1 /*
   2  * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_RUNTIME_THREAD_HPP
  26 #define SHARE_VM_RUNTIME_THREAD_HPP
  27 
  28 #include "jni.h"
  29 #include "gc/shared/gcThreadLocalData.hpp"
  30 #include "gc/shared/threadLocalAllocBuffer.hpp"
  31 #include "memory/allocation.hpp"
  32 #include "oops/oop.hpp"
  33 #include "prims/jvmtiExport.hpp"
  34 #include "runtime/frame.hpp"
  35 #include "runtime/globals.hpp"
  36 #include "runtime/handshake.hpp"
  37 #include "runtime/javaFrameAnchor.hpp"
  38 #include "runtime/jniHandles.hpp"
  39 #include "runtime/mutexLocker.hpp"
  40 #include "runtime/os.hpp"
  41 #include "runtime/osThread.hpp"
  42 #include "runtime/park.hpp"
  43 #include "runtime/safepoint.hpp"
  44 #include "runtime/stubRoutines.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/macros.hpp"
  52 #ifdef ZERO
  53 # include "stack_zero.hpp"
  54 #endif
  55 #if INCLUDE_JFR
  56 #include "jfr/support/jfrThreadExtension.hpp"
  57 #endif
  58 
  59 class BehaviourProvider;
  60 
  61 class SafeThreadsListPtr;
  62 class ThreadSafepointState;
  63 class ThreadsList;
  64 class ThreadsSMRSupport;
  65 
  66 class JvmtiThreadState;
  67 class JvmtiGetLoadedClassesClosure;
  68 class ThreadStatistics;
  69 class ConcurrentLocksDump;
  70 class ParkEvent;
  71 class Parker;
  72 
  73 class ciEnv;
  74 class CompileThread;
  75 class CompileLog;
  76 class CompileTask;
  77 class CompileQueue;
  78 class CompilerCounters;
  79 class vframeArray;
  80 
  81 class DeoptResourceMark;
  82 class jvmtiDeferredLocalVariableSet;
  83 
  84 class GCTaskQueue;
  85 class ThreadClosure;
  86 class IdealGraphPrinter;
  87 
  88 class Metadata;
  89 template <class T, MEMFLAGS F> class ChunkedList;
  90 typedef ChunkedList<Metadata*, mtInternal> MetadataOnStackBuffer;
  91 
  92 DEBUG_ONLY(class ResourceMark;)
  93 
  94 class WorkerThread;
  95 
  96 // Class hierarchy
  97 // - Thread
  98 //   - NamedThread
  99 //     - VMThread
 100 //     - ConcurrentGCThread
 101 //     - WorkerThread
 102 //       - GangWorker
 103 //       - GCTaskThread
 104 //   - JavaThread
 105 //     - various subclasses eg CompilerThread, ServiceThread
 106 //   - WatcherThread
 107 
 108 class Thread: public ThreadShadow {
 109   friend class VMStructs;
 110   friend class JVMCIVMStructs;
 111  private:
 112 
 113 #ifndef USE_LIBRARY_BASED_TLS_ONLY
 114   // Current thread is maintained as a thread-local variable
 115   static THREAD_LOCAL_DECL Thread* _thr_current;
 116 #endif
 117 
 118  private:
 119   // Thread local data area available to the GC. The internal
 120   // structure and contents of this data area is GC-specific.
 121   // Only GC and GC barrier code should access this data area.
 122   GCThreadLocalData _gc_data;
 123 
 124  public:
 125   static ByteSize gc_data_offset() {
 126     return byte_offset_of(Thread, _gc_data);
 127   }
 128 
 129   template <typename T> T* gc_data() {
 130     STATIC_ASSERT(sizeof(T) <= sizeof(_gc_data));
 131     return reinterpret_cast<T*>(&_gc_data);
 132   }
 133 
 134   // Exception handling
 135   // (Note: _pending_exception and friends are in ThreadShadow)
 136   //oop       _pending_exception;                // pending exception for current thread
 137   // const char* _exception_file;                   // file information for exception (debugging only)
 138   // int         _exception_line;                   // line information for exception (debugging only)
 139  protected:
 140   // Support for forcing alignment of thread objects for biased locking
 141   void*       _real_malloc_address;
 142 
 143   // JavaThread lifecycle support:
 144   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
 145   friend class ScanHazardPtrGatherProtectedThreadsClosure;  // for cmpxchg_threads_hazard_ptr(), get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
 146   friend class ScanHazardPtrGatherThreadsListClosure;  // for get_threads_hazard_ptr(), untag_hazard_ptr() access
 147   friend class ScanHazardPtrPrintMatchingThreadsClosure;  // for get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
 148   friend class ThreadsSMRSupport;  // for _nested_threads_hazard_ptr_cnt, _threads_hazard_ptr, _threads_list_ptr access
 149 
 150   ThreadsList* volatile _threads_hazard_ptr;
 151   SafeThreadsListPtr*   _threads_list_ptr;
 152   ThreadsList*          cmpxchg_threads_hazard_ptr(ThreadsList* exchange_value, ThreadsList* compare_value);
 153   ThreadsList*          get_threads_hazard_ptr();
 154   void                  set_threads_hazard_ptr(ThreadsList* new_list);
 155   static bool           is_hazard_ptr_tagged(ThreadsList* list) {
 156     return (intptr_t(list) & intptr_t(1)) == intptr_t(1);
 157   }
 158   static ThreadsList*   tag_hazard_ptr(ThreadsList* list) {
 159     return (ThreadsList*)(intptr_t(list) | intptr_t(1));
 160   }
 161   static ThreadsList*   untag_hazard_ptr(ThreadsList* list) {
 162     return (ThreadsList*)(intptr_t(list) & ~intptr_t(1));
 163   }
 164   // This field is enabled via -XX:+EnableThreadSMRStatistics:
 165   uint _nested_threads_hazard_ptr_cnt;
 166   void dec_nested_threads_hazard_ptr_cnt() {
 167     assert(_nested_threads_hazard_ptr_cnt != 0, "mismatched {dec,inc}_nested_threads_hazard_ptr_cnt()");
 168     _nested_threads_hazard_ptr_cnt--;
 169   }
 170   void inc_nested_threads_hazard_ptr_cnt() {
 171     _nested_threads_hazard_ptr_cnt++;
 172   }
 173   uint nested_threads_hazard_ptr_cnt() {
 174     return _nested_threads_hazard_ptr_cnt;
 175   }
 176 
 177   BehaviourProvider* _behaviour_provider;
 178 
 179  public:
 180   BehaviourProvider* behaviour_provider() const { return _behaviour_provider; }
 181   void set_behaviour_provider(BehaviourProvider* behaviour_provider) { _behaviour_provider = behaviour_provider; }
 182 
 183   void* operator new(size_t size) throw() { return allocate(size, true); }
 184   void* operator new(size_t size, const std::nothrow_t& nothrow_constant) throw() {
 185     return allocate(size, false); }
 186   void  operator delete(void* p);
 187 
 188  protected:
 189   static void* allocate(size_t size, bool throw_excpt, MEMFLAGS flags = mtThread);
 190  private:
 191 
 192   // ***************************************************************
 193   // Suspend and resume support
 194   // ***************************************************************
 195   //
 196   // VM suspend/resume no longer exists - it was once used for various
 197   // things including safepoints but was deprecated and finally removed
 198   // in Java 7. Because VM suspension was considered "internal" Java-level
 199   // suspension was considered "external", and this legacy naming scheme
 200   // remains.
 201   //
 202   // External suspend/resume requests come from JVM_SuspendThread,
 203   // JVM_ResumeThread, JVMTI SuspendThread, and finally JVMTI
 204   // ResumeThread. External
 205   // suspend requests cause _external_suspend to be set and external
 206   // resume requests cause _external_suspend to be cleared.
 207   // External suspend requests do not nest on top of other external
 208   // suspend requests. The higher level APIs reject suspend requests
 209   // for already suspended threads.
 210   //
 211   // The external_suspend
 212   // flag is checked by has_special_runtime_exit_condition() and java thread
 213   // will self-suspend when handle_special_runtime_exit_condition() is
 214   // called. Most uses of the _thread_blocked state in JavaThreads are
 215   // considered the same as being externally suspended; if the blocking
 216   // condition lifts, the JavaThread will self-suspend. Other places
 217   // where VM checks for external_suspend include:
 218   //   + mutex granting (do not enter monitors when thread is suspended)
 219   //   + state transitions from _thread_in_native
 220   //
 221   // In general, java_suspend() does not wait for an external suspend
 222   // request to complete. When it returns, the only guarantee is that
 223   // the _external_suspend field is true.
 224   //
 225   // wait_for_ext_suspend_completion() is used to wait for an external
 226   // suspend request to complete. External suspend requests are usually
 227   // followed by some other interface call that requires the thread to
 228   // be quiescent, e.g., GetCallTrace(). By moving the "wait time" into
 229   // the interface that requires quiescence, we give the JavaThread a
 230   // chance to self-suspend before we need it to be quiescent. This
 231   // improves overall suspend/query performance.
 232   //
 233   // _suspend_flags controls the behavior of java_ suspend/resume.
 234   // It must be set under the protection of SR_lock. Read from the flag is
 235   // OK without SR_lock as long as the value is only used as a hint.
 236   // (e.g., check _external_suspend first without lock and then recheck
 237   // inside SR_lock and finish the suspension)
 238   //
 239   // _suspend_flags is also overloaded for other "special conditions" so
 240   // that a single check indicates whether any special action is needed
 241   // eg. for async exceptions.
 242   // -------------------------------------------------------------------
 243   // Notes:
 244   // 1. The suspend/resume logic no longer uses ThreadState in OSThread
 245   // but we still update its value to keep other part of the system (mainly
 246   // JVMTI) happy. ThreadState is legacy code (see notes in
 247   // osThread.hpp).
 248   //
 249   // 2. It would be more natural if set_external_suspend() is private and
 250   // part of java_suspend(), but that probably would affect the suspend/query
 251   // performance. Need more investigation on this.
 252 
 253   // suspend/resume lock: used for self-suspend
 254   Monitor* _SR_lock;
 255 
 256  protected:
 257   enum SuspendFlags {
 258     // NOTE: avoid using the sign-bit as cc generates different test code
 259     //       when the sign-bit is used, and sometimes incorrectly - see CR 6398077
 260 
 261     _external_suspend       = 0x20000000U, // thread is asked to self suspend
 262     _ext_suspended          = 0x40000000U, // thread has self-suspended
 263     _deopt_suspend          = 0x10000000U, // thread needs to self suspend for deopt
 264 
 265     _has_async_exception    = 0x00000001U, // there is a pending async exception
 266     _critical_native_unlock = 0x00000002U, // Must call back to unlock JNI critical lock
 267 
 268     _trace_flag             = 0x00000004U  // call tracing backend
 269   };
 270 
 271   // various suspension related flags - atomically updated
 272   // overloaded for async exception checking in check_special_condition_for_native_trans.
 273   volatile uint32_t _suspend_flags;
 274 
 275  private:
 276   int _num_nested_signal;
 277 
 278   DEBUG_ONLY(bool _suspendible_thread;)
 279 
 280  public:
 281   void enter_signal_handler() { _num_nested_signal++; }
 282   void leave_signal_handler() { _num_nested_signal--; }
 283   bool is_inside_signal_handler() const { return _num_nested_signal > 0; }
 284 
 285 #ifdef ASSERT
 286   void set_suspendible_thread() {
 287     _suspendible_thread = true;
 288   }
 289 
 290   void clear_suspendible_thread() {
 291     _suspendible_thread = false;
 292   }
 293 
 294   bool is_suspendible_thread() { return _suspendible_thread; }
 295 #endif
 296 
 297  private:
 298   // Active_handles points to a block of handles
 299   JNIHandleBlock* _active_handles;
 300 
 301   // One-element thread local free list
 302   JNIHandleBlock* _free_handle_block;
 303 
 304   // Point to the last handle mark
 305   HandleMark* _last_handle_mark;
 306 
 307   // The parity of the last strong_roots iteration in which this thread was
 308   // claimed as a task.
