1 /*
2 * Copyright (c) 1997, 2023, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2021, Azul Systems, Inc. All rights reserved.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26 #include "precompiled.hpp"
27 #include "cds/cds_globals.hpp"
28 #include "cds/metaspaceShared.hpp"
29 #include "classfile/classLoader.hpp"
30 #include "classfile/javaClasses.hpp"
31 #include "classfile/javaThreadStatus.hpp"
32 #include "classfile/systemDictionary.hpp"
33 #include "classfile/vmClasses.hpp"
34 #include "classfile/vmSymbols.hpp"
35 #include "compiler/compileBroker.hpp"
36 #include "compiler/compileTask.hpp"
37 #include "compiler/compilerThread.hpp"
38 #include "gc/shared/barrierSet.hpp"
39 #include "gc/shared/barrierSetNMethod.hpp"
40 #include "gc/shared/gcVMOperations.hpp"
41 #include "gc/shared/oopStorage.hpp"
42 #include "gc/shared/oopStorageSet.hpp"
43 #include "gc/shared/stringdedup/stringDedup.hpp"
44 #include "jfr/jfrEvents.hpp"
45 #include "jvm.h"
46 #include "jvmtifiles/jvmtiEnv.hpp"
47 #include "logging/log.hpp"
48 #include "logging/logAsyncWriter.hpp"
49 #include "logging/logConfiguration.hpp"
50 #include "memory/allocation.inline.hpp"
51 #include "memory/iterator.hpp"
52 #include "memory/oopFactory.hpp"
53 #include "memory/resourceArea.hpp"
54 #include "memory/universe.hpp"
55 #include "oops/instanceKlass.hpp"
56 #include "oops/klass.inline.hpp"
57 #include "oops/oop.inline.hpp"
58 #include "oops/symbol.hpp"
59 #include "prims/jvmtiAgentList.hpp"
60 #include "prims/jvm_misc.hpp"
61 #include "runtime/arguments.hpp"
62 #include "runtime/fieldDescriptor.inline.hpp"
63 #include "runtime/flags/jvmFlagLimit.hpp"
64 #include "runtime/handles.inline.hpp"
65 #include "runtime/globals.hpp"
66 #include "runtime/interfaceSupport.inline.hpp"
67 #include "runtime/java.hpp"
68 #include "runtime/javaCalls.hpp"
69 #include "runtime/javaThread.inline.hpp"
70 #include "runtime/jniHandles.inline.hpp"
71 #include "runtime/jniPeriodicChecker.hpp"
72 #include "runtime/lockStack.inline.hpp"
73 #include "runtime/monitorDeflationThread.hpp"
74 #include "runtime/mutexLocker.hpp"
75 #include "runtime/nonJavaThread.hpp"
76 #include "runtime/objectMonitor.inline.hpp"
77 #include "runtime/osThread.hpp"
78 #include "runtime/safepoint.hpp"
79 #include "runtime/safepointMechanism.inline.hpp"
80 #include "runtime/safepointVerifiers.hpp"
81 #include "runtime/serviceThread.hpp"
82 #include "runtime/sharedRuntime.hpp"
83 #include "runtime/statSampler.hpp"
84 #include "runtime/stubCodeGenerator.hpp"
85 #include "runtime/thread.inline.hpp"
86 #include "runtime/threads.hpp"
87 #include "runtime/threadSMR.inline.hpp"
88 #include "runtime/timer.hpp"
89 #include "runtime/timerTrace.hpp"
90 #include "runtime/trimNativeHeap.hpp"
91 #include "runtime/vmOperations.hpp"
92 #include "runtime/vm_version.hpp"
93 #include "services/attachListener.hpp"
94 #include "services/management.hpp"
95 #include "services/memTracker.hpp"
96 #include "services/threadIdTable.hpp"
97 #include "services/threadService.hpp"
98 #include "utilities/dtrace.hpp"
99 #include "utilities/events.hpp"
100 #include "utilities/macros.hpp"
101 #include "utilities/vmError.hpp"
102 #if INCLUDE_JVMCI
103 #include "jvmci/jvmci.hpp"
104 #include "jvmci/jvmciEnv.hpp"
105 #endif
106 #ifdef COMPILER2
107 #include "opto/idealGraphPrinter.hpp"
108 #endif
109 #if INCLUDE_RTM_OPT
110 #include "runtime/rtmLocking.hpp"
111 #endif
112 #if INCLUDE_JFR
113 #include "jfr/jfr.hpp"
114 #endif
115 #if INCLUDE_VM_STRUCTS
116 #include "runtime/vmStructs.hpp"
117 #endif
118
119 // Initialization after module runtime initialization
120 void universe_post_module_init(); // must happen after call_initPhase2
121
122
123 static void initialize_class(Symbol* class_name, TRAPS) {
124 Klass* klass = SystemDictionary::resolve_or_fail(class_name, true, CHECK);
125 InstanceKlass::cast(klass)->initialize(CHECK);
126 }
127
128
129 // Creates the initial ThreadGroup
130 static Handle create_initial_thread_group(TRAPS) {
131 Handle system_instance = JavaCalls::construct_new_instance(
132 vmClasses::ThreadGroup_klass(),
133 vmSymbols::void_method_signature(),
134 CHECK_NH);
135 Universe::set_system_thread_group(system_instance());
136
137 Handle string = java_lang_String::create_from_str("main", CHECK_NH);
138 Handle main_instance = JavaCalls::construct_new_instance(
139 vmClasses::ThreadGroup_klass(),
140 vmSymbols::threadgroup_string_void_signature(),
141 system_instance,
142 string,
143 CHECK_NH);
144 return main_instance;
145 }
146
147 // Creates the initial Thread, and sets it to running.
148 static void create_initial_thread(Handle thread_group, JavaThread* thread,
149 TRAPS) {
150 InstanceKlass* ik = vmClasses::Thread_klass();
151 assert(ik->is_initialized(), "must be");
152 instanceHandle thread_oop = ik->allocate_instance_handle(CHECK);
153
154 // Cannot use JavaCalls::construct_new_instance because the java.lang.Thread
155 // constructor calls Thread.current(), which must be set here for the
156 // initial thread.
157 java_lang_Thread::set_thread(thread_oop(), thread);
158 thread->set_threadOopHandles(thread_oop());
159
160 Handle string = java_lang_String::create_from_str("main", CHECK);
161
162 JavaValue result(T_VOID);
163 JavaCalls::call_special(&result, thread_oop,
164 ik,
165 vmSymbols::object_initializer_name(),
166 vmSymbols::threadgroup_string_void_signature(),
167 thread_group,
168 string,
169 CHECK);
170
171 // Set thread status to running since main thread has
172 // been started and running.
173 java_lang_Thread::set_thread_status(thread_oop(),
174 JavaThreadStatus::RUNNABLE);
175 }
176
177 // Extract version and vendor specific information from
178 // java.lang.VersionProps fields.
179 // Returned char* is allocated in the thread's resource area
180 // so must be copied for permanency.
