rev 56635 : v2.00 -> v2.05 (CR5/v2.05/8-for-jdk13) patches combined into one; merge with 8229212.patch; merge with jdk-14+11; merge with 8230184.patch; merge with 8230876.patch; merge with jdk-14+15; merge with jdk-14+18.
rev 56637 : Add OM_CACHE_LINE_SIZE so that ObjectMonitor cache line sizes can be experimented with independently of DEFAULT_CACHE_LINE_SIZE; for SPARC and X64 configs that use 128 for DEFAULT_CACHE_LINE_SIZE, we are experimenting with 64; move _previous_owner_tid and _allocation_state fields to share the cache line with ObjectMonitor::_header; put ObjectMonitor::_ref_count on its own cache line after _owner; add 'int* count_p' parameter to deflate_monitor_list() and deflate_monitor_list_using_JT() and push counter updates down to where the ObjectMonitors are actually removed from the in-use lists; monitors_iterate() async deflation check should use negative ref_count; add 'JavaThread* target' param to deflate_per_thread_idle_monitors_using_JT() add deflate_common_idle_monitors_using_JT() to make it clear which JavaThread* is the target of the work and which is the calling JavaThread* (self); g_free_list, g_om_in_use_list and g_om_in_use_count are now static to synchronizer.cpp (reduce scope); add more diagnostic info to some assert()'s; minor code cleanups and code motion; save_om_ptr() should detect a race with a deflating thread that is bailing out and cause a retry when the ref_count field is not positive; merge with jdk-14+11; add special GC support for TestHumongousClassLoader.java; merge with 8230184.patch; merge with jdk-14+14; merge with jdk-14+18.
rev 56638 : Merge the remainder of the lock-free monitor list changes from v2.06 with v2.06a and v2.06b after running the changes through the edit scripts; merge pieces from dcubed.monitor_deflate_conc.v2.06d in dcubed.monitor_deflate_conc.v2.06[ac]; merge pieces from dcubed.monitor_deflate_conc.v2.06e into dcubed.monitor_deflate_conc.v2.06c; merge with jdk-14+11; test work around for test/jdk/tools/jlink/multireleasejar/JLinkMultiReleaseJarTest.java should not been needed anymore; merge with jdk-14+18.

   1 /*
   2  * Copyright (c) 1997, 2019, 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_RUNTIME_THREAD_HPP
  26 #define SHARE_RUNTIME_THREAD_HPP
  27 
  28 #include "jni.h"
  29 #include "code/compiledMethod.hpp"
  30 #include "gc/shared/gcThreadLocalData.hpp"
  31 #include "gc/shared/threadLocalAllocBuffer.hpp"
  32 #include "memory/allocation.hpp"
  33 #include "oops/oop.hpp"
  34 #include "prims/jvmtiExport.hpp"
  35 #include "runtime/frame.hpp"
  36 #include "runtime/globals.hpp"
  37 #include "runtime/handshake.hpp"
  38 #include "runtime/javaFrameAnchor.hpp"
  39 #include "runtime/jniHandles.hpp"
  40 #include "runtime/mutexLocker.hpp"
  41 #include "runtime/os.hpp"
  42 #include "runtime/osThread.hpp"
  43 #include "runtime/park.hpp"
  44 #include "runtime/stubRoutines.hpp"
  45 #include "runtime/threadHeapSampler.hpp"
  46 #include "runtime/threadLocalStorage.hpp"
  47 #include "runtime/threadStatisticalInfo.hpp"
  48 #include "runtime/unhandledOops.hpp"
  49 #include "utilities/align.hpp"
  50 #include "utilities/exceptions.hpp"
  51 #include "utilities/macros.hpp"
  52 #ifdef ZERO
  53 # include "stack_zero.hpp"
  54 #endif
  55 #if INCLUDE_JFR
  56 #include "jfr/support/jfrThreadExtension.hpp"
  57 #endif
  58 
  59 
  60 class SafeThreadsListPtr;
  61 class ThreadSafepointState;
  62 class ThreadsList;
  63 class ThreadsSMRSupport;
  64 
  65 class JvmtiRawMonitor;
  66 class JvmtiThreadState;
  67 class ThreadStatistics;
  68 class ConcurrentLocksDump;
  69 class ParkEvent;
  70 class Parker;
  71 class MonitorInfo;
  72 
  73 class ciEnv;
  74 class CompileThread;
  75 class CompileLog;
  76 class CompileTask;
  77 class CompileQueue;
  78 class CompilerCounters;
  79 
  80 class vframeArray;
  81 class vframe;
  82 class javaVFrame;
  83 
  84 class DeoptResourceMark;
  85 class jvmtiDeferredLocalVariableSet;
  86 
  87 class ThreadClosure;
  88 class ICRefillVerifier;
  89 class IdealGraphPrinter;
  90 
  91 class JVMCIEnv;
  92 class JVMCIPrimitiveArray;
  93 
  94 class Metadata;
  95 class ResourceArea;
  96 
  97 DEBUG_ONLY(class ResourceMark;)
  98 
  99 class WorkerThread;
 100 
 101 // Class hierarchy
 102 // - Thread
 103 //   - JavaThread
 104 //     - various subclasses eg CompilerThread, ServiceThread
 105 //   - NonJavaThread
 106 //     - NamedThread
 107 //       - VMThread
 108 //       - ConcurrentGCThread
 109 //       - WorkerThread
 110 //         - GangWorker
 111 //     - WatcherThread
 112 //     - JfrThreadSampler
 113 //
 114 // All Thread subclasses must be either JavaThread or NonJavaThread.
 115 // This means !t->is_Java_thread() iff t is a NonJavaThread, or t is
 116 // a partially constructed/destroyed Thread.
 117 
 118 // Thread execution sequence and actions:
 119 // All threads:
 120 //  - thread_native_entry  // per-OS native entry point
 121 //    - stack initialization
 122 //    - other OS-level initialization (signal masks etc)
 123 //    - handshake with creating thread (if not started suspended)
 124 //    - this->call_run()  // common shared entry point
 125 //      - shared common initialization
 126 //      - this->pre_run()  // virtual per-thread-type initialization
 127 //      - this->run()      // virtual per-thread-type "main" logic
 128 //      - shared common tear-down
 129 //      - this->post_run()  // virtual per-thread-type tear-down
 130 //      - // 'this' no longer referenceable
 131 //    - OS-level tear-down (minimal)
 132 //    - final logging
 133 //
 134 // For JavaThread:
 135 //   - this->run()  // virtual but not normally overridden
 136 //     - this->thread_main_inner()  // extra call level to ensure correct stack calculations
 137 //       - this->entry_point()  // set differently for each kind of JavaThread
 138 
 139 class Thread: public ThreadShadow {
 140   friend class VMStructs;
 141   friend class JVMCIVMStructs;
 142  private:
 143 
 144 #ifndef USE_LIBRARY_BASED_TLS_ONLY
 145   // Current thread is maintained as a thread-local variable
 146   static THREAD_LOCAL Thread* _thr_current;
 147 #endif
 148 
 149   // Thread local data area available to the GC. The internal
 150   // structure and contents of this data area is GC-specific.
 151   // Only GC and GC barrier code should access this data area.
 152   GCThreadLocalData _gc_data;
 153 
 154  public:
 155   static ByteSize gc_data_offset() {
 156     return byte_offset_of(Thread, _gc_data);
 157   }
 158 
 159   template <typename T> T* gc_data() {
 160     STATIC_ASSERT(sizeof(T) <= sizeof(_gc_data));
 161     return reinterpret_cast<T*>(&_gc_data);
 162   }
 163 
 164   // Exception handling
 165   // (Note: _pending_exception and friends are in ThreadShadow)
 166   //oop       _pending_exception;                // pending exception for current thread
 167   // const char* _exception_file;                   // file information for exception (debugging only)
 168   // int         _exception_line;                   // line information for exception (debugging only)
 169  protected:
 170 
 171   DEBUG_ONLY(static Thread* _starting_thread;)
 172 
 173   // Support for forcing alignment of thread objects for biased locking
 174   void*       _real_malloc_address;
 175 
 176   // JavaThread lifecycle support:
 177   friend class SafeThreadsListPtr;  // for _threads_list_ptr, cmpxchg_threads_hazard_ptr(), {dec_,inc_,}nested_threads_hazard_ptr_cnt(), {g,s}et_threads_hazard_ptr(), inc_nested_handle_cnt(), tag_hazard_ptr() access
 178   friend class ScanHazardPtrGatherProtectedThreadsClosure;  // for cmpxchg_threads_hazard_ptr(), get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
 179   friend class ScanHazardPtrGatherThreadsListClosure;  // for get_threads_hazard_ptr(), untag_hazard_ptr() access
 180   friend class ScanHazardPtrPrintMatchingThreadsClosure;  // for get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
 181   friend class ThreadsSMRSupport;  // for _nested_threads_hazard_ptr_cnt, _threads_hazard_ptr, _threads_list_ptr access
 182 
 183   ThreadsList* volatile _threads_hazard_ptr;
 184   SafeThreadsListPtr*   _threads_list_ptr;
 185   ThreadsList*          cmpxchg_threads_hazard_ptr(ThreadsList* exchange_value, ThreadsList* compare_value);
 186   ThreadsList*          get_threads_hazard_ptr();
 187   void                  set_threads_hazard_ptr(ThreadsList* new_list);
 188   static bool           is_hazard_ptr_tagged(ThreadsList* list) {
 189     return (intptr_t(list) & intptr_t(1)) == intptr_t(1);
 190   }
 191   static ThreadsList*   tag_hazard_ptr(ThreadsList* list) {
 192     return (ThreadsList*)(intptr_t(list) | intptr_t(1));
 193   }
 194   static ThreadsList*   untag_hazard_ptr(ThreadsList* list) {
 195     return (ThreadsList*)(intptr_t(list) & ~intptr_t(1));
 196   }
 197   // This field is enabled via -XX:+EnableThreadSMRStatistics:
 198   uint _nested_threads_hazard_ptr_cnt;
 199   void dec_nested_threads_hazard_ptr_cnt() {
 200     assert(_nested_threads_hazard_ptr_cnt != 0, "mismatched {dec,inc}_nested_threads_hazard_ptr_cnt()");
 201     _nested_threads_hazard_ptr_cnt--;
 202   }
 203   void inc_nested_threads_hazard_ptr_cnt() {
 204     _nested_threads_hazard_ptr_cnt++;
 205   }
 206   uint nested_threads_hazard_ptr_cnt() {
 207     return _nested_threads_hazard_ptr_cnt;
 208   }
 209 
 210  public:
 211   void* operator new(size_t size) throw() { return allocate(size, true); }
 212   void* operator new(size_t size, const std::nothrow_t& nothrow_constant) throw() {
 213     return allocate(size, false); }
 214   void  operator delete(void* p);
 215 
 216  protected:
 217   static void* allocate(size_t size, bool throw_excpt, MEMFLAGS flags = mtThread);
 218  private:
 219 
 220   // ***************************************************************
 221   // Suspend and resume support
 222   // ***************************************************************
 223   //
 224   // VM suspend/resume no longer exists - it was once used for various
 225   // things including safepoints but was deprecated and finally removed
 226   // in Java 7. Because VM suspension was considered "internal" Java-level
 227   // suspension was considered "external", and this legacy naming scheme
 228   // remains.
 229   //
 230   // External suspend/resume requests come from JVM_SuspendThread,
 231   // JVM_ResumeThread, JVMTI SuspendThread, and finally JVMTI
 232   // ResumeThread. External
 233   // suspend requests cause _external_suspend to be set and external
 234   // resume requests cause _external_suspend to be cleared.
 235   // External suspend requests do not nest on top of other external
 236   // suspend requests. The higher level APIs reject suspend requests
 237   // for already suspended threads.
 238   //
 239   // The external_suspend
 240   // flag is checked by has_special_runtime_exit_condition() and java thread
 241   // will self-suspend when handle_special_runtime_exit_condition() is
 242   // called. Most uses of the _thread_blocked state in JavaThreads are
 243   // considered the same as being externally suspended; if the blocking
 244   // condition lifts, the JavaThread will self-suspend. Other places
 245   // where VM checks for external_suspend include:
 246   //   + mutex granting (do not enter monitors when thread is suspended)
 247   //   + state transitions from _thread_in_native
 248   //
 249   // In general, java_suspend() does not wait for an external suspend
 250   // request to complete. When it returns, the only guarantee is that
 251   // the _external_suspend field is true.
