1 /*
   2  * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_RUNTIME_THREAD_HPP
  26 #define SHARE_VM_RUNTIME_THREAD_HPP
  27 
  28 #include "gc/shared/threadLocalAllocBuffer.hpp"
  29 #include "memory/allocation.hpp"
  30 #include "oops/oop.hpp"
  31 #include "prims/jni.h"
  32 #include "prims/jvmtiExport.hpp"
  33 #include "runtime/frame.hpp"
  34 #include "runtime/javaFrameAnchor.hpp"
  35 #include "runtime/jniHandles.hpp"
  36 #include "runtime/mutexLocker.hpp"
  37 #include "runtime/os.hpp"
  38 #include "runtime/osThread.hpp"
  39 #include "runtime/park.hpp"
  40 #include "runtime/safepoint.hpp"
  41 #include "runtime/stubRoutines.hpp"
  42 #include "runtime/threadLocalStorage.hpp"
  43 #include "runtime/thread_ext.hpp"
  44 #include "runtime/unhandledOops.hpp"
  45 #include "trace/traceBackend.hpp"
  46 #include "trace/traceMacros.hpp"
  47 #include "utilities/align.hpp"
  48 #include "utilities/exceptions.hpp"
  49 #include "utilities/macros.hpp"
  50 #if INCLUDE_ALL_GCS
  51 #include "gc/g1/dirtyCardQueue.hpp"
  52 #include "gc/g1/satbMarkQueue.hpp"
  53 #endif // INCLUDE_ALL_GCS
  54 #ifdef ZERO
  55 # include "stack_zero.hpp"
  56 #endif
  57 
  58 class ThreadSafepointState;
  59 class ThreadProfiler;
  60 
  61 class JvmtiThreadState;
  62 class JvmtiGetLoadedClassesClosure;
  63 class ThreadStatistics;
  64 class ConcurrentLocksDump;
  65 class ParkEvent;
  66 class Parker;
  67 
  68 class ciEnv;
  69 class CompileThread;
  70 class CompileLog;
  71 class CompileTask;
  72 class CompileQueue;
  73 class CompilerCounters;
  74 class vframeArray;
  75 
  76 class DeoptResourceMark;
  77 class jvmtiDeferredLocalVariableSet;
  78 
  79 class GCTaskQueue;
  80 class ThreadClosure;
  81 class IdealGraphPrinter;
  82 
  83 class Metadata;
  84 template <class T, MEMFLAGS F> class ChunkedList;
  85 typedef ChunkedList<Metadata*, mtInternal> MetadataOnStackBuffer;
  86 
  87 DEBUG_ONLY(class ResourceMark;)
  88 
  89 class WorkerThread;
  90 
  91 // Class hierarchy
  92 // - Thread
  93 //   - NamedThread
  94 //     - VMThread
  95 //     - ConcurrentGCThread
  96 //     - WorkerThread
  97 //       - GangWorker
  98 //       - GCTaskThread
  99 //   - JavaThread
 100 //     - various subclasses eg CompilerThread, ServiceThread
 101 //   - WatcherThread
 102 
 103 class Thread: public ThreadShadow {
 104   friend class VMStructs;
 105   friend class JVMCIVMStructs;
 106  private:
 107 
 108 #ifndef USE_LIBRARY_BASED_TLS_ONLY
 109   // Current thread is maintained as a thread-local variable
 110   static THREAD_LOCAL_DECL Thread* _thr_current;
 111 #endif
 112 
 113   // Exception handling
 114   // (Note: _pending_exception and friends are in ThreadShadow)
 115   //oop       _pending_exception;                // pending exception for current thread
 116   // const char* _exception_file;                   // file information for exception (debugging only)
 117   // int         _exception_line;                   // line information for exception (debugging only)
 118  protected:
 119   // Support for forcing alignment of thread objects for biased locking
 120   void*       _real_malloc_address;
 121  public:
 122   void* operator new(size_t size) throw() { return allocate(size, true); }
 123   void* operator new(size_t size, const std::nothrow_t& nothrow_constant) throw() {
 124     return allocate(size, false); }
 125   void  operator delete(void* p);
 126 
 127  protected:
 128   static void* allocate(size_t size, bool throw_excpt, MEMFLAGS flags = mtThread);
 129  private:
 130 
 131   // ***************************************************************
 132   // Suspend and resume support
 133   // ***************************************************************
 134   //
 135   // VM suspend/resume no longer exists - it was once used for various
 136   // things including safepoints but was deprecated and finally removed
 137   // in Java 7. Because VM suspension was considered "internal" Java-level
 138   // suspension was considered "external", and this legacy naming scheme
 139   // remains.
 140   //
 141   // External suspend/resume requests come from JVM_SuspendThread,
 142   // JVM_ResumeThread, JVMTI SuspendThread, and finally JVMTI
 143   // ResumeThread. External
 144   // suspend requests cause _external_suspend to be set and external
 145   // resume requests cause _external_suspend to be cleared.
 146   // External suspend requests do not nest on top of other external
 147   // suspend requests. The higher level APIs reject suspend requests
 148   // for already suspended threads.
 149   //
 150   // The external_suspend
 151   // flag is checked by has_special_runtime_exit_condition() and java thread
 152   // will self-suspend when handle_special_runtime_exit_condition() is
 153   // called. Most uses of the _thread_blocked state in JavaThreads are
 154   // considered the same as being externally suspended; if the blocking
 155   // condition lifts, the JavaThread will self-suspend. Other places
 156   // where VM checks for external_suspend include:
 157   //   + mutex granting (do not enter monitors when thread is suspended)
 158   //   + state transitions from _thread_in_native
 159   //
 160   // In general, java_suspend() does not wait for an external suspend
 161   // request to complete. When it returns, the only guarantee is that
 162   // the _external_suspend field is true.
 163   //
 164   // wait_for_ext_suspend_completion() is used to wait for an external
 165   // suspend request to complete. External suspend requests are usually
 166   // followed by some other interface call that requires the thread to
 167   // be quiescent, e.g., GetCallTrace(). By moving the "wait time" into
 168   // the interface that requires quiescence, we give the JavaThread a
 169   // chance to self-suspend before we need it to be quiescent. This
 170   // improves overall suspend/query performance.
 171   //
 172   // _suspend_flags controls the behavior of java_ suspend/resume.
 173   // It must be set under the protection of SR_lock. Read from the flag is
 174   // OK without SR_lock as long as the value is only used as a hint.
 175   // (e.g., check _external_suspend first without lock and then recheck
 176   // inside SR_lock and finish the suspension)
 177   //
 178   // _suspend_flags is also overloaded for other "special conditions" so
 179   // that a single check indicates whether any special action is needed
 180   // eg. for async exceptions.
 181   // -------------------------------------------------------------------
 182   // Notes:
 183   // 1. The suspend/resume logic no longer uses ThreadState in OSThread
 184   // but we still update its value to keep other part of the system (mainly
 185   // JVMTI) happy. ThreadState is legacy code (see notes in
 186   // osThread.hpp).
 187   //
 188   // 2. It would be more natural if set_external_suspend() is private and
 189   // part of java_suspend(), but that probably would affect the suspend/query
 190   // performance. Need more investigation on this.
 191 
 192   // suspend/resume lock: used for self-suspend
 193   Monitor* _SR_lock;
 194 
 195  protected:
 196   enum SuspendFlags {
 197     // NOTE: avoid using the sign-bit as cc generates different test code
 198     //       when the sign-bit is used, and sometimes incorrectly - see CR 6398077
 199 
 200     _external_suspend       = 0x20000000U, // thread is asked to self suspend
 201     _ext_suspended          = 0x40000000U, // thread has self-suspended
 202     _deopt_suspend          = 0x10000000U, // thread needs to self suspend for deopt
 203 
 204     _has_async_exception    = 0x00000001U, // there is a pending async exception
 205     _critical_native_unlock = 0x00000002U, // Must call back to unlock JNI critical lock
 206 
 207     _trace_flag             = 0x00000004U  // call tracing backend
 208   };
 209 
 210   // various suspension related flags - atomically updated
 211   // overloaded for async exception checking in check_special_condition_for_native_trans.
 212   volatile uint32_t _suspend_flags;
 213 
 214  private:
 215   int _num_nested_signal;
 216 
 217   DEBUG_ONLY(bool _suspendible_thread;)
 218 
 219  public:
 220   void enter_signal_handler() { _num_nested_signal++; }
 221   void leave_signal_handler() { _num_nested_signal--; }
 222   bool is_inside_signal_handler() const { return _num_nested_signal > 0; }
 223 
 224 #ifdef ASSERT
 225   void set_suspendible_thread() {
 226     _suspendible_thread = true;
 227   }
 228 
 229   void clear_suspendible_thread() {
 230     _suspendible_thread = false;
 231   }
 232 
 233   bool is_suspendible_thread() { return _suspendible_thread; }
 234 #endif
 235 
 236  private:
 237   // Active_handles points to a block of handles
 238   JNIHandleBlock* _active_handles;
 239 
 240   // One-element thread local free list
 241   JNIHandleBlock* _free_handle_block;
 242 
 243   // Point to the last handle mark
 244   HandleMark* _last_handle_mark;
 245 
 246   // The parity of the last strong_roots iteration in which this thread was
 247   // claimed as a task.
 248   jint _oops_do_parity;
 249 
 250  public:
 251   void set_last_handle_mark(HandleMark* mark)   { _last_handle_mark = mark; }
 252   HandleMark* last_handle_mark() const          { return _last_handle_mark; }
 253  private:
 254 
 255   // debug support for checking if code does allow safepoints or not
 256   // GC points in the VM can happen because of allocation, invoking a VM operation, or blocking on
 257   // mutex, or blocking on an object synchronizer (Java locking).
 258   // If !allow_safepoint(), then an assertion failure will happen in any of the above cases
 259   // If !allow_allocation(), then an assertion failure will happen during allocation
 260   // (Hence, !allow_safepoint() => !allow_allocation()).
 261   //
 262   // The two classes NoSafepointVerifier and No_Allocation_Verifier are used to set these counters.
 263   //
 264   NOT_PRODUCT(int _allow_safepoint_count;)      // If 0, thread allow a safepoint to happen
 265   debug_only(int _allow_allocation_count;)     // If 0, the thread is allowed to allocate oops.
 266 
 267   // Used by SkipGCALot class.
 268   NOT_PRODUCT(bool _skip_gcalot;)               // Should we elide gc-a-lot?
 269 
 270   friend class NoAllocVerifier;
 271   friend class NoSafepointVerifier;
 272   friend class PauseNoSafepointVerifier;
 273   friend class GCLocker;
 274 
 275   ThreadLocalAllocBuffer _tlab;                 // Thread-local eden
 276   jlong _allocated_bytes;                       // Cumulative number of bytes allocated on
 277                                                 // the Java heap
 278 
 279   mutable TRACE_DATA _trace_data;               // Thread-local data for tracing
 280 
 281   ThreadExt _ext;
 282 
 283   int   _vm_operation_started_count;            // VM_Operation support
 284   int   _vm_operation_completed_count;          // VM_Operation support
 285 
 286   ObjectMonitor* _current_pending_monitor;      // ObjectMonitor this thread
 287                                                 // is waiting to lock
 288   bool _current_pending_monitor_is_from_java;   // locking is from Java code
 289 
 290   // ObjectMonitor on which this thread called Object.wait()
 291   ObjectMonitor* _current_waiting_monitor;
 292 
 293   // Private thread-local objectmonitor list - a simple cache organized as a SLL.
