1 /*
   2  * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_RUNTIME_THREAD_HPP
  26 #define SHARE_VM_RUNTIME_THREAD_HPP
  27 
  28 #include "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 "utilities/exceptions.hpp"
  46 #include "utilities/macros.hpp"
  47 #include "utilities/top.hpp"
  48 #if INCLUDE_ALL_GCS
  49 #include "gc_implementation/g1/dirtyCardQueue.hpp"
  50 #include "gc_implementation/g1/satbQueue.hpp"
  51 #endif // INCLUDE_ALL_GCS
  52 #ifdef TARGET_ARCH_zero
  53 # include "stack_zero.hpp"
  54 #endif
  55 #if INCLUDE_JFR
  56 #include "jfr/support/jfrThreadExtension.hpp"
  57 #endif
  58 
  59 class ThreadSafepointState;
  60 class ThreadProfiler;
  61 
  62 class JvmtiThreadState;
  63 class JvmtiGetLoadedClassesClosure;
  64 class ThreadStatistics;
  65 class ConcurrentLocksDump;
  66 class ParkEvent;
  67 class Parker;
  68 
  69 class ciEnv;
  70 class CompileThread;
  71 class CompileLog;
  72 class CompileTask;
  73 class CompileQueue;
  74 class CompilerCounters;
  75 class vframeArray;
  76 
  77 class DeoptResourceMark;
  78 class jvmtiDeferredLocalVariableSet;
  79 
  80 class GCTaskQueue;
  81 class ThreadClosure;
  82 class IdealGraphPrinter;
  83 
  84 class Metadata;
  85 template <class T, MEMFLAGS F> class ChunkedList;
  86 typedef ChunkedList<Metadata*, mtInternal> MetadataOnStackBuffer;
  87 
  88 DEBUG_ONLY(class ResourceMark;)
  89 
  90 class WorkerThread;
  91 
  92 // Class hierarchy
  93 // - Thread
  94 //   - NamedThread
  95 //     - VMThread
  96 //     - ConcurrentGCThread
  97 //     - WorkerThread
  98 //       - GangWorker
  99 //       - GCTaskThread
 100 //   - JavaThread
 101 //   - WatcherThread
 102 
 103 class Thread: public ThreadShadow {
 104   friend class VMStructs;
 105  private:
 106   // Exception handling
 107   // (Note: _pending_exception and friends are in ThreadShadow)
 108   //oop       _pending_exception;                // pending exception for current thread
 109   // const char* _exception_file;                   // file information for exception (debugging only)
 110   // int         _exception_line;                   // line information for exception (debugging only)
 111  protected:
 112   // Support for forcing alignment of thread objects for biased locking
 113   void*       _real_malloc_address;
 114  public:
 115   void* operator new(size_t size) throw() { return allocate(size, true); }
 116   void* operator new(size_t size, const std::nothrow_t& nothrow_constant) throw() {
 117     return allocate(size, false); }
 118   void  operator delete(void* p);
 119 
 120  protected:
 121    static void* allocate(size_t size, bool throw_excpt, MEMFLAGS flags = mtThread);
 122  private:
 123 
 124   // ***************************************************************
 125   // Suspend and resume support
 126   // ***************************************************************
 127   //
 128   // VM suspend/resume no longer exists - it was once used for various
 129   // things including safepoints but was deprecated and finally removed
 130   // in Java 7. Because VM suspension was considered "internal" Java-level
 131   // suspension was considered "external", and this legacy naming scheme
 132   // remains.
 133   //
 134   // External suspend/resume requests come from JVM_SuspendThread,
 135   // JVM_ResumeThread, JVMTI SuspendThread, and finally JVMTI
 136   // ResumeThread. External
 137   // suspend requests cause _external_suspend to be set and external
 138   // resume requests cause _external_suspend to be cleared.
 139   // External suspend requests do not nest on top of other external
 140   // suspend requests. The higher level APIs reject suspend requests
 141   // for already suspended threads.
 142   //
 143   // The external_suspend
 144   // flag is checked by has_special_runtime_exit_condition() and java thread
 145   // will self-suspend when handle_special_runtime_exit_condition() is
 146   // called. Most uses of the _thread_blocked state in JavaThreads are
 147   // considered the same as being externally suspended; if the blocking
 148   // condition lifts, the JavaThread will self-suspend. Other places
 149   // where VM checks for external_suspend include:
 150   //   + mutex granting (do not enter monitors when thread is suspended)
 151   //   + state transitions from _thread_in_native
 152   //
 153   // In general, java_suspend() does not wait for an external suspend
 154   // request to complete. When it returns, the only guarantee is that
 155   // the _external_suspend field is true.
 156   //
 157   // wait_for_ext_suspend_completion() is used to wait for an external
 158   // suspend request to complete. External suspend requests are usually
 159   // followed by some other interface call that requires the thread to
 160   // be quiescent, e.g., GetCallTrace(). By moving the "wait time" into
 161   // the interface that requires quiescence, we give the JavaThread a
 162   // chance to self-suspend before we need it to be quiescent. This
 163   // improves overall suspend/query performance.
 164   //
 165   // _suspend_flags controls the behavior of java_ suspend/resume.
 166   // It must be set under the protection of SR_lock. Read from the flag is
 167   // OK without SR_lock as long as the value is only used as a hint.
 168   // (e.g., check _external_suspend first without lock and then recheck
 169   // inside SR_lock and finish the suspension)
 170   //
 171   // _suspend_flags is also overloaded for other "special conditions" so
 172   // that a single check indicates whether any special action is needed
 173   // eg. for async exceptions.
 174   // -------------------------------------------------------------------
 175   // Notes:
 176   // 1. The suspend/resume logic no longer uses ThreadState in OSThread
 177   // but we still update its value to keep other part of the system (mainly
 178   // JVMTI) happy. ThreadState is legacy code (see notes in
 179   // osThread.hpp).
 180   //
 181   // 2. It would be more natural if set_external_suspend() is private and
 182   // part of java_suspend(), but that probably would affect the suspend/query
 183   // performance. Need more investigation on this.
 184   //
 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     JFR_ONLY(_trace_flag    = 0x00000004U)  // call jfr tracing
 202   };
 203 
 204   // various suspension related flags - atomically updated
 205   // overloaded for async exception checking in check_special_condition_for_native_trans.
 206   volatile uint32_t _suspend_flags;
 207 
 208  private:
 209   int _num_nested_signal;
 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  private:
 217   // Debug tracing
 218   static void trace(const char* msg, const Thread* const thread) PRODUCT_RETURN;
 219 
 220   // Active_handles points to a block of handles
 221   JNIHandleBlock* _active_handles;
 222 
 223   // One-element thread local free list
 224   JNIHandleBlock* _free_handle_block;
 225 
 226   // Point to the last handle mark
 227   HandleMark* _last_handle_mark;
 228 
 229   // The parity of the last strong_roots iteration in which this thread was
 230   // claimed as a task.
 231   jint _oops_do_parity;
 232 
 233   public:
 234    void set_last_handle_mark(HandleMark* mark)   { _last_handle_mark = mark; }
 235    HandleMark* last_handle_mark() const          { return _last_handle_mark; }
 236   private:
 237 
 238   // debug support for checking if code does allow safepoints or not
 239   // GC points in the VM can happen because of allocation, invoking a VM operation, or blocking on
 240   // mutex, or blocking on an object synchronizer (Java locking).
 241   // If !allow_safepoint(), then an assertion failure will happen in any of the above cases
 242   // If !allow_allocation(), then an assertion failure will happen during allocation
 243   // (Hence, !allow_safepoint() => !allow_allocation()).
 244   //
 245   // The two classes No_Safepoint_Verifier and No_Allocation_Verifier are used to set these counters.
 246   //
 247   NOT_PRODUCT(int _allow_safepoint_count;)      // If 0, thread allow a safepoint to happen
 248   debug_only (int _allow_allocation_count;)     // If 0, the thread is allowed to allocate oops.
 249 
 250   // Used by SkipGCALot class.
 251   NOT_PRODUCT(bool _skip_gcalot;)               // Should we elide gc-a-lot?
 252 
 253   friend class No_Alloc_Verifier;
 254   friend class No_Safepoint_Verifier;
 255   friend class Pause_No_Safepoint_Verifier;
 256   friend class ThreadLocalStorage;
 257   friend class GC_locker;
 258 
 259   ThreadLocalAllocBuffer _tlab;                 // Thread-local eden
 260   jlong _allocated_bytes;                       // Cumulative number of bytes allocated on
 261                                                 // the Java heap
 262 
 263   // Thread-local buffer used by MetadataOnStackMark.
 264   MetadataOnStackBuffer* _metadata_on_stack_buffer;
 265 
 266   JFR_ONLY(DEFINE_THREAD_LOCAL_FIELD_JFR;)      // Thread-local data for jfr
 267 
 268   ThreadExt _ext;
 269 
 270   int   _vm_operation_started_count;            // VM_Operation support
 271   int   _vm_operation_completed_count;          // VM_Operation support
 272 
 273   ObjectMonitor* _current_pending_monitor;      // ObjectMonitor this thread
 274                                                 // is waiting to lock
 275   bool _current_pending_monitor_is_from_java;   // locking is from Java code
 276 
 277   // ObjectMonitor on which this thread called Object.wait()
 278   ObjectMonitor* _current_waiting_monitor;
 279 
 280   // Private thread-local objectmonitor list - a simple cache organized as a SLL.
 281  public:
 282   ObjectMonitor* omFreeList;
 283   int omFreeCount;                              // length of omFreeList
 284   int omFreeProvision;                          // reload chunk size
 285   ObjectMonitor* omInUseList;                   // SLL to track monitors in circulation
 286   int omInUseCount;                             // length of omInUseList
 287 
 288 #ifdef ASSERT
 289  private:
 290   bool _visited_for_critical_count;
 291 
 292  public:
 293   void set_visited_for_critical_count(bool z) { _visited_for_critical_count = z; }
 294   bool was_visited_for_critical_count() const   { return _visited_for_critical_count; }
 295 #endif
 296 
 297  public:
 298   enum {
 299     is_definitely_current_thread = true
 300   };
 301 
 302   // Constructor
 303   Thread();
 304   virtual ~Thread();
 305 
 306   // initializtion
 307   void initialize_thread_local_storage();
 308 
 309   // thread entry point
 310   virtual void run();
 311 
 312   // Testers
 313   virtual bool is_VM_thread()       const            { return false; }
 314   virtual bool is_Java_thread()     const            { return false; }
 315   virtual bool is_Compiler_thread() const            { return false; }
 316   virtual bool is_hidden_from_external_view() const  { return false; }
 317   virtual bool is_jvmti_agent_thread() const         { return false; }
 318   // True iff the thread can perform GC operations at a safepoint.
 319   // Generally will be true only of VM thread and parallel GC WorkGang
 320   // threads.
