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_IdentityException(), CHECK);
404 initialize_class(vmSymbols::java_lang_IllegalArgumentException(), CHECK);
405 }
406
407 void Threads::initialize_jsr292_core_classes(TRAPS) {
408 TraceTime timer("Initialize java.lang.invoke classes", TRACETIME_LOG(Info, startuptime));
409
410 initialize_class(vmSymbols::java_lang_invoke_MethodHandle(), CHECK);
411 initialize_class(vmSymbols::java_lang_invoke_ResolvedMethodName(), CHECK);
412 initialize_class(vmSymbols::java_lang_invoke_MemberName(), CHECK);
413 initialize_class(vmSymbols::java_lang_invoke_MethodHandleNatives(), CHECK);
414 }
415
416 jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) {
417 extern void JDK_Version_init();
418
419 // Preinitialize version info.
420 VM_Version::early_initialize();
421
422 // Check version
423 if (!is_supported_jni_version(args->version)) return JNI_EVERSION;
424
425 // Initialize library-based TLS
426 ThreadLocalStorage::init();
427
428 // Initialize the output stream module
429 ostream_init();
430
431 // Process java launcher properties.
432 Arguments::process_sun_java_launcher_properties(args);
433
434 // Initialize the os module
435 os::init();
436
437 MACOS_AARCH64_ONLY(os::current_thread_enable_wx(WXWrite));
438
439 // Record VM creation timing statistics
440 TraceVmCreationTime create_vm_timer;
441 create_vm_timer.start();
442
443 // Initialize system properties.
444 Arguments::init_system_properties();
445
446 // So that JDK version can be used as a discriminator when parsing arguments
447 JDK_Version_init();
448
449 // Update/Initialize System properties after JDK version number is known
450 Arguments::init_version_specific_system_properties();
451
452 // Make sure to initialize log configuration *before* parsing arguments
453 LogConfiguration::initialize(create_vm_timer.begin_time());
454
455 // Parse arguments
456 // Note: this internally calls os::init_container_support()
457 jint parse_result = Arguments::parse(args);
458 if (parse_result != JNI_OK) return parse_result;
459
460 // Initialize NMT right after argument parsing to keep the pre-NMT-init window small.
461 MemTracker::initialize();
462
463 os::init_before_ergo();
464
465 jint ergo_result = Arguments::apply_ergo();
466 if (ergo_result != JNI_OK) return ergo_result;
467
468 // Final check of all ranges after ergonomics which may change values.
469 if (!JVMFlagLimit::check_all_ranges()) {
470 return JNI_EINVAL;
471 }
472
473 // Final check of all 'AfterErgo' constraints after ergonomics which may change values.
474 bool constraint_result = JVMFlagLimit::check_all_constraints(JVMFlagConstraintPhase::AfterErgo);
475 if (!constraint_result) {
476 return JNI_EINVAL;
477 }
478
479 if (PauseAtStartup) {
480 os::pause();
481 }
482
483 HOTSPOT_VM_INIT_BEGIN();
484
485 // Timing (must come after argument parsing)
486 TraceTime timer("Create VM", TRACETIME_LOG(Info, startuptime));
487
488 // Initialize the os module after parsing the args
489 jint os_init_2_result = os::init_2();
490 if (os_init_2_result != JNI_OK) return os_init_2_result;
491
492 #ifdef CAN_SHOW_REGISTERS_ON_ASSERT
493 // Initialize assert poison page mechanism.
494 if (ShowRegistersOnAssert) {
495 initialize_assert_poison();
496 }
497 #endif // CAN_SHOW_REGISTERS_ON_ASSERT
498
499 SafepointMechanism::initialize();
500
501 jint adjust_after_os_result = Arguments::adjust_after_os();
502 if (adjust_after_os_result != JNI_OK) return adjust_after_os_result;
503
504 // Initialize output stream logging
505 ostream_init_log();
506
507 // Launch -agentlib/-agentpath and converted -Xrun agents
508 JvmtiAgentList::load_agents();
509
510 // Initialize Threads state
511 _number_of_threads = 0;
512 _number_of_non_daemon_threads = 0;
513
514 // Initialize global data structures and create system classes in heap
515 vm_init_globals();
516
517 #if INCLUDE_JVMCI
518 if (JVMCICounterSize > 0) {
519 JavaThread::_jvmci_old_thread_counters = NEW_C_HEAP_ARRAY(jlong, JVMCICounterSize, mtJVMCI);
520 memset(JavaThread::_jvmci_old_thread_counters, 0, sizeof(jlong) * JVMCICounterSize);
521 } else {
522 JavaThread::_jvmci_old_thread_counters = nullptr;
523 }
524 #endif // INCLUDE_JVMCI
525
526 // Initialize OopStorage for threadObj
527 JavaThread::_thread_oop_storage = OopStorageSet::create_strong("Thread OopStorage", mtThread);
528
529 // Attach the main thread to this os thread
530 JavaThread* main_thread = new JavaThread();
531 main_thread->set_thread_state(_thread_in_vm);
532 main_thread->initialize_thread_current();
533 // must do this before set_active_handles
534 main_thread->record_stack_base_and_size();
535 main_thread->register_thread_stack_with_NMT();
536 main_thread->set_active_handles(JNIHandleBlock::allocate_block());
537 MACOS_AARCH64_ONLY(main_thread->init_wx());
538
539 if (!Thread::set_as_starting_thread(main_thread)) {
540 vm_shutdown_during_initialization(
541 "Failed necessary internal allocation. Out of swap space");
542 main_thread->smr_delete();
543 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
544 return JNI_ENOMEM;
545 }
546
547 JFR_ONLY(Jfr::initialize_main_thread(main_thread);)
548
549 // Enable guard page *after* os::create_main_thread(), otherwise it would
550 // crash Linux VM, see notes in os_linux.cpp.
