1 /*
2 * Copyright (c) 1997, 2024, 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 "precompiled.hpp"
27 #include "cds/cds_globals.hpp"
28 #include "cds/cdsConfig.hpp"
29 #include "cds/metaspaceShared.hpp"
30 #include "classfile/classLoader.hpp"
31 #include "classfile/javaClasses.hpp"
32 #include "classfile/javaThreadStatus.hpp"
33 #include "classfile/systemDictionary.hpp"
34 #include "classfile/vmClasses.hpp"
35 #include "classfile/vmSymbols.hpp"
36 #include "compiler/compileBroker.hpp"
37 #include "compiler/compileTask.hpp"
38 #include "compiler/compilerThread.hpp"
39 #include "gc/shared/barrierSet.hpp"
40 #include "gc/shared/barrierSetNMethod.hpp"
41 #include "gc/shared/gcVMOperations.hpp"
42 #include "gc/shared/oopStorage.hpp"
43 #include "gc/shared/oopStorageSet.hpp"
44 #include "gc/shared/stringdedup/stringDedup.hpp"
45 #include "jfr/jfrEvents.hpp"
46 #include "jvm.h"
47 #include "jvmtifiles/jvmtiEnv.hpp"
48 #include "logging/log.hpp"
49 #include "logging/logAsyncWriter.hpp"
50 #include "logging/logConfiguration.hpp"
51 #include "memory/allocation.inline.hpp"
52 #include "memory/iterator.hpp"
53 #include "memory/oopFactory.hpp"
54 #include "memory/resourceArea.hpp"
55 #include "memory/universe.hpp"
56 #include "nmt/memTracker.hpp"
57 #include "oops/instanceKlass.hpp"
58 #include "oops/klass.inline.hpp"
59 #include "oops/oop.inline.hpp"
60 #include "oops/symbol.hpp"
61 #include "prims/jvm_misc.hpp"
62 #include "prims/jvmtiAgentList.hpp"
63 #include "prims/jvmtiEnvBase.hpp"
64 #include "runtime/arguments.hpp"
65 #include "runtime/fieldDescriptor.inline.hpp"
66 #include "runtime/flags/jvmFlagLimit.hpp"
67 #include "runtime/globals.hpp"
68 #include "runtime/globals_extension.hpp"
69 #include "runtime/handles.inline.hpp"
70 #include "runtime/interfaceSupport.inline.hpp"
71 #include "runtime/java.hpp"
72 #include "runtime/javaCalls.hpp"
73 #include "runtime/javaThread.inline.hpp"
74 #include "runtime/jniHandles.inline.hpp"
75 #include "runtime/jniPeriodicChecker.hpp"
76 #include "runtime/lockStack.inline.hpp"
77 #include "runtime/monitorDeflationThread.hpp"
78 #include "runtime/mutexLocker.hpp"
79 #include "runtime/nonJavaThread.hpp"
80 #include "runtime/objectMonitor.inline.hpp"
81 #include "runtime/osThread.hpp"
82 #include "runtime/safepoint.hpp"
83 #include "runtime/safepointMechanism.inline.hpp"
84 #include "runtime/safepointVerifiers.hpp"
85 #include "runtime/serviceThread.hpp"
86 #include "runtime/sharedRuntime.hpp"
87 #include "runtime/stackWatermarkSet.inline.hpp"
88 #include "runtime/statSampler.hpp"
89 #include "runtime/stubCodeGenerator.hpp"
90 #include "runtime/thread.inline.hpp"
91 #include "runtime/threadSMR.inline.hpp"
92 #include "runtime/threads.hpp"
93 #include "runtime/timer.hpp"
94 #include "runtime/timerTrace.hpp"
95 #include "runtime/trimNativeHeap.hpp"
96 #include "runtime/vmOperations.hpp"
97 #include "runtime/vm_version.hpp"
98 #include "services/attachListener.hpp"
99 #include "services/management.hpp"
100 #include "services/threadIdTable.hpp"
101 #include "services/threadService.hpp"
102 #include "utilities/dtrace.hpp"
103 #include "utilities/events.hpp"
104 #include "utilities/macros.hpp"
105 #include "utilities/vmError.hpp"
106 #if INCLUDE_JVMCI
107 #include "jvmci/jvmci.hpp"
108 #include "jvmci/jvmciEnv.hpp"
109 #endif
110 #ifdef COMPILER2
111 #include "opto/idealGraphPrinter.hpp"
112 #endif
113 #if INCLUDE_JFR
114 #include "jfr/jfr.hpp"
115 #endif
116
117 // Initialization after module runtime initialization
118 void universe_post_module_init(); // must happen after call_initPhase2
119
120
121 static void initialize_class(Symbol* class_name, TRAPS) {
122 Klass* klass = SystemDictionary::resolve_or_fail(class_name, true, CHECK);
123 InstanceKlass::cast(klass)->initialize(CHECK);
124 }
125
126
127 // Creates the initial ThreadGroup
128 static Handle create_initial_thread_group(TRAPS) {
129 Handle system_instance = JavaCalls::construct_new_instance(
130 vmClasses::ThreadGroup_klass(),
131 vmSymbols::void_method_signature(),
132 CHECK_NH);
133 Universe::set_system_thread_group(system_instance());
134
135 Handle string = java_lang_String::create_from_str("main", CHECK_NH);
136 Handle main_instance = JavaCalls::construct_new_instance(
137 vmClasses::ThreadGroup_klass(),
138 vmSymbols::threadgroup_string_void_signature(),
139 system_instance,
140 string,
141 CHECK_NH);
142 return main_instance;
143 }
144
145 // Creates the initial Thread, and sets it to running.
146 static void create_initial_thread(Handle thread_group, JavaThread* thread,
147 TRAPS) {
148 InstanceKlass* ik = vmClasses::Thread_klass();
149 assert(ik->is_initialized(), "must be");
150 instanceHandle thread_oop = ik->allocate_instance_handle(CHECK);
151
152 // Cannot use JavaCalls::construct_new_instance because the java.lang.Thread
153 // constructor calls Thread.current(), which must be set here for the
154 // initial thread.
155 java_lang_Thread::set_thread(thread_oop(), thread);
156 thread->set_threadOopHandles(thread_oop());
157
158 Handle string = java_lang_String::create_from_str("main", CHECK);
159
160 JavaValue result(T_VOID);
161 JavaCalls::call_special(&result, thread_oop,
162 ik,
163 vmSymbols::object_initializer_name(),
164 vmSymbols::threadgroup_string_void_signature(),
165 thread_group,
166 string,
167 CHECK);
168
169 JFR_ONLY(assert(JFR_JVM_THREAD_ID(thread) == static_cast<traceid>(java_lang_Thread::thread_id(thread_oop())),
170 "initial tid mismatch");)
171
172 // Set thread status to running since main thread has
173 // been started and running.
174 java_lang_Thread::set_thread_status(thread_oop(),
175 JavaThreadStatus::RUNNABLE);
176 }
177
178 // Extract version and vendor specific information from
179 // java.lang.VersionProps fields.
180 // Returned char* is allocated in the thread's resource area
181 // so must be copied for permanency.
182 static const char* get_java_version_info(InstanceKlass* ik,
183 Symbol* field_name) {
184 fieldDescriptor fd;
185 bool found = ik != nullptr &&
186 ik->find_local_field(field_name,
187 vmSymbols::string_signature(), &fd);
188 if (found) {
189 oop name_oop = ik->java_mirror()->obj_field(fd.offset());
190 if (name_oop == nullptr) {
191 return nullptr;
192 }
193 const char* name = java_lang_String::as_utf8_string(name_oop);
194 return name;
195 } else {
196 return nullptr;
197 }
198 }
199
200 // ======= Threads ========
201
202 // The Threads class links together all active threads, and provides
203 // operations over all threads. It is protected by the Threads_lock,
204 // which is also used in other global contexts like safepointing.
