1 /*
   2  * Copyright (c) 1997, 2015, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_RUNTIME_THREAD_HPP
  26 #define SHARE_VM_RUNTIME_THREAD_HPP
  27 
  28 #include "memory/allocation.hpp"
  29 #include "memory/threadLocalAllocBuffer.hpp"
  30 #include "oops/oop.hpp"
  31 #include "prims/jni.h"
  32 #include "prims/jvmtiExport.hpp"
  33 #include "runtime/frame.hpp"
  34 #include "runtime/javaFrameAnchor.hpp"
  35 #include "runtime/jniHandles.hpp"
  36 #include "runtime/mutexLocker.hpp"
  37 #include "runtime/os.hpp"
  38 #include "runtime/osThread.hpp"
  39 #include "runtime/park.hpp"
  40 #include "runtime/safepoint.hpp"
  41 #include "runtime/stubRoutines.hpp"
  42 #include "runtime/threadLocalStorage.hpp"
  43 #include "runtime/thread_ext.hpp"
  44 #include "runtime/unhandledOops.hpp"
  45 #include "trace/traceBackend.hpp"
  46 #include "trace/traceMacros.hpp"
  47 #include "utilities/exceptions.hpp"
  48 #include "utilities/macros.hpp"
  49 #include "utilities/top.hpp"
  50 #if INCLUDE_ALL_GCS
  51 #include "gc_implementation/g1/dirtyCardQueue.hpp"
  52 #include "gc_implementation/g1/satbQueue.hpp"
  53 #endif // INCLUDE_ALL_GCS
  54 #ifdef ZERO
  55 #ifdef TARGET_ARCH_zero
  56 # include "stack_zero.hpp"
  57 #endif
  58 #endif
  59 
  60 class ThreadSafepointState;
  61 class ThreadProfiler;
  62 
  63 class JvmtiThreadState;
  64 class JvmtiGetLoadedClassesClosure;
  65 class ThreadStatistics;
  66 class ConcurrentLocksDump;
  67 class ParkEvent;
  68 class Parker;
  69 
  70 class ciEnv;
  71 class CompileThread;
  72 class CompileLog;
  73 class CompileTask;
  74 class CompileQueue;
  75 class CompilerCounters;
  76 class vframeArray;
  77 
  78 class DeoptResourceMark;
  79 class jvmtiDeferredLocalVariableSet;
  80 
  81 class GCTaskQueue;
  82 class ThreadClosure;
  83 class IdealGraphPrinter;
  84 
  85 class Metadata;
  86 template <class T, MEMFLAGS F> class ChunkedList;
  87 typedef ChunkedList<Metadata*, mtInternal> MetadataOnStackBuffer;
  88 
  89 DEBUG_ONLY(class ResourceMark;)
  90 
  91 class WorkerThread;
  92 
  93 // Class hierarchy
  94 // - Thread
  95 //   - NamedThread
  96 //     - VMThread
  97 //     - ConcurrentGCThread
  98 //     - WorkerThread
  99 //       - GangWorker
 100 //       - GCTaskThread
 101 //   - JavaThread
 102 //   - WatcherThread
 103 
 104 class Thread: public ThreadShadow {
 105   friend class VMStructs;
 106  private:
 107   // Exception handling
 108   // (Note: _pending_exception and friends are in ThreadShadow)
 109   //oop       _pending_exception;                // pending exception for current thread
 110   // const char* _exception_file;                   // file information for exception (debugging only)
 111   // int         _exception_line;                   // line information for exception (debugging only)
 112  protected:
 113   // Support for forcing alignment of thread objects for biased locking
 114   void*       _real_malloc_address;
 115  public:
 116   void* operator new(size_t size) throw() { return allocate(size, true); }
 117   void* operator new(size_t size, const std::nothrow_t& nothrow_constant) throw() {
 118     return allocate(size, false); }
 119   void  operator delete(void* p);
 120 
 121  protected:
 122   static void* allocate(size_t size, bool throw_excpt, MEMFLAGS flags = mtThread);
 123  private:
 124 
 125   // ***************************************************************
 126   // Suspend and resume support
 127   // ***************************************************************
 128   //
 129   // VM suspend/resume no longer exists - it was once used for various
 130   // things including safepoints but was deprecated and finally removed
 131   // in Java 7. Because VM suspension was considered "internal" Java-level
 132   // suspension was considered "external", and this legacy naming scheme
 133   // remains.
 134   //
 135   // External suspend/resume requests come from JVM_SuspendThread,
 136   // JVM_ResumeThread, JVMTI SuspendThread, and finally JVMTI
 137   // ResumeThread. External
 138   // suspend requests cause _external_suspend to be set and external
 139   // resume requests cause _external_suspend to be cleared.
 140   // External suspend requests do not nest on top of other external
 141   // suspend requests. The higher level APIs reject suspend requests
 142   // for already suspended threads.
 143   //
 144   // The external_suspend
 145   // flag is checked by has_special_runtime_exit_condition() and java thread
 146   // will self-suspend when handle_special_runtime_exit_condition() is
 147   // called. Most uses of the _thread_blocked state in JavaThreads are
 148   // considered the same as being externally suspended; if the blocking
 149   // condition lifts, the JavaThread will self-suspend. Other places
 150   // where VM checks for external_suspend include:
 151   //   + mutex granting (do not enter monitors when thread is suspended)
 152   //   + state transitions from _thread_in_native
 153   //
 154   // In general, java_suspend() does not wait for an external suspend
 155   // request to complete. When it returns, the only guarantee is that
 156   // the _external_suspend field is true.
 157   //
 158   // wait_for_ext_suspend_completion() is used to wait for an external
 159   // suspend request to complete. External suspend requests are usually
 160   // followed by some other interface call that requires the thread to
 161   // be quiescent, e.g., GetCallTrace(). By moving the "wait time" into
 162   // the interface that requires quiescence, we give the JavaThread a
 163   // chance to self-suspend before we need it to be quiescent. This
 164   // improves overall suspend/query performance.
 165   //
 166   // _suspend_flags controls the behavior of java_ suspend/resume.
 167   // It must be set under the protection of SR_lock. Read from the flag is
 168   // OK without SR_lock as long as the value is only used as a hint.
 169   // (e.g., check _external_suspend first without lock and then recheck
 170   // inside SR_lock and finish the suspension)
 171   //
 172   // _suspend_flags is also overloaded for other "special conditions" so
 173   // that a single check indicates whether any special action is needed
 174   // eg. for async exceptions.
 175   // -------------------------------------------------------------------
 176   // Notes:
 177   // 1. The suspend/resume logic no longer uses ThreadState in OSThread
 178   // but we still update its value to keep other part of the system (mainly
 179   // JVMTI) happy. ThreadState is legacy code (see notes in
 180   // osThread.hpp).
 181   //
 182   // 2. It would be more natural if set_external_suspend() is private and
 183   // part of java_suspend(), but that probably would affect the suspend/query
 184   // performance. Need more investigation on this.
 185 
 186   // suspend/resume lock: used for self-suspend
 187   Monitor* _SR_lock;
 188 
 189  protected:
 190   enum SuspendFlags {
 191     // NOTE: avoid using the sign-bit as cc generates different test code
 192     //       when the sign-bit is used, and sometimes incorrectly - see CR 6398077
 193 
 194     _external_suspend       = 0x20000000U, // thread is asked to self suspend
 195     _ext_suspended          = 0x40000000U, // thread has self-suspended
 196     _deopt_suspend          = 0x10000000U, // thread needs to self suspend for deopt
 197 
 198     _has_async_exception    = 0x00000001U, // there is a pending async exception
 199     _critical_native_unlock = 0x00000002U  // Must call back to unlock JNI critical lock
 200   };
 201 
 202   // various suspension related flags - atomically updated
 203   // overloaded for async exception checking in check_special_condition_for_native_trans.
 204   volatile uint32_t _suspend_flags;
 205 
 206  private:
 207   int _num_nested_signal;
 208 
 209   DEBUG_ONLY(bool _suspendible_thread;)
 210 
 211  public:
 212   void enter_signal_handler() { _num_nested_signal++; }
 213   void leave_signal_handler() { _num_nested_signal--; }
 214   bool is_inside_signal_handler() const { return _num_nested_signal > 0; }
 215 
 216 #ifdef ASSERT
 217   void set_suspendible_thread() {
 218     _suspendible_thread = true;
 219   }
 220 
 221   void clear_suspendible_thread() {
 222     _suspendible_thread = false;
 223   }
 224 
 225   bool is_suspendible_thread() { return _suspendible_thread; }
 226 #endif
 227 
 228  private:
 229   // Active_handles points to a block of handles
 230   JNIHandleBlock* _active_handles;
 231 
 232   // One-element thread local free list
 233   JNIHandleBlock* _free_handle_block;
 234 
 235   // Point to the last handle mark
 236   HandleMark* _last_handle_mark;
 237 
 238   // The parity of the last strong_roots iteration in which this thread was
 239   // claimed as a task.
 240   jint _oops_do_parity;
 241 
 242  public:
 243   void set_last_handle_mark(HandleMark* mark)   { _last_handle_mark = mark; }
 244   HandleMark* last_handle_mark() const          { return _last_handle_mark; }
 245  private:
 246 
 247   // debug support for checking if code does allow safepoints or not
 248   // GC points in the VM can happen because of allocation, invoking a VM operation, or blocking on
 249   // mutex, or blocking on an object synchronizer (Java locking).
 250   // If !allow_safepoint(), then an assertion failure will happen in any of the above cases
 251   // If !allow_allocation(), then an assertion failure will happen during allocation
 252   // (Hence, !allow_safepoint() => !allow_allocation()).
 253   //
 254   // The two classes No_Safepoint_Verifier and No_Allocation_Verifier are used to set these counters.
 255   //
 256   NOT_PRODUCT(int _allow_safepoint_count;)      // If 0, thread allow a safepoint to happen
 257   debug_only(int _allow_allocation_count;)     // If 0, the thread is allowed to allocate oops.
 258 
 259   // Used by SkipGCALot class.
 260   NOT_PRODUCT(bool _skip_gcalot;)               // Should we elide gc-a-lot?
 261 
 262   friend class No_Alloc_Verifier;
 263   friend class No_Safepoint_Verifier;
 264   friend class Pause_No_Safepoint_Verifier;
 265   friend class ThreadLocalStorage;
 266   friend class GC_locker;
 267 
 268   ThreadLocalAllocBuffer _tlab;                 // Thread-local eden
 269   jlong _allocated_bytes;                       // Cumulative number of bytes allocated on
 270                                                 // the Java heap
 271 
 272   TRACE_DATA _trace_data;                       // Thread-local data for tracing
 273 
 274   ThreadExt _ext;
 275 
 276   int   _vm_operation_started_count;            // VM_Operation support
 277   int   _vm_operation_completed_count;          // VM_Operation support
 278 
 279   ObjectMonitor* _current_pending_monitor;      // ObjectMonitor this thread
 280                                                 // is waiting to lock
 281   bool _current_pending_monitor_is_from_java;   // locking is from Java code
 282 
 283   // ObjectMonitor on which this thread called Object.wait()
 284   ObjectMonitor* _current_waiting_monitor;
 285 
 286   // Private thread-local objectmonitor list - a simple cache organized as a SLL.