551 main_thread->stack_overflow_state()->create_stack_guard_pages();
552
553 // Initialize Java-Level synchronization subsystem
554 ObjectMonitor::Initialize();
555 ObjectSynchronizer::initialize();
556
557 // Initialize global modules
558 jint status = init_globals();
559 if (status != JNI_OK) {
560 main_thread->smr_delete();
561 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
562 return status;
563 }
564
565 // Create WatcherThread as soon as we can since we need it in case
566 // of hangs during error reporting.
567 WatcherThread::start();
568
569 // Add main_thread to threads list to finish barrier setup with
570 // on_thread_attach. Should be before starting to build Java objects in
571 // init_globals2, which invokes barriers.
572 {
573 MutexLocker mu(Threads_lock);
574 Threads::add(main_thread);
575 }
576
577 status = init_globals2();
578 if (status != JNI_OK) {
579 Threads::remove(main_thread, false);
580 // It is possible that we managed to fully initialize Universe but have then
581 // failed by throwing an exception. In that case our caller JNI_CreateJavaVM
582 // will want to report it, so we can't delete the main thread.
583 if (!main_thread->has_pending_exception()) {
584 main_thread->smr_delete();
585 }
586 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
587 return status;
588 }
589
590 JFR_ONLY(Jfr::on_create_vm_1();)
591
592 // Should be done after the heap is fully created
593 main_thread->cache_global_variables();
594
595 // Any JVMTI raw monitors entered in onload will transition into
596 // real raw monitor. VM is setup enough here for raw monitor enter.
597 JvmtiExport::transition_pending_onload_raw_monitors();
598
599 // Create the VMThread
600 { TraceTime timer("Start VMThread", TRACETIME_LOG(Info, startuptime));
601
602 VMThread::create();
603 VMThread* vmthread = VMThread::vm_thread();
604
605 if (!os::create_thread(vmthread, os::vm_thread)) {
606 vm_exit_during_initialization("Cannot create VM thread. "
607 "Out of system resources.");
608 }
609
610 // Wait for the VM thread to become ready, and VMThread::run to initialize
611 // Monitors can have spurious returns, must always check another state flag
612 {
613 MonitorLocker ml(Notify_lock);
614 os::start_thread(vmthread);
615 while (!vmthread->is_running()) {
616 ml.wait();
617 }
618 }
619 }
620
621 assert(Universe::is_fully_initialized(), "not initialized");
622 if (VerifyDuringStartup) {
623 // Make sure we're starting with a clean slate.
624 VM_Verify verify_op;
625 VMThread::execute(&verify_op);
626 }
627
628 // We need this to update the java.vm.info property in case any flags used
629 // to initially define it have been changed. This is needed for both CDS
630 // since UseSharedSpaces may be changed after java.vm.info
631 // is initially computed. See Abstract_VM_Version::vm_info_string().
632 // This update must happen before we initialize the java classes, but
633 // after any initialization logic that might modify the flags.
634 Arguments::update_vm_info_property(VM_Version::vm_info_string());
635
636 JavaThread* THREAD = JavaThread::current(); // For exception macros.
637 HandleMark hm(THREAD);
638
639 // Always call even when there are not JVMTI environments yet, since environments
640 // may be attached late and JVMTI must track phases of VM execution
641 JvmtiExport::enter_early_start_phase();
642
643 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
644 JvmtiExport::post_early_vm_start();
645
646 // Launch -Xrun agents early if EagerXrunInit is set
647 if (EagerXrunInit) {
648 JvmtiAgentList::load_xrun_agents();
649 }
650
651 initialize_java_lang_classes(main_thread, CHECK_JNI_ERR);
652
653 quicken_jni_functions();
654
655 // No more stub generation allowed after that point.
656 StubCodeDesc::freeze();
657
658 // Set flag that basic initialization has completed. Used by exceptions and various
659 // debug stuff, that does not work until all basic classes have been initialized.
660 set_init_completed();
661
662 LogConfiguration::post_initialize();
663 Metaspace::post_initialize();
664 MutexLockerImpl::post_initialize();
665
666 HOTSPOT_VM_INIT_END();
667
668 // record VM initialization completion time
669 #if INCLUDE_MANAGEMENT
670 Management::record_vm_init_completed();
671 #endif // INCLUDE_MANAGEMENT
672
673 log_info(os)("Initialized VM with process ID %d", os::current_process_id());
674
675 if (!FLAG_IS_DEFAULT(CreateCoredumpOnCrash) && CreateCoredumpOnCrash) {
676 char buffer[2*JVM_MAXPATHLEN];
677 os::check_core_dump_prerequisites(buffer, sizeof(buffer), true);
678 }
679
680 // Signal Dispatcher needs to be started before VMInit event is posted
681 os::initialize_jdk_signal_support(CHECK_JNI_ERR);
682
683 // Start Attach Listener if +StartAttachListener or it can't be started lazily
684 if (!DisableAttachMechanism) {
685 AttachListener::vm_start();
686 if (StartAttachListener || AttachListener::init_at_startup()) {
687 AttachListener::init();
688 }
689 }
690
691 // Launch -Xrun agents if EagerXrunInit is not set.
