1 /*
   2  * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_RUNTIME_THREAD_HPP
  26 #define SHARE_VM_RUNTIME_THREAD_HPP
  27 
  28 #include "jni.h"
  29 #include "code/compiledMethod.hpp"
  30 #include "gc/shared/gcThreadLocalData.hpp"
  31 #include "gc/shared/threadLocalAllocBuffer.hpp"
  32 #include "memory/allocation.hpp"
  33 #include "oops/oop.hpp"
  34 #include "prims/jvmtiExport.hpp"
  35 #include "runtime/frame.hpp"
  36 #include "runtime/globals.hpp"
  37 #include "runtime/handshake.hpp"
  38 #include "runtime/javaFrameAnchor.hpp"
  39 #include "runtime/jniHandles.hpp"
  40 #include "runtime/mutexLocker.hpp"
  41 #include "runtime/os.hpp"
  42 #include "runtime/osThread.hpp"
  43 #include "runtime/park.hpp"
  44 #include "runtime/stubRoutines.hpp"
  45 #include "runtime/threadHeapSampler.hpp"
  46 #include "runtime/threadLocalStorage.hpp"
  47 #include "runtime/threadStatisticalInfo.hpp"
  48 #include "runtime/unhandledOops.hpp"
  49 #include "utilities/align.hpp"
  50 #include "utilities/exceptions.hpp"
  51 #include "utilities/macros.hpp"
  52 #ifdef ZERO
  53 # include "stack_zero.hpp"
  54 #endif
  55 #if INCLUDE_JFR
  56 #include "jfr/support/jfrThreadExtension.hpp"
  57 #endif
  58 
  59 
  60 class SafeThreadsListPtr;
  61 class ThreadSafepointState;
  62 class ThreadsList;
  63 class ThreadsSMRSupport;
  64 
  65 class JvmtiThreadState;
  66 class ThreadStatistics;
  67 class ConcurrentLocksDump;
  68 class ParkEvent;
  69 class Parker;
  70 
  71 class ciEnv;
  72 class CompileThread;
  73 class CompileLog;
  74 class CompileTask;
  75 class CompileQueue;
  76 class CompilerCounters;
  77 class vframeArray;
  78 
  79 class DeoptResourceMark;
  80 class jvmtiDeferredLocalVariableSet;
  81 
  82 class GCTaskQueue;
  83 class ThreadClosure;
  84 class IdealGraphPrinter;
  85 
  86 class Metadata;
  87 template <class T, MEMFLAGS F> class ChunkedList;
  88 typedef ChunkedList<Metadata*, mtInternal> MetadataOnStackBuffer;
  89 
  90 DEBUG_ONLY(class ResourceMark;)
  91 
  92 class WorkerThread;
  93 
  94 // Class hierarchy
  95 // - Thread
  96 //   - JavaThread
  97 //     - various subclasses eg CompilerThread, ServiceThread
  98 //   - NonJavaThread
  99 //     - NamedThread
 100 //       - VMThread
 101 //       - ConcurrentGCThread
 102 //       - WorkerThread
 103 //         - GangWorker
 104 //         - GCTaskThread
 105 //     - WatcherThread
 106 //     - JfrThreadSampler
 107 //
 108 // All Thread subclasses must be either JavaThread or NonJavaThread.
 109 // This means !t->is_Java_thread() iff t is a NonJavaThread, or t is
 110 // a partially constructed/destroyed Thread.
 111 
 112 class Thread: public ThreadShadow {
 113   friend class VMStructs;
 114   friend class JVMCIVMStructs;
 115  private:
 116 
 117 #ifndef USE_LIBRARY_BASED_TLS_ONLY
 118   // Current thread is maintained as a thread-local variable
 119   static THREAD_LOCAL_DECL Thread* _thr_current;
 120 #endif
 121 
 122  private:
 123   // Thread local data area available to the GC. The internal
 124   // structure and contents of this data area is GC-specific.
 125   // Only GC and GC barrier code should access this data area.
 126   GCThreadLocalData _gc_data;
 127 
 128  public:
 129   static ByteSize gc_data_offset() {
 130     return byte_offset_of(Thread, _gc_data);
 131   }
 132 
 133   template <typename T> T* gc_data() {
 134     STATIC_ASSERT(sizeof(T) <= sizeof(_gc_data));
 135     return reinterpret_cast<T*>(&_gc_data);
 136   }
 137 
 138   // Exception handling
 139   // (Note: _pending_exception and friends are in ThreadShadow)
 140   //oop       _pending_exception;                // pending exception for current thread
 141   // const char* _exception_file;                   // file information for exception (debugging only)
 142   // int         _exception_line;                   // line information for exception (debugging only)
 143  protected:
 144   // Support for forcing alignment of thread objects for biased locking
 145   void*       _real_malloc_address;
 146 
 147   // JavaThread lifecycle support:
 148   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
 149   friend class ScanHazardPtrGatherProtectedThreadsClosure;  // for cmpxchg_threads_hazard_ptr(), get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
 150   friend class ScanHazardPtrGatherThreadsListClosure;  // for get_threads_hazard_ptr(), untag_hazard_ptr() access
 151   friend class ScanHazardPtrPrintMatchingThreadsClosure;  // for get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
 152   friend class ThreadsSMRSupport;  // for _nested_threads_hazard_ptr_cnt, _threads_hazard_ptr, _threads_list_ptr access
 153 
 154   ThreadsList* volatile _threads_hazard_ptr;
 155   SafeThreadsListPtr*   _threads_list_ptr;
 156   ThreadsList*          cmpxchg_threads_hazard_ptr(ThreadsList* exchange_value, ThreadsList* compare_value);
 157   ThreadsList*          get_threads_hazard_ptr();
 158   void                  set_threads_hazard_ptr(ThreadsList* new_list);
 159   static bool           is_hazard_ptr_tagged(ThreadsList* list) {
 160     return (intptr_t(list) & intptr_t(1)) == intptr_t(1);
 161   }
 162   static ThreadsList*   tag_hazard_ptr(ThreadsList* list) {
 163     return (ThreadsList*)(intptr_t(list) | intptr_t(1));
 164   }
 165   static ThreadsList*   untag_hazard_ptr(ThreadsList* list) {
 166     return (ThreadsList*)(intptr_t(list) & ~intptr_t(1));
 167   }
 168   // This field is enabled via -XX:+EnableThreadSMRStatistics:
 169   uint _nested_threads_hazard_ptr_cnt;
 170   void dec_nested_threads_hazard_ptr_cnt() {
 171     assert(_nested_threads_hazard_ptr_cnt != 0, "mismatched {dec,inc}_nested_threads_hazard_ptr_cnt()");
 172     _nested_threads_hazard_ptr_cnt--;
 173   }
 174   void inc_nested_threads_hazard_ptr_cnt() {
 175     _nested_threads_hazard_ptr_cnt++;
 176   }
 177   uint nested_threads_hazard_ptr_cnt() {
 178     return _nested_threads_hazard_ptr_cnt;
 179   }
 180 
 181  public:
 182   void* operator new(size_t size) throw() { return allocate(size, true); }
 183   void* operator new(size_t size, const std::nothrow_t& nothrow_constant) throw() {
 184     return allocate(size, false); }
 185   void  operator delete(void* p);
 186 
 187  protected:
 188   static void* allocate(size_t size, bool throw_excpt, MEMFLAGS flags = mtThread);
 189  private:
 190 
 191   // ***************************************************************
 192   // Suspend and resume support
 193   // ***************************************************************
 194   //
 195   // VM suspend/resume no longer exists - it was once used for various
 196   // things including safepoints but was deprecated and finally removed
 197   // in Java 7. Because VM suspension was considered "internal" Java-level
 198   // suspension was considered "external", and this legacy naming scheme
 199   // remains.
 200   //
 201   // External suspend/resume requests come from JVM_SuspendThread,
 202   // JVM_ResumeThread, JVMTI SuspendThread, and finally JVMTI
 203   // ResumeThread. External
 204   // suspend requests cause _external_suspend to be set and external
 205   // resume requests cause _external_suspend to be cleared.
 206   // External suspend requests do not nest on top of other external
 207   // suspend requests. The higher level APIs reject suspend requests
 208   // for already suspended threads.
 209   //
 210   // The external_suspend
 211   // flag is checked by has_special_runtime_exit_condition() and java thread
 212   // will self-suspend when handle_special_runtime_exit_condition() is
 213   // called. Most uses of the _thread_blocked state in JavaThreads are
 214   // considered the same as being externally suspended; if the blocking
 215   // condition lifts, the JavaThread will self-suspend. Other places
 216   // where VM checks for external_suspend include:
 217   //   + mutex granting (do not enter monitors when thread is suspended)
 218   //   + state transitions from _thread_in_native
 219   //
 220   // In general, java_suspend() does not wait for an external suspend
 221   // request to complete. When it returns, the only guarantee is that
 222   // the _external_suspend field is true.
 223   //
 224   // wait_for_ext_suspend_completion() is used to wait for an external
 225   // suspend request to complete. External suspend requests are usually
 226   // followed by some other interface call that requires the thread to
 227   // be quiescent, e.g., GetCallTrace(). By moving the "wait time" into
 228   // the interface that requires quiescence, we give the JavaThread a
 229   // chance to self-suspend before we need it to be quiescent. This
 230   // improves overall suspend/query performance.
 231   //
 232   // _suspend_flags controls the behavior of java_ suspend/resume.
 233   // It must be set under the protection of SR_lock. Read from the flag is
 234   // OK without SR_lock as long as the value is only used as a hint.
 235   // (e.g., check _external_suspend first without lock and then recheck
 236   // inside SR_lock and finish the suspension)
 237   //
 238   // _suspend_flags is also overloaded for other "special conditions" so
 239   // that a single check indicates whether any special action is needed
 240   // eg. for async exceptions.
 241   // -------------------------------------------------------------------
 242   // Notes:
 243   // 1. The suspend/resume logic no longer uses ThreadState in OSThread
 244   // but we still update its value to keep other part of the system (mainly
 245   // JVMTI) happy. ThreadState is legacy code (see notes in
 246   // osThread.hpp).
 247   //
 248   // 2. It would be more natural if set_external_suspend() is private and
 249   // part of java_suspend(), but that probably would affect the suspend/query
 250   // performance. Need more investigation on this.
 251 
 252   // suspend/resume lock: used for self-suspend
 253   Monitor* _SR_lock;
 254 
 255  protected:
 256   enum SuspendFlags {
 257     // NOTE: avoid using the sign-bit as cc generates different test code
 258     //       when the sign-bit is used, and sometimes incorrectly - see CR 6398077
 259 
 260     _external_suspend       = 0x20000000U, // thread is asked to self suspend
 261     _ext_suspended          = 0x40000000U, // thread has self-suspended
 262     _deopt_suspend          = 0x10000000U, // thread needs to self suspend for deopt
 263 
 264     _has_async_exception    = 0x00000001U, // there is a pending async exception
 265     _critical_native_unlock = 0x00000002U, // Must call back to unlock JNI critical lock
 266 
 267     _trace_flag             = 0x00000004U  // call tracing backend
 268   };
 269 
 270   // various suspension related flags - atomically updated
 271   // overloaded for async exception checking in check_special_condition_for_native_trans.
 272   volatile uint32_t _suspend_flags;
 273 
 274  private:
 275   int _num_nested_signal;
 276 
 277   DEBUG_ONLY(bool _suspendible_thread;)
 278 
 279  public:
 280   void enter_signal_handler() { _num_nested_signal++; }
 281   void leave_signal_handler() { _num_nested_signal--; }
 282   bool is_inside_signal_handler() const { return _num_nested_signal > 0; }
 283 
 284   // Determines if a heap allocation failure will be retried
 285   // (e.g., by deoptimizing and re-executing in the interpreter).
 286   // In this case, the failed allocation must raise
 287   // Universe::out_of_memory_error_retry() and omit side effects
 288   // such as JVMTI events and handling -XX:+HeapDumpOnOutOfMemoryError
 289   // and -XX:OnOutOfMemoryError.
