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 JvmtiThreadState; 66 class ThreadStatistics; 67 class ConcurrentLocksDump; 68 class ParkEvent; 69 class Parker; 70 class MonitorInfo; 71 72 class ciEnv; 73 class CompileThread; 74 class CompileLog; 75 class CompileTask; 76 class CompileQueue; 77 class CompilerCounters; 78 79 class vframeArray; 80 class vframe; 81 class javaVFrame; 82 83 class DeoptResourceMark; 84 class jvmtiDeferredLocalVariableSet; 85 86 class GCTaskQueue; 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 // - GCTaskThread 112 // - WatcherThread 113 // - JfrThreadSampler 114 // 115 // All Thread subclasses must be either JavaThread or NonJavaThread. 116 // This means !t->is_Java_thread() iff t is a NonJavaThread, or t is 117 // a partially constructed/destroyed Thread. 118 119 // Thread execution sequence and actions: 120 // All threads: 121 // - thread_native_entry // per-OS native entry point 122 // - stack initialization 123 // - other OS-level initialization (signal masks etc) 124 // - handshake with creating thread (if not started suspended) 125 // - this->call_run() // common shared entry point 126 // - shared common initialization 127 // - this->pre_run() // virtual per-thread-type initialization 128 // - this->run() // virtual per-thread-type "main" logic 129 // - shared common tear-down 130 // - this->post_run() // virtual per-thread-type tear-down 131 // - // 'this' no longer referenceable 132 // - OS-level tear-down (minimal) 133 // - final logging 134 // 135 // For JavaThread: 136 // - this->run() // virtual but not normally overridden 137 // - this->thread_main_inner() // extra call level to ensure correct stack calculations 138 // - this->entry_point() // set differently for each kind of JavaThread 139 140 class Thread: public ThreadShadow { 141 friend class VMStructs; 142 friend class JVMCIVMStructs; 143 private: 144 145 #ifndef USE_LIBRARY_BASED_TLS_ONLY 146 // Current thread is maintained as a thread-local variable 147 static THREAD_LOCAL_DECL Thread* _thr_current; 148 #endif 149 150 // Thread local data area available to the GC. The internal 151 // structure and contents of this data area is GC-specific. 152 // Only GC and GC barrier code should access this data area. 153 GCThreadLocalData _gc_data; 154 155 public: 156 static ByteSize gc_data_offset() { 157 return byte_offset_of(Thread, _gc_data); 158 } 159 160 template <typename T> T* gc_data() { 161 STATIC_ASSERT(sizeof(T) <= sizeof(_gc_data)); 162 return reinterpret_cast<T*>(&_gc_data); 163 } 164 165 // Exception handling 166 // (Note: _pending_exception and friends are in ThreadShadow) 167 //oop _pending_exception; // pending exception for current thread 168 // const char* _exception_file; // file information for exception (debugging only) 169 // int _exception_line; // line information for exception (debugging only) 170 protected: 171 172 DEBUG_ONLY(static Thread* _starting_thread;) 173 174 // Support for forcing alignment of thread objects for biased locking 175 void* _real_malloc_address; 176 177 // JavaThread lifecycle support: 178 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 179 friend class ScanHazardPtrGatherProtectedThreadsClosure; // for cmpxchg_threads_hazard_ptr(), get_threads_hazard_ptr(), is_hazard_ptr_tagged() access 180 friend class ScanHazardPtrGatherThreadsListClosure; // for get_threads_hazard_ptr(), untag_hazard_ptr() access 181 friend class ScanHazardPtrPrintMatchingThreadsClosure; // for get_threads_hazard_ptr(), is_hazard_ptr_tagged() access 182 friend class ThreadsSMRSupport; // for _nested_threads_hazard_ptr_cnt, _threads_hazard_ptr, _threads_list_ptr access 183 184 ThreadsList* volatile _threads_hazard_ptr; 185 SafeThreadsListPtr* _threads_list_ptr; 186 ThreadsList* cmpxchg_threads_hazard_ptr(ThreadsList* exchange_value, ThreadsList* compare_value); 187 ThreadsList* get_threads_hazard_ptr(); 188 void set_threads_hazard_ptr(ThreadsList* new_list); 189 static bool is_hazard_ptr_tagged(ThreadsList* list) { 190 return (intptr_t(list) & intptr_t(1)) == intptr_t(1); 191 } 192 static ThreadsList* tag_hazard_ptr(ThreadsList* list) { 193 return (ThreadsList*)(intptr_t(list) | intptr_t(1)); 194 } 195 static ThreadsList* untag_hazard_ptr(ThreadsList* list) { 196 return (ThreadsList*)(intptr_t(list) & ~intptr_t(1)); 197 } 198 // This field is enabled via -XX:+EnableThreadSMRStatistics: 199 uint _nested_threads_hazard_ptr_cnt; 200 void dec_nested_threads_hazard_ptr_cnt() { 201 assert(_nested_threads_hazard_ptr_cnt != 0, "mismatched {dec,inc}_nested_threads_hazard_ptr_cnt()"); 202 _nested_threads_hazard_ptr_cnt--; 203 } 204 void inc_nested_threads_hazard_ptr_cnt() { 205 _nested_threads_hazard_ptr_cnt++; 206 } 207 uint nested_threads_hazard_ptr_cnt() { 208 return _nested_threads_hazard_ptr_cnt; 209 } 210 211 public: 212 void* operator new(size_t size) throw() { return allocate(size, true); } 213 void* operator new(size_t size, const std::nothrow_t& nothrow_constant) throw() { 214 return allocate(size, false); } 215 void operator delete(void* p); 216 217 protected: 218 static void* allocate(size_t size, bool throw_excpt, MEMFLAGS flags = mtThread); 219 private: 220 221 // *************************************************************** 222 // Suspend and resume support 223 // *************************************************************** 224 // 225 // VM suspend/resume no longer exists - it was once used for various 226 // things including safepoints but was deprecated and finally removed 227 // in Java 7. Because VM suspension was considered "internal" Java-level 228 // suspension was considered "external", and this legacy naming scheme 229 // remains. 230 // 231 // External suspend/resume requests come from JVM_SuspendThread, 232 // JVM_ResumeThread, JVMTI SuspendThread, and finally JVMTI 233 // ResumeThread. External 234 // suspend requests cause _external_suspend to be set and external 235 // resume requests cause _external_suspend to be cleared. 236 // External suspend requests do not nest on top of other external 237 // suspend requests. The higher level APIs reject suspend requests 238 // for already suspended threads. 239 // 240 // The external_suspend 241 // flag is checked by has_special_runtime_exit_condition() and java thread 242 // will self-suspend when handle_special_runtime_exit_condition() is 243 // called. Most uses of the _thread_blocked state in JavaThreads are 244 // considered the same as being externally suspended; if the blocking 245 // condition lifts, the JavaThread will self-suspend. Other places 246 // where VM checks for external_suspend include: 247 // + mutex granting (do not enter monitors when thread is suspended) 248 // + state transitions from _thread_in_native 249 // 250 // In general, java_suspend() does not wait for an external suspend 251 // request to complete. When it returns, the only guarantee is that 252 // the _external_suspend field is true. 253 // 254 // wait_for_ext_suspend_completion() is used to wait for an external 255 // suspend request to complete. External suspend requests are usually 256 // followed by some other interface call that requires the thread to 257 // be quiescent, e.g., GetCallTrace(). By moving the "wait time" into 258 // the interface that requires quiescence, we give the JavaThread a 259 // chance to self-suspend before we need it to be quiescent. This 260 // improves overall suspend/query performance. 261 // 262 // _suspend_flags controls the behavior of java_ suspend/resume. 263 // It must be set under the protection of SR_lock. Read from the flag is 264 // OK without SR_lock as long as the value is only used as a hint. 265 // (e.g., check _external_suspend first without lock and then recheck 266 // inside SR_lock and finish the suspension) 267 // 268 // _suspend_flags is also overloaded for other "special conditions" so 269 // that a single check indicates whether any special action is needed 270 // eg. for async exceptions. 271 // ------------------------------------------------------------------- 272 // Notes: 273 // 1. The suspend/resume logic no longer uses ThreadState in OSThread 274 // but we still update its value to keep other part of the system (mainly 275 // JVMTI) happy. ThreadState is legacy code (see notes in 276 // osThread.hpp). 277 // 278 // 2. It would be more natural if set_external_suspend() is private and 279 // part of java_suspend(), but that probably would affect the suspend/query 280 // performance. Need more investigation on this. 281 282 // suspend/resume lock: used for self-suspend 283 Monitor* _SR_lock; 284 285 protected: 286 enum SuspendFlags { 287 // NOTE: avoid using the sign-bit as cc generates different test code 288 // when the sign-bit is used, and sometimes incorrectly - see CR 6398077 289 290 _external_suspend = 0x20000000U, // thread is asked to self suspend 291 _ext_suspended = 0x40000000U, // thread has self-suspended 292 293 _has_async_exception = 0x00000001U, // there is a pending async exception 294 _critical_native_unlock = 0x00000002U, // Must call back to unlock JNI critical lock 295 296 _trace_flag = 0x00000004U // call tracing backend 297 }; 298 299 // various suspension related flags - atomically updated 300 // overloaded for async exception checking in check_special_condition_for_native_trans. 301 volatile uint32_t _suspend_flags; 302 303 private: 304 int _num_nested_signal; 305 306 DEBUG_ONLY(bool _suspendible_thread;) 307 308 public: 309 void enter_signal_handler() { _num_nested_signal++; } 310 void leave_signal_handler() { _num_nested_signal--; } 311 bool is_inside_signal_handler() const { return _num_nested_signal > 0; } 312 313 // Determines if a heap allocation failure will be retried 314 // (e.g., by deoptimizing and re-executing in the interpreter). 315 // In this case, the failed allocation must raise 316 // Universe::out_of_memory_error_retry() and omit side effects 317 // such as JVMTI events and handling -XX:+HeapDumpOnOutOfMemoryError 318 // and -XX:OnOutOfMemoryError. 319 virtual bool in_retryable_allocation() const { return false; } 320 321 #ifdef ASSERT 322 void set_suspendible_thread() { 323 _suspendible_thread = true; 324 } 325 326 void clear_suspendible_thread() { 327 _suspendible_thread = false; 328 } 329 330 bool is_suspendible_thread() { return _suspendible_thread; } 331 #endif 332 333 private: 334 // Active_handles points to a block of handles 335 JNIHandleBlock* _active_handles; 336 337 // One-element thread local free list 338 JNIHandleBlock* _free_handle_block; 339 340 // Point to the last handle mark 341 HandleMark* _last_handle_mark; 342 343 // Claim value for parallel iteration over threads. 