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_RTM_OPT
113 #include "runtime/rtmLocking.hpp"
114 #endif
115 #if INCLUDE_JFR
116 #include "jfr/jfr.hpp"
117 #endif
118
119 // Initialization after module runtime initialization
120 void universe_post_module_init(); // must happen after call_initPhase2
121
122
123 static void initialize_class(Symbol* class_name, TRAPS) {
124 Klass* klass = SystemDictionary::resolve_or_fail(class_name, true, CHECK);
125 InstanceKlass::cast(klass)->initialize(CHECK);
126 }
127
128
129 // Creates the initial ThreadGroup
130 static Handle create_initial_thread_group(TRAPS) {
131 Handle system_instance = JavaCalls::construct_new_instance(
132 vmClasses::ThreadGroup_klass(),
133 vmSymbols::void_method_signature(),
134 CHECK_NH);
135 Universe::set_system_thread_group(system_instance());
136
137 Handle string = java_lang_String::create_from_str("main", CHECK_NH);
138 Handle main_instance = JavaCalls::construct_new_instance(
139 vmClasses::ThreadGroup_klass(),
140 vmSymbols::threadgroup_string_void_signature(),
141 system_instance,
142 string,
143 CHECK_NH);
144 return main_instance;
145 }
146
147 // Creates the initial Thread, and sets it to running.
148 static void create_initial_thread(Handle thread_group, JavaThread* thread,
149 TRAPS) {
150 InstanceKlass* ik = vmClasses::Thread_klass();
151 assert(ik->is_initialized(), "must be");
152 instanceHandle thread_oop = ik->allocate_instance_handle(CHECK);
153
154 // Cannot use JavaCalls::construct_new_instance because the java.lang.Thread
155 // constructor calls Thread.current(), which must be set here for the
156 // initial thread.
157 java_lang_Thread::set_thread(thread_oop(), thread);
158 thread->set_threadOopHandles(thread_oop());
159
160 Handle string = java_lang_String::create_from_str("main", CHECK);
161
162 JavaValue result(T_VOID);
163 JavaCalls::call_special(&result, thread_oop,
164 ik,
165 vmSymbols::object_initializer_name(),
166 vmSymbols::threadgroup_string_void_signature(),
167 thread_group,
168 string,
169 CHECK);
170
171 assert(thread->lock_id() == ThreadIdentifier::initial(), "invariant");
172
173 // Set thread status to running since main thread has
174 // been started and running.
175 java_lang_Thread::set_thread_status(thread_oop(),
176 JavaThreadStatus::RUNNABLE);
177 }
178
179 // Extract version and vendor specific information from
180 // java.lang.VersionProps fields.
181 // Returned char* is allocated in the thread's resource area
182 // so must be copied for permanency.
183 static const char* get_java_version_info(InstanceKlass* ik,
184 Symbol* field_name) {
185 fieldDescriptor fd;
186 bool found = ik != nullptr &&
187 ik->find_local_field(field_name,
188 vmSymbols::string_signature(), &fd);
189 if (found) {
190 oop name_oop = ik->java_mirror()->obj_field(fd.offset());
191 if (name_oop == nullptr) {
192 return nullptr;
193 }
194 const char* name = java_lang_String::as_utf8_string(name_oop);
195 return name;
196 } else {
197 return nullptr;
198 }
199 }
200
201 // ======= Threads ========
202
203 // The Threads class links together all active threads, and provides
204 // operations over all threads. It is protected by the Threads_lock,
205 // which is also used in other global contexts like safepointing.
206 // ThreadsListHandles are used to safely perform operations on one
207 // or more threads without the risk of the thread exiting during the
208 // operation.
209 //
210 // Note: The Threads_lock is currently more widely used than we
211 // would like. We are actively migrating Threads_lock uses to other
212 // mechanisms in order to reduce Threads_lock contention.
213
214 int Threads::_number_of_threads = 0;
215 int Threads::_number_of_non_daemon_threads = 0;
216 int Threads::_return_code = 0;
217 uintx Threads::_thread_claim_token = 1; // Never zero.
218
219 #ifdef ASSERT
220 bool Threads::_vm_complete = false;
221 #endif
222
223 // General purpose hook into Java code, run once when the VM is initialized.
224 // The Java library method itself may be changed independently from the VM.
225 static void call_postVMInitHook(TRAPS) {
226 Klass* klass = SystemDictionary::resolve_or_null(vmSymbols::jdk_internal_vm_PostVMInitHook(), THREAD);
227 if (klass != nullptr) {
228 JavaValue result(T_VOID);
229 JavaCalls::call_static(&result, klass, vmSymbols::run_method_name(),
230 vmSymbols::void_method_signature(),
231 CHECK);
232 }
233 }
234
235 // All NonJavaThreads (i.e., every non-JavaThread in the system).
236 void Threads::non_java_threads_do(ThreadClosure* tc) {
237 NoSafepointVerifier nsv;
238 for (NonJavaThread::Iterator njti; !njti.end(); njti.step()) {
239 tc->do_thread(njti.current());
240 }
241 }
242
243 // All JavaThreads
244 #define ALL_JAVA_THREADS(X) \
245 for (JavaThread* X : *ThreadsSMRSupport::get_java_thread_list())
246
247 // All JavaThreads
248 void Threads::java_threads_do(ThreadClosure* tc) {
249 assert_locked_or_safepoint(Threads_lock);
250 // ALL_JAVA_THREADS iterates through all JavaThreads.
251 ALL_JAVA_THREADS(p) {
252 tc->do_thread(p);
253 }
254 }
255
256 // All JavaThreads + all non-JavaThreads (i.e., every thread in the system).
257 void Threads::threads_do(ThreadClosure* tc) {
258 assert_locked_or_safepoint(Threads_lock);
259 java_threads_do(tc);
260 non_java_threads_do(tc);
261 }
262
263 void Threads::possibly_parallel_threads_do(bool is_par, ThreadClosure* tc) {
264 assert_at_safepoint();
265
266 uintx claim_token = Threads::thread_claim_token();
267 ALL_JAVA_THREADS(p) {
268 if (p->claim_threads_do(is_par, claim_token)) {
269 tc->do_thread(p);
270 }
271 }
272 for (NonJavaThread::Iterator njti; !njti.end(); njti.step()) {
273 Thread* current = njti.current();
274 if (current->claim_threads_do(is_par, claim_token)) {
275 tc->do_thread(current);
276 }
277 }
278 }
279
280 // The system initialization in the library has three phases.
281 //
282 // Phase 1: java.lang.System class initialization
283 // java.lang.System is a primordial class loaded and initialized
284 // by the VM early during startup. java.lang.System.<clinit>
285 // only does registerNatives and keeps the rest of the class
286 // initialization work later until thread initialization completes.
287 //
288 // System.initPhase1 initializes the system properties, the static
289 // fields in, out, and err. Set up java signal handlers, OS-specific
290 // system settings, and thread group of the main thread.