 290   virtual bool in_retryable_allocation() const { return false; }
 291 
 292 #ifdef ASSERT
 293   void set_suspendible_thread() {
 294     _suspendible_thread = true;
 295   }
 296 
 297   void clear_suspendible_thread() {
 298     _suspendible_thread = false;
 299   }
 300 
 301   bool is_suspendible_thread() { return _suspendible_thread; }
 302 #endif
 303 
 304  private:
 305   // Active_handles points to a block of handles
 306   JNIHandleBlock* _active_handles;
 307 
 308   // One-element thread local free list
 309   JNIHandleBlock* _free_handle_block;
 310 
 311   // Point to the last handle mark
 312   HandleMark* _last_handle_mark;
 313 
 314   // The parity of the last strong_roots iteration in which this thread was
 315   // claimed as a task.
 316   int _oops_do_parity;
 317 
 318   // Support for GlobalCounter
 319  private:
 320   volatile uintx _rcu_counter;
 321  public:
 322   volatile uintx* get_rcu_counter() {
 323     return &_rcu_counter;
 324   }
 325 
 326  public:
 327   void set_last_handle_mark(HandleMark* mark)   { _last_handle_mark = mark; }
 328   HandleMark* last_handle_mark() const          { return _last_handle_mark; }
 329  private:
 330 
 331 #ifdef ASSERT
 332   void* _missed_ic_stub_refill_mark;
 333 
 334  public:
 335   void* missed_ic_stub_refill_mark() {
 336     return _missed_ic_stub_refill_mark;
 337   }
 338 
 339   void set_missed_ic_stub_refill_mark(void* mark) {
 340     _missed_ic_stub_refill_mark = mark;
 341   }
 342 #endif
 343 
 344  private:
 345 
 346   // debug support for checking if code does allow safepoints or not
 347   // GC points in the VM can happen because of allocation, invoking a VM operation, or blocking on
 348   // mutex, or blocking on an object synchronizer (Java locking).
 349   // If !allow_safepoint(), then an assertion failure will happen in any of the above cases
 350   // If !allow_allocation(), then an assertion failure will happen during allocation
 351   // (Hence, !allow_safepoint() => !allow_allocation()).
 352   //
 353   // The two classes NoSafepointVerifier and No_Allocation_Verifier are used to set these counters.
 354   //
 355   NOT_PRODUCT(int _allow_safepoint_count;)      // If 0, thread allow a safepoint to happen
 356   debug_only(int _allow_allocation_count;)     // If 0, the thread is allowed to allocate oops.
 357 
 358   // Used by SkipGCALot class.
 359   NOT_PRODUCT(bool _skip_gcalot;)               // Should we elide gc-a-lot?
 360 
 361   friend class NoAllocVerifier;
 362   friend class NoSafepointVerifier;
 363   friend class PauseNoSafepointVerifier;
 364   friend class GCLocker;
 365 
 366   volatile void* _polling_page;                 // Thread local polling page
 367 
 368   ThreadLocalAllocBuffer _tlab;                 // Thread-local eden
 369   jlong _allocated_bytes;                       // Cumulative number of bytes allocated on
 370                                                 // the Java heap
 371   ThreadHeapSampler _heap_sampler;              // For use when sampling the memory.
 372 
 373   ThreadStatisticalInfo _statistical_info;      // Statistics about the thread
 374 
 375   JFR_ONLY(DEFINE_THREAD_LOCAL_FIELD_JFR;)      // Thread-local data for jfr
 376 
 377   int   _vm_operation_started_count;            // VM_Operation support
 378   int   _vm_operation_completed_count;          // VM_Operation support
 379 
 380   ObjectMonitor* _current_pending_monitor;      // ObjectMonitor this thread
 381                                                 // is waiting to lock
 382   bool _current_pending_monitor_is_from_java;   // locking is from Java code
 383 
 384   // ObjectMonitor on which this thread called Object.wait()
 385   ObjectMonitor* _current_waiting_monitor;
 386 
 387   // Private thread-local objectmonitor list - a simple cache organized as a SLL.
 388  public:
 389   ObjectMonitor* omFreeList;
 390   int omFreeCount;                              // length of omFreeList
 391   int omFreeProvision;                          // reload chunk size
 392   ObjectMonitor* omInUseList;                   // SLL to track monitors in circulation
 393   int omInUseCount;                             // length of omInUseList
 394 
 395 #ifdef ASSERT
 396  private:
 397   bool _visited_for_critical_count;
 398 
 399  public:
 400   void set_visited_for_critical_count(bool z) { _visited_for_critical_count = z; }
 401   bool was_visited_for_critical_count() const   { return _visited_for_critical_count; }
 402 #endif
 403 
 404  public:
 405   enum {
 406     is_definitely_current_thread = true
 407   };
 408 
 409   // Constructor
 410   Thread();
 411   virtual ~Thread() = 0;        // Thread is abstract.
 412 
 413   // Manage Thread::current()
 414   void initialize_thread_current();
 415   static void clear_thread_current(); // TLS cleanup needed before threads terminate
 416 
 417  protected:
 418   // To be implemented by children.
 419   virtual void run() = 0;
 420 
 421  public:
 422   // invokes <ChildThreadClass>::run(), with common preparations and cleanups.
 423   void call_run();
 424 
 425   // Testers
 426   virtual bool is_VM_thread()       const            { return false; }
 427   virtual bool is_Java_thread()     const            { return false; }
 428   virtual bool is_Compiler_thread() const            { return false; }
 429   virtual bool is_Code_cache_sweeper_thread() const  { return false; }
 430   virtual bool is_hidden_from_external_view() const  { return false; }
 431   virtual bool is_jvmti_agent_thread() const         { return false; }
 432   // True iff the thread can perform GC operations at a safepoint.
 433   // Generally will be true only of VM thread and parallel GC WorkGang
 434   // threads.
 435   virtual bool is_GC_task_thread() const             { return false; }
 436   virtual bool is_Watcher_thread() const             { return false; }
 437   virtual bool is_ConcurrentGC_thread() const        { return false; }
 438   virtual bool is_Named_thread() const               { return false; }
 439   virtual bool is_Worker_thread() const              { return false; }
 440 
 441   // Can this thread make Java upcalls
 442   virtual bool can_call_java() const                 { return false; }
 443 
 444   // Casts
 445   virtual WorkerThread* as_Worker_thread() const     { return NULL; }
 446 
 447   virtual char* name() const { return (char*)"Unknown thread"; }
 448 
 449   // Returns the current thread (ASSERTS if NULL)
 450   static inline Thread* current();
 451   // Returns the current thread, or NULL if not attached
 452   static inline Thread* current_or_null();
 453   // Returns the current thread, or NULL if not attached, and is
 454   // safe for use from signal-handlers
 455   static inline Thread* current_or_null_safe();
 456 
 457   // Common thread operations
 458 #ifdef ASSERT
 459   static void check_for_dangling_thread_pointer(Thread *thread);
 460 #endif
 461   static void set_priority(Thread* thread, ThreadPriority priority);
 462   static ThreadPriority get_priority(const Thread* const thread);
 463   static void start(Thread* thread);
 464   static void interrupt(Thread* thr);
 465   static bool is_interrupted(Thread* thr, bool clear_interrupted);
 466 
 467   void set_native_thread_name(const char *name) {
 468     assert(Thread::current() == this, "set_native_thread_name can only be called on the current thread");
 469     os::set_native_thread_name(name);
 470   }
 471 
 472   ObjectMonitor** omInUseList_addr()             { return (ObjectMonitor **)&omInUseList; }
 473   Monitor* SR_lock() const                       { return _SR_lock; }
 474 
 475   bool has_async_exception() const { return (_suspend_flags & _has_async_exception) != 0; }
 476 
 477   inline void set_suspend_flag(SuspendFlags f);
 478   inline void clear_suspend_flag(SuspendFlags f);
 479 
 480   inline void set_has_async_exception();
 481   inline void clear_has_async_exception();
 482 
 483   bool do_critical_native_unlock() const { return (_suspend_flags & _critical_native_unlock) != 0; }
 484 
 485   inline void set_critical_native_unlock();
 486   inline void clear_critical_native_unlock();
 487 
 488   inline void set_trace_flag();
 489   inline void clear_trace_flag();
 490 
 491   // Support for Unhandled Oop detection
 492   // Add the field for both, fastdebug and debug, builds to keep
 493   // Thread's fields layout the same.
 494   // Note: CHECK_UNHANDLED_OOPS is defined only for fastdebug build.
 495 #ifdef CHECK_UNHANDLED_OOPS
 496  private:
 497   UnhandledOops* _unhandled_oops;
 498 #elif defined(ASSERT)
 499  private:
 500   void* _unhandled_oops;
 501 #endif
 502 #ifdef CHECK_UNHANDLED_OOPS
 503  public:
 504   UnhandledOops* unhandled_oops() { return _unhandled_oops; }
 505   // Mark oop safe for gc.  It may be stack allocated but won't move.
 506   void allow_unhandled_oop(oop *op) {
 507     if (CheckUnhandledOops) unhandled_oops()->allow_unhandled_oop(op);
 508   }
 509   // Clear oops at safepoint so crashes point to unhandled oop violator
 510   void clear_unhandled_oops() {
 511     if (CheckUnhandledOops) unhandled_oops()->clear_unhandled_oops();
 512   }
 513 #endif // CHECK_UNHANDLED_OOPS
 514 
 515  public:
 516 #ifndef PRODUCT
 517   bool skip_gcalot()           { return _skip_gcalot; }
 518   void set_skip_gcalot(bool v) { _skip_gcalot = v;    }
 519 #endif
 520 
 521   // Installs a pending exception to be inserted later
 522   static void send_async_exception(oop thread_oop, oop java_throwable);
 523 
 524   // Resource area
 525   ResourceArea* resource_area() const            { return _resource_area; }
 526   void set_resource_area(ResourceArea* area)     { _resource_area = area; }
 527 
 528   OSThread* osthread() const                     { return _osthread;   }
 529   void set_osthread(OSThread* thread)            { _osthread = thread; }
 530 
 531   // JNI handle support
 532   JNIHandleBlock* active_handles() const         { return _active_handles; }
 533   void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
 534   JNIHandleBlock* free_handle_block() const      { return _free_handle_block; }
 535   void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
 536 
 537   // Internal handle support
 538   HandleArea* handle_area() const                { return _handle_area; }
 539   void set_handle_area(HandleArea* area)         { _handle_area = area; }
 540 
 541   GrowableArray<Metadata*>* metadata_handles() const          { return _metadata_handles; }
 542   void set_metadata_handles(GrowableArray<Metadata*>* handles){ _metadata_handles = handles; }
 543 
 544   // Thread-Local Allocation Buffer (TLAB) support
 545   ThreadLocalAllocBuffer& tlab()                 { return _tlab; }
 546   void initialize_tlab() {
 547     if (UseTLAB) {
 548       tlab().initialize();
 549     }
 550   }
 551 
 552   jlong allocated_bytes()               { return _allocated_bytes; }
 553   void set_allocated_bytes(jlong value) { _allocated_bytes = value; }
 554   void incr_allocated_bytes(jlong size) { _allocated_bytes += size; }
 555   inline jlong cooked_allocated_bytes();
 556 
 557   ThreadHeapSampler& heap_sampler()     { return _heap_sampler; }
 558 
 559   ThreadStatisticalInfo& statistical_info() { return _statistical_info; }
 560 
 561   JFR_ONLY(DEFINE_THREAD_LOCAL_ACCESSOR_JFR;)
 562 
 563   bool is_trace_suspend()               { return (_suspend_flags & _trace_flag) != 0; }
 564 
 565   // VM operation support
 566   int vm_operation_ticket()                      { return ++_vm_operation_started_count; }
 567   int vm_operation_completed_count()             { return _vm_operation_completed_count; }
 568   void increment_vm_operation_completed_count()  { _vm_operation_completed_count++; }
 569 
 570   // For tracking the heavyweight monitor the thread is pending on.
 571   ObjectMonitor* current_pending_monitor() {
 572     return _current_pending_monitor;
 573   }
 574   void set_current_pending_monitor(ObjectMonitor* monitor) {
 575     _current_pending_monitor = monitor;
 576   }
 577   void set_current_pending_monitor_is_from_java(bool from_java) {
 578     _current_pending_monitor_is_from_java = from_java;
 579   }
 580   bool current_pending_monitor_is_from_java() {
 581     return _current_pending_monitor_is_from_java;
 582   }
 583 
 584   // For tracking the ObjectMonitor on which this thread called Object.wait()
 585   ObjectMonitor* current_waiting_monitor() {
 586     return _current_waiting_monitor;
 587   }
 588   void set_current_waiting_monitor(ObjectMonitor* monitor) {
 589     _current_waiting_monitor = monitor;
 590   }
 591 
 592   // GC support
 593   // Apply "f->do_oop" to all root oops in "this".
