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/aotLinkedClassBulkLoader.hpp"
28 #include "cds/cds_globals.hpp"
29 #include "cds/cdsConfig.hpp"
30 #include "cds/heapShared.hpp"
31 #include "cds/metaspaceShared.hpp"
32 #include "cds/methodProfiler.hpp"
33 #include "classfile/classLoader.hpp"
34 #include "classfile/javaClasses.hpp"
35 #include "classfile/javaThreadStatus.hpp"
36 #include "classfile/symbolTable.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 "oops/symbol.hpp"
70 #include "prims/jvm_misc.hpp"
71 #include "prims/jvmtiAgentList.hpp"
72 #include "prims/jvmtiEnvBase.hpp"
73 #include "runtime/arguments.hpp"
74 #include "runtime/fieldDescriptor.inline.hpp"
75 #include "runtime/flags/jvmFlagLimit.hpp"
76 #include "runtime/globals.hpp"
77 #include "runtime/globals_extension.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 COMPILER1
120 #include "c1/c1_Runtime1.hpp"
121 #endif
122 #ifdef COMPILER2
123 #include "opto/idealGraphPrinter.hpp"
124 #include "opto/runtime.hpp"
125 #endif
126 #if INCLUDE_JFR
127 #include "jfr/jfr.hpp"
128 #endif
129
130 // Initialization after module runtime initialization
131 void universe_post_module_init(); // must happen after call_initPhase2
132
133
134 static void initialize_class(Symbol* class_name, TRAPS) {
135 Klass* klass = SystemDictionary::resolve_or_fail(class_name, true, CHECK);
136 InstanceKlass::cast(klass)->initialize(CHECK);
137 }
138
139
140 // Creates the initial ThreadGroup
141 static Handle create_initial_thread_group(TRAPS) {
142 Handle system_instance = JavaCalls::construct_new_instance(
143 vmClasses::ThreadGroup_klass(),
144 vmSymbols::void_method_signature(),
145 CHECK_NH);
146 Universe::set_system_thread_group(system_instance());
147
148 Handle string = java_lang_String::create_from_str("main", CHECK_NH);
149 Handle main_instance = JavaCalls::construct_new_instance(
150 vmClasses::ThreadGroup_klass(),
151 vmSymbols::threadgroup_string_void_signature(),
152 system_instance,
153 string,
154 CHECK_NH);
155 return main_instance;
156 }
157
158 // Creates the initial Thread, and sets it to running.
159 static void create_initial_thread(Handle thread_group, JavaThread* thread,
160 TRAPS) {
161 InstanceKlass* ik = vmClasses::Thread_klass();
162 assert(ik->is_initialized(), "must be");
163 instanceHandle thread_oop = ik->allocate_instance_handle(CHECK);
164
165 // Cannot use JavaCalls::construct_new_instance because the java.lang.Thread
166 // constructor calls Thread.current(), which must be set here for the
167 // initial thread.
168 java_lang_Thread::set_thread(thread_oop(), thread);
169 thread->set_threadOopHandles(thread_oop());
170
171 Handle string = java_lang_String::create_from_str("main", CHECK);
172
173 JavaValue result(T_VOID);
174 JavaCalls::call_special(&result, thread_oop,
175 ik,
176 vmSymbols::object_initializer_name(),
177 vmSymbols::threadgroup_string_void_signature(),
178 thread_group,
179 string,
180 CHECK);
181
182 DEBUG_ONLY(int64_t main_thread_tid = java_lang_Thread::thread_id(thread_oop());)
183 assert(main_thread_tid == ThreadIdentifier::initial(), "");
184 assert(main_thread_tid == thread->lock_id(), "");
185 JFR_ONLY(assert(JFR_JVM_THREAD_ID(thread) == static_cast<traceid>(main_thread_tid), "initial tid mismatch");)
186
187 // Set thread status to running since main thread has
188 // been started and running.
189 java_lang_Thread::set_thread_status(thread_oop(),
190 JavaThreadStatus::RUNNABLE);
191 }
192
193 // Extract version and vendor specific information from
194 // java.lang.VersionProps fields.
195 // Returned char* is allocated in the thread's resource area
196 // so must be copied for permanency.
197 static const char* get_java_version_info(InstanceKlass* ik,
198 Symbol* field_name) {
199 fieldDescriptor fd;
200 bool found = ik != nullptr &&
201 ik->find_local_field(field_name,
202 vmSymbols::string_signature(), &fd);
203 if (found) {
204 oop name_oop = ik->java_mirror()->obj_field(fd.offset());
205 if (name_oop == nullptr) {
206 return nullptr;
207 }
208 const char* name = java_lang_String::as_utf8_string(name_oop);
209 return name;
210 } else {
211 return nullptr;
212 }
213 }
214
215 // ======= Threads ========
216
217 // The Threads class links together all active threads, and provides
218 // operations over all threads. It is protected by the Threads_lock,
219 // which is also used in other global contexts like safepointing.
220 // ThreadsListHandles are used to safely perform operations on one
221 // or more threads without the risk of the thread exiting during the
222 // operation.
223 //
224 // Note: The Threads_lock is currently more widely used than we
225 // would like. We are actively migrating Threads_lock uses to other
226 // mechanisms in order to reduce Threads_lock contention.
227
228 int Threads::_number_of_threads = 0;
229 int Threads::_number_of_non_daemon_threads = 0;
230 int Threads::_return_code = 0;
231 uintx Threads::_thread_claim_token = 1; // Never zero.
232
233 #ifdef ASSERT
234 bool Threads::_vm_complete = false;
235 #endif
236
237 // General purpose hook into Java code, run once when the VM is initialized.
238 // The Java library method itself may be changed independently from the VM.
239 static void call_postVMInitHook(TRAPS) {
240 Klass* klass = SystemDictionary::resolve_or_null(vmSymbols::jdk_internal_vm_PostVMInitHook(), THREAD);
241 if (klass != nullptr) {
242 JavaValue result(T_VOID);
243 JavaCalls::call_static(&result, klass, vmSymbols::run_method_name(),
244 vmSymbols::void_method_signature(),
245 CHECK);
246 }
247 }
248
249 // All NonJavaThreads (i.e., every non-JavaThread in the system).
250 void Threads::non_java_threads_do(ThreadClosure* tc) {
251 NoSafepointVerifier nsv;
252 for (NonJavaThread::Iterator njti; !njti.end(); njti.step()) {
253 tc->do_thread(njti.current());
254 }
255 }
256
257 // All JavaThreads
258 #define ALL_JAVA_THREADS(X) \
259 for (JavaThread* X : *ThreadsSMRSupport::get_java_thread_list())
260
261 // All JavaThreads
262 void Threads::java_threads_do(ThreadClosure* tc) {
263 assert_locked_or_safepoint(Threads_lock);
264 // ALL_JAVA_THREADS iterates through all JavaThreads.
265 ALL_JAVA_THREADS(p) {
266 tc->do_thread(p);
267 }
268 }
269
270 // All JavaThreads + all non-JavaThreads (i.e., every thread in the system).
271 void Threads::threads_do(ThreadClosure* tc) {
272 assert_locked_or_safepoint(Threads_lock);
273 java_threads_do(tc);
274 non_java_threads_do(tc);
275 }
276
277 void Threads::possibly_parallel_threads_do(bool is_par, ThreadClosure* tc) {
278 assert_at_safepoint();
279
280 uintx claim_token = Threads::thread_claim_token();
281 ALL_JAVA_THREADS(p) {
282 if (p->claim_threads_do(is_par, claim_token)) {
283 tc->do_thread(p);
284 }
285 }
286 for (NonJavaThread::Iterator njti; !njti.end(); njti.step()) {
287 Thread* current = njti.current();
288 if (current->claim_threads_do(is_par, claim_token)) {
289 tc->do_thread(current);
290 }
291 }
292 }
293
294 // The system initialization in the library has three phases.