 294  public:
 295   ObjectMonitor* omFreeList;
 296   int omFreeCount;                              // length of omFreeList
 297   int omFreeProvision;                          // reload chunk size
 298   ObjectMonitor* omInUseList;                   // SLL to track monitors in circulation
 299   int omInUseCount;                             // length of omInUseList
 300 
 301 #ifdef ASSERT
 302  private:
 303   bool _visited_for_critical_count;
 304 
 305  public:
 306   void set_visited_for_critical_count(bool z) { _visited_for_critical_count = z; }
 307   bool was_visited_for_critical_count() const   { return _visited_for_critical_count; }
 308 #endif
 309 
 310  public:
 311   enum {
 312     is_definitely_current_thread = true
 313   };
 314 
 315   // Constructor
 316   Thread();
 317   virtual ~Thread();
 318 
 319   // Manage Thread::current()
 320   void initialize_thread_current();
 321   void clear_thread_current(); // TLS cleanup needed before threads terminate
 322 
 323   public:
 324   // thread entry point
 325   virtual void run();
 326 
 327   // Testers
 328   virtual bool is_VM_thread()       const            { return false; }
 329   virtual bool is_Java_thread()     const            { return false; }
 330   virtual bool is_Compiler_thread() const            { return false; }
 331   virtual bool is_Code_cache_sweeper_thread() const  { return false; }
 332   virtual bool is_hidden_from_external_view() const  { return false; }
 333   virtual bool is_jvmti_agent_thread() const         { return false; }
 334   // True iff the thread can perform GC operations at a safepoint.
 335   // Generally will be true only of VM thread and parallel GC WorkGang
 336   // threads.
 337   virtual bool is_GC_task_thread() const             { return false; }
 338   virtual bool is_Watcher_thread() const             { return false; }
 339   virtual bool is_ConcurrentGC_thread() const        { return false; }
 340   virtual bool is_Named_thread() const               { return false; }
 341   virtual bool is_Worker_thread() const              { return false; }
 342 
 343   // Can this thread make Java upcalls
 344   virtual bool can_call_java() const                 { return false; }
 345 
 346   // Casts
 347   virtual WorkerThread* as_Worker_thread() const     { return NULL; }
 348 
 349   virtual char* name() const { return (char*)"Unknown thread"; }
 350 
 351   // Returns the current thread (ASSERTS if NULL)
 352   static inline Thread* current();
 353   // Returns the current thread, or NULL if not attached
 354   static inline Thread* current_or_null();
 355   // Returns the current thread, or NULL if not attached, and is
 356   // safe for use from signal-handlers
 357   static inline Thread* current_or_null_safe();
 358 
 359   // Common thread operations
 360   static void set_priority(Thread* thread, ThreadPriority priority);
 361   static ThreadPriority get_priority(const Thread* const thread);
 362   static void start(Thread* thread);
 363   static void interrupt(Thread* thr);
 364   static bool is_interrupted(Thread* thr, bool clear_interrupted);
 365 
 366   void set_native_thread_name(const char *name) {
 367     assert(Thread::current() == this, "set_native_thread_name can only be called on the current thread");
 368     os::set_native_thread_name(name);
 369   }
 370 
 371   ObjectMonitor** omInUseList_addr()             { return (ObjectMonitor **)&omInUseList; }
 372   Monitor* SR_lock() const                       { return _SR_lock; }
 373 
 374   bool has_async_exception() const { return (_suspend_flags & _has_async_exception) != 0; }
 375 
 376   inline void set_suspend_flag(SuspendFlags f);
 377   inline void clear_suspend_flag(SuspendFlags f);
 378 
 379   inline void set_has_async_exception();
 380   inline void clear_has_async_exception();
 381 
 382   bool do_critical_native_unlock() const { return (_suspend_flags & _critical_native_unlock) != 0; }
 383 
 384   inline void set_critical_native_unlock();
 385   inline void clear_critical_native_unlock();
 386 
 387   inline void set_trace_flag();
 388   inline void clear_trace_flag();
 389 
 390   // Support for Unhandled Oop detection
 391   // Add the field for both, fastdebug and debug, builds to keep
 392   // Thread's fields layout the same.
 393   // Note: CHECK_UNHANDLED_OOPS is defined only for fastdebug build.
 394 #ifdef CHECK_UNHANDLED_OOPS
 395  private:
 396   UnhandledOops* _unhandled_oops;
 397 #elif defined(ASSERT)
 398  private:
 399   void* _unhandled_oops;
 400 #endif
 401 #ifdef CHECK_UNHANDLED_OOPS
 402  public:
 403   UnhandledOops* unhandled_oops() { return _unhandled_oops; }
 404   // Mark oop safe for gc.  It may be stack allocated but won't move.
 405   void allow_unhandled_oop(oop *op) {
 406     if (CheckUnhandledOops) unhandled_oops()->allow_unhandled_oop(op);
 407   }
 408   // Clear oops at safepoint so crashes point to unhandled oop violator
 409   void clear_unhandled_oops() {
 410     if (CheckUnhandledOops) unhandled_oops()->clear_unhandled_oops();
 411   }
 412 #endif // CHECK_UNHANDLED_OOPS
 413 
 414  public:
 415 #ifndef PRODUCT
 416   bool skip_gcalot()           { return _skip_gcalot; }
 417   void set_skip_gcalot(bool v) { _skip_gcalot = v;    }
 418 #endif
 419 
 420   // Installs a pending exception to be inserted later
 421   static void send_async_exception(oop thread_oop, oop java_throwable);
 422 
 423   // Resource area
 424   ResourceArea* resource_area() const            { return _resource_area; }
 425   void set_resource_area(ResourceArea* area)     { _resource_area = area; }
 426 
 427   OSThread* osthread() const                     { return _osthread;   }
 428   void set_osthread(OSThread* thread)            { _osthread = thread; }
 429 
 430   // JNI handle support
 431   JNIHandleBlock* active_handles() const         { return _active_handles; }
 432   void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
 433   JNIHandleBlock* free_handle_block() const      { return _free_handle_block; }
 434   void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
 435 
 436   // Internal handle support
 437   HandleArea* handle_area() const                { return _handle_area; }
 438   void set_handle_area(HandleArea* area)         { _handle_area = area; }
 439 
 440   GrowableArray<Metadata*>* metadata_handles() const          { return _metadata_handles; }
 441   void set_metadata_handles(GrowableArray<Metadata*>* handles){ _metadata_handles = handles; }
 442 
 443   // Thread-Local Allocation Buffer (TLAB) support
 444   ThreadLocalAllocBuffer& tlab()                 { return _tlab; }
 445   void initialize_tlab() {
 446     if (UseTLAB) {
 447       tlab().initialize();
 448     }
 449   }
 450 
 451   jlong allocated_bytes()               { return _allocated_bytes; }
 452   void set_allocated_bytes(jlong value) { _allocated_bytes = value; }
 453   void incr_allocated_bytes(jlong size) { _allocated_bytes += size; }
 454   inline jlong cooked_allocated_bytes();
 455 
 456   TRACE_DEFINE_THREAD_TRACE_DATA_OFFSET;
 457   TRACE_DATA* trace_data() const        { return &_trace_data; }
 458   bool is_trace_suspend()               { return (_suspend_flags & _trace_flag) != 0; }
 459 
 460   const ThreadExt& ext() const          { return _ext; }
 461   ThreadExt& ext()                      { return _ext; }
 462 
 463   // VM operation support
 464   int vm_operation_ticket()                      { return ++_vm_operation_started_count; }
 465   int vm_operation_completed_count()             { return _vm_operation_completed_count; }
 466   void increment_vm_operation_completed_count()  { _vm_operation_completed_count++; }
 467 
 468   // For tracking the heavyweight monitor the thread is pending on.
 469   ObjectMonitor* current_pending_monitor() {
 470     return _current_pending_monitor;
 471   }
 472   void set_current_pending_monitor(ObjectMonitor* monitor) {
 473     _current_pending_monitor = monitor;
 474   }
 475   void set_current_pending_monitor_is_from_java(bool from_java) {
 476     _current_pending_monitor_is_from_java = from_java;
 477   }
 478   bool current_pending_monitor_is_from_java() {
 479     return _current_pending_monitor_is_from_java;
 480   }
 481 
 482   // For tracking the ObjectMonitor on which this thread called Object.wait()
 483   ObjectMonitor* current_waiting_monitor() {
 484     return _current_waiting_monitor;
 485   }
 486   void set_current_waiting_monitor(ObjectMonitor* monitor) {
 487     _current_waiting_monitor = monitor;
 488   }
 489 
 490   // GC support
 491   // Apply "f->do_oop" to all root oops in "this".
 492   //   Used by JavaThread::oops_do.
 493   // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames
 494   virtual void oops_do(OopClosure* f, CodeBlobClosure* cf);
 495 
 496   // Handles the parallel case for the method below.
 497  private:
 498   bool claim_oops_do_par_case(int collection_parity);
 499  public:
 500   // Requires that "collection_parity" is that of the current roots
 501   // iteration.  If "is_par" is false, sets the parity of "this" to
 502   // "collection_parity", and returns "true".  If "is_par" is true,
 503   // uses an atomic instruction to set the current threads parity to
 504   // "collection_parity", if it is not already.  Returns "true" iff the
 505   // calling thread does the update, this indicates that the calling thread
 506   // has claimed the thread's stack as a root groop in the current
 507   // collection.
 508   bool claim_oops_do(bool is_par, int collection_parity) {
 509     if (!is_par) {
 510       _oops_do_parity = collection_parity;
 511       return true;
 512     } else {
 513       return claim_oops_do_par_case(collection_parity);
 514     }
 515   }
 516 
 517   // jvmtiRedefineClasses support
 518   void metadata_handles_do(void f(Metadata*));
 519 
 520   // Used by fast lock support
 521   virtual bool is_lock_owned(address adr) const;
 522 
 523   // Check if address is in the stack of the thread (not just for locks).
 524   // Warning: the method can only be used on the running thread
 525   bool is_in_stack(address adr) const;
 526   // Check if address is in the usable part of the stack (excludes protected
 527   // guard pages)
 528   bool is_in_usable_stack(address adr) const;
 529 
 530   // Sets this thread as starting thread. Returns failure if thread
 531   // creation fails due to lack of memory, too many threads etc.
 532   bool set_as_starting_thread();
 533 
 534 protected:
 535   // OS data associated with the thread
 536   OSThread* _osthread;  // Platform-specific thread information
 537 
 538   // Thread local resource area for temporary allocation within the VM
 539   ResourceArea* _resource_area;
 540 
 541   DEBUG_ONLY(ResourceMark* _current_resource_mark;)
 542 
 543   // Thread local handle area for allocation of handles within the VM
 544   HandleArea* _handle_area;
 545   GrowableArray<Metadata*>* _metadata_handles;
 546 
 547   // Support for stack overflow handling, get_thread, etc.
 548   address          _stack_base;
 549   size_t           _stack_size;
 550   uintptr_t        _self_raw_id;      // used by get_thread (mutable)
 551   int              _lgrp_id;
 552 
 553  public:
 554   // Stack overflow support
 555   address stack_base() const           { assert(_stack_base != NULL,"Sanity check"); return _stack_base; }
 556   void    set_stack_base(address base) { _stack_base = base; }
 557   size_t  stack_size() const           { return _stack_size; }
 558   void    set_stack_size(size_t size)  { _stack_size = size; }
 559   address stack_end()  const           { return stack_base() - stack_size(); }
 560   void    record_stack_base_and_size();
 561 
 562   bool    on_local_stack(address adr) const {
 563     // QQQ this has knowledge of direction, ought to be a stack method
 564     return (_stack_base >= adr && adr >= stack_end());
 565   }
 566 
 567   uintptr_t self_raw_id()                    { return _self_raw_id; }
 568   void      set_self_raw_id(uintptr_t value) { _self_raw_id = value; }
 569 
 570   int     lgrp_id() const        { return _lgrp_id; }
 571   void    set_lgrp_id(int value) { _lgrp_id = value; }
 572 
 573   // Printing
 574   virtual void print_on(outputStream* st) const;
 575   void print() const { print_on(tty); }
 576   virtual void print_on_error(outputStream* st, char* buf, int buflen) const;
 577 
 578   // Debug-only code
 579 #ifdef ASSERT
 580  private:
 581   // Deadlock detection support for Mutex locks. List of locks own by thread.