 287  public:
 288   ObjectMonitor* omFreeList;
 289   int omFreeCount;                              // length of omFreeList
 290   int omFreeProvision;                          // reload chunk size
 291   ObjectMonitor* omInUseList;                   // SLL to track monitors in circulation
 292   int omInUseCount;                             // length of omInUseList
 293 
 294 #ifdef ASSERT
 295  private:
 296   bool _visited_for_critical_count;
 297 
 298  public:
 299   void set_visited_for_critical_count(bool z) { _visited_for_critical_count = z; }
 300   bool was_visited_for_critical_count() const   { return _visited_for_critical_count; }
 301 #endif
 302 
 303  public:
 304   enum {
 305     is_definitely_current_thread = true
 306   };
 307 
 308   // Constructor
 309   Thread();
 310   virtual ~Thread();
 311 
 312   // initializtion
 313   void initialize_thread_local_storage();
 314 
 315   // thread entry point
 316   virtual void run();
 317 
 318   // Testers
 319   virtual bool is_VM_thread()       const            { return false; }
 320   virtual bool is_Java_thread()     const            { return false; }
 321   virtual bool is_Compiler_thread() const            { return false; }
 322   virtual bool is_Code_cache_sweeper_thread() const  { return false; }
 323   virtual bool is_hidden_from_external_view() const  { return false; }
 324   virtual bool is_jvmti_agent_thread() const         { return false; }
 325   // True iff the thread can perform GC operations at a safepoint.
 326   // Generally will be true only of VM thread and parallel GC WorkGang
 327   // threads.
 328   virtual bool is_GC_task_thread() const             { return false; }
 329   virtual bool is_Watcher_thread() const             { return false; }
 330   virtual bool is_ConcurrentGC_thread() const        { return false; }
 331   virtual bool is_Named_thread() const               { return false; }
 332   virtual bool is_Worker_thread() const              { return false; }
 333 
 334   // Casts
 335   virtual WorkerThread* as_Worker_thread() const     { return NULL; }
 336 
 337   virtual char* name() const { return (char*)"Unknown thread"; }
 338 
 339   // Returns the current thread
 340   static inline Thread* current();
 341   // ... without having to include thread.inline.hpp.
 342   static Thread* current_noinline();
 343 
 344   // Common thread operations
 345   static void set_priority(Thread* thread, ThreadPriority priority);
 346   static ThreadPriority get_priority(const Thread* const thread);
 347   static void start(Thread* thread);
 348   static void interrupt(Thread* thr);
 349   static bool is_interrupted(Thread* thr, bool clear_interrupted);
 350 
 351   void set_native_thread_name(const char *name) {
 352     assert(Thread::current() == this, "set_native_thread_name can only be called on the current thread");
 353     os::set_native_thread_name(name);
 354   }
 355 
 356   ObjectMonitor** omInUseList_addr()             { return (ObjectMonitor **)&omInUseList; }
 357   Monitor* SR_lock() const                       { return _SR_lock; }
 358 
 359   bool has_async_exception() const { return (_suspend_flags & _has_async_exception) != 0; }
 360 
 361   inline void set_suspend_flag(SuspendFlags f);
 362   inline void clear_suspend_flag(SuspendFlags f);
 363 
 364   inline void set_has_async_exception();
 365   inline void clear_has_async_exception();
 366 
 367   bool do_critical_native_unlock() const { return (_suspend_flags & _critical_native_unlock) != 0; }
 368 
 369   inline void set_critical_native_unlock();
 370   inline void clear_critical_native_unlock();
 371 
 372   // Support for Unhandled Oop detection
 373 #ifdef CHECK_UNHANDLED_OOPS
 374  private:
 375   UnhandledOops* _unhandled_oops;
 376  public:
 377   UnhandledOops* unhandled_oops() { return _unhandled_oops; }
 378   // Mark oop safe for gc.  It may be stack allocated but won't move.
 379   void allow_unhandled_oop(oop *op) {
 380     if (CheckUnhandledOops) unhandled_oops()->allow_unhandled_oop(op);
 381   }
 382   // Clear oops at safepoint so crashes point to unhandled oop violator
 383   void clear_unhandled_oops() {
 384     if (CheckUnhandledOops) unhandled_oops()->clear_unhandled_oops();
 385   }
 386 #endif // CHECK_UNHANDLED_OOPS
 387 
 388 #ifndef PRODUCT
 389   bool skip_gcalot()           { return _skip_gcalot; }
 390   void set_skip_gcalot(bool v) { _skip_gcalot = v;    }
 391 #endif
 392 
 393  public:
 394   // Installs a pending exception to be inserted later
 395   static void send_async_exception(oop thread_oop, oop java_throwable);
 396 
 397   // Resource area
 398   ResourceArea* resource_area() const            { return _resource_area; }
 399   void set_resource_area(ResourceArea* area)     { _resource_area = area; }
 400 
 401   OSThread* osthread() const                     { return _osthread;   }
 402   void set_osthread(OSThread* thread)            { _osthread = thread; }
 403 
 404   // JNI handle support
 405   JNIHandleBlock* active_handles() const         { return _active_handles; }
 406   void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
 407   JNIHandleBlock* free_handle_block() const      { return _free_handle_block; }
 408   void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
 409 
 410   // Internal handle support
 411   HandleArea* handle_area() const                { return _handle_area; }
 412   void set_handle_area(HandleArea* area)         { _handle_area = area; }
 413 
 414   GrowableArray<Metadata*>* metadata_handles() const          { return _metadata_handles; }
 415   void set_metadata_handles(GrowableArray<Metadata*>* handles){ _metadata_handles = handles; }
 416 
 417   // Thread-Local Allocation Buffer (TLAB) support
 418   ThreadLocalAllocBuffer& tlab()                 { return _tlab; }
 419   void initialize_tlab() {
 420     if (UseTLAB) {
 421       tlab().initialize();
 422     }
 423   }
 424 
 425   jlong allocated_bytes()               { return _allocated_bytes; }
 426   void set_allocated_bytes(jlong value) { _allocated_bytes = value; }
 427   void incr_allocated_bytes(jlong size) { _allocated_bytes += size; }
 428   inline jlong cooked_allocated_bytes();
 429 
 430   TRACE_DATA* trace_data()              { return &_trace_data; }
 431 
 432   const ThreadExt& ext() const          { return _ext; }
 433   ThreadExt& ext()                      { return _ext; }
 434 
 435   // VM operation support
 436   int vm_operation_ticket()                      { return ++_vm_operation_started_count; }
 437   int vm_operation_completed_count()             { return _vm_operation_completed_count; }
 438   void increment_vm_operation_completed_count()  { _vm_operation_completed_count++; }
 439 
 440   // For tracking the heavyweight monitor the thread is pending on.
 441   ObjectMonitor* current_pending_monitor() {
 442     return _current_pending_monitor;
 443   }
 444   void set_current_pending_monitor(ObjectMonitor* monitor) {
 445     _current_pending_monitor = monitor;
 446   }
 447   void set_current_pending_monitor_is_from_java(bool from_java) {
 448     _current_pending_monitor_is_from_java = from_java;
 449   }
 450   bool current_pending_monitor_is_from_java() {
 451     return _current_pending_monitor_is_from_java;
 452   }
 453 
 454   // For tracking the ObjectMonitor on which this thread called Object.wait()
 455   ObjectMonitor* current_waiting_monitor() {
 456     return _current_waiting_monitor;
 457   }
 458   void set_current_waiting_monitor(ObjectMonitor* monitor) {
 459     _current_waiting_monitor = monitor;
 460   }
 461 
 462   // GC support
 463   // Apply "f->do_oop" to all root oops in "this".
 464   // Apply "cld_f->do_cld" to CLDs that are otherwise not kept alive.
 465   //   Used by JavaThread::oops_do.
 466   // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames
 467   virtual void oops_do(OopClosure* f, CLDClosure* cld_f, CodeBlobClosure* cf);
 468 
 469   // Handles the parallel case for the method below.
 470  private:
 471   bool claim_oops_do_par_case(int collection_parity);
 472  public:
 473   // Requires that "collection_parity" is that of the current roots
 474   // iteration.  If "is_par" is false, sets the parity of "this" to
 475   // "collection_parity", and returns "true".  If "is_par" is true,
 476   // uses an atomic instruction to set the current threads parity to
 477   // "collection_parity", if it is not already.  Returns "true" iff the
 478   // calling thread does the update, this indicates that the calling thread
 479   // has claimed the thread's stack as a root groop in the current
 480   // collection.
 481   bool claim_oops_do(bool is_par, int collection_parity) {
 482     if (!is_par) {
 483       _oops_do_parity = collection_parity;
 484       return true;
 485     } else {
 486       return claim_oops_do_par_case(collection_parity);
 487     }
 488   }
 489 
 490   // Sweeper support
 491   void nmethods_do(CodeBlobClosure* cf);
 492 
 493   // jvmtiRedefineClasses support
 494   void metadata_handles_do(void f(Metadata*));
 495 
 496   // Used by fast lock support
 497   virtual bool is_lock_owned(address adr) const;
 498 
 499   // Check if address is in the stack of the thread (not just for locks).
 500   // Warning: the method can only be used on the running thread
 501   bool is_in_stack(address adr) const;
 502   // Check if address is in the usable part of the stack (excludes protected
 503   // guard pages)
 504   bool is_in_usable_stack(address adr) const;
 505 
 506   // Sets this thread as starting thread. Returns failure if thread
 507   // creation fails due to lack of memory, too many threads etc.
 508   bool set_as_starting_thread();
 509 
 510 protected:
 511   // OS data associated with the thread
 512   OSThread* _osthread;  // Platform-specific thread information
 513 
 514   // Thread local resource area for temporary allocation within the VM
 515   ResourceArea* _resource_area;
 516 
 517   DEBUG_ONLY(ResourceMark* _current_resource_mark;)
 518 
 519   // Thread local handle area for allocation of handles within the VM
 520   HandleArea* _handle_area;
 521   GrowableArray<Metadata*>* _metadata_handles;
 522 
 523   // Support for stack overflow handling, get_thread, etc.
