1 /*
   2  * Copyright (c) 1997, 2015, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_RUNTIME_THREAD_HPP
  26 #define SHARE_VM_RUNTIME_THREAD_HPP
  27 
  28 #include "memory/allocation.hpp"
  29 #include "memory/threadLocalAllocBuffer.hpp"
  30 #include "oops/oop.hpp"
  31 #include "prims/jni.h"
  32 #include "prims/jvmtiExport.hpp"
  33 #include "runtime/frame.hpp"
  34 #include "runtime/javaFrameAnchor.hpp"
  35 #include "runtime/jniHandles.hpp"
  36 #include "runtime/mutexLocker.hpp"
  37 #include "runtime/os.hpp"
  38 #include "runtime/osThread.hpp"
  39 #include "runtime/park.hpp"
  40 #include "runtime/safepoint.hpp"
  41 #include "runtime/stubRoutines.hpp"
  42 #include "runtime/threadLocalStorage.hpp"
  43 #include "runtime/thread_ext.hpp"
  44 #include "runtime/unhandledOops.hpp"
  45 #include "trace/traceBackend.hpp"
  46 #include "trace/traceMacros.hpp"
  47 #include "utilities/exceptions.hpp"
  48 #include "utilities/macros.hpp"
  49 #include "utilities/top.hpp"
  50 #if INCLUDE_ALL_GCS
  51 #include "gc_implementation/g1/dirtyCardQueue.hpp"
  52 #include "gc_implementation/g1/satbQueue.hpp"
  53 #endif // INCLUDE_ALL_GCS
  54 #ifdef ZERO
  55 #ifdef TARGET_ARCH_zero
  56 # include "stack_zero.hpp"
  57 #endif
  58 #endif
  59 
  60 class ThreadSafepointState;
  61 class ThreadProfiler;
  62 
  63 class JvmtiThreadState;
  64 class JvmtiGetLoadedClassesClosure;
  65 class ThreadStatistics;
  66 class ConcurrentLocksDump;
  67 class ParkEvent;
  68 class Parker;
  69 
  70 class ciEnv;
  71 class CompileThread;
  72 class CompileLog;
  73 class CompileTask;
  74 class CompileQueue;
  75 class CompilerCounters;
  76 class vframeArray;
  77 
  78 class DeoptResourceMark;
  79 class jvmtiDeferredLocalVariableSet;
  80 
  81 class GCTaskQueue;
  82 class ThreadClosure;
  83 class IdealGraphPrinter;
  84 
  85 class Metadata;
  86 template <class T, MEMFLAGS F> class ChunkedList;
  87 typedef ChunkedList<Metadata*, mtInternal> MetadataOnStackBuffer;
  88 
  89 DEBUG_ONLY(class ResourceMark;)
  90 
  91 class WorkerThread;
  92 
  93 // Class hierarchy
  94 // - Thread
  95 //   - NamedThread
  96 //     - VMThread
  97 //     - ConcurrentGCThread
  98 //     - WorkerThread
  99 //       - GangWorker
 100 //       - GCTaskThread
 101 //   - JavaThread
 102 //   - WatcherThread
 103 
 104 class Thread: public ThreadShadow {
 105   friend class VMStructs;
 106  private:
 107   // Exception handling
 108   // (Note: _pending_exception and friends are in ThreadShadow)
 109   //oop       _pending_exception;                // pending exception for current thread
 110   // const char* _exception_file;                   // file information for exception (debugging only)
 111   // int         _exception_line;                   // line information for exception (debugging only)
 112  protected:
 113   // Support for forcing alignment of thread objects for biased locking
 114   void*       _real_malloc_address;
 115  public:
 116   void* operator new(size_t size) throw() { return allocate(size, true); }
 117   void* operator new(size_t size, const std::nothrow_t& nothrow_constant) throw() {
 118     return allocate(size, false); }
 119   void  operator delete(void* p);
 120 
 121  protected:
 122   static void* allocate(size_t size, bool throw_excpt, MEMFLAGS flags = mtThread);
 123  private:
 124 
 125   // ***************************************************************
 126   // Suspend and resume support
 127   // ***************************************************************
 128   //
 129   // VM suspend/resume no longer exists - it was once used for various
 130   // things including safepoints but was deprecated and finally removed
 131   // in Java 7. Because VM suspension was considered "internal" Java-level
 132   // suspension was considered "external", and this legacy naming scheme
 133   // remains.
 134   //
 135   // External suspend/resume requests come from JVM_SuspendThread,
 136   // JVM_ResumeThread, JVMTI SuspendThread, and finally JVMTI
 137   // ResumeThread. External
 138   // suspend requests cause _external_suspend to be set and external
 139   // resume requests cause _external_suspend to be cleared.
 140   // External suspend requests do not nest on top of other external
 141   // suspend requests. The higher level APIs reject suspend requests
 142   // for already suspended threads.
 143   //
 144   // The external_suspend
 145   // flag is checked by has_special_runtime_exit_condition() and java thread
 146   // will self-suspend when handle_special_runtime_exit_condition() is
 147   // called. Most uses of the _thread_blocked state in JavaThreads are
 148   // considered the same as being externally suspended; if the blocking
 149   // condition lifts, the JavaThread will self-suspend. Other places
 150   // where VM checks for external_suspend include:
 151   //   + mutex granting (do not enter monitors when thread is suspended)
 152   //   + state transitions from _thread_in_native
 153   //
 154   // In general, java_suspend() does not wait for an external suspend
 155   // request to complete. When it returns, the only guarantee is that
 156   // the _external_suspend field is true.
 157   //
 158   // wait_for_ext_suspend_completion() is used to wait for an external
 159   // suspend request to complete. External suspend requests are usually
 160   // followed by some other interface call that requires the thread to
 161   // be quiescent, e.g., GetCallTrace(). By moving the "wait time" into
 162   // the interface that requires quiescence, we give the JavaThread a
 163   // chance to self-suspend before we need it to be quiescent. This
 164   // improves overall suspend/query performance.
 165   //
 166   // _suspend_flags controls the behavior of java_ suspend/resume.
 167   // It must be set under the protection of SR_lock. Read from the flag is
 168   // OK without SR_lock as long as the value is only used as a hint.
 169   // (e.g., check _external_suspend first without lock and then recheck
 170   // inside SR_lock and finish the suspension)
 171   //
 172   // _suspend_flags is also overloaded for other "special conditions" so
 173   // that a single check indicates whether any special action is needed
 174   // eg. for async exceptions.
 175   // -------------------------------------------------------------------
 176   // Notes:
 177   // 1. The suspend/resume logic no longer uses ThreadState in OSThread
 178   // but we still update its value to keep other part of the system (mainly
 179   // JVMTI) happy. ThreadState is legacy code (see notes in
 180   // osThread.hpp).
 181   //
 182   // 2. It would be more natural if set_external_suspend() is private and
 183   // part of java_suspend(), but that probably would affect the suspend/query
 184   // performance. Need more investigation on this.
 185 
 186   // suspend/resume lock: used for self-suspend
 187   Monitor* _SR_lock;
 188 
 189  protected:
 190   enum SuspendFlags {
 191     // NOTE: avoid using the sign-bit as cc generates different test code
 192     //       when the sign-bit is used, and sometimes incorrectly - see CR 6398077
 193 
 194     _external_suspend       = 0x20000000U, // thread is asked to self suspend
 195     _ext_suspended          = 0x40000000U, // thread has self-suspended
 196     _deopt_suspend          = 0x10000000U, // thread needs to self suspend for deopt
 197 
 198     _has_async_exception    = 0x00000001U, // there is a pending async exception
 199     _critical_native_unlock = 0x00000002U  // Must call back to unlock JNI critical lock
 200   };
 201 
 202   // various suspension related flags - atomically updated
 203   // overloaded for async exception checking in check_special_condition_for_native_trans.
 204   volatile uint32_t _suspend_flags;
 205 
 206  private:
 207   int _num_nested_signal;
 208 
 209  public:
 210   void enter_signal_handler() { _num_nested_signal++; }
 211   void leave_signal_handler() { _num_nested_signal--; }
 212   bool is_inside_signal_handler() const { return _num_nested_signal > 0; }
 213 
 214  private:
 215   // Active_handles points to a block of handles
 216   JNIHandleBlock* _active_handles;
 217 
 218   // One-element thread local free list
 219   JNIHandleBlock* _free_handle_block;
 220 
 221   // Point to the last handle mark
 222   HandleMark* _last_handle_mark;
 223 
 224   // The parity of the last strong_roots iteration in which this thread was
 225   // claimed as a task.
 226   jint _oops_do_parity;
 227 
 228  public:
 229   void set_last_handle_mark(HandleMark* mark)   { _last_handle_mark = mark; }
 230   HandleMark* last_handle_mark() const          { return _last_handle_mark; }
 231  private:
 232 
 233   // debug support for checking if code does allow safepoints or not
 234   // GC points in the VM can happen because of allocation, invoking a VM operation, or blocking on
 235   // mutex, or blocking on an object synchronizer (Java locking).
 236   // If !allow_safepoint(), then an assertion failure will happen in any of the above cases
 237   // If !allow_allocation(), then an assertion failure will happen during allocation
 238   // (Hence, !allow_safepoint() => !allow_allocation()).
 239   //
 240   // The two classes No_Safepoint_Verifier and No_Allocation_Verifier are used to set these counters.
 241   //
 242   NOT_PRODUCT(int _allow_safepoint_count;)      // If 0, thread allow a safepoint to happen
 243   debug_only(int _allow_allocation_count;)     // If 0, the thread is allowed to allocate oops.
 244 
 245   // Used by SkipGCALot class.
 246   NOT_PRODUCT(bool _skip_gcalot;)               // Should we elide gc-a-lot?
 247 
 248   friend class No_Alloc_Verifier;
 249   friend class No_Safepoint_Verifier;
 250   friend class Pause_No_Safepoint_Verifier;
 251   friend class ThreadLocalStorage;
 252   friend class GC_locker;
 253 
 254   ThreadLocalAllocBuffer _tlab;                 // Thread-local eden
 255   jlong _allocated_bytes;                       // Cumulative number of bytes allocated on
 256                                                 // the Java heap
 257 
 258   TRACE_DATA _trace_data;                       // Thread-local data for tracing
 259 
 260   ThreadExt _ext;
 261 
 262   int   _vm_operation_started_count;            // VM_Operation support
 263   int   _vm_operation_completed_count;          // VM_Operation support
 264 
 265   ObjectMonitor* _current_pending_monitor;      // ObjectMonitor this thread
 266                                                 // is waiting to lock
 267   bool _current_pending_monitor_is_from_java;   // locking is from Java code
 268 
 269   // ObjectMonitor on which this thread called Object.wait()
 270   ObjectMonitor* _current_waiting_monitor;
 271 
 272   // Private thread-local objectmonitor list - a simple cache organized as a SLL.
