1 /* 2 * Copyright 1997-2009 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, 20 * CA 95054 USA or visit www.sun.com if you need additional information or 21 * have any questions. 22 * 23 */ 24 25 class ThreadSafepointState; 26 class ThreadProfiler; 27 28 class JvmtiThreadState; 29 class JvmtiGetLoadedClassesClosure; 30 class ThreadStatistics; 31 class ConcurrentLocksDump; 32 class ParkEvent ; 33 34 class ciEnv; 35 class CompileThread; 36 class CompileLog; 37 class CompileTask; 38 class CompileQueue; 39 class CompilerCounters; 40 class vframeArray; 41 42 class DeoptResourceMark; 43 class jvmtiDeferredLocalVariableSet; 44 45 class GCTaskQueue; 46 class ThreadClosure; 47 class IdealGraphPrinter; 48 49 // Class hierarchy 50 // - Thread 51 // - VMThread 52 // - JavaThread 53 // - WatcherThread 54 55 class Thread: public ThreadShadow { 56 friend class VMStructs; 57 private: 58 // Exception handling 59 // (Note: _pending_exception and friends are in ThreadShadow) 60 //oop _pending_exception; // pending exception for current thread 61 // const char* _exception_file; // file information for exception (debugging only) 62 // int _exception_line; // line information for exception (debugging only) 63 64 // Support for forcing alignment of thread objects for biased locking 65 void* _real_malloc_address; 66 public: 67 void* operator new(size_t size); 68 void operator delete(void* p); 69 private: 70 71 // *************************************************************** 72 // Suspend and resume support 73 // *************************************************************** 74 // 75 // VM suspend/resume no longer exists - it was once used for various 76 // things including safepoints but was deprecated and finally removed 77 // in Java 7. Because VM suspension was considered "internal" Java-level 78 // suspension was considered "external", and this legacy naming scheme 79 // remains. 80 // 81 // External suspend/resume requests come from JVM_SuspendThread, 82 // JVM_ResumeThread, JVMTI SuspendThread, and finally JVMTI 83 // ResumeThread. External 84 // suspend requests cause _external_suspend to be set and external 85 // resume requests cause _external_suspend to be cleared. 86 // External suspend requests do not nest on top of other external 87 // suspend requests. The higher level APIs reject suspend requests 88 // for already suspended threads. 89 // 90 // The external_suspend 91 // flag is checked by has_special_runtime_exit_condition() and java thread 92 // will self-suspend when handle_special_runtime_exit_condition() is 93 // called. Most uses of the _thread_blocked state in JavaThreads are 94 // considered the same as being externally suspended; if the blocking 95 // condition lifts, the JavaThread will self-suspend. Other places 96 // where VM checks for external_suspend include: 97 // + mutex granting (do not enter monitors when thread is suspended) 98 // + state transitions from _thread_in_native 99 // 100 // In general, java_suspend() does not wait for an external suspend 101 // request to complete. When it returns, the only guarantee is that 102 // the _external_suspend field is true. 103 // 104 // wait_for_ext_suspend_completion() is used to wait for an external 105 // suspend request to complete. External suspend requests are usually 106 // followed by some other interface call that requires the thread to 107 // be quiescent, e.g., GetCallTrace(). By moving the "wait time" into 108 // the interface that requires quiescence, we give the JavaThread a 109 // chance to self-suspend before we need it to be quiescent. This 110 // improves overall suspend/query performance. 111 // 112 // _suspend_flags controls the behavior of java_ suspend/resume. 113 // It must be set under the protection of SR_lock. Read from the flag is 114 // OK without SR_lock as long as the value is only used as a hint. 115 // (e.g., check _external_suspend first without lock and then recheck 116 // inside SR_lock and finish the suspension) 117 // 118 // _suspend_flags is also overloaded for other "special conditions" so 119 // that a single check indicates whether any special action is needed 120 // eg. for async exceptions. 121 // ------------------------------------------------------------------- 122 // Notes: 123 // 1. The suspend/resume logic no longer uses ThreadState in OSThread 124 // but we still update its value to keep other part of the system (mainly 125 // JVMTI) happy. ThreadState is legacy code (see notes in 126 // osThread.hpp). 127 // 128 // 2. It would be more natural if set_external_suspend() is private and 129 // part of java_suspend(), but that probably would affect the suspend/query 130 // performance. Need more investigation on this. 131 // 132 133 // suspend/resume lock: used for self-suspend 134 Monitor* _SR_lock; 135 136 protected: 137 enum SuspendFlags { 138 // NOTE: avoid using the sign-bit as cc generates different test code 139 // when the sign-bit is used, and sometimes incorrectly - see CR 6398077 140 141 _external_suspend = 0x20000000U, // thread is asked to self suspend 142 _ext_suspended = 0x40000000U, // thread has self-suspended 143 _deopt_suspend = 0x10000000U, // thread needs to self suspend for deopt 144 145 _has_async_exception = 0x00000001U // there is a pending async exception 146 }; 147 148 // various suspension related flags - atomically updated 149 // overloaded for async exception checking in check_special_condition_for_native_trans. 150 volatile uint32_t _suspend_flags; 151 152 private: 153 int _num_nested_signal; 154 155 public: 156 void enter_signal_handler() { _num_nested_signal++; } 157 void leave_signal_handler() { _num_nested_signal--; } 158 bool is_inside_signal_handler() const { return _num_nested_signal > 0; } 159 160 private: 161 // Debug tracing 162 static void trace(const char* msg, const Thread* const thread) PRODUCT_RETURN; 163 164 // Active_handles points to a block of handles 165 JNIHandleBlock* _active_handles; 166 167 // One-element thread local free list 168 JNIHandleBlock* _free_handle_block; 169 170 // Point to the last handle mark 171 HandleMark* _last_handle_mark; 172 173 // The parity of the last strong_roots iteration in which this thread was 174 // claimed as a task. 175 jint _oops_do_parity; 176 177 public: 178 void set_last_handle_mark(HandleMark* mark) { _last_handle_mark = mark; } 179 HandleMark* last_handle_mark() const { return _last_handle_mark; } 180 private: 181 182 // debug support for checking if code does allow safepoints or not 183 // GC points in the VM can happen because of allocation, invoking a VM operation, or blocking on 184 // mutex, or blocking on an object synchronizer (Java locking). 185 // If !allow_safepoint(), then an assertion failure will happen in any of the above cases 186 // If !allow_allocation(), then an assertion failure will happen during allocation 187 // (Hence, !allow_safepoint() => !allow_allocation()). 188 // 189 // The two classes No_Safepoint_Verifier and No_Allocation_Verifier are used to set these counters. 190 // 191 NOT_PRODUCT(int _allow_safepoint_count;) // If 0, thread allow a safepoint to happen 192 debug_only (int _allow_allocation_count;) // If 0, the thread is allowed to allocate oops. 193 194 // Used by SkipGCALot class. 195 NOT_PRODUCT(bool _skip_gcalot;) // Should we elide gc-a-lot? 196 197 // Record when GC is locked out via the GC_locker mechanism 198 CHECK_UNHANDLED_OOPS_ONLY(int _gc_locked_out_count;) 199 200 friend class No_Alloc_Verifier; 201 friend class No_Safepoint_Verifier; 202 friend class Pause_No_Safepoint_Verifier; 203 friend class ThreadLocalStorage; 204 friend class GC_locker; 205 206 ThreadLocalAllocBuffer _tlab; // Thread-local eden 207 208 int _vm_operation_started_count; // VM_Operation support 209 int _vm_operation_completed_count; // VM_Operation support 210 211 ObjectMonitor* _current_pending_monitor; // ObjectMonitor this thread 212 // is waiting to lock 213 bool _current_pending_monitor_is_from_java; // locking is from Java code 214 215 // ObjectMonitor on which this thread called Object.wait() 216 ObjectMonitor* _current_waiting_monitor; 217 218 // Private thread-local objectmonitor list - a simple cache organized as a SLL. 219 public: 220 ObjectMonitor * omFreeList ; 221 int omFreeCount ; // length of omFreeList 222 int omFreeProvision ; // reload chunk size 223 224 public: 225 enum { 226 is_definitely_current_thread = true 227 }; 228 229 // Constructor 230 Thread(); 231 virtual ~Thread(); 232 233 // initializtion 234 void initialize_thread_local_storage(); 235 236 // thread entry point 237 virtual void run(); 238 239 // Testers 240 virtual bool is_VM_thread() const { return false; } 241 virtual bool is_Java_thread() const { return false; } 242 // Remove this ifdef when C1 is ported to the compiler interface. 