1 /* 2 * Copyright (c) 1997, 2024, Oracle and/or its affiliates. All rights reserved. 3 * Copyright (c) 2021, Azul Systems, Inc. All rights reserved. 4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 5 * 6 * This code is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License version 2 only, as 8 * published by the Free Software Foundation. 9 * 10 * This code is distributed in the hope that it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 13 * version 2 for more details (a copy is included in the LICENSE file that 14 * accompanied this code). 15 * 16 * You should have received a copy of the GNU General Public License version 17 * 2 along with this work; if not, write to the Free Software Foundation, 18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 19 * 20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 21 * or visit www.oracle.com if you need additional information or have any 22 * questions. 23 * 24 */ 25 26 #include "precompiled.hpp" 27 #include "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/lockStack.inline.hpp" 74 #include "runtime/mutexLocker.hpp" 75 #include "runtime/orderAccess.hpp" 76 #include "runtime/os.inline.hpp" 77 #include "runtime/osThread.hpp" 78 #include "runtime/safepoint.hpp" 79 #include "runtime/safepointMechanism.inline.hpp" 80 #include "runtime/safepointVerifiers.hpp" 81 #include "runtime/serviceThread.hpp" 82 #include "runtime/stackFrameStream.inline.hpp" 83 #include "runtime/stackWatermarkSet.hpp" 84 #include "runtime/synchronizer.hpp" 85 #include "runtime/threadCritical.hpp" 86 #include "runtime/threadIdentifier.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 // If there is a virtual thread mounted then return vthread() oop. 194 // Otherwise, return threadObj(). 195 oop JavaThread::vthread_or_thread() const { 196 oop result = vthread(); 197 if (result == nullptr) { 198 result = threadObj(); 199 } 200 return result; 201 } 202 203 oop JavaThread::scopedValueCache() const { 204 return _scopedValueCache.resolve(); 205 } 206 207 void JavaThread::set_scopedValueCache(oop p) { 208 if (!_scopedValueCache.is_empty()) { // i.e. if the OopHandle has been allocated 209 _scopedValueCache.replace(p); 210 } else { 211 assert(p == nullptr, "not yet initialized"); 212 } 213 } 214 215 void JavaThread::clear_scopedValueBindings() { 216 set_scopedValueCache(nullptr); 217 oop vthread_oop = vthread(); 218 // vthread may be null here if we get a VM error during startup, 219 // before the java.lang.Thread instance has been created. 220 if (vthread_oop != nullptr) { 221 java_lang_Thread::clear_scopedValueBindings(vthread_oop); 222 } 223 } 224 225 void JavaThread::allocate_threadObj(Handle thread_group, const char* thread_name, 226 bool daemon, TRAPS) { 227 assert(thread_group.not_null(), "thread group should be specified"); 228 assert(threadObj() == nullptr, "should only create Java thread object once"); 229 230 InstanceKlass* ik = vmClasses::Thread_klass(); 231 assert(ik->is_initialized(), "must be"); 232 instanceHandle thread_oop = ik->allocate_instance_handle(CHECK); 233 234 // We are called from jni_AttachCurrentThread/jni_AttachCurrentThreadAsDaemon. 235 // We cannot use JavaCalls::construct_new_instance because the java.lang.Thread 236 // constructor calls Thread.current(), which must be set here. 237 java_lang_Thread::set_thread(thread_oop(), this); 238 set_threadOopHandles(thread_oop()); 239 // Set the lock_id to the next thread_id temporarily while initialization runs. 240 set_lock_id(ThreadIdentifier::next()); 241 242 JavaValue result(T_VOID); 243 if (thread_name != nullptr) { 244 Handle name = java_lang_String::create_from_str(thread_name, CHECK); 245 // Thread gets assigned specified name and null target 246 JavaCalls::call_special(&result, 247 thread_oop, 248 ik, 249 vmSymbols::object_initializer_name(), 250 vmSymbols::threadgroup_string_void_signature(), 251 thread_group, 252 name, 253 CHECK); 254 } else { 255 // Thread gets assigned name "Thread-nnn" and null target 256 // (java.lang.Thread doesn't have a constructor taking only a ThreadGroup argument) 257 JavaCalls::call_special(&result, 258 thread_oop, 259 ik, 260 vmSymbols::object_initializer_name(), 261 vmSymbols::threadgroup_runnable_void_signature(), 262 thread_group, 263 Handle(), 264 CHECK); 265 } 266 // Update the lock_id with the tid value. 267 set_lock_id(java_lang_Thread::thread_id(thread_oop())); 268 269 os::set_priority(this, NormPriority); 270 271 if (daemon) { 272 java_lang_Thread::set_daemon(thread_oop()); 273 } 274 } 275 276 // ======= JavaThread ======== 277 278 #if INCLUDE_JVMCI 279 280 jlong* JavaThread::_jvmci_old_thread_counters; 281 282 static bool jvmci_counters_include(JavaThread* thread) { 283 return !JVMCICountersExcludeCompiler || !thread->is_Compiler_thread(); 284 } 285 286 void JavaThread::collect_counters(jlong* array, int length) { 287 assert(length == JVMCICounterSize, "wrong value"); 288 for (int i = 0; i < length; i++) { 289 array[i] = _jvmci_old_thread_counters[i]; 290 } 291 for (JavaThread* tp : ThreadsListHandle()) { 292 if (jvmci_counters_include(tp)) { 293 for (int i = 0; i < length; i++) { 294 array[i] += tp->_jvmci_counters[i]; 295 } 296 } 297 } 298 } 299 300 // Attempt to enlarge the array for per thread counters. 301 static jlong* resize_counters_array(jlong* old_counters, int current_size, int new_size) { 302 jlong* new_counters = NEW_C_HEAP_ARRAY_RETURN_NULL(jlong, new_size, mtJVMCI); 303 if (new_counters == nullptr) { 304 return nullptr; 305 } 306 if (old_counters == nullptr) { 307 old_counters = new_counters; 308 memset(old_counters, 0, sizeof(jlong) * new_size); 309 } else { 310 for (int i = 0; i < MIN2((int) current_size, new_size); i++) { 311 new_counters[i] = old_counters[i]; 312 } 313 if (new_size > current_size) { 314 memset(new_counters + current_size, 0, sizeof(jlong) * (new_size - current_size)); 315 } 316 FREE_C_HEAP_ARRAY(jlong, old_counters); 317 } 318 return new_counters; 319 } 320 321 // Attempt to enlarge the array for per thread counters. 322 bool JavaThread::resize_counters(int current_size, int new_size) { 323 jlong* new_counters = resize_counters_array(_jvmci_counters, current_size, new_size); 324 if (new_counters == nullptr) { 325 return false; 326 } else { 327 _jvmci_counters = new_counters; 328 return true; 329 } 330 } 331 332 class VM_JVMCIResizeCounters : public VM_Operation { 333 private: 334 int _new_size; 335 bool _failed; 336 337 public: 338 VM_JVMCIResizeCounters(int new_size) : _new_size(new_size), _failed(false) { } 339 VMOp_Type type() const { return VMOp_JVMCIResizeCounters; } 340 bool allow_nested_vm_operations() const { return true; } 341 void doit() { 342 // Resize the old thread counters array 343 jlong* new_counters = resize_counters_array(JavaThread::_jvmci_old_thread_counters, JVMCICounterSize, _new_size); 344 if (new_counters == nullptr) { 345 _failed = true; 346 return; 347 } else { 348 JavaThread::_jvmci_old_thread_counters = new_counters; 349 } 350 351 // Now resize each threads array 352 for (JavaThread* tp : ThreadsListHandle()) { 353 if (!tp->resize_counters(JVMCICounterSize, _new_size)) { 354 _failed = true; 355 break; 356 } 357 } 358 if (!_failed) { 359 JVMCICounterSize = _new_size; 360 } 361 } 362 363 bool failed() { return _failed; } 364 }; 365 366 bool JavaThread::resize_all_jvmci_counters(int new_size) { 367 VM_JVMCIResizeCounters op(new_size); 368 VMThread::execute(&op); 369 return !op.failed(); 370 } 371 372 #endif // INCLUDE_JVMCI 373 374 #ifdef ASSERT 375 // Checks safepoint allowed and clears unhandled oops at potential safepoints. 376 void JavaThread::check_possible_safepoint() { 377 if (_no_safepoint_count > 0) { 378 print_owned_locks(); 379 assert(false, "Possible safepoint reached by thread that does not allow it"); 380 } 381 #ifdef CHECK_UNHANDLED_OOPS 382 // Clear unhandled oops in JavaThreads so we get a crash right away. 383 clear_unhandled_oops(); 384 #endif // CHECK_UNHANDLED_OOPS 385 386 // Macos/aarch64 should be in the right state for safepoint (e.g. 387 // deoptimization needs WXWrite). Crashes caused by the wrong state rarely 388 // happens in practice, making such issues hard to find and reproduce. 389 #if defined(__APPLE__) && defined(AARCH64) 390 if (AssertWXAtThreadSync) { 391 assert_wx_state(WXWrite); 392 } 393 #endif 394 } 395 396 void JavaThread::check_for_valid_safepoint_state() { 397 // Don't complain if running a debugging command. 398 if (DebuggingContext::is_enabled()) return; 399 400 // Check NoSafepointVerifier, which is implied by locks taken that can be 401 // shared with the VM thread. This makes sure that no locks with allow_vm_block 402 // are held. 403 check_possible_safepoint(); 404 405 if (thread_state() != _thread_in_vm) { 406 fatal("LEAF method calling lock?"); 407 } 408 409 if (GCALotAtAllSafepoints) { 410 // We could enter a safepoint here and thus have a gc 411 InterfaceSupport::check_gc_alot(); 412 } 413 } 414 #endif // ASSERT 415 416 // A JavaThread is a normal Java thread 417 418 JavaThread::JavaThread(MEMFLAGS flags) : 419 Thread(flags), 420 // Initialize fields 421 _on_thread_list(false), 422 DEBUG_ONLY(_java_call_counter(0) COMMA) 423 _entry_point(nullptr), 424 _deopt_mark(nullptr), 425 _deopt_nmethod(nullptr), 426 _vframe_array_head(nullptr), 427 _vframe_array_last(nullptr), 428 _jvmti_deferred_updates(nullptr), 429 _callee_target(nullptr), 430 _vm_result(nullptr), 431 _vm_result_2(nullptr), 432 433 _current_pending_monitor(nullptr), 434 _current_pending_monitor_is_from_java(true), 435 _current_waiting_monitor(nullptr), 436 _active_handles(nullptr), 437 _free_handle_block(nullptr), 438 _lock_id(0), 439 _on_monitorenter(false), 440 441 _suspend_flags(0), 442 443 _thread_state(_thread_new), 444 _saved_exception_pc(nullptr), 445 #ifdef ASSERT 446 _no_safepoint_count(0), 447 _visited_for_critical_count(false), 448 #endif 449 450 _terminated(_not_terminated), 451 _in_deopt_handler(0), 452 _doing_unsafe_access(false), 453 _do_not_unlock_if_synchronized(false), 454 #if INCLUDE_JVMTI 455 _carrier_thread_suspended(false), 456 _is_in_VTMS_transition(false), 457 _is_in_tmp_VTMS_transition(false), 458 _is_disable_suspend(false), 459 _VTMS_transition_mark(false), 460 _pending_jvmti_unmount_event(false), 461 _contended_entered_monitor(nullptr), 462 #ifdef ASSERT 463 _is_VTMS_transition_disabler(false), 464 #endif 465 #endif 466 _jni_attach_state(_not_attaching_via_jni), 467 _is_in_internal_oome_mark(false), 468 #if INCLUDE_JVMCI 469 _pending_deoptimization(-1), 470 _pending_monitorenter(false), 471 _pending_transfer_to_interpreter(false), 472 _pending_failed_speculation(0), 473 _jvmci{nullptr}, 474 _libjvmci_runtime(nullptr), 475 _jvmci_counters(nullptr), 476 _jvmci_reserved0(0), 477 _jvmci_reserved1(0), 478 _jvmci_reserved_oop0(nullptr), 479 _live_nmethod(nullptr), 480 #endif // INCLUDE_JVMCI 481 482 _exception_oop(oop()), 483 _exception_pc(0), 484 _exception_handler_pc(0), 485 _is_method_handle_return(0), 486 487 _jni_active_critical(0), 488 _pending_jni_exception_check_fn(nullptr), 489 _depth_first_number(0), 490 491 // JVMTI PopFrame support 492 _popframe_condition(popframe_inactive), 493 _frames_to_pop_failed_realloc(0), 494 495 _cont_entry(nullptr), 496 _cont_fastpath(0), 497 _cont_fastpath_thread_state(1), 498 _held_monitor_count(0), 499 _jni_monitor_count(0), 500 _preempting(false), 501 _preemption_cancelled(false), 502 _pending_interrupted_exception(false), 503 _preempt_alternate_return(nullptr), 504 DEBUG_ONLY(_obj_locker_count(0) COMMA) 505 506 _handshake(this), 507 508 _popframe_preserved_args(nullptr), 509 _popframe_preserved_args_size(0), 510 511 _jvmti_thread_state(nullptr), 512 _interp_only_mode(0), 513 _should_post_on_exceptions_flag(JNI_FALSE), 514 _thread_stat(new ThreadStatistics()), 515 516 _parker(), 517 518 _class_to_be_initialized(nullptr), 519 520 _SleepEvent(ParkEvent::Allocate(this)), 521 522 _lock_stack(this) { 523 set_jni_functions(jni_functions()); 524 525 #if INCLUDE_JVMCI 526 assert(_jvmci._implicit_exception_pc == nullptr, "must be"); 527 if (JVMCICounterSize > 0) { 528 resize_counters(0, (int) JVMCICounterSize); 529 } 530 #endif // INCLUDE_JVMCI 531 532 // Setup safepoint state info for this thread 533 ThreadSafepointState::create(this); 534 535 SafepointMechanism::initialize_header(this); 536 537 set_requires_cross_modify_fence(false); 538 539 pd_initialize(); 540 assert(deferred_card_mark().is_empty(), "Default MemRegion ctor"); 541 } 542 543 JavaThread* JavaThread::create_attaching_thread() { 544 JavaThread* jt = new JavaThread(); 545 jt->_jni_attach_state = _attaching_via_jni; 546 return jt; 547 } 548 549 // interrupt support 550 551 void JavaThread::interrupt() { 552 // All callers should have 'this' thread protected by a 553 // ThreadsListHandle so that it cannot terminate and deallocate 554 // itself. 555 debug_only(check_for_dangling_thread_pointer(this);) 556 557 // For Windows _interrupt_event 558 WINDOWS_ONLY(osthread()->set_interrupted(true);) 559 560 // For Thread.sleep 561 _SleepEvent->unpark(); 562 563 // For JSR166 LockSupport.park 564 parker()->unpark(); 565 566 // For ObjectMonitor and JvmtiRawMonitor 567 _ParkEvent->unpark(); 568 } 569 570 bool JavaThread::is_interrupted(bool clear_interrupted) { 571 debug_only(check_for_dangling_thread_pointer(this);) 572 573 if (_threadObj.peek() == nullptr) { 574 // If there is no j.l.Thread then it is impossible to have 575 // been interrupted. We can find null during VM initialization 576 // or when a JNI thread is still in the process of attaching. 577 // In such cases this must be the current thread. 578 assert(this == Thread::current(), "invariant"); 579 return false; 580 } 581 582 bool interrupted = java_lang_Thread::interrupted(threadObj()); 583 584 // NOTE that since there is no "lock" around the interrupt and 585 // is_interrupted operations, there is the possibility that the 586 // interrupted flag will be "false" but that the 587 // low-level events will be in the signaled state. This is 588 // intentional. The effect of this is that Object.wait() and 589 // LockSupport.park() will appear to have a spurious wakeup, which 590 // is allowed and not harmful, and the possibility is so rare that 591 // it is not worth the added complexity to add yet another lock. 592 // For the sleep event an explicit reset is performed on entry 593 // to JavaThread::sleep, so there is no early return. It has also been 594 // recommended not to put the interrupted flag into the "event" 595 // structure because it hides the issue. 596 // Also, because there is no lock, we must only clear the interrupt 597 // state if we are going to report that we were interrupted; otherwise 598 // an interrupt that happens just after we read the field would be lost. 599 if (interrupted && clear_interrupted) { 600 assert(this == Thread::current(), "only the current thread can clear"); 601 java_lang_Thread::set_interrupted(threadObj(), false); 602 WINDOWS_ONLY(osthread()->set_interrupted(false);) 603 } 604 return interrupted; 605 } 606 607 // This is only for use by JVMTI RawMonitorWait. It emulates the actions of 608 // the Java code in Object::wait which are not present in RawMonitorWait. 609 bool JavaThread::get_and_clear_interrupted() { 610 if (!is_interrupted(false)) { 611 return false; 612 } 613 oop thread_oop = vthread_or_thread(); 614 bool is_virtual = java_lang_VirtualThread::is_instance(thread_oop); 615 616 if (!is_virtual) { 617 return is_interrupted(true); 618 } 619 // Virtual thread: clear interrupt status for both virtual and 620 // carrier threads under the interruptLock protection. 621 JavaThread* current = JavaThread::current(); 622 HandleMark hm(current); 623 Handle thread_h(current, thread_oop); 624 ObjectLocker lock(Handle(current, java_lang_Thread::interrupt_lock(thread_h())), current); 625 626 // re-check the interrupt status under the interruptLock protection 627 bool interrupted = java_lang_Thread::interrupted(thread_h()); 628 629 if (interrupted) { 630 assert(this == Thread::current(), "only the current thread can clear"); 631 java_lang_Thread::set_interrupted(thread_h(), false); // clear for virtual 632 java_lang_Thread::set_interrupted(threadObj(), false); // clear for carrier 633 WINDOWS_ONLY(osthread()->set_interrupted(false);) 634 } 635 return interrupted; 636 } 637 638 void JavaThread::block_if_vm_exited() { 639 if (_terminated == _vm_exited) { 640 // _vm_exited is set at safepoint, and Threads_lock is never released 641 // so we will block here forever. 642 // Here we can be doing a jump from a safe state to an unsafe state without 643 // proper transition, but it happens after the final safepoint has begun so 644 // this jump won't cause any safepoint problems. 645 set_thread_state(_thread_in_vm); 646 Threads_lock->lock(); 647 ShouldNotReachHere(); 648 } 649 } 650 651 JavaThread::JavaThread(ThreadFunction entry_point, size_t stack_sz, MEMFLAGS flags) : JavaThread(flags) { 652 set_entry_point(entry_point); 653 // Create the native thread itself. 654 // %note runtime_23 655 os::ThreadType thr_type = os::java_thread; 656 thr_type = entry_point == &CompilerThread::thread_entry ? os::compiler_thread : 657 os::java_thread; 658 os::create_thread(this, thr_type, stack_sz); 659 // The _osthread may be null here because we ran out of memory (too many threads active). 660 // We need to throw and OutOfMemoryError - however we cannot do this here because the caller 661 // may hold a lock and all locks must be unlocked before throwing the exception (throwing 662 // the exception consists of creating the exception object & initializing it, initialization 663 // will leave the VM via a JavaCall and then all locks must be unlocked). 664 // 665 // The thread is still suspended when we reach here. Thread must be explicit started 666 // by creator! Furthermore, the thread must also explicitly be added to the Threads list 667 // by calling Threads:add. The reason why this is not done here, is because the thread 668 // object must be fully initialized (take a look at JVM_Start) 669 } 670 671 JavaThread::~JavaThread() { 672 673 // Enqueue OopHandles for release by the service thread. 674 add_oop_handles_for_release(); 675 676 // Return the sleep event to the free list 677 ParkEvent::Release(_SleepEvent); 678 _SleepEvent = nullptr; 679 680 // Free any remaining previous UnrollBlock 681 vframeArray* old_array = vframe_array_last(); 682 683 if (old_array != nullptr) { 684 Deoptimization::UnrollBlock* old_info = old_array->unroll_block(); 685 old_array->set_unroll_block(nullptr); 686 delete old_info; 687 delete old_array; 688 } 689 690 JvmtiDeferredUpdates* updates = deferred_updates(); 691 if (updates != nullptr) { 692 // This can only happen if thread is destroyed before deoptimization occurs. 693 assert(updates->count() > 0, "Updates holder not deleted"); 694 // free deferred updates. 695 delete updates; 696 set_deferred_updates(nullptr); 697 } 698 699 // All Java related clean up happens in exit 700 ThreadSafepointState::destroy(this); 701 if (_thread_stat != nullptr) delete _thread_stat; 702 703 #if INCLUDE_JVMCI 704 if (JVMCICounterSize > 0) { 705 FREE_C_HEAP_ARRAY(jlong, _jvmci_counters); 706 } 707 #endif // INCLUDE_JVMCI 708 } 709 710 711 // First JavaThread specific code executed by a new Java thread. 712 void JavaThread::pre_run() { 713 // empty - see comments in run() 714 } 715 716 // The main routine called by a new Java thread. This isn't overridden 717 // by subclasses, instead different subclasses define a different "entry_point" 718 // which defines the actual logic for that kind of thread. 