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 
 187   // suspend/resume lock: used for self-suspend
 188   Monitor* _SR_lock;
 189 
 190  protected:
 191   enum SuspendFlags {
 192     // NOTE: avoid using the sign-bit as cc generates different test code
 193     //       when the sign-bit is used, and sometimes incorrectly - see CR 6398077
 194 
 195     _external_suspend       = 0x20000000U, // thread is asked to self suspend
 196     _ext_suspended          = 0x40000000U, // thread has self-suspended
 197     _deopt_suspend          = 0x10000000U, // thread needs to self suspend for deopt
 198 
 199     _has_async_exception    = 0x00000001U, // there is a pending async exception
 200     _critical_native_unlock = 0x00000002U  // Must call back to unlock JNI critical lock
 201   };
 202 
 203   // various suspension related flags - atomically updated
 204   // overloaded for async exception checking in check_special_condition_for_native_trans.
 205   volatile uint32_t _suspend_flags;
 206 
 207  private:
 208   int _num_nested_signal;
 209 
 210  public:
 211   void enter_signal_handler() { _num_nested_signal++; }
 212   void leave_signal_handler() { _num_nested_signal--; }
 213   bool is_inside_signal_handler() const { return _num_nested_signal > 0; }
 214 
 215  private:
 216   // Debug tracing
 217   static void trace(const char* msg, const Thread* const thread) PRODUCT_RETURN;
 218 
 219   // Active_handles points to a block of handles
 220   JNIHandleBlock* _active_handles;
 221 
 222   // One-element thread local free list
 223   JNIHandleBlock* _free_handle_block;
 224 
 225   // Point to the last handle mark
 226   HandleMark* _last_handle_mark;
 227 
 228   // The parity of the last strong_roots iteration in which this thread was
 229   // claimed as a task.
 230   jint _oops_do_parity;
 231 
 232   public:
 233    void set_last_handle_mark(HandleMark* mark)   { _last_handle_mark = mark; }
 234    HandleMark* last_handle_mark() const          { return _last_handle_mark; }
 235   private:
 236 
 237   // debug support for checking if code does allow safepoints or not
 238   // GC points in the VM can happen because of allocation, invoking a VM operation, or blocking on
 239   // mutex, or blocking on an object synchronizer (Java locking).
 240   // If !allow_safepoint(), then an assertion failure will happen in any of the above cases
 241   // If !allow_allocation(), then an assertion failure will happen during allocation
 242   // (Hence, !allow_safepoint() => !allow_allocation()).
 243   //
 244   // The two classes No_Safepoint_Verifier and No_Allocation_Verifier are used to set these counters.
 245   //
 246   NOT_PRODUCT(int _allow_safepoint_count;)      // If 0, thread allow a safepoint to happen
 247   debug_only (int _allow_allocation_count;)     // If 0, the thread is allowed to allocate oops.
 248 
 249   // Used by SkipGCALot class.
 250   NOT_PRODUCT(bool _skip_gcalot;)               // Should we elide gc-a-lot?
 251 
 252   friend class No_Alloc_Verifier;
 253   friend class No_Safepoint_Verifier;
 254   friend class Pause_No_Safepoint_Verifier;
 255   friend class ThreadLocalStorage;
 256   friend class GC_locker;
 257 
 258   ThreadLocalAllocBuffer _tlab;                 // Thread-local eden
 259   jlong _allocated_bytes;                       // Cumulative number of bytes allocated on
 260                                                 // the Java heap
 261 
 262   // Thread-local buffer used by MetadataOnStackMark.
 263   MetadataOnStackBuffer* _metadata_on_stack_buffer;
 264 
 265   TRACE_DATA _trace_data;                       // Thread-local data for tracing
 266 
 267   ThreadExt _ext;
 268 
 269   int   _vm_operation_started_count;            // VM_Operation support
 270   int   _vm_operation_completed_count;          // VM_Operation support
 271 
 272   ObjectMonitor* _current_pending_monitor;      // ObjectMonitor this thread
 273                                                 // is waiting to lock
 274   bool _current_pending_monitor_is_from_java;   // locking is from Java code
 275 
 276   // ObjectMonitor on which this thread called Object.wait()
 277   ObjectMonitor* _current_waiting_monitor;
 278 
 279   // Private thread-local objectmonitor list - a simple cache organized as a SLL.
 280  public:
 281   ObjectMonitor* omFreeList;
 282   int omFreeCount;                              // length of omFreeList
 283   int omFreeProvision;                          // reload chunk size
 284   ObjectMonitor* omInUseList;                   // SLL to track monitors in circulation
 285   int omInUseCount;                             // length of omInUseList
 286 
 287 #ifdef ASSERT
 288  private:
 289   bool _visited_for_critical_count;
 290 
 291  public:
 292   void set_visited_for_critical_count(bool z) { _visited_for_critical_count = z; }
 293   bool was_visited_for_critical_count() const   { return _visited_for_critical_count; }
 294 #endif
 295 
 296  public:
 297   enum {
 298     is_definitely_current_thread = true
 299   };
 300 
 301   // Constructor
 302   Thread();
 303   virtual ~Thread();
 304 
 305   // initializtion
 306   void initialize_thread_local_storage();
 307 
 308   // thread entry point
 309   virtual void run();
 310 
 311   // Testers
 312   virtual bool is_VM_thread()       const            { return false; }
 313   virtual bool is_Java_thread()     const            { return false; }
 314   virtual bool is_Compiler_thread() const            { return false; }
 315   virtual bool is_hidden_from_external_view() const  { return false; }
 316   virtual bool is_jvmti_agent_thread() const         { return false; }
 317   // True iff the thread can perform GC operations at a safepoint.
 318   // Generally will be true only of VM thread and parallel GC WorkGang
 319   // threads.
 320   virtual bool is_GC_task_thread() const             { return false; }
 321   virtual bool is_Watcher_thread() const             { return false; }
 322   virtual bool is_ConcurrentGC_thread() const        { return false; }
 323   virtual bool is_Named_thread() const               { return false; }
 324   virtual bool is_Worker_thread() const              { return false; }
 325 
 326   // Casts
 327   virtual WorkerThread* as_Worker_thread() const     { return NULL; }
 328 
 329   virtual char* name() const { return (char*)"Unknown thread"; }
 330 
 331   // Returns the current thread
 332   static inline Thread* current();
 333 
 334   // Common thread operations
 335   static void set_priority(Thread* thread, ThreadPriority priority);
 336   static ThreadPriority get_priority(const Thread* const thread);
 337   static void start(Thread* thread);
 338   static void interrupt(Thread* thr);
 339   static bool is_interrupted(Thread* thr, bool clear_interrupted);
 340 
 341   void set_native_thread_name(const char *name) {
 342     assert(Thread::current() == this, "set_native_thread_name can only be called on the current thread");
 343     os::set_native_thread_name(name);
 344   }
 345 
 346   ObjectMonitor** omInUseList_addr()             { return (ObjectMonitor **)&omInUseList; }
 347   Monitor* SR_lock() const                       { return _SR_lock; }
 348 
 349   bool has_async_exception() const { return (_suspend_flags & _has_async_exception) != 0; }
 350 
 351   void set_suspend_flag(SuspendFlags f) {
 352     assert(sizeof(jint) == sizeof(_suspend_flags), "size mismatch");
 353     uint32_t flags;
 354     do {
 355       flags = _suspend_flags;
 356     }
 357     while (Atomic::cmpxchg((jint)(flags | f),
 358                            (volatile jint*)&_suspend_flags,
 359                            (jint)flags) != (jint)flags);
 360   }
 361   void clear_suspend_flag(SuspendFlags f) {
 362     assert(sizeof(jint) == sizeof(_suspend_flags), "size mismatch");
 363     uint32_t flags;
 364     do {
 365       flags = _suspend_flags;
 366     }
 367     while (Atomic::cmpxchg((jint)(flags & ~f),
 368                            (volatile jint*)&_suspend_flags,
 369                            (jint)flags) != (jint)flags);
 370   }
 371 
 372   void set_has_async_exception() {
 373     set_suspend_flag(_has_async_exception);
 374   }
 375   void clear_has_async_exception() {
 376     clear_suspend_flag(_has_async_exception);
 377   }
 378 
 379   bool do_critical_native_unlock() const { return (_suspend_flags & _critical_native_unlock) != 0; }
 380 
 381   void set_critical_native_unlock() {
 382     set_suspend_flag(_critical_native_unlock);
 383   }
 384   void clear_critical_native_unlock() {
 385     clear_suspend_flag(_critical_native_unlock);
 386   }
 387 
 388   // Support for Unhandled Oop detection
 389 #ifdef CHECK_UNHANDLED_OOPS
 390  private:
 391   UnhandledOops* _unhandled_oops;
 392  public:
 393   UnhandledOops* unhandled_oops() { return _unhandled_oops; }
 394   // Mark oop safe for gc.  It may be stack allocated but won't move.