243 virtual bool is_Compiler_thread() const { return false; } 244 virtual bool is_hidden_from_external_view() const { return false; } 245 virtual bool is_jvmti_agent_thread() const { return false; } 246 // True iff the thread can perform GC operations at a safepoint. 247 // Generally will be true only of VM thread and parallel GC WorkGang 248 // threads. 249 virtual bool is_GC_task_thread() const { return false; } 250 virtual bool is_Watcher_thread() const { return false; } 251 virtual bool is_ConcurrentGC_thread() const { return false; } 252 253 virtual char* name() const { return (char*)"Unknown thread"; } 254 255 // Returns the current thread 256 static inline Thread* current(); 257 258 // Common thread operations 259 static void set_priority(Thread* thread, ThreadPriority priority); 260 static ThreadPriority get_priority(const Thread* const thread); 261 static void start(Thread* thread); 262 static void interrupt(Thread* thr); 263 static bool is_interrupted(Thread* thr, bool clear_interrupted); 264 265 Monitor* SR_lock() const { return _SR_lock; } 266 267 bool has_async_exception() const { return (_suspend_flags & _has_async_exception) != 0; } 268 269 void set_suspend_flag(SuspendFlags f) { 270 assert(sizeof(jint) == sizeof(_suspend_flags), "size mismatch"); 271 uint32_t flags; 272 do { 273 flags = _suspend_flags; 274 } 275 while (Atomic::cmpxchg((jint)(flags | f), 276 (volatile jint*)&_suspend_flags, 277 (jint)flags) != (jint)flags); 278 } 279 void clear_suspend_flag(SuspendFlags f) { 280 assert(sizeof(jint) == sizeof(_suspend_flags), "size mismatch"); 281 uint32_t flags; 282 do { 283 flags = _suspend_flags; 284 } 285 while (Atomic::cmpxchg((jint)(flags & ~f), 286 (volatile jint*)&_suspend_flags, 287 (jint)flags) != (jint)flags); 288 } 289 290 void set_has_async_exception() { 291 set_suspend_flag(_has_async_exception); 292 } 293 void clear_has_async_exception() { 294 clear_suspend_flag(_has_async_exception); 295 } 296 297 // Support for Unhandled Oop detection 298 #ifdef CHECK_UNHANDLED_OOPS 299 private: 300 UnhandledOops *_unhandled_oops; 301 public: 302 UnhandledOops* unhandled_oops() { return _unhandled_oops; } 303 // Mark oop safe for gc. It may be stack allocated but won't move. 304 void allow_unhandled_oop(oop *op) { 305 if (CheckUnhandledOops) unhandled_oops()->allow_unhandled_oop(op); 306 } 307 // Clear oops at safepoint so crashes point to unhandled oop violator 308 void clear_unhandled_oops() { 309 if (CheckUnhandledOops) unhandled_oops()->clear_unhandled_oops(); 310 } 311 bool is_gc_locked_out() { return _gc_locked_out_count > 0; } 312 #endif // CHECK_UNHANDLED_OOPS 313 314 #ifndef PRODUCT 315 bool skip_gcalot() { return _skip_gcalot; } 316 void set_skip_gcalot(bool v) { _skip_gcalot = v; } 317 #endif 318 319 public: 320 // Installs a pending exception to be inserted later 321 static void send_async_exception(oop thread_oop, oop java_throwable); 322 323 // Resource area 324 ResourceArea* resource_area() const { return _resource_area; } 325 void set_resource_area(ResourceArea* area) { _resource_area = area; } 326 327 OSThread* osthread() const { return _osthread; } 328 void set_osthread(OSThread* thread) { _osthread = thread; } 329 330 // JNI handle support 331 JNIHandleBlock* active_handles() const { return _active_handles; } 332 void set_active_handles(JNIHandleBlock* block) { _active_handles = block; } 333 JNIHandleBlock* free_handle_block() const { return _free_handle_block; } 334 void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; } 335 336 // Internal handle support 337 HandleArea* handle_area() const { return _handle_area; } 338 void set_handle_area(HandleArea* area) { _handle_area = area; } 339 340 // Thread-Local Allocation Buffer (TLAB) support 341 ThreadLocalAllocBuffer& tlab() { return _tlab; } 342 void initialize_tlab() { 343 if (UseTLAB) { 344 tlab().initialize(); 345 } 346 } 347 348 // VM operation support 349 int vm_operation_ticket() { return ++_vm_operation_started_count; } 350 int vm_operation_completed_count() { return _vm_operation_completed_count; } 351 void increment_vm_operation_completed_count() { _vm_operation_completed_count++; } 352 353 // For tracking the heavyweight monitor the thread is pending on. 354 ObjectMonitor* current_pending_monitor() { 355 return _current_pending_monitor; 356 } 357 void set_current_pending_monitor(ObjectMonitor* monitor) { 358 _current_pending_monitor = monitor; 359 } 360 void set_current_pending_monitor_is_from_java(bool from_java) { 361 _current_pending_monitor_is_from_java = from_java; 362 } 363 bool current_pending_monitor_is_from_java() { 364 return _current_pending_monitor_is_from_java; 365 } 366 367 // For tracking the ObjectMonitor on which this thread called Object.wait() 368 ObjectMonitor* current_waiting_monitor() { 369 return _current_waiting_monitor; 370 } 371 void set_current_waiting_monitor(ObjectMonitor* monitor) { 372 _current_waiting_monitor = monitor; 373 } 374 375 // GC support 376 // Apply "f->do_oop" to all root oops in "this". 377 // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames 378 void oops_do(OopClosure* f, CodeBlobClosure* cf); 379 380 // Handles the parallel case for the method below. 381 private: 382 bool claim_oops_do_par_case(int collection_parity); 383 public: 384 // Requires that "collection_parity" is that of the current strong roots 385 // iteration. If "is_par" is false, sets the parity of "this" to 386 // "collection_parity", and returns "true". If "is_par" is true, 387 // uses an atomic instruction to set the current threads parity to 388 // "collection_parity", if it is not already. Returns "true" iff the 389 // calling thread does the update, this indicates that the calling thread 390 // has claimed the thread's stack as a root groop in the current 391 // collection. 392 bool claim_oops_do(bool is_par, int collection_parity) { 393 if (!is_par) { 394 _oops_do_parity = collection_parity; 395 return true; 396 } else { 397 return claim_oops_do_par_case(collection_parity); 398 } 399 } 400 401 // Sweeper support 402 void nmethods_do(CodeBlobClosure* cf); 403 404 // Tells if adr belong to this thread. This is used 405 // for checking if a lock is owned by the running thread. 406 407 // Used by fast lock support 408 virtual bool is_lock_owned(address adr) const; 409 410 // Check if address is in the stack of the thread (not just for locks). 411 // Warning: the method can only be used on the running thread 412 bool is_in_stack(address adr) const; 413 414 // Sets this thread as starting thread. Returns failure if thread 415 // creation fails due to lack of memory, too many threads etc. 416 bool set_as_starting_thread(); 417 418 protected: 419 // OS data associated with the thread 420 OSThread* _osthread; // Platform-specific thread information 421 422 // Thread local resource area for temporary allocation within the VM 423 ResourceArea* _resource_area; 424 425 // Thread local handle area for allocation of handles within the VM 426 HandleArea* _handle_area; 427 428 // Support for stack overflow handling, get_thread, etc. 429 address _stack_base; 430 size_t _stack_size; 431 uintptr_t _self_raw_id; // used by get_thread (mutable) 432 int _lgrp_id; 433 434 public: 435 // Stack overflow support 436 address stack_base() const { assert(_stack_base != NULL,"Sanity check"); return _stack_base; } 437 438 void set_stack_base(address base) { _stack_base = base; } 439 size_t stack_size() const { return _stack_size; } 440 void set_stack_size(size_t size) { _stack_size = size; } 441 void record_stack_base_and_size(); 442 443 int lgrp_id() const { return _lgrp_id; } 444 void set_lgrp_id(int value) { _lgrp_id = value; } 445 446 // Printing 447 void print_on(outputStream* st) const; 448 void print() const { print_on(tty); } 449 virtual void print_on_error(outputStream* st, char* buf, int buflen) const; 450 451 // Debug-only code 452 453 #ifdef ASSERT 454 private: 455 // Deadlock detection support for Mutex locks. List of locks own by thread. 