1 /*
   2  * Copyright (c) 1997, 2021, 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_THREAD_HPP
  27 #define SHARE_RUNTIME_THREAD_HPP
  28 
  29 #include "jni.h"
  30 #include "gc/shared/gcThreadLocalData.hpp"
  31 #include "gc/shared/threadLocalAllocBuffer.hpp"
  32 #include "memory/allocation.hpp"
  33 #include "oops/oop.hpp"
  34 #include "oops/oopHandle.hpp"
  35 #include "runtime/frame.hpp"
  36 #include "runtime/globals.hpp"
  37 #include "runtime/handshake.hpp"
  38 #include "runtime/javaFrameAnchor.hpp"
  39 #include "runtime/lockStack.hpp"
  40 #include "runtime/mutexLocker.hpp"
  41 #include "runtime/os.hpp"
  42 #include "runtime/park.hpp"
  43 #include "runtime/safepointMechanism.hpp"
  44 #include "runtime/stackWatermarkSet.hpp"
  45 #include "runtime/stackOverflow.hpp"
  46 #include "runtime/threadHeapSampler.hpp"
  47 #include "runtime/threadLocalStorage.hpp"
  48 #include "runtime/threadStatisticalInfo.hpp"
  49 #include "runtime/unhandledOops.hpp"
  50 #include "utilities/align.hpp"
  51 #include "utilities/exceptions.hpp"
  52 #include "utilities/globalDefinitions.hpp"
  53 #include "utilities/macros.hpp"
  54 #if INCLUDE_JFR
  55 #include "jfr/support/jfrThreadExtension.hpp"
  56 #endif
  57 
  58 
  59 class SafeThreadsListPtr;
  60 class ThreadSafepointState;
  61 class ThreadsList;
  62 class ThreadsSMRSupport;
  63 
  64 class JNIHandleBlock;
  65 class JvmtiRawMonitor;
  66 class JvmtiSampledObjectAllocEventCollector;
  67 class JvmtiThreadState;
  68 class JvmtiVMObjectAllocEventCollector;
  69 class OSThread;
  70 class ThreadStatistics;
  71 class ConcurrentLocksDump;
  72 class MonitorInfo;
  73 
  74 class vframeArray;
  75 class vframe;
  76 class javaVFrame;
  77 
  78 class DeoptResourceMark;
  79 class JvmtiDeferredUpdates;
  80 
  81 class ThreadClosure;
  82 class ICRefillVerifier;
  83 
  84 class Metadata;
  85 class ResourceArea;
  86 
  87 class OopStorage;
  88 
  89 DEBUG_ONLY(class ResourceMark;)
  90 
  91 class WorkerThread;
  92 
  93 class JavaThread;
  94 
  95 // Class hierarchy
  96 // - Thread
  97 //   - JavaThread
  98 //     - various subclasses eg CompilerThread, ServiceThread
  99 //   - NonJavaThread
 100 //     - NamedThread
 101 //       - VMThread
 102 //       - ConcurrentGCThread
 103 //       - WorkerThread
 104 //         - GangWorker
 105 //     - WatcherThread
 106 //     - JfrThreadSampler
 107 //     - LogAsyncWriter
 108 //
 109 // All Thread subclasses must be either JavaThread or NonJavaThread.
 110 // This means !t->is_Java_thread() iff t is a NonJavaThread, or t is
 111 // a partially constructed/destroyed Thread.
 112 
 113 // Thread execution sequence and actions:
 114 // All threads:
 115 //  - thread_native_entry  // per-OS native entry point
 116 //    - stack initialization
 117 //    - other OS-level initialization (signal masks etc)
 118 //    - handshake with creating thread (if not started suspended)
 119 //    - this->call_run()  // common shared entry point
 120 //      - shared common initialization
 121 //      - this->pre_run()  // virtual per-thread-type initialization
 122 //      - this->run()      // virtual per-thread-type "main" logic
 123 //      - shared common tear-down
 124 //      - this->post_run()  // virtual per-thread-type tear-down
 125 //      - // 'this' no longer referenceable
 126 //    - OS-level tear-down (minimal)
 127 //    - final logging
 128 //
 129 // For JavaThread:
 130 //   - this->run()  // virtual but not normally overridden
 131 //     - this->thread_main_inner()  // extra call level to ensure correct stack calculations
 132 //       - this->entry_point()  // set differently for each kind of JavaThread
 133 
 134 class Thread: public ThreadShadow {
 135   friend class VMStructs;
 136   friend class JVMCIVMStructs;
 137  private:
 138 
 139 #ifndef USE_LIBRARY_BASED_TLS_ONLY
 140   // Current thread is maintained as a thread-local variable
 141   static THREAD_LOCAL Thread* _thr_current;
 142 #endif
 143 
 144   // Thread local data area available to the GC. The internal
 145   // structure and contents of this data area is GC-specific.
 146   // Only GC and GC barrier code should access this data area.
 147   GCThreadLocalData _gc_data;
 148 
 149  public:
 150   static ByteSize gc_data_offset() {
 151     return byte_offset_of(Thread, _gc_data);
 152   }
 153 
 154   template <typename T> T* gc_data() {
 155     STATIC_ASSERT(sizeof(T) <= sizeof(_gc_data));
 156     return reinterpret_cast<T*>(&_gc_data);
 157   }
 158 
 159   // Exception handling
 160   // (Note: _pending_exception and friends are in ThreadShadow)
 161   //oop       _pending_exception;                // pending exception for current thread
 162   // const char* _exception_file;                   // file information for exception (debugging only)
 163   // int         _exception_line;                   // line information for exception (debugging only)
 164  protected:
 165 
 166   DEBUG_ONLY(static Thread* _starting_thread;)
 167 
 168   // Support for forcing alignment of thread objects for biased locking
 169   void*       _real_malloc_address;
 170 
 171   // JavaThread lifecycle support:
 172   friend class SafeThreadsListPtr;  // for _threads_list_ptr, cmpxchg_threads_hazard_ptr(), {dec_,inc_,}nested_threads_hazard_ptr_cnt(), {g,s}et_threads_hazard_ptr(), inc_nested_handle_cnt(), tag_hazard_ptr() access
 173   friend class ScanHazardPtrGatherProtectedThreadsClosure;  // for cmpxchg_threads_hazard_ptr(), get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
 174   friend class ScanHazardPtrGatherThreadsListClosure;  // for get_threads_hazard_ptr(), untag_hazard_ptr() access
 175   friend class ScanHazardPtrPrintMatchingThreadsClosure;  // for get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
 176   friend class ThreadsSMRSupport;  // for _nested_threads_hazard_ptr_cnt, _threads_hazard_ptr, _threads_list_ptr access
 177   friend class ThreadsListHandleTest;  // for _nested_threads_hazard_ptr_cnt, _threads_hazard_ptr, _threads_list_ptr access
 178   friend class ValidateHazardPtrsClosure;  // for get_threads_hazard_ptr(), untag_hazard_ptr() access
 179 
 180   ThreadsList* volatile _threads_hazard_ptr;
 181   SafeThreadsListPtr*   _threads_list_ptr;
 182   ThreadsList*          cmpxchg_threads_hazard_ptr(ThreadsList* exchange_value, ThreadsList* compare_value);
 183   ThreadsList*          get_threads_hazard_ptr() const;
 184   void                  set_threads_hazard_ptr(ThreadsList* new_list);
 185   static bool           is_hazard_ptr_tagged(ThreadsList* list) {
 186     return (intptr_t(list) & intptr_t(1)) == intptr_t(1);
 187   }
 188   static ThreadsList*   tag_hazard_ptr(ThreadsList* list) {
 189     return (ThreadsList*)(intptr_t(list) | intptr_t(1));
 190   }
 191   static ThreadsList*   untag_hazard_ptr(ThreadsList* list) {
 192     return (ThreadsList*)(intptr_t(list) & ~intptr_t(1));
 193   }
 194   // This field is enabled via -XX:+EnableThreadSMRStatistics:
 195   uint _nested_threads_hazard_ptr_cnt;
 196   void dec_nested_threads_hazard_ptr_cnt() {
 197     assert(_nested_threads_hazard_ptr_cnt != 0, "mismatched {dec,inc}_nested_threads_hazard_ptr_cnt()");
 198     _nested_threads_hazard_ptr_cnt--;
 199   }
 200   void inc_nested_threads_hazard_ptr_cnt() {
 201     _nested_threads_hazard_ptr_cnt++;
 202   }
 203   uint nested_threads_hazard_ptr_cnt() {
 204     return _nested_threads_hazard_ptr_cnt;
 205   }
 206 
 207  public:
 208   // Is the target JavaThread protected by the calling Thread
 209   // or by some other mechanism:
 210   static bool is_JavaThread_protected(const JavaThread* p);
 211 
 212   void* operator new(size_t size) throw() { return allocate(size, true); }
 213   void* operator new(size_t size, const std::nothrow_t& nothrow_constant) throw() {
 214     return allocate(size, false); }
 215   void  operator delete(void* p);
 216 
 217  protected:
 218   static void* allocate(size_t size, bool throw_excpt, MEMFLAGS flags = mtThread);
 219 
 220  private:
 221   DEBUG_ONLY(bool _suspendible_thread;)
 222 
 223  public:
 224   // Determines if a heap allocation failure will be retried
 225   // (e.g., by deoptimizing and re-executing in the interpreter).
 226   // In this case, the failed allocation must raise
 227   // Universe::out_of_memory_error_retry() and omit side effects
 228   // such as JVMTI events and handling -XX:+HeapDumpOnOutOfMemoryError
 229   // and -XX:OnOutOfMemoryError.
 230   virtual bool in_retryable_allocation() const { return false; }
 231 
 232 #ifdef ASSERT
 233   void set_suspendible_thread() {
 234     _suspendible_thread = true;
 235   }
 236 
 237   void clear_suspendible_thread() {
 238     _suspendible_thread = false;
 239   }
 240 
 241   bool is_suspendible_thread() { return _suspendible_thread; }
 242 #endif
 243 
 244  private:
 245   // Active_handles points to a block of handles
 246   JNIHandleBlock* _active_handles;
 247 
 248   // One-element thread local free list
 249   JNIHandleBlock* _free_handle_block;
 250 
 251   // Point to the last handle mark
 252   HandleMark* _last_handle_mark;
 253 
 254   // Claim value for parallel iteration over threads.
