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 "gc/shared/threadLocalAllocBuffer.hpp"
  29 #include "memory/allocation.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/g1/dirtyCardQueue.hpp"
  52 #include "gc/g1/satbQueue.hpp"
  53 #endif // INCLUDE_ALL_GCS
  54 #ifdef TARGET_ARCH_zero
  55 # include "stack_zero.hpp"
  56 #endif
  57 
  58 class ThreadSafepointState;
  59 class ThreadProfiler;
  60 
  61 class JvmtiThreadState;
  62 class JvmtiGetLoadedClassesClosure;
  63 class ThreadStatistics;
  64 class ConcurrentLocksDump;
  65 class ParkEvent;
  66 class Parker;
  67 
  68 class ciEnv;
  69 class CompileThread;
  70 class CompileLog;
  71 class CompileTask;
  72 class CompileQueue;
  73 class CompilerCounters;
  74 class vframeArray;
  75 
  76 class DeoptResourceMark;
  77 class jvmtiDeferredLocalVariableSet;
  78 
  79 class GCTaskQueue;
  80 class ThreadClosure;
  81 class IdealGraphPrinter;
  82 
  83 class Metadata;
  84 template <class T, MEMFLAGS F> class ChunkedList;
  85 typedef ChunkedList<Metadata*, mtInternal> MetadataOnStackBuffer;
  86 
  87 DEBUG_ONLY(class ResourceMark;)
  88 
  89 class WorkerThread;
  90 
  91 // Class hierarchy
  92 // - Thread
  93 //   - NamedThread
  94 //     - VMThread
  95 //     - ConcurrentGCThread
  96 //     - WorkerThread
  97 //       - GangWorker
  98 //       - GCTaskThread
  99 //   - JavaThread
 100 //   - WatcherThread
 101 
 102 class Thread: public ThreadShadow {
 103   friend class VMStructs;
 104  private:
 105   // Exception handling
 106   // (Note: _pending_exception and friends are in ThreadShadow)
 107   //oop       _pending_exception;                // pending exception for current thread
 108   // const char* _exception_file;                   // file information for exception (debugging only)
 109   // int         _exception_line;                   // line information for exception (debugging only)
 110  protected:
 111   // Support for forcing alignment of thread objects for biased locking
 112   void*       _real_malloc_address;
 113  public:
 114   void* operator new(size_t size) throw() { return allocate(size, true); }
 115   void* operator new(size_t size, const std::nothrow_t& nothrow_constant) throw() {
 116     return allocate(size, false); }
 117   void  operator delete(void* p);
 118 
 119  protected:
 120   static void* allocate(size_t size, bool throw_excpt, MEMFLAGS flags = mtThread);
 121  private:
 122 
 123   // ***************************************************************
 124   // Suspend and resume support
 125   // ***************************************************************
 126   //
 127   // VM suspend/resume no longer exists - it was once used for various
 128   // things including safepoints but was deprecated and finally removed
 129   // in Java 7. Because VM suspension was considered "internal" Java-level
 130   // suspension was considered "external", and this legacy naming scheme
 131   // remains.
 132   //
 133   // External suspend/resume requests come from JVM_SuspendThread,
 134   // JVM_ResumeThread, JVMTI SuspendThread, and finally JVMTI
 135   // ResumeThread. External
 136   // suspend requests cause _external_suspend to be set and external
 137   // resume requests cause _external_suspend to be cleared.
 138   // External suspend requests do not nest on top of other external
 139   // suspend requests. The higher level APIs reject suspend requests
 140   // for already suspended threads.
 141   //
 142   // The external_suspend
 143   // flag is checked by has_special_runtime_exit_condition() and java thread
 144   // will self-suspend when handle_special_runtime_exit_condition() is
 145   // called. Most uses of the _thread_blocked state in JavaThreads are
 146   // considered the same as being externally suspended; if the blocking
 147   // condition lifts, the JavaThread will self-suspend. Other places
 148   // where VM checks for external_suspend include:
 149   //   + mutex granting (do not enter monitors when thread is suspended)
 150   //   + state transitions from _thread_in_native
 151   //
 152   // In general, java_suspend() does not wait for an external suspend
 153   // request to complete. When it returns, the only guarantee is that
 154   // the _external_suspend field is true.
 155   //
 156   // wait_for_ext_suspend_completion() is used to wait for an external
 157   // suspend request to complete. External suspend requests are usually
 158   // followed by some other interface call that requires the thread to
 159   // be quiescent, e.g., GetCallTrace(). By moving the "wait time" into
 160   // the interface that requires quiescence, we give the JavaThread a
 161   // chance to self-suspend before we need it to be quiescent. This
 162   // improves overall suspend/query performance.
 163   //
 164   // _suspend_flags controls the behavior of java_ suspend/resume.
 165   // It must be set under the protection of SR_lock. Read from the flag is
 166   // OK without SR_lock as long as the value is only used as a hint.
 167   // (e.g., check _external_suspend first without lock and then recheck
 168   // inside SR_lock and finish the suspension)
 169   //
 170   // _suspend_flags is also overloaded for other "special conditions" so
 171   // that a single check indicates whether any special action is needed
 172   // eg. for async exceptions.
 173   // -------------------------------------------------------------------
 174   // Notes:
 175   // 1. The suspend/resume logic no longer uses ThreadState in OSThread
 176   // but we still update its value to keep other part of the system (mainly
 177   // JVMTI) happy. ThreadState is legacy code (see notes in
 178   // osThread.hpp).
 179   //
 180   // 2. It would be more natural if set_external_suspend() is private and
 181   // part of java_suspend(), but that probably would affect the suspend/query
 182   // performance. Need more investigation on this.
 183 
 184   // suspend/resume lock: used for self-suspend
 185   Monitor* _SR_lock;
 186 
 187  protected:
 188   enum SuspendFlags {
 189     // NOTE: avoid using the sign-bit as cc generates different test code
 190     //       when the sign-bit is used, and sometimes incorrectly - see CR 6398077
 191 
 192     _external_suspend       = 0x20000000U, // thread is asked to self suspend
 193     _ext_suspended          = 0x40000000U, // thread has self-suspended
 194     _deopt_suspend          = 0x10000000U, // thread needs to self suspend for deopt
 195 
 196     _has_async_exception    = 0x00000001U, // there is a pending async exception
 197     _critical_native_unlock = 0x00000002U  // Must call back to unlock JNI critical lock
 198   };
 199 
 200   // various suspension related flags - atomically updated
 201   // overloaded for async exception checking in check_special_condition_for_native_trans.
 202   volatile uint32_t _suspend_flags;
 203 
 204  private:
 205   int _num_nested_signal;
 206 
 207   DEBUG_ONLY(bool _suspendible_thread;)
 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 #ifdef ASSERT
 215   void set_suspendible_thread() {
 216     _suspendible_thread = true;
 217   }
 218 
 219   void clear_suspendible_thread() {
 220     _suspendible_thread = false;
 221   }
 222 
 223   bool is_suspendible_thread() { return _suspendible_thread; }
 224 #endif
 225 
 226  private:
 227   // Active_handles points to a block of handles
 228   JNIHandleBlock* _active_handles;
 229 
 230   // One-element thread local free list
 231   JNIHandleBlock* _free_handle_block;
 232 
 233   // Point to the last handle mark
 234   HandleMark* _last_handle_mark;
 235 
 236   // The parity of the last strong_roots iteration in which this thread was
 237   // claimed as a task.
 238   jint _oops_do_parity;
 239 
 240  public:
 241   void set_last_handle_mark(HandleMark* mark)   { _last_handle_mark = mark; }
 242   HandleMark* last_handle_mark() const          { return _last_handle_mark; }
 243  private:
 244 
 245   // debug support for checking if code does allow safepoints or not
 246   // GC points in the VM can happen because of allocation, invoking a VM operation, or blocking on
 247   // mutex, or blocking on an object synchronizer (Java locking).
 248   // If !allow_safepoint(), then an assertion failure will happen in any of the above cases
 249   // If !allow_allocation(), then an assertion failure will happen during allocation
 250   // (Hence, !allow_safepoint() => !allow_allocation()).
 251   //
 252   // The two classes No_Safepoint_Verifier and No_Allocation_Verifier are used to set these counters.
 253   //
 254   NOT_PRODUCT(int _allow_safepoint_count;)      // If 0, thread allow a safepoint to happen
 255   debug_only(int _allow_allocation_count;)     // If 0, the thread is allowed to allocate oops.
 256 
 257   // Used by SkipGCALot class.
 258   NOT_PRODUCT(bool _skip_gcalot;)               // Should we elide gc-a-lot?
 259 
 260   friend class No_Alloc_Verifier;
 261   friend class No_Safepoint_Verifier;
 262   friend class Pause_No_Safepoint_Verifier;
 263   friend class ThreadLocalStorage;
 264   friend class GC_locker;
 265 
 266   ThreadLocalAllocBuffer _tlab;                 // Thread-local eden
 267   jlong _allocated_bytes;                       // Cumulative number of bytes allocated on
 268                                                 // the Java heap
 269 
 270   TRACE_DATA _trace_data;                       // Thread-local data for tracing
 271 
 272   ThreadExt _ext;
 273 
 274   int   _vm_operation_started_count;            // VM_Operation support
 275   int   _vm_operation_completed_count;          // VM_Operation support
 276 
 277   ObjectMonitor* _current_pending_monitor;      // ObjectMonitor this thread
 278                                                 // is waiting to lock
 279   bool _current_pending_monitor_is_from_java;   // locking is from Java code
 280 
 281   // ObjectMonitor on which this thread called Object.wait()
 282   ObjectMonitor* _current_waiting_monitor;
 283 
 284   // Private thread-local objectmonitor list - a simple cache organized as a SLL.
 285  public:
 286   ObjectMonitor* omFreeList;
 287   int omFreeCount;                              // length of omFreeList
 288   int omFreeProvision;                          // reload chunk size
 289   ObjectMonitor* omInUseList;                   // SLL to track monitors in circulation
 290   int omInUseCount;                             // length of omInUseList
 291 
 292 #ifdef ASSERT
 293  private:
 294   bool _visited_for_critical_count;
 295 
 296  public:
 297   void set_visited_for_critical_count(bool z) { _visited_for_critical_count = z; }
 298   bool was_visited_for_critical_count() const   { return _visited_for_critical_count; }
 299 #endif
 300 
 301  public:
 302   enum {
 303     is_definitely_current_thread = true
 304   };
 305 
 306   // Constructor
 307   Thread();
 308   virtual ~Thread();
 309 
 310   // initializtion
 311   void initialize_thread_local_storage();
 312 
 313   // thread entry point
 314   virtual void run();
 315 
 316   // Testers
 317   virtual bool is_VM_thread()       const            { return false; }
 318   virtual bool is_Java_thread()     const            { return false; }
 319   virtual bool is_Compiler_thread() const            { return false; }
 320   virtual bool is_Code_cache_sweeper_thread() const  { return false; }
 321   virtual bool is_hidden_from_external_view() const  { return false; }
 322   virtual bool is_jvmti_agent_thread() const         { return false; }
 323   // True iff the thread can perform GC operations at a safepoint.
 324   // Generally will be true only of VM thread and parallel GC WorkGang
 325   // threads.