 321   virtual bool is_GC_task_thread() const             { return false; }
 322   virtual bool is_Watcher_thread() const             { return false; }
 323   virtual bool is_ConcurrentGC_thread() const        { return false; }
 324   virtual bool is_Named_thread() const               { return false; }
 325   virtual bool is_Worker_thread() const              { return false; }
 326 
 327   // Casts
 328   virtual WorkerThread* as_Worker_thread() const     { return NULL; }
 329 
 330   virtual char* name() const { return (char*)"Unknown thread"; }
 331 
 332   // Returns the current thread
 333   static inline Thread* current();
 334   static inline Thread* current_or_null();
 335 
 336   // Common thread operations
 337   static void set_priority(Thread* thread, ThreadPriority priority);
 338   static ThreadPriority get_priority(const Thread* const thread);
 339   static void start(Thread* thread);
 340   static void interrupt(Thread* thr);
 341   static bool is_interrupted(Thread* thr, bool clear_interrupted);
 342 
 343   void set_native_thread_name(const char *name) {
 344     assert(Thread::current() == this, "set_native_thread_name can only be called on the current thread");
 345     os::set_native_thread_name(name);
 346   }
 347 
 348   ObjectMonitor** omInUseList_addr()             { return (ObjectMonitor **)&omInUseList; }
 349   Monitor* SR_lock() const                       { return _SR_lock; }
 350 
 351   bool has_async_exception() const { return (_suspend_flags & _has_async_exception) != 0; }
 352 
 353   void set_suspend_flag(SuspendFlags f) {
 354     assert(sizeof(jint) == sizeof(_suspend_flags), "size mismatch");
 355     uint32_t flags;
 356     do {
 357       flags = _suspend_flags;
 358     }
 359     while (Atomic::cmpxchg((jint)(flags | f),
 360                            (volatile jint*)&_suspend_flags,
 361                            (jint)flags) != (jint)flags);
 362   }
 363   void clear_suspend_flag(SuspendFlags f) {
 364     assert(sizeof(jint) == sizeof(_suspend_flags), "size mismatch");
 365     uint32_t flags;
 366     do {
 367       flags = _suspend_flags;
 368     }
 369     while (Atomic::cmpxchg((jint)(flags & ~f),
 370                            (volatile jint*)&_suspend_flags,
 371                            (jint)flags) != (jint)flags);
 372   }
 373 
 374   void set_has_async_exception() {
 375     set_suspend_flag(_has_async_exception);
 376   }
 377   void clear_has_async_exception() {
 378     clear_suspend_flag(_has_async_exception);
 379   }
 380 
 381   bool do_critical_native_unlock() const { return (_suspend_flags & _critical_native_unlock) != 0; }
 382 
 383   void set_critical_native_unlock() {
 384     set_suspend_flag(_critical_native_unlock);
 385   }
 386   void clear_critical_native_unlock() {
 387     clear_suspend_flag(_critical_native_unlock);
 388   }
 389 
 390   // Support for Unhandled Oop detection
 391 #ifdef CHECK_UNHANDLED_OOPS
 392  private:
 393   UnhandledOops* _unhandled_oops;
 394  public:
 395   UnhandledOops* unhandled_oops() { return _unhandled_oops; }
 396   // Mark oop safe for gc.  It may be stack allocated but won't move.
 397   void allow_unhandled_oop(oop *op) {
 398     if (CheckUnhandledOops) unhandled_oops()->allow_unhandled_oop(op);
 399   }
 400   // Clear oops at safepoint so crashes point to unhandled oop violator
 401   void clear_unhandled_oops() {
 402     if (CheckUnhandledOops) unhandled_oops()->clear_unhandled_oops();
 403   }
 404 #endif // CHECK_UNHANDLED_OOPS
 405 
 406 #ifndef PRODUCT
 407   bool skip_gcalot()           { return _skip_gcalot; }
 408   void set_skip_gcalot(bool v) { _skip_gcalot = v;    }
 409 #endif
 410 
 411  public:
 412   // Installs a pending exception to be inserted later
 413   static void send_async_exception(oop thread_oop, oop java_throwable);
 414 
 415   // Resource area
 416   ResourceArea* resource_area() const            { return _resource_area; }
 417   void set_resource_area(ResourceArea* area)     { _resource_area = area; }
 418 
 419   OSThread* osthread() const                     { return _osthread;   }
 420   void set_osthread(OSThread* thread)            { _osthread = thread; }
 421 
 422   // JNI handle support
 423   JNIHandleBlock* active_handles() const         { return _active_handles; }
 424   void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
 425   JNIHandleBlock* free_handle_block() const      { return _free_handle_block; }
 426   void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
 427 
 428   // Internal handle support
 429   HandleArea* handle_area() const                { return _handle_area; }
 430   void set_handle_area(HandleArea* area)         { _handle_area = area; }
 431 
 432   GrowableArray<Metadata*>* metadata_handles() const          { return _metadata_handles; }
 433   void set_metadata_handles(GrowableArray<Metadata*>* handles){ _metadata_handles = handles; }
 434 
 435   // Thread-Local Allocation Buffer (TLAB) support
 436   ThreadLocalAllocBuffer& tlab()                 { return _tlab; }
 437   void initialize_tlab() {
 438     if (UseTLAB) {
 439       tlab().initialize();
 440     }
 441   }
 442 
 443   jlong allocated_bytes()               { return _allocated_bytes; }
 444   void set_allocated_bytes(jlong value) { _allocated_bytes = value; }
 445   void incr_allocated_bytes(jlong size) { _allocated_bytes += size; }
 446   inline jlong cooked_allocated_bytes();
 447 
 448   JFR_ONLY(DEFINE_THREAD_LOCAL_ACCESSOR_JFR;)
 449   JFR_ONLY(DEFINE_TRACE_SUSPEND_FLAG_METHODS)
 450 
 451   const ThreadExt& ext() const          { return _ext; }
 452   ThreadExt& ext()                      { return _ext; }
 453 
 454   // VM operation support
 455   int vm_operation_ticket()                      { return ++_vm_operation_started_count; }
 456   int vm_operation_completed_count()             { return _vm_operation_completed_count; }
 457   void increment_vm_operation_completed_count()  { _vm_operation_completed_count++; }
 458 
 459   // For tracking the heavyweight monitor the thread is pending on.
 460   ObjectMonitor* current_pending_monitor() {
 461     return _current_pending_monitor;
 462   }
 463   void set_current_pending_monitor(ObjectMonitor* monitor) {
 464     _current_pending_monitor = monitor;
 465   }
 466   void set_current_pending_monitor_is_from_java(bool from_java) {
 467     _current_pending_monitor_is_from_java = from_java;
 468   }
 469   bool current_pending_monitor_is_from_java() {
 470     return _current_pending_monitor_is_from_java;
 471   }
 472 
 473   // For tracking the ObjectMonitor on which this thread called Object.wait()
 474   ObjectMonitor* current_waiting_monitor() {
 475     return _current_waiting_monitor;
 476   }
 477   void set_current_waiting_monitor(ObjectMonitor* monitor) {
 478     _current_waiting_monitor = monitor;
 479   }
 480 
 481   // GC support
 482   // Apply "f->do_oop" to all root oops in "this".
 483   // Apply "cld_f->do_cld" to CLDs that are otherwise not kept alive.
 484   //   Used by JavaThread::oops_do.
 485   // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames
 486   virtual void oops_do(OopClosure* f, CLDClosure* cld_f, CodeBlobClosure* cf);
 487 
 488   // Handles the parallel case for the method below.
 489 private:
 490   bool claim_oops_do_par_case(int collection_parity);
 491 public:
 492   // Requires that "collection_parity" is that of the current roots
 493   // iteration.  If "is_par" is false, sets the parity of "this" to
 494   // "collection_parity", and returns "true".  If "is_par" is true,
 495   // uses an atomic instruction to set the current threads parity to
 496   // "collection_parity", if it is not already.  Returns "true" iff the
 497   // calling thread does the update, this indicates that the calling thread
 498   // has claimed the thread's stack as a root groop in the current
 499   // collection.
 500   bool claim_oops_do(bool is_par, int collection_parity) {
 501     if (!is_par) {
 502       _oops_do_parity = collection_parity;
 503       return true;
 504     } else {
 505       return claim_oops_do_par_case(collection_parity);
 506     }
 507   }
 508 
 509   // Sweeper support
 510   void nmethods_do(CodeBlobClosure* cf);
 511 
 512   // jvmtiRedefineClasses support
 513   void metadata_do(void f(Metadata*));
 514 
 515   // Used by fast lock support
 516   virtual bool is_lock_owned(address adr) const;
 517 
 518   // Check if address is in the stack of the thread (not just for locks).
 519   // Warning: the method can only be used on the running thread
 520   bool is_in_stack(address adr) const;
 521   // Check if address is in the usable part of the stack (excludes protected
 522   // guard pages)
 523   bool is_in_usable_stack(address adr) const;
 524 
 525   // Sets this thread as starting thread. Returns failure if thread
 526   // creation fails due to lack of memory, too many threads etc.
 527   bool set_as_starting_thread();
 528 
 529   void set_metadata_on_stack_buffer(MetadataOnStackBuffer* buffer) { _metadata_on_stack_buffer = buffer; }
 530   MetadataOnStackBuffer* metadata_on_stack_buffer() const          { return _metadata_on_stack_buffer; }
 531 
 532 protected:
 533   // OS data associated with the thread
 534   OSThread* _osthread;  // Platform-specific thread information
 535 
 536   // Thread local resource area for temporary allocation within the VM
 537   ResourceArea* _resource_area;
 538 
 539   DEBUG_ONLY(ResourceMark* _current_resource_mark;)
 540 
 541   // Thread local handle area for allocation of handles within the VM
 542   HandleArea* _handle_area;
 543   GrowableArray<Metadata*>* _metadata_handles;
 544 
 545   // Support for stack overflow handling, get_thread, etc.
 546   address          _stack_base;
 547   size_t           _stack_size;
 548   uintptr_t        _self_raw_id;      // used by get_thread (mutable)
 549   int              _lgrp_id;
 550 
 551  public:
 552   // Stack overflow support
 553   address stack_base() const           { assert(_stack_base != NULL,"Sanity check"); return _stack_base; }
 554 
 555   void    set_stack_base(address base) { _stack_base = base; }
 556   size_t  stack_size() const           { return _stack_size; }
 557   void    set_stack_size(size_t size)  { _stack_size = size; }
 558   void    record_stack_base_and_size();
 559 
 560   bool    on_local_stack(address adr) const {
 561     /* QQQ this has knowledge of direction, ought to be a stack method */
 562     return (_stack_base > adr && adr >= (_stack_base - _stack_size));
 563   }
 564 
 565   uintptr_t self_raw_id()                    { return _self_raw_id; }
 566   void      set_self_raw_id(uintptr_t value) { _self_raw_id = value; }
 567 
 568   int     lgrp_id() const        { return _lgrp_id; }
 569   void    set_lgrp_id(int value) { _lgrp_id = value; }
 570 
 571   // Printing
 572   void print_on(outputStream* st) const;
 573   void print() const { print_on(tty); }
 574   virtual void print_on_error(outputStream* st, char* buf, int buflen) const;
 575 
 576   // Debug-only code
 577 #ifdef ASSERT
 578  private:
 579   // Deadlock detection support for Mutex locks. List of locks own by thread.