181 static const char* get_java_version_info(InstanceKlass* ik,
182 Symbol* field_name) {
183 fieldDescriptor fd;
184 bool found = ik != nullptr &&
185 ik->find_local_field(field_name,
186 vmSymbols::string_signature(), &fd);
187 if (found) {
188 oop name_oop = ik->java_mirror()->obj_field(fd.offset());
189 if (name_oop == nullptr) {
190 return nullptr;
191 }
192 const char* name = java_lang_String::as_utf8_string(name_oop);
193 return name;
194 } else {
195 return nullptr;
196 }
197 }
198
199 // ======= Threads ========
200
201 // The Threads class links together all active threads, and provides
202 // operations over all threads. It is protected by the Threads_lock,
203 // which is also used in other global contexts like safepointing.
204 // ThreadsListHandles are used to safely perform operations on one
205 // or more threads without the risk of the thread exiting during the
206 // operation.
207 //
208 // Note: The Threads_lock is currently more widely used than we
209 // would like. We are actively migrating Threads_lock uses to other
210 // mechanisms in order to reduce Threads_lock contention.
211
212 int Threads::_number_of_threads = 0;
213 int Threads::_number_of_non_daemon_threads = 0;
214 int Threads::_return_code = 0;
215 uintx Threads::_thread_claim_token = 1; // Never zero.
216
217 #ifdef ASSERT
218 bool Threads::_vm_complete = false;
219 #endif
220
221 // General purpose hook into Java code, run once when the VM is initialized.
222 // The Java library method itself may be changed independently from the VM.
223 static void call_postVMInitHook(TRAPS) {
224 Klass* klass = SystemDictionary::resolve_or_null(vmSymbols::jdk_internal_vm_PostVMInitHook(), THREAD);
225 if (klass != nullptr) {
226 JavaValue result(T_VOID);
227 JavaCalls::call_static(&result, klass, vmSymbols::run_method_name(),
228 vmSymbols::void_method_signature(),
229 CHECK);
230 }
231 }
232
233 // All NonJavaThreads (i.e., every non-JavaThread in the system).
234 void Threads::non_java_threads_do(ThreadClosure* tc) {
235 NoSafepointVerifier nsv;
236 for (NonJavaThread::Iterator njti; !njti.end(); njti.step()) {
237 tc->do_thread(njti.current());
238 }
239 }
240
241 // All JavaThreads
242 #define ALL_JAVA_THREADS(X) \
243 for (JavaThread* X : *ThreadsSMRSupport::get_java_thread_list())
244
245 // All JavaThreads
246 void Threads::java_threads_do(ThreadClosure* tc) {
247 assert_locked_or_safepoint(Threads_lock);
248 // ALL_JAVA_THREADS iterates through all JavaThreads.
249 ALL_JAVA_THREADS(p) {
250 tc->do_thread(p);
251 }
252 }
253
254 // All JavaThreads + all non-JavaThreads (i.e., every thread in the system).
255 void Threads::threads_do(ThreadClosure* tc) {
256 assert_locked_or_safepoint(Threads_lock);
257 java_threads_do(tc);
258 non_java_threads_do(tc);
259 }
260
261 void Threads::possibly_parallel_threads_do(bool is_par, ThreadClosure* tc) {
262 assert_at_safepoint();
263
264 uintx claim_token = Threads::thread_claim_token();
265 ALL_JAVA_THREADS(p) {
266 if (p->claim_threads_do(is_par, claim_token)) {
267 tc->do_thread(p);
268 }
269 }
270 for (NonJavaThread::Iterator njti; !njti.end(); njti.step()) {
271 Thread* current = njti.current();
272 if (current->claim_threads_do(is_par, claim_token)) {
273 tc->do_thread(current);
274 }
275 }
276 }
277
278 // The system initialization in the library has three phases.
279 //
280 // Phase 1: java.lang.System class initialization
281 // java.lang.System is a primordial class loaded and initialized
282 // by the VM early during startup. java.lang.System.<clinit>
283 // only does registerNatives and keeps the rest of the class
284 // initialization work later until thread initialization completes.
285 //
286 // System.initPhase1 initializes the system properties, the static
287 // fields in, out, and err. Set up java signal handlers, OS-specific
288 // system settings, and thread group of the main thread.
289 static void call_initPhase1(TRAPS) {
290 Klass* klass = vmClasses::System_klass();
291 JavaValue result(T_VOID);
292 JavaCalls::call_static(&result, klass, vmSymbols::initPhase1_name(),
293 vmSymbols::void_method_signature(), CHECK);
294 }
295
296 // Phase 2. Module system initialization
297 // This will initialize the module system. Only java.base classes
298 // can be loaded until phase 2 completes.
299 //
300 // Call System.initPhase2 after the compiler initialization and jsr292
301 // classes get initialized because module initialization runs a lot of java
302 // code, that for performance reasons, should be compiled. Also, this will
303 // enable the startup code to use lambda and other language features in this
304 // phase and onward.
305 //
306 // After phase 2, The VM will begin search classes from -Xbootclasspath/a.
307 static void call_initPhase2(TRAPS) {
308 TraceTime timer("Initialize module system", TRACETIME_LOG(Info, startuptime));
309
310 Klass* klass = vmClasses::System_klass();
311
312 JavaValue result(T_INT);
313 JavaCallArguments args;
314 args.push_int(DisplayVMOutputToStderr);
315 args.push_int(log_is_enabled(Debug, init)); // print stack trace if exception thrown
316 JavaCalls::call_static(&result, klass, vmSymbols::initPhase2_name(),
317 vmSymbols::boolean_boolean_int_signature(), &args, CHECK);
318 if (result.get_jint() != JNI_OK) {
319 vm_exit_during_initialization(); // no message or exception
320 }
321
322 universe_post_module_init();
323 }
324
325 // Phase 3. final setup - set security manager, system class loader and TCCL
326 //
327 // This will instantiate and set the security manager, set the system class
328 // loader as well as the thread context class loader. The security manager
329 // and system class loader may be a custom class loaded from -Xbootclasspath/a,
330 // other modules or the application's classpath.
331 static void call_initPhase3(TRAPS) {
332 Klass* klass = vmClasses::System_klass();
333 JavaValue result(T_VOID);
334 JavaCalls::call_static(&result, klass, vmSymbols::initPhase3_name(),
335 vmSymbols::void_method_signature(), CHECK);
336 }
337
338 void Threads::initialize_java_lang_classes(JavaThread* main_thread, TRAPS) {
339 TraceTime timer("Initialize java.lang classes", TRACETIME_LOG(Info, startuptime));
340
341 initialize_class(vmSymbols::java_lang_String(), CHECK);
342
343 // Inject CompactStrings value after the static initializers for String ran.
344 java_lang_String::set_compact_strings(CompactStrings);
345
346 // Initialize java_lang.System (needed before creating the thread)
347 initialize_class(vmSymbols::java_lang_System(), CHECK);
348 // The VM creates & returns objects of this class. Make sure it's initialized.
349 initialize_class(vmSymbols::java_lang_Class(), CHECK);
350 initialize_class(vmSymbols::java_lang_ThreadGroup(), CHECK);
351 Handle thread_group = create_initial_thread_group(CHECK);
352 Universe::set_main_thread_group(thread_group());
353 initialize_class(vmSymbols::java_lang_Thread(), CHECK);
354 create_initial_thread(thread_group, main_thread, CHECK);
355
356 // The VM creates objects of this class.
