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 "c1/c1_Runtime1.hpp"
28 #include "cds/cds_globals.hpp"
29 #include "cds/cdsConfig.hpp"
30 #include "cds/classPreloader.hpp"
31 #include "cds/heapShared.hpp"
32 #include "cds/metaspaceShared.hpp"
33 #include "cds/methodProfiler.hpp"
34 #include "classfile/classLoader.hpp"
35 #include "classfile/javaClasses.hpp"
36 #include "classfile/javaThreadStatus.hpp"
37 #include "classfile/systemDictionary.hpp"
38 #include "classfile/systemDictionaryShared.hpp"
39 #include "classfile/vmClasses.hpp"
40 #include "classfile/vmSymbols.hpp"
41 #include "code/SCCache.hpp"
42 #include "compiler/compilationPolicy.hpp"
43 #include "compiler/compileBroker.hpp"
44 #include "compiler/compileTask.hpp"
45 #include "compiler/compilerThread.hpp"
46 #include "compiler/precompiler.hpp"
47 #include "gc/shared/barrierSet.hpp"
48 #include "gc/shared/barrierSetNMethod.hpp"
49 #include "gc/shared/gcVMOperations.hpp"
50 #include "gc/shared/oopStorage.hpp"
51 #include "gc/shared/oopStorageSet.hpp"
52 #include "gc/shared/stringdedup/stringDedup.hpp"
53 #include "interpreter/interpreterRuntime.hpp"
54 #include "jfr/jfrEvents.hpp"
55 #include "jvm.h"
56 #include "jvmtifiles/jvmtiEnv.hpp"
57 #include "logging/log.hpp"
58 #include "logging/logAsyncWriter.hpp"
59 #include "logging/logConfiguration.hpp"
60 #include "memory/allocation.inline.hpp"
61 #include "memory/iterator.hpp"
62 #include "memory/oopFactory.hpp"
63 #include "memory/resourceArea.hpp"
64 #include "memory/universe.hpp"
65 #include "nmt/memTracker.hpp"
66 #include "oops/instanceKlass.hpp"
67 #include "oops/klass.inline.hpp"
68 #include "oops/oop.inline.hpp"
69 #include "opto/runtime.hpp"
70 #include "oops/symbol.hpp"
71 #include "prims/jvm_misc.hpp"
72 #include "prims/jvmtiAgentList.hpp"
73 #include "prims/jvmtiEnvBase.hpp"
74 #include "runtime/arguments.hpp"
75 #include "runtime/fieldDescriptor.inline.hpp"
76 #include "runtime/flags/jvmFlagLimit.hpp"
77 #include "runtime/globals.hpp"
78 #include "runtime/handles.inline.hpp"
79 #include "runtime/interfaceSupport.inline.hpp"
80 #include "runtime/java.hpp"
81 #include "runtime/javaCalls.hpp"
82 #include "runtime/javaThread.inline.hpp"
83 #include "runtime/jniHandles.inline.hpp"
84 #include "runtime/jniPeriodicChecker.hpp"
85 #include "runtime/lockStack.inline.hpp"
86 #include "runtime/monitorDeflationThread.hpp"
87 #include "runtime/mutexLocker.hpp"
88 #include "runtime/nonJavaThread.hpp"
89 #include "runtime/objectMonitor.inline.hpp"
90 #include "runtime/osThread.hpp"
91 #include "runtime/safepoint.hpp"
92 #include "runtime/safepointMechanism.inline.hpp"
93 #include "runtime/safepointVerifiers.hpp"
94 #include "runtime/serviceThread.hpp"
95 #include "runtime/sharedRuntime.hpp"
96 #include "runtime/stackWatermarkSet.inline.hpp"
97 #include "runtime/statSampler.hpp"
98 #include "runtime/stubCodeGenerator.hpp"
99 #include "runtime/thread.inline.hpp"
100 #include "runtime/threadSMR.inline.hpp"
101 #include "runtime/threads.hpp"
102 #include "runtime/timer.hpp"
103 #include "runtime/timerTrace.hpp"
104 #include "runtime/trimNativeHeap.hpp"
105 #include "runtime/vmOperations.hpp"
106 #include "runtime/vm_version.hpp"
107 #include "services/attachListener.hpp"
108 #include "services/management.hpp"
109 #include "services/threadIdTable.hpp"
110 #include "services/threadService.hpp"
111 #include "utilities/dtrace.hpp"
112 #include "utilities/events.hpp"
113 #include "utilities/macros.hpp"
114 #include "utilities/vmError.hpp"
115 #if INCLUDE_JVMCI
116 #include "jvmci/jvmci.hpp"
117 #include "jvmci/jvmciEnv.hpp"
118 #endif
119 #ifdef COMPILER2
120 #include "opto/idealGraphPrinter.hpp"
121 #endif
122 #if INCLUDE_JFR
123 #include "jfr/jfr.hpp"
124 #endif
125
126 // Initialization after module runtime initialization
127 void universe_post_module_init(); // must happen after call_initPhase2
128
129
130 static void initialize_class(Symbol* class_name, TRAPS) {
131 Klass* klass = SystemDictionary::resolve_or_fail(class_name, true, CHECK);
132 InstanceKlass::cast(klass)->initialize(CHECK);
133 }
134
135
136 // Creates the initial ThreadGroup
137 static Handle create_initial_thread_group(TRAPS) {
138 Handle system_instance = JavaCalls::construct_new_instance(
139 vmClasses::ThreadGroup_klass(),
140 vmSymbols::void_method_signature(),
141 CHECK_NH);
142 Universe::set_system_thread_group(system_instance());
143
144 Handle string = java_lang_String::create_from_str("main", CHECK_NH);
145 Handle main_instance = JavaCalls::construct_new_instance(
146 vmClasses::ThreadGroup_klass(),
147 vmSymbols::threadgroup_string_void_signature(),
148 system_instance,
149 string,
150 CHECK_NH);
151 return main_instance;
152 }
153
154 // Creates the initial Thread, and sets it to running.
155 static void create_initial_thread(Handle thread_group, JavaThread* thread,
156 TRAPS) {
157 InstanceKlass* ik = vmClasses::Thread_klass();
158 assert(ik->is_initialized(), "must be");
159 instanceHandle thread_oop = ik->allocate_instance_handle(CHECK);
160
161 // Cannot use JavaCalls::construct_new_instance because the java.lang.Thread
162 // constructor calls Thread.current(), which must be set here for the
163 // initial thread.
164 java_lang_Thread::set_thread(thread_oop(), thread);
165 thread->set_threadOopHandles(thread_oop());
166
167 Handle string = java_lang_String::create_from_str("main", CHECK);
168
169 JavaValue result(T_VOID);
170 JavaCalls::call_special(&result, thread_oop,
171 ik,
172 vmSymbols::object_initializer_name(),
173 vmSymbols::threadgroup_string_void_signature(),
174 thread_group,
175 string,
176 CHECK);
177
178 // Set thread status to running since main thread has
179 // been started and running.
180 java_lang_Thread::set_thread_status(thread_oop(),
181 JavaThreadStatus::RUNNABLE);
182 }
183
184 // Extract version and vendor specific information from
185 // java.lang.VersionProps fields.
186 // Returned char* is allocated in the thread's resource area
187 // so must be copied for permanency.
188 static const char* get_java_version_info(InstanceKlass* ik,
189 Symbol* field_name) {
190 fieldDescriptor fd;
191 bool found = ik != nullptr &&
192 ik->find_local_field(field_name,
193 vmSymbols::string_signature(), &fd);
194 if (found) {
195 oop name_oop = ik->java_mirror()->obj_field(fd.offset());
196 if (name_oop == nullptr) {
197 return nullptr;
198 }
199 const char* name = java_lang_String::as_utf8_string(name_oop);
200 return name;
201 } else {
202 return nullptr;
203 }
204 }
205
206 // ======= Threads ========
207
208 // The Threads class links together all active threads, and provides
209 // operations over all threads. It is protected by the Threads_lock,
210 // which is also used in other global contexts like safepointing.
