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(ObjectMonitorHandle* omh_p) {
628 if (omh_p->save_om_ptr_if_safe(_current_pending_monitor)) {
629 return omh_p->om_ptr(); // Return the safe ObjectMonitor*.
630 }
631 return NULL;
632 }
633 void set_current_pending_monitor(ObjectMonitor* monitor) {
634 ObjectMonitor* saved_cur = NULL;
635 if (monitor != NULL) {
636 monitor->inc_ref_count(); // Protect the ObjectMonitor* we're about to cache.
637 } else {
638 saved_cur = _current_pending_monitor;
639 }
640 _current_pending_monitor = monitor;
641 if (saved_cur != NULL) {
642 saved_cur->dec_ref_count(); // Cleared the cached ObjectMonitor*.
643 }
644 }
645 void set_current_pending_monitor_is_from_java(bool from_java) {
646 _current_pending_monitor_is_from_java = from_java;
647 }
648 bool current_pending_monitor_is_from_java() {
649 return _current_pending_monitor_is_from_java;
650 }
651
652 // For tracking the ObjectMonitor on which this thread called Object.wait()
653 ObjectMonitor* current_waiting_monitor(ObjectMonitorHandle* omh_p) {
654 if (omh_p->save_om_ptr_if_safe(_current_waiting_monitor)) {
655 return omh_p->om_ptr(); // Return the safe ObjectMonitor*.
656 }
657 return NULL;
658 }
659 void set_current_waiting_monitor(ObjectMonitor* monitor) {
660 ObjectMonitor* saved_cur = NULL;
661 if (monitor != NULL) {
662 monitor->inc_ref_count(); // Protect the ObjectMonitor* we're about to cache.
663 } else {
664 saved_cur = _current_waiting_monitor;
665 }
666 _current_waiting_monitor = monitor;
667 if (saved_cur != NULL) {
668 saved_cur->dec_ref_count(); // Cleared the cached ObjectMonitor*.
669 }
670 }
671
672 // For tracking the Jvmti raw monitor the thread is pending on.
673 JvmtiRawMonitor* current_pending_raw_monitor() {
674 return _current_pending_raw_monitor;
675 }
676 void set_current_pending_raw_monitor(JvmtiRawMonitor* monitor) {
677 _current_pending_raw_monitor = monitor;
678 }
679
680 // GC support
681 // Apply "f->do_oop" to all root oops in "this".
682 // Used by JavaThread::oops_do.
683 // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames
684 virtual void oops_do(OopClosure* f, CodeBlobClosure* cf);
685
686 // Handles the parallel case for claim_threads_do.
687 private:
688 bool claim_par_threads_do(uintx claim_token);
689 public:
690 // Requires that "claim_token" is that of the current iteration.
691 // If "is_par" is false, sets the token of "this" to
692 // "claim_token", and returns "true". If "is_par" is true,
693 // uses an atomic instruction to set the current thread's token to
694 // "claim_token", if it is not already. Returns "true" iff the
695 // calling thread does the update, this indicates that the calling thread
696 // has claimed the thread in the current iteration.
697 bool claim_threads_do(bool is_par, uintx claim_token) {
698 if (!is_par) {
699 _threads_do_token = claim_token;
700 return true;
701 } else {
702 return claim_par_threads_do(claim_token);
703 }
704 }
705
706 uintx threads_do_token() const { return _threads_do_token; }
707
708 // jvmtiRedefineClasses support
709 void metadata_handles_do(void f(Metadata*));
710
711 // Used by fast lock support
712 virtual bool is_lock_owned(address adr) const;
713
714 // Check if address is in the live stack of this thread (not just for locks).
715 // Warning: can only be called by the current thread on itself.
716 bool is_in_stack(address adr) const;
717
718 // Check if address in the stack mapped to this thread. Used mainly in
719 // error reporting (so has to include guard zone) and frame printing.
720 bool on_local_stack(address adr) const {
721 return (_stack_base > adr && adr >= stack_end());
722 }
723
724 // Sets this thread as starting thread. Returns failure if thread
725 // creation fails due to lack of memory, too many threads etc.
726 bool set_as_starting_thread();
727
728 protected:
729 // OS data associated with the thread
730 OSThread* _osthread; // Platform-specific thread information
731
732 // Thread local resource area for temporary allocation within the VM
733 ResourceArea* _resource_area;
734
735 DEBUG_ONLY(ResourceMark* _current_resource_mark;)
736
737 // Thread local handle area for allocation of handles within the VM
738 HandleArea* _handle_area;
739 GrowableArray<Metadata*>* _metadata_handles;
740
741 // Support for stack overflow handling, get_thread, etc.
742 address _stack_base;
743 size_t _stack_size;
744 int _lgrp_id;
745
746 volatile void** polling_page_addr() { return &_polling_page; }
747
748 public:
749 // Stack overflow support
750 address stack_base() const { assert(_stack_base != NULL,"Sanity check"); return _stack_base; }
751 void set_stack_base(address base) { _stack_base = base; }
752 size_t stack_size() const { return _stack_size; }
753 void set_stack_size(size_t size) { _stack_size = size; }
754 address stack_end() const { return stack_base() - stack_size(); }
755 void record_stack_base_and_size();
756 void register_thread_stack_with_NMT() NOT_NMT_RETURN;
757
758 int lgrp_id() const { return _lgrp_id; }
759 void set_lgrp_id(int value) { _lgrp_id = value; }
760
761 // Printing
762 void print_on(outputStream* st, bool print_extended_info) const;
763 virtual void print_on(outputStream* st) const { print_on(st, false); }
764 void print() const;
765 virtual void print_on_error(outputStream* st, char* buf, int buflen) const;
766 void print_value_on(outputStream* st) const;
767
768 // Debug-only code
769 #ifdef ASSERT
770 private:
771 // Deadlock detection support for Mutex locks. List of locks own by thread.
772 Mutex* _owned_locks;
773 // Mutex::set_owner_implementation is the only place where _owned_locks is modified,
774 // thus the friendship
775 friend class Mutex;
776 friend class Monitor;
777
778 public:
779 void print_owned_locks_on(outputStream* st) const;
780 void print_owned_locks() const { print_owned_locks_on(tty); }
781 Mutex* owned_locks() const { return _owned_locks; }
782 bool owns_locks() const { return owned_locks() != NULL; }
783
784 // Deadlock detection
785 ResourceMark* current_resource_mark() { return _current_resource_mark; }
786 void set_current_resource_mark(ResourceMark* rm) { _current_resource_mark = rm; }
787 #endif // ASSERT
788
789 // These functions check conditions on a JavaThread before possibly going to a safepoint,
790 // including NoSafepointVerifier.
791 void check_for_valid_safepoint_state() NOT_DEBUG_RETURN;
792 void check_possible_safepoint() NOT_DEBUG_RETURN;
793
794 private:
795 volatile int _jvmti_env_iteration_count;
796
797 public:
798 void entering_jvmti_env_iteration() { ++_jvmti_env_iteration_count; }
799 void leaving_jvmti_env_iteration() { --_jvmti_env_iteration_count; }
800 bool is_inside_jvmti_env_iteration() { return _jvmti_env_iteration_count > 0; }
801
802 // Code generation
803 static ByteSize exception_file_offset() { return byte_offset_of(Thread, _exception_file); }
804 static ByteSize exception_line_offset() { return byte_offset_of(Thread, _exception_line); }
805 static ByteSize active_handles_offset() { return byte_offset_of(Thread, _active_handles); }
806
807 static ByteSize stack_base_offset() { return byte_offset_of(Thread, _stack_base); }
808 static ByteSize stack_size_offset() { return byte_offset_of(Thread, _stack_size); }
809
810 static ByteSize polling_page_offset() { return byte_offset_of(Thread, _polling_page); }
811
812 static ByteSize tlab_start_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::start_offset(); }
813 static ByteSize tlab_end_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::end_offset(); }
814 static ByteSize tlab_top_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::top_offset(); }
815 static ByteSize tlab_pf_top_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::pf_top_offset(); }
816
817 static ByteSize allocated_bytes_offset() { return byte_offset_of(Thread, _allocated_bytes); }
818
819 JFR_ONLY(DEFINE_THREAD_LOCAL_OFFSET_JFR;)
820
821 public:
822 volatile intptr_t _Stalled;
823 volatile int _TypeTag;
824 ParkEvent * _ParkEvent; // for Object monitors and JVMTI raw monitors
825 ParkEvent * _MuxEvent; // for low-level muxAcquire-muxRelease
826 int NativeSyncRecursion; // diagnostic
827
828 volatile int _OnTrap; // Resume-at IP delta
829 jint _hashStateW; // Marsaglia Shift-XOR thread-local RNG
830 jint _hashStateX; // thread-specific hashCode generator state
831 jint _hashStateY;
832 jint _hashStateZ;
833
834 // Low-level leaf-lock primitives used to implement synchronization
835 // and native monitor-mutex infrastructure.
836 // Not for general synchronization use.