 580   Monitor* _owned_locks;
 581   // Mutex::set_owner_implementation is the only place where _owned_locks is modified,
 582   // thus the friendship
 583   friend class Mutex;
 584   friend class Monitor;
 585 
 586  public:
 587   void print_owned_locks_on(outputStream* st) const;
 588   void print_owned_locks() const                 { print_owned_locks_on(tty);    }
 589   Monitor* owned_locks() const                   { return _owned_locks;          }
 590   bool owns_locks() const                        { return owned_locks() != NULL; }
 591   bool owns_locks_but_compiled_lock() const;
 592 
 593   // Deadlock detection
 594   bool allow_allocation()                        { return _allow_allocation_count == 0; }
 595   ResourceMark* current_resource_mark()          { return _current_resource_mark; }
 596   void set_current_resource_mark(ResourceMark* rm) { _current_resource_mark = rm; }
 597 #endif
 598 
 599   void check_for_valid_safepoint_state(bool potential_vm_operation) PRODUCT_RETURN;
 600 
 601  private:
 602   volatile int _jvmti_env_iteration_count;
 603 
 604  public:
 605   void entering_jvmti_env_iteration()            { ++_jvmti_env_iteration_count; }
 606   void leaving_jvmti_env_iteration()             { --_jvmti_env_iteration_count; }
 607   bool is_inside_jvmti_env_iteration()           { return _jvmti_env_iteration_count > 0; }
 608 
 609   // Code generation
 610   static ByteSize exception_file_offset()        { return byte_offset_of(Thread, _exception_file   ); }
 611   static ByteSize exception_line_offset()        { return byte_offset_of(Thread, _exception_line   ); }
 612   static ByteSize active_handles_offset()        { return byte_offset_of(Thread, _active_handles   ); }
 613 
 614   static ByteSize stack_base_offset()            { return byte_offset_of(Thread, _stack_base ); }
 615   static ByteSize stack_size_offset()            { return byte_offset_of(Thread, _stack_size ); }
 616 
 617 #define TLAB_FIELD_OFFSET(name) \
 618   static ByteSize tlab_##name##_offset()         { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::name##_offset(); }
 619 
 620   TLAB_FIELD_OFFSET(start)
 621   TLAB_FIELD_OFFSET(end)
 622   TLAB_FIELD_OFFSET(top)
 623   TLAB_FIELD_OFFSET(pf_top)
 624   TLAB_FIELD_OFFSET(size)                   // desired_size
 625   TLAB_FIELD_OFFSET(refill_waste_limit)
 626   TLAB_FIELD_OFFSET(number_of_refills)
 627   TLAB_FIELD_OFFSET(fast_refill_waste)
 628   TLAB_FIELD_OFFSET(slow_allocations)
 629 
 630 #undef TLAB_FIELD_OFFSET
 631 
 632   static ByteSize allocated_bytes_offset()       { return byte_offset_of(Thread, _allocated_bytes ); }
 633 
 634   JFR_ONLY(DEFINE_THREAD_LOCAL_OFFSET_JFR;)
 635 
 636  public:
 637   volatile intptr_t _Stalled ;
 638   volatile int _TypeTag ;
 639   ParkEvent * _ParkEvent ;                     // for synchronized()
 640   ParkEvent * _SleepEvent ;                    // for Thread.sleep
 641   ParkEvent * _MutexEvent ;                    // for native internal Mutex/Monitor
 642   ParkEvent * _MuxEvent ;                      // for low-level muxAcquire-muxRelease
 643   int NativeSyncRecursion ;                    // diagnostic
 644 
 645   volatile int _OnTrap ;                       // Resume-at IP delta
 646   jint _hashStateW ;                           // Marsaglia Shift-XOR thread-local RNG
 647   jint _hashStateX ;                           // thread-specific hashCode generator state
 648   jint _hashStateY ;
 649   jint _hashStateZ ;
 650   void * _schedctl ;
 651 
 652 
 653   volatile jint rng [4] ;                      // RNG for spin loop
 654 
 655   // Low-level leaf-lock primitives used to implement synchronization
 656   // and native monitor-mutex infrastructure.
 657   // Not for general synchronization use.
 658   static void SpinAcquire (volatile int * Lock, const char * Name) ;
 659   static void SpinRelease (volatile int * Lock) ;
 660   static void muxAcquire  (volatile intptr_t * Lock, const char * Name) ;
 661   static void muxAcquireW (volatile intptr_t * Lock, ParkEvent * ev) ;
 662   static void muxRelease  (volatile intptr_t * Lock) ;
 663 };
 664 
 665 // Inline implementation of Thread::current()
 666 // Thread::current is "hot" it's called > 128K times in the 1st 500 msecs of
 667 // startup.
 668 // ThreadLocalStorage::thread is warm -- it's called > 16K times in the same
 669 // period.   This is inlined in thread_<os_family>.inline.hpp.
 670 
 671 inline Thread* Thread::current() {
 672 #ifdef ASSERT
 673 // This function is very high traffic. Define PARANOID to enable expensive
 674 // asserts.
 675 #ifdef PARANOID
 676   // Signal handler should call ThreadLocalStorage::get_thread_slow()
 677   Thread* t = ThreadLocalStorage::get_thread_slow();
 678   assert(t != NULL && !t->is_inside_signal_handler(),
 679          "Don't use Thread::current() inside signal handler");
 680 #endif
 681 #endif
 682   Thread* current = current_or_null();
 683   assert(current != NULL, "Thread::current() called on detached thread");
 684   return current;
 685 }
 686 
 687 inline Thread* Thread::current_or_null() {
 688   if (ThreadLocalStorage::is_initialized()) {
 689     return ThreadLocalStorage::thread();
 690   }
 691   return NULL;
 692 }
 693 
 694 // Name support for threads.  non-JavaThread subclasses with multiple
 695 // uniquely named instances should derive from this.
 696 class NamedThread: public Thread {
 697   friend class VMStructs;
 698   enum {
 699     max_name_len = 64
 700   };
 701  private:
 702   char* _name;
 703   // log JavaThread being processed by oops_do
 704   JavaThread* _processed_thread;
 705 
 706  public:
 707   NamedThread();
 708   ~NamedThread();
 709   // May only be called once per thread.
 710   void set_name(const char* format, ...)  ATTRIBUTE_PRINTF(2, 3);
 711   virtual bool is_Named_thread() const { return true; }
 712   virtual char* name() const { return _name == NULL ? (char*)"Unknown Thread" : _name; }
 713   JavaThread *processed_thread() { return _processed_thread; }
 714   void set_processed_thread(JavaThread *thread) { _processed_thread = thread; }
 715 };
 716 
 717 // Worker threads are named and have an id of an assigned work.
 718 class WorkerThread: public NamedThread {
 719 private:
 720   uint _id;
 721 public:
 722   WorkerThread() : _id(0)               { }
 723   virtual bool is_Worker_thread() const { return true; }
 724 
 725   virtual WorkerThread* as_Worker_thread() const {
 726     assert(is_Worker_thread(), "Dubious cast to WorkerThread*?");
 727     return (WorkerThread*) this;
 728   }
 729 
 730   void set_id(uint work_id)             { _id = work_id; }
 731   uint id() const                       { return _id; }
 732 };
 733 
 734 // A single WatcherThread is used for simulating timer interrupts.
 735 class WatcherThread: public Thread {
 736   friend class VMStructs;
 737  public:
 738   virtual void run();
 739 
 740  private:
 741   static WatcherThread* _watcher_thread;
 742 
 743   static bool _startable;
 744   volatile static bool _should_terminate; // updated without holding lock
 745  public:
 746   enum SomeConstants {
 747     delay_interval = 10                          // interrupt delay in milliseconds
 748   };
 749 
 750   // Constructor
 751   WatcherThread();
 752 
 753   // Tester
 754   bool is_Watcher_thread() const                 { return true; }
 755 
 756   // Printing
 757   char* name() const { return (char*)"VM Periodic Task Thread"; }
 758   void print_on(outputStream* st) const;
 759   void print() const { print_on(tty); }
 760   void unpark();
 761 
 762   // Returns the single instance of WatcherThread
 763   static WatcherThread* watcher_thread()         { return _watcher_thread; }
 764 
 765   // Create and start the single instance of WatcherThread, or stop it on shutdown
 766   static void start();
 767   static void stop();
 768   // Only allow start once the VM is sufficiently initialized
 769   // Otherwise the first task to enroll will trigger the start
 770   static void make_startable();
 771  private:
 772   int sleep() const;
 773 };
 774 
 775 
 776 class CompilerThread;
 777 
 778 typedef void (*ThreadFunction)(JavaThread*, TRAPS);
 779 
 780 class JavaThread: public Thread {
 781   friend class VMStructs;
 782  private:
 783   JavaThread*    _next;                          // The next thread in the Threads list
 784   oop            _threadObj;                     // The Java level thread object
 785 
 786 #ifdef ASSERT
 787  private:
 788   int _java_call_counter;
 789 
 790  public:
 791   int  java_call_counter()                       { return _java_call_counter; }
 792   void inc_java_call_counter()                   { _java_call_counter++; }
 793   void dec_java_call_counter() {
 794     assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
 795     _java_call_counter--;
 796   }
 797  private:  // restore original namespace restriction
 798 #endif  // ifdef ASSERT
 799 
 800 #ifndef PRODUCT
 801  public:
 802   enum {
 803     jump_ring_buffer_size = 16
 804   };
 805  private:  // restore original namespace restriction
 806 #endif
 807 
 808   JavaFrameAnchor _anchor;                       // Encapsulation of current java frame and it state
 809 
 810   ThreadFunction _entry_point;
 811 
 812   JNIEnv        _jni_environment;
 813 
 814   // Deopt support
 815   DeoptResourceMark*  _deopt_mark;               // Holds special ResourceMark for deoptimization
 816 
 817   intptr_t*      _must_deopt_id;                 // id of frame that needs to be deopted once we
 818                                                  // transition out of native
 819   nmethod*       _deopt_nmethod;                 // nmethod that is currently being deoptimized
 820   vframeArray*  _vframe_array_head;              // Holds the heap of the active vframeArrays
 821   vframeArray*  _vframe_array_last;              // Holds last vFrameArray we popped
 822   // Because deoptimization is lazy we must save jvmti requests to set locals
 823   // in compiled frames until we deoptimize and we have an interpreter frame.
