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 Metadata; 92 class ResourceArea; 93 94 DEBUG_ONLY(class ResourceMark;) 95 96 class WorkerThread; 97 98 // Class hierarchy 99 // - Thread 100 // - JavaThread 101 // - various subclasses eg CompilerThread, ServiceThread 102 // - NonJavaThread 103 // - NamedThread 104 // - VMThread 105 // - ConcurrentGCThread 106 // - WorkerThread 107 // - GangWorker 108 // - GCTaskThread 109 // - WatcherThread 110 // - JfrThreadSampler 111 // 112 // All Thread subclasses must be either JavaThread or NonJavaThread. 113 // This means !t->is_Java_thread() iff t is a NonJavaThread, or t is 114 // a partially constructed/destroyed Thread. 115 116 // Thread execution sequence and actions: 117 // All threads: 118 // - thread_native_entry // per-OS native entry point 119 // - stack initialization 120 // - other OS-level initialization (signal masks etc) 121 // - handshake with creating thread (if not started suspended) 122 // - this->call_run() // common shared entry point 123 // - shared common initialization 124 // - this->pre_run() // virtual per-thread-type initialization 125 // - this->run() // virtual per-thread-type "main" logic 126 // - shared common tear-down 127 // - this->post_run() // virtual per-thread-type tear-down 128 // - // 'this' no longer referenceable 129 // - OS-level tear-down (minimal) 130 // - final logging 131 // 132 // For JavaThread: 133 // - this->run() // virtual but not normally overridden 134 // - this->thread_main_inner() // extra call level to ensure correct stack calculations 135 // - this->entry_point() // set differently for each kind of JavaThread 136 137 class Thread: public ThreadShadow { 138 friend class VMStructs; 139 friend class JVMCIVMStructs; 140 private: 141 142 #ifndef USE_LIBRARY_BASED_TLS_ONLY 143 // Current thread is maintained as a thread-local variable 144 static THREAD_LOCAL_DECL Thread* _thr_current; 145 #endif 146 147 // Thread local data area available to the GC. The internal 148 // structure and contents of this data area is GC-specific. 149 // Only GC and GC barrier code should access this data area. 150 GCThreadLocalData _gc_data; 151 152 public: 153 static ByteSize gc_data_offset() { 154 return byte_offset_of(Thread, _gc_data); 155 } 156 157 template <typename T> T* gc_data() { 158 STATIC_ASSERT(sizeof(T) <= sizeof(_gc_data)); 159 return reinterpret_cast<T*>(&_gc_data); 160 } 161 162 // Exception handling 163 // (Note: _pending_exception and friends are in ThreadShadow) 164 //oop _pending_exception; // pending exception for current thread 165 // const char* _exception_file; // file information for exception (debugging only) 166 // int _exception_line; // line information for exception (debugging only) 167 protected: 168 169 DEBUG_ONLY(static Thread* _starting_thread;) 170 171 // Support for forcing alignment of thread objects for biased locking 172 void* _real_malloc_address; 173 174 // JavaThread lifecycle support: 175 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 176 friend class ScanHazardPtrGatherProtectedThreadsClosure; // for cmpxchg_threads_hazard_ptr(), get_threads_hazard_ptr(), is_hazard_ptr_tagged() access 177 friend class ScanHazardPtrGatherThreadsListClosure; // for get_threads_hazard_ptr(), untag_hazard_ptr() access 178 friend class ScanHazardPtrPrintMatchingThreadsClosure; // for get_threads_hazard_ptr(), is_hazard_ptr_tagged() access 179 friend class ThreadsSMRSupport; // for _nested_threads_hazard_ptr_cnt, _threads_hazard_ptr, _threads_list_ptr access 180 181 ThreadsList* volatile _threads_hazard_ptr; 182 SafeThreadsListPtr* _threads_list_ptr; 183 ThreadsList* cmpxchg_threads_hazard_ptr(ThreadsList* exchange_value, ThreadsList* compare_value); 184 ThreadsList* get_threads_hazard_ptr(); 185 void set_threads_hazard_ptr(ThreadsList* new_list); 186 static bool is_hazard_ptr_tagged(ThreadsList* list) { 187 return (intptr_t(list) & intptr_t(1)) == intptr_t(1); 188 } 189 static ThreadsList* tag_hazard_ptr(ThreadsList* list) { 190 return (ThreadsList*)(intptr_t(list) | intptr_t(1)); 191 } 192 static ThreadsList* untag_hazard_ptr(ThreadsList* list) { 193 return (ThreadsList*)(intptr_t(list) & ~intptr_t(1)); 194 } 195 // This field is enabled via -XX:+EnableThreadSMRStatistics: 196 uint _nested_threads_hazard_ptr_cnt; 197 void dec_nested_threads_hazard_ptr_cnt() { 198 assert(_nested_threads_hazard_ptr_cnt != 0, "mismatched {dec,inc}_nested_threads_hazard_ptr_cnt()"); 199 _nested_threads_hazard_ptr_cnt--; 200 } 201 void inc_nested_threads_hazard_ptr_cnt() { 202 _nested_threads_hazard_ptr_cnt++; 203 } 204 uint nested_threads_hazard_ptr_cnt() { 205 return _nested_threads_hazard_ptr_cnt; 206 } 207 208 public: 209 void* operator new(size_t size) throw() { return allocate(size, true); } 210 void* operator new(size_t size, const std::nothrow_t& nothrow_constant) throw() { 211 return allocate(size, false); } 212 void operator delete(void* p); 213 214 protected: 215 static void* allocate(size_t size, bool throw_excpt, MEMFLAGS flags = mtThread); 216 private: 217 218 // *************************************************************** 219 // Suspend and resume support 220 // *************************************************************** 221 // 222 // VM suspend/resume no longer exists - it was once used for various 223 // things including safepoints but was deprecated and finally removed 224 // in Java 7. Because VM suspension was considered "internal" Java-level 225 // suspension was considered "external", and this legacy naming scheme 226 // remains. 227 // 228 // External suspend/resume requests come from JVM_SuspendThread, 229 // JVM_ResumeThread, JVMTI SuspendThread, and finally JVMTI 230 // ResumeThread. External 231 // suspend requests cause _external_suspend to be set and external 232 // resume requests cause _external_suspend to be cleared. 233 // External suspend requests do not nest on top of other external 234 // suspend requests. The higher level APIs reject suspend requests 235 // for already suspended threads. 236 // 237 // The external_suspend 238 // flag is checked by has_special_runtime_exit_condition() and java thread 239 // will self-suspend when handle_special_runtime_exit_condition() is 240 // called. Most uses of the _thread_blocked state in JavaThreads are 241 // considered the same as being externally suspended; if the blocking 242 // condition lifts, the JavaThread will self-suspend. Other places 243 // where VM checks for external_suspend include: 244 // + mutex granting (do not enter monitors when thread is suspended) 245 // + state transitions from _thread_in_native 246 // 247 // In general, java_suspend() does not wait for an external suspend 248 // request to complete. When it returns, the only guarantee is that 249 // the _external_suspend field is true. 250 // 251 // wait_for_ext_suspend_completion() is used to wait for an external 252 // suspend request to complete. External suspend requests are usually 253 // followed by some other interface call that requires the thread to 254 // be quiescent, e.g., GetCallTrace(). By moving the "wait time" into 255 // the interface that requires quiescence, we give the JavaThread a 256 // chance to self-suspend before we need it to be quiescent. This 257 // improves overall suspend/query performance. 258 // 259 // _suspend_flags controls the behavior of java_ suspend/resume. 260 // It must be set under the protection of SR_lock. Read from the flag is 261 // OK without SR_lock as long as the value is only used as a hint. 262 // (e.g., check _external_suspend first without lock and then recheck 263 // inside SR_lock and finish the suspension) 264 // 265 // _suspend_flags is also overloaded for other "special conditions" so 266 // that a single check indicates whether any special action is needed 267 // eg. for async exceptions. 268 // ------------------------------------------------------------------- 269 // Notes: 270 // 1. The suspend/resume logic no longer uses ThreadState in OSThread 271 // but we still update its value to keep other part of the system (mainly 272 // JVMTI) happy. ThreadState is legacy code (see notes in 273 // osThread.hpp). 274 // 275 // 2. It would be more natural if set_external_suspend() is private and 276 // part of java_suspend(), but that probably would affect the suspend/query 277 // performance. Need more investigation on this. 278 279 // suspend/resume lock: used for self-suspend 280 Monitor* _SR_lock; 281 282 protected: 283 enum SuspendFlags { 284 // NOTE: avoid using the sign-bit as cc generates different test code 285 // when the sign-bit is used, and sometimes incorrectly - see CR 6398077 286 287 _external_suspend = 0x20000000U, // thread is asked to self suspend 288 _ext_suspended = 0x40000000U, // thread has self-suspended 289 _deopt_suspend = 0x10000000U, // thread needs to self suspend for deopt 290 291 _has_async_exception = 0x00000001U, // there is a pending async exception 292 _critical_native_unlock = 0x00000002U, // Must call back to unlock JNI critical lock 293 294 _trace_flag = 0x00000004U // call tracing backend 295 }; 296 297 // various suspension related flags - atomically updated 298 // overloaded for async exception checking in check_special_condition_for_native_trans. 299 volatile uint32_t _suspend_flags; 300 301 private: 302 int _num_nested_signal; 303 304 DEBUG_ONLY(bool _suspendible_thread;) 305 306 public: 307 void enter_signal_handler() { _num_nested_signal++; } 308 void leave_signal_handler() { _num_nested_signal--; } 309 bool is_inside_signal_handler() const { return _num_nested_signal > 0; } 310 311 // Determines if a heap allocation failure will be retried 312 // (e.g., by deoptimizing and re-executing in the interpreter). 313 // In this case, the failed allocation must raise 314 // Universe::out_of_memory_error_retry() and omit side effects 315 // such as JVMTI events and handling -XX:+HeapDumpOnOutOfMemoryError 316 // and -XX:OnOutOfMemoryError. 317 virtual bool in_retryable_allocation() const { return false; } 318 319 #ifdef ASSERT 320 void set_suspendible_thread() { 321 _suspendible_thread = true; 322 } 323 324 void clear_suspendible_thread() { 325 _suspendible_thread = false; 326 } 327 328 bool is_suspendible_thread() { return _suspendible_thread; } 329 #endif 330 331 private: 332 // Active_handles points to a block of handles 333 JNIHandleBlock* _active_handles; 334 335 // One-element thread local free list 336 JNIHandleBlock* _free_handle_block; 337 338 // Point to the last handle mark 339 HandleMark* _last_handle_mark; 340 341 // Claim value for parallel iteration over threads. 