344 uintx _threads_do_token; 345 346 // Support for GlobalCounter 347 private: 348 volatile uintx _rcu_counter; 349 public: 350 volatile uintx* get_rcu_counter() { 351 return &_rcu_counter; 352 } 353 354 public: 355 void set_last_handle_mark(HandleMark* mark) { _last_handle_mark = mark; } 356 HandleMark* last_handle_mark() const { return _last_handle_mark; } 357 private: 358 359 #ifdef ASSERT 360 ICRefillVerifier* _missed_ic_stub_refill_verifier; 361 362 public: 363 ICRefillVerifier* missed_ic_stub_refill_verifier() { 364 return _missed_ic_stub_refill_verifier; 365 } 366 367 void set_missed_ic_stub_refill_verifier(ICRefillVerifier* verifier) { 368 _missed_ic_stub_refill_verifier = verifier; 369 } 370 #endif 371 372 private: 373 374 // debug support for checking if code does allow safepoints or not 375 // GC points in the VM can happen because of allocation, invoking a VM operation, or blocking on 376 // mutex, or blocking on an object synchronizer (Java locking). 377 // If !allow_safepoint(), then an assertion failure will happen in any of the above cases 378 // If !allow_allocation(), then an assertion failure will happen during allocation 379 // (Hence, !allow_safepoint() => !allow_allocation()). 380 // 381 // The two classes NoSafepointVerifier and No_Allocation_Verifier are used to set these counters. 382 // 383 NOT_PRODUCT(int _allow_safepoint_count;) // If 0, thread allow a safepoint to happen 384 debug_only(int _allow_allocation_count;) // If 0, the thread is allowed to allocate oops. 385 386 // Used by SkipGCALot class. 387 NOT_PRODUCT(bool _skip_gcalot;) // Should we elide gc-a-lot? 388 389 friend class NoAllocVerifier; 390 friend class NoSafepointVerifier; 391 friend class PauseNoSafepointVerifier; 392 friend class GCLocker; 393 394 volatile void* _polling_page; // Thread local polling page 395 396 ThreadLocalAllocBuffer _tlab; // Thread-local eden 397 jlong _allocated_bytes; // Cumulative number of bytes allocated on 398 // the Java heap 399 ThreadHeapSampler _heap_sampler; // For use when sampling the memory. 400 401 ThreadStatisticalInfo _statistical_info; // Statistics about the thread 402 403 JFR_ONLY(DEFINE_THREAD_LOCAL_FIELD_JFR;) // Thread-local data for jfr 404 405 int _vm_operation_started_count; // VM_Operation support 406 int _vm_operation_completed_count; // VM_Operation support 407 408 ObjectMonitor* _current_pending_monitor; // ObjectMonitor this thread 409 // is waiting to lock 410 bool _current_pending_monitor_is_from_java; // locking is from Java code 411 412 // ObjectMonitor on which this thread called Object.wait() 413 ObjectMonitor* _current_waiting_monitor; 414 415 // Private thread-local objectmonitor list - a simple cache organized as a SLL. 416 public: 417 ObjectMonitor* omFreeList; 418 int omFreeCount; // length of omFreeList 419 int omFreeProvision; // reload chunk size 420 ObjectMonitor* omInUseList; // SLL to track monitors in circulation 421 int omInUseCount; // length of omInUseList 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 // Casts 498 virtual WorkerThread* as_Worker_thread() const { return NULL; } 499 500 virtual char* name() const { return (char*)"Unknown thread"; } 501 502 // Returns the current thread (ASSERTS if NULL) 503 static inline Thread* current(); 504 // Returns the current thread, or NULL if not attached 505 static inline Thread* current_or_null(); 506 // Returns the current thread, or NULL if not attached, and is 507 // safe for use from signal-handlers 508 static inline Thread* current_or_null_safe(); 509 510 // Common thread operations 511 #ifdef ASSERT 512 static void check_for_dangling_thread_pointer(Thread *thread); 513 #endif 514 static void set_priority(Thread* thread, ThreadPriority priority); 515 static ThreadPriority get_priority(const Thread* const thread); 516 static void start(Thread* thread); 517 static void interrupt(Thread* thr); 518 static bool is_interrupted(Thread* thr, bool clear_interrupted); 519 520 void set_native_thread_name(const char *name) { 521 assert(Thread::current() == this, "set_native_thread_name can only be called on the current thread"); 522 os::set_native_thread_name(name); 523 } 524 525 ObjectMonitor** omInUseList_addr() { return (ObjectMonitor **)&omInUseList; } 526 Monitor* SR_lock() const { return _SR_lock; } 527 528 bool has_async_exception() const { return (_suspend_flags & _has_async_exception) != 0; } 529 530 inline void set_suspend_flag(SuspendFlags f); 531 inline void clear_suspend_flag(SuspendFlags f); 532 533 inline void set_has_async_exception(); 534 inline void clear_has_async_exception(); 535 536 bool do_critical_native_unlock() const { return (_suspend_flags & _critical_native_unlock) != 0; } 537 538 inline void set_critical_native_unlock(); 539 inline void clear_critical_native_unlock(); 540 541 inline void set_trace_flag(); 542 inline void clear_trace_flag(); 543 544 // Support for Unhandled Oop detection 545 // Add the field for both, fastdebug and debug, builds to keep 546 // Thread's fields layout the same. 547 // Note: CHECK_UNHANDLED_OOPS is defined only for fastdebug build. 548 #ifdef CHECK_UNHANDLED_OOPS 549 private: 550 UnhandledOops* _unhandled_oops; 551 #elif defined(ASSERT) 552 private: 553 void* _unhandled_oops; 554 #endif 555 #ifdef CHECK_UNHANDLED_OOPS 556 public: 557 UnhandledOops* unhandled_oops() { return _unhandled_oops; } 558 // Mark oop safe for gc. It may be stack allocated but won't move. 559 void allow_unhandled_oop(oop *op) { 560 if (CheckUnhandledOops) unhandled_oops()->allow_unhandled_oop(op); 561 } 562 // Clear oops at safepoint so crashes point to unhandled oop violator 563 void clear_unhandled_oops() { 564 if (CheckUnhandledOops) unhandled_oops()->clear_unhandled_oops(); 565 } 566 #endif // CHECK_UNHANDLED_OOPS 567 568 public: 569 #ifndef PRODUCT 570 bool skip_gcalot() { return _skip_gcalot; } 571 void set_skip_gcalot(bool v) { _skip_gcalot = v; } 572 #endif 573 574 // Installs a pending exception to be inserted later 575 static void send_async_exception(oop thread_oop, oop java_throwable); 576 577 // Resource area 578 ResourceArea* resource_area() const { return _resource_area; } 579 void set_resource_area(ResourceArea* area) { _resource_area = area; } 580 581 OSThread* osthread() const { return _osthread; } 582 void set_osthread(OSThread* thread) { _osthread = thread; } 583 584 // JNI handle support 585 JNIHandleBlock* active_handles() const { return _active_handles; } 586 void set_active_handles(JNIHandleBlock* block) { _active_handles = block; } 587 JNIHandleBlock* free_handle_block() const { return _free_handle_block; } 588 void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; } 589 590 // Internal handle support 591 HandleArea* handle_area() const { return _handle_area; } 592 void set_handle_area(HandleArea* area) { _handle_area = area; } 593 594 GrowableArray<Metadata*>* metadata_handles() const { return _metadata_handles; } 595 void set_metadata_handles(GrowableArray<Metadata*>* handles){ _metadata_handles = handles; } 596 597 // Thread-Local Allocation Buffer (TLAB) support 598 ThreadLocalAllocBuffer& tlab() { return _tlab; } 599 void initialize_tlab() { 600 if (UseTLAB) { 601 tlab().initialize(); 602 } 603 } 604 605 jlong allocated_bytes() { return _allocated_bytes; } 606 void set_allocated_bytes(jlong value) { _allocated_bytes = value; } 607 void incr_allocated_bytes(jlong size) { _allocated_bytes += size; } 608 inline jlong cooked_allocated_bytes(); 609 610 ThreadHeapSampler& heap_sampler() { return _heap_sampler; } 611 612 ThreadStatisticalInfo& statistical_info() { return _statistical_info; } 613 614 JFR_ONLY(DEFINE_THREAD_LOCAL_ACCESSOR_JFR;) 615 616 bool is_trace_suspend() { return (_suspend_flags & _trace_flag) != 0; } 617 618 // VM operation support 619 int vm_operation_ticket() { return ++_vm_operation_started_count; } 620 int vm_operation_completed_count() { return _vm_operation_completed_count; } 621 void increment_vm_operation_completed_count() { _vm_operation_completed_count++; } 622 623 // For tracking the heavyweight monitor the thread is pending on. 624 ObjectMonitor* current_pending_monitor() { 625 return _current_pending_monitor; 626 } 627 void set_current_pending_monitor(ObjectMonitor* monitor) { 628 _current_pending_monitor = monitor; 629 } 630 void set_current_pending_monitor_is_from_java(bool from_java) { 631 _current_pending_monitor_is_from_java = from_java; 632 } 633 bool current_pending_monitor_is_from_java() { 634 return _current_pending_monitor_is_from_java; 635 } 636 637 // For tracking the ObjectMonitor on which this thread called Object.wait() 638 ObjectMonitor* current_waiting_monitor() { 639 return _current_waiting_monitor; 640 } 641 void set_current_waiting_monitor(ObjectMonitor* monitor) { 642 _current_waiting_monitor = monitor; 643 } 644 645 // GC support 646 // Apply "f->do_oop" to all root oops in "this". 647 // Used by JavaThread::oops_do. 648 // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames 649 virtual void oops_do(OopClosure* f, CodeBlobClosure* cf); 650 651 // Handles the parallel case for claim_threads_do. 652 private: 653 bool claim_par_threads_do(uintx claim_token); 654 public: 655 // Requires that "claim_token" is that of the current iteration. 656 // If "is_par" is false, sets the token of "this" to 657 // "claim_token", and returns "true". If "is_par" is true, 658 // uses an atomic instruction to set the current thread's token to 659 // "claim_token", if it is not already. Returns "true" iff the 660 // calling thread does the update, this indicates that the calling thread 661 // has claimed the thread in the current iteration. 662 bool claim_threads_do(bool is_par, uintx claim_token) { 663 if (!is_par) { 664 _threads_do_token = claim_token; 665 return true; 666 } else { 667 return claim_par_threads_do(claim_token); 668 } 669 } 670 671 uintx threads_do_token() const { return _threads_do_token; } 672 673 // jvmtiRedefineClasses support 674 void metadata_handles_do(void f(Metadata*)); 675 676 // Used by fast lock support 677 virtual bool is_lock_owned(address adr) const; 678 679 // Check if address is in the stack of the thread (not just for locks). 680 // Warning: the method can only be used on the running thread 681 bool is_in_stack(address adr) const; 682 // Check if address is in the usable part of the stack (excludes protected 683 // guard pages) 684 bool is_in_usable_stack(address adr) const; 685 686 // Sets this thread as starting thread. Returns failure if thread 687 // creation fails due to lack of memory, too many threads etc. 688 bool set_as_starting_thread(); 689 690 protected: 691 // OS data associated with the thread 692 OSThread* _osthread; // Platform-specific thread information 693 694 // Thread local resource area for temporary allocation within the VM 695 ResourceArea* _resource_area; 696 697 DEBUG_ONLY(ResourceMark* _current_resource_mark;) 698 699 // Thread local handle area for allocation of handles within the VM 700 HandleArea* _handle_area; 701 GrowableArray<Metadata*>* _metadata_handles; 702 703 // Support for stack overflow handling, get_thread, etc. 704 address _stack_base; 705 size_t _stack_size; 706 uintptr_t _self_raw_id; // used by get_thread (mutable) 707 int _lgrp_id; 708 709 volatile void** polling_page_addr() { return &_polling_page; } 710 711 public: 712 // Stack overflow support 713 address stack_base() const { assert(_stack_base != NULL,"Sanity check"); return _stack_base; } 714 void set_stack_base(address base) { _stack_base = base; } 715 size_t stack_size() const { return _stack_size; } 716 void set_stack_size(size_t size) { _stack_size = size; } 717 address stack_end() const { return stack_base() - stack_size(); } 718 void record_stack_base_and_size(); 719 void register_thread_stack_with_NMT() NOT_NMT_RETURN; 720 721 bool on_local_stack(address adr) const { 722 // QQQ this has knowledge of direction, ought to be a stack method 723 return (_stack_base >= adr && adr >= stack_end()); 724 } 725 726 uintptr_t self_raw_id() { return _self_raw_id; } 727 void set_self_raw_id(uintptr_t value) { _self_raw_id = value; } 728 729 int lgrp_id() const { return _lgrp_id; } 730 void set_lgrp_id(int value) { _lgrp_id = value; } 731 732 // Printing 733 void print_on(outputStream* st, bool print_extended_info) const; 734 virtual void print_on(outputStream* st) const { print_on(st, false); } 735 void print() const { print_on(tty); } 736 virtual void print_on_error(outputStream* st, char* buf, int buflen) const; 737 void print_value_on(outputStream* st) const; 738 739 // Debug-only code 740 #ifdef ASSERT 741 private: 742 // Deadlock detection support for Mutex locks. List of locks own by thread. 