719 void JavaThread::run() { 720 // initialize thread-local alloc buffer related fields 721 initialize_tlab(); 722 723 _stack_overflow_state.create_stack_guard_pages(); 724 725 cache_global_variables(); 726 727 // Thread is now sufficiently initialized to be handled by the safepoint code as being 728 // in the VM. Change thread state from _thread_new to _thread_in_vm 729 assert(this->thread_state() == _thread_new, "wrong thread state"); 730 set_thread_state(_thread_in_vm); 731 732 // Before a thread is on the threads list it is always safe, so after leaving the 733 // _thread_new we should emit a instruction barrier. The distance to modified code 734 // from here is probably far enough, but this is consistent and safe. 735 OrderAccess::cross_modify_fence(); 736 737 assert(JavaThread::current() == this, "sanity check"); 738 assert(!Thread::current()->owns_locks(), "sanity check"); 739 740 DTRACE_THREAD_PROBE(start, this); 741 742 // This operation might block. We call that after all safepoint checks for a new thread has 743 // been completed. 744 set_active_handles(JNIHandleBlock::allocate_block()); 745 746 if (JvmtiExport::should_post_thread_life()) { 747 JvmtiExport::post_thread_start(this); 748 749 } 750 751 if (AlwaysPreTouchStacks) { 752 pretouch_stack(); 753 } 754 755 // We call another function to do the rest so we are sure that the stack addresses used 756 // from there will be lower than the stack base just computed. 757 thread_main_inner(); 758 } 759 760 void JavaThread::thread_main_inner() { 761 assert(JavaThread::current() == this, "sanity check"); 762 assert(_threadObj.peek() != nullptr, "just checking"); 763 764 // Execute thread entry point unless this thread has a pending exception. 765 // Note: Due to JVMTI StopThread we can have pending exceptions already! 766 if (!this->has_pending_exception()) { 767 { 768 ResourceMark rm(this); 769 this->set_native_thread_name(this->name()); 770 } 771 HandleMark hm(this); 772 this->entry_point()(this, this); 773 } 774 775 DTRACE_THREAD_PROBE(stop, this); 776 777 // Cleanup is handled in post_run() 778 } 779 780 // Shared teardown for all JavaThreads 781 void JavaThread::post_run() { 782 this->exit(false); 783 this->unregister_thread_stack_with_NMT(); 784 // Defer deletion to here to ensure 'this' is still referenceable in call_run 785 // for any shared tear-down. 786 this->smr_delete(); 787 } 788 789 static void ensure_join(JavaThread* thread) { 790 // We do not need to grab the Threads_lock, since we are operating on ourself. 791 Handle threadObj(thread, thread->threadObj()); 792 assert(threadObj.not_null(), "java thread object must exist"); 793 ObjectLocker lock(threadObj, thread); 794 // Thread is exiting. So set thread_status field in java.lang.Thread class to TERMINATED. 795 java_lang_Thread::set_thread_status(threadObj(), JavaThreadStatus::TERMINATED); 796 // Clear the native thread instance - this makes isAlive return false and allows the join() 797 // to complete once we've done the notify_all below. Needs a release() to obey Java Memory Model 798 // requirements. 799 assert(java_lang_Thread::thread(threadObj()) == thread, "must be alive"); 800 java_lang_Thread::release_set_thread(threadObj(), nullptr); 801 lock.notify_all(thread); 802 // Ignore pending exception, since we are exiting anyway 803 thread->clear_pending_exception(); 804 } 805 806 static bool is_daemon(oop threadObj) { 807 return (threadObj != nullptr && java_lang_Thread::is_daemon(threadObj)); 808 } 809 810 // For any new cleanup additions, please check to see if they need to be applied to 811 // cleanup_failed_attach_current_thread as well. 812 void JavaThread::exit(bool destroy_vm, ExitType exit_type) { 813 assert(this == JavaThread::current(), "thread consistency check"); 814 assert(!is_exiting(), "should not be exiting or terminated already"); 815 816 elapsedTimer _timer_exit_phase1; 817 elapsedTimer _timer_exit_phase2; 818 elapsedTimer _timer_exit_phase3; 819 elapsedTimer _timer_exit_phase4; 820 821 if (log_is_enabled(Debug, os, thread, timer)) { 822 _timer_exit_phase1.start(); 823 } 824 825 HandleMark hm(this); 826 Handle uncaught_exception(this, this->pending_exception()); 827 this->clear_pending_exception(); 828 Handle threadObj(this, this->threadObj()); 829 assert(threadObj.not_null(), "Java thread object should be created"); 830 831 if (!destroy_vm) { 832 if (uncaught_exception.not_null()) { 833 EXCEPTION_MARK; 834 // Call method Thread.dispatchUncaughtException(). 835 Klass* thread_klass = vmClasses::Thread_klass(); 836 JavaValue result(T_VOID); 837 JavaCalls::call_virtual(&result, 838 threadObj, thread_klass, 839 vmSymbols::dispatchUncaughtException_name(), 840 vmSymbols::throwable_void_signature(), 841 uncaught_exception, 842 THREAD); 843 if (HAS_PENDING_EXCEPTION) { 844 ResourceMark rm(this); 845 jio_fprintf(defaultStream::error_stream(), 846 "\nException: %s thrown from the UncaughtExceptionHandler" 847 " in thread \"%s\"\n", 848 pending_exception()->klass()->external_name(), 849 name()); 850 CLEAR_PENDING_EXCEPTION; 851 } 852 } 853 854 if (!is_Compiler_thread()) { 855 // We have finished executing user-defined Java code and now have to do the 856 // implementation specific clean-up by calling Thread.exit(). We prevent any 857 // asynchronous exceptions from being delivered while in Thread.exit() 858 // to ensure the clean-up is not corrupted. 859 NoAsyncExceptionDeliveryMark _no_async(this); 860 861 EXCEPTION_MARK; 862 JavaValue result(T_VOID); 863 Klass* thread_klass = vmClasses::Thread_klass(); 864 JavaCalls::call_virtual(&result, 865 threadObj, thread_klass, 866 vmSymbols::exit_method_name(), 867 vmSymbols::void_method_signature(), 868 THREAD); 869 CLEAR_PENDING_EXCEPTION; 870 } 871 872 // notify JVMTI 873 if (JvmtiExport::should_post_thread_life()) { 874 JvmtiExport::post_thread_end(this); 875 } 876 } else { 877 // before_exit() has already posted JVMTI THREAD_END events 878 } 879 880 // Cleanup any pending async exception now since we cannot access oops after 881 // BarrierSet::barrier_set()->on_thread_detach() has been executed. 882 if (has_async_exception_condition()) { 883 handshake_state()->clean_async_exception_operation(); 884 } 885 886 // The careful dance between thread suspension and exit is handled here. 887 // Since we are in thread_in_vm state and suspension is done with handshakes, 888 // we can just put in the exiting state and it will be correctly handled. 889 // Also, no more async exceptions will be added to the queue after this point. 890 set_terminated(_thread_exiting); 891 ThreadService::current_thread_exiting(this, is_daemon(threadObj())); 892 893 if (log_is_enabled(Debug, os, thread, timer)) { 894 _timer_exit_phase1.stop(); 895 _timer_exit_phase2.start(); 896 } 897 898 // Capture daemon status before the thread is marked as terminated. 899 bool daemon = is_daemon(threadObj()); 900 901 // Notify waiters on thread object. This has to be done after exit() is called 902 // on the thread (if the thread is the last thread in a daemon ThreadGroup the 903 // group should have the destroyed bit set before waiters are notified). 904 ensure_join(this); 905 assert(!this->has_pending_exception(), "ensure_join should have cleared"); 906 907 if (log_is_enabled(Debug, os, thread, timer)) { 908 _timer_exit_phase2.stop(); 909 _timer_exit_phase3.start(); 910 } 911 // 6282335 JNI DetachCurrentThread spec states that all Java monitors 912 // held by this thread must be released. The spec does not distinguish 913 // between JNI-acquired and regular Java monitors. We can only see 914 // regular Java monitors here if monitor enter-exit matching is broken. 915 // 916 // ensure_join() ignores IllegalThreadStateExceptions, and so does 917 // ObjectSynchronizer::release_monitors_owned_by_thread(). 918 if (exit_type == jni_detach) { 919 // Sanity check even though JNI DetachCurrentThread() would have 920 // returned JNI_ERR if there was a Java frame. JavaThread exit 921 // should be done executing Java code by the time we get here. 922 assert(!this->has_last_Java_frame(), 923 "should not have a Java frame when detaching or exiting"); 924 ObjectSynchronizer::release_monitors_owned_by_thread(this); 925 assert(!this->has_pending_exception(), "release_monitors should have cleared"); 926 // Check for monitor counts being out of sync. 927 assert(held_monitor_count() == jni_monitor_count(), 928 "held monitor count should be equal to jni: " INTX_FORMAT " != " INTX_FORMAT, 929 held_monitor_count(), jni_monitor_count()); 930 // All in-use monitors, including JNI-locked ones, should have been released above. 931 assert(held_monitor_count() == 0, "Failed to unlock " INTX_FORMAT " object monitors", 932 held_monitor_count()); 933 } else { 934 // Check for monitor counts being out of sync. 935 assert(held_monitor_count() == jni_monitor_count(), 936 "held monitor count should be equal to jni: " INTX_FORMAT " != " INTX_FORMAT, 937 held_monitor_count(), jni_monitor_count()); 938 // It is possible that a terminating thread failed to unlock monitors it locked 939 // via JNI so we don't assert the count is zero. 940 } 941 942 if (CheckJNICalls && jni_monitor_count() > 0) { 943 // We would like a fatal here, but due to we never checked this before there 944 // is a lot of tests which breaks, even with an error log. 945 log_debug(jni)("JavaThread %s (tid: " UINTX_FORMAT ") with Objects still locked by JNI MonitorEnter.", 946 exit_type == JavaThread::normal_exit ? "exiting" : "detaching", os::current_thread_id()); 947 } 948 assert(obj_locker_count() == 0, "expected 0 but found: " INTX_FORMAT, obj_locker_count()); 949 950 // These things needs to be done while we are still a Java Thread. Make sure that thread 951 // is in a consistent state, in case GC happens 952 JFR_ONLY(Jfr::on_thread_exit(this);) 953 954 if (active_handles() != nullptr) { 955 JNIHandleBlock* block = active_handles(); 956 set_active_handles(nullptr); 957 JNIHandleBlock::release_block(block); 958 } 959 960 if (free_handle_block() != nullptr) { 961 JNIHandleBlock* block = free_handle_block(); 962 set_free_handle_block(nullptr); 963 JNIHandleBlock::release_block(block); 964 } 965 966 // These have to be removed while this is still a valid thread. 