342 uintx _threads_do_token; 343 344 // Support for GlobalCounter 345 private: 346 volatile uintx _rcu_counter; 347 public: 348 volatile uintx* get_rcu_counter() { 349 return &_rcu_counter; 350 } 351 352 public: 353 void set_last_handle_mark(HandleMark* mark) { _last_handle_mark = mark; } 354 HandleMark* last_handle_mark() const { return _last_handle_mark; } 355 private: 356 357 #ifdef ASSERT 358 ICRefillVerifier* _missed_ic_stub_refill_verifier; 359 360 public: 361 ICRefillVerifier* missed_ic_stub_refill_verifier() { 362 return _missed_ic_stub_refill_verifier; 363 } 364 365 void set_missed_ic_stub_refill_verifier(ICRefillVerifier* verifier) { 366 _missed_ic_stub_refill_verifier = verifier; 367 } 368 #endif 369 370 private: 371 372 // debug support for checking if code does allow safepoints or not 373 // GC points in the VM can happen because of allocation, invoking a VM operation, or blocking on 374 // mutex, or blocking on an object synchronizer (Java locking). 375 // If !allow_safepoint(), then an assertion failure will happen in any of the above cases 376 // If !allow_allocation(), then an assertion failure will happen during allocation 377 // (Hence, !allow_safepoint() => !allow_allocation()). 378 // 379 // The two classes NoSafepointVerifier and No_Allocation_Verifier are used to set these counters. 380 // 381 NOT_PRODUCT(int _allow_safepoint_count;) // If 0, thread allow a safepoint to happen 382 debug_only(int _allow_allocation_count;) // If 0, the thread is allowed to allocate oops. 383 384 // Used by SkipGCALot class. 385 NOT_PRODUCT(bool _skip_gcalot;) // Should we elide gc-a-lot? 386 387 friend class NoAllocVerifier; 388 friend class NoSafepointVerifier; 389 friend class PauseNoSafepointVerifier; 390 friend class GCLocker; 391 392 volatile void* _polling_page; // Thread local polling page 393 394 ThreadLocalAllocBuffer _tlab; // Thread-local eden 395 jlong _allocated_bytes; // Cumulative number of bytes allocated on 396 // the Java heap 397 ThreadHeapSampler _heap_sampler; // For use when sampling the memory. 398 399 ThreadStatisticalInfo _statistical_info; // Statistics about the thread 400 401 JFR_ONLY(DEFINE_THREAD_LOCAL_FIELD_JFR;) // Thread-local data for jfr 402 403 int _vm_operation_started_count; // VM_Operation support 404 int _vm_operation_completed_count; // VM_Operation support 405 406 ObjectMonitor* _current_pending_monitor; // ObjectMonitor this thread 407 // is waiting to lock 408 bool _current_pending_monitor_is_from_java; // locking is from Java code 409 410 // ObjectMonitor on which this thread called Object.wait() 411 ObjectMonitor* _current_waiting_monitor; 412 413 // Private thread-local objectmonitor list - a simple cache organized as a SLL. 414 public: 415 ObjectMonitor* omFreeList; 416 int omFreeCount; // length of omFreeList 417 int omFreeProvision; // reload chunk size 418 ObjectMonitor* omInUseList; // SLL to track monitors in circulation 419 int omInUseCount; // length of omInUseList 420 421 #ifdef ASSERT 422 private: 423 volatile uint64_t _visited_for_critical_count; 424 425 public: 426 void set_visited_for_critical_count(uint64_t safepoint_id) { 427 assert(_visited_for_critical_count == 0, "Must be reset before set"); 428 assert((safepoint_id & 0x1) == 1, "Must be odd"); 429 _visited_for_critical_count = safepoint_id; 430 } 431 void reset_visited_for_critical_count(uint64_t safepoint_id) { 432 assert(_visited_for_critical_count == safepoint_id, "Was not visited"); 433 _visited_for_critical_count = 0; 434 } 435 bool was_visited_for_critical_count(uint64_t safepoint_id) const { 436 return _visited_for_critical_count == safepoint_id; 437 } 438 #endif 439 440 public: 441 enum { 442 is_definitely_current_thread = true 443 }; 444 445 // Constructor 446 Thread(); 447 virtual ~Thread() = 0; // Thread is abstract. 448 449 // Manage Thread::current() 450 void initialize_thread_current(); 451 static void clear_thread_current(); // TLS cleanup needed before threads terminate 452 453 protected: 454 // To be implemented by children. 455 virtual void run() = 0; 456 virtual void pre_run() = 0; 457 virtual void post_run() = 0; // Note: Thread must not be deleted prior to calling this! 458 459 #ifdef ASSERT 460 enum RunState { 461 PRE_CALL_RUN, 462 CALL_RUN, 463 PRE_RUN, 464 RUN, 465 POST_RUN 466 // POST_CALL_RUN - can't define this one as 'this' may be deleted when we want to set it 467 }; 468 RunState _run_state; // for lifecycle checks 469 #endif 470 471 472 public: 473 // invokes <ChildThreadClass>::run(), with common preparations and cleanups. 474 void call_run(); 475 476 // Testers 477 virtual bool is_VM_thread() const { return false; } 478 virtual bool is_Java_thread() const { return false; } 479 virtual bool is_Compiler_thread() const { return false; } 480 virtual bool is_Code_cache_sweeper_thread() const { return false; } 481 virtual bool is_hidden_from_external_view() const { return false; } 482 virtual bool is_jvmti_agent_thread() const { return false; } 483 // True iff the thread can perform GC operations at a safepoint. 484 // Generally will be true only of VM thread and parallel GC WorkGang 485 // threads. 486 virtual bool is_GC_task_thread() const { return false; } 487 virtual bool is_Watcher_thread() const { return false; } 488 virtual bool is_ConcurrentGC_thread() const { return false; } 489 virtual bool is_Named_thread() const { return false; } 490 virtual bool is_Worker_thread() const { return false; } 491 492 // Can this thread make Java upcalls 493 virtual bool can_call_java() const { return false; } 494 495 // Casts 496 virtual WorkerThread* as_Worker_thread() const { return NULL; } 497 498 virtual char* name() const { return (char*)"Unknown thread"; } 499 500 // Returns the current thread (ASSERTS if NULL) 501 static inline Thread* current(); 502 // Returns the current thread, or NULL if not attached 503 static inline Thread* current_or_null(); 504 // Returns the current thread, or NULL if not attached, and is 505 // safe for use from signal-handlers 506 static inline Thread* current_or_null_safe(); 507 508 // Common thread operations 509 #ifdef ASSERT 510 static void check_for_dangling_thread_pointer(Thread *thread); 511 #endif 512 static void set_priority(Thread* thread, ThreadPriority priority); 513 static ThreadPriority get_priority(const Thread* const thread); 514 static void start(Thread* thread); 515 static void interrupt(Thread* thr); 516 static bool is_interrupted(Thread* thr, bool clear_interrupted); 517 518 void set_native_thread_name(const char *name) { 519 assert(Thread::current() == this, "set_native_thread_name can only be called on the current thread"); 520 os::set_native_thread_name(name); 521 } 522 523 ObjectMonitor** omInUseList_addr() { return (ObjectMonitor **)&omInUseList; } 524 Monitor* SR_lock() const { return _SR_lock; } 525 526 bool has_async_exception() const { return (_suspend_flags & _has_async_exception) != 0; } 527 528 inline void set_suspend_flag(SuspendFlags f); 529 inline void clear_suspend_flag(SuspendFlags f); 530 531 inline void set_has_async_exception(); 532 inline void clear_has_async_exception(); 533 534 bool do_critical_native_unlock() const { return (_suspend_flags & _critical_native_unlock) != 0; } 535 536 inline void set_critical_native_unlock(); 537 inline void clear_critical_native_unlock(); 538 539 inline void set_trace_flag(); 540 inline void clear_trace_flag(); 541 542 // Support for Unhandled Oop detection 543 // Add the field for both, fastdebug and debug, builds to keep 544 // Thread's fields layout the same. 545 // Note: CHECK_UNHANDLED_OOPS is defined only for fastdebug build. 546 #ifdef CHECK_UNHANDLED_OOPS 547 private: 548 UnhandledOops* _unhandled_oops; 549 #elif defined(ASSERT) 550 private: 551 void* _unhandled_oops; 552 #endif 553 #ifdef CHECK_UNHANDLED_OOPS 554 public: 555 UnhandledOops* unhandled_oops() { return _unhandled_oops; } 556 // Mark oop safe for gc. It may be stack allocated but won't move. 557 void allow_unhandled_oop(oop *op) { 558 if (CheckUnhandledOops) unhandled_oops()->allow_unhandled_oop(op); 559 } 560 // Clear oops at safepoint so crashes point to unhandled oop violator 561 void clear_unhandled_oops() { 562 if (CheckUnhandledOops) unhandled_oops()->clear_unhandled_oops(); 563 } 564 #endif // CHECK_UNHANDLED_OOPS 565 566 public: 567 #ifndef PRODUCT 568 bool skip_gcalot() { return _skip_gcalot; } 569 void set_skip_gcalot(bool v) { _skip_gcalot = v; } 570 #endif 571 572 // Installs a pending exception to be inserted later 573 static void send_async_exception(oop thread_oop, oop java_throwable); 574 575 // Resource area 576 ResourceArea* resource_area() const { return _resource_area; } 577 void set_resource_area(ResourceArea* area) { _resource_area = area; } 578 579 OSThread* osthread() const { return _osthread; } 580 void set_osthread(OSThread* thread) { _osthread = thread; } 581 582 // JNI handle support 583 JNIHandleBlock* active_handles() const { return _active_handles; } 584 void set_active_handles(JNIHandleBlock* block) { _active_handles = block; } 585 JNIHandleBlock* free_handle_block() const { return _free_handle_block; } 586 void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; } 587 588 // Internal handle support 589 HandleArea* handle_area() const { return _handle_area; } 590 void set_handle_area(HandleArea* area) { _handle_area = area; } 591 592 GrowableArray<Metadata*>* metadata_handles() const { return _metadata_handles; } 593 void set_metadata_handles(GrowableArray<Metadata*>* handles){ _metadata_handles = handles; } 594 595 // Thread-Local Allocation Buffer (TLAB) support 596 ThreadLocalAllocBuffer& tlab() { return _tlab; } 597 void initialize_tlab() { 598 if (UseTLAB) { 599 tlab().initialize(); 600 } 601 } 602 603 jlong allocated_bytes() { return _allocated_bytes; } 604 void set_allocated_bytes(jlong value) { _allocated_bytes = value; } 605 void incr_allocated_bytes(jlong size) { _allocated_bytes += size; } 606 inline jlong cooked_allocated_bytes(); 607 608 ThreadHeapSampler& heap_sampler() { return _heap_sampler; } 609 610 ThreadStatisticalInfo& statistical_info() { return _statistical_info; } 611 612 JFR_ONLY(DEFINE_THREAD_LOCAL_ACCESSOR_JFR;) 613 614 bool is_trace_suspend() { return (_suspend_flags & _trace_flag) != 0; } 615 616 // VM operation support 617 int vm_operation_ticket() { return ++_vm_operation_started_count; } 618 int vm_operation_completed_count() { return _vm_operation_completed_count; } 619 void increment_vm_operation_completed_count() { _vm_operation_completed_count++; } 620 621 // For tracking the heavyweight monitor the thread is pending on. 622 ObjectMonitor* current_pending_monitor() { 623 return _current_pending_monitor; 624 } 625 void set_current_pending_monitor(ObjectMonitor* monitor) { 626 _current_pending_monitor = monitor; 627 } 628 void set_current_pending_monitor_is_from_java(bool from_java) { 629 _current_pending_monitor_is_from_java = from_java; 630 } 631 bool current_pending_monitor_is_from_java() { 632 return _current_pending_monitor_is_from_java; 633 } 634 635 // For tracking the ObjectMonitor on which this thread called Object.wait() 636 ObjectMonitor* current_waiting_monitor() { 637 return _current_waiting_monitor; 638 } 639 void set_current_waiting_monitor(ObjectMonitor* monitor) { 640 _current_waiting_monitor = monitor; 641 } 642 643 // GC support 644 // Apply "f->do_oop" to all root oops in "this". 