 824   // This holds the pointer to array (yeah like there might be more than one) of
 825   // description of compiled vframes that have locals that need to be updated.
 826   GrowableArray<jvmtiDeferredLocalVariableSet*>* _deferred_locals_updates;
 827 
 828   // Handshake value for fixing 6243940. We need a place for the i2c
 829   // adapter to store the callee Method*. This value is NEVER live
 830   // across a gc point so it does NOT have to be gc'd
 831   // The handshake is open ended since we can't be certain that it will
 832   // be NULLed. This is because we rarely ever see the race and end up
 833   // in handle_wrong_method which is the backend of the handshake. See
 834   // code in i2c adapters and handle_wrong_method.
 835 
 836   Method*       _callee_target;
 837 
 838   // Used to pass back results to the interpreter or generated code running Java code.
 839   oop           _vm_result;    // oop result is GC-preserved
 840   Metadata*     _vm_result_2;  // non-oop result
 841 
 842   // See ReduceInitialCardMarks: this holds the precise space interval of
 843   // the most recent slow path allocation for which compiled code has
 844   // elided card-marks for performance along the fast-path.
 845   MemRegion     _deferred_card_mark;
 846 
 847   MonitorChunk* _monitor_chunks;                 // Contains the off stack monitors
 848                                                  // allocated during deoptimization
 849                                                  // and by JNI_MonitorEnter/Exit
 850 
 851   // Async. requests support
 852   enum AsyncRequests {
 853     _no_async_condition = 0,
 854     _async_exception,
 855     _async_unsafe_access_error
 856   };
 857   AsyncRequests _special_runtime_exit_condition; // Enum indicating pending async. request
 858   oop           _pending_async_exception;
 859 
 860   // Safepoint support
 861  public:                                         // Expose _thread_state for SafeFetchInt()
 862   volatile JavaThreadState _thread_state;
 863  private:
 864   ThreadSafepointState *_safepoint_state;        // Holds information about a thread during a safepoint
 865   address               _saved_exception_pc;     // Saved pc of instruction where last implicit exception happened
 866 
 867   // JavaThread termination support
 868   enum TerminatedTypes {
 869     _not_terminated = 0xDEAD - 2,
 870     _thread_exiting,                             // JavaThread::exit() has been called for this thread
 871     _thread_terminated,                          // JavaThread is removed from thread list
 872     _vm_exited                                   // JavaThread is still executing native code, but VM is terminated
 873                                                  // only VM_Exit can set _vm_exited
 874   };
 875 
 876   // In general a JavaThread's _terminated field transitions as follows:
 877   //
 878   //   _not_terminated => _thread_exiting => _thread_terminated
 879   //
 880   // _vm_exited is a special value to cover the case of a JavaThread
 881   // executing native code after the VM itself is terminated.
 882   volatile TerminatedTypes _terminated;
 883   // suspend/resume support
 884   volatile bool         _suspend_equivalent;     // Suspend equivalent condition
 885   jint                  _in_deopt_handler;       // count of deoptimization
 886                                                  // handlers thread is in
 887   volatile bool         _doing_unsafe_access;    // Thread may fault due to unsafe access
 888   bool                  _do_not_unlock_if_synchronized; // Do not unlock the receiver of a synchronized method (since it was
 889                                                  // never locked) when throwing an exception. Used by interpreter only.
 890 
 891   // JNI attach states:
 892   enum JNIAttachStates {
 893     _not_attaching_via_jni = 1,  // thread is not attaching via JNI
 894     _attaching_via_jni,          // thread is attaching via JNI
 895     _attached_via_jni            // thread has attached via JNI
 896   };
 897 
 898   // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
 899   // A native thread that is attaching via JNI starts with a value
 900   // of _attaching_via_jni and transitions to _attached_via_jni.
 901   volatile JNIAttachStates _jni_attach_state;
 902 
 903  public:
 904   // State of the stack guard pages for this thread.
 905   enum StackGuardState {
 906     stack_guard_unused,         // not needed
 907     stack_guard_yellow_disabled,// disabled (temporarily) after stack overflow
 908     stack_guard_enabled         // enabled
 909   };
 910 
 911  private:
 912 
 913   StackGuardState  _stack_guard_state;
 914 
 915   // Precompute the limit of the stack as used in stack overflow checks.
 916   // We load it from here to simplify the stack overflow check in assembly.
 917   address          _stack_overflow_limit;
 918 
 919   // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
 920   // used to temp. parsing values into and out of the runtime system during exception handling for compiled
 921   // code)
 922   volatile oop     _exception_oop;               // Exception thrown in compiled code
 923   volatile address _exception_pc;                // PC where exception happened
 924   volatile address _exception_handler_pc;        // PC for handler of exception
 925   volatile int     _is_method_handle_return;     // true (== 1) if the current exception PC is a MethodHandle call site.
 926 
 927   // support for JNI critical regions
 928   jint    _jni_active_critical;                  // count of entries into JNI critical region
 929 
 930   // Checked JNI: function name requires exception check
 931   char* _pending_jni_exception_check_fn;
 932 
 933   // For deadlock detection.
 934   int _depth_first_number;
 935 
 936   // JVMTI PopFrame support
 937   // This is set to popframe_pending to signal that top Java frame should be popped immediately
 938   int _popframe_condition;
 939 
 940   // If reallocation of scalar replaced objects fails, we throw OOM
 941   // and during exception propagation, pop the top
 942   // _frames_to_pop_failed_realloc frames, the ones that reference
 943   // failed reallocations.
 944   int _frames_to_pop_failed_realloc;
 945 
 946 #ifndef PRODUCT
 947   int _jmp_ring_index;
 948   struct {
 949       // We use intptr_t instead of address so debugger doesn't try and display strings
 950       intptr_t _target;
 951       intptr_t _instruction;
 952       const char*  _file;
 953       int _line;
 954   }   _jmp_ring[ jump_ring_buffer_size ];
 955 #endif /* PRODUCT */
 956 
 957 #if INCLUDE_ALL_GCS
 958   // Support for G1 barriers
 959 
 960   ObjPtrQueue _satb_mark_queue;          // Thread-local log for SATB barrier.
 961   // Set of all such queues.
 962   static SATBMarkQueueSet _satb_mark_queue_set;
 963 
 964   DirtyCardQueue _dirty_card_queue;      // Thread-local log for dirty cards.
 965   // Set of all such queues.
 966   static DirtyCardQueueSet _dirty_card_queue_set;
 967 
 968   void flush_barrier_queues();
 969 #endif // INCLUDE_ALL_GCS
 970 
 971   friend class VMThread;
 972   friend class ThreadWaitTransition;
 973   friend class VM_Exit;
 974 
 975   void initialize();                             // Initialized the instance variables
 976 
 977  public:
 978   // Constructor
 979   JavaThread(bool is_attaching_via_jni = false); // for main thread and JNI attached threads
 980   JavaThread(ThreadFunction entry_point, size_t stack_size = 0);
 981   ~JavaThread();
 982 
 983 #ifdef ASSERT
 984   // verify this JavaThread hasn't be published in the Threads::list yet
 985   void verify_not_published();
 986 #endif
 987 
 988   //JNI functiontable getter/setter for JVMTI jni function table interception API.
 989   void set_jni_functions(struct JNINativeInterface_* functionTable) {
 990     _jni_environment.functions = functionTable;
 991   }
 992   struct JNINativeInterface_* get_jni_functions() {
 993     return (struct JNINativeInterface_ *)_jni_environment.functions;
 994   }
 995 
 996   // This function is called at thread creation to allow
 997   // platform specific thread variables to be initialized.
 998   void cache_global_variables();
 999 
1000   // Executes Shutdown.shutdown()
1001   void invoke_shutdown_hooks();
1002 
1003   // Cleanup on thread exit
1004   enum ExitType {
1005     normal_exit,
1006     jni_detach
1007   };
1008   void exit(bool destroy_vm, ExitType exit_type = normal_exit);
1009 
1010   void cleanup_failed_attach_current_thread();
1011 
1012   // Testers
1013   virtual bool is_Java_thread() const            { return true;  }
1014 
1015   // Thread chain operations
1016   JavaThread* next() const                       { return _next; }
1017   void set_next(JavaThread* p)                   { _next = p; }
1018 
1019   // Thread oop. threadObj() can be NULL for initial JavaThread
1020   // (or for threads attached via JNI)
1021   oop threadObj() const                          { return _threadObj; }
1022   void set_threadObj(oop p)                      { _threadObj = p; }
1023 
1024   ThreadPriority java_priority() const;          // Read from threadObj()
1025 
1026   // Prepare thread and add to priority queue.  If a priority is
1027   // not specified, use the priority of the thread object. Threads_lock
1028   // must be held while this function is called.
1029   void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
1030   void prepare_ext();
1031 
1032   void set_saved_exception_pc(address pc)        { _saved_exception_pc = pc; }
1033   address saved_exception_pc()                   { return _saved_exception_pc; }
1034 
1035 
1036   ThreadFunction entry_point() const             { return _entry_point; }
1037 
1038   // Allocates a new Java level thread object for this thread. thread_name may be NULL.
1039   void allocate_threadObj(Handle thread_group, char* thread_name, bool daemon, TRAPS);
1040 
1041   // Last frame anchor routines
1042 
1043   JavaFrameAnchor* frame_anchor(void)            { return &_anchor; }
1044 
1045   // last_Java_sp
1046   bool has_last_Java_frame() const               { return _anchor.has_last_Java_frame(); }
1047   intptr_t* last_Java_sp() const                 { return _anchor.last_Java_sp(); }
1048 
1049   // last_Java_pc
1050 
1051   address last_Java_pc(void)                     { return _anchor.last_Java_pc(); }
1052 
1053   // Safepoint support
1054 #if !(defined(PPC64) || defined(AARCH64))
1055   JavaThreadState thread_state() const           { return _thread_state; }
1056   void set_thread_state(JavaThreadState s)       { _thread_state = s;    }
1057 #else
1058   // Use membars when accessing volatile _thread_state. See
1059   // Threads::create_vm() for size checks.
1060   inline JavaThreadState thread_state() const;
1061   inline void set_thread_state(JavaThreadState s);
1062 #endif
1063   ThreadSafepointState *safepoint_state() const  { return _safepoint_state; }
1064   void set_safepoint_state(ThreadSafepointState *state) { _safepoint_state = state; }
1065   bool is_at_poll_safepoint()                    { return _safepoint_state->is_at_poll_safepoint(); }
1066 
1067   // thread has called JavaThread::exit() or is terminated
1068   bool is_exiting()                              { return _terminated == _thread_exiting || is_terminated(); }
1069   // thread is terminated (no longer on the threads list); we compare
1070   // against the two non-terminated values so that a freed JavaThread
1071   // will also be considered terminated.