295 //
296 // Phase 1: java.lang.System class initialization
297 // java.lang.System is a primordial class loaded and initialized
298 // by the VM early during startup. java.lang.System.<clinit>
299 // only does registerNatives and keeps the rest of the class
300 // initialization work later until thread initialization completes.
301 //
302 // System.initPhase1 initializes the system properties, the static
303 // fields in, out, and err. Set up java signal handlers, OS-specific
304 // system settings, and thread group of the main thread.
305 static void call_initPhase1(TRAPS) {
306 Klass* klass = vmClasses::System_klass();
307 JavaValue result(T_VOID);
308 JavaCalls::call_static(&result, klass, vmSymbols::initPhase1_name(),
309 vmSymbols::void_method_signature(), CHECK);
310 }
311
312 // Phase 2. Module system initialization
313 // This will initialize the module system. Only java.base classes
314 // can be loaded until phase 2 completes.
315 //
316 // Call System.initPhase2 after the compiler initialization and jsr292
317 // classes get initialized because module initialization runs a lot of java
318 // code, that for performance reasons, should be compiled. Also, this will
319 // enable the startup code to use lambda and other language features in this
320 // phase and onward.
321 //
322 // After phase 2, The VM will begin search classes from -Xbootclasspath/a.
323 static void call_initPhase2(TRAPS) {
324 TraceTime timer("Initialize module system", TRACETIME_LOG(Info, startuptime));
325
326 Klass* klass = vmClasses::System_klass();
327
328 JavaValue result(T_INT);
329 JavaCallArguments args;
330 args.push_int(DisplayVMOutputToStderr);
331 args.push_int(log_is_enabled(Debug, init)); // print stack trace if exception thrown
332 JavaCalls::call_static(&result, klass, vmSymbols::initPhase2_name(),
333 vmSymbols::boolean_boolean_int_signature(), &args, CHECK);
334 if (result.get_jint() != JNI_OK) {
335 vm_exit_during_initialization(); // no message or exception
336 }
337
338 universe_post_module_init();
339
340 #if 0
341 if (CDSConfig::is_using_aot_linked_classes()) {
342 AOTLinkedClassBulkLoader::load_non_javabase_boot_classes(THREAD);
343 if (CDSConfig::is_using_full_module_graph()) {
344 assert(SystemDictionary::java_platform_loader() != nullptr, "must be");
345 assert(SystemDictionary::java_system_loader() != nullptr, "must be");
346 AOTLinkedClassBulkLoader::load_platform_classes(THREAD);
347 AOTLinkedClassBulkLoader::load_app_classes(THREAD);
348 } else {
349 // Special case -- we assume that the final archive has the same module graph
350 // as the training run.
351 // AOTLinkedClassBulkLoader will be called for the platform/system loaders
352 // inside SystemDictionary::compute_java_loaders().
353 assert(CDSConfig::is_dumping_final_static_archive(), "must be");
354 assert(SystemDictionary::java_platform_loader() == nullptr, "must be");
355 assert(SystemDictionary::java_system_loader() == nullptr, "must be");
356 }
357 }
358
359 #ifndef PRODUCT
360 HeapShared::initialize_test_class_from_archive(THREAD);
361 #endif
362 #endif
363 }
364
365 // Phase 3. final setup - set security manager, system class loader and TCCL
366 //
367 // This will instantiate and set the security manager, set the system class
368 // loader as well as the thread context class loader. The security manager
369 // and system class loader may be a custom class loaded from -Xbootclasspath/a,
370 // other modules or the application's classpath.
371 static void call_initPhase3(TRAPS) {
372 Klass* klass = vmClasses::System_klass();
373 JavaValue result(T_VOID);
374 JavaCalls::call_static(&result, klass, vmSymbols::initPhase3_name(),
375 vmSymbols::void_method_signature(), CHECK);
376 }
377
378 void Threads::initialize_java_lang_classes(JavaThread* main_thread, TRAPS) {
379 TraceTime timer("Initialize java.lang classes", TRACETIME_LOG(Info, startuptime));
380
381 initialize_class(vmSymbols::java_lang_String(), CHECK);
382
383 // Inject CompactStrings value after the static initializers for String ran.
384 java_lang_String::set_compact_strings(CompactStrings);
385
386 // Initialize java_lang.System (needed before creating the thread)
387 initialize_class(vmSymbols::java_lang_System(), CHECK);
388 // The VM creates & returns objects of this class. Make sure it's initialized.
389 initialize_class(vmSymbols::java_lang_Class(), CHECK);
390
391 initialize_class(vmSymbols::java_lang_ThreadGroup(), CHECK);
392 Handle thread_group = create_initial_thread_group(CHECK);
393 Universe::set_main_thread_group(thread_group());
394 initialize_class(vmSymbols::java_lang_Thread(), CHECK);
395 create_initial_thread(thread_group, main_thread, CHECK);
396
397 HeapShared::init_box_classes(CHECK);
398
399 // The VM creates objects of this class.
400 initialize_class(vmSymbols::java_lang_Module(), CHECK);
401
402 #ifdef ASSERT
403 InstanceKlass *k = vmClasses::UnsafeConstants_klass();
404 assert(k->is_not_initialized(), "UnsafeConstants should not already be initialized");
405 #endif
406
407 // initialize the hardware-specific constants needed by Unsafe
408 initialize_class(vmSymbols::jdk_internal_misc_UnsafeConstants(), CHECK);
409 jdk_internal_misc_UnsafeConstants::set_unsafe_constants();
410
411 // The VM preresolves methods to these classes. Make sure that they get initialized
412 initialize_class(vmSymbols::java_lang_reflect_Method(), CHECK);
413 initialize_class(vmSymbols::java_lang_ref_Finalizer(), CHECK);
414
415 // Phase 1 of the system initialization in the library, java.lang.System class initialization
416 call_initPhase1(CHECK);
417
418 // Get the Java runtime name, version, and vendor info after java.lang.System is initialized.
419 // Some values are actually configure-time constants but some can be set via the jlink tool and
420 // so must be read dynamically. We treat them all the same.
421 InstanceKlass* ik = SystemDictionary::find_instance_klass(THREAD, vmSymbols::java_lang_VersionProps(),
422 Handle(), Handle());
423 {
424 ResourceMark rm(main_thread);
425 JDK_Version::set_java_version(get_java_version_info(ik, vmSymbols::java_version_name()));
426
427 JDK_Version::set_runtime_name(get_java_version_info(ik, vmSymbols::java_runtime_name_name()));
428
429 JDK_Version::set_runtime_version(get_java_version_info(ik, vmSymbols::java_runtime_version_name()));
430
431 JDK_Version::set_runtime_vendor_version(get_java_version_info(ik, vmSymbols::java_runtime_vendor_version_name()));
432
433 JDK_Version::set_runtime_vendor_vm_bug_url(get_java_version_info(ik, vmSymbols::java_runtime_vendor_vm_bug_url_name()));
434 }
435
436 // an instance of OutOfMemory exception has been allocated earlier
437 initialize_class(vmSymbols::java_lang_OutOfMemoryError(), CHECK);
438 initialize_class(vmSymbols::java_lang_NullPointerException(), CHECK);
439 initialize_class(vmSymbols::java_lang_ClassCastException(), CHECK);
440 initialize_class(vmSymbols::java_lang_ArrayStoreException(), CHECK);
441 initialize_class(vmSymbols::java_lang_ArithmeticException(), CHECK);
442 initialize_class(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), CHECK);
443 initialize_class(vmSymbols::java_lang_StackOverflowError(), CHECK);
444 initialize_class(vmSymbols::java_lang_IllegalMonitorStateException(), CHECK);
445 initialize_class(vmSymbols::java_lang_IllegalArgumentException(), CHECK);
446 initialize_class(vmSymbols::java_lang_InternalError(), CHECK);
447 }
448
449 bool Threads::initialize_compilation(TRAPS) {
450 // initialize compiler(s)
451 bool force_JVMCI_initialization = false;
452
453 #if defined(COMPILER1) || COMPILER2_OR_JVMCI
454 bool init_compilation = true;
455 #if INCLUDE_JVMCI
456 if (EnableJVMCI) {
457 // Initialize JVMCI eagerly when it is explicitly requested.