 309   int _oops_do_parity;
 310 
 311   // Support for GlobalCounter
 312  private:
 313   volatile uintx _rcu_counter;
 314  public:
 315   volatile uintx* get_rcu_counter() {
 316     return &_rcu_counter;
 317   }
 318 
 319  public:
 320   void set_last_handle_mark(HandleMark* mark)   { _last_handle_mark = mark; }
 321   HandleMark* last_handle_mark() const          { return _last_handle_mark; }
 322  private:
 323 
 324   // debug support for checking if code does allow safepoints or not
 325   // GC points in the VM can happen because of allocation, invoking a VM operation, or blocking on
 326   // mutex, or blocking on an object synchronizer (Java locking).
 327   // If !allow_safepoint(), then an assertion failure will happen in any of the above cases
 328   // If !allow_allocation(), then an assertion failure will happen during allocation
 329   // (Hence, !allow_safepoint() => !allow_allocation()).
 330   //
 331   // The two classes NoSafepointVerifier and No_Allocation_Verifier are used to set these counters.
 332   //
 333   NOT_PRODUCT(int _allow_safepoint_count;)      // If 0, thread allow a safepoint to happen
 334   debug_only(int _allow_allocation_count;)     // If 0, the thread is allowed to allocate oops.
 335 
 336   // Used by SkipGCALot class.
 337   NOT_PRODUCT(bool _skip_gcalot;)               // Should we elide gc-a-lot?
 338 
 339   friend class NoAllocVerifier;
 340   friend class NoSafepointVerifier;
 341   friend class PauseNoSafepointVerifier;
 342   friend class GCLocker;
 343 
 344   volatile void* _polling_page;                 // Thread local polling page
 345 
 346   ThreadLocalAllocBuffer _tlab;                 // Thread-local eden
 347   jlong _allocated_bytes;                       // Cumulative number of bytes allocated on
 348                                                 // the Java heap
 349   ThreadHeapSampler _heap_sampler;              // For use when sampling the memory.
 350 
 351   ThreadStatisticalInfo _statistical_info;      // Statistics about the thread
 352 
 353   JFR_ONLY(DEFINE_THREAD_LOCAL_FIELD_JFR;)      // Thread-local data for jfr
 354 
 355   int   _vm_operation_started_count;            // VM_Operation support
 356   int   _vm_operation_completed_count;          // VM_Operation support
 357 
 358   ObjectMonitor* _current_pending_monitor;      // ObjectMonitor this thread
 359                                                 // is waiting to lock
 360   bool _current_pending_monitor_is_from_java;   // locking is from Java code
 361 
 362   // ObjectMonitor on which this thread called Object.wait()
 363   ObjectMonitor* _current_waiting_monitor;
 364 
 365   // Private thread-local objectmonitor list - a simple cache organized as a SLL.
 366  public:
 367   ObjectMonitor* omFreeList;
 368   int omFreeCount;                              // length of omFreeList
 369   int omFreeProvision;                          // reload chunk size
 370   ObjectMonitor* omInUseList;                   // SLL to track monitors in circulation
 371   int omInUseCount;                             // length of omInUseList
 372 
 373 #ifdef ASSERT
 374  private:
 375   bool _visited_for_critical_count;
 376 
 377  public:
 378   void set_visited_for_critical_count(bool z) { _visited_for_critical_count = z; }
 379   bool was_visited_for_critical_count() const   { return _visited_for_critical_count; }
 380 #endif
 381 
 382  public:
 383   enum {
 384     is_definitely_current_thread = true
 385   };
 386 
 387   // Constructor
 388   Thread();
 389   virtual ~Thread();
 390 
 391   // Manage Thread::current()
 392   void initialize_thread_current();
 393   void clear_thread_current(); // TLS cleanup needed before threads terminate
 394 
 395  public:
 396   // thread entry point
 397   virtual void run();
 398 
 399   // Testers
 400   virtual bool is_VM_thread()       const            { return false; }
 401   virtual bool is_Java_thread()     const            { return false; }
 402   virtual bool is_Compiler_thread() const            { return false; }
 403   virtual bool is_Code_cache_sweeper_thread() const  { return false; }
 404   virtual bool is_hidden_from_external_view() const  { return false; }
 405   virtual bool is_jvmti_agent_thread() const         { return false; }
 406   // True iff the thread can perform GC operations at a safepoint.
 407   // Generally will be true only of VM thread and parallel GC WorkGang
 408   // threads.
 409   virtual bool is_GC_task_thread() const             { return false; }
 410   virtual bool is_Watcher_thread() const             { return false; }
 411   virtual bool is_ConcurrentGC_thread() const        { return false; }
 412   virtual bool is_Named_thread() const               { return false; }
 413   virtual bool is_Worker_thread() const              { return false; }
 414 
 415   // Can this thread make Java upcalls
 416   virtual bool can_call_java() const                 { return false; }
 417 
 418   // Casts
 419   virtual WorkerThread* as_Worker_thread() const     { return NULL; }
 420 
 421   virtual char* name() const { return (char*)"Unknown thread"; }
 422 
 423   // Returns the current thread (ASSERTS if NULL)
 424   static inline Thread* current();
 425   // Returns the current thread, or NULL if not attached
 426   static inline Thread* current_or_null();
 427   // Returns the current thread, or NULL if not attached, and is
 428   // safe for use from signal-handlers
 429   static inline Thread* current_or_null_safe();
 430 
 431   // Common thread operations
 432 #ifdef ASSERT
 433   static void check_for_dangling_thread_pointer(Thread *thread);
 434 #endif
 435   static void set_priority(Thread* thread, ThreadPriority priority);
 436   static ThreadPriority get_priority(const Thread* const thread);
 437   static void start(Thread* thread);
 438   static void interrupt(Thread* thr);
 439   static bool is_interrupted(Thread* thr, bool clear_interrupted);
 440 
 441   void set_native_thread_name(const char *name) {
 442     assert(Thread::current() == this, "set_native_thread_name can only be called on the current thread");
 443     os::set_native_thread_name(name);
 444   }
 445 
 446   ObjectMonitor** omInUseList_addr()             { return (ObjectMonitor **)&omInUseList; }
 447   Monitor* SR_lock() const                       { return _SR_lock; }
 448 
 449   bool has_async_exception() const { return (_suspend_flags & _has_async_exception) != 0; }
 450 
 451   inline void set_suspend_flag(SuspendFlags f);
 452   inline void clear_suspend_flag(SuspendFlags f);
 453 
 454   inline void set_has_async_exception();
 455   inline void clear_has_async_exception();
 456 
 457   bool do_critical_native_unlock() const { return (_suspend_flags & _critical_native_unlock) != 0; }
 458 
 459   inline void set_critical_native_unlock();
 460   inline void clear_critical_native_unlock();
 461 
 462   inline void set_trace_flag();
 463   inline void clear_trace_flag();
 464 
 465   // Support for Unhandled Oop detection
 466   // Add the field for both, fastdebug and debug, builds to keep
 467   // Thread's fields layout the same.
 468   // Note: CHECK_UNHANDLED_OOPS is defined only for fastdebug build.
 469 #ifdef CHECK_UNHANDLED_OOPS
 470  private:
 471   UnhandledOops* _unhandled_oops;
 472 #elif defined(ASSERT)
 473  private:
 474   void* _unhandled_oops;
 475 #endif
 476 #ifdef CHECK_UNHANDLED_OOPS
 477  public:
 478   UnhandledOops* unhandled_oops() { return _unhandled_oops; }
 479   // Mark oop safe for gc.  It may be stack allocated but won't move.
 480   void allow_unhandled_oop(oop *op) {
 481     if (CheckUnhandledOops) unhandled_oops()->allow_unhandled_oop(op);
 482   }
 483   // Clear oops at safepoint so crashes point to unhandled oop violator
 484   void clear_unhandled_oops() {
 485     if (CheckUnhandledOops) unhandled_oops()->clear_unhandled_oops();
 486   }
 487 #endif // CHECK_UNHANDLED_OOPS
 488 
 489  public:
 490 #ifndef PRODUCT
 491   bool skip_gcalot()           { return _skip_gcalot; }
 492   void set_skip_gcalot(bool v) { _skip_gcalot = v;    }
 493 #endif
 494 
 495   // Installs a pending exception to be inserted later
 496   static void send_async_exception(oop thread_oop, oop java_throwable);
 497 
 498   // Resource area
 499   ResourceArea* resource_area() const            { return _resource_area; }
 500   void set_resource_area(ResourceArea* area)     { _resource_area = area; }
 501 
 502   OSThread* osthread() const                     { return _osthread;   }
 503   void set_osthread(OSThread* thread)            { _osthread = thread; }
 504 
 505   // JNI handle support
 506   JNIHandleBlock* active_handles() const         { return _active_handles; }
 507   void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
 508   JNIHandleBlock* free_handle_block() const      { return _free_handle_block; }
 509   void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
 510 
 511   // Internal handle support
 512   HandleArea* handle_area() const                { return _handle_area; }
 513   void set_handle_area(HandleArea* area)         { _handle_area = area; }
 514 
 515   GrowableArray<Metadata*>* metadata_handles() const          { return _metadata_handles; }
 516   void set_metadata_handles(GrowableArray<Metadata*>* handles){ _metadata_handles = handles; }
 517 
 518   // Thread-Local Allocation Buffer (TLAB) support
 519   ThreadLocalAllocBuffer& tlab()                 { return _tlab; }
 520   void initialize_tlab() {
 521     if (UseTLAB) {
 522       tlab().initialize();
 523     }
 524   }
 525 
 526   jlong allocated_bytes()               { return _allocated_bytes; }
 527   void set_allocated_bytes(jlong value) { _allocated_bytes = value; }
 528   void incr_allocated_bytes(jlong size) { _allocated_bytes += size; }
 529   inline jlong cooked_allocated_bytes();
 530 
 531   ThreadHeapSampler& heap_sampler()     { return _heap_sampler; }
 532 
 533   ThreadStatisticalInfo& statistical_info() { return _statistical_info; }
 534 
 535   JFR_ONLY(DEFINE_THREAD_LOCAL_ACCESSOR_JFR;)
 536 
 537   bool is_trace_suspend()               { return (_suspend_flags & _trace_flag) != 0; }
 538 
 539   // VM operation support
 540   int vm_operation_ticket()                      { return ++_vm_operation_started_count; }
 541   int vm_operation_completed_count()             { return _vm_operation_completed_count; }
 542   void increment_vm_operation_completed_count()  { _vm_operation_completed_count++; }
 543 
 544   // For tracking the heavyweight monitor the thread is pending on.
 545   ObjectMonitor* current_pending_monitor() {
 546     return _current_pending_monitor;
 547   }
 548   void set_current_pending_monitor(ObjectMonitor* monitor) {
 549     _current_pending_monitor = monitor;
 550   }
 551   void set_current_pending_monitor_is_from_java(bool from_java) {
 552     _current_pending_monitor_is_from_java = from_java;
 553   }
 554   bool current_pending_monitor_is_from_java() {
 555     return _current_pending_monitor_is_from_java;
 556   }
 557 
 558   // For tracking the ObjectMonitor on which this thread called Object.wait()
 559   ObjectMonitor* current_waiting_monitor() {
 560     return _current_waiting_monitor;
 561   }
 562   void set_current_waiting_monitor(ObjectMonitor* monitor) {
 563     _current_waiting_monitor = monitor;
 564   }
 565 
 566   // GC support
 567   // Apply "f->do_oop" to all root oops in "this".
 568   //   Used by JavaThread::oops_do.
 569   // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames
 570   virtual void oops_do(OopClosure* f, CodeBlobClosure* cf);
 571 
 572   // Handles the parallel case for the method below.
 573  private:
 574   bool claim_oops_do_par_case(int collection_parity);
 575  public:
 576   // Requires that "collection_parity" is that of the current roots
 577   // iteration.  If "is_par" is false, sets the parity of "this" to
 578   // "collection_parity", and returns "true".  If "is_par" is true,
 579   // uses an atomic instruction to set the current threads parity to
 580   // "collection_parity", if it is not already.  Returns "true" iff the
 581   // calling thread does the update, this indicates that the calling thread
 582   // has claimed the thread's stack as a root groop in the current
 583   // collection.