 273  public:
 274   ObjectMonitor* omFreeList;
 275   int omFreeCount;                              // length of omFreeList
 276   int omFreeProvision;                          // reload chunk size
 277   ObjectMonitor* omInUseList;                   // SLL to track monitors in circulation
 278   int omInUseCount;                             // length of omInUseList
 279 
 280 #ifdef ASSERT
 281  private:
 282   bool _visited_for_critical_count;
 283 
 284  public:
 285   void set_visited_for_critical_count(bool z) { _visited_for_critical_count = z; }
 286   bool was_visited_for_critical_count() const   { return _visited_for_critical_count; }
 287 #endif
 288 
 289  public:
 290   enum {
 291     is_definitely_current_thread = true
 292   };
 293 
 294   // Constructor
 295   Thread();
 296   virtual ~Thread();
 297 
 298   // initializtion
 299   void initialize_thread_local_storage();
 300 
 301   // thread entry point
 302   virtual void run();
 303 
 304   // Testers
 305   virtual bool is_VM_thread()       const            { return false; }
 306   virtual bool is_Java_thread()     const            { return false; }
 307   virtual bool is_Compiler_thread() const            { return false; }
 308   virtual bool is_Code_cache_sweeper_thread() const  { return false; }
 309   virtual bool is_hidden_from_external_view() const  { return false; }
 310   virtual bool is_jvmti_agent_thread() const         { return false; }
 311   // True iff the thread can perform GC operations at a safepoint.
 312   // Generally will be true only of VM thread and parallel GC WorkGang
 313   // threads.
 314   virtual bool is_GC_task_thread() const             { return false; }
 315   virtual bool is_Watcher_thread() const             { return false; }
 316   virtual bool is_ConcurrentGC_thread() const        { return false; }
 317   virtual bool is_Named_thread() const               { return false; }
 318   virtual bool is_Worker_thread() const              { return false; }
 319 
 320   // Casts
 321   virtual WorkerThread* as_Worker_thread() const     { return NULL; }
 322 
 323   virtual char* name() const { return (char*)"Unknown thread"; }
 324 
 325   // Returns the current thread
 326   static inline Thread* current();
 327 
 328   // Common thread operations
 329   static void set_priority(Thread* thread, ThreadPriority priority);
 330   static ThreadPriority get_priority(const Thread* const thread);
 331   static void start(Thread* thread);
 332   static void interrupt(Thread* thr);
 333   static bool is_interrupted(Thread* thr, bool clear_interrupted);
 334 
 335   void set_native_thread_name(const char *name) {
 336     assert(Thread::current() == this, "set_native_thread_name can only be called on the current thread");
 337     os::set_native_thread_name(name);
 338   }
 339 
 340   ObjectMonitor** omInUseList_addr()             { return (ObjectMonitor **)&omInUseList; }
 341   Monitor* SR_lock() const                       { return _SR_lock; }
 342 
 343   bool has_async_exception() const { return (_suspend_flags & _has_async_exception) != 0; }
 344 
 345   inline void set_suspend_flag(SuspendFlags f);
 346   inline void clear_suspend_flag(SuspendFlags f);
 347 
 348   inline void set_has_async_exception();
 349   inline void clear_has_async_exception();
 350 
 351   bool do_critical_native_unlock() const { return (_suspend_flags & _critical_native_unlock) != 0; }
 352 
 353   inline void set_critical_native_unlock();
 354   inline void clear_critical_native_unlock();
 355 
 356   // Support for Unhandled Oop detection
 357 #ifdef CHECK_UNHANDLED_OOPS
 358  private:
 359   UnhandledOops* _unhandled_oops;
 360  public:
 361   UnhandledOops* unhandled_oops() { return _unhandled_oops; }
 362   // Mark oop safe for gc.  It may be stack allocated but won't move.
 363   void allow_unhandled_oop(oop *op) {
 364     if (CheckUnhandledOops) unhandled_oops()->allow_unhandled_oop(op);
 365   }
 366   // Clear oops at safepoint so crashes point to unhandled oop violator
 367   void clear_unhandled_oops() {
 368     if (CheckUnhandledOops) unhandled_oops()->clear_unhandled_oops();
 369   }
 370 #endif // CHECK_UNHANDLED_OOPS
 371 
 372 #ifndef PRODUCT
 373   bool skip_gcalot()           { return _skip_gcalot; }
 374   void set_skip_gcalot(bool v) { _skip_gcalot = v;    }
 375 #endif
 376 
 377  public:
 378   // Installs a pending exception to be inserted later
 379   static void send_async_exception(oop thread_oop, oop java_throwable);
 380 
 381   // Resource area
 382   ResourceArea* resource_area() const            { return _resource_area; }
 383   void set_resource_area(ResourceArea* area)     { _resource_area = area; }
 384 
 385   OSThread* osthread() const                     { return _osthread;   }
 386   void set_osthread(OSThread* thread)            { _osthread = thread; }
 387 
 388   // JNI handle support
 389   JNIHandleBlock* active_handles() const         { return _active_handles; }
 390   void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
 391   JNIHandleBlock* free_handle_block() const      { return _free_handle_block; }
 392   void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
 393 
 394   // Internal handle support
 395   HandleArea* handle_area() const                { return _handle_area; }
 396   void set_handle_area(HandleArea* area)         { _handle_area = area; }
 397 
 398   GrowableArray<Metadata*>* metadata_handles() const          { return _metadata_handles; }
 399   void set_metadata_handles(GrowableArray<Metadata*>* handles){ _metadata_handles = handles; }
 400 
 401   // Thread-Local Allocation Buffer (TLAB) support
 402   ThreadLocalAllocBuffer& tlab()                 { return _tlab; }
 403   void initialize_tlab() {
 404     if (UseTLAB) {
 405       tlab().initialize();
 406     }
 407   }
 408 
 409   jlong allocated_bytes()               { return _allocated_bytes; }
 410   void set_allocated_bytes(jlong value) { _allocated_bytes = value; }
 411   void incr_allocated_bytes(jlong size) { _allocated_bytes += size; }
 412   inline jlong cooked_allocated_bytes();
 413 
 414   TRACE_DATA* trace_data()              { return &_trace_data; }
 415 
 416   const ThreadExt& ext() const          { return _ext; }
 417   ThreadExt& ext()                      { return _ext; }
 418 
 419   // VM operation support
 420   int vm_operation_ticket()                      { return ++_vm_operation_started_count; }
 421   int vm_operation_completed_count()             { return _vm_operation_completed_count; }
 422   void increment_vm_operation_completed_count()  { _vm_operation_completed_count++; }
 423 
 424   // For tracking the heavyweight monitor the thread is pending on.
 425   ObjectMonitor* current_pending_monitor() {
 426     return _current_pending_monitor;
 427   }
 428   void set_current_pending_monitor(ObjectMonitor* monitor) {
 429     _current_pending_monitor = monitor;
 430   }
 431   void set_current_pending_monitor_is_from_java(bool from_java) {
 432     _current_pending_monitor_is_from_java = from_java;
 433   }
 434   bool current_pending_monitor_is_from_java() {
 435     return _current_pending_monitor_is_from_java;
 436   }
 437 
 438   // For tracking the ObjectMonitor on which this thread called Object.wait()
 439   ObjectMonitor* current_waiting_monitor() {
 440     return _current_waiting_monitor;
 441   }
 442   void set_current_waiting_monitor(ObjectMonitor* monitor) {
 443     _current_waiting_monitor = monitor;
 444   }
 445 
 446   // GC support
 447   // Apply "f->do_oop" to all root oops in "this".
 448   // Apply "cld_f->do_cld" to CLDs that are otherwise not kept alive.
 449   //   Used by JavaThread::oops_do.
 450   // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames
 451   virtual void oops_do(OopClosure* f, CLDClosure* cld_f, CodeBlobClosure* cf);
 452 
 453   // Handles the parallel case for the method below.
 454  private:
 455   bool claim_oops_do_par_case(int collection_parity);
 456  public:
 457   // Requires that "collection_parity" is that of the current roots
 458   // iteration.  If "is_par" is false, sets the parity of "this" to
 459   // "collection_parity", and returns "true".  If "is_par" is true,
 460   // uses an atomic instruction to set the current threads parity to
 461   // "collection_parity", if it is not already.  Returns "true" iff the
 462   // calling thread does the update, this indicates that the calling thread
 463   // has claimed the thread's stack as a root groop in the current
 464   // collection.
 465   bool claim_oops_do(bool is_par, int collection_parity) {
 466     if (!is_par) {
 467       _oops_do_parity = collection_parity;
 468       return true;
 469     } else {
 470       return claim_oops_do_par_case(collection_parity);
 471     }
 472   }
 473 
 474   // Sweeper support
 475   void nmethods_do(CodeBlobClosure* cf);
 476 
 477   // jvmtiRedefineClasses support
 478   void metadata_handles_do(void f(Metadata*));
 479 
 480   // Used by fast lock support
 481   virtual bool is_lock_owned(address adr) const;
 482 
 483   // Check if address is in the stack of the thread (not just for locks).
 484   // Warning: the method can only be used on the running thread
 485   bool is_in_stack(address adr) const;
 486   // Check if address is in the usable part of the stack (excludes protected
 487   // guard pages)
 488   bool is_in_usable_stack(address adr) const;
 489 
 490   // Sets this thread as starting thread. Returns failure if thread
 491   // creation fails due to lack of memory, too many threads etc.
 492   bool set_as_starting_thread();
 493 
 494 protected:
 495   // OS data associated with the thread
 496   OSThread* _osthread;  // Platform-specific thread information
 497 
 498   // Thread local resource area for temporary allocation within the VM
 499   ResourceArea* _resource_area;
 500 
 501   DEBUG_ONLY(ResourceMark* _current_resource_mark;)
 502 
 503   // Thread local handle area for allocation of handles within the VM
 504   HandleArea* _handle_area;
 505   GrowableArray<Metadata*>* _metadata_handles;
 506 
 507   // Support for stack overflow handling, get_thread, etc.
 508   address          _stack_base;
 509   size_t           _stack_size;
 510   uintptr_t        _self_raw_id;      // used by get_thread (mutable)
 511   int              _lgrp_id;
 512 
 513  public:
 514   // Stack overflow support
 515   address stack_base() const           { assert(_stack_base != NULL,"Sanity check"); return _stack_base; }
 516 
 517   void    set_stack_base(address base) { _stack_base = base; }
 518   size_t  stack_size() const           { return _stack_size; }
 519   void    set_stack_size(size_t size)  { _stack_size = size; }
 520   void    record_stack_base_and_size();
 521 
 522   bool    on_local_stack(address adr) const {
 523     // QQQ this has knowledge of direction, ought to be a stack method
 524     return (_stack_base >= adr && adr >= (_stack_base - _stack_size));
 525   }
 526 
 527   uintptr_t self_raw_id()                    { return _self_raw_id; }
 528   void      set_self_raw_id(uintptr_t value) { _self_raw_id = value; }
 529 
 530   int     lgrp_id() const        { return _lgrp_id; }
 531   void    set_lgrp_id(int value) { _lgrp_id = value; }
 532 
 533   // Printing
 534   virtual void print_on(outputStream* st) const;
 535   void print() const { print_on(tty); }
 536   virtual void print_on_error(outputStream* st, char* buf, int buflen) const;
 537 
 538   // Debug-only code
 539 #ifdef ASSERT
 540  private:
 541   // Deadlock detection support for Mutex locks. List of locks own by thread.