 524   address          _stack_base;
 525   size_t           _stack_size;
 526   uintptr_t        _self_raw_id;      // used by get_thread (mutable)
 527   int              _lgrp_id;
 528 
 529  public:
 530   // Stack overflow support
 531   address stack_base() const           { assert(_stack_base != NULL,"Sanity check"); return _stack_base; }
 532 
 533   void    set_stack_base(address base) { _stack_base = base; }
 534   size_t  stack_size() const           { return _stack_size; }
 535   void    set_stack_size(size_t size)  { _stack_size = size; }
 536   void    record_stack_base_and_size();
 537 
 538   bool    on_local_stack(address adr) const {
 539     // QQQ this has knowledge of direction, ought to be a stack method
 540     return (_stack_base >= adr && adr >= (_stack_base - _stack_size));
 541   }
 542 
 543   uintptr_t self_raw_id()                    { return _self_raw_id; }
 544   void      set_self_raw_id(uintptr_t value) { _self_raw_id = value; }
 545 
 546   int     lgrp_id() const        { return _lgrp_id; }
 547   void    set_lgrp_id(int value) { _lgrp_id = value; }
 548 
 549   // Printing
 550   virtual void print_on(outputStream* st) const;
 551   void print() const { print_on(tty); }
 552   virtual void print_on_error(outputStream* st, char* buf, int buflen) const;
 553 
 554   // Debug-only code
 555 #ifdef ASSERT
 556  private:
 557   // Deadlock detection support for Mutex locks. List of locks own by thread.
 558   Monitor* _owned_locks;
 559   // Mutex::set_owner_implementation is the only place where _owned_locks is modified,
 560   // thus the friendship
 561   friend class Mutex;
 562   friend class Monitor;
 563 
 564  public:
 565   void print_owned_locks_on(outputStream* st) const;
 566   void print_owned_locks() const                 { print_owned_locks_on(tty);    }
 567   Monitor* owned_locks() const                   { return _owned_locks;          }
 568   bool owns_locks() const                        { return owned_locks() != NULL; }
 569   bool owns_locks_but_compiled_lock() const;
 570   int oops_do_parity() const                     { return _oops_do_parity; }
 571 
 572   // Deadlock detection
 573   bool allow_allocation()                        { return _allow_allocation_count == 0; }
 574   ResourceMark* current_resource_mark()          { return _current_resource_mark; }
 575   void set_current_resource_mark(ResourceMark* rm) { _current_resource_mark = rm; }
 576 #endif
 577 
 578   void check_for_valid_safepoint_state(bool potential_vm_operation) PRODUCT_RETURN;
 579 
 580  private:
 581   volatile int _jvmti_env_iteration_count;
 582 
 583  public:
 584   void entering_jvmti_env_iteration()            { ++_jvmti_env_iteration_count; }
 585   void leaving_jvmti_env_iteration()             { --_jvmti_env_iteration_count; }
 586   bool is_inside_jvmti_env_iteration()           { return _jvmti_env_iteration_count > 0; }
 587 
 588   // Code generation
 589   static ByteSize exception_file_offset()        { return byte_offset_of(Thread, _exception_file); }
 590   static ByteSize exception_line_offset()        { return byte_offset_of(Thread, _exception_line); }
 591   static ByteSize active_handles_offset()        { return byte_offset_of(Thread, _active_handles); }
 592 
 593   static ByteSize stack_base_offset()            { return byte_offset_of(Thread, _stack_base); }
 594   static ByteSize stack_size_offset()            { return byte_offset_of(Thread, _stack_size); }
 595 
 596 #define TLAB_FIELD_OFFSET(name) \
 597   static ByteSize tlab_##name##_offset()         { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::name##_offset(); }
 598 
 599   TLAB_FIELD_OFFSET(start)
 600   TLAB_FIELD_OFFSET(end)
 601   TLAB_FIELD_OFFSET(top)
 602   TLAB_FIELD_OFFSET(pf_top)
 603   TLAB_FIELD_OFFSET(size)                   // desired_size
 604   TLAB_FIELD_OFFSET(refill_waste_limit)
 605   TLAB_FIELD_OFFSET(number_of_refills)
 606   TLAB_FIELD_OFFSET(fast_refill_waste)
 607   TLAB_FIELD_OFFSET(slow_allocations)
 608 
 609 #undef TLAB_FIELD_OFFSET
 610 
 611   static ByteSize allocated_bytes_offset()       { return byte_offset_of(Thread, _allocated_bytes); }
 612 
 613  public:
 614   volatile intptr_t _Stalled;
 615   volatile int _TypeTag;
 616   ParkEvent * _ParkEvent;                     // for synchronized()
 617   ParkEvent * _SleepEvent;                    // for Thread.sleep
 618   ParkEvent * _MutexEvent;                    // for native internal Mutex/Monitor
 619   ParkEvent * _MuxEvent;                      // for low-level muxAcquire-muxRelease
 620   int NativeSyncRecursion;                    // diagnostic
 621 
 622   volatile int _OnTrap;                       // Resume-at IP delta
 623   jint _hashStateW;                           // Marsaglia Shift-XOR thread-local RNG
 624   jint _hashStateX;                           // thread-specific hashCode generator state
 625   jint _hashStateY;
 626   jint _hashStateZ;
 627   void * _schedctl;
 628 
 629 
 630   volatile jint rng[4];                      // RNG for spin loop
 631 
 632   // Low-level leaf-lock primitives used to implement synchronization
 633   // and native monitor-mutex infrastructure.
 634   // Not for general synchronization use.
 635   static void SpinAcquire(volatile int * Lock, const char * Name);
 636   static void SpinRelease(volatile int * Lock);
 637   static void muxAcquire(volatile intptr_t * Lock, const char * Name);
 638   static void muxAcquireW(volatile intptr_t * Lock, ParkEvent * ev);
 639   static void muxRelease(volatile intptr_t * Lock);
 640 };
 641 
 642 // Inline implementation of Thread::current()
 643 // Thread::current is "hot" it's called > 128K times in the 1st 500 msecs of
 644 // startup.
 645 // ThreadLocalStorage::thread is warm -- it's called > 16K times in the same
 646 // period.   This is inlined in thread_<os_family>.inline.hpp.
 647 
 648 inline Thread* Thread::current() {
 649 #ifdef ASSERT
 650   // This function is very high traffic. Define PARANOID to enable expensive
 651   // asserts.
 652 #ifdef PARANOID
 653   // Signal handler should call ThreadLocalStorage::get_thread_slow()
 654   Thread* t = ThreadLocalStorage::get_thread_slow();
 655   assert(t != NULL && !t->is_inside_signal_handler(),
 656          "Don't use Thread::current() inside signal handler");
 657 #endif
 658 #endif
 659   Thread* thread = ThreadLocalStorage::thread();
 660   assert(thread != NULL, "just checking");
 661   return thread;
 662 }
 663 
 664 // Name support for threads.  non-JavaThread subclasses with multiple
 665 // uniquely named instances should derive from this.
 666 class NamedThread: public Thread {
 667   friend class VMStructs;
 668   enum {
 669     max_name_len = 64
 670   };
 671  private:
 672   char* _name;
 673   // log JavaThread being processed by oops_do
 674   JavaThread* _processed_thread;
 675 
 676  public:
 677   NamedThread();
 678   ~NamedThread();
 679   // May only be called once per thread.
 680   void set_name(const char* format, ...)  ATTRIBUTE_PRINTF(2, 3);
 681   void initialize_named_thread();
 682   virtual bool is_Named_thread() const { return true; }
 683   virtual char* name() const { return _name == NULL ? (char*)"Unknown Thread" : _name; }
 684   JavaThread *processed_thread() { return _processed_thread; }
 685   void set_processed_thread(JavaThread *thread) { _processed_thread = thread; }
 686   virtual void print_on(outputStream* st) const;
 687 };
 688 
 689 // Worker threads are named and have an id of an assigned work.
 690 class WorkerThread: public NamedThread {
 691  private:
 692   uint _id;
 693  public:
 694   WorkerThread() : _id(0)               { }
 695   virtual bool is_Worker_thread() const { return true; }
 696 
 697   virtual WorkerThread* as_Worker_thread() const {
 698     assert(is_Worker_thread(), "Dubious cast to WorkerThread*?");
 699     return (WorkerThread*) this;
 700   }
 701 
 702   void set_id(uint work_id)             { _id = work_id; }
 703   uint id() const                       { return _id; }
 704 };
 705 
 706 // A single WatcherThread is used for simulating timer interrupts.
 707 class WatcherThread: public Thread {
 708   friend class VMStructs;
 709  public:
 710   virtual void run();
 711 
 712  private:
 713   static WatcherThread* _watcher_thread;
 714 
 715   static bool _startable;
 716   // volatile due to at least one lock-free read
 717   volatile static bool _should_terminate;
 718 
 719   os::WatcherThreadCrashProtection* _crash_protection;
 720  public:
 721   enum SomeConstants {
 722     delay_interval = 10                          // interrupt delay in milliseconds
 723   };
 724 
 725   // Constructor
 726   WatcherThread();
 727 
 728   // Tester
 729   bool is_Watcher_thread() const                 { return true; }
 730 
 731   // Printing
 732   char* name() const { return (char*)"VM Periodic Task Thread"; }
 733   void print_on(outputStream* st) const;
 734   void unpark();
 735 
 736   // Returns the single instance of WatcherThread
 737   static WatcherThread* watcher_thread()         { return _watcher_thread; }
 738 
 739   // Create and start the single instance of WatcherThread, or stop it on shutdown
 740   static void start();
 741   static void stop();
 742   // Only allow start once the VM is sufficiently initialized
 743   // Otherwise the first task to enroll will trigger the start
 744   static void make_startable();
 745 
 746   void set_crash_protection(os::WatcherThreadCrashProtection* crash_protection) {
 747     assert(Thread::current()->is_Watcher_thread(), "Can only be set by WatcherThread");
 748     _crash_protection = crash_protection;
 749   }
 750 
 751   bool has_crash_protection() const { return _crash_protection != NULL; }
 752   os::WatcherThreadCrashProtection* crash_protection() const { return _crash_protection; }
 753 
 754  private:
 755   int sleep() const;
 756 };
 757 
 758 
 759 class CompilerThread;
 760 
 761 typedef void (*ThreadFunction)(JavaThread*, TRAPS);
 762 
 763 class JavaThread: public Thread {
 764   friend class VMStructs;
 765   friend class WhiteBox;
 766  private:
 767   JavaThread*    _next;                          // The next thread in the Threads list
 768   oop            _threadObj;                     // The Java level thread object
 769 
 770 #ifdef ASSERT
 771  private:
 772   int _java_call_counter;
 773 
 774  public:
 775   int  java_call_counter()                       { return _java_call_counter; }
 776   void inc_java_call_counter()                   { _java_call_counter++; }
 777   void dec_java_call_counter() {
 778     assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
 779     _java_call_counter--;
 780   }
 781  private:  // restore original namespace restriction
 782 #endif  // ifdef ASSERT
 783 
 784 #ifndef PRODUCT
 785  public:
 786   enum {
 787     jump_ring_buffer_size = 16
 788   };
 789  private:  // restore original namespace restriction
 790 #endif
 791 
 792   JavaFrameAnchor _anchor;                       // Encapsulation of current java frame and it state
 793 
 794   ThreadFunction _entry_point;
 795 
 796   JNIEnv        _jni_environment;
 797 
 798   // Deopt support
 799   DeoptResourceMark*  _deopt_mark;               // Holds special ResourceMark for deoptimization
 800 
 801   intptr_t*      _must_deopt_id;                 // id of frame that needs to be deopted once we
 802                                                  // transition out of native
 803   nmethod*       _deopt_nmethod;                 // nmethod that is currently being deoptimized
 804   vframeArray*  _vframe_array_head;              // Holds the heap of the active vframeArrays
 805   vframeArray*  _vframe_array_last;              // Holds last vFrameArray we popped
 806   // Because deoptimization is lazy we must save jvmti requests to set locals
 807   // in compiled frames until we deoptimize and we have an interpreter frame.
