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 #ifndef SHARE_RUNTIME_JAVATHREAD_HPP 27 #define SHARE_RUNTIME_JAVATHREAD_HPP 28 29 #include "jni.h" 30 #include "memory/allocation.hpp" 31 #include "oops/oop.hpp" 32 #include "oops/oopHandle.hpp" 33 #include "runtime/continuationEntry.hpp" 34 #include "runtime/frame.hpp" 35 #include "runtime/globals.hpp" 36 #include "runtime/handshake.hpp" 37 #include "runtime/javaFrameAnchor.hpp" 38 #include "runtime/lockStack.hpp" 39 #include "runtime/park.hpp" 40 #include "utilities/ticks.hpp" 41 #include "runtime/safepointMechanism.hpp" 42 #include "runtime/stackWatermarkSet.hpp" 43 #include "runtime/stackOverflow.hpp" 44 #include "runtime/thread.hpp" 45 #include "runtime/threadHeapSampler.hpp" 46 #include "runtime/threadIdentifier.hpp" 47 #include "runtime/threadStatisticalInfo.hpp" 48 #include "utilities/exceptions.hpp" 49 #include "utilities/globalDefinitions.hpp" 50 #include "utilities/macros.hpp" 51 #if INCLUDE_JFR 52 #include "jfr/support/jfrThreadExtension.hpp" 53 #endif 54 55 class AsyncExceptionHandshake; 56 class DeoptResourceMark; 57 class InternalOOMEMark; 58 class JNIHandleBlock; 59 class JVMCIRuntime; 60 61 class JvmtiDeferredUpdates; 62 class JvmtiSampledObjectAllocEventCollector; 63 class JvmtiThreadState; 64 65 class Metadata; 66 class ObjectMonitor; 67 class OopHandleList; 68 class OopStorage; 69 class OSThread; 70 71 class ThreadsList; 72 class ThreadSafepointState; 73 class ThreadStatistics; 74 75 class vframeArray; 76 class vframe; 77 class javaVFrame; 78 79 class JavaThread; 80 typedef void (*ThreadFunction)(JavaThread*, TRAPS); 81 82 class EventVirtualThreadPinned; 83 84 class JavaThread: public Thread { 85 friend class VMStructs; 86 friend class JVMCIVMStructs; 87 friend class WhiteBox; 88 friend class ThreadsSMRSupport; // to access _threadObj for exiting_threads_oops_do 89 friend class HandshakeState; 90 friend class Continuation; 91 friend class Threads; 92 friend class ServiceThread; // for deferred OopHandle release access 93 private: 94 bool _on_thread_list; // Is set when this JavaThread is added to the Threads list 95 96 // All references to Java objects managed via OopHandles. These 97 // have to be released by the ServiceThread after the JavaThread has 98 // terminated - see add_oop_handles_for_release(). 99 OopHandle _threadObj; // The Java level thread object 100 OopHandle _vthread; // the value returned by Thread.currentThread(): the virtual thread, if mounted, otherwise _threadObj 101 OopHandle _jvmti_vthread; 102 OopHandle _scopedValueCache; 103 104 static OopStorage* _thread_oop_storage; 105 106 #ifdef ASSERT 107 private: 108 int _java_call_counter; 109 110 public: 111 int java_call_counter() { return _java_call_counter; } 112 void inc_java_call_counter() { _java_call_counter++; } 113 void dec_java_call_counter() { 114 assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper"); 115 _java_call_counter--; 116 } 117 private: // restore original namespace restriction 118 #endif // ifdef ASSERT 119 120 JavaFrameAnchor _anchor; // Encapsulation of current java frame and it state 121 122 ThreadFunction _entry_point; 123 124 JNIEnv _jni_environment; 125 126 // Deopt support 127 DeoptResourceMark* _deopt_mark; // Holds special ResourceMark for deoptimization 128 129 nmethod* _deopt_nmethod; // nmethod that is currently being deoptimized 130 vframeArray* _vframe_array_head; // Holds the heap of the active vframeArrays 131 vframeArray* _vframe_array_last; // Holds last vFrameArray we popped 132 // Holds updates by JVMTI agents for compiled frames that cannot be performed immediately. They 133 // will be carried out as soon as possible which, in most cases, is just before deoptimization of 134 // the frame, when control returns to it. 135 JvmtiDeferredUpdates* _jvmti_deferred_updates; 136 137 // Handshake value for fixing 6243940. We need a place for the i2c 138 // adapter to store the callee Method*. This value is NEVER live 139 // across a gc point so it does NOT have to be gc'd 140 // The handshake is open ended since we can't be certain that it will 141 // be nulled. This is because we rarely ever see the race and end up 142 // in handle_wrong_method which is the backend of the handshake. See 143 // code in i2c adapters and handle_wrong_method. 144 145 Method* _callee_target; 146 147 // Used to pass back results to the interpreter or generated code running Java code. 148 oop _vm_result; // oop result is GC-preserved 149 Metadata* _vm_result_2; // non-oop result 150 151 // See ReduceInitialCardMarks: this holds the precise space interval of 152 // the most recent slow path allocation for which compiled code has 153 // elided card-marks for performance along the fast-path. 154 MemRegion _deferred_card_mark; 155 156 ObjectMonitor* volatile _current_pending_monitor; // ObjectMonitor this thread is waiting to lock 157 bool _current_pending_monitor_is_from_java; // locking is from Java code 158 ObjectMonitor* volatile _current_waiting_monitor; // ObjectMonitor on which this thread called Object.wait() 159 160 // Active_handles points to a block of handles 161 JNIHandleBlock* _active_handles; 162 163 // One-element thread local free list 164 JNIHandleBlock* _free_handle_block; 165 166 // ID used as owner for inflated monitors. Same as the j.l.Thread.tid of the 167 // current _vthread object, except during creation of the primordial and JNI 168 // attached thread cases where this field can have a temporary value. Also, 169 // calls to VirtualThread.switchToCarrierThread will temporarily change _vthread 170 // to refer to the carrier while preserving the j.l.Thread.tid of the virtual 171 // thread in this field. 172 int64_t _lock_id; 173 174 public: 175 void set_lock_id(int64_t tid) { 176 assert(tid >= ThreadIdentifier::initial() && tid < ThreadIdentifier::current(), "invalid tid"); 177 _lock_id = tid; 178 } 179 int64_t lock_id() const { return _lock_id; } 180 181 // For tracking the heavyweight monitor the thread is pending on. 182 ObjectMonitor* current_pending_monitor() { 183 // Use Atomic::load() to prevent data race between concurrent modification and 184 // concurrent readers, e.g. ThreadService::get_current_contended_monitor(). 185 // Especially, reloading pointer from thread after null check must be prevented. 186 return Atomic::load(&_current_pending_monitor); 187 } 188 void set_current_pending_monitor(ObjectMonitor* monitor) { 189 Atomic::store(&_current_pending_monitor, monitor); 190 } 191 void set_current_pending_monitor_is_from_java(bool from_java) { 192 _current_pending_monitor_is_from_java = from_java; 193 } 194 bool current_pending_monitor_is_from_java() { 195 return _current_pending_monitor_is_from_java; 196 } 197 ObjectMonitor* current_waiting_monitor() { 198 // See the comment in current_pending_monitor() above. 