692 if (!EagerXrunInit) {
693 JvmtiAgentList::load_xrun_agents();
694 }
695
696 Arena::start_chunk_pool_cleaner_task();
697
698 // Start the service thread
699 // The service thread enqueues JVMTI deferred events and does various hashtable
700 // and other cleanups. Needs to start before the compilers start posting events.
701 ServiceThread::initialize();
702
703 // Start the monitor deflation thread:
704 MonitorDeflationThread::initialize();
705
706 // initialize compiler(s)
707 #if defined(COMPILER1) || COMPILER2_OR_JVMCI
708 bool init_compilation = true;
709 #if INCLUDE_JVMCI
710 bool force_JVMCI_initialization = false;
711 if (EnableJVMCI) {
712 // Initialize JVMCI eagerly when it is explicitly requested.
713 // Or when JVMCILibDumpJNIConfig or JVMCIPrintProperties is enabled.
714 force_JVMCI_initialization = EagerJVMCI || JVMCIPrintProperties || JVMCILibDumpJNIConfig;
715 if (!force_JVMCI_initialization && UseJVMCICompiler && !UseJVMCINativeLibrary && (!UseInterpreter || !BackgroundCompilation)) {
716 // Force initialization of jarjvmci otherwise requests for blocking
717 // compilations will not actually block until jarjvmci is initialized.
718 force_JVMCI_initialization = true;
719 }
720 if (JVMCIPrintProperties || JVMCILibDumpJNIConfig) {
721 // Both JVMCILibDumpJNIConfig and JVMCIPrintProperties exit the VM
722 // so compilation should be disabled. This prevents dumping or
723 // printing from happening more than once.
724 init_compilation = false;
725 }
726 }
727 #endif
728 if (init_compilation) {
729 CompileBroker::compilation_init(CHECK_JNI_ERR);
730 }
731 #endif
732
733 // Start string deduplication thread if requested.
734 if (StringDedup::is_enabled()) {
735 StringDedup::start();
736 }
737
738 // Pre-initialize some JSR292 core classes to avoid deadlock during class loading.
739 // It is done after compilers are initialized, because otherwise compilations of
740 // signature polymorphic MH intrinsics can be missed
741 // (see SystemDictionary::find_method_handle_intrinsic).
742 initialize_jsr292_core_classes(CHECK_JNI_ERR);
743
744 // This will initialize the module system. Only java.base classes can be
745 // loaded until phase 2 completes
746 call_initPhase2(CHECK_JNI_ERR);
747
748 JFR_ONLY(Jfr::on_create_vm_2();)
749
750 // Always call even when there are not JVMTI environments yet, since environments
751 // may be attached late and JVMTI must track phases of VM execution
752 JvmtiExport::enter_start_phase();
753
754 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
755 JvmtiExport::post_vm_start();
756
757 // Final system initialization including security manager and system class loader
758 call_initPhase3(CHECK_JNI_ERR);
759
760 // cache the system and platform class loaders
761 SystemDictionary::compute_java_loaders(CHECK_JNI_ERR);
762
763 if (Continuations::enabled()) {
764 // Initialize Continuation class now so that failure to create enterSpecial/doYield
765 // special nmethods due to limited CodeCache size can be treated as a fatal error at
766 // startup with the proper message that CodeCache size is too small.
767 initialize_class(vmSymbols::jdk_internal_vm_Continuation(), CHECK_JNI_ERR);
768 }
769
770 #if INCLUDE_CDS
771 // capture the module path info from the ModuleEntryTable
772 ClassLoader::initialize_module_path(THREAD);
773 if (HAS_PENDING_EXCEPTION) {
774 java_lang_Throwable::print(PENDING_EXCEPTION, tty);
775 vm_exit_during_initialization("ClassLoader::initialize_module_path() failed unexpectedly");
776 }
777 #endif
778
779 #if INCLUDE_JVMCI
780 if (force_JVMCI_initialization) {
781 JVMCI::initialize_compiler(CHECK_JNI_ERR);
782 }
783 #endif
784
785 if (NativeHeapTrimmer::enabled()) {
786 NativeHeapTrimmer::initialize();
787 }
788
789 // Always call even when there are not JVMTI environments yet, since environments
790 // may be attached late and JVMTI must track phases of VM execution
791 JvmtiExport::enter_live_phase();
792
793 // Make perfmemory accessible
794 PerfMemory::set_accessible(true);
795
796 // Notify JVMTI agents that VM initialization is complete - nop if no agents.
797 JvmtiExport::post_vm_initialized();
798
799 JFR_ONLY(Jfr::on_create_vm_3();)
800
801 #if INCLUDE_MANAGEMENT
802 Management::initialize(THREAD);
803
804 if (HAS_PENDING_EXCEPTION) {
805 // management agent fails to start possibly due to
806 // configuration problem and is responsible for printing
807 // stack trace if appropriate. Simply exit VM.
808 vm_exit(1);
809 }
810 #endif // INCLUDE_MANAGEMENT
811
812 StatSampler::engage();
813 if (CheckJNICalls) JniPeriodicChecker::engage();
814
815 call_postVMInitHook(THREAD);
816 // The Java side of PostVMInitHook.run must deal with all
817 // exceptions and provide means of diagnosis.
818 if (HAS_PENDING_EXCEPTION) {
819 CLEAR_PENDING_EXCEPTION;
820 }
821
822 // Let WatcherThread run all registered periodic tasks now.
823 // NOTE: All PeriodicTasks should be registered by now. If they
824 // aren't, late joiners might appear to start slowly (we might
825 // take a while to process their first tick).