645 // Used by JavaThread::oops_do. 646 // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames 647 virtual void oops_do(OopClosure* f, CodeBlobClosure* cf); 648 649 // Handles the parallel case for claim_threads_do. 650 private: 651 bool claim_par_threads_do(uintx claim_token); 652 public: 653 // Requires that "claim_token" is that of the current iteration. 654 // If "is_par" is false, sets the token of "this" to 655 // "claim_token", and returns "true". If "is_par" is true, 656 // uses an atomic instruction to set the current thread's token to 657 // "claim_token", if it is not already. Returns "true" iff the 658 // calling thread does the update, this indicates that the calling thread 659 // has claimed the thread in the current iteration. 660 bool claim_threads_do(bool is_par, uintx claim_token) { 661 if (!is_par) { 662 _threads_do_token = claim_token; 663 return true; 664 } else { 665 return claim_par_threads_do(claim_token); 666 } 667 } 668 669 uintx threads_do_token() const { return _threads_do_token; } 670 671 // jvmtiRedefineClasses support 672 void metadata_handles_do(void f(Metadata*)); 673 674 // Used by fast lock support 675 virtual bool is_lock_owned(address adr) const; 676 677 // Check if address is in the stack of the thread (not just for locks). 678 // Warning: the method can only be used on the running thread 679 bool is_in_stack(address adr) const; 680 // Check if address is in the usable part of the stack (excludes protected 681 // guard pages) 682 bool is_in_usable_stack(address adr) const; 683 684 // Sets this thread as starting thread. Returns failure if thread 685 // creation fails due to lack of memory, too many threads etc. 686 bool set_as_starting_thread(); 687 688 protected: 689 // OS data associated with the thread 690 OSThread* _osthread; // Platform-specific thread information 691 692 // Thread local resource area for temporary allocation within the VM 693 ResourceArea* _resource_area; 694 695 DEBUG_ONLY(ResourceMark* _current_resource_mark;) 696 697 // Thread local handle area for allocation of handles within the VM 698 HandleArea* _handle_area; 699 GrowableArray<Metadata*>* _metadata_handles; 700 701 // Support for stack overflow handling, get_thread, etc. 702 address _stack_base; 703 size_t _stack_size; 704 uintptr_t _self_raw_id; // used by get_thread (mutable) 705 int _lgrp_id; 706 707 volatile void** polling_page_addr() { return &_polling_page; } 708 709 public: 710 // Stack overflow support 711 address stack_base() const { assert(_stack_base != NULL,"Sanity check"); return _stack_base; } 712 void set_stack_base(address base) { _stack_base = base; } 713 size_t stack_size() const { return _stack_size; } 714 void set_stack_size(size_t size) { _stack_size = size; } 715 address stack_end() const { return stack_base() - stack_size(); } 716 void record_stack_base_and_size(); 717 void register_thread_stack_with_NMT() NOT_NMT_RETURN; 718 719 bool on_local_stack(address adr) const { 720 // QQQ this has knowledge of direction, ought to be a stack method 721 return (_stack_base >= adr && adr >= stack_end()); 722 } 723 724 uintptr_t self_raw_id() { return _self_raw_id; } 725 void set_self_raw_id(uintptr_t value) { _self_raw_id = value; } 726 727 int lgrp_id() const { return _lgrp_id; } 728 void set_lgrp_id(int value) { _lgrp_id = value; } 729 730 // Printing 731 void print_on(outputStream* st, bool print_extended_info) const; 732 virtual void print_on(outputStream* st) const { print_on(st, false); } 733 void print() const { print_on(tty); } 734 virtual void print_on_error(outputStream* st, char* buf, int buflen) const; 735 void print_value_on(outputStream* st) const; 736 737 // Debug-only code 738 #ifdef ASSERT 739 private: 740 // Deadlock detection support for Mutex locks. List of locks own by thread. 741 Monitor* _owned_locks; 742 // Mutex::set_owner_implementation is the only place where _owned_locks is modified, 743 // thus the friendship 744 friend class Mutex; 745 friend class Monitor; 746 747 public: 748 void print_owned_locks_on(outputStream* st) const; 749 void print_owned_locks() const { print_owned_locks_on(tty); } 750 Monitor* owned_locks() const { return _owned_locks; } 751 bool owns_locks() const { return owned_locks() != NULL; } 752 bool owns_locks_but_compiled_lock() const; 753 754 // Deadlock detection 755 bool allow_allocation() { return _allow_allocation_count == 0; } 756 ResourceMark* current_resource_mark() { return _current_resource_mark; } 757 void set_current_resource_mark(ResourceMark* rm) { _current_resource_mark = rm; } 758 #endif 759 760 void check_for_valid_safepoint_state(bool potential_vm_operation) PRODUCT_RETURN; 761 762 private: 763 volatile int _jvmti_env_iteration_count; 764 765 public: 766 void entering_jvmti_env_iteration() { ++_jvmti_env_iteration_count; } 767 void leaving_jvmti_env_iteration() { --_jvmti_env_iteration_count; } 768 bool is_inside_jvmti_env_iteration() { return _jvmti_env_iteration_count > 0; } 769 770 // Code generation 771 static ByteSize exception_file_offset() { return byte_offset_of(Thread, _exception_file); } 772 static ByteSize exception_line_offset() { return byte_offset_of(Thread, _exception_line); } 773 static ByteSize active_handles_offset() { return byte_offset_of(Thread, _active_handles); } 774 775 static ByteSize stack_base_offset() { return byte_offset_of(Thread, _stack_base); } 776 static ByteSize stack_size_offset() { return byte_offset_of(Thread, _stack_size); } 777 778 static ByteSize polling_page_offset() { return byte_offset_of(Thread, _polling_page); } 779 780 static ByteSize tlab_start_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::start_offset(); } 781 static ByteSize tlab_end_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::end_offset(); } 782 static ByteSize tlab_top_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::top_offset(); } 783 static ByteSize tlab_pf_top_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::pf_top_offset(); } 784 785 static ByteSize allocated_bytes_offset() { return byte_offset_of(Thread, _allocated_bytes); } 786 787 JFR_ONLY(DEFINE_THREAD_LOCAL_OFFSET_JFR;) 788 789 public: 790 volatile intptr_t _Stalled; 791 volatile int _TypeTag; 792 ParkEvent * _ParkEvent; // for synchronized() 793 ParkEvent * _SleepEvent; // for Thread.sleep 794 ParkEvent * _MuxEvent; // for low-level muxAcquire-muxRelease 795 int NativeSyncRecursion; // diagnostic 796 797 volatile int _OnTrap; // Resume-at IP delta 798 jint _hashStateW; // Marsaglia Shift-XOR thread-local RNG 799 jint _hashStateX; // thread-specific hashCode generator state 800 jint _hashStateY; 801 jint _hashStateZ; 802 803 // Low-level leaf-lock primitives used to implement synchronization 804 // and native monitor-mutex infrastructure. 805 // Not for general synchronization use. 806 static void SpinAcquire(volatile int * Lock, const char * Name); 807 static void SpinRelease(volatile int * Lock); 808 static void muxAcquire(volatile intptr_t * Lock, const char * Name); 809 static void muxAcquireW(volatile intptr_t * Lock, ParkEvent * ev); 810 static void muxRelease(volatile intptr_t * Lock); 811 }; 812 813 // Inline implementation of Thread::current() 814 inline Thread* Thread::current() { 815 Thread* current = current_or_null(); 816 assert(current != NULL, "Thread::current() called on detached thread"); 817 return current; 818 } 819 820 inline Thread* Thread::current_or_null() { 821 #ifndef USE_LIBRARY_BASED_TLS_ONLY 822 return _thr_current; 823 #else 824 if (ThreadLocalStorage::is_initialized()) { 825 return ThreadLocalStorage::thread(); 826 } 827 return NULL; 828 #endif 829 } 830 831 inline Thread* Thread::current_or_null_safe() { 832 if (ThreadLocalStorage::is_initialized()) { 833 return ThreadLocalStorage::thread(); 834 } 835 return NULL; 836 } 837 838 class NonJavaThread: public Thread { 839 friend class VMStructs; 840 841 NonJavaThread* volatile _next; 842 843 class List; 844 static List _the_list; 845 846 void add_to_the_list(); 847 void remove_from_the_list(); 848 849 protected: 850 virtual void pre_run(); 851 virtual void post_run(); 852 853 public: 854 NonJavaThread(); 855 ~NonJavaThread(); 856 857 class Iterator; 858 }; 859 860 // Provides iteration over the list of NonJavaThreads. 861 // List addition occurs in pre_run(), and removal occurs in post_run(), 862 // so that only live fully-initialized threads can be found in the list. 863 // Threads created after an iterator is constructed will not be visited 864 // by the iterator. The scope of an iterator is a critical section; there 865 // must be no safepoint checks in that scope. 866 class NonJavaThread::Iterator : public StackObj { 867 uint _protect_enter; 868 NonJavaThread* _current; 869 870 // Noncopyable. 871 Iterator(const Iterator&); 872 Iterator& operator=(const Iterator&); 873 874 public: 875 Iterator(); 876 ~Iterator(); 877 878 bool end() const { return _current == NULL; } 879 NonJavaThread* current() const { return _current; } 880 void step(); 881 }; 882 883 // Name support for threads. non-JavaThread subclasses with multiple 884 // uniquely named instances should derive from this. 885 class NamedThread: public NonJavaThread { 886 friend class VMStructs; 887 enum { 888 max_name_len = 64 889 }; 890 private: 891 char* _name; 892 // log JavaThread being processed by oops_do 893 JavaThread* _processed_thread; 894 uint _gc_id; // The current GC id when a thread takes part in GC 895 896 public: 897 NamedThread(); 898 ~NamedThread(); 899 // May only be called once per thread. 900 void set_name(const char* format, ...) ATTRIBUTE_PRINTF(2, 3); 901 virtual bool is_Named_thread() const { return true; } 902 virtual char* name() const { return _name == NULL ? (char*)"Unknown Thread" : _name; } 903 JavaThread *processed_thread() { return _processed_thread; } 904 void set_processed_thread(JavaThread *thread) { _processed_thread = thread; } 905 virtual void print_on(outputStream* st) const; 906 907 void set_gc_id(uint gc_id) { _gc_id = gc_id; } 908 uint gc_id() { return _gc_id; } 909 }; 910 911 // Worker threads are named and have an id of an assigned work. 912 class WorkerThread: public NamedThread { 913 private: 914 uint _id; 915 public: 916 WorkerThread() : _id(0) { } 917 virtual bool is_Worker_thread() const { return true; } 918 919 virtual WorkerThread* as_Worker_thread() const { 920 assert(is_Worker_thread(), "Dubious cast to WorkerThread*?"); 921 return (WorkerThread*) this; 922 } 923 924 void set_id(uint work_id) { _id = work_id; } 925 uint id() const { return _id; } 926 }; 927 928 // A single WatcherThread is used for simulating timer interrupts. 