 395   void allow_unhandled_oop(oop *op) {
 396     if (CheckUnhandledOops) unhandled_oops()->allow_unhandled_oop(op);
 397   }
 398   // Clear oops at safepoint so crashes point to unhandled oop violator
 399   void clear_unhandled_oops() {
 400     if (CheckUnhandledOops) unhandled_oops()->clear_unhandled_oops();
 401   }
 402 #endif // CHECK_UNHANDLED_OOPS
 403 
 404 #ifndef PRODUCT
 405   bool skip_gcalot()           { return _skip_gcalot; }
 406   void set_skip_gcalot(bool v) { _skip_gcalot = v;    }
 407 #endif
 408 
 409  public:
 410   // Installs a pending exception to be inserted later
 411   static void send_async_exception(oop thread_oop, oop java_throwable);
 412 
 413   // Resource area
 414   ResourceArea* resource_area() const            { return _resource_area; }
 415   void set_resource_area(ResourceArea* area)     { _resource_area = area; }
 416 
 417   OSThread* osthread() const                     { return _osthread;   }
 418   void set_osthread(OSThread* thread)            { _osthread = thread; }
 419 
 420   // JNI handle support
 421   JNIHandleBlock* active_handles() const         { return _active_handles; }
 422   void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
 423   JNIHandleBlock* free_handle_block() const      { return _free_handle_block; }
 424   void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
 425 
 426   // Internal handle support
 427   HandleArea* handle_area() const                { return _handle_area; }
 428   void set_handle_area(HandleArea* area)         { _handle_area = area; }
 429 
 430   GrowableArray<Metadata*>* metadata_handles() const          { return _metadata_handles; }
 431   void set_metadata_handles(GrowableArray<Metadata*>* handles){ _metadata_handles = handles; }
 432 
 433   // Thread-Local Allocation Buffer (TLAB) support
 434   ThreadLocalAllocBuffer& tlab()                 { return _tlab; }
 435   void initialize_tlab() {
 436     if (UseTLAB) {
 437       tlab().initialize();
 438     }
 439   }
 440 
 441   jlong allocated_bytes()               { return _allocated_bytes; }
 442   void set_allocated_bytes(jlong value) { _allocated_bytes = value; }
 443   void incr_allocated_bytes(jlong size) { _allocated_bytes += size; }
 444   inline jlong cooked_allocated_bytes();
 445 
 446   TRACE_DATA* trace_data()              { return &_trace_data; }
 447 
 448   const ThreadExt& ext() const          { return _ext; }
 449   ThreadExt& ext()                      { return _ext; }
 450 
 451   // VM operation support
 452   int vm_operation_ticket()                      { return ++_vm_operation_started_count; }
 453   int vm_operation_completed_count()             { return _vm_operation_completed_count; }
 454   void increment_vm_operation_completed_count()  { _vm_operation_completed_count++; }
 455 
 456   // For tracking the heavyweight monitor the thread is pending on.
 457   ObjectMonitor* current_pending_monitor() {
 458     return _current_pending_monitor;
 459   }
 460   void set_current_pending_monitor(ObjectMonitor* monitor) {
 461     _current_pending_monitor = monitor;
 462   }
 463   void set_current_pending_monitor_is_from_java(bool from_java) {
 464     _current_pending_monitor_is_from_java = from_java;
 465   }
 466   bool current_pending_monitor_is_from_java() {
 467     return _current_pending_monitor_is_from_java;
 468   }
 469 
 470   // For tracking the ObjectMonitor on which this thread called Object.wait()
 471   ObjectMonitor* current_waiting_monitor() {
 472     return _current_waiting_monitor;
 473   }
 474   void set_current_waiting_monitor(ObjectMonitor* monitor) {
 475     _current_waiting_monitor = monitor;
 476   }
 477 
 478   // GC support
 479   // Apply "f->do_oop" to all root oops in "this".
 480   // Apply "cld_f->do_cld" to CLDs that are otherwise not kept alive.
 481   //   Used by JavaThread::oops_do.
 482   // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames
 483   virtual void oops_do(OopClosure* f, CLDClosure* cld_f, CodeBlobClosure* cf);
 484 
 485   // Handles the parallel case for the method below.
 486 private:
 487   bool claim_oops_do_par_case(int collection_parity);
 488 public:
 489   // Requires that "collection_parity" is that of the current roots
 490   // iteration.  If "is_par" is false, sets the parity of "this" to
 491   // "collection_parity", and returns "true".  If "is_par" is true,
 492   // uses an atomic instruction to set the current threads parity to
 493   // "collection_parity", if it is not already.  Returns "true" iff the
 494   // calling thread does the update, this indicates that the calling thread
 495   // has claimed the thread's stack as a root groop in the current
 496   // collection.
 497   bool claim_oops_do(bool is_par, int collection_parity) {
 498     if (!is_par) {
 499       _oops_do_parity = collection_parity;
 500       return true;
 501     } else {
 502       return claim_oops_do_par_case(collection_parity);
 503     }
 504   }
 505 
 506   // Sweeper support
 507   void nmethods_do(CodeBlobClosure* cf);
 508 
 509   // jvmtiRedefineClasses support
 510   void metadata_do(void f(Metadata*));
 511 
 512   // Used by fast lock support
 513   virtual bool is_lock_owned(address adr) const;
 514 
 515   // Check if address is in the stack of the thread (not just for locks).
 516   // Warning: the method can only be used on the running thread
 517   bool is_in_stack(address adr) const;
 518   // Check if address is in the usable part of the stack (excludes protected
 519   // guard pages)
 520   bool is_in_usable_stack(address adr) const;
 521 
 522   // Sets this thread as starting thread. Returns failure if thread
 523   // creation fails due to lack of memory, too many threads etc.
 524   bool set_as_starting_thread();
 525 
 526   void set_metadata_on_stack_buffer(MetadataOnStackBuffer* buffer) { _metadata_on_stack_buffer = buffer; }
 527   MetadataOnStackBuffer* metadata_on_stack_buffer() const          { return _metadata_on_stack_buffer; }
 528 
 529 protected:
 530   // OS data associated with the thread
 531   OSThread* _osthread;  // Platform-specific thread information
 532 
 533   // Thread local resource area for temporary allocation within the VM
 534   ResourceArea* _resource_area;
 535 
 536   DEBUG_ONLY(ResourceMark* _current_resource_mark;)
 537 
 538   // Thread local handle area for allocation of handles within the VM
 539   HandleArea* _handle_area;
 540   GrowableArray<Metadata*>* _metadata_handles;
 541 
 542   // Support for stack overflow handling, get_thread, etc.
 543   address          _stack_base;
 544   size_t           _stack_size;
 545   uintptr_t        _self_raw_id;      // used by get_thread (mutable)
 546   int              _lgrp_id;
 547 
 548  public:
 549   // Stack overflow support
 550   address stack_base() const           { assert(_stack_base != NULL,"Sanity check"); return _stack_base; }
 551 
 552   void    set_stack_base(address base) { _stack_base = base; }
 553   size_t  stack_size() const           { return _stack_size; }
 554   void    set_stack_size(size_t size)  { _stack_size = size; }
 555   void    record_stack_base_and_size();
 556 
 557   bool    on_local_stack(address adr) const {
 558     /* QQQ this has knowledge of direction, ought to be a stack method */
 559     return (_stack_base >= adr && adr >= (_stack_base - _stack_size));
 560   }
 561 
 562   uintptr_t self_raw_id()                    { return _self_raw_id; }
 563   void      set_self_raw_id(uintptr_t value) { _self_raw_id = value; }
 564 
 565   int     lgrp_id() const        { return _lgrp_id; }
 566   void    set_lgrp_id(int value) { _lgrp_id = value; }
 567 
 568   // Printing
 569   void print_on(outputStream* st) const;
 570   void print() const { print_on(tty); }
 571   virtual void print_on_error(outputStream* st, char* buf, int buflen) const;
 572 
 573   // Debug-only code
 574 #ifdef ASSERT
 575  private:
 576   // Deadlock detection support for Mutex locks. List of locks own by thread.
 577   Monitor* _owned_locks;
 578   // Mutex::set_owner_implementation is the only place where _owned_locks is modified,
 579   // thus the friendship
 580   friend class Mutex;
 581   friend class Monitor;
 582 
 583  public:
 584   void print_owned_locks_on(outputStream* st) const;
 585   void print_owned_locks() const                 { print_owned_locks_on(tty);    }
 586   Monitor* owned_locks() const                   { return _owned_locks;          }
 587   bool owns_locks() const                        { return owned_locks() != NULL; }
 588   bool owns_locks_but_compiled_lock() const;
 589 
 590   // Deadlock detection
 591   bool allow_allocation()                        { return _allow_allocation_count == 0; }
 592   ResourceMark* current_resource_mark()          { return _current_resource_mark; }
 593   void set_current_resource_mark(ResourceMark* rm) { _current_resource_mark = rm; }
 594 #endif
 595 
 596   void check_for_valid_safepoint_state(bool potential_vm_operation) PRODUCT_RETURN;
 597 
 598  private:
 599   volatile int _jvmti_env_iteration_count;
 600 
 601  public:
 602   void entering_jvmti_env_iteration()            { ++_jvmti_env_iteration_count; }
 603   void leaving_jvmti_env_iteration()             { --_jvmti_env_iteration_count; }
 604   bool is_inside_jvmti_env_iteration()           { return _jvmti_env_iteration_count > 0; }
 605 
 606   // Code generation
 607   static ByteSize exception_file_offset()        { return byte_offset_of(Thread, _exception_file   ); }
 608   static ByteSize exception_line_offset()        { return byte_offset_of(Thread, _exception_line   ); }
 609   static ByteSize active_handles_offset()        { return byte_offset_of(Thread, _active_handles   ); }
 610 
 611   static ByteSize stack_base_offset()            { return byte_offset_of(Thread, _stack_base ); }
 612   static ByteSize stack_size_offset()            { return byte_offset_of(Thread, _stack_size ); }
 613 
 614 #define TLAB_FIELD_OFFSET(name) \
 615   static ByteSize tlab_##name##_offset()         { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::name##_offset(); }
 616 
 617   TLAB_FIELD_OFFSET(start)
 618   TLAB_FIELD_OFFSET(end)
 619   TLAB_FIELD_OFFSET(top)
 620   TLAB_FIELD_OFFSET(pf_top)
 621   TLAB_FIELD_OFFSET(size)                   // desired_size
 622   TLAB_FIELD_OFFSET(refill_waste_limit)
 623   TLAB_FIELD_OFFSET(number_of_refills)
 624   TLAB_FIELD_OFFSET(fast_refill_waste)
 625   TLAB_FIELD_OFFSET(slow_allocations)
 626 
 627 #undef TLAB_FIELD_OFFSET
 628 
 629   static ByteSize allocated_bytes_offset()       { return byte_offset_of(Thread, _allocated_bytes ); }
 630 
 631  public:
 632   volatile intptr_t _Stalled ;
 633   volatile int _TypeTag ;
 634   ParkEvent * _ParkEvent ;                     // for synchronized()
 635   ParkEvent * _SleepEvent ;                    // for Thread.sleep
 636   ParkEvent * _MutexEvent ;                    // for native internal Mutex/Monitor
 637   ParkEvent * _MuxEvent ;                      // for low-level muxAcquire-muxRelease
 638   int NativeSyncRecursion ;                    // diagnostic
 639 
 640   volatile int _OnTrap ;                       // Resume-at IP delta
 641   jint _hashStateW ;                           // Marsaglia Shift-XOR thread-local RNG
 642   jint _hashStateX ;                           // thread-specific hashCode generator state
 643   jint _hashStateY ;
 644   jint _hashStateZ ;
 645   void * _schedctl ;
 646 
 647 
 648   volatile jint rng [4] ;                      // RNG for spin loop
 649 
 650   // Low-level leaf-lock primitives used to implement synchronization
 651   // and native monitor-mutex infrastructure.