456 Monitor *_owned_locks; 457 // Mutex::set_owner_implementation is the only place where _owned_locks is modified, 458 // thus the friendship 459 friend class Mutex; 460 friend class Monitor; 461 462 public: 463 void print_owned_locks_on(outputStream* st) const; 464 void print_owned_locks() const { print_owned_locks_on(tty); } 465 Monitor * owned_locks() const { return _owned_locks; } 466 bool owns_locks() const { return owned_locks() != NULL; } 467 bool owns_locks_but_compiled_lock() const; 468 469 // Deadlock detection 470 bool allow_allocation() { return _allow_allocation_count == 0; } 471 #endif 472 473 void check_for_valid_safepoint_state(bool potential_vm_operation) PRODUCT_RETURN; 474 475 private: 476 volatile int _jvmti_env_iteration_count; 477 478 public: 479 void entering_jvmti_env_iteration() { ++_jvmti_env_iteration_count; } 480 void leaving_jvmti_env_iteration() { --_jvmti_env_iteration_count; } 481 bool is_inside_jvmti_env_iteration() { return _jvmti_env_iteration_count > 0; } 482 483 // Code generation 484 static ByteSize exception_file_offset() { return byte_offset_of(Thread, _exception_file ); } 485 static ByteSize exception_line_offset() { return byte_offset_of(Thread, _exception_line ); } 486 static ByteSize active_handles_offset() { return byte_offset_of(Thread, _active_handles ); } 487 488 static ByteSize stack_base_offset() { return byte_offset_of(Thread, _stack_base ); } 489 static ByteSize stack_size_offset() { return byte_offset_of(Thread, _stack_size ); } 490 static ByteSize omFreeList_offset() { return byte_offset_of(Thread, omFreeList); } 491 492 #define TLAB_FIELD_OFFSET(name) \ 493 static ByteSize tlab_##name##_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::name##_offset(); } 494 495 TLAB_FIELD_OFFSET(start) 496 TLAB_FIELD_OFFSET(end) 497 TLAB_FIELD_OFFSET(top) 498 TLAB_FIELD_OFFSET(pf_top) 499 TLAB_FIELD_OFFSET(size) // desired_size 500 TLAB_FIELD_OFFSET(refill_waste_limit) 501 TLAB_FIELD_OFFSET(number_of_refills) 502 TLAB_FIELD_OFFSET(fast_refill_waste) 503 TLAB_FIELD_OFFSET(slow_allocations) 504 505 #undef TLAB_FIELD_OFFSET 506 507 public: 508 volatile intptr_t _Stalled ; 509 volatile int _TypeTag ; 510 ParkEvent * _ParkEvent ; // for synchronized() 511 ParkEvent * _SleepEvent ; // for Thread.sleep 512 ParkEvent * _MutexEvent ; // for native internal Mutex/Monitor 513 ParkEvent * _MuxEvent ; // for low-level muxAcquire-muxRelease 514 int NativeSyncRecursion ; // diagnostic 515 516 volatile int _OnTrap ; // Resume-at IP delta 517 jint _hashStateW ; // Marsaglia Shift-XOR thread-local RNG 518 jint _hashStateX ; // thread-specific hashCode generator state 519 jint _hashStateY ; 520 jint _hashStateZ ; 521 void * _schedctl ; 522 523 intptr_t _ScratchA, _ScratchB ; // Scratch locations for fast-path sync code 524 static ByteSize ScratchA_offset() { return byte_offset_of(Thread, _ScratchA ); } 525 static ByteSize ScratchB_offset() { return byte_offset_of(Thread, _ScratchB ); } 526 527 volatile jint rng [4] ; // RNG for spin loop 528 529 // Low-level leaf-lock primitives used to implement synchronization 530 // and native monitor-mutex infrastructure. 531 // Not for general synchronization use. 532 static void SpinAcquire (volatile int * Lock, const char * Name) ; 533 static void SpinRelease (volatile int * Lock) ; 534 static void muxAcquire (volatile intptr_t * Lock, const char * Name) ; 535 static void muxAcquireW (volatile intptr_t * Lock, ParkEvent * ev) ; 536 static void muxRelease (volatile intptr_t * Lock) ; 537 538 }; 539 540 // Inline implementation of Thread::current() 541 // Thread::current is "hot" it's called > 128K times in the 1st 500 msecs of 542 // startup. 543 // ThreadLocalStorage::thread is warm -- it's called > 16K times in the same 544 // period. This is inlined in thread_<os_family>.inline.hpp. 545 546 inline Thread* Thread::current() { 547 #ifdef ASSERT 548 // This function is very high traffic. Define PARANOID to enable expensive 549 // asserts. 550 #ifdef PARANOID 551 // Signal handler should call ThreadLocalStorage::get_thread_slow() 552 Thread* t = ThreadLocalStorage::get_thread_slow(); 553 assert(t != NULL && !t->is_inside_signal_handler(), 554 "Don't use Thread::current() inside signal handler"); 555 #endif 556 #endif 557 Thread* thread = ThreadLocalStorage::thread(); 558 assert(thread != NULL, "just checking"); 559 return thread; 560 } 561 562 // Name support for threads. non-JavaThread subclasses with multiple 563 // uniquely named instances should derive from this. 564 class NamedThread: public Thread { 565 friend class VMStructs; 566 enum { 567 max_name_len = 64 568 }; 569 private: 570 char* _name; 571 public: 572 NamedThread(); 573 ~NamedThread(); 574 // May only be called once per thread. 575 void set_name(const char* format, ...); 576 virtual char* name() const { return _name == NULL ? (char*)"Unknown Thread" : _name; } 577 }; 578 579 // Worker threads are named and have an id of an assigned work. 580 class WorkerThread: public NamedThread { 581 private: 582 uint _id; 583 public: 584 WorkerThread() : _id(0) { } 585 void set_id(uint work_id) { _id = work_id; } 586 uint id() const { return _id; } 587 }; 588 589 // A single WatcherThread is used for simulating timer interrupts. 590 class WatcherThread: public Thread { 591 friend class VMStructs; 592 public: 593 virtual void run(); 594 595 private: 596 static WatcherThread* _watcher_thread; 597 598 static bool _should_terminate; 599 public: 600 enum SomeConstants { 601 delay_interval = 10 // interrupt delay in milliseconds 602 }; 603 604 // Constructor 605 WatcherThread(); 606 607 // Tester 608 bool is_Watcher_thread() const { return true; } 609 610 // Printing 611 char* name() const { return (char*)"VM Periodic Task Thread"; } 612 void print_on(outputStream* st) const; 613 void print() const { print_on(tty); } 614 615 // Returns the single instance of WatcherThread 616 static WatcherThread* watcher_thread() { return _watcher_thread; } 617 618 // Create and start the single instance of WatcherThread, or stop it on shutdown 619 static void start(); 620 static void stop(); 621 }; 622 623 624 class CompilerThread; 625 626 typedef void (*ThreadFunction)(JavaThread*, TRAPS); 627 628 class JavaThread: public Thread { 629 friend class VMStructs; 630 private: 631 JavaThread* _next; // The next thread in the Threads list 632 oop _threadObj; // The Java level thread object 633 634 #ifdef ASSERT 635 private: 636 int _java_call_counter; 637 638 public: 639 int java_call_counter() { return _java_call_counter; } 640 void inc_java_call_counter() { _java_call_counter++; } 641 void dec_java_call_counter() { 642 assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper"); 643 _java_call_counter--; 644 } 645 private: // restore original namespace restriction 646 #endif // ifdef ASSERT 647 648 #ifndef PRODUCT 649 public: 650 enum { 651 jump_ring_buffer_size = 16 652 }; 653 private: // restore original namespace restriction 654 #endif 655 656 JavaFrameAnchor _anchor; // Encapsulation of current java frame and it state 657 658 ThreadFunction _entry_point; 659 660 JNIEnv _jni_environment; 661 662 // Deopt support 663 DeoptResourceMark* _deopt_mark; // Holds special ResourceMark for deoptimization 664 665 intptr_t* _must_deopt_id; // id of frame that needs to be deopted once we 666 // transition out of native 667 668 vframeArray* _vframe_array_head; // Holds the heap of the active vframeArrays 669 vframeArray* _vframe_array_last; // Holds last vFrameArray we popped 670 // Because deoptimization is lazy we must save jvmti requests to set locals 671 // in compiled frames until we deoptimize and we have an interpreter frame. 672 // This holds the pointer to array (yeah like there might be more than one) of 673 // description of compiled vframes that have locals that need to be updated. 674 GrowableArray<jvmtiDeferredLocalVariableSet*>* _deferred_locals_updates; 675 676 // Handshake value for fixing 6243940. We need a place for the i2c 677 // adapter to store the callee methodOop. This value is NEVER live 678 // across a gc point so it does NOT have to be gc'd 679 // The handshake is open ended since we can't be certain that it will 680 // be NULLed. This is because we rarely ever see the race and end up 681 // in handle_wrong_method which is the backend of the handshake. See 682 // code in i2c adapters and handle_wrong_method. 683 684 methodOop _callee_target; 685 686 // Oop results of VM runtime calls 687 oop _vm_result; // Used to pass back an oop result into Java code, GC-preserved 688 oop _vm_result_2; // Used to pass back an oop result into Java code, GC-preserved 689 690 MonitorChunk* _monitor_chunks; // Contains the off stack monitors 691 // allocated during deoptimization 692 // and by JNI_MonitorEnter/Exit 693 694 // Async. requests support 695 enum AsyncRequests { 696 _no_async_condition = 0, 697 _async_exception, 698 _async_unsafe_access_error 699 }; 700 AsyncRequests _special_runtime_exit_condition; // Enum indicating pending async. request 701 oop _pending_async_exception; 702 703 // Safepoint support 704 public: // Expose _thread_state for SafeFetchInt() 705 volatile JavaThreadState _thread_state; 706 private: 707 ThreadSafepointState *_safepoint_state; // Holds information about a thread during a safepoint 708 address _saved_exception_pc; // Saved pc of instruction where last implicit exception happened 709 710 // JavaThread termination support 711 enum TerminatedTypes { 712 _not_terminated = 0xDEAD - 2, 713 _thread_exiting, // JavaThread::exit() has been called for this thread 714 _thread_terminated, // JavaThread is removed from thread list 715 _vm_exited // JavaThread is still executing native code, but VM is terminated 716 // only VM_Exit can set _vm_exited 717 }; 718 719 // In general a JavaThread's _terminated field transitions as follows: 720 // 721 // _not_terminated => _thread_exiting => _thread_terminated 722 // 723 // _vm_exited is a special value to cover the case of a JavaThread 724 // executing native code after the VM itself is terminated. 