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/dynamicArchive.hpp" 28 #include "ci/ciEnv.hpp" 29 #include "classfile/javaClasses.inline.hpp" 30 #include "classfile/javaThreadStatus.hpp" 31 #include "classfile/systemDictionary.hpp" 32 #include "classfile/vmClasses.hpp" 33 #include "classfile/vmSymbols.hpp" 34 #include "code/codeCache.hpp" 35 #include "code/scopeDesc.hpp" 36 #include "compiler/compileTask.hpp" 37 #include "compiler/compilerThread.hpp" 38 #include "gc/shared/oopStorage.hpp" 39 #include "gc/shared/oopStorageSet.hpp" 40 #include "gc/shared/tlab_globals.hpp" 41 #include "jfr/jfrEvents.hpp" 42 #include "jvm.h" 43 #include "jvmtifiles/jvmtiEnv.hpp" 44 #include "logging/log.hpp" 45 #include "logging/logAsyncWriter.hpp" 46 #include "logging/logStream.hpp" 47 #include "memory/allocation.inline.hpp" 48 #include "memory/iterator.hpp" 49 #include "memory/universe.hpp" 50 #include "oops/access.inline.hpp" 51 #include "oops/inlineKlass.hpp" 52 #include "oops/instanceKlass.hpp" 53 #include "oops/klass.inline.hpp" 54 #include "oops/oop.inline.hpp" 55 #include "oops/oopHandle.inline.hpp" 56 #include "oops/verifyOopClosure.hpp" 57 #include "prims/jvm_misc.hpp" 58 #include "prims/jvmtiDeferredUpdates.hpp" 59 #include "prims/jvmtiExport.hpp" 60 #include "prims/jvmtiThreadState.inline.hpp" 61 #include "runtime/atomic.hpp" 62 #include "runtime/continuation.hpp" 63 #include "runtime/continuationEntry.inline.hpp" 64 #include "runtime/continuationHelper.inline.hpp" 65 #include "runtime/deoptimization.hpp" 66 #include "runtime/frame.inline.hpp" 67 #include "runtime/handles.inline.hpp" 68 #include "runtime/handshake.hpp" 69 #include "runtime/interfaceSupport.inline.hpp" 70 #include "runtime/java.hpp" 71 #include "runtime/javaCalls.hpp" 72 #include "runtime/javaThread.inline.hpp" 73 #include "runtime/jniHandles.inline.hpp" 74 #include "runtime/lockStack.inline.hpp" 75 #include "runtime/mutexLocker.hpp" 76 #include "runtime/orderAccess.hpp" 77 #include "runtime/os.inline.hpp" 78 #include "runtime/osThread.hpp" 79 #include "runtime/safepoint.hpp" 80 #include "runtime/safepointMechanism.inline.hpp" 81 #include "runtime/safepointVerifiers.hpp" 82 #include "runtime/serviceThread.hpp" 83 #include "runtime/stackFrameStream.inline.hpp" 84 #include "runtime/stackWatermarkSet.hpp" 85 #include "runtime/synchronizer.hpp" 86 #include "runtime/threadCritical.hpp" 87 #include "runtime/threadSMR.inline.hpp" 88 #include "runtime/threadStatisticalInfo.hpp" 89 #include "runtime/threadWXSetters.inline.hpp" 90 #include "runtime/timer.hpp" 91 #include "runtime/timerTrace.hpp" 92 #include "runtime/vframe.inline.hpp" 93 #include "runtime/vframeArray.hpp" 94 #include "runtime/vframe_hp.hpp" 95 #include "runtime/vmThread.hpp" 96 #include "runtime/vmOperations.hpp" 97 #include "services/threadService.hpp" 98 #include "utilities/copy.hpp" 99 #include "utilities/defaultStream.hpp" 100 #include "utilities/dtrace.hpp" 101 #include "utilities/events.hpp" 102 #include "utilities/macros.hpp" 103 #include "utilities/preserveException.hpp" 104 #include "utilities/spinYield.hpp" 105 #include "utilities/vmError.hpp" 106 #if INCLUDE_JVMCI 107 #include "jvmci/jvmci.hpp" 108 #include "jvmci/jvmciEnv.hpp" 109 #endif 110 #if INCLUDE_JFR 111 #include "jfr/jfr.hpp" 112 #endif 113 114 // Set by os layer. 115 size_t JavaThread::_stack_size_at_create = 0; 116 117 #ifdef DTRACE_ENABLED 118 119 // Only bother with this argument setup if dtrace is available 120 121 #define HOTSPOT_THREAD_PROBE_start HOTSPOT_THREAD_START 122 #define HOTSPOT_THREAD_PROBE_stop HOTSPOT_THREAD_STOP 123 124 #define DTRACE_THREAD_PROBE(probe, javathread) \ 125 { \ 126 ResourceMark rm(this); \ 127 int len = 0; \ 128 const char* name = (javathread)->name(); \ 129 len = strlen(name); \ 130 HOTSPOT_THREAD_PROBE_##probe(/* probe = start, stop */ \ 131 (char *) name, len, \ 132 java_lang_Thread::thread_id((javathread)->threadObj()), \ 133 (uintptr_t) (javathread)->osthread()->thread_id(), \ 134 java_lang_Thread::is_daemon((javathread)->threadObj())); \ 135 } 136 137 #else // ndef DTRACE_ENABLED 138 139 #define DTRACE_THREAD_PROBE(probe, javathread) 140 141 #endif // ndef DTRACE_ENABLED 142 143 void JavaThread::smr_delete() { 144 if (_on_thread_list) { 145 ThreadsSMRSupport::smr_delete(this); 146 } else { 147 delete this; 148 } 149 } 150 151 // Initialized by VMThread at vm_global_init 152 OopStorage* JavaThread::_thread_oop_storage = nullptr; 153 154 OopStorage* JavaThread::thread_oop_storage() { 155 assert(_thread_oop_storage != nullptr, "not yet initialized"); 156 return _thread_oop_storage; 157 } 158 159 void JavaThread::set_threadOopHandles(oop p) { 160 assert(_thread_oop_storage != nullptr, "not yet initialized"); 161 _threadObj = OopHandle(_thread_oop_storage, p); 162 _vthread = OopHandle(_thread_oop_storage, p); 163 _jvmti_vthread = OopHandle(_thread_oop_storage, p->is_a(vmClasses::BoundVirtualThread_klass()) ? p : nullptr); 164 _scopedValueCache = OopHandle(_thread_oop_storage, nullptr); 165 } 166 167 oop JavaThread::threadObj() const { 168 // Ideally we would verify the current thread is oop_safe when this is called, but as we can 169 // be called from a signal handler we would have to use Thread::current_or_null_safe(). That 170 // has overhead and also interacts poorly with GetLastError on Windows due to the use of TLS. 171 // Instead callers must verify oop safe access. 172 return _threadObj.resolve(); 173 } 174 175 oop JavaThread::vthread() const { 176 return _vthread.resolve(); 177 } 178 179 void JavaThread::set_vthread(oop p) { 180 assert(_thread_oop_storage != nullptr, "not yet initialized"); 181 _vthread.replace(p); 182 } 183 184 oop JavaThread::jvmti_vthread() const { 185 return _jvmti_vthread.resolve(); 186 } 187 188 void JavaThread::set_jvmti_vthread(oop p) { 189 assert(_thread_oop_storage != nullptr, "not yet initialized"); 190 _jvmti_vthread.replace(p); 191 } 192 193 oop JavaThread::scopedValueCache() const { 194 return _scopedValueCache.resolve(); 195 } 196 197 void JavaThread::set_scopedValueCache(oop p) { 198 if (_scopedValueCache.ptr_raw() != nullptr) { // i.e. if the OopHandle has been allocated 199 _scopedValueCache.replace(p); 200 } else { 201 assert(p == nullptr, "not yet initialized"); 202 } 203 } 204 205 void JavaThread::clear_scopedValueBindings() { 206 set_scopedValueCache(nullptr); 207 oop vthread_oop = vthread(); 208 // vthread may be null here if we get a VM error during startup, 209 // before the java.lang.Thread instance has been created. 210 if (vthread_oop != nullptr) { 211 java_lang_Thread::clear_scopedValueBindings(vthread_oop); 212 } 213 } 214 215 void JavaThread::allocate_threadObj(Handle thread_group, const char* thread_name, 216 bool daemon, TRAPS) { 217 assert(thread_group.not_null(), "thread group should be specified"); 218 assert(threadObj() == nullptr, "should only create Java thread object once"); 219 220 InstanceKlass* ik = vmClasses::Thread_klass(); 221 assert(ik->is_initialized(), "must be"); 222 instanceHandle thread_oop = ik->allocate_instance_handle(CHECK); 223 224 // We are called from jni_AttachCurrentThread/jni_AttachCurrentThreadAsDaemon. 225 // We cannot use JavaCalls::construct_new_instance because the java.lang.Thread 226 // constructor calls Thread.current(), which must be set here. 227 java_lang_Thread::set_thread(thread_oop(), this); 228 set_threadOopHandles(thread_oop()); 229 230 JavaValue result(T_VOID); 231 if (thread_name != nullptr) { 232 Handle name = java_lang_String::create_from_str(thread_name, CHECK); 233 // Thread gets assigned specified name and null target 234 JavaCalls::call_special(&result, 235 thread_oop, 236 ik, 237 vmSymbols::object_initializer_name(), 238 vmSymbols::threadgroup_string_void_signature(), 239 thread_group, 240 name, 241 CHECK); 242 } else { 243 // Thread gets assigned name "Thread-nnn" and null target 244 // (java.lang.Thread doesn't have a constructor taking only a ThreadGroup argument) 245 JavaCalls::call_special(&result, 246 thread_oop, 247 ik, 248 vmSymbols::object_initializer_name(), 249 vmSymbols::threadgroup_runnable_void_signature(), 250 thread_group, 251 Handle(), 252 CHECK); 253 } 254 os::set_priority(this, NormPriority); 255 256 if (daemon) { 257 java_lang_Thread::set_daemon(thread_oop()); 258 } 259 } 260 261 // ======= JavaThread ======== 262 263 #if INCLUDE_JVMCI 264 265 jlong* JavaThread::_jvmci_old_thread_counters; 266 267 bool jvmci_counters_include(JavaThread* thread) { 268 return !JVMCICountersExcludeCompiler || !thread->is_Compiler_thread(); 269 } 270 271 void JavaThread::collect_counters(jlong* array, int length) { 272 assert(length == JVMCICounterSize, "wrong value"); 273 for (int i = 0; i < length; i++) { 274 array[i] = _jvmci_old_thread_counters[i]; 275 } 276 for (JavaThread* tp : ThreadsListHandle()) { 277 if (jvmci_counters_include(tp)) { 278 for (int i = 0; i < length; i++) { 279 array[i] += tp->_jvmci_counters[i]; 280 } 281 } 282 } 283 } 284 285 // Attempt to enlarge the array for per thread counters. 286 jlong* resize_counters_array(jlong* old_counters, int current_size, int new_size) { 287 jlong* new_counters = NEW_C_HEAP_ARRAY_RETURN_NULL(jlong, new_size, mtJVMCI); 288 if (new_counters == nullptr) { 289 return nullptr; 290 } 291 if (old_counters == nullptr) { 292 old_counters = new_counters; 293 memset(old_counters, 0, sizeof(jlong) * new_size); 294 } else { 295 for (int i = 0; i < MIN2((int) current_size, new_size); i++) { 296 new_counters[i] = old_counters[i]; 297 } 298 if (new_size > current_size) { 299 memset(new_counters + current_size, 0, sizeof(jlong) * (new_size - current_size)); 300 } 301 FREE_C_HEAP_ARRAY(jlong, old_counters); 302 } 303 return new_counters; 304 } 305 306 // Attempt to enlarge the array for per thread counters. 