 652   // Not for general synchronization use.
 653   static void SpinAcquire (volatile int * Lock, const char * Name) ;
 654   static void SpinRelease (volatile int * Lock) ;
 655   static void muxAcquire  (volatile intptr_t * Lock, const char * Name) ;
 656   static void muxAcquireW (volatile intptr_t * Lock, ParkEvent * ev) ;
 657   static void muxRelease  (volatile intptr_t * Lock) ;
 658 };
 659 
 660 // Inline implementation of Thread::current()
 661 // Thread::current is "hot" it's called > 128K times in the 1st 500 msecs of
 662 // startup.
 663 // ThreadLocalStorage::thread is warm -- it's called > 16K times in the same
 664 // period.   This is inlined in thread_<os_family>.inline.hpp.
 665 
 666 inline Thread* Thread::current() {
 667 #ifdef ASSERT
 668 // This function is very high traffic. Define PARANOID to enable expensive
 669 // asserts.
 670 #ifdef PARANOID
 671   // Signal handler should call ThreadLocalStorage::get_thread_slow()
 672   Thread* t = ThreadLocalStorage::get_thread_slow();
 673   assert(t != NULL && !t->is_inside_signal_handler(),
 674          "Don't use Thread::current() inside signal handler");
 675 #endif
 676 #endif
 677   Thread* thread = ThreadLocalStorage::thread();
 678   assert(thread != NULL, "just checking");
 679   return thread;
 680 }
 681 
 682 // Name support for threads.  non-JavaThread subclasses with multiple
 683 // uniquely named instances should derive from this.
 684 class NamedThread: public Thread {
 685   friend class VMStructs;
 686   enum {
 687     max_name_len = 64
 688   };
 689  private:
 690   char* _name;
 691   // log JavaThread being processed by oops_do
 692   JavaThread* _processed_thread;
 693 
 694  public:
 695   NamedThread();
 696   ~NamedThread();
 697   // May only be called once per thread.
 698   void set_name(const char* format, ...)  ATTRIBUTE_PRINTF(2, 3);
 699   virtual bool is_Named_thread() const { return true; }
 700   virtual char* name() const { return _name == NULL ? (char*)"Unknown Thread" : _name; }
 701   JavaThread *processed_thread() { return _processed_thread; }
 702   void set_processed_thread(JavaThread *thread) { _processed_thread = thread; }
 703 };
 704 
 705 // Worker threads are named and have an id of an assigned work.
 706 class WorkerThread: public NamedThread {
 707 private:
 708   uint _id;
 709 public:
 710   WorkerThread() : _id(0)               { }
 711   virtual bool is_Worker_thread() const { return true; }
 712 
 713   virtual WorkerThread* as_Worker_thread() const {
 714     assert(is_Worker_thread(), "Dubious cast to WorkerThread*?");
 715     return (WorkerThread*) this;
 716   }
 717 
 718   void set_id(uint work_id)             { _id = work_id; }
 719   uint id() const                       { return _id; }
 720 };
 721 
 722 // A single WatcherThread is used for simulating timer interrupts.
 723 class WatcherThread: public Thread {
 724   friend class VMStructs;
 725  public:
 726   virtual void run();
 727 
 728  private:
 729   static WatcherThread* _watcher_thread;
 730 
 731   static bool _startable;
 732   volatile static bool _should_terminate; // updated without holding lock
 733 
 734   os::WatcherThreadCrashProtection* _crash_protection;
 735  public:
 736   enum SomeConstants {
 737     delay_interval = 10                          // interrupt delay in milliseconds
 738   };
 739 
 740   // Constructor
 741   WatcherThread();
 742 
 743   // Tester
 744   bool is_Watcher_thread() const                 { return true; }
 745 
 746   // Printing
 747   char* name() const { return (char*)"VM Periodic Task Thread"; }
 748   void print_on(outputStream* st) const;
 749   void print() const { print_on(tty); }
 750   void unpark();
 751 
 752   // Returns the single instance of WatcherThread
 753   static WatcherThread* watcher_thread()         { return _watcher_thread; }
 754 
 755   // Create and start the single instance of WatcherThread, or stop it on shutdown
 756   static void start();
 757   static void stop();
 758   // Only allow start once the VM is sufficiently initialized
 759   // Otherwise the first task to enroll will trigger the start
 760   static void make_startable();
 761 
 762   void set_crash_protection(os::WatcherThreadCrashProtection* crash_protection) {
 763     assert(Thread::current()->is_Watcher_thread(), "Can only be set by WatcherThread");
 764     _crash_protection = crash_protection;
 765   }
 766 
 767   bool has_crash_protection() const { return _crash_protection != NULL; }
 768   os::WatcherThreadCrashProtection* crash_protection() const { return _crash_protection; }
 769 
 770  private:
 771   int sleep() const;
 772 };
 773 
 774 
 775 class CompilerThread;
 776 
 777 typedef void (*ThreadFunction)(JavaThread*, TRAPS);
 778 
 779 class JavaThread: public Thread {
 780   friend class VMStructs;
 781  private:
 782   JavaThread*    _next;                          // The next thread in the Threads list
 783   oop            _threadObj;                     // The Java level thread object
 784 
 785 #ifdef ASSERT
 786  private:
 787   int _java_call_counter;
 788 
 789  public:
 790   int  java_call_counter()                       { return _java_call_counter; }
 791   void inc_java_call_counter()                   { _java_call_counter++; }
 792   void dec_java_call_counter() {
 793     assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
 794     _java_call_counter--;
 795   }
 796  private:  // restore original namespace restriction
 797 #endif  // ifdef ASSERT
 798 
 799 #ifndef PRODUCT
 800  public:
 801   enum {
 802     jump_ring_buffer_size = 16
 803   };
 804  private:  // restore original namespace restriction
 805 #endif
 806 
 807   JavaFrameAnchor _anchor;                       // Encapsulation of current java frame and it state
 808 
 809   ThreadFunction _entry_point;
 810 
 811   JNIEnv        _jni_environment;
 812 
 813   // Deopt support
 814   DeoptResourceMark*  _deopt_mark;               // Holds special ResourceMark for deoptimization
 815 
 816   intptr_t*      _must_deopt_id;                 // id of frame that needs to be deopted once we
 817                                                  // transition out of native
 818   nmethod*       _deopt_nmethod;                 // nmethod that is currently being deoptimized
 819   vframeArray*  _vframe_array_head;              // Holds the heap of the active vframeArrays
 820   vframeArray*  _vframe_array_last;              // Holds last vFrameArray we popped
 821   // Because deoptimization is lazy we must save jvmti requests to set locals
 822   // in compiled frames until we deoptimize and we have an interpreter frame.
 823   // This holds the pointer to array (yeah like there might be more than one) of
 824   // description of compiled vframes that have locals that need to be updated.
 825   GrowableArray<jvmtiDeferredLocalVariableSet*>* _deferred_locals_updates;
 826 
 827   // Handshake value for fixing 6243940. We need a place for the i2c
 828   // adapter to store the callee Method*. This value is NEVER live
 829   // across a gc point so it does NOT have to be gc'd
 830   // The handshake is open ended since we can't be certain that it will
 831   // be NULLed. This is because we rarely ever see the race and end up
 832   // in handle_wrong_method which is the backend of the handshake. See
 833   // code in i2c adapters and handle_wrong_method.
 834 
 835   Method*       _callee_target;
 836 
 837   // Used to pass back results to the interpreter or generated code running Java code.
 838   oop           _vm_result;    // oop result is GC-preserved
 839   Metadata*     _vm_result_2;  // non-oop result
 840 
 841   // See ReduceInitialCardMarks: this holds the precise space interval of
 842   // the most recent slow path allocation for which compiled code has
 843   // elided card-marks for performance along the fast-path.
 844   MemRegion     _deferred_card_mark;
 845 
 846   MonitorChunk* _monitor_chunks;                 // Contains the off stack monitors
 847                                                  // allocated during deoptimization
 848                                                  // and by JNI_MonitorEnter/Exit
 849 
 850   // Async. requests support
 851   enum AsyncRequests {
 852     _no_async_condition = 0,
 853     _async_exception,
 854     _async_unsafe_access_error
 855   };
 856   AsyncRequests _special_runtime_exit_condition; // Enum indicating pending async. request
 857   oop           _pending_async_exception;
 858 
 859   // Safepoint support
 860  public:                                         // Expose _thread_state for SafeFetchInt()
 861   volatile JavaThreadState _thread_state;
 862  private:
 863   ThreadSafepointState *_safepoint_state;        // Holds information about a thread during a safepoint
 864   address               _saved_exception_pc;     // Saved pc of instruction where last implicit exception happened
 865 
 866   // JavaThread termination support
 867   enum TerminatedTypes {
 868     _not_terminated = 0xDEAD - 2,
 869     _thread_exiting,                             // JavaThread::exit() has been called for this thread
 870     _thread_terminated,                          // JavaThread is removed from thread list
 871     _vm_exited                                   // JavaThread is still executing native code, but VM is terminated
 872                                                  // only VM_Exit can set _vm_exited
 873   };
 874 
 875   // In general a JavaThread's _terminated field transitions as follows:
 876   //
 877   //   _not_terminated => _thread_exiting => _thread_terminated
 878   //
 879   // _vm_exited is a special value to cover the case of a JavaThread
 880   // executing native code after the VM itself is terminated.
 881   volatile TerminatedTypes _terminated;
 882   // suspend/resume support
 883   volatile bool         _suspend_equivalent;     // Suspend equivalent condition
 884   jint                  _in_deopt_handler;       // count of deoptimization
 885                                                  // handlers thread is in
 886   volatile bool         _doing_unsafe_access;    // Thread may fault due to unsafe access
 887   bool                  _do_not_unlock_if_synchronized; // Do not unlock the receiver of a synchronized method (since it was
 888                                                  // never locked) when throwing an exception. Used by interpreter only.