 542   Monitor* _owned_locks;
 543   // Mutex::set_owner_implementation is the only place where _owned_locks is modified,
 544   // thus the friendship
 545   friend class Mutex;
 546   friend class Monitor;
 547 
 548  public:
 549   void print_owned_locks_on(outputStream* st) const;
 550   void print_owned_locks() const                 { print_owned_locks_on(tty);    }
 551   Monitor* owned_locks() const                   { return _owned_locks;          }
 552   bool owns_locks() const                        { return owned_locks() != NULL; }
 553   bool owns_locks_but_compiled_lock() const;
 554   int oops_do_parity() const                     { return _oops_do_parity; }
 555 
 556   // Deadlock detection
 557   bool allow_allocation()                        { return _allow_allocation_count == 0; }
 558   ResourceMark* current_resource_mark()          { return _current_resource_mark; }
 559   void set_current_resource_mark(ResourceMark* rm) { _current_resource_mark = rm; }
 560 #endif
 561 
 562   void check_for_valid_safepoint_state(bool potential_vm_operation) PRODUCT_RETURN;
 563 
 564  private:
 565   volatile int _jvmti_env_iteration_count;
 566 
 567  public:
 568   void entering_jvmti_env_iteration()            { ++_jvmti_env_iteration_count; }
 569   void leaving_jvmti_env_iteration()             { --_jvmti_env_iteration_count; }
 570   bool is_inside_jvmti_env_iteration()           { return _jvmti_env_iteration_count > 0; }
 571 
 572   // Code generation
 573   static ByteSize exception_file_offset()        { return byte_offset_of(Thread, _exception_file); }
 574   static ByteSize exception_line_offset()        { return byte_offset_of(Thread, _exception_line); }
 575   static ByteSize active_handles_offset()        { return byte_offset_of(Thread, _active_handles); }
 576 
 577   static ByteSize stack_base_offset()            { return byte_offset_of(Thread, _stack_base); }
 578   static ByteSize stack_size_offset()            { return byte_offset_of(Thread, _stack_size); }
 579 
 580 #define TLAB_FIELD_OFFSET(name) \
 581   static ByteSize tlab_##name##_offset()         { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::name##_offset(); }
 582 
 583   TLAB_FIELD_OFFSET(start)
 584   TLAB_FIELD_OFFSET(end)
 585   TLAB_FIELD_OFFSET(top)
 586   TLAB_FIELD_OFFSET(pf_top)
 587   TLAB_FIELD_OFFSET(size)                   // desired_size
 588   TLAB_FIELD_OFFSET(refill_waste_limit)
 589   TLAB_FIELD_OFFSET(number_of_refills)
 590   TLAB_FIELD_OFFSET(fast_refill_waste)
 591   TLAB_FIELD_OFFSET(slow_allocations)
 592 
 593 #undef TLAB_FIELD_OFFSET
 594 
 595   static ByteSize allocated_bytes_offset()       { return byte_offset_of(Thread, _allocated_bytes); }
 596 
 597  public:
 598   volatile intptr_t _Stalled;
 599   volatile int _TypeTag;
 600   ParkEvent * _ParkEvent;                     // for synchronized()
 601   ParkEvent * _SleepEvent;                    // for Thread.sleep
 602   ParkEvent * _MutexEvent;                    // for native internal Mutex/Monitor
 603   ParkEvent * _MuxEvent;                      // for low-level muxAcquire-muxRelease
 604   int NativeSyncRecursion;                    // diagnostic
 605 
 606   volatile int _OnTrap;                       // Resume-at IP delta
 607   jint _hashStateW;                           // Marsaglia Shift-XOR thread-local RNG
 608   jint _hashStateX;                           // thread-specific hashCode generator state
 609   jint _hashStateY;
 610   jint _hashStateZ;
 611   void * _schedctl;
 612 
 613 
 614   volatile jint rng[4];                      // RNG for spin loop
 615 
 616   // Low-level leaf-lock primitives used to implement synchronization
 617   // and native monitor-mutex infrastructure.
 618   // Not for general synchronization use.
 619   static void SpinAcquire(volatile int * Lock, const char * Name);
 620   static void SpinRelease(volatile int * Lock);
 621   static void muxAcquire(volatile intptr_t * Lock, const char * Name);
 622   static void muxAcquireW(volatile intptr_t * Lock, ParkEvent * ev);
 623   static void muxRelease(volatile intptr_t * Lock);
 624 };
 625 
 626 // Inline implementation of Thread::current()
 627 // Thread::current is "hot" it's called > 128K times in the 1st 500 msecs of
 628 // startup.
 629 // ThreadLocalStorage::thread is warm -- it's called > 16K times in the same
 630 // period.   This is inlined in thread_<os_family>.inline.hpp.
 631 
 632 inline Thread* Thread::current() {
 633 #ifdef ASSERT
 634   // This function is very high traffic. Define PARANOID to enable expensive
 635   // asserts.
 636 #ifdef PARANOID
 637   // Signal handler should call ThreadLocalStorage::get_thread_slow()
 638   Thread* t = ThreadLocalStorage::get_thread_slow();
 639   assert(t != NULL && !t->is_inside_signal_handler(),
 640          "Don't use Thread::current() inside signal handler");
 641 #endif
 642 #endif
 643   Thread* thread = ThreadLocalStorage::thread();
 644   assert(thread != NULL, "just checking");
 645   return thread;
 646 }
 647 
 648 // Name support for threads.  non-JavaThread subclasses with multiple
 649 // uniquely named instances should derive from this.
 650 class NamedThread: public Thread {
 651   friend class VMStructs;
 652   enum {
 653     max_name_len = 64
 654   };
 655  private:
 656   char* _name;
 657   // log JavaThread being processed by oops_do
 658   JavaThread* _processed_thread;
 659 
 660  public:
 661   NamedThread();
 662   ~NamedThread();
 663   // May only be called once per thread.
 664   void set_name(const char* format, ...)  ATTRIBUTE_PRINTF(2, 3);
 665   void initialize_named_thread();
 666   virtual bool is_Named_thread() const { return true; }
 667   virtual char* name() const { return _name == NULL ? (char*)"Unknown Thread" : _name; }
 668   JavaThread *processed_thread() { return _processed_thread; }
 669   void set_processed_thread(JavaThread *thread) { _processed_thread = thread; }
 670   virtual void print_on(outputStream* st) const;
 671 };
 672 
 673 // Worker threads are named and have an id of an assigned work.
 674 class WorkerThread: public NamedThread {
 675  private:
 676   uint _id;
 677  public:
 678   WorkerThread() : _id(0)               { }
 679   virtual bool is_Worker_thread() const { return true; }
 680 
 681   virtual WorkerThread* as_Worker_thread() const {
 682     assert(is_Worker_thread(), "Dubious cast to WorkerThread*?");
 683     return (WorkerThread*) this;
 684   }
 685 
 686   void set_id(uint work_id)             { _id = work_id; }
 687   uint id() const                       { return _id; }
 688 };
 689 
 690 // A single WatcherThread is used for simulating timer interrupts.
 691 class WatcherThread: public Thread {
 692   friend class VMStructs;
 693  public:
 694   virtual void run();
 695 
 696  private:
 697   static WatcherThread* _watcher_thread;
 698 
 699   static bool _startable;
 700   // volatile due to at least one lock-free read
 701   volatile static bool _should_terminate;
 702 
 703   os::WatcherThreadCrashProtection* _crash_protection;
 704  public:
 705   enum SomeConstants {
 706     delay_interval = 10                          // interrupt delay in milliseconds
 707   };
 708 
 709   // Constructor
 710   WatcherThread();
 711 
 712   // Tester
 713   bool is_Watcher_thread() const                 { return true; }
 714 
 715   // Printing
 716   char* name() const { return (char*)"VM Periodic Task Thread"; }
 717   void print_on(outputStream* st) const;
 718   void unpark();
 719 
 720   // Returns the single instance of WatcherThread
 721   static WatcherThread* watcher_thread()         { return _watcher_thread; }
 722 
 723   // Create and start the single instance of WatcherThread, or stop it on shutdown
 724   static void start();
 725   static void stop();
 726   // Only allow start once the VM is sufficiently initialized
 727   // Otherwise the first task to enroll will trigger the start
 728   static void make_startable();
 729 
 730   void set_crash_protection(os::WatcherThreadCrashProtection* crash_protection) {
 731     assert(Thread::current()->is_Watcher_thread(), "Can only be set by WatcherThread");
 732     _crash_protection = crash_protection;
 733   }
 734 
 735   bool has_crash_protection() const { return _crash_protection != NULL; }
 736   os::WatcherThreadCrashProtection* crash_protection() const { return _crash_protection; }
 737 
 738  private:
 739   int sleep() const;
 740 };
 741 
 742 
 743 class CompilerThread;
 744 
 745 typedef void (*ThreadFunction)(JavaThread*, TRAPS);
 746 
 747 class JavaThread: public Thread {
 748   friend class VMStructs;
 749   friend class WhiteBox;
 750  private:
 751   JavaThread*    _next;                          // The next thread in the Threads list
 752   oop            _threadObj;                     // The Java level thread object
 753 
 754 #ifdef ASSERT
 755  private:
 756   int _java_call_counter;
 757 
 758  public:
 759   int  java_call_counter()                       { return _java_call_counter; }
 760   void inc_java_call_counter()                   { _java_call_counter++; }
 761   void dec_java_call_counter() {
 762     assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
 763     _java_call_counter--;
 764   }
 765  private:  // restore original namespace restriction
 766 #endif  // ifdef ASSERT
 767 
 768 #ifndef PRODUCT
 769  public:
 770   enum {
 771     jump_ring_buffer_size = 16
 772   };
 773  private:  // restore original namespace restriction
 774 #endif
 775 
 776   JavaFrameAnchor _anchor;                       // Encapsulation of current java frame and it state
 777 
 778   ThreadFunction _entry_point;
 779 
 780   JNIEnv        _jni_environment;
 781 
 782   // Deopt support
 783   DeoptResourceMark*  _deopt_mark;               // Holds special ResourceMark for deoptimization
 784 
 785   intptr_t*      _must_deopt_id;                 // id of frame that needs to be deopted once we
 786                                                  // transition out of native
 787   nmethod*       _deopt_nmethod;                 // nmethod that is currently being deoptimized
 788   vframeArray*  _vframe_array_head;              // Holds the heap of the active vframeArrays
 789   vframeArray*  _vframe_array_last;              // Holds last vFrameArray we popped
 790   // Because deoptimization is lazy we must save jvmti requests to set locals
 791   // in compiled frames until we deoptimize and we have an interpreter frame.