 252   //
 253   // wait_for_ext_suspend_completion() is used to wait for an external
 254   // suspend request to complete. External suspend requests are usually
 255   // followed by some other interface call that requires the thread to
 256   // be quiescent, e.g., GetCallTrace(). By moving the "wait time" into
 257   // the interface that requires quiescence, we give the JavaThread a
 258   // chance to self-suspend before we need it to be quiescent. This
 259   // improves overall suspend/query performance.
 260   //
 261   // _suspend_flags controls the behavior of java_ suspend/resume.
 262   // It must be set under the protection of SR_lock. Read from the flag is
 263   // OK without SR_lock as long as the value is only used as a hint.
 264   // (e.g., check _external_suspend first without lock and then recheck
 265   // inside SR_lock and finish the suspension)
 266   //
 267   // _suspend_flags is also overloaded for other "special conditions" so
 268   // that a single check indicates whether any special action is needed
 269   // eg. for async exceptions.
 270   // -------------------------------------------------------------------
 271   // Notes:
 272   // 1. The suspend/resume logic no longer uses ThreadState in OSThread
 273   // but we still update its value to keep other part of the system (mainly
 274   // JVMTI) happy. ThreadState is legacy code (see notes in
 275   // osThread.hpp).
 276   //
 277   // 2. It would be more natural if set_external_suspend() is private and
 278   // part of java_suspend(), but that probably would affect the suspend/query
 279   // performance. Need more investigation on this.
 280 
 281   // suspend/resume lock: used for self-suspend
 282   Monitor* _SR_lock;
 283 
 284  protected:
 285   enum SuspendFlags {
 286     // NOTE: avoid using the sign-bit as cc generates different test code
 287     //       when the sign-bit is used, and sometimes incorrectly - see CR 6398077
 288 
 289     _external_suspend       = 0x20000000U, // thread is asked to self suspend
 290     _ext_suspended          = 0x40000000U, // thread has self-suspended
 291 
 292     _has_async_exception    = 0x00000001U, // there is a pending async exception
 293     _critical_native_unlock = 0x00000002U, // Must call back to unlock JNI critical lock
 294 
 295     _trace_flag             = 0x00000004U  // call tracing backend
 296   };
 297 
 298   // various suspension related flags - atomically updated
 299   // overloaded for async exception checking in check_special_condition_for_native_trans.
 300   volatile uint32_t _suspend_flags;
 301 
 302  private:
 303   int _num_nested_signal;
 304 
 305   DEBUG_ONLY(bool _suspendible_thread;)
 306 
 307  public:
 308   void enter_signal_handler() { _num_nested_signal++; }
 309   void leave_signal_handler() { _num_nested_signal--; }
 310   bool is_inside_signal_handler() const { return _num_nested_signal > 0; }
 311 
 312   // Determines if a heap allocation failure will be retried
 313   // (e.g., by deoptimizing and re-executing in the interpreter).
 314   // In this case, the failed allocation must raise
 315   // Universe::out_of_memory_error_retry() and omit side effects
 316   // such as JVMTI events and handling -XX:+HeapDumpOnOutOfMemoryError
 317   // and -XX:OnOutOfMemoryError.
 318   virtual bool in_retryable_allocation() const { return false; }
 319 
 320 #ifdef ASSERT
 321   void set_suspendible_thread() {
 322     _suspendible_thread = true;
 323   }
 324 
 325   void clear_suspendible_thread() {
 326     _suspendible_thread = false;
 327   }
 328 
 329   bool is_suspendible_thread() { return _suspendible_thread; }
 330 #endif
 331 
 332  private:
 333   // Active_handles points to a block of handles
 334   JNIHandleBlock* _active_handles;
 335 
 336   // One-element thread local free list
 337   JNIHandleBlock* _free_handle_block;
 338 
 339   // Point to the last handle mark
 340   HandleMark* _last_handle_mark;
 341 
 342   // Claim value for parallel iteration over threads.
 343   uintx _threads_do_token;
 344 
 345   // Support for GlobalCounter
 346  private:
 347   volatile uintx _rcu_counter;
 348  public:
 349   volatile uintx* get_rcu_counter() {
 350     return &_rcu_counter;
 351   }
 352 
 353  public:
 354   void set_last_handle_mark(HandleMark* mark)   { _last_handle_mark = mark; }
 355   HandleMark* last_handle_mark() const          { return _last_handle_mark; }
 356  private:
 357 
 358 #ifdef ASSERT
 359   ICRefillVerifier* _missed_ic_stub_refill_verifier;
 360 
 361  public:
 362   ICRefillVerifier* missed_ic_stub_refill_verifier() {
 363     return _missed_ic_stub_refill_verifier;
 364   }
 365 
 366   void set_missed_ic_stub_refill_verifier(ICRefillVerifier* verifier) {
 367     _missed_ic_stub_refill_verifier = verifier;
 368   }
 369 #endif // ASSERT
 370 
 371  private:
 372 
 373   // Debug support for checking if code allows safepoints or not.
 374   // Safepoints in the VM can happen because of allocation, invoking a VM operation, or blocking on
 375   // mutex, or blocking on an object synchronizer (Java locking).
 376   // If _no_safepoint_count is non-zero, then an assertion failure will happen in any of
 377   // the above cases.
 378   //
 379   // The class NoSafepointVerifier is used to set this counter.
 380   //
 381   NOT_PRODUCT(int _no_safepoint_count;)         // If 0, thread allow a safepoint to happen
 382 
 383  private:
 384   // Used by SkipGCALot class.
 385   NOT_PRODUCT(bool _skip_gcalot;)               // Should we elide gc-a-lot?
 386 
 387   friend class GCLocker;
 388   friend class NoSafepointVerifier;
 389   friend class PauseNoSafepointVerifier;
 390 
 391   volatile void* _polling_page;                 // Thread local polling page
 392 
 393   ThreadLocalAllocBuffer _tlab;                 // Thread-local eden
 394   jlong _allocated_bytes;                       // Cumulative number of bytes allocated on
 395                                                 // the Java heap
 396   ThreadHeapSampler _heap_sampler;              // For use when sampling the memory.
 397 
 398   ThreadStatisticalInfo _statistical_info;      // Statistics about the thread
 399 
 400   JFR_ONLY(DEFINE_THREAD_LOCAL_FIELD_JFR;)      // Thread-local data for jfr
 401 
 402   int   _vm_operation_started_count;            // VM_Operation support
 403   int   _vm_operation_completed_count;          // VM_Operation support
 404 
 405   ObjectMonitor* _current_pending_monitor;      // ObjectMonitor this thread
 406                                                 // is waiting to lock
 407   bool _current_pending_monitor_is_from_java;   // locking is from Java code
 408   JvmtiRawMonitor* _current_pending_raw_monitor; // JvmtiRawMonitor this thread
 409                                                  // is waiting to lock
 410 
 411 
 412   // ObjectMonitor on which this thread called Object.wait()
 413   ObjectMonitor* _current_waiting_monitor;
 414 
 415   // Per-thread ObjectMonitor lists:
 416  public:
 417   ObjectMonitor* volatile om_free_list;         // SLL of free ObjectMonitors
 418   volatile int om_free_count;                   // # on om_free_list
 419   int om_free_provision;                        // # to try to allocate next
 420   ObjectMonitor* volatile om_in_use_list;       // SLL of in-use ObjectMonitors
 421   volatile int om_in_use_count;                 // # on om_in_use_list
 422 
 423 #ifdef ASSERT
 424  private:
 425   volatile uint64_t _visited_for_critical_count;
 426 
 427  public:
 428   void set_visited_for_critical_count(uint64_t safepoint_id) {
 429     assert(_visited_for_critical_count == 0, "Must be reset before set");
 430     assert((safepoint_id & 0x1) == 1, "Must be odd");
 431     _visited_for_critical_count = safepoint_id;
 432   }
 433   void reset_visited_for_critical_count(uint64_t safepoint_id) {
 434     assert(_visited_for_critical_count == safepoint_id, "Was not visited");
 435     _visited_for_critical_count = 0;
 436   }
 437   bool was_visited_for_critical_count(uint64_t safepoint_id) const {
 438     return _visited_for_critical_count == safepoint_id;
 439   }
 440 #endif
 441 
 442  public:
 443   enum {
 444     is_definitely_current_thread = true
 445   };
 446 
 447   // Constructor
 448   Thread();
 449   virtual ~Thread() = 0;        // Thread is abstract.
 450 
 451   // Manage Thread::current()
 452   void initialize_thread_current();
 453   static void clear_thread_current(); // TLS cleanup needed before threads terminate
 454 
 455  protected:
 456   // To be implemented by children.
 457   virtual void run() = 0;
 458   virtual void pre_run() = 0;
 459   virtual void post_run() = 0;  // Note: Thread must not be deleted prior to calling this!
 460 
 461 #ifdef ASSERT
 462   enum RunState {
 463     PRE_CALL_RUN,
 464     CALL_RUN,
 465     PRE_RUN,
 466     RUN,
 467     POST_RUN
 468     // POST_CALL_RUN - can't define this one as 'this' may be deleted when we want to set it
 469   };
 470   RunState _run_state;  // for lifecycle checks
 471 #endif
 472 
 473 
 474  public:
 475   // invokes <ChildThreadClass>::run(), with common preparations and cleanups.
 476   void call_run();
 477 
 478   // Testers
 479   virtual bool is_VM_thread()       const            { return false; }
 480   virtual bool is_Java_thread()     const            { return false; }
 481   virtual bool is_Compiler_thread() const            { return false; }
 482   virtual bool is_Code_cache_sweeper_thread() const  { return false; }
 483   virtual bool is_hidden_from_external_view() const  { return false; }
 484   virtual bool is_jvmti_agent_thread() const         { return false; }
 485   // True iff the thread can perform GC operations at a safepoint.
 486   // Generally will be true only of VM thread and parallel GC WorkGang
 487   // threads.
 488   virtual bool is_GC_task_thread() const             { return false; }
 489   virtual bool is_Watcher_thread() const             { return false; }
 490   virtual bool is_ConcurrentGC_thread() const        { return false; }
 491   virtual bool is_Named_thread() const               { return false; }
 492   virtual bool is_Worker_thread() const              { return false; }
 493 
 494   // Can this thread make Java upcalls
 495   virtual bool can_call_java() const                 { return false; }
 496 
 497   // Is this a JavaThread that is on the VM's current ThreadsList?
 498   // If so it must participate in the safepoint protocol.
 499   virtual bool is_active_Java_thread() const         { return false; }
 500 
 501   // Casts
 502   virtual WorkerThread* as_Worker_thread() const     { return NULL; }
 503 
 504   virtual char* name() const { return (char*)"Unknown thread"; }
 505 
 506   // Returns the current thread (ASSERTS if NULL)
 507   static inline Thread* current();
 508   // Returns the current thread, or NULL if not attached
 509   static inline Thread* current_or_null();
 510   // Returns the current thread, or NULL if not attached, and is
 511   // safe for use from signal-handlers
 512   static inline Thread* current_or_null_safe();
 513 
 514   // Common thread operations
 515 #ifdef ASSERT
 516   static void check_for_dangling_thread_pointer(Thread *thread);
 517 #endif
 518   static void set_priority(Thread* thread, ThreadPriority priority);
 519   static ThreadPriority get_priority(const Thread* const thread);
 520   static void start(Thread* thread);
 521 
 522   void set_native_thread_name(const char *name) {
 523     assert(Thread::current() == this, "set_native_thread_name can only be called on the current thread");
 524     os::set_native_thread_name(name);
 525   }
 526 

 527   Monitor* SR_lock() const                       { return _SR_lock; }
 528 
 529   bool has_async_exception() const { return (_suspend_flags & _has_async_exception) != 0; }
 530 
 531   inline void set_suspend_flag(SuspendFlags f);
 532   inline void clear_suspend_flag(SuspendFlags f);
 533 
 534   inline void set_has_async_exception();
 535   inline void clear_has_async_exception();
 536 
 537   bool do_critical_native_unlock() const { return (_suspend_flags & _critical_native_unlock) != 0; }
 538 
 539   inline void set_critical_native_unlock();
 540   inline void clear_critical_native_unlock();
 541 
 542   inline void set_trace_flag();
 543   inline void clear_trace_flag();
 544 
 545   // Support for Unhandled Oop detection
 546   // Add the field for both, fastdebug and debug, builds to keep
 547   // Thread's fields layout the same.
 548   // Note: CHECK_UNHANDLED_OOPS is defined only for fastdebug build.
 549 #ifdef CHECK_UNHANDLED_OOPS
 550  private:
 551   UnhandledOops* _unhandled_oops;
 552 #elif defined(ASSERT)
 553  private:
 554   void* _unhandled_oops;
 555 #endif
 556 #ifdef CHECK_UNHANDLED_OOPS
 557  public:
 558   UnhandledOops* unhandled_oops() { return _unhandled_oops; }
 559   // Mark oop safe for gc.  It may be stack allocated but won't move.