 326   virtual bool is_GC_task_thread() const             { return false; }
 327   virtual bool is_Watcher_thread() const             { return false; }
 328   virtual bool is_ConcurrentGC_thread() const        { return false; }
 329   virtual bool is_Named_thread() const               { return false; }
 330   virtual bool is_Worker_thread() const              { return false; }
 331 
 332   // Can this thread make Java upcalls
 333   virtual bool can_call_java() const                 { return false; }
 334 
 335   // Casts
 336   virtual WorkerThread* as_Worker_thread() const     { return NULL; }
 337 
 338   virtual char* name() const { return (char*)"Unknown thread"; }
 339 
 340   // Returns the current thread
 341   static inline Thread* current();
 342   // ... without having to include thread.inline.hpp.
 343   static Thread* current_noinline();
 344 
 345   // Common thread operations
 346   static void set_priority(Thread* thread, ThreadPriority priority);
 347   static ThreadPriority get_priority(const Thread* const thread);
 348   static void start(Thread* thread);
 349   static void interrupt(Thread* thr);
 350   static bool is_interrupted(Thread* thr, bool clear_interrupted);
 351 
 352   void set_native_thread_name(const char *name) {
 353     assert(Thread::current() == this, "set_native_thread_name can only be called on the current thread");
 354     os::set_native_thread_name(name);
 355   }
 356 
 357   ObjectMonitor** omInUseList_addr()             { return (ObjectMonitor **)&omInUseList; }
 358   Monitor* SR_lock() const                       { return _SR_lock; }
 359 
 360   bool has_async_exception() const { return (_suspend_flags & _has_async_exception) != 0; }
 361 
 362   inline void set_suspend_flag(SuspendFlags f);
 363   inline void clear_suspend_flag(SuspendFlags f);
 364 
 365   inline void set_has_async_exception();
 366   inline void clear_has_async_exception();
 367 
 368   bool do_critical_native_unlock() const { return (_suspend_flags & _critical_native_unlock) != 0; }
 369 
 370   inline void set_critical_native_unlock();
 371   inline void clear_critical_native_unlock();
 372 
 373   // Support for Unhandled Oop detection
 374   // Add the field for both, fastdebug and debug, builds to keep
 375   // Thread's fields layout the same.
 376   // Note: CHECK_UNHANDLED_OOPS is defined only for fastdebug build.
 377 #ifdef CHECK_UNHANDLED_OOPS
 378  private:
 379   UnhandledOops* _unhandled_oops;
 380 #elif defined(ASSERT)
 381  private:
 382   void* _unhandled_oops;
 383 #endif
 384 #ifdef CHECK_UNHANDLED_OOPS
 385  public:
 386   UnhandledOops* unhandled_oops() { return _unhandled_oops; }
 387   // Mark oop safe for gc.  It may be stack allocated but won't move.
 388   void allow_unhandled_oop(oop *op) {
 389     if (CheckUnhandledOops) unhandled_oops()->allow_unhandled_oop(op);
 390   }
 391   // Clear oops at safepoint so crashes point to unhandled oop violator
 392   void clear_unhandled_oops() {
 393     if (CheckUnhandledOops) unhandled_oops()->clear_unhandled_oops();
 394   }
 395 #endif // CHECK_UNHANDLED_OOPS
 396 
 397  public:
 398 #ifndef PRODUCT
 399   bool skip_gcalot()           { return _skip_gcalot; }
 400   void set_skip_gcalot(bool v) { _skip_gcalot = v;    }
 401 #endif
 402 
 403   // Installs a pending exception to be inserted later
 404   static void send_async_exception(oop thread_oop, oop java_throwable);
 405 
 406   // Resource area
 407   ResourceArea* resource_area() const            { return _resource_area; }
 408   void set_resource_area(ResourceArea* area)     { _resource_area = area; }
 409 
 410   OSThread* osthread() const                     { return _osthread;   }
 411   void set_osthread(OSThread* thread)            { _osthread = thread; }
 412 
 413   // JNI handle support
 414   JNIHandleBlock* active_handles() const         { return _active_handles; }
 415   void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
 416   JNIHandleBlock* free_handle_block() const      { return _free_handle_block; }
 417   void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
 418 
 419   // Internal handle support
 420   HandleArea* handle_area() const                { return _handle_area; }
 421   void set_handle_area(HandleArea* area)         { _handle_area = area; }
 422 
 423   GrowableArray<Metadata*>* metadata_handles() const          { return _metadata_handles; }
 424   void set_metadata_handles(GrowableArray<Metadata*>* handles){ _metadata_handles = handles; }
 425 
 426   // Thread-Local Allocation Buffer (TLAB) support
 427   ThreadLocalAllocBuffer& tlab()                 { return _tlab; }
 428   void initialize_tlab() {
 429     if (UseTLAB) {
 430       tlab().initialize();
 431     }
 432   }
 433 
 434   jlong allocated_bytes()               { return _allocated_bytes; }
 435   void set_allocated_bytes(jlong value) { _allocated_bytes = value; }
 436   void incr_allocated_bytes(jlong size) { _allocated_bytes += size; }
 437   inline jlong cooked_allocated_bytes();
 438 
 439   TRACE_DATA* trace_data()              { return &_trace_data; }
 440 
 441   const ThreadExt& ext() const          { return _ext; }
 442   ThreadExt& ext()                      { return _ext; }
 443 
 444   // VM operation support
 445   int vm_operation_ticket()                      { return ++_vm_operation_started_count; }
 446   int vm_operation_completed_count()             { return _vm_operation_completed_count; }
 447   void increment_vm_operation_completed_count()  { _vm_operation_completed_count++; }
 448 
 449   // For tracking the heavyweight monitor the thread is pending on.
 450   ObjectMonitor* current_pending_monitor() {
 451     return _current_pending_monitor;
 452   }
 453   void set_current_pending_monitor(ObjectMonitor* monitor) {
 454     _current_pending_monitor = monitor;
 455   }
 456   void set_current_pending_monitor_is_from_java(bool from_java) {
 457     _current_pending_monitor_is_from_java = from_java;
 458   }
 459   bool current_pending_monitor_is_from_java() {
 460     return _current_pending_monitor_is_from_java;
 461   }
 462 
 463   // For tracking the ObjectMonitor on which this thread called Object.wait()
 464   ObjectMonitor* current_waiting_monitor() {
 465     return _current_waiting_monitor;
 466   }
 467   void set_current_waiting_monitor(ObjectMonitor* monitor) {
 468     _current_waiting_monitor = monitor;
 469   }
 470 
 471   // GC support
 472   // Apply "f->do_oop" to all root oops in "this".
 473   // Apply "cld_f->do_cld" to CLDs that are otherwise not kept alive.
 474   //   Used by JavaThread::oops_do.
 475   // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames
 476   virtual void oops_do(OopClosure* f, CLDClosure* cld_f, CodeBlobClosure* cf);
 477 
 478   // Handles the parallel case for the method below.
 479  private:
 480   bool claim_oops_do_par_case(int collection_parity);
 481  public:
 482   // Requires that "collection_parity" is that of the current roots
 483   // iteration.  If "is_par" is false, sets the parity of "this" to
 484   // "collection_parity", and returns "true".  If "is_par" is true,
 485   // uses an atomic instruction to set the current threads parity to
 486   // "collection_parity", if it is not already.  Returns "true" iff the
 487   // calling thread does the update, this indicates that the calling thread
 488   // has claimed the thread's stack as a root groop in the current
 489   // collection.
 490   bool claim_oops_do(bool is_par, int collection_parity) {
 491     if (!is_par) {
 492       _oops_do_parity = collection_parity;
 493       return true;
 494     } else {
 495       return claim_oops_do_par_case(collection_parity);
 496     }
 497   }
 498 
 499   // Sweeper support
 500   void nmethods_do(CodeBlobClosure* cf);
 501 
 502   // jvmtiRedefineClasses support
 503   void metadata_handles_do(void f(Metadata*));
 504 
 505   // Used by fast lock support
 506   virtual bool is_lock_owned(address adr) const;
 507 
 508   // Check if address is in the stack of the thread (not just for locks).
 509   // Warning: the method can only be used on the running thread
 510   bool is_in_stack(address adr) const;
 511   // Check if address is in the usable part of the stack (excludes protected
 512   // guard pages)
 513   bool is_in_usable_stack(address adr) const;
 514 
 515   // Sets this thread as starting thread. Returns failure if thread
 516   // creation fails due to lack of memory, too many threads etc.
 517   bool set_as_starting_thread();
 518 
 519 protected:
 520   // OS data associated with the thread
 521   OSThread* _osthread;  // Platform-specific thread information
 522 
 523   // Thread local resource area for temporary allocation within the VM
 524   ResourceArea* _resource_area;
 525 
 526   DEBUG_ONLY(ResourceMark* _current_resource_mark;)
 527 
 528   // Thread local handle area for allocation of handles within the VM
 529   HandleArea* _handle_area;
 530   GrowableArray<Metadata*>* _metadata_handles;
 531 
 532   // Support for stack overflow handling, get_thread, etc.
 533   address          _stack_base;
 534   size_t           _stack_size;
 535   uintptr_t        _self_raw_id;      // used by get_thread (mutable)
 536   int              _lgrp_id;
 537 
 538  public:
 539   // Stack overflow support
 540   address stack_base() const           { assert(_stack_base != NULL,"Sanity check"); return _stack_base; }
 541 
 542   void    set_stack_base(address base) { _stack_base = base; }
 543   size_t  stack_size() const           { return _stack_size; }
 544   void    set_stack_size(size_t size)  { _stack_size = size; }
 545   void    record_stack_base_and_size();
 546 
 547   bool    on_local_stack(address adr) const {
 548     // QQQ this has knowledge of direction, ought to be a stack method
 549     return (_stack_base >= adr && adr >= (_stack_base - _stack_size));
 550   }
 551 
 552   uintptr_t self_raw_id()                    { return _self_raw_id; }
 553   void      set_self_raw_id(uintptr_t value) { _self_raw_id = value; }
 554 
 555   int     lgrp_id() const        { return _lgrp_id; }
 556   void    set_lgrp_id(int value) { _lgrp_id = value; }
 557 
 558   // Printing
 559   virtual void print_on(outputStream* st) const;
 560   void print() const { print_on(tty); }
 561   virtual void print_on_error(outputStream* st, char* buf, int buflen) const;
 562 
 563   // Debug-only code
 564 #ifdef ASSERT
 565  private:
 566   // Deadlock detection support for Mutex locks. List of locks own by thread.