357 initialize_class(vmSymbols::java_lang_Module(), CHECK);
358
359 #ifdef ASSERT
360 InstanceKlass *k = vmClasses::UnsafeConstants_klass();
361 assert(k->is_not_initialized(), "UnsafeConstants should not already be initialized");
362 #endif
363
364 // initialize the hardware-specific constants needed by Unsafe
365 initialize_class(vmSymbols::jdk_internal_misc_UnsafeConstants(), CHECK);
366 jdk_internal_misc_UnsafeConstants::set_unsafe_constants();
367
368 // The VM preresolves methods to these classes. Make sure that they get initialized
369 initialize_class(vmSymbols::java_lang_reflect_Method(), CHECK);
370 initialize_class(vmSymbols::java_lang_ref_Finalizer(), CHECK);
371
372 // Phase 1 of the system initialization in the library, java.lang.System class initialization
373 call_initPhase1(CHECK);
374
375 // Get the Java runtime name, version, and vendor info after java.lang.System is initialized.
376 // Some values are actually configure-time constants but some can be set via the jlink tool and
377 // so must be read dynamically. We treat them all the same.
378 InstanceKlass* ik = SystemDictionary::find_instance_klass(THREAD, vmSymbols::java_lang_VersionProps(),
379 Handle(), Handle());
380 {
381 ResourceMark rm(main_thread);
382 JDK_Version::set_java_version(get_java_version_info(ik, vmSymbols::java_version_name()));
383
384 JDK_Version::set_runtime_name(get_java_version_info(ik, vmSymbols::java_runtime_name_name()));
385
386 JDK_Version::set_runtime_version(get_java_version_info(ik, vmSymbols::java_runtime_version_name()));
387
388 JDK_Version::set_runtime_vendor_version(get_java_version_info(ik, vmSymbols::java_runtime_vendor_version_name()));
389
390 JDK_Version::set_runtime_vendor_vm_bug_url(get_java_version_info(ik, vmSymbols::java_runtime_vendor_vm_bug_url_name()));
391 }
392
393 // an instance of OutOfMemory exception has been allocated earlier
394 initialize_class(vmSymbols::java_lang_OutOfMemoryError(), CHECK);
395 initialize_class(vmSymbols::java_lang_NullPointerException(), CHECK);
396 initialize_class(vmSymbols::java_lang_ClassCastException(), CHECK);
397 initialize_class(vmSymbols::java_lang_ArrayStoreException(), CHECK);
398 initialize_class(vmSymbols::java_lang_ArithmeticException(), CHECK);
399 initialize_class(vmSymbols::java_lang_StackOverflowError(), CHECK);
400 initialize_class(vmSymbols::java_lang_IllegalMonitorStateException(), CHECK);
401 initialize_class(vmSymbols::java_lang_IllegalArgumentException(), CHECK);
402 }
403
404 void Threads::initialize_jsr292_core_classes(TRAPS) {
405 TraceTime timer("Initialize java.lang.invoke classes", TRACETIME_LOG(Info, startuptime));
406
407 initialize_class(vmSymbols::java_lang_invoke_MethodHandle(), CHECK);
408 initialize_class(vmSymbols::java_lang_invoke_ResolvedMethodName(), CHECK);
409 initialize_class(vmSymbols::java_lang_invoke_MemberName(), CHECK);
410 initialize_class(vmSymbols::java_lang_invoke_MethodHandleNatives(), CHECK);
411 }
412
413 jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) {
414 extern void JDK_Version_init();
415
416 // Preinitialize version info.
417 VM_Version::early_initialize();
418
419 // Check version
420 if (!is_supported_jni_version(args->version)) return JNI_EVERSION;
421
422 // Initialize library-based TLS
423 ThreadLocalStorage::init();
424
425 // Initialize the output stream module
426 ostream_init();
427
428 // Process java launcher properties.
429 Arguments::process_sun_java_launcher_properties(args);
430
431 // Initialize the os module
432 os::init();
433
434 MACOS_AARCH64_ONLY(os::current_thread_enable_wx(WXWrite));
435
436 // Record VM creation timing statistics
437 TraceVmCreationTime create_vm_timer;
438 create_vm_timer.start();
439
440 // Initialize system properties.
441 Arguments::init_system_properties();
442
443 // So that JDK version can be used as a discriminator when parsing arguments
444 JDK_Version_init();
445
446 // Update/Initialize System properties after JDK version number is known
447 Arguments::init_version_specific_system_properties();
448
449 // Make sure to initialize log configuration *before* parsing arguments
450 LogConfiguration::initialize(create_vm_timer.begin_time());
451
452 // Parse arguments
453 // Note: this internally calls os::init_container_support()
454 jint parse_result = Arguments::parse(args);
455 if (parse_result != JNI_OK) return parse_result;
456
457 // Initialize NMT right after argument parsing to keep the pre-NMT-init window small.
458 MemTracker::initialize();
459
460 os::init_before_ergo();
461
462 jint ergo_result = Arguments::apply_ergo();
463 if (ergo_result != JNI_OK) return ergo_result;
464
465 // Final check of all ranges after ergonomics which may change values.
466 if (!JVMFlagLimit::check_all_ranges()) {
467 return JNI_EINVAL;
468 }
469
470 // Final check of all 'AfterErgo' constraints after ergonomics which may change values.
471 bool constraint_result = JVMFlagLimit::check_all_constraints(JVMFlagConstraintPhase::AfterErgo);
472 if (!constraint_result) {
473 return JNI_EINVAL;
474 }
475
476 if (PauseAtStartup) {
477 os::pause();
478 }
479
480 HOTSPOT_VM_INIT_BEGIN();
481
482 // Timing (must come after argument parsing)
483 TraceTime timer("Create VM", TRACETIME_LOG(Info, startuptime));
484
485 // Initialize the os module after parsing the args
486 jint os_init_2_result = os::init_2();
487 if (os_init_2_result != JNI_OK) return os_init_2_result;
488
489 #ifdef CAN_SHOW_REGISTERS_ON_ASSERT
490 // Initialize assert poison page mechanism.
491 if (ShowRegistersOnAssert) {
492 initialize_assert_poison();
493 }
494 #endif // CAN_SHOW_REGISTERS_ON_ASSERT
495
496 SafepointMechanism::initialize();
497
498 jint adjust_after_os_result = Arguments::adjust_after_os();
499 if (adjust_after_os_result != JNI_OK) return adjust_after_os_result;
500
501 // Initialize output stream logging
502 ostream_init_log();
503
504 // Should happen before any agent attaches and pokes into vmStructs
505 #if INCLUDE_VM_STRUCTS
506 if (UseCompactObjectHeaders) {
507 VMStructs::compact_headers_overrides();
508 }
509 #endif
510
511 // Launch -agentlib/-agentpath and converted -Xrun agents
512 JvmtiAgentList::load_agents();
513
514 // Initialize Threads state
515 _number_of_threads = 0;
516 _number_of_non_daemon_threads = 0;
517
518 // Initialize global data structures and create system classes in heap
519 vm_init_globals();
520
521 #if INCLUDE_JVMCI
522 if (JVMCICounterSize > 0) {
523 JavaThread::_jvmci_old_thread_counters = NEW_C_HEAP_ARRAY(jlong, JVMCICounterSize, mtJVMCI);
524 memset(JavaThread::_jvmci_old_thread_counters, 0, sizeof(jlong) * JVMCICounterSize);
525 } else {
526 JavaThread::_jvmci_old_thread_counters = nullptr;
527 }
528 #endif // INCLUDE_JVMCI
529
530 // Initialize OopStorage for threadObj
531 JavaThread::_thread_oop_storage = OopStorageSet::create_strong("Thread OopStorage", mtThread);
532
533 // Attach the main thread to this os thread
534 JavaThread* main_thread = new JavaThread();
535 main_thread->set_thread_state(_thread_in_vm);
536 main_thread->initialize_thread_current();
537 // must do this before set_active_handles
538 main_thread->record_stack_base_and_size();
539 main_thread->register_thread_stack_with_NMT();
540 main_thread->set_active_handles(JNIHandleBlock::allocate_block());
541 MACOS_AARCH64_ONLY(main_thread->init_wx());
542
543 if (!main_thread->set_as_starting_thread()) {
544 vm_shutdown_during_initialization(
545 "Failed necessary internal allocation. Out of swap space");
546 main_thread->smr_delete();
547 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
548 return JNI_ENOMEM;
549 }
550
551 // Enable guard page *after* os::create_main_thread(), otherwise it would
552 // crash Linux VM, see notes in os_linux.cpp.