307 bool JavaThread::resize_counters(int current_size, int new_size) { 308 jlong* new_counters = resize_counters_array(_jvmci_counters, current_size, new_size); 309 if (new_counters == nullptr) { 310 return false; 311 } else { 312 _jvmci_counters = new_counters; 313 return true; 314 } 315 } 316 317 class VM_JVMCIResizeCounters : public VM_Operation { 318 private: 319 int _new_size; 320 bool _failed; 321 322 public: 323 VM_JVMCIResizeCounters(int new_size) : _new_size(new_size), _failed(false) { } 324 VMOp_Type type() const { return VMOp_JVMCIResizeCounters; } 325 bool allow_nested_vm_operations() const { return true; } 326 void doit() { 327 // Resize the old thread counters array 328 jlong* new_counters = resize_counters_array(JavaThread::_jvmci_old_thread_counters, JVMCICounterSize, _new_size); 329 if (new_counters == nullptr) { 330 _failed = true; 331 return; 332 } else { 333 JavaThread::_jvmci_old_thread_counters = new_counters; 334 } 335 336 // Now resize each threads array 337 for (JavaThread* tp : ThreadsListHandle()) { 338 if (!tp->resize_counters(JVMCICounterSize, _new_size)) { 339 _failed = true; 340 break; 341 } 342 } 343 if (!_failed) { 344 JVMCICounterSize = _new_size; 345 } 346 } 347 348 bool failed() { return _failed; } 349 }; 350 351 bool JavaThread::resize_all_jvmci_counters(int new_size) { 352 VM_JVMCIResizeCounters op(new_size); 353 VMThread::execute(&op); 354 return !op.failed(); 355 } 356 357 #endif // INCLUDE_JVMCI 358 359 #ifdef ASSERT 360 // Checks safepoint allowed and clears unhandled oops at potential safepoints. 361 void JavaThread::check_possible_safepoint() { 362 if (_no_safepoint_count > 0) { 363 print_owned_locks(); 364 assert(false, "Possible safepoint reached by thread that does not allow it"); 365 } 366 #ifdef CHECK_UNHANDLED_OOPS 367 // Clear unhandled oops in JavaThreads so we get a crash right away. 368 clear_unhandled_oops(); 369 #endif // CHECK_UNHANDLED_OOPS 370 371 // Macos/aarch64 should be in the right state for safepoint (e.g. 372 // deoptimization needs WXWrite). Crashes caused by the wrong state rarely 373 // happens in practice, making such issues hard to find and reproduce. 374 #if defined(__APPLE__) && defined(AARCH64) 375 if (AssertWXAtThreadSync) { 376 assert_wx_state(WXWrite); 377 } 378 #endif 379 } 380 381 void JavaThread::check_for_valid_safepoint_state() { 382 // Don't complain if running a debugging command. 383 if (DebuggingContext::is_enabled()) return; 384 385 // Check NoSafepointVerifier, which is implied by locks taken that can be 386 // shared with the VM thread. This makes sure that no locks with allow_vm_block 387 // are held. 388 check_possible_safepoint(); 389 390 if (thread_state() != _thread_in_vm) { 391 fatal("LEAF method calling lock?"); 392 } 393 394 if (GCALotAtAllSafepoints) { 395 // We could enter a safepoint here and thus have a gc 396 InterfaceSupport::check_gc_alot(); 397 } 398 } 399 #endif // ASSERT 400 401 // A JavaThread is a normal Java thread 402 403 JavaThread::JavaThread() : 404 // Initialize fields 405 406 _on_thread_list(false), 407 DEBUG_ONLY(_java_call_counter(0) COMMA) 408 _entry_point(nullptr), 409 _deopt_mark(nullptr), 410 _deopt_nmethod(nullptr), 411 _vframe_array_head(nullptr), 412 _vframe_array_last(nullptr), 413 _jvmti_deferred_updates(nullptr), 414 _callee_target(nullptr), 415 _vm_result(nullptr), 416 _vm_result_2(nullptr), 417 418 _current_pending_monitor(nullptr), 419 _current_pending_monitor_is_from_java(true), 420 _current_waiting_monitor(nullptr), 421 _active_handles(nullptr), 422 _free_handle_block(nullptr), 423 _Stalled(0), 424 425 _monitor_chunks(nullptr), 426 427 _suspend_flags(0), 428 429 _thread_state(_thread_new), 430 _saved_exception_pc(nullptr), 431 #ifdef ASSERT 432 _no_safepoint_count(0), 433 _visited_for_critical_count(false), 434 #endif 435 436 _terminated(_not_terminated), 437 _in_deopt_handler(0), 438 _doing_unsafe_access(false), 439 _do_not_unlock_if_synchronized(false), 440 #if INCLUDE_JVMTI 441 _carrier_thread_suspended(false), 442 _is_in_VTMS_transition(false), 443 _is_in_tmp_VTMS_transition(false), 444 #ifdef ASSERT 445 _is_VTMS_transition_disabler(false), 446 #endif 447 #endif 448 _jni_attach_state(_not_attaching_via_jni), 449 #if INCLUDE_JVMCI 450 _pending_deoptimization(-1), 451 _pending_monitorenter(false), 452 _pending_transfer_to_interpreter(false), 453 _in_retryable_allocation(false), 454 _pending_failed_speculation(0), 455 _jvmci{nullptr}, 456 _libjvmci_runtime(nullptr), 457 _jvmci_counters(nullptr), 458 _jvmci_reserved0(0), 459 _jvmci_reserved1(0), 460 _jvmci_reserved_oop0(nullptr), 461 #endif // INCLUDE_JVMCI 462 463 _exception_oop(oop()), 464 _exception_pc(0), 465 _exception_handler_pc(0), 466 _is_method_handle_return(0), 467 468 _jni_active_critical(0), 469 _pending_jni_exception_check_fn(nullptr), 470 _depth_first_number(0), 471 472 // JVMTI PopFrame support 473 _popframe_condition(popframe_inactive), 474 _frames_to_pop_failed_realloc(0), 475 476 _cont_entry(nullptr), 477 _cont_fastpath(0), 478 _cont_fastpath_thread_state(1), 479 _held_monitor_count(0), 480 _jni_monitor_count(0), 481 482 _handshake(this), 483 484 _popframe_preserved_args(nullptr), 485 _popframe_preserved_args_size(0), 486 487 _jvmti_thread_state(nullptr), 488 _interp_only_mode(0), 489 _should_post_on_exceptions_flag(JNI_FALSE), 490 _thread_stat(new ThreadStatistics()), 491 492 _parker(), 493 494 _class_to_be_initialized(nullptr), 495 496 _SleepEvent(ParkEvent::Allocate(this)), 497 498 _lock_stack(this) { 499 set_jni_functions(jni_functions()); 500 501 #if INCLUDE_JVMCI 502 assert(_jvmci._implicit_exception_pc == nullptr, "must be"); 503 if (JVMCICounterSize > 0) { 504 resize_counters(0, (int) JVMCICounterSize); 505 } 506 #endif // INCLUDE_JVMCI 507 508 // Setup safepoint state info for this thread 509 ThreadSafepointState::create(this); 510 511 SafepointMechanism::initialize_header(this); 512 513 set_requires_cross_modify_fence(false); 514 515 pd_initialize(); 516 assert(deferred_card_mark().is_empty(), "Default MemRegion ctor"); 517 } 518 519 JavaThread::JavaThread(bool is_attaching_via_jni) : JavaThread() { 520 if (is_attaching_via_jni) { 521 _jni_attach_state = _attaching_via_jni; 522 } 523 } 524 525 526 // interrupt support 527 528 void JavaThread::interrupt() { 529 // All callers should have 'this' thread protected by a 530 // ThreadsListHandle so that it cannot terminate and deallocate 531 // itself. 532 debug_only(check_for_dangling_thread_pointer(this);) 533 534 // For Windows _interrupt_event 535 WINDOWS_ONLY(osthread()->set_interrupted(true);) 536 537 // For Thread.sleep 538 _SleepEvent->unpark(); 539 540 // For JSR166 LockSupport.park 541 parker()->unpark(); 542 543 // For ObjectMonitor and JvmtiRawMonitor 544 _ParkEvent->unpark(); 545 } 546 547 548 bool JavaThread::is_interrupted(bool clear_interrupted) { 549 debug_only(check_for_dangling_thread_pointer(this);) 550 551 if (_threadObj.peek() == nullptr) { 552 // If there is no j.l.Thread then it is impossible to have 553 // been interrupted. We can find null during VM initialization 554 // or when a JNI thread is still in the process of attaching. 555 // In such cases this must be the current thread. 556 assert(this == Thread::current(), "invariant"); 557 return false; 558 } 559 560 bool interrupted = java_lang_Thread::interrupted(threadObj()); 561 562 // NOTE that since there is no "lock" around the interrupt and 563 // is_interrupted operations, there is the possibility that the 564 // interrupted flag will be "false" but that the 565 // low-level events will be in the signaled state. This is 566 // intentional. The effect of this is that Object.wait() and 567 // LockSupport.park() will appear to have a spurious wakeup, which 568 // is allowed and not harmful, and the possibility is so rare that 569 // it is not worth the added complexity to add yet another lock. 570 // For the sleep event an explicit reset is performed on entry 571 // to JavaThread::sleep, so there is no early return. It has also been 572 // recommended not to put the interrupted flag into the "event" 573 // structure because it hides the issue. 574 // Also, because there is no lock, we must only clear the interrupt 575 // state if we are going to report that we were interrupted; otherwise 576 // an interrupt that happens just after we read the field would be lost. 577 if (interrupted && clear_interrupted) { 578 assert(this == Thread::current(), "only the current thread can clear"); 579 java_lang_Thread::set_interrupted(threadObj(), false); 580 WINDOWS_ONLY(osthread()->set_interrupted(false);) 581 } 582 583 return interrupted; 584 } 585 586 void JavaThread::block_if_vm_exited() { 587 if (_terminated == _vm_exited) { 588 // _vm_exited is set at safepoint, and Threads_lock is never released 589 // so we will block here forever. 590 // Here we can be doing a jump from a safe state to an unsafe state without 591 // proper transition, but it happens after the final safepoint has begun so 592 // this jump won't cause any safepoint problems. 593 set_thread_state(_thread_in_vm); 594 Threads_lock->lock(); 595 ShouldNotReachHere(); 596 } 597 } 598 599 JavaThread::JavaThread(ThreadFunction entry_point, size_t stack_sz) : JavaThread() { 600 _jni_attach_state = _not_attaching_via_jni; 601 set_entry_point(entry_point); 602 // Create the native thread itself. 603 // %note runtime_23 604 os::ThreadType thr_type = os::java_thread; 605 thr_type = entry_point == &CompilerThread::thread_entry ? os::compiler_thread : 606 os::java_thread; 607 os::create_thread(this, thr_type, stack_sz); 608 // The _osthread may be null here because we ran out of memory (too many threads active). 609 // We need to throw and OutOfMemoryError - however we cannot do this here because the caller 610 // may hold a lock and all locks must be unlocked before throwing the exception (throwing 611 // the exception consists of creating the exception object & initializing it, initialization 612 // will leave the VM via a JavaCall and then all locks must be unlocked). 613 // 614 // The thread is still suspended when we reach here. Thread must be explicit started 615 // by creator! Furthermore, the thread must also explicitly be added to the Threads list 616 // by calling Threads:add. The reason why this is not done here, is because the thread 617 // object must be fully initialized (take a look at JVM_Start) 618 } 619 620 JavaThread::~JavaThread() { 621 622 // Enqueue OopHandles for release by the service thread. 