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 "code/compiledMethod.hpp"
  30 #include "gc/shared/gcThreadLocalData.hpp"
  31 #include "gc/shared/threadLocalAllocBuffer.hpp"
  32 #include "memory/allocation.hpp"
  33 #include "oops/oop.hpp"
  34 #include "prims/jvmtiExport.hpp"
  35 #include "runtime/frame.hpp"
  36 #include "runtime/globals.hpp"
  37 #include "runtime/handshake.hpp"
  38 #include "runtime/javaFrameAnchor.hpp"
  39 #include "runtime/jniHandles.hpp"
  40 #include "runtime/mutexLocker.hpp"
  41 #include "runtime/os.hpp"
  42 #include "runtime/osThread.hpp"
  43 #include "runtime/park.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 
  60 class SafeThreadsListPtr;
  61 class ThreadSafepointState;
  62 class ThreadsList;
  63 class ThreadsSMRSupport;
  64 
  65 class JvmtiThreadState;
  66 class ThreadStatistics;
  67 class ConcurrentLocksDump;
  68 class ParkEvent;
  69 class Parker;
  70 
  71 class ciEnv;
  72 class CompileThread;
  73 class CompileLog;
  74 class CompileTask;
  75 class CompileQueue;
  76 class CompilerCounters;
  77 class vframeArray;
  78 
  79 class DeoptResourceMark;
  80 class jvmtiDeferredLocalVariableSet;
  81 
  82 class GCTaskQueue;
  83 class ThreadClosure;
  84 class IdealGraphPrinter;
  85 
  86 class Metadata;
  87 template <class T, MEMFLAGS F> class ChunkedList;
  88 typedef ChunkedList<Metadata*, mtInternal> MetadataOnStackBuffer;
  89 
  90 DEBUG_ONLY(class ResourceMark;)
  91 
  92 class WorkerThread;
  93 
  94 // Class hierarchy
  95 // - Thread
  96 //   - JavaThread
  97 //     - various subclasses eg CompilerThread, ServiceThread
  98 //   - NonJavaThread
  99 //     - NamedThread
 100 //       - VMThread
 101 //       - ConcurrentGCThread
 102 //       - WorkerThread
 103 //         - GangWorker
 104 //         - GCTaskThread
 105 //     - WatcherThread
 106 //     - JfrThreadSampler
 107 //
 108 // All Thread subclasses must be either JavaThread or NonJavaThread.
 109 // This means !t->is_Java_thread() iff t is a NonJavaThread, or t is
 110 // a partially constructed/destroyed Thread.
 111 
 112 /*
 113   Thread execution sequence and actions:
 114 
 115   All threads:
 116    - thread_native_entry  // per-OS native entry point
 117      - stack initialization
 118      - other OS-level initialization (signal masks etc)
 119      - handshake with creating thread (if not started suspended)
 120      - this->call_run()  // common shared entry point
 121        - shared common initialization
 122        - this->pre_run()  // virtual per-thread-type initialization
 123        - this->run()      // virtual per-thread-type "main" logic
 124        - shared common tear-down
 125        - this->post_run()  // virtual per-thread-type tear-down
 126        - // 'this' no longer referenceable
 127      - OS-level tear-down (minimal)
 128      - final logging
 129 
 130   For JavaThread:
 131     - this->run()  // virtual but not normally overridden
 132       - this->thread_main_inner()  // extra call level to ensure correct stack calculations
 133         - this->entry_point()  // set differently for each kind of JavaThread
 134 
 135 */
 136 
 137 class Thread: public ThreadShadow {
 138   friend class VMStructs;
 139   friend class JVMCIVMStructs;
 140  private:
 141 
 142 #ifndef USE_LIBRARY_BASED_TLS_ONLY
 143   // Current thread is maintained as a thread-local variable
 144   static THREAD_LOCAL_DECL Thread* _thr_current;
 145 #endif
 146 
 147   // Thread local data area available to the GC. The internal
 148   // structure and contents of this data area is GC-specific.
 149   // Only GC and GC barrier code should access this data area.
 150   GCThreadLocalData _gc_data;
 151 
 152  public:
 153   static ByteSize gc_data_offset() {
 154     return byte_offset_of(Thread, _gc_data);
 155   }
 156 
 157   template <typename T> T* gc_data() {
 158     STATIC_ASSERT(sizeof(T) <= sizeof(_gc_data));
 159     return reinterpret_cast<T*>(&_gc_data);
 160   }
 161 
 162   // Exception handling
 163   // (Note: _pending_exception and friends are in ThreadShadow)
 164   //oop       _pending_exception;                // pending exception for current thread
 165   // const char* _exception_file;                   // file information for exception (debugging only)
 166   // int         _exception_line;                   // line information for exception (debugging only)
 167  protected:
 168 
 169   DEBUG_ONLY(static Thread* _starting_thread;)
 170 
 171   // Support for forcing alignment of thread objects for biased locking
 172   void*       _real_malloc_address;
 173 
 174   // JavaThread lifecycle support:
 175   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
 176   friend class ScanHazardPtrGatherProtectedThreadsClosure;  // for cmpxchg_threads_hazard_ptr(), get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
 177   friend class ScanHazardPtrGatherThreadsListClosure;  // for get_threads_hazard_ptr(), untag_hazard_ptr() access
 178   friend class ScanHazardPtrPrintMatchingThreadsClosure;  // for get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
 179   friend class ThreadsSMRSupport;  // for _nested_threads_hazard_ptr_cnt, _threads_hazard_ptr, _threads_list_ptr access
 180 
 181   ThreadsList* volatile _threads_hazard_ptr;
 182   SafeThreadsListPtr*   _threads_list_ptr;
 183   ThreadsList*          cmpxchg_threads_hazard_ptr(ThreadsList* exchange_value, ThreadsList* compare_value);
 184   ThreadsList*          get_threads_hazard_ptr();
 185   void                  set_threads_hazard_ptr(ThreadsList* new_list);
 186   static bool           is_hazard_ptr_tagged(ThreadsList* list) {
 187     return (intptr_t(list) & intptr_t(1)) == intptr_t(1);
 188   }
 189   static ThreadsList*   tag_hazard_ptr(ThreadsList* list) {
 190     return (ThreadsList*)(intptr_t(list) | intptr_t(1));
 191   }
 192   static ThreadsList*   untag_hazard_ptr(ThreadsList* list) {
 193     return (ThreadsList*)(intptr_t(list) & ~intptr_t(1));
 194   }
 195   // This field is enabled via -XX:+EnableThreadSMRStatistics:
 196   uint _nested_threads_hazard_ptr_cnt;
 197   void dec_nested_threads_hazard_ptr_cnt() {
 198     assert(_nested_threads_hazard_ptr_cnt != 0, "mismatched {dec,inc}_nested_threads_hazard_ptr_cnt()");
 199     _nested_threads_hazard_ptr_cnt--;
 200   }
 201   void inc_nested_threads_hazard_ptr_cnt() {
 202     _nested_threads_hazard_ptr_cnt++;
 203   }
 204   uint nested_threads_hazard_ptr_cnt() {
 205     return _nested_threads_hazard_ptr_cnt;
 206   }
 207 
 208  public:
 209   void* operator new(size_t size) throw() { return allocate(size, true); }
 210   void* operator new(size_t size, const std::nothrow_t& nothrow_constant) throw() {
 211     return allocate(size, false); }
 212   void  operator delete(void* p);
 213 
 214  protected:
 215   static void* allocate(size_t size, bool throw_excpt, MEMFLAGS flags = mtThread);
 216  private:
 217 
 218   // ***************************************************************
 219   // Suspend and resume support
 220   // ***************************************************************
 221   //
 222   // VM suspend/resume no longer exists - it was once used for various
 223   // things including safepoints but was deprecated and finally removed
 224   // in Java 7. Because VM suspension was considered "internal" Java-level
 225   // suspension was considered "external", and this legacy naming scheme
 226   // remains.
 227   //
 228   // External suspend/resume requests come from JVM_SuspendThread,
 229   // JVM_ResumeThread, JVMTI SuspendThread, and finally JVMTI
 230   // ResumeThread. External
 231   // suspend requests cause _external_suspend to be set and external
 232   // resume requests cause _external_suspend to be cleared.
 233   // External suspend requests do not nest on top of other external
 234   // suspend requests. The higher level APIs reject suspend requests
 235   // for already suspended threads.
 236   //
 237   // The external_suspend
 238   // flag is checked by has_special_runtime_exit_condition() and java thread
 239   // will self-suspend when handle_special_runtime_exit_condition() is
 240   // called. Most uses of the _thread_blocked state in JavaThreads are
 241   // considered the same as being externally suspended; if the blocking
 242   // condition lifts, the JavaThread will self-suspend. Other places
 243   // where VM checks for external_suspend include:
 244   //   + mutex granting (do not enter monitors when thread is suspended)
 245   //   + state transitions from _thread_in_native
 246   //
 247   // In general, java_suspend() does not wait for an external suspend
 248   // request to complete. When it returns, the only guarantee is that
 249   // the _external_suspend field is true.
 250   //
 251   // wait_for_ext_suspend_completion() is used to wait for an external
 252   // suspend request to complete. External suspend requests are usually
 253   // followed by some other interface call that requires the thread to
 254   // be quiescent, e.g., GetCallTrace(). By moving the "wait time" into
 255   // the interface that requires quiescence, we give the JavaThread a
 256   // chance to self-suspend before we need it to be quiescent. This
 257   // improves overall suspend/query performance.
 258   //
 259   // _suspend_flags controls the behavior of java_ suspend/resume.
 260   // It must be set under the protection of SR_lock. Read from the flag is
 261   // OK without SR_lock as long as the value is only used as a hint.
 262   // (e.g., check _external_suspend first without lock and then recheck
 263   // inside SR_lock and finish the suspension)
 264   //
 265   // _suspend_flags is also overloaded for other "special conditions" so
 266   // that a single check indicates whether any special action is needed
 267   // eg. for async exceptions.
 268   // -------------------------------------------------------------------
 269   // Notes:
 270   // 1. The suspend/resume logic no longer uses ThreadState in OSThread
 271   // but we still update its value to keep other part of the system (mainly
 272   // JVMTI) happy. ThreadState is legacy code (see notes in
 273   // osThread.hpp).
 274   //
 275   // 2. It would be more natural if set_external_suspend() is private and
 276   // part of java_suspend(), but that probably would affect the suspend/query
 277   // performance. Need more investigation on this.
 278 
 279   // suspend/resume lock: used for self-suspend
 280   Monitor* _SR_lock;
 281 
 282  protected:
 283   enum SuspendFlags {
 284     // NOTE: avoid using the sign-bit as cc generates different test code
 285     //       when the sign-bit is used, and sometimes incorrectly - see CR 6398077
 286 
 287     _external_suspend       = 0x20000000U, // thread is asked to self suspend
 288     _ext_suspended          = 0x40000000U, // thread has self-suspended
 289     _deopt_suspend          = 0x10000000U, // thread needs to self suspend for deopt
 290 
 291     _has_async_exception    = 0x00000001U, // there is a pending async exception
 292     _critical_native_unlock = 0x00000002U, // Must call back to unlock JNI critical lock
 293 
 294     _trace_flag             = 0x00000004U  // call tracing backend
 295   };
 296 
 297   // various suspension related flags - atomically updated
 298   // overloaded for async exception checking in check_special_condition_for_native_trans.
 299   volatile uint32_t _suspend_flags;
 300 
 301  private:
 302   int _num_nested_signal;
 303 
 304   DEBUG_ONLY(bool _suspendible_thread;)
 305 
 306  public:
 307   void enter_signal_handler() { _num_nested_signal++; }
 308   void leave_signal_handler() { _num_nested_signal--; }
 309   bool is_inside_signal_handler() const { return _num_nested_signal > 0; }
 310 
 311   // Determines if a heap allocation failure will be retried
 312   // (e.g., by deoptimizing and re-executing in the interpreter).
 313   // In this case, the failed allocation must raise
 314   // Universe::out_of_memory_error_retry() and omit side effects
 315   // such as JVMTI events and handling -XX:+HeapDumpOnOutOfMemoryError
 316   // and -XX:OnOutOfMemoryError.