458 // Or when JVMCILibDumpJNIConfig or JVMCIPrintProperties is enabled.
459 force_JVMCI_initialization = EagerJVMCI || JVMCIPrintProperties || JVMCILibDumpJNIConfig;
460 if (!force_JVMCI_initialization && UseJVMCICompiler && !UseJVMCINativeLibrary && (!UseInterpreter || !BackgroundCompilation)) {
461 // Force initialization of jarjvmci otherwise requests for blocking
462 // compilations will not actually block until jarjvmci is initialized.
463 force_JVMCI_initialization = true;
464 }
465 if (JVMCIPrintProperties || JVMCILibDumpJNIConfig) {
466 // Both JVMCILibDumpJNIConfig and JVMCIPrintProperties exit the VM
467 // so compilation should be disabled. This prevents dumping or
468 // printing from happening more than once.
469 init_compilation = false;
470 }
471 }
472 #endif
473 if (init_compilation) {
474 CompileBroker::compilation_init(CHECK_false);
475 }
476 #endif
477
478 return force_JVMCI_initialization;
479 }
480
481 void Threads::initialize_jsr292_core_classes(TRAPS) {
482 TraceTime timer("Initialize java.lang.invoke classes", TRACETIME_LOG(Info, startuptime));
483
484 initialize_class(vmSymbols::java_lang_invoke_MethodHandle(), CHECK);
485 initialize_class(vmSymbols::java_lang_invoke_ResolvedMethodName(), CHECK);
486 initialize_class(vmSymbols::java_lang_invoke_MemberName(), CHECK);
487 initialize_class(vmSymbols::java_lang_invoke_MethodHandleNatives(), CHECK);
488
489 if (UseSharedSpaces) {
490 HeapShared::initialize_java_lang_invoke(CHECK);
491 }
492 }
493
494 jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) {
495 extern void JDK_Version_init();
496
497 // Preinitialize version info.
498 VM_Version::early_initialize();
499
500 // Check version
501 if (!is_supported_jni_version(args->version)) return JNI_EVERSION;
502
503 // Initialize library-based TLS
504 ThreadLocalStorage::init();
505
506 // Initialize the output stream module
507 ostream_init();
508
509 // Process java launcher properties.
510 Arguments::process_sun_java_launcher_properties(args);
511
512 // Initialize the os module
513 os::init();
514
515 MACOS_AARCH64_ONLY(os::current_thread_enable_wx(WXWrite));
516
517 // Record VM creation timing statistics
518 TraceVmCreationTime create_vm_timer;
519 create_vm_timer.start();
520
521 // Initialize system properties.
522 Arguments::init_system_properties();
523
524 // So that JDK version can be used as a discriminator when parsing arguments
525 JDK_Version_init();
526
527 // Update/Initialize System properties after JDK version number is known
528 Arguments::init_version_specific_system_properties();
529
530 // Make sure to initialize log configuration *before* parsing arguments
531 LogConfiguration::initialize(create_vm_timer.begin_time());
532
533 // Parse arguments
534 // Note: this internally calls os::init_container_support()
535 jint parse_result = Arguments::parse(args);
536 if (parse_result != JNI_OK) return parse_result;
537
538 // Initialize NMT right after argument parsing to keep the pre-NMT-init window small.
539 MemTracker::initialize();
540
541 os::init_before_ergo();
542
543 jint ergo_result = Arguments::apply_ergo();
544 if (ergo_result != JNI_OK) return ergo_result;
545
546 // Final check of all ranges after ergonomics which may change values.
547 if (!JVMFlagLimit::check_all_ranges()) {
548 return JNI_EINVAL;
549 }
550
551 // Final check of all 'AfterErgo' constraints after ergonomics which may change values.
552 bool constraint_result = JVMFlagLimit::check_all_constraints(JVMFlagConstraintPhase::AfterErgo);
553 if (!constraint_result) {
554 return JNI_EINVAL;
555 }
556
557 if (PauseAtStartup) {
558 os::pause();
559 }
560
561 HOTSPOT_VM_INIT_BEGIN();
562
563 // Timing (must come after argument parsing)
564 TraceTime timer("Create VM", TRACETIME_LOG(Info, startuptime));
565
566 // Initialize the os module after parsing the args
567 jint os_init_2_result = os::init_2();
568 if (os_init_2_result != JNI_OK) return os_init_2_result;
569
570 #ifdef CAN_SHOW_REGISTERS_ON_ASSERT
571 // Initialize assert poison page mechanism.
572 if (ShowRegistersOnAssert) {
573 initialize_assert_poison();
574 }
575 #endif // CAN_SHOW_REGISTERS_ON_ASSERT
576
577 SafepointMechanism::initialize();
578
579 jint adjust_after_os_result = Arguments::adjust_after_os();
580 if (adjust_after_os_result != JNI_OK) return adjust_after_os_result;
581
582 // Initialize output stream logging
583 ostream_init_log();
584
585 // Launch -agentlib/-agentpath and converted -Xrun agents
586 JvmtiAgentList::load_agents();
587
588 // Initialize Threads state
589 _number_of_threads = 0;
590 _number_of_non_daemon_threads = 0;
591
592 // Initialize global data structures and create system classes in heap
593 vm_init_globals();
594
595 #if INCLUDE_JVMCI
596 if (JVMCICounterSize > 0) {
597 JavaThread::_jvmci_old_thread_counters = NEW_C_HEAP_ARRAY(jlong, JVMCICounterSize, mtJVMCI);
598 memset(JavaThread::_jvmci_old_thread_counters, 0, sizeof(jlong) * JVMCICounterSize);
599 } else {
600 JavaThread::_jvmci_old_thread_counters = nullptr;
601 }
602 #endif // INCLUDE_JVMCI
603
604 // Initialize OopStorage for threadObj
605 JavaThread::_thread_oop_storage = OopStorageSet::create_strong("Thread OopStorage", mtThread);
606
607 // Attach the main thread to this os thread
608 JavaThread* main_thread = new JavaThread();
609 main_thread->set_thread_state(_thread_in_vm);
610 main_thread->initialize_thread_current();
611 // must do this before set_active_handles
612 main_thread->record_stack_base_and_size();
613 main_thread->register_thread_stack_with_NMT();
614 main_thread->set_active_handles(JNIHandleBlock::allocate_block());
615 MACOS_AARCH64_ONLY(main_thread->init_wx());
616
617 MutexLockerImpl::init_counters(); // depends on mutex_init(), perfMemory_init(), and Thread::initialize_thread_current().
618
619 // Set the lock_id now since we will run Java code before the Thread instance
620 // is even created. The same value will be assigned to the Thread instance on init.
621 main_thread->set_lock_id(ThreadIdentifier::next());
622
623 if (!Thread::set_as_starting_thread(main_thread)) {
624 vm_shutdown_during_initialization(
625 "Failed necessary internal allocation. Out of swap space");
626 main_thread->smr_delete();
627 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
628 return JNI_ENOMEM;
629 }
630
631 JFR_ONLY(Jfr::initialize_main_thread(main_thread);)
632
633 // Enable guard page *after* os::create_main_thread(), otherwise it would
634 // crash Linux VM, see notes in os_linux.cpp.