725 TerminatedTypes _terminated; 726 // suspend/resume support 727 volatile bool _suspend_equivalent; // Suspend equivalent condition 728 jint _in_deopt_handler; // count of deoptimization 729 // handlers thread is in 730 volatile bool _doing_unsafe_access; // Thread may fault due to unsafe access 731 bool _do_not_unlock_if_synchronized; // Do not unlock the receiver of a synchronized method (since it was 732 // never locked) when throwing an exception. Used by interpreter only. 733 734 // Flag to mark a JNI thread in the process of attaching - See CR 6404306 735 // This flag is never set true other than at construction, and in that case 736 // is shortly thereafter set false 737 volatile bool _is_attaching; 738 739 public: 740 // State of the stack guard pages for this thread. 741 enum StackGuardState { 742 stack_guard_unused, // not needed 743 stack_guard_yellow_disabled,// disabled (temporarily) after stack overflow 744 stack_guard_enabled // enabled 745 }; 746 747 private: 748 749 StackGuardState _stack_guard_state; 750 751 // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is 752 // used to temp. parsing values into and out of the runtime system during exception handling for compiled 753 // code) 754 volatile oop _exception_oop; // Exception thrown in compiled code 755 volatile address _exception_pc; // PC where exception happened 756 volatile address _exception_handler_pc; // PC for handler of exception 757 volatile int _exception_stack_size; // Size of frame where exception happened 758 759 // support for compilation 760 bool _is_compiling; // is true if a compilation is active inthis thread (one compilation per thread possible) 761 762 // support for JNI critical regions 763 jint _jni_active_critical; // count of entries into JNI critical region 764 765 // For deadlock detection. 766 int _depth_first_number; 767 768 // JVMTI PopFrame support 769 // This is set to popframe_pending to signal that top Java frame should be popped immediately 770 int _popframe_condition; 771 772 #ifndef PRODUCT 773 int _jmp_ring_index; 774 struct { 775 // We use intptr_t instead of address so debugger doesn't try and display strings 776 intptr_t _target; 777 intptr_t _instruction; 778 const char* _file; 779 int _line; 780 } _jmp_ring[ jump_ring_buffer_size ]; 781 #endif /* PRODUCT */ 782 783 #ifndef SERIALGC 784 // Support for G1 barriers 785 786 ObjPtrQueue _satb_mark_queue; // Thread-local log for SATB barrier. 787 // Set of all such queues. 788 static SATBMarkQueueSet _satb_mark_queue_set; 789 790 DirtyCardQueue _dirty_card_queue; // Thread-local log for dirty cards. 791 // Set of all such queues. 792 static DirtyCardQueueSet _dirty_card_queue_set; 793 794 void flush_barrier_queues(); 795 #endif // !SERIALGC 796 797 friend class VMThread; 798 friend class ThreadWaitTransition; 799 friend class VM_Exit; 800 801 void initialize(); // Initialized the instance variables 802 803 public: 804 // Constructor 805 JavaThread(bool is_attaching = false); // for main thread and JNI attached threads 806 JavaThread(ThreadFunction entry_point, size_t stack_size = 0); 807 ~JavaThread(); 808 809 #ifdef ASSERT 810 // verify this JavaThread hasn't be published in the Threads::list yet 811 void verify_not_published(); 812 #endif 813 814 //JNI functiontable getter/setter for JVMTI jni function table interception API. 815 void set_jni_functions(struct JNINativeInterface_* functionTable) { 816 _jni_environment.functions = functionTable; 817 } 818 struct JNINativeInterface_* get_jni_functions() { 819 return (struct JNINativeInterface_ *)_jni_environment.functions; 820 } 821 822 // Executes Shutdown.shutdown() 823 void invoke_shutdown_hooks(); 824 825 // Cleanup on thread exit 826 enum ExitType { 827 normal_exit, 828 jni_detach 829 }; 830 void exit(bool destroy_vm, ExitType exit_type = normal_exit); 831 832 void cleanup_failed_attach_current_thread(); 833 834 // Testers 835 virtual bool is_Java_thread() const { return true; } 836 837 // compilation 838 void set_is_compiling(bool f) { _is_compiling = f; } 839 bool is_compiling() const { return _is_compiling; } 840 841 // Thread chain operations 842 JavaThread* next() const { return _next; } 843 void set_next(JavaThread* p) { _next = p; } 844 845 // Thread oop. threadObj() can be NULL for initial JavaThread 846 // (or for threads attached via JNI) 847 oop threadObj() const { return _threadObj; } 848 void set_threadObj(oop p) { _threadObj = p; } 849 850 ThreadPriority java_priority() const; // Read from threadObj() 851 852 // Prepare thread and add to priority queue. If a priority is 853 // not specified, use the priority of the thread object. Threads_lock 854 // must be held while this function is called. 855 void prepare(jobject jni_thread, ThreadPriority prio=NoPriority); 856 857 void set_saved_exception_pc(address pc) { _saved_exception_pc = pc; } 858 address saved_exception_pc() { return _saved_exception_pc; } 859 860 861 ThreadFunction entry_point() const { return _entry_point; } 862 863 // Allocates a new Java level thread object for this thread. thread_name may be NULL. 864 void allocate_threadObj(Handle thread_group, char* thread_name, bool daemon, TRAPS); 865 866 // Last frame anchor routines 867 868 JavaFrameAnchor* frame_anchor(void) { return &_anchor; } 869 870 // last_Java_sp 871 bool has_last_Java_frame() const { return _anchor.has_last_Java_frame(); } 872 intptr_t* last_Java_sp() const { return _anchor.last_Java_sp(); } 873 874 // last_Java_pc 875 876 address last_Java_pc(void) { return _anchor.last_Java_pc(); } 877 878 // Safepoint support 879 JavaThreadState thread_state() const { return _thread_state; } 880 void set_thread_state(JavaThreadState s) { _thread_state=s; } 881 ThreadSafepointState *safepoint_state() const { return _safepoint_state; } 882 void set_safepoint_state(ThreadSafepointState *state) { _safepoint_state = state; } 883 bool is_at_poll_safepoint() { return _safepoint_state->is_at_poll_safepoint(); } 884 885 // thread has called JavaThread::exit() or is terminated 886 bool is_exiting() { return _terminated == _thread_exiting || is_terminated(); } 887 // thread is terminated (no longer on the threads list); we compare 888 // against the two non-terminated values so that a freed JavaThread 889 // will also be considered terminated. 890 bool is_terminated() { return _terminated != _not_terminated && _terminated != _thread_exiting; } 891 void set_terminated(TerminatedTypes t) { _terminated = t; } 892 // special for Threads::remove() which is static: 893 void set_terminated_value() { _terminated = _thread_terminated; } 894 void block_if_vm_exited(); 895 896 bool doing_unsafe_access() { return _doing_unsafe_access; } 897 void set_doing_unsafe_access(bool val) { _doing_unsafe_access = val; } 898 899 bool do_not_unlock_if_synchronized() { return _do_not_unlock_if_synchronized; } 900 void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; } 901 902 903 // Suspend/resume support for JavaThread 904 905 private: 906 void set_ext_suspended() { set_suspend_flag (_ext_suspended); } 907 void clear_ext_suspended() { clear_suspend_flag(_ext_suspended); } 908 909 public: 910 void java_suspend(); 911 void java_resume(); 912 int java_suspend_self(); 913 914 void check_and_wait_while_suspended() { 915 assert(JavaThread::current() == this, "sanity check"); 916 917 bool do_self_suspend; 918 do { 919 // were we externally suspended while we were waiting? 920 do_self_suspend = handle_special_suspend_equivalent_condition(); 921 if (do_self_suspend) { 922 // don't surprise the thread that suspended us by returning 923 java_suspend_self(); 924 set_suspend_equivalent(); 925 } 926 } while (do_self_suspend); 927 } 928 static void check_safepoint_and_suspend_for_native_trans(JavaThread *thread); 929 // Check for async exception in addition to safepoint and suspend request. 930 static void check_special_condition_for_native_trans(JavaThread *thread); 931 932 bool is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits); 933 bool is_ext_suspend_completed_with_lock(uint32_t *bits) { 934 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag); 935 // Warning: is_ext_suspend_completed() may temporarily drop the 936 // SR_lock to allow the thread to reach a stable thread state if 937 // it is currently in a transient thread state. 938 return is_ext_suspend_completed(false /*!called_by_wait */, 939 SuspendRetryDelay, bits); 940 } 941 942 // We cannot allow wait_for_ext_suspend_completion() to run forever or 943 // we could hang. SuspendRetryCount and SuspendRetryDelay are normally 944 // passed as the count and delay parameters. Experiments with specific 945 // calls to wait_for_ext_suspend_completion() can be done by passing 946 // other values in the code. Experiments with all calls can be done 947 // via the appropriate -XX options. 