 584   bool claim_oops_do(bool is_par, int collection_parity) {
 585     if (!is_par) {
 586       _oops_do_parity = collection_parity;
 587       return true;
 588     } else {
 589       return claim_oops_do_par_case(collection_parity);
 590     }
 591   }
 592 
 593   // jvmtiRedefineClasses support
 594   void metadata_handles_do(void f(Metadata*));
 595 
 596   // Used by fast lock support
 597   virtual bool is_lock_owned(address adr) const;
 598 
 599   // Check if address is in the stack of the thread (not just for locks).
 600   // Warning: the method can only be used on the running thread
 601   bool is_in_stack(address adr) const;
 602   // Check if address is in the usable part of the stack (excludes protected
 603   // guard pages)
 604   bool is_in_usable_stack(address adr) const;
 605 
 606   // Sets this thread as starting thread. Returns failure if thread
 607   // creation fails due to lack of memory, too many threads etc.
 608   bool set_as_starting_thread();
 609 
 610 protected:
 611   // OS data associated with the thread
 612   OSThread* _osthread;  // Platform-specific thread information
 613 
 614   // Thread local resource area for temporary allocation within the VM
 615   ResourceArea* _resource_area;
 616 
 617   DEBUG_ONLY(ResourceMark* _current_resource_mark;)
 618 
 619   // Thread local handle area for allocation of handles within the VM
 620   HandleArea* _handle_area;
 621   GrowableArray<Metadata*>* _metadata_handles;
 622 
 623   // Support for stack overflow handling, get_thread, etc.
 624   address          _stack_base;
 625   size_t           _stack_size;
 626   uintptr_t        _self_raw_id;      // used by get_thread (mutable)
 627   int              _lgrp_id;
 628 
 629   volatile void** polling_page_addr() { return &_polling_page; }
 630 
 631  public:
 632   // Stack overflow support
 633   address stack_base() const           { assert(_stack_base != NULL,"Sanity check"); return _stack_base; }
 634   void    set_stack_base(address base) { _stack_base = base; }
 635   size_t  stack_size() const           { return _stack_size; }
 636   void    set_stack_size(size_t size)  { _stack_size = size; }
 637   address stack_end()  const           { return stack_base() - stack_size(); }
 638   void    record_stack_base_and_size();
 639 
 640   bool    on_local_stack(address adr) const {
 641     // QQQ this has knowledge of direction, ought to be a stack method
 642     return (_stack_base >= adr && adr >= stack_end());
 643   }
 644 
 645   uintptr_t self_raw_id()                    { return _self_raw_id; }
 646   void      set_self_raw_id(uintptr_t value) { _self_raw_id = value; }
 647 
 648   int     lgrp_id() const        { return _lgrp_id; }
 649   void    set_lgrp_id(int value) { _lgrp_id = value; }
 650 
 651   // Printing
 652   void print_on(outputStream* st, bool print_extended_info) const;
 653   virtual void print_on(outputStream* st) const { print_on(st, false); }
 654   void print() const { print_on(tty); }
 655   virtual void print_on_error(outputStream* st, char* buf, int buflen) const;
 656   void print_value_on(outputStream* st) const;
 657 
 658   // Debug-only code
 659 #ifdef ASSERT
 660  private:
 661   // Deadlock detection support for Mutex locks. List of locks own by thread.
 662   Monitor* _owned_locks;
 663   // Mutex::set_owner_implementation is the only place where _owned_locks is modified,
 664   // thus the friendship
 665   friend class Mutex;
 666   friend class Monitor;
 667 
 668  public:
 669   void print_owned_locks_on(outputStream* st) const;
 670   void print_owned_locks() const                 { print_owned_locks_on(tty);    }
 671   Monitor* owned_locks() const                   { return _owned_locks;          }
 672   bool owns_locks() const                        { return owned_locks() != NULL; }
 673   bool owns_locks_but_compiled_lock() const;
 674   int oops_do_parity() const                     { return _oops_do_parity; }
 675 
 676   // Deadlock detection
 677   bool allow_allocation()                        { return _allow_allocation_count == 0; }
 678   ResourceMark* current_resource_mark()          { return _current_resource_mark; }
 679   void set_current_resource_mark(ResourceMark* rm) { _current_resource_mark = rm; }
 680 #endif
 681 
 682   void check_for_valid_safepoint_state(bool potential_vm_operation) PRODUCT_RETURN;
 683 
 684  private:
 685   volatile int _jvmti_env_iteration_count;
 686 
 687  public:
 688   void entering_jvmti_env_iteration()            { ++_jvmti_env_iteration_count; }
 689   void leaving_jvmti_env_iteration()             { --_jvmti_env_iteration_count; }
 690   bool is_inside_jvmti_env_iteration()           { return _jvmti_env_iteration_count > 0; }
 691 
 692   // Code generation
 693   static ByteSize exception_file_offset()        { return byte_offset_of(Thread, _exception_file); }
 694   static ByteSize exception_line_offset()        { return byte_offset_of(Thread, _exception_line); }
 695   static ByteSize active_handles_offset()        { return byte_offset_of(Thread, _active_handles); }
 696 
 697   static ByteSize stack_base_offset()            { return byte_offset_of(Thread, _stack_base); }
 698   static ByteSize stack_size_offset()            { return byte_offset_of(Thread, _stack_size); }
 699 
 700   static ByteSize polling_page_offset()          { return byte_offset_of(Thread, _polling_page); }
 701 
 702 #define TLAB_FIELD_OFFSET(name) \
 703   static ByteSize tlab_##name##_offset()         { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::name##_offset(); }
 704 
 705   TLAB_FIELD_OFFSET(start)
 706   TLAB_FIELD_OFFSET(end)
 707   TLAB_FIELD_OFFSET(top)
 708   TLAB_FIELD_OFFSET(pf_top)
 709   TLAB_FIELD_OFFSET(size)                   // desired_size
 710   TLAB_FIELD_OFFSET(refill_waste_limit)
 711   TLAB_FIELD_OFFSET(number_of_refills)
 712   TLAB_FIELD_OFFSET(fast_refill_waste)
 713   TLAB_FIELD_OFFSET(slow_allocations)
 714 
 715 #undef TLAB_FIELD_OFFSET
 716 
 717   static ByteSize allocated_bytes_offset()       { return byte_offset_of(Thread, _allocated_bytes); }
 718 
 719   JFR_ONLY(DEFINE_THREAD_LOCAL_OFFSET_JFR;)
 720 
 721  public:
 722   volatile intptr_t _Stalled;
 723   volatile int _TypeTag;
 724   ParkEvent * _ParkEvent;                     // for synchronized()
 725   ParkEvent * _SleepEvent;                    // for Thread.sleep
 726   ParkEvent * _MutexEvent;                    // for native internal Mutex/Monitor
 727   ParkEvent * _MuxEvent;                      // for low-level muxAcquire-muxRelease
 728   int NativeSyncRecursion;                    // diagnostic
 729 
 730   volatile int _OnTrap;                       // Resume-at IP delta
 731   jint _hashStateW;                           // Marsaglia Shift-XOR thread-local RNG
 732   jint _hashStateX;                           // thread-specific hashCode generator state
 733   jint _hashStateY;
 734   jint _hashStateZ;
 735 
 736   volatile jint rng[4];                      // RNG for spin loop
 737 
 738   // Low-level leaf-lock primitives used to implement synchronization
 739   // and native monitor-mutex infrastructure.
 740   // Not for general synchronization use.
 741   static void SpinAcquire(volatile int * Lock, const char * Name);
 742   static void SpinRelease(volatile int * Lock);
 743   static void muxAcquire(volatile intptr_t * Lock, const char * Name);
 744   static void muxAcquireW(volatile intptr_t * Lock, ParkEvent * ev);
 745   static void muxRelease(volatile intptr_t * Lock);
 746 };
 747 
 748 // Inline implementation of Thread::current()
 749 inline Thread* Thread::current() {
 750   Thread* current = current_or_null();
 751   assert(current != NULL, "Thread::current() called on detached thread");
 752   return current;
 753 }
 754 
 755 inline Thread* Thread::current_or_null() {
 756 #ifndef USE_LIBRARY_BASED_TLS_ONLY
 757   return _thr_current;
 758 #else
 759   if (ThreadLocalStorage::is_initialized()) {
 760     return ThreadLocalStorage::thread();
 761   }
 762   return NULL;
 763 #endif
 764 }
 765 
 766 inline Thread* Thread::current_or_null_safe() {
 767   if (ThreadLocalStorage::is_initialized()) {
 768     return ThreadLocalStorage::thread();
 769   }
 770   return NULL;
 771 }
 772 
 773 // Name support for threads.  non-JavaThread subclasses with multiple
 774 // uniquely named instances should derive from this.
 775 class NamedThread: public Thread {
 776   friend class VMStructs;
 777   enum {
 778     max_name_len = 64
 779   };
 780  private:
 781   char* _name;
 782   // log JavaThread being processed by oops_do
 783   JavaThread* _processed_thread;
 784   uint _gc_id; // The current GC id when a thread takes part in GC
 785 
 786  public:
 787   NamedThread();
 788   ~NamedThread();
 789   // May only be called once per thread.
 790   void set_name(const char* format, ...)  ATTRIBUTE_PRINTF(2, 3);
 791   void initialize_named_thread();
 792   virtual bool is_Named_thread() const { return true; }
 793   virtual char* name() const { return _name == NULL ? (char*)"Unknown Thread" : _name; }
 794   JavaThread *processed_thread() { return _processed_thread; }
 795   void set_processed_thread(JavaThread *thread) { _processed_thread = thread; }
 796   virtual void print_on(outputStream* st) const;
 797 
 798   void set_gc_id(uint gc_id) { _gc_id = gc_id; }
 799   uint gc_id() { return _gc_id; }
 800 };
 801 
 802 // Worker threads are named and have an id of an assigned work.
 803 class WorkerThread: public NamedThread {
 804  private:
 805   uint _id;
 806  public:
 807   WorkerThread() : _id(0)               { }
 808   virtual bool is_Worker_thread() const { return true; }
 809 
 810   virtual WorkerThread* as_Worker_thread() const {
 811     assert(is_Worker_thread(), "Dubious cast to WorkerThread*?");
 812     return (WorkerThread*) this;
 813   }
 814 
 815   void set_id(uint work_id)             { _id = work_id; }
 816   uint id() const                       { return _id; }
 817 };
 818 
 819 // A single WatcherThread is used for simulating timer interrupts.
