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/mutexLocker.hpp"
  40 #include "runtime/os.hpp"
  41 #include "runtime/park.hpp"
  42 #include "runtime/safepointMechanism.hpp"
  43 #include "runtime/stackWatermarkSet.hpp"
  44 #include "runtime/stackOverflow.hpp"
  45 #include "runtime/threadHeapSampler.hpp"
  46 #include "runtime/threadLocalStorage.hpp"
  47 #include "runtime/threadStatisticalInfo.hpp"
  48 #include "runtime/unhandledOops.hpp"
  49 #include "utilities/align.hpp"
  50 #include "utilities/exceptions.hpp"
  51 #include "utilities/globalDefinitions.hpp"
  52 #include "utilities/macros.hpp"
  53 #if INCLUDE_JFR
  54 #include "jfr/support/jfrThreadExtension.hpp"
  55 #endif
  56 
  57 class SafeThreadsListPtr;
  58 class ThreadSafepointState;
  59 class ThreadsList;
  60 class ThreadsSMRSupport;
  61 
  62 class JNIHandleBlock;
  63 class JvmtiRawMonitor;
  64 class JvmtiSampledObjectAllocEventCollector;
  65 class JvmtiThreadState;
  66 class JvmtiVMObjectAllocEventCollector;
  67 class OSThread;
  68 class ThreadStatistics;
  69 class ConcurrentLocksDump;
  70 class MonitorInfo;
  71 
  72 class vframeArray;
  73 class vframe;
  74 class javaVFrame;
  75 
  76 class DeoptResourceMark;
  77 class JvmtiDeferredUpdates;
  78 
  79 class ThreadClosure;
  80 class ICRefillVerifier;
  81 
  82 class Metadata;
  83 class ResourceArea;
  84 
  85 class OopStorage;
  86 
  87 DEBUG_ONLY(class ResourceMark;)
  88 
  89 class WorkerThread;
  90 
  91 class JavaThread;
  92 
  93 // Class hierarchy
  94 // - Thread
  95 //   - JavaThread
  96 //     - various subclasses eg CompilerThread, ServiceThread
  97 //   - NonJavaThread
  98 //     - NamedThread
  99 //       - VMThread
 100 //       - ConcurrentGCThread
 101 //       - WorkerThread
 102 //         - GangWorker
 103 //     - WatcherThread
 104 //     - JfrThreadSampler
 105 //     - LogAsyncWriter
 106 //
 107 // All Thread subclasses must be either JavaThread or NonJavaThread.
 108 // This means !t->is_Java_thread() iff t is a NonJavaThread, or t is
 109 // a partially constructed/destroyed Thread.
 110 
 111 // Thread execution sequence and actions:
 112 // All threads:
 113 //  - thread_native_entry  // per-OS native entry point
 114 //    - stack initialization
 115 //    - other OS-level initialization (signal masks etc)
 116 //    - handshake with creating thread (if not started suspended)
 117 //    - this->call_run()  // common shared entry point
 118 //      - shared common initialization
 119 //      - this->pre_run()  // virtual per-thread-type initialization
 120 //      - this->run()      // virtual per-thread-type "main" logic
 121 //      - shared common tear-down
 122 //      - this->post_run()  // virtual per-thread-type tear-down
 123 //      - // 'this' no longer referenceable
 124 //    - OS-level tear-down (minimal)
 125 //    - final logging
 126 //
 127 // For JavaThread:
 128 //   - this->run()  // virtual but not normally overridden
 129 //     - this->thread_main_inner()  // extra call level to ensure correct stack calculations
 130 //       - this->entry_point()  // set differently for each kind of JavaThread
 131 
 132 class Thread: public ThreadShadow {
 133   friend class VMStructs;
 134   friend class JVMCIVMStructs;
 135  private:
 136 
 137 #ifndef USE_LIBRARY_BASED_TLS_ONLY
 138   // Current thread is maintained as a thread-local variable
 139   static THREAD_LOCAL Thread* _thr_current;
 140 #endif
 141 
 142   // Thread local data area available to the GC. The internal
 143   // structure and contents of this data area is GC-specific.
 144   // Only GC and GC barrier code should access this data area.
 145   GCThreadLocalData _gc_data;
 146 
 147  public:
 148   static ByteSize gc_data_offset() {
 149     return byte_offset_of(Thread, _gc_data);
 150   }
 151 
 152   template <typename T> T* gc_data() {
 153     STATIC_ASSERT(sizeof(T) <= sizeof(_gc_data));
 154     return reinterpret_cast<T*>(&_gc_data);
 155   }
 156 
 157   // Exception handling
 158   // (Note: _pending_exception and friends are in ThreadShadow)
 159   //oop       _pending_exception;                // pending exception for current thread
 160   // const char* _exception_file;                   // file information for exception (debugging only)
 161   // int         _exception_line;                   // line information for exception (debugging only)
 162  protected:
 163 
 164   DEBUG_ONLY(static Thread* _starting_thread;)
 165 
 166   // Support for forcing alignment of thread objects for biased locking
 167   void*       _real_malloc_address;
 168 
 169   // JavaThread lifecycle support:
 170   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
 171   friend class ScanHazardPtrGatherProtectedThreadsClosure;  // for cmpxchg_threads_hazard_ptr(), get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
 172   friend class ScanHazardPtrGatherThreadsListClosure;  // for get_threads_hazard_ptr(), untag_hazard_ptr() access
 173   friend class ScanHazardPtrPrintMatchingThreadsClosure;  // for get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
 174   friend class ThreadsSMRSupport;  // for _nested_threads_hazard_ptr_cnt, _threads_hazard_ptr, _threads_list_ptr access
 175   friend class ThreadsListHandleTest;  // for _nested_threads_hazard_ptr_cnt, _threads_hazard_ptr, _threads_list_ptr access
 176   friend class ValidateHazardPtrsClosure;  // for get_threads_hazard_ptr(), untag_hazard_ptr() access
 177 
 178   ThreadsList* volatile _threads_hazard_ptr;
 179   SafeThreadsListPtr*   _threads_list_ptr;
 180   ThreadsList*          cmpxchg_threads_hazard_ptr(ThreadsList* exchange_value, ThreadsList* compare_value);
 181   ThreadsList*          get_threads_hazard_ptr() const;
 182   void                  set_threads_hazard_ptr(ThreadsList* new_list);
 183   static bool           is_hazard_ptr_tagged(ThreadsList* list) {
 184     return (intptr_t(list) & intptr_t(1)) == intptr_t(1);
 185   }
 186   static ThreadsList*   tag_hazard_ptr(ThreadsList* list) {
 187     return (ThreadsList*)(intptr_t(list) | intptr_t(1));
 188   }
 189   static ThreadsList*   untag_hazard_ptr(ThreadsList* list) {
 190     return (ThreadsList*)(intptr_t(list) & ~intptr_t(1));
 191   }
 192   // This field is enabled via -XX:+EnableThreadSMRStatistics:
 193   uint _nested_threads_hazard_ptr_cnt;
 194   void dec_nested_threads_hazard_ptr_cnt() {
 195     assert(_nested_threads_hazard_ptr_cnt != 0, "mismatched {dec,inc}_nested_threads_hazard_ptr_cnt()");
 196     _nested_threads_hazard_ptr_cnt--;
 197   }
 198   void inc_nested_threads_hazard_ptr_cnt() {
 199     _nested_threads_hazard_ptr_cnt++;
 200   }
 201   uint nested_threads_hazard_ptr_cnt() {
 202     return _nested_threads_hazard_ptr_cnt;
 203   }
 204 
 205  public:
 206   // Is the target JavaThread protected by the calling Thread
 207   // or by some other mechanism:
 208   static bool is_JavaThread_protected(const JavaThread* p);
 209 
 210   void* operator new(size_t size) throw() { return allocate(size, true); }
 211   void* operator new(size_t size, const std::nothrow_t& nothrow_constant) throw() {
 212     return allocate(size, false); }
 213   void  operator delete(void* p);
 214 
 215  protected:
 216   static void* allocate(size_t size, bool throw_excpt, MEMFLAGS flags = mtThread);
 217 
 218  private:
 219   DEBUG_ONLY(bool _suspendible_thread;)
 220 
 221  public:
 222   // Determines if a heap allocation failure will be retried
 223   // (e.g., by deoptimizing and re-executing in the interpreter).
 224   // In this case, the failed allocation must raise
 225   // Universe::out_of_memory_error_retry() and omit side effects
 226   // such as JVMTI events and handling -XX:+HeapDumpOnOutOfMemoryError
 227   // and -XX:OnOutOfMemoryError.
 228   virtual bool in_retryable_allocation() const { return false; }
 229 
 230 #ifdef ASSERT
 231   void set_suspendible_thread() {
 232     _suspendible_thread = true;
 233   }
 234 
 235   void clear_suspendible_thread() {
 236     _suspendible_thread = false;
 237   }
 238 
 239   bool is_suspendible_thread() { return _suspendible_thread; }
 240 #endif
 241 
 242  private:
 243   // Active_handles points to a block of handles
 244   JNIHandleBlock* _active_handles;
 245 
 246   // One-element thread local free list
 247   JNIHandleBlock* _free_handle_block;
 248 
 249   // Point to the last handle mark
 250   HandleMark* _last_handle_mark;
 251 
 252   // Claim value for parallel iteration over threads.
 253   uintx _threads_do_token;
 254 
 255   // Support for GlobalCounter
 256  private:
 257   volatile uintx _rcu_counter;
 258  public:
 259   volatile uintx* get_rcu_counter() {
 260     return &_rcu_counter;
 261   }
 262 
 263  public:
 264   void set_last_handle_mark(HandleMark* mark)   { _last_handle_mark = mark; }
 265   HandleMark* last_handle_mark() const          { return _last_handle_mark; }
 266  private:
 267 
 268 #ifdef ASSERT
 269   ICRefillVerifier* _missed_ic_stub_refill_verifier;
 270 
 271  public:
 272   ICRefillVerifier* missed_ic_stub_refill_verifier() {
 273     return _missed_ic_stub_refill_verifier;
 274   }
 275 
 276   void set_missed_ic_stub_refill_verifier(ICRefillVerifier* verifier) {
 277     _missed_ic_stub_refill_verifier = verifier;
 278   }
 279 #endif // ASSERT
 280 
 281  private:
 282   // Used by SkipGCALot class.
