1 /*
   2  * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_RUNTIME_THREAD_HPP
  26 #define SHARE_VM_RUNTIME_THREAD_HPP
  27 
  28 #include "memory/allocation.hpp"
  29 #include "memory/threadLocalAllocBuffer.hpp"
  30 #include "oops/oop.hpp"
  31 #include "prims/jni.h"
  32 #include "prims/jvmtiExport.hpp"
  33 #include "runtime/frame.hpp"
  34 #include "runtime/javaFrameAnchor.hpp"
  35 #include "runtime/jniHandles.hpp"
  36 #include "runtime/mutexLocker.hpp"
  37 #include "runtime/os.hpp"
  38 #include "runtime/osThread.hpp"
  39 #include "runtime/park.hpp"
  40 #include "runtime/safepoint.hpp"
  41 #include "runtime/stubRoutines.hpp"
  42 #include "runtime/threadLocalStorage.hpp"
  43 #include "runtime/thread_ext.hpp"
  44 #include "runtime/unhandledOops.hpp"
  45 #include "utilities/exceptions.hpp"
  46 #include "utilities/macros.hpp"
  47 #include "utilities/top.hpp"
  48 #if INCLUDE_ALL_GCS
  49 #include "gc_implementation/g1/dirtyCardQueue.hpp"
  50 #include "gc_implementation/g1/satbQueue.hpp"
  51 #endif // INCLUDE_ALL_GCS
  52 #ifdef TARGET_ARCH_zero
  53 # include "stack_zero.hpp"
  54 #endif
  55 #if INCLUDE_JFR
  56 #include "jfr/support/jfrThreadExtension.hpp"
  57 #endif
  58 
  59 class ThreadSafepointState;
  60 class ThreadProfiler;
  61 
  62 class JvmtiThreadState;
  63 class JvmtiGetLoadedClassesClosure;
  64 class ThreadStatistics;
  65 class ConcurrentLocksDump;
  66 class ParkEvent;
  67 class Parker;
  68 
  69 class ciEnv;
  70 class CompileThread;
  71 class CompileLog;
  72 class CompileTask;
  73 class CompileQueue;
  74 class CompilerCounters;
  75 class vframeArray;
  76 
  77 class DeoptResourceMark;
  78 class jvmtiDeferredLocalVariableSet;
  79 
  80 class GCTaskQueue;
  81 class ThreadClosure;
  82 class IdealGraphPrinter;
  83 
  84 class Metadata;
  85 template <class T, MEMFLAGS F> class ChunkedList;
  86 typedef ChunkedList<Metadata*, mtInternal> MetadataOnStackBuffer;
  87 
  88 DEBUG_ONLY(class ResourceMark;)
  89 
  90 class WorkerThread;
  91 
  92 // Class hierarchy
  93 // - Thread
  94 //   - NamedThread
  95 //     - VMThread
  96 //     - ConcurrentGCThread
  97 //     - WorkerThread
  98 //       - GangWorker
  99 //       - GCTaskThread
 100 //   - JavaThread
 101 //   - WatcherThread
 102 
 103 class Thread: public ThreadShadow {
 104   friend class VMStructs;
 105 
 106 #if INCLUDE_ALL_GCS
 107 protected:
 108   // Support for Shenandoah barriers. This is only accessible from JavaThread,
 109   // but we really want to keep this field at lower Thread offset (below first
 110   // 128 bytes), because that makes barrier fastpaths optimally encoded.
 111   char _gc_state;
 112   static char _gc_state_global;
 113 #endif
 114 
 115  private:
 116   // Exception handling
 117   // (Note: _pending_exception and friends are in ThreadShadow)
 118   //oop       _pending_exception;                // pending exception for current thread
 119   // const char* _exception_file;                   // file information for exception (debugging only)
 120   // int         _exception_line;                   // line information for exception (debugging only)
 121  protected:
 122   // Support for forcing alignment of thread objects for biased locking
 123   void*       _real_malloc_address;
 124  public:
 125   void* operator new(size_t size) throw() { return allocate(size, true); }
 126   void* operator new(size_t size, const std::nothrow_t& nothrow_constant) throw() {
 127     return allocate(size, false); }
 128   void  operator delete(void* p);
 129 
 130  protected:
 131    static void* allocate(size_t size, bool throw_excpt, MEMFLAGS flags = mtThread);
 132  private:
 133 
 134   // ***************************************************************
 135   // Suspend and resume support
 136   // ***************************************************************
 137   //
 138   // VM suspend/resume no longer exists - it was once used for various
 139   // things including safepoints but was deprecated and finally removed
 140   // in Java 7. Because VM suspension was considered "internal" Java-level
 141   // suspension was considered "external", and this legacy naming scheme
 142   // remains.
 143   //
 144   // External suspend/resume requests come from JVM_SuspendThread,
 145   // JVM_ResumeThread, JVMTI SuspendThread, and finally JVMTI
 146   // ResumeThread. External
 147   // suspend requests cause _external_suspend to be set and external
 148   // resume requests cause _external_suspend to be cleared.
 149   // External suspend requests do not nest on top of other external
 150   // suspend requests. The higher level APIs reject suspend requests
 151   // for already suspended threads.
 152   //
 153   // The external_suspend
 154   // flag is checked by has_special_runtime_exit_condition() and java thread
 155   // will self-suspend when handle_special_runtime_exit_condition() is
 156   // called. Most uses of the _thread_blocked state in JavaThreads are
 157   // considered the same as being externally suspended; if the blocking
 158   // condition lifts, the JavaThread will self-suspend. Other places
 159   // where VM checks for external_suspend include:
 160   //   + mutex granting (do not enter monitors when thread is suspended)
 161   //   + state transitions from _thread_in_native
 162   //
 163   // In general, java_suspend() does not wait for an external suspend
 164   // request to complete. When it returns, the only guarantee is that
 165   // the _external_suspend field is true.
 166   //
 167   // wait_for_ext_suspend_completion() is used to wait for an external
 168   // suspend request to complete. External suspend requests are usually
 169   // followed by some other interface call that requires the thread to
 170   // be quiescent, e.g., GetCallTrace(). By moving the "wait time" into
 171   // the interface that requires quiescence, we give the JavaThread a
 172   // chance to self-suspend before we need it to be quiescent. This
 173   // improves overall suspend/query performance.
 174   //
 175   // _suspend_flags controls the behavior of java_ suspend/resume.
 176   // It must be set under the protection of SR_lock. Read from the flag is
 177   // OK without SR_lock as long as the value is only used as a hint.
 178   // (e.g., check _external_suspend first without lock and then recheck
 179   // inside SR_lock and finish the suspension)
 180   //
 181   // _suspend_flags is also overloaded for other "special conditions" so
 182   // that a single check indicates whether any special action is needed
 183   // eg. for async exceptions.
 184   // -------------------------------------------------------------------
 185   // Notes:
 186   // 1. The suspend/resume logic no longer uses ThreadState in OSThread
 187   // but we still update its value to keep other part of the system (mainly
 188   // JVMTI) happy. ThreadState is legacy code (see notes in
 189   // osThread.hpp).
 190   //
 191   // 2. It would be more natural if set_external_suspend() is private and
 192   // part of java_suspend(), but that probably would affect the suspend/query
 193   // performance. Need more investigation on this.
 194   //
 195 
 196   // suspend/resume lock: used for self-suspend
 197   Monitor* _SR_lock;
 198 
 199  protected:
 200   enum SuspendFlags {
 201     // NOTE: avoid using the sign-bit as cc generates different test code
 202     //       when the sign-bit is used, and sometimes incorrectly - see CR 6398077
 203 
 204     _external_suspend       = 0x20000000U, // thread is asked to self suspend
 205     _ext_suspended          = 0x40000000U, // thread has self-suspended
 206     _deopt_suspend          = 0x10000000U, // thread needs to self suspend for deopt
 207 
 208     _has_async_exception    = 0x00000001U, // there is a pending async exception
 209     _critical_native_unlock = 0x00000002U, // Must call back to unlock JNI critical lock
 210 
 211     JFR_ONLY(_trace_flag    = 0x00000004U)  // call jfr tracing
 212   };
 213 
 214   // various suspension related flags - atomically updated
 215   // overloaded for async exception checking in check_special_condition_for_native_trans.
 216   volatile uint32_t _suspend_flags;
 217 
 218  private:
 219   int _num_nested_signal;
 220 
 221  public:
 222   void enter_signal_handler() { _num_nested_signal++; }
 223   void leave_signal_handler() { _num_nested_signal--; }
 224   bool is_inside_signal_handler() const { return _num_nested_signal > 0; }
 225 
 226  private:
 227   // Debug tracing
 228   static void trace(const char* msg, const Thread* const thread) PRODUCT_RETURN;
 229 
 230   // Active_handles points to a block of handles
 231   JNIHandleBlock* _active_handles;
 232 
 233   // One-element thread local free list
 234   JNIHandleBlock* _free_handle_block;
 235 
 236   // Point to the last handle mark
 237   HandleMark* _last_handle_mark;
 238 
 239   // The parity of the last strong_roots iteration in which this thread was
 240   // claimed as a task.
 241   jint _oops_do_parity;
 242 
 243   public:
 244    void set_last_handle_mark(HandleMark* mark)   { _last_handle_mark = mark; }
 245    HandleMark* last_handle_mark() const          { return _last_handle_mark; }
 246   private:
 247 
 248   // debug support for checking if code does allow safepoints or not
 249   // GC points in the VM can happen because of allocation, invoking a VM operation, or blocking on
 250   // mutex, or blocking on an object synchronizer (Java locking).
 251   // If !allow_safepoint(), then an assertion failure will happen in any of the above cases
 252   // If !allow_allocation(), then an assertion failure will happen during allocation
 253   // (Hence, !allow_safepoint() => !allow_allocation()).
 254   //
 255   // The two classes No_Safepoint_Verifier and No_Allocation_Verifier are used to set these counters.
 256   //
 257   NOT_PRODUCT(int _allow_safepoint_count;)      // If 0, thread allow a safepoint to happen
 258   debug_only (int _allow_allocation_count;)     // If 0, the thread is allowed to allocate oops.
 259 
 260   // Used by SkipGCALot class.
 261   NOT_PRODUCT(bool _skip_gcalot;)               // Should we elide gc-a-lot?
 262 
 263   friend class No_Alloc_Verifier;
 264   friend class No_Safepoint_Verifier;
 265   friend class Pause_No_Safepoint_Verifier;
 266   friend class ThreadLocalStorage;
 267   friend class GC_locker;
 268 
 269   ThreadLocalAllocBuffer _tlab;                 // Thread-local eden
 270   ThreadLocalAllocBuffer _gclab;                // Thread-local allocation buffer for GC (e.g. evacuation)
 271   uint _worker_id;                              // Worker ID
 272   bool _force_satb_flush;                       // Force SATB flush
 273   double _paced_time;                           // Accumulated paced time
 274 
 275   jlong _allocated_bytes;                       // Cumulative number of bytes allocated on
 276                                                 // the Java heap
 277   jlong _allocated_bytes_gclab;                 // Cumulative number of bytes allocated on
 278                                                 // the Java heap, in GCLABs
 279 
 280   // Thread-local buffer used by MetadataOnStackMark.
