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