 792   // This holds the pointer to array (yeah like there might be more than one) of
 793   // description of compiled vframes that have locals that need to be updated.
 794   GrowableArray<jvmtiDeferredLocalVariableSet*>* _deferred_locals_updates;
 795 
 796   // Handshake value for fixing 6243940. We need a place for the i2c
 797   // adapter to store the callee Method*. This value is NEVER live
 798   // across a gc point so it does NOT have to be gc'd
 799   // The handshake is open ended since we can't be certain that it will
 800   // be NULLed. This is because we rarely ever see the race and end up
 801   // in handle_wrong_method which is the backend of the handshake. See
 802   // code in i2c adapters and handle_wrong_method.
 803 
 804   Method*       _callee_target;
 805 
 806   // Used to pass back results to the interpreter or generated code running Java code.
 807   oop           _vm_result;    // oop result is GC-preserved
 808   Metadata*     _vm_result_2;  // non-oop result
 809 
 810   // See ReduceInitialCardMarks: this holds the precise space interval of
 811   // the most recent slow path allocation for which compiled code has
 812   // elided card-marks for performance along the fast-path.
 813   MemRegion     _deferred_card_mark;
 814 
 815   MonitorChunk* _monitor_chunks;                 // Contains the off stack monitors
 816                                                  // allocated during deoptimization
 817                                                  // and by JNI_MonitorEnter/Exit
 818 
 819   // Async. requests support
 820   enum AsyncRequests {
 821     _no_async_condition = 0,
 822     _async_exception,
 823     _async_unsafe_access_error
 824   };
 825   AsyncRequests _special_runtime_exit_condition; // Enum indicating pending async. request
 826   oop           _pending_async_exception;
 827 
 828   // Safepoint support
 829  public:                                         // Expose _thread_state for SafeFetchInt()
 830   volatile JavaThreadState _thread_state;
 831  private:
 832   ThreadSafepointState *_safepoint_state;        // Holds information about a thread during a safepoint
 833   address               _saved_exception_pc;     // Saved pc of instruction where last implicit exception happened
 834 
 835   // JavaThread termination support
 836   enum TerminatedTypes {
 837     _not_terminated = 0xDEAD - 2,
 838     _thread_exiting,                             // JavaThread::exit() has been called for this thread
 839     _thread_terminated,                          // JavaThread is removed from thread list
 840     _vm_exited                                   // JavaThread is still executing native code, but VM is terminated
 841                                                  // only VM_Exit can set _vm_exited
 842   };
 843 
 844   // In general a JavaThread's _terminated field transitions as follows:
 845   //
 846   //   _not_terminated => _thread_exiting => _thread_terminated
 847   //
 848   // _vm_exited is a special value to cover the case of a JavaThread
 849   // executing native code after the VM itself is terminated.
 850   volatile TerminatedTypes _terminated;
 851   // suspend/resume support
 852   volatile bool         _suspend_equivalent;     // Suspend equivalent condition
 853   jint                  _in_deopt_handler;       // count of deoptimization
 854                                                  // handlers thread is in
 855   volatile bool         _doing_unsafe_access;    // Thread may fault due to unsafe access
 856   bool                  _do_not_unlock_if_synchronized;  // Do not unlock the receiver of a synchronized method (since it was
 857                                                          // never locked) when throwing an exception. Used by interpreter only.
 858 
 859   // JNI attach states:
 860   enum JNIAttachStates {
 861     _not_attaching_via_jni = 1,  // thread is not attaching via JNI
 862     _attaching_via_jni,          // thread is attaching via JNI
 863     _attached_via_jni            // thread has attached via JNI
 864   };
 865 
 866   // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
 867   // A native thread that is attaching via JNI starts with a value
 868   // of _attaching_via_jni and transitions to _attached_via_jni.
 869   volatile JNIAttachStates _jni_attach_state;
 870 
 871  public:
 872   // State of the stack guard pages for this thread.
 873   enum StackGuardState {
 874     stack_guard_unused,         // not needed
 875     stack_guard_yellow_disabled,// disabled (temporarily) after stack overflow
 876     stack_guard_enabled         // enabled
 877   };
 878 
 879  private:
 880 
 881   StackGuardState  _stack_guard_state;
 882 
 883   // Precompute the limit of the stack as used in stack overflow checks.
 884   // We load it from here to simplify the stack overflow check in assembly.
 885   address          _stack_overflow_limit;
 886 
 887   // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
 888   // used to temp. parsing values into and out of the runtime system during exception handling for compiled
 889   // code)
 890   volatile oop     _exception_oop;               // Exception thrown in compiled code
 891   volatile address _exception_pc;                // PC where exception happened
 892   volatile address _exception_handler_pc;        // PC for handler of exception
 893   volatile int     _is_method_handle_return;     // true (== 1) if the current exception PC is a MethodHandle call site.
 894 
 895   // support for JNI critical regions
 896   jint    _jni_active_critical;                  // count of entries into JNI critical region
 897 
 898   // Checked JNI: function name requires exception check
 899   char* _pending_jni_exception_check_fn;
 900 
 901   // For deadlock detection.
 902   int _depth_first_number;
 903 
 904   // JVMTI PopFrame support
 905   // This is set to popframe_pending to signal that top Java frame should be popped immediately
 906   int _popframe_condition;
 907 
 908   // If reallocation of scalar replaced objects fails, we throw OOM
 909   // and during exception propagation, pop the top
 910   // _frames_to_pop_failed_realloc frames, the ones that reference
 911   // failed reallocations.
 912   int _frames_to_pop_failed_realloc;
 913 
 914 #ifndef PRODUCT
 915   int _jmp_ring_index;
 916   struct {
 917     // We use intptr_t instead of address so debugger doesn't try and display strings
 918     intptr_t _target;
 919     intptr_t _instruction;
 920     const char*  _file;
 921     int _line;
 922   }   _jmp_ring[jump_ring_buffer_size];
 923 #endif // PRODUCT
 924 
 925 #if INCLUDE_ALL_GCS
 926   // Support for G1 barriers
 927 
 928   ObjPtrQueue _satb_mark_queue;          // Thread-local log for SATB barrier.
 929   // Set of all such queues.
 930   static SATBMarkQueueSet _satb_mark_queue_set;
 931 
 932   DirtyCardQueue _dirty_card_queue;      // Thread-local log for dirty cards.
 933   // Set of all such queues.
 934   static DirtyCardQueueSet _dirty_card_queue_set;
 935 
 936   void flush_barrier_queues();
 937 #endif // INCLUDE_ALL_GCS
 938 
 939   friend class VMThread;
 940   friend class ThreadWaitTransition;
 941   friend class VM_Exit;
 942 
 943   void initialize();                             // Initialized the instance variables
 944 
 945  public:
 946   // Constructor
 947   JavaThread(bool is_attaching_via_jni = false); // for main thread and JNI attached threads
 948   JavaThread(ThreadFunction entry_point, size_t stack_size = 0);
 949   ~JavaThread();
 950 
 951 #ifdef ASSERT
 952   // verify this JavaThread hasn't be published in the Threads::list yet
 953   void verify_not_published();
 954 #endif
 955 
 956   //JNI functiontable getter/setter for JVMTI jni function table interception API.
 957   void set_jni_functions(struct JNINativeInterface_* functionTable) {
 958     _jni_environment.functions = functionTable;
 959   }
 960   struct JNINativeInterface_* get_jni_functions() {
 961     return (struct JNINativeInterface_ *)_jni_environment.functions;
 962   }
 963 
 964   // This function is called at thread creation to allow
 965   // platform specific thread variables to be initialized.
 966   void cache_global_variables();
 967 
 968   // Executes Shutdown.shutdown()
 969   void invoke_shutdown_hooks();
 970 
 971   // Cleanup on thread exit
 972   enum ExitType {
 973     normal_exit,
 974     jni_detach
 975   };
 976   void exit(bool destroy_vm, ExitType exit_type = normal_exit);
 977 
 978   void cleanup_failed_attach_current_thread();
 979 
 980   // Testers
 981   virtual bool is_Java_thread() const            { return true;  }
 982 
 983   // Thread chain operations
 984   JavaThread* next() const                       { return _next; }
 985   void set_next(JavaThread* p)                   { _next = p; }
 986 
 987   // Thread oop. threadObj() can be NULL for initial JavaThread
 988   // (or for threads attached via JNI)
 989   oop threadObj() const                          { return _threadObj; }
 990   void set_threadObj(oop p)                      { _threadObj = p; }
 991 
 992   ThreadPriority java_priority() const;          // Read from threadObj()
 993 
 994   // Prepare thread and add to priority queue.  If a priority is
 995   // not specified, use the priority of the thread object. Threads_lock
 996   // must be held while this function is called.
 997   void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
 998   void prepare_ext();
 999 
1000   void set_saved_exception_pc(address pc)        { _saved_exception_pc = pc; }
1001   address saved_exception_pc()                   { return _saved_exception_pc; }
1002 
1003 
1004   ThreadFunction entry_point() const             { return _entry_point; }
1005 
1006   // Allocates a new Java level thread object for this thread. thread_name may be NULL.
1007   void allocate_threadObj(Handle thread_group, const char* thread_name, bool daemon, TRAPS);
1008 
1009   // Last frame anchor routines
1010 
1011   JavaFrameAnchor* frame_anchor(void)            { return &_anchor; }
1012 
1013   // last_Java_sp
1014   bool has_last_Java_frame() const               { return _anchor.has_last_Java_frame(); }
1015   intptr_t* last_Java_sp() const                 { return _anchor.last_Java_sp(); }
1016 
1017   // last_Java_pc
1018 
1019   address last_Java_pc(void)                     { return _anchor.last_Java_pc(); }
1020 
1021   // Safepoint support
1022 #if !(defined(PPC64) || defined(AARCH64))
1023   JavaThreadState thread_state() const           { return _thread_state; }
1024   void set_thread_state(JavaThreadState s)       { _thread_state = s;    }
1025 #else
1026   // Use membars when accessing volatile _thread_state. See
1027   // Threads::create_vm() for size checks.
