1 /* 2 * Copyright (c) 1997, 2023, Oracle and/or its affiliates. All rights reserved. 3 * Copyright (c) 2021, Azul Systems, Inc. All rights reserved. 4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 5 * 6 * This code is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License version 2 only, as 8 * published by the Free Software Foundation. 9 * 10 * This code is distributed in the hope that it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 13 * version 2 for more details (a copy is included in the LICENSE file that 14 * accompanied this code). 15 * 16 * You should have received a copy of the GNU General Public License version 17 * 2 along with this work; if not, write to the Free Software Foundation, 18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 19 * 20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 21 * or visit www.oracle.com if you need additional information or have any 22 * questions. 23 * 24 */ 25 26 #include "precompiled.hpp" 27 #include "cds/dynamicArchive.hpp" 28 #include "ci/ciEnv.hpp" 29 #include "classfile/javaClasses.inline.hpp" 30 #include "classfile/javaThreadStatus.hpp" 31 #include "classfile/systemDictionary.hpp" 32 #include "classfile/vmClasses.hpp" 33 #include "classfile/vmSymbols.hpp" 34 #include "code/codeCache.hpp" 35 #include "code/scopeDesc.hpp" 36 #include "compiler/compileTask.hpp" 37 #include "compiler/compilerThread.hpp" 38 #include "gc/shared/oopStorage.hpp" 39 #include "gc/shared/oopStorageSet.hpp" 40 #include "gc/shared/tlab_globals.hpp" 41 #include "jfr/jfrEvents.hpp" 42 #include "jvm.h" 43 #include "jvmtifiles/jvmtiEnv.hpp" 44 #include "logging/log.hpp" 45 #include "logging/logAsyncWriter.hpp" 46 #include "logging/logStream.hpp" 47 #include "memory/allocation.inline.hpp" 48 #include "memory/iterator.hpp" 49 #include "memory/universe.hpp" 50 #include "oops/access.inline.hpp" 51 #include "oops/inlineKlass.hpp" 52 #include "oops/instanceKlass.hpp" 53 #include "oops/klass.inline.hpp" 54 #include "oops/oop.inline.hpp" 55 #include "oops/oopHandle.inline.hpp" 56 #include "oops/verifyOopClosure.hpp" 57 #include "prims/jvm_misc.hpp" 58 #include "prims/jvmtiDeferredUpdates.hpp" 59 #include "prims/jvmtiExport.hpp" 60 #include "prims/jvmtiThreadState.inline.hpp" 61 #include "runtime/atomic.hpp" 62 #include "runtime/continuation.hpp" 63 #include "runtime/continuationEntry.inline.hpp" 64 #include "runtime/continuationHelper.inline.hpp" 65 #include "runtime/deoptimization.hpp" 66 #include "runtime/frame.inline.hpp" 67 #include "runtime/handles.inline.hpp" 68 #include "runtime/handshake.hpp" 69 #include "runtime/interfaceSupport.inline.hpp" 70 #include "runtime/java.hpp" 71 #include "runtime/javaCalls.hpp" 72 #include "runtime/javaThread.inline.hpp" 73 #include "runtime/jniHandles.inline.hpp" 74 #include "runtime/mutexLocker.hpp" 75 #include "runtime/orderAccess.hpp" 76 #include "runtime/osThread.hpp" 77 #include "runtime/safepoint.hpp" 78 #include "runtime/safepointMechanism.inline.hpp" 79 #include "runtime/safepointVerifiers.hpp" 80 #include "runtime/serviceThread.hpp" 81 #include "runtime/stackFrameStream.inline.hpp" 82 #include "runtime/stackWatermarkSet.hpp" 83 #include "runtime/synchronizer.hpp" 84 #include "runtime/threadCritical.hpp" 85 #include "runtime/threadSMR.inline.hpp" 86 #include "runtime/threadStatisticalInfo.hpp" 87 #include "runtime/threadWXSetters.inline.hpp" 88 #include "runtime/timer.hpp" 89 #include "runtime/timerTrace.hpp" 90 #include "runtime/vframe.inline.hpp" 91 #include "runtime/vframeArray.hpp" 92 #include "runtime/vframe_hp.hpp" 93 #include "runtime/vmThread.hpp" 94 #include "runtime/vmOperations.hpp" 95 #include "services/threadService.hpp" 96 #include "utilities/copy.hpp" 97 #include "utilities/defaultStream.hpp" 98 #include "utilities/dtrace.hpp" 99 #include "utilities/events.hpp" 100 #include "utilities/macros.hpp" 101 #include "utilities/preserveException.hpp" 102 #include "utilities/spinYield.hpp" 103 #include "utilities/vmError.hpp" 104 #if INCLUDE_JVMCI 105 #include "jvmci/jvmci.hpp" 106 #include "jvmci/jvmciEnv.hpp" 107 #endif 108 #if INCLUDE_JFR 109 #include "jfr/jfr.hpp" 110 #endif 111 112 // Set by os layer. 113 size_t JavaThread::_stack_size_at_create = 0; 114 115 #ifdef DTRACE_ENABLED 116 117 // Only bother with this argument setup if dtrace is available 118 119 #define HOTSPOT_THREAD_PROBE_start HOTSPOT_THREAD_START 120 #define HOTSPOT_THREAD_PROBE_stop HOTSPOT_THREAD_STOP 121 122 #define DTRACE_THREAD_PROBE(probe, javathread) \ 123 { \ 124 ResourceMark rm(this); \ 125 int len = 0; \ 126 const char* name = (javathread)->name(); \ 127 len = strlen(name); \ 128 HOTSPOT_THREAD_PROBE_##probe(/* probe = start, stop */ \ 129 (char *) name, len, \ 130 java_lang_Thread::thread_id((javathread)->threadObj()), \ 131 (uintptr_t) (javathread)->osthread()->thread_id(), \ 132 java_lang_Thread::is_daemon((javathread)->threadObj())); \ 133 } 134 135 #else // ndef DTRACE_ENABLED 136 137 #define DTRACE_THREAD_PROBE(probe, javathread) 138 139 #endif // ndef DTRACE_ENABLED 140 141 void JavaThread::smr_delete() { 142 if (_on_thread_list) { 143 ThreadsSMRSupport::smr_delete(this); 144 } else { 145 delete this; 146 } 147 } 148 149 // Initialized by VMThread at vm_global_init 150 OopStorage* JavaThread::_thread_oop_storage = nullptr; 151 152 OopStorage* JavaThread::thread_oop_storage() { 153 assert(_thread_oop_storage != nullptr, "not yet initialized"); 154 return _thread_oop_storage; 155 } 156 157 void JavaThread::set_threadOopHandles(oop p) { 158 assert(_thread_oop_storage != nullptr, "not yet initialized"); 159 _threadObj = OopHandle(_thread_oop_storage, p); 160 _vthread = OopHandle(_thread_oop_storage, p); 161 _jvmti_vthread = OopHandle(_thread_oop_storage, p->is_a(vmClasses::BoundVirtualThread_klass()) ? p : nullptr); 162 _scopedValueCache = OopHandle(_thread_oop_storage, nullptr); 163 } 164 165 oop JavaThread::threadObj() const { 166 // Ideally we would verify the current thread is oop_safe when this is called, but as we can 167 // be called from a signal handler we would have to use Thread::current_or_null_safe(). That 168 // has overhead and also interacts poorly with GetLastError on Windows due to the use of TLS. 169 // Instead callers must verify oop safe access. 170 return _threadObj.resolve(); 171 } 172 173 oop JavaThread::vthread() const { 174 return _vthread.resolve(); 175 } 176 177 void JavaThread::set_vthread(oop p) { 178 assert(_thread_oop_storage != nullptr, "not yet initialized"); 179 _vthread.replace(p); 180 } 181 182 oop JavaThread::jvmti_vthread() const { 183 return _jvmti_vthread.resolve(); 184 } 185 186 void JavaThread::set_jvmti_vthread(oop p) { 187 assert(_thread_oop_storage != nullptr, "not yet initialized"); 188 _jvmti_vthread.replace(p); 189 } 190 191 oop JavaThread::scopedValueCache() const { 192 return _scopedValueCache.resolve(); 193 } 194 195 void JavaThread::set_scopedValueCache(oop p) { 196 if (_scopedValueCache.ptr_raw() != nullptr) { // i.e. if the OopHandle has been allocated 197 _scopedValueCache.replace(p); 198 } else { 199 assert(p == nullptr, "not yet initialized"); 200 } 201 } 202 203 void JavaThread::clear_scopedValueBindings() { 204 set_scopedValueCache(nullptr); 205 oop vthread_oop = vthread(); 206 // vthread may be null here if we get a VM error during startup, 207 // before the java.lang.Thread instance has been created. 208 if (vthread_oop != nullptr) { 209 java_lang_Thread::clear_scopedValueBindings(vthread_oop); 210 } 211 } 212 213 void JavaThread::allocate_threadObj(Handle thread_group, const char* thread_name, 214 bool daemon, TRAPS) { 215 assert(thread_group.not_null(), "thread group should be specified"); 216 assert(threadObj() == nullptr, "should only create Java thread object once"); 217 218 InstanceKlass* ik = vmClasses::Thread_klass(); 219 assert(ik->is_initialized(), "must be"); 220 instanceHandle thread_oop = ik->allocate_instance_handle(CHECK); 221 222 // We are called from jni_AttachCurrentThread/jni_AttachCurrentThreadAsDaemon. 223 // We cannot use JavaCalls::construct_new_instance because the java.lang.Thread 224 // constructor calls Thread.current(), which must be set here. 225 java_lang_Thread::set_thread(thread_oop(), this); 226 set_threadOopHandles(thread_oop()); 227 228 JavaValue result(T_VOID); 229 if (thread_name != nullptr) { 230 Handle name = java_lang_String::create_from_str(thread_name, CHECK); 231 // Thread gets assigned specified name and null target 232 JavaCalls::call_special(&result, 233 thread_oop, 234 ik, 235 vmSymbols::object_initializer_name(), 236 vmSymbols::threadgroup_string_void_signature(), 237 thread_group, 238 name, 239 CHECK); 240 } else { 241 // Thread gets assigned name "Thread-nnn" and null target 242 // (java.lang.Thread doesn't have a constructor taking only a ThreadGroup argument) 243 JavaCalls::call_special(&result, 244 thread_oop, 245 ik, 246 vmSymbols::object_initializer_name(), 247 vmSymbols::threadgroup_runnable_void_signature(), 248 thread_group, 249 Handle(), 250 CHECK); 251 } 252 os::set_priority(this, NormPriority); 253 254 if (daemon) { 255 java_lang_Thread::set_daemon(thread_oop()); 256 } 257 } 258 259 // ======= JavaThread ======== 260 261 #if INCLUDE_JVMCI 262 263 jlong* JavaThread::_jvmci_old_thread_counters; 264 265 bool jvmci_counters_include(JavaThread* thread) { 266 return !JVMCICountersExcludeCompiler || !thread->is_Compiler_thread(); 267 } 268 269 void JavaThread::collect_counters(jlong* array, int length) { 270 assert(length == JVMCICounterSize, "wrong value"); 271 for (int i = 0; i < length; i++) { 272 array[i] = _jvmci_old_thread_counters[i]; 273 } 274 for (JavaThread* tp : ThreadsListHandle()) { 275 if (jvmci_counters_include(tp)) { 276 for (int i = 0; i < length; i++) { 277 array[i] += tp->_jvmci_counters[i]; 278 } 279 } 280 } 281 } 282 283 // Attempt to enlarge the array for per thread counters. 