1 /* 2 * Copyright (c) 1997, 2025, 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 "cds/dynamicArchive.hpp" 27 #include "ci/ciEnv.hpp" 28 #include "classfile/javaClasses.inline.hpp" 29 #include "classfile/javaThreadStatus.hpp" 30 #include "classfile/systemDictionary.hpp" 31 #include "classfile/vmClasses.hpp" 32 #include "classfile/vmSymbols.hpp" 33 #include "code/codeCache.hpp" 34 #include "code/scopeDesc.hpp" 35 #include "compiler/compilerThread.hpp" 36 #include "compiler/compileTask.hpp" 37 #include "gc/shared/oopStorage.hpp" 38 #include "gc/shared/oopStorageSet.hpp" 39 #include "gc/shared/tlab_globals.hpp" 40 #include "jfr/jfrEvents.hpp" 41 #include "jvm.h" 42 #include "jvmtifiles/jvmtiEnv.hpp" 43 #include "logging/log.hpp" 44 #include "logging/logAsyncWriter.hpp" 45 #include "logging/logStream.hpp" 46 #include "memory/allocation.inline.hpp" 47 #include "memory/iterator.hpp" 48 #include "memory/universe.hpp" 49 #include "oops/access.inline.hpp" 50 #include "oops/instanceKlass.hpp" 51 #include "oops/klass.inline.hpp" 52 #include "oops/oop.inline.hpp" 53 #include "oops/oopHandle.inline.hpp" 54 #include "oops/verifyOopClosure.hpp" 55 #include "prims/jvm_misc.hpp" 56 #include "prims/jvmtiDeferredUpdates.hpp" 57 #include "prims/jvmtiExport.hpp" 58 #include "prims/jvmtiThreadState.inline.hpp" 59 #include "runtime/atomicAccess.hpp" 60 #include "runtime/continuation.hpp" 61 #include "runtime/continuationEntry.inline.hpp" 62 #include "runtime/continuationHelper.inline.hpp" 63 #include "runtime/deoptimization.hpp" 64 #include "runtime/frame.inline.hpp" 65 #include "runtime/handles.inline.hpp" 66 #include "runtime/handshake.hpp" 67 #include "runtime/interfaceSupport.inline.hpp" 68 #include "runtime/java.hpp" 69 #include "runtime/javaCalls.hpp" 70 #include "runtime/javaThread.inline.hpp" 71 #include "runtime/jniHandles.inline.hpp" 72 #include "runtime/lockStack.inline.hpp" 73 #include "runtime/mutexLocker.hpp" 74 #include "runtime/orderAccess.hpp" 75 #include "runtime/os.inline.hpp" 76 #include "runtime/osThread.hpp" 77 #include "runtime/safepoint.hpp" 78 #include "runtime/safepointMechanism.inline.hpp" 79 #include "runtime/safepointVerifiers.hpp" 80 #include "runtime/serviceThread.hpp" 81 #include "runtime/stackFrameStream.inline.hpp" 82 #include "runtime/stackWatermarkSet.hpp" 83 #include "runtime/synchronizer.hpp" 84 #include "runtime/threadIdentifier.hpp" 85 #include "runtime/threadSMR.inline.hpp" 86 #include "runtime/threadStatisticalInfo.hpp" 87 #include "runtime/threadWXSetters.inline.hpp" 88 #include "runtime/timer.hpp" 89 #include "runtime/timerTrace.hpp" 90 #include "runtime/vframe.inline.hpp" 91 #include "runtime/vframe_hp.hpp" 92 #include "runtime/vframeArray.hpp" 93 #include "runtime/vmOperations.hpp" 94 #include "runtime/vmThread.hpp" 95 #include "services/threadService.hpp" 96 #include "utilities/copy.hpp" 97 #include "utilities/defaultStream.hpp" 98 #include "utilities/dtrace.hpp" 99 #include "utilities/events.hpp" 100 #include "utilities/macros.hpp" 101 #include "utilities/nativeStackPrinter.hpp" 102 #include "utilities/preserveException.hpp" 103 #include "utilities/spinYield.hpp" 104 #include "utilities/vmError.hpp" 105 #if INCLUDE_JVMCI 106 #include "jvmci/jvmci.hpp" 107 #include "jvmci/jvmciEnv.hpp" 108 #endif 109 #if INCLUDE_JFR 110 #include "jfr/jfr.hpp" 111 #endif 112 113 // Set by os layer. 114 size_t JavaThread::_stack_size_at_create = 0; 115 116 #ifdef DTRACE_ENABLED 117 118 // Only bother with this argument setup if dtrace is available 119 120 #define HOTSPOT_THREAD_PROBE_start HOTSPOT_THREAD_START 121 #define HOTSPOT_THREAD_PROBE_stop HOTSPOT_THREAD_STOP 122 123 #define DTRACE_THREAD_PROBE(probe, javathread) \ 124 { \ 125 ResourceMark rm(this); \ 126 int len = 0; \ 127 const char* name = (javathread)->name(); \ 128 len = strlen(name); \ 129 HOTSPOT_THREAD_PROBE_##probe(/* probe = start, stop */ \ 130 (char *) name, len, \ 131 java_lang_Thread::thread_id((javathread)->threadObj()), \ 132 (uintptr_t) (javathread)->osthread()->thread_id(), \ 133 java_lang_Thread::is_daemon((javathread)->threadObj())); \ 134 } 135 136 #else // ndef DTRACE_ENABLED 137 138 #define DTRACE_THREAD_PROBE(probe, javathread) 139 140 #endif // ndef DTRACE_ENABLED 141 142 void JavaThread::smr_delete() { 143 if (_on_thread_list) { 144 ThreadsSMRSupport::smr_delete(this); 145 } else { 146 delete this; 147 } 148 } 149 150 // Initialized by VMThread at vm_global_init 151 OopStorage* JavaThread::_thread_oop_storage = nullptr; 152 153 OopStorage* JavaThread::thread_oop_storage() { 154 assert(_thread_oop_storage != nullptr, "not yet initialized"); 155 return _thread_oop_storage; 156 } 157 158 void JavaThread::set_threadOopHandles(oop p) { 159 assert(_thread_oop_storage != nullptr, "not yet initialized"); 160 _threadObj = OopHandle(_thread_oop_storage, p); 161 _vthread = OopHandle(_thread_oop_storage, p); 162 _jvmti_vthread = OopHandle(_thread_oop_storage, p->is_a(vmClasses::BoundVirtualThread_klass()) ? p : nullptr); 163 _scopedValueCache = OopHandle(_thread_oop_storage, nullptr); 164 } 165 166 oop JavaThread::threadObj() const { 167 // Ideally we would verify the current thread is oop_safe when this is called, but as we can 168 // be called from a signal handler we would have to use Thread::current_or_null_safe(). That 169 // has overhead and also interacts poorly with GetLastError on Windows due to the use of TLS. 170 // Instead callers must verify oop safe access. 171 return _threadObj.resolve(); 172 } 173 174 oop JavaThread::vthread() const { 175 return _vthread.resolve(); 176 } 177 178 void JavaThread::set_vthread(oop p) { 179 assert(_thread_oop_storage != nullptr, "not yet initialized"); 180 _vthread.replace(p); 181 } 182 183 oop JavaThread::jvmti_vthread() const { 184 return _jvmti_vthread.resolve(); 185 } 186 187 void JavaThread::set_jvmti_vthread(oop p) { 188 assert(_thread_oop_storage != nullptr, "not yet initialized"); 189 _jvmti_vthread.replace(p); 190 } 191 192 // If there is a virtual thread mounted then return vthread() oop. 193 // Otherwise, return threadObj(). 194 oop JavaThread::vthread_or_thread() const { 195 oop result = vthread(); 196 if (result == nullptr) { 197 result = threadObj(); 198 } 199 return result; 200 } 201 202 oop JavaThread::scopedValueCache() const { 203 return _scopedValueCache.resolve(); 204 } 205 206 void JavaThread::set_scopedValueCache(oop p) { 207 if (!_scopedValueCache.is_empty()) { // i.e. if the OopHandle has been allocated 208 _scopedValueCache.replace(p); 209 } else { 210 assert(p == nullptr, "not yet initialized"); 211 } 212 } 213 214 void JavaThread::clear_scopedValueBindings() { 215 set_scopedValueCache(nullptr); 216 oop vthread_oop = vthread(); 217 // vthread may be null here if we get a VM error during startup, 218 // before the java.lang.Thread instance has been created. 219 if (vthread_oop != nullptr) { 220 java_lang_Thread::clear_scopedValueBindings(vthread_oop); 221 } 222 } 223 224 void JavaThread::allocate_threadObj(Handle thread_group, const char* thread_name, 225 bool daemon, TRAPS) { 226 assert(thread_group.not_null(), "thread group should be specified"); 227 assert(threadObj() == nullptr, "should only create Java thread object once"); 228 229 InstanceKlass* ik = vmClasses::Thread_klass(); 230 assert(ik->is_initialized(), "must be"); 231 instanceHandle thread_oop = ik->allocate_instance_handle(CHECK); 232 233 // We are called from jni_AttachCurrentThread/jni_AttachCurrentThreadAsDaemon. 234 // We cannot use JavaCalls::construct_new_instance because the java.lang.Thread 235 // constructor calls Thread.current(), which must be set here. 236 java_lang_Thread::set_thread(thread_oop(), this); 237 set_threadOopHandles(thread_oop()); 238 239 JavaValue result(T_VOID); 240 if (thread_name != nullptr) { 241 Handle name = java_lang_String::create_from_str(thread_name, CHECK); 242 // Thread gets assigned specified name and null target 243 JavaCalls::call_special(&result, 244 thread_oop, 245 ik, 246 vmSymbols::object_initializer_name(), 247 vmSymbols::threadgroup_string_void_signature(), 248 thread_group, 249 name, 250 CHECK); 251 } else { 252 // Thread gets assigned name "Thread-nnn" and null target 253 // (java.lang.Thread doesn't have a constructor taking only a ThreadGroup argument) 254 JavaCalls::call_special(&result, 255 thread_oop, 256 ik, 257 vmSymbols::object_initializer_name(), 258 vmSymbols::threadgroup_runnable_void_signature(), 259 thread_group, 260 Handle(), 261 CHECK); 262 } 263 264 os::set_priority(this, NormPriority); 265 266 if (daemon) { 267 java_lang_Thread::set_daemon(thread_oop()); 268 } 269 } 270 271 // ======= JavaThread ======== 272 273 #if INCLUDE_JVMCI 274 275 jlong* JavaThread::_jvmci_old_thread_counters; 276 277 static bool jvmci_counters_include(JavaThread* thread) { 278 return !JVMCICountersExcludeCompiler || !thread->is_Compiler_thread(); 279 } 280 281 void JavaThread::collect_counters(jlong* array, int length) { 282 assert(length == JVMCICounterSize, "wrong value"); 283 for (int i = 0; i < length; i++) { 284 array[i] = _jvmci_old_thread_counters[i]; 285 } 286 for (JavaThread* tp : ThreadsListHandle()) { 287 if (jvmci_counters_include(tp)) { 288 for (int i = 0; i < length; i++) { 289 array[i] += tp->_jvmci_counters[i]; 290 } 291 } 292 } 293 } 294 295 // Attempt to enlarge the array for per thread counters. 296 static jlong* resize_counters_array(jlong* old_counters, int current_size, int new_size) { 297 jlong* new_counters = NEW_C_HEAP_ARRAY_RETURN_NULL(jlong, new_size, mtJVMCI); 298 if (new_counters == nullptr) { 299 return nullptr; 300 } 301 if (old_counters == nullptr) { 302 old_counters = new_counters; 303 memset(old_counters, 0, sizeof(jlong) * new_size); 304 } else { 305 for (int i = 0; i < MIN2((int) current_size, new_size); i++) { 306 new_counters[i] = old_counters[i]; 307 } 308 if (new_size > current_size) { 309 memset(new_counters + current_size, 0, sizeof(jlong) * (new_size - current_size)); 310 } 311 FREE_C_HEAP_ARRAY(jlong, old_counters); 312 } 313 return new_counters; 314 } 315 316 // Attempt to enlarge the array for per thread counters. 