743 Monitor* _owned_locks; 744 // Mutex::set_owner_implementation is the only place where _owned_locks is modified, 745 // thus the friendship 746 friend class Mutex; 747 friend class Monitor; 748 749 public: 750 void print_owned_locks_on(outputStream* st) const; 751 void print_owned_locks() const { print_owned_locks_on(tty); } 752 Monitor* owned_locks() const { return _owned_locks; } 753 bool owns_locks() const { return owned_locks() != NULL; } 754 bool owns_locks_but_compiled_lock() const; 755 756 // Deadlock detection 757 bool allow_allocation() { return _allow_allocation_count == 0; } 758 ResourceMark* current_resource_mark() { return _current_resource_mark; } 759 void set_current_resource_mark(ResourceMark* rm) { _current_resource_mark = rm; } 760 #endif 761 762 void check_for_valid_safepoint_state(bool potential_vm_operation) PRODUCT_RETURN; 763 764 private: 765 volatile int _jvmti_env_iteration_count; 766 767 public: 768 void entering_jvmti_env_iteration() { ++_jvmti_env_iteration_count; } 769 void leaving_jvmti_env_iteration() { --_jvmti_env_iteration_count; } 770 bool is_inside_jvmti_env_iteration() { return _jvmti_env_iteration_count > 0; } 771 772 // Code generation 773 static ByteSize exception_file_offset() { return byte_offset_of(Thread, _exception_file); } 774 static ByteSize exception_line_offset() { return byte_offset_of(Thread, _exception_line); } 775 static ByteSize active_handles_offset() { return byte_offset_of(Thread, _active_handles); } 776 777 static ByteSize stack_base_offset() { return byte_offset_of(Thread, _stack_base); } 778 static ByteSize stack_size_offset() { return byte_offset_of(Thread, _stack_size); } 779 780 static ByteSize polling_page_offset() { return byte_offset_of(Thread, _polling_page); } 781 782 static ByteSize tlab_start_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::start_offset(); } 783 static ByteSize tlab_end_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::end_offset(); } 784 static ByteSize tlab_top_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::top_offset(); } 785 static ByteSize tlab_pf_top_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::pf_top_offset(); } 786 787 static ByteSize allocated_bytes_offset() { return byte_offset_of(Thread, _allocated_bytes); } 788 789 JFR_ONLY(DEFINE_THREAD_LOCAL_OFFSET_JFR;) 790 791 public: 792 volatile intptr_t _Stalled; 793 volatile int _TypeTag; 794 ParkEvent * _ParkEvent; // for synchronized() 795 ParkEvent * _SleepEvent; // for Thread.sleep 796 ParkEvent * _MuxEvent; // for low-level muxAcquire-muxRelease 797 int NativeSyncRecursion; // diagnostic 798 799 volatile int _OnTrap; // Resume-at IP delta 800 jint _hashStateW; // Marsaglia Shift-XOR thread-local RNG 801 jint _hashStateX; // thread-specific hashCode generator state 802 jint _hashStateY; 803 jint _hashStateZ; 804 805 // Low-level leaf-lock primitives used to implement synchronization 806 // and native monitor-mutex infrastructure. 807 // Not for general synchronization use. 808 static void SpinAcquire(volatile int * Lock, const char * Name); 809 static void SpinRelease(volatile int * Lock); 810 static void muxAcquire(volatile intptr_t * Lock, const char * Name); 811 static void muxAcquireW(volatile intptr_t * Lock, ParkEvent * ev); 812 static void muxRelease(volatile intptr_t * Lock); 813 }; 814 815 // Inline implementation of Thread::current() 816 inline Thread* Thread::current() { 817 Thread* current = current_or_null(); 818 assert(current != NULL, "Thread::current() called on detached thread"); 819 return current; 820 } 821 822 inline Thread* Thread::current_or_null() { 823 #ifndef USE_LIBRARY_BASED_TLS_ONLY 824 return _thr_current; 825 #else 826 if (ThreadLocalStorage::is_initialized()) { 827 return ThreadLocalStorage::thread(); 828 } 829 return NULL; 830 #endif 831 } 832 833 inline Thread* Thread::current_or_null_safe() { 834 if (ThreadLocalStorage::is_initialized()) { 835 return ThreadLocalStorage::thread(); 836 } 837 return NULL; 838 } 839 840 class NonJavaThread: public Thread { 841 friend class VMStructs; 842 843 NonJavaThread* volatile _next; 844 845 class List; 846 static List _the_list; 847 848 void add_to_the_list(); 849 void remove_from_the_list(); 850 851 protected: 852 virtual void pre_run(); 853 virtual void post_run(); 854 855 public: 856 NonJavaThread(); 857 ~NonJavaThread(); 858 859 class Iterator; 860 }; 861 862 // Provides iteration over the list of NonJavaThreads. 863 // List addition occurs in pre_run(), and removal occurs in post_run(), 864 // so that only live fully-initialized threads can be found in the list. 865 // Threads created after an iterator is constructed will not be visited 866 // by the iterator. The scope of an iterator is a critical section; there 867 // must be no safepoint checks in that scope. 868 class NonJavaThread::Iterator : public StackObj { 869 uint _protect_enter; 870 NonJavaThread* _current; 871 872 // Noncopyable. 873 Iterator(const Iterator&); 874 Iterator& operator=(const Iterator&); 875 876 public: 877 Iterator(); 878 ~Iterator(); 879 880 bool end() const { return _current == NULL; } 881 NonJavaThread* current() const { return _current; } 882 void step(); 883 }; 884 885 // Name support for threads. non-JavaThread subclasses with multiple 886 // uniquely named instances should derive from this. 887 class NamedThread: public NonJavaThread { 888 friend class VMStructs; 889 enum { 890 max_name_len = 64 891 }; 892 private: 893 char* _name; 894 // log JavaThread being processed by oops_do 895 JavaThread* _processed_thread; 896 uint _gc_id; // The current GC id when a thread takes part in GC 897 898 public: 899 NamedThread(); 900 ~NamedThread(); 901 // May only be called once per thread. 902 void set_name(const char* format, ...) ATTRIBUTE_PRINTF(2, 3); 903 virtual bool is_Named_thread() const { return true; } 904 virtual char* name() const { return _name == NULL ? (char*)"Unknown Thread" : _name; } 905 JavaThread *processed_thread() { return _processed_thread; } 906 void set_processed_thread(JavaThread *thread) { _processed_thread = thread; } 907 virtual void print_on(outputStream* st) const; 908 909 void set_gc_id(uint gc_id) { _gc_id = gc_id; } 910 uint gc_id() { return _gc_id; } 911 }; 912 913 // Worker threads are named and have an id of an assigned work. 914 class WorkerThread: public NamedThread { 915 private: 916 uint _id; 917 public: 918 WorkerThread() : _id(0) { } 919 virtual bool is_Worker_thread() const { return true; } 920 921 virtual WorkerThread* as_Worker_thread() const { 922 assert(is_Worker_thread(), "Dubious cast to WorkerThread*?"); 923 return (WorkerThread*) this; 924 } 925 926 void set_id(uint work_id) { _id = work_id; } 927 uint id() const { return _id; } 928 }; 929 930 // A single WatcherThread is used for simulating timer interrupts. 931 class WatcherThread: public NonJavaThread { 932 friend class VMStructs; 933 protected: 934 virtual void run(); 935 936 private: 937 static WatcherThread* _watcher_thread; 938 939 static bool _startable; 940 // volatile due to at least one lock-free read 941 volatile static bool _should_terminate; 942 public: 943 enum SomeConstants { 944 delay_interval = 10 // interrupt delay in milliseconds 945 }; 946 947 // Constructor 948 WatcherThread(); 949 950 // No destruction allowed 951 ~WatcherThread() { 952 guarantee(false, "WatcherThread deletion must fix the race with VM termination"); 953 } 954 955 // Tester 956 bool is_Watcher_thread() const { return true; } 957 958 // Printing 959 char* name() const { return (char*)"VM Periodic Task Thread"; } 960 void print_on(outputStream* st) const; 961 void unpark(); 962 963 // Returns the single instance of WatcherThread 964 static WatcherThread* watcher_thread() { return _watcher_thread; } 965 966 // Create and start the single instance of WatcherThread, or stop it on shutdown 967 static void start(); 968 static void stop(); 969 // Only allow start once the VM is sufficiently initialized 970 // Otherwise the first task to enroll will trigger the start 971 static void make_startable(); 972 private: 973 int sleep() const; 974 }; 975 976 977 class CompilerThread; 978 979 typedef void (*ThreadFunction)(JavaThread*, TRAPS); 980 981 class JavaThread: public Thread { 982 friend class VMStructs; 983 friend class JVMCIVMStructs; 984 friend class WhiteBox; 985 private: 986 JavaThread* _next; // The next thread in the Threads list 987 bool _on_thread_list; // Is set when this JavaThread is added to the Threads list 988 oop _threadObj; // The Java level thread object 989 990 #ifdef ASSERT 991 private: 992 int _java_call_counter; 993 994 public: 995 int java_call_counter() { return _java_call_counter; } 996 void inc_java_call_counter() { _java_call_counter++; } 997 void dec_java_call_counter() { 998 assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper"); 999 _java_call_counter--; 1000 } 1001 private: // restore original namespace restriction 1002 #endif // ifdef ASSERT 1003 1004 #ifndef PRODUCT 1005 public: 1006 enum { 1007 jump_ring_buffer_size = 16 1008 }; 1009 private: // restore original namespace restriction 1010 #endif 1011 1012 JavaFrameAnchor _anchor; // Encapsulation of current java frame and it state 1013 1014 ThreadFunction _entry_point; 1015 1016 JNIEnv _jni_environment; 1017 1018 // Deopt support 1019 DeoptResourceMark* _deopt_mark; // Holds special ResourceMark for deoptimization 1020 1021 intptr_t* _must_deopt_id; // id of frame that needs to be deopted once we 1022 // transition out of native 1023 CompiledMethod* _deopt_nmethod; // CompiledMethod that is currently being deoptimized 1024 vframeArray* _vframe_array_head; // Holds the heap of the active vframeArrays 1025 vframeArray* _vframe_array_last; // Holds last vFrameArray we popped 1026 // Because deoptimization is lazy we must save jvmti requests to set locals 1027 // in compiled frames until we deoptimize and we have an interpreter frame. 