1028   inline JavaThreadState thread_state() const;
1029   inline void set_thread_state(JavaThreadState s);
1030 #endif
1031   ThreadSafepointState *safepoint_state() const  { return _safepoint_state; }
1032   void set_safepoint_state(ThreadSafepointState *state) { _safepoint_state = state; }
1033   bool is_at_poll_safepoint()                    { return _safepoint_state->is_at_poll_safepoint(); }
1034 
1035   // thread has called JavaThread::exit() or is terminated
1036   bool is_exiting()                              { return _terminated == _thread_exiting || is_terminated(); }
1037   // thread is terminated (no longer on the threads list); we compare
1038   // against the two non-terminated values so that a freed JavaThread
1039   // will also be considered terminated.
1040   bool is_terminated()                           { return _terminated != _not_terminated && _terminated != _thread_exiting; }
1041   void set_terminated(TerminatedTypes t)         { _terminated = t; }
1042   // special for Threads::remove() which is static:
1043   void set_terminated_value()                    { _terminated = _thread_terminated; }
1044   void block_if_vm_exited();
1045 
1046   bool doing_unsafe_access()                     { return _doing_unsafe_access; }
1047   void set_doing_unsafe_access(bool val)         { _doing_unsafe_access = val; }
1048 
1049   bool do_not_unlock_if_synchronized()             { return _do_not_unlock_if_synchronized; }
1050   void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
1051 
1052   // Suspend/resume support for JavaThread
1053  private:
1054   inline void set_ext_suspended();
1055   inline void clear_ext_suspended();
1056 
1057  public:
1058   void java_suspend();
1059   void java_resume();
1060   int  java_suspend_self();
1061 
1062   void check_and_wait_while_suspended() {
1063     assert(JavaThread::current() == this, "sanity check");
1064 
1065     bool do_self_suspend;
1066     do {
1067       // were we externally suspended while we were waiting?
1068       do_self_suspend = handle_special_suspend_equivalent_condition();
1069       if (do_self_suspend) {
1070         // don't surprise the thread that suspended us by returning
1071         java_suspend_self();
1072         set_suspend_equivalent();
1073       }
1074     } while (do_self_suspend);
1075   }
1076   static void check_safepoint_and_suspend_for_native_trans(JavaThread *thread);
1077   // Check for async exception in addition to safepoint and suspend request.
1078   static void check_special_condition_for_native_trans(JavaThread *thread);
1079 
1080   // Same as check_special_condition_for_native_trans but finishes the
1081   // transition into thread_in_Java mode so that it can potentially
1082   // block.
1083   static void check_special_condition_for_native_trans_and_transition(JavaThread *thread);
1084 
1085   bool is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits);
1086   bool is_ext_suspend_completed_with_lock(uint32_t *bits) {
1087     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1088     // Warning: is_ext_suspend_completed() may temporarily drop the
1089     // SR_lock to allow the thread to reach a stable thread state if
1090     // it is currently in a transient thread state.
1091     return is_ext_suspend_completed(false /* !called_by_wait */,
1092                                     SuspendRetryDelay, bits);
1093   }
1094 
1095   // We cannot allow wait_for_ext_suspend_completion() to run forever or
1096   // we could hang. SuspendRetryCount and SuspendRetryDelay are normally
1097   // passed as the count and delay parameters. Experiments with specific
1098   // calls to wait_for_ext_suspend_completion() can be done by passing
1099   // other values in the code. Experiments with all calls can be done
1100   // via the appropriate -XX options.
1101   bool wait_for_ext_suspend_completion(int count, int delay, uint32_t *bits);
1102 
1103   inline void set_external_suspend();
1104   inline void clear_external_suspend();
1105 
1106   inline void set_deopt_suspend();
1107   inline void clear_deopt_suspend();
1108   bool is_deopt_suspend()         { return (_suspend_flags & _deopt_suspend) != 0; }
1109 
1110   bool is_external_suspend() const {
1111     return (_suspend_flags & _external_suspend) != 0;
1112   }
1113   // Whenever a thread transitions from native to vm/java it must suspend
1114   // if external|deopt suspend is present.
1115   bool is_suspend_after_native() const {
1116     return (_suspend_flags & (_external_suspend | _deopt_suspend)) != 0;
1117   }
1118 
1119   // external suspend request is completed
1120   bool is_ext_suspended() const {
1121     return (_suspend_flags & _ext_suspended) != 0;
1122   }
1123 
1124   bool is_external_suspend_with_lock() const {
1125     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1126     return is_external_suspend();
1127   }
1128 
1129   // Special method to handle a pending external suspend request
1130   // when a suspend equivalent condition lifts.
1131   bool handle_special_suspend_equivalent_condition() {
1132     assert(is_suspend_equivalent(),
1133            "should only be called in a suspend equivalence condition");
1134     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1135     bool ret = is_external_suspend();
1136     if (!ret) {
1137       // not about to self-suspend so clear suspend equivalence
1138       clear_suspend_equivalent();
1139     }
1140     // implied else:
1141     // We have a pending external suspend request so we leave the
1142     // suspend_equivalent flag set until java_suspend_self() sets
1143     // the ext_suspended flag and clears the suspend_equivalent
1144     // flag. This insures that wait_for_ext_suspend_completion()
1145     // will return consistent values.
1146     return ret;
1147   }
1148 
1149   // utility methods to see if we are doing some kind of suspension
1150   bool is_being_ext_suspended() const            {
1151     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1152     return is_ext_suspended() || is_external_suspend();
1153   }
1154 
1155   bool is_suspend_equivalent() const             { return _suspend_equivalent; }
1156 
1157   void set_suspend_equivalent()                  { _suspend_equivalent = true; }
1158   void clear_suspend_equivalent()                { _suspend_equivalent = false; }
1159 
1160   // Thread.stop support
1161   void send_thread_stop(oop throwable);
1162   AsyncRequests clear_special_runtime_exit_condition() {
1163     AsyncRequests x = _special_runtime_exit_condition;
1164     _special_runtime_exit_condition = _no_async_condition;
1165     return x;
1166   }
1167 
1168   // Are any async conditions present?
1169   bool has_async_condition() { return (_special_runtime_exit_condition != _no_async_condition); }
1170 
1171   void check_and_handle_async_exceptions(bool check_unsafe_error = true);
1172 
1173   // these next two are also used for self-suspension and async exception support
1174   void handle_special_runtime_exit_condition(bool check_asyncs = true);
1175 
1176   // Return true if JavaThread has an asynchronous condition or
1177   // if external suspension is requested.
1178   bool has_special_runtime_exit_condition() {
1179     // We call is_external_suspend() last since external suspend should
1180     // be less common. Because we don't use is_external_suspend_with_lock
1181     // it is possible that we won't see an asynchronous external suspend
1182     // request that has just gotten started, i.e., SR_lock grabbed but
1183     // _external_suspend field change either not made yet or not visible
1184     // yet. However, this is okay because the request is asynchronous and
1185     // we will see the new flag value the next time through. It's also
1186     // possible that the external suspend request is dropped after
1187     // we have checked is_external_suspend(), we will recheck its value
1188     // under SR_lock in java_suspend_self().
1189     return (_special_runtime_exit_condition != _no_async_condition) ||
1190             is_external_suspend() || is_deopt_suspend();
1191   }
1192 
1193   void set_pending_unsafe_access_error()          { _special_runtime_exit_condition = _async_unsafe_access_error; }
1194 
1195   inline void set_pending_async_exception(oop e);
1196 
1197   // Fast-locking support
1198   bool is_lock_owned(address adr) const;
1199 
1200   // Accessors for vframe array top
1201   // The linked list of vframe arrays are sorted on sp. This means when we
1202   // unpack the head must contain the vframe array to unpack.
1203   void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
1204   vframeArray* vframe_array_head() const         { return _vframe_array_head;  }
1205 
1206   // Side structure for deferring update of java frame locals until deopt occurs
1207   GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred_locals() const { return _deferred_locals_updates; }
1208   void set_deferred_locals(GrowableArray<jvmtiDeferredLocalVariableSet *>* vf) { _deferred_locals_updates = vf; }
1209 
1210   // These only really exist to make debugging deopt problems simpler
1211 
1212   void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
1213   vframeArray* vframe_array_last() const         { return _vframe_array_last;  }
1214 
1215   // The special resourceMark used during deoptimization
1216 
1217   void set_deopt_mark(DeoptResourceMark* value)  { _deopt_mark = value; }
1218   DeoptResourceMark* deopt_mark(void)            { return _deopt_mark; }
1219 
1220   intptr_t* must_deopt_id()                      { return _must_deopt_id; }
1221   void     set_must_deopt_id(intptr_t* id)       { _must_deopt_id = id; }
1222   void     clear_must_deopt_id()                 { _must_deopt_id = NULL; }
1223 
1224   void set_deopt_nmethod(nmethod* nm)            { _deopt_nmethod = nm;   }
1225   nmethod* deopt_nmethod()                       { return _deopt_nmethod; }
1226 
1227   Method*    callee_target() const               { return _callee_target; }
1228   void set_callee_target  (Method* x)          { _callee_target   = x; }
1229 
1230   // Oop results of vm runtime calls
1231   oop  vm_result() const                         { return _vm_result; }
1232   void set_vm_result  (oop x)                    { _vm_result   = x; }
1233 
1234   Metadata*    vm_result_2() const               { return _vm_result_2; }
1235   void set_vm_result_2  (Metadata* x)          { _vm_result_2   = x; }
1236 
1237   MemRegion deferred_card_mark() const           { return _deferred_card_mark; }
1238   void set_deferred_card_mark(MemRegion mr)      { _deferred_card_mark = mr;   }
1239 
1240   // Exception handling for compiled methods
1241   oop      exception_oop() const                 { return _exception_oop; }
1242   address  exception_pc() const                  { return _exception_pc; }
1243   address  exception_handler_pc() const          { return _exception_handler_pc; }
1244   bool     is_method_handle_return() const       { return _is_method_handle_return == 1; }
1245 
1246   void set_exception_oop(oop o)                  { (void)const_cast<oop&>(_exception_oop = o); }
1247   void set_exception_pc(address a)               { _exception_pc = a; }
1248   void set_exception_handler_pc(address a)       { _exception_handler_pc = a; }
1249   void set_is_method_handle_return(bool value)   { _is_method_handle_return = value ? 1 : 0; }
1250 
1251   void clear_exception_oop_and_pc() {
1252     set_exception_oop(NULL);
1253     set_exception_pc(NULL);
1254   }
1255 
1256   // Stack overflow support
1257   inline size_t stack_available(address cur_sp);
1258   address stack_yellow_zone_base() {
1259     return (address)(stack_base() -
1260                      (stack_size() -
1261                      (stack_red_zone_size() + stack_yellow_zone_size())));
1262   }
1263   size_t  stack_yellow_zone_size() {
1264     return StackYellowPages * os::vm_page_size();
1265   }
1266   address stack_red_zone_base() {
1267     return (address)(stack_base() - (stack_size() - stack_red_zone_size()));
1268   }
1269   size_t stack_red_zone_size() { return StackRedPages * os::vm_page_size(); }
1270   bool in_stack_yellow_zone(address a) {
1271     return (a <= stack_yellow_zone_base()) && (a >= stack_red_zone_base());
1272   }
1273   bool in_stack_red_zone(address a) {
1274     return (a <= stack_red_zone_base()) &&
1275            (a >= (address)((intptr_t)stack_base() - stack_size()));
1276   }
1277 
1278   void create_stack_guard_pages();
1279   void remove_stack_guard_pages();
1280 
1281   void enable_stack_yellow_zone();
1282   void disable_stack_yellow_zone();
1283   void enable_stack_red_zone();
1284   void disable_stack_red_zone();
1285 
1286   inline bool stack_guard_zone_unused();
1287   inline bool stack_yellow_zone_disabled();
1288   inline bool stack_yellow_zone_enabled();
1289 
1290   // Attempt to reguard the stack after a stack overflow may have occurred.