1072   bool is_terminated()                           { return _terminated != _not_terminated && _terminated != _thread_exiting; }
1073   void set_terminated(TerminatedTypes t)         { _terminated = t; }
1074   // special for Threads::remove() which is static:
1075   void set_terminated_value()                    { _terminated = _thread_terminated; }
1076   void block_if_vm_exited();
1077 
1078   bool doing_unsafe_access()                     { return _doing_unsafe_access; }
1079   void set_doing_unsafe_access(bool val)         { _doing_unsafe_access = val; }
1080 
1081   bool do_not_unlock_if_synchronized()             { return _do_not_unlock_if_synchronized; }
1082   void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
1083 
1084   // Suspend/resume support for JavaThread
1085  private:
1086   void set_ext_suspended()       { set_suspend_flag (_ext_suspended);  }
1087   void clear_ext_suspended()     { clear_suspend_flag(_ext_suspended); }
1088 
1089  public:
1090   void java_suspend();
1091   void java_resume();
1092   int  java_suspend_self();
1093 
1094   void check_and_wait_while_suspended() {
1095     assert(JavaThread::current() == this, "sanity check");
1096 
1097     bool do_self_suspend;
1098     do {
1099       // were we externally suspended while we were waiting?
1100       do_self_suspend = handle_special_suspend_equivalent_condition();
1101       if (do_self_suspend) {
1102         // don't surprise the thread that suspended us by returning
1103         java_suspend_self();
1104         set_suspend_equivalent();
1105       }
1106     } while (do_self_suspend);
1107   }
1108   static void check_safepoint_and_suspend_for_native_trans(JavaThread *thread);
1109   // Check for async exception in addition to safepoint and suspend request.
1110   static void check_special_condition_for_native_trans(JavaThread *thread);
1111 
1112   // Same as check_special_condition_for_native_trans but finishes the
1113   // transition into thread_in_Java mode so that it can potentially
1114   // block.
1115   static void check_special_condition_for_native_trans_and_transition(JavaThread *thread);
1116 
1117   bool is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits);
1118   bool is_ext_suspend_completed_with_lock(uint32_t *bits) {
1119     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1120     // Warning: is_ext_suspend_completed() may temporarily drop the
1121     // SR_lock to allow the thread to reach a stable thread state if
1122     // it is currently in a transient thread state.
1123     return is_ext_suspend_completed(false /*!called_by_wait */,
1124                                     SuspendRetryDelay, bits);
1125   }
1126 
1127   // We cannot allow wait_for_ext_suspend_completion() to run forever or
1128   // we could hang. SuspendRetryCount and SuspendRetryDelay are normally
1129   // passed as the count and delay parameters. Experiments with specific
1130   // calls to wait_for_ext_suspend_completion() can be done by passing
1131   // other values in the code. Experiments with all calls can be done
1132   // via the appropriate -XX options.
1133   bool wait_for_ext_suspend_completion(int count, int delay, uint32_t *bits);
1134 
1135   void set_external_suspend()     { set_suspend_flag  (_external_suspend); }
1136   void clear_external_suspend()   { clear_suspend_flag(_external_suspend); }
1137 
1138   void set_deopt_suspend()        { set_suspend_flag  (_deopt_suspend); }
1139   void clear_deopt_suspend()      { clear_suspend_flag(_deopt_suspend); }
1140   bool is_deopt_suspend()         { return (_suspend_flags & _deopt_suspend) != 0; }
1141 
1142   bool is_external_suspend() const {
1143     return (_suspend_flags & _external_suspend) != 0;
1144   }
1145   // Whenever a thread transitions from native to vm/java it must suspend
1146   // if external|deopt suspend is present.
1147   bool is_suspend_after_native() const {
1148     return (_suspend_flags & (_external_suspend | _deopt_suspend) ) != 0;
1149   }
1150 
1151   // external suspend request is completed
1152   bool is_ext_suspended() const {
1153     return (_suspend_flags & _ext_suspended) != 0;
1154   }
1155 
1156   bool is_external_suspend_with_lock() const {
1157     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1158     return is_external_suspend();
1159   }
1160 
1161   // Special method to handle a pending external suspend request
1162   // when a suspend equivalent condition lifts.
1163   bool handle_special_suspend_equivalent_condition() {
1164     assert(is_suspend_equivalent(),
1165       "should only be called in a suspend equivalence condition");
1166     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1167     bool ret = is_external_suspend();
1168     if (!ret) {
1169       // not about to self-suspend so clear suspend equivalence
1170       clear_suspend_equivalent();
1171     }
1172     // implied else:
1173     // We have a pending external suspend request so we leave the
1174     // suspend_equivalent flag set until java_suspend_self() sets
1175     // the ext_suspended flag and clears the suspend_equivalent
1176     // flag. This insures that wait_for_ext_suspend_completion()
1177     // will return consistent values.
1178     return ret;
1179   }
1180 
1181   // utility methods to see if we are doing some kind of suspension
1182   bool is_being_ext_suspended() const            {
1183     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1184     return is_ext_suspended() || is_external_suspend();
1185   }
1186 
1187   bool is_suspend_equivalent() const             { return _suspend_equivalent; }
1188 
1189   void set_suspend_equivalent()                  { _suspend_equivalent = true; };
1190   void clear_suspend_equivalent()                { _suspend_equivalent = false; };
1191 
1192   // Thread.stop support
1193   void send_thread_stop(oop throwable);
1194   AsyncRequests clear_special_runtime_exit_condition() {
1195     AsyncRequests x = _special_runtime_exit_condition;
1196     _special_runtime_exit_condition = _no_async_condition;
1197     return x;
1198   }
1199 
1200   // Are any async conditions present?
1201   bool has_async_condition() { return (_special_runtime_exit_condition != _no_async_condition); }
1202 
1203   void check_and_handle_async_exceptions(bool check_unsafe_error = true);
1204 
1205   // these next two are also used for self-suspension and async exception support
1206   void handle_special_runtime_exit_condition(bool check_asyncs = true);
1207 
1208   // Return true if JavaThread has an asynchronous condition or
1209   // if external suspension is requested.
1210   bool has_special_runtime_exit_condition() {
1211     // We call is_external_suspend() last since external suspend should
1212     // be less common. Because we don't use is_external_suspend_with_lock
1213     // it is possible that we won't see an asynchronous external suspend
1214     // request that has just gotten started, i.e., SR_lock grabbed but
1215     // _external_suspend field change either not made yet or not visible
1216     // yet. However, this is okay because the request is asynchronous and
1217     // we will see the new flag value the next time through. It's also
1218     // possible that the external suspend request is dropped after
1219     // we have checked is_external_suspend(), we will recheck its value
1220     // under SR_lock in java_suspend_self().
1221     return (_special_runtime_exit_condition != _no_async_condition) ||
1222             is_external_suspend() || is_deopt_suspend();
1223   }
1224 
1225   void set_pending_unsafe_access_error()          { _special_runtime_exit_condition = _async_unsafe_access_error; }
1226 
1227   void set_pending_async_exception(oop e) {
1228     _pending_async_exception = e;
1229     _special_runtime_exit_condition = _async_exception;
1230     set_has_async_exception();
1231   }
1232 
1233   // Fast-locking support
1234   bool is_lock_owned(address adr) const;
1235 
1236   // Accessors for vframe array top
1237   // The linked list of vframe arrays are sorted on sp. This means when we
1238   // unpack the head must contain the vframe array to unpack.
1239   void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
1240   vframeArray* vframe_array_head() const         { return _vframe_array_head;  }
1241 
1242   // Side structure for defering update of java frame locals until deopt occurs
1243   GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred_locals() const { return _deferred_locals_updates; }
1244   void set_deferred_locals(GrowableArray<jvmtiDeferredLocalVariableSet *>* vf) { _deferred_locals_updates = vf; }
1245 
1246   // These only really exist to make debugging deopt problems simpler
1247 
1248   void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
1249   vframeArray* vframe_array_last() const         { return _vframe_array_last;  }
1250 
1251   // The special resourceMark used during deoptimization
1252 
1253   void set_deopt_mark(DeoptResourceMark* value)  { _deopt_mark = value; }
1254   DeoptResourceMark* deopt_mark(void)            { return _deopt_mark; }
1255 
1256   intptr_t* must_deopt_id()                      { return _must_deopt_id; }
1257   void     set_must_deopt_id(intptr_t* id)       { _must_deopt_id = id; }
1258   void     clear_must_deopt_id()                 { _must_deopt_id = NULL; }
1259 
1260   void set_deopt_nmethod(nmethod* nm)            { _deopt_nmethod = nm;   }
1261   nmethod* deopt_nmethod()                       { return _deopt_nmethod; }
1262 
1263   Method*    callee_target() const               { return _callee_target; }
1264   void set_callee_target  (Method* x)          { _callee_target   = x; }
1265 
1266   // Oop results of vm runtime calls
1267   oop  vm_result() const                         { return _vm_result; }
1268   void set_vm_result  (oop x)                    { _vm_result   = x; }
1269 
1270   Metadata*    vm_result_2() const               { return _vm_result_2; }
1271   void set_vm_result_2  (Metadata* x)          { _vm_result_2   = x; }
1272 
1273   MemRegion deferred_card_mark() const           { return _deferred_card_mark; }
1274   void set_deferred_card_mark(MemRegion mr)      { _deferred_card_mark = mr;   }
1275 
1276   // Exception handling for compiled methods
1277   oop      exception_oop() const                 { return _exception_oop; }
1278   address  exception_pc() const                  { return _exception_pc; }
1279   address  exception_handler_pc() const          { return _exception_handler_pc; }
1280   bool     is_method_handle_return() const       { return _is_method_handle_return == 1; }
1281 
1282   void set_exception_oop(oop o)                  { (void)const_cast<oop&>(_exception_oop = o); }
1283   void set_exception_pc(address a)               { _exception_pc = a; }
1284   void set_exception_handler_pc(address a)       { _exception_handler_pc = a; }
1285   void set_is_method_handle_return(bool value)   { _is_method_handle_return = value ? 1 : 0; }
1286 
1287   void clear_exception_oop_and_pc() {
1288     set_exception_oop(NULL);
1289     set_exception_pc(NULL);
1290   }
1291 
1292   // Stack overflow support
1293   inline size_t stack_available(address cur_sp);
1294   address stack_yellow_zone_base()
1295     { return (address)(stack_base() - (stack_size() - (stack_red_zone_size() + stack_yellow_zone_size()))); }
1296   size_t  stack_yellow_zone_size()
1297     { return StackYellowPages * os::vm_page_size(); }
1298   address stack_red_zone_base()
1299     { return (address)(stack_base() - (stack_size() - stack_red_zone_size())); }
1300   size_t stack_red_zone_size()
1301     { return StackRedPages * os::vm_page_size(); }
1302   bool in_stack_yellow_zone(address a)
1303     { return (a <= stack_yellow_zone_base()) && (a >= stack_red_zone_base()); }
1304   bool in_stack_red_zone(address a)
1305     { return (a <= stack_red_zone_base()) && (a >= (address)((intptr_t)stack_base() - stack_size())); }
1306 
1307   void create_stack_guard_pages();
1308   void remove_stack_guard_pages();
1309 
1310   void enable_stack_yellow_zone();
1311   void disable_stack_yellow_zone();
1312   void enable_stack_red_zone();
1313   void disable_stack_red_zone();
1314 
1315   inline bool stack_guard_zone_unused();
1316   inline bool stack_yellow_zone_disabled();
1317   inline bool stack_yellow_zone_enabled();
1318 
1319   // Attempt to reguard the stack after a stack overflow may have occurred.