 281   MetadataOnStackBuffer* _metadata_on_stack_buffer;
 282 
 283   JFR_ONLY(DEFINE_THREAD_LOCAL_FIELD_JFR;)      // Thread-local data for jfr
 284 
 285   ThreadExt _ext;
 286 
 287   int   _vm_operation_started_count;            // VM_Operation support
 288   int   _vm_operation_completed_count;          // VM_Operation support
 289 
 290   char _oom_during_evac;
 291 
 292   ObjectMonitor* _current_pending_monitor;      // ObjectMonitor this thread
 293                                                 // is waiting to lock
 294   bool _current_pending_monitor_is_from_java;   // locking is from Java code
 295 
 296   // ObjectMonitor on which this thread called Object.wait()
 297   ObjectMonitor* _current_waiting_monitor;
 298 
 299   // Private thread-local objectmonitor list - a simple cache organized as a SLL.
 300  public:
 301   ObjectMonitor* omFreeList;
 302   int omFreeCount;                              // length of omFreeList
 303   int omFreeProvision;                          // reload chunk size
 304   ObjectMonitor* omInUseList;                   // SLL to track monitors in circulation
 305   int omInUseCount;                             // length of omInUseList
 306 
 307 #ifdef ASSERT
 308  private:
 309   bool _visited_for_critical_count;
 310 
 311  public:
 312   void set_visited_for_critical_count(bool z) { _visited_for_critical_count = z; }
 313   bool was_visited_for_critical_count() const   { return _visited_for_critical_count; }
 314 #endif
 315 
 316  public:
 317   enum {
 318     is_definitely_current_thread = true
 319   };
 320 
 321   // Constructor
 322   Thread();
 323   virtual ~Thread();
 324 
 325   // initializtion
 326   void initialize_thread_local_storage();
 327 
 328   // thread entry point
 329   virtual void run();
 330 
 331   // Testers
 332   virtual bool is_VM_thread()       const            { return false; }
 333   virtual bool is_Java_thread()     const            { return false; }
 334   virtual bool is_Compiler_thread() const            { return false; }
 335   virtual bool is_hidden_from_external_view() const  { return false; }
 336   virtual bool is_jvmti_agent_thread() const         { return false; }
 337   // True iff the thread can perform GC operations at a safepoint.
 338   // Generally will be true only of VM thread and parallel GC WorkGang
 339   // threads.
 340   virtual bool is_GC_task_thread() const             { return false; }
 341   virtual bool is_Watcher_thread() const             { return false; }
 342   virtual bool is_ConcurrentGC_thread() const        { return false; }
 343   virtual bool is_Named_thread() const               { return false; }
 344   virtual bool is_Worker_thread() const              { return false; }
 345 
 346   // Casts
 347   virtual WorkerThread* as_Worker_thread() const     { return NULL; }
 348 
 349   virtual char* name() const { return (char*)"Unknown thread"; }
 350 
 351   // Returns the current thread
 352   static inline Thread* current();
 353   static inline Thread* current_or_null();
 354 
 355   // Common thread operations
 356   static void set_priority(Thread* thread, ThreadPriority priority);
 357   static ThreadPriority get_priority(const Thread* const thread);
 358   static void start(Thread* thread);
 359   static void interrupt(Thread* thr);
 360   static bool is_interrupted(Thread* thr, bool clear_interrupted);
 361 
 362   void set_native_thread_name(const char *name) {
 363     assert(Thread::current() == this, "set_native_thread_name can only be called on the current thread");
 364     os::set_native_thread_name(name);
 365   }
 366 
 367   ObjectMonitor** omInUseList_addr()             { return (ObjectMonitor **)&omInUseList; }
 368   Monitor* SR_lock() const                       { return _SR_lock; }
 369 
 370   bool has_async_exception() const { return (_suspend_flags & _has_async_exception) != 0; }
 371 
 372   void set_suspend_flag(SuspendFlags f) {
 373     assert(sizeof(jint) == sizeof(_suspend_flags), "size mismatch");
 374     uint32_t flags;
 375     do {
 376       flags = _suspend_flags;
 377     }
 378     while (Atomic::cmpxchg((jint)(flags | f),
 379                            (volatile jint*)&_suspend_flags,
 380                            (jint)flags) != (jint)flags);
 381   }
 382   void clear_suspend_flag(SuspendFlags f) {
 383     assert(sizeof(jint) == sizeof(_suspend_flags), "size mismatch");
 384     uint32_t flags;
 385     do {
 386       flags = _suspend_flags;
 387     }
 388     while (Atomic::cmpxchg((jint)(flags & ~f),
 389                            (volatile jint*)&_suspend_flags,
 390                            (jint)flags) != (jint)flags);
 391   }
 392 
 393   void set_has_async_exception() {
 394     set_suspend_flag(_has_async_exception);
 395   }
 396   void clear_has_async_exception() {
 397     clear_suspend_flag(_has_async_exception);
 398   }
 399 
 400   bool do_critical_native_unlock() const { return (_suspend_flags & _critical_native_unlock) != 0; }
 401 
 402   void set_critical_native_unlock() {
 403     set_suspend_flag(_critical_native_unlock);
 404   }
 405   void clear_critical_native_unlock() {
 406     clear_suspend_flag(_critical_native_unlock);
 407   }
 408 
 409   bool is_oom_during_evac() const;
 410   void set_oom_during_evac(bool oom);
 411 
 412 #ifdef ASSERT
 413   bool is_evac_allowed() const;
 414   void set_evac_allowed(bool evac_allowed);
 415 #endif
 416 
 417   // Support for Unhandled Oop detection
 418 #ifdef CHECK_UNHANDLED_OOPS
 419  private:
 420   UnhandledOops* _unhandled_oops;
 421  public:
 422   UnhandledOops* unhandled_oops() { return _unhandled_oops; }
 423   // Mark oop safe for gc.  It may be stack allocated but won't move.
 424   void allow_unhandled_oop(oop *op) {
 425     if (CheckUnhandledOops) unhandled_oops()->allow_unhandled_oop(op);
 426   }
 427   // Clear oops at safepoint so crashes point to unhandled oop violator
 428   void clear_unhandled_oops() {
 429     if (CheckUnhandledOops) unhandled_oops()->clear_unhandled_oops();
 430   }
 431 #endif // CHECK_UNHANDLED_OOPS
 432 
 433 #ifndef PRODUCT
 434   bool skip_gcalot()           { return _skip_gcalot; }
 435   void set_skip_gcalot(bool v) { _skip_gcalot = v;    }
 436 #endif
 437 
 438  public:
 439   // Installs a pending exception to be inserted later
 440   static void send_async_exception(oop thread_oop, oop java_throwable);
 441 
 442   // Resource area
 443   ResourceArea* resource_area() const            { return _resource_area; }
 444   void set_resource_area(ResourceArea* area)     { _resource_area = area; }
 445 
 446   OSThread* osthread() const                     { return _osthread;   }
 447   void set_osthread(OSThread* thread)            { _osthread = thread; }
 448 
 449   // JNI handle support
 450   JNIHandleBlock* active_handles() const         { return _active_handles; }
 451   void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
 452   JNIHandleBlock* free_handle_block() const      { return _free_handle_block; }
 453   void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
 454 
 455   // Internal handle support
 456   HandleArea* handle_area() const                { return _handle_area; }
 457   void set_handle_area(HandleArea* area)         { _handle_area = area; }
 458 
 459   GrowableArray<Metadata*>* metadata_handles() const          { return _metadata_handles; }
 460   void set_metadata_handles(GrowableArray<Metadata*>* handles){ _metadata_handles = handles; }
 461 
 462   // Thread-Local Allocation Buffer (TLAB) support
 463   ThreadLocalAllocBuffer& tlab()                 { return _tlab; }
 464   void initialize_tlab() {
 465     if (UseTLAB) {
 466       tlab().initialize(false);
 467       if (UseShenandoahGC && (is_Java_thread() || is_Worker_thread())) {
 468         gclab().initialize(true);
 469       }
 470     }
 471   }
 472 
 473   // Thread-Local GC Allocation Buffer (GCLAB) support
 474   ThreadLocalAllocBuffer& gclab()                {
 475     assert (UseShenandoahGC, "Only for Shenandoah");
 476     assert (!_gclab.is_initialized() || (is_Java_thread() || is_Worker_thread()),
 477             "Only Java and GC worker threads are allowed to get GCLABs");
 478     return _gclab;
 479   }
 480 
 481   void set_worker_id(uint id)           { _worker_id = id; }
 482   uint worker_id()                      { return _worker_id; }
 483 
 484   void set_force_satb_flush(bool value) { _force_satb_flush = value; }
 485   bool is_force_satb_flush()            { return _force_satb_flush; }
 486 
 487   void add_paced_time(double v)         { _paced_time += v; }
 488   double paced_time()                   { return _paced_time; }
 489   void reset_paced_time()               { _paced_time = 0; }
 490 
 491   jlong allocated_bytes()               { return _allocated_bytes; }
 492   void set_allocated_bytes(jlong value) { _allocated_bytes = value; }
 493   void incr_allocated_bytes(jlong size) { _allocated_bytes += size; }
 494   inline jlong cooked_allocated_bytes();
 495 
 496   jlong allocated_bytes_gclab()                { return _allocated_bytes_gclab; }
 497   void set_allocated_bytes_gclab(jlong value)  { _allocated_bytes_gclab = value; }
 498   void incr_allocated_bytes_gclab(jlong size)  { _allocated_bytes_gclab += size; }
 499 
 500   JFR_ONLY(DEFINE_THREAD_LOCAL_ACCESSOR_JFR;)
 501   JFR_ONLY(DEFINE_TRACE_SUSPEND_FLAG_METHODS)
 502 
 503   const ThreadExt& ext() const          { return _ext; }
 504   ThreadExt& ext()                      { return _ext; }
 505 
 506   // VM operation support
 507   int vm_operation_ticket()                      { return ++_vm_operation_started_count; }
 508   int vm_operation_completed_count()             { return _vm_operation_completed_count; }
 509   void increment_vm_operation_completed_count()  { _vm_operation_completed_count++; }
 510 
 511   // For tracking the heavyweight monitor the thread is pending on.
 512   ObjectMonitor* current_pending_monitor() {
 513     return _current_pending_monitor;
 514   }
 515   void set_current_pending_monitor(ObjectMonitor* monitor) {
 516     _current_pending_monitor = monitor;
 517   }
 518   void set_current_pending_monitor_is_from_java(bool from_java) {
 519     _current_pending_monitor_is_from_java = from_java;
 520   }
 521   bool current_pending_monitor_is_from_java() {
 522     return _current_pending_monitor_is_from_java;
 523   }
 524 
 525   // For tracking the ObjectMonitor on which this thread called Object.wait()
 526   ObjectMonitor* current_waiting_monitor() {
 527     return _current_waiting_monitor;
 528   }
 529   void set_current_waiting_monitor(ObjectMonitor* monitor) {
 530     _current_waiting_monitor = monitor;
 531   }
 532 
 533   // GC support
 534   // Apply "f->do_oop" to all root oops in "this".
 535   // Apply "cld_f->do_cld" to CLDs that are otherwise not kept alive.
 536   //   Used by JavaThread::oops_do.
 537   // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames
 538   virtual void oops_do(OopClosure* f, CLDClosure* cld_f, CodeBlobClosure* cf);
 539 
 540   // Handles the parallel case for the method below.
 541 private:
 542   bool claim_oops_do_par_case(int collection_parity);
 543 public:
 544   // Requires that "collection_parity" is that of the current roots
 545   // iteration.  If "is_par" is false, sets the parity of "this" to
 546   // "collection_parity", and returns "true".  If "is_par" is true,
 547   // uses an atomic instruction to set the current threads parity to
 548   // "collection_parity", if it is not already.  Returns "true" iff the
 549   // calling thread does the update, this indicates that the calling thread
 550   // has claimed the thread's stack as a root groop in the current
 551   // collection.
