1 /*
2 * Copyright (c) 1997, 2020, 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/globalDefinitions.hpp"
52 #include "utilities/macros.hpp"
53 #ifdef ZERO
54 # include "stack_zero.hpp"
55 #endif
56 #if INCLUDE_JFR
57 #include "jfr/support/jfrThreadExtension.hpp"
58 #endif
59
60
61 class SafeThreadsListPtr;
62 class ThreadSafepointState;
63 class ThreadsList;
64 class ThreadsSMRSupport;
65
66 class JvmtiRawMonitor;
67 class JvmtiThreadState;
68 class ThreadStatistics;
69 class ConcurrentLocksDump;
70 class ParkEvent;
71 class Parker;
72 class MonitorInfo;
73
74 class ciEnv;
75 class CompileThread;
76 class CompileLog;
77 class CompileTask;
78 class CompileQueue;
79 class CompilerCounters;
80
81 class vframeArray;
82 class vframe;
83 class javaVFrame;
84
85 class DeoptResourceMark;
86 class jvmtiDeferredLocalVariableSet;
87
88 class ThreadClosure;
89 class ICRefillVerifier;
90 class IdealGraphPrinter;
91
92 class JVMCIEnv;
93 class JVMCIPrimitiveArray;
94
95 class Metadata;
96 class ResourceArea;
97
98 DEBUG_ONLY(class ResourceMark;)
99
100 class WorkerThread;
101
102 // Class hierarchy
103 // - Thread
104 // - JavaThread
105 // - various subclasses eg CompilerThread, ServiceThread
106 // - NonJavaThread
107 // - NamedThread
108 // - VMThread
109 // - ConcurrentGCThread
110 // - WorkerThread
111 // - GangWorker
112 // - WatcherThread
113 // - JfrThreadSampler
114 //
115 // All Thread subclasses must be either JavaThread or NonJavaThread.
116 // This means !t->is_Java_thread() iff t is a NonJavaThread, or t is
117 // a partially constructed/destroyed Thread.
118
119 // Thread execution sequence and actions:
120 // All threads:
121 // - thread_native_entry // per-OS native entry point
122 // - stack initialization
123 // - other OS-level initialization (signal masks etc)
124 // - handshake with creating thread (if not started suspended)
125 // - this->call_run() // common shared entry point
126 // - shared common initialization
127 // - this->pre_run() // virtual per-thread-type initialization
128 // - this->run() // virtual per-thread-type "main" logic
129 // - shared common tear-down
130 // - this->post_run() // virtual per-thread-type tear-down
131 // - // 'this' no longer referenceable
132 // - OS-level tear-down (minimal)
133 // - final logging
134 //
135 // For JavaThread:
136 // - this->run() // virtual but not normally overridden
137 // - this->thread_main_inner() // extra call level to ensure correct stack calculations
138 // - this->entry_point() // set differently for each kind of JavaThread
139
140 class Thread: public ThreadShadow {
141 friend class VMStructs;
142 friend class JVMCIVMStructs;
143 private:
144
145 #ifndef USE_LIBRARY_BASED_TLS_ONLY
146 // Current thread is maintained as a thread-local variable
147 static THREAD_LOCAL Thread* _thr_current;
148 #endif
149
150 // Thread local data area available to the GC. The internal
151 // structure and contents of this data area is GC-specific.
152 // Only GC and GC barrier code should access this data area.
153 GCThreadLocalData _gc_data;
154
155 public:
156 static ByteSize gc_data_offset() {
157 return byte_offset_of(Thread, _gc_data);
158 }
159
160 template <typename T> T* gc_data() {
161 STATIC_ASSERT(sizeof(T) <= sizeof(_gc_data));
162 return reinterpret_cast<T*>(&_gc_data);
163 }
164
165 // Exception handling
166 // (Note: _pending_exception and friends are in ThreadShadow)
167 //oop _pending_exception; // pending exception for current thread
168 // const char* _exception_file; // file information for exception (debugging only)
169 // int _exception_line; // line information for exception (debugging only)
170 protected:
171
172 DEBUG_ONLY(static Thread* _starting_thread;)
173
174 // Support for forcing alignment of thread objects for biased locking
175 void* _real_malloc_address;
176
177 // JavaThread lifecycle support:
178 friend class SafeThreadsListPtr; // for _threads_list_ptr, cmpxchg_threads_hazard_ptr(), {dec_,inc_,}nested_threads_hazard_ptr_cnt(), {g,s}et_threads_hazard_ptr(), inc_nested_handle_cnt(), tag_hazard_ptr() access
179 friend class ScanHazardPtrGatherProtectedThreadsClosure; // for cmpxchg_threads_hazard_ptr(), get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
180 friend class ScanHazardPtrGatherThreadsListClosure; // for get_threads_hazard_ptr(), untag_hazard_ptr() access
181 friend class ScanHazardPtrPrintMatchingThreadsClosure; // for get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
182 friend class ThreadsSMRSupport; // for _nested_threads_hazard_ptr_cnt, _threads_hazard_ptr, _threads_list_ptr access
183
184 ThreadsList* volatile _threads_hazard_ptr;
185 SafeThreadsListPtr* _threads_list_ptr;
186 ThreadsList* cmpxchg_threads_hazard_ptr(ThreadsList* exchange_value, ThreadsList* compare_value);
187 ThreadsList* get_threads_hazard_ptr();
188 void set_threads_hazard_ptr(ThreadsList* new_list);
189 static bool is_hazard_ptr_tagged(ThreadsList* list) {
190 return (intptr_t(list) & intptr_t(1)) == intptr_t(1);
191 }
192 static ThreadsList* tag_hazard_ptr(ThreadsList* list) {
193 return (ThreadsList*)(intptr_t(list) | intptr_t(1));
194 }
195 static ThreadsList* untag_hazard_ptr(ThreadsList* list) {
196 return (ThreadsList*)(intptr_t(list) & ~intptr_t(1));
197 }
198 // This field is enabled via -XX:+EnableThreadSMRStatistics:
199 uint _nested_threads_hazard_ptr_cnt;
200 void dec_nested_threads_hazard_ptr_cnt() {
201 assert(_nested_threads_hazard_ptr_cnt != 0, "mismatched {dec,inc}_nested_threads_hazard_ptr_cnt()");
202 _nested_threads_hazard_ptr_cnt--;
203 }
204 void inc_nested_threads_hazard_ptr_cnt() {
205 _nested_threads_hazard_ptr_cnt++;
206 }
207 uint nested_threads_hazard_ptr_cnt() {
208 return _nested_threads_hazard_ptr_cnt;
209 }
210
211 public:
212 void* operator new(size_t size) throw() { return allocate(size, true); }
213 void* operator new(size_t size, const std::nothrow_t& nothrow_constant) throw() {
214 return allocate(size, false); }
215 void operator delete(void* p);
216
217 protected:
218 static void* allocate(size_t size, bool throw_excpt, MEMFLAGS flags = mtThread);
219 private:
220
221 // ***************************************************************
222 // Suspend and resume support
223 // ***************************************************************
224 //
225 // VM suspend/resume no longer exists - it was once used for various
226 // things including safepoints but was deprecated and finally removed
227 // in Java 7. Because VM suspension was considered "internal" Java-level
228 // suspension was considered "external", and this legacy naming scheme
229 // remains.
230 //
231 // External suspend/resume requests come from JVM_SuspendThread,
232 // JVM_ResumeThread, JVMTI SuspendThread, and finally JVMTI
233 // ResumeThread. External
234 // suspend requests cause _external_suspend to be set and external
235 // resume requests cause _external_suspend to be cleared.
236 // External suspend requests do not nest on top of other external
237 // suspend requests. The higher level APIs reject suspend requests
238 // for already suspended threads.
239 //
240 // The external_suspend
241 // flag is checked by has_special_runtime_exit_condition() and java thread
242 // will self-suspend when handle_special_runtime_exit_condition() is
243 // called. Most uses of the _thread_blocked state in JavaThreads are
244 // considered the same as being externally suspended; if the blocking
245 // condition lifts, the JavaThread will self-suspend. Other places
246 // where VM checks for external_suspend include:
247 // + mutex granting (do not enter monitors when thread is suspended)
248 // + state transitions from _thread_in_native
249 //
250 // In general, java_suspend() does not wait for an external suspend
251 // request to complete. When it returns, the only guarantee is that
252 // the _external_suspend field is true.
253 //
254 // wait_for_ext_suspend_completion() is used to wait for an external
255 // suspend request to complete. External suspend requests are usually
256 // followed by some other interface call that requires the thread to
257 // be quiescent, e.g., GetCallTrace(). By moving the "wait time" into
258 // the interface that requires quiescence, we give the JavaThread a
259 // chance to self-suspend before we need it to be quiescent. This
260 // improves overall suspend/query performance.
261 //
262 // _suspend_flags controls the behavior of java_ suspend/resume.
263 // It must be set under the protection of SR_lock. Read from the flag is
264 // OK without SR_lock as long as the value is only used as a hint.
265 // (e.g., check _external_suspend first without lock and then recheck
266 // inside SR_lock and finish the suspension)
267 //
268 // _suspend_flags is also overloaded for other "special conditions" so
269 // that a single check indicates whether any special action is needed
270 // eg. for async exceptions.
271 // -------------------------------------------------------------------
272 // Notes:
273 // 1. The suspend/resume logic no longer uses ThreadState in OSThread
274 // but we still update its value to keep other part of the system (mainly
275 // JVMTI) happy. ThreadState is legacy code (see notes in
276 // osThread.hpp).
277 //
278 // 2. It would be more natural if set_external_suspend() is private and
279 // part of java_suspend(), but that probably would affect the suspend/query
280 // performance. Need more investigation on this.
281
282 // suspend/resume lock: used for self-suspend
283 Monitor* _SR_lock;
284
285 protected:
286 enum SuspendFlags {
287 // NOTE: avoid using the sign-bit as cc generates different test code
288 // when the sign-bit is used, and sometimes incorrectly - see CR 6398077
289
290 _external_suspend = 0x20000000U, // thread is asked to self suspend
291 _ext_suspended = 0x40000000U, // thread has self-suspended
292
293 _has_async_exception = 0x00000001U, // there is a pending async exception
294 _critical_native_unlock = 0x00000002U, // Must call back to unlock JNI critical lock
295
296 _trace_flag = 0x00000004U // call tracing backend
297 };
298
299 // various suspension related flags - atomically updated
300 // overloaded for async exception checking in check_special_condition_for_native_trans.
301 volatile uint32_t _suspend_flags;
302
303 private:
304 int _num_nested_signal;
305
306 DEBUG_ONLY(bool _suspendible_thread;)
307
308 public:
309 void enter_signal_handler() { _num_nested_signal++; }
310 void leave_signal_handler() { _num_nested_signal--; }
311 bool is_inside_signal_handler() const { return _num_nested_signal > 0; }
312
313 // Determines if a heap allocation failure will be retried
314 // (e.g., by deoptimizing and re-executing in the interpreter).
315 // In this case, the failed allocation must raise
316 // Universe::out_of_memory_error_retry() and omit side effects
317 // such as JVMTI events and handling -XX:+HeapDumpOnOutOfMemoryError
318 // and -XX:OnOutOfMemoryError.