1320   // Returns true if (a) guard pages are not needed on this thread, (b) the
1321   // pages are already guarded, or (c) the pages were successfully reguarded.
1322   // Returns false if there is not enough stack space to reguard the pages, in
1323   // which case the caller should unwind a frame and try again.  The argument
1324   // should be the caller's (approximate) sp.
1325   bool reguard_stack(address cur_sp);
1326   // Similar to above but see if current stackpoint is out of the guard area
1327   // and reguard if possible.
1328   bool reguard_stack(void);
1329 
1330   address stack_overflow_limit() { return _stack_overflow_limit; }
1331   void set_stack_overflow_limit() {
1332     _stack_overflow_limit = _stack_base - _stack_size +
1333                             ((StackShadowPages +
1334                               StackYellowPages +
1335                               StackRedPages) * os::vm_page_size());
1336   }
1337 
1338   // Misc. accessors/mutators
1339   void set_do_not_unlock(void)                   { _do_not_unlock_if_synchronized = true; }
1340   void clr_do_not_unlock(void)                   { _do_not_unlock_if_synchronized = false; }
1341   bool do_not_unlock(void)                       { return _do_not_unlock_if_synchronized; }
1342 
1343 #ifndef PRODUCT
1344   void record_jump(address target, address instr, const char* file, int line);
1345 #endif /* PRODUCT */
1346 
1347   // For assembly stub generation
1348   static ByteSize threadObj_offset()             { return byte_offset_of(JavaThread, _threadObj           ); }
1349 #ifndef PRODUCT
1350   static ByteSize jmp_ring_index_offset()        { return byte_offset_of(JavaThread, _jmp_ring_index      ); }
1351   static ByteSize jmp_ring_offset()              { return byte_offset_of(JavaThread, _jmp_ring            ); }
1352 #endif /* PRODUCT */
1353   static ByteSize jni_environment_offset()       { return byte_offset_of(JavaThread, _jni_environment     ); }
1354   static ByteSize last_Java_sp_offset()          {
1355     return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
1356   }
1357   static ByteSize last_Java_pc_offset()          {
1358     return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
1359   }
1360   static ByteSize frame_anchor_offset()          {
1361     return byte_offset_of(JavaThread, _anchor);
1362   }
1363   static ByteSize callee_target_offset()         { return byte_offset_of(JavaThread, _callee_target       ); }
1364   static ByteSize vm_result_offset()             { return byte_offset_of(JavaThread, _vm_result           ); }
1365   static ByteSize vm_result_2_offset()           { return byte_offset_of(JavaThread, _vm_result_2         ); }
1366   static ByteSize thread_state_offset()          { return byte_offset_of(JavaThread, _thread_state        ); }
1367   static ByteSize saved_exception_pc_offset()    { return byte_offset_of(JavaThread, _saved_exception_pc  ); }
1368   static ByteSize osthread_offset()              { return byte_offset_of(JavaThread, _osthread            ); }
1369   static ByteSize exception_oop_offset()         { return byte_offset_of(JavaThread, _exception_oop       ); }
1370   static ByteSize exception_pc_offset()          { return byte_offset_of(JavaThread, _exception_pc        ); }
1371   static ByteSize exception_handler_pc_offset()  { return byte_offset_of(JavaThread, _exception_handler_pc); }
1372   static ByteSize stack_overflow_limit_offset()  { return byte_offset_of(JavaThread, _stack_overflow_limit); }
1373   static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); }
1374   static ByteSize stack_guard_state_offset()     { return byte_offset_of(JavaThread, _stack_guard_state   ); }
1375   static ByteSize suspend_flags_offset()         { return byte_offset_of(JavaThread, _suspend_flags       ); }
1376 
1377   static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
1378   static ByteSize should_post_on_exceptions_flag_offset() {
1379     return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
1380   }
1381 
1382 #if INCLUDE_ALL_GCS
1383   static ByteSize satb_mark_queue_offset()       { return byte_offset_of(JavaThread, _satb_mark_queue); }
1384   static ByteSize dirty_card_queue_offset()      { return byte_offset_of(JavaThread, _dirty_card_queue); }
1385 #endif // INCLUDE_ALL_GCS
1386 
1387   // Returns the jni environment for this thread
1388   JNIEnv* jni_environment()                      { return &_jni_environment; }
1389 
1390   static JavaThread* thread_from_jni_environment(JNIEnv* env) {
1391     JavaThread *thread_from_jni_env = (JavaThread*)((intptr_t)env - in_bytes(jni_environment_offset()));
1392     // Only return NULL if thread is off the thread list; starting to
1393     // exit should not return NULL.
1394     if (thread_from_jni_env->is_terminated()) {
1395        thread_from_jni_env->block_if_vm_exited();
1396        return NULL;
1397     } else {
1398        return thread_from_jni_env;
1399     }
1400   }
1401 
1402   // JNI critical regions. These can nest.
1403   bool in_critical()    { return _jni_active_critical > 0; }
1404   bool in_last_critical()  { return _jni_active_critical == 1; }
1405   void enter_critical() { assert(Thread::current() == this ||
1406                                  Thread::current()->is_VM_thread() && SafepointSynchronize::is_synchronizing(),
1407                                  "this must be current thread or synchronizing");
1408                           _jni_active_critical++; }
1409   void exit_critical()  { assert(Thread::current() == this,
1410                                  "this must be current thread");
1411                           _jni_active_critical--;
1412                           assert(_jni_active_critical >= 0,
1413                                  "JNI critical nesting problem?"); }
1414 
1415   // Checked JNI, is the programmer required to check for exceptions, specify which function name
1416   bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != NULL; }
1417   void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = NULL; }
1418   const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; }
1419   void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; }
1420 
1421   // For deadlock detection
1422   int depth_first_number() { return _depth_first_number; }
1423   void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
1424 
1425  private:
1426   void set_monitor_chunks(MonitorChunk* monitor_chunks) { _monitor_chunks = monitor_chunks; }
1427 
1428  public:
1429   MonitorChunk* monitor_chunks() const           { return _monitor_chunks; }
1430   void add_monitor_chunk(MonitorChunk* chunk);
1431   void remove_monitor_chunk(MonitorChunk* chunk);
1432   bool in_deopt_handler() const                  { return _in_deopt_handler > 0; }
1433   void inc_in_deopt_handler()                    { _in_deopt_handler++; }
1434   void dec_in_deopt_handler()                    {
1435     assert(_in_deopt_handler > 0, "mismatched deopt nesting");
1436     if (_in_deopt_handler > 0) { // robustness
1437       _in_deopt_handler--;
1438     }
1439   }
1440 
1441  private:
1442   void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
1443 
1444  public:
1445 
1446   // Frame iteration; calls the function f for all frames on the stack
1447   void frames_do(void f(frame*, const RegisterMap*));
1448 
1449   // Memory operations
1450   void oops_do(OopClosure* f, CLDClosure* cld_f, CodeBlobClosure* cf);
1451 
1452   // Sweeper operations
1453   void nmethods_do(CodeBlobClosure* cf);
1454 
1455   // RedefineClasses Support
1456   void metadata_do(void f(Metadata*));
1457 
1458   // Memory management operations
1459   void gc_epilogue();
1460   void gc_prologue();
1461 
1462   // Misc. operations
1463   char* name() const { return (char*)get_thread_name(); }
1464   void print_on(outputStream* st) const;
1465   void print() const { print_on(tty); }
1466   void print_value();
1467   void print_thread_state_on(outputStream* ) const      PRODUCT_RETURN;
1468   void print_thread_state() const                       PRODUCT_RETURN;
1469   void print_on_error(outputStream* st, char* buf, int buflen) const;
1470   void verify();
1471   const char* get_thread_name() const;
1472 private:
1473   // factor out low-level mechanics for use in both normal and error cases
1474   const char* get_thread_name_string(char* buf = NULL, int buflen = 0) const;
1475 public:
1476   const char* get_threadgroup_name() const;
1477   const char* get_parent_name() const;
1478 
1479   // Accessing frames
1480   frame last_frame() {
1481     _anchor.make_walkable(this);
1482     return pd_last_frame();
1483   }
1484   javaVFrame* last_java_vframe(RegisterMap* reg_map);
1485 
1486   // Returns method at 'depth' java or native frames down the stack
1487   // Used for security checks
1488   Klass* security_get_caller_class(int depth);
1489 
1490   // Print stack trace in external format
1491   void print_stack_on(outputStream* st);
1492   void print_stack() { print_stack_on(tty); }
1493 
1494   // Print stack traces in various internal formats
1495   void trace_stack()                             PRODUCT_RETURN;
1496   void trace_stack_from(vframe* start_vf)        PRODUCT_RETURN;
1497   void trace_frames()                            PRODUCT_RETURN;
1498   void trace_oops()                              PRODUCT_RETURN;
1499 
1500   // Print an annotated view of the stack frames
1501   void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN;
1502   void validate_frame_layout() {
1503     print_frame_layout(0, true);
1504   }
1505 
1506   // Returns the number of stack frames on the stack
1507   int depth() const;
1508 
1509   // Function for testing deoptimization
1510   void deoptimize();
1511   void make_zombies();
1512 
1513   void deoptimized_wrt_marked_nmethods();
1514 
1515   // Profiling operation (see fprofile.cpp)
1516  public:
1517    bool profile_last_Java_frame(frame* fr);
1518 
1519  private:
1520    ThreadProfiler* _thread_profiler;
1521  private:
1522    friend class FlatProfiler;                    // uses both [gs]et_thread_profiler.
1523    friend class FlatProfilerTask;                // uses get_thread_profiler.
1524    friend class ThreadProfilerMark;              // uses get_thread_profiler.
1525    ThreadProfiler* get_thread_profiler()         { return _thread_profiler; }
1526    ThreadProfiler* set_thread_profiler(ThreadProfiler* tp) {
1527      ThreadProfiler* result = _thread_profiler;
1528      _thread_profiler = tp;
1529      return result;
1530    }
1531 
1532  public:
1533   // Returns the running thread as a JavaThread
1534   static inline JavaThread* current();
1535 
1536   // Returns the active Java thread.  Do not use this if you know you are calling
1537   // from a JavaThread, as it's slower than JavaThread::current.  If called from
1538   // the VMThread, it also returns the JavaThread that instigated the VMThread's
1539   // operation.  You may not want that either.