 808   // This holds the pointer to array (yeah like there might be more than one) of
 809   // description of compiled vframes that have locals that need to be updated.
 810   GrowableArray<jvmtiDeferredLocalVariableSet*>* _deferred_locals_updates;
 811 
 812   // Handshake value for fixing 6243940. We need a place for the i2c
 813   // adapter to store the callee Method*. This value is NEVER live
 814   // across a gc point so it does NOT have to be gc'd
 815   // The handshake is open ended since we can't be certain that it will
 816   // be NULLed. This is because we rarely ever see the race and end up
 817   // in handle_wrong_method which is the backend of the handshake. See
 818   // code in i2c adapters and handle_wrong_method.
 819 
 820   Method*       _callee_target;
 821 
 822   // Used to pass back results to the interpreter or generated code running Java code.
 823   oop           _vm_result;    // oop result is GC-preserved
 824   Metadata*     _vm_result_2;  // non-oop result
 825 
 826   // See ReduceInitialCardMarks: this holds the precise space interval of
 827   // the most recent slow path allocation for which compiled code has
 828   // elided card-marks for performance along the fast-path.
 829   MemRegion     _deferred_card_mark;
 830 
 831   MonitorChunk* _monitor_chunks;                 // Contains the off stack monitors
 832                                                  // allocated during deoptimization
 833                                                  // and by JNI_MonitorEnter/Exit
 834 
 835   // Async. requests support
 836   enum AsyncRequests {
 837     _no_async_condition = 0,
 838     _async_exception,
 839     _async_unsafe_access_error
 840   };
 841   AsyncRequests _special_runtime_exit_condition; // Enum indicating pending async. request
 842   oop           _pending_async_exception;
 843 
 844   // Safepoint support
 845  public:                                         // Expose _thread_state for SafeFetchInt()
 846   volatile JavaThreadState _thread_state;
 847  private:
 848   ThreadSafepointState *_safepoint_state;        // Holds information about a thread during a safepoint
 849   address               _saved_exception_pc;     // Saved pc of instruction where last implicit exception happened
 850 
 851   // JavaThread termination support
 852   enum TerminatedTypes {
 853     _not_terminated = 0xDEAD - 2,
 854     _thread_exiting,                             // JavaThread::exit() has been called for this thread
 855     _thread_terminated,                          // JavaThread is removed from thread list
 856     _vm_exited                                   // JavaThread is still executing native code, but VM is terminated
 857                                                  // only VM_Exit can set _vm_exited
 858   };
 859 
 860   // In general a JavaThread's _terminated field transitions as follows:
 861   //
 862   //   _not_terminated => _thread_exiting => _thread_terminated
 863   //
 864   // _vm_exited is a special value to cover the case of a JavaThread
 865   // executing native code after the VM itself is terminated.
 866   volatile TerminatedTypes _terminated;
 867   // suspend/resume support
 868   volatile bool         _suspend_equivalent;     // Suspend equivalent condition
 869   jint                  _in_deopt_handler;       // count of deoptimization
 870                                                  // handlers thread is in
 871   volatile bool         _doing_unsafe_access;    // Thread may fault due to unsafe access
 872   bool                  _do_not_unlock_if_synchronized;  // Do not unlock the receiver of a synchronized method (since it was
 873                                                          // never locked) when throwing an exception. Used by interpreter only.
 874 
 875   // JNI attach states:
 876   enum JNIAttachStates {
 877     _not_attaching_via_jni = 1,  // thread is not attaching via JNI
 878     _attaching_via_jni,          // thread is attaching via JNI
 879     _attached_via_jni            // thread has attached via JNI
 880   };
 881 
 882   // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
 883   // A native thread that is attaching via JNI starts with a value
 884   // of _attaching_via_jni and transitions to _attached_via_jni.
 885   volatile JNIAttachStates _jni_attach_state;
 886 
 887  public:
 888   // State of the stack guard pages for this thread.
 889   enum StackGuardState {
 890     stack_guard_unused,         // not needed
 891     stack_guard_yellow_disabled,// disabled (temporarily) after stack overflow
 892     stack_guard_enabled         // enabled
 893   };
 894 
 895  private:
 896 
 897   StackGuardState  _stack_guard_state;
 898 
 899   // Precompute the limit of the stack as used in stack overflow checks.
 900   // We load it from here to simplify the stack overflow check in assembly.
 901   address          _stack_overflow_limit;
 902 
 903   // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
 904   // used to temp. parsing values into and out of the runtime system during exception handling for compiled
 905   // code)
 906   volatile oop     _exception_oop;               // Exception thrown in compiled code
 907   volatile address _exception_pc;                // PC where exception happened
 908   volatile address _exception_handler_pc;        // PC for handler of exception
 909   volatile int     _is_method_handle_return;     // true (== 1) if the current exception PC is a MethodHandle call site.
 910 
 911   // support for JNI critical regions
 912   jint    _jni_active_critical;                  // count of entries into JNI critical region
 913 
 914   // Checked JNI: function name requires exception check
 915   char* _pending_jni_exception_check_fn;
 916 
 917   // For deadlock detection.
 918   int _depth_first_number;
 919 
 920   // JVMTI PopFrame support
 921   // This is set to popframe_pending to signal that top Java frame should be popped immediately
 922   int _popframe_condition;
 923 
 924   // If reallocation of scalar replaced objects fails, we throw OOM
 925   // and during exception propagation, pop the top
 926   // _frames_to_pop_failed_realloc frames, the ones that reference
 927   // failed reallocations.
 928   int _frames_to_pop_failed_realloc;
 929 
 930 #ifndef PRODUCT
 931   int _jmp_ring_index;
 932   struct {
 933     // We use intptr_t instead of address so debugger doesn't try and display strings
 934     intptr_t _target;
 935     intptr_t _instruction;
 936     const char*  _file;
 937     int _line;
 938   }   _jmp_ring[jump_ring_buffer_size];
 939 #endif // PRODUCT
 940 
 941 #if INCLUDE_ALL_GCS
 942   // Support for G1 barriers
 943 
 944   ObjPtrQueue _satb_mark_queue;          // Thread-local log for SATB barrier.
 945   // Set of all such queues.
 946   static SATBMarkQueueSet _satb_mark_queue_set;
 947 
 948   DirtyCardQueue _dirty_card_queue;      // Thread-local log for dirty cards.
 949   // Set of all such queues.
 950   static DirtyCardQueueSet _dirty_card_queue_set;
 951 
 952   void flush_barrier_queues();
 953 #endif // INCLUDE_ALL_GCS
 954 
 955   friend class VMThread;
 956   friend class ThreadWaitTransition;
 957   friend class VM_Exit;
 958 
 959   void initialize();                             // Initialized the instance variables
 960 
 961  public:
 962   // Constructor
 963   JavaThread(bool is_attaching_via_jni = false); // for main thread and JNI attached threads
 964   JavaThread(ThreadFunction entry_point, size_t stack_size = 0);
 965   ~JavaThread();
 966 
 967 #ifdef ASSERT
 968   // verify this JavaThread hasn't be published in the Threads::list yet
 969   void verify_not_published();
 970 #endif
 971 
 972   //JNI functiontable getter/setter for JVMTI jni function table interception API.
 973   void set_jni_functions(struct JNINativeInterface_* functionTable) {
 974     _jni_environment.functions = functionTable;
 975   }
 976   struct JNINativeInterface_* get_jni_functions() {
 977     return (struct JNINativeInterface_ *)_jni_environment.functions;
 978   }
 979 
 980   // This function is called at thread creation to allow
 981   // platform specific thread variables to be initialized.
 982   void cache_global_variables();
 983 
 984   // Executes Shutdown.shutdown()
 985   void invoke_shutdown_hooks();
 986 
 987   // Cleanup on thread exit
 988   enum ExitType {
 989     normal_exit,
 990     jni_detach
 991   };
 992   void exit(bool destroy_vm, ExitType exit_type = normal_exit);
 993 
 994   void cleanup_failed_attach_current_thread();
 995 
 996   // Testers
 997   virtual bool is_Java_thread() const            { return true;  }
 998 
 999   // Thread chain operations
1000   JavaThread* next() const                       { return _next; }
1001   void set_next(JavaThread* p)                   { _next = p; }
1002 
1003   // Thread oop. threadObj() can be NULL for initial JavaThread
1004   // (or for threads attached via JNI)
1005   oop threadObj() const                          { return _threadObj; }
1006   void set_threadObj(oop p)                      { _threadObj = p; }
1007 
1008   ThreadPriority java_priority() const;          // Read from threadObj()
1009 
1010   // Prepare thread and add to priority queue.  If a priority is
1011   // not specified, use the priority of the thread object. Threads_lock
1012   // must be held while this function is called.
1013   void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
1014   void prepare_ext();
1015 
1016   void set_saved_exception_pc(address pc)        { _saved_exception_pc = pc; }
1017   address saved_exception_pc()                   { return _saved_exception_pc; }
1018 
1019 
1020   ThreadFunction entry_point() const             { return _entry_point; }
1021 
1022   // Allocates a new Java level thread object for this thread. thread_name may be NULL.
1023   void allocate_threadObj(Handle thread_group, const char* thread_name, bool daemon, TRAPS);
1024 
1025   // Last frame anchor routines
1026 
1027   JavaFrameAnchor* frame_anchor(void)            { return &_anchor; }
1028 
1029   // last_Java_sp
1030   bool has_last_Java_frame() const               { return _anchor.has_last_Java_frame(); }
1031   intptr_t* last_Java_sp() const                 { return _anchor.last_Java_sp(); }
1032 
1033   // last_Java_pc
1034 
1035   address last_Java_pc(void)                     { return _anchor.last_Java_pc(); }
1036 
1037   // Safepoint support
1038 #if !(defined(PPC64) || defined(AARCH64))
1039   JavaThreadState thread_state() const           { return _thread_state; }
1040   void set_thread_state(JavaThreadState s)       { _thread_state = s;    }
1041 #else
1042   // Use membars when accessing volatile _thread_state. See
1043   // Threads::create_vm() for size checks.