 582   Monitor* _owned_locks;
 583   // Mutex::set_owner_implementation is the only place where _owned_locks is modified,
 584   // thus the friendship
 585   friend class Mutex;
 586   friend class Monitor;
 587 
 588  public:
 589   void print_owned_locks_on(outputStream* st) const;
 590   void print_owned_locks() const                 { print_owned_locks_on(tty);    }
 591   Monitor* owned_locks() const                   { return _owned_locks;          }
 592   bool owns_locks() const                        { return owned_locks() != NULL; }
 593   bool owns_locks_but_compiled_lock() const;
 594   int oops_do_parity() const                     { return _oops_do_parity; }
 595 
 596   // Deadlock detection
 597   bool allow_allocation()                        { return _allow_allocation_count == 0; }
 598   ResourceMark* current_resource_mark()          { return _current_resource_mark; }
 599   void set_current_resource_mark(ResourceMark* rm) { _current_resource_mark = rm; }
 600 #endif
 601 
 602   void check_for_valid_safepoint_state(bool potential_vm_operation) PRODUCT_RETURN;
 603 
 604  private:
 605   volatile int _jvmti_env_iteration_count;
 606 
 607  public:
 608   void entering_jvmti_env_iteration()            { ++_jvmti_env_iteration_count; }
 609   void leaving_jvmti_env_iteration()             { --_jvmti_env_iteration_count; }
 610   bool is_inside_jvmti_env_iteration()           { return _jvmti_env_iteration_count > 0; }
 611 
 612   // Code generation
 613   static ByteSize exception_file_offset()        { return byte_offset_of(Thread, _exception_file); }
 614   static ByteSize exception_line_offset()        { return byte_offset_of(Thread, _exception_line); }
 615   static ByteSize active_handles_offset()        { return byte_offset_of(Thread, _active_handles); }
 616 
 617   static ByteSize stack_base_offset()            { return byte_offset_of(Thread, _stack_base); }
 618   static ByteSize stack_size_offset()            { return byte_offset_of(Thread, _stack_size); }
 619 
 620 #define TLAB_FIELD_OFFSET(name) \
 621   static ByteSize tlab_##name##_offset()         { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::name##_offset(); }
 622 
 623   TLAB_FIELD_OFFSET(start)
 624   TLAB_FIELD_OFFSET(end)
 625   TLAB_FIELD_OFFSET(top)
 626   TLAB_FIELD_OFFSET(pf_top)
 627   TLAB_FIELD_OFFSET(size)                   // desired_size
 628   TLAB_FIELD_OFFSET(refill_waste_limit)
 629   TLAB_FIELD_OFFSET(number_of_refills)
 630   TLAB_FIELD_OFFSET(fast_refill_waste)
 631   TLAB_FIELD_OFFSET(slow_allocations)
 632 
 633 #undef TLAB_FIELD_OFFSET
 634 
 635   static ByteSize allocated_bytes_offset()       { return byte_offset_of(Thread, _allocated_bytes); }
 636 
 637  public:
 638   volatile intptr_t _Stalled;
 639   volatile int _TypeTag;
 640   ParkEvent * _ParkEvent;                     // for synchronized()
 641   ParkEvent * _SleepEvent;                    // for Thread.sleep
 642   ParkEvent * _MutexEvent;                    // for native internal Mutex/Monitor
 643   ParkEvent * _MuxEvent;                      // for low-level muxAcquire-muxRelease
 644   int NativeSyncRecursion;                    // diagnostic
 645 
 646   volatile int _OnTrap;                       // Resume-at IP delta
 647   jint _hashStateW;                           // Marsaglia Shift-XOR thread-local RNG
 648   jint _hashStateX;                           // thread-specific hashCode generator state
 649   jint _hashStateY;
 650   jint _hashStateZ;
 651   void * _schedctl;
 652 
 653 
 654   volatile jint rng[4];                      // RNG for spin loop
 655 
 656   // Low-level leaf-lock primitives used to implement synchronization
 657   // and native monitor-mutex infrastructure.
 658   // Not for general synchronization use.
 659   static void SpinAcquire(volatile int * Lock, const char * Name);
 660   static void SpinRelease(volatile int * Lock);
 661   static void muxAcquire(volatile intptr_t * Lock, const char * Name);
 662   static void muxAcquireW(volatile intptr_t * Lock, ParkEvent * ev);
 663   static void muxRelease(volatile intptr_t * Lock);
 664 };
 665 
 666 // Inline implementation of Thread::current()
 667 inline Thread* Thread::current() {
 668   Thread* current = current_or_null();
 669   assert(current != NULL, "Thread::current() called on detached thread");
 670   return current;
 671 }
 672 
 673 inline Thread* Thread::current_or_null() {
 674 #ifndef USE_LIBRARY_BASED_TLS_ONLY
 675   return _thr_current;
 676 #else
 677   return ThreadLocalStorage::thread();
 678 #endif
 679 }
 680 
 681 inline Thread* Thread::current_or_null_safe() {
 682   return ThreadLocalStorage::thread();
 683 }
 684 
 685 // Name support for threads.  non-JavaThread subclasses with multiple
 686 // uniquely named instances should derive from this.
 687 class NamedThread: public Thread {
 688   friend class VMStructs;
 689   enum {
 690     max_name_len = 64
 691   };
 692  private:
 693   char* _name;
 694   // log JavaThread being processed by oops_do
 695   JavaThread* _processed_thread;
 696   uint _gc_id; // The current GC id when a thread takes part in GC
 697 
 698  public:
 699   NamedThread();
 700   ~NamedThread();
 701   // May only be called once per thread.
 702   void set_name(const char* format, ...)  ATTRIBUTE_PRINTF(2, 3);
 703   void initialize_named_thread();
 704   virtual bool is_Named_thread() const { return true; }
 705   virtual char* name() const { return _name == NULL ? (char*)"Unknown Thread" : _name; }
 706   JavaThread *processed_thread() { return _processed_thread; }
 707   void set_processed_thread(JavaThread *thread) { _processed_thread = thread; }
 708   virtual void print_on(outputStream* st) const;
 709 
 710   void set_gc_id(uint gc_id) { _gc_id = gc_id; }
 711   uint gc_id() { return _gc_id; }
 712 };
 713 
 714 // Worker threads are named and have an id of an assigned work.
 715 class WorkerThread: public NamedThread {
 716  private:
 717   uint _id;
 718  public:
 719   WorkerThread() : _id(0)               { }
 720   virtual bool is_Worker_thread() const { return true; }
 721 
 722   virtual WorkerThread* as_Worker_thread() const {
 723     assert(is_Worker_thread(), "Dubious cast to WorkerThread*?");
 724     return (WorkerThread*) this;
 725   }
 726 
 727   void set_id(uint work_id)             { _id = work_id; }
 728   uint id() const                       { return _id; }
 729 };
 730 
 731 // A single WatcherThread is used for simulating timer interrupts.
 732 class WatcherThread: public Thread {
 733   friend class VMStructs;
 734  public:
 735   virtual void run();
 736 
 737  private:
 738   static WatcherThread* _watcher_thread;
 739 
 740   static bool _startable;
 741   // volatile due to at least one lock-free read
 742   volatile static bool _should_terminate;
 743  public:
 744   enum SomeConstants {
 745     delay_interval = 10                          // interrupt delay in milliseconds
 746   };
 747 
 748   // Constructor
 749   WatcherThread();
 750 
 751   // No destruction allowed
 752   ~WatcherThread() {
 753     guarantee(false, "WatcherThread deletion must fix the race with VM termination");
 754   }
 755 
 756   // Tester
 757   bool is_Watcher_thread() const                 { return true; }
 758 
 759   // Printing
 760   char* name() const { return (char*)"VM Periodic Task Thread"; }
 761   void print_on(outputStream* st) const;
 762   void unpark();
 763 
 764   // Returns the single instance of WatcherThread
 765   static WatcherThread* watcher_thread()         { return _watcher_thread; }
 766 
 767   // Create and start the single instance of WatcherThread, or stop it on shutdown
 768   static void start();
 769   static void stop();
 770   // Only allow start once the VM is sufficiently initialized
 771   // Otherwise the first task to enroll will trigger the start
 772   static void make_startable();
 773  private:
 774   int sleep() const;
 775 };
 776 
 777 
 778 class CompilerThread;
 779 
 780 typedef void (*ThreadFunction)(JavaThread*, TRAPS);
 781 
 782 class JavaThread: public Thread {
 783   friend class VMStructs;
 784   friend class JVMCIVMStructs;
 785   friend class WhiteBox;
 786  private:
 787   JavaThread*    _next;                          // The next thread in the Threads list
 788   oop            _threadObj;                     // The Java level thread object
 789 
 790 #ifdef ASSERT
 791  private:
 792   int _java_call_counter;
 793 
 794  public:
 795   int  java_call_counter()                       { return _java_call_counter; }
 796   void inc_java_call_counter()                   { _java_call_counter++; }
 797   void dec_java_call_counter() {
 798     assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
 799     _java_call_counter--;
 800   }
 801  private:  // restore original namespace restriction
 802 #endif  // ifdef ASSERT
 803 
 804 #ifndef PRODUCT
 805  public:
 806   enum {
 807     jump_ring_buffer_size = 16
 808   };
 809  private:  // restore original namespace restriction
 810 #endif
 811 
 812   JavaFrameAnchor _anchor;                       // Encapsulation of current java frame and it state
 813 
 814   ThreadFunction _entry_point;
 815 
 816   JNIEnv        _jni_environment;
 817 
 818   // Deopt support
 819   DeoptResourceMark*  _deopt_mark;               // Holds special ResourceMark for deoptimization
 820 
 821   intptr_t*      _must_deopt_id;                 // id of frame that needs to be deopted once we
 822                                                  // transition out of native
 823   CompiledMethod*       _deopt_nmethod;         // CompiledMethod that is currently being deoptimized
 824   vframeArray*  _vframe_array_head;              // Holds the heap of the active vframeArrays
 825   vframeArray*  _vframe_array_last;              // Holds last vFrameArray we popped
 826   // Because deoptimization is lazy we must save jvmti requests to set locals
 827   // in compiled frames until we deoptimize and we have an interpreter frame.
 828   // This holds the pointer to array (yeah like there might be more than one) of
 829   // description of compiled vframes that have locals that need to be updated.
 830   GrowableArray<jvmtiDeferredLocalVariableSet*>* _deferred_locals_updates;
 831 
 832   // Handshake value for fixing 6243940. We need a place for the i2c
 833   // adapter to store the callee Method*. This value is NEVER live
 834   // across a gc point so it does NOT have to be gc'd
 835   // The handshake is open ended since we can't be certain that it will
 836   // be NULLed. This is because we rarely ever see the race and end up
 837   // in handle_wrong_method which is the backend of the handshake. See
 838   // code in i2c adapters and handle_wrong_method.
 839 
 840   Method*       _callee_target;
 841 
 842   // Used to pass back results to the interpreter or generated code running Java code.
 843   oop           _vm_result;    // oop result is GC-preserved
 844   Metadata*     _vm_result_2;  // non-oop result
 845 
 846   // See ReduceInitialCardMarks: this holds the precise space interval of
 847   // the most recent slow path allocation for which compiled code has
 848   // elided card-marks for performance along the fast-path.