635 main_thread->stack_overflow_state()->create_stack_guard_pages();
636
637 // Initialize Java-Level synchronization subsystem
638 ObjectMonitor::Initialize();
639 ObjectSynchronizer::initialize();
640
641 Deoptimization::init_counters();
642 VMThread::init_counters();
643
644 // Initialize global modules
645 jint status = init_globals();
646 if (status != JNI_OK) {
647 main_thread->smr_delete();
648 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
649 return status;
650 }
651 if (xtty != nullptr)
652 xtty->elem("vm_main_thread thread='" UINTX_FORMAT "'",
653 (uintx) main_thread->osthread()->thread_id());
654
655 // Create WatcherThread as soon as we can since we need it in case
656 // of hangs during error reporting.
657 WatcherThread::start();
658
659 // Add main_thread to threads list to finish barrier setup with
660 // on_thread_attach. Should be before starting to build Java objects in
661 // init_globals2, which invokes barriers.
662 {
663 MutexLocker mu(Threads_lock);
664 Threads::add(main_thread);
665 }
666
667 status = init_globals2();
668 if (status != JNI_OK) {
669 Threads::remove(main_thread, false);
670 // It is possible that we managed to fully initialize Universe but have then
671 // failed by throwing an exception. In that case our caller JNI_CreateJavaVM
672 // will want to report it, so we can't delete the main thread.
673 if (!main_thread->has_pending_exception()) {
674 main_thread->smr_delete();
675 }
676 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
677 return status;
678 }
679
680 ObjectMonitor::Initialize2();
681
682 JFR_ONLY(Jfr::on_create_vm_1();)
683
684 // Should be done after the heap is fully created
685 main_thread->cache_global_variables();
686
687 // Any JVMTI raw monitors entered in onload will transition into
688 // real raw monitor. VM is setup enough here for raw monitor enter.
689 JvmtiExport::transition_pending_onload_raw_monitors();
690
691 // Create the VMThread
692 { TraceTime timer("Start VMThread", TRACETIME_LOG(Info, startuptime));
693
694 VMThread::create();
695 VMThread* vmthread = VMThread::vm_thread();
696
697 if (!os::create_thread(vmthread, os::vm_thread)) {
698 vm_exit_during_initialization("Cannot create VM thread. "
699 "Out of system resources.");
700 }
701
702 // Wait for the VM thread to become ready, and VMThread::run to initialize
703 // Monitors can have spurious returns, must always check another state flag
704 {
705 MonitorLocker ml(Notify_lock);
706 os::start_thread(vmthread);
707 while (!vmthread->is_running()) {
708 ml.wait();
709 }
710 }
711 }
712
713 assert(Universe::is_fully_initialized(), "not initialized");
714 if (VerifyDuringStartup) {
715 // Make sure we're starting with a clean slate.
716 VM_Verify verify_op;
717 VMThread::execute(&verify_op);
718 }
719
720 // We need this to update the java.vm.info property in case any flags used
721 // to initially define it have been changed. This is needed for both CDS
722 // since UseSharedSpaces may be changed after java.vm.info
723 // is initially computed. See Abstract_VM_Version::vm_info_string().
724 // This update must happen before we initialize the java classes, but
725 // after any initialization logic that might modify the flags.
726 Arguments::update_vm_info_property(VM_Version::vm_info_string());
727
728 JavaThread* THREAD = JavaThread::current(); // For exception macros.
729 HandleMark hm(THREAD);
730
731 // Always call even when there are not JVMTI environments yet, since environments
732 // may be attached late and JVMTI must track phases of VM execution
733 JvmtiExport::enter_early_start_phase();
734
735 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
736 JvmtiExport::post_early_vm_start();
737
738 // Launch -Xrun agents early if EagerXrunInit is set
739 if (EagerXrunInit) {
740 JvmtiAgentList::load_xrun_agents();
741 }
742
743 initialize_java_lang_classes(main_thread, CHECK_JNI_ERR);
744
745 quicken_jni_functions();
746
747 // No more stub generation allowed after that point.
748 StubCodeDesc::freeze();
749
750 // Set flag that basic initialization has completed. Used by exceptions and various
751 // debug stuff, that does not work until all basic classes have been initialized.
752 set_init_completed();
753
754 LogConfiguration::post_initialize();
755 Metaspace::post_initialize();
756 MutexLockerImpl::post_initialize();
757
758 HOTSPOT_VM_INIT_END();
759
760 // record VM initialization completion time
761 #if INCLUDE_MANAGEMENT
762 Management::record_vm_init_completed();
763 #endif // INCLUDE_MANAGEMENT
764
765 log_info(os)("Initialized VM with process ID %d", os::current_process_id());
766
767 if (!FLAG_IS_DEFAULT(CreateCoredumpOnCrash) && CreateCoredumpOnCrash) {
768 char buffer[2*JVM_MAXPATHLEN];
769 os::check_core_dump_prerequisites(buffer, sizeof(buffer), true);
770 }
771
772 // Signal Dispatcher needs to be started before VMInit event is posted
773 os::initialize_jdk_signal_support(CHECK_JNI_ERR);
774
775 // Start Attach Listener if +StartAttachListener or it can't be started lazily
776 if (!DisableAttachMechanism) {
777 AttachListener::vm_start();
778 if (StartAttachListener || AttachListener::init_at_startup()) {
779 AttachListener::init();
780 }
781 }
782
783 // Launch -Xrun agents if EagerXrunInit is not set.
784 if (!EagerXrunInit) {
785 JvmtiAgentList::load_xrun_agents();
786 }
787
788 Arena::start_chunk_pool_cleaner_task();
789
790 // Start the service thread
791 // The service thread enqueues JVMTI deferred events and does various hashtable
792 // and other cleanups. Needs to start before the compilers start posting events.
793 ServiceThread::initialize();
794
795 // Start the monitor deflation thread:
796 MonitorDeflationThread::initialize();
797
798 #if INCLUDE_CDS
799 // Start the method sampler
800 MethodProfiler::initialize();
801 #endif
802
803 bool force_JVMCI_initialization = initialize_compilation(CHECK_JNI_ERR);
804
805 if (CDSConfig::is_using_aot_linked_classes()) {
806 AOTLinkedClassBulkLoader::finish_loading_javabase_classes(CHECK_JNI_ERR);
807 SystemDictionary::restore_archived_method_handle_intrinsics();
808 }
809
810 // Start string deduplication thread if requested.
811 if (StringDedup::is_enabled()) {
812 StringDedup::start();
813 }
814
815 // Pre-initialize some JSR292 core classes to avoid deadlock during class loading.
816 // It is done after compilers are initialized, because otherwise compilations of
817 // signature polymorphic MH intrinsics can be missed
818 // (see SystemDictionary::find_method_handle_intrinsic).
819 initialize_jsr292_core_classes(CHECK_JNI_ERR);
820
821 // This will initialize the module system. Only java.base classes can be
822 // loaded until phase 2 completes
823 call_initPhase2(CHECK_JNI_ERR);
824
825 if (CDSConfig::is_using_aot_linked_classes() && !CDSConfig::is_dumping_final_static_archive()) {
826 AOTLinkedClassBulkLoader::load_non_javabase_classes(THREAD);
827 }
828 #ifndef PRODUCT
829 HeapShared::initialize_test_class_from_archive(THREAD);
830 #endif
831
832 JFR_ONLY(Jfr::on_create_vm_2();)
833
834 // Always call even when there are not JVMTI environments yet, since environments
835 // may be attached late and JVMTI must track phases of VM execution
836 JvmtiExport::enter_start_phase();
837
838 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
839 JvmtiExport::post_vm_start();
840
841 // Final system initialization including security manager and system class loader
842 call_initPhase3(CHECK_JNI_ERR);
843
844 // cache the system and platform class loaders
845 SystemDictionary::compute_java_loaders(CHECK_JNI_ERR);
846
847 // Initiate replay training processing once preloading is over.