 255   uintx _threads_do_token;
 256 
 257   // Support for GlobalCounter
 258  private:
 259   volatile uintx _rcu_counter;
 260  public:
 261   volatile uintx* get_rcu_counter() {
 262     return &_rcu_counter;
 263   }
 264 
 265  public:
 266   void set_last_handle_mark(HandleMark* mark)   { _last_handle_mark = mark; }
 267   HandleMark* last_handle_mark() const          { return _last_handle_mark; }
 268  private:
 269 
 270 #ifdef ASSERT
 271   ICRefillVerifier* _missed_ic_stub_refill_verifier;
 272 
 273  public:
 274   ICRefillVerifier* missed_ic_stub_refill_verifier() {
 275     return _missed_ic_stub_refill_verifier;
 276   }
 277 
 278   void set_missed_ic_stub_refill_verifier(ICRefillVerifier* verifier) {
 279     _missed_ic_stub_refill_verifier = verifier;
 280   }
 281 #endif // ASSERT
 282 
 283  private:
 284   // Used by SkipGCALot class.
 285   NOT_PRODUCT(bool _skip_gcalot;)               // Should we elide gc-a-lot?
 286 
 287   friend class GCLocker;
 288 
 289  private:
 290   ThreadLocalAllocBuffer _tlab;                 // Thread-local eden
 291   jlong _allocated_bytes;                       // Cumulative number of bytes allocated on
 292                                                 // the Java heap
 293   ThreadHeapSampler _heap_sampler;              // For use when sampling the memory.
 294 
 295   ThreadStatisticalInfo _statistical_info;      // Statistics about the thread
 296 
 297   JFR_ONLY(DEFINE_THREAD_LOCAL_FIELD_JFR;)      // Thread-local data for jfr
 298 
 299   JvmtiRawMonitor* _current_pending_raw_monitor; // JvmtiRawMonitor this thread
 300                                                  // is waiting to lock
 301  public:
 302   // Constructor
 303   Thread();
 304   virtual ~Thread() = 0;        // Thread is abstract.
 305 
 306   // Manage Thread::current()
 307   void initialize_thread_current();
 308   static void clear_thread_current(); // TLS cleanup needed before threads terminate
 309 
 310  protected:
 311   // To be implemented by children.
 312   virtual void run() = 0;
 313   virtual void pre_run() = 0;
 314   virtual void post_run() = 0;  // Note: Thread must not be deleted prior to calling this!
 315 
 316 #ifdef ASSERT
 317   enum RunState {
 318     PRE_CALL_RUN,
 319     CALL_RUN,
 320     PRE_RUN,
 321     RUN,
 322     POST_RUN
 323     // POST_CALL_RUN - can't define this one as 'this' may be deleted when we want to set it
 324   };
 325   RunState _run_state;  // for lifecycle checks
 326 #endif
 327 
 328 
 329  public:
 330   // invokes <ChildThreadClass>::run(), with common preparations and cleanups.
 331   void call_run();
 332 
 333   // Testers
 334   virtual bool is_VM_thread()       const            { return false; }
 335   virtual bool is_Java_thread()     const            { return false; }
 336   virtual bool is_Compiler_thread() const            { return false; }
 337   virtual bool is_Code_cache_sweeper_thread() const  { return false; }
 338   virtual bool is_service_thread() const             { return false; }
 339   virtual bool is_monitor_deflation_thread() const   { return false; }
 340   virtual bool is_hidden_from_external_view() const  { return false; }
 341   virtual bool is_jvmti_agent_thread() const         { return false; }
 342   // True iff the thread can perform GC operations at a safepoint.
 343   // Generally will be true only of VM thread and parallel GC WorkGang
 344   // threads.
 345   virtual bool is_GC_task_thread() const             { return false; }
 346   virtual bool is_Watcher_thread() const             { return false; }
 347   virtual bool is_ConcurrentGC_thread() const        { return false; }
 348   virtual bool is_Named_thread() const               { return false; }
 349   virtual bool is_Worker_thread() const              { return false; }
 350   virtual bool is_JfrSampler_thread() const          { return false; }
 351 
 352   // Can this thread make Java upcalls
 353   virtual bool can_call_java() const                 { return false; }
 354 
 355   // Is this a JavaThread that is on the VM's current ThreadsList?
 356   // If so it must participate in the safepoint protocol.
 357   virtual bool is_active_Java_thread() const         { return false; }
 358 
 359   // Casts
 360   inline JavaThread* as_Java_thread();
 361   inline const JavaThread* as_Java_thread() const;
 362 
 363   virtual char* name() const { return (char*)"Unknown thread"; }
 364 
 365   // Returns the current thread (ASSERTS if NULL)
 366   static inline Thread* current();
 367   // Returns the current thread, or NULL if not attached
 368   static inline Thread* current_or_null();
 369   // Returns the current thread, or NULL if not attached, and is
 370   // safe for use from signal-handlers
 371   static inline Thread* current_or_null_safe();
 372 
 373   // Common thread operations
 374 #ifdef ASSERT
 375   static void check_for_dangling_thread_pointer(Thread *thread);
 376 #endif
 377   static void set_priority(Thread* thread, ThreadPriority priority);
 378   static ThreadPriority get_priority(const Thread* const thread);
 379   static void start(Thread* thread);
 380 
 381   void set_native_thread_name(const char *name) {
 382     assert(Thread::current() == this, "set_native_thread_name can only be called on the current thread");
 383     os::set_native_thread_name(name);
 384   }
 385 
 386   // Support for Unhandled Oop detection
 387   // Add the field for both, fastdebug and debug, builds to keep
 388   // Thread's fields layout the same.
 389   // Note: CHECK_UNHANDLED_OOPS is defined only for fastdebug build.
 390 #ifdef CHECK_UNHANDLED_OOPS
 391  private:
 392   UnhandledOops* _unhandled_oops;
 393 #elif defined(ASSERT)
 394  private:
 395   void* _unhandled_oops;
 396 #endif
 397 #ifdef CHECK_UNHANDLED_OOPS
 398  public:
 399   UnhandledOops* unhandled_oops() { return _unhandled_oops; }
 400   // Mark oop safe for gc.  It may be stack allocated but won't move.
 401   void allow_unhandled_oop(oop *op) {
 402     if (CheckUnhandledOops) unhandled_oops()->allow_unhandled_oop(op);
 403   }
 404   // Clear oops at safepoint so crashes point to unhandled oop violator
 405   void clear_unhandled_oops() {
 406     if (CheckUnhandledOops) unhandled_oops()->clear_unhandled_oops();
 407   }
 408 #endif // CHECK_UNHANDLED_OOPS
 409 
 410  public:
 411 #ifndef PRODUCT
 412   bool skip_gcalot()           { return _skip_gcalot; }
 413   void set_skip_gcalot(bool v) { _skip_gcalot = v;    }
 414 #endif
 415 
 416   // Resource area
 417   ResourceArea* resource_area() const            { return _resource_area; }
 418   void set_resource_area(ResourceArea* area)     { _resource_area = area; }
 419 
 420   OSThread* osthread() const                     { return _osthread;   }
 421   void set_osthread(OSThread* thread)            { _osthread = thread; }
 422 
 423   // JNI handle support
 424   JNIHandleBlock* active_handles() const         { return _active_handles; }
 425   void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
 426   JNIHandleBlock* free_handle_block() const      { return _free_handle_block; }
 427   void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
 428 
 429   // Internal handle support
 430   HandleArea* handle_area() const                { return _handle_area; }
 431   void set_handle_area(HandleArea* area)         { _handle_area = area; }
 432 
 433   GrowableArray<Metadata*>* metadata_handles() const          { return _metadata_handles; }
 434   void set_metadata_handles(GrowableArray<Metadata*>* handles){ _metadata_handles = handles; }
 435 
 436   // Thread-Local Allocation Buffer (TLAB) support
 437   ThreadLocalAllocBuffer& tlab()                 { return _tlab; }
 438   void initialize_tlab();
 439 
 440   jlong allocated_bytes()               { return _allocated_bytes; }
 441   void set_allocated_bytes(jlong value) { _allocated_bytes = value; }
 442   void incr_allocated_bytes(jlong size) { _allocated_bytes += size; }
 443   inline jlong cooked_allocated_bytes();
 444 
 445   ThreadHeapSampler& heap_sampler()     { return _heap_sampler; }
 446 
 447   ThreadStatisticalInfo& statistical_info() { return _statistical_info; }
 448 
 449   JFR_ONLY(DEFINE_THREAD_LOCAL_ACCESSOR_JFR;)
 450 
 451   // For tracking the Jvmti raw monitor the thread is pending on.
 452   JvmtiRawMonitor* current_pending_raw_monitor() {
 453     return _current_pending_raw_monitor;
 454   }
 455   void set_current_pending_raw_monitor(JvmtiRawMonitor* monitor) {
 456     _current_pending_raw_monitor = monitor;
 457   }
 458 
 459   // GC support
 460   // Apply "f->do_oop" to all root oops in "this".
 461   //   Used by JavaThread::oops_do.
 462   // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames
 463   virtual void oops_do_no_frames(OopClosure* f, CodeBlobClosure* cf);
 464   virtual void oops_do_frames(OopClosure* f, CodeBlobClosure* cf) {}
 465   void oops_do(OopClosure* f, CodeBlobClosure* cf);
 466 
 467   // Handles the parallel case for claim_threads_do.
 468  private:
 469   bool claim_par_threads_do(uintx claim_token);
 470  public:
 471   // Requires that "claim_token" is that of the current iteration.
 472   // If "is_par" is false, sets the token of "this" to
 473   // "claim_token", and returns "true".  If "is_par" is true,
 474   // uses an atomic instruction to set the current thread's token to
 475   // "claim_token", if it is not already.  Returns "true" iff the
 476   // calling thread does the update, this indicates that the calling thread
 477   // has claimed the thread in the current iteration.