 594   //   Used by JavaThread::oops_do.
 595   // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames
 596   virtual void oops_do(OopClosure* f, CodeBlobClosure* cf);
 597 
 598   // Handles the parallel case for the method below.
 599  private:
 600   bool claim_oops_do_par_case(int collection_parity);
 601  public:
 602   // Requires that "collection_parity" is that of the current roots
 603   // iteration.  If "is_par" is false, sets the parity of "this" to
 604   // "collection_parity", and returns "true".  If "is_par" is true,
 605   // uses an atomic instruction to set the current threads parity to
 606   // "collection_parity", if it is not already.  Returns "true" iff the
 607   // calling thread does the update, this indicates that the calling thread
 608   // has claimed the thread's stack as a root groop in the current
 609   // collection.
 610   bool claim_oops_do(bool is_par, int collection_parity) {
 611     if (!is_par) {
 612       _oops_do_parity = collection_parity;
 613       return true;
 614     } else {
 615       return claim_oops_do_par_case(collection_parity);
 616     }
 617   }
 618 
 619   // jvmtiRedefineClasses support
 620   void metadata_handles_do(void f(Metadata*));
 621 
 622   // Used by fast lock support
 623   virtual bool is_lock_owned(address adr) const;
 624 
 625   // Check if address is in the stack of the thread (not just for locks).
 626   // Warning: the method can only be used on the running thread
 627   bool is_in_stack(address adr) const;
 628   // Check if address is in the usable part of the stack (excludes protected
 629   // guard pages)
 630   bool is_in_usable_stack(address adr) const;
 631 
 632   // Sets this thread as starting thread. Returns failure if thread
 633   // creation fails due to lack of memory, too many threads etc.
 634   bool set_as_starting_thread();
 635 
 636 protected:
 637   // OS data associated with the thread
 638   OSThread* _osthread;  // Platform-specific thread information
 639 
 640   // Thread local resource area for temporary allocation within the VM
 641   ResourceArea* _resource_area;
 642 
 643   DEBUG_ONLY(ResourceMark* _current_resource_mark;)
 644 
 645   // Thread local handle area for allocation of handles within the VM
 646   HandleArea* _handle_area;
 647   GrowableArray<Metadata*>* _metadata_handles;
 648 
 649   // Support for stack overflow handling, get_thread, etc.
 650   address          _stack_base;
 651   size_t           _stack_size;
 652   uintptr_t        _self_raw_id;      // used by get_thread (mutable)
 653   int              _lgrp_id;
 654 
 655   volatile void** polling_page_addr() { return &_polling_page; }
 656 
 657  public:
 658   // Stack overflow support
 659   address stack_base() const           { assert(_stack_base != NULL,"Sanity check"); return _stack_base; }
 660   void    set_stack_base(address base) { _stack_base = base; }
 661   size_t  stack_size() const           { return _stack_size; }
 662   void    set_stack_size(size_t size)  { _stack_size = size; }
 663   address stack_end()  const           { return stack_base() - stack_size(); }
 664   void    record_stack_base_and_size();
 665   void    register_thread_stack_with_NMT() NOT_NMT_RETURN;
 666 
 667   bool    on_local_stack(address adr) const {
 668     // QQQ this has knowledge of direction, ought to be a stack method
 669     return (_stack_base >= adr && adr >= stack_end());
 670   }
 671 
 672   uintptr_t self_raw_id()                    { return _self_raw_id; }
 673   void      set_self_raw_id(uintptr_t value) { _self_raw_id = value; }
 674 
 675   int     lgrp_id() const        { return _lgrp_id; }
 676   void    set_lgrp_id(int value) { _lgrp_id = value; }
 677 
 678   // Printing
 679   void print_on(outputStream* st, bool print_extended_info) const;
 680   virtual void print_on(outputStream* st) const { print_on(st, false); }
 681   void print() const { print_on(tty); }
 682   virtual void print_on_error(outputStream* st, char* buf, int buflen) const;
 683   void print_value_on(outputStream* st) const;
 684 
 685   // Debug-only code
 686 #ifdef ASSERT
 687  private:
 688   // Deadlock detection support for Mutex locks. List of locks own by thread.
 689   Monitor* _owned_locks;
 690   // Mutex::set_owner_implementation is the only place where _owned_locks is modified,
 691   // thus the friendship
 692   friend class Mutex;
 693   friend class Monitor;
 694 
 695  public:
 696   void print_owned_locks_on(outputStream* st) const;
 697   void print_owned_locks() const                 { print_owned_locks_on(tty);    }
 698   Monitor* owned_locks() const                   { return _owned_locks;          }
 699   bool owns_locks() const                        { return owned_locks() != NULL; }
 700   bool owns_locks_but_compiled_lock() const;
 701   int oops_do_parity() const                     { return _oops_do_parity; }
 702 
 703   // Deadlock detection
 704   bool allow_allocation()                        { return _allow_allocation_count == 0; }
 705   ResourceMark* current_resource_mark()          { return _current_resource_mark; }
 706   void set_current_resource_mark(ResourceMark* rm) { _current_resource_mark = rm; }
 707 #endif
 708 
 709   void check_for_valid_safepoint_state(bool potential_vm_operation) PRODUCT_RETURN;
 710 
 711  private:
 712   volatile int _jvmti_env_iteration_count;
 713 
 714  public:
 715   void entering_jvmti_env_iteration()            { ++_jvmti_env_iteration_count; }
 716   void leaving_jvmti_env_iteration()             { --_jvmti_env_iteration_count; }
 717   bool is_inside_jvmti_env_iteration()           { return _jvmti_env_iteration_count > 0; }
 718 
 719   // Code generation
 720   static ByteSize exception_file_offset()        { return byte_offset_of(Thread, _exception_file); }
 721   static ByteSize exception_line_offset()        { return byte_offset_of(Thread, _exception_line); }
 722   static ByteSize active_handles_offset()        { return byte_offset_of(Thread, _active_handles); }
 723 
 724   static ByteSize stack_base_offset()            { return byte_offset_of(Thread, _stack_base); }
 725   static ByteSize stack_size_offset()            { return byte_offset_of(Thread, _stack_size); }
 726 
 727   static ByteSize polling_page_offset()          { return byte_offset_of(Thread, _polling_page); }
 728 
 729   static ByteSize tlab_start_offset()            { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::start_offset(); }
 730   static ByteSize tlab_end_offset()              { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::end_offset(); }
 731   static ByteSize tlab_top_offset()              { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::top_offset(); }
 732   static ByteSize tlab_pf_top_offset()           { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::pf_top_offset(); }
 733 
 734   static ByteSize allocated_bytes_offset()       { return byte_offset_of(Thread, _allocated_bytes); }
 735 
 736   JFR_ONLY(DEFINE_THREAD_LOCAL_OFFSET_JFR;)
 737 
 738  public:
 739   volatile intptr_t _Stalled;
 740   volatile int _TypeTag;
 741   ParkEvent * _ParkEvent;                     // for synchronized()
 742   ParkEvent * _SleepEvent;                    // for Thread.sleep
 743   ParkEvent * _MutexEvent;                    // for native internal Mutex/Monitor
 744   ParkEvent * _MuxEvent;                      // for low-level muxAcquire-muxRelease
 745   int NativeSyncRecursion;                    // diagnostic
 746 
 747   volatile int _OnTrap;                       // Resume-at IP delta
 748   jint _hashStateW;                           // Marsaglia Shift-XOR thread-local RNG
 749   jint _hashStateX;                           // thread-specific hashCode generator state
 750   jint _hashStateY;
 751   jint _hashStateZ;
 752 
 753   volatile jint rng[4];                      // RNG for spin loop
 754 
 755   // Low-level leaf-lock primitives used to implement synchronization
 756   // and native monitor-mutex infrastructure.
 757   // Not for general synchronization use.
 758   static void SpinAcquire(volatile int * Lock, const char * Name);
 759   static void SpinRelease(volatile int * Lock);
 760   static void muxAcquire(volatile intptr_t * Lock, const char * Name);
 761   static void muxAcquireW(volatile intptr_t * Lock, ParkEvent * ev);
 762   static void muxRelease(volatile intptr_t * Lock);
 763 };
 764 
 765 // Inline implementation of Thread::current()
 766 inline Thread* Thread::current() {
 767   Thread* current = current_or_null();
 768   assert(current != NULL, "Thread::current() called on detached thread");
 769   return current;
 770 }
 771 
 772 inline Thread* Thread::current_or_null() {
 773 #ifndef USE_LIBRARY_BASED_TLS_ONLY
 774   return _thr_current;
 775 #else
 776   if (ThreadLocalStorage::is_initialized()) {
 777     return ThreadLocalStorage::thread();
 778   }
 779   return NULL;
 780 #endif
 781 }
 782 
 783 inline Thread* Thread::current_or_null_safe() {
 784   if (ThreadLocalStorage::is_initialized()) {
 785     return ThreadLocalStorage::thread();
 786   }
 787   return NULL;
 788 }
 789 
 790 class NonJavaThread: public Thread {
 791   friend class VMStructs;
 792 
 793   NonJavaThread* volatile _next;
 794 
 795   class List;
 796   static List _the_list;
 797 
 798  public:
 799   NonJavaThread();
 800   ~NonJavaThread();
 801 
 802   class Iterator;
 803 };
 804 
 805 // Provides iteration over the list of NonJavaThreads.  Because list
 806 // management occurs in the NonJavaThread constructor and destructor,
 807 // entries in the list may not be fully constructed instances of a
 808 // derived class.  Threads created after an iterator is constructed
 809 // will not be visited by the iterator.  The scope of an iterator is a
 810 // critical section; there must be no safepoint checks in that scope.
 811 class NonJavaThread::Iterator : public StackObj {
 812   uint _protect_enter;
 813   NonJavaThread* _current;
 814 
 815   // Noncopyable.
 816   Iterator(const Iterator&);
 817   Iterator& operator=(const Iterator&);
 818 
 819 public:
 820   Iterator();
 821   ~Iterator();
 822 
 823   bool end() const { return _current == NULL; }
 824   NonJavaThread* current() const { return _current; }
 825   void step();
 826 };
 827 
 828 // Name support for threads.  non-JavaThread subclasses with multiple
 829 // uniquely named instances should derive from this.
 830 class NamedThread: public NonJavaThread {
 831   friend class VMStructs;
 832   enum {
 833     max_name_len = 64
 834   };
 835  private:
 836   char* _name;
 837   // log JavaThread being processed by oops_do
 838   JavaThread* _processed_thread;
 839   uint _gc_id; // The current GC id when a thread takes part in GC
 840 
 841  public:
 842   NamedThread();
 843   ~NamedThread();
 844   // May only be called once per thread.
 845   void set_name(const char* format, ...)  ATTRIBUTE_PRINTF(2, 3);
 846   void initialize_named_thread();
 847   virtual bool is_Named_thread() const { return true; }
 848   virtual char* name() const { return _name == NULL ? (char*)"Unknown Thread" : _name; }
 849   JavaThread *processed_thread() { return _processed_thread; }
 850   void set_processed_thread(JavaThread *thread) { _processed_thread = thread; }
 851   virtual void print_on(outputStream* st) const;
 852 
 853   void set_gc_id(uint gc_id) { _gc_id = gc_id; }
 854   uint gc_id() { return _gc_id; }
 855 };
 856 
 857 // Worker threads are named and have an id of an assigned work.
 858 class WorkerThread: public NamedThread {
 859  private:
 860   uint _id;
 861  public:
 862   WorkerThread() : _id(0)               { }
 863   virtual bool is_Worker_thread() const { return true; }
 864 
 865   virtual WorkerThread* as_Worker_thread() const {
 866     assert(is_Worker_thread(), "Dubious cast to WorkerThread*?");
 867     return (WorkerThread*) this;
 868   }
 869 
 870   void set_id(uint work_id)             { _id = work_id; }
 871   uint id() const                       { return _id; }
 872 };
 873 
 874 // A single WatcherThread is used for simulating timer interrupts.