623 add_oop_handles_for_release(); 624 625 // Return the sleep event to the free list 626 ParkEvent::Release(_SleepEvent); 627 _SleepEvent = nullptr; 628 629 // Free any remaining previous UnrollBlock 630 vframeArray* old_array = vframe_array_last(); 631 632 if (old_array != nullptr) { 633 Deoptimization::UnrollBlock* old_info = old_array->unroll_block(); 634 old_array->set_unroll_block(nullptr); 635 delete old_info; 636 delete old_array; 637 } 638 639 JvmtiDeferredUpdates* updates = deferred_updates(); 640 if (updates != nullptr) { 641 // This can only happen if thread is destroyed before deoptimization occurs. 642 assert(updates->count() > 0, "Updates holder not deleted"); 643 // free deferred updates. 644 delete updates; 645 set_deferred_updates(nullptr); 646 } 647 648 // All Java related clean up happens in exit 649 ThreadSafepointState::destroy(this); 650 if (_thread_stat != nullptr) delete _thread_stat; 651 652 #if INCLUDE_JVMCI 653 if (JVMCICounterSize > 0) { 654 FREE_C_HEAP_ARRAY(jlong, _jvmci_counters); 655 } 656 #endif // INCLUDE_JVMCI 657 } 658 659 660 // First JavaThread specific code executed by a new Java thread. 661 void JavaThread::pre_run() { 662 // empty - see comments in run() 663 } 664 665 // The main routine called by a new Java thread. This isn't overridden 666 // by subclasses, instead different subclasses define a different "entry_point" 667 // which defines the actual logic for that kind of thread. 668 void JavaThread::run() { 669 // initialize thread-local alloc buffer related fields 670 initialize_tlab(); 671 672 _stack_overflow_state.create_stack_guard_pages(); 673 674 cache_global_variables(); 675 676 // Thread is now sufficiently initialized to be handled by the safepoint code as being 677 // in the VM. Change thread state from _thread_new to _thread_in_vm 678 assert(this->thread_state() == _thread_new, "wrong thread state"); 679 set_thread_state(_thread_in_vm); 680 681 // Before a thread is on the threads list it is always safe, so after leaving the 682 // _thread_new we should emit a instruction barrier. The distance to modified code 683 // from here is probably far enough, but this is consistent and safe. 684 OrderAccess::cross_modify_fence(); 685 686 assert(JavaThread::current() == this, "sanity check"); 687 assert(!Thread::current()->owns_locks(), "sanity check"); 688 689 DTRACE_THREAD_PROBE(start, this); 690 691 // This operation might block. We call that after all safepoint checks for a new thread has 692 // been completed. 693 set_active_handles(JNIHandleBlock::allocate_block()); 694 695 if (JvmtiExport::should_post_thread_life()) { 696 JvmtiExport::post_thread_start(this); 697 698 } 699 700 if (AlwaysPreTouchStacks) { 701 pretouch_stack(); 702 } 703 704 // We call another function to do the rest so we are sure that the stack addresses used 705 // from there will be lower than the stack base just computed. 706 thread_main_inner(); 707 } 708 709 void JavaThread::thread_main_inner() { 710 assert(JavaThread::current() == this, "sanity check"); 711 assert(_threadObj.peek() != nullptr, "just checking"); 712 713 // Execute thread entry point unless this thread has a pending exception. 714 // Note: Due to JVMTI StopThread we can have pending exceptions already! 715 if (!this->has_pending_exception()) { 716 { 717 ResourceMark rm(this); 718 this->set_native_thread_name(this->name()); 719 } 720 HandleMark hm(this); 721 this->entry_point()(this, this); 722 } 723 724 DTRACE_THREAD_PROBE(stop, this); 725 726 // Cleanup is handled in post_run() 727 } 728 729 // Shared teardown for all JavaThreads 730 void JavaThread::post_run() { 731 this->exit(false); 732 this->unregister_thread_stack_with_NMT(); 733 // Defer deletion to here to ensure 'this' is still referenceable in call_run 734 // for any shared tear-down. 735 this->smr_delete(); 736 } 737 738 static void ensure_join(JavaThread* thread) { 739 // We do not need to grab the Threads_lock, since we are operating on ourself. 740 Handle threadObj(thread, thread->threadObj()); 741 assert(threadObj.not_null(), "java thread object must exist"); 742 ObjectLocker lock(threadObj, thread); 743 // Thread is exiting. So set thread_status field in java.lang.Thread class to TERMINATED. 744 java_lang_Thread::set_thread_status(threadObj(), JavaThreadStatus::TERMINATED); 745 // Clear the native thread instance - this makes isAlive return false and allows the join() 746 // to complete once we've done the notify_all below. Needs a release() to obey Java Memory Model 747 // requirements. 748 java_lang_Thread::release_set_thread(threadObj(), nullptr); 749 lock.notify_all(thread); 750 // Ignore pending exception, since we are exiting anyway 751 thread->clear_pending_exception(); 752 } 753 754 static bool is_daemon(oop threadObj) { 755 return (threadObj != nullptr && java_lang_Thread::is_daemon(threadObj)); 756 } 757 758 // For any new cleanup additions, please check to see if they need to be applied to 759 // cleanup_failed_attach_current_thread as well. 760 void JavaThread::exit(bool destroy_vm, ExitType exit_type) { 761 assert(this == JavaThread::current(), "thread consistency check"); 762 assert(!is_exiting(), "should not be exiting or terminated already"); 763 764 elapsedTimer _timer_exit_phase1; 765 elapsedTimer _timer_exit_phase2; 766 elapsedTimer _timer_exit_phase3; 767 elapsedTimer _timer_exit_phase4; 768 769 if (log_is_enabled(Debug, os, thread, timer)) { 770 _timer_exit_phase1.start(); 771 } 772 773 HandleMark hm(this); 774 Handle uncaught_exception(this, this->pending_exception()); 775 this->clear_pending_exception(); 776 Handle threadObj(this, this->threadObj()); 777 assert(threadObj.not_null(), "Java thread object should be created"); 778 779 if (!destroy_vm) { 780 if (uncaught_exception.not_null()) { 781 EXCEPTION_MARK; 782 // Call method Thread.dispatchUncaughtException(). 783 Klass* thread_klass = vmClasses::Thread_klass(); 784 JavaValue result(T_VOID); 785 JavaCalls::call_virtual(&result, 786 threadObj, thread_klass, 787 vmSymbols::dispatchUncaughtException_name(), 788 vmSymbols::throwable_void_signature(), 789 uncaught_exception, 790 THREAD); 791 if (HAS_PENDING_EXCEPTION) { 792 ResourceMark rm(this); 793 jio_fprintf(defaultStream::error_stream(), 794 "\nException: %s thrown from the UncaughtExceptionHandler" 795 " in thread \"%s\"\n", 796 pending_exception()->klass()->external_name(), 797 name()); 798 CLEAR_PENDING_EXCEPTION; 799 } 800 } 801 802 if (!is_Compiler_thread()) { 803 // We have finished executing user-defined Java code and now have to do the 804 // implementation specific clean-up by calling Thread.exit(). We prevent any 805 // asynchronous exceptions from being delivered while in Thread.exit() 806 // to ensure the clean-up is not corrupted. 807 NoAsyncExceptionDeliveryMark _no_async(this); 808 809 EXCEPTION_MARK; 810 JavaValue result(T_VOID); 811 Klass* thread_klass = vmClasses::Thread_klass(); 812 JavaCalls::call_virtual(&result, 813 threadObj, thread_klass, 814 vmSymbols::exit_method_name(), 815 vmSymbols::void_method_signature(), 816 THREAD); 817 CLEAR_PENDING_EXCEPTION; 818 } 819 820 // notify JVMTI 821 if (JvmtiExport::should_post_thread_life()) { 822 JvmtiExport::post_thread_end(this); 823 } 824 } else { 825 // before_exit() has already posted JVMTI THREAD_END events 826 } 827 828 // Cleanup any pending async exception now since we cannot access oops after 829 // BarrierSet::barrier_set()->on_thread_detach() has been executed. 830 if (has_async_exception_condition()) { 831 handshake_state()->clean_async_exception_operation(); 832 } 833 834 // The careful dance between thread suspension and exit is handled here. 835 // Since we are in thread_in_vm state and suspension is done with handshakes, 836 // we can just put in the exiting state and it will be correctly handled. 837 // Also, no more async exceptions will be added to the queue after this point. 838 set_terminated(_thread_exiting); 839 ThreadService::current_thread_exiting(this, is_daemon(threadObj())); 840 841 if (log_is_enabled(Debug, os, thread, timer)) { 842 _timer_exit_phase1.stop(); 843 _timer_exit_phase2.start(); 844 } 845 846 // Capture daemon status before the thread is marked as terminated. 847 bool daemon = is_daemon(threadObj()); 848 849 // Notify waiters on thread object. This has to be done after exit() is called 850 // on the thread (if the thread is the last thread in a daemon ThreadGroup the 851 // group should have the destroyed bit set before waiters are notified). 852 ensure_join(this); 853 assert(!this->has_pending_exception(), "ensure_join should have cleared"); 854 855 if (log_is_enabled(Debug, os, thread, timer)) { 856 _timer_exit_phase2.stop(); 857 _timer_exit_phase3.start(); 858 } 859 // 6282335 JNI DetachCurrentThread spec states that all Java monitors 860 // held by this thread must be released. The spec does not distinguish 861 // between JNI-acquired and regular Java monitors. We can only see 862 // regular Java monitors here if monitor enter-exit matching is broken. 863 // 864 // ensure_join() ignores IllegalThreadStateExceptions, and so does 865 // ObjectSynchronizer::release_monitors_owned_by_thread(). 866 if (exit_type == jni_detach) { 867 // Sanity check even though JNI DetachCurrentThread() would have 868 // returned JNI_ERR if there was a Java frame. JavaThread exit 869 // should be done executing Java code by the time we get here. 870 assert(!this->has_last_Java_frame(), 871 "should not have a Java frame when detaching or exiting"); 872 ObjectSynchronizer::release_monitors_owned_by_thread(this); 873 assert(!this->has_pending_exception(), "release_monitors should have cleared"); 874 } 875 876 // Since above code may not release JNI monitors and if someone forgot to do an 877 // JNI monitorexit, held count should be equal jni count. 878 // Consider scan all object monitor for this owner if JNI count > 0 (at least on detach). 