 478   bool claim_threads_do(bool is_par, uintx claim_token) {
 479     if (!is_par) {
 480       _threads_do_token = claim_token;
 481       return true;
 482     } else {
 483       return claim_par_threads_do(claim_token);
 484     }
 485   }
 486 
 487   uintx threads_do_token() const { return _threads_do_token; }
 488 
 489   // jvmtiRedefineClasses support
 490   void metadata_handles_do(void f(Metadata*));
 491 
 492  private:
 493   // Check if address is within the given range of this thread's
 494   // stack:  stack_base() > adr >/>= limit
 495   // The check is inclusive of limit if passed true, else exclusive.
 496   bool is_in_stack_range(address adr, address limit, bool inclusive) const {
 497     assert(stack_base() > limit && limit >= stack_end(), "limit is outside of stack");
 498     return stack_base() > adr && (inclusive ? adr >= limit : adr > limit);
 499   }
 500 
 501  public:
 502   // Used by fast lock support
 503   virtual bool is_lock_owned(address adr) const;
 504 
 505   // Check if address is within the given range of this thread's
 506   // stack:  stack_base() > adr >= limit
 507   bool is_in_stack_range_incl(address adr, address limit) const {
 508     return is_in_stack_range(adr, limit, true);
 509   }
 510 
 511   // Check if address is within the given range of this thread's
 512   // stack:  stack_base() > adr > limit
 513   bool is_in_stack_range_excl(address adr, address limit) const {
 514     return is_in_stack_range(adr, limit, false);
 515   }
 516 
 517   // Check if address is in the stack mapped to this thread. Used mainly in
 518   // error reporting (so has to include guard zone) and frame printing.
 519   // Expects _stack_base to be initialized - checked with assert.
 520   bool is_in_full_stack_checked(address adr) const {
 521     return is_in_stack_range_incl(adr, stack_end());
 522   }
 523 
 524   // Like is_in_full_stack_checked but without the assertions as this
 525   // may be called in a thread before _stack_base is initialized.
 526   bool is_in_full_stack(address adr) const {
 527     address stack_end = _stack_base - _stack_size;
 528     return _stack_base > adr && adr >= stack_end;
 529   }
 530 
 531   // Check if address is in the live stack of this thread (not just for locks).
 532   // Warning: can only be called by the current thread on itself.
 533   bool is_in_live_stack(address adr) const {
 534     assert(Thread::current() == this, "is_in_live_stack can only be called from current thread");
 535     return is_in_stack_range_incl(adr, os::current_stack_pointer());
 536   }
 537 
 538   // Sets this thread as starting thread. Returns failure if thread
 539   // creation fails due to lack of memory, too many threads etc.
 540   bool set_as_starting_thread();
 541 
 542 protected:
 543   // OS data associated with the thread
 544   OSThread* _osthread;  // Platform-specific thread information
 545 
 546   // Thread local resource area for temporary allocation within the VM
 547   ResourceArea* _resource_area;
 548 
 549   DEBUG_ONLY(ResourceMark* _current_resource_mark;)
 550 
 551   // Thread local handle area for allocation of handles within the VM
 552   HandleArea* _handle_area;
 553   GrowableArray<Metadata*>* _metadata_handles;
 554 
 555   // Support for stack overflow handling, get_thread, etc.
 556   address          _stack_base;
 557   size_t           _stack_size;
 558   int              _lgrp_id;
 559 
 560  public:
 561   // Stack overflow support
 562   address stack_base() const           { assert(_stack_base != NULL,"Sanity check"); return _stack_base; }
 563   void    set_stack_base(address base) { _stack_base = base; }
 564   size_t  stack_size() const           { return _stack_size; }
 565   void    set_stack_size(size_t size)  { _stack_size = size; }
 566   address stack_end()  const           { return stack_base() - stack_size(); }
 567   void    record_stack_base_and_size();
 568   void    register_thread_stack_with_NMT() NOT_NMT_RETURN;
 569   void    unregister_thread_stack_with_NMT() NOT_NMT_RETURN;
 570 
 571   int     lgrp_id() const        { return _lgrp_id; }
 572   void    set_lgrp_id(int value) { _lgrp_id = value; }
 573 
 574   // Printing
 575   void print_on(outputStream* st, bool print_extended_info) const;
 576   virtual void print_on(outputStream* st) const { print_on(st, false); }
 577   void print() const;
 578   virtual void print_on_error(outputStream* st, char* buf, int buflen) const;
 579   void print_value_on(outputStream* st) const;
 580 
 581   // Debug-only code
 582 #ifdef ASSERT
 583  private:
 584   // Deadlock detection support for Mutex locks. List of locks own by thread.
 585   Mutex* _owned_locks;
 586   // Mutex::set_owner_implementation is the only place where _owned_locks is modified,
 587   // thus the friendship
 588   friend class Mutex;
 589   friend class Monitor;
 590 
 591  public:
 592   void print_owned_locks_on(outputStream* st) const;
 593   void print_owned_locks() const                 { print_owned_locks_on(tty);    }
 594   Mutex* owned_locks() const                     { return _owned_locks;          }
 595   bool owns_locks() const                        { return owned_locks() != NULL; }
 596 
 597   // Deadlock detection
 598   ResourceMark* current_resource_mark()          { return _current_resource_mark; }
 599   void set_current_resource_mark(ResourceMark* rm) { _current_resource_mark = rm; }
 600 #endif // ASSERT
 601 
 602  private:
 603   volatile int _jvmti_env_iteration_count;
 604 
 605  public:
 606   void entering_jvmti_env_iteration()            { ++_jvmti_env_iteration_count; }
 607   void leaving_jvmti_env_iteration()             { --_jvmti_env_iteration_count; }
 608   bool is_inside_jvmti_env_iteration()           { return _jvmti_env_iteration_count > 0; }
 609 
 610   // Code generation
 611   static ByteSize exception_file_offset()        { return byte_offset_of(Thread, _exception_file); }
 612   static ByteSize exception_line_offset()        { return byte_offset_of(Thread, _exception_line); }
 613   static ByteSize active_handles_offset()        { return byte_offset_of(Thread, _active_handles); }
 614 
 615   static ByteSize stack_base_offset()            { return byte_offset_of(Thread, _stack_base); }
 616   static ByteSize stack_size_offset()            { return byte_offset_of(Thread, _stack_size); }
 617 
 618   static ByteSize tlab_start_offset()            { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::start_offset(); }
 619   static ByteSize tlab_end_offset()              { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::end_offset(); }
 620   static ByteSize tlab_top_offset()              { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::top_offset(); }
 621   static ByteSize tlab_pf_top_offset()           { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::pf_top_offset(); }
 622 
 623   static ByteSize allocated_bytes_offset()       { return byte_offset_of(Thread, _allocated_bytes); }
 624 
 625   JFR_ONLY(DEFINE_THREAD_LOCAL_OFFSET_JFR;)
 626 
 627  public:
 628   ParkEvent * volatile _ParkEvent;            // for Object monitors, JVMTI raw monitors,
 629                                               // and ObjectSynchronizer::read_stable_mark
 630 
 631   // Termination indicator used by the signal handler.
 632   // _ParkEvent is just a convenient field we can NULL out after setting the JavaThread termination state
 633   // (which can't itself be read from the signal handler if a signal hits during the Thread destructor).
 634   bool has_terminated()                       { return Atomic::load(&_ParkEvent) == NULL; };
 635 
 636   jint _hashStateW;                           // Marsaglia Shift-XOR thread-local RNG
 637   jint _hashStateX;                           // thread-specific hashCode generator state
 638   jint _hashStateY;
 639   jint _hashStateZ;
 640 
 641   // Low-level leaf-lock primitives used to implement synchronization.
 642   // Not for general synchronization use.
 643   static void SpinAcquire(volatile int * Lock, const char * Name);
 644   static void SpinRelease(volatile int * Lock);
 645 
 646 #if defined(__APPLE__) && defined(AARCH64)
 647  private:
 648   DEBUG_ONLY(bool _wx_init);
 649   WXMode _wx_state;
 650  public:
 651   void init_wx();
 652   WXMode enable_wx(WXMode new_state);
 653 
 654   void assert_wx_state(WXMode expected) {
 655     assert(_wx_state == expected, "wrong state");
 656   }
 657 #endif // __APPLE__ && AARCH64
 658 };
 659 
 660 // Inline implementation of Thread::current()
 661 inline Thread* Thread::current() {
 662   Thread* current = current_or_null();
 663   assert(current != NULL, "Thread::current() called on detached thread");
 664   return current;
 665 }
 666 
 667 inline Thread* Thread::current_or_null() {
 668 #ifndef USE_LIBRARY_BASED_TLS_ONLY
 669   return _thr_current;
 670 #else
 671   if (ThreadLocalStorage::is_initialized()) {
 672     return ThreadLocalStorage::thread();
 673   }
 674   return NULL;
 675 #endif
 676 }
 677 
 678 inline Thread* Thread::current_or_null_safe() {
 679   if (ThreadLocalStorage::is_initialized()) {
 680     return ThreadLocalStorage::thread();
 681   }
 682   return NULL;
 683 }
 684 
 685 class CompilerThread;
 686 
 687 typedef void (*ThreadFunction)(JavaThread*, TRAPS);
 688 
 689 class JavaThread: public Thread {
 690   friend class VMStructs;
 691   friend class JVMCIVMStructs;
 692   friend class WhiteBox;
 693   friend class ThreadsSMRSupport; // to access _threadObj for exiting_threads_oops_do
 694   friend class HandshakeState;
 695  private:
 696   bool           _in_asgct;                      // Is set when this JavaThread is handling ASGCT call
 697   bool           _on_thread_list;                // Is set when this JavaThread is added to the Threads list
 698   OopHandle      _threadObj;                     // The Java level thread object
 699 
 700 #ifdef ASSERT
 701  private:
 702   int _java_call_counter;
 703 
 704  public:
 705   int  java_call_counter()                       { return _java_call_counter; }
 706   void inc_java_call_counter()                   { _java_call_counter++; }
 707   void dec_java_call_counter() {
 708     assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
 709     _java_call_counter--;
 710   }
 711  private:  // restore original namespace restriction
 712 #endif  // ifdef ASSERT
 713 
 714   JavaFrameAnchor _anchor;                       // Encapsulation of current java frame and it state
 715 
 716   ThreadFunction _entry_point;
 717 
 718   JNIEnv        _jni_environment;
 719 
 720   // Deopt support
 721   DeoptResourceMark*  _deopt_mark;               // Holds special ResourceMark for deoptimization
 722 
 723   CompiledMethod*       _deopt_nmethod;         // CompiledMethod that is currently being deoptimized
 724   vframeArray*  _vframe_array_head;              // Holds the heap of the active vframeArrays
 725   vframeArray*  _vframe_array_last;              // Holds last vFrameArray we popped
 726   // Holds updates by JVMTI agents for compiled frames that cannot be performed immediately. They
 727   // will be carried out as soon as possible which, in most cases, is just before deoptimization of
 728   // the frame, when control returns to it.