848 CompileBroker::init_training_replay();
849
850 AOTLinkedClassBulkLoader::replay_training_at_init_for_preloaded_classes(CHECK_JNI_ERR);
851
852 if (Continuations::enabled()) {
853 // Initialize Continuation class now so that failure to create enterSpecial/doYield
854 // special nmethods due to limited CodeCache size can be treated as a fatal error at
855 // startup with the proper message that CodeCache size is too small.
856 initialize_class(vmSymbols::jdk_internal_vm_Continuation(), CHECK_JNI_ERR);
857 }
858
859 #if INCLUDE_CDS
860 // capture the module path info from the ModuleEntryTable
861 ClassLoader::initialize_module_path(THREAD);
862 if (HAS_PENDING_EXCEPTION) {
863 java_lang_Throwable::print(PENDING_EXCEPTION, tty);
864 vm_exit_during_initialization("ClassLoader::initialize_module_path() failed unexpectedly");
865 }
866 #endif
867
868 #if INCLUDE_JVMCI
869 if (force_JVMCI_initialization) {
870 JVMCI::initialize_compiler(CHECK_JNI_ERR);
871 }
872 #endif
873
874 if (PrecompileCode) {
875 Precompiler::compile_cached_code(CHECK_JNI_ERR);
876 if (PrecompileOnlyAndExit) {
877 SCCache::close();
878 log_vm_init_stats();
879 vm_direct_exit(0, "Code precompiation is over");
880 }
881 }
882
883 #if defined(COMPILER2)
884 // Pre-load cached compiled methods
885 SCCache::preload_code(CHECK_JNI_ERR);
886 #endif
887
888 if (NativeHeapTrimmer::enabled()) {
889 NativeHeapTrimmer::initialize();
890 }
891
892 // Always call even when there are not JVMTI environments yet, since environments
893 // may be attached late and JVMTI must track phases of VM execution
894 JvmtiExport::enter_live_phase();
895
896 // Make perfmemory accessible
897 PerfMemory::set_accessible(true);
898
899 // Notify JVMTI agents that VM initialization is complete - nop if no agents.
900 JvmtiExport::post_vm_initialized();
901
902 JFR_ONLY(Jfr::on_create_vm_3();)
903
904 #if INCLUDE_MANAGEMENT
905 Management::initialize(THREAD);
906
907 if (HAS_PENDING_EXCEPTION) {
908 // management agent fails to start possibly due to
909 // configuration problem and is responsible for printing
910 // stack trace if appropriate. Simply exit VM.
911 vm_exit(1);
912 }
913 #endif // INCLUDE_MANAGEMENT
914
915 StatSampler::engage();
916 if (CheckJNICalls) JniPeriodicChecker::engage();
917
918 call_postVMInitHook(THREAD);
919 // The Java side of PostVMInitHook.run must deal with all
920 // exceptions and provide means of diagnosis.
921 if (HAS_PENDING_EXCEPTION) {
922 CLEAR_PENDING_EXCEPTION;
923 }
924
925 // Let WatcherThread run all registered periodic tasks now.
926 // NOTE: All PeriodicTasks should be registered by now. If they
927 // aren't, late joiners might appear to start slowly (we might
928 // take a while to process their first tick).
929 WatcherThread::run_all_tasks();
930
931 create_vm_timer.end();
932 #ifdef ASSERT
933 _vm_complete = true;
934 #endif
935
936 if (CDSConfig::is_dumping_classic_static_archive()) {
937 // Classic -Xshare:dump, aka "old workflow"
938 MetaspaceShared::preload_and_dump(CHECK_JNI_ERR);
939 } else if (CDSConfig::is_dumping_final_static_archive()) {
940 // TODO: copy the verification and loader constraints from preimage to final image
941 // TODO: load archived classes for custom loaders as well.
942 log_info(cds)("Dumping final image of CacheDataStore %s", CacheDataStore);
943 MetaspaceShared::preload_and_dump(CHECK_JNI_ERR);
944 vm_direct_exit(0, "CacheDataStore dumping is complete");
945 }
946
947 log_info(init)("At VM initialization completion:");
948 log_vm_init_stats();
949
950 if (UsePerfData) {
951 if (ProfileVMLocks) {
952 main_thread->set_profile_vm_locks(true);
953 }
954 if (ProfileVMCalls) {
955 main_thread->set_profile_vm_calls(true);
956 }
957 if (ProfileRuntimeCalls) {
958 main_thread->set_profile_rt_calls(true);
959 }
960 if (ProfileVMOps) {
961 main_thread->set_profile_vm_ops(true);
962 }
963 }
964
965 return JNI_OK;
966 }
967
968 // Threads::destroy_vm() is normally called from jni_DestroyJavaVM() when
969 // the program falls off the end of main(). Another VM exit path is through
970 // vm_exit(), when the program calls System.exit() to return a value, or when
971 // there is a serious error in VM.
972 // These two separate shutdown paths are not exactly the same, but they share
973 // Shutdown.shutdown() at Java level and before_exit() and VM_Exit op at VM level.
974 //
975 // Shutdown sequence:
976 // + Shutdown native memory tracking if it is on
977 // + Wait until we are the last non-daemon thread to execute
978 // <-- every thing is still working at this moment -->
979 // + Call java.lang.Shutdown.shutdown(), which will invoke Java level
980 // shutdown hooks
981 // + Call before_exit(), prepare for VM exit
982 // > run VM level shutdown hooks (they are registered through JVM_OnExit(),
983 // currently the only user of this mechanism is File.deleteOnExit())
984 // > stop StatSampler, watcher thread,
985 // post thread end and vm death events to JVMTI,
986 // stop signal thread
987 // + Call JavaThread::exit(), it will:
988 // > release JNI handle blocks, remove stack guard pages
989 // > remove this thread from Threads list
990 // <-- no more Java code from this thread after this point -->
991 // + Stop VM thread, it will bring the remaining VM to a safepoint and stop
992 // the compiler threads at safepoint
993 // <-- do not use anything that could get blocked by Safepoint -->
994 // + Disable tracing at JNI/JVM barriers
995 // + Set _vm_exited flag for threads that are still running native code
996 // + Call exit_globals()
997 // > deletes tty
998 // > deletes PerfMemory resources
999 // + Delete this thread
1000 // + Return to caller
1001
1002 void Threads::destroy_vm() {
1003 JavaThread* thread = JavaThread::current();
1004
1005 #ifdef ASSERT
1006 _vm_complete = false;
1007 #endif
1008 // Wait until we are the last non-daemon thread to execute, or
1009 // if we are a daemon then wait until the last non-daemon thread has
1010 // executed.
1011 bool daemon = java_lang_Thread::is_daemon(thread->threadObj());
1012 int expected = daemon ? 0 : 1;
1013 {
1014 MonitorLocker nu(Threads_lock);
1015 while (Threads::number_of_non_daemon_threads() > expected)
1016 // This wait should make safepoint checks, wait without a timeout.
1017 nu.wait(0);
1018 }
1019
1020 EventShutdown e;
1021 if (e.should_commit()) {
1022 e.set_reason("No remaining non-daemon Java threads");
1023 e.commit();
1024 }
1025
1026 // Hang forever on exit if we are reporting an error.