317 bool JavaThread::resize_counters(int current_size, int new_size) { 318 jlong* new_counters = resize_counters_array(_jvmci_counters, current_size, new_size); 319 if (new_counters == nullptr) { 320 return false; 321 } else { 322 _jvmci_counters = new_counters; 323 return true; 324 } 325 } 326 327 class VM_JVMCIResizeCounters : public VM_Operation { 328 private: 329 int _new_size; 330 bool _failed; 331 332 public: 333 VM_JVMCIResizeCounters(int new_size) : _new_size(new_size), _failed(false) { } 334 VMOp_Type type() const { return VMOp_JVMCIResizeCounters; } 335 bool allow_nested_vm_operations() const { return true; } 336 void doit() { 337 // Resize the old thread counters array 338 jlong* new_counters = resize_counters_array(JavaThread::_jvmci_old_thread_counters, JVMCICounterSize, _new_size); 339 if (new_counters == nullptr) { 340 _failed = true; 341 return; 342 } else { 343 JavaThread::_jvmci_old_thread_counters = new_counters; 344 } 345 346 // Now resize each threads array 347 for (JavaThread* tp : ThreadsListHandle()) { 348 if (!tp->resize_counters(JVMCICounterSize, _new_size)) { 349 _failed = true; 350 break; 351 } 352 } 353 if (!_failed) { 354 JVMCICounterSize = _new_size; 355 } 356 } 357 358 bool failed() { return _failed; } 359 }; 360 361 bool JavaThread::resize_all_jvmci_counters(int new_size) { 362 VM_JVMCIResizeCounters op(new_size); 363 VMThread::execute(&op); 364 return !op.failed(); 365 } 366 367 #endif // INCLUDE_JVMCI 368 369 #ifdef ASSERT 370 // Checks safepoint allowed and clears unhandled oops at potential safepoints. 371 void JavaThread::check_possible_safepoint() { 372 if (_no_safepoint_count > 0) { 373 print_owned_locks(); 374 assert(false, "Possible safepoint reached by thread that does not allow it"); 375 } 376 #ifdef CHECK_UNHANDLED_OOPS 377 // Clear unhandled oops in JavaThreads so we get a crash right away. 378 clear_unhandled_oops(); 379 #endif // CHECK_UNHANDLED_OOPS 380 381 // Macos/aarch64 should be in the right state for safepoint (e.g. 382 // deoptimization needs WXWrite). Crashes caused by the wrong state rarely 383 // happens in practice, making such issues hard to find and reproduce. 384 #if defined(__APPLE__) && defined(AARCH64) 385 if (AssertWXAtThreadSync) { 386 assert_wx_state(WXWrite); 387 } 388 #endif 389 } 390 391 void JavaThread::check_for_valid_safepoint_state() { 392 // Don't complain if running a debugging command. 393 if (DebuggingContext::is_enabled()) return; 394 395 // Check NoSafepointVerifier, which is implied by locks taken that can be 396 // shared with the VM thread. This makes sure that no locks with allow_vm_block 397 // are held. 398 check_possible_safepoint(); 399 400 if (thread_state() != _thread_in_vm) { 401 fatal("LEAF method calling lock?"); 402 } 403 404 if (GCALotAtAllSafepoints) { 405 // We could enter a safepoint here and thus have a gc 406 InterfaceSupport::check_gc_alot(); 407 } 408 } 409 #endif // ASSERT 410 411 // A JavaThread is a normal Java thread 412 413 JavaThread::JavaThread(MemTag mem_tag) : 414 Thread(mem_tag), 415 // Initialize fields 416 _on_thread_list(false), 417 DEBUG_ONLY(_java_call_counter(0) COMMA) 418 _entry_point(nullptr), 419 _deopt_mark(nullptr), 420 _deopt_nmethod(nullptr), 421 _vframe_array_head(nullptr), 422 _vframe_array_last(nullptr), 423 _jvmti_deferred_updates(nullptr), 424 _callee_target(nullptr), 425 _vm_result_oop(nullptr), 426 _vm_result_metadata(nullptr), 427 428 _current_pending_monitor(nullptr), 429 _current_pending_monitor_is_from_java(true), 430 _current_waiting_monitor(nullptr), 431 _active_handles(nullptr), 432 _free_handle_block(nullptr), 433 _monitor_owner_id(0), 434 435 _suspend_flags(0), 436 437 _thread_state(_thread_new), 438 _saved_exception_pc(nullptr), 439 #ifdef ASSERT 440 _no_safepoint_count(0), 441 _visited_for_critical_count(false), 442 #endif 443 444 _terminated(_not_terminated), 445 _in_deopt_handler(0), 446 _doing_unsafe_access(false), 447 _do_not_unlock_if_synchronized(false), 448 #if INCLUDE_JVMTI 449 _carrier_thread_suspended(false), 450 _is_in_VTMS_transition(false), 451 _is_disable_suspend(false), 452 _is_in_java_upcall(false), 453 _VTMS_transition_mark(false), 454 _on_monitor_waited_event(false), 455 _contended_entered_monitor(nullptr), 456 #ifdef ASSERT 457 _is_VTMS_transition_disabler(false), 458 #endif 459 #endif 460 _jni_attach_state(_not_attaching_via_jni), 461 _is_in_internal_oome_mark(false), 462 #if INCLUDE_JVMCI 463 _pending_deoptimization(-1), 464 _pending_monitorenter(false), 465 _pending_transfer_to_interpreter(false), 466 _pending_failed_speculation(0), 467 _jvmci{nullptr}, 468 _libjvmci_runtime(nullptr), 469 _jvmci_counters(nullptr), 470 _jvmci_reserved0(0), 471 _jvmci_reserved1(0), 472 _jvmci_reserved_oop0(nullptr), 473 _live_nmethod(nullptr), 474 #endif // INCLUDE_JVMCI 475 476 _exception_oop(oop()), 477 _exception_pc(nullptr), 478 _exception_handler_pc(nullptr), 479 _is_method_handle_return(0), 480 481 _jni_active_critical(0), 482 _pending_jni_exception_check_fn(nullptr), 483 _depth_first_number(0), 484 485 // JVMTI PopFrame support 486 _popframe_condition(popframe_inactive), 487 _frames_to_pop_failed_realloc(0), 488 489 _cont_entry(nullptr), 490 _cont_fastpath(nullptr), 491 _cont_fastpath_thread_state(1), 492 _held_monitor_count(0), 493 _jni_monitor_count(0), 494 _unlocked_inflated_monitor(nullptr), 495 496 _can_call_java(true), 497 498 _preempt_alternate_return(nullptr), 499 _preemption_cancelled(false), 500 _pending_interrupted_exception(false), 501 502 _handshake(this), 503 _suspend_resume_manager(this, &_handshake._lock), 504 505 _popframe_preserved_args(nullptr), 506 _popframe_preserved_args_size(0), 507 508 _jvmti_thread_state(nullptr), 509 _interp_only_mode(0), 510 _should_post_on_exceptions_flag(JNI_FALSE), 511 _thread_stat(new ThreadStatistics()), 512 513 _parker(), 514 515 _class_to_be_initialized(nullptr), 516 _class_being_initialized(nullptr), 517 518 _SleepEvent(ParkEvent::Allocate(this)), 519 520 #if INCLUDE_JFR 521 _last_freeze_fail_result(freeze_ok), 522 #endif 523 524 _lock_stack(this), 525 _om_cache(this) { 526 set_jni_functions(jni_functions()); 527 528 #if INCLUDE_JVMCI 529 assert(_jvmci._implicit_exception_pc == nullptr, "must be"); 530 if (JVMCICounterSize > 0) { 531 resize_counters(0, (int) JVMCICounterSize); 532 } 533 #endif // INCLUDE_JVMCI 534 535 // Setup safepoint state info for this thread 536 ThreadSafepointState::create(this); 537 538 SafepointMechanism::initialize_header(this); 539 540 set_requires_cross_modify_fence(false); 541 542 pd_initialize(); 543 assert(deferred_card_mark().is_empty(), "Default MemRegion ctor"); 544 } 545 546 JavaThread* JavaThread::create_attaching_thread() { 547 JavaThread* jt = new JavaThread(); 548 jt->_jni_attach_state = _attaching_via_jni; 549 return jt; 550 } 551 552 // interrupt support 553 554 void JavaThread::interrupt() { 555 // All callers should have 'this' thread protected by a 556 // ThreadsListHandle so that it cannot terminate and deallocate 557 // itself. 558 DEBUG_ONLY(check_for_dangling_thread_pointer(this);) 559 560 // For Windows _interrupt_event 561 WINDOWS_ONLY(osthread()->set_interrupted(true);) 562 563 // For Thread.sleep 564 _SleepEvent->unpark(); 565 566 // For JSR166 LockSupport.park 567 parker()->unpark(); 568 569 // For ObjectMonitor and JvmtiRawMonitor 570 _ParkEvent->unpark(); 571 } 572 573 bool JavaThread::is_interrupted(bool clear_interrupted) { 574 DEBUG_ONLY(check_for_dangling_thread_pointer(this);) 575 576 if (_threadObj.peek() == nullptr) { 577 // If there is no j.l.Thread then it is impossible to have 578 // been interrupted. We can find null during VM initialization 579 // or when a JNI thread is still in the process of attaching. 580 // In such cases this must be the current thread. 581 assert(this == Thread::current(), "invariant"); 582 return false; 583 } 584 585 bool interrupted = java_lang_Thread::interrupted(threadObj()); 586 587 // NOTE that since there is no "lock" around the interrupt and 588 // is_interrupted operations, there is the possibility that the 589 // interrupted flag will be "false" but that the 590 // low-level events will be in the signaled state. This is 591 // intentional. The effect of this is that Object.wait() and 592 // LockSupport.park() will appear to have a spurious wakeup, which 593 // is allowed and not harmful, and the possibility is so rare that 594 // it is not worth the added complexity to add yet another lock. 595 // For the sleep event an explicit reset is performed on entry 596 // to JavaThread::sleep, so there is no early return. It has also been 597 // recommended not to put the interrupted flag into the "event" 598 // structure because it hides the issue. 599 // Also, because there is no lock, we must only clear the interrupt 600 // state if we are going to report that we were interrupted; otherwise 601 // an interrupt that happens just after we read the field would be lost. 602 if (interrupted && clear_interrupted) { 603 assert(this == Thread::current(), "only the current thread can clear"); 604 java_lang_Thread::set_interrupted(threadObj(), false); 605 WINDOWS_ONLY(osthread()->set_interrupted(false);) 606 } 607 return interrupted; 608 } 609 610 // This is only for use by JVMTI RawMonitorWait. It emulates the actions of 611 // the Java code in Object::wait which are not present in RawMonitorWait. 612 bool JavaThread::get_and_clear_interrupted() { 613 if (!is_interrupted(false)) { 614 return false; 615 } 616 oop thread_oop = vthread_or_thread(); 617 bool is_virtual = java_lang_VirtualThread::is_instance(thread_oop); 618 619 if (!is_virtual) { 620 return is_interrupted(true); 621 } 622 // Virtual thread: clear interrupt status for both virtual and 623 // carrier threads under the interruptLock protection. 624 JavaThread* current = JavaThread::current(); 625 HandleMark hm(current); 626 Handle thread_h(current, thread_oop); 627 ObjectLocker lock(Handle(current, java_lang_Thread::interrupt_lock(thread_h())), current); 628 629 // re-check the interrupt status under the interruptLock protection 630 bool interrupted = java_lang_Thread::interrupted(thread_h()); 631 632 if (interrupted) { 633 assert(this == Thread::current(), "only the current thread can clear"); 634 java_lang_Thread::set_interrupted(thread_h(), false); // clear for virtual 635 java_lang_Thread::set_interrupted(threadObj(), false); // clear for carrier 636 WINDOWS_ONLY(osthread()->set_interrupted(false);) 637 } 638 return interrupted; 639 } 640 641 void JavaThread::block_if_vm_exited() { 642 if (_terminated == _vm_exited) { 643 // _vm_exited is set at safepoint, and Threads_lock is never released 644 // so we will block here forever. 645 // Here we can be doing a jump from a safe state to an unsafe state without 646 // proper transition, but it happens after the final safepoint has begun so 647 // this jump won't cause any safepoint problems. 648 set_thread_state(_thread_in_vm); 649 Threads_lock->lock(); 650 ShouldNotReachHere(); 651 } 652 } 653 654 JavaThread::JavaThread(ThreadFunction entry_point, size_t stack_sz, MemTag mem_tag) : JavaThread(mem_tag) { 655 set_entry_point(entry_point); 656 // Create the native thread itself. 