 552   bool claim_oops_do(bool is_par, int collection_parity) {
 553     if (!is_par) {
 554       _oops_do_parity = collection_parity;
 555       return true;
 556     } else {
 557       return claim_oops_do_par_case(collection_parity);
 558     }
 559   }
 560 
 561   // Sweeper support
 562   void nmethods_do(CodeBlobClosure* cf);
 563 
 564   // jvmtiRedefineClasses support
 565   void metadata_do(void f(Metadata*));
 566 
 567   // Used by fast lock support
 568   virtual bool is_lock_owned(address adr) const;
 569 
 570   // Check if address is in the stack of the thread (not just for locks).
 571   // Warning: the method can only be used on the running thread
 572   bool is_in_stack(address adr) const;
 573   // Check if address is in the usable part of the stack (excludes protected
 574   // guard pages)
 575   bool is_in_usable_stack(address adr) const;
 576 
 577   // Sets this thread as starting thread. Returns failure if thread
 578   // creation fails due to lack of memory, too many threads etc.
 579   bool set_as_starting_thread();
 580 
 581   void set_metadata_on_stack_buffer(MetadataOnStackBuffer* buffer) { _metadata_on_stack_buffer = buffer; }
 582   MetadataOnStackBuffer* metadata_on_stack_buffer() const          { return _metadata_on_stack_buffer; }
 583 
 584 protected:
 585   // OS data associated with the thread
 586   OSThread* _osthread;  // Platform-specific thread information
 587 
 588   // Thread local resource area for temporary allocation within the VM
 589   ResourceArea* _resource_area;
 590 
 591   DEBUG_ONLY(ResourceMark* _current_resource_mark;)
 592 
 593   // Thread local handle area for allocation of handles within the VM
 594   HandleArea* _handle_area;
 595   GrowableArray<Metadata*>* _metadata_handles;
 596 
 597   // Support for stack overflow handling, get_thread, etc.
 598   address          _stack_base;
 599   size_t           _stack_size;
 600   uintptr_t        _self_raw_id;      // used by get_thread (mutable)
 601   int              _lgrp_id;
 602 
 603  public:
 604   // Stack overflow support
 605   address stack_base() const           { assert(_stack_base != NULL,"Sanity check"); return _stack_base; }
 606 
 607   void    set_stack_base(address base) { _stack_base = base; }
 608   size_t  stack_size() const           { return _stack_size; }
 609   void    set_stack_size(size_t size)  { _stack_size = size; }
 610   void    record_stack_base_and_size();
 611 
 612   bool    on_local_stack(address adr) const {
 613     /* QQQ this has knowledge of direction, ought to be a stack method */
 614     return (_stack_base > adr && adr >= (_stack_base - _stack_size));
 615   }
 616 
 617   uintptr_t self_raw_id()                    { return _self_raw_id; }
 618   void      set_self_raw_id(uintptr_t value) { _self_raw_id = value; }
 619 
 620   int     lgrp_id() const        { return _lgrp_id; }
 621   void    set_lgrp_id(int value) { _lgrp_id = value; }
 622 
 623   // Printing
 624   void print_on(outputStream* st) const;
 625   void print() const { print_on(tty); }
 626   virtual void print_on_error(outputStream* st, char* buf, int buflen) const;
 627 
 628   // Debug-only code
 629 #ifdef ASSERT
 630  private:
 631   // Deadlock detection support for Mutex locks. List of locks own by thread.
 632   Monitor* _owned_locks;
 633   // Mutex::set_owner_implementation is the only place where _owned_locks is modified,
 634   // thus the friendship
 635   friend class Mutex;
 636   friend class Monitor;
 637 
 638  public:
 639   void print_owned_locks_on(outputStream* st) const;
 640   void print_owned_locks() const                 { print_owned_locks_on(tty);    }
 641   Monitor* owned_locks() const                   { return _owned_locks;          }
 642   bool owns_locks() const                        { return owned_locks() != NULL; }
 643   bool owns_locks_but_compiled_lock() const;
 644 
 645   // Deadlock detection
 646   bool allow_allocation()                        { return _allow_allocation_count == 0; }
 647   ResourceMark* current_resource_mark()          { return _current_resource_mark; }
 648   void set_current_resource_mark(ResourceMark* rm) { _current_resource_mark = rm; }
 649 #endif
 650 
 651   void check_for_valid_safepoint_state(bool potential_vm_operation) PRODUCT_RETURN;
 652 
 653  private:
 654   volatile int _jvmti_env_iteration_count;
 655 
 656  public:
 657   void entering_jvmti_env_iteration()            { ++_jvmti_env_iteration_count; }
 658   void leaving_jvmti_env_iteration()             { --_jvmti_env_iteration_count; }
 659   bool is_inside_jvmti_env_iteration()           { return _jvmti_env_iteration_count > 0; }
 660 
 661   // Code generation
 662   static ByteSize exception_file_offset()        { return byte_offset_of(Thread, _exception_file   ); }
 663   static ByteSize exception_line_offset()        { return byte_offset_of(Thread, _exception_line   ); }
 664   static ByteSize active_handles_offset()        { return byte_offset_of(Thread, _active_handles   ); }
 665 
 666   static ByteSize stack_base_offset()            { return byte_offset_of(Thread, _stack_base ); }
 667   static ByteSize stack_size_offset()            { return byte_offset_of(Thread, _stack_size ); }
 668 
 669 #define TLAB_FIELD_OFFSET(name) \
 670   static ByteSize tlab_##name##_offset()         { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::name##_offset(); }
 671 
 672   TLAB_FIELD_OFFSET(start)
 673   TLAB_FIELD_OFFSET(end)
 674   TLAB_FIELD_OFFSET(top)
 675   TLAB_FIELD_OFFSET(pf_top)
 676   TLAB_FIELD_OFFSET(size)                   // desired_size
 677   TLAB_FIELD_OFFSET(refill_waste_limit)
 678   TLAB_FIELD_OFFSET(number_of_refills)
 679   TLAB_FIELD_OFFSET(fast_refill_waste)
 680   TLAB_FIELD_OFFSET(slow_allocations)
 681 
 682 #undef TLAB_FIELD_OFFSET
 683 
 684   static ByteSize gclab_start_offset()         { return byte_offset_of(Thread, _gclab) + ThreadLocalAllocBuffer::start_offset(); }
 685   static ByteSize gclab_top_offset()           { return byte_offset_of(Thread, _gclab) + ThreadLocalAllocBuffer::top_offset(); }
 686   static ByteSize gclab_end_offset()           { return byte_offset_of(Thread, _gclab) + ThreadLocalAllocBuffer::end_offset(); }
 687 
 688   static ByteSize allocated_bytes_offset()       { return byte_offset_of(Thread, _allocated_bytes ); }
 689 
 690   JFR_ONLY(DEFINE_THREAD_LOCAL_OFFSET_JFR;)
 691 
 692  public:
 693   volatile intptr_t _Stalled ;
 694   volatile int _TypeTag ;
 695   ParkEvent * _ParkEvent ;                     // for synchronized()
 696   ParkEvent * _SleepEvent ;                    // for Thread.sleep
 697   ParkEvent * _MutexEvent ;                    // for native internal Mutex/Monitor
 698   ParkEvent * _MuxEvent ;                      // for low-level muxAcquire-muxRelease
 699   int NativeSyncRecursion ;                    // diagnostic
 700 
 701   volatile int _OnTrap ;                       // Resume-at IP delta
 702   jint _hashStateW ;                           // Marsaglia Shift-XOR thread-local RNG
 703   jint _hashStateX ;                           // thread-specific hashCode generator state
 704   jint _hashStateY ;
 705   jint _hashStateZ ;
 706   void * _schedctl ;
 707 
 708 
 709   volatile jint rng [4] ;                      // RNG for spin loop
 710 
 711   // Low-level leaf-lock primitives used to implement synchronization
 712   // and native monitor-mutex infrastructure.
 713   // Not for general synchronization use.
 714   static void SpinAcquire (volatile int * Lock, const char * Name) ;
 715   static void SpinRelease (volatile int * Lock) ;
 716   static void muxAcquire  (volatile intptr_t * Lock, const char * Name) ;
 717   static void muxAcquireW (volatile intptr_t * Lock, ParkEvent * ev) ;
 718   static void muxRelease  (volatile intptr_t * Lock) ;
 719 };
 720 
 721 // Inline implementation of Thread::current()
 722 // Thread::current is "hot" it's called > 128K times in the 1st 500 msecs of
 723 // startup.
 724 // ThreadLocalStorage::thread is warm -- it's called > 16K times in the same
 725 // period.   This is inlined in thread_<os_family>.inline.hpp.
 726 
 727 inline Thread* Thread::current() {
 728 #ifdef ASSERT
 729 // This function is very high traffic. Define PARANOID to enable expensive
 730 // asserts.
 731 #ifdef PARANOID
 732   // Signal handler should call ThreadLocalStorage::get_thread_slow()
 733   Thread* t = ThreadLocalStorage::get_thread_slow();
 734   assert(t != NULL && !t->is_inside_signal_handler(),
 735          "Don't use Thread::current() inside signal handler");
 736 #endif
 737 #endif
 738   Thread* current = current_or_null();
 739   assert(current != NULL, "Thread::current() called on detached thread");
 740   return current;
 741 }
 742 
 743 inline Thread* Thread::current_or_null() {
 744   if (ThreadLocalStorage::is_initialized()) {
 745     return ThreadLocalStorage::thread();
 746   }
 747   return NULL;
 748 }
 749 
 750 // Name support for threads.  non-JavaThread subclasses with multiple
 751 // uniquely named instances should derive from this.
 752 class NamedThread: public Thread {
 753   friend class VMStructs;
 754   enum {
 755     max_name_len = 64
 756   };
 757  private:
 758   char* _name;
 759   // log JavaThread being processed by oops_do
 760   JavaThread* _processed_thread;
 761 
 762  public:
 763   NamedThread();
 764   ~NamedThread();
 765   // May only be called once per thread.
 766   void set_name(const char* format, ...)  ATTRIBUTE_PRINTF(2, 3);
 767   virtual bool is_Named_thread() const { return true; }
 768   virtual char* name() const { return _name == NULL ? (char*)"Unknown Thread" : _name; }
 769   JavaThread *processed_thread() { return _processed_thread; }
 770   void set_processed_thread(JavaThread *thread) { _processed_thread = thread; }
 771 };
 772 
 773 // Worker threads are named and have an id of an assigned work.
 774 class WorkerThread: public NamedThread {
 775 private:
 776   uint _id;
 777 public:
 778   WorkerThread() : _id(0)               { }
 779   virtual bool is_Worker_thread() const { return true; }
 780 
 781   virtual WorkerThread* as_Worker_thread() const {
 782     assert(is_Worker_thread(), "Dubious cast to WorkerThread*?");
 783     return (WorkerThread*) this;
 784   }
 785 
 786   void set_id(uint work_id)             { _id = work_id; }
 787   uint id() const                       { return _id; }
 788 };
 789 
 790 // A single WatcherThread is used for simulating timer interrupts.