967 _stack_overflow_state.remove_stack_guard_pages(); 968 969 if (UseTLAB) { 970 tlab().retire(); 971 } 972 973 if (JvmtiEnv::environments_might_exist()) { 974 JvmtiExport::cleanup_thread(this); 975 } 976 977 // We need to cache the thread name for logging purposes below as once 978 // we have called on_thread_detach this thread must not access any oops. 979 char* thread_name = nullptr; 980 if (log_is_enabled(Debug, os, thread, timer)) { 981 ResourceMark rm(this); 982 thread_name = os::strdup(name()); 983 } 984 985 if (log_is_enabled(Info, os, thread)) { 986 ResourceMark rm(this); 987 log_info(os, thread)("JavaThread %s (name: \"%s\", tid: " UINTX_FORMAT ").", 988 exit_type == JavaThread::normal_exit ? "exiting" : "detaching", 989 name(), os::current_thread_id()); 990 } 991 992 if (log_is_enabled(Debug, os, thread, timer)) { 993 _timer_exit_phase3.stop(); 994 _timer_exit_phase4.start(); 995 } 996 997 #if INCLUDE_JVMCI 998 if (JVMCICounterSize > 0) { 999 if (jvmci_counters_include(this)) { 1000 for (int i = 0; i < JVMCICounterSize; i++) { 1001 _jvmci_old_thread_counters[i] += _jvmci_counters[i]; 1002 } 1003 } 1004 } 1005 #endif // INCLUDE_JVMCI 1006 1007 // Remove from list of active threads list, and notify VM thread if we are the last non-daemon thread. 1008 // We call BarrierSet::barrier_set()->on_thread_detach() here so no touching of oops after this point. 1009 Threads::remove(this, daemon); 1010 1011 if (log_is_enabled(Debug, os, thread, timer)) { 1012 _timer_exit_phase4.stop(); 1013 log_debug(os, thread, timer)("name='%s'" 1014 ", exit-phase1=" JLONG_FORMAT 1015 ", exit-phase2=" JLONG_FORMAT 1016 ", exit-phase3=" JLONG_FORMAT 1017 ", exit-phase4=" JLONG_FORMAT, 1018 thread_name, 1019 _timer_exit_phase1.milliseconds(), 1020 _timer_exit_phase2.milliseconds(), 1021 _timer_exit_phase3.milliseconds(), 1022 _timer_exit_phase4.milliseconds()); 1023 os::free(thread_name); 1024 } 1025 } 1026 1027 void JavaThread::cleanup_failed_attach_current_thread(bool is_daemon) { 1028 if (active_handles() != nullptr) { 1029 JNIHandleBlock* block = active_handles(); 1030 set_active_handles(nullptr); 1031 JNIHandleBlock::release_block(block); 1032 } 1033 1034 if (free_handle_block() != nullptr) { 1035 JNIHandleBlock* block = free_handle_block(); 1036 set_free_handle_block(nullptr); 1037 JNIHandleBlock::release_block(block); 1038 } 1039 1040 // These have to be removed while this is still a valid thread. 1041 _stack_overflow_state.remove_stack_guard_pages(); 1042 1043 if (UseTLAB) { 1044 tlab().retire(); 1045 } 1046 1047 Threads::remove(this, is_daemon); 1048 this->smr_delete(); 1049 } 1050 1051 JavaThread* JavaThread::active() { 1052 Thread* thread = Thread::current(); 1053 if (thread->is_Java_thread()) { 1054 return JavaThread::cast(thread); 1055 } else { 1056 assert(thread->is_VM_thread(), "this must be a vm thread"); 1057 VM_Operation* op = ((VMThread*) thread)->vm_operation(); 1058 JavaThread *ret = op == nullptr ? nullptr : JavaThread::cast(op->calling_thread()); 1059 return ret; 1060 } 1061 } 1062 1063 bool JavaThread::is_lock_owned(address adr) const { 1064 assert(LockingMode != LM_LIGHTWEIGHT, "should not be called with new lightweight locking"); 1065 return is_in_full_stack(adr); 1066 } 1067 1068 oop JavaThread::exception_oop() const { 1069 return Atomic::load(&_exception_oop); 1070 } 1071 1072 void JavaThread::set_exception_oop(oop o) { 1073 Atomic::store(&_exception_oop, o); 1074 } 1075 1076 void JavaThread::handle_special_runtime_exit_condition() { 1077 if (is_obj_deopt_suspend()) { 1078 frame_anchor()->make_walkable(); 1079 wait_for_object_deoptimization(); 1080 } 1081 JFR_ONLY(SUSPEND_THREAD_CONDITIONAL(this);) 1082 } 1083 1084 1085 // Asynchronous exceptions support 1086 // 1087 void JavaThread::handle_async_exception(oop java_throwable) { 1088 assert(java_throwable != nullptr, "should have an _async_exception to throw"); 1089 assert(!is_at_poll_safepoint(), "should have never called this method"); 1090 1091 if (has_last_Java_frame()) { 1092 frame f = last_frame(); 1093 if (f.is_runtime_frame()) { 1094 // If the topmost frame is a runtime stub, then we are calling into 1095 // OptoRuntime from compiled code. Some runtime stubs (new, monitor_exit..) 1096 // must deoptimize the caller before continuing, as the compiled exception 1097 // handler table may not be valid. 1098 RegisterMap reg_map(this, 1099 RegisterMap::UpdateMap::skip, 1100 RegisterMap::ProcessFrames::include, 1101 RegisterMap::WalkContinuation::skip); 1102 frame compiled_frame = f.sender(®_map); 1103 if (!StressCompiledExceptionHandlers && compiled_frame.can_be_deoptimized()) { 1104 Deoptimization::deoptimize(this, compiled_frame); 1105 } 1106 } 1107 } 1108 1109 // We cannot call Exceptions::_throw(...) here because we cannot block 1110 set_pending_exception(java_throwable, __FILE__, __LINE__); 1111 1112 clear_scopedValueBindings(); 1113 1114 LogTarget(Info, exceptions) lt; 1115 if (lt.is_enabled()) { 1116 ResourceMark rm; 1117 LogStream ls(lt); 1118 ls.print("Async. exception installed at runtime exit (" INTPTR_FORMAT ")", p2i(this)); 1119 if (has_last_Java_frame()) { 1120 frame f = last_frame(); 1121 ls.print(" (pc: " INTPTR_FORMAT " sp: " INTPTR_FORMAT " )", p2i(f.pc()), p2i(f.sp())); 1122 } 1123 ls.print_cr(" of type: %s", java_throwable->klass()->external_name()); 1124 } 1125 } 1126 1127 void JavaThread::install_async_exception(AsyncExceptionHandshake* aeh) { 1128 // Do not throw asynchronous exceptions against the compiler thread 1129 // or if the thread is already exiting. 1130 if (!can_call_java() || is_exiting()) { 1131 delete aeh; 1132 return; 1133 } 1134 1135 oop exception = aeh->exception(); 1136 Handshake::execute(aeh, this); // Install asynchronous handshake 1137 1138 ResourceMark rm; 1139 if (log_is_enabled(Info, exceptions)) { 1140 log_info(exceptions)("Pending Async. exception installed of type: %s", 1141 InstanceKlass::cast(exception->klass())->external_name()); 1142 } 1143 // for AbortVMOnException flag 1144 Exceptions::debug_check_abort(exception->klass()->external_name()); 1145 1146 oop vt_oop = vthread(); 1147 if (vt_oop == nullptr || !vt_oop->is_a(vmClasses::BaseVirtualThread_klass())) { 1148 // Interrupt thread so it will wake up from a potential wait()/sleep()/park() 1149 java_lang_Thread::set_interrupted(threadObj(), true); 1150 this->interrupt(); 1151 } 1152 } 1153 1154 class InstallAsyncExceptionHandshake : public HandshakeClosure { 1155 AsyncExceptionHandshake* _aeh; 1156 public: 1157 InstallAsyncExceptionHandshake(AsyncExceptionHandshake* aeh) : 1158 HandshakeClosure("InstallAsyncException"), _aeh(aeh) {} 1159 ~InstallAsyncExceptionHandshake() { 1160 // If InstallAsyncExceptionHandshake was never executed we need to clean up _aeh. 1161 delete _aeh; 1162 } 1163 void do_thread(Thread* thr) { 1164 JavaThread* target = JavaThread::cast(thr); 1165 target->install_async_exception(_aeh); 1166 _aeh = nullptr; 1167 } 1168 }; 1169 1170 void JavaThread::send_async_exception(JavaThread* target, oop java_throwable) { 1171 OopHandle e(Universe::vm_global(), java_throwable); 1172 InstallAsyncExceptionHandshake iaeh(new AsyncExceptionHandshake(e)); 1173 Handshake::execute(&iaeh, target); 1174 } 1175 1176 #if INCLUDE_JVMTI 1177 void JavaThread::set_is_in_VTMS_transition(bool val) { 1178 assert(is_in_VTMS_transition() != val, "already %s transition", val ? "inside" : "outside"); 1179 _is_in_VTMS_transition = val; 1180 } 1181 1182 #ifdef ASSERT 1183 void JavaThread::set_is_VTMS_transition_disabler(bool val) { 1184 _is_VTMS_transition_disabler = val; 1185 } 1186 #endif 1187 #endif 1188 1189 // External suspension mechanism. 1190 // 1191 // Guarantees on return (for a valid target thread): 1192 // - Target thread will not execute any new bytecode. 1193 // - Target thread will not enter any new monitors. 1194 // 1195 bool JavaThread::java_suspend() { 1196 #if INCLUDE_JVMTI 1197 // Suspending a JavaThread in VTMS transition or disabling VTMS transitions can cause deadlocks. 1198 assert(!is_in_VTMS_transition(), "no suspend allowed in VTMS transition"); 1199 assert(!is_VTMS_transition_disabler(), "no suspend allowed for VTMS transition disablers"); 1200 #endif 1201 1202 guarantee(Thread::is_JavaThread_protected(/* target */ this), 1203 "target JavaThread is not protected in calling context."); 1204 return this->handshake_state()->suspend(); 1205 } 1206 1207 bool JavaThread::java_resume() { 1208 guarantee(Thread::is_JavaThread_protected_by_TLH(/* target */ this), 1209 "missing ThreadsListHandle in calling context."); 1210 return this->handshake_state()->resume(); 1211 } 1212 1213 // Wait for another thread to perform object reallocation and relocking on behalf of 1214 // this thread. The current thread is required to change to _thread_blocked in order 1215 // to be seen to be safepoint/handshake safe whilst suspended and only after becoming 1216 // handshake safe, the other thread can complete the handshake used to synchronize 1217 // with this thread and then perform the reallocation and relocking. 1218 // See EscapeBarrier::sync_and_suspend_*() 1219 1220 void JavaThread::wait_for_object_deoptimization() { 1221 assert(!has_last_Java_frame() || frame_anchor()->walkable(), "should have walkable stack"); 1222 assert(this == Thread::current(), "invariant"); 1223 1224 bool spin_wait = os::is_MP(); 1225 do { 1226 ThreadBlockInVM tbivm(this, true /* allow_suspend */); 1227 // Wait for object deoptimization if requested. 1228 if (spin_wait) { 1229 // A single deoptimization is typically very short. Microbenchmarks 1230 // showed 5% better performance when spinning. 1231 const uint spin_limit = 10 * SpinYield::default_spin_limit; 1232 SpinYield spin(spin_limit); 1233 for (uint i = 0; is_obj_deopt_suspend() && i < spin_limit; i++) { 1234 spin.wait(); 1235 } 1236 // Spin just once 1237 spin_wait = false; 1238 } else { 1239 MonitorLocker ml(this, EscapeBarrier_lock, Monitor::_no_safepoint_check_flag); 1240 if (is_obj_deopt_suspend()) { 1241 ml.wait(); 1242 } 1243 } 1244 // A handshake for obj. deoptimization suspend could have been processed so 1245 // we must check after processing. 1246 } while (is_obj_deopt_suspend()); 1247 } 1248 1249 #ifdef ASSERT 1250 // Verify the JavaThread has not yet been published in the Threads::list, and 1251 // hence doesn't need protection from concurrent access at this stage. 