rev 57095 : [mq]: use
rev 57096 : [mq]: trailing_semi

   1 /*
   2  * Copyright (c) 1997, 2019, 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_RUNTIME_THREAD_HPP
  26 #define SHARE_RUNTIME_THREAD_HPP
  27 
  28 #include "jni.h"
  29 #include "code/compiledMethod.hpp"
  30 #include "gc/shared/gcThreadLocalData.hpp"
  31 #include "gc/shared/threadLocalAllocBuffer.hpp"
  32 #include "memory/allocation.hpp"
  33 #include "oops/oop.hpp"
  34 #include "prims/jvmtiExport.hpp"
  35 #include "runtime/frame.hpp"
  36 #include "runtime/globals.hpp"
  37 #include "runtime/handshake.hpp"
  38 #include "runtime/javaFrameAnchor.hpp"
  39 #include "runtime/jniHandles.hpp"
  40 #include "runtime/mutexLocker.hpp"
  41 #include "runtime/os.hpp"
  42 #include "runtime/osThread.hpp"
  43 #include "runtime/park.hpp"
  44 #include "runtime/stubRoutines.hpp"
  45 #include "runtime/threadHeapSampler.hpp"
  46 #include "runtime/threadLocalStorage.hpp"
  47 #include "runtime/threadStatisticalInfo.hpp"
  48 #include "runtime/unhandledOops.hpp"
  49 #include "utilities/align.hpp"
  50 #include "utilities/exceptions.hpp"
  51 #include "utilities/macros.hpp"
  52 #ifdef ZERO
  53 # include "stack_zero.hpp"
  54 #endif
  55 #if INCLUDE_JFR
  56 #include "jfr/support/jfrThreadExtension.hpp"
  57 #endif
  58 
  59 
  60 class SafeThreadsListPtr;
  61 class ThreadSafepointState;
  62 class ThreadsList;
  63 class ThreadsSMRSupport;
  64 
  65 class JvmtiRawMonitor;
  66 class JvmtiThreadState;
  67 class ThreadStatistics;
  68 class ConcurrentLocksDump;
  69 class ParkEvent;
  70 class Parker;
  71 class MonitorInfo;
  72 
  73 class ciEnv;
  74 class CompileThread;
  75 class CompileLog;
  76 class CompileTask;
  77 class CompileQueue;
  78 class CompilerCounters;
  79 
  80 class vframeArray;
  81 class vframe;
  82 class javaVFrame;
  83 
  84 class DeoptResourceMark;
  85 class jvmtiDeferredLocalVariableSet;
  86 
  87 class ThreadClosure;
  88 class ICRefillVerifier;
  89 class IdealGraphPrinter;
  90 
  91 class JVMCIEnv;
  92 class JVMCIPrimitiveArray;
  93 
  94 class Metadata;
  95 class ResourceArea;
  96 
  97 DEBUG_ONLY(class ResourceMark;)
  98 
  99 class WorkerThread;
 100 
 101 // Class hierarchy
 102 // - Thread
 103 //   - JavaThread
 104 //     - various subclasses eg CompilerThread, ServiceThread
 105 //   - NonJavaThread
 106 //     - NamedThread
 107 //       - VMThread
 108 //       - ConcurrentGCThread
 109 //       - WorkerThread
 110 //         - GangWorker
 111 //     - WatcherThread
 112 //     - JfrThreadSampler
 113 //
 114 // All Thread subclasses must be either JavaThread or NonJavaThread.
 115 // This means !t->is_Java_thread() iff t is a NonJavaThread, or t is
 116 // a partially constructed/destroyed Thread.
 117 
 118 // Thread execution sequence and actions:
 119 // All threads:
 120 //  - thread_native_entry  // per-OS native entry point
 121 //    - stack initialization
 122 //    - other OS-level initialization (signal masks etc)
 123 //    - handshake with creating thread (if not started suspended)
 124 //    - this->call_run()  // common shared entry point
 125 //      - shared common initialization
 126 //      - this->pre_run()  // virtual per-thread-type initialization
 127 //      - this->run()      // virtual per-thread-type "main" logic
 128 //      - shared common tear-down
 129 //      - this->post_run()  // virtual per-thread-type tear-down
 130 //      - // 'this' no longer referenceable
 131 //    - OS-level tear-down (minimal)
 132 //    - final logging
 133 //
 134 // For JavaThread:
 135 //   - this->run()  // virtual but not normally overridden
 136 //     - this->thread_main_inner()  // extra call level to ensure correct stack calculations
 137 //       - this->entry_point()  // set differently for each kind of JavaThread
 138 
 139 class Thread: public ThreadShadow {
 140   friend class VMStructs;
 141   friend class JVMCIVMStructs;
 142  private:
 143 
 144 #ifndef USE_LIBRARY_BASED_TLS_ONLY
 145   // Current thread is maintained as a thread-local variable
 146   static THREAD_LOCAL Thread* _thr_current;
 147 #endif
 148 
 149   // Thread local data area available to the GC. The internal
 150   // structure and contents of this data area is GC-specific.
 151   // Only GC and GC barrier code should access this data area.
 152   GCThreadLocalData _gc_data;
 153 
 154  public:
 155   static ByteSize gc_data_offset() {
 156     return byte_offset_of(Thread, _gc_data);
 157   }
 158 
 159   template <typename T> T* gc_data() {
 160     STATIC_ASSERT(sizeof(T) <= sizeof(_gc_data));
 161     return reinterpret_cast<T*>(&_gc_data);
 162   }
 163 
 164   // Exception handling
 165   // (Note: _pending_exception and friends are in ThreadShadow)
 166   //oop       _pending_exception;                // pending exception for current thread
 167   // const char* _exception_file;                   // file information for exception (debugging only)
 168   // int         _exception_line;                   // line information for exception (debugging only)
 169  protected:
 170 
 171   DEBUG_ONLY(static Thread* _starting_thread;)
 172 
 173   // Support for forcing alignment of thread objects for biased locking
 174   void*       _real_malloc_address;
 175 
 176   // JavaThread lifecycle support:
 177   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
 178   friend class ScanHazardPtrGatherProtectedThreadsClosure;  // for cmpxchg_threads_hazard_ptr(), get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
 179   friend class ScanHazardPtrGatherThreadsListClosure;  // for get_threads_hazard_ptr(), untag_hazard_ptr() access
 180   friend class ScanHazardPtrPrintMatchingThreadsClosure;  // for get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
 181   friend class ThreadsSMRSupport;  // for _nested_threads_hazard_ptr_cnt, _threads_hazard_ptr, _threads_list_ptr access
 182 
 183   ThreadsList* volatile _threads_hazard_ptr;
 184   SafeThreadsListPtr*   _threads_list_ptr;
 185   ThreadsList*          cmpxchg_threads_hazard_ptr(ThreadsList* exchange_value, ThreadsList* compare_value);
 186   ThreadsList*          get_threads_hazard_ptr();
 187   void                  set_threads_hazard_ptr(ThreadsList* new_list);
 188   static bool           is_hazard_ptr_tagged(ThreadsList* list) {
 189     return (intptr_t(list) & intptr_t(1)) == intptr_t(1);
 190   }
 191   static ThreadsList*   tag_hazard_ptr(ThreadsList* list) {
 192     return (ThreadsList*)(intptr_t(list) | intptr_t(1));
 193   }
 194   static ThreadsList*   untag_hazard_ptr(ThreadsList* list) {
 195     return (ThreadsList*)(intptr_t(list) & ~intptr_t(1));
 196   }
 197   // This field is enabled via -XX:+EnableThreadSMRStatistics:
 198   uint _nested_threads_hazard_ptr_cnt;
 199   void dec_nested_threads_hazard_ptr_cnt() {
 200     assert(_nested_threads_hazard_ptr_cnt != 0, "mismatched {dec,inc}_nested_threads_hazard_ptr_cnt()");
 201     _nested_threads_hazard_ptr_cnt--;
 202   }
 203   void inc_nested_threads_hazard_ptr_cnt() {
 204     _nested_threads_hazard_ptr_cnt++;
 205   }
 206   uint nested_threads_hazard_ptr_cnt() {
 207     return _nested_threads_hazard_ptr_cnt;
 208   }
 209 
 210  public:
 211   void* operator new(size_t size) throw() { return allocate(size, true); }
 212   void* operator new(size_t size, const std::nothrow_t& nothrow_constant) throw() {
 213     return allocate(size, false); }
 214   void  operator delete(void* p);
 215 
 216  protected:
 217   static void* allocate(size_t size, bool throw_excpt, MEMFLAGS flags = mtThread);
 218  private:
 219 
 220   // ***************************************************************
 221   // Suspend and resume support
 222   // ***************************************************************
 223   //
 224   // VM suspend/resume no longer exists - it was once used for various
 225   // things including safepoints but was deprecated and finally removed
 226   // in Java 7. Because VM suspension was considered "internal" Java-level
 227   // suspension was considered "external", and this legacy naming scheme
 228   // remains.
 229   //
 230   // External suspend/resume requests come from JVM_SuspendThread,
 231   // JVM_ResumeThread, JVMTI SuspendThread, and finally JVMTI
 232   // ResumeThread. External
 233   // suspend requests cause _external_suspend to be set and external
 234   // resume requests cause _external_suspend to be cleared.
 235   // External suspend requests do not nest on top of other external
 236   // suspend requests. The higher level APIs reject suspend requests
 237   // for already suspended threads.
 238   //
 239   // The external_suspend
 240   // flag is checked by has_special_runtime_exit_condition() and java thread
 241   // will self-suspend when handle_special_runtime_exit_condition() is
 242   // called. Most uses of the _thread_blocked state in JavaThreads are
 243   // considered the same as being externally suspended; if the blocking
 244   // condition lifts, the JavaThread will self-suspend. Other places
 245   // where VM checks for external_suspend include:
 246   //   + mutex granting (do not enter monitors when thread is suspended)
 247   //   + state transitions from _thread_in_native
 248   //
 249   // In general, java_suspend() does not wait for an external suspend
 250   // request to complete. When it returns, the only guarantee is that
 251   // the _external_suspend field is true.
 252   //
 253   // wait_for_ext_suspend_completion() is used to wait for an external
 254   // suspend request to complete. External suspend requests are usually
 255   // followed by some other interface call that requires the thread to
 256   // be quiescent, e.g., GetCallTrace(). By moving the "wait time" into
 257   // the interface that requires quiescence, we give the JavaThread a
 258   // chance to self-suspend before we need it to be quiescent. This
 259   // improves overall suspend/query performance.
 260   //
 261   // _suspend_flags controls the behavior of java_ suspend/resume.
 262   // It must be set under the protection of SR_lock. Read from the flag is
 263   // OK without SR_lock as long as the value is only used as a hint.
 264   // (e.g., check _external_suspend first without lock and then recheck
 265   // inside SR_lock and finish the suspension)
 266   //
 267   // _suspend_flags is also overloaded for other "special conditions" so
 268   // that a single check indicates whether any special action is needed
 269   // eg. for async exceptions.
 270   // -------------------------------------------------------------------
 271   // Notes:
 272   // 1. The suspend/resume logic no longer uses ThreadState in OSThread
 273   // but we still update its value to keep other part of the system (mainly
 274   // JVMTI) happy. ThreadState is legacy code (see notes in
 275   // osThread.hpp).
 276   //
 277   // 2. It would be more natural if set_external_suspend() is private and
 278   // part of java_suspend(), but that probably would affect the suspend/query
 279   // performance. Need more investigation on this.
 280 
 281   // suspend/resume lock: used for self-suspend
 282   Monitor* _SR_lock;
 283 
 284  protected:
 285   enum SuspendFlags {
 286     // NOTE: avoid using the sign-bit as cc generates different test code
 287     //       when the sign-bit is used, and sometimes incorrectly - see CR 6398077
 288 
 289     _external_suspend       = 0x20000000U, // thread is asked to self suspend
 290     _ext_suspended          = 0x40000000U, // thread has self-suspended
 291 
 292     _has_async_exception    = 0x00000001U, // there is a pending async exception
 293     _critical_native_unlock = 0x00000002U, // Must call back to unlock JNI critical lock
 294 
 295     _trace_flag             = 0x00000004U  // call tracing backend
 296   };
 297 
 298   // various suspension related flags - atomically updated
 299   // overloaded for async exception checking in check_special_condition_for_native_trans.