199 return Atomic::load(&_current_waiting_monitor); 200 } 201 void set_current_waiting_monitor(ObjectMonitor* monitor) { 202 Atomic::store(&_current_waiting_monitor, monitor); 203 } 204 205 // JNI handle support 206 JNIHandleBlock* active_handles() const { return _active_handles; } 207 void set_active_handles(JNIHandleBlock* block) { _active_handles = block; } 208 JNIHandleBlock* free_handle_block() const { return _free_handle_block; } 209 void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; } 210 211 void push_jni_handle_block(); 212 void pop_jni_handle_block(); 213 214 private: 215 enum SuspendFlags { 216 // NOTE: avoid using the sign-bit as cc generates different test code 217 // when the sign-bit is used, and sometimes incorrectly - see CR 6398077 218 _trace_flag = 0x00000004U, // call tracing backend 219 _obj_deopt = 0x00000008U // suspend for object reallocation and relocking for JVMTI agent 220 }; 221 222 // various suspension related flags - atomically updated 223 volatile uint32_t _suspend_flags; 224 225 inline void set_suspend_flag(SuspendFlags f); 226 inline void clear_suspend_flag(SuspendFlags f); 227 228 public: 229 inline void set_trace_flag(); 230 inline void clear_trace_flag(); 231 inline void set_obj_deopt_flag(); 232 inline void clear_obj_deopt_flag(); 233 bool is_trace_suspend() { return (_suspend_flags & _trace_flag) != 0; } 234 bool is_obj_deopt_suspend() { return (_suspend_flags & _obj_deopt) != 0; } 235 236 // Asynchronous exception support 237 private: 238 friend class InstallAsyncExceptionHandshake; 239 friend class AsyncExceptionHandshake; 240 friend class HandshakeState; 241 242 void handle_async_exception(oop java_throwable); 243 public: 244 void install_async_exception(AsyncExceptionHandshake* aec = nullptr); 245 bool has_async_exception_condition(); 246 inline void set_pending_unsafe_access_error(); 247 static void send_async_exception(JavaThread* jt, oop java_throwable); 248 249 class NoAsyncExceptionDeliveryMark : public StackObj { 250 friend JavaThread; 251 JavaThread *_target; 252 inline NoAsyncExceptionDeliveryMark(JavaThread *t); 253 inline ~NoAsyncExceptionDeliveryMark(); 254 }; 255 256 // Safepoint support 257 public: // Expose _thread_state for SafeFetchInt() 258 volatile JavaThreadState _thread_state; 259 ThreadSafepointState* _safepoint_state; // Holds information about a thread during a safepoint 260 address _saved_exception_pc; // Saved pc of instruction where last implicit exception happened 261 NOT_PRODUCT(bool _requires_cross_modify_fence;) // State used by VerifyCrossModifyFence 262 #ifdef ASSERT 263 // Debug support for checking if code allows safepoints or not. 264 // Safepoints in the VM can happen because of allocation, invoking a VM operation, or blocking on 265 // mutex, or blocking on an object synchronizer (Java locking). 266 // If _no_safepoint_count is non-zero, then an assertion failure will happen in any of 267 // the above cases. The class NoSafepointVerifier is used to set this counter. 268 int _no_safepoint_count; // If 0, thread allow a safepoint to happen 269 270 public: 271 void inc_no_safepoint_count() { _no_safepoint_count++; } 272 void dec_no_safepoint_count() { _no_safepoint_count--; } 273 bool is_in_no_safepoint_scope() { return _no_safepoint_count > 0; } 274 #endif // ASSERT 275 public: 276 // These functions check conditions before possibly going to a safepoint. 277 // including NoSafepointVerifier. 278 void check_for_valid_safepoint_state() NOT_DEBUG_RETURN; 279 void check_possible_safepoint() NOT_DEBUG_RETURN; 280 281 #ifdef ASSERT 282 private: 283 volatile uint64_t _visited_for_critical_count; 284 285 public: 286 void set_visited_for_critical_count(uint64_t safepoint_id) { 287 assert(_visited_for_critical_count == 0, "Must be reset before set"); 288 assert((safepoint_id & 0x1) == 1, "Must be odd"); 289 _visited_for_critical_count = safepoint_id; 290 } 291 void reset_visited_for_critical_count(uint64_t safepoint_id) { 292 assert(_visited_for_critical_count == safepoint_id, "Was not visited"); 293 _visited_for_critical_count = 0; 294 } 295 bool was_visited_for_critical_count(uint64_t safepoint_id) const { 296 return _visited_for_critical_count == safepoint_id; 297 } 298 #endif // ASSERT 299 300 // JavaThread termination support 301 public: 302 enum TerminatedTypes { 303 _not_terminated = 0xDEAD - 3, 304 _thread_exiting, // JavaThread::exit() has been called for this thread 305 _thread_gc_barrier_detached, // thread's GC barrier has been detached 306 _thread_terminated, // JavaThread is removed from thread list 307 _vm_exited // JavaThread is still executing native code, but VM is terminated 308 // only VM_Exit can set _vm_exited 309 }; 310 311 private: 312 // In general a JavaThread's _terminated field transitions as follows: 313 // 314 // _not_terminated => _thread_exiting => _thread_gc_barrier_detached => _thread_terminated 315 // 316 // _vm_exited is a special value to cover the case of a JavaThread 317 // executing native code after the VM itself is terminated. 318 // 319 // A JavaThread that fails to JNI attach has these _terminated field transitions: 320 // _not_terminated => _thread_terminated 321 // 322 volatile TerminatedTypes _terminated; 323 324 jint _in_deopt_handler; // count of deoptimization 325 // handlers thread is in 326 volatile bool _doing_unsafe_access; // Thread may fault due to unsafe access 327 bool _do_not_unlock_if_synchronized; // Do not unlock the receiver of a synchronized method (since it was 328 // never locked) when throwing an exception. Used by interpreter only. 329 #if INCLUDE_JVMTI 330 volatile bool _carrier_thread_suspended; // Carrier thread is externally suspended 331 bool _is_in_VTMS_transition; // thread is in virtual thread mount state transition 332 bool _is_in_tmp_VTMS_transition; // thread is in temporary virtual thread mount state transition 333 bool _is_disable_suspend; // JVMTI suspend is temporarily disabled; used on current thread only 334 bool _VTMS_transition_mark; // used for sync between VTMS transitions and disablers 335 bool _pending_jvmti_unmount_event; // When preempting we post unmount event at unmount end rather than start 336 bool _on_monitor_waited_event; // Avoid callee arg processing for enterSpecial when posting waited event 337 ObjectMonitor* _contended_entered_monitor; // Monitor for pending monitor_contended_entered callback 338 #ifdef ASSERT 339 bool _is_VTMS_transition_disabler; // thread currently disabled VTMS transitions 340 #endif 341 #endif 342 343 // JNI attach states: 344 enum JNIAttachStates { 345 _not_attaching_via_jni = 1, // thread is not attaching via JNI 346 _attaching_via_jni, // thread is attaching via JNI 347 _attached_via_jni // thread has attached via JNI 348 }; 349 350 // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni. 351 // A native thread that is attaching via JNI starts with a value 352 // of _attaching_via_jni and transitions to _attached_via_jni. 353 volatile JNIAttachStates _jni_attach_state; 354 355 // In scope of an InternalOOMEMark? 356 bool _is_in_internal_oome_mark; 357 358 #if INCLUDE_JVMCI 359 // The _pending_* fields below are used to communicate extra information 360 // from an uncommon trap in JVMCI compiled code to the uncommon trap handler. 361 362 // Communicates the DeoptReason and DeoptAction of the uncommon trap 363 int _pending_deoptimization; 364 365 // Specifies whether the uncommon trap is to bci 0 of a synchronized method 366 // before the monitor has been acquired. 