 875 class WatcherThread: public NonJavaThread {
 876   friend class VMStructs;
 877  public:
 878   virtual void run();
 879 
 880  private:
 881   static WatcherThread* _watcher_thread;
 882 
 883   static bool _startable;
 884   // volatile due to at least one lock-free read
 885   volatile static bool _should_terminate;
 886  public:
 887   enum SomeConstants {
 888     delay_interval = 10                          // interrupt delay in milliseconds
 889   };
 890 
 891   // Constructor
 892   WatcherThread();
 893 
 894   // No destruction allowed
 895   ~WatcherThread() {
 896     guarantee(false, "WatcherThread deletion must fix the race with VM termination");
 897   }
 898 
 899   // Tester
 900   bool is_Watcher_thread() const                 { return true; }
 901 
 902   // Printing
 903   char* name() const { return (char*)"VM Periodic Task Thread"; }
 904   void print_on(outputStream* st) const;
 905   void unpark();
 906 
 907   // Returns the single instance of WatcherThread
 908   static WatcherThread* watcher_thread()         { return _watcher_thread; }
 909 
 910   // Create and start the single instance of WatcherThread, or stop it on shutdown
 911   static void start();
 912   static void stop();
 913   // Only allow start once the VM is sufficiently initialized
 914   // Otherwise the first task to enroll will trigger the start
 915   static void make_startable();
 916  private:
 917   int sleep() const;
 918 };
 919 
 920 
 921 class CompilerThread;
 922 
 923 typedef void (*ThreadFunction)(JavaThread*, TRAPS);
 924 
 925 class JavaThread: public Thread {
 926   friend class VMStructs;
 927   friend class JVMCIVMStructs;
 928   friend class WhiteBox;
 929  private:
 930   JavaThread*    _next;                          // The next thread in the Threads list
 931   bool           _on_thread_list;                // Is set when this JavaThread is added to the Threads list
 932   oop            _threadObj;                     // The Java level thread object
 933 
 934 #ifdef ASSERT
 935  private:
 936   int _java_call_counter;
 937 
 938  public:
 939   int  java_call_counter()                       { return _java_call_counter; }
 940   void inc_java_call_counter()                   { _java_call_counter++; }
 941   void dec_java_call_counter() {
 942     assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
 943     _java_call_counter--;
 944   }
 945  private:  // restore original namespace restriction
 946 #endif  // ifdef ASSERT
 947 
 948 #ifndef PRODUCT
 949  public:
 950   enum {
 951     jump_ring_buffer_size = 16
 952   };
 953  private:  // restore original namespace restriction
 954 #endif
 955 
 956   JavaFrameAnchor _anchor;                       // Encapsulation of current java frame and it state
 957 
 958   ThreadFunction _entry_point;
 959 
 960   JNIEnv        _jni_environment;
 961 
 962   // Deopt support
 963   DeoptResourceMark*  _deopt_mark;               // Holds special ResourceMark for deoptimization
 964 
 965   intptr_t*      _must_deopt_id;                 // id of frame that needs to be deopted once we
 966                                                  // transition out of native
 967   CompiledMethod*       _deopt_nmethod;         // CompiledMethod that is currently being deoptimized
 968   vframeArray*  _vframe_array_head;              // Holds the heap of the active vframeArrays
 969   vframeArray*  _vframe_array_last;              // Holds last vFrameArray we popped
 970   // Because deoptimization is lazy we must save jvmti requests to set locals
 971   // in compiled frames until we deoptimize and we have an interpreter frame.
 972   // This holds the pointer to array (yeah like there might be more than one) of
 973   // description of compiled vframes that have locals that need to be updated.
 974   GrowableArray<jvmtiDeferredLocalVariableSet*>* _deferred_locals_updates;
 975 
 976   // Handshake value for fixing 6243940. We need a place for the i2c
 977   // adapter to store the callee Method*. This value is NEVER live
 978   // across a gc point so it does NOT have to be gc'd
 979   // The handshake is open ended since we can't be certain that it will
 980   // be NULLed. This is because we rarely ever see the race and end up
 981   // in handle_wrong_method which is the backend of the handshake. See
 982   // code in i2c adapters and handle_wrong_method.
 983 
 984   Method*       _callee_target;
 985 
 986   // Used to pass back results to the interpreter or generated code running Java code.
 987   oop           _vm_result;    // oop result is GC-preserved
 988   Metadata*     _vm_result_2;  // non-oop result
 989 
 990   // See ReduceInitialCardMarks: this holds the precise space interval of
 991   // the most recent slow path allocation for which compiled code has
 992   // elided card-marks for performance along the fast-path.
 993   MemRegion     _deferred_card_mark;
 994 
 995   MonitorChunk* _monitor_chunks;                 // Contains the off stack monitors
 996                                                  // allocated during deoptimization
 997                                                  // and by JNI_MonitorEnter/Exit
 998 
 999   // Async. requests support
1000   enum AsyncRequests {
1001     _no_async_condition = 0,
1002     _async_exception,
1003     _async_unsafe_access_error
1004   };
1005   AsyncRequests _special_runtime_exit_condition; // Enum indicating pending async. request
1006   oop           _pending_async_exception;
1007 
1008   // Safepoint support
1009  public:                                         // Expose _thread_state for SafeFetchInt()
1010   volatile JavaThreadState _thread_state;
1011  private:
1012   ThreadSafepointState* _safepoint_state;        // Holds information about a thread during a safepoint
1013   address               _saved_exception_pc;     // Saved pc of instruction where last implicit exception happened
1014 
1015   // JavaThread termination support
1016   enum TerminatedTypes {
1017     _not_terminated = 0xDEAD - 2,
1018     _thread_exiting,                             // JavaThread::exit() has been called for this thread
1019     _thread_terminated,                          // JavaThread is removed from thread list
1020     _vm_exited                                   // JavaThread is still executing native code, but VM is terminated
1021                                                  // only VM_Exit can set _vm_exited
1022   };
1023 
1024   // In general a JavaThread's _terminated field transitions as follows:
1025   //
1026   //   _not_terminated => _thread_exiting => _thread_terminated
1027   //
1028   // _vm_exited is a special value to cover the case of a JavaThread
1029   // executing native code after the VM itself is terminated.
1030   volatile TerminatedTypes _terminated;
1031   // suspend/resume support
1032   volatile bool         _suspend_equivalent;     // Suspend equivalent condition
1033   jint                  _in_deopt_handler;       // count of deoptimization
1034                                                  // handlers thread is in
1035   volatile bool         _doing_unsafe_access;    // Thread may fault due to unsafe access
1036   bool                  _do_not_unlock_if_synchronized;  // Do not unlock the receiver of a synchronized method (since it was
1037                                                          // never locked) when throwing an exception. Used by interpreter only.
1038 
1039   // JNI attach states:
1040   enum JNIAttachStates {
1041     _not_attaching_via_jni = 1,  // thread is not attaching via JNI
1042     _attaching_via_jni,          // thread is attaching via JNI
1043     _attached_via_jni            // thread has attached via JNI
1044   };
1045 
1046   // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
1047   // A native thread that is attaching via JNI starts with a value
1048   // of _attaching_via_jni and transitions to _attached_via_jni.
1049   volatile JNIAttachStates _jni_attach_state;
1050 
1051  public:
1052   // State of the stack guard pages for this thread.
1053   enum StackGuardState {
1054     stack_guard_unused,         // not needed
1055     stack_guard_reserved_disabled,
1056     stack_guard_yellow_reserved_disabled,// disabled (temporarily) after stack overflow
1057     stack_guard_enabled         // enabled
1058   };
1059 
1060  private:
1061 
1062 #if INCLUDE_JVMCI
1063   // The _pending_* fields below are used to communicate extra information
1064   // from an uncommon trap in JVMCI compiled code to the uncommon trap handler.
1065 
1066   // Communicates the DeoptReason and DeoptAction of the uncommon trap
1067   int       _pending_deoptimization;
1068 
1069   // Specifies whether the uncommon trap is to bci 0 of a synchronized method
1070   // before the monitor has been acquired.
1071   bool      _pending_monitorenter;
1072 
1073   // Specifies if the DeoptReason for the last uncommon trap was Reason_transfer_to_interpreter
1074   bool      _pending_transfer_to_interpreter;
1075 
1076   // Guard for re-entrant call to JVMCIRuntime::adjust_comp_level
1077   bool      _adjusting_comp_level;
1078 
1079   // True if in a runtime call from compiled code that will deoptimize
1080   // and re-execute a failed heap allocation in the interpreter.
1081   bool      _in_retryable_allocation;
1082 
1083   // An id of a speculation that JVMCI compiled code can use to further describe and
1084   // uniquely identify the  speculative optimization guarded by the uncommon trap
1085   long       _pending_failed_speculation;
1086 
1087   // These fields are mutually exclusive in terms of live ranges.
1088   union {
1089     // Communicates the pc at which the most recent implicit exception occurred
1090     // from the signal handler to a deoptimization stub.
1091     address   _implicit_exception_pc;
1092 
1093     // Communicates an alternative call target to an i2c stub from a JavaCall .
1094     address   _alternate_call_target;
1095   } _jvmci;
1096 
1097   // Support for high precision, thread sensitive counters in JVMCI compiled code.
1098   jlong*    _jvmci_counters;
1099 
1100  public:
1101   static jlong* _jvmci_old_thread_counters;
1102   static void collect_counters(typeArrayOop array);
1103  private:
1104 #endif // INCLUDE_JVMCI
1105 
1106   StackGuardState  _stack_guard_state;
1107 
1108   // Precompute the limit of the stack as used in stack overflow checks.
1109   // We load it from here to simplify the stack overflow check in assembly.
1110   address          _stack_overflow_limit;
1111   address          _reserved_stack_activation;
1112 
1113   // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
1114   // used to temp. parsing values into and out of the runtime system during exception handling for compiled
1115   // code)
1116   volatile oop     _exception_oop;               // Exception thrown in compiled code
1117   volatile address _exception_pc;                // PC where exception happened
1118   volatile address _exception_handler_pc;        // PC for handler of exception
1119   volatile int     _is_method_handle_return;     // true (== 1) if the current exception PC is a MethodHandle call site.
1120 
1121  private:
1122   // support for JNI critical regions
1123   jint    _jni_active_critical;                  // count of entries into JNI critical region
1124 
1125   // Checked JNI: function name requires exception check
1126   char* _pending_jni_exception_check_fn;
1127 
1128   // For deadlock detection.
1129   int _depth_first_number;
1130 
1131   // JVMTI PopFrame support
1132   // This is set to popframe_pending to signal that top Java frame should be popped immediately
1133   int _popframe_condition;
1134 
1135   // If reallocation of scalar replaced objects fails, we throw OOM
1136   // and during exception propagation, pop the top
1137   // _frames_to_pop_failed_realloc frames, the ones that reference
1138   // failed reallocations.
1139   int _frames_to_pop_failed_realloc;
1140 
1141 #ifndef PRODUCT
1142   int _jmp_ring_index;
1143   struct {
1144     // We use intptr_t instead of address so debugger doesn't try and display strings
1145     intptr_t _target;
1146     intptr_t _instruction;
1147     const char*  _file;
1148     int _line;
1149   }   _jmp_ring[jump_ring_buffer_size];
1150 #endif // PRODUCT
1151 
1152   friend class VMThread;
1153   friend class ThreadWaitTransition;
1154   friend class VM_Exit;
1155 
1156   void initialize();                             // Initialized the instance variables
1157 
1158  public:
1159   // Constructor
1160   JavaThread(bool is_attaching_via_jni = false); // for main thread and JNI attached threads
1161   JavaThread(ThreadFunction entry_point, size_t stack_size = 0);
1162   ~JavaThread();
1163 
1164 #ifdef ASSERT
1165   // verify this JavaThread hasn't be published in the Threads::list yet
1166   void verify_not_published();
1167 #endif
1168 
1169   //JNI functiontable getter/setter for JVMTI jni function table interception API.
1170   void set_jni_functions(struct JNINativeInterface_* functionTable) {
1171     _jni_environment.functions = functionTable;
1172   }
1173   struct JNINativeInterface_* get_jni_functions() {
1174     return (struct JNINativeInterface_ *)_jni_environment.functions;
1175   }
1176 
1177   // This function is called at thread creation to allow
1178   // platform specific thread variables to be initialized.