 849   MemRegion     _deferred_card_mark;
 850 
 851   MonitorChunk* _monitor_chunks;                 // Contains the off stack monitors
 852                                                  // allocated during deoptimization
 853                                                  // and by JNI_MonitorEnter/Exit
 854 
 855   // Async. requests support
 856   enum AsyncRequests {
 857     _no_async_condition = 0,
 858     _async_exception,
 859     _async_unsafe_access_error
 860   };
 861   AsyncRequests _special_runtime_exit_condition; // Enum indicating pending async. request
 862   oop           _pending_async_exception;
 863 
 864   // Safepoint support
 865  public:                                         // Expose _thread_state for SafeFetchInt()
 866   volatile JavaThreadState _thread_state;
 867  private:
 868   ThreadSafepointState *_safepoint_state;        // Holds information about a thread during a safepoint
 869   address               _saved_exception_pc;     // Saved pc of instruction where last implicit exception happened
 870 
 871   // JavaThread termination support
 872   enum TerminatedTypes {
 873     _not_terminated = 0xDEAD - 2,
 874     _thread_exiting,                             // JavaThread::exit() has been called for this thread
 875     _thread_terminated,                          // JavaThread is removed from thread list
 876     _vm_exited                                   // JavaThread is still executing native code, but VM is terminated
 877                                                  // only VM_Exit can set _vm_exited
 878   };
 879 
 880   // In general a JavaThread's _terminated field transitions as follows:
 881   //
 882   //   _not_terminated => _thread_exiting => _thread_terminated
 883   //
 884   // _vm_exited is a special value to cover the case of a JavaThread
 885   // executing native code after the VM itself is terminated.
 886   volatile TerminatedTypes _terminated;
 887   // suspend/resume support
 888   volatile bool         _suspend_equivalent;     // Suspend equivalent condition
 889   jint                  _in_deopt_handler;       // count of deoptimization
 890                                                  // handlers thread is in
 891   volatile bool         _doing_unsafe_access;    // Thread may fault due to unsafe access
 892   bool                  _do_not_unlock_if_synchronized;  // Do not unlock the receiver of a synchronized method (since it was
 893                                                          // never locked) when throwing an exception. Used by interpreter only.
 894 
 895   // JNI attach states:
 896   enum JNIAttachStates {
 897     _not_attaching_via_jni = 1,  // thread is not attaching via JNI
 898     _attaching_via_jni,          // thread is attaching via JNI
 899     _attached_via_jni            // thread has attached via JNI
 900   };
 901 
 902   // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
 903   // A native thread that is attaching via JNI starts with a value
 904   // of _attaching_via_jni and transitions to _attached_via_jni.
 905   volatile JNIAttachStates _jni_attach_state;
 906 
 907  public:
 908   // State of the stack guard pages for this thread.
 909   enum StackGuardState {
 910     stack_guard_unused,         // not needed
 911     stack_guard_reserved_disabled,
 912     stack_guard_yellow_reserved_disabled,// disabled (temporarily) after stack overflow
 913     stack_guard_enabled         // enabled
 914   };
 915 
 916  private:
 917 
 918 #if INCLUDE_JVMCI
 919   // The _pending_* fields below are used to communicate extra information
 920   // from an uncommon trap in JVMCI compiled code to the uncommon trap handler.
 921 
 922   // Communicates the DeoptReason and DeoptAction of the uncommon trap
 923   int       _pending_deoptimization;
 924 
 925   // Specifies whether the uncommon trap is to bci 0 of a synchronized method
 926   // before the monitor has been acquired.
 927   bool      _pending_monitorenter;
 928 
 929   // Specifies if the DeoptReason for the last uncommon trap was Reason_transfer_to_interpreter
 930   bool      _pending_transfer_to_interpreter;
 931 
 932   // Guard for re-entrant call to JVMCIRuntime::adjust_comp_level
 933   bool      _adjusting_comp_level;
 934 
 935   // An object that JVMCI compiled code can use to further describe and
 936   // uniquely identify the  speculative optimization guarded by the uncommon trap
 937   oop       _pending_failed_speculation;
 938 
 939   // These fields are mutually exclusive in terms of live ranges.
 940   union {
 941     // Communicates the pc at which the most recent implicit exception occurred
 942     // from the signal handler to a deoptimization stub.
 943     address   _implicit_exception_pc;
 944 
 945     // Communicates an alternative call target to an i2c stub from a JavaCall .
 946     address   _alternate_call_target;
 947   } _jvmci;
 948 
 949   // Support for high precision, thread sensitive counters in JVMCI compiled code.
 950   jlong*    _jvmci_counters;
 951 
 952  public:
 953   static jlong* _jvmci_old_thread_counters;
 954   static void collect_counters(typeArrayOop array);
 955  private:
 956 #endif // INCLUDE_JVMCI
 957 
 958   StackGuardState  _stack_guard_state;
 959 
 960   // Precompute the limit of the stack as used in stack overflow checks.
 961   // We load it from here to simplify the stack overflow check in assembly.
 962   address          _stack_overflow_limit;
 963   address          _reserved_stack_activation;
 964 
 965   // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
 966   // used to temp. parsing values into and out of the runtime system during exception handling for compiled
 967   // code)
 968   volatile oop     _exception_oop;               // Exception thrown in compiled code
 969   volatile address _exception_pc;                // PC where exception happened
 970   volatile address _exception_handler_pc;        // PC for handler of exception
 971   volatile int     _is_method_handle_return;     // true (== 1) if the current exception PC is a MethodHandle call site.
 972 
 973  private:
 974   // support for JNI critical regions
 975   jint    _jni_active_critical;                  // count of entries into JNI critical region
 976 
 977   // Checked JNI: function name requires exception check
 978   char* _pending_jni_exception_check_fn;
 979 
 980   // For deadlock detection.
 981   int _depth_first_number;
 982 
 983   // JVMTI PopFrame support
 984   // This is set to popframe_pending to signal that top Java frame should be popped immediately
 985   int _popframe_condition;
 986 
 987   // If reallocation of scalar replaced objects fails, we throw OOM
 988   // and during exception propagation, pop the top
 989   // _frames_to_pop_failed_realloc frames, the ones that reference
 990   // failed reallocations.
 991   int _frames_to_pop_failed_realloc;
 992 
 993 #ifndef PRODUCT
 994   int _jmp_ring_index;
 995   struct {
 996     // We use intptr_t instead of address so debugger doesn't try and display strings
 997     intptr_t _target;
 998     intptr_t _instruction;
 999     const char*  _file;
1000     int _line;
1001   }   _jmp_ring[jump_ring_buffer_size];
1002 #endif // PRODUCT
1003 
1004 #if INCLUDE_ALL_GCS
1005   // Support for G1 barriers
1006 
1007   SATBMarkQueue _satb_mark_queue;        // Thread-local log for SATB barrier.
1008   // Set of all such queues.
1009   static SATBMarkQueueSet _satb_mark_queue_set;
1010 
1011   DirtyCardQueue _dirty_card_queue;      // Thread-local log for dirty cards.
1012   // Set of all such queues.
1013   static DirtyCardQueueSet _dirty_card_queue_set;
1014 
1015   void flush_barrier_queues();
1016 #endif // INCLUDE_ALL_GCS
1017 
1018   friend class VMThread;
1019   friend class ThreadWaitTransition;
1020   friend class VM_Exit;
1021 
1022   void initialize();                             // Initialized the instance variables
1023 
1024  public:
1025   // Constructor
1026   JavaThread(bool is_attaching_via_jni = false); // for main thread and JNI attached threads
1027   JavaThread(ThreadFunction entry_point, size_t stack_size = 0);
1028   ~JavaThread();
1029 
1030 #ifdef ASSERT
1031   // verify this JavaThread hasn't be published in the Threads::list yet
1032   void verify_not_published();
1033 #endif
1034 
1035   //JNI functiontable getter/setter for JVMTI jni function table interception API.
1036   void set_jni_functions(struct JNINativeInterface_* functionTable) {
1037     _jni_environment.functions = functionTable;
1038   }
1039   struct JNINativeInterface_* get_jni_functions() {
1040     return (struct JNINativeInterface_ *)_jni_environment.functions;
1041   }
1042 
1043   // This function is called at thread creation to allow
1044   // platform specific thread variables to be initialized.
1045   void cache_global_variables();
1046 
1047   // Executes Shutdown.shutdown()
1048   void invoke_shutdown_hooks();
1049 
1050   // Cleanup on thread exit
1051   enum ExitType {
1052     normal_exit,
1053     jni_detach
1054   };
1055   void exit(bool destroy_vm, ExitType exit_type = normal_exit);
1056 
1057   void cleanup_failed_attach_current_thread();
1058 
1059   // Testers
1060   virtual bool is_Java_thread() const            { return true;  }
1061   virtual bool can_call_java() const             { return true; }
1062 
1063   // Thread chain operations
1064   JavaThread* next() const                       { return _next; }
1065   void set_next(JavaThread* p)                   { _next = p; }
1066 
1067   // Thread oop. threadObj() can be NULL for initial JavaThread
1068   // (or for threads attached via JNI)
1069   oop threadObj() const                          { return _threadObj; }
1070   void set_threadObj(oop p)                      { _threadObj = p; }
1071 
1072   ThreadPriority java_priority() const;          // Read from threadObj()
1073 
1074   // Prepare thread and add to priority queue.  If a priority is
1075   // not specified, use the priority of the thread object. Threads_lock
1076   // must be held while this function is called.
1077   void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
1078   void prepare_ext();
1079 
1080   void set_saved_exception_pc(address pc)        { _saved_exception_pc = pc; }
1081   address saved_exception_pc()                   { return _saved_exception_pc; }
1082 
1083 
1084   ThreadFunction entry_point() const             { return _entry_point; }
1085 
1086   // Allocates a new Java level thread object for this thread. thread_name may be NULL.
1087   void allocate_threadObj(Handle thread_group, const char* thread_name, bool daemon, TRAPS);
1088 
1089   // Last frame anchor routines
1090 
1091   JavaFrameAnchor* frame_anchor(void)            { return &_anchor; }
1092 
1093   // last_Java_sp
1094   bool has_last_Java_frame() const               { return _anchor.has_last_Java_frame(); }
1095   intptr_t* last_Java_sp() const                 { return _anchor.last_Java_sp(); }
1096 
1097   // last_Java_pc
1098 
1099   address last_Java_pc(void)                     { return _anchor.last_Java_pc(); }
1100 
1101   // Safepoint support
1102 #if !(defined(PPC64) || defined(AARCH64))
1103   JavaThreadState thread_state() const           { return _thread_state; }
1104   void set_thread_state(JavaThreadState s)       { _thread_state = s;    }
1105 #else
1106   // Use membars when accessing volatile _thread_state. See
1107   // Threads::create_vm() for size checks.
1108   inline JavaThreadState thread_state() const;
1109   inline void set_thread_state(JavaThreadState s);
1110 #endif
1111   ThreadSafepointState *safepoint_state() const  { return _safepoint_state; }
1112   void set_safepoint_state(ThreadSafepointState *state) { _safepoint_state = state; }
1113   bool is_at_poll_safepoint()                    { return _safepoint_state->is_at_poll_safepoint(); }
1114 
1115   // thread has called JavaThread::exit() or is terminated
1116   bool is_exiting()                              { return _terminated == _thread_exiting || is_terminated(); }
1117   // thread is terminated (no longer on the threads list); we compare
1118   // against the two non-terminated values so that a freed JavaThread
1119   // will also be considered terminated.
1120   bool is_terminated()                           { return _terminated != _not_terminated && _terminated != _thread_exiting; }
1121   void set_terminated(TerminatedTypes t)         { _terminated = t; }
1122   // special for Threads::remove() which is static:
1123   void set_terminated_value()                    { _terminated = _thread_terminated; }
1124   void block_if_vm_exited();
1125 
1126   bool doing_unsafe_access()                     { return _doing_unsafe_access; }
1127   void set_doing_unsafe_access(bool val)         { _doing_unsafe_access = val; }
1128 
1129   bool do_not_unlock_if_synchronized()             { return _do_not_unlock_if_synchronized; }
1130   void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
1131 
1132   // Suspend/resume support for JavaThread
1133  private:
1134   inline void set_ext_suspended();
1135   inline void clear_ext_suspended();
1136 
1137  public:
1138   void java_suspend();
1139   void java_resume();
1140   int  java_suspend_self();
1141 
1142   void check_and_wait_while_suspended() {
1143     assert(JavaThread::current() == this, "sanity check");
1144 
1145     bool do_self_suspend;
1146     do {
1147       // were we externally suspended while we were waiting?