 791 class WatcherThread: public Thread {
 792   friend class VMStructs;
 793  public:
 794   virtual void run();
 795 
 796  private:
 797   static WatcherThread* _watcher_thread;
 798 
 799   static bool _startable;
 800   volatile static bool _should_terminate; // updated without holding lock
 801  public:
 802   enum SomeConstants {
 803     delay_interval = 10                          // interrupt delay in milliseconds
 804   };
 805 
 806   // Constructor
 807   WatcherThread();
 808 
 809   // Tester
 810   bool is_Watcher_thread() const                 { return true; }
 811 
 812   // Printing
 813   char* name() const { return (char*)"VM Periodic Task Thread"; }
 814   void print_on(outputStream* st) const;
 815   void print() const { print_on(tty); }
 816   void unpark();
 817 
 818   // Returns the single instance of WatcherThread
 819   static WatcherThread* watcher_thread()         { return _watcher_thread; }
 820 
 821   // Create and start the single instance of WatcherThread, or stop it on shutdown
 822   static void start();
 823   static void stop();
 824   // Only allow start once the VM is sufficiently initialized
 825   // Otherwise the first task to enroll will trigger the start
 826   static void make_startable();
 827  private:
 828   int sleep() const;
 829 };
 830 
 831 
 832 class CompilerThread;
 833 
 834 typedef void (*ThreadFunction)(JavaThread*, TRAPS);
 835 
 836 class JavaThread: public Thread {
 837   friend class VMStructs;
 838  private:
 839   JavaThread*    _next;                          // The next thread in the Threads list
 840   oop            _threadObj;                     // The Java level thread object
 841 
 842 #ifdef ASSERT
 843  private:
 844   int _java_call_counter;
 845 
 846  public:
 847   int  java_call_counter()                       { return _java_call_counter; }
 848   void inc_java_call_counter()                   { _java_call_counter++; }
 849   void dec_java_call_counter() {
 850     assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
 851     _java_call_counter--;
 852   }
 853  private:  // restore original namespace restriction
 854 #endif  // ifdef ASSERT
 855 
 856 #ifndef PRODUCT
 857  public:
 858   enum {
 859     jump_ring_buffer_size = 16
 860   };
 861  private:  // restore original namespace restriction
 862 #endif
 863 
 864   JavaFrameAnchor _anchor;                       // Encapsulation of current java frame and it state
 865 
 866   ThreadFunction _entry_point;
 867 
 868   JNIEnv        _jni_environment;
 869 
 870   // Deopt support
 871   DeoptResourceMark*  _deopt_mark;               // Holds special ResourceMark for deoptimization
 872 
 873   intptr_t*      _must_deopt_id;                 // id of frame that needs to be deopted once we
 874                                                  // transition out of native
 875   nmethod*       _deopt_nmethod;                 // nmethod that is currently being deoptimized
 876   vframeArray*  _vframe_array_head;              // Holds the heap of the active vframeArrays
 877   vframeArray*  _vframe_array_last;              // Holds last vFrameArray we popped
 878   // Because deoptimization is lazy we must save jvmti requests to set locals
 879   // in compiled frames until we deoptimize and we have an interpreter frame.
 880   // This holds the pointer to array (yeah like there might be more than one) of
 881   // description of compiled vframes that have locals that need to be updated.
 882   GrowableArray<jvmtiDeferredLocalVariableSet*>* _deferred_locals_updates;
 883 
 884   // Handshake value for fixing 6243940. We need a place for the i2c
 885   // adapter to store the callee Method*. This value is NEVER live
 886   // across a gc point so it does NOT have to be gc'd
 887   // The handshake is open ended since we can't be certain that it will
 888   // be NULLed. This is because we rarely ever see the race and end up
 889   // in handle_wrong_method which is the backend of the handshake. See
 890   // code in i2c adapters and handle_wrong_method.
 891 
 892   Method*       _callee_target;
 893 
 894   // Used to pass back results to the interpreter or generated code running Java code.
 895   oop           _vm_result;    // oop result is GC-preserved
 896   Metadata*     _vm_result_2;  // non-oop result
 897 
 898   // See ReduceInitialCardMarks: this holds the precise space interval of
 899   // the most recent slow path allocation for which compiled code has
 900   // elided card-marks for performance along the fast-path.
 901   MemRegion     _deferred_card_mark;
 902 
 903   MonitorChunk* _monitor_chunks;                 // Contains the off stack monitors
 904                                                  // allocated during deoptimization
 905                                                  // and by JNI_MonitorEnter/Exit
 906 
 907   // Async. requests support
 908   enum AsyncRequests {
 909     _no_async_condition = 0,
 910     _async_exception,
 911     _async_unsafe_access_error
 912   };
 913   AsyncRequests _special_runtime_exit_condition; // Enum indicating pending async. request
 914   oop           _pending_async_exception;
 915 
 916   // Safepoint support
 917  public:                                         // Expose _thread_state for SafeFetchInt()
 918   volatile JavaThreadState _thread_state;
 919  private:
 920   ThreadSafepointState *_safepoint_state;        // Holds information about a thread during a safepoint
 921   address               _saved_exception_pc;     // Saved pc of instruction where last implicit exception happened
 922 
 923   // JavaThread termination support
 924   enum TerminatedTypes {
 925     _not_terminated = 0xDEAD - 2,
 926     _thread_exiting,                             // JavaThread::exit() has been called for this thread
 927     _thread_terminated,                          // JavaThread is removed from thread list
 928     _vm_exited                                   // JavaThread is still executing native code, but VM is terminated
 929                                                  // only VM_Exit can set _vm_exited
 930   };
 931 
 932   // In general a JavaThread's _terminated field transitions as follows:
 933   //
 934   //   _not_terminated => _thread_exiting => _thread_terminated
 935   //
 936   // _vm_exited is a special value to cover the case of a JavaThread
 937   // executing native code after the VM itself is terminated.
 938   volatile TerminatedTypes _terminated;
 939   // suspend/resume support
 940   volatile bool         _suspend_equivalent;     // Suspend equivalent condition
 941   jint                  _in_deopt_handler;       // count of deoptimization
 942                                                  // handlers thread is in
 943   volatile bool         _doing_unsafe_access;    // Thread may fault due to unsafe access
 944   bool                  _do_not_unlock_if_synchronized; // Do not unlock the receiver of a synchronized method (since it was
 945                                                  // never locked) when throwing an exception. Used by interpreter only.
 946 
 947   // JNI attach states:
 948   enum JNIAttachStates {
 949     _not_attaching_via_jni = 1,  // thread is not attaching via JNI
 950     _attaching_via_jni,          // thread is attaching via JNI
 951     _attached_via_jni            // thread has attached via JNI
 952   };
 953 
 954   // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
 955   // A native thread that is attaching via JNI starts with a value
 956   // of _attaching_via_jni and transitions to _attached_via_jni.
 957   volatile JNIAttachStates _jni_attach_state;
 958 
 959  public:
 960   // State of the stack guard pages for this thread.
 961   enum StackGuardState {
 962     stack_guard_unused,         // not needed
 963     stack_guard_yellow_disabled,// disabled (temporarily) after stack overflow
 964     stack_guard_enabled         // enabled
 965   };
 966 
 967  private:
 968 
 969   StackGuardState  _stack_guard_state;
 970 
 971   // Precompute the limit of the stack as used in stack overflow checks.
 972   // We load it from here to simplify the stack overflow check in assembly.
 973   address          _stack_overflow_limit;
 974 
 975   // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
 976   // used to temp. parsing values into and out of the runtime system during exception handling for compiled
 977   // code)
 978   volatile oop     _exception_oop;               // Exception thrown in compiled code
 979   volatile address _exception_pc;                // PC where exception happened
 980   volatile address _exception_handler_pc;        // PC for handler of exception
 981   volatile int     _is_method_handle_return;     // true (== 1) if the current exception PC is a MethodHandle call site.
 982 
 983   // support for JNI critical regions
 984   jint    _jni_active_critical;                  // count of entries into JNI critical region
 985 
 986   // Checked JNI: function name requires exception check
 987   char* _pending_jni_exception_check_fn;
 988 
 989   // For deadlock detection.
 990   int _depth_first_number;
 991 
 992   // JVMTI PopFrame support
 993   // This is set to popframe_pending to signal that top Java frame should be popped immediately
 994   int _popframe_condition;
 995 
 996   // If reallocation of scalar replaced objects fails, we throw OOM
 997   // and during exception propagation, pop the top
 998   // _frames_to_pop_failed_realloc frames, the ones that reference
 999   // failed reallocations.
1000   int _frames_to_pop_failed_realloc;
1001 
1002 #ifndef PRODUCT
1003   int _jmp_ring_index;
1004   struct {
1005       // We use intptr_t instead of address so debugger doesn't try and display strings
1006       intptr_t _target;
1007       intptr_t _instruction;
1008       const char*  _file;
1009       int _line;
1010   }   _jmp_ring[ jump_ring_buffer_size ];
1011 #endif /* PRODUCT */
1012 
1013 #if INCLUDE_ALL_GCS
1014   // Support for G1 barriers
1015 
1016   ObjPtrQueue _satb_mark_queue;          // Thread-local log for SATB barrier.
1017   // Set of all such queues.
1018   static SATBMarkQueueSet _satb_mark_queue_set;
1019 
1020   DirtyCardQueue _dirty_card_queue;      // Thread-local log for dirty cards.
1021   // Set of all such queues.
1022   static DirtyCardQueueSet _dirty_card_queue_set;
1023 
1024   void flush_barrier_queues();
1025 #endif // INCLUDE_ALL_GCS
1026 
1027   friend class VMThread;
1028   friend class ThreadWaitTransition;
1029   friend class VM_Exit;
1030 
1031   void initialize();                             // Initialized the instance variables
1032 
1033  public:
1034   // Constructor
1035   JavaThread(bool is_attaching_via_jni = false); // for main thread and JNI attached threads
1036   JavaThread(ThreadFunction entry_point, size_t stack_size = 0);
1037   ~JavaThread();
1038 
1039 #ifdef ASSERT
1040   // verify this JavaThread hasn't be published in the Threads::list yet
1041   void verify_not_published();
1042 #endif
1043 
1044   //JNI functiontable getter/setter for JVMTI jni function table interception API.
1045   void set_jni_functions(struct JNINativeInterface_* functionTable) {
1046     _jni_environment.functions = functionTable;
1047   }
1048   struct JNINativeInterface_* get_jni_functions() {
1049     return (struct JNINativeInterface_ *)_jni_environment.functions;
1050   }
1051 
1052   // This function is called at thread creation to allow
1053   // platform specific thread variables to be initialized.
1054   void cache_global_variables();
1055 
1056   // Executes Shutdown.shutdown()
1057   void invoke_shutdown_hooks();
1058 
1059   // Cleanup on thread exit
1060   enum ExitType {
1061     normal_exit,
1062     jni_detach
1063   };
1064   void exit(bool destroy_vm, ExitType exit_type = normal_exit);
1065 
1066   void cleanup_failed_attach_current_thread();
1067 
1068   // Testers
1069   virtual bool is_Java_thread() const            { return true;  }
1070 
1071   // Thread chain operations
1072   JavaThread* next() const                       { return _next; }
1073   void set_next(JavaThread* p)                   { _next = p; }
1074 
1075   // Thread oop. threadObj() can be NULL for initial JavaThread
1076   // (or for threads attached via JNI)
1077   oop threadObj() const                          { return _threadObj; }
1078   void set_threadObj(oop p)                      { _threadObj = p; }
1079 
1080   ThreadPriority java_priority() const;          // Read from threadObj()
1081 
1082   // Prepare thread and add to priority queue.  If a priority is
1083   // not specified, use the priority of the thread object. Threads_lock
1084   // must be held while this function is called.