1179   void cache_global_variables();
1180 
1181   // Executes Shutdown.shutdown()
1182   void invoke_shutdown_hooks();
1183 
1184   // Cleanup on thread exit
1185   enum ExitType {
1186     normal_exit,
1187     jni_detach
1188   };
1189   void exit(bool destroy_vm, ExitType exit_type = normal_exit);
1190 
1191   void cleanup_failed_attach_current_thread();
1192 
1193   // Testers
1194   virtual bool is_Java_thread() const            { return true;  }
1195   virtual bool can_call_java() const             { return true; }
1196 
1197   // Thread chain operations
1198   JavaThread* next() const                       { return _next; }
1199   void set_next(JavaThread* p)                   { _next = p; }
1200 
1201   // Thread oop. threadObj() can be NULL for initial JavaThread
1202   // (or for threads attached via JNI)
1203   oop threadObj() const                          { return _threadObj; }
1204   void set_threadObj(oop p)                      { _threadObj = p; }
1205 
1206   ThreadPriority java_priority() const;          // Read from threadObj()
1207 
1208   // Prepare thread and add to priority queue.  If a priority is
1209   // not specified, use the priority of the thread object. Threads_lock
1210   // must be held while this function is called.
1211   void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
1212 
1213   void set_saved_exception_pc(address pc)        { _saved_exception_pc = pc; }
1214   address saved_exception_pc()                   { return _saved_exception_pc; }
1215 
1216 
1217   ThreadFunction entry_point() const             { return _entry_point; }
1218 
1219   // Allocates a new Java level thread object for this thread. thread_name may be NULL.
1220   void allocate_threadObj(Handle thread_group, const char* thread_name, bool daemon, TRAPS);
1221 
1222   // Last frame anchor routines
1223 
1224   JavaFrameAnchor* frame_anchor(void)            { return &_anchor; }
1225 
1226   // last_Java_sp
1227   bool has_last_Java_frame() const               { return _anchor.has_last_Java_frame(); }
1228   intptr_t* last_Java_sp() const                 { return _anchor.last_Java_sp(); }
1229 
1230   // last_Java_pc
1231 
1232   address last_Java_pc(void)                     { return _anchor.last_Java_pc(); }
1233 
1234   // Safepoint support
1235 #if !(defined(PPC64) || defined(AARCH64))
1236   JavaThreadState thread_state() const           { return _thread_state; }
1237   void set_thread_state(JavaThreadState s)       { _thread_state = s;    }
1238 #else
1239   // Use membars when accessing volatile _thread_state. See
1240   // Threads::create_vm() for size checks.
1241   inline JavaThreadState thread_state() const;
1242   inline void set_thread_state(JavaThreadState s);
1243 #endif
1244   inline ThreadSafepointState* safepoint_state() const;
1245   inline void set_safepoint_state(ThreadSafepointState* state);
1246   inline bool is_at_poll_safepoint();
1247 
1248   // JavaThread termination and lifecycle support:
1249   void smr_delete();
1250   bool on_thread_list() const { return _on_thread_list; }
1251   void set_on_thread_list() { _on_thread_list = true; }
1252 
1253   // thread has called JavaThread::exit() or is terminated
1254   bool is_exiting() const;
1255   // thread is terminated (no longer on the threads list); we compare
1256   // against the two non-terminated values so that a freed JavaThread
1257   // will also be considered terminated.
1258   bool check_is_terminated(TerminatedTypes l_terminated) const {
1259     return l_terminated != _not_terminated && l_terminated != _thread_exiting;
1260   }
1261   bool is_terminated() const;
1262   void set_terminated(TerminatedTypes t);
1263   // special for Threads::remove() which is static:
1264   void set_terminated_value();
1265   void block_if_vm_exited();
1266 
1267   bool doing_unsafe_access()                     { return _doing_unsafe_access; }
1268   void set_doing_unsafe_access(bool val)         { _doing_unsafe_access = val; }
1269 
1270   bool do_not_unlock_if_synchronized()             { return _do_not_unlock_if_synchronized; }
1271   void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
1272 
1273   inline void set_polling_page_release(void* poll_value);
1274   inline void set_polling_page(void* poll_value);
1275   inline volatile void* get_polling_page();
1276 
1277  private:
1278   // Support for thread handshake operations
1279   HandshakeState _handshake;
1280  public:
1281   void set_handshake_operation(HandshakeOperation* op) {
1282     _handshake.set_operation(this, op);
1283   }
1284 
1285   bool has_handshake() const {
1286     return _handshake.has_operation();
1287   }
1288 
1289   void handshake_process_by_self() {
1290     _handshake.process_by_self(this);
1291   }
1292 
1293   void handshake_process_by_vmthread() {
1294     _handshake.process_by_vmthread(this);
1295   }
1296 
1297   // Suspend/resume support for JavaThread
1298  private:
1299   inline void set_ext_suspended();
1300   inline void clear_ext_suspended();
1301 
1302  public:
1303   void java_suspend();
1304   void java_resume();
1305   int  java_suspend_self();
1306 
1307   void check_and_wait_while_suspended() {
1308     assert(JavaThread::current() == this, "sanity check");
1309 
1310     bool do_self_suspend;
1311     do {
1312       // were we externally suspended while we were waiting?
1313       do_self_suspend = handle_special_suspend_equivalent_condition();
1314       if (do_self_suspend) {
1315         // don't surprise the thread that suspended us by returning
1316         java_suspend_self();
1317         set_suspend_equivalent();
1318       }
1319     } while (do_self_suspend);
1320   }
1321   static void check_safepoint_and_suspend_for_native_trans(JavaThread *thread);
1322   // Check for async exception in addition to safepoint and suspend request.
1323   static void check_special_condition_for_native_trans(JavaThread *thread);
1324 
1325   // Same as check_special_condition_for_native_trans but finishes the
1326   // transition into thread_in_Java mode so that it can potentially
1327   // block.
1328   static void check_special_condition_for_native_trans_and_transition(JavaThread *thread);
1329 
1330   bool is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits);
1331   bool is_ext_suspend_completed_with_lock(uint32_t *bits) {
1332     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1333     // Warning: is_ext_suspend_completed() may temporarily drop the
1334     // SR_lock to allow the thread to reach a stable thread state if
1335     // it is currently in a transient thread state.
1336     return is_ext_suspend_completed(false /* !called_by_wait */,
1337                                     SuspendRetryDelay, bits);
1338   }
1339 
1340   // We cannot allow wait_for_ext_suspend_completion() to run forever or
1341   // we could hang. SuspendRetryCount and SuspendRetryDelay are normally
1342   // passed as the count and delay parameters. Experiments with specific
1343   // calls to wait_for_ext_suspend_completion() can be done by passing
1344   // other values in the code. Experiments with all calls can be done
1345   // via the appropriate -XX options.
1346   bool wait_for_ext_suspend_completion(int count, int delay, uint32_t *bits);
1347 
1348   // test for suspend - most (all?) of these should go away
1349   bool is_thread_fully_suspended(bool wait_for_suspend, uint32_t *bits);
1350 
1351   inline void set_external_suspend();
1352   inline void clear_external_suspend();
1353 
1354   inline void set_deopt_suspend();
1355   inline void clear_deopt_suspend();
1356   bool is_deopt_suspend()         { return (_suspend_flags & _deopt_suspend) != 0; }
1357 
1358   bool is_external_suspend() const {
1359     return (_suspend_flags & _external_suspend) != 0;
1360   }
1361   // Whenever a thread transitions from native to vm/java it must suspend
1362   // if external|deopt suspend is present.
1363   bool is_suspend_after_native() const {
1364     return (_suspend_flags & (_external_suspend | _deopt_suspend)) != 0;
1365   }
1366 
1367   // external suspend request is completed
1368   bool is_ext_suspended() const {
1369     return (_suspend_flags & _ext_suspended) != 0;
1370   }
1371 
1372   bool is_external_suspend_with_lock() const {
1373     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1374     return is_external_suspend();
1375   }
1376 
1377   // Special method to handle a pending external suspend request
1378   // when a suspend equivalent condition lifts.
1379   bool handle_special_suspend_equivalent_condition() {
1380     assert(is_suspend_equivalent(),
1381            "should only be called in a suspend equivalence condition");
1382     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1383     bool ret = is_external_suspend();
1384     if (!ret) {
1385       // not about to self-suspend so clear suspend equivalence
1386       clear_suspend_equivalent();
1387     }
1388     // implied else:
1389     // We have a pending external suspend request so we leave the
1390     // suspend_equivalent flag set until java_suspend_self() sets
1391     // the ext_suspended flag and clears the suspend_equivalent
1392     // flag. This insures that wait_for_ext_suspend_completion()
1393     // will return consistent values.
1394     return ret;
1395   }
1396 
1397   // utility methods to see if we are doing some kind of suspension
1398   bool is_being_ext_suspended() const            {
1399     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1400     return is_ext_suspended() || is_external_suspend();
1401   }
1402 
1403   bool is_suspend_equivalent() const             { return _suspend_equivalent; }
1404 
1405   void set_suspend_equivalent()                  { _suspend_equivalent = true; }
1406   void clear_suspend_equivalent()                { _suspend_equivalent = false; }
1407 
1408   // Thread.stop support
1409   void send_thread_stop(oop throwable);
1410   AsyncRequests clear_special_runtime_exit_condition() {
1411     AsyncRequests x = _special_runtime_exit_condition;
1412     _special_runtime_exit_condition = _no_async_condition;
1413     return x;
1414   }
1415 
1416   // Are any async conditions present?
1417   bool has_async_condition() { return (_special_runtime_exit_condition != _no_async_condition); }
1418 
1419   void check_and_handle_async_exceptions(bool check_unsafe_error = true);
1420 
1421   // these next two are also used for self-suspension and async exception support
1422   void handle_special_runtime_exit_condition(bool check_asyncs = true);
1423 
1424   // Return true if JavaThread has an asynchronous condition or
1425   // if external suspension is requested.
1426   bool has_special_runtime_exit_condition() {
1427     // Because we don't use is_external_suspend_with_lock
1428     // it is possible that we won't see an asynchronous external suspend
1429     // request that has just gotten started, i.e., SR_lock grabbed but
1430     // _external_suspend field change either not made yet or not visible
1431     // yet. However, this is okay because the request is asynchronous and
1432     // we will see the new flag value the next time through. It's also
1433     // possible that the external suspend request is dropped after
1434     // we have checked is_external_suspend(), we will recheck its value
1435     // under SR_lock in java_suspend_self().
1436     return (_special_runtime_exit_condition != _no_async_condition) ||
1437             is_external_suspend() || is_trace_suspend();
1438   }
1439 
1440   void set_pending_unsafe_access_error()          { _special_runtime_exit_condition = _async_unsafe_access_error; }
1441 
1442   inline void set_pending_async_exception(oop e);
1443 
1444   // Fast-locking support
1445   bool is_lock_owned(address adr) const;
1446 
1447   // Accessors for vframe array top
1448   // The linked list of vframe arrays are sorted on sp. This means when we
1449   // unpack the head must contain the vframe array to unpack.