 889 
 890   // JNI attach states:
 891   enum JNIAttachStates {
 892     _not_attaching_via_jni = 1,  // thread is not attaching via JNI
 893     _attaching_via_jni,          // thread is attaching via JNI
 894     _attached_via_jni            // thread has attached via JNI
 895   };
 896 
 897   // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
 898   // A native thread that is attaching via JNI starts with a value
 899   // of _attaching_via_jni and transitions to _attached_via_jni.
 900   volatile JNIAttachStates _jni_attach_state;
 901 
 902  public:
 903   // State of the stack guard pages for this thread.
 904   enum StackGuardState {
 905     stack_guard_unused,         // not needed
 906     stack_guard_yellow_disabled,// disabled (temporarily) after stack overflow
 907     stack_guard_enabled         // enabled
 908   };
 909 
 910  private:
 911 
 912   StackGuardState  _stack_guard_state;
 913 
 914   // Precompute the limit of the stack as used in stack overflow checks.
 915   // We load it from here to simplify the stack overflow check in assembly.
 916   address          _stack_overflow_limit;
 917 
 918   // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
 919   // used to temp. parsing values into and out of the runtime system during exception handling for compiled
 920   // code)
 921   volatile oop     _exception_oop;               // Exception thrown in compiled code
 922   volatile address _exception_pc;                // PC where exception happened
 923   volatile address _exception_handler_pc;        // PC for handler of exception
 924   volatile int     _is_method_handle_return;     // true (== 1) if the current exception PC is a MethodHandle call site.
 925 
 926   // support for JNI critical regions
 927   jint    _jni_active_critical;                  // count of entries into JNI critical region
 928 
 929   // Checked JNI: function name requires exception check
 930   char* _pending_jni_exception_check_fn;
 931 
 932   // For deadlock detection.
 933   int _depth_first_number;
 934 
 935   // JVMTI PopFrame support
 936   // This is set to popframe_pending to signal that top Java frame should be popped immediately
 937   int _popframe_condition;
 938 
 939   // If reallocation of scalar replaced objects fails, we throw OOM
 940   // and during exception propagation, pop the top
 941   // _frames_to_pop_failed_realloc frames, the ones that reference
 942   // failed reallocations.
 943   int _frames_to_pop_failed_realloc;
 944 
 945 #ifndef PRODUCT
 946   int _jmp_ring_index;
 947   struct {
 948       // We use intptr_t instead of address so debugger doesn't try and display strings
 949       intptr_t _target;
 950       intptr_t _instruction;
 951       const char*  _file;
 952       int _line;
 953   }   _jmp_ring[ jump_ring_buffer_size ];
 954 #endif /* PRODUCT */
 955 
 956 #if INCLUDE_ALL_GCS
 957   // Support for G1 barriers
 958 
 959   ObjPtrQueue _satb_mark_queue;          // Thread-local log for SATB barrier.
 960   // Set of all such queues.
 961   static SATBMarkQueueSet _satb_mark_queue_set;
 962 
 963   DirtyCardQueue _dirty_card_queue;      // Thread-local log for dirty cards.
 964   // Set of all such queues.
 965   static DirtyCardQueueSet _dirty_card_queue_set;
 966 
 967   void flush_barrier_queues();
 968 #endif // INCLUDE_ALL_GCS
 969 
 970   friend class VMThread;
 971   friend class ThreadWaitTransition;
 972   friend class VM_Exit;
 973 
 974   void initialize();                             // Initialized the instance variables
 975 
 976  public:
 977   // Constructor
 978   JavaThread(bool is_attaching_via_jni = false); // for main thread and JNI attached threads
 979   JavaThread(ThreadFunction entry_point, size_t stack_size = 0);
 980   ~JavaThread();
 981 
 982 #ifdef ASSERT
 983   // verify this JavaThread hasn't be published in the Threads::list yet
 984   void verify_not_published();
 985 #endif
 986 
 987   //JNI functiontable getter/setter for JVMTI jni function table interception API.
 988   void set_jni_functions(struct JNINativeInterface_* functionTable) {
 989     _jni_environment.functions = functionTable;
 990   }
 991   struct JNINativeInterface_* get_jni_functions() {
 992     return (struct JNINativeInterface_ *)_jni_environment.functions;
 993   }
 994 
 995   // This function is called at thread creation to allow
 996   // platform specific thread variables to be initialized.
 997   void cache_global_variables();
 998 
 999   // Executes Shutdown.shutdown()
1000   void invoke_shutdown_hooks();
1001 
1002   // Cleanup on thread exit
1003   enum ExitType {
1004     normal_exit,
1005     jni_detach
1006   };
1007   void exit(bool destroy_vm, ExitType exit_type = normal_exit);
1008 
1009   void cleanup_failed_attach_current_thread();
1010 
1011   // Testers
1012   virtual bool is_Java_thread() const            { return true;  }
1013 
1014   // Thread chain operations
1015   JavaThread* next() const                       { return _next; }
1016   void set_next(JavaThread* p)                   { _next = p; }
1017 
1018   // Thread oop. threadObj() can be NULL for initial JavaThread
1019   // (or for threads attached via JNI)
1020   oop threadObj() const                          { return _threadObj; }
1021   void set_threadObj(oop p)                      { _threadObj = p; }
1022 
1023   ThreadPriority java_priority() const;          // Read from threadObj()
1024 
1025   // Prepare thread and add to priority queue.  If a priority is
1026   // not specified, use the priority of the thread object. Threads_lock
1027   // must be held while this function is called.
1028   void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
1029   void prepare_ext();
1030 
1031   void set_saved_exception_pc(address pc)        { _saved_exception_pc = pc; }
1032   address saved_exception_pc()                   { return _saved_exception_pc; }
1033 
1034 
1035   ThreadFunction entry_point() const             { return _entry_point; }
1036 
1037   // Allocates a new Java level thread object for this thread. thread_name may be NULL.
1038   void allocate_threadObj(Handle thread_group, char* thread_name, bool daemon, TRAPS);
1039 
1040   // Last frame anchor routines
1041 
1042   JavaFrameAnchor* frame_anchor(void)            { return &_anchor; }
1043 
1044   // last_Java_sp
1045   bool has_last_Java_frame() const               { return _anchor.has_last_Java_frame(); }
1046   intptr_t* last_Java_sp() const                 { return _anchor.last_Java_sp(); }
1047 
1048   // last_Java_pc
1049 
1050   address last_Java_pc(void)                     { return _anchor.last_Java_pc(); }
1051 
1052   // Safepoint support
1053 #ifndef PPC64
1054   JavaThreadState thread_state() const           { return _thread_state; }
1055   void set_thread_state(JavaThreadState s)       { _thread_state = s;    }
1056 #else
1057   // Use membars when accessing volatile _thread_state. See
1058   // Threads::create_vm() for size checks.
1059   inline JavaThreadState thread_state() const;
1060   inline void set_thread_state(JavaThreadState s);
1061 #endif
1062   ThreadSafepointState *safepoint_state() const  { return _safepoint_state; }
1063   void set_safepoint_state(ThreadSafepointState *state) { _safepoint_state = state; }
1064   bool is_at_poll_safepoint()                    { return _safepoint_state->is_at_poll_safepoint(); }
1065 
1066   // thread has called JavaThread::exit() or is terminated
1067   bool is_exiting()                              { return _terminated == _thread_exiting || is_terminated(); }
1068   // thread is terminated (no longer on the threads list); we compare
1069   // against the two non-terminated values so that a freed JavaThread
1070   // will also be considered terminated.
1071   bool is_terminated()                           { return _terminated != _not_terminated && _terminated != _thread_exiting; }
1072   void set_terminated(TerminatedTypes t)         { _terminated = t; }
1073   // special for Threads::remove() which is static:
1074   void set_terminated_value()                    { _terminated = _thread_terminated; }
1075   void block_if_vm_exited();
1076 
1077   bool doing_unsafe_access()                     { return _doing_unsafe_access; }
1078   void set_doing_unsafe_access(bool val)         { _doing_unsafe_access = val; }
1079 
1080   bool do_not_unlock_if_synchronized()             { return _do_not_unlock_if_synchronized; }
1081   void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
1082 
1083   // Suspend/resume support for JavaThread
1084  private:
1085   void set_ext_suspended()       { set_suspend_flag (_ext_suspended);  }
1086   void clear_ext_suspended()     { clear_suspend_flag(_ext_suspended); }
1087 
1088  public:
1089   void java_suspend();
1090   void java_resume();
1091   int  java_suspend_self();
1092 
1093   void check_and_wait_while_suspended() {
1094     assert(JavaThread::current() == this, "sanity check");
1095 
1096     bool do_self_suspend;
1097     do {
1098       // were we externally suspended while we were waiting?
1099       do_self_suspend = handle_special_suspend_equivalent_condition();
1100       if (do_self_suspend) {
1101         // don't surprise the thread that suspended us by returning
1102         java_suspend_self();
1103         set_suspend_equivalent();
1104       }
1105     } while (do_self_suspend);
1106   }
1107   static void check_safepoint_and_suspend_for_native_trans(JavaThread *thread);
1108   // Check for async exception in addition to safepoint and suspend request.
1109   static void check_special_condition_for_native_trans(JavaThread *thread);
1110 
1111   // Same as check_special_condition_for_native_trans but finishes the
1112   // transition into thread_in_Java mode so that it can potentially
1113   // block.
1114   static void check_special_condition_for_native_trans_and_transition(JavaThread *thread);
1115 
1116   bool is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits);
1117   bool is_ext_suspend_completed_with_lock(uint32_t *bits) {
1118     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1119     // Warning: is_ext_suspend_completed() may temporarily drop the
1120     // SR_lock to allow the thread to reach a stable thread state if
1121     // it is currently in a transient thread state.