291 static void call_initPhase1(TRAPS) {
292 Klass* klass = vmClasses::System_klass();
293 JavaValue result(T_VOID);
294 JavaCalls::call_static(&result, klass, vmSymbols::initPhase1_name(),
295 vmSymbols::void_method_signature(), CHECK);
296 }
297
298 // Phase 2. Module system initialization
299 // This will initialize the module system. Only java.base classes
300 // can be loaded until phase 2 completes.
301 //
302 // Call System.initPhase2 after the compiler initialization and jsr292
303 // classes get initialized because module initialization runs a lot of java
304 // code, that for performance reasons, should be compiled. Also, this will
305 // enable the startup code to use lambda and other language features in this
306 // phase and onward.
307 //
308 // After phase 2, The VM will begin search classes from -Xbootclasspath/a.
309 static void call_initPhase2(TRAPS) {
310 TraceTime timer("Initialize module system", TRACETIME_LOG(Info, startuptime));
311
312 Klass* klass = vmClasses::System_klass();
313
314 JavaValue result(T_INT);
315 JavaCallArguments args;
316 args.push_int(DisplayVMOutputToStderr);
317 args.push_int(log_is_enabled(Debug, init)); // print stack trace if exception thrown
318 JavaCalls::call_static(&result, klass, vmSymbols::initPhase2_name(),
319 vmSymbols::boolean_boolean_int_signature(), &args, CHECK);
320 if (result.get_jint() != JNI_OK) {
321 vm_exit_during_initialization(); // no message or exception
322 }
323
324 universe_post_module_init();
325 }
326
327 // Phase 3. final setup - set security manager, system class loader and TCCL
328 //
329 // This will instantiate and set the security manager, set the system class
330 // loader as well as the thread context class loader. The security manager
331 // and system class loader may be a custom class loaded from -Xbootclasspath/a,
332 // other modules or the application's classpath.
333 static void call_initPhase3(TRAPS) {
334 Klass* klass = vmClasses::System_klass();
335 JavaValue result(T_VOID);
336 JavaCalls::call_static(&result, klass, vmSymbols::initPhase3_name(),
337 vmSymbols::void_method_signature(), CHECK);
338 }
339
340 void Threads::initialize_java_lang_classes(JavaThread* main_thread, TRAPS) {
341 TraceTime timer("Initialize java.lang classes", TRACETIME_LOG(Info, startuptime));
342
343 initialize_class(vmSymbols::java_lang_String(), CHECK);
344
345 // Inject CompactStrings value after the static initializers for String ran.
346 java_lang_String::set_compact_strings(CompactStrings);
347
348 // Initialize java_lang.System (needed before creating the thread)
349 initialize_class(vmSymbols::java_lang_System(), CHECK);
350 // The VM creates & returns objects of this class. Make sure it's initialized.
351 initialize_class(vmSymbols::java_lang_Class(), CHECK);
352 initialize_class(vmSymbols::java_lang_ThreadGroup(), CHECK);
353 Handle thread_group = create_initial_thread_group(CHECK);
354 Universe::set_main_thread_group(thread_group());
355 initialize_class(vmSymbols::java_lang_Thread(), CHECK);
356 create_initial_thread(thread_group, main_thread, CHECK);
357
358 // The VM creates objects of this class.
359 initialize_class(vmSymbols::java_lang_Module(), CHECK);
360
361 #ifdef ASSERT
362 InstanceKlass *k = vmClasses::UnsafeConstants_klass();
363 assert(k->is_not_initialized(), "UnsafeConstants should not already be initialized");
364 #endif
365
366 // initialize the hardware-specific constants needed by Unsafe
367 initialize_class(vmSymbols::jdk_internal_misc_UnsafeConstants(), CHECK);
368 jdk_internal_misc_UnsafeConstants::set_unsafe_constants();
369
370 // The VM preresolves methods to these classes. Make sure that they get initialized
371 initialize_class(vmSymbols::java_lang_reflect_Method(), CHECK);
372 initialize_class(vmSymbols::java_lang_ref_Finalizer(), CHECK);
373
374 // Phase 1 of the system initialization in the library, java.lang.System class initialization
375 call_initPhase1(CHECK);
376
377 // Get the Java runtime name, version, and vendor info after java.lang.System is initialized.
378 // Some values are actually configure-time constants but some can be set via the jlink tool and
379 // so must be read dynamically. We treat them all the same.
380 InstanceKlass* ik = SystemDictionary::find_instance_klass(THREAD, vmSymbols::java_lang_VersionProps(),
381 Handle(), Handle());
382 {
383 ResourceMark rm(main_thread);
384 JDK_Version::set_java_version(get_java_version_info(ik, vmSymbols::java_version_name()));
385
386 JDK_Version::set_runtime_name(get_java_version_info(ik, vmSymbols::java_runtime_name_name()));
387
388 JDK_Version::set_runtime_version(get_java_version_info(ik, vmSymbols::java_runtime_version_name()));
389
390 JDK_Version::set_runtime_vendor_version(get_java_version_info(ik, vmSymbols::java_runtime_vendor_version_name()));
391
392 JDK_Version::set_runtime_vendor_vm_bug_url(get_java_version_info(ik, vmSymbols::java_runtime_vendor_vm_bug_url_name()));
393 }
394
395 // an instance of OutOfMemory exception has been allocated earlier
396 initialize_class(vmSymbols::java_lang_OutOfMemoryError(), CHECK);
397 initialize_class(vmSymbols::java_lang_NullPointerException(), CHECK);
398 initialize_class(vmSymbols::java_lang_ClassCastException(), CHECK);
399 initialize_class(vmSymbols::java_lang_ArrayStoreException(), CHECK);
400 initialize_class(vmSymbols::java_lang_ArithmeticException(), CHECK);
401 initialize_class(vmSymbols::java_lang_StackOverflowError(), CHECK);
402 initialize_class(vmSymbols::java_lang_IllegalMonitorStateException(), CHECK);
403 initialize_class(vmSymbols::java_lang_IllegalArgumentException(), CHECK);
404 }
405
406 void Threads::initialize_jsr292_core_classes(TRAPS) {
407 TraceTime timer("Initialize java.lang.invoke classes", TRACETIME_LOG(Info, startuptime));
408
409 initialize_class(vmSymbols::java_lang_invoke_MethodHandle(), CHECK);
410 initialize_class(vmSymbols::java_lang_invoke_ResolvedMethodName(), CHECK);
411 initialize_class(vmSymbols::java_lang_invoke_MemberName(), CHECK);
412 initialize_class(vmSymbols::java_lang_invoke_MethodHandleNatives(), CHECK);
413 }
414
415 jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) {
416 extern void JDK_Version_init();
417
418 // Preinitialize version info.