 729   JvmtiDeferredUpdates* _jvmti_deferred_updates;
 730 
 731   // Handshake value for fixing 6243940. We need a place for the i2c
 732   // adapter to store the callee Method*. This value is NEVER live
 733   // across a gc point so it does NOT have to be gc'd
 734   // The handshake is open ended since we can't be certain that it will
 735   // be NULLed. This is because we rarely ever see the race and end up
 736   // in handle_wrong_method which is the backend of the handshake. See
 737   // code in i2c adapters and handle_wrong_method.
 738 
 739   Method*       _callee_target;
 740 
 741   // Used to pass back results to the interpreter or generated code running Java code.
 742   oop           _vm_result;    // oop result is GC-preserved
 743   Metadata*     _vm_result_2;  // non-oop result
 744 
 745   // See ReduceInitialCardMarks: this holds the precise space interval of
 746   // the most recent slow path allocation for which compiled code has
 747   // elided card-marks for performance along the fast-path.
 748   MemRegion     _deferred_card_mark;
 749 
 750   ObjectMonitor* volatile _current_pending_monitor;     // ObjectMonitor this thread is waiting to lock
 751   bool           _current_pending_monitor_is_from_java; // locking is from Java code
 752   ObjectMonitor* volatile _current_waiting_monitor;     // ObjectMonitor on which this thread called Object.wait()
 753  public:
 754   volatile intptr_t _Stalled;
 755 
 756   // For tracking the heavyweight monitor the thread is pending on.
 757   ObjectMonitor* current_pending_monitor() {
 758     // Use Atomic::load() to prevent data race between concurrent modification and
 759     // concurrent readers, e.g. ThreadService::get_current_contended_monitor().
 760     // Especially, reloading pointer from thread after NULL check must be prevented.
 761     return Atomic::load(&_current_pending_monitor);
 762   }
 763   void set_current_pending_monitor(ObjectMonitor* monitor) {
 764     Atomic::store(&_current_pending_monitor, monitor);
 765   }
 766   void set_current_pending_monitor_is_from_java(bool from_java) {
 767     _current_pending_monitor_is_from_java = from_java;
 768   }
 769   bool current_pending_monitor_is_from_java() {
 770     return _current_pending_monitor_is_from_java;
 771   }
 772   ObjectMonitor* current_waiting_monitor() {
 773     // See the comment in current_pending_monitor() above.
 774     return Atomic::load(&_current_waiting_monitor);
 775   }
 776   void set_current_waiting_monitor(ObjectMonitor* monitor) {
 777     Atomic::store(&_current_waiting_monitor, monitor);
 778   }
 779 
 780  private:
 781   MonitorChunk* _monitor_chunks;              // Contains the off stack monitors
 782                                               // allocated during deoptimization
 783                                               // and by JNI_MonitorEnter/Exit
 784 
 785   enum SuspendFlags {
 786     // NOTE: avoid using the sign-bit as cc generates different test code
 787     //       when the sign-bit is used, and sometimes incorrectly - see CR 6398077
 788     _has_async_exception    = 0x00000001U, // there is a pending async exception
 789     _trace_flag             = 0x00000004U, // call tracing backend
 790     _obj_deopt              = 0x00000008U  // suspend for object reallocation and relocking for JVMTI agent
 791   };
 792 
 793   // various suspension related flags - atomically updated
 794   // overloaded with async exceptions so that we do a single check when transitioning from native->Java
 795   volatile uint32_t _suspend_flags;
 796 
 797   inline void set_suspend_flag(SuspendFlags f);
 798   inline void clear_suspend_flag(SuspendFlags f);
 799 
 800  public:
 801   inline void set_trace_flag();
 802   inline void clear_trace_flag();
 803   inline void set_obj_deopt_flag();
 804   inline void clear_obj_deopt_flag();
 805   bool is_trace_suspend()      { return (_suspend_flags & _trace_flag) != 0; }
 806   bool is_obj_deopt_suspend()  { return (_suspend_flags & _obj_deopt) != 0; }
 807 
 808   // Asynchronous exceptions support
 809  private:
 810   enum AsyncExceptionCondition {
 811     _no_async_condition = 0,
 812     _async_exception,
 813     _async_unsafe_access_error
 814   };
 815   AsyncExceptionCondition _async_exception_condition;
 816   oop                     _pending_async_exception;
 817 
 818   void set_async_exception_condition(AsyncExceptionCondition aec) { _async_exception_condition = aec; }
 819   AsyncExceptionCondition clear_async_exception_condition() {
 820     AsyncExceptionCondition x = _async_exception_condition;
 821     _async_exception_condition = _no_async_condition;
 822     return x;
 823   }
 824 
 825  public:
 826   bool has_async_exception_condition(bool check_unsafe_access_error = true) {
 827     return check_unsafe_access_error ? _async_exception_condition != _no_async_condition
 828                                      : _async_exception_condition == _async_exception;
 829   }
 830   inline void set_pending_async_exception(oop e);
 831   void set_pending_unsafe_access_error()  {
 832     // Don't overwrite an asynchronous exception sent by another thread
 833     if (_async_exception_condition == _no_async_condition) {
 834       set_async_exception_condition(_async_unsafe_access_error);
 835     }
 836   }
 837   void check_and_handle_async_exceptions();
 838   // Installs a pending exception to be inserted later
 839   static void send_async_exception(oop thread_oop, oop java_throwable);
 840   void send_thread_stop(oop throwable);
 841 
 842   // Safepoint support
 843  public:                                                        // Expose _thread_state for SafeFetchInt()
 844   volatile JavaThreadState _thread_state;
 845  private:
 846   SafepointMechanism::ThreadData _poll_data;
 847   ThreadSafepointState*          _safepoint_state;              // Holds information about a thread during a safepoint
 848   address                        _saved_exception_pc;           // Saved pc of instruction where last implicit exception happened
 849   NOT_PRODUCT(bool               _requires_cross_modify_fence;) // State used by VerifyCrossModifyFence
 850 #ifdef ASSERT
 851   // Debug support for checking if code allows safepoints or not.
 852   // Safepoints in the VM can happen because of allocation, invoking a VM operation, or blocking on
 853   // mutex, or blocking on an object synchronizer (Java locking).
 854   // If _no_safepoint_count is non-zero, then an assertion failure will happen in any of
 855   // the above cases. The class NoSafepointVerifier is used to set this counter.
 856   int _no_safepoint_count;                             // If 0, thread allow a safepoint to happen
 857 
 858  public:
 859   void inc_no_safepoint_count() { _no_safepoint_count++; }
 860   void dec_no_safepoint_count() { _no_safepoint_count--; }
 861 #endif // ASSERT
 862  public:
 863   // These functions check conditions before possibly going to a safepoint.
 864   // including NoSafepointVerifier.
 865   void check_for_valid_safepoint_state() NOT_DEBUG_RETURN;
 866   void check_possible_safepoint()        NOT_DEBUG_RETURN;
 867 
 868 #ifdef ASSERT
 869  private:
 870   volatile uint64_t _visited_for_critical_count;
 871 
 872  public:
 873   void set_visited_for_critical_count(uint64_t safepoint_id) {
 874     assert(_visited_for_critical_count == 0, "Must be reset before set");
 875     assert((safepoint_id & 0x1) == 1, "Must be odd");
 876     _visited_for_critical_count = safepoint_id;
 877   }
 878   void reset_visited_for_critical_count(uint64_t safepoint_id) {
 879     assert(_visited_for_critical_count == safepoint_id, "Was not visited");
 880     _visited_for_critical_count = 0;
 881   }
 882   bool was_visited_for_critical_count(uint64_t safepoint_id) const {
 883     return _visited_for_critical_count == safepoint_id;
 884   }
 885 #endif // ASSERT
 886 
 887   // JavaThread termination support
 888  public:
 889   enum TerminatedTypes {
 890     _not_terminated = 0xDEAD - 2,
 891     _thread_exiting,                             // JavaThread::exit() has been called for this thread
 892     _thread_terminated,                          // JavaThread is removed from thread list
 893     _vm_exited                                   // JavaThread is still executing native code, but VM is terminated
 894                                                  // only VM_Exit can set _vm_exited
 895   };
 896 
 897  private:
 898   // In general a JavaThread's _terminated field transitions as follows:
 899   //
 900   //   _not_terminated => _thread_exiting => _thread_terminated
 901   //
 902   // _vm_exited is a special value to cover the case of a JavaThread
 903   // executing native code after the VM itself is terminated.
 904   volatile TerminatedTypes _terminated;
 905 
 906   jint                  _in_deopt_handler;       // count of deoptimization
 907                                                  // handlers thread is in
 908   volatile bool         _doing_unsafe_access;    // Thread may fault due to unsafe access
 909   bool                  _do_not_unlock_if_synchronized;  // Do not unlock the receiver of a synchronized method (since it was
 910                                                          // never locked) when throwing an exception. Used by interpreter only.
