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