 567   Monitor* _owned_locks;
 568   // Mutex::set_owner_implementation is the only place where _owned_locks is modified,
 569   // thus the friendship
 570   friend class Mutex;
 571   friend class Monitor;
 572 
 573  public:
 574   void print_owned_locks_on(outputStream* st) const;
 575   void print_owned_locks() const                 { print_owned_locks_on(tty);    }
 576   Monitor* owned_locks() const                   { return _owned_locks;          }
 577   bool owns_locks() const                        { return owned_locks() != NULL; }
 578   bool owns_locks_but_compiled_lock() const;
 579   int oops_do_parity() const                     { return _oops_do_parity; }
 580 
 581   // Deadlock detection
 582   bool allow_allocation()                        { return _allow_allocation_count == 0; }
 583   ResourceMark* current_resource_mark()          { return _current_resource_mark; }
 584   void set_current_resource_mark(ResourceMark* rm) { _current_resource_mark = rm; }
 585 #endif
 586 
 587   void check_for_valid_safepoint_state(bool potential_vm_operation) PRODUCT_RETURN;
 588 
 589  private:
 590   volatile int _jvmti_env_iteration_count;
 591 
 592  public:
 593   void entering_jvmti_env_iteration()            { ++_jvmti_env_iteration_count; }
 594   void leaving_jvmti_env_iteration()             { --_jvmti_env_iteration_count; }
 595   bool is_inside_jvmti_env_iteration()           { return _jvmti_env_iteration_count > 0; }
 596 
 597   // Code generation
 598   static ByteSize exception_file_offset()        { return byte_offset_of(Thread, _exception_file); }
 599   static ByteSize exception_line_offset()        { return byte_offset_of(Thread, _exception_line); }
 600   static ByteSize active_handles_offset()        { return byte_offset_of(Thread, _active_handles); }
 601 
 602   static ByteSize stack_base_offset()            { return byte_offset_of(Thread, _stack_base); }
 603   static ByteSize stack_size_offset()            { return byte_offset_of(Thread, _stack_size); }
 604 
 605 #define TLAB_FIELD_OFFSET(name) \
 606   static ByteSize tlab_##name##_offset()         { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::name##_offset(); }
 607 
 608   TLAB_FIELD_OFFSET(start)
 609   TLAB_FIELD_OFFSET(end)
 610   TLAB_FIELD_OFFSET(top)
 611   TLAB_FIELD_OFFSET(pf_top)
 612   TLAB_FIELD_OFFSET(size)                   // desired_size
 613   TLAB_FIELD_OFFSET(refill_waste_limit)
 614   TLAB_FIELD_OFFSET(number_of_refills)
 615   TLAB_FIELD_OFFSET(fast_refill_waste)
 616   TLAB_FIELD_OFFSET(slow_allocations)
 617 
 618 #undef TLAB_FIELD_OFFSET
 619 
 620   static ByteSize allocated_bytes_offset()       { return byte_offset_of(Thread, _allocated_bytes); }
 621 
 622  public:
 623   volatile intptr_t _Stalled;
 624   volatile int _TypeTag;
 625   ParkEvent * _ParkEvent;                     // for synchronized()
 626   ParkEvent * _SleepEvent;                    // for Thread.sleep
 627   ParkEvent * _MutexEvent;                    // for native internal Mutex/Monitor
 628   ParkEvent * _MuxEvent;                      // for low-level muxAcquire-muxRelease
 629   int NativeSyncRecursion;                    // diagnostic
 630 
 631   volatile int _OnTrap;                       // Resume-at IP delta
 632   jint _hashStateW;                           // Marsaglia Shift-XOR thread-local RNG
 633   jint _hashStateX;                           // thread-specific hashCode generator state
 634   jint _hashStateY;
 635   jint _hashStateZ;
 636   void * _schedctl;
 637 
 638 
 639   volatile jint rng[4];                      // RNG for spin loop
 640 
 641   // Low-level leaf-lock primitives used to implement synchronization
 642   // and native monitor-mutex infrastructure.
 643   // Not for general synchronization use.
 644   static void SpinAcquire(volatile int * Lock, const char * Name);
 645   static void SpinRelease(volatile int * Lock);
 646   static void muxAcquire(volatile intptr_t * Lock, const char * Name);
 647   static void muxAcquireW(volatile intptr_t * Lock, ParkEvent * ev);
 648   static void muxRelease(volatile intptr_t * Lock);
 649 };
 650 
 651 // Inline implementation of Thread::current()
 652 // Thread::current is "hot" it's called > 128K times in the 1st 500 msecs of
 653 // startup.
 654 // ThreadLocalStorage::thread is warm -- it's called > 16K times in the same
 655 // period.   This is inlined in thread_<os_family>.inline.hpp.
 656 
 657 inline Thread* Thread::current() {
 658 #ifdef ASSERT
 659   // This function is very high traffic. Define PARANOID to enable expensive
 660   // asserts.
 661 #ifdef PARANOID
 662   // Signal handler should call ThreadLocalStorage::get_thread_slow()
 663   Thread* t = ThreadLocalStorage::get_thread_slow();
 664   assert(t != NULL && !t->is_inside_signal_handler(),
 665          "Don't use Thread::current() inside signal handler");
 666 #endif
 667 #endif
 668   Thread* thread = ThreadLocalStorage::thread();
 669   assert(thread != NULL, "just checking");
 670   return thread;
 671 }
 672 
 673 // Name support for threads.  non-JavaThread subclasses with multiple
 674 // uniquely named instances should derive from this.
 675 class NamedThread: public Thread {
 676   friend class VMStructs;
 677   enum {
 678     max_name_len = 64
 679   };
 680  private:
 681   char* _name;
 682   // log JavaThread being processed by oops_do
 683   JavaThread* _processed_thread;
 684 
 685  public:
 686   NamedThread();
 687   ~NamedThread();
 688   // May only be called once per thread.
 689   void set_name(const char* format, ...)  ATTRIBUTE_PRINTF(2, 3);
 690   void initialize_named_thread();
 691   virtual bool is_Named_thread() const { return true; }
 692   virtual char* name() const { return _name == NULL ? (char*)"Unknown Thread" : _name; }
 693   JavaThread *processed_thread() { return _processed_thread; }
 694   void set_processed_thread(JavaThread *thread) { _processed_thread = thread; }
 695   virtual void print_on(outputStream* st) const;
 696 };
 697 
 698 // Worker threads are named and have an id of an assigned work.
 699 class WorkerThread: public NamedThread {
 700  private:
 701   uint _id;
 702  public:
 703   WorkerThread() : _id(0)               { }
 704   virtual bool is_Worker_thread() const { return true; }
 705 
 706   virtual WorkerThread* as_Worker_thread() const {
 707     assert(is_Worker_thread(), "Dubious cast to WorkerThread*?");
 708     return (WorkerThread*) this;
 709   }
 710 
 711   void set_id(uint work_id)             { _id = work_id; }
 712   uint id() const                       { return _id; }
 713 };
 714 
 715 // A single WatcherThread is used for simulating timer interrupts.
 716 class WatcherThread: public Thread {
 717   friend class VMStructs;
 718  public:
 719   virtual void run();
 720 
 721  private:
 722   static WatcherThread* _watcher_thread;
 723 
 724   static bool _startable;
 725   // volatile due to at least one lock-free read
 726   volatile static bool _should_terminate;
 727 
 728   os::WatcherThreadCrashProtection* _crash_protection;
 729  public:
 730   enum SomeConstants {
 731     delay_interval = 10                          // interrupt delay in milliseconds
 732   };
 733 
 734   // Constructor
 735   WatcherThread();
 736 
 737   // Tester
 738   bool is_Watcher_thread() const                 { return true; }
 739 
 740   // Printing
 741   char* name() const { return (char*)"VM Periodic Task Thread"; }
 742   void print_on(outputStream* st) const;
 743   void unpark();
 744 
 745   // Returns the single instance of WatcherThread
 746   static WatcherThread* watcher_thread()         { return _watcher_thread; }
 747 
 748   // Create and start the single instance of WatcherThread, or stop it on shutdown
 749   static void start();
 750   static void stop();
 751   // Only allow start once the VM is sufficiently initialized
 752   // Otherwise the first task to enroll will trigger the start
 753   static void make_startable();
 754 
 755   void set_crash_protection(os::WatcherThreadCrashProtection* crash_protection) {
 756     assert(Thread::current()->is_Watcher_thread(), "Can only be set by WatcherThread");
 757     _crash_protection = crash_protection;
 758   }
 759 
 760   bool has_crash_protection() const { return _crash_protection != NULL; }
 761   os::WatcherThreadCrashProtection* crash_protection() const { return _crash_protection; }
 762 
 763  private:
 764   int sleep() const;
 765 };
 766 
 767 
 768 class CompilerThread;
 769 
 770 typedef void (*ThreadFunction)(JavaThread*, TRAPS);
 771 
 772 class JavaThread: public Thread {
 773   friend class VMStructs;
 774   friend class WhiteBox;
 775  private:
 776   JavaThread*    _next;                          // The next thread in the Threads list
 777   oop            _threadObj;                     // The Java level thread object
 778 
 779 #ifdef ASSERT
 780  private:
 781   int _java_call_counter;
 782 
 783  public:
 784   int  java_call_counter()                       { return _java_call_counter; }
 785   void inc_java_call_counter()                   { _java_call_counter++; }
 786   void dec_java_call_counter() {
 787     assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
 788     _java_call_counter--;
 789   }
 790  private:  // restore original namespace restriction
 791 #endif  // ifdef ASSERT
 792 
 793 #ifndef PRODUCT
 794  public:
 795   enum {
 796     jump_ring_buffer_size = 16
 797   };
 798  private:  // restore original namespace restriction
 799 #endif
 800 
 801   JavaFrameAnchor _anchor;                       // Encapsulation of current java frame and it state
 802 
 803   ThreadFunction _entry_point;
 804 
 805   JNIEnv        _jni_environment;
 806 
 807   // Deopt support
 808   DeoptResourceMark*  _deopt_mark;               // Holds special ResourceMark for deoptimization
 809 
 810   intptr_t*      _must_deopt_id;                 // id of frame that needs to be deopted once we
 811                                                  // transition out of native
 812   nmethod*       _deopt_nmethod;                 // nmethod that is currently being deoptimized
 813   vframeArray*  _vframe_array_head;              // Holds the heap of the active vframeArrays
 814   vframeArray*  _vframe_array_last;              // Holds last vFrameArray we popped
 815   // Because deoptimization is lazy we must save jvmti requests to set locals
 816   // in compiled frames until we deoptimize and we have an interpreter frame.
 817   // This holds the pointer to array (yeah like there might be more than one) of
 818   // description of compiled vframes that have locals that need to be updated.
 819   GrowableArray<jvmtiDeferredLocalVariableSet*>* _deferred_locals_updates;
 820 
 821   // Handshake value for fixing 6243940. We need a place for the i2c
 822   // adapter to store the callee Method*. This value is NEVER live
 823   // across a gc point so it does NOT have to be gc'd
 824   // The handshake is open ended since we can't be certain that it will
 825   // be NULLed. This is because we rarely ever see the race and end up
 826   // in handle_wrong_method which is the backend of the handshake. See
 827   // code in i2c adapters and handle_wrong_method.
 828 
 829   Method*       _callee_target;
 830 
 831   // Used to pass back results to the interpreter or generated code running Java code.
 832   oop           _vm_result;    // oop result is GC-preserved
 833   Metadata*     _vm_result_2;  // non-oop result
 834 
 835   // See ReduceInitialCardMarks: this holds the precise space interval of
 836   // the most recent slow path allocation for which compiled code has
 837   // elided card-marks for performance along the fast-path.