211 // ThreadsListHandles are used to safely perform operations on one
212 // or more threads without the risk of the thread exiting during the
213 // operation.
214 //
215 // Note: The Threads_lock is currently more widely used than we
216 // would like. We are actively migrating Threads_lock uses to other
217 // mechanisms in order to reduce Threads_lock contention.
218
219 int Threads::_number_of_threads = 0;
220 int Threads::_number_of_non_daemon_threads = 0;
221 int Threads::_return_code = 0;
222 uintx Threads::_thread_claim_token = 1; // Never zero.
223
224 #ifdef ASSERT
225 bool Threads::_vm_complete = false;
226 #endif
227
228 // General purpose hook into Java code, run once when the VM is initialized.
229 // The Java library method itself may be changed independently from the VM.
230 static void call_postVMInitHook(TRAPS) {
231 Klass* klass = SystemDictionary::resolve_or_null(vmSymbols::jdk_internal_vm_PostVMInitHook(), THREAD);
232 if (klass != nullptr) {
233 JavaValue result(T_VOID);
234 JavaCalls::call_static(&result, klass, vmSymbols::run_method_name(),
235 vmSymbols::void_method_signature(),
236 CHECK);
237 }
238 }
239
240 // All NonJavaThreads (i.e., every non-JavaThread in the system).
241 void Threads::non_java_threads_do(ThreadClosure* tc) {
242 NoSafepointVerifier nsv;
243 for (NonJavaThread::Iterator njti; !njti.end(); njti.step()) {
244 tc->do_thread(njti.current());
245 }
246 }
247
248 // All JavaThreads
249 #define ALL_JAVA_THREADS(X) \
250 for (JavaThread* X : *ThreadsSMRSupport::get_java_thread_list())
251
252 // All JavaThreads
253 void Threads::java_threads_do(ThreadClosure* tc) {
254 assert_locked_or_safepoint(Threads_lock);
255 // ALL_JAVA_THREADS iterates through all JavaThreads.
256 ALL_JAVA_THREADS(p) {
257 tc->do_thread(p);
258 }
259 }
260
261 // All JavaThreads + all non-JavaThreads (i.e., every thread in the system).
262 void Threads::threads_do(ThreadClosure* tc) {
263 assert_locked_or_safepoint(Threads_lock);
264 java_threads_do(tc);
265 non_java_threads_do(tc);
266 }
267
268 void Threads::possibly_parallel_threads_do(bool is_par, ThreadClosure* tc) {
269 assert_at_safepoint();
270
271 uintx claim_token = Threads::thread_claim_token();
272 ALL_JAVA_THREADS(p) {
273 if (p->claim_threads_do(is_par, claim_token)) {
274 tc->do_thread(p);
275 }
276 }
277 for (NonJavaThread::Iterator njti; !njti.end(); njti.step()) {
278 Thread* current = njti.current();
279 if (current->claim_threads_do(is_par, claim_token)) {
280 tc->do_thread(current);
281 }
282 }
283 }
284
285 // The system initialization in the library has three phases.
286 //
287 // Phase 1: java.lang.System class initialization
288 // java.lang.System is a primordial class loaded and initialized
289 // by the VM early during startup. java.lang.System.<clinit>
290 // only does registerNatives and keeps the rest of the class
291 // initialization work later until thread initialization completes.
292 //
293 // System.initPhase1 initializes the system properties, the static
294 // fields in, out, and err. Set up java signal handlers, OS-specific
295 // system settings, and thread group of the main thread.
296 static void call_initPhase1(TRAPS) {
297 Klass* klass = vmClasses::System_klass();
298 JavaValue result(T_VOID);
299 JavaCalls::call_static(&result, klass, vmSymbols::initPhase1_name(),
300 vmSymbols::void_method_signature(), CHECK);
301 }
302
303 // Phase 2. Module system initialization
304 // This will initialize the module system. Only java.base classes
305 // can be loaded until phase 2 completes.
306 //
307 // Call System.initPhase2 after the compiler initialization and jsr292
308 // classes get initialized because module initialization runs a lot of java
309 // code, that for performance reasons, should be compiled. Also, this will
310 // enable the startup code to use lambda and other language features in this
311 // phase and onward.
312 //
313 // After phase 2, The VM will begin search classes from -Xbootclasspath/a.
314 static void call_initPhase2(TRAPS) {
315 TraceTime timer("Initialize module system", TRACETIME_LOG(Info, startuptime));
316
317 Klass* klass = vmClasses::System_klass();
318
319 JavaValue result(T_INT);
320 JavaCallArguments args;
321 args.push_int(DisplayVMOutputToStderr);
322 args.push_int(log_is_enabled(Debug, init)); // print stack trace if exception thrown
323 JavaCalls::call_static(&result, klass, vmSymbols::initPhase2_name(),
324 vmSymbols::boolean_boolean_int_signature(), &args, CHECK);
325 if (result.get_jint() != JNI_OK) {
326 vm_exit_during_initialization(); // no message or exception
327 }
328
329 universe_post_module_init();
330
331 // Preload all boot classes outside of java.base module
332 ClassPreloader::runtime_preload(THREAD, Handle());
333 if (CDSConfig::is_using_full_module_graph()) {
334 // SystemDictionary::java_{platform,system}_loader are already assigned. We can spin
335 // this up a little quicker.
336 assert(SystemDictionary::java_platform_loader() != nullptr, "must be");
337 assert(SystemDictionary::java_system_loader() != nullptr, "must be");
338 ClassPreloader::runtime_preload(THREAD, Handle(THREAD, SystemDictionary::java_platform_loader()));
339 ClassPreloader::runtime_preload(THREAD, Handle(THREAD, SystemDictionary::java_system_loader()));
340 }
341 }
342
343 // Phase 3. final setup - set security manager, system class loader and TCCL
344 //
345 // This will instantiate and set the security manager, set the system class
346 // loader as well as the thread context class loader. The security manager
347 // and system class loader may be a custom class loaded from -Xbootclasspath/a,
348 // other modules or the application's classpath.
349 static void call_initPhase3(TRAPS) {
350 Klass* klass = vmClasses::System_klass();
351 JavaValue result(T_VOID);
352 JavaCalls::call_static(&result, klass, vmSymbols::initPhase3_name(),
353 vmSymbols::void_method_signature(), CHECK);
354 }
355
356 void Threads::initialize_java_lang_classes(JavaThread* main_thread, TRAPS) {
357 TraceTime timer("Initialize java.lang classes", TRACETIME_LOG(Info, startuptime));
358
359 initialize_class(vmSymbols::java_lang_String(), CHECK);
360
361 // Inject CompactStrings value after the static initializers for String ran.
362 java_lang_String::set_compact_strings(CompactStrings);
363
364 // Initialize java_lang.System (needed before creating the thread)
365 initialize_class(vmSymbols::java_lang_System(), CHECK);
366 // The VM creates & returns objects of this class. Make sure it's initialized.
367 initialize_class(vmSymbols::java_lang_Class(), CHECK);
368 initialize_class(vmSymbols::java_lang_ThreadGroup(), CHECK);
369 Handle thread_group = create_initial_thread_group(CHECK);
370 Universe::set_main_thread_group(thread_group());
371 initialize_class(vmSymbols::java_lang_Thread(), CHECK);
372 create_initial_thread(thread_group, main_thread, CHECK);
373
374 HeapShared::init_box_classes(CHECK);
375
376 // The VM creates objects of this class.