367 bool _pending_monitorenter; 368 369 // Specifies if the DeoptReason for the last uncommon trap was Reason_transfer_to_interpreter 370 bool _pending_transfer_to_interpreter; 371 372 // An id of a speculation that JVMCI compiled code can use to further describe and 373 // uniquely identify the speculative optimization guarded by an uncommon trap. 374 // See JVMCINMethodData::SPECULATION_LENGTH_BITS for further details. 375 jlong _pending_failed_speculation; 376 377 // These fields are mutually exclusive in terms of live ranges. 378 union { 379 // Communicates the pc at which the most recent implicit exception occurred 380 // from the signal handler to a deoptimization stub. 381 address _implicit_exception_pc; 382 383 // Communicates an alternative call target to an i2c stub from a JavaCall . 384 address _alternate_call_target; 385 } _jvmci; 386 387 // The JVMCIRuntime in a JVMCI shared library 388 JVMCIRuntime* _libjvmci_runtime; 389 390 // Support for high precision, thread sensitive counters in JVMCI compiled code. 391 jlong* _jvmci_counters; 392 393 // Fast thread locals for use by JVMCI 394 jlong _jvmci_reserved0; 395 jlong _jvmci_reserved1; 396 oop _jvmci_reserved_oop0; 397 398 // This field is used to keep an nmethod visible to the GC so that it and its contained oops can 399 // be kept alive 400 nmethod* _live_nmethod; 401 402 public: 403 static jlong* _jvmci_old_thread_counters; 404 static void collect_counters(jlong* array, int length); 405 406 bool resize_counters(int current_size, int new_size); 407 408 static bool resize_all_jvmci_counters(int new_size); 409 410 void set_jvmci_reserved_oop0(oop value) { 411 _jvmci_reserved_oop0 = value; 412 } 413 414 oop get_jvmci_reserved_oop0() { 415 return _jvmci_reserved_oop0; 416 } 417 418 void set_jvmci_reserved0(jlong value) { 419 _jvmci_reserved0 = value; 420 } 421 422 jlong get_jvmci_reserved0() { 423 return _jvmci_reserved0; 424 } 425 426 void set_jvmci_reserved1(jlong value) { 427 _jvmci_reserved1 = value; 428 } 429 430 jlong get_jvmci_reserved1() { 431 return _jvmci_reserved1; 432 } 433 434 void set_live_nmethod(nmethod* nm) { 435 assert(_live_nmethod == nullptr, "only one"); 436 _live_nmethod = nm; 437 } 438 439 void clear_live_nmethod() { 440 _live_nmethod = nullptr; 441 } 442 443 private: 444 #endif // INCLUDE_JVMCI 445 446 StackOverflow _stack_overflow_state; 447 448 void pretouch_stack(); 449 450 // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is 451 // used to temp. parsing values into and out of the runtime system during exception handling for compiled 452 // code) 453 volatile oop _exception_oop; // Exception thrown in compiled code 454 volatile address _exception_pc; // PC where exception happened 455 volatile address _exception_handler_pc; // PC for handler of exception 456 volatile int _is_method_handle_return; // true (== 1) if the current exception PC is a MethodHandle call site. 457 458 private: 459 // support for JNI critical regions 460 jint _jni_active_critical; // count of entries into JNI critical region 461 462 // Checked JNI: function name requires exception check 463 char* _pending_jni_exception_check_fn; 464 465 // For deadlock detection. 466 int _depth_first_number; 467 468 // JVMTI PopFrame support 469 // This is set to popframe_pending to signal that top Java frame should be popped immediately 470 int _popframe_condition; 471 472 // If reallocation of scalar replaced objects fails, we throw OOM 473 // and during exception propagation, pop the top 474 // _frames_to_pop_failed_realloc frames, the ones that reference 475 // failed reallocations. 476 int _frames_to_pop_failed_realloc; 477 478 ContinuationEntry* _cont_entry; 479 intptr_t* _cont_fastpath; // the sp of the oldest known interpreted/call_stub frame inside the 480 // continuation that we know about 481 int _cont_fastpath_thread_state; // whether global thread state allows continuation fastpath (JVMTI) 482 483 // It's signed for error detection. 484 intx _held_monitor_count; // used by continuations for fast lock detection 485 intx _jni_monitor_count; 486 ObjectMonitor* _unlocked_inflated_monitor; 487 488 // This is the field we poke in the interpreter and native 489 // wrapper (Object.wait) to check for preemption. 490 address _preempt_alternate_return; 491 // When preempting on monitorenter we could have acquired the 492 // monitor after freezing all vthread frames. In that case we 493 // set this field so that in the preempt stub we call thaw again 494 // instead of unmounting. 495 bool _preemption_cancelled; 496 // For Object.wait() we set this field to know if we need to 497 // throw IE at the end of thawing before returning to Java. 498 bool _pending_interrupted_exception; 499 500 public: 501 bool preemption_cancelled() { return _preemption_cancelled; } 502 void set_preemption_cancelled(bool b) { _preemption_cancelled = b; } 503 504 bool pending_interrupted_exception() { return _pending_interrupted_exception; } 505 void set_pending_interrupted_exception(bool b) { _pending_interrupted_exception = b; } 506 507 bool preempting() { return _preempt_alternate_return != nullptr; } 508 void set_preempt_alternate_return(address val) { _preempt_alternate_return = val; } 509 510 private: 511 512 friend class VMThread; 513 friend class ThreadWaitTransition; 514 friend class VM_Exit; 515 516 // Stack watermark barriers. 517 StackWatermarks _stack_watermarks; 518 519 public: 520 inline StackWatermarks* stack_watermarks() { return &_stack_watermarks; } 521 522 public: 523 // Constructor 524 JavaThread(MemTag mem_tag = mtThread); // delegating constructor 525 JavaThread(ThreadFunction entry_point, size_t stack_size = 0, MemTag mem_tag = mtThread); 526 ~JavaThread(); 527 528 // Factory method to create a new JavaThread whose attach state is "is attaching" 529 static JavaThread* create_attaching_thread(); 530 531 #ifdef ASSERT 532 // verify this JavaThread hasn't be published in the Threads::list yet 533 void verify_not_published(); 534 #endif // ASSERT 535 536 StackOverflow* stack_overflow_state() { return &_stack_overflow_state; } 537 538 //JNI functiontable getter/setter for JVMTI jni function table interception API. 539 void set_jni_functions(struct JNINativeInterface_* functionTable) { 540 _jni_environment.functions = functionTable; 541 } 542 struct JNINativeInterface_* get_jni_functions() { 543 return (struct JNINativeInterface_ *)_jni_environment.functions; 544 } 545 546 // This function is called at thread creation to allow 547 // platform specific thread variables to be initialized. 548 void cache_global_variables(); 549 550 // Executes Shutdown.shutdown() 551 void invoke_shutdown_hooks(); 552 553 // Cleanup on thread exit 554 enum ExitType { 555 normal_exit, 556 jni_detach 557 }; 558 void exit(bool destroy_vm, ExitType exit_type = normal_exit); 559 560 void cleanup_failed_attach_current_thread(bool is_daemon); 561 562 // Testers 563 virtual bool is_Java_thread() const { return true; } 564 virtual bool can_call_java() const { return true; } 565 566 virtual bool is_active_Java_thread() const; 567 568 // Thread oop. threadObj() can be null for initial JavaThread 569 // (or for threads attached via JNI) 570 oop threadObj() const; 571 void set_threadOopHandles(oop p); 572 oop vthread() const; 573 void set_vthread(oop p); 574 oop scopedValueCache() const; 575 void set_scopedValueCache(oop p); 576 void clear_scopedValueBindings(); 577 oop jvmti_vthread() const; 578 void set_jvmti_vthread(oop p); 579 oop vthread_or_thread() const; 580 581 // Prepare thread and add to priority queue. If a priority is 582 // not specified, use the priority of the thread object. Threads_lock 583 // must be held while this function is called. 