284 jlong* resize_counters_array(jlong* old_counters, int current_size, int new_size) { 285 jlong* new_counters = NEW_C_HEAP_ARRAY_RETURN_NULL(jlong, new_size, mtJVMCI); 286 if (new_counters == nullptr) { 287 return nullptr; 288 } 289 if (old_counters == nullptr) { 290 old_counters = new_counters; 291 memset(old_counters, 0, sizeof(jlong) * new_size); 292 } else { 293 for (int i = 0; i < MIN2((int) current_size, new_size); i++) { 294 new_counters[i] = old_counters[i]; 295 } 296 if (new_size > current_size) { 297 memset(new_counters + current_size, 0, sizeof(jlong) * (new_size - current_size)); 298 } 299 FREE_C_HEAP_ARRAY(jlong, old_counters); 300 } 301 return new_counters; 302 } 303 304 // Attempt to enlarge the array for per thread counters. 305 bool JavaThread::resize_counters(int current_size, int new_size) { 306 jlong* new_counters = resize_counters_array(_jvmci_counters, current_size, new_size); 307 if (new_counters == nullptr) { 308 return false; 309 } else { 310 _jvmci_counters = new_counters; 311 return true; 312 } 313 } 314 315 class VM_JVMCIResizeCounters : public VM_Operation { 316 private: 317 int _new_size; 318 bool _failed; 319 320 public: 321 VM_JVMCIResizeCounters(int new_size) : _new_size(new_size), _failed(false) { } 322 VMOp_Type type() const { return VMOp_JVMCIResizeCounters; } 323 bool allow_nested_vm_operations() const { return true; } 324 void doit() { 325 // Resize the old thread counters array 326 jlong* new_counters = resize_counters_array(JavaThread::_jvmci_old_thread_counters, JVMCICounterSize, _new_size); 327 if (new_counters == nullptr) { 328 _failed = true; 329 return; 330 } else { 331 JavaThread::_jvmci_old_thread_counters = new_counters; 332 } 333 334 // Now resize each threads array 335 for (JavaThread* tp : ThreadsListHandle()) { 336 if (!tp->resize_counters(JVMCICounterSize, _new_size)) { 337 _failed = true; 338 break; 339 } 340 } 341 if (!_failed) { 342 JVMCICounterSize = _new_size; 343 } 344 } 345 346 bool failed() { return _failed; } 347 }; 348 349 bool JavaThread::resize_all_jvmci_counters(int new_size) { 350 VM_JVMCIResizeCounters op(new_size); 351 VMThread::execute(&op); 352 return !op.failed(); 353 } 354 355 #endif // INCLUDE_JVMCI 356 357 #ifdef ASSERT 358 // Checks safepoint allowed and clears unhandled oops at potential safepoints. 359 void JavaThread::check_possible_safepoint() { 360 if (_no_safepoint_count > 0) { 361 print_owned_locks(); 362 assert(false, "Possible safepoint reached by thread that does not allow it"); 363 } 364 #ifdef CHECK_UNHANDLED_OOPS 365 // Clear unhandled oops in JavaThreads so we get a crash right away. 366 clear_unhandled_oops(); 367 #endif // CHECK_UNHANDLED_OOPS 368 369 // Macos/aarch64 should be in the right state for safepoint (e.g. 370 // deoptimization needs WXWrite). Crashes caused by the wrong state rarely 371 // happens in practice, making such issues hard to find and reproduce. 372 #if defined(__APPLE__) && defined(AARCH64) 373 if (AssertWXAtThreadSync) { 374 assert_wx_state(WXWrite); 375 } 376 #endif 377 } 378 379 void JavaThread::check_for_valid_safepoint_state() { 380 // Don't complain if running a debugging command. 381 if (DebuggingContext::is_enabled()) return; 382 383 // Check NoSafepointVerifier, which is implied by locks taken that can be 384 // shared with the VM thread. This makes sure that no locks with allow_vm_block 385 // are held. 386 check_possible_safepoint(); 387 388 if (thread_state() != _thread_in_vm) { 389 fatal("LEAF method calling lock?"); 390 } 391 392 if (GCALotAtAllSafepoints) { 393 // We could enter a safepoint here and thus have a gc 394 InterfaceSupport::check_gc_alot(); 395 } 396 } 397 #endif // ASSERT 398 399 // A JavaThread is a normal Java thread 400 401 JavaThread::JavaThread() : 402 // Initialize fields 403 404 _on_thread_list(false), 405 DEBUG_ONLY(_java_call_counter(0) COMMA) 406 _entry_point(nullptr), 407 _deopt_mark(nullptr), 408 _deopt_nmethod(nullptr), 409 _vframe_array_head(nullptr), 410 _vframe_array_last(nullptr), 411 _jvmti_deferred_updates(nullptr), 412 _callee_target(nullptr), 413 _vm_result(nullptr), 414 _vm_result_2(nullptr), 415 416 _current_pending_monitor(nullptr), 417 _current_pending_monitor_is_from_java(true), 418 _current_waiting_monitor(nullptr), 419 _active_handles(nullptr), 420 _free_handle_block(nullptr), 421 _Stalled(0), 422 423 _monitor_chunks(nullptr), 424 425 _suspend_flags(0), 426 427 _thread_state(_thread_new), 428 _saved_exception_pc(nullptr), 429 #ifdef ASSERT 430 _no_safepoint_count(0), 431 _visited_for_critical_count(false), 432 #endif 433 434 _terminated(_not_terminated), 435 _in_deopt_handler(0), 436 _doing_unsafe_access(false), 437 _do_not_unlock_if_synchronized(false), 438 #if INCLUDE_JVMTI 439 _carrier_thread_suspended(false), 440 _is_in_VTMS_transition(false), 441 _is_in_tmp_VTMS_transition(false), 442 #ifdef ASSERT 443 _is_VTMS_transition_disabler(false), 444 #endif 445 #endif 446 _jni_attach_state(_not_attaching_via_jni), 447 #if INCLUDE_JVMCI 448 _pending_deoptimization(-1), 449 _pending_monitorenter(false), 450 _pending_transfer_to_interpreter(false), 451 _in_retryable_allocation(false), 452 _pending_failed_speculation(0), 453 _jvmci{nullptr}, 454 _libjvmci_runtime(nullptr), 455 _jvmci_counters(nullptr), 456 _jvmci_reserved0(0), 457 _jvmci_reserved1(0), 458 _jvmci_reserved_oop0(nullptr), 459 #endif // INCLUDE_JVMCI 460 461 _exception_oop(oop()), 462 _exception_pc(0), 463 _exception_handler_pc(0), 464 _is_method_handle_return(0), 465 466 _jni_active_critical(0), 467 _pending_jni_exception_check_fn(nullptr), 468 _depth_first_number(0), 469 470 // JVMTI PopFrame support 471 _popframe_condition(popframe_inactive), 472 _frames_to_pop_failed_realloc(0), 473 474 _cont_entry(nullptr), 475 _cont_fastpath(0), 476 _cont_fastpath_thread_state(1), 477 _held_monitor_count(0), 478 _jni_monitor_count(0), 479 480 _handshake(this), 481 482 _popframe_preserved_args(nullptr), 483 _popframe_preserved_args_size(0), 484 485 _jvmti_thread_state(nullptr), 486 _interp_only_mode(0), 487 _should_post_on_exceptions_flag(JNI_FALSE), 488 _thread_stat(new ThreadStatistics()), 489 490 _parker(), 491 492 _class_to_be_initialized(nullptr), 493 494 _SleepEvent(ParkEvent::Allocate(this)) 495 { 496 set_jni_functions(jni_functions()); 497 498 #if INCLUDE_JVMCI 499 assert(_jvmci._implicit_exception_pc == nullptr, "must be"); 500 if (JVMCICounterSize > 0) { 501 resize_counters(0, (int) JVMCICounterSize); 502 } 503 #endif // INCLUDE_JVMCI 504 505 // Setup safepoint state info for this thread 506 ThreadSafepointState::create(this); 507 508 SafepointMechanism::initialize_header(this); 509 510 set_requires_cross_modify_fence(false); 511 512 pd_initialize(); 513 assert(deferred_card_mark().is_empty(), "Default MemRegion ctor"); 514 } 515 516 JavaThread::JavaThread(bool is_attaching_via_jni) : JavaThread() { 517 if (is_attaching_via_jni) { 518 _jni_attach_state = _attaching_via_jni; 519 } 520 } 521 522 523 // interrupt support 524 525 void JavaThread::interrupt() { 526 // All callers should have 'this' thread protected by a 527 // ThreadsListHandle so that it cannot terminate and deallocate 528 // itself. 529 debug_only(check_for_dangling_thread_pointer(this);) 530 531 // For Windows _interrupt_event 532 WINDOWS_ONLY(osthread()->set_interrupted(true);) 533 534 // For Thread.sleep 535 _SleepEvent->unpark(); 536 537 // For JSR166 LockSupport.park 538 parker()->unpark(); 539 540 // For ObjectMonitor and JvmtiRawMonitor 541 _ParkEvent->unpark(); 542 } 543 544 545 bool JavaThread::is_interrupted(bool clear_interrupted) { 546 debug_only(check_for_dangling_thread_pointer(this);) 547 548 if (_threadObj.peek() == nullptr) { 549 // If there is no j.l.Thread then it is impossible to have 550 // been interrupted. We can find null during VM initialization 551 // or when a JNI thread is still in the process of attaching. 552 // In such cases this must be the current thread. 553 assert(this == Thread::current(), "invariant"); 554 return false; 555 } 556 557 bool interrupted = java_lang_Thread::interrupted(threadObj()); 558 559 // NOTE that since there is no "lock" around the interrupt and 560 // is_interrupted operations, there is the possibility that the 561 // interrupted flag will be "false" but that the 562 // low-level events will be in the signaled state. This is 563 // intentional. The effect of this is that Object.wait() and 564 // LockSupport.park() will appear to have a spurious wakeup, which 565 // is allowed and not harmful, and the possibility is so rare that 566 // it is not worth the added complexity to add yet another lock. 567 // For the sleep event an explicit reset is performed on entry 568 // to JavaThread::sleep, so there is no early return. It has also been 569 // recommended not to put the interrupted flag into the "event" 570 // structure because it hides the issue. 571 // Also, because there is no lock, we must only clear the interrupt 572 // state if we are going to report that we were interrupted; otherwise 573 // an interrupt that happens just after we read the field would be lost. 574 if (interrupted && clear_interrupted) { 575 assert(this == Thread::current(), "only the current thread can clear"); 576 java_lang_Thread::set_interrupted(threadObj(), false); 577 WINDOWS_ONLY(osthread()->set_interrupted(false);) 578 } 579 580 return interrupted; 581 } 582 583 void JavaThread::block_if_vm_exited() { 584 if (_terminated == _vm_exited) { 585 // _vm_exited is set at safepoint, and Threads_lock is never released 586 // so we will block here forever. 587 // Here we can be doing a jump from a safe state to an unsafe state without 588 // proper transition, but it happens after the final safepoint has begun so 589 // this jump won't cause any safepoint problems. 590 set_thread_state(_thread_in_vm); 591 Threads_lock->lock(); 592 ShouldNotReachHere(); 593 } 594 } 595 596 JavaThread::JavaThread(ThreadFunction entry_point, size_t stack_sz) : JavaThread() { 597 _jni_attach_state = _not_attaching_via_jni; 598 set_entry_point(entry_point); 599 // Create the native thread itself. 