rev 50464 : Thread Dump Extension (memory allocation)

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