1540   static JavaThread* active();
1541 
1542   inline CompilerThread* as_CompilerThread();
1543 
1544  public:
1545   virtual void run();
1546   void thread_main_inner();
1547 
1548  private:
1549   // PRIVILEGED STACK
1550   PrivilegedElement*  _privileged_stack_top;
1551   GrowableArray<oop>* _array_for_gc;
1552  public:
1553 
1554   // Returns the privileged_stack information.
1555   PrivilegedElement* privileged_stack_top() const       { return _privileged_stack_top; }
1556   void set_privileged_stack_top(PrivilegedElement *e)   { _privileged_stack_top = e; }
1557   void register_array_for_gc(GrowableArray<oop>* array) { _array_for_gc = array; }
1558 
1559  public:
1560   // Thread local information maintained by JVMTI.
1561   void set_jvmti_thread_state(JvmtiThreadState *value)                           { _jvmti_thread_state = value; }
1562   // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1563   // getter is used to get this JavaThread's JvmtiThreadState if it has
1564   // one which means NULL can be returned. JvmtiThreadState::state_for()
1565   // is used to get the specified JavaThread's JvmtiThreadState if it has
1566   // one or it allocates a new JvmtiThreadState for the JavaThread and
1567   // returns it. JvmtiThreadState::state_for() will return NULL only if
1568   // the specified JavaThread is exiting.
1569   JvmtiThreadState *jvmti_thread_state() const                                   { return _jvmti_thread_state; }
1570   static ByteSize jvmti_thread_state_offset()                                    { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1571   void set_jvmti_get_loaded_classes_closure(JvmtiGetLoadedClassesClosure* value) { _jvmti_get_loaded_classes_closure = value; }
1572   JvmtiGetLoadedClassesClosure* get_jvmti_get_loaded_classes_closure() const     { return _jvmti_get_loaded_classes_closure; }
1573 
1574   // JVMTI PopFrame support
1575   // Setting and clearing popframe_condition
1576   // All of these enumerated values are bits. popframe_pending
1577   // indicates that a PopFrame() has been requested and not yet been
1578   // completed. popframe_processing indicates that that PopFrame() is in
1579   // the process of being completed. popframe_force_deopt_reexecution_bit
1580   // indicates that special handling is required when returning to a
1581   // deoptimized caller.
1582   enum PopCondition {
1583     popframe_inactive                      = 0x00,
1584     popframe_pending_bit                   = 0x01,
1585     popframe_processing_bit                = 0x02,
1586     popframe_force_deopt_reexecution_bit   = 0x04
1587   };
1588   PopCondition popframe_condition()                   { return (PopCondition) _popframe_condition; }
1589   void set_popframe_condition(PopCondition c)         { _popframe_condition = c; }
1590   void set_popframe_condition_bit(PopCondition c)     { _popframe_condition |= c; }
1591   void clear_popframe_condition()                     { _popframe_condition = popframe_inactive; }
1592   static ByteSize popframe_condition_offset()         { return byte_offset_of(JavaThread, _popframe_condition); }
1593   bool has_pending_popframe()                         { return (popframe_condition() & popframe_pending_bit) != 0; }
1594   bool popframe_forcing_deopt_reexecution()           { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
1595   void clear_popframe_forcing_deopt_reexecution()     { _popframe_condition &= ~popframe_force_deopt_reexecution_bit; }
1596 #ifdef CC_INTERP
1597   bool pop_frame_pending(void)                        { return ((_popframe_condition & popframe_pending_bit) != 0); }
1598   void clr_pop_frame_pending(void)                    { _popframe_condition = popframe_inactive; }
1599   bool pop_frame_in_process(void)                     { return ((_popframe_condition & popframe_processing_bit) != 0); }
1600   void set_pop_frame_in_process(void)                 { _popframe_condition |= popframe_processing_bit; }
1601   void clr_pop_frame_in_process(void)                 { _popframe_condition &= ~popframe_processing_bit; }
1602 #endif
1603 
1604   int frames_to_pop_failed_realloc() const            { return _frames_to_pop_failed_realloc; }
1605   void set_frames_to_pop_failed_realloc(int nb)       { _frames_to_pop_failed_realloc = nb; }
1606   void dec_frames_to_pop_failed_realloc()             { _frames_to_pop_failed_realloc--; }
1607 
1608  private:
1609   // Saved incoming arguments to popped frame.
1610   // Used only when popped interpreted frame returns to deoptimized frame.
1611   void*    _popframe_preserved_args;
1612   int      _popframe_preserved_args_size;
1613 
1614  public:
1615   void  popframe_preserve_args(ByteSize size_in_bytes, void* start);
1616   void* popframe_preserved_args();
1617   ByteSize popframe_preserved_args_size();
1618   WordSize popframe_preserved_args_size_in_words();
1619   void  popframe_free_preserved_args();
1620 
1621 
1622  private:
1623   JvmtiThreadState *_jvmti_thread_state;
1624   JvmtiGetLoadedClassesClosure* _jvmti_get_loaded_classes_closure;
1625 
1626   // Used by the interpreter in fullspeed mode for frame pop, method
1627   // entry, method exit and single stepping support. This field is
1628   // only set to non-zero by the VM_EnterInterpOnlyMode VM operation.
1629   // It can be set to zero asynchronously (i.e., without a VM operation
1630   // or a lock) so we have to be very careful.
1631   int               _interp_only_mode;
1632 
1633  public:
1634   // used by the interpreter for fullspeed debugging support (see above)
1635   static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
1636   bool is_interp_only_mode()                { return (_interp_only_mode != 0); }
1637   int get_interp_only_mode()                { return _interp_only_mode; }
1638   void increment_interp_only_mode()         { ++_interp_only_mode; }
1639   void decrement_interp_only_mode()         { --_interp_only_mode; }
1640 
1641   // support for cached flag that indicates whether exceptions need to be posted for this thread
1642   // if this is false, we can avoid deoptimizing when events are thrown
1643   // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
1644  private:
1645   int    _should_post_on_exceptions_flag;
1646 
1647  public:
1648   int   should_post_on_exceptions_flag()  { return _should_post_on_exceptions_flag; }
1649   void  set_should_post_on_exceptions_flag(int val)  { _should_post_on_exceptions_flag = val; }
1650 
1651  private:
1652   ThreadStatistics *_thread_stat;
1653 
1654  public:
1655   ThreadStatistics* get_thread_stat() const    { return _thread_stat; }
1656 
1657   // Return a blocker object for which this thread is blocked parking.
1658   oop current_park_blocker();
1659 
1660  private:
1661   static size_t _stack_size_at_create;
1662 
1663  public:
1664   static inline size_t stack_size_at_create(void) {
1665     return _stack_size_at_create;
1666   }
1667   static inline void set_stack_size_at_create(size_t value) {
1668     _stack_size_at_create = value;
1669   }
1670 
1671 #if INCLUDE_ALL_GCS
1672   // SATB marking queue support
1673   ObjPtrQueue& satb_mark_queue() { return _satb_mark_queue; }
1674   static SATBMarkQueueSet& satb_mark_queue_set() {
1675     return _satb_mark_queue_set;
1676   }
1677 
1678   // Dirty card queue support
1679   DirtyCardQueue& dirty_card_queue() { return _dirty_card_queue; }
1680   static DirtyCardQueueSet& dirty_card_queue_set() {
1681     return _dirty_card_queue_set;
1682   }
1683 #endif // INCLUDE_ALL_GCS
1684 
1685   // This method initializes the SATB and dirty card queues before a
1686   // JavaThread is added to the Java thread list. Right now, we don't
1687   // have to do anything to the dirty card queue (it should have been
1688   // activated when the thread was created), but we have to activate
1689   // the SATB queue if the thread is created while a marking cycle is
1690   // in progress. The activation / de-activation of the SATB queues at
1691   // the beginning / end of a marking cycle is done during safepoints
1692   // so we have to make sure this method is called outside one to be
1693   // able to safely read the active field of the SATB queue set. Right
1694   // now, it is called just before the thread is added to the Java
1695   // thread list in the Threads::add() method. That method is holding
1696   // the Threads_lock which ensures we are outside a safepoint. We
1697   // cannot do the obvious and set the active field of the SATB queue
1698   // when the thread is created given that, in some cases, safepoints
1699   // might happen between the JavaThread constructor being called and the
1700   // thread being added to the Java thread list (an example of this is
1701   // when the structure for the DestroyJavaVM thread is created).
1702 #if INCLUDE_ALL_GCS
1703   void initialize_queues();
1704 #else  // INCLUDE_ALL_GCS
1705   void initialize_queues() { }
1706 #endif // INCLUDE_ALL_GCS
1707 
1708   // Machine dependent stuff
1709 #ifdef TARGET_OS_ARCH_linux_x86
1710 # include "thread_linux_x86.hpp"
1711 #endif
1712 #ifdef TARGET_OS_ARCH_linux_aarch64
1713 # include "thread_linux_aarch64.hpp"
1714 #endif
1715 #ifdef TARGET_OS_ARCH_linux_sparc
1716 # include "thread_linux_sparc.hpp"
1717 #endif
1718 #ifdef TARGET_OS_ARCH_linux_zero
1719 # include "thread_linux_zero.hpp"
1720 #endif
1721 #ifdef TARGET_OS_ARCH_solaris_x86
1722 # include "thread_solaris_x86.hpp"
1723 #endif
1724 #ifdef TARGET_OS_ARCH_solaris_sparc
1725 # include "thread_solaris_sparc.hpp"
1726 #endif
1727 #ifdef TARGET_OS_ARCH_windows_x86
1728 # include "thread_windows_x86.hpp"
1729 #endif
1730 #ifdef TARGET_OS_ARCH_linux_arm
1731 # include "thread_linux_arm.hpp"
1732 #endif
1733 #ifdef TARGET_OS_ARCH_linux_ppc
1734 # include "thread_linux_ppc.hpp"
1735 #endif
1736 #ifdef TARGET_OS_ARCH_aix_ppc
1737 # include "thread_aix_ppc.hpp"
1738 #endif
1739 #ifdef TARGET_OS_ARCH_bsd_x86
1740 # include "thread_bsd_x86.hpp"
1741 #endif
1742 #ifdef TARGET_OS_ARCH_bsd_zero
1743 # include "thread_bsd_zero.hpp"
1744 #endif
1745 
1746 
1747  public:
1748   void set_blocked_on_compilation(bool value) {
1749     _blocked_on_compilation = value;
1750   }
1751 
1752   bool blocked_on_compilation() {
1753     return _blocked_on_compilation;
1754   }
1755  protected:
1756   bool         _blocked_on_compilation;
1757 
1758 
1759   // JSR166 per-thread parker
1760 private:
1761   Parker*    _parker;
1762 public:
1763   Parker*     parker() { return _parker; }
1764 
1765   // Biased locking support
1766 private:
1767   GrowableArray<MonitorInfo*>* _cached_monitor_info;
1768 public:
1769   GrowableArray<MonitorInfo*>* cached_monitor_info() { return _cached_monitor_info; }
1770   void set_cached_monitor_info(GrowableArray<MonitorInfo*>* info) { _cached_monitor_info = info; }
1771 
1772   // clearing/querying jni attach status
1773   bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; }
1774   bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
1775   inline void set_done_attaching_via_jni();
1776 private:
1777   // This field is used to determine if a thread has claimed
1778   // a par_id: it is UINT_MAX if the thread has not claimed a par_id;
1779   // otherwise its value is the par_id that has been claimed.