657 // %note runtime_23 658 os::ThreadType thr_type = os::java_thread; 659 thr_type = entry_point == &CompilerThread::thread_entry ? os::compiler_thread : 660 os::java_thread; 661 os::create_thread(this, thr_type, stack_sz); 662 // The _osthread may be null here because we ran out of memory (too many threads active). 663 // We need to throw and OutOfMemoryError - however we cannot do this here because the caller 664 // may hold a lock and all locks must be unlocked before throwing the exception (throwing 665 // the exception consists of creating the exception object & initializing it, initialization 666 // will leave the VM via a JavaCall and then all locks must be unlocked). 667 // 668 // The thread is still suspended when we reach here. Thread must be explicit started 669 // by creator! Furthermore, the thread must also explicitly be added to the Threads list 670 // by calling Threads:add. The reason why this is not done here, is because the thread 671 // object must be fully initialized (take a look at JVM_Start) 672 } 673 674 JavaThread::~JavaThread() { 675 676 // Enqueue OopHandles for release by the service thread. 677 add_oop_handles_for_release(); 678 679 // Return the sleep event to the free list 680 ParkEvent::Release(_SleepEvent); 681 _SleepEvent = nullptr; 682 683 // Free any remaining previous UnrollBlock 684 vframeArray* old_array = vframe_array_last(); 685 686 if (old_array != nullptr) { 687 Deoptimization::UnrollBlock* old_info = old_array->unroll_block(); 688 old_array->set_unroll_block(nullptr); 689 delete old_info; 690 delete old_array; 691 } 692 693 JvmtiDeferredUpdates* updates = deferred_updates(); 694 if (updates != nullptr) { 695 // This can only happen if thread is destroyed before deoptimization occurs. 696 assert(updates->count() > 0, "Updates holder not deleted"); 697 // free deferred updates. 698 delete updates; 699 set_deferred_updates(nullptr); 700 } 701 702 // All Java related clean up happens in exit 703 ThreadSafepointState::destroy(this); 704 if (_thread_stat != nullptr) delete _thread_stat; 705 706 #if INCLUDE_JVMCI 707 if (JVMCICounterSize > 0) { 708 FREE_C_HEAP_ARRAY(jlong, _jvmci_counters); 709 } 710 #endif // INCLUDE_JVMCI 711 } 712 713 714 // First JavaThread specific code executed by a new Java thread. 715 void JavaThread::pre_run() { 716 // empty - see comments in run() 717 } 718 719 // The main routine called by a new Java thread. This isn't overridden 720 // by subclasses, instead different subclasses define a different "entry_point" 721 // which defines the actual logic for that kind of thread. 722 void JavaThread::run() { 723 // initialize thread-local alloc buffer related fields 724 initialize_tlab(); 725 726 _stack_overflow_state.create_stack_guard_pages(); 727 728 cache_global_variables(); 729 730 // Thread is now sufficiently initialized to be handled by the safepoint code as being 731 // in the VM. Change thread state from _thread_new to _thread_in_vm 732 assert(this->thread_state() == _thread_new, "wrong thread state"); 733 set_thread_state(_thread_in_vm); 734 735 // Before a thread is on the threads list it is always safe, so after leaving the 736 // _thread_new we should emit a instruction barrier. The distance to modified code 737 // from here is probably far enough, but this is consistent and safe. 738 OrderAccess::cross_modify_fence(); 739 740 assert(JavaThread::current() == this, "sanity check"); 741 assert(!Thread::current()->owns_locks(), "sanity check"); 742 743 JFR_ONLY(Jfr::on_thread_start(this);) 744 745 DTRACE_THREAD_PROBE(start, this); 746 747 // This operation might block. We call that after all safepoint checks for a new thread has 748 // been completed. 749 set_active_handles(JNIHandleBlock::allocate_block()); 750 751 if (JvmtiExport::should_post_thread_life()) { 752 JvmtiExport::post_thread_start(this); 753 754 } 755 756 if (AlwaysPreTouchStacks) { 757 pretouch_stack(); 758 } 759 760 // We call another function to do the rest so we are sure that the stack addresses used 761 // from there will be lower than the stack base just computed. 762 thread_main_inner(); 763 } 764 765 void JavaThread::thread_main_inner() { 766 assert(JavaThread::current() == this, "sanity check"); 767 assert(_threadObj.peek() != nullptr, "just checking"); 768 769 // Execute thread entry point unless this thread has a pending exception. 770 // Note: Due to JVMTI StopThread we can have pending exceptions already! 771 if (!this->has_pending_exception()) { 772 { 773 ResourceMark rm(this); 774 this->set_native_thread_name(this->name()); 775 } 776 HandleMark hm(this); 777 this->entry_point()(this, this); 778 } 779 780 DTRACE_THREAD_PROBE(stop, this); 781 782 // Cleanup is handled in post_run() 783 } 784 785 // Shared teardown for all JavaThreads 786 void JavaThread::post_run() { 787 this->exit(false); 788 this->unregister_thread_stack_with_NMT(); 789 // Defer deletion to here to ensure 'this' is still referenceable in call_run 790 // for any shared tear-down. 791 this->smr_delete(); 792 } 793 794 static void ensure_join(JavaThread* thread) { 795 // We do not need to grab the Threads_lock, since we are operating on ourself. 796 Handle threadObj(thread, thread->threadObj()); 797 assert(threadObj.not_null(), "java thread object must exist"); 798 ObjectLocker lock(threadObj, thread); 799 // Thread is exiting. So set thread_status field in java.lang.Thread class to TERMINATED. 800 java_lang_Thread::set_thread_status(threadObj(), JavaThreadStatus::TERMINATED); 801 // Clear the native thread instance - this makes isAlive return false and allows the join() 802 // to complete once we've done the notify_all below. Needs a release() to obey Java Memory Model 803 // requirements. 804 assert(java_lang_Thread::thread(threadObj()) == thread, "must be alive"); 805 java_lang_Thread::release_set_thread(threadObj(), nullptr); 806 lock.notify_all(thread); 807 // Ignore pending exception, since we are exiting anyway 808 thread->clear_pending_exception(); 809 } 810 811 static bool is_daemon(oop threadObj) { 812 return (threadObj != nullptr && java_lang_Thread::is_daemon(threadObj)); 813 } 814 815 // For any new cleanup additions, please check to see if they need to be applied to 816 // cleanup_failed_attach_current_thread as well. 817 void JavaThread::exit(bool destroy_vm, ExitType exit_type) { 818 assert(this == JavaThread::current(), "thread consistency check"); 819 assert(!is_exiting(), "should not be exiting or terminated already"); 820 821 elapsedTimer _timer_exit_phase1; 822 elapsedTimer _timer_exit_phase2; 823 elapsedTimer _timer_exit_phase3; 824 elapsedTimer _timer_exit_phase4; 825 826 om_clear_monitor_cache(); 827 828 if (log_is_enabled(Debug, os, thread, timer)) { 829 _timer_exit_phase1.start(); 830 } 831 832 HandleMark hm(this); 833 Handle uncaught_exception(this, this->pending_exception()); 834 this->clear_pending_exception(); 835 Handle threadObj(this, this->threadObj()); 836 assert(threadObj.not_null(), "Java thread object should be created"); 837 838 if (!destroy_vm) { 839 if (uncaught_exception.not_null()) { 840 EXCEPTION_MARK; 841 // Call method Thread.dispatchUncaughtException(). 842 Klass* thread_klass = vmClasses::Thread_klass(); 843 JavaValue result(T_VOID); 844 JavaCalls::call_virtual(&result, 845 threadObj, thread_klass, 846 vmSymbols::dispatchUncaughtException_name(), 847 vmSymbols::throwable_void_signature(), 848 uncaught_exception, 849 THREAD); 850 if (HAS_PENDING_EXCEPTION) { 851 ResourceMark rm(this); 852 jio_fprintf(defaultStream::error_stream(), 853 "\nException: %s thrown from the UncaughtExceptionHandler" 854 " in thread \"%s\"\n", 855 pending_exception()->klass()->external_name(), 856 name()); 857 CLEAR_PENDING_EXCEPTION; 858 } 859 } 860 861 if (!is_Compiler_thread()) { 862 // We have finished executing user-defined Java code and now have to do the 863 // implementation specific clean-up by calling Thread.exit(). We prevent any 864 // asynchronous exceptions from being delivered while in Thread.exit() 865 // to ensure the clean-up is not corrupted. 866 NoAsyncExceptionDeliveryMark _no_async(this); 867 868 EXCEPTION_MARK; 869 JavaValue result(T_VOID); 870 Klass* thread_klass = vmClasses::Thread_klass(); 871 JavaCalls::call_virtual(&result, 872 threadObj, thread_klass, 873 vmSymbols::exit_method_name(), 874 vmSymbols::void_method_signature(), 875 THREAD); 876 CLEAR_PENDING_EXCEPTION; 877 } 878 879 // notify JVMTI 880 if (JvmtiExport::should_post_thread_life()) { 881 JvmtiExport::post_thread_end(this); 882 } 883 } else { 884 // before_exit() has already posted JVMTI THREAD_END events 885 } 886 887 // Cleanup any pending async exception now since we cannot access oops after 888 // BarrierSet::barrier_set()->on_thread_detach() has been executed. 889 if (has_async_exception_condition()) { 890 handshake_state()->clean_async_exception_operation(); 891 } 892 893 // The careful dance between thread suspension and exit is handled here. 894 // Since we are in thread_in_vm state and suspension is done with handshakes, 895 // we can just put in the exiting state and it will be correctly handled. 896 // Also, no more async exceptions will be added to the queue after this point. 897 set_terminated(_thread_exiting); 898 ThreadService::current_thread_exiting(this, is_daemon(threadObj())); 899 900 if (log_is_enabled(Debug, os, thread, timer)) { 901 _timer_exit_phase1.stop(); 902 _timer_exit_phase2.start(); 903 } 904 905 // Capture daemon status before the thread is marked as terminated. 906 bool daemon = is_daemon(threadObj()); 907 908 // Notify waiters on thread object. This has to be done after exit() is called 909 // on the thread (if the thread is the last thread in a daemon ThreadGroup the 910 // group should have the destroyed bit set before waiters are notified). 911 ensure_join(this); 912 assert(!this->has_pending_exception(), "ensure_join should have cleared"); 913 914 if (log_is_enabled(Debug, os, thread, timer)) { 915 _timer_exit_phase2.stop(); 916 _timer_exit_phase3.start(); 917 } 918 // 6282335 JNI DetachCurrentThread spec states that all Java monitors 919 // held by this thread must be released. The spec does not distinguish 920 // between JNI-acquired and regular Java monitors. We can only see 921 // regular Java monitors here if monitor enter-exit matching is broken. 922 // 923 // ensure_join() ignores IllegalThreadStateExceptions, and so does 924 // ObjectSynchronizer::release_monitors_owned_by_thread(). 