 283   NOT_PRODUCT(bool _skip_gcalot;)               // Should we elide gc-a-lot?
 284 
 285   friend class GCLocker;
 286 
 287  private:
 288   ThreadLocalAllocBuffer _tlab;                 // Thread-local eden
 289   jlong _allocated_bytes;                       // Cumulative number of bytes allocated on
 290                                                 // the Java heap
 291   ThreadHeapSampler _heap_sampler;              // For use when sampling the memory.
 292 
 293   ThreadStatisticalInfo _statistical_info;      // Statistics about the thread
 294 
 295   JFR_ONLY(DEFINE_THREAD_LOCAL_FIELD_JFR;)      // Thread-local data for jfr
 296 
 297   JvmtiRawMonitor* _current_pending_raw_monitor; // JvmtiRawMonitor this thread
 298                                                  // is waiting to lock
 299  public:
 300   // Constructor
 301   Thread();
 302   virtual ~Thread() = 0;        // Thread is abstract.
 303 
 304   // Manage Thread::current()
 305   void initialize_thread_current();
 306   static void clear_thread_current(); // TLS cleanup needed before threads terminate
 307 
 308  protected:
 309   // To be implemented by children.
 310   virtual void run() = 0;
 311   virtual void pre_run() = 0;
 312   virtual void post_run() = 0;  // Note: Thread must not be deleted prior to calling this!
 313 
 314 #ifdef ASSERT
 315   enum RunState {
 316     PRE_CALL_RUN,
 317     CALL_RUN,
 318     PRE_RUN,
 319     RUN,
 320     POST_RUN
 321     // POST_CALL_RUN - can't define this one as 'this' may be deleted when we want to set it
 322   };
 323   RunState _run_state;  // for lifecycle checks
 324 #endif
 325 
 326 
 327  public:
 328   // invokes <ChildThreadClass>::run(), with common preparations and cleanups.
 329   void call_run();
 330 
 331   // Testers
 332   virtual bool is_VM_thread()       const            { return false; }
 333   virtual bool is_Java_thread()     const            { return false; }
 334   virtual bool is_Compiler_thread() const            { return false; }
 335   virtual bool is_Code_cache_sweeper_thread() const  { return false; }
 336   virtual bool is_service_thread() const             { return false; }
 337   virtual bool is_monitor_deflation_thread() const   { return false; }
 338   virtual bool is_hidden_from_external_view() const  { return false; }
 339   virtual bool is_jvmti_agent_thread() const         { return false; }
 340   // True iff the thread can perform GC operations at a safepoint.
 341   // Generally will be true only of VM thread and parallel GC WorkGang
 342   // threads.
 343   virtual bool is_GC_task_thread() const             { return false; }
 344   virtual bool is_Watcher_thread() const             { return false; }
 345   virtual bool is_ConcurrentGC_thread() const        { return false; }
 346   virtual bool is_Named_thread() const               { return false; }
 347   virtual bool is_Worker_thread() const              { return false; }
 348   virtual bool is_JfrSampler_thread() const          { return false; }
 349 
 350   // Can this thread make Java upcalls
 351   virtual bool can_call_java() const                 { return false; }
 352 
 353   // Is this a JavaThread that is on the VM's current ThreadsList?
 354   // If so it must participate in the safepoint protocol.
 355   virtual bool is_active_Java_thread() const         { return false; }
 356 
 357   // Casts
 358   inline JavaThread* as_Java_thread();
 359   inline const JavaThread* as_Java_thread() const;
 360 
 361   virtual char* name() const { return (char*)"Unknown thread"; }
 362 
 363   // Returns the current thread (ASSERTS if NULL)
 364   static inline Thread* current();
 365   // Returns the current thread, or NULL if not attached
 366   static inline Thread* current_or_null();
 367   // Returns the current thread, or NULL if not attached, and is
 368   // safe for use from signal-handlers
 369   static inline Thread* current_or_null_safe();
 370 
 371   // Common thread operations
 372 #ifdef ASSERT
 373   static void check_for_dangling_thread_pointer(Thread *thread);
 374 #endif
 375   static void set_priority(Thread* thread, ThreadPriority priority);
 376   static ThreadPriority get_priority(const Thread* const thread);
 377   static void start(Thread* thread);
 378 
 379   void set_native_thread_name(const char *name) {
 380     assert(Thread::current() == this, "set_native_thread_name can only be called on the current thread");
 381     os::set_native_thread_name(name);
 382   }
 383 
 384   // Support for Unhandled Oop detection
 385   // Add the field for both, fastdebug and debug, builds to keep
 386   // Thread's fields layout the same.
 387   // Note: CHECK_UNHANDLED_OOPS is defined only for fastdebug build.
 388 #ifdef CHECK_UNHANDLED_OOPS
 389  private:
 390   UnhandledOops* _unhandled_oops;
 391 #elif defined(ASSERT)
 392  private:
 393   void* _unhandled_oops;
 394 #endif
 395 #ifdef CHECK_UNHANDLED_OOPS
 396  public:
 397   UnhandledOops* unhandled_oops() { return _unhandled_oops; }
 398   // Mark oop safe for gc.  It may be stack allocated but won't move.
 399   void allow_unhandled_oop(oop *op) {
 400     if (CheckUnhandledOops) unhandled_oops()->allow_unhandled_oop(op);
 401   }
 402   // Clear oops at safepoint so crashes point to unhandled oop violator
 403   void clear_unhandled_oops() {
 404     if (CheckUnhandledOops) unhandled_oops()->clear_unhandled_oops();
 405   }
 406 #endif // CHECK_UNHANDLED_OOPS
 407 
 408  public:
 409 #ifndef PRODUCT
 410   bool skip_gcalot()           { return _skip_gcalot; }
 411   void set_skip_gcalot(bool v) { _skip_gcalot = v;    }
 412 #endif
 413 
 414   // Resource area
 415   ResourceArea* resource_area() const            { return _resource_area; }
 416   void set_resource_area(ResourceArea* area)     { _resource_area = area; }
 417 
 418   OSThread* osthread() const                     { return _osthread;   }
 419   void set_osthread(OSThread* thread)            { _osthread = thread; }
 420 
 421   // JNI handle support
 422   JNIHandleBlock* active_handles() const         { return _active_handles; }
 423   void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
 424   JNIHandleBlock* free_handle_block() const      { return _free_handle_block; }
 425   void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
 426 
 427   // Internal handle support
 428   HandleArea* handle_area() const                { return _handle_area; }
 429   void set_handle_area(HandleArea* area)         { _handle_area = area; }
 430 
 431   GrowableArray<Metadata*>* metadata_handles() const          { return _metadata_handles; }
 432   void set_metadata_handles(GrowableArray<Metadata*>* handles){ _metadata_handles = handles; }
 433 
 434   // Thread-Local Allocation Buffer (TLAB) support
 435   ThreadLocalAllocBuffer& tlab()                 { return _tlab; }
 436   void initialize_tlab();
 437 
 438   jlong allocated_bytes()               { return _allocated_bytes; }
 439   void set_allocated_bytes(jlong value) { _allocated_bytes = value; }
 440   void incr_allocated_bytes(jlong size) { _allocated_bytes += size; }
 441   inline jlong cooked_allocated_bytes();
 442 
 443   ThreadHeapSampler& heap_sampler()     { return _heap_sampler; }
 444 
 445   ThreadStatisticalInfo& statistical_info() { return _statistical_info; }
 446 
 447   JFR_ONLY(DEFINE_THREAD_LOCAL_ACCESSOR_JFR;)
 448 
 449   // For tracking the Jvmti raw monitor the thread is pending on.
 450   JvmtiRawMonitor* current_pending_raw_monitor() {
 451     return _current_pending_raw_monitor;
 452   }
 453   void set_current_pending_raw_monitor(JvmtiRawMonitor* monitor) {
 454     _current_pending_raw_monitor = monitor;
 455   }
 456 
 457   // GC support
 458   // Apply "f->do_oop" to all root oops in "this".
 459   //   Used by JavaThread::oops_do.
 460   // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames
 461   virtual void oops_do_no_frames(OopClosure* f, CodeBlobClosure* cf);
 462   virtual void oops_do_frames(OopClosure* f, CodeBlobClosure* cf) {}
 463   void oops_do(OopClosure* f, CodeBlobClosure* cf);
 464 
 465   // Handles the parallel case for claim_threads_do.
 466  private:
 467   bool claim_par_threads_do(uintx claim_token);
 468  public:
 469   // Requires that "claim_token" is that of the current iteration.
 470   // If "is_par" is false, sets the token of "this" to
 471   // "claim_token", and returns "true".  If "is_par" is true,
 472   // uses an atomic instruction to set the current thread's token to
 473   // "claim_token", if it is not already.  Returns "true" iff the
 474   // calling thread does the update, this indicates that the calling thread
 475   // has claimed the thread in the current iteration.
 476   bool claim_threads_do(bool is_par, uintx claim_token) {
 477     if (!is_par) {
 478       _threads_do_token = claim_token;
 479       return true;
 480     } else {
 481       return claim_par_threads_do(claim_token);
 482     }
 483   }
 484 
 485   uintx threads_do_token() const { return _threads_do_token; }
 486 
 487   // jvmtiRedefineClasses support
 488   void metadata_handles_do(void f(Metadata*));
 489 
 490  private:
 491   // Check if address is within the given range of this thread's
 492   // stack:  stack_base() > adr >/>= limit
 493   // The check is inclusive of limit if passed true, else exclusive.