 300   volatile uint32_t _suspend_flags;
 301 
 302  private:
 303   int _num_nested_signal;
 304 
 305   DEBUG_ONLY(bool _suspendible_thread;)
 306 
 307  public:
 308   void enter_signal_handler() { _num_nested_signal++; }
 309   void leave_signal_handler() { _num_nested_signal--; }
 310   bool is_inside_signal_handler() const { return _num_nested_signal > 0; }
 311 
 312   // Determines if a heap allocation failure will be retried
 313   // (e.g., by deoptimizing and re-executing in the interpreter).
 314   // In this case, the failed allocation must raise
 315   // Universe::out_of_memory_error_retry() and omit side effects
 316   // such as JVMTI events and handling -XX:+HeapDumpOnOutOfMemoryError
 317   // and -XX:OnOutOfMemoryError.
 318   virtual bool in_retryable_allocation() const { return false; }
 319 
 320 #ifdef ASSERT
 321   void set_suspendible_thread() {
 322     _suspendible_thread = true;
 323   }
 324 
 325   void clear_suspendible_thread() {
 326     _suspendible_thread = false;
 327   }
 328 
 329   bool is_suspendible_thread() { return _suspendible_thread; }
 330 #endif
 331 
 332  private:
 333   // Active_handles points to a block of handles
 334   JNIHandleBlock* _active_handles;
 335 
 336   // One-element thread local free list
 337   JNIHandleBlock* _free_handle_block;
 338 
 339   // Point to the last handle mark
 340   HandleMark* _last_handle_mark;
 341 
 342   // Claim value for parallel iteration over threads.
 343   uintx _threads_do_token;
 344 
 345   // Support for GlobalCounter
 346  private:
 347   volatile uintx _rcu_counter;
 348  public:
 349   volatile uintx* get_rcu_counter() {
 350     return &_rcu_counter;
 351   }
 352 
 353  public:
 354   void set_last_handle_mark(HandleMark* mark)   { _last_handle_mark = mark; }
 355   HandleMark* last_handle_mark() const          { return _last_handle_mark; }
 356  private:
 357 
 358 #ifdef ASSERT
 359   ICRefillVerifier* _missed_ic_stub_refill_verifier;
 360 
 361  public:
 362   ICRefillVerifier* missed_ic_stub_refill_verifier() {
 363     return _missed_ic_stub_refill_verifier;
 364   }
 365 
 366   void set_missed_ic_stub_refill_verifier(ICRefillVerifier* verifier) {
 367     _missed_ic_stub_refill_verifier = verifier;
 368   }
 369 #endif // ASSERT
 370 
 371  private:
 372 
 373   // Debug support for checking if code allows safepoints or not.
 374   // Safepoints in the VM can happen because of allocation, invoking a VM operation, or blocking on
 375   // mutex, or blocking on an object synchronizer (Java locking).
 376   // If _no_safepoint_count is non-zero, then an assertion failure will happen in any of
 377   // the above cases.
 378   //
 379   // The class NoSafepointVerifier is used to set this counter.
 380   //
 381   NOT_PRODUCT(int _no_safepoint_count;)         // If 0, thread allow a safepoint to happen
 382 
 383  private:
 384   // Used by SkipGCALot class.
 385   NOT_PRODUCT(bool _skip_gcalot;)               // Should we elide gc-a-lot?
 386 
 387   friend class GCLocker;
 388   friend class NoSafepointVerifier;
 389   friend class PauseNoSafepointVerifier;
 390 
 391   volatile void* _polling_page;                 // Thread local polling page
 392 
 393   ThreadLocalAllocBuffer _tlab;                 // Thread-local eden
 394   jlong _allocated_bytes;                       // Cumulative number of bytes allocated on
 395                                                 // the Java heap
 396   ThreadHeapSampler _heap_sampler;              // For use when sampling the memory.
 397 
 398   ThreadStatisticalInfo _statistical_info;      // Statistics about the thread
 399 
 400   JFR_ONLY(DEFINE_THREAD_LOCAL_FIELD_JFR;)      // Thread-local data for jfr
 401 
 402   int   _vm_operation_started_count;            // VM_Operation support
 403   int   _vm_operation_completed_count;          // VM_Operation support
 404 
 405   ObjectMonitor* _current_pending_monitor;      // ObjectMonitor this thread
 406                                                 // is waiting to lock
 407   bool _current_pending_monitor_is_from_java;   // locking is from Java code
 408   JvmtiRawMonitor* _current_pending_raw_monitor; // JvmtiRawMonitor this thread
 409                                                  // is waiting to lock
 410 
 411 
 412   // ObjectMonitor on which this thread called Object.wait()
 413   ObjectMonitor* _current_waiting_monitor;
 414 
 415   // Per-thread ObjectMonitor lists:
 416  public:
 417   ObjectMonitor* om_free_list;                  // SLL of free ObjectMonitors
 418   int om_free_count;                            // # on om_free_list
 419   int om_free_provision;                        // # to try to allocate next
 420   ObjectMonitor* om_in_use_list;                // SLL of in-use ObjectMonitors
 421   int om_in_use_count;                          // # on om_in_use_list
 422 
 423 #ifdef ASSERT
 424  private:
 425   volatile uint64_t _visited_for_critical_count;
 426 
 427  public:
 428   void set_visited_for_critical_count(uint64_t safepoint_id) {
 429     assert(_visited_for_critical_count == 0, "Must be reset before set");
 430     assert((safepoint_id & 0x1) == 1, "Must be odd");
 431     _visited_for_critical_count = safepoint_id;
 432   }
 433   void reset_visited_for_critical_count(uint64_t safepoint_id) {
 434     assert(_visited_for_critical_count == safepoint_id, "Was not visited");
 435     _visited_for_critical_count = 0;
 436   }
 437   bool was_visited_for_critical_count(uint64_t safepoint_id) const {
 438     return _visited_for_critical_count == safepoint_id;
 439   }
 440 #endif
 441 
 442  public:
 443   enum {
 444     is_definitely_current_thread = true
 445   };
 446 
 447   // Constructor
 448   Thread();
 449   virtual ~Thread() = 0;        // Thread is abstract.
 450 
 451   // Manage Thread::current()
 452   void initialize_thread_current();
 453   static void clear_thread_current(); // TLS cleanup needed before threads terminate
 454 
 455  protected:
 456   // To be implemented by children.
 457   virtual void run() = 0;
 458   virtual void pre_run() = 0;
 459   virtual void post_run() = 0;  // Note: Thread must not be deleted prior to calling this!
 460 
 461 #ifdef ASSERT
 462   enum RunState {
 463     PRE_CALL_RUN,
 464     CALL_RUN,
 465     PRE_RUN,
 466     RUN,
 467     POST_RUN
 468     // POST_CALL_RUN - can't define this one as 'this' may be deleted when we want to set it
 469   };
 470   RunState _run_state;  // for lifecycle checks
 471 #endif
 472 
 473 
 474  public:
 475   // invokes <ChildThreadClass>::run(), with common preparations and cleanups.
 476   void call_run();
 477 
 478   // Testers
 479   virtual bool is_VM_thread()       const            { return false; }
 480   virtual bool is_Java_thread()     const            { return false; }
 481   virtual bool is_Compiler_thread() const            { return false; }
 482   virtual bool is_Code_cache_sweeper_thread() const  { return false; }
 483   virtual bool is_hidden_from_external_view() const  { return false; }
 484   virtual bool is_jvmti_agent_thread() const         { return false; }
 485   // True iff the thread can perform GC operations at a safepoint.
 486   // Generally will be true only of VM thread and parallel GC WorkGang
 487   // threads.
 488   virtual bool is_GC_task_thread() const             { return false; }
 489   virtual bool is_Watcher_thread() const             { return false; }
 490   virtual bool is_ConcurrentGC_thread() const        { return false; }
 491   virtual bool is_Named_thread() const               { return false; }
 492   virtual bool is_Worker_thread() const              { return false; }
 493 
 494   // Can this thread make Java upcalls
 495   virtual bool can_call_java() const                 { return false; }
 496 
 497   // Is this a JavaThread that is on the VM's current ThreadsList?
 498   // If so it must participate in the safepoint protocol.
 499   virtual bool is_active_Java_thread() const         { return false; }
 500 
 501   // Casts
 502   virtual WorkerThread* as_Worker_thread() const     { return NULL; }
 503 
 504   virtual char* name() const { return (char*)"Unknown thread"; }
 505 
 506   // Returns the current thread (ASSERTS if NULL)
 507   static inline Thread* current();
 508   // Returns the current thread, or NULL if not attached
 509   static inline Thread* current_or_null();
 510   // Returns the current thread, or NULL if not attached, and is
 511   // safe for use from signal-handlers
 512   static inline Thread* current_or_null_safe();
 513 
 514   // Common thread operations
 515 #ifdef ASSERT
 516   static void check_for_dangling_thread_pointer(Thread *thread);
 517 #endif
 518   static void set_priority(Thread* thread, ThreadPriority priority);
 519   static ThreadPriority get_priority(const Thread* const thread);
 520   static void start(Thread* thread);
 521 
 522   void set_native_thread_name(const char *name) {
 523     assert(Thread::current() == this, "set_native_thread_name can only be called on the current thread");
 524     os::set_native_thread_name(name);
 525   }
 526 
 527   ObjectMonitor** om_in_use_list_addr()          { return (ObjectMonitor **)&om_in_use_list; }
 528   Monitor* SR_lock() const                       { return _SR_lock; }
 529 
 530   bool has_async_exception() const { return (_suspend_flags & _has_async_exception) != 0; }
 531 
 532   inline void set_suspend_flag(SuspendFlags f);
 533   inline void clear_suspend_flag(SuspendFlags f);
 534 
 535   inline void set_has_async_exception();
 536   inline void clear_has_async_exception();
 537 
 538   bool do_critical_native_unlock() const { return (_suspend_flags & _critical_native_unlock) != 0; }
 539 
 540   inline void set_critical_native_unlock();
 541   inline void clear_critical_native_unlock();
 542 
 543   inline void set_trace_flag();
 544   inline void clear_trace_flag();
 545 
 546   // Support for Unhandled Oop detection
 547   // Add the field for both, fastdebug and debug, builds to keep
 548   // Thread's fields layout the same.
 549   // Note: CHECK_UNHANDLED_OOPS is defined only for fastdebug build.
 550 #ifdef CHECK_UNHANDLED_OOPS
 551  private:
 552   UnhandledOops* _unhandled_oops;
 553 #elif defined(ASSERT)
 554  private:
 555   void* _unhandled_oops;
 556 #endif
 557 #ifdef CHECK_UNHANDLED_OOPS
 558  public:
 559   UnhandledOops* unhandled_oops() { return _unhandled_oops; }
 560   // Mark oop safe for gc.  It may be stack allocated but won't move.
 561   void allow_unhandled_oop(oop *op) {
 562     if (CheckUnhandledOops) unhandled_oops()->allow_unhandled_oop(op);
 563   }
 564   // Clear oops at safepoint so crashes point to unhandled oop violator
 565   void clear_unhandled_oops() {
 566     if (CheckUnhandledOops) unhandled_oops()->clear_unhandled_oops();
 567   }
 568 #endif // CHECK_UNHANDLED_OOPS
 569 
 570  public:
 571 #ifndef PRODUCT
 572   bool skip_gcalot()           { return _skip_gcalot; }
 573   void set_skip_gcalot(bool v) { _skip_gcalot = v;    }
 574 #endif
 575 
 576   // Installs a pending exception to be inserted later
 577   static void send_async_exception(oop thread_oop, oop java_throwable);
 578 
 579   // Resource area
 580   ResourceArea* resource_area() const            { return _resource_area; }
 581   void set_resource_area(ResourceArea* area)     { _resource_area = area; }
 582 
 583   OSThread* osthread() const                     { return _osthread;   }
 584   void set_osthread(OSThread* thread)            { _osthread = thread; }
 585 
 586   // JNI handle support
 587   JNIHandleBlock* active_handles() const         { return _active_handles; }
 588   void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
 589   JNIHandleBlock* free_handle_block() const      { return _free_handle_block; }
 590   void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
 591 
 592   // Internal handle support
 593   HandleArea* handle_area() const                { return _handle_area; }
 594   void set_handle_area(HandleArea* area)         { _handle_area = area; }
 595 
 596   GrowableArray<Metadata*>* metadata_handles() const          { return _metadata_handles; }
 597   void set_metadata_handles(GrowableArray<Metadata*>* handles){ _metadata_handles = handles; }
 598 
 599   // Thread-Local Allocation Buffer (TLAB) support
 600   ThreadLocalAllocBuffer& tlab()                 { return _tlab; }
 601   void initialize_tlab() {
 602     if (UseTLAB) {
 603       tlab().initialize();
 604     }
 605   }
 606 
 607   jlong allocated_bytes()               { return _allocated_bytes; }
 608   void set_allocated_bytes(jlong value) { _allocated_bytes = value; }
 609   void incr_allocated_bytes(jlong size) { _allocated_bytes += size; }
 610   inline jlong cooked_allocated_bytes();
 611 
 612   ThreadHeapSampler& heap_sampler()     { return _heap_sampler; }
 613 
 614   ThreadStatisticalInfo& statistical_info() { return _statistical_info; }
 615 
 616   JFR_ONLY(DEFINE_THREAD_LOCAL_ACCESSOR_JFR;)
 617 
 618   bool is_trace_suspend()               { return (_suspend_flags & _trace_flag) != 0; }
 619 
 620   // VM operation support
 621   int vm_operation_ticket()                      { return ++_vm_operation_started_count; }
 622   int vm_operation_completed_count()             { return _vm_operation_completed_count; }
 623   void increment_vm_operation_completed_count()  { _vm_operation_completed_count++; }
 624 
 625   // For tracking the heavyweight monitor the thread is pending on.