1122     return is_ext_suspend_completed(false /*!called_by_wait */,
1123                                     SuspendRetryDelay, bits);
1124   }
1125 
1126   // We cannot allow wait_for_ext_suspend_completion() to run forever or
1127   // we could hang. SuspendRetryCount and SuspendRetryDelay are normally
1128   // passed as the count and delay parameters. Experiments with specific
1129   // calls to wait_for_ext_suspend_completion() can be done by passing
1130   // other values in the code. Experiments with all calls can be done
1131   // via the appropriate -XX options.
1132   bool wait_for_ext_suspend_completion(int count, int delay, uint32_t *bits);
1133 
1134   void set_external_suspend()     { set_suspend_flag  (_external_suspend); }
1135   void clear_external_suspend()   { clear_suspend_flag(_external_suspend); }
1136 
1137   void set_deopt_suspend()        { set_suspend_flag  (_deopt_suspend); }
1138   void clear_deopt_suspend()      { clear_suspend_flag(_deopt_suspend); }
1139   bool is_deopt_suspend()         { return (_suspend_flags & _deopt_suspend) != 0; }
1140 
1141   bool is_external_suspend() const {
1142     return (_suspend_flags & _external_suspend) != 0;
1143   }
1144   // Whenever a thread transitions from native to vm/java it must suspend
1145   // if external|deopt suspend is present.
1146   bool is_suspend_after_native() const {
1147     return (_suspend_flags & (_external_suspend | _deopt_suspend) ) != 0;
1148   }
1149 
1150   // external suspend request is completed
1151   bool is_ext_suspended() const {
1152     return (_suspend_flags & _ext_suspended) != 0;
1153   }
1154 
1155   bool is_external_suspend_with_lock() const {
1156     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1157     return is_external_suspend();
1158   }
1159 
1160   // Special method to handle a pending external suspend request
1161   // when a suspend equivalent condition lifts.
1162   bool handle_special_suspend_equivalent_condition() {
1163     assert(is_suspend_equivalent(),
1164       "should only be called in a suspend equivalence condition");
1165     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1166     bool ret = is_external_suspend();
1167     if (!ret) {
1168       // not about to self-suspend so clear suspend equivalence
1169       clear_suspend_equivalent();
1170     }
1171     // implied else:
1172     // We have a pending external suspend request so we leave the
1173     // suspend_equivalent flag set until java_suspend_self() sets
1174     // the ext_suspended flag and clears the suspend_equivalent
1175     // flag. This insures that wait_for_ext_suspend_completion()
1176     // will return consistent values.
1177     return ret;
1178   }
1179 
1180   // utility methods to see if we are doing some kind of suspension
1181   bool is_being_ext_suspended() const            {
1182     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1183     return is_ext_suspended() || is_external_suspend();
1184   }
1185 
1186   bool is_suspend_equivalent() const             { return _suspend_equivalent; }
1187 
1188   void set_suspend_equivalent()                  { _suspend_equivalent = true; };
1189   void clear_suspend_equivalent()                { _suspend_equivalent = false; };
1190 
1191   // Thread.stop support
1192   void send_thread_stop(oop throwable);
1193   AsyncRequests clear_special_runtime_exit_condition() {
1194     AsyncRequests x = _special_runtime_exit_condition;
1195     _special_runtime_exit_condition = _no_async_condition;
1196     return x;
1197   }
1198 
1199   // Are any async conditions present?
1200   bool has_async_condition() { return (_special_runtime_exit_condition != _no_async_condition); }
1201 
1202   void check_and_handle_async_exceptions(bool check_unsafe_error = true);
1203 
1204   // these next two are also used for self-suspension and async exception support
1205   void handle_special_runtime_exit_condition(bool check_asyncs = true);
1206 
1207   // Return true if JavaThread has an asynchronous condition or
1208   // if external suspension is requested.
1209   bool has_special_runtime_exit_condition() {
1210     // We call is_external_suspend() last since external suspend should
1211     // be less common. Because we don't use is_external_suspend_with_lock
1212     // it is possible that we won't see an asynchronous external suspend
1213     // request that has just gotten started, i.e., SR_lock grabbed but
1214     // _external_suspend field change either not made yet or not visible
1215     // yet. However, this is okay because the request is asynchronous and
1216     // we will see the new flag value the next time through. It's also
1217     // possible that the external suspend request is dropped after
1218     // we have checked is_external_suspend(), we will recheck its value
1219     // under SR_lock in java_suspend_self().
1220     return (_special_runtime_exit_condition != _no_async_condition) ||
1221             is_external_suspend() || is_deopt_suspend();
1222   }
1223 
1224   void set_pending_unsafe_access_error()          { _special_runtime_exit_condition = _async_unsafe_access_error; }
1225 
1226   void set_pending_async_exception(oop e) {
1227     _pending_async_exception = e;
1228     _special_runtime_exit_condition = _async_exception;
1229     set_has_async_exception();
1230   }
1231 
1232   // Fast-locking support
1233   bool is_lock_owned(address adr) const;
1234 
1235   // Accessors for vframe array top
1236   // The linked list of vframe arrays are sorted on sp. This means when we
1237   // unpack the head must contain the vframe array to unpack.
1238   void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
1239   vframeArray* vframe_array_head() const         { return _vframe_array_head;  }
1240 
1241   // Side structure for defering update of java frame locals until deopt occurs
1242   GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred_locals() const { return _deferred_locals_updates; }
1243   void set_deferred_locals(GrowableArray<jvmtiDeferredLocalVariableSet *>* vf) { _deferred_locals_updates = vf; }
1244 
1245   // These only really exist to make debugging deopt problems simpler
1246 
1247   void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
1248   vframeArray* vframe_array_last() const         { return _vframe_array_last;  }
1249 
1250   // The special resourceMark used during deoptimization
1251 
1252   void set_deopt_mark(DeoptResourceMark* value)  { _deopt_mark = value; }
1253   DeoptResourceMark* deopt_mark(void)            { return _deopt_mark; }
1254 
1255   intptr_t* must_deopt_id()                      { return _must_deopt_id; }
1256   void     set_must_deopt_id(intptr_t* id)       { _must_deopt_id = id; }
1257   void     clear_must_deopt_id()                 { _must_deopt_id = NULL; }
1258 
1259   void set_deopt_nmethod(nmethod* nm)            { _deopt_nmethod = nm;   }
1260   nmethod* deopt_nmethod()                       { return _deopt_nmethod; }
1261 
1262   Method*    callee_target() const               { return _callee_target; }
1263   void set_callee_target  (Method* x)          { _callee_target   = x; }
1264 
1265   // Oop results of vm runtime calls
1266   oop  vm_result() const                         { return _vm_result; }
1267   void set_vm_result  (oop x)                    { _vm_result   = x; }
1268 
1269   Metadata*    vm_result_2() const               { return _vm_result_2; }
1270   void set_vm_result_2  (Metadata* x)          { _vm_result_2   = x; }
1271 
1272   MemRegion deferred_card_mark() const           { return _deferred_card_mark; }
1273   void set_deferred_card_mark(MemRegion mr)      { _deferred_card_mark = mr;   }
1274 
1275   // Exception handling for compiled methods
1276   oop      exception_oop() const                 { return _exception_oop; }
1277   address  exception_pc() const                  { return _exception_pc; }
1278   address  exception_handler_pc() const          { return _exception_handler_pc; }
1279   bool     is_method_handle_return() const       { return _is_method_handle_return == 1; }
1280 
1281   void set_exception_oop(oop o)                  { (void)const_cast<oop&>(_exception_oop = o); }
1282   void set_exception_pc(address a)               { _exception_pc = a; }
1283   void set_exception_handler_pc(address a)       { _exception_handler_pc = a; }
1284   void set_is_method_handle_return(bool value)   { _is_method_handle_return = value ? 1 : 0; }
1285 
1286   void clear_exception_oop_and_pc() {
1287     set_exception_oop(NULL);
1288     set_exception_pc(NULL);
1289   }
1290 
1291   // Stack overflow support
1292   inline size_t stack_available(address cur_sp);
1293   address stack_yellow_zone_base()
1294     { return (address)(stack_base() - (stack_size() - (stack_red_zone_size() + stack_yellow_zone_size()))); }
1295   size_t  stack_yellow_zone_size()
1296     { return StackYellowPages * os::vm_page_size(); }
1297   address stack_red_zone_base()
1298     { return (address)(stack_base() - (stack_size() - stack_red_zone_size())); }
1299   size_t stack_red_zone_size()
1300     { return StackRedPages * os::vm_page_size(); }
1301   bool in_stack_yellow_zone(address a)
1302     { return (a <= stack_yellow_zone_base()) && (a >= stack_red_zone_base()); }
1303   bool in_stack_red_zone(address a)
1304     { return (a <= stack_red_zone_base()) && (a >= (address)((intptr_t)stack_base() - stack_size())); }
1305 
1306   void create_stack_guard_pages();
1307   void remove_stack_guard_pages();
1308 
1309   void enable_stack_yellow_zone();
1310   void disable_stack_yellow_zone();
1311   void enable_stack_red_zone();
1312   void disable_stack_red_zone();
1313 
1314   inline bool stack_guard_zone_unused();
1315   inline bool stack_yellow_zone_disabled();
1316   inline bool stack_yellow_zone_enabled();
1317 
1318   // Attempt to reguard the stack after a stack overflow may have occurred.
1319   // Returns true if (a) guard pages are not needed on this thread, (b) the
1320   // pages are already guarded, or (c) the pages were successfully reguarded.
1321   // Returns false if there is not enough stack space to reguard the pages, in
1322   // which case the caller should unwind a frame and try again.  The argument
1323   // should be the caller's (approximate) sp.
1324   bool reguard_stack(address cur_sp);
1325   // Similar to above but see if current stackpoint is out of the guard area
1326   // and reguard if possible.
