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