1028 // This holds the pointer to array (yeah like there might be more than one) of 1029 // description of compiled vframes that have locals that need to be updated. 1030 GrowableArray<jvmtiDeferredLocalVariableSet*>* _deferred_locals_updates; 1031 1032 // Handshake value for fixing 6243940. We need a place for the i2c 1033 // adapter to store the callee Method*. This value is NEVER live 1034 // across a gc point so it does NOT have to be gc'd 1035 // The handshake is open ended since we can't be certain that it will 1036 // be NULLed. This is because we rarely ever see the race and end up 1037 // in handle_wrong_method which is the backend of the handshake. See 1038 // code in i2c adapters and handle_wrong_method. 1039 1040 Method* _callee_target; 1041 1042 // Used to pass back results to the interpreter or generated code running Java code. 1043 oop _vm_result; // oop result is GC-preserved 1044 Metadata* _vm_result_2; // non-oop result 1045 1046 // See ReduceInitialCardMarks: this holds the precise space interval of 1047 // the most recent slow path allocation for which compiled code has 1048 // elided card-marks for performance along the fast-path. 1049 MemRegion _deferred_card_mark; 1050 1051 MonitorChunk* _monitor_chunks; // Contains the off stack monitors 1052 // allocated during deoptimization 1053 // and by JNI_MonitorEnter/Exit 1054 1055 // Async. requests support 1056 enum AsyncRequests { 1057 _no_async_condition = 0, 1058 _async_exception, 1059 _async_unsafe_access_error 1060 }; 1061 AsyncRequests _special_runtime_exit_condition; // Enum indicating pending async. request 1062 oop _pending_async_exception; 1063 1064 // Safepoint support 1065 public: // Expose _thread_state for SafeFetchInt() 1066 volatile JavaThreadState _thread_state; 1067 private: 1068 ThreadSafepointState* _safepoint_state; // Holds information about a thread during a safepoint 1069 address _saved_exception_pc; // Saved pc of instruction where last implicit exception happened 1070 1071 // JavaThread termination support 1072 enum TerminatedTypes { 1073 _not_terminated = 0xDEAD - 2, 1074 _thread_exiting, // JavaThread::exit() has been called for this thread 1075 _thread_terminated, // JavaThread is removed from thread list 1076 _vm_exited // JavaThread is still executing native code, but VM is terminated 1077 // only VM_Exit can set _vm_exited 1078 }; 1079 1080 // In general a JavaThread's _terminated field transitions as follows: 1081 // 1082 // _not_terminated => _thread_exiting => _thread_terminated 1083 // 1084 // _vm_exited is a special value to cover the case of a JavaThread 1085 // executing native code after the VM itself is terminated. 1086 volatile TerminatedTypes _terminated; 1087 // suspend/resume support 1088 volatile bool _suspend_equivalent; // Suspend equivalent condition 1089 jint _in_deopt_handler; // count of deoptimization 1090 // handlers thread is in 1091 volatile bool _doing_unsafe_access; // Thread may fault due to unsafe access 1092 bool _do_not_unlock_if_synchronized; // Do not unlock the receiver of a synchronized method (since it was 1093 // never locked) when throwing an exception. Used by interpreter only. 1094 1095 // JNI attach states: 1096 enum JNIAttachStates { 1097 _not_attaching_via_jni = 1, // thread is not attaching via JNI 1098 _attaching_via_jni, // thread is attaching via JNI 1099 _attached_via_jni // thread has attached via JNI 1100 }; 1101 1102 // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni. 1103 // A native thread that is attaching via JNI starts with a value 1104 // of _attaching_via_jni and transitions to _attached_via_jni. 1105 volatile JNIAttachStates _jni_attach_state; 1106 1107 public: 1108 // State of the stack guard pages for this thread. 1109 enum StackGuardState { 1110 stack_guard_unused, // not needed 1111 stack_guard_reserved_disabled, 1112 stack_guard_yellow_reserved_disabled,// disabled (temporarily) after stack overflow 1113 stack_guard_enabled // enabled 1114 }; 1115 1116 private: 1117 1118 #if INCLUDE_JVMCI 1119 // The _pending_* fields below are used to communicate extra information 1120 // from an uncommon trap in JVMCI compiled code to the uncommon trap handler. 1121 1122 // Communicates the DeoptReason and DeoptAction of the uncommon trap 1123 int _pending_deoptimization; 1124 1125 // Specifies whether the uncommon trap is to bci 0 of a synchronized method 1126 // before the monitor has been acquired. 1127 bool _pending_monitorenter; 1128 1129 // Specifies if the DeoptReason for the last uncommon trap was Reason_transfer_to_interpreter 1130 bool _pending_transfer_to_interpreter; 1131 1132 // True if in a runtime call from compiled code that will deoptimize 1133 // and re-execute a failed heap allocation in the interpreter. 1134 bool _in_retryable_allocation; 1135 1136 // An id of a speculation that JVMCI compiled code can use to further describe and 1137 // uniquely identify the speculative optimization guarded by the uncommon trap 1138 jlong _pending_failed_speculation; 1139 1140 // These fields are mutually exclusive in terms of live ranges. 1141 union { 1142 // Communicates the pc at which the most recent implicit exception occurred 1143 // from the signal handler to a deoptimization stub. 1144 address _implicit_exception_pc; 1145 1146 // Communicates an alternative call target to an i2c stub from a JavaCall . 1147 address _alternate_call_target; 1148 } _jvmci; 1149 1150 // Support for high precision, thread sensitive counters in JVMCI compiled code. 1151 jlong* _jvmci_counters; 1152 1153 public: 1154 static jlong* _jvmci_old_thread_counters; 1155 static void collect_counters(JVMCIEnv* JVMCIENV, JVMCIPrimitiveArray array); 1156 private: 1157 #endif // INCLUDE_JVMCI 1158 1159 StackGuardState _stack_guard_state; 1160 1161 // Precompute the limit of the stack as used in stack overflow checks. 1162 // We load it from here to simplify the stack overflow check in assembly. 1163 address _stack_overflow_limit; 1164 address _reserved_stack_activation; 1165 1166 // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is 1167 // used to temp. parsing values into and out of the runtime system during exception handling for compiled 1168 // code) 1169 volatile oop _exception_oop; // Exception thrown in compiled code 1170 volatile address _exception_pc; // PC where exception happened 1171 volatile address _exception_handler_pc; // PC for handler of exception 1172 volatile int _is_method_handle_return; // true (== 1) if the current exception PC is a MethodHandle call site. 1173 1174 private: 1175 // support for JNI critical regions 1176 jint _jni_active_critical; // count of entries into JNI critical region 1177 1178 // Checked JNI: function name requires exception check 1179 char* _pending_jni_exception_check_fn; 1180 1181 // For deadlock detection. 1182 int _depth_first_number; 1183 1184 // JVMTI PopFrame support 1185 // This is set to popframe_pending to signal that top Java frame should be popped immediately 1186 int _popframe_condition; 1187 1188 // If reallocation of scalar replaced objects fails, we throw OOM 1189 // and during exception propagation, pop the top 1190 // _frames_to_pop_failed_realloc frames, the ones that reference 1191 // failed reallocations. 1192 int _frames_to_pop_failed_realloc; 1193 1194 #ifndef PRODUCT 1195 int _jmp_ring_index; 1196 struct { 1197 // We use intptr_t instead of address so debugger doesn't try and display strings 1198 intptr_t _target; 1199 intptr_t _instruction; 1200 const char* _file; 1201 int _line; 1202 } _jmp_ring[jump_ring_buffer_size]; 1203 #endif // PRODUCT 1204 1205 friend class VMThread; 1206 friend class ThreadWaitTransition; 1207 friend class VM_Exit; 1208 1209 void initialize(); // Initialized the instance variables 1210 1211 public: 1212 // Constructor 1213 JavaThread(bool is_attaching_via_jni = false); // for main thread and JNI attached threads 1214 JavaThread(ThreadFunction entry_point, size_t stack_size = 0); 1215 ~JavaThread(); 1216 1217 #ifdef ASSERT 1218 // verify this JavaThread hasn't be published in the Threads::list yet 1219 void verify_not_published(); 1220 #endif 1221 1222 //JNI functiontable getter/setter for JVMTI jni function table interception API. 1223 void set_jni_functions(struct JNINativeInterface_* functionTable) { 1224 _jni_environment.functions = functionTable; 1225 } 1226 struct JNINativeInterface_* get_jni_functions() { 1227 return (struct JNINativeInterface_ *)_jni_environment.functions; 1228 } 1229 1230 // This function is called at thread creation to allow 1231 // platform specific thread variables to be initialized. 1232 void cache_global_variables(); 1233 1234 // Executes Shutdown.shutdown() 1235 void invoke_shutdown_hooks(); 1236 1237 // Cleanup on thread exit 1238 enum ExitType { 1239 normal_exit, 1240 jni_detach 1241 }; 1242 void exit(bool destroy_vm, ExitType exit_type = normal_exit); 1243 1244 void cleanup_failed_attach_current_thread(bool is_daemon); 1245 1246 // Testers 1247 virtual bool is_Java_thread() const { return true; } 1248 virtual bool can_call_java() const { return true; } 1249 1250 // Thread chain operations 1251 JavaThread* next() const { return _next; } 1252 void set_next(JavaThread* p) { _next = p; } 1253 1254 // Thread oop. threadObj() can be NULL for initial JavaThread 1255 // (or for threads attached via JNI) 1256 oop threadObj() const { return _threadObj; } 1257 void set_threadObj(oop p) { _threadObj = p; } 1258 1259 ThreadPriority java_priority() const; // Read from threadObj() 1260 1261 // Prepare thread and add to priority queue. If a priority is 1262 // not specified, use the priority of the thread object. Threads_lock 1263 // must be held while this function is called. 1264 void prepare(jobject jni_thread, ThreadPriority prio=NoPriority); 1265 1266 void set_saved_exception_pc(address pc) { _saved_exception_pc = pc; } 1267 address saved_exception_pc() { return _saved_exception_pc; } 1268 1269 1270 ThreadFunction entry_point() const { return _entry_point; } 1271 1272 // Allocates a new Java level thread object for this thread. thread_name may be NULL. 1273 void allocate_threadObj(Handle thread_group, const char* thread_name, bool daemon, TRAPS); 1274 1275 // Last frame anchor routines 1276 1277 JavaFrameAnchor* frame_anchor(void) { return &_anchor; } 1278 1279 // last_Java_sp 1280 bool has_last_Java_frame() const { return _anchor.has_last_Java_frame(); } 1281 intptr_t* last_Java_sp() const { return _anchor.last_Java_sp(); } 1282 1283 // last_Java_pc 1284 1285 address last_Java_pc(void) { return _anchor.last_Java_pc(); } 1286 1287 // Safepoint support 1288 inline JavaThreadState thread_state() const; 1289 inline void set_thread_state(JavaThreadState s); 1290 inline void set_thread_state_fence(JavaThreadState s); // fence after setting thread state 1291 inline ThreadSafepointState* safepoint_state() const; 1292 inline void set_safepoint_state(ThreadSafepointState* state); 1293 inline bool is_at_poll_safepoint(); 1294 1295 // JavaThread termination and lifecycle support: 1296 void smr_delete(); 1297 bool on_thread_list() const { return _on_thread_list; } 1298 void set_on_thread_list() { _on_thread_list = true; } 1299 1300 // thread has called JavaThread::exit() or is terminated 1301 bool is_exiting() const; 1302 // thread is terminated (no longer on the threads list); we compare 1303 // against the two non-terminated values so that a freed JavaThread 1304 // will also be considered terminated. 