 317   virtual bool in_retryable_allocation() const { return false; }
 318 
 319 #ifdef ASSERT
 320   void set_suspendible_thread() {
 321     _suspendible_thread = true;
 322   }
 323 
 324   void clear_suspendible_thread() {
 325     _suspendible_thread = false;
 326   }
 327 
 328   bool is_suspendible_thread() { return _suspendible_thread; }
 329 #endif
 330 
 331  private:
 332   // Active_handles points to a block of handles
 333   JNIHandleBlock* _active_handles;
 334 
 335   // One-element thread local free list
 336   JNIHandleBlock* _free_handle_block;
 337 
 338   // Point to the last handle mark
 339   HandleMark* _last_handle_mark;
 340 
 341   // The parity of the last strong_roots iteration in which this thread was
 342   // claimed as a task.
 343   int _oops_do_parity;
 344 
 345   // Support for GlobalCounter
 346  private:
 347   volatile uintx _rcu_counter;
 348  public:
 349   volatile uintx* get_rcu_counter() {
 350     return &_rcu_counter;
 351   }
 352 
 353  public:
 354   void set_last_handle_mark(HandleMark* mark)   { _last_handle_mark = mark; }
 355   HandleMark* last_handle_mark() const          { return _last_handle_mark; }
 356  private:
 357 
 358 #ifdef ASSERT
 359   void* _missed_ic_stub_refill_mark;
 360 
 361  public:
 362   void* missed_ic_stub_refill_mark() {
 363     return _missed_ic_stub_refill_mark;
 364   }
 365 
 366   void set_missed_ic_stub_refill_mark(void* mark) {
 367     _missed_ic_stub_refill_mark = mark;
 368   }
 369 #endif
 370 
 371  private:
 372 
 373   // debug support for checking if code does allow safepoints or not
 374   // GC points in the VM can happen because of allocation, invoking a VM operation, or blocking on
 375   // mutex, or blocking on an object synchronizer (Java locking).
 376   // If !allow_safepoint(), then an assertion failure will happen in any of the above cases
 377   // If !allow_allocation(), then an assertion failure will happen during allocation
 378   // (Hence, !allow_safepoint() => !allow_allocation()).
 379   //
 380   // The two classes NoSafepointVerifier and No_Allocation_Verifier are used to set these counters.
 381   //
 382   NOT_PRODUCT(int _allow_safepoint_count;)      // If 0, thread allow a safepoint to happen
 383   debug_only(int _allow_allocation_count;)     // If 0, the thread is allowed to allocate oops.
 384 
 385   // Used by SkipGCALot class.
 386   NOT_PRODUCT(bool _skip_gcalot;)               // Should we elide gc-a-lot?
 387 
 388   friend class NoAllocVerifier;
 389   friend class NoSafepointVerifier;
 390   friend class PauseNoSafepointVerifier;
 391   friend class GCLocker;
 392 
 393   volatile void* _polling_page;                 // Thread local polling page
 394 
 395   ThreadLocalAllocBuffer _tlab;                 // Thread-local eden
 396   jlong _allocated_bytes;                       // Cumulative number of bytes allocated on
 397                                                 // the Java heap
 398   ThreadHeapSampler _heap_sampler;              // For use when sampling the memory.
 399 
 400   ThreadStatisticalInfo _statistical_info;      // Statistics about the thread
 401 
 402   JFR_ONLY(DEFINE_THREAD_LOCAL_FIELD_JFR;)      // Thread-local data for jfr
 403 
 404   int   _vm_operation_started_count;            // VM_Operation support
 405   int   _vm_operation_completed_count;          // VM_Operation support
 406 
 407   ObjectMonitor* _current_pending_monitor;      // ObjectMonitor this thread
 408                                                 // is waiting to lock
 409   bool _current_pending_monitor_is_from_java;   // locking is from Java code
 410 
 411   // ObjectMonitor on which this thread called Object.wait()
 412   ObjectMonitor* _current_waiting_monitor;
 413 
 414   // Private thread-local objectmonitor list - a simple cache organized as a SLL.
 415  public:
 416   ObjectMonitor* omFreeList;
 417   int omFreeCount;                              // length of omFreeList
 418   int omFreeProvision;                          // reload chunk size
 419   ObjectMonitor* omInUseList;                   // SLL to track monitors in circulation
 420   int omInUseCount;                             // length of omInUseList
 421 
 422 #ifdef ASSERT
 423  private:
 424   bool _visited_for_critical_count;
 425 
 426  public:
 427   void set_visited_for_critical_count(bool z) { _visited_for_critical_count = z; }
 428   bool was_visited_for_critical_count() const   { return _visited_for_critical_count; }
 429 #endif
 430 
 431  public:
 432   enum {
 433     is_definitely_current_thread = true
 434   };
 435 
 436   // Constructor
 437   Thread();
 438   virtual ~Thread() = 0;        // Thread is abstract.
 439 
 440   // Manage Thread::current()
 441   void initialize_thread_current();
 442   static void clear_thread_current(); // TLS cleanup needed before threads terminate
 443 
 444  protected:
 445   // To be implemented by children.
 446   virtual void run() = 0;
 447   virtual void pre_run() = 0;
 448   virtual void post_run() = 0;  // Note: Thread must not be deleted prior to calling this!
 449 
 450 #ifdef ASSERT
 451   enum RunState {
 452     PRE_CALL_RUN,
 453     CALL_RUN,
 454     PRE_RUN,
 455     RUN,
 456     POST_RUN
 457     // POST_CALL_RUN - can't define this one as 'this' may be deleted when we want to set it
 458   };
 459   RunState _run_state;  // for lifecycle checks
 460 #endif
 461 
 462 
 463  public:
 464   // invokes <ChildThreadClass>::run(), with common preparations and cleanups.
 465   void call_run();
 466 
 467   // Testers
 468   virtual bool is_VM_thread()       const            { return false; }
 469   virtual bool is_Java_thread()     const            { return false; }
 470   virtual bool is_Compiler_thread() const            { return false; }
 471   virtual bool is_Code_cache_sweeper_thread() const  { return false; }
 472   virtual bool is_hidden_from_external_view() const  { return false; }
 473   virtual bool is_jvmti_agent_thread() const         { return false; }
 474   // True iff the thread can perform GC operations at a safepoint.
 475   // Generally will be true only of VM thread and parallel GC WorkGang
 476   // threads.
 477   virtual bool is_GC_task_thread() const             { return false; }
 478   virtual bool is_Watcher_thread() const             { return false; }
 479   virtual bool is_ConcurrentGC_thread() const        { return false; }
 480   virtual bool is_Named_thread() const               { return false; }
 481   virtual bool is_Worker_thread() const              { return false; }
 482 
 483   // Can this thread make Java upcalls
 484   virtual bool can_call_java() const                 { return false; }
 485 
 486   // Casts
 487   virtual WorkerThread* as_Worker_thread() const     { return NULL; }
 488 
 489   virtual char* name() const { return (char*)"Unknown thread"; }
 490 
 491   // Returns the current thread (ASSERTS if NULL)
 492   static inline Thread* current();
 493   // Returns the current thread, or NULL if not attached
 494   static inline Thread* current_or_null();
 495   // Returns the current thread, or NULL if not attached, and is
 496   // safe for use from signal-handlers
 497   static inline Thread* current_or_null_safe();
 498 
 499   // Common thread operations
 500 #ifdef ASSERT
 501   static void check_for_dangling_thread_pointer(Thread *thread);
 502 #endif
 503   static void set_priority(Thread* thread, ThreadPriority priority);
 504   static ThreadPriority get_priority(const Thread* const thread);
 505   static void start(Thread* thread);
 506   static void interrupt(Thread* thr);
 507   static bool is_interrupted(Thread* thr, bool clear_interrupted);
 508 
 509   void set_native_thread_name(const char *name) {
 510     assert(Thread::current() == this, "set_native_thread_name can only be called on the current thread");
 511     os::set_native_thread_name(name);
 512   }
 513 
 514   ObjectMonitor** omInUseList_addr()             { return (ObjectMonitor **)&omInUseList; }
 515   Monitor* SR_lock() const                       { return _SR_lock; }
 516 
 517   bool has_async_exception() const { return (_suspend_flags & _has_async_exception) != 0; }
 518 
 519   inline void set_suspend_flag(SuspendFlags f);
 520   inline void clear_suspend_flag(SuspendFlags f);
 521 
 522   inline void set_has_async_exception();
 523   inline void clear_has_async_exception();
 524 
 525   bool do_critical_native_unlock() const { return (_suspend_flags & _critical_native_unlock) != 0; }
 526 
 527   inline void set_critical_native_unlock();
 528   inline void clear_critical_native_unlock();
 529 
 530   inline void set_trace_flag();
 531   inline void clear_trace_flag();
 532 
 533   // Support for Unhandled Oop detection
 534   // Add the field for both, fastdebug and debug, builds to keep
 535   // Thread's fields layout the same.
 536   // Note: CHECK_UNHANDLED_OOPS is defined only for fastdebug build.
 537 #ifdef CHECK_UNHANDLED_OOPS
 538  private:
 539   UnhandledOops* _unhandled_oops;
 540 #elif defined(ASSERT)
 541  private:
 542   void* _unhandled_oops;
 543 #endif
 544 #ifdef CHECK_UNHANDLED_OOPS
 545  public:
 546   UnhandledOops* unhandled_oops() { return _unhandled_oops; }
 547   // Mark oop safe for gc.  It may be stack allocated but won't move.
 548   void allow_unhandled_oop(oop *op) {
 549     if (CheckUnhandledOops) unhandled_oops()->allow_unhandled_oop(op);
 550   }
 551   // Clear oops at safepoint so crashes point to unhandled oop violator
 552   void clear_unhandled_oops() {
 553     if (CheckUnhandledOops) unhandled_oops()->clear_unhandled_oops();
 554   }
 555 #endif // CHECK_UNHANDLED_OOPS
 556 
 557  public:
 558 #ifndef PRODUCT
 559   bool skip_gcalot()           { return _skip_gcalot; }
 560   void set_skip_gcalot(bool v) { _skip_gcalot = v;    }
 561 #endif
 562 
 563   // Installs a pending exception to be inserted later
 564   static void send_async_exception(oop thread_oop, oop java_throwable);
 565 
 566   // Resource area
 567   ResourceArea* resource_area() const            { return _resource_area; }
 568   void set_resource_area(ResourceArea* area)     { _resource_area = area; }
 569 
 570   OSThread* osthread() const                     { return _osthread;   }
 571   void set_osthread(OSThread* thread)            { _osthread = thread; }
 572 
 573   // JNI handle support
 574   JNIHandleBlock* active_handles() const         { return _active_handles; }
 575   void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
 576   JNIHandleBlock* free_handle_block() const      { return _free_handle_block; }
 577   void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
 578 
 579   // Internal handle support
 580   HandleArea* handle_area() const                { return _handle_area; }
 581   void set_handle_area(HandleArea* area)         { _handle_area = area; }
 582 
 583   GrowableArray<Metadata*>* metadata_handles() const          { return _metadata_handles; }
 584   void set_metadata_handles(GrowableArray<Metadata*>* handles){ _metadata_handles = handles; }
 585 
 586   // Thread-Local Allocation Buffer (TLAB) support
 587   ThreadLocalAllocBuffer& tlab()                 { return _tlab; }
 588   void initialize_tlab() {
 589     if (UseTLAB) {
 590       tlab().initialize();
 591     }
 592   }
 593 
 594   jlong allocated_bytes()               { return _allocated_bytes; }
 595   void set_allocated_bytes(jlong value) { _allocated_bytes = value; }
 596   void incr_allocated_bytes(jlong size) { _allocated_bytes += size; }
 597   inline jlong cooked_allocated_bytes();
 598 
 599   ThreadHeapSampler& heap_sampler()     { return _heap_sampler; }
 600 
 601   ThreadStatisticalInfo& statistical_info() { return _statistical_info; }
 602 
 603   JFR_ONLY(DEFINE_THREAD_LOCAL_ACCESSOR_JFR;)
 604 
 605   bool is_trace_suspend()               { return (_suspend_flags & _trace_flag) != 0; }
 606 
 607   // VM operation support
 608   int vm_operation_ticket()                      { return ++_vm_operation_started_count; }
 609   int vm_operation_completed_count()             { return _vm_operation_completed_count; }
 610   void increment_vm_operation_completed_count()  { _vm_operation_completed_count++; }
 611 
 612   // For tracking the heavyweight monitor the thread is pending on.