929 class WatcherThread: public NonJavaThread { 930 friend class VMStructs; 931 protected: 932 virtual void run(); 933 934 private: 935 static WatcherThread* _watcher_thread; 936 937 static bool _startable; 938 // volatile due to at least one lock-free read 939 volatile static bool _should_terminate; 940 public: 941 enum SomeConstants { 942 delay_interval = 10 // interrupt delay in milliseconds 943 }; 944 945 // Constructor 946 WatcherThread(); 947 948 // No destruction allowed 949 ~WatcherThread() { 950 guarantee(false, "WatcherThread deletion must fix the race with VM termination"); 951 } 952 953 // Tester 954 bool is_Watcher_thread() const { return true; } 955 956 // Printing 957 char* name() const { return (char*)"VM Periodic Task Thread"; } 958 void print_on(outputStream* st) const; 959 void unpark(); 960 961 // Returns the single instance of WatcherThread 962 static WatcherThread* watcher_thread() { return _watcher_thread; } 963 964 // Create and start the single instance of WatcherThread, or stop it on shutdown 965 static void start(); 966 static void stop(); 967 // Only allow start once the VM is sufficiently initialized 968 // Otherwise the first task to enroll will trigger the start 969 static void make_startable(); 970 private: 971 int sleep() const; 972 }; 973 974 975 class CompilerThread; 976 977 typedef void (*ThreadFunction)(JavaThread*, TRAPS); 978 979 class JavaThread: public Thread { 980 friend class VMStructs; 981 friend class JVMCIVMStructs; 982 friend class WhiteBox; 983 private: 984 JavaThread* _next; // The next thread in the Threads list 985 bool _on_thread_list; // Is set when this JavaThread is added to the Threads list 986 oop _threadObj; // The Java level thread object 987 988 #ifdef ASSERT 989 private: 990 int _java_call_counter; 991 992 public: 993 int java_call_counter() { return _java_call_counter; } 994 void inc_java_call_counter() { _java_call_counter++; } 995 void dec_java_call_counter() { 996 assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper"); 997 _java_call_counter--; 998 } 999 private: // restore original namespace restriction 1000 #endif // ifdef ASSERT 1001 1002 #ifndef PRODUCT 1003 public: 1004 enum { 1005 jump_ring_buffer_size = 16 1006 }; 1007 private: // restore original namespace restriction 1008 #endif 1009 1010 JavaFrameAnchor _anchor; // Encapsulation of current java frame and it state 1011 1012 ThreadFunction _entry_point; 1013 1014 JNIEnv _jni_environment; 1015 1016 // Deopt support 1017 DeoptResourceMark* _deopt_mark; // Holds special ResourceMark for deoptimization 1018 1019 intptr_t* _must_deopt_id; // id of frame that needs to be deopted once we 1020 // transition out of native 1021 CompiledMethod* _deopt_nmethod; // CompiledMethod that is currently being deoptimized 1022 vframeArray* _vframe_array_head; // Holds the heap of the active vframeArrays 1023 vframeArray* _vframe_array_last; // Holds last vFrameArray we popped 1024 // Because deoptimization is lazy we must save jvmti requests to set locals 1025 // in compiled frames until we deoptimize and we have an interpreter frame. 1026 // This holds the pointer to array (yeah like there might be more than one) of 1027 // description of compiled vframes that have locals that need to be updated. 1028 GrowableArray<jvmtiDeferredLocalVariableSet*>* _deferred_locals_updates; 1029 1030 // Handshake value for fixing 6243940. We need a place for the i2c 1031 // adapter to store the callee Method*. This value is NEVER live 1032 // across a gc point so it does NOT have to be gc'd 1033 // The handshake is open ended since we can't be certain that it will 1034 // be NULLed. This is because we rarely ever see the race and end up 1035 // in handle_wrong_method which is the backend of the handshake. See 1036 // code in i2c adapters and handle_wrong_method. 1037 1038 Method* _callee_target; 1039 1040 // Used to pass back results to the interpreter or generated code running Java code. 1041 oop _vm_result; // oop result is GC-preserved 1042 Metadata* _vm_result_2; // non-oop result 1043 1044 // See ReduceInitialCardMarks: this holds the precise space interval of 1045 // the most recent slow path allocation for which compiled code has 1046 // elided card-marks for performance along the fast-path. 1047 MemRegion _deferred_card_mark; 1048 1049 MonitorChunk* _monitor_chunks; // Contains the off stack monitors 1050 // allocated during deoptimization 1051 // and by JNI_MonitorEnter/Exit 1052 1053 // Async. requests support 1054 enum AsyncRequests { 1055 _no_async_condition = 0, 1056 _async_exception, 1057 _async_unsafe_access_error 1058 }; 1059 AsyncRequests _special_runtime_exit_condition; // Enum indicating pending async. request 1060 oop _pending_async_exception; 1061 1062 // Safepoint support 1063 public: // Expose _thread_state for SafeFetchInt() 1064 volatile JavaThreadState _thread_state; 1065 private: 1066 ThreadSafepointState* _safepoint_state; // Holds information about a thread during a safepoint 1067 address _saved_exception_pc; // Saved pc of instruction where last implicit exception happened 1068 1069 // JavaThread termination support 1070 enum TerminatedTypes { 1071 _not_terminated = 0xDEAD - 2, 1072 _thread_exiting, // JavaThread::exit() has been called for this thread 1073 _thread_terminated, // JavaThread is removed from thread list 1074 _vm_exited // JavaThread is still executing native code, but VM is terminated 1075 // only VM_Exit can set _vm_exited 1076 }; 1077 1078 // In general a JavaThread's _terminated field transitions as follows: 1079 // 1080 // _not_terminated => _thread_exiting => _thread_terminated 1081 // 1082 // _vm_exited is a special value to cover the case of a JavaThread 1083 // executing native code after the VM itself is terminated. 1084 volatile TerminatedTypes _terminated; 1085 // suspend/resume support 1086 volatile bool _suspend_equivalent; // Suspend equivalent condition 1087 jint _in_deopt_handler; // count of deoptimization 1088 // handlers thread is in 1089 volatile bool _doing_unsafe_access; // Thread may fault due to unsafe access 1090 bool _do_not_unlock_if_synchronized; // Do not unlock the receiver of a synchronized method (since it was 1091 // never locked) when throwing an exception. Used by interpreter only. 1092 1093 // JNI attach states: 1094 enum JNIAttachStates { 1095 _not_attaching_via_jni = 1, // thread is not attaching via JNI 1096 _attaching_via_jni, // thread is attaching via JNI 1097 _attached_via_jni // thread has attached via JNI 1098 }; 1099 1100 // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni. 1101 // A native thread that is attaching via JNI starts with a value 1102 // of _attaching_via_jni and transitions to _attached_via_jni. 1103 volatile JNIAttachStates _jni_attach_state; 1104 1105 public: 1106 // State of the stack guard pages for this thread. 1107 enum StackGuardState { 1108 stack_guard_unused, // not needed 1109 stack_guard_reserved_disabled, 1110 stack_guard_yellow_reserved_disabled,// disabled (temporarily) after stack overflow 1111 stack_guard_enabled // enabled 1112 }; 1113 1114 private: 1115 1116 #if INCLUDE_JVMCI 1117 // The _pending_* fields below are used to communicate extra information 1118 // from an uncommon trap in JVMCI compiled code to the uncommon trap handler. 1119 1120 // Communicates the DeoptReason and DeoptAction of the uncommon trap 1121 int _pending_deoptimization; 1122 1123 // Specifies whether the uncommon trap is to bci 0 of a synchronized method 1124 // before the monitor has been acquired. 1125 bool _pending_monitorenter; 1126 1127 // Specifies if the DeoptReason for the last uncommon trap was Reason_transfer_to_interpreter 1128 bool _pending_transfer_to_interpreter; 1129 1130 // Guard for re-entrant call to JVMCIRuntime::adjust_comp_level 1131 bool _adjusting_comp_level; 1132 1133 // True if in a runtime call from compiled code that will deoptimize 1134 // and re-execute a failed heap allocation in the interpreter. 1135 bool _in_retryable_allocation; 1136 1137 // An id of a speculation that JVMCI compiled code can use to further describe and 1138 // uniquely identify the speculative optimization guarded by the uncommon trap 1139 long _pending_failed_speculation; 1140 1141 // These fields are mutually exclusive in terms of live ranges. 1142 union { 1143 // Communicates the pc at which the most recent implicit exception occurred 1144 // from the signal handler to a deoptimization stub. 1145 address _implicit_exception_pc; 1146 1147 // Communicates an alternative call target to an i2c stub from a JavaCall . 1148 address _alternate_call_target; 1149 } _jvmci; 1150 1151 // Support for high precision, thread sensitive counters in JVMCI compiled code. 1152 jlong* _jvmci_counters; 1153 1154 public: 1155 static jlong* _jvmci_old_thread_counters; 1156 static void collect_counters(typeArrayOop array); 1157 private: 1158 #endif // INCLUDE_JVMCI 1159 1160 StackGuardState _stack_guard_state; 1161 1162 // Precompute the limit of the stack as used in stack overflow checks. 1163 // We load it from here to simplify the stack overflow check in assembly. 1164 address _stack_overflow_limit; 1165 address _reserved_stack_activation; 1166 1167 // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is 1168 // used to temp. parsing values into and out of the runtime system during exception handling for compiled 1169 // code) 1170 volatile oop _exception_oop; // Exception thrown in compiled code 1171 volatile address _exception_pc; // PC where exception happened 1172 volatile address _exception_handler_pc; // PC for handler of exception 1173 volatile int _is_method_handle_return; // true (== 1) if the current exception PC is a MethodHandle call site. 1174 1175 private: 1176 // support for JNI critical regions 1177 jint _jni_active_critical; // count of entries into JNI critical region 1178 1179 // Checked JNI: function name requires exception check 1180 char* _pending_jni_exception_check_fn; 1181 1182 // For deadlock detection. 1183 int _depth_first_number; 1184 1185 // JVMTI PopFrame support 1186 // This is set to popframe_pending to signal that top Java frame should be popped immediately 1187 int _popframe_condition; 1188 1189 // If reallocation of scalar replaced objects fails, we throw OOM 1190 // and during exception propagation, pop the top 1191 // _frames_to_pop_failed_realloc frames, the ones that reference 1192 // failed reallocations. 