1305 bool check_is_terminated(TerminatedTypes l_terminated) const { 1306 return l_terminated != _not_terminated && l_terminated != _thread_exiting; 1307 } 1308 bool is_terminated() const; 1309 void set_terminated(TerminatedTypes t); 1310 // special for Threads::remove() which is static: 1311 void set_terminated_value(); 1312 void block_if_vm_exited(); 1313 1314 bool doing_unsafe_access() { return _doing_unsafe_access; } 1315 void set_doing_unsafe_access(bool val) { _doing_unsafe_access = val; } 1316 1317 bool do_not_unlock_if_synchronized() { return _do_not_unlock_if_synchronized; } 1318 void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; } 1319 1320 inline void set_polling_page_release(void* poll_value); 1321 inline void set_polling_page(void* poll_value); 1322 inline volatile void* get_polling_page(); 1323 1324 private: 1325 // Support for thread handshake operations 1326 HandshakeState _handshake; 1327 public: 1328 void set_handshake_operation(HandshakeOperation* op) { 1329 _handshake.set_operation(this, op); 1330 } 1331 1332 bool has_handshake() const { 1333 return _handshake.has_operation(); 1334 } 1335 1336 void handshake_process_by_self() { 1337 _handshake.process_by_self(this); 1338 } 1339 1340 void handshake_process_by_vmthread() { 1341 _handshake.process_by_vmthread(this); 1342 } 1343 1344 // Suspend/resume support for JavaThread 1345 private: 1346 inline void set_ext_suspended(); 1347 inline void clear_ext_suspended(); 1348 1349 public: 1350 void java_suspend(); // higher-level suspension logic called by the public APIs 1351 void java_resume(); // higher-level resume logic called by the public APIs 1352 int java_suspend_self(); // low-level self-suspension mechanics 1353 1354 private: 1355 // mid-level wrapper around java_suspend_self to set up correct state and 1356 // check for a pending safepoint at the end 1357 void java_suspend_self_with_safepoint_check(); 1358 1359 public: 1360 void check_and_wait_while_suspended() { 1361 assert(JavaThread::current() == this, "sanity check"); 1362 1363 bool do_self_suspend; 1364 do { 1365 // were we externally suspended while we were waiting? 1366 do_self_suspend = handle_special_suspend_equivalent_condition(); 1367 if (do_self_suspend) { 1368 // don't surprise the thread that suspended us by returning 1369 java_suspend_self(); 1370 set_suspend_equivalent(); 1371 } 1372 } while (do_self_suspend); 1373 } 1374 static void check_safepoint_and_suspend_for_native_trans(JavaThread *thread); 1375 // Check for async exception in addition to safepoint and suspend request. 1376 static void check_special_condition_for_native_trans(JavaThread *thread); 1377 1378 // Same as check_special_condition_for_native_trans but finishes the 1379 // transition into thread_in_Java mode so that it can potentially 1380 // block. 1381 static void check_special_condition_for_native_trans_and_transition(JavaThread *thread); 1382 1383 bool is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits); 1384 bool is_ext_suspend_completed_with_lock(uint32_t *bits) { 1385 MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag); 1386 // Warning: is_ext_suspend_completed() may temporarily drop the 1387 // SR_lock to allow the thread to reach a stable thread state if 1388 // it is currently in a transient thread state. 1389 return is_ext_suspend_completed(false /* !called_by_wait */, 1390 SuspendRetryDelay, bits); 1391 } 1392 1393 // We cannot allow wait_for_ext_suspend_completion() to run forever or 1394 // we could hang. SuspendRetryCount and SuspendRetryDelay are normally 1395 // passed as the count and delay parameters. Experiments with specific 1396 // calls to wait_for_ext_suspend_completion() can be done by passing 1397 // other values in the code. Experiments with all calls can be done 1398 // via the appropriate -XX options. 1399 bool wait_for_ext_suspend_completion(int count, int delay, uint32_t *bits); 1400 1401 // test for suspend - most (all?) of these should go away 1402 bool is_thread_fully_suspended(bool wait_for_suspend, uint32_t *bits); 1403 1404 inline void set_external_suspend(); 1405 inline void clear_external_suspend(); 1406 1407 bool is_external_suspend() const { 1408 return (_suspend_flags & _external_suspend) != 0; 1409 } 1410 // Whenever a thread transitions from native to vm/java it must suspend 1411 // if external|deopt suspend is present. 1412 bool is_suspend_after_native() const { 1413 return (_suspend_flags & (_external_suspend JFR_ONLY(| _trace_flag))) != 0; 1414 } 1415 1416 // external suspend request is completed 1417 bool is_ext_suspended() const { 1418 return (_suspend_flags & _ext_suspended) != 0; 1419 } 1420 1421 bool is_external_suspend_with_lock() const { 1422 MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag); 1423 return is_external_suspend(); 1424 } 1425 1426 // Special method to handle a pending external suspend request 1427 // when a suspend equivalent condition lifts. 1428 bool handle_special_suspend_equivalent_condition() { 1429 assert(is_suspend_equivalent(), 1430 "should only be called in a suspend equivalence condition"); 1431 MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag); 1432 bool ret = is_external_suspend(); 1433 if (!ret) { 1434 // not about to self-suspend so clear suspend equivalence 1435 clear_suspend_equivalent(); 1436 } 1437 // implied else: 1438 // We have a pending external suspend request so we leave the 1439 // suspend_equivalent flag set until java_suspend_self() sets 1440 // the ext_suspended flag and clears the suspend_equivalent 1441 // flag. This insures that wait_for_ext_suspend_completion() 1442 // will return consistent values. 1443 return ret; 1444 } 1445 1446 // utility methods to see if we are doing some kind of suspension 1447 bool is_being_ext_suspended() const { 1448 MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag); 1449 return is_ext_suspended() || is_external_suspend(); 1450 } 1451 1452 bool is_suspend_equivalent() const { return _suspend_equivalent; } 1453 1454 void set_suspend_equivalent() { _suspend_equivalent = true; } 1455 void clear_suspend_equivalent() { _suspend_equivalent = false; } 1456 1457 // Thread.stop support 1458 void send_thread_stop(oop throwable); 1459 AsyncRequests clear_special_runtime_exit_condition() { 1460 AsyncRequests x = _special_runtime_exit_condition; 1461 _special_runtime_exit_condition = _no_async_condition; 1462 return x; 1463 } 1464 1465 // Are any async conditions present? 1466 bool has_async_condition() { return (_special_runtime_exit_condition != _no_async_condition); } 1467 1468 void check_and_handle_async_exceptions(bool check_unsafe_error = true); 1469 1470 // these next two are also used for self-suspension and async exception support 1471 void handle_special_runtime_exit_condition(bool check_asyncs = true); 1472 1473 // Return true if JavaThread has an asynchronous condition or 1474 // if external suspension is requested. 1475 bool has_special_runtime_exit_condition() { 1476 // Because we don't use is_external_suspend_with_lock 1477 // it is possible that we won't see an asynchronous external suspend 1478 // request that has just gotten started, i.e., SR_lock grabbed but 1479 // _external_suspend field change either not made yet or not visible 1480 // yet. However, this is okay because the request is asynchronous and 1481 // we will see the new flag value the next time through. It's also 1482 // possible that the external suspend request is dropped after 1483 // we have checked is_external_suspend(), we will recheck its value 1484 // under SR_lock in java_suspend_self(). 1485 return (_special_runtime_exit_condition != _no_async_condition) || 1486 is_external_suspend() || is_trace_suspend(); 1487 } 1488 1489 void set_pending_unsafe_access_error() { _special_runtime_exit_condition = _async_unsafe_access_error; } 1490 1491 inline void set_pending_async_exception(oop e); 1492 1493 // Fast-locking support 1494 bool is_lock_owned(address adr) const; 1495 1496 // Accessors for vframe array top 1497 // The linked list of vframe arrays are sorted on sp. This means when we 1498 // unpack the head must contain the vframe array to unpack. 1499 void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; } 1500 vframeArray* vframe_array_head() const { return _vframe_array_head; } 1501 1502 // Side structure for deferring update of java frame locals until deopt occurs 1503 GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred_locals() const { return _deferred_locals_updates; } 1504 void set_deferred_locals(GrowableArray<jvmtiDeferredLocalVariableSet *>* vf) { _deferred_locals_updates = vf; } 1505 1506 // These only really exist to make debugging deopt problems simpler 1507 1508 void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; } 1509 vframeArray* vframe_array_last() const { return _vframe_array_last; } 1510 1511 // The special resourceMark used during deoptimization 1512 1513 void set_deopt_mark(DeoptResourceMark* value) { _deopt_mark = value; } 1514 DeoptResourceMark* deopt_mark(void) { return _deopt_mark; } 1515 1516 intptr_t* must_deopt_id() { return _must_deopt_id; } 1517 void set_must_deopt_id(intptr_t* id) { _must_deopt_id = id; } 1518 void clear_must_deopt_id() { _must_deopt_id = NULL; } 1519 1520 void set_deopt_compiled_method(CompiledMethod* nm) { _deopt_nmethod = nm; } 1521 CompiledMethod* deopt_compiled_method() { return _deopt_nmethod; } 1522 1523 Method* callee_target() const { return _callee_target; } 1524 void set_callee_target (Method* x) { _callee_target = x; } 1525 1526 // Oop results of vm runtime calls 1527 oop vm_result() const { return _vm_result; } 1528 void set_vm_result (oop x) { _vm_result = x; } 1529 1530 Metadata* vm_result_2() const { return _vm_result_2; } 1531 void set_vm_result_2 (Metadata* x) { _vm_result_2 = x; } 1532 1533 MemRegion deferred_card_mark() const { return _deferred_card_mark; } 1534 void set_deferred_card_mark(MemRegion mr) { _deferred_card_mark = mr; } 1535 1536 #if INCLUDE_JVMCI 1537 int pending_deoptimization() const { return _pending_deoptimization; } 1538 jlong pending_failed_speculation() const { return _pending_failed_speculation; } 1539 bool has_pending_monitorenter() const { return _pending_monitorenter; } 1540 void set_pending_monitorenter(bool b) { _pending_monitorenter = b; } 1541 void set_pending_deoptimization(int reason) { _pending_deoptimization = reason; } 1542 void set_pending_failed_speculation(jlong failed_speculation) { _pending_failed_speculation = failed_speculation; } 1543 void set_pending_transfer_to_interpreter(bool b) { _pending_transfer_to_interpreter = b; } 1544 void set_jvmci_alternate_call_target(address a) { assert(_jvmci._alternate_call_target == NULL, "must be"); _jvmci._alternate_call_target = a; } 1545 void set_jvmci_implicit_exception_pc(address a) { assert(_jvmci._implicit_exception_pc == NULL, "must be"); _jvmci._implicit_exception_pc = a; } 1546 1547 virtual bool in_retryable_allocation() const { return _in_retryable_allocation; } 1548 void set_in_retryable_allocation(bool b) { _in_retryable_allocation = b; } 1549 #endif // INCLUDE_JVMCI 1550 1551 // Exception handling for compiled methods 1552 oop exception_oop() const { return _exception_oop; } 1553 address exception_pc() const { return _exception_pc; } 1554 address exception_handler_pc() const { return _exception_handler_pc; } 1555 bool is_method_handle_return() const { return _is_method_handle_return == 1; } 1556 1557 void set_exception_oop(oop o) { (void)const_cast<oop&>(_exception_oop = o); } 1558 void set_exception_pc(address a) { _exception_pc = a; } 1559 void set_exception_handler_pc(address a) { _exception_handler_pc = a; } 1560 void set_is_method_handle_return(bool value) { _is_method_handle_return = value ? 