948 bool wait_for_ext_suspend_completion(int count, int delay, uint32_t *bits); 949 950 void set_external_suspend() { set_suspend_flag (_external_suspend); } 951 void clear_external_suspend() { clear_suspend_flag(_external_suspend); } 952 953 void set_deopt_suspend() { set_suspend_flag (_deopt_suspend); } 954 void clear_deopt_suspend() { clear_suspend_flag(_deopt_suspend); } 955 bool is_deopt_suspend() { return (_suspend_flags & _deopt_suspend) != 0; } 956 957 bool is_external_suspend() const { 958 return (_suspend_flags & _external_suspend) != 0; 959 } 960 // Whenever a thread transitions from native to vm/java it must suspend 961 // if external|deopt suspend is present. 962 bool is_suspend_after_native() const { 963 return (_suspend_flags & (_external_suspend | _deopt_suspend) ) != 0; 964 } 965 966 // external suspend request is completed 967 bool is_ext_suspended() const { 968 return (_suspend_flags & _ext_suspended) != 0; 969 } 970 971 bool is_external_suspend_with_lock() const { 972 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag); 973 return is_external_suspend(); 974 } 975 976 // Special method to handle a pending external suspend request 977 // when a suspend equivalent condition lifts. 978 bool handle_special_suspend_equivalent_condition() { 979 assert(is_suspend_equivalent(), 980 "should only be called in a suspend equivalence condition"); 981 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag); 982 bool ret = is_external_suspend(); 983 if (!ret) { 984 // not about to self-suspend so clear suspend equivalence 985 clear_suspend_equivalent(); 986 } 987 // implied else: 988 // We have a pending external suspend request so we leave the 989 // suspend_equivalent flag set until java_suspend_self() sets 990 // the ext_suspended flag and clears the suspend_equivalent 991 // flag. This insures that wait_for_ext_suspend_completion() 992 // will return consistent values. 993 return ret; 994 } 995 996 // utility methods to see if we are doing some kind of suspension 997 bool is_being_ext_suspended() const { 998 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag); 999 return is_ext_suspended() || is_external_suspend(); 1000 } 1001 1002 bool is_suspend_equivalent() const { return _suspend_equivalent; } 1003 1004 void set_suspend_equivalent() { _suspend_equivalent = true; }; 1005 void clear_suspend_equivalent() { _suspend_equivalent = false; }; 1006 1007 // Thread.stop support 1008 void send_thread_stop(oop throwable); 1009 AsyncRequests clear_special_runtime_exit_condition() { 1010 AsyncRequests x = _special_runtime_exit_condition; 1011 _special_runtime_exit_condition = _no_async_condition; 1012 return x; 1013 } 1014 1015 // Are any async conditions present? 1016 bool has_async_condition() { return (_special_runtime_exit_condition != _no_async_condition); } 1017 1018 void check_and_handle_async_exceptions(bool check_unsafe_error = true); 1019 1020 // these next two are also used for self-suspension and async exception support 1021 void handle_special_runtime_exit_condition(bool check_asyncs = true); 1022 1023 // Return true if JavaThread has an asynchronous condition or 1024 // if external suspension is requested. 1025 bool has_special_runtime_exit_condition() { 1026 // We call is_external_suspend() last since external suspend should 1027 // be less common. Because we don't use is_external_suspend_with_lock 1028 // it is possible that we won't see an asynchronous external suspend 1029 // request that has just gotten started, i.e., SR_lock grabbed but 1030 // _external_suspend field change either not made yet or not visible 1031 // yet. However, this is okay because the request is asynchronous and 1032 // we will see the new flag value the next time through. It's also 1033 // possible that the external suspend request is dropped after 1034 // we have checked is_external_suspend(), we will recheck its value 1035 // under SR_lock in java_suspend_self(). 1036 return (_special_runtime_exit_condition != _no_async_condition) || 1037 is_external_suspend() || is_deopt_suspend(); 1038 } 1039 1040 void set_pending_unsafe_access_error() { _special_runtime_exit_condition = _async_unsafe_access_error; } 1041 1042 void set_pending_async_exception(oop e) { 1043 _pending_async_exception = e; 1044 _special_runtime_exit_condition = _async_exception; 1045 set_has_async_exception(); 1046 } 1047 1048 // Fast-locking support 1049 bool is_lock_owned(address adr) const; 1050 1051 // Accessors for vframe array top 1052 // The linked list of vframe arrays are sorted on sp. This means when we 1053 // unpack the head must contain the vframe array to unpack. 1054 void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; } 1055 vframeArray* vframe_array_head() const { return _vframe_array_head; } 1056 1057 // Side structure for defering update of java frame locals until deopt occurs 1058 GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred_locals() const { return _deferred_locals_updates; } 1059 void set_deferred_locals(GrowableArray<jvmtiDeferredLocalVariableSet *>* vf) { _deferred_locals_updates = vf; } 1060 1061 // These only really exist to make debugging deopt problems simpler 1062 1063 void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; } 1064 vframeArray* vframe_array_last() const { return _vframe_array_last; } 1065 1066 // The special resourceMark used during deoptimization 1067 1068 void set_deopt_mark(DeoptResourceMark* value) { _deopt_mark = value; } 1069 DeoptResourceMark* deopt_mark(void) { return _deopt_mark; } 1070 1071 intptr_t* must_deopt_id() { return _must_deopt_id; } 1072 void set_must_deopt_id(intptr_t* id) { _must_deopt_id = id; } 1073 void clear_must_deopt_id() { _must_deopt_id = NULL; } 1074 1075 methodOop callee_target() const { return _callee_target; } 1076 void set_callee_target (methodOop x) { _callee_target = x; } 1077 1078 // Oop results of vm runtime calls 1079 oop vm_result() const { return _vm_result; } 1080 void set_vm_result (oop x) { _vm_result = x; } 1081 1082 oop vm_result_2() const { return _vm_result_2; } 1083 void set_vm_result_2 (oop x) { _vm_result_2 = x; } 1084 1085 // Exception handling for compiled methods 1086 oop exception_oop() const { return _exception_oop; } 1087 int exception_stack_size() const { return _exception_stack_size; } 1088 address exception_pc() const { return _exception_pc; } 1089 address exception_handler_pc() const { return _exception_handler_pc; } 1090 1091 void set_exception_oop(oop o) { _exception_oop = o; } 1092 void set_exception_pc(address a) { _exception_pc = a; } 1093 void set_exception_handler_pc(address a) { _exception_handler_pc = a; } 1094 void set_exception_stack_size(int size) { _exception_stack_size = size; } 1095 1096 // Stack overflow support 1097 inline size_t stack_available(address cur_sp); 1098 address stack_yellow_zone_base() 1099 { return (address)(stack_base() - (stack_size() - (stack_red_zone_size() + stack_yellow_zone_size()))); } 1100 size_t stack_yellow_zone_size() 1101 { return StackYellowPages * os::vm_page_size(); } 1102 address stack_red_zone_base() 1103 { return (address)(stack_base() - (stack_size() - stack_red_zone_size())); } 1104 size_t stack_red_zone_size() 1105 { return StackRedPages * os::vm_page_size(); } 1106 bool in_stack_yellow_zone(address a) 1107 { return (a <= stack_yellow_zone_base()) && (a >= stack_red_zone_base()); } 1108 bool in_stack_red_zone(address a) 1109 { return (a <= stack_red_zone_base()) && (a >= (address)((intptr_t)stack_base() - stack_size())); } 1110 1111 void create_stack_guard_pages(); 1112 void remove_stack_guard_pages(); 1113 1114 void enable_stack_yellow_zone(); 1115 void disable_stack_yellow_zone(); 1116 void enable_stack_red_zone(); 1117 void disable_stack_red_zone(); 1118 1119 inline bool stack_yellow_zone_disabled(); 1120 inline bool stack_yellow_zone_enabled(); 1121 1122 // Attempt to reguard the stack after a stack overflow may have occurred. 1123 // Returns true if (a) guard pages are not needed on this thread, (b) the 1124 // pages are already guarded, or (c) the pages were successfully reguarded. 1125 // Returns false if there is not enough stack space to reguard the pages, in 1126 // which case the caller should unwind a frame and try again. The argument 1127 // should be the caller's (approximate) sp. 1128 bool reguard_stack(address cur_sp); 1129 // Similar to above but see if current stackpoint is out of the guard area 1130 // and reguard if possible. 