600 // %note runtime_23 601 os::ThreadType thr_type = os::java_thread; 602 thr_type = entry_point == &CompilerThread::thread_entry ? os::compiler_thread : 603 os::java_thread; 604 os::create_thread(this, thr_type, stack_sz); 605 // The _osthread may be null here because we ran out of memory (too many threads active). 606 // We need to throw and OutOfMemoryError - however we cannot do this here because the caller 607 // may hold a lock and all locks must be unlocked before throwing the exception (throwing 608 // the exception consists of creating the exception object & initializing it, initialization 609 // will leave the VM via a JavaCall and then all locks must be unlocked). 610 // 611 // The thread is still suspended when we reach here. Thread must be explicit started 612 // by creator! Furthermore, the thread must also explicitly be added to the Threads list 613 // by calling Threads:add. The reason why this is not done here, is because the thread 614 // object must be fully initialized (take a look at JVM_Start) 615 } 616 617 JavaThread::~JavaThread() { 618 619 // Enqueue OopHandles for release by the service thread. 620 add_oop_handles_for_release(); 621 622 // Return the sleep event to the free list 623 ParkEvent::Release(_SleepEvent); 624 _SleepEvent = nullptr; 625 626 // Free any remaining previous UnrollBlock 627 vframeArray* old_array = vframe_array_last(); 628 629 if (old_array != nullptr) { 630 Deoptimization::UnrollBlock* old_info = old_array->unroll_block(); 631 old_array->set_unroll_block(nullptr); 632 delete old_info; 633 delete old_array; 634 } 635 636 JvmtiDeferredUpdates* updates = deferred_updates(); 637 if (updates != nullptr) { 638 // This can only happen if thread is destroyed before deoptimization occurs. 639 assert(updates->count() > 0, "Updates holder not deleted"); 640 // free deferred updates. 641 delete updates; 642 set_deferred_updates(nullptr); 643 } 644 645 // All Java related clean up happens in exit 646 ThreadSafepointState::destroy(this); 647 if (_thread_stat != nullptr) delete _thread_stat; 648 649 #if INCLUDE_JVMCI 650 if (JVMCICounterSize > 0) { 651 FREE_C_HEAP_ARRAY(jlong, _jvmci_counters); 652 } 653 #endif // INCLUDE_JVMCI 654 } 655 656 657 // First JavaThread specific code executed by a new Java thread. 658 void JavaThread::pre_run() { 659 // empty - see comments in run() 660 } 661 662 // The main routine called by a new Java thread. This isn't overridden 663 // by subclasses, instead different subclasses define a different "entry_point" 664 // which defines the actual logic for that kind of thread. 665 void JavaThread::run() { 666 // initialize thread-local alloc buffer related fields 667 initialize_tlab(); 668 669 _stack_overflow_state.create_stack_guard_pages(); 670 671 cache_global_variables(); 672 673 // Thread is now sufficiently initialized to be handled by the safepoint code as being 674 // in the VM. Change thread state from _thread_new to _thread_in_vm 675 assert(this->thread_state() == _thread_new, "wrong thread state"); 676 set_thread_state(_thread_in_vm); 677 678 // Before a thread is on the threads list it is always safe, so after leaving the 679 // _thread_new we should emit a instruction barrier. The distance to modified code 680 // from here is probably far enough, but this is consistent and safe. 681 OrderAccess::cross_modify_fence(); 682 683 assert(JavaThread::current() == this, "sanity check"); 684 assert(!Thread::current()->owns_locks(), "sanity check"); 685 686 DTRACE_THREAD_PROBE(start, this); 687 688 // This operation might block. We call that after all safepoint checks for a new thread has 689 // been completed. 690 set_active_handles(JNIHandleBlock::allocate_block()); 691 692 if (JvmtiExport::should_post_thread_life()) { 693 JvmtiExport::post_thread_start(this); 694 695 } 696 697 if (AlwaysPreTouchStacks) { 698 pretouch_stack(); 699 } 700 701 // We call another function to do the rest so we are sure that the stack addresses used 702 // from there will be lower than the stack base just computed. 703 thread_main_inner(); 704 } 705 706 void JavaThread::thread_main_inner() { 707 assert(JavaThread::current() == this, "sanity check"); 708 assert(_threadObj.peek() != nullptr, "just checking"); 709 710 // Execute thread entry point unless this thread has a pending exception. 711 // Note: Due to JVMTI StopThread we can have pending exceptions already! 712 if (!this->has_pending_exception()) { 713 { 714 ResourceMark rm(this); 715 this->set_native_thread_name(this->name()); 716 } 717 HandleMark hm(this); 718 this->entry_point()(this, this); 719 } 720 721 DTRACE_THREAD_PROBE(stop, this); 722 723 // Cleanup is handled in post_run() 724 } 725 726 // Shared teardown for all JavaThreads 727 void JavaThread::post_run() { 728 this->exit(false); 729 this->unregister_thread_stack_with_NMT(); 730 // Defer deletion to here to ensure 'this' is still referenceable in call_run 731 // for any shared tear-down. 732 this->smr_delete(); 733 } 734 735 static void ensure_join(JavaThread* thread) { 736 // We do not need to grab the Threads_lock, since we are operating on ourself. 737 Handle threadObj(thread, thread->threadObj()); 738 assert(threadObj.not_null(), "java thread object must exist"); 739 ObjectLocker lock(threadObj, thread); 740 // Thread is exiting. So set thread_status field in java.lang.Thread class to TERMINATED. 741 java_lang_Thread::set_thread_status(threadObj(), JavaThreadStatus::TERMINATED); 742 // Clear the native thread instance - this makes isAlive return false and allows the join() 743 // to complete once we've done the notify_all below. Needs a release() to obey Java Memory Model 744 // requirements. 745 OrderAccess::release(); 746 java_lang_Thread::set_thread(threadObj(), nullptr); 747 lock.notify_all(thread); 748 // Ignore pending exception, since we are exiting anyway 749 thread->clear_pending_exception(); 750 } 751 752 static bool is_daemon(oop threadObj) { 753 return (threadObj != nullptr && java_lang_Thread::is_daemon(threadObj)); 754 } 755 756 // For any new cleanup additions, please check to see if they need to be applied to 757 // cleanup_failed_attach_current_thread as well. 758 void JavaThread::exit(bool destroy_vm, ExitType exit_type) { 759 assert(this == JavaThread::current(), "thread consistency check"); 760 assert(!is_exiting(), "should not be exiting or terminated already"); 761 762 elapsedTimer _timer_exit_phase1; 763 elapsedTimer _timer_exit_phase2; 764 elapsedTimer _timer_exit_phase3; 765 elapsedTimer _timer_exit_phase4; 766 767 if (log_is_enabled(Debug, os, thread, timer)) { 768 _timer_exit_phase1.start(); 769 } 770 771 HandleMark hm(this); 772 Handle uncaught_exception(this, this->pending_exception()); 773 this->clear_pending_exception(); 774 Handle threadObj(this, this->threadObj()); 775 assert(threadObj.not_null(), "Java thread object should be created"); 776 777 if (!destroy_vm) { 778 if (uncaught_exception.not_null()) { 779 EXCEPTION_MARK; 780 // Call method Thread.dispatchUncaughtException(). 781 Klass* thread_klass = vmClasses::Thread_klass(); 782 JavaValue result(T_VOID); 783 JavaCalls::call_virtual(&result, 784 threadObj, thread_klass, 785 vmSymbols::dispatchUncaughtException_name(), 786 vmSymbols::throwable_void_signature(), 787 uncaught_exception, 788 THREAD); 789 if (HAS_PENDING_EXCEPTION) { 790 ResourceMark rm(this); 791 jio_fprintf(defaultStream::error_stream(), 792 "\nException: %s thrown from the UncaughtExceptionHandler" 793 " in thread \"%s\"\n", 794 pending_exception()->klass()->external_name(), 795 name()); 796 CLEAR_PENDING_EXCEPTION; 797 } 798 } 799 800 if (!is_Compiler_thread()) { 801 // We have finished executing user-defined Java code and now have to do the 802 // implementation specific clean-up by calling Thread.exit(). We prevent any 803 // asynchronous exceptions from being delivered while in Thread.exit() 804 // to ensure the clean-up is not corrupted. 805 NoAsyncExceptionDeliveryMark _no_async(this); 806 807 EXCEPTION_MARK; 808 JavaValue result(T_VOID); 809 Klass* thread_klass = vmClasses::Thread_klass(); 810 JavaCalls::call_virtual(&result, 811 threadObj, thread_klass, 812 vmSymbols::exit_method_name(), 813 vmSymbols::void_method_signature(), 814 THREAD); 815 CLEAR_PENDING_EXCEPTION; 816 } 817 818 // notify JVMTI 819 if (JvmtiExport::should_post_thread_life()) { 820 JvmtiExport::post_thread_end(this); 821 } 822 } else { 823 // before_exit() has already posted JVMTI THREAD_END events 824 } 825 826 // Cleanup any pending async exception now since we cannot access oops after 827 // BarrierSet::barrier_set()->on_thread_detach() has been executed. 828 if (has_async_exception_condition()) { 829 handshake_state()->clean_async_exception_operation(); 830 } 831 832 // The careful dance between thread suspension and exit is handled here. 833 // Since we are in thread_in_vm state and suspension is done with handshakes, 834 // we can just put in the exiting state and it will be correctly handled. 835 // Also, no more async exceptions will be added to the queue after this point. 836 set_terminated(_thread_exiting); 837 ThreadService::current_thread_exiting(this, is_daemon(threadObj())); 838 839 if (log_is_enabled(Debug, os, thread, timer)) { 840 _timer_exit_phase1.stop(); 841 _timer_exit_phase2.start(); 842 } 843 844 // Capture daemon status before the thread is marked as terminated. 845 bool daemon = is_daemon(threadObj()); 846 847 // Notify waiters on thread object. This has to be done after exit() is called 848 // on the thread (if the thread is the last thread in a daemon ThreadGroup the 849 // group should have the destroyed bit set before waiters are notified). 850 ensure_join(this); 851 assert(!this->has_pending_exception(), "ensure_join should have cleared"); 852 853 if (log_is_enabled(Debug, os, thread, timer)) { 854 _timer_exit_phase2.stop(); 855 _timer_exit_phase3.start(); 856 } 857 // 6282335 JNI DetachCurrentThread spec states that all Java monitors 858 // held by this thread must be released. The spec does not distinguish 859 // between JNI-acquired and regular Java monitors. We can only see 860 // regular Java monitors here if monitor enter-exit matching is broken. 