584 void prepare(jobject jni_thread, ThreadPriority prio=NoPriority); 585 586 void set_saved_exception_pc(address pc) { _saved_exception_pc = pc; } 587 address saved_exception_pc() { return _saved_exception_pc; } 588 589 ThreadFunction entry_point() const { return _entry_point; } 590 591 // Allocates a new Java level thread object for this thread. thread_name may be null. 592 void allocate_threadObj(Handle thread_group, const char* thread_name, bool daemon, TRAPS); 593 594 // Last frame anchor routines 595 596 JavaFrameAnchor* frame_anchor(void) { return &_anchor; } 597 598 // last_Java_sp 599 bool has_last_Java_frame() const { return _anchor.has_last_Java_frame(); } 600 intptr_t* last_Java_sp() const { return _anchor.last_Java_sp(); } 601 602 // last_Java_pc 603 604 address last_Java_pc(void) { return _anchor.last_Java_pc(); } 605 606 // Safepoint support 607 inline JavaThreadState thread_state() const; 608 inline void set_thread_state(JavaThreadState s); 609 inline void set_thread_state_fence(JavaThreadState s); // fence after setting thread state 610 inline ThreadSafepointState* safepoint_state() const; 611 inline void set_safepoint_state(ThreadSafepointState* state); 612 inline bool is_at_poll_safepoint(); 613 614 // JavaThread termination and lifecycle support: 615 void smr_delete(); 616 bool on_thread_list() const { return _on_thread_list; } 617 void set_on_thread_list() { _on_thread_list = true; } 618 619 // thread has called JavaThread::exit(), thread's GC barrier is detached 620 // or thread is terminated 621 bool is_exiting() const; 622 // thread's GC barrier is NOT detached and thread is NOT terminated 623 bool is_oop_safe() const; 624 // thread is terminated (no longer on the threads list); the thread must 625 // be protected by a ThreadsListHandle to avoid potential crashes. 626 bool check_is_terminated(TerminatedTypes l_terminated) const { 627 return l_terminated == _thread_terminated || l_terminated == _vm_exited; 628 } 629 bool is_terminated() const; 630 void set_terminated(TerminatedTypes t); 631 632 void block_if_vm_exited(); 633 634 bool doing_unsafe_access() { return _doing_unsafe_access; } 635 void set_doing_unsafe_access(bool val) { _doing_unsafe_access = val; } 636 637 bool do_not_unlock_if_synchronized() { return _do_not_unlock_if_synchronized; } 638 void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; } 639 640 SafepointMechanism::ThreadData* poll_data() { return &_poll_data; } 641 642 static ByteSize polling_word_offset() { 643 ByteSize offset = byte_offset_of(Thread, _poll_data) + 644 byte_offset_of(SafepointMechanism::ThreadData, _polling_word); 645 // At least on x86_64, safepoint polls encode the offset as disp8 imm. 646 assert(in_bytes(offset) < 128, "Offset >= 128"); 647 return offset; 648 } 649 650 static ByteSize polling_page_offset() { 651 ByteSize offset = byte_offset_of(Thread, _poll_data) + 652 byte_offset_of(SafepointMechanism::ThreadData, _polling_page); 653 // At least on x86_64, safepoint polls encode the offset as disp8 imm. 654 assert(in_bytes(offset) < 128, "Offset >= 128"); 655 return offset; 656 } 657 658 void set_requires_cross_modify_fence(bool val) PRODUCT_RETURN NOT_PRODUCT({ _requires_cross_modify_fence = val; }) 659 660 // Continuation support 661 ContinuationEntry* last_continuation() const { return _cont_entry; } 662 void set_cont_fastpath(intptr_t* x) { _cont_fastpath = x; } 663 void push_cont_fastpath(intptr_t* sp) { if (sp > _cont_fastpath) _cont_fastpath = sp; } 664 void set_cont_fastpath_thread_state(bool x) { _cont_fastpath_thread_state = (int)x; } 665 intptr_t* raw_cont_fastpath() const { return _cont_fastpath; } 666 bool cont_fastpath() const { return _cont_fastpath == nullptr && _cont_fastpath_thread_state != 0; } 667 bool cont_fastpath_thread_state() const { return _cont_fastpath_thread_state != 0; } 668 669 void inc_held_monitor_count(intx i = 1, bool jni = false); 670 void dec_held_monitor_count(intx i = 1, bool jni = false); 671 672 intx held_monitor_count() { return _held_monitor_count; } 673 intx jni_monitor_count() { return _jni_monitor_count; } 674 void clear_jni_monitor_count() { _jni_monitor_count = 0; } 675 676 // Support for SharedRuntime::monitor_exit_helper() 677 ObjectMonitor* unlocked_inflated_monitor() const { return _unlocked_inflated_monitor; } 678 void clear_unlocked_inflated_monitor() { 679 _unlocked_inflated_monitor = nullptr; 680 } 681 682 inline bool is_vthread_mounted() const; 683 inline const ContinuationEntry* vthread_continuation() const; 684 685 private: 686 DEBUG_ONLY(void verify_frame_info();) 687 688 // Support for thread handshake operations 689 HandshakeState _handshake; 690 public: 691 HandshakeState* handshake_state() { return &_handshake; } 692 693 // A JavaThread can always safely operate on it self and other threads 694 // can do it safely if they are the active handshaker. 695 bool is_handshake_safe_for(Thread* th) const { 696 return _handshake.active_handshaker() == th || this == th; 697 } 698 699 // Suspend/resume support for JavaThread 700 // higher-level suspension/resume logic called by the public APIs 701 bool java_suspend(); 702 bool java_resume(); 703 bool is_suspended() { return _handshake.is_suspended(); } 704 705 // Check for async exception in addition to safepoint. 706 static void check_special_condition_for_native_trans(JavaThread *thread); 707 708 // Synchronize with another thread that is deoptimizing objects of the 709 // current thread, i.e. reverts optimizations based on escape analysis. 710 void wait_for_object_deoptimization(); 711 712 #if INCLUDE_JVMTI 713 inline void set_carrier_thread_suspended(); 714 inline void clear_carrier_thread_suspended(); 715 716 bool is_carrier_thread_suspended() const { 717 return _carrier_thread_suspended; 718 } 719 720 bool is_in_VTMS_transition() const { return _is_in_VTMS_transition; } 721 bool is_in_tmp_VTMS_transition() const { return _is_in_tmp_VTMS_transition; } 722 bool is_in_any_VTMS_transition() const { return _is_in_VTMS_transition || _is_in_tmp_VTMS_transition; } 723 724 void set_is_in_VTMS_transition(bool val); 725 void toggle_is_in_tmp_VTMS_transition() { _is_in_tmp_VTMS_transition = !_is_in_tmp_VTMS_transition; }; 726 727 bool is_disable_suspend() const { return _is_disable_suspend; } 728 void toggle_is_disable_suspend() { _is_disable_suspend = !