553 main_thread->stack_overflow_state()->create_stack_guard_pages();
554
555 // Initialize Java-Level synchronization subsystem
556 ObjectMonitor::Initialize();
557 ObjectSynchronizer::initialize();
558
559 // Initialize global modules
560 jint status = init_globals();
561 if (status != JNI_OK) {
562 main_thread->smr_delete();
563 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
564 return status;
565 }
566
567 // Create WatcherThread as soon as we can since we need it in case
568 // of hangs during error reporting.
569 WatcherThread::start();
570
571 // Add main_thread to threads list to finish barrier setup with
572 // on_thread_attach. Should be before starting to build Java objects in
573 // init_globals2, which invokes barriers.
574 {
575 MutexLocker mu(Threads_lock);
576 Threads::add(main_thread);
577 }
578
579 status = init_globals2();
580 if (status != JNI_OK) {
581 Threads::remove(main_thread, false);
582 // It is possible that we managed to fully initialize Universe but have then
583 // failed by throwing an exception. In that case our caller JNI_CreateJavaVM
584 // will want to report it, so we can't delete the main thread.
585 if (!main_thread->has_pending_exception()) {
586 main_thread->smr_delete();
587 }
588 *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
589 return status;
590 }
591
592 JFR_ONLY(Jfr::on_create_vm_1();)
593
594 // Should be done after the heap is fully created
595 main_thread->cache_global_variables();
596
597 // Any JVMTI raw monitors entered in onload will transition into
598 // real raw monitor. VM is setup enough here for raw monitor enter.
599 JvmtiExport::transition_pending_onload_raw_monitors();
600
601 // Create the VMThread
602 { TraceTime timer("Start VMThread", TRACETIME_LOG(Info, startuptime));
603
604 VMThread::create();
605 VMThread* vmthread = VMThread::vm_thread();
606
607 if (!os::create_thread(vmthread, os::vm_thread)) {
608 vm_exit_during_initialization("Cannot create VM thread. "
609 "Out of system resources.");
610 }
611
612 // Wait for the VM thread to become ready, and VMThread::run to initialize
613 // Monitors can have spurious returns, must always check another state flag
614 {
615 MonitorLocker ml(Notify_lock);
616 os::start_thread(vmthread);
617 while (!vmthread->is_running()) {
618 ml.wait();
619 }
620 }
621 }
622
623 assert(Universe::is_fully_initialized(), "not initialized");
624 if (VerifyDuringStartup) {
625 // Make sure we're starting with a clean slate.
626 VM_Verify verify_op;
627 VMThread::execute(&verify_op);
628 }
629
630 // We need this to update the java.vm.info property in case any flags used
631 // to initially define it have been changed. This is needed for both CDS
632 // since UseSharedSpaces may be changed after java.vm.info
633 // is initially computed. See Abstract_VM_Version::vm_info_string().
634 // This update must happen before we initialize the java classes, but
635 // after any initialization logic that might modify the flags.
636 Arguments::update_vm_info_property(VM_Version::vm_info_string());
637
638 JavaThread* THREAD = JavaThread::current(); // For exception macros.
639 HandleMark hm(THREAD);
640
641 // Always call even when there are not JVMTI environments yet, since environments
642 // may be attached late and JVMTI must track phases of VM execution
643 JvmtiExport::enter_early_start_phase();
644
645 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
646 JvmtiExport::post_early_vm_start();
647
648 // Launch -Xrun agents early if EagerXrunInit is set
649 if (EagerXrunInit) {
650 JvmtiAgentList::load_xrun_agents();
651 }
652
653 initialize_java_lang_classes(main_thread, CHECK_JNI_ERR);
654
655 quicken_jni_functions();
656
657 // No more stub generation allowed after that point.
658 StubCodeDesc::freeze();
659
660 // Set flag that basic initialization has completed. Used by exceptions and various
661 // debug stuff, that does not work until all basic classes have been initialized.
662 set_init_completed();
663
664 LogConfiguration::post_initialize();
665 Metaspace::post_initialize();
666 MutexLocker::post_initialize();
667
668 HOTSPOT_VM_INIT_END();
669
670 // record VM initialization completion time
671 #if INCLUDE_MANAGEMENT
672 Management::record_vm_init_completed();
673 #endif // INCLUDE_MANAGEMENT
674
675 log_info(os)("Initialized VM with process ID %d", os::current_process_id());
676
677 // Signal Dispatcher needs to be started before VMInit event is posted
678 os::initialize_jdk_signal_support(CHECK_JNI_ERR);
679
680 // Start Attach Listener if +StartAttachListener or it can't be started lazily
681 if (!DisableAttachMechanism) {
682 AttachListener::vm_start();
683 if (StartAttachListener || AttachListener::init_at_startup()) {
684 AttachListener::init();
685 }
686 }
687
688 // Launch -Xrun agents if EagerXrunInit is not set.
689 if (!EagerXrunInit) {
690 JvmtiAgentList::load_xrun_agents();
691 }
692
693 Arena::start_chunk_pool_cleaner_task();
694
695 // Start the service thread
696 // The service thread enqueues JVMTI deferred events and does various hashtable
697 // and other cleanups. Needs to start before the compilers start posting events.
698 ServiceThread::initialize();
699
700 // Start the monitor deflation thread:
701 MonitorDeflationThread::initialize();
702
703 // initialize compiler(s)
704 #if defined(COMPILER1) || COMPILER2_OR_JVMCI
705 #if INCLUDE_JVMCI
706 bool force_JVMCI_intialization = false;
707 if (EnableJVMCI) {
708 // Initialize JVMCI eagerly when it is explicitly requested.
709 // Or when JVMCILibDumpJNIConfig or JVMCIPrintProperties is enabled.
710 force_JVMCI_intialization = EagerJVMCI || JVMCIPrintProperties || JVMCILibDumpJNIConfig;
711
712 if (!force_JVMCI_intialization) {
713 // 8145270: Force initialization of JVMCI runtime otherwise requests for blocking
714 // compilations via JVMCI will not actually block until JVMCI is initialized.