319 virtual bool in_retryable_allocation() const { return false; }
320
321 #ifdef ASSERT
322 void set_suspendible_thread() {
323 _suspendible_thread = true;
324 }
325
326 void clear_suspendible_thread() {
327 _suspendible_thread = false;
328 }
329
330 bool is_suspendible_thread() { return _suspendible_thread; }
331 #endif
332
333 private:
334 // Active_handles points to a block of handles
335 JNIHandleBlock* _active_handles;
336
337 // One-element thread local free list
338 JNIHandleBlock* _free_handle_block;
339
340 // Point to the last handle mark
341 HandleMark* _last_handle_mark;
342
343 // Claim value for parallel iteration over threads.
344 uintx _threads_do_token;
345
346 // Support for GlobalCounter
347 private:
348 volatile uintx _rcu_counter;
349 public:
350 volatile uintx* get_rcu_counter() {
351 return &_rcu_counter;
352 }
353
354 public:
355 void set_last_handle_mark(HandleMark* mark) { _last_handle_mark = mark; }
356 HandleMark* last_handle_mark() const { return _last_handle_mark; }
357 private:
358
359 #ifdef ASSERT
360 ICRefillVerifier* _missed_ic_stub_refill_verifier;
361
362 public:
363 ICRefillVerifier* missed_ic_stub_refill_verifier() {
364 return _missed_ic_stub_refill_verifier;
365 }
366
367 void set_missed_ic_stub_refill_verifier(ICRefillVerifier* verifier) {
368 _missed_ic_stub_refill_verifier = verifier;
369 }
370 #endif // ASSERT
371
372 private:
373
374 // Debug support for checking if code allows safepoints or not.
375 // Safepoints in the VM can happen because of allocation, invoking a VM operation, or blocking on
376 // mutex, or blocking on an object synchronizer (Java locking).
377 // If _no_safepoint_count is non-zero, then an assertion failure will happen in any of
378 // the above cases.
379 //
380 // The class NoSafepointVerifier is used to set this counter.
381 //
382 NOT_PRODUCT(int _no_safepoint_count;) // If 0, thread allow a safepoint to happen
383
384 private:
385 // Used by SkipGCALot class.
386 NOT_PRODUCT(bool _skip_gcalot;) // Should we elide gc-a-lot?
387
388 friend class GCLocker;
389 friend class NoSafepointVerifier;
390 friend class PauseNoSafepointVerifier;
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 JvmtiRawMonitor* _current_pending_raw_monitor; // JvmtiRawMonitor this thread
410 // is waiting to lock
411
412
413 // ObjectMonitor on which this thread called Object.wait()
414 ObjectMonitor* _current_waiting_monitor;
415
416 // Per-thread ObjectMonitor lists:
417 public:
418 ObjectMonitor* om_free_list; // SLL of free ObjectMonitors
419 int om_free_count; // # on om_free_list
420 int om_free_provision; // # to try to allocate next
421 ObjectMonitor* om_in_use_list; // SLL of in-use ObjectMonitors
422 int om_in_use_count; // # on om_in_use_list
423
424 #ifdef ASSERT
425 private:
426 volatile uint64_t _visited_for_critical_count;
427
428 public:
429 void set_visited_for_critical_count(uint64_t safepoint_id) {
430 assert(_visited_for_critical_count == 0, "Must be reset before set");
431 assert((safepoint_id & 0x1) == 1, "Must be odd");
432 _visited_for_critical_count = safepoint_id;
433 }
434 void reset_visited_for_critical_count(uint64_t safepoint_id) {
435 assert(_visited_for_critical_count == safepoint_id, "Was not visited");
436 _visited_for_critical_count = 0;
437 }
438 bool was_visited_for_critical_count(uint64_t safepoint_id) const {
439 return _visited_for_critical_count == safepoint_id;
440 }
441 #endif
442
443 public:
444 enum {
445 is_definitely_current_thread = true
446 };
447
448 // Constructor
449 Thread();
450 virtual ~Thread() = 0; // Thread is abstract.
451
452 // Manage Thread::current()
453 void initialize_thread_current();
454 static void clear_thread_current(); // TLS cleanup needed before threads terminate
455
456 protected:
457 // To be implemented by children.
458 virtual void run() = 0;
459 virtual void pre_run() = 0;
460 virtual void post_run() = 0; // Note: Thread must not be deleted prior to calling this!
461
462 #ifdef ASSERT
463 enum RunState {
464 PRE_CALL_RUN,
465 CALL_RUN,
466 PRE_RUN,
467 RUN,
468 POST_RUN
469 // POST_CALL_RUN - can't define this one as 'this' may be deleted when we want to set it
470 };
471 RunState _run_state; // for lifecycle checks
472 #endif
473
474
475 public:
476 // invokes <ChildThreadClass>::run(), with common preparations and cleanups.
477 void call_run();
478
479 // Testers
480 virtual bool is_VM_thread() const { return false; }
481 virtual bool is_Java_thread() const { return false; }
482 virtual bool is_Compiler_thread() const { return false; }
483 virtual bool is_Code_cache_sweeper_thread() const { return false; }
484 virtual bool is_service_thread() const { return false; }
485 virtual bool is_hidden_from_external_view() const { return false; }
486 virtual bool is_jvmti_agent_thread() const { return false; }
487 // True iff the thread can perform GC operations at a safepoint.
488 // Generally will be true only of VM thread and parallel GC WorkGang
489 // threads.
490 virtual bool is_GC_task_thread() const { return false; }
491 virtual bool is_Watcher_thread() const { return false; }
492 virtual bool is_ConcurrentGC_thread() const { return false; }
493 virtual bool is_Named_thread() const { return false; }
494 virtual bool is_Worker_thread() const { return false; }
495
496 // Can this thread make Java upcalls
497 virtual bool can_call_java() const { return false; }
498
499 // Is this a JavaThread that is on the VM's current ThreadsList?
500 // If so it must participate in the safepoint protocol.
501 virtual bool is_active_Java_thread() const { return false; }
502
503 // Casts
504 virtual WorkerThread* as_Worker_thread() const { return NULL; }
505
506 virtual char* name() const { return (char*)"Unknown thread"; }
507
508 // Returns the current thread (ASSERTS if NULL)
509 static inline Thread* current();
510 // Returns the current thread, or NULL if not attached
511 static inline Thread* current_or_null();
512 // Returns the current thread, or NULL if not attached, and is
513 // safe for use from signal-handlers
514 static inline Thread* current_or_null_safe();
515
516 // Common thread operations
517 #ifdef ASSERT
518 static void check_for_dangling_thread_pointer(Thread *thread);
519 #endif
520 static void set_priority(Thread* thread, ThreadPriority priority);
521 static ThreadPriority get_priority(const Thread* const thread);
522 static void start(Thread* thread);
523
524 void set_native_thread_name(const char *name) {
525 assert(Thread::current() == this, "set_native_thread_name can only be called on the current thread");
526 os::set_native_thread_name(name);
527 }
528
529 Monitor* SR_lock() const { return _SR_lock; }
530
531 bool has_async_exception() const { return (_suspend_flags & _has_async_exception) != 0; }
532
533 inline void set_suspend_flag(SuspendFlags f);
534 inline void clear_suspend_flag(SuspendFlags f);
535
536 inline void set_has_async_exception();
537 inline void clear_has_async_exception();
538
539 bool do_critical_native_unlock() const { return (_suspend_flags & _critical_native_unlock) != 0; }
540
541 inline void set_critical_native_unlock();
542 inline void clear_critical_native_unlock();
543
544 inline void set_trace_flag();
545 inline void clear_trace_flag();
546
547 // Support for Unhandled Oop detection
548 // Add the field for both, fastdebug and debug, builds to keep
549 // Thread's fields layout the same.
550 // Note: CHECK_UNHANDLED_OOPS is defined only for fastdebug build.
551 #ifdef CHECK_UNHANDLED_OOPS
552 private:
553 UnhandledOops* _unhandled_oops;
554 #elif defined(ASSERT)
555 private:
556 void* _unhandled_oops;
557 #endif
558 #ifdef CHECK_UNHANDLED_OOPS
559 public:
560 UnhandledOops* unhandled_oops() { return _unhandled_oops; }
561 // Mark oop safe for gc. It may be stack allocated but won't move.
562 void allow_unhandled_oop(oop *op) {
563 if (CheckUnhandledOops) unhandled_oops()->allow_unhandled_oop(op);
564 }
565 // Clear oops at safepoint so crashes point to unhandled oop violator
566 void clear_unhandled_oops() {
567 if (CheckUnhandledOops) unhandled_oops()->clear_unhandled_oops();
568 }
569 #endif // CHECK_UNHANDLED_OOPS
570
571 public:
572 #ifndef PRODUCT
573 bool skip_gcalot() { return _skip_gcalot; }
574 void set_skip_gcalot(bool v) { _skip_gcalot = v; }
575 #endif
576
577 // Installs a pending exception to be inserted later
578 static void send_async_exception(oop thread_oop, oop java_throwable);
579
580 // Resource area
581 ResourceArea* resource_area() const { return _resource_area; }
582 void set_resource_area(ResourceArea* area) { _resource_area = area; }
583
584 OSThread* osthread() const { return _osthread; }
585 void set_osthread(OSThread* thread) { _osthread = thread; }
586
587 // JNI handle support
588 JNIHandleBlock* active_handles() const { return _active_handles; }
589 void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
590 JNIHandleBlock* free_handle_block() const { return _free_handle_block; }
591 void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
592
593 // Internal handle support
594 HandleArea* handle_area() const { return _handle_area; }
595 void set_handle_area(HandleArea* area) { _handle_area = area; }
596
597 GrowableArray<Metadata*>* metadata_handles() const { return _metadata_handles; }
598 void set_metadata_handles(GrowableArray<Metadata*>* handles){ _metadata_handles = handles; }
599
600 // Thread-Local Allocation Buffer (TLAB) support
601 ThreadLocalAllocBuffer& tlab() { return _tlab; }
602 void initialize_tlab() {
603 if (UseTLAB) {
604 tlab().initialize();
605 }
606 }
607
608 jlong allocated_bytes() { return _allocated_bytes; }
609 void set_allocated_bytes(jlong value) { _allocated_bytes = value; }
610 void incr_allocated_bytes(jlong size) { _allocated_bytes += size; }
611 inline jlong cooked_allocated_bytes();
612
613 ThreadHeapSampler& heap_sampler() { return _heap_sampler; }
614
615 ThreadStatisticalInfo& statistical_info() { return _statistical_info; }
616
617 JFR_ONLY(DEFINE_THREAD_LOCAL_ACCESSOR_JFR;)
618
619 bool is_trace_suspend() { return (_suspend_flags & _trace_flag) != 0; }
620
621 // VM operation support
622 int vm_operation_ticket() { return ++_vm_operation_started_count; }
623 int vm_operation_completed_count() { return _vm_operation_completed_count; }
624 void increment_vm_operation_completed_count() { _vm_operation_completed_count++; }
625
626 // For tracking the heavyweight monitor the thread is pending on.
627 ObjectMonitor* current_pending_monitor() {
628 return _current_pending_monitor;
629 }
630 void set_current_pending_monitor(ObjectMonitor* monitor) {
631 _current_pending_monitor = monitor;
632 }
633 void set_current_pending_monitor_is_from_java(bool from_java) {
634 _current_pending_monitor_is_from_java = from_java;
635 }
636 bool current_pending_monitor_is_from_java() {
637 return _current_pending_monitor_is_from_java;
638 }
639
640 // For tracking the ObjectMonitor on which this thread called Object.wait()
641 ObjectMonitor* current_waiting_monitor() {
642 return _current_waiting_monitor;
643 }
644 void set_current_waiting_monitor(ObjectMonitor* monitor) {
645 _current_waiting_monitor = monitor;
646 }
647
648 // For tracking the Jvmti raw monitor the thread is pending on.