1085   void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
1086   void prepare_ext();
1087 
1088   void set_saved_exception_pc(address pc)        { _saved_exception_pc = pc; }
1089   address saved_exception_pc()                   { return _saved_exception_pc; }
1090 
1091 
1092   ThreadFunction entry_point() const             { return _entry_point; }
1093 
1094   // Allocates a new Java level thread object for this thread. thread_name may be NULL.
1095   void allocate_threadObj(Handle thread_group, char* thread_name, bool daemon, TRAPS);
1096 
1097   // Last frame anchor routines
1098 
1099   JavaFrameAnchor* frame_anchor(void)            { return &_anchor; }
1100 
1101   // last_Java_sp
1102   bool has_last_Java_frame() const               { return _anchor.has_last_Java_frame(); }
1103   intptr_t* last_Java_sp() const                 { return _anchor.last_Java_sp(); }
1104 
1105   // last_Java_pc
1106 
1107   address last_Java_pc(void)                     { return _anchor.last_Java_pc(); }
1108 
1109   // Safepoint support
1110 #if !(defined(PPC64) || defined(AARCH64))
1111   JavaThreadState thread_state() const           { return _thread_state; }
1112   void set_thread_state(JavaThreadState s)       { _thread_state = s;    }
1113 #else
1114   // Use membars when accessing volatile _thread_state. See
1115   // Threads::create_vm() for size checks.
1116   inline JavaThreadState thread_state() const;
1117   inline void set_thread_state(JavaThreadState s);
1118 #endif
1119   ThreadSafepointState *safepoint_state() const  { return _safepoint_state; }
1120   void set_safepoint_state(ThreadSafepointState *state) { _safepoint_state = state; }
1121   bool is_at_poll_safepoint()                    { return _safepoint_state->is_at_poll_safepoint(); }
1122 
1123   // thread has called JavaThread::exit() or is terminated
1124   bool is_exiting()                              { return _terminated == _thread_exiting || is_terminated(); }
1125   // thread is terminated (no longer on the threads list); we compare
1126   // against the two non-terminated values so that a freed JavaThread
1127   // will also be considered terminated.
1128   bool is_terminated()                           { return _terminated != _not_terminated && _terminated != _thread_exiting; }
1129   void set_terminated(TerminatedTypes t)         { _terminated = t; }
1130   // special for Threads::remove() which is static:
1131   void set_terminated_value()                    { _terminated = _thread_terminated; }
1132   void block_if_vm_exited();
1133 
1134   bool doing_unsafe_access()                     { return _doing_unsafe_access; }
1135   void set_doing_unsafe_access(bool val)         { _doing_unsafe_access = val; }
1136 
1137   bool do_not_unlock_if_synchronized()             { return _do_not_unlock_if_synchronized; }
1138   void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
1139 
1140   // Suspend/resume support for JavaThread
1141  private:
1142   void set_ext_suspended()       { set_suspend_flag (_ext_suspended);  }
1143   void clear_ext_suspended()     { clear_suspend_flag(_ext_suspended); }
1144 
1145  public:
1146   void java_suspend();
1147   void java_resume();
1148   int  java_suspend_self();
1149 
1150   void check_and_wait_while_suspended() {
1151     assert(JavaThread::current() == this, "sanity check");
1152 
1153     bool do_self_suspend;
1154     do {
1155       // were we externally suspended while we were waiting?
1156       do_self_suspend = handle_special_suspend_equivalent_condition();
1157       if (do_self_suspend) {
1158         // don't surprise the thread that suspended us by returning
1159         java_suspend_self();
1160         set_suspend_equivalent();
1161       }
1162     } while (do_self_suspend);
1163   }
1164   static void check_safepoint_and_suspend_for_native_trans(JavaThread *thread);
1165   // Check for async exception in addition to safepoint and suspend request.
1166   static void check_special_condition_for_native_trans(JavaThread *thread);
1167 
1168   // Same as check_special_condition_for_native_trans but finishes the
1169   // transition into thread_in_Java mode so that it can potentially
1170   // block.
1171   static void check_special_condition_for_native_trans_and_transition(JavaThread *thread);
1172 
1173   bool is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits);
1174   bool is_ext_suspend_completed_with_lock(uint32_t *bits) {
1175     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1176     // Warning: is_ext_suspend_completed() may temporarily drop the
1177     // SR_lock to allow the thread to reach a stable thread state if
1178     // it is currently in a transient thread state.
1179     return is_ext_suspend_completed(false /*!called_by_wait */,
1180                                     SuspendRetryDelay, bits);
1181   }
1182 
1183   // We cannot allow wait_for_ext_suspend_completion() to run forever or
1184   // we could hang. SuspendRetryCount and SuspendRetryDelay are normally
1185   // passed as the count and delay parameters. Experiments with specific
1186   // calls to wait_for_ext_suspend_completion() can be done by passing
1187   // other values in the code. Experiments with all calls can be done
1188   // via the appropriate -XX options.
1189   bool wait_for_ext_suspend_completion(int count, int delay, uint32_t *bits);
1190 
1191   void set_external_suspend()     { set_suspend_flag  (_external_suspend); }
1192   void clear_external_suspend()   { clear_suspend_flag(_external_suspend); }
1193 
1194   void set_deopt_suspend()        { set_suspend_flag  (_deopt_suspend); }
1195   void clear_deopt_suspend()      { clear_suspend_flag(_deopt_suspend); }
1196   bool is_deopt_suspend()         { return (_suspend_flags & _deopt_suspend) != 0; }
1197 
1198   bool is_external_suspend() const {
1199     return (_suspend_flags & _external_suspend) != 0;
1200   }
1201   // Whenever a thread transitions from native to vm/java it must suspend
1202   // if external|deopt suspend is present.
1203   bool is_suspend_after_native() const {
1204     return (_suspend_flags & (_external_suspend | _deopt_suspend) ) != 0;
1205   }
1206 
1207   // external suspend request is completed
1208   bool is_ext_suspended() const {
1209     return (_suspend_flags & _ext_suspended) != 0;
1210   }
1211 
1212   bool is_external_suspend_with_lock() const {
1213     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1214     return is_external_suspend();
1215   }
1216 
1217   // Special method to handle a pending external suspend request
1218   // when a suspend equivalent condition lifts.
1219   bool handle_special_suspend_equivalent_condition() {
1220     assert(is_suspend_equivalent(),
1221       "should only be called in a suspend equivalence condition");
1222     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1223     bool ret = is_external_suspend();
1224     if (!ret) {
1225       // not about to self-suspend so clear suspend equivalence
1226       clear_suspend_equivalent();
1227     }
1228     // implied else:
1229     // We have a pending external suspend request so we leave the
1230     // suspend_equivalent flag set until java_suspend_self() sets
1231     // the ext_suspended flag and clears the suspend_equivalent
1232     // flag. This insures that wait_for_ext_suspend_completion()
1233     // will return consistent values.
1234     return ret;
1235   }
1236 
1237   // utility methods to see if we are doing some kind of suspension
1238   bool is_being_ext_suspended() const            {
1239     MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1240     return is_ext_suspended() || is_external_suspend();
1241   }
1242 
1243   bool is_suspend_equivalent() const             { return _suspend_equivalent; }
1244 
1245   void set_suspend_equivalent()                  { _suspend_equivalent = true; };
1246   void clear_suspend_equivalent()                { _suspend_equivalent = false; };
1247 
1248   // Thread.stop support
1249   void send_thread_stop(oop throwable);
1250   AsyncRequests clear_special_runtime_exit_condition() {
1251     AsyncRequests x = _special_runtime_exit_condition;
1252     _special_runtime_exit_condition = _no_async_condition;
1253     return x;
1254   }
1255 
1256   // Are any async conditions present?
1257   bool has_async_condition() { return (_special_runtime_exit_condition != _no_async_condition); }
1258 
1259   void check_and_handle_async_exceptions(bool check_unsafe_error = true);
1260 
1261   // these next two are also used for self-suspension and async exception support
1262   void handle_special_runtime_exit_condition(bool check_asyncs = true);
1263 
1264   // Return true if JavaThread has an asynchronous condition or
1265   // if external suspension is requested.
1266   bool has_special_runtime_exit_condition() {
1267     // We call is_external_suspend() last since external suspend should
1268     // be less common. Because we don't use is_external_suspend_with_lock
1269     // it is possible that we won't see an asynchronous external suspend
1270     // request that has just gotten started, i.e., SR_lock grabbed but
1271     // _external_suspend field change either not made yet or not visible
1272     // yet. However, this is okay because the request is asynchronous and
1273     // we will see the new flag value the next time through. It's also
1274     // possible that the external suspend request is dropped after
1275     // we have checked is_external_suspend(), we will recheck its value
1276     // under SR_lock in java_suspend_self().
1277     return (_special_runtime_exit_condition != _no_async_condition) ||
1278             is_external_suspend() || is_deopt_suspend();
1279   }
1280 
1281   void set_pending_unsafe_access_error()          { _special_runtime_exit_condition = _async_unsafe_access_error; }
1282 
1283   void set_pending_async_exception(oop e) {
1284     _pending_async_exception = e;
1285     _special_runtime_exit_condition = _async_exception;
1286     set_has_async_exception();
1287   }
1288 
1289   // Fast-locking support
1290   bool is_lock_owned(address adr) const;
1291 
1292   // Accessors for vframe array top
1293   // The linked list of vframe arrays are sorted on sp. This means when we
1294   // unpack the head must contain the vframe array to unpack.