861 // 862 // ensure_join() ignores IllegalThreadStateExceptions, and so does 863 // ObjectSynchronizer::release_monitors_owned_by_thread(). 864 if (exit_type == jni_detach) { 865 // Sanity check even though JNI DetachCurrentThread() would have 866 // returned JNI_ERR if there was a Java frame. JavaThread exit 867 // should be done executing Java code by the time we get here. 868 assert(!this->has_last_Java_frame(), 869 "should not have a Java frame when detaching or exiting"); 870 ObjectSynchronizer::release_monitors_owned_by_thread(this); 871 assert(!this->has_pending_exception(), "release_monitors should have cleared"); 872 } 873 874 // Since above code may not release JNI monitors and if someone forgot to do an 875 // JNI monitorexit, held count should be equal jni count. 876 // Consider scan all object monitor for this owner if JNI count > 0 (at least on detach). 877 assert(this->held_monitor_count() == this->jni_monitor_count(), 878 "held monitor count should be equal to jni: " INT64_FORMAT " != " INT64_FORMAT, 879 (int64_t)this->held_monitor_count(), (int64_t)this->jni_monitor_count()); 880 if (CheckJNICalls && this->jni_monitor_count() > 0) { 881 // We would like a fatal here, but due to we never checked this before there 882 // is a lot of tests which breaks, even with an error log. 883 log_debug(jni)("JavaThread %s (tid: " UINTX_FORMAT ") with Objects still locked by JNI MonitorEnter.", 884 exit_type == JavaThread::normal_exit ? "exiting" : "detaching", os::current_thread_id()); 885 } 886 887 // These things needs to be done while we are still a Java Thread. Make sure that thread 888 // is in a consistent state, in case GC happens 889 JFR_ONLY(Jfr::on_thread_exit(this);) 890 891 if (active_handles() != nullptr) { 892 JNIHandleBlock* block = active_handles(); 893 set_active_handles(nullptr); 894 JNIHandleBlock::release_block(block); 895 } 896 897 if (free_handle_block() != nullptr) { 898 JNIHandleBlock* block = free_handle_block(); 899 set_free_handle_block(nullptr); 900 JNIHandleBlock::release_block(block); 901 } 902 903 // These have to be removed while this is still a valid thread. 904 _stack_overflow_state.remove_stack_guard_pages(); 905 906 if (UseTLAB) { 907 tlab().retire(); 908 } 909 910 if (JvmtiEnv::environments_might_exist()) { 911 JvmtiExport::cleanup_thread(this); 912 } 913 914 // We need to cache the thread name for logging purposes below as once 915 // we have called on_thread_detach this thread must not access any oops. 916 char* thread_name = nullptr; 917 if (log_is_enabled(Debug, os, thread, timer)) { 918 ResourceMark rm(this); 919 thread_name = os::strdup(name()); 920 } 921 922 log_info(os, thread)("JavaThread %s (tid: " UINTX_FORMAT ").", 923 exit_type == JavaThread::normal_exit ? "exiting" : "detaching", 924 os::current_thread_id()); 925 926 if (log_is_enabled(Debug, os, thread, timer)) { 927 _timer_exit_phase3.stop(); 928 _timer_exit_phase4.start(); 929 } 930 931 #if INCLUDE_JVMCI 932 if (JVMCICounterSize > 0) { 933 if (jvmci_counters_include(this)) { 934 for (int i = 0; i < JVMCICounterSize; i++) { 935 _jvmci_old_thread_counters[i] += _jvmci_counters[i]; 936 } 937 } 938 } 939 #endif // INCLUDE_JVMCI 940 941 // Remove from list of active threads list, and notify VM thread if we are the last non-daemon thread. 942 // We call BarrierSet::barrier_set()->on_thread_detach() here so no touching of oops after this point. 943 Threads::remove(this, daemon); 944 945 if (log_is_enabled(Debug, os, thread, timer)) { 946 _timer_exit_phase4.stop(); 947 log_debug(os, thread, timer)("name='%s'" 948 ", exit-phase1=" JLONG_FORMAT 949 ", exit-phase2=" JLONG_FORMAT 950 ", exit-phase3=" JLONG_FORMAT 951 ", exit-phase4=" JLONG_FORMAT, 952 thread_name, 953 _timer_exit_phase1.milliseconds(), 954 _timer_exit_phase2.milliseconds(), 955 _timer_exit_phase3.milliseconds(), 956 _timer_exit_phase4.milliseconds()); 957 os::free(thread_name); 958 } 959 } 960 961 void JavaThread::cleanup_failed_attach_current_thread(bool is_daemon) { 962 if (active_handles() != nullptr) { 963 JNIHandleBlock* block = active_handles(); 964 set_active_handles(nullptr); 965 JNIHandleBlock::release_block(block); 966 } 967 968 if (free_handle_block() != nullptr) { 969 JNIHandleBlock* block = free_handle_block(); 970 set_free_handle_block(nullptr); 971 JNIHandleBlock::release_block(block); 972 } 973 974 // These have to be removed while this is still a valid thread. 975 _stack_overflow_state.remove_stack_guard_pages(); 976 977 if (UseTLAB) { 978 tlab().retire(); 979 } 980 981 Threads::remove(this, is_daemon); 982 this->smr_delete(); 983 } 984 985 JavaThread* JavaThread::active() { 986 Thread* thread = Thread::current(); 987 if (thread->is_Java_thread()) { 988 return JavaThread::cast(thread); 989 } else { 990 assert(thread->is_VM_thread(), "this must be a vm thread"); 991 VM_Operation* op = ((VMThread*) thread)->vm_operation(); 992 JavaThread *ret = op == nullptr ? nullptr : JavaThread::cast(op->calling_thread()); 993 return ret; 994 } 995 } 996 997 bool JavaThread::is_lock_owned(address adr) const { 998 if (Thread::is_lock_owned(adr)) return true; 999 1000 for (MonitorChunk* chunk = monitor_chunks(); chunk != nullptr; chunk = chunk->next()) { 1001 if (chunk->contains(adr)) return true; 1002 } 1003 1004 return false; 1005 } 1006 1007 oop JavaThread::exception_oop() const { 1008 return Atomic::load(&_exception_oop); 1009 } 1010 1011 void JavaThread::set_exception_oop(oop o) { 1012 Atomic::store(&_exception_oop, o); 1013 } 1014 1015 void JavaThread::add_monitor_chunk(MonitorChunk* chunk) { 1016 chunk->set_next(monitor_chunks()); 1017 set_monitor_chunks(chunk); 1018 } 1019 1020 void JavaThread::remove_monitor_chunk(MonitorChunk* chunk) { 1021 guarantee(monitor_chunks() != nullptr, "must be non empty"); 1022 if (monitor_chunks() == chunk) { 1023 set_monitor_chunks(chunk->next()); 1024 } else { 1025 MonitorChunk* prev = monitor_chunks(); 1026 while (prev->next() != chunk) prev = prev->next(); 1027 prev->set_next(chunk->next()); 1028 } 1029 } 1030 1031 void JavaThread::handle_special_runtime_exit_condition() { 1032 if (is_obj_deopt_suspend()) { 1033 frame_anchor()->make_walkable(); 1034 wait_for_object_deoptimization(); 1035 } 1036 JFR_ONLY(SUSPEND_THREAD_CONDITIONAL(this);) 1037 } 1038 1039 1040 // Asynchronous exceptions support 1041 // 1042 void JavaThread::handle_async_exception(oop java_throwable) { 1043 assert(java_throwable != nullptr, "should have an _async_exception to throw"); 1044 assert(!is_at_poll_safepoint(), "should have never called this method"); 1045 1046 if (has_last_Java_frame()) { 1047 frame f = last_frame(); 1048 if (f.is_runtime_frame()) { 1049 // If the topmost frame is a runtime stub, then we are calling into 1050 // OptoRuntime from compiled code. Some runtime stubs (new, monitor_exit..) 1051 // must deoptimize the caller before continuing, as the compiled exception 1052 // handler table may not be valid. 1053 RegisterMap reg_map(this, 1054 RegisterMap::UpdateMap::skip, 1055 RegisterMap::ProcessFrames::include, 1056 RegisterMap::WalkContinuation::skip); 1057 frame compiled_frame = f.sender(®_map); 1058 if (!StressCompiledExceptionHandlers && compiled_frame.can_be_deoptimized()) { 1059 Deoptimization::deoptimize(this, compiled_frame); 1060 } 1061 } 1062 } 1063 1064 // We cannot call Exceptions::_throw(...) here because we cannot block 1065 set_pending_exception(java_throwable, __FILE__, __LINE__); 1066 1067 clear_scopedValueBindings(); 1068 1069 LogTarget(Info, exceptions) lt; 1070 if (lt.is_enabled()) { 1071 ResourceMark rm; 1072 LogStream ls(lt); 1073 ls.print("Async. exception installed at runtime exit (" INTPTR_FORMAT ")", p2i(this)); 1074 if (has_last_Java_frame()) { 1075 frame f = last_frame(); 1076 ls.print(" (pc: " INTPTR_FORMAT " sp: " INTPTR_FORMAT " )", p2i(f.pc()), p2i(f.sp())); 1077 } 1078 ls.print_cr(" of type: %s", java_throwable->klass()->external_name()); 1079 } 1080 } 1081 1082 void JavaThread::install_async_exception(AsyncExceptionHandshake* aeh) { 1083 // Do not throw asynchronous exceptions against the compiler thread 1084 // or if the thread is already exiting. 1085 if (!can_call_java() || is_exiting()) { 1086 delete aeh; 1087 return; 1088 } 1089 1090 oop exception = aeh->exception(); 1091 Handshake::execute(aeh, this); // Install asynchronous handshake 1092 1093 ResourceMark rm; 1094 if (log_is_enabled(Info, exceptions)) { 1095 log_info(exceptions)("Pending Async. exception installed of type: %s", 1096 InstanceKlass::cast(exception->klass())->external_name()); 1097 } 1098 // for AbortVMOnException flag 1099 Exceptions::debug_check_abort(exception->klass()->external_name()); 1100 1101 // Interrupt thread so it will wake up from a potential wait()/sleep()/park() 1102 java_lang_Thread::set_interrupted(threadObj(), true); 1103 this->interrupt(); 1104 } 1105 1106 class InstallAsyncExceptionHandshake : public HandshakeClosure { 1107 AsyncExceptionHandshake* _aeh; 1108 public: 1109 InstallAsyncExceptionHandshake(AsyncExceptionHandshake* aeh) : 1110 HandshakeClosure("InstallAsyncException"), _aeh(aeh) {} 1111 ~InstallAsyncExceptionHandshake() { 1112 // If InstallAsyncExceptionHandshake was never executed we need to clean up _aeh. 1113 delete _aeh; 1114 } 1115 void do_thread(Thread* thr) { 1116 JavaThread* target = JavaThread::cast(thr); 1117 target->install_async_exception(_aeh); 1118 _aeh = nullptr; 1119 } 1120 }; 1121 1122 void JavaThread::send_async_exception(JavaThread* target, oop java_throwable) { 1123 OopHandle e(Universe::vm_global(), java_throwable); 1124 InstallAsyncExceptionHandshake iaeh(new AsyncExceptionHandshake(e)); 1125 Handshake::execute(&iaeh, target); 1126 } 1127 1128 #if INCLUDE_JVMTI 1129 void JavaThread::set_is_in_VTMS_transition(bool val) { 1130 _is_in_VTMS_transition = val; 1131 } 1132 1133 #ifdef ASSERT 1134 void JavaThread::set_is_VTMS_transition_disabler(bool val) { 1135 _is_VTMS_transition_disabler = val; 1136 } 1137 #endif 1138 #endif 1139 1140 // External suspension mechanism. 