1 /*
2 * Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #ifndef SHARE_RUNTIME_THREAD_HPP
26 #define SHARE_RUNTIME_THREAD_HPP
27
28 #include "jni.h"
29 #include "code/compiledMethod.hpp"
30 #include "gc/shared/gcThreadLocalData.hpp"
31 #include "gc/shared/threadLocalAllocBuffer.hpp"
32 #include "memory/allocation.hpp"
33 #include "oops/oop.hpp"
34 #include "prims/jvmtiExport.hpp"
35 #include "runtime/frame.hpp"
36 #include "runtime/globals.hpp"
37 #include "runtime/handshake.hpp"
38 #include "runtime/javaFrameAnchor.hpp"
39 #include "runtime/jniHandles.hpp"
40 #include "runtime/mutexLocker.hpp"
41 #include "runtime/os.hpp"
42 #include "runtime/osThread.hpp"
43 #include "runtime/park.hpp"
44 #include "runtime/stubRoutines.hpp"
45 #include "runtime/threadHeapSampler.hpp"
46 #include "runtime/threadLocalStorage.hpp"
47 #include "runtime/threadStatisticalInfo.hpp"
48 #include "runtime/unhandledOops.hpp"
49 #include "utilities/align.hpp"
50 #include "utilities/exceptions.hpp"
51 #include "utilities/globalDefinitions.hpp"
52 #include "utilities/macros.hpp"
53 #ifdef ZERO
54 # include "stack_zero.hpp"
55 #endif
56 #if INCLUDE_JFR
57 #include "jfr/support/jfrThreadExtension.hpp"
58 #endif
59
60
61 class SafeThreadsListPtr;
62 class ThreadSafepointState;
63 class ThreadsList;
64 class ThreadsSMRSupport;
65
66 class JvmtiRawMonitor;
67 class JvmtiThreadState;
68 class ThreadStatistics;
69 class ConcurrentLocksDump;
70 class ParkEvent;
71 class Parker;
72 class MonitorInfo;
73
74 class ciEnv;
75 class CompileThread;
76 class CompileLog;
77 class CompileTask;
78 class CompileQueue;
79 class CompilerCounters;
80
81 class vframeArray;
82 class vframe;
83 class javaVFrame;
84
85 class DeoptResourceMark;
86 class jvmtiDeferredLocalVariableSet;
87
88 class ThreadClosure;
89 class ICRefillVerifier;
90 class IdealGraphPrinter;
91
92 class JVMCIEnv;
93 class JVMCIPrimitiveArray;
94
95 class Metadata;
96 class ResourceArea;
97
98 DEBUG_ONLY(class ResourceMark;)
99
100 class WorkerThread;
101
102 // Class hierarchy
103 // - Thread
104 // - JavaThread
105 // - various subclasses eg CompilerThread, ServiceThread
106 // - NonJavaThread
107 // - NamedThread
108 // - VMThread
109 // - ConcurrentGCThread
110 // - WorkerThread
111 // - GangWorker
112 // - WatcherThread
113 // - JfrThreadSampler
114 //
115 // All Thread subclasses must be either JavaThread or NonJavaThread.
116 // This means !t->is_Java_thread() iff t is a NonJavaThread, or t is
117 // a partially constructed/destroyed Thread.
118
119 // Thread execution sequence and actions:
120 // All threads:
121 // - thread_native_entry // per-OS native entry point
122 // - stack initialization
123 // - other OS-level initialization (signal masks etc)
124 // - handshake with creating thread (if not started suspended)
125 // - this->call_run() // common shared entry point
126 // - shared common initialization
127 // - this->pre_run() // virtual per-thread-type initialization
128 // - this->run() // virtual per-thread-type "main" logic
129 // - shared common tear-down
130 // - this->post_run() // virtual per-thread-type tear-down
131 // - // 'this' no longer referenceable
132 // - OS-level tear-down (minimal)
133 // - final logging
134 //
135 // For JavaThread:
136 // - this->run() // virtual but not normally overridden
137 // - this->thread_main_inner() // extra call level to ensure correct stack calculations
138 // - this->entry_point() // set differently for each kind of JavaThread
139
140 class Thread: public ThreadShadow {
141 friend class VMStructs;
142 friend class JVMCIVMStructs;
143 private:
144
145 #ifndef USE_LIBRARY_BASED_TLS_ONLY
146 // Current thread is maintained as a thread-local variable
147 static THREAD_LOCAL Thread* _thr_current;
148 #endif
149
150 // Thread local data area available to the GC. The internal
151 // structure and contents of this data area is GC-specific.