 560   void allow_unhandled_oop(oop *op) {
 561     if (CheckUnhandledOops) unhandled_oops()->allow_unhandled_oop(op);
 562   }
 563   // Clear oops at safepoint so crashes point to unhandled oop violator
 564   void clear_unhandled_oops() {
 565     if (CheckUnhandledOops) unhandled_oops()->clear_unhandled_oops();
 566   }
 567 #endif // CHECK_UNHANDLED_OOPS
 568 
 569  public:
 570 #ifndef PRODUCT
 571   bool skip_gcalot()           { return _skip_gcalot; }
 572   void set_skip_gcalot(bool v) { _skip_gcalot = v;    }
 573 #endif
 574 
 575   // Installs a pending exception to be inserted later
 576   static void send_async_exception(oop thread_oop, oop java_throwable);
 577 
 578   // Resource area
 579   ResourceArea* resource_area() const            { return _resource_area; }
 580   void set_resource_area(ResourceArea* area)     { _resource_area = area; }
 581 
 582   OSThread* osthread() const                     { return _osthread;   }
 583   void set_osthread(OSThread* thread)            { _osthread = thread; }
 584 
 585   // JNI handle support
 586   JNIHandleBlock* active_handles() const         { return _active_handles; }
 587   void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
 588   JNIHandleBlock* free_handle_block() const      { return _free_handle_block; }
 589   void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
 590 
 591   // Internal handle support
 592   HandleArea* handle_area() const                { return _handle_area; }
 593   void set_handle_area(HandleArea* area)         { _handle_area = area; }
 594 
 595   GrowableArray<Metadata*>* metadata_handles() const          { return _metadata_handles; }
 596   void set_metadata_handles(GrowableArray<Metadata*>* handles){ _metadata_handles = handles; }
 597 
 598   // Thread-Local Allocation Buffer (TLAB) support
 599   ThreadLocalAllocBuffer& tlab()                 { return _tlab; }
 600   void initialize_tlab() {
 601     if (UseTLAB) {
 602       tlab().initialize();
 603     }
 604   }
 605 
 606   jlong allocated_bytes()               { return _allocated_bytes; }
 607   void set_allocated_bytes(jlong value) { _allocated_bytes = value; }
 608   void incr_allocated_bytes(jlong size) { _allocated_bytes += size; }
 609   inline jlong cooked_allocated_bytes();
 610 
 611   ThreadHeapSampler& heap_sampler()     { return _heap_sampler; }
 612 
 613   ThreadStatisticalInfo& statistical_info() { return _statistical_info; }
 614 
 615   JFR_ONLY(DEFINE_THREAD_LOCAL_ACCESSOR_JFR;)
 616 
 617   bool is_trace_suspend()               { return (_suspend_flags & _trace_flag) != 0; }
 618 
 619   // VM operation support
 620   int vm_operation_ticket()                      { return ++_vm_operation_started_count; }
 621   int vm_operation_completed_count()             { return _vm_operation_completed_count; }
 622   void increment_vm_operation_completed_count()  { _vm_operation_completed_count++; }
 623 
 624   // For tracking the heavyweight monitor the thread is pending on.
 625   ObjectMonitor* current_pending_monitor() {
 626     return _current_pending_monitor;
 627   }
 628   void set_current_pending_monitor(ObjectMonitor* monitor) {
 629     _current_pending_monitor = monitor;
 630   }
 631   void set_current_pending_monitor_is_from_java(bool from_java) {
 632     _current_pending_monitor_is_from_java = from_java;
 633   }
 634   bool current_pending_monitor_is_from_java() {
 635     return _current_pending_monitor_is_from_java;
 636   }
 637 
 638   // For tracking the ObjectMonitor on which this thread called Object.wait()
 639   ObjectMonitor* current_waiting_monitor() {
 640     return _current_waiting_monitor;
 641   }
 642   void set_current_waiting_monitor(ObjectMonitor* monitor) {
 643     _current_waiting_monitor = monitor;
 644   }
 645 
 646   // For tracking the Jvmti raw monitor the thread is pending on.
 647   JvmtiRawMonitor* current_pending_raw_monitor() {
 648     return _current_pending_raw_monitor;
 649   }
 650   void set_current_pending_raw_monitor(JvmtiRawMonitor* monitor) {
 651     _current_pending_raw_monitor = monitor;
 652   }
 653 
 654   // GC support
 655   // Apply "f->do_oop" to all root oops in "this".
 656   //   Used by JavaThread::oops_do.
 657   // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames
 658   virtual void oops_do(OopClosure* f, CodeBlobClosure* cf);
 659 
 660   // Handles the parallel case for claim_threads_do.
 661  private:
 662   bool claim_par_threads_do(uintx claim_token);
 663  public:
 664   // Requires that "claim_token" is that of the current iteration.
 665   // If "is_par" is false, sets the token of "this" to
 666   // "claim_token", and returns "true".  If "is_par" is true,
 667   // uses an atomic instruction to set the current thread's token to
 668   // "claim_token", if it is not already.  Returns "true" iff the
 669   // calling thread does the update, this indicates that the calling thread
 670   // has claimed the thread in the current iteration.
 671   bool claim_threads_do(bool is_par, uintx claim_token) {
 672     if (!is_par) {
 673       _threads_do_token = claim_token;
 674       return true;
 675     } else {
 676       return claim_par_threads_do(claim_token);
 677     }
 678   }
 679 
 680   uintx threads_do_token() const { return _threads_do_token; }
 681 
 682   // jvmtiRedefineClasses support
 683   void metadata_handles_do(void f(Metadata*));
 684 
 685   // Used by fast lock support
 686   virtual bool is_lock_owned(address adr) const;
 687 
 688   // Check if address is in the stack of the thread (not just for locks).
 689   // Warning: the method can only be used on the running thread
 690   bool is_in_stack(address adr) const;
 691   // Check if address is in the usable part of the stack (excludes protected
 692   // guard pages)
 693   bool is_in_usable_stack(address adr) const;
 694 
 695   // Sets this thread as starting thread. Returns failure if thread
 696   // creation fails due to lack of memory, too many threads etc.
 697   bool set_as_starting_thread();
 698 
 699 protected:
 700   // OS data associated with the thread
 701   OSThread* _osthread;  // Platform-specific thread information
 702 
 703   // Thread local resource area for temporary allocation within the VM
 704   ResourceArea* _resource_area;
 705 
 706   DEBUG_ONLY(ResourceMark* _current_resource_mark;)
 707 
 708   // Thread local handle area for allocation of handles within the VM
 709   HandleArea* _handle_area;
 710   GrowableArray<Metadata*>* _metadata_handles;
 711 
 712   // Support for stack overflow handling, get_thread, etc.
 713   address          _stack_base;
 714   size_t           _stack_size;
 715   int              _lgrp_id;
 716 
 717   volatile void** polling_page_addr() { return &_polling_page; }
 718 
 719  public:
 720   // Stack overflow support
 721   address stack_base() const           { assert(_stack_base != NULL,"Sanity check"); return _stack_base; }
 722   void    set_stack_base(address base) { _stack_base = base; }
 723   size_t  stack_size() const           { return _stack_size; }
 724   void    set_stack_size(size_t size)  { _stack_size = size; }
 725   address stack_end()  const           { return stack_base() - stack_size(); }
 726   void    record_stack_base_and_size();
 727   void    register_thread_stack_with_NMT() NOT_NMT_RETURN;
 728 
 729   bool    on_local_stack(address adr) const {
 730     // QQQ this has knowledge of direction, ought to be a stack method
 731     return (_stack_base >= adr && adr >= stack_end());
 732   }
 733 
 734   int     lgrp_id() const        { return _lgrp_id; }
 735   void    set_lgrp_id(int value) { _lgrp_id = value; }
 736 
 737   // Printing
 738   void print_on(outputStream* st, bool print_extended_info) const;
 739   virtual void print_on(outputStream* st) const { print_on(st, false); }
 740   void print() const;
 741   virtual void print_on_error(outputStream* st, char* buf, int buflen) const;
 742   void print_value_on(outputStream* st) const;
 743 
 744   // Debug-only code
 745 #ifdef ASSERT
 746  private:
 747   // Deadlock detection support for Mutex locks. List of locks own by thread.
 748   Mutex* _owned_locks;
 749   // Mutex::set_owner_implementation is the only place where _owned_locks is modified,
 750   // thus the friendship
 751   friend class Mutex;
 752   friend class Monitor;
 753 
 754  public:
 755   void print_owned_locks_on(outputStream* st) const;
 756   void print_owned_locks() const                 { print_owned_locks_on(tty);    }
 757   Mutex* owned_locks() const                     { return _owned_locks;          }
 758   bool owns_locks() const                        { return owned_locks() != NULL; }
 759 
 760   // Deadlock detection
 761   ResourceMark* current_resource_mark()          { return _current_resource_mark; }
 762   void set_current_resource_mark(ResourceMark* rm) { _current_resource_mark = rm; }
 763 #endif // ASSERT
 764 
 765   // These functions check conditions on a JavaThread before possibly going to a safepoint,
 766   // including NoSafepointVerifier.
 767   void check_for_valid_safepoint_state() NOT_DEBUG_RETURN;
 768   void check_possible_safepoint() NOT_DEBUG_RETURN;
 769 
 770  private:
 771   volatile int _jvmti_env_iteration_count;
 772 
 773  public:
 774   void entering_jvmti_env_iteration()            { ++_jvmti_env_iteration_count; }
 775   void leaving_jvmti_env_iteration()             { --_jvmti_env_iteration_count; }
 776   bool is_inside_jvmti_env_iteration()           { return _jvmti_env_iteration_count > 0; }
 777 
 778   // Code generation
 779   static ByteSize exception_file_offset()        { return byte_offset_of(Thread, _exception_file); }
 780   static ByteSize exception_line_offset()        { return byte_offset_of(Thread, _exception_line); }
 781   static ByteSize active_handles_offset()        { return byte_offset_of(Thread, _active_handles); }
 782 
 783   static ByteSize stack_base_offset()            { return byte_offset_of(Thread, _stack_base); }
 784   static ByteSize stack_size_offset()            { return byte_offset_of(Thread, _stack_size); }
 785 
 786   static ByteSize polling_page_offset()          { return byte_offset_of(Thread, _polling_page); }
 787 
 788   static ByteSize tlab_start_offset()            { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::start_offset(); }
 789   static ByteSize tlab_end_offset()              { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::end_offset(); }
 790   static ByteSize tlab_top_offset()              { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::top_offset(); }
 791   static ByteSize tlab_pf_top_offset()           { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::pf_top_offset(); }
 792 
 793   static ByteSize allocated_bytes_offset()       { return byte_offset_of(Thread, _allocated_bytes); }
 794 
 795   JFR_ONLY(DEFINE_THREAD_LOCAL_OFFSET_JFR;)
 796 
 797  public:
 798   volatile intptr_t _Stalled;
 799   volatile int _TypeTag;
 800   ParkEvent * _ParkEvent;                     // for Object monitors and JVMTI raw monitors
 801   ParkEvent * _MuxEvent;                      // for low-level muxAcquire-muxRelease
 802   int NativeSyncRecursion;                    // diagnostic
 803 
 804   volatile int _OnTrap;                       // Resume-at IP delta
 805   jint _hashStateW;                           // Marsaglia Shift-XOR thread-local RNG
 806   jint _hashStateX;                           // thread-specific hashCode generator state
 807   jint _hashStateY;
 808   jint _hashStateZ;
 809 
 810   // Low-level leaf-lock primitives used to implement synchronization
 811   // and native monitor-mutex infrastructure.
 812   // Not for general synchronization use.
 813   static void SpinAcquire(volatile int * Lock, const char * Name);
 814   static void SpinRelease(volatile int * Lock);
 815   static void muxAcquire(volatile intptr_t * Lock, const char * Name);
 816   static void muxRelease(volatile intptr_t * Lock);
 817 };
 818 
 819 // Inline implementation of Thread::current()
 820 inline Thread* Thread::current() {
 821   Thread* current = current_or_null();
 822   assert(current != NULL, "Thread::current() called on detached thread");
 823   return current;
 824 }
 825 
 826 inline Thread* Thread::current_or_null() {
 827 #ifndef USE_LIBRARY_BASED_TLS_ONLY
 828   return _thr_current;
 829 #else
 830   if (ThreadLocalStorage::is_initialized()) {
 831     return ThreadLocalStorage::thread();
 832   }
 833   return NULL;
 834 #endif
 835 }
 836 
 837 inline Thread* Thread::current_or_null_safe() {
 838   if (ThreadLocalStorage::is_initialized()) {
 839     return ThreadLocalStorage::thread();
 840   }
 841   return NULL;
 842 }
 843 
 844 class NonJavaThread: public Thread {
 845   friend class VMStructs;
 846 
 847   NonJavaThread* volatile _next;
 848 
 849   class List;
 850   static List _the_list;
 851 
 852   void add_to_the_list();
 853   void remove_from_the_list();
 854 
 855  protected:
 856   virtual void pre_run();
 857   virtual void post_run();
 858 
 859  public:
 860   NonJavaThread();
 861   ~NonJavaThread();
 862 
 863   class Iterator;
 864 };
 865 
 866 // Provides iteration over the list of NonJavaThreads.