879 assert(this->held_monitor_count() == this->jni_monitor_count(), 880 "held monitor count should be equal to jni: " INT64_FORMAT " != " INT64_FORMAT, 881 (int64_t)this->held_monitor_count(), (int64_t)this->jni_monitor_count()); 882 if (CheckJNICalls && this->jni_monitor_count() > 0) { 883 // We would like a fatal here, but due to we never checked this before there 884 // is a lot of tests which breaks, even with an error log. 885 log_debug(jni)("JavaThread %s (tid: " UINTX_FORMAT ") with Objects still locked by JNI MonitorEnter.", 886 exit_type == JavaThread::normal_exit ? "exiting" : "detaching", os::current_thread_id()); 887 } 888 889 // These things needs to be done while we are still a Java Thread. Make sure that thread 890 // is in a consistent state, in case GC happens 891 JFR_ONLY(Jfr::on_thread_exit(this);) 892 893 if (active_handles() != nullptr) { 894 JNIHandleBlock* block = active_handles(); 895 set_active_handles(nullptr); 896 JNIHandleBlock::release_block(block); 897 } 898 899 if (free_handle_block() != nullptr) { 900 JNIHandleBlock* block = free_handle_block(); 901 set_free_handle_block(nullptr); 902 JNIHandleBlock::release_block(block); 903 } 904 905 // These have to be removed while this is still a valid thread. 906 _stack_overflow_state.remove_stack_guard_pages(); 907 908 if (UseTLAB) { 909 tlab().retire(); 910 } 911 912 if (JvmtiEnv::environments_might_exist()) { 913 JvmtiExport::cleanup_thread(this); 914 } 915 916 // We need to cache the thread name for logging purposes below as once 917 // we have called on_thread_detach this thread must not access any oops. 918 char* thread_name = nullptr; 919 if (log_is_enabled(Debug, os, thread, timer)) { 920 ResourceMark rm(this); 921 thread_name = os::strdup(name()); 922 } 923 924 log_info(os, thread)("JavaThread %s (tid: " UINTX_FORMAT ").", 925 exit_type == JavaThread::normal_exit ? "exiting" : "detaching", 926 os::current_thread_id()); 927 928 if (log_is_enabled(Debug, os, thread, timer)) { 929 _timer_exit_phase3.stop(); 930 _timer_exit_phase4.start(); 931 } 932 933 #if INCLUDE_JVMCI 934 if (JVMCICounterSize > 0) { 935 if (jvmci_counters_include(this)) { 936 for (int i = 0; i < JVMCICounterSize; i++) { 937 _jvmci_old_thread_counters[i] += _jvmci_counters[i]; 938 } 939 } 940 } 941 #endif // INCLUDE_JVMCI 942 943 // Remove from list of active threads list, and notify VM thread if we are the last non-daemon thread. 944 // We call BarrierSet::barrier_set()->on_thread_detach() here so no touching of oops after this point. 945 Threads::remove(this, daemon); 946 947 if (log_is_enabled(Debug, os, thread, timer)) { 948 _timer_exit_phase4.stop(); 949 log_debug(os, thread, timer)("name='%s'" 950 ", exit-phase1=" JLONG_FORMAT 951 ", exit-phase2=" JLONG_FORMAT 952 ", exit-phase3=" JLONG_FORMAT 953 ", exit-phase4=" JLONG_FORMAT, 954 thread_name, 955 _timer_exit_phase1.milliseconds(), 956 _timer_exit_phase2.milliseconds(), 957 _timer_exit_phase3.milliseconds(), 958 _timer_exit_phase4.milliseconds()); 959 os::free(thread_name); 960 } 961 } 962 963 void JavaThread::cleanup_failed_attach_current_thread(bool is_daemon) { 964 if (active_handles() != nullptr) { 965 JNIHandleBlock* block = active_handles(); 966 set_active_handles(nullptr); 967 JNIHandleBlock::release_block(block); 968 } 969 970 if (free_handle_block() != nullptr) { 971 JNIHandleBlock* block = free_handle_block(); 972 set_free_handle_block(nullptr); 973 JNIHandleBlock::release_block(block); 974 } 975 976 // These have to be removed while this is still a valid thread. 977 _stack_overflow_state.remove_stack_guard_pages(); 978 979 if (UseTLAB) { 980 tlab().retire(); 981 } 982 983 Threads::remove(this, is_daemon); 984 this->smr_delete(); 985 } 986 987 JavaThread* JavaThread::active() { 988 Thread* thread = Thread::current(); 989 if (thread->is_Java_thread()) { 990 return JavaThread::cast(thread); 991 } else { 992 assert(thread->is_VM_thread(), "this must be a vm thread"); 993 VM_Operation* op = ((VMThread*) thread)->vm_operation(); 994 JavaThread *ret = op == nullptr ? nullptr : JavaThread::cast(op->calling_thread()); 995 return ret; 996 } 997 } 998 999 bool JavaThread::is_lock_owned(address adr) const { 1000 assert(LockingMode != LM_LIGHTWEIGHT, "should not be called with new lightweight locking"); 1001 if (Thread::is_lock_owned(adr)) return true; 1002 1003 for (MonitorChunk* chunk = monitor_chunks(); chunk != nullptr; chunk = chunk->next()) { 1004 if (chunk->contains(adr)) return true; 1005 } 1006 1007 return false; 1008 } 1009 1010 oop JavaThread::exception_oop() const { 1011 return Atomic::load(&_exception_oop); 1012 } 1013 1014 void JavaThread::set_exception_oop(oop o) { 1015 Atomic::store(&_exception_oop, o); 1016 } 1017 1018 void JavaThread::add_monitor_chunk(MonitorChunk* chunk) { 1019 chunk->set_next(monitor_chunks()); 1020 set_monitor_chunks(chunk); 1021 } 1022 1023 void JavaThread::remove_monitor_chunk(MonitorChunk* chunk) { 1024 guarantee(monitor_chunks() != nullptr, "must be non empty"); 1025 if (monitor_chunks() == chunk) { 1026 set_monitor_chunks(chunk->next()); 1027 } else { 1028 MonitorChunk* prev = monitor_chunks(); 1029 while (prev->next() != chunk) prev = prev->next(); 1030 prev->set_next(chunk->next()); 1031 } 1032 } 1033 1034 void JavaThread::handle_special_runtime_exit_condition() { 1035 if (is_obj_deopt_suspend()) { 1036 frame_anchor()->make_walkable(); 1037 wait_for_object_deoptimization(); 1038 } 1039 JFR_ONLY(SUSPEND_THREAD_CONDITIONAL(this);) 1040 } 1041 1042 1043 // Asynchronous exceptions support 1044 // 1045 void JavaThread::handle_async_exception(oop java_throwable) { 1046 assert(java_throwable != nullptr, "should have an _async_exception to throw"); 1047 assert(!is_at_poll_safepoint(), "should have never called this method"); 1048 1049 if (has_last_Java_frame()) { 1050 frame f = last_frame(); 1051 if (f.is_runtime_frame()) { 1052 // If the topmost frame is a runtime stub, then we are calling into 1053 // OptoRuntime from compiled code. Some runtime stubs (new, monitor_exit..) 1054 // must deoptimize the caller before continuing, as the compiled exception 1055 // handler table may not be valid. 1056 RegisterMap reg_map(this, 1057 RegisterMap::UpdateMap::skip, 1058 RegisterMap::ProcessFrames::include, 1059 RegisterMap::WalkContinuation::skip); 1060 frame compiled_frame = f.sender(®_map); 1061 if (!StressCompiledExceptionHandlers && compiled_frame.can_be_deoptimized()) { 1062 Deoptimization::deoptimize(this, compiled_frame); 1063 } 1064 } 1065 } 1066 1067 // We cannot call Exceptions::_throw(...) here because we cannot block 1068 set_pending_exception(java_throwable, __FILE__, __LINE__); 1069 1070 clear_scopedValueBindings(); 1071 1072 LogTarget(Info, exceptions) lt; 1073 if (lt.is_enabled()) { 1074 ResourceMark rm; 1075 LogStream ls(lt); 1076 ls.print("Async. exception installed at runtime exit (" INTPTR_FORMAT ")", p2i(this)); 1077 if (has_last_Java_frame()) { 1078 frame f = last_frame(); 1079 ls.print(" (pc: " INTPTR_FORMAT " sp: " INTPTR_FORMAT " )", p2i(f.pc()), p2i(f.sp())); 1080 } 1081 ls.print_cr(" of type: %s", java_throwable->klass()->external_name()); 1082 } 1083 } 1084 1085 void JavaThread::install_async_exception(AsyncExceptionHandshake* aeh) { 1086 // Do not throw asynchronous exceptions against the compiler thread 1087 // or if the thread is already exiting. 1088 if (!can_call_java() || is_exiting()) { 1089 delete aeh; 1090 return; 1091 } 1092 1093 oop exception = aeh->exception(); 1094 Handshake::execute(aeh, this); // Install asynchronous handshake 1095 1096 ResourceMark rm; 1097 if (log_is_enabled(Info, exceptions)) { 1098 log_info(exceptions)("Pending Async. exception installed of type: %s", 1099 InstanceKlass::cast(exception->klass())->external_name()); 1100 } 1101 // for AbortVMOnException flag 1102 Exceptions::debug_check_abort(exception->klass()->external_name()); 1103 1104 oop vt_oop = vthread(); 1105 if (vt_oop == nullptr || !vt_oop->is_a(vmClasses::BaseVirtualThread_klass())) { 1106 // Interrupt thread so it will wake up from a potential wait()/sleep()/park() 1107 java_lang_Thread::set_interrupted(threadObj(), true); 1108 this->interrupt(); 1109 } 1110 } 1111 1112 class InstallAsyncExceptionHandshake : public HandshakeClosure { 1113 AsyncExceptionHandshake* _aeh; 1114 public: 1115 InstallAsyncExceptionHandshake(AsyncExceptionHandshake* aeh) : 1116 HandshakeClosure("InstallAsyncException"), _aeh(aeh) {} 1117 ~InstallAsyncExceptionHandshake() { 1118 // If InstallAsyncExceptionHandshake was never executed we need to clean up _aeh. 1119 delete _aeh; 1120 } 1121 void do_thread(Thread* thr) { 1122 JavaThread* target = JavaThread::cast(thr); 1123 target->install_async_exception(_aeh); 1124 _aeh = nullptr; 1125 } 1126 }; 1127 1128 void JavaThread::send_async_exception(JavaThread* target, oop java_throwable) { 1129 OopHandle e(Universe::vm_global(), java_throwable); 1130 InstallAsyncExceptionHandshake iaeh(new AsyncExceptionHandshake(e)); 1131 Handshake::execute(&iaeh, target); 1132 } 1133 1134 #if INCLUDE_JVMTI 1135 void JavaThread::set_is_in_VTMS_transition(bool val) { 1136 _is_in_VTMS_transition = val; 1137 } 1138 1139 #ifdef ASSERT 1140 void JavaThread::set_is_VTMS_transition_disabler(bool val) { 1141 _is_VTMS_transition_disabler = val; 1142 } 1143 #endif 1144 #endif 1145 1146 // External suspension mechanism. 1147 // 1148 // Guarantees on return (for a valid target thread): 1149 // - Target thread will not execute any new bytecode. 1150 // - Target thread will not enter any new monitors. 1151 // 1152 bool JavaThread::java_suspend() { 1153 #if INCLUDE_JVMTI 1154 // Suspending a JavaThread in VTMS transition or disabling VTMS transitions can cause deadlocks. 