 613   ObjectMonitor* current_pending_monitor() {
 614     return _current_pending_monitor;
 615   }
 616   void set_current_pending_monitor(ObjectMonitor* monitor) {
 617     _current_pending_monitor = monitor;
 618   }
 619   void set_current_pending_monitor_is_from_java(bool from_java) {
 620     _current_pending_monitor_is_from_java = from_java;
 621   }
 622   bool current_pending_monitor_is_from_java() {
 623     return _current_pending_monitor_is_from_java;
 624   }
 625 
 626   // For tracking the ObjectMonitor on which this thread called Object.wait()
 627   ObjectMonitor* current_waiting_monitor() {
 628     return _current_waiting_monitor;
 629   }
 630   void set_current_waiting_monitor(ObjectMonitor* monitor) {
 631     _current_waiting_monitor = monitor;
 632   }
 633 
 634   // GC support
 635   // Apply "f->do_oop" to all root oops in "this".
 636   //   Used by JavaThread::oops_do.
 637   // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames
 638   virtual void oops_do(OopClosure* f, CodeBlobClosure* cf);
 639 
 640   // Handles the parallel case for the method below.
 641  private:
 642   bool claim_oops_do_par_case(int collection_parity);
 643  public:
 644   // Requires that "collection_parity" is that of the current roots
 645   // iteration.  If "is_par" is false, sets the parity of "this" to
 646   // "collection_parity", and returns "true".  If "is_par" is true,
 647   // uses an atomic instruction to set the current threads parity to
 648   // "collection_parity", if it is not already.  Returns "true" iff the
 649   // calling thread does the update, this indicates that the calling thread
 650   // has claimed the thread's stack as a root groop in the current
 651   // collection.
 652   bool claim_oops_do(bool is_par, int collection_parity) {
 653     if (!is_par) {
 654       _oops_do_parity = collection_parity;
 655       return true;
 656     } else {
 657       return claim_oops_do_par_case(collection_parity);
 658     }
 659   }
 660 
 661   // jvmtiRedefineClasses support
 662   void metadata_handles_do(void f(Metadata*));
 663 
 664   // Used by fast lock support
 665   virtual bool is_lock_owned(address adr) const;
 666 
 667   // Check if address is in the stack of the thread (not just for locks).
 668   // Warning: the method can only be used on the running thread
 669   bool is_in_stack(address adr) const;
 670   // Check if address is in the usable part of the stack (excludes protected
 671   // guard pages)
 672   bool is_in_usable_stack(address adr) const;
 673 
 674   // Sets this thread as starting thread. Returns failure if thread
 675   // creation fails due to lack of memory, too many threads etc.
 676   bool set_as_starting_thread();
 677 
 678 protected:
 679   // OS data associated with the thread
 680   OSThread* _osthread;  // Platform-specific thread information
 681 
 682   // Thread local resource area for temporary allocation within the VM
 683   ResourceArea* _resource_area;
 684 
 685   DEBUG_ONLY(ResourceMark* _current_resource_mark;)
 686 
 687   // Thread local handle area for allocation of handles within the VM
 688   HandleArea* _handle_area;
 689   GrowableArray<Metadata*>* _metadata_handles;
 690 
 691   // Support for stack overflow handling, get_thread, etc.
 692   address          _stack_base;
 693   size_t           _stack_size;
 694   uintptr_t        _self_raw_id;      // used by get_thread (mutable)
 695   int              _lgrp_id;
 696 
 697   volatile void** polling_page_addr() { return &_polling_page; }
 698 
 699  public:
 700   // Stack overflow support
 701   address stack_base() const           { assert(_stack_base != NULL,"Sanity check"); return _stack_base; }
 702   void    set_stack_base(address base) { _stack_base = base; }
 703   size_t  stack_size() const           { return _stack_size; }
 704   void    set_stack_size(size_t size)  { _stack_size = size; }
 705   address stack_end()  const           { return stack_base() - stack_size(); }
 706   void    record_stack_base_and_size();
 707   void    register_thread_stack_with_NMT() NOT_NMT_RETURN;
 708 
 709   bool    on_local_stack(address adr) const {
 710     // QQQ this has knowledge of direction, ought to be a stack method
 711     return (_stack_base >= adr && adr >= stack_end());
 712   }
 713 
 714   uintptr_t self_raw_id()                    { return _self_raw_id; }
 715   void      set_self_raw_id(uintptr_t value) { _self_raw_id = value; }
 716 
 717   int     lgrp_id() const        { return _lgrp_id; }
 718   void    set_lgrp_id(int value) { _lgrp_id = value; }
 719 
 720   // Printing
 721   void print_on(outputStream* st, bool print_extended_info) const;
 722   virtual void print_on(outputStream* st) const { print_on(st, false); }
 723   void print() const { print_on(tty); }
 724   virtual void print_on_error(outputStream* st, char* buf, int buflen) const;
 725   void print_value_on(outputStream* st) const;
 726 
 727   // Debug-only code
 728 #ifdef ASSERT
 729  private:
 730   // Deadlock detection support for Mutex locks. List of locks own by thread.
 731   Monitor* _owned_locks;
 732   // Mutex::set_owner_implementation is the only place where _owned_locks is modified,
 733   // thus the friendship
 734   friend class Mutex;
 735   friend class Monitor;
 736 
 737  public:
 738   void print_owned_locks_on(outputStream* st) const;
 739   void print_owned_locks() const                 { print_owned_locks_on(tty);    }
 740   Monitor* owned_locks() const                   { return _owned_locks;          }
 741   bool owns_locks() const                        { return owned_locks() != NULL; }
 742   bool owns_locks_but_compiled_lock() const;
 743   int oops_do_parity() const                     { return _oops_do_parity; }
 744 
 745   // Deadlock detection
 746   bool allow_allocation()                        { return _allow_allocation_count == 0; }
 747   ResourceMark* current_resource_mark()          { return _current_resource_mark; }
 748   void set_current_resource_mark(ResourceMark* rm) { _current_resource_mark = rm; }
 749 #endif
 750 
 751   void check_for_valid_safepoint_state(bool potential_vm_operation) PRODUCT_RETURN;
 752 
 753  private:
 754   volatile int _jvmti_env_iteration_count;
 755 
 756  public:
 757   void entering_jvmti_env_iteration()            { ++_jvmti_env_iteration_count; }
 758   void leaving_jvmti_env_iteration()             { --_jvmti_env_iteration_count; }
 759   bool is_inside_jvmti_env_iteration()           { return _jvmti_env_iteration_count > 0; }
 760 
 761   // Code generation
 762   static ByteSize exception_file_offset()        { return byte_offset_of(Thread, _exception_file); }
 763   static ByteSize exception_line_offset()        { return byte_offset_of(Thread, _exception_line); }
 764   static ByteSize active_handles_offset()        { return byte_offset_of(Thread, _active_handles); }
 765 
 766   static ByteSize stack_base_offset()            { return byte_offset_of(Thread, _stack_base); }
 767   static ByteSize stack_size_offset()            { return byte_offset_of(Thread, _stack_size); }
 768 
 769   static ByteSize polling_page_offset()          { return byte_offset_of(Thread, _polling_page); }
 770 
 771   static ByteSize tlab_start_offset()            { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::start_offset(); }
 772   static ByteSize tlab_end_offset()              { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::end_offset(); }
 773   static ByteSize tlab_top_offset()              { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::top_offset(); }
 774   static ByteSize tlab_pf_top_offset()           { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::pf_top_offset(); }
 775 
 776   static ByteSize allocated_bytes_offset()       { return byte_offset_of(Thread, _allocated_bytes); }
 777 
 778   JFR_ONLY(DEFINE_THREAD_LOCAL_OFFSET_JFR;)
 779 
 780  public:
 781   volatile intptr_t _Stalled;
 782   volatile int _TypeTag;
 783   ParkEvent * _ParkEvent;                     // for synchronized()
 784   ParkEvent * _SleepEvent;                    // for Thread.sleep
 785   ParkEvent * _MutexEvent;                    // for native internal Mutex/Monitor
 786   ParkEvent * _MuxEvent;                      // for low-level muxAcquire-muxRelease
 787   int NativeSyncRecursion;                    // diagnostic
 788 
 789   volatile int _OnTrap;                       // Resume-at IP delta
 790   jint _hashStateW;                           // Marsaglia Shift-XOR thread-local RNG
 791   jint _hashStateX;                           // thread-specific hashCode generator state
 792   jint _hashStateY;
 793   jint _hashStateZ;
 794 
 795   volatile jint rng[4];                      // RNG for spin loop
 796 
 797   // Low-level leaf-lock primitives used to implement synchronization
 798   // and native monitor-mutex infrastructure.
 799   // Not for general synchronization use.
 800   static void SpinAcquire(volatile int * Lock, const char * Name);
 801   static void SpinRelease(volatile int * Lock);
 802   static void muxAcquire(volatile intptr_t * Lock, const char * Name);
 803   static void muxAcquireW(volatile intptr_t * Lock, ParkEvent * ev);
 804   static void muxRelease(volatile intptr_t * Lock);
 805 };
 806 
 807 // Inline implementation of Thread::current()
 808 inline Thread* Thread::current() {
 809   Thread* current = current_or_null();
 810   assert(current != NULL, "Thread::current() called on detached thread");
 811   return current;
 812 }
 813 
 814 inline Thread* Thread::current_or_null() {
 815 #ifndef USE_LIBRARY_BASED_TLS_ONLY
 816   return _thr_current;
 817 #else
 818   if (ThreadLocalStorage::is_initialized()) {
 819     return ThreadLocalStorage::thread();
 820   }
 821   return NULL;
 822 #endif
 823 }
 824 
 825 inline Thread* Thread::current_or_null_safe() {
 826   if (ThreadLocalStorage::is_initialized()) {
 827     return ThreadLocalStorage::thread();
 828   }
 829   return NULL;
 830 }
 831 
 832 class NonJavaThread: public Thread {
 833   friend class VMStructs;
 834 
 835   NonJavaThread* volatile _next;
 836 
 837   class List;
 838   static List _the_list;
 839 
 840   void add_to_the_list();
 841   void remove_from_the_list();
 842 
 843  protected:
 844   virtual void pre_run();
 845   virtual void post_run();
 846 
 847  public:
 848   NonJavaThread();
 849   ~NonJavaThread();
 850 
 851   class Iterator;
 852 };
 853 
 854 // Provides iteration over the list of NonJavaThreads.
 855 // Normal list addition occurs in pre_run(), and removal occurs
 856 // in post_run(), so that only live fully-initialized threads can
 857 // be found in the list. There is a special case during VM startup
 858 // when the BarrierSet has not yet been created, where we add to the
 859 // list during the constructor. That set of initial threads (the main
 860 // thread, plus GC threads typically) is iterated over when the
 861 // BarrierSet is set and each thread is manually updated. The fact those
 862 // threads may not yet have executed is not an issue for that code.
 863 // However it is possible that those threads may still not have executed
 864 // by the time subsequent iterators are created and used - but they are
 865 // known to be fully initialized by their creating thread.
 866 // Threads created after an iterator is constructed
 867 // will not be visited by the iterator.  The scope of an iterator is a
 868 // critical section; there must be no safepoint checks in that scope.
 869 class NonJavaThread::Iterator : public StackObj {
 870   uint _protect_enter;
 871   NonJavaThread* _current;
 872 
 873   // Noncopyable.
 874   Iterator(const Iterator&);
 875   Iterator& operator=(const Iterator&);
 876 
 877 public:
 878   Iterator();
 879   ~Iterator();
 880 
 881   bool end() const { return _current == NULL; }
 882   NonJavaThread* current() const { return _current; }
 883   void step();
 884 };
 885 
 886 // Name support for threads.  non-JavaThread subclasses with multiple
 887 // uniquely named instances should derive from this.
 888 class NamedThread: public NonJavaThread {
 889   friend class VMStructs;
 890   enum {
 891     max_name_len = 64
 892   };
 893  private:
 894   char* _name;
 895   // log JavaThread being processed by oops_do
 896   JavaThread* _processed_thread;
 897   uint _gc_id; // The current GC id when a thread takes part in GC
 898 
 899  public:
 900   NamedThread();
 901   ~NamedThread();
 902   // May only be called once per thread.
 903   void set_name(const char* format, ...)  ATTRIBUTE_PRINTF(2, 3);
 904   virtual bool is_Named_thread() const { return true; }
 905   virtual char* name() const { return _name == NULL ? (char*)"Unknown Thread" : _name; }
 906   JavaThread *processed_thread() { return _processed_thread; }
 907   void set_processed_thread(JavaThread *thread) { _processed_thread = thread; }
 908   virtual void print_on(outputStream* st) const;
 909 
 910   void set_gc_id(uint gc_id) { _gc_id = gc_id; }
 911   uint gc_id() { return _gc_id; }
 912 };
 913 
 914 // Worker threads are named and have an id of an assigned work.