649 JvmtiRawMonitor* current_pending_raw_monitor() {
650 return _current_pending_raw_monitor;
651 }
652 void set_current_pending_raw_monitor(JvmtiRawMonitor* monitor) {
653 _current_pending_raw_monitor = monitor;
654 }
655
656 // GC support
657 // Apply "f->do_oop" to all root oops in "this".
658 // Used by JavaThread::oops_do.
659 // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames
660 virtual void oops_do(OopClosure* f, CodeBlobClosure* cf);
661
662 // Handles the parallel case for claim_threads_do.
663 private:
664 bool claim_par_threads_do(uintx claim_token);
665 public:
666 // Requires that "claim_token" is that of the current iteration.
667 // If "is_par" is false, sets the token of "this" to
668 // "claim_token", and returns "true". If "is_par" is true,
669 // uses an atomic instruction to set the current thread's token to
670 // "claim_token", if it is not already. Returns "true" iff the
671 // calling thread does the update, this indicates that the calling thread
672 // has claimed the thread in the current iteration.
673 bool claim_threads_do(bool is_par, uintx claim_token) {
674 if (!is_par) {
675 _threads_do_token = claim_token;
676 return true;
677 } else {
678 return claim_par_threads_do(claim_token);
679 }
680 }
681
682 uintx threads_do_token() const { return _threads_do_token; }
683
684 // jvmtiRedefineClasses support
685 void metadata_handles_do(void f(Metadata*));
686
687 // Used by fast lock support
688 virtual bool is_lock_owned(address adr) const;
689
690 // Check if address is in the live stack of this thread (not just for locks).
691 // Warning: can only be called by the current thread on itself.
692 bool is_in_stack(address adr) const;
693
694 // Check if address in the stack mapped to this thread. Used mainly in
695 // error reporting (so has to include guard zone) and frame printing.
696 bool on_local_stack(address adr) const {
697 return (_stack_base > adr && adr >= stack_end());
698 }
699
700 // Sets this thread as starting thread. Returns failure if thread
701 // creation fails due to lack of memory, too many threads etc.
702 bool set_as_starting_thread();
703
704 protected:
705 // OS data associated with the thread
706 OSThread* _osthread; // Platform-specific thread information
707
708 // Thread local resource area for temporary allocation within the VM
709 ResourceArea* _resource_area;
710
711 DEBUG_ONLY(ResourceMark* _current_resource_mark;)
712
713 // Thread local handle area for allocation of handles within the VM
714 HandleArea* _handle_area;
715 GrowableArray<Metadata*>* _metadata_handles;
716
717 // Support for stack overflow handling, get_thread, etc.
718 address _stack_base;
719 size_t _stack_size;
720 int _lgrp_id;
721
722 volatile void** polling_page_addr() { return &_polling_page; }
723
724 public:
725 // Stack overflow support
726 address stack_base() const { assert(_stack_base != NULL,"Sanity check"); return _stack_base; }
727 void set_stack_base(address base) { _stack_base = base; }
728 size_t stack_size() const { return _stack_size; }
729 void set_stack_size(size_t size) { _stack_size = size; }
730 address stack_end() const { return stack_base() - stack_size(); }
731 void record_stack_base_and_size();
732 void register_thread_stack_with_NMT() NOT_NMT_RETURN;
733
734 int lgrp_id() const { return _lgrp_id; }
735 void set_lgrp_id(int value) { _lgrp_id = value; }
736
737 // Printing
738 void print_on(outputStream* st, bool print_extended_info) const;
739 virtual void print_on(outputStream* st) const { print_on(st, false); }
740 void print() const;
741 virtual void print_on_error(outputStream* st, char* buf, int buflen) const;
742 void print_value_on(outputStream* st) const;
743
744 // Debug-only code
745 #ifdef ASSERT
746 private:
747 // Deadlock detection support for Mutex locks. List of locks own by thread.
748 Mutex* _owned_locks;
749 // Mutex::set_owner_implementation is the only place where _owned_locks is modified,
750 // thus the friendship
751 friend class Mutex;
752 friend class Monitor;
753
754 public:
755 void print_owned_locks_on(outputStream* st) const;
756 void print_owned_locks() const { print_owned_locks_on(tty); }
757 Mutex* owned_locks() const { return _owned_locks; }
758 bool owns_locks() const { return owned_locks() != NULL; }
759
760 // Deadlock detection
761 ResourceMark* current_resource_mark() { return _current_resource_mark; }
762 void set_current_resource_mark(ResourceMark* rm) { _current_resource_mark = rm; }
763 #endif // ASSERT
764
765 // These functions check conditions on a JavaThread before possibly going to a safepoint,
766 // including NoSafepointVerifier.
767 void check_for_valid_safepoint_state() NOT_DEBUG_RETURN;
768 void check_possible_safepoint() NOT_DEBUG_RETURN;
769
770 private:
771 volatile int _jvmti_env_iteration_count;
772
773 public:
774 void entering_jvmti_env_iteration() { ++_jvmti_env_iteration_count; }
775 void leaving_jvmti_env_iteration() { --_jvmti_env_iteration_count; }
776 bool is_inside_jvmti_env_iteration() { return _jvmti_env_iteration_count > 0; }
777
778 // Code generation
779 static ByteSize exception_file_offset() { return byte_offset_of(Thread, _exception_file); }
780 static ByteSize exception_line_offset() { return byte_offset_of(Thread, _exception_line); }
781 static ByteSize active_handles_offset() { return byte_offset_of(Thread, _active_handles); }
782
783 static ByteSize stack_base_offset() { return byte_offset_of(Thread, _stack_base); }
784 static ByteSize stack_size_offset() { return byte_offset_of(Thread, _stack_size); }
785
786 static ByteSize polling_page_offset() { return byte_offset_of(Thread, _polling_page); }
787
788 static ByteSize tlab_start_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::start_offset(); }
789 static ByteSize tlab_end_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::end_offset(); }
790 static ByteSize tlab_top_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::top_offset(); }
791 static ByteSize tlab_pf_top_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::pf_top_offset(); }
792
793 static ByteSize allocated_bytes_offset() { return byte_offset_of(Thread, _allocated_bytes); }
794
795 JFR_ONLY(DEFINE_THREAD_LOCAL_OFFSET_JFR;)
796
797 public:
798 volatile intptr_t _Stalled;
799 volatile int _TypeTag;
800 ParkEvent * _ParkEvent; // for Object monitors and JVMTI raw monitors
801 ParkEvent * _MuxEvent; // for low-level muxAcquire-muxRelease
802 int NativeSyncRecursion; // diagnostic
803
804 volatile int _OnTrap; // Resume-at IP delta
805 jint _hashStateW; // Marsaglia Shift-XOR thread-local RNG
806 jint _hashStateX; // thread-specific hashCode generator state
807 jint _hashStateY;
808 jint _hashStateZ;
809
810 // Low-level leaf-lock primitives used to implement synchronization
811 // and native monitor-mutex infrastructure.
812 // Not for general synchronization use.
813 static void SpinAcquire(volatile int * Lock, const char * Name);
814 static void SpinRelease(volatile int * Lock);
815 static void muxAcquire(volatile intptr_t * Lock, const char * Name);
816 static void muxRelease(volatile intptr_t * Lock);
817 };
818
819 // Inline implementation of Thread::current()
820 inline Thread* Thread::current() {
821 Thread* current = current_or_null();
822 assert(current != NULL, "Thread::current() called on detached thread");
823 return current;
824 }
825
826 inline Thread* Thread::current_or_null() {
827 #ifndef USE_LIBRARY_BASED_TLS_ONLY
828 return _thr_current;
829 #else
830 if (ThreadLocalStorage::is_initialized()) {
831 return ThreadLocalStorage::thread();
832 }
833 return NULL;
834 #endif
835 }
836
837 inline Thread* Thread::current_or_null_safe() {
838 if (ThreadLocalStorage::is_initialized()) {
839 return ThreadLocalStorage::thread();
840 }
841 return NULL;
842 }
843
844 class NonJavaThread: public Thread {
845 friend class VMStructs;
846
847 NonJavaThread* volatile _next;
848
849 class List;
850 static List _the_list;
851
852 void add_to_the_list();
853 void remove_from_the_list();
854
855 protected:
856 virtual void pre_run();
857 virtual void post_run();
858
859 public:
860 NonJavaThread();
861 ~NonJavaThread();
862
863 class Iterator;
864 };
865
866 // Provides iteration over the list of NonJavaThreads.
867 // List addition occurs in pre_run(), and removal occurs in post_run(),
868 // so that only live fully-initialized threads can be found in the list.
869 // Threads created after an iterator is constructed will not be visited
870 // by the iterator. The scope of an iterator is a critical section; there
871 // must be no safepoint checks in that scope.
872 class NonJavaThread::Iterator : public StackObj {
873 uint _protect_enter;
874 NonJavaThread* _current;
875
876 NONCOPYABLE(Iterator);
877
878 public:
879 Iterator();
880 ~Iterator();
881
882 bool end() const { return _current == NULL; }
883 NonJavaThread* current() const { return _current; }
884 void step();
885 };
886
887 // Name support for threads. non-JavaThread subclasses with multiple
888 // uniquely named instances should derive from this.
889 class NamedThread: public NonJavaThread {
890 friend class VMStructs;
891 enum {
892 max_name_len = 64
893 };
894 private:
895 char* _name;
896 // log JavaThread being processed by oops_do
897 JavaThread* _processed_thread;
898 uint _gc_id; // The current GC id when a thread takes part in GC
899
900 public:
901 NamedThread();
902 ~NamedThread();
903 // May only be called once per thread.
904 void set_name(const char* format, ...) ATTRIBUTE_PRINTF(2, 3);
905 virtual bool is_Named_thread() const { return true; }
906 virtual char* name() const { return _name == NULL ? (char*)"Unknown Thread" : _name; }
907 JavaThread *processed_thread() { return _processed_thread; }
908 void set_processed_thread(JavaThread *thread) { _processed_thread = thread; }
909 virtual void print_on(outputStream* st) const;
910
911 void set_gc_id(uint gc_id) { _gc_id = gc_id; }
912 uint gc_id() { return _gc_id; }
913 };
914
915 // Worker threads are named and have an id of an assigned work.
916 class WorkerThread: public NamedThread {
917 private:
918 uint _id;
919 public:
920 WorkerThread() : _id(0) { }
921 virtual bool is_Worker_thread() const { return true; }
922
923 virtual WorkerThread* as_Worker_thread() const {
924 assert(is_Worker_thread(), "Dubious cast to WorkerThread*?");
925 return (WorkerThread*) this;
926 }
927
928 void set_id(uint work_id) { _id = work_id; }
929 uint id() const { return _id; }
930 };
931
932 // A single WatcherThread is used for simulating timer interrupts.