1 : 0; } 1561 1562 void clear_exception_oop_and_pc() { 1563 set_exception_oop(NULL); 1564 set_exception_pc(NULL); 1565 } 1566 1567 // Stack overflow support 1568 // 1569 // (small addresses) 1570 // 1571 // -- <-- stack_end() --- 1572 // | | 1573 // | red pages | 1574 // | | 1575 // -- <-- stack_red_zone_base() | 1576 // | | 1577 // | guard 1578 // | yellow pages zone 1579 // | | 1580 // | | 1581 // -- <-- stack_yellow_zone_base() | 1582 // | | 1583 // | | 1584 // | reserved pages | 1585 // | | 1586 // -- <-- stack_reserved_zone_base() --- --- 1587 // /|\ shadow <-- stack_overflow_limit() (somewhere in here) 1588 // | zone 1589 // \|/ size 1590 // some untouched memory --- 1591 // 1592 // 1593 // -- 1594 // | 1595 // | shadow zone 1596 // | 1597 // -- 1598 // x frame n 1599 // -- 1600 // x frame n-1 1601 // x 1602 // -- 1603 // ... 1604 // 1605 // -- 1606 // x frame 0 1607 // -- <-- stack_base() 1608 // 1609 // (large addresses) 1610 // 1611 1612 private: 1613 // These values are derived from flags StackRedPages, StackYellowPages, 1614 // StackReservedPages and StackShadowPages. The zone size is determined 1615 // ergonomically if page_size > 4K. 1616 static size_t _stack_red_zone_size; 1617 static size_t _stack_yellow_zone_size; 1618 static size_t _stack_reserved_zone_size; 1619 static size_t _stack_shadow_zone_size; 1620 public: 1621 inline size_t stack_available(address cur_sp); 1622 1623 static size_t stack_red_zone_size() { 1624 assert(_stack_red_zone_size > 0, "Don't call this before the field is initialized."); 1625 return _stack_red_zone_size; 1626 } 1627 static void set_stack_red_zone_size(size_t s) { 1628 assert(is_aligned(s, os::vm_page_size()), 1629 "We can not protect if the red zone size is not page aligned."); 1630 assert(_stack_red_zone_size == 0, "This should be called only once."); 1631 _stack_red_zone_size = s; 1632 } 1633 address stack_red_zone_base() { 1634 return (address)(stack_end() + stack_red_zone_size()); 1635 } 1636 bool in_stack_red_zone(address a) { 1637 return a <= stack_red_zone_base() && a >= stack_end(); 1638 } 1639 1640 static size_t stack_yellow_zone_size() { 1641 assert(_stack_yellow_zone_size > 0, "Don't call this before the field is initialized."); 1642 return _stack_yellow_zone_size; 1643 } 1644 static void set_stack_yellow_zone_size(size_t s) { 1645 assert(is_aligned(s, os::vm_page_size()), 1646 "We can not protect if the yellow zone size is not page aligned."); 1647 assert(_stack_yellow_zone_size == 0, "This should be called only once."); 1648 _stack_yellow_zone_size = s; 1649 } 1650 1651 static size_t stack_reserved_zone_size() { 1652 // _stack_reserved_zone_size may be 0. This indicates the feature is off. 1653 return _stack_reserved_zone_size; 1654 } 1655 static void set_stack_reserved_zone_size(size_t s) { 1656 assert(is_aligned(s, os::vm_page_size()), 1657 "We can not protect if the reserved zone size is not page aligned."); 1658 assert(_stack_reserved_zone_size == 0, "This should be called only once."); 1659 _stack_reserved_zone_size = s; 1660 } 1661 address stack_reserved_zone_base() { 1662 return (address)(stack_end() + 1663 (stack_red_zone_size() + stack_yellow_zone_size() + stack_reserved_zone_size())); 1664 } 1665 bool in_stack_reserved_zone(address a) { 1666 return (a <= stack_reserved_zone_base()) && 1667 (a >= (address)((intptr_t)stack_reserved_zone_base() - stack_reserved_zone_size())); 1668 } 1669 1670 static size_t stack_yellow_reserved_zone_size() { 1671 return _stack_yellow_zone_size + _stack_reserved_zone_size; 1672 } 1673 bool in_stack_yellow_reserved_zone(address a) { 1674 return (a <= stack_reserved_zone_base()) && (a >= stack_red_zone_base()); 1675 } 1676 1677 // Size of red + yellow + reserved zones. 1678 static size_t stack_guard_zone_size() { 1679 return stack_red_zone_size() + stack_yellow_reserved_zone_size(); 1680 } 1681 1682 static size_t stack_shadow_zone_size() { 1683 assert(_stack_shadow_zone_size > 0, "Don't call this before the field is initialized."); 1684 return _stack_shadow_zone_size; 1685 } 1686 static void set_stack_shadow_zone_size(size_t s) { 1687 // The shadow area is not allocated or protected, so 1688 // it needs not be page aligned. 1689 // But the stack bang currently assumes that it is a 1690 // multiple of page size. This guarantees that the bang 1691 // loop touches all pages in the shadow zone. 1692 // This can be guaranteed differently, as well. E.g., if 1693 // the page size is a multiple of 4K, banging in 4K steps 1694 // suffices to touch all pages. (Some pages are banged 1695 // several times, though.) 1696 assert(is_aligned(s, os::vm_page_size()), 1697 "Stack bang assumes multiple of page size."); 1698 assert(_stack_shadow_zone_size == 0, "This should be called only once."); 1699 _stack_shadow_zone_size = s; 1700 } 1701 1702 void create_stack_guard_pages(); 1703 void remove_stack_guard_pages(); 1704 1705 void enable_stack_reserved_zone(); 1706 void disable_stack_reserved_zone(); 1707 void enable_stack_yellow_reserved_zone(); 1708 void disable_stack_yellow_reserved_zone(); 1709 void enable_stack_red_zone(); 1710 void disable_stack_red_zone(); 1711 1712 inline bool stack_guard_zone_unused(); 1713 inline bool stack_yellow_reserved_zone_disabled(); 1714 inline bool stack_reserved_zone_disabled(); 1715 inline bool stack_guards_enabled(); 1716 1717 address reserved_stack_activation() const { return _reserved_stack_activation; } 1718 void set_reserved_stack_activation(address addr) { 1719 assert(_reserved_stack_activation == stack_base() 1720 || _reserved_stack_activation == NULL 1721 || addr == stack_base(), "Must not be set twice"); 1722 _reserved_stack_activation = addr; 1723 } 1724 1725 // Attempt to reguard the stack after a stack overflow may have occurred. 1726 // Returns true if (a) guard pages are not needed on this thread, (b) the 1727 // pages are already guarded, or (c) the pages were successfully reguarded. 1728 // Returns false if there is not enough stack space to reguard the pages, in 1729 // which case the caller should unwind a frame and try again. The argument 1730 // should be the caller's (approximate) sp. 1731 bool reguard_stack(address cur_sp); 1732 // Similar to above but see if current stackpoint is out of the guard area 1733 // and reguard if possible. 1734 bool reguard_stack(void); 1735 1736 address stack_overflow_limit() { return _stack_overflow_limit; } 1737 void set_stack_overflow_limit() { 1738 _stack_overflow_limit = 1739 stack_end() + MAX2(JavaThread::stack_guard_zone_size(), JavaThread::stack_shadow_zone_size()); 1740 } 1741 1742 // Misc. accessors/mutators 1743 void set_do_not_unlock(void) { _do_not_unlock_if_synchronized = true; } 1744 void clr_do_not_unlock(void) { _do_not_unlock_if_synchronized = false; } 1745 bool do_not_unlock(void) { return _do_not_unlock_if_synchronized; } 1746 1747 #ifndef PRODUCT 1748 void record_jump(address target, address instr, const char* file, int line); 1749 #endif // PRODUCT 1750 1751 // For assembly stub generation 1752 static ByteSize threadObj_offset() { return byte_offset_of(JavaThread, _threadObj); } 1753 #ifndef PRODUCT 1754 static ByteSize jmp_ring_index_offset() { return byte_offset_of(JavaThread, _jmp_ring_index); } 1755 static ByteSize jmp_ring_offset() { return byte_offset_of(JavaThread, _jmp_ring); } 1756 #endif // PRODUCT 1757 static ByteSize jni_environment_offset() { return byte_offset_of(JavaThread, _jni_environment); } 1758 static ByteSize pending_jni_exception_check_fn_offset() { 1759 return byte_offset_of(JavaThread, _pending_jni_exception_check_fn); 1760 } 1761 static ByteSize last_Java_sp_offset() { 1762 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset(); 1763 } 1764 static ByteSize last_Java_pc_offset() { 1765 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset(); 1766 } 1767 static ByteSize frame_anchor_offset() { 1768 return byte_offset_of(JavaThread, _anchor); 1769 } 1770 static ByteSize callee_target_offset() { return byte_offset_of(JavaThread, _callee_target); } 1771 static ByteSize vm_result_offset() { return byte_offset_of(JavaThread, _vm_result); } 1772 static ByteSize vm_result_2_offset() { return byte_offset_of(JavaThread, _vm_result_2); } 1773 static ByteSize thread_state_offset() { return byte_offset_of(JavaThread, _thread_state); } 1774 static ByteSize saved_exception_pc_offset() { return byte_offset_of(JavaThread, _saved_exception_pc); } 1775 static ByteSize osthread_offset() { return byte_offset_of(JavaThread, _osthread); } 1776 #if INCLUDE_JVMCI 1777 static ByteSize pending_deoptimization_offset() { return byte_offset_of(JavaThread, _pending_deoptimization); } 1778 static ByteSize pending_monitorenter_offset() { return byte_offset_of(JavaThread, _pending_monitorenter); } 1779 static ByteSize pending_failed_speculation_offset() { return byte_offset_of(JavaThread, _pending_failed_speculation); } 1780 static ByteSize jvmci_alternate_call_target_offset() { return byte_offset_of(JavaThread, _jvmci._alternate_call_target); } 1781 static ByteSize jvmci_implicit_exception_pc_offset() { return byte_offset_of(JavaThread, _jvmci._implicit_exception_pc); } 1782 static ByteSize jvmci_counters_offset() { return byte_offset_of(JavaThread, _jvmci_counters); } 1783 #endif // INCLUDE_JVMCI 1784 static ByteSize exception_oop_offset() { return byte_offset_of(JavaThread, _exception_oop); } 1785 static ByteSize exception_pc_offset() { return byte_offset_of(JavaThread, _exception_pc); } 1786 static ByteSize exception_handler_pc_offset() { return byte_offset_of(JavaThread, _exception_handler_pc); } 1787 static ByteSize stack_overflow_limit_offset() { return byte_offset_of(JavaThread, _stack_overflow_limit); } 1788 static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); } 1789 static ByteSize stack_guard_state_offset() { return byte_offset_of(JavaThread, _stack_guard_state); } 1790 static ByteSize reserved_stack_activation_offset() { return byte_offset_of(JavaThread, _reserved_stack_activation); } 1791 static ByteSize suspend_flags_offset() { return byte_offset_of(JavaThread, _suspend_flags); } 1792 1793 static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); } 1794 static ByteSize should_post_on_exceptions_flag_offset() { 1795 return byte_offset_of(JavaThread, _should_post_on_exceptions_flag); 1796 } 1797 1798 // Returns the jni environment for this thread 1799 JNIEnv* jni_environment() { return &_jni_environment; } 1800 1801 static JavaThread* thread_from_jni_environment(JNIEnv* env) { 1802 JavaThread *thread_from_jni_env = (JavaThread*)((intptr_t)env - in_bytes(jni_environment_offset())); 1803 // Only return NULL if thread is off the thread list; starting to 1804 // exit should not return NULL. 1805 if (thread_from_jni_env->is_terminated()) { 1806 thread_from_jni_env->block_if_vm_exited(); 1807 return NULL; 1808 } else { 1809 return thread_from_jni_env; 1810 } 1811 } 1812 1813 // JNI critical regions. These can nest. 1814 bool in_critical() { return _jni_active_critical > 0; } 1815 bool in_last_critical() { return _jni_active_critical == 1; } 1816 inline void enter_critical(); 1817 void exit_critical() { 1818 assert(Thread::current() == this, "this must be current thread"); 1819 _jni_active_critical--; 1820 assert(_jni_active_critical >= 0, "JNI critical nesting problem?"); 1821 } 1822 1823 // Checked JNI: is the programmer required to check for exceptions, if so specify 1824 // which function name. Returning to a Java frame should implicitly clear the 1825 // pending check, this is done for Native->Java transitions (i.e. user JNI code). 