419 VM_Version::early_initialize();
420
421 // Check version
422 if (!is_supported_jni_version(args->version)) return JNI_EVERSION;
423
424 // Initialize library-based TLS
425 ThreadLocalStorage::init();
426
427 // Initialize the output stream module
428 ostream_init();
429
430 // Process java launcher properties.
431 Arguments::process_sun_java_launcher_properties(args);
432
433 // Initialize the os module
434 os::init();
435
436 MACOS_AARCH64_ONLY(os::current_thread_enable_wx(WXWrite));
437
438 // Record VM creation timing statistics
439 TraceVmCreationTime create_vm_timer;
440 create_vm_timer.start();
441
442 // Initialize system properties.
443 Arguments::init_system_properties();
444
445 // So that JDK version can be used as a discriminator when parsing arguments
446 JDK_Version_init();
447
448 // Update/Initialize System properties after JDK version number is known
449 Arguments::init_version_specific_system_properties();
450
451 // Make sure to initialize log configuration *before* parsing arguments
452 LogConfiguration::initialize(create_vm_timer.begin_time());
453
454 // Parse arguments
455 // Note: this internally calls os::init_container_support()
456 jint parse_result = Arguments::parse(args);
457 if (parse_result != JNI_OK) return parse_result;
458
459 // Initialize NMT right after argument parsing to keep the pre-NMT-init window small.
460 MemTracker::initialize();
461
462 os::init_before_ergo();
463
464 jint ergo_result = Arguments::apply_ergo();
465 if (ergo_result != JNI_OK) return ergo_result;
466
467 // Final check of all ranges after ergonomics which may change values.
468 if (!JVMFlagLimit::check_all_ranges()) {
469 return JNI_EINVAL;
470 }
471
472 // Final check of all 'AfterErgo' constraints after ergonomics which may change values.
473 bool constraint_result = JVMFlagLimit::check_all_constraints(JVMFlagConstraintPhase::AfterErgo);
474 if (!constraint_result) {
475 return JNI_EINVAL;
476 }
477
478 if (PauseAtStartup) {
479 os::pause();
480 }
481
482 HOTSPOT_VM_INIT_BEGIN();
483
484 // Timing (must come after argument parsing)
485 TraceTime timer("Create VM", TRACETIME_LOG(Info, startuptime));
486
487 // Initialize the os module after parsing the args
488 jint os_init_2_result = os::init_2();
489 if (os_init_2_result != JNI_OK) return os_init_2_result;
490
491 #ifdef CAN_SHOW_REGISTERS_ON_ASSERT
492 // Initialize assert poison page mechanism.
493 if (ShowRegistersOnAssert) {
494 initialize_assert_poison();
495 }
496 #endif // CAN_SHOW_REGISTERS_ON_ASSERT
497
498 SafepointMechanism::initialize();
499
500 jint adjust_after_os_result = Arguments::adjust_after_os();
501 if (adjust_after_os_result != JNI_OK) return adjust_after_os_result;
502
503 // Initialize output stream logging
504 ostream_init_log();
505
506 // Launch -agentlib/-agentpath and converted -Xrun agents
507 JvmtiAgentList::load_agents();
508
509 // Initialize Threads state
510 _number_of_threads = 0;
511 _number_of_non_daemon_threads = 0;
512
513 // Initialize global data structures and create system classes in heap
514 vm_init_globals();
515
516 #if INCLUDE_JVMCI
517 if (JVMCICounterSize > 0) {
518 JavaThread::_jvmci_old_thread_counters = NEW_C_HEAP_ARRAY(jlong, JVMCICounterSize, mtJVMCI);
519 memset(JavaThread::_jvmci_old_thread_counters, 0, sizeof(jlong) * JVMCICounterSize);
520 } else {
521 JavaThread::_jvmci_old_thread_counters = nullptr;
522 }
523 #endif // INCLUDE_JVMCI
524
525 // Initialize OopStorage for threadObj
526 JavaThread::_thread_oop_storage = OopStorageSet::create_strong("Thread OopStorage", mtThread);
527
528 // Attach the main thread to this os thread
529 JavaThread* main_thread = new JavaThread();
530 main_thread->set_thread_state(_thread_in_vm);
531 main_thread->initialize_thread_current();
532 // must do this before set_active_handles
533 main_thread->record_stack_base_and_size();
534 main_thread->register_thread_stack_with_NMT();
535 main_thread->set_active_handles(JNIHandleBlock::allocate_block());
536 MACOS_AARCH64_ONLY(main_thread->init_wx());
537
538 // Set the lock_id now since we will run Java code before the Thread instance
539 // is even created. The same value will be assigned to the Thread instance on init.
540 main_thread->set_lock_id(ThreadIdentifier::next());
541 assert(main_thread->lock_id() == ThreadIdentifier::initial(), "invariant");
542
543 if (!main_thread->set_as_starting_thread()) {
544 vm_shutdown_during_initialization(
545 "Failed necessary internal allocation. Out of swap space");
546 main_thread->smr_delete();
547 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
548 return JNI_ENOMEM;
549 }
550
551 // Enable guard page *after* os::create_main_thread(), otherwise it would
552 // crash Linux VM, see notes in os_linux.cpp.
553 main_thread->stack_overflow_state()->create_stack_guard_pages();
554
555 // Initialize Java-Level synchronization subsystem
556 ObjectMonitor::Initialize();
557 ObjectSynchronizer::initialize();
558
559 // Initialize global modules
560 jint status = init_globals();
561 if (status != JNI_OK) {
562 main_thread->smr_delete();
563 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
564 return status;
565 }
566
567 // Create WatcherThread as soon as we can since we need it in case
568 // of hangs during error reporting.
569 WatcherThread::start();
570
571 // Add main_thread to threads list to finish barrier setup with
572 // on_thread_attach. Should be before starting to build Java objects in
573 // init_globals2, which invokes barriers.
574 {
575 MutexLocker mu(Threads_lock);
576 Threads::add(main_thread);
577 }
578
579 status = init_globals2();
580 if (status != JNI_OK) {
581 Threads::remove(main_thread, false);
582 // It is possible that we managed to fully initialize Universe but have then
583 // failed by throwing an exception. In that case our caller JNI_CreateJavaVM
584 // will want to report it, so we can't delete the main thread.
585 if (!main_thread->has_pending_exception()) {
586 main_thread->smr_delete();
587 }
588 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
589 return status;
590 }
591
592 ObjectMonitor::Initialize2();
593
594 JFR_ONLY(Jfr::on_create_vm_1();)
595
596 // Should be done after the heap is fully created
597 main_thread->cache_global_variables();
598
599 // Any JVMTI raw monitors entered in onload will transition into
600 // real raw monitor. VM is setup enough here for raw monitor enter.