1148       do_self_suspend = handle_special_suspend_equivalent_condition();
1149       if (do_self_suspend) {
1150         // don't surprise the thread that suspended us by returning
1151         java_suspend_self();
1152         set_suspend_equivalent();
1153       }
1154     } while (do_self_suspend);
1155   }
1156   static void check_safepoint_and_suspend_for_native_trans(JavaThread *thread);
1157   // Check for async exception in addition to safepoint and suspend request.
1158   static void check_special_condition_for_native_trans(JavaThread *thread);
1159 
1160   // Same as check_special_condition_for_native_trans but finishes the
1161   // transition into thread_in_Java mode so that it can potentially
1162   // block.
1163   static void check_special_condition_for_native_trans_and_transition(JavaThread *thread);
1164 
1165   bool is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits);
1166   bool is_ext_suspend_completed_with_lock(uint32_t *bits) {
1167     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1168     // Warning: is_ext_suspend_completed() may temporarily drop the
1169     // SR_lock to allow the thread to reach a stable thread state if
1170     // it is currently in a transient thread state.
1171     return is_ext_suspend_completed(false /* !called_by_wait */,
1172                                     SuspendRetryDelay, bits);
1173   }
1174 
1175   // We cannot allow wait_for_ext_suspend_completion() to run forever or
1176   // we could hang. SuspendRetryCount and SuspendRetryDelay are normally
1177   // passed as the count and delay parameters. Experiments with specific
1178   // calls to wait_for_ext_suspend_completion() can be done by passing
1179   // other values in the code. Experiments with all calls can be done
1180   // via the appropriate -XX options.
1181   bool wait_for_ext_suspend_completion(int count, int delay, uint32_t *bits);
1182 
1183   inline void set_external_suspend();
1184   inline void clear_external_suspend();
1185 
1186   inline void set_deopt_suspend();
1187   inline void clear_deopt_suspend();
1188   bool is_deopt_suspend()         { return (_suspend_flags & _deopt_suspend) != 0; }
1189 
1190   bool is_external_suspend() const {
1191     return (_suspend_flags & _external_suspend) != 0;
1192   }
1193   // Whenever a thread transitions from native to vm/java it must suspend
1194   // if external|deopt suspend is present.
1195   bool is_suspend_after_native() const {
1196     return (_suspend_flags & (_external_suspend | _deopt_suspend)) != 0;
1197   }
1198 
1199   // external suspend request is completed
1200   bool is_ext_suspended() const {
1201     return (_suspend_flags & _ext_suspended) != 0;
1202   }
1203 
1204   bool is_external_suspend_with_lock() const {
1205     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1206     return is_external_suspend();
1207   }
1208 
1209   // Special method to handle a pending external suspend request
1210   // when a suspend equivalent condition lifts.
1211   bool handle_special_suspend_equivalent_condition() {
1212     assert(is_suspend_equivalent(),
1213            "should only be called in a suspend equivalence condition");
1214     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1215     bool ret = is_external_suspend();
1216     if (!ret) {
1217       // not about to self-suspend so clear suspend equivalence
1218       clear_suspend_equivalent();
1219     }
1220     // implied else:
1221     // We have a pending external suspend request so we leave the
1222     // suspend_equivalent flag set until java_suspend_self() sets
1223     // the ext_suspended flag and clears the suspend_equivalent
1224     // flag. This insures that wait_for_ext_suspend_completion()
1225     // will return consistent values.
1226     return ret;
1227   }
1228 
1229   // utility methods to see if we are doing some kind of suspension
1230   bool is_being_ext_suspended() const            {
1231     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1232     return is_ext_suspended() || is_external_suspend();
1233   }
1234 
1235   bool is_suspend_equivalent() const             { return _suspend_equivalent; }
1236 
1237   void set_suspend_equivalent()                  { _suspend_equivalent = true; }
1238   void clear_suspend_equivalent()                { _suspend_equivalent = false; }
1239 
1240   // Thread.stop support
1241   void send_thread_stop(oop throwable);
1242   AsyncRequests clear_special_runtime_exit_condition() {
1243     AsyncRequests x = _special_runtime_exit_condition;
1244     _special_runtime_exit_condition = _no_async_condition;
1245     return x;
1246   }
1247 
1248   // Are any async conditions present?
1249   bool has_async_condition() { return (_special_runtime_exit_condition != _no_async_condition); }
1250 
1251   void check_and_handle_async_exceptions(bool check_unsafe_error = true);
1252 
1253   // these next two are also used for self-suspension and async exception support
1254   void handle_special_runtime_exit_condition(bool check_asyncs = true);
1255 
1256   // Return true if JavaThread has an asynchronous condition or
1257   // if external suspension is requested.
1258   bool has_special_runtime_exit_condition() {
1259     // Because we don't use is_external_suspend_with_lock
1260     // it is possible that we won't see an asynchronous external suspend
1261     // request that has just gotten started, i.e., SR_lock grabbed but
1262     // _external_suspend field change either not made yet or not visible
1263     // yet. However, this is okay because the request is asynchronous and
1264     // we will see the new flag value the next time through. It's also
1265     // possible that the external suspend request is dropped after
1266     // we have checked is_external_suspend(), we will recheck its value
1267     // under SR_lock in java_suspend_self().
1268     return (_special_runtime_exit_condition != _no_async_condition) ||
1269             is_external_suspend() || is_deopt_suspend() || is_trace_suspend();
1270   }
1271 
1272   void set_pending_unsafe_access_error()          { _special_runtime_exit_condition = _async_unsafe_access_error; }
1273 
1274   inline void set_pending_async_exception(oop e);
1275 
1276   // Fast-locking support
1277   bool is_lock_owned(address adr) const;
1278 
1279   // Accessors for vframe array top
1280   // The linked list of vframe arrays are sorted on sp. This means when we
1281   // unpack the head must contain the vframe array to unpack.
1282   void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
1283   vframeArray* vframe_array_head() const         { return _vframe_array_head;  }
1284 
1285   // Side structure for deferring update of java frame locals until deopt occurs
1286   GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred_locals() const { return _deferred_locals_updates; }
1287   void set_deferred_locals(GrowableArray<jvmtiDeferredLocalVariableSet *>* vf) { _deferred_locals_updates = vf; }
1288 
1289   // These only really exist to make debugging deopt problems simpler
1290 
1291   void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
1292   vframeArray* vframe_array_last() const         { return _vframe_array_last;  }
1293 
1294   // The special resourceMark used during deoptimization
1295 
1296   void set_deopt_mark(DeoptResourceMark* value)  { _deopt_mark = value; }
1297   DeoptResourceMark* deopt_mark(void)            { return _deopt_mark; }
1298 
1299   intptr_t* must_deopt_id()                      { return _must_deopt_id; }
1300   void     set_must_deopt_id(intptr_t* id)       { _must_deopt_id = id; }
1301   void     clear_must_deopt_id()                 { _must_deopt_id = NULL; }
1302 
1303   void set_deopt_compiled_method(CompiledMethod* nm)  { _deopt_nmethod = nm; }
1304   CompiledMethod* deopt_compiled_method()        { return _deopt_nmethod; }
1305 
1306   Method*    callee_target() const               { return _callee_target; }
1307   void set_callee_target  (Method* x)          { _callee_target   = x; }
1308 
1309   // Oop results of vm runtime calls
1310   oop  vm_result() const                         { return _vm_result; }
1311   void set_vm_result  (oop x)                    { _vm_result   = x; }
1312 
1313   Metadata*    vm_result_2() const               { return _vm_result_2; }
1314   void set_vm_result_2  (Metadata* x)          { _vm_result_2   = x; }
1315 
1316   MemRegion deferred_card_mark() const           { return _deferred_card_mark; }
1317   void set_deferred_card_mark(MemRegion mr)      { _deferred_card_mark = mr;   }
1318 
1319 #if INCLUDE_JVMCI
1320   int  pending_deoptimization() const             { return _pending_deoptimization; }
1321   oop  pending_failed_speculation() const         { return _pending_failed_speculation; }
1322   bool adjusting_comp_level() const               { return _adjusting_comp_level; }
1323   void set_adjusting_comp_level(bool b)           { _adjusting_comp_level = b; }
1324   bool has_pending_monitorenter() const           { return _pending_monitorenter; }
1325   void set_pending_monitorenter(bool b)           { _pending_monitorenter = b; }
1326   void set_pending_deoptimization(int reason)     { _pending_deoptimization = reason; }
1327   void set_pending_failed_speculation(oop failed_speculation) { _pending_failed_speculation = failed_speculation; }
1328   void set_pending_transfer_to_interpreter(bool b) { _pending_transfer_to_interpreter = b; }
1329   void set_jvmci_alternate_call_target(address a) { assert(_jvmci._alternate_call_target == NULL, "must be"); _jvmci._alternate_call_target = a; }
1330   void set_jvmci_implicit_exception_pc(address a) { assert(_jvmci._implicit_exception_pc == NULL, "must be"); _jvmci._implicit_exception_pc = a; }
1331 #endif // INCLUDE_JVMCI
1332 
1333   // Exception handling for compiled methods
1334   oop      exception_oop() const                 { return _exception_oop; }
1335   address  exception_pc() const                  { return _exception_pc; }
1336   address  exception_handler_pc() const          { return _exception_handler_pc; }
1337   bool     is_method_handle_return() const       { return _is_method_handle_return == 1; }
1338 
1339   void set_exception_oop(oop o)                  { (void)const_cast<oop&>(_exception_oop = o); }
1340   void set_exception_pc(address a)               { _exception_pc = a; }
1341   void set_exception_handler_pc(address a)       { _exception_handler_pc = a; }
1342   void set_is_method_handle_return(bool value)   { _is_method_handle_return = value ? 1 : 0; }
1343 
1344   void clear_exception_oop_and_pc() {
1345     set_exception_oop(NULL);
1346     set_exception_pc(NULL);
1347   }
1348 
1349   // Stack overflow support
1350   //
1351   //  (small addresses)
1352   //
1353   //  --  <-- stack_end()                   ---
1354   //  |                                      |
1355   //  |  red pages                           |
1356   //  |                                      |
1357   //  --  <-- stack_red_zone_base()          |
1358   //  |                                      |
1359   //  |                                     guard
1360   //  |  yellow pages                       zone
1361   //  |                                      |
1362   //  |                                      |
1363   //  --  <-- stack_yellow_zone_base()       |
1364   //  |                                      |
1365   //  |                                      |
1366   //  |  reserved pages                      |
1367   //  |                                      |
1368   //  --  <-- stack_reserved_zone_base()    ---      ---
1369   //                                                 /|\  shadow     <--  stack_overflow_limit() (somewhere in here)
1370   //                                                  |   zone
1371   //                                                 \|/  size
1372   //  some untouched memory                          ---
1373   //
1374   //
1375   //  --
1376   //  |
1377   //  |  shadow zone
1378   //  |
1379   //  --
1380   //  x    frame n
1381   //  --
1382   //  x    frame n-1
1383   //  x
1384   //  --
1385   //  ...
1386   //
1387   //  --
1388   //  x    frame 0
1389   //  --  <-- stack_base()
1390   //
1391   //  (large addresses)
1392   //
1393 
1394  private:
1395   // These values are derived from flags StackRedPages, StackYellowPages,
1396   // StackReservedPages and StackShadowPages. The zone size is determined
1397   // ergonomically if page_size > 4K.