925 if (exit_type == jni_detach) { 926 // Sanity check even though JNI DetachCurrentThread() would have 927 // returned JNI_ERR if there was a Java frame. JavaThread exit 928 // should be done executing Java code by the time we get here. 929 assert(!this->has_last_Java_frame(), 930 "should not have a Java frame when detaching or exiting"); 931 ObjectSynchronizer::release_monitors_owned_by_thread(this); 932 assert(!this->has_pending_exception(), "release_monitors should have cleared"); 933 // Check for monitor counts being out of sync. 934 assert(held_monitor_count() == jni_monitor_count(), 935 "held monitor count should be equal to jni: %zd != %zd", 936 held_monitor_count(), jni_monitor_count()); 937 // All in-use monitors, including JNI-locked ones, should have been released above. 938 assert(held_monitor_count() == 0, "Failed to unlock %zd object monitors", 939 held_monitor_count()); 940 } else { 941 // Check for monitor counts being out of sync. 942 assert(held_monitor_count() == jni_monitor_count(), 943 "held monitor count should be equal to jni: %zd != %zd", 944 held_monitor_count(), jni_monitor_count()); 945 // It is possible that a terminating thread failed to unlock monitors it locked 946 // via JNI so we don't assert the count is zero. 947 } 948 949 if (CheckJNICalls && jni_monitor_count() > 0) { 950 // We would like a fatal here, but due to we never checked this before there 951 // is a lot of tests which breaks, even with an error log. 952 log_debug(jni)("JavaThread %s (tid: %zu) with Objects still locked by JNI MonitorEnter.", 953 exit_type == JavaThread::normal_exit ? "exiting" : "detaching", os::current_thread_id()); 954 } 955 956 // These things needs to be done while we are still a Java Thread. Make sure that thread 957 // is in a consistent state, in case GC happens 958 JFR_ONLY(Jfr::on_thread_exit(this);) 959 960 if (active_handles() != nullptr) { 961 JNIHandleBlock* block = active_handles(); 962 set_active_handles(nullptr); 963 JNIHandleBlock::release_block(block); 964 } 965 966 if (free_handle_block() != nullptr) { 967 JNIHandleBlock* block = free_handle_block(); 968 set_free_handle_block(nullptr); 969 JNIHandleBlock::release_block(block); 970 } 971 972 // These have to be removed while this is still a valid thread. 973 _stack_overflow_state.remove_stack_guard_pages(); 974 975 if (UseTLAB) { 976 retire_tlab(); 977 } 978 979 if (JvmtiEnv::environments_might_exist()) { 980 JvmtiExport::cleanup_thread(this); 981 } 982 983 // We need to cache the thread name for logging purposes below as once 984 // we have called on_thread_detach this thread must not access any oops. 985 char* thread_name = nullptr; 986 if (log_is_enabled(Debug, os, thread, timer) || (CountBytecodesPerThread && log_is_enabled(Info, init))) { 987 ResourceMark rm(this); 988 thread_name = os::strdup(name()); 989 } 990 991 if (log_is_enabled(Info, os, thread)) { 992 ResourceMark rm(this); 993 log_info(os, thread)("JavaThread %s (name: \"%s\", tid: %zu).", 994 exit_type == JavaThread::normal_exit ? "exiting" : "detaching", 995 name(), os::current_thread_id()); 996 } 997 998 if (log_is_enabled(Debug, os, thread, timer)) { 999 _timer_exit_phase3.stop(); 1000 _timer_exit_phase4.start(); 1001 } 1002 1003 #if INCLUDE_JVMCI 1004 if (JVMCICounterSize > 0) { 1005 if (jvmci_counters_include(this)) { 1006 for (int i = 0; i < JVMCICounterSize; i++) { 1007 _jvmci_old_thread_counters[i] += _jvmci_counters[i]; 1008 } 1009 } 1010 } 1011 #endif // INCLUDE_JVMCI 1012 1013 if (bc_counter_value() > 0) { 1014 log_info(init)("Thread '%s': " JLONG_FORMAT " bytecodes executed (during clinit: " JLONG_FORMAT ")", 1015 thread_name, bc_counter_value(), clinit_bc_counter_value()); 1016 } 1017 1018 // Remove from list of active threads list, and notify VM thread if we are the last non-daemon thread. 1019 // We call BarrierSet::barrier_set()->on_thread_detach() here so no touching of oops after this point. 1020 Threads::remove(this, daemon); 1021 1022 if (log_is_enabled(Debug, os, thread, timer)) { 1023 _timer_exit_phase4.stop(); 1024 log_debug(os, thread, timer)("name='%s'" 1025 ", exit-phase1=" JLONG_FORMAT 1026 ", exit-phase2=" JLONG_FORMAT 1027 ", exit-phase3=" JLONG_FORMAT 1028 ", exit-phase4=" JLONG_FORMAT, 1029 thread_name, 1030 _timer_exit_phase1.milliseconds(), 1031 _timer_exit_phase2.milliseconds(), 1032 _timer_exit_phase3.milliseconds(), 1033 _timer_exit_phase4.milliseconds()); 1034 os::free(thread_name); 1035 } 1036 } 1037 1038 void JavaThread::cleanup_failed_attach_current_thread(bool is_daemon) { 1039 if (active_handles() != nullptr) { 1040 JNIHandleBlock* block = active_handles(); 1041 set_active_handles(nullptr); 1042 JNIHandleBlock::release_block(block); 1043 } 1044 1045 if (free_handle_block() != nullptr) { 1046 JNIHandleBlock* block = free_handle_block(); 1047 set_free_handle_block(nullptr); 1048 JNIHandleBlock::release_block(block); 1049 } 1050 1051 // These have to be removed while this is still a valid thread. 1052 _stack_overflow_state.remove_stack_guard_pages(); 1053 1054 if (UseTLAB) { 1055 retire_tlab(); 1056 } 1057 1058 Threads::remove(this, is_daemon); 1059 } 1060 1061 JavaThread* JavaThread::active() { 1062 Thread* thread = Thread::current(); 1063 if (thread->is_Java_thread()) { 1064 return JavaThread::cast(thread); 1065 } else { 1066 assert(thread->is_VM_thread(), "this must be a vm thread"); 1067 VM_Operation* op = ((VMThread*) thread)->vm_operation(); 1068 JavaThread *ret = op == nullptr ? nullptr : JavaThread::cast(op->calling_thread()); 1069 return ret; 1070 } 1071 } 1072 1073 oop JavaThread::exception_oop() const { 1074 return AtomicAccess::load(&_exception_oop); 1075 } 1076 1077 void JavaThread::set_exception_oop(oop o) { 1078 AtomicAccess::store(&_exception_oop, o); 1079 } 1080 1081 void JavaThread::handle_special_runtime_exit_condition() { 1082 if (is_obj_deopt_suspend()) { 1083 frame_anchor()->make_walkable(); 1084 wait_for_object_deoptimization(); 1085 } 1086 } 1087 1088 1089 // Asynchronous exceptions support 1090 // 1091 void JavaThread::handle_async_exception(oop java_throwable) { 1092 assert(java_throwable != nullptr, "should have an _async_exception to throw"); 1093 assert(!is_at_poll_safepoint(), "should have never called this method"); 1094 1095 if (has_last_Java_frame()) { 1096 frame f = last_frame(); 1097 if (f.is_runtime_frame()) { 1098 // If the topmost frame is a runtime stub, then we are calling into 1099 // OptoRuntime from compiled code. Some runtime stubs (new, monitor_exit..) 1100 // must deoptimize the caller before continuing, as the compiled exception 1101 // handler table may not be valid. 1102 RegisterMap reg_map(this, 1103 RegisterMap::UpdateMap::skip, 1104 RegisterMap::ProcessFrames::include, 1105 RegisterMap::WalkContinuation::skip); 1106 frame compiled_frame = f.sender(®_map); 1107 if (!StressCompiledExceptionHandlers && compiled_frame.can_be_deoptimized()) { 1108 Deoptimization::deoptimize(this, compiled_frame); 1109 } 1110 } 1111 } 1112 1113 // We cannot call Exceptions::_throw(...) here because we cannot block 1114 set_pending_exception(java_throwable, __FILE__, __LINE__); 1115 1116 clear_scopedValueBindings(); 1117 1118 LogTarget(Info, exceptions) lt; 1119 if (lt.is_enabled()) { 1120 ResourceMark rm; 1121 LogStream ls(lt); 1122 ls.print("Async. exception installed at runtime exit (" INTPTR_FORMAT ")", p2i(this)); 1123 if (has_last_Java_frame()) { 1124 frame f = last_frame(); 1125 ls.print(" (pc: " INTPTR_FORMAT " sp: " INTPTR_FORMAT " )", p2i(f.pc()), p2i(f.sp())); 1126 } 1127 ls.print_cr(" of type: %s", java_throwable->klass()->external_name()); 1128 } 1129 } 1130 1131 void JavaThread::install_async_exception(AsyncExceptionHandshakeClosure* aehc) { 1132 // Do not throw asynchronous exceptions against the compiler thread 1133 // or if the thread is already exiting. 1134 if (!can_call_java() || is_exiting()) { 1135 delete aehc; 1136 return; 1137 } 1138 1139 oop exception = aehc->exception(); 1140 Handshake::execute(aehc, this); // Install asynchronous handshake 1141 1142 ResourceMark rm; 1143 if (log_is_enabled(Info, exceptions)) { 1144 log_info(exceptions)("Pending Async. exception installed of type: %s", 1145 exception->klass()->external_name()); 1146 } 1147 // for AbortVMOnException flag 1148 Exceptions::debug_check_abort(exception->klass()->external_name()); 1149 1150 oop vt_oop = vthread(); 1151 if (vt_oop == nullptr || !vt_oop->is_a(vmClasses::BaseVirtualThread_klass())) { 1152 // Interrupt thread so it will wake up from a potential wait()/sleep()/park() 1153 this->interrupt(); 1154 } 1155 } 1156 1157 class InstallAsyncExceptionHandshakeClosure : public HandshakeClosure { 1158 AsyncExceptionHandshakeClosure* _aehc; 1159 public: 1160 InstallAsyncExceptionHandshakeClosure(AsyncExceptionHandshakeClosure* aehc) : 1161 HandshakeClosure("InstallAsyncException"), _aehc(aehc) {} 1162 ~InstallAsyncExceptionHandshakeClosure() { 1163 // If InstallAsyncExceptionHandshakeClosure was never executed we need to clean up _aehc. 1164 delete _aehc; 1165 } 1166 void do_thread(Thread* thr) { 1167 JavaThread* target = JavaThread::cast(thr); 1168 target->install_async_exception(_aehc); 1169 _aehc = nullptr; 1170 } 1171 }; 1172 1173 void JavaThread::send_async_exception(JavaThread* target, oop java_throwable) { 1174 OopHandle e(Universe::vm_global(), java_throwable); 1175 InstallAsyncExceptionHandshakeClosure iaeh(new AsyncExceptionHandshakeClosure(e)); 1176 Handshake::execute(&iaeh, target); 1177 } 1178 1179 #if INCLUDE_JVMTI 1180 void JavaThread::set_is_in_VTMS_transition(bool val) { 1181 assert(is_in_VTMS_transition() != val, "already %s transition", val ? "inside" : "outside"); 1182 _is_in_VTMS_transition = val; 1183 } 1184 1185 #ifdef ASSERT 1186 void JavaThread::set_is_VTMS_transition_disabler(bool val) { 1187 _is_VTMS_transition_disabler = val; 1188 } 1189 #endif 1190 #endif 1191 1192 // External suspension mechanism. 1193 // 1194 // Guarantees on return (for a valid target thread): 1195 // - Target thread will not execute any new bytecode. 1196 // - Target thread will not enter any new monitors. 1197 // 1198 bool JavaThread::java_suspend(bool register_vthread_SR) { 1199 #if INCLUDE_JVMTI 1200 // Suspending a JavaThread in VTMS transition or disabling VTMS transitions can cause deadlocks. 