 915 class WorkerThread: public NamedThread {
 916  private:
 917   uint _id;
 918  public:
 919   WorkerThread() : _id(0)               { }
 920   virtual bool is_Worker_thread() const { return true; }
 921 
 922   virtual WorkerThread* as_Worker_thread() const {
 923     assert(is_Worker_thread(), "Dubious cast to WorkerThread*?");
 924     return (WorkerThread*) this;
 925   }
 926 
 927   void set_id(uint work_id)             { _id = work_id; }
 928   uint id() const                       { return _id; }
 929 };
 930 
 931 // A single WatcherThread is used for simulating timer interrupts.
 932 class WatcherThread: public NonJavaThread {
 933   friend class VMStructs;
 934  protected:
 935   virtual void run();
 936 
 937  private:
 938   static WatcherThread* _watcher_thread;
 939 
 940   static bool _startable;
 941   // volatile due to at least one lock-free read
 942   volatile static bool _should_terminate;
 943  public:
 944   enum SomeConstants {
 945     delay_interval = 10                          // interrupt delay in milliseconds
 946   };
 947 
 948   // Constructor
 949   WatcherThread();
 950 
 951   // No destruction allowed
 952   ~WatcherThread() {
 953     guarantee(false, "WatcherThread deletion must fix the race with VM termination");
 954   }
 955 
 956   // Tester
 957   bool is_Watcher_thread() const                 { return true; }
 958 
 959   // Printing
 960   char* name() const { return (char*)"VM Periodic Task Thread"; }
 961   void print_on(outputStream* st) const;
 962   void unpark();
 963 
 964   // Returns the single instance of WatcherThread
 965   static WatcherThread* watcher_thread()         { return _watcher_thread; }
 966 
 967   // Create and start the single instance of WatcherThread, or stop it on shutdown
 968   static void start();
 969   static void stop();
 970   // Only allow start once the VM is sufficiently initialized
 971   // Otherwise the first task to enroll will trigger the start
 972   static void make_startable();
 973  private:
 974   int sleep() const;
 975 };
 976 
 977 
 978 class CompilerThread;
 979 
 980 typedef void (*ThreadFunction)(JavaThread*, TRAPS);
 981 
 982 class JavaThread: public Thread {
 983   friend class VMStructs;
 984   friend class JVMCIVMStructs;
 985   friend class WhiteBox;
 986  private:
 987   JavaThread*    _next;                          // The next thread in the Threads list
 988   bool           _on_thread_list;                // Is set when this JavaThread is added to the Threads list
 989   oop            _threadObj;                     // The Java level thread object
 990 
 991 #ifdef ASSERT
 992  private:
 993   int _java_call_counter;
 994 
 995  public:
 996   int  java_call_counter()                       { return _java_call_counter; }
 997   void inc_java_call_counter()                   { _java_call_counter++; }
 998   void dec_java_call_counter() {
 999     assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
1000     _java_call_counter--;
1001   }
1002  private:  // restore original namespace restriction
1003 #endif  // ifdef ASSERT
1004 
1005 #ifndef PRODUCT
1006  public:
1007   enum {
1008     jump_ring_buffer_size = 16
1009   };
1010  private:  // restore original namespace restriction
1011 #endif
1012 
1013   JavaFrameAnchor _anchor;                       // Encapsulation of current java frame and it state
1014 
1015   ThreadFunction _entry_point;
1016 
1017   JNIEnv        _jni_environment;
1018 
1019   // Deopt support
1020   DeoptResourceMark*  _deopt_mark;               // Holds special ResourceMark for deoptimization
1021 
1022   intptr_t*      _must_deopt_id;                 // id of frame that needs to be deopted once we
1023                                                  // transition out of native
1024   CompiledMethod*       _deopt_nmethod;         // CompiledMethod that is currently being deoptimized
1025   vframeArray*  _vframe_array_head;              // Holds the heap of the active vframeArrays
1026   vframeArray*  _vframe_array_last;              // Holds last vFrameArray we popped
1027   // Because deoptimization is lazy we must save jvmti requests to set locals
1028   // in compiled frames until we deoptimize and we have an interpreter frame.
1029   // This holds the pointer to array (yeah like there might be more than one) of
1030   // description of compiled vframes that have locals that need to be updated.
1031   GrowableArray<jvmtiDeferredLocalVariableSet*>* _deferred_locals_updates;
1032 
1033   // Handshake value for fixing 6243940. We need a place for the i2c
1034   // adapter to store the callee Method*. This value is NEVER live
1035   // across a gc point so it does NOT have to be gc'd
1036   // The handshake is open ended since we can't be certain that it will
1037   // be NULLed. This is because we rarely ever see the race and end up
1038   // in handle_wrong_method which is the backend of the handshake. See
1039   // code in i2c adapters and handle_wrong_method.
1040 
1041   Method*       _callee_target;
1042 
1043   // Used to pass back results to the interpreter or generated code running Java code.
1044   oop           _vm_result;    // oop result is GC-preserved
1045   Metadata*     _vm_result_2;  // non-oop result
1046 
1047   // See ReduceInitialCardMarks: this holds the precise space interval of
1048   // the most recent slow path allocation for which compiled code has
1049   // elided card-marks for performance along the fast-path.
1050   MemRegion     _deferred_card_mark;
1051 
1052   MonitorChunk* _monitor_chunks;                 // Contains the off stack monitors
1053                                                  // allocated during deoptimization
1054                                                  // and by JNI_MonitorEnter/Exit
1055 
1056   // Async. requests support
1057   enum AsyncRequests {
1058     _no_async_condition = 0,
1059     _async_exception,
1060     _async_unsafe_access_error
1061   };
1062   AsyncRequests _special_runtime_exit_condition; // Enum indicating pending async. request
1063   oop           _pending_async_exception;
1064 
1065   // Safepoint support
1066  public:                                         // Expose _thread_state for SafeFetchInt()
1067   volatile JavaThreadState _thread_state;
1068  private:
1069   ThreadSafepointState* _safepoint_state;        // Holds information about a thread during a safepoint
1070   address               _saved_exception_pc;     // Saved pc of instruction where last implicit exception happened
1071 
1072   // JavaThread termination support
1073   enum TerminatedTypes {
1074     _not_terminated = 0xDEAD - 2,
1075     _thread_exiting,                             // JavaThread::exit() has been called for this thread
1076     _thread_terminated,                          // JavaThread is removed from thread list
1077     _vm_exited                                   // JavaThread is still executing native code, but VM is terminated
1078                                                  // only VM_Exit can set _vm_exited
1079   };
1080 
1081   // In general a JavaThread's _terminated field transitions as follows:
1082   //
1083   //   _not_terminated => _thread_exiting => _thread_terminated
1084   //
1085   // _vm_exited is a special value to cover the case of a JavaThread
1086   // executing native code after the VM itself is terminated.
1087   volatile TerminatedTypes _terminated;
1088   // suspend/resume support
1089   volatile bool         _suspend_equivalent;     // Suspend equivalent condition
1090   jint                  _in_deopt_handler;       // count of deoptimization
1091                                                  // handlers thread is in
1092   volatile bool         _doing_unsafe_access;    // Thread may fault due to unsafe access
1093   bool                  _do_not_unlock_if_synchronized;  // Do not unlock the receiver of a synchronized method (since it was
1094                                                          // never locked) when throwing an exception. Used by interpreter only.
1095 
1096   // JNI attach states:
1097   enum JNIAttachStates {
1098     _not_attaching_via_jni = 1,  // thread is not attaching via JNI
1099     _attaching_via_jni,          // thread is attaching via JNI
1100     _attached_via_jni            // thread has attached via JNI
1101   };
1102 
1103   // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
1104   // A native thread that is attaching via JNI starts with a value
1105   // of _attaching_via_jni and transitions to _attached_via_jni.
1106   volatile JNIAttachStates _jni_attach_state;
1107 
1108  public:
1109   // State of the stack guard pages for this thread.
1110   enum StackGuardState {
1111     stack_guard_unused,         // not needed
1112     stack_guard_reserved_disabled,
1113     stack_guard_yellow_reserved_disabled,// disabled (temporarily) after stack overflow
1114     stack_guard_enabled         // enabled
1115   };
1116 
1117  private:
1118 
1119 #if INCLUDE_JVMCI
1120   // The _pending_* fields below are used to communicate extra information
1121   // from an uncommon trap in JVMCI compiled code to the uncommon trap handler.
1122 
1123   // Communicates the DeoptReason and DeoptAction of the uncommon trap
1124   int       _pending_deoptimization;
1125 
1126   // Specifies whether the uncommon trap is to bci 0 of a synchronized method
1127   // before the monitor has been acquired.
1128   bool      _pending_monitorenter;
1129 
1130   // Specifies if the DeoptReason for the last uncommon trap was Reason_transfer_to_interpreter
1131   bool      _pending_transfer_to_interpreter;
1132 
1133   // Guard for re-entrant call to JVMCIRuntime::adjust_comp_level
1134   bool      _adjusting_comp_level;
1135 
1136   // True if in a runtime call from compiled code that will deoptimize
1137   // and re-execute a failed heap allocation in the interpreter.
1138   bool      _in_retryable_allocation;
1139 
1140   // An id of a speculation that JVMCI compiled code can use to further describe and
1141   // uniquely identify the  speculative optimization guarded by the uncommon trap
1142   long       _pending_failed_speculation;
1143 
1144   // These fields are mutually exclusive in terms of live ranges.
1145   union {
1146     // Communicates the pc at which the most recent implicit exception occurred
1147     // from the signal handler to a deoptimization stub.
1148     address   _implicit_exception_pc;
1149 
1150     // Communicates an alternative call target to an i2c stub from a JavaCall .
1151     address   _alternate_call_target;
1152   } _jvmci;
1153 
1154   // Support for high precision, thread sensitive counters in JVMCI compiled code.
1155   jlong*    _jvmci_counters;
1156 
1157  public:
1158   static jlong* _jvmci_old_thread_counters;
1159   static void collect_counters(typeArrayOop array);
1160  private:
1161 #endif // INCLUDE_JVMCI
1162 
1163   StackGuardState  _stack_guard_state;
1164 
1165   // Precompute the limit of the stack as used in stack overflow checks.
1166   // We load it from here to simplify the stack overflow check in assembly.
1167   address          _stack_overflow_limit;
1168   address          _reserved_stack_activation;
1169 
1170   // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
1171   // used to temp. parsing values into and out of the runtime system during exception handling for compiled
1172   // code)
1173   volatile oop     _exception_oop;               // Exception thrown in compiled code
1174   volatile address _exception_pc;                // PC where exception happened
1175   volatile address _exception_handler_pc;        // PC for handler of exception
1176   volatile int     _is_method_handle_return;     // true (== 1) if the current exception PC is a MethodHandle call site.
1177 
1178  private:
1179   // support for JNI critical regions
1180   jint    _jni_active_critical;                  // count of entries into JNI critical region
1181 
1182   // Checked JNI: function name requires exception check
1183   char* _pending_jni_exception_check_fn;
1184 
1185   // For deadlock detection.
1186   int _depth_first_number;
1187 
1188   // JVMTI PopFrame support
1189   // This is set to popframe_pending to signal that top Java frame should be popped immediately
1190   int _popframe_condition;
1191 
1192   // If reallocation of scalar replaced objects fails, we throw OOM
1193   // and during exception propagation, pop the top
1194   // _frames_to_pop_failed_realloc frames, the ones that reference
1195   // failed reallocations.
1196   int _frames_to_pop_failed_realloc;
1197 
1198 #ifndef PRODUCT
1199   int _jmp_ring_index;
1200   struct {
1201     // We use intptr_t instead of address so debugger doesn't try and display strings
1202     intptr_t _target;
1203     intptr_t _instruction;
1204     const char*  _file;
1205     int _line;
1206   }   _jmp_ring[jump_ring_buffer_size];
1207 #endif // PRODUCT
1208 
1209   friend class VMThread;
1210   friend class ThreadWaitTransition;
1211   friend class VM_Exit;
1212 
1213   void initialize();                             // Initialized the instance variables
1214 
1215  public:
1216   // Constructor
1217   JavaThread(bool is_attaching_via_jni = false); // for main thread and JNI attached threads
1218   JavaThread(ThreadFunction entry_point, size_t stack_size = 0);
1219   ~JavaThread();
1220 
1221 #ifdef ASSERT
1222   // verify this JavaThread hasn't be published in the Threads::list yet
1223   void verify_not_published();
1224 #endif
1225 
1226   //JNI functiontable getter/setter for JVMTI jni function table interception API.