 626   ObjectMonitor* current_pending_monitor() {
 627     return _current_pending_monitor;
 628   }
 629   void set_current_pending_monitor(ObjectMonitor* monitor) {
 630     _current_pending_monitor = monitor;
 631   }
 632   void set_current_pending_monitor_is_from_java(bool from_java) {
 633     _current_pending_monitor_is_from_java = from_java;
 634   }
 635   bool current_pending_monitor_is_from_java() {
 636     return _current_pending_monitor_is_from_java;
 637   }
 638 
 639   // For tracking the ObjectMonitor on which this thread called Object.wait()
 640   ObjectMonitor* current_waiting_monitor() {
 641     return _current_waiting_monitor;
 642   }
 643   void set_current_waiting_monitor(ObjectMonitor* monitor) {
 644     _current_waiting_monitor = monitor;
 645   }
 646 
 647   // For tracking the Jvmti raw monitor the thread is pending on.
 648   JvmtiRawMonitor* current_pending_raw_monitor() {
 649     return _current_pending_raw_monitor;
 650   }
 651   void set_current_pending_raw_monitor(JvmtiRawMonitor* monitor) {
 652     _current_pending_raw_monitor = monitor;
 653   }
 654 
 655   // GC support
 656   // Apply "f->do_oop" to all root oops in "this".
 657   //   Used by JavaThread::oops_do.
 658   // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames
 659   virtual void oops_do(OopClosure* f, CodeBlobClosure* cf);
 660 
 661   // Handles the parallel case for claim_threads_do.
 662  private:
 663   bool claim_par_threads_do(uintx claim_token);
 664  public:
 665   // Requires that "claim_token" is that of the current iteration.
 666   // If "is_par" is false, sets the token of "this" to
 667   // "claim_token", and returns "true".  If "is_par" is true,
 668   // uses an atomic instruction to set the current thread's token to
 669   // "claim_token", if it is not already.  Returns "true" iff the
 670   // calling thread does the update, this indicates that the calling thread
 671   // has claimed the thread in the current iteration.
 672   bool claim_threads_do(bool is_par, uintx claim_token) {
 673     if (!is_par) {
 674       _threads_do_token = claim_token;
 675       return true;
 676     } else {
 677       return claim_par_threads_do(claim_token);
 678     }
 679   }
 680 
 681   uintx threads_do_token() const { return _threads_do_token; }
 682 
 683   // jvmtiRedefineClasses support
 684   void metadata_handles_do(void f(Metadata*));
 685 
 686   // Used by fast lock support
 687   virtual bool is_lock_owned(address adr) const;
 688 
 689   // Check if address is in the stack of the thread (not just for locks).
 690   // Warning: the method can only be used on the running thread
 691   bool is_in_stack(address adr) const;
 692   // Check if address is in the usable part of the stack (excludes protected
 693   // guard pages)
 694   bool is_in_usable_stack(address adr) const;
 695 
 696   // Sets this thread as starting thread. Returns failure if thread
 697   // creation fails due to lack of memory, too many threads etc.
 698   bool set_as_starting_thread();
 699 
 700 protected:
 701   // OS data associated with the thread
 702   OSThread* _osthread;  // Platform-specific thread information
 703 
 704   // Thread local resource area for temporary allocation within the VM
 705   ResourceArea* _resource_area;
 706 
 707   DEBUG_ONLY(ResourceMark* _current_resource_mark;)
 708 
 709   // Thread local handle area for allocation of handles within the VM
 710   HandleArea* _handle_area;
 711   GrowableArray<Metadata*>* _metadata_handles;
 712 
 713   // Support for stack overflow handling, get_thread, etc.
 714   address          _stack_base;
 715   size_t           _stack_size;
 716   int              _lgrp_id;
 717 
 718   volatile void** polling_page_addr() { return &_polling_page; }
 719 
 720  public:
 721   // Stack overflow support
 722   address stack_base() const           { assert(_stack_base != NULL,"Sanity check"); return _stack_base; }
 723   void    set_stack_base(address base) { _stack_base = base; }
 724   size_t  stack_size() const           { return _stack_size; }
 725   void    set_stack_size(size_t size)  { _stack_size = size; }
 726   address stack_end()  const           { return stack_base() - stack_size(); }
 727   void    record_stack_base_and_size();
 728   void    register_thread_stack_with_NMT() NOT_NMT_RETURN;
 729 
 730   bool    on_local_stack(address adr) const {
 731     // QQQ this has knowledge of direction, ought to be a stack method
 732     return (_stack_base > adr && adr >= stack_end());
 733   }
 734 
 735   int     lgrp_id() const        { return _lgrp_id; }
 736   void    set_lgrp_id(int value) { _lgrp_id = value; }
 737 
 738   // Printing
 739   void print_on(outputStream* st, bool print_extended_info) const;
 740   virtual void print_on(outputStream* st) const { print_on(st, false); }
 741   void print() const;
 742   virtual void print_on_error(outputStream* st, char* buf, int buflen) const;
 743   void print_value_on(outputStream* st) const;
 744 
 745   // Debug-only code
 746 #ifdef ASSERT
 747  private:
 748   // Deadlock detection support for Mutex locks. List of locks own by thread.
 749   Mutex* _owned_locks;
 750   // Mutex::set_owner_implementation is the only place where _owned_locks is modified,
 751   // thus the friendship
 752   friend class Mutex;
 753   friend class Monitor;
 754 
 755  public:
 756   void print_owned_locks_on(outputStream* st) const;
 757   void print_owned_locks() const                 { print_owned_locks_on(tty);    }
 758   Mutex* owned_locks() const                     { return _owned_locks;          }
 759   bool owns_locks() const                        { return owned_locks() != NULL; }
 760 
 761   // Deadlock detection
 762   ResourceMark* current_resource_mark()          { return _current_resource_mark; }
 763   void set_current_resource_mark(ResourceMark* rm) { _current_resource_mark = rm; }
 764 #endif // ASSERT
 765 
 766   // These functions check conditions on a JavaThread before possibly going to a safepoint,
 767   // including NoSafepointVerifier.
 768   void check_for_valid_safepoint_state() NOT_DEBUG_RETURN;
 769   void check_possible_safepoint() NOT_DEBUG_RETURN;
 770 
 771  private:
 772   volatile int _jvmti_env_iteration_count;
 773 
 774  public:
 775   void entering_jvmti_env_iteration()            { ++_jvmti_env_iteration_count; }
 776   void leaving_jvmti_env_iteration()             { --_jvmti_env_iteration_count; }
 777   bool is_inside_jvmti_env_iteration()           { return _jvmti_env_iteration_count > 0; }
 778 
 779   // Code generation
 780   static ByteSize exception_file_offset()        { return byte_offset_of(Thread, _exception_file); }
 781   static ByteSize exception_line_offset()        { return byte_offset_of(Thread, _exception_line); }
 782   static ByteSize active_handles_offset()        { return byte_offset_of(Thread, _active_handles); }
 783 
 784   static ByteSize stack_base_offset()            { return byte_offset_of(Thread, _stack_base); }
 785   static ByteSize stack_size_offset()            { return byte_offset_of(Thread, _stack_size); }
 786 
 787   static ByteSize polling_page_offset()          { return byte_offset_of(Thread, _polling_page); }
 788 
 789   static ByteSize tlab_start_offset()            { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::start_offset(); }
 790   static ByteSize tlab_end_offset()              { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::end_offset(); }
 791   static ByteSize tlab_top_offset()              { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::top_offset(); }
 792   static ByteSize tlab_pf_top_offset()           { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::pf_top_offset(); }
 793 
 794   static ByteSize allocated_bytes_offset()       { return byte_offset_of(Thread, _allocated_bytes); }
 795 
 796   JFR_ONLY(DEFINE_THREAD_LOCAL_OFFSET_JFR;)
 797 
 798  public:
 799   volatile intptr_t _Stalled;
 800   volatile int _TypeTag;
 801   ParkEvent * _ParkEvent;                     // for Object monitors and JVMTI raw monitors
 802   ParkEvent * _MuxEvent;                      // for low-level muxAcquire-muxRelease
 803   int NativeSyncRecursion;                    // diagnostic
 804 
 805   volatile int _OnTrap;                       // Resume-at IP delta
 806   jint _hashStateW;                           // Marsaglia Shift-XOR thread-local RNG
 807   jint _hashStateX;                           // thread-specific hashCode generator state
 808   jint _hashStateY;
 809   jint _hashStateZ;
 810 
 811   // Low-level leaf-lock primitives used to implement synchronization
 812   // and native monitor-mutex infrastructure.
 813   // Not for general synchronization use.
 814   static void SpinAcquire(volatile int * Lock, const char * Name);
 815   static void SpinRelease(volatile int * Lock);
 816   static void muxAcquire(volatile intptr_t * Lock, const char * Name);
 817   static void muxRelease(volatile intptr_t * Lock);
 818 };
 819 
 820 // Inline implementation of Thread::current()
 821 inline Thread* Thread::current() {
 822   Thread* current = current_or_null();
 823   assert(current != NULL, "Thread::current() called on detached thread");
 824   return current;
 825 }
 826 
 827 inline Thread* Thread::current_or_null() {
 828 #ifndef USE_LIBRARY_BASED_TLS_ONLY
 829   return _thr_current;
 830 #else
 831   if (ThreadLocalStorage::is_initialized()) {
 832     return ThreadLocalStorage::thread();
 833   }
 834   return NULL;
 835 #endif
 836 }
 837 
 838 inline Thread* Thread::current_or_null_safe() {
 839   if (ThreadLocalStorage::is_initialized()) {
 840     return ThreadLocalStorage::thread();
 841   }
 842   return NULL;
 843 }
 844 
 845 class NonJavaThread: public Thread {
 846   friend class VMStructs;
 847 
 848   NonJavaThread* volatile _next;
 849 
 850   class List;
 851   static List _the_list;
 852 
 853   void add_to_the_list();
 854   void remove_from_the_list();
 855 
 856  protected:
 857   virtual void pre_run();
 858   virtual void post_run();
 859 
 860  public:
 861   NonJavaThread();
 862   ~NonJavaThread();
 863 
 864   class Iterator;
 865 };
 866 
 867 // Provides iteration over the list of NonJavaThreads.
 868 // List addition occurs in pre_run(), and removal occurs in post_run(),
 869 // so that only live fully-initialized threads can be found in the list.
 870 // Threads created after an iterator is constructed will not be visited
 871 // by the iterator. The scope of an iterator is a critical section; there
 872 // must be no safepoint checks in that scope.
 873 class NonJavaThread::Iterator : public StackObj {
 874   uint _protect_enter;
 875   NonJavaThread* _current;
 876 
 877   NONCOPYABLE(Iterator);


 878 
 879 public:
 880   Iterator();
 881   ~Iterator();
 882 
 883   bool end() const { return _current == NULL; }
 884   NonJavaThread* current() const { return _current; }
 885   void step();
 886 };
 887 
 888 // Name support for threads.  non-JavaThread subclasses with multiple
 889 // uniquely named instances should derive from this.