205 // ThreadsListHandles are used to safely perform operations on one
206 // or more threads without the risk of the thread exiting during the
207 // operation.
208 //
209 // Note: The Threads_lock is currently more widely used than we
210 // would like. We are actively migrating Threads_lock uses to other
211 // mechanisms in order to reduce Threads_lock contention.
212
213 int Threads::_number_of_threads = 0;
214 int Threads::_number_of_non_daemon_threads = 0;
215 int Threads::_return_code = 0;
216 uintx Threads::_thread_claim_token = 1; // Never zero.
217
218 #ifdef ASSERT
219 bool Threads::_vm_complete = false;
220 #endif
221
222 // General purpose hook into Java code, run once when the VM is initialized.
223 // The Java library method itself may be changed independently from the VM.
224 static void call_postVMInitHook(TRAPS) {
225 Klass* klass = SystemDictionary::resolve_or_null(vmSymbols::jdk_internal_vm_PostVMInitHook(), THREAD);
226 if (klass != nullptr) {
227 JavaValue result(T_VOID);
228 JavaCalls::call_static(&result, klass, vmSymbols::run_method_name(),
229 vmSymbols::void_method_signature(),
230 CHECK);
231 }
232 }
233
234 // All NonJavaThreads (i.e., every non-JavaThread in the system).
235 void Threads::non_java_threads_do(ThreadClosure* tc) {
236 NoSafepointVerifier nsv;
237 for (NonJavaThread::Iterator njti; !njti.end(); njti.step()) {
238 tc->do_thread(njti.current());
239 }
240 }
241
242 // All JavaThreads
243 #define ALL_JAVA_THREADS(X) \
244 for (JavaThread* X : *ThreadsSMRSupport::get_java_thread_list())
245
246 // All JavaThreads
247 void Threads::java_threads_do(ThreadClosure* tc) {
248 assert_locked_or_safepoint(Threads_lock);
249 // ALL_JAVA_THREADS iterates through all JavaThreads.
250 ALL_JAVA_THREADS(p) {
251 tc->do_thread(p);
252 }
253 }
254
255 // All JavaThreads + all non-JavaThreads (i.e., every thread in the system).
256 void Threads::threads_do(ThreadClosure* tc) {
257 assert_locked_or_safepoint(Threads_lock);
258 java_threads_do(tc);
259 non_java_threads_do(tc);
260 }
261
262 void Threads::possibly_parallel_threads_do(bool is_par, ThreadClosure* tc) {
263 assert_at_safepoint();
264
265 uintx claim_token = Threads::thread_claim_token();
266 ALL_JAVA_THREADS(p) {
267 if (p->claim_threads_do(is_par, claim_token)) {
268 tc->do_thread(p);
269 }
270 }
271 for (NonJavaThread::Iterator njti; !njti.end(); njti.step()) {
272 Thread* current = njti.current();
273 if (current->claim_threads_do(is_par, claim_token)) {
274 tc->do_thread(current);
275 }
276 }
277 }
278
279 // The system initialization in the library has three phases.
280 //
281 // Phase 1: java.lang.System class initialization
282 // java.lang.System is a primordial class loaded and initialized
283 // by the VM early during startup. java.lang.System.<clinit>
284 // only does registerNatives and keeps the rest of the class
285 // initialization work later until thread initialization completes.
286 //
287 // System.initPhase1 initializes the system properties, the static
288 // fields in, out, and err. Set up java signal handlers, OS-specific
289 // system settings, and thread group of the main thread.
290 static void call_initPhase1(TRAPS) {
291 Klass* klass = vmClasses::System_klass();
292 JavaValue result(T_VOID);
293 JavaCalls::call_static(&result, klass, vmSymbols::initPhase1_name(),
294 vmSymbols::void_method_signature(), CHECK);
295 }
296
297 // Phase 2. Module system initialization
298 // This will initialize the module system. Only java.base classes
299 // can be loaded until phase 2 completes.
300 //
301 // Call System.initPhase2 after the compiler initialization and jsr292
302 // classes get initialized because module initialization runs a lot of java
303 // code, that for performance reasons, should be compiled. Also, this will
304 // enable the startup code to use lambda and other language features in this
305 // phase and onward.
306 //
307 // After phase 2, The VM will begin search classes from -Xbootclasspath/a.
308 static void call_initPhase2(TRAPS) {
309 TraceTime timer("Initialize module system", TRACETIME_LOG(Info, startuptime));
310
311 Klass* klass = vmClasses::System_klass();
312
313 JavaValue result(T_INT);
314 JavaCallArguments args;
315 args.push_int(DisplayVMOutputToStderr);
316 args.push_int(log_is_enabled(Debug, init)); // print stack trace if exception thrown
317 JavaCalls::call_static(&result, klass, vmSymbols::initPhase2_name(),
318 vmSymbols::boolean_boolean_int_signature(), &args, CHECK);
319 if (result.get_jint() != JNI_OK) {
320 vm_exit_during_initialization(); // no message or exception
321 }
322
323 universe_post_module_init();
324 }
325
326 // Phase 3. final setup - set security manager, system class loader and TCCL
327 //
328 // This will instantiate and set the security manager, set the system class
329 // loader as well as the thread context class loader. The security manager
330 // and system class loader may be a custom class loaded from -Xbootclasspath/a,
331 // other modules or the application's classpath.
332 static void call_initPhase3(TRAPS) {
333 Klass* klass = vmClasses::System_klass();
334 JavaValue result(T_VOID);
335 JavaCalls::call_static(&result, klass, vmSymbols::initPhase3_name(),
336 vmSymbols::void_method_signature(), CHECK);
337 }
338
339 void Threads::initialize_java_lang_classes(JavaThread* main_thread, TRAPS) {
340 TraceTime timer("Initialize java.lang classes", TRACETIME_LOG(Info, startuptime));
341
342 initialize_class(vmSymbols::java_lang_String(), CHECK);
343
344 // Inject CompactStrings value after the static initializers for String ran.
345 java_lang_String::set_compact_strings(CompactStrings);
346
347 // Initialize java_lang.System (needed before creating the thread)
348 initialize_class(vmSymbols::java_lang_System(), CHECK);
349 // The VM creates & returns objects of this class. Make sure it's initialized.
350 initialize_class(vmSymbols::java_lang_Class(), CHECK);
351 initialize_class(vmSymbols::java_lang_ThreadGroup(), CHECK);
352 Handle thread_group = create_initial_thread_group(CHECK);
353 Universe::set_main_thread_group(thread_group());
354 initialize_class(vmSymbols::java_lang_Thread(), CHECK);
355 create_initial_thread(thread_group, main_thread, CHECK);
356
357 // The VM creates objects of this class.
358 initialize_class(vmSymbols::java_lang_Module(), CHECK);
359
360 #ifdef ASSERT
361 InstanceKlass *k = vmClasses::UnsafeConstants_klass();
362 assert(k->is_not_initialized(), "UnsafeConstants should not already be initialized");
363 #endif
364
365 // initialize the hardware-specific constants needed by Unsafe
366 initialize_class(vmSymbols::jdk_internal_misc_UnsafeConstants(), CHECK);
367 jdk_internal_misc_UnsafeConstants::set_unsafe_constants();
368
369 // The VM preresolves methods to these classes. Make sure that they get initialized
370 initialize_class(vmSymbols::java_lang_reflect_Method(), CHECK);
371 initialize_class(vmSymbols::java_lang_ref_Finalizer(), CHECK);
372
373 // Phase 1 of the system initialization in the library, java.lang.System class initialization
374 call_initPhase1(CHECK);
375
376 // Get the Java runtime name, version, and vendor info after java.lang.System is initialized.