1295   void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
1296   vframeArray* vframe_array_head() const         { return _vframe_array_head;  }
1297 
1298   // Side structure for defering update of java frame locals until deopt occurs
1299   GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred_locals() const { return _deferred_locals_updates; }
1300   void set_deferred_locals(GrowableArray<jvmtiDeferredLocalVariableSet *>* vf) { _deferred_locals_updates = vf; }
1301 
1302   // These only really exist to make debugging deopt problems simpler
1303 
1304   void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
1305   vframeArray* vframe_array_last() const         { return _vframe_array_last;  }
1306 
1307   // The special resourceMark used during deoptimization
1308 
1309   void set_deopt_mark(DeoptResourceMark* value)  { _deopt_mark = value; }
1310   DeoptResourceMark* deopt_mark(void)            { return _deopt_mark; }
1311 
1312   intptr_t* must_deopt_id()                      { return _must_deopt_id; }
1313   void     set_must_deopt_id(intptr_t* id)       { _must_deopt_id = id; }
1314   void     clear_must_deopt_id()                 { _must_deopt_id = NULL; }
1315 
1316   void set_deopt_nmethod(nmethod* nm)            { _deopt_nmethod = nm;   }
1317   nmethod* deopt_nmethod()                       { return _deopt_nmethod; }
1318 
1319   Method*    callee_target() const               { return _callee_target; }
1320   void set_callee_target  (Method* x)          { _callee_target   = x; }
1321 
1322   // Oop results of vm runtime calls
1323   oop  vm_result() const                         { return _vm_result; }
1324   void set_vm_result  (oop x)                    { _vm_result   = x; }
1325 
1326   Metadata*    vm_result_2() const               { return _vm_result_2; }
1327   void set_vm_result_2  (Metadata* x)          { _vm_result_2   = x; }
1328 
1329   MemRegion deferred_card_mark() const           { return _deferred_card_mark; }
1330   void set_deferred_card_mark(MemRegion mr)      { _deferred_card_mark = mr;   }
1331 
1332   // Exception handling for compiled methods
1333   oop      exception_oop() const                 { return _exception_oop; }
1334   address  exception_pc() const                  { return _exception_pc; }
1335   address  exception_handler_pc() const          { return _exception_handler_pc; }
1336   bool     is_method_handle_return() const       { return _is_method_handle_return == 1; }
1337 
1338   void set_exception_oop(oop o)                  { (void)const_cast<oop&>(_exception_oop = o); }
1339   void set_exception_pc(address a)               { _exception_pc = a; }
1340   void set_exception_handler_pc(address a)       { _exception_handler_pc = a; }
1341   void set_is_method_handle_return(bool value)   { _is_method_handle_return = value ? 1 : 0; }
1342 
1343   void clear_exception_oop_and_pc() {
1344     set_exception_oop(NULL);
1345     set_exception_pc(NULL);
1346   }
1347 
1348   // Stack overflow support
1349   inline size_t stack_available(address cur_sp);
1350   address stack_yellow_zone_base()
1351     { return (address)(stack_base() - (stack_size() - (stack_red_zone_size() + stack_yellow_zone_size()))); }
1352   size_t  stack_yellow_zone_size()
1353     { return StackYellowPages * os::vm_page_size(); }
1354   address stack_red_zone_base()
1355     { return (address)(stack_base() - (stack_size() - stack_red_zone_size())); }
1356   size_t stack_red_zone_size()
1357     { return StackRedPages * os::vm_page_size(); }
1358   bool in_stack_yellow_zone(address a)
1359     { return (a <= stack_yellow_zone_base()) && (a >= stack_red_zone_base()); }
1360   bool in_stack_red_zone(address a)
1361     { return (a <= stack_red_zone_base()) && (a >= (address)((intptr_t)stack_base() - stack_size())); }
1362 
1363   void create_stack_guard_pages();
1364   void remove_stack_guard_pages();
1365 
1366   void enable_stack_yellow_zone();
1367   void disable_stack_yellow_zone();
1368   void enable_stack_red_zone();
1369   void disable_stack_red_zone();
1370 
1371   inline bool stack_guard_zone_unused();
1372   inline bool stack_yellow_zone_disabled();
1373   inline bool stack_yellow_zone_enabled();
1374 
1375   // Attempt to reguard the stack after a stack overflow may have occurred.
1376   // Returns true if (a) guard pages are not needed on this thread, (b) the
1377   // pages are already guarded, or (c) the pages were successfully reguarded.
1378   // Returns false if there is not enough stack space to reguard the pages, in
1379   // which case the caller should unwind a frame and try again.  The argument
1380   // should be the caller's (approximate) sp.
1381   bool reguard_stack(address cur_sp);
1382   // Similar to above but see if current stackpoint is out of the guard area
1383   // and reguard if possible.
1384   bool reguard_stack(void);
1385 
1386   address stack_overflow_limit() { return _stack_overflow_limit; }
1387   void set_stack_overflow_limit() {
1388     _stack_overflow_limit = _stack_base - _stack_size +
1389                             ((StackShadowPages +
1390                               StackYellowPages +
1391                               StackRedPages) * os::vm_page_size());
1392   }
1393 
1394   // Misc. accessors/mutators
1395   void set_do_not_unlock(void)                   { _do_not_unlock_if_synchronized = true; }
1396   void clr_do_not_unlock(void)                   { _do_not_unlock_if_synchronized = false; }
1397   bool do_not_unlock(void)                       { return _do_not_unlock_if_synchronized; }
1398 
1399 #ifndef PRODUCT
1400   void record_jump(address target, address instr, const char* file, int line);
1401 #endif /* PRODUCT */
1402 
1403   // For assembly stub generation
1404   static ByteSize threadObj_offset()             { return byte_offset_of(JavaThread, _threadObj           ); }
1405 #ifndef PRODUCT
1406   static ByteSize jmp_ring_index_offset()        { return byte_offset_of(JavaThread, _jmp_ring_index      ); }
1407   static ByteSize jmp_ring_offset()              { return byte_offset_of(JavaThread, _jmp_ring            ); }
1408 #endif /* PRODUCT */
1409   static ByteSize jni_environment_offset()       { return byte_offset_of(JavaThread, _jni_environment     ); }
1410   static ByteSize last_Java_sp_offset()          {
1411     return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
1412   }
1413   static ByteSize last_Java_pc_offset()          {
1414     return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
1415   }
1416   static ByteSize frame_anchor_offset()          {
1417     return byte_offset_of(JavaThread, _anchor);
1418   }
1419   static ByteSize callee_target_offset()         { return byte_offset_of(JavaThread, _callee_target       ); }
1420   static ByteSize vm_result_offset()             { return byte_offset_of(JavaThread, _vm_result           ); }
1421   static ByteSize vm_result_2_offset()           { return byte_offset_of(JavaThread, _vm_result_2         ); }
1422   static ByteSize thread_state_offset()          { return byte_offset_of(JavaThread, _thread_state        ); }
1423   static ByteSize saved_exception_pc_offset()    { return byte_offset_of(JavaThread, _saved_exception_pc  ); }
1424   static ByteSize osthread_offset()              { return byte_offset_of(JavaThread, _osthread            ); }
1425   static ByteSize exception_oop_offset()         { return byte_offset_of(JavaThread, _exception_oop       ); }
1426   static ByteSize exception_pc_offset()          { return byte_offset_of(JavaThread, _exception_pc        ); }
1427   static ByteSize exception_handler_pc_offset()  { return byte_offset_of(JavaThread, _exception_handler_pc); }
1428   static ByteSize stack_overflow_limit_offset()  { return byte_offset_of(JavaThread, _stack_overflow_limit); }
1429   static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); }
1430   static ByteSize stack_guard_state_offset()     { return byte_offset_of(JavaThread, _stack_guard_state   ); }
1431   static ByteSize suspend_flags_offset()         { return byte_offset_of(JavaThread, _suspend_flags       ); }
1432 
1433   static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
1434   static ByteSize should_post_on_exceptions_flag_offset() {
1435     return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
1436   }
1437 
1438 #if INCLUDE_ALL_GCS
1439   static ByteSize satb_mark_queue_offset()       { return byte_offset_of(JavaThread, _satb_mark_queue); }
1440   static ByteSize dirty_card_queue_offset()      { return byte_offset_of(JavaThread, _dirty_card_queue); }
1441 
1442   static ByteSize gc_state_offset()              { return byte_offset_of(JavaThread, _gc_state); }
1443 
1444 #endif // INCLUDE_ALL_GCS
1445 
1446   // Returns the jni environment for this thread
1447   JNIEnv* jni_environment()                      { return &_jni_environment; }
1448 
1449   static JavaThread* thread_from_jni_environment(JNIEnv* env) {
1450     JavaThread *thread_from_jni_env = (JavaThread*)((intptr_t)env - in_bytes(jni_environment_offset()));
1451     // Only return NULL if thread is off the thread list; starting to
1452     // exit should not return NULL.
1453     if (thread_from_jni_env->is_terminated()) {
1454        thread_from_jni_env->block_if_vm_exited();
1455        return NULL;
1456     } else {
1457        return thread_from_jni_env;
1458     }
1459   }
1460 
1461   // JNI critical regions. These can nest.
1462   bool in_critical()    { return _jni_active_critical > 0; }
1463   bool in_last_critical()  { return _jni_active_critical == 1; }
1464   void enter_critical() { assert(Thread::current() == this ||
1465                                  Thread::current()->is_VM_thread() && SafepointSynchronize::is_synchronizing(),
1466                                  "this must be current thread or synchronizing");
1467                           _jni_active_critical++; }
1468   void exit_critical()  { assert(Thread::current() == this,
1469                                  "this must be current thread");
1470                           _jni_active_critical--;
1471                           assert(_jni_active_critical >= 0,
1472                                  "JNI critical nesting problem?"); }
1473 
1474   // Checked JNI, is the programmer required to check for exceptions, specify which function name
1475   bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != NULL; }
1476   void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = NULL; }
1477   const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; }
1478   void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; }
1479 
1480   // For deadlock detection
1481   int depth_first_number() { return _depth_first_number; }
1482   void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
1483 
1484  private:
1485   void set_monitor_chunks(MonitorChunk* monitor_chunks) { _monitor_chunks = monitor_chunks; }
1486 
1487  public:
1488   MonitorChunk* monitor_chunks() const           { return _monitor_chunks; }
1489   void add_monitor_chunk(MonitorChunk* chunk);
1490   void remove_monitor_chunk(MonitorChunk* chunk);
1491   bool in_deopt_handler() const                  { return _in_deopt_handler > 0; }
1492   void inc_in_deopt_handler()                    { _in_deopt_handler++; }
1493   void dec_in_deopt_handler()                    {
1494     assert(_in_deopt_handler > 0, "mismatched deopt nesting");
1495     if (_in_deopt_handler > 0) { // robustness
1496       _in_deopt_handler--;
1497     }
1498   }
1499 
1500  private:
1501   void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
1502 
1503  public:
1504 
1505   // Frame iteration; calls the function f for all frames on the stack
1506   void frames_do(void f(frame*, const RegisterMap*));
1507 
1508   // Memory operations
1509   void oops_do(OopClosure* f, CLDClosure* cld_f, CodeBlobClosure* cf);
1510 
1511   // Sweeper operations
1512   void nmethods_do(CodeBlobClosure* cf);
1513 
1514   // RedefineClasses Support
1515   void metadata_do(void f(Metadata*));
1516 
1517   // Memory management operations
1518   void gc_epilogue();
1519   void gc_prologue();
1520 
1521   // Misc. operations
1522   char* name() const { return (char*)get_thread_name(); }
1523   void print_on(outputStream* st) const;
1524   void print() const { print_on(tty); }
1525   void print_value();
1526   void print_thread_state_on(outputStream* ) const      PRODUCT_RETURN;
1527   void print_thread_state() const                       PRODUCT_RETURN;
1528   void print_on_error(outputStream* st, char* buf, int buflen) const;
1529   void verify();
1530   const char* get_thread_name() const;
1531 private:
1532   // factor out low-level mechanics for use in both normal and error cases
1533   const char* get_thread_name_string(char* buf = NULL, int buflen = 0) const;
1534 public:
1535   const char* get_threadgroup_name() const;
1536   const char* get_parent_name() const;
1537 
1538   // Accessing frames
1539   frame last_frame() {
1540     _anchor.make_walkable(this);
1541     return pd_last_frame();
1542   }
1543   javaVFrame* last_java_vframe(RegisterMap* reg_map);
1544 
1545   // Returns method at 'depth' java or native frames down the stack
1546   // Used for security checks
1547   Klass* security_get_caller_class(int depth);
1548 
1549   // Print stack trace in external format
1550   void print_stack_on(outputStream* st);
1551   void print_stack() { print_stack_on(tty); }
1552 
1553   // Print stack traces in various internal formats
1554   void trace_stack()                             PRODUCT_RETURN;
1555   void trace_stack_from(vframe* start_vf)        PRODUCT_RETURN;
1556   void trace_frames()                            PRODUCT_RETURN;
1557   void trace_oops()                              PRODUCT_RETURN;
1558 
1559   // Print an annotated view of the stack frames
1560   void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN;
1561   void validate_frame_layout() {
1562     print_frame_layout(0, true);
1563   }
1564 
1565   // Returns the number of stack frames on the stack
1566   int depth() const;
1567 
1568   // Function for testing deoptimization
1569   void deoptimize();
1570   void make_zombies();
1571 
1572   void deoptimized_wrt_marked_nmethods();
1573 
1574   // Profiling operation (see fprofile.cpp)
1575  public:
1576    bool profile_last_Java_frame(frame* fr);
1577 
1578  private:
1579    ThreadProfiler* _thread_profiler;
1580  private:
1581    friend class FlatProfiler;                    // uses both [gs]et_thread_profiler.