1044   inline JavaThreadState thread_state() const;
1045   inline void set_thread_state(JavaThreadState s);
1046 #endif
1047   ThreadSafepointState *safepoint_state() const  { return _safepoint_state; }
1048   void set_safepoint_state(ThreadSafepointState *state) { _safepoint_state = state; }
1049   bool is_at_poll_safepoint()                    { return _safepoint_state->is_at_poll_safepoint(); }
1050 
1051   // thread has called JavaThread::exit() or is terminated
1052   bool is_exiting()                              { return _terminated == _thread_exiting || is_terminated(); }
1053   // thread is terminated (no longer on the threads list); we compare
1054   // against the two non-terminated values so that a freed JavaThread
1055   // will also be considered terminated.
1056   bool is_terminated()                           { return _terminated != _not_terminated && _terminated != _thread_exiting; }
1057   void set_terminated(TerminatedTypes t)         { _terminated = t; }
1058   // special for Threads::remove() which is static:
1059   void set_terminated_value()                    { _terminated = _thread_terminated; }
1060   void block_if_vm_exited();
1061 
1062   bool doing_unsafe_access()                     { return _doing_unsafe_access; }
1063   void set_doing_unsafe_access(bool val)         { _doing_unsafe_access = val; }
1064 
1065   bool do_not_unlock_if_synchronized()             { return _do_not_unlock_if_synchronized; }
1066   void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
1067 
1068   // Suspend/resume support for JavaThread
1069  private:
1070   inline void set_ext_suspended();
1071   inline void clear_ext_suspended();
1072 
1073  public:
1074   void java_suspend();
1075   void java_resume();
1076   int  java_suspend_self();
1077 
1078   void check_and_wait_while_suspended() {
1079     assert(JavaThread::current() == this, "sanity check");
1080 
1081     bool do_self_suspend;
1082     do {
1083       // were we externally suspended while we were waiting?
1084       do_self_suspend = handle_special_suspend_equivalent_condition();
1085       if (do_self_suspend) {
1086         // don't surprise the thread that suspended us by returning
1087         java_suspend_self();
1088         set_suspend_equivalent();
1089       }
1090     } while (do_self_suspend);
1091   }
1092   static void check_safepoint_and_suspend_for_native_trans(JavaThread *thread);
1093   // Check for async exception in addition to safepoint and suspend request.
1094   static void check_special_condition_for_native_trans(JavaThread *thread);
1095 
1096   // Same as check_special_condition_for_native_trans but finishes the
1097   // transition into thread_in_Java mode so that it can potentially
1098   // block.
1099   static void check_special_condition_for_native_trans_and_transition(JavaThread *thread);
1100 
1101   bool is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits);
1102   bool is_ext_suspend_completed_with_lock(uint32_t *bits) {
1103     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1104     // Warning: is_ext_suspend_completed() may temporarily drop the
1105     // SR_lock to allow the thread to reach a stable thread state if
1106     // it is currently in a transient thread state.
1107     return is_ext_suspend_completed(false /* !called_by_wait */,
1108                                     SuspendRetryDelay, bits);
1109   }
1110 
1111   // We cannot allow wait_for_ext_suspend_completion() to run forever or
1112   // we could hang. SuspendRetryCount and SuspendRetryDelay are normally
1113   // passed as the count and delay parameters. Experiments with specific
1114   // calls to wait_for_ext_suspend_completion() can be done by passing
1115   // other values in the code. Experiments with all calls can be done
1116   // via the appropriate -XX options.
1117   bool wait_for_ext_suspend_completion(int count, int delay, uint32_t *bits);
1118 
1119   inline void set_external_suspend();
1120   inline void clear_external_suspend();
1121 
1122   inline void set_deopt_suspend();
1123   inline void clear_deopt_suspend();
1124   bool is_deopt_suspend()         { return (_suspend_flags & _deopt_suspend) != 0; }
1125 
1126   bool is_external_suspend() const {
1127     return (_suspend_flags & _external_suspend) != 0;
1128   }
1129   // Whenever a thread transitions from native to vm/java it must suspend
1130   // if external|deopt suspend is present.
1131   bool is_suspend_after_native() const {
1132     return (_suspend_flags & (_external_suspend | _deopt_suspend)) != 0;
1133   }
1134 
1135   // external suspend request is completed
1136   bool is_ext_suspended() const {
1137     return (_suspend_flags & _ext_suspended) != 0;
1138   }
1139 
1140   bool is_external_suspend_with_lock() const {
1141     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1142     return is_external_suspend();
1143   }
1144 
1145   // Special method to handle a pending external suspend request
1146   // when a suspend equivalent condition lifts.
1147   bool handle_special_suspend_equivalent_condition() {
1148     assert(is_suspend_equivalent(),
1149            "should only be called in a suspend equivalence condition");
1150     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1151     bool ret = is_external_suspend();
1152     if (!ret) {
1153       // not about to self-suspend so clear suspend equivalence
1154       clear_suspend_equivalent();
1155     }
1156     // implied else:
1157     // We have a pending external suspend request so we leave the
1158     // suspend_equivalent flag set until java_suspend_self() sets
1159     // the ext_suspended flag and clears the suspend_equivalent
1160     // flag. This insures that wait_for_ext_suspend_completion()
1161     // will return consistent values.
1162     return ret;
1163   }
1164 
1165   // utility methods to see if we are doing some kind of suspension
1166   bool is_being_ext_suspended() const            {
1167     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1168     return is_ext_suspended() || is_external_suspend();
1169   }
1170 
1171   bool is_suspend_equivalent() const             { return _suspend_equivalent; }
1172 
1173   void set_suspend_equivalent()                  { _suspend_equivalent = true; }
1174   void clear_suspend_equivalent()                { _suspend_equivalent = false; }
1175 
1176   // Thread.stop support
1177   void send_thread_stop(oop throwable);
1178   AsyncRequests clear_special_runtime_exit_condition() {
1179     AsyncRequests x = _special_runtime_exit_condition;
1180     _special_runtime_exit_condition = _no_async_condition;
1181     return x;
1182   }
1183 
1184   // Are any async conditions present?
1185   bool has_async_condition() { return (_special_runtime_exit_condition != _no_async_condition); }
1186 
1187   void check_and_handle_async_exceptions(bool check_unsafe_error = true);
1188 
1189   // these next two are also used for self-suspension and async exception support
1190   void handle_special_runtime_exit_condition(bool check_asyncs = true);
1191 
1192   // Return true if JavaThread has an asynchronous condition or
1193   // if external suspension is requested.
1194   bool has_special_runtime_exit_condition() {
1195     // We call is_external_suspend() last since external suspend should
1196     // be less common. Because we don't use is_external_suspend_with_lock
1197     // it is possible that we won't see an asynchronous external suspend
1198     // request that has just gotten started, i.e., SR_lock grabbed but
1199     // _external_suspend field change either not made yet or not visible
1200     // yet. However, this is okay because the request is asynchronous and
1201     // we will see the new flag value the next time through. It's also
1202     // possible that the external suspend request is dropped after
1203     // we have checked is_external_suspend(), we will recheck its value
1204     // under SR_lock in java_suspend_self().
1205     return (_special_runtime_exit_condition != _no_async_condition) ||
1206             is_external_suspend() || is_deopt_suspend();
1207   }
1208 
1209   void set_pending_unsafe_access_error()          { _special_runtime_exit_condition = _async_unsafe_access_error; }
1210 
1211   inline void set_pending_async_exception(oop e);
1212 
1213   // Fast-locking support
1214   bool is_lock_owned(address adr) const;
1215 
1216   // Accessors for vframe array top
1217   // The linked list of vframe arrays are sorted on sp. This means when we
1218   // unpack the head must contain the vframe array to unpack.
1219   void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
1220   vframeArray* vframe_array_head() const         { return _vframe_array_head;  }
1221 
1222   // Side structure for deferring update of java frame locals until deopt occurs
1223   GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred_locals() const { return _deferred_locals_updates; }
1224   void set_deferred_locals(GrowableArray<jvmtiDeferredLocalVariableSet *>* vf) { _deferred_locals_updates = vf; }
1225 
1226   // These only really exist to make debugging deopt problems simpler
1227 
1228   void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
1229   vframeArray* vframe_array_last() const         { return _vframe_array_last;  }
1230 
1231   // The special resourceMark used during deoptimization
1232 
1233   void set_deopt_mark(DeoptResourceMark* value)  { _deopt_mark = value; }
1234   DeoptResourceMark* deopt_mark(void)            { return _deopt_mark; }
1235 
1236   intptr_t* must_deopt_id()                      { return _must_deopt_id; }
1237   void     set_must_deopt_id(intptr_t* id)       { _must_deopt_id = id; }
1238   void     clear_must_deopt_id()                 { _must_deopt_id = NULL; }
1239 
1240   void set_deopt_nmethod(nmethod* nm)            { _deopt_nmethod = nm;   }
1241   nmethod* deopt_nmethod()                       { return _deopt_nmethod; }
1242 
1243   Method*    callee_target() const               { return _callee_target; }
1244   void set_callee_target  (Method* x)          { _callee_target   = x; }
1245 
1246   // Oop results of vm runtime calls
1247   oop  vm_result() const                         { return _vm_result; }
1248   void set_vm_result  (oop x)                    { _vm_result   = x; }
1249 
1250   Metadata*    vm_result_2() const               { return _vm_result_2; }
1251   void set_vm_result_2  (Metadata* x)          { _vm_result_2   = x; }
1252 
1253   MemRegion deferred_card_mark() const           { return _deferred_card_mark; }
1254   void set_deferred_card_mark(MemRegion mr)      { _deferred_card_mark = mr;   }
1255 
1256   // Exception handling for compiled methods
1257   oop      exception_oop() const                 { return _exception_oop; }
1258   address  exception_pc() const                  { return _exception_pc; }
1259   address  exception_handler_pc() const          { return _exception_handler_pc; }
1260   bool     is_method_handle_return() const       { return _is_method_handle_return == 1; }
1261 
1262   void set_exception_oop(oop o)                  { (void)const_cast<oop&>(_exception_oop = o); }
1263   void set_exception_pc(address a)               { _exception_pc = a; }
1264   void set_exception_handler_pc(address a)       { _exception_handler_pc = a; }
1265   void set_is_method_handle_return(bool value)   { _is_method_handle_return = value ? 1 : 0; }
1266 
1267   void clear_exception_oop_and_pc() {
1268     set_exception_oop(NULL);
1269     set_exception_pc(NULL);
1270   }
1271 
1272   // Stack overflow support
1273   inline size_t stack_available(address cur_sp);
1274   address stack_yellow_zone_base() {
1275     return (address)(stack_base() -
1276                      (stack_size() -
1277                      (stack_red_zone_size() + stack_yellow_zone_size())));
1278   }
1279   size_t  stack_yellow_zone_size() {
1280     return StackYellowPages * os::vm_page_size();
1281   }
1282   address stack_red_zone_base() {
1283     return (address)(stack_base() - (stack_size() - stack_red_zone_size()));
1284   }
1285   size_t stack_red_zone_size() { return StackRedPages * os::vm_page_size(); }
1286   bool in_stack_yellow_zone(address a) {
1287     return (a <= stack_yellow_zone_base()) && (a >= stack_red_zone_base());
1288   }
1289   bool in_stack_red_zone(address a) {
1290     return (a <= stack_red_zone_base()) &&
1291            (a >= (address)((intptr_t)stack_base() - stack_size()));
1292   }
1293 
1294   void create_stack_guard_pages();
1295   void remove_stack_guard_pages();
1296 
1297   void enable_stack_yellow_zone();
1298   void disable_stack_yellow_zone();
1299   void enable_stack_red_zone();
1300   void disable_stack_red_zone();
1301 
1302   inline bool stack_guard_zone_unused();
1303   inline bool stack_yellow_zone_disabled();
1304   inline bool stack_yellow_zone_enabled();
1305 
1306   // Attempt to reguard the stack after a stack overflow may have occurred.