1027 if (ShowMessageBoxOnError && VMError::is_error_reported()) {
1028 os::infinite_sleep();
1029 }
1030 os::wait_for_keypress_at_exit();
1031
1032 // run Java level shutdown hooks
1033 thread->invoke_shutdown_hooks();
1034
1035 before_exit(thread);
1036
1037 thread->exit(true);
1038
1039 // We are no longer on the main thread list but could still be in a
1040 // secondary list where another thread may try to interact with us.
1041 // So wait until all such interactions are complete before we bring
1042 // the VM to the termination safepoint. Normally this would be done
1043 // using thread->smr_delete() below where we delete the thread, but
1044 // we can't call that after the termination safepoint is active as
1045 // we will deadlock on the Threads_lock. Once all interactions are
1046 // complete it is safe to directly delete the thread at any time.
1047 ThreadsSMRSupport::wait_until_not_protected(thread);
1048
1049 // Stop VM thread.
1050 {
1051 // 4945125 The vm thread comes to a safepoint during exit.
1052 // GC vm_operations can get caught at the safepoint, and the
1053 // heap is unparseable if they are caught. Grab the Heap_lock
1054 // to prevent this. The GC vm_operations will not be able to
1055 // queue until after the vm thread is dead. After this point,
1056 // we'll never emerge out of the safepoint before the VM exits.
1057 // Assert that the thread is terminated so that acquiring the
1058 // Heap_lock doesn't cause the terminated thread to participate in
1059 // the safepoint protocol.
1060
1061 assert(thread->is_terminated(), "must be terminated here");
1062 MutexLocker ml(Heap_lock);
1063
1064 VMThread::wait_for_vm_thread_exit();
1065 assert(SafepointSynchronize::is_at_safepoint(), "VM thread should exit at Safepoint");
1066 VMThread::destroy();
1067 }
1068
1069 // Now, all Java threads are gone except daemon threads. Daemon threads
1070 // running Java code or in VM are stopped by the Safepoint. However,
1071 // daemon threads executing native code are still running. But they
1072 // will be stopped at native=>Java/VM barriers. Note that we can't
1073 // simply kill or suspend them, as it is inherently deadlock-prone.
1074
1075 VM_Exit::set_vm_exited();
1076
1077 // Clean up ideal graph printers after the VMThread has started
1078 // the final safepoint which will block all the Compiler threads.
1079 // Note that this Thread has already logically exited so the
1080 // clean_up() function's use of a JavaThreadIteratorWithHandle
1081 // would be a problem except set_vm_exited() has remembered the
1082 // shutdown thread which is granted a policy exception.
1083 #if defined(COMPILER2) && !defined(PRODUCT)
1084 IdealGraphPrinter::clean_up();
1085 #endif
1086
1087 notify_vm_shutdown();
1088
1089 // exit_globals() will delete tty
1090 exit_globals();
1091
1092 // Deleting the shutdown thread here is safe. See comment on
1093 // wait_until_not_protected() above.
1094 delete thread;
1095
1096 #if INCLUDE_JVMCI
1097 if (JVMCICounterSize > 0) {
1098 FREE_C_HEAP_ARRAY(jlong, JavaThread::_jvmci_old_thread_counters);
1099 }
1100 #endif
1101
1102 LogConfiguration::finalize();
1103 }
1104
1105
1106 jboolean Threads::is_supported_jni_version_including_1_1(jint version) {
1107 if (version == JNI_VERSION_1_1) return JNI_TRUE;
1108 return is_supported_jni_version(version);
1109 }
1110
1111
1112 jboolean Threads::is_supported_jni_version(jint version) {
1113 if (version == JNI_VERSION_1_2) return JNI_TRUE;
1114 if (version == JNI_VERSION_1_4) return JNI_TRUE;
1115 if (version == JNI_VERSION_1_6) return JNI_TRUE;
1116 if (version == JNI_VERSION_1_8) return JNI_TRUE;
1117 if (version == JNI_VERSION_9) return JNI_TRUE;
1118 if (version == JNI_VERSION_10) return JNI_TRUE;
1119 if (version == JNI_VERSION_19) return JNI_TRUE;
1120 if (version == JNI_VERSION_20) return JNI_TRUE;
1121 if (version == JNI_VERSION_21) return JNI_TRUE;
1122 if (version == JNI_VERSION_24) return JNI_TRUE;
1123 return JNI_FALSE;
1124 }
1125
1126 void Threads::add(JavaThread* p, bool force_daemon) {
1127 // The threads lock must be owned at this point
1128 assert(Threads_lock->owned_by_self(), "must have threads lock");
1129
1130 BarrierSet::barrier_set()->on_thread_attach(p);
1131
1132 // Once a JavaThread is added to the Threads list, smr_delete() has
1133 // to be used to delete it. Otherwise we can just delete it directly.
1134 p->set_on_thread_list();
1135
1136 _number_of_threads++;
1137 oop threadObj = p->threadObj();
1138 bool daemon = true;
1139 // Bootstrapping problem: threadObj can be null for initial
1140 // JavaThread (or for threads attached via JNI)
1141 if (!force_daemon &&
1142 (threadObj == nullptr || !java_lang_Thread::is_daemon(threadObj))) {
1143 _number_of_non_daemon_threads++;
1144 daemon = false;
1145 }
1146
1147 ThreadService::add_thread(p, daemon);
1148
1149 // Maintain fast thread list
1150 ThreadsSMRSupport::add_thread(p);
1151
1152 // Increase the ObjectMonitor ceiling for the new thread.
1153 ObjectSynchronizer::inc_in_use_list_ceiling();
1154
1155 // Possible GC point.
1156 Events::log(Thread::current(), "Thread added: " INTPTR_FORMAT, p2i(p));
1157
1158 // Make new thread known to active EscapeBarrier
1159 EscapeBarrier::thread_added(p);
1160 }
1161
1162 void Threads::remove(JavaThread* p, bool is_daemon) {
1163 // Extra scope needed for Thread_lock, so we can check
1164 // that we do not remove thread without safepoint code notice
1165 {
1166 ConditionalMutexLocker throttle_ml(ThreadsLockThrottle_lock, UseThreadsLockThrottleLock);
1167 MonitorLocker ml(Threads_lock);
1168
1169 if (ThreadIdTable::is_initialized()) {
1170 // This cleanup must be done before the current thread's GC barrier
1171 // is detached since we need to touch the threadObj oop.
1172 jlong tid = SharedRuntime::get_java_tid(p);
1173 ThreadIdTable::remove_thread(tid);
1174 }
1175
1176 // BarrierSet state must be destroyed after the last thread transition
1177 // before the thread terminates. Thread transitions result in calls to
1178 // StackWatermarkSet::on_safepoint(), which performs GC processing,
1179 // requiring the GC state to be alive.
1180 BarrierSet::barrier_set()->on_thread_detach(p);
1181 if (p->is_exiting()) {
1182 // If we got here via JavaThread::exit(), then we remember that the
1183 // thread's GC barrier has been detached. We don't do this when we get
1184 // here from another path, e.g., cleanup_failed_attach_current_thread().
1185 p->set_terminated(JavaThread::_thread_gc_barrier_detached);
1186 }
1187
1188 assert(ThreadsSMRSupport::get_java_thread_list()->includes(p), "p must be present");
1189
1190 // Maintain fast thread list
1191 ThreadsSMRSupport::remove_thread(p);
1192
1193 _number_of_threads--;
1194 if (!is_daemon) {
1195 _number_of_non_daemon_threads--;
1196
1197 // If this is the last non-daemon thread then we need to do
1198 // a notify on the Threads_lock so a thread waiting
1199 // on destroy_vm will wake up. But that thread could be a daemon
1200 // or non-daemon, so we notify for both the 0 and 1 case.