 820 class WatcherThread: public Thread {
 821   friend class VMStructs;
 822  public:
 823   virtual void run();
 824 
 825  private:
 826   static WatcherThread* _watcher_thread;
 827 
 828   static bool _startable;
 829   // volatile due to at least one lock-free read
 830   volatile static bool _should_terminate;
 831  public:
 832   enum SomeConstants {
 833     delay_interval = 10                          // interrupt delay in milliseconds
 834   };
 835 
 836   // Constructor
 837   WatcherThread();
 838 
 839   // No destruction allowed
 840   ~WatcherThread() {
 841     guarantee(false, "WatcherThread deletion must fix the race with VM termination");
 842   }
 843 
 844   // Tester
 845   bool is_Watcher_thread() const                 { return true; }
 846 
 847   // Printing
 848   char* name() const { return (char*)"VM Periodic Task Thread"; }
 849   void print_on(outputStream* st) const;
 850   void unpark();
 851 
 852   // Returns the single instance of WatcherThread
 853   static WatcherThread* watcher_thread()         { return _watcher_thread; }
 854 
 855   // Create and start the single instance of WatcherThread, or stop it on shutdown
 856   static void start();
 857   static void stop();
 858   // Only allow start once the VM is sufficiently initialized
 859   // Otherwise the first task to enroll will trigger the start
 860   static void make_startable();
 861  private:
 862   int sleep() const;
 863 };
 864 
 865 
 866 class CompilerThread;
 867 
 868 typedef void (*ThreadFunction)(JavaThread*, TRAPS);
 869 
 870 class JavaThread: public Thread {
 871   friend class VMStructs;
 872   friend class JVMCIVMStructs;
 873   friend class WhiteBox;
 874  private:
 875   JavaThread*    _next;                          // The next thread in the Threads list
 876   bool           _on_thread_list;                // Is set when this JavaThread is added to the Threads list
 877   oop            _threadObj;                     // The Java level thread object
 878 
 879 #ifdef ASSERT
 880  private:
 881   int _java_call_counter;
 882 
 883  public:
 884   int  java_call_counter()                       { return _java_call_counter; }
 885   void inc_java_call_counter()                   { _java_call_counter++; }
 886   void dec_java_call_counter() {
 887     assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
 888     _java_call_counter--;
 889   }
 890  private:  // restore original namespace restriction
 891 #endif  // ifdef ASSERT
 892 
 893 #ifndef PRODUCT
 894  public:
 895   enum {
 896     jump_ring_buffer_size = 16
 897   };
 898  private:  // restore original namespace restriction
 899 #endif
 900 
 901   JavaFrameAnchor _anchor;                       // Encapsulation of current java frame and it state
 902 
 903   ThreadFunction _entry_point;
 904 
 905   JNIEnv        _jni_environment;
 906 
 907   // Deopt support
 908   DeoptResourceMark*  _deopt_mark;               // Holds special ResourceMark for deoptimization
 909 
 910   intptr_t*      _must_deopt_id;                 // id of frame that needs to be deopted once we
 911                                                  // transition out of native
 912   CompiledMethod*       _deopt_nmethod;         // CompiledMethod that is currently being deoptimized
 913   vframeArray*  _vframe_array_head;              // Holds the heap of the active vframeArrays
 914   vframeArray*  _vframe_array_last;              // Holds last vFrameArray we popped
 915   // Because deoptimization is lazy we must save jvmti requests to set locals
 916   // in compiled frames until we deoptimize and we have an interpreter frame.
 917   // This holds the pointer to array (yeah like there might be more than one) of
 918   // description of compiled vframes that have locals that need to be updated.
 919   GrowableArray<jvmtiDeferredLocalVariableSet*>* _deferred_locals_updates;
 920 
 921   // Handshake value for fixing 6243940. We need a place for the i2c
 922   // adapter to store the callee Method*. This value is NEVER live
 923   // across a gc point so it does NOT have to be gc'd
 924   // The handshake is open ended since we can't be certain that it will
 925   // be NULLed. This is because we rarely ever see the race and end up
 926   // in handle_wrong_method which is the backend of the handshake. See
 927   // code in i2c adapters and handle_wrong_method.
 928 
 929   Method*       _callee_target;
 930 
 931   // Used to pass back results to the interpreter or generated code running Java code.
 932   oop           _vm_result;    // oop result is GC-preserved
 933   Metadata*     _vm_result_2;  // non-oop result
 934 
 935   // See ReduceInitialCardMarks: this holds the precise space interval of
 936   // the most recent slow path allocation for which compiled code has
 937   // elided card-marks for performance along the fast-path.
 938   MemRegion     _deferred_card_mark;
 939 
 940   MonitorChunk* _monitor_chunks;                 // Contains the off stack monitors
 941                                                  // allocated during deoptimization
 942                                                  // and by JNI_MonitorEnter/Exit
 943 
 944   // Async. requests support
 945   enum AsyncRequests {
 946     _no_async_condition = 0,
 947     _async_exception,
 948     _async_unsafe_access_error
 949   };
 950   AsyncRequests _special_runtime_exit_condition; // Enum indicating pending async. request
 951   oop           _pending_async_exception;
 952 
 953   // Safepoint support
 954  public:                                         // Expose _thread_state for SafeFetchInt()
 955   volatile JavaThreadState _thread_state;
 956  private:
 957   ThreadSafepointState *_safepoint_state;        // Holds information about a thread during a safepoint
 958   address               _saved_exception_pc;     // Saved pc of instruction where last implicit exception happened
 959 
 960   // JavaThread termination support
 961   enum TerminatedTypes {
 962     _not_terminated = 0xDEAD - 2,
 963     _thread_exiting,                             // JavaThread::exit() has been called for this thread
 964     _thread_terminated,                          // JavaThread is removed from thread list
 965     _vm_exited                                   // JavaThread is still executing native code, but VM is terminated
 966                                                  // only VM_Exit can set _vm_exited
 967   };
 968 
 969   // In general a JavaThread's _terminated field transitions as follows:
 970   //
 971   //   _not_terminated => _thread_exiting => _thread_terminated
 972   //
 973   // _vm_exited is a special value to cover the case of a JavaThread
 974   // executing native code after the VM itself is terminated.
 975   volatile TerminatedTypes _terminated;
 976   // suspend/resume support
 977   volatile bool         _suspend_equivalent;     // Suspend equivalent condition
 978   jint                  _in_deopt_handler;       // count of deoptimization
 979                                                  // handlers thread is in
 980   volatile bool         _doing_unsafe_access;    // Thread may fault due to unsafe access
 981   bool                  _do_not_unlock_if_synchronized;  // Do not unlock the receiver of a synchronized method (since it was
 982                                                          // never locked) when throwing an exception. Used by interpreter only.
 983 
 984   // JNI attach states:
 985   enum JNIAttachStates {
 986     _not_attaching_via_jni = 1,  // thread is not attaching via JNI
 987     _attaching_via_jni,          // thread is attaching via JNI
 988     _attached_via_jni            // thread has attached via JNI
 989   };
 990 
 991   // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
 992   // A native thread that is attaching via JNI starts with a value
 993   // of _attaching_via_jni and transitions to _attached_via_jni.
 994   volatile JNIAttachStates _jni_attach_state;
 995 
 996  public:
 997   // State of the stack guard pages for this thread.
 998   enum StackGuardState {
 999     stack_guard_unused,         // not needed
1000     stack_guard_reserved_disabled,
1001     stack_guard_yellow_reserved_disabled,// disabled (temporarily) after stack overflow
1002     stack_guard_enabled         // enabled
1003   };
1004 
1005  private:
1006 
1007 #if INCLUDE_JVMCI
1008   // The _pending_* fields below are used to communicate extra information
1009   // from an uncommon trap in JVMCI compiled code to the uncommon trap handler.
1010 
1011   // Communicates the DeoptReason and DeoptAction of the uncommon trap
1012   int       _pending_deoptimization;
1013 
1014   // Specifies whether the uncommon trap is to bci 0 of a synchronized method
1015   // before the monitor has been acquired.
1016   bool      _pending_monitorenter;
1017 
1018   // Specifies if the DeoptReason for the last uncommon trap was Reason_transfer_to_interpreter
1019   bool      _pending_transfer_to_interpreter;
1020 
1021   // Guard for re-entrant call to JVMCIRuntime::adjust_comp_level
1022   bool      _adjusting_comp_level;
1023 
1024   // An id of a speculation that JVMCI compiled code can use to further describe and
1025   // uniquely identify the  speculative optimization guarded by the uncommon trap
1026   long       _pending_failed_speculation;
1027 
1028   // These fields are mutually exclusive in terms of live ranges.
1029   union {
1030     // Communicates the pc at which the most recent implicit exception occurred
1031     // from the signal handler to a deoptimization stub.
1032     address   _implicit_exception_pc;
1033 
1034     // Communicates an alternative call target to an i2c stub from a JavaCall .
1035     address   _alternate_call_target;
1036   } _jvmci;
1037 
1038   // Support for high precision, thread sensitive counters in JVMCI compiled code.
1039   jlong*    _jvmci_counters;
1040 
1041  public:
1042   static jlong* _jvmci_old_thread_counters;
1043   static void collect_counters(typeArrayOop array);
1044  private:
1045 #endif // INCLUDE_JVMCI
1046 
1047   StackGuardState  _stack_guard_state;
1048 
1049   // Precompute the limit of the stack as used in stack overflow checks.
1050   // We load it from here to simplify the stack overflow check in assembly.
1051   address          _stack_overflow_limit;
1052   address          _reserved_stack_activation;
1053 
1054   // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
1055   // used to temp. parsing values into and out of the runtime system during exception handling for compiled
1056   // code)
1057   volatile oop     _exception_oop;               // Exception thrown in compiled code
1058   volatile address _exception_pc;                // PC where exception happened
1059   volatile address _exception_handler_pc;        // PC for handler of exception
1060   volatile int     _is_method_handle_return;     // true (== 1) if the current exception PC is a MethodHandle call site.
1061 
1062  private:
1063   // support for JNI critical regions
1064   jint    _jni_active_critical;                  // count of entries into JNI critical region
1065 
1066   // Checked JNI: function name requires exception check
1067   char* _pending_jni_exception_check_fn;
1068 
1069   // For deadlock detection.
1070   int _depth_first_number;
1071 
1072   // JVMTI PopFrame support
1073   // This is set to popframe_pending to signal that top Java frame should be popped immediately
1074   int _popframe_condition;
1075 
1076   // If reallocation of scalar replaced objects fails, we throw OOM
1077   // and during exception propagation, pop the top
1078   // _frames_to_pop_failed_realloc frames, the ones that reference
1079   // failed reallocations.
1080   int _frames_to_pop_failed_realloc;
1081 
1082 #ifndef PRODUCT
1083   int _jmp_ring_index;
1084   struct {
1085     // We use intptr_t instead of address so debugger doesn't try and display strings
1086     intptr_t _target;
1087     intptr_t _instruction;
1088     const char*  _file;
1089     int _line;
1090   }   _jmp_ring[jump_ring_buffer_size];
1091 #endif // PRODUCT
1092 
1093   friend class VMThread;
1094   friend class ThreadWaitTransition;
1095   friend class VM_Exit;
1096 
1097   void initialize();                             // Initialized the instance variables
1098 
1099  public:
1100   // Constructor
1101   JavaThread(bool is_attaching_via_jni = false); // for main thread and JNI attached threads
1102   JavaThread(ThreadFunction entry_point, size_t stack_size = 0);
1103   ~JavaThread();
1104 
1105 #ifdef ASSERT
1106   // verify this JavaThread hasn't be published in the Threads::list yet
1107   void verify_not_published();
1108 #endif
1109 
1110   //JNI functiontable getter/setter for JVMTI jni function table interception API.
1111   void set_jni_functions(struct JNINativeInterface_* functionTable) {
1112     _jni_environment.functions = functionTable;
1113   }
1114   struct JNINativeInterface_* get_jni_functions() {
1115     return (struct JNINativeInterface_ *)_jni_environment.functions;
1116   }
1117 
1118   // This function is called at thread creation to allow
1119   // platform specific thread variables to be initialized.
1120   void cache_global_variables();
1121 
1122   // Executes Shutdown.shutdown()
1123   void invoke_shutdown_hooks();
1124 
1125   // Cleanup on thread exit
1126   enum ExitType {
1127     normal_exit,
1128     jni_detach
1129   };
1130   void exit(bool destroy_vm, ExitType exit_type = normal_exit);
1131 
1132   void cleanup_failed_attach_current_thread();
1133 
1134   // Testers
1135   virtual bool is_Java_thread() const            { return true;  }
1136   virtual bool can_call_java() const             { return true; }
1137 
1138   // Thread chain operations
1139   JavaThread* next() const                       { return _next; }
1140   void set_next(JavaThread* p)                   { _next = p; }
1141 
1142   // Thread oop. threadObj() can be NULL for initial JavaThread
1143   // (or for threads attached via JNI)
1144   oop threadObj() const                          { return _threadObj; }
1145   void set_threadObj(oop p)                      { _threadObj = p; }
1146 
1147   ThreadPriority java_priority() const;          // Read from threadObj()
1148 
1149   // Prepare thread and add to priority queue.  If a priority is
1150   // not specified, use the priority of the thread object. Threads_lock
1151   // must be held while this function is called.
1152   void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
1153 
1154   void set_saved_exception_pc(address pc)        { _saved_exception_pc = pc; }
1155   address saved_exception_pc()                   { return _saved_exception_pc; }
1156 
1157 
1158   ThreadFunction entry_point() const             { return _entry_point; }
1159 
1160   // Allocates a new Java level thread object for this thread. thread_name may be NULL.