837 static void SpinAcquire(volatile int * Lock, const char * Name);
838 static void SpinRelease(volatile int * Lock);
839 static void muxAcquire(volatile intptr_t * Lock, const char * Name);
840 static void muxRelease(volatile intptr_t * Lock);
841 };
842
843 // Inline implementation of Thread::current()
844 inline Thread* Thread::current() {
845 Thread* current = current_or_null();
846 assert(current != NULL, "Thread::current() called on detached thread");
847 return current;
848 }
849
850 inline Thread* Thread::current_or_null() {
851 #ifndef USE_LIBRARY_BASED_TLS_ONLY
852 return _thr_current;
853 #else
854 if (ThreadLocalStorage::is_initialized()) {
855 return ThreadLocalStorage::thread();
856 }
857 return NULL;
858 #endif
859 }
860
861 inline Thread* Thread::current_or_null_safe() {
862 if (ThreadLocalStorage::is_initialized()) {
863 return ThreadLocalStorage::thread();
864 }
865 return NULL;
866 }
867
868 class NonJavaThread: public Thread {
869 friend class VMStructs;
870
871 NonJavaThread* volatile _next;
872
873 class List;
874 static List _the_list;
875
876 void add_to_the_list();
877 void remove_from_the_list();
878
879 protected:
880 virtual void pre_run();
881 virtual void post_run();
882
883 public:
884 NonJavaThread();
885 ~NonJavaThread();
886
887 class Iterator;
888 };
889
890 // Provides iteration over the list of NonJavaThreads.
891 // List addition occurs in pre_run(), and removal occurs in post_run(),
892 // so that only live fully-initialized threads can be found in the list.
893 // Threads created after an iterator is constructed will not be visited
894 // by the iterator. The scope of an iterator is a critical section; there
895 // must be no safepoint checks in that scope.
896 class NonJavaThread::Iterator : public StackObj {
897 uint _protect_enter;
898 NonJavaThread* _current;
899
900 NONCOPYABLE(Iterator);
901
902 public:
903 Iterator();
904 ~Iterator();
905
906 bool end() const { return _current == NULL; }
907 NonJavaThread* current() const { return _current; }
908 void step();
909 };
910
911 // Name support for threads. non-JavaThread subclasses with multiple
912 // uniquely named instances should derive from this.
913 class NamedThread: public NonJavaThread {
914 friend class VMStructs;
915 enum {
916 max_name_len = 64
917 };
918 private:
919 char* _name;
920 // log JavaThread being processed by oops_do
921 JavaThread* _processed_thread;
922 uint _gc_id; // The current GC id when a thread takes part in GC
923
924 public:
925 NamedThread();
926 ~NamedThread();
927 // May only be called once per thread.
928 void set_name(const char* format, ...) ATTRIBUTE_PRINTF(2, 3);
929 virtual bool is_Named_thread() const { return true; }
930 virtual char* name() const { return _name == NULL ? (char*)"Unknown Thread" : _name; }
931 JavaThread *processed_thread() { return _processed_thread; }
932 void set_processed_thread(JavaThread *thread) { _processed_thread = thread; }
933 virtual void print_on(outputStream* st) const;
934
935 void set_gc_id(uint gc_id) { _gc_id = gc_id; }
936 uint gc_id() { return _gc_id; }
937 };
938
939 // Worker threads are named and have an id of an assigned work.
940 class WorkerThread: public NamedThread {
941 private:
942 uint _id;
943 public:
944 WorkerThread() : _id(0) { }
945 virtual bool is_Worker_thread() const { return true; }
946
947 virtual WorkerThread* as_Worker_thread() const {
948 assert(is_Worker_thread(), "Dubious cast to WorkerThread*?");
949 return (WorkerThread*) this;
950 }
951
952 void set_id(uint work_id) { _id = work_id; }
953 uint id() const { return _id; }
954 };
955
956 // A single WatcherThread is used for simulating timer interrupts.
957 class WatcherThread: public NonJavaThread {
958 friend class VMStructs;
959 protected:
960 virtual void run();
961
962 private:
963 static WatcherThread* _watcher_thread;
964
965 static bool _startable;
966 // volatile due to at least one lock-free read
967 volatile static bool _should_terminate;
968 public:
969 enum SomeConstants {
970 delay_interval = 10 // interrupt delay in milliseconds
971 };
972
973 // Constructor
974 WatcherThread();
975
976 // No destruction allowed
977 ~WatcherThread() {
978 guarantee(false, "WatcherThread deletion must fix the race with VM termination");
979 }
980
981 // Tester
982 bool is_Watcher_thread() const { return true; }
983
984 // Printing
985 char* name() const { return (char*)"VM Periodic Task Thread"; }
986 void print_on(outputStream* st) const;
987 void unpark();
988
989 // Returns the single instance of WatcherThread
990 static WatcherThread* watcher_thread() { return _watcher_thread; }
991
992 // Create and start the single instance of WatcherThread, or stop it on shutdown
993 static void start();
994 static void stop();
995 // Only allow start once the VM is sufficiently initialized
996 // Otherwise the first task to enroll will trigger the start
997 static void make_startable();
998 private:
999 int sleep() const;
1000 };
1001
1002
1003 class CompilerThread;
1004
1005 typedef void (*ThreadFunction)(JavaThread*, TRAPS);
1006
1007 class JavaThread: public Thread {
1008 friend class VMStructs;
1009 friend class JVMCIVMStructs;
1010 friend class WhiteBox;
1011 private:
1012 bool _on_thread_list; // Is set when this JavaThread is added to the Threads list
1013 oop _threadObj; // The Java level thread object
1014
1015 #ifdef ASSERT
1016 private:
1017 int _java_call_counter;
1018
1019 public:
1020 int java_call_counter() { return _java_call_counter; }
1021 void inc_java_call_counter() { _java_call_counter++; }
1022 void dec_java_call_counter() {
1023 assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
1024 _java_call_counter--;
1025 }
1026 private: // restore original namespace restriction
1027 #endif // ifdef ASSERT
1028
1029 #ifndef PRODUCT
1030 public:
1031 enum {
1032 jump_ring_buffer_size = 16
1033 };
1034 private: // restore original namespace restriction
1035 #endif
1036
1037 JavaFrameAnchor _anchor; // Encapsulation of current java frame and it state
1038
1039 ThreadFunction _entry_point;
1040
1041 JNIEnv _jni_environment;
1042
1043 // Deopt support
1044 DeoptResourceMark* _deopt_mark; // Holds special ResourceMark for deoptimization
1045
1046 CompiledMethod* _deopt_nmethod; // CompiledMethod that is currently being deoptimized
1047 vframeArray* _vframe_array_head; // Holds the heap of the active vframeArrays
1048 vframeArray* _vframe_array_last; // Holds last vFrameArray we popped
1049 // Because deoptimization is lazy we must save jvmti requests to set locals
1050 // in compiled frames until we deoptimize and we have an interpreter frame.
1051 // This holds the pointer to array (yeah like there might be more than one) of
1052 // description of compiled vframes that have locals that need to be updated.
1053 GrowableArray<jvmtiDeferredLocalVariableSet*>* _deferred_locals_updates;
1054
1055 // Handshake value for fixing 6243940. We need a place for the i2c
1056 // adapter to store the callee Method*. This value is NEVER live
1057 // across a gc point so it does NOT have to be gc'd
1058 // The handshake is open ended since we can't be certain that it will
1059 // be NULLed. This is because we rarely ever see the race and end up
1060 // in handle_wrong_method which is the backend of the handshake. See
1061 // code in i2c adapters and handle_wrong_method.
1062
1063 Method* _callee_target;
1064
1065 // Used to pass back results to the interpreter or generated code running Java code.
1066 oop _vm_result; // oop result is GC-preserved
1067 Metadata* _vm_result_2; // non-oop result
1068
1069 // See ReduceInitialCardMarks: this holds the precise space interval of
1070 // the most recent slow path allocation for which compiled code has
1071 // elided card-marks for performance along the fast-path.
1072 MemRegion _deferred_card_mark;
1073
1074 MonitorChunk* _monitor_chunks; // Contains the off stack monitors
1075 // allocated during deoptimization
1076 // and by JNI_MonitorEnter/Exit
1077
1078 // Async. requests support
1079 enum AsyncRequests {
1080 _no_async_condition = 0,
1081 _async_exception,
1082 _async_unsafe_access_error
1083 };
1084 AsyncRequests _special_runtime_exit_condition; // Enum indicating pending async. request
1085 oop _pending_async_exception;
1086
1087 // Safepoint support
1088 public: // Expose _thread_state for SafeFetchInt()
1089 volatile JavaThreadState _thread_state;
1090 private:
1091 ThreadSafepointState* _safepoint_state; // Holds information about a thread during a safepoint
1092 address _saved_exception_pc; // Saved pc of instruction where last implicit exception happened
1093
1094 // JavaThread termination support
1095 enum TerminatedTypes {
1096 _not_terminated = 0xDEAD - 2,
1097 _thread_exiting, // JavaThread::exit() has been called for this thread
1098 _thread_terminated, // JavaThread is removed from thread list
1099 _vm_exited // JavaThread is still executing native code, but VM is terminated
1100 // only VM_Exit can set _vm_exited
1101 };
1102
1103 // In general a JavaThread's _terminated field transitions as follows:
1104 //
1105 // _not_terminated => _thread_exiting => _thread_terminated
1106 //
1107 // _vm_exited is a special value to cover the case of a JavaThread
1108 // executing native code after the VM itself is terminated.