1201 if (number_of_non_daemon_threads() <= 1) {
1202 ml.notify_all();
1203 }
1204 }
1205 ThreadService::remove_thread(p, is_daemon);
1206
1207 // Make sure that safepoint code disregard this thread. This is needed since
1208 // the thread might mess around with locks after this point. This can cause it
1209 // to do callbacks into the safepoint code. However, the safepoint code is not aware
1210 // of this thread since it is removed from the queue.
1211 p->set_terminated(JavaThread::_thread_terminated);
1212
1213 // Notify threads waiting in EscapeBarriers
1214 EscapeBarrier::thread_removed(p);
1215 } // unlock Threads_lock and ThreadsLockThrottle_lock
1216
1217 // Reduce the ObjectMonitor ceiling for the exiting thread.
1218 ObjectSynchronizer::dec_in_use_list_ceiling();
1219
1220 // Since Events::log uses a lock, we grab it outside the Threads_lock
1221 Events::log(Thread::current(), "Thread exited: " INTPTR_FORMAT, p2i(p));
1222 }
1223
1224 // Operations on the Threads list for GC. These are not explicitly locked,
1225 // but the garbage collector must provide a safe context for them to run.
1226 // In particular, these things should never be called when the Threads_lock
1227 // is held by some other thread. (Note: the Safepoint abstraction also
1228 // uses the Threads_lock to guarantee this property. It also makes sure that
1229 // all threads gets blocked when exiting or starting).
1230
1231 void Threads::oops_do(OopClosure* f, NMethodClosure* cf) {
1232 ALL_JAVA_THREADS(p) {
1233 p->oops_do(f, cf);
1234 }
1235 VMThread::vm_thread()->oops_do(f, cf);
1236 }
1237
1238 void Threads::change_thread_claim_token() {
1239 if (++_thread_claim_token == 0) {
1240 // On overflow of the token counter, there is a risk of future
1241 // collisions between a new global token value and a stale token
1242 // for a thread, because not all iterations visit all threads.
1243 // (Though it's pretty much a theoretical concern for non-trivial
1244 // token counter sizes.) To deal with the possibility, reset all
1245 // the thread tokens to zero on global token overflow.
1246 struct ResetClaims : public ThreadClosure {
1247 virtual void do_thread(Thread* t) {
1248 t->claim_threads_do(false, 0);
1249 }
1250 } reset_claims;
1251 Threads::threads_do(&reset_claims);
1252 // On overflow, update the global token to non-zero, to
1253 // avoid the special "never claimed" initial thread value.
1254 _thread_claim_token = 1;
1255 }
1256 }
1257
1258 #ifdef ASSERT
1259 static void assert_thread_claimed(const char* kind, Thread* t, uintx expected) {
1260 const uintx token = t->threads_do_token();
1261 assert(token == expected,
1262 "%s " PTR_FORMAT " has incorrect value " UINTX_FORMAT " != "
1263 UINTX_FORMAT, kind, p2i(t), token, expected);
1264 }
1265
1266 void Threads::assert_all_threads_claimed() {
1267 ALL_JAVA_THREADS(p) {
1268 assert_thread_claimed("JavaThread", p, _thread_claim_token);
1269 }
1270
1271 struct NJTClaimedVerifierClosure : public ThreadClosure {
1272 uintx _thread_claim_token;
1273
1274 NJTClaimedVerifierClosure(uintx thread_claim_token) : ThreadClosure(), _thread_claim_token(thread_claim_token) { }
1275
1276 virtual void do_thread(Thread* thread) override {
1277 assert_thread_claimed("Non-JavaThread", VMThread::vm_thread(), _thread_claim_token);
1278 }
1279 } tc(_thread_claim_token);
1280
1281 non_java_threads_do(&tc);
1282 }
1283 #endif // ASSERT
1284
1285 class ParallelOopsDoThreadClosure : public ThreadClosure {
1286 private:
1287 OopClosure* _f;
1288 NMethodClosure* _cf;
1289 public:
1290 ParallelOopsDoThreadClosure(OopClosure* f, NMethodClosure* cf) : _f(f), _cf(cf) {}
1291 void do_thread(Thread* t) {
1292 t->oops_do(_f, _cf);
1293 }
1294 };
1295
1296 void Threads::possibly_parallel_oops_do(bool is_par, OopClosure* f, NMethodClosure* cf) {
1297 ParallelOopsDoThreadClosure tc(f, cf);
1298 possibly_parallel_threads_do(is_par, &tc);
1299 }
1300
1301 void Threads::metadata_do(MetadataClosure* f) {
1302 ALL_JAVA_THREADS(p) {
1303 p->metadata_do(f);
1304 }
1305 }
1306
1307 class ThreadHandlesClosure : public ThreadClosure {
1308 void (*_f)(Metadata*);
1309 public:
1310 ThreadHandlesClosure(void f(Metadata*)) : _f(f) {}
1311 virtual void do_thread(Thread* thread) {
1312 thread->metadata_handles_do(_f);
1313 }
1314 };
1315
1316 void Threads::metadata_handles_do(void f(Metadata*)) {
1317 // Only walk the Handles in Thread.
1318 ThreadHandlesClosure handles_closure(f);
1319 threads_do(&handles_closure);
1320 }
1321
1322 #if INCLUDE_JVMTI
1323 // Get Java threads that are waiting to enter or re-enter the specified monitor.
1324 // Java threads that are executing mounted virtual threads are not included.
1325 GrowableArray<JavaThread*>* Threads::get_pending_threads(ThreadsList * t_list,
1326 int count,
1327 address monitor) {
1328 assert(Thread::current()->is_VM_thread(), "Must be the VM thread");
1329 GrowableArray<JavaThread*>* result = new GrowableArray<JavaThread*>(count);
1330
1331 int i = 0;
1332 for (JavaThread* p : *t_list) {
1333 if (!p->can_call_java()) continue;
1334
1335 oop thread_oop = JvmtiEnvBase::get_vthread_or_thread_oop(p);
1336 if (thread_oop->is_a(vmClasses::BaseVirtualThread_klass())) {
1337 continue;
1338 }
1339 // The first stage of async deflation does not affect any field
1340 // used by this comparison so the ObjectMonitor* is usable here.
1341 address pending = (address)p->current_pending_monitor();
1342 address waiting = (address)p->current_waiting_monitor();
1343 // do not include virtual threads to the list
1344 jint state = JvmtiEnvBase::get_thread_state(thread_oop, p);
1345 if (pending == monitor || (waiting == monitor &&
1346 (state & JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER))
1347 ) { // found a match
1348 if (i < count) result->append(p); // save the first count matches
1349 i++;
1350 }
1351 }
1352
1353 return result;
1354 }
1355 #endif // INCLUDE_JVMTI
1356
1357 JavaThread *Threads::owning_thread_from_stacklock(ThreadsList * t_list, address basicLock) {
1358 assert(LockingMode == LM_LEGACY, "Not with new lightweight locking");
1359
1360 JavaThread* the_owner = nullptr;
1361 for (JavaThread* q : *t_list) {
1362 if (q->is_lock_owned(basicLock)) {
1363 the_owner = q;
1364 break;
1365 }
1366 }
1367 return the_owner;
1368 }
1369
1370 JavaThread* Threads::owning_thread_from_object(ThreadsList * t_list, oop obj) {
1371 assert(LockingMode == LM_LIGHTWEIGHT, "Only with new lightweight locking");
1372 for (JavaThread* q : *t_list) {
1373 // Need to start processing before accessing oops in the thread.