1227   void set_jni_functions(struct JNINativeInterface_* functionTable) {
1228     _jni_environment.functions = functionTable;
1229   }
1230   struct JNINativeInterface_* get_jni_functions() {
1231     return (struct JNINativeInterface_ *)_jni_environment.functions;
1232   }
1233 
1234   // This function is called at thread creation to allow
1235   // platform specific thread variables to be initialized.
1236   void cache_global_variables();
1237 
1238   // Executes Shutdown.shutdown()
1239   void invoke_shutdown_hooks();
1240 
1241   // Cleanup on thread exit
1242   enum ExitType {
1243     normal_exit,
1244     jni_detach
1245   };
1246   void exit(bool destroy_vm, ExitType exit_type = normal_exit);
1247 
1248   void cleanup_failed_attach_current_thread();
1249 
1250   // Testers
1251   virtual bool is_Java_thread() const            { return true;  }
1252   virtual bool can_call_java() const             { return true; }
1253 
1254   // Thread chain operations
1255   JavaThread* next() const                       { return _next; }
1256   void set_next(JavaThread* p)                   { _next = p; }
1257 
1258   // Thread oop. threadObj() can be NULL for initial JavaThread
1259   // (or for threads attached via JNI)
1260   oop threadObj() const                          { return _threadObj; }
1261   void set_threadObj(oop p)                      { _threadObj = p; }
1262 
1263   ThreadPriority java_priority() const;          // Read from threadObj()
1264 
1265   // Prepare thread and add to priority queue.  If a priority is
1266   // not specified, use the priority of the thread object. Threads_lock
1267   // must be held while this function is called.
1268   void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
1269 
1270   void set_saved_exception_pc(address pc)        { _saved_exception_pc = pc; }
1271   address saved_exception_pc()                   { return _saved_exception_pc; }
1272 
1273 
1274   ThreadFunction entry_point() const             { return _entry_point; }
1275 
1276   // Allocates a new Java level thread object for this thread. thread_name may be NULL.
1277   void allocate_threadObj(Handle thread_group, const char* thread_name, bool daemon, TRAPS);
1278 
1279   // Last frame anchor routines
1280 
1281   JavaFrameAnchor* frame_anchor(void)            { return &_anchor; }
1282 
1283   // last_Java_sp
1284   bool has_last_Java_frame() const               { return _anchor.has_last_Java_frame(); }
1285   intptr_t* last_Java_sp() const                 { return _anchor.last_Java_sp(); }
1286 
1287   // last_Java_pc
1288 
1289   address last_Java_pc(void)                     { return _anchor.last_Java_pc(); }
1290 
1291   // Safepoint support
1292 #if !(defined(PPC64) || defined(AARCH64))
1293   JavaThreadState thread_state() const           { return _thread_state; }
1294   void set_thread_state(JavaThreadState s)       { _thread_state = s;    }
1295 #else
1296   // Use membars when accessing volatile _thread_state. See
1297   // Threads::create_vm() for size checks.
1298   inline JavaThreadState thread_state() const;
1299   inline void set_thread_state(JavaThreadState s);
1300 #endif
1301   inline ThreadSafepointState* safepoint_state() const;
1302   inline void set_safepoint_state(ThreadSafepointState* state);
1303   inline bool is_at_poll_safepoint();
1304 
1305   // JavaThread termination and lifecycle support:
1306   void smr_delete();
1307   bool on_thread_list() const { return _on_thread_list; }
1308   void set_on_thread_list() { _on_thread_list = true; }
1309 
1310   // thread has called JavaThread::exit() or is terminated
1311   bool is_exiting() const;
1312   // thread is terminated (no longer on the threads list); we compare
1313   // against the two non-terminated values so that a freed JavaThread
1314   // will also be considered terminated.
1315   bool check_is_terminated(TerminatedTypes l_terminated) const {
1316     return l_terminated != _not_terminated && l_terminated != _thread_exiting;
1317   }
1318   bool is_terminated() const;
1319   void set_terminated(TerminatedTypes t);
1320   // special for Threads::remove() which is static:
1321   void set_terminated_value();
1322   void block_if_vm_exited();
1323 
1324   bool doing_unsafe_access()                     { return _doing_unsafe_access; }
1325   void set_doing_unsafe_access(bool val)         { _doing_unsafe_access = val; }
1326 
1327   bool do_not_unlock_if_synchronized()             { return _do_not_unlock_if_synchronized; }
1328   void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
1329 
1330   inline void set_polling_page_release(void* poll_value);
1331   inline void set_polling_page(void* poll_value);
1332   inline volatile void* get_polling_page();
1333 
1334  private:
1335   // Support for thread handshake operations
1336   HandshakeState _handshake;
1337  public:
1338   void set_handshake_operation(HandshakeOperation* op) {
1339     _handshake.set_operation(this, op);
1340   }
1341 
1342   bool has_handshake() const {
1343     return _handshake.has_operation();
1344   }
1345 
1346   void handshake_process_by_self() {
1347     _handshake.process_by_self(this);
1348   }
1349 
1350   void handshake_process_by_vmthread() {
1351     _handshake.process_by_vmthread(this);
1352   }
1353 
1354   // Suspend/resume support for JavaThread
1355  private:
1356   inline void set_ext_suspended();
1357   inline void clear_ext_suspended();
1358 
1359  public:
1360   void java_suspend();
1361   void java_resume();
1362   int  java_suspend_self();
1363 
1364   void check_and_wait_while_suspended() {
1365     assert(JavaThread::current() == this, "sanity check");
1366 
1367     bool do_self_suspend;
1368     do {
1369       // were we externally suspended while we were waiting?
1370       do_self_suspend = handle_special_suspend_equivalent_condition();
1371       if (do_self_suspend) {
1372         // don't surprise the thread that suspended us by returning
1373         java_suspend_self();
1374         set_suspend_equivalent();
1375       }
1376     } while (do_self_suspend);
1377   }
1378   static void check_safepoint_and_suspend_for_native_trans(JavaThread *thread);
1379   // Check for async exception in addition to safepoint and suspend request.
1380   static void check_special_condition_for_native_trans(JavaThread *thread);
1381 
1382   // Same as check_special_condition_for_native_trans but finishes the
1383   // transition into thread_in_Java mode so that it can potentially
1384   // block.
1385   static void check_special_condition_for_native_trans_and_transition(JavaThread *thread);
1386 
1387   bool is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits);
1388   bool is_ext_suspend_completed_with_lock(uint32_t *bits) {
1389     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1390     // Warning: is_ext_suspend_completed() may temporarily drop the
1391     // SR_lock to allow the thread to reach a stable thread state if
1392     // it is currently in a transient thread state.
1393     return is_ext_suspend_completed(false /* !called_by_wait */,
1394                                     SuspendRetryDelay, bits);
1395   }
1396 
1397   // We cannot allow wait_for_ext_suspend_completion() to run forever or
1398   // we could hang. SuspendRetryCount and SuspendRetryDelay are normally
1399   // passed as the count and delay parameters. Experiments with specific
1400   // calls to wait_for_ext_suspend_completion() can be done by passing
1401   // other values in the code. Experiments with all calls can be done
1402   // via the appropriate -XX options.
1403   bool wait_for_ext_suspend_completion(int count, int delay, uint32_t *bits);
1404 
1405   // test for suspend - most (all?) of these should go away
1406   bool is_thread_fully_suspended(bool wait_for_suspend, uint32_t *bits);
1407 
1408   inline void set_external_suspend();
1409   inline void clear_external_suspend();
1410 
1411   inline void set_deopt_suspend();
1412   inline void clear_deopt_suspend();
1413   bool is_deopt_suspend()         { return (_suspend_flags & _deopt_suspend) != 0; }
1414 
1415   bool is_external_suspend() const {
1416     return (_suspend_flags & _external_suspend) != 0;
1417   }
1418   // Whenever a thread transitions from native to vm/java it must suspend
1419   // if external|deopt suspend is present.
1420   bool is_suspend_after_native() const {
1421     return (_suspend_flags & (_external_suspend | _deopt_suspend)) != 0;
1422   }
1423 
1424   // external suspend request is completed
1425   bool is_ext_suspended() const {
1426     return (_suspend_flags & _ext_suspended) != 0;
1427   }
1428 
1429   bool is_external_suspend_with_lock() const {
1430     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1431     return is_external_suspend();
1432   }
1433 
1434   // Special method to handle a pending external suspend request
1435   // when a suspend equivalent condition lifts.
1436   bool handle_special_suspend_equivalent_condition() {
1437     assert(is_suspend_equivalent(),
1438            "should only be called in a suspend equivalence condition");
1439     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1440     bool ret = is_external_suspend();
1441     if (!ret) {
1442       // not about to self-suspend so clear suspend equivalence
1443       clear_suspend_equivalent();
1444     }
1445     // implied else:
1446     // We have a pending external suspend request so we leave the
1447     // suspend_equivalent flag set until java_suspend_self() sets
1448     // the ext_suspended flag and clears the suspend_equivalent
1449     // flag. This insures that wait_for_ext_suspend_completion()
1450     // will return consistent values.
1451     return ret;
1452   }
1453 
1454   // utility methods to see if we are doing some kind of suspension
1455   bool is_being_ext_suspended() const            {
1456     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1457     return is_ext_suspended() || is_external_suspend();
1458   }
1459 
1460   bool is_suspend_equivalent() const             { return _suspend_equivalent; }
1461 
1462   void set_suspend_equivalent()                  { _suspend_equivalent = true; }
1463   void clear_suspend_equivalent()                { _suspend_equivalent = false; }
1464 
1465   // Thread.stop support
1466   void send_thread_stop(oop throwable);
1467   AsyncRequests clear_special_runtime_exit_condition() {
1468     AsyncRequests x = _special_runtime_exit_condition;
1469     _special_runtime_exit_condition = _no_async_condition;
1470     return x;
1471   }
1472 
1473   // Are any async conditions present?
1474   bool has_async_condition() { return (_special_runtime_exit_condition != _no_async_condition); }
1475 
1476   void check_and_handle_async_exceptions(bool check_unsafe_error = true);
1477 
1478   // these next two are also used for self-suspension and async exception support
1479   void handle_special_runtime_exit_condition(bool check_asyncs = true);
1480 
1481   // Return true if JavaThread has an asynchronous condition or
1482   // if external suspension is requested.
1483   bool has_special_runtime_exit_condition() {
1484     // Because we don't use is_external_suspend_with_lock
1485     // it is possible that we won't see an asynchronous external suspend
1486     // request that has just gotten started, i.e., SR_lock grabbed but
1487     // _external_suspend field change either not made yet or not visible
1488     // yet. However, this is okay because the request is asynchronous and
1489     // we will see the new flag value the next time through. It's also
1490     // possible that the external suspend request is dropped after
1491     // we have checked is_external_suspend(), we will recheck its value
1492     // under SR_lock in java_suspend_self().
1493     return (_special_runtime_exit_condition != _no_async_condition) ||
1494             is_external_suspend() || is_trace_suspend();
1495   }
1496 
1497   void set_pending_unsafe_access_error()          { _special_runtime_exit_condition = _async_unsafe_access_error; }
1498 
1499   inline void set_pending_async_exception(oop e);
1500 
1501   // Fast-locking support
1502   bool is_lock_owned(address adr) const;
1503 
1504   // Accessors for vframe array top
1505   // The linked list of vframe arrays are sorted on sp. This means when we
1506   // unpack the head must contain the vframe array to unpack.