152 // Only GC and GC barrier code should access this data area.
153 GCThreadLocalData _gc_data;
154
155 public:
156 static ByteSize gc_data_offset() {
157 return byte_offset_of(Thread, _gc_data);
158 }
159
160 template <typename T> T* gc_data() {
161 STATIC_ASSERT(sizeof(T) <= sizeof(_gc_data));
162 return reinterpret_cast<T*>(&_gc_data);
163 }
164
165 // Exception handling
166 // (Note: _pending_exception and friends are in ThreadShadow)
167 //oop _pending_exception; // pending exception for current thread
168 // const char* _exception_file; // file information for exception (debugging only)
169 // int _exception_line; // line information for exception (debugging only)
170 protected:
171
172 DEBUG_ONLY(static Thread* _starting_thread;)
173
174 // Support for forcing alignment of thread objects for biased locking
175 void* _real_malloc_address;
176
177 // JavaThread lifecycle support:
178 friend class SafeThreadsListPtr; // for _threads_list_ptr, cmpxchg_threads_hazard_ptr(), {dec_,inc_,}nested_threads_hazard_ptr_cnt(), {g,s}et_threads_hazard_ptr(), inc_nested_handle_cnt(), tag_hazard_ptr() access
179 friend class ScanHazardPtrGatherProtectedThreadsClosure; // for cmpxchg_threads_hazard_ptr(), get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
180 friend class ScanHazardPtrGatherThreadsListClosure; // for get_threads_hazard_ptr(), untag_hazard_ptr() access
181 friend class ScanHazardPtrPrintMatchingThreadsClosure; // for get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
182 friend class ThreadsSMRSupport; // for _nested_threads_hazard_ptr_cnt, _threads_hazard_ptr, _threads_list_ptr access
183
184 ThreadsList* volatile _threads_hazard_ptr;
185 SafeThreadsListPtr* _threads_list_ptr;
186 ThreadsList* cmpxchg_threads_hazard_ptr(ThreadsList* exchange_value, ThreadsList* compare_value);
187 ThreadsList* get_threads_hazard_ptr();
188 void set_threads_hazard_ptr(ThreadsList* new_list);
189 static bool is_hazard_ptr_tagged(ThreadsList* list) {
190 return (intptr_t(list) & intptr_t(1)) == intptr_t(1);
191 }
192 static ThreadsList* tag_hazard_ptr(ThreadsList* list) {
193 return (ThreadsList*)(intptr_t(list) | intptr_t(1));
194 }
195 static ThreadsList* untag_hazard_ptr(ThreadsList* list) {
196 return (ThreadsList*)(intptr_t(list) & ~intptr_t(1));
197 }
198 // This field is enabled via -XX:+EnableThreadSMRStatistics:
199 uint _nested_threads_hazard_ptr_cnt;
200 void dec_nested_threads_hazard_ptr_cnt() {
201 assert(_nested_threads_hazard_ptr_cnt != 0, "mismatched {dec,inc}_nested_threads_hazard_ptr_cnt()");
202 _nested_threads_hazard_ptr_cnt--;
203 }
204 void inc_nested_threads_hazard_ptr_cnt() {
205 _nested_threads_hazard_ptr_cnt++;
206 }
207 uint nested_threads_hazard_ptr_cnt() {
208 return _nested_threads_hazard_ptr_cnt;
209 }
210
211 public:
212 void* operator new(size_t size) throw() { return allocate(size, true); }
213 void* operator new(size_t size, const std::nothrow_t& nothrow_constant) throw() {
214 return allocate(size, false); }
215 void operator delete(void* p);
216
217 protected:
218 static void* allocate(size_t size, bool throw_excpt, MEMFLAGS flags = mtThread);
219 private:
220
221 // ***************************************************************
222 // Suspend and resume support
223 // ***************************************************************
224 //
225 // VM suspend/resume no longer exists - it was once used for various
226 // things including safepoints but was deprecated and finally removed
227 // in Java 7. Because VM suspension was considered "internal" Java-level
228 // suspension was considered "external", and this legacy naming scheme
229 // remains.