1161   void allocate_threadObj(Handle thread_group, const char* thread_name, bool daemon, TRAPS);
1162 
1163   // Last frame anchor routines
1164 
1165   JavaFrameAnchor* frame_anchor(void)            { return &_anchor; }
1166 
1167   // last_Java_sp
1168   bool has_last_Java_frame() const               { return _anchor.has_last_Java_frame(); }
1169   intptr_t* last_Java_sp() const                 { return _anchor.last_Java_sp(); }
1170 
1171   // last_Java_pc
1172 
1173   address last_Java_pc(void)                     { return _anchor.last_Java_pc(); }
1174 
1175   // Safepoint support
1176 #if !(defined(PPC64) || defined(AARCH64))
1177   JavaThreadState thread_state() const           { return _thread_state; }
1178   void set_thread_state(JavaThreadState s)       { _thread_state = s;    }
1179 #else
1180   // Use membars when accessing volatile _thread_state. See
1181   // Threads::create_vm() for size checks.
1182   inline JavaThreadState thread_state() const;
1183   inline void set_thread_state(JavaThreadState s);
1184 #endif
1185   ThreadSafepointState *safepoint_state() const  { return _safepoint_state; }
1186   void set_safepoint_state(ThreadSafepointState *state) { _safepoint_state = state; }
1187   bool is_at_poll_safepoint()                    { return _safepoint_state->is_at_poll_safepoint(); }
1188 
1189   // JavaThread termination and lifecycle support:
1190   void smr_delete();
1191   bool on_thread_list() const { return _on_thread_list; }
1192   void set_on_thread_list() { _on_thread_list = true; }
1193 
1194   // thread has called JavaThread::exit() or is terminated
1195   bool is_exiting() const;
1196   // thread is terminated (no longer on the threads list); we compare
1197   // against the two non-terminated values so that a freed JavaThread
1198   // will also be considered terminated.
1199   bool check_is_terminated(TerminatedTypes l_terminated) const {
1200     return l_terminated != _not_terminated && l_terminated != _thread_exiting;
1201   }
1202   bool is_terminated() const;
1203   void set_terminated(TerminatedTypes t);
1204   // special for Threads::remove() which is static:
1205   void set_terminated_value();
1206   void block_if_vm_exited();
1207 
1208   bool doing_unsafe_access()                     { return _doing_unsafe_access; }
1209   void set_doing_unsafe_access(bool val)         { _doing_unsafe_access = val; }
1210 
1211   bool do_not_unlock_if_synchronized()             { return _do_not_unlock_if_synchronized; }
1212   void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
1213 
1214   inline void set_polling_page_release(void* poll_value);
1215   inline void set_polling_page(void* poll_value);
1216   inline volatile void* get_polling_page();
1217 
1218  private:
1219   // Support for thread handshake operations
1220   HandshakeState _handshake;
1221  public:
1222   void set_handshake_operation(HandshakeOperation* op) {
1223     _handshake.set_operation(this, op);
1224   }
1225 
1226   bool has_handshake() const {
1227     return _handshake.has_operation();
1228   }
1229 
1230   void cancel_handshake() {
1231     _handshake.cancel(this);
1232   }
1233 
1234   void handshake_process_by_self() {
1235     _handshake.process_by_self(this);
1236   }
1237 
1238   void handshake_process_by_vmthread() {
1239     _handshake.process_by_vmthread(this);
1240   }
1241 
1242   // Suspend/resume support for JavaThread
1243  private:
1244   inline void set_ext_suspended();
1245   inline void clear_ext_suspended();
1246 
1247  public:
1248   void java_suspend();
1249   void java_resume();
1250   int  java_suspend_self();
1251 
1252   void check_and_wait_while_suspended() {
1253     assert(JavaThread::current() == this, "sanity check");
1254 
1255     bool do_self_suspend;
1256     do {
1257       // were we externally suspended while we were waiting?
1258       do_self_suspend = handle_special_suspend_equivalent_condition();
1259       if (do_self_suspend) {
1260         // don't surprise the thread that suspended us by returning
1261         java_suspend_self();
1262         set_suspend_equivalent();
1263       }
1264     } while (do_self_suspend);
1265   }
1266   static void check_safepoint_and_suspend_for_native_trans(JavaThread *thread);
1267   // Check for async exception in addition to safepoint and suspend request.
1268   static void check_special_condition_for_native_trans(JavaThread *thread);
1269 
1270   // Same as check_special_condition_for_native_trans but finishes the
1271   // transition into thread_in_Java mode so that it can potentially
1272   // block.
1273   static void check_special_condition_for_native_trans_and_transition(JavaThread *thread);
1274 
1275   bool is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits);
1276   bool is_ext_suspend_completed_with_lock(uint32_t *bits) {
1277     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1278     // Warning: is_ext_suspend_completed() may temporarily drop the
1279     // SR_lock to allow the thread to reach a stable thread state if
1280     // it is currently in a transient thread state.
1281     return is_ext_suspend_completed(false /* !called_by_wait */,
1282                                     SuspendRetryDelay, bits);
1283   }
1284 
1285   // We cannot allow wait_for_ext_suspend_completion() to run forever or
1286   // we could hang. SuspendRetryCount and SuspendRetryDelay are normally
1287   // passed as the count and delay parameters. Experiments with specific
1288   // calls to wait_for_ext_suspend_completion() can be done by passing
1289   // other values in the code. Experiments with all calls can be done
1290   // via the appropriate -XX options.
1291   bool wait_for_ext_suspend_completion(int count, int delay, uint32_t *bits);
1292 
1293   // test for suspend - most (all?) of these should go away
1294   bool is_thread_fully_suspended(bool wait_for_suspend, uint32_t *bits);
1295 
1296   inline void set_external_suspend();
1297   inline void clear_external_suspend();
1298 
1299   inline void set_deopt_suspend();
1300   inline void clear_deopt_suspend();
1301   bool is_deopt_suspend()         { return (_suspend_flags & _deopt_suspend) != 0; }
1302 
1303   bool is_external_suspend() const {
1304     return (_suspend_flags & _external_suspend) != 0;
1305   }
1306   // Whenever a thread transitions from native to vm/java it must suspend
1307   // if external|deopt suspend is present.
1308   bool is_suspend_after_native() const {
1309     return (_suspend_flags & (_external_suspend | _deopt_suspend)) != 0;
1310   }
1311 
1312   // external suspend request is completed
1313   bool is_ext_suspended() const {
1314     return (_suspend_flags & _ext_suspended) != 0;
1315   }
1316 
1317   bool is_external_suspend_with_lock() const {
1318     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1319     return is_external_suspend();
1320   }
1321 
1322   // Special method to handle a pending external suspend request
1323   // when a suspend equivalent condition lifts.
1324   bool handle_special_suspend_equivalent_condition() {
1325     assert(is_suspend_equivalent(),
1326            "should only be called in a suspend equivalence condition");
1327     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1328     bool ret = is_external_suspend();
1329     if (!ret) {
1330       // not about to self-suspend so clear suspend equivalence
1331       clear_suspend_equivalent();
1332     }
1333     // implied else:
1334     // We have a pending external suspend request so we leave the
1335     // suspend_equivalent flag set until java_suspend_self() sets
1336     // the ext_suspended flag and clears the suspend_equivalent
1337     // flag. This insures that wait_for_ext_suspend_completion()
1338     // will return consistent values.
1339     return ret;
1340   }
1341 
1342   // utility methods to see if we are doing some kind of suspension
1343   bool is_being_ext_suspended() const            {
1344     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1345     return is_ext_suspended() || is_external_suspend();
1346   }
1347 
1348   bool is_suspend_equivalent() const             { return _suspend_equivalent; }
1349 
1350   void set_suspend_equivalent()                  { _suspend_equivalent = true; }
1351   void clear_suspend_equivalent()                { _suspend_equivalent = false; }
1352 
1353   // Thread.stop support
1354   void send_thread_stop(oop throwable);
1355   AsyncRequests clear_special_runtime_exit_condition() {
1356     AsyncRequests x = _special_runtime_exit_condition;
1357     _special_runtime_exit_condition = _no_async_condition;
1358     return x;
1359   }
1360 
1361   // Are any async conditions present?
1362   bool has_async_condition() { return (_special_runtime_exit_condition != _no_async_condition); }
1363 
1364   void check_and_handle_async_exceptions(bool check_unsafe_error = true);
1365 
1366   // these next two are also used for self-suspension and async exception support
1367   void handle_special_runtime_exit_condition(bool check_asyncs = true);
1368 
1369   // Return true if JavaThread has an asynchronous condition or
1370   // if external suspension is requested.
1371   bool has_special_runtime_exit_condition() {
1372     // Because we don't use is_external_suspend_with_lock
1373     // it is possible that we won't see an asynchronous external suspend
1374     // request that has just gotten started, i.e., SR_lock grabbed but
1375     // _external_suspend field change either not made yet or not visible
1376     // yet. However, this is okay because the request is asynchronous and
1377     // we will see the new flag value the next time through. It's also
1378     // possible that the external suspend request is dropped after
1379     // we have checked is_external_suspend(), we will recheck its value
1380     // under SR_lock in java_suspend_self().
1381     return (_special_runtime_exit_condition != _no_async_condition) ||
1382             is_external_suspend() || is_trace_suspend();
1383   }
1384 
1385   void set_pending_unsafe_access_error()          { _special_runtime_exit_condition = _async_unsafe_access_error; }
1386 
1387   inline void set_pending_async_exception(oop e);
1388 
1389   // Fast-locking support
1390   bool is_lock_owned(address adr) const;
1391 
1392   // Accessors for vframe array top
1393   // The linked list of vframe arrays are sorted on sp. This means when we
1394   // unpack the head must contain the vframe array to unpack.