1507   void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
1508   vframeArray* vframe_array_head() const         { return _vframe_array_head;  }
1509 
1510   // Side structure for deferring update of java frame locals until deopt occurs
1511   GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred_locals() const { return _deferred_locals_updates; }
1512   void set_deferred_locals(GrowableArray<jvmtiDeferredLocalVariableSet *>* vf) { _deferred_locals_updates = vf; }
1513 
1514   // These only really exist to make debugging deopt problems simpler
1515 
1516   void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
1517   vframeArray* vframe_array_last() const         { return _vframe_array_last;  }
1518 
1519   // The special resourceMark used during deoptimization
1520 
1521   void set_deopt_mark(DeoptResourceMark* value)  { _deopt_mark = value; }
1522   DeoptResourceMark* deopt_mark(void)            { return _deopt_mark; }
1523 
1524   intptr_t* must_deopt_id()                      { return _must_deopt_id; }
1525   void     set_must_deopt_id(intptr_t* id)       { _must_deopt_id = id; }
1526   void     clear_must_deopt_id()                 { _must_deopt_id = NULL; }
1527 
1528   void set_deopt_compiled_method(CompiledMethod* nm)  { _deopt_nmethod = nm; }
1529   CompiledMethod* deopt_compiled_method()        { return _deopt_nmethod; }
1530 
1531   Method*    callee_target() const               { return _callee_target; }
1532   void set_callee_target  (Method* x)          { _callee_target   = x; }
1533 
1534   // Oop results of vm runtime calls
1535   oop  vm_result() const                         { return _vm_result; }
1536   void set_vm_result  (oop x)                    { _vm_result   = x; }
1537 
1538   Metadata*    vm_result_2() const               { return _vm_result_2; }
1539   void set_vm_result_2  (Metadata* x)          { _vm_result_2   = x; }
1540 
1541   MemRegion deferred_card_mark() const           { return _deferred_card_mark; }
1542   void set_deferred_card_mark(MemRegion mr)      { _deferred_card_mark = mr;   }
1543 
1544 #if INCLUDE_JVMCI
1545   int  pending_deoptimization() const             { return _pending_deoptimization; }
1546   long pending_failed_speculation() const         { return _pending_failed_speculation; }
1547   bool adjusting_comp_level() const               { return _adjusting_comp_level; }
1548   void set_adjusting_comp_level(bool b)           { _adjusting_comp_level = b; }
1549   bool has_pending_monitorenter() const           { return _pending_monitorenter; }
1550   void set_pending_monitorenter(bool b)           { _pending_monitorenter = b; }
1551   void set_pending_deoptimization(int reason)     { _pending_deoptimization = reason; }
1552   void set_pending_failed_speculation(long failed_speculation) { _pending_failed_speculation = failed_speculation; }
1553   void set_pending_transfer_to_interpreter(bool b) { _pending_transfer_to_interpreter = b; }
1554   void set_jvmci_alternate_call_target(address a) { assert(_jvmci._alternate_call_target == NULL, "must be"); _jvmci._alternate_call_target = a; }
1555   void set_jvmci_implicit_exception_pc(address a) { assert(_jvmci._implicit_exception_pc == NULL, "must be"); _jvmci._implicit_exception_pc = a; }
1556 
1557   virtual bool in_retryable_allocation() const    { return _in_retryable_allocation; }
1558   void set_in_retryable_allocation(bool b)        { _in_retryable_allocation = b; }
1559 #endif // INCLUDE_JVMCI
1560 
1561   // Exception handling for compiled methods
1562   oop      exception_oop() const                 { return _exception_oop; }
1563   address  exception_pc() const                  { return _exception_pc; }
1564   address  exception_handler_pc() const          { return _exception_handler_pc; }
1565   bool     is_method_handle_return() const       { return _is_method_handle_return == 1; }
1566 
1567   void set_exception_oop(oop o)                  { (void)const_cast<oop&>(_exception_oop = o); }
1568   void set_exception_pc(address a)               { _exception_pc = a; }
1569   void set_exception_handler_pc(address a)       { _exception_handler_pc = a; }
1570   void set_is_method_handle_return(bool value)   { _is_method_handle_return = value ? 1 : 0; }
1571 
1572   void clear_exception_oop_and_pc() {
1573     set_exception_oop(NULL);
1574     set_exception_pc(NULL);
1575   }
1576 
1577   // Stack overflow support
1578   //
1579   //  (small addresses)
1580   //
1581   //  --  <-- stack_end()                   ---
1582   //  |                                      |
1583   //  |  red pages                           |
1584   //  |                                      |
1585   //  --  <-- stack_red_zone_base()          |
1586   //  |                                      |
1587   //  |                                     guard
1588   //  |  yellow pages                       zone
1589   //  |                                      |
1590   //  |                                      |
1591   //  --  <-- stack_yellow_zone_base()       |
1592   //  |                                      |
1593   //  |                                      |
1594   //  |  reserved pages                      |
1595   //  |                                      |
1596   //  --  <-- stack_reserved_zone_base()    ---      ---
1597   //                                                 /|\  shadow     <--  stack_overflow_limit() (somewhere in here)
1598   //                                                  |   zone
1599   //                                                 \|/  size
1600   //  some untouched memory                          ---
1601   //
1602   //
1603   //  --
1604   //  |
1605   //  |  shadow zone
1606   //  |
1607   //  --
1608   //  x    frame n
1609   //  --
1610   //  x    frame n-1
1611   //  x
1612   //  --
1613   //  ...
1614   //
1615   //  --
1616   //  x    frame 0
1617   //  --  <-- stack_base()
1618   //
1619   //  (large addresses)
1620   //
1621 
1622  private:
1623   // These values are derived from flags StackRedPages, StackYellowPages,
1624   // StackReservedPages and StackShadowPages. The zone size is determined
1625   // ergonomically if page_size > 4K.
1626   static size_t _stack_red_zone_size;
1627   static size_t _stack_yellow_zone_size;
1628   static size_t _stack_reserved_zone_size;
1629   static size_t _stack_shadow_zone_size;
1630  public:
1631   inline size_t stack_available(address cur_sp);
1632 
1633   static size_t stack_red_zone_size() {
1634     assert(_stack_red_zone_size > 0, "Don't call this before the field is initialized.");
1635     return _stack_red_zone_size;
1636   }
1637   static void set_stack_red_zone_size(size_t s) {
1638     assert(is_aligned(s, os::vm_page_size()),
1639            "We can not protect if the red zone size is not page aligned.");
1640     assert(_stack_red_zone_size == 0, "This should be called only once.");
1641     _stack_red_zone_size = s;
1642   }
1643   address stack_red_zone_base() {
1644     return (address)(stack_end() + stack_red_zone_size());
1645   }
1646   bool in_stack_red_zone(address a) {
1647     return a <= stack_red_zone_base() && a >= stack_end();
1648   }
1649 
1650   static size_t stack_yellow_zone_size() {
1651     assert(_stack_yellow_zone_size > 0, "Don't call this before the field is initialized.");
1652     return _stack_yellow_zone_size;
1653   }
1654   static void set_stack_yellow_zone_size(size_t s) {
1655     assert(is_aligned(s, os::vm_page_size()),
1656            "We can not protect if the yellow zone size is not page aligned.");
1657     assert(_stack_yellow_zone_size == 0, "This should be called only once.");
1658     _stack_yellow_zone_size = s;
1659   }
1660 
1661   static size_t stack_reserved_zone_size() {
1662     // _stack_reserved_zone_size may be 0. This indicates the feature is off.
1663     return _stack_reserved_zone_size;
1664   }
1665   static void set_stack_reserved_zone_size(size_t s) {
1666     assert(is_aligned(s, os::vm_page_size()),
1667            "We can not protect if the reserved zone size is not page aligned.");
1668     assert(_stack_reserved_zone_size == 0, "This should be called only once.");
1669     _stack_reserved_zone_size = s;
1670   }
1671   address stack_reserved_zone_base() {
1672     return (address)(stack_end() +
1673                      (stack_red_zone_size() + stack_yellow_zone_size() + stack_reserved_zone_size()));
1674   }
1675   bool in_stack_reserved_zone(address a) {
1676     return (a <= stack_reserved_zone_base()) &&
1677            (a >= (address)((intptr_t)stack_reserved_zone_base() - stack_reserved_zone_size()));
1678   }
1679 
1680   static size_t stack_yellow_reserved_zone_size() {
1681     return _stack_yellow_zone_size + _stack_reserved_zone_size;
1682   }
1683   bool in_stack_yellow_reserved_zone(address a) {
1684     return (a <= stack_reserved_zone_base()) && (a >= stack_red_zone_base());
1685   }
1686 
1687   // Size of red + yellow + reserved zones.
1688   static size_t stack_guard_zone_size() {
1689     return stack_red_zone_size() + stack_yellow_reserved_zone_size();
1690   }
1691 
1692   static size_t stack_shadow_zone_size() {
1693     assert(_stack_shadow_zone_size > 0, "Don't call this before the field is initialized.");
1694     return _stack_shadow_zone_size;
1695   }
1696   static void set_stack_shadow_zone_size(size_t s) {
1697     // The shadow area is not allocated or protected, so
1698     // it needs not be page aligned.
1699     // But the stack bang currently assumes that it is a
1700     // multiple of page size. This guarantees that the bang
1701     // loop touches all pages in the shadow zone.
1702     // This can be guaranteed differently, as well.  E.g., if
1703     // the page size is a multiple of 4K, banging in 4K steps
1704     // suffices to touch all pages. (Some pages are banged
1705     // several times, though.)
1706     assert(is_aligned(s, os::vm_page_size()),
1707            "Stack bang assumes multiple of page size.");
1708     assert(_stack_shadow_zone_size == 0, "This should be called only once.");
1709     _stack_shadow_zone_size = s;
1710   }
1711 
1712   void create_stack_guard_pages();
1713   void remove_stack_guard_pages();
1714 
1715   void enable_stack_reserved_zone();
1716   void disable_stack_reserved_zone();
1717   void enable_stack_yellow_reserved_zone();
1718   void disable_stack_yellow_reserved_zone();
1719   void enable_stack_red_zone();
1720   void disable_stack_red_zone();
1721 
1722   inline bool stack_guard_zone_unused();
1723   inline bool stack_yellow_reserved_zone_disabled();
1724   inline bool stack_reserved_zone_disabled();
1725   inline bool stack_guards_enabled();
1726 
1727   address reserved_stack_activation() const { return _reserved_stack_activation; }
1728   void set_reserved_stack_activation(address addr) {
1729     assert(_reserved_stack_activation == stack_base()
1730             || _reserved_stack_activation == NULL
1731             || addr == stack_base(), "Must not be set twice");
1732     _reserved_stack_activation = addr;
1733   }
1734 
1735   // Attempt to reguard the stack after a stack overflow may have occurred.
1736   // Returns true if (a) guard pages are not needed on this thread, (b) the
1737   // pages are already guarded, or (c) the pages were successfully reguarded.
1738   // Returns false if there is not enough stack space to reguard the pages, in
1739   // which case the caller should unwind a frame and try again.  The argument
1740   // should be the caller's (approximate) sp.
1741   bool reguard_stack(address cur_sp);
1742   // Similar to above but see if current stackpoint is out of the guard area
1743   // and reguard if possible.