1201 assert(!is_in_VTMS_transition(), "no suspend allowed in VTMS transition"); 1202 assert(!is_VTMS_transition_disabler(), "no suspend allowed for VTMS transition disablers"); 1203 #endif 1204 1205 guarantee(Thread::is_JavaThread_protected(/* target */ this), 1206 "target JavaThread is not protected in calling context."); 1207 return this->suspend_resume_manager()->suspend(register_vthread_SR); 1208 } 1209 1210 bool JavaThread::java_resume(bool register_vthread_SR) { 1211 guarantee(Thread::is_JavaThread_protected_by_TLH(/* target */ this), 1212 "missing ThreadsListHandle in calling context."); 1213 return this->suspend_resume_manager()->resume(register_vthread_SR); 1214 } 1215 1216 // Wait for another thread to perform object reallocation and relocking on behalf of 1217 // this thread. The current thread is required to change to _thread_blocked in order 1218 // to be seen to be safepoint/handshake safe whilst suspended and only after becoming 1219 // handshake safe, the other thread can complete the handshake used to synchronize 1220 // with this thread and then perform the reallocation and relocking. 1221 // See EscapeBarrier::sync_and_suspend_*() 1222 1223 void JavaThread::wait_for_object_deoptimization() { 1224 assert(!has_last_Java_frame() || frame_anchor()->walkable(), "should have walkable stack"); 1225 assert(this == Thread::current(), "invariant"); 1226 1227 bool spin_wait = os::is_MP(); 1228 do { 1229 ThreadBlockInVM tbivm(this, true /* allow_suspend */); 1230 // Wait for object deoptimization if requested. 1231 if (spin_wait) { 1232 // A single deoptimization is typically very short. Microbenchmarks 1233 // showed 5% better performance when spinning. 1234 const uint spin_limit = 10 * SpinYield::default_spin_limit; 1235 SpinYield spin(spin_limit); 1236 for (uint i = 0; is_obj_deopt_suspend() && i < spin_limit; i++) { 1237 spin.wait(); 1238 } 1239 // Spin just once 1240 spin_wait = false; 1241 } else { 1242 MonitorLocker ml(this, EscapeBarrier_lock, Monitor::_no_safepoint_check_flag); 1243 if (is_obj_deopt_suspend()) { 1244 ml.wait(); 1245 } 1246 } 1247 // A handshake for obj. deoptimization suspend could have been processed so 1248 // we must check after processing. 1249 } while (is_obj_deopt_suspend()); 1250 } 1251 1252 #ifdef ASSERT 1253 // Verify the JavaThread has not yet been published in the Threads::list, and 1254 // hence doesn't need protection from concurrent access at this stage. 1255 void JavaThread::verify_not_published() { 1256 // Cannot create a ThreadsListHandle here and check !tlh.includes(this) 1257 // since an unpublished JavaThread doesn't participate in the 1258 // Thread-SMR protocol for keeping a ThreadsList alive. 1259 assert(!on_thread_list(), "JavaThread shouldn't have been published yet!"); 1260 } 1261 #endif 1262 1263 // Slow path when the native==>Java barriers detect a safepoint/handshake is 1264 // pending, when _suspend_flags is non-zero or when we need to process a stack 1265 // watermark. Also check for pending async exceptions (except unsafe access error). 1266 // Note only the native==>Java barriers can call this function when thread state 1267 // is _thread_in_native_trans. 1268 void JavaThread::check_special_condition_for_native_trans(JavaThread *thread) { 1269 assert(thread->thread_state() == _thread_in_native_trans, "wrong state"); 1270 assert(!thread->has_last_Java_frame() || thread->frame_anchor()->walkable(), "Unwalkable stack in native->Java transition"); 1271 1272 thread->set_thread_state(_thread_in_vm); 1273 1274 // Enable WXWrite: called directly from interpreter native wrapper. 1275 MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXWrite, thread)); 1276 1277 SafepointMechanism::process_if_requested_with_exit_check(thread, true /* check asyncs */); 1278 1279 // After returning from native, it could be that the stack frames are not 1280 // yet safe to use. We catch such situations in the subsequent stack watermark 1281 // barrier, which will trap unsafe stack frames. 1282 StackWatermarkSet::before_unwind(thread); 1283 } 1284 1285 #ifndef PRODUCT 1286 // Deoptimization 1287 // Function for testing deoptimization 1288 void JavaThread::deoptimize() { 1289 StackFrameStream fst(this, false /* update */, true /* process_frames */); 1290 bool deopt = false; // Dump stack only if a deopt actually happens. 1291 bool only_at = strlen(DeoptimizeOnlyAt) > 0; 1292 // Iterate over all frames in the thread and deoptimize 1293 for (; !fst.is_done(); fst.next()) { 1294 if (fst.current()->can_be_deoptimized()) { 1295 1296 if (only_at) { 1297 // Deoptimize only at particular bcis. DeoptimizeOnlyAt 1298 // consists of comma or carriage return separated numbers so 1299 // search for the current bci in that string. 1300 address pc = fst.current()->pc(); 1301 nmethod* nm = fst.current()->cb()->as_nmethod(); 1302 ScopeDesc* sd = nm->scope_desc_at(pc); 1303 char buffer[8]; 1304 jio_snprintf(buffer, sizeof(buffer), "%d", sd->bci()); 1305 size_t len = strlen(buffer); 1306 const char * found = strstr(DeoptimizeOnlyAt, buffer); 1307 while (found != nullptr) { 1308 if ((found[len] == ',' || found[len] == '\n' || found[len] == '\0') && 1309 (found == DeoptimizeOnlyAt || found[-1] == ',' || found[-1] == '\n')) { 1310 // Check that the bci found is bracketed by terminators. 1311 break; 1312 } 1313 found = strstr(found + 1, buffer); 1314 } 1315 if (!found) { 1316 continue; 1317 } 1318 } 1319 1320 if (DebugDeoptimization && !deopt) { 1321 deopt = true; // One-time only print before deopt 1322 tty->print_cr("[BEFORE Deoptimization]"); 1323 trace_frames(); 1324 trace_stack(); 1325 } 1326 Deoptimization::deoptimize(this, *fst.current()); 1327 } 1328 } 1329 1330 if (DebugDeoptimization && deopt) { 1331 tty->print_cr("[AFTER Deoptimization]"); 1332 trace_frames(); 1333 } 1334 } 1335 1336 1337 // Make zombies 1338 void JavaThread::make_zombies() { 1339 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) { 1340 if (fst.current()->can_be_deoptimized()) { 1341 // it is a Java nmethod 1342 nmethod* nm = CodeCache::find_nmethod(fst.current()->pc()); 1343 assert(nm != nullptr, "did not find nmethod"); 1344 nm->make_not_entrant(nmethod::InvalidationReason::ZOMBIE); 1345 } 1346 } 1347 } 1348 #endif // PRODUCT 1349 1350 1351 void JavaThread::deoptimize_marked_methods() { 1352 if (!has_last_Java_frame()) return; 1353 StackFrameStream fst(this, false /* update */, true /* process_frames */); 1354 for (; !fst.is_done(); fst.next()) { 1355 if (fst.current()->should_be_deoptimized()) { 1356 Deoptimization::deoptimize(this, *fst.current()); 1357 } 1358 } 1359 } 1360 1361 #ifdef ASSERT 1362 void JavaThread::verify_frame_info() { 1363 assert((!has_last_Java_frame() && java_call_counter() == 0) || 1364 (has_last_Java_frame() && java_call_counter() > 0), 1365 "unexpected frame info: has_last_frame=%s, java_call_counter=%d", 1366 has_last_Java_frame() ? "true" : "false", java_call_counter()); 1367 } 1368 #endif 1369 1370 // Push on a new block of JNI handles. 1371 void JavaThread::push_jni_handle_block() { 1372 // Allocate a new block for JNI handles. 1373 // Inlined code from jni_PushLocalFrame() 1374 JNIHandleBlock* old_handles = active_handles(); 1375 JNIHandleBlock* new_handles = JNIHandleBlock::allocate_block(this); 1376 assert(old_handles != nullptr && new_handles != nullptr, "should not be null"); 1377 new_handles->set_pop_frame_link(old_handles); // make sure java handles get gc'd. 1378 set_active_handles(new_handles); 1379 } 1380 1381 // Pop off the current block of JNI handles. 1382 void JavaThread::pop_jni_handle_block() { 1383 // Release our JNI handle block 1384 JNIHandleBlock* old_handles = active_handles(); 1385 JNIHandleBlock* new_handles = old_handles->pop_frame_link(); 1386 assert(new_handles != nullptr, "should never set active handles to null"); 1387 set_active_handles(new_handles); 1388 old_handles->set_pop_frame_link(nullptr); 1389 JNIHandleBlock::release_block(old_handles, this); 1390 } 1391 1392 void JavaThread::oops_do_no_frames(OopClosure* f, NMethodClosure* cf) { 1393 // Verify that the deferred card marks have been flushed. 1394 assert(deferred_card_mark().is_empty(), "Should be empty during GC"); 1395 1396 // Traverse the GCHandles 1397 Thread::oops_do_no_frames(f, cf); 1398 1399 if (active_handles() != nullptr) { 1400 active_handles()->oops_do(f); 1401 } 1402 1403 DEBUG_ONLY(verify_frame_info();) 1404 1405 assert(vframe_array_head() == nullptr, "deopt in progress at a safepoint!"); 1406 // If we have deferred set_locals there might be oops waiting to be 1407 // written 1408 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = JvmtiDeferredUpdates::deferred_locals(this); 1409 if (list != nullptr) { 1410 for (int i = 0; i < list->length(); i++) { 1411 list->at(i)->oops_do(f); 1412 } 1413 } 1414 1415 // Traverse instance variables at the end since the GC may be moving things 1416 // around using this function 1417 f->do_oop((oop*) &_vm_result_oop); 1418 f->do_oop((oop*) &_exception_oop); 1419 #if INCLUDE_JVMCI 1420 f->do_oop((oop*) &_jvmci_reserved_oop0); 1421 1422 if (_live_nmethod != nullptr && cf != nullptr) { 1423 cf->do_nmethod(_live_nmethod); 1424 } 1425 #endif 1426 1427 if (jvmti_thread_state() != nullptr) { 1428 jvmti_thread_state()->oops_do(f, cf); 1429 } 1430 1431 // The continuation oops are really on the stack. But there is typically at most 1432 // one of those per thread, so we handle them here in the oops_do_no_frames part 1433 // so that we don't have to sprinkle as many stack watermark checks where these 1434 // oops are used. We just need to make sure the thread has started processing. 1435 ContinuationEntry* entry = _cont_entry; 1436 while (entry != nullptr) { 1437 f->do_oop((oop*)entry->cont_addr()); 1438 f->do_oop((oop*)entry->chunk_addr()); 1439 entry = entry->parent(); 1440 } 1441 1442 // Due to lightweight locking 1443 lock_stack().oops_do(f); 1444 } 1445 1446 void JavaThread::oops_do_frames(OopClosure* f, NMethodClosure* cf) { 1447 if (!has_last_Java_frame()) { 1448 return; 1449 } 1450 // Finish any pending lazy GC activity for the frames 1451 StackWatermarkSet::finish_processing(this, nullptr /* context */, StackWatermarkKind::gc); 1452 // Traverse the execution stack 1453 for (StackFrameStream fst(this, true /* update */, false /* process_frames */); !fst.is_done(); fst.next()) { 1454 fst.current()->oops_do(f, cf, fst.register_map()); 1455 } 1456 } 1457 1458 #ifdef ASSERT 1459 void JavaThread::verify_states_for_handshake() { 1460 // This checks that the thread has a correct frame state during a handshake. 1461 verify_frame_info(); 1462 } 1463 #endif 1464 1465 void JavaThread::nmethods_do(NMethodClosure* cf) { 1466 DEBUG_ONLY(verify_frame_info();) 1467 MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXWrite, Thread::current());) 1468 1469 if (has_last_Java_frame()) { 1470 // Traverse the execution stack 1471 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) { 1472 fst.current()->nmethod_do(cf); 1473 } 1474 } 1475 1476 if (jvmti_thread_state() != nullptr) { 1477 jvmti_thread_state()->nmethods_do(cf); 1478 } 1479 1480 #if INCLUDE_JVMCI 1481 if (_live_nmethod != nullptr) { 1482 cf->do_nmethod(_live_nmethod); 1483 } 1484 #endif 1485 } 1486 1487 void JavaThread::metadata_do(MetadataClosure* f) { 1488 if (has_last_Java_frame()) { 1489 // Traverse the execution stack to call f() on the methods in the stack 1490 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) { 1491 fst.current()->metadata_do(f); 1492 } 1493 } else if (is_Compiler_thread()) { 1494 // need to walk ciMetadata in current compile tasks to keep alive. 