1252 void JavaThread::verify_not_published() { 1253 // Cannot create a ThreadsListHandle here and check !tlh.includes(this) 1254 // since an unpublished JavaThread doesn't participate in the 1255 // Thread-SMR protocol for keeping a ThreadsList alive. 1256 assert(!on_thread_list(), "JavaThread shouldn't have been published yet!"); 1257 } 1258 #endif 1259 1260 // Slow path when the native==>Java barriers detect a safepoint/handshake is 1261 // pending, when _suspend_flags is non-zero or when we need to process a stack 1262 // watermark. Also check for pending async exceptions (except unsafe access error). 1263 // Note only the native==>Java barriers can call this function when thread state 1264 // is _thread_in_native_trans. 1265 void JavaThread::check_special_condition_for_native_trans(JavaThread *thread) { 1266 assert(thread->thread_state() == _thread_in_native_trans, "wrong state"); 1267 assert(!thread->has_last_Java_frame() || thread->frame_anchor()->walkable(), "Unwalkable stack in native->Java transition"); 1268 1269 thread->set_thread_state(_thread_in_vm); 1270 1271 // Enable WXWrite: called directly from interpreter native wrapper. 1272 MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXWrite, thread)); 1273 1274 SafepointMechanism::process_if_requested_with_exit_check(thread, true /* check asyncs */); 1275 1276 // After returning from native, it could be that the stack frames are not 1277 // yet safe to use. We catch such situations in the subsequent stack watermark 1278 // barrier, which will trap unsafe stack frames. 1279 StackWatermarkSet::before_unwind(thread); 1280 } 1281 1282 #ifndef PRODUCT 1283 // Deoptimization 1284 // Function for testing deoptimization 1285 void JavaThread::deoptimize() { 1286 StackFrameStream fst(this, false /* update */, true /* process_frames */); 1287 bool deopt = false; // Dump stack only if a deopt actually happens. 1288 bool only_at = strlen(DeoptimizeOnlyAt) > 0; 1289 // Iterate over all frames in the thread and deoptimize 1290 for (; !fst.is_done(); fst.next()) { 1291 if (fst.current()->can_be_deoptimized()) { 1292 1293 if (only_at) { 1294 // Deoptimize only at particular bcis. DeoptimizeOnlyAt 1295 // consists of comma or carriage return separated numbers so 1296 // search for the current bci in that string. 1297 address pc = fst.current()->pc(); 1298 nmethod* nm = fst.current()->cb()->as_nmethod(); 1299 ScopeDesc* sd = nm->scope_desc_at(pc); 1300 char buffer[8]; 1301 jio_snprintf(buffer, sizeof(buffer), "%d", sd->bci()); 1302 size_t len = strlen(buffer); 1303 const char * found = strstr(DeoptimizeOnlyAt, buffer); 1304 while (found != nullptr) { 1305 if ((found[len] == ',' || found[len] == '\n' || found[len] == '\0') && 1306 (found == DeoptimizeOnlyAt || found[-1] == ',' || found[-1] == '\n')) { 1307 // Check that the bci found is bracketed by terminators. 1308 break; 1309 } 1310 found = strstr(found + 1, buffer); 1311 } 1312 if (!found) { 1313 continue; 1314 } 1315 } 1316 1317 if (DebugDeoptimization && !deopt) { 1318 deopt = true; // One-time only print before deopt 1319 tty->print_cr("[BEFORE Deoptimization]"); 1320 trace_frames(); 1321 trace_stack(); 1322 } 1323 Deoptimization::deoptimize(this, *fst.current()); 1324 } 1325 } 1326 1327 if (DebugDeoptimization && deopt) { 1328 tty->print_cr("[AFTER Deoptimization]"); 1329 trace_frames(); 1330 } 1331 } 1332 1333 1334 // Make zombies 1335 void JavaThread::make_zombies() { 1336 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) { 1337 if (fst.current()->can_be_deoptimized()) { 1338 // it is a Java nmethod 1339 nmethod* nm = CodeCache::find_nmethod(fst.current()->pc()); 1340 assert(nm != nullptr, "did not find nmethod"); 1341 nm->make_not_entrant(); 1342 } 1343 } 1344 } 1345 #endif // PRODUCT 1346 1347 1348 void JavaThread::deoptimize_marked_methods() { 1349 if (!has_last_Java_frame()) return; 1350 StackFrameStream fst(this, false /* update */, true /* process_frames */); 1351 for (; !fst.is_done(); fst.next()) { 1352 if (fst.current()->should_be_deoptimized()) { 1353 Deoptimization::deoptimize(this, *fst.current()); 1354 } 1355 } 1356 } 1357 1358 #ifdef ASSERT 1359 void JavaThread::verify_frame_info() { 1360 assert((!has_last_Java_frame() && java_call_counter() == 0) || 1361 (has_last_Java_frame() && java_call_counter() > 0), 1362 "unexpected frame info: has_last_frame=%s, java_call_counter=%d", 1363 has_last_Java_frame() ? "true" : "false", java_call_counter()); 1364 } 1365 #endif 1366 1367 // Push on a new block of JNI handles. 1368 void JavaThread::push_jni_handle_block() { 1369 // Allocate a new block for JNI handles. 1370 // Inlined code from jni_PushLocalFrame() 1371 JNIHandleBlock* old_handles = active_handles(); 1372 JNIHandleBlock* new_handles = JNIHandleBlock::allocate_block(this); 1373 assert(old_handles != nullptr && new_handles != nullptr, "should not be null"); 1374 new_handles->set_pop_frame_link(old_handles); // make sure java handles get gc'd. 1375 set_active_handles(new_handles); 1376 } 1377 1378 // Pop off the current block of JNI handles. 1379 void JavaThread::pop_jni_handle_block() { 1380 // Release our JNI handle block 1381 JNIHandleBlock* old_handles = active_handles(); 1382 JNIHandleBlock* new_handles = old_handles->pop_frame_link(); 1383 assert(new_handles != nullptr, "should never set active handles to null"); 1384 set_active_handles(new_handles); 1385 old_handles->set_pop_frame_link(nullptr); 1386 JNIHandleBlock::release_block(old_handles, this); 1387 } 1388 1389 void JavaThread::oops_do_no_frames(OopClosure* f, NMethodClosure* cf) { 1390 // Verify that the deferred card marks have been flushed. 1391 assert(deferred_card_mark().is_empty(), "Should be empty during GC"); 1392 1393 // Traverse the GCHandles 1394 Thread::oops_do_no_frames(f, cf); 1395 1396 if (active_handles() != nullptr) { 1397 active_handles()->oops_do(f); 1398 } 1399 1400 DEBUG_ONLY(verify_frame_info();) 1401 1402 assert(vframe_array_head() == nullptr, "deopt in progress at a safepoint!"); 1403 // If we have deferred set_locals there might be oops waiting to be 1404 // written 1405 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = JvmtiDeferredUpdates::deferred_locals(this); 1406 if (list != nullptr) { 1407 for (int i = 0; i < list->length(); i++) { 1408 list->at(i)->oops_do(f); 1409 } 1410 } 1411 1412 // Traverse instance variables at the end since the GC may be moving things 1413 // around using this function 1414 f->do_oop((oop*) &_vm_result); 1415 f->do_oop((oop*) &_exception_oop); 1416 #if INCLUDE_JVMCI 1417 f->do_oop((oop*) &_jvmci_reserved_oop0); 1418 1419 if (_live_nmethod != nullptr && cf != nullptr) { 1420 cf->do_nmethod(_live_nmethod); 1421 } 1422 #endif 1423 1424 if (jvmti_thread_state() != nullptr) { 1425 jvmti_thread_state()->oops_do(f, cf); 1426 } 1427 1428 // The continuation oops are really on the stack. But there is typically at most 1429 // one of those per thread, so we handle them here in the oops_do_no_frames part 1430 // so that we don't have to sprinkle as many stack watermark checks where these 1431 // oops are used. We just need to make sure the thread has started processing. 1432 ContinuationEntry* entry = _cont_entry; 1433 while (entry != nullptr) { 1434 f->do_oop((oop*)entry->cont_addr()); 1435 f->do_oop((oop*)entry->chunk_addr()); 1436 entry = entry->parent(); 1437 } 1438 1439 if (LockingMode == LM_LIGHTWEIGHT) { 1440 lock_stack().oops_do(f); 1441 } 1442 } 1443 1444 void JavaThread::oops_do_frames(OopClosure* f, NMethodClosure* cf) { 1445 if (!has_last_Java_frame()) { 1446 return; 1447 } 1448 // Finish any pending lazy GC activity for the frames 1449 StackWatermarkSet::finish_processing(this, nullptr /* context */, StackWatermarkKind::gc); 1450 // Traverse the execution stack 1451 for (StackFrameStream fst(this, true /* update */, false /* process_frames */); !fst.is_done(); fst.next()) { 1452 fst.current()->oops_do(f, cf, fst.register_map()); 1453 } 1454 } 1455 1456 #ifdef ASSERT 1457 void JavaThread::verify_states_for_handshake() { 1458 // This checks that the thread has a correct frame state during a handshake. 1459 verify_frame_info(); 1460 } 1461 #endif 1462 1463 void JavaThread::nmethods_do(NMethodClosure* cf) { 1464 DEBUG_ONLY(verify_frame_info();) 1465 MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXWrite, Thread::current());) 1466 1467 if (has_last_Java_frame()) { 1468 // Traverse the execution stack 1469 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) { 1470 fst.current()->nmethod_do(cf); 1471 } 1472 } 1473 1474 if (jvmti_thread_state() != nullptr) { 1475 jvmti_thread_state()->nmethods_do(cf); 1476 } 1477 1478 #if INCLUDE_JVMCI 1479 if (_live_nmethod != nullptr) { 1480 cf->do_nmethod(_live_nmethod); 1481 } 1482 #endif 1483 } 1484 1485 void JavaThread::metadata_do(MetadataClosure* f) { 1486 if (has_last_Java_frame()) { 1487 // Traverse the execution stack to call f() on the methods in the stack 1488 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) { 1489 fst.current()->metadata_do(f); 1490 } 1491 } else if (is_Compiler_thread()) { 1492 // need to walk ciMetadata in current compile tasks to keep alive. 