 867 // List addition occurs in pre_run(), and removal occurs in post_run(),
 868 // so that only live fully-initialized threads can be found in the list.
 869 // Threads created after an iterator is constructed will not be visited
 870 // by the iterator. The scope of an iterator is a critical section; there
 871 // must be no safepoint checks in that scope.
 872 class NonJavaThread::Iterator : public StackObj {
 873   uint _protect_enter;
 874   NonJavaThread* _current;
 875 
 876   // Noncopyable.
 877   Iterator(const Iterator&);
 878   Iterator& operator=(const Iterator&);
 879 
 880 public:
 881   Iterator();
 882   ~Iterator();
 883 
 884   bool end() const { return _current == NULL; }
 885   NonJavaThread* current() const { return _current; }
 886   void step();
 887 };
 888 
 889 // Name support for threads.  non-JavaThread subclasses with multiple
 890 // uniquely named instances should derive from this.
 891 class NamedThread: public NonJavaThread {
 892   friend class VMStructs;
 893   enum {
 894     max_name_len = 64
 895   };
 896  private:
 897   char* _name;
 898   // log JavaThread being processed by oops_do
 899   JavaThread* _processed_thread;
 900   uint _gc_id; // The current GC id when a thread takes part in GC
 901 
 902  public:
 903   NamedThread();
 904   ~NamedThread();
 905   // May only be called once per thread.
 906   void set_name(const char* format, ...)  ATTRIBUTE_PRINTF(2, 3);
 907   virtual bool is_Named_thread() const { return true; }
 908   virtual char* name() const { return _name == NULL ? (char*)"Unknown Thread" : _name; }
 909   JavaThread *processed_thread() { return _processed_thread; }
 910   void set_processed_thread(JavaThread *thread) { _processed_thread = thread; }
 911   virtual void print_on(outputStream* st) const;
 912 
 913   void set_gc_id(uint gc_id) { _gc_id = gc_id; }
 914   uint gc_id() { return _gc_id; }
 915 };
 916 
 917 // Worker threads are named and have an id of an assigned work.
 918 class WorkerThread: public NamedThread {
 919  private:
 920   uint _id;
 921  public:
 922   WorkerThread() : _id(0)               { }
 923   virtual bool is_Worker_thread() const { return true; }
 924 
 925   virtual WorkerThread* as_Worker_thread() const {
 926     assert(is_Worker_thread(), "Dubious cast to WorkerThread*?");
 927     return (WorkerThread*) this;
 928   }
 929 
 930   void set_id(uint work_id)             { _id = work_id; }
 931   uint id() const                       { return _id; }
 932 };
 933 
 934 // A single WatcherThread is used for simulating timer interrupts.
 935 class WatcherThread: public NonJavaThread {
 936   friend class VMStructs;
 937  protected:
 938   virtual void run();
 939 
 940  private:
 941   static WatcherThread* _watcher_thread;
 942 
 943   static bool _startable;
 944   // volatile due to at least one lock-free read
 945   volatile static bool _should_terminate;
 946  public:
 947   enum SomeConstants {
 948     delay_interval = 10                          // interrupt delay in milliseconds
 949   };
 950 
 951   // Constructor
 952   WatcherThread();
 953 
 954   // No destruction allowed
 955   ~WatcherThread() {
 956     guarantee(false, "WatcherThread deletion must fix the race with VM termination");
 957   }
 958 
 959   // Tester
 960   bool is_Watcher_thread() const                 { return true; }
 961 
 962   // Printing
 963   char* name() const { return (char*)"VM Periodic Task Thread"; }
 964   void print_on(outputStream* st) const;
 965   void unpark();
 966 
 967   // Returns the single instance of WatcherThread
 968   static WatcherThread* watcher_thread()         { return _watcher_thread; }
 969 
 970   // Create and start the single instance of WatcherThread, or stop it on shutdown
 971   static void start();
 972   static void stop();
 973   // Only allow start once the VM is sufficiently initialized
 974   // Otherwise the first task to enroll will trigger the start
 975   static void make_startable();
 976  private:
 977   int sleep() const;
 978 };
 979 
 980 
 981 class CompilerThread;
 982 
 983 typedef void (*ThreadFunction)(JavaThread*, TRAPS);
 984 
 985 class JavaThread: public Thread {
 986   friend class VMStructs;
 987   friend class JVMCIVMStructs;
 988   friend class WhiteBox;
 989  private:
 990   bool           _on_thread_list;                // Is set when this JavaThread is added to the Threads list
 991   oop            _threadObj;                     // The Java level thread object
 992 
 993 #ifdef ASSERT
 994  private:
 995   int _java_call_counter;
 996 
 997  public:
 998   int  java_call_counter()                       { return _java_call_counter; }
 999   void inc_java_call_counter()                   { _java_call_counter++; }
1000   void dec_java_call_counter() {
1001     assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
1002     _java_call_counter--;
1003   }
1004  private:  // restore original namespace restriction
1005 #endif  // ifdef ASSERT
1006 
1007 #ifndef PRODUCT
1008  public:
1009   enum {
1010     jump_ring_buffer_size = 16
1011   };
1012  private:  // restore original namespace restriction
1013 #endif
1014 
1015   JavaFrameAnchor _anchor;                       // Encapsulation of current java frame and it state
1016 
1017   ThreadFunction _entry_point;
1018 
1019   JNIEnv        _jni_environment;
1020 
1021   // Deopt support
1022   DeoptResourceMark*  _deopt_mark;               // Holds special ResourceMark for deoptimization
1023 
1024   CompiledMethod*       _deopt_nmethod;         // CompiledMethod that is currently being deoptimized
1025   vframeArray*  _vframe_array_head;              // Holds the heap of the active vframeArrays
1026   vframeArray*  _vframe_array_last;              // Holds last vFrameArray we popped
1027   // Because deoptimization is lazy we must save jvmti requests to set locals
1028   // in compiled frames until we deoptimize and we have an interpreter frame.
1029   // This holds the pointer to array (yeah like there might be more than one) of
1030   // description of compiled vframes that have locals that need to be updated.
1031   GrowableArray<jvmtiDeferredLocalVariableSet*>* _deferred_locals_updates;
1032 
1033   // Handshake value for fixing 6243940. We need a place for the i2c
1034   // adapter to store the callee Method*. This value is NEVER live
1035   // across a gc point so it does NOT have to be gc'd
1036   // The handshake is open ended since we can't be certain that it will
1037   // be NULLed. This is because we rarely ever see the race and end up
1038   // in handle_wrong_method which is the backend of the handshake. See
1039   // code in i2c adapters and handle_wrong_method.
1040 
1041   Method*       _callee_target;
1042 
1043   // Used to pass back results to the interpreter or generated code running Java code.
1044   oop           _vm_result;    // oop result is GC-preserved
1045   Metadata*     _vm_result_2;  // non-oop result
1046 
1047   // See ReduceInitialCardMarks: this holds the precise space interval of
1048   // the most recent slow path allocation for which compiled code has
1049   // elided card-marks for performance along the fast-path.
1050   MemRegion     _deferred_card_mark;
1051 
1052   MonitorChunk* _monitor_chunks;                 // Contains the off stack monitors
1053                                                  // allocated during deoptimization
1054                                                  // and by JNI_MonitorEnter/Exit
1055 
1056   // Async. requests support
1057   enum AsyncRequests {
1058     _no_async_condition = 0,
1059     _async_exception,
1060     _async_unsafe_access_error
1061   };
1062   AsyncRequests _special_runtime_exit_condition; // Enum indicating pending async. request
1063   oop           _pending_async_exception;
1064 
1065   // Safepoint support
1066  public:                                         // Expose _thread_state for SafeFetchInt()
1067   volatile JavaThreadState _thread_state;
1068  private:
1069   ThreadSafepointState* _safepoint_state;        // Holds information about a thread during a safepoint
1070   address               _saved_exception_pc;     // Saved pc of instruction where last implicit exception happened
1071 
1072   // JavaThread termination support
1073   enum TerminatedTypes {
1074     _not_terminated = 0xDEAD - 2,
1075     _thread_exiting,                             // JavaThread::exit() has been called for this thread
1076     _thread_terminated,                          // JavaThread is removed from thread list
1077     _vm_exited                                   // JavaThread is still executing native code, but VM is terminated
1078                                                  // only VM_Exit can set _vm_exited
1079   };
1080 
1081   // In general a JavaThread's _terminated field transitions as follows:
1082   //
1083   //   _not_terminated => _thread_exiting => _thread_terminated
1084   //
1085   // _vm_exited is a special value to cover the case of a JavaThread
1086   // executing native code after the VM itself is terminated.
1087   volatile TerminatedTypes _terminated;
1088   // suspend/resume support
1089   volatile bool         _suspend_equivalent;     // Suspend equivalent condition
1090   jint                  _in_deopt_handler;       // count of deoptimization
1091                                                  // handlers thread is in
1092   volatile bool         _doing_unsafe_access;    // Thread may fault due to unsafe access
1093   bool                  _do_not_unlock_if_synchronized;  // Do not unlock the receiver of a synchronized method (since it was
1094                                                          // never locked) when throwing an exception. Used by interpreter only.
1095 
1096   // JNI attach states:
1097   enum JNIAttachStates {
1098     _not_attaching_via_jni = 1,  // thread is not attaching via JNI
1099     _attaching_via_jni,          // thread is attaching via JNI
1100     _attached_via_jni            // thread has attached via JNI
1101   };
1102 
1103   // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
1104   // A native thread that is attaching via JNI starts with a value
1105   // of _attaching_via_jni and transitions to _attached_via_jni.
1106   volatile JNIAttachStates _jni_attach_state;
1107 
1108  public:
1109   // State of the stack guard pages for this thread.
1110   enum StackGuardState {
1111     stack_guard_unused,         // not needed
1112     stack_guard_reserved_disabled,
1113     stack_guard_yellow_reserved_disabled,// disabled (temporarily) after stack overflow
1114     stack_guard_enabled         // enabled
1115   };
1116 
1117  private:
1118 
1119 #if INCLUDE_JVMCI
1120   // The _pending_* fields below are used to communicate extra information
1121   // from an uncommon trap in JVMCI compiled code to the uncommon trap handler.
1122 
1123   // Communicates the DeoptReason and DeoptAction of the uncommon trap
1124   int       _pending_deoptimization;
1125 
1126   // Specifies whether the uncommon trap is to bci 0 of a synchronized method
1127   // before the monitor has been acquired.
1128   bool      _pending_monitorenter;
1129 
1130   // Specifies if the DeoptReason for the last uncommon trap was Reason_transfer_to_interpreter
1131   bool      _pending_transfer_to_interpreter;
1132 
1133   // True if in a runtime call from compiled code that will deoptimize
1134   // and re-execute a failed heap allocation in the interpreter.
1135   bool      _in_retryable_allocation;
1136 
1137   // An id of a speculation that JVMCI compiled code can use to further describe and
1138   // uniquely identify the  speculative optimization guarded by the uncommon trap
1139   jlong     _pending_failed_speculation;
1140 
1141   // These fields are mutually exclusive in terms of live ranges.
1142   union {
1143     // Communicates the pc at which the most recent implicit exception occurred
1144     // from the signal handler to a deoptimization stub.
1145     address   _implicit_exception_pc;
1146 
1147     // Communicates an alternative call target to an i2c stub from a JavaCall .
1148     address   _alternate_call_target;
1149   } _jvmci;
1150 
1151   // Support for high precision, thread sensitive counters in JVMCI compiled code.
1152   jlong*    _jvmci_counters;
1153 
1154  public:
1155   static jlong* _jvmci_old_thread_counters;
1156   static void collect_counters(jlong* array, int length);
1157   void resize_counters(int current_size, int new_size);
1158   static void resize_all_jvmci_counters(int new_size);
1159 
1160  private:
1161 #endif // INCLUDE_JVMCI
1162 
1163   StackGuardState  _stack_guard_state;
1164 
1165   // Precompute the limit of the stack as used in stack overflow checks.
