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/threadLocalAllocBuffer.hpp"
  30 #include "memory/allocation.hpp"
  31 #include "oops/oop.hpp"
  32 #include "prims/jvmtiExport.hpp"
  33 #include "runtime/frame.hpp"
  34 #include "runtime/handshake.hpp"
  35 #include "runtime/javaFrameAnchor.hpp"
  36 #include "runtime/jniHandles.hpp"
  37 #include "runtime/mutexLocker.hpp"
  38 #include "runtime/os.hpp"
  39 #include "runtime/osThread.hpp"
  40 #include "runtime/park.hpp"
  41 #include "runtime/safepoint.hpp"
  42 #include "runtime/stubRoutines.hpp"
  43 #include "runtime/threadLocalStorage.hpp"
  44 #include "runtime/thread_ext.hpp"
  45 #include "runtime/unhandledOops.hpp"
  46 #include "trace/traceBackend.hpp"
  47 #include "trace/traceMacros.hpp"
  48 #include "utilities/align.hpp"
  49 #include "utilities/exceptions.hpp"
  50 #include "utilities/macros.hpp"
  51 #if INCLUDE_ALL_GCS
  52 #include "gc/g1/dirtyCardQueue.hpp"
  53 #include "gc/g1/satbMarkQueue.hpp"
  54 #endif // INCLUDE_ALL_GCS
  55 #ifdef ZERO
  56 # include "stack_zero.hpp"
  57 #endif
  58 
  59 class ThreadSafepointState;
  60 class ThreadsList;
  61 class ThreadsSMRSupport;
  62 class NestedThreadsList;
  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   // Exception handling
 117   // (Note: _pending_exception and friends are in ThreadShadow)
 118   //oop       _pending_exception;                // pending exception for current thread
 119   // const char* _exception_file;                   // file information for exception (debugging only)
 120   // int         _exception_line;                   // line information for exception (debugging only)
 121  protected:
 122   // Support for forcing alignment of thread objects for biased locking
 123   void*       _real_malloc_address;
 124 
 125   // JavaThread lifecycle support:
 126   friend class ScanHazardPtrGatherProtectedThreadsClosure;  // for cmpxchg_threads_hazard_ptr(), get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
 127   friend class ScanHazardPtrGatherThreadsListClosure;  // for get_nested_threads_hazard_ptr(), get_threads_hazard_ptr(), untag_hazard_ptr() access
 128   friend class ScanHazardPtrPrintMatchingThreadsClosure;  // for get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
 129   friend class ThreadsListSetter;  // for get_threads_hazard_ptr() access
 130   friend class ThreadsSMRSupport;  // for get_threads_hazard_ptr() access
 131 
 132   ThreadsList* volatile _threads_hazard_ptr;
 133   ThreadsList*          cmpxchg_threads_hazard_ptr(ThreadsList* exchange_value, ThreadsList* compare_value);
 134   ThreadsList*          get_threads_hazard_ptr();
 135   void                  set_threads_hazard_ptr(ThreadsList* new_list);
 136   static bool           is_hazard_ptr_tagged(ThreadsList* list) {
 137     return (intptr_t(list) & intptr_t(1)) == intptr_t(1);
 138   }
 139   static ThreadsList*   tag_hazard_ptr(ThreadsList* list) {
 140     return (ThreadsList*)(intptr_t(list) | intptr_t(1));
 141   }
 142   static ThreadsList*   untag_hazard_ptr(ThreadsList* list) {
 143     return (ThreadsList*)(intptr_t(list) & ~intptr_t(1));
 144   }
 145   NestedThreadsList* _nested_threads_hazard_ptr;
 146   NestedThreadsList* get_nested_threads_hazard_ptr() {
 147     return _nested_threads_hazard_ptr;
 148   }
 149   void set_nested_threads_hazard_ptr(NestedThreadsList* value) {
 150     assert(Threads_lock->owned_by_self(),
 151            "must own Threads_lock for _nested_threads_hazard_ptr to be valid.");
 152     _nested_threads_hazard_ptr = value;
 153   }
 154   // This field is enabled via -XX:+EnableThreadSMRStatistics:
 155   uint _nested_threads_hazard_ptr_cnt;
 156   void dec_nested_threads_hazard_ptr_cnt() {
 157     assert(_nested_threads_hazard_ptr_cnt != 0, "mismatched {dec,inc}_nested_threads_hazard_ptr_cnt()");
 158     _nested_threads_hazard_ptr_cnt--;
 159   }
 160   void inc_nested_threads_hazard_ptr_cnt() {
 161     _nested_threads_hazard_ptr_cnt++;
 162   }
 163   uint nested_threads_hazard_ptr_cnt() {
 164     return _nested_threads_hazard_ptr_cnt;
 165   }
 166 
 167  public:
 168   void* operator new(size_t size) throw() { return allocate(size, true); }
 169   void* operator new(size_t size, const std::nothrow_t& nothrow_constant) throw() {
 170     return allocate(size, false); }
 171   void  operator delete(void* p);
 172 
 173  protected:
 174   static void* allocate(size_t size, bool throw_excpt, MEMFLAGS flags = mtThread);
 175  private:
 176 
 177   // ***************************************************************
 178   // Suspend and resume support
 179   // ***************************************************************
 180   //
 181   // VM suspend/resume no longer exists - it was once used for various
 182   // things including safepoints but was deprecated and finally removed
 183   // in Java 7. Because VM suspension was considered "internal" Java-level
 184   // suspension was considered "external", and this legacy naming scheme
 185   // remains.
 186   //
 187   // External suspend/resume requests come from JVM_SuspendThread,
 188   // JVM_ResumeThread, JVMTI SuspendThread, and finally JVMTI
 189   // ResumeThread. External
 190   // suspend requests cause _external_suspend to be set and external
 191   // resume requests cause _external_suspend to be cleared.
 192   // External suspend requests do not nest on top of other external
 193   // suspend requests. The higher level APIs reject suspend requests
 194   // for already suspended threads.
 195   //
 196   // The external_suspend
 197   // flag is checked by has_special_runtime_exit_condition() and java thread
 198   // will self-suspend when handle_special_runtime_exit_condition() is
 199   // called. Most uses of the _thread_blocked state in JavaThreads are
 200   // considered the same as being externally suspended; if the blocking
 201   // condition lifts, the JavaThread will self-suspend. Other places
 202   // where VM checks for external_suspend include:
 203   //   + mutex granting (do not enter monitors when thread is suspended)
 204   //   + state transitions from _thread_in_native
 205   //
 206   // In general, java_suspend() does not wait for an external suspend
 207   // request to complete. When it returns, the only guarantee is that
 208   // the _external_suspend field is true.
 209   //
 210   // wait_for_ext_suspend_completion() is used to wait for an external
 211   // suspend request to complete. External suspend requests are usually
 212   // followed by some other interface call that requires the thread to
 213   // be quiescent, e.g., GetCallTrace(). By moving the "wait time" into
 214   // the interface that requires quiescence, we give the JavaThread a
 215   // chance to self-suspend before we need it to be quiescent. This
 216   // improves overall suspend/query performance.
 217   //
 218   // _suspend_flags controls the behavior of java_ suspend/resume.
 219   // It must be set under the protection of SR_lock. Read from the flag is
 220   // OK without SR_lock as long as the value is only used as a hint.
 221   // (e.g., check _external_suspend first without lock and then recheck
 222   // inside SR_lock and finish the suspension)
 223   //
 224   // _suspend_flags is also overloaded for other "special conditions" so
 225   // that a single check indicates whether any special action is needed
 226   // eg. for async exceptions.
 227   // -------------------------------------------------------------------
 228   // Notes:
 229   // 1. The suspend/resume logic no longer uses ThreadState in OSThread
 230   // but we still update its value to keep other part of the system (mainly
 231   // JVMTI) happy. ThreadState is legacy code (see notes in
 232   // osThread.hpp).
 233   //
 234   // 2. It would be more natural if set_external_suspend() is private and
 235   // part of java_suspend(), but that probably would affect the suspend/query
 236   // performance. Need more investigation on this.
 237 
 238   // suspend/resume lock: used for self-suspend
 239   Monitor* _SR_lock;
 240 
 241  protected:
 242   enum SuspendFlags {
 243     // NOTE: avoid using the sign-bit as cc generates different test code
 244     //       when the sign-bit is used, and sometimes incorrectly - see CR 6398077
 245 
 246     _external_suspend       = 0x20000000U, // thread is asked to self suspend
 247     _ext_suspended          = 0x40000000U, // thread has self-suspended
 248     _deopt_suspend          = 0x10000000U, // thread needs to self suspend for deopt
 249 
 250     _has_async_exception    = 0x00000001U, // there is a pending async exception
 251     _critical_native_unlock = 0x00000002U, // Must call back to unlock JNI critical lock
 252 
 253     _trace_flag             = 0x00000004U  // call tracing backend
 254   };
 255 
 256   // various suspension related flags - atomically updated
 257   // overloaded for async exception checking in check_special_condition_for_native_trans.
 258   volatile uint32_t _suspend_flags;
 259 
 260  private:
 261   int _num_nested_signal;
 262 
 263   DEBUG_ONLY(bool _suspendible_thread;)
 264 
 265  public:
 266   void enter_signal_handler() { _num_nested_signal++; }
 267   void leave_signal_handler() { _num_nested_signal--; }
 268   bool is_inside_signal_handler() const { return _num_nested_signal > 0; }
 269 
 270 #ifdef ASSERT
 271   void set_suspendible_thread() {
 272     _suspendible_thread = true;
 273   }
 274 
 275   void clear_suspendible_thread() {
 276     _suspendible_thread = false;
 277   }
 278 
 279   bool is_suspendible_thread() { return _suspendible_thread; }
 280 #endif
 281 
 282  private:
 283   // Active_handles points to a block of handles
 284   JNIHandleBlock* _active_handles;
 285 
 286   // One-element thread local free list
 287   JNIHandleBlock* _free_handle_block;
 288 
 289   // Point to the last handle mark
 290   HandleMark* _last_handle_mark;
 291 
 292   // The parity of the last strong_roots iteration in which this thread was
 293   // claimed as a task.
 294   int _oops_do_parity;
 295 
 296  public:
 297   void set_last_handle_mark(HandleMark* mark)   { _last_handle_mark = mark; }
 298   HandleMark* last_handle_mark() const          { return _last_handle_mark; }
 299  private:
 300 
 301   // debug support for checking if code does allow safepoints or not
 302   // GC points in the VM can happen because of allocation, invoking a VM operation, or blocking on
 303   // mutex, or blocking on an object synchronizer (Java locking).
 304   // If !allow_safepoint(), then an assertion failure will happen in any of the above cases
 305   // If !allow_allocation(), then an assertion failure will happen during allocation
 306   // (Hence, !allow_safepoint() => !allow_allocation()).
 307   //
 308   // The two classes NoSafepointVerifier and No_Allocation_Verifier are used to set these counters.