1826 // VM->Java transistions are not cleared, it is expected that JNI code enclosed 1827 // within ThreadToNativeFromVM makes proper exception checks (i.e. VM internal). 1828 bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != NULL; } 1829 void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = NULL; } 1830 const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; } 1831 void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; } 1832 1833 // For deadlock detection 1834 int depth_first_number() { return _depth_first_number; } 1835 void set_depth_first_number(int dfn) { _depth_first_number = dfn; } 1836 1837 private: 1838 void set_monitor_chunks(MonitorChunk* monitor_chunks) { _monitor_chunks = monitor_chunks; } 1839 1840 public: 1841 MonitorChunk* monitor_chunks() const { return _monitor_chunks; } 1842 void add_monitor_chunk(MonitorChunk* chunk); 1843 void remove_monitor_chunk(MonitorChunk* chunk); 1844 bool in_deopt_handler() const { return _in_deopt_handler > 0; } 1845 void inc_in_deopt_handler() { _in_deopt_handler++; } 1846 void dec_in_deopt_handler() { 1847 assert(_in_deopt_handler > 0, "mismatched deopt nesting"); 1848 if (_in_deopt_handler > 0) { // robustness 1849 _in_deopt_handler--; 1850 } 1851 } 1852 1853 private: 1854 void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; } 1855 1856 public: 1857 1858 // Frame iteration; calls the function f for all frames on the stack 1859 void frames_do(void f(frame*, const RegisterMap*)); 1860 1861 // Memory operations 1862 void oops_do(OopClosure* f, CodeBlobClosure* cf); 1863 1864 // Sweeper operations 1865 virtual void nmethods_do(CodeBlobClosure* cf); 1866 1867 // RedefineClasses Support 1868 void metadata_do(MetadataClosure* f); 1869 1870 // Debug method asserting thread states are correct during a handshake operation. 1871 DEBUG_ONLY(void verify_states_for_handshake();) 1872 1873 // Misc. operations 1874 char* name() const { return (char*)get_thread_name(); } 1875 void print_on(outputStream* st, bool print_extended_info) const; 1876 void print_on(outputStream* st) const { print_on(st, false); } 1877 void print_value(); 1878 void print_thread_state_on(outputStream*) const PRODUCT_RETURN; 1879 void print_thread_state() const PRODUCT_RETURN; 1880 void print_on_error(outputStream* st, char* buf, int buflen) const; 1881 void print_name_on_error(outputStream* st, char* buf, int buflen) const; 1882 void verify(); 1883 const char* get_thread_name() const; 1884 protected: 1885 // factor out low-level mechanics for use in both normal and error cases 1886 virtual const char* get_thread_name_string(char* buf = NULL, int buflen = 0) const; 1887 public: 1888 const char* get_threadgroup_name() const; 1889 const char* get_parent_name() const; 1890 1891 // Accessing frames 1892 frame last_frame() { 1893 _anchor.make_walkable(this); 1894 return pd_last_frame(); 1895 } 1896 javaVFrame* last_java_vframe(RegisterMap* reg_map); 1897 1898 // Returns method at 'depth' java or native frames down the stack 1899 // Used for security checks 1900 Klass* security_get_caller_class(int depth); 1901 1902 // Print stack trace in external format 1903 void print_stack_on(outputStream* st); 1904 void print_stack() { print_stack_on(tty); } 1905 1906 // Print stack traces in various internal formats 1907 void trace_stack() PRODUCT_RETURN; 1908 void trace_stack_from(vframe* start_vf) PRODUCT_RETURN; 1909 void trace_frames() PRODUCT_RETURN; 1910 void trace_oops() PRODUCT_RETURN; 1911 1912 // Print an annotated view of the stack frames 1913 void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN; 1914 void validate_frame_layout() { 1915 print_frame_layout(0, true); 1916 } 1917 1918 // Returns the number of stack frames on the stack 1919 int depth() const; 1920 1921 // Function for testing deoptimization 1922 void deoptimize(); 1923 void make_zombies(); 1924 1925 void deoptimize_marked_methods(bool in_handshake); 1926 1927 public: 1928 // Returns the running thread as a JavaThread 1929 static inline JavaThread* current(); 1930 1931 // Returns the active Java thread. Do not use this if you know you are calling 1932 // from a JavaThread, as it's slower than JavaThread::current. If called from 1933 // the VMThread, it also returns the JavaThread that instigated the VMThread's 1934 // operation. You may not want that either. 1935 static JavaThread* active(); 1936 1937 inline CompilerThread* as_CompilerThread(); 1938 1939 protected: 1940 virtual void pre_run(); 1941 virtual void run(); 1942 void thread_main_inner(); 1943 virtual void post_run(); 1944 1945 1946 private: 1947 GrowableArray<oop>* _array_for_gc; 1948 public: 1949 1950 void register_array_for_gc(GrowableArray<oop>* array) { _array_for_gc = array; } 1951 1952 public: 1953 // Thread local information maintained by JVMTI. 1954 void set_jvmti_thread_state(JvmtiThreadState *value) { _jvmti_thread_state = value; } 1955 // A JvmtiThreadState is lazily allocated. This jvmti_thread_state() 1956 // getter is used to get this JavaThread's JvmtiThreadState if it has 1957 // one which means NULL can be returned. JvmtiThreadState::state_for() 1958 // is used to get the specified JavaThread's JvmtiThreadState if it has 1959 // one or it allocates a new JvmtiThreadState for the JavaThread and 1960 // returns it. JvmtiThreadState::state_for() will return NULL only if 1961 // the specified JavaThread is exiting. 1962 JvmtiThreadState *jvmti_thread_state() const { return _jvmti_thread_state; } 1963 static ByteSize jvmti_thread_state_offset() { return byte_offset_of(JavaThread, _jvmti_thread_state); } 1964 1965 // JVMTI PopFrame support 1966 // Setting and clearing popframe_condition 1967 // All of these enumerated values are bits. popframe_pending 1968 // indicates that a PopFrame() has been requested and not yet been 1969 // completed. popframe_processing indicates that that PopFrame() is in 1970 // the process of being completed. popframe_force_deopt_reexecution_bit 1971 // indicates that special handling is required when returning to a 1972 // deoptimized caller. 1973 enum PopCondition { 1974 popframe_inactive = 0x00, 1975 popframe_pending_bit = 0x01, 1976 popframe_processing_bit = 0x02, 1977 popframe_force_deopt_reexecution_bit = 0x04 1978 }; 1979 PopCondition popframe_condition() { return (PopCondition) _popframe_condition; } 1980 void set_popframe_condition(PopCondition c) { _popframe_condition = c; } 1981 void set_popframe_condition_bit(PopCondition c) { _popframe_condition |= c; } 1982 void clear_popframe_condition() { _popframe_condition = popframe_inactive; } 1983 static ByteSize popframe_condition_offset() { return byte_offset_of(JavaThread, _popframe_condition); } 1984 bool has_pending_popframe() { return (popframe_condition() & popframe_pending_bit) != 0; } 1985 bool popframe_forcing_deopt_reexecution() { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; } 1986 void clear_popframe_forcing_deopt_reexecution() { _popframe_condition &= ~popframe_force_deopt_reexecution_bit; } 1987 #ifdef CC_INTERP 1988 bool pop_frame_pending(void) { return ((_popframe_condition & popframe_pending_bit) != 0); } 1989 void clr_pop_frame_pending(void) { _popframe_condition = popframe_inactive; } 1990 bool pop_frame_in_process(void) { return ((_popframe_condition & popframe_processing_bit) != 0); } 1991 void set_pop_frame_in_process(void) { _popframe_condition |= popframe_processing_bit; } 1992 void clr_pop_frame_in_process(void) { _popframe_condition &= ~popframe_processing_bit; } 1993 #endif 1994 1995 int frames_to_pop_failed_realloc() const { return _frames_to_pop_failed_realloc; } 1996 void set_frames_to_pop_failed_realloc(int nb) { _frames_to_pop_failed_realloc = nb; } 1997 void dec_frames_to_pop_failed_realloc() { _frames_to_pop_failed_realloc--; } 1998 1999 private: 2000 // Saved incoming arguments to popped frame. 2001 // Used only when popped interpreted frame returns to deoptimized frame. 2002 void* _popframe_preserved_args; 2003 int _popframe_preserved_args_size; 2004 2005 public: 2006 void popframe_preserve_args(ByteSize size_in_bytes, void* start); 2007 void* popframe_preserved_args(); 2008 ByteSize popframe_preserved_args_size(); 2009 WordSize popframe_preserved_args_size_in_words(); 2010 void popframe_free_preserved_args(); 2011 2012 2013 private: 2014 JvmtiThreadState *_jvmti_thread_state; 2015 2016 // Used by the interpreter in fullspeed mode for frame pop, method 2017 // entry, method exit and single stepping support. This field is 2018 // only set to non-zero by the VM_EnterInterpOnlyMode VM operation. 2019 // It can be set to zero asynchronously (i.e., without a VM operation 2020 // or a lock) so we have to be very careful. 2021 int _interp_only_mode; 2022 2023 public: 2024 // used by the interpreter for fullspeed debugging support (see above) 2025 static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); } 2026 bool is_interp_only_mode() { return (_interp_only_mode != 0); } 2027 int get_interp_only_mode() { return _interp_only_mode; } 2028 void increment_interp_only_mode() { ++_interp_only_mode; } 2029 void decrement_interp_only_mode() { --_interp_only_mode; } 2030 2031 // support for cached flag that indicates whether exceptions need to be posted for this thread 2032 // if this is false, we can avoid deoptimizing when events are thrown 2033 // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything 2034 private: 2035 int _should_post_on_exceptions_flag; 2036 2037 public: 2038 int should_post_on_exceptions_flag() { return _should_post_on_exceptions_flag; } 2039 void set_should_post_on_exceptions_flag(int val) { _should_post_on_exceptions_flag = val; } 2040 2041 private: 2042 ThreadStatistics *_thread_stat; 2043 2044 public: 2045 ThreadStatistics* get_thread_stat() const { return _thread_stat; } 2046 2047 // Return a blocker object for which this thread is blocked parking. 