 911 
 912   // JNI attach states:
 913   enum JNIAttachStates {
 914     _not_attaching_via_jni = 1,  // thread is not attaching via JNI
 915     _attaching_via_jni,          // thread is attaching via JNI
 916     _attached_via_jni            // thread has attached via JNI
 917   };
 918 
 919   // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
 920   // A native thread that is attaching via JNI starts with a value
 921   // of _attaching_via_jni and transitions to _attached_via_jni.
 922   volatile JNIAttachStates _jni_attach_state;
 923 
 924 
 925 #if INCLUDE_JVMCI
 926   // The _pending_* fields below are used to communicate extra information
 927   // from an uncommon trap in JVMCI compiled code to the uncommon trap handler.
 928 
 929   // Communicates the DeoptReason and DeoptAction of the uncommon trap
 930   int       _pending_deoptimization;
 931 
 932   // Specifies whether the uncommon trap is to bci 0 of a synchronized method
 933   // before the monitor has been acquired.
 934   bool      _pending_monitorenter;
 935 
 936   // Specifies if the DeoptReason for the last uncommon trap was Reason_transfer_to_interpreter
 937   bool      _pending_transfer_to_interpreter;
 938 
 939   // True if in a runtime call from compiled code that will deoptimize
 940   // and re-execute a failed heap allocation in the interpreter.
 941   bool      _in_retryable_allocation;
 942 
 943   // An id of a speculation that JVMCI compiled code can use to further describe and
 944   // uniquely identify the speculative optimization guarded by an uncommon trap.
 945   // See JVMCINMethodData::SPECULATION_LENGTH_BITS for further details.
 946   jlong     _pending_failed_speculation;
 947 
 948   // These fields are mutually exclusive in terms of live ranges.
 949   union {
 950     // Communicates the pc at which the most recent implicit exception occurred
 951     // from the signal handler to a deoptimization stub.
 952     address   _implicit_exception_pc;
 953 
 954     // Communicates an alternative call target to an i2c stub from a JavaCall .
 955     address   _alternate_call_target;
 956   } _jvmci;
 957 
 958   // Support for high precision, thread sensitive counters in JVMCI compiled code.
 959   jlong*    _jvmci_counters;
 960 
 961   // Fast thread locals for use by JVMCI
 962   jlong      _jvmci_reserved0;
 963   jlong      _jvmci_reserved1;
 964   oop        _jvmci_reserved_oop0;
 965 
 966  public:
 967   static jlong* _jvmci_old_thread_counters;
 968   static void collect_counters(jlong* array, int length);
 969 
 970   bool resize_counters(int current_size, int new_size);
 971 
 972   static bool resize_all_jvmci_counters(int new_size);
 973 
 974   void set_jvmci_reserved_oop0(oop value) {
 975     _jvmci_reserved_oop0 = value;
 976   }
 977 
 978   oop get_jvmci_reserved_oop0() {
 979     return _jvmci_reserved_oop0;
 980   }
 981 
 982   void set_jvmci_reserved0(jlong value) {
 983     _jvmci_reserved0 = value;
 984   }
 985 
 986   jlong get_jvmci_reserved0() {
 987     return _jvmci_reserved0;
 988   }
 989 
 990   void set_jvmci_reserved1(jlong value) {
 991     _jvmci_reserved1 = value;
 992   }
 993 
 994   jlong get_jvmci_reserved1() {
 995     return _jvmci_reserved1;
 996   }
 997 
 998  private:
 999 #endif // INCLUDE_JVMCI
1000 
1001   StackOverflow    _stack_overflow_state;
1002 
1003   // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
1004   // used to temp. parsing values into and out of the runtime system during exception handling for compiled
1005   // code)
1006   volatile oop     _exception_oop;               // Exception thrown in compiled code
1007   volatile address _exception_pc;                // PC where exception happened
1008   volatile address _exception_handler_pc;        // PC for handler of exception
1009   volatile int     _is_method_handle_return;     // true (== 1) if the current exception PC is a MethodHandle call site.
1010 
1011  private:
1012   // support for JNI critical regions
1013   jint    _jni_active_critical;                  // count of entries into JNI critical region
1014 
1015   // Checked JNI: function name requires exception check
1016   char* _pending_jni_exception_check_fn;
1017 
1018   // For deadlock detection.
1019   int _depth_first_number;
1020 
1021   // JVMTI PopFrame support
1022   // This is set to popframe_pending to signal that top Java frame should be popped immediately
1023   int _popframe_condition;
1024 
1025   // If reallocation of scalar replaced objects fails, we throw OOM
1026   // and during exception propagation, pop the top
1027   // _frames_to_pop_failed_realloc frames, the ones that reference
1028   // failed reallocations.
1029   int _frames_to_pop_failed_realloc;
1030 
1031   friend class VMThread;
1032   friend class ThreadWaitTransition;
1033   friend class VM_Exit;
1034 
1035   // Stack watermark barriers.
1036   StackWatermarks _stack_watermarks;
1037 
1038  public:
1039   inline StackWatermarks* stack_watermarks() { return &_stack_watermarks; }
1040 
1041  public:
1042   // Constructor
1043   JavaThread();                            // delegating constructor
1044   JavaThread(bool is_attaching_via_jni);   // for main thread and JNI attached threads
1045   JavaThread(ThreadFunction entry_point, size_t stack_size = 0);
1046   ~JavaThread();
1047 
1048 #ifdef ASSERT
1049   // verify this JavaThread hasn't be published in the Threads::list yet
1050   void verify_not_published();
1051 #endif // ASSERT
1052 
1053   StackOverflow* stack_overflow_state() { return &_stack_overflow_state; }
1054 
1055   //JNI functiontable getter/setter for JVMTI jni function table interception API.
1056   void set_jni_functions(struct JNINativeInterface_* functionTable) {
1057     _jni_environment.functions = functionTable;
1058   }
1059   struct JNINativeInterface_* get_jni_functions() {
1060     return (struct JNINativeInterface_ *)_jni_environment.functions;
1061   }
1062 
1063   // This function is called at thread creation to allow
1064   // platform specific thread variables to be initialized.
1065   void cache_global_variables();
1066 
1067   // Executes Shutdown.shutdown()
1068   void invoke_shutdown_hooks();
1069 
1070   // Cleanup on thread exit
1071   enum ExitType {
1072     normal_exit,
1073     jni_detach
1074   };
1075   void exit(bool destroy_vm, ExitType exit_type = normal_exit);
1076 
1077   void cleanup_failed_attach_current_thread(bool is_daemon);
1078 
1079   // Testers
1080   virtual bool is_Java_thread() const            { return true;  }
1081   virtual bool can_call_java() const             { return true; }
1082 
1083   virtual bool is_active_Java_thread() const {
1084     return on_thread_list() && !is_terminated();
1085   }
1086 
1087   // Thread oop. threadObj() can be NULL for initial JavaThread
1088   // (or for threads attached via JNI)
1089   oop threadObj() const;
1090   void set_threadObj(oop p);
1091 
1092   // Prepare thread and add to priority queue.  If a priority is
1093   // not specified, use the priority of the thread object. Threads_lock
1094   // must be held while this function is called.
1095   void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
1096 
1097   void set_saved_exception_pc(address pc)        { _saved_exception_pc = pc; }
1098   address saved_exception_pc()                   { return _saved_exception_pc; }
1099 
1100   ThreadFunction entry_point() const             { return _entry_point; }
1101 
1102   // Allocates a new Java level thread object for this thread. thread_name may be NULL.
1103   void allocate_threadObj(Handle thread_group, const char* thread_name, bool daemon, TRAPS);
1104 
1105   // Last frame anchor routines
1106 
1107   JavaFrameAnchor* frame_anchor(void)            { return &_anchor; }
1108 
1109   // last_Java_sp
1110   bool has_last_Java_frame() const               { return _anchor.has_last_Java_frame(); }
1111   intptr_t* last_Java_sp() const                 { return _anchor.last_Java_sp(); }
1112 
1113   // last_Java_pc
1114 
1115   address last_Java_pc(void)                     { return _anchor.last_Java_pc(); }
1116 
1117   // Safepoint support
1118   inline JavaThreadState thread_state() const;
1119   inline void set_thread_state(JavaThreadState s);
1120   inline void set_thread_state_fence(JavaThreadState s);  // fence after setting thread state
1121   inline ThreadSafepointState* safepoint_state() const;
1122   inline void set_safepoint_state(ThreadSafepointState* state);
1123   inline bool is_at_poll_safepoint();
1124 
1125   // JavaThread termination and lifecycle support:
1126   void smr_delete();
1127   bool on_thread_list() const { return _on_thread_list; }
1128   void set_on_thread_list() { _on_thread_list = true; }
1129 
1130   // thread has called JavaThread::exit() or is terminated
1131   bool is_exiting() const;
1132   // thread is terminated (no longer on the threads list); we compare
1133   // against the two non-terminated values so that a freed JavaThread
1134   // will also be considered terminated.
1135   bool check_is_terminated(TerminatedTypes l_terminated) const {
1136     return l_terminated != _not_terminated && l_terminated != _thread_exiting;
1137   }
1138   bool is_terminated() const;
1139   void set_terminated(TerminatedTypes t);
1140 
1141   void block_if_vm_exited();
1142 
1143   bool doing_unsafe_access()                     { return _doing_unsafe_access; }
1144   void set_doing_unsafe_access(bool val)         { _doing_unsafe_access = val; }
1145 
1146   bool do_not_unlock_if_synchronized()             { return _do_not_unlock_if_synchronized; }
1147   void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
1148 
1149   SafepointMechanism::ThreadData* poll_data() { return &_poll_data; }
1150 
1151   void set_requires_cross_modify_fence(bool val) PRODUCT_RETURN NOT_PRODUCT({ _requires_cross_modify_fence = val; })
1152 
1153  private:
1154   DEBUG_ONLY(void verify_frame_info();)
1155 
1156   // Support for thread handshake operations
1157   HandshakeState _handshake;
1158  public:
1159   HandshakeState* handshake_state() { return &_handshake; }
1160 
1161   // A JavaThread can always safely operate on it self and other threads
1162   // can do it safely if they are the active handshaker.
