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