1780   uint _claimed_par_id;
1781 public:
1782   uint get_claimed_par_id() { return _claimed_par_id; }
1783   void set_claimed_par_id(uint id) { _claimed_par_id = id;}
1784 };
1785 
1786 // Inline implementation of JavaThread::current
1787 inline JavaThread* JavaThread::current() {
1788   Thread* thread = Thread::current();
1789   assert(thread->is_Java_thread(), "just checking");
1790   return (JavaThread*)thread;
1791 }
1792 
1793 inline CompilerThread* JavaThread::as_CompilerThread() {
1794   assert(is_Compiler_thread(), "just checking");
1795   return (CompilerThread*)this;
1796 }
1797 
1798 inline bool JavaThread::stack_guard_zone_unused() {
1799   return _stack_guard_state == stack_guard_unused;
1800 }
1801 
1802 inline bool JavaThread::stack_yellow_zone_disabled() {
1803   return _stack_guard_state == stack_guard_yellow_disabled;
1804 }
1805 
1806 inline bool JavaThread::stack_yellow_zone_enabled() {
1807 #ifdef ASSERT
1808   if (os::uses_stack_guard_pages() &&
1809       !(DisablePrimordialThreadGuardPages && os::is_primordial_thread())) {
1810     assert(_stack_guard_state != stack_guard_unused, "guard pages must be in use");
1811   }
1812 #endif
1813     return _stack_guard_state == stack_guard_enabled;
1814 }
1815 
1816 inline size_t JavaThread::stack_available(address cur_sp) {
1817   // This code assumes java stacks grow down
1818   address low_addr; // Limit on the address for deepest stack depth
1819   if ( _stack_guard_state == stack_guard_unused) {
1820     low_addr =  stack_base() - stack_size();
1821   } else {
1822     low_addr = stack_yellow_zone_base();
1823   }
1824   return cur_sp > low_addr ? cur_sp - low_addr : 0;
1825 }
1826 
1827 // A thread used for Compilation.
1828 class CompilerThread : public JavaThread {
1829   friend class VMStructs;
1830  private:
1831   CompilerCounters* _counters;
1832 
1833   ciEnv*            _env;
1834   CompileLog*       _log;
1835   CompileTask*      _task;
1836   CompileQueue*     _queue;
1837   BufferBlob*       _buffer_blob;
1838 
1839   nmethod*          _scanned_nmethod;  // nmethod being scanned by the sweeper
1840   AbstractCompiler* _compiler;
1841 
1842  public:
1843 
1844   static CompilerThread* current();
1845 
1846   CompilerThread(CompileQueue* queue, CompilerCounters* counters);
1847 
1848   bool is_Compiler_thread() const                { return true; }
1849   // Hide this compiler thread from external view.
1850   bool is_hidden_from_external_view() const      { return true; }
1851 
1852   void set_compiler(AbstractCompiler* c)         { _compiler = c; }
1853   AbstractCompiler* compiler() const             { return _compiler; }
1854 
1855   CompileQueue* queue()        const             { return _queue; }
1856   CompilerCounters* counters() const             { return _counters; }
1857 
1858   // Get/set the thread's compilation environment.
1859   ciEnv*        env()                            { return _env; }
1860   void          set_env(ciEnv* env)              { _env = env; }
1861 
1862   BufferBlob*   get_buffer_blob() const          { return _buffer_blob; }
1863   void          set_buffer_blob(BufferBlob* b)   { _buffer_blob = b; };
1864 
1865   // Get/set the thread's logging information
1866   CompileLog*   log()                            { return _log; }
1867   void          init_log(CompileLog* log) {
1868     // Set once, for good.
1869     assert(_log == NULL, "set only once");
1870     _log = log;
1871   }
1872 
1873   // GC support
1874   // Apply "f->do_oop" to all root oops in "this".
1875   // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames
1876   void oops_do(OopClosure* f, CLDClosure* cld_f, CodeBlobClosure* cf);
1877 
1878 #ifndef PRODUCT
1879 private:
1880   IdealGraphPrinter *_ideal_graph_printer;
1881 public:
1882   IdealGraphPrinter *ideal_graph_printer()                       { return _ideal_graph_printer; }
1883   void set_ideal_graph_printer(IdealGraphPrinter *n)             { _ideal_graph_printer = n; }
1884 #endif
1885 
1886   // Get/set the thread's current task
1887   CompileTask*  task()                           { return _task; }
1888   void          set_task(CompileTask* task)      { _task = task; }
1889 
1890   // Track the nmethod currently being scanned by the sweeper
1891   void          set_scanned_nmethod(nmethod* nm) {
1892     assert(_scanned_nmethod == NULL || nm == NULL, "should reset to NULL before writing a new value");
1893     _scanned_nmethod = nm;
1894   }
1895 };
1896 
1897 inline CompilerThread* CompilerThread::current() {
1898   return JavaThread::current()->as_CompilerThread();
1899 }
1900 
1901 
1902 // The active thread queue. It also keeps track of the current used
1903 // thread priorities.
1904 class Threads: AllStatic {
1905   friend class VMStructs;
1906  private:
1907   static JavaThread* _thread_list;
1908   static int         _number_of_threads;
1909   static int         _number_of_non_daemon_threads;
1910   static int         _return_code;
1911 #ifdef ASSERT
1912   static bool        _vm_complete;
1913 #endif
1914 
1915  public:
1916   // Thread management
1917   // force_daemon is a concession to JNI, where we may need to add a
1918   // thread to the thread list before allocating its thread object
1919   static void add(JavaThread* p, bool force_daemon = false);
1920   static void remove(JavaThread* p);
1921   static bool includes(JavaThread* p);
1922   static JavaThread* first()                     { return _thread_list; }
1923   static void threads_do(ThreadClosure* tc);
1924 
1925   // Initializes the vm and creates the vm thread
1926   static jint create_vm(JavaVMInitArgs* args, bool* canTryAgain);
1927   static void convert_vm_init_libraries_to_agents();
1928   static void create_vm_init_libraries();
1929   static void create_vm_init_agents();
1930   static void shutdown_vm_agents();
1931   static bool destroy_vm();
1932   // Supported VM versions via JNI
1933   // Includes JNI_VERSION_1_1
1934   static jboolean is_supported_jni_version_including_1_1(jint version);
1935   // Does not include JNI_VERSION_1_1
1936   static jboolean is_supported_jni_version(jint version);
1937 
1938   // Garbage collection
1939   static void follow_other_roots(void f(oop*));
1940 
1941   // Apply "f->do_oop" to all root oops in all threads.
1942   // This version may only be called by sequential code.
1943   static void oops_do(OopClosure* f, CLDClosure* cld_f, CodeBlobClosure* cf);
1944   // This version may be called by sequential or parallel code.
1945   static void possibly_parallel_oops_do(OopClosure* f, CLDClosure* cld_f, CodeBlobClosure* cf);
1946   // This creates a list of GCTasks, one per thread.
1947   static void create_thread_roots_tasks(GCTaskQueue* q);
1948   // This creates a list of GCTasks, one per thread, for marking objects.
1949   static void create_thread_roots_marking_tasks(GCTaskQueue* q);
1950 
1951   // Apply "f->do_oop" to roots in all threads that
1952   // are part of compiled frames
1953   static void compiled_frame_oops_do(OopClosure* f, CodeBlobClosure* cf);
1954 
1955   static void convert_hcode_pointers();
1956   static void restore_hcode_pointers();
1957 
1958   // Sweeper
1959   static void nmethods_do(CodeBlobClosure* cf);
1960 
1961   // RedefineClasses support
1962   static void metadata_do(void f(Metadata*));
1963 
1964   static void gc_epilogue();
1965   static void gc_prologue();
1966 #ifdef ASSERT
1967   static bool is_vm_complete() { return _vm_complete; }
1968 #endif
1969 
1970   // Verification
1971   static void verify();
1972   static void print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks);
1973   static void print(bool print_stacks, bool internal_format) {
1974     // this function is only used by debug.cpp
1975     print_on(tty, print_stacks, internal_format, false /* no concurrent lock printed */);
1976   }
1977   static void print_on_error(outputStream* st, Thread* current, char* buf, int buflen);
1978 
1979   // Get Java threads that are waiting to enter a monitor. If doLock
1980   // is true, then Threads_lock is grabbed as needed. Otherwise, the
1981   // VM needs to be at a safepoint.
1982   static GrowableArray<JavaThread*>* get_pending_threads(int count,
1983     address monitor, bool doLock);
1984 
1985   // Get owning Java thread from the monitor's owner field. If doLock
1986   // is true, then Threads_lock is grabbed as needed. Otherwise, the
1987   // VM needs to be at a safepoint.
1988   static JavaThread *owning_thread_from_monitor_owner(address owner,
1989     bool doLock);
1990 
1991   // Number of threads on the active threads list
1992   static int number_of_threads()                 { return _number_of_threads; }
1993   // Number of non-daemon threads on the active threads list
1994   static int number_of_non_daemon_threads()      { return _number_of_non_daemon_threads; }
1995 
1996   // Deoptimizes all frames tied to marked nmethods
1997   static void deoptimized_wrt_marked_nmethods();
1998 
1999   static JavaThread* find_java_thread_from_java_tid(jlong java_tid);
2000 
2001 };
2002 
2003 
2004 // Thread iterator
2005 class ThreadClosure: public StackObj {
2006  public:
2007   virtual void do_thread(Thread* thread) = 0;
2008 };
2009 
2010 class SignalHandlerMark: public StackObj {
2011 private:
2012   Thread* _thread;
2013 public:
2014   SignalHandlerMark(Thread* t) {
2015     _thread = t;
2016     if (_thread) _thread->enter_signal_handler();
2017   }
2018   ~SignalHandlerMark() {
2019     if (_thread) _thread->leave_signal_handler();
2020     _thread = NULL;
2021   }
2022 };
2023 
2024 
2025 #endif // SHARE_VM_RUNTIME_THREAD_HPP