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