1493 CompilerThread* ct = (CompilerThread*)this; 1494 if (ct->env() != nullptr) { 1495 ct->env()->metadata_do(f); 1496 } 1497 CompileTask* task = ct->task(); 1498 if (task != nullptr) { 1499 task->metadata_do(f); 1500 } 1501 } 1502 } 1503 1504 // Printing 1505 static const char* _get_thread_state_name(JavaThreadState _thread_state) { 1506 switch (_thread_state) { 1507 case _thread_uninitialized: return "_thread_uninitialized"; 1508 case _thread_new: return "_thread_new"; 1509 case _thread_new_trans: return "_thread_new_trans"; 1510 case _thread_in_native: return "_thread_in_native"; 1511 case _thread_in_native_trans: return "_thread_in_native_trans"; 1512 case _thread_in_vm: return "_thread_in_vm"; 1513 case _thread_in_vm_trans: return "_thread_in_vm_trans"; 1514 case _thread_in_Java: return "_thread_in_Java"; 1515 case _thread_in_Java_trans: return "_thread_in_Java_trans"; 1516 case _thread_blocked: return "_thread_blocked"; 1517 case _thread_blocked_trans: return "_thread_blocked_trans"; 1518 default: return "unknown thread state"; 1519 } 1520 } 1521 1522 void JavaThread::print_thread_state_on(outputStream *st) const { 1523 st->print_cr(" JavaThread state: %s", _get_thread_state_name(_thread_state)); 1524 } 1525 1526 // Called by Threads::print() for VM_PrintThreads operation 1527 void JavaThread::print_on(outputStream *st, bool print_extended_info) const { 1528 st->print_raw("\""); 1529 st->print_raw(name()); 1530 st->print_raw("\" "); 1531 oop thread_oop = threadObj(); 1532 if (thread_oop != nullptr) { 1533 st->print("#" INT64_FORMAT " [%ld] ", (int64_t)java_lang_Thread::thread_id(thread_oop), (long) osthread()->thread_id()); 1534 if (java_lang_Thread::is_daemon(thread_oop)) st->print("daemon "); 1535 st->print("prio=%d ", java_lang_Thread::priority(thread_oop)); 1536 } 1537 Thread::print_on(st, print_extended_info); 1538 // print guess for valid stack memory region (assume 4K pages); helps lock debugging 1539 st->print_cr("[" INTPTR_FORMAT "]", (intptr_t)last_Java_sp() & ~right_n_bits(12)); 1540 if (thread_oop != nullptr) { 1541 if (is_vthread_mounted()) { 1542 // _lock_id is the thread ID of the mounted virtual thread 1543 st->print_cr(" Carrying virtual thread #" INT64_FORMAT, lock_id()); 1544 } else { 1545 st->print_cr(" java.lang.Thread.State: %s", java_lang_Thread::thread_status_name(thread_oop)); 1546 } 1547 } 1548 #ifndef PRODUCT 1549 _safepoint_state->print_on(st); 1550 #endif // PRODUCT 1551 if (is_Compiler_thread()) { 1552 CompileTask *task = ((CompilerThread*)this)->task(); 1553 if (task != nullptr) { 1554 st->print(" Compiling: "); 1555 task->print(st, nullptr, true, false); 1556 } else { 1557 st->print(" No compile task"); 1558 } 1559 st->cr(); 1560 } 1561 } 1562 1563 void JavaThread::print() const { print_on(tty); } 1564 1565 void JavaThread::print_name_on_error(outputStream* st, char *buf, int buflen) const { 1566 st->print("%s", get_thread_name_string(buf, buflen)); 1567 } 1568 1569 // Called by fatal error handler. The difference between this and 1570 // JavaThread::print() is that we can't grab lock or allocate memory. 1571 void JavaThread::print_on_error(outputStream* st, char *buf, int buflen) const { 1572 st->print("%s \"%s\"", type_name(), get_thread_name_string(buf, buflen)); 1573 Thread* current = Thread::current_or_null_safe(); 1574 assert(current != nullptr, "cannot be called by a detached thread"); 1575 st->fill_to(60); 1576 if (!current->is_Java_thread() || JavaThread::cast(current)->is_oop_safe()) { 1577 // Only access threadObj() if current thread is not a JavaThread 1578 // or if it is a JavaThread that can safely access oops. 1579 oop thread_obj = threadObj(); 1580 if (thread_obj != nullptr) { 1581 st->print(java_lang_Thread::is_daemon(thread_obj) ? " daemon" : " "); 1582 } 1583 } 1584 st->print(" ["); 1585 st->print("%s", _get_thread_state_name(_thread_state)); 1586 if (osthread()) { 1587 st->print(", id=%d", osthread()->thread_id()); 1588 } 1589 // Use raw field members for stack base/size as this could be 1590 // called before a thread has run enough to initialize them. 1591 st->print(", stack(" PTR_FORMAT "," PTR_FORMAT ") (" PROPERFMT ")", 1592 p2i(_stack_base - _stack_size), p2i(_stack_base), 1593 PROPERFMTARGS(_stack_size)); 1594 st->print("]"); 1595 1596 ThreadsSMRSupport::print_info_on(this, st); 1597 return; 1598 } 1599 1600 1601 // Verification 1602 1603 void JavaThread::frames_do(void f(frame*, const RegisterMap* map)) { 1604 // ignore if there is no stack 1605 if (!has_last_Java_frame()) return; 1606 // traverse the stack frames. Starts from top frame. 1607 for (StackFrameStream fst(this, true /* update_map */, true /* process_frames */, false /* walk_cont */); !fst.is_done(); fst.next()) { 1608 frame* fr = fst.current(); 1609 f(fr, fst.register_map()); 1610 } 1611 } 1612 1613 static void frame_verify(frame* f, const RegisterMap *map) { f->verify(map); } 1614 1615 void JavaThread::verify() { 1616 // Verify oops in the thread. 1617 oops_do(&VerifyOopClosure::verify_oop, nullptr); 1618 1619 // Verify the stack frames. 1620 frames_do(frame_verify); 1621 } 1622 1623 // CR 6300358 (sub-CR 2137150) 1624 // Most callers of this method assume that it can't return null but a 1625 // thread may not have a name whilst it is in the process of attaching to 1626 // the VM - see CR 6412693, and there are places where a JavaThread can be 1627 // seen prior to having its threadObj set (e.g., JNI attaching threads and 1628 // if vm exit occurs during initialization). These cases can all be accounted 1629 // for such that this method never returns null. 1630 const char* JavaThread::name() const { 1631 if (Thread::is_JavaThread_protected(/* target */ this)) { 1632 // The target JavaThread is protected so get_thread_name_string() is safe: 1633 return get_thread_name_string(); 1634 } 1635 1636 // The target JavaThread is not protected so we return the default: 1637 return Thread::name(); 1638 } 1639 1640 // Like name() but doesn't include the protection check. This must only be 1641 // called when it is known to be safe, even though the protection check can't tell 1642 // that e.g. when this thread is the init_thread() - see instanceKlass.cpp. 1643 const char* JavaThread::name_raw() const { 1644 return get_thread_name_string(); 1645 } 1646 1647 // Returns a non-null representation of this thread's name, or a suitable 1648 // descriptive string if there is no set name. 1649 const char* JavaThread::get_thread_name_string(char* buf, int buflen) const { 1650 const char* name_str; 1651 #ifdef ASSERT 1652 Thread* current = Thread::current_or_null_safe(); 1653 assert(current != nullptr, "cannot be called by a detached thread"); 1654 if (!current->is_Java_thread() || JavaThread::cast(current)->is_oop_safe()) { 1655 // Only access threadObj() if current thread is not a JavaThread 1656 // or if it is a JavaThread that can safely access oops. 1657 #endif 1658 oop thread_obj = threadObj(); 1659 if (thread_obj != nullptr) { 1660 oop name = java_lang_Thread::name(thread_obj); 1661 if (name != nullptr) { 1662 if (buf == nullptr) { 1663 name_str = java_lang_String::as_utf8_string(name); 1664 } else { 1665 name_str = java_lang_String::as_utf8_string(name, buf, buflen); 1666 } 1667 } else if (is_attaching_via_jni()) { // workaround for 6412693 - see 6404306 1668 name_str = "<no-name - thread is attaching>"; 1669 } else { 1670 name_str = "<un-named>"; 1671 } 1672 } else { 1673 name_str = Thread::name(); 1674 } 1675 #ifdef ASSERT 1676 } else { 1677 // Current JavaThread has exited... 1678 if (current == this) { 1679 // ... and is asking about itself: 1680 name_str = "<no-name - current JavaThread has exited>"; 1681 } else { 1682 // ... and it can't safely determine this JavaThread's name so 1683 // use the default thread name. 1684 name_str = Thread::name(); 1685 } 1686 } 1687 #endif 1688 assert(name_str != nullptr, "unexpected null thread name"); 1689 return name_str; 1690 } 1691 1692 // Helper to extract the name from the thread oop for logging. 1693 const char* JavaThread::name_for(oop thread_obj) { 1694 assert(thread_obj != nullptr, "precondition"); 1695 oop name = java_lang_Thread::name(thread_obj); 1696 const char* name_str; 1697 if (name != nullptr) { 1698 name_str = java_lang_String::as_utf8_string(name); 1699 } else { 1700 name_str = "<un-named>"; 1701 } 1702 return name_str; 1703 } 1704 1705 void JavaThread::prepare(jobject jni_thread, ThreadPriority prio) { 1706 1707 assert(Threads_lock->owner() == Thread::current(), "must have threads lock"); 1708 assert(NoPriority <= prio && prio <= MaxPriority, "sanity check"); 1709 // Link Java Thread object <-> C++ Thread 1710 1711 // Get the C++ thread object (an oop) from the JNI handle (a jthread) 1712 // and put it into a new Handle. The Handle "thread_oop" can then 1713 // be used to pass the C++ thread object to other methods. 1714 1715 // Set the Java level thread object (jthread) field of the 1716 // new thread (a JavaThread *) to C++ thread object using the 1717 // "thread_oop" handle. 1718 1719 // Set the thread field (a JavaThread *) of the 1720 // oop representing the java_lang_Thread to the new thread (a JavaThread *). 1721 1722 Handle thread_oop(Thread::current(), 1723 JNIHandles::resolve_non_null(jni_thread)); 1724 assert(InstanceKlass::cast(thread_oop->klass())->is_linked(), 1725 "must be initialized"); 1726 set_threadOopHandles(thread_oop()); 1727 set_lock_id(java_lang_Thread::thread_id(thread_oop())); 1728 1729 if (prio == NoPriority) { 1730 prio = java_lang_Thread::priority(thread_oop()); 1731 assert(prio != NoPriority, "A valid priority should be present"); 1732 } 1733 1734 // Push the Java priority down to the native thread; needs Threads_lock 1735 Thread::set_priority(this, prio); 1736 1737 // Add the new thread to the Threads list and set it in motion. 1738 // We must have threads lock in order to call Threads::add. 1739 // It is crucial that we do not block before the thread is 1740 // added to the Threads list for if a GC happens, then the java_thread oop 1741 // will not be visited by GC. 1742 Threads::add(this); 1743 // Publish the JavaThread* in java.lang.Thread after the JavaThread* is 1744 // on a ThreadsList. We don't want to wait for the release when the 1745 // Theads_lock is dropped somewhere in the caller since the JavaThread* 1746 // is already visible to JVM/TI via the ThreadsList. 1747 java_lang_Thread::release_set_thread(thread_oop(), this); 1748 } 1749 1750 oop JavaThread::current_park_blocker() { 1751 // Support for JSR-166 locks 1752 oop thread_oop = threadObj(); 1753 if (thread_oop != nullptr) { 1754 return java_lang_Thread::park_blocker(thread_oop); 1755 } 1756 return nullptr; 1757 } 1758 1759 // Print current stack trace for checked JNI warnings and JNI fatal errors. 1760 // This is the external format, selecting the platform or vthread 1761 // as applicable, and allowing for a native-only stack. 