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