_is_disable_suspend; }; 729 730 bool VTMS_transition_mark() const { return Atomic::load(&_VTMS_transition_mark); } 731 void set_VTMS_transition_mark(bool val) { Atomic::store(&_VTMS_transition_mark, val); } 732 733 bool pending_jvmti_unmount_event() { return _pending_jvmti_unmount_event; } 734 void set_pending_jvmti_unmount_event(bool val) { _pending_jvmti_unmount_event = val; } 735 736 bool on_monitor_waited_event() { return _on_monitor_waited_event; } 737 void set_on_monitor_waited_event(bool val) { _on_monitor_waited_event = val; } 738 739 bool pending_contended_entered_event() { return _contended_entered_monitor != nullptr; } 740 ObjectMonitor* contended_entered_monitor() { return _contended_entered_monitor; } 741 #ifdef ASSERT 742 bool is_VTMS_transition_disabler() const { return _is_VTMS_transition_disabler; } 743 void set_is_VTMS_transition_disabler(bool val); 744 #endif 745 #endif 746 747 void set_contended_entered_monitor(ObjectMonitor* val) NOT_JVMTI_RETURN JVMTI_ONLY({ _contended_entered_monitor = val; }) 748 749 // Support for object deoptimization and JFR suspension 750 void handle_special_runtime_exit_condition(); 751 bool has_special_runtime_exit_condition() { 752 return (_suspend_flags & (_obj_deopt JFR_ONLY(| _trace_flag))) != 0; 753 } 754 755 // Stack-locking support (not for LM_LIGHTWEIGHT) 756 bool is_lock_owned(address adr) const; 757 758 // Accessors for vframe array top 759 // The linked list of vframe arrays are sorted on sp. This means when we 760 // unpack the head must contain the vframe array to unpack. 761 void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; } 762 vframeArray* vframe_array_head() const { return _vframe_array_head; } 763 764 // Side structure for deferring update of java frame locals until deopt occurs 765 JvmtiDeferredUpdates* deferred_updates() const { return _jvmti_deferred_updates; } 766 void set_deferred_updates(JvmtiDeferredUpdates* du) { _jvmti_deferred_updates = du; } 767 768 // These only really exist to make debugging deopt problems simpler 769 770 void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; } 771 vframeArray* vframe_array_last() const { return _vframe_array_last; } 772 773 // The special resourceMark used during deoptimization 774 775 void set_deopt_mark(DeoptResourceMark* value) { _deopt_mark = value; } 776 DeoptResourceMark* deopt_mark(void) { return _deopt_mark; } 777 778 void set_deopt_compiled_method(nmethod* nm) { _deopt_nmethod = nm; } 779 nmethod* deopt_compiled_method() { return _deopt_nmethod; } 780 781 Method* callee_target() const { return _callee_target; } 782 void set_callee_target (Method* x) { _callee_target = x; } 783 784 // Oop results of vm runtime calls 785 oop vm_result() const { return _vm_result; } 786 void set_vm_result (oop x) { _vm_result = x; } 787 788 void set_vm_result_2 (Metadata* x) { _vm_result_2 = x; } 789 790 MemRegion deferred_card_mark() const { return _deferred_card_mark; } 791 void set_deferred_card_mark(MemRegion mr) { _deferred_card_mark = mr; } 792 793 // Is thread in scope of an InternalOOMEMark? 794 bool is_in_internal_oome_mark() const { return _is_in_internal_oome_mark; } 795 void set_is_in_internal_oome_mark(bool b) { _is_in_internal_oome_mark = b; } 796 797 #if INCLUDE_JVMCI 798 jlong pending_failed_speculation() const { return _pending_failed_speculation; } 799 void set_pending_monitorenter(bool b) { _pending_monitorenter = b; } 800 void set_pending_deoptimization(int reason) { _pending_deoptimization = reason; } 801 void set_pending_failed_speculation(jlong failed_speculation) { _pending_failed_speculation = failed_speculation; } 802 void set_pending_transfer_to_interpreter(bool b) { _pending_transfer_to_interpreter = b; } 803 void set_jvmci_alternate_call_target(address a) { assert(_jvmci._alternate_call_target == nullptr, "must be"); _jvmci._alternate_call_target = a; } 804 void set_jvmci_implicit_exception_pc(address a) { assert(_jvmci._implicit_exception_pc == nullptr, "must be"); _jvmci._implicit_exception_pc = a; } 805 806 JVMCIRuntime* libjvmci_runtime() const { return _libjvmci_runtime; } 807 void set_libjvmci_runtime(JVMCIRuntime* rt) { 808 assert((_libjvmci_runtime == nullptr && rt != nullptr) || (_libjvmci_runtime != nullptr && rt == nullptr), "must be"); 809 _libjvmci_runtime = rt; 810 } 811 #endif // INCLUDE_JVMCI 812 813 // Exception handling for compiled methods 814 oop exception_oop() const; 815 address exception_pc() const { return _exception_pc; } 816 817 void set_exception_oop(oop o); 818 void set_exception_pc(address a) { _exception_pc = a; } 819 void set_exception_handler_pc(address a) { _exception_handler_pc = a; } 820 void set_is_method_handle_return(bool value) { _is_method_handle_return = value ? 1 : 0; } 821 822 void clear_exception_oop_and_pc() { 823 set_exception_oop(nullptr); 824 set_exception_pc(nullptr); 825 } 826 827 // Check if address is in the usable part of the stack (excludes protected 828 // guard pages). Can be applied to any thread and is an approximation for 829 // using is_in_live_stack when the query has to happen from another thread. 830 bool is_in_usable_stack(address adr) const { 831 return is_in_stack_range_incl(adr, _stack_overflow_state.stack_reserved_zone_base()); 832 } 833 834 // Misc. accessors/mutators 835 static ByteSize scopedValueCache_offset() { return byte_offset_of(JavaThread, _scopedValueCache); } 836 837 // For assembly stub generation 838 static ByteSize threadObj_offset() { return byte_offset_of(JavaThread, _threadObj); } 839 static ByteSize vthread_offset() { return byte_offset_of(JavaThread, _vthread); } 840 static ByteSize jni_environment_offset() { return byte_offset_of(JavaThread, _jni_environment); } 841 static ByteSize pending_jni_exception_check_fn_offset() { 842 return byte_offset_of(JavaThread, _pending_jni_exception_check_fn); 843 } 844 static ByteSize last_Java_sp_offset() { 845 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset(); 846 } 847 static ByteSize last_Java_pc_offset() { 848 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset(); 849 } 850 static ByteSize frame_anchor_offset() { 851 return byte_offset_of(JavaThread, _anchor); 852 } 853 static ByteSize callee_target_offset() { return byte_offset_of(JavaThread, _callee_target); } 854 static ByteSize vm_result_offset() { return byte_offset_of(JavaThread, _vm_result); } 855 static ByteSize vm_result_2_offset() { return byte_offset_of(JavaThread, _vm_result_2); } 856 static ByteSize thread_state_offset() { return byte_offset_of(JavaThread, _thread_state); } 857 static ByteSize saved_exception_pc_offset() { return byte_offset_of(JavaThread, _saved_exception_pc); } 858 static ByteSize osthread_offset() { return byte_offset_of(JavaThread, _osthread); } 859 #if INCLUDE_JVMCI 860 static ByteSize pending_deoptimization_offset() { return byte_offset_of(JavaThread, _pending_deoptimization); } 861 static ByteSize pending_monitorenter_offset() { return byte_offset_of(JavaThread, _pending_monitorenter); } 862 static ByteSize jvmci_alternate_call_target_offset() { return byte_offset_of(JavaThread, _jvmci._alternate_call_target); } 863 static ByteSize jvmci_implicit_exception_pc_offset() { return byte_offset_of(JavaThread, _jvmci._implicit_exception_pc); } 864 static ByteSize jvmci_counters_offset() { return byte_offset_of(JavaThread, _jvmci_counters); } 865 #endif // INCLUDE_JVMCI 866 static ByteSize exception_oop_offset() { return byte_offset_of(JavaThread, _exception_oop); } 867 static ByteSize exception_pc_offset() { return byte_offset_of(JavaThread, _exception_pc); } 868 static ByteSize exception_handler_pc_offset() { return byte_offset_of(JavaThread, _exception_handler_pc); } 869 static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); } 870 871 static ByteSize active_handles_offset() { return byte_offset_of(JavaThread, _active_handles); } 872 873 // StackOverflow offsets 874 static ByteSize stack_overflow_limit_offset() { 875 return