 309   //
 310   NOT_PRODUCT(int _allow_safepoint_count;)      // If 0, thread allow a safepoint to happen
 311   debug_only(int _allow_allocation_count;)     // If 0, the thread is allowed to allocate oops.
 312 
 313   // Used by SkipGCALot class.
 314   NOT_PRODUCT(bool _skip_gcalot;)               // Should we elide gc-a-lot?
 315 
 316   friend class NoAllocVerifier;
 317   friend class NoSafepointVerifier;
 318   friend class PauseNoSafepointVerifier;
 319   friend class GCLocker;
 320 
 321   volatile void* _polling_page;                 // Thread local polling page
 322 
 323   ThreadLocalAllocBuffer _tlab;                 // Thread-local eden
 324   jlong _allocated_bytes;                       // Cumulative number of bytes allocated on
 325                                                 // the Java heap
 326 
 327   mutable TRACE_DATA _trace_data;               // Thread-local data for tracing
 328 
 329   ThreadExt _ext;
 330 
 331   int   _vm_operation_started_count;            // VM_Operation support
 332   int   _vm_operation_completed_count;          // VM_Operation support
 333 
 334   ObjectMonitor* _current_pending_monitor;      // ObjectMonitor this thread
 335                                                 // is waiting to lock
 336   bool _current_pending_monitor_is_from_java;   // locking is from Java code
 337 
 338   // ObjectMonitor on which this thread called Object.wait()
 339   ObjectMonitor* _current_waiting_monitor;
 340 
 341   // Private thread-local objectmonitor list - a simple cache organized as a SLL.
 342  public:
 343   ObjectMonitor* omFreeList;
 344   int omFreeCount;                              // length of omFreeList
 345   int omFreeProvision;                          // reload chunk size
 346   ObjectMonitor* omInUseList;                   // SLL to track monitors in circulation
 347   int omInUseCount;                             // length of omInUseList
 348 
 349 #ifdef ASSERT
 350  private:
 351   bool _visited_for_critical_count;
 352 
 353  public:
 354   void set_visited_for_critical_count(bool z) { _visited_for_critical_count = z; }
 355   bool was_visited_for_critical_count() const   { return _visited_for_critical_count; }
 356 #endif
 357 
 358  public:
 359   enum {
 360     is_definitely_current_thread = true
 361   };
 362 
 363   // Constructor
 364   Thread();
 365   virtual ~Thread();
 366 
 367   // Manage Thread::current()
 368   void initialize_thread_current();
 369   void clear_thread_current(); // TLS cleanup needed before threads terminate
 370 
 371   public:
 372   // thread entry point
 373   virtual void run();
 374 
 375   // Testers
 376   virtual bool is_VM_thread()       const            { return false; }
 377   virtual bool is_Java_thread()     const            { return false; }
 378   virtual bool is_Compiler_thread() const            { return false; }
 379   virtual bool is_Code_cache_sweeper_thread() const  { return false; }
 380   virtual bool is_hidden_from_external_view() const  { return false; }
 381   virtual bool is_jvmti_agent_thread() const         { return false; }
 382   // True iff the thread can perform GC operations at a safepoint.
 383   // Generally will be true only of VM thread and parallel GC WorkGang
 384   // threads.
 385   virtual bool is_GC_task_thread() const             { return false; }
 386   virtual bool is_Watcher_thread() const             { return false; }
 387   virtual bool is_ConcurrentGC_thread() const        { return false; }
 388   virtual bool is_Named_thread() const               { return false; }
 389   virtual bool is_Worker_thread() const              { return false; }
 390 
 391   // Can this thread make Java upcalls
 392   virtual bool can_call_java() const                 { return false; }
 393 
 394   // Casts
 395   virtual WorkerThread* as_Worker_thread() const     { return NULL; }
 396 
 397   virtual char* name() const { return (char*)"Unknown thread"; }
 398 
 399   // Returns the current thread (ASSERTS if NULL)
 400   static inline Thread* current();
 401   // Returns the current thread, or NULL if not attached
 402   static inline Thread* current_or_null();
 403   // Returns the current thread, or NULL if not attached, and is
 404   // safe for use from signal-handlers
 405   static inline Thread* current_or_null_safe();
 406 
 407   // Common thread operations
 408 #ifdef ASSERT
 409   static void check_for_dangling_thread_pointer(Thread *thread);
 410 #endif
 411   static void set_priority(Thread* thread, ThreadPriority priority);
 412   static ThreadPriority get_priority(const Thread* const thread);
 413   static void start(Thread* thread);
 414   static void interrupt(Thread* thr);
 415   static bool is_interrupted(Thread* thr, bool clear_interrupted);
 416 
 417   void set_native_thread_name(const char *name) {
 418     assert(Thread::current() == this, "set_native_thread_name can only be called on the current thread");
 419     os::set_native_thread_name(name);
 420   }
 421 
 422   ObjectMonitor** omInUseList_addr()             { return (ObjectMonitor **)&omInUseList; }
 423   Monitor* SR_lock() const                       { return _SR_lock; }
 424 
 425   bool has_async_exception() const { return (_suspend_flags & _has_async_exception) != 0; }
 426 
 427   inline void set_suspend_flag(SuspendFlags f);
 428   inline void clear_suspend_flag(SuspendFlags f);
 429 
 430   inline void set_has_async_exception();
 431   inline void clear_has_async_exception();
 432 
 433   bool do_critical_native_unlock() const { return (_suspend_flags & _critical_native_unlock) != 0; }
 434 
 435   inline void set_critical_native_unlock();
 436   inline void clear_critical_native_unlock();
 437 
 438   inline void set_trace_flag();
 439   inline void clear_trace_flag();
 440 
 441   // Support for Unhandled Oop detection
 442   // Add the field for both, fastdebug and debug, builds to keep
 443   // Thread's fields layout the same.
 444   // Note: CHECK_UNHANDLED_OOPS is defined only for fastdebug build.
 445 #ifdef CHECK_UNHANDLED_OOPS
 446  private:
 447   UnhandledOops* _unhandled_oops;
 448 #elif defined(ASSERT)
 449  private:
 450   void* _unhandled_oops;
 451 #endif
 452 #ifdef CHECK_UNHANDLED_OOPS
 453  public:
 454   UnhandledOops* unhandled_oops() { return _unhandled_oops; }
 455   // Mark oop safe for gc.  It may be stack allocated but won't move.
 456   void allow_unhandled_oop(oop *op) {
 457     if (CheckUnhandledOops) unhandled_oops()->allow_unhandled_oop(op);
 458   }
 459   // Clear oops at safepoint so crashes point to unhandled oop violator
 460   void clear_unhandled_oops() {
 461     if (CheckUnhandledOops) unhandled_oops()->clear_unhandled_oops();
 462   }
 463 #endif // CHECK_UNHANDLED_OOPS
 464 
 465  public:
 466 #ifndef PRODUCT
 467   bool skip_gcalot()           { return _skip_gcalot; }
 468   void set_skip_gcalot(bool v) { _skip_gcalot = v;    }
 469 #endif
 470 
 471   // Installs a pending exception to be inserted later
 472   static void send_async_exception(oop thread_oop, oop java_throwable);
 473 
 474   // Resource area
 475   ResourceArea* resource_area() const            { return _resource_area; }
 476   void set_resource_area(ResourceArea* area)     { _resource_area = area; }
 477 
 478   OSThread* osthread() const                     { return _osthread;   }
 479   void set_osthread(OSThread* thread)            { _osthread = thread; }
 480 
 481   // JNI handle support
 482   JNIHandleBlock* active_handles() const         { return _active_handles; }
 483   void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
 484   JNIHandleBlock* free_handle_block() const      { return _free_handle_block; }
 485   void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
 486 
 487   // Internal handle support
 488   HandleArea* handle_area() const                { return _handle_area; }
 489   void set_handle_area(HandleArea* area)         { _handle_area = area; }
 490 
 491   GrowableArray<Metadata*>* metadata_handles() const          { return _metadata_handles; }
 492   void set_metadata_handles(GrowableArray<Metadata*>* handles){ _metadata_handles = handles; }
 493 
 494   // Thread-Local Allocation Buffer (TLAB) support
 495   ThreadLocalAllocBuffer& tlab()                 { return _tlab; }
 496   void initialize_tlab() {
 497     if (UseTLAB) {
 498       tlab().initialize();
 499     }
 500   }
 501 
 502   jlong allocated_bytes()               { return _allocated_bytes; }
 503   void set_allocated_bytes(jlong value) { _allocated_bytes = value; }
 504   void incr_allocated_bytes(jlong size) { _allocated_bytes += size; }
 505   inline jlong cooked_allocated_bytes();
 506 
 507   TRACE_DEFINE_THREAD_TRACE_DATA_OFFSET;
 508   TRACE_DATA* trace_data() const        { return &_trace_data; }
 509   bool is_trace_suspend()               { return (_suspend_flags & _trace_flag) != 0; }
 510 
 511   const ThreadExt& ext() const          { return _ext; }
 512   ThreadExt& ext()                      { return _ext; }
 513 
 514   // VM operation support
 515   int vm_operation_ticket()                      { return ++_vm_operation_started_count; }
 516   int vm_operation_completed_count()             { return _vm_operation_completed_count; }
 517   void increment_vm_operation_completed_count()  { _vm_operation_completed_count++; }
 518 
 519   // For tracking the heavyweight monitor the thread is pending on.
 520   ObjectMonitor* current_pending_monitor() {
 521     return _current_pending_monitor;
 522   }
 523   void set_current_pending_monitor(ObjectMonitor* monitor) {
 524     _current_pending_monitor = monitor;
 525   }
 526   void set_current_pending_monitor_is_from_java(bool from_java) {
 527     _current_pending_monitor_is_from_java = from_java;
 528   }
 529   bool current_pending_monitor_is_from_java() {
 530     return _current_pending_monitor_is_from_java;
 531   }
 532 
 533   // For tracking the ObjectMonitor on which this thread called Object.wait()
 534   ObjectMonitor* current_waiting_monitor() {
 535     return _current_waiting_monitor;
 536   }
 537   void set_current_waiting_monitor(ObjectMonitor* monitor) {
 538     _current_waiting_monitor = monitor;
 539   }
 540 
 541   // GC support
 542   // Apply "f->do_oop" to all root oops in "this".
 543   //   Used by JavaThread::oops_do.
 544   // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames
 545   virtual void oops_do(OopClosure* f, CodeBlobClosure* cf);
 546 
 547   // Handles the parallel case for the method below.
 548  private:
 549   bool claim_oops_do_par_case(int collection_parity);
 550  public:
 551   // Requires that "collection_parity" is that of the current roots
 552   // iteration.  If "is_par" is false, sets the parity of "this" to
 553   // "collection_parity", and returns "true".  If "is_par" is true,
 554   // uses an atomic instruction to set the current threads parity to
 555   // "collection_parity", if it is not already.  Returns "true" iff the
 556   // calling thread does the update, this indicates that the calling thread
 557   // has claimed the thread's stack as a root groop in the current
 558   // collection.
