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