1166   // We load it from here to simplify the stack overflow check in assembly.
1167   address          _stack_overflow_limit;
1168   address          _reserved_stack_activation;
1169 
1170   // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
1171   // used to temp. parsing values into and out of the runtime system during exception handling for compiled
1172   // code)
1173   volatile oop     _exception_oop;               // Exception thrown in compiled code
1174   volatile address _exception_pc;                // PC where exception happened
1175   volatile address _exception_handler_pc;        // PC for handler of exception
1176   volatile int     _is_method_handle_return;     // true (== 1) if the current exception PC is a MethodHandle call site.
1177 
1178  private:
1179   // support for JNI critical regions
1180   jint    _jni_active_critical;                  // count of entries into JNI critical region
1181 
1182   // Checked JNI: function name requires exception check
1183   char* _pending_jni_exception_check_fn;
1184 
1185   // For deadlock detection.
1186   int _depth_first_number;
1187 
1188   // JVMTI PopFrame support
1189   // This is set to popframe_pending to signal that top Java frame should be popped immediately
1190   int _popframe_condition;
1191 
1192   // If reallocation of scalar replaced objects fails, we throw OOM
1193   // and during exception propagation, pop the top
1194   // _frames_to_pop_failed_realloc frames, the ones that reference
1195   // failed reallocations.
1196   int _frames_to_pop_failed_realloc;
1197 
1198   friend class VMThread;
1199   friend class ThreadWaitTransition;
1200   friend class VM_Exit;
1201 
1202   void initialize();                             // Initialized the instance variables
1203 
1204  public:
1205   // Constructor
1206   JavaThread(bool is_attaching_via_jni = false); // for main thread and JNI attached threads
1207   JavaThread(ThreadFunction entry_point, size_t stack_size = 0);
1208   ~JavaThread();
1209 
1210 #ifdef ASSERT
1211   // verify this JavaThread hasn't be published in the Threads::list yet
1212   void verify_not_published();
1213 #endif // ASSERT
1214 
1215   //JNI functiontable getter/setter for JVMTI jni function table interception API.
1216   void set_jni_functions(struct JNINativeInterface_* functionTable) {
1217     _jni_environment.functions = functionTable;
1218   }
1219   struct JNINativeInterface_* get_jni_functions() {
1220     return (struct JNINativeInterface_ *)_jni_environment.functions;
1221   }
1222 
1223   // This function is called at thread creation to allow
1224   // platform specific thread variables to be initialized.
1225   void cache_global_variables();
1226 
1227   // Executes Shutdown.shutdown()
1228   void invoke_shutdown_hooks();
1229 
1230   // Cleanup on thread exit
1231   enum ExitType {
1232     normal_exit,
1233     jni_detach
1234   };
1235   void exit(bool destroy_vm, ExitType exit_type = normal_exit);
1236 
1237   void cleanup_failed_attach_current_thread(bool is_daemon);
1238 
1239   // Testers
1240   virtual bool is_Java_thread() const            { return true;  }
1241   virtual bool can_call_java() const             { return true; }
1242 
1243   virtual bool is_active_Java_thread() const {
1244     return on_thread_list() && !is_terminated();
1245   }
1246 
1247   // Thread oop. threadObj() can be NULL for initial JavaThread
1248   // (or for threads attached via JNI)
1249   oop threadObj() const                          { return _threadObj; }
1250   void set_threadObj(oop p)                      { _threadObj = p; }
1251 
1252   // Prepare thread and add to priority queue.  If a priority is
1253   // not specified, use the priority of the thread object. Threads_lock
1254   // must be held while this function is called.
1255   void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
1256 
1257   void set_saved_exception_pc(address pc)        { _saved_exception_pc = pc; }
1258   address saved_exception_pc()                   { return _saved_exception_pc; }
1259 
1260 
1261   ThreadFunction entry_point() const             { return _entry_point; }
1262 
1263   // Allocates a new Java level thread object for this thread. thread_name may be NULL.
1264   void allocate_threadObj(Handle thread_group, const char* thread_name, bool daemon, TRAPS);
1265 
1266   // Last frame anchor routines
1267 
1268   JavaFrameAnchor* frame_anchor(void)            { return &_anchor; }
1269 
1270   // last_Java_sp
1271   bool has_last_Java_frame() const               { return _anchor.has_last_Java_frame(); }
1272   intptr_t* last_Java_sp() const                 { return _anchor.last_Java_sp(); }
1273 
1274   // last_Java_pc
1275 
1276   address last_Java_pc(void)                     { return _anchor.last_Java_pc(); }
1277 
1278   // Safepoint support
1279   inline JavaThreadState thread_state() const;
1280   inline void set_thread_state(JavaThreadState s);
1281   inline void set_thread_state_fence(JavaThreadState s);  // fence after setting thread state
1282   inline ThreadSafepointState* safepoint_state() const;
1283   inline void set_safepoint_state(ThreadSafepointState* state);
1284   inline bool is_at_poll_safepoint();
1285 
1286   // JavaThread termination and lifecycle support:
1287   void smr_delete();
1288   bool on_thread_list() const { return _on_thread_list; }
1289   void set_on_thread_list() { _on_thread_list = true; }
1290 
1291   // thread has called JavaThread::exit() or is terminated
1292   bool is_exiting() const;
1293   // thread is terminated (no longer on the threads list); we compare
1294   // against the two non-terminated values so that a freed JavaThread
1295   // will also be considered terminated.
1296   bool check_is_terminated(TerminatedTypes l_terminated) const {
1297     return l_terminated != _not_terminated && l_terminated != _thread_exiting;
1298   }
1299   bool is_terminated() const;
1300   void set_terminated(TerminatedTypes t);
1301   // special for Threads::remove() which is static:
1302   void set_terminated_value();
1303   void block_if_vm_exited();
1304 
1305   bool doing_unsafe_access()                     { return _doing_unsafe_access; }
1306   void set_doing_unsafe_access(bool val)         { _doing_unsafe_access = val; }
1307 
1308   bool do_not_unlock_if_synchronized()             { return _do_not_unlock_if_synchronized; }
1309   void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
1310 
1311   inline void set_polling_page_release(void* poll_value);
1312   inline void set_polling_page(void* poll_value);
1313   inline volatile void* get_polling_page();
1314 
1315  private:
1316   // Support for thread handshake operations
1317   HandshakeState _handshake;
1318  public:
1319   void set_handshake_operation(HandshakeOperation* op) {
1320     _handshake.set_operation(this, op);
1321   }
1322 
1323   bool has_handshake() const {
1324     return _handshake.has_operation();
1325   }
1326 
1327   void handshake_process_by_self() {
1328     _handshake.process_by_self(this);
1329   }
1330 
1331   void handshake_process_by_vmthread() {
1332     _handshake.process_by_vmthread(this);
1333   }
1334 
1335   // Suspend/resume support for JavaThread
1336  private:
1337   inline void set_ext_suspended();
1338   inline void clear_ext_suspended();
1339 
1340  public:
1341   void java_suspend(); // higher-level suspension logic called by the public APIs
1342   void java_resume();  // higher-level resume logic called by the public APIs
1343   int  java_suspend_self(); // low-level self-suspension mechanics
1344 
1345  private:
1346   // mid-level wrapper around java_suspend_self to set up correct state and
1347   // check for a pending safepoint at the end
1348   void java_suspend_self_with_safepoint_check();
1349 
1350  public:
1351   void check_and_wait_while_suspended() {
1352     assert(JavaThread::current() == this, "sanity check");
1353 
1354     bool do_self_suspend;
1355     do {
1356       // were we externally suspended while we were waiting?
1357       do_self_suspend = handle_special_suspend_equivalent_condition();
1358       if (do_self_suspend) {
1359         // don't surprise the thread that suspended us by returning
1360         java_suspend_self();
1361         set_suspend_equivalent();
1362       }
1363     } while (do_self_suspend);
1364   }
1365   static void check_safepoint_and_suspend_for_native_trans(JavaThread *thread);
1366   // Check for async exception in addition to safepoint and suspend request.
1367   static void check_special_condition_for_native_trans(JavaThread *thread);
1368 
1369   // Same as check_special_condition_for_native_trans but finishes the
1370   // transition into thread_in_Java mode so that it can potentially
1371   // block.
1372   static void check_special_condition_for_native_trans_and_transition(JavaThread *thread);
1373 
1374   bool is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits);
1375   bool is_ext_suspend_completed_with_lock(uint32_t *bits) {
1376     MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1377     // Warning: is_ext_suspend_completed() may temporarily drop the
1378     // SR_lock to allow the thread to reach a stable thread state if
1379     // it is currently in a transient thread state.
1380     return is_ext_suspend_completed(false /* !called_by_wait */,
1381                                     SuspendRetryDelay, bits);
1382   }
1383 
1384   // We cannot allow wait_for_ext_suspend_completion() to run forever or
1385   // we could hang. SuspendRetryCount and SuspendRetryDelay are normally
1386   // passed as the count and delay parameters. Experiments with specific
1387   // calls to wait_for_ext_suspend_completion() can be done by passing
1388   // other values in the code. Experiments with all calls can be done
1389   // via the appropriate -XX options.
1390   bool wait_for_ext_suspend_completion(int count, int delay, uint32_t *bits);
1391 
1392   // test for suspend - most (all?) of these should go away
1393   bool is_thread_fully_suspended(bool wait_for_suspend, uint32_t *bits);
1394 
1395   inline void set_external_suspend();
1396   inline void clear_external_suspend();
1397 
1398   bool is_external_suspend() const {
1399     return (_suspend_flags & _external_suspend) != 0;
1400   }
1401   // Whenever a thread transitions from native to vm/java it must suspend
1402   // if external|deopt suspend is present.
1403   bool is_suspend_after_native() const {
1404     return (_suspend_flags & (_external_suspend JFR_ONLY(| _trace_flag))) != 0;
1405   }
1406 
1407   // external suspend request is completed
1408   bool is_ext_suspended() const {
1409     return (_suspend_flags & _ext_suspended) != 0;
1410   }
1411 
1412   bool is_external_suspend_with_lock() const {
1413     MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1414     return is_external_suspend();
1415   }
1416 
1417   // Special method to handle a pending external suspend request
1418   // when a suspend equivalent condition lifts.
1419   bool handle_special_suspend_equivalent_condition() {
1420     assert(is_suspend_equivalent(),
1421            "should only be called in a suspend equivalence condition");
1422     MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1423     bool ret = is_external_suspend();
1424     if (!ret) {
1425       // not about to self-suspend so clear suspend equivalence
1426       clear_suspend_equivalent();
1427     }
1428     // implied else:
1429     // We have a pending external suspend request so we leave the
1430     // suspend_equivalent flag set until java_suspend_self() sets
1431     // the ext_suspended flag and clears the suspend_equivalent
1432     // flag. This insures that wait_for_ext_suspend_completion()
1433     // will return consistent values.
1434     return ret;
1435   }
1436 
1437   // utility methods to see if we are doing some kind of suspension
1438   bool is_being_ext_suspended() const            {
1439     MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1440     return is_ext_suspended() || is_external_suspend();
1441   }
1442 
1443   bool is_suspend_equivalent() const             { return _suspend_equivalent; }
1444 
1445   void set_suspend_equivalent()                  { _suspend_equivalent = true; }
1446   void clear_suspend_equivalent()                { _suspend_equivalent = false; }
1447 
1448   // Thread.stop support
1449   void send_thread_stop(oop throwable);
1450   AsyncRequests clear_special_runtime_exit_condition() {
1451     AsyncRequests x = _special_runtime_exit_condition;
1452     _special_runtime_exit_condition = _no_async_condition;
1453     return x;
1454   }
1455 
1456   // Are any async conditions present?
1457   bool has_async_condition() { return (_special_runtime_exit_condition != _no_async_condition); }
1458 
1459   void check_and_handle_async_exceptions(bool check_unsafe_error = true);
1460 
1461   // these next two are also used for self-suspension and async exception support
1462   void handle_special_runtime_exit_condition(bool check_asyncs = true);
1463 
1464   // Return true if JavaThread has an asynchronous condition or
1465   // if external suspension is requested.
1466   bool has_special_runtime_exit_condition() {
1467     // Because we don't use is_external_suspend_with_lock
1468     // it is possible that we won't see an asynchronous external suspend
1469     // request that has just gotten started, i.e., SR_lock grabbed but
1470     // _external_suspend field change either not made yet or not visible
1471     // yet. However, this is okay because the request is asynchronous and
1472     // we will see the new flag value the next time through. It's also
1473     // possible that the external suspend request is dropped after
1474     // we have checked is_external_suspend(), we will recheck its value
1475     // under SR_lock in java_suspend_self().