715 force_JVMCI_intialization = UseJVMCICompiler && (!UseInterpreter || !BackgroundCompilation);
716 }
717 }
718 #endif
719 CompileBroker::compilation_init_phase1(CHECK_JNI_ERR);
720 // Postpone completion of compiler initialization to after JVMCI
721 // is initialized to avoid timeouts of blocking compilations.
722 if (JVMCI_ONLY(!force_JVMCI_intialization) NOT_JVMCI(true)) {
723 CompileBroker::compilation_init_phase2();
724 }
725 #endif
726
727 // Start string deduplication thread if requested.
728 if (StringDedup::is_enabled()) {
729 StringDedup::start();
730 }
731
732 // Pre-initialize some JSR292 core classes to avoid deadlock during class loading.
733 // It is done after compilers are initialized, because otherwise compilations of
734 // signature polymorphic MH intrinsics can be missed
735 // (see SystemDictionary::find_method_handle_intrinsic).
736 initialize_jsr292_core_classes(CHECK_JNI_ERR);
737
738 // This will initialize the module system. Only java.base classes can be
739 // loaded until phase 2 completes
740 call_initPhase2(CHECK_JNI_ERR);
741
742 JFR_ONLY(Jfr::on_create_vm_2();)
743
744 // Always call even when there are not JVMTI environments yet, since environments
745 // may be attached late and JVMTI must track phases of VM execution
746 JvmtiExport::enter_start_phase();
747
748 // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
749 JvmtiExport::post_vm_start();
750
751 // Final system initialization including security manager and system class loader
752 call_initPhase3(CHECK_JNI_ERR);
753
754 // cache the system and platform class loaders
755 SystemDictionary::compute_java_loaders(CHECK_JNI_ERR);
756
757 #if INCLUDE_CDS
758 // capture the module path info from the ModuleEntryTable
759 ClassLoader::initialize_module_path(THREAD);
760 if (HAS_PENDING_EXCEPTION) {
761 java_lang_Throwable::print(PENDING_EXCEPTION, tty);
762 vm_exit_during_initialization("ClassLoader::initialize_module_path() failed unexpectedly");
763 }
764 #endif
765
766 #if INCLUDE_JVMCI
767 if (force_JVMCI_intialization) {
768 JVMCI::initialize_compiler(CHECK_JNI_ERR);
769 CompileBroker::compilation_init_phase2();
770 }
771 #endif
772
773 if (NativeHeapTrimmer::enabled()) {
774 NativeHeapTrimmer::initialize();
775 }
776
777 // Always call even when there are not JVMTI environments yet, since environments
778 // may be attached late and JVMTI must track phases of VM execution
779 JvmtiExport::enter_live_phase();
780
781 // Make perfmemory accessible
782 PerfMemory::set_accessible(true);
783
784 // Notify JVMTI agents that VM initialization is complete - nop if no agents.
785 JvmtiExport::post_vm_initialized();
786
787 JFR_ONLY(Jfr::on_create_vm_3();)
788
789 #if INCLUDE_MANAGEMENT
790 Management::initialize(THREAD);
791
792 if (HAS_PENDING_EXCEPTION) {
793 // management agent fails to start possibly due to
794 // configuration problem and is responsible for printing
795 // stack trace if appropriate. Simply exit VM.
796 vm_exit(1);
797 }
798 #endif // INCLUDE_MANAGEMENT
799
800 StatSampler::engage();
801 if (CheckJNICalls) JniPeriodicChecker::engage();
802
803 #if INCLUDE_RTM_OPT
804 RTMLockingCounters::init();
805 #endif
806
807 call_postVMInitHook(THREAD);
808 // The Java side of PostVMInitHook.run must deal with all
809 // exceptions and provide means of diagnosis.
810 if (HAS_PENDING_EXCEPTION) {
811 CLEAR_PENDING_EXCEPTION;
812 }
813
814 // Let WatcherThread run all registered periodic tasks now.
815 // NOTE: All PeriodicTasks should be registered by now. If they
816 // aren't, late joiners might appear to start slowly (we might
817 // take a while to process their first tick).
818 WatcherThread::run_all_tasks();
819
820 create_vm_timer.end();
821 #ifdef ASSERT
822 _vm_complete = true;
823 #endif
824
825 if (DumpSharedSpaces) {
826 MetaspaceShared::preload_and_dump();
827 }
828
829 return JNI_OK;
830 }
831
832 // Threads::destroy_vm() is normally called from jni_DestroyJavaVM() when
833 // the program falls off the end of main(). Another VM exit path is through
834 // vm_exit() when the program calls System.exit() to return a value or when
835 // there is a serious error in VM. The two shutdown paths are not exactly
836 // the same, but they share Shutdown.shutdown() at Java level and before_exit()
837 // and VM_Exit op at VM level.
838 //
839 // Shutdown sequence:
840 // + Shutdown native memory tracking if it is on
841 // + Wait until we are the last non-daemon thread to execute
842 // <-- every thing is still working at this moment -->
843 // + Call java.lang.Shutdown.shutdown(), which will invoke Java level
844 // shutdown hooks
845 // + Call before_exit(), prepare for VM exit
846 // > run VM level shutdown hooks (they are registered through JVM_OnExit(),
847 // currently the only user of this mechanism is File.deleteOnExit())
848 // > stop StatSampler, watcher thread,
849 // post thread end and vm death events to JVMTI,
850 // stop signal thread
851 // + Call JavaThread::exit(), it will:
852 // > release JNI handle blocks, remove stack guard pages
853 // > remove this thread from Threads list
854 // <-- no more Java code from this thread after this point -->
855 // + Stop VM thread, it will bring the remaining VM to a safepoint and stop
856 // the compiler threads at safepoint
857 // <-- do not use anything that could get blocked by Safepoint -->
858 // + Disable tracing at JNI/JVM barriers
859 // + Set _vm_exited flag for threads that are still running native code
860 // + Call exit_globals()
861 // > deletes tty
862 // > deletes PerfMemory resources
863 // + Delete this thread
864 // + Return to caller
865
866 void Threads::destroy_vm() {
867 JavaThread* thread = JavaThread::current();
868
869 #ifdef ASSERT
870 _vm_complete = false;
871 #endif
872 // Wait until we are the last non-daemon thread to execute, or
873 // if we are a daemon then wait until the last non-daemon thread has
874 // executed.
875 bool daemon = java_lang_Thread::is_daemon(thread->threadObj());
876 int expected = daemon ? 0 : 1;
877 {
878 MonitorLocker nu(Threads_lock);
879 while (Threads::number_of_non_daemon_threads() > expected)
880 // This wait should make safepoint checks, wait without a timeout.
881 nu.wait(0);
882 }
883
884 EventShutdown e;
885 if (e.should_commit()) {
886 e.set_reason("No remaining non-daemon Java threads");
887 e.commit();
888 }
889
890 // Hang forever on exit if we are reporting an error.
891 if (ShowMessageBoxOnError && VMError::is_error_reported()) {
892 os::infinite_sleep();
893 }
894 os::wait_for_keypress_at_exit();
895
896 // run Java level shutdown hooks
897 thread->invoke_shutdown_hooks();
898
899 before_exit(thread);
900
901 thread->exit(true);
902
903 // We are no longer on the main thread list but could still be in a
904 // secondary list where another thread may try to interact with us.