230 //
231 // External suspend/resume requests come from JVM_SuspendThread,
232 // JVM_ResumeThread, JVMTI SuspendThread, and finally JVMTI
233 // ResumeThread. External
234 // suspend requests cause _external_suspend to be set and external
235 // resume requests cause _external_suspend to be cleared.
236 // External suspend requests do not nest on top of other external
237 // suspend requests. The higher level APIs reject suspend requests
238 // for already suspended threads.
239 //
240 // The external_suspend
241 // flag is checked by has_special_runtime_exit_condition() and java thread
242 // will self-suspend when handle_special_runtime_exit_condition() is
243 // called. Most uses of the _thread_blocked state in JavaThreads are
244 // considered the same as being externally suspended; if the blocking
245 // condition lifts, the JavaThread will self-suspend. Other places
246 // where VM checks for external_suspend include:
247 // + mutex granting (do not enter monitors when thread is suspended)
248 // + state transitions from _thread_in_native
249 //
250 // In general, java_suspend() does not wait for an external suspend
251 // request to complete. When it returns, the only guarantee is that
252 // the _external_suspend field is true.
253 //
254 // wait_for_ext_suspend_completion() is used to wait for an external
255 // suspend request to complete. External suspend requests are usually
256 // followed by some other interface call that requires the thread to
257 // be quiescent, e.g., GetCallTrace(). By moving the "wait time" into
258 // the interface that requires quiescence, we give the JavaThread a
259 // chance to self-suspend before we need it to be quiescent. This
260 // improves overall suspend/query performance.
261 //
262 // _suspend_flags controls the behavior of java_ suspend/resume.
263 // It must be set under the protection of SR_lock. Read from the flag is
264 // OK without SR_lock as long as the value is only used as a hint.
265 // (e.g., check _external_suspend first without lock and then recheck
266 // inside SR_lock and finish the suspension)
267 //
268 // _suspend_flags is also overloaded for other "special conditions" so
269 // that a single check indicates whether any special action is needed
270 // eg. for async exceptions.
271 // -------------------------------------------------------------------
272 // Notes:
273 // 1. The suspend/resume logic no longer uses ThreadState in OSThread
274 // but we still update its value to keep other part of the system (mainly
275 // JVMTI) happy. ThreadState is legacy code (see notes in
276 // osThread.hpp).
277 //
278 // 2. It would be more natural if set_external_suspend() is private and
279 // part of java_suspend(), but that probably would affect the suspend/query
280 // performance. Need more investigation on this.
281
282 // suspend/resume lock: used for self-suspend
283 Monitor* _SR_lock;
284
285 protected:
286 enum SuspendFlags {
287 // NOTE: avoid using the sign-bit as cc generates different test code
288 // when the sign-bit is used, and sometimes incorrectly - see CR 6398077
289
290 _external_suspend = 0x20000000U, // thread is asked to self suspend
291 _ext_suspended = 0x40000000U, // thread has self-suspended
292
293 _has_async_exception = 0x00000001U, // there is a pending async exception
294 _critical_native_unlock = 0x00000002U, // Must call back to unlock JNI critical lock
295
296 _trace_flag = 0x00000004U // call tracing backend
297 };
298
299 // various suspension related flags - atomically updated
300 // overloaded for async exception checking in check_special_condition_for_native_trans.
301 volatile uint32_t _suspend_flags;
302
303 private:
304 int _num_nested_signal;
305
306 DEBUG_ONLY(bool _suspendible_thread;)
307
308 public:
309 void enter_signal_handler() { _num_nested_signal++; }
310 void leave_signal_handler() { _num_nested_signal--; }
311 bool is_inside_signal_handler() const { return _num_nested_signal > 0; }
312
313 // Determines if a heap allocation failure will be retried
314 // (e.g., by deoptimizing and re-executing in the interpreter).
315 // In this case, the failed allocation must raise
316 // Universe::out_of_memory_error_retry() and omit side effects
317 // such as JVMTI events and handling -XX:+HeapDumpOnOutOfMemoryError
318 // and -XX:OnOutOfMemoryError.