1395   void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
1396   vframeArray* vframe_array_head() const         { return _vframe_array_head;  }
1397 
1398   // Side structure for deferring update of java frame locals until deopt occurs
1399   GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred_locals() const { return _deferred_locals_updates; }
1400   void set_deferred_locals(GrowableArray<jvmtiDeferredLocalVariableSet *>* vf) { _deferred_locals_updates = vf; }
1401 
1402   // These only really exist to make debugging deopt problems simpler
1403 
1404   void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
1405   vframeArray* vframe_array_last() const         { return _vframe_array_last;  }
1406 
1407   // The special resourceMark used during deoptimization
1408 
1409   void set_deopt_mark(DeoptResourceMark* value)  { _deopt_mark = value; }
1410   DeoptResourceMark* deopt_mark(void)            { return _deopt_mark; }
1411 
1412   intptr_t* must_deopt_id()                      { return _must_deopt_id; }
1413   void     set_must_deopt_id(intptr_t* id)       { _must_deopt_id = id; }
1414   void     clear_must_deopt_id()                 { _must_deopt_id = NULL; }
1415 
1416   void set_deopt_compiled_method(CompiledMethod* nm)  { _deopt_nmethod = nm; }
1417   CompiledMethod* deopt_compiled_method()        { return _deopt_nmethod; }
1418 
1419   Method*    callee_target() const               { return _callee_target; }
1420   void set_callee_target  (Method* x)          { _callee_target   = x; }
1421 
1422   // Oop results of vm runtime calls
1423   oop  vm_result() const                         { return _vm_result; }
1424   void set_vm_result  (oop x)                    { _vm_result   = x; }
1425 
1426   Metadata*    vm_result_2() const               { return _vm_result_2; }
1427   void set_vm_result_2  (Metadata* x)          { _vm_result_2   = x; }
1428 
1429   MemRegion deferred_card_mark() const           { return _deferred_card_mark; }
1430   void set_deferred_card_mark(MemRegion mr)      { _deferred_card_mark = mr;   }
1431 
1432 #if INCLUDE_JVMCI
1433   int  pending_deoptimization() const             { return _pending_deoptimization; }
1434   long  pending_failed_speculation() const         { return _pending_failed_speculation; }
1435   bool adjusting_comp_level() const               { return _adjusting_comp_level; }
1436   void set_adjusting_comp_level(bool b)           { _adjusting_comp_level = b; }
1437   bool has_pending_monitorenter() const           { return _pending_monitorenter; }
1438   void set_pending_monitorenter(bool b)           { _pending_monitorenter = b; }
1439   void set_pending_deoptimization(int reason)     { _pending_deoptimization = reason; }
1440   void set_pending_failed_speculation(long failed_speculation) { _pending_failed_speculation = failed_speculation; }
1441   void set_pending_transfer_to_interpreter(bool b) { _pending_transfer_to_interpreter = b; }
1442   void set_jvmci_alternate_call_target(address a) { assert(_jvmci._alternate_call_target == NULL, "must be"); _jvmci._alternate_call_target = a; }
1443   void set_jvmci_implicit_exception_pc(address a) { assert(_jvmci._implicit_exception_pc == NULL, "must be"); _jvmci._implicit_exception_pc = a; }
1444 #endif // INCLUDE_JVMCI
1445 
1446   // Exception handling for compiled methods
1447   oop      exception_oop() const                 { return _exception_oop; }
1448   address  exception_pc() const                  { return _exception_pc; }
1449   address  exception_handler_pc() const          { return _exception_handler_pc; }
1450   bool     is_method_handle_return() const       { return _is_method_handle_return == 1; }
1451 
1452   void set_exception_oop(oop o)                  { (void)const_cast<oop&>(_exception_oop = o); }
1453   void set_exception_pc(address a)               { _exception_pc = a; }
1454   void set_exception_handler_pc(address a)       { _exception_handler_pc = a; }
1455   void set_is_method_handle_return(bool value)   { _is_method_handle_return = value ? 1 : 0; }
1456 
1457   void clear_exception_oop_and_pc() {
1458     set_exception_oop(NULL);
1459     set_exception_pc(NULL);
1460   }
1461 
1462   // Stack overflow support
1463   //
1464   //  (small addresses)
1465   //
1466   //  --  <-- stack_end()                   ---
1467   //  |                                      |
1468   //  |  red pages                           |
1469   //  |                                      |
1470   //  --  <-- stack_red_zone_base()          |
1471   //  |                                      |
1472   //  |                                     guard
1473   //  |  yellow pages                       zone
1474   //  |                                      |
1475   //  |                                      |
1476   //  --  <-- stack_yellow_zone_base()       |
1477   //  |                                      |
1478   //  |                                      |
1479   //  |  reserved pages                      |
1480   //  |                                      |
1481   //  --  <-- stack_reserved_zone_base()    ---      ---
1482   //                                                 /|\  shadow     <--  stack_overflow_limit() (somewhere in here)
1483   //                                                  |   zone
1484   //                                                 \|/  size
1485   //  some untouched memory                          ---
1486   //
1487   //
1488   //  --
1489   //  |
1490   //  |  shadow zone
1491   //  |
1492   //  --
1493   //  x    frame n
1494   //  --
1495   //  x    frame n-1
1496   //  x
1497   //  --
1498   //  ...
1499   //
1500   //  --
1501   //  x    frame 0
1502   //  --  <-- stack_base()
1503   //
1504   //  (large addresses)
1505   //
1506 
1507  private:
1508   // These values are derived from flags StackRedPages, StackYellowPages,
1509   // StackReservedPages and StackShadowPages. The zone size is determined
1510   // ergonomically if page_size > 4K.
1511   static size_t _stack_red_zone_size;
1512   static size_t _stack_yellow_zone_size;
1513   static size_t _stack_reserved_zone_size;
1514   static size_t _stack_shadow_zone_size;
1515  public:
1516   inline size_t stack_available(address cur_sp);
1517 
1518   static size_t stack_red_zone_size() {
1519     assert(_stack_red_zone_size > 0, "Don't call this before the field is initialized.");
1520     return _stack_red_zone_size;
1521   }
1522   static void set_stack_red_zone_size(size_t s) {
1523     assert(is_aligned(s, os::vm_page_size()),
1524            "We can not protect if the red zone size is not page aligned.");
1525     assert(_stack_red_zone_size == 0, "This should be called only once.");
1526     _stack_red_zone_size = s;
1527   }
1528   address stack_red_zone_base() {
1529     return (address)(stack_end() + stack_red_zone_size());
1530   }
1531   bool in_stack_red_zone(address a) {
1532     return a <= stack_red_zone_base() && a >= stack_end();
1533   }
1534 
1535   static size_t stack_yellow_zone_size() {
1536     assert(_stack_yellow_zone_size > 0, "Don't call this before the field is initialized.");
1537     return _stack_yellow_zone_size;
1538   }
1539   static void set_stack_yellow_zone_size(size_t s) {
1540     assert(is_aligned(s, os::vm_page_size()),
1541            "We can not protect if the yellow zone size is not page aligned.");
1542     assert(_stack_yellow_zone_size == 0, "This should be called only once.");
1543     _stack_yellow_zone_size = s;
1544   }
1545 
1546   static size_t stack_reserved_zone_size() {
1547     // _stack_reserved_zone_size may be 0. This indicates the feature is off.
1548     return _stack_reserved_zone_size;
1549   }
1550   static void set_stack_reserved_zone_size(size_t s) {
1551     assert(is_aligned(s, os::vm_page_size()),
1552            "We can not protect if the reserved zone size is not page aligned.");
1553     assert(_stack_reserved_zone_size == 0, "This should be called only once.");
1554     _stack_reserved_zone_size = s;
1555   }
1556   address stack_reserved_zone_base() {
1557     return (address)(stack_end() +
1558                      (stack_red_zone_size() + stack_yellow_zone_size() + stack_reserved_zone_size()));
1559   }
1560   bool in_stack_reserved_zone(address a) {
1561     return (a <= stack_reserved_zone_base()) &&
1562            (a >= (address)((intptr_t)stack_reserved_zone_base() - stack_reserved_zone_size()));
1563   }
1564 
1565   static size_t stack_yellow_reserved_zone_size() {
1566     return _stack_yellow_zone_size + _stack_reserved_zone_size;
1567   }
1568   bool in_stack_yellow_reserved_zone(address a) {
1569     return (a <= stack_reserved_zone_base()) && (a >= stack_red_zone_base());
1570   }
1571 
1572   // Size of red + yellow + reserved zones.
1573   static size_t stack_guard_zone_size() {
1574     return stack_red_zone_size() + stack_yellow_reserved_zone_size();
1575   }
1576 
1577   static size_t stack_shadow_zone_size() {
1578     assert(_stack_shadow_zone_size > 0, "Don't call this before the field is initialized.");
1579     return _stack_shadow_zone_size;
1580   }
1581   static void set_stack_shadow_zone_size(size_t s) {
1582     // The shadow area is not allocated or protected, so
1583     // it needs not be page aligned.
1584     // But the stack bang currently assumes that it is a
1585     // multiple of page size. This guarantees that the bang
1586     // loop touches all pages in the shadow zone.
1587     // This can be guaranteed differently, as well.  E.g., if
1588     // the page size is a multiple of 4K, banging in 4K steps
1589     // suffices to touch all pages. (Some pages are banged
1590     // several times, though.)
1591     assert(is_aligned(s, os::vm_page_size()),
1592            "Stack bang assumes multiple of page size.");
1593     assert(_stack_shadow_zone_size == 0, "This should be called only once.");
1594     _stack_shadow_zone_size = s;
1595   }
1596 
1597   void create_stack_guard_pages();
1598   void remove_stack_guard_pages();
1599 
1600   void enable_stack_reserved_zone();
1601   void disable_stack_reserved_zone();
1602   void enable_stack_yellow_reserved_zone();
1603   void disable_stack_yellow_reserved_zone();
1604   void enable_stack_red_zone();
1605   void disable_stack_red_zone();
1606 
1607   inline bool stack_guard_zone_unused();
1608   inline bool stack_yellow_reserved_zone_disabled();
1609   inline bool stack_reserved_zone_disabled();
1610   inline bool stack_guards_enabled();
1611 
1612   address reserved_stack_activation() const { return _reserved_stack_activation; }
1613   void set_reserved_stack_activation(address addr) {
1614     assert(_reserved_stack_activation == stack_base()
1615             || _reserved_stack_activation == NULL
1616             || addr == stack_base(), "Must not be set twice");
1617     _reserved_stack_activation = addr;
1618   }
1619 
1620   // Attempt to reguard the stack after a stack overflow may have occurred.
1621   // Returns true if (a) guard pages are not needed on this thread, (b) the
1622   // pages are already guarded, or (c) the pages were successfully reguarded.
1623   // Returns false if there is not enough stack space to reguard the pages, in
1624   // which case the caller should unwind a frame and try again.  The argument
1625   // should be the caller's (approximate) sp.
1626   bool reguard_stack(address cur_sp);
1627   // Similar to above but see if current stackpoint is out of the guard area
1628   // and reguard if possible.
1629   bool reguard_stack(void);
1630 
1631   address stack_overflow_limit() { return _stack_overflow_limit; }
1632   void set_stack_overflow_limit() {
1633     _stack_overflow_limit =
1634       stack_end() + MAX2(JavaThread::stack_guard_zone_size(), JavaThread::stack_shadow_zone_size());
1635   }
1636 
1637   // Misc. accessors/mutators
1638   void set_do_not_unlock(void)                   { _do_not_unlock_if_synchronized = true; }
1639   void clr_do_not_unlock(void)                   { _do_not_unlock_if_synchronized = false; }
1640   bool do_not_unlock(void)                       { return _do_not_unlock_if_synchronized; }
1641 
1642 #ifndef PRODUCT
1643   void record_jump(address target, address instr, const char* file, int line);
1644 #endif // PRODUCT
1645 
1646   // For assembly stub generation
1647   static ByteSize threadObj_offset()             { return byte_offset_of(JavaThread, _threadObj); }
1648 #ifndef PRODUCT
1649   static ByteSize jmp_ring_index_offset()        { return byte_offset_of(JavaThread, _jmp_ring_index); }
1650   static ByteSize jmp_ring_offset()              { return byte_offset_of(JavaThread, _jmp_ring); }
1651 #endif // PRODUCT
1652   static ByteSize jni_environment_offset()       { return byte_offset_of(JavaThread, _jni_environment); }
1653   static ByteSize pending_jni_exception_check_fn_offset() {
1654     return byte_offset_of(JavaThread, _pending_jni_exception_check_fn);
1655   }
1656   static ByteSize last_Java_sp_offset() {
1657     return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
1658   }
1659   static ByteSize last_Java_pc_offset() {
1660     return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
1661   }
1662   static ByteSize frame_anchor_offset() {
1663     return byte_offset_of(JavaThread, _anchor);
1664   }
1665   static ByteSize callee_target_offset()         { return byte_offset_of(JavaThread, _callee_target); }
1666   static ByteSize vm_result_offset()             { return byte_offset_of(JavaThread, _vm_result); }
1667   static ByteSize vm_result_2_offset()           { return byte_offset_of(JavaThread, _vm_result_2); }
1668   static ByteSize thread_state_offset()          { return byte_offset_of(JavaThread, _thread_state); }
1669   static ByteSize saved_exception_pc_offset()    { return byte_offset_of(JavaThread, _saved_exception_pc); }
1670   static ByteSize osthread_offset()              { return byte_offset_of(JavaThread, _osthread); }
1671 #if INCLUDE_JVMCI
1672   static ByteSize pending_deoptimization_offset() { return byte_offset_of(JavaThread, _pending_deoptimization); }
1673   static ByteSize pending_monitorenter_offset()  { return byte_offset_of(JavaThread, _pending_monitorenter); }
1674   static ByteSize pending_failed_speculation_offset() { return byte_offset_of(JavaThread, _pending_failed_speculation); }
1675   static ByteSize jvmci_alternate_call_target_offset() { return byte_offset_of(JavaThread, _jvmci._alternate_call_target); }
1676   static ByteSize jvmci_implicit_exception_pc_offset() { return byte_offset_of(JavaThread, _jvmci._implicit_exception_pc); }
1677   static ByteSize jvmci_counters_offset()        { return byte_offset_of(JavaThread, _jvmci_counters); }
1678 #endif // INCLUDE_JVMCI
1679   static ByteSize exception_oop_offset()         { return byte_offset_of(JavaThread, _exception_oop); }
1680   static ByteSize exception_pc_offset()          { return byte_offset_of(JavaThread, _exception_pc); }
1681   static ByteSize exception_handler_pc_offset()  { return byte_offset_of(JavaThread, _exception_handler_pc); }
1682   static ByteSize stack_overflow_limit_offset()  { return byte_offset_of(JavaThread, _stack_overflow_limit); }
1683   static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); }
1684   static ByteSize stack_guard_state_offset()     { return byte_offset_of(JavaThread, _stack_guard_state); }
1685   static ByteSize reserved_stack_activation_offset() { return byte_offset_of(JavaThread, _reserved_stack_activation); }
1686   static ByteSize suspend_flags_offset()         { return byte_offset_of(JavaThread, _suspend_flags); }
1687 
1688   static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
1689   static ByteSize should_post_on_exceptions_flag_offset() {
1690     return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
1691   }
1692 
1693   // Returns the jni environment for this thread
1694   JNIEnv* jni_environment()                      { return &_jni_environment; }
1695 
1696   static JavaThread* thread_from_jni_environment(JNIEnv* env) {
1697     JavaThread *thread_from_jni_env = (JavaThread*)((intptr_t)env - in_bytes(jni_environment_offset()));
1698     // Only return NULL if thread is off the thread list; starting to
1699     // exit should not return NULL.