601 JvmtiExport::transition_pending_onload_raw_monitors();
602
603 // Create the VMThread
604 { TraceTime timer("Start VMThread", TRACETIME_LOG(Info, startuptime));
605
606 VMThread::create();
607 VMThread* vmthread = VMThread::vm_thread();
608
609 if (!os::create_thread(vmthread, os::vm_thread)) {
610 vm_exit_during_initialization("Cannot create VM thread. "
611 "Out of system resources.");
612 }
613
614 // Wait for the VM thread to become ready, and VMThread::run to initialize
615 // Monitors can have spurious returns, must always check another state flag
616 {
617 MonitorLocker ml(Notify_lock);
618 os::start_thread(vmthread);
619 while (!vmthread->is_running()) {
620 ml.wait();
621 }
622 }
623 }
624
625 assert(Universe::is_fully_initialized(), "not initialized");
626 if (VerifyDuringStartup) {
627 // Make sure we're starting with a clean slate.
628 VM_Verify verify_op;
629 VMThread::execute(&verify_op);
630 }
631
632 // We need this to update the java.vm.info property in case any flags used
633 // to initially define it have been changed. This is needed for both CDS
634 // since UseSharedSpaces may be changed after java.vm.info
635 // is initially computed. See Abstract_VM_Version::vm_info_string().
636 // This update must happen before we initialize the java classes, but
637 // after any initialization logic that might modify the flags.
638 Arguments::update_vm_info_property(VM_Version::vm_info_string());
639
640 JavaThread* THREAD = JavaThread::current(); // For exception macros.
641 HandleMark hm(THREAD);
642
643 // Always call even when there are not JVMTI environments yet, since environments
644 // may be attached late and JVMTI must track phases of VM execution
645 JvmtiExport::enter_early_start_phase();
646
647 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
648 JvmtiExport::post_early_vm_start();
649
650 // Launch -Xrun agents early if EagerXrunInit is set
651 if (EagerXrunInit) {
652 JvmtiAgentList::load_xrun_agents();
653 }
654
655 initialize_java_lang_classes(main_thread, CHECK_JNI_ERR);
656
657 quicken_jni_functions();
658
659 // No more stub generation allowed after that point.
660 StubCodeDesc::freeze();
661
662 // Set flag that basic initialization has completed. Used by exceptions and various
663 // debug stuff, that does not work until all basic classes have been initialized.
664 set_init_completed();
665
666 LogConfiguration::post_initialize();
667 Metaspace::post_initialize();
668 MutexLockerImpl::post_initialize();
669
670 HOTSPOT_VM_INIT_END();
671
672 // record VM initialization completion time
673 #if INCLUDE_MANAGEMENT
674 Management::record_vm_init_completed();
675 #endif // INCLUDE_MANAGEMENT
676
677 log_info(os)("Initialized VM with process ID %d", os::current_process_id());
678
679 // Signal Dispatcher needs to be started before VMInit event is posted
680 os::initialize_jdk_signal_support(CHECK_JNI_ERR);
681
682 // Start Attach Listener if +StartAttachListener or it can't be started lazily
683 if (!DisableAttachMechanism) {
684 AttachListener::vm_start();
685 if (StartAttachListener || AttachListener::init_at_startup()) {
686 AttachListener::init();
687 }
688 }
689
690 // Launch -Xrun agents if EagerXrunInit is not set.
691 if (!EagerXrunInit) {
692 JvmtiAgentList::load_xrun_agents();
693 }
694
695 Arena::start_chunk_pool_cleaner_task();
696
697 // Start the service thread
698 // The service thread enqueues JVMTI deferred events and does various hashtable
699 // and other cleanups. Needs to start before the compilers start posting events.
700 ServiceThread::initialize();
701
702 // Start the monitor deflation thread:
703 MonitorDeflationThread::initialize();
704
705 // initialize compiler(s)
706 #if defined(COMPILER1) || COMPILER2_OR_JVMCI
707 bool init_compilation = true;
708 #if INCLUDE_JVMCI
709 bool force_JVMCI_initialization = false;
710 if (EnableJVMCI) {
711 // Initialize JVMCI eagerly when it is explicitly requested.
712 // Or when JVMCILibDumpJNIConfig or JVMCIPrintProperties is enabled.
713 force_JVMCI_initialization = EagerJVMCI || JVMCIPrintProperties || JVMCILibDumpJNIConfig;
714 if (!force_JVMCI_initialization && UseJVMCICompiler && !UseJVMCINativeLibrary && (!UseInterpreter || !BackgroundCompilation)) {
715 // Force initialization of jarjvmci otherwise requests for blocking
716 // compilations will not actually block until jarjvmci is initialized.
717 force_JVMCI_initialization = true;
718 }
719 if (JVMCIPrintProperties || JVMCILibDumpJNIConfig) {
720 // Both JVMCILibDumpJNIConfig and JVMCIPrintProperties exit the VM
721 // so compilation should be disabled. This prevents dumping or
722 // printing from happening more than once.
723 init_compilation = false;
724 }
725 }
726 #endif
727 if (init_compilation) {
728 CompileBroker::compilation_init(CHECK_JNI_ERR);
729 }
730 #endif
731
732 // Start string deduplication thread if requested.
733 if (StringDedup::is_enabled()) {
734 StringDedup::start();
735 }
736
737 // Pre-initialize some JSR292 core classes to avoid deadlock during class loading.
738 // It is done after compilers are initialized, because otherwise compilations of
739 // signature polymorphic MH intrinsics can be missed
740 // (see SystemDictionary::find_method_handle_intrinsic).
741 initialize_jsr292_core_classes(CHECK_JNI_ERR);
742
743 // This will initialize the module system. Only java.base classes can be
744 // loaded until phase 2 completes
745 call_initPhase2(CHECK_JNI_ERR);
746
747 JFR_ONLY(Jfr::on_create_vm_2();)
748
749 // Always call even when there are not JVMTI environments yet, since environments
750 // may be attached late and JVMTI must track phases of VM execution
751 JvmtiExport::enter_start_phase();
752
753 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
754 JvmtiExport::post_vm_start();
755
756 // Final system initialization including security manager and system class loader
757 call_initPhase3(CHECK_JNI_ERR);
758
759 // cache the system and platform class loaders
760 SystemDictionary::compute_java_loaders(CHECK_JNI_ERR);
761
762 if (Continuations::enabled()) {
763 // Initialize Continuation class now so that failure to create enterSpecial/doYield
764 // special nmethods due to limited CodeCache size can be treated as a fatal error at
765 // startup with the proper message that CodeCache size is too small.
