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