1700     if (thread_from_jni_env->is_terminated()) {
1701       thread_from_jni_env->block_if_vm_exited();
1702       return NULL;
1703     } else {
1704       return thread_from_jni_env;
1705     }
1706   }
1707 
1708   // JNI critical regions. These can nest.
1709   bool in_critical()    { return _jni_active_critical > 0; }
1710   bool in_last_critical()  { return _jni_active_critical == 1; }
1711   void enter_critical() {
1712     assert(Thread::current() == this ||
1713            (Thread::current()->is_VM_thread() &&
1714            SafepointSynchronize::is_synchronizing()),
1715            "this must be current thread or synchronizing");
1716     _jni_active_critical++;
1717   }
1718   void exit_critical() {
1719     assert(Thread::current() == this, "this must be current thread");
1720     _jni_active_critical--;
1721     assert(_jni_active_critical >= 0, "JNI critical nesting problem?");
1722   }
1723 
1724   // Checked JNI: is the programmer required to check for exceptions, if so specify
1725   // which function name. Returning to a Java frame should implicitly clear the
1726   // pending check, this is done for Native->Java transitions (i.e. user JNI code).
1727   // VM->Java transistions are not cleared, it is expected that JNI code enclosed
1728   // within ThreadToNativeFromVM makes proper exception checks (i.e. VM internal).
1729   bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != NULL; }
1730   void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = NULL; }
1731   const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; }
1732   void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; }
1733 
1734   // For deadlock detection
1735   int depth_first_number() { return _depth_first_number; }
1736   void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
1737 
1738  private:
1739   void set_monitor_chunks(MonitorChunk* monitor_chunks) { _monitor_chunks = monitor_chunks; }
1740 
1741  public:
1742   MonitorChunk* monitor_chunks() const           { return _monitor_chunks; }
1743   void add_monitor_chunk(MonitorChunk* chunk);
1744   void remove_monitor_chunk(MonitorChunk* chunk);
1745   bool in_deopt_handler() const                  { return _in_deopt_handler > 0; }
1746   void inc_in_deopt_handler()                    { _in_deopt_handler++; }
1747   void dec_in_deopt_handler() {
1748     assert(_in_deopt_handler > 0, "mismatched deopt nesting");
1749     if (_in_deopt_handler > 0) { // robustness
1750       _in_deopt_handler--;
1751     }
1752   }
1753 
1754  private:
1755   void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
1756 
1757  public:
1758 
1759   // Frame iteration; calls the function f for all frames on the stack
1760   void frames_do(void f(frame*, const RegisterMap*));
1761 
1762   // Memory operations
1763   void oops_do(OopClosure* f, CodeBlobClosure* cf);
1764 
1765   // Sweeper operations
1766   virtual void nmethods_do(CodeBlobClosure* cf);
1767 
1768   // RedefineClasses Support
1769   void metadata_do(void f(Metadata*));
1770 
1771   // Misc. operations
1772   char* name() const { return (char*)get_thread_name(); }
1773   void print_on(outputStream* st, bool print_extended_info) const;
1774   void print_on(outputStream* st) const { print_on(st, false); }
1775   void print_value();
1776   void print_thread_state_on(outputStream*) const      PRODUCT_RETURN;
1777   void print_thread_state() const                      PRODUCT_RETURN;
1778   void print_on_error(outputStream* st, char* buf, int buflen) const;
1779   void print_name_on_error(outputStream* st, char* buf, int buflen) const;
1780   void verify();
1781   const char* get_thread_name() const;
1782  private:
1783   // factor out low-level mechanics for use in both normal and error cases
1784   const char* get_thread_name_string(char* buf = NULL, int buflen = 0) const;
1785  public:
1786   const char* get_threadgroup_name() const;
1787   const char* get_parent_name() const;
1788 
1789   // Accessing frames
1790   frame last_frame() {
1791     _anchor.make_walkable(this);
1792     return pd_last_frame();
1793   }
1794   javaVFrame* last_java_vframe(RegisterMap* reg_map);
1795 
1796   // Returns method at 'depth' java or native frames down the stack
1797   // Used for security checks
1798   Klass* security_get_caller_class(int depth);
1799 
1800   // Print stack trace in external format
1801   void print_stack_on(outputStream* st);
1802   void print_stack() { print_stack_on(tty); }
1803 
1804   // Print stack traces in various internal formats
1805   void trace_stack()                             PRODUCT_RETURN;
1806   void trace_stack_from(vframe* start_vf)        PRODUCT_RETURN;
1807   void trace_frames()                            PRODUCT_RETURN;
1808   void trace_oops()                              PRODUCT_RETURN;
1809 
1810   // Print an annotated view of the stack frames
1811   void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN;
1812   void validate_frame_layout() {
1813     print_frame_layout(0, true);
1814   }
1815 
1816   // Returns the number of stack frames on the stack
1817   int depth() const;
1818 
1819   // Function for testing deoptimization
1820   void deoptimize();
1821   void make_zombies();
1822 
1823   void deoptimized_wrt_marked_nmethods();
1824 
1825  public:
1826   // Returns the running thread as a JavaThread
1827   static inline JavaThread* current();
1828 
1829   // Returns the active Java thread.  Do not use this if you know you are calling
1830   // from a JavaThread, as it's slower than JavaThread::current.  If called from
1831   // the VMThread, it also returns the JavaThread that instigated the VMThread's
1832   // operation.  You may not want that either.
1833   static JavaThread* active();
1834 
1835   inline CompilerThread* as_CompilerThread();
1836 
1837  public:
1838   virtual void run();
1839   void thread_main_inner();
1840 
1841  private:
1842   // PRIVILEGED STACK
1843   PrivilegedElement*  _privileged_stack_top;
1844   GrowableArray<oop>* _array_for_gc;
1845  public:
1846 
1847   // Returns the privileged_stack information.
1848   PrivilegedElement* privileged_stack_top() const       { return _privileged_stack_top; }
1849   void set_privileged_stack_top(PrivilegedElement *e)   { _privileged_stack_top = e; }
1850   void register_array_for_gc(GrowableArray<oop>* array) { _array_for_gc = array; }
1851 
1852  public:
1853   // Thread local information maintained by JVMTI.
1854   void set_jvmti_thread_state(JvmtiThreadState *value)                           { _jvmti_thread_state = value; }
1855   // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1856   // getter is used to get this JavaThread's JvmtiThreadState if it has
1857   // one which means NULL can be returned. JvmtiThreadState::state_for()
1858   // is used to get the specified JavaThread's JvmtiThreadState if it has
1859   // one or it allocates a new JvmtiThreadState for the JavaThread and
1860   // returns it. JvmtiThreadState::state_for() will return NULL only if
1861   // the specified JavaThread is exiting.
1862   JvmtiThreadState *jvmti_thread_state() const                                   { return _jvmti_thread_state; }
1863   static ByteSize jvmti_thread_state_offset()                                    { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1864   void set_jvmti_get_loaded_classes_closure(JvmtiGetLoadedClassesClosure* value) { _jvmti_get_loaded_classes_closure = value; }
1865   JvmtiGetLoadedClassesClosure* get_jvmti_get_loaded_classes_closure() const     { return _jvmti_get_loaded_classes_closure; }
1866 
1867   // JVMTI PopFrame support
1868   // Setting and clearing popframe_condition
1869   // All of these enumerated values are bits. popframe_pending
1870   // indicates that a PopFrame() has been requested and not yet been
1871   // completed. popframe_processing indicates that that PopFrame() is in
1872   // the process of being completed. popframe_force_deopt_reexecution_bit
1873   // indicates that special handling is required when returning to a
1874   // deoptimized caller.
1875   enum PopCondition {
1876     popframe_inactive                      = 0x00,
1877     popframe_pending_bit                   = 0x01,
1878     popframe_processing_bit                = 0x02,
1879     popframe_force_deopt_reexecution_bit   = 0x04
1880   };
1881   PopCondition popframe_condition()                   { return (PopCondition) _popframe_condition; }
1882   void set_popframe_condition(PopCondition c)         { _popframe_condition = c; }
1883   void set_popframe_condition_bit(PopCondition c)     { _popframe_condition |= c; }
1884   void clear_popframe_condition()                     { _popframe_condition = popframe_inactive; }
1885   static ByteSize popframe_condition_offset()         { return byte_offset_of(JavaThread, _popframe_condition); }
1886   bool has_pending_popframe()                         { return (popframe_condition() & popframe_pending_bit) != 0; }
1887   bool popframe_forcing_deopt_reexecution()           { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
1888   void clear_popframe_forcing_deopt_reexecution()     { _popframe_condition &= ~popframe_force_deopt_reexecution_bit; }
1889 #ifdef CC_INTERP
1890   bool pop_frame_pending(void)                        { return ((_popframe_condition & popframe_pending_bit) != 0); }
1891   void clr_pop_frame_pending(void)                    { _popframe_condition = popframe_inactive; }
1892   bool pop_frame_in_process(void)                     { return ((_popframe_condition & popframe_processing_bit) != 0); }
1893   void set_pop_frame_in_process(void)                 { _popframe_condition |= popframe_processing_bit; }
1894   void clr_pop_frame_in_process(void)                 { _popframe_condition &= ~popframe_processing_bit; }
1895 #endif
1896 
1897   int frames_to_pop_failed_realloc() const            { return _frames_to_pop_failed_realloc; }
1898   void set_frames_to_pop_failed_realloc(int nb)       { _frames_to_pop_failed_realloc = nb; }
1899   void dec_frames_to_pop_failed_realloc()             { _frames_to_pop_failed_realloc--; }
1900 
1901  private:
1902   // Saved incoming arguments to popped frame.
1903   // Used only when popped interpreted frame returns to deoptimized frame.
1904   void*    _popframe_preserved_args;
1905   int      _popframe_preserved_args_size;
1906 
1907  public:
1908   void  popframe_preserve_args(ByteSize size_in_bytes, void* start);
1909   void* popframe_preserved_args();
1910   ByteSize popframe_preserved_args_size();
1911   WordSize popframe_preserved_args_size_in_words();
1912   void  popframe_free_preserved_args();
1913 
1914 
1915  private:
1916   JvmtiThreadState *_jvmti_thread_state;
1917   JvmtiGetLoadedClassesClosure* _jvmti_get_loaded_classes_closure;
1918 
1919   // Used by the interpreter in fullspeed mode for frame pop, method
1920   // entry, method exit and single stepping support. This field is
1921   // only set to non-zero by the VM_EnterInterpOnlyMode VM operation.
1922   // It can be set to zero asynchronously (i.e., without a VM operation
1923   // or a lock) so we have to be very careful.