 890 class NamedThread: public NonJavaThread {
 891   friend class VMStructs;
 892   enum {
 893     max_name_len = 64
 894   };
 895  private:
 896   char* _name;
 897   // log JavaThread being processed by oops_do
 898   JavaThread* _processed_thread;
 899   uint _gc_id; // The current GC id when a thread takes part in GC
 900 
 901  public:
 902   NamedThread();
 903   ~NamedThread();
 904   // May only be called once per thread.
 905   void set_name(const char* format, ...)  ATTRIBUTE_PRINTF(2, 3);
 906   virtual bool is_Named_thread() const { return true; }
 907   virtual char* name() const { return _name == NULL ? (char*)"Unknown Thread" : _name; }
 908   JavaThread *processed_thread() { return _processed_thread; }
 909   void set_processed_thread(JavaThread *thread) { _processed_thread = thread; }
 910   virtual void print_on(outputStream* st) const;
 911 
 912   void set_gc_id(uint gc_id) { _gc_id = gc_id; }
 913   uint gc_id() { return _gc_id; }
 914 };
 915 
 916 // Worker threads are named and have an id of an assigned work.
 917 class WorkerThread: public NamedThread {
 918  private:
 919   uint _id;
 920  public:
 921   WorkerThread() : _id(0)               { }
 922   virtual bool is_Worker_thread() const { return true; }
 923 
 924   virtual WorkerThread* as_Worker_thread() const {
 925     assert(is_Worker_thread(), "Dubious cast to WorkerThread*?");
 926     return (WorkerThread*) this;
 927   }
 928 
 929   void set_id(uint work_id)             { _id = work_id; }
 930   uint id() const                       { return _id; }
 931 };
 932 
 933 // A single WatcherThread is used for simulating timer interrupts.
 934 class WatcherThread: public NonJavaThread {
 935   friend class VMStructs;
 936  protected:
 937   virtual void run();
 938 
 939  private:
 940   static WatcherThread* _watcher_thread;
 941 
 942   static bool _startable;
 943   // volatile due to at least one lock-free read
 944   volatile static bool _should_terminate;
 945  public:
 946   enum SomeConstants {
 947     delay_interval = 10                          // interrupt delay in milliseconds
 948   };
 949 
 950   // Constructor
 951   WatcherThread();
 952 
 953   // No destruction allowed
 954   ~WatcherThread() {
 955     guarantee(false, "WatcherThread deletion must fix the race with VM termination");
 956   }
 957 
 958   // Tester
 959   bool is_Watcher_thread() const                 { return true; }
 960 
 961   // Printing
 962   char* name() const { return (char*)"VM Periodic Task Thread"; }
 963   void print_on(outputStream* st) const;
 964   void unpark();
 965 
 966   // Returns the single instance of WatcherThread
 967   static WatcherThread* watcher_thread()         { return _watcher_thread; }
 968 
 969   // Create and start the single instance of WatcherThread, or stop it on shutdown
 970   static void start();
 971   static void stop();
 972   // Only allow start once the VM is sufficiently initialized
 973   // Otherwise the first task to enroll will trigger the start
 974   static void make_startable();
 975  private:
 976   int sleep() const;
 977 };
 978 
 979 
 980 class CompilerThread;
 981 
 982 typedef void (*ThreadFunction)(JavaThread*, TRAPS);
 983 
 984 class JavaThread: public Thread {
 985   friend class VMStructs;
 986   friend class JVMCIVMStructs;
 987   friend class WhiteBox;
 988  private:
 989   bool           _on_thread_list;                // Is set when this JavaThread is added to the Threads list
 990   oop            _threadObj;                     // The Java level thread object
 991 
 992 #ifdef ASSERT
 993  private:
 994   int _java_call_counter;
 995 
 996  public:
 997   int  java_call_counter()                       { return _java_call_counter; }
 998   void inc_java_call_counter()                   { _java_call_counter++; }
 999   void dec_java_call_counter() {
1000     assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
1001     _java_call_counter--;
1002   }
1003  private:  // restore original namespace restriction
1004 #endif  // ifdef ASSERT
1005 
1006 #ifndef PRODUCT
1007  public:
1008   enum {
1009     jump_ring_buffer_size = 16
1010   };
1011  private:  // restore original namespace restriction
1012 #endif
1013 
1014   JavaFrameAnchor _anchor;                       // Encapsulation of current java frame and it state
1015 
1016   ThreadFunction _entry_point;
1017 
1018   JNIEnv        _jni_environment;
1019 
1020   // Deopt support
1021   DeoptResourceMark*  _deopt_mark;               // Holds special ResourceMark for deoptimization
1022 
1023   CompiledMethod*       _deopt_nmethod;         // CompiledMethod that is currently being deoptimized
1024   vframeArray*  _vframe_array_head;              // Holds the heap of the active vframeArrays
1025   vframeArray*  _vframe_array_last;              // Holds last vFrameArray we popped
1026   // Because deoptimization is lazy we must save jvmti requests to set locals
1027   // in compiled frames until we deoptimize and we have an interpreter frame.
1028   // This holds the pointer to array (yeah like there might be more than one) of
1029   // description of compiled vframes that have locals that need to be updated.
1030   GrowableArray<jvmtiDeferredLocalVariableSet*>* _deferred_locals_updates;
1031 
1032   // Handshake value for fixing 6243940. We need a place for the i2c
1033   // adapter to store the callee Method*. This value is NEVER live
1034   // across a gc point so it does NOT have to be gc'd
1035   // The handshake is open ended since we can't be certain that it will
1036   // be NULLed. This is because we rarely ever see the race and end up
1037   // in handle_wrong_method which is the backend of the handshake. See
1038   // code in i2c adapters and handle_wrong_method.
1039 
1040   Method*       _callee_target;
1041 
1042   // Used to pass back results to the interpreter or generated code running Java code.
1043   oop           _vm_result;    // oop result is GC-preserved
1044   Metadata*     _vm_result_2;  // non-oop result
1045 
1046   // See ReduceInitialCardMarks: this holds the precise space interval of
1047   // the most recent slow path allocation for which compiled code has
1048   // elided card-marks for performance along the fast-path.
1049   MemRegion     _deferred_card_mark;
1050 
1051   MonitorChunk* _monitor_chunks;                 // Contains the off stack monitors
1052                                                  // allocated during deoptimization
1053                                                  // and by JNI_MonitorEnter/Exit
1054 
1055   // Async. requests support
1056   enum AsyncRequests {
1057     _no_async_condition = 0,
1058     _async_exception,
1059     _async_unsafe_access_error
1060   };
1061   AsyncRequests _special_runtime_exit_condition; // Enum indicating pending async. request
1062   oop           _pending_async_exception;
1063 
1064   // Safepoint support
1065  public:                                         // Expose _thread_state for SafeFetchInt()
1066   volatile JavaThreadState _thread_state;
1067  private:
1068   ThreadSafepointState* _safepoint_state;        // Holds information about a thread during a safepoint
1069   address               _saved_exception_pc;     // Saved pc of instruction where last implicit exception happened
1070 
1071   // JavaThread termination support
1072   enum TerminatedTypes {
1073     _not_terminated = 0xDEAD - 2,
1074     _thread_exiting,                             // JavaThread::exit() has been called for this thread
1075     _thread_terminated,                          // JavaThread is removed from thread list
1076     _vm_exited                                   // JavaThread is still executing native code, but VM is terminated
1077                                                  // only VM_Exit can set _vm_exited
1078   };
1079 
1080   // In general a JavaThread's _terminated field transitions as follows:
1081   //
1082   //   _not_terminated => _thread_exiting => _thread_terminated
1083   //
1084   // _vm_exited is a special value to cover the case of a JavaThread
1085   // executing native code after the VM itself is terminated.
1086   volatile TerminatedTypes _terminated;
1087   // suspend/resume support
1088   volatile bool         _suspend_equivalent;     // Suspend equivalent condition
1089   jint                  _in_deopt_handler;       // count of deoptimization
1090                                                  // handlers thread is in
1091   volatile bool         _doing_unsafe_access;    // Thread may fault due to unsafe access
1092   bool                  _do_not_unlock_if_synchronized;  // Do not unlock the receiver of a synchronized method (since it was
1093                                                          // never locked) when throwing an exception. Used by interpreter only.
1094 
1095   // JNI attach states:
1096   enum JNIAttachStates {
1097     _not_attaching_via_jni = 1,  // thread is not attaching via JNI
1098     _attaching_via_jni,          // thread is attaching via JNI
1099     _attached_via_jni            // thread has attached via JNI
1100   };
1101 
1102   // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
1103   // A native thread that is attaching via JNI starts with a value
1104   // of _attaching_via_jni and transitions to _attached_via_jni.
1105   volatile JNIAttachStates _jni_attach_state;
1106 
1107  public:
1108   // State of the stack guard pages for this thread.
1109   enum StackGuardState {
1110     stack_guard_unused,         // not needed
1111     stack_guard_reserved_disabled,
1112     stack_guard_yellow_reserved_disabled,// disabled (temporarily) after stack overflow
1113     stack_guard_enabled         // enabled
1114   };
1115 
1116  private:
1117 
1118 #if INCLUDE_JVMCI
1119   // The _pending_* fields below are used to communicate extra information
1120   // from an uncommon trap in JVMCI compiled code to the uncommon trap handler.
1121 
1122   // Communicates the DeoptReason and DeoptAction of the uncommon trap
1123   int       _pending_deoptimization;
1124 
1125   // Specifies whether the uncommon trap is to bci 0 of a synchronized method
1126   // before the monitor has been acquired.
1127   bool      _pending_monitorenter;
1128 
1129   // Specifies if the DeoptReason for the last uncommon trap was Reason_transfer_to_interpreter
1130   bool      _pending_transfer_to_interpreter;
1131 
1132   // True if in a runtime call from compiled code that will deoptimize
1133   // and re-execute a failed heap allocation in the interpreter.
1134   bool      _in_retryable_allocation;
1135 
1136   // An id of a speculation that JVMCI compiled code can use to further describe and
1137   // uniquely identify the  speculative optimization guarded by the uncommon trap
1138   jlong     _pending_failed_speculation;
1139 
1140   // These fields are mutually exclusive in terms of live ranges.
1141   union {
1142     // Communicates the pc at which the most recent implicit exception occurred
1143     // from the signal handler to a deoptimization stub.
1144     address   _implicit_exception_pc;
1145 
1146     // Communicates an alternative call target to an i2c stub from a JavaCall .
1147     address   _alternate_call_target;
1148   } _jvmci;
1149 
1150   // Support for high precision, thread sensitive counters in JVMCI compiled code.
1151   jlong*    _jvmci_counters;
1152 
1153  public:
1154   static jlong* _jvmci_old_thread_counters;
1155   static void collect_counters(jlong* array, int length);
1156   void resize_counters(int current_size, int new_size);
1157   static void resize_all_jvmci_counters(int new_size);
1158 
1159  private:
1160 #endif // INCLUDE_JVMCI
1161 
1162   StackGuardState  _stack_guard_state;
1163 
1164   // Precompute the limit of the stack as used in stack overflow checks.
1165   // We load it from here to simplify the stack overflow check in assembly.
1166   address          _stack_overflow_limit;
1167   address          _reserved_stack_activation;
1168 
1169   // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
1170   // used to temp. parsing values into and out of the runtime system during exception handling for compiled
1171   // code)
1172   volatile oop     _exception_oop;               // Exception thrown in compiled code
1173   volatile address _exception_pc;                // PC where exception happened
1174   volatile address _exception_handler_pc;        // PC for handler of exception
1175   volatile int     _is_method_handle_return;     // true (== 1) if the current exception PC is a MethodHandle call site.
1176 
1177  private:
1178   // support for JNI critical regions
1179   jint    _jni_active_critical;                  // count of entries into JNI critical region
1180 
1181   // Checked JNI: function name requires exception check
1182   char* _pending_jni_exception_check_fn;
1183 
1184   // For deadlock detection.
1185   int _depth_first_number;
1186 
1187   // JVMTI PopFrame support
1188   // This is set to popframe_pending to signal that top Java frame should be popped immediately
1189   int _popframe_condition;
1190 
1191   // If reallocation of scalar replaced objects fails, we throw OOM
1192   // and during exception propagation, pop the top
1193   // _frames_to_pop_failed_realloc frames, the ones that reference
1194   // failed reallocations.