1327   bool reguard_stack(void);
1328 
1329   address stack_overflow_limit() { return _stack_overflow_limit; }
1330   void set_stack_overflow_limit() {
1331     _stack_overflow_limit = _stack_base - _stack_size +
1332                             ((StackShadowPages +
1333                               StackYellowPages +
1334                               StackRedPages) * os::vm_page_size());
1335   }
1336 
1337   // Misc. accessors/mutators
1338   void set_do_not_unlock(void)                   { _do_not_unlock_if_synchronized = true; }
1339   void clr_do_not_unlock(void)                   { _do_not_unlock_if_synchronized = false; }
1340   bool do_not_unlock(void)                       { return _do_not_unlock_if_synchronized; }
1341 
1342 #ifndef PRODUCT
1343   void record_jump(address target, address instr, const char* file, int line);
1344 #endif /* PRODUCT */
1345 
1346   // For assembly stub generation
1347   static ByteSize threadObj_offset()             { return byte_offset_of(JavaThread, _threadObj           ); }
1348 #ifndef PRODUCT
1349   static ByteSize jmp_ring_index_offset()        { return byte_offset_of(JavaThread, _jmp_ring_index      ); }
1350   static ByteSize jmp_ring_offset()              { return byte_offset_of(JavaThread, _jmp_ring            ); }
1351 #endif /* PRODUCT */
1352   static ByteSize jni_environment_offset()       { return byte_offset_of(JavaThread, _jni_environment     ); }
1353   static ByteSize last_Java_sp_offset()          {
1354     return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
1355   }
1356   static ByteSize last_Java_pc_offset()          {
1357     return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
1358   }
1359   static ByteSize frame_anchor_offset()          {
1360     return byte_offset_of(JavaThread, _anchor);
1361   }
1362   static ByteSize callee_target_offset()         { return byte_offset_of(JavaThread, _callee_target       ); }
1363   static ByteSize vm_result_offset()             { return byte_offset_of(JavaThread, _vm_result           ); }
1364   static ByteSize vm_result_2_offset()           { return byte_offset_of(JavaThread, _vm_result_2         ); }
1365   static ByteSize thread_state_offset()          { return byte_offset_of(JavaThread, _thread_state        ); }
1366   static ByteSize saved_exception_pc_offset()    { return byte_offset_of(JavaThread, _saved_exception_pc  ); }
1367   static ByteSize osthread_offset()              { return byte_offset_of(JavaThread, _osthread            ); }
1368   static ByteSize exception_oop_offset()         { return byte_offset_of(JavaThread, _exception_oop       ); }
1369   static ByteSize exception_pc_offset()          { return byte_offset_of(JavaThread, _exception_pc        ); }
1370   static ByteSize exception_handler_pc_offset()  { return byte_offset_of(JavaThread, _exception_handler_pc); }
1371   static ByteSize stack_overflow_limit_offset()  { return byte_offset_of(JavaThread, _stack_overflow_limit); }
1372   static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); }
1373   static ByteSize stack_guard_state_offset()     { return byte_offset_of(JavaThread, _stack_guard_state   ); }
1374   static ByteSize suspend_flags_offset()         { return byte_offset_of(JavaThread, _suspend_flags       ); }
1375 
1376   static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
1377   static ByteSize should_post_on_exceptions_flag_offset() {
1378     return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
1379   }
1380 
1381 #if INCLUDE_ALL_GCS
1382   static ByteSize satb_mark_queue_offset()       { return byte_offset_of(JavaThread, _satb_mark_queue); }
1383   static ByteSize dirty_card_queue_offset()      { return byte_offset_of(JavaThread, _dirty_card_queue); }
1384 #endif // INCLUDE_ALL_GCS
1385 
1386   // Returns the jni environment for this thread
1387   JNIEnv* jni_environment()                      { return &_jni_environment; }
1388 
1389   static JavaThread* thread_from_jni_environment(JNIEnv* env) {
1390     JavaThread *thread_from_jni_env = (JavaThread*)((intptr_t)env - in_bytes(jni_environment_offset()));
1391     // Only return NULL if thread is off the thread list; starting to
1392     // exit should not return NULL.
1393     if (thread_from_jni_env->is_terminated()) {
1394        thread_from_jni_env->block_if_vm_exited();
1395        return NULL;
1396     } else {
1397        return thread_from_jni_env;
1398     }
1399   }
1400 
1401   // JNI critical regions. These can nest.
1402   bool in_critical()    { return _jni_active_critical > 0; }
1403   bool in_last_critical()  { return _jni_active_critical == 1; }
1404   void enter_critical() { assert(Thread::current() == this ||
1405                                  Thread::current()->is_VM_thread() && SafepointSynchronize::is_synchronizing(),
1406                                  "this must be current thread or synchronizing");
1407                           _jni_active_critical++; }
1408   void exit_critical()  { assert(Thread::current() == this,
1409                                  "this must be current thread");
1410                           _jni_active_critical--;
1411                           assert(_jni_active_critical >= 0,
1412                                  "JNI critical nesting problem?"); }
1413 
1414   // Checked JNI, is the programmer required to check for exceptions, specify which function name
1415   bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != NULL; }
1416   void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = NULL; }
1417   const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; }
1418   void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; }
1419 
1420   // For deadlock detection
1421   int depth_first_number() { return _depth_first_number; }
1422   void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
1423 
1424  private:
1425   void set_monitor_chunks(MonitorChunk* monitor_chunks) { _monitor_chunks = monitor_chunks; }
1426 
1427  public:
1428   MonitorChunk* monitor_chunks() const           { return _monitor_chunks; }
1429   void add_monitor_chunk(MonitorChunk* chunk);
1430   void remove_monitor_chunk(MonitorChunk* chunk);
1431   bool in_deopt_handler() const                  { return _in_deopt_handler > 0; }
1432   void inc_in_deopt_handler()                    { _in_deopt_handler++; }
1433   void dec_in_deopt_handler()                    {
1434     assert(_in_deopt_handler > 0, "mismatched deopt nesting");
1435     if (_in_deopt_handler > 0) { // robustness
1436       _in_deopt_handler--;
1437     }
1438   }
1439 
1440  private:
1441   void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
1442 
1443  public:
1444 
1445   // Frame iteration; calls the function f for all frames on the stack
1446   void frames_do(void f(frame*, const RegisterMap*));
1447 
1448   // Memory operations
1449   void oops_do(OopClosure* f, CLDClosure* cld_f, CodeBlobClosure* cf);
1450 
1451   // Sweeper operations
1452   void nmethods_do(CodeBlobClosure* cf);
1453 
1454   // RedefineClasses Support
1455   void metadata_do(void f(Metadata*));
1456 
1457   // Memory management operations
1458   void gc_epilogue();
1459   void gc_prologue();
1460 
1461   // Misc. operations
1462   char* name() const { return (char*)get_thread_name(); }
1463   void print_on(outputStream* st) const;
1464   void print() const { print_on(tty); }
1465   void print_value();
1466   void print_thread_state_on(outputStream* ) const      PRODUCT_RETURN;
1467   void print_thread_state() const                       PRODUCT_RETURN;
1468   void print_on_error(outputStream* st, char* buf, int buflen) const;
1469   void verify();
1470   const char* get_thread_name() const;
1471 private:
1472   // factor out low-level mechanics for use in both normal and error cases
1473   const char* get_thread_name_string(char* buf = NULL, int buflen = 0) const;
1474 public:
1475   const char* get_threadgroup_name() const;
1476   const char* get_parent_name() const;
1477 
1478   // Accessing frames
1479   frame last_frame() {
1480     _anchor.make_walkable(this);
1481     return pd_last_frame();
1482   }
1483   javaVFrame* last_java_vframe(RegisterMap* reg_map);
1484 
1485   // Returns method at 'depth' java or native frames down the stack
1486   // Used for security checks
1487   Klass* security_get_caller_class(int depth);
1488 
1489   // Print stack trace in external format
1490   void print_stack_on(outputStream* st);
1491   void print_stack() { print_stack_on(tty); }
1492 
1493   // Print stack traces in various internal formats
1494   void trace_stack()                             PRODUCT_RETURN;
1495   void trace_stack_from(vframe* start_vf)        PRODUCT_RETURN;
1496   void trace_frames()                            PRODUCT_RETURN;
1497   void trace_oops()                              PRODUCT_RETURN;
1498 
1499   // Print an annotated view of the stack frames
1500   void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN;
1501   void validate_frame_layout() {
1502     print_frame_layout(0, true);
1503   }
1504 
1505   // Returns the number of stack frames on the stack
1506   int depth() const;
1507 
1508   // Function for testing deoptimization
1509   void deoptimize();
1510   void make_zombies();
1511 
1512   void deoptimized_wrt_marked_nmethods();
1513 
1514   // Profiling operation (see fprofile.cpp)
1515  public:
1516    bool profile_last_Java_frame(frame* fr);
1517 
1518  private:
1519    ThreadProfiler* _thread_profiler;
1520  private:
1521    friend class FlatProfiler;                    // uses both [gs]et_thread_profiler.
1522    friend class FlatProfilerTask;                // uses get_thread_profiler.
1523    friend class ThreadProfilerMark;              // uses get_thread_profiler.
1524    ThreadProfiler* get_thread_profiler()         { return _thread_profiler; }
1525    ThreadProfiler* set_thread_profiler(ThreadProfiler* tp) {
1526      ThreadProfiler* result = _thread_profiler;
1527      _thread_profiler = tp;
1528      return result;
1529    }
1530 
1531  public:
1532   // Returns the running thread as a JavaThread
1533   static inline JavaThread* current();
1534 
1535   // Returns the active Java thread.  Do not use this if you know you are calling
1536   // from a JavaThread, as it's slower than JavaThread::current.  If called from
1537   // the VMThread, it also returns the JavaThread that instigated the VMThread's
1538   // operation.  You may not want that either.
1539   static JavaThread* active();
1540 
1541   inline CompilerThread* as_CompilerThread();
1542 
1543  public:
1544   virtual void run();
1545   void thread_main_inner();
1546 
1547  private:
1548   // PRIVILEGED STACK
1549   PrivilegedElement*  _privileged_stack_top;
1550   GrowableArray<oop>* _array_for_gc;
1551  public:
1552 
1553   // Returns the privileged_stack information.
1554   PrivilegedElement* privileged_stack_top() const       { return _privileged_stack_top; }
1555   void set_privileged_stack_top(PrivilegedElement *e)   { _privileged_stack_top = e; }
1556   void register_array_for_gc(GrowableArray<oop>* array) { _array_for_gc = array; }
1557 
1558  public:
1559   // Thread local information maintained by JVMTI.