1109 volatile TerminatedTypes _terminated;
1110 // suspend/resume support
1111 volatile bool _suspend_equivalent; // Suspend equivalent condition
1112 jint _in_deopt_handler; // count of deoptimization
1113 // handlers thread is in
1114 volatile bool _doing_unsafe_access; // Thread may fault due to unsafe access
1115 bool _do_not_unlock_if_synchronized; // Do not unlock the receiver of a synchronized method (since it was
1116 // never locked) when throwing an exception. Used by interpreter only.
1117
1118 // JNI attach states:
1119 enum JNIAttachStates {
1120 _not_attaching_via_jni = 1, // thread is not attaching via JNI
1121 _attaching_via_jni, // thread is attaching via JNI
1122 _attached_via_jni // thread has attached via JNI
1123 };
1124
1125 // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
1126 // A native thread that is attaching via JNI starts with a value
1127 // of _attaching_via_jni and transitions to _attached_via_jni.
1128 volatile JNIAttachStates _jni_attach_state;
1129
1130 public:
1131 // State of the stack guard pages for this thread.
1132 enum StackGuardState {
1133 stack_guard_unused, // not needed
1134 stack_guard_reserved_disabled,
1135 stack_guard_yellow_reserved_disabled,// disabled (temporarily) after stack overflow
1136 stack_guard_enabled // enabled
1137 };
1138
1139 private:
1140
1141 #if INCLUDE_JVMCI
1142 // The _pending_* fields below are used to communicate extra information
1143 // from an uncommon trap in JVMCI compiled code to the uncommon trap handler.
1144
1145 // Communicates the DeoptReason and DeoptAction of the uncommon trap
1146 int _pending_deoptimization;
1147
1148 // Specifies whether the uncommon trap is to bci 0 of a synchronized method
1149 // before the monitor has been acquired.
1150 bool _pending_monitorenter;
1151
1152 // Specifies if the DeoptReason for the last uncommon trap was Reason_transfer_to_interpreter
1153 bool _pending_transfer_to_interpreter;
1154
1155 // True if in a runtime call from compiled code that will deoptimize
1156 // and re-execute a failed heap allocation in the interpreter.
1157 bool _in_retryable_allocation;
1158
1159 // An id of a speculation that JVMCI compiled code can use to further describe and
1160 // uniquely identify the speculative optimization guarded by the uncommon trap
1161 jlong _pending_failed_speculation;
1162
1163 // These fields are mutually exclusive in terms of live ranges.
1164 union {
1165 // Communicates the pc at which the most recent implicit exception occurred
1166 // from the signal handler to a deoptimization stub.
1167 address _implicit_exception_pc;
1168
1169 // Communicates an alternative call target to an i2c stub from a JavaCall .
1170 address _alternate_call_target;
1171 } _jvmci;
1172
1173 // Support for high precision, thread sensitive counters in JVMCI compiled code.
1174 jlong* _jvmci_counters;
1175
1176 public:
1177 static jlong* _jvmci_old_thread_counters;
1178 static void collect_counters(jlong* array, int length);
1179 void resize_counters(int current_size, int new_size);
1180 static void resize_all_jvmci_counters(int new_size);
1181
1182 private:
1183 #endif // INCLUDE_JVMCI
1184
1185 StackGuardState _stack_guard_state;
1186
1187 // Precompute the limit of the stack as used in stack overflow checks.
1188 // We load it from here to simplify the stack overflow check in assembly.
1189 address _stack_overflow_limit;
1190 address _reserved_stack_activation;
1191
1192 // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
1193 // used to temp. parsing values into and out of the runtime system during exception handling for compiled
1194 // code)
1195 volatile oop _exception_oop; // Exception thrown in compiled code
1196 volatile address _exception_pc; // PC where exception happened
1197 volatile address _exception_handler_pc; // PC for handler of exception
1198 volatile int _is_method_handle_return; // true (== 1) if the current exception PC is a MethodHandle call site.
1199
1200 private:
1201 // support for JNI critical regions
1202 jint _jni_active_critical; // count of entries into JNI critical region
1203
1204 // Checked JNI: function name requires exception check
1205 char* _pending_jni_exception_check_fn;
1206
1207 // For deadlock detection.
1208 int _depth_first_number;
1209
1210 // JVMTI PopFrame support
1211 // This is set to popframe_pending to signal that top Java frame should be popped immediately
1212 int _popframe_condition;
1213
1214 // If reallocation of scalar replaced objects fails, we throw OOM
1215 // and during exception propagation, pop the top
1216 // _frames_to_pop_failed_realloc frames, the ones that reference
1217 // failed reallocations.
1218 int _frames_to_pop_failed_realloc;
1219
1220 friend class VMThread;
1221 friend class ThreadWaitTransition;
1222 friend class VM_Exit;
1223
1224 void initialize(); // Initialized the instance variables
1225
1226 public:
1227 // Constructor
1228 JavaThread(bool is_attaching_via_jni = false); // for main thread and JNI attached threads
1229 JavaThread(ThreadFunction entry_point, size_t stack_size = 0);
1230 ~JavaThread();
1231
1232 #ifdef ASSERT
1233 // verify this JavaThread hasn't be published in the Threads::list yet
1234 void verify_not_published();
1235 #endif // ASSERT
1236
1237 //JNI functiontable getter/setter for JVMTI jni function table interception API.
1238 void set_jni_functions(struct JNINativeInterface_* functionTable) {
1239 _jni_environment.functions = functionTable;
1240 }
1241 struct JNINativeInterface_* get_jni_functions() {
1242 return (struct JNINativeInterface_ *)_jni_environment.functions;
1243 }
1244
1245 // This function is called at thread creation to allow
1246 // platform specific thread variables to be initialized.
1247 void cache_global_variables();
1248
1249 // Executes Shutdown.shutdown()
1250 void invoke_shutdown_hooks();
1251
1252 // Cleanup on thread exit
1253 enum ExitType {
1254 normal_exit,
1255 jni_detach
1256 };
1257 void exit(bool destroy_vm, ExitType exit_type = normal_exit);
1258
1259 void cleanup_failed_attach_current_thread(bool is_daemon);
1260
1261 // Testers
1262 virtual bool is_Java_thread() const { return true; }
1263 virtual bool can_call_java() const { return true; }
1264
1265 virtual bool is_active_Java_thread() const {
1266 return on_thread_list() && !is_terminated();
1267 }
1268
1269 // Thread oop. threadObj() can be NULL for initial JavaThread
1270 // (or for threads attached via JNI)
1271 oop threadObj() const { return _threadObj; }
1272 void set_threadObj(oop p) { _threadObj = p; }
1273
1274 // Prepare thread and add to priority queue. If a priority is
1275 // not specified, use the priority of the thread object. Threads_lock
1276 // must be held while this function is called.
1277 void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
1278
1279 void set_saved_exception_pc(address pc) { _saved_exception_pc = pc; }
1280 address saved_exception_pc() { return _saved_exception_pc; }
1281
1282
1283 ThreadFunction entry_point() const { return _entry_point; }
1284
1285 // Allocates a new Java level thread object for this thread. thread_name may be NULL.
1286 void allocate_threadObj(Handle thread_group, const char* thread_name, bool daemon, TRAPS);
1287
1288 // Last frame anchor routines
1289
1290 JavaFrameAnchor* frame_anchor(void) { return &_anchor; }
1291
1292 // last_Java_sp
1293 bool has_last_Java_frame() const { return _anchor.has_last_Java_frame(); }
1294 intptr_t* last_Java_sp() const { return _anchor.last_Java_sp(); }
1295
1296 // last_Java_pc
1297
1298 address last_Java_pc(void) { return _anchor.last_Java_pc(); }
1299
1300 // Safepoint support
1301 inline JavaThreadState thread_state() const;
1302 inline void set_thread_state(JavaThreadState s);
1303 inline void set_thread_state_fence(JavaThreadState s); // fence after setting thread state
1304 inline ThreadSafepointState* safepoint_state() const;
1305 inline void set_safepoint_state(ThreadSafepointState* state);
1306 inline bool is_at_poll_safepoint();
1307
1308 // JavaThread termination and lifecycle support:
1309 void smr_delete();
1310 bool on_thread_list() const { return _on_thread_list; }
1311 void set_on_thread_list() { _on_thread_list = true; }
1312
1313 // thread has called JavaThread::exit() or is terminated
1314 bool is_exiting() const;
1315 // thread is terminated (no longer on the threads list); we compare
1316 // against the two non-terminated values so that a freed JavaThread
1317 // will also be considered terminated.