1195   int _frames_to_pop_failed_realloc;
1196 
1197   friend class VMThread;
1198   friend class ThreadWaitTransition;
1199   friend class VM_Exit;
1200 
1201   void initialize();                             // Initialized the instance variables
1202 
1203  public:
1204   // Constructor
1205   JavaThread(bool is_attaching_via_jni = false); // for main thread and JNI attached threads
1206   JavaThread(ThreadFunction entry_point, size_t stack_size = 0);
1207   ~JavaThread();
1208 
1209 #ifdef ASSERT
1210   // verify this JavaThread hasn't be published in the Threads::list yet
1211   void verify_not_published();
1212 #endif // ASSERT
1213 
1214   //JNI functiontable getter/setter for JVMTI jni function table interception API.
1215   void set_jni_functions(struct JNINativeInterface_* functionTable) {
1216     _jni_environment.functions = functionTable;
1217   }
1218   struct JNINativeInterface_* get_jni_functions() {
1219     return (struct JNINativeInterface_ *)_jni_environment.functions;
1220   }
1221 
1222   // This function is called at thread creation to allow
1223   // platform specific thread variables to be initialized.
1224   void cache_global_variables();
1225 
1226   // Executes Shutdown.shutdown()
1227   void invoke_shutdown_hooks();
1228 
1229   // Cleanup on thread exit
1230   enum ExitType {
1231     normal_exit,
1232     jni_detach
1233   };
1234   void exit(bool destroy_vm, ExitType exit_type = normal_exit);
1235 
1236   void cleanup_failed_attach_current_thread(bool is_daemon);
1237 
1238   // Testers
1239   virtual bool is_Java_thread() const            { return true;  }
1240   virtual bool can_call_java() const             { return true; }
1241 
1242   virtual bool is_active_Java_thread() const {
1243     return on_thread_list() && !is_terminated();
1244   }
1245 
1246   // Thread oop. threadObj() can be NULL for initial JavaThread
1247   // (or for threads attached via JNI)
1248   oop threadObj() const                          { return _threadObj; }
1249   void set_threadObj(oop p)                      { _threadObj = p; }
1250 
1251   // Prepare thread and add to priority queue.  If a priority is
1252   // not specified, use the priority of the thread object. Threads_lock
1253   // must be held while this function is called.
1254   void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
1255 
1256   void set_saved_exception_pc(address pc)        { _saved_exception_pc = pc; }
1257   address saved_exception_pc()                   { return _saved_exception_pc; }
1258 
1259 
1260   ThreadFunction entry_point() const             { return _entry_point; }
1261 
1262   // Allocates a new Java level thread object for this thread. thread_name may be NULL.
1263   void allocate_threadObj(Handle thread_group, const char* thread_name, bool daemon, TRAPS);
1264 
1265   // Last frame anchor routines
1266 
1267   JavaFrameAnchor* frame_anchor(void)            { return &_anchor; }
1268 
1269   // last_Java_sp
1270   bool has_last_Java_frame() const               { return _anchor.has_last_Java_frame(); }
1271   intptr_t* last_Java_sp() const                 { return _anchor.last_Java_sp(); }
1272 
1273   // last_Java_pc
1274 
1275   address last_Java_pc(void)                     { return _anchor.last_Java_pc(); }
1276 
1277   // Safepoint support
1278   inline JavaThreadState thread_state() const;
1279   inline void set_thread_state(JavaThreadState s);
1280   inline void set_thread_state_fence(JavaThreadState s);  // fence after setting thread state
1281   inline ThreadSafepointState* safepoint_state() const;
1282   inline void set_safepoint_state(ThreadSafepointState* state);
1283   inline bool is_at_poll_safepoint();
1284 
1285   // JavaThread termination and lifecycle support:
1286   void smr_delete();
1287   bool on_thread_list() const { return _on_thread_list; }
1288   void set_on_thread_list() { _on_thread_list = true; }
1289 
1290   // thread has called JavaThread::exit() or is terminated
1291   bool is_exiting() const;
1292   // thread is terminated (no longer on the threads list); we compare
1293   // against the two non-terminated values so that a freed JavaThread
1294   // will also be considered terminated.
1295   bool check_is_terminated(TerminatedTypes l_terminated) const {
1296     return l_terminated != _not_terminated && l_terminated != _thread_exiting;
1297   }
1298   bool is_terminated() const;
1299   void set_terminated(TerminatedTypes t);
1300   // special for Threads::remove() which is static:
1301   void set_terminated_value();
1302   void block_if_vm_exited();
1303 
1304   bool doing_unsafe_access()                     { return _doing_unsafe_access; }
1305   void set_doing_unsafe_access(bool val)         { _doing_unsafe_access = val; }
1306 
1307   bool do_not_unlock_if_synchronized()             { return _do_not_unlock_if_synchronized; }
1308   void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
1309 
1310   inline void set_polling_page_release(void* poll_value);
1311   inline void set_polling_page(void* poll_value);
1312   inline volatile void* get_polling_page();
1313 
1314  private:
1315   // Support for thread handshake operations
1316   HandshakeState _handshake;
1317  public:
1318   void set_handshake_operation(HandshakeOperation* op) {
1319     _handshake.set_operation(this, op);
1320   }
1321 
1322   bool has_handshake() const {
1323     return _handshake.has_operation();
1324   }
1325 
1326   void handshake_process_by_self() {
1327     _handshake.process_by_self(this);
1328   }
1329 
1330   void handshake_process_by_vmthread() {
1331     _handshake.process_by_vmthread(this);
1332   }
1333 
1334   // Suspend/resume support for JavaThread
1335  private:
1336   inline void set_ext_suspended();
1337   inline void clear_ext_suspended();
1338 
1339  public:
1340   void java_suspend(); // higher-level suspension logic called by the public APIs
1341   void java_resume();  // higher-level resume logic called by the public APIs
1342   int  java_suspend_self(); // low-level self-suspension mechanics
1343 
1344  private:
1345   // mid-level wrapper around java_suspend_self to set up correct state and
1346   // check for a pending safepoint at the end
1347   void java_suspend_self_with_safepoint_check();
1348 
1349  public:
1350   void check_and_wait_while_suspended() {
1351     assert(JavaThread::current() == this, "sanity check");
1352 
1353     bool do_self_suspend;
1354     do {
1355       // were we externally suspended while we were waiting?
1356       do_self_suspend = handle_special_suspend_equivalent_condition();
1357       if (do_self_suspend) {
1358         // don't surprise the thread that suspended us by returning
1359         java_suspend_self();
1360         set_suspend_equivalent();
1361       }
1362     } while (do_self_suspend);
1363   }
1364   static void check_safepoint_and_suspend_for_native_trans(JavaThread *thread);
1365   // Check for async exception in addition to safepoint and suspend request.
1366   static void check_special_condition_for_native_trans(JavaThread *thread);
1367 
1368   // Same as check_special_condition_for_native_trans but finishes the
1369   // transition into thread_in_Java mode so that it can potentially
1370   // block.
1371   static void check_special_condition_for_native_trans_and_transition(JavaThread *thread);
1372 
1373   bool is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits);
1374   bool is_ext_suspend_completed_with_lock(uint32_t *bits) {
1375     MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1376     // Warning: is_ext_suspend_completed() may temporarily drop the
1377     // SR_lock to allow the thread to reach a stable thread state if
1378     // it is currently in a transient thread state.
1379     return is_ext_suspend_completed(false /* !called_by_wait */,
1380                                     SuspendRetryDelay, bits);
1381   }
1382 
1383   // We cannot allow wait_for_ext_suspend_completion() to run forever or
1384   // we could hang. SuspendRetryCount and SuspendRetryDelay are normally
1385   // passed as the count and delay parameters. Experiments with specific
1386   // calls to wait_for_ext_suspend_completion() can be done by passing
1387   // other values in the code. Experiments with all calls can be done
1388   // via the appropriate -XX options.
1389   bool wait_for_ext_suspend_completion(int count, int delay, uint32_t *bits);
1390 
1391   // test for suspend - most (all?) of these should go away
1392   bool is_thread_fully_suspended(bool wait_for_suspend, uint32_t *bits);
1393 
1394   inline void set_external_suspend();
1395   inline void clear_external_suspend();
1396 
1397   bool is_external_suspend() const {
1398     return (_suspend_flags & _external_suspend) != 0;
1399   }
1400   // Whenever a thread transitions from native to vm/java it must suspend
1401   // if external|deopt suspend is present.
1402   bool is_suspend_after_native() const {
1403     return (_suspend_flags & (_external_suspend JFR_ONLY(| _trace_flag))) != 0;
1404   }
1405 
1406   // external suspend request is completed
1407   bool is_ext_suspended() const {
1408     return (_suspend_flags & _ext_suspended) != 0;
1409   }
1410 
1411   bool is_external_suspend_with_lock() const {
1412     MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1413     return is_external_suspend();
1414   }
1415 
1416   // Special method to handle a pending external suspend request
1417   // when a suspend equivalent condition lifts.
1418   bool handle_special_suspend_equivalent_condition() {
1419     assert(is_suspend_equivalent(),
1420            "should only be called in a suspend equivalence condition");
1421     MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1422     bool ret = is_external_suspend();
1423     if (!ret) {
1424       // not about to self-suspend so clear suspend equivalence
1425       clear_suspend_equivalent();
1426     }
1427     // implied else:
1428     // We have a pending external suspend request so we leave the
1429     // suspend_equivalent flag set until java_suspend_self() sets
1430     // the ext_suspended flag and clears the suspend_equivalent
1431     // flag. This insures that wait_for_ext_suspend_completion()
1432     // will return consistent values.
1433     return ret;
1434   }
1435 
1436   // utility methods to see if we are doing some kind of suspension
1437   bool is_being_ext_suspended() const            {
1438     MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1439     return is_ext_suspended() || is_external_suspend();
1440   }
1441 
1442   bool is_suspend_equivalent() const             { return _suspend_equivalent; }
1443 
1444   void set_suspend_equivalent()                  { _suspend_equivalent = true; }
1445   void clear_suspend_equivalent()                { _suspend_equivalent = false; }
1446 
1447   // Thread.stop support
1448   void send_thread_stop(oop throwable);
1449   AsyncRequests clear_special_runtime_exit_condition() {
1450     AsyncRequests x = _special_runtime_exit_condition;
1451     _special_runtime_exit_condition = _no_async_condition;
1452     return x;
1453   }
1454 
1455   // Are any async conditions present?
1456   bool has_async_condition() { return (_special_runtime_exit_condition != _no_async_condition); }
1457 
1458   void check_and_handle_async_exceptions(bool check_unsafe_error = true);
1459 
1460   // these next two are also used for self-suspension and async exception support
1461   void handle_special_runtime_exit_condition(bool check_asyncs = true);
1462 
1463   // Return true if JavaThread has an asynchronous condition or
1464   // if external suspension is requested.
1465   bool has_special_runtime_exit_condition() {
1466     // Because we don't use is_external_suspend_with_lock
1467     // it is possible that we won't see an asynchronous external suspend
1468     // request that has just gotten started, i.e., SR_lock grabbed but
1469     // _external_suspend field change either not made yet or not visible
1470     // yet. However, this is okay because the request is asynchronous and
1471     // we will see the new flag value the next time through. It's also
1472     // possible that the external suspend request is dropped after
1473     // we have checked is_external_suspend(), we will recheck its value
1474     // under SR_lock in java_suspend_self().
1475     return (_special_runtime_exit_condition != _no_async_condition) ||
1476             is_external_suspend() || is_trace_suspend();
1477   }
1478 
1479   void set_pending_unsafe_access_error()          { _special_runtime_exit_condition = _async_unsafe_access_error; }
1480 
1481   inline void set_pending_async_exception(oop e);
1482 
1483   // Fast-locking support
1484   bool is_lock_owned(address adr) const;
1485 
1486   // Accessors for vframe array top
1487   // The linked list of vframe arrays are sorted on sp. This means when we
1488   // unpack the head must contain the vframe array to unpack.