 559   bool claim_oops_do(bool is_par, int collection_parity) {
 560     if (!is_par) {
 561       _oops_do_parity = collection_parity;
 562       return true;
 563     } else {
 564       return claim_oops_do_par_case(collection_parity);
 565     }
 566   }
 567 
 568   // jvmtiRedefineClasses support
 569   void metadata_handles_do(void f(Metadata*));
 570 
 571   // Used by fast lock support
 572   virtual bool is_lock_owned(address adr) const;
 573 
 574   // Check if address is in the stack of the thread (not just for locks).
 575   // Warning: the method can only be used on the running thread
 576   bool is_in_stack(address adr) const;
 577   // Check if address is in the usable part of the stack (excludes protected
 578   // guard pages)
 579   bool is_in_usable_stack(address adr) const;
 580 
 581   // Sets this thread as starting thread. Returns failure if thread
 582   // creation fails due to lack of memory, too many threads etc.
 583   bool set_as_starting_thread();
 584 
 585 protected:
 586   // OS data associated with the thread
 587   OSThread* _osthread;  // Platform-specific thread information
 588 
 589   // Thread local resource area for temporary allocation within the VM
 590   ResourceArea* _resource_area;
 591 
 592   DEBUG_ONLY(ResourceMark* _current_resource_mark;)
 593 
 594   // Thread local handle area for allocation of handles within the VM
 595   HandleArea* _handle_area;
 596   GrowableArray<Metadata*>* _metadata_handles;
 597 
 598   // Support for stack overflow handling, get_thread, etc.
 599   address          _stack_base;
 600   size_t           _stack_size;
 601   uintptr_t        _self_raw_id;      // used by get_thread (mutable)
 602   int              _lgrp_id;
 603 
 604   volatile void** polling_page_addr() { return &_polling_page; }
 605 
 606  public:
 607   // Stack overflow support
 608   address stack_base() const           { assert(_stack_base != NULL,"Sanity check"); return _stack_base; }
 609   void    set_stack_base(address base) { _stack_base = base; }
 610   size_t  stack_size() const           { return _stack_size; }
 611   void    set_stack_size(size_t size)  { _stack_size = size; }
 612   address stack_end()  const           { return stack_base() - stack_size(); }
 613   void    record_stack_base_and_size();
 614 
 615   bool    on_local_stack(address adr) const {
 616     // QQQ this has knowledge of direction, ought to be a stack method
 617     return (_stack_base >= adr && adr >= stack_end());
 618   }
 619 
 620   uintptr_t self_raw_id()                    { return _self_raw_id; }
 621   void      set_self_raw_id(uintptr_t value) { _self_raw_id = value; }
 622 
 623   int     lgrp_id() const        { return _lgrp_id; }
 624   void    set_lgrp_id(int value) { _lgrp_id = value; }
 625 
 626   // Printing
 627   virtual void print_on(outputStream* st) const;
 628   virtual void print_nested_threads_hazard_ptrs_on(outputStream* st) const;
 629   void print() const { print_on(tty); }
 630   virtual void print_on_error(outputStream* st, char* buf, int buflen) const;
 631   void print_value_on(outputStream* st) const;
 632 
 633   // Debug-only code
 634 #ifdef ASSERT
 635  private:
 636   // Deadlock detection support for Mutex locks. List of locks own by thread.
 637   Monitor* _owned_locks;
 638   // Mutex::set_owner_implementation is the only place where _owned_locks is modified,
 639   // thus the friendship
 640   friend class Mutex;
 641   friend class Monitor;
 642 
 643  public:
 644   void print_owned_locks_on(outputStream* st) const;
 645   void print_owned_locks() const                 { print_owned_locks_on(tty);    }
 646   Monitor* owned_locks() const                   { return _owned_locks;          }
 647   bool owns_locks() const                        { return owned_locks() != NULL; }
 648   bool owns_locks_but_compiled_lock() const;
 649   int oops_do_parity() const                     { return _oops_do_parity; }
 650 
 651   // Deadlock detection
 652   bool allow_allocation()                        { return _allow_allocation_count == 0; }
 653   ResourceMark* current_resource_mark()          { return _current_resource_mark; }
 654   void set_current_resource_mark(ResourceMark* rm) { _current_resource_mark = rm; }
 655 #endif
 656 
 657   void check_for_valid_safepoint_state(bool potential_vm_operation) PRODUCT_RETURN;
 658 
 659  private:
 660   volatile int _jvmti_env_iteration_count;
 661 
 662  public:
 663   void entering_jvmti_env_iteration()            { ++_jvmti_env_iteration_count; }
 664   void leaving_jvmti_env_iteration()             { --_jvmti_env_iteration_count; }
 665   bool is_inside_jvmti_env_iteration()           { return _jvmti_env_iteration_count > 0; }
 666 
 667   // Code generation
 668   static ByteSize exception_file_offset()        { return byte_offset_of(Thread, _exception_file); }
 669   static ByteSize exception_line_offset()        { return byte_offset_of(Thread, _exception_line); }
 670   static ByteSize active_handles_offset()        { return byte_offset_of(Thread, _active_handles); }
 671 
 672   static ByteSize stack_base_offset()            { return byte_offset_of(Thread, _stack_base); }
 673   static ByteSize stack_size_offset()            { return byte_offset_of(Thread, _stack_size); }
 674 
 675   static ByteSize polling_page_offset()          { return byte_offset_of(Thread, _polling_page); }
 676 
 677 #define TLAB_FIELD_OFFSET(name) \
 678   static ByteSize tlab_##name##_offset()         { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::name##_offset(); }
 679 
 680   TLAB_FIELD_OFFSET(start)
 681   TLAB_FIELD_OFFSET(end)
 682   TLAB_FIELD_OFFSET(top)
 683   TLAB_FIELD_OFFSET(pf_top)
 684   TLAB_FIELD_OFFSET(size)                   // desired_size
 685   TLAB_FIELD_OFFSET(refill_waste_limit)
 686   TLAB_FIELD_OFFSET(number_of_refills)
 687   TLAB_FIELD_OFFSET(fast_refill_waste)
 688   TLAB_FIELD_OFFSET(slow_allocations)
 689 
 690 #undef TLAB_FIELD_OFFSET
 691 
 692   static ByteSize allocated_bytes_offset()       { return byte_offset_of(Thread, _allocated_bytes); }
 693 
 694  public:
 695   volatile intptr_t _Stalled;
 696   volatile int _TypeTag;
 697   ParkEvent * _ParkEvent;                     // for synchronized()
 698   ParkEvent * _SleepEvent;                    // for Thread.sleep
 699   ParkEvent * _MutexEvent;                    // for native internal Mutex/Monitor
 700   ParkEvent * _MuxEvent;                      // for low-level muxAcquire-muxRelease
 701   int NativeSyncRecursion;                    // diagnostic
 702 
 703   volatile int _OnTrap;                       // Resume-at IP delta
 704   jint _hashStateW;                           // Marsaglia Shift-XOR thread-local RNG
 705   jint _hashStateX;                           // thread-specific hashCode generator state
 706   jint _hashStateY;
 707   jint _hashStateZ;
 708   void * _schedctl;
 709 
 710 
 711   volatile jint rng[4];                      // RNG for spin loop
 712 
 713   // Low-level leaf-lock primitives used to implement synchronization
 714   // and native monitor-mutex infrastructure.
 715   // Not for general synchronization use.
 716   static void SpinAcquire(volatile int * Lock, const char * Name);
 717   static void SpinRelease(volatile int * Lock);
 718   static void muxAcquire(volatile intptr_t * Lock, const char * Name);
 719   static void muxAcquireW(volatile intptr_t * Lock, ParkEvent * ev);
 720   static void muxRelease(volatile intptr_t * Lock);
 721 };
 722 
 723 // Inline implementation of Thread::current()
 724 inline Thread* Thread::current() {
 725   Thread* current = current_or_null();
 726   assert(current != NULL, "Thread::current() called on detached thread");
 727   return current;
 728 }
 729 
 730 inline Thread* Thread::current_or_null() {
 731 #ifndef USE_LIBRARY_BASED_TLS_ONLY
 732   return _thr_current;
 733 #else
 734   if (ThreadLocalStorage::is_initialized()) {
 735     return ThreadLocalStorage::thread();
 736   }
 737   return NULL;
 738 #endif
 739 }
 740 
 741 inline Thread* Thread::current_or_null_safe() {
 742   if (ThreadLocalStorage::is_initialized()) {
 743     return ThreadLocalStorage::thread();
 744   }
 745   return NULL;
 746 }
 747 
 748 // Name support for threads.  non-JavaThread subclasses with multiple
 749 // uniquely named instances should derive from this.
 750 class NamedThread: public Thread {
 751   friend class VMStructs;
 752   enum {
 753     max_name_len = 64
 754   };
 755  private:
 756   char* _name;
 757   // log JavaThread being processed by oops_do
 758   JavaThread* _processed_thread;
 759   uint _gc_id; // The current GC id when a thread takes part in GC
 760 
 761  public:
 762   NamedThread();
 763   ~NamedThread();
 764   // May only be called once per thread.
 765   void set_name(const char* format, ...)  ATTRIBUTE_PRINTF(2, 3);
 766   void initialize_named_thread();
 767   virtual bool is_Named_thread() const { return true; }
 768   virtual char* name() const { return _name == NULL ? (char*)"Unknown Thread" : _name; }
 769   JavaThread *processed_thread() { return _processed_thread; }
 770   void set_processed_thread(JavaThread *thread) { _processed_thread = thread; }
 771   virtual void print_on(outputStream* st) const;
 772 
 773   void set_gc_id(uint gc_id) { _gc_id = gc_id; }
 774   uint gc_id() { return _gc_id; }
 775 };
 776 
 777 // Worker threads are named and have an id of an assigned work.
 778 class WorkerThread: public NamedThread {
 779  private:
 780   uint _id;
 781  public:
 782   WorkerThread() : _id(0)               { }
 783   virtual bool is_Worker_thread() const { return true; }
 784 
 785   virtual WorkerThread* as_Worker_thread() const {
 786     assert(is_Worker_thread(), "Dubious cast to WorkerThread*?");
 787     return (WorkerThread*) this;
 788   }
 789 
 790   void set_id(uint work_id)             { _id = work_id; }
 791   uint id() const                       { return _id; }
 792 };
 793 
 794 // A single WatcherThread is used for simulating timer interrupts.