 494   bool is_in_stack_range(address adr, address limit, bool inclusive) const {
 495     assert(stack_base() > limit && limit >= stack_end(), "limit is outside of stack");
 496     return stack_base() > adr && (inclusive ? adr >= limit : adr > limit);
 497   }
 498 
 499  public:
 500   // Used by fast lock support
 501   virtual bool is_lock_owned(address adr) const;
 502 
 503   // Check if address is within the given range of this thread's
 504   // stack:  stack_base() > adr >= limit
 505   bool is_in_stack_range_incl(address adr, address limit) const {
 506     return is_in_stack_range(adr, limit, true);
 507   }
 508 
 509   // Check if address is within the given range of this thread's
 510   // stack:  stack_base() > adr > limit
 511   bool is_in_stack_range_excl(address adr, address limit) const {
 512     return is_in_stack_range(adr, limit, false);
 513   }
 514 
 515   // Check if address is in the stack mapped to this thread. Used mainly in
 516   // error reporting (so has to include guard zone) and frame printing.
 517   // Expects _stack_base to be initialized - checked with assert.
 518   bool is_in_full_stack_checked(address adr) const {
 519     return is_in_stack_range_incl(adr, stack_end());
 520   }
 521 
 522   // Like is_in_full_stack_checked but without the assertions as this
 523   // may be called in a thread before _stack_base is initialized.
 524   bool is_in_full_stack(address adr) const {
 525     address stack_end = _stack_base - _stack_size;
 526     return _stack_base > adr && adr >= stack_end;
 527   }
 528 
 529   // Check if address is in the live stack of this thread (not just for locks).
 530   // Warning: can only be called by the current thread on itself.
 531   bool is_in_live_stack(address adr) const {
 532     assert(Thread::current() == this, "is_in_live_stack can only be called from current thread");
 533     return is_in_stack_range_incl(adr, os::current_stack_pointer());
 534   }
 535 
 536   // Sets this thread as starting thread. Returns failure if thread
 537   // creation fails due to lack of memory, too many threads etc.
 538   bool set_as_starting_thread();
 539 
 540 protected:
 541   // OS data associated with the thread
 542   OSThread* _osthread;  // Platform-specific thread information
 543 
 544   // Thread local resource area for temporary allocation within the VM
 545   ResourceArea* _resource_area;
 546 
 547   DEBUG_ONLY(ResourceMark* _current_resource_mark;)
 548 
 549   // Thread local handle area for allocation of handles within the VM
 550   HandleArea* _handle_area;
 551   GrowableArray<Metadata*>* _metadata_handles;
 552 
 553   // Support for stack overflow handling, get_thread, etc.
 554   address          _stack_base;
 555   size_t           _stack_size;
 556   int              _lgrp_id;
 557 
 558  public:
 559   // Stack overflow support
 560   address stack_base() const           { assert(_stack_base != NULL,"Sanity check"); return _stack_base; }
 561   void    set_stack_base(address base) { _stack_base = base; }
 562   size_t  stack_size() const           { return _stack_size; }
 563   void    set_stack_size(size_t size)  { _stack_size = size; }
 564   address stack_end()  const           { return stack_base() - stack_size(); }
 565   void    record_stack_base_and_size();
 566   void    register_thread_stack_with_NMT() NOT_NMT_RETURN;
 567   void    unregister_thread_stack_with_NMT() NOT_NMT_RETURN;
 568 
 569   int     lgrp_id() const        { return _lgrp_id; }
 570   void    set_lgrp_id(int value) { _lgrp_id = value; }
 571 
 572   // Printing
 573   void print_on(outputStream* st, bool print_extended_info) const;
 574   virtual void print_on(outputStream* st) const { print_on(st, false); }
 575   void print() const;
 576   virtual void print_on_error(outputStream* st, char* buf, int buflen) const;
 577   void print_value_on(outputStream* st) const;
 578 
 579   // Debug-only code
 580 #ifdef ASSERT
 581  private:
 582   // Deadlock detection support for Mutex locks. List of locks own by thread.
 583   Mutex* _owned_locks;
 584   // Mutex::set_owner_implementation is the only place where _owned_locks is modified,
 585   // thus the friendship
 586   friend class Mutex;
 587   friend class Monitor;
 588 
 589  public:
 590   void print_owned_locks_on(outputStream* st) const;
 591   void print_owned_locks() const                 { print_owned_locks_on(tty);    }
 592   Mutex* owned_locks() const                     { return _owned_locks;          }
 593   bool owns_locks() const                        { return owned_locks() != NULL; }
 594 
 595   // Deadlock detection
 596   ResourceMark* current_resource_mark()          { return _current_resource_mark; }
 597   void set_current_resource_mark(ResourceMark* rm) { _current_resource_mark = rm; }
 598 #endif // ASSERT
 599 
 600  private:
 601   volatile int _jvmti_env_iteration_count;
 602 
 603  public:
 604   void entering_jvmti_env_iteration()            { ++_jvmti_env_iteration_count; }
 605   void leaving_jvmti_env_iteration()             { --_jvmti_env_iteration_count; }
 606   bool is_inside_jvmti_env_iteration()           { return _jvmti_env_iteration_count > 0; }
 607 
 608   // Code generation
 609   static ByteSize exception_file_offset()        { return byte_offset_of(Thread, _exception_file); }
 610   static ByteSize exception_line_offset()        { return byte_offset_of(Thread, _exception_line); }
 611   static ByteSize active_handles_offset()        { return byte_offset_of(Thread, _active_handles); }
 612 
 613   static ByteSize stack_base_offset()            { return byte_offset_of(Thread, _stack_base); }
 614   static ByteSize stack_size_offset()            { return byte_offset_of(Thread, _stack_size); }
 615 
 616   static ByteSize tlab_start_offset()            { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::start_offset(); }
 617   static ByteSize tlab_end_offset()              { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::end_offset(); }
 618   static ByteSize tlab_top_offset()              { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::top_offset(); }
 619   static ByteSize tlab_pf_top_offset()           { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::pf_top_offset(); }
 620 
 621   static ByteSize allocated_bytes_offset()       { return byte_offset_of(Thread, _allocated_bytes); }
 622 
 623   JFR_ONLY(DEFINE_THREAD_LOCAL_OFFSET_JFR;)
 624 
 625  public:
 626   ParkEvent * volatile _ParkEvent;            // for Object monitors, JVMTI raw monitors,
 627                                               // and ObjectSynchronizer::read_stable_mark
 628 
 629   // Termination indicator used by the signal handler.
 630   // _ParkEvent is just a convenient field we can NULL out after setting the JavaThread termination state
 631   // (which can't itself be read from the signal handler if a signal hits during the Thread destructor).
 632   bool has_terminated()                       { return Atomic::load(&_ParkEvent) == NULL; };
 633 
 634   jint _hashStateW;                           // Marsaglia Shift-XOR thread-local RNG
 635   jint _hashStateX;                           // thread-specific hashCode generator state
 636   jint _hashStateY;
 637   jint _hashStateZ;
 638 
 639   // Low-level leaf-lock primitives used to implement synchronization.
 640   // Not for general synchronization use.
 641   static void SpinAcquire(volatile int * Lock, const char * Name);
 642   static void SpinRelease(volatile int * Lock);
 643 
 644 #if defined(__APPLE__) && defined(AARCH64)
 645  private:
 646   DEBUG_ONLY(bool _wx_init);
 647   WXMode _wx_state;
 648  public:
 649   void init_wx();
 650   WXMode enable_wx(WXMode new_state);
 651 
 652   void assert_wx_state(WXMode expected) {
 653     assert(_wx_state == expected, "wrong state");
 654   }
 655 #endif // __APPLE__ && AARCH64
 656 
 657  private:
 658   bool _in_asgct = false;
 659  public:
 660   bool in_asgct() const { return _in_asgct; }
 661   void set_in_asgct(bool value) { _in_asgct = value; }
 662   static bool current_in_asgct() {
 663     Thread *cur = Thread::current_or_null_safe();
 664     return cur != nullptr && cur->in_asgct();
 665   }
 666 };
 667 
 668 class ThreadInAsgct {
 669  private:
 670   Thread* _thread;
 671  public:
 672   ThreadInAsgct(Thread* thread) : _thread(thread) {
 673     assert(thread != nullptr, "invariant");
 674     assert(!thread->in_asgct(), "invariant");
 675     thread->set_in_asgct(true);
 676   }
 677   ~ThreadInAsgct() {
 678     assert(_thread->in_asgct(), "invariant");
 679     _thread->set_in_asgct(false);
 680   }
 681 };
 682 
 683 // Inline implementation of Thread::current()
 684 inline Thread* Thread::current() {
 685   Thread* current = current_or_null();
 686   assert(current != NULL, "Thread::current() called on detached thread");
 687   return current;
 688 }
 689 
 690 inline Thread* Thread::current_or_null() {
 691 #ifndef USE_LIBRARY_BASED_TLS_ONLY
 692   return _thr_current;
 693 #else
 694   if (ThreadLocalStorage::is_initialized()) {
 695     return ThreadLocalStorage::thread();
 696   }
 697   return NULL;
 698 #endif
 699 }
 700 
 701 inline Thread* Thread::current_or_null_safe() {
 702   if (ThreadLocalStorage::is_initialized()) {
 703     return ThreadLocalStorage::thread();
 704   }
 705   return NULL;
 706 }
 707 
 708 class CompilerThread;
 709 
 710 typedef void (*ThreadFunction)(JavaThread*, TRAPS);
 711 
 712 class JavaThread: public Thread {
 713   friend class VMStructs;
 714   friend class JVMCIVMStructs;
 715   friend class WhiteBox;
 716   friend class ThreadsSMRSupport; // to access _threadObj for exiting_threads_oops_do
 717   friend class HandshakeState;
 718  private:
 719   bool           _in_asgct;                      // Is set when this JavaThread is handling ASGCT call
 720   bool           _on_thread_list;                // Is set when this JavaThread is added to the Threads list
 721   OopHandle      _threadObj;                     // The Java level thread object
 722 
 723 #ifdef ASSERT
 724  private:
 725   int _java_call_counter;
 726 
 727  public:
 728   int  java_call_counter()                       { return _java_call_counter; }
 729   void inc_java_call_counter()                   { _java_call_counter++; }
 730   void dec_java_call_counter() {
 731     assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
 732     _java_call_counter--;
 733   }
 734  private:  // restore original namespace restriction
 735 #endif  // ifdef ASSERT
 736 
 737   JavaFrameAnchor _anchor;                       // Encapsulation of current java frame and it state
 738 
 739   ThreadFunction _entry_point;
 740 
 741   JNIEnv        _jni_environment;
 742 
 743   // Deopt support
 744   DeoptResourceMark*  _deopt_mark;               // Holds special ResourceMark for deoptimization
 745 
 746   CompiledMethod*       _deopt_nmethod;         // CompiledMethod that is currently being deoptimized
 747   vframeArray*  _vframe_array_head;              // Holds the heap of the active vframeArrays
 748   vframeArray*  _vframe_array_last;              // Holds last vFrameArray we popped
 749   // Holds updates by JVMTI agents for compiled frames that cannot be performed immediately. They
 750   // will be carried out as soon as possible which, in most cases, is just before deoptimization of
 751   // the frame, when control returns to it.