1318 bool check_is_terminated(TerminatedTypes l_terminated) const {
1319 return l_terminated != _not_terminated && l_terminated != _thread_exiting;
1320 }
1321 bool is_terminated() const;
1322 void set_terminated(TerminatedTypes t);
1323 // special for Threads::remove() which is static:
1324 void set_terminated_value();
1325 void block_if_vm_exited();
1326
1327 bool doing_unsafe_access() { return _doing_unsafe_access; }
1328 void set_doing_unsafe_access(bool val) { _doing_unsafe_access = val; }
1329
1330 bool do_not_unlock_if_synchronized() { return _do_not_unlock_if_synchronized; }
1331 void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
1332
1333 inline void set_polling_page_release(void* poll_value);
1334 inline void set_polling_page(void* poll_value);
1335 inline volatile void* get_polling_page();
1336
1337 private:
1338 // Support for thread handshake operations
1339 HandshakeState _handshake;
1340 public:
1341 void set_handshake_operation(HandshakeOperation* op) {
1342 _handshake.set_operation(this, op);
1343 }
1344
1345 bool has_handshake() const {
1346 return _handshake.has_operation();
1347 }
1348
1349 void handshake_process_by_self() {
1350 _handshake.process_by_self(this);
1351 }
1352
1353 bool handshake_try_process_by_vmThread() {
1354 return _handshake.try_process_by_vmThread(this);
1355 }
1356
1357 #ifdef ASSERT
1358 bool is_vmthread_processing_handshake() const {
1359 return _handshake.is_vmthread_processing_handshake();
1360 }
1361 #endif
1362
1363 // Suspend/resume support for JavaThread
1364 private:
1365 inline void set_ext_suspended();
1366 inline void clear_ext_suspended();
1367
1368 public:
1369 void java_suspend(); // higher-level suspension logic called by the public APIs
1370 void java_resume(); // higher-level resume logic called by the public APIs
1371 int java_suspend_self(); // low-level self-suspension mechanics
1372
1373 private:
1374 // mid-level wrapper around java_suspend_self to set up correct state and
1375 // check for a pending safepoint at the end
1376 void java_suspend_self_with_safepoint_check();
1377
1378 public:
1379 void check_and_wait_while_suspended() {
1380 assert(JavaThread::current() == this, "sanity check");
1381
1382 bool do_self_suspend;
1383 do {
1384 // were we externally suspended while we were waiting?
1385 do_self_suspend = handle_special_suspend_equivalent_condition();
1386 if (do_self_suspend) {
1387 // don't surprise the thread that suspended us by returning
1388 java_suspend_self();
1389 set_suspend_equivalent();
1390 }
1391 } while (do_self_suspend);
1392 }
1393 static void check_safepoint_and_suspend_for_native_trans(JavaThread *thread);
1394 // Check for async exception in addition to safepoint and suspend request.
1395 static void check_special_condition_for_native_trans(JavaThread *thread);
1396
1397 // Same as check_special_condition_for_native_trans but finishes the
1398 // transition into thread_in_Java mode so that it can potentially
1399 // block.
1400 static void check_special_condition_for_native_trans_and_transition(JavaThread *thread);
1401
1402 bool is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits);
1403 bool is_ext_suspend_completed_with_lock(uint32_t *bits) {
1404 MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1405 // Warning: is_ext_suspend_completed() may temporarily drop the
1406 // SR_lock to allow the thread to reach a stable thread state if
1407 // it is currently in a transient thread state.
1408 return is_ext_suspend_completed(false /* !called_by_wait */,
1409 SuspendRetryDelay, bits);
1410 }
1411
1412 // We cannot allow wait_for_ext_suspend_completion() to run forever or
1413 // we could hang. SuspendRetryCount and SuspendRetryDelay are normally
1414 // passed as the count and delay parameters. Experiments with specific
1415 // calls to wait_for_ext_suspend_completion() can be done by passing
1416 // other values in the code. Experiments with all calls can be done
1417 // via the appropriate -XX options.
1418 bool wait_for_ext_suspend_completion(int count, int delay, uint32_t *bits);
1419
1420 // test for suspend - most (all?) of these should go away
1421 bool is_thread_fully_suspended(bool wait_for_suspend, uint32_t *bits);
1422
1423 inline void set_external_suspend();
1424 inline void clear_external_suspend();
1425
1426 bool is_external_suspend() const {
1427 return (_suspend_flags & _external_suspend) != 0;
1428 }
1429 // Whenever a thread transitions from native to vm/java it must suspend
1430 // if external|deopt suspend is present.
1431 bool is_suspend_after_native() const {
1432 return (_suspend_flags & (_external_suspend JFR_ONLY(| _trace_flag))) != 0;
1433 }
1434
1435 // external suspend request is completed
1436 bool is_ext_suspended() const {
1437 return (_suspend_flags & _ext_suspended) != 0;
1438 }
1439
1440 bool is_external_suspend_with_lock() const {
1441 MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1442 return is_external_suspend();
1443 }
1444
1445 // Special method to handle a pending external suspend request
1446 // when a suspend equivalent condition lifts.
1447 bool handle_special_suspend_equivalent_condition() {
1448 assert(is_suspend_equivalent(),
1449 "should only be called in a suspend equivalence condition");
1450 MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1451 bool ret = is_external_suspend();
1452 if (!ret) {
1453 // not about to self-suspend so clear suspend equivalence
1454 clear_suspend_equivalent();
1455 }
1456 // implied else:
1457 // We have a pending external suspend request so we leave the
1458 // suspend_equivalent flag set until java_suspend_self() sets
1459 // the ext_suspended flag and clears the suspend_equivalent
1460 // flag. This insures that wait_for_ext_suspend_completion()
1461 // will return consistent values.
1462 return ret;
1463 }
1464
1465 // utility methods to see if we are doing some kind of suspension
1466 bool is_being_ext_suspended() const {
1467 MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1468 return is_ext_suspended() || is_external_suspend();
1469 }
1470
1471 bool is_suspend_equivalent() const { return _suspend_equivalent; }
1472
1473 void set_suspend_equivalent() { _suspend_equivalent = true; }
1474 void clear_suspend_equivalent() { _suspend_equivalent = false; }
1475
1476 // Thread.stop support
1477 void send_thread_stop(oop throwable);
1478 AsyncRequests clear_special_runtime_exit_condition() {
1479 AsyncRequests x = _special_runtime_exit_condition;
1480 _special_runtime_exit_condition = _no_async_condition;
1481 return x;
1482 }
1483
1484 // Are any async conditions present?
1485 bool has_async_condition() { return (_special_runtime_exit_condition != _no_async_condition); }
1486
1487 void check_and_handle_async_exceptions(bool check_unsafe_error = true);
1488
1489 // these next two are also used for self-suspension and async exception support
1490 void handle_special_runtime_exit_condition(bool check_asyncs = true);
1491
1492 // Return true if JavaThread has an asynchronous condition or
1493 // if external suspension is requested.
1494 bool has_special_runtime_exit_condition() {
1495 // Because we don't use is_external_suspend_with_lock
1496 // it is possible that we won't see an asynchronous external suspend
1497 // request that has just gotten started, i.e., SR_lock grabbed but
1498 // _external_suspend field change either not made yet or not visible
1499 // yet. However, this is okay because the request is asynchronous and
1500 // we will see the new flag value the next time through. It's also
1501 // possible that the external suspend request is dropped after
1502 // we have checked is_external_suspend(), we will recheck its value
1503 // under SR_lock in java_suspend_self().
1504 return (_special_runtime_exit_condition != _no_async_condition) ||
1505 is_external_suspend() || is_trace_suspend();
1506 }
1507
1508 void set_pending_unsafe_access_error() { _special_runtime_exit_condition = _async_unsafe_access_error; }
1509
1510 inline void set_pending_async_exception(oop e);
1511
1512 // Fast-locking support
1513 bool is_lock_owned(address adr) const;
1514
1515 // Accessors for vframe array top
1516 // The linked list of vframe arrays are sorted on sp. This means when we
1517 // unpack the head must contain the vframe array to unpack.