1762 void JavaThread::print_jni_stack() { 1763 assert(this == JavaThread::current(), "Can't print stack of other threads"); 1764 if (!has_last_Java_frame()) { 1765 ResourceMark rm(this); 1766 char* buf = NEW_RESOURCE_ARRAY_RETURN_NULL(char, O_BUFLEN); 1767 if (buf == nullptr) { 1768 tty->print_cr("Unable to print native stack - out of memory"); 1769 return; 1770 } 1771 address lastpc = nullptr; 1772 if (os::platform_print_native_stack(tty, nullptr, buf, O_BUFLEN, lastpc)) { 1773 // We have printed the native stack in platform-specific code, 1774 // so nothing else to do in this case. 1775 } else { 1776 frame f = os::current_frame(); 1777 VMError::print_native_stack(tty, f, this, true /*print_source_info */, 1778 -1 /* max stack */, buf, O_BUFLEN); 1779 } 1780 } else { 1781 print_active_stack_on(tty); 1782 } 1783 } 1784 1785 void JavaThread::print_stack_on(outputStream* st) { 1786 if (!has_last_Java_frame()) return; 1787 1788 Thread* current_thread = Thread::current(); 1789 ResourceMark rm(current_thread); 1790 HandleMark hm(current_thread); 1791 1792 RegisterMap reg_map(this, 1793 RegisterMap::UpdateMap::include, 1794 RegisterMap::ProcessFrames::include, 1795 RegisterMap::WalkContinuation::skip); 1796 vframe* start_vf = platform_thread_last_java_vframe(®_map); 1797 int count = 0; 1798 for (vframe* f = start_vf; f != nullptr; f = f->sender()) { 1799 if (f->is_java_frame()) { 1800 javaVFrame* jvf = javaVFrame::cast(f); 1801 java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci()); 1802 1803 // Print out lock information 1804 if (JavaMonitorsInStackTrace) { 1805 jvf->print_lock_info_on(st, count); 1806 } 1807 } else { 1808 // Ignore non-Java frames 1809 } 1810 1811 // Bail-out case for too deep stacks if MaxJavaStackTraceDepth > 0 1812 count++; 1813 if (MaxJavaStackTraceDepth > 0 && MaxJavaStackTraceDepth == count) return; 1814 } 1815 } 1816 1817 void JavaThread::print_vthread_stack_on(outputStream* st) { 1818 assert(is_vthread_mounted(), "Caller should have checked this"); 1819 assert(has_last_Java_frame(), "must be"); 1820 1821 Thread* current_thread = Thread::current(); 1822 ResourceMark rm(current_thread); 1823 HandleMark hm(current_thread); 1824 1825 RegisterMap reg_map(this, 1826 RegisterMap::UpdateMap::include, 1827 RegisterMap::ProcessFrames::include, 1828 RegisterMap::WalkContinuation::include); 1829 ContinuationEntry* cont_entry = last_continuation(); 1830 vframe* start_vf = last_java_vframe(®_map); 1831 int count = 0; 1832 for (vframe* f = start_vf; f != nullptr; f = f->sender()) { 1833 // Watch for end of vthread stack 1834 if (Continuation::is_continuation_enterSpecial(f->fr())) { 1835 assert(cont_entry == Continuation::get_continuation_entry_for_entry_frame(this, f->fr()), ""); 1836 if (cont_entry->is_virtual_thread()) { 1837 break; 1838 } 1839 cont_entry = cont_entry->parent(); 1840 } 1841 if (f->is_java_frame()) { 1842 javaVFrame* jvf = javaVFrame::cast(f); 1843 java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci()); 1844 1845 // Print out lock information 1846 if (JavaMonitorsInStackTrace) { 1847 jvf->print_lock_info_on(st, count); 1848 } 1849 } else { 1850 // Ignore non-Java frames 1851 } 1852 1853 // Bail-out case for too deep stacks if MaxJavaStackTraceDepth > 0 1854 count++; 1855 if (MaxJavaStackTraceDepth > 0 && MaxJavaStackTraceDepth == count) return; 1856 } 1857 } 1858 1859 void JavaThread::print_active_stack_on(outputStream* st) { 1860 if (is_vthread_mounted()) { 1861 print_vthread_stack_on(st); 1862 } else { 1863 print_stack_on(st); 1864 } 1865 } 1866 1867 #if INCLUDE_JVMTI 1868 // Rebind JVMTI thread state from carrier to virtual or from virtual to carrier. 1869 JvmtiThreadState* JavaThread::rebind_to_jvmti_thread_state_of(oop thread_oop) { 1870 set_jvmti_vthread(thread_oop); 1871 1872 // unbind current JvmtiThreadState from JavaThread 1873 JvmtiThreadState::unbind_from(jvmti_thread_state(), this); 1874 1875 // bind new JvmtiThreadState to JavaThread 1876 JvmtiThreadState::bind_to(java_lang_Thread::jvmti_thread_state(thread_oop), this); 1877 1878 // enable interp_only_mode for virtual or carrier thread if it has pending bit 1879 JvmtiThreadState::process_pending_interp_only(this); 1880 1881 return jvmti_thread_state(); 1882 } 1883 #endif 1884 1885 // JVMTI PopFrame support 1886 void JavaThread::popframe_preserve_args(ByteSize size_in_bytes, void* start) { 1887 assert(_popframe_preserved_args == nullptr, "should not wipe out old PopFrame preserved arguments"); 1888 if (in_bytes(size_in_bytes) != 0) { 1889 _popframe_preserved_args = NEW_C_HEAP_ARRAY(char, in_bytes(size_in_bytes), mtThread); 1890 _popframe_preserved_args_size = in_bytes(size_in_bytes); 1891 Copy::conjoint_jbytes(start, _popframe_preserved_args, _popframe_preserved_args_size); 1892 } 1893 } 1894 1895 void* JavaThread::popframe_preserved_args() { 1896 return _popframe_preserved_args; 1897 } 1898 1899 ByteSize JavaThread::popframe_preserved_args_size() { 1900 return in_ByteSize(_popframe_preserved_args_size); 1901 } 1902 1903 WordSize JavaThread::popframe_preserved_args_size_in_words() { 1904 int sz = in_bytes(popframe_preserved_args_size()); 1905 assert(sz % wordSize == 0, "argument size must be multiple of wordSize"); 1906 return in_WordSize(sz / wordSize); 1907 } 1908 1909 void JavaThread::popframe_free_preserved_args() { 1910 assert(_popframe_preserved_args != nullptr, "should not free PopFrame preserved arguments twice"); 1911 FREE_C_HEAP_ARRAY(char, (char*)_popframe_preserved_args); 1912 _popframe_preserved_args = nullptr; 1913 _popframe_preserved_args_size = 0; 1914 } 1915 1916 #ifndef PRODUCT 1917 1918 void JavaThread::trace_frames() { 1919 tty->print_cr("[Describe stack]"); 1920 int frame_no = 1; 1921 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) { 1922 tty->print(" %d. ", frame_no++); 1923 fst.current()->print_value_on(tty, this); 1924 tty->cr(); 1925 } 1926 } 1927 1928 class PrintAndVerifyOopClosure: public OopClosure { 1929 protected: 1930 template <class T> inline void do_oop_work(T* p) { 1931 oop obj = RawAccess<>::oop_load(p); 1932 if (obj == nullptr) return; 1933 tty->print(INTPTR_FORMAT ": ", p2i(p)); 1934 if (oopDesc::is_oop_or_null(obj)) { 1935 if (obj->is_objArray()) { 1936 tty->print_cr("valid objArray: " INTPTR_FORMAT, p2i(obj)); 1937 } else { 1938 obj->print(); 1939 } 1940 } else { 1941 tty->print_cr("invalid oop: " INTPTR_FORMAT, p2i(obj)); 1942 } 1943 tty->cr(); 1944 } 1945 public: 1946 virtual void do_oop(oop* p) { do_oop_work(p); } 1947 virtual void do_oop(narrowOop* p) { do_oop_work(p); } 1948 }; 1949 1950 #ifdef ASSERT 1951 // Print or validate the layout of stack frames 1952 void JavaThread::print_frame_layout(int depth, bool validate_only) { 1953 ResourceMark rm; 1954 PreserveExceptionMark pm(this); 1955 FrameValues values; 1956 int frame_no = 0; 1957 for (StackFrameStream fst(this, true, true, true); !fst.is_done(); fst.next()) { 1958 fst.current()->describe(values, ++frame_no, fst.register_map()); 1959 if (depth == frame_no) break; 1960 } 1961 Continuation::describe(values); 1962 if (validate_only) { 1963 values.validate(); 1964 } else { 1965 tty->print_cr("[Describe stack layout]"); 1966 values.print(this); 1967 } 1968 } 1969 #endif 1970 1971 void JavaThread::trace_stack_from(vframe* start_vf) { 1972 ResourceMark rm; 1973 int vframe_no = 1; 1974 for (vframe* f = start_vf; f; f = f->sender()) { 1975 if (f->is_java_frame()) { 1976 javaVFrame::cast(f)->print_activation(vframe_no++); 1977 } else { 1978 f->print(); 1979 } 1980 if (vframe_no > StackPrintLimit) { 1981 tty->print_cr("...<more frames>..."); 1982 return; 1983 } 1984 } 1985 } 1986 1987 1988 void JavaThread::trace_stack() { 1989 if (!has_last_Java_frame()) return; 1990 Thread* current_thread = Thread::current(); 1991 ResourceMark rm(current_thread); 1992 HandleMark hm(current_thread); 1993 RegisterMap reg_map(this, 1994 RegisterMap::UpdateMap::include, 1995 RegisterMap::ProcessFrames::include, 1996 RegisterMap::WalkContinuation::skip); 1997 trace_stack_from(last_java_vframe(®_map)); 1998 } 1999 2000 2001 #endif // PRODUCT 2002 2003 // Slow-path increment of the held monitor counts. JNI locking is always 2004 // this slow-path. 2005 void JavaThread::inc_held_monitor_count(intx i, bool jni) { 2006 #ifdef SUPPORT_MONITOR_COUNT 2007 assert(_held_monitor_count >= 0, "Must always be non-negative: " INTX_FORMAT, _held_monitor_count); 2008 _held_monitor_count += i; 2009 if (jni) { 2010 assert(_jni_monitor_count >= 0, "Must always be non-negative: " INTX_FORMAT, _jni_monitor_count); 2011 _jni_monitor_count += i; 2012 } 2013 assert(_held_monitor_count >= _jni_monitor_count, "Monitor count discrepancy detected - held count " 2014 INTX_FORMAT " is less than JNI count " INTX_FORMAT, _held_monitor_count, _jni_monitor_count); 2015 #endif 2016 } 2017 2018 // Slow-path decrement of the held monitor counts. JNI unlocking is always 2019 // this slow-path. 2020 void JavaThread::dec_held_monitor_count(intx i, bool jni) { 2021 #ifdef SUPPORT_MONITOR_COUNT 2022 _held_monitor_count -= i; 2023 assert(_held_monitor_count >= 0, "Must always be non-negative: " INTX_FORMAT, _held_monitor_count); 2024 if (jni) { 2025 _jni_monitor_count -= i; 2026 assert(_jni_monitor_count >= 0, "Must always be non-negative: " INTX_FORMAT, _jni_monitor_count); 2027 } 2028 // When a thread is detaching with still owned JNI monitors, the logic that releases 2029 // the monitors doesn't know to set the "jni" flag and so the counts can get out of sync. 2030 // So we skip this assert if the thread is exiting. Once all monitors are unlocked the 2031 // JNI count is directly set to zero. 2032 assert(_held_monitor_count >= _jni_monitor_count || is_exiting(), "Monitor count discrepancy detected - held count " 2033 INTX_FORMAT " is less than JNI count " INTX_FORMAT, _held_monitor_count, _jni_monitor_count); 2034 #endif 2035 } 2036 2037 frame JavaThread::vthread_last_frame() { 2038 assert (is_vthread_mounted(), "Virtual thread not mounted"); 2039 return last_frame(); 2040 } 2041 2042 frame JavaThread::carrier_last_frame(RegisterMap* reg_map) { 2043 const ContinuationEntry* entry = vthread_continuation(); 2044 guarantee (entry != nullptr, "Not a carrier thread"); 2045 frame f = entry->to_frame(); 2046 if (reg_map->process_frames()) { 2047 entry->flush_stack_processing(this); 2048 } 2049 entry->update_register_map(reg_map); 2050 return f.sender(reg_map); 2051 } 2052 2053 frame JavaThread::platform_thread_last_frame(RegisterMap* reg_map) { 2054 return is_vthread_mounted() ? carrier_last_frame(reg_map) : last_frame(); 2055 } 2056 2057 javaVFrame* JavaThread::last_java_vframe(const frame f, RegisterMap *reg_map) { 2058 assert(reg_map != nullptr, "a map must be given"); 2059 for (vframe* vf = vframe::new_vframe(&f, reg_map, this); vf; vf = vf->sender()) { 2060 if (vf->is_java_frame()) return javaVFrame::cast(vf); 2061 } 2062 return nullptr; 2063 } 2064 2065 Klass* JavaThread::security_get_caller_class(int depth) { 2066 ResetNoHandleMark rnhm; 2067 HandleMark hm(Thread::current()); 2068 2069 vframeStream vfst(this); 2070 vfst.security_get_caller_frame(depth); 2071 if (!vfst.at_end()) { 2072 return vfst.method()->method_holder(); 2073 } 2074 return nullptr; 2075 } 2076 2077 // Internal convenience function for millisecond resolution sleeps. 