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