 795 class WatcherThread: public Thread {
 796   friend class VMStructs;
 797  public:
 798   virtual void run();
 799 
 800  private:
 801   static WatcherThread* _watcher_thread;
 802 
 803   static bool _startable;
 804   // volatile due to at least one lock-free read
 805   volatile static bool _should_terminate;
 806  public:
 807   enum SomeConstants {
 808     delay_interval = 10                          // interrupt delay in milliseconds
 809   };
 810 
 811   // Constructor
 812   WatcherThread();
 813 
 814   // No destruction allowed
 815   ~WatcherThread() {
 816     guarantee(false, "WatcherThread deletion must fix the race with VM termination");
 817   }
 818 
 819   // Tester
 820   bool is_Watcher_thread() const                 { return true; }
 821 
 822   // Printing
 823   char* name() const { return (char*)"VM Periodic Task Thread"; }
 824   void print_on(outputStream* st) const;
 825   void unpark();
 826 
 827   // Returns the single instance of WatcherThread
 828   static WatcherThread* watcher_thread()         { return _watcher_thread; }
 829 
 830   // Create and start the single instance of WatcherThread, or stop it on shutdown
 831   static void start();
 832   static void stop();
 833   // Only allow start once the VM is sufficiently initialized
 834   // Otherwise the first task to enroll will trigger the start
 835   static void make_startable();
 836  private:
 837   int sleep() const;
 838 };
 839 
 840 
 841 class CompilerThread;
 842 
 843 typedef void (*ThreadFunction)(JavaThread*, TRAPS);
 844 
 845 class JavaThread: public Thread {
 846   friend class VMStructs;
 847   friend class JVMCIVMStructs;
 848   friend class WhiteBox;
 849  private:
 850   JavaThread*    _next;                          // The next thread in the Threads list
 851   bool           _on_thread_list;                // Is set when this JavaThread is added to the Threads list
 852   oop            _threadObj;                     // The Java level thread object
 853 
 854 #ifdef ASSERT
 855  private:
 856   int _java_call_counter;
 857 
 858  public:
 859   int  java_call_counter()                       { return _java_call_counter; }
 860   void inc_java_call_counter()                   { _java_call_counter++; }
 861   void dec_java_call_counter() {
 862     assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
 863     _java_call_counter--;
 864   }
 865  private:  // restore original namespace restriction
 866 #endif  // ifdef ASSERT
 867 
 868 #ifndef PRODUCT
 869  public:
 870   enum {
 871     jump_ring_buffer_size = 16
 872   };
 873  private:  // restore original namespace restriction
 874 #endif
 875 
 876   JavaFrameAnchor _anchor;                       // Encapsulation of current java frame and it state
 877 
 878   ThreadFunction _entry_point;
 879 
 880   JNIEnv        _jni_environment;
 881 
 882   // Deopt support
 883   DeoptResourceMark*  _deopt_mark;               // Holds special ResourceMark for deoptimization
 884 
 885   intptr_t*      _must_deopt_id;                 // id of frame that needs to be deopted once we
 886                                                  // transition out of native
 887   CompiledMethod*       _deopt_nmethod;         // CompiledMethod that is currently being deoptimized
 888   vframeArray*  _vframe_array_head;              // Holds the heap of the active vframeArrays
 889   vframeArray*  _vframe_array_last;              // Holds last vFrameArray we popped
 890   // Because deoptimization is lazy we must save jvmti requests to set locals
 891   // in compiled frames until we deoptimize and we have an interpreter frame.
 892   // This holds the pointer to array (yeah like there might be more than one) of
 893   // description of compiled vframes that have locals that need to be updated.
 894   GrowableArray<jvmtiDeferredLocalVariableSet*>* _deferred_locals_updates;
 895 
 896   // Handshake value for fixing 6243940. We need a place for the i2c
 897   // adapter to store the callee Method*. This value is NEVER live
 898   // across a gc point so it does NOT have to be gc'd
 899   // The handshake is open ended since we can't be certain that it will
 900   // be NULLed. This is because we rarely ever see the race and end up
 901   // in handle_wrong_method which is the backend of the handshake. See
 902   // code in i2c adapters and handle_wrong_method.
 903 
 904   Method*       _callee_target;
 905 
 906   // Used to pass back results to the interpreter or generated code running Java code.
 907   oop           _vm_result;    // oop result is GC-preserved
 908   Metadata*     _vm_result_2;  // non-oop result
 909 
 910   // See ReduceInitialCardMarks: this holds the precise space interval of
 911   // the most recent slow path allocation for which compiled code has
 912   // elided card-marks for performance along the fast-path.
 913   MemRegion     _deferred_card_mark;
 914 
 915   MonitorChunk* _monitor_chunks;                 // Contains the off stack monitors
 916                                                  // allocated during deoptimization
 917                                                  // and by JNI_MonitorEnter/Exit
 918 
 919   // Async. requests support
 920   enum AsyncRequests {
 921     _no_async_condition = 0,
 922     _async_exception,
 923     _async_unsafe_access_error
 924   };
 925   AsyncRequests _special_runtime_exit_condition; // Enum indicating pending async. request
 926   oop           _pending_async_exception;
 927 
 928   // Safepoint support
 929  public:                                         // Expose _thread_state for SafeFetchInt()
 930   volatile JavaThreadState _thread_state;
 931  private:
 932   ThreadSafepointState *_safepoint_state;        // Holds information about a thread during a safepoint
 933   address               _saved_exception_pc;     // Saved pc of instruction where last implicit exception happened
 934 
 935   // JavaThread termination support
 936   enum TerminatedTypes {
 937     _not_terminated = 0xDEAD - 2,
 938     _thread_exiting,                             // JavaThread::exit() has been called for this thread
 939     _thread_terminated,                          // JavaThread is removed from thread list
 940     _vm_exited                                   // JavaThread is still executing native code, but VM is terminated
 941                                                  // only VM_Exit can set _vm_exited
 942   };
 943 
 944   // In general a JavaThread's _terminated field transitions as follows:
 945   //
 946   //   _not_terminated => _thread_exiting => _thread_terminated
 947   //
 948   // _vm_exited is a special value to cover the case of a JavaThread
 949   // executing native code after the VM itself is terminated.
 950   volatile TerminatedTypes _terminated;
 951   // suspend/resume support
 952   volatile bool         _suspend_equivalent;     // Suspend equivalent condition
 953   jint                  _in_deopt_handler;       // count of deoptimization
 954                                                  // handlers thread is in
 955   volatile bool         _doing_unsafe_access;    // Thread may fault due to unsafe access
 956   bool                  _do_not_unlock_if_synchronized;  // Do not unlock the receiver of a synchronized method (since it was
 957                                                          // never locked) when throwing an exception. Used by interpreter only.
 958 
 959   // JNI attach states:
 960   enum JNIAttachStates {
 961     _not_attaching_via_jni = 1,  // thread is not attaching via JNI
 962     _attaching_via_jni,          // thread is attaching via JNI
 963     _attached_via_jni            // thread has attached via JNI
 964   };
 965 
 966   // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
 967   // A native thread that is attaching via JNI starts with a value
 968   // of _attaching_via_jni and transitions to _attached_via_jni.
 969   volatile JNIAttachStates _jni_attach_state;
 970 
 971  public:
 972   // State of the stack guard pages for this thread.
 973   enum StackGuardState {
 974     stack_guard_unused,         // not needed
 975     stack_guard_reserved_disabled,
 976     stack_guard_yellow_reserved_disabled,// disabled (temporarily) after stack overflow
 977     stack_guard_enabled         // enabled
 978   };
 979 
 980  private:
 981 
 982 #if INCLUDE_JVMCI
 983   // The _pending_* fields below are used to communicate extra information
 984   // from an uncommon trap in JVMCI compiled code to the uncommon trap handler.
 985 
 986   // Communicates the DeoptReason and DeoptAction of the uncommon trap
 987   int       _pending_deoptimization;
 988 
 989   // Specifies whether the uncommon trap is to bci 0 of a synchronized method
 990   // before the monitor has been acquired.
 991   bool      _pending_monitorenter;
 992 
 993   // Specifies if the DeoptReason for the last uncommon trap was Reason_transfer_to_interpreter
 994   bool      _pending_transfer_to_interpreter;
 995 
 996   // Guard for re-entrant call to JVMCIRuntime::adjust_comp_level
 997   bool      _adjusting_comp_level;
 998 
 999   // An object that JVMCI compiled code can use to further describe and
1000   // uniquely identify the  speculative optimization guarded by the uncommon trap
1001   oop       _pending_failed_speculation;
1002 
1003   // These fields are mutually exclusive in terms of live ranges.
1004   union {
1005     // Communicates the pc at which the most recent implicit exception occurred
1006     // from the signal handler to a deoptimization stub.
1007     address   _implicit_exception_pc;
1008 
1009     // Communicates an alternative call target to an i2c stub from a JavaCall .
1010     address   _alternate_call_target;
1011   } _jvmci;
1012 
1013   // Support for high precision, thread sensitive counters in JVMCI compiled code.
1014   jlong*    _jvmci_counters;
1015 
1016  public:
1017   static jlong* _jvmci_old_thread_counters;
1018   static void collect_counters(typeArrayOop array);
1019  private:
1020 #endif // INCLUDE_JVMCI
1021 
1022   StackGuardState  _stack_guard_state;
1023 
1024   // Precompute the limit of the stack as used in stack overflow checks.
1025   // We load it from here to simplify the stack overflow check in assembly.
1026   address          _stack_overflow_limit;
1027   address          _reserved_stack_activation;
1028 
1029   // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
1030   // used to temp. parsing values into and out of the runtime system during exception handling for compiled
1031   // code)
1032   volatile oop     _exception_oop;               // Exception thrown in compiled code
1033   volatile address _exception_pc;                // PC where exception happened
1034   volatile address _exception_handler_pc;        // PC for handler of exception
1035   volatile int     _is_method_handle_return;     // true (== 1) if the current exception PC is a MethodHandle call site.
1036 
1037  private:
1038   // support for JNI critical regions
1039   jint    _jni_active_critical;                  // count of entries into JNI critical region
1040 
1041   // Checked JNI: function name requires exception check
1042   char* _pending_jni_exception_check_fn;
1043 
1044   // For deadlock detection.
1045   int _depth_first_number;
1046 
1047   // JVMTI PopFrame support
1048   // This is set to popframe_pending to signal that top Java frame should be popped immediately
1049   int _popframe_condition;
1050 
1051   // If reallocation of scalar replaced objects fails, we throw OOM
1052   // and during exception propagation, pop the top
1053   // _frames_to_pop_failed_realloc frames, the ones that reference
1054   // failed reallocations.
1055   int _frames_to_pop_failed_realloc;
1056 
1057 #ifndef PRODUCT
1058   int _jmp_ring_index;
1059   struct {
1060     // We use intptr_t instead of address so debugger doesn't try and display strings
1061     intptr_t _target;
1062     intptr_t _instruction;
1063     const char*  _file;
1064     int _line;
1065   }   _jmp_ring[jump_ring_buffer_size];
1066 #endif // PRODUCT
1067 
1068 #if INCLUDE_ALL_GCS
1069   // Support for G1 barriers
1070 
1071   SATBMarkQueue _satb_mark_queue;        // Thread-local log for SATB barrier.
1072   // Set of all such queues.
1073   static SATBMarkQueueSet _satb_mark_queue_set;
1074 
1075   DirtyCardQueue _dirty_card_queue;      // Thread-local log for dirty cards.
1076   // Set of all such queues.