933 class WatcherThread: public NonJavaThread {
934 friend class VMStructs;
935 protected:
936 virtual void run();
937
938 private:
939 static WatcherThread* _watcher_thread;
940
941 static bool _startable;
942 // volatile due to at least one lock-free read
943 volatile static bool _should_terminate;
944 public:
945 enum SomeConstants {
946 delay_interval = 10 // interrupt delay in milliseconds
947 };
948
949 // Constructor
950 WatcherThread();
951
952 // No destruction allowed
953 ~WatcherThread() {
954 guarantee(false, "WatcherThread deletion must fix the race with VM termination");
955 }
956
957 // Tester
958 bool is_Watcher_thread() const { return true; }
959
960 // Printing
961 char* name() const { return (char*)"VM Periodic Task Thread"; }
962 void print_on(outputStream* st) const;
963 void unpark();
964
965 // Returns the single instance of WatcherThread
966 static WatcherThread* watcher_thread() { return _watcher_thread; }
967
968 // Create and start the single instance of WatcherThread, or stop it on shutdown
969 static void start();
970 static void stop();
971 // Only allow start once the VM is sufficiently initialized
972 // Otherwise the first task to enroll will trigger the start
973 static void make_startable();
974 private:
975 int sleep() const;
976 };
977
978
979 class CompilerThread;
980
981 typedef void (*ThreadFunction)(JavaThread*, TRAPS);
982
983 class JavaThread: public Thread {
984 friend class VMStructs;
985 friend class JVMCIVMStructs;
986 friend class WhiteBox;
987 private:
988 bool _on_thread_list; // Is set when this JavaThread is added to the Threads list
989 oop _threadObj; // The Java level thread object
990
991 #ifdef ASSERT
992 private:
993 int _java_call_counter;
994
995 public:
996 int java_call_counter() { return _java_call_counter; }
997 void inc_java_call_counter() { _java_call_counter++; }
998 void dec_java_call_counter() {
999 assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
1000 _java_call_counter--;
1001 }
1002 private: // restore original namespace restriction
1003 #endif // ifdef ASSERT
1004
1005 #ifndef PRODUCT
1006 public:
1007 enum {
1008 jump_ring_buffer_size = 16
1009 };
1010 private: // restore original namespace restriction
1011 #endif
1012
1013 JavaFrameAnchor _anchor; // Encapsulation of current java frame and it state
1014
1015 ThreadFunction _entry_point;
1016
1017 JNIEnv _jni_environment;
1018
1019 // Deopt support
1020 DeoptResourceMark* _deopt_mark; // Holds special ResourceMark for deoptimization
1021
1022 CompiledMethod* _deopt_nmethod; // CompiledMethod that is currently being deoptimized
1023 vframeArray* _vframe_array_head; // Holds the heap of the active vframeArrays
1024 vframeArray* _vframe_array_last; // Holds last vFrameArray we popped
1025 // Because deoptimization is lazy we must save jvmti requests to set locals
1026 // in compiled frames until we deoptimize and we have an interpreter frame.
1027 // This holds the pointer to array (yeah like there might be more than one) of
1028 // description of compiled vframes that have locals that need to be updated.
1029 GrowableArray<jvmtiDeferredLocalVariableSet*>* _deferred_locals_updates;
1030
1031 // Handshake value for fixing 6243940. We need a place for the i2c
1032 // adapter to store the callee Method*. This value is NEVER live
1033 // across a gc point so it does NOT have to be gc'd
1034 // The handshake is open ended since we can't be certain that it will
1035 // be NULLed. This is because we rarely ever see the race and end up
1036 // in handle_wrong_method which is the backend of the handshake. See
1037 // code in i2c adapters and handle_wrong_method.
1038
1039 Method* _callee_target;
1040
1041 // Used to pass back results to the interpreter or generated code running Java code.
1042 oop _vm_result; // oop result is GC-preserved
1043 Metadata* _vm_result_2; // non-oop result
1044
1045 // See ReduceInitialCardMarks: this holds the precise space interval of
1046 // the most recent slow path allocation for which compiled code has
1047 // elided card-marks for performance along the fast-path.
1048 MemRegion _deferred_card_mark;
1049
1050 MonitorChunk* _monitor_chunks; // Contains the off stack monitors
1051 // allocated during deoptimization
1052 // and by JNI_MonitorEnter/Exit
1053
1054 // Async. requests support
1055 enum AsyncRequests {
1056 _no_async_condition = 0,
1057 _async_exception,
1058 _async_unsafe_access_error
1059 };
1060 AsyncRequests _special_runtime_exit_condition; // Enum indicating pending async. request
1061 oop _pending_async_exception;
1062
1063 // Safepoint support
1064 public: // Expose _thread_state for SafeFetchInt()
1065 volatile JavaThreadState _thread_state;
1066 private:
1067 ThreadSafepointState* _safepoint_state; // Holds information about a thread during a safepoint
1068 address _saved_exception_pc; // Saved pc of instruction where last implicit exception happened
1069
1070 // JavaThread termination support
1071 enum TerminatedTypes {
1072 _not_terminated = 0xDEAD - 2,
1073 _thread_exiting, // JavaThread::exit() has been called for this thread
1074 _thread_terminated, // JavaThread is removed from thread list
1075 _vm_exited // JavaThread is still executing native code, but VM is terminated
1076 // only VM_Exit can set _vm_exited
1077 };
1078
1079 // In general a JavaThread's _terminated field transitions as follows:
1080 //
1081 // _not_terminated => _thread_exiting => _thread_terminated
1082 //
1083 // _vm_exited is a special value to cover the case of a JavaThread
1084 // executing native code after the VM itself is terminated.
1085 volatile TerminatedTypes _terminated;
1086 // suspend/resume support
1087 volatile bool _suspend_equivalent; // Suspend equivalent condition
1088 jint _in_deopt_handler; // count of deoptimization
1089 // handlers thread is in
1090 volatile bool _doing_unsafe_access; // Thread may fault due to unsafe access
1091 bool _do_not_unlock_if_synchronized; // Do not unlock the receiver of a synchronized method (since it was
1092 // never locked) when throwing an exception. Used by interpreter only.
1093
1094 // JNI attach states:
1095 enum JNIAttachStates {
1096 _not_attaching_via_jni = 1, // thread is not attaching via JNI
1097 _attaching_via_jni, // thread is attaching via JNI
1098 _attached_via_jni // thread has attached via JNI
1099 };
1100
1101 // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
1102 // A native thread that is attaching via JNI starts with a value
1103 // of _attaching_via_jni and transitions to _attached_via_jni.
1104 volatile JNIAttachStates _jni_attach_state;
1105
1106 public:
1107 // State of the stack guard pages for this thread.
1108 enum StackGuardState {
1109 stack_guard_unused, // not needed
1110 stack_guard_reserved_disabled,
1111 stack_guard_yellow_reserved_disabled,// disabled (temporarily) after stack overflow
1112 stack_guard_enabled // enabled
1113 };
1114
1115 private:
1116
1117 #if INCLUDE_JVMCI
1118 // The _pending_* fields below are used to communicate extra information
1119 // from an uncommon trap in JVMCI compiled code to the uncommon trap handler.
1120
1121 // Communicates the DeoptReason and DeoptAction of the uncommon trap
1122 int _pending_deoptimization;
1123
1124 // Specifies whether the uncommon trap is to bci 0 of a synchronized method
1125 // before the monitor has been acquired.
1126 bool _pending_monitorenter;
1127
1128 // Specifies if the DeoptReason for the last uncommon trap was Reason_transfer_to_interpreter
1129 bool _pending_transfer_to_interpreter;
1130
1131 // True if in a runtime call from compiled code that will deoptimize
1132 // and re-execute a failed heap allocation in the interpreter.
1133 bool _in_retryable_allocation;
1134
1135 // An id of a speculation that JVMCI compiled code can use to further describe and
1136 // uniquely identify the speculative optimization guarded by the uncommon trap
1137 jlong _pending_failed_speculation;
1138
1139 // These fields are mutually exclusive in terms of live ranges.
1140 union {
1141 // Communicates the pc at which the most recent implicit exception occurred
1142 // from the signal handler to a deoptimization stub.
1143 address _implicit_exception_pc;
1144
1145 // Communicates an alternative call target to an i2c stub from a JavaCall .
1146 address _alternate_call_target;
1147 } _jvmci;
1148
1149 // Support for high precision, thread sensitive counters in JVMCI compiled code.
1150 jlong* _jvmci_counters;
1151
1152 public:
1153 static jlong* _jvmci_old_thread_counters;
1154 static void collect_counters(jlong* array, int length);
1155 void resize_counters(int current_size, int new_size);
1156 static void resize_all_jvmci_counters(int new_size);
1157
1158 private:
1159 #endif // INCLUDE_JVMCI
1160
1161 StackGuardState _stack_guard_state;
1162
1163 // Precompute the limit of the stack as used in stack overflow checks.
1164 // We load it from here to simplify the stack overflow check in assembly.
1165 address _stack_overflow_limit;
1166 address _reserved_stack_activation;
1167
1168 // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
1169 // used to temp. parsing values into and out of the runtime system during exception handling for compiled
1170 // code)
1171 volatile oop _exception_oop; // Exception thrown in compiled code
1172 volatile address _exception_pc; // PC where exception happened
1173 volatile address _exception_handler_pc; // PC for handler of exception
1174 volatile int _is_method_handle_return; // true (== 1) if the current exception PC is a MethodHandle call site.
1175
1176 private:
1177 // support for JNI critical regions
1178 jint _jni_active_critical; // count of entries into JNI critical region
1179
1180 // Checked JNI: function name requires exception check
1181 char* _pending_jni_exception_check_fn;
1182
1183 // For deadlock detection.
1184 int _depth_first_number;
1185
1186 // JVMTI PopFrame support
1187 // This is set to popframe_pending to signal that top Java frame should be popped immediately
1188 int _popframe_condition;
1189
1190 // If reallocation of scalar replaced objects fails, we throw OOM
1191 // and during exception propagation, pop the top
1192 // _frames_to_pop_failed_realloc frames, the ones that reference
1193 // failed reallocations.
1194 int _frames_to_pop_failed_realloc;
1195
1196 friend class VMThread;
1197 friend class ThreadWaitTransition;
1198 friend class VM_Exit;
1199
1200 void initialize(); // Initialized the instance variables
1201
1202 public:
1203 // Constructor
1204 JavaThread(bool is_attaching_via_jni = false); // for main thread and JNI attached threads
1205 JavaThread(ThreadFunction entry_point, size_t stack_size = 0);
1206 ~JavaThread();
1207
1208 #ifdef ASSERT
1209 // verify this JavaThread hasn't be published in the Threads::list yet
1210 void verify_not_published();
1211 #endif // ASSERT
1212
1213 //JNI functiontable getter/setter for JVMTI jni function table interception API.
1214 void set_jni_functions(struct JNINativeInterface_* functionTable) {
1215 _jni_environment.functions = functionTable;
1216 }
1217 struct JNINativeInterface_* get_jni_functions() {
1218 return (struct JNINativeInterface_ *)_jni_environment.functions;
1219 }
1220
1221 // This function is called at thread creation to allow
1222 // platform specific thread variables to be initialized.
1223 void cache_global_variables();
1224
1225 // Executes Shutdown.shutdown()
1226 void invoke_shutdown_hooks();
1227
1228 // Cleanup on thread exit
1229 enum ExitType {
1230 normal_exit,
1231 jni_detach
1232 };
1233 void exit(bool destroy_vm, ExitType exit_type = normal_exit);
1234
1235 void cleanup_failed_attach_current_thread(bool is_daemon);
1236
1237 // Testers
1238 virtual bool is_Java_thread() const { return true; }
1239 virtual bool can_call_java() const { return true; }
1240
1241 virtual bool is_active_Java_thread() const {
1242 return on_thread_list() && !is_terminated();
1243 }
1244
1245 // Thread oop. threadObj() can be NULL for initial JavaThread
1246 // (or for threads attached via JNI)
1247 oop threadObj() const { return _threadObj; }
1248 void set_threadObj(oop p) { _threadObj = p; }
1249
1250 // Prepare thread and add to priority queue. If a priority is
1251 // not specified, use the priority of the thread object. Threads_lock
1252 // must be held while this function is called.