1560   void set_jvmti_thread_state(JvmtiThreadState *value)                           { _jvmti_thread_state = value; }
1561   // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1562   // getter is used to get this JavaThread's JvmtiThreadState if it has
1563   // one which means NULL can be returned. JvmtiThreadState::state_for()
1564   // is used to get the specified JavaThread's JvmtiThreadState if it has
1565   // one or it allocates a new JvmtiThreadState for the JavaThread and
1566   // returns it. JvmtiThreadState::state_for() will return NULL only if
1567   // the specified JavaThread is exiting.
1568   JvmtiThreadState *jvmti_thread_state() const                                   { return _jvmti_thread_state; }
1569   static ByteSize jvmti_thread_state_offset()                                    { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1570   void set_jvmti_get_loaded_classes_closure(JvmtiGetLoadedClassesClosure* value) { _jvmti_get_loaded_classes_closure = value; }
1571   JvmtiGetLoadedClassesClosure* get_jvmti_get_loaded_classes_closure() const     { return _jvmti_get_loaded_classes_closure; }
1572 
1573   // JVMTI PopFrame support
1574   // Setting and clearing popframe_condition
1575   // All of these enumerated values are bits. popframe_pending
1576   // indicates that a PopFrame() has been requested and not yet been
1577   // completed. popframe_processing indicates that that PopFrame() is in
1578   // the process of being completed. popframe_force_deopt_reexecution_bit
1579   // indicates that special handling is required when returning to a
1580   // deoptimized caller.
1581   enum PopCondition {
1582     popframe_inactive                      = 0x00,
1583     popframe_pending_bit                   = 0x01,
1584     popframe_processing_bit                = 0x02,
1585     popframe_force_deopt_reexecution_bit   = 0x04
1586   };
1587   PopCondition popframe_condition()                   { return (PopCondition) _popframe_condition; }
1588   void set_popframe_condition(PopCondition c)         { _popframe_condition = c; }
1589   void set_popframe_condition_bit(PopCondition c)     { _popframe_condition |= c; }
1590   void clear_popframe_condition()                     { _popframe_condition = popframe_inactive; }
1591   static ByteSize popframe_condition_offset()         { return byte_offset_of(JavaThread, _popframe_condition); }
1592   bool has_pending_popframe()                         { return (popframe_condition() & popframe_pending_bit) != 0; }
1593   bool popframe_forcing_deopt_reexecution()           { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
1594   void clear_popframe_forcing_deopt_reexecution()     { _popframe_condition &= ~popframe_force_deopt_reexecution_bit; }
1595 #ifdef CC_INTERP
1596   bool pop_frame_pending(void)                        { return ((_popframe_condition & popframe_pending_bit) != 0); }
1597   void clr_pop_frame_pending(void)                    { _popframe_condition = popframe_inactive; }
1598   bool pop_frame_in_process(void)                     { return ((_popframe_condition & popframe_processing_bit) != 0); }
1599   void set_pop_frame_in_process(void)                 { _popframe_condition |= popframe_processing_bit; }
1600   void clr_pop_frame_in_process(void)                 { _popframe_condition &= ~popframe_processing_bit; }
1601 #endif
1602 
1603   int frames_to_pop_failed_realloc() const            { return _frames_to_pop_failed_realloc; }
1604   void set_frames_to_pop_failed_realloc(int nb)       { _frames_to_pop_failed_realloc = nb; }
1605   void dec_frames_to_pop_failed_realloc()             { _frames_to_pop_failed_realloc--; }
1606 
1607  private:
1608   // Saved incoming arguments to popped frame.
1609   // Used only when popped interpreted frame returns to deoptimized frame.
1610   void*    _popframe_preserved_args;
1611   int      _popframe_preserved_args_size;
1612 
1613  public:
1614   void  popframe_preserve_args(ByteSize size_in_bytes, void* start);
1615   void* popframe_preserved_args();
1616   ByteSize popframe_preserved_args_size();
1617   WordSize popframe_preserved_args_size_in_words();
1618   void  popframe_free_preserved_args();
1619 
1620 
1621  private:
1622   JvmtiThreadState *_jvmti_thread_state;
1623   JvmtiGetLoadedClassesClosure* _jvmti_get_loaded_classes_closure;
1624 
1625   // Used by the interpreter in fullspeed mode for frame pop, method
1626   // entry, method exit and single stepping support. This field is
1627   // only set to non-zero by the VM_EnterInterpOnlyMode VM operation.
1628   // It can be set to zero asynchronously (i.e., without a VM operation
1629   // or a lock) so we have to be very careful.
1630   int               _interp_only_mode;
1631 
1632  public:
1633   // used by the interpreter for fullspeed debugging support (see above)
1634   static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
1635   bool is_interp_only_mode()                { return (_interp_only_mode != 0); }
1636   int get_interp_only_mode()                { return _interp_only_mode; }
1637   void increment_interp_only_mode()         { ++_interp_only_mode; }
1638   void decrement_interp_only_mode()         { --_interp_only_mode; }
1639 
1640   // support for cached flag that indicates whether exceptions need to be posted for this thread
1641   // if this is false, we can avoid deoptimizing when events are thrown
1642   // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
1643  private:
1644   int    _should_post_on_exceptions_flag;
1645 
1646  public:
1647   int   should_post_on_exceptions_flag()  { return _should_post_on_exceptions_flag; }
1648   void  set_should_post_on_exceptions_flag(int val)  { _should_post_on_exceptions_flag = val; }
1649 
1650  private:
1651   ThreadStatistics *_thread_stat;
1652 
1653  public:
1654   ThreadStatistics* get_thread_stat() const    { return _thread_stat; }
1655 
1656   // Return a blocker object for which this thread is blocked parking.
1657   oop current_park_blocker();
1658 
1659  private:
1660   static size_t _stack_size_at_create;
1661 
1662  public:
1663   static inline size_t stack_size_at_create(void) {
1664     return _stack_size_at_create;
1665   }
1666   static inline void set_stack_size_at_create(size_t value) {
1667     _stack_size_at_create = value;
1668   }
1669 
1670 #if INCLUDE_ALL_GCS
1671   // SATB marking queue support
1672   ObjPtrQueue& satb_mark_queue() { return _satb_mark_queue; }
1673   static SATBMarkQueueSet& satb_mark_queue_set() {
1674     return _satb_mark_queue_set;
1675   }
1676 
1677   // Dirty card queue support
1678   DirtyCardQueue& dirty_card_queue() { return _dirty_card_queue; }
1679   static DirtyCardQueueSet& dirty_card_queue_set() {
1680     return _dirty_card_queue_set;
1681   }
1682 #endif // INCLUDE_ALL_GCS
1683 
1684   // This method initializes the SATB and dirty card queues before a
1685   // JavaThread is added to the Java thread list. Right now, we don't
1686   // have to do anything to the dirty card queue (it should have been
1687   // activated when the thread was created), but we have to activate
1688   // the SATB queue if the thread is created while a marking cycle is
1689   // in progress. The activation / de-activation of the SATB queues at
1690   // the beginning / end of a marking cycle is done during safepoints
1691   // so we have to make sure this method is called outside one to be
1692   // able to safely read the active field of the SATB queue set. Right
1693   // now, it is called just before the thread is added to the Java
1694   // thread list in the Threads::add() method. That method is holding
1695   // the Threads_lock which ensures we are outside a safepoint. We
1696   // cannot do the obvious and set the active field of the SATB queue
1697   // when the thread is created given that, in some cases, safepoints
1698   // might happen between the JavaThread constructor being called and the
1699   // thread being added to the Java thread list (an example of this is
1700   // when the structure for the DestroyJavaVM thread is created).
1701 #if INCLUDE_ALL_GCS
1702   void initialize_queues();
1703 #else  // INCLUDE_ALL_GCS
1704   void initialize_queues() { }
1705 #endif // INCLUDE_ALL_GCS
1706 
1707   // Machine dependent stuff
1708 #ifdef TARGET_OS_ARCH_linux_x86
1709 # include "thread_linux_x86.hpp"
1710 #endif
1711 #ifdef TARGET_OS_ARCH_linux_sparc
1712 # include "thread_linux_sparc.hpp"
1713 #endif
1714 #ifdef TARGET_OS_ARCH_linux_zero
1715 # include "thread_linux_zero.hpp"
1716 #endif
1717 #ifdef TARGET_OS_ARCH_solaris_x86
1718 # include "thread_solaris_x86.hpp"
1719 #endif
1720 #ifdef TARGET_OS_ARCH_solaris_sparc
1721 # include "thread_solaris_sparc.hpp"
1722 #endif
1723 #ifdef TARGET_OS_ARCH_windows_x86
1724 # include "thread_windows_x86.hpp"
1725 #endif
1726 #ifdef TARGET_OS_ARCH_linux_arm
1727 # include "thread_linux_arm.hpp"
1728 #endif
1729 #ifdef TARGET_OS_ARCH_linux_ppc
1730 # include "thread_linux_ppc.hpp"
1731 #endif
1732 #ifdef TARGET_OS_ARCH_aix_ppc
1733 # include "thread_aix_ppc.hpp"
1734 #endif
1735 #ifdef TARGET_OS_ARCH_bsd_x86
1736 # include "thread_bsd_x86.hpp"
1737 #endif
1738 #ifdef TARGET_OS_ARCH_bsd_zero
1739 # include "thread_bsd_zero.hpp"
1740 #endif
1741 
1742 
1743  public:
1744   void set_blocked_on_compilation(bool value) {
1745     _blocked_on_compilation = value;
1746   }
1747 
1748   bool blocked_on_compilation() {
1749     return _blocked_on_compilation;
1750   }
1751  protected:
1752   bool         _blocked_on_compilation;
1753 
1754 
1755   // JSR166 per-thread parker
1756 private:
1757   Parker*    _parker;
1758 public:
1759   Parker*     parker() { return _parker; }
1760 
1761   // Biased locking support
1762 private:
1763   GrowableArray<MonitorInfo*>* _cached_monitor_info;
1764 public:
1765   GrowableArray<MonitorInfo*>* cached_monitor_info() { return _cached_monitor_info; }
1766   void set_cached_monitor_info(GrowableArray<MonitorInfo*>* info) { _cached_monitor_info = info; }
1767 
1768   // clearing/querying jni attach status
1769   bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; }
1770   bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
1771   inline void set_done_attaching_via_jni();
1772 private:
1773   // This field is used to determine if a thread has claimed
1774   // a par_id: it is UINT_MAX if the thread has not claimed a par_id;
1775   // otherwise its value is the par_id that has been claimed.
