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