1518 void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
1519 vframeArray* vframe_array_head() const { return _vframe_array_head; }
1520
1521 // Side structure for deferring update of java frame locals until deopt occurs
1522 GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred_locals() const { return _deferred_locals_updates; }
1523 void set_deferred_locals(GrowableArray<jvmtiDeferredLocalVariableSet *>* vf) { _deferred_locals_updates = vf; }
1524
1525 // These only really exist to make debugging deopt problems simpler
1526
1527 void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
1528 vframeArray* vframe_array_last() const { return _vframe_array_last; }
1529
1530 // The special resourceMark used during deoptimization
1531
1532 void set_deopt_mark(DeoptResourceMark* value) { _deopt_mark = value; }
1533 DeoptResourceMark* deopt_mark(void) { return _deopt_mark; }
1534
1535 void set_deopt_compiled_method(CompiledMethod* nm) { _deopt_nmethod = nm; }
1536 CompiledMethod* deopt_compiled_method() { return _deopt_nmethod; }
1537
1538 Method* callee_target() const { return _callee_target; }
1539 void set_callee_target (Method* x) { _callee_target = x; }
1540
1541 // Oop results of vm runtime calls
1542 oop vm_result() const { return _vm_result; }
1543 void set_vm_result (oop x) { _vm_result = x; }
1544
1545 Metadata* vm_result_2() const { return _vm_result_2; }
1546 void set_vm_result_2 (Metadata* x) { _vm_result_2 = x; }
1547
1548 MemRegion deferred_card_mark() const { return _deferred_card_mark; }
1549 void set_deferred_card_mark(MemRegion mr) { _deferred_card_mark = mr; }
1550
1551 #if INCLUDE_JVMCI
1552 int pending_deoptimization() const { return _pending_deoptimization; }
1553 jlong pending_failed_speculation() const { return _pending_failed_speculation; }
1554 bool has_pending_monitorenter() const { return _pending_monitorenter; }
1555 void set_pending_monitorenter(bool b) { _pending_monitorenter = b; }
1556 void set_pending_deoptimization(int reason) { _pending_deoptimization = reason; }
1557 void set_pending_failed_speculation(jlong failed_speculation) { _pending_failed_speculation = failed_speculation; }
1558 void set_pending_transfer_to_interpreter(bool b) { _pending_transfer_to_interpreter = b; }
1559 void set_jvmci_alternate_call_target(address a) { assert(_jvmci._alternate_call_target == NULL, "must be"); _jvmci._alternate_call_target = a; }
1560 void set_jvmci_implicit_exception_pc(address a) { assert(_jvmci._implicit_exception_pc == NULL, "must be"); _jvmci._implicit_exception_pc = a; }
1561
1562 virtual bool in_retryable_allocation() const { return _in_retryable_allocation; }
1563 void set_in_retryable_allocation(bool b) { _in_retryable_allocation = b; }
1564 #endif // INCLUDE_JVMCI
1565
1566 // Exception handling for compiled methods
1567 oop exception_oop() const { return _exception_oop; }
1568 address exception_pc() const { return _exception_pc; }
1569 address exception_handler_pc() const { return _exception_handler_pc; }
1570 bool is_method_handle_return() const { return _is_method_handle_return == 1; }
1571
1572 void set_exception_oop(oop o) { (void)const_cast<oop&>(_exception_oop = o); }
1573 void set_exception_pc(address a) { _exception_pc = a; }
1574 void set_exception_handler_pc(address a) { _exception_handler_pc = a; }
1575 void set_is_method_handle_return(bool value) { _is_method_handle_return = value ? 1 : 0; }
1576
1577 void clear_exception_oop_and_pc() {
1578 set_exception_oop(NULL);
1579 set_exception_pc(NULL);
1580 }
1581
1582 // Stack overflow support
1583 //
1584 // (small addresses)
1585 //
1586 // -- <-- stack_end() ---
1587 // | |
1588 // | red pages |
1589 // | |
1590 // -- <-- stack_red_zone_base() |
1591 // | |
1592 // | guard
1593 // | yellow pages zone
1594 // | |
1595 // | |
1596 // -- <-- stack_yellow_zone_base() |
1597 // | |
1598 // | |
1599 // | reserved pages |
1600 // | |
1601 // -- <-- stack_reserved_zone_base() --- ---
1602 // /|\ shadow <-- stack_overflow_limit() (somewhere in here)
1603 // | zone
1604 // \|/ size
1605 // some untouched memory ---
1606 //
1607 //
1608 // --
1609 // |
1610 // | shadow zone
1611 // |
1612 // --
1613 // x frame n
1614 // --
1615 // x frame n-1
1616 // x
1617 // --
1618 // ...
1619 //
1620 // --
1621 // x frame 0
1622 // -- <-- stack_base()
1623 //
1624 // (large addresses)
1625 //
1626
1627 private:
1628 // These values are derived from flags StackRedPages, StackYellowPages,
1629 // StackReservedPages and StackShadowPages. The zone size is determined
1630 // ergonomically if page_size > 4K.
1631 static size_t _stack_red_zone_size;
1632 static size_t _stack_yellow_zone_size;
1633 static size_t _stack_reserved_zone_size;
1634 static size_t _stack_shadow_zone_size;
1635 public:
1636 inline size_t stack_available(address cur_sp);
1637
1638 static size_t stack_red_zone_size() {
1639 assert(_stack_red_zone_size > 0, "Don't call this before the field is initialized.");
1640 return _stack_red_zone_size;
1641 }
1642 static void set_stack_red_zone_size(size_t s) {
1643 assert(is_aligned(s, os::vm_page_size()),
1644 "We can not protect if the red zone size is not page aligned.");
1645 assert(_stack_red_zone_size == 0, "This should be called only once.");
1646 _stack_red_zone_size = s;
1647 }
1648 address stack_red_zone_base() {
1649 return (address)(stack_end() + stack_red_zone_size());
1650 }
1651 bool in_stack_red_zone(address a) {
1652 return a <= stack_red_zone_base() && a >= stack_end();
1653 }
1654
1655 static size_t stack_yellow_zone_size() {
1656 assert(_stack_yellow_zone_size > 0, "Don't call this before the field is initialized.");
1657 return _stack_yellow_zone_size;
1658 }
1659 static void set_stack_yellow_zone_size(size_t s) {
1660 assert(is_aligned(s, os::vm_page_size()),
1661 "We can not protect if the yellow zone size is not page aligned.");
1662 assert(_stack_yellow_zone_size == 0, "This should be called only once.");
1663 _stack_yellow_zone_size = s;
1664 }
1665
1666 static size_t stack_reserved_zone_size() {
1667 // _stack_reserved_zone_size may be 0. This indicates the feature is off.
1668 return _stack_reserved_zone_size;
1669 }
1670 static void set_stack_reserved_zone_size(size_t s) {
1671 assert(is_aligned(s, os::vm_page_size()),
1672 "We can not protect if the reserved zone size is not page aligned.");
1673 assert(_stack_reserved_zone_size == 0, "This should be called only once.");
1674 _stack_reserved_zone_size = s;
1675 }
1676 address stack_reserved_zone_base() {
1677 return (address)(stack_end() +
1678 (stack_red_zone_size() + stack_yellow_zone_size() + stack_reserved_zone_size()));
1679 }
1680 bool in_stack_reserved_zone(address a) {
1681 return (a <= stack_reserved_zone_base()) &&
1682 (a >= (address)((intptr_t)stack_reserved_zone_base() - stack_reserved_zone_size()));
1683 }
1684
1685 static size_t stack_yellow_reserved_zone_size() {
1686 return _stack_yellow_zone_size + _stack_reserved_zone_size;
1687 }
1688 bool in_stack_yellow_reserved_zone(address a) {
1689 return (a <= stack_reserved_zone_base()) && (a >= stack_red_zone_base());
1690 }
1691
1692 // Size of red + yellow + reserved zones.
1693 static size_t stack_guard_zone_size() {
1694 return stack_red_zone_size() + stack_yellow_reserved_zone_size();
1695 }
1696
1697 static size_t stack_shadow_zone_size() {
1698 assert(_stack_shadow_zone_size > 0, "Don't call this before the field is initialized.");
1699 return _stack_shadow_zone_size;
1700 }
1701 static void set_stack_shadow_zone_size(size_t s) {
1702 // The shadow area is not allocated or protected, so
1703 // it needs not be page aligned.
1704 // But the stack bang currently assumes that it is a
1705 // multiple of page size. This guarantees that the bang
1706 // loop touches all pages in the shadow zone.
1707 // This can be guaranteed differently, as well. E.g., if
1708 // the page size is a multiple of 4K, banging in 4K steps
1709 // suffices to touch all pages. (Some pages are banged
1710 // several times, though.)
1711 assert(is_aligned(s, os::vm_page_size()),
1712 "Stack bang assumes multiple of page size.");
1713 assert(_stack_shadow_zone_size == 0, "This should be called only once.");
1714 _stack_shadow_zone_size = s;
1715 }
1716
1717 void create_stack_guard_pages();
1718 void remove_stack_guard_pages();
1719
1720 void enable_stack_reserved_zone();
1721 void disable_stack_reserved_zone();
1722 void enable_stack_yellow_reserved_zone();
1723 void disable_stack_yellow_reserved_zone();
1724 void enable_stack_red_zone();
1725 void disable_stack_red_zone();
1726
1727 inline bool stack_guard_zone_unused();
1728 inline bool stack_yellow_reserved_zone_disabled();
1729 inline bool stack_reserved_zone_disabled();
1730 inline bool stack_guards_enabled();
1731
1732 address reserved_stack_activation() const { return _reserved_stack_activation; }
1733 void set_reserved_stack_activation(address addr) {
1734 assert(_reserved_stack_activation == stack_base()
1735 || _reserved_stack_activation == NULL
1736 || addr == stack_base(), "Must not be set twice");
1737 _reserved_stack_activation = addr;
1738 }
1739
1740 // Attempt to reguard the stack after a stack overflow may have occurred.