1489   void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
1490   vframeArray* vframe_array_head() const         { return _vframe_array_head;  }
1491 
1492   // Side structure for deferring update of java frame locals until deopt occurs
1493   GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred_locals() const { return _deferred_locals_updates; }
1494   void set_deferred_locals(GrowableArray<jvmtiDeferredLocalVariableSet *>* vf) { _deferred_locals_updates = vf; }
1495 
1496   // These only really exist to make debugging deopt problems simpler
1497 
1498   void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
1499   vframeArray* vframe_array_last() const         { return _vframe_array_last;  }
1500 
1501   // The special resourceMark used during deoptimization
1502 
1503   void set_deopt_mark(DeoptResourceMark* value)  { _deopt_mark = value; }
1504   DeoptResourceMark* deopt_mark(void)            { return _deopt_mark; }
1505 
1506   void set_deopt_compiled_method(CompiledMethod* nm)  { _deopt_nmethod = nm; }
1507   CompiledMethod* deopt_compiled_method()        { return _deopt_nmethod; }
1508 
1509   Method*    callee_target() const               { return _callee_target; }
1510   void set_callee_target  (Method* x)          { _callee_target   = x; }
1511 
1512   // Oop results of vm runtime calls
1513   oop  vm_result() const                         { return _vm_result; }
1514   void set_vm_result  (oop x)                    { _vm_result   = x; }
1515 
1516   Metadata*    vm_result_2() const               { return _vm_result_2; }
1517   void set_vm_result_2  (Metadata* x)          { _vm_result_2   = x; }
1518 
1519   MemRegion deferred_card_mark() const           { return _deferred_card_mark; }
1520   void set_deferred_card_mark(MemRegion mr)      { _deferred_card_mark = mr;   }
1521 
1522 #if INCLUDE_JVMCI
1523   int  pending_deoptimization() const             { return _pending_deoptimization; }
1524   jlong pending_failed_speculation() const        { return _pending_failed_speculation; }
1525   bool has_pending_monitorenter() const           { return _pending_monitorenter; }
1526   void set_pending_monitorenter(bool b)           { _pending_monitorenter = b; }
1527   void set_pending_deoptimization(int reason)     { _pending_deoptimization = reason; }
1528   void set_pending_failed_speculation(jlong failed_speculation) { _pending_failed_speculation = failed_speculation; }
1529   void set_pending_transfer_to_interpreter(bool b) { _pending_transfer_to_interpreter = b; }
1530   void set_jvmci_alternate_call_target(address a) { assert(_jvmci._alternate_call_target == NULL, "must be"); _jvmci._alternate_call_target = a; }
1531   void set_jvmci_implicit_exception_pc(address a) { assert(_jvmci._implicit_exception_pc == NULL, "must be"); _jvmci._implicit_exception_pc = a; }
1532 
1533   virtual bool in_retryable_allocation() const    { return _in_retryable_allocation; }
1534   void set_in_retryable_allocation(bool b)        { _in_retryable_allocation = b; }
1535 #endif // INCLUDE_JVMCI
1536 
1537   // Exception handling for compiled methods
1538   oop      exception_oop() const                 { return _exception_oop; }
1539   address  exception_pc() const                  { return _exception_pc; }
1540   address  exception_handler_pc() const          { return _exception_handler_pc; }
1541   bool     is_method_handle_return() const       { return _is_method_handle_return == 1; }
1542 
1543   void set_exception_oop(oop o)                  { (void)const_cast<oop&>(_exception_oop = o); }
1544   void set_exception_pc(address a)               { _exception_pc = a; }
1545   void set_exception_handler_pc(address a)       { _exception_handler_pc = a; }
1546   void set_is_method_handle_return(bool value)   { _is_method_handle_return = value ? 1 : 0; }
1547 
1548   void clear_exception_oop_and_pc() {
1549     set_exception_oop(NULL);
1550     set_exception_pc(NULL);
1551   }
1552 
1553   // Stack overflow support
1554   //
1555   //  (small addresses)
1556   //
1557   //  --  <-- stack_end()                   ---
1558   //  |                                      |
1559   //  |  red pages                           |
1560   //  |                                      |
1561   //  --  <-- stack_red_zone_base()          |
1562   //  |                                      |
1563   //  |                                     guard
1564   //  |  yellow pages                       zone
1565   //  |                                      |
1566   //  |                                      |
1567   //  --  <-- stack_yellow_zone_base()       |
1568   //  |                                      |
1569   //  |                                      |
1570   //  |  reserved pages                      |
1571   //  |                                      |
1572   //  --  <-- stack_reserved_zone_base()    ---      ---
1573   //                                                 /|\  shadow     <--  stack_overflow_limit() (somewhere in here)
1574   //                                                  |   zone
1575   //                                                 \|/  size
1576   //  some untouched memory                          ---
1577   //
1578   //
1579   //  --
1580   //  |
1581   //  |  shadow zone
1582   //  |
1583   //  --
1584   //  x    frame n
1585   //  --
1586   //  x    frame n-1
1587   //  x
1588   //  --
1589   //  ...
1590   //
1591   //  --
1592   //  x    frame 0
1593   //  --  <-- stack_base()
1594   //
1595   //  (large addresses)
1596   //
1597 
1598  private:
1599   // These values are derived from flags StackRedPages, StackYellowPages,
1600   // StackReservedPages and StackShadowPages. The zone size is determined
1601   // ergonomically if page_size > 4K.
1602   static size_t _stack_red_zone_size;
1603   static size_t _stack_yellow_zone_size;
1604   static size_t _stack_reserved_zone_size;
1605   static size_t _stack_shadow_zone_size;
1606  public:
1607   inline size_t stack_available(address cur_sp);
1608 
1609   static size_t stack_red_zone_size() {
1610     assert(_stack_red_zone_size > 0, "Don't call this before the field is initialized.");
1611     return _stack_red_zone_size;
1612   }
1613   static void set_stack_red_zone_size(size_t s) {
1614     assert(is_aligned(s, os::vm_page_size()),
1615            "We can not protect if the red zone size is not page aligned.");
1616     assert(_stack_red_zone_size == 0, "This should be called only once.");
1617     _stack_red_zone_size = s;
1618   }
1619   address stack_red_zone_base() {
1620     return (address)(stack_end() + stack_red_zone_size());
1621   }
1622   bool in_stack_red_zone(address a) {
1623     return a <= stack_red_zone_base() && a >= stack_end();
1624   }
1625 
1626   static size_t stack_yellow_zone_size() {
1627     assert(_stack_yellow_zone_size > 0, "Don't call this before the field is initialized.");
1628     return _stack_yellow_zone_size;
1629   }
1630   static void set_stack_yellow_zone_size(size_t s) {
1631     assert(is_aligned(s, os::vm_page_size()),
1632            "We can not protect if the yellow zone size is not page aligned.");
1633     assert(_stack_yellow_zone_size == 0, "This should be called only once.");
1634     _stack_yellow_zone_size = s;
1635   }
1636 
1637   static size_t stack_reserved_zone_size() {
1638     // _stack_reserved_zone_size may be 0. This indicates the feature is off.
1639     return _stack_reserved_zone_size;
1640   }
1641   static void set_stack_reserved_zone_size(size_t s) {
1642     assert(is_aligned(s, os::vm_page_size()),
1643            "We can not protect if the reserved zone size is not page aligned.");
1644     assert(_stack_reserved_zone_size == 0, "This should be called only once.");
1645     _stack_reserved_zone_size = s;
1646   }
1647   address stack_reserved_zone_base() {
1648     return (address)(stack_end() +
1649                      (stack_red_zone_size() + stack_yellow_zone_size() + stack_reserved_zone_size()));
1650   }
1651   bool in_stack_reserved_zone(address a) {
1652     return (a <= stack_reserved_zone_base()) &&
1653            (a >= (address)((intptr_t)stack_reserved_zone_base() - stack_reserved_zone_size()));
1654   }
1655 
1656   static size_t stack_yellow_reserved_zone_size() {
1657     return _stack_yellow_zone_size + _stack_reserved_zone_size;
1658   }
1659   bool in_stack_yellow_reserved_zone(address a) {
1660     return (a <= stack_reserved_zone_base()) && (a >= stack_red_zone_base());
1661   }
1662 
1663   // Size of red + yellow + reserved zones.
1664   static size_t stack_guard_zone_size() {
1665     return stack_red_zone_size() + stack_yellow_reserved_zone_size();
1666   }
1667 
1668   static size_t stack_shadow_zone_size() {
1669     assert(_stack_shadow_zone_size > 0, "Don't call this before the field is initialized.");
1670     return _stack_shadow_zone_size;
1671   }
1672   static void set_stack_shadow_zone_size(size_t s) {
1673     // The shadow area is not allocated or protected, so
1674     // it needs not be page aligned.
1675     // But the stack bang currently assumes that it is a
1676     // multiple of page size. This guarantees that the bang
1677     // loop touches all pages in the shadow zone.
1678     // This can be guaranteed differently, as well.  E.g., if
1679     // the page size is a multiple of 4K, banging in 4K steps
1680     // suffices to touch all pages. (Some pages are banged
1681     // several times, though.)
1682     assert(is_aligned(s, os::vm_page_size()),
1683            "Stack bang assumes multiple of page size.");
1684     assert(_stack_shadow_zone_size == 0, "This should be called only once.");
1685     _stack_shadow_zone_size = s;
1686   }
1687 
1688   void create_stack_guard_pages();
1689   void remove_stack_guard_pages();
1690 
1691   void enable_stack_reserved_zone();
1692   void disable_stack_reserved_zone();
1693   void enable_stack_yellow_reserved_zone();
1694   void disable_stack_yellow_reserved_zone();
1695   void enable_stack_red_zone();
1696   void disable_stack_red_zone();
1697 
1698   inline bool stack_guard_zone_unused();
1699   inline bool stack_yellow_reserved_zone_disabled();
1700   inline bool stack_reserved_zone_disabled();
1701   inline bool stack_guards_enabled();
1702 
1703   address reserved_stack_activation() const { return _reserved_stack_activation; }
1704   void set_reserved_stack_activation(address addr) {
1705     assert(_reserved_stack_activation == stack_base()
1706             || _reserved_stack_activation == NULL
1707             || addr == stack_base(), "Must not be set twice");
1708     _reserved_stack_activation = addr;
1709   }
1710 
1711   // Attempt to reguard the stack after a stack overflow may have occurred.
1712   // Returns true if (a) guard pages are not needed on this thread, (b) the
1713   // pages are already guarded, or (c) the pages were successfully reguarded.
1714   // Returns false if there is not enough stack space to reguard the pages, in
1715   // which case the caller should unwind a frame and try again.  The argument
1716   // should be the caller's (approximate) sp.
1717   bool reguard_stack(address cur_sp);
1718   // Similar to above but see if current stackpoint is out of the guard area
1719   // and reguard if possible.