1291   // Returns true if (a) guard pages are not needed on this thread, (b) the
1292   // pages are already guarded, or (c) the pages were successfully reguarded.
1293   // Returns false if there is not enough stack space to reguard the pages, in
1294   // which case the caller should unwind a frame and try again.  The argument
1295   // should be the caller's (approximate) sp.
1296   bool reguard_stack(address cur_sp);
1297   // Similar to above but see if current stackpoint is out of the guard area
1298   // and reguard if possible.
1299   bool reguard_stack(void);
1300 
1301   address stack_overflow_limit() { return _stack_overflow_limit; }
1302   void set_stack_overflow_limit() {
1303     _stack_overflow_limit = _stack_base - _stack_size +
1304                             ((StackShadowPages +
1305                               StackYellowPages +
1306                               StackRedPages) * os::vm_page_size());
1307   }
1308 
1309   // Misc. accessors/mutators
1310   void set_do_not_unlock(void)                   { _do_not_unlock_if_synchronized = true; }
1311   void clr_do_not_unlock(void)                   { _do_not_unlock_if_synchronized = false; }
1312   bool do_not_unlock(void)                       { return _do_not_unlock_if_synchronized; }
1313 
1314 #ifndef PRODUCT
1315   void record_jump(address target, address instr, const char* file, int line);
1316 #endif // PRODUCT
1317 
1318   // For assembly stub generation
1319   static ByteSize threadObj_offset()             { return byte_offset_of(JavaThread, _threadObj); }
1320 #ifndef PRODUCT
1321   static ByteSize jmp_ring_index_offset()        { return byte_offset_of(JavaThread, _jmp_ring_index); }
1322   static ByteSize jmp_ring_offset()              { return byte_offset_of(JavaThread, _jmp_ring); }
1323 #endif // PRODUCT
1324   static ByteSize jni_environment_offset()       { return byte_offset_of(JavaThread, _jni_environment); }
1325   static ByteSize last_Java_sp_offset() {
1326     return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
1327   }
1328   static ByteSize last_Java_pc_offset() {
1329     return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
1330   }
1331   static ByteSize frame_anchor_offset() {
1332     return byte_offset_of(JavaThread, _anchor);
1333   }
1334   static ByteSize callee_target_offset()         { return byte_offset_of(JavaThread, _callee_target); }
1335   static ByteSize vm_result_offset()             { return byte_offset_of(JavaThread, _vm_result); }
1336   static ByteSize vm_result_2_offset()           { return byte_offset_of(JavaThread, _vm_result_2); }
1337   static ByteSize thread_state_offset()          { return byte_offset_of(JavaThread, _thread_state); }
1338   static ByteSize saved_exception_pc_offset()    { return byte_offset_of(JavaThread, _saved_exception_pc); }
1339   static ByteSize osthread_offset()              { return byte_offset_of(JavaThread, _osthread); }
1340   static ByteSize exception_oop_offset()         { return byte_offset_of(JavaThread, _exception_oop); }
1341   static ByteSize exception_pc_offset()          { return byte_offset_of(JavaThread, _exception_pc); }
1342   static ByteSize exception_handler_pc_offset()  { return byte_offset_of(JavaThread, _exception_handler_pc); }
1343   static ByteSize stack_overflow_limit_offset()  { return byte_offset_of(JavaThread, _stack_overflow_limit); }
1344   static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); }
1345   static ByteSize stack_guard_state_offset()     { return byte_offset_of(JavaThread, _stack_guard_state); }
1346   static ByteSize suspend_flags_offset()         { return byte_offset_of(JavaThread, _suspend_flags); }
1347 
1348   static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
1349   static ByteSize should_post_on_exceptions_flag_offset() {
1350     return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
1351   }
1352 
1353 #if INCLUDE_ALL_GCS
1354   static ByteSize satb_mark_queue_offset()       { return byte_offset_of(JavaThread, _satb_mark_queue); }
1355   static ByteSize dirty_card_queue_offset()      { return byte_offset_of(JavaThread, _dirty_card_queue); }
1356 #endif // INCLUDE_ALL_GCS
1357 
1358   // Returns the jni environment for this thread
1359   JNIEnv* jni_environment()                      { return &_jni_environment; }
1360 
1361   static JavaThread* thread_from_jni_environment(JNIEnv* env) {
1362     JavaThread *thread_from_jni_env = (JavaThread*)((intptr_t)env - in_bytes(jni_environment_offset()));
1363     // Only return NULL if thread is off the thread list; starting to
1364     // exit should not return NULL.
1365     if (thread_from_jni_env->is_terminated()) {
1366       thread_from_jni_env->block_if_vm_exited();
1367       return NULL;
1368     } else {
1369       return thread_from_jni_env;
1370     }
1371   }
1372 
1373   // JNI critical regions. These can nest.
1374   bool in_critical()    { return _jni_active_critical > 0; }
1375   bool in_last_critical()  { return _jni_active_critical == 1; }
1376   void enter_critical() {
1377     assert(Thread::current() == this ||
1378            (Thread::current()->is_VM_thread() &&
1379            SafepointSynchronize::is_synchronizing()),
1380            "this must be current thread or synchronizing");
1381     _jni_active_critical++;
1382   }
1383   void exit_critical() {
1384     assert(Thread::current() == this, "this must be current thread");
1385     _jni_active_critical--;
1386     assert(_jni_active_critical >= 0, "JNI critical nesting problem?");
1387   }
1388 
1389   // Checked JNI, is the programmer required to check for exceptions, specify which function name
1390   bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != NULL; }
1391   void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = NULL; }
1392   const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; }
1393   void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; }
1394 
1395   // For deadlock detection
1396   int depth_first_number() { return _depth_first_number; }
1397   void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
1398 
1399  private:
1400   void set_monitor_chunks(MonitorChunk* monitor_chunks) { _monitor_chunks = monitor_chunks; }
1401 
1402  public:
1403   MonitorChunk* monitor_chunks() const           { return _monitor_chunks; }
1404   void add_monitor_chunk(MonitorChunk* chunk);
1405   void remove_monitor_chunk(MonitorChunk* chunk);
1406   bool in_deopt_handler() const                  { return _in_deopt_handler > 0; }
1407   void inc_in_deopt_handler()                    { _in_deopt_handler++; }
1408   void dec_in_deopt_handler() {
1409     assert(_in_deopt_handler > 0, "mismatched deopt nesting");
1410     if (_in_deopt_handler > 0) { // robustness
1411       _in_deopt_handler--;
1412     }
1413   }
1414 
1415  private:
1416   void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
1417 
1418  public:
1419 
1420   // Frame iteration; calls the function f for all frames on the stack
1421   void frames_do(void f(frame*, const RegisterMap*));
1422 
1423   // Memory operations
1424   void oops_do(OopClosure* f, CLDClosure* cld_f, CodeBlobClosure* cf);
1425 
1426   // Sweeper operations
1427   void nmethods_do(CodeBlobClosure* cf);
1428 
1429   // RedefineClasses Support
1430   void metadata_do(void f(Metadata*));
1431 
1432   // Misc. operations
1433   char* name() const { return (char*)get_thread_name(); }
1434   void print_on(outputStream* st) const;
1435   void print_value();
1436   void print_thread_state_on(outputStream*) const      PRODUCT_RETURN;
1437   void print_thread_state() const                      PRODUCT_RETURN;
1438   void print_on_error(outputStream* st, char* buf, int buflen) const;
1439   void verify();
1440   const char* get_thread_name() const;
1441  private:
1442   // factor out low-level mechanics for use in both normal and error cases
1443   const char* get_thread_name_string(char* buf = NULL, int buflen = 0) const;
1444  public:
1445   const char* get_threadgroup_name() const;
1446   const char* get_parent_name() const;
1447 
1448   // Accessing frames
1449   frame last_frame() {
1450     _anchor.make_walkable(this);
1451     return pd_last_frame();
1452   }
1453   javaVFrame* last_java_vframe(RegisterMap* reg_map);
1454 
1455   // Returns method at 'depth' java or native frames down the stack
1456   // Used for security checks
1457   Klass* security_get_caller_class(int depth);
1458 
1459   // Print stack trace in external format
1460   void print_stack_on(outputStream* st);
1461   void print_stack() { print_stack_on(tty); }
1462 
1463   // Print stack traces in various internal formats
1464   void trace_stack()                             PRODUCT_RETURN;
1465   void trace_stack_from(vframe* start_vf)        PRODUCT_RETURN;
1466   void trace_frames()                            PRODUCT_RETURN;
1467   void trace_oops()                              PRODUCT_RETURN;
1468 
1469   // Print an annotated view of the stack frames
1470   void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN;
1471   void validate_frame_layout() {
1472     print_frame_layout(0, true);
1473   }
1474 
1475   // Returns the number of stack frames on the stack
1476   int depth() const;
1477 
1478   // Function for testing deoptimization
1479   void deoptimize();
1480   void make_zombies();
1481 
1482   void deoptimized_wrt_marked_nmethods();
1483 
1484   // Profiling operation (see fprofile.cpp)
1485  public:
1486   bool profile_last_Java_frame(frame* fr);
1487 
1488  private:
1489   ThreadProfiler* _thread_profiler;
1490  private:
1491   friend class FlatProfiler;                    // uses both [gs]et_thread_profiler.
1492   friend class FlatProfilerTask;                // uses get_thread_profiler.
1493   friend class ThreadProfilerMark;              // uses get_thread_profiler.
1494   ThreadProfiler* get_thread_profiler()         { return _thread_profiler; }
1495   ThreadProfiler* set_thread_profiler(ThreadProfiler* tp) {
1496     ThreadProfiler* result = _thread_profiler;
1497     _thread_profiler = tp;
1498     return result;
1499   }
1500 
1501  public:
1502   // Returns the running thread as a JavaThread
1503   static inline JavaThread* current();
1504 
1505   // Returns the active Java thread.  Do not use this if you know you are calling
1506   // from a JavaThread, as it's slower than JavaThread::current.  If called from
1507   // the VMThread, it also returns the JavaThread that instigated the VMThread's
1508   // operation.  You may not want that either.