1398   static size_t _stack_red_zone_size;
1399   static size_t _stack_yellow_zone_size;
1400   static size_t _stack_reserved_zone_size;
1401   static size_t _stack_shadow_zone_size;
1402  public:
1403   inline size_t stack_available(address cur_sp);
1404 
1405   static size_t stack_red_zone_size() {
1406     assert(_stack_red_zone_size > 0, "Don't call this before the field is initialized.");
1407     return _stack_red_zone_size;
1408   }
1409   static void set_stack_red_zone_size(size_t s) {
1410     assert(is_aligned(s, os::vm_page_size()),
1411            "We can not protect if the red zone size is not page aligned.");
1412     assert(_stack_red_zone_size == 0, "This should be called only once.");
1413     _stack_red_zone_size = s;
1414   }
1415   address stack_red_zone_base() {
1416     return (address)(stack_end() + stack_red_zone_size());
1417   }
1418   bool in_stack_red_zone(address a) {
1419     return a <= stack_red_zone_base() && a >= stack_end();
1420   }
1421 
1422   static size_t stack_yellow_zone_size() {
1423     assert(_stack_yellow_zone_size > 0, "Don't call this before the field is initialized.");
1424     return _stack_yellow_zone_size;
1425   }
1426   static void set_stack_yellow_zone_size(size_t s) {
1427     assert(is_aligned(s, os::vm_page_size()),
1428            "We can not protect if the yellow zone size is not page aligned.");
1429     assert(_stack_yellow_zone_size == 0, "This should be called only once.");
1430     _stack_yellow_zone_size = s;
1431   }
1432 
1433   static size_t stack_reserved_zone_size() {
1434     // _stack_reserved_zone_size may be 0. This indicates the feature is off.
1435     return _stack_reserved_zone_size;
1436   }
1437   static void set_stack_reserved_zone_size(size_t s) {
1438     assert(is_aligned(s, os::vm_page_size()),
1439            "We can not protect if the reserved zone size is not page aligned.");
1440     assert(_stack_reserved_zone_size == 0, "This should be called only once.");
1441     _stack_reserved_zone_size = s;
1442   }
1443   address stack_reserved_zone_base() {
1444     return (address)(stack_end() +
1445                      (stack_red_zone_size() + stack_yellow_zone_size() + stack_reserved_zone_size()));
1446   }
1447   bool in_stack_reserved_zone(address a) {
1448     return (a <= stack_reserved_zone_base()) &&
1449            (a >= (address)((intptr_t)stack_reserved_zone_base() - stack_reserved_zone_size()));
1450   }
1451 
1452   static size_t stack_yellow_reserved_zone_size() {
1453     return _stack_yellow_zone_size + _stack_reserved_zone_size;
1454   }
1455   bool in_stack_yellow_reserved_zone(address a) {
1456     return (a <= stack_reserved_zone_base()) && (a >= stack_red_zone_base());
1457   }
1458 
1459   // Size of red + yellow + reserved zones.
1460   static size_t stack_guard_zone_size() {
1461     return stack_red_zone_size() + stack_yellow_reserved_zone_size();
1462   }
1463 
1464   static size_t stack_shadow_zone_size() {
1465     assert(_stack_shadow_zone_size > 0, "Don't call this before the field is initialized.");
1466     return _stack_shadow_zone_size;
1467   }
1468   static void set_stack_shadow_zone_size(size_t s) {
1469     // The shadow area is not allocated or protected, so
1470     // it needs not be page aligned.
1471     // But the stack bang currently assumes that it is a
1472     // multiple of page size. This guarantees that the bang
1473     // loop touches all pages in the shadow zone.
1474     // This can be guaranteed differently, as well.  E.g., if
1475     // the page size is a multiple of 4K, banging in 4K steps
1476     // suffices to touch all pages. (Some pages are banged
1477     // several times, though.)
1478     assert(is_aligned(s, os::vm_page_size()),
1479            "Stack bang assumes multiple of page size.");
1480     assert(_stack_shadow_zone_size == 0, "This should be called only once.");
1481     _stack_shadow_zone_size = s;
1482   }
1483 
1484   void create_stack_guard_pages();
1485   void remove_stack_guard_pages();
1486 
1487   void enable_stack_reserved_zone();
1488   void disable_stack_reserved_zone();
1489   void enable_stack_yellow_reserved_zone();
1490   void disable_stack_yellow_reserved_zone();
1491   void enable_stack_red_zone();
1492   void disable_stack_red_zone();
1493 
1494   inline bool stack_guard_zone_unused();
1495   inline bool stack_yellow_reserved_zone_disabled();
1496   inline bool stack_reserved_zone_disabled();
1497   inline bool stack_guards_enabled();
1498 
1499   address reserved_stack_activation() const { return _reserved_stack_activation; }
1500   void set_reserved_stack_activation(address addr) {
1501     assert(_reserved_stack_activation == stack_base()
1502             || _reserved_stack_activation == NULL
1503             || addr == stack_base(), "Must not be set twice");
1504     _reserved_stack_activation = addr;
1505   }
1506 
1507   // Attempt to reguard the stack after a stack overflow may have occurred.
1508   // Returns true if (a) guard pages are not needed on this thread, (b) the
1509   // pages are already guarded, or (c) the pages were successfully reguarded.
1510   // Returns false if there is not enough stack space to reguard the pages, in
1511   // which case the caller should unwind a frame and try again.  The argument
1512   // should be the caller's (approximate) sp.
1513   bool reguard_stack(address cur_sp);
1514   // Similar to above but see if current stackpoint is out of the guard area
1515   // and reguard if possible.
1516   bool reguard_stack(void);
1517 
1518   address stack_overflow_limit() { return _stack_overflow_limit; }
1519   void set_stack_overflow_limit() {
1520     _stack_overflow_limit =
1521       stack_end() + MAX2(JavaThread::stack_guard_zone_size(), JavaThread::stack_shadow_zone_size());
1522   }
1523 
1524   // Misc. accessors/mutators
1525   void set_do_not_unlock(void)                   { _do_not_unlock_if_synchronized = true; }
1526   void clr_do_not_unlock(void)                   { _do_not_unlock_if_synchronized = false; }
1527   bool do_not_unlock(void)                       { return _do_not_unlock_if_synchronized; }
1528 
1529 #ifndef PRODUCT
1530   void record_jump(address target, address instr, const char* file, int line);
1531 #endif // PRODUCT
1532 
1533   // For assembly stub generation
1534   static ByteSize threadObj_offset()             { return byte_offset_of(JavaThread, _threadObj); }
1535 #ifndef PRODUCT
1536   static ByteSize jmp_ring_index_offset()        { return byte_offset_of(JavaThread, _jmp_ring_index); }
1537   static ByteSize jmp_ring_offset()              { return byte_offset_of(JavaThread, _jmp_ring); }
1538 #endif // PRODUCT
1539   static ByteSize jni_environment_offset()       { return byte_offset_of(JavaThread, _jni_environment); }
1540   static ByteSize pending_jni_exception_check_fn_offset() {
1541     return byte_offset_of(JavaThread, _pending_jni_exception_check_fn);
1542   }
1543   static ByteSize last_Java_sp_offset() {
1544     return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
1545   }
1546   static ByteSize last_Java_pc_offset() {
1547     return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
1548   }
1549   static ByteSize frame_anchor_offset() {
1550     return byte_offset_of(JavaThread, _anchor);
1551   }
1552   static ByteSize callee_target_offset()         { return byte_offset_of(JavaThread, _callee_target); }
1553   static ByteSize vm_result_offset()             { return byte_offset_of(JavaThread, _vm_result); }
1554   static ByteSize vm_result_2_offset()           { return byte_offset_of(JavaThread, _vm_result_2); }
1555   static ByteSize thread_state_offset()          { return byte_offset_of(JavaThread, _thread_state); }
1556   static ByteSize saved_exception_pc_offset()    { return byte_offset_of(JavaThread, _saved_exception_pc); }
1557   static ByteSize osthread_offset()              { return byte_offset_of(JavaThread, _osthread); }
1558 #if INCLUDE_JVMCI
1559   static ByteSize pending_deoptimization_offset() { return byte_offset_of(JavaThread, _pending_deoptimization); }
1560   static ByteSize pending_monitorenter_offset()  { return byte_offset_of(JavaThread, _pending_monitorenter); }
1561   static ByteSize pending_failed_speculation_offset() { return byte_offset_of(JavaThread, _pending_failed_speculation); }
1562   static ByteSize jvmci_alternate_call_target_offset() { return byte_offset_of(JavaThread, _jvmci._alternate_call_target); }
1563   static ByteSize jvmci_implicit_exception_pc_offset() { return byte_offset_of(JavaThread, _jvmci._implicit_exception_pc); }
1564   static ByteSize jvmci_counters_offset()        { return byte_offset_of(JavaThread, _jvmci_counters); }
1565 #endif // INCLUDE_JVMCI
1566   static ByteSize exception_oop_offset()         { return byte_offset_of(JavaThread, _exception_oop); }
1567   static ByteSize exception_pc_offset()          { return byte_offset_of(JavaThread, _exception_pc); }
1568   static ByteSize exception_handler_pc_offset()  { return byte_offset_of(JavaThread, _exception_handler_pc); }
1569   static ByteSize stack_overflow_limit_offset()  { return byte_offset_of(JavaThread, _stack_overflow_limit); }
1570   static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); }
1571   static ByteSize stack_guard_state_offset()     { return byte_offset_of(JavaThread, _stack_guard_state); }
1572   static ByteSize reserved_stack_activation_offset() { return byte_offset_of(JavaThread, _reserved_stack_activation); }
1573   static ByteSize suspend_flags_offset()         { return byte_offset_of(JavaThread, _suspend_flags); }
1574 
1575   static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
1576   static ByteSize should_post_on_exceptions_flag_offset() {
1577     return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
1578   }
1579 
1580 #if INCLUDE_ALL_GCS
1581   static ByteSize satb_mark_queue_offset()       { return byte_offset_of(JavaThread, _satb_mark_queue); }
1582   static ByteSize dirty_card_queue_offset()      { return byte_offset_of(JavaThread, _dirty_card_queue); }
1583 #endif // INCLUDE_ALL_GCS
1584 
1585   // Returns the jni environment for this thread
1586   JNIEnv* jni_environment()                      { return &_jni_environment; }
1587 
1588   static JavaThread* thread_from_jni_environment(JNIEnv* env) {
1589     JavaThread *thread_from_jni_env = (JavaThread*)((intptr_t)env - in_bytes(jni_environment_offset()));
1590     // Only return NULL if thread is off the thread list; starting to
1591     // exit should not return NULL.
1592     if (thread_from_jni_env->is_terminated()) {
1593       thread_from_jni_env->block_if_vm_exited();
1594       return NULL;
1595     } else {
1596       return thread_from_jni_env;
1597     }
1598   }
1599 
1600   // JNI critical regions. These can nest.
1601   bool in_critical()    { return _jni_active_critical > 0; }
1602   bool in_last_critical()  { return _jni_active_critical == 1; }
1603   void enter_critical() {
1604     assert(Thread::current() == this ||
1605            (Thread::current()->is_VM_thread() &&
1606            SafepointSynchronize::is_synchronizing()),
1607            "this must be current thread or synchronizing");
1608     _jni_active_critical++;
1609   }
1610   void exit_critical() {
1611     assert(Thread::current() == this, "this must be current thread");
1612     _jni_active_critical--;
1613     assert(_jni_active_critical >= 0, "JNI critical nesting problem?");
1614   }
1615 
1616   // Checked JNI: is the programmer required to check for exceptions, if so specify
1617   // which function name. Returning to a Java frame should implicitly clear the
1618   // pending check, this is done for Native->Java transitions (i.e. user JNI code).
1619   // VM->Java transistions are not cleared, it is expected that JNI code enclosed
1620   // within ThreadToNativeFromVM makes proper exception checks (i.e. VM internal).