1193 int _frames_to_pop_failed_realloc; 1194 1195 #ifndef PRODUCT 1196 int _jmp_ring_index; 1197 struct { 1198 // We use intptr_t instead of address so debugger doesn't try and display strings 1199 intptr_t _target; 1200 intptr_t _instruction; 1201 const char* _file; 1202 int _line; 1203 } _jmp_ring[jump_ring_buffer_size]; 1204 #endif // PRODUCT 1205 1206 friend class VMThread; 1207 friend class ThreadWaitTransition; 1208 friend class VM_Exit; 1209 1210 void initialize(); // Initialized the instance variables 1211 1212 public: 1213 // Constructor 1214 JavaThread(bool is_attaching_via_jni = false); // for main thread and JNI attached threads 1215 JavaThread(ThreadFunction entry_point, size_t stack_size = 0); 1216 ~JavaThread(); 1217 1218 #ifdef ASSERT 1219 // verify this JavaThread hasn't be published in the Threads::list yet 1220 void verify_not_published(); 1221 #endif 1222 1223 //JNI functiontable getter/setter for JVMTI jni function table interception API. 1224 void set_jni_functions(struct JNINativeInterface_* functionTable) { 1225 _jni_environment.functions = functionTable; 1226 } 1227 struct JNINativeInterface_* get_jni_functions() { 1228 return (struct JNINativeInterface_ *)_jni_environment.functions; 1229 } 1230 1231 // This function is called at thread creation to allow 1232 // platform specific thread variables to be initialized. 1233 void cache_global_variables(); 1234 1235 // Executes Shutdown.shutdown() 1236 void invoke_shutdown_hooks(); 1237 1238 // Cleanup on thread exit 1239 enum ExitType { 1240 normal_exit, 1241 jni_detach 1242 }; 1243 void exit(bool destroy_vm, ExitType exit_type = normal_exit); 1244 1245 void cleanup_failed_attach_current_thread(); 1246 1247 // Testers 1248 virtual bool is_Java_thread() const { return true; } 1249 virtual bool can_call_java() const { return true; } 1250 1251 // Thread chain operations 1252 JavaThread* next() const { return _next; } 1253 void set_next(JavaThread* p) { _next = p; } 1254 1255 // Thread oop. threadObj() can be NULL for initial JavaThread 1256 // (or for threads attached via JNI) 1257 oop threadObj() const { return _threadObj; } 1258 void set_threadObj(oop p) { _threadObj = p; } 1259 1260 ThreadPriority java_priority() const; // Read from threadObj() 1261 1262 // Prepare thread and add to priority queue. If a priority is 1263 // not specified, use the priority of the thread object. Threads_lock 1264 // must be held while this function is called. 1265 void prepare(jobject jni_thread, ThreadPriority prio=NoPriority); 1266 1267 void set_saved_exception_pc(address pc) { _saved_exception_pc = pc; } 1268 address saved_exception_pc() { return _saved_exception_pc; } 1269 1270 1271 ThreadFunction entry_point() const { return _entry_point; } 1272 1273 // Allocates a new Java level thread object for this thread. thread_name may be NULL. 1274 void allocate_threadObj(Handle thread_group, const char* thread_name, bool daemon, TRAPS); 1275 1276 // Last frame anchor routines 1277 1278 JavaFrameAnchor* frame_anchor(void) { return &_anchor; } 1279 1280 // last_Java_sp 1281 bool has_last_Java_frame() const { return _anchor.has_last_Java_frame(); } 1282 intptr_t* last_Java_sp() const { return _anchor.last_Java_sp(); } 1283 1284 // last_Java_pc 1285 1286 address last_Java_pc(void) { return _anchor.last_Java_pc(); } 1287 1288 // Safepoint support 1289 inline JavaThreadState thread_state() const; 1290 inline void set_thread_state(JavaThreadState s); 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 MutexLockerEx 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 inline void set_deopt_suspend(); 1408 inline void clear_deopt_suspend(); 1409 bool is_deopt_suspend() { return (_suspend_flags & _deopt_suspend) != 0; } 1410 1411 bool is_external_suspend() const { 1412 return (_suspend_flags & _external_suspend) != 0; 1413 } 1414 // Whenever a thread transitions from native to vm/java it must suspend 1415 // if external|deopt suspend is present. 1416 bool is_suspend_after_native() const { 1417 return (_suspend_flags & (_external_suspend | _deopt_suspend)) != 0; 1418 } 1419 1420 // external suspend request is completed 1421 bool is_ext_suspended() const { 1422 return (_suspend_flags & _ext_suspended) != 0; 1423 } 1424 1425 bool is_external_suspend_with_lock() const { 1426 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag); 1427 return is_external_suspend(); 1428 } 1429 1430 // Special method to handle a pending external suspend request 1431 // when a suspend equivalent condition lifts. 1432 bool handle_special_suspend_equivalent_condition() { 1433 assert(is_suspend_equivalent(), 1434 "should only be called in a suspend equivalence condition"); 1435 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag); 1436 bool ret = is_external_suspend(); 1437 if (!ret) { 1438 // not about to self-suspend so clear suspend equivalence 1439 clear_suspend_equivalent(); 1440 } 1441 // implied else: 1442 // We have a pending external suspend request so we leave the 1443 // suspend_equivalent flag set until java_suspend_self() sets 1444 // the ext_suspended flag and clears the suspend_equivalent 1445 // flag. This insures that wait_for_ext_suspend_completion() 1446 // will return consistent values. 1447 return ret; 1448 } 1449 1450 // utility methods to see if we are doing some kind of suspension 1451 bool is_being_ext_suspended() const { 1452 MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag); 1453 return is_ext_suspended() || is_external_suspend(); 1454 } 1455 1456 bool is_suspend_equivalent() const { return _suspend_equivalent; } 1457 1458 void set_suspend_equivalent() { _suspend_equivalent = true; } 1459 void clear_suspend_equivalent() { _suspend_equivalent = false; } 1460 1461 // Thread.stop support 1462 void send_thread_stop(oop throwable); 1463 AsyncRequests clear_special_runtime_exit_condition() { 1464 AsyncRequests x = _special_runtime_exit_condition; 1465 _special_runtime_exit_condition = _no_async_condition; 1466 return x; 1467 } 1468 1469 // Are any async conditions present? 1470 bool has_async_condition() { return (_special_runtime_exit_condition != _no_async_condition); } 1471 1472 void check_and_handle_async_exceptions(bool check_unsafe_error = true); 1473 1474 // these next two are also used for self-suspension and async exception support 1475 void handle_special_runtime_exit_condition(bool check_asyncs = true); 1476 1477 // Return true if JavaThread has an asynchronous condition or 1478 // if external suspension is requested. 1479 bool has_special_runtime_exit_condition() { 1480 // Because we don't use is_external_suspend_with_lock 1481 // it is possible that we won't see an asynchronous external suspend 1482 // request that has just gotten started, i.e., SR_lock grabbed but 1483 // _external_suspend field change either not made yet or not visible 1484 // yet. However, this is okay because the request is asynchronous and 1485 // we will see the new flag value the next time through. It's also 1486 // possible that the external suspend request is dropped after 1487 // we have checked is_external_suspend(), we will recheck its value 1488 // under SR_lock in java_suspend_self(). 1489 return (_special_runtime_exit_condition != _no_async_condition) || 1490 is_external_suspend() || is_trace_suspend(); 1491 } 1492 1493 void set_pending_unsafe_access_error() { _special_runtime_exit_condition = _async_unsafe_access_error; } 1494 1495 inline void set_pending_async_exception(oop e); 1496 1497 // Fast-locking support 1498 bool is_lock_owned(address adr) const; 1499 1500 // Accessors for vframe array top 1501 // The linked list of vframe arrays are sorted on sp. This means when we 1502 // unpack the head must contain the vframe array to unpack. 1503 void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; } 1504 vframeArray* vframe_array_head() const { return _vframe_array_head; } 1505 1506 // Side structure for deferring update of java frame locals until deopt occurs 1507 GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred_locals() const { return _deferred_locals_updates; } 1508 void set_deferred_locals(GrowableArray<jvmtiDeferredLocalVariableSet *>* vf) { _deferred_locals_updates = vf; } 1509 1510 // These only really exist to make debugging deopt problems simpler 1511 1512 void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; } 1513 vframeArray* vframe_array_last() const { return _vframe_array_last; } 1514 1515 // The special resourceMark used during deoptimization 1516 1517 void set_deopt_mark(DeoptResourceMark* value) { _deopt_mark = value; } 1518 DeoptResourceMark* deopt_mark(void) { return _deopt_mark; } 1519 1520 intptr_t* must_deopt_id() { return _must_deopt_id; } 1521 void set_must_deopt_id(intptr_t* id) { _must_deopt_id = id; } 1522 void clear_must_deopt_id() { _must_deopt_id = NULL; } 1523 1524 void set_deopt_compiled_method(CompiledMethod* nm) { _deopt_nmethod = nm; } 1525 CompiledMethod* deopt_compiled_method() { return _deopt_nmethod; } 1526 1527 Method* callee_target() const { return _callee_target; } 1528 void set_callee_target (Method* x) { _callee_target = x; } 1529 1530 // Oop results of vm runtime calls 1531 oop vm_result() const { return _vm_result; } 1532 void set_vm_result (oop x) { _vm_result = x; } 1533 1534 Metadata* vm_result_2() const { return _vm_result_2; } 1535 void set_vm_result_2 (Metadata* x) { _vm_result_2 = x; } 1536 1537 MemRegion deferred_card_mark() const { return _deferred_card_mark; } 1538 void set_deferred_card_mark(MemRegion mr) { _deferred_card_mark = mr; } 1539 1540 #if INCLUDE_JVMCI 1541 int pending_deoptimization() const { return _pending_deoptimization; } 1542 long pending_failed_speculation() const { return _pending_failed_speculation; } 1543 bool adjusting_comp_level() const { return _adjusting_comp_level; } 1544 void set_adjusting_comp_level(bool b) { _adjusting_comp_level = b; } 1545 bool has_pending_monitorenter() const { return _pending_monitorenter; } 1546 void set_pending_monitorenter(bool b) { _pending_monitorenter = b; } 1547 void set_pending_deoptimization(int reason) { _pending_deoptimization = reason; } 1548 void set_pending_failed_speculation(long failed_speculation) { _pending_failed_speculation = failed_speculation; } 1549 void set_pending_transfer_to_interpreter(bool b) { _pending_transfer_to_interpreter = b; } 1550 void set_jvmci_alternate_call_target(address a) { assert(_jvmci._alternate_call_target == NULL, "must be"); _jvmci._alternate_call_target = a; } 1551 void set_jvmci_implicit_exception_pc(address a) { assert(_jvmci._implicit_exception_pc == NULL, "must be"); _jvmci._implicit_exception_pc = a; } 1552 1553 virtual bool in_retryable_allocation() const { return _in_retryable_allocation; } 1554 void set_in_retryable_allocation(bool b) { _in_retryable_allocation = b; } 1555 #endif // INCLUDE_JVMCI 1556 1557 // Exception handling for compiled methods 1558 oop exception_oop() const { return _exception_oop; } 1559 address exception_pc() const { return _exception_pc; } 1560 address exception_handler_pc() const { return _exception_handler_pc; } 1561 bool is_method_handle_return() const { return _is_method_handle_return == 1; } 1562 1563 void set_exception_oop(oop o) { (void)const_cast<oop&>(_exception_oop = o); } 1564 void set_exception_pc(address a) { _exception_pc = a; } 1565 void set_exception_handler_pc(address a) { _exception_handler_pc = a; } 1566 void set_is_method_handle_return(bool value) { _is_method_handle_return = value ? 