1141 // 1142 // Guarantees on return (for a valid target thread): 1143 // - Target thread will not execute any new bytecode. 1144 // - Target thread will not enter any new monitors. 1145 // 1146 bool JavaThread::java_suspend() { 1147 #if INCLUDE_JVMTI 1148 // Suspending a JavaThread in VTMS transition or disabling VTMS transitions can cause deadlocks. 1149 assert(!is_in_VTMS_transition(), "no suspend allowed in VTMS transition"); 1150 assert(!is_VTMS_transition_disabler(), "no suspend allowed for VTMS transition disablers"); 1151 #endif 1152 1153 guarantee(Thread::is_JavaThread_protected(/* target */ this), 1154 "target JavaThread is not protected in calling context."); 1155 return this->handshake_state()->suspend(); 1156 } 1157 1158 bool JavaThread::java_resume() { 1159 guarantee(Thread::is_JavaThread_protected_by_TLH(/* target */ this), 1160 "missing ThreadsListHandle in calling context."); 1161 return this->handshake_state()->resume(); 1162 } 1163 1164 // Wait for another thread to perform object reallocation and relocking on behalf of 1165 // this thread. The current thread is required to change to _thread_blocked in order 1166 // to be seen to be safepoint/handshake safe whilst suspended and only after becoming 1167 // handshake safe, the other thread can complete the handshake used to synchronize 1168 // with this thread and then perform the reallocation and relocking. 1169 // See EscapeBarrier::sync_and_suspend_*() 1170 1171 void JavaThread::wait_for_object_deoptimization() { 1172 assert(!has_last_Java_frame() || frame_anchor()->walkable(), "should have walkable stack"); 1173 assert(this == Thread::current(), "invariant"); 1174 1175 bool spin_wait = os::is_MP(); 1176 do { 1177 ThreadBlockInVM tbivm(this, true /* allow_suspend */); 1178 // Wait for object deoptimization if requested. 1179 if (spin_wait) { 1180 // A single deoptimization is typically very short. Microbenchmarks 1181 // showed 5% better performance when spinning. 1182 const uint spin_limit = 10 * SpinYield::default_spin_limit; 1183 SpinYield spin(spin_limit); 1184 for (uint i = 0; is_obj_deopt_suspend() && i < spin_limit; i++) { 1185 spin.wait(); 1186 } 1187 // Spin just once 1188 spin_wait = false; 1189 } else { 1190 MonitorLocker ml(this, EscapeBarrier_lock, Monitor::_no_safepoint_check_flag); 1191 if (is_obj_deopt_suspend()) { 1192 ml.wait(); 1193 } 1194 } 1195 // A handshake for obj. deoptimization suspend could have been processed so 1196 // we must check after processing. 1197 } while (is_obj_deopt_suspend()); 1198 } 1199 1200 #ifdef ASSERT 1201 // Verify the JavaThread has not yet been published in the Threads::list, and 1202 // hence doesn't need protection from concurrent access at this stage. 1203 void JavaThread::verify_not_published() { 1204 // Cannot create a ThreadsListHandle here and check !tlh.includes(this) 1205 // since an unpublished JavaThread doesn't participate in the 1206 // Thread-SMR protocol for keeping a ThreadsList alive. 1207 assert(!on_thread_list(), "JavaThread shouldn't have been published yet!"); 1208 } 1209 #endif 1210 1211 // Slow path when the native==>Java barriers detect a safepoint/handshake is 1212 // pending, when _suspend_flags is non-zero or when we need to process a stack 1213 // watermark. Also check for pending async exceptions (except unsafe access error). 1214 // Note only the native==>Java barriers can call this function when thread state 1215 // is _thread_in_native_trans. 1216 void JavaThread::check_special_condition_for_native_trans(JavaThread *thread) { 1217 assert(thread->thread_state() == _thread_in_native_trans, "wrong state"); 1218 assert(!thread->has_last_Java_frame() || thread->frame_anchor()->walkable(), "Unwalkable stack in native->Java transition"); 1219 1220 thread->set_thread_state(_thread_in_vm); 1221 1222 // Enable WXWrite: called directly from interpreter native wrapper. 1223 MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXWrite, thread)); 1224 1225 SafepointMechanism::process_if_requested_with_exit_check(thread, true /* check asyncs */); 1226 1227 // After returning from native, it could be that the stack frames are not 1228 // yet safe to use. We catch such situations in the subsequent stack watermark 1229 // barrier, which will trap unsafe stack frames. 1230 StackWatermarkSet::before_unwind(thread); 1231 } 1232 1233 #ifndef PRODUCT 1234 // Deoptimization 1235 // Function for testing deoptimization 1236 void JavaThread::deoptimize() { 1237 StackFrameStream fst(this, false /* update */, true /* process_frames */); 1238 bool deopt = false; // Dump stack only if a deopt actually happens. 1239 bool only_at = strlen(DeoptimizeOnlyAt) > 0; 1240 // Iterate over all frames in the thread and deoptimize 1241 for (; !fst.is_done(); fst.next()) { 1242 if (fst.current()->can_be_deoptimized()) { 1243 1244 if (only_at) { 1245 // Deoptimize only at particular bcis. DeoptimizeOnlyAt 1246 // consists of comma or carriage return separated numbers so 1247 // search for the current bci in that string. 1248 address pc = fst.current()->pc(); 1249 nmethod* nm = (nmethod*) fst.current()->cb(); 1250 ScopeDesc* sd = nm->scope_desc_at(pc); 1251 char buffer[8]; 1252 jio_snprintf(buffer, sizeof(buffer), "%d", sd->bci()); 1253 size_t len = strlen(buffer); 1254 const char * found = strstr(DeoptimizeOnlyAt, buffer); 1255 while (found != nullptr) { 1256 if ((found[len] == ',' || found[len] == '\n' || found[len] == '\0') && 1257 (found == DeoptimizeOnlyAt || found[-1] == ',' || found[-1] == '\n')) { 1258 // Check that the bci found is bracketed by terminators. 1259 break; 1260 } 1261 found = strstr(found + 1, buffer); 1262 } 1263 if (!found) { 1264 continue; 1265 } 1266 } 1267 1268 if (DebugDeoptimization && !deopt) { 1269 deopt = true; // One-time only print before deopt 1270 tty->print_cr("[BEFORE Deoptimization]"); 1271 trace_frames(); 1272 trace_stack(); 1273 } 1274 Deoptimization::deoptimize(this, *fst.current()); 1275 } 1276 } 1277 1278 if (DebugDeoptimization && deopt) { 1279 tty->print_cr("[AFTER Deoptimization]"); 1280 trace_frames(); 1281 } 1282 } 1283 1284 1285 // Make zombies 1286 void JavaThread::make_zombies() { 1287 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) { 1288 if (fst.current()->can_be_deoptimized()) { 1289 // it is a Java nmethod 1290 nmethod* nm = CodeCache::find_nmethod(fst.current()->pc()); 1291 nm->make_not_entrant(); 1292 } 1293 } 1294 } 1295 #endif // PRODUCT 1296 1297 1298 void JavaThread::deoptimize_marked_methods() { 1299 if (!has_last_Java_frame()) return; 1300 StackFrameStream fst(this, false /* update */, true /* process_frames */); 1301 for (; !fst.is_done(); fst.next()) { 1302 if (fst.current()->should_be_deoptimized()) { 1303 Deoptimization::deoptimize(this, *fst.current()); 1304 } 1305 } 1306 } 1307 1308 #ifdef ASSERT 1309 void JavaThread::verify_frame_info() { 1310 assert((!has_last_Java_frame() && java_call_counter() == 0) || 1311 (has_last_Java_frame() && java_call_counter() > 0), 1312 "unexpected frame info: has_last_frame=%s, java_call_counter=%d", 1313 has_last_Java_frame() ? "true" : "false", java_call_counter()); 1314 } 1315 #endif 1316 1317 // Push on a new block of JNI handles. 1318 void JavaThread::push_jni_handle_block() { 1319 // Allocate a new block for JNI handles. 1320 // Inlined code from jni_PushLocalFrame() 1321 JNIHandleBlock* old_handles = active_handles(); 1322 JNIHandleBlock* new_handles = JNIHandleBlock::allocate_block(this); 1323 assert(old_handles != nullptr && new_handles != nullptr, "should not be null"); 1324 new_handles->set_pop_frame_link(old_handles); // make sure java handles get gc'd. 1325 set_active_handles(new_handles); 1326 } 1327 1328 // Pop off the current block of JNI handles. 1329 void JavaThread::pop_jni_handle_block() { 1330 // Release our JNI handle block 1331 JNIHandleBlock* old_handles = active_handles(); 1332 JNIHandleBlock* new_handles = old_handles->pop_frame_link(); 1333 assert(new_handles != nullptr, "should never set active handles to null"); 1334 set_active_handles(new_handles); 1335 old_handles->set_pop_frame_link(nullptr); 1336 JNIHandleBlock::release_block(old_handles, this); 1337 } 1338 1339 void JavaThread::oops_do_no_frames(OopClosure* f, CodeBlobClosure* cf) { 1340 // Verify that the deferred card marks have been flushed. 1341 assert(deferred_card_mark().is_empty(), "Should be empty during GC"); 1342 1343 // Traverse the GCHandles 1344 Thread::oops_do_no_frames(f, cf); 1345 1346 if (active_handles() != nullptr) { 1347 active_handles()->oops_do(f); 1348 } 1349 1350 DEBUG_ONLY(verify_frame_info();) 1351 1352 if (has_last_Java_frame()) { 1353 // Traverse the monitor chunks 1354 for (MonitorChunk* chunk = monitor_chunks(); chunk != nullptr; chunk = chunk->next()) { 1355 chunk->oops_do(f); 1356 } 1357 } 1358 1359 assert(vframe_array_head() == nullptr, "deopt in progress at a safepoint!"); 1360 // If we have deferred set_locals there might be oops waiting to be 1361 // written 1362 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = JvmtiDeferredUpdates::deferred_locals(this); 1363 if (list != nullptr) { 1364 for (int i = 0; i < list->length(); i++) { 1365 list->at(i)->oops_do(f); 1366 } 1367 } 1368 1369 // Traverse instance variables at the end since the GC may be moving things 1370 // around using this function 1371 f->do_oop((oop*) &_vm_result); 1372 f->do_oop((oop*) &_exception_oop); 1373 #if INCLUDE_JVMCI 1374 f->do_oop((oop*) &_jvmci_reserved_oop0); 1375 #endif 1376 1377 if (jvmti_thread_state() != nullptr) { 1378 jvmti_thread_state()->oops_do(f, cf); 1379 } 1380 1381 // The continuation oops are really on the stack. But there is typically at most 1382 // one of those per thread, so we handle them here in the oops_do_no_frames part 1383 // so that we don't have to sprinkle as many stack watermark checks where these 1384 // oops are used. We just need to make sure the thread has started processing. 