766 initialize_class(vmSymbols::jdk_internal_vm_Continuation(), CHECK_JNI_ERR);
767 }
768
769 #if INCLUDE_CDS
770 // capture the module path info from the ModuleEntryTable
771 ClassLoader::initialize_module_path(THREAD);
772 if (HAS_PENDING_EXCEPTION) {
773 java_lang_Throwable::print(PENDING_EXCEPTION, tty);
774 vm_exit_during_initialization("ClassLoader::initialize_module_path() failed unexpectedly");
775 }
776 #endif
777
778 #if INCLUDE_JVMCI
779 if (force_JVMCI_initialization) {
780 JVMCI::initialize_compiler(CHECK_JNI_ERR);
781 }
782 #endif
783
784 if (NativeHeapTrimmer::enabled()) {
785 NativeHeapTrimmer::initialize();
786 }
787
788 // Always call even when there are not JVMTI environments yet, since environments
789 // may be attached late and JVMTI must track phases of VM execution
790 JvmtiExport::enter_live_phase();
791
792 // Make perfmemory accessible
793 PerfMemory::set_accessible(true);
794
795 // Notify JVMTI agents that VM initialization is complete - nop if no agents.
796 JvmtiExport::post_vm_initialized();
797
798 JFR_ONLY(Jfr::on_create_vm_3();)
799
800 #if INCLUDE_MANAGEMENT
801 Management::initialize(THREAD);
802
803 if (HAS_PENDING_EXCEPTION) {
804 // management agent fails to start possibly due to
805 // configuration problem and is responsible for printing
806 // stack trace if appropriate. Simply exit VM.
807 vm_exit(1);
808 }
809 #endif // INCLUDE_MANAGEMENT
810
811 StatSampler::engage();
812 if (CheckJNICalls) JniPeriodicChecker::engage();
813
814 #if INCLUDE_RTM_OPT
815 RTMLockingCounters::init();
816 #endif
817
818 call_postVMInitHook(THREAD);
819 // The Java side of PostVMInitHook.run must deal with all
820 // exceptions and provide means of diagnosis.
821 if (HAS_PENDING_EXCEPTION) {
822 CLEAR_PENDING_EXCEPTION;
823 }
824
825 // Let WatcherThread run all registered periodic tasks now.
826 // NOTE: All PeriodicTasks should be registered by now. If they
827 // aren't, late joiners might appear to start slowly (we might
828 // take a while to process their first tick).
829 WatcherThread::run_all_tasks();
830
831 create_vm_timer.end();
832 #ifdef ASSERT
833 _vm_complete = true;
834 #endif
835
836 if (CDSConfig::is_dumping_static_archive()) {
837 MetaspaceShared::preload_and_dump();
838 }
839
840 return JNI_OK;
841 }
842
843 // Threads::destroy_vm() is normally called from jni_DestroyJavaVM() when
844 // the program falls off the end of main(). Another VM exit path is through
845 // vm_exit(), when the program calls System.exit() to return a value, or when
846 // there is a serious error in VM.
847 // These two separate shutdown paths are not exactly the same, but they share
848 // Shutdown.shutdown() at Java level and before_exit() and VM_Exit op at VM level.
849 //
850 // Shutdown sequence:
851 // + Shutdown native memory tracking if it is on
852 // + Wait until we are the last non-daemon thread to execute
853 // <-- every thing is still working at this moment -->
854 // + Call java.lang.Shutdown.shutdown(), which will invoke Java level
855 // shutdown hooks
856 // + Call before_exit(), prepare for VM exit
857 // > run VM level shutdown hooks (they are registered through JVM_OnExit(),
858 // currently the only user of this mechanism is File.deleteOnExit())
859 // > stop StatSampler, watcher thread,
860 // post thread end and vm death events to JVMTI,
861 // stop signal thread
862 // + Call JavaThread::exit(), it will:
863 // > release JNI handle blocks, remove stack guard pages
864 // > remove this thread from Threads list
865 // <-- no more Java code from this thread after this point -->
866 // + Stop VM thread, it will bring the remaining VM to a safepoint and stop
867 // the compiler threads at safepoint
868 // <-- do not use anything that could get blocked by Safepoint -->
869 // + Disable tracing at JNI/JVM barriers
870 // + Set _vm_exited flag for threads that are still running native code
871 // + Call exit_globals()
872 // > deletes tty
873 // > deletes PerfMemory resources
874 // + Delete this thread
875 // + Return to caller
876
877 void Threads::destroy_vm() {
878 JavaThread* thread = JavaThread::current();
879
880 #ifdef ASSERT
881 _vm_complete = false;
882 #endif
883 // Wait until we are the last non-daemon thread to execute, or
884 // if we are a daemon then wait until the last non-daemon thread has
885 // executed.
886 bool daemon = java_lang_Thread::is_daemon(thread->threadObj());
887 int expected = daemon ? 0 : 1;
888 {
889 MonitorLocker nu(Threads_lock);
890 while (Threads::number_of_non_daemon_threads() > expected)
891 // This wait should make safepoint checks, wait without a timeout.
892 nu.wait(0);
893 }
894
895 EventShutdown e;
896 if (e.should_commit()) {
897 e.set_reason("No remaining non-daemon Java threads");
898 e.commit();
899 }
900
901 // Hang forever on exit if we are reporting an error.
902 if (ShowMessageBoxOnError && VMError::is_error_reported()) {
903 os::infinite_sleep();
904 }
905 os::wait_for_keypress_at_exit();
906
907 // run Java level shutdown hooks
908 thread->invoke_shutdown_hooks();
909
910 before_exit(thread);
911
912 thread->exit(true);
913
914 // We are no longer on the main thread list but could still be in a
915 // secondary list where another thread may try to interact with us.
916 // So wait until all such interactions are complete before we bring
917 // the VM to the termination safepoint. Normally this would be done
918 // using thread->smr_delete() below where we delete the thread, but
919 // we can't call that after the termination safepoint is active as
920 // we will deadlock on the Threads_lock. Once all interactions are
921 // complete it is safe to directly delete the thread at any time.
922 ThreadsSMRSupport::wait_until_not_protected(thread);
923
924 // Stop VM thread.
925 {
926 // 4945125 The vm thread comes to a safepoint during exit.
927 // GC vm_operations can get caught at the safepoint, and the
928 // heap is unparseable if they are caught. Grab the Heap_lock
929 // to prevent this. The GC vm_operations will not be able to
930 // queue until after the vm thread is dead. After this point,
931 // we'll never emerge out of the safepoint before the VM exits.
932 // Assert that the thread is terminated so that acquiring the
933 // Heap_lock doesn't cause the terminated thread to participate in
934 // the safepoint protocol.
935
936 assert(thread->is_terminated(), "must be terminated here");
937 MutexLocker ml(Heap_lock);
938
939 VMThread::wait_for_vm_thread_exit();
940 assert(SafepointSynchronize::is_at_safepoint(), "VM thread should exit at Safepoint");
941 VMThread::destroy();
942 }
943
944 // Now, all Java threads are gone except daemon threads. Daemon threads
945 // running Java code or in VM are stopped by the Safepoint. However,
946 // daemon threads executing native code are still running. But they
947 // will be stopped at native=>Java/VM barriers. Note that we can't
948 // simply kill or suspend them, as it is inherently deadlock-prone.