1924   int               _interp_only_mode;
1925 
1926  public:
1927   // used by the interpreter for fullspeed debugging support (see above)
1928   static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
1929   bool is_interp_only_mode()                { return (_interp_only_mode != 0); }
1930   int get_interp_only_mode()                { return _interp_only_mode; }
1931   void increment_interp_only_mode()         { ++_interp_only_mode; }
1932   void decrement_interp_only_mode()         { --_interp_only_mode; }
1933 
1934   // support for cached flag that indicates whether exceptions need to be posted for this thread
1935   // if this is false, we can avoid deoptimizing when events are thrown
1936   // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
1937  private:
1938   int    _should_post_on_exceptions_flag;
1939 
1940  public:
1941   int   should_post_on_exceptions_flag()  { return _should_post_on_exceptions_flag; }
1942   void  set_should_post_on_exceptions_flag(int val)  { _should_post_on_exceptions_flag = val; }
1943 
1944  private:
1945   ThreadStatistics *_thread_stat;
1946 
1947  public:
1948   ThreadStatistics* get_thread_stat() const    { return _thread_stat; }
1949 
1950   // Return a blocker object for which this thread is blocked parking.
1951   oop current_park_blocker();
1952 
1953  private:
1954   static size_t _stack_size_at_create;
1955 
1956  public:
1957   static inline size_t stack_size_at_create(void) {
1958     return _stack_size_at_create;
1959   }
1960   static inline void set_stack_size_at_create(size_t value) {
1961     _stack_size_at_create = value;
1962   }
1963 
1964   // Machine dependent stuff
1965 #include OS_CPU_HEADER(thread)
1966 
1967  public:
1968   void set_blocked_on_compilation(bool value) {
1969     _blocked_on_compilation = value;
1970   }
1971 
1972   bool blocked_on_compilation() {
1973     return _blocked_on_compilation;
1974   }
1975  protected:
1976   bool         _blocked_on_compilation;
1977 
1978 
1979   // JSR166 per-thread parker
1980  private:
1981   Parker*    _parker;
1982  public:
1983   Parker*     parker() { return _parker; }
1984 
1985   // Biased locking support
1986  private:
1987   GrowableArray<MonitorInfo*>* _cached_monitor_info;
1988  public:
1989   GrowableArray<MonitorInfo*>* cached_monitor_info() { return _cached_monitor_info; }
1990   void set_cached_monitor_info(GrowableArray<MonitorInfo*>* info) { _cached_monitor_info = info; }
1991 
1992   // clearing/querying jni attach status
1993   bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; }
1994   bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
1995   inline void set_done_attaching_via_jni();
1996 };
1997 
1998 // Inline implementation of JavaThread::current
1999 inline JavaThread* JavaThread::current() {
2000   Thread* thread = Thread::current();
2001   assert(thread->is_Java_thread(), "just checking");
2002   return (JavaThread*)thread;
2003 }
2004 
2005 inline CompilerThread* JavaThread::as_CompilerThread() {
2006   assert(is_Compiler_thread(), "just checking");
2007   return (CompilerThread*)this;
2008 }
2009 
2010 // Dedicated thread to sweep the code cache
2011 class CodeCacheSweeperThread : public JavaThread {
2012   CompiledMethod*       _scanned_compiled_method; // nmethod being scanned by the sweeper
2013  public:
2014   CodeCacheSweeperThread();
2015   // Track the nmethod currently being scanned by the sweeper
2016   void set_scanned_compiled_method(CompiledMethod* cm) {
2017     assert(_scanned_compiled_method == NULL || cm == NULL, "should reset to NULL before writing a new value");
2018     _scanned_compiled_method = cm;
2019   }
2020 
2021   // Hide sweeper thread from external view.
2022   bool is_hidden_from_external_view() const { return true; }
2023 
2024   bool is_Code_cache_sweeper_thread() const { return true; }
2025 
2026   // Prevent GC from unloading _scanned_compiled_method
2027   void oops_do(OopClosure* f, CodeBlobClosure* cf);
2028   void nmethods_do(CodeBlobClosure* cf);
2029 };
2030 
2031 // A thread used for Compilation.
2032 class CompilerThread : public JavaThread {
2033   friend class VMStructs;
2034  private:
2035   CompilerCounters* _counters;
2036 
2037   ciEnv*                _env;
2038   CompileLog*           _log;
2039   CompileTask* volatile _task;  // print_threads_compiling can read this concurrently.
2040   CompileQueue*         _queue;
2041   BufferBlob*           _buffer_blob;
2042 
2043   AbstractCompiler*     _compiler;
2044   TimeStamp             _idle_time;
2045 
2046  public:
2047 
2048   static CompilerThread* current();
2049 
2050   CompilerThread(CompileQueue* queue, CompilerCounters* counters);
2051   ~CompilerThread();
2052 
2053   bool is_Compiler_thread() const                { return true; }
2054 
2055   virtual bool can_call_java() const;
2056 
2057   // Hide native compiler threads from external view.
2058   bool is_hidden_from_external_view() const      { return !can_call_java(); }
2059 
2060   void set_compiler(AbstractCompiler* c)         { _compiler = c; }
2061   AbstractCompiler* compiler() const             { return _compiler; }
2062 
2063   CompileQueue* queue()        const             { return _queue; }
2064   CompilerCounters* counters() const             { return _counters; }
2065 
2066   // Get/set the thread's compilation environment.
2067   ciEnv*        env()                            { return _env; }
2068   void          set_env(ciEnv* env)              { _env = env; }
2069 
2070   BufferBlob*   get_buffer_blob() const          { return _buffer_blob; }
2071   void          set_buffer_blob(BufferBlob* b)   { _buffer_blob = b; }
2072 
2073   // Get/set the thread's logging information
2074   CompileLog*   log()                            { return _log; }
2075   void          init_log(CompileLog* log) {
2076     // Set once, for good.
2077     assert(_log == NULL, "set only once");
2078     _log = log;
2079   }
2080 
2081   void start_idle_timer()                        { _idle_time.update(); }
2082   jlong idle_time_millis() {
2083     return TimeHelper::counter_to_millis(_idle_time.ticks_since_update());
2084   }
2085 
2086 #ifndef PRODUCT
2087  private:
2088   IdealGraphPrinter *_ideal_graph_printer;
2089  public:
2090   IdealGraphPrinter *ideal_graph_printer()           { return _ideal_graph_printer; }
2091   void set_ideal_graph_printer(IdealGraphPrinter *n) { _ideal_graph_printer = n; }
2092 #endif
2093 
2094   // Get/set the thread's current task
2095   CompileTask* task()                      { return _task; }
2096   void         set_task(CompileTask* task) { _task = task; }
2097 };
2098 
2099 inline CompilerThread* CompilerThread::current() {
2100   return JavaThread::current()->as_CompilerThread();
2101 }
2102 
2103 // The active thread queue. It also keeps track of the current used
2104 // thread priorities.
2105 class Threads: AllStatic {
2106   friend class VMStructs;
2107  private:
2108   static JavaThread* _thread_list;
2109   static int         _number_of_threads;
2110   static int         _number_of_non_daemon_threads;
2111   static int         _return_code;
2112   static int         _thread_claim_parity;
2113 #ifdef ASSERT
2114   static bool        _vm_complete;
2115 #endif
2116 
2117   static void initialize_java_lang_classes(JavaThread* main_thread, TRAPS);
2118   static void initialize_jsr292_core_classes(TRAPS);
2119 
2120  public:
2121   // Thread management
2122   // force_daemon is a concession to JNI, where we may need to add a
2123   // thread to the thread list before allocating its thread object
2124   static void add(JavaThread* p, bool force_daemon = false);
2125   static void remove(JavaThread* p);
2126   static void non_java_threads_do(ThreadClosure* tc);
2127   static void java_threads_do(ThreadClosure* tc);
2128   static void java_threads_and_vm_thread_do(ThreadClosure* tc);
2129   static void threads_do(ThreadClosure* tc);
2130   static void possibly_parallel_threads_do(bool is_par, ThreadClosure* tc);
2131 
2132   // Initializes the vm and creates the vm thread
2133   static jint create_vm(JavaVMInitArgs* args, bool* canTryAgain);
2134   static void convert_vm_init_libraries_to_agents();
2135   static void create_vm_init_libraries();
2136   static void create_vm_init_agents();
2137   static void shutdown_vm_agents();
2138   static bool destroy_vm();
2139   // Supported VM versions via JNI
2140   // Includes JNI_VERSION_1_1
2141   static jboolean is_supported_jni_version_including_1_1(jint version);
2142   // Does not include JNI_VERSION_1_1
2143   static jboolean is_supported_jni_version(jint version);
2144 
2145   // The "thread claim parity" provides a way for threads to be claimed
2146   // by parallel worker tasks.
2147   //
2148   // Each thread contains a a "parity" field. A task will claim the
2149   // thread only if its parity field is the same as the global parity,
2150   // which is updated by calling change_thread_claim_parity().
2151   //
2152   // For this to work change_thread_claim_parity() needs to be called
2153   // exactly once in sequential code before starting parallel tasks
2154   // that should claim threads.
2155   //
2156   // New threads get their parity set to 0 and change_thread_claim_parity()
2157   // never set the global parity to 0.
2158   static int thread_claim_parity() { return _thread_claim_parity; }
2159   static void change_thread_claim_parity();
2160   static void assert_all_threads_claimed() NOT_DEBUG_RETURN;
2161 
2162   // Apply "f->do_oop" to all root oops in all threads.
2163   // This version may only be called by sequential code.
2164   static void oops_do(OopClosure* f, CodeBlobClosure* cf);
2165   // This version may be called by sequential or parallel code.
2166   static void possibly_parallel_oops_do(bool is_par, OopClosure* f, CodeBlobClosure* cf);
2167 
2168   // Apply "f->do_oop" to roots in all threads that
2169   // are part of compiled frames
2170   static void compiled_frame_oops_do(OopClosure* f, CodeBlobClosure* cf);
2171 
2172   static void convert_hcode_pointers();
2173   static void restore_hcode_pointers();
2174 
2175   // Sweeper
2176   static void nmethods_do(CodeBlobClosure* cf);
2177 
2178   // RedefineClasses support
2179   static void metadata_do(void f(Metadata*));
2180   static void metadata_handles_do(void f(Metadata*));
2181 
2182 #ifdef ASSERT
2183   static bool is_vm_complete() { return _vm_complete; }
2184 #endif
2185 
2186   // Verification
2187   static void verify();
2188   static void print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks, bool print_extended_info);
2189   static void print(bool print_stacks, bool internal_format) {
2190     // this function is only used by debug.cpp
2191     print_on(tty, print_stacks, internal_format, false /* no concurrent lock printed */, false /* simple format */);
2192   }
2193   static void print_on_error(outputStream* st, Thread* current, char* buf, int buflen);
2194   static void print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
2195                              int buflen, bool* found_current);
2196   static void print_threads_compiling(outputStream* st, char* buf, int buflen);
2197 
2198   // Get Java threads that are waiting to enter a monitor.
2199   static GrowableArray<JavaThread*>* get_pending_threads(ThreadsList * t_list,
2200                                                          int count, address monitor);
2201 
2202   // Get owning Java thread from the monitor's owner field.
2203   static JavaThread *owning_thread_from_monitor_owner(ThreadsList * t_list,
2204                                                       address owner);
2205 
2206   // Number of threads on the active threads list
2207   static int number_of_threads()                 { return _number_of_threads; }
2208   // Number of non-daemon threads on the active threads list
2209   static int number_of_non_daemon_threads()      { return _number_of_non_daemon_threads; }
2210 
2211   // Deoptimizes all frames tied to marked nmethods
2212   static void deoptimized_wrt_marked_nmethods();
2213 };
2214 
2215 
2216 // Thread iterator
2217 class ThreadClosure: public StackObj {
2218  public:
2219   virtual void do_thread(Thread* thread) = 0;
2220 };
2221 
2222 class SignalHandlerMark: public StackObj {
2223  private:
2224   Thread* _thread;
2225  public:
2226   SignalHandlerMark(Thread* t) {
2227     _thread = t;
2228     if (_thread) _thread->enter_signal_handler();
2229   }
2230   ~SignalHandlerMark() {
2231     if (_thread) _thread->leave_signal_handler();
2232     _thread = NULL;
2233   }
2234 };
2235 
2236 
2237 #endif // SHARE_VM_RUNTIME_THREAD_HPP