1450   void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
1451   vframeArray* vframe_array_head() const         { return _vframe_array_head;  }
1452 
1453   // Side structure for deferring update of java frame locals until deopt occurs
1454   GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred_locals() const { return _deferred_locals_updates; }
1455   void set_deferred_locals(GrowableArray<jvmtiDeferredLocalVariableSet *>* vf) { _deferred_locals_updates = vf; }
1456 
1457   // These only really exist to make debugging deopt problems simpler
1458 
1459   void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
1460   vframeArray* vframe_array_last() const         { return _vframe_array_last;  }
1461 
1462   // The special resourceMark used during deoptimization
1463 
1464   void set_deopt_mark(DeoptResourceMark* value)  { _deopt_mark = value; }
1465   DeoptResourceMark* deopt_mark(void)            { return _deopt_mark; }
1466 
1467   intptr_t* must_deopt_id()                      { return _must_deopt_id; }
1468   void     set_must_deopt_id(intptr_t* id)       { _must_deopt_id = id; }
1469   void     clear_must_deopt_id()                 { _must_deopt_id = NULL; }
1470 
1471   void set_deopt_compiled_method(CompiledMethod* nm)  { _deopt_nmethod = nm; }
1472   CompiledMethod* deopt_compiled_method()        { return _deopt_nmethod; }
1473 
1474   Method*    callee_target() const               { return _callee_target; }
1475   void set_callee_target  (Method* x)          { _callee_target   = x; }
1476 
1477   // Oop results of vm runtime calls
1478   oop  vm_result() const                         { return _vm_result; }
1479   void set_vm_result  (oop x)                    { _vm_result   = x; }
1480 
1481   Metadata*    vm_result_2() const               { return _vm_result_2; }
1482   void set_vm_result_2  (Metadata* x)          { _vm_result_2   = x; }
1483 
1484   MemRegion deferred_card_mark() const           { return _deferred_card_mark; }
1485   void set_deferred_card_mark(MemRegion mr)      { _deferred_card_mark = mr;   }
1486 
1487 #if INCLUDE_JVMCI
1488   int  pending_deoptimization() const             { return _pending_deoptimization; }
1489   long pending_failed_speculation() const         { return _pending_failed_speculation; }
1490   bool adjusting_comp_level() const               { return _adjusting_comp_level; }
1491   void set_adjusting_comp_level(bool b)           { _adjusting_comp_level = b; }
1492   bool has_pending_monitorenter() const           { return _pending_monitorenter; }
1493   void set_pending_monitorenter(bool b)           { _pending_monitorenter = b; }
1494   void set_pending_deoptimization(int reason)     { _pending_deoptimization = reason; }
1495   void set_pending_failed_speculation(long failed_speculation) { _pending_failed_speculation = failed_speculation; }
1496   void set_pending_transfer_to_interpreter(bool b) { _pending_transfer_to_interpreter = b; }
1497   void set_jvmci_alternate_call_target(address a) { assert(_jvmci._alternate_call_target == NULL, "must be"); _jvmci._alternate_call_target = a; }
1498   void set_jvmci_implicit_exception_pc(address a) { assert(_jvmci._implicit_exception_pc == NULL, "must be"); _jvmci._implicit_exception_pc = a; }
1499 
1500   virtual bool in_retryable_allocation() const    { return _in_retryable_allocation; }
1501   void set_in_retryable_allocation(bool b)        { _in_retryable_allocation = b; }
1502 #endif // INCLUDE_JVMCI
1503 
1504   // Exception handling for compiled methods
1505   oop      exception_oop() const                 { return _exception_oop; }
1506   address  exception_pc() const                  { return _exception_pc; }
1507   address  exception_handler_pc() const          { return _exception_handler_pc; }
1508   bool     is_method_handle_return() const       { return _is_method_handle_return == 1; }
1509 
1510   void set_exception_oop(oop o)                  { (void)const_cast<oop&>(_exception_oop = o); }
1511   void set_exception_pc(address a)               { _exception_pc = a; }
1512   void set_exception_handler_pc(address a)       { _exception_handler_pc = a; }
1513   void set_is_method_handle_return(bool value)   { _is_method_handle_return = value ? 1 : 0; }
1514 
1515   void clear_exception_oop_and_pc() {
1516     set_exception_oop(NULL);
1517     set_exception_pc(NULL);
1518   }
1519 
1520   // Stack overflow support
1521   //
1522   //  (small addresses)
1523   //
1524   //  --  <-- stack_end()                   ---
1525   //  |                                      |
1526   //  |  red pages                           |
1527   //  |                                      |
1528   //  --  <-- stack_red_zone_base()          |
1529   //  |                                      |
1530   //  |                                     guard
1531   //  |  yellow pages                       zone
1532   //  |                                      |
1533   //  |                                      |
1534   //  --  <-- stack_yellow_zone_base()       |
1535   //  |                                      |
1536   //  |                                      |
1537   //  |  reserved pages                      |
1538   //  |                                      |
1539   //  --  <-- stack_reserved_zone_base()    ---      ---
1540   //                                                 /|\  shadow     <--  stack_overflow_limit() (somewhere in here)
1541   //                                                  |   zone
1542   //                                                 \|/  size
1543   //  some untouched memory                          ---
1544   //
1545   //
1546   //  --
1547   //  |
1548   //  |  shadow zone
1549   //  |
1550   //  --
1551   //  x    frame n
1552   //  --
1553   //  x    frame n-1
1554   //  x
1555   //  --
1556   //  ...
1557   //
1558   //  --
1559   //  x    frame 0
1560   //  --  <-- stack_base()
1561   //
1562   //  (large addresses)
1563   //
1564 
1565  private:
1566   // These values are derived from flags StackRedPages, StackYellowPages,
1567   // StackReservedPages and StackShadowPages. The zone size is determined
1568   // ergonomically if page_size > 4K.
1569   static size_t _stack_red_zone_size;
1570   static size_t _stack_yellow_zone_size;
1571   static size_t _stack_reserved_zone_size;
1572   static size_t _stack_shadow_zone_size;
1573  public:
1574   inline size_t stack_available(address cur_sp);
1575 
1576   static size_t stack_red_zone_size() {
1577     assert(_stack_red_zone_size > 0, "Don't call this before the field is initialized.");
1578     return _stack_red_zone_size;
1579   }
1580   static void set_stack_red_zone_size(size_t s) {
1581     assert(is_aligned(s, os::vm_page_size()),
1582            "We can not protect if the red zone size is not page aligned.");
1583     assert(_stack_red_zone_size == 0, "This should be called only once.");
1584     _stack_red_zone_size = s;
1585   }
1586   address stack_red_zone_base() {
1587     return (address)(stack_end() + stack_red_zone_size());
1588   }
1589   bool in_stack_red_zone(address a) {
1590     return a <= stack_red_zone_base() && a >= stack_end();
1591   }
1592 
1593   static size_t stack_yellow_zone_size() {
1594     assert(_stack_yellow_zone_size > 0, "Don't call this before the field is initialized.");
1595     return _stack_yellow_zone_size;
1596   }
1597   static void set_stack_yellow_zone_size(size_t s) {
1598     assert(is_aligned(s, os::vm_page_size()),
1599            "We can not protect if the yellow zone size is not page aligned.");
1600     assert(_stack_yellow_zone_size == 0, "This should be called only once.");
1601     _stack_yellow_zone_size = s;
1602   }
1603 
1604   static size_t stack_reserved_zone_size() {
1605     // _stack_reserved_zone_size may be 0. This indicates the feature is off.
1606     return _stack_reserved_zone_size;
1607   }
1608   static void set_stack_reserved_zone_size(size_t s) {
1609     assert(is_aligned(s, os::vm_page_size()),
1610            "We can not protect if the reserved zone size is not page aligned.");
1611     assert(_stack_reserved_zone_size == 0, "This should be called only once.");
1612     _stack_reserved_zone_size = s;
1613   }
1614   address stack_reserved_zone_base() {
1615     return (address)(stack_end() +
1616                      (stack_red_zone_size() + stack_yellow_zone_size() + stack_reserved_zone_size()));
1617   }
1618   bool in_stack_reserved_zone(address a) {
1619     return (a <= stack_reserved_zone_base()) &&
1620            (a >= (address)((intptr_t)stack_reserved_zone_base() - stack_reserved_zone_size()));
1621   }
1622 
1623   static size_t stack_yellow_reserved_zone_size() {
1624     return _stack_yellow_zone_size + _stack_reserved_zone_size;
1625   }
1626   bool in_stack_yellow_reserved_zone(address a) {
1627     return (a <= stack_reserved_zone_base()) && (a >= stack_red_zone_base());
1628   }
1629 
1630   // Size of red + yellow + reserved zones.
1631   static size_t stack_guard_zone_size() {
1632     return stack_red_zone_size() + stack_yellow_reserved_zone_size();
1633   }
1634 
1635   static size_t stack_shadow_zone_size() {
1636     assert(_stack_shadow_zone_size > 0, "Don't call this before the field is initialized.");
1637     return _stack_shadow_zone_size;
1638   }
1639   static void set_stack_shadow_zone_size(size_t s) {
1640     // The shadow area is not allocated or protected, so
1641     // it needs not be page aligned.
1642     // But the stack bang currently assumes that it is a
1643     // multiple of page size. This guarantees that the bang
1644     // loop touches all pages in the shadow zone.
1645     // This can be guaranteed differently, as well.  E.g., if
1646     // the page size is a multiple of 4K, banging in 4K steps
1647     // suffices to touch all pages. (Some pages are banged
1648     // several times, though.)
1649     assert(is_aligned(s, os::vm_page_size()),
1650            "Stack bang assumes multiple of page size.");
1651     assert(_stack_shadow_zone_size == 0, "This should be called only once.");
1652     _stack_shadow_zone_size = s;
1653   }
1654 
1655   void create_stack_guard_pages();
1656   void remove_stack_guard_pages();
1657 
1658   void enable_stack_reserved_zone();
1659   void disable_stack_reserved_zone();
1660   void enable_stack_yellow_reserved_zone();
1661   void disable_stack_yellow_reserved_zone();
1662   void enable_stack_red_zone();
1663   void disable_stack_red_zone();
1664 
1665   inline bool stack_guard_zone_unused();
1666   inline bool stack_yellow_reserved_zone_disabled();
1667   inline bool stack_reserved_zone_disabled();
1668   inline bool stack_guards_enabled();
1669 
1670   address reserved_stack_activation() const { return _reserved_stack_activation; }
1671   void set_reserved_stack_activation(address addr) {
1672     assert(_reserved_stack_activation == stack_base()
1673             || _reserved_stack_activation == NULL
1674             || addr == stack_base(), "Must not be set twice");
1675     _reserved_stack_activation = addr;
1676   }
1677 
1678   // Attempt to reguard the stack after a stack overflow may have occurred.
1679   // Returns true if (a) guard pages are not needed on this thread, (b) the
1680   // pages are already guarded, or (c) the pages were successfully reguarded.
1681   // Returns false if there is not enough stack space to reguard the pages, in
1682   // which case the caller should unwind a frame and try again.  The argument
1683   // should be the caller's (approximate) sp.
1684   bool reguard_stack(address cur_sp);
1685   // Similar to above but see if current stackpoint is out of the guard area
1686   // and reguard if possible.