377 // Some values are actually configure-time constants but some can be set via the jlink tool and
378 // so must be read dynamically. We treat them all the same.
379 InstanceKlass* ik = SystemDictionary::find_instance_klass(THREAD, vmSymbols::java_lang_VersionProps(),
380 Handle(), Handle());
381 {
382 ResourceMark rm(main_thread);
383 JDK_Version::set_java_version(get_java_version_info(ik, vmSymbols::java_version_name()));
384
385 JDK_Version::set_runtime_name(get_java_version_info(ik, vmSymbols::java_runtime_name_name()));
386
387 JDK_Version::set_runtime_version(get_java_version_info(ik, vmSymbols::java_runtime_version_name()));
388
389 JDK_Version::set_runtime_vendor_version(get_java_version_info(ik, vmSymbols::java_runtime_vendor_version_name()));
390
391 JDK_Version::set_runtime_vendor_vm_bug_url(get_java_version_info(ik, vmSymbols::java_runtime_vendor_vm_bug_url_name()));
392 }
393
394 // an instance of OutOfMemory exception has been allocated earlier
395 initialize_class(vmSymbols::java_lang_OutOfMemoryError(), CHECK);
396 initialize_class(vmSymbols::java_lang_NullPointerException(), CHECK);
397 initialize_class(vmSymbols::java_lang_ClassCastException(), CHECK);
398 initialize_class(vmSymbols::java_lang_ArrayStoreException(), CHECK);
399 initialize_class(vmSymbols::java_lang_ArithmeticException(), CHECK);
400 initialize_class(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), CHECK);
401 initialize_class(vmSymbols::java_lang_StackOverflowError(), CHECK);
402 initialize_class(vmSymbols::java_lang_IllegalMonitorStateException(), CHECK);
403 initialize_class(vmSymbols::java_lang_IllegalArgumentException(), CHECK);
404 }
405
406 void Threads::initialize_jsr292_core_classes(TRAPS) {
407 TraceTime timer("Initialize java.lang.invoke classes", TRACETIME_LOG(Info, startuptime));
408
409 initialize_class(vmSymbols::java_lang_invoke_MethodHandle(), CHECK);
410 initialize_class(vmSymbols::java_lang_invoke_ResolvedMethodName(), CHECK);
411 initialize_class(vmSymbols::java_lang_invoke_MemberName(), CHECK);
412 initialize_class(vmSymbols::java_lang_invoke_MethodHandleNatives(), CHECK);
413 }
414
415 jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) {
416 extern void JDK_Version_init();
417
418 // Preinitialize version info.
419 VM_Version::early_initialize();
420
421 // Check version
422 if (!is_supported_jni_version(args->version)) return JNI_EVERSION;
423
424 // Initialize library-based TLS
425 ThreadLocalStorage::init();
426
427 // Initialize the output stream module
428 ostream_init();
429
430 // Process java launcher properties.
431 Arguments::process_sun_java_launcher_properties(args);
432
433 // Initialize the os module
434 os::init();
435
436 MACOS_AARCH64_ONLY(os::current_thread_enable_wx(WXWrite));
437
438 // Record VM creation timing statistics
439 TraceVmCreationTime create_vm_timer;
440 create_vm_timer.start();
441
442 // Initialize system properties.
443 Arguments::init_system_properties();
444
445 // So that JDK version can be used as a discriminator when parsing arguments
446 JDK_Version_init();
447
448 // Update/Initialize System properties after JDK version number is known
449 Arguments::init_version_specific_system_properties();
450
451 // Make sure to initialize log configuration *before* parsing arguments
452 LogConfiguration::initialize(create_vm_timer.begin_time());
453
454 // Parse arguments
455 // Note: this internally calls os::init_container_support()
456 jint parse_result = Arguments::parse(args);
457 if (parse_result != JNI_OK) return parse_result;
458
459 // Initialize NMT right after argument parsing to keep the pre-NMT-init window small.
460 MemTracker::initialize();
461
462 os::init_before_ergo();
463
464 jint ergo_result = Arguments::apply_ergo();
465 if (ergo_result != JNI_OK) return ergo_result;
466
467 // Final check of all ranges after ergonomics which may change values.
468 if (!JVMFlagLimit::check_all_ranges()) {
469 return JNI_EINVAL;
470 }
471
472 // Final check of all 'AfterErgo' constraints after ergonomics which may change values.
473 bool constraint_result = JVMFlagLimit::check_all_constraints(JVMFlagConstraintPhase::AfterErgo);
474 if (!constraint_result) {
475 return JNI_EINVAL;
476 }
477
478 if (PauseAtStartup) {
479 os::pause();
480 }
481
482 HOTSPOT_VM_INIT_BEGIN();
483
484 // Timing (must come after argument parsing)
485 TraceTime timer("Create VM", TRACETIME_LOG(Info, startuptime));
486
487 // Initialize the os module after parsing the args
488 jint os_init_2_result = os::init_2();
489 if (os_init_2_result != JNI_OK) return os_init_2_result;
490
491 #ifdef CAN_SHOW_REGISTERS_ON_ASSERT
492 // Initialize assert poison page mechanism.
493 if (ShowRegistersOnAssert) {
494 initialize_assert_poison();
495 }
496 #endif // CAN_SHOW_REGISTERS_ON_ASSERT
497
498 SafepointMechanism::initialize();
499
500 jint adjust_after_os_result = Arguments::adjust_after_os();
501 if (adjust_after_os_result != JNI_OK) return adjust_after_os_result;
502
503 // Initialize output stream logging
504 ostream_init_log();
505
506 // Launch -agentlib/-agentpath and converted -Xrun agents
507 JvmtiAgentList::load_agents();
508
509 // Initialize Threads state
510 _number_of_threads = 0;
511 _number_of_non_daemon_threads = 0;
512
513 // Initialize global data structures and create system classes in heap
514 vm_init_globals();
515
516 #if INCLUDE_JVMCI
517 if (JVMCICounterSize > 0) {
518 JavaThread::_jvmci_old_thread_counters = NEW_C_HEAP_ARRAY(jlong, JVMCICounterSize, mtJVMCI);
519 memset(JavaThread::_jvmci_old_thread_counters, 0, sizeof(jlong) * JVMCICounterSize);
520 } else {
521 JavaThread::_jvmci_old_thread_counters = nullptr;
522 }
523 #endif // INCLUDE_JVMCI
524
525 // Initialize OopStorage for threadObj
526 JavaThread::_thread_oop_storage = OopStorageSet::create_strong("Thread OopStorage", mtThread);
527
528 // Attach the main thread to this os thread
529 JavaThread* main_thread = new JavaThread();
530 main_thread->set_thread_state(_thread_in_vm);
531 main_thread->initialize_thread_current();
532 // must do this before set_active_handles
533 main_thread->record_stack_base_and_size();
534 main_thread->register_thread_stack_with_NMT();
535 main_thread->set_active_handles(JNIHandleBlock::allocate_block());
536 MACOS_AARCH64_ONLY(main_thread->init_wx());
537
538 if (!Thread::set_as_starting_thread(main_thread)) {
539 vm_shutdown_during_initialization(
540 "Failed necessary internal allocation. Out of swap space");
541 main_thread->smr_delete();
542 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
543 return JNI_ENOMEM;
544 }
545
546 JFR_ONLY(Jfr::initialize_main_thread(main_thread);)
547
548 // Enable guard page *after* os::create_main_thread(), otherwise it would
549 // crash Linux VM, see notes in os_linux.cpp.
