1 /*
   2  * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_RUNTIME_THREAD_HPP
  26 #define SHARE_VM_RUNTIME_THREAD_HPP
  27 

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