 838   MemRegion     _deferred_card_mark;
 839 
 840   MonitorChunk* _monitor_chunks;                 // Contains the off stack monitors
 841                                                  // allocated during deoptimization
 842                                                  // and by JNI_MonitorEnter/Exit
 843 
 844   // Async. requests support
 845   enum AsyncRequests {
 846     _no_async_condition = 0,
 847     _async_exception,
 848     _async_unsafe_access_error
 849   };
 850   AsyncRequests _special_runtime_exit_condition; // Enum indicating pending async. request
 851   oop           _pending_async_exception;
 852 
 853   // Safepoint support
 854  public:                                         // Expose _thread_state for SafeFetchInt()
 855   volatile JavaThreadState _thread_state;
 856  private:
 857   ThreadSafepointState *_safepoint_state;        // Holds information about a thread during a safepoint
 858   address               _saved_exception_pc;     // Saved pc of instruction where last implicit exception happened
 859 
 860   // JavaThread termination support
 861   enum TerminatedTypes {
 862     _not_terminated = 0xDEAD - 2,
 863     _thread_exiting,                             // JavaThread::exit() has been called for this thread
 864     _thread_terminated,                          // JavaThread is removed from thread list
 865     _vm_exited                                   // JavaThread is still executing native code, but VM is terminated
 866                                                  // only VM_Exit can set _vm_exited
 867   };
 868 
 869   // In general a JavaThread's _terminated field transitions as follows:
 870   //
 871   //   _not_terminated => _thread_exiting => _thread_terminated
 872   //
 873   // _vm_exited is a special value to cover the case of a JavaThread
 874   // executing native code after the VM itself is terminated.
 875   volatile TerminatedTypes _terminated;
 876   // suspend/resume support
 877   volatile bool         _suspend_equivalent;     // Suspend equivalent condition
 878   jint                  _in_deopt_handler;       // count of deoptimization
 879                                                  // handlers thread is in
 880   volatile bool         _doing_unsafe_access;    // Thread may fault due to unsafe access
 881   bool                  _do_not_unlock_if_synchronized;  // Do not unlock the receiver of a synchronized method (since it was
 882                                                          // never locked) when throwing an exception. Used by interpreter only.
 883 
 884   // JNI attach states:
 885   enum JNIAttachStates {
 886     _not_attaching_via_jni = 1,  // thread is not attaching via JNI
 887     _attaching_via_jni,          // thread is attaching via JNI
 888     _attached_via_jni            // thread has attached via JNI
 889   };
 890 
 891   // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
 892   // A native thread that is attaching via JNI starts with a value
 893   // of _attaching_via_jni and transitions to _attached_via_jni.
 894   volatile JNIAttachStates _jni_attach_state;
 895 
 896  public:
 897   // State of the stack guard pages for this thread.
 898   enum StackGuardState {
 899     stack_guard_unused,         // not needed
 900     stack_guard_yellow_disabled,// disabled (temporarily) after stack overflow
 901     stack_guard_enabled         // enabled
 902   };
 903 
 904  private:
 905 
 906 #if INCLUDE_JVMCI
 907   // The _pending_* fields below are used to communicate extra information
 908   // from an uncommon trap in JVMCI compiled code to the uncommon trap handler.
 909 
 910   // Communicates the DeoptReason and DeoptAction of the uncommon trap
 911   int       _pending_deoptimization;
 912 
 913   // Specifies whether the uncommon trap is to bci 0 of a synchronized method
 914   // before the monitor has been acquired.
 915   bool      _pending_monitorenter;
 916 
 917   // Specifies if the DeoptReason for the last uncommon trap was Reason_transfer_to_interpreter
 918   bool      _pending_transfer_to_interpreter;
 919 
 920   // An object that JVMCI compiled code can use to further describe and
 921   // uniquely identify the  speculative optimization guarded by the uncommon trap
 922   oop       _pending_failed_speculation;
 923 
 924   // These fields are mutually exclusive in terms of live ranges.
 925   union {
 926     // Communicates the pc at which the most recent implicit exception occurred
 927     // from the signal handler to a deoptimization stub.
 928     address   _implicit_exception_pc;
 929 
 930     // Communicates an alternative call target to an i2c stub from a JavaCall .
 931     address   _alternate_call_target;
 932   } _jvmci;
 933 
 934   // Support for high precision, thread sensitive counters in JVMCI compiled code.
 935   jlong*    _jvmci_counters;
 936 
 937  public:
 938   static jlong* _jvmci_old_thread_counters;
 939   static void collect_counters(typeArrayOop array);
 940  private:
 941 #endif // INCLUDE_JVMCI
 942 
 943   StackGuardState  _stack_guard_state;
 944 
 945   // Precompute the limit of the stack as used in stack overflow checks.
 946   // We load it from here to simplify the stack overflow check in assembly.
 947   address          _stack_overflow_limit;
 948 
 949   // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
 950   // used to temp. parsing values into and out of the runtime system during exception handling for compiled
 951   // code)
 952   volatile oop     _exception_oop;               // Exception thrown in compiled code
 953   volatile address _exception_pc;                // PC where exception happened
 954   volatile address _exception_handler_pc;        // PC for handler of exception
 955   volatile int     _is_method_handle_return;     // true (== 1) if the current exception PC is a MethodHandle call site.
 956 
 957  private:  
 958   // support for JNI critical regions
 959   jint    _jni_active_critical;                  // count of entries into JNI critical region
 960 
 961   // Checked JNI: function name requires exception check
 962   char* _pending_jni_exception_check_fn;
 963 
 964   // For deadlock detection.
 965   int _depth_first_number;
 966 
 967   // JVMTI PopFrame support
 968   // This is set to popframe_pending to signal that top Java frame should be popped immediately
 969   int _popframe_condition;
 970 
 971   // If reallocation of scalar replaced objects fails, we throw OOM
 972   // and during exception propagation, pop the top
 973   // _frames_to_pop_failed_realloc frames, the ones that reference
 974   // failed reallocations.
 975   int _frames_to_pop_failed_realloc;
 976 
 977 #ifndef PRODUCT
 978   int _jmp_ring_index;
 979   struct {
 980     // We use intptr_t instead of address so debugger doesn't try and display strings
 981     intptr_t _target;
 982     intptr_t _instruction;
 983     const char*  _file;
 984     int _line;
 985   }   _jmp_ring[jump_ring_buffer_size];
 986 #endif // PRODUCT
 987 
 988 #if INCLUDE_ALL_GCS
 989   // Support for G1 barriers
 990 
 991   ObjPtrQueue _satb_mark_queue;          // Thread-local log for SATB barrier.
 992   // Set of all such queues.
 993   static SATBMarkQueueSet _satb_mark_queue_set;
 994 
 995   DirtyCardQueue _dirty_card_queue;      // Thread-local log for dirty cards.
 996   // Set of all such queues.
 997   static DirtyCardQueueSet _dirty_card_queue_set;
 998 
 999   void flush_barrier_queues();
1000 #endif // INCLUDE_ALL_GCS
1001 
1002   friend class VMThread;
1003   friend class ThreadWaitTransition;
1004   friend class VM_Exit;
1005 
1006   void initialize();                             // Initialized the instance variables
1007 
1008  public:
1009   // Constructor
1010   JavaThread(bool is_attaching_via_jni = false); // for main thread and JNI attached threads
1011   JavaThread(ThreadFunction entry_point, size_t stack_size = 0);
1012   ~JavaThread();
1013 
1014 #ifdef ASSERT
1015   // verify this JavaThread hasn't be published in the Threads::list yet
1016   void verify_not_published();
1017 #endif
1018 
1019   //JNI functiontable getter/setter for JVMTI jni function table interception API.
1020   void set_jni_functions(struct JNINativeInterface_* functionTable) {
1021     _jni_environment.functions = functionTable;
1022   }
1023   struct JNINativeInterface_* get_jni_functions() {
1024     return (struct JNINativeInterface_ *)_jni_environment.functions;
1025   }
1026 
1027   // This function is called at thread creation to allow
1028   // platform specific thread variables to be initialized.
1029   void cache_global_variables();
1030 
1031   // Executes Shutdown.shutdown()
1032   void invoke_shutdown_hooks();
1033 
1034   // Cleanup on thread exit
1035   enum ExitType {
1036     normal_exit,
1037     jni_detach
1038   };
1039   void exit(bool destroy_vm, ExitType exit_type = normal_exit);
1040 
1041   void cleanup_failed_attach_current_thread();
1042 
1043   // Testers
1044   virtual bool is_Java_thread() const            { return true;  }
1045   virtual bool can_call_java() const             { return true; }
1046 
1047   // Thread chain operations
1048   JavaThread* next() const                       { return _next; }
1049   void set_next(JavaThread* p)                   { _next = p; }
1050 
1051   // Thread oop. threadObj() can be NULL for initial JavaThread
1052   // (or for threads attached via JNI)
1053   oop threadObj() const                          { return _threadObj; }
1054   void set_threadObj(oop p)                      { _threadObj = p; }
1055 
1056   ThreadPriority java_priority() const;          // Read from threadObj()
1057 
1058   // Prepare thread and add to priority queue.  If a priority is
1059   // not specified, use the priority of the thread object. Threads_lock
1060   // must be held while this function is called.
1061   void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
1062   void prepare_ext();
1063 
1064   void set_saved_exception_pc(address pc)        { _saved_exception_pc = pc; }
1065   address saved_exception_pc()                   { return _saved_exception_pc; }
1066 
1067 
1068   ThreadFunction entry_point() const             { return _entry_point; }
1069 
1070   // Allocates a new Java level thread object for this thread. thread_name may be NULL.
1071   void allocate_threadObj(Handle thread_group, const char* thread_name, bool daemon, TRAPS);
1072 
1073   // Last frame anchor routines
1074 
1075   JavaFrameAnchor* frame_anchor(void)            { return &_anchor; }
1076 
1077   // last_Java_sp
1078   bool has_last_Java_frame() const               { return _anchor.has_last_Java_frame(); }
1079   intptr_t* last_Java_sp() const                 { return _anchor.last_Java_sp(); }
1080 
1081   // last_Java_pc
1082 
1083   address last_Java_pc(void)                     { return _anchor.last_Java_pc(); }
1084 
1085   // Safepoint support
1086 #if !(defined(PPC64) || defined(AARCH64))
1087   JavaThreadState thread_state() const           { return _thread_state; }
1088   void set_thread_state(JavaThreadState s)       { _thread_state = s;    }
1089 #else
1090   // Use membars when accessing volatile _thread_state. See
1091   // Threads::create_vm() for size checks.
1092   inline JavaThreadState thread_state() const;
1093   inline void set_thread_state(JavaThreadState s);
1094 #endif
1095   ThreadSafepointState *safepoint_state() const  { return _safepoint_state; }
1096   void set_safepoint_state(ThreadSafepointState *state) { _safepoint_state = state; }
1097   bool is_at_poll_safepoint()                    { return _safepoint_state->is_at_poll_safepoint(); }
1098 
1099   // thread has called JavaThread::exit() or is terminated
1100   bool is_exiting()                              { return _terminated == _thread_exiting || is_terminated(); }
1101   // thread is terminated (no longer on the threads list); we compare
1102   // against the two non-terminated values so that a freed JavaThread
1103   // will also be considered terminated.