905 // So wait until all such interactions are complete before we bring
906 // the VM to the termination safepoint. Normally this would be done
907 // using thread->smr_delete() below where we delete the thread, but
908 // we can't call that after the termination safepoint is active as
909 // we will deadlock on the Threads_lock. Once all interactions are
910 // complete it is safe to directly delete the thread at any time.
911 ThreadsSMRSupport::wait_until_not_protected(thread);
912
913 // Stop VM thread.
914 {
915 // 4945125 The vm thread comes to a safepoint during exit.
916 // GC vm_operations can get caught at the safepoint, and the
917 // heap is unparseable if they are caught. Grab the Heap_lock
918 // to prevent this. The GC vm_operations will not be able to
919 // queue until after the vm thread is dead. After this point,
920 // we'll never emerge out of the safepoint before the VM exits.
921 // Assert that the thread is terminated so that acquiring the
922 // Heap_lock doesn't cause the terminated thread to participate in
923 // the safepoint protocol.
924
925 assert(thread->is_terminated(), "must be terminated here");
926 MutexLocker ml(Heap_lock);
927
928 VMThread::wait_for_vm_thread_exit();
929 assert(SafepointSynchronize::is_at_safepoint(), "VM thread should exit at Safepoint");
930 VMThread::destroy();
931 }
932
933 // Now, all Java threads are gone except daemon threads. Daemon threads
934 // running Java code or in VM are stopped by the Safepoint. However,
935 // daemon threads executing native code are still running. But they
936 // will be stopped at native=>Java/VM barriers. Note that we can't
937 // simply kill or suspend them, as it is inherently deadlock-prone.
938
939 VM_Exit::set_vm_exited();
940
941 // Clean up ideal graph printers after the VMThread has started
942 // the final safepoint which will block all the Compiler threads.
943 // Note that this Thread has already logically exited so the
944 // clean_up() function's use of a JavaThreadIteratorWithHandle
945 // would be a problem except set_vm_exited() has remembered the
946 // shutdown thread which is granted a policy exception.
947 #if defined(COMPILER2) && !defined(PRODUCT)
948 IdealGraphPrinter::clean_up();
949 #endif
950
951 notify_vm_shutdown();
952
953 // exit_globals() will delete tty
954 exit_globals();
955
956 // Deleting the shutdown thread here is safe. See comment on
957 // wait_until_not_protected() above.
958 delete thread;
959
960 #if INCLUDE_JVMCI
961 if (JVMCICounterSize > 0) {
962 FREE_C_HEAP_ARRAY(jlong, JavaThread::_jvmci_old_thread_counters);
963 }
964 #endif
965
966 LogConfiguration::finalize();
967 }
968
969
970 jboolean Threads::is_supported_jni_version_including_1_1(jint version) {
971 if (version == JNI_VERSION_1_1) return JNI_TRUE;
972 return is_supported_jni_version(version);
973 }
974
975
976 jboolean Threads::is_supported_jni_version(jint version) {
977 if (version == JNI_VERSION_1_2) return JNI_TRUE;
978 if (version == JNI_VERSION_1_4) return JNI_TRUE;
979 if (version == JNI_VERSION_1_6) return JNI_TRUE;
980 if (version == JNI_VERSION_1_8) return JNI_TRUE;
981 if (version == JNI_VERSION_9) return JNI_TRUE;
982 if (version == JNI_VERSION_10) return JNI_TRUE;
983 if (version == JNI_VERSION_19) return JNI_TRUE;
984 if (version == JNI_VERSION_20) return JNI_TRUE;
985 if (version == JNI_VERSION_21) return JNI_TRUE;
986 return JNI_FALSE;
987 }
988
989 void Threads::add(JavaThread* p, bool force_daemon) {
990 // The threads lock must be owned at this point
991 assert(Threads_lock->owned_by_self(), "must have threads lock");
992
993 BarrierSet::barrier_set()->on_thread_attach(p);
994
995 // Once a JavaThread is added to the Threads list, smr_delete() has
996 // to be used to delete it. Otherwise we can just delete it directly.
997 p->set_on_thread_list();
998
999 _number_of_threads++;
1000 oop threadObj = p->threadObj();
1001 bool daemon = true;
1002 // Bootstrapping problem: threadObj can be null for initial
1003 // JavaThread (or for threads attached via JNI)
1004 if (!force_daemon &&
1005 (threadObj == nullptr || !java_lang_Thread::is_daemon(threadObj))) {
1006 _number_of_non_daemon_threads++;
1007 daemon = false;
1008 }
1009
1010 ThreadService::add_thread(p, daemon);
1011
1012 // Maintain fast thread list
1013 ThreadsSMRSupport::add_thread(p);
1014
1015 // Increase the ObjectMonitor ceiling for the new thread.
1016 ObjectSynchronizer::inc_in_use_list_ceiling();
1017
1018 // Possible GC point.
1019 Events::log(p, "Thread added: " INTPTR_FORMAT, p2i(p));
1020
1021 // Make new thread known to active EscapeBarrier
1022 EscapeBarrier::thread_added(p);
1023 }
1024
1025 void Threads::remove(JavaThread* p, bool is_daemon) {
1026 // Extra scope needed for Thread_lock, so we can check
1027 // that we do not remove thread without safepoint code notice
1028 { MonitorLocker ml(Threads_lock);
1029
1030 if (ThreadIdTable::is_initialized()) {
1031 // This cleanup must be done before the current thread's GC barrier
1032 // is detached since we need to touch the threadObj oop.
1033 jlong tid = SharedRuntime::get_java_tid(p);
1034 ThreadIdTable::remove_thread(tid);
1035 }
1036
1037 // BarrierSet state must be destroyed after the last thread transition
1038 // before the thread terminates. Thread transitions result in calls to
1039 // StackWatermarkSet::on_safepoint(), which performs GC processing,
1040 // requiring the GC state to be alive.
1041 BarrierSet::barrier_set()->on_thread_detach(p);
1042 if (p->is_exiting()) {
1043 // If we got here via JavaThread::exit(), then we remember that the
1044 // thread's GC barrier has been detached. We don't do this when we get
1045 // here from another path, e.g., cleanup_failed_attach_current_thread().
1046 p->set_terminated(JavaThread::_thread_gc_barrier_detached);
1047 }
1048
1049 assert(ThreadsSMRSupport::get_java_thread_list()->includes(p), "p must be present");
1050
1051 // Maintain fast thread list
1052 ThreadsSMRSupport::remove_thread(p);
1053
1054 _number_of_threads--;
1055 if (!is_daemon) {
1056 _number_of_non_daemon_threads--;
1057
1058 // If this is the last non-daemon thread then we need to do
1059 // a notify on the Threads_lock so a thread waiting
1060 // on destroy_vm will wake up. But that thread could be a daemon
1061 // or non-daemon, so we notify for both the 0 and 1 case.
1062 if (number_of_non_daemon_threads() <= 1) {
1063 ml.notify_all();
1064 }
1065 }
1066 ThreadService::remove_thread(p, is_daemon);
1067
1068 // Make sure that safepoint code disregard this thread. This is needed since
1069 // the thread might mess around with locks after this point. This can cause it
1070 // to do callbacks into the safepoint code. However, the safepoint code is not aware
1071 // of this thread since it is removed from the queue.
1072 p->set_terminated(JavaThread::_thread_terminated);
1073
1074 // Notify threads waiting in EscapeBarriers
1075 EscapeBarrier::thread_removed(p);
1076 } // unlock Threads_lock
1077
1078 // Reduce the ObjectMonitor ceiling for the exiting thread.