byte_offset_of(JavaThread, _stack_overflow_state._stack_overflow_limit); 876 } 877 static ByteSize stack_guard_state_offset() { 878 return byte_offset_of(JavaThread, _stack_overflow_state._stack_guard_state); 879 } 880 static ByteSize reserved_stack_activation_offset() { 881 return byte_offset_of(JavaThread, _stack_overflow_state._reserved_stack_activation); 882 } 883 static ByteSize shadow_zone_safe_limit() { 884 return byte_offset_of(JavaThread, _stack_overflow_state._shadow_zone_safe_limit); 885 } 886 static ByteSize shadow_zone_growth_watermark() { 887 return byte_offset_of(JavaThread, _stack_overflow_state._shadow_zone_growth_watermark); 888 } 889 890 static ByteSize suspend_flags_offset() { return byte_offset_of(JavaThread, _suspend_flags); } 891 892 static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); } 893 static ByteSize should_post_on_exceptions_flag_offset() { 894 return byte_offset_of(JavaThread, _should_post_on_exceptions_flag); 895 } 896 static ByteSize doing_unsafe_access_offset() { return byte_offset_of(JavaThread, _doing_unsafe_access); } 897 NOT_PRODUCT(static ByteSize requires_cross_modify_fence_offset() { return byte_offset_of(JavaThread, _requires_cross_modify_fence); }) 898 899 static ByteSize lock_id_offset() { return byte_offset_of(JavaThread, _lock_id); } 900 901 static ByteSize cont_entry_offset() { return byte_offset_of(JavaThread, _cont_entry); } 902 static ByteSize cont_fastpath_offset() { return byte_offset_of(JavaThread, _cont_fastpath); } 903 static ByteSize held_monitor_count_offset() { return byte_offset_of(JavaThread, _held_monitor_count); } 904 static ByteSize jni_monitor_count_offset() { return byte_offset_of(JavaThread, _jni_monitor_count); } 905 static ByteSize preemption_cancelled_offset() { return byte_offset_of(JavaThread, _preemption_cancelled); } 906 static ByteSize preempt_alternate_return_offset() { return byte_offset_of(JavaThread, _preempt_alternate_return); } 907 static ByteSize unlocked_inflated_monitor_offset() { return byte_offset_of(JavaThread, _unlocked_inflated_monitor); } 908 909 #if INCLUDE_JVMTI 910 static ByteSize is_in_VTMS_transition_offset() { return byte_offset_of(JavaThread, _is_in_VTMS_transition); } 911 static ByteSize is_in_tmp_VTMS_transition_offset() { return byte_offset_of(JavaThread, _is_in_tmp_VTMS_transition); } 912 static ByteSize is_disable_suspend_offset() { return byte_offset_of(JavaThread, _is_disable_suspend); } 913 #endif 914 915 // Returns the jni environment for this thread 916 JNIEnv* jni_environment() { return &_jni_environment; } 917 918 // Returns the current thread as indicated by the given JNIEnv. 919 // We don't assert it is Thread::current here as that is done at the 920 // external JNI entry points where the JNIEnv is passed into the VM. 921 static JavaThread* thread_from_jni_environment(JNIEnv* env) { 922 JavaThread* current = reinterpret_cast<JavaThread*>(((intptr_t)env - in_bytes(jni_environment_offset()))); 923 // We can't normally get here in a thread that has completed its 924 // execution and so "is_terminated", except when the call is from 925 // AsyncGetCallTrace, which can be triggered by a signal at any point in 926 // a thread's lifecycle. A thread is also considered terminated if the VM 927 // has exited, so we have to check this and block in case this is a daemon 928 // thread returning to the VM (the JNI DirectBuffer entry points rely on 929 // this). 930 if (current->is_terminated()) { 931 current->block_if_vm_exited(); 932 } 933 return current; 934 } 935 936 // JNI critical regions. These can nest. 937 bool in_critical() { return _jni_active_critical > 0; } 938 bool in_last_critical() { return _jni_active_critical == 1; } 939 inline void enter_critical(); 940 void exit_critical() { 941 assert(Thread::current() == this, "this must be current thread"); 942 _jni_active_critical--; 943 assert(_jni_active_critical >= 0, "JNI critical nesting problem?"); 944 } 945 946 // Checked JNI: is the programmer required to check for exceptions, if so specify 947 // which function name. Returning to a Java frame should implicitly clear the 948 // pending check, this is done for Native->Java transitions (i.e. user JNI code). 949 // VM->Java transitions are not cleared, it is expected that JNI code enclosed 950 // within ThreadToNativeFromVM makes proper exception checks (i.e. VM internal). 951 bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != nullptr; } 952 void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = nullptr; } 953 const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; } 954 void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; } 955 956 // For deadlock detection 957 int depth_first_number() { return _depth_first_number; } 958 void set_depth_first_number(int dfn) { _depth_first_number = dfn; } 959 960 public: 961 bool in_deopt_handler() const { return _in_deopt_handler > 0; } 962 void inc_in_deopt_handler() { _in_deopt_handler++; } 963 void dec_in_deopt_handler() { 964 assert(_in_deopt_handler > 0, "mismatched deopt nesting"); 965 if (_in_deopt_handler > 0) { // robustness 966 _in_deopt_handler--; 967 } 968 } 969 970 private: 971 void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; } 972 973 // factor out low-level mechanics for use in both normal and error cases 974 const char* get_thread_name_string(char* buf = nullptr, int buflen = 0) const; 975 976 public: 977 978 // Frame iteration; calls the function f for all frames on the stack 979 void frames_do(void f(frame*, const RegisterMap*)); 980 981 // Memory operations 982 void oops_do_frames(OopClosure* f, NMethodClosure* cf); 983 void oops_do_no_frames(OopClosure* f, NMethodClosure* cf); 984 985 // GC operations 986 virtual void nmethods_do(NMethodClosure* cf); 987 988 // RedefineClasses Support 989 void metadata_do(MetadataClosure* f); 990 991 // Debug method asserting thread states are correct during a handshake operation. 992 DEBUG_ONLY(void verify_states_for_handshake();) 993 994 // Misc. operations 995 const char* name() const; 996 const char* name_raw() const; 997 const char* type_name() const { return "JavaThread"; } 998 static const char* name_for(oop thread_obj); 999 1000 void print_on(outputStream* st, bool print_extended_info) const; 1001 void print_on(outputStream* st) const { print_on(st, false); } 1002 void print() const; 1003 void print_thread_state_on(outputStream*) const; 1004 void print_on_error(outputStream* st, char* buf, int buflen) const; 1005 void print_name_on_error(outputStream* st, char* buf, int buflen) const; 1006 void verify(); 1007 1008 // Accessing frames 1009 frame last_frame() { 1010 _anchor.make_walkable(); 1011 return pd_last_frame(); 1012 } 1013 javaVFrame* last_java_vframe(RegisterMap* reg_map) { return last_java_vframe(last_frame(), reg_map); } 1014 1015 frame carrier_last_frame(RegisterMap* reg_map); 1016 javaVFrame* carrier_last_java_vframe(RegisterMap* reg_map) { return last_java_vframe(carrier_last_frame(reg_map), reg_map); } 1017 1018 frame vthread_last_frame(); 1019 javaVFrame* vthread_last_java_vframe(RegisterMap* reg_map) { return last_java_vframe(vthread_last_frame(), reg_map); } 1020 1021 frame platform_thread_last_frame(RegisterMap* reg_map); 1022 javaVFrame* platform_thread_last_java_vframe(RegisterMap* reg_map) { 1023 return last_java_vframe(platform_thread_last_frame(reg_map), reg_map); 1024 } 1025 1026 javaVFrame* last_java_vframe(const frame f, RegisterMap* reg_map); 1027 1028 // Returns method at 'depth' java or native frames down the stack 1029 // Used for security checks 1030 Klass* security_get_caller_class(int depth); 1031 1032 // Print stack trace in external format 1033 // These variants print carrier/platform thread information only. 1034 void print_stack_on(outputStream* st); 1035 void print_stack() { print_stack_on(tty); } 1036 // This prints the currently mounted virtual thread. 