1582    friend class FlatProfilerTask;                // uses get_thread_profiler.
1583    friend class ThreadProfilerMark;              // uses get_thread_profiler.
1584    ThreadProfiler* get_thread_profiler()         { return _thread_profiler; }
1585    ThreadProfiler* set_thread_profiler(ThreadProfiler* tp) {
1586      ThreadProfiler* result = _thread_profiler;
1587      _thread_profiler = tp;
1588      return result;
1589    }
1590 
1591  public:
1592   // Returns the running thread as a JavaThread
1593   static inline JavaThread* current();
1594 
1595   // Returns the active Java thread.  Do not use this if you know you are calling
1596   // from a JavaThread, as it's slower than JavaThread::current.  If called from
1597   // the VMThread, it also returns the JavaThread that instigated the VMThread's
1598   // operation.  You may not want that either.
1599   static JavaThread* active();
1600 
1601   inline CompilerThread* as_CompilerThread();
1602 
1603  public:
1604   virtual void run();
1605   void thread_main_inner();
1606 
1607  private:
1608   // PRIVILEGED STACK
1609   PrivilegedElement*  _privileged_stack_top;
1610   GrowableArray<oop>* _array_for_gc;
1611  public:
1612 
1613   // Returns the privileged_stack information.
1614   PrivilegedElement* privileged_stack_top() const       { return _privileged_stack_top; }
1615   void set_privileged_stack_top(PrivilegedElement *e)   { _privileged_stack_top = e; }
1616   void register_array_for_gc(GrowableArray<oop>* array) { _array_for_gc = array; }
1617 
1618  public:
1619   // Thread local information maintained by JVMTI.
1620   void set_jvmti_thread_state(JvmtiThreadState *value)                           { _jvmti_thread_state = value; }
1621   // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1622   // getter is used to get this JavaThread's JvmtiThreadState if it has
1623   // one which means NULL can be returned. JvmtiThreadState::state_for()
1624   // is used to get the specified JavaThread's JvmtiThreadState if it has
1625   // one or it allocates a new JvmtiThreadState for the JavaThread and
1626   // returns it. JvmtiThreadState::state_for() will return NULL only if
1627   // the specified JavaThread is exiting.
1628   JvmtiThreadState *jvmti_thread_state() const                                   { return _jvmti_thread_state; }
1629   static ByteSize jvmti_thread_state_offset()                                    { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1630   void set_jvmti_get_loaded_classes_closure(JvmtiGetLoadedClassesClosure* value) { _jvmti_get_loaded_classes_closure = value; }
1631   JvmtiGetLoadedClassesClosure* get_jvmti_get_loaded_classes_closure() const     { return _jvmti_get_loaded_classes_closure; }
1632 
1633   // JVMTI PopFrame support
1634   // Setting and clearing popframe_condition
1635   // All of these enumerated values are bits. popframe_pending
1636   // indicates that a PopFrame() has been requested and not yet been
1637   // completed. popframe_processing indicates that that PopFrame() is in
1638   // the process of being completed. popframe_force_deopt_reexecution_bit
1639   // indicates that special handling is required when returning to a
1640   // deoptimized caller.
1641   enum PopCondition {
1642     popframe_inactive                      = 0x00,
1643     popframe_pending_bit                   = 0x01,
1644     popframe_processing_bit                = 0x02,
1645     popframe_force_deopt_reexecution_bit   = 0x04
1646   };
1647   PopCondition popframe_condition()                   { return (PopCondition) _popframe_condition; }
1648   void set_popframe_condition(PopCondition c)         { _popframe_condition = c; }
1649   void set_popframe_condition_bit(PopCondition c)     { _popframe_condition |= c; }
1650   void clear_popframe_condition()                     { _popframe_condition = popframe_inactive; }
1651   static ByteSize popframe_condition_offset()         { return byte_offset_of(JavaThread, _popframe_condition); }
1652   bool has_pending_popframe()                         { return (popframe_condition() & popframe_pending_bit) != 0; }
1653   bool popframe_forcing_deopt_reexecution()           { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
1654   void clear_popframe_forcing_deopt_reexecution()     { _popframe_condition &= ~popframe_force_deopt_reexecution_bit; }
1655 #ifdef CC_INTERP
1656   bool pop_frame_pending(void)                        { return ((_popframe_condition & popframe_pending_bit) != 0); }
1657   void clr_pop_frame_pending(void)                    { _popframe_condition = popframe_inactive; }
1658   bool pop_frame_in_process(void)                     { return ((_popframe_condition & popframe_processing_bit) != 0); }
1659   void set_pop_frame_in_process(void)                 { _popframe_condition |= popframe_processing_bit; }
1660   void clr_pop_frame_in_process(void)                 { _popframe_condition &= ~popframe_processing_bit; }
1661 #endif
1662 
1663   int frames_to_pop_failed_realloc() const            { return _frames_to_pop_failed_realloc; }
1664   void set_frames_to_pop_failed_realloc(int nb)       { _frames_to_pop_failed_realloc = nb; }
1665   void dec_frames_to_pop_failed_realloc()             { _frames_to_pop_failed_realloc--; }
1666 
1667  private:
1668   // Saved incoming arguments to popped frame.
1669   // Used only when popped interpreted frame returns to deoptimized frame.
1670   void*    _popframe_preserved_args;
1671   int      _popframe_preserved_args_size;
1672 
1673  public:
1674   void  popframe_preserve_args(ByteSize size_in_bytes, void* start);
1675   void* popframe_preserved_args();
1676   ByteSize popframe_preserved_args_size();
1677   WordSize popframe_preserved_args_size_in_words();
1678   void  popframe_free_preserved_args();
1679 
1680 
1681  private:
1682   JvmtiThreadState *_jvmti_thread_state;
1683   JvmtiGetLoadedClassesClosure* _jvmti_get_loaded_classes_closure;
1684 
1685   // Used by the interpreter in fullspeed mode for frame pop, method
1686   // entry, method exit and single stepping support. This field is
1687   // only set to non-zero by the VM_EnterInterpOnlyMode VM operation.
1688   // It can be set to zero asynchronously (i.e., without a VM operation
1689   // or a lock) so we have to be very careful.
1690   int               _interp_only_mode;
1691 
1692  public:
1693   // used by the interpreter for fullspeed debugging support (see above)
1694   static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
1695   bool is_interp_only_mode()                { return (_interp_only_mode != 0); }
1696   int get_interp_only_mode()                { return _interp_only_mode; }
1697   void increment_interp_only_mode()         { ++_interp_only_mode; }
1698   void decrement_interp_only_mode()         { --_interp_only_mode; }
1699 
1700   // support for cached flag that indicates whether exceptions need to be posted for this thread
1701   // if this is false, we can avoid deoptimizing when events are thrown
1702   // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
1703  private:
1704   int    _should_post_on_exceptions_flag;
1705 
1706  public:
1707   int   should_post_on_exceptions_flag()  { return _should_post_on_exceptions_flag; }
1708   void  set_should_post_on_exceptions_flag(int val)  { _should_post_on_exceptions_flag = val; }
1709 
1710  private:
1711   ThreadStatistics *_thread_stat;
1712 
1713  public:
1714   ThreadStatistics* get_thread_stat() const    { return _thread_stat; }
1715 
1716   // Return a blocker object for which this thread is blocked parking.
1717   oop current_park_blocker();
1718 
1719  private:
1720   static size_t _stack_size_at_create;
1721 
1722  public:
1723   static inline size_t stack_size_at_create(void) {
1724     return _stack_size_at_create;
1725   }
1726   static inline void set_stack_size_at_create(size_t value) {
1727     _stack_size_at_create = value;
1728   }
1729 
1730 #if INCLUDE_ALL_GCS
1731   // SATB marking queue support
1732   ObjPtrQueue& satb_mark_queue() { return _satb_mark_queue; }
1733   static SATBMarkQueueSet& satb_mark_queue_set() {
1734     return _satb_mark_queue_set;
1735   }
1736 
1737   // Dirty card queue support
1738   DirtyCardQueue& dirty_card_queue() { return _dirty_card_queue; }
1739   static DirtyCardQueueSet& dirty_card_queue_set() {
1740     return _dirty_card_queue_set;
1741   }
1742 
1743   inline char gc_state() const;
1744 
1745 private:
1746   void set_gc_state(char in_prog);
1747 
1748 public:
1749   static void set_gc_state_all_threads(char in_prog);
1750   static void set_force_satb_flush_all_threads(bool value);
1751 #endif // INCLUDE_ALL_GCS
1752 
1753   // This method initializes the SATB and dirty card queues before a
1754   // JavaThread is added to the Java thread list. Right now, we don't
1755   // have to do anything to the dirty card queue (it should have been
1756   // activated when the thread was created), but we have to activate
1757   // the SATB queue if the thread is created while a marking cycle is
1758   // in progress. The activation / de-activation of the SATB queues at
1759   // the beginning / end of a marking cycle is done during safepoints
1760   // so we have to make sure this method is called outside one to be
1761   // able to safely read the active field of the SATB queue set. Right
1762   // now, it is called just before the thread is added to the Java
1763   // thread list in the Threads::add() method. That method is holding
1764   // the Threads_lock which ensures we are outside a safepoint. We
1765   // cannot do the obvious and set the active field of the SATB queue
1766   // when the thread is created given that, in some cases, safepoints
1767   // might happen between the JavaThread constructor being called and the
1768   // thread being added to the Java thread list (an example of this is
1769   // when the structure for the DestroyJavaVM thread is created).
1770 #if INCLUDE_ALL_GCS
1771   void initialize_queues();
1772 #else  // INCLUDE_ALL_GCS
1773   void initialize_queues() { }
1774 #endif // INCLUDE_ALL_GCS
1775 
1776   // Machine dependent stuff
1777 #ifdef TARGET_OS_ARCH_linux_x86
1778 # include "thread_linux_x86.hpp"
1779 #endif
1780 #ifdef TARGET_OS_ARCH_linux_aarch64
1781 # include "thread_linux_aarch64.hpp"
1782 #endif
1783 #ifdef TARGET_OS_ARCH_linux_sparc
1784 # include "thread_linux_sparc.hpp"
1785 #endif
1786 #ifdef TARGET_OS_ARCH_linux_zero
1787 # include "thread_linux_zero.hpp"
1788 #endif
1789 #ifdef TARGET_OS_ARCH_solaris_x86
1790 # include "thread_solaris_x86.hpp"
1791 #endif
1792 #ifdef TARGET_OS_ARCH_solaris_sparc
1793 # include "thread_solaris_sparc.hpp"
1794 #endif
1795 #ifdef TARGET_OS_ARCH_windows_x86
1796 # include "thread_windows_x86.hpp"
1797 #endif
1798 #ifdef TARGET_OS_ARCH_linux_arm
1799 # include "thread_linux_arm.hpp"
1800 #endif
1801 #ifdef TARGET_OS_ARCH_linux_ppc
1802 # include "thread_linux_ppc.hpp"
1803 #endif
1804 #ifdef TARGET_OS_ARCH_aix_ppc
1805 # include "thread_aix_ppc.hpp"
1806 #endif
1807 #ifdef TARGET_OS_ARCH_bsd_x86
1808 # include "thread_bsd_x86.hpp"
1809 #endif
1810 #ifdef TARGET_OS_ARCH_bsd_zero
1811 # include "thread_bsd_zero.hpp"
1812 #endif
1813 
1814 
1815  public:
1816   void set_blocked_on_compilation(bool value) {
1817     _blocked_on_compilation = value;
1818   }
1819 
1820   bool blocked_on_compilation() {
1821     return _blocked_on_compilation;
1822   }
1823  protected:
1824   bool         _blocked_on_compilation;
1825 
1826 
1827   // JSR166 per-thread parker
1828 private:
1829   Parker*    _parker;
1830 public:
1831   Parker*     parker() { return _parker; }
1832 
1833   // Biased locking support
1834 private:
1835   GrowableArray<MonitorInfo*>* _cached_monitor_info;
1836 public:
1837   GrowableArray<MonitorInfo*>* cached_monitor_info() { return _cached_monitor_info; }
1838   void set_cached_monitor_info(GrowableArray<MonitorInfo*>* info) { _cached_monitor_info = info; }
1839 
1840   // clearing/querying jni attach status
1841   bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; }
1842   bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
1843   inline void set_done_attaching_via_jni();
1844 private:
1845   // This field is used to determine if a thread has claimed
1846   // a par_id: it is UINT_MAX if the thread has not claimed a par_id;
1847   // otherwise its value is the par_id that has been claimed.