319 virtual bool in_retryable_allocation() const { return false; }
320
321 #ifdef ASSERT
322 void set_suspendible_thread() {
323 _suspendible_thread = true;
324 }
325
326 void clear_suspendible_thread() {
327 _suspendible_thread = false;
328 }
329
330 bool is_suspendible_thread() { return _suspendible_thread; }
331 #endif
332
333 private:
334 // Active_handles points to a block of handles
335 JNIHandleBlock* _active_handles;
336
337 // One-element thread local free list
338 JNIHandleBlock* _free_handle_block;
339
340 // Point to the last handle mark
341 HandleMark* _last_handle_mark;
342
343 // Claim value for parallel iteration over threads.
344 uintx _threads_do_token;
345
346 // Support for GlobalCounter
347 private:
348 volatile uintx _rcu_counter;
349 public:
350 volatile uintx* get_rcu_counter() {
351 return &_rcu_counter;
352 }
353
354 public:
355 void set_last_handle_mark(HandleMark* mark) { _last_handle_mark = mark; }
356 HandleMark* last_handle_mark() const { return _last_handle_mark; }
357 private:
358
359 #ifdef ASSERT
360 ICRefillVerifier* _missed_ic_stub_refill_verifier;
361
362 public:
363 ICRefillVerifier* missed_ic_stub_refill_verifier() {
364 return _missed_ic_stub_refill_verifier;
365 }
366
367 void set_missed_ic_stub_refill_verifier(ICRefillVerifier* verifier) {
368 _missed_ic_stub_refill_verifier = verifier;
369 }
370 #endif // ASSERT
371
372 private:
373
374 // Debug support for checking if code allows safepoints or not.
375 // Safepoints in the VM can happen because of allocation, invoking a VM operation, or blocking on
376 // mutex, or blocking on an object synchronizer (Java locking).
377 // If _no_safepoint_count is non-zero, then an assertion failure will happen in any of
378 // the above cases.
379 //
380 // The class NoSafepointVerifier is used to set this counter.
381 //
382 NOT_PRODUCT(int _no_safepoint_count;) // If 0, thread allow a safepoint to happen
383
384 private:
385 // Used by SkipGCALot class.
386 NOT_PRODUCT(bool _skip_gcalot;) // Should we elide gc-a-lot?
387
388 friend class GCLocker;
389 friend class NoSafepointVerifier;
390 friend class PauseNoSafepointVerifier;
391
392 volatile void* _polling_page; // Thread local polling page
393
394 ThreadLocalAllocBuffer _tlab; // Thread-local eden
395 jlong _allocated_bytes; // Cumulative number of bytes allocated on
396 // the Java heap
397 ThreadHeapSampler _heap_sampler; // For use when sampling the memory.
398
399 ThreadStatisticalInfo _statistical_info; // Statistics about the thread
400
401 JFR_ONLY(DEFINE_THREAD_LOCAL_FIELD_JFR;) // Thread-local data for jfr
402
403 int _vm_operation_started_count; // VM_Operation support
404 int _vm_operation_completed_count; // VM_Operation support
405
406 ObjectMonitor* _current_pending_monitor; // ObjectMonitor this thread
407 // is waiting to lock
408 bool _current_pending_monitor_is_from_java; // locking is from Java code
409 JvmtiRawMonitor* _current_pending_raw_monitor; // JvmtiRawMonitor this thread
410 // is waiting to lock
411
412
413 // ObjectMonitor on which this thread called Object.wait()
414 ObjectMonitor* _current_waiting_monitor;
415
416 // Per-thread ObjectMonitor lists:
417 public:
418 ObjectMonitor* om_free_list; // SLL of free ObjectMonitors
419 int om_free_count; // # on om_free_list
420 int om_free_provision; // # to try to allocate next
421 ObjectMonitor* om_in_use_list; // SLL of in-use ObjectMonitors
422 int om_in_use_count; // # on om_in_use_list
423
424 #ifdef ASSERT
425 private:
426 volatile uint64_t _visited_for_critical_count;
427
428 public:
429 void set_visited_for_critical_count(uint64_t safepoint_id) {
430 assert(_visited_for_critical_count == 0, "Must be reset before set");
431 assert((safepoint_id & 0x1) == 1, "Must be odd");
432 _visited_for_critical_count = safepoint_id;
433 }
434 void reset_visited_for_critical_count(uint64_t safepoint_id) {
435 assert(_visited_for_critical_count == safepoint_id, "Was not visited");
436 _visited_for_critical_count = 0;
437 }
438 bool was_visited_for_critical_count(uint64_t safepoint_id) const {
439 return _visited_for_critical_count == safepoint_id;
440 }
441 #endif
442
443 public:
444 enum {
445 is_definitely_current_thread = true
446 };
447
448 // Constructor
449 Thread();
450 virtual ~Thread() = 0; // Thread is abstract.