377 initialize_class(vmSymbols::java_lang_Module(), CHECK);
378
379 #ifdef ASSERT
380 InstanceKlass *k = vmClasses::UnsafeConstants_klass();
381 assert(k->is_not_initialized(), "UnsafeConstants should not already be initialized");
382 #endif
383
384 // initialize the hardware-specific constants needed by Unsafe
385 initialize_class(vmSymbols::jdk_internal_misc_UnsafeConstants(), CHECK);
386 jdk_internal_misc_UnsafeConstants::set_unsafe_constants();
387
388 // The VM preresolves methods to these classes. Make sure that they get initialized
389 initialize_class(vmSymbols::java_lang_reflect_Method(), CHECK);
390 initialize_class(vmSymbols::java_lang_ref_Finalizer(), CHECK);
391
392 // Phase 1 of the system initialization in the library, java.lang.System class initialization
393 call_initPhase1(CHECK);
394
395 // Get the Java runtime name, version, and vendor info after java.lang.System is initialized.
396 // Some values are actually configure-time constants but some can be set via the jlink tool and
397 // so must be read dynamically. We treat them all the same.
398 InstanceKlass* ik = SystemDictionary::find_instance_klass(THREAD, vmSymbols::java_lang_VersionProps(),
399 Handle(), Handle());
400 {
401 ResourceMark rm(main_thread);
402 JDK_Version::set_java_version(get_java_version_info(ik, vmSymbols::java_version_name()));
403
404 JDK_Version::set_runtime_name(get_java_version_info(ik, vmSymbols::java_runtime_name_name()));
405
406 JDK_Version::set_runtime_version(get_java_version_info(ik, vmSymbols::java_runtime_version_name()));
407
408 JDK_Version::set_runtime_vendor_version(get_java_version_info(ik, vmSymbols::java_runtime_vendor_version_name()));
409
410 JDK_Version::set_runtime_vendor_vm_bug_url(get_java_version_info(ik, vmSymbols::java_runtime_vendor_vm_bug_url_name()));
411 }
412
413 // an instance of OutOfMemory exception has been allocated earlier
414 initialize_class(vmSymbols::java_lang_OutOfMemoryError(), CHECK);
415 initialize_class(vmSymbols::java_lang_NullPointerException(), CHECK);
416 initialize_class(vmSymbols::java_lang_ClassCastException(), CHECK);
417 initialize_class(vmSymbols::java_lang_ArrayStoreException(), CHECK);
418 initialize_class(vmSymbols::java_lang_ArithmeticException(), CHECK);
419 initialize_class(vmSymbols::java_lang_StackOverflowError(), CHECK);
420 initialize_class(vmSymbols::java_lang_IllegalMonitorStateException(), CHECK);
421 initialize_class(vmSymbols::java_lang_IllegalArgumentException(), CHECK);
422 }
423
424 bool Threads::initialize_compilation(TRAPS) {
425 // initialize compiler(s)
426 bool force_JVMCI_initialization = false;
427
428 #if defined(COMPILER1) || COMPILER2_OR_JVMCI
429 bool init_compilation = true;
430 #if INCLUDE_JVMCI
431 if (EnableJVMCI) {
432 // Initialize JVMCI eagerly when it is explicitly requested.
433 // Or when JVMCILibDumpJNIConfig or JVMCIPrintProperties is enabled.
434 force_JVMCI_initialization = EagerJVMCI || JVMCIPrintProperties || JVMCILibDumpJNIConfig;
435 if (!force_JVMCI_initialization && UseJVMCICompiler && !UseJVMCINativeLibrary && (!UseInterpreter || !BackgroundCompilation)) {
436 // Force initialization of jarjvmci otherwise requests for blocking
437 // compilations will not actually block until jarjvmci is initialized.
438 force_JVMCI_initialization = true;
439 }
440 if (JVMCIPrintProperties || JVMCILibDumpJNIConfig) {
441 // Both JVMCILibDumpJNIConfig and JVMCIPrintProperties exit the VM
442 // so compilation should be disabled. This prevents dumping or
443 // printing from happening more than once.
444 init_compilation = false;
445 }
446 }
447 #endif
448 if (init_compilation) {
449 CompileBroker::compilation_init(CHECK_false);
450 }
451 #endif
452
453 return force_JVMCI_initialization;
454 }
455
456 void Threads::initialize_jsr292_core_classes(TRAPS) {
457 TraceTime timer("Initialize java.lang.invoke classes", TRACETIME_LOG(Info, startuptime));
458
459 initialize_class(vmSymbols::java_lang_invoke_MethodHandle(), CHECK);
460 initialize_class(vmSymbols::java_lang_invoke_ResolvedMethodName(), CHECK);
461 initialize_class(vmSymbols::java_lang_invoke_MemberName(), CHECK);
462 initialize_class(vmSymbols::java_lang_invoke_MethodHandleNatives(), CHECK);
463
464 if (UseSharedSpaces) {
465 HeapShared::initialize_java_lang_invoke(CHECK);
466 }
467 }
468
469 jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) {
470 extern void JDK_Version_init();
471
472 // Preinitialize version info.
473 VM_Version::early_initialize();
474
475 // Check version
476 if (!is_supported_jni_version(args->version)) return JNI_EVERSION;
477
478 // Initialize library-based TLS
479 ThreadLocalStorage::init();
480
481 // Initialize the output stream module
482 ostream_init();
483
484 // Process java launcher properties.
485 Arguments::process_sun_java_launcher_properties(args);
486
487 // Initialize the os module
488 os::init();
489
490 MACOS_AARCH64_ONLY(os::current_thread_enable_wx(WXWrite));
491
492 // Record VM creation timing statistics
493 TraceVmCreationTime create_vm_timer;
494 create_vm_timer.start();
495
496 // Initialize system properties.
497 Arguments::init_system_properties();
498
499 // So that JDK version can be used as a discriminator when parsing arguments
500 JDK_Version_init();
501
502 // Update/Initialize System properties after JDK version number is known
503 Arguments::init_version_specific_system_properties();
504
505 // Make sure to initialize log configuration *before* parsing arguments
506 LogConfiguration::initialize(create_vm_timer.begin_time());
507
508 // Parse arguments
509 // Note: this internally calls os::init_container_support()
510 jint parse_result = Arguments::parse(args);
511 if (parse_result != JNI_OK) return parse_result;
512
513 // Initialize NMT right after argument parsing to keep the pre-NMT-init window small.
514 MemTracker::initialize();
515
516 os::init_before_ergo();
517
518 jint ergo_result = Arguments::apply_ergo();
519 if (ergo_result != JNI_OK) return ergo_result;
520
521 // Final check of all ranges after ergonomics which may change values.
522 if (!JVMFlagLimit::check_all_ranges()) {
523 return JNI_EINVAL;
524 }
525
526 // Final check of all 'AfterErgo' constraints after ergonomics which may change values.
527 bool constraint_result = JVMFlagLimit::check_all_constraints(JVMFlagConstraintPhase::AfterErgo);
528 if (!constraint_result) {
529 return JNI_EINVAL;
530 }
531
532 if (PauseAtStartup) {
533 os::pause();
534 }
535
536 HOTSPOT_VM_INIT_BEGIN();
537
538 // Timing (must come after argument parsing)
539 TraceTime timer("Create VM", TRACETIME_LOG(Info, startuptime));
540
541 // Initialize the os module after parsing the args
542 jint os_init_2_result = os::init_2();
543 if (os_init_2_result != JNI_OK) return os_init_2_result;
544
545 #ifdef CAN_SHOW_REGISTERS_ON_ASSERT
546 // Initialize assert poison page mechanism.