1476     return (_special_runtime_exit_condition != _no_async_condition) ||
1477             is_external_suspend() || is_trace_suspend();
1478   }
1479 
1480   void set_pending_unsafe_access_error()          { _special_runtime_exit_condition = _async_unsafe_access_error; }
1481 
1482   inline void set_pending_async_exception(oop e);
1483 
1484   // Fast-locking support
1485   bool is_lock_owned(address adr) const;
1486 
1487   // Accessors for vframe array top
1488   // The linked list of vframe arrays are sorted on sp. This means when we
1489   // unpack the head must contain the vframe array to unpack.
1490   void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
1491   vframeArray* vframe_array_head() const         { return _vframe_array_head;  }
1492 
1493   // Side structure for deferring update of java frame locals until deopt occurs
1494   GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred_locals() const { return _deferred_locals_updates; }
1495   void set_deferred_locals(GrowableArray<jvmtiDeferredLocalVariableSet *>* vf) { _deferred_locals_updates = vf; }
1496 
1497   // These only really exist to make debugging deopt problems simpler
1498 
1499   void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
1500   vframeArray* vframe_array_last() const         { return _vframe_array_last;  }
1501 
1502   // The special resourceMark used during deoptimization
1503 
1504   void set_deopt_mark(DeoptResourceMark* value)  { _deopt_mark = value; }
1505   DeoptResourceMark* deopt_mark(void)            { return _deopt_mark; }
1506 
1507   void set_deopt_compiled_method(CompiledMethod* nm)  { _deopt_nmethod = nm; }
1508   CompiledMethod* deopt_compiled_method()        { return _deopt_nmethod; }
1509 
1510   Method*    callee_target() const               { return _callee_target; }
1511   void set_callee_target  (Method* x)          { _callee_target   = x; }
1512 
1513   // Oop results of vm runtime calls
1514   oop  vm_result() const                         { return _vm_result; }
1515   void set_vm_result  (oop x)                    { _vm_result   = x; }
1516 
1517   Metadata*    vm_result_2() const               { return _vm_result_2; }
1518   void set_vm_result_2  (Metadata* x)          { _vm_result_2   = x; }
1519 
1520   MemRegion deferred_card_mark() const           { return _deferred_card_mark; }
1521   void set_deferred_card_mark(MemRegion mr)      { _deferred_card_mark = mr;   }
1522 
1523 #if INCLUDE_JVMCI
1524   int  pending_deoptimization() const             { return _pending_deoptimization; }
1525   jlong pending_failed_speculation() const        { return _pending_failed_speculation; }
1526   bool has_pending_monitorenter() const           { return _pending_monitorenter; }
1527   void set_pending_monitorenter(bool b)           { _pending_monitorenter = b; }
1528   void set_pending_deoptimization(int reason)     { _pending_deoptimization = reason; }
1529   void set_pending_failed_speculation(jlong failed_speculation) { _pending_failed_speculation = failed_speculation; }
1530   void set_pending_transfer_to_interpreter(bool b) { _pending_transfer_to_interpreter = b; }
1531   void set_jvmci_alternate_call_target(address a) { assert(_jvmci._alternate_call_target == NULL, "must be"); _jvmci._alternate_call_target = a; }
1532   void set_jvmci_implicit_exception_pc(address a) { assert(_jvmci._implicit_exception_pc == NULL, "must be"); _jvmci._implicit_exception_pc = a; }
1533 
1534   virtual bool in_retryable_allocation() const    { return _in_retryable_allocation; }
1535   void set_in_retryable_allocation(bool b)        { _in_retryable_allocation = b; }
1536 #endif // INCLUDE_JVMCI
1537 
1538   // Exception handling for compiled methods
1539   oop      exception_oop() const                 { return _exception_oop; }
1540   address  exception_pc() const                  { return _exception_pc; }
1541   address  exception_handler_pc() const          { return _exception_handler_pc; }
1542   bool     is_method_handle_return() const       { return _is_method_handle_return == 1; }
1543 
1544   void set_exception_oop(oop o)                  { (void)const_cast<oop&>(_exception_oop = o); }
1545   void set_exception_pc(address a)               { _exception_pc = a; }
1546   void set_exception_handler_pc(address a)       { _exception_handler_pc = a; }
1547   void set_is_method_handle_return(bool value)   { _is_method_handle_return = value ? 1 : 0; }
1548 
1549   void clear_exception_oop_and_pc() {
1550     set_exception_oop(NULL);
1551     set_exception_pc(NULL);
1552   }
1553 
1554   // Stack overflow support
1555   //
1556   //  (small addresses)
1557   //
1558   //  --  <-- stack_end()                   ---
1559   //  |                                      |
1560   //  |  red pages                           |
1561   //  |                                      |
1562   //  --  <-- stack_red_zone_base()          |
1563   //  |                                      |
1564   //  |                                     guard
1565   //  |  yellow pages                       zone
1566   //  |                                      |
1567   //  |                                      |
1568   //  --  <-- stack_yellow_zone_base()       |
1569   //  |                                      |
1570   //  |                                      |
1571   //  |  reserved pages                      |
1572   //  |                                      |
1573   //  --  <-- stack_reserved_zone_base()    ---      ---
1574   //                                                 /|\  shadow     <--  stack_overflow_limit() (somewhere in here)
1575   //                                                  |   zone
1576   //                                                 \|/  size
1577   //  some untouched memory                          ---
1578   //
1579   //
1580   //  --
1581   //  |
1582   //  |  shadow zone
1583   //  |
1584   //  --
1585   //  x    frame n
1586   //  --
1587   //  x    frame n-1
1588   //  x
1589   //  --
1590   //  ...
1591   //
1592   //  --
1593   //  x    frame 0
1594   //  --  <-- stack_base()
1595   //
1596   //  (large addresses)
1597   //
1598 
1599  private:
1600   // These values are derived from flags StackRedPages, StackYellowPages,
1601   // StackReservedPages and StackShadowPages. The zone size is determined
1602   // ergonomically if page_size > 4K.
1603   static size_t _stack_red_zone_size;
1604   static size_t _stack_yellow_zone_size;
1605   static size_t _stack_reserved_zone_size;
1606   static size_t _stack_shadow_zone_size;
1607  public:
1608   inline size_t stack_available(address cur_sp);
1609 
1610   static size_t stack_red_zone_size() {
1611     assert(_stack_red_zone_size > 0, "Don't call this before the field is initialized.");
1612     return _stack_red_zone_size;
1613   }
1614   static void set_stack_red_zone_size(size_t s) {
1615     assert(is_aligned(s, os::vm_page_size()),
1616            "We can not protect if the red zone size is not page aligned.");
1617     assert(_stack_red_zone_size == 0, "This should be called only once.");
1618     _stack_red_zone_size = s;
1619   }
1620   address stack_red_zone_base() {
1621     return (address)(stack_end() + stack_red_zone_size());
1622   }
1623   bool in_stack_red_zone(address a) {
1624     return a <= stack_red_zone_base() && a >= stack_end();
1625   }
1626 
1627   static size_t stack_yellow_zone_size() {
1628     assert(_stack_yellow_zone_size > 0, "Don't call this before the field is initialized.");
1629     return _stack_yellow_zone_size;
1630   }
1631   static void set_stack_yellow_zone_size(size_t s) {
1632     assert(is_aligned(s, os::vm_page_size()),
1633            "We can not protect if the yellow zone size is not page aligned.");
1634     assert(_stack_yellow_zone_size == 0, "This should be called only once.");
1635     _stack_yellow_zone_size = s;
1636   }
1637 
1638   static size_t stack_reserved_zone_size() {
1639     // _stack_reserved_zone_size may be 0. This indicates the feature is off.
1640     return _stack_reserved_zone_size;
1641   }
1642   static void set_stack_reserved_zone_size(size_t s) {
1643     assert(is_aligned(s, os::vm_page_size()),
1644            "We can not protect if the reserved zone size is not page aligned.");
1645     assert(_stack_reserved_zone_size == 0, "This should be called only once.");
1646     _stack_reserved_zone_size = s;
1647   }
1648   address stack_reserved_zone_base() {
1649     return (address)(stack_end() +
1650                      (stack_red_zone_size() + stack_yellow_zone_size() + stack_reserved_zone_size()));
1651   }
1652   bool in_stack_reserved_zone(address a) {
1653     return (a <= stack_reserved_zone_base()) &&
1654            (a >= (address)((intptr_t)stack_reserved_zone_base() - stack_reserved_zone_size()));
1655   }
1656 
1657   static size_t stack_yellow_reserved_zone_size() {
1658     return _stack_yellow_zone_size + _stack_reserved_zone_size;
1659   }
1660   bool in_stack_yellow_reserved_zone(address a) {
1661     return (a <= stack_reserved_zone_base()) && (a >= stack_red_zone_base());
1662   }
1663 
1664   // Size of red + yellow + reserved zones.
1665   static size_t stack_guard_zone_size() {
1666     return stack_red_zone_size() + stack_yellow_reserved_zone_size();
1667   }
1668 
1669   static size_t stack_shadow_zone_size() {
1670     assert(_stack_shadow_zone_size > 0, "Don't call this before the field is initialized.");
1671     return _stack_shadow_zone_size;
1672   }
1673   static void set_stack_shadow_zone_size(size_t s) {
1674     // The shadow area is not allocated or protected, so
1675     // it needs not be page aligned.
1676     // But the stack bang currently assumes that it is a
1677     // multiple of page size. This guarantees that the bang
1678     // loop touches all pages in the shadow zone.
1679     // This can be guaranteed differently, as well.  E.g., if
1680     // the page size is a multiple of 4K, banging in 4K steps
1681     // suffices to touch all pages. (Some pages are banged
1682     // several times, though.)
1683     assert(is_aligned(s, os::vm_page_size()),
1684            "Stack bang assumes multiple of page size.");
1685     assert(_stack_shadow_zone_size == 0, "This should be called only once.");
1686     _stack_shadow_zone_size = s;
1687   }
1688 
1689   void create_stack_guard_pages();
1690   void remove_stack_guard_pages();
1691 
1692   void enable_stack_reserved_zone();
1693   void disable_stack_reserved_zone();
1694   void enable_stack_yellow_reserved_zone();
1695   void disable_stack_yellow_reserved_zone();
1696   void enable_stack_red_zone();
1697   void disable_stack_red_zone();
1698 
1699   inline bool stack_guard_zone_unused();
1700   inline bool stack_yellow_reserved_zone_disabled();
1701   inline bool stack_reserved_zone_disabled();
1702   inline bool stack_guards_enabled();
1703 
1704   address reserved_stack_activation() const { return _reserved_stack_activation; }
1705   void set_reserved_stack_activation(address addr) {
1706     assert(_reserved_stack_activation == stack_base()
1707             || _reserved_stack_activation == NULL
1708             || addr == stack_base(), "Must not be set twice");
1709     _reserved_stack_activation = addr;
1710   }
1711 
1712   // Attempt to reguard the stack after a stack overflow may have occurred.
1713   // Returns true if (a) guard pages are not needed on this thread, (b) the
1714   // pages are already guarded, or (c) the pages were successfully reguarded.
1715   // Returns false if there is not enough stack space to reguard the pages, in
1716   // which case the caller should unwind a frame and try again.  The argument
1717   // should be the caller's (approximate) sp.
1718   bool reguard_stack(address cur_sp);
1719   // Similar to above but see if current stackpoint is out of the guard area
1720   // and reguard if possible.