 752   JvmtiDeferredUpdates* _jvmti_deferred_updates;
 753 
 754   // Handshake value for fixing 6243940. We need a place for the i2c
 755   // adapter to store the callee Method*. This value is NEVER live
 756   // across a gc point so it does NOT have to be gc'd
 757   // The handshake is open ended since we can't be certain that it will
 758   // be NULLed. This is because we rarely ever see the race and end up
 759   // in handle_wrong_method which is the backend of the handshake. See
 760   // code in i2c adapters and handle_wrong_method.
 761 
 762   Method*       _callee_target;
 763 
 764   // Used to pass back results to the interpreter or generated code running Java code.
 765   oop           _vm_result;    // oop result is GC-preserved
 766   Metadata*     _vm_result_2;  // non-oop result
 767 
 768   // See ReduceInitialCardMarks: this holds the precise space interval of
 769   // the most recent slow path allocation for which compiled code has
 770   // elided card-marks for performance along the fast-path.
 771   MemRegion     _deferred_card_mark;
 772 
 773   ObjectMonitor* volatile _current_pending_monitor;     // ObjectMonitor this thread is waiting to lock
 774   bool           _current_pending_monitor_is_from_java; // locking is from Java code
 775   ObjectMonitor* volatile _current_waiting_monitor;     // ObjectMonitor on which this thread called Object.wait()
 776  public:
 777   volatile intptr_t _Stalled;
 778 
 779   // For tracking the heavyweight monitor the thread is pending on.
 780   ObjectMonitor* current_pending_monitor() {
 781     // Use Atomic::load() to prevent data race between concurrent modification and
 782     // concurrent readers, e.g. ThreadService::get_current_contended_monitor().
 783     // Especially, reloading pointer from thread after NULL check must be prevented.
 784     return Atomic::load(&_current_pending_monitor);
 785   }
 786   void set_current_pending_monitor(ObjectMonitor* monitor) {
 787     Atomic::store(&_current_pending_monitor, monitor);
 788   }
 789   void set_current_pending_monitor_is_from_java(bool from_java) {
 790     _current_pending_monitor_is_from_java = from_java;
 791   }
 792   bool current_pending_monitor_is_from_java() {
 793     return _current_pending_monitor_is_from_java;
 794   }
 795   ObjectMonitor* current_waiting_monitor() {
 796     // See the comment in current_pending_monitor() above.
 797     return Atomic::load(&_current_waiting_monitor);
 798   }
 799   void set_current_waiting_monitor(ObjectMonitor* monitor) {
 800     Atomic::store(&_current_waiting_monitor, monitor);
 801   }
 802 
 803  private:
 804   MonitorChunk* _monitor_chunks;              // Contains the off stack monitors
 805                                               // allocated during deoptimization
 806                                               // and by JNI_MonitorEnter/Exit
 807 
 808   enum SuspendFlags {
 809     // NOTE: avoid using the sign-bit as cc generates different test code
 810     //       when the sign-bit is used, and sometimes incorrectly - see CR 6398077
 811     _has_async_exception    = 0x00000001U, // there is a pending async exception
 812     _trace_flag             = 0x00000004U, // call tracing backend
 813     _obj_deopt              = 0x00000008U  // suspend for object reallocation and relocking for JVMTI agent
 814   };
 815 
 816   // various suspension related flags - atomically updated
 817   // overloaded with async exceptions so that we do a single check when transitioning from native->Java
 818   volatile uint32_t _suspend_flags;
 819 
 820   inline void set_suspend_flag(SuspendFlags f);
 821   inline void clear_suspend_flag(SuspendFlags f);
 822 
 823  public:
 824   inline void set_trace_flag();
 825   inline void clear_trace_flag();
 826   inline void set_obj_deopt_flag();
 827   inline void clear_obj_deopt_flag();
 828   bool is_trace_suspend()      { return (_suspend_flags & _trace_flag) != 0; }
 829   bool is_obj_deopt_suspend()  { return (_suspend_flags & _obj_deopt) != 0; }
 830 
 831   // Asynchronous exceptions support
 832  private:
 833   enum AsyncExceptionCondition {
 834     _no_async_condition = 0,
 835     _async_exception,
 836     _async_unsafe_access_error
 837   };
 838   AsyncExceptionCondition _async_exception_condition;
 839   oop                     _pending_async_exception;
 840 
 841   void set_async_exception_condition(AsyncExceptionCondition aec) { _async_exception_condition = aec; }
 842   AsyncExceptionCondition clear_async_exception_condition() {
 843     AsyncExceptionCondition x = _async_exception_condition;
 844     _async_exception_condition = _no_async_condition;
 845     return x;
 846   }
 847 
 848  public:
 849   bool has_async_exception_condition(bool check_unsafe_access_error = true) {
 850     return check_unsafe_access_error ? _async_exception_condition != _no_async_condition
 851                                      : _async_exception_condition == _async_exception;
 852   }
 853   inline void set_pending_async_exception(oop e);
 854   void set_pending_unsafe_access_error()  {
 855     // Don't overwrite an asynchronous exception sent by another thread
 856     if (_async_exception_condition == _no_async_condition) {
 857       set_async_exception_condition(_async_unsafe_access_error);
 858     }
 859   }
 860   void check_and_handle_async_exceptions();
 861   // Installs a pending exception to be inserted later
 862   static void send_async_exception(oop thread_oop, oop java_throwable);
 863   void send_thread_stop(oop throwable);
 864 
 865   // Safepoint support
 866  public:                                                        // Expose _thread_state for SafeFetchInt()
 867   volatile JavaThreadState _thread_state;
 868  private:
 869   SafepointMechanism::ThreadData _poll_data;
 870   ThreadSafepointState*          _safepoint_state;              // Holds information about a thread during a safepoint
 871   address                        _saved_exception_pc;           // Saved pc of instruction where last implicit exception happened
 872   NOT_PRODUCT(bool               _requires_cross_modify_fence;) // State used by VerifyCrossModifyFence
 873 #ifdef ASSERT
 874   // Debug support for checking if code allows safepoints or not.
 875   // Safepoints in the VM can happen because of allocation, invoking a VM operation, or blocking on
 876   // mutex, or blocking on an object synchronizer (Java locking).
 877   // If _no_safepoint_count is non-zero, then an assertion failure will happen in any of
 878   // the above cases. The class NoSafepointVerifier is used to set this counter.
 879   int _no_safepoint_count;                             // If 0, thread allow a safepoint to happen
 880 
 881  public:
 882   void inc_no_safepoint_count() { _no_safepoint_count++; }
 883   void dec_no_safepoint_count() { _no_safepoint_count--; }
 884 #endif // ASSERT
 885  public:
 886   // These functions check conditions before possibly going to a safepoint.
 887   // including NoSafepointVerifier.
 888   void check_for_valid_safepoint_state() NOT_DEBUG_RETURN;
 889   void check_possible_safepoint()        NOT_DEBUG_RETURN;
 890 
 891 #ifdef ASSERT
 892  private:
 893   volatile uint64_t _visited_for_critical_count;
 894 
 895  public:
 896   void set_visited_for_critical_count(uint64_t safepoint_id) {
 897     assert(_visited_for_critical_count == 0, "Must be reset before set");
 898     assert((safepoint_id & 0x1) == 1, "Must be odd");
 899     _visited_for_critical_count = safepoint_id;
 900   }
 901   void reset_visited_for_critical_count(uint64_t safepoint_id) {
 902     assert(_visited_for_critical_count == safepoint_id, "Was not visited");
 903     _visited_for_critical_count = 0;
 904   }
 905   bool was_visited_for_critical_count(uint64_t safepoint_id) const {
 906     return _visited_for_critical_count == safepoint_id;
 907   }
 908 #endif // ASSERT
 909 
 910   // JavaThread termination support
 911  public:
 912   enum TerminatedTypes {
 913     _not_terminated = 0xDEAD - 2,
 914     _thread_exiting,                             // JavaThread::exit() has been called for this thread
 915     _thread_terminated,                          // JavaThread is removed from thread list
 916     _vm_exited                                   // JavaThread is still executing native code, but VM is terminated
 917                                                  // only VM_Exit can set _vm_exited
 918   };
 919 
 920  private:
 921   // In general a JavaThread's _terminated field transitions as follows:
 922   //
 923   //   _not_terminated => _thread_exiting => _thread_terminated
 924   //
 925   // _vm_exited is a special value to cover the case of a JavaThread
 926   // executing native code after the VM itself is terminated.
 927   volatile TerminatedTypes _terminated;
 928 
 929   jint                  _in_deopt_handler;       // count of deoptimization
 930                                                  // handlers thread is in
 931   volatile bool         _doing_unsafe_access;    // Thread may fault due to unsafe access
 932   bool                  _do_not_unlock_if_synchronized;  // Do not unlock the receiver of a synchronized method (since it was
 933                                                          // never locked) when throwing an exception. Used by interpreter only.
