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