451
452 // Manage Thread::current()
453 void initialize_thread_current();
454 static void clear_thread_current(); // TLS cleanup needed before threads terminate
455
456 protected:
457 // To be implemented by children.
458 virtual void run() = 0;
459 virtual void pre_run() = 0;
460 virtual void post_run() = 0; // Note: Thread must not be deleted prior to calling this!
461
462 #ifdef ASSERT
463 enum RunState {
464 PRE_CALL_RUN,
465 CALL_RUN,
466 PRE_RUN,
467 RUN,
468 POST_RUN
469 // POST_CALL_RUN - can't define this one as 'this' may be deleted when we want to set it
470 };
471 RunState _run_state; // for lifecycle checks
472 #endif
473
474
475 public:
476 // invokes <ChildThreadClass>::run(), with common preparations and cleanups.
477 void call_run();
478
479 // Testers
480 virtual bool is_VM_thread() const { return false; }
481 virtual bool is_Java_thread() const { return false; }
482 virtual bool is_Compiler_thread() const { return false; }
483 virtual bool is_Code_cache_sweeper_thread() const { return false; }
484 virtual bool is_service_thread() const { return false; }
485 virtual bool is_hidden_from_external_view() const { return false; }
486 virtual bool is_jvmti_agent_thread() const { return false; }
487 // True iff the thread can perform GC operations at a safepoint.
488 // Generally will be true only of VM thread and parallel GC WorkGang
489 // threads.
490 virtual bool is_GC_task_thread() const { return false; }
491 virtual bool is_Watcher_thread() const { return false; }
492 virtual bool is_ConcurrentGC_thread() const { return false; }
493 virtual bool is_Named_thread() const { return false; }
494 virtual bool is_Worker_thread() const { return false; }
495
496 // Can this thread make Java upcalls
497 virtual bool can_call_java() const { return false; }
498
499 // Is this a JavaThread that is on the VM's current ThreadsList?
500 // If so it must participate in the safepoint protocol.
501 virtual bool is_active_Java_thread() const { return false; }
502
503 // Casts
504 virtual WorkerThread* as_Worker_thread() const { return NULL; }
505
506 virtual char* name() const { return (char*)"Unknown thread"; }
507
508 // Returns the current thread (ASSERTS if NULL)
509 static inline Thread* current();
510 // Returns the current thread, or NULL if not attached
511 static inline Thread* current_or_null();
512 // Returns the current thread, or NULL if not attached, and is
513 // safe for use from signal-handlers
514 static inline Thread* current_or_null_safe();
515
516 // Common thread operations
517 #ifdef ASSERT
518 static void check_for_dangling_thread_pointer(Thread *thread);
519 #endif
520 static void set_priority(Thread* thread, ThreadPriority priority);
521 static ThreadPriority get_priority(const Thread* const thread);
522 static void start(Thread* thread);
523
524 void set_native_thread_name(const char *name) {
525 assert(Thread::current() == this, "set_native_thread_name can only be called on the current thread");
526 os::set_native_thread_name(name);
527 }
528
529 Monitor* SR_lock() const { return _SR_lock; }
530
531 bool has_async_exception() const { return (_suspend_flags & _has_async_exception) != 0; }
532
533 inline void set_suspend_flag(SuspendFlags f);
534 inline void clear_suspend_flag(SuspendFlags f);
535
536 inline void set_has_async_exception();
537 inline void clear_has_async_exception();
538
539 bool do_critical_native_unlock() const { return (_suspend_flags & _critical_native_unlock) != 0; }
540
541 inline void set_critical_native_unlock();
542 inline void clear_critical_native_unlock();
543
544 inline void set_trace_flag();
545 inline void clear_trace_flag();
546
547 // Support for Unhandled Oop detection
548 // Add the field for both, fastdebug and debug, builds to keep
549 // Thread's fields layout the same.
550 // Note: CHECK_UNHANDLED_OOPS is defined only for fastdebug build.