1077   static DirtyCardQueueSet _dirty_card_queue_set;
1078 #endif // INCLUDE_ALL_GCS
1079 
1080   friend class VMThread;
1081   friend class ThreadWaitTransition;
1082   friend class VM_Exit;
1083 
1084   void initialize();                             // Initialized the instance variables
1085 
1086  public:
1087   // Constructor
1088   JavaThread(bool is_attaching_via_jni = false); // for main thread and JNI attached threads
1089   JavaThread(ThreadFunction entry_point, size_t stack_size = 0);
1090   ~JavaThread();
1091 
1092 #ifdef ASSERT
1093   // verify this JavaThread hasn't be published in the Threads::list yet
1094   void verify_not_published();
1095 #endif
1096 
1097   //JNI functiontable getter/setter for JVMTI jni function table interception API.
1098   void set_jni_functions(struct JNINativeInterface_* functionTable) {
1099     _jni_environment.functions = functionTable;
1100   }
1101   struct JNINativeInterface_* get_jni_functions() {
1102     return (struct JNINativeInterface_ *)_jni_environment.functions;
1103   }
1104 
1105   // This function is called at thread creation to allow
1106   // platform specific thread variables to be initialized.
1107   void cache_global_variables();
1108 
1109   // Executes Shutdown.shutdown()
1110   void invoke_shutdown_hooks();
1111 
1112   // Cleanup on thread exit
1113   enum ExitType {
1114     normal_exit,
1115     jni_detach
1116   };
1117   void exit(bool destroy_vm, ExitType exit_type = normal_exit);
1118 
1119   void cleanup_failed_attach_current_thread();
1120 
1121   // Testers
1122   virtual bool is_Java_thread() const            { return true;  }
1123   virtual bool can_call_java() const             { return true; }
1124 
1125   // Thread chain operations
1126   JavaThread* next() const                       { return _next; }
1127   void set_next(JavaThread* p)                   { _next = p; }
1128 
1129   // Thread oop. threadObj() can be NULL for initial JavaThread
1130   // (or for threads attached via JNI)
1131   oop threadObj() const                          { return _threadObj; }
1132   void set_threadObj(oop p)                      { _threadObj = p; }
1133 
1134   ThreadPriority java_priority() const;          // Read from threadObj()
1135 
1136   // Prepare thread and add to priority queue.  If a priority is
1137   // not specified, use the priority of the thread object. Threads_lock
1138   // must be held while this function is called.
1139   void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
1140   void prepare_ext();
1141 
1142   void set_saved_exception_pc(address pc)        { _saved_exception_pc = pc; }
1143   address saved_exception_pc()                   { return _saved_exception_pc; }
1144 
1145 
1146   ThreadFunction entry_point() const             { return _entry_point; }
1147 
1148   // Allocates a new Java level thread object for this thread. thread_name may be NULL.
1149   void allocate_threadObj(Handle thread_group, const char* thread_name, bool daemon, TRAPS);
1150 
1151   // Last frame anchor routines
1152 
1153   JavaFrameAnchor* frame_anchor(void)            { return &_anchor; }
1154 
1155   // last_Java_sp
1156   bool has_last_Java_frame() const               { return _anchor.has_last_Java_frame(); }
1157   intptr_t* last_Java_sp() const                 { return _anchor.last_Java_sp(); }
1158 
1159   // last_Java_pc
1160 
1161   address last_Java_pc(void)                     { return _anchor.last_Java_pc(); }
1162 
1163   // Safepoint support
1164 #if !(defined(PPC64) || defined(AARCH64))
1165   JavaThreadState thread_state() const           { return _thread_state; }
1166   void set_thread_state(JavaThreadState s)       { _thread_state = s;    }
1167 #else
1168   // Use membars when accessing volatile _thread_state. See
1169   // Threads::create_vm() for size checks.
1170   inline JavaThreadState thread_state() const;
1171   inline void set_thread_state(JavaThreadState s);
1172 #endif
1173   ThreadSafepointState *safepoint_state() const  { return _safepoint_state; }
1174   void set_safepoint_state(ThreadSafepointState *state) { _safepoint_state = state; }
1175   bool is_at_poll_safepoint()                    { return _safepoint_state->is_at_poll_safepoint(); }
1176 
1177   // JavaThread termination and lifecycle support:
1178   void smr_delete();
1179   bool on_thread_list() const { return _on_thread_list; }
1180   void set_on_thread_list() { _on_thread_list = true; }
1181 
1182   // thread has called JavaThread::exit() or is terminated
1183   bool is_exiting() const;
1184   // thread is terminated (no longer on the threads list); we compare
1185   // against the two non-terminated values so that a freed JavaThread
1186   // will also be considered terminated.
1187   bool check_is_terminated(TerminatedTypes l_terminated) const {
1188     return l_terminated != _not_terminated && l_terminated != _thread_exiting;
1189   }
1190   bool is_terminated() const;
1191   void set_terminated(TerminatedTypes t);
1192   // special for Threads::remove() which is static:
1193   void set_terminated_value();
1194   void block_if_vm_exited();
1195 
1196   bool doing_unsafe_access()                     { return _doing_unsafe_access; }
1197   void set_doing_unsafe_access(bool val)         { _doing_unsafe_access = val; }
1198 
1199   bool do_not_unlock_if_synchronized()             { return _do_not_unlock_if_synchronized; }
1200   void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
1201 
1202   inline void set_polling_page(void* poll_value);
1203   inline volatile void* get_polling_page();
1204 
1205  private:
1206   // Support for thread handshake operations
1207   HandshakeState _handshake;
1208  public:
1209   void set_handshake_operation(HandshakeOperation* op) {
1210     _handshake.set_operation(this, op);
1211   }
1212 
1213   bool has_handshake() const {
1214     return _handshake.has_operation();
1215   }
1216 
1217   void cancel_handshake() {
1218     _handshake.cancel(this);
1219   }
1220 
1221   void handshake_process_by_self() {
1222     _handshake.process_by_self(this);
1223   }
1224 
1225   void handshake_process_by_vmthread() {
1226     _handshake.process_by_vmthread(this);
1227   }
1228 
1229   // Suspend/resume support for JavaThread
1230  private:
1231   inline void set_ext_suspended();
1232   inline void clear_ext_suspended();
1233 
1234  public:
1235   void java_suspend();
1236   void java_resume();
1237   int  java_suspend_self();
1238 
1239   void check_and_wait_while_suspended() {
1240     assert(JavaThread::current() == this, "sanity check");
1241 
1242     bool do_self_suspend;
1243     do {
1244       // were we externally suspended while we were waiting?
1245       do_self_suspend = handle_special_suspend_equivalent_condition();
1246       if (do_self_suspend) {
1247         // don't surprise the thread that suspended us by returning
1248         java_suspend_self();
1249         set_suspend_equivalent();
1250       }
1251     } while (do_self_suspend);
1252   }
1253   static void check_safepoint_and_suspend_for_native_trans(JavaThread *thread);
1254   // Check for async exception in addition to safepoint and suspend request.
1255   static void check_special_condition_for_native_trans(JavaThread *thread);
1256 
1257   // Same as check_special_condition_for_native_trans but finishes the
1258   // transition into thread_in_Java mode so that it can potentially
1259   // block.
1260   static void check_special_condition_for_native_trans_and_transition(JavaThread *thread);
1261 
1262   bool is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits);
1263   bool is_ext_suspend_completed_with_lock(uint32_t *bits) {
1264     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1265     // Warning: is_ext_suspend_completed() may temporarily drop the
1266     // SR_lock to allow the thread to reach a stable thread state if
1267     // it is currently in a transient thread state.
1268     return is_ext_suspend_completed(false /* !called_by_wait */,
1269                                     SuspendRetryDelay, bits);
1270   }
1271 
1272   // We cannot allow wait_for_ext_suspend_completion() to run forever or
1273   // we could hang. SuspendRetryCount and SuspendRetryDelay are normally
1274   // passed as the count and delay parameters. Experiments with specific
1275   // calls to wait_for_ext_suspend_completion() can be done by passing
1276   // other values in the code. Experiments with all calls can be done
1277   // via the appropriate -XX options.
1278   bool wait_for_ext_suspend_completion(int count, int delay, uint32_t *bits);
1279 
1280   // test for suspend - most (all?) of these should go away
1281   bool is_thread_fully_suspended(bool wait_for_suspend, uint32_t *bits);
1282 
1283   inline void set_external_suspend();
1284   inline void clear_external_suspend();
1285 
1286   inline void set_deopt_suspend();
1287   inline void clear_deopt_suspend();
1288   bool is_deopt_suspend()         { return (_suspend_flags & _deopt_suspend) != 0; }
1289 
1290   bool is_external_suspend() const {
1291     return (_suspend_flags & _external_suspend) != 0;
1292   }
1293   // Whenever a thread transitions from native to vm/java it must suspend
1294   // if external|deopt suspend is present.
1295   bool is_suspend_after_native() const {
1296     return (_suspend_flags & (_external_suspend | _deopt_suspend)) != 0;
1297   }
1298 
1299   // external suspend request is completed
1300   bool is_ext_suspended() const {
1301     return (_suspend_flags & _ext_suspended) != 0;
1302   }
1303 
1304   bool is_external_suspend_with_lock() const {
1305     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1306     return is_external_suspend();
1307   }
1308 
1309   // Special method to handle a pending external suspend request
1310   // when a suspend equivalent condition lifts.
1311   bool handle_special_suspend_equivalent_condition() {
1312     assert(is_suspend_equivalent(),
1313            "should only be called in a suspend equivalence condition");
1314     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1315     bool ret = is_external_suspend();
1316     if (!ret) {
1317       // not about to self-suspend so clear suspend equivalence
1318       clear_suspend_equivalent();
1319     }
1320     // implied else:
1321     // We have a pending external suspend request so we leave the
1322     // suspend_equivalent flag set until java_suspend_self() sets
1323     // the ext_suspended flag and clears the suspend_equivalent
1324     // flag. This insures that wait_for_ext_suspend_completion()
1325     // will return consistent values.
1326     return ret;
1327   }
1328 
1329   // utility methods to see if we are doing some kind of suspension
1330   bool is_being_ext_suspended() const            {
1331     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1332     return is_ext_suspended() || is_external_suspend();
1333   }
1334 
1335   bool is_suspend_equivalent() const             { return _suspend_equivalent; }
1336 
1337   void set_suspend_equivalent()                  { _suspend_equivalent = true; }
1338   void clear_suspend_equivalent()                { _suspend_equivalent = false; }
1339 
1340   // Thread.stop support
1341   void send_thread_stop(oop throwable);
1342   AsyncRequests clear_special_runtime_exit_condition() {
1343     AsyncRequests x = _special_runtime_exit_condition;
1344     _special_runtime_exit_condition = _no_async_condition;
1345     return x;
1346   }
1347 
1348   // Are any async conditions present?
1349   bool has_async_condition() { return (_special_runtime_exit_condition != _no_async_condition); }
1350 
1351   void check_and_handle_async_exceptions(bool check_unsafe_error = true);
1352 
1353   // these next two are also used for self-suspension and async exception support
1354   void handle_special_runtime_exit_condition(bool check_asyncs = true);
1355 
1356   // Return true if JavaThread has an asynchronous condition or
1357   // if external suspension is requested.