550 main_thread->stack_overflow_state()->create_stack_guard_pages();
551
552 // Initialize Java-Level synchronization subsystem
553 ObjectMonitor::Initialize();
554 ObjectSynchronizer::initialize();
555
556 // Initialize global modules
557 jint status = init_globals();
558 if (status != JNI_OK) {
559 main_thread->smr_delete();
560 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
561 return status;
562 }
563
564 // Create WatcherThread as soon as we can since we need it in case
565 // of hangs during error reporting.
566 WatcherThread::start();
567
568 // Add main_thread to threads list to finish barrier setup with
569 // on_thread_attach. Should be before starting to build Java objects in
570 // init_globals2, which invokes barriers.
571 {
572 MutexLocker mu(Threads_lock);
573 Threads::add(main_thread);
574 }
575
576 status = init_globals2();
577 if (status != JNI_OK) {
578 Threads::remove(main_thread, false);
579 // It is possible that we managed to fully initialize Universe but have then
580 // failed by throwing an exception. In that case our caller JNI_CreateJavaVM
581 // will want to report it, so we can't delete the main thread.
582 if (!main_thread->has_pending_exception()) {
583 main_thread->smr_delete();
584 }
585 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
586 return status;
587 }
588
589 JFR_ONLY(Jfr::on_create_vm_1();)
590
591 // Should be done after the heap is fully created
592 main_thread->cache_global_variables();
593
594 // Any JVMTI raw monitors entered in onload will transition into
595 // real raw monitor. VM is setup enough here for raw monitor enter.
596 JvmtiExport::transition_pending_onload_raw_monitors();
597
598 // Create the VMThread
599 { TraceTime timer("Start VMThread", TRACETIME_LOG(Info, startuptime));
600
601 VMThread::create();
602 VMThread* vmthread = VMThread::vm_thread();
603
604 if (!os::create_thread(vmthread, os::vm_thread)) {
605 vm_exit_during_initialization("Cannot create VM thread. "
606 "Out of system resources.");
607 }
608
609 // Wait for the VM thread to become ready, and VMThread::run to initialize
610 // Monitors can have spurious returns, must always check another state flag
611 {
612 MonitorLocker ml(Notify_lock);
613 os::start_thread(vmthread);
614 while (!vmthread->is_running()) {
615 ml.wait();
616 }
617 }
618 }
619
620 assert(Universe::is_fully_initialized(), "not initialized");
621 if (VerifyDuringStartup) {
622 // Make sure we're starting with a clean slate.
623 VM_Verify verify_op;
624 VMThread::execute(&verify_op);
625 }
626
627 // We need this to update the java.vm.info property in case any flags used
628 // to initially define it have been changed. This is needed for both CDS
629 // since UseSharedSpaces may be changed after java.vm.info
630 // is initially computed. See Abstract_VM_Version::vm_info_string().
631 // This update must happen before we initialize the java classes, but
632 // after any initialization logic that might modify the flags.
633 Arguments::update_vm_info_property(VM_Version::vm_info_string());
634
635 JavaThread* THREAD = JavaThread::current(); // For exception macros.
636 HandleMark hm(THREAD);
637
638 // Always call even when there are not JVMTI environments yet, since environments
639 // may be attached late and JVMTI must track phases of VM execution
640 JvmtiExport::enter_early_start_phase();
641
642 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
643 JvmtiExport::post_early_vm_start();
644
645 // Launch -Xrun agents early if EagerXrunInit is set
646 if (EagerXrunInit) {
647 JvmtiAgentList::load_xrun_agents();
648 }
649
650 initialize_java_lang_classes(main_thread, CHECK_JNI_ERR);
651
652 quicken_jni_functions();
653
654 // No more stub generation allowed after that point.
655 StubCodeDesc::freeze();
656
657 // Set flag that basic initialization has completed. Used by exceptions and various
658 // debug stuff, that does not work until all basic classes have been initialized.
659 set_init_completed();
660
661 LogConfiguration::post_initialize();
662 Metaspace::post_initialize();
663 MutexLockerImpl::post_initialize();
664
665 HOTSPOT_VM_INIT_END();
666
667 // record VM initialization completion time
668 #if INCLUDE_MANAGEMENT
669 Management::record_vm_init_completed();
670 #endif // INCLUDE_MANAGEMENT
671
672 log_info(os)("Initialized VM with process ID %d", os::current_process_id());
673
674 if (!FLAG_IS_DEFAULT(CreateCoredumpOnCrash) && CreateCoredumpOnCrash) {
675 char buffer[2*JVM_MAXPATHLEN];
676 os::check_core_dump_prerequisites(buffer, sizeof(buffer), true);
677 }
678
679 // Signal Dispatcher needs to be started before VMInit event is posted
680 os::initialize_jdk_signal_support(CHECK_JNI_ERR);
681
682 // Start Attach Listener if +StartAttachListener or it can't be started lazily
683 if (!DisableAttachMechanism) {
684 AttachListener::vm_start();
685 if (StartAttachListener || AttachListener::init_at_startup()) {
686 AttachListener::init();
687 }
688 }
689
690 // Launch -Xrun agents if EagerXrunInit is not set.
691 if (!EagerXrunInit) {
692 JvmtiAgentList::load_xrun_agents();
693 }
694
695 Arena::start_chunk_pool_cleaner_task();
696
697 // Start the service thread
698 // The service thread enqueues JVMTI deferred events and does various hashtable
699 // and other cleanups. Needs to start before the compilers start posting events.
700 ServiceThread::initialize();
701
702 // Start the monitor deflation thread:
703 MonitorDeflationThread::initialize();
704
705 // initialize compiler(s)
706 #if defined(COMPILER1) || COMPILER2_OR_JVMCI
707 bool init_compilation = true;
708 #if INCLUDE_JVMCI
709 bool force_JVMCI_initialization = false;
710 if (EnableJVMCI) {
711 // Initialize JVMCI eagerly when it is explicitly requested.
712 // Or when JVMCILibDumpJNIConfig or JVMCIPrintProperties is enabled.
713 force_JVMCI_initialization = EagerJVMCI || JVMCIPrintProperties || JVMCILibDumpJNIConfig;
714 if (!force_JVMCI_initialization && UseJVMCICompiler && !UseJVMCINativeLibrary && (!UseInterpreter || !BackgroundCompilation)) {
715 // Force initialization of jarjvmci otherwise requests for blocking
716 // compilations will not actually block until jarjvmci is initialized.
717 force_JVMCI_initialization = true;
718 }
719 if (JVMCIPrintProperties || JVMCILibDumpJNIConfig) {
720 // Both JVMCILibDumpJNIConfig and JVMCIPrintProperties exit the VM
721 // so compilation should be disabled. This prevents dumping or
722 // printing from happening more than once.
723 init_compilation = false;
724 }
725 }
726 #endif
727 if (init_compilation) {
728 CompileBroker::compilation_init(CHECK_JNI_ERR);
729 }
730 #endif
731
732 // Start string deduplication thread if requested.
733 if (StringDedup::is_enabled()) {
734 StringDedup::start();
735 }
736
737 // Pre-initialize some JSR292 core classes to avoid deadlock during class loading.
738 // It is done after compilers are initialized, because otherwise compilations of
739 // signature polymorphic MH intrinsics can be missed
740 // (see SystemDictionary::find_method_handle_intrinsic).