826 WatcherThread::run_all_tasks();
827
828 create_vm_timer.end();
829 #ifdef ASSERT
830 _vm_complete = true;
831 #endif
832
833 if (CDSConfig::is_dumping_static_archive()) {
834 MetaspaceShared::preload_and_dump(CHECK_JNI_ERR);
835 }
836
837 if (log_is_enabled(Info, perf, class, link)) {
838 LogStreamHandle(Info, perf, class, link) log;
839 log.print_cr("At VM initialization completion:");
840 ClassLoader::print_counters(&log);
841 }
842
843 return JNI_OK;
844 }
845
846 // Threads::destroy_vm() is normally called from jni_DestroyJavaVM() when
847 // the program falls off the end of main(). Another VM exit path is through
848 // vm_exit(), when the program calls System.exit() to return a value, or when
849 // there is a serious error in VM.
850 // These two separate shutdown paths are not exactly the same, but they share
851 // Shutdown.shutdown() at Java level and before_exit() and VM_Exit op at VM level.
852 //
853 // Shutdown sequence:
854 // + Shutdown native memory tracking if it is on
855 // + Wait until we are the last non-daemon thread to execute
856 // <-- every thing is still working at this moment -->
857 // + Call java.lang.Shutdown.shutdown(), which will invoke Java level
858 // shutdown hooks
859 // + Call before_exit(), prepare for VM exit
860 // > run VM level shutdown hooks (they are registered through JVM_OnExit(),
861 // currently the only user of this mechanism is File.deleteOnExit())
862 // > stop StatSampler, watcher thread,
863 // post thread end and vm death events to JVMTI,
864 // stop signal thread
865 // + Call JavaThread::exit(), it will:
866 // > release JNI handle blocks, remove stack guard pages
867 // > remove this thread from Threads list
868 // <-- no more Java code from this thread after this point -->
869 // + Stop VM thread, it will bring the remaining VM to a safepoint and stop
870 // the compiler threads at safepoint
871 // <-- do not use anything that could get blocked by Safepoint -->
872 // + Disable tracing at JNI/JVM barriers
873 // + Set _vm_exited flag for threads that are still running native code
874 // + Call exit_globals()
875 // > deletes tty
876 // > deletes PerfMemory resources
877 // + Delete this thread
878 // + Return to caller
879
880 void Threads::destroy_vm() {
881 JavaThread* thread = JavaThread::current();
882
883 #ifdef ASSERT
884 _vm_complete = false;
885 #endif
886 // Wait until we are the last non-daemon thread to execute, or
887 // if we are a daemon then wait until the last non-daemon thread has
888 // executed.
889 bool daemon = java_lang_Thread::is_daemon(thread->threadObj());
890 int expected = daemon ? 0 : 1;
891 {
892 MonitorLocker nu(Threads_lock);
893 while (Threads::number_of_non_daemon_threads() > expected)
894 // This wait should make safepoint checks, wait without a timeout.
895 nu.wait(0);
896 }
897
898 EventShutdown e;
899 if (e.should_commit()) {
900 e.set_reason("No remaining non-daemon Java threads");
901 e.commit();
902 }
903
904 // Hang forever on exit if we are reporting an error.
905 if (ShowMessageBoxOnError && VMError::is_error_reported()) {
906 os::infinite_sleep();
907 }
908 os::wait_for_keypress_at_exit();
909
910 // run Java level shutdown hooks
911 thread->invoke_shutdown_hooks();
912
913 before_exit(thread);
914
915 thread->exit(true);
916
917 // We are no longer on the main thread list but could still be in a
918 // secondary list where another thread may try to interact with us.
919 // So wait until all such interactions are complete before we bring
920 // the VM to the termination safepoint. Normally this would be done
921 // using thread->smr_delete() below where we delete the thread, but
922 // we can't call that after the termination safepoint is active as
923 // we will deadlock on the Threads_lock. Once all interactions are
924 // complete it is safe to directly delete the thread at any time.
925 ThreadsSMRSupport::wait_until_not_protected(thread);
926
927 // Stop VM thread.
928 {
929 // 4945125 The vm thread comes to a safepoint during exit.
930 // GC vm_operations can get caught at the safepoint, and the
931 // heap is unparseable if they are caught. Grab the Heap_lock
932 // to prevent this. The GC vm_operations will not be able to
933 // queue until after the vm thread is dead. After this point,
934 // we'll never emerge out of the safepoint before the VM exits.
935 // Assert that the thread is terminated so that acquiring the
936 // Heap_lock doesn't cause the terminated thread to participate in
937 // the safepoint protocol.
938
939 assert(thread->is_terminated(), "must be terminated here");
940 MutexLocker ml(Heap_lock);
941
942 VMThread::wait_for_vm_thread_exit();
943 assert(SafepointSynchronize::is_at_safepoint(), "VM thread should exit at Safepoint");
944 VMThread::destroy();
945 }
946
947 // Now, all Java threads are gone except daemon threads. Daemon threads
948 // running Java code or in VM are stopped by the Safepoint. However,
949 // daemon threads executing native code are still running. But they
950 // will be stopped at native=>Java/VM barriers. Note that we can't
951 // simply kill or suspend them, as it is inherently deadlock-prone.
952
953 VM_Exit::set_vm_exited();
954
955 // Clean up ideal graph printers after the VMThread has started
956 // the final safepoint which will block all the Compiler threads.