1358   bool has_special_runtime_exit_condition() {
1359     // Because we don't use is_external_suspend_with_lock
1360     // it is possible that we won't see an asynchronous external suspend
1361     // request that has just gotten started, i.e., SR_lock grabbed but
1362     // _external_suspend field change either not made yet or not visible
1363     // yet. However, this is okay because the request is asynchronous and
1364     // we will see the new flag value the next time through. It's also
1365     // possible that the external suspend request is dropped after
1366     // we have checked is_external_suspend(), we will recheck its value
1367     // under SR_lock in java_suspend_self().
1368     return (_special_runtime_exit_condition != _no_async_condition) ||
1369             is_external_suspend() || is_trace_suspend();
1370   }
1371 
1372   void set_pending_unsafe_access_error()          { _special_runtime_exit_condition = _async_unsafe_access_error; }
1373 
1374   inline void set_pending_async_exception(oop e);
1375 
1376   // Fast-locking support
1377   bool is_lock_owned(address adr) const;
1378 
1379   // Accessors for vframe array top
1380   // The linked list of vframe arrays are sorted on sp. This means when we
1381   // unpack the head must contain the vframe array to unpack.
1382   void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
1383   vframeArray* vframe_array_head() const         { return _vframe_array_head;  }
1384 
1385   // Side structure for deferring update of java frame locals until deopt occurs
1386   GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred_locals() const { return _deferred_locals_updates; }
1387   void set_deferred_locals(GrowableArray<jvmtiDeferredLocalVariableSet *>* vf) { _deferred_locals_updates = vf; }
1388 
1389   // These only really exist to make debugging deopt problems simpler
1390 
1391   void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
1392   vframeArray* vframe_array_last() const         { return _vframe_array_last;  }
1393 
1394   // The special resourceMark used during deoptimization
1395 
1396   void set_deopt_mark(DeoptResourceMark* value)  { _deopt_mark = value; }
1397   DeoptResourceMark* deopt_mark(void)            { return _deopt_mark; }
1398 
1399   intptr_t* must_deopt_id()                      { return _must_deopt_id; }
1400   void     set_must_deopt_id(intptr_t* id)       { _must_deopt_id = id; }
1401   void     clear_must_deopt_id()                 { _must_deopt_id = NULL; }
1402 
1403   void set_deopt_compiled_method(CompiledMethod* nm)  { _deopt_nmethod = nm; }
1404   CompiledMethod* deopt_compiled_method()        { return _deopt_nmethod; }
1405 
1406   Method*    callee_target() const               { return _callee_target; }
1407   void set_callee_target  (Method* x)          { _callee_target   = x; }
1408 
1409   // Oop results of vm runtime calls
1410   oop  vm_result() const                         { return _vm_result; }
1411   void set_vm_result  (oop x)                    { _vm_result   = x; }
1412 
1413   Metadata*    vm_result_2() const               { return _vm_result_2; }
1414   void set_vm_result_2  (Metadata* x)          { _vm_result_2   = x; }
1415 
1416   MemRegion deferred_card_mark() const           { return _deferred_card_mark; }
1417   void set_deferred_card_mark(MemRegion mr)      { _deferred_card_mark = mr;   }
1418 
1419 #if INCLUDE_JVMCI
1420   int  pending_deoptimization() const             { return _pending_deoptimization; }
1421   oop  pending_failed_speculation() const         { return _pending_failed_speculation; }
1422   bool adjusting_comp_level() const               { return _adjusting_comp_level; }
1423   void set_adjusting_comp_level(bool b)           { _adjusting_comp_level = b; }
1424   bool has_pending_monitorenter() const           { return _pending_monitorenter; }
1425   void set_pending_monitorenter(bool b)           { _pending_monitorenter = b; }
1426   void set_pending_deoptimization(int reason)     { _pending_deoptimization = reason; }
1427   void set_pending_failed_speculation(oop failed_speculation) { _pending_failed_speculation = failed_speculation; }
1428   void set_pending_transfer_to_interpreter(bool b) { _pending_transfer_to_interpreter = b; }
1429   void set_jvmci_alternate_call_target(address a) { assert(_jvmci._alternate_call_target == NULL, "must be"); _jvmci._alternate_call_target = a; }
1430   void set_jvmci_implicit_exception_pc(address a) { assert(_jvmci._implicit_exception_pc == NULL, "must be"); _jvmci._implicit_exception_pc = a; }
1431 #endif // INCLUDE_JVMCI
1432 
1433   // Exception handling for compiled methods
1434   oop      exception_oop() const                 { return _exception_oop; }
1435   address  exception_pc() const                  { return _exception_pc; }
1436   address  exception_handler_pc() const          { return _exception_handler_pc; }
1437   bool     is_method_handle_return() const       { return _is_method_handle_return == 1; }
1438 
1439   void set_exception_oop(oop o)                  { (void)const_cast<oop&>(_exception_oop = o); }
1440   void set_exception_pc(address a)               { _exception_pc = a; }
1441   void set_exception_handler_pc(address a)       { _exception_handler_pc = a; }
1442   void set_is_method_handle_return(bool value)   { _is_method_handle_return = value ? 1 : 0; }
1443 
1444   void clear_exception_oop_and_pc() {
1445     set_exception_oop(NULL);
1446     set_exception_pc(NULL);
1447   }
1448 
1449   // Stack overflow support
1450   //
1451   //  (small addresses)
1452   //
1453   //  --  <-- stack_end()                   ---
1454   //  |                                      |
1455   //  |  red pages                           |
1456   //  |                                      |
1457   //  --  <-- stack_red_zone_base()          |
1458   //  |                                      |
1459   //  |                                     guard
1460   //  |  yellow pages                       zone
1461   //  |                                      |
1462   //  |                                      |
1463   //  --  <-- stack_yellow_zone_base()       |
1464   //  |                                      |
1465   //  |                                      |
1466   //  |  reserved pages                      |
1467   //  |                                      |
1468   //  --  <-- stack_reserved_zone_base()    ---      ---
1469   //                                                 /|\  shadow     <--  stack_overflow_limit() (somewhere in here)
1470   //                                                  |   zone
1471   //                                                 \|/  size
1472   //  some untouched memory                          ---
1473   //
1474   //
1475   //  --
1476   //  |
1477   //  |  shadow zone
1478   //  |
1479   //  --
1480   //  x    frame n
1481   //  --
1482   //  x    frame n-1
1483   //  x
1484   //  --
1485   //  ...
1486   //
1487   //  --
1488   //  x    frame 0
1489   //  --  <-- stack_base()
1490   //
1491   //  (large addresses)
1492   //
1493 
1494  private:
1495   // These values are derived from flags StackRedPages, StackYellowPages,
1496   // StackReservedPages and StackShadowPages. The zone size is determined
1497   // ergonomically if page_size > 4K.
1498   static size_t _stack_red_zone_size;
1499   static size_t _stack_yellow_zone_size;
1500   static size_t _stack_reserved_zone_size;
1501   static size_t _stack_shadow_zone_size;
1502  public:
1503   inline size_t stack_available(address cur_sp);
1504 
1505   static size_t stack_red_zone_size() {
1506     assert(_stack_red_zone_size > 0, "Don't call this before the field is initialized.");
1507     return _stack_red_zone_size;
1508   }
1509   static void set_stack_red_zone_size(size_t s) {
1510     assert(is_aligned(s, os::vm_page_size()),
1511            "We can not protect if the red zone size is not page aligned.");
1512     assert(_stack_red_zone_size == 0, "This should be called only once.");
1513     _stack_red_zone_size = s;
1514   }
1515   address stack_red_zone_base() {
1516     return (address)(stack_end() + stack_red_zone_size());
1517   }
1518   bool in_stack_red_zone(address a) {
1519     return a <= stack_red_zone_base() && a >= stack_end();
1520   }
1521 
1522   static size_t stack_yellow_zone_size() {
1523     assert(_stack_yellow_zone_size > 0, "Don't call this before the field is initialized.");
1524     return _stack_yellow_zone_size;
1525   }
1526   static void set_stack_yellow_zone_size(size_t s) {
1527     assert(is_aligned(s, os::vm_page_size()),
1528            "We can not protect if the yellow zone size is not page aligned.");
1529     assert(_stack_yellow_zone_size == 0, "This should be called only once.");
1530     _stack_yellow_zone_size = s;
1531   }
1532 
1533   static size_t stack_reserved_zone_size() {
1534     // _stack_reserved_zone_size may be 0. This indicates the feature is off.
1535     return _stack_reserved_zone_size;
1536   }
1537   static void set_stack_reserved_zone_size(size_t s) {
1538     assert(is_aligned(s, os::vm_page_size()),
1539            "We can not protect if the reserved zone size is not page aligned.");
1540     assert(_stack_reserved_zone_size == 0, "This should be called only once.");
1541     _stack_reserved_zone_size = s;
1542   }
1543   address stack_reserved_zone_base() {
1544     return (address)(stack_end() +
1545                      (stack_red_zone_size() + stack_yellow_zone_size() + stack_reserved_zone_size()));
1546   }
1547   bool in_stack_reserved_zone(address a) {
1548     return (a <= stack_reserved_zone_base()) &&
1549            (a >= (address)((intptr_t)stack_reserved_zone_base() - stack_reserved_zone_size()));
1550   }
1551 
1552   static size_t stack_yellow_reserved_zone_size() {
1553     return _stack_yellow_zone_size + _stack_reserved_zone_size;
1554   }
1555   bool in_stack_yellow_reserved_zone(address a) {
1556     return (a <= stack_reserved_zone_base()) && (a >= stack_red_zone_base());
1557   }
1558 
1559   // Size of red + yellow + reserved zones.
1560   static size_t stack_guard_zone_size() {
1561     return stack_red_zone_size() + stack_yellow_reserved_zone_size();
1562   }
1563 
1564   static size_t stack_shadow_zone_size() {
1565     assert(_stack_shadow_zone_size > 0, "Don't call this before the field is initialized.");
1566     return _stack_shadow_zone_size;
1567   }
1568   static void set_stack_shadow_zone_size(size_t s) {
1569     // The shadow area is not allocated or protected, so
1570     // it needs not be page aligned.
1571     // But the stack bang currently assumes that it is a
1572     // multiple of page size. This guarantees that the bang
1573     // loop touches all pages in the shadow zone.
1574     // This can be guaranteed differently, as well.  E.g., if
1575     // the page size is a multiple of 4K, banging in 4K steps
1576     // suffices to touch all pages. (Some pages are banged
1577     // several times, though.)
