0) +
1560 ((AsyncLogWriter::instance() != nullptr) ? 1 : 0);
1561 print_on_error(VMThread::vm_thread(), st, current, buf, buflen, &found_current);
1562 print_on_error(WatcherThread::watcher_thread(), st, current, buf, buflen, &found_current);
1563 print_on_error(AsyncLogWriter::instance(), st, current, buf, buflen, &found_current);
1564
1565 if (Universe::heap() != nullptr) {
1566 PrintOnErrorClosure print_closure(st, current, buf, buflen, &found_current);
1567 Universe::heap()->gc_threads_do(&print_closure);
1568 num_other += print_closure.num_printed();
1569 }
1570
1571 if (!found_current) {
1572 st->cr();
1573 st->print("=>" PTR_FORMAT " (exited) ", p2i(current));
1574 current->print_on_error(st, buf, buflen);
1575 num_other++;
1576 st->cr();
1577 }
1578 st->print_cr("Total: %u", num_other);
1579 st->cr();
1580
1581 st->print_cr("Threads with active compile tasks:");
1582 unsigned num = print_threads_compiling(st, buf, buflen);
1583 st->print_cr("Total: %u", num);
1584 }
1585
1586 unsigned Threads::print_threads_compiling(outputStream* st, char* buf, int buflen, bool short_form) {
1587 unsigned num = 0;
1588 ALL_JAVA_THREADS(thread) {
1589 if (thread->is_Compiler_thread()) {
1590 CompilerThread* ct = (CompilerThread*) thread;
1591
1592 // Keep task in local variable for null check.
1593 // ct->_task might be set to null by concurring compiler thread
1594 // because it completed the compilation. The task is never freed,
1595 // though, just returned to a free list.
1596 CompileTask* task = ct->task();
1597 if (task != nullptr) {
1598 thread->print_name_on_error(st, buf, buflen);
1599 st->print(" ");
1600 task->print(st, nullptr, short_form, true);
1601 num++;
1602 }
1603 }
1604 }
1605 return num;
1606 }
1607
1608 void Threads::verify() {
1609 ALL_JAVA_THREADS(p) {
1610 p->verify();
1611 }
1612 VMThread* thread = VMThread::vm_thread();
1613 if (thread != nullptr) thread->verify();
1614 }