1374 StackWatermark* watermark = StackWatermarkSet::get(q, StackWatermarkKind::gc);
1375 if (watermark != nullptr) {
1376 watermark->start_processing();
1377 }
1378
1379 if (q->lock_stack().contains(obj)) {
1380 return q;
1381 }
1382 }
1383 return nullptr;
1384 }
1385
1386 JavaThread* Threads::owning_thread_from_monitor(ThreadsList* t_list, ObjectMonitor* monitor) {
1387 if (monitor->has_anonymous_owner()) {
1388 if (LockingMode == LM_LIGHTWEIGHT) {
1389 return owning_thread_from_object(t_list, monitor->object());
1390 } else {
1391 assert(LockingMode == LM_LEGACY, "invariant");
1392 return owning_thread_from_stacklock(t_list, (address)monitor->stack_locker());
1393 }
1394 } else {
1395 JavaThread* the_owner = nullptr;
1396 for (JavaThread* q : *t_list) {
1397 if (monitor->has_owner(q)) {
1398 the_owner = q;
1399 break;
1400 }
1401 }
1402 return the_owner;
1403 }
1404 }
1405
1406 class PrintOnClosure : public ThreadClosure {
1407 private:
1408 outputStream* _st;
1409
1410 public:
1411 PrintOnClosure(outputStream* st) :
1412 _st(st) {}
1413
1414 virtual void do_thread(Thread* thread) {
1415 if (thread != nullptr) {
1416 thread->print_on(_st);
1417 _st->cr();
1418 }
1419 }
1420 };
1421
1422 // Threads::print_on() is called at safepoint by VM_PrintThreads operation.
1423 void Threads::print_on(outputStream* st, bool print_stacks,
1424 bool internal_format, bool print_concurrent_locks,
1425 bool print_extended_info) {
1426 char buf[32];
1427 st->print_raw_cr(os::local_time_string(buf, sizeof(buf)));
1428
1429 st->print_cr("Full thread dump %s (%s %s):",
1430 VM_Version::vm_name(),
1431 VM_Version::vm_release(),
1432 VM_Version::vm_info_string());
1433 st->cr();
1434
1435 #if INCLUDE_SERVICES
1436 // Dump concurrent locks
1437 ConcurrentLocksDump concurrent_locks;
1438 if (print_concurrent_locks) {
1439 concurrent_locks.dump_at_safepoint();
1440 }
1441 #endif // INCLUDE_SERVICES
1442
1443 ThreadsSMRSupport::print_info_on(st);
1444 st->cr();
1445
1446 ALL_JAVA_THREADS(p) {
1447 ResourceMark rm;
1448 p->print_on(st, print_extended_info);
1449 if (print_stacks) {
1450 if (internal_format) {
1451 p->trace_stack();
1452 } else {
1453 p->print_stack_on(st);
1454 if (p->is_vthread_mounted()) {
1455 // _lock_id is the thread ID of the mounted virtual thread
1456 st->print_cr(" Mounted virtual thread #" INT64_FORMAT, p->lock_id());
1457 p->print_vthread_stack_on(st);
1458 }
1459 }
1460 }
1461 st->cr();
1462 #if INCLUDE_SERVICES
1463 if (print_concurrent_locks) {
1464 concurrent_locks.print_locks_on(p, st);
1465 }
1466 #endif // INCLUDE_SERVICES
1467 }
1468
1469 PrintOnClosure cl(st);
1470 non_java_threads_do(&cl);
1471
1472 st->flush();
1473 }
1474
1475 void Threads::print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
1476 int buflen, bool* found_current) {
1477 if (this_thread != nullptr) {
1478 bool is_current = (current == this_thread);
1479 *found_current = *found_current || is_current;
1480 st->print("%s", is_current ? "=>" : " ");
1481
1482 st->print(PTR_FORMAT, p2i(this_thread));
1483 st->print(" ");
1484 this_thread->print_on_error(st, buf, buflen);
1485 st->cr();
1486 }
1487 }
1488
1489 class PrintOnErrorClosure : public ThreadClosure {
1490 outputStream* _st;
1491 Thread* _current;
1492 char* _buf;
1493 int _buflen;
1494 bool* _found_current;
1495 unsigned _num_printed;
1496 public:
1497 PrintOnErrorClosure(outputStream* st, Thread* current, char* buf,
1498 int buflen, bool* found_current) :
1499 _st(st), _current(current), _buf(buf), _buflen(buflen), _found_current(found_current),
1500 _num_printed(0) {}
1501
1502 virtual void do_thread(Thread* thread) {
1503 _num_printed++;
1504 Threads::print_on_error(thread, _st, _current, _buf, _buflen, _found_current);
1505 }
1506
1507 unsigned num_printed() const { return _num_printed; }
1508 };
1509
1510 // Threads::print_on_error() is called by fatal error handler. It's possible
1511 // that VM is not at safepoint and/or current thread is inside signal handler.
1512 // Don't print stack trace, as the stack may not be walkable. Don't allocate
1513 // memory (even in resource area), it might deadlock the error handler.
1514 void Threads::print_on_error(outputStream* st, Thread* current, char* buf,
1515 int buflen) {
1516 ThreadsSMRSupport::print_info_on(st);
1517 st->cr();
1518
1519 bool found_current = false;
1520 st->print_cr("Java Threads: ( => current thread )");
1521 unsigned num_java = 0;
1522 ALL_JAVA_THREADS(thread) {
1523 print_on_error(thread, st, current, buf, buflen, &found_current);
1524 num_java++;
1525 }
1526 st->print_cr("Total: %u", num_java);
1527 st->cr();
1528
1529 st->print_cr("Other Threads:");
1530 unsigned num_other = ((VMThread::vm_thread() != nullptr) ? 1 : 0) +
1531 ((WatcherThread::watcher_thread() != nullptr) ? 1 : 0) +
1532 ((AsyncLogWriter::instance() != nullptr) ? 1 : 0);
1533 print_on_error(VMThread::vm_thread(), st, current, buf, buflen, &found_current);
1534 print_on_error(WatcherThread::watcher_thread(), st, current, buf, buflen, &found_current);
1535 print_on_error(AsyncLogWriter::instance(), st, current, buf, buflen, &found_current);
1536
1537 if (Universe::heap() != nullptr) {
1538 PrintOnErrorClosure print_closure(st, current, buf, buflen, &found_current);
1539 Universe::heap()->gc_threads_do(&print_closure);
1540 num_other += print_closure.num_printed();
1541 }
1542
1543 if (!found_current) {
1544 st->cr();
1545 st->print("=>" PTR_FORMAT " (exited) ", p2i(current));
1546 current->print_on_error(st, buf, buflen);
1547 num_other++;
1548 st->cr();
1549 }
1550 st->print_cr("Total: %u", num_other);
1551 st->cr();
1552
1553 st->print_cr("Threads with active compile tasks:");
1554 unsigned num = print_threads_compiling(st, buf, buflen);
1555 st->print_cr("Total: %u", num);
1556 }
1557
1558 unsigned Threads::print_threads_compiling(outputStream* st, char* buf, int buflen, bool short_form) {
1559 unsigned num = 0;
1560 ALL_JAVA_THREADS(thread) {
1561 if (thread->is_Compiler_thread()) {
1562 CompilerThread* ct = (CompilerThread*) thread;
1563
1564 // Keep task in local variable for null check.
1565 // ct->_task might be set to null by concurring compiler thread
1566 // because it completed the compilation. The task is never freed,
1567 // though, just returned to a free list.
1568 CompileTask* task = ct->task();
1569 if (task != nullptr) {
1570 thread->print_name_on_error(st, buf, buflen);
1571 st->print(" ");
1572 task->print(st, nullptr, short_form, true);
1573 num++;
1574 }
1575 }
1576 }
1577 return num;
1578 }
1579
1580 void Threads::verify() {
1581 ALL_JAVA_THREADS(p) {
1582 p->verify();
1583 }
1584 VMThread* thread = VMThread::vm_thread();
1585 if (thread != nullptr) thread->verify();
1586 }