1253 void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
1254
1255 void set_saved_exception_pc(address pc) { _saved_exception_pc = pc; }
1256 address saved_exception_pc() { return _saved_exception_pc; }
1257
1258
1259 ThreadFunction entry_point() const { return _entry_point; }
1260
1261 // Allocates a new Java level thread object for this thread. thread_name may be NULL.
1262 void allocate_threadObj(Handle thread_group, const char* thread_name, bool daemon, TRAPS);
1263
1264 // Last frame anchor routines
1265
1266 JavaFrameAnchor* frame_anchor(void) { return &_anchor; }
1267
1268 // last_Java_sp
1269 bool has_last_Java_frame() const { return _anchor.has_last_Java_frame(); }
1270 intptr_t* last_Java_sp() const { return _anchor.last_Java_sp(); }
1271
1272 // last_Java_pc
1273
1274 address last_Java_pc(void) { return _anchor.last_Java_pc(); }
1275
1276 // Safepoint support
1277 inline JavaThreadState thread_state() const;
1278 inline void set_thread_state(JavaThreadState s);
1279 inline void set_thread_state_fence(JavaThreadState s); // fence after setting thread state
1280 inline ThreadSafepointState* safepoint_state() const;
1281 inline void set_safepoint_state(ThreadSafepointState* state);
1282 inline bool is_at_poll_safepoint();
1283
1284 // JavaThread termination and lifecycle support:
1285 void smr_delete();
1286 bool on_thread_list() const { return _on_thread_list; }
1287 void set_on_thread_list() { _on_thread_list = true; }
1288
1289 // thread has called JavaThread::exit() or is terminated
1290 bool is_exiting() const;
1291 // thread is terminated (no longer on the threads list); we compare
1292 // against the two non-terminated values so that a freed JavaThread
1293 // will also be considered terminated.
1294 bool check_is_terminated(TerminatedTypes l_terminated) const {
1295 return l_terminated != _not_terminated && l_terminated != _thread_exiting;
1296 }
1297 bool is_terminated() const;
1298 void set_terminated(TerminatedTypes t);
1299 // special for Threads::remove() which is static:
1300 void set_terminated_value();
1301 void block_if_vm_exited();
1302
1303 bool doing_unsafe_access() { return _doing_unsafe_access; }
1304 void set_doing_unsafe_access(bool val) { _doing_unsafe_access = val; }
1305
1306 bool do_not_unlock_if_synchronized() { return _do_not_unlock_if_synchronized; }
1307 void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
1308
1309 inline void set_polling_page_release(void* poll_value);
1310 inline void set_polling_page(void* poll_value);
1311 inline volatile void* get_polling_page();
1312
1313 private:
1314 // Support for thread handshake operations
1315 HandshakeState _handshake;
1316 public:
1317 void set_handshake_operation(HandshakeOperation* op) {
1318 _handshake.set_operation(this, op);
1319 }
1320
1321 bool has_handshake() const {
1322 return _handshake.has_operation();
1323 }
1324
1325 void handshake_process_by_self() {
1326 _handshake.process_by_self(this);
1327 }
1328
1329 bool handshake_try_process_by_vmThread() {
1330 return _handshake.try_process_by_vmThread(this);
1331 }
1332
1333 #ifdef ASSERT
1334 bool is_vmthread_processing_handshake() const {
1335 return _handshake.is_vmthread_processing_handshake();
1336 }
1337 #endif
1338
1339 // Suspend/resume support for JavaThread
1340 private:
1341 inline void set_ext_suspended();
1342 inline void clear_ext_suspended();
1343
1344 public:
1345 void java_suspend(); // higher-level suspension logic called by the public APIs
1346 void java_resume(); // higher-level resume logic called by the public APIs
1347 int java_suspend_self(); // low-level self-suspension mechanics
1348
1349 private:
1350 // mid-level wrapper around java_suspend_self to set up correct state and
1351 // check for a pending safepoint at the end
1352 void java_suspend_self_with_safepoint_check();
1353
1354 public:
1355 void check_and_wait_while_suspended() {
1356 assert(JavaThread::current() == this, "sanity check");
1357
1358 bool do_self_suspend;
1359 do {
1360 // were we externally suspended while we were waiting?
1361 do_self_suspend = handle_special_suspend_equivalent_condition();
1362 if (do_self_suspend) {
1363 // don't surprise the thread that suspended us by returning
1364 java_suspend_self();
1365 set_suspend_equivalent();
1366 }
1367 } while (do_self_suspend);
1368 }
1369 static void check_safepoint_and_suspend_for_native_trans(JavaThread *thread);
1370 // Check for async exception in addition to safepoint and suspend request.
1371 static void check_special_condition_for_native_trans(JavaThread *thread);
1372
1373 // Same as check_special_condition_for_native_trans but finishes the
1374 // transition into thread_in_Java mode so that it can potentially
1375 // block.
1376 static void check_special_condition_for_native_trans_and_transition(JavaThread *thread);
1377
1378 bool is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits);
1379 bool is_ext_suspend_completed_with_lock(uint32_t *bits) {
1380 MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1381 // Warning: is_ext_suspend_completed() may temporarily drop the
1382 // SR_lock to allow the thread to reach a stable thread state if
1383 // it is currently in a transient thread state.
1384 return is_ext_suspend_completed(false /* !called_by_wait */,
1385 SuspendRetryDelay, bits);
1386 }
1387
1388 // We cannot allow wait_for_ext_suspend_completion() to run forever or
1389 // we could hang. SuspendRetryCount and SuspendRetryDelay are normally
1390 // passed as the count and delay parameters. Experiments with specific
1391 // calls to wait_for_ext_suspend_completion() can be done by passing
1392 // other values in the code. Experiments with all calls can be done
1393 // via the appropriate -XX options.
1394 bool wait_for_ext_suspend_completion(int count, int delay, uint32_t *bits);
1395
1396 // test for suspend - most (all?) of these should go away
1397 bool is_thread_fully_suspended(bool wait_for_suspend, uint32_t *bits);
1398
1399 inline void set_external_suspend();
1400 inline void clear_external_suspend();
1401
1402 bool is_external_suspend() const {
1403 return (_suspend_flags & _external_suspend) != 0;
1404 }
1405 // Whenever a thread transitions from native to vm/java it must suspend
1406 // if external|deopt suspend is present.
1407 bool is_suspend_after_native() const {
1408 return (_suspend_flags & (_external_suspend JFR_ONLY(| _trace_flag))) != 0;
1409 }
1410
1411 // external suspend request is completed
1412 bool is_ext_suspended() const {
1413 return (_suspend_flags & _ext_suspended) != 0;
1414 }
1415
1416 bool is_external_suspend_with_lock() const {
1417 MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1418 return is_external_suspend();
1419 }
1420
1421 // Special method to handle a pending external suspend request
1422 // when a suspend equivalent condition lifts.
1423 bool handle_special_suspend_equivalent_condition() {
1424 assert(is_suspend_equivalent(),
1425 "should only be called in a suspend equivalence condition");
1426 MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1427 bool ret = is_external_suspend();
1428 if (!ret) {
1429 // not about to self-suspend so clear suspend equivalence
1430 clear_suspend_equivalent();
1431 }
1432 // implied else:
1433 // We have a pending external suspend request so we leave the
1434 // suspend_equivalent flag set until java_suspend_self() sets
1435 // the ext_suspended flag and clears the suspend_equivalent
1436 // flag. This insures that wait_for_ext_suspend_completion()
1437 // will return consistent values.
1438 return ret;
1439 }
1440
1441 // utility methods to see if we are doing some kind of suspension
1442 bool is_being_ext_suspended() const {
1443 MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1444 return is_ext_suspended() || is_external_suspend();
1445 }
1446
1447 bool is_suspend_equivalent() const { return _suspend_equivalent; }
1448
1449 void set_suspend_equivalent() { _suspend_equivalent = true; }
1450 void clear_suspend_equivalent() { _suspend_equivalent = false; }
1451
1452 // Thread.stop support
1453 void send_thread_stop(oop throwable);
1454 AsyncRequests clear_special_runtime_exit_condition() {
1455 AsyncRequests x = _special_runtime_exit_condition;
1456 _special_runtime_exit_condition = _no_async_condition;
1457 return x;
1458 }
1459
1460 // Are any async conditions present?
1461 bool has_async_condition() { return (_special_runtime_exit_condition != _no_async_condition); }
1462
1463 void check_and_handle_async_exceptions(bool check_unsafe_error = true);
1464
1465 // these next two are also used for self-suspension and async exception support
1466 void handle_special_runtime_exit_condition(bool check_asyncs = true);
1467
1468 // Return true if JavaThread has an asynchronous condition or
1469 // if external suspension is requested.
1470 bool has_special_runtime_exit_condition() {
1471 // Because we don't use is_external_suspend_with_lock
1472 // it is possible that we won't see an asynchronous external suspend
1473 // request that has just gotten started, i.e., SR_lock grabbed but
1474 // _external_suspend field change either not made yet or not visible
1475 // yet. However, this is okay because the request is asynchronous and
1476 // we will see the new flag value the next time through. It's also
1477 // possible that the external suspend request is dropped after
1478 // we have checked is_external_suspend(), we will recheck its value
1479 // under SR_lock in java_suspend_self().
1480 return (_special_runtime_exit_condition != _no_async_condition) ||
1481 is_external_suspend() || is_trace_suspend();
1482 }
1483
1484 void set_pending_unsafe_access_error() { _special_runtime_exit_condition = _async_unsafe_access_error; }
1485
1486 inline void set_pending_async_exception(oop e);
1487
1488 // Fast-locking support
1489 bool is_lock_owned(address adr) const;
1490
1491 // Accessors for vframe array top
1492 // The linked list of vframe arrays are sorted on sp. This means when we
1493 // unpack the head must contain the vframe array to unpack.