1385 ContinuationEntry* entry = _cont_entry; 1386 while (entry != nullptr) { 1387 f->do_oop((oop*)entry->cont_addr()); 1388 f->do_oop((oop*)entry->chunk_addr()); 1389 entry = entry->parent(); 1390 } 1391 } 1392 1393 void JavaThread::oops_do_frames(OopClosure* f, CodeBlobClosure* cf) { 1394 if (!has_last_Java_frame()) { 1395 return; 1396 } 1397 // Finish any pending lazy GC activity for the frames 1398 StackWatermarkSet::finish_processing(this, nullptr /* context */, StackWatermarkKind::gc); 1399 // Traverse the execution stack 1400 for (StackFrameStream fst(this, true /* update */, false /* process_frames */); !fst.is_done(); fst.next()) { 1401 fst.current()->oops_do(f, cf, fst.register_map()); 1402 } 1403 } 1404 1405 #ifdef ASSERT 1406 void JavaThread::verify_states_for_handshake() { 1407 // This checks that the thread has a correct frame state during a handshake. 1408 verify_frame_info(); 1409 } 1410 #endif 1411 1412 void JavaThread::nmethods_do(CodeBlobClosure* cf) { 1413 DEBUG_ONLY(verify_frame_info();) 1414 MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXWrite, Thread::current());) 1415 1416 if (has_last_Java_frame()) { 1417 // Traverse the execution stack 1418 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) { 1419 fst.current()->nmethods_do(cf); 1420 } 1421 } 1422 1423 if (jvmti_thread_state() != nullptr) { 1424 jvmti_thread_state()->nmethods_do(cf); 1425 } 1426 } 1427 1428 void JavaThread::metadata_do(MetadataClosure* f) { 1429 if (has_last_Java_frame()) { 1430 // Traverse the execution stack to call f() on the methods in the stack 1431 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) { 1432 fst.current()->metadata_do(f); 1433 } 1434 } else if (is_Compiler_thread()) { 1435 // need to walk ciMetadata in current compile tasks to keep alive. 1436 CompilerThread* ct = (CompilerThread*)this; 1437 if (ct->env() != nullptr) { 1438 ct->env()->metadata_do(f); 1439 } 1440 CompileTask* task = ct->task(); 1441 if (task != nullptr) { 1442 task->metadata_do(f); 1443 } 1444 } 1445 } 1446 1447 // Printing 1448 const char* _get_thread_state_name(JavaThreadState _thread_state) { 1449 switch (_thread_state) { 1450 case _thread_uninitialized: return "_thread_uninitialized"; 1451 case _thread_new: return "_thread_new"; 1452 case _thread_new_trans: return "_thread_new_trans"; 1453 case _thread_in_native: return "_thread_in_native"; 1454 case _thread_in_native_trans: return "_thread_in_native_trans"; 1455 case _thread_in_vm: return "_thread_in_vm"; 1456 case _thread_in_vm_trans: return "_thread_in_vm_trans"; 1457 case _thread_in_Java: return "_thread_in_Java"; 1458 case _thread_in_Java_trans: return "_thread_in_Java_trans"; 1459 case _thread_blocked: return "_thread_blocked"; 1460 case _thread_blocked_trans: return "_thread_blocked_trans"; 1461 default: return "unknown thread state"; 1462 } 1463 } 1464 1465 void JavaThread::print_thread_state_on(outputStream *st) const { 1466 st->print_cr(" JavaThread state: %s", _get_thread_state_name(_thread_state)); 1467 } 1468 1469 // Called by Threads::print() for VM_PrintThreads operation 1470 void JavaThread::print_on(outputStream *st, bool print_extended_info) const { 1471 st->print_raw("\""); 1472 st->print_raw(name()); 1473 st->print_raw("\" "); 1474 oop thread_oop = threadObj(); 1475 if (thread_oop != nullptr) { 1476 st->print("#" INT64_FORMAT " [%ld] ", (int64_t)java_lang_Thread::thread_id(thread_oop), (long) osthread()->thread_id()); 1477 if (java_lang_Thread::is_daemon(thread_oop)) st->print("daemon "); 1478 st->print("prio=%d ", java_lang_Thread::priority(thread_oop)); 1479 } 1480 Thread::print_on(st, print_extended_info); 1481 // print guess for valid stack memory region (assume 4K pages); helps lock debugging 1482 st->print_cr("[" INTPTR_FORMAT "]", (intptr_t)last_Java_sp() & ~right_n_bits(12)); 1483 if (thread_oop != nullptr) { 1484 if (is_vthread_mounted()) { 1485 oop vt = vthread(); 1486 assert(vt != nullptr, ""); 1487 st->print_cr(" Carrying virtual thread #" INT64_FORMAT, (int64_t)java_lang_Thread::thread_id(vt)); 1488 } else { 1489 st->print_cr(" java.lang.Thread.State: %s", java_lang_Thread::thread_status_name(thread_oop)); 1490 } 1491 } 1492 #ifndef PRODUCT 1493 _safepoint_state->print_on(st); 1494 #endif // PRODUCT 1495 if (is_Compiler_thread()) { 1496 CompileTask *task = ((CompilerThread*)this)->task(); 1497 if (task != nullptr) { 1498 st->print(" Compiling: "); 1499 task->print(st, nullptr, true, false); 1500 } else { 1501 st->print(" No compile task"); 1502 } 1503 st->cr(); 1504 } 1505 } 1506 1507 void JavaThread::print() const { print_on(tty); } 1508 1509 void JavaThread::print_name_on_error(outputStream* st, char *buf, int buflen) const { 1510 st->print("%s", get_thread_name_string(buf, buflen)); 1511 } 1512 1513 // Called by fatal error handler. The difference between this and 1514 // JavaThread::print() is that we can't grab lock or allocate memory. 1515 void JavaThread::print_on_error(outputStream* st, char *buf, int buflen) const { 1516 st->print("%s \"%s\"", type_name(), get_thread_name_string(buf, buflen)); 1517 Thread* current = Thread::current_or_null_safe(); 1518 assert(current != nullptr, "cannot be called by a detached thread"); 1519 if (!current->is_Java_thread() || JavaThread::cast(current)->is_oop_safe()) { 1520 // Only access threadObj() if current thread is not a JavaThread 1521 // or if it is a JavaThread that can safely access oops. 1522 oop thread_obj = threadObj(); 1523 if (thread_obj != nullptr) { 1524 if (java_lang_Thread::is_daemon(thread_obj)) st->print(" daemon"); 1525 } 1526 } 1527 st->print(" ["); 1528 st->print("%s", _get_thread_state_name(_thread_state)); 1529 if (osthread()) { 1530 st->print(", id=%d", osthread()->thread_id()); 1531 } 1532 st->print(", stack(" PTR_FORMAT "," PTR_FORMAT ")", 1533 p2i(stack_end()), p2i(stack_base())); 1534 st->print("]"); 1535 1536 ThreadsSMRSupport::print_info_on(this, st); 1537 return; 1538 } 1539 1540 1541 // Verification 1542 1543 void JavaThread::frames_do(void f(frame*, const RegisterMap* map)) { 1544 // ignore if there is no stack 1545 if (!has_last_Java_frame()) return; 1546 // traverse the stack frames. Starts from top frame. 1547 for (StackFrameStream fst(this, true /* update_map */, true /* process_frames */, false /* walk_cont */); !fst.is_done(); fst.next()) { 1548 frame* fr = fst.current(); 1549 f(fr, fst.register_map()); 1550 } 1551 } 1552 1553 static void frame_verify(frame* f, const RegisterMap *map) { f->verify(map); } 1554 1555 void JavaThread::verify() { 1556 // Verify oops in the thread. 1557 oops_do(&VerifyOopClosure::verify_oop, nullptr); 1558 1559 // Verify the stack frames. 1560 frames_do(frame_verify); 1561 } 1562 1563 // CR 6300358 (sub-CR 2137150) 1564 // Most callers of this method assume that it can't return null but a 1565 // thread may not have a name whilst it is in the process of attaching to 1566 // the VM - see CR 6412693, and there are places where a JavaThread can be 1567 // seen prior to having its threadObj set (e.g., JNI attaching threads and 1568 // if vm exit occurs during initialization). These cases can all be accounted 1569 // for such that this method never returns null. 1570 const char* JavaThread::name() const { 1571 if (Thread::is_JavaThread_protected(/* target */ this)) { 1572 // The target JavaThread is protected so get_thread_name_string() is safe: 1573 return get_thread_name_string(); 1574 } 1575 1576 // The target JavaThread is not protected so we return the default: 1577 return Thread::name(); 1578 } 1579 1580 // Returns a non-null representation of this thread's name, or a suitable 1581 // descriptive string if there is no set name. 1582 const char* JavaThread::get_thread_name_string(char* buf, int buflen) const { 1583 const char* name_str; 1584 #ifdef ASSERT 1585 Thread* current = Thread::current_or_null_safe(); 1586 assert(current != nullptr, "cannot be called by a detached thread"); 1587 if (!current->is_Java_thread() || JavaThread::cast(current)->is_oop_safe()) { 1588 // Only access threadObj() if current thread is not a JavaThread 1589 // or if it is a JavaThread that can safely access oops. 1590 #endif 1591 oop thread_obj = threadObj(); 1592 if (thread_obj != nullptr) { 1593 oop name = java_lang_Thread::name(thread_obj); 1594 if (name != nullptr) { 1595 if (buf == nullptr) { 1596 name_str = java_lang_String::as_utf8_string(name); 1597 } else { 1598 name_str = java_lang_String::as_utf8_string(name, buf, buflen); 1599 } 1600 } else if (is_attaching_via_jni()) { // workaround for 6412693 - see 6404306 1601 name_str = "<no-name - thread is attaching>"; 1602 } else { 1603 name_str = "<un-named>"; 1604 } 1605 } else { 1606 name_str = Thread::name(); 1607 } 1608 #ifdef ASSERT 1609 } else { 1610 // Current JavaThread has exited... 1611 if (current == this) { 1612 // ... and is asking about itself: 1613 name_str = "<no-name - current JavaThread has exited>"; 1614 } else { 1615 // ... and it can't safely determine this JavaThread's name so 1616 // use the default thread name. 1617 name_str = Thread::name(); 1618 } 1619 } 1620 #endif 1621 assert(name_str != nullptr, "unexpected null thread name"); 1622 return name_str; 1623 } 1624 1625 // Helper to extract the name from the thread oop for logging. 1626 const char* JavaThread::name_for(oop thread_obj) { 1627 assert(thread_obj != nullptr, "precondition"); 1628 oop name = java_lang_Thread::name(thread_obj); 1629 const char* name_str; 1630 if (name != nullptr) { 1631 name_str = java_lang_String::as_utf8_string(name); 1632 } else { 1633 name_str = "<un-named>"; 1634 } 1635 return name_str; 1636 } 1637 1638 void JavaThread::prepare(jobject jni_thread, ThreadPriority prio) { 1639 1640 assert(Threads_lock->owner() == Thread::current(), "must have threads lock"); 1641 assert(NoPriority <= prio && prio <= MaxPriority, "sanity check"); 1642 // Link Java Thread object <-> C++ Thread 1643 1644 // Get the C++ thread object (an oop) from the JNI handle (a jthread) 1645 // and put it into a new Handle. The Handle "thread_oop" can then 1646 // be used to pass the C++ thread object to other methods. 