949
950 VM_Exit::set_vm_exited();
951
952 // Clean up ideal graph printers after the VMThread has started
953 // the final safepoint which will block all the Compiler threads.
954 // Note that this Thread has already logically exited so the
955 // clean_up() function's use of a JavaThreadIteratorWithHandle
956 // would be a problem except set_vm_exited() has remembered the
957 // shutdown thread which is granted a policy exception.
958 #if defined(COMPILER2) && !defined(PRODUCT)
959 IdealGraphPrinter::clean_up();
960 #endif
961
962 notify_vm_shutdown();
963
964 // exit_globals() will delete tty
965 exit_globals();
966
967 // Deleting the shutdown thread here is safe. See comment on
968 // wait_until_not_protected() above.
969 delete thread;
970
971 #if INCLUDE_JVMCI
972 if (JVMCICounterSize > 0) {
973 FREE_C_HEAP_ARRAY(jlong, JavaThread::_jvmci_old_thread_counters);
974 }
975 #endif
976
977 LogConfiguration::finalize();
978 }
979
980
981 jboolean Threads::is_supported_jni_version_including_1_1(jint version) {
982 if (version == JNI_VERSION_1_1) return JNI_TRUE;
983 return is_supported_jni_version(version);
984 }
985
986
987 jboolean Threads::is_supported_jni_version(jint version) {
988 if (version == JNI_VERSION_1_2) return JNI_TRUE;
989 if (version == JNI_VERSION_1_4) return JNI_TRUE;
990 if (version == JNI_VERSION_1_6) return JNI_TRUE;
991 if (version == JNI_VERSION_1_8) return JNI_TRUE;
992 if (version == JNI_VERSION_9) return JNI_TRUE;
993 if (version == JNI_VERSION_10) return JNI_TRUE;
994 if (version == JNI_VERSION_19) return JNI_TRUE;
995 if (version == JNI_VERSION_20) return JNI_TRUE;
996 if (version == JNI_VERSION_21) return JNI_TRUE;
997 return JNI_FALSE;
998 }
999
1000 void Threads::add(JavaThread* p, bool force_daemon) {
1001 // The threads lock must be owned at this point
1002 assert(Threads_lock->owned_by_self(), "must have threads lock");
1003
1004 BarrierSet::barrier_set()->on_thread_attach(p);
1005
1006 // Once a JavaThread is added to the Threads list, smr_delete() has
1007 // to be used to delete it. Otherwise we can just delete it directly.
1008 p->set_on_thread_list();
1009
1010 _number_of_threads++;
1011 oop threadObj = p->threadObj();
1012 bool daemon = true;
1013 // Bootstrapping problem: threadObj can be null for initial
1014 // JavaThread (or for threads attached via JNI)
1015 if (!force_daemon &&
1016 (threadObj == nullptr || !java_lang_Thread::is_daemon(threadObj))) {
1017 _number_of_non_daemon_threads++;
1018 daemon = false;
1019 }
1020
1021 ThreadService::add_thread(p, daemon);
1022
1023 // Maintain fast thread list
1024 ThreadsSMRSupport::add_thread(p);
1025
1026 // Increase the ObjectMonitor ceiling for the new thread.
1027 ObjectSynchronizer::inc_in_use_list_ceiling();
1028
1029 // Possible GC point.
1030 Events::log(Thread::current(), "Thread added: " INTPTR_FORMAT, p2i(p));
1031
1032 // Make new thread known to active EscapeBarrier
1033 EscapeBarrier::thread_added(p);
1034 }
1035
1036 void Threads::remove(JavaThread* p, bool is_daemon) {
1037 // Extra scope needed for Thread_lock, so we can check
1038 // that we do not remove thread without safepoint code notice
1039 { MonitorLocker ml(Threads_lock);
1040
1041 if (ThreadIdTable::is_initialized()) {
1042 // This cleanup must be done before the current thread's GC barrier
1043 // is detached since we need to touch the threadObj oop.
1044 jlong tid = SharedRuntime::get_java_tid(p);
1045 ThreadIdTable::remove_thread(tid);
1046 }
1047
1048 // BarrierSet state must be destroyed after the last thread transition
1049 // before the thread terminates. Thread transitions result in calls to
1050 // StackWatermarkSet::on_safepoint(), which performs GC processing,
1051 // requiring the GC state to be alive.
1052 BarrierSet::barrier_set()->on_thread_detach(p);
1053 if (p->is_exiting()) {
1054 // If we got here via JavaThread::exit(), then we remember that the
1055 // thread's GC barrier has been detached. We don't do this when we get
1056 // here from another path, e.g., cleanup_failed_attach_current_thread().
1057 p->set_terminated(JavaThread::_thread_gc_barrier_detached);
1058 }
1059
1060 assert(ThreadsSMRSupport::get_java_thread_list()->includes(p), "p must be present");
1061
1062 // Maintain fast thread list
1063 ThreadsSMRSupport::remove_thread(p);
1064
1065 _number_of_threads--;
1066 if (!is_daemon) {
1067 _number_of_non_daemon_threads--;
1068
1069 // If this is the last non-daemon thread then we need to do
1070 // a notify on the Threads_lock so a thread waiting
1071 // on destroy_vm will wake up. But that thread could be a daemon
1072 // or non-daemon, so we notify for both the 0 and 1 case.
1073 if (number_of_non_daemon_threads() <= 1) {
1074 ml.notify_all();
1075 }
1076 }
1077 ThreadService::remove_thread(p, is_daemon);
1078
1079 // Make sure that safepoint code disregard this thread. This is needed since
1080 // the thread might mess around with locks after this point. This can cause it
1081 // to do callbacks into the safepoint code. However, the safepoint code is not aware
1082 // of this thread since it is removed from the queue.
1083 p->set_terminated(JavaThread::_thread_terminated);
1084
1085 // Notify threads waiting in EscapeBarriers
1086 EscapeBarrier::thread_removed(p);
1087 } // unlock Threads_lock
1088
1089 // Reduce the ObjectMonitor ceiling for the exiting thread.
1090 ObjectSynchronizer::dec_in_use_list_ceiling();
1091
1092 // Since Events::log uses a lock, we grab it outside the Threads_lock
1093 Events::log(Thread::current(), "Thread exited: " INTPTR_FORMAT, p2i(p));
1094 }
1095
1096 // Operations on the Threads list for GC. These are not explicitly locked,
1097 // but the garbage collector must provide a safe context for them to run.
1098 // In particular, these things should never be called when the Threads_lock
1099 // is held by some other thread. (Note: the Safepoint abstraction also
1100 // uses the Threads_lock to guarantee this property. It also makes sure that
1101 // all threads gets blocked when exiting or starting).