1079 ObjectSynchronizer::dec_in_use_list_ceiling();
1080
1081 // Since Events::log uses a lock, we grab it outside the Threads_lock
1082 Events::log(p, "Thread exited: " INTPTR_FORMAT, p2i(p));
1083 }
1084
1085 // Operations on the Threads list for GC. These are not explicitly locked,
1086 // but the garbage collector must provide a safe context for them to run.
1087 // In particular, these things should never be called when the Threads_lock
1088 // is held by some other thread. (Note: the Safepoint abstraction also
1089 // uses the Threads_lock to guarantee this property. It also makes sure that
1090 // all threads gets blocked when exiting or starting).
1091
1092 void Threads::oops_do(OopClosure* f, CodeBlobClosure* cf) {
1093 ALL_JAVA_THREADS(p) {
1094 p->oops_do(f, cf);
1095 }
1096 VMThread::vm_thread()->oops_do(f, cf);
1097 }
1098
1099 void Threads::change_thread_claim_token() {
1100 if (++_thread_claim_token == 0) {
1101 // On overflow of the token counter, there is a risk of future
1102 // collisions between a new global token value and a stale token
1103 // for a thread, because not all iterations visit all threads.
1104 // (Though it's pretty much a theoretical concern for non-trivial
1105 // token counter sizes.) To deal with the possibility, reset all
1106 // the thread tokens to zero on global token overflow.
1107 struct ResetClaims : public ThreadClosure {
1108 virtual void do_thread(Thread* t) {
1109 t->claim_threads_do(false, 0);
1110 }
1111 } reset_claims;
1112 Threads::threads_do(&reset_claims);
1113 // On overflow, update the global token to non-zero, to
1114 // avoid the special "never claimed" initial thread value.
1115 _thread_claim_token = 1;
1116 }
1117 }
1118
1119 #ifdef ASSERT
1120 void assert_thread_claimed(const char* kind, Thread* t, uintx expected) {
1121 const uintx token = t->threads_do_token();
1122 assert(token == expected,
1123 "%s " PTR_FORMAT " has incorrect value " UINTX_FORMAT " != "
1124 UINTX_FORMAT, kind, p2i(t), token, expected);
1125 }
1126
1127 void Threads::assert_all_threads_claimed() {
1128 ALL_JAVA_THREADS(p) {
1129 assert_thread_claimed("JavaThread", p, _thread_claim_token);
1130 }
1131
1132 struct NJTClaimedVerifierClosure : public ThreadClosure {
1133 uintx _thread_claim_token;
1134
1135 NJTClaimedVerifierClosure(uintx thread_claim_token) : ThreadClosure(), _thread_claim_token(thread_claim_token) { }
1136
1137 virtual void do_thread(Thread* thread) override {
1138 assert_thread_claimed("Non-JavaThread", VMThread::vm_thread(), _thread_claim_token);
1139 }
1140 } tc(_thread_claim_token);
1141
1142 non_java_threads_do(&tc);
1143 }
1144 #endif // ASSERT
1145
1146 class ParallelOopsDoThreadClosure : public ThreadClosure {
1147 private:
1148 OopClosure* _f;
1149 CodeBlobClosure* _cf;
1150 public:
1151 ParallelOopsDoThreadClosure(OopClosure* f, CodeBlobClosure* cf) : _f(f), _cf(cf) {}
1152 void do_thread(Thread* t) {
1153 t->oops_do(_f, _cf);
1154 }
1155 };
1156
1157 void Threads::possibly_parallel_oops_do(bool is_par, OopClosure* f, CodeBlobClosure* cf) {
1158 ParallelOopsDoThreadClosure tc(f, cf);
1159 possibly_parallel_threads_do(is_par, &tc);
1160 }
1161
1162 void Threads::metadata_do(MetadataClosure* f) {
1163 ALL_JAVA_THREADS(p) {
1164 p->metadata_do(f);
1165 }
1166 }
1167
1168 class ThreadHandlesClosure : public ThreadClosure {
1169 void (*_f)(Metadata*);
1170 public:
1171 ThreadHandlesClosure(void f(Metadata*)) : _f(f) {}
1172 virtual void do_thread(Thread* thread) {
1173 thread->metadata_handles_do(_f);
1174 }
1175 };
1176
1177 void Threads::metadata_handles_do(void f(Metadata*)) {
1178 // Only walk the Handles in Thread.
1179 ThreadHandlesClosure handles_closure(f);
1180 threads_do(&handles_closure);
1181 }
1182
1183 // Get count Java threads that are waiting to enter the specified monitor.
1184 GrowableArray<JavaThread*>* Threads::get_pending_threads(ThreadsList * t_list,
1185 int count,
1186 address monitor) {
1187 GrowableArray<JavaThread*>* result = new GrowableArray<JavaThread*>(count);
1188
1189 int i = 0;
1190 for (JavaThread* p : *t_list) {
1191 if (!p->can_call_java()) continue;
1192
1193 // The first stage of async deflation does not affect any field
1194 // used by this comparison so the ObjectMonitor* is usable here.
1195 address pending = (address)p->current_pending_monitor();
1196 if (pending == monitor) { // found a match
1197 if (i < count) result->append(p); // save the first count matches
1198 i++;
1199 }
1200 }
1201
1202 return result;
1203 }
1204
1205
1206 JavaThread *Threads::owning_thread_from_monitor_owner(ThreadsList * t_list,
1207 address owner) {
1208 assert(LockingMode != LM_LIGHTWEIGHT, "Not with new lightweight locking");
1209 // null owner means not locked so we can skip the search
1210 if (owner == nullptr) return nullptr;
1211
1212 for (JavaThread* p : *t_list) {
1213 // first, see if owner is the address of a Java thread
1214 if (owner == (address)p) return p;
1215 }
1216
1217 // Cannot assert on lack of success here since this function may be
1218 // used by code that is trying to report useful problem information
1219 // like deadlock detection.
1220 if (LockingMode == LM_MONITOR) return nullptr;
1221
1222 // If we didn't find a matching Java thread and we didn't force use of
1223 // heavyweight monitors, then the owner is the stack address of the
1224 // Lock Word in the owning Java thread's stack.
1225 //
1226 JavaThread* the_owner = nullptr;
1227 for (JavaThread* q : *t_list) {
1228 if (q->is_lock_owned(owner)) {
1229 the_owner = q;
1230 break;
1231 }
1232 }
1233
1234 // cannot assert on lack of success here; see above comment
1235 return the_owner;
1236 }
1237
1238 JavaThread* Threads::owning_thread_from_object(ThreadsList * t_list, oop obj) {
1239 assert(LockingMode == LM_LIGHTWEIGHT, "Only with new lightweight locking");
1240 for (JavaThread* q : *t_list) {
1241 if (q->lock_stack().contains(obj)) {
1242 return q;
1243 }
1244 }
1245 return nullptr;
1246 }
1247
1248 JavaThread* Threads::owning_thread_from_monitor(ThreadsList* t_list, ObjectMonitor* monitor) {
1249 if (LockingMode == LM_LIGHTWEIGHT) {
1250 if (monitor->is_owner_anonymous()) {
1251 return owning_thread_from_object(t_list, monitor->object());
1252 } else {
1253 Thread* owner = reinterpret_cast<Thread*>(monitor->owner());
1254 assert(owner == nullptr || owner->is_Java_thread(), "only JavaThreads own monitors");
1255 return reinterpret_cast<JavaThread*>(owner);
1256 }
1257 } else {
1258 address owner = (address)monitor->owner();
1259 return owning_thread_from_monitor_owner(t_list, owner);
1260 }
1261 }
1262
1263 class PrintOnClosure : public ThreadClosure {
1264 private:
1265 outputStream* _st;
1266
1267 public:
1268 PrintOnClosure(outputStream* st) :
1269 _st(st) {}
1270
1271 virtual void do_thread(Thread* thread) {
1272 if (thread != nullptr) {
1273 thread->print_on(_st);
1274 _st->cr();
1275 }
1276 }
1277 };
1278
1279 // Threads::print_on() is called at safepoint by VM_PrintThreads operation.