1741 // Returns true if (a) guard pages are not needed on this thread, (b) the
1742 // pages are already guarded, or (c) the pages were successfully reguarded.
1743 // Returns false if there is not enough stack space to reguard the pages, in
1744 // which case the caller should unwind a frame and try again. The argument
1745 // should be the caller's (approximate) sp.
1746 bool reguard_stack(address cur_sp);
1747 // Similar to above but see if current stackpoint is out of the guard area
1748 // and reguard if possible.
1749 bool reguard_stack(void);
1750
1751 address stack_overflow_limit() { return _stack_overflow_limit; }
1752 void set_stack_overflow_limit() {
1753 _stack_overflow_limit =
1754 stack_end() + MAX2(JavaThread::stack_guard_zone_size(), JavaThread::stack_shadow_zone_size());
1755 }
1756
1757 // Check if address is in the usable part of the stack (excludes protected
1758 // guard pages). Can be applied to any thread and is an approximation for
1759 // using is_in_stack when the query has to happen from another thread.
1760 bool is_in_usable_stack(address adr) const;
1761
1762 // Misc. accessors/mutators
1763 void set_do_not_unlock(void) { _do_not_unlock_if_synchronized = true; }
1764 void clr_do_not_unlock(void) { _do_not_unlock_if_synchronized = false; }
1765 bool do_not_unlock(void) { return _do_not_unlock_if_synchronized; }
1766
1767 // For assembly stub generation
1768 static ByteSize threadObj_offset() { return byte_offset_of(JavaThread, _threadObj); }
1769 static ByteSize jni_environment_offset() { return byte_offset_of(JavaThread, _jni_environment); }
1770 static ByteSize pending_jni_exception_check_fn_offset() {
1771 return byte_offset_of(JavaThread, _pending_jni_exception_check_fn);
1772 }
1773 static ByteSize last_Java_sp_offset() {
1774 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
1775 }
1776 static ByteSize last_Java_pc_offset() {
1777 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
1778 }
1779 static ByteSize frame_anchor_offset() {
1780 return byte_offset_of(JavaThread, _anchor);
1781 }
1782 static ByteSize callee_target_offset() { return byte_offset_of(JavaThread, _callee_target); }
1783 static ByteSize vm_result_offset() { return byte_offset_of(JavaThread, _vm_result); }
1784 static ByteSize vm_result_2_offset() { return byte_offset_of(JavaThread, _vm_result_2); }
1785 static ByteSize thread_state_offset() { return byte_offset_of(JavaThread, _thread_state); }
1786 static ByteSize saved_exception_pc_offset() { return byte_offset_of(JavaThread, _saved_exception_pc); }
1787 static ByteSize osthread_offset() { return byte_offset_of(JavaThread, _osthread); }
1788 #if INCLUDE_JVMCI
1789 static ByteSize pending_deoptimization_offset() { return byte_offset_of(JavaThread, _pending_deoptimization); }
1790 static ByteSize pending_monitorenter_offset() { return byte_offset_of(JavaThread, _pending_monitorenter); }
1791 static ByteSize pending_failed_speculation_offset() { return byte_offset_of(JavaThread, _pending_failed_speculation); }
1792 static ByteSize jvmci_alternate_call_target_offset() { return byte_offset_of(JavaThread, _jvmci._alternate_call_target); }
1793 static ByteSize jvmci_implicit_exception_pc_offset() { return byte_offset_of(JavaThread, _jvmci._implicit_exception_pc); }
1794 static ByteSize jvmci_counters_offset() { return byte_offset_of(JavaThread, _jvmci_counters); }
1795 #endif // INCLUDE_JVMCI
1796 static ByteSize exception_oop_offset() { return byte_offset_of(JavaThread, _exception_oop); }
1797 static ByteSize exception_pc_offset() { return byte_offset_of(JavaThread, _exception_pc); }
1798 static ByteSize exception_handler_pc_offset() { return byte_offset_of(JavaThread, _exception_handler_pc); }
1799 static ByteSize stack_overflow_limit_offset() { return byte_offset_of(JavaThread, _stack_overflow_limit); }
1800 static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); }
1801 static ByteSize stack_guard_state_offset() { return byte_offset_of(JavaThread, _stack_guard_state); }
1802 static ByteSize reserved_stack_activation_offset() { return byte_offset_of(JavaThread, _reserved_stack_activation); }
1803 static ByteSize suspend_flags_offset() { return byte_offset_of(JavaThread, _suspend_flags); }
1804
1805 static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
1806 static ByteSize should_post_on_exceptions_flag_offset() {
1807 return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
1808 }
1809 static ByteSize doing_unsafe_access_offset() { return byte_offset_of(JavaThread, _doing_unsafe_access); }
1810
1811 // Returns the jni environment for this thread
1812 JNIEnv* jni_environment() { return &_jni_environment; }
1813
1814 static JavaThread* thread_from_jni_environment(JNIEnv* env) {
1815 JavaThread *thread_from_jni_env = (JavaThread*)((intptr_t)env - in_bytes(jni_environment_offset()));
1816 // Only return NULL if thread is off the thread list; starting to
1817 // exit should not return NULL.
1818 if (thread_from_jni_env->is_terminated()) {
1819 thread_from_jni_env->block_if_vm_exited();
1820 return NULL;
1821 } else {
1822 return thread_from_jni_env;
1823 }
1824 }
1825
1826 // JNI critical regions. These can nest.
1827 bool in_critical() { return _jni_active_critical > 0; }
1828 bool in_last_critical() { return _jni_active_critical == 1; }
1829 inline void enter_critical();
1830 void exit_critical() {
1831 assert(Thread::current() == this, "this must be current thread");
1832 _jni_active_critical--;
1833 assert(_jni_active_critical >= 0, "JNI critical nesting problem?");
1834 }
1835
1836 // Checked JNI: is the programmer required to check for exceptions, if so specify
1837 // which function name. Returning to a Java frame should implicitly clear the
1838 // pending check, this is done for Native->Java transitions (i.e. user JNI code).
1839 // VM->Java transistions are not cleared, it is expected that JNI code enclosed
1840 // within ThreadToNativeFromVM makes proper exception checks (i.e. VM internal).
1841 bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != NULL; }
1842 void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = NULL; }
1843 const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; }
1844 void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; }
1845
1846 // For deadlock detection
1847 int depth_first_number() { return _depth_first_number; }
1848 void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
1849
1850 private:
1851 void set_monitor_chunks(MonitorChunk* monitor_chunks) { _monitor_chunks = monitor_chunks; }
1852
1853 public:
1854 MonitorChunk* monitor_chunks() const { return _monitor_chunks; }
1855 void add_monitor_chunk(MonitorChunk* chunk);
1856 void remove_monitor_chunk(MonitorChunk* chunk);
1857 bool in_deopt_handler() const { return _in_deopt_handler > 0; }
1858 void inc_in_deopt_handler() { _in_deopt_handler++; }
1859 void dec_in_deopt_handler() {
1860 assert(_in_deopt_handler > 0, "mismatched deopt nesting");
1861 if (_in_deopt_handler > 0) { // robustness
1862 _in_deopt_handler--;
1863 }
1864 }
1865
1866 private:
1867 void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
1868
1869 public:
1870
1871 // Frame iteration; calls the function f for all frames on the stack
1872 void frames_do(void f(frame*, const RegisterMap*));
1873
1874 // Memory operations
1875 void oops_do(OopClosure* f, CodeBlobClosure* cf);
1876
1877 // Sweeper operations
1878 virtual void nmethods_do(CodeBlobClosure* cf);
1879
1880 // RedefineClasses Support
1881 void metadata_do(MetadataClosure* f);
1882
1883 // Debug method asserting thread states are correct during a handshake operation.