1494 void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
1495 vframeArray* vframe_array_head() const { return _vframe_array_head; }
1496
1497 // Side structure for deferring update of java frame locals until deopt occurs
1498 GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred_locals() const { return _deferred_locals_updates; }
1499 void set_deferred_locals(GrowableArray<jvmtiDeferredLocalVariableSet *>* vf) { _deferred_locals_updates = vf; }
1500
1501 // These only really exist to make debugging deopt problems simpler
1502
1503 void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
1504 vframeArray* vframe_array_last() const { return _vframe_array_last; }
1505
1506 // The special resourceMark used during deoptimization
1507
1508 void set_deopt_mark(DeoptResourceMark* value) { _deopt_mark = value; }
1509 DeoptResourceMark* deopt_mark(void) { return _deopt_mark; }
1510
1511 void set_deopt_compiled_method(CompiledMethod* nm) { _deopt_nmethod = nm; }
1512 CompiledMethod* deopt_compiled_method() { return _deopt_nmethod; }
1513
1514 Method* callee_target() const { return _callee_target; }
1515 void set_callee_target (Method* x) { _callee_target = x; }
1516
1517 // Oop results of vm runtime calls
1518 oop vm_result() const { return _vm_result; }
1519 void set_vm_result (oop x) { _vm_result = x; }
1520
1521 Metadata* vm_result_2() const { return _vm_result_2; }
1522 void set_vm_result_2 (Metadata* x) { _vm_result_2 = x; }
1523
1524 MemRegion deferred_card_mark() const { return _deferred_card_mark; }
1525 void set_deferred_card_mark(MemRegion mr) { _deferred_card_mark = mr; }
1526
1527 #if INCLUDE_JVMCI
1528 int pending_deoptimization() const { return _pending_deoptimization; }
1529 jlong pending_failed_speculation() const { return _pending_failed_speculation; }
1530 bool has_pending_monitorenter() const { return _pending_monitorenter; }
1531 void set_pending_monitorenter(bool b) { _pending_monitorenter = b; }
1532 void set_pending_deoptimization(int reason) { _pending_deoptimization = reason; }
1533 void set_pending_failed_speculation(jlong failed_speculation) { _pending_failed_speculation = failed_speculation; }
1534 void set_pending_transfer_to_interpreter(bool b) { _pending_transfer_to_interpreter = b; }
1535 void set_jvmci_alternate_call_target(address a) { assert(_jvmci._alternate_call_target == NULL, "must be"); _jvmci._alternate_call_target = a; }
1536 void set_jvmci_implicit_exception_pc(address a) { assert(_jvmci._implicit_exception_pc == NULL, "must be"); _jvmci._implicit_exception_pc = a; }
1537
1538 virtual bool in_retryable_allocation() const { return _in_retryable_allocation; }
1539 void set_in_retryable_allocation(bool b) { _in_retryable_allocation = b; }
1540 #endif // INCLUDE_JVMCI
1541
1542 // Exception handling for compiled methods
1543 oop exception_oop() const { return _exception_oop; }
1544 address exception_pc() const { return _exception_pc; }
1545 address exception_handler_pc() const { return _exception_handler_pc; }
1546 bool is_method_handle_return() const { return _is_method_handle_return == 1; }
1547
1548 void set_exception_oop(oop o) { (void)const_cast<oop&>(_exception_oop = o); }
1549 void set_exception_pc(address a) { _exception_pc = a; }
1550 void set_exception_handler_pc(address a) { _exception_handler_pc = a; }
1551 void set_is_method_handle_return(bool value) { _is_method_handle_return = value ? 1 : 0; }
1552
1553 void clear_exception_oop_and_pc() {
1554 set_exception_oop(NULL);
1555 set_exception_pc(NULL);
1556 }
1557
1558 // Stack overflow support
1559 //
1560 // (small addresses)
1561 //
1562 // -- <-- stack_end() ---
1563 // | |
1564 // | red pages |
1565 // | |
1566 // -- <-- stack_red_zone_base() |
1567 // | |
1568 // | guard
1569 // | yellow pages zone
1570 // | |
1571 // | |
1572 // -- <-- stack_yellow_zone_base() |
1573 // | |
1574 // | |
1575 // | reserved pages |
1576 // | |
1577 // -- <-- stack_reserved_zone_base() --- ---
1578 // /|\ shadow <-- stack_overflow_limit() (somewhere in here)
1579 // | zone
1580 // \|/ size
1581 // some untouched memory ---
1582 //
1583 //
1584 // --
1585 // |
1586 // | shadow zone
1587 // |
1588 // --
1589 // x frame n
1590 // --
1591 // x frame n-1
1592 // x
1593 // --
1594 // ...
1595 //
1596 // --
1597 // x frame 0
1598 // -- <-- stack_base()
1599 //
1600 // (large addresses)
1601 //
1602
1603 private:
1604 // These values are derived from flags StackRedPages, StackYellowPages,
1605 // StackReservedPages and StackShadowPages. The zone size is determined
1606 // ergonomically if page_size > 4K.
1607 static size_t _stack_red_zone_size;
1608 static size_t _stack_yellow_zone_size;
1609 static size_t _stack_reserved_zone_size;
1610 static size_t _stack_shadow_zone_size;
1611 public:
1612 inline size_t stack_available(address cur_sp);
1613
1614 static size_t stack_red_zone_size() {
1615 assert(_stack_red_zone_size > 0, "Don't call this before the field is initialized.");
1616 return _stack_red_zone_size;
1617 }
1618 static void set_stack_red_zone_size(size_t s) {
1619 assert(is_aligned(s, os::vm_page_size()),
1620 "We can not protect if the red zone size is not page aligned.");
1621 assert(_stack_red_zone_size == 0, "This should be called only once.");
1622 _stack_red_zone_size = s;
1623 }
1624 address stack_red_zone_base() {
1625 return (address)(stack_end() + stack_red_zone_size());
1626 }
1627 bool in_stack_red_zone(address a) {
1628 return a <= stack_red_zone_base() && a >= stack_end();
1629 }
1630
1631 static size_t stack_yellow_zone_size() {
1632 assert(_stack_yellow_zone_size > 0, "Don't call this before the field is initialized.");
1633 return _stack_yellow_zone_size;
1634 }
1635 static void set_stack_yellow_zone_size(size_t s) {
1636 assert(is_aligned(s, os::vm_page_size()),
1637 "We can not protect if the yellow zone size is not page aligned.");
1638 assert(_stack_yellow_zone_size == 0, "This should be called only once.");
1639 _stack_yellow_zone_size = s;
1640 }
1641
1642 static size_t stack_reserved_zone_size() {
1643 // _stack_reserved_zone_size may be 0. This indicates the feature is off.
1644 return _stack_reserved_zone_size;
1645 }
1646 static void set_stack_reserved_zone_size(size_t s) {
1647 assert(is_aligned(s, os::vm_page_size()),
1648 "We can not protect if the reserved zone size is not page aligned.");
1649 assert(_stack_reserved_zone_size == 0, "This should be called only once.");
1650 _stack_reserved_zone_size = s;
1651 }
1652 address stack_reserved_zone_base() {
1653 return (address)(stack_end() +
1654 (stack_red_zone_size() + stack_yellow_zone_size() + stack_reserved_zone_size()));
1655 }
1656 bool in_stack_reserved_zone(address a) {
1657 return (a <= stack_reserved_zone_base()) &&
1658 (a >= (address)((intptr_t)stack_reserved_zone_base() - stack_reserved_zone_size()));
1659 }
1660
1661 static size_t stack_yellow_reserved_zone_size() {
1662 return _stack_yellow_zone_size + _stack_reserved_zone_size;
1663 }
1664 bool in_stack_yellow_reserved_zone(address a) {
1665 return (a <= stack_reserved_zone_base()) && (a >= stack_red_zone_base());
1666 }
1667
1668 // Size of red + yellow + reserved zones.
1669 static size_t stack_guard_zone_size() {
1670 return stack_red_zone_size() + stack_yellow_reserved_zone_size();
1671 }
1672
1673 static size_t stack_shadow_zone_size() {
1674 assert(_stack_shadow_zone_size > 0, "Don't call this before the field is initialized.");
1675 return _stack_shadow_zone_size;
1676 }
1677 static void set_stack_shadow_zone_size(size_t s) {
1678 // The shadow area is not allocated or protected, so
1679 // it needs not be page aligned.
1680 // But the stack bang currently assumes that it is a
1681 // multiple of page size. This guarantees that the bang
1682 // loop touches all pages in the shadow zone.
1683 // This can be guaranteed differently, as well. E.g., if
1684 // the page size is a multiple of 4K, banging in 4K steps
1685 // suffices to touch all pages. (Some pages are banged
1686 // several times, though.)
1687 assert(is_aligned(s, os::vm_page_size()),
1688 "Stack bang assumes multiple of page size.");
1689 assert(_stack_shadow_zone_size == 0, "This should be called only once.");
1690 _stack_shadow_zone_size = s;
1691 }
1692
1693 void create_stack_guard_pages();
1694 void remove_stack_guard_pages();
1695
1696 void enable_stack_reserved_zone();
1697 void disable_stack_reserved_zone();
1698 void enable_stack_yellow_reserved_zone();
1699 void disable_stack_yellow_reserved_zone();
1700 void enable_stack_red_zone();
1701 void disable_stack_red_zone();
1702
1703 inline bool stack_guard_zone_unused();
1704 inline bool stack_yellow_reserved_zone_disabled();
1705 inline bool stack_reserved_zone_disabled();
1706 inline bool stack_guards_enabled();
1707
1708 address reserved_stack_activation() const { return _reserved_stack_activation; }
1709 void set_reserved_stack_activation(address addr) {
1710 assert(_reserved_stack_activation == stack_base()
1711 || _reserved_stack_activation == NULL
1712 || addr == stack_base(), "Must not be set twice");
1713 _reserved_stack_activation = addr;
1714 }
1715
1716 // Attempt to reguard the stack after a stack overflow may have occurred.
1717 // Returns true if (a) guard pages are not needed on this thread, (b) the
1718 // pages are already guarded, or (c) the pages were successfully reguarded.
1719 // Returns false if there is not enough stack space to reguard the pages, in
1720 // which case the caller should unwind a frame and try again. The argument
1721 // should be the caller's (approximate) sp.
1722 bool reguard_stack(address cur_sp);
1723 // Similar to above but see if current stackpoint is out of the guard area
1724 // and reguard if possible.
1725 bool reguard_stack(void);
1726
1727 address stack_overflow_limit() { return _stack_overflow_limit; }
1728 void set_stack_overflow_limit() {
1729 _stack_overflow_limit =
1730 stack_end() + MAX2(JavaThread::stack_guard_zone_size(), JavaThread::stack_shadow_zone_size());
1731 }
1732
1733 // Check if address is in the usable part of the stack (excludes protected
1734 // guard pages). Can be applied to any thread and is an approximation for
1735 // using is_in_stack when the query has to happen from another thread.
1736 bool is_in_usable_stack(address adr) const;
1737
1738 // Misc. accessors/mutators
1739 void set_do_not_unlock(void) { _do_not_unlock_if_synchronized = true; }
1740 void clr_do_not_unlock(void) { _do_not_unlock_if_synchronized = false; }
1741 bool do_not_unlock(void) { return _do_not_unlock_if_synchronized; }
1742
1743 // For assembly stub generation
1744 static ByteSize threadObj_offset() { return byte_offset_of(JavaThread, _threadObj); }
1745 static ByteSize jni_environment_offset() { return byte_offset_of(JavaThread, _jni_environment); }
1746 static ByteSize pending_jni_exception_check_fn_offset() {
1747 return byte_offset_of(JavaThread, _pending_jni_exception_check_fn);
1748 }
1749 static ByteSize last_Java_sp_offset() {
1750 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
1751 }
1752 static ByteSize last_Java_pc_offset() {
1753 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
1754 }
1755 static ByteSize frame_anchor_offset() {
1756 return byte_offset_of(JavaThread, _anchor);
1757 }
1758 static ByteSize callee_target_offset() { return byte_offset_of(JavaThread, _callee_target); }
1759 static ByteSize vm_result_offset() { return byte_offset_of(JavaThread, _vm_result); }
1760 static ByteSize vm_result_2_offset() { return byte_offset_of(JavaThread, _vm_result_2); }
1761 static ByteSize thread_state_offset() { return byte_offset_of(JavaThread, _thread_state); }
1762 static ByteSize saved_exception_pc_offset() { return byte_offset_of(JavaThread, _saved_exception_pc); }
1763 static ByteSize osthread_offset() { return byte_offset_of(JavaThread, _osthread); }
1764 #if INCLUDE_JVMCI
1765 static ByteSize pending_deoptimization_offset() { return byte_offset_of(JavaThread, _pending_deoptimization); }
1766 static ByteSize pending_monitorenter_offset() { return byte_offset_of(JavaThread, _pending_monitorenter); }
1767 static ByteSize pending_failed_speculation_offset() { return byte_offset_of(JavaThread, _pending_failed_speculation); }
1768 static ByteSize jvmci_alternate_call_target_offset() { return byte_offset_of(JavaThread, _jvmci._alternate_call_target); }
1769 static ByteSize jvmci_implicit_exception_pc_offset() { return byte_offset_of(JavaThread, _jvmci._implicit_exception_pc); }
1770 static ByteSize jvmci_counters_offset() { return byte_offset_of(JavaThread, _jvmci_counters); }
1771 #endif // INCLUDE_JVMCI
1772 static ByteSize exception_oop_offset() { return byte_offset_of(JavaThread, _exception_oop); }
1773 static ByteSize exception_pc_offset() { return byte_offset_of(JavaThread, _exception_pc); }
1774 static ByteSize exception_handler_pc_offset() { return byte_offset_of(JavaThread, _exception_handler_pc); }
1775 static ByteSize stack_overflow_limit_offset() { return byte_offset_of(JavaThread, _stack_overflow_limit); }
1776 static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); }
1777 static ByteSize stack_guard_state_offset() { return byte_offset_of(JavaThread, _stack_guard_state); }
1778 static ByteSize reserved_stack_activation_offset() { return byte_offset_of(JavaThread, _reserved_stack_activation); }
1779 static ByteSize suspend_flags_offset() { return byte_offset_of(JavaThread, _suspend_flags); }
1780
1781 static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
1782 static ByteSize should_post_on_exceptions_flag_offset() {
1783 return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
1784 }
1785 static ByteSize doing_unsafe_access_offset() { return byte_offset_of(JavaThread, _doing_unsafe_access); }
1786
1787 // Returns the jni environment for this thread
1788 JNIEnv* jni_environment() { return &_jni_environment; }
1789
1790 static JavaThread* thread_from_jni_environment(JNIEnv* env) {
1791 JavaThread *thread_from_jni_env = (JavaThread*)((intptr_t)env - in_bytes(jni_environment_offset()));
1792 // Only return NULL if thread is off the thread list; starting to
1793 // exit should not return NULL.