1578     assert(is_aligned(s, os::vm_page_size()),
1579            "Stack bang assumes multiple of page size.");
1580     assert(_stack_shadow_zone_size == 0, "This should be called only once.");
1581     _stack_shadow_zone_size = s;
1582   }
1583 
1584   void create_stack_guard_pages();
1585   void remove_stack_guard_pages();
1586 
1587   void enable_stack_reserved_zone();
1588   void disable_stack_reserved_zone();
1589   void enable_stack_yellow_reserved_zone();
1590   void disable_stack_yellow_reserved_zone();
1591   void enable_stack_red_zone();
1592   void disable_stack_red_zone();
1593 
1594   inline bool stack_guard_zone_unused();
1595   inline bool stack_yellow_reserved_zone_disabled();
1596   inline bool stack_reserved_zone_disabled();
1597   inline bool stack_guards_enabled();
1598 
1599   address reserved_stack_activation() const { return _reserved_stack_activation; }
1600   void set_reserved_stack_activation(address addr) {
1601     assert(_reserved_stack_activation == stack_base()
1602             || _reserved_stack_activation == NULL
1603             || addr == stack_base(), "Must not be set twice");
1604     _reserved_stack_activation = addr;
1605   }
1606 
1607   // Attempt to reguard the stack after a stack overflow may have occurred.
1608   // Returns true if (a) guard pages are not needed on this thread, (b) the
1609   // pages are already guarded, or (c) the pages were successfully reguarded.
1610   // Returns false if there is not enough stack space to reguard the pages, in
1611   // which case the caller should unwind a frame and try again.  The argument
1612   // should be the caller's (approximate) sp.
1613   bool reguard_stack(address cur_sp);
1614   // Similar to above but see if current stackpoint is out of the guard area
1615   // and reguard if possible.
1616   bool reguard_stack(void);
1617 
1618   address stack_overflow_limit() { return _stack_overflow_limit; }
1619   void set_stack_overflow_limit() {
1620     _stack_overflow_limit =
1621       stack_end() + MAX2(JavaThread::stack_guard_zone_size(), JavaThread::stack_shadow_zone_size());
1622   }
1623 
1624   // Misc. accessors/mutators
1625   void set_do_not_unlock(void)                   { _do_not_unlock_if_synchronized = true; }
1626   void clr_do_not_unlock(void)                   { _do_not_unlock_if_synchronized = false; }
1627   bool do_not_unlock(void)                       { return _do_not_unlock_if_synchronized; }
1628 
1629 #ifndef PRODUCT
1630   void record_jump(address target, address instr, const char* file, int line);
1631 #endif // PRODUCT
1632 
1633   // For assembly stub generation
1634   static ByteSize threadObj_offset()             { return byte_offset_of(JavaThread, _threadObj); }
1635 #ifndef PRODUCT
1636   static ByteSize jmp_ring_index_offset()        { return byte_offset_of(JavaThread, _jmp_ring_index); }
1637   static ByteSize jmp_ring_offset()              { return byte_offset_of(JavaThread, _jmp_ring); }
1638 #endif // PRODUCT
1639   static ByteSize jni_environment_offset()       { return byte_offset_of(JavaThread, _jni_environment); }
1640   static ByteSize pending_jni_exception_check_fn_offset() {
1641     return byte_offset_of(JavaThread, _pending_jni_exception_check_fn);
1642   }
1643   static ByteSize last_Java_sp_offset() {
1644     return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
1645   }
1646   static ByteSize last_Java_pc_offset() {
1647     return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
1648   }
1649   static ByteSize frame_anchor_offset() {
1650     return byte_offset_of(JavaThread, _anchor);
1651   }
1652   static ByteSize callee_target_offset()         { return byte_offset_of(JavaThread, _callee_target); }
1653   static ByteSize vm_result_offset()             { return byte_offset_of(JavaThread, _vm_result); }
1654   static ByteSize vm_result_2_offset()           { return byte_offset_of(JavaThread, _vm_result_2); }
1655   static ByteSize thread_state_offset()          { return byte_offset_of(JavaThread, _thread_state); }
1656   static ByteSize saved_exception_pc_offset()    { return byte_offset_of(JavaThread, _saved_exception_pc); }
1657   static ByteSize osthread_offset()              { return byte_offset_of(JavaThread, _osthread); }
1658 #if INCLUDE_JVMCI
1659   static ByteSize pending_deoptimization_offset() { return byte_offset_of(JavaThread, _pending_deoptimization); }
1660   static ByteSize pending_monitorenter_offset()  { return byte_offset_of(JavaThread, _pending_monitorenter); }
1661   static ByteSize pending_failed_speculation_offset() { return byte_offset_of(JavaThread, _pending_failed_speculation); }
1662   static ByteSize jvmci_alternate_call_target_offset() { return byte_offset_of(JavaThread, _jvmci._alternate_call_target); }
1663   static ByteSize jvmci_implicit_exception_pc_offset() { return byte_offset_of(JavaThread, _jvmci._implicit_exception_pc); }
1664   static ByteSize jvmci_counters_offset()        { return byte_offset_of(JavaThread, _jvmci_counters); }
1665 #endif // INCLUDE_JVMCI
1666   static ByteSize exception_oop_offset()         { return byte_offset_of(JavaThread, _exception_oop); }
1667   static ByteSize exception_pc_offset()          { return byte_offset_of(JavaThread, _exception_pc); }
1668   static ByteSize exception_handler_pc_offset()  { return byte_offset_of(JavaThread, _exception_handler_pc); }
1669   static ByteSize stack_overflow_limit_offset()  { return byte_offset_of(JavaThread, _stack_overflow_limit); }
1670   static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); }
1671   static ByteSize stack_guard_state_offset()     { return byte_offset_of(JavaThread, _stack_guard_state); }
1672   static ByteSize reserved_stack_activation_offset() { return byte_offset_of(JavaThread, _reserved_stack_activation); }
1673   static ByteSize suspend_flags_offset()         { return byte_offset_of(JavaThread, _suspend_flags); }
1674 
1675   static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
1676   static ByteSize should_post_on_exceptions_flag_offset() {
1677     return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
1678   }
1679 
1680 #if INCLUDE_ALL_GCS
1681   static ByteSize satb_mark_queue_offset()       { return byte_offset_of(JavaThread, _satb_mark_queue); }
1682   static ByteSize dirty_card_queue_offset()      { return byte_offset_of(JavaThread, _dirty_card_queue); }
1683 #endif // INCLUDE_ALL_GCS
1684 
1685   // Returns the jni environment for this thread
1686   JNIEnv* jni_environment()                      { return &_jni_environment; }
1687 
1688   static JavaThread* thread_from_jni_environment(JNIEnv* env) {
1689     JavaThread *thread_from_jni_env = (JavaThread*)((intptr_t)env - in_bytes(jni_environment_offset()));
1690     // Only return NULL if thread is off the thread list; starting to
1691     // exit should not return NULL.
1692     if (thread_from_jni_env->is_terminated()) {
1693       thread_from_jni_env->block_if_vm_exited();
1694       return NULL;
1695     } else {
1696       return thread_from_jni_env;
1697     }
1698   }
1699 
1700   // JNI critical regions. These can nest.
1701   bool in_critical()    { return _jni_active_critical > 0; }
1702   bool in_last_critical()  { return _jni_active_critical == 1; }
1703   void enter_critical() {
1704     assert(Thread::current() == this ||
1705            (Thread::current()->is_VM_thread() &&
1706            SafepointSynchronize::is_synchronizing()),
1707            "this must be current thread or synchronizing");
1708     _jni_active_critical++;
1709   }
1710   void exit_critical() {
1711     assert(Thread::current() == this, "this must be current thread");
1712     _jni_active_critical--;
1713     assert(_jni_active_critical >= 0, "JNI critical nesting problem?");
1714   }
1715 
1716   // Checked JNI: is the programmer required to check for exceptions, if so specify
1717   // which function name. Returning to a Java frame should implicitly clear the
1718   // pending check, this is done for Native->Java transitions (i.e. user JNI code).
1719   // VM->Java transistions are not cleared, it is expected that JNI code enclosed
1720   // within ThreadToNativeFromVM makes proper exception checks (i.e. VM internal).
1721   bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != NULL; }
1722   void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = NULL; }
1723   const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; }
1724   void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; }
1725 
1726   // For deadlock detection
1727   int depth_first_number() { return _depth_first_number; }
1728   void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
1729 
1730  private:
1731   void set_monitor_chunks(MonitorChunk* monitor_chunks) { _monitor_chunks = monitor_chunks; }
1732 
1733  public:
1734   MonitorChunk* monitor_chunks() const           { return _monitor_chunks; }
1735   void add_monitor_chunk(MonitorChunk* chunk);
1736   void remove_monitor_chunk(MonitorChunk* chunk);
1737   bool in_deopt_handler() const                  { return _in_deopt_handler > 0; }
1738   void inc_in_deopt_handler()                    { _in_deopt_handler++; }
1739   void dec_in_deopt_handler() {
1740     assert(_in_deopt_handler > 0, "mismatched deopt nesting");
1741     if (_in_deopt_handler > 0) { // robustness
1742       _in_deopt_handler--;
1743     }
1744   }
1745 
1746  private:
1747   void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
1748 
1749  public:
1750 
1751   // Frame iteration; calls the function f for all frames on the stack
1752   void frames_do(void f(frame*, const RegisterMap*));
1753 
1754   // Memory operations
1755   void oops_do(OopClosure* f, CodeBlobClosure* cf);
1756 
1757   // Sweeper operations
1758   virtual void nmethods_do(CodeBlobClosure* cf);
1759 
1760   // RedefineClasses Support
1761   void metadata_do(void f(Metadata*));
1762 
1763   // Misc. operations
1764   char* name() const { return (char*)get_thread_name(); }
1765   void print_on(outputStream* st) const;
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 #if INCLUDE_ALL_GCS
1956   // SATB marking queue support
1957   SATBMarkQueue& satb_mark_queue() { return _satb_mark_queue; }
1958   static SATBMarkQueueSet& satb_mark_queue_set() {
1959     return _satb_mark_queue_set;
1960   }
1961 
1962   // Dirty card queue support
1963   DirtyCardQueue& dirty_card_queue() { return _dirty_card_queue; }
1964   static DirtyCardQueueSet& dirty_card_queue_set() {
1965     return _dirty_card_queue_set;
1966   }
1967 #endif // INCLUDE_ALL_GCS
1968 
1969   // This method initializes the SATB and dirty card queues before a
1970   // JavaThread is added to the Java thread list. Right now, we don't
1971   // have to do anything to the dirty card queue (it should have been
1972   // activated when the thread was created), but we have to activate
1973   // the SATB queue if the thread is created while a marking cycle is
1974   // in progress. The activation / de-activation of the SATB queues at
1975   // the beginning / end of a marking cycle is done during safepoints
1976   // so we have to make sure this method is called outside one to be
1977   // able to safely read the active field of the SATB queue set. Right
1978   // now, it is called just before the thread is added to the Java
1979   // thread list in the Threads::add() method. That method is holding
1980   // the Threads_lock which ensures we are outside a safepoint. We
1981   // cannot do the obvious and set the active field of the SATB queue
1982   // when the thread is created given that, in some cases, safepoints
1983   // might happen between the JavaThread constructor being called and the
1984   // thread being added to the Java thread list (an example of this is
1985   // when the structure for the DestroyJavaVM thread is created).