1155 assert(!is_in_VTMS_transition(), "no suspend allowed in VTMS transition"); 1156 assert(!is_VTMS_transition_disabler(), "no suspend allowed for VTMS transition disablers"); 1157 #endif 1158 1159 guarantee(Thread::is_JavaThread_protected(/* target */ this), 1160 "target JavaThread is not protected in calling context."); 1161 return this->handshake_state()->suspend(); 1162 } 1163 1164 bool JavaThread::java_resume() { 1165 guarantee(Thread::is_JavaThread_protected_by_TLH(/* target */ this), 1166 "missing ThreadsListHandle in calling context."); 1167 return this->handshake_state()->resume(); 1168 } 1169 1170 // Wait for another thread to perform object reallocation and relocking on behalf of 1171 // this thread. The current thread is required to change to _thread_blocked in order 1172 // to be seen to be safepoint/handshake safe whilst suspended and only after becoming 1173 // handshake safe, the other thread can complete the handshake used to synchronize 1174 // with this thread and then perform the reallocation and relocking. 1175 // See EscapeBarrier::sync_and_suspend_*() 1176 1177 void JavaThread::wait_for_object_deoptimization() { 1178 assert(!has_last_Java_frame() || frame_anchor()->walkable(), "should have walkable stack"); 1179 assert(this == Thread::current(), "invariant"); 1180 1181 bool spin_wait = os::is_MP(); 1182 do { 1183 ThreadBlockInVM tbivm(this, true /* allow_suspend */); 1184 // Wait for object deoptimization if requested. 1185 if (spin_wait) { 1186 // A single deoptimization is typically very short. Microbenchmarks 1187 // showed 5% better performance when spinning. 1188 const uint spin_limit = 10 * SpinYield::default_spin_limit; 1189 SpinYield spin(spin_limit); 1190 for (uint i = 0; is_obj_deopt_suspend() && i < spin_limit; i++) { 1191 spin.wait(); 1192 } 1193 // Spin just once 1194 spin_wait = false; 1195 } else { 1196 MonitorLocker ml(this, EscapeBarrier_lock, Monitor::_no_safepoint_check_flag); 1197 if (is_obj_deopt_suspend()) { 1198 ml.wait(); 1199 } 1200 } 1201 // A handshake for obj. deoptimization suspend could have been processed so 1202 // we must check after processing. 1203 } while (is_obj_deopt_suspend()); 1204 } 1205 1206 #ifdef ASSERT 1207 // Verify the JavaThread has not yet been published in the Threads::list, and 1208 // hence doesn't need protection from concurrent access at this stage. 1209 void JavaThread::verify_not_published() { 1210 // Cannot create a ThreadsListHandle here and check !tlh.includes(this) 1211 // since an unpublished JavaThread doesn't participate in the 1212 // Thread-SMR protocol for keeping a ThreadsList alive. 1213 assert(!on_thread_list(), "JavaThread shouldn't have been published yet!"); 1214 } 1215 #endif 1216 1217 // Slow path when the native==>Java barriers detect a safepoint/handshake is 1218 // pending, when _suspend_flags is non-zero or when we need to process a stack 1219 // watermark. Also check for pending async exceptions (except unsafe access error). 1220 // Note only the native==>Java barriers can call this function when thread state 1221 // is _thread_in_native_trans. 1222 void JavaThread::check_special_condition_for_native_trans(JavaThread *thread) { 1223 assert(thread->thread_state() == _thread_in_native_trans, "wrong state"); 1224 assert(!thread->has_last_Java_frame() || thread->frame_anchor()->walkable(), "Unwalkable stack in native->Java transition"); 1225 1226 thread->set_thread_state(_thread_in_vm); 1227 1228 // Enable WXWrite: called directly from interpreter native wrapper. 1229 MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXWrite, thread)); 1230 1231 SafepointMechanism::process_if_requested_with_exit_check(thread, true /* check asyncs */); 1232 1233 // After returning from native, it could be that the stack frames are not 1234 // yet safe to use. We catch such situations in the subsequent stack watermark 1235 // barrier, which will trap unsafe stack frames. 1236 StackWatermarkSet::before_unwind(thread); 1237 } 1238 1239 #ifndef PRODUCT 1240 // Deoptimization 1241 // Function for testing deoptimization 1242 void JavaThread::deoptimize() { 1243 StackFrameStream fst(this, false /* update */, true /* process_frames */); 1244 bool deopt = false; // Dump stack only if a deopt actually happens. 1245 bool only_at = strlen(DeoptimizeOnlyAt) > 0; 1246 // Iterate over all frames in the thread and deoptimize 1247 for (; !fst.is_done(); fst.next()) { 1248 if (fst.current()->can_be_deoptimized()) { 1249 1250 if (only_at) { 1251 // Deoptimize only at particular bcis. DeoptimizeOnlyAt 1252 // consists of comma or carriage return separated numbers so 1253 // search for the current bci in that string. 1254 address pc = fst.current()->pc(); 1255 nmethod* nm = (nmethod*) fst.current()->cb(); 1256 ScopeDesc* sd = nm->scope_desc_at(pc); 1257 char buffer[8]; 1258 jio_snprintf(buffer, sizeof(buffer), "%d", sd->bci()); 1259 size_t len = strlen(buffer); 1260 const char * found = strstr(DeoptimizeOnlyAt, buffer); 1261 while (found != nullptr) { 1262 if ((found[len] == ',' || found[len] == '\n' || found[len] == '\0') && 1263 (found == DeoptimizeOnlyAt || found[-1] == ',' || found[-1] == '\n')) { 1264 // Check that the bci found is bracketed by terminators. 1265 break; 1266 } 1267 found = strstr(found + 1, buffer); 1268 } 1269 if (!found) { 1270 continue; 1271 } 1272 } 1273 1274 if (DebugDeoptimization && !deopt) { 1275 deopt = true; // One-time only print before deopt 1276 tty->print_cr("[BEFORE Deoptimization]"); 1277 trace_frames(); 1278 trace_stack(); 1279 } 1280 Deoptimization::deoptimize(this, *fst.current()); 1281 } 1282 } 1283 1284 if (DebugDeoptimization && deopt) { 1285 tty->print_cr("[AFTER Deoptimization]"); 1286 trace_frames(); 1287 } 1288 } 1289 1290 1291 // Make zombies 1292 void JavaThread::make_zombies() { 1293 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) { 1294 if (fst.current()->can_be_deoptimized()) { 1295 // it is a Java nmethod 1296 nmethod* nm = CodeCache::find_nmethod(fst.current()->pc()); 1297 nm->make_not_entrant(); 1298 } 1299 } 1300 } 1301 #endif // PRODUCT 1302 1303 1304 void JavaThread::deoptimize_marked_methods() { 1305 if (!has_last_Java_frame()) return; 1306 StackFrameStream fst(this, false /* update */, true /* process_frames */); 1307 for (; !fst.is_done(); fst.next()) { 1308 if (fst.current()->should_be_deoptimized()) { 1309 Deoptimization::deoptimize(this, *fst.current()); 1310 } 1311 } 1312 } 1313 1314 #ifdef ASSERT 1315 void JavaThread::verify_frame_info() { 1316 assert((!has_last_Java_frame() && java_call_counter() == 0) || 1317 (has_last_Java_frame() && java_call_counter() > 0), 1318 "unexpected frame info: has_last_frame=%s, java_call_counter=%d", 1319 has_last_Java_frame() ? "true" : "false", java_call_counter()); 1320 } 1321 #endif 1322 1323 // Push on a new block of JNI handles. 1324 void JavaThread::push_jni_handle_block() { 1325 // Allocate a new block for JNI handles. 1326 // Inlined code from jni_PushLocalFrame() 1327 JNIHandleBlock* old_handles = active_handles(); 1328 JNIHandleBlock* new_handles = JNIHandleBlock::allocate_block(this); 1329 assert(old_handles != nullptr && new_handles != nullptr, "should not be null"); 1330 new_handles->set_pop_frame_link(old_handles); // make sure java handles get gc'd. 1331 set_active_handles(new_handles); 1332 } 1333 1334 // Pop off the current block of JNI handles. 1335 void JavaThread::pop_jni_handle_block() { 1336 // Release our JNI handle block 1337 JNIHandleBlock* old_handles = active_handles(); 1338 JNIHandleBlock* new_handles = old_handles->pop_frame_link(); 1339 assert(new_handles != nullptr, "should never set active handles to null"); 1340 set_active_handles(new_handles); 1341 old_handles->set_pop_frame_link(nullptr); 1342 JNIHandleBlock::release_block(old_handles, this); 1343 } 1344 1345 void JavaThread::oops_do_no_frames(OopClosure* f, CodeBlobClosure* cf) { 1346 // Verify that the deferred card marks have been flushed. 1347 assert(deferred_card_mark().is_empty(), "Should be empty during GC"); 1348 1349 // Traverse the GCHandles 1350 Thread::oops_do_no_frames(f, cf); 1351 1352 if (active_handles() != nullptr) { 1353 active_handles()->oops_do(f); 1354 } 1355 1356 DEBUG_ONLY(verify_frame_info();) 1357 1358 if (has_last_Java_frame()) { 1359 // Traverse the monitor chunks 1360 for (MonitorChunk* chunk = monitor_chunks(); chunk != nullptr; chunk = chunk->next()) { 1361 chunk->oops_do(f); 1362 } 1363 } 1364 1365 assert(vframe_array_head() == nullptr, "deopt in progress at a safepoint!"); 1366 // If we have deferred set_locals there might be oops waiting to be 1367 // written 1368 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = JvmtiDeferredUpdates::deferred_locals(this); 1369 if (list != nullptr) { 1370 for (int i = 0; i < list->length(); i++) { 1371 list->at(i)->oops_do(f); 1372 } 1373 } 1374 1375 // Traverse instance variables at the end since the GC may be moving things 1376 // around using this function 1377 f->do_oop((oop*) &_vm_result); 1378 f->do_oop((oop*) &_exception_oop); 1379 #if INCLUDE_JVMCI 1380 f->do_oop((oop*) &_jvmci_reserved_oop0); 1381 #endif 1382 1383 if (jvmti_thread_state() != nullptr) { 1384 jvmti_thread_state()->oops_do(f, cf); 1385 } 1386 1387 // The continuation oops are really on the stack. But there is typically at most 1388 // one of those per thread, so we handle them here in the oops_do_no_frames part 1389 // so that we don't have to sprinkle as many stack watermark checks where these 1390 // oops are used. We just need to make sure the thread has started processing. 1391 ContinuationEntry* entry = _cont_entry; 1392 while (entry != nullptr) { 1393 f->do_oop((oop*)entry->cont_addr()); 1394 f->do_oop((oop*)entry->chunk_addr()); 1395 entry = entry->parent(); 1396 } 1397 1398 if (LockingMode == LM_LIGHTWEIGHT) { 1399 lock_stack().oops_do(f); 1400 } 1401 } 1402 1403 void JavaThread::oops_do_frames(OopClosure* f, CodeBlobClosure* cf) { 1404 if (!has_last_Java_frame()) { 1405 return; 1406 } 1407 // Finish any pending lazy GC activity for the frames 1408 StackWatermarkSet::finish_processing(this, nullptr /* context */, StackWatermarkKind::gc); 1409 // Traverse the execution stack 1410 for (StackFrameStream fst(this, true /* update */, false /* process_frames */); !fst.is_done(); fst.next()) { 1411 fst.current()->oops_do(f, cf, fst.register_map()); 1412 } 1413 } 1414 1415 #ifdef ASSERT 1416 void JavaThread::verify_states_for_handshake() { 1417 // This checks that the thread has a correct frame state during a handshake. 