1794 if (thread_from_jni_env->is_terminated()) {
1795 thread_from_jni_env->block_if_vm_exited();
1796 return NULL;
1797 } else {
1798 return thread_from_jni_env;
1799 }
1800 }
1801
1802 // JNI critical regions. These can nest.
1803 bool in_critical() { return _jni_active_critical > 0; }
1804 bool in_last_critical() { return _jni_active_critical == 1; }
1805 inline void enter_critical();
1806 void exit_critical() {
1807 assert(Thread::current() == this, "this must be current thread");
1808 _jni_active_critical--;
1809 assert(_jni_active_critical >= 0, "JNI critical nesting problem?");
1810 }
1811
1812 // Checked JNI: is the programmer required to check for exceptions, if so specify
1813 // which function name. Returning to a Java frame should implicitly clear the
1814 // pending check, this is done for Native->Java transitions (i.e. user JNI code).
1815 // VM->Java transistions are not cleared, it is expected that JNI code enclosed
1816 // within ThreadToNativeFromVM makes proper exception checks (i.e. VM internal).
1817 bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != NULL; }
1818 void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = NULL; }
1819 const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; }
1820 void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; }
1821
1822 // For deadlock detection
1823 int depth_first_number() { return _depth_first_number; }
1824 void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
1825
1826 private:
1827 void set_monitor_chunks(MonitorChunk* monitor_chunks) { _monitor_chunks = monitor_chunks; }
1828
1829 public:
1830 MonitorChunk* monitor_chunks() const { return _monitor_chunks; }
1831 void add_monitor_chunk(MonitorChunk* chunk);
1832 void remove_monitor_chunk(MonitorChunk* chunk);
1833 bool in_deopt_handler() const { return _in_deopt_handler > 0; }
1834 void inc_in_deopt_handler() { _in_deopt_handler++; }
1835 void dec_in_deopt_handler() {
1836 assert(_in_deopt_handler > 0, "mismatched deopt nesting");
1837 if (_in_deopt_handler > 0) { // robustness
1838 _in_deopt_handler--;
1839 }
1840 }
1841
1842 private:
1843 void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
1844
1845 public:
1846
1847 // Frame iteration; calls the function f for all frames on the stack
1848 void frames_do(void f(frame*, const RegisterMap*));
1849
1850 // Memory operations
1851 void oops_do(OopClosure* f, CodeBlobClosure* cf);
1852
1853 // Sweeper operations
1854 virtual void nmethods_do(CodeBlobClosure* cf);
1855
1856 // RedefineClasses Support
1857 void metadata_do(MetadataClosure* f);
1858
1859 // Debug method asserting thread states are correct during a handshake operation.
1860 DEBUG_ONLY(void verify_states_for_handshake();)
1861
1862 // Misc. operations
1863 char* name() const { return (char*)get_thread_name(); }
1864 void print_on(outputStream* st, bool print_extended_info) const;
1865 void print_on(outputStream* st) const { print_on(st, false); }
1866 void print() const;
1867 void print_thread_state_on(outputStream*) const PRODUCT_RETURN;
1868 void print_on_error(outputStream* st, char* buf, int buflen) const;
1869 void print_name_on_error(outputStream* st, char* buf, int buflen) const;
1870 void verify();
1871 const char* get_thread_name() const;
1872 protected:
1873 // factor out low-level mechanics for use in both normal and error cases
1874 virtual const char* get_thread_name_string(char* buf = NULL, int buflen = 0) const;
1875 public:
1876 // Accessing frames
1877 frame last_frame() {
1878 _anchor.make_walkable(this);
1879 return pd_last_frame();
1880 }
1881 javaVFrame* last_java_vframe(RegisterMap* reg_map);
1882
1883 // Returns method at 'depth' java or native frames down the stack
1884 // Used for security checks
1885 Klass* security_get_caller_class(int depth);
1886
1887 // Print stack trace in external format
1888 void print_stack_on(outputStream* st);
1889 void print_stack() { print_stack_on(tty); }
1890
1891 // Print stack traces in various internal formats
1892 void trace_stack() PRODUCT_RETURN;
1893 void trace_stack_from(vframe* start_vf) PRODUCT_RETURN;
1894 void trace_frames() PRODUCT_RETURN;
1895
1896 // Print an annotated view of the stack frames
1897 void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN;
1898 void validate_frame_layout() {
1899 print_frame_layout(0, true);
1900 }
1901
1902 // Function for testing deoptimization
1903 void deoptimize();
1904 void make_zombies();
1905
1906 void deoptimize_marked_methods();
1907
1908 public:
1909 // Returns the running thread as a JavaThread
1910 static inline JavaThread* current();
1911
1912 // Returns the active Java thread. Do not use this if you know you are calling
1913 // from a JavaThread, as it's slower than JavaThread::current. If called from
1914 // the VMThread, it also returns the JavaThread that instigated the VMThread's
1915 // operation. You may not want that either.
1916 static JavaThread* active();
1917
1918 inline CompilerThread* as_CompilerThread();
1919
1920 protected:
1921 virtual void pre_run();
1922 virtual void run();
1923 void thread_main_inner();
1924 virtual void post_run();
1925
1926
1927 private:
1928 GrowableArray<oop>* _array_for_gc;
1929 public:
1930
1931 void register_array_for_gc(GrowableArray<oop>* array) { _array_for_gc = array; }
1932
1933 public:
1934 // Thread local information maintained by JVMTI.
1935 void set_jvmti_thread_state(JvmtiThreadState *value) { _jvmti_thread_state = value; }
1936 // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1937 // getter is used to get this JavaThread's JvmtiThreadState if it has
1938 // one which means NULL can be returned. JvmtiThreadState::state_for()
1939 // is used to get the specified JavaThread's JvmtiThreadState if it has
1940 // one or it allocates a new JvmtiThreadState for the JavaThread and
1941 // returns it. JvmtiThreadState::state_for() will return NULL only if
1942 // the specified JavaThread is exiting.
1943 JvmtiThreadState *jvmti_thread_state() const { return _jvmti_thread_state; }
1944 static ByteSize jvmti_thread_state_offset() { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1945
1946 // JVMTI PopFrame support
1947 // Setting and clearing popframe_condition
1948 // All of these enumerated values are bits. popframe_pending
1949 // indicates that a PopFrame() has been requested and not yet been
1950 // completed. popframe_processing indicates that that PopFrame() is in
1951 // the process of being completed. popframe_force_deopt_reexecution_bit
1952 // indicates that special handling is required when returning to a
1953 // deoptimized caller.
1954 enum PopCondition {
1955 popframe_inactive = 0x00,
1956 popframe_pending_bit = 0x01,
1957 popframe_processing_bit = 0x02,
1958 popframe_force_deopt_reexecution_bit = 0x04
1959 };
1960 PopCondition popframe_condition() { return (PopCondition) _popframe_condition; }
1961 void set_popframe_condition(PopCondition c) { _popframe_condition = c; }
1962 void set_popframe_condition_bit(PopCondition c) { _popframe_condition |= c; }
1963 void clear_popframe_condition() { _popframe_condition = popframe_inactive; }
1964 static ByteSize popframe_condition_offset() { return byte_offset_of(JavaThread, _popframe_condition); }
1965 bool has_pending_popframe() { return (popframe_condition() & popframe_pending_bit) != 0; }
1966 bool popframe_forcing_deopt_reexecution() { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
1967 void clear_popframe_forcing_deopt_reexecution() { _popframe_condition &= ~popframe_force_deopt_reexecution_bit; }
1968 #ifdef CC_INTERP
1969 bool pop_frame_pending(void) { return ((_popframe_condition & popframe_pending_bit) != 0); }
1970 void clr_pop_frame_pending(void) { _popframe_condition = popframe_inactive; }
1971 bool pop_frame_in_process(void) { return ((_popframe_condition & popframe_processing_bit) != 0); }
1972 void set_pop_frame_in_process(void) { _popframe_condition |= popframe_processing_bit; }
1973 void clr_pop_frame_in_process(void) { _popframe_condition &= ~popframe_processing_bit; }
1974 #endif
1975
1976 int frames_to_pop_failed_realloc() const { return _frames_to_pop_failed_realloc; }
1977 void set_frames_to_pop_failed_realloc(int nb) { _frames_to_pop_failed_realloc = nb; }
1978 void dec_frames_to_pop_failed_realloc() { _frames_to_pop_failed_realloc--; }
1979
1980 private:
1981 // Saved incoming arguments to popped frame.
1982 // Used only when popped interpreted frame returns to deoptimized frame.
1983 void* _popframe_preserved_args;
1984 int _popframe_preserved_args_size;
1985
1986 public:
1987 void popframe_preserve_args(ByteSize size_in_bytes, void* start);
1988 void* popframe_preserved_args();
1989 ByteSize popframe_preserved_args_size();
1990 WordSize popframe_preserved_args_size_in_words();
1991 void popframe_free_preserved_args();
1992
1993
1994 private:
1995 JvmtiThreadState *_jvmti_thread_state;
1996
1997 // Used by the interpreter in fullspeed mode for frame pop, method
1998 // entry, method exit and single stepping support. This field is
1999 // only set to non-zero by the VM_EnterInterpOnlyMode VM operation.
2000 // It can be set to zero asynchronously (i.e., without a VM operation
2001 // or a lock) so we have to be very careful.
2002 int _interp_only_mode;
2003
2004 public:
2005 // used by the interpreter for fullspeed debugging support (see above)
2006 static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
2007 bool is_interp_only_mode() { return (_interp_only_mode != 0); }
2008 int get_interp_only_mode() { return _interp_only_mode; }
2009 void increment_interp_only_mode() { ++_interp_only_mode; }
2010 void decrement_interp_only_mode() { --_interp_only_mode; }
2011
2012 // support for cached flag that indicates whether exceptions need to be posted for this thread
2013 // if this is false, we can avoid deoptimizing when events are thrown
2014 // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
2015 private:
2016 int _should_post_on_exceptions_flag;
2017
2018 public:
2019 int should_post_on_exceptions_flag() { return _should_post_on_exceptions_flag; }
2020 void set_should_post_on_exceptions_flag(int val) { _should_post_on_exceptions_flag = val; }
2021
2022 private:
2023 ThreadStatistics *_thread_stat;
2024
2025 public:
2026 ThreadStatistics* get_thread_stat() const { return _thread_stat; }
2027
2028 // Return a blocker object for which this thread is blocked parking.