957 // Note that this Thread has already logically exited so the
958 // clean_up() function's use of a JavaThreadIteratorWithHandle
959 // would be a problem except set_vm_exited() has remembered the
960 // shutdown thread which is granted a policy exception.
961 #if defined(COMPILER2) && !defined(PRODUCT)
962 IdealGraphPrinter::clean_up();
963 #endif
964
965 notify_vm_shutdown();
966
967 // exit_globals() will delete tty
968 exit_globals();
969
970 // Deleting the shutdown thread here is safe. See comment on
971 // wait_until_not_protected() above.
972 delete thread;
973
974 #if INCLUDE_JVMCI
975 if (JVMCICounterSize > 0) {
976 FREE_C_HEAP_ARRAY(jlong, JavaThread::_jvmci_old_thread_counters);
977 }
978 #endif
979
980 LogConfiguration::finalize();
981 }
982
983
984 jboolean Threads::is_supported_jni_version_including_1_1(jint version) {
985 if (version == JNI_VERSION_1_1) return JNI_TRUE;
986 return is_supported_jni_version(version);
987 }
988
989
990 jboolean Threads::is_supported_jni_version(jint version) {
991 if (version == JNI_VERSION_1_2) return JNI_TRUE;
992 if (version == JNI_VERSION_1_4) return JNI_TRUE;
993 if (version == JNI_VERSION_1_6) return JNI_TRUE;
994 if (version == JNI_VERSION_1_8) return JNI_TRUE;
995 if (version == JNI_VERSION_9) return JNI_TRUE;
996 if (version == JNI_VERSION_10) return JNI_TRUE;
997 if (version == JNI_VERSION_19) return JNI_TRUE;
998 if (version == JNI_VERSION_20) return JNI_TRUE;
999 if (version == JNI_VERSION_21) return JNI_TRUE;
1000 if (version == JNI_VERSION_24) return JNI_TRUE;
1001 return JNI_FALSE;
1002 }
1003
1004 void Threads::add(JavaThread* p, bool force_daemon) {
1005 // The threads lock must be owned at this point
1006 assert(Threads_lock->owned_by_self(), "must have threads lock");
1007
1008 BarrierSet::barrier_set()->on_thread_attach(p);
1009
1010 // Once a JavaThread is added to the Threads list, smr_delete() has
1011 // to be used to delete it. Otherwise we can just delete it directly.
1012 p->set_on_thread_list();
1013
1014 _number_of_threads++;
1015 oop threadObj = p->threadObj();
1016 bool daemon = true;
1017 // Bootstrapping problem: threadObj can be null for initial
1018 // JavaThread (or for threads attached via JNI)
1019 if (!force_daemon &&
1020 (threadObj == nullptr || !java_lang_Thread::is_daemon(threadObj))) {
1021 _number_of_non_daemon_threads++;
1022 daemon = false;
1023 }
1024
1025 ThreadService::add_thread(p, daemon);
1026
1027 // Maintain fast thread list
1028 ThreadsSMRSupport::add_thread(p);
1029
1030 // Increase the ObjectMonitor ceiling for the new thread.
1031 ObjectSynchronizer::inc_in_use_list_ceiling();
1032
1033 // Possible GC point.
1034 Events::log(Thread::current(), "Thread added: " INTPTR_FORMAT, p2i(p));
1035
1036 // Make new thread known to active EscapeBarrier
1037 EscapeBarrier::thread_added(p);
1038 }
1039
1040 void Threads::remove(JavaThread* p, bool is_daemon) {
1041 // Extra scope needed for Thread_lock, so we can check
1042 // that we do not remove thread without safepoint code notice
1043 {
1044 ConditionalMutexLocker throttle_ml(ThreadsLockThrottle_lock, UseThreadsLockThrottleLock);
1045 MonitorLocker ml(Threads_lock);
1046
1047 if (ThreadIdTable::is_initialized()) {
1048 // This cleanup must be done before the current thread's GC barrier
1049 // is detached since we need to touch the threadObj oop.
1050 jlong tid = SharedRuntime::get_java_tid(p);
1051 ThreadIdTable::remove_thread(tid);
1052 }
1053
1054 // BarrierSet state must be destroyed after the last thread transition
1055 // before the thread terminates. Thread transitions result in calls to
1056 // StackWatermarkSet::on_safepoint(), which performs GC processing,
1057 // requiring the GC state to be alive.
1058 BarrierSet::barrier_set()->on_thread_detach(p);
1059 if (p->is_exiting()) {
1060 // If we got here via JavaThread::exit(), then we remember that the
1061 // thread's GC barrier has been detached. We don't do this when we get
1062 // here from another path, e.g., cleanup_failed_attach_current_thread().
1063 p->set_terminated(JavaThread::_thread_gc_barrier_detached);
1064 }
1065
1066 assert(ThreadsSMRSupport::get_java_thread_list()->includes(p), "p must be present");
1067
1068 // Maintain fast thread list
1069 ThreadsSMRSupport::remove_thread(p);
1070
1071 _number_of_threads--;
1072 if (!is_daemon) {
1073 _number_of_non_daemon_threads--;
1074
1075 // If this is the last non-daemon thread then we need to do
1076 // a notify on the Threads_lock so a thread waiting
1077 // on destroy_vm will wake up. But that thread could be a daemon
1078 // or non-daemon, so we notify for both the 0 and 1 case.
1079 if (number_of_non_daemon_threads() <= 1) {
1080 ml.notify_all();
1081 }
1082 }
1083 ThreadService::remove_thread(p, is_daemon);
1084
1085 // Make sure that safepoint code disregard this thread. This is needed since
1086 // the thread might mess around with locks after this point. This can cause it
1087 // to do callbacks into the safepoint code. However, the safepoint code is not aware
1088 // of this thread since it is removed from the queue.