1307   // Returns true if (a) guard pages are not needed on this thread, (b) the
1308   // pages are already guarded, or (c) the pages were successfully reguarded.
1309   // Returns false if there is not enough stack space to reguard the pages, in
1310   // which case the caller should unwind a frame and try again.  The argument
1311   // should be the caller's (approximate) sp.
1312   bool reguard_stack(address cur_sp);
1313   // Similar to above but see if current stackpoint is out of the guard area
1314   // and reguard if possible.
1315   bool reguard_stack(void);
1316 
1317   address stack_overflow_limit() { return _stack_overflow_limit; }
1318   void set_stack_overflow_limit() {
1319     _stack_overflow_limit = _stack_base - _stack_size +
1320                             ((StackShadowPages +
1321                               StackYellowPages +
1322                               StackRedPages) * os::vm_page_size());
1323   }
1324 
1325   // Misc. accessors/mutators
1326   void set_do_not_unlock(void)                   { _do_not_unlock_if_synchronized = true; }
1327   void clr_do_not_unlock(void)                   { _do_not_unlock_if_synchronized = false; }
1328   bool do_not_unlock(void)                       { return _do_not_unlock_if_synchronized; }
1329 
1330 #ifndef PRODUCT
1331   void record_jump(address target, address instr, const char* file, int line);
1332 #endif // PRODUCT
1333 
1334   // For assembly stub generation
1335   static ByteSize threadObj_offset()             { return byte_offset_of(JavaThread, _threadObj); }
1336 #ifndef PRODUCT
1337   static ByteSize jmp_ring_index_offset()        { return byte_offset_of(JavaThread, _jmp_ring_index); }
1338   static ByteSize jmp_ring_offset()              { return byte_offset_of(JavaThread, _jmp_ring); }
1339 #endif // PRODUCT
1340   static ByteSize jni_environment_offset()       { return byte_offset_of(JavaThread, _jni_environment); }
1341   static ByteSize last_Java_sp_offset() {
1342     return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
1343   }
1344   static ByteSize last_Java_pc_offset() {
1345     return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
1346   }
1347   static ByteSize frame_anchor_offset() {
1348     return byte_offset_of(JavaThread, _anchor);
1349   }
1350   static ByteSize callee_target_offset()         { return byte_offset_of(JavaThread, _callee_target); }
1351   static ByteSize vm_result_offset()             { return byte_offset_of(JavaThread, _vm_result); }
1352   static ByteSize vm_result_2_offset()           { return byte_offset_of(JavaThread, _vm_result_2); }
1353   static ByteSize thread_state_offset()          { return byte_offset_of(JavaThread, _thread_state); }
1354   static ByteSize saved_exception_pc_offset()    { return byte_offset_of(JavaThread, _saved_exception_pc); }
1355   static ByteSize osthread_offset()              { return byte_offset_of(JavaThread, _osthread); }
1356   static ByteSize exception_oop_offset()         { return byte_offset_of(JavaThread, _exception_oop); }
1357   static ByteSize exception_pc_offset()          { return byte_offset_of(JavaThread, _exception_pc); }
1358   static ByteSize exception_handler_pc_offset()  { return byte_offset_of(JavaThread, _exception_handler_pc); }
1359   static ByteSize stack_overflow_limit_offset()  { return byte_offset_of(JavaThread, _stack_overflow_limit); }
1360   static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); }
1361   static ByteSize stack_guard_state_offset()     { return byte_offset_of(JavaThread, _stack_guard_state); }
1362   static ByteSize suspend_flags_offset()         { return byte_offset_of(JavaThread, _suspend_flags); }
1363 
1364   static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
1365   static ByteSize should_post_on_exceptions_flag_offset() {
1366     return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
1367   }
1368 
1369 #if INCLUDE_ALL_GCS
1370   static ByteSize satb_mark_queue_offset()       { return byte_offset_of(JavaThread, _satb_mark_queue); }
1371   static ByteSize dirty_card_queue_offset()      { return byte_offset_of(JavaThread, _dirty_card_queue); }
1372 #endif // INCLUDE_ALL_GCS
1373 
1374   // Returns the jni environment for this thread
1375   JNIEnv* jni_environment()                      { return &_jni_environment; }
1376 
1377   static JavaThread* thread_from_jni_environment(JNIEnv* env) {
1378     JavaThread *thread_from_jni_env = (JavaThread*)((intptr_t)env - in_bytes(jni_environment_offset()));
1379     // Only return NULL if thread is off the thread list; starting to
1380     // exit should not return NULL.
1381     if (thread_from_jni_env->is_terminated()) {
1382       thread_from_jni_env->block_if_vm_exited();
1383       return NULL;
1384     } else {
1385       return thread_from_jni_env;
1386     }
1387   }
1388 
1389   // JNI critical regions. These can nest.
1390   bool in_critical()    { return _jni_active_critical > 0; }
1391   bool in_last_critical()  { return _jni_active_critical == 1; }
1392   void enter_critical() {
1393     assert(Thread::current() == this ||
1394            (Thread::current()->is_VM_thread() &&
1395            SafepointSynchronize::is_synchronizing()),
1396            "this must be current thread or synchronizing");
1397     _jni_active_critical++;
1398   }
1399   void exit_critical() {
1400     assert(Thread::current() == this, "this must be current thread");
1401     _jni_active_critical--;
1402     assert(_jni_active_critical >= 0, "JNI critical nesting problem?");
1403   }
1404 
1405   // Checked JNI, is the programmer required to check for exceptions, specify which function name
1406   bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != NULL; }
1407   void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = NULL; }
1408   const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; }
1409   void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; }
1410 
1411   // For deadlock detection
1412   int depth_first_number() { return _depth_first_number; }
1413   void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
1414 
1415  private:
1416   void set_monitor_chunks(MonitorChunk* monitor_chunks) { _monitor_chunks = monitor_chunks; }
1417 
1418  public:
1419   MonitorChunk* monitor_chunks() const           { return _monitor_chunks; }
1420   void add_monitor_chunk(MonitorChunk* chunk);
1421   void remove_monitor_chunk(MonitorChunk* chunk);
1422   bool in_deopt_handler() const                  { return _in_deopt_handler > 0; }
1423   void inc_in_deopt_handler()                    { _in_deopt_handler++; }
1424   void dec_in_deopt_handler() {
1425     assert(_in_deopt_handler > 0, "mismatched deopt nesting");
1426     if (_in_deopt_handler > 0) { // robustness
1427       _in_deopt_handler--;
1428     }
1429   }
1430 
1431  private:
1432   void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
1433 
1434  public:
1435 
1436   // Frame iteration; calls the function f for all frames on the stack
1437   void frames_do(void f(frame*, const RegisterMap*));
1438 
1439   // Memory operations
1440   void oops_do(OopClosure* f, CLDClosure* cld_f, CodeBlobClosure* cf);
1441 
1442   // Sweeper operations
1443   void nmethods_do(CodeBlobClosure* cf);
1444 
1445   // RedefineClasses Support
1446   void metadata_do(void f(Metadata*));
1447 
1448   // Misc. operations
1449   char* name() const { return (char*)get_thread_name(); }
1450   void print_on(outputStream* st) const;
1451   void print_value();
1452   void print_thread_state_on(outputStream*) const      PRODUCT_RETURN;
1453   void print_thread_state() const                      PRODUCT_RETURN;
1454   void print_on_error(outputStream* st, char* buf, int buflen) const;
1455   void verify();
1456   const char* get_thread_name() const;
1457  private:
1458   // factor out low-level mechanics for use in both normal and error cases
1459   const char* get_thread_name_string(char* buf = NULL, int buflen = 0) const;
1460  public:
1461   const char* get_threadgroup_name() const;
1462   const char* get_parent_name() const;
1463 
1464   // Accessing frames
1465   frame last_frame() {
1466     _anchor.make_walkable(this);
1467     return pd_last_frame();
1468   }
1469   javaVFrame* last_java_vframe(RegisterMap* reg_map);
1470 
1471   // Returns method at 'depth' java or native frames down the stack
1472   // Used for security checks
1473   Klass* security_get_caller_class(int depth);
1474 
1475   // Print stack trace in external format
1476   void print_stack_on(outputStream* st);
1477   void print_stack() { print_stack_on(tty); }
1478 
1479   // Print stack traces in various internal formats
1480   void trace_stack()                             PRODUCT_RETURN;
1481   void trace_stack_from(vframe* start_vf)        PRODUCT_RETURN;
1482   void trace_frames()                            PRODUCT_RETURN;
1483   void trace_oops()                              PRODUCT_RETURN;
1484 
1485   // Print an annotated view of the stack frames
1486   void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN;
1487   void validate_frame_layout() {
1488     print_frame_layout(0, true);
1489   }
1490 
1491   // Returns the number of stack frames on the stack
1492   int depth() const;
1493 
1494   // Function for testing deoptimization
1495   void deoptimize();
1496   void make_zombies();
1497 
1498   void deoptimized_wrt_marked_nmethods();
1499 
1500   // Profiling operation (see fprofile.cpp)
1501  public:
1502   bool profile_last_Java_frame(frame* fr);
1503 
1504  private:
1505   ThreadProfiler* _thread_profiler;
1506  private:
1507   friend class FlatProfiler;                    // uses both [gs]et_thread_profiler.
1508   friend class FlatProfilerTask;                // uses get_thread_profiler.
1509   friend class ThreadProfilerMark;              // uses get_thread_profiler.
1510   ThreadProfiler* get_thread_profiler()         { return _thread_profiler; }
1511   ThreadProfiler* set_thread_profiler(ThreadProfiler* tp) {
1512     ThreadProfiler* result = _thread_profiler;
1513     _thread_profiler = tp;
1514     return result;
1515   }
1516 
1517  public:
1518   // Returns the running thread as a JavaThread
1519   static inline JavaThread* current();
1520 
1521   // Returns the active Java thread.  Do not use this if you know you are calling
1522   // from a JavaThread, as it's slower than JavaThread::current.  If called from
1523   // the VMThread, it also returns the JavaThread that instigated the VMThread's
1524   // operation.  You may not want that either.