1104   bool is_terminated()                           { return _terminated != _not_terminated && _terminated != _thread_exiting; }
1105   void set_terminated(TerminatedTypes t)         { _terminated = t; }
1106   // special for Threads::remove() which is static:
1107   void set_terminated_value()                    { _terminated = _thread_terminated; }
1108   void block_if_vm_exited();
1109 
1110   bool doing_unsafe_access()                     { return _doing_unsafe_access; }
1111   void set_doing_unsafe_access(bool val)         { _doing_unsafe_access = val; }
1112 
1113   bool do_not_unlock_if_synchronized()             { return _do_not_unlock_if_synchronized; }
1114   void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
1115 
1116   // Suspend/resume support for JavaThread
1117  private:
1118   inline void set_ext_suspended();
1119   inline void clear_ext_suspended();
1120 
1121  public:
1122   void java_suspend();
1123   void java_resume();
1124   int  java_suspend_self();
1125 
1126   void check_and_wait_while_suspended() {
1127     assert(JavaThread::current() == this, "sanity check");
1128 
1129     bool do_self_suspend;
1130     do {
1131       // were we externally suspended while we were waiting?
1132       do_self_suspend = handle_special_suspend_equivalent_condition();
1133       if (do_self_suspend) {
1134         // don't surprise the thread that suspended us by returning
1135         java_suspend_self();
1136         set_suspend_equivalent();
1137       }
1138     } while (do_self_suspend);
1139   }
1140   static void check_safepoint_and_suspend_for_native_trans(JavaThread *thread);
1141   // Check for async exception in addition to safepoint and suspend request.
1142   static void check_special_condition_for_native_trans(JavaThread *thread);
1143 
1144   // Same as check_special_condition_for_native_trans but finishes the
1145   // transition into thread_in_Java mode so that it can potentially
1146   // block.
1147   static void check_special_condition_for_native_trans_and_transition(JavaThread *thread);
1148 
1149   bool is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits);
1150   bool is_ext_suspend_completed_with_lock(uint32_t *bits) {
1151     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1152     // Warning: is_ext_suspend_completed() may temporarily drop the
1153     // SR_lock to allow the thread to reach a stable thread state if
1154     // it is currently in a transient thread state.
1155     return is_ext_suspend_completed(false /* !called_by_wait */,
1156                                     SuspendRetryDelay, bits);
1157   }
1158 
1159   // We cannot allow wait_for_ext_suspend_completion() to run forever or
1160   // we could hang. SuspendRetryCount and SuspendRetryDelay are normally
1161   // passed as the count and delay parameters. Experiments with specific
1162   // calls to wait_for_ext_suspend_completion() can be done by passing
1163   // other values in the code. Experiments with all calls can be done
1164   // via the appropriate -XX options.
1165   bool wait_for_ext_suspend_completion(int count, int delay, uint32_t *bits);
1166 
1167   inline void set_external_suspend();
1168   inline void clear_external_suspend();
1169 
1170   inline void set_deopt_suspend();
1171   inline void clear_deopt_suspend();
1172   bool is_deopt_suspend()         { return (_suspend_flags & _deopt_suspend) != 0; }
1173 
1174   bool is_external_suspend() const {
1175     return (_suspend_flags & _external_suspend) != 0;
1176   }
1177   // Whenever a thread transitions from native to vm/java it must suspend
1178   // if external|deopt suspend is present.
1179   bool is_suspend_after_native() const {
1180     return (_suspend_flags & (_external_suspend | _deopt_suspend)) != 0;
1181   }
1182 
1183   // external suspend request is completed
1184   bool is_ext_suspended() const {
1185     return (_suspend_flags & _ext_suspended) != 0;
1186   }
1187 
1188   bool is_external_suspend_with_lock() const {
1189     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1190     return is_external_suspend();
1191   }
1192 
1193   // Special method to handle a pending external suspend request
1194   // when a suspend equivalent condition lifts.
1195   bool handle_special_suspend_equivalent_condition() {
1196     assert(is_suspend_equivalent(),
1197            "should only be called in a suspend equivalence condition");
1198     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1199     bool ret = is_external_suspend();
1200     if (!ret) {
1201       // not about to self-suspend so clear suspend equivalence
1202       clear_suspend_equivalent();
1203     }
1204     // implied else:
1205     // We have a pending external suspend request so we leave the
1206     // suspend_equivalent flag set until java_suspend_self() sets
1207     // the ext_suspended flag and clears the suspend_equivalent
1208     // flag. This insures that wait_for_ext_suspend_completion()
1209     // will return consistent values.
1210     return ret;
1211   }
1212 
1213   // utility methods to see if we are doing some kind of suspension
1214   bool is_being_ext_suspended() const            {
1215     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1216     return is_ext_suspended() || is_external_suspend();
1217   }
1218 
1219   bool is_suspend_equivalent() const             { return _suspend_equivalent; }
1220 
1221   void set_suspend_equivalent()                  { _suspend_equivalent = true; }
1222   void clear_suspend_equivalent()                { _suspend_equivalent = false; }
1223 
1224   // Thread.stop support
1225   void send_thread_stop(oop throwable);
1226   AsyncRequests clear_special_runtime_exit_condition() {
1227     AsyncRequests x = _special_runtime_exit_condition;
1228     _special_runtime_exit_condition = _no_async_condition;
1229     return x;
1230   }
1231 
1232   // Are any async conditions present?
1233   bool has_async_condition() { return (_special_runtime_exit_condition != _no_async_condition); }
1234 
1235   void check_and_handle_async_exceptions(bool check_unsafe_error = true);
1236 
1237   // these next two are also used for self-suspension and async exception support
1238   void handle_special_runtime_exit_condition(bool check_asyncs = true);
1239 
1240   // Return true if JavaThread has an asynchronous condition or
1241   // if external suspension is requested.
1242   bool has_special_runtime_exit_condition() {
1243     // We call is_external_suspend() last since external suspend should
1244     // be less common. Because we don't use is_external_suspend_with_lock
1245     // it is possible that we won't see an asynchronous external suspend
1246     // request that has just gotten started, i.e., SR_lock grabbed but
1247     // _external_suspend field change either not made yet or not visible
1248     // yet. However, this is okay because the request is asynchronous and
1249     // we will see the new flag value the next time through. It's also
1250     // possible that the external suspend request is dropped after
1251     // we have checked is_external_suspend(), we will recheck its value
1252     // under SR_lock in java_suspend_self().
1253     return (_special_runtime_exit_condition != _no_async_condition) ||
1254             is_external_suspend() || is_deopt_suspend();
1255   }
1256 
1257   void set_pending_unsafe_access_error()          { _special_runtime_exit_condition = _async_unsafe_access_error; }
1258 
1259   inline void set_pending_async_exception(oop e);
1260 
1261   // Fast-locking support
1262   bool is_lock_owned(address adr) const;
1263 
1264   // Accessors for vframe array top
1265   // The linked list of vframe arrays are sorted on sp. This means when we
1266   // unpack the head must contain the vframe array to unpack.
1267   void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
1268   vframeArray* vframe_array_head() const         { return _vframe_array_head;  }
1269 
1270   // Side structure for deferring update of java frame locals until deopt occurs
1271   GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred_locals() const { return _deferred_locals_updates; }
1272   void set_deferred_locals(GrowableArray<jvmtiDeferredLocalVariableSet *>* vf) { _deferred_locals_updates = vf; }
1273 
1274   // These only really exist to make debugging deopt problems simpler
1275 
1276   void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
1277   vframeArray* vframe_array_last() const         { return _vframe_array_last;  }
1278 
1279   // The special resourceMark used during deoptimization
1280 
1281   void set_deopt_mark(DeoptResourceMark* value)  { _deopt_mark = value; }
1282   DeoptResourceMark* deopt_mark(void)            { return _deopt_mark; }
1283 
1284   intptr_t* must_deopt_id()                      { return _must_deopt_id; }
1285   void     set_must_deopt_id(intptr_t* id)       { _must_deopt_id = id; }
1286   void     clear_must_deopt_id()                 { _must_deopt_id = NULL; }
1287 
1288   void set_deopt_nmethod(nmethod* nm)            { _deopt_nmethod = nm;   }
1289   nmethod* deopt_nmethod()                       { return _deopt_nmethod; }
1290 
1291   Method*    callee_target() const               { return _callee_target; }
1292   void set_callee_target  (Method* x)          { _callee_target   = x; }
1293 
1294   // Oop results of vm runtime calls
1295   oop  vm_result() const                         { return _vm_result; }
1296   void set_vm_result  (oop x)                    { _vm_result   = x; }
1297 
1298   Metadata*    vm_result_2() const               { return _vm_result_2; }
1299   void set_vm_result_2  (Metadata* x)          { _vm_result_2   = x; }
1300 
1301   MemRegion deferred_card_mark() const           { return _deferred_card_mark; }
1302   void set_deferred_card_mark(MemRegion mr)      { _deferred_card_mark = mr;   }
1303 
1304 #if INCLUDE_JVMCI
1305   int  pending_deoptimization() const             { return _pending_deoptimization; }
1306   oop  pending_failed_speculation() const         { return _pending_failed_speculation; }
1307   bool has_pending_monitorenter() const           { return _pending_monitorenter; }
1308   void set_pending_monitorenter(bool b)           { _pending_monitorenter = b; }
1309   void set_pending_deoptimization(int reason)     { _pending_deoptimization = reason; }
1310   void set_pending_failed_speculation(oop failed_speculation) { _pending_failed_speculation = failed_speculation; }
1311   void set_pending_transfer_to_interpreter(bool b) { _pending_transfer_to_interpreter = b; }
1312   void set_jvmci_alternate_call_target(address a) { assert(_jvmci._alternate_call_target == NULL, "must be"); _jvmci._alternate_call_target = a; }
1313   void set_jvmci_implicit_exception_pc(address a) { assert(_jvmci._implicit_exception_pc == NULL, "must be"); _jvmci._implicit_exception_pc = a; }
1314 #endif // INCLUDE_JVMCI
1315 
1316   // Exception handling for compiled methods
1317   oop      exception_oop() const                 { return _exception_oop; }
1318   address  exception_pc() const                  { return _exception_pc; }
1319   address  exception_handler_pc() const          { return _exception_handler_pc; }
1320   bool     is_method_handle_return() const       { return _is_method_handle_return == 1; }
1321 
1322   void set_exception_oop(oop o)                  { (void)const_cast<oop&>(_exception_oop = o); }
1323   void set_exception_pc(address a)               { _exception_pc = a; }
1324   void set_exception_handler_pc(address a)       { _exception_handler_pc = a; }
1325   void set_is_method_handle_return(bool value)   { _is_method_handle_return = value ? 1 : 0; }
1326 
1327   void clear_exception_oop_and_pc() {
1328     set_exception_oop(NULL);
1329     set_exception_pc(NULL);
1330   }
1331 
1332   // Stack overflow support
1333   inline size_t stack_available(address cur_sp);
1334   address stack_yellow_zone_base() {
1335     return (address)(stack_base() -
1336                      (stack_size() -
1337                      (stack_red_zone_size() + stack_yellow_zone_size())));
1338   }
1339   size_t  stack_yellow_zone_size() {
1340     return StackYellowPages * os::vm_page_size();
1341   }
1342   address stack_red_zone_base() {
1343     return (address)(stack_base() - (stack_size() - stack_red_zone_size()));
1344   }
1345   size_t stack_red_zone_size() { return StackRedPages * os::vm_page_size(); }
1346   bool in_stack_yellow_zone(address a) {
1347     return (a <= stack_yellow_zone_base()) && (a >= stack_red_zone_base());
1348   }
1349   bool in_stack_red_zone(address a) {
1350     return (a <= stack_red_zone_base()) &&
1351            (a >= (address)((intptr_t)stack_base() - stack_size()));
1352   }
1353 
1354   void create_stack_guard_pages();
1355   void remove_stack_guard_pages();
1356 
1357   void enable_stack_yellow_zone();
1358   void disable_stack_yellow_zone();
1359   void enable_stack_red_zone();
1360   void disable_stack_red_zone();
1361 
1362   inline bool stack_guard_zone_unused();
1363   inline bool stack_yellow_zone_disabled();
1364   inline bool stack_yellow_zone_enabled();
1365 
1366   // Attempt to reguard the stack after a stack overflow may have occurred.