1163   bool is_handshake_safe_for(Thread* th) const {
1164     return _handshake.active_handshaker() == th || this == th;
1165   }
1166 
1167   // Suspend/resume support for JavaThread
1168   bool java_suspend(); // higher-level suspension logic called by the public APIs
1169   bool java_resume();  // higher-level resume logic called by the public APIs
1170   bool is_suspended()     { return _handshake.is_suspended(); }
1171 
1172   // Check for async exception in addition to safepoint.
1173   static void check_special_condition_for_native_trans(JavaThread *thread);
1174 
1175   // Synchronize with another thread that is deoptimizing objects of the
1176   // current thread, i.e. reverts optimizations based on escape analysis.
1177   void wait_for_object_deoptimization();
1178 
1179   // these next two are also used for self-suspension and async exception support
1180   void handle_special_runtime_exit_condition(bool check_asyncs = true);
1181 
1182   // Return true if JavaThread has an asynchronous condition or
1183   // if external suspension is requested.
1184   bool has_special_runtime_exit_condition() {
1185     return (_async_exception_condition != _no_async_condition) ||
1186            (_suspend_flags & (_obj_deopt JFR_ONLY(| _trace_flag))) != 0;
1187   }
1188 
1189   // Fast-locking support
1190   bool is_lock_owned(address adr) const;
1191 
1192   // Accessors for vframe array top
1193   // The linked list of vframe arrays are sorted on sp. This means when we
1194   // unpack the head must contain the vframe array to unpack.
1195   void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
1196   vframeArray* vframe_array_head() const         { return _vframe_array_head;  }
1197 
1198   // Side structure for deferring update of java frame locals until deopt occurs
1199   JvmtiDeferredUpdates* deferred_updates() const      { return _jvmti_deferred_updates; }
1200   void set_deferred_updates(JvmtiDeferredUpdates* du) { _jvmti_deferred_updates = du; }
1201 
1202   // These only really exist to make debugging deopt problems simpler
1203 
1204   void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
1205   vframeArray* vframe_array_last() const         { return _vframe_array_last;  }
1206 
1207   // The special resourceMark used during deoptimization
1208 
1209   void set_deopt_mark(DeoptResourceMark* value)  { _deopt_mark = value; }
1210   DeoptResourceMark* deopt_mark(void)            { return _deopt_mark; }
1211 
1212   void set_deopt_compiled_method(CompiledMethod* nm)  { _deopt_nmethod = nm; }
1213   CompiledMethod* deopt_compiled_method()        { return _deopt_nmethod; }
1214 
1215   Method*    callee_target() const               { return _callee_target; }
1216   void set_callee_target  (Method* x)          { _callee_target   = x; }
1217 
1218   // Oop results of vm runtime calls
1219   oop  vm_result() const                         { return _vm_result; }
1220   void set_vm_result  (oop x)                    { _vm_result   = x; }
1221 
1222   Metadata*    vm_result_2() const               { return _vm_result_2; }
1223   void set_vm_result_2  (Metadata* x)          { _vm_result_2   = x; }
1224 
1225   MemRegion deferred_card_mark() const           { return _deferred_card_mark; }
1226   void set_deferred_card_mark(MemRegion mr)      { _deferred_card_mark = mr;   }
1227 
1228 #if INCLUDE_JVMCI
1229   int  pending_deoptimization() const             { return _pending_deoptimization; }
1230   jlong pending_failed_speculation() const        { return _pending_failed_speculation; }
1231   bool has_pending_monitorenter() const           { return _pending_monitorenter; }
1232   void set_pending_monitorenter(bool b)           { _pending_monitorenter = b; }
1233   void set_pending_deoptimization(int reason)     { _pending_deoptimization = reason; }
1234   void set_pending_failed_speculation(jlong failed_speculation) { _pending_failed_speculation = failed_speculation; }
1235   void set_pending_transfer_to_interpreter(bool b) { _pending_transfer_to_interpreter = b; }
1236   void set_jvmci_alternate_call_target(address a) { assert(_jvmci._alternate_call_target == NULL, "must be"); _jvmci._alternate_call_target = a; }
1237   void set_jvmci_implicit_exception_pc(address a) { assert(_jvmci._implicit_exception_pc == NULL, "must be"); _jvmci._implicit_exception_pc = a; }
1238 
1239   virtual bool in_retryable_allocation() const    { return _in_retryable_allocation; }
1240   void set_in_retryable_allocation(bool b)        { _in_retryable_allocation = b; }
1241 #endif // INCLUDE_JVMCI
1242 
1243   // Exception handling for compiled methods
1244   oop      exception_oop() const;
1245   address  exception_pc() const                  { return _exception_pc; }
1246   address  exception_handler_pc() const          { return _exception_handler_pc; }
1247   bool     is_method_handle_return() const       { return _is_method_handle_return == 1; }
1248 
1249   void set_exception_oop(oop o);
1250   void set_exception_pc(address a)               { _exception_pc = a; }
1251   void set_exception_handler_pc(address a)       { _exception_handler_pc = a; }
1252   void set_is_method_handle_return(bool value)   { _is_method_handle_return = value ? 1 : 0; }
1253 
1254   void clear_exception_oop_and_pc() {
1255     set_exception_oop(NULL);
1256     set_exception_pc(NULL);
1257   }
1258 
1259   // Check if address is in the usable part of the stack (excludes protected
1260   // guard pages). Can be applied to any thread and is an approximation for
1261   // using is_in_live_stack when the query has to happen from another thread.
1262   bool is_in_usable_stack(address adr) const {
1263     return is_in_stack_range_incl(adr, _stack_overflow_state.stack_reserved_zone_base());
1264   }
1265 
1266   // Misc. accessors/mutators
1267   void set_do_not_unlock(void)                   { _do_not_unlock_if_synchronized = true; }
1268   void clr_do_not_unlock(void)                   { _do_not_unlock_if_synchronized = false; }
1269   bool do_not_unlock(void)                       { return _do_not_unlock_if_synchronized; }
1270 
1271   // For assembly stub generation
1272   static ByteSize threadObj_offset()             { return byte_offset_of(JavaThread, _threadObj); }
1273   static ByteSize jni_environment_offset()       { return byte_offset_of(JavaThread, _jni_environment); }
1274   static ByteSize pending_jni_exception_check_fn_offset() {
1275     return byte_offset_of(JavaThread, _pending_jni_exception_check_fn);
1276   }
1277   static ByteSize last_Java_sp_offset() {
1278     return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
1279   }
1280   static ByteSize last_Java_pc_offset() {
1281     return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
1282   }
1283   static ByteSize frame_anchor_offset() {
1284     return byte_offset_of(JavaThread, _anchor);
1285   }
1286   static ByteSize callee_target_offset()         { return byte_offset_of(JavaThread, _callee_target); }
1287   static ByteSize vm_result_offset()             { return byte_offset_of(JavaThread, _vm_result); }
1288   static ByteSize vm_result_2_offset()           { return byte_offset_of(JavaThread, _vm_result_2); }
1289   static ByteSize thread_state_offset()          { return byte_offset_of(JavaThread, _thread_state); }
1290   static ByteSize polling_word_offset()          { return byte_offset_of(JavaThread, _poll_data) + byte_offset_of(SafepointMechanism::ThreadData, _polling_word);}
1291   static ByteSize polling_page_offset()          { return byte_offset_of(JavaThread, _poll_data) + byte_offset_of(SafepointMechanism::ThreadData, _polling_page);}
1292   static ByteSize saved_exception_pc_offset()    { return byte_offset_of(JavaThread, _saved_exception_pc); }
1293   static ByteSize osthread_offset()              { return byte_offset_of(JavaThread, _osthread); }
1294 #if INCLUDE_JVMCI
1295   static ByteSize pending_deoptimization_offset() { return byte_offset_of(JavaThread, _pending_deoptimization); }
1296   static ByteSize pending_monitorenter_offset()  { return byte_offset_of(JavaThread, _pending_monitorenter); }
1297   static ByteSize pending_failed_speculation_offset() { return byte_offset_of(JavaThread, _pending_failed_speculation); }
1298   static ByteSize jvmci_alternate_call_target_offset() { return byte_offset_of(JavaThread, _jvmci._alternate_call_target); }
1299   static ByteSize jvmci_implicit_exception_pc_offset() { return byte_offset_of(JavaThread, _jvmci._implicit_exception_pc); }
1300   static ByteSize jvmci_counters_offset()        { return byte_offset_of(JavaThread, _jvmci_counters); }
1301 #endif // INCLUDE_JVMCI
1302   static ByteSize exception_oop_offset()         { return byte_offset_of(JavaThread, _exception_oop); }
1303   static ByteSize exception_pc_offset()          { return byte_offset_of(JavaThread, _exception_pc); }
1304   static ByteSize exception_handler_pc_offset()  { return byte_offset_of(JavaThread, _exception_handler_pc); }
1305   static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); }
1306 
1307   // StackOverflow offsets
1308   static ByteSize stack_overflow_limit_offset()  {
1309     return byte_offset_of(JavaThread, _stack_overflow_state._stack_overflow_limit);
1310   }
1311   static ByteSize stack_guard_state_offset()     {
1312     return byte_offset_of(JavaThread, _stack_overflow_state._stack_guard_state);
1313   }
1314   static ByteSize reserved_stack_activation_offset() {
1315     return byte_offset_of(JavaThread, _stack_overflow_state._reserved_stack_activation);
1316   }
1317 
1318   static ByteSize suspend_flags_offset()         { return byte_offset_of(JavaThread, _suspend_flags); }
1319 
1320   static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
1321   static ByteSize should_post_on_exceptions_flag_offset() {
1322     return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
1323   }
1324   static ByteSize doing_unsafe_access_offset() { return byte_offset_of(JavaThread, _doing_unsafe_access); }
1325   NOT_PRODUCT(static ByteSize requires_cross_modify_fence_offset()  { return byte_offset_of(JavaThread, _requires_cross_modify_fence); })
1326 
1327   // Returns the jni environment for this thread
1328   JNIEnv* jni_environment()                      { return &_jni_environment; }
1329 
1330   static JavaThread* thread_from_jni_environment(JNIEnv* env) {
1331     JavaThread *thread_from_jni_env = (JavaThread*)((intptr_t)env - in_bytes(jni_environment_offset()));
1332     // Only return NULL if thread is off the thread list; starting to
1333     // exit should not return NULL.