1131 bool reguard_stack(void); 1132 1133 // Misc. accessors/mutators 1134 void set_do_not_unlock(void) { _do_not_unlock_if_synchronized = true; } 1135 void clr_do_not_unlock(void) { _do_not_unlock_if_synchronized = false; } 1136 bool do_not_unlock(void) { return _do_not_unlock_if_synchronized; } 1137 1138 #ifndef PRODUCT 1139 void record_jump(address target, address instr, const char* file, int line); 1140 #endif /* PRODUCT */ 1141 1142 // For assembly stub generation 1143 static ByteSize threadObj_offset() { return byte_offset_of(JavaThread, _threadObj ); } 1144 #ifndef PRODUCT 1145 static ByteSize jmp_ring_index_offset() { return byte_offset_of(JavaThread, _jmp_ring_index ); } 1146 static ByteSize jmp_ring_offset() { return byte_offset_of(JavaThread, _jmp_ring ); } 1147 #endif /* PRODUCT */ 1148 static ByteSize jni_environment_offset() { return byte_offset_of(JavaThread, _jni_environment ); } 1149 static ByteSize last_Java_sp_offset() { 1150 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset(); 1151 } 1152 static ByteSize last_Java_pc_offset() { 1153 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset(); 1154 } 1155 static ByteSize frame_anchor_offset() { 1156 return byte_offset_of(JavaThread, _anchor); 1157 } 1158 static ByteSize callee_target_offset() { return byte_offset_of(JavaThread, _callee_target ); } 1159 static ByteSize vm_result_offset() { return byte_offset_of(JavaThread, _vm_result ); } 1160 static ByteSize vm_result_2_offset() { return byte_offset_of(JavaThread, _vm_result_2 ); } 1161 static ByteSize thread_state_offset() { return byte_offset_of(JavaThread, _thread_state ); } 1162 static ByteSize saved_exception_pc_offset() { return byte_offset_of(JavaThread, _saved_exception_pc ); } 1163 static ByteSize osthread_offset() { return byte_offset_of(JavaThread, _osthread ); } 1164 static ByteSize exception_oop_offset() { return byte_offset_of(JavaThread, _exception_oop ); } 1165 static ByteSize exception_pc_offset() { return byte_offset_of(JavaThread, _exception_pc ); } 1166 static ByteSize exception_handler_pc_offset() { return byte_offset_of(JavaThread, _exception_handler_pc); } 1167 static ByteSize exception_stack_size_offset() { return byte_offset_of(JavaThread, _exception_stack_size); } 1168 static ByteSize stack_guard_state_offset() { return byte_offset_of(JavaThread, _stack_guard_state ); } 1169 static ByteSize suspend_flags_offset() { return byte_offset_of(JavaThread, _suspend_flags ); } 1170 1171 static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); } 1172 1173 #ifndef SERIALGC 1174 static ByteSize satb_mark_queue_offset() { return byte_offset_of(JavaThread, _satb_mark_queue); } 1175 static ByteSize dirty_card_queue_offset() { return byte_offset_of(JavaThread, _dirty_card_queue); } 1176 #endif // !SERIALGC 1177 1178 // Returns the jni environment for this thread 1179 JNIEnv* jni_environment() { return &_jni_environment; } 1180 1181 static JavaThread* thread_from_jni_environment(JNIEnv* env) { 1182 JavaThread *thread_from_jni_env = (JavaThread*)((intptr_t)env - in_bytes(jni_environment_offset())); 1183 // Only return NULL if thread is off the thread list; starting to 1184 // exit should not return NULL. 1185 if (thread_from_jni_env->is_terminated()) { 1186 thread_from_jni_env->block_if_vm_exited(); 1187 return NULL; 1188 } else { 1189 return thread_from_jni_env; 1190 } 1191 } 1192 1193 // JNI critical regions. These can nest. 1194 bool in_critical() { return _jni_active_critical > 0; } 1195 void enter_critical() { assert(Thread::current() == this, 1196 "this must be current thread"); 1197 _jni_active_critical++; } 1198 void exit_critical() { assert(Thread::current() == this, 1199 "this must be current thread"); 1200 _jni_active_critical--; 1201 assert(_jni_active_critical >= 0, 1202 "JNI critical nesting problem?"); } 1203 1204 // For deadlock detection 1205 int depth_first_number() { return _depth_first_number; } 1206 void set_depth_first_number(int dfn) { _depth_first_number = dfn; } 1207 1208 private: 1209 void set_monitor_chunks(MonitorChunk* monitor_chunks) { _monitor_chunks = monitor_chunks; } 1210 1211 public: 1212 MonitorChunk* monitor_chunks() const { return _monitor_chunks; } 1213 void add_monitor_chunk(MonitorChunk* chunk); 1214 void remove_monitor_chunk(MonitorChunk* chunk); 1215 bool in_deopt_handler() const { return _in_deopt_handler > 0; } 1216 void inc_in_deopt_handler() { _in_deopt_handler++; } 1217 void dec_in_deopt_handler() { 1218 assert(_in_deopt_handler > 0, "mismatched deopt nesting"); 1219 if (_in_deopt_handler > 0) { // robustness 1220 _in_deopt_handler--; 1221 } 1222 } 1223 1224 private: 1225 void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; } 1226 1227 public: 1228 1229 // Frame iteration; calls the function f for all frames on the stack 1230 void frames_do(void f(frame*, const RegisterMap*)); 1231 1232 // Memory operations 1233 void oops_do(OopClosure* f, CodeBlobClosure* cf); 1234 1235 // Sweeper operations 1236 void nmethods_do(CodeBlobClosure* cf); 1237 1238 // Memory management operations 1239 void gc_epilogue(); 1240 void gc_prologue(); 1241 1242 // Misc. operations 1243 char* name() const { return (char*)get_thread_name(); } 1244 void print_on(outputStream* st) const; 1245 void print() const { print_on(tty); } 1246 void print_value(); 1247 void print_thread_state_on(outputStream* ) const PRODUCT_RETURN; 1248 void print_thread_state() const PRODUCT_RETURN; 1249 void print_on_error(outputStream* st, char* buf, int buflen) const; 1250 void verify(); 1251 const char* get_thread_name() const; 1252 private: 1253 // factor out low-level mechanics for use in both normal and error cases 1254 const char* get_thread_name_string(char* buf = NULL, int buflen = 0) const; 1255 public: 1256 const char* get_threadgroup_name() const; 1257 const char* get_parent_name() const; 1258 1259 // Accessing frames 1260 frame last_frame() { 1261 _anchor.make_walkable(this); 1262 return pd_last_frame(); 1263 } 1264 javaVFrame* last_java_vframe(RegisterMap* reg_map); 1265 1266 // Returns method at 'depth' java or native frames down the stack 1267 // Used for security checks 1268 klassOop security_get_caller_class(int depth); 1269 1270 // Print stack trace in external format 1271 void print_stack_on(outputStream* st); 1272 void print_stack() { print_stack_on(tty); } 1273 1274 // Print stack traces in various internal formats 1275 void trace_stack() PRODUCT_RETURN; 1276 void trace_stack_from(vframe* start_vf) PRODUCT_RETURN; 1277 void trace_frames() PRODUCT_RETURN; 1278 1279 // Returns the number of stack frames on the stack 1280 int depth() const; 1281 1282 // Function for testing deoptimization 1283 void deoptimize(); 1284 void make_zombies(); 1285 1286 void deoptimized_wrt_marked_nmethods(); 1287 1288 // Profiling operation (see fprofile.cpp) 1289 public: 1290 bool profile_last_Java_frame(frame* fr); 1291 1292 private: 1293 ThreadProfiler* _thread_profiler; 1294 private: 1295 friend class FlatProfiler; // uses both [gs]et_thread_profiler. 1296 friend class FlatProfilerTask; // uses get_thread_profiler. 1297 friend class ThreadProfilerMark; // uses get_thread_profiler. 1298 ThreadProfiler* get_thread_profiler() { return _thread_profiler; } 1299 ThreadProfiler* set_thread_profiler(ThreadProfiler* tp) { 1300 ThreadProfiler* result = _thread_profiler; 1301 _thread_profiler = tp; 1302 return result; 1303 } 1304 1305 // Static operations 1306 public: 1307 // Returns the running thread as a JavaThread 1308 static inline JavaThread* current(); 1309 1310 // Returns the active Java thread. Do not use this if you know you are calling 1311 // from a JavaThread, as it's slower than JavaThread::current. If called from 1312 // the VMThread, it also returns the JavaThread that instigated the VMThread's 1313 // operation. You may not want that either. 1314 static JavaThread* active(); 1315 1316 inline CompilerThread* as_CompilerThread(); 1317 1318 public: 1319 virtual void run(); 1320 void thread_main_inner(); 1321 1322 private: 1323 // PRIVILEGED STACK 1324 PrivilegedElement* _privileged_stack_top; 1325 GrowableArray<oop>* _array_for_gc; 1326 public: 1327 1328 // Returns the privileged_stack information. 1329 PrivilegedElement* privileged_stack_top() const { return _privileged_stack_top; } 1330 void set_privileged_stack_top(PrivilegedElement *e) { _privileged_stack_top = e; } 1331 void register_array_for_gc(GrowableArray<oop>* array) { _array_for_gc = array; } 1332 1333 public: 1334 // Thread local information maintained by JVMTI. 1335 void set_jvmti_thread_state(JvmtiThreadState *value) { _jvmti_thread_state = value; } 1336 // A JvmtiThreadState is lazily allocated. This jvmti_thread_state() 1337 // getter is used to get this JavaThread's JvmtiThreadState if it has 1338 // one which means NULL can be returned. JvmtiThreadState::state_for() 1339 // is used to get the specified JavaThread's JvmtiThreadState if it has 1340 // one or it allocates a new JvmtiThreadState for the JavaThread and 1341 // returns it. JvmtiThreadState::state_for() will return NULL only if 1342 // the specified JavaThread is exiting. 