 934 
 935   // JNI attach states:
 936   enum JNIAttachStates {
 937     _not_attaching_via_jni = 1,  // thread is not attaching via JNI
 938     _attaching_via_jni,          // thread is attaching via JNI
 939     _attached_via_jni            // thread has attached via JNI
 940   };
 941 
 942   // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
 943   // A native thread that is attaching via JNI starts with a value
 944   // of _attaching_via_jni and transitions to _attached_via_jni.
 945   volatile JNIAttachStates _jni_attach_state;
 946 
 947 
 948 #if INCLUDE_JVMCI
 949   // The _pending_* fields below are used to communicate extra information
 950   // from an uncommon trap in JVMCI compiled code to the uncommon trap handler.
 951 
 952   // Communicates the DeoptReason and DeoptAction of the uncommon trap
 953   int       _pending_deoptimization;
 954 
 955   // Specifies whether the uncommon trap is to bci 0 of a synchronized method
 956   // before the monitor has been acquired.
 957   bool      _pending_monitorenter;
 958 
 959   // Specifies if the DeoptReason for the last uncommon trap was Reason_transfer_to_interpreter
 960   bool      _pending_transfer_to_interpreter;
 961 
 962   // True if in a runtime call from compiled code that will deoptimize
 963   // and re-execute a failed heap allocation in the interpreter.
 964   bool      _in_retryable_allocation;
 965 
 966   // An id of a speculation that JVMCI compiled code can use to further describe and
 967   // uniquely identify the speculative optimization guarded by an uncommon trap.
 968   // See JVMCINMethodData::SPECULATION_LENGTH_BITS for further details.
 969   jlong     _pending_failed_speculation;
 970 
 971   // These fields are mutually exclusive in terms of live ranges.
 972   union {
 973     // Communicates the pc at which the most recent implicit exception occurred
 974     // from the signal handler to a deoptimization stub.
 975     address   _implicit_exception_pc;
 976 
 977     // Communicates an alternative call target to an i2c stub from a JavaCall .
 978     address   _alternate_call_target;
 979   } _jvmci;
 980 
 981   // Support for high precision, thread sensitive counters in JVMCI compiled code.
 982   jlong*    _jvmci_counters;
 983 
 984   // Fast thread locals for use by JVMCI
 985   jlong      _jvmci_reserved0;
 986   jlong      _jvmci_reserved1;
 987   oop        _jvmci_reserved_oop0;
 988 
 989  public:
 990   static jlong* _jvmci_old_thread_counters;
 991   static void collect_counters(jlong* array, int length);
 992 
 993   bool resize_counters(int current_size, int new_size);
 994 
 995   static bool resize_all_jvmci_counters(int new_size);
 996 
 997   void set_jvmci_reserved_oop0(oop value) {
 998     _jvmci_reserved_oop0 = value;
 999   }
1000 
1001   oop get_jvmci_reserved_oop0() {
1002     return _jvmci_reserved_oop0;
1003   }
1004 
1005   void set_jvmci_reserved0(jlong value) {
1006     _jvmci_reserved0 = value;
1007   }
1008 
1009   jlong get_jvmci_reserved0() {
1010     return _jvmci_reserved0;
1011   }
1012 
1013   void set_jvmci_reserved1(jlong value) {
1014     _jvmci_reserved1 = value;
1015   }
1016 
1017   jlong get_jvmci_reserved1() {
1018     return _jvmci_reserved1;
1019   }
1020 
1021  private:
1022 #endif // INCLUDE_JVMCI
1023 
1024   StackOverflow    _stack_overflow_state;
1025 
1026   // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
1027   // used to temp. parsing values into and out of the runtime system during exception handling for compiled
1028   // code)
1029   volatile oop     _exception_oop;               // Exception thrown in compiled code
1030   volatile address _exception_pc;                // PC where exception happened
1031   volatile address _exception_handler_pc;        // PC for handler of exception
1032   volatile int     _is_method_handle_return;     // true (== 1) if the current exception PC is a MethodHandle call site.
1033 
1034  private:
1035   // support for JNI critical regions
1036   jint    _jni_active_critical;                  // count of entries into JNI critical region
1037 
1038   // Checked JNI: function name requires exception check
1039   char* _pending_jni_exception_check_fn;
1040 
1041   // For deadlock detection.
1042   int _depth_first_number;
1043 
1044   // JVMTI PopFrame support
1045   // This is set to popframe_pending to signal that top Java frame should be popped immediately
1046   int _popframe_condition;
1047 
1048   // If reallocation of scalar replaced objects fails, we throw OOM
1049   // and during exception propagation, pop the top
1050   // _frames_to_pop_failed_realloc frames, the ones that reference
1051   // failed reallocations.
1052   int _frames_to_pop_failed_realloc;
1053 
1054   friend class VMThread;
1055   friend class ThreadWaitTransition;
1056   friend class VM_Exit;
1057 
1058   // Stack watermark barriers.
1059   StackWatermarks _stack_watermarks;
1060 
1061  public:
1062   inline StackWatermarks* stack_watermarks() { return &_stack_watermarks; }
1063 
1064  public:
1065   // Constructor
1066   JavaThread();                            // delegating constructor
1067   JavaThread(bool is_attaching_via_jni);   // for main thread and JNI attached threads
1068   JavaThread(ThreadFunction entry_point, size_t stack_size = 0);
1069   ~JavaThread();
1070 
1071 #ifdef ASSERT
1072   // verify this JavaThread hasn't be published in the Threads::list yet
1073   void verify_not_published();
1074 #endif // ASSERT
1075 
1076   StackOverflow* stack_overflow_state() { return &_stack_overflow_state; }
1077 
1078   //JNI functiontable getter/setter for JVMTI jni function table interception API.
1079   void set_jni_functions(struct JNINativeInterface_* functionTable) {
1080     _jni_environment.functions = functionTable;
1081   }
1082   struct JNINativeInterface_* get_jni_functions() {
1083     return (struct JNINativeInterface_ *)_jni_environment.functions;
1084   }
1085 
1086   // This function is called at thread creation to allow
1087   // platform specific thread variables to be initialized.
1088   void cache_global_variables();
1089 
1090   // Executes Shutdown.shutdown()
1091   void invoke_shutdown_hooks();
1092 
1093   // Cleanup on thread exit
1094   enum ExitType {
1095     normal_exit,
1096     jni_detach
1097   };
1098   void exit(bool destroy_vm, ExitType exit_type = normal_exit);
1099 
1100   void cleanup_failed_attach_current_thread(bool is_daemon);
1101 
1102   // Testers
1103   virtual bool is_Java_thread() const            { return true;  }
1104   virtual bool can_call_java() const             { return true; }
1105 
1106   virtual bool is_active_Java_thread() const {
1107     return on_thread_list() && !is_terminated();
1108   }
1109 
1110   // Thread oop. threadObj() can be NULL for initial JavaThread
1111   // (or for threads attached via JNI)
1112   oop threadObj() const;
1113   void set_threadObj(oop p);
1114 
1115   // Prepare thread and add to priority queue.  If a priority is
1116   // not specified, use the priority of the thread object. Threads_lock
1117   // must be held while this function is called.
1118   void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
1119 
1120   void set_saved_exception_pc(address pc)        { _saved_exception_pc = pc; }
1121   address saved_exception_pc()                   { return _saved_exception_pc; }
1122 
1123   ThreadFunction entry_point() const             { return _entry_point; }
1124 
1125   // Allocates a new Java level thread object for this thread. thread_name may be NULL.
1126   void allocate_threadObj(Handle thread_group, const char* thread_name, bool daemon, TRAPS);
1127 
1128   // Last frame anchor routines
1129 
1130   JavaFrameAnchor* frame_anchor(void)            { return &_anchor; }
1131 
1132   // last_Java_sp
1133   bool has_last_Java_frame() const               { return _anchor.has_last_Java_frame(); }
1134   intptr_t* last_Java_sp() const                 { return _anchor.last_Java_sp(); }
1135 
1136   // last_Java_pc
1137 
1138   address last_Java_pc(void)                     { return _anchor.last_Java_pc(); }
1139 
1140   // Safepoint support
1141   inline JavaThreadState thread_state() const;
1142   inline void set_thread_state(JavaThreadState s);
1143   inline void set_thread_state_fence(JavaThreadState s);  // fence after setting thread state
1144   inline ThreadSafepointState* safepoint_state() const;
1145   inline void set_safepoint_state(ThreadSafepointState* state);
1146   inline bool is_at_poll_safepoint();
1147 
1148   // JavaThread termination and lifecycle support:
1149   void smr_delete();
1150   bool on_thread_list() const { return _on_thread_list; }
1151   void set_on_thread_list() { _on_thread_list = true; }
1152 
1153   // thread has called JavaThread::exit() or is terminated
1154   bool is_exiting() const;
1155   // thread is terminated (no longer on the threads list); we compare
1156   // against the two non-terminated values so that a freed JavaThread
1157   // will also be considered terminated.
1158   bool check_is_terminated(TerminatedTypes l_terminated) const {
1159     return l_terminated != _not_terminated && l_terminated != _thread_exiting;
1160   }
1161   bool is_terminated() const;
1162   void set_terminated(TerminatedTypes t);
1163 
1164   void block_if_vm_exited();
1165 
1166   bool doing_unsafe_access()                     { return _doing_unsafe_access; }
1167   void set_doing_unsafe_access(bool val)         { _doing_unsafe_access = val; }
1168 
1169   bool do_not_unlock_if_synchronized()             { return _do_not_unlock_if_synchronized; }
1170   void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
1171 
1172   SafepointMechanism::ThreadData* poll_data() { return &_poll_data; }
1173 
1174   void set_requires_cross_modify_fence(bool val) PRODUCT_RETURN NOT_PRODUCT({ _requires_cross_modify_fence = val; })
1175 
1176  private:
1177   DEBUG_ONLY(void verify_frame_info();)
1178 
1179   // Support for thread handshake operations
1180   HandshakeState _handshake;
1181  public:
1182   HandshakeState* handshake_state() { return &_handshake; }
1183 
1184   // A JavaThread can always safely operate on it self and other threads
1185   // can do it safely if they are the active handshaker.
