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