547 if (ShowRegistersOnAssert) {
548 initialize_assert_poison();
549 }
550 #endif // CAN_SHOW_REGISTERS_ON_ASSERT
551
552 SafepointMechanism::initialize();
553
554 jint adjust_after_os_result = Arguments::adjust_after_os();
555 if (adjust_after_os_result != JNI_OK) return adjust_after_os_result;
556
557 // Initialize output stream logging
558 ostream_init_log();
559
560 // Launch -agentlib/-agentpath and converted -Xrun agents
561 JvmtiAgentList::load_agents();
562
563 // Initialize Threads state
564 _number_of_threads = 0;
565 _number_of_non_daemon_threads = 0;
566
567 // Initialize global data structures and create system classes in heap
568 vm_init_globals();
569
570 #if INCLUDE_JVMCI
571 if (JVMCICounterSize > 0) {
572 JavaThread::_jvmci_old_thread_counters = NEW_C_HEAP_ARRAY(jlong, JVMCICounterSize, mtJVMCI);
573 memset(JavaThread::_jvmci_old_thread_counters, 0, sizeof(jlong) * JVMCICounterSize);
574 } else {
575 JavaThread::_jvmci_old_thread_counters = nullptr;
576 }
577 #endif // INCLUDE_JVMCI
578
579 // Initialize OopStorage for threadObj
580 JavaThread::_thread_oop_storage = OopStorageSet::create_strong("Thread OopStorage", mtThread);
581
582 // Attach the main thread to this os thread
583 JavaThread* main_thread = new JavaThread();
584 main_thread->set_thread_state(_thread_in_vm);
585 main_thread->initialize_thread_current();
586 // must do this before set_active_handles
587 main_thread->record_stack_base_and_size();
588 main_thread->register_thread_stack_with_NMT();
589 main_thread->set_active_handles(JNIHandleBlock::allocate_block());
590 MACOS_AARCH64_ONLY(main_thread->init_wx());
591
592 MutexLockerImpl::init_counters(); // depends on mutex_init(), perfMemory_init(), and Thread::initialize_thread_current().
593
594 if (!main_thread->set_as_starting_thread()) {
595 vm_shutdown_during_initialization(
596 "Failed necessary internal allocation. Out of swap space");
597 main_thread->smr_delete();
598 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
599 return JNI_ENOMEM;
600 }
601
602 // Enable guard page *after* os::create_main_thread(), otherwise it would
603 // crash Linux VM, see notes in os_linux.cpp.
604 main_thread->stack_overflow_state()->create_stack_guard_pages();
605
606 // Initialize Java-Level synchronization subsystem
607 ObjectMonitor::Initialize();
608 ObjectSynchronizer::initialize();
609
610 Deoptimization::init_counters();
611 VMThread::init_counters();
612
613 // Initialize global modules
614 jint status = init_globals();
615 if (status != JNI_OK) {
616 main_thread->smr_delete();
617 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
618 return status;
619 }
620 if (xtty != nullptr)
621 xtty->elem("vm_main_thread thread='" UINTX_FORMAT "'",
622 (uintx) main_thread->osthread()->thread_id());
623
624 // Create WatcherThread as soon as we can since we need it in case
625 // of hangs during error reporting.
626 WatcherThread::start();
627
628 // Add main_thread to threads list to finish barrier setup with
629 // on_thread_attach. Should be before starting to build Java objects in
630 // init_globals2, which invokes barriers.
631 {
632 MutexLocker mu(Threads_lock);
633 Threads::add(main_thread);
634 }
635
636 status = init_globals2();
637 if (status != JNI_OK) {
638 Threads::remove(main_thread, false);
639 // It is possible that we managed to fully initialize Universe but have then
640 // failed by throwing an exception. In that case our caller JNI_CreateJavaVM
641 // will want to report it, so we can't delete the main thread.
642 if (!main_thread->has_pending_exception()) {
643 main_thread->smr_delete();
644 }
645 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
646 return status;
647 }
648
649 JFR_ONLY(Jfr::on_create_vm_1();)
650
651 // Should be done after the heap is fully created
652 main_thread->cache_global_variables();
653
654 // Any JVMTI raw monitors entered in onload will transition into
655 // real raw monitor. VM is setup enough here for raw monitor enter.
656 JvmtiExport::transition_pending_onload_raw_monitors();
657
658 // Create the VMThread
659 { TraceTime timer("Start VMThread", TRACETIME_LOG(Info, startuptime));
660
661 VMThread::create();
662 VMThread* vmthread = VMThread::vm_thread();
663
664 if (!os::create_thread(vmthread, os::vm_thread)) {
665 vm_exit_during_initialization("Cannot create VM thread. "
666 "Out of system resources.");
667 }
668
669 // Wait for the VM thread to become ready, and VMThread::run to initialize
670 // Monitors can have spurious returns, must always check another state flag
671 {
672 MonitorLocker ml(Notify_lock);
673 os::start_thread(vmthread);
674 while (!vmthread->is_running()) {
675 ml.wait();
676 }
677 }
678 }
679
680 assert(Universe::is_fully_initialized(), "not initialized");
681 if (VerifyDuringStartup) {
682 // Make sure we're starting with a clean slate.
683 VM_Verify verify_op;
684 VMThread::execute(&verify_op);
685 }
686
687 // We need this to update the java.vm.info property in case any flags used
688 // to initially define it have been changed. This is needed for both CDS
689 // since UseSharedSpaces may be changed after java.vm.info
690 // is initially computed. See Abstract_VM_Version::vm_info_string().
691 // This update must happen before we initialize the java classes, but
692 // after any initialization logic that might modify the flags.
693 Arguments::update_vm_info_property(VM_Version::vm_info_string());
694
695 JavaThread* THREAD = JavaThread::current(); // For exception macros.
696 HandleMark hm(THREAD);
697
698 // Always call even when there are not JVMTI environments yet, since environments
699 // may be attached late and JVMTI must track phases of VM execution
700 JvmtiExport::enter_early_start_phase();
701
702 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
703 JvmtiExport::post_early_vm_start();
704
705 // Launch -Xrun agents early if EagerXrunInit is set
706 if (EagerXrunInit) {
707 JvmtiAgentList::load_xrun_agents();
708 }
709
710 initialize_java_lang_classes(main_thread, CHECK_JNI_ERR);
711
712 quicken_jni_functions();
713
714 // No more stub generation allowed after that point.
715 StubCodeDesc::freeze();
716
717 // Set flag that basic initialization has completed. Used by exceptions and various
718 // debug stuff, that does not work until all basic classes have been initialized.
719 set_init_completed();
720
721 LogConfiguration::post_initialize();
722 Metaspace::post_initialize();
723 MutexLockerImpl::post_initialize();
724
725 HOTSPOT_VM_INIT_END();
726
727 // record VM initialization completion time
728 #if INCLUDE_MANAGEMENT
729 Management::record_vm_init_completed();
730 #endif // INCLUDE_MANAGEMENT
731
732 log_info(os)("Initialized VM with process ID %d", os::current_process_id());
733
734 // Signal Dispatcher needs to be started before VMInit event is posted
735 os::initialize_jdk_signal_support(CHECK_JNI_ERR);
736
737 // Start Attach Listener if +StartAttachListener or it can't be started lazily
738 if (!DisableAttachMechanism) {
739 AttachListener::vm_start();
740 if (StartAttachListener || AttachListener::init_at_startup()) {
741 AttachListener::init();
742 }
743 }
744
745 // Launch -Xrun agents if EagerXrunInit is not set.
746 if (!EagerXrunInit) {
747 JvmtiAgentList::load_xrun_agents();
748 }
749
750 Arena::start_chunk_pool_cleaner_task();
751
752 // Start the service thread
753 // The service thread enqueues JVMTI deferred events and does various hashtable
754 // and other cleanups. Needs to start before the compilers start posting events.
755 ServiceThread::initialize();
756
757 // Start the monitor deflation thread:
758 MonitorDeflationThread::initialize();
759
760 // Start the method sampler
761 MethodProfiler::initialize();
762
763 bool force_JVMCI_initialization = initialize_compilation(CHECK_JNI_ERR);
764
765 ClassPreloader::init_javabase_preloaded_classes(CHECK_JNI_ERR);
766
767 // Start string deduplication thread if requested.
768 if (StringDedup::is_enabled()) {
769 StringDedup::start();
770 }
771
772 // Pre-initialize some JSR292 core classes to avoid deadlock during class loading.
773 // It is done after compilers are initialized, because otherwise compilations of
774 // signature polymorphic MH intrinsics can be missed
775 // (see SystemDictionary::find_method_handle_intrinsic).