1525   static JavaThread* active();
1526 
1527   inline CompilerThread* as_CompilerThread();
1528 
1529  public:
1530   virtual void run();
1531   void thread_main_inner();
1532 
1533  private:
1534   // PRIVILEGED STACK
1535   PrivilegedElement*  _privileged_stack_top;
1536   GrowableArray<oop>* _array_for_gc;
1537  public:
1538 
1539   // Returns the privileged_stack information.
1540   PrivilegedElement* privileged_stack_top() const       { return _privileged_stack_top; }
1541   void set_privileged_stack_top(PrivilegedElement *e)   { _privileged_stack_top = e; }
1542   void register_array_for_gc(GrowableArray<oop>* array) { _array_for_gc = array; }
1543 
1544  public:
1545   // Thread local information maintained by JVMTI.
1546   void set_jvmti_thread_state(JvmtiThreadState *value)                           { _jvmti_thread_state = value; }
1547   // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1548   // getter is used to get this JavaThread's JvmtiThreadState if it has
1549   // one which means NULL can be returned. JvmtiThreadState::state_for()
1550   // is used to get the specified JavaThread's JvmtiThreadState if it has
1551   // one or it allocates a new JvmtiThreadState for the JavaThread and
1552   // returns it. JvmtiThreadState::state_for() will return NULL only if
1553   // the specified JavaThread is exiting.
1554   JvmtiThreadState *jvmti_thread_state() const                                   { return _jvmti_thread_state; }
1555   static ByteSize jvmti_thread_state_offset()                                    { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1556   void set_jvmti_get_loaded_classes_closure(JvmtiGetLoadedClassesClosure* value) { _jvmti_get_loaded_classes_closure = value; }
1557   JvmtiGetLoadedClassesClosure* get_jvmti_get_loaded_classes_closure() const     { return _jvmti_get_loaded_classes_closure; }
1558 
1559   // JVMTI PopFrame support
1560   // Setting and clearing popframe_condition
1561   // All of these enumerated values are bits. popframe_pending
1562   // indicates that a PopFrame() has been requested and not yet been
1563   // completed. popframe_processing indicates that that PopFrame() is in
1564   // the process of being completed. popframe_force_deopt_reexecution_bit
1565   // indicates that special handling is required when returning to a
1566   // deoptimized caller.
1567   enum PopCondition {
1568     popframe_inactive                      = 0x00,
1569     popframe_pending_bit                   = 0x01,
1570     popframe_processing_bit                = 0x02,
1571     popframe_force_deopt_reexecution_bit   = 0x04
1572   };
1573   PopCondition popframe_condition()                   { return (PopCondition) _popframe_condition; }
1574   void set_popframe_condition(PopCondition c)         { _popframe_condition = c; }
1575   void set_popframe_condition_bit(PopCondition c)     { _popframe_condition |= c; }
1576   void clear_popframe_condition()                     { _popframe_condition = popframe_inactive; }
1577   static ByteSize popframe_condition_offset()         { return byte_offset_of(JavaThread, _popframe_condition); }
1578   bool has_pending_popframe()                         { return (popframe_condition() & popframe_pending_bit) != 0; }
1579   bool popframe_forcing_deopt_reexecution()           { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
1580   void clear_popframe_forcing_deopt_reexecution()     { _popframe_condition &= ~popframe_force_deopt_reexecution_bit; }
1581 #ifdef CC_INTERP
1582   bool pop_frame_pending(void)                        { return ((_popframe_condition & popframe_pending_bit) != 0); }
1583   void clr_pop_frame_pending(void)                    { _popframe_condition = popframe_inactive; }
1584   bool pop_frame_in_process(void)                     { return ((_popframe_condition & popframe_processing_bit) != 0); }
1585   void set_pop_frame_in_process(void)                 { _popframe_condition |= popframe_processing_bit; }
1586   void clr_pop_frame_in_process(void)                 { _popframe_condition &= ~popframe_processing_bit; }
1587 #endif
1588 
1589   int frames_to_pop_failed_realloc() const            { return _frames_to_pop_failed_realloc; }
1590   void set_frames_to_pop_failed_realloc(int nb)       { _frames_to_pop_failed_realloc = nb; }
1591   void dec_frames_to_pop_failed_realloc()             { _frames_to_pop_failed_realloc--; }
1592 
1593  private:
1594   // Saved incoming arguments to popped frame.
1595   // Used only when popped interpreted frame returns to deoptimized frame.
1596   void*    _popframe_preserved_args;
1597   int      _popframe_preserved_args_size;
1598 
1599  public:
1600   void  popframe_preserve_args(ByteSize size_in_bytes, void* start);
1601   void* popframe_preserved_args();
1602   ByteSize popframe_preserved_args_size();
1603   WordSize popframe_preserved_args_size_in_words();
1604   void  popframe_free_preserved_args();
1605 
1606 
1607  private:
1608   JvmtiThreadState *_jvmti_thread_state;
1609   JvmtiGetLoadedClassesClosure* _jvmti_get_loaded_classes_closure;
1610 
1611   // Used by the interpreter in fullspeed mode for frame pop, method
1612   // entry, method exit and single stepping support. This field is
1613   // only set to non-zero by the VM_EnterInterpOnlyMode VM operation.
1614   // It can be set to zero asynchronously (i.e., without a VM operation
1615   // or a lock) so we have to be very careful.
1616   int               _interp_only_mode;
1617 
1618  public:
1619   // used by the interpreter for fullspeed debugging support (see above)
1620   static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
1621   bool is_interp_only_mode()                { return (_interp_only_mode != 0); }
1622   int get_interp_only_mode()                { return _interp_only_mode; }
1623   void increment_interp_only_mode()         { ++_interp_only_mode; }
1624   void decrement_interp_only_mode()         { --_interp_only_mode; }
1625 
1626   // support for cached flag that indicates whether exceptions need to be posted for this thread
1627   // if this is false, we can avoid deoptimizing when events are thrown
1628   // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
1629  private:
1630   int    _should_post_on_exceptions_flag;
1631 
1632  public:
1633   int   should_post_on_exceptions_flag()  { return _should_post_on_exceptions_flag; }
1634   void  set_should_post_on_exceptions_flag(int val)  { _should_post_on_exceptions_flag = val; }
1635 
1636  private:
1637   ThreadStatistics *_thread_stat;
1638 
1639  public:
1640   ThreadStatistics* get_thread_stat() const    { return _thread_stat; }
1641 
1642   // Return a blocker object for which this thread is blocked parking.
1643   oop current_park_blocker();
1644 
1645  private:
1646   static size_t _stack_size_at_create;
1647 
1648  public:
1649   static inline size_t stack_size_at_create(void) {
1650     return _stack_size_at_create;
1651   }
1652   static inline void set_stack_size_at_create(size_t value) {
1653     _stack_size_at_create = value;
1654   }
1655 
1656 #if INCLUDE_ALL_GCS
1657   // SATB marking queue support
1658   ObjPtrQueue& satb_mark_queue() { return _satb_mark_queue; }
1659   static SATBMarkQueueSet& satb_mark_queue_set() {
1660     return _satb_mark_queue_set;
1661   }
1662 
1663   // Dirty card queue support
1664   DirtyCardQueue& dirty_card_queue() { return _dirty_card_queue; }
1665   static DirtyCardQueueSet& dirty_card_queue_set() {
1666     return _dirty_card_queue_set;
1667   }
1668 #endif // INCLUDE_ALL_GCS
1669 
1670   // This method initializes the SATB and dirty card queues before a
1671   // JavaThread is added to the Java thread list. Right now, we don't
1672   // have to do anything to the dirty card queue (it should have been
1673   // activated when the thread was created), but we have to activate
1674   // the SATB queue if the thread is created while a marking cycle is
1675   // in progress. The activation / de-activation of the SATB queues at
1676   // the beginning / end of a marking cycle is done during safepoints
1677   // so we have to make sure this method is called outside one to be
1678   // able to safely read the active field of the SATB queue set. Right
1679   // now, it is called just before the thread is added to the Java
1680   // thread list in the Threads::add() method. That method is holding
1681   // the Threads_lock which ensures we are outside a safepoint. We
1682   // cannot do the obvious and set the active field of the SATB queue
1683   // when the thread is created given that, in some cases, safepoints
1684   // might happen between the JavaThread constructor being called and the
1685   // thread being added to the Java thread list (an example of this is
1686   // when the structure for the DestroyJavaVM thread is created).
1687 #if INCLUDE_ALL_GCS
1688   void initialize_queues();
1689 #else  // INCLUDE_ALL_GCS
1690   void initialize_queues() { }
1691 #endif // INCLUDE_ALL_GCS
1692 
1693   // Machine dependent stuff
1694 #ifdef TARGET_OS_ARCH_linux_x86
1695 # include "thread_linux_x86.hpp"
1696 #endif
1697 #ifdef TARGET_OS_ARCH_linux_sparc
1698 # include "thread_linux_sparc.hpp"
1699 #endif
1700 #ifdef TARGET_OS_ARCH_linux_zero
1701 # include "thread_linux_zero.hpp"
1702 #endif
1703 #ifdef TARGET_OS_ARCH_solaris_x86
1704 # include "thread_solaris_x86.hpp"
1705 #endif
1706 #ifdef TARGET_OS_ARCH_solaris_sparc
1707 # include "thread_solaris_sparc.hpp"
1708 #endif
1709 #ifdef TARGET_OS_ARCH_windows_x86
1710 # include "thread_windows_x86.hpp"
1711 #endif
1712 #ifdef TARGET_OS_ARCH_linux_arm
1713 # include "thread_linux_arm.hpp"
1714 #endif
1715 #ifdef TARGET_OS_ARCH_linux_ppc
1716 # include "thread_linux_ppc.hpp"
1717 #endif
1718 #ifdef TARGET_OS_ARCH_linux_aarch64
1719 # include "thread_linux_aarch64.hpp"
1720 #endif
1721 #ifdef TARGET_OS_ARCH_aix_ppc
1722 # include "thread_aix_ppc.hpp"
1723 #endif
1724 #ifdef TARGET_OS_ARCH_bsd_x86
1725 # include "thread_bsd_x86.hpp"
1726 #endif
1727 #ifdef TARGET_OS_ARCH_bsd_zero
1728 # include "thread_bsd_zero.hpp"
1729 #endif
1730 
1731 
1732  public:
1733   void set_blocked_on_compilation(bool value) {
1734     _blocked_on_compilation = value;
1735   }
1736 
1737   bool blocked_on_compilation() {
1738     return _blocked_on_compilation;
1739   }
1740  protected:
1741   bool         _blocked_on_compilation;
1742 
1743 
1744   // JSR166 per-thread parker
1745  private:
1746   Parker*    _parker;
1747  public:
1748   Parker*     parker() { return _parker; }
1749 
1750   // Biased locking support
1751  private:
1752   GrowableArray<MonitorInfo*>* _cached_monitor_info;
1753  public:
1754   GrowableArray<MonitorInfo*>* cached_monitor_info() { return _cached_monitor_info; }
1755   void set_cached_monitor_info(GrowableArray<MonitorInfo*>* info) { _cached_monitor_info = info; }
1756 
1757   // clearing/querying jni attach status
1758   bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; }
1759   bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
1760   inline void set_done_attaching_via_jni();
1761  private:
1762   // This field is used to determine if a thread has claimed
1763   // a par_id: it is UINT_MAX if the thread has not claimed a par_id;
1764   // otherwise its value is the par_id that has been claimed.