1884 DEBUG_ONLY(void verify_states_for_handshake();)
1885
1886 // Misc. operations
1887 char* name() const { return (char*)get_thread_name(); }
1888 void print_on(outputStream* st, bool print_extended_info) const;
1889 void print_on(outputStream* st) const { print_on(st, false); }
1890 void print() const;
1891 void print_thread_state_on(outputStream*) const PRODUCT_RETURN;
1892 void print_on_error(outputStream* st, char* buf, int buflen) const;
1893 void print_name_on_error(outputStream* st, char* buf, int buflen) const;
1894 void verify();
1895 const char* get_thread_name() const;
1896 protected:
1897 // factor out low-level mechanics for use in both normal and error cases
1898 virtual const char* get_thread_name_string(char* buf = NULL, int buflen = 0) const;
1899 public:
1900 // Accessing frames
1901 frame last_frame() {
1902 _anchor.make_walkable(this);
1903 return pd_last_frame();
1904 }
1905 javaVFrame* last_java_vframe(RegisterMap* reg_map);
1906
1907 // Returns method at 'depth' java or native frames down the stack
1908 // Used for security checks
1909 Klass* security_get_caller_class(int depth);
1910
1911 // Print stack trace in external format
1912 void print_stack_on(outputStream* st);
1913 void print_stack() { print_stack_on(tty); }
1914
1915 // Print stack traces in various internal formats
1916 void trace_stack() PRODUCT_RETURN;
1917 void trace_stack_from(vframe* start_vf) PRODUCT_RETURN;
1918 void trace_frames() PRODUCT_RETURN;
1919
1920 // Print an annotated view of the stack frames
1921 void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN;
1922 void validate_frame_layout() {
1923 print_frame_layout(0, true);
1924 }
1925
1926 // Function for testing deoptimization
1927 void deoptimize();
1928 void make_zombies();
1929
1930 void deoptimize_marked_methods();
1931
1932 public:
1933 // Returns the running thread as a JavaThread
1934 static inline JavaThread* current();
1935
1936 // Returns the active Java thread. Do not use this if you know you are calling
1937 // from a JavaThread, as it's slower than JavaThread::current. If called from
1938 // the VMThread, it also returns the JavaThread that instigated the VMThread's
1939 // operation. You may not want that either.
1940 static JavaThread* active();
1941
1942 inline CompilerThread* as_CompilerThread();
1943
1944 protected:
1945 virtual void pre_run();
1946 virtual void run();
1947 void thread_main_inner();
1948 virtual void post_run();
1949
1950
1951 private:
1952 GrowableArray<oop>* _array_for_gc;
1953 public:
1954
1955 void register_array_for_gc(GrowableArray<oop>* array) { _array_for_gc = array; }
1956
1957 public:
1958 // Thread local information maintained by JVMTI.
1959 void set_jvmti_thread_state(JvmtiThreadState *value) { _jvmti_thread_state = value; }
1960 // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1961 // getter is used to get this JavaThread's JvmtiThreadState if it has
1962 // one which means NULL can be returned. JvmtiThreadState::state_for()
1963 // is used to get the specified JavaThread's JvmtiThreadState if it has
1964 // one or it allocates a new JvmtiThreadState for the JavaThread and
1965 // returns it. JvmtiThreadState::state_for() will return NULL only if
1966 // the specified JavaThread is exiting.
1967 JvmtiThreadState *jvmti_thread_state() const { return _jvmti_thread_state; }
1968 static ByteSize jvmti_thread_state_offset() { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1969
1970 // JVMTI PopFrame support
1971 // Setting and clearing popframe_condition
1972 // All of these enumerated values are bits. popframe_pending
1973 // indicates that a PopFrame() has been requested and not yet been
1974 // completed. popframe_processing indicates that that PopFrame() is in
1975 // the process of being completed. popframe_force_deopt_reexecution_bit
1976 // indicates that special handling is required when returning to a
1977 // deoptimized caller.
1978 enum PopCondition {
1979 popframe_inactive = 0x00,
1980 popframe_pending_bit = 0x01,
1981 popframe_processing_bit = 0x02,
1982 popframe_force_deopt_reexecution_bit = 0x04
1983 };
1984 PopCondition popframe_condition() { return (PopCondition) _popframe_condition; }
1985 void set_popframe_condition(PopCondition c) { _popframe_condition = c; }
1986 void set_popframe_condition_bit(PopCondition c) { _popframe_condition |= c; }
1987 void clear_popframe_condition() { _popframe_condition = popframe_inactive; }
1988 static ByteSize popframe_condition_offset() { return byte_offset_of(JavaThread, _popframe_condition); }
1989 bool has_pending_popframe() { return (popframe_condition() & popframe_pending_bit) != 0; }
1990 bool popframe_forcing_deopt_reexecution() { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
1991 void clear_popframe_forcing_deopt_reexecution() { _popframe_condition &= ~popframe_force_deopt_reexecution_bit; }
1992 #ifdef CC_INTERP
1993 bool pop_frame_pending(void) { return ((_popframe_condition & popframe_pending_bit) != 0); }
1994 void clr_pop_frame_pending(void) { _popframe_condition = popframe_inactive; }
1995 bool pop_frame_in_process(void) { return ((_popframe_condition & popframe_processing_bit) != 0); }
1996 void set_pop_frame_in_process(void) { _popframe_condition |= popframe_processing_bit; }
1997 void clr_pop_frame_in_process(void) { _popframe_condition &= ~popframe_processing_bit; }
1998 #endif
1999
2000 int frames_to_pop_failed_realloc() const { return _frames_to_pop_failed_realloc; }
2001 void set_frames_to_pop_failed_realloc(int nb) { _frames_to_pop_failed_realloc = nb; }
2002 void dec_frames_to_pop_failed_realloc() { _frames_to_pop_failed_realloc--; }
2003
2004 private:
2005 // Saved incoming arguments to popped frame.
2006 // Used only when popped interpreted frame returns to deoptimized frame.
2007 void* _popframe_preserved_args;
2008 int _popframe_preserved_args_size;
2009
2010 public:
2011 void popframe_preserve_args(ByteSize size_in_bytes, void* start);
2012 void* popframe_preserved_args();
2013 ByteSize popframe_preserved_args_size();
2014 WordSize popframe_preserved_args_size_in_words();
2015 void popframe_free_preserved_args();
2016
2017
2018 private:
2019 JvmtiThreadState *_jvmti_thread_state;
2020
2021 // Used by the interpreter in fullspeed mode for frame pop, method
2022 // entry, method exit and single stepping support. This field is
2023 // only set to non-zero by the VM_EnterInterpOnlyMode VM operation.
2024 // It can be set to zero asynchronously (i.e., without a VM operation
2025 // or a lock) so we have to be very careful.
2026 int _interp_only_mode;
2027
2028 public:
2029 // used by the interpreter for fullspeed debugging support (see above)
2030 static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
2031 bool is_interp_only_mode() { return (_interp_only_mode != 0); }
2032 int get_interp_only_mode() { return _interp_only_mode; }
2033 void increment_interp_only_mode() { ++_interp_only_mode; }
2034 void decrement_interp_only_mode() { --_interp_only_mode; }
2035
2036 // support for cached flag that indicates whether exceptions need to be posted for this thread
2037 // if this is false, we can avoid deoptimizing when events are thrown
2038 // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
2039 private:
2040 int _should_post_on_exceptions_flag;
2041
2042 public:
2043 int should_post_on_exceptions_flag() { return _should_post_on_exceptions_flag; }
2044 void set_should_post_on_exceptions_flag(int val) { _should_post_on_exceptions_flag = val; }
2045
2046 private:
2047 ThreadStatistics *_thread_stat;
2048
2049 public:
2050 ThreadStatistics* get_thread_stat() const { return _thread_stat; }
2051
2052 // Return a blocker object for which this thread is blocked parking.
2053 oop current_park_blocker();
2054
2055 private:
2056 static size_t _stack_size_at_create;
2057
2058 public:
2059 static inline size_t stack_size_at_create(void) {
2060 return _stack_size_at_create;
2061 }
2062 static inline void set_stack_size_at_create(size_t value) {
2063 _stack_size_at_create = value;
2064 }
2065
2066 // Machine dependent stuff
2067 #include OS_CPU_HEADER(thread)
2068
2069 // JSR166 per-thread parker
2070 private:
2071 Parker* _parker;
2072 public:
2073 Parker* parker() { return _parker; }
2074
2075 // Biased locking support
2076 private:
2077 GrowableArray<MonitorInfo*>* _cached_monitor_info;
2078 public:
2079 GrowableArray<MonitorInfo*>* cached_monitor_info() { return _cached_monitor_info; }
2080 void set_cached_monitor_info(GrowableArray<MonitorInfo*>* info) { _cached_monitor_info = info; }
2081
2082 // clearing/querying jni attach status
2083 bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; }
2084 bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
2085 inline void set_done_attaching_via_jni();
2086
2087 // Stack dump assistance:
2088 // Track the class we want to initialize but for which we have to wait
2089 // on its init_lock() because it is already being initialized.
2090 void set_class_to_be_initialized(InstanceKlass* k);
2091 InstanceKlass* class_to_be_initialized() const;
2092
2093 private:
2094 InstanceKlass* _class_to_be_initialized;
2095
2096 // java.lang.Thread.sleep support
2097 ParkEvent * _SleepEvent;
2098 public:
2099 bool sleep(jlong millis);
2100
2101 // java.lang.Thread interruption support
2102 void interrupt();
2103 bool is_interrupted(bool clear_interrupted);
2104
2105 };
2106
2107 // Inline implementation of JavaThread::current
2108 inline JavaThread* JavaThread::current() {
2109 Thread* thread = Thread::current();
2110 assert(thread->is_Java_thread(), "just checking");
2111 return (JavaThread*)thread;
2112 }
2113
2114 inline CompilerThread* JavaThread::as_CompilerThread() {
2115 assert(is_Compiler_thread(), "just checking");
2116 return (CompilerThread*)this;
2117 }
2118
2119 // Dedicated thread to sweep the code cache
2120 class CodeCacheSweeperThread : public JavaThread {
2121 CompiledMethod* _scanned_compiled_method; // nmethod being scanned by the sweeper
2122 public:
2123 CodeCacheSweeperThread();
2124 // Track the nmethod currently being scanned by the sweeper
2125 void set_scanned_compiled_method(CompiledMethod* cm) {
2126 assert(_scanned_compiled_method == NULL || cm == NULL, "should reset to NULL before writing a new value");
2127 _scanned_compiled_method = cm;
2128 }
2129
2130 // Hide sweeper thread from external view.