1367   // Returns true if (a) guard pages are not needed on this thread, (b) the
1368   // pages are already guarded, or (c) the pages were successfully reguarded.
1369   // Returns false if there is not enough stack space to reguard the pages, in
1370   // which case the caller should unwind a frame and try again.  The argument
1371   // should be the caller's (approximate) sp.
1372   bool reguard_stack(address cur_sp);
1373   // Similar to above but see if current stackpoint is out of the guard area
1374   // and reguard if possible.
1375   bool reguard_stack(void);
1376 
1377   address stack_overflow_limit() { return _stack_overflow_limit; }
1378   void set_stack_overflow_limit() {
1379     _stack_overflow_limit = _stack_base - _stack_size +
1380                             ((StackShadowPages +
1381                               StackYellowPages +
1382                               StackRedPages) * os::vm_page_size());
1383   }
1384 
1385   // Misc. accessors/mutators
1386   void set_do_not_unlock(void)                   { _do_not_unlock_if_synchronized = true; }
1387   void clr_do_not_unlock(void)                   { _do_not_unlock_if_synchronized = false; }
1388   bool do_not_unlock(void)                       { return _do_not_unlock_if_synchronized; }
1389 
1390 #ifndef PRODUCT
1391   void record_jump(address target, address instr, const char* file, int line);
1392 #endif // PRODUCT
1393 
1394   // For assembly stub generation
1395   static ByteSize threadObj_offset()             { return byte_offset_of(JavaThread, _threadObj); }
1396 #ifndef PRODUCT
1397   static ByteSize jmp_ring_index_offset()        { return byte_offset_of(JavaThread, _jmp_ring_index); }
1398   static ByteSize jmp_ring_offset()              { return byte_offset_of(JavaThread, _jmp_ring); }
1399 #endif // PRODUCT
1400   static ByteSize jni_environment_offset()       { return byte_offset_of(JavaThread, _jni_environment); }
1401   static ByteSize last_Java_sp_offset() {
1402     return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
1403   }
1404   static ByteSize last_Java_pc_offset() {
1405     return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
1406   }
1407   static ByteSize frame_anchor_offset() {
1408     return byte_offset_of(JavaThread, _anchor);
1409   }
1410   static ByteSize callee_target_offset()         { return byte_offset_of(JavaThread, _callee_target); }
1411   static ByteSize vm_result_offset()             { return byte_offset_of(JavaThread, _vm_result); }
1412   static ByteSize vm_result_2_offset()           { return byte_offset_of(JavaThread, _vm_result_2); }
1413   static ByteSize thread_state_offset()          { return byte_offset_of(JavaThread, _thread_state); }
1414   static ByteSize saved_exception_pc_offset()    { return byte_offset_of(JavaThread, _saved_exception_pc); }
1415   static ByteSize osthread_offset()              { return byte_offset_of(JavaThread, _osthread); }
1416 #if INCLUDE_JVMCI
1417   static ByteSize pending_deoptimization_offset() { return byte_offset_of(JavaThread, _pending_deoptimization); }
1418   static ByteSize pending_monitorenter_offset()  { return byte_offset_of(JavaThread, _pending_monitorenter); }
1419   static ByteSize pending_failed_speculation_offset() { return byte_offset_of(JavaThread, _pending_failed_speculation); }
1420   static ByteSize jvmci_alternate_call_target_offset() { return byte_offset_of(JavaThread, _jvmci._alternate_call_target); }
1421   static ByteSize jvmci_implicit_exception_pc_offset() { return byte_offset_of(JavaThread, _jvmci._implicit_exception_pc); }
1422   static ByteSize jvmci_counters_offset()        { return byte_offset_of(JavaThread, _jvmci_counters); }
1423 #endif // INCLUDE_JVMCI
1424   static ByteSize exception_oop_offset()         { return byte_offset_of(JavaThread, _exception_oop); }
1425   static ByteSize exception_pc_offset()          { return byte_offset_of(JavaThread, _exception_pc); }
1426   static ByteSize exception_handler_pc_offset()  { return byte_offset_of(JavaThread, _exception_handler_pc); }
1427   static ByteSize stack_overflow_limit_offset()  { return byte_offset_of(JavaThread, _stack_overflow_limit); }
1428   static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); }
1429   static ByteSize stack_guard_state_offset()     { return byte_offset_of(JavaThread, _stack_guard_state); }
1430   static ByteSize suspend_flags_offset()         { return byte_offset_of(JavaThread, _suspend_flags); }
1431 
1432   static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
1433   static ByteSize should_post_on_exceptions_flag_offset() {
1434     return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
1435   }
1436 
1437 #if INCLUDE_ALL_GCS
1438   static ByteSize satb_mark_queue_offset()       { return byte_offset_of(JavaThread, _satb_mark_queue); }
1439   static ByteSize dirty_card_queue_offset()      { return byte_offset_of(JavaThread, _dirty_card_queue); }
1440 #endif // INCLUDE_ALL_GCS
1441 
1442   // Returns the jni environment for this thread
1443   JNIEnv* jni_environment()                      { return &_jni_environment; }
1444 
1445   static JavaThread* thread_from_jni_environment(JNIEnv* env) {
1446     JavaThread *thread_from_jni_env = (JavaThread*)((intptr_t)env - in_bytes(jni_environment_offset()));
1447     // Only return NULL if thread is off the thread list; starting to
1448     // exit should not return NULL.
1449     if (thread_from_jni_env->is_terminated()) {
1450       thread_from_jni_env->block_if_vm_exited();
1451       return NULL;
1452     } else {
1453       return thread_from_jni_env;
1454     }
1455   }
1456 
1457   // JNI critical regions. These can nest.
1458   bool in_critical()    { return _jni_active_critical > 0; }
1459   bool in_last_critical()  { return _jni_active_critical == 1; }
1460   void enter_critical() {
1461     assert(Thread::current() == this ||
1462            (Thread::current()->is_VM_thread() &&
1463            SafepointSynchronize::is_synchronizing()),
1464            "this must be current thread or synchronizing");
1465     _jni_active_critical++;
1466   }
1467   void exit_critical() {
1468     assert(Thread::current() == this, "this must be current thread");
1469     _jni_active_critical--;
1470     assert(_jni_active_critical >= 0, "JNI critical nesting problem?");
1471   }
1472 
1473   // Checked JNI, is the programmer required to check for exceptions, specify which function name
1474   bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != NULL; }
1475   void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = NULL; }
1476   const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; }
1477   void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; }
1478 
1479   // For deadlock detection
1480   int depth_first_number() { return _depth_first_number; }
1481   void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
1482 
1483  private:
1484   void set_monitor_chunks(MonitorChunk* monitor_chunks) { _monitor_chunks = monitor_chunks; }
1485 
1486  public:
1487   MonitorChunk* monitor_chunks() const           { return _monitor_chunks; }
1488   void add_monitor_chunk(MonitorChunk* chunk);
1489   void remove_monitor_chunk(MonitorChunk* chunk);
1490   bool in_deopt_handler() const                  { return _in_deopt_handler > 0; }
1491   void inc_in_deopt_handler()                    { _in_deopt_handler++; }
1492   void dec_in_deopt_handler() {
1493     assert(_in_deopt_handler > 0, "mismatched deopt nesting");
1494     if (_in_deopt_handler > 0) { // robustness
1495       _in_deopt_handler--;
1496     }
1497   }
1498 
1499  private:
1500   void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
1501 
1502  public:
1503 
1504   // Frame iteration; calls the function f for all frames on the stack
1505   void frames_do(void f(frame*, const RegisterMap*));
1506 
1507   // Memory operations
1508   void oops_do(OopClosure* f, CLDClosure* cld_f, CodeBlobClosure* cf);
1509 
1510   // Sweeper operations
1511   void nmethods_do(CodeBlobClosure* cf);
1512 
1513   // RedefineClasses Support
1514   void metadata_do(void f(Metadata*));
1515 
1516   // Misc. operations
1517   char* name() const { return (char*)get_thread_name(); }
1518   void print_on(outputStream* st) const;
1519   void print_value();
1520   void print_thread_state_on(outputStream*) const      PRODUCT_RETURN;
1521   void print_thread_state() const                      PRODUCT_RETURN;
1522   void print_on_error(outputStream* st, char* buf, int buflen) const;
1523   void verify();
1524   const char* get_thread_name() const;
1525  private:
1526   // factor out low-level mechanics for use in both normal and error cases
1527   const char* get_thread_name_string(char* buf = NULL, int buflen = 0) const;
1528  public:
1529   const char* get_threadgroup_name() const;
1530   const char* get_parent_name() const;
1531 
1532   // Accessing frames
1533   frame last_frame() {
1534     _anchor.make_walkable(this);
1535     return pd_last_frame();
1536   }
1537   javaVFrame* last_java_vframe(RegisterMap* reg_map);
1538 
1539   // Returns method at 'depth' java or native frames down the stack
1540   // Used for security checks
1541   Klass* security_get_caller_class(int depth);
1542 
1543   // Print stack trace in external format
1544   void print_stack_on(outputStream* st);
1545   void print_stack() { print_stack_on(tty); }
1546 
1547   // Print stack traces in various internal formats
1548   void trace_stack()                             PRODUCT_RETURN;
1549   void trace_stack_from(vframe* start_vf)        PRODUCT_RETURN;
1550   void trace_frames()                            PRODUCT_RETURN;
1551   void trace_oops()                              PRODUCT_RETURN;
1552 
1553   // Print an annotated view of the stack frames
1554   void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN;
1555   void validate_frame_layout() {
1556     print_frame_layout(0, true);
1557   }
1558 
1559   // Returns the number of stack frames on the stack
1560   int depth() const;
1561 
1562   // Function for testing deoptimization
1563   void deoptimize();
1564   void make_zombies();
1565 
1566   void deoptimized_wrt_marked_nmethods();
1567 
1568   // Profiling operation (see fprofile.cpp)
1569  public:
1570   bool profile_last_Java_frame(frame* fr);
1571 
1572  private:
1573   ThreadProfiler* _thread_profiler;
1574  private:
1575   friend class FlatProfiler;                    // uses both [gs]et_thread_profiler.