2029 oop current_park_blocker();
2030
2031 private:
2032 static size_t _stack_size_at_create;
2033
2034 public:
2035 static inline size_t stack_size_at_create(void) {
2036 return _stack_size_at_create;
2037 }
2038 static inline void set_stack_size_at_create(size_t value) {
2039 _stack_size_at_create = value;
2040 }
2041
2042 // Machine dependent stuff
2043 #include OS_CPU_HEADER(thread)
2044
2045 // JSR166 per-thread parker
2046 private:
2047 Parker* _parker;
2048 public:
2049 Parker* parker() { return _parker; }
2050
2051 // Biased locking support
2052 private:
2053 GrowableArray<MonitorInfo*>* _cached_monitor_info;
2054 public:
2055 GrowableArray<MonitorInfo*>* cached_monitor_info() { return _cached_monitor_info; }
2056 void set_cached_monitor_info(GrowableArray<MonitorInfo*>* info) { _cached_monitor_info = info; }
2057
2058 // clearing/querying jni attach status
2059 bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; }
2060 bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
2061 inline void set_done_attaching_via_jni();
2062
2063 // Stack dump assistance:
2064 // Track the class we want to initialize but for which we have to wait
2065 // on its init_lock() because it is already being initialized.
2066 void set_class_to_be_initialized(InstanceKlass* k);
2067 InstanceKlass* class_to_be_initialized() const;
2068
2069 private:
2070 InstanceKlass* _class_to_be_initialized;
2071
2072 // java.lang.Thread.sleep support
2073 ParkEvent * _SleepEvent;
2074 public:
2075 bool sleep(jlong millis);
2076
2077 // java.lang.Thread interruption support
2078 void interrupt();
2079 bool is_interrupted(bool clear_interrupted);
2080
2081 };
2082
2083 // Inline implementation of JavaThread::current
2084 inline JavaThread* JavaThread::current() {
2085 Thread* thread = Thread::current();
2086 assert(thread->is_Java_thread(), "just checking");
2087 return (JavaThread*)thread;
2088 }
2089
2090 inline CompilerThread* JavaThread::as_CompilerThread() {
2091 assert(is_Compiler_thread(), "just checking");
2092 return (CompilerThread*)this;
2093 }
2094
2095 // Dedicated thread to sweep the code cache
2096 class CodeCacheSweeperThread : public JavaThread {
2097 CompiledMethod* _scanned_compiled_method; // nmethod being scanned by the sweeper
2098 public:
2099 CodeCacheSweeperThread();
2100 // Track the nmethod currently being scanned by the sweeper
2101 void set_scanned_compiled_method(CompiledMethod* cm) {
2102 assert(_scanned_compiled_method == NULL || cm == NULL, "should reset to NULL before writing a new value");
2103 _scanned_compiled_method = cm;
2104 }
2105
2106 // Hide sweeper thread from external view.
2107 bool is_hidden_from_external_view() const { return true; }
2108
2109 bool is_Code_cache_sweeper_thread() const { return true; }
2110
2111 // Prevent GC from unloading _scanned_compiled_method
2112 void oops_do(OopClosure* f, CodeBlobClosure* cf);
2113 void nmethods_do(CodeBlobClosure* cf);
2114 };
2115
2116 // A thread used for Compilation.
2117 class CompilerThread : public JavaThread {
2118 friend class VMStructs;
2119 private:
2120 CompilerCounters* _counters;
2121
2122 ciEnv* _env;
2123 CompileLog* _log;
2124 CompileTask* volatile _task; // print_threads_compiling can read this concurrently.
2125 CompileQueue* _queue;
2126 BufferBlob* _buffer_blob;
2127
2128 AbstractCompiler* _compiler;
2129 TimeStamp _idle_time;
2130
2131 public:
2132
2133 static CompilerThread* current();
2134
2135 CompilerThread(CompileQueue* queue, CompilerCounters* counters);
2136 ~CompilerThread();
2137
2138 bool is_Compiler_thread() const { return true; }
2139
2140 virtual bool can_call_java() const;
2141
2142 // Hide native compiler threads from external view.
2143 bool is_hidden_from_external_view() const { return !can_call_java(); }
2144
2145 void set_compiler(AbstractCompiler* c) { _compiler = c; }
2146 AbstractCompiler* compiler() const { return _compiler; }
2147
2148 CompileQueue* queue() const { return _queue; }
2149 CompilerCounters* counters() const { return _counters; }
2150
2151 // Get/set the thread's compilation environment.
2152 ciEnv* env() { return _env; }
2153 void set_env(ciEnv* env) { _env = env; }
2154
2155 BufferBlob* get_buffer_blob() const { return _buffer_blob; }
2156 void set_buffer_blob(BufferBlob* b) { _buffer_blob = b; }
2157
2158 // Get/set the thread's logging information
2159 CompileLog* log() { return _log; }
2160 void init_log(CompileLog* log) {
2161 // Set once, for good.
2162 assert(_log == NULL, "set only once");
2163 _log = log;
2164 }
2165
2166 void start_idle_timer() { _idle_time.update(); }
2167 jlong idle_time_millis() {
2168 return TimeHelper::counter_to_millis(_idle_time.ticks_since_update());
2169 }
2170
2171 #ifndef PRODUCT
2172 private:
2173 IdealGraphPrinter *_ideal_graph_printer;
2174 public:
2175 IdealGraphPrinter *ideal_graph_printer() { return _ideal_graph_printer; }
2176 void set_ideal_graph_printer(IdealGraphPrinter *n) { _ideal_graph_printer = n; }
2177 #endif
2178
2179 // Get/set the thread's current task
2180 CompileTask* task() { return _task; }
2181 void set_task(CompileTask* task) { _task = task; }
2182 };
2183
2184 inline CompilerThread* CompilerThread::current() {
2185 return JavaThread::current()->as_CompilerThread();
2186 }
2187
2188 // The active thread queue. It also keeps track of the current used
2189 // thread priorities.
2190 class Threads: AllStatic {
2191 friend class VMStructs;
2192 private:
2193 static int _number_of_threads;
2194 static int _number_of_non_daemon_threads;
2195 static int _return_code;
2196 static uintx _thread_claim_token;
2197 #ifdef ASSERT
2198 static bool _vm_complete;
2199 #endif
2200
2201 static void initialize_java_lang_classes(JavaThread* main_thread, TRAPS);
2202 static void initialize_jsr292_core_classes(TRAPS);
2203
2204 public:
2205 // Thread management
2206 // force_daemon is a concession to JNI, where we may need to add a
2207 // thread to the thread list before allocating its thread object
2208 static void add(JavaThread* p, bool force_daemon = false);
2209 static void remove(JavaThread* p, bool is_daemon);
2210 static void non_java_threads_do(ThreadClosure* tc);
2211 static void java_threads_do(ThreadClosure* tc);
2212 static void java_threads_and_vm_thread_do(ThreadClosure* tc);
2213 static void threads_do(ThreadClosure* tc);
2214 static void possibly_parallel_threads_do(bool is_par, ThreadClosure* tc);
2215
2216 // Initializes the vm and creates the vm thread
2217 static jint create_vm(JavaVMInitArgs* args, bool* canTryAgain);
2218 static void convert_vm_init_libraries_to_agents();
2219 static void create_vm_init_libraries();
2220 static void create_vm_init_agents();
2221 static void shutdown_vm_agents();
2222 static bool destroy_vm();
2223 // Supported VM versions via JNI
2224 // Includes JNI_VERSION_1_1
2225 static jboolean is_supported_jni_version_including_1_1(jint version);
2226 // Does not include JNI_VERSION_1_1
2227 static jboolean is_supported_jni_version(jint version);
2228
2229 // The "thread claim token" provides a way for threads to be claimed
2230 // by parallel worker tasks.
2231 //
2232 // Each thread contains a "token" field. A task will claim the
2233 // thread only if its token is different from the global token,
2234 // which is updated by calling change_thread_claim_token(). When
2235 // a thread is claimed, it's token is set to the global token value
2236 // so other threads in the same iteration pass won't claim it.
2237 //
2238 // For this to work change_thread_claim_token() needs to be called
2239 // exactly once in sequential code before starting parallel tasks
2240 // that should claim threads.
2241 //
2242 // New threads get their token set to 0 and change_thread_claim_token()
2243 // never sets the global token to 0.
2244 static uintx thread_claim_token() { return _thread_claim_token; }
2245 static void change_thread_claim_token();
2246 static void assert_all_threads_claimed() NOT_DEBUG_RETURN;
2247
2248 // Apply "f->do_oop" to all root oops in all threads.
2249 // This version may only be called by sequential code.
2250 static void oops_do(OopClosure* f, CodeBlobClosure* cf);
2251 // This version may be called by sequential or parallel code.
2252 static void possibly_parallel_oops_do(bool is_par, OopClosure* f, CodeBlobClosure* cf);
2253
2254 // Sweeper
2255 static void nmethods_do(CodeBlobClosure* cf);
2256
2257 // RedefineClasses support
2258 static void metadata_do(MetadataClosure* f);
2259 static void metadata_handles_do(void f(Metadata*));
2260
2261 #ifdef ASSERT
2262 static bool is_vm_complete() { return _vm_complete; }
2263 #endif // ASSERT
2264
2265 // Verification
2266 static void verify();
2267 static void print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks, bool print_extended_info);
2268 static void print(bool print_stacks, bool internal_format) {
2269 // this function is only used by debug.cpp
2270 print_on(tty, print_stacks, internal_format, false /* no concurrent lock printed */, false /* simple format */);
2271 }
2272 static void print_on_error(outputStream* st, Thread* current, char* buf, int buflen);
2273 static void print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
2274 int buflen, bool* found_current);
2275 static void print_threads_compiling(outputStream* st, char* buf, int buflen, bool short_form = false);
2276
2277 // Get Java threads that are waiting to enter a monitor.
2278 static GrowableArray<JavaThread*>* get_pending_threads(ThreadsList * t_list,
2279 int count, address monitor);
2280
2281 // Get owning Java thread from the monitor's owner field.
2282 static JavaThread *owning_thread_from_monitor_owner(ThreadsList * t_list,
2283 address owner);
2284
2285 // Number of threads on the active threads list
2286 static int number_of_threads() { return _number_of_threads; }
2287 // Number of non-daemon threads on the active threads list
2288 static int number_of_non_daemon_threads() { return _number_of_non_daemon_threads; }
2289
2290 // Deoptimizes all frames tied to marked nmethods
2291 static void deoptimized_wrt_marked_nmethods();
2292
2293 struct Test; // For private gtest access.
2294 };
2295
2296 class SignalHandlerMark: public StackObj {
2297 private:
2298 Thread* _thread;
2299 public:
2300 SignalHandlerMark(Thread* t) {
2301 _thread = t;
2302 if (_thread) _thread->enter_signal_handler();
2303 }
2304 ~SignalHandlerMark() {
2305 if (_thread) _thread->leave_signal_handler();
2306 _thread = NULL;
2307 }
2308 };
2309
2310
2311 #endif // SHARE_RUNTIME_THREAD_HPP