2078 bool JavaThread::sleep(jlong millis) { 2079 jlong nanos; 2080 if (millis > max_jlong / NANOUNITS_PER_MILLIUNIT) { 2081 // Conversion to nanos would overflow, saturate at max 2082 nanos = max_jlong; 2083 } else { 2084 nanos = millis * NANOUNITS_PER_MILLIUNIT; 2085 } 2086 return sleep_nanos(nanos); 2087 } 2088 2089 // java.lang.Thread.sleep support 2090 // Returns true if sleep time elapsed as expected, and false 2091 // if the thread was interrupted. 2092 bool JavaThread::sleep_nanos(jlong nanos) { 2093 assert(this == Thread::current(), "thread consistency check"); 2094 assert(nanos >= 0, "nanos are in range"); 2095 2096 ParkEvent * const slp = this->_SleepEvent; 2097 // Because there can be races with thread interruption sending an unpark() 2098 // to the event, we explicitly reset it here to avoid an immediate return. 2099 // The actual interrupt state will be checked before we park(). 2100 slp->reset(); 2101 // Thread interruption establishes a happens-before ordering in the 2102 // Java Memory Model, so we need to ensure we synchronize with the 2103 // interrupt state. 2104 OrderAccess::fence(); 2105 2106 jlong prevtime = os::javaTimeNanos(); 2107 2108 jlong nanos_remaining = nanos; 2109 2110 for (;;) { 2111 // interruption has precedence over timing out 2112 if (this->is_interrupted(true)) { 2113 return false; 2114 } 2115 2116 if (nanos_remaining <= 0) { 2117 return true; 2118 } 2119 2120 { 2121 ThreadBlockInVM tbivm(this); 2122 OSThreadWaitState osts(this->osthread(), false /* not Object.wait() */); 2123 slp->park_nanos(nanos_remaining); 2124 } 2125 2126 // Update elapsed time tracking 2127 jlong newtime = os::javaTimeNanos(); 2128 if (newtime - prevtime < 0) { 2129 // time moving backwards, should only happen if no monotonic clock 2130 // not a guarantee() because JVM should not abort on kernel/glibc bugs 2131 assert(false, 2132 "unexpected time moving backwards detected in JavaThread::sleep()"); 2133 } else { 2134 nanos_remaining -= (newtime - prevtime); 2135 } 2136 prevtime = newtime; 2137 } 2138 } 2139 2140 // Last thread running calls java.lang.Shutdown.shutdown() 2141 void JavaThread::invoke_shutdown_hooks() { 2142 HandleMark hm(this); 2143 2144 // We could get here with a pending exception, if so clear it now. 2145 if (this->has_pending_exception()) { 2146 this->clear_pending_exception(); 2147 } 2148 2149 EXCEPTION_MARK; 2150 Klass* shutdown_klass = 2151 SystemDictionary::resolve_or_null(vmSymbols::java_lang_Shutdown(), 2152 THREAD); 2153 if (shutdown_klass != nullptr) { 2154 // SystemDictionary::resolve_or_null will return null if there was 2155 // an exception. If we cannot load the Shutdown class, just don't 2156 // call Shutdown.shutdown() at all. This will mean the shutdown hooks 2157 // won't be run. Note that if a shutdown hook was registered, 2158 // the Shutdown class would have already been loaded 2159 // (Runtime.addShutdownHook will load it). 2160 JavaValue result(T_VOID); 2161 JavaCalls::call_static(&result, 2162 shutdown_klass, 2163 vmSymbols::shutdown_name(), 2164 vmSymbols::void_method_signature(), 2165 THREAD); 2166 } 2167 CLEAR_PENDING_EXCEPTION; 2168 } 2169 2170 #ifndef PRODUCT 2171 void JavaThread::verify_cross_modify_fence_failure(JavaThread *thread) { 2172 report_vm_error(__FILE__, __LINE__, "Cross modify fence failure", "%p", thread); 2173 } 2174 #endif 2175 2176 // Helper function to create the java.lang.Thread object for a 2177 // VM-internal thread. The thread will have the given name, and be 2178 // a member of the "system" ThreadGroup. 2179 Handle JavaThread::create_system_thread_object(const char* name, TRAPS) { 2180 Handle string = java_lang_String::create_from_str(name, CHECK_NH); 2181 2182 // Initialize thread_oop to put it into the system threadGroup. 2183 // This is done by calling the Thread(ThreadGroup group, String name) constructor. 2184 Handle thread_group(THREAD, Universe::system_thread_group()); 2185 Handle thread_oop = 2186 JavaCalls::construct_new_instance(vmClasses::Thread_klass(), 2187 vmSymbols::threadgroup_string_void_signature(), 2188 thread_group, 2189 string, 2190 CHECK_NH); 2191 2192 return thread_oop; 2193 } 2194 2195 // Starts the target JavaThread as a daemon of the given priority, and 2196 // bound to the given java.lang.Thread instance. 2197 // The Threads_lock is held for the duration. 2198 void JavaThread::start_internal_daemon(JavaThread* current, JavaThread* target, 2199 Handle thread_oop, ThreadPriority prio) { 2200 2201 assert(target->osthread() != nullptr, "target thread is not properly initialized"); 2202 2203 MutexLocker mu(current, Threads_lock); 2204 2205 // Initialize the fields of the thread_oop first. 2206 if (prio != NoPriority) { 2207 java_lang_Thread::set_priority(thread_oop(), prio); 2208 // Note: we don't call os::set_priority here. Possibly we should, 2209 // else all threads should call it themselves when they first run. 2210 } 2211 2212 java_lang_Thread::set_daemon(thread_oop()); 2213 2214 // Now bind the thread_oop to the target JavaThread. 2215 target->set_threadOopHandles(thread_oop()); 2216 target->set_lock_id(java_lang_Thread::thread_id(thread_oop())); 2217 2218 Threads::add(target); // target is now visible for safepoint/handshake 2219 // Publish the JavaThread* in java.lang.Thread after the JavaThread* is 2220 // on a ThreadsList. We don't want to wait for the release when the 2221 // Theads_lock is dropped when the 'mu' destructor is run since the 2222 // JavaThread* is already visible to JVM/TI via the ThreadsList. 2223 2224 assert(java_lang_Thread::thread(thread_oop()) == nullptr, "must not be alive"); 2225 java_lang_Thread::release_set_thread(thread_oop(), target); // isAlive == true now 2226 Thread::start(target); 2227 } 2228 2229 void JavaThread::vm_exit_on_osthread_failure(JavaThread* thread) { 2230 // At this point it may be possible that no osthread was created for the 2231 // JavaThread due to lack of resources. However, since this must work 2232 // for critical system threads just check and abort if this fails. 2233 if (thread->osthread() == nullptr) { 2234 // This isn't really an OOM condition, but historically this is what 2235 // we report. 2236 vm_exit_during_initialization("java.lang.OutOfMemoryError", 2237 os::native_thread_creation_failed_msg()); 2238 } 2239 } 2240 2241 void JavaThread::pretouch_stack() { 2242 // Given an established java thread stack with usable area followed by 2243 // shadow zone and reserved/yellow/red zone, pretouch the usable area ranging 2244 // from the current frame down to the start of the shadow zone. 2245 const address end = _stack_overflow_state.shadow_zone_safe_limit(); 2246 if (is_in_full_stack(end)) { 2247 char* p1 = (char*) alloca(1); 2248 address here = (address) &p1; 2249 if (is_in_full_stack(here) && here > end) { 2250 size_t to_alloc = here - end; 2251 char* p2 = (char*) alloca(to_alloc); 2252 log_trace(os, thread)("Pretouching thread stack for " UINTX_FORMAT ": " RANGEFMT ".", 2253 (uintx) osthread()->thread_id(), RANGEFMTARGS(p2, to_alloc)); 2254 os::pretouch_memory(p2, p2 + to_alloc, 2255 NOT_AIX(os::vm_page_size()) AIX_ONLY(4096)); 2256 } 2257 } 2258 } 2259 2260 // Deferred OopHandle release support. 2261 2262 class OopHandleList : public CHeapObj<mtInternal> { 2263 static const int _count = 4; 2264 OopHandle _handles[_count]; 2265 OopHandleList* _next; 2266 int _index; 2267 public: 2268 OopHandleList(OopHandleList* next) : _next(next), _index(0) {} 2269 void add(OopHandle h) { 2270 assert(_index < _count, "too many additions"); 2271 _handles[_index++] = h; 2272 } 2273 ~OopHandleList() { 2274 assert(_index == _count, "usage error"); 2275 for (int i = 0; i < _index; i++) { 2276 _handles[i].release(JavaThread::thread_oop_storage()); 2277 } 2278 } 2279 OopHandleList* next() const { return _next; } 2280 }; 2281 2282 OopHandleList* JavaThread::_oop_handle_list = nullptr; 2283 2284 // Called by the ServiceThread to do the work of releasing 2285 // the OopHandles. 2286 void JavaThread::release_oop_handles() { 2287 OopHandleList* list; 2288 { 2289 MutexLocker ml(Service_lock, Mutex::_no_safepoint_check_flag); 2290 list = _oop_handle_list; 2291 _oop_handle_list = nullptr; 2292 } 2293 assert(!SafepointSynchronize::is_at_safepoint(), "cannot be called at a safepoint"); 2294 2295 while (list != nullptr) { 2296 OopHandleList* l = list; 2297 list = l->next(); 2298 delete l; 2299 } 2300 } 2301 2302 // Add our OopHandles for later release. 2303 void JavaThread::add_oop_handles_for_release() { 2304 MutexLocker ml(Service_lock, Mutex::_no_safepoint_check_flag); 2305 OopHandleList* new_head = new OopHandleList(_oop_handle_list); 2306 new_head->add(_threadObj); 2307 new_head->add(_vthread); 2308 new_head->add(_jvmti_vthread); 2309 new_head->add(_scopedValueCache); 2310 _oop_handle_list = new_head; 2311 Service_lock->notify_all(); 2312 } --- EOF ---