2131 bool is_hidden_from_external_view() const { return true; }
2132
2133 bool is_Code_cache_sweeper_thread() const { return true; }
2134
2135 // Prevent GC from unloading _scanned_compiled_method
2136 void oops_do(OopClosure* f, CodeBlobClosure* cf);
2137 void nmethods_do(CodeBlobClosure* cf);
2138 };
2139
2140 // A thread used for Compilation.
2141 class CompilerThread : public JavaThread {
2142 friend class VMStructs;
2143 private:
2144 CompilerCounters* _counters;
2145
2146 ciEnv* _env;
2147 CompileLog* _log;
2148 CompileTask* volatile _task; // print_threads_compiling can read this concurrently.
2149 CompileQueue* _queue;
2150 BufferBlob* _buffer_blob;
2151
2152 AbstractCompiler* _compiler;
2153 TimeStamp _idle_time;
2154
2155 public:
2156
2157 static CompilerThread* current();
2158
2159 CompilerThread(CompileQueue* queue, CompilerCounters* counters);
2160 ~CompilerThread();
2161
2162 bool is_Compiler_thread() const { return true; }
2163
2164 virtual bool can_call_java() const;
2165
2166 // Hide native compiler threads from external view.
2167 bool is_hidden_from_external_view() const { return !can_call_java(); }
2168
2169 void set_compiler(AbstractCompiler* c) { _compiler = c; }
2170 AbstractCompiler* compiler() const { return _compiler; }
2171
2172 CompileQueue* queue() const { return _queue; }
2173 CompilerCounters* counters() const { return _counters; }
2174
2175 // Get/set the thread's compilation environment.
2176 ciEnv* env() { return _env; }
2177 void set_env(ciEnv* env) { _env = env; }
2178
2179 BufferBlob* get_buffer_blob() const { return _buffer_blob; }
2180 void set_buffer_blob(BufferBlob* b) { _buffer_blob = b; }
2181
2182 // Get/set the thread's logging information
2183 CompileLog* log() { return _log; }
2184 void init_log(CompileLog* log) {
2185 // Set once, for good.
2186 assert(_log == NULL, "set only once");
2187 _log = log;
2188 }
2189
2190 void start_idle_timer() { _idle_time.update(); }
2191 jlong idle_time_millis() {
2192 return TimeHelper::counter_to_millis(_idle_time.ticks_since_update());
2193 }
2194
2195 #ifndef PRODUCT
2196 private:
2197 IdealGraphPrinter *_ideal_graph_printer;
2198 public:
2199 IdealGraphPrinter *ideal_graph_printer() { return _ideal_graph_printer; }
2200 void set_ideal_graph_printer(IdealGraphPrinter *n) { _ideal_graph_printer = n; }
2201 #endif
2202
2203 // Get/set the thread's current task
2204 CompileTask* task() { return _task; }
2205 void set_task(CompileTask* task) { _task = task; }
2206 };
2207
2208 inline CompilerThread* CompilerThread::current() {
2209 return JavaThread::current()->as_CompilerThread();
2210 }
2211
2212 // The active thread queue. It also keeps track of the current used
2213 // thread priorities.
2214 class Threads: AllStatic {
2215 friend class VMStructs;
2216 private:
2217 static int _number_of_threads;
2218 static int _number_of_non_daemon_threads;
2219 static int _return_code;
2220 static uintx _thread_claim_token;
2221 #ifdef ASSERT
2222 static bool _vm_complete;
2223 #endif
2224
2225 static void initialize_java_lang_classes(JavaThread* main_thread, TRAPS);
2226 static void initialize_jsr292_core_classes(TRAPS);
2227
2228 public:
2229 // Thread management
2230 // force_daemon is a concession to JNI, where we may need to add a
2231 // thread to the thread list before allocating its thread object
2232 static void add(JavaThread* p, bool force_daemon = false);
2233 static void remove(JavaThread* p, bool is_daemon);
2234 static void non_java_threads_do(ThreadClosure* tc);
2235 static void java_threads_do(ThreadClosure* tc);
2236 static void java_threads_and_vm_thread_do(ThreadClosure* tc);
2237 static void threads_do(ThreadClosure* tc);
2238 static void possibly_parallel_threads_do(bool is_par, ThreadClosure* tc);
2239
2240 // Initializes the vm and creates the vm thread
2241 static jint create_vm(JavaVMInitArgs* args, bool* canTryAgain);
2242 static void convert_vm_init_libraries_to_agents();
2243 static void create_vm_init_libraries();
2244 static void create_vm_init_agents();
2245 static void shutdown_vm_agents();
2246 static bool destroy_vm();
2247 // Supported VM versions via JNI
2248 // Includes JNI_VERSION_1_1
2249 static jboolean is_supported_jni_version_including_1_1(jint version);
2250 // Does not include JNI_VERSION_1_1
2251 static jboolean is_supported_jni_version(jint version);
2252
2253 // The "thread claim token" provides a way for threads to be claimed
2254 // by parallel worker tasks.
2255 //
2256 // Each thread contains a "token" field. A task will claim the
2257 // thread only if its token is different from the global token,
2258 // which is updated by calling change_thread_claim_token(). When
2259 // a thread is claimed, it's token is set to the global token value
2260 // so other threads in the same iteration pass won't claim it.
2261 //
2262 // For this to work change_thread_claim_token() needs to be called
2263 // exactly once in sequential code before starting parallel tasks
2264 // that should claim threads.
2265 //
2266 // New threads get their token set to 0 and change_thread_claim_token()
2267 // never sets the global token to 0.
2268 static uintx thread_claim_token() { return _thread_claim_token; }
2269 static void change_thread_claim_token();
2270 static void assert_all_threads_claimed() NOT_DEBUG_RETURN;
2271
2272 // Apply "f->do_oop" to all root oops in all threads.
2273 // This version may only be called by sequential code.
2274 static void oops_do(OopClosure* f, CodeBlobClosure* cf);
2275 // This version may be called by sequential or parallel code.
2276 static void possibly_parallel_oops_do(bool is_par, OopClosure* f, CodeBlobClosure* cf);
2277
2278 // Sweeper
2279 static void nmethods_do(CodeBlobClosure* cf);
2280
2281 // RedefineClasses support
2282 static void metadata_do(MetadataClosure* f);
2283 static void metadata_handles_do(void f(Metadata*));
2284
2285 #ifdef ASSERT
2286 static bool is_vm_complete() { return _vm_complete; }
2287 #endif // ASSERT
2288
2289 // Verification
2290 static void verify();
2291 static void print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks, bool print_extended_info);
2292 static void print(bool print_stacks, bool internal_format) {
2293 // this function is only used by debug.cpp
2294 print_on(tty, print_stacks, internal_format, false /* no concurrent lock printed */, false /* simple format */);
2295 }
2296 static void print_on_error(outputStream* st, Thread* current, char* buf, int buflen);
2297 static void print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
2298 int buflen, bool* found_current);
2299 static void print_threads_compiling(outputStream* st, char* buf, int buflen, bool short_form = false);
2300
2301 // Get Java threads that are waiting to enter a monitor.
2302 static GrowableArray<JavaThread*>* get_pending_threads(ThreadsList * t_list,
2303 int count, address monitor);
2304
2305 // Get owning Java thread from the monitor's owner field.
2306 static JavaThread *owning_thread_from_monitor_owner(ThreadsList * t_list,
2307 address owner);
2308
2309 // Number of threads on the active threads list
2310 static int number_of_threads() { return _number_of_threads; }
2311 // Number of non-daemon threads on the active threads list
2312 static int number_of_non_daemon_threads() { return _number_of_non_daemon_threads; }
2313
2314 // Deoptimizes all frames tied to marked nmethods
2315 static void deoptimized_wrt_marked_nmethods();
2316
2317 struct Test; // For private gtest access.
2318 };
2319
2320 class SignalHandlerMark: public StackObj {
2321 private:
2322 Thread* _thread;
2323 public:
2324 SignalHandlerMark(Thread* t) {
2325 _thread = t;
2326 if (_thread) _thread->enter_signal_handler();
2327 }
2328 ~SignalHandlerMark() {
2329 if (_thread) _thread->leave_signal_handler();
2330 _thread = NULL;
2331 }
2332 };
2333
2334
2335 #endif // SHARE_RUNTIME_THREAD_HPP