1720   bool reguard_stack(void);
1721 
1722   address stack_overflow_limit() { return _stack_overflow_limit; }
1723   void set_stack_overflow_limit() {
1724     _stack_overflow_limit =
1725       stack_end() + MAX2(JavaThread::stack_guard_zone_size(), JavaThread::stack_shadow_zone_size());
1726   }
1727 
1728   // Misc. accessors/mutators
1729   void set_do_not_unlock(void)                   { _do_not_unlock_if_synchronized = true; }
1730   void clr_do_not_unlock(void)                   { _do_not_unlock_if_synchronized = false; }
1731   bool do_not_unlock(void)                       { return _do_not_unlock_if_synchronized; }
1732 
1733   // For assembly stub generation
1734   static ByteSize threadObj_offset()             { return byte_offset_of(JavaThread, _threadObj); }
1735   static ByteSize jni_environment_offset()       { return byte_offset_of(JavaThread, _jni_environment); }
1736   static ByteSize pending_jni_exception_check_fn_offset() {
1737     return byte_offset_of(JavaThread, _pending_jni_exception_check_fn);
1738   }
1739   static ByteSize last_Java_sp_offset() {
1740     return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
1741   }
1742   static ByteSize last_Java_pc_offset() {
1743     return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
1744   }
1745   static ByteSize frame_anchor_offset() {
1746     return byte_offset_of(JavaThread, _anchor);
1747   }
1748   static ByteSize callee_target_offset()         { return byte_offset_of(JavaThread, _callee_target); }
1749   static ByteSize vm_result_offset()             { return byte_offset_of(JavaThread, _vm_result); }
1750   static ByteSize vm_result_2_offset()           { return byte_offset_of(JavaThread, _vm_result_2); }
1751   static ByteSize thread_state_offset()          { return byte_offset_of(JavaThread, _thread_state); }
1752   static ByteSize saved_exception_pc_offset()    { return byte_offset_of(JavaThread, _saved_exception_pc); }
1753   static ByteSize osthread_offset()              { return byte_offset_of(JavaThread, _osthread); }
1754 #if INCLUDE_JVMCI
1755   static ByteSize pending_deoptimization_offset() { return byte_offset_of(JavaThread, _pending_deoptimization); }
1756   static ByteSize pending_monitorenter_offset()  { return byte_offset_of(JavaThread, _pending_monitorenter); }
1757   static ByteSize pending_failed_speculation_offset() { return byte_offset_of(JavaThread, _pending_failed_speculation); }
1758   static ByteSize jvmci_alternate_call_target_offset() { return byte_offset_of(JavaThread, _jvmci._alternate_call_target); }
1759   static ByteSize jvmci_implicit_exception_pc_offset() { return byte_offset_of(JavaThread, _jvmci._implicit_exception_pc); }
1760   static ByteSize jvmci_counters_offset()        { return byte_offset_of(JavaThread, _jvmci_counters); }
1761 #endif // INCLUDE_JVMCI
1762   static ByteSize exception_oop_offset()         { return byte_offset_of(JavaThread, _exception_oop); }
1763   static ByteSize exception_pc_offset()          { return byte_offset_of(JavaThread, _exception_pc); }
1764   static ByteSize exception_handler_pc_offset()  { return byte_offset_of(JavaThread, _exception_handler_pc); }
1765   static ByteSize stack_overflow_limit_offset()  { return byte_offset_of(JavaThread, _stack_overflow_limit); }
1766   static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); }
1767   static ByteSize stack_guard_state_offset()     { return byte_offset_of(JavaThread, _stack_guard_state); }
1768   static ByteSize reserved_stack_activation_offset() { return byte_offset_of(JavaThread, _reserved_stack_activation); }
1769   static ByteSize suspend_flags_offset()         { return byte_offset_of(JavaThread, _suspend_flags); }
1770 
1771   static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
1772   static ByteSize should_post_on_exceptions_flag_offset() {
1773     return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
1774   }
1775   static ByteSize doing_unsafe_access_offset() { return byte_offset_of(JavaThread, _doing_unsafe_access); }
1776 
1777   // Returns the jni environment for this thread
1778   JNIEnv* jni_environment()                      { return &_jni_environment; }
1779 
1780   static JavaThread* thread_from_jni_environment(JNIEnv* env) {
1781     JavaThread *thread_from_jni_env = (JavaThread*)((intptr_t)env - in_bytes(jni_environment_offset()));
1782     // Only return NULL if thread is off the thread list; starting to
1783     // exit should not return NULL.
1784     if (thread_from_jni_env->is_terminated()) {
1785       thread_from_jni_env->block_if_vm_exited();
1786       return NULL;
1787     } else {
1788       return thread_from_jni_env;
1789     }
1790   }
1791 
1792   // JNI critical regions. These can nest.
1793   bool in_critical()    { return _jni_active_critical > 0; }
1794   bool in_last_critical()  { return _jni_active_critical == 1; }
1795   inline void enter_critical();
1796   void exit_critical() {
1797     assert(Thread::current() == this, "this must be current thread");
1798     _jni_active_critical--;
1799     assert(_jni_active_critical >= 0, "JNI critical nesting problem?");
1800   }
1801 
1802   // Checked JNI: is the programmer required to check for exceptions, if so specify
1803   // which function name. Returning to a Java frame should implicitly clear the
1804   // pending check, this is done for Native->Java transitions (i.e. user JNI code).
1805   // VM->Java transistions are not cleared, it is expected that JNI code enclosed
1806   // within ThreadToNativeFromVM makes proper exception checks (i.e. VM internal).
1807   bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != NULL; }
1808   void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = NULL; }
1809   const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; }
1810   void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; }
1811 
1812   // For deadlock detection
1813   int depth_first_number() { return _depth_first_number; }
1814   void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
1815 
1816  private:
1817   void set_monitor_chunks(MonitorChunk* monitor_chunks) { _monitor_chunks = monitor_chunks; }
1818 
1819  public:
1820   MonitorChunk* monitor_chunks() const           { return _monitor_chunks; }
1821   void add_monitor_chunk(MonitorChunk* chunk);
1822   void remove_monitor_chunk(MonitorChunk* chunk);
1823   bool in_deopt_handler() const                  { return _in_deopt_handler > 0; }
1824   void inc_in_deopt_handler()                    { _in_deopt_handler++; }
1825   void dec_in_deopt_handler() {
1826     assert(_in_deopt_handler > 0, "mismatched deopt nesting");
1827     if (_in_deopt_handler > 0) { // robustness
1828       _in_deopt_handler--;
1829     }
1830   }
1831 
1832  private:
1833   void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
1834 
1835  public:
1836 
1837   // Frame iteration; calls the function f for all frames on the stack
1838   void frames_do(void f(frame*, const RegisterMap*));
1839 
1840   // Memory operations
1841   void oops_do(OopClosure* f, CodeBlobClosure* cf);
1842 
1843   // Sweeper operations
1844   virtual void nmethods_do(CodeBlobClosure* cf);
1845 
1846   // RedefineClasses Support
1847   void metadata_do(MetadataClosure* f);
1848 
1849   // Debug method asserting thread states are correct during a handshake operation.
1850   DEBUG_ONLY(void verify_states_for_handshake();)
1851 
1852   // Misc. operations
1853   char* name() const { return (char*)get_thread_name(); }
1854   void print_on(outputStream* st, bool print_extended_info) const;
1855   void print_on(outputStream* st) const { print_on(st, false); }
1856   void print() const;
1857   void print_thread_state_on(outputStream*) const      PRODUCT_RETURN;
1858   void print_on_error(outputStream* st, char* buf, int buflen) const;
1859   void print_name_on_error(outputStream* st, char* buf, int buflen) const;
1860   void verify();
1861   const char* get_thread_name() const;
1862  protected:
1863   // factor out low-level mechanics for use in both normal and error cases
1864   virtual const char* get_thread_name_string(char* buf = NULL, int buflen = 0) const;
1865  public:
1866   // Accessing frames
1867   frame last_frame() {
1868     _anchor.make_walkable(this);
1869     return pd_last_frame();
1870   }
1871   javaVFrame* last_java_vframe(RegisterMap* reg_map);
1872 
1873   // Returns method at 'depth' java or native frames down the stack
1874   // Used for security checks
1875   Klass* security_get_caller_class(int depth);
1876 
1877   // Print stack trace in external format
1878   void print_stack_on(outputStream* st);
1879   void print_stack() { print_stack_on(tty); }
1880 
1881   // Print stack traces in various internal formats
1882   void trace_stack()                             PRODUCT_RETURN;
1883   void trace_stack_from(vframe* start_vf)        PRODUCT_RETURN;
1884   void trace_frames()                            PRODUCT_RETURN;
1885 
1886   // Print an annotated view of the stack frames
1887   void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN;
1888   void validate_frame_layout() {
1889     print_frame_layout(0, true);
1890   }
1891 
1892   // Function for testing deoptimization
1893   void deoptimize();
1894   void make_zombies();
1895 
1896   void deoptimize_marked_methods();
1897 
1898  public:
1899   // Returns the running thread as a JavaThread
1900   static inline JavaThread* current();
1901 
1902   // Returns the active Java thread.  Do not use this if you know you are calling
1903   // from a JavaThread, as it's slower than JavaThread::current.  If called from
1904   // the VMThread, it also returns the JavaThread that instigated the VMThread's
1905   // operation.  You may not want that either.
1906   static JavaThread* active();
1907 
1908   inline CompilerThread* as_CompilerThread();
1909 
1910  protected:
1911   virtual void pre_run();
1912   virtual void run();
1913   void thread_main_inner();
1914   virtual void post_run();
1915 
1916 
1917  private:
1918   GrowableArray<oop>* _array_for_gc;
1919  public:
1920 
1921   void register_array_for_gc(GrowableArray<oop>* array) { _array_for_gc = array; }
1922 
1923  public:
1924   // Thread local information maintained by JVMTI.
1925   void set_jvmti_thread_state(JvmtiThreadState *value)                           { _jvmti_thread_state = value; }
1926   // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1927   // getter is used to get this JavaThread's JvmtiThreadState if it has
1928   // one which means NULL can be returned. JvmtiThreadState::state_for()
1929   // is used to get the specified JavaThread's JvmtiThreadState if it has
1930   // one or it allocates a new JvmtiThreadState for the JavaThread and
1931   // returns it. JvmtiThreadState::state_for() will return NULL only if
1932   // the specified JavaThread is exiting.
1933   JvmtiThreadState *jvmti_thread_state() const                                   { return _jvmti_thread_state; }
1934   static ByteSize jvmti_thread_state_offset()                                    { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1935 
1936   // JVMTI PopFrame support
1937   // Setting and clearing popframe_condition
1938   // All of these enumerated values are bits. popframe_pending
1939   // indicates that a PopFrame() has been requested and not yet been
1940   // completed. popframe_processing indicates that that PopFrame() is in
1941   // the process of being completed. popframe_force_deopt_reexecution_bit
1942   // indicates that special handling is required when returning to a
1943   // deoptimized caller.
1944   enum PopCondition {
1945     popframe_inactive                      = 0x00,
1946     popframe_pending_bit                   = 0x01,
1947     popframe_processing_bit                = 0x02,
1948     popframe_force_deopt_reexecution_bit   = 0x04
1949   };
1950   PopCondition popframe_condition()                   { return (PopCondition) _popframe_condition; }
1951   void set_popframe_condition(PopCondition c)         { _popframe_condition = c; }
1952   void set_popframe_condition_bit(PopCondition c)     { _popframe_condition |= c; }
1953   void clear_popframe_condition()                     { _popframe_condition = popframe_inactive; }
1954   static ByteSize popframe_condition_offset()         { return byte_offset_of(JavaThread, _popframe_condition); }
1955   bool has_pending_popframe()                         { return (popframe_condition() & popframe_pending_bit) != 0; }
1956   bool popframe_forcing_deopt_reexecution()           { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
1957   void clear_popframe_forcing_deopt_reexecution()     { _popframe_condition &= ~popframe_force_deopt_reexecution_bit; }
1958 #ifdef CC_INTERP
1959   bool pop_frame_pending(void)                        { return ((_popframe_condition & popframe_pending_bit) != 0); }
1960   void clr_pop_frame_pending(void)                    { _popframe_condition = popframe_inactive; }
1961   bool pop_frame_in_process(void)                     { return ((_popframe_condition & popframe_processing_bit) != 0); }
1962   void set_pop_frame_in_process(void)                 { _popframe_condition |= popframe_processing_bit; }
1963   void clr_pop_frame_in_process(void)                 { _popframe_condition &= ~popframe_processing_bit; }
1964 #endif
1965 
1966   int frames_to_pop_failed_realloc() const            { return _frames_to_pop_failed_realloc; }
1967   void set_frames_to_pop_failed_realloc(int nb)       { _frames_to_pop_failed_realloc = nb; }
1968   void dec_frames_to_pop_failed_realloc()             { _frames_to_pop_failed_realloc--; }
1969 
1970  private:
1971   // Saved incoming arguments to popped frame.
1972   // Used only when popped interpreted frame returns to deoptimized frame.
1973   void*    _popframe_preserved_args;
1974   int      _popframe_preserved_args_size;
1975 
1976  public:
1977   void  popframe_preserve_args(ByteSize size_in_bytes, void* start);
1978   void* popframe_preserved_args();
1979   ByteSize popframe_preserved_args_size();
1980   WordSize popframe_preserved_args_size_in_words();
1981   void  popframe_free_preserved_args();
1982 
1983 
1984  private:
1985   JvmtiThreadState *_jvmti_thread_state;
1986 
1987   // Used by the interpreter in fullspeed mode for frame pop, method
1988   // entry, method exit and single stepping support. This field is
1989   // only set to non-zero by the VM_EnterInterpOnlyMode VM operation.
1990   // It can be set to zero asynchronously (i.e., without a VM operation
1991   // or a lock) so we have to be very careful.