1744   bool reguard_stack(void);
1745 
1746   address stack_overflow_limit() { return _stack_overflow_limit; }
1747   void set_stack_overflow_limit() {
1748     _stack_overflow_limit =
1749       stack_end() + MAX2(JavaThread::stack_guard_zone_size(), JavaThread::stack_shadow_zone_size());
1750   }
1751 
1752   // Misc. accessors/mutators
1753   void set_do_not_unlock(void)                   { _do_not_unlock_if_synchronized = true; }
1754   void clr_do_not_unlock(void)                   { _do_not_unlock_if_synchronized = false; }
1755   bool do_not_unlock(void)                       { return _do_not_unlock_if_synchronized; }
1756 
1757 #ifndef PRODUCT
1758   void record_jump(address target, address instr, const char* file, int line);
1759 #endif // PRODUCT
1760 
1761   // For assembly stub generation
1762   static ByteSize threadObj_offset()             { return byte_offset_of(JavaThread, _threadObj); }
1763 #ifndef PRODUCT
1764   static ByteSize jmp_ring_index_offset()        { return byte_offset_of(JavaThread, _jmp_ring_index); }
1765   static ByteSize jmp_ring_offset()              { return byte_offset_of(JavaThread, _jmp_ring); }
1766 #endif // PRODUCT
1767   static ByteSize jni_environment_offset()       { return byte_offset_of(JavaThread, _jni_environment); }
1768   static ByteSize pending_jni_exception_check_fn_offset() {
1769     return byte_offset_of(JavaThread, _pending_jni_exception_check_fn);
1770   }
1771   static ByteSize last_Java_sp_offset() {
1772     return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
1773   }
1774   static ByteSize last_Java_pc_offset() {
1775     return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
1776   }
1777   static ByteSize frame_anchor_offset() {
1778     return byte_offset_of(JavaThread, _anchor);
1779   }
1780   static ByteSize callee_target_offset()         { return byte_offset_of(JavaThread, _callee_target); }
1781   static ByteSize vm_result_offset()             { return byte_offset_of(JavaThread, _vm_result); }
1782   static ByteSize vm_result_2_offset()           { return byte_offset_of(JavaThread, _vm_result_2); }
1783   static ByteSize thread_state_offset()          { return byte_offset_of(JavaThread, _thread_state); }
1784   static ByteSize saved_exception_pc_offset()    { return byte_offset_of(JavaThread, _saved_exception_pc); }
1785   static ByteSize osthread_offset()              { return byte_offset_of(JavaThread, _osthread); }
1786 #if INCLUDE_JVMCI
1787   static ByteSize pending_deoptimization_offset() { return byte_offset_of(JavaThread, _pending_deoptimization); }
1788   static ByteSize pending_monitorenter_offset()  { return byte_offset_of(JavaThread, _pending_monitorenter); }
1789   static ByteSize pending_failed_speculation_offset() { return byte_offset_of(JavaThread, _pending_failed_speculation); }
1790   static ByteSize jvmci_alternate_call_target_offset() { return byte_offset_of(JavaThread, _jvmci._alternate_call_target); }
1791   static ByteSize jvmci_implicit_exception_pc_offset() { return byte_offset_of(JavaThread, _jvmci._implicit_exception_pc); }
1792   static ByteSize jvmci_counters_offset()        { return byte_offset_of(JavaThread, _jvmci_counters); }
1793 #endif // INCLUDE_JVMCI
1794   static ByteSize exception_oop_offset()         { return byte_offset_of(JavaThread, _exception_oop); }
1795   static ByteSize exception_pc_offset()          { return byte_offset_of(JavaThread, _exception_pc); }
1796   static ByteSize exception_handler_pc_offset()  { return byte_offset_of(JavaThread, _exception_handler_pc); }
1797   static ByteSize stack_overflow_limit_offset()  { return byte_offset_of(JavaThread, _stack_overflow_limit); }
1798   static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); }
1799   static ByteSize stack_guard_state_offset()     { return byte_offset_of(JavaThread, _stack_guard_state); }
1800   static ByteSize reserved_stack_activation_offset() { return byte_offset_of(JavaThread, _reserved_stack_activation); }
1801   static ByteSize suspend_flags_offset()         { return byte_offset_of(JavaThread, _suspend_flags); }
1802 
1803   static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
1804   static ByteSize should_post_on_exceptions_flag_offset() {
1805     return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
1806   }
1807 
1808   // Returns the jni environment for this thread
1809   JNIEnv* jni_environment()                      { return &_jni_environment; }
1810 
1811   static JavaThread* thread_from_jni_environment(JNIEnv* env) {
1812     JavaThread *thread_from_jni_env = (JavaThread*)((intptr_t)env - in_bytes(jni_environment_offset()));
1813     // Only return NULL if thread is off the thread list; starting to
1814     // exit should not return NULL.
1815     if (thread_from_jni_env->is_terminated()) {
1816       thread_from_jni_env->block_if_vm_exited();
1817       return NULL;
1818     } else {
1819       return thread_from_jni_env;
1820     }
1821   }
1822 
1823   // JNI critical regions. These can nest.
1824   bool in_critical()    { return _jni_active_critical > 0; }
1825   bool in_last_critical()  { return _jni_active_critical == 1; }
1826   inline void enter_critical();
1827   void exit_critical() {
1828     assert(Thread::current() == this, "this must be current thread");
1829     _jni_active_critical--;
1830     assert(_jni_active_critical >= 0, "JNI critical nesting problem?");
1831   }
1832 
1833   // Checked JNI: is the programmer required to check for exceptions, if so specify
1834   // which function name. Returning to a Java frame should implicitly clear the
1835   // pending check, this is done for Native->Java transitions (i.e. user JNI code).
1836   // VM->Java transistions are not cleared, it is expected that JNI code enclosed
1837   // within ThreadToNativeFromVM makes proper exception checks (i.e. VM internal).
1838   bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != NULL; }
1839   void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = NULL; }
1840   const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; }
1841   void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; }
1842 
1843   // For deadlock detection
1844   int depth_first_number() { return _depth_first_number; }
1845   void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
1846 
1847  private:
1848   void set_monitor_chunks(MonitorChunk* monitor_chunks) { _monitor_chunks = monitor_chunks; }
1849 
1850  public:
1851   MonitorChunk* monitor_chunks() const           { return _monitor_chunks; }
1852   void add_monitor_chunk(MonitorChunk* chunk);
1853   void remove_monitor_chunk(MonitorChunk* chunk);
1854   bool in_deopt_handler() const                  { return _in_deopt_handler > 0; }
1855   void inc_in_deopt_handler()                    { _in_deopt_handler++; }
1856   void dec_in_deopt_handler() {
1857     assert(_in_deopt_handler > 0, "mismatched deopt nesting");
1858     if (_in_deopt_handler > 0) { // robustness
1859       _in_deopt_handler--;
1860     }
1861   }
1862 
1863  private:
1864   void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
1865 
1866  public:
1867 
1868   // Frame iteration; calls the function f for all frames on the stack
1869   void frames_do(void f(frame*, const RegisterMap*));
1870 
1871   // Memory operations
1872   void oops_do(OopClosure* f, CodeBlobClosure* cf);
1873 
1874   // Sweeper operations
1875   virtual void nmethods_do(CodeBlobClosure* cf);
1876 
1877   // RedefineClasses Support
1878   void metadata_do(void f(Metadata*));
1879 
1880   // Misc. operations
1881   char* name() const { return (char*)get_thread_name(); }
1882   void print_on(outputStream* st, bool print_extended_info) const;
1883   void print_on(outputStream* st) const { print_on(st, false); }
1884   void print_value();
1885   void print_thread_state_on(outputStream*) const      PRODUCT_RETURN;
1886   void print_thread_state() const                      PRODUCT_RETURN;
1887   void print_on_error(outputStream* st, char* buf, int buflen) const;
1888   void print_name_on_error(outputStream* st, char* buf, int buflen) const;
1889   void verify();
1890   const char* get_thread_name() const;
1891  protected:
1892   // factor out low-level mechanics for use in both normal and error cases
1893   virtual const char* get_thread_name_string(char* buf = NULL, int buflen = 0) const;
1894  public:
1895   const char* get_threadgroup_name() const;
1896   const char* get_parent_name() const;
1897 
1898   // Accessing frames
1899   frame last_frame() {
1900     _anchor.make_walkable(this);
1901     return pd_last_frame();
1902   }
1903   javaVFrame* last_java_vframe(RegisterMap* reg_map);
1904 
1905   // Returns method at 'depth' java or native frames down the stack
1906   // Used for security checks
1907   Klass* security_get_caller_class(int depth);
1908 
1909   // Print stack trace in external format
1910   void print_stack_on(outputStream* st);
1911   void print_stack() { print_stack_on(tty); }
1912 
1913   // Print stack traces in various internal formats
1914   void trace_stack()                             PRODUCT_RETURN;
1915   void trace_stack_from(vframe* start_vf)        PRODUCT_RETURN;
1916   void trace_frames()                            PRODUCT_RETURN;
1917   void trace_oops()                              PRODUCT_RETURN;
1918 
1919   // Print an annotated view of the stack frames
1920   void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN;
1921   void validate_frame_layout() {
1922     print_frame_layout(0, true);
1923   }
1924 
1925   // Returns the number of stack frames on the stack
1926   int depth() const;
1927 
1928   // Function for testing deoptimization
1929   void deoptimize();
1930   void make_zombies();
1931 
1932   void deoptimized_wrt_marked_nmethods();
1933 
1934  public:
1935   // Returns the running thread as a JavaThread
1936   static inline JavaThread* current();
1937 
1938   // Returns the active Java thread.  Do not use this if you know you are calling
1939   // from a JavaThread, as it's slower than JavaThread::current.  If called from
1940   // the VMThread, it also returns the JavaThread that instigated the VMThread's
1941   // operation.  You may not want that either.
1942   static JavaThread* active();
1943 
1944   inline CompilerThread* as_CompilerThread();
1945 
1946  protected:
1947   virtual void pre_run();
1948   virtual void run();
1949   void thread_main_inner();
1950   virtual void post_run();
1951 
1952 
1953  private:
1954   GrowableArray<oop>* _array_for_gc;
1955  public:
1956 
1957   void register_array_for_gc(GrowableArray<oop>* array) { _array_for_gc = array; }
1958 
1959  public:
1960   // Thread local information maintained by JVMTI.
1961   void set_jvmti_thread_state(JvmtiThreadState *value)                           { _jvmti_thread_state = value; }
1962   // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1963   // getter is used to get this JavaThread's JvmtiThreadState if it has
1964   // one which means NULL can be returned. JvmtiThreadState::state_for()
1965   // is used to get the specified JavaThread's JvmtiThreadState if it has
1966   // one or it allocates a new JvmtiThreadState for the JavaThread and
1967   // returns it. JvmtiThreadState::state_for() will return NULL only if
1968   // the specified JavaThread is exiting.
1969   JvmtiThreadState *jvmti_thread_state() const                                   { return _jvmti_thread_state; }
1970   static ByteSize jvmti_thread_state_offset()                                    { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1971 
1972   // JVMTI PopFrame support
1973   // Setting and clearing popframe_condition
1974   // All of these enumerated values are bits. popframe_pending
1975   // indicates that a PopFrame() has been requested and not yet been
1976   // completed. popframe_processing indicates that that PopFrame() is in
1977   // the process of being completed. popframe_force_deopt_reexecution_bit
1978   // indicates that special handling is required when returning to a
1979   // deoptimized caller.
1980   enum PopCondition {
1981     popframe_inactive                      = 0x00,
1982     popframe_pending_bit                   = 0x01,
1983     popframe_processing_bit                = 0x02,
1984     popframe_force_deopt_reexecution_bit   = 0x04
1985   };
1986   PopCondition popframe_condition()                   { return (PopCondition) _popframe_condition; }
1987   void set_popframe_condition(PopCondition c)         { _popframe_condition = c; }
1988   void set_popframe_condition_bit(PopCondition c)     { _popframe_condition |= c; }
1989   void clear_popframe_condition()                     { _popframe_condition = popframe_inactive; }
1990   static ByteSize popframe_condition_offset()         { return byte_offset_of(JavaThread, _popframe_condition); }
1991   bool has_pending_popframe()                         { return (popframe_condition() & popframe_pending_bit) != 0; }
1992   bool popframe_forcing_deopt_reexecution()           { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
1993   void clear_popframe_forcing_deopt_reexecution()     { _popframe_condition &= ~popframe_force_deopt_reexecution_bit; }
1994 #ifdef CC_INTERP
1995   bool pop_frame_pending(void)                        { return ((_popframe_condition & popframe_pending_bit) != 0); }
1996   void clr_pop_frame_pending(void)                    { _popframe_condition = popframe_inactive; }
1997   bool pop_frame_in_process(void)                     { return ((_popframe_condition & popframe_processing_bit) != 0); }
1998   void set_pop_frame_in_process(void)                 { _popframe_condition |= popframe_processing_bit; }
1999   void clr_pop_frame_in_process(void)                 { _popframe_condition &= ~popframe_processing_bit; }
2000 #endif
2001 
2002   int frames_to_pop_failed_realloc() const            { return _frames_to_pop_failed_realloc; }
2003   void set_frames_to_pop_failed_realloc(int nb)       { _frames_to_pop_failed_realloc = nb; }
2004   void dec_frames_to_pop_failed_realloc()             { _frames_to_pop_failed_realloc--; }
2005 
2006  private:
2007   // Saved incoming arguments to popped frame.
2008   // Used only when popped interpreted frame returns to deoptimized frame.
2009   void*    _popframe_preserved_args;
2010   int      _popframe_preserved_args_size;
2011 
2012  public:
2013   void  popframe_preserve_args(ByteSize size_in_bytes, void* start);
2014   void* popframe_preserved_args();
2015   ByteSize popframe_preserved_args_size();
2016   WordSize popframe_preserved_args_size_in_words();
2017   void  popframe_free_preserved_args();
2018 
2019 
2020  private:
2021   JvmtiThreadState *_jvmti_thread_state;
2022 
2023   // Used by the interpreter in fullspeed mode for frame pop, method
2024   // entry, method exit and single stepping support. This field is
2025   // only set to non-zero by the VM_EnterInterpOnlyMode VM operation.
2026   // It can be set to zero asynchronously (i.e., without a VM operation
2027   // or a lock) so we have to be very careful.