1334     if (thread_from_jni_env->is_terminated()) {
1335       thread_from_jni_env->block_if_vm_exited();
1336       return NULL;
1337     } else {
1338       return thread_from_jni_env;
1339     }
1340   }
1341 
1342   // JNI critical regions. These can nest.
1343   bool in_critical()    { return _jni_active_critical > 0; }
1344   bool in_last_critical()  { return _jni_active_critical == 1; }
1345   inline void enter_critical();
1346   void exit_critical() {
1347     assert(Thread::current() == this, "this must be current thread");
1348     _jni_active_critical--;
1349     assert(_jni_active_critical >= 0, "JNI critical nesting problem?");
1350   }
1351 
1352   // Checked JNI: is the programmer required to check for exceptions, if so specify
1353   // which function name. Returning to a Java frame should implicitly clear the
1354   // pending check, this is done for Native->Java transitions (i.e. user JNI code).
1355   // VM->Java transistions are not cleared, it is expected that JNI code enclosed
1356   // within ThreadToNativeFromVM makes proper exception checks (i.e. VM internal).
1357   bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != NULL; }
1358   void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = NULL; }
1359   const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; }
1360   void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; }
1361 
1362   // For deadlock detection
1363   int depth_first_number() { return _depth_first_number; }
1364   void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
1365 
1366  private:
1367   void set_monitor_chunks(MonitorChunk* monitor_chunks) { _monitor_chunks = monitor_chunks; }
1368 
1369  public:
1370   MonitorChunk* monitor_chunks() const           { return _monitor_chunks; }
1371   void add_monitor_chunk(MonitorChunk* chunk);
1372   void remove_monitor_chunk(MonitorChunk* chunk);
1373   bool in_deopt_handler() const                  { return _in_deopt_handler > 0; }
1374   void inc_in_deopt_handler()                    { _in_deopt_handler++; }
1375   void dec_in_deopt_handler() {
1376     assert(_in_deopt_handler > 0, "mismatched deopt nesting");
1377     if (_in_deopt_handler > 0) { // robustness
1378       _in_deopt_handler--;
1379     }
1380   }
1381 
1382  private:
1383   void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
1384 
1385  public:
1386 
1387   // Frame iteration; calls the function f for all frames on the stack
1388   void frames_do(void f(frame*, const RegisterMap*));
1389 
1390   // Memory operations
1391   void oops_do_frames(OopClosure* f, CodeBlobClosure* cf);
1392   void oops_do_no_frames(OopClosure* f, CodeBlobClosure* cf);
1393 
1394   // Sweeper operations
1395   virtual void nmethods_do(CodeBlobClosure* cf);
1396 
1397   // RedefineClasses Support
1398   void metadata_do(MetadataClosure* f);
1399 
1400   // Debug method asserting thread states are correct during a handshake operation.
1401   DEBUG_ONLY(void verify_states_for_handshake();)
1402 
1403   // Misc. operations
1404   char* name() const { return (char*)get_thread_name(); }
1405   static const char* name_for(oop thread_obj);
1406   void print_on(outputStream* st, bool print_extended_info) const;
1407   void print_on(outputStream* st) const { print_on(st, false); }
1408   void print() const;
1409   void print_thread_state_on(outputStream*) const      PRODUCT_RETURN;
1410   void print_on_error(outputStream* st, char* buf, int buflen) const;
1411   void print_name_on_error(outputStream* st, char* buf, int buflen) const;
1412   void verify();
1413   const char* get_thread_name() const;
1414  protected:
1415   // factor out low-level mechanics for use in both normal and error cases
1416   virtual const char* get_thread_name_string(char* buf = NULL, int buflen = 0) const;
1417  public:
1418   // Accessing frames
1419   frame last_frame() {
1420     _anchor.make_walkable();
1421     return pd_last_frame();
1422   }
1423   javaVFrame* last_java_vframe(RegisterMap* reg_map);
1424 
1425   // Returns method at 'depth' java or native frames down the stack
1426   // Used for security checks
1427   Klass* security_get_caller_class(int depth);
1428 
1429   // Print stack trace in external format
1430   void print_stack_on(outputStream* st);
1431   void print_stack() { print_stack_on(tty); }
1432 
1433   // Print stack traces in various internal formats
1434   void trace_stack()                             PRODUCT_RETURN;
1435   void trace_stack_from(vframe* start_vf)        PRODUCT_RETURN;
1436   void trace_frames()                            PRODUCT_RETURN;
1437 
1438   // Print an annotated view of the stack frames
1439   void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN;
1440   void validate_frame_layout() {
1441     print_frame_layout(0, true);
1442   }
1443 
1444   // Function for testing deoptimization
1445   void deoptimize();
1446   void make_zombies();
1447 
1448   void deoptimize_marked_methods();
1449 
1450  public:
1451   // Returns the running thread as a JavaThread
1452   static inline JavaThread* current();
1453   // Returns the current thread as a JavaThread, or NULL if not attached
1454   static inline JavaThread* current_or_null();
1455 
1456   // Returns the active Java thread.  Do not use this if you know you are calling
1457   // from a JavaThread, as it's slower than JavaThread::current.  If called from
1458   // the VMThread, it also returns the JavaThread that instigated the VMThread's
1459   // operation.  You may not want that either.
1460   static JavaThread* active();
1461 
1462  protected:
1463   virtual void pre_run();
1464   virtual void run();
1465   void thread_main_inner();
1466   virtual void post_run();
1467 
1468  public:
1469   // Thread local information maintained by JVMTI.
1470   void set_jvmti_thread_state(JvmtiThreadState *value)                           { _jvmti_thread_state = value; }
1471   // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1472   // getter is used to get this JavaThread's JvmtiThreadState if it has
1473   // one which means NULL can be returned. JvmtiThreadState::state_for()
1474   // is used to get the specified JavaThread's JvmtiThreadState if it has
1475   // one or it allocates a new JvmtiThreadState for the JavaThread and
1476   // returns it. JvmtiThreadState::state_for() will return NULL only if
1477   // the specified JavaThread is exiting.
1478   JvmtiThreadState *jvmti_thread_state() const                                   { return _jvmti_thread_state; }
1479   static ByteSize jvmti_thread_state_offset()                                    { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1480 
1481   // JVMTI PopFrame support
1482   // Setting and clearing popframe_condition
1483   // All of these enumerated values are bits. popframe_pending
1484   // indicates that a PopFrame() has been requested and not yet been
1485   // completed. popframe_processing indicates that that PopFrame() is in
1486   // the process of being completed. popframe_force_deopt_reexecution_bit
1487   // indicates that special handling is required when returning to a
1488   // deoptimized caller.
1489   enum PopCondition {
1490     popframe_inactive                      = 0x00,
1491     popframe_pending_bit                   = 0x01,
1492     popframe_processing_bit                = 0x02,
1493     popframe_force_deopt_reexecution_bit   = 0x04
1494   };
1495   PopCondition popframe_condition()                   { return (PopCondition) _popframe_condition; }
1496   void set_popframe_condition(PopCondition c)         { _popframe_condition = c; }
1497   void set_popframe_condition_bit(PopCondition c)     { _popframe_condition |= c; }
1498   void clear_popframe_condition()                     { _popframe_condition = popframe_inactive; }
1499   static ByteSize popframe_condition_offset()         { return byte_offset_of(JavaThread, _popframe_condition); }
1500   bool has_pending_popframe()                         { return (popframe_condition() & popframe_pending_bit) != 0; }
1501   bool popframe_forcing_deopt_reexecution()           { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
1502   void clear_popframe_forcing_deopt_reexecution()     { _popframe_condition &= ~popframe_force_deopt_reexecution_bit; }
1503 
1504   bool pop_frame_in_process(void)                     { return ((_popframe_condition & popframe_processing_bit) != 0); }
1505   void set_pop_frame_in_process(void)                 { _popframe_condition |= popframe_processing_bit; }
1506   void clr_pop_frame_in_process(void)                 { _popframe_condition &= ~popframe_processing_bit; }
1507 
1508   int frames_to_pop_failed_realloc() const            { return _frames_to_pop_failed_realloc; }
1509   void set_frames_to_pop_failed_realloc(int nb)       { _frames_to_pop_failed_realloc = nb; }
1510   void dec_frames_to_pop_failed_realloc()             { _frames_to_pop_failed_realloc--; }
1511 
1512  private:
1513   // Saved incoming arguments to popped frame.
1514   // Used only when popped interpreted frame returns to deoptimized frame.
1515   void*    _popframe_preserved_args;
1516   int      _popframe_preserved_args_size;
1517 
1518  public:
1519   void  popframe_preserve_args(ByteSize size_in_bytes, void* start);
1520   void* popframe_preserved_args();
1521   ByteSize popframe_preserved_args_size();
1522   WordSize popframe_preserved_args_size_in_words();
1523   void  popframe_free_preserved_args();
1524 
1525 
1526  private:
1527   JvmtiThreadState *_jvmti_thread_state;
1528 
1529   // Used by the interpreter in fullspeed mode for frame pop, method
1530   // entry, method exit and single stepping support. This field is
1531   // only set to non-zero at a safepoint or using a direct handshake
1532   // (see EnterInterpOnlyModeClosure).
1533   // It can be set to zero asynchronously to this threads execution (i.e., without
1534   // safepoint/handshake or a lock) so we have to be very careful.
1535   // Accesses by other threads are synchronized using JvmtiThreadState_lock though.