1509   static JavaThread* active();
1510 
1511   inline CompilerThread* as_CompilerThread();
1512 
1513  public:
1514   virtual void run();
1515   void thread_main_inner();
1516 
1517  private:
1518   // PRIVILEGED STACK
1519   PrivilegedElement*  _privileged_stack_top;
1520   GrowableArray<oop>* _array_for_gc;
1521  public:
1522 
1523   // Returns the privileged_stack information.
1524   PrivilegedElement* privileged_stack_top() const       { return _privileged_stack_top; }
1525   void set_privileged_stack_top(PrivilegedElement *e)   { _privileged_stack_top = e; }
1526   void register_array_for_gc(GrowableArray<oop>* array) { _array_for_gc = array; }
1527 
1528  public:
1529   // Thread local information maintained by JVMTI.
1530   void set_jvmti_thread_state(JvmtiThreadState *value)                           { _jvmti_thread_state = value; }
1531   // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1532   // getter is used to get this JavaThread's JvmtiThreadState if it has
1533   // one which means NULL can be returned. JvmtiThreadState::state_for()
1534   // is used to get the specified JavaThread's JvmtiThreadState if it has
1535   // one or it allocates a new JvmtiThreadState for the JavaThread and
1536   // returns it. JvmtiThreadState::state_for() will return NULL only if
1537   // the specified JavaThread is exiting.
1538   JvmtiThreadState *jvmti_thread_state() const                                   { return _jvmti_thread_state; }
1539   static ByteSize jvmti_thread_state_offset()                                    { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1540   void set_jvmti_get_loaded_classes_closure(JvmtiGetLoadedClassesClosure* value) { _jvmti_get_loaded_classes_closure = value; }
1541   JvmtiGetLoadedClassesClosure* get_jvmti_get_loaded_classes_closure() const     { return _jvmti_get_loaded_classes_closure; }
1542 
1543   // JVMTI PopFrame support
1544   // Setting and clearing popframe_condition
1545   // All of these enumerated values are bits. popframe_pending
1546   // indicates that a PopFrame() has been requested and not yet been
1547   // completed. popframe_processing indicates that that PopFrame() is in
1548   // the process of being completed. popframe_force_deopt_reexecution_bit
1549   // indicates that special handling is required when returning to a
1550   // deoptimized caller.
1551   enum PopCondition {
1552     popframe_inactive                      = 0x00,
1553     popframe_pending_bit                   = 0x01,
1554     popframe_processing_bit                = 0x02,
1555     popframe_force_deopt_reexecution_bit   = 0x04
1556   };
1557   PopCondition popframe_condition()                   { return (PopCondition) _popframe_condition; }
1558   void set_popframe_condition(PopCondition c)         { _popframe_condition = c; }
1559   void set_popframe_condition_bit(PopCondition c)     { _popframe_condition |= c; }
1560   void clear_popframe_condition()                     { _popframe_condition = popframe_inactive; }
1561   static ByteSize popframe_condition_offset()         { return byte_offset_of(JavaThread, _popframe_condition); }
1562   bool has_pending_popframe()                         { return (popframe_condition() & popframe_pending_bit) != 0; }
1563   bool popframe_forcing_deopt_reexecution()           { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
1564   void clear_popframe_forcing_deopt_reexecution()     { _popframe_condition &= ~popframe_force_deopt_reexecution_bit; }
1565 #ifdef CC_INTERP
1566   bool pop_frame_pending(void)                        { return ((_popframe_condition & popframe_pending_bit) != 0); }
1567   void clr_pop_frame_pending(void)                    { _popframe_condition = popframe_inactive; }
1568   bool pop_frame_in_process(void)                     { return ((_popframe_condition & popframe_processing_bit) != 0); }
1569   void set_pop_frame_in_process(void)                 { _popframe_condition |= popframe_processing_bit; }
1570   void clr_pop_frame_in_process(void)                 { _popframe_condition &= ~popframe_processing_bit; }
1571 #endif
1572 
1573   int frames_to_pop_failed_realloc() const            { return _frames_to_pop_failed_realloc; }
1574   void set_frames_to_pop_failed_realloc(int nb)       { _frames_to_pop_failed_realloc = nb; }
1575   void dec_frames_to_pop_failed_realloc()             { _frames_to_pop_failed_realloc--; }
1576 
1577  private:
1578   // Saved incoming arguments to popped frame.
1579   // Used only when popped interpreted frame returns to deoptimized frame.
1580   void*    _popframe_preserved_args;
1581   int      _popframe_preserved_args_size;
1582 
1583  public:
1584   void  popframe_preserve_args(ByteSize size_in_bytes, void* start);
1585   void* popframe_preserved_args();
1586   ByteSize popframe_preserved_args_size();
1587   WordSize popframe_preserved_args_size_in_words();
1588   void  popframe_free_preserved_args();
1589 
1590 
1591  private:
1592   JvmtiThreadState *_jvmti_thread_state;
1593   JvmtiGetLoadedClassesClosure* _jvmti_get_loaded_classes_closure;
1594 
1595   // Used by the interpreter in fullspeed mode for frame pop, method
1596   // entry, method exit and single stepping support. This field is
1597   // only set to non-zero by the VM_EnterInterpOnlyMode VM operation.
1598   // It can be set to zero asynchronously (i.e., without a VM operation
1599   // or a lock) so we have to be very careful.
1600   int               _interp_only_mode;
1601 
1602  public:
1603   // used by the interpreter for fullspeed debugging support (see above)
1604   static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
1605   bool is_interp_only_mode()                { return (_interp_only_mode != 0); }
1606   int get_interp_only_mode()                { return _interp_only_mode; }
1607   void increment_interp_only_mode()         { ++_interp_only_mode; }
1608   void decrement_interp_only_mode()         { --_interp_only_mode; }
1609 
1610   // support for cached flag that indicates whether exceptions need to be posted for this thread
1611   // if this is false, we can avoid deoptimizing when events are thrown
1612   // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
1613  private:
1614   int    _should_post_on_exceptions_flag;
1615 
1616  public:
1617   int   should_post_on_exceptions_flag()  { return _should_post_on_exceptions_flag; }
1618   void  set_should_post_on_exceptions_flag(int val)  { _should_post_on_exceptions_flag = val; }
1619 
1620  private:
1621   ThreadStatistics *_thread_stat;
1622 
1623  public:
1624   ThreadStatistics* get_thread_stat() const    { return _thread_stat; }
1625 
1626   // Return a blocker object for which this thread is blocked parking.
1627   oop current_park_blocker();
1628 
1629  private:
1630   static size_t _stack_size_at_create;
1631 
1632  public:
1633   static inline size_t stack_size_at_create(void) {
1634     return _stack_size_at_create;
1635   }
1636   static inline void set_stack_size_at_create(size_t value) {
1637     _stack_size_at_create = value;
1638   }
1639 
1640 #if INCLUDE_ALL_GCS
1641   // SATB marking queue support
1642   ObjPtrQueue& satb_mark_queue() { return _satb_mark_queue; }
1643   static SATBMarkQueueSet& satb_mark_queue_set() {
1644     return _satb_mark_queue_set;
1645   }
1646 
1647   // Dirty card queue support
1648   DirtyCardQueue& dirty_card_queue() { return _dirty_card_queue; }
1649   static DirtyCardQueueSet& dirty_card_queue_set() {
1650     return _dirty_card_queue_set;
1651   }
1652 #endif // INCLUDE_ALL_GCS
1653 
1654   // This method initializes the SATB and dirty card queues before a
1655   // JavaThread is added to the Java thread list. Right now, we don't
1656   // have to do anything to the dirty card queue (it should have been
1657   // activated when the thread was created), but we have to activate
1658   // the SATB queue if the thread is created while a marking cycle is
1659   // in progress. The activation / de-activation of the SATB queues at
1660   // the beginning / end of a marking cycle is done during safepoints
1661   // so we have to make sure this method is called outside one to be
1662   // able to safely read the active field of the SATB queue set. Right
1663   // now, it is called just before the thread is added to the Java
1664   // thread list in the Threads::add() method. That method is holding
1665   // the Threads_lock which ensures we are outside a safepoint. We
1666   // cannot do the obvious and set the active field of the SATB queue
1667   // when the thread is created given that, in some cases, safepoints
1668   // might happen between the JavaThread constructor being called and the
1669   // thread being added to the Java thread list (an example of this is
1670   // when the structure for the DestroyJavaVM thread is created).
1671 #if INCLUDE_ALL_GCS
1672   void initialize_queues();
1673 #else  // INCLUDE_ALL_GCS
1674   void initialize_queues() { }
1675 #endif // INCLUDE_ALL_GCS
1676 
1677   // Machine dependent stuff
1678 #ifdef TARGET_OS_ARCH_linux_x86
1679 # include "thread_linux_x86.hpp"
1680 #endif
1681 #ifdef TARGET_OS_ARCH_linux_sparc
1682 # include "thread_linux_sparc.hpp"
1683 #endif
1684 #ifdef TARGET_OS_ARCH_linux_zero
1685 # include "thread_linux_zero.hpp"
1686 #endif
1687 #ifdef TARGET_OS_ARCH_solaris_x86
1688 # include "thread_solaris_x86.hpp"
1689 #endif
1690 #ifdef TARGET_OS_ARCH_solaris_sparc
1691 # include "thread_solaris_sparc.hpp"
1692 #endif
1693 #ifdef TARGET_OS_ARCH_windows_x86
1694 # include "thread_windows_x86.hpp"
1695 #endif
1696 #ifdef TARGET_OS_ARCH_linux_arm
1697 # include "thread_linux_arm.hpp"
1698 #endif
1699 #ifdef TARGET_OS_ARCH_linux_ppc
1700 # include "thread_linux_ppc.hpp"
1701 #endif
1702 #ifdef TARGET_OS_ARCH_linux_aarch64
1703 # include "thread_linux_aarch64.hpp"
1704 #endif
1705 #ifdef TARGET_OS_ARCH_aix_ppc
1706 # include "thread_aix_ppc.hpp"
1707 #endif
1708 #ifdef TARGET_OS_ARCH_bsd_x86
1709 # include "thread_bsd_x86.hpp"
1710 #endif
1711 #ifdef TARGET_OS_ARCH_bsd_zero
1712 # include "thread_bsd_zero.hpp"
1713 #endif
1714 
1715 
1716  public:
1717   void set_blocked_on_compilation(bool value) {
1718     _blocked_on_compilation = value;
1719   }
1720 
1721   bool blocked_on_compilation() {
1722     return _blocked_on_compilation;
1723   }
1724  protected:
1725   bool         _blocked_on_compilation;
1726 
1727 
1728   // JSR166 per-thread parker
1729  private:
1730   Parker*    _parker;
1731  public:
1732   Parker*     parker() { return _parker; }
1733 
1734   // Biased locking support
1735  private:
1736   GrowableArray<MonitorInfo*>* _cached_monitor_info;
1737  public:
1738   GrowableArray<MonitorInfo*>* cached_monitor_info() { return _cached_monitor_info; }
1739   void set_cached_monitor_info(GrowableArray<MonitorInfo*>* info) { _cached_monitor_info = info; }
1740 
1741   // clearing/querying jni attach status
1742   bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; }
1743   bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
1744   inline void set_done_attaching_via_jni();
1745  private:
1746   // This field is used to determine if a thread has claimed
1747   // a par_id: it is UINT_MAX if the thread has not claimed a par_id;
1748   // otherwise its value is the par_id that has been claimed.