1776   uint _claimed_par_id;
1777 public:
1778   uint get_claimed_par_id() { return _claimed_par_id; }
1779   void set_claimed_par_id(uint id) { _claimed_par_id = id;}
1780 };
1781 
1782 // Inline implementation of JavaThread::current
1783 inline JavaThread* JavaThread::current() {
1784   Thread* thread = ThreadLocalStorage::thread();
1785   assert(thread != NULL && thread->is_Java_thread(), "just checking");
1786   return (JavaThread*)thread;
1787 }
1788 
1789 inline CompilerThread* JavaThread::as_CompilerThread() {
1790   assert(is_Compiler_thread(), "just checking");
1791   return (CompilerThread*)this;
1792 }
1793 
1794 inline bool JavaThread::stack_guard_zone_unused() {
1795   return _stack_guard_state == stack_guard_unused;
1796 }
1797 
1798 inline bool JavaThread::stack_yellow_zone_disabled() {
1799   return _stack_guard_state == stack_guard_yellow_disabled;
1800 }
1801 
1802 inline bool JavaThread::stack_yellow_zone_enabled() {
1803 #ifdef ASSERT
1804   if (os::uses_stack_guard_pages()) {
1805     assert(_stack_guard_state != stack_guard_unused, "guard pages must be in use");
1806   }
1807 #endif
1808     return _stack_guard_state == stack_guard_enabled;
1809 }
1810 
1811 inline size_t JavaThread::stack_available(address cur_sp) {
1812   // This code assumes java stacks grow down
1813   address low_addr; // Limit on the address for deepest stack depth
1814   if ( _stack_guard_state == stack_guard_unused) {
1815     low_addr =  stack_base() - stack_size();
1816   } else {
1817     low_addr = stack_yellow_zone_base();
1818   }
1819   return cur_sp > low_addr ? cur_sp - low_addr : 0;
1820 }
1821 
1822 // A thread used for Compilation.
1823 class CompilerThread : public JavaThread {
1824   friend class VMStructs;
1825  private:
1826   CompilerCounters* _counters;
1827 
1828   ciEnv*            _env;
1829   CompileLog*       _log;
1830   CompileTask*      _task;
1831   CompileQueue*     _queue;
1832   BufferBlob*       _buffer_blob;
1833 
1834   nmethod*          _scanned_nmethod;  // nmethod being scanned by the sweeper
1835   AbstractCompiler* _compiler;
1836 
1837  public:
1838 
1839   static CompilerThread* current();
1840 
1841   CompilerThread(CompileQueue* queue, CompilerCounters* counters);
1842 
1843   bool is_Compiler_thread() const                { return true; }
1844   // Hide this compiler thread from external view.
1845   bool is_hidden_from_external_view() const      { return true; }
1846 
1847   void set_compiler(AbstractCompiler* c)         { _compiler = c; }
1848   AbstractCompiler* compiler() const             { return _compiler; }
1849 
1850   CompileQueue* queue()        const             { return _queue; }
1851   CompilerCounters* counters() const             { return _counters; }
1852 
1853   // Get/set the thread's compilation environment.
1854   ciEnv*        env()                            { return _env; }
1855   void          set_env(ciEnv* env)              { _env = env; }
1856 
1857   BufferBlob*   get_buffer_blob() const          { return _buffer_blob; }
1858   void          set_buffer_blob(BufferBlob* b)   { _buffer_blob = b; };
1859 
1860   // Get/set the thread's logging information
1861   CompileLog*   log()                            { return _log; }
1862   void          init_log(CompileLog* log) {
1863     // Set once, for good.
1864     assert(_log == NULL, "set only once");
1865     _log = log;
1866   }
1867 
1868   // GC support
1869   // Apply "f->do_oop" to all root oops in "this".
1870   // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames
1871   void oops_do(OopClosure* f, CLDClosure* cld_f, CodeBlobClosure* cf);
1872 
1873 #ifndef PRODUCT
1874 private:
1875   IdealGraphPrinter *_ideal_graph_printer;
1876 public:
1877   IdealGraphPrinter *ideal_graph_printer()                       { return _ideal_graph_printer; }
1878   void set_ideal_graph_printer(IdealGraphPrinter *n)             { _ideal_graph_printer = n; }
1879 #endif
1880 
1881   // Get/set the thread's current task
1882   CompileTask*  task()                           { return _task; }
1883   void          set_task(CompileTask* task)      { _task = task; }
1884 
1885   // Track the nmethod currently being scanned by the sweeper
1886   void          set_scanned_nmethod(nmethod* nm) {
1887     assert(_scanned_nmethod == NULL || nm == NULL, "should reset to NULL before writing a new value");
1888     _scanned_nmethod = nm;
1889   }
1890 };
1891 
1892 inline CompilerThread* CompilerThread::current() {
1893   return JavaThread::current()->as_CompilerThread();
1894 }
1895 
1896 
1897 // The active thread queue. It also keeps track of the current used
1898 // thread priorities.
1899 class Threads: AllStatic {
1900   friend class VMStructs;
1901  private:
1902   static JavaThread* _thread_list;
1903   static int         _number_of_threads;
1904   static int         _number_of_non_daemon_threads;
1905   static int         _return_code;
1906 #ifdef ASSERT
1907   static bool        _vm_complete;
1908 #endif
1909 
1910  public:
1911   // Thread management
1912   // force_daemon is a concession to JNI, where we may need to add a
1913   // thread to the thread list before allocating its thread object
1914   static void add(JavaThread* p, bool force_daemon = false);
1915   static void remove(JavaThread* p);
1916   static bool includes(JavaThread* p);
1917   static JavaThread* first()                     { return _thread_list; }
1918   static void threads_do(ThreadClosure* tc);
1919 
1920   // Initializes the vm and creates the vm thread
1921   static jint create_vm(JavaVMInitArgs* args, bool* canTryAgain);
1922   static void convert_vm_init_libraries_to_agents();
1923   static void create_vm_init_libraries();
1924   static void create_vm_init_agents();
1925   static void shutdown_vm_agents();
1926   static bool destroy_vm();
1927   // Supported VM versions via JNI
1928   // Includes JNI_VERSION_1_1
1929   static jboolean is_supported_jni_version_including_1_1(jint version);
1930   // Does not include JNI_VERSION_1_1
1931   static jboolean is_supported_jni_version(jint version);
1932 
1933   // Garbage collection
1934   static void follow_other_roots(void f(oop*));
1935 
1936   // Apply "f->do_oop" to all root oops in all threads.
1937   // This version may only be called by sequential code.
1938   static void oops_do(OopClosure* f, CLDClosure* cld_f, CodeBlobClosure* cf);
1939   // This version may be called by sequential or parallel code.
1940   static void possibly_parallel_oops_do(OopClosure* f, CLDClosure* cld_f, CodeBlobClosure* cf);
1941   // This creates a list of GCTasks, one per thread.
1942   static void create_thread_roots_tasks(GCTaskQueue* q);
1943   // This creates a list of GCTasks, one per thread, for marking objects.
1944   static void create_thread_roots_marking_tasks(GCTaskQueue* q);
1945 
1946   // Apply "f->do_oop" to roots in all threads that
1947   // are part of compiled frames
1948   static void compiled_frame_oops_do(OopClosure* f, CodeBlobClosure* cf);
1949 
1950   static void convert_hcode_pointers();
1951   static void restore_hcode_pointers();
1952 
1953   // Sweeper
1954   static void nmethods_do(CodeBlobClosure* cf);
1955 
1956   // RedefineClasses support
1957   static void metadata_do(void f(Metadata*));
1958 
1959   static void gc_epilogue();
1960   static void gc_prologue();
1961 #ifdef ASSERT
1962   static bool is_vm_complete() { return _vm_complete; }
1963 #endif
1964 
1965   // Verification
1966   static void verify();
1967   static void print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks);
1968   static void print(bool print_stacks, bool internal_format) {
1969     // this function is only used by debug.cpp
1970     print_on(tty, print_stacks, internal_format, false /* no concurrent lock printed */);
1971   }
1972   static void print_on_error(outputStream* st, Thread* current, char* buf, int buflen);
1973 
1974   // Get Java threads that are waiting to enter a monitor. If doLock
1975   // is true, then Threads_lock is grabbed as needed. Otherwise, the
1976   // VM needs to be at a safepoint.
1977   static GrowableArray<JavaThread*>* get_pending_threads(int count,
1978     address monitor, bool doLock);
1979 
1980   // Get owning Java thread from the monitor's owner field. If doLock
1981   // is true, then Threads_lock is grabbed as needed. Otherwise, the
1982   // VM needs to be at a safepoint.
1983   static JavaThread *owning_thread_from_monitor_owner(address owner,
1984     bool doLock);
1985 
1986   // Number of threads on the active threads list
1987   static int number_of_threads()                 { return _number_of_threads; }
1988   // Number of non-daemon threads on the active threads list
1989   static int number_of_non_daemon_threads()      { return _number_of_non_daemon_threads; }
1990 
1991   // Deoptimizes all frames tied to marked nmethods
1992   static void deoptimized_wrt_marked_nmethods();
1993 
1994   static JavaThread* find_java_thread_from_java_tid(jlong java_tid);
1995 
1996 };
1997 
1998 
1999 // Thread iterator
2000 class ThreadClosure: public StackObj {
2001  public:
2002   virtual void do_thread(Thread* thread) = 0;
2003 };
2004 
2005 class SignalHandlerMark: public StackObj {
2006 private:
2007   Thread* _thread;
2008 public:
2009   SignalHandlerMark(Thread* t) {
2010     _thread = t;
2011     if (_thread) _thread->enter_signal_handler();
2012   }
2013   ~SignalHandlerMark() {
2014     if (_thread) _thread->leave_signal_handler();
2015     _thread = NULL;
2016   }
2017 };
2018 
2019 
2020 #endif // SHARE_VM_RUNTIME_THREAD_HPP