1280 void Threads::print_on(outputStream* st, bool print_stacks,
1281 bool internal_format, bool print_concurrent_locks,
1282 bool print_extended_info) {
1283 char buf[32];
1284 st->print_raw_cr(os::local_time_string(buf, sizeof(buf)));
1285
1286 st->print_cr("Full thread dump %s (%s %s):",
1287 VM_Version::vm_name(),
1288 VM_Version::vm_release(),
1289 VM_Version::vm_info_string());
1290 st->cr();
1291
1292 #if INCLUDE_SERVICES
1293 // Dump concurrent locks
1294 ConcurrentLocksDump concurrent_locks;
1295 if (print_concurrent_locks) {
1296 concurrent_locks.dump_at_safepoint();
1297 }
1298 #endif // INCLUDE_SERVICES
1299
1300 ThreadsSMRSupport::print_info_on(st);
1301 st->cr();
1302
1303 ALL_JAVA_THREADS(p) {
1304 ResourceMark rm;
1305 p->print_on(st, print_extended_info);
1306 if (print_stacks) {
1307 if (internal_format) {
1308 p->trace_stack();
1309 } else {
1310 p->print_stack_on(st);
1311 }
1312 }
1313 st->cr();
1314 #if INCLUDE_SERVICES
1315 if (print_concurrent_locks) {
1316 concurrent_locks.print_locks_on(p, st);
1317 }
1318 #endif // INCLUDE_SERVICES
1319 }
1320
1321 PrintOnClosure cl(st);
1322 cl.do_thread(VMThread::vm_thread());
1323 Universe::heap()->gc_threads_do(&cl);
1324 cl.do_thread(WatcherThread::watcher_thread());
1325 cl.do_thread(AsyncLogWriter::instance());
1326
1327 st->flush();
1328 }
1329
1330 void Threads::print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
1331 int buflen, bool* found_current) {
1332 if (this_thread != nullptr) {
1333 bool is_current = (current == this_thread);
1334 *found_current = *found_current || is_current;
1335 st->print("%s", is_current ? "=>" : " ");
1336
1337 st->print(PTR_FORMAT, p2i(this_thread));
1338 st->print(" ");
1339 this_thread->print_on_error(st, buf, buflen);
1340 st->cr();
1341 }
1342 }
1343
1344 class PrintOnErrorClosure : public ThreadClosure {
1345 outputStream* _st;
1346 Thread* _current;
1347 char* _buf;
1348 int _buflen;
1349 bool* _found_current;
1350 unsigned _num_printed;
1351 public:
1352 PrintOnErrorClosure(outputStream* st, Thread* current, char* buf,
1353 int buflen, bool* found_current) :
1354 _st(st), _current(current), _buf(buf), _buflen(buflen), _found_current(found_current),
1355 _num_printed(0) {}
1356
1357 virtual void do_thread(Thread* thread) {
1358 _num_printed++;
1359 Threads::print_on_error(thread, _st, _current, _buf, _buflen, _found_current);
1360 }
1361
1362 unsigned num_printed() const { return _num_printed; }
1363 };
1364
1365 // Threads::print_on_error() is called by fatal error handler. It's possible
1366 // that VM is not at safepoint and/or current thread is inside signal handler.
1367 // Don't print stack trace, as the stack may not be walkable. Don't allocate
1368 // memory (even in resource area), it might deadlock the error handler.
1369 void Threads::print_on_error(outputStream* st, Thread* current, char* buf,
1370 int buflen) {
1371 ThreadsSMRSupport::print_info_on(st);
1372 st->cr();
1373
1374 bool found_current = false;
1375 st->print_cr("Java Threads: ( => current thread )");
1376 unsigned num_java = 0;
1377 ALL_JAVA_THREADS(thread) {
1378 print_on_error(thread, st, current, buf, buflen, &found_current);
1379 num_java++;
1380 }
1381 st->print_cr("Total: %u", num_java);
1382 st->cr();
1383
1384 st->print_cr("Other Threads:");
1385 unsigned num_other = ((VMThread::vm_thread() != nullptr) ? 1 : 0) +
1386 ((WatcherThread::watcher_thread() != nullptr) ? 1 : 0) +
1387 ((AsyncLogWriter::instance() != nullptr) ? 1 : 0);
1388 print_on_error(VMThread::vm_thread(), st, current, buf, buflen, &found_current);
1389 print_on_error(WatcherThread::watcher_thread(), st, current, buf, buflen, &found_current);
1390 print_on_error(AsyncLogWriter::instance(), st, current, buf, buflen, &found_current);
1391
1392 if (Universe::heap() != nullptr) {
1393 PrintOnErrorClosure print_closure(st, current, buf, buflen, &found_current);
1394 Universe::heap()->gc_threads_do(&print_closure);
1395 num_other += print_closure.num_printed();
1396 }
1397
1398 if (!found_current) {
1399 st->cr();
1400 st->print("=>" PTR_FORMAT " (exited) ", p2i(current));
1401 current->print_on_error(st, buf, buflen);
1402 num_other++;
1403 st->cr();
1404 }
1405 st->print_cr("Total: %u", num_other);
1406 st->cr();
1407
1408 st->print_cr("Threads with active compile tasks:");
1409 unsigned num = print_threads_compiling(st, buf, buflen);
1410 st->print_cr("Total: %u", num);
1411 }
1412
1413 unsigned Threads::print_threads_compiling(outputStream* st, char* buf, int buflen, bool short_form) {
1414 unsigned num = 0;
1415 ALL_JAVA_THREADS(thread) {
1416 if (thread->is_Compiler_thread()) {
1417 CompilerThread* ct = (CompilerThread*) thread;
1418
1419 // Keep task in local variable for null check.
1420 // ct->_task might be set to null by concurring compiler thread
1421 // because it completed the compilation. The task is never freed,
1422 // though, just returned to a free list.
1423 CompileTask* task = ct->task();
1424 if (task != nullptr) {
1425 thread->print_name_on_error(st, buf, buflen);
1426 st->print(" ");
1427 task->print(st, nullptr, short_form, true);
1428 num++;
1429 }
1430 }
1431 }
1432 return num;
1433 }
1434
1435 void Threads::verify() {
1436 ALL_JAVA_THREADS(p) {
1437 p->verify();
1438 }
1439 VMThread* thread = VMThread::vm_thread();
1440 if (thread != nullptr) thread->verify();
1441 }