1037 void print_vthread_stack_on(outputStream* st); 1038 // This prints the active stack: either carrier/platform or virtual. 1039 void print_active_stack_on(outputStream* st); 1040 // Print current stack trace for checked JNI warnings and JNI fatal errors. 1041 // This is the external format from above, but selecting the platform 1042 // or vthread as applicable. 1043 void print_jni_stack(); 1044 1045 // Print stack traces in various internal formats 1046 void trace_stack() PRODUCT_RETURN; 1047 void trace_stack_from(vframe* start_vf) PRODUCT_RETURN; 1048 void trace_frames() PRODUCT_RETURN; 1049 1050 // Print an annotated view of the stack frames 1051 void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN; 1052 void validate_frame_layout() { 1053 print_frame_layout(0, true); 1054 } 1055 1056 // Function for testing deoptimization 1057 void deoptimize(); 1058 void make_zombies(); 1059 1060 void deoptimize_marked_methods(); 1061 1062 public: 1063 // Returns the running thread as a JavaThread 1064 static JavaThread* current() { 1065 return JavaThread::cast(Thread::current()); 1066 } 1067 1068 // Returns the current thread as a JavaThread, or nullptr if not attached 1069 static inline JavaThread* current_or_null(); 1070 1071 // Casts 1072 static JavaThread* cast(Thread* t) { 1073 assert(t->is_Java_thread(), "incorrect cast to JavaThread"); 1074 return static_cast<JavaThread*>(t); 1075 } 1076 1077 static const JavaThread* cast(const Thread* t) { 1078 assert(t->is_Java_thread(), "incorrect cast to const JavaThread"); 1079 return static_cast<const JavaThread*>(t); 1080 } 1081 1082 // Returns the active Java thread. Do not use this if you know you are calling 1083 // from a JavaThread, as it's slower than JavaThread::current. If called from 1084 // the VMThread, it also returns the JavaThread that instigated the VMThread's 1085 // operation. You may not want that either. 1086 static JavaThread* active(); 1087 1088 protected: 1089 virtual void pre_run(); 1090 virtual void run(); 1091 void thread_main_inner(); 1092 virtual void post_run(); 1093 1094 public: 1095 // Thread local information maintained by JVMTI. 1096 void set_jvmti_thread_state(JvmtiThreadState *value) { _jvmti_thread_state = value; } 1097 // A JvmtiThreadState is lazily allocated. This jvmti_thread_state() 1098 // getter is used to get this JavaThread's JvmtiThreadState if it has 1099 // one which means null can be returned. JvmtiThreadState::state_for() 1100 // is used to get the specified JavaThread's JvmtiThreadState if it has 1101 // one or it allocates a new JvmtiThreadState for the JavaThread and 1102 // returns it. JvmtiThreadState::state_for() will return null only if 1103 // the specified JavaThread is exiting. 1104 JvmtiThreadState *jvmti_thread_state() const { return _jvmti_thread_state; } 1105 static ByteSize jvmti_thread_state_offset() { return byte_offset_of(JavaThread, _jvmti_thread_state); } 1106 1107 #if INCLUDE_JVMTI 1108 // Rebind JVMTI thread state from carrier to virtual or from virtual to carrier. 1109 JvmtiThreadState *rebind_to_jvmti_thread_state_of(oop thread_oop); 1110 #endif 1111 1112 // JVMTI PopFrame support 1113 // Setting and clearing popframe_condition 1114 // All of these enumerated values are bits. popframe_pending 1115 // indicates that a PopFrame() has been requested and not yet been 1116 // completed. popframe_processing indicates that that PopFrame() is in 1117 // the process of being completed. popframe_force_deopt_reexecution_bit 1118 // indicates that special handling is required when returning to a 1119 // deoptimized caller. 1120 enum PopCondition { 1121 popframe_inactive = 0x00, 1122 popframe_pending_bit = 0x01, 1123 popframe_processing_bit = 0x02, 1124 popframe_force_deopt_reexecution_bit = 0x04 1125 }; 1126 PopCondition popframe_condition() { return (PopCondition) _popframe_condition; } 1127 void set_popframe_condition(PopCondition c) { _popframe_condition = c; } 1128 void set_popframe_condition_bit(PopCondition c) { _popframe_condition |= c; } 1129 void clear_popframe_condition() { _popframe_condition = popframe_inactive; } 1130 static ByteSize popframe_condition_offset() { return byte_offset_of(JavaThread, _popframe_condition); } 1131 bool has_pending_popframe() { return (popframe_condition() & popframe_pending_bit) != 0; } 1132 bool popframe_forcing_deopt_reexecution() { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; } 1133 1134 bool pop_frame_in_process(void) { return ((_popframe_condition & popframe_processing_bit) != 0); } 1135 void set_pop_frame_in_process(void) { _popframe_condition |= popframe_processing_bit; } 1136 void clr_pop_frame_in_process(void) { _popframe_condition &= ~popframe_processing_bit; } 1137 1138 int frames_to_pop_failed_realloc() const { return _frames_to_pop_failed_realloc; } 1139 void set_frames_to_pop_failed_realloc(int nb) { _frames_to_pop_failed_realloc = nb; } 1140 void dec_frames_to_pop_failed_realloc() { _frames_to_pop_failed_realloc--; } 1141 1142 private: 1143 // Saved incoming arguments to popped frame. 1144 // Used only when popped interpreted frame returns to deoptimized frame. 1145 void* _popframe_preserved_args; 1146 int _popframe_preserved_args_size; 1147 1148 public: 1149 void popframe_preserve_args(ByteSize size_in_bytes, void* start); 1150 void* popframe_preserved_args(); 1151 ByteSize popframe_preserved_args_size(); 1152 WordSize popframe_preserved_args_size_in_words(); 1153 void popframe_free_preserved_args(); 1154 1155 1156 private: 1157 JvmtiThreadState *_jvmti_thread_state; 1158 1159 // Used by the interpreter in fullspeed mode for frame pop, method 1160 // entry, method exit and single stepping support. This field is 1161 // only set to non-zero at a safepoint or using a direct handshake 1162 // (see EnterInterpOnlyModeClosure). 1163 // It can be set to zero asynchronously to this threads execution (i.e., without 1164 // safepoint/handshake or a lock) so we have to be very careful. 1165 // Accesses by other threads are synchronized using JvmtiThreadState_lock though. 1166 int _interp_only_mode; 1167 1168 public: 1169 // used by the interpreter for fullspeed debugging support (see above) 1170 static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); } 1171 bool is_interp_only_mode() { return (_interp_only_mode != 0); } 1172 int get_interp_only_mode() { return _interp_only_mode; } 1173 int set_interp_only_mode(int val) { return _interp_only_mode = val; } 1174 void increment_interp_only_mode() { ++_interp_only_mode; } 1175 void decrement_interp_only_mode() { --_interp_only_mode; } 1176 1177 // support for cached flag that indicates whether exceptions need to be posted for this thread 1178 // if this is false, we can avoid deoptimizing when events are thrown 1179 // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything 1180 private: 1181 int _should_post_on_exceptions_flag; 1182 1183 public: 1184 void set_should_post_on_exceptions_flag(int val) { _should_post_on_exceptions_flag = val; } 1185 1186 private: 1187 ThreadStatistics *_thread_stat; 1188 1189 public: 1190 ThreadStatistics* get_thread_stat() const { return _thread_stat; } 1191 1192 // Return a blocker object for which this thread is blocked parking. 