1687   bool reguard_stack(void);
1688 
1689   address stack_overflow_limit() { return _stack_overflow_limit; }
1690   void set_stack_overflow_limit() {
1691     _stack_overflow_limit =
1692       stack_end() + MAX2(JavaThread::stack_guard_zone_size(), JavaThread::stack_shadow_zone_size());
1693   }
1694 
1695   // Misc. accessors/mutators
1696   void set_do_not_unlock(void)                   { _do_not_unlock_if_synchronized = true; }
1697   void clr_do_not_unlock(void)                   { _do_not_unlock_if_synchronized = false; }
1698   bool do_not_unlock(void)                       { return _do_not_unlock_if_synchronized; }
1699 
1700 #ifndef PRODUCT
1701   void record_jump(address target, address instr, const char* file, int line);
1702 #endif // PRODUCT
1703 
1704   // For assembly stub generation
1705   static ByteSize threadObj_offset()             { return byte_offset_of(JavaThread, _threadObj); }
1706 #ifndef PRODUCT
1707   static ByteSize jmp_ring_index_offset()        { return byte_offset_of(JavaThread, _jmp_ring_index); }
1708   static ByteSize jmp_ring_offset()              { return byte_offset_of(JavaThread, _jmp_ring); }
1709 #endif // PRODUCT
1710   static ByteSize jni_environment_offset()       { return byte_offset_of(JavaThread, _jni_environment); }
1711   static ByteSize pending_jni_exception_check_fn_offset() {
1712     return byte_offset_of(JavaThread, _pending_jni_exception_check_fn);
1713   }
1714   static ByteSize last_Java_sp_offset() {
1715     return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
1716   }
1717   static ByteSize last_Java_pc_offset() {
1718     return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
1719   }
1720   static ByteSize frame_anchor_offset() {
1721     return byte_offset_of(JavaThread, _anchor);
1722   }
1723   static ByteSize callee_target_offset()         { return byte_offset_of(JavaThread, _callee_target); }
1724   static ByteSize vm_result_offset()             { return byte_offset_of(JavaThread, _vm_result); }
1725   static ByteSize vm_result_2_offset()           { return byte_offset_of(JavaThread, _vm_result_2); }
1726   static ByteSize thread_state_offset()          { return byte_offset_of(JavaThread, _thread_state); }
1727   static ByteSize saved_exception_pc_offset()    { return byte_offset_of(JavaThread, _saved_exception_pc); }
1728   static ByteSize osthread_offset()              { return byte_offset_of(JavaThread, _osthread); }
1729 #if INCLUDE_JVMCI
1730   static ByteSize pending_deoptimization_offset() { return byte_offset_of(JavaThread, _pending_deoptimization); }
1731   static ByteSize pending_monitorenter_offset()  { return byte_offset_of(JavaThread, _pending_monitorenter); }
1732   static ByteSize pending_failed_speculation_offset() { return byte_offset_of(JavaThread, _pending_failed_speculation); }
1733   static ByteSize jvmci_alternate_call_target_offset() { return byte_offset_of(JavaThread, _jvmci._alternate_call_target); }
1734   static ByteSize jvmci_implicit_exception_pc_offset() { return byte_offset_of(JavaThread, _jvmci._implicit_exception_pc); }
1735   static ByteSize jvmci_counters_offset()        { return byte_offset_of(JavaThread, _jvmci_counters); }
1736 #endif // INCLUDE_JVMCI
1737   static ByteSize exception_oop_offset()         { return byte_offset_of(JavaThread, _exception_oop); }
1738   static ByteSize exception_pc_offset()          { return byte_offset_of(JavaThread, _exception_pc); }
1739   static ByteSize exception_handler_pc_offset()  { return byte_offset_of(JavaThread, _exception_handler_pc); }
1740   static ByteSize stack_overflow_limit_offset()  { return byte_offset_of(JavaThread, _stack_overflow_limit); }
1741   static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); }
1742   static ByteSize stack_guard_state_offset()     { return byte_offset_of(JavaThread, _stack_guard_state); }
1743   static ByteSize reserved_stack_activation_offset() { return byte_offset_of(JavaThread, _reserved_stack_activation); }
1744   static ByteSize suspend_flags_offset()         { return byte_offset_of(JavaThread, _suspend_flags); }
1745 
1746   static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
1747   static ByteSize should_post_on_exceptions_flag_offset() {
1748     return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
1749   }
1750 
1751   // Returns the jni environment for this thread
1752   JNIEnv* jni_environment()                      { return &_jni_environment; }
1753 
1754   static JavaThread* thread_from_jni_environment(JNIEnv* env) {
1755     JavaThread *thread_from_jni_env = (JavaThread*)((intptr_t)env - in_bytes(jni_environment_offset()));
1756     // Only return NULL if thread is off the thread list; starting to
1757     // exit should not return NULL.
1758     if (thread_from_jni_env->is_terminated()) {
1759       thread_from_jni_env->block_if_vm_exited();
1760       return NULL;
1761     } else {
1762       return thread_from_jni_env;
1763     }
1764   }
1765 
1766   // JNI critical regions. These can nest.
1767   bool in_critical()    { return _jni_active_critical > 0; }
1768   bool in_last_critical()  { return _jni_active_critical == 1; }
1769   inline void enter_critical();
1770   void exit_critical() {
1771     assert(Thread::current() == this, "this must be current thread");
1772     _jni_active_critical--;
1773     assert(_jni_active_critical >= 0, "JNI critical nesting problem?");
1774   }
1775 
1776   // Checked JNI: is the programmer required to check for exceptions, if so specify
1777   // which function name. Returning to a Java frame should implicitly clear the
1778   // pending check, this is done for Native->Java transitions (i.e. user JNI code).
1779   // VM->Java transistions are not cleared, it is expected that JNI code enclosed
1780   // within ThreadToNativeFromVM makes proper exception checks (i.e. VM internal).
1781   bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != NULL; }
1782   void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = NULL; }
1783   const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; }
1784   void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; }
1785 
1786   // For deadlock detection
1787   int depth_first_number() { return _depth_first_number; }
1788   void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
1789 
1790  private:
1791   void set_monitor_chunks(MonitorChunk* monitor_chunks) { _monitor_chunks = monitor_chunks; }
1792 
1793  public:
1794   MonitorChunk* monitor_chunks() const           { return _monitor_chunks; }
1795   void add_monitor_chunk(MonitorChunk* chunk);
1796   void remove_monitor_chunk(MonitorChunk* chunk);
1797   bool in_deopt_handler() const                  { return _in_deopt_handler > 0; }
1798   void inc_in_deopt_handler()                    { _in_deopt_handler++; }
1799   void dec_in_deopt_handler() {
1800     assert(_in_deopt_handler > 0, "mismatched deopt nesting");
1801     if (_in_deopt_handler > 0) { // robustness
1802       _in_deopt_handler--;
1803     }
1804   }
1805 
1806  private:
1807   void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
1808 
1809  public:
1810 
1811   // Frame iteration; calls the function f for all frames on the stack
1812   void frames_do(void f(frame*, const RegisterMap*));
1813 
1814   // Memory operations
1815   void oops_do(OopClosure* f, CodeBlobClosure* cf);
1816 
1817   // Sweeper operations
1818   virtual void nmethods_do(CodeBlobClosure* cf);
1819 
1820   // RedefineClasses Support
1821   void metadata_do(void f(Metadata*));
1822 
1823   // Misc. operations
1824   char* name() const { return (char*)get_thread_name(); }
1825   void print_on(outputStream* st, bool print_extended_info) const;
1826   void print_on(outputStream* st) const { print_on(st, false); }
1827   void print_value();
1828   void print_thread_state_on(outputStream*) const      PRODUCT_RETURN;
1829   void print_thread_state() const                      PRODUCT_RETURN;
1830   void print_on_error(outputStream* st, char* buf, int buflen) const;
1831   void print_name_on_error(outputStream* st, char* buf, int buflen) const;
1832   void verify();
1833   const char* get_thread_name() const;
1834  private:
1835   // factor out low-level mechanics for use in both normal and error cases
1836   const char* get_thread_name_string(char* buf = NULL, int buflen = 0) const;
1837  public:
1838   const char* get_threadgroup_name() const;
1839   const char* get_parent_name() const;
1840 
1841   // Accessing frames
1842   frame last_frame() {
1843     _anchor.make_walkable(this);
1844     return pd_last_frame();
1845   }
1846   javaVFrame* last_java_vframe(RegisterMap* reg_map);
1847 
1848   // Returns method at 'depth' java or native frames down the stack
1849   // Used for security checks
1850   Klass* security_get_caller_class(int depth);
1851 
1852   // Print stack trace in external format
1853   void print_stack_on(outputStream* st);
1854   void print_stack() { print_stack_on(tty); }
1855 
1856   // Print stack traces in various internal formats
1857   void trace_stack()                             PRODUCT_RETURN;
1858   void trace_stack_from(vframe* start_vf)        PRODUCT_RETURN;
1859   void trace_frames()                            PRODUCT_RETURN;
1860   void trace_oops()                              PRODUCT_RETURN;
1861 
1862   // Print an annotated view of the stack frames
1863   void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN;
1864   void validate_frame_layout() {
1865     print_frame_layout(0, true);
1866   }
1867 
1868   // Returns the number of stack frames on the stack
1869   int depth() const;
1870 
1871   // Function for testing deoptimization
1872   void deoptimize();
1873   void make_zombies();
1874 
1875   void deoptimized_wrt_marked_nmethods();
1876 
1877  public:
1878   // Returns the running thread as a JavaThread
1879   static inline JavaThread* current();
1880 
1881   // Returns the active Java thread.  Do not use this if you know you are calling
1882   // from a JavaThread, as it's slower than JavaThread::current.  If called from
1883   // the VMThread, it also returns the JavaThread that instigated the VMThread's
1884   // operation.  You may not want that either.
1885   static JavaThread* active();
1886 
1887   inline CompilerThread* as_CompilerThread();
1888 
1889  public:
1890   virtual void run();
1891   void thread_main_inner();
1892 
1893  private:
1894   GrowableArray<oop>* _array_for_gc;
1895  public:
1896 
1897   void register_array_for_gc(GrowableArray<oop>* array) { _array_for_gc = array; }
1898 
1899  public:
1900   // Thread local information maintained by JVMTI.
1901   void set_jvmti_thread_state(JvmtiThreadState *value)                           { _jvmti_thread_state = value; }
1902   // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1903   // getter is used to get this JavaThread's JvmtiThreadState if it has
1904   // one which means NULL can be returned. JvmtiThreadState::state_for()
1905   // is used to get the specified JavaThread's JvmtiThreadState if it has
1906   // one or it allocates a new JvmtiThreadState for the JavaThread and
1907   // returns it. JvmtiThreadState::state_for() will return NULL only if
1908   // the specified JavaThread is exiting.
1909   JvmtiThreadState *jvmti_thread_state() const                                   { return _jvmti_thread_state; }
1910   static ByteSize jvmti_thread_state_offset()                                    { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1911 
1912   // JVMTI PopFrame support
1913   // Setting and clearing popframe_condition
1914   // All of these enumerated values are bits. popframe_pending
1915   // indicates that a PopFrame() has been requested and not yet been
1916   // completed. popframe_processing indicates that that PopFrame() is in
1917   // the process of being completed. popframe_force_deopt_reexecution_bit
1918   // indicates that special handling is required when returning to a
1919   // deoptimized caller.
1920   enum PopCondition {
1921     popframe_inactive                      = 0x00,
1922     popframe_pending_bit                   = 0x01,
1923     popframe_processing_bit                = 0x02,
1924     popframe_force_deopt_reexecution_bit   = 0x04
1925   };
1926   PopCondition popframe_condition()                   { return (PopCondition) _popframe_condition; }
1927   void set_popframe_condition(PopCondition c)         { _popframe_condition = c; }
1928   void set_popframe_condition_bit(PopCondition c)     { _popframe_condition |= c; }
1929   void clear_popframe_condition()                     { _popframe_condition = popframe_inactive; }
1930   static ByteSize popframe_condition_offset()         { return byte_offset_of(JavaThread, _popframe_condition); }
1931   bool has_pending_popframe()                         { return (popframe_condition() & popframe_pending_bit) != 0; }
1932   bool popframe_forcing_deopt_reexecution()           { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
1933   void clear_popframe_forcing_deopt_reexecution()     { _popframe_condition &= ~popframe_force_deopt_reexecution_bit; }
1934 #ifdef CC_INTERP
1935   bool pop_frame_pending(void)                        { return ((_popframe_condition & popframe_pending_bit) != 0); }
1936   void clr_pop_frame_pending(void)                    { _popframe_condition = popframe_inactive; }
1937   bool pop_frame_in_process(void)                     { return ((_popframe_condition & popframe_processing_bit) != 0); }
1938   void set_pop_frame_in_process(void)                 { _popframe_condition |= popframe_processing_bit; }
1939   void clr_pop_frame_in_process(void)                 { _popframe_condition &= ~popframe_processing_bit; }
1940 #endif
1941 
1942   int frames_to_pop_failed_realloc() const            { return _frames_to_pop_failed_realloc; }
1943   void set_frames_to_pop_failed_realloc(int nb)       { _frames_to_pop_failed_realloc = nb; }
1944   void dec_frames_to_pop_failed_realloc()             { _frames_to_pop_failed_realloc--; }
1945 
1946  private:
1947   // Saved incoming arguments to popped frame.
1948   // Used only when popped interpreted frame returns to deoptimized frame.
1949   void*    _popframe_preserved_args;
1950   int      _popframe_preserved_args_size;
1951 
1952  public:
1953   void  popframe_preserve_args(ByteSize size_in_bytes, void* start);
1954   void* popframe_preserved_args();
1955   ByteSize popframe_preserved_args_size();
1956   WordSize popframe_preserved_args_size_in_words();
1957   void  popframe_free_preserved_args();
1958 
1959 
1960  private:
1961   JvmtiThreadState *_jvmti_thread_state;
1962 
1963   // Used by the interpreter in fullspeed mode for frame pop, method
1964   // entry, method exit and single stepping support. This field is
1965   // only set to non-zero by the VM_EnterInterpOnlyMode VM operation.
1966   // It can be set to zero asynchronously (i.e., without a VM operation
1967   // or a lock) so we have to be very careful.