1765   uint _claimed_par_id;
1766  public:
1767   uint get_claimed_par_id() { return _claimed_par_id; }
1768   void set_claimed_par_id(uint id) { _claimed_par_id = id; }
1769 };
1770 
1771 // Inline implementation of JavaThread::current
1772 inline JavaThread* JavaThread::current() {
1773   Thread* thread = ThreadLocalStorage::thread();
1774   assert(thread != NULL && thread->is_Java_thread(), "just checking");
1775   return (JavaThread*)thread;
1776 }
1777 
1778 inline CompilerThread* JavaThread::as_CompilerThread() {
1779   assert(is_Compiler_thread(), "just checking");
1780   return (CompilerThread*)this;
1781 }
1782 
1783 // Dedicated thread to sweep the code cache
1784 class CodeCacheSweeperThread : public JavaThread {
1785   nmethod*       _scanned_nmethod; // nmethod being scanned by the sweeper
1786  public:
1787   CodeCacheSweeperThread();
1788   // Track the nmethod currently being scanned by the sweeper
1789   void set_scanned_nmethod(nmethod* nm) {
1790     assert(_scanned_nmethod == NULL || nm == NULL, "should reset to NULL before writing a new value");
1791     _scanned_nmethod = nm;
1792   }
1793 
1794   // Hide sweeper thread from external view.
1795   bool is_hidden_from_external_view() const { return true; }
1796 
1797   bool is_Code_cache_sweeper_thread() const { return true; }
1798   // GC support
1799   // Apply "f->do_oop" to all root oops in "this".
1800   // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames
1801   void oops_do(OopClosure* f, CLDClosure* cld_f, CodeBlobClosure* cf);
1802 };
1803 
1804 // A thread used for Compilation.
1805 class CompilerThread : public JavaThread {
1806   friend class VMStructs;
1807  private:
1808   CompilerCounters* _counters;
1809 
1810   ciEnv*            _env;
1811   CompileLog*       _log;
1812   CompileTask*      _task;
1813   CompileQueue*     _queue;
1814   BufferBlob*       _buffer_blob;
1815 
1816   AbstractCompiler* _compiler;
1817 
1818  public:
1819 
1820   static CompilerThread* current();
1821 
1822   CompilerThread(CompileQueue* queue, CompilerCounters* counters);
1823 
1824   bool is_Compiler_thread() const                { return true; }
1825   // Hide this compiler thread from external view.
1826   bool is_hidden_from_external_view() const      { return true; }
1827 
1828   void set_compiler(AbstractCompiler* c)         { _compiler = c; }
1829   AbstractCompiler* compiler() const             { return _compiler; }
1830 
1831   CompileQueue* queue()        const             { return _queue; }
1832   CompilerCounters* counters() const             { return _counters; }
1833 
1834   // Get/set the thread's compilation environment.
1835   ciEnv*        env()                            { return _env; }
1836   void          set_env(ciEnv* env)              { _env = env; }
1837 
1838   BufferBlob*   get_buffer_blob() const          { return _buffer_blob; }
1839   void          set_buffer_blob(BufferBlob* b)   { _buffer_blob = b; }
1840 
1841   // Get/set the thread's logging information
1842   CompileLog*   log()                            { return _log; }
1843   void          init_log(CompileLog* log) {
1844     // Set once, for good.
1845     assert(_log == NULL, "set only once");
1846     _log = log;
1847   }
1848 
1849 #ifndef PRODUCT
1850  private:
1851   IdealGraphPrinter *_ideal_graph_printer;
1852  public:
1853   IdealGraphPrinter *ideal_graph_printer()           { return _ideal_graph_printer; }
1854   void set_ideal_graph_printer(IdealGraphPrinter *n) { _ideal_graph_printer = n; }
1855 #endif
1856 
1857   // Get/set the thread's current task
1858   CompileTask* task()                      { return _task; }
1859   void         set_task(CompileTask* task) { _task = task; }
1860 };
1861 
1862 inline CompilerThread* CompilerThread::current() {
1863   return JavaThread::current()->as_CompilerThread();
1864 }
1865 
1866 // The active thread queue. It also keeps track of the current used
1867 // thread priorities.
1868 class Threads: AllStatic {
1869   friend class VMStructs;
1870  private:
1871   static JavaThread* _thread_list;
1872   static int         _number_of_threads;
1873   static int         _number_of_non_daemon_threads;
1874   static int         _return_code;
1875   static int         _thread_claim_parity;
1876 #ifdef ASSERT
1877   static bool        _vm_complete;
1878 #endif
1879 
1880   static void initialize_java_lang_classes(JavaThread* main_thread, TRAPS);
1881   static void initialize_jsr292_core_classes(TRAPS);
1882  public:
1883   // Thread management
1884   // force_daemon is a concession to JNI, where we may need to add a
1885   // thread to the thread list before allocating its thread object
1886   static void add(JavaThread* p, bool force_daemon = false);
1887   static void remove(JavaThread* p);
1888   static bool includes(JavaThread* p);
1889   static JavaThread* first()                     { return _thread_list; }
1890   static void threads_do(ThreadClosure* tc);
1891 
1892   // Initializes the vm and creates the vm thread
1893   static jint create_vm(JavaVMInitArgs* args, bool* canTryAgain);
1894   static void convert_vm_init_libraries_to_agents();
1895   static void create_vm_init_libraries();
1896   static void create_vm_init_agents();
1897   static void shutdown_vm_agents();
1898   static bool destroy_vm();
1899   // Supported VM versions via JNI
1900   // Includes JNI_VERSION_1_1
1901   static jboolean is_supported_jni_version_including_1_1(jint version);
1902   // Does not include JNI_VERSION_1_1
1903   static jboolean is_supported_jni_version(jint version);
1904 
1905   // The "thread claim parity" provides a way for threads to be claimed
1906   // by parallel worker tasks.
1907   //
1908   // Each thread contains a a "parity" field. A task will claim the
1909   // thread only if its parity field is the same as the global parity,
1910   // which is updated by calling change_thread_claim_parity().
1911   //
1912   // For this to work change_thread_claim_parity() needs to be called
1913   // exactly once in sequential code before starting parallel tasks
1914   // that should claim threads.
1915   //
1916   // New threads get their parity set to 0 and change_thread_claim_parity()
1917   // never set the global parity to 0.
1918   static int thread_claim_parity() { return _thread_claim_parity; }
1919   static void change_thread_claim_parity();
1920   static void assert_all_threads_claimed() NOT_DEBUG_RETURN;
1921 
1922   // Apply "f->do_oop" to all root oops in all threads.
1923   // This version may only be called by sequential code.
1924   static void oops_do(OopClosure* f, CLDClosure* cld_f, CodeBlobClosure* cf);
1925   // This version may be called by sequential or parallel code.
1926   static void possibly_parallel_oops_do(bool is_par, OopClosure* f, CLDClosure* cld_f, CodeBlobClosure* cf);
1927   // This creates a list of GCTasks, one per thread.
1928   static void create_thread_roots_tasks(GCTaskQueue* q);
1929   // This creates a list of GCTasks, one per thread, for marking objects.
1930   static void create_thread_roots_marking_tasks(GCTaskQueue* q);
1931 
1932   // Apply "f->do_oop" to roots in all threads that
1933   // are part of compiled frames
1934   static void compiled_frame_oops_do(OopClosure* f, CodeBlobClosure* cf);
1935 
1936   static void convert_hcode_pointers();
1937   static void restore_hcode_pointers();
1938 
1939   // Sweeper
1940   static void nmethods_do(CodeBlobClosure* cf);
1941 
1942   // RedefineClasses support
1943   static void metadata_do(void f(Metadata*));
1944   static void metadata_handles_do(void f(Metadata*));
1945 
1946 #ifdef ASSERT
1947   static bool is_vm_complete() { return _vm_complete; }
1948 #endif
1949 
1950   // Verification
1951   static void verify();
1952   static void print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks);
1953   static void print(bool print_stacks, bool internal_format) {
1954     // this function is only used by debug.cpp
1955     print_on(tty, print_stacks, internal_format, false /* no concurrent lock printed */);
1956   }
1957   static void print_on_error(outputStream* st, Thread* current, char* buf, int buflen);
1958 
1959   // Get Java threads that are waiting to enter a monitor. If doLock
1960   // is true, then Threads_lock is grabbed as needed. Otherwise, the
1961   // VM needs to be at a safepoint.
1962   static GrowableArray<JavaThread*>* get_pending_threads(int count,
1963                                                          address monitor, bool doLock);
1964 
1965   // Get owning Java thread from the monitor's owner field. If doLock
1966   // is true, then Threads_lock is grabbed as needed. Otherwise, the
1967   // VM needs to be at a safepoint.
1968   static JavaThread *owning_thread_from_monitor_owner(address owner,
1969                                                       bool doLock);
1970 
1971   // Number of threads on the active threads list
1972   static int number_of_threads()                 { return _number_of_threads; }
1973   // Number of non-daemon threads on the active threads list
1974   static int number_of_non_daemon_threads()      { return _number_of_non_daemon_threads; }
1975 
1976   // Deoptimizes all frames tied to marked nmethods
1977   static void deoptimized_wrt_marked_nmethods();
1978 
1979   static JavaThread* find_java_thread_from_java_tid(jlong java_tid);
1980 
1981 };
1982 
1983 
1984 // Thread iterator
1985 class ThreadClosure: public StackObj {
1986  public:
1987   virtual void do_thread(Thread* thread) = 0;
1988 };
1989 
1990 class SignalHandlerMark: public StackObj {
1991  private:
1992   Thread* _thread;
1993  public:
1994   SignalHandlerMark(Thread* t) {
1995     _thread = t;
1996     if (_thread) _thread->enter_signal_handler();
1997   }
1998   ~SignalHandlerMark() {
1999     if (_thread) _thread->leave_signal_handler();
2000     _thread = NULL;
2001   }
2002 };
2003 
2004 
2005 #endif // SHARE_VM_RUNTIME_THREAD_HPP