776 initialize_jsr292_core_classes(CHECK_JNI_ERR);
777
778 // This will initialize the module system. Only java.base classes can be
779 // loaded until phase 2 completes
780 call_initPhase2(CHECK_JNI_ERR);
781
782 JFR_ONLY(Jfr::on_create_vm_2();)
783
784 // Always call even when there are not JVMTI environments yet, since environments
785 // may be attached late and JVMTI must track phases of VM execution
786 JvmtiExport::enter_start_phase();
787
788 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
789 JvmtiExport::post_vm_start();
790
791 // Final system initialization including security manager and system class loader
792 call_initPhase3(CHECK_JNI_ERR);
793
794 // cache the system and platform class loaders
795 SystemDictionary::compute_java_loaders(CHECK_JNI_ERR);
796
797 // Initiate replay training processing once preloading is over.
798 CompileBroker::init_training_replay();
799
800 ClassPreloader::replay_training_at_init_for_preloaded_classes(CHECK_JNI_ERR);
801
802 if (Continuations::enabled()) {
803 // Initialize Continuation class now so that failure to create enterSpecial/doYield
804 // special nmethods due to limited CodeCache size can be treated as a fatal error at
805 // startup with the proper message that CodeCache size is too small.
806 initialize_class(vmSymbols::jdk_internal_vm_Continuation(), CHECK_JNI_ERR);
807 }
808
809 #if INCLUDE_CDS
810 // capture the module path info from the ModuleEntryTable
811 ClassLoader::initialize_module_path(THREAD);
812 if (HAS_PENDING_EXCEPTION) {
813 java_lang_Throwable::print(PENDING_EXCEPTION, tty);
814 vm_exit_during_initialization("ClassLoader::initialize_module_path() failed unexpectedly");
815 }
816 #endif
817
818 #if INCLUDE_JVMCI
819 if (force_JVMCI_initialization) {
820 JVMCI::initialize_compiler(CHECK_JNI_ERR);
821 }
822 #endif
823
824 if (PrecompileCode) {
825 Precompiler::compile_cached_code(CHECK_JNI_ERR);
826 if (PrecompileOnlyAndExit) {
827 SCCache::close();
828 log_vm_init_stats(true /* use_tty */);
829 vm_direct_exit(0, "Code precompiation is over");
830 }
831 }
832
833 #if defined(COMPILER2)
834 // Pre-load cached compiled methods
835 SCCache::preload_code(CHECK_JNI_ERR);
836 #endif
837
838 if (NativeHeapTrimmer::enabled()) {
839 NativeHeapTrimmer::initialize();
840 }
841
842 // Always call even when there are not JVMTI environments yet, since environments
843 // may be attached late and JVMTI must track phases of VM execution
844 JvmtiExport::enter_live_phase();
845
846 // Make perfmemory accessible
847 PerfMemory::set_accessible(true);
848
849 // Notify JVMTI agents that VM initialization is complete - nop if no agents.
850 JvmtiExport::post_vm_initialized();
851
852 JFR_ONLY(Jfr::on_create_vm_3();)
853
854 #if INCLUDE_MANAGEMENT
855 Management::initialize(THREAD);
856
857 if (HAS_PENDING_EXCEPTION) {
858 // management agent fails to start possibly due to
859 // configuration problem and is responsible for printing
860 // stack trace if appropriate. Simply exit VM.
861 vm_exit(1);
862 }
863 #endif // INCLUDE_MANAGEMENT
864
865 StatSampler::engage();
866 if (CheckJNICalls) JniPeriodicChecker::engage();
867
868 call_postVMInitHook(THREAD);
869 // The Java side of PostVMInitHook.run must deal with all
870 // exceptions and provide means of diagnosis.
871 if (HAS_PENDING_EXCEPTION) {
872 CLEAR_PENDING_EXCEPTION;
873 }
874
875 // Let WatcherThread run all registered periodic tasks now.
876 // NOTE: All PeriodicTasks should be registered by now. If they
877 // aren't, late joiners might appear to start slowly (we might
878 // take a while to process their first tick).
879 WatcherThread::run_all_tasks();
880
881 create_vm_timer.end();
882 #ifdef ASSERT
883 _vm_complete = true;
884 #endif
885
886 if (CDSConfig::is_dumping_classic_static_archive()) {
887 // Classic -Xshare:dump, aka "old workflow"
888 MetaspaceShared::preload_and_dump(CHECK_JNI_ERR);
889 } else if (CDSConfig::is_dumping_final_static_archive()) {
890 // TODO: copy the verification and loader constraints from preimage to final image
891 // TODO: load archived classes for custom loaders as well.
892 log_info(cds)("Dumping final image of CacheDataStore %s", CacheDataStore);
893 MetaspaceShared::preload_and_dump(CHECK_JNI_ERR);
894 vm_direct_exit(0, "CacheDataStore dumping is complete");
895 }
896
897 log_info(init)("At VM initialization completion:");
898 log_vm_init_stats(false /* use_tty */);
899
900 if (UsePerfData) {
901 if (ProfileVMLocks) {
902 main_thread->set_profile_vm_locks(true);
903 }
904 if (ProfileVMCalls) {
905 main_thread->set_profile_vm_calls(true);
906 }
907 if (ProfileRuntimeCalls) {
908 main_thread->set_profile_rt_calls(true);
909 }
910 if (ProfileVMOps) {
911 main_thread->set_profile_vm_ops(true);
912 }
913 }
914
915 return JNI_OK;
916 }
917
918 // Threads::destroy_vm() is normally called from jni_DestroyJavaVM() when
919 // the program falls off the end of main(). Another VM exit path is through
920 // vm_exit(), when the program calls System.exit() to return a value, or when
921 // there is a serious error in VM.
922 // These two separate shutdown paths are not exactly the same, but they share
923 // Shutdown.shutdown() at Java level and before_exit() and VM_Exit op at VM level.
924 //
925 // Shutdown sequence:
926 // + Shutdown native memory tracking if it is on
927 // + Wait until we are the last non-daemon thread to execute
928 // <-- every thing is still working at this moment -->
929 // + Call java.lang.Shutdown.shutdown(), which will invoke Java level
930 // shutdown hooks
931 // + Call before_exit(), prepare for VM exit
932 // > run VM level shutdown hooks (they are registered through JVM_OnExit(),
933 // currently the only user of this mechanism is File.deleteOnExit())
934 // > stop StatSampler, watcher thread,
935 // post thread end and vm death events to JVMTI,
936 // stop signal thread
937 // + Call JavaThread::exit(), it will:
938 // > release JNI handle blocks, remove stack guard pages
939 // > remove this thread from Threads list
940 // <-- no more Java code from this thread after this point -->
941 // + Stop VM thread, it will bring the remaining VM to a safepoint and stop
942 // the compiler threads at safepoint
943 // <-- do not use anything that could get blocked by Safepoint -->
944 // + Disable tracing at JNI/JVM barriers
945 // + Set _vm_exited flag for threads that are still running native code
946 // + Call exit_globals()
947 // > deletes tty
948 // > deletes PerfMemory resources
949 // + Delete this thread
950 // + Return to caller
951
952 void Threads::destroy_vm() {
953 JavaThread* thread = JavaThread::current();
954
955 #ifdef ASSERT
956 _vm_complete = false;
957 #endif
958 // Wait until we are the last non-daemon thread to execute, or
959 // if we are a daemon then wait until the last non-daemon thread has
960 // executed.
961 bool daemon = java_lang_Thread::is_daemon(thread->threadObj());
962 int expected = daemon ? 0 : 1;
963 {
964 MonitorLocker nu(Threads_lock);
965 while (Threads::number_of_non_daemon_threads() > expected)
966 // This wait should make safepoint checks, wait without a timeout.
967 nu.wait(0);
968 }
969
970 EventShutdown e;
971 if (e.should_commit()) {
972 e.set_reason("No remaining non-daemon Java threads");
973 e.commit();
974 }
975
976 // Hang forever on exit if we are reporting an error.