1186   bool is_handshake_safe_for(Thread* th) const {
1187     return _handshake.active_handshaker() == th || this == th;
1188   }
1189 
1190   // Suspend/resume support for JavaThread
1191   bool java_suspend(); // higher-level suspension logic called by the public APIs
1192   bool java_resume();  // higher-level resume logic called by the public APIs
1193   bool is_suspended()     { return _handshake.is_suspended(); }
1194 
1195   // Check for async exception in addition to safepoint.
1196   static void check_special_condition_for_native_trans(JavaThread *thread);
1197 
1198   // Synchronize with another thread that is deoptimizing objects of the
1199   // current thread, i.e. reverts optimizations based on escape analysis.
1200   void wait_for_object_deoptimization();
1201 
1202   // these next two are also used for self-suspension and async exception support
1203   void handle_special_runtime_exit_condition(bool check_asyncs = true);
1204 
1205   // Return true if JavaThread has an asynchronous condition or
1206   // if external suspension is requested.
1207   bool has_special_runtime_exit_condition() {
1208     return (_async_exception_condition != _no_async_condition) ||
1209            (_suspend_flags & (_obj_deopt JFR_ONLY(| _trace_flag))) != 0;
1210   }
1211 
1212   // Fast-locking support
1213   bool is_lock_owned(address adr) const;
1214 
1215   // Accessors for vframe array top
1216   // The linked list of vframe arrays are sorted on sp. This means when we
1217   // unpack the head must contain the vframe array to unpack.
1218   void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
1219   vframeArray* vframe_array_head() const         { return _vframe_array_head;  }
1220 
1221   // Side structure for deferring update of java frame locals until deopt occurs
1222   JvmtiDeferredUpdates* deferred_updates() const      { return _jvmti_deferred_updates; }
1223   void set_deferred_updates(JvmtiDeferredUpdates* du) { _jvmti_deferred_updates = du; }
1224 
1225   // These only really exist to make debugging deopt problems simpler
1226 
1227   void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
1228   vframeArray* vframe_array_last() const         { return _vframe_array_last;  }
1229 
1230   // The special resourceMark used during deoptimization
1231 
1232   void set_deopt_mark(DeoptResourceMark* value)  { _deopt_mark = value; }
1233   DeoptResourceMark* deopt_mark(void)            { return _deopt_mark; }
1234 
1235   void set_deopt_compiled_method(CompiledMethod* nm)  { _deopt_nmethod = nm; }
1236   CompiledMethod* deopt_compiled_method()        { return _deopt_nmethod; }
1237 
1238   Method*    callee_target() const               { return _callee_target; }
1239   void set_callee_target  (Method* x)          { _callee_target   = x; }
1240 
1241   // Oop results of vm runtime calls
1242   oop  vm_result() const                         { return _vm_result; }
1243   void set_vm_result  (oop x)                    { _vm_result   = x; }
1244 
1245   Metadata*    vm_result_2() const               { return _vm_result_2; }
1246   void set_vm_result_2  (Metadata* x)          { _vm_result_2   = x; }
1247 
1248   MemRegion deferred_card_mark() const           { return _deferred_card_mark; }
1249   void set_deferred_card_mark(MemRegion mr)      { _deferred_card_mark = mr;   }
1250 
1251 #if INCLUDE_JVMCI
1252   int  pending_deoptimization() const             { return _pending_deoptimization; }
1253   jlong pending_failed_speculation() const        { return _pending_failed_speculation; }
1254   bool has_pending_monitorenter() const           { return _pending_monitorenter; }
1255   void set_pending_monitorenter(bool b)           { _pending_monitorenter = b; }
1256   void set_pending_deoptimization(int reason)     { _pending_deoptimization = reason; }
1257   void set_pending_failed_speculation(jlong failed_speculation) { _pending_failed_speculation = failed_speculation; }
1258   void set_pending_transfer_to_interpreter(bool b) { _pending_transfer_to_interpreter = b; }
1259   void set_jvmci_alternate_call_target(address a) { assert(_jvmci._alternate_call_target == NULL, "must be"); _jvmci._alternate_call_target = a; }
1260   void set_jvmci_implicit_exception_pc(address a) { assert(_jvmci._implicit_exception_pc == NULL, "must be"); _jvmci._implicit_exception_pc = a; }
1261 
1262   virtual bool in_retryable_allocation() const    { return _in_retryable_allocation; }
1263   void set_in_retryable_allocation(bool b)        { _in_retryable_allocation = b; }
1264 #endif // INCLUDE_JVMCI
1265 
1266   // Exception handling for compiled methods
1267   oop      exception_oop() const;
1268   address  exception_pc() const                  { return _exception_pc; }
1269   address  exception_handler_pc() const          { return _exception_handler_pc; }
1270   bool     is_method_handle_return() const       { return _is_method_handle_return == 1; }
1271 
1272   void set_exception_oop(oop o);
1273   void set_exception_pc(address a)               { _exception_pc = a; }
1274   void set_exception_handler_pc(address a)       { _exception_handler_pc = a; }
1275   void set_is_method_handle_return(bool value)   { _is_method_handle_return = value ? 1 : 0; }
1276 
1277   void clear_exception_oop_and_pc() {
1278     set_exception_oop(NULL);
1279     set_exception_pc(NULL);
1280   }
1281 
1282   // Check if address is in the usable part of the stack (excludes protected
1283   // guard pages). Can be applied to any thread and is an approximation for
1284   // using is_in_live_stack when the query has to happen from another thread.
1285   bool is_in_usable_stack(address adr) const {
1286     return is_in_stack_range_incl(adr, _stack_overflow_state.stack_reserved_zone_base());
1287   }
1288 
1289   // Misc. accessors/mutators
1290   void set_do_not_unlock(void)                   { _do_not_unlock_if_synchronized = true; }
1291   void clr_do_not_unlock(void)                   { _do_not_unlock_if_synchronized = false; }
1292   bool do_not_unlock(void)                       { return _do_not_unlock_if_synchronized; }
1293 
1294   // For assembly stub generation
1295   static ByteSize threadObj_offset()             { return byte_offset_of(JavaThread, _threadObj); }
1296   static ByteSize jni_environment_offset()       { return byte_offset_of(JavaThread, _jni_environment); }
1297   static ByteSize pending_jni_exception_check_fn_offset() {
1298     return byte_offset_of(JavaThread, _pending_jni_exception_check_fn);
1299   }
1300   static ByteSize last_Java_sp_offset() {
1301     return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
1302   }
1303   static ByteSize last_Java_pc_offset() {
1304     return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
1305   }
1306   static ByteSize frame_anchor_offset() {
1307     return byte_offset_of(JavaThread, _anchor);
1308   }
1309   static ByteSize callee_target_offset()         { return byte_offset_of(JavaThread, _callee_target); }
1310   static ByteSize vm_result_offset()             { return byte_offset_of(JavaThread, _vm_result); }
1311   static ByteSize vm_result_2_offset()           { return byte_offset_of(JavaThread, _vm_result_2); }
1312   static ByteSize thread_state_offset()          { return byte_offset_of(JavaThread, _thread_state); }
1313   static ByteSize polling_word_offset()          { return byte_offset_of(JavaThread, _poll_data) + byte_offset_of(SafepointMechanism::ThreadData, _polling_word);}
1314   static ByteSize polling_page_offset()          { return byte_offset_of(JavaThread, _poll_data) + byte_offset_of(SafepointMechanism::ThreadData, _polling_page);}
1315   static ByteSize saved_exception_pc_offset()    { return byte_offset_of(JavaThread, _saved_exception_pc); }
1316   static ByteSize osthread_offset()              { return byte_offset_of(JavaThread, _osthread); }
1317 #if INCLUDE_JVMCI
1318   static ByteSize pending_deoptimization_offset() { return byte_offset_of(JavaThread, _pending_deoptimization); }
1319   static ByteSize pending_monitorenter_offset()  { return byte_offset_of(JavaThread, _pending_monitorenter); }
1320   static ByteSize pending_failed_speculation_offset() { return byte_offset_of(JavaThread, _pending_failed_speculation); }
1321   static ByteSize jvmci_alternate_call_target_offset() { return byte_offset_of(JavaThread, _jvmci._alternate_call_target); }
1322   static ByteSize jvmci_implicit_exception_pc_offset() { return byte_offset_of(JavaThread, _jvmci._implicit_exception_pc); }
1323   static ByteSize jvmci_counters_offset()        { return byte_offset_of(JavaThread, _jvmci_counters); }
1324 #endif // INCLUDE_JVMCI
1325   static ByteSize exception_oop_offset()         { return byte_offset_of(JavaThread, _exception_oop); }
1326   static ByteSize exception_pc_offset()          { return byte_offset_of(JavaThread, _exception_pc); }
1327   static ByteSize exception_handler_pc_offset()  { return byte_offset_of(JavaThread, _exception_handler_pc); }
1328   static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); }
1329 
1330   // StackOverflow offsets
1331   static ByteSize stack_overflow_limit_offset()  {
1332     return byte_offset_of(JavaThread, _stack_overflow_state._stack_overflow_limit);
1333   }
1334   static ByteSize stack_guard_state_offset()     {
1335     return byte_offset_of(JavaThread, _stack_overflow_state._stack_guard_state);
1336   }
1337   static ByteSize reserved_stack_activation_offset() {
1338     return byte_offset_of(JavaThread, _stack_overflow_state._reserved_stack_activation);
1339   }
1340 
1341   static ByteSize suspend_flags_offset()         { return byte_offset_of(JavaThread, _suspend_flags); }
1342 
1343   static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
1344   static ByteSize should_post_on_exceptions_flag_offset() {
1345     return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
1346   }
1347   static ByteSize doing_unsafe_access_offset() { return byte_offset_of(JavaThread, _doing_unsafe_access); }
1348   NOT_PRODUCT(static ByteSize requires_cross_modify_fence_offset()  { return byte_offset_of(JavaThread, _requires_cross_modify_fence); })
1349 
1350   // Returns the jni environment for this thread
1351   JNIEnv* jni_environment()                      { return &_jni_environment; }
1352 
1353   static JavaThread* thread_from_jni_environment(JNIEnv* env) {
1354     JavaThread *thread_from_jni_env = (JavaThread*)((intptr_t)env - in_bytes(jni_environment_offset()));
1355     // Only return NULL if thread is off the thread list; starting to
1356     // exit should not return NULL.