2028   int               _interp_only_mode;
2029 
2030  public:
2031   // used by the interpreter for fullspeed debugging support (see above)
2032   static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
2033   bool is_interp_only_mode()                { return (_interp_only_mode != 0); }
2034   int get_interp_only_mode()                { return _interp_only_mode; }
2035   void increment_interp_only_mode()         { ++_interp_only_mode; }
2036   void decrement_interp_only_mode()         { --_interp_only_mode; }
2037 
2038   // support for cached flag that indicates whether exceptions need to be posted for this thread
2039   // if this is false, we can avoid deoptimizing when events are thrown
2040   // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
2041  private:
2042   int    _should_post_on_exceptions_flag;
2043 
2044  public:
2045   int   should_post_on_exceptions_flag()  { return _should_post_on_exceptions_flag; }
2046   void  set_should_post_on_exceptions_flag(int val)  { _should_post_on_exceptions_flag = val; }
2047 
2048  private:
2049   ThreadStatistics *_thread_stat;
2050 
2051  public:
2052   ThreadStatistics* get_thread_stat() const    { return _thread_stat; }
2053 
2054   // Return a blocker object for which this thread is blocked parking.
2055   oop current_park_blocker();
2056 
2057  private:
2058   static size_t _stack_size_at_create;
2059 
2060  public:
2061   static inline size_t stack_size_at_create(void) {
2062     return _stack_size_at_create;
2063   }
2064   static inline void set_stack_size_at_create(size_t value) {
2065     _stack_size_at_create = value;
2066   }
2067 
2068   // Machine dependent stuff
2069 #include OS_CPU_HEADER(thread)
2070 
2071  public:
2072   void set_blocked_on_compilation(bool value) {
2073     _blocked_on_compilation = value;
2074   }
2075 
2076   bool blocked_on_compilation() {
2077     return _blocked_on_compilation;
2078   }
2079  protected:
2080   bool         _blocked_on_compilation;
2081 
2082 
2083   // JSR166 per-thread parker
2084  private:
2085   Parker*    _parker;
2086  public:
2087   Parker*     parker() { return _parker; }
2088 
2089   // Biased locking support
2090  private:
2091   GrowableArray<MonitorInfo*>* _cached_monitor_info;
2092  public:
2093   GrowableArray<MonitorInfo*>* cached_monitor_info() { return _cached_monitor_info; }
2094   void set_cached_monitor_info(GrowableArray<MonitorInfo*>* info) { _cached_monitor_info = info; }
2095 
2096   // clearing/querying jni attach status
2097   bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; }
2098   bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
2099   inline void set_done_attaching_via_jni();
2100 };
2101 
2102 // Inline implementation of JavaThread::current
2103 inline JavaThread* JavaThread::current() {
2104   Thread* thread = Thread::current();
2105   assert(thread->is_Java_thread(), "just checking");
2106   return (JavaThread*)thread;
2107 }
2108 
2109 inline CompilerThread* JavaThread::as_CompilerThread() {
2110   assert(is_Compiler_thread(), "just checking");
2111   return (CompilerThread*)this;
2112 }
2113 
2114 // Dedicated thread to sweep the code cache
2115 class CodeCacheSweeperThread : public JavaThread {
2116   CompiledMethod*       _scanned_compiled_method; // nmethod being scanned by the sweeper
2117  public:
2118   CodeCacheSweeperThread();
2119   // Track the nmethod currently being scanned by the sweeper
2120   void set_scanned_compiled_method(CompiledMethod* cm) {
2121     assert(_scanned_compiled_method == NULL || cm == NULL, "should reset to NULL before writing a new value");
2122     _scanned_compiled_method = cm;
2123   }
2124 
2125   // Hide sweeper thread from external view.
2126   bool is_hidden_from_external_view() const { return true; }
2127 
2128   bool is_Code_cache_sweeper_thread() const { return true; }
2129 
2130   // Prevent GC from unloading _scanned_compiled_method
2131   void oops_do(OopClosure* f, CodeBlobClosure* cf);
2132   void nmethods_do(CodeBlobClosure* cf);
2133 };
2134 
2135 // A thread used for Compilation.
2136 class CompilerThread : public JavaThread {
2137   friend class VMStructs;
2138  private:
2139   CompilerCounters* _counters;
2140 
2141   ciEnv*                _env;
2142   CompileLog*           _log;
2143   CompileTask* volatile _task;  // print_threads_compiling can read this concurrently.
2144   CompileQueue*         _queue;
2145   BufferBlob*           _buffer_blob;
2146 
2147   AbstractCompiler*     _compiler;
2148   TimeStamp             _idle_time;
2149 
2150  public:
2151 
2152   static CompilerThread* current();
2153 
2154   CompilerThread(CompileQueue* queue, CompilerCounters* counters);
2155   ~CompilerThread();
2156 
2157   bool is_Compiler_thread() const                { return true; }
2158 
2159   virtual bool can_call_java() const;
2160 
2161   // Hide native compiler threads from external view.
2162   bool is_hidden_from_external_view() const      { return !can_call_java(); }
2163 
2164   void set_compiler(AbstractCompiler* c)         { _compiler = c; }
2165   AbstractCompiler* compiler() const             { return _compiler; }
2166 
2167   CompileQueue* queue()        const             { return _queue; }
2168   CompilerCounters* counters() const             { return _counters; }
2169 
2170   // Get/set the thread's compilation environment.
2171   ciEnv*        env()                            { return _env; }
2172   void          set_env(ciEnv* env)              { _env = env; }
2173 
2174   BufferBlob*   get_buffer_blob() const          { return _buffer_blob; }
2175   void          set_buffer_blob(BufferBlob* b)   { _buffer_blob = b; }
2176 
2177   // Get/set the thread's logging information
2178   CompileLog*   log()                            { return _log; }
2179   void          init_log(CompileLog* log) {
2180     // Set once, for good.
2181     assert(_log == NULL, "set only once");
2182     _log = log;
2183   }
2184 
2185   void start_idle_timer()                        { _idle_time.update(); }
2186   jlong idle_time_millis() {
2187     return TimeHelper::counter_to_millis(_idle_time.ticks_since_update());
2188   }
2189 
2190 #ifndef PRODUCT
2191  private:
2192   IdealGraphPrinter *_ideal_graph_printer;
2193  public:
2194   IdealGraphPrinter *ideal_graph_printer()           { return _ideal_graph_printer; }
2195   void set_ideal_graph_printer(IdealGraphPrinter *n) { _ideal_graph_printer = n; }
2196 #endif
2197 
2198   // Get/set the thread's current task
2199   CompileTask* task()                      { return _task; }
2200   void         set_task(CompileTask* task) { _task = task; }
2201 };
2202 
2203 inline CompilerThread* CompilerThread::current() {
2204   return JavaThread::current()->as_CompilerThread();
2205 }
2206 
2207 // The active thread queue. It also keeps track of the current used
2208 // thread priorities.
2209 class Threads: AllStatic {
2210   friend class VMStructs;
2211  private:
2212   static JavaThread* _thread_list;
2213   static int         _number_of_threads;
2214   static int         _number_of_non_daemon_threads;
2215   static int         _return_code;
2216   static int         _thread_claim_parity;
2217 #ifdef ASSERT
2218   static bool        _vm_complete;
2219 #endif
2220 
2221   static void initialize_java_lang_classes(JavaThread* main_thread, TRAPS);
2222   static void initialize_jsr292_core_classes(TRAPS);
2223 
2224  public:
2225   // Thread management
2226   // force_daemon is a concession to JNI, where we may need to add a
2227   // thread to the thread list before allocating its thread object
2228   static void add(JavaThread* p, bool force_daemon = false);
2229   static void remove(JavaThread* p);
2230   static void non_java_threads_do(ThreadClosure* tc);
2231   static void java_threads_do(ThreadClosure* tc);
2232   static void java_threads_and_vm_thread_do(ThreadClosure* tc);
2233   static void threads_do(ThreadClosure* tc);
2234   static void possibly_parallel_threads_do(bool is_par, ThreadClosure* tc);
2235 
2236   // Initializes the vm and creates the vm thread
2237   static jint create_vm(JavaVMInitArgs* args, bool* canTryAgain);
2238   static void convert_vm_init_libraries_to_agents();
2239   static void create_vm_init_libraries();
2240   static void create_vm_init_agents();
2241   static void shutdown_vm_agents();
2242   static bool destroy_vm();
2243   // Supported VM versions via JNI
2244   // Includes JNI_VERSION_1_1
2245   static jboolean is_supported_jni_version_including_1_1(jint version);
2246   // Does not include JNI_VERSION_1_1
2247   static jboolean is_supported_jni_version(jint version);
2248 
2249   // The "thread claim parity" provides a way for threads to be claimed
2250   // by parallel worker tasks.
2251   //
2252   // Each thread contains a a "parity" field. A task will claim the
2253   // thread only if its parity field is the same as the global parity,
2254   // which is updated by calling change_thread_claim_parity().
2255   //
2256   // For this to work change_thread_claim_parity() needs to be called
2257   // exactly once in sequential code before starting parallel tasks
2258   // that should claim threads.
2259   //
2260   // New threads get their parity set to 0 and change_thread_claim_parity()
2261   // never set the global parity to 0.
2262   static int thread_claim_parity() { return _thread_claim_parity; }
2263   static void change_thread_claim_parity();
2264   static void assert_all_threads_claimed() NOT_DEBUG_RETURN;
2265 
2266   // Apply "f->do_oop" to all root oops in all threads.
2267   // This version may only be called by sequential code.
2268   static void oops_do(OopClosure* f, CodeBlobClosure* cf);
2269   // This version may be called by sequential or parallel code.
2270   static void possibly_parallel_oops_do(bool is_par, OopClosure* f, CodeBlobClosure* cf);
2271 
2272   // Apply "f->do_oop" to roots in all threads that
2273   // are part of compiled frames
2274   static void compiled_frame_oops_do(OopClosure* f, CodeBlobClosure* cf);
2275 
2276   static void convert_hcode_pointers();
2277   static void restore_hcode_pointers();
2278 
2279   // Sweeper
2280   static void nmethods_do(CodeBlobClosure* cf);
2281 
2282   // RedefineClasses support
2283   static void metadata_do(void f(Metadata*));
2284   static void metadata_handles_do(void f(Metadata*));
2285 
2286 #ifdef ASSERT
2287   static bool is_vm_complete() { return _vm_complete; }
2288 #endif // ASSERT
2289 
2290   // Verification
2291   static void verify();
2292   static void print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks, bool print_extended_info);
2293   static void print(bool print_stacks, bool internal_format) {
2294     // this function is only used by debug.cpp
2295     print_on(tty, print_stacks, internal_format, false /* no concurrent lock printed */, false /* simple format */);
2296   }
2297   static void print_on_error(outputStream* st, Thread* current, char* buf, int buflen);
2298   static void print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
2299                              int buflen, bool* found_current);
2300   static void print_threads_compiling(outputStream* st, char* buf, int buflen);
2301 
2302   // Get Java threads that are waiting to enter a monitor.
2303   static GrowableArray<JavaThread*>* get_pending_threads(ThreadsList * t_list,
2304                                                          int count, address monitor);
2305 
2306   // Get owning Java thread from the monitor's owner field.
2307   static JavaThread *owning_thread_from_monitor_owner(ThreadsList * t_list,
2308                                                       address owner);
2309 
2310   // Number of threads on the active threads list
2311   static int number_of_threads()                 { return _number_of_threads; }
2312   // Number of non-daemon threads on the active threads list
2313   static int number_of_non_daemon_threads()      { return _number_of_non_daemon_threads; }
2314 
2315   // Deoptimizes all frames tied to marked nmethods
2316   static void deoptimized_wrt_marked_nmethods();
2317 };
2318 
2319 
2320 // Thread iterator
2321 class ThreadClosure: public StackObj {
2322  public:
2323   virtual void do_thread(Thread* thread) = 0;
2324 };
2325 
2326 class SignalHandlerMark: public StackObj {
2327  private:
2328   Thread* _thread;
2329  public:
2330   SignalHandlerMark(Thread* t) {
2331     _thread = t;
2332     if (_thread) _thread->enter_signal_handler();
2333   }
2334   ~SignalHandlerMark() {
2335     if (_thread) _thread->leave_signal_handler();
2336     _thread = NULL;
2337   }
2338 };
2339 
2340 
2341 #endif // SHARE_VM_RUNTIME_THREAD_HPP