1986 #if INCLUDE_ALL_GCS
1987   void initialize_queues();
1988 #else  // INCLUDE_ALL_GCS
1989   void initialize_queues() { }
1990 #endif // INCLUDE_ALL_GCS
1991 
1992   // Machine dependent stuff
1993 #include OS_CPU_HEADER(thread)
1994 
1995  public:
1996   void set_blocked_on_compilation(bool value) {
1997     _blocked_on_compilation = value;
1998   }
1999 
2000   bool blocked_on_compilation() {
2001     return _blocked_on_compilation;
2002   }
2003  protected:
2004   bool         _blocked_on_compilation;
2005 
2006 
2007   // JSR166 per-thread parker
2008  private:
2009   Parker*    _parker;
2010  public:
2011   Parker*     parker() { return _parker; }
2012 
2013   // Biased locking support
2014  private:
2015   GrowableArray<MonitorInfo*>* _cached_monitor_info;
2016  public:
2017   GrowableArray<MonitorInfo*>* cached_monitor_info() { return _cached_monitor_info; }
2018   void set_cached_monitor_info(GrowableArray<MonitorInfo*>* info) { _cached_monitor_info = info; }
2019 
2020   // clearing/querying jni attach status
2021   bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; }
2022   bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
2023   inline void set_done_attaching_via_jni();
2024 };
2025 
2026 // Inline implementation of JavaThread::current
2027 inline JavaThread* JavaThread::current() {
2028   Thread* thread = Thread::current();
2029   assert(thread->is_Java_thread(), "just checking");
2030   return (JavaThread*)thread;
2031 }
2032 
2033 inline CompilerThread* JavaThread::as_CompilerThread() {
2034   assert(is_Compiler_thread(), "just checking");
2035   return (CompilerThread*)this;
2036 }
2037 
2038 // Dedicated thread to sweep the code cache
2039 class CodeCacheSweeperThread : public JavaThread {
2040   CompiledMethod*       _scanned_compiled_method; // nmethod being scanned by the sweeper
2041  public:
2042   CodeCacheSweeperThread();
2043   // Track the nmethod currently being scanned by the sweeper
2044   void set_scanned_compiled_method(CompiledMethod* cm) {
2045     assert(_scanned_compiled_method == NULL || cm == NULL, "should reset to NULL before writing a new value");
2046     _scanned_compiled_method = cm;
2047   }
2048 
2049   // Hide sweeper thread from external view.
2050   bool is_hidden_from_external_view() const { return true; }
2051 
2052   bool is_Code_cache_sweeper_thread() const { return true; }
2053 
2054   // Prevent GC from unloading _scanned_compiled_method
2055   void oops_do(OopClosure* f, CodeBlobClosure* cf);
2056   void nmethods_do(CodeBlobClosure* cf);
2057 };
2058 
2059 // A thread used for Compilation.
2060 class CompilerThread : public JavaThread {
2061   friend class VMStructs;
2062  private:
2063   CompilerCounters* _counters;
2064 
2065   ciEnv*                _env;
2066   CompileLog*           _log;
2067   CompileTask* volatile _task;  // print_threads_compiling can read this concurrently.
2068   CompileQueue*         _queue;
2069   BufferBlob*           _buffer_blob;
2070 
2071   AbstractCompiler*     _compiler;
2072 
2073  public:
2074 
2075   static CompilerThread* current();
2076 
2077   CompilerThread(CompileQueue* queue, CompilerCounters* counters);
2078 
2079   bool is_Compiler_thread() const                { return true; }
2080 
2081   virtual bool can_call_java() const;
2082 
2083   // Hide native compiler threads from external view.
2084   bool is_hidden_from_external_view() const      { return !can_call_java(); }
2085 
2086   void set_compiler(AbstractCompiler* c)         { _compiler = c; }
2087   AbstractCompiler* compiler() const             { return _compiler; }
2088 
2089   CompileQueue* queue()        const             { return _queue; }
2090   CompilerCounters* counters() const             { return _counters; }
2091 
2092   // Get/set the thread's compilation environment.
2093   ciEnv*        env()                            { return _env; }
2094   void          set_env(ciEnv* env)              { _env = env; }
2095 
2096   BufferBlob*   get_buffer_blob() const          { return _buffer_blob; }
2097   void          set_buffer_blob(BufferBlob* b)   { _buffer_blob = b; }
2098 
2099   // Get/set the thread's logging information
2100   CompileLog*   log()                            { return _log; }
2101   void          init_log(CompileLog* log) {
2102     // Set once, for good.
2103     assert(_log == NULL, "set only once");
2104     _log = log;
2105   }
2106 
2107 #ifndef PRODUCT
2108  private:
2109   IdealGraphPrinter *_ideal_graph_printer;
2110  public:
2111   IdealGraphPrinter *ideal_graph_printer()           { return _ideal_graph_printer; }
2112   void set_ideal_graph_printer(IdealGraphPrinter *n) { _ideal_graph_printer = n; }
2113 #endif
2114 
2115   // Get/set the thread's current task
2116   CompileTask* task()                      { return _task; }
2117   void         set_task(CompileTask* task) { _task = task; }
2118 };
2119 
2120 inline CompilerThread* CompilerThread::current() {
2121   return JavaThread::current()->as_CompilerThread();
2122 }
2123 
2124 // The active thread queue. It also keeps track of the current used
2125 // thread priorities.
2126 class Threads: AllStatic {
2127   friend class VMStructs;
2128  private:
2129   static JavaThread* _thread_list;
2130   static int         _number_of_threads;
2131   static int         _number_of_non_daemon_threads;
2132   static int         _return_code;
2133   static int         _thread_claim_parity;
2134 #ifdef ASSERT
2135   static bool        _vm_complete;
2136 #endif
2137 
2138   static void initialize_java_lang_classes(JavaThread* main_thread, TRAPS);
2139   static void initialize_jsr292_core_classes(TRAPS);
2140 
2141  public:
2142   // Thread management
2143   // force_daemon is a concession to JNI, where we may need to add a
2144   // thread to the thread list before allocating its thread object
2145   static void add(JavaThread* p, bool force_daemon = false);
2146   static void remove(JavaThread* p);
2147   static void threads_do(ThreadClosure* tc);
2148   static void possibly_parallel_threads_do(bool is_par, ThreadClosure* tc);
2149 
2150   // Initializes the vm and creates the vm thread
2151   static jint create_vm(JavaVMInitArgs* args, bool* canTryAgain);
2152   static void convert_vm_init_libraries_to_agents();
2153   static void create_vm_init_libraries();
2154   static void create_vm_init_agents();
2155   static void shutdown_vm_agents();
2156   static bool destroy_vm();
2157   // Supported VM versions via JNI
2158   // Includes JNI_VERSION_1_1
2159   static jboolean is_supported_jni_version_including_1_1(jint version);
2160   // Does not include JNI_VERSION_1_1
2161   static jboolean is_supported_jni_version(jint version);
2162 
2163   // The "thread claim parity" provides a way for threads to be claimed
2164   // by parallel worker tasks.
2165   //
2166   // Each thread contains a a "parity" field. A task will claim the
2167   // thread only if its parity field is the same as the global parity,
2168   // which is updated by calling change_thread_claim_parity().
2169   //
2170   // For this to work change_thread_claim_parity() needs to be called
2171   // exactly once in sequential code before starting parallel tasks
2172   // that should claim threads.
2173   //
2174   // New threads get their parity set to 0 and change_thread_claim_parity()
2175   // never set the global parity to 0.
2176   static int thread_claim_parity() { return _thread_claim_parity; }
2177   static void change_thread_claim_parity();
2178   static void assert_all_threads_claimed() NOT_DEBUG_RETURN;
2179 
2180   // Apply "f->do_oop" to all root oops in all threads.
2181   // This version may only be called by sequential code.
2182   static void oops_do(OopClosure* f, CodeBlobClosure* cf);
2183   // This version may be called by sequential or parallel code.
2184   static void possibly_parallel_oops_do(bool is_par, OopClosure* f, CodeBlobClosure* cf);
2185   // This creates a list of GCTasks, one per thread.
2186   static void create_thread_roots_tasks(GCTaskQueue* q);
2187   // This creates a list of GCTasks, one per thread, for marking objects.
2188   static void create_thread_roots_marking_tasks(GCTaskQueue* q);
2189 
2190   // Apply "f->do_oop" to roots in all threads that
2191   // are part of compiled frames
2192   static void compiled_frame_oops_do(OopClosure* f, CodeBlobClosure* cf);
2193 
2194   static void convert_hcode_pointers();
2195   static void restore_hcode_pointers();
2196 
2197   // Sweeper
2198   static void nmethods_do(CodeBlobClosure* cf);
2199 
2200   // RedefineClasses support
2201   static void metadata_do(void f(Metadata*));
2202   static void metadata_handles_do(void f(Metadata*));
2203 
2204 #ifdef ASSERT
2205   static bool is_vm_complete() { return _vm_complete; }
2206 #endif
2207 
2208   // Verification
2209   static void verify();
2210   static void print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks);
2211   static void print(bool print_stacks, bool internal_format) {
2212     // this function is only used by debug.cpp
2213     print_on(tty, print_stacks, internal_format, false /* no concurrent lock printed */);
2214   }
2215   static void print_on_error(outputStream* st, Thread* current, char* buf, int buflen);
2216   static void print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
2217                              int buflen, bool* found_current);
2218   static void print_threads_compiling(outputStream* st, char* buf, int buflen);
2219 
2220   // Get Java threads that are waiting to enter a monitor.
2221   static GrowableArray<JavaThread*>* get_pending_threads(ThreadsList * t_list,
2222                                                          int count, address monitor);
2223 
2224   // Get owning Java thread from the monitor's owner field.
2225   static JavaThread *owning_thread_from_monitor_owner(ThreadsList * t_list,
2226                                                       address owner);
2227 
2228   // Number of threads on the active threads list
2229   static int number_of_threads()                 { return _number_of_threads; }
2230   // Number of non-daemon threads on the active threads list
2231   static int number_of_non_daemon_threads()      { return _number_of_non_daemon_threads; }
2232 
2233   // Deoptimizes all frames tied to marked nmethods
2234   static void deoptimized_wrt_marked_nmethods();
2235 };
2236 
2237 
2238 // Thread iterator
2239 class ThreadClosure: public StackObj {
2240  public:
2241   virtual void do_thread(Thread* thread) = 0;
2242 };
2243 
2244 class SignalHandlerMark: public StackObj {
2245  private:
2246   Thread* _thread;
2247  public:
2248   SignalHandlerMark(Thread* t) {
2249     _thread = t;
2250     if (_thread) _thread->enter_signal_handler();
2251   }
2252   ~SignalHandlerMark() {
2253     if (_thread) _thread->leave_signal_handler();
2254     _thread = NULL;
2255   }
2256 };
2257 
2258 
2259 #endif // SHARE_VM_RUNTIME_THREAD_HPP