551 #ifdef CHECK_UNHANDLED_OOPS
552 private:
553 UnhandledOops* _unhandled_oops;
554 #elif defined(ASSERT)
555 private:
556 void* _unhandled_oops;
557 #endif
558 #ifdef CHECK_UNHANDLED_OOPS
559 public:
560 UnhandledOops* unhandled_oops() { return _unhandled_oops; }
561 // Mark oop safe for gc. It may be stack allocated but won't move.
562 void allow_unhandled_oop(oop *op) {
563 if (CheckUnhandledOops) unhandled_oops()->allow_unhandled_oop(op);
564 }
565 // Clear oops at safepoint so crashes point to unhandled oop violator
566 void clear_unhandled_oops() {
567 if (CheckUnhandledOops) unhandled_oops()->clear_unhandled_oops();
568 }
569 #endif // CHECK_UNHANDLED_OOPS
570
571 public:
572 #ifndef PRODUCT
573 bool skip_gcalot() { return _skip_gcalot; }
574 void set_skip_gcalot(bool v) { _skip_gcalot = v; }
575 #endif
576
577 // Installs a pending exception to be inserted later
578 static void send_async_exception(oop thread_oop, oop java_throwable);
579
580 // Resource area
581 ResourceArea* resource_area() const { return _resource_area; }
582 void set_resource_area(ResourceArea* area) { _resource_area = area; }
583
584 OSThread* osthread() const { return _osthread; }
585 void set_osthread(OSThread* thread) { _osthread = thread; }
586
587 // JNI handle support
588 JNIHandleBlock* active_handles() const { return _active_handles; }
589 void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
590 JNIHandleBlock* free_handle_block() const { return _free_handle_block; }
591 void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
592
593 // Internal handle support
594 HandleArea* handle_area() const { return _handle_area; }
595 void set_handle_area(HandleArea* area) { _handle_area = area; }
596
597 GrowableArray<Metadata*>* metadata_handles() const { return _metadata_handles; }
598 void set_metadata_handles(GrowableArray<Metadata*>* handles){ _metadata_handles = handles; }
599
600 // Thread-Local Allocation Buffer (TLAB) support
601 ThreadLocalAllocBuffer& tlab() { return _tlab; }
602 void initialize_tlab() {
603 if (UseTLAB) {
604 tlab().initialize();
605 }
606 }
607
608 jlong allocated_bytes() { return _allocated_bytes; }
609 void set_allocated_bytes(jlong value) { _allocated_bytes = value; }
610 void incr_allocated_bytes(jlong size) { _allocated_bytes += size; }
611 inline jlong cooked_allocated_bytes();
612
613 ThreadHeapSampler& heap_sampler() { return _heap_sampler; }
614
615 ThreadStatisticalInfo& statistical_info() { return _statistical_info; }
616
617 JFR_ONLY(DEFINE_THREAD_LOCAL_ACCESSOR_JFR;)
618
619 bool is_trace_suspend() { return (_suspend_flags & _trace_flag) != 0; }
620
621 // VM operation support
622 int vm_operation_ticket() { return ++_vm_operation_started_count; }
623 int vm_operation_completed_count() { return _vm_operation_completed_count; }
624 void increment_vm_operation_completed_count() { _vm_operation_completed_count++; }
625
626 // For tracking the heavyweight monitor the thread is pending on.
627 ObjectMonitor* current_pending_monitor() {
628 return _current_pending_monitor;
629 }
630 void set_current_pending_monitor(ObjectMonitor* monitor) {
631 _current_pending_monitor = monitor;
632 }
633 void set_current_pending_monitor_is_from_java(bool from_java) {
634 _current_pending_monitor_is_from_java = from_java;
635 }
636 bool current_pending_monitor_is_from_java() {
637 return _current_pending_monitor_is_from_java;
638 }
639
640 // For tracking the ObjectMonitor on which this thread called Object.wait()
641 ObjectMonitor* current_waiting_monitor() {
642 return _current_waiting_monitor;
643 }
644 void set_current_waiting_monitor(ObjectMonitor* monitor) {
645 _current_waiting_monitor = monitor;
646 }
647
648 // For tracking the Jvmti raw monitor the thread is pending on.