1 : 0; } 1567 1568 void clear_exception_oop_and_pc() { 1569 set_exception_oop(NULL); 1570 set_exception_pc(NULL); 1571 } 1572 1573 // Stack overflow support 1574 // 1575 // (small addresses) 1576 // 1577 // -- <-- stack_end() --- 1578 // | | 1579 // | red pages | 1580 // | | 1581 // -- <-- stack_red_zone_base() | 1582 // | | 1583 // | guard 1584 // | yellow pages zone 1585 // | | 1586 // | | 1587 // -- <-- stack_yellow_zone_base() | 1588 // | | 1589 // | | 1590 // | reserved pages | 1591 // | | 1592 // -- <-- stack_reserved_zone_base() --- --- 1593 // /|\ shadow <-- stack_overflow_limit() (somewhere in here) 1594 // | zone 1595 // \|/ size 1596 // some untouched memory --- 1597 // 1598 // 1599 // -- 1600 // | 1601 // | shadow zone 1602 // | 1603 // -- 1604 // x frame n 1605 // -- 1606 // x frame n-1 1607 // x 1608 // -- 1609 // ... 1610 // 1611 // -- 1612 // x frame 0 1613 // -- <-- stack_base() 1614 // 1615 // (large addresses) 1616 // 1617 1618 private: 1619 // These values are derived from flags StackRedPages, StackYellowPages, 1620 // StackReservedPages and StackShadowPages. The zone size is determined 1621 // ergonomically if page_size > 4K. 1622 static size_t _stack_red_zone_size; 1623 static size_t _stack_yellow_zone_size; 1624 static size_t _stack_reserved_zone_size; 1625 static size_t _stack_shadow_zone_size; 1626 public: 1627 inline size_t stack_available(address cur_sp); 1628 1629 static size_t stack_red_zone_size() { 1630 assert(_stack_red_zone_size > 0, "Don't call this before the field is initialized."); 1631 return _stack_red_zone_size; 1632 } 1633 static void set_stack_red_zone_size(size_t s) { 1634 assert(is_aligned(s, os::vm_page_size()), 1635 "We can not protect if the red zone size is not page aligned."); 1636 assert(_stack_red_zone_size == 0, "This should be called only once."); 1637 _stack_red_zone_size = s; 1638 } 1639 address stack_red_zone_base() { 1640 return (address)(stack_end() + stack_red_zone_size()); 1641 } 1642 bool in_stack_red_zone(address a) { 1643 return a <= stack_red_zone_base() && a >= stack_end(); 1644 } 1645 1646 static size_t stack_yellow_zone_size() { 1647 assert(_stack_yellow_zone_size > 0, "Don't call this before the field is initialized."); 1648 return _stack_yellow_zone_size; 1649 } 1650 static void set_stack_yellow_zone_size(size_t s) { 1651 assert(is_aligned(s, os::vm_page_size()), 1652 "We can not protect if the yellow zone size is not page aligned."); 1653 assert(_stack_yellow_zone_size == 0, "This should be called only once."); 1654 _stack_yellow_zone_size = s; 1655 } 1656 1657 static size_t stack_reserved_zone_size() { 1658 // _stack_reserved_zone_size may be 0. This indicates the feature is off. 1659 return _stack_reserved_zone_size; 1660 } 1661 static void set_stack_reserved_zone_size(size_t s) { 1662 assert(is_aligned(s, os::vm_page_size()), 1663 "We can not protect if the reserved zone size is not page aligned."); 1664 assert(_stack_reserved_zone_size == 0, "This should be called only once."); 1665 _stack_reserved_zone_size = s; 1666 } 1667 address stack_reserved_zone_base() { 1668 return (address)(stack_end() + 1669 (stack_red_zone_size() + stack_yellow_zone_size() + stack_reserved_zone_size())); 1670 } 1671 bool in_stack_reserved_zone(address a) { 1672 return (a <= stack_reserved_zone_base()) && 1673 (a >= (address)((intptr_t)stack_reserved_zone_base() - stack_reserved_zone_size())); 1674 } 1675 1676 static size_t stack_yellow_reserved_zone_size() { 1677 return _stack_yellow_zone_size + _stack_reserved_zone_size; 1678 } 1679 bool in_stack_yellow_reserved_zone(address a) { 1680 return (a <= stack_reserved_zone_base()) && (a >= stack_red_zone_base()); 1681 } 1682 1683 // Size of red + yellow + reserved zones. 1684 static size_t stack_guard_zone_size() { 1685 return stack_red_zone_size() + stack_yellow_reserved_zone_size(); 1686 } 1687 1688 static size_t stack_shadow_zone_size() { 1689 assert(_stack_shadow_zone_size > 0, "Don't call this before the field is initialized."); 1690 return _stack_shadow_zone_size; 1691 } 1692 static void set_stack_shadow_zone_size(size_t s) { 1693 // The shadow area is not allocated or protected, so 1694 // it needs not be page aligned. 1695 // But the stack bang currently assumes that it is a 1696 // multiple of page size. This guarantees that the bang 1697 // loop touches all pages in the shadow zone. 1698 // This can be guaranteed differently, as well. E.g., if 1699 // the page size is a multiple of 4K, banging in 4K steps 1700 // suffices to touch all pages. (Some pages are banged 1701 // several times, though.) 1702 assert(is_aligned(s, os::vm_page_size()), 1703 "Stack bang assumes multiple of page size."); 1704 assert(_stack_shadow_zone_size == 0, "This should be called only once."); 1705 _stack_shadow_zone_size = s; 1706 } 1707 1708 void create_stack_guard_pages(); 1709 void remove_stack_guard_pages(); 1710 1711 void enable_stack_reserved_zone(); 1712 void disable_stack_reserved_zone(); 1713 void enable_stack_yellow_reserved_zone(); 1714 void disable_stack_yellow_reserved_zone(); 1715 void enable_stack_red_zone(); 1716 void disable_stack_red_zone(); 1717 1718 inline bool stack_guard_zone_unused(); 1719 inline bool stack_yellow_reserved_zone_disabled(); 1720 inline bool stack_reserved_zone_disabled(); 1721 inline bool stack_guards_enabled(); 1722 1723 address reserved_stack_activation() const { return _reserved_stack_activation; } 1724 void set_reserved_stack_activation(address addr) { 1725 assert(_reserved_stack_activation == stack_base() 1726 || _reserved_stack_activation == NULL 1727 || addr == stack_base(), "Must not be set twice"); 1728 _reserved_stack_activation = addr; 1729 } 1730 1731 // Attempt to reguard the stack after a stack overflow may have occurred. 1732 // Returns true if (a) guard pages are not needed on this thread, (b) the 1733 // pages are already guarded, or (c) the pages were successfully reguarded. 1734 // Returns false if there is not enough stack space to reguard the pages, in 1735 // which case the caller should unwind a frame and try again. The argument 1736 // should be the caller's (approximate) sp. 1737 bool reguard_stack(address cur_sp); 1738 // Similar to above but see if current stackpoint is out of the guard area 1739 // and reguard if possible. 1740 bool reguard_stack(void); 1741 1742 address stack_overflow_limit() { return _stack_overflow_limit; } 1743 void set_stack_overflow_limit() { 1744 _stack_overflow_limit = 1745 stack_end() + MAX2(JavaThread::stack_guard_zone_size(), JavaThread::stack_shadow_zone_size()); 1746 } 1747 1748 // Misc. accessors/mutators 1749 void set_do_not_unlock(void) { _do_not_unlock_if_synchronized = true; } 1750 void clr_do_not_unlock(void) { _do_not_unlock_if_synchronized = false; } 1751 bool do_not_unlock(void) { return _do_not_unlock_if_synchronized; } 1752 1753 #ifndef PRODUCT 1754 void record_jump(address target, address instr, const char* file, int line); 1755 #endif // PRODUCT 1756 1757 // For assembly stub generation 1758 static ByteSize threadObj_offset() { return byte_offset_of(JavaThread, _threadObj); } 1759 #ifndef PRODUCT 1760 static ByteSize jmp_ring_index_offset() { return byte_offset_of(JavaThread, _jmp_ring_index); } 1761 static ByteSize jmp_ring_offset() { return byte_offset_of(JavaThread, _jmp_ring); } 1762 #endif // PRODUCT 1763 static ByteSize jni_environment_offset() { return byte_offset_of(JavaThread, _jni_environment); } 1764 static ByteSize pending_jni_exception_check_fn_offset() { 1765 return byte_offset_of(JavaThread, _pending_jni_exception_check_fn); 1766 } 1767 static ByteSize last_Java_sp_offset() { 1768 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset(); 1769 } 1770 static ByteSize last_Java_pc_offset() { 1771 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset(); 1772 } 1773 static ByteSize frame_anchor_offset() { 1774 return byte_offset_of(JavaThread, _anchor); 1775 } 1776 static ByteSize callee_target_offset() { return byte_offset_of(JavaThread, _callee_target); } 1777 static ByteSize vm_result_offset() { return byte_offset_of(JavaThread, _vm_result); } 1778 static ByteSize vm_result_2_offset() { return byte_offset_of(JavaThread, _vm_result_2); } 1779 static ByteSize thread_state_offset() { return byte_offset_of(JavaThread, _thread_state); } 1780 static ByteSize saved_exception_pc_offset() { return byte_offset_of(JavaThread, _saved_exception_pc); } 1781 static ByteSize osthread_offset() { return byte_offset_of(JavaThread, _osthread); } 1782 #if INCLUDE_JVMCI 1783 static ByteSize pending_deoptimization_offset() { return byte_offset_of(JavaThread, _pending_deoptimization); } 1784 static ByteSize pending_monitorenter_offset() { return byte_offset_of(JavaThread, _pending_monitorenter); } 1785 static ByteSize pending_failed_speculation_offset() { return byte_offset_of(JavaThread, _pending_failed_speculation); } 1786 static ByteSize jvmci_alternate_call_target_offset() { return byte_offset_of(JavaThread, _jvmci._alternate_call_target); } 1787 static ByteSize jvmci_implicit_exception_pc_offset() { return byte_offset_of(JavaThread, _jvmci._implicit_exception_pc); } 1788 static ByteSize jvmci_counters_offset() { return byte_offset_of(JavaThread, _jvmci_counters); } 1789 #endif // INCLUDE_JVMCI 1790 static ByteSize exception_oop_offset() { return byte_offset_of(JavaThread, _exception_oop); } 1791 static ByteSize exception_pc_offset() { return byte_offset_of(JavaThread, _exception_pc); } 1792 static ByteSize exception_handler_pc_offset() { return byte_offset_of(JavaThread, _exception_handler_pc); } 1793 static ByteSize stack_overflow_limit_offset() { return byte_offset_of(JavaThread, _stack_overflow_limit); } 1794 static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); } 1795 static ByteSize stack_guard_state_offset() { return byte_offset_of(JavaThread, _stack_guard_state); } 1796 static ByteSize reserved_stack_activation_offset() { return byte_offset_of(JavaThread, _reserved_stack_activation); } 1797 static ByteSize suspend_flags_offset() { return byte_offset_of(JavaThread, _suspend_flags); } 1798 1799 static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); } 1800 static ByteSize should_post_on_exceptions_flag_offset() { 1801 return byte_offset_of(JavaThread, _should_post_on_exceptions_flag); 1802 } 1803 1804 // Returns the jni environment for this thread 1805 JNIEnv* jni_environment() { return &_jni_environment; } 1806 1807 static JavaThread* thread_from_jni_environment(JNIEnv* env) { 1808 JavaThread *thread_from_jni_env = (JavaThread*)((intptr_t)env - in_bytes(jni_environment_offset())); 1809 // Only return NULL if thread is off the thread list; starting to 1810 // exit should not return NULL. 1811 if (thread_from_jni_env->is_terminated()) { 1812 thread_from_jni_env->block_if_vm_exited(); 1813 return NULL; 1814 } else { 1815 return thread_from_jni_env; 1816 } 1817 } 1818 1819 // JNI critical regions. These can nest. 1820 bool in_critical() { return _jni_active_critical > 0; } 1821 bool in_last_critical() { return _jni_active_critical == 1; } 1822 inline void enter_critical(); 1823 void exit_critical() { 1824 assert(Thread::current() == this, "this must be current thread"); 1825 _jni_active_critical--; 1826 assert(_jni_active_critical >= 0, "JNI critical nesting problem?"); 1827 } 1828 1829 // Checked JNI: is the programmer required to check for exceptions, if so specify 1830 // which function name. Returning to a Java frame should implicitly clear the 1831 // pending check, this is done for Native->Java transitions (i.e. user JNI code). 