1848   uint _claimed_par_id;
1849 public:
1850   uint get_claimed_par_id() { return _claimed_par_id; }
1851   void set_claimed_par_id(uint id) { _claimed_par_id = id;}
1852 };
1853 
1854 // Inline implementation of JavaThread::current
1855 inline JavaThread* JavaThread::current() {
1856   Thread* thread = Thread::current();
1857   assert(thread->is_Java_thread(), "just checking");
1858   return (JavaThread*)thread;
1859 }
1860 
1861 inline CompilerThread* JavaThread::as_CompilerThread() {
1862   assert(is_Compiler_thread(), "just checking");
1863   return (CompilerThread*)this;
1864 }
1865 
1866 inline bool JavaThread::stack_guard_zone_unused() {
1867   return _stack_guard_state == stack_guard_unused;
1868 }
1869 
1870 inline bool JavaThread::stack_yellow_zone_disabled() {
1871   return _stack_guard_state == stack_guard_yellow_disabled;
1872 }
1873 
1874 inline bool JavaThread::stack_yellow_zone_enabled() {
1875 #ifdef ASSERT
1876   if (os::uses_stack_guard_pages() &&
1877       !(DisablePrimordialThreadGuardPages && os::is_primordial_thread())) {
1878     assert(_stack_guard_state != stack_guard_unused, "guard pages must be in use");
1879   }
1880 #endif
1881     return _stack_guard_state == stack_guard_enabled;
1882 }
1883 
1884 inline size_t JavaThread::stack_available(address cur_sp) {
1885   // This code assumes java stacks grow down
1886   address low_addr; // Limit on the address for deepest stack depth
1887   if ( _stack_guard_state == stack_guard_unused) {
1888     low_addr =  stack_base() - stack_size();
1889   } else {
1890     low_addr = stack_yellow_zone_base();
1891   }
1892   return cur_sp > low_addr ? cur_sp - low_addr : 0;
1893 }
1894 
1895 // A thread used for Compilation.
1896 class CompilerThread : public JavaThread {
1897   friend class VMStructs;
1898  private:
1899   CompilerCounters* _counters;
1900 
1901   ciEnv*            _env;
1902   CompileLog*       _log;
1903   CompileTask*      _task;
1904   CompileQueue*     _queue;
1905   BufferBlob*       _buffer_blob;
1906 
1907   nmethod*          _scanned_nmethod;  // nmethod being scanned by the sweeper
1908   AbstractCompiler* _compiler;
1909 
1910  public:
1911 
1912   static CompilerThread* current();
1913 
1914   CompilerThread(CompileQueue* queue, CompilerCounters* counters);
1915 
1916   bool is_Compiler_thread() const                { return true; }
1917   // Hide this compiler thread from external view.
1918   bool is_hidden_from_external_view() const      { return true; }
1919 
1920   void set_compiler(AbstractCompiler* c)         { _compiler = c; }
1921   AbstractCompiler* compiler() const             { return _compiler; }
1922 
1923   CompileQueue* queue()        const             { return _queue; }
1924   CompilerCounters* counters() const             { return _counters; }
1925 
1926   // Get/set the thread's compilation environment.
1927   ciEnv*        env()                            { return _env; }
1928   void          set_env(ciEnv* env)              { _env = env; }
1929 
1930   BufferBlob*   get_buffer_blob() const          { return _buffer_blob; }
1931   void          set_buffer_blob(BufferBlob* b)   { _buffer_blob = b; };
1932 
1933   // Get/set the thread's logging information
1934   CompileLog*   log()                            { return _log; }
1935   void          init_log(CompileLog* log) {
1936     // Set once, for good.
1937     assert(_log == NULL, "set only once");
1938     _log = log;
1939   }
1940 
1941   // GC support
1942   // Apply "f->do_oop" to all root oops in "this".
1943   // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames
1944   void oops_do(OopClosure* f, CLDClosure* cld_f, CodeBlobClosure* cf);
1945 
1946 #ifndef PRODUCT
1947 private:
1948   IdealGraphPrinter *_ideal_graph_printer;
1949 public:
1950   IdealGraphPrinter *ideal_graph_printer()                       { return _ideal_graph_printer; }
1951   void set_ideal_graph_printer(IdealGraphPrinter *n)             { _ideal_graph_printer = n; }
1952 #endif
1953 
1954   // Get/set the thread's current task
1955   CompileTask*  task()                           { return _task; }
1956   void          set_task(CompileTask* task)      { _task = task; }
1957 
1958   // Track the nmethod currently being scanned by the sweeper
1959   void          set_scanned_nmethod(nmethod* nm) {
1960     assert(_scanned_nmethod == NULL || nm == NULL, "should reset to NULL before writing a new value");
1961     _scanned_nmethod = nm;
1962   }
1963 };
1964 
1965 inline CompilerThread* CompilerThread::current() {
1966   return JavaThread::current()->as_CompilerThread();
1967 }
1968 
1969 
1970 // The active thread queue. It also keeps track of the current used
1971 // thread priorities.
1972 class Threads: AllStatic {
1973   friend class VMStructs;
1974  private:
1975   static JavaThread* _thread_list;
1976   static int         _number_of_threads;
1977   static int         _number_of_non_daemon_threads;
1978   static int         _return_code;
1979 #ifdef ASSERT
1980   static bool        _vm_complete;
1981 #endif
1982 
1983  public:
1984   // Thread management
1985   // force_daemon is a concession to JNI, where we may need to add a
1986   // thread to the thread list before allocating its thread object
1987   static void add(JavaThread* p, bool force_daemon = false);
1988   static void remove(JavaThread* p);
1989   static bool includes(JavaThread* p);
1990   static JavaThread* first()                     { return _thread_list; }
1991   static void threads_do(ThreadClosure* tc);
1992   static void java_threads_do(ThreadClosure* tc);
1993 
1994   // Initializes the vm and creates the vm thread
1995   static jint create_vm(JavaVMInitArgs* args, bool* canTryAgain);
1996   static void convert_vm_init_libraries_to_agents();
1997   static void create_vm_init_libraries();
1998   static void create_vm_init_agents();
1999   static void shutdown_vm_agents();
2000   static bool destroy_vm();
2001   // Supported VM versions via JNI
2002   // Includes JNI_VERSION_1_1
2003   static jboolean is_supported_jni_version_including_1_1(jint version);
2004   // Does not include JNI_VERSION_1_1
2005   static jboolean is_supported_jni_version(jint version);
2006 
2007   // Garbage collection
2008   static void follow_other_roots(void f(oop*));
2009 
2010   // Apply "f->do_oop" to all root oops in all threads.
2011   // This version may only be called by sequential code.
2012   static void oops_do(OopClosure* f, CLDClosure* cld_f, CodeBlobClosure* cf);
2013   // This version may be called by sequential or parallel code.
2014   static void possibly_parallel_oops_do(OopClosure* f, CLDClosure* cld_f, CodeBlobClosure* cf);
2015   // This creates a list of GCTasks, one per thread.
2016   static void create_thread_roots_tasks(GCTaskQueue* q);
2017   // This creates a list of GCTasks, one per thread, for marking objects.
2018   static void create_thread_roots_marking_tasks(GCTaskQueue* q);
2019 
2020   // Apply "f->do_oop" to roots in all threads that
2021   // are part of compiled frames
2022   static void compiled_frame_oops_do(OopClosure* f, CodeBlobClosure* cf);
2023 
2024   static void convert_hcode_pointers();
2025   static void restore_hcode_pointers();
2026 
2027   // Sweeper
2028   static void nmethods_do(CodeBlobClosure* cf);
2029 
2030   // RedefineClasses support
2031   static void metadata_do(void f(Metadata*));
2032 
2033   static void gc_epilogue();
2034   static void gc_prologue();
2035 #ifdef ASSERT
2036   static bool is_vm_complete() { return _vm_complete; }
2037 #endif
2038 
2039   // Verification
2040   static void verify();
2041   static void print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks);
2042   static void print(bool print_stacks, bool internal_format) {
2043     // this function is only used by debug.cpp
2044     print_on(tty, print_stacks, internal_format, false /* no concurrent lock printed */);
2045   }
2046   static void print_on_error(outputStream* st, Thread* current, char* buf, int buflen);
2047 
2048   // Get Java threads that are waiting to enter a monitor. If doLock
2049   // is true, then Threads_lock is grabbed as needed. Otherwise, the
2050   // VM needs to be at a safepoint.
2051   static GrowableArray<JavaThread*>* get_pending_threads(int count,
2052     address monitor, bool doLock);
2053 
2054   // Get owning Java thread from the monitor's owner field. If doLock
2055   // is true, then Threads_lock is grabbed as needed. Otherwise, the
2056   // VM needs to be at a safepoint.
2057   static JavaThread *owning_thread_from_monitor_owner(address owner,
2058     bool doLock);
2059 
2060   // Number of threads on the active threads list
2061   static int number_of_threads()                 { return _number_of_threads; }
2062   // Number of non-daemon threads on the active threads list
2063   static int number_of_non_daemon_threads()      { return _number_of_non_daemon_threads; }
2064 
2065   // Deoptimizes all frames tied to marked nmethods
2066   static void deoptimized_wrt_marked_nmethods();
2067 
2068   static JavaThread* find_java_thread_from_java_tid(jlong java_tid);
2069 
2070 };
2071 
2072 
2073 // Thread iterator
2074 class ThreadClosure: public StackObj {
2075  public:
2076   virtual void do_thread(Thread* thread) = 0;
2077 };
2078 
2079 class SignalHandlerMark: public StackObj {
2080 private:
2081   Thread* _thread;
2082 public:
2083   SignalHandlerMark(Thread* t) {
2084     _thread = t;
2085     if (_thread) _thread->enter_signal_handler();
2086   }
2087   ~SignalHandlerMark() {
2088     if (_thread) _thread->leave_signal_handler();
2089     _thread = NULL;
2090   }
2091 };
2092 
2093 
2094 #endif // SHARE_VM_RUNTIME_THREAD_HPP