1343 JvmtiThreadState *jvmti_thread_state() const { return _jvmti_thread_state; } 1344 static ByteSize jvmti_thread_state_offset() { return byte_offset_of(JavaThread, _jvmti_thread_state); } 1345 void set_jvmti_get_loaded_classes_closure(JvmtiGetLoadedClassesClosure* value) { _jvmti_get_loaded_classes_closure = value; } 1346 JvmtiGetLoadedClassesClosure* get_jvmti_get_loaded_classes_closure() const { return _jvmti_get_loaded_classes_closure; } 1347 1348 // JVMTI PopFrame support 1349 // Setting and clearing popframe_condition 1350 // All of these enumerated values are bits. popframe_pending 1351 // indicates that a PopFrame() has been requested and not yet been 1352 // completed. popframe_processing indicates that that PopFrame() is in 1353 // the process of being completed. popframe_force_deopt_reexecution_bit 1354 // indicates that special handling is required when returning to a 1355 // deoptimized caller. 1356 enum PopCondition { 1357 popframe_inactive = 0x00, 1358 popframe_pending_bit = 0x01, 1359 popframe_processing_bit = 0x02, 1360 popframe_force_deopt_reexecution_bit = 0x04 1361 }; 1362 PopCondition popframe_condition() { return (PopCondition) _popframe_condition; } 1363 void set_popframe_condition(PopCondition c) { _popframe_condition = c; } 1364 void set_popframe_condition_bit(PopCondition c) { _popframe_condition |= c; } 1365 void clear_popframe_condition() { _popframe_condition = popframe_inactive; } 1366 static ByteSize popframe_condition_offset() { return byte_offset_of(JavaThread, _popframe_condition); } 1367 bool has_pending_popframe() { return (popframe_condition() & popframe_pending_bit) != 0; } 1368 bool popframe_forcing_deopt_reexecution() { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; } 1369 void clear_popframe_forcing_deopt_reexecution() { _popframe_condition &= ~popframe_force_deopt_reexecution_bit; } 1370 #ifdef CC_INTERP 1371 bool pop_frame_pending(void) { return ((_popframe_condition & popframe_pending_bit) != 0); } 1372 void clr_pop_frame_pending(void) { _popframe_condition = popframe_inactive; } 1373 bool pop_frame_in_process(void) { return ((_popframe_condition & popframe_processing_bit) != 0); } 1374 void set_pop_frame_in_process(void) { _popframe_condition |= popframe_processing_bit; } 1375 void clr_pop_frame_in_process(void) { _popframe_condition &= ~popframe_processing_bit; } 1376 #endif 1377 1378 private: 1379 // Saved incoming arguments to popped frame. 1380 // Used only when popped interpreted frame returns to deoptimized frame. 1381 void* _popframe_preserved_args; 1382 int _popframe_preserved_args_size; 1383 1384 public: 1385 void popframe_preserve_args(ByteSize size_in_bytes, void* start); 1386 void* popframe_preserved_args(); 1387 ByteSize popframe_preserved_args_size(); 1388 WordSize popframe_preserved_args_size_in_words(); 1389 void popframe_free_preserved_args(); 1390 1391 1392 private: 1393 JvmtiThreadState *_jvmti_thread_state; 1394 JvmtiGetLoadedClassesClosure* _jvmti_get_loaded_classes_closure; 1395 1396 // Used by the interpreter in fullspeed mode for frame pop, method 1397 // entry, method exit and single stepping support. This field is 1398 // only set to non-zero by the VM_EnterInterpOnlyMode VM operation. 1399 // It can be set to zero asynchronously (i.e., without a VM operation 1400 // or a lock) so we have to be very careful. 1401 int _interp_only_mode; 1402 1403 public: 1404 // used by the interpreter for fullspeed debugging support (see above) 1405 static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); } 1406 bool is_interp_only_mode() { return (_interp_only_mode != 0); } 1407 int get_interp_only_mode() { return _interp_only_mode; } 1408 void increment_interp_only_mode() { ++_interp_only_mode; } 1409 void decrement_interp_only_mode() { --_interp_only_mode; } 1410 1411 private: 1412 ThreadStatistics *_thread_stat; 1413 1414 public: 1415 ThreadStatistics* get_thread_stat() const { return _thread_stat; } 1416 1417 // Return a blocker object for which this thread is blocked parking. 1418 oop current_park_blocker(); 1419 1420 private: 1421 static size_t _stack_size_at_create; 1422 1423 public: 1424 static inline size_t stack_size_at_create(void) { 1425 return _stack_size_at_create; 1426 } 1427 static inline void set_stack_size_at_create(size_t value) { 1428 _stack_size_at_create = value; 1429 } 1430 1431 #ifndef SERIALGC 1432 // SATB marking queue support 1433 ObjPtrQueue& satb_mark_queue() { return _satb_mark_queue; } 1434 static SATBMarkQueueSet& satb_mark_queue_set() { 1435 return _satb_mark_queue_set; 1436 } 1437 1438 // Dirty card queue support 1439 DirtyCardQueue& dirty_card_queue() { return _dirty_card_queue; } 1440 static DirtyCardQueueSet& dirty_card_queue_set() { 1441 return _dirty_card_queue_set; 1442 } 1443 #endif // !SERIALGC 1444 1445 // Machine dependent stuff 1446 #include "incls/_thread_pd.hpp.incl" 1447 1448 public: 1449 void set_blocked_on_compilation(bool value) { 1450 _blocked_on_compilation = value; 1451 } 1452 1453 bool blocked_on_compilation() { 1454 return _blocked_on_compilation; 1455 } 1456 protected: 1457 bool _blocked_on_compilation; 1458 1459 1460 // JSR166 per-thread parker 1461 private: 1462 Parker* _parker; 1463 public: 1464 Parker* parker() { return _parker; } 1465 1466 // Biased locking support 1467 private: 1468 GrowableArray<MonitorInfo*>* _cached_monitor_info; 1469 public: 1470 GrowableArray<MonitorInfo*>* cached_monitor_info() { return _cached_monitor_info; } 1471 void set_cached_monitor_info(GrowableArray<MonitorInfo*>* info) { _cached_monitor_info = info; } 1472 1473 // clearing/querying jni attach status 1474 bool is_attaching() const { return _is_attaching; } 1475 void set_attached() { _is_attaching = false; OrderAccess::fence(); } 1476 private: 1477 // This field is used to determine if a thread has claimed 1478 // a par_id: it is -1 if the thread has not claimed a par_id; 1479 // otherwise its value is the par_id that has been claimed. 1480 int _claimed_par_id; 1481 public: 1482 int get_claimed_par_id() { return _claimed_par_id; } 1483 void set_claimed_par_id(int id) { _claimed_par_id = id;} 1484 }; 1485 1486 // Inline implementation of JavaThread::current 1487 inline JavaThread* JavaThread::current() { 1488 Thread* thread = ThreadLocalStorage::thread(); 1489 assert(thread != NULL && thread->is_Java_thread(), "just checking"); 1490 return (JavaThread*)thread; 1491 } 1492 1493 inline CompilerThread* JavaThread::as_CompilerThread() { 1494 assert(is_Compiler_thread(), "just checking"); 1495 return (CompilerThread*)this; 1496 } 1497 1498 inline bool JavaThread::stack_yellow_zone_disabled() { 1499 return _stack_guard_state == stack_guard_yellow_disabled; 1500 } 1501 1502 inline bool JavaThread::stack_yellow_zone_enabled() { 1503 #ifdef ASSERT 1504 if (os::uses_stack_guard_pages()) { 1505 assert(_stack_guard_state != stack_guard_unused, "guard pages must be in use"); 1506 } 1507 #endif 1508 return _stack_guard_state == stack_guard_enabled; 1509 } 1510 1511 inline size_t JavaThread::stack_available(address cur_sp) { 1512 // This code assumes java stacks grow down 1513 address low_addr; // Limit on the address for deepest stack depth 1514 if ( _stack_guard_state == stack_guard_unused) { 1515 low_addr = stack_base() - stack_size(); 1516 } else { 1517 low_addr = stack_yellow_zone_base(); 1518 } 1519 return cur_sp > low_addr ? cur_sp - low_addr : 0; 1520 } 1521 1522 // A JavaThread for low memory detection support 1523 class LowMemoryDetectorThread : public JavaThread { 1524 friend class VMStructs; 1525 public: 1526 LowMemoryDetectorThread(ThreadFunction entry_point) : JavaThread(entry_point) {}; 1527 1528 // Hide this thread from external view. 1529 bool is_hidden_from_external_view() const { return true; } 1530 }; 1531 1532 // A thread used for Compilation. 1533 class CompilerThread : public JavaThread { 1534 friend class VMStructs; 1535 private: 1536 CompilerCounters* _counters; 1537 1538 ciEnv* _env; 1539 CompileLog* _log; 1540 CompileTask* _task; 1541 CompileQueue* _queue; 1542 1543 public: 1544 1545 static CompilerThread* current(); 1546 1547 CompilerThread(CompileQueue* queue, CompilerCounters* counters); 1548 1549 bool is_Compiler_thread() const { return true; } 1550 // Hide this compiler thread from external view. 1551 bool is_hidden_from_external_view() const { return true; } 1552 1553 CompileQueue* queue() { return _queue; } 1554 CompilerCounters* counters() { return _counters; } 1555 1556 // Get/set the thread's compilation environment. 1557 ciEnv* env() { return _env; } 1558 void set_env(ciEnv* env) { _env = env; } 1559 1560 // Get/set the thread's logging information 1561 CompileLog* log() { return _log; } 1562 void init_log(CompileLog* log) { 1563 // Set once, for good. 1564 assert(_log == NULL, "set only once"); 1565 _log = log; 1566 } 1567 1568 #ifndef PRODUCT 1569 private: 1570 IdealGraphPrinter *_ideal_graph_printer; 1571 public: 1572 IdealGraphPrinter *ideal_graph_printer() { return _ideal_graph_printer; } 1573 void set_ideal_graph_printer(IdealGraphPrinter *n) { _ideal_graph_printer = n; } 1574 #endif 1575 1576 // Get/set the thread's current task 1577 CompileTask* task() { return _task; } 1578 void set_task(CompileTask* task) { _task = task; } 1579 }; 1580 1581 inline CompilerThread* CompilerThread::current() { 1582 return JavaThread::current()->as_CompilerThread(); 1583 } 1584 1585 1586 // The active thread queue. It also keeps track of the current used 1587 // thread priorities. 