1102
1103 void Threads::oops_do(OopClosure* f, NMethodClosure* cf) {
1104 ALL_JAVA_THREADS(p) {
1105 p->oops_do(f, cf);
1106 }
1107 VMThread::vm_thread()->oops_do(f, cf);
1108 }
1109
1110 void Threads::change_thread_claim_token() {
1111 if (++_thread_claim_token == 0) {
1112 // On overflow of the token counter, there is a risk of future
1113 // collisions between a new global token value and a stale token
1114 // for a thread, because not all iterations visit all threads.
1115 // (Though it's pretty much a theoretical concern for non-trivial
1116 // token counter sizes.) To deal with the possibility, reset all
1117 // the thread tokens to zero on global token overflow.
1118 struct ResetClaims : public ThreadClosure {
1119 virtual void do_thread(Thread* t) {
1120 t->claim_threads_do(false, 0);
1121 }
1122 } reset_claims;
1123 Threads::threads_do(&reset_claims);
1124 // On overflow, update the global token to non-zero, to
1125 // avoid the special "never claimed" initial thread value.
1126 _thread_claim_token = 1;
1127 }
1128 }
1129
1130 #ifdef ASSERT
1131 static void assert_thread_claimed(const char* kind, Thread* t, uintx expected) {
1132 const uintx token = t->threads_do_token();
1133 assert(token == expected,
1134 "%s " PTR_FORMAT " has incorrect value " UINTX_FORMAT " != "
1135 UINTX_FORMAT, kind, p2i(t), token, expected);
1136 }
1137
1138 void Threads::assert_all_threads_claimed() {
1139 ALL_JAVA_THREADS(p) {
1140 assert_thread_claimed("JavaThread", p, _thread_claim_token);
1141 }
1142
1143 struct NJTClaimedVerifierClosure : public ThreadClosure {
1144 uintx _thread_claim_token;
1145
1146 NJTClaimedVerifierClosure(uintx thread_claim_token) : ThreadClosure(), _thread_claim_token(thread_claim_token) { }
1147
1148 virtual void do_thread(Thread* thread) override {
1149 assert_thread_claimed("Non-JavaThread", VMThread::vm_thread(), _thread_claim_token);
1150 }
1151 } tc(_thread_claim_token);
1152
1153 non_java_threads_do(&tc);
1154 }
1155 #endif // ASSERT
1156
1157 class ParallelOopsDoThreadClosure : public ThreadClosure {
1158 private:
1159 OopClosure* _f;
1160 NMethodClosure* _cf;
1161 public:
1162 ParallelOopsDoThreadClosure(OopClosure* f, NMethodClosure* cf) : _f(f), _cf(cf) {}
1163 void do_thread(Thread* t) {
1164 t->oops_do(_f, _cf);
1165 }
1166 };
1167
1168 void Threads::possibly_parallel_oops_do(bool is_par, OopClosure* f, NMethodClosure* cf) {
1169 ParallelOopsDoThreadClosure tc(f, cf);
1170 possibly_parallel_threads_do(is_par, &tc);
1171 }
1172
1173 void Threads::metadata_do(MetadataClosure* f) {
1174 ALL_JAVA_THREADS(p) {
1175 p->metadata_do(f);
1176 }
1177 }
1178
1179 class ThreadHandlesClosure : public ThreadClosure {
1180 void (*_f)(Metadata*);
1181 public:
1182 ThreadHandlesClosure(void f(Metadata*)) : _f(f) {}
1183 virtual void do_thread(Thread* thread) {
1184 thread->metadata_handles_do(_f);
1185 }
1186 };
1187
1188 void Threads::metadata_handles_do(void f(Metadata*)) {
1189 // Only walk the Handles in Thread.
1190 ThreadHandlesClosure handles_closure(f);
1191 threads_do(&handles_closure);
1192 }
1193
1194 #if INCLUDE_JVMTI
1195 // Get count of Java threads that are waiting to enter or re-enter the specified monitor.
1196 GrowableArray<JavaThread*>* Threads::get_pending_threads(ThreadsList * t_list,
1197 int count,
1198 address monitor) {
1199 assert(Thread::current()->is_VM_thread(), "Must be the VM thread");
1200 GrowableArray<JavaThread*>* result = new GrowableArray<JavaThread*>(count);
1201
1202 int i = 0;
1203 for (JavaThread* p : *t_list) {
1204 if (!p->can_call_java()) continue;
1205
1206 // The first stage of async deflation does not affect any field
1207 // used by this comparison so the ObjectMonitor* is usable here.
1208 address pending = (address)p->current_pending_monitor();
1209 address waiting = (address)p->current_waiting_monitor();
1210 oop thread_oop = JvmtiEnvBase::get_vthread_or_thread_oop(p);
1211 bool is_virtual = java_lang_VirtualThread::is_instance(thread_oop);
1212 jint state = is_virtual ? JvmtiEnvBase::get_vthread_state(thread_oop, p)
1213 : JvmtiEnvBase::get_thread_state(thread_oop, p);
1214 if (pending == monitor || (waiting == monitor &&
1215 (state & JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER))
1216 ) { // found a match
1217 if (i < count) result->append(p); // save the first count matches
1218 i++;
1219 }
1220 }
1221
1222 return result;
1223 }
1224 #endif // INCLUDE_JVMTI
1225
1226 JavaThread *Threads::owning_thread_from_stacklock(ThreadsList * t_list, address basicLock) {
1227 assert(LockingMode == LM_LEGACY, "Not with new lightweight locking");
1228
1229 JavaThread* the_owner = nullptr;
1230 for (JavaThread* q : *t_list) {
1231 if (q->is_lock_owned(basicLock)) {
1232 the_owner = q;
1233 break;
1234 }
1235 }
1236 return the_owner;
1237 }
1238
1239 JavaThread* Threads::owning_thread_from_object(ThreadsList * t_list, oop obj) {
1240 assert(LockingMode == LM_LIGHTWEIGHT, "Only with new lightweight locking");
1241 for (JavaThread* q : *t_list) {
1242 // Need to start processing before accessing oops in the thread.
1243 StackWatermark* watermark = StackWatermarkSet::get(q, StackWatermarkKind::gc);
1244 if (watermark != nullptr) {
1245 watermark->start_processing();
1246 }
1247
1248 if (q->lock_stack().contains(obj)) {
1249 return q;
1250 }
1251 }
1252 return nullptr;
1253 }
1254
1255 JavaThread* Threads::owning_thread_from_monitor(ThreadsList* t_list, ObjectMonitor* monitor) {
1256 if (monitor->is_owner_anonymous()) {
1257 if (LockingMode == LM_LIGHTWEIGHT) {
1258 return owning_thread_from_object(t_list, monitor->object());
1259 } else {
1260 assert(LockingMode == LM_LEGACY, "invariant");
1261 return owning_thread_from_stacklock(t_list, (address)monitor->stack_locker());
1262 }
1263 } else {
1264 JavaThread* the_owner = nullptr;
1265 int64_t owner_tid = (int64_t)monitor->owner();
1266 for (JavaThread* q : *t_list) {
1267 if (monitor->is_owner(q)) {
1268 the_owner = q;
1269 break;
1270 }
1271 }
1272 return the_owner;
1273 }
1274 }
1275
1276 class PrintOnClosure : public ThreadClosure {
1277 private:
1278 outputStream* _st;
1279
1280 public:
1281 PrintOnClosure(outputStream* st) :
1282 _st(st) {}
1283
1284 virtual void do_thread(Thread* thread) {
1285 if (thread != nullptr) {
1286 thread->print_on(_st);
1287 _st->cr();
1288 }
1289 }
1290 };
1291
1292 // Threads::print_on() is called at safepoint by VM_PrintThreads operation.