2048 oop current_park_blocker(); 2049 2050 private: 2051 static size_t _stack_size_at_create; 2052 2053 public: 2054 static inline size_t stack_size_at_create(void) { 2055 return _stack_size_at_create; 2056 } 2057 static inline void set_stack_size_at_create(size_t value) { 2058 _stack_size_at_create = value; 2059 } 2060 2061 // Machine dependent stuff 2062 #include OS_CPU_HEADER(thread) 2063 2064 public: 2065 void set_blocked_on_compilation(bool value) { 2066 _blocked_on_compilation = value; 2067 } 2068 2069 bool blocked_on_compilation() { 2070 return _blocked_on_compilation; 2071 } 2072 protected: 2073 bool _blocked_on_compilation; 2074 2075 2076 // JSR166 per-thread parker 2077 private: 2078 Parker* _parker; 2079 public: 2080 Parker* parker() { return _parker; } 2081 2082 // Biased locking support 2083 private: 2084 GrowableArray<MonitorInfo*>* _cached_monitor_info; 2085 public: 2086 GrowableArray<MonitorInfo*>* cached_monitor_info() { return _cached_monitor_info; } 2087 void set_cached_monitor_info(GrowableArray<MonitorInfo*>* info) { _cached_monitor_info = info; } 2088 2089 // clearing/querying jni attach status 2090 bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; } 2091 bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; } 2092 inline void set_done_attaching_via_jni(); 2093 2094 // Stack dump assistance: 2095 // Track the class we want to initialize but for which we have to wait 2096 // on its init_lock() because it is already being initialized. 2097 void set_class_to_be_initialized(InstanceKlass* k); 2098 InstanceKlass* class_to_be_initialized() const; 2099 2100 private: 2101 InstanceKlass* _class_to_be_initialized; 2102 2103 }; 2104 2105 // Inline implementation of JavaThread::current 2106 inline JavaThread* JavaThread::current() { 2107 Thread* thread = Thread::current(); 2108 assert(thread->is_Java_thread(), "just checking"); 2109 return (JavaThread*)thread; 2110 } 2111 2112 inline CompilerThread* JavaThread::as_CompilerThread() { 2113 assert(is_Compiler_thread(), "just checking"); 2114 return (CompilerThread*)this; 2115 } 2116 2117 // Dedicated thread to sweep the code cache 2118 class CodeCacheSweeperThread : public JavaThread { 2119 CompiledMethod* _scanned_compiled_method; // nmethod being scanned by the sweeper 2120 public: 2121 CodeCacheSweeperThread(); 2122 // Track the nmethod currently being scanned by the sweeper 2123 void set_scanned_compiled_method(CompiledMethod* cm) { 2124 assert(_scanned_compiled_method == NULL || cm == NULL, "should reset to NULL before writing a new value"); 2125 _scanned_compiled_method = cm; 2126 } 2127 2128 // Hide sweeper thread from external view. 2129 bool is_hidden_from_external_view() const { return true; } 2130 2131 bool is_Code_cache_sweeper_thread() const { return true; } 2132 2133 // Prevent GC from unloading _scanned_compiled_method 2134 void oops_do(OopClosure* f, CodeBlobClosure* cf); 2135 void nmethods_do(CodeBlobClosure* cf); 2136 }; 2137 2138 // A thread used for Compilation. 2139 class CompilerThread : public JavaThread { 2140 friend class VMStructs; 2141 private: 2142 CompilerCounters* _counters; 2143 2144 ciEnv* _env; 2145 CompileLog* _log; 2146 CompileTask* volatile _task; // print_threads_compiling can read this concurrently. 2147 CompileQueue* _queue; 2148 BufferBlob* _buffer_blob; 2149 2150 AbstractCompiler* _compiler; 2151 TimeStamp _idle_time; 2152 2153 public: 2154 2155 static CompilerThread* current(); 2156 2157 CompilerThread(CompileQueue* queue, CompilerCounters* counters); 2158 ~CompilerThread(); 2159 2160 bool is_Compiler_thread() const { return true; } 2161 2162 virtual bool can_call_java() const; 2163 2164 // Hide native compiler threads from external view. 2165 bool is_hidden_from_external_view() const { return !can_call_java(); } 2166 2167 void set_compiler(AbstractCompiler* c) { _compiler = c; } 2168 AbstractCompiler* compiler() const { return _compiler; } 2169 2170 CompileQueue* queue() const { return _queue; } 2171 CompilerCounters* counters() const { return _counters; } 2172 2173 // Get/set the thread's compilation environment. 2174 ciEnv* env() { return _env; } 2175 void set_env(ciEnv* env) { _env = env; } 2176 2177 BufferBlob* get_buffer_blob() const { return _buffer_blob; } 2178 void set_buffer_blob(BufferBlob* b) { _buffer_blob = b; } 2179 2180 // Get/set the thread's logging information 2181 CompileLog* log() { return _log; } 2182 void init_log(CompileLog* log) { 2183 // Set once, for good. 2184 assert(_log == NULL, "set only once"); 2185 _log = log; 2186 } 2187 2188 void start_idle_timer() { _idle_time.update(); } 2189 jlong idle_time_millis() { 2190 return TimeHelper::counter_to_millis(_idle_time.ticks_since_update()); 2191 } 2192 2193 #ifndef PRODUCT 2194 private: 2195 IdealGraphPrinter *_ideal_graph_printer; 2196 public: 2197 IdealGraphPrinter *ideal_graph_printer() { return _ideal_graph_printer; } 2198 void set_ideal_graph_printer(IdealGraphPrinter *n) { _ideal_graph_printer = n; } 2199 #endif 2200 2201 // Get/set the thread's current task 2202 CompileTask* task() { return _task; } 2203 void set_task(CompileTask* task) { _task = task; } 2204 }; 2205 2206 inline CompilerThread* CompilerThread::current() { 2207 return JavaThread::current()->as_CompilerThread(); 2208 } 2209 2210 // The active thread queue. It also keeps track of the current used 2211 // thread priorities. 2212 class Threads: AllStatic { 2213 friend class VMStructs; 2214 private: 2215 static JavaThread* _thread_list; 2216 static int _number_of_threads; 2217 static int _number_of_non_daemon_threads; 2218 static int _return_code; 2219 static uintx _thread_claim_token; 2220 #ifdef ASSERT 2221 static bool _vm_complete; 2222 #endif 2223 2224 static void initialize_java_lang_classes(JavaThread* main_thread, TRAPS); 2225 static void initialize_jsr292_core_classes(TRAPS); 2226 2227 public: 2228 // Thread management 2229 // force_daemon is a concession to JNI, where we may need to add a 2230 // thread to the thread list before allocating its thread object 2231 static void add(JavaThread* p, bool force_daemon = false); 2232 static void remove(JavaThread* p, bool is_daemon); 2233 static void non_java_threads_do(ThreadClosure* tc); 2234 static void java_threads_do(ThreadClosure* tc); 2235 static void java_threads_and_vm_thread_do(ThreadClosure* tc); 2236 static void threads_do(ThreadClosure* tc); 2237 static void possibly_parallel_threads_do(bool is_par, ThreadClosure* tc); 2238 2239 // Initializes the vm and creates the vm thread 2240 static jint create_vm(JavaVMInitArgs* args, bool* canTryAgain); 2241 static void convert_vm_init_libraries_to_agents(); 2242 static void create_vm_init_libraries(); 2243 static void create_vm_init_agents(); 2244 static void shutdown_vm_agents(); 2245 static bool destroy_vm(); 2246 // Supported VM versions via JNI 2247 // Includes JNI_VERSION_1_1 2248 static jboolean is_supported_jni_version_including_1_1(jint version); 2249 // Does not include JNI_VERSION_1_1 2250 static jboolean is_supported_jni_version(jint version); 2251 2252 // The "thread claim token" provides a way for threads to be claimed 2253 // by parallel worker tasks. 2254 // 2255 // Each thread contains a "token" field. A task will claim the 2256 // thread only if its token is different from the global token, 2257 // which is updated by calling change_thread_claim_token(). When 2258 // a thread is claimed, it's token is set to the global token value 2259 // so other threads in the same iteration pass won't claim it. 2260 // 2261 // For this to work change_thread_claim_token() needs to be called 2262 // exactly once in sequential code before starting parallel tasks 2263 // that should claim threads. 2264 // 2265 // New threads get their token set to 0 and change_thread_claim_token() 2266 // never sets the global token to 0. 2267 static uintx thread_claim_token() { return _thread_claim_token; } 2268 static void change_thread_claim_token(); 2269 static void assert_all_threads_claimed() NOT_DEBUG_RETURN; 2270 2271 // Apply "f->do_oop" to all root oops in all threads. 2272 // This version may only be called by sequential code. 2273 static void oops_do(OopClosure* f, CodeBlobClosure* cf); 2274 // This version may be called by sequential or parallel code. 2275 static void possibly_parallel_oops_do(bool is_par, OopClosure* f, CodeBlobClosure* cf); 2276 2277 // Apply "f->do_oop" to roots in all threads that 2278 // are part of compiled frames 2279 static void compiled_frame_oops_do(OopClosure* f, CodeBlobClosure* cf); 2280 2281 static void convert_hcode_pointers(); 2282 static void restore_hcode_pointers(); 2283 2284 // Sweeper 2285 static void nmethods_do(CodeBlobClosure* cf); 2286 2287 // RedefineClasses support 2288 static void metadata_do(MetadataClosure* f); 2289 static void metadata_handles_do(void f(Metadata*)); 2290 2291 #ifdef ASSERT 2292 static bool is_vm_complete() { return _vm_complete; } 2293 #endif // ASSERT 2294 2295 // Verification 2296 static void verify(); 2297 static void print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks, bool print_extended_info); 2298 static void print(bool print_stacks, bool internal_format) { 2299 // this function is only used by debug.cpp 2300 print_on(tty, print_stacks, internal_format, false /* no concurrent lock printed */, false /* simple format */); 2301 } 2302 static void print_on_error(outputStream* st, Thread* current, char* buf, int buflen); 2303 static void print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf, 2304 int buflen, bool* found_current); 2305 static void print_threads_compiling(outputStream* st, char* buf, int buflen, bool short_form = false); 2306 2307 // Get Java threads that are waiting to enter a monitor. 2308 static GrowableArray<JavaThread*>* get_pending_threads(ThreadsList * t_list, 2309 int count, address monitor); 2310 2311 // Get owning Java thread from the monitor's owner field. 2312 static JavaThread *owning_thread_from_monitor_owner(ThreadsList * t_list, 2313 address owner); 2314 2315 // Number of threads on the active threads list 2316 static int number_of_threads() { return _number_of_threads; } 2317 // Number of non-daemon threads on the active threads list 2318 static int number_of_non_daemon_threads() { return _number_of_non_daemon_threads; } 2319 2320 // Deoptimizes all frames tied to marked nmethods 2321 static void deoptimized_wrt_marked_nmethods(); 2322 2323 struct Test; // For private gtest access. 2324 }; 2325 2326 2327 // Thread iterator 2328 class ThreadClosure: public StackObj { 2329 public: 2330 virtual void do_thread(Thread* thread) = 0; 2331 }; 2332 2333 class SignalHandlerMark: public StackObj { 2334 private: 2335 Thread* _thread; 2336 public: 2337 SignalHandlerMark(Thread* t) { 2338 _thread = t; 2339 if (_thread) _thread->enter_signal_handler(); 2340 } 2341 ~SignalHandlerMark() { 2342 if (_thread) _thread->leave_signal_handler(); 2343 _thread = NULL; 2344 } 2345 }; 2346 2347 2348 #endif // SHARE_RUNTIME_THREAD_HPP