1576   friend class FlatProfilerTask;                // uses get_thread_profiler.
1577   friend class ThreadProfilerMark;              // uses get_thread_profiler.
1578   ThreadProfiler* get_thread_profiler()         { return _thread_profiler; }
1579   ThreadProfiler* set_thread_profiler(ThreadProfiler* tp) {
1580     ThreadProfiler* result = _thread_profiler;
1581     _thread_profiler = tp;
1582     return result;
1583   }
1584 
1585  public:
1586   // Returns the running thread as a JavaThread
1587   static inline JavaThread* current();
1588 
1589   // Returns the active Java thread.  Do not use this if you know you are calling
1590   // from a JavaThread, as it's slower than JavaThread::current.  If called from
1591   // the VMThread, it also returns the JavaThread that instigated the VMThread's
1592   // operation.  You may not want that either.
1593   static JavaThread* active();
1594 
1595   inline CompilerThread* as_CompilerThread();
1596 
1597  public:
1598   virtual void run();
1599   void thread_main_inner();
1600 
1601  private:
1602   // PRIVILEGED STACK
1603   PrivilegedElement*  _privileged_stack_top;
1604   GrowableArray<oop>* _array_for_gc;
1605  public:
1606 
1607   // Returns the privileged_stack information.
1608   PrivilegedElement* privileged_stack_top() const       { return _privileged_stack_top; }
1609   void set_privileged_stack_top(PrivilegedElement *e)   { _privileged_stack_top = e; }
1610   void register_array_for_gc(GrowableArray<oop>* array) { _array_for_gc = array; }
1611 
1612  public:
1613   // Thread local information maintained by JVMTI.
1614   void set_jvmti_thread_state(JvmtiThreadState *value)                           { _jvmti_thread_state = value; }
1615   // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1616   // getter is used to get this JavaThread's JvmtiThreadState if it has
1617   // one which means NULL can be returned. JvmtiThreadState::state_for()
1618   // is used to get the specified JavaThread's JvmtiThreadState if it has
1619   // one or it allocates a new JvmtiThreadState for the JavaThread and
1620   // returns it. JvmtiThreadState::state_for() will return NULL only if
1621   // the specified JavaThread is exiting.
1622   JvmtiThreadState *jvmti_thread_state() const                                   { return _jvmti_thread_state; }
1623   static ByteSize jvmti_thread_state_offset()                                    { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1624   void set_jvmti_get_loaded_classes_closure(JvmtiGetLoadedClassesClosure* value) { _jvmti_get_loaded_classes_closure = value; }
1625   JvmtiGetLoadedClassesClosure* get_jvmti_get_loaded_classes_closure() const     { return _jvmti_get_loaded_classes_closure; }
1626 
1627   // JVMTI PopFrame support
1628   // Setting and clearing popframe_condition
1629   // All of these enumerated values are bits. popframe_pending
1630   // indicates that a PopFrame() has been requested and not yet been
1631   // completed. popframe_processing indicates that that PopFrame() is in
1632   // the process of being completed. popframe_force_deopt_reexecution_bit
1633   // indicates that special handling is required when returning to a
1634   // deoptimized caller.
1635   enum PopCondition {
1636     popframe_inactive                      = 0x00,
1637     popframe_pending_bit                   = 0x01,
1638     popframe_processing_bit                = 0x02,
1639     popframe_force_deopt_reexecution_bit   = 0x04
1640   };
1641   PopCondition popframe_condition()                   { return (PopCondition) _popframe_condition; }
1642   void set_popframe_condition(PopCondition c)         { _popframe_condition = c; }
1643   void set_popframe_condition_bit(PopCondition c)     { _popframe_condition |= c; }
1644   void clear_popframe_condition()                     { _popframe_condition = popframe_inactive; }
1645   static ByteSize popframe_condition_offset()         { return byte_offset_of(JavaThread, _popframe_condition); }
1646   bool has_pending_popframe()                         { return (popframe_condition() & popframe_pending_bit) != 0; }
1647   bool popframe_forcing_deopt_reexecution()           { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
1648   void clear_popframe_forcing_deopt_reexecution()     { _popframe_condition &= ~popframe_force_deopt_reexecution_bit; }
1649 #ifdef CC_INTERP
1650   bool pop_frame_pending(void)                        { return ((_popframe_condition & popframe_pending_bit) != 0); }
1651   void clr_pop_frame_pending(void)                    { _popframe_condition = popframe_inactive; }
1652   bool pop_frame_in_process(void)                     { return ((_popframe_condition & popframe_processing_bit) != 0); }
1653   void set_pop_frame_in_process(void)                 { _popframe_condition |= popframe_processing_bit; }
1654   void clr_pop_frame_in_process(void)                 { _popframe_condition &= ~popframe_processing_bit; }
1655 #endif
1656 
1657   int frames_to_pop_failed_realloc() const            { return _frames_to_pop_failed_realloc; }
1658   void set_frames_to_pop_failed_realloc(int nb)       { _frames_to_pop_failed_realloc = nb; }
1659   void dec_frames_to_pop_failed_realloc()             { _frames_to_pop_failed_realloc--; }
1660 
1661  private:
1662   // Saved incoming arguments to popped frame.
1663   // Used only when popped interpreted frame returns to deoptimized frame.
1664   void*    _popframe_preserved_args;
1665   int      _popframe_preserved_args_size;
1666 
1667  public:
1668   void  popframe_preserve_args(ByteSize size_in_bytes, void* start);
1669   void* popframe_preserved_args();
1670   ByteSize popframe_preserved_args_size();
1671   WordSize popframe_preserved_args_size_in_words();
1672   void  popframe_free_preserved_args();
1673 
1674 
1675  private:
1676   JvmtiThreadState *_jvmti_thread_state;
1677   JvmtiGetLoadedClassesClosure* _jvmti_get_loaded_classes_closure;
1678 
1679   // Used by the interpreter in fullspeed mode for frame pop, method
1680   // entry, method exit and single stepping support. This field is
1681   // only set to non-zero by the VM_EnterInterpOnlyMode VM operation.
1682   // It can be set to zero asynchronously (i.e., without a VM operation
1683   // or a lock) so we have to be very careful.
1684   int               _interp_only_mode;
1685 
1686  public:
1687   // used by the interpreter for fullspeed debugging support (see above)
1688   static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
1689   bool is_interp_only_mode()                { return (_interp_only_mode != 0); }
1690   int get_interp_only_mode()                { return _interp_only_mode; }
1691   void increment_interp_only_mode()         { ++_interp_only_mode; }
1692   void decrement_interp_only_mode()         { --_interp_only_mode; }
1693 
1694   // support for cached flag that indicates whether exceptions need to be posted for this thread
1695   // if this is false, we can avoid deoptimizing when events are thrown
1696   // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
1697  private:
1698   int    _should_post_on_exceptions_flag;
1699 
1700  public:
1701   int   should_post_on_exceptions_flag()  { return _should_post_on_exceptions_flag; }
1702   void  set_should_post_on_exceptions_flag(int val)  { _should_post_on_exceptions_flag = val; }
1703 
1704  private:
1705   ThreadStatistics *_thread_stat;
1706 
1707  public:
1708   ThreadStatistics* get_thread_stat() const    { return _thread_stat; }
1709 
1710   // Return a blocker object for which this thread is blocked parking.
1711   oop current_park_blocker();
1712 
1713  private:
1714   static size_t _stack_size_at_create;
1715 
1716  public:
1717   static inline size_t stack_size_at_create(void) {
1718     return _stack_size_at_create;
1719   }
1720   static inline void set_stack_size_at_create(size_t value) {
1721     _stack_size_at_create = value;
1722   }
1723 
1724 #if INCLUDE_ALL_GCS
1725   // SATB marking queue support
1726   ObjPtrQueue& satb_mark_queue() { return _satb_mark_queue; }
1727   static SATBMarkQueueSet& satb_mark_queue_set() {
1728     return _satb_mark_queue_set;
1729   }
1730 
1731   // Dirty card queue support
1732   DirtyCardQueue& dirty_card_queue() { return _dirty_card_queue; }
1733   static DirtyCardQueueSet& dirty_card_queue_set() {
1734     return _dirty_card_queue_set;
1735   }
1736 #endif // INCLUDE_ALL_GCS
1737 
1738   // This method initializes the SATB and dirty card queues before a
1739   // JavaThread is added to the Java thread list. Right now, we don't
1740   // have to do anything to the dirty card queue (it should have been
1741   // activated when the thread was created), but we have to activate
1742   // the SATB queue if the thread is created while a marking cycle is
1743   // in progress. The activation / de-activation of the SATB queues at
1744   // the beginning / end of a marking cycle is done during safepoints
1745   // so we have to make sure this method is called outside one to be
1746   // able to safely read the active field of the SATB queue set. Right
1747   // now, it is called just before the thread is added to the Java
1748   // thread list in the Threads::add() method. That method is holding
1749   // the Threads_lock which ensures we are outside a safepoint. We
1750   // cannot do the obvious and set the active field of the SATB queue
1751   // when the thread is created given that, in some cases, safepoints
1752   // might happen between the JavaThread constructor being called and the
1753   // thread being added to the Java thread list (an example of this is
1754   // when the structure for the DestroyJavaVM thread is created).
1755 #if INCLUDE_ALL_GCS
1756   void initialize_queues();
1757 #else  // INCLUDE_ALL_GCS
1758   void initialize_queues() { }
1759 #endif // INCLUDE_ALL_GCS
1760 
1761   // Machine dependent stuff
1762 #ifdef TARGET_OS_ARCH_linux_x86
1763 # include "thread_linux_x86.hpp"
1764 #endif
1765 #ifdef TARGET_OS_ARCH_linux_sparc
1766 # include "thread_linux_sparc.hpp"
1767 #endif
1768 #ifdef TARGET_OS_ARCH_linux_zero
1769 # include "thread_linux_zero.hpp"
1770 #endif
1771 #ifdef TARGET_OS_ARCH_solaris_x86
1772 # include "thread_solaris_x86.hpp"
1773 #endif
1774 #ifdef TARGET_OS_ARCH_solaris_sparc
1775 # include "thread_solaris_sparc.hpp"
1776 #endif
1777 #ifdef TARGET_OS_ARCH_windows_x86
1778 # include "thread_windows_x86.hpp"
1779 #endif
1780 #ifdef TARGET_OS_ARCH_linux_arm
1781 # include "thread_linux_arm.hpp"
1782 #endif
1783 #ifdef TARGET_OS_ARCH_linux_ppc
1784 # include "thread_linux_ppc.hpp"
1785 #endif
1786 #ifdef TARGET_OS_ARCH_linux_aarch64
1787 # include "thread_linux_aarch64.hpp"
1788 #endif
1789 #ifdef TARGET_OS_ARCH_aix_ppc
1790 # include "thread_aix_ppc.hpp"
1791 #endif
1792 #ifdef TARGET_OS_ARCH_bsd_x86
1793 # include "thread_bsd_x86.hpp"
1794 #endif
1795 #ifdef TARGET_OS_ARCH_bsd_zero
1796 # include "thread_bsd_zero.hpp"
1797 #endif
1798 
1799 
1800  public:
1801   void set_blocked_on_compilation(bool value) {
1802     _blocked_on_compilation = value;
1803   }
1804 
1805   bool blocked_on_compilation() {
1806     return _blocked_on_compilation;
1807   }
1808  protected:
1809   bool         _blocked_on_compilation;
1810 
1811 
1812   // JSR166 per-thread parker
1813  private:
1814   Parker*    _parker;
1815  public:
1816   Parker*     parker() { return _parker; }
1817 
1818   // Biased locking support
1819  private:
1820   GrowableArray<MonitorInfo*>* _cached_monitor_info;
1821  public:
1822   GrowableArray<MonitorInfo*>* cached_monitor_info() { return _cached_monitor_info; }
1823   void set_cached_monitor_info(GrowableArray<MonitorInfo*>* info) { _cached_monitor_info = info; }
1824 
1825   // clearing/querying jni attach status
1826   bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; }
1827   bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
1828   inline void set_done_attaching_via_jni();
1829  private:
1830   // This field is used to determine if a thread has claimed
1831   // a par_id: it is UINT_MAX if the thread has not claimed a par_id;
1832   // otherwise its value is the par_id that has been claimed.