1418 verify_frame_info(); 1419 } 1420 #endif 1421 1422 void JavaThread::nmethods_do(CodeBlobClosure* cf) { 1423 DEBUG_ONLY(verify_frame_info();) 1424 MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXWrite, Thread::current());) 1425 1426 if (has_last_Java_frame()) { 1427 // Traverse the execution stack 1428 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) { 1429 fst.current()->nmethods_do(cf); 1430 } 1431 } 1432 1433 if (jvmti_thread_state() != nullptr) { 1434 jvmti_thread_state()->nmethods_do(cf); 1435 } 1436 } 1437 1438 void JavaThread::metadata_do(MetadataClosure* f) { 1439 if (has_last_Java_frame()) { 1440 // Traverse the execution stack to call f() on the methods in the stack 1441 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) { 1442 fst.current()->metadata_do(f); 1443 } 1444 } else if (is_Compiler_thread()) { 1445 // need to walk ciMetadata in current compile tasks to keep alive. 1446 CompilerThread* ct = (CompilerThread*)this; 1447 if (ct->env() != nullptr) { 1448 ct->env()->metadata_do(f); 1449 } 1450 CompileTask* task = ct->task(); 1451 if (task != nullptr) { 1452 task->metadata_do(f); 1453 } 1454 } 1455 } 1456 1457 // Printing 1458 const char* _get_thread_state_name(JavaThreadState _thread_state) { 1459 switch (_thread_state) { 1460 case _thread_uninitialized: return "_thread_uninitialized"; 1461 case _thread_new: return "_thread_new"; 1462 case _thread_new_trans: return "_thread_new_trans"; 1463 case _thread_in_native: return "_thread_in_native"; 1464 case _thread_in_native_trans: return "_thread_in_native_trans"; 1465 case _thread_in_vm: return "_thread_in_vm"; 1466 case _thread_in_vm_trans: return "_thread_in_vm_trans"; 1467 case _thread_in_Java: return "_thread_in_Java"; 1468 case _thread_in_Java_trans: return "_thread_in_Java_trans"; 1469 case _thread_blocked: return "_thread_blocked"; 1470 case _thread_blocked_trans: return "_thread_blocked_trans"; 1471 default: return "unknown thread state"; 1472 } 1473 } 1474 1475 void JavaThread::print_thread_state_on(outputStream *st) const { 1476 st->print_cr(" JavaThread state: %s", _get_thread_state_name(_thread_state)); 1477 } 1478 1479 // Called by Threads::print() for VM_PrintThreads operation 1480 void JavaThread::print_on(outputStream *st, bool print_extended_info) const { 1481 st->print_raw("\""); 1482 st->print_raw(name()); 1483 st->print_raw("\" "); 1484 oop thread_oop = threadObj(); 1485 if (thread_oop != nullptr) { 1486 st->print("#" INT64_FORMAT " [%ld] ", (int64_t)java_lang_Thread::thread_id(thread_oop), (long) osthread()->thread_id()); 1487 if (java_lang_Thread::is_daemon(thread_oop)) st->print("daemon "); 1488 st->print("prio=%d ", java_lang_Thread::priority(thread_oop)); 1489 } 1490 Thread::print_on(st, print_extended_info); 1491 // print guess for valid stack memory region (assume 4K pages); helps lock debugging 1492 st->print_cr("[" INTPTR_FORMAT "]", (intptr_t)last_Java_sp() & ~right_n_bits(12)); 1493 if (thread_oop != nullptr) { 1494 if (is_vthread_mounted()) { 1495 oop vt = vthread(); 1496 assert(vt != nullptr, ""); 1497 st->print_cr(" Carrying virtual thread #" INT64_FORMAT, (int64_t)java_lang_Thread::thread_id(vt)); 1498 } else { 1499 st->print_cr(" java.lang.Thread.State: %s", java_lang_Thread::thread_status_name(thread_oop)); 1500 } 1501 } 1502 #ifndef PRODUCT 1503 _safepoint_state->print_on(st); 1504 #endif // PRODUCT 1505 if (is_Compiler_thread()) { 1506 CompileTask *task = ((CompilerThread*)this)->task(); 1507 if (task != nullptr) { 1508 st->print(" Compiling: "); 1509 task->print(st, nullptr, true, false); 1510 } else { 1511 st->print(" No compile task"); 1512 } 1513 st->cr(); 1514 } 1515 } 1516 1517 void JavaThread::print() const { print_on(tty); } 1518 1519 void JavaThread::print_name_on_error(outputStream* st, char *buf, int buflen) const { 1520 st->print("%s", get_thread_name_string(buf, buflen)); 1521 } 1522 1523 // Called by fatal error handler. The difference between this and 1524 // JavaThread::print() is that we can't grab lock or allocate memory. 1525 void JavaThread::print_on_error(outputStream* st, char *buf, int buflen) const { 1526 st->print("%s \"%s\"", type_name(), get_thread_name_string(buf, buflen)); 1527 Thread* current = Thread::current_or_null_safe(); 1528 assert(current != nullptr, "cannot be called by a detached thread"); 1529 st->fill_to(60); 1530 if (!current->is_Java_thread() || JavaThread::cast(current)->is_oop_safe()) { 1531 // Only access threadObj() if current thread is not a JavaThread 1532 // or if it is a JavaThread that can safely access oops. 1533 oop thread_obj = threadObj(); 1534 if (thread_obj != nullptr) { 1535 st->print(java_lang_Thread::is_daemon(thread_obj) ? " daemon" : " "); 1536 } 1537 } 1538 st->print(" ["); 1539 st->print("%s", _get_thread_state_name(_thread_state)); 1540 if (osthread()) { 1541 st->print(", id=%d", osthread()->thread_id()); 1542 } 1543 st->print(", stack(" PTR_FORMAT "," PTR_FORMAT ") (" PROPERFMT ")", 1544 p2i(stack_end()), p2i(stack_base()), 1545 PROPERFMTARGS(stack_size())); 1546 st->print("]"); 1547 1548 ThreadsSMRSupport::print_info_on(this, st); 1549 return; 1550 } 1551 1552 1553 // Verification 1554 1555 void JavaThread::frames_do(void f(frame*, const RegisterMap* map)) { 1556 // ignore if there is no stack 1557 if (!has_last_Java_frame()) return; 1558 // traverse the stack frames. Starts from top frame. 1559 for (StackFrameStream fst(this, true /* update_map */, true /* process_frames */, false /* walk_cont */); !fst.is_done(); fst.next()) { 1560 frame* fr = fst.current(); 1561 f(fr, fst.register_map()); 1562 } 1563 } 1564 1565 static void frame_verify(frame* f, const RegisterMap *map) { f->verify(map); } 1566 1567 void JavaThread::verify() { 1568 // Verify oops in the thread. 1569 oops_do(&VerifyOopClosure::verify_oop, nullptr); 1570 1571 // Verify the stack frames. 1572 frames_do(frame_verify); 1573 } 1574 1575 // CR 6300358 (sub-CR 2137150) 1576 // Most callers of this method assume that it can't return null but a 1577 // thread may not have a name whilst it is in the process of attaching to 1578 // the VM - see CR 6412693, and there are places where a JavaThread can be 1579 // seen prior to having its threadObj set (e.g., JNI attaching threads and 1580 // if vm exit occurs during initialization). These cases can all be accounted 1581 // for such that this method never returns null. 1582 const char* JavaThread::name() const { 1583 if (Thread::is_JavaThread_protected(/* target */ this)) { 1584 // The target JavaThread is protected so get_thread_name_string() is safe: 1585 return get_thread_name_string(); 1586 } 1587 1588 // The target JavaThread is not protected so we return the default: 1589 return Thread::name(); 1590 } 1591 1592 // Returns a non-null representation of this thread's name, or a suitable 1593 // descriptive string if there is no set name. 1594 const char* JavaThread::get_thread_name_string(char* buf, int buflen) const { 1595 const char* name_str; 1596 #ifdef ASSERT 1597 Thread* current = Thread::current_or_null_safe(); 1598 assert(current != nullptr, "cannot be called by a detached thread"); 1599 if (!current->is_Java_thread() || JavaThread::cast(current)->is_oop_safe()) { 1600 // Only access threadObj() if current thread is not a JavaThread 1601 // or if it is a JavaThread that can safely access oops. 1602 #endif 1603 oop thread_obj = threadObj(); 1604 if (thread_obj != nullptr) { 1605 oop name = java_lang_Thread::name(thread_obj); 1606 if (name != nullptr) { 1607 if (buf == nullptr) { 1608 name_str = java_lang_String::as_utf8_string(name); 1609 } else { 1610 name_str = java_lang_String::as_utf8_string(name, buf, buflen); 1611 } 1612 } else if (is_attaching_via_jni()) { // workaround for 6412693 - see 6404306 1613 name_str = "<no-name - thread is attaching>"; 1614 } else { 1615 name_str = "<un-named>"; 1616 } 1617 } else { 1618 name_str = Thread::name(); 1619 } 1620 #ifdef ASSERT 1621 } else { 1622 // Current JavaThread has exited... 1623 if (current == this) { 1624 // ... and is asking about itself: 1625 name_str = "<no-name - current JavaThread has exited>"; 1626 } else { 1627 // ... and it can't safely determine this JavaThread's name so 1628 // use the default thread name. 1629 name_str = Thread::name(); 1630 } 1631 } 1632 #endif 1633 assert(name_str != nullptr, "unexpected null thread name"); 1634 return name_str; 1635 } 1636 1637 // Helper to extract the name from the thread oop for logging. 1638 const char* JavaThread::name_for(oop thread_obj) { 1639 assert(thread_obj != nullptr, "precondition"); 1640 oop name = java_lang_Thread::name(thread_obj); 1641 const char* name_str; 1642 if (name != nullptr) { 1643 name_str = java_lang_String::as_utf8_string(name); 1644 } else { 1645 name_str = "<un-named>"; 1646 } 1647 return name_str; 1648 } 1649 1650 void JavaThread::prepare(jobject jni_thread, ThreadPriority prio) { 1651 1652 assert(Threads_lock->owner() == Thread::current(), "must have threads lock"); 1653 assert(NoPriority <= prio && prio <= MaxPriority, "sanity check"); 1654 // Link Java Thread object <-> C++ Thread 1655 1656 // Get the C++ thread object (an oop) from the JNI handle (a jthread) 1657 // and put it into a new Handle. The Handle "thread_oop" can then 1658 // be used to pass the C++ thread object to other methods. 1659 1660 // Set the Java level thread object (jthread) field of the 1661 // new thread (a JavaThread *) to C++ thread object using the 1662 // "thread_oop" handle. 1663 1664 // Set the thread field (a JavaThread *) of the 1665 // oop representing the java_lang_Thread to the new thread (a JavaThread *). 1666 1667 Handle thread_oop(Thread::current(), 1668 JNIHandles::resolve_non_null(jni_thread)); 1669 assert(InstanceKlass::cast(thread_oop->klass())->is_linked(), 1670 "must be initialized"); 1671 set_threadOopHandles(thread_oop()); 1672 1673 if (prio == NoPriority) { 1674 prio = java_lang_Thread::priority(thread_oop()); 1675 assert(prio != NoPriority, "A valid priority should be present"); 1676 } 1677 1678 // Push the Java priority down to the native thread; needs Threads_lock 1679 Thread::set_priority(this, prio); 1680 1681 // Add the new thread to the Threads list and set it in motion. 