1832 // VM->Java transistions are not cleared, it is expected that JNI code enclosed 1833 // within ThreadToNativeFromVM makes proper exception checks (i.e. VM internal). 1834 bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != NULL; } 1835 void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = NULL; } 1836 const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; } 1837 void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; } 1838 1839 // For deadlock detection 1840 int depth_first_number() { return _depth_first_number; } 1841 void set_depth_first_number(int dfn) { _depth_first_number = dfn; } 1842 1843 private: 1844 void set_monitor_chunks(MonitorChunk* monitor_chunks) { _monitor_chunks = monitor_chunks; } 1845 1846 public: 1847 MonitorChunk* monitor_chunks() const { return _monitor_chunks; } 1848 void add_monitor_chunk(MonitorChunk* chunk); 1849 void remove_monitor_chunk(MonitorChunk* chunk); 1850 bool in_deopt_handler() const { return _in_deopt_handler > 0; } 1851 void inc_in_deopt_handler() { _in_deopt_handler++; } 1852 void dec_in_deopt_handler() { 1853 assert(_in_deopt_handler > 0, "mismatched deopt nesting"); 1854 if (_in_deopt_handler > 0) { // robustness 1855 _in_deopt_handler--; 1856 } 1857 } 1858 1859 private: 1860 void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; } 1861 1862 public: 1863 1864 // Frame iteration; calls the function f for all frames on the stack 1865 void frames_do(void f(frame*, const RegisterMap*)); 1866 1867 // Memory operations 1868 void oops_do(OopClosure* f, CodeBlobClosure* cf); 1869 1870 // Sweeper operations 1871 virtual void nmethods_do(CodeBlobClosure* cf); 1872 1873 // RedefineClasses Support 1874 void metadata_do(MetadataClosure* f); 1875 1876 // Debug method asserting thread states are correct during a handshake operation. 1877 DEBUG_ONLY(void verify_states_for_handshake();) 1878 1879 // Misc. operations 1880 char* name() const { return (char*)get_thread_name(); } 1881 void print_on(outputStream* st, bool print_extended_info) const; 1882 void print_on(outputStream* st) const { print_on(st, false); } 1883 void print_value(); 1884 void print_thread_state_on(outputStream*) const PRODUCT_RETURN; 1885 void print_thread_state() const PRODUCT_RETURN; 1886 void print_on_error(outputStream* st, char* buf, int buflen) const; 1887 void print_name_on_error(outputStream* st, char* buf, int buflen) const; 1888 void verify(); 1889 const char* get_thread_name() const; 1890 protected: 1891 // factor out low-level mechanics for use in both normal and error cases 1892 virtual const char* get_thread_name_string(char* buf = NULL, int buflen = 0) const; 1893 public: 1894 const char* get_threadgroup_name() const; 1895 const char* get_parent_name() const; 1896 1897 // Accessing frames 1898 frame last_frame() { 1899 _anchor.make_walkable(this); 1900 return pd_last_frame(); 1901 } 1902 javaVFrame* last_java_vframe(RegisterMap* reg_map); 1903 1904 // Returns method at 'depth' java or native frames down the stack 1905 // Used for security checks 1906 Klass* security_get_caller_class(int depth); 1907 1908 // Print stack trace in external format 1909 void print_stack_on(outputStream* st); 1910 void print_stack() { print_stack_on(tty); } 1911 1912 // Print stack traces in various internal formats 1913 void trace_stack() PRODUCT_RETURN; 1914 void trace_stack_from(vframe* start_vf) PRODUCT_RETURN; 1915 void trace_frames() PRODUCT_RETURN; 1916 void trace_oops() PRODUCT_RETURN; 1917 1918 // Print an annotated view of the stack frames 1919 void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN; 1920 void validate_frame_layout() { 1921 print_frame_layout(0, true); 1922 } 1923 1924 // Returns the number of stack frames on the stack 1925 int depth() const; 1926 1927 // Function for testing deoptimization 1928 void deoptimize(); 1929 void make_zombies(); 1930 1931 void deoptimized_wrt_marked_nmethods(); 1932 1933 public: 1934 // Returns the running thread as a JavaThread 1935 static inline JavaThread* current(); 1936 1937 // Returns the active Java thread. Do not use this if you know you are calling 1938 // from a JavaThread, as it's slower than JavaThread::current. If called from 1939 // the VMThread, it also returns the JavaThread that instigated the VMThread's 1940 // operation. You may not want that either. 1941 static JavaThread* active(); 1942 1943 inline CompilerThread* as_CompilerThread(); 1944 1945 protected: 1946 virtual void pre_run(); 1947 virtual void run(); 1948 void thread_main_inner(); 1949 virtual void post_run(); 1950 1951 1952 private: 1953 GrowableArray<oop>* _array_for_gc; 1954 public: 1955 1956 void register_array_for_gc(GrowableArray<oop>* array) { _array_for_gc = array; } 1957 1958 public: 1959 // Thread local information maintained by JVMTI. 1960 void set_jvmti_thread_state(JvmtiThreadState *value) { _jvmti_thread_state = value; } 1961 // A JvmtiThreadState is lazily allocated. This jvmti_thread_state() 1962 // getter is used to get this JavaThread's JvmtiThreadState if it has 1963 // one which means NULL can be returned. JvmtiThreadState::state_for() 1964 // is used to get the specified JavaThread's JvmtiThreadState if it has 1965 // one or it allocates a new JvmtiThreadState for the JavaThread and 1966 // returns it. JvmtiThreadState::state_for() will return NULL only if 1967 // the specified JavaThread is exiting. 1968 JvmtiThreadState *jvmti_thread_state() const { return _jvmti_thread_state; } 1969 static ByteSize jvmti_thread_state_offset() { return byte_offset_of(JavaThread, _jvmti_thread_state); } 1970 1971 // JVMTI PopFrame support 1972 // Setting and clearing popframe_condition 1973 // All of these enumerated values are bits. popframe_pending 1974 // indicates that a PopFrame() has been requested and not yet been 1975 // completed. popframe_processing indicates that that PopFrame() is in 1976 // the process of being completed. popframe_force_deopt_reexecution_bit 1977 // indicates that special handling is required when returning to a 1978 // deoptimized caller. 1979 enum PopCondition { 1980 popframe_inactive = 0x00, 1981 popframe_pending_bit = 0x01, 1982 popframe_processing_bit = 0x02, 1983 popframe_force_deopt_reexecution_bit = 0x04 1984 }; 1985 PopCondition popframe_condition() { return (PopCondition) _popframe_condition; } 1986 void set_popframe_condition(PopCondition c) { _popframe_condition = c; } 1987 void set_popframe_condition_bit(PopCondition c) { _popframe_condition |= c; } 1988 void clear_popframe_condition() { _popframe_condition = popframe_inactive; } 1989 static ByteSize popframe_condition_offset() { return byte_offset_of(JavaThread, _popframe_condition); } 1990 bool has_pending_popframe() { return (popframe_condition() & popframe_pending_bit) != 0; } 1991 bool popframe_forcing_deopt_reexecution() { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; } 1992 void clear_popframe_forcing_deopt_reexecution() { _popframe_condition &= ~popframe_force_deopt_reexecution_bit; } 1993 #ifdef CC_INTERP 1994 bool pop_frame_pending(void) { return ((_popframe_condition & popframe_pending_bit) != 0); } 1995 void clr_pop_frame_pending(void) { _popframe_condition = popframe_inactive; } 1996 bool pop_frame_in_process(void) { return ((_popframe_condition & popframe_processing_bit) != 0); } 1997 void set_pop_frame_in_process(void) { _popframe_condition |= popframe_processing_bit; } 1998 void clr_pop_frame_in_process(void) { _popframe_condition &= ~popframe_processing_bit; } 1999 #endif 2000 2001 int frames_to_pop_failed_realloc() const { return _frames_to_pop_failed_realloc; } 2002 void set_frames_to_pop_failed_realloc(int nb) { _frames_to_pop_failed_realloc = nb; } 2003 void dec_frames_to_pop_failed_realloc() { _frames_to_pop_failed_realloc--; } 2004 2005 private: 2006 // Saved incoming arguments to popped frame. 2007 // Used only when popped interpreted frame returns to deoptimized frame. 2008 void* _popframe_preserved_args; 2009 int _popframe_preserved_args_size; 2010 2011 public: 2012 void popframe_preserve_args(ByteSize size_in_bytes, void* start); 2013 void* popframe_preserved_args(); 2014 ByteSize popframe_preserved_args_size(); 2015 WordSize popframe_preserved_args_size_in_words(); 2016 void popframe_free_preserved_args(); 2017 2018 2019 private: 2020 JvmtiThreadState *_jvmti_thread_state; 2021 2022 // Used by the interpreter in fullspeed mode for frame pop, method 2023 // entry, method exit and single stepping support. This field is 2024 // only set to non-zero by the VM_EnterInterpOnlyMode VM operation. 2025 // It can be set to zero asynchronously (i.e., without a VM operation 2026 // or a lock) so we have to be very careful. 2027 int _interp_only_mode; 2028 2029 public: 2030 // used by the interpreter for fullspeed debugging support (see above) 2031 static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); } 2032 bool is_interp_only_mode() { return (_interp_only_mode != 0); } 2033 int get_interp_only_mode() { return _interp_only_mode; } 2034 void increment_interp_only_mode() { ++_interp_only_mode; } 2035 void decrement_interp_only_mode() { --_interp_only_mode; } 2036 2037 // support for cached flag that indicates whether exceptions need to be posted for this thread 2038 // if this is false, we can avoid deoptimizing when events are thrown 2039 // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything 2040 private: 2041 int _should_post_on_exceptions_flag; 2042 2043 public: 2044 int should_post_on_exceptions_flag() { return _should_post_on_exceptions_flag; } 2045 void set_should_post_on_exceptions_flag(int val) { _should_post_on_exceptions_flag = val; } 2046 2047 private: 2048 ThreadStatistics *_thread_stat; 2049 2050 public: 2051 ThreadStatistics* get_thread_stat() const { return _thread_stat; } 2052 2053 // Return a blocker object for which this thread is blocked parking. 