1833   uint _claimed_par_id;
1834  public:
1835   uint get_claimed_par_id() { return _claimed_par_id; }
1836   void set_claimed_par_id(uint id) { _claimed_par_id = id; }
1837 };
1838 
1839 // Inline implementation of JavaThread::current
1840 inline JavaThread* JavaThread::current() {
1841   Thread* thread = ThreadLocalStorage::thread();
1842   assert(thread != NULL && thread->is_Java_thread(), "just checking");
1843   return (JavaThread*)thread;
1844 }
1845 
1846 inline CompilerThread* JavaThread::as_CompilerThread() {
1847   assert(is_Compiler_thread(), "just checking");
1848   return (CompilerThread*)this;
1849 }
1850 
1851 // Dedicated thread to sweep the code cache
1852 class CodeCacheSweeperThread : public JavaThread {
1853   nmethod*       _scanned_nmethod; // nmethod being scanned by the sweeper
1854  public:
1855   CodeCacheSweeperThread();
1856   // Track the nmethod currently being scanned by the sweeper
1857   void set_scanned_nmethod(nmethod* nm) {
1858     assert(_scanned_nmethod == NULL || nm == NULL, "should reset to NULL before writing a new value");
1859     _scanned_nmethod = nm;
1860   }
1861 
1862   // Hide sweeper thread from external view.
1863   bool is_hidden_from_external_view() const { return true; }
1864 
1865   bool is_Code_cache_sweeper_thread() const { return true; }
1866   // GC support
1867   // Apply "f->do_oop" to all root oops in "this".
1868   // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames
1869   void oops_do(OopClosure* f, CLDClosure* cld_f, CodeBlobClosure* cf);
1870 };
1871 
1872 // A thread used for Compilation.
1873 class CompilerThread : public JavaThread {
1874   friend class VMStructs;
1875  private:
1876   CompilerCounters* _counters;
1877 
1878   ciEnv*            _env;
1879   CompileLog*       _log;
1880   CompileTask*      _task;
1881   CompileQueue*     _queue;
1882   BufferBlob*       _buffer_blob;
1883 
1884   AbstractCompiler* _compiler;
1885 
1886  public:
1887 
1888   static CompilerThread* current();
1889 
1890   CompilerThread(CompileQueue* queue, CompilerCounters* counters);
1891 
1892   bool is_Compiler_thread() const                { return true; }
1893 
1894   virtual bool can_call_java() const;
1895 
1896   // Hide native compiler threads from external view.
1897   bool is_hidden_from_external_view() const      { return !can_call_java(); }
1898 
1899   void set_compiler(AbstractCompiler* c)         { _compiler = c; }
1900   AbstractCompiler* compiler() const             { return _compiler; }
1901 
1902   CompileQueue* queue()        const             { return _queue; }
1903   CompilerCounters* counters() const             { return _counters; }
1904 
1905   // Get/set the thread's compilation environment.
1906   ciEnv*        env()                            { return _env; }
1907   void          set_env(ciEnv* env)              { _env = env; }
1908 
1909   BufferBlob*   get_buffer_blob() const          { return _buffer_blob; }
1910   void          set_buffer_blob(BufferBlob* b)   { _buffer_blob = b; }
1911 
1912   // Get/set the thread's logging information
1913   CompileLog*   log()                            { return _log; }
1914   void          init_log(CompileLog* log) {
1915     // Set once, for good.
1916     assert(_log == NULL, "set only once");
1917     _log = log;
1918   }
1919 
1920 #ifndef PRODUCT
1921  private:
1922   IdealGraphPrinter *_ideal_graph_printer;
1923  public:
1924   IdealGraphPrinter *ideal_graph_printer()           { return _ideal_graph_printer; }
1925   void set_ideal_graph_printer(IdealGraphPrinter *n) { _ideal_graph_printer = n; }
1926 #endif
1927 
1928   // Get/set the thread's current task
1929   CompileTask* task()                      { return _task; }
1930   void         set_task(CompileTask* task) { _task = task; }
1931 };
1932 
1933 inline CompilerThread* CompilerThread::current() {
1934   return JavaThread::current()->as_CompilerThread();
1935 }
1936 
1937 // The active thread queue. It also keeps track of the current used
1938 // thread priorities.
1939 class Threads: AllStatic {
1940   friend class VMStructs;
1941  private:
1942   static JavaThread* _thread_list;
1943   static int         _number_of_threads;
1944   static int         _number_of_non_daemon_threads;
1945   static int         _return_code;
1946   static int         _thread_claim_parity;
1947 #ifdef ASSERT
1948   static bool        _vm_complete;
1949 #endif
1950 
1951   static void initialize_java_lang_classes(JavaThread* main_thread, TRAPS);
1952   static void initialize_jsr292_core_classes(TRAPS);
1953  public:
1954   // Thread management
1955   // force_daemon is a concession to JNI, where we may need to add a
1956   // thread to the thread list before allocating its thread object
1957   static void add(JavaThread* p, bool force_daemon = false);
1958   static void remove(JavaThread* p);
1959   static bool includes(JavaThread* p);
1960   static JavaThread* first()                     { return _thread_list; }
1961   static void threads_do(ThreadClosure* tc);
1962 
1963   // Initializes the vm and creates the vm thread
1964   static jint create_vm(JavaVMInitArgs* args, bool* canTryAgain);
1965   static void convert_vm_init_libraries_to_agents();
1966   static void create_vm_init_libraries();
1967   static void create_vm_init_agents();
1968   static void shutdown_vm_agents();
1969   static bool destroy_vm();
1970   // Supported VM versions via JNI
1971   // Includes JNI_VERSION_1_1
1972   static jboolean is_supported_jni_version_including_1_1(jint version);
1973   // Does not include JNI_VERSION_1_1
1974   static jboolean is_supported_jni_version(jint version);
1975 
1976   // The "thread claim parity" provides a way for threads to be claimed
1977   // by parallel worker tasks.
1978   //
1979   // Each thread contains a a "parity" field. A task will claim the
1980   // thread only if its parity field is the same as the global parity,
1981   // which is updated by calling change_thread_claim_parity().
1982   //
1983   // For this to work change_thread_claim_parity() needs to be called
1984   // exactly once in sequential code before starting parallel tasks
1985   // that should claim threads.
1986   //
1987   // New threads get their parity set to 0 and change_thread_claim_parity()
1988   // never set the global parity to 0.
1989   static int thread_claim_parity() { return _thread_claim_parity; }
1990   static void change_thread_claim_parity();
1991   static void assert_all_threads_claimed() NOT_DEBUG_RETURN;
1992 
1993   // Apply "f->do_oop" to all root oops in all threads.
1994   // This version may only be called by sequential code.
1995   static void oops_do(OopClosure* f, CLDClosure* cld_f, CodeBlobClosure* cf);
1996   // This version may be called by sequential or parallel code.
1997   static void possibly_parallel_oops_do(bool is_par, OopClosure* f, CLDClosure* cld_f, CodeBlobClosure* cf);
1998   // This creates a list of GCTasks, one per thread.
1999   static void create_thread_roots_tasks(GCTaskQueue* q);
2000   // This creates a list of GCTasks, one per thread, for marking objects.
2001   static void create_thread_roots_marking_tasks(GCTaskQueue* q);
2002 
2003   // Apply "f->do_oop" to roots in all threads that
2004   // are part of compiled frames
2005   static void compiled_frame_oops_do(OopClosure* f, CodeBlobClosure* cf);
2006 
2007   static void convert_hcode_pointers();
2008   static void restore_hcode_pointers();
2009 
2010   // Sweeper
2011   static void nmethods_do(CodeBlobClosure* cf);
2012 
2013   // RedefineClasses support
2014   static void metadata_do(void f(Metadata*));
2015   static void metadata_handles_do(void f(Metadata*));
2016 
2017 #ifdef ASSERT
2018   static bool is_vm_complete() { return _vm_complete; }
2019 #endif
2020 
2021   // Verification
2022   static void verify();
2023   static void print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks);
2024   static void print(bool print_stacks, bool internal_format) {
2025     // this function is only used by debug.cpp
2026     print_on(tty, print_stacks, internal_format, false /* no concurrent lock printed */);
2027   }
2028   static void print_on_error(outputStream* st, Thread* current, char* buf, int buflen);
2029 
2030   // Get Java threads that are waiting to enter a monitor. If doLock
2031   // is true, then Threads_lock is grabbed as needed. Otherwise, the
2032   // VM needs to be at a safepoint.
2033   static GrowableArray<JavaThread*>* get_pending_threads(int count,
2034                                                          address monitor, bool doLock);
2035 
2036   // Get owning Java thread from the monitor's owner field. If doLock
2037   // is true, then Threads_lock is grabbed as needed. Otherwise, the
2038   // VM needs to be at a safepoint.
2039   static JavaThread *owning_thread_from_monitor_owner(address owner,
2040                                                       bool doLock);
2041 
2042   // Number of threads on the active threads list
2043   static int number_of_threads()                 { return _number_of_threads; }
2044   // Number of non-daemon threads on the active threads list
2045   static int number_of_non_daemon_threads()      { return _number_of_non_daemon_threads; }
2046 
2047   // Deoptimizes all frames tied to marked nmethods
2048   static void deoptimized_wrt_marked_nmethods();
2049 
2050   static JavaThread* find_java_thread_from_java_tid(jlong java_tid);
2051 
2052 };
2053 
2054 
2055 // Thread iterator
2056 class ThreadClosure: public StackObj {
2057  public:
2058   virtual void do_thread(Thread* thread) = 0;
2059 };
2060 
2061 class SignalHandlerMark: public StackObj {
2062  private:
2063   Thread* _thread;
2064  public:
2065   SignalHandlerMark(Thread* t) {
2066     _thread = t;
2067     if (_thread) _thread->enter_signal_handler();
2068   }
2069   ~SignalHandlerMark() {
2070     if (_thread) _thread->leave_signal_handler();
2071     _thread = NULL;
2072   }
2073 };
2074 
2075 
2076 #endif // SHARE_VM_RUNTIME_THREAD_HPP