1968   int               _interp_only_mode;
1969 
1970  public:
1971   // used by the interpreter for fullspeed debugging support (see above)
1972   static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
1973   bool is_interp_only_mode()                { return (_interp_only_mode != 0); }
1974   int get_interp_only_mode()                { return _interp_only_mode; }
1975   void increment_interp_only_mode()         { ++_interp_only_mode; }
1976   void decrement_interp_only_mode()         { --_interp_only_mode; }
1977 
1978   // support for cached flag that indicates whether exceptions need to be posted for this thread
1979   // if this is false, we can avoid deoptimizing when events are thrown
1980   // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
1981  private:
1982   int    _should_post_on_exceptions_flag;
1983 
1984  public:
1985   int   should_post_on_exceptions_flag()  { return _should_post_on_exceptions_flag; }
1986   void  set_should_post_on_exceptions_flag(int val)  { _should_post_on_exceptions_flag = val; }
1987 
1988  private:
1989   ThreadStatistics *_thread_stat;
1990 
1991  public:
1992   ThreadStatistics* get_thread_stat() const    { return _thread_stat; }
1993 
1994   // Return a blocker object for which this thread is blocked parking.
1995   oop current_park_blocker();
1996 
1997  private:
1998   static size_t _stack_size_at_create;
1999 
2000  public:
2001   static inline size_t stack_size_at_create(void) {
2002     return _stack_size_at_create;
2003   }
2004   static inline void set_stack_size_at_create(size_t value) {
2005     _stack_size_at_create = value;
2006   }
2007 
2008   // Machine dependent stuff
2009 #include OS_CPU_HEADER(thread)
2010 
2011  public:
2012   void set_blocked_on_compilation(bool value) {
2013     _blocked_on_compilation = value;
2014   }
2015 
2016   bool blocked_on_compilation() {
2017     return _blocked_on_compilation;
2018   }
2019  protected:
2020   bool         _blocked_on_compilation;
2021 
2022 
2023   // JSR166 per-thread parker
2024  private:
2025   Parker*    _parker;
2026  public:
2027   Parker*     parker() { return _parker; }
2028 
2029   // Biased locking support
2030  private:
2031   GrowableArray<MonitorInfo*>* _cached_monitor_info;
2032  public:
2033   GrowableArray<MonitorInfo*>* cached_monitor_info() { return _cached_monitor_info; }
2034   void set_cached_monitor_info(GrowableArray<MonitorInfo*>* info) { _cached_monitor_info = info; }
2035 
2036   // clearing/querying jni attach status
2037   bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; }
2038   bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
2039   inline void set_done_attaching_via_jni();
2040 };
2041 
2042 // Inline implementation of JavaThread::current
2043 inline JavaThread* JavaThread::current() {
2044   Thread* thread = Thread::current();
2045   assert(thread->is_Java_thread(), "just checking");
2046   return (JavaThread*)thread;
2047 }
2048 
2049 inline CompilerThread* JavaThread::as_CompilerThread() {
2050   assert(is_Compiler_thread(), "just checking");
2051   return (CompilerThread*)this;
2052 }
2053 
2054 // Dedicated thread to sweep the code cache
2055 class CodeCacheSweeperThread : public JavaThread {
2056   CompiledMethod*       _scanned_compiled_method; // nmethod being scanned by the sweeper
2057  public:
2058   CodeCacheSweeperThread();
2059   // Track the nmethod currently being scanned by the sweeper
2060   void set_scanned_compiled_method(CompiledMethod* cm) {
2061     assert(_scanned_compiled_method == NULL || cm == NULL, "should reset to NULL before writing a new value");
2062     _scanned_compiled_method = cm;
2063   }
2064 
2065   // Hide sweeper thread from external view.
2066   bool is_hidden_from_external_view() const { return true; }
2067 
2068   bool is_Code_cache_sweeper_thread() const { return true; }
2069 
2070   // Prevent GC from unloading _scanned_compiled_method
2071   void oops_do(OopClosure* f, CodeBlobClosure* cf);
2072   void nmethods_do(CodeBlobClosure* cf);
2073 };
2074 
2075 // A thread used for Compilation.
2076 class CompilerThread : public JavaThread {
2077   friend class VMStructs;
2078  private:
2079   CompilerCounters* _counters;
2080 
2081   ciEnv*                _env;
2082   CompileLog*           _log;
2083   CompileTask* volatile _task;  // print_threads_compiling can read this concurrently.
2084   CompileQueue*         _queue;
2085   BufferBlob*           _buffer_blob;
2086 
2087   AbstractCompiler*     _compiler;
2088   TimeStamp             _idle_time;
2089 
2090  public:
2091 
2092   static CompilerThread* current();
2093 
2094   CompilerThread(CompileQueue* queue, CompilerCounters* counters);
2095   ~CompilerThread();
2096 
2097   bool is_Compiler_thread() const                { return true; }
2098 
2099   virtual bool can_call_java() const;
2100 
2101   // Hide native compiler threads from external view.
2102   bool is_hidden_from_external_view() const      { return !can_call_java(); }
2103 
2104   void set_compiler(AbstractCompiler* c)         { _compiler = c; }
2105   AbstractCompiler* compiler() const             { return _compiler; }
2106 
2107   CompileQueue* queue()        const             { return _queue; }
2108   CompilerCounters* counters() const             { return _counters; }
2109 
2110   // Get/set the thread's compilation environment.
2111   ciEnv*        env()                            { return _env; }
2112   void          set_env(ciEnv* env)              { _env = env; }
2113 
2114   BufferBlob*   get_buffer_blob() const          { return _buffer_blob; }
2115   void          set_buffer_blob(BufferBlob* b)   { _buffer_blob = b; }
2116 
2117   // Get/set the thread's logging information
2118   CompileLog*   log()                            { return _log; }
2119   void          init_log(CompileLog* log) {
2120     // Set once, for good.
2121     assert(_log == NULL, "set only once");
2122     _log = log;
2123   }
2124 
2125   void start_idle_timer()                        { _idle_time.update(); }
2126   jlong idle_time_millis() {
2127     return TimeHelper::counter_to_millis(_idle_time.ticks_since_update());
2128   }
2129 
2130 #ifndef PRODUCT
2131  private:
2132   IdealGraphPrinter *_ideal_graph_printer;
2133  public:
2134   IdealGraphPrinter *ideal_graph_printer()           { return _ideal_graph_printer; }
2135   void set_ideal_graph_printer(IdealGraphPrinter *n) { _ideal_graph_printer = n; }
2136 #endif
2137 
2138   // Get/set the thread's current task
2139   CompileTask* task()                      { return _task; }
2140   void         set_task(CompileTask* task) { _task = task; }
2141 };
2142 
2143 inline CompilerThread* CompilerThread::current() {
2144   return JavaThread::current()->as_CompilerThread();
2145 }
2146 
2147 // The active thread queue. It also keeps track of the current used
2148 // thread priorities.
2149 class Threads: AllStatic {
2150   friend class VMStructs;
2151  private:
2152   static JavaThread* _thread_list;
2153   static int         _number_of_threads;
2154   static int         _number_of_non_daemon_threads;
2155   static int         _return_code;
2156   static int         _thread_claim_parity;
2157 #ifdef ASSERT
2158   static bool        _vm_complete;
2159 #endif
2160 
2161   static void initialize_java_lang_classes(JavaThread* main_thread, TRAPS);
2162   static void initialize_jsr292_core_classes(TRAPS);
2163 
2164  public:
2165   // Thread management
2166   // force_daemon is a concession to JNI, where we may need to add a
2167   // thread to the thread list before allocating its thread object
2168   static void add(JavaThread* p, bool force_daemon = false);
2169   static void remove(JavaThread* p);
2170   static void non_java_threads_do(ThreadClosure* tc);
2171   static void java_threads_do(ThreadClosure* tc);
2172   static void java_threads_and_vm_thread_do(ThreadClosure* tc);
2173   static void threads_do(ThreadClosure* tc);
2174   static void possibly_parallel_threads_do(bool is_par, ThreadClosure* tc);
2175 
2176   // Initializes the vm and creates the vm thread
2177   static jint create_vm(JavaVMInitArgs* args, bool* canTryAgain);
2178   static void convert_vm_init_libraries_to_agents();
2179   static void create_vm_init_libraries();
2180   static void create_vm_init_agents();
2181   static void shutdown_vm_agents();
2182   static bool destroy_vm();
2183   // Supported VM versions via JNI
2184   // Includes JNI_VERSION_1_1
2185   static jboolean is_supported_jni_version_including_1_1(jint version);
2186   // Does not include JNI_VERSION_1_1
2187   static jboolean is_supported_jni_version(jint version);
2188 
2189   // The "thread claim parity" provides a way for threads to be claimed
2190   // by parallel worker tasks.
2191   //
2192   // Each thread contains a a "parity" field. A task will claim the
2193   // thread only if its parity field is the same as the global parity,
2194   // which is updated by calling change_thread_claim_parity().
2195   //
2196   // For this to work change_thread_claim_parity() needs to be called
2197   // exactly once in sequential code before starting parallel tasks
2198   // that should claim threads.
2199   //
2200   // New threads get their parity set to 0 and change_thread_claim_parity()
2201   // never set the global parity to 0.
2202   static int thread_claim_parity() { return _thread_claim_parity; }
2203   static void change_thread_claim_parity();
2204   static void assert_all_threads_claimed() NOT_DEBUG_RETURN;
2205 
2206   // Apply "f->do_oop" to all root oops in all threads.
2207   // This version may only be called by sequential code.
2208   static void oops_do(OopClosure* f, CodeBlobClosure* cf);
2209   // This version may be called by sequential or parallel code.
2210   static void possibly_parallel_oops_do(bool is_par, OopClosure* f, CodeBlobClosure* cf);
2211 
2212   // Apply "f->do_oop" to roots in all threads that
2213   // are part of compiled frames
2214   static void compiled_frame_oops_do(OopClosure* f, CodeBlobClosure* cf);
2215 
2216   static void convert_hcode_pointers();
2217   static void restore_hcode_pointers();
2218 
2219   // Sweeper
2220   static void nmethods_do(CodeBlobClosure* cf);
2221 
2222   // RedefineClasses support
2223   static void metadata_do(void f(Metadata*));
2224   static void metadata_handles_do(void f(Metadata*));
2225 
2226 #ifdef ASSERT
2227   static bool is_vm_complete() { return _vm_complete; }
2228 #endif // ASSERT
2229 
2230   // Verification
2231   static void verify();
2232   static void print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks, bool print_extended_info);
2233   static void print(bool print_stacks, bool internal_format) {
2234     // this function is only used by debug.cpp
2235     print_on(tty, print_stacks, internal_format, false /* no concurrent lock printed */, false /* simple format */);
2236   }
2237   static void print_on_error(outputStream* st, Thread* current, char* buf, int buflen);
2238   static void print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
2239                              int buflen, bool* found_current);
2240   static void print_threads_compiling(outputStream* st, char* buf, int buflen);
2241 
2242   // Get Java threads that are waiting to enter a monitor.
2243   static GrowableArray<JavaThread*>* get_pending_threads(ThreadsList * t_list,
2244                                                          int count, address monitor);
2245 
2246   // Get owning Java thread from the monitor's owner field.
2247   static JavaThread *owning_thread_from_monitor_owner(ThreadsList * t_list,
2248                                                       address owner);
2249 
2250   // Number of threads on the active threads list
2251   static int number_of_threads()                 { return _number_of_threads; }
2252   // Number of non-daemon threads on the active threads list
2253   static int number_of_non_daemon_threads()      { return _number_of_non_daemon_threads; }
2254 
2255   // Deoptimizes all frames tied to marked nmethods
2256   static void deoptimized_wrt_marked_nmethods();
2257 };
2258 
2259 
2260 // Thread iterator
2261 class ThreadClosure: public StackObj {
2262  public:
2263   virtual void do_thread(Thread* thread) = 0;
2264 };
2265 
2266 class SignalHandlerMark: public StackObj {
2267  private:
2268   Thread* _thread;
2269  public:
2270   SignalHandlerMark(Thread* t) {
2271     _thread = t;
2272     if (_thread) _thread->enter_signal_handler();
2273   }
2274   ~SignalHandlerMark() {
2275     if (_thread) _thread->leave_signal_handler();
2276     _thread = NULL;
2277   }
2278 };
2279 
2280 
2281 #endif // SHARE_VM_RUNTIME_THREAD_HPP