1089 p->set_terminated(JavaThread::_thread_terminated);
1090
1091 // Notify threads waiting in EscapeBarriers
1092 EscapeBarrier::thread_removed(p);
1093 } // unlock Threads_lock and ThreadsLockThrottle_lock
1094
1095 // Reduce the ObjectMonitor ceiling for the exiting thread.
1096 ObjectSynchronizer::dec_in_use_list_ceiling();
1097
1098 // Since Events::log uses a lock, we grab it outside the Threads_lock
1099 Events::log(Thread::current(), "Thread exited: " INTPTR_FORMAT, p2i(p));
1100 }
1101
1102 // Operations on the Threads list for GC. These are not explicitly locked,
1103 // but the garbage collector must provide a safe context for them to run.
1104 // In particular, these things should never be called when the Threads_lock
1105 // is held by some other thread. (Note: the Safepoint abstraction also
1106 // uses the Threads_lock to guarantee this property. It also makes sure that
1107 // all threads gets blocked when exiting or starting).
1108
1109 void Threads::oops_do(OopClosure* f, NMethodClosure* cf) {
1110 ALL_JAVA_THREADS(p) {
1111 p->oops_do(f, cf);
1112 }
1113 VMThread::vm_thread()->oops_do(f, cf);
1114 }
1115
1116 void Threads::change_thread_claim_token() {
1117 if (++_thread_claim_token == 0) {
1118 // On overflow of the token counter, there is a risk of future
1119 // collisions between a new global token value and a stale token
1120 // for a thread, because not all iterations visit all threads.
1121 // (Though it's pretty much a theoretical concern for non-trivial
1122 // token counter sizes.) To deal with the possibility, reset all
1123 // the thread tokens to zero on global token overflow.
1124 struct ResetClaims : public ThreadClosure {
1125 virtual void do_thread(Thread* t) {
1126 t->claim_threads_do(false, 0);
1127 }
1128 } reset_claims;
1129 Threads::threads_do(&reset_claims);
1130 // On overflow, update the global token to non-zero, to
1131 // avoid the special "never claimed" initial thread value.
1132 _thread_claim_token = 1;
1133 }
1134 }
1135
1136 #ifdef ASSERT
1137 static void assert_thread_claimed(const char* kind, Thread* t, uintx expected) {
1138 const uintx token = t->threads_do_token();
1139 assert(token == expected,
1140 "%s " PTR_FORMAT " has incorrect value " UINTX_FORMAT " != "
1141 UINTX_FORMAT, kind, p2i(t), token, expected);
1142 }
1143
1144 void Threads::assert_all_threads_claimed() {
1145 ALL_JAVA_THREADS(p) {
1146 assert_thread_claimed("JavaThread", p, _thread_claim_token);
1147 }
1148
1149 struct NJTClaimedVerifierClosure : public ThreadClosure {
1150 uintx _thread_claim_token;
1151
1152 NJTClaimedVerifierClosure(uintx thread_claim_token) : ThreadClosure(), _thread_claim_token(thread_claim_token) { }
1153
1154 virtual void do_thread(Thread* thread) override {
1155 assert_thread_claimed("Non-JavaThread", VMThread::vm_thread(), _thread_claim_token);
1156 }
1157 } tc(_thread_claim_token);
1158
1159 non_java_threads_do(&tc);
1160 }
1161 #endif // ASSERT
1162
1163 class ParallelOopsDoThreadClosure : public ThreadClosure {
1164 private:
1165 OopClosure* _f;
1166 NMethodClosure* _cf;
1167 public:
1168 ParallelOopsDoThreadClosure(OopClosure* f, NMethodClosure* cf) : _f(f), _cf(cf) {}
1169 void do_thread(Thread* t) {
1170 t->oops_do(_f, _cf);
1171 }
1172 };
1173
1174 void Threads::possibly_parallel_oops_do(bool is_par, OopClosure* f, NMethodClosure* cf) {
1175 ParallelOopsDoThreadClosure tc(f, cf);
1176 possibly_parallel_threads_do(is_par, &tc);
1177 }
1178
1179 void Threads::metadata_do(MetadataClosure* f) {
1180 ALL_JAVA_THREADS(p) {
1181 p->metadata_do(f);
1182 }
1183 }
1184
1185 class ThreadHandlesClosure : public ThreadClosure {
1186 void (*_f)(Metadata*);
1187 public:
1188 ThreadHandlesClosure(void f(Metadata*)) : _f(f) {}
1189 virtual void do_thread(Thread* thread) {
1190 thread->metadata_handles_do(_f);
1191 }
1192 };
1193
1194 void Threads::metadata_handles_do(void f(Metadata*)) {
1195 // Only walk the Handles in Thread.
1196 ThreadHandlesClosure handles_closure(f);
1197 threads_do(&handles_closure);
1198 }
1199
1200 #if INCLUDE_JVMTI
1201 // Get Java threads that are waiting to enter or re-enter the specified monitor.
1202 // Java threads that are executing mounted virtual threads are not included.