741 initialize_jsr292_core_classes(CHECK_JNI_ERR);
742
743 // This will initialize the module system. Only java.base classes can be
744 // loaded until phase 2 completes
745 call_initPhase2(CHECK_JNI_ERR);
746
747 JFR_ONLY(Jfr::on_create_vm_2();)
748
749 // Always call even when there are not JVMTI environments yet, since environments
750 // may be attached late and JVMTI must track phases of VM execution
751 JvmtiExport::enter_start_phase();
752
753 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
754 JvmtiExport::post_vm_start();
755
756 // Final system initialization including security manager and system class loader
757 call_initPhase3(CHECK_JNI_ERR);
758
759 // cache the system and platform class loaders
760 SystemDictionary::compute_java_loaders(CHECK_JNI_ERR);
761
762 if (Continuations::enabled()) {
763 // Initialize Continuation class now so that failure to create enterSpecial/doYield
764 // special nmethods due to limited CodeCache size can be treated as a fatal error at
765 // startup with the proper message that CodeCache size is too small.
766 initialize_class(vmSymbols::jdk_internal_vm_Continuation(), CHECK_JNI_ERR);
767 }
768
769 #if INCLUDE_CDS
770 // capture the module path info from the ModuleEntryTable
771 ClassLoader::initialize_module_path(THREAD);
772 if (HAS_PENDING_EXCEPTION) {
773 java_lang_Throwable::print(PENDING_EXCEPTION, tty);
774 vm_exit_during_initialization("ClassLoader::initialize_module_path() failed unexpectedly");
775 }
776 #endif
777
778 #if INCLUDE_JVMCI
779 if (force_JVMCI_initialization) {
780 JVMCI::initialize_compiler(CHECK_JNI_ERR);
781 }
782 #endif
783
784 if (NativeHeapTrimmer::enabled()) {
785 NativeHeapTrimmer::initialize();
786 }
787
788 // Always call even when there are not JVMTI environments yet, since environments
789 // may be attached late and JVMTI must track phases of VM execution
790 JvmtiExport::enter_live_phase();
791
792 // Make perfmemory accessible
793 PerfMemory::set_accessible(true);
794
795 // Notify JVMTI agents that VM initialization is complete - nop if no agents.
796 JvmtiExport::post_vm_initialized();
797
798 JFR_ONLY(Jfr::on_create_vm_3();)
799
800 #if INCLUDE_MANAGEMENT
801 Management::initialize(THREAD);
802
803 if (HAS_PENDING_EXCEPTION) {
804 // management agent fails to start possibly due to
805 // configuration problem and is responsible for printing
806 // stack trace if appropriate. Simply exit VM.
807 vm_exit(1);
808 }
809 #endif // INCLUDE_MANAGEMENT
810
811 StatSampler::engage();
812 if (CheckJNICalls) JniPeriodicChecker::engage();
813
814 call_postVMInitHook(THREAD);
815 // The Java side of PostVMInitHook.run must deal with all
816 // exceptions and provide means of diagnosis.
817 if (HAS_PENDING_EXCEPTION) {
818 CLEAR_PENDING_EXCEPTION;
819 }
820
821 // Let WatcherThread run all registered periodic tasks now.
822 // NOTE: All PeriodicTasks should be registered by now. If they
823 // aren't, late joiners might appear to start slowly (we might
824 // take a while to process their first tick).
825 WatcherThread::run_all_tasks();
826
827 create_vm_timer.end();
828 #ifdef ASSERT
829 _vm_complete = true;
830 #endif
831
832 if (CDSConfig::is_dumping_static_archive()) {
833 MetaspaceShared::preload_and_dump(CHECK_JNI_ERR);
834 }
835
836 if (log_is_enabled(Info, perf, class, link)) {
837 LogStreamHandle(Info, perf, class, link) log;
838 log.print_cr("At VM initialization completion:");
839 ClassLoader::print_counters(&log);
840 }
841
842 return JNI_OK;
843 }
844
845 // Threads::destroy_vm() is normally called from jni_DestroyJavaVM() when
846 // the program falls off the end of main(). Another VM exit path is through
847 // vm_exit(), when the program calls System.exit() to return a value, or when
848 // there is a serious error in VM.
849 // These two separate shutdown paths are not exactly the same, but they share
850 // Shutdown.shutdown() at Java level and before_exit() and VM_Exit op at VM level.
851 //
852 // Shutdown sequence:
853 // + Shutdown native memory tracking if it is on
854 // + Wait until we are the last non-daemon thread to execute
855 // <-- every thing is still working at this moment -->
856 // + Call java.lang.Shutdown.shutdown(), which will invoke Java level
857 // shutdown hooks
858 // + Call before_exit(), prepare for VM exit
859 // > run VM level shutdown hooks (they are registered through JVM_OnExit(),
860 // currently the only user of this mechanism is File.deleteOnExit())
861 // > stop StatSampler, watcher thread,
862 // post thread end and vm death events to JVMTI,
863 // stop signal thread
864 // + Call JavaThread::exit(), it will:
865 // > release JNI handle blocks, remove stack guard pages
866 // > remove this thread from Threads list
867 // <-- no more Java code from this thread after this point -->
868 // + Stop VM thread, it will bring the remaining VM to a safepoint and stop
869 // the compiler threads at safepoint
870 // <-- do not use anything that could get blocked by Safepoint -->
871 // + Disable tracing at JNI/JVM barriers
872 // + Set _vm_exited flag for threads that are still running native code
873 // + Call exit_globals()
874 // > deletes tty
875 // > deletes PerfMemory resources
876 // + Delete this thread
877 // + Return to caller
878
879 void Threads::destroy_vm() {
880 JavaThread* thread = JavaThread::current();
881
882 #ifdef ASSERT
883 _vm_complete = false;
884 #endif
885 // Wait until we are the last non-daemon thread to execute, or
886 // if we are a daemon then wait until the last non-daemon thread has
887 // executed.
888 bool daemon = java_lang_Thread::is_daemon(thread->threadObj());
889 int expected = daemon ? 0 : 1;
890 {
891 MonitorLocker nu(Threads_lock);
892 while (Threads::number_of_non_daemon_threads() > expected)
893 // This wait should make safepoint checks, wait without a timeout.
894 nu.wait(0);
895 }
896
897 EventShutdown e;
898 if (e.should_commit()) {
899 e.set_reason("No remaining non-daemon Java threads");
900 e.commit();
901 }
902
903 // Hang forever on exit if we are reporting an error.
904 if (ShowMessageBoxOnError && VMError::is_error_reported()) {
905 os::infinite_sleep();
906 }
907 os::wait_for_keypress_at_exit();
908
909 // run Java level shutdown hooks
910 thread->invoke_shutdown_hooks();
911
912 before_exit(thread);
913
914 thread->exit(true);
915
916 // We are no longer on the main thread list but could still be in a
917 // secondary list where another thread may try to interact with us.
918 // So wait until all such interactions are complete before we bring
919 // the VM to the termination safepoint. Normally this would be done
920 // using thread->smr_delete() below where we delete the thread, but
921 // we can't call that after the termination safepoint is active as
922 // we will deadlock on the Threads_lock. Once all interactions are
923 // complete it is safe to directly delete the thread at any time.
924 ThreadsSMRSupport::wait_until_not_protected(thread);
925
926 // Stop VM thread.
927 {
928 // 4945125 The vm thread comes to a safepoint during exit.
929 // GC vm_operations can get caught at the safepoint, and the
930 // heap is unparseable if they are caught. Grab the Heap_lock
931 // to prevent this. The GC vm_operations will not be able to
932 // queue until after the vm thread is dead. After this point,
933 // we'll never emerge out of the safepoint before the VM exits.