1647 1648 // Set the Java level thread object (jthread) field of the 1649 // new thread (a JavaThread *) to C++ thread object using the 1650 // "thread_oop" handle. 1651 1652 // Set the thread field (a JavaThread *) of the 1653 // oop representing the java_lang_Thread to the new thread (a JavaThread *). 1654 1655 Handle thread_oop(Thread::current(), 1656 JNIHandles::resolve_non_null(jni_thread)); 1657 assert(InstanceKlass::cast(thread_oop->klass())->is_linked(), 1658 "must be initialized"); 1659 set_threadOopHandles(thread_oop()); 1660 java_lang_Thread::set_thread(thread_oop(), this); 1661 1662 if (prio == NoPriority) { 1663 prio = java_lang_Thread::priority(thread_oop()); 1664 assert(prio != NoPriority, "A valid priority should be present"); 1665 } 1666 1667 // Push the Java priority down to the native thread; needs Threads_lock 1668 Thread::set_priority(this, prio); 1669 1670 // Add the new thread to the Threads list and set it in motion. 1671 // We must have threads lock in order to call Threads::add. 1672 // It is crucial that we do not block before the thread is 1673 // added to the Threads list for if a GC happens, then the java_thread oop 1674 // will not be visited by GC. 1675 Threads::add(this); 1676 } 1677 1678 oop JavaThread::current_park_blocker() { 1679 // Support for JSR-166 locks 1680 oop thread_oop = threadObj(); 1681 if (thread_oop != nullptr) { 1682 return java_lang_Thread::park_blocker(thread_oop); 1683 } 1684 return nullptr; 1685 } 1686 1687 // Print current stack trace for checked JNI warnings and JNI fatal errors. 1688 // This is the external format, selecting the platform or vthread 1689 // as applicable, and allowing for a native-only stack. 1690 void JavaThread::print_jni_stack() { 1691 assert(this == JavaThread::current(), "Can't print stack of other threads"); 1692 if (!has_last_Java_frame()) { 1693 ResourceMark rm(this); 1694 char* buf = NEW_RESOURCE_ARRAY_RETURN_NULL(char, O_BUFLEN); 1695 if (buf == nullptr) { 1696 tty->print_cr("Unable to print native stack - out of memory"); 1697 return; 1698 } 1699 frame f = os::current_frame(); 1700 VMError::print_native_stack(tty, f, this, true /*print_source_info */, 1701 -1 /* max stack */, buf, O_BUFLEN); 1702 } else { 1703 print_active_stack_on(tty); 1704 } 1705 } 1706 1707 void JavaThread::print_stack_on(outputStream* st) { 1708 if (!has_last_Java_frame()) return; 1709 1710 Thread* current_thread = Thread::current(); 1711 ResourceMark rm(current_thread); 1712 HandleMark hm(current_thread); 1713 1714 RegisterMap reg_map(this, 1715 RegisterMap::UpdateMap::include, 1716 RegisterMap::ProcessFrames::include, 1717 RegisterMap::WalkContinuation::skip); 1718 vframe* start_vf = platform_thread_last_java_vframe(®_map); 1719 int count = 0; 1720 for (vframe* f = start_vf; f != nullptr; f = f->sender()) { 1721 if (f->is_java_frame()) { 1722 javaVFrame* jvf = javaVFrame::cast(f); 1723 java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci()); 1724 1725 // Print out lock information 1726 if (JavaMonitorsInStackTrace) { 1727 jvf->print_lock_info_on(st, count); 1728 } 1729 } else { 1730 // Ignore non-Java frames 1731 } 1732 1733 // Bail-out case for too deep stacks if MaxJavaStackTraceDepth > 0 1734 count++; 1735 if (MaxJavaStackTraceDepth > 0 && MaxJavaStackTraceDepth == count) return; 1736 } 1737 } 1738 1739 void JavaThread::print_vthread_stack_on(outputStream* st) { 1740 assert(is_vthread_mounted(), "Caller should have checked this"); 1741 assert(has_last_Java_frame(), "must be"); 1742 1743 Thread* current_thread = Thread::current(); 1744 ResourceMark rm(current_thread); 1745 HandleMark hm(current_thread); 1746 1747 RegisterMap reg_map(this, 1748 RegisterMap::UpdateMap::include, 1749 RegisterMap::ProcessFrames::include, 1750 RegisterMap::WalkContinuation::include); 1751 ContinuationEntry* cont_entry = last_continuation(); 1752 vframe* start_vf = last_java_vframe(®_map); 1753 int count = 0; 1754 for (vframe* f = start_vf; f != nullptr; f = f->sender()) { 1755 // Watch for end of vthread stack 1756 if (Continuation::is_continuation_enterSpecial(f->fr())) { 1757 assert(cont_entry == Continuation::get_continuation_entry_for_entry_frame(this, f->fr()), ""); 1758 if (cont_entry->is_virtual_thread()) { 1759 break; 1760 } 1761 cont_entry = cont_entry->parent(); 1762 } 1763 if (f->is_java_frame()) { 1764 javaVFrame* jvf = javaVFrame::cast(f); 1765 java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci()); 1766 1767 // Print out lock information 1768 if (JavaMonitorsInStackTrace) { 1769 jvf->print_lock_info_on(st, count); 1770 } 1771 } else { 1772 // Ignore non-Java frames 1773 } 1774 1775 // Bail-out case for too deep stacks if MaxJavaStackTraceDepth > 0 1776 count++; 1777 if (MaxJavaStackTraceDepth > 0 && MaxJavaStackTraceDepth == count) return; 1778 } 1779 } 1780 1781 void JavaThread::print_active_stack_on(outputStream* st) { 1782 if (is_vthread_mounted()) { 1783 print_vthread_stack_on(st); 1784 } else { 1785 print_stack_on(st); 1786 } 1787 } 1788 1789 #if INCLUDE_JVMTI 1790 // Rebind JVMTI thread state from carrier to virtual or from virtual to carrier. 1791 JvmtiThreadState* JavaThread::rebind_to_jvmti_thread_state_of(oop thread_oop) { 1792 set_jvmti_vthread(thread_oop); 1793 1794 // unbind current JvmtiThreadState from JavaThread 1795 JvmtiThreadState::unbind_from(jvmti_thread_state(), this); 1796 1797 // bind new JvmtiThreadState to JavaThread 1798 JvmtiThreadState::bind_to(java_lang_Thread::jvmti_thread_state(thread_oop), this); 1799 1800 return jvmti_thread_state(); 1801 } 1802 #endif 1803 1804 // JVMTI PopFrame support 1805 void JavaThread::popframe_preserve_args(ByteSize size_in_bytes, void* start) { 1806 assert(_popframe_preserved_args == nullptr, "should not wipe out old PopFrame preserved arguments"); 1807 if (in_bytes(size_in_bytes) != 0) { 1808 _popframe_preserved_args = NEW_C_HEAP_ARRAY(char, in_bytes(size_in_bytes), mtThread); 1809 _popframe_preserved_args_size = in_bytes(size_in_bytes); 1810 Copy::conjoint_jbytes(start, _popframe_preserved_args, _popframe_preserved_args_size); 1811 } 1812 } 1813 1814 void* JavaThread::popframe_preserved_args() { 1815 return _popframe_preserved_args; 1816 } 1817 1818 ByteSize JavaThread::popframe_preserved_args_size() { 1819 return in_ByteSize(_popframe_preserved_args_size); 1820 } 1821 1822 WordSize JavaThread::popframe_preserved_args_size_in_words() { 1823 int sz = in_bytes(popframe_preserved_args_size()); 1824 assert(sz % wordSize == 0, "argument size must be multiple of wordSize"); 1825 return in_WordSize(sz / wordSize); 1826 } 1827 1828 void JavaThread::popframe_free_preserved_args() { 1829 assert(_popframe_preserved_args != nullptr, "should not free PopFrame preserved arguments twice"); 1830 FREE_C_HEAP_ARRAY(char, (char*)_popframe_preserved_args); 1831 _popframe_preserved_args = nullptr; 1832 _popframe_preserved_args_size = 0; 1833 } 1834 1835 #ifndef PRODUCT 1836 1837 void JavaThread::trace_frames() { 1838 tty->print_cr("[Describe stack]"); 1839 int frame_no = 1; 1840 for (StackFrameStream fst(this, true /* update */, true /* process_frames */); !fst.is_done(); fst.next()) { 1841 tty->print(" %d. ", frame_no++); 1842 fst.current()->print_value_on(tty, this); 1843 tty->cr(); 1844 } 1845 } 1846 1847 class PrintAndVerifyOopClosure: public OopClosure { 1848 protected: 1849 template <class T> inline void do_oop_work(T* p) { 1850 oop obj = RawAccess<>::oop_load(p); 1851 if (obj == nullptr) return; 1852 tty->print(INTPTR_FORMAT ": ", p2i(p)); 1853 if (oopDesc::is_oop_or_null(obj)) { 1854 if (obj->is_objArray()) { 1855 tty->print_cr("valid objArray: " INTPTR_FORMAT, p2i(obj)); 1856 } else { 1857 obj->print(); 1858 } 1859 } else { 1860 tty->print_cr("invalid oop: " INTPTR_FORMAT, p2i(obj)); 1861 } 1862 tty->cr(); 1863 } 1864 public: 1865 virtual void do_oop(oop* p) { do_oop_work(p); } 1866 virtual void do_oop(narrowOop* p) { do_oop_work(p); } 1867 }; 1868 1869 #ifdef ASSERT 1870 // Print or validate the layout of stack frames 1871 void JavaThread::print_frame_layout(int depth, bool validate_only) { 1872 ResourceMark rm; 1873 PreserveExceptionMark pm(this); 1874 FrameValues values; 1875 int frame_no = 0; 1876 for (StackFrameStream fst(this, true, true, true); !fst.is_done(); fst.next()) { 1877 fst.current()->describe(values, ++frame_no, fst.register_map()); 1878 if (depth == frame_no) break; 1879 } 1880 Continuation::describe(values); 1881 if (validate_only) { 1882 values.validate(); 1883 } else { 1884 tty->print_cr("[Describe stack layout]"); 1885 values.print(this); 1886 } 1887 } 1888 #endif 1889 1890 void JavaThread::trace_stack_from(vframe* start_vf) { 1891 ResourceMark rm; 1892 int vframe_no = 1; 1893 for (vframe* f = start_vf; f; f = f->sender()) { 1894 if (f->is_java_frame()) { 1895 javaVFrame::cast(f)->print_activation(vframe_no++); 1896 } else { 1897 f->print(); 1898 } 1899 if (vframe_no > StackPrintLimit) { 1900 tty->print_cr("...