1621   bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != NULL; }
1622   void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = NULL; }
1623   const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; }
1624   void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; }
1625 
1626   // For deadlock detection
1627   int depth_first_number() { return _depth_first_number; }
1628   void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
1629 
1630  private:
1631   void set_monitor_chunks(MonitorChunk* monitor_chunks) { _monitor_chunks = monitor_chunks; }
1632 
1633  public:
1634   MonitorChunk* monitor_chunks() const           { return _monitor_chunks; }
1635   void add_monitor_chunk(MonitorChunk* chunk);
1636   void remove_monitor_chunk(MonitorChunk* chunk);
1637   bool in_deopt_handler() const                  { return _in_deopt_handler > 0; }
1638   void inc_in_deopt_handler()                    { _in_deopt_handler++; }
1639   void dec_in_deopt_handler() {
1640     assert(_in_deopt_handler > 0, "mismatched deopt nesting");
1641     if (_in_deopt_handler > 0) { // robustness
1642       _in_deopt_handler--;
1643     }
1644   }
1645 
1646  private:
1647   void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
1648 
1649  public:
1650 
1651   // Frame iteration; calls the function f for all frames on the stack
1652   void frames_do(void f(frame*, const RegisterMap*));
1653 
1654   // Memory operations
1655   void oops_do(OopClosure* f, CodeBlobClosure* cf);
1656 
1657   // Sweeper operations
1658   virtual void nmethods_do(CodeBlobClosure* cf);
1659 
1660   // RedefineClasses Support
1661   void metadata_do(void f(Metadata*));
1662 
1663   // Misc. operations
1664   char* name() const { return (char*)get_thread_name(); }
1665   void print_on(outputStream* st) const;
1666   void print_value();
1667   void print_thread_state_on(outputStream*) const      PRODUCT_RETURN;
1668   void print_thread_state() const                      PRODUCT_RETURN;
1669   void print_on_error(outputStream* st, char* buf, int buflen) const;
1670   void print_name_on_error(outputStream* st, char* buf, int buflen) const;
1671   void verify();
1672   const char* get_thread_name() const;
1673  private:
1674   // factor out low-level mechanics for use in both normal and error cases
1675   const char* get_thread_name_string(char* buf = NULL, int buflen = 0) const;
1676  public:
1677   const char* get_threadgroup_name() const;
1678   const char* get_parent_name() const;
1679 
1680   // Accessing frames
1681   frame last_frame() {
1682     _anchor.make_walkable(this);
1683     return pd_last_frame();
1684   }
1685   javaVFrame* last_java_vframe(RegisterMap* reg_map);
1686 
1687   // Returns method at 'depth' java or native frames down the stack
1688   // Used for security checks
1689   Klass* security_get_caller_class(int depth);
1690 
1691   // Print stack trace in external format
1692   void print_stack_on(outputStream* st);
1693   void print_stack() { print_stack_on(tty); }
1694 
1695   // Print stack traces in various internal formats
1696   void trace_stack()                             PRODUCT_RETURN;
1697   void trace_stack_from(vframe* start_vf)        PRODUCT_RETURN;
1698   void trace_frames()                            PRODUCT_RETURN;
1699   void trace_oops()                              PRODUCT_RETURN;
1700 
1701   // Print an annotated view of the stack frames
1702   void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN;
1703   void validate_frame_layout() {
1704     print_frame_layout(0, true);
1705   }
1706 
1707   // Returns the number of stack frames on the stack
1708   int depth() const;
1709 
1710   // Function for testing deoptimization
1711   void deoptimize();
1712   void make_zombies();
1713 
1714   void deoptimized_wrt_marked_nmethods();
1715 
1716   // Profiling operation (see fprofile.cpp)
1717  public:
1718   bool profile_last_Java_frame(frame* fr);
1719 
1720  private:
1721   ThreadProfiler* _thread_profiler;
1722  private:
1723   friend class FlatProfiler;                    // uses both [gs]et_thread_profiler.
1724   friend class FlatProfilerTask;                // uses get_thread_profiler.
1725   friend class ThreadProfilerMark;              // uses get_thread_profiler.
1726   ThreadProfiler* get_thread_profiler()         { return _thread_profiler; }
1727   ThreadProfiler* set_thread_profiler(ThreadProfiler* tp) {
1728     ThreadProfiler* result = _thread_profiler;
1729     _thread_profiler = tp;
1730     return result;
1731   }
1732 
1733  public:
1734   // Returns the running thread as a JavaThread
1735   static inline JavaThread* current();
1736 
1737   // Returns the active Java thread.  Do not use this if you know you are calling
1738   // from a JavaThread, as it's slower than JavaThread::current.  If called from
1739   // the VMThread, it also returns the JavaThread that instigated the VMThread's
1740   // operation.  You may not want that either.
1741   static JavaThread* active();
1742 
1743   inline CompilerThread* as_CompilerThread();
1744 
1745  public:
1746   virtual void run();
1747   void thread_main_inner();
1748 
1749  private:
1750   // PRIVILEGED STACK
1751   PrivilegedElement*  _privileged_stack_top;
1752   GrowableArray<oop>* _array_for_gc;
1753  public:
1754 
1755   // Returns the privileged_stack information.
1756   PrivilegedElement* privileged_stack_top() const       { return _privileged_stack_top; }
1757   void set_privileged_stack_top(PrivilegedElement *e)   { _privileged_stack_top = e; }
1758   void register_array_for_gc(GrowableArray<oop>* array) { _array_for_gc = array; }
1759 
1760  public:
1761   // Thread local information maintained by JVMTI.
1762   void set_jvmti_thread_state(JvmtiThreadState *value)                           { _jvmti_thread_state = value; }
1763   // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1764   // getter is used to get this JavaThread's JvmtiThreadState if it has
1765   // one which means NULL can be returned. JvmtiThreadState::state_for()
1766   // is used to get the specified JavaThread's JvmtiThreadState if it has
1767   // one or it allocates a new JvmtiThreadState for the JavaThread and
1768   // returns it. JvmtiThreadState::state_for() will return NULL only if
1769   // the specified JavaThread is exiting.
1770   JvmtiThreadState *jvmti_thread_state() const                                   { return _jvmti_thread_state; }
1771   static ByteSize jvmti_thread_state_offset()                                    { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1772   void set_jvmti_get_loaded_classes_closure(JvmtiGetLoadedClassesClosure* value) { _jvmti_get_loaded_classes_closure = value; }
1773   JvmtiGetLoadedClassesClosure* get_jvmti_get_loaded_classes_closure() const     { return _jvmti_get_loaded_classes_closure; }
1774 
1775   // JVMTI PopFrame support
1776   // Setting and clearing popframe_condition
1777   // All of these enumerated values are bits. popframe_pending
1778   // indicates that a PopFrame() has been requested and not yet been
1779   // completed. popframe_processing indicates that that PopFrame() is in
1780   // the process of being completed. popframe_force_deopt_reexecution_bit
1781   // indicates that special handling is required when returning to a
1782   // deoptimized caller.
1783   enum PopCondition {
1784     popframe_inactive                      = 0x00,
1785     popframe_pending_bit                   = 0x01,
1786     popframe_processing_bit                = 0x02,
1787     popframe_force_deopt_reexecution_bit   = 0x04
1788   };
1789   PopCondition popframe_condition()                   { return (PopCondition) _popframe_condition; }
1790   void set_popframe_condition(PopCondition c)         { _popframe_condition = c; }
1791   void set_popframe_condition_bit(PopCondition c)     { _popframe_condition |= c; }
1792   void clear_popframe_condition()                     { _popframe_condition = popframe_inactive; }
1793   static ByteSize popframe_condition_offset()         { return byte_offset_of(JavaThread, _popframe_condition); }
1794   bool has_pending_popframe()                         { return (popframe_condition() & popframe_pending_bit) != 0; }
1795   bool popframe_forcing_deopt_reexecution()           { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
1796   void clear_popframe_forcing_deopt_reexecution()     { _popframe_condition &= ~popframe_force_deopt_reexecution_bit; }
1797 #ifdef CC_INTERP
1798   bool pop_frame_pending(void)                        { return ((_popframe_condition & popframe_pending_bit) != 0); }
1799   void clr_pop_frame_pending(void)                    { _popframe_condition = popframe_inactive; }
1800   bool pop_frame_in_process(void)                     { return ((_popframe_condition & popframe_processing_bit) != 0); }
1801   void set_pop_frame_in_process(void)                 { _popframe_condition |= popframe_processing_bit; }
1802   void clr_pop_frame_in_process(void)                 { _popframe_condition &= ~popframe_processing_bit; }
1803 #endif
1804 
1805   int frames_to_pop_failed_realloc() const            { return _frames_to_pop_failed_realloc; }
1806   void set_frames_to_pop_failed_realloc(int nb)       { _frames_to_pop_failed_realloc = nb; }
1807   void dec_frames_to_pop_failed_realloc()             { _frames_to_pop_failed_realloc--; }
1808 
1809  private:
1810   // Saved incoming arguments to popped frame.
1811   // Used only when popped interpreted frame returns to deoptimized frame.
1812   void*    _popframe_preserved_args;
1813   int      _popframe_preserved_args_size;
1814 
1815  public:
1816   void  popframe_preserve_args(ByteSize size_in_bytes, void* start);
1817   void* popframe_preserved_args();
1818   ByteSize popframe_preserved_args_size();
1819   WordSize popframe_preserved_args_size_in_words();
1820   void  popframe_free_preserved_args();
1821 
1822 
1823  private:
1824   JvmtiThreadState *_jvmti_thread_state;
1825   JvmtiGetLoadedClassesClosure* _jvmti_get_loaded_classes_closure;
1826 
1827   // Used by the interpreter in fullspeed mode for frame pop, method
1828   // entry, method exit and single stepping support. This field is
1829   // only set to non-zero by the VM_EnterInterpOnlyMode VM operation.
1830   // It can be set to zero asynchronously (i.e., without a VM operation
1831   // or a lock) so we have to be very careful.
1832   int               _interp_only_mode;
1833 
1834  public:
1835   // used by the interpreter for fullspeed debugging support (see above)
1836   static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
1837   bool is_interp_only_mode()                { return (_interp_only_mode != 0); }
1838   int get_interp_only_mode()                { return _interp_only_mode; }
1839   void increment_interp_only_mode()         { ++_interp_only_mode; }
1840   void decrement_interp_only_mode()         { --_interp_only_mode; }
1841 
1842   // support for cached flag that indicates whether exceptions need to be posted for this thread
1843   // if this is false, we can avoid deoptimizing when events are thrown
1844   // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
1845  private:
1846   int    _should_post_on_exceptions_flag;
1847 
1848  public:
1849   int   should_post_on_exceptions_flag()  { return _should_post_on_exceptions_flag; }
1850   void  set_should_post_on_exceptions_flag(int val)  { _should_post_on_exceptions_flag = val; }
1851 
1852  private:
1853   ThreadStatistics *_thread_stat;
1854 
1855  public:
1856   ThreadStatistics* get_thread_stat() const    { return _thread_stat; }
1857 
1858   // Return a blocker object for which this thread is blocked parking.
1859   oop current_park_blocker();
1860 
1861  private:
1862   static size_t _stack_size_at_create;
1863 
1864  public:
1865   static inline size_t stack_size_at_create(void) {
1866     return _stack_size_at_create;
1867   }
1868   static inline void set_stack_size_at_create(size_t value) {
1869     _stack_size_at_create = value;
1870   }
1871 
1872 #if INCLUDE_ALL_GCS
1873   // SATB marking queue support
1874   SATBMarkQueue& satb_mark_queue() { return _satb_mark_queue; }
1875   static SATBMarkQueueSet& satb_mark_queue_set() {
1876     return _satb_mark_queue_set;
1877   }
1878 
1879   // Dirty card queue support
1880   DirtyCardQueue& dirty_card_queue() { return _dirty_card_queue; }
1881   static DirtyCardQueueSet& dirty_card_queue_set() {
1882     return _dirty_card_queue_set;
1883   }
1884 #endif // INCLUDE_ALL_GCS
1885 
1886   // This method initializes the SATB and dirty card queues before a
1887   // JavaThread is added to the Java thread list. Right now, we don't
1888   // have to do anything to the dirty card queue (it should have been
1889   // activated when the thread was created), but we have to activate
1890   // the SATB queue if the thread is created while a marking cycle is
1891   // in progress. The activation / de-activation of the SATB queues at
1892   // the beginning / end of a marking cycle is done during safepoints
1893   // so we have to make sure this method is called outside one to be
1894   // able to safely read the active field of the SATB queue set. Right
1895   // now, it is called just before the thread is added to the Java
1896   // thread list in the Threads::add() method. That method is holding
1897   // the Threads_lock which ensures we are outside a safepoint. We
1898   // cannot do the obvious and set the active field of the SATB queue
1899   // when the thread is created given that, in some cases, safepoints
1900   // might happen between the JavaThread constructor being called and the
1901   // thread being added to the Java thread list (an example of this is
1902   // when the structure for the DestroyJavaVM thread is created).
