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