1495 CompilerThread* ct = (CompilerThread*)this; 1496 if (ct->env() != nullptr) { 1497 ct->env()->metadata_do(f); 1498 } 1499 CompileTask* task = ct->task(); 1500 if (task != nullptr) { 1501 task->metadata_do(f); 1502 } 1503 } 1504 } 1505 1506 // Printing 1507 static const char* _get_thread_state_name(JavaThreadState _thread_state) { 1508 switch (_thread_state) { 1509 case _thread_uninitialized: return "_thread_uninitialized"; 1510 case _thread_new: return "_thread_new"; 1511 case _thread_new_trans: return "_thread_new_trans"; 1512 case _thread_in_native: return "_thread_in_native"; 1513 case _thread_in_native_trans: return "_thread_in_native_trans"; 1514 case _thread_in_vm: return "_thread_in_vm"; 1515 case _thread_in_vm_trans: return "_thread_in_vm_trans"; 1516 case _thread_in_Java: return "_thread_in_Java"; 1517 case _thread_in_Java_trans: return "_thread_in_Java_trans"; 1518 case _thread_blocked: return "_thread_blocked"; 1519 case _thread_blocked_trans: return "_thread_blocked_trans"; 1520 default: return "unknown thread state"; 1521 } 1522 } 1523 1524 void JavaThread::print_thread_state_on(outputStream *st) const { 1525 st->print_cr(" JavaThread state: %s", _get_thread_state_name(_thread_state)); 1526 } 1527 1528 // Called by Threads::print() for VM_PrintThreads operation 1529 void JavaThread::print_on(outputStream *st, bool print_extended_info) const { 1530 st->print_raw("\""); 1531 st->print_raw(name()); 1532 st->print_raw("\" "); 1533 oop thread_oop = threadObj(); 1534 if (thread_oop != nullptr) { 1535 st->print("#" INT64_FORMAT " [%ld] ", (int64_t)java_lang_Thread::thread_id(thread_oop), (long) osthread()->thread_id()); 1536 if (java_lang_Thread::is_daemon(thread_oop)) st->print("daemon "); 1537 st->print("prio=%d ", java_lang_Thread::priority(thread_oop)); 1538 } 1539 Thread::print_on(st, print_extended_info); 1540 // print guess for valid stack memory region (assume 4K pages); helps lock debugging 1541 st->print_cr("[" INTPTR_FORMAT "]", (intptr_t)last_Java_sp() & ~right_n_bits(12)); 1542 if (thread_oop != nullptr) { 1543 if (is_vthread_mounted()) { 1544 st->print_cr(" Carrying virtual thread #" INT64_FORMAT, java_lang_Thread::thread_id(vthread())); 1545 } else { 1546 st->print_cr(" java.lang.Thread.State: %s", java_lang_Thread::thread_status_name(thread_oop)); 1547 } 1548 } 1549 #ifndef PRODUCT 1550 _safepoint_state->print_on(st); 1551 #endif // PRODUCT 1552 if (is_Compiler_thread()) { 1553 CompileTask *task = ((CompilerThread*)this)->task(); 1554 if (task != nullptr) { 1555 st->print(" Compiling: "); 1556 task->print(st, nullptr, true, false); 1557 } else { 1558 st->print(" No compile task"); 1559 } 1560 st->cr(); 1561 } 1562 } 1563 1564 void JavaThread::print() const { print_on(tty); } 1565 1566 void JavaThread::print_name_on_error(outputStream* st, char *buf, int buflen) const { 1567 st->print("%s", get_thread_name_string(buf, buflen)); 1568 } 1569 1570 // Called by fatal error handler. The difference between this and 1571 // JavaThread::print() is that we can't grab lock or allocate memory. 1572 void JavaThread::print_on_error(outputStream* st, char *buf, int buflen) const { 1573 st->print("%s \"%s\"", type_name(), get_thread_name_string(buf, buflen)); 1574 Thread* current = Thread::current_or_null_safe(); 1575 assert(current != nullptr, "cannot be called by a detached thread"); 1576 st->fill_to(60); 1577 if (!current->is_Java_thread() || JavaThread::cast(current)->is_oop_safe()) { 1578 // Only access threadObj() if current thread is not a JavaThread 1579 // or if it is a JavaThread that can safely access oops. 1580 oop thread_obj = threadObj(); 1581 if (thread_obj != nullptr) { 1582 st->print(java_lang_Thread::is_daemon(thread_obj) ? " daemon" : " "); 1583 } 1584 } 1585 st->print(" ["); 1586 st->print("%s", _get_thread_state_name(_thread_state)); 1587 if (osthread()) { 1588 st->print(", id=%d", osthread()->thread_id()); 1589 } 1590 // Use raw field members for stack base/size as this could be 1591 // called before a thread has run enough to initialize them. 1592 st->print(", stack(" PTR_FORMAT "," PTR_FORMAT ") (" PROPERFMT ")", 1593 p2i(_stack_base - _stack_size), p2i(_stack_base), 1594 PROPERFMTARGS(_stack_size)); 1595 st->print("]"); 1596 1597 ThreadsSMRSupport::print_info_on(this, st); 1598 return; 1599 } 1600 1601 1602 // Verification 1603 1604 void JavaThread::frames_do(void f(frame*, const RegisterMap* map)) { 1605 // ignore if there is no stack 1606 if (!has_last_Java_frame()) return; 1607 // traverse the stack frames. Starts from top frame. 1608 for (StackFrameStream fst(this, true /* update_map */, true /* process_frames */, false /* walk_cont */); !fst.is_done(); fst.next()) { 1609 frame* fr = fst.current(); 1610 f(fr, fst.register_map()); 1611 } 1612 } 1613 1614 static void frame_verify(frame* f, const RegisterMap *map) { f->verify(map); } 1615 1616 void JavaThread::verify() { 1617 // Verify oops in the thread. 1618 oops_do(&VerifyOopClosure::verify_oop, nullptr); 1619 1620 // Verify the stack frames. 1621 frames_do(frame_verify); 1622 } 1623 1624 // CR 6300358 (sub-CR 2137150) 1625 // Most callers of this method assume that it can't return null but a 1626 // thread may not have a name whilst it is in the process of attaching to 1627 // the VM - see CR 6412693, and there are places where a JavaThread can be 1628 // seen prior to having its threadObj set (e.g., JNI attaching threads and 1629 // if vm exit occurs during initialization). These cases can all be accounted 1630 // for such that this method never returns null. 1631 const char* JavaThread::name() const { 1632 if (Thread::is_JavaThread_protected(/* target */ this)) { 1633 // The target JavaThread is protected so get_thread_name_string() is safe: 1634 return get_thread_name_string(); 1635 } 1636 1637 // The target JavaThread is not protected so we return the default: 1638 return Thread::name(); 1639 } 1640 1641 // Like name() but doesn't include the protection check. This must only be 1642 // called when it is known to be safe, even though the protection check can't tell 1643 // that e.g. when this thread is the init_thread() - see instanceKlass.cpp. 1644 const char* JavaThread::name_raw() const { 1645 return get_thread_name_string(); 1646 } 1647 1648 // Returns a non-null representation of this thread's name, or a suitable 1649 // descriptive string if there is no set name. 1650 const char* JavaThread::get_thread_name_string(char* buf, int buflen) const { 1651 const char* name_str; 1652 #ifdef ASSERT 1653 Thread* current = Thread::current_or_null_safe(); 1654 assert(current != nullptr, "cannot be called by a detached thread"); 1655 if (!current->is_Java_thread() || JavaThread::cast(current)->is_oop_safe()) { 1656 // Only access threadObj() if current thread is not a JavaThread 1657 // or if it is a JavaThread that can safely access oops. 1658 #endif 1659 oop thread_obj = threadObj(); 1660 if (thread_obj != nullptr) { 1661 oop name = java_lang_Thread::name(thread_obj); 1662 if (name != nullptr) { 1663 if (buf == nullptr) { 1664 name_str = java_lang_String::as_utf8_string(name); 1665 } else { 1666 name_str = java_lang_String::as_utf8_string(name, buf, buflen); 1667 } 1668 } else if (is_attaching_via_jni()) { // workaround for 6412693 - see 6404306 1669 name_str = "<no-name - thread is attaching>"; 1670 } else { 1671 name_str = "<un-named>"; 1672 } 1673 } else { 1674 name_str = Thread::name(); 1675 } 1676 #ifdef ASSERT 1677 } else { 1678 // Current JavaThread has exited... 1679 if (current == this) { 1680 // ... and is asking about itself: 1681 name_str = "<no-name - current JavaThread has exited>"; 1682 } else { 1683 // ... and it can't safely determine this JavaThread's name so 1684 // use the default thread name. 1685 name_str = Thread::name(); 1686 } 1687 } 1688 #endif 1689 assert(name_str != nullptr, "unexpected null thread name"); 1690 return name_str; 1691 } 1692 1693 // Helper to extract the name from the thread oop for logging. 1694 const char* JavaThread::name_for(oop thread_obj) { 1695 assert(thread_obj != nullptr, "precondition"); 1696 oop name = java_lang_Thread::name(thread_obj); 1697 const char* name_str; 1698 if (name != nullptr) { 1699 name_str = java_lang_String::as_utf8_string(name); 1700 } else { 1701 name_str = "<un-named>"; 1702 } 1703 return name_str; 1704 } 1705 1706 void JavaThread::prepare(jobject jni_thread, ThreadPriority prio) { 1707 1708 assert(Threads_lock->owner() == Thread::current(), "must have threads lock"); 1709 assert(NoPriority <= prio && prio <= MaxPriority, "sanity check"); 1710 // Link Java Thread object <-> C++ Thread 1711 1712 // Get the C++ thread object (an oop) from the JNI handle (a jthread) 1713 // and put it into a new Handle. The Handle "thread_oop" can then 1714 // be used to pass the C++ thread object to other methods. 1715 1716 // Set the Java level thread object (jthread) field of the 1717 // new thread (a JavaThread *) to C++ thread object using the 1718 // "thread_oop" handle. 1719 1720 // Set the thread field (a JavaThread *) of the 1721 // oop representing the java_lang_Thread to the new thread (a JavaThread *). 1722 1723 Handle thread_oop(Thread::current(), 1724 JNIHandles::resolve_non_null(jni_thread)); 1725 assert(InstanceKlass::cast(thread_oop->klass())->is_linked(), 1726 "must be initialized"); 1727 set_threadOopHandles(thread_oop()); 1728 set_monitor_owner_id(java_lang_Thread::thread_id(thread_oop())); 1729 1730 if (prio == NoPriority) { 1731 prio = java_lang_Thread::priority(thread_oop()); 1732 assert(prio != NoPriority, "A valid priority should be present"); 1733 } 1734 1735 // Push the Java priority down to the native thread; needs Threads_lock 1736 Thread::set_priority(this, prio); 1737 1738 // Add the new thread to the Threads list and set it in motion. 1739 // We must have threads lock in order to call Threads::add. 1740 // It is crucial that we do not block before the thread is 1741 // added to the Threads list for if a GC happens, then the java_thread oop 1742 // will not be visited by GC. 1743 Threads::add(this); 1744 // Publish the JavaThread* in java.lang.Thread after the JavaThread* is 1745 // on a ThreadsList. We don't want to wait for the release when the 1746 // Theads_lock is dropped somewhere in the caller since the JavaThread* 1747 // is already visible to JVM/TI via the ThreadsList. 