1203 GrowableArray<JavaThread*>* Threads::get_pending_threads(ThreadsList * t_list,
1204 int count,
1205 address monitor) {
1206 assert(Thread::current()->is_VM_thread(), "Must be the VM thread");
1207 GrowableArray<JavaThread*>* result = new GrowableArray<JavaThread*>(count);
1208
1209 int i = 0;
1210 for (JavaThread* p : *t_list) {
1211 if (!p->can_call_java()) continue;
1212
1213 oop thread_oop = JvmtiEnvBase::get_vthread_or_thread_oop(p);
1214 if (thread_oop->is_a(vmClasses::BaseVirtualThread_klass())) {
1215 continue;
1216 }
1217 // The first stage of async deflation does not affect any field
1218 // used by this comparison so the ObjectMonitor* is usable here.
1219 address pending = (address)p->current_pending_monitor();
1220 address waiting = (address)p->current_waiting_monitor();
1221 // do not include virtual threads to the list
1222 jint state = JvmtiEnvBase::get_thread_state(thread_oop, p);
1223 if (pending == monitor || (waiting == monitor &&
1224 (state & JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER))
1225 ) { // found a match
1226 if (i < count) result->append(p); // save the first count matches
1227 i++;
1228 }
1229 }
1230
1231 return result;
1232 }
1233 #endif // INCLUDE_JVMTI
1234
1235 JavaThread *Threads::owning_thread_from_monitor_owner(ThreadsList * t_list,
1236 address owner) {
1237 assert(LockingMode != LM_LIGHTWEIGHT, "Not with new lightweight locking");
1238 // null owner means not locked so we can skip the search
1239 if (owner == nullptr) return nullptr;
1240
1241 for (JavaThread* p : *t_list) {
1242 // first, see if owner is the address of a Java thread
1243 if (owner == (address)p) return p;
1244 }
1245
1246 // Cannot assert on lack of success here since this function may be
1247 // used by code that is trying to report useful problem information
1248 // like deadlock detection.
1249 if (LockingMode == LM_MONITOR) return nullptr;
1250
1251 // If we didn't find a matching Java thread and we didn't force use of
1252 // heavyweight monitors, then the owner is the stack address of the
1253 // Lock Word in the owning Java thread's stack.
1254 //
1255 JavaThread* the_owner = nullptr;
1256 for (JavaThread* q : *t_list) {
1257 if (q->is_lock_owned(owner)) {
1258 the_owner = q;
1259 break;
1260 }
1261 }
1262
1263 // cannot assert on lack of success here; see above comment
1264 return the_owner;
1265 }
1266
1267 JavaThread* Threads::owning_thread_from_object(ThreadsList * t_list, oop obj) {
1268 assert(LockingMode == LM_LIGHTWEIGHT, "Only with new lightweight locking");
1269 for (JavaThread* q : *t_list) {
1270 // Need to start processing before accessing oops in the thread.
1271 StackWatermark* watermark = StackWatermarkSet::get(q, StackWatermarkKind::gc);
1272 if (watermark != nullptr) {
1273 watermark->start_processing();
1274 }
1275
1276 if (q->lock_stack().contains(obj)) {
1277 return q;
1278 }
1279 }
1280 return nullptr;
1281 }
1282
1283 JavaThread* Threads::owning_thread_from_monitor(ThreadsList* t_list, ObjectMonitor* monitor) {
1284 if (LockingMode == LM_LIGHTWEIGHT) {
1285 if (monitor->is_owner_anonymous()) {
1286 return owning_thread_from_object(t_list, monitor->object());
1287 } else {
1288 Thread* owner = reinterpret_cast<Thread*>(monitor->owner());
1289 assert(owner == nullptr || owner->is_Java_thread(), "only JavaThreads own monitors");
1290 return reinterpret_cast<JavaThread*>(owner);
1291 }
1292 } else {
1293 address owner = (address)monitor->owner();
1294 return owning_thread_from_monitor_owner(t_list, owner);
1295 }
1296 }
1297
1298 class PrintOnClosure : public ThreadClosure {
1299 private:
1300 outputStream* _st;
1301
1302 public:
1303 PrintOnClosure(outputStream* st) :
1304 _st(st) {}
1305
1306 virtual void do_thread(Thread* thread) {
1307 if (thread != nullptr) {
1308 thread->print_on(_st);
1309 _st->cr();
1310 }
1311 }
1312 };
1313
1314 // Threads::print_on() is called at safepoint by VM_PrintThreads operation.
1315 void Threads::print_on(outputStream* st, bool print_stacks,
1316 bool internal_format, bool print_concurrent_locks,
1317 bool print_extended_info) {
1318 char buf[32];
1319 st->print_raw_cr(os::local_time_string(buf, sizeof(buf)));
1320
1321 st->print_cr("Full thread dump %s (%s %s):",
1322 VM_Version::vm_name(),
1323 VM_Version::vm_release(),
1324 VM_Version::vm_info_string());
1325 st->cr();
1326
1327 #if INCLUDE_SERVICES
1328 // Dump concurrent locks
1329 ConcurrentLocksDump concurrent_locks;
1330 if (print_concurrent_locks) {
1331 concurrent_locks.dump_at_safepoint();
1332 }
1333 #endif // INCLUDE_SERVICES
1334
1335 ThreadsSMRSupport::print_info_on(st);
1336 st->cr();
1337
1338 ALL_JAVA_THREADS(p) {
1339 ResourceMark rm;
1340 p->print_on(st, print_extended_info);
1341 if (print_stacks) {
1342 if (internal_format) {
1343 p->trace_stack();
1344 } else {
1345 p->print_stack_on(st);
1346 const oop thread_oop = p->threadObj();
1347 if (thread_oop != nullptr) {
1348 if (p->is_vthread_mounted()) {
1349 const oop vt = p->vthread();
1350 assert(vt != nullptr, "vthread should not be null when vthread is mounted");
1351 // JavaThread._vthread can refer to the carrier thread. Print only if _vthread refers to a virtual thread.