977 if (ShowMessageBoxOnError && VMError::is_error_reported()) {
978 os::infinite_sleep();
979 }
980 os::wait_for_keypress_at_exit();
981
982 // run Java level shutdown hooks
983 thread->invoke_shutdown_hooks();
984
985 before_exit(thread);
986
987 thread->exit(true);
988
989 // We are no longer on the main thread list but could still be in a
990 // secondary list where another thread may try to interact with us.
991 // So wait until all such interactions are complete before we bring
992 // the VM to the termination safepoint. Normally this would be done
993 // using thread->smr_delete() below where we delete the thread, but
994 // we can't call that after the termination safepoint is active as
995 // we will deadlock on the Threads_lock. Once all interactions are
996 // complete it is safe to directly delete the thread at any time.
997 ThreadsSMRSupport::wait_until_not_protected(thread);
998
999 // Stop VM thread.
1000 {
1001 // 4945125 The vm thread comes to a safepoint during exit.
1002 // GC vm_operations can get caught at the safepoint, and the
1003 // heap is unparseable if they are caught. Grab the Heap_lock
1004 // to prevent this. The GC vm_operations will not be able to
1005 // queue until after the vm thread is dead. After this point,
1006 // we'll never emerge out of the safepoint before the VM exits.
1007 // Assert that the thread is terminated so that acquiring the
1008 // Heap_lock doesn't cause the terminated thread to participate in
1009 // the safepoint protocol.
1010
1011 assert(thread->is_terminated(), "must be terminated here");
1012 MutexLocker ml(Heap_lock);
1013
1014 VMThread::wait_for_vm_thread_exit();
1015 assert(SafepointSynchronize::is_at_safepoint(), "VM thread should exit at Safepoint");
1016 VMThread::destroy();
1017 }
1018
1019 // Now, all Java threads are gone except daemon threads. Daemon threads
1020 // running Java code or in VM are stopped by the Safepoint. However,
1021 // daemon threads executing native code are still running. But they
1022 // will be stopped at native=>Java/VM barriers. Note that we can't
1023 // simply kill or suspend them, as it is inherently deadlock-prone.
1024
1025 VM_Exit::set_vm_exited();
1026
1027 // Clean up ideal graph printers after the VMThread has started
1028 // the final safepoint which will block all the Compiler threads.
1029 // Note that this Thread has already logically exited so the
1030 // clean_up() function's use of a JavaThreadIteratorWithHandle
1031 // would be a problem except set_vm_exited() has remembered the
1032 // shutdown thread which is granted a policy exception.
1033 #if defined(COMPILER2) && !defined(PRODUCT)
1034 IdealGraphPrinter::clean_up();
1035 #endif
1036
1037 notify_vm_shutdown();
1038
1039 // exit_globals() will delete tty
1040 exit_globals();
1041
1042 // Deleting the shutdown thread here is safe. See comment on
1043 // wait_until_not_protected() above.
1044 delete thread;
1045
1046 #if INCLUDE_JVMCI
1047 if (JVMCICounterSize > 0) {
1048 FREE_C_HEAP_ARRAY(jlong, JavaThread::_jvmci_old_thread_counters);
1049 }
1050 #endif
1051
1052 LogConfiguration::finalize();
1053 }
1054
1055
1056 jboolean Threads::is_supported_jni_version_including_1_1(jint version) {
1057 if (version == JNI_VERSION_1_1) return JNI_TRUE;
1058 return is_supported_jni_version(version);
1059 }
1060
1061
1062 jboolean Threads::is_supported_jni_version(jint version) {
1063 if (version == JNI_VERSION_1_2) return JNI_TRUE;
1064 if (version == JNI_VERSION_1_4) return JNI_TRUE;
1065 if (version == JNI_VERSION_1_6) return JNI_TRUE;
1066 if (version == JNI_VERSION_1_8) return JNI_TRUE;
1067 if (version == JNI_VERSION_9) return JNI_TRUE;
1068 if (version == JNI_VERSION_10) return JNI_TRUE;
1069 if (version == JNI_VERSION_19) return JNI_TRUE;
1070 if (version == JNI_VERSION_20) return JNI_TRUE;
1071 if (version == JNI_VERSION_21) return JNI_TRUE;
1072 return JNI_FALSE;
1073 }
1074
1075 void Threads::add(JavaThread* p, bool force_daemon) {
1076 // The threads lock must be owned at this point
1077 assert(Threads_lock->owned_by_self(), "must have threads lock");
1078
1079 BarrierSet::barrier_set()->on_thread_attach(p);
1080
1081 // Once a JavaThread is added to the Threads list, smr_delete() has
1082 // to be used to delete it. Otherwise we can just delete it directly.
1083 p->set_on_thread_list();
1084
1085 _number_of_threads++;
1086 oop threadObj = p->threadObj();
1087 bool daemon = true;
1088 // Bootstrapping problem: threadObj can be null for initial
1089 // JavaThread (or for threads attached via JNI)
1090 if (!force_daemon &&
1091 (threadObj == nullptr || !java_lang_Thread::is_daemon(threadObj))) {
1092 _number_of_non_daemon_threads++;
1093 daemon = false;
1094 }
1095
1096 ThreadService::add_thread(p, daemon);
1097
1098 // Maintain fast thread list
1099 ThreadsSMRSupport::add_thread(p);
1100
1101 // Increase the ObjectMonitor ceiling for the new thread.
1102 ObjectSynchronizer::inc_in_use_list_ceiling();
1103
1104 // Possible GC point.
1105 Events::log(Thread::current(), "Thread added: " INTPTR_FORMAT, p2i(p));
1106
1107 // Make new thread known to active EscapeBarrier
1108 EscapeBarrier::thread_added(p);
1109 }
1110
1111 void Threads::remove(JavaThread* p, bool is_daemon) {
1112 // Extra scope needed for Thread_lock, so we can check
1113 // that we do not remove thread without safepoint code notice
1114 { MonitorLocker ml(Threads_lock);
1115
1116 if (ThreadIdTable::is_initialized()) {
1117 // This cleanup must be done before the current thread's GC barrier
1118 // is detached since we need to touch the threadObj oop.
1119 jlong tid = SharedRuntime::get_java_tid(p);
1120 ThreadIdTable::remove_thread(tid);
1121 }
1122
1123 // BarrierSet state must be destroyed after the last thread transition
1124 // before the thread terminates. Thread transitions result in calls to
1125 // StackWatermarkSet::on_safepoint(), which performs GC processing,
1126 // requiring the GC state to be alive.
1127 BarrierSet::barrier_set()->on_thread_detach(p);
1128 if (p->is_exiting()) {
1129 // If we got here via JavaThread::exit(), then we remember that the
1130 // thread's GC barrier has been detached. We don't do this when we get
1131 // here from another path, e.g., cleanup_failed_attach_current_thread().
1132 p->set_terminated(JavaThread::_thread_gc_barrier_detached);
1133 }
1134
1135 assert(ThreadsSMRSupport::get_java_thread_list()->includes(p), "p must be present");
1136
1137 // Maintain fast thread list
1138 ThreadsSMRSupport::remove_thread(p);
1139
1140 _number_of_threads--;
1141 if (!is_daemon) {
1142 _number_of_non_daemon_threads--;
1143
1144 // If this is the last non-daemon thread then we need to do
1145 // a notify on the Threads_lock so a thread waiting
1146 // on destroy_vm will wake up. But that thread could be a daemon
1147 // or non-daemon, so we notify for both the 0 and 1 case.
1148 if (number_of_non_daemon_threads() <= 1) {
1149 ml.notify_all();
1150 }
1151 }
1152 ThreadService::remove_thread(p, is_daemon);
1153
1154 // Make sure that safepoint code disregard this thread. This is needed since
1155 // the thread might mess around with locks after this point. This can cause it
1156 // to do callbacks into the safepoint code. However, the safepoint code is not aware
1157 // of this thread since it is removed from the queue.
1158 p->set_terminated(JavaThread::_thread_terminated);
1159
1160 // Notify threads waiting in EscapeBarriers
1161 EscapeBarrier::thread_removed(p);
1162 } // unlock Threads_lock
1163
1164 // Reduce the ObjectMonitor ceiling for the exiting thread.