934 // Assert that the thread is terminated so that acquiring the
935 // Heap_lock doesn't cause the terminated thread to participate in
936 // the safepoint protocol.
937
938 assert(thread->is_terminated(), "must be terminated here");
939 MutexLocker ml(Heap_lock);
940
941 VMThread::wait_for_vm_thread_exit();
942 assert(SafepointSynchronize::is_at_safepoint(), "VM thread should exit at Safepoint");
943 VMThread::destroy();
944 }
945
946 // Now, all Java threads are gone except daemon threads. Daemon threads
947 // running Java code or in VM are stopped by the Safepoint. However,
948 // daemon threads executing native code are still running. But they
949 // will be stopped at native=>Java/VM barriers. Note that we can't
950 // simply kill or suspend them, as it is inherently deadlock-prone.
951
952 VM_Exit::set_vm_exited();
953
954 // Clean up ideal graph printers after the VMThread has started
955 // the final safepoint which will block all the Compiler threads.
956 // Note that this Thread has already logically exited so the
957 // clean_up() function's use of a JavaThreadIteratorWithHandle
958 // would be a problem except set_vm_exited() has remembered the
959 // shutdown thread which is granted a policy exception.
960 #if defined(COMPILER2) && !defined(PRODUCT)
961 IdealGraphPrinter::clean_up();
962 #endif
963
964 notify_vm_shutdown();
965
966 // exit_globals() will delete tty
967 exit_globals();
968
969 // Deleting the shutdown thread here is safe. See comment on
970 // wait_until_not_protected() above.
971 delete thread;
972
973 #if INCLUDE_JVMCI
974 if (JVMCICounterSize > 0) {
975 FREE_C_HEAP_ARRAY(jlong, JavaThread::_jvmci_old_thread_counters);
976 }
977 #endif
978
979 LogConfiguration::finalize();
980 }
981
982
983 jboolean Threads::is_supported_jni_version_including_1_1(jint version) {
984 if (version == JNI_VERSION_1_1) return JNI_TRUE;
985 return is_supported_jni_version(version);
986 }
987
988
989 jboolean Threads::is_supported_jni_version(jint version) {
990 if (version == JNI_VERSION_1_2) return JNI_TRUE;
991 if (version == JNI_VERSION_1_4) return JNI_TRUE;
992 if (version == JNI_VERSION_1_6) return JNI_TRUE;
993 if (version == JNI_VERSION_1_8) return JNI_TRUE;
994 if (version == JNI_VERSION_9) return JNI_TRUE;
995 if (version == JNI_VERSION_10) return JNI_TRUE;
996 if (version == JNI_VERSION_19) return JNI_TRUE;
997 if (version == JNI_VERSION_20) return JNI_TRUE;
998 if (version == JNI_VERSION_21) return JNI_TRUE;
999 if (version == JNI_VERSION_24) return JNI_TRUE;
1000 return JNI_FALSE;
1001 }
1002
1003 void Threads::add(JavaThread* p, bool force_daemon) {
1004 // The threads lock must be owned at this point
1005 assert(Threads_lock->owned_by_self(), "must have threads lock");
1006
1007 BarrierSet::barrier_set()->on_thread_attach(p);
1008
1009 // Once a JavaThread is added to the Threads list, smr_delete() has
1010 // to be used to delete it. Otherwise we can just delete it directly.
1011 p->set_on_thread_list();
1012
1013 _number_of_threads++;
1014 oop threadObj = p->threadObj();
1015 bool daemon = true;
1016 // Bootstrapping problem: threadObj can be null for initial
1017 // JavaThread (or for threads attached via JNI)
1018 if (!force_daemon &&
1019 (threadObj == nullptr || !java_lang_Thread::is_daemon(threadObj))) {
1020 _number_of_non_daemon_threads++;
1021 daemon = false;
1022 }
1023
1024 ThreadService::add_thread(p, daemon);
1025
1026 // Maintain fast thread list
1027 ThreadsSMRSupport::add_thread(p);
1028
1029 // Increase the ObjectMonitor ceiling for the new thread.
1030 ObjectSynchronizer::inc_in_use_list_ceiling();
1031
1032 // Possible GC point.
1033 Events::log(Thread::current(), "Thread added: " INTPTR_FORMAT, p2i(p));
1034
1035 // Make new thread known to active EscapeBarrier
1036 EscapeBarrier::thread_added(p);
1037 }
1038
1039 void Threads::remove(JavaThread* p, bool is_daemon) {
1040 // Extra scope needed for Thread_lock, so we can check
1041 // that we do not remove thread without safepoint code notice
1042 {
1043 ConditionalMutexLocker throttle_ml(ThreadsLockThrottle_lock, UseThreadsLockThrottleLock);
1044 MonitorLocker ml(Threads_lock);
1045
1046 if (ThreadIdTable::is_initialized()) {
1047 // This cleanup must be done before the current thread's GC barrier
1048 // is detached since we need to touch the threadObj oop.
1049 jlong tid = SharedRuntime::get_java_tid(p);
1050 ThreadIdTable::remove_thread(tid);
1051 }
1052
1053 // BarrierSet state must be destroyed after the last thread transition
1054 // before the thread terminates. Thread transitions result in calls to
1055 // StackWatermarkSet::on_safepoint(), which performs GC processing,
1056 // requiring the GC state to be alive.
1057 BarrierSet::barrier_set()->on_thread_detach(p);
1058 if (p->is_exiting()) {
1059 // If we got here via JavaThread::exit(), then we remember that the
1060 // thread's GC barrier has been detached. We don't do this when we get
1061 // here from another path, e.g., cleanup_failed_attach_current_thread().
1062 p->set_terminated(JavaThread::_thread_gc_barrier_detached);
1063 }
1064
1065 assert(ThreadsSMRSupport::get_java_thread_list()->includes(p), "p must be present");
1066
1067 // Maintain fast thread list
1068 ThreadsSMRSupport::remove_thread(p);
1069
1070 _number_of_threads--;
1071 if (!is_daemon) {
1072 _number_of_non_daemon_threads--;
1073
1074 // If this is the last non-daemon thread then we need to do
1075 // a notify on the Threads_lock so a thread waiting
1076 // on destroy_vm will wake up. But that thread could be a daemon
1077 // or non-daemon, so we notify for both the 0 and 1 case.
1078 if (number_of_non_daemon_threads() <= 1) {
1079 ml.notify_all();
1080 }
1081 }
1082 ThreadService::remove_thread(p, is_daemon);
1083
1084 // Make sure that safepoint code disregard this thread. This is needed since
1085 // the thread might mess around with locks after this point. This can cause it
1086 // to do callbacks into the safepoint code. However, the safepoint code is not aware
1087 // of this thread since it is removed from the queue.
1088 p->set_terminated(JavaThread::_thread_terminated);
1089
1090 // Notify threads waiting in EscapeBarriers
1091 EscapeBarrier::thread_removed(p);
1092 } // unlock Threads_lock and ThreadsLockThrottle_lock
1093
1094 // Reduce the ObjectMonitor ceiling for the exiting thread.
1095 ObjectSynchronizer::dec_in_use_list_ceiling();
1096
1097 // Since Events::log uses a lock, we grab it outside the Threads_lock
1098 Events::log(Thread::current(), "Thread exited: " INTPTR_FORMAT, p2i(p));
1099 }
1100
1101 // Operations on the Threads list for GC. These are not explicitly locked,
1102 // but the garbage collector must provide a safe context for them to run.
1103 // In particular, these things should never be called when the Threads_lock
1104 // is held by some other thread. (Note: the Safepoint abstraction also
1105 // uses the Threads_lock to guarantee this property. It also makes sure that
1106 // all threads gets blocked when exiting or starting).