1193 oop current_park_blocker(); 1194 1195 private: 1196 static size_t _stack_size_at_create; 1197 1198 public: 1199 static inline size_t stack_size_at_create(void) { 1200 return _stack_size_at_create; 1201 } 1202 static inline void set_stack_size_at_create(size_t value) { 1203 _stack_size_at_create = value; 1204 } 1205 1206 // Machine dependent stuff 1207 #include OS_CPU_HEADER(javaThread) 1208 1209 // JSR166 per-thread parker 1210 private: 1211 Parker _parker; 1212 public: 1213 Parker* parker() { return &_parker; } 1214 1215 public: 1216 // clearing/querying jni attach status 1217 bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; } 1218 bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; } 1219 inline void set_done_attaching_via_jni(); 1220 1221 // Stack dump assistance: 1222 // Track the class we want to initialize but for which we have to wait 1223 // on its init_lock() because it is already being initialized. 1224 void set_class_to_be_initialized(InstanceKlass* k); 1225 InstanceKlass* class_to_be_initialized() const; 1226 1227 // Track executing class initializer, see ThreadInClassInitializer 1228 void set_class_being_initialized(InstanceKlass* k); 1229 InstanceKlass* class_being_initialized() const; 1230 1231 private: 1232 InstanceKlass* _class_to_be_initialized; 1233 InstanceKlass* _class_being_initialized; 1234 1235 // java.lang.Thread.sleep support 1236 ParkEvent * _SleepEvent; 1237 1238 #if INCLUDE_JFR 1239 // Support for jdk.VirtualThreadPinned event 1240 Ticks _pinned_start_time; 1241 #endif 1242 1243 public: 1244 bool sleep(jlong millis); 1245 bool sleep_nanos(jlong nanos); 1246 1247 // java.lang.Thread interruption support 1248 void interrupt(); 1249 bool is_interrupted(bool clear_interrupted); 1250 1251 #if INCLUDE_JFR 1252 Ticks& vthread_pinned_start_time() { return _pinned_start_time; } 1253 void start_vthread_pinned() { _pinned_start_time = Ticks::now(); } 1254 void post_vthread_pinned_event(EventVirtualThreadPinned* event, const char* reason); 1255 #endif 1256 1257 // This is only for use by JVMTI RawMonitorWait. It emulates the actions of 1258 // the Java code in Object::wait which are not present in RawMonitorWait. 1259 bool get_and_clear_interrupted(); 1260 1261 private: 1262 LockStack _lock_stack; 1263 OMCache _om_cache; 1264 1265 public: 1266 LockStack& lock_stack() { return _lock_stack; } 1267 1268 static ByteSize lock_stack_offset() { return byte_offset_of(JavaThread, _lock_stack); } 1269 // Those offsets are used in code generators to access the LockStack that is embedded in this 1270 // JavaThread structure. Those accesses are relative to the current thread, which 1271 // is typically in a dedicated register. 1272 static ByteSize lock_stack_top_offset() { return lock_stack_offset() + LockStack::top_offset(); } 1273 static ByteSize lock_stack_base_offset() { return lock_stack_offset() + LockStack::base_offset(); } 1274 1275 static ByteSize om_cache_offset() { return byte_offset_of(JavaThread, _om_cache); } 1276 static ByteSize om_cache_oops_offset() { return om_cache_offset() + OMCache::entries_offset(); } 1277 1278 void om_set_monitor_cache(ObjectMonitor* monitor); 1279 void om_clear_monitor_cache(); 1280 ObjectMonitor* om_get_from_monitor_cache(oop obj); 1281 1282 static OopStorage* thread_oop_storage(); 1283 1284 static void verify_cross_modify_fence_failure(JavaThread *thread) PRODUCT_RETURN; 1285 1286 // Helper function to create the java.lang.Thread object for a 1287 // VM-internal thread. The thread will have the given name and be 1288 // part of the System ThreadGroup. 1289 static Handle create_system_thread_object(const char* name, TRAPS); 1290 1291 // Helper function to start a VM-internal daemon thread. 1292 // E.g. ServiceThread, NotificationThread, CompilerThread etc. 1293 static void start_internal_daemon(JavaThread* current, JavaThread* target, 1294 Handle thread_oop, ThreadPriority prio); 1295 1296 // Helper function to do vm_exit_on_initialization for osthread 1297 // resource allocation failure. 1298 static void vm_exit_on_osthread_failure(JavaThread* thread); 1299 1300 // Deferred OopHandle release support 1301 private: 1302 // List of OopHandles to be released - guarded by the Service_lock. 1303 static OopHandleList* _oop_handle_list; 1304 // Add our OopHandles to the list for the service thread to release. 1305 void add_oop_handles_for_release(); 1306 // Called by the ServiceThread to release the OopHandles. 1307 static void release_oop_handles(); 1308 // Called by the ServiceThread to poll if there are any OopHandles to release. 1309 // Called when holding the Service_lock. 1310 static bool has_oop_handles_to_release() { 1311 return _oop_handle_list != nullptr; 1312 } 1313 }; 1314 1315 inline JavaThread* JavaThread::current_or_null() { 1316 Thread* current = Thread::current_or_null(); 1317 return current != nullptr ? JavaThread::cast(current) : nullptr; 1318 } 1319 1320 class UnlockFlagSaver { 1321 private: 1322 JavaThread* _thread; 1323 bool _do_not_unlock; 1324 public: 1325 UnlockFlagSaver(JavaThread* t) { 1326 _thread = t; 1327 _do_not_unlock = t->do_not_unlock_if_synchronized(); 1328 t->set_do_not_unlock_if_synchronized(false); 1329 } 1330 ~UnlockFlagSaver() { 1331 _thread->set_do_not_unlock_if_synchronized(_do_not_unlock); 1332 } 1333 }; 1334 1335 class JNIHandleMark : public StackObj { 1336 JavaThread* _thread; 1337 public: 1338 JNIHandleMark(JavaThread* thread) : _thread(thread) { 1339 thread->push_jni_handle_block(); 1340 } 1341 ~JNIHandleMark() { _thread->pop_jni_handle_block(); } 1342 }; 1343 1344 class NoPreemptMark { 1345 ContinuationEntry* _ce; 1346 bool _unpin; 1347 public: 1348 NoPreemptMark(JavaThread* thread) : _ce(thread->last_continuation()), _unpin(false) { 1349 if (_ce != nullptr) _unpin = _ce->pin(); 1350 } 1351 ~NoPreemptMark() { if (_unpin) _ce->unpin(); } 1352 }; 1353 1354 class ThreadOnMonitorWaitedEvent { 1355 JavaThread* _thread; 1356 public: 1357 ThreadOnMonitorWaitedEvent(JavaThread* thread) : _thread(thread) { 1358 JVMTI_ONLY(_thread->set_on_monitor_waited_event(true);) 1359 } 1360 ~ThreadOnMonitorWaitedEvent() { JVMTI_ONLY(_thread->set_on_monitor_waited_event(false);) } 1361 }; 1362 1363 class ThreadInClassInitializer : public StackObj { 1364 InstanceKlass* _previous; 1365 public: 1366 ThreadInClassInitializer(InstanceKlass* ik) { 1367 JavaThread* current = JavaThread::current(); 1368 _previous = current->class_being_initialized(); 1369 current->set_class_being_initialized(ik); 1370 } 1371 ~ThreadInClassInitializer() { 1372 JavaThread* current = JavaThread::current(); 1373 current->set_class_being_initialized(_previous); 1374 } 1375 }; 1376 1377 #endif // SHARE_RUNTIME_JAVATHREAD_HPP