1992   int               _interp_only_mode;
1993 
1994  public:
1995   // used by the interpreter for fullspeed debugging support (see above)
1996   static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
1997   bool is_interp_only_mode()                { return (_interp_only_mode != 0); }
1998   int get_interp_only_mode()                { return _interp_only_mode; }
1999   void increment_interp_only_mode()         { ++_interp_only_mode; }
2000   void decrement_interp_only_mode()         { --_interp_only_mode; }
2001 
2002   // support for cached flag that indicates whether exceptions need to be posted for this thread
2003   // if this is false, we can avoid deoptimizing when events are thrown
2004   // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
2005  private:
2006   int    _should_post_on_exceptions_flag;
2007 
2008  public:
2009   int   should_post_on_exceptions_flag()  { return _should_post_on_exceptions_flag; }
2010   void  set_should_post_on_exceptions_flag(int val)  { _should_post_on_exceptions_flag = val; }
2011 
2012  private:
2013   ThreadStatistics *_thread_stat;
2014 
2015  public:
2016   ThreadStatistics* get_thread_stat() const    { return _thread_stat; }
2017 
2018   // Return a blocker object for which this thread is blocked parking.
2019   oop current_park_blocker();
2020 
2021  private:
2022   static size_t _stack_size_at_create;
2023 
2024  public:
2025   static inline size_t stack_size_at_create(void) {
2026     return _stack_size_at_create;
2027   }
2028   static inline void set_stack_size_at_create(size_t value) {
2029     _stack_size_at_create = value;
2030   }
2031 
2032   // Machine dependent stuff
2033 #include OS_CPU_HEADER(thread)
2034 
2035   // JSR166 per-thread parker
2036  private:
2037   Parker*    _parker;
2038  public:
2039   Parker*     parker() { return _parker; }
2040 
2041   // Biased locking support
2042  private:
2043   GrowableArray<MonitorInfo*>* _cached_monitor_info;
2044  public:
2045   GrowableArray<MonitorInfo*>* cached_monitor_info() { return _cached_monitor_info; }
2046   void set_cached_monitor_info(GrowableArray<MonitorInfo*>* info) { _cached_monitor_info = info; }
2047 
2048   // clearing/querying jni attach status
2049   bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; }
2050   bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
2051   inline void set_done_attaching_via_jni();
2052 
2053   // Stack dump assistance:
2054   // Track the class we want to initialize but for which we have to wait
2055   // on its init_lock() because it is already being initialized.
2056   void set_class_to_be_initialized(InstanceKlass* k);
2057   InstanceKlass* class_to_be_initialized() const;
2058 
2059 private:
2060   InstanceKlass* _class_to_be_initialized;
2061 
2062   // java.lang.Thread.sleep support
2063   ParkEvent * _SleepEvent;
2064 public:
2065   bool sleep(jlong millis);
2066 
2067   // java.lang.Thread interruption support
2068   void interrupt();
2069   bool is_interrupted(bool clear_interrupted);
2070 
2071 };
2072 
2073 // Inline implementation of JavaThread::current
2074 inline JavaThread* JavaThread::current() {
2075   Thread* thread = Thread::current();
2076   assert(thread->is_Java_thread(), "just checking");
2077   return (JavaThread*)thread;
2078 }
2079 
2080 inline CompilerThread* JavaThread::as_CompilerThread() {
2081   assert(is_Compiler_thread(), "just checking");
2082   return (CompilerThread*)this;
2083 }
2084 
2085 // Dedicated thread to sweep the code cache
2086 class CodeCacheSweeperThread : public JavaThread {
2087   CompiledMethod*       _scanned_compiled_method; // nmethod being scanned by the sweeper
2088  public:
2089   CodeCacheSweeperThread();
2090   // Track the nmethod currently being scanned by the sweeper
2091   void set_scanned_compiled_method(CompiledMethod* cm) {
2092     assert(_scanned_compiled_method == NULL || cm == NULL, "should reset to NULL before writing a new value");
2093     _scanned_compiled_method = cm;
2094   }
2095 
2096   // Hide sweeper thread from external view.
2097   bool is_hidden_from_external_view() const { return true; }
2098 
2099   bool is_Code_cache_sweeper_thread() const { return true; }
2100 
2101   // Prevent GC from unloading _scanned_compiled_method
2102   void oops_do(OopClosure* f, CodeBlobClosure* cf);
2103   void nmethods_do(CodeBlobClosure* cf);
2104 };
2105 
2106 // A thread used for Compilation.
2107 class CompilerThread : public JavaThread {
2108   friend class VMStructs;
2109  private:
2110   CompilerCounters* _counters;
2111 
2112   ciEnv*                _env;
2113   CompileLog*           _log;
2114   CompileTask* volatile _task;  // print_threads_compiling can read this concurrently.
2115   CompileQueue*         _queue;
2116   BufferBlob*           _buffer_blob;
2117 
2118   AbstractCompiler*     _compiler;
2119   TimeStamp             _idle_time;
2120 
2121  public:
2122 
2123   static CompilerThread* current();
2124 
2125   CompilerThread(CompileQueue* queue, CompilerCounters* counters);
2126   ~CompilerThread();
2127 
2128   bool is_Compiler_thread() const                { return true; }
2129 
2130   virtual bool can_call_java() const;
2131 
2132   // Hide native compiler threads from external view.
2133   bool is_hidden_from_external_view() const      { return !can_call_java(); }
2134 
2135   void set_compiler(AbstractCompiler* c)         { _compiler = c; }
2136   AbstractCompiler* compiler() const             { return _compiler; }
2137 
2138   CompileQueue* queue()        const             { return _queue; }
2139   CompilerCounters* counters() const             { return _counters; }
2140 
2141   // Get/set the thread's compilation environment.
2142   ciEnv*        env()                            { return _env; }
2143   void          set_env(ciEnv* env)              { _env = env; }
2144 
2145   BufferBlob*   get_buffer_blob() const          { return _buffer_blob; }
2146   void          set_buffer_blob(BufferBlob* b)   { _buffer_blob = b; }
2147 
2148   // Get/set the thread's logging information
2149   CompileLog*   log()                            { return _log; }
2150   void          init_log(CompileLog* log) {
2151     // Set once, for good.
2152     assert(_log == NULL, "set only once");
2153     _log = log;
2154   }
2155 
2156   void start_idle_timer()                        { _idle_time.update(); }
2157   jlong idle_time_millis() {
2158     return TimeHelper::counter_to_millis(_idle_time.ticks_since_update());
2159   }
2160 
2161 #ifndef PRODUCT
2162  private:
2163   IdealGraphPrinter *_ideal_graph_printer;
2164  public:
2165   IdealGraphPrinter *ideal_graph_printer()           { return _ideal_graph_printer; }
2166   void set_ideal_graph_printer(IdealGraphPrinter *n) { _ideal_graph_printer = n; }
2167 #endif
2168 
2169   // Get/set the thread's current task
2170   CompileTask* task()                      { return _task; }
2171   void         set_task(CompileTask* task) { _task = task; }
2172 };
2173 
2174 inline CompilerThread* CompilerThread::current() {
2175   return JavaThread::current()->as_CompilerThread();
2176 }
2177 
2178 // The active thread queue. It also keeps track of the current used
2179 // thread priorities.
2180 class Threads: AllStatic {
2181   friend class VMStructs;
2182  private:
2183   static int         _number_of_threads;
2184   static int         _number_of_non_daemon_threads;
2185   static int         _return_code;
2186   static uintx       _thread_claim_token;
2187 #ifdef ASSERT
2188   static bool        _vm_complete;
2189 #endif
2190 
2191   static void initialize_java_lang_classes(JavaThread* main_thread, TRAPS);
2192   static void initialize_jsr292_core_classes(TRAPS);
2193 
2194  public:
2195   // Thread management
2196   // force_daemon is a concession to JNI, where we may need to add a
2197   // thread to the thread list before allocating its thread object
2198   static void add(JavaThread* p, bool force_daemon = false);
2199   static void remove(JavaThread* p, bool is_daemon);
2200   static void non_java_threads_do(ThreadClosure* tc);
2201   static void java_threads_do(ThreadClosure* tc);
2202   static void java_threads_and_vm_thread_do(ThreadClosure* tc);
2203   static void threads_do(ThreadClosure* tc);
2204   static void possibly_parallel_threads_do(bool is_par, ThreadClosure* tc);
2205 
2206   // Initializes the vm and creates the vm thread
2207   static jint create_vm(JavaVMInitArgs* args, bool* canTryAgain);
2208   static void convert_vm_init_libraries_to_agents();
2209   static void create_vm_init_libraries();
2210   static void create_vm_init_agents();
2211   static void shutdown_vm_agents();
2212   static bool destroy_vm();
2213   // Supported VM versions via JNI
2214   // Includes JNI_VERSION_1_1
2215   static jboolean is_supported_jni_version_including_1_1(jint version);
2216   // Does not include JNI_VERSION_1_1
2217   static jboolean is_supported_jni_version(jint version);
2218 
2219   // The "thread claim token" provides a way for threads to be claimed
2220   // by parallel worker tasks.
2221   //
2222   // Each thread contains a "token" field. A task will claim the
2223   // thread only if its token is different from the global token,
2224   // which is updated by calling change_thread_claim_token().  When
2225   // a thread is claimed, it's token is set to the global token value
2226   // so other threads in the same iteration pass won't claim it.
2227   //
2228   // For this to work change_thread_claim_token() needs to be called
2229   // exactly once in sequential code before starting parallel tasks
2230   // that should claim threads.
2231   //
2232   // New threads get their token set to 0 and change_thread_claim_token()
2233   // never sets the global token to 0.
2234   static uintx thread_claim_token() { return _thread_claim_token; }
2235   static void change_thread_claim_token();
2236   static void assert_all_threads_claimed() NOT_DEBUG_RETURN;
2237 
2238   // Apply "f->do_oop" to all root oops in all threads.
2239   // This version may only be called by sequential code.
2240   static void oops_do(OopClosure* f, CodeBlobClosure* cf);
2241   // This version may be called by sequential or parallel code.
2242   static void possibly_parallel_oops_do(bool is_par, OopClosure* f, CodeBlobClosure* cf);
2243 
2244   // Sweeper
2245   static void nmethods_do(CodeBlobClosure* cf);
2246 
2247   // RedefineClasses support
2248   static void metadata_do(MetadataClosure* f);
2249   static void metadata_handles_do(void f(Metadata*));
2250 
2251 #ifdef ASSERT
2252   static bool is_vm_complete() { return _vm_complete; }
2253 #endif // ASSERT
2254 
2255   // Verification
2256   static void verify();
2257   static void print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks, bool print_extended_info);
2258   static void print(bool print_stacks, bool internal_format) {
2259     // this function is only used by debug.cpp
2260     print_on(tty, print_stacks, internal_format, false /* no concurrent lock printed */, false /* simple format */);
2261   }
2262   static void print_on_error(outputStream* st, Thread* current, char* buf, int buflen);
2263   static void print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
2264                              int buflen, bool* found_current);
2265   static void print_threads_compiling(outputStream* st, char* buf, int buflen, bool short_form = false);
2266 
2267   // Get Java threads that are waiting to enter a monitor.
2268   static GrowableArray<JavaThread*>* get_pending_threads(ThreadsList * t_list,
2269                                                          int count, address monitor);
2270 
2271   // Get owning Java thread from the monitor's owner field.
2272   static JavaThread *owning_thread_from_monitor_owner(ThreadsList * t_list,
2273                                                       address owner);
2274 
2275   // Number of threads on the active threads list
2276   static int number_of_threads()                 { return _number_of_threads; }
2277   // Number of non-daemon threads on the active threads list
2278   static int number_of_non_daemon_threads()      { return _number_of_non_daemon_threads; }
2279 
2280   // Deoptimizes all frames tied to marked nmethods
2281   static void deoptimized_wrt_marked_nmethods();
2282 
2283   struct Test;                  // For private gtest access.
2284 };
2285 
2286 
2287 // Thread iterator
2288 class ThreadClosure: public StackObj {
2289  public:
2290   virtual void do_thread(Thread* thread) = 0;
2291 };
2292 
2293 class SignalHandlerMark: public StackObj {
2294  private:
2295   Thread* _thread;
2296  public:
2297   SignalHandlerMark(Thread* t) {
2298     _thread = t;
2299     if (_thread) _thread->enter_signal_handler();
2300   }
2301   ~SignalHandlerMark() {
2302     if (_thread) _thread->leave_signal_handler();
2303     _thread = NULL;
2304   }
2305 };
2306 
2307 
2308 #endif // SHARE_RUNTIME_THREAD_HPP
--- EOF ---