1165 ObjectSynchronizer::dec_in_use_list_ceiling();
1166
1167 // Since Events::log uses a lock, we grab it outside the Threads_lock
1168 Events::log(Thread::current(), "Thread exited: " INTPTR_FORMAT, p2i(p));
1169 }
1170
1171 // Operations on the Threads list for GC. These are not explicitly locked,
1172 // but the garbage collector must provide a safe context for them to run.
1173 // In particular, these things should never be called when the Threads_lock
1174 // is held by some other thread. (Note: the Safepoint abstraction also
1175 // uses the Threads_lock to guarantee this property. It also makes sure that
1176 // all threads gets blocked when exiting or starting).
1177
1178 void Threads::oops_do(OopClosure* f, NMethodClosure* cf) {
1179 ALL_JAVA_THREADS(p) {
1180 p->oops_do(f, cf);
1181 }
1182 VMThread::vm_thread()->oops_do(f, cf);
1183 }
1184
1185 void Threads::change_thread_claim_token() {
1186 if (++_thread_claim_token == 0) {
1187 // On overflow of the token counter, there is a risk of future
1188 // collisions between a new global token value and a stale token
1189 // for a thread, because not all iterations visit all threads.
1190 // (Though it's pretty much a theoretical concern for non-trivial
1191 // token counter sizes.) To deal with the possibility, reset all
1192 // the thread tokens to zero on global token overflow.
1193 struct ResetClaims : public ThreadClosure {
1194 virtual void do_thread(Thread* t) {
1195 t->claim_threads_do(false, 0);
1196 }
1197 } reset_claims;
1198 Threads::threads_do(&reset_claims);
1199 // On overflow, update the global token to non-zero, to
1200 // avoid the special "never claimed" initial thread value.
1201 _thread_claim_token = 1;
1202 }
1203 }
1204
1205 #ifdef ASSERT
1206 static void assert_thread_claimed(const char* kind, Thread* t, uintx expected) {
1207 const uintx token = t->threads_do_token();
1208 assert(token == expected,
1209 "%s " PTR_FORMAT " has incorrect value " UINTX_FORMAT " != "
1210 UINTX_FORMAT, kind, p2i(t), token, expected);
1211 }
1212
1213 void Threads::assert_all_threads_claimed() {
1214 ALL_JAVA_THREADS(p) {
1215 assert_thread_claimed("JavaThread", p, _thread_claim_token);
1216 }
1217
1218 struct NJTClaimedVerifierClosure : public ThreadClosure {
1219 uintx _thread_claim_token;
1220
1221 NJTClaimedVerifierClosure(uintx thread_claim_token) : ThreadClosure(), _thread_claim_token(thread_claim_token) { }
1222
1223 virtual void do_thread(Thread* thread) override {
1224 assert_thread_claimed("Non-JavaThread", VMThread::vm_thread(), _thread_claim_token);
1225 }
1226 } tc(_thread_claim_token);
1227
1228 non_java_threads_do(&tc);
1229 }
1230 #endif // ASSERT
1231
1232 class ParallelOopsDoThreadClosure : public ThreadClosure {
1233 private:
1234 OopClosure* _f;
1235 NMethodClosure* _cf;
1236 public:
1237 ParallelOopsDoThreadClosure(OopClosure* f, NMethodClosure* cf) : _f(f), _cf(cf) {}
1238 void do_thread(Thread* t) {
1239 t->oops_do(_f, _cf);
1240 }
1241 };
1242
1243 void Threads::possibly_parallel_oops_do(bool is_par, OopClosure* f, NMethodClosure* cf) {
1244 ParallelOopsDoThreadClosure tc(f, cf);
1245 possibly_parallel_threads_do(is_par, &tc);
1246 }
1247
1248 void Threads::metadata_do(MetadataClosure* f) {
1249 ALL_JAVA_THREADS(p) {
1250 p->metadata_do(f);
1251 }
1252 }
1253
1254 class ThreadHandlesClosure : public ThreadClosure {
1255 void (*_f)(Metadata*);
1256 public:
1257 ThreadHandlesClosure(void f(Metadata*)) : _f(f) {}
1258 virtual void do_thread(Thread* thread) {
1259 thread->metadata_handles_do(_f);
1260 }
1261 };
1262
1263 void Threads::metadata_handles_do(void f(Metadata*)) {
1264 // Only walk the Handles in Thread.
1265 ThreadHandlesClosure handles_closure(f);
1266 threads_do(&handles_closure);
1267 }
1268
1269 #if INCLUDE_JVMTI
1270 // Get Java threads that are waiting to enter or re-enter the specified monitor.
1271 // Java threads that are executing mounted virtual threads are not included.
1272 GrowableArray<JavaThread*>* Threads::get_pending_threads(ThreadsList * t_list,
1273 int count,
1274 address monitor) {
1275 assert(Thread::current()->is_VM_thread(), "Must be the VM thread");
1276 GrowableArray<JavaThread*>* result = new GrowableArray<JavaThread*>(count);
1277
1278 int i = 0;
1279 for (JavaThread* p : *t_list) {
1280 if (!p->can_call_java()) continue;
1281
1282 oop thread_oop = JvmtiEnvBase::get_vthread_or_thread_oop(p);
1283 if (thread_oop->is_a(vmClasses::BaseVirtualThread_klass())) {
1284 continue;
1285 }
1286 // The first stage of async deflation does not affect any field
1287 // used by this comparison so the ObjectMonitor* is usable here.
1288 address pending = (address)p->current_pending_monitor();
1289 address waiting = (address)p->current_waiting_monitor();
1290 // do not include virtual threads to the list
1291 jint state = JvmtiEnvBase::get_thread_state(thread_oop, p);
1292 if (pending == monitor || (waiting == monitor &&
1293 (state & JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER))
1294 ) { // found a match
1295 if (i < count) result->append(p); // save the first count matches
1296 i++;
1297 }
1298 }
1299
1300 return result;
1301 }
1302 #endif // INCLUDE_JVMTI
1303
1304 JavaThread *Threads::owning_thread_from_monitor_owner(ThreadsList * t_list,
1305 address owner) {
1306 assert(LockingMode != LM_LIGHTWEIGHT, "Not with new lightweight locking");
1307 // null owner means not locked so we can skip the search
1308 if (owner == nullptr) return nullptr;
1309
1310 for (JavaThread* p : *t_list) {
1311 // first, see if owner is the address of a Java thread
1312 if (owner == (address)p) return p;
1313 }
1314
1315 // Cannot assert on lack of success here since this function may be
1316 // used by code that is trying to report useful problem information
1317 // like deadlock detection.
1318 if (LockingMode == LM_MONITOR) return nullptr;
1319
1320 // If we didn't find a matching Java thread and we didn't force use of
1321 // heavyweight monitors, then the owner is the stack address of the
1322 // Lock Word in the owning Java thread's stack.
1323 //
1324 JavaThread* the_owner = nullptr;
1325 for (JavaThread* q : *t_list) {
1326 if (q->is_lock_owned(owner)) {
1327 the_owner = q;
1328 break;
1329 }
1330 }
1331
1332 // cannot assert on lack of success here; see above comment
1333 return the_owner;
1334 }
1335
1336 JavaThread* Threads::owning_thread_from_object(ThreadsList * t_list, oop obj) {
1337 assert(LockingMode == LM_LIGHTWEIGHT, "Only with new lightweight locking");
1338 for (JavaThread* q : *t_list) {
1339 // Need to start processing before accessing oops in the thread.