1357     if (thread_from_jni_env->is_terminated()) {
1358       thread_from_jni_env->block_if_vm_exited();
1359       return NULL;
1360     } else {
1361       return thread_from_jni_env;
1362     }
1363   }
1364 
1365   // JNI critical regions. These can nest.
1366   bool in_critical()    { return _jni_active_critical > 0; }
1367   bool in_last_critical()  { return _jni_active_critical == 1; }
1368   inline void enter_critical();
1369   void exit_critical() {
1370     assert(Thread::current() == this, "this must be current thread");
1371     _jni_active_critical--;
1372     assert(_jni_active_critical >= 0, "JNI critical nesting problem?");
1373   }
1374 
1375   // Checked JNI: is the programmer required to check for exceptions, if so specify
1376   // which function name. Returning to a Java frame should implicitly clear the
1377   // pending check, this is done for Native->Java transitions (i.e. user JNI code).
1378   // VM->Java transistions are not cleared, it is expected that JNI code enclosed
1379   // within ThreadToNativeFromVM makes proper exception checks (i.e. VM internal).
1380   bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != NULL; }
1381   void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = NULL; }
1382   const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; }
1383   void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; }
1384 
1385   // For deadlock detection
1386   int depth_first_number() { return _depth_first_number; }
1387   void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
1388 
1389  private:
1390   void set_monitor_chunks(MonitorChunk* monitor_chunks) { _monitor_chunks = monitor_chunks; }
1391 
1392  public:
1393   MonitorChunk* monitor_chunks() const           { return _monitor_chunks; }
1394   void add_monitor_chunk(MonitorChunk* chunk);
1395   void remove_monitor_chunk(MonitorChunk* chunk);
1396   bool in_deopt_handler() const                  { return _in_deopt_handler > 0; }
1397   void inc_in_deopt_handler()                    { _in_deopt_handler++; }
1398   void dec_in_deopt_handler() {
1399     assert(_in_deopt_handler > 0, "mismatched deopt nesting");
1400     if (_in_deopt_handler > 0) { // robustness
1401       _in_deopt_handler--;
1402     }
1403   }
1404 
1405  private:
1406   void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
1407 
1408  public:
1409 
1410   // Frame iteration; calls the function f for all frames on the stack
1411   void frames_do(void f(frame*, const RegisterMap*));
1412 
1413   // Memory operations
1414   void oops_do_frames(OopClosure* f, CodeBlobClosure* cf);
1415   void oops_do_no_frames(OopClosure* f, CodeBlobClosure* cf);
1416 
1417   // Sweeper operations
1418   virtual void nmethods_do(CodeBlobClosure* cf);
1419 
1420   // RedefineClasses Support
1421   void metadata_do(MetadataClosure* f);
1422 
1423   // Debug method asserting thread states are correct during a handshake operation.
1424   DEBUG_ONLY(void verify_states_for_handshake();)
1425 
1426   // Misc. operations
1427   char* name() const { return (char*)get_thread_name(); }
1428   static const char* name_for(oop thread_obj);
1429   void print_on(outputStream* st, bool print_extended_info) const;
1430   void print_on(outputStream* st) const { print_on(st, false); }
1431   void print() const;
1432   void print_thread_state_on(outputStream*) const      PRODUCT_RETURN;
1433   void print_on_error(outputStream* st, char* buf, int buflen) const;
1434   void print_name_on_error(outputStream* st, char* buf, int buflen) const;
1435   void verify();
1436   const char* get_thread_name() const;
1437  protected:
1438   // factor out low-level mechanics for use in both normal and error cases
1439   virtual const char* get_thread_name_string(char* buf = NULL, int buflen = 0) const;
1440  public:
1441   // Accessing frames
1442   frame last_frame() {
1443     _anchor.make_walkable();
1444     return pd_last_frame();
1445   }
1446   javaVFrame* last_java_vframe(RegisterMap* reg_map);
1447 
1448   // Returns method at 'depth' java or native frames down the stack
1449   // Used for security checks
1450   Klass* security_get_caller_class(int depth);
1451 
1452   // Print stack trace in external format
1453   void print_stack_on(outputStream* st);
1454   void print_stack() { print_stack_on(tty); }
1455   // Print current stack trace for checked JNI warnings and JNI fatal errors.
1456   // This is the external format from above, but selecting the platform
1457   // as applicable.
1458   void print_jni_stack();
1459 
1460   // Print stack traces in various internal formats
1461   void trace_stack()                             PRODUCT_RETURN;
1462   void trace_stack_from(vframe* start_vf)        PRODUCT_RETURN;
1463   void trace_frames()                            PRODUCT_RETURN;
1464 
1465   // Print an annotated view of the stack frames
1466   void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN;
1467   void validate_frame_layout() {
1468     print_frame_layout(0, true);
1469   }
1470 
1471   // Function for testing deoptimization
1472   void deoptimize();
1473   void make_zombies();
1474 
1475   void deoptimize_marked_methods();
1476 
1477  public:
1478   // Returns the running thread as a JavaThread
1479   static inline JavaThread* current();
1480   // Returns the current thread as a JavaThread, or NULL if not attached
1481   static inline JavaThread* current_or_null();
1482 
1483   // Returns the active Java thread.  Do not use this if you know you are calling
1484   // from a JavaThread, as it's slower than JavaThread::current.  If called from
1485   // the VMThread, it also returns the JavaThread that instigated the VMThread's
1486   // operation.  You may not want that either.
1487   static JavaThread* active();
1488 
1489  protected:
1490   virtual void pre_run();
1491   virtual void run();
1492   void thread_main_inner();
1493   virtual void post_run();
1494 
1495  public:
1496   // Thread local information maintained by JVMTI.
1497   void set_jvmti_thread_state(JvmtiThreadState *value)                           { _jvmti_thread_state = value; }
1498   // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1499   // getter is used to get this JavaThread's JvmtiThreadState if it has
1500   // one which means NULL can be returned. JvmtiThreadState::state_for()
1501   // is used to get the specified JavaThread's JvmtiThreadState if it has
1502   // one or it allocates a new JvmtiThreadState for the JavaThread and
1503   // returns it. JvmtiThreadState::state_for() will return NULL only if
1504   // the specified JavaThread is exiting.
1505   JvmtiThreadState *jvmti_thread_state() const                                   { return _jvmti_thread_state; }
1506   static ByteSize jvmti_thread_state_offset()                                    { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1507 
1508   // JVMTI PopFrame support
1509   // Setting and clearing popframe_condition
1510   // All of these enumerated values are bits. popframe_pending
1511   // indicates that a PopFrame() has been requested and not yet been
1512   // completed. popframe_processing indicates that that PopFrame() is in
1513   // the process of being completed. popframe_force_deopt_reexecution_bit
1514   // indicates that special handling is required when returning to a
1515   // deoptimized caller.
1516   enum PopCondition {
1517     popframe_inactive                      = 0x00,
1518     popframe_pending_bit                   = 0x01,
1519     popframe_processing_bit                = 0x02,
1520     popframe_force_deopt_reexecution_bit   = 0x04
1521   };
1522   PopCondition popframe_condition()                   { return (PopCondition) _popframe_condition; }
1523   void set_popframe_condition(PopCondition c)         { _popframe_condition = c; }
1524   void set_popframe_condition_bit(PopCondition c)     { _popframe_condition |= c; }
1525   void clear_popframe_condition()                     { _popframe_condition = popframe_inactive; }
1526   static ByteSize popframe_condition_offset()         { return byte_offset_of(JavaThread, _popframe_condition); }
1527   bool has_pending_popframe()                         { return (popframe_condition() & popframe_pending_bit) != 0; }
1528   bool popframe_forcing_deopt_reexecution()           { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
1529   void clear_popframe_forcing_deopt_reexecution()     { _popframe_condition &= ~popframe_force_deopt_reexecution_bit; }
1530 
1531   bool pop_frame_in_process(void)                     { return ((_popframe_condition & popframe_processing_bit) != 0); }
1532   void set_pop_frame_in_process(void)                 { _popframe_condition |= popframe_processing_bit; }
1533   void clr_pop_frame_in_process(void)                 { _popframe_condition &= ~popframe_processing_bit; }
1534 
1535   int frames_to_pop_failed_realloc() const            { return _frames_to_pop_failed_realloc; }
1536   void set_frames_to_pop_failed_realloc(int nb)       { _frames_to_pop_failed_realloc = nb; }
1537   void dec_frames_to_pop_failed_realloc()             { _frames_to_pop_failed_realloc--; }
1538 
1539  private:
1540   // Saved incoming arguments to popped frame.
1541   // Used only when popped interpreted frame returns to deoptimized frame.
1542   void*    _popframe_preserved_args;
1543   int      _popframe_preserved_args_size;
1544 
1545  public:
1546   void  popframe_preserve_args(ByteSize size_in_bytes, void* start);
1547   void* popframe_preserved_args();
1548   ByteSize popframe_preserved_args_size();
1549   WordSize popframe_preserved_args_size_in_words();
1550   void  popframe_free_preserved_args();
1551 
1552 
1553  private:
1554   JvmtiThreadState *_jvmti_thread_state;
1555 
1556   // Used by the interpreter in fullspeed mode for frame pop, method
1557   // entry, method exit and single stepping support. This field is
1558   // only set to non-zero at a safepoint or using a direct handshake
1559   // (see EnterInterpOnlyModeClosure).
1560   // It can be set to zero asynchronously to this threads execution (i.e., without
1561   // safepoint/handshake or a lock) so we have to be very careful.
