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