1682 // We must have threads lock in order to call Threads::add. 1683 // It is crucial that we do not block before the thread is 1684 // added to the Threads list for if a GC happens, then the java_thread oop 1685 // will not be visited by GC. 1686 Threads::add(this); 1687 // Publish the JavaThread* in java.lang.Thread after the JavaThread* is 1688 // on a ThreadsList. We don't want to wait for the release when the 1689 // Theads_lock is dropped somewhere in the caller since the JavaThread* 1690 // is already visible to JVM/TI via the ThreadsList. 1691 java_lang_Thread::release_set_thread(thread_oop(), this); 1692 } 1693 1694 oop JavaThread::current_park_blocker() { 1695 // Support for JSR-166 locks 1696 oop thread_oop = threadObj(); 1697 if (thread_oop != nullptr) { 1698 return java_lang_Thread::park_blocker(thread_oop); 1699 } 1700 return nullptr; 1701 } 1702 1703 // Print current stack trace for checked JNI warnings and JNI fatal errors. 1704 // This is the external format, selecting the platform or vthread 1705 // as applicable, and allowing for a native-only stack. 1706 void JavaThread::print_jni_stack() { 1707 assert(this == JavaThread::current(), "Can't print stack of other threads"); 1708 if (!has_last_Java_frame()) { 1709 ResourceMark rm(this); 1710 char* buf = NEW_RESOURCE_ARRAY_RETURN_NULL(char, O_BUFLEN); 1711 if (buf == nullptr) { 1712 tty->print_cr("Unable to print native stack - out of memory"); 1713 return; 1714 } 1715 address lastpc = nullptr; 1716 if (os::platform_print_native_stack(tty, nullptr, buf, O_BUFLEN, lastpc)) { 1717 // We have printed the native stack in platform-specific code, 1718 // so nothing else to do in this case. 1719 } else { 1720 frame f = os::current_frame(); 1721 VMError::print_native_stack(tty, f, this, true /*print_source_info */, 1722 -1 /* max stack */, buf, O_BUFLEN); 1723 } 1724 } else { 1725 print_active_stack_on(tty); 1726 } 1727 } 1728 1729 void JavaThread::print_stack_on(outputStream* st) { 1730 if (!has_last_Java_frame()) return; 1731 1732 Thread* current_thread = Thread::current(); 1733 ResourceMark rm(current_thread); 1734 HandleMark hm(current_thread); 1735 1736 RegisterMap reg_map(this, 1737 RegisterMap::UpdateMap::include, 1738 RegisterMap::ProcessFrames::include, 1739 RegisterMap::WalkContinuation::skip); 1740 vframe* start_vf = platform_thread_last_java_vframe(®_map); 1741 int count = 0; 1742 for (vframe* f = start_vf; f != nullptr; f = f->sender()) { 1743 if (f->is_java_frame()) { 1744 javaVFrame* jvf = javaVFrame::cast(f); 1745 java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci()); 1746 1747 // Print out lock information 1748 if (JavaMonitorsInStackTrace) { 1749 jvf->print_lock_info_on(st, count); 1750 } 1751 } else { 1752 // Ignore non-Java frames 1753 } 1754 1755 // Bail-out case for too deep stacks if MaxJavaStackTraceDepth > 0 1756 count++; 1757 if (MaxJavaStackTraceDepth > 0 && MaxJavaStackTraceDepth == count) return; 1758 } 1759 } 1760 1761 void JavaThread::print_vthread_stack_on(outputStream* st) { 1762 assert(is_vthread_mounted(), "Caller should have checked this"); 1763 assert(has_last_Java_frame(), "must be"); 1764 1765 Thread* current_thread = Thread::current(); 1766 ResourceMark rm(current_thread); 1767 HandleMark hm(current_thread); 1768 1769 RegisterMap reg_map(this, 1770 RegisterMap::UpdateMap::include, 1771 RegisterMap::ProcessFrames::include, 1772 RegisterMap::WalkContinuation::include); 1773 ContinuationEntry* cont_entry = last_continuation(); 1774 vframe* start_vf = last_java_vframe(®_map); 1775 int count = 0; 1776 for (vframe* f = start_vf; f != nullptr; f = f->sender()) { 1777 // Watch for end of vthread stack 1778 if (Continuation::is_continuation_enterSpecial(f->fr())) { 1779 assert(cont_entry == Continuation::get_continuation_entry_for_entry_frame(this, f->fr()), ""); 1780 if (cont_entry->is_virtual_thread()) { 1781 break; 1782 } 1783 cont_entry = cont_entry->parent(); 1784 } 1785 if (f->is_java_frame()) { 1786 javaVFrame* jvf = javaVFrame::cast(f); 1787 java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci()); 1788 1789 // Print out lock information 1790 if (JavaMonitorsInStackTrace) { 1791 jvf->print_lock_info_on(st, count); 1792 } 1793 } else { 1794 // Ignore non-Java frames 1795 } 1796 1797 // Bail-out case for too deep stacks if MaxJavaStackTraceDepth > 0 1798 count++; 1799 if (MaxJavaStackTraceDepth > 0 && MaxJavaStackTraceDepth == count) return; 1800 } 1801 } 1802 1803 void JavaThread::print_active_stack_on(outputStream* st) { 1804 if (is_vthread_mounted()) { 1805 print_vthread_stack_on(st); 1806 } else { 1807 print_stack_on(st); 1808 } 1809 } 1810 1811 #if INCLUDE_JVMTI 1812 // Rebind JVMTI thread state from carrier to virtual or from virtual to carrier. 1813 JvmtiThreadState* JavaThread::rebind_to_jvmti_thread_state_of(oop thread_oop) { 1814 set_jvmti_vthread(thread_oop); 1815 1816 // unbind current JvmtiThreadState from JavaThread 1817 JvmtiThreadState::unbind_from(jvmti_thread_state(), this); 1818 1819 // bind new JvmtiThreadState to JavaThread 1820 JvmtiThreadState::bind_to(java_lang_Thread::jvmti_thread_state(thread_oop), this); 1821 1822 return jvmti_thread_state(); 1823 } 1824 #endif 1825 1826 // JVMTI PopFrame support 1827 void JavaThread::popframe_preserve_args(ByteSize size_in_bytes, void* start) { 1828 assert(_popframe_preserved_args == nullptr, "should not wipe out old PopFrame preserved arguments"); 1829 if (in_bytes(size_in_bytes) != 0) { 1830 _popframe_preserved_args = NEW_C_HEAP_ARRAY(char, in_bytes(size_in_bytes), mtThread); 1831 _popframe_preserved_args_size = in_bytes(size_in_bytes); 1832 Copy::conjoint_jbytes(start, _popframe_preserved_args, _popframe_preserved_args_size); 1833 } 1834 } 1835 1836 void* JavaThread::popframe_preserved_args() { 1837 return _popframe_preserved_args; 1838 } 1839 1840 ByteSize JavaThread::popframe_preserved_args_size() { 1841 return in_ByteSize(_popframe_preserved_args_size); 1842 } 1843 1844 WordSize JavaThread::popframe_preserved_args_size_in_words() { 1845 int sz = in_bytes(popframe_preserved_args_size()); 1846 assert(sz % wordSize == 0, "argument size must be multiple of wordSize"); 1847 return in_WordSize(sz / wordSize); 1848 } 1849 1850 void JavaThread::popframe_free_preserved_args() { 1851 assert(_popframe_preserved_args != nullptr, "should not free PopFrame preserved arguments twice"); 1852 FREE_C_HEAP_ARRAY(char, (char*)_popframe_preserved_args); 1853 _popframe_preserved_args = nullptr; 1854 _popframe_preserved_args_size = 0; 1855 } 1856 1857 #ifndef PRODUCT 1858 1859 void JavaThread::trace_frames() { 1860 tty->print_cr("[Describe stack]"); 1861 int frame_no = 1; 1862 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) { 1863 tty->print(" %d. ", frame_no++); 1864 fst.current()->print_value_on(tty, this); 1865 tty->cr(); 1866 } 1867 } 1868 1869 class PrintAndVerifyOopClosure: public OopClosure { 1870 protected: 1871 template <class T> inline void do_oop_work(T* p) { 1872 oop obj = RawAccess<>::oop_load(p); 1873 if (obj == nullptr) return; 1874 tty->print(INTPTR_FORMAT ": ", p2i(p)); 1875 if (oopDesc::is_oop_or_null(obj)) { 1876 if (obj->is_objArray()) { 1877 tty->print_cr("valid objArray: " INTPTR_FORMAT, p2i(obj)); 1878 } else { 1879 obj->print(); 1880 } 1881 } else { 1882 tty->print_cr("invalid oop: " INTPTR_FORMAT, p2i(obj)); 1883 } 1884 tty->cr(); 1885 } 1886 public: 1887 virtual void do_oop(oop* p) { do_oop_work(p); } 1888 virtual void do_oop(narrowOop* p) { do_oop_work(p); } 1889 }; 1890 1891 #ifdef ASSERT 1892 // Print or validate the layout of stack frames 1893 void JavaThread::print_frame_layout(int depth, bool validate_only) { 1894 ResourceMark rm; 1895 PreserveExceptionMark pm(this); 1896 FrameValues values; 1897 int frame_no = 0; 1898 for (StackFrameStream fst(this, true, true, true); !fst.is_done(); fst.next()) { 1899 fst.current()->describe(values, ++frame_no, fst.register_map()); 1900 if (depth == frame_no) break; 1901 } 1902 Continuation::describe(values); 1903 if (validate_only) { 1904 values.validate(); 1905 } else { 1906 tty->print_cr("[Describe stack layout]"); 1907 values.print(this); 1908 } 1909 } 1910 #endif 1911 1912 void JavaThread::trace_stack_from(vframe* start_vf) { 1913 ResourceMark rm; 1914 int vframe_no = 1; 1915 for (vframe* f = start_vf; f; f = f->sender()) { 1916 if (f->is_java_frame()) { 1917 javaVFrame::cast(f)->print_activation(vframe_no++); 1918 } else { 1919 f->print(); 1920 } 1921 if (vframe_no > StackPrintLimit) { 1922 tty->print_cr("...