1536   int               _interp_only_mode;
1537 
1538  public:
1539   // used by the interpreter for fullspeed debugging support (see above)
1540   static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
1541   bool is_interp_only_mode()                { return (_interp_only_mode != 0); }
1542   int get_interp_only_mode()                { return _interp_only_mode; }
1543   void increment_interp_only_mode()         { ++_interp_only_mode; }
1544   void decrement_interp_only_mode()         { --_interp_only_mode; }
1545 
1546   // support for cached flag that indicates whether exceptions need to be posted for this thread
1547   // if this is false, we can avoid deoptimizing when events are thrown
1548   // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
1549  private:
1550   int    _should_post_on_exceptions_flag;
1551 
1552  public:
1553   int   should_post_on_exceptions_flag()  { return _should_post_on_exceptions_flag; }
1554   void  set_should_post_on_exceptions_flag(int val)  { _should_post_on_exceptions_flag = val; }
1555 
1556  private:
1557   ThreadStatistics *_thread_stat;
1558 
1559  public:
1560   ThreadStatistics* get_thread_stat() const    { return _thread_stat; }
1561 
1562   // Return a blocker object for which this thread is blocked parking.
1563   oop current_park_blocker();
1564 
1565  private:
1566   static size_t _stack_size_at_create;
1567 
1568  public:
1569   static inline size_t stack_size_at_create(void) {
1570     return _stack_size_at_create;
1571   }
1572   static inline void set_stack_size_at_create(size_t value) {
1573     _stack_size_at_create = value;
1574   }
1575 
1576   // Machine dependent stuff
1577 #include OS_CPU_HEADER(thread)
1578 
1579   // JSR166 per-thread parker
1580  private:
1581   Parker _parker;
1582  public:
1583   Parker* parker() { return &_parker; }
1584 
1585   // Biased locking support
1586  private:
1587   GrowableArray<MonitorInfo*>* _cached_monitor_info;
1588  public:
1589   GrowableArray<MonitorInfo*>* cached_monitor_info() { return _cached_monitor_info; }
1590   void set_cached_monitor_info(GrowableArray<MonitorInfo*>* info) { _cached_monitor_info = info; }
1591 
1592   // clearing/querying jni attach status
1593   bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; }
1594   bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
1595   inline void set_done_attaching_via_jni();
1596 
1597   // Stack dump assistance:
1598   // Track the class we want to initialize but for which we have to wait
1599   // on its init_lock() because it is already being initialized.
1600   void set_class_to_be_initialized(InstanceKlass* k);
1601   InstanceKlass* class_to_be_initialized() const;
1602 
1603 private:
1604   InstanceKlass* _class_to_be_initialized;
1605 
1606   // java.lang.Thread.sleep support
1607   ParkEvent * _SleepEvent;
1608 public:
1609   bool sleep(jlong millis);
1610 
1611   // java.lang.Thread interruption support
1612   void interrupt();
1613   bool is_interrupted(bool clear_interrupted);
1614 
1615 private:
1616   LockStack _lock_stack;
1617 
1618 public:
1619   LockStack& lock_stack() { return _lock_stack; }
1620 
1621   static ByteSize lock_stack_offset()      { return byte_offset_of(JavaThread, _lock_stack); }
1622   // Those offsets are used in code generators to access the LockStack that is embedded in this
1623   // JavaThread structure. Those accesses are relative to the current thread, which
1624   // is typically in a dedicated register.
1625   static ByteSize lock_stack_top_offset()  { return lock_stack_offset() + LockStack::top_offset(); }
1626   static ByteSize lock_stack_base_offset() { return lock_stack_offset() + LockStack::base_offset(); }
1627 
1628   static OopStorage* thread_oop_storage();
1629 
1630   static void verify_cross_modify_fence_failure(JavaThread *thread) PRODUCT_RETURN;
1631 
1632   // AsyncGetCallTrace support
1633   inline bool in_asgct(void) {return _in_asgct;}
1634   inline void set_in_asgct(bool value) {_in_asgct = value;}
1635 };
1636 
1637 // Inline implementation of JavaThread::current
1638 inline JavaThread* JavaThread::current() {
1639   return Thread::current()->as_Java_thread();
1640 }
1641 
1642 inline JavaThread* JavaThread::current_or_null() {
1643   Thread* current = Thread::current_or_null();
1644   return current != nullptr ? current->as_Java_thread() : nullptr;
1645 }
1646 
1647 inline JavaThread* Thread::as_Java_thread() {
1648   assert(is_Java_thread(), "incorrect cast to JavaThread");
1649   return static_cast<JavaThread*>(this);
1650 }
1651 
1652 inline const JavaThread* Thread::as_Java_thread() const {
1653   assert(is_Java_thread(), "incorrect cast to const JavaThread");
1654   return static_cast<const JavaThread*>(this);
1655 }
1656 
1657 // The active thread queue. It also keeps track of the current used
1658 // thread priorities.
1659 class Threads: AllStatic {
1660   friend class VMStructs;
1661  private:
1662   static int         _number_of_threads;
1663   static int         _number_of_non_daemon_threads;
1664   static int         _return_code;
1665   static uintx       _thread_claim_token;
1666 #ifdef ASSERT
1667   static bool        _vm_complete;
1668 #endif
1669 
1670   static void initialize_java_lang_classes(JavaThread* main_thread, TRAPS);
1671   static void initialize_jsr292_core_classes(TRAPS);
1672 
1673  public:
1674   // Thread management
1675   // force_daemon is a concession to JNI, where we may need to add a
1676   // thread to the thread list before allocating its thread object
1677   static void add(JavaThread* p, bool force_daemon = false);
1678   static void remove(JavaThread* p, bool is_daemon);
1679   static void non_java_threads_do(ThreadClosure* tc);
1680   static void java_threads_do(ThreadClosure* tc);
1681   static void java_threads_and_vm_thread_do(ThreadClosure* tc);
1682   static void threads_do(ThreadClosure* tc);
1683   static void possibly_parallel_threads_do(bool is_par, ThreadClosure* tc);
1684 
1685   // Initializes the vm and creates the vm thread
1686   static jint create_vm(JavaVMInitArgs* args, bool* canTryAgain);
1687   static void convert_vm_init_libraries_to_agents();
1688   static void create_vm_init_libraries();
1689   static void create_vm_init_agents();
1690   static void shutdown_vm_agents();
1691   static void destroy_vm();
1692   // Supported VM versions via JNI
1693   // Includes JNI_VERSION_1_1
1694   static jboolean is_supported_jni_version_including_1_1(jint version);
1695   // Does not include JNI_VERSION_1_1
1696   static jboolean is_supported_jni_version(jint version);
1697 
1698   // The "thread claim token" provides a way for threads to be claimed
1699   // by parallel worker tasks.
1700   //
1701   // Each thread contains a "token" field. A task will claim the
1702   // thread only if its token is different from the global token,
1703   // which is updated by calling change_thread_claim_token().  When
1704   // a thread is claimed, it's token is set to the global token value
1705   // so other threads in the same iteration pass won't claim it.
1706   //
1707   // For this to work change_thread_claim_token() needs to be called
1708   // exactly once in sequential code before starting parallel tasks
1709   // that should claim threads.
1710   //
1711   // New threads get their token set to 0 and change_thread_claim_token()
1712   // never sets the global token to 0.
1713   static uintx thread_claim_token() { return _thread_claim_token; }
1714   static void change_thread_claim_token();
1715   static void assert_all_threads_claimed() NOT_DEBUG_RETURN;
1716 
1717   // Apply "f->do_oop" to all root oops in all threads.
1718   // This version may only be called by sequential code.
1719   static void oops_do(OopClosure* f, CodeBlobClosure* cf);
1720   // This version may be called by sequential or parallel code.
1721   static void possibly_parallel_oops_do(bool is_par, OopClosure* f, CodeBlobClosure* cf);
1722 
1723   // RedefineClasses support
1724   static void metadata_do(MetadataClosure* f);
1725   static void metadata_handles_do(void f(Metadata*));
1726 
1727 #ifdef ASSERT
1728   static bool is_vm_complete() { return _vm_complete; }
1729 #endif // ASSERT
1730 
1731   // Verification
1732   static void verify();
1733   static void print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks, bool print_extended_info);
1734   static void print(bool print_stacks, bool internal_format) {
1735     // this function is only used by debug.cpp
1736     print_on(tty, print_stacks, internal_format, false /* no concurrent lock printed */, false /* simple format */);
1737   }
1738   static void print_on_error(outputStream* st, Thread* current, char* buf, int buflen);
1739   static void print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
1740                              int buflen, bool* found_current);
1741   static void print_threads_compiling(outputStream* st, char* buf, int buflen, bool short_form = false);
1742 
1743   // Get Java threads that are waiting to enter a monitor.
1744   static GrowableArray<JavaThread*>* get_pending_threads(ThreadsList * t_list,
1745                                                          int count, address monitor);
1746 
1747   // Get owning Java thread from the monitor's owner field.
1748   static JavaThread *owning_thread_from_monitor_owner(ThreadsList * t_list,
1749                                                       address owner);
1750 
1751   static JavaThread* owning_thread_from_object(ThreadsList* t_list, oop obj);
1752   static JavaThread* owning_thread_from_monitor(ThreadsList* t_list, ObjectMonitor* owner);
1753 
1754   // Number of threads on the active threads list
1755   static int number_of_threads()                 { return _number_of_threads; }
1756   // Number of non-daemon threads on the active threads list
1757   static int number_of_non_daemon_threads()      { return _number_of_non_daemon_threads; }
1758 
1759   // Deoptimizes all frames tied to marked nmethods
1760   static void deoptimized_wrt_marked_nmethods();
1761 
1762   struct Test;                  // For private gtest access.
1763 };
1764 
1765 class UnlockFlagSaver {
1766   private:
1767     JavaThread* _thread;
1768     bool _do_not_unlock;
1769   public:
1770     UnlockFlagSaver(JavaThread* t) {
1771       _thread = t;
1772       _do_not_unlock = t->do_not_unlock_if_synchronized();
1773       t->set_do_not_unlock_if_synchronized(false);
1774     }
1775     ~UnlockFlagSaver() {
1776       _thread->set_do_not_unlock_if_synchronized(_do_not_unlock);
1777     }
1778 };
1779 
1780 #endif // SHARE_RUNTIME_THREAD_HPP