1352 if (vt != thread_oop) {
1353 st->print_cr(" Mounted virtual thread #" INT64_FORMAT, (int64_t)java_lang_Thread::thread_id(vt));
1354 p->print_vthread_stack_on(st);
1355 }
1356 }
1357 }
1358 }
1359 }
1360 st->cr();
1361 #if INCLUDE_SERVICES
1362 if (print_concurrent_locks) {
1363 concurrent_locks.print_locks_on(p, st);
1364 }
1365 #endif // INCLUDE_SERVICES
1366 }
1367
1368 PrintOnClosure cl(st);
1369 non_java_threads_do(&cl);
1370
1371 st->flush();
1372 }
1373
1374 void Threads::print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
1375 int buflen, bool* found_current) {
1376 if (this_thread != nullptr) {
1377 bool is_current = (current == this_thread);
1378 *found_current = *found_current || is_current;
1379 st->print("%s", is_current ? "=>" : " ");
1380
1381 st->print(PTR_FORMAT, p2i(this_thread));
1382 st->print(" ");
1383 this_thread->print_on_error(st, buf, buflen);
1384 st->cr();
1385 }
1386 }
1387
1388 class PrintOnErrorClosure : public ThreadClosure {
1389 outputStream* _st;
1390 Thread* _current;
1391 char* _buf;
1392 int _buflen;
1393 bool* _found_current;
1394 unsigned _num_printed;
1395 public:
1396 PrintOnErrorClosure(outputStream* st, Thread* current, char* buf,
1397 int buflen, bool* found_current) :
1398 _st(st), _current(current), _buf(buf), _buflen(buflen), _found_current(found_current),
1399 _num_printed(0) {}
1400
1401 virtual void do_thread(Thread* thread) {
1402 _num_printed++;
1403 Threads::print_on_error(thread, _st, _current, _buf, _buflen, _found_current);
1404 }
1405
1406 unsigned num_printed() const { return _num_printed; }
1407 };
1408
1409 // Threads::print_on_error() is called by fatal error handler. It's possible
1410 // that VM is not at safepoint and/or current thread is inside signal handler.
1411 // Don't print stack trace, as the stack may not be walkable. Don't allocate
1412 // memory (even in resource area), it might deadlock the error handler.
1413 void Threads::print_on_error(outputStream* st, Thread* current, char* buf,
1414 int buflen) {
1415 ThreadsSMRSupport::print_info_on(st);
1416 st->cr();
1417
1418 bool found_current = false;
1419 st->print_cr("Java Threads: ( => current thread )");
1420 unsigned num_java = 0;
1421 ALL_JAVA_THREADS(thread) {
1422 print_on_error(thread, st, current, buf, buflen, &found_current);
1423 num_java++;
1424 }
1425 st->print_cr("Total: %u", num_java);
1426 st->cr();
1427
1428 st->print_cr("Other Threads:");
1429 unsigned num_other = ((VMThread::vm_thread() != nullptr) ? 1 : 0) +
1430 ((WatcherThread::watcher_thread() != nullptr) ? 1 : 0) +
1431 ((AsyncLogWriter::instance() != nullptr) ? 1 : 0);
1432 print_on_error(VMThread::vm_thread(), st, current, buf, buflen, &found_current);
1433 print_on_error(WatcherThread::watcher_thread(), st, current, buf, buflen, &found_current);
1434 print_on_error(AsyncLogWriter::instance(), st, current, buf, buflen, &found_current);
1435
1436 if (Universe::heap() != nullptr) {
1437 PrintOnErrorClosure print_closure(st, current, buf, buflen, &found_current);
1438 Universe::heap()->gc_threads_do(&print_closure);
1439 num_other += print_closure.num_printed();
1440 }
1441
1442 if (!found_current) {
1443 st->cr();
1444 st->print("=>" PTR_FORMAT " (exited) ", p2i(current));
1445 current->print_on_error(st, buf, buflen);
1446 num_other++;
1447 st->cr();
1448 }
1449 st->print_cr("Total: %u", num_other);
1450 st->cr();
1451
1452 st->print_cr("Threads with active compile tasks:");
1453 unsigned num = print_threads_compiling(st, buf, buflen);
1454 st->print_cr("Total: %u", num);
1455 }
1456
1457 unsigned Threads::print_threads_compiling(outputStream* st, char* buf, int buflen, bool short_form) {
1458 unsigned num = 0;
1459 ALL_JAVA_THREADS(thread) {
1460 if (thread->is_Compiler_thread()) {
1461 CompilerThread* ct = (CompilerThread*) thread;
1462
1463 // Keep task in local variable for null check.
1464 // ct->_task might be set to null by concurring compiler thread
1465 // because it completed the compilation. The task is never freed,
1466 // though, just returned to a free list.
1467 CompileTask* task = ct->task();
1468 if (task != nullptr) {
1469 thread->print_name_on_error(st, buf, buflen);
1470 st->print(" ");
1471 task->print(st, nullptr, short_form, true);
1472 num++;
1473 }
1474 }
1475 }
1476 return num;
1477 }
1478
1479 void Threads::verify() {
1480 ALL_JAVA_THREADS(p) {
1481 p->verify();
1482 }
1483 VMThread* thread = VMThread::vm_thread();
1484 if (thread != nullptr) thread->verify();
1485 }