<more frames>..."); 1901 return; 1902 } 1903 } 1904 } 1905 1906 1907 void JavaThread::trace_stack() { 1908 if (!has_last_Java_frame()) return; 1909 Thread* current_thread = Thread::current(); 1910 ResourceMark rm(current_thread); 1911 HandleMark hm(current_thread); 1912 RegisterMap reg_map(this, 1913 RegisterMap::UpdateMap::include, 1914 RegisterMap::ProcessFrames::include, 1915 RegisterMap::WalkContinuation::skip); 1916 trace_stack_from(last_java_vframe(®_map)); 1917 } 1918 1919 1920 #endif // PRODUCT 1921 1922 void JavaThread::inc_held_monitor_count(int i, bool jni) { 1923 #ifdef SUPPORT_MONITOR_COUNT 1924 assert(_held_monitor_count >= 0, "Must always be greater than 0: " INT64_FORMAT, (int64_t)_held_monitor_count); 1925 _held_monitor_count += i; 1926 if (jni) { 1927 assert(_jni_monitor_count >= 0, "Must always be greater than 0: " INT64_FORMAT, (int64_t)_jni_monitor_count); 1928 _jni_monitor_count += i; 1929 } 1930 #endif 1931 } 1932 1933 void JavaThread::dec_held_monitor_count(int i, bool jni) { 1934 #ifdef SUPPORT_MONITOR_COUNT 1935 _held_monitor_count -= i; 1936 assert(_held_monitor_count >= 0, "Must always be greater than 0: " INT64_FORMAT, (int64_t)_held_monitor_count); 1937 if (jni) { 1938 _jni_monitor_count -= i; 1939 assert(_jni_monitor_count >= 0, "Must always be greater than 0: " INT64_FORMAT, (int64_t)_jni_monitor_count); 1940 } 1941 #endif 1942 } 1943 1944 frame JavaThread::vthread_last_frame() { 1945 assert (is_vthread_mounted(), "Virtual thread not mounted"); 1946 return last_frame(); 1947 } 1948 1949 frame JavaThread::carrier_last_frame(RegisterMap* reg_map) { 1950 const ContinuationEntry* entry = vthread_continuation(); 1951 guarantee (entry != nullptr, "Not a carrier thread"); 1952 frame f = entry->to_frame(); 1953 if (reg_map->process_frames()) { 1954 entry->flush_stack_processing(this); 1955 } 1956 entry->update_register_map(reg_map); 1957 return f.sender(reg_map); 1958 } 1959 1960 frame JavaThread::platform_thread_last_frame(RegisterMap* reg_map) { 1961 return is_vthread_mounted() ? carrier_last_frame(reg_map) : last_frame(); 1962 } 1963 1964 javaVFrame* JavaThread::last_java_vframe(const frame f, RegisterMap *reg_map) { 1965 assert(reg_map != nullptr, "a map must be given"); 1966 for (vframe* vf = vframe::new_vframe(&f, reg_map, this); vf; vf = vf->sender()) { 1967 if (vf->is_java_frame()) return javaVFrame::cast(vf); 1968 } 1969 return nullptr; 1970 } 1971 1972 Klass* JavaThread::security_get_caller_class(int depth) { 1973 ResetNoHandleMark rnhm; 1974 HandleMark hm(Thread::current()); 1975 1976 vframeStream vfst(this); 1977 vfst.security_get_caller_frame(depth); 1978 if (!vfst.at_end()) { 1979 return vfst.method()->method_holder(); 1980 } 1981 return nullptr; 1982 } 1983 1984 // java.lang.Thread.sleep support 1985 // Returns true if sleep time elapsed as expected, and false 1986 // if the thread was interrupted. 1987 bool JavaThread::sleep(jlong millis) { 1988 assert(this == Thread::current(), "thread consistency check"); 1989 1990 ParkEvent * const slp = this->_SleepEvent; 1991 // Because there can be races with thread interruption sending an unpark() 1992 // to the event, we explicitly reset it here to avoid an immediate return. 1993 // The actual interrupt state will be checked before we park(). 1994 slp->reset(); 1995 // Thread interruption establishes a happens-before ordering in the 1996 // Java Memory Model, so we need to ensure we synchronize with the 1997 // interrupt state. 1998 OrderAccess::fence(); 1999 2000 jlong prevtime = os::javaTimeNanos(); 2001 2002 for (;;) { 2003 // interruption has precedence over timing out 2004 if (this->is_interrupted(true)) { 2005 return false; 2006 } 2007 2008 if (millis <= 0) { 2009 return true; 2010 } 2011 2012 { 2013 ThreadBlockInVM tbivm(this); 2014 OSThreadWaitState osts(this->osthread(), false /* not Object.wait() */); 2015 slp->park(millis); 2016 } 2017 2018 // Update elapsed time tracking 2019 jlong newtime = os::javaTimeNanos(); 2020 if (newtime - prevtime < 0) { 2021 // time moving backwards, should only happen if no monotonic clock 2022 // not a guarantee() because JVM should not abort on kernel/glibc bugs 2023 assert(false, 2024 "unexpected time moving backwards detected in JavaThread::sleep()"); 2025 } else { 2026 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC; 2027 } 2028 prevtime = newtime; 2029 } 2030 } 2031 2032 // Last thread running calls java.lang.Shutdown.shutdown() 2033 void JavaThread::invoke_shutdown_hooks() { 2034 HandleMark hm(this); 2035 2036 // We could get here with a pending exception, if so clear it now. 2037 if (this->has_pending_exception()) { 2038 this->clear_pending_exception(); 2039 } 2040 2041 EXCEPTION_MARK; 2042 Klass* shutdown_klass = 2043 SystemDictionary::resolve_or_null(vmSymbols::java_lang_Shutdown(), 2044 THREAD); 2045 if (shutdown_klass != nullptr) { 2046 // SystemDictionary::resolve_or_null will return null if there was 2047 // an exception. If we cannot load the Shutdown class, just don't 2048 // call Shutdown.shutdown() at all. This will mean the shutdown hooks 2049 // won't be run. Note that if a shutdown hook was registered, 2050 // the Shutdown class would have already been loaded 2051 // (Runtime.addShutdownHook will load it). 2052 JavaValue result(T_VOID); 2053 JavaCalls::call_static(&result, 2054 shutdown_klass, 2055 vmSymbols::shutdown_name(), 2056 vmSymbols::void_method_signature(), 2057 THREAD); 2058 } 2059 CLEAR_PENDING_EXCEPTION; 2060 } 2061 2062 #ifndef PRODUCT 2063 void JavaThread::verify_cross_modify_fence_failure(JavaThread *thread) { 2064 report_vm_error(__FILE__, __LINE__, "Cross modify fence failure", "%p", thread); 2065 } 2066 #endif 2067 2068 // Helper function to create the java.lang.Thread object for a 2069 // VM-internal thread. The thread will have the given name, and be 2070 // a member of the "system" ThreadGroup. 2071 Handle JavaThread::create_system_thread_object(const char* name, TRAPS) { 2072 Handle string = java_lang_String::create_from_str(name, CHECK_NH); 2073 2074 // Initialize thread_oop to put it into the system threadGroup. 2075 // This is done by calling the Thread(ThreadGroup group, String name) constructor. 2076 Handle thread_group(THREAD, Universe::system_thread_group()); 2077 Handle thread_oop = 2078 JavaCalls::construct_new_instance(vmClasses::Thread_klass(), 2079 vmSymbols::threadgroup_string_void_signature(), 2080 thread_group, 2081 string, 2082 CHECK_NH); 2083 2084 return thread_oop; 2085 } 2086 2087 // Starts the target JavaThread as a daemon of the given priority, and 2088 // bound to the given java.lang.Thread instance. 2089 // The Threads_lock is held for the duration. 2090 void JavaThread::start_internal_daemon(JavaThread* current, JavaThread* target, 2091 Handle thread_oop, ThreadPriority prio) { 2092 2093 assert(target->osthread() != nullptr, "target thread is not properly initialized"); 2094 2095 MutexLocker mu(current, Threads_lock); 2096 2097 // Initialize the fields of the thread_oop first. 2098 2099 java_lang_Thread::set_thread(thread_oop(), target); // isAlive == true now 2100 2101 if (prio != NoPriority) { 2102 java_lang_Thread::set_priority(thread_oop(), prio); 2103 // Note: we don't call os::set_priority here. Possibly we should, 2104 // else all threads should call it themselves when they first run. 2105 } 2106 2107 java_lang_Thread::set_daemon(thread_oop()); 2108 2109 // Now bind the thread_oop to the target JavaThread. 2110 target->set_threadOopHandles(thread_oop()); 2111 2112 Threads::add(target); // target is now visible for safepoint/handshake 2113 Thread::start(target); 2114 } 2115 2116 void JavaThread::vm_exit_on_osthread_failure(JavaThread* thread) { 2117 // At this point it may be possible that no osthread was created for the 2118 // JavaThread due to lack of resources. However, since this must work 2119 // for critical system threads just check and abort if this fails. 2120 if (thread->osthread() == nullptr) { 2121 // This isn't really an OOM condition, but historically this is what 2122 // we report. 2123 vm_exit_during_initialization("java.lang.OutOfMemoryError", 2124 os::native_thread_creation_failed_msg()); 2125 } 2126 } 2127 2128 void JavaThread::pretouch_stack() { 2129 // Given an established java thread stack with usable area followed by 2130 // shadow zone and reserved/yellow/red zone, pretouch the usable area ranging 2131 // from the current frame down to the start of the shadow zone. 2132 const address end = _stack_overflow_state.shadow_zone_safe_limit(); 2133 if (is_in_full_stack(end)) { 2134 char* p1 = (char*) alloca(1); 2135 address here = (address) &p1; 2136 if (is_in_full_stack(here) && here > end) { 2137 size_t to_alloc = here - end; 2138 char* p2 = (char*) alloca(to_alloc); 2139 log_trace(os, thread)("Pretouching thread stack from " PTR_FORMAT " to " PTR_FORMAT ".", 2140 p2i(p2), p2i(end)); 2141 os::pretouch_memory(p2, p2 + to_alloc, 2142 NOT_AIX(os::vm_page_size()) AIX_ONLY(4096)); 2143 } 2144 } 2145 } 2146 2147 // Deferred OopHandle release support. 2148 2149 class OopHandleList : public CHeapObj<mtInternal> { 2150 static const int _count = 4; 2151 OopHandle _handles[_count]; 2152 OopHandleList* _next; 2153 int _index; 2154 public: 2155 OopHandleList(OopHandleList* next) : _next(next), _index(0) {} 2156 void add(OopHandle h) { 2157 assert(_index < _count, "too many additions"); 2158 _handles[_index++] = h; 2159 } 2160 ~OopHandleList() { 2161 assert(_index == _count, "usage error"); 2162 for (int i = 0; i < _index; i++) { 2163 _handles[i].release(JavaThread::thread_oop_storage()); 2164 } 2165 } 2166 OopHandleList* next() const { return _next; } 2167 }; 2168 2169 OopHandleList* JavaThread::_oop_handle_list = nullptr; 2170 2171 // Called by the ServiceThread to do the work of releasing 2172 // the OopHandles. 2173 void JavaThread::release_oop_handles() { 2174 OopHandleList* list; 2175 { 2176 MutexLocker ml(Service_lock, Mutex::_no_safepoint_check_flag); 2177 list = _oop_handle_list; 2178 _oop_handle_list = nullptr; 2179 } 2180 assert(!SafepointSynchronize::is_at_safepoint(), "cannot be called at a safepoint"); 2181 2182 while (list != nullptr) { 2183 OopHandleList* l = list; 2184 list = l->next(); 2185 delete l; 2186 } 2187 } 2188 2189 // Add our OopHandles for later release. 2190 void JavaThread::add_oop_handles_for_release() { 2191 MutexLocker ml(Service_lock, Mutex::_no_safepoint_check_flag); 2192 OopHandleList* new_head = new OopHandleList(_oop_handle_list); 2193 new_head->add(_threadObj); 2194 new_head->add(_vthread); 2195 new_head->add(_jvmti_vthread); 2196 new_head->add(_scopedValueCache); 2197 _oop_handle_list = new_head; 2198 Service_lock->notify_all(); 2199 }