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