1721   bool reguard_stack(void);
1722 
1723   address stack_overflow_limit() { return _stack_overflow_limit; }
1724   void set_stack_overflow_limit() {
1725     _stack_overflow_limit =
1726       stack_end() + MAX2(JavaThread::stack_guard_zone_size(), JavaThread::stack_shadow_zone_size());
1727   }
1728 
1729   // Misc. accessors/mutators
1730   void set_do_not_unlock(void)                   { _do_not_unlock_if_synchronized = true; }
1731   void clr_do_not_unlock(void)                   { _do_not_unlock_if_synchronized = false; }
1732   bool do_not_unlock(void)                       { return _do_not_unlock_if_synchronized; }
1733 
1734   // For assembly stub generation
1735   static ByteSize threadObj_offset()             { return byte_offset_of(JavaThread, _threadObj); }
1736   static ByteSize jni_environment_offset()       { return byte_offset_of(JavaThread, _jni_environment); }
1737   static ByteSize pending_jni_exception_check_fn_offset() {
1738     return byte_offset_of(JavaThread, _pending_jni_exception_check_fn);
1739   }
1740   static ByteSize last_Java_sp_offset() {
1741     return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
1742   }
1743   static ByteSize last_Java_pc_offset() {
1744     return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
1745   }
1746   static ByteSize frame_anchor_offset() {
1747     return byte_offset_of(JavaThread, _anchor);
1748   }
1749   static ByteSize callee_target_offset()         { return byte_offset_of(JavaThread, _callee_target); }
1750   static ByteSize vm_result_offset()             { return byte_offset_of(JavaThread, _vm_result); }
1751   static ByteSize vm_result_2_offset()           { return byte_offset_of(JavaThread, _vm_result_2); }
1752   static ByteSize thread_state_offset()          { return byte_offset_of(JavaThread, _thread_state); }
1753   static ByteSize saved_exception_pc_offset()    { return byte_offset_of(JavaThread, _saved_exception_pc); }
1754   static ByteSize osthread_offset()              { return byte_offset_of(JavaThread, _osthread); }
1755 #if INCLUDE_JVMCI
1756   static ByteSize pending_deoptimization_offset() { return byte_offset_of(JavaThread, _pending_deoptimization); }
1757   static ByteSize pending_monitorenter_offset()  { return byte_offset_of(JavaThread, _pending_monitorenter); }
1758   static ByteSize pending_failed_speculation_offset() { return byte_offset_of(JavaThread, _pending_failed_speculation); }
1759   static ByteSize jvmci_alternate_call_target_offset() { return byte_offset_of(JavaThread, _jvmci._alternate_call_target); }
1760   static ByteSize jvmci_implicit_exception_pc_offset() { return byte_offset_of(JavaThread, _jvmci._implicit_exception_pc); }
1761   static ByteSize jvmci_counters_offset()        { return byte_offset_of(JavaThread, _jvmci_counters); }
1762 #endif // INCLUDE_JVMCI
1763   static ByteSize exception_oop_offset()         { return byte_offset_of(JavaThread, _exception_oop); }
1764   static ByteSize exception_pc_offset()          { return byte_offset_of(JavaThread, _exception_pc); }
1765   static ByteSize exception_handler_pc_offset()  { return byte_offset_of(JavaThread, _exception_handler_pc); }
1766   static ByteSize stack_overflow_limit_offset()  { return byte_offset_of(JavaThread, _stack_overflow_limit); }
1767   static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); }
1768   static ByteSize stack_guard_state_offset()     { return byte_offset_of(JavaThread, _stack_guard_state); }
1769   static ByteSize reserved_stack_activation_offset() { return byte_offset_of(JavaThread, _reserved_stack_activation); }
1770   static ByteSize suspend_flags_offset()         { return byte_offset_of(JavaThread, _suspend_flags); }
1771 
1772   static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
1773   static ByteSize should_post_on_exceptions_flag_offset() {
1774     return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
1775   }
1776   static ByteSize doing_unsafe_access_offset() { return byte_offset_of(JavaThread, _doing_unsafe_access); }
1777 
1778   // Returns the jni environment for this thread
1779   JNIEnv* jni_environment()                      { return &_jni_environment; }
1780 
1781   static JavaThread* thread_from_jni_environment(JNIEnv* env) {
1782     JavaThread *thread_from_jni_env = (JavaThread*)((intptr_t)env - in_bytes(jni_environment_offset()));
1783     // Only return NULL if thread is off the thread list; starting to
1784     // exit should not return NULL.
1785     if (thread_from_jni_env->is_terminated()) {
1786       thread_from_jni_env->block_if_vm_exited();
1787       return NULL;
1788     } else {
1789       return thread_from_jni_env;
1790     }
1791   }
1792 
1793   // JNI critical regions. These can nest.
1794   bool in_critical()    { return _jni_active_critical > 0; }
1795   bool in_last_critical()  { return _jni_active_critical == 1; }
1796   inline void enter_critical();
1797   void exit_critical() {
1798     assert(Thread::current() == this, "this must be current thread");
1799     _jni_active_critical--;
1800     assert(_jni_active_critical >= 0, "JNI critical nesting problem?");
1801   }
1802 
1803   // Checked JNI: is the programmer required to check for exceptions, if so specify
1804   // which function name. Returning to a Java frame should implicitly clear the
1805   // pending check, this is done for Native->Java transitions (i.e. user JNI code).
1806   // VM->Java transistions are not cleared, it is expected that JNI code enclosed
1807   // within ThreadToNativeFromVM makes proper exception checks (i.e. VM internal).
1808   bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != NULL; }
1809   void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = NULL; }
1810   const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; }
1811   void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; }
1812 
1813   // For deadlock detection
1814   int depth_first_number() { return _depth_first_number; }
1815   void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
1816 
1817  private:
1818   void set_monitor_chunks(MonitorChunk* monitor_chunks) { _monitor_chunks = monitor_chunks; }
1819 
1820  public:
1821   MonitorChunk* monitor_chunks() const           { return _monitor_chunks; }
1822   void add_monitor_chunk(MonitorChunk* chunk);
1823   void remove_monitor_chunk(MonitorChunk* chunk);
1824   bool in_deopt_handler() const                  { return _in_deopt_handler > 0; }
1825   void inc_in_deopt_handler()                    { _in_deopt_handler++; }
1826   void dec_in_deopt_handler() {
1827     assert(_in_deopt_handler > 0, "mismatched deopt nesting");
1828     if (_in_deopt_handler > 0) { // robustness
1829       _in_deopt_handler--;
1830     }
1831   }
1832 
1833  private:
1834   void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
1835 
1836  public:
1837 
1838   // Frame iteration; calls the function f for all frames on the stack
1839   void frames_do(void f(frame*, const RegisterMap*));
1840 
1841   // Memory operations
1842   void oops_do(OopClosure* f, CodeBlobClosure* cf);
1843 
1844   // Sweeper operations
1845   virtual void nmethods_do(CodeBlobClosure* cf);
1846 
1847   // RedefineClasses Support
1848   void metadata_do(MetadataClosure* f);
1849 
1850   // Debug method asserting thread states are correct during a handshake operation.
1851   DEBUG_ONLY(void verify_states_for_handshake();)
1852 
1853   // Misc. operations
1854   char* name() const { return (char*)get_thread_name(); }
1855   void print_on(outputStream* st, bool print_extended_info) const;
1856   void print_on(outputStream* st) const { print_on(st, false); }
1857   void print() const;
1858   void print_thread_state_on(outputStream*) const      PRODUCT_RETURN;
1859   void print_on_error(outputStream* st, char* buf, int buflen) const;
1860   void print_name_on_error(outputStream* st, char* buf, int buflen) const;
1861   void verify();
1862   const char* get_thread_name() const;
1863  protected:
1864   // factor out low-level mechanics for use in both normal and error cases
1865   virtual const char* get_thread_name_string(char* buf = NULL, int buflen = 0) const;
1866  public:
1867   // Accessing frames
1868   frame last_frame() {
1869     _anchor.make_walkable(this);
1870     return pd_last_frame();
1871   }
1872   javaVFrame* last_java_vframe(RegisterMap* reg_map);
1873 
1874   // Returns method at 'depth' java or native frames down the stack
1875   // Used for security checks
1876   Klass* security_get_caller_class(int depth);
1877 
1878   // Print stack trace in external format
1879   void print_stack_on(outputStream* st);
1880   void print_stack() { print_stack_on(tty); }
1881 
1882   // Print stack traces in various internal formats
1883   void trace_stack()                             PRODUCT_RETURN;
1884   void trace_stack_from(vframe* start_vf)        PRODUCT_RETURN;
1885   void trace_frames()                            PRODUCT_RETURN;
1886 
1887   // Print an annotated view of the stack frames
1888   void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN;
1889   void validate_frame_layout() {
1890     print_frame_layout(0, true);
1891   }
1892 
1893   // Function for testing deoptimization
1894   void deoptimize();
1895   void make_zombies();
1896 
1897   void deoptimize_marked_methods();
1898 
1899  public:
1900   // Returns the running thread as a JavaThread
1901   static inline JavaThread* current();
1902 
1903   // Returns the active Java thread.  Do not use this if you know you are calling
1904   // from a JavaThread, as it's slower than JavaThread::current.  If called from
1905   // the VMThread, it also returns the JavaThread that instigated the VMThread's
1906   // operation.  You may not want that either.
1907   static JavaThread* active();
1908 
1909   inline CompilerThread* as_CompilerThread();
1910 
1911  protected:
1912   virtual void pre_run();
1913   virtual void run();
1914   void thread_main_inner();
1915   virtual void post_run();
1916 
1917 
1918  private:
1919   GrowableArray<oop>* _array_for_gc;
1920  public:
1921 
1922   void register_array_for_gc(GrowableArray<oop>* array) { _array_for_gc = array; }
1923 
1924  public:
1925   // Thread local information maintained by JVMTI.
1926   void set_jvmti_thread_state(JvmtiThreadState *value)                           { _jvmti_thread_state = value; }
1927   // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1928   // getter is used to get this JavaThread's JvmtiThreadState if it has
1929   // one which means NULL can be returned. JvmtiThreadState::state_for()
1930   // is used to get the specified JavaThread's JvmtiThreadState if it has
1931   // one or it allocates a new JvmtiThreadState for the JavaThread and
1932   // returns it. JvmtiThreadState::state_for() will return NULL only if
1933   // the specified JavaThread is exiting.
1934   JvmtiThreadState *jvmti_thread_state() const                                   { return _jvmti_thread_state; }
1935   static ByteSize jvmti_thread_state_offset()                                    { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1936 
1937   // JVMTI PopFrame support
1938   // Setting and clearing popframe_condition
1939   // All of these enumerated values are bits. popframe_pending
1940   // indicates that a PopFrame() has been requested and not yet been
1941   // completed. popframe_processing indicates that that PopFrame() is in
1942   // the process of being completed. popframe_force_deopt_reexecution_bit
1943   // indicates that special handling is required when returning to a
1944   // deoptimized caller.
1945   enum PopCondition {
1946     popframe_inactive                      = 0x00,
1947     popframe_pending_bit                   = 0x01,
1948     popframe_processing_bit                = 0x02,
1949     popframe_force_deopt_reexecution_bit   = 0x04
1950   };
1951   PopCondition popframe_condition()                   { return (PopCondition) _popframe_condition; }
1952   void set_popframe_condition(PopCondition c)         { _popframe_condition = c; }
1953   void set_popframe_condition_bit(PopCondition c)     { _popframe_condition |= c; }
1954   void clear_popframe_condition()                     { _popframe_condition = popframe_inactive; }
1955   static ByteSize popframe_condition_offset()         { return byte_offset_of(JavaThread, _popframe_condition); }
1956   bool has_pending_popframe()                         { return (popframe_condition() & popframe_pending_bit) != 0; }
1957   bool popframe_forcing_deopt_reexecution()           { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
1958   void clear_popframe_forcing_deopt_reexecution()     { _popframe_condition &= ~popframe_force_deopt_reexecution_bit; }
1959 #ifdef CC_INTERP
1960   bool pop_frame_pending(void)                        { return ((_popframe_condition & popframe_pending_bit) != 0); }
1961   void clr_pop_frame_pending(void)                    { _popframe_condition = popframe_inactive; }
1962   bool pop_frame_in_process(void)                     { return ((_popframe_condition & popframe_processing_bit) != 0); }
1963   void set_pop_frame_in_process(void)                 { _popframe_condition |= popframe_processing_bit; }
1964   void clr_pop_frame_in_process(void)                 { _popframe_condition &= ~popframe_processing_bit; }
1965 #endif
1966 
1967   int frames_to_pop_failed_realloc() const            { return _frames_to_pop_failed_realloc; }
1968   void set_frames_to_pop_failed_realloc(int nb)       { _frames_to_pop_failed_realloc = nb; }
1969   void dec_frames_to_pop_failed_realloc()             { _frames_to_pop_failed_realloc--; }
1970 
1971  private:
1972   // Saved incoming arguments to popped frame.
1973   // Used only when popped interpreted frame returns to deoptimized frame.
1974   void*    _popframe_preserved_args;
1975   int      _popframe_preserved_args_size;
1976 
1977  public:
1978   void  popframe_preserve_args(ByteSize size_in_bytes, void* start);
1979   void* popframe_preserved_args();
1980   ByteSize popframe_preserved_args_size();
1981   WordSize popframe_preserved_args_size_in_words();
1982   void  popframe_free_preserved_args();
1983 
1984 
1985  private:
1986   JvmtiThreadState *_jvmti_thread_state;
1987 
1988   // Used by the interpreter in fullspeed mode for frame pop, method
1989   // entry, method exit and single stepping support. This field is
1990   // only set to non-zero by the VM_EnterInterpOnlyMode VM operation.
1991   // It can be set to zero asynchronously (i.e., without a VM operation
1992   // or a lock) so we have to be very careful.