1293 void Threads::print_on(outputStream* st, bool print_stacks,
1294 bool internal_format, bool print_concurrent_locks,
1295 bool print_extended_info) {
1296 char buf[32];
1297 st->print_raw_cr(os::local_time_string(buf, sizeof(buf)));
1298
1299 st->print_cr("Full thread dump %s (%s %s):",
1300 VM_Version::vm_name(),
1301 VM_Version::vm_release(),
1302 VM_Version::vm_info_string());
1303 st->cr();
1304
1305 #if INCLUDE_SERVICES
1306 // Dump concurrent locks
1307 ConcurrentLocksDump concurrent_locks;
1308 if (print_concurrent_locks) {
1309 concurrent_locks.dump_at_safepoint();
1310 }
1311 #endif // INCLUDE_SERVICES
1312
1313 ThreadsSMRSupport::print_info_on(st);
1314 st->cr();
1315
1316 ALL_JAVA_THREADS(p) {
1317 ResourceMark rm;
1318 p->print_on(st, print_extended_info);
1319 if (print_stacks) {
1320 if (internal_format) {
1321 p->trace_stack();
1322 } else {
1323 p->print_stack_on(st);
1324 }
1325 }
1326 st->cr();
1327 #if INCLUDE_SERVICES
1328 if (print_concurrent_locks) {
1329 concurrent_locks.print_locks_on(p, st);
1330 }
1331 #endif // INCLUDE_SERVICES
1332 }
1333
1334 PrintOnClosure cl(st);
1335 non_java_threads_do(&cl);
1336
1337 st->flush();
1338 }
1339
1340 void Threads::print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
1341 int buflen, bool* found_current) {
1342 if (this_thread != nullptr) {
1343 bool is_current = (current == this_thread);
1344 *found_current = *found_current || is_current;
1345 st->print("%s", is_current ? "=>" : " ");
1346
1347 st->print(PTR_FORMAT, p2i(this_thread));
1348 st->print(" ");
1349 this_thread->print_on_error(st, buf, buflen);
1350 st->cr();
1351 }
1352 }
1353
1354 class PrintOnErrorClosure : public ThreadClosure {
1355 outputStream* _st;
1356 Thread* _current;
1357 char* _buf;
1358 int _buflen;
1359 bool* _found_current;
1360 unsigned _num_printed;
1361 public:
1362 PrintOnErrorClosure(outputStream* st, Thread* current, char* buf,
1363 int buflen, bool* found_current) :
1364 _st(st), _current(current), _buf(buf), _buflen(buflen), _found_current(found_current),
1365 _num_printed(0) {}
1366
1367 virtual void do_thread(Thread* thread) {
1368 _num_printed++;
1369 Threads::print_on_error(thread, _st, _current, _buf, _buflen, _found_current);
1370 }
1371
1372 unsigned num_printed() const { return _num_printed; }
1373 };
1374
1375 // Threads::print_on_error() is called by fatal error handler. It's possible
1376 // that VM is not at safepoint and/or current thread is inside signal handler.
1377 // Don't print stack trace, as the stack may not be walkable. Don't allocate
1378 // memory (even in resource area), it might deadlock the error handler.
1379 void Threads::print_on_error(outputStream* st, Thread* current, char* buf,
1380 int buflen) {
1381 ThreadsSMRSupport::print_info_on(st);
1382 st->cr();
1383
1384 bool found_current = false;
1385 st->print_cr("Java Threads: ( => current thread )");
1386 unsigned num_java = 0;
1387 ALL_JAVA_THREADS(thread) {
1388 print_on_error(thread, st, current, buf, buflen, &found_current);
1389 num_java++;
1390 }
1391 st->print_cr("Total: %u", num_java);
1392 st->cr();
1393
1394 st->print_cr("Other Threads:");
1395 unsigned num_other = ((VMThread::vm_thread() != nullptr) ? 1 : 0) +
1396 ((WatcherThread::watcher_thread() != nullptr) ? 1 : 0) +
1397 ((AsyncLogWriter::instance() != nullptr) ? 1 : 0);
1398 print_on_error(VMThread::vm_thread(), st, current, buf, buflen, &found_current);
1399 print_on_error(WatcherThread::watcher_thread(), st, current, buf, buflen, &found_current);
1400 print_on_error(AsyncLogWriter::instance(), st, current, buf, buflen, &found_current);
1401
1402 if (Universe::heap() != nullptr) {
1403 PrintOnErrorClosure print_closure(st, current, buf, buflen, &found_current);
1404 Universe::heap()->gc_threads_do(&print_closure);
1405 num_other += print_closure.num_printed();
1406 }
1407
1408 if (!found_current) {
1409 st->cr();
1410 st->print("=>" PTR_FORMAT " (exited) ", p2i(current));
1411 current->print_on_error(st, buf, buflen);
1412 num_other++;
1413 st->cr();
1414 }
1415 st->print_cr("Total: %u", num_other);
1416 st->cr();
1417
1418 st->print_cr("Threads with active compile tasks:");
1419 unsigned num = print_threads_compiling(st, buf, buflen);
1420 st->print_cr("Total: %u", num);
1421 }
1422
1423 unsigned Threads::print_threads_compiling(outputStream* st, char* buf, int buflen, bool short_form) {
1424 unsigned num = 0;
1425 ALL_JAVA_THREADS(thread) {
1426 if (thread->is_Compiler_thread()) {
1427 CompilerThread* ct = (CompilerThread*) thread;
1428
1429 // Keep task in local variable for null check.
1430 // ct->_task might be set to null by concurring compiler thread
1431 // because it completed the compilation. The task is never freed,
1432 // though, just returned to a free list.
1433 CompileTask* task = ct->task();
1434 if (task != nullptr) {
1435 thread->print_name_on_error(st, buf, buflen);
1436 st->print(" ");
1437 task->print(st, nullptr, short_form, true);
1438 num++;
1439 }
1440 }
1441 }
1442 return num;
1443 }
1444
1445 void Threads::verify() {
1446 ALL_JAVA_THREADS(p) {
1447 p->verify();
1448 }
1449 VMThread* thread = VMThread::vm_thread();
1450 if (thread != nullptr) thread->verify();
1451 }