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