1562   // Accesses by other threads are synchronized using JvmtiThreadState_lock though.
1563   int               _interp_only_mode;
1564 
1565  public:
1566   // used by the interpreter for fullspeed debugging support (see above)
1567   static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
1568   bool is_interp_only_mode()                { return (_interp_only_mode != 0); }
1569   int get_interp_only_mode()                { return _interp_only_mode; }
1570   void increment_interp_only_mode()         { ++_interp_only_mode; }
1571   void decrement_interp_only_mode()         { --_interp_only_mode; }
1572 
1573   // support for cached flag that indicates whether exceptions need to be posted for this thread
1574   // if this is false, we can avoid deoptimizing when events are thrown
1575   // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
1576  private:
1577   int    _should_post_on_exceptions_flag;
1578 
1579  public:
1580   int   should_post_on_exceptions_flag()  { return _should_post_on_exceptions_flag; }
1581   void  set_should_post_on_exceptions_flag(int val)  { _should_post_on_exceptions_flag = val; }
1582 
1583  private:
1584   ThreadStatistics *_thread_stat;
1585 
1586  public:
1587   ThreadStatistics* get_thread_stat() const    { return _thread_stat; }
1588 
1589   // Return a blocker object for which this thread is blocked parking.
1590   oop current_park_blocker();
1591 
1592  private:
1593   static size_t _stack_size_at_create;
1594 
1595  public:
1596   static inline size_t stack_size_at_create(void) {
1597     return _stack_size_at_create;
1598   }
1599   static inline void set_stack_size_at_create(size_t value) {
1600     _stack_size_at_create = value;
1601   }
1602 
1603   // Machine dependent stuff
1604 #include OS_CPU_HEADER(thread)
1605 
1606   // JSR166 per-thread parker
1607  private:
1608   Parker _parker;
1609  public:
1610   Parker* parker() { return &_parker; }
1611 
1612   // Biased locking support
1613  private:
1614   GrowableArray<MonitorInfo*>* _cached_monitor_info;
1615  public:
1616   GrowableArray<MonitorInfo*>* cached_monitor_info() { return _cached_monitor_info; }
1617   void set_cached_monitor_info(GrowableArray<MonitorInfo*>* info) { _cached_monitor_info = info; }
1618 
1619   // clearing/querying jni attach status
1620   bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; }
1621   bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
1622   inline void set_done_attaching_via_jni();
1623 
1624   // Stack dump assistance:
1625   // Track the class we want to initialize but for which we have to wait
1626   // on its init_lock() because it is already being initialized.
1627   void set_class_to_be_initialized(InstanceKlass* k);
1628   InstanceKlass* class_to_be_initialized() const;
1629 
1630 private:
1631   InstanceKlass* _class_to_be_initialized;
1632 
1633   // java.lang.Thread.sleep support
1634   ParkEvent * _SleepEvent;
1635 public:
1636   bool sleep(jlong millis);
1637 
1638   // java.lang.Thread interruption support
1639   void interrupt();
1640   bool is_interrupted(bool clear_interrupted);
1641 
1642   static OopStorage* thread_oop_storage();
1643 
1644   static void verify_cross_modify_fence_failure(JavaThread *thread) PRODUCT_RETURN;
1645 
1646   // Helper function to start a VM-internal daemon thread.
1647   // E.g. ServiceThread, NotificationThread, CompilerThread etc.
1648   static void start_internal_daemon(JavaThread* current, JavaThread* target,
1649                                     Handle thread_oop, ThreadPriority prio);
1650 
1651   // Helper function to do vm_exit_on_initialization for osthread
1652   // resource allocation failure.
1653   static void vm_exit_on_osthread_failure(JavaThread* thread);
1654 
1655   // AsyncGetCallTrace support
1656   inline bool in_asgct(void) {return _in_asgct;}
1657   inline void set_in_asgct(bool value) {_in_asgct = value;}
1658 };
1659 
1660 // Inline implementation of JavaThread::current
1661 inline JavaThread* JavaThread::current() {
1662   return Thread::current()->as_Java_thread();
1663 }
1664 
1665 inline JavaThread* JavaThread::current_or_null() {
1666   Thread* current = Thread::current_or_null();
1667   return current != nullptr ? current->as_Java_thread() : nullptr;
1668 }
1669 
1670 inline JavaThread* Thread::as_Java_thread() {
1671   assert(is_Java_thread(), "incorrect cast to JavaThread");
1672   return static_cast<JavaThread*>(this);
1673 }
1674 
1675 inline const JavaThread* Thread::as_Java_thread() const {
1676   assert(is_Java_thread(), "incorrect cast to const JavaThread");
1677   return static_cast<const JavaThread*>(this);
1678 }
1679 
1680 // The active thread queue. It also keeps track of the current used
1681 // thread priorities.
1682 class Threads: AllStatic {
1683   friend class VMStructs;
1684  private:
1685   static int         _number_of_threads;
1686   static int         _number_of_non_daemon_threads;
1687   static int         _return_code;
1688   static uintx       _thread_claim_token;
1689 #ifdef ASSERT
1690   static bool        _vm_complete;
1691 #endif
1692 
1693   static void initialize_java_lang_classes(JavaThread* main_thread, TRAPS);
1694   static void initialize_jsr292_core_classes(TRAPS);
1695 
1696  public:
1697   // Thread management
1698   // force_daemon is a concession to JNI, where we may need to add a
1699   // thread to the thread list before allocating its thread object
1700   static void add(JavaThread* p, bool force_daemon = false);
1701   static void remove(JavaThread* p, bool is_daemon);
1702   static void non_java_threads_do(ThreadClosure* tc);
1703   static void java_threads_do(ThreadClosure* tc);
1704   static void java_threads_and_vm_thread_do(ThreadClosure* tc);
1705   static void threads_do(ThreadClosure* tc);
1706   static void possibly_parallel_threads_do(bool is_par, ThreadClosure* tc);
1707 
1708   // Initializes the vm and creates the vm thread
1709   static jint create_vm(JavaVMInitArgs* args, bool* canTryAgain);
1710   static void convert_vm_init_libraries_to_agents();
1711   static void create_vm_init_libraries();
1712   static void create_vm_init_agents();
1713   static void shutdown_vm_agents();
1714   static void destroy_vm();
1715   // Supported VM versions via JNI
1716   // Includes JNI_VERSION_1_1
1717   static jboolean is_supported_jni_version_including_1_1(jint version);
1718   // Does not include JNI_VERSION_1_1
1719   static jboolean is_supported_jni_version(jint version);
1720 
1721   // The "thread claim token" provides a way for threads to be claimed
1722   // by parallel worker tasks.
1723   //
1724   // Each thread contains a "token" field. A task will claim the
1725   // thread only if its token is different from the global token,
1726   // which is updated by calling change_thread_claim_token().  When
1727   // a thread is claimed, it's token is set to the global token value
1728   // so other threads in the same iteration pass won't claim it.
1729   //
1730   // For this to work change_thread_claim_token() needs to be called
1731   // exactly once in sequential code before starting parallel tasks
1732   // that should claim threads.
1733   //
1734   // New threads get their token set to 0 and change_thread_claim_token()
1735   // never sets the global token to 0.
1736   static uintx thread_claim_token() { return _thread_claim_token; }
1737   static void change_thread_claim_token();
1738   static void assert_all_threads_claimed() NOT_DEBUG_RETURN;
1739 
1740   // Apply "f->do_oop" to all root oops in all threads.
1741   // This version may only be called by sequential code.
1742   static void oops_do(OopClosure* f, CodeBlobClosure* cf);
1743   // This version may be called by sequential or parallel code.
1744   static void possibly_parallel_oops_do(bool is_par, OopClosure* f, CodeBlobClosure* cf);
1745 
1746   // RedefineClasses support
1747   static void metadata_do(MetadataClosure* f);
1748   static void metadata_handles_do(void f(Metadata*));
1749 
1750 #ifdef ASSERT
1751   static bool is_vm_complete() { return _vm_complete; }
1752 #endif // ASSERT
1753 
1754   // Verification
1755   static void verify();
1756   static void print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks, bool print_extended_info);
1757   static void print(bool print_stacks, bool internal_format) {
1758     // this function is only used by debug.cpp
1759     print_on(tty, print_stacks, internal_format, false /* no concurrent lock printed */, false /* simple format */);
1760   }
1761   static void print_on_error(outputStream* st, Thread* current, char* buf, int buflen);
1762   static void print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
1763                              int buflen, bool* found_current);
1764   static void print_threads_compiling(outputStream* st, char* buf, int buflen, bool short_form = false);
1765 
1766   // Get Java threads that are waiting to enter a monitor.
1767   static GrowableArray<JavaThread*>* get_pending_threads(ThreadsList * t_list,
1768                                                          int count, address monitor);
1769 
1770   // Get owning Java thread from the monitor's owner field.
1771   static JavaThread *owning_thread_from_monitor_owner(ThreadsList * t_list,
1772                                                       address owner);
1773 
1774   // Number of threads on the active threads list
1775   static int number_of_threads()                 { return _number_of_threads; }
1776   // Number of non-daemon threads on the active threads list
1777   static int number_of_non_daemon_threads()      { return _number_of_non_daemon_threads; }
1778 
1779   // Deoptimizes all frames tied to marked nmethods
1780   static void deoptimized_wrt_marked_nmethods();
1781 
1782   struct Test;                  // For private gtest access.
1783 };
1784 
1785 class UnlockFlagSaver {
1786   private:
1787     JavaThread* _thread;
1788     bool _do_not_unlock;
1789   public:
1790     UnlockFlagSaver(JavaThread* t) {
1791       _thread = t;
1792       _do_not_unlock = t->do_not_unlock_if_synchronized();
1793       t->set_do_not_unlock_if_synchronized(false);
1794     }
1795     ~UnlockFlagSaver() {
1796       _thread->set_do_not_unlock_if_synchronized(_do_not_unlock);
1797     }
1798 };
1799 
1800 #endif // SHARE_RUNTIME_THREAD_HPP