1340 StackWatermark* watermark = StackWatermarkSet::get(q, StackWatermarkKind::gc);
1341 if (watermark != nullptr) {
1342 watermark->start_processing();
1343 }
1344
1345 if (q->lock_stack().contains(obj)) {
1346 return q;
1347 }
1348 }
1349 return nullptr;
1350 }
1351
1352 JavaThread* Threads::owning_thread_from_monitor(ThreadsList* t_list, ObjectMonitor* monitor) {
1353 if (LockingMode == LM_LIGHTWEIGHT) {
1354 if (monitor->is_owner_anonymous()) {
1355 return owning_thread_from_object(t_list, monitor->object());
1356 } else {
1357 Thread* owner = reinterpret_cast<Thread*>(monitor->owner());
1358 assert(owner == nullptr || owner->is_Java_thread(), "only JavaThreads own monitors");
1359 return reinterpret_cast<JavaThread*>(owner);
1360 }
1361 } else {
1362 address owner = (address)monitor->owner();
1363 return owning_thread_from_monitor_owner(t_list, owner);
1364 }
1365 }
1366
1367 class PrintOnClosure : public ThreadClosure {
1368 private:
1369 outputStream* _st;
1370
1371 public:
1372 PrintOnClosure(outputStream* st) :
1373 _st(st) {}
1374
1375 virtual void do_thread(Thread* thread) {
1376 if (thread != nullptr) {
1377 thread->print_on(_st);
1378 _st->cr();
1379 }
1380 }
1381 };
1382
1383 // Threads::print_on() is called at safepoint by VM_PrintThreads operation.
1384 void Threads::print_on(outputStream* st, bool print_stacks,
1385 bool internal_format, bool print_concurrent_locks,
1386 bool print_extended_info) {
1387 char buf[32];
1388 st->print_raw_cr(os::local_time_string(buf, sizeof(buf)));
1389
1390 st->print_cr("Full thread dump %s (%s %s):",
1391 VM_Version::vm_name(),
1392 VM_Version::vm_release(),
1393 VM_Version::vm_info_string());
1394 st->cr();
1395
1396 #if INCLUDE_SERVICES
1397 // Dump concurrent locks
1398 ConcurrentLocksDump concurrent_locks;
1399 if (print_concurrent_locks) {
1400 concurrent_locks.dump_at_safepoint();
1401 }
1402 #endif // INCLUDE_SERVICES
1403
1404 ThreadsSMRSupport::print_info_on(st);
1405 st->cr();
1406
1407 ALL_JAVA_THREADS(p) {
1408 ResourceMark rm;
1409 p->print_on(st, print_extended_info);
1410 if (print_stacks) {
1411 if (internal_format) {
1412 p->trace_stack();
1413 } else {
1414 p->print_stack_on(st);
1415 const oop thread_oop = p->threadObj();
1416 if (thread_oop != nullptr) {
1417 if (p->is_vthread_mounted()) {
1418 const oop vt = p->vthread();
1419 assert(vt != nullptr, "vthread should not be null when vthread is mounted");
1420 // JavaThread._vthread can refer to the carrier thread. Print only if _vthread refers to a virtual thread.
1421 if (vt != thread_oop) {
1422 st->print_cr(" Mounted virtual thread #" INT64_FORMAT, (int64_t)java_lang_Thread::thread_id(vt));
1423 p->print_vthread_stack_on(st);
1424 }
1425 }
1426 }
1427 }
1428 }
1429 st->cr();
1430 #if INCLUDE_SERVICES
1431 if (print_concurrent_locks) {
1432 concurrent_locks.print_locks_on(p, st);
1433 }
1434 #endif // INCLUDE_SERVICES
1435 }
1436
1437 PrintOnClosure cl(st);
1438 non_java_threads_do(&cl);
1439
1440 st->flush();
1441 }
1442
1443 void Threads::print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
1444 int buflen, bool* found_current) {
1445 if (this_thread != nullptr) {
1446 bool is_current = (current == this_thread);
1447 *found_current = *found_current || is_current;
1448 st->print("%s", is_current ? "=>" : " ");
1449
1450 st->print(PTR_FORMAT, p2i(this_thread));
1451 st->print(" ");
1452 this_thread->print_on_error(st, buf, buflen);
1453 st->cr();
1454 }
1455 }
1456
1457 class PrintOnErrorClosure : public ThreadClosure {
1458 outputStream* _st;
1459 Thread* _current;
1460 char* _buf;
1461 int _buflen;
1462 bool* _found_current;
1463 unsigned _num_printed;
1464 public:
1465 PrintOnErrorClosure(outputStream* st, Thread* current, char* buf,
1466 int buflen, bool* found_current) :
1467 _st(st), _current(current), _buf(buf), _buflen(buflen), _found_current(found_current),
1468 _num_printed(0) {}
1469
1470 virtual void do_thread(Thread* thread) {
1471 _num_printed++;
1472 Threads::print_on_error(thread, _st, _current, _buf, _buflen, _found_current);
1473 }
1474
1475 unsigned num_printed() const { return _num_printed; }
1476 };
1477
1478 // Threads::print_on_error() is called by fatal error handler. It's possible
1479 // that VM is not at safepoint and/or current thread is inside signal handler.
1480 // Don't print stack trace, as the stack may not be walkable. Don't allocate
1481 // memory (even in resource area), it might deadlock the error handler.
1482 void Threads::print_on_error(outputStream* st, Thread* current, char* buf,
1483 int buflen) {
1484 ThreadsSMRSupport::print_info_on(st);
1485 st->cr();
1486
1487 bool found_current = false;
1488 st->print_cr("Java Threads: ( => current thread )");
1489 unsigned num_java = 0;
1490 ALL_JAVA_THREADS(thread) {
1491 print_on_error(thread, st, current, buf, buflen, &found_current);
1492 num_java++;
1493 }
1494 st->print_cr("Total: %u", num_java);
1495 st->cr();
1496
1497 st->print_cr("Other Threads:");
1498 unsigned num_other = ((VMThread::vm_thread() != nullptr) ? 1 : 0) +
1499 ((WatcherThread::watcher_thread() != nullptr) ? 1 : 0) +
1500 ((AsyncLogWriter::instance() != nullptr) ? 1 : 0);
1501 print_on_error(VMThread::vm_thread(), st, current, buf, buflen, &found_current);
1502 print_on_error(WatcherThread::watcher_thread(), st, current, buf, buflen, &found_current);
1503 print_on_error(AsyncLogWriter::instance(), st, current, buf, buflen, &found_current);
1504
1505 if (Universe::heap() != nullptr) {
1506 PrintOnErrorClosure print_closure(st, current, buf, buflen, &found_current);
1507 Universe::heap()->gc_threads_do(&print_closure);
1508 num_other += print_closure.num_printed();
1509 }
1510
1511 if (!found_current) {
1512 st->cr();
1513 st->print("=>" PTR_FORMAT " (exited) ", p2i(current));
1514 current->print_on_error(st, buf, buflen);
1515 num_other++;
1516 st->cr();
1517 }
1518 st->print_cr("Total: %u", num_other);
1519 st->cr();
1520
1521 st->print_cr("Threads with active compile tasks:");
1522 unsigned num = print_threads_compiling(st, buf, buflen);
1523 st->print_cr("Total: %u", num);
1524 }
1525
1526 unsigned Threads::print_threads_compiling(outputStream* st, char* buf, int buflen, bool short_form) {
1527 unsigned num = 0;
1528 ALL_JAVA_THREADS(thread) {
1529 if (thread->is_Compiler_thread()) {
1530 CompilerThread* ct = (CompilerThread*) thread;
1531
1532 // Keep task in local variable for null check.
1533 // ct->_task might be set to null by concurring compiler thread
1534 // because it completed the compilation. The task is never freed,
1535 // though, just returned to a free list.
1536 CompileTask* task = ct->task();
1537 if (task != nullptr) {
1538 thread->print_name_on_error(st, buf, buflen);
1539 st->print(" ");
1540 task->print(st, nullptr, short_form, true);
1541 num++;
1542 }
1543 }
1544 }
1545 return num;
1546 }
1547
1548 void Threads::verify() {
1549 ALL_JAVA_THREADS(p) {
1550 p->verify();
1551 }
1552 VMThread* thread = VMThread::vm_thread();
1553 if (thread != nullptr) thread->verify();
1554 }