<more frames>..."); 1923 return; 1924 } 1925 } 1926 } 1927 1928 1929 void JavaThread::trace_stack() { 1930 if (!has_last_Java_frame()) return; 1931 Thread* current_thread = Thread::current(); 1932 ResourceMark rm(current_thread); 1933 HandleMark hm(current_thread); 1934 RegisterMap reg_map(this, 1935 RegisterMap::UpdateMap::include, 1936 RegisterMap::ProcessFrames::include, 1937 RegisterMap::WalkContinuation::skip); 1938 trace_stack_from(last_java_vframe(®_map)); 1939 } 1940 1941 1942 #endif // PRODUCT 1943 1944 void JavaThread::inc_held_monitor_count(int i, bool jni) { 1945 #ifdef SUPPORT_MONITOR_COUNT 1946 assert(_held_monitor_count >= 0, "Must always be greater than 0: " INT64_FORMAT, (int64_t)_held_monitor_count); 1947 _held_monitor_count += i; 1948 if (jni) { 1949 assert(_jni_monitor_count >= 0, "Must always be greater than 0: " INT64_FORMAT, (int64_t)_jni_monitor_count); 1950 _jni_monitor_count += i; 1951 } 1952 #endif 1953 } 1954 1955 void JavaThread::dec_held_monitor_count(int i, bool jni) { 1956 #ifdef SUPPORT_MONITOR_COUNT 1957 _held_monitor_count -= i; 1958 assert(_held_monitor_count >= 0, "Must always be greater than 0: " INT64_FORMAT, (int64_t)_held_monitor_count); 1959 if (jni) { 1960 _jni_monitor_count -= i; 1961 assert(_jni_monitor_count >= 0, "Must always be greater than 0: " INT64_FORMAT, (int64_t)_jni_monitor_count); 1962 } 1963 #endif 1964 } 1965 1966 frame JavaThread::vthread_last_frame() { 1967 assert (is_vthread_mounted(), "Virtual thread not mounted"); 1968 return last_frame(); 1969 } 1970 1971 frame JavaThread::carrier_last_frame(RegisterMap* reg_map) { 1972 const ContinuationEntry* entry = vthread_continuation(); 1973 guarantee (entry != nullptr, "Not a carrier thread"); 1974 frame f = entry->to_frame(); 1975 if (reg_map->process_frames()) { 1976 entry->flush_stack_processing(this); 1977 } 1978 entry->update_register_map(reg_map); 1979 return f.sender(reg_map); 1980 } 1981 1982 frame JavaThread::platform_thread_last_frame(RegisterMap* reg_map) { 1983 return is_vthread_mounted() ? carrier_last_frame(reg_map) : last_frame(); 1984 } 1985 1986 javaVFrame* JavaThread::last_java_vframe(const frame f, RegisterMap *reg_map) { 1987 assert(reg_map != nullptr, "a map must be given"); 1988 for (vframe* vf = vframe::new_vframe(&f, reg_map, this); vf; vf = vf->sender()) { 1989 if (vf->is_java_frame()) return javaVFrame::cast(vf); 1990 } 1991 return nullptr; 1992 } 1993 1994 Klass* JavaThread::security_get_caller_class(int depth) { 1995 ResetNoHandleMark rnhm; 1996 HandleMark hm(Thread::current()); 1997 1998 vframeStream vfst(this); 1999 vfst.security_get_caller_frame(depth); 2000 if (!vfst.at_end()) { 2001 return vfst.method()->method_holder(); 2002 } 2003 return nullptr; 2004 } 2005 2006 // Internal convenience function for millisecond resolution sleeps. 2007 bool JavaThread::sleep(jlong millis) { 2008 jlong nanos; 2009 if (millis > max_jlong / NANOUNITS_PER_MILLIUNIT) { 2010 // Conversion to nanos would overflow, saturate at max 2011 nanos = max_jlong; 2012 } else { 2013 nanos = millis * NANOUNITS_PER_MILLIUNIT; 2014 } 2015 return sleep_nanos(nanos); 2016 } 2017 2018 // java.lang.Thread.sleep support 2019 // Returns true if sleep time elapsed as expected, and false 2020 // if the thread was interrupted. 2021 bool JavaThread::sleep_nanos(jlong nanos) { 2022 assert(this == Thread::current(), "thread consistency check"); 2023 assert(nanos >= 0, "nanos are in range"); 2024 2025 ParkEvent * const slp = this->_SleepEvent; 2026 // Because there can be races with thread interruption sending an unpark() 2027 // to the event, we explicitly reset it here to avoid an immediate return. 2028 // The actual interrupt state will be checked before we park(). 2029 slp->reset(); 2030 // Thread interruption establishes a happens-before ordering in the 2031 // Java Memory Model, so we need to ensure we synchronize with the 2032 // interrupt state. 2033 OrderAccess::fence(); 2034 2035 jlong prevtime = os::javaTimeNanos(); 2036 2037 jlong nanos_remaining = nanos; 2038 2039 for (;;) { 2040 // interruption has precedence over timing out 2041 if (this->is_interrupted(true)) { 2042 return false; 2043 } 2044 2045 if (nanos_remaining <= 0) { 2046 return true; 2047 } 2048 2049 { 2050 ThreadBlockInVM tbivm(this); 2051 OSThreadWaitState osts(this->osthread(), false /* not Object.wait() */); 2052 slp->park_nanos(nanos_remaining); 2053 } 2054 2055 // Update elapsed time tracking 2056 jlong newtime = os::javaTimeNanos(); 2057 if (newtime - prevtime < 0) { 2058 // time moving backwards, should only happen if no monotonic clock 2059 // not a guarantee() because JVM should not abort on kernel/glibc bugs 2060 assert(false, 2061 "unexpected time moving backwards detected in JavaThread::sleep()"); 2062 } else { 2063 nanos_remaining -= (newtime - prevtime); 2064 } 2065 prevtime = newtime; 2066 } 2067 } 2068 2069 // Last thread running calls java.lang.Shutdown.shutdown() 2070 void JavaThread::invoke_shutdown_hooks() { 2071 HandleMark hm(this); 2072 2073 // We could get here with a pending exception, if so clear it now. 2074 if (this->has_pending_exception()) { 2075 this->clear_pending_exception(); 2076 } 2077 2078 EXCEPTION_MARK; 2079 Klass* shutdown_klass = 2080 SystemDictionary::resolve_or_null(vmSymbols::java_lang_Shutdown(), 2081 THREAD); 2082 if (shutdown_klass != nullptr) { 2083 // SystemDictionary::resolve_or_null will return null if there was 2084 // an exception. If we cannot load the Shutdown class, just don't 2085 // call Shutdown.shutdown() at all. This will mean the shutdown hooks 2086 // won't be run. Note that if a shutdown hook was registered, 2087 // the Shutdown class would have already been loaded 2088 // (Runtime.addShutdownHook will load it). 2089 JavaValue result(T_VOID); 2090 JavaCalls::call_static(&result, 2091 shutdown_klass, 2092 vmSymbols::shutdown_name(), 2093 vmSymbols::void_method_signature(), 2094 THREAD); 2095 } 2096 CLEAR_PENDING_EXCEPTION; 2097 } 2098 2099 #ifndef PRODUCT 2100 void JavaThread::verify_cross_modify_fence_failure(JavaThread *thread) { 2101 report_vm_error(__FILE__, __LINE__, "Cross modify fence failure", "%p", thread); 2102 } 2103 #endif 2104 2105 // Helper function to create the java.lang.Thread object for a 2106 // VM-internal thread. The thread will have the given name, and be 2107 // a member of the "system" ThreadGroup. 2108 Handle JavaThread::create_system_thread_object(const char* name, TRAPS) { 2109 Handle string = java_lang_String::create_from_str(name, CHECK_NH); 2110 2111 // Initialize thread_oop to put it into the system threadGroup. 2112 // This is done by calling the Thread(ThreadGroup group, String name) constructor. 2113 Handle thread_group(THREAD, Universe::system_thread_group()); 2114 Handle thread_oop = 2115 JavaCalls::construct_new_instance(vmClasses::Thread_klass(), 2116 vmSymbols::threadgroup_string_void_signature(), 2117 thread_group, 2118 string, 2119 CHECK_NH); 2120 2121 return thread_oop; 2122 } 2123 2124 // Starts the target JavaThread as a daemon of the given priority, and 2125 // bound to the given java.lang.Thread instance. 2126 // The Threads_lock is held for the duration. 2127 void JavaThread::start_internal_daemon(JavaThread* current, JavaThread* target, 2128 Handle thread_oop, ThreadPriority prio) { 2129 2130 assert(target->osthread() != nullptr, "target thread is not properly initialized"); 2131 2132 MutexLocker mu(current, Threads_lock); 2133 2134 // Initialize the fields of the thread_oop first. 2135 if (prio != NoPriority) { 2136 java_lang_Thread::set_priority(thread_oop(), prio); 2137 // Note: we don't call os::set_priority here. Possibly we should, 2138 // else all threads should call it themselves when they first run. 2139 } 2140 2141 java_lang_Thread::set_daemon(thread_oop()); 2142 2143 // Now bind the thread_oop to the target JavaThread. 2144 target->set_threadOopHandles(thread_oop()); 2145 2146 Threads::add(target); // target is now visible for safepoint/handshake 2147 // Publish the JavaThread* in java.lang.Thread after the JavaThread* is 2148 // on a ThreadsList. We don't want to wait for the release when the 2149 // Theads_lock is dropped when the 'mu' destructor is run since the 2150 // JavaThread* is already visible to JVM/TI via the ThreadsList. 2151 java_lang_Thread::release_set_thread(thread_oop(), target); // isAlive == true now 2152 Thread::start(target); 2153 } 2154 2155 void JavaThread::vm_exit_on_osthread_failure(JavaThread* thread) { 2156 // At this point it may be possible that no osthread was created for the 2157 // JavaThread due to lack of resources. However, since this must work 2158 // for critical system threads just check and abort if this fails. 2159 if (thread->osthread() == nullptr) { 2160 // This isn't really an OOM condition, but historically this is what 2161 // we report. 2162 vm_exit_during_initialization("java.lang.OutOfMemoryError", 2163 os::native_thread_creation_failed_msg()); 2164 } 2165 } 2166 2167 void JavaThread::pretouch_stack() { 2168 // Given an established java thread stack with usable area followed by 2169 // shadow zone and reserved/yellow/red zone, pretouch the usable area ranging 2170 // from the current frame down to the start of the shadow zone. 2171 const address end = _stack_overflow_state.shadow_zone_safe_limit(); 2172 if (is_in_full_stack(end)) { 2173 char* p1 = (char*) alloca(1); 2174 address here = (address) &p1; 2175 if (is_in_full_stack(here) && here > end) { 2176 size_t to_alloc = here - end; 2177 char* p2 = (char*) alloca(to_alloc); 2178 log_trace(os, thread)("Pretouching thread stack from " PTR_FORMAT " to " PTR_FORMAT ".", 2179 p2i(p2), p2i(end)); 2180 os::pretouch_memory(p2, p2 + to_alloc, 2181 NOT_AIX(os::vm_page_size()) AIX_ONLY(4096)); 2182 } 2183 } 2184 } 2185 2186 // Deferred OopHandle release support. 2187 2188 class OopHandleList : public CHeapObj<mtInternal> { 2189 static const int _count = 4; 2190 OopHandle _handles[_count]; 2191 OopHandleList* _next; 2192 int _index; 2193 public: 2194 OopHandleList(OopHandleList* next) : _next(next), _index(0) {} 2195 void add(OopHandle h) { 2196 assert(_index < _count, "too many additions"); 2197 _handles[_index++] = h; 2198 } 2199 ~OopHandleList() { 2200 assert(_index == _count, "usage error"); 2201 for (int i = 0; i < _index; i++) { 2202 _handles[i].release(JavaThread::thread_oop_storage()); 2203 } 2204 } 2205 OopHandleList* next() const { return _next; } 2206 }; 2207 2208 OopHandleList* JavaThread::_oop_handle_list = nullptr; 2209 2210 // Called by the ServiceThread to do the work of releasing 2211 // the OopHandles. 2212 void JavaThread::release_oop_handles() { 2213 OopHandleList* list; 2214 { 2215 MutexLocker ml(Service_lock, Mutex::_no_safepoint_check_flag); 2216 list = _oop_handle_list; 2217 _oop_handle_list = nullptr; 2218 } 2219 assert(!SafepointSynchronize::is_at_safepoint(), "cannot be called at a safepoint"); 2220 2221 while (list != nullptr) { 2222 OopHandleList* l = list; 2223 list = l->next(); 2224 delete l; 2225 } 2226 } 2227 2228 // Add our OopHandles for later release. 2229 void JavaThread::add_oop_handles_for_release() { 2230 MutexLocker ml(Service_lock, Mutex::_no_safepoint_check_flag); 2231 OopHandleList* new_head = new OopHandleList(_oop_handle_list); 2232 new_head->add(_threadObj); 2233 new_head->add(_vthread); 2234 new_head->add(_jvmti_vthread); 2235 new_head->add(_scopedValueCache); 2236 _oop_handle_list = new_head; 2237 Service_lock->notify_all(); 2238 }