1588 class Threads: AllStatic { 1589 friend class VMStructs; 1590 private: 1591 static JavaThread* _thread_list; 1592 static int _number_of_threads; 1593 static int _number_of_non_daemon_threads; 1594 static int _return_code; 1595 1596 public: 1597 // Thread management 1598 // force_daemon is a concession to JNI, where we may need to add a 1599 // thread to the thread list before allocating its thread object 1600 static void add(JavaThread* p, bool force_daemon = false); 1601 static void remove(JavaThread* p); 1602 static bool includes(JavaThread* p); 1603 static JavaThread* first() { return _thread_list; } 1604 static void threads_do(ThreadClosure* tc); 1605 1606 // Initializes the vm and creates the vm thread 1607 static jint create_vm(JavaVMInitArgs* args, bool* canTryAgain); 1608 static void convert_vm_init_libraries_to_agents(); 1609 static void create_vm_init_libraries(); 1610 static void create_vm_init_agents(); 1611 static void shutdown_vm_agents(); 1612 static bool destroy_vm(); 1613 // Supported VM versions via JNI 1614 // Includes JNI_VERSION_1_1 1615 static jboolean is_supported_jni_version_including_1_1(jint version); 1616 // Does not include JNI_VERSION_1_1 1617 static jboolean is_supported_jni_version(jint version); 1618 1619 // Garbage collection 1620 static void follow_other_roots(void f(oop*)); 1621 1622 // Apply "f->do_oop" to all root oops in all threads. 1623 // This version may only be called by sequential code. 1624 static void oops_do(OopClosure* f, CodeBlobClosure* cf); 1625 // This version may be called by sequential or parallel code. 1626 static void possibly_parallel_oops_do(OopClosure* f, CodeBlobClosure* cf); 1627 // This creates a list of GCTasks, one per thread. 1628 static void create_thread_roots_tasks(GCTaskQueue* q); 1629 // This creates a list of GCTasks, one per thread, for marking objects. 1630 static void create_thread_roots_marking_tasks(GCTaskQueue* q); 1631 1632 // Apply "f->do_oop" to roots in all threads that 1633 // are part of compiled frames 1634 static void compiled_frame_oops_do(OopClosure* f, CodeBlobClosure* cf); 1635 1636 static void convert_hcode_pointers(); 1637 static void restore_hcode_pointers(); 1638 1639 // Sweeper 1640 static void nmethods_do(CodeBlobClosure* cf); 1641 1642 static void gc_epilogue(); 1643 static void gc_prologue(); 1644 1645 // Verification 1646 static void verify(); 1647 static void print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks); 1648 static void print(bool print_stacks, bool internal_format) { 1649 // this function is only used by debug.cpp 1650 print_on(tty, print_stacks, internal_format, false /* no concurrent lock printed */); 1651 } 1652 static void print_on_error(outputStream* st, Thread* current, char* buf, int buflen); 1653 1654 // Get Java threads that are waiting to enter a monitor. If doLock 1655 // is true, then Threads_lock is grabbed as needed. Otherwise, the 1656 // VM needs to be at a safepoint. 1657 static GrowableArray<JavaThread*>* get_pending_threads(int count, 1658 address monitor, bool doLock); 1659 1660 // Get owning Java thread from the monitor's owner field. If doLock 1661 // is true, then Threads_lock is grabbed as needed. Otherwise, the 1662 // VM needs to be at a safepoint. 1663 static JavaThread *owning_thread_from_monitor_owner(address owner, 1664 bool doLock); 1665 1666 // Number of threads on the active threads list 1667 static int number_of_threads() { return _number_of_threads; } 1668 // Number of non-daemon threads on the active threads list 1669 static int number_of_non_daemon_threads() { return _number_of_non_daemon_threads; } 1670 1671 // Deoptimizes all frames tied to marked nmethods 1672 static void deoptimized_wrt_marked_nmethods(); 1673 1674 }; 1675 1676 1677 // Thread iterator 1678 class ThreadClosure: public StackObj { 1679 public: 1680 virtual void do_thread(Thread* thread) = 0; 1681 }; 1682 1683 class SignalHandlerMark: public StackObj { 1684 private: 1685 Thread* _thread; 1686 public: 1687 SignalHandlerMark(Thread* t) { 1688 _thread = t; 1689 if (_thread) _thread->enter_signal_handler(); 1690 } 1691 ~SignalHandlerMark() { 1692 if (_thread) _thread->leave_signal_handler(); 1693 _thread = NULL; 1694 } 1695 }; 1696 1697 // ParkEvents are type-stable and immortal. 1698 // 1699 // Lifecycle: Once a ParkEvent is associated with a thread that ParkEvent remains 1700 // associated with the thread for the thread's entire lifetime - the relationship is 1701 // stable. A thread will be associated at most one ParkEvent. When the thread 1702 // expires, the ParkEvent moves to the EventFreeList. New threads attempt to allocate from 1703 // the EventFreeList before creating a new Event. Type-stability frees us from 1704 // worrying about stale Event or Thread references in the objectMonitor subsystem. 1705 // (A reference to ParkEvent is always valid, even though the event may no longer be associated 1706 // with the desired or expected thread. A key aspect of this design is that the callers of 1707 // park, unpark, etc must tolerate stale references and spurious wakeups). 1708 // 1709 // Only the "associated" thread can block (park) on the ParkEvent, although 1710 // any other thread can unpark a reachable parkevent. Park() is allowed to 1711 // return spuriously. In fact park-unpark a really just an optimization to 1712 // avoid unbounded spinning and surrender the CPU to be a polite system citizen. 1713 // A degenerate albeit "impolite" park-unpark implementation could simply return. 1714 // See http://blogs.sun.com/dave for more details. 1715 // 1716 // Eventually I'd like to eliminate Events and ObjectWaiters, both of which serve as 1717 // thread proxies, and simply make the THREAD structure type-stable and persistent. 1718 // Currently, we unpark events associated with threads, but ideally we'd just 1719 // unpark threads. 1720 // 1721 // The base-class, PlatformEvent, is platform-specific while the ParkEvent is 1722 // platform-independent. PlatformEvent provides park(), unpark(), etc., and 1723 // is abstract -- that is, a PlatformEvent should never be instantiated except 1724 // as part of a ParkEvent. 1725 // Equivalently we could have defined a platform-independent base-class that 1726 // exported Allocate(), Release(), etc. The platform-specific class would extend 1727 // that base-class, adding park(), unpark(), etc. 1728 // 1729 // A word of caution: The JVM uses 2 very similar constructs: 1730 // 1. ParkEvent are used for Java-level "monitor" synchronization. 1731 // 2. Parkers are used by JSR166-JUC park-unpark. 1732 // 1733 // We'll want to eventually merge these redundant facilities and use ParkEvent. 1734 1735 1736 class ParkEvent : public os::PlatformEvent { 1737 private: 1738 ParkEvent * FreeNext ; 1739 1740 // Current association 1741 Thread * AssociatedWith ; 1742 intptr_t RawThreadIdentity ; // LWPID etc 1743 volatile int Incarnation ; 1744 1745 // diagnostic : keep track of last thread to wake this thread. 1746 // this is useful for construction of dependency graphs. 1747 void * LastWaker ; 1748 1749 public: 1750 // MCS-CLH list linkage and Native Mutex/Monitor 1751 ParkEvent * volatile ListNext ; 1752 ParkEvent * volatile ListPrev ; 1753 volatile intptr_t OnList ; 1754 volatile int TState ; 1755 volatile int Notified ; // for native monitor construct 1756 volatile int IsWaiting ; // Enqueued on WaitSet 1757 1758 1759 private: 1760 static ParkEvent * volatile FreeList ; 1761 static volatile int ListLock ; 1762 1763 // It's prudent to mark the dtor as "private" 1764 // ensuring that it's not visible outside the package. 1765 // Unfortunately gcc warns about such usage, so 1766 // we revert to the less desirable "protected" visibility. 1767 // The other compilers accept private dtors. 1768 1769 protected: // Ensure dtor is never invoked 1770 ~ParkEvent() { guarantee (0, "invariant") ; } 1771 1772 ParkEvent() : PlatformEvent() { 1773 AssociatedWith = NULL ; 1774 FreeNext = NULL ; 1775 ListNext = NULL ; 1776 ListPrev = NULL ; 1777 OnList = 0 ; 1778 TState = 0 ; 1779 Notified = 0 ; 1780 IsWaiting = 0 ; 1781 } 1782 1783 // We use placement-new to force ParkEvent instances to be 1784 // aligned on 256-byte address boundaries. This ensures that the least 1785 // significant byte of a ParkEvent address is always 0. 1786 1787 void * operator new (size_t sz) ; 1788 void operator delete (void * a) ; 1789 1790 public: 1791 static ParkEvent * Allocate (Thread * t) ; 1792 static void Release (ParkEvent * e) ; 1793 } ;