1748 java_lang_Thread::release_set_thread(thread_oop(), this); 1749 } 1750 1751 oop JavaThread::current_park_blocker() { 1752 // Support for JSR-166 locks 1753 oop thread_oop = threadObj(); 1754 if (thread_oop != nullptr) { 1755 return java_lang_Thread::park_blocker(thread_oop); 1756 } 1757 return nullptr; 1758 } 1759 1760 // Print current stack trace for checked JNI warnings and JNI fatal errors. 1761 // This is the external format, selecting the platform or vthread 1762 // as applicable, and allowing for a native-only stack. 1763 void JavaThread::print_jni_stack() { 1764 assert(this == JavaThread::current(), "Can't print stack of other threads"); 1765 if (!has_last_Java_frame()) { 1766 ResourceMark rm(this); 1767 char* buf = NEW_RESOURCE_ARRAY_RETURN_NULL(char, O_BUFLEN); 1768 if (buf == nullptr) { 1769 tty->print_cr("Unable to print native stack - out of memory"); 1770 return; 1771 } 1772 NativeStackPrinter nsp(this); 1773 address lastpc = nullptr; 1774 nsp.print_stack(tty, buf, O_BUFLEN, lastpc, 1775 true /*print_source_info */, -1 /* max stack */ ); 1776 } else { 1777 print_active_stack_on(tty); 1778 } 1779 } 1780 1781 void JavaThread::print_stack_on(outputStream* st) { 1782 if (!has_last_Java_frame()) return; 1783 1784 Thread* current_thread = Thread::current(); 1785 ResourceMark rm(current_thread); 1786 HandleMark hm(current_thread); 1787 1788 RegisterMap reg_map(this, 1789 RegisterMap::UpdateMap::include, 1790 RegisterMap::ProcessFrames::include, 1791 RegisterMap::WalkContinuation::skip); 1792 vframe* start_vf = platform_thread_last_java_vframe(®_map); 1793 int count = 0; 1794 for (vframe* f = start_vf; f != nullptr; f = f->sender()) { 1795 if (f->is_java_frame()) { 1796 javaVFrame* jvf = javaVFrame::cast(f); 1797 java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci()); 1798 1799 // Print out lock information 1800 if (JavaMonitorsInStackTrace) { 1801 jvf->print_lock_info_on(st, false/*is_virtual*/, count); 1802 } 1803 } else { 1804 // Ignore non-Java frames 1805 } 1806 1807 // Bail-out case for too deep stacks if MaxJavaStackTraceDepth > 0 1808 count++; 1809 if (MaxJavaStackTraceDepth > 0 && MaxJavaStackTraceDepth == count) return; 1810 } 1811 } 1812 1813 void JavaThread::print_vthread_stack_on(outputStream* st) { 1814 assert(is_vthread_mounted(), "Caller should have checked this"); 1815 assert(has_last_Java_frame(), "must be"); 1816 1817 Thread* current_thread = Thread::current(); 1818 ResourceMark rm(current_thread); 1819 HandleMark hm(current_thread); 1820 1821 RegisterMap reg_map(this, 1822 RegisterMap::UpdateMap::include, 1823 RegisterMap::ProcessFrames::include, 1824 RegisterMap::WalkContinuation::include); 1825 ContinuationEntry* cont_entry = last_continuation(); 1826 vframe* start_vf = last_java_vframe(®_map); 1827 int count = 0; 1828 for (vframe* f = start_vf; f != nullptr; f = f->sender()) { 1829 // Watch for end of vthread stack 1830 if (Continuation::is_continuation_enterSpecial(f->fr())) { 1831 assert(cont_entry == Continuation::get_continuation_entry_for_entry_frame(this, f->fr()), ""); 1832 if (cont_entry->is_virtual_thread()) { 1833 break; 1834 } 1835 cont_entry = cont_entry->parent(); 1836 } 1837 if (f->is_java_frame()) { 1838 javaVFrame* jvf = javaVFrame::cast(f); 1839 java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci()); 1840 1841 // Print out lock information 1842 if (JavaMonitorsInStackTrace) { 1843 jvf->print_lock_info_on(st, true/*is_virtual*/, count); 1844 } 1845 } else { 1846 // Ignore non-Java frames 1847 } 1848 1849 // Bail-out case for too deep stacks if MaxJavaStackTraceDepth > 0 1850 count++; 1851 if (MaxJavaStackTraceDepth > 0 && MaxJavaStackTraceDepth == count) return; 1852 } 1853 } 1854 1855 void JavaThread::print_active_stack_on(outputStream* st) { 1856 if (is_vthread_mounted()) { 1857 print_vthread_stack_on(st); 1858 } else { 1859 print_stack_on(st); 1860 } 1861 } 1862 1863 #if INCLUDE_JVMTI 1864 // Rebind JVMTI thread state from carrier to virtual or from virtual to carrier. 1865 JvmtiThreadState* JavaThread::rebind_to_jvmti_thread_state_of(oop thread_oop) { 1866 set_jvmti_vthread(thread_oop); 1867 1868 // unbind current JvmtiThreadState from JavaThread 1869 JvmtiThreadState::unbind_from(jvmti_thread_state(), this); 1870 1871 // bind new JvmtiThreadState to JavaThread 1872 JvmtiThreadState::bind_to(java_lang_Thread::jvmti_thread_state(thread_oop), this); 1873 1874 // enable interp_only_mode for virtual or carrier thread if it has pending bit 1875 JvmtiThreadState::process_pending_interp_only(this); 1876 1877 return jvmti_thread_state(); 1878 } 1879 #endif 1880 1881 // JVMTI PopFrame support 1882 void JavaThread::popframe_preserve_args(ByteSize size_in_bytes, void* start) { 1883 assert(_popframe_preserved_args == nullptr, "should not wipe out old PopFrame preserved arguments"); 1884 if (in_bytes(size_in_bytes) != 0) { 1885 _popframe_preserved_args = NEW_C_HEAP_ARRAY(char, in_bytes(size_in_bytes), mtThread); 1886 _popframe_preserved_args_size = in_bytes(size_in_bytes); 1887 Copy::conjoint_jbytes(start, _popframe_preserved_args, _popframe_preserved_args_size); 1888 } 1889 } 1890 1891 void* JavaThread::popframe_preserved_args() { 1892 return _popframe_preserved_args; 1893 } 1894 1895 ByteSize JavaThread::popframe_preserved_args_size() { 1896 return in_ByteSize(_popframe_preserved_args_size); 1897 } 1898 1899 WordSize JavaThread::popframe_preserved_args_size_in_words() { 1900 int sz = in_bytes(popframe_preserved_args_size()); 1901 assert(sz % wordSize == 0, "argument size must be multiple of wordSize"); 1902 return in_WordSize(sz / wordSize); 1903 } 1904 1905 void JavaThread::popframe_free_preserved_args() { 1906 assert(_popframe_preserved_args != nullptr, "should not free PopFrame preserved arguments twice"); 1907 FREE_C_HEAP_ARRAY(char, (char*)_popframe_preserved_args); 1908 _popframe_preserved_args = nullptr; 1909 _popframe_preserved_args_size = 0; 1910 } 1911 1912 #ifndef PRODUCT 1913 1914 void JavaThread::trace_frames() { 1915 tty->print_cr("[Describe stack]"); 1916 int frame_no = 1; 1917 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) { 1918 tty->print(" %d. ", frame_no++); 1919 fst.current()->print_value_on(tty); 1920 tty->cr(); 1921 } 1922 } 1923 1924 class PrintAndVerifyOopClosure: public OopClosure { 1925 protected: 1926 template <class T> inline void do_oop_work(T* p) { 1927 oop obj = RawAccess<>::oop_load(p); 1928 if (obj == nullptr) return; 1929 tty->print(INTPTR_FORMAT ": ", p2i(p)); 1930 if (oopDesc::is_oop_or_null(obj)) { 1931 if (obj->is_objArray()) { 1932 tty->print_cr("valid objArray: " INTPTR_FORMAT, p2i(obj)); 1933 } else { 1934 obj->print(); 1935 } 1936 } else { 1937 tty->print_cr("invalid oop: " INTPTR_FORMAT, p2i(obj)); 1938 } 1939 tty->cr(); 1940 } 1941 public: 1942 virtual void do_oop(oop* p) { do_oop_work(p); } 1943 virtual void do_oop(narrowOop* p) { do_oop_work(p); } 1944 }; 1945 1946 #ifdef ASSERT 1947 // Print or validate the layout of stack frames 1948 void JavaThread::print_frame_layout(int depth, bool validate_only) { 1949 ResourceMark rm; 1950 PreserveExceptionMark pm(this); 1951 FrameValues values; 1952 int frame_no = 0; 1953 for (StackFrameStream fst(this, true, true, true); !fst.is_done(); fst.next()) { 1954 fst.current()->describe(values, ++frame_no, fst.register_map()); 1955 if (depth == frame_no) break; 1956 } 1957 Continuation::describe(values); 1958 if (validate_only) { 1959 values.validate(); 1960 } else { 1961 tty->print_cr("[Describe stack layout]"); 1962 values.print(this); 1963 } 1964 } 1965 #endif 1966 1967 void JavaThread::trace_stack_from(vframe* start_vf) { 1968 ResourceMark rm; 1969 int vframe_no = 1; 1970 for (vframe* f = start_vf; f; f = f->sender()) { 1971 if (f->is_java_frame()) { 1972 javaVFrame::cast(f)->print_activation(vframe_no++); 1973 } else { 1974 f->print(); 1975 } 1976 if (vframe_no > StackPrintLimit) { 1977 tty->print_cr("...<more frames>..."); 1978 return; 1979 } 1980 } 1981 } 1982 1983 1984 void JavaThread::trace_stack() { 1985 if (!has_last_Java_frame()) return; 1986 Thread* current_thread = Thread::current(); 1987 ResourceMark rm(current_thread); 1988 HandleMark hm(current_thread); 1989 RegisterMap reg_map(this, 1990 RegisterMap::UpdateMap::include, 1991 RegisterMap::ProcessFrames::include, 1992 RegisterMap::WalkContinuation::skip); 1993 trace_stack_from(last_java_vframe(®_map)); 1994 } 1995 1996 1997 #endif // PRODUCT 1998 1999 // Slow-path increment of the held monitor counts. JNI locking is always 2000 // this slow-path. 2001 void JavaThread::inc_held_monitor_count(intx i, bool jni) { 2002 #ifdef SUPPORT_MONITOR_COUNT 2003 // Nothing to do. Just do some sanity check. 2004 assert(_held_monitor_count == 0, "counter should not be used"); 2005 assert(_jni_monitor_count == 0, "counter should not be used"); 2006 #endif // SUPPORT_MONITOR_COUNT 2007 } 2008 2009 // Slow-path decrement of the held monitor counts. JNI unlocking is always 2010 // this slow-path. 2011 void JavaThread::dec_held_monitor_count(intx i, bool jni) { 2012 #ifdef SUPPORT_MONITOR_COUNT 2013 // Nothing to do. Just do some sanity check. 2014 assert(_held_monitor_count == 0, "counter should not be used"); 2015 assert(_jni_monitor_count == 0, "counter should not be used"); 2016 #endif // SUPPORT_MONITOR_COUNT 2017 } 2018 2019 frame JavaThread::vthread_last_frame() { 2020 assert (is_vthread_mounted(), "Virtual thread not mounted"); 2021 return last_frame(); 2022 } 2023 2024 frame JavaThread::carrier_last_frame(RegisterMap* reg_map) { 2025 const ContinuationEntry* entry = vthread_continuation(); 2026 guarantee (entry != nullptr, "Not a carrier thread"); 2027 frame f = entry->to_frame(); 2028 if (reg_map->process_frames()) { 2029 entry->flush_stack_processing(this); 2030 } 2031 entry->update_register_map(reg_map); 2032 return f.sender(reg_map); 2033 } 2034 2035 frame JavaThread::platform_thread_last_frame(RegisterMap* reg_map) { 2036 return is_vthread_mounted() ? carrier_last_frame(reg_map) : last_frame(); 2037 } 2038 2039 javaVFrame* JavaThread::last_java_vframe(const frame f, RegisterMap *reg_map) { 2040 assert(reg_map != nullptr, "a map must be given"); 2041 for (vframe* vf = vframe::new_vframe(&f, reg_map, this); vf; vf = vf->sender()) { 2042 if (vf->is_java_frame()) return javaVFrame::cast(vf); 2043 } 2044 return nullptr; 2045 } 2046 2047 Klass* JavaThread::security_get_caller_class(int depth) { 2048 ResetNoHandleMark rnhm; 2049 HandleMark hm(Thread::current()); 2050 2051 vframeStream vfst(this); 2052 vfst.security_get_caller_frame(depth); 2053 if (!vfst.at_end()) { 2054 return vfst.method()->method_holder(); 2055 } 2056 return nullptr; 2057 } 2058 2059 // Internal convenience function for millisecond resolution sleeps. 