1107
1108 void Threads::oops_do(OopClosure* f, NMethodClosure* cf) {
1109 ALL_JAVA_THREADS(p) {
1110 p->oops_do(f, cf);
1111 }
1112 VMThread::vm_thread()->oops_do(f, cf);
1113 }
1114
1115 void Threads::change_thread_claim_token() {
1116 if (++_thread_claim_token == 0) {
1117 // On overflow of the token counter, there is a risk of future
1118 // collisions between a new global token value and a stale token
1119 // for a thread, because not all iterations visit all threads.
1120 // (Though it's pretty much a theoretical concern for non-trivial
1121 // token counter sizes.) To deal with the possibility, reset all
1122 // the thread tokens to zero on global token overflow.
1123 struct ResetClaims : public ThreadClosure {
1124 virtual void do_thread(Thread* t) {
1125 t->claim_threads_do(false, 0);
1126 }
1127 } reset_claims;
1128 Threads::threads_do(&reset_claims);
1129 // On overflow, update the global token to non-zero, to
1130 // avoid the special "never claimed" initial thread value.
1131 _thread_claim_token = 1;
1132 }
1133 }
1134
1135 #ifdef ASSERT
1136 static void assert_thread_claimed(const char* kind, Thread* t, uintx expected) {
1137 const uintx token = t->threads_do_token();
1138 assert(token == expected,
1139 "%s " PTR_FORMAT " has incorrect value " UINTX_FORMAT " != "
1140 UINTX_FORMAT, kind, p2i(t), token, expected);
1141 }
1142
1143 void Threads::assert_all_threads_claimed() {
1144 ALL_JAVA_THREADS(p) {
1145 assert_thread_claimed("JavaThread", p, _thread_claim_token);
1146 }
1147
1148 struct NJTClaimedVerifierClosure : public ThreadClosure {
1149 uintx _thread_claim_token;
1150
1151 NJTClaimedVerifierClosure(uintx thread_claim_token) : ThreadClosure(), _thread_claim_token(thread_claim_token) { }
1152
1153 virtual void do_thread(Thread* thread) override {
1154 assert_thread_claimed("Non-JavaThread", VMThread::vm_thread(), _thread_claim_token);
1155 }
1156 } tc(_thread_claim_token);
1157
1158 non_java_threads_do(&tc);
1159 }
1160 #endif // ASSERT
1161
1162 class ParallelOopsDoThreadClosure : public ThreadClosure {
1163 private:
1164 OopClosure* _f;
1165 NMethodClosure* _cf;
1166 public:
1167 ParallelOopsDoThreadClosure(OopClosure* f, NMethodClosure* cf) : _f(f), _cf(cf) {}
1168 void do_thread(Thread* t) {
1169 t->oops_do(_f, _cf);
1170 }
1171 };
1172
1173 void Threads::possibly_parallel_oops_do(bool is_par, OopClosure* f, NMethodClosure* cf) {
1174 ParallelOopsDoThreadClosure tc(f, cf);
1175 possibly_parallel_threads_do(is_par, &tc);
1176 }
1177
1178 void Threads::metadata_do(MetadataClosure* f) {
1179 ALL_JAVA_THREADS(p) {
1180 p->metadata_do(f);
1181 }
1182 }
1183
1184 class ThreadHandlesClosure : public ThreadClosure {
1185 void (*_f)(Metadata*);
1186 public:
1187 ThreadHandlesClosure(void f(Metadata*)) : _f(f) {}
1188 virtual void do_thread(Thread* thread) {
1189 thread->metadata_handles_do(_f);
1190 }
1191 };
1192
1193 void Threads::metadata_handles_do(void f(Metadata*)) {
1194 // Only walk the Handles in Thread.
1195 ThreadHandlesClosure handles_closure(f);
1196 threads_do(&handles_closure);
1197 }
1198
1199 #if INCLUDE_JVMTI
1200 // Get Java threads that are waiting to enter or re-enter the specified monitor.
1201 // Java threads that are executing mounted virtual threads are not included.
1202 GrowableArray<JavaThread*>* Threads::get_pending_threads(ThreadsList * t_list,
1203 int count,
1204 address monitor) {
1205 assert(Thread::current()->is_VM_thread(), "Must be the VM thread");
1206 GrowableArray<JavaThread*>* result = new GrowableArray<JavaThread*>(count);
1207
1208 int i = 0;
1209 for (JavaThread* p : *t_list) {
1210 if (!p->can_call_java()) continue;
1211
1212 oop thread_oop = JvmtiEnvBase::get_vthread_or_thread_oop(p);
1213 if (thread_oop->is_a(vmClasses::BaseVirtualThread_klass())) {
1214 continue;
1215 }
1216 // The first stage of async deflation does not affect any field
1217 // used by this comparison so the ObjectMonitor* is usable here.
1218 address pending = (address)p->current_pending_monitor();
1219 address waiting = (address)p->current_waiting_monitor();
1220 // do not include virtual threads to the list
1221 jint state = JvmtiEnvBase::get_thread_state(thread_oop, p);
1222 if (pending == monitor || (waiting == monitor &&
1223 (state & JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER))
1224 ) { // found a match
1225 if (i < count) result->append(p); // save the first count matches
1226 i++;
1227 }
1228 }
1229
1230 return result;
1231 }
1232 #endif // INCLUDE_JVMTI
1233
1234 JavaThread *Threads::owning_thread_from_monitor_owner(ThreadsList * t_list,
1235 address owner) {
1236 assert(LockingMode != LM_LIGHTWEIGHT, "Not with new lightweight locking");
1237 // null owner means not locked so we can skip the search
1238 if (owner == nullptr) return nullptr;
1239
1240 for (JavaThread* p : *t_list) {
1241 // first, see if owner is the address of a Java thread
1242 if (owner == (address)p) return p;
1243 }
1244
1245 // Cannot assert on lack of success here since this function may be
1246 // used by code that is trying to report useful problem information
1247 // like deadlock detection.
1248 if (LockingMode == LM_MONITOR) return nullptr;
1249
1250 // If we didn't find a matching Java thread and we didn't force use of
1251 // heavyweight monitors, then the owner is the stack address of the
1252 // Lock Word in the owning Java thread's stack.
1253 //
1254 JavaThread* the_owner = nullptr;
1255 for (JavaThread* q : *t_list) {
1256 if (q->is_lock_owned(owner)) {
1257 the_owner = q;
1258 break;
1259 }
1260 }
1261
1262 // cannot assert on lack of success here; see above comment
1263 return the_owner;
1264 }
1265
1266 JavaThread* Threads::owning_thread_from_object(ThreadsList * t_list, oop obj) {
1267 assert(LockingMode == LM_LIGHTWEIGHT, "Only with new lightweight locking");
1268 for (JavaThread* q : *t_list) {
1269 // Need to start processing before accessing oops in the thread.