1903 #if INCLUDE_ALL_GCS
1904   void initialize_queues();
1905 #else  // INCLUDE_ALL_GCS
1906   void initialize_queues() { }
1907 #endif // INCLUDE_ALL_GCS
1908 
1909   // Machine dependent stuff
1910 #include OS_CPU_HEADER(thread)
1911 
1912  public:
1913   void set_blocked_on_compilation(bool value) {
1914     _blocked_on_compilation = value;
1915   }
1916 
1917   bool blocked_on_compilation() {
1918     return _blocked_on_compilation;
1919   }
1920  protected:
1921   bool         _blocked_on_compilation;
1922 
1923 
1924   // JSR166 per-thread parker
1925  private:
1926   Parker*    _parker;
1927  public:
1928   Parker*     parker() { return _parker; }
1929 
1930   // Biased locking support
1931  private:
1932   GrowableArray<MonitorInfo*>* _cached_monitor_info;
1933  public:
1934   GrowableArray<MonitorInfo*>* cached_monitor_info() { return _cached_monitor_info; }
1935   void set_cached_monitor_info(GrowableArray<MonitorInfo*>* info) { _cached_monitor_info = info; }
1936 
1937   // clearing/querying jni attach status
1938   bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; }
1939   bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
1940   inline void set_done_attaching_via_jni();
1941 };
1942 
1943 // Inline implementation of JavaThread::current
1944 inline JavaThread* JavaThread::current() {
1945   Thread* thread = Thread::current();
1946   assert(thread->is_Java_thread(), "just checking");
1947   return (JavaThread*)thread;
1948 }
1949 
1950 inline CompilerThread* JavaThread::as_CompilerThread() {
1951   assert(is_Compiler_thread(), "just checking");
1952   return (CompilerThread*)this;
1953 }
1954 
1955 // Dedicated thread to sweep the code cache
1956 class CodeCacheSweeperThread : public JavaThread {
1957   CompiledMethod*       _scanned_compiled_method; // nmethod being scanned by the sweeper
1958  public:
1959   CodeCacheSweeperThread();
1960   // Track the nmethod currently being scanned by the sweeper
1961   void set_scanned_compiled_method(CompiledMethod* cm) {
1962     assert(_scanned_compiled_method == NULL || cm == NULL, "should reset to NULL before writing a new value");
1963     _scanned_compiled_method = cm;
1964   }
1965 
1966   // Hide sweeper thread from external view.
1967   bool is_hidden_from_external_view() const { return true; }
1968 
1969   bool is_Code_cache_sweeper_thread() const { return true; }
1970 
1971   // Prevent GC from unloading _scanned_compiled_method
1972   void oops_do(OopClosure* f, CodeBlobClosure* cf);
1973   void nmethods_do(CodeBlobClosure* cf);
1974 };
1975 
1976 // A thread used for Compilation.
1977 class CompilerThread : public JavaThread {
1978   friend class VMStructs;
1979  private:
1980   CompilerCounters* _counters;
1981 
1982   ciEnv*            _env;
1983   CompileLog*       _log;
1984   CompileTask*      _task;
1985   CompileQueue*     _queue;
1986   BufferBlob*       _buffer_blob;
1987 
1988   AbstractCompiler* _compiler;
1989 
1990  public:
1991 
1992   static CompilerThread* current();
1993 
1994   CompilerThread(CompileQueue* queue, CompilerCounters* counters);
1995 
1996   bool is_Compiler_thread() const                { return true; }
1997 
1998   virtual bool can_call_java() const;
1999 
2000   // Hide native compiler threads from external view.
2001   bool is_hidden_from_external_view() const      { return !can_call_java(); }
2002 
2003   void set_compiler(AbstractCompiler* c)         { _compiler = c; }
2004   AbstractCompiler* compiler() const             { return _compiler; }
2005 
2006   CompileQueue* queue()        const             { return _queue; }
2007   CompilerCounters* counters() const             { return _counters; }
2008 
2009   // Get/set the thread's compilation environment.
2010   ciEnv*        env()                            { return _env; }
2011   void          set_env(ciEnv* env)              { _env = env; }
2012 
2013   BufferBlob*   get_buffer_blob() const          { return _buffer_blob; }
2014   void          set_buffer_blob(BufferBlob* b)   { _buffer_blob = b; }
2015 
2016   // Get/set the thread's logging information
2017   CompileLog*   log()                            { return _log; }
2018   void          init_log(CompileLog* log) {
2019     // Set once, for good.
2020     assert(_log == NULL, "set only once");
2021     _log = log;
2022   }
2023 
2024 #ifndef PRODUCT
2025  private:
2026   IdealGraphPrinter *_ideal_graph_printer;
2027  public:
2028   IdealGraphPrinter *ideal_graph_printer()           { return _ideal_graph_printer; }
2029   void set_ideal_graph_printer(IdealGraphPrinter *n) { _ideal_graph_printer = n; }
2030 #endif
2031 
2032   // Get/set the thread's current task
2033   CompileTask* task()                      { return _task; }
2034   void         set_task(CompileTask* task) { _task = task; }
2035 };
2036 
2037 inline CompilerThread* CompilerThread::current() {
2038   return JavaThread::current()->as_CompilerThread();
2039 }
2040 
2041 // The active thread queue. It also keeps track of the current used
2042 // thread priorities.
2043 class Threads: AllStatic {
2044   friend class VMStructs;
2045  private:
2046   static JavaThread* _thread_list;
2047   static int         _number_of_threads;
2048   static int         _number_of_non_daemon_threads;
2049   static int         _return_code;
2050   static int         _thread_claim_parity;
2051 #ifdef ASSERT
2052   static bool        _vm_complete;
2053 #endif
2054 
2055   static void initialize_java_lang_classes(JavaThread* main_thread, TRAPS);
2056   static void initialize_jsr292_core_classes(TRAPS);
2057  public:
2058   // Thread management
2059   // force_daemon is a concession to JNI, where we may need to add a
2060   // thread to the thread list before allocating its thread object
2061   static void add(JavaThread* p, bool force_daemon = false);
2062   static void remove(JavaThread* p);
2063   static bool includes(JavaThread* p);
2064   static JavaThread* first()                     { return _thread_list; }
2065   static void threads_do(ThreadClosure* tc);
2066 
2067   // Initializes the vm and creates the vm thread
2068   static jint create_vm(JavaVMInitArgs* args, bool* canTryAgain);
2069   static void convert_vm_init_libraries_to_agents();
2070   static void create_vm_init_libraries();
2071   static void create_vm_init_agents();
2072   static void shutdown_vm_agents();
2073   static bool destroy_vm();
2074   // Supported VM versions via JNI
2075   // Includes JNI_VERSION_1_1
2076   static jboolean is_supported_jni_version_including_1_1(jint version);
2077   // Does not include JNI_VERSION_1_1
2078   static jboolean is_supported_jni_version(jint version);
2079 
2080   // The "thread claim parity" provides a way for threads to be claimed
2081   // by parallel worker tasks.
2082   //
2083   // Each thread contains a a "parity" field. A task will claim the
2084   // thread only if its parity field is the same as the global parity,
2085   // which is updated by calling change_thread_claim_parity().
2086   //
2087   // For this to work change_thread_claim_parity() needs to be called
2088   // exactly once in sequential code before starting parallel tasks
2089   // that should claim threads.
2090   //
2091   // New threads get their parity set to 0 and change_thread_claim_parity()
2092   // never set the global parity to 0.
2093   static int thread_claim_parity() { return _thread_claim_parity; }
2094   static void change_thread_claim_parity();
2095   static void assert_all_threads_claimed() NOT_DEBUG_RETURN;
2096 
2097   // Apply "f->do_oop" to all root oops in all threads.
2098   // This version may only be called by sequential code.
2099   static void oops_do(OopClosure* f, CodeBlobClosure* cf);
2100   // This version may be called by sequential or parallel code.
2101   static void possibly_parallel_oops_do(bool is_par, OopClosure* f, CodeBlobClosure* cf);
2102   // This creates a list of GCTasks, one per thread.
2103   static void create_thread_roots_tasks(GCTaskQueue* q);
2104   // This creates a list of GCTasks, one per thread, for marking objects.
2105   static void create_thread_roots_marking_tasks(GCTaskQueue* q);
2106 
2107   // Apply "f->do_oop" to roots in all threads that
2108   // are part of compiled frames
2109   static void compiled_frame_oops_do(OopClosure* f, CodeBlobClosure* cf);
2110 
2111   static void convert_hcode_pointers();
2112   static void restore_hcode_pointers();
2113 
2114   // Sweeper
2115   static void nmethods_do(CodeBlobClosure* cf);
2116 
2117   // RedefineClasses support
2118   static void metadata_do(void f(Metadata*));
2119   static void metadata_handles_do(void f(Metadata*));
2120 
2121 #ifdef ASSERT
2122   static bool is_vm_complete() { return _vm_complete; }
2123 #endif
2124 
2125   // Verification
2126   static void verify();
2127   static void print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks);
2128   static void print(bool print_stacks, bool internal_format) {
2129     // this function is only used by debug.cpp
2130     print_on(tty, print_stacks, internal_format, false /* no concurrent lock printed */);
2131   }
2132   static void print_on_error(outputStream* st, Thread* current, char* buf, int buflen);
2133   static void print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
2134                              int buflen, bool* found_current);
2135   static void print_threads_compiling(outputStream* st, char* buf, int buflen);
2136 
2137   // Get Java threads that are waiting to enter a monitor. If doLock
2138   // is true, then Threads_lock is grabbed as needed. Otherwise, the
2139   // VM needs to be at a safepoint.
2140   static GrowableArray<JavaThread*>* get_pending_threads(int count,
2141                                                          address monitor, bool doLock);
2142 
2143   // Get owning Java thread from the monitor's owner field. If doLock
2144   // is true, then Threads_lock is grabbed as needed. Otherwise, the
2145   // VM needs to be at a safepoint.
2146   static JavaThread *owning_thread_from_monitor_owner(address owner,
2147                                                       bool doLock);
2148 
2149   // Number of threads on the active threads list
2150   static int number_of_threads()                 { return _number_of_threads; }
2151   // Number of non-daemon threads on the active threads list
2152   static int number_of_non_daemon_threads()      { return _number_of_non_daemon_threads; }
2153 
2154   // Deoptimizes all frames tied to marked nmethods
2155   static void deoptimized_wrt_marked_nmethods();
2156 
2157   static JavaThread* find_java_thread_from_java_tid(jlong java_tid);
2158 
2159 };
2160 
2161 
2162 // Thread iterator
2163 class ThreadClosure: public StackObj {
2164  public:
2165   virtual void do_thread(Thread* thread) = 0;
2166 };
2167 
2168 class SignalHandlerMark: public StackObj {
2169  private:
2170   Thread* _thread;
2171  public:
2172   SignalHandlerMark(Thread* t) {
2173     _thread = t;
2174     if (_thread) _thread->enter_signal_handler();
2175   }
2176   ~SignalHandlerMark() {
2177     if (_thread) _thread->leave_signal_handler();
2178     _thread = NULL;
2179   }
2180 };
2181 
2182 
2183 #endif // SHARE_VM_RUNTIME_THREAD_HPP