2054 oop current_park_blocker(); 2055 2056 private: 2057 static size_t _stack_size_at_create; 2058 2059 public: 2060 static inline size_t stack_size_at_create(void) { 2061 return _stack_size_at_create; 2062 } 2063 static inline void set_stack_size_at_create(size_t value) { 2064 _stack_size_at_create = value; 2065 } 2066 2067 // Machine dependent stuff 2068 #include OS_CPU_HEADER(thread) 2069 2070 public: 2071 void set_blocked_on_compilation(bool value) { 2072 _blocked_on_compilation = value; 2073 } 2074 2075 bool blocked_on_compilation() { 2076 return _blocked_on_compilation; 2077 } 2078 protected: 2079 bool _blocked_on_compilation; 2080 2081 2082 // JSR166 per-thread parker 2083 private: 2084 Parker* _parker; 2085 public: 2086 Parker* parker() { return _parker; } 2087 2088 // Biased locking support 2089 private: 2090 GrowableArray<MonitorInfo*>* _cached_monitor_info; 2091 public: 2092 GrowableArray<MonitorInfo*>* cached_monitor_info() { return _cached_monitor_info; } 2093 void set_cached_monitor_info(GrowableArray<MonitorInfo*>* info) { _cached_monitor_info = info; } 2094 2095 // clearing/querying jni attach status 2096 bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; } 2097 bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; } 2098 inline void set_done_attaching_via_jni(); 2099 2100 // Stack dump assistance: 2101 // Track the class we want to initialize but for which we have to wait 2102 // on its init_lock() because it is already being initialized. 2103 void set_class_to_be_initialized(InstanceKlass* k); 2104 InstanceKlass* class_to_be_initialized() const; 2105 2106 private: 2107 InstanceKlass* _class_to_be_initialized; 2108 2109 }; 2110 2111 // Inline implementation of JavaThread::current 2112 inline JavaThread* JavaThread::current() { 2113 Thread* thread = Thread::current(); 2114 assert(thread->is_Java_thread(), "just checking"); 2115 return (JavaThread*)thread; 2116 } 2117 2118 inline CompilerThread* JavaThread::as_CompilerThread() { 2119 assert(is_Compiler_thread(), "just checking"); 2120 return (CompilerThread*)this; 2121 } 2122 2123 // Dedicated thread to sweep the code cache 2124 class CodeCacheSweeperThread : public JavaThread { 2125 CompiledMethod* _scanned_compiled_method; // nmethod being scanned by the sweeper 2126 public: 2127 CodeCacheSweeperThread(); 2128 // Track the nmethod currently being scanned by the sweeper 2129 void set_scanned_compiled_method(CompiledMethod* cm) { 2130 assert(_scanned_compiled_method == NULL || cm == NULL, "should reset to NULL before writing a new value"); 2131 _scanned_compiled_method = cm; 2132 } 2133 2134 // Hide sweeper thread from external view. 2135 bool is_hidden_from_external_view() const { return true; } 2136 2137 bool is_Code_cache_sweeper_thread() const { return true; } 2138 2139 // Prevent GC from unloading _scanned_compiled_method 2140 void oops_do(OopClosure* f, CodeBlobClosure* cf); 2141 void nmethods_do(CodeBlobClosure* cf); 2142 }; 2143 2144 // A thread used for Compilation. 2145 class CompilerThread : public JavaThread { 2146 friend class VMStructs; 2147 private: 2148 CompilerCounters* _counters; 2149 2150 ciEnv* _env; 2151 CompileLog* _log; 2152 CompileTask* volatile _task; // print_threads_compiling can read this concurrently. 2153 CompileQueue* _queue; 2154 BufferBlob* _buffer_blob; 2155 2156 AbstractCompiler* _compiler; 2157 TimeStamp _idle_time; 2158 2159 public: 2160 2161 static CompilerThread* current(); 2162 2163 CompilerThread(CompileQueue* queue, CompilerCounters* counters); 2164 ~CompilerThread(); 2165 2166 bool is_Compiler_thread() const { return true; } 2167 2168 virtual bool can_call_java() const; 2169 2170 // Hide native compiler threads from external view. 2171 bool is_hidden_from_external_view() const { return !can_call_java(); } 2172 2173 void set_compiler(AbstractCompiler* c) { _compiler = c; } 2174 AbstractCompiler* compiler() const { return _compiler; } 2175 2176 CompileQueue* queue() const { return _queue; } 2177 CompilerCounters* counters() const { return _counters; } 2178 2179 // Get/set the thread's compilation environment. 2180 ciEnv* env() { return _env; } 2181 void set_env(ciEnv* env) { _env = env; } 2182 2183 BufferBlob* get_buffer_blob() const { return _buffer_blob; } 2184 void set_buffer_blob(BufferBlob* b) { _buffer_blob = b; } 2185 2186 // Get/set the thread's logging information 2187 CompileLog* log() { return _log; } 2188 void init_log(CompileLog* log) { 2189 // Set once, for good. 2190 assert(_log == NULL, "set only once"); 2191 _log = log; 2192 } 2193 2194 void start_idle_timer() { _idle_time.update(); } 2195 jlong idle_time_millis() { 2196 return TimeHelper::counter_to_millis(_idle_time.ticks_since_update()); 2197 } 2198 2199 #ifndef PRODUCT 2200 private: 2201 IdealGraphPrinter *_ideal_graph_printer; 2202 public: 2203 IdealGraphPrinter *ideal_graph_printer() { return _ideal_graph_printer; } 2204 void set_ideal_graph_printer(IdealGraphPrinter *n) { _ideal_graph_printer = n; } 2205 #endif 2206 2207 // Get/set the thread's current task 2208 CompileTask* task() { return _task; } 2209 void set_task(CompileTask* task) { _task = task; } 2210 }; 2211 2212 inline CompilerThread* CompilerThread::current() { 2213 return JavaThread::current()->as_CompilerThread(); 2214 } 2215 2216 // The active thread queue. It also keeps track of the current used 2217 // thread priorities. 2218 class Threads: AllStatic { 2219 friend class VMStructs; 2220 private: 2221 static JavaThread* _thread_list; 2222 static int _number_of_threads; 2223 static int _number_of_non_daemon_threads; 2224 static int _return_code; 2225 static uintx _thread_claim_token; 2226 #ifdef ASSERT 2227 static bool _vm_complete; 2228 #endif 2229 2230 static void initialize_java_lang_classes(JavaThread* main_thread, TRAPS); 2231 static void initialize_jsr292_core_classes(TRAPS); 2232 2233 public: 2234 // Thread management 2235 // force_daemon is a concession to JNI, where we may need to add a 2236 // thread to the thread list before allocating its thread object 2237 static void add(JavaThread* p, bool force_daemon = false); 2238 static void remove(JavaThread* p); 2239 static void non_java_threads_do(ThreadClosure* tc); 2240 static void java_threads_do(ThreadClosure* tc); 2241 static void java_threads_and_vm_thread_do(ThreadClosure* tc); 2242 static void threads_do(ThreadClosure* tc); 2243 static void possibly_parallel_threads_do(bool is_par, ThreadClosure* tc); 2244 2245 // Initializes the vm and creates the vm thread 2246 static jint create_vm(JavaVMInitArgs* args, bool* canTryAgain); 2247 static void convert_vm_init_libraries_to_agents(); 2248 static void create_vm_init_libraries(); 2249 static void create_vm_init_agents(); 2250 static void shutdown_vm_agents(); 2251 static bool destroy_vm(); 2252 // Supported VM versions via JNI 2253 // Includes JNI_VERSION_1_1 2254 static jboolean is_supported_jni_version_including_1_1(jint version); 2255 // Does not include JNI_VERSION_1_1 2256 static jboolean is_supported_jni_version(jint version); 2257 2258 // The "thread claim token" provides a way for threads to be claimed 2259 // by parallel worker tasks. 2260 // 2261 // Each thread contains a "token" field. A task will claim the 2262 // thread only if its token is different from the global token, 2263 // which is updated by calling change_thread_claim_token(). When 2264 // a thread is claimed, it's token is set to the global token value 2265 // so other threads in the same iteration pass won't claim it. 2266 // 2267 // For this to work change_thread_claim_token() needs to be called 2268 // exactly once in sequential code before starting parallel tasks 2269 // that should claim threads. 2270 // 2271 // New threads get their token set to 0 and change_thread_claim_token() 2272 // never sets the global token to 0. 2273 static uintx thread_claim_token() { return _thread_claim_token; } 2274 static void change_thread_claim_token(); 2275 static void assert_all_threads_claimed() NOT_DEBUG_RETURN; 2276 2277 // Apply "f->do_oop" to all root oops in all threads. 2278 // This version may only be called by sequential code. 2279 static void oops_do(OopClosure* f, CodeBlobClosure* cf); 2280 // This version may be called by sequential or parallel code. 2281 static void possibly_parallel_oops_do(bool is_par, OopClosure* f, CodeBlobClosure* cf); 2282 2283 // Apply "f->do_oop" to roots in all threads that 2284 // are part of compiled frames 2285 static void compiled_frame_oops_do(OopClosure* f, CodeBlobClosure* cf); 2286 2287 static void convert_hcode_pointers(); 2288 static void restore_hcode_pointers(); 2289 2290 // Sweeper 2291 static void nmethods_do(CodeBlobClosure* cf); 2292 2293 // RedefineClasses support 2294 static void metadata_do(MetadataClosure* f); 2295 static void metadata_handles_do(void f(Metadata*)); 2296 2297 #ifdef ASSERT 2298 static bool is_vm_complete() { return _vm_complete; } 2299 #endif // ASSERT 2300 2301 // Verification 2302 static void verify(); 2303 static void print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks, bool print_extended_info); 2304 static void print(bool print_stacks, bool internal_format) { 2305 // this function is only used by debug.cpp 2306 print_on(tty, print_stacks, internal_format, false /* no concurrent lock printed */, false /* simple format */); 2307 } 2308 static void print_on_error(outputStream* st, Thread* current, char* buf, int buflen); 2309 static void print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf, 2310 int buflen, bool* found_current); 2311 static void print_threads_compiling(outputStream* st, char* buf, int buflen, bool short_form = false); 2312 2313 // Get Java threads that are waiting to enter a monitor. 2314 static GrowableArray<JavaThread*>* get_pending_threads(ThreadsList * t_list, 2315 int count, address monitor); 2316 2317 // Get owning Java thread from the monitor's owner field. 2318 static JavaThread *owning_thread_from_monitor_owner(ThreadsList * t_list, 2319 address owner); 2320 2321 // Number of threads on the active threads list 2322 static int number_of_threads() { return _number_of_threads; } 2323 // Number of non-daemon threads on the active threads list 2324 static int number_of_non_daemon_threads() { return _number_of_non_daemon_threads; } 2325 2326 // Deoptimizes all frames tied to marked nmethods 2327 static void deoptimized_wrt_marked_nmethods(); 2328 2329 struct Test; // For private gtest access. 2330 }; 2331 2332 2333 // Thread iterator 2334 class ThreadClosure: public StackObj { 2335 public: 2336 virtual void do_thread(Thread* thread) = 0; 2337 }; 2338 2339 class SignalHandlerMark: public StackObj { 2340 private: 2341 Thread* _thread; 2342 public: 2343 SignalHandlerMark(Thread* t) { 2344 _thread = t; 2345 if (_thread) _thread->enter_signal_handler(); 2346 } 2347 ~SignalHandlerMark() { 2348 if (_thread) _thread->leave_signal_handler(); 2349 _thread = NULL; 2350 } 2351 }; 2352 2353 2354 #endif // SHARE_RUNTIME_THREAD_HPP