1270 StackWatermark* watermark = StackWatermarkSet::get(q, StackWatermarkKind::gc);
1271 if (watermark != nullptr) {
1272 watermark->start_processing();
1273 }
1274
1275 if (q->lock_stack().contains(obj)) {
1276 return q;
1277 }
1278 }
1279 return nullptr;
1280 }
1281
1282 JavaThread* Threads::owning_thread_from_monitor(ThreadsList* t_list, ObjectMonitor* monitor) {
1283 if (LockingMode == LM_LIGHTWEIGHT) {
1284 if (monitor->is_owner_anonymous()) {
1285 return owning_thread_from_object(t_list, monitor->object());
1286 } else {
1287 Thread* owner = reinterpret_cast<Thread*>(monitor->owner());
1288 assert(owner == nullptr || owner->is_Java_thread(), "only JavaThreads own monitors");
1289 return reinterpret_cast<JavaThread*>(owner);
1290 }
1291 } else {
1292 address owner = (address)monitor->owner();
1293 return owning_thread_from_monitor_owner(t_list, owner);
1294 }
1295 }
1296
1297 class PrintOnClosure : public ThreadClosure {
1298 private:
1299 outputStream* _st;
1300
1301 public:
1302 PrintOnClosure(outputStream* st) :
1303 _st(st) {}
1304
1305 virtual void do_thread(Thread* thread) {
1306 if (thread != nullptr) {
1307 thread->print_on(_st);
1308 _st->cr();
1309 }
1310 }
1311 };
1312
1313 // Threads::print_on() is called at safepoint by VM_PrintThreads operation.
1314 void Threads::print_on(outputStream* st, bool print_stacks,
1315 bool internal_format, bool print_concurrent_locks,
1316 bool print_extended_info) {
1317 char buf[32];
1318 st->print_raw_cr(os::local_time_string(buf, sizeof(buf)));
1319
1320 st->print_cr("Full thread dump %s (%s %s):",
1321 VM_Version::vm_name(),
1322 VM_Version::vm_release(),
1323 VM_Version::vm_info_string());
1324 st->cr();
1325
1326 #if INCLUDE_SERVICES
1327 // Dump concurrent locks
1328 ConcurrentLocksDump concurrent_locks;
1329 if (print_concurrent_locks) {
1330 concurrent_locks.dump_at_safepoint();
1331 }
1332 #endif // INCLUDE_SERVICES
1333
1334 ThreadsSMRSupport::print_info_on(st);
1335 st->cr();
1336
1337 ALL_JAVA_THREADS(p) {
1338 ResourceMark rm;
1339 p->print_on(st, print_extended_info);
1340 if (print_stacks) {
1341 if (internal_format) {
1342 p->trace_stack();
1343 } else {
1344 p->print_stack_on(st);
1345 const oop thread_oop = p->threadObj();
1346 if (thread_oop != nullptr) {
1347 if (p->is_vthread_mounted()) {
1348 const oop vt = p->vthread();
1349 assert(vt != nullptr, "vthread should not be null when vthread is mounted");
1350 // JavaThread._vthread can refer to the carrier thread. Print only if _vthread refers to a virtual thread.
1351 if (vt != thread_oop) {
1352 st->print_cr(" Mounted virtual thread #" INT64_FORMAT, (int64_t)java_lang_Thread::thread_id(vt));
1353 p->print_vthread_stack_on(st);
1354 }
1355 }
1356 }
1357 }
1358 }
1359 st->cr();
1360 #if INCLUDE_SERVICES
1361 if (print_concurrent_locks) {
1362 concurrent_locks.print_locks_on(p, st);
1363 }
1364 #endif // INCLUDE_SERVICES
1365 }
1366
1367 PrintOnClosure cl(st);
1368 non_java_threads_do(&cl);
1369
1370 st->flush();
1371 }
1372
1373 void Threads::print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
1374 int buflen, bool* found_current) {
1375 if (this_thread != nullptr) {
1376 bool is_current = (current == this_thread);
1377 *found_current = *found_current || is_current;
1378 st->print("%s", is_current ? "=>" : " ");
1379
1380 st->print(PTR_FORMAT, p2i(this_thread));
1381 st->print(" ");
1382 this_thread->print_on_error(st, buf, buflen);
1383 st->cr();
1384 }
1385 }
1386
1387 class PrintOnErrorClosure : public ThreadClosure {
1388 outputStream* _st;
1389 Thread* _current;
1390 char* _buf;
1391 int _buflen;
1392 bool* _found_current;
1393 unsigned _num_printed;
1394 public:
1395 PrintOnErrorClosure(outputStream* st, Thread* current, char* buf,
1396 int buflen, bool* found_current) :
1397 _st(st), _current(current), _buf(buf), _buflen(buflen), _found_current(found_current),
1398 _num_printed(0) {}
1399
1400 virtual void do_thread(Thread* thread) {
1401 _num_printed++;
1402 Threads::print_on_error(thread, _st, _current, _buf, _buflen, _found_current);
1403 }
1404
1405 unsigned num_printed() const { return _num_printed; }
1406 };
1407
1408 // Threads::print_on_error() is called by fatal error handler. It's possible
1409 // that VM is not at safepoint and/or current thread is inside signal handler.
1410 // Don't print stack trace, as the stack may not be walkable. Don't allocate
1411 // memory (even in resource area), it might deadlock the error handler.
1412 void Threads::print_on_error(outputStream* st, Thread* current, char* buf,
1413 int buflen) {
1414 ThreadsSMRSupport::print_info_on(st);
1415 st->cr();
1416
1417 bool found_current = false;
1418 st->print_cr("Java Threads: ( => current thread )");
1419 unsigned num_java = 0;
1420 ALL_JAVA_THREADS(thread) {
1421 print_on_error(thread, st, current, buf, buflen, &found_current);
1422 num_java++;
1423 }
1424 st->print_cr("Total: %u", num_java);
1425 st->cr();
1426
1427 st->print_cr("Other Threads:");
1428 unsigned num_other = ((VMThread::vm_thread() != nullptr) ? 1 : 0) +
1429 ((WatcherThread::watcher_thread() != nullptr) ? 1 : 0) +
1430 ((AsyncLogWriter::instance() != nullptr) ? 1 : 0);
1431 print_on_error(VMThread::vm_thread(), st, current, buf, buflen, &found_current);
1432 print_on_error(WatcherThread::watcher_thread(), st, current, buf, buflen, &found_current);
1433 print_on_error(AsyncLogWriter::instance(), st, current, buf, buflen, &found_current);
1434
1435 if (Universe::heap() != nullptr) {
1436 PrintOnErrorClosure print_closure(st, current, buf, buflen, &found_current);
1437 Universe::heap()->gc_threads_do(&print_closure);
1438 num_other += print_closure.num_printed();
1439 }
1440
1441 if (!found_current) {
1442 st->cr();
1443 st->print("=>" PTR_FORMAT " (exited) ", p2i(current));
1444 current->print_on_error(st, buf, buflen);
1445 num_other++;
1446 st->cr();
1447 }
1448 st->print_cr("Total: %u", num_other);
1449 st->cr();
1450
1451 st->print_cr("Threads with active compile tasks:");
1452 unsigned num = print_threads_compiling(st, buf, buflen);
1453 st->print_cr("Total: %u", num);
1454 }
1455
1456 unsigned Threads::print_threads_compiling(outputStream* st, char* buf, int buflen, bool short_form) {
1457 unsigned num = 0;
1458 ALL_JAVA_THREADS(thread) {
1459 if (thread->is_Compiler_thread()) {
1460 CompilerThread* ct = (CompilerThread*) thread;
1461
1462 // Keep task in local variable for null check.
1463 // ct->_task might be set to null by concurring compiler thread
1464 // because it completed the compilation. The task is never freed,
1465 // though, just returned to a free list.
1466 CompileTask* task = ct->task();
1467 if (task != nullptr) {
1468 thread->print_name_on_error(st, buf, buflen);
1469 st->print(" ");
1470 task->print(st, nullptr, short_form, true);
1471 num++;
1472 }
1473 }
1474 }
1475 return num;
1476 }
1477
1478 void Threads::verify() {
1479 ALL_JAVA_THREADS(p) {
1480 p->verify();
1481 }
1482 VMThread* thread = VMThread::vm_thread();
1483 if (thread != nullptr) thread->verify();
1484 }