2060 bool JavaThread::sleep(jlong millis) { 2061 jlong nanos; 2062 if (millis > max_jlong / NANOUNITS_PER_MILLIUNIT) { 2063 // Conversion to nanos would overflow, saturate at max 2064 nanos = max_jlong; 2065 } else { 2066 nanos = millis * NANOUNITS_PER_MILLIUNIT; 2067 } 2068 return sleep_nanos(nanos); 2069 } 2070 2071 // java.lang.Thread.sleep support 2072 // Returns true if sleep time elapsed as expected, and false 2073 // if the thread was interrupted or async exception was installed. 2074 bool JavaThread::sleep_nanos(jlong nanos) { 2075 assert(this == Thread::current(), "thread consistency check"); 2076 assert(nanos >= 0, "nanos are in range"); 2077 2078 ParkEvent * const slp = this->_SleepEvent; 2079 // Because there can be races with thread interruption sending an unpark() 2080 // to the event, we explicitly reset it here to avoid an immediate return. 2081 // The actual interrupt state will be checked before we park(). 2082 slp->reset(); 2083 // Thread interruption establishes a happens-before ordering in the 2084 // Java Memory Model, so we need to ensure we synchronize with the 2085 // interrupt state. 2086 OrderAccess::fence(); 2087 2088 jlong prevtime = os::javaTimeNanos(); 2089 2090 jlong nanos_remaining = nanos; 2091 2092 for (;;) { 2093 if (has_async_exception_condition()) { 2094 return false; 2095 } 2096 // interruption has precedence over timing out 2097 if (this->is_interrupted(true)) { 2098 return false; 2099 } 2100 2101 if (nanos_remaining <= 0) { 2102 return true; 2103 } 2104 2105 { 2106 ThreadBlockInVM tbivm(this); 2107 OSThreadWaitState osts(this->osthread(), false /* not Object.wait() */); 2108 slp->park_nanos(nanos_remaining); 2109 } 2110 2111 // Update elapsed time tracking 2112 jlong newtime = os::javaTimeNanos(); 2113 if (newtime - prevtime < 0) { 2114 // time moving backwards, should only happen if no monotonic clock 2115 // not a guarantee() because JVM should not abort on kernel/glibc bugs 2116 assert(false, 2117 "unexpected time moving backwards detected in JavaThread::sleep()"); 2118 } else { 2119 nanos_remaining -= (newtime - prevtime); 2120 } 2121 prevtime = newtime; 2122 } 2123 } 2124 2125 // Last thread running calls java.lang.Shutdown.shutdown() 2126 void JavaThread::invoke_shutdown_hooks() { 2127 HandleMark hm(this); 2128 2129 // We could get here with a pending exception, if so clear it now. 2130 if (this->has_pending_exception()) { 2131 this->clear_pending_exception(); 2132 } 2133 2134 EXCEPTION_MARK; 2135 Klass* shutdown_klass = 2136 SystemDictionary::resolve_or_null(vmSymbols::java_lang_Shutdown(), 2137 THREAD); 2138 if (shutdown_klass != nullptr) { 2139 // SystemDictionary::resolve_or_null will return null if there was 2140 // an exception. If we cannot load the Shutdown class, just don't 2141 // call Shutdown.shutdown() at all. This will mean the shutdown hooks 2142 // won't be run. Note that if a shutdown hook was registered, 2143 // the Shutdown class would have already been loaded 2144 // (Runtime.addShutdownHook will load it). 2145 JavaValue result(T_VOID); 2146 JavaCalls::call_static(&result, 2147 shutdown_klass, 2148 vmSymbols::shutdown_name(), 2149 vmSymbols::void_method_signature(), 2150 THREAD); 2151 } 2152 CLEAR_PENDING_EXCEPTION; 2153 } 2154 2155 #ifndef PRODUCT 2156 void JavaThread::verify_cross_modify_fence_failure(JavaThread *thread) { 2157 report_vm_error(__FILE__, __LINE__, "Cross modify fence failure", "%p", thread); 2158 } 2159 #endif 2160 2161 // Helper function to create the java.lang.Thread object for a 2162 // VM-internal thread. The thread will have the given name, and be 2163 // a member of the "system" ThreadGroup. 2164 Handle JavaThread::create_system_thread_object(const char* name, TRAPS) { 2165 Handle string = java_lang_String::create_from_str(name, CHECK_NH); 2166 2167 // Initialize thread_oop to put it into the system threadGroup. 2168 // This is done by calling the Thread(ThreadGroup group, String name) constructor. 2169 Handle thread_group(THREAD, Universe::system_thread_group()); 2170 Handle thread_oop = 2171 JavaCalls::construct_new_instance(vmClasses::Thread_klass(), 2172 vmSymbols::threadgroup_string_void_signature(), 2173 thread_group, 2174 string, 2175 CHECK_NH); 2176 2177 return thread_oop; 2178 } 2179 2180 // Starts the target JavaThread as a daemon of the given priority, and 2181 // bound to the given java.lang.Thread instance. 2182 // The Threads_lock is held for the duration. 2183 void JavaThread::start_internal_daemon(JavaThread* current, JavaThread* target, 2184 Handle thread_oop, ThreadPriority prio) { 2185 2186 assert(target->osthread() != nullptr, "target thread is not properly initialized"); 2187 2188 MutexLocker mu(current, Threads_lock); 2189 2190 // Initialize the fields of the thread_oop first. 2191 if (prio != NoPriority) { 2192 java_lang_Thread::set_priority(thread_oop(), prio); 2193 // Note: we don't call os::set_priority here. Possibly we should, 2194 // else all threads should call it themselves when they first run. 2195 } 2196 2197 java_lang_Thread::set_daemon(thread_oop()); 2198 2199 // Now bind the thread_oop to the target JavaThread. 2200 target->set_threadOopHandles(thread_oop()); 2201 target->set_monitor_owner_id(java_lang_Thread::thread_id(thread_oop())); 2202 2203 Threads::add(target); // target is now visible for safepoint/handshake 2204 // Publish the JavaThread* in java.lang.Thread after the JavaThread* is 2205 // on a ThreadsList. We don't want to wait for the release when the 2206 // Theads_lock is dropped when the 'mu' destructor is run since the 2207 // JavaThread* is already visible to JVM/TI via the ThreadsList. 2208 2209 assert(java_lang_Thread::thread(thread_oop()) == nullptr, "must not be alive"); 2210 java_lang_Thread::release_set_thread(thread_oop(), target); // isAlive == true now 2211 Thread::start(target); 2212 } 2213 2214 void JavaThread::vm_exit_on_osthread_failure(JavaThread* thread) { 2215 // At this point it may be possible that no osthread was created for the 2216 // JavaThread due to lack of resources. However, since this must work 2217 // for critical system threads just check and abort if this fails. 2218 if (thread->osthread() == nullptr) { 2219 // This isn't really an OOM condition, but historically this is what 2220 // we report. 2221 vm_exit_during_initialization("java.lang.OutOfMemoryError", 2222 os::native_thread_creation_failed_msg()); 2223 } 2224 } 2225 2226 void JavaThread::pretouch_stack() { 2227 // Given an established java thread stack with usable area followed by 2228 // shadow zone and reserved/yellow/red zone, pretouch the usable area ranging 2229 // from the current frame down to the start of the shadow zone. 2230 const address end = _stack_overflow_state.shadow_zone_safe_limit(); 2231 if (is_in_full_stack(end)) { 2232 char* p1 = (char*) alloca(1); 2233 address here = (address) &p1; 2234 if (is_in_full_stack(here) && here > end) { 2235 size_t to_alloc = here - end; 2236 char* p2 = (char*) alloca(to_alloc); 2237 log_trace(os, thread)("Pretouching thread stack for %zu: " RANGEFMT ".", 2238 (uintx) osthread()->thread_id(), RANGEFMTARGS(p2, to_alloc)); 2239 os::pretouch_memory(p2, p2 + to_alloc, 2240 NOT_AIX(os::vm_page_size()) AIX_ONLY(4096)); 2241 } 2242 } 2243 } 2244 2245 // Deferred OopHandle release support. 2246 2247 class OopHandleList : public CHeapObj<mtInternal> { 2248 static const int _count = 4; 2249 OopHandle _handles[_count]; 2250 OopHandleList* _next; 2251 int _index; 2252 public: 2253 OopHandleList(OopHandleList* next) : _next(next), _index(0) {} 2254 void add(OopHandle h) { 2255 assert(_index < _count, "too many additions"); 2256 _handles[_index++] = h; 2257 } 2258 ~OopHandleList() { 2259 assert(_index == _count, "usage error"); 2260 for (int i = 0; i < _index; i++) { 2261 _handles[i].release(JavaThread::thread_oop_storage()); 2262 } 2263 } 2264 OopHandleList* next() const { return _next; } 2265 }; 2266 2267 OopHandleList* JavaThread::_oop_handle_list = nullptr; 2268 2269 // Called by the ServiceThread to do the work of releasing 2270 // the OopHandles. 2271 void JavaThread::release_oop_handles() { 2272 OopHandleList* list; 2273 { 2274 MutexLocker ml(Service_lock, Mutex::_no_safepoint_check_flag); 2275 list = _oop_handle_list; 2276 _oop_handle_list = nullptr; 2277 } 2278 assert(!SafepointSynchronize::is_at_safepoint(), "cannot be called at a safepoint"); 2279 2280 while (list != nullptr) { 2281 OopHandleList* l = list; 2282 list = l->next(); 2283 delete l; 2284 } 2285 } 2286 2287 // Add our OopHandles for later release. 2288 void JavaThread::add_oop_handles_for_release() { 2289 MutexLocker ml(Service_lock, Mutex::_no_safepoint_check_flag); 2290 OopHandleList* new_head = new OopHandleList(_oop_handle_list); 2291 new_head->add(_threadObj); 2292 new_head->add(_vthread); 2293 new_head->add(_jvmti_vthread); 2294 new_head->add(_scopedValueCache); 2295 _oop_handle_list = new_head; 2296 Service_lock->notify_all(); 2297 } 2298 2299 #if INCLUDE_JFR 2300 void JavaThread::set_last_freeze_fail_result(freeze_result result) { 2301 assert(result != freeze_ok, "sanity check"); 2302 _last_freeze_fail_result = result; 2303 _last_freeze_fail_time = Ticks::now(); 2304 } 2305 2306 // Post jdk.VirtualThreadPinned event 2307 void JavaThread::post_vthread_pinned_event(EventVirtualThreadPinned* event, const char* op, freeze_result result) { 2308 assert(result != freeze_ok, "sanity check"); 2309 if (event->should_commit()) { 2310 char reason[256]; 2311 if (class_to_be_initialized() != nullptr) { 2312 ResourceMark rm(this); 2313 jio_snprintf(reason, sizeof reason, "Waited for initialization of %s by another thread", 2314 class_to_be_initialized()->external_name()); 2315 event->set_pinnedReason(reason); 2316 } else if (class_being_initialized() != nullptr) { 2317 ResourceMark rm(this); 2318 jio_snprintf(reason, sizeof(reason), "VM call to %s.<clinit> on stack", 2319 class_being_initialized()->external_name()); 2320 event->set_pinnedReason(reason); 2321 } else if (result == freeze_pinned_native) { 2322 event->set_pinnedReason("Native or VM frame on stack"); 2323 } else { 2324 jio_snprintf(reason, sizeof(reason), "Freeze or preempt failed (%d)", result); 2325 event->set_pinnedReason(reason); 2326 } 2327 event->set_blockingOperation(op); 2328 event->set_carrierThread(JFR_JVM_THREAD_ID(this)); 2329 event->commit(); 2330 } 2331 } 2332 #endif