1993   int               _interp_only_mode;
1994 
1995  public:
1996   // used by the interpreter for fullspeed debugging support (see above)
1997   static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
1998   bool is_interp_only_mode()                { return (_interp_only_mode != 0); }
1999   int get_interp_only_mode()                { return _interp_only_mode; }
2000   void increment_interp_only_mode()         { ++_interp_only_mode; }
2001   void decrement_interp_only_mode()         { --_interp_only_mode; }
2002 
2003   // support for cached flag that indicates whether exceptions need to be posted for this thread
2004   // if this is false, we can avoid deoptimizing when events are thrown
2005   // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
2006  private:
2007   int    _should_post_on_exceptions_flag;
2008 
2009  public:
2010   int   should_post_on_exceptions_flag()  { return _should_post_on_exceptions_flag; }
2011   void  set_should_post_on_exceptions_flag(int val)  { _should_post_on_exceptions_flag = val; }
2012 
2013  private:
2014   ThreadStatistics *_thread_stat;
2015 
2016  public:
2017   ThreadStatistics* get_thread_stat() const    { return _thread_stat; }
2018 
2019   // Return a blocker object for which this thread is blocked parking.
2020   oop current_park_blocker();
2021 
2022  private:
2023   static size_t _stack_size_at_create;
2024 
2025  public:
2026   static inline size_t stack_size_at_create(void) {
2027     return _stack_size_at_create;
2028   }
2029   static inline void set_stack_size_at_create(size_t value) {
2030     _stack_size_at_create = value;
2031   }
2032 
2033   // Machine dependent stuff
2034 #include OS_CPU_HEADER(thread)
2035 
2036   // JSR166 per-thread parker
2037  private:
2038   Parker*    _parker;
2039  public:
2040   Parker*     parker() { return _parker; }
2041 
2042   // Biased locking support
2043  private:
2044   GrowableArray<MonitorInfo*>* _cached_monitor_info;
2045  public:
2046   GrowableArray<MonitorInfo*>* cached_monitor_info() { return _cached_monitor_info; }
2047   void set_cached_monitor_info(GrowableArray<MonitorInfo*>* info) { _cached_monitor_info = info; }
2048 
2049   // clearing/querying jni attach status
2050   bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; }
2051   bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
2052   inline void set_done_attaching_via_jni();
2053 
2054   // Stack dump assistance:
2055   // Track the class we want to initialize but for which we have to wait
2056   // on its init_lock() because it is already being initialized.
2057   void set_class_to_be_initialized(InstanceKlass* k);
2058   InstanceKlass* class_to_be_initialized() const;
2059 
2060 private:
2061   InstanceKlass* _class_to_be_initialized;
2062 
2063   // java.lang.Thread.sleep support
2064   ParkEvent * _SleepEvent;
2065 public:
2066   bool sleep(jlong millis);
2067 
2068   // java.lang.Thread interruption support
2069   void interrupt();
2070   bool is_interrupted(bool clear_interrupted);
2071 
2072 };
2073 
2074 // Inline implementation of JavaThread::current
2075 inline JavaThread* JavaThread::current() {
2076   Thread* thread = Thread::current();
2077   assert(thread->is_Java_thread(), "just checking");
2078   return (JavaThread*)thread;
2079 }
2080 
2081 inline CompilerThread* JavaThread::as_CompilerThread() {
2082   assert(is_Compiler_thread(), "just checking");
2083   return (CompilerThread*)this;
2084 }
2085 
2086 // Dedicated thread to sweep the code cache
2087 class CodeCacheSweeperThread : public JavaThread {
2088   CompiledMethod*       _scanned_compiled_method; // nmethod being scanned by the sweeper
2089  public:
2090   CodeCacheSweeperThread();
2091   // Track the nmethod currently being scanned by the sweeper
2092   void set_scanned_compiled_method(CompiledMethod* cm) {
2093     assert(_scanned_compiled_method == NULL || cm == NULL, "should reset to NULL before writing a new value");
2094     _scanned_compiled_method = cm;
2095   }
2096 
2097   // Hide sweeper thread from external view.
2098   bool is_hidden_from_external_view() const { return true; }
2099 
2100   bool is_Code_cache_sweeper_thread() const { return true; }
2101 
2102   // Prevent GC from unloading _scanned_compiled_method
2103   void oops_do(OopClosure* f, CodeBlobClosure* cf);
2104   void nmethods_do(CodeBlobClosure* cf);
2105 };
2106 
2107 // A thread used for Compilation.
2108 class CompilerThread : public JavaThread {
2109   friend class VMStructs;
2110  private:
2111   CompilerCounters* _counters;
2112 
2113   ciEnv*                _env;
2114   CompileLog*           _log;
2115   CompileTask* volatile _task;  // print_threads_compiling can read this concurrently.
2116   CompileQueue*         _queue;
2117   BufferBlob*           _buffer_blob;
2118 
2119   AbstractCompiler*     _compiler;
2120   TimeStamp             _idle_time;
2121 
2122  public:
2123 
2124   static CompilerThread* current();
2125 
2126   CompilerThread(CompileQueue* queue, CompilerCounters* counters);
2127   ~CompilerThread();
2128 
2129   bool is_Compiler_thread() const                { return true; }
2130 
2131   virtual bool can_call_java() const;
2132 
2133   // Hide native compiler threads from external view.
2134   bool is_hidden_from_external_view() const      { return !can_call_java(); }
2135 
2136   void set_compiler(AbstractCompiler* c)         { _compiler = c; }
2137   AbstractCompiler* compiler() const             { return _compiler; }
2138 
2139   CompileQueue* queue()        const             { return _queue; }
2140   CompilerCounters* counters() const             { return _counters; }
2141 
2142   // Get/set the thread's compilation environment.
2143   ciEnv*        env()                            { return _env; }
2144   void          set_env(ciEnv* env)              { _env = env; }
2145 
2146   BufferBlob*   get_buffer_blob() const          { return _buffer_blob; }
2147   void          set_buffer_blob(BufferBlob* b)   { _buffer_blob = b; }
2148 
2149   // Get/set the thread's logging information
2150   CompileLog*   log()                            { return _log; }
2151   void          init_log(CompileLog* log) {
2152     // Set once, for good.
2153     assert(_log == NULL, "set only once");
2154     _log = log;
2155   }
2156 
2157   void start_idle_timer()                        { _idle_time.update(); }
2158   jlong idle_time_millis() {
2159     return TimeHelper::counter_to_millis(_idle_time.ticks_since_update());
2160   }
2161 
2162 #ifndef PRODUCT
2163  private:
2164   IdealGraphPrinter *_ideal_graph_printer;
2165  public:
2166   IdealGraphPrinter *ideal_graph_printer()           { return _ideal_graph_printer; }
2167   void set_ideal_graph_printer(IdealGraphPrinter *n) { _ideal_graph_printer = n; }
2168 #endif
2169 
2170   // Get/set the thread's current task
2171   CompileTask* task()                      { return _task; }
2172   void         set_task(CompileTask* task) { _task = task; }
2173 };
2174 
2175 inline CompilerThread* CompilerThread::current() {
2176   return JavaThread::current()->as_CompilerThread();
2177 }
2178 
2179 // The active thread queue. It also keeps track of the current used
2180 // thread priorities.
2181 class Threads: AllStatic {
2182   friend class VMStructs;
2183  private:
2184   static int         _number_of_threads;
2185   static int         _number_of_non_daemon_threads;
2186   static int         _return_code;
2187   static uintx       _thread_claim_token;
2188 #ifdef ASSERT
2189   static bool        _vm_complete;
2190 #endif
2191 
2192   static void initialize_java_lang_classes(JavaThread* main_thread, TRAPS);
2193   static void initialize_jsr292_core_classes(TRAPS);
2194 
2195  public:
2196   // Thread management
2197   // force_daemon is a concession to JNI, where we may need to add a
2198   // thread to the thread list before allocating its thread object
2199   static void add(JavaThread* p, bool force_daemon = false);
2200   static void remove(JavaThread* p, bool is_daemon);
2201   static void non_java_threads_do(ThreadClosure* tc);
2202   static void java_threads_do(ThreadClosure* tc);
2203   static void java_threads_and_vm_thread_do(ThreadClosure* tc);
2204   static void threads_do(ThreadClosure* tc);
2205   static void possibly_parallel_threads_do(bool is_par, ThreadClosure* tc);
2206 
2207   // Initializes the vm and creates the vm thread
2208   static jint create_vm(JavaVMInitArgs* args, bool* canTryAgain);
2209   static void convert_vm_init_libraries_to_agents();
2210   static void create_vm_init_libraries();
2211   static void create_vm_init_agents();
2212   static void shutdown_vm_agents();
2213   static bool destroy_vm();
2214   // Supported VM versions via JNI
2215   // Includes JNI_VERSION_1_1
2216   static jboolean is_supported_jni_version_including_1_1(jint version);
2217   // Does not include JNI_VERSION_1_1
2218   static jboolean is_supported_jni_version(jint version);
2219 
2220   // The "thread claim token" provides a way for threads to be claimed
2221   // by parallel worker tasks.
2222   //
2223   // Each thread contains a "token" field. A task will claim the
2224   // thread only if its token is different from the global token,
2225   // which is updated by calling change_thread_claim_token().  When
2226   // a thread is claimed, it's token is set to the global token value
2227   // so other threads in the same iteration pass won't claim it.
2228   //
2229   // For this to work change_thread_claim_token() needs to be called
2230   // exactly once in sequential code before starting parallel tasks
2231   // that should claim threads.
2232   //
2233   // New threads get their token set to 0 and change_thread_claim_token()
2234   // never sets the global token to 0.
2235   static uintx thread_claim_token() { return _thread_claim_token; }
2236   static void change_thread_claim_token();
2237   static void assert_all_threads_claimed() NOT_DEBUG_RETURN;
2238 
2239   // Apply "f->do_oop" to all root oops in all threads.
2240   // This version may only be called by sequential code.
2241   static void oops_do(OopClosure* f, CodeBlobClosure* cf);
2242   // This version may be called by sequential or parallel code.
2243   static void possibly_parallel_oops_do(bool is_par, OopClosure* f, CodeBlobClosure* cf);
2244 
2245   // Sweeper
2246   static void nmethods_do(CodeBlobClosure* cf);
2247 
2248   // RedefineClasses support
2249   static void metadata_do(MetadataClosure* f);
2250   static void metadata_handles_do(void f(Metadata*));
2251 
2252 #ifdef ASSERT
2253   static bool is_vm_complete() { return _vm_complete; }
2254 #endif // ASSERT
2255 
2256   // Verification
2257   static void verify();
2258   static void print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks, bool print_extended_info);
2259   static void print(bool print_stacks, bool internal_format) {
2260     // this function is only used by debug.cpp
2261     print_on(tty, print_stacks, internal_format, false /* no concurrent lock printed */, false /* simple format */);
2262   }
2263   static void print_on_error(outputStream* st, Thread* current, char* buf, int buflen);
2264   static void print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
2265                              int buflen, bool* found_current);
2266   static void print_threads_compiling(outputStream* st, char* buf, int buflen, bool short_form = false);
2267 
2268   // Get Java threads that are waiting to enter a monitor.
2269   static GrowableArray<JavaThread*>* get_pending_threads(ThreadsList * t_list,
2270                                                          int count, address monitor);
2271 
2272   // Get owning Java thread from the monitor's owner field.
2273   static JavaThread *owning_thread_from_monitor_owner(ThreadsList * t_list,
2274                                                       address owner);
2275 
2276   // Number of threads on the active threads list
2277   static int number_of_threads()                 { return _number_of_threads; }
2278   // Number of non-daemon threads on the active threads list
2279   static int number_of_non_daemon_threads()      { return _number_of_non_daemon_threads; }
2280 
2281   // Deoptimizes all frames tied to marked nmethods
2282   static void deoptimized_wrt_marked_nmethods();
2283 
2284   struct Test;                  // For private gtest access.
2285 };
2286 
2287 
2288 // Thread iterator
2289 class ThreadClosure: public StackObj {
2290  public:
2291   virtual void do_thread(Thread* thread) = 0;
2292 };
2293 
2294 class SignalHandlerMark: public StackObj {
2295  private:
2296   Thread* _thread;
2297  public:
2298   SignalHandlerMark(Thread* t) {
2299     _thread = t;
2300     if (_thread) _thread->enter_signal_handler();
2301   }
2302   ~SignalHandlerMark() {
2303     if (_thread) _thread->leave_signal_handler();
2304     _thread = NULL;
2305   }
2306 };
2307 
2308 
2309 #endif // SHARE_RUNTIME_THREAD_HPP
--- EOF ---