1749   uint _claimed_par_id;
1750  public:
1751   uint get_claimed_par_id() { return _claimed_par_id; }
1752   void set_claimed_par_id(uint id) { _claimed_par_id = id; }
1753 };
1754 
1755 // Inline implementation of JavaThread::current
1756 inline JavaThread* JavaThread::current() {
1757   Thread* thread = ThreadLocalStorage::thread();
1758   assert(thread != NULL && thread->is_Java_thread(), "just checking");
1759   return (JavaThread*)thread;
1760 }
1761 
1762 inline CompilerThread* JavaThread::as_CompilerThread() {
1763   assert(is_Compiler_thread(), "just checking");
1764   return (CompilerThread*)this;
1765 }
1766 
1767 // Dedicated thread to sweep the code cache
1768 class CodeCacheSweeperThread : public JavaThread {
1769   nmethod*       _scanned_nmethod; // nmethod being scanned by the sweeper
1770  public:
1771   CodeCacheSweeperThread();
1772   // Track the nmethod currently being scanned by the sweeper
1773   void set_scanned_nmethod(nmethod* nm) {
1774     assert(_scanned_nmethod == NULL || nm == NULL, "should reset to NULL before writing a new value");
1775     _scanned_nmethod = nm;
1776   }
1777 
1778   // Hide sweeper thread from external view.
1779   bool is_hidden_from_external_view() const { return true; }
1780 
1781   bool is_Code_cache_sweeper_thread() const { return true; }
1782   // GC support
1783   // Apply "f->do_oop" to all root oops in "this".
1784   // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames
1785   void oops_do(OopClosure* f, CLDClosure* cld_f, CodeBlobClosure* cf);
1786 };
1787 
1788 // A thread used for Compilation.
1789 class CompilerThread : public JavaThread {
1790   friend class VMStructs;
1791  private:
1792   CompilerCounters* _counters;
1793 
1794   ciEnv*            _env;
1795   CompileLog*       _log;
1796   CompileTask*      _task;
1797   CompileQueue*     _queue;
1798   BufferBlob*       _buffer_blob;
1799 
1800   AbstractCompiler* _compiler;
1801 
1802  public:
1803 
1804   static CompilerThread* current();
1805 
1806   CompilerThread(CompileQueue* queue, CompilerCounters* counters);
1807 
1808   bool is_Compiler_thread() const                { return true; }
1809   // Hide this compiler thread from external view.
1810   bool is_hidden_from_external_view() const      { return true; }
1811 
1812   void set_compiler(AbstractCompiler* c)         { _compiler = c; }
1813   AbstractCompiler* compiler() const             { return _compiler; }
1814 
1815   CompileQueue* queue()        const             { return _queue; }
1816   CompilerCounters* counters() const             { return _counters; }
1817 
1818   // Get/set the thread's compilation environment.
1819   ciEnv*        env()                            { return _env; }
1820   void          set_env(ciEnv* env)              { _env = env; }
1821 
1822   BufferBlob*   get_buffer_blob() const          { return _buffer_blob; }
1823   void          set_buffer_blob(BufferBlob* b)   { _buffer_blob = b; }
1824 
1825   // Get/set the thread's logging information
1826   CompileLog*   log()                            { return _log; }
1827   void          init_log(CompileLog* log) {
1828     // Set once, for good.
1829     assert(_log == NULL, "set only once");
1830     _log = log;
1831   }
1832 
1833 #ifndef PRODUCT
1834  private:
1835   IdealGraphPrinter *_ideal_graph_printer;
1836  public:
1837   IdealGraphPrinter *ideal_graph_printer()           { return _ideal_graph_printer; }
1838   void set_ideal_graph_printer(IdealGraphPrinter *n) { _ideal_graph_printer = n; }
1839 #endif
1840 
1841   // Get/set the thread's current task
1842   CompileTask* task()                      { return _task; }
1843   void         set_task(CompileTask* task) { _task = task; }
1844 };
1845 
1846 inline CompilerThread* CompilerThread::current() {
1847   return JavaThread::current()->as_CompilerThread();
1848 }
1849 
1850 // The active thread queue. It also keeps track of the current used
1851 // thread priorities.
1852 class Threads: AllStatic {
1853   friend class VMStructs;
1854  private:
1855   static JavaThread* _thread_list;
1856   static int         _number_of_threads;
1857   static int         _number_of_non_daemon_threads;
1858   static int         _return_code;
1859   static int         _thread_claim_parity;
1860 #ifdef ASSERT
1861   static bool        _vm_complete;
1862 #endif
1863 
1864   static void initialize_java_lang_classes(JavaThread* main_thread, TRAPS);
1865   static void initialize_jsr292_core_classes(TRAPS);
1866  public:
1867   // Thread management
1868   // force_daemon is a concession to JNI, where we may need to add a
1869   // thread to the thread list before allocating its thread object
1870   static void add(JavaThread* p, bool force_daemon = false);
1871   static void remove(JavaThread* p);
1872   static bool includes(JavaThread* p);
1873   static JavaThread* first()                     { return _thread_list; }
1874   static void threads_do(ThreadClosure* tc);
1875 
1876   // Initializes the vm and creates the vm thread
1877   static jint create_vm(JavaVMInitArgs* args, bool* canTryAgain);
1878   static void convert_vm_init_libraries_to_agents();
1879   static void create_vm_init_libraries();
1880   static void create_vm_init_agents();
1881   static void shutdown_vm_agents();
1882   static bool destroy_vm();
1883   // Supported VM versions via JNI
1884   // Includes JNI_VERSION_1_1
1885   static jboolean is_supported_jni_version_including_1_1(jint version);
1886   // Does not include JNI_VERSION_1_1
1887   static jboolean is_supported_jni_version(jint version);
1888 
1889   // The "thread claim parity" provides a way for threads to be claimed
1890   // by parallel worker tasks.
1891   //
1892   // Each thread contains a a "parity" field. A task will claim the
1893   // thread only if its parity field is the same as the global parity,
1894   // which is updated by calling change_thread_claim_parity().
1895   //
1896   // For this to work change_thread_claim_parity() needs to be called
1897   // exactly once in sequential code before starting parallel tasks
1898   // that should claim threads.
1899   //
1900   // New threads get their parity set to 0 and change_thread_claim_parity()
1901   // never set the global parity to 0.
1902   static int thread_claim_parity() { return _thread_claim_parity; }
1903   static void change_thread_claim_parity();
1904   static void assert_all_threads_claimed() PRODUCT_RETURN;
1905 
1906   // Apply "f->do_oop" to all root oops in all threads.
1907   // This version may only be called by sequential code.
1908   static void oops_do(OopClosure* f, CLDClosure* cld_f, CodeBlobClosure* cf);
1909   // This version may be called by sequential or parallel code.
1910   static void possibly_parallel_oops_do(bool is_par, OopClosure* f, CLDClosure* cld_f, CodeBlobClosure* cf);
1911   // This creates a list of GCTasks, one per thread.
1912   static void create_thread_roots_tasks(GCTaskQueue* q);
1913   // This creates a list of GCTasks, one per thread, for marking objects.
1914   static void create_thread_roots_marking_tasks(GCTaskQueue* q);
1915 
1916   // Apply "f->do_oop" to roots in all threads that
1917   // are part of compiled frames
1918   static void compiled_frame_oops_do(OopClosure* f, CodeBlobClosure* cf);
1919 
1920   static void convert_hcode_pointers();
1921   static void restore_hcode_pointers();
1922 
1923   // Sweeper
1924   static void nmethods_do(CodeBlobClosure* cf);
1925 
1926   // RedefineClasses support
1927   static void metadata_do(void f(Metadata*));
1928   static void metadata_handles_do(void f(Metadata*));
1929 
1930 #ifdef ASSERT
1931   static bool is_vm_complete() { return _vm_complete; }
1932 #endif
1933 
1934   // Verification
1935   static void verify();
1936   static void print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks);
1937   static void print(bool print_stacks, bool internal_format) {
1938     // this function is only used by debug.cpp
1939     print_on(tty, print_stacks, internal_format, false /* no concurrent lock printed */);
1940   }
1941   static void print_on_error(outputStream* st, Thread* current, char* buf, int buflen);
1942 
1943   // Get Java threads that are waiting to enter a monitor. If doLock
1944   // is true, then Threads_lock is grabbed as needed. Otherwise, the
1945   // VM needs to be at a safepoint.
1946   static GrowableArray<JavaThread*>* get_pending_threads(int count,
1947                                                          address monitor, bool doLock);
1948 
1949   // Get owning Java thread from the monitor's owner field. If doLock
1950   // is true, then Threads_lock is grabbed as needed. Otherwise, the
1951   // VM needs to be at a safepoint.
1952   static JavaThread *owning_thread_from_monitor_owner(address owner,
1953                                                       bool doLock);
1954 
1955   // Number of threads on the active threads list
1956   static int number_of_threads()                 { return _number_of_threads; }
1957   // Number of non-daemon threads on the active threads list
1958   static int number_of_non_daemon_threads()      { return _number_of_non_daemon_threads; }
1959 
1960   // Deoptimizes all frames tied to marked nmethods
1961   static void deoptimized_wrt_marked_nmethods();
1962 
1963   static JavaThread* find_java_thread_from_java_tid(jlong java_tid);
1964 
1965 };
1966 
1967 
1968 // Thread iterator
1969 class ThreadClosure: public StackObj {
1970  public:
1971   virtual void do_thread(Thread* thread) = 0;
1972 };
1973 
1974 class SignalHandlerMark: public StackObj {
1975  private:
1976   Thread* _thread;
1977  public:
1978   SignalHandlerMark(Thread* t) {
1979     _thread = t;
1980     if (_thread) _thread->enter_signal_handler();
1981   }
1982   ~SignalHandlerMark() {
1983     if (_thread) _thread->leave_signal_handler();
1984     _thread = NULL;
1985   }
1986 };
1987 
1988 
1989 #endif // SHARE_VM_RUNTIME_THREAD_HPP