649 JvmtiRawMonitor* current_pending_raw_monitor() {
650 return _current_pending_raw_monitor;
651 }
652 void set_current_pending_raw_monitor(JvmtiRawMonitor* monitor) {
653 _current_pending_raw_monitor = monitor;
654 }
655
656 // GC support
657 // Apply "f->do_oop" to all root oops in "this".
658 // Used by JavaThread::oops_do.
659 // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames
660 virtual void oops_do(OopClosure* f, CodeBlobClosure* cf);
661
662 // Handles the parallel case for claim_threads_do.
663 private:
664 bool claim_par_threads_do(uintx claim_token);
665 public:
666 // Requires that "claim_token" is that of the current iteration.
667 // If "is_par" is false, sets the token of "this" to
668 // "claim_token", and returns "true". If "is_par" is true,
669 // uses an atomic instruction to set the current thread's token to
670 // "claim_token", if it is not already. Returns "true" iff the
671 // calling thread does the update, this indicates that the calling thread
672 // has claimed the thread in the current iteration.
673 bool claim_threads_do(bool is_par, uintx claim_token) {
674 if (!is_par) {
675 _threads_do_token = claim_token;
676 return true;
677 } else {
678 return claim_par_threads_do(claim_token);
679 }
680 }
681
682 uintx threads_do_token() const { return _threads_do_token; }
683
684 // jvmtiRedefineClasses support
685 void metadata_handles_do(void f(Metadata*));
686
687 // Used by fast lock support
688 virtual bool is_lock_owned(address adr) const;
689
690 // Check if address is in the stack of the thread (not just for locks).
691 // Warning: the method can only be used on the running thread
692 bool is_in_stack(address adr) const;
693 // Check if address is in the usable part of the stack (excludes protected
694 // guard pages)
695 bool is_in_usable_stack(address adr) const;
696
697 // Sets this thread as starting thread. Returns failure if thread
698 // creation fails due to lack of memory, too many threads etc.
699 bool set_as_starting_thread();
700
701 protected:
702 // OS data associated with the thread
703 OSThread* _osthread; // Platform-specific thread information
704
705 // Thread local resource area for temporary allocation within the VM
706 ResourceArea* _resource_area;
707
708 DEBUG_ONLY(ResourceMark* _current_resource_mark;)
709
710 // Thread local handle area for allocation of handles within the VM
711 HandleArea* _handle_area;
712 GrowableArray<Metadata*>* _metadata_handles;
713
714 // Support for stack overflow handling, get_thread, etc.
715 address _stack_base;
716 size_t _stack_size;
717 int _lgrp_id;
718
719 volatile void** polling_page_addr() { return &_polling_page; }
720
721 public:
722 // Stack overflow support
723 address stack_base() const { assert(_stack_base != NULL,"Sanity check"); return _stack_base; }
724 void set_stack_base(address base) { _stack_base = base; }
725 size_t stack_size() const { return _stack_size; }
726 void set_stack_size(size_t size) { _stack_size = size; }
727 address stack_end() const { return stack_base() - stack_size(); }
728 void record_stack_base_and_size();
729 void register_thread_stack_with_NMT() NOT_NMT_RETURN;
730
731 bool on_local_stack(address adr) const {
732 // QQQ this has knowledge of direction, ought to be a stack method
733 return (_stack_base > adr && adr >= stack_end());
734 }
735
736 int lgrp_id() const { return _lgrp_id; }
737 void set_lgrp_id(int value) { _lgrp_id = value; }
738
739 // Printing
740 void print_on(outputStream* st, bool print_extended_info) const;
741 virtual void print_on(outputStream* st) const { print_on(st, false); }
742 void print() const;
743 virtual void print_on_error(outputStream* st, char* buf, int buflen) const;
744 void print_value_on(outputStream* st) const;
745
746 // Debug-only code
747 #ifdef ASSERT
748 private:
749 // Deadlock detection support for Mutex locks. List of locks own by thread.
750 Mutex* _owned_locks;
751 // Mutex::set_owner_implementation is the only place where _owned_locks is modified,
752 // thus the friendship
753 friend class Mutex;
754 friend class Monitor;
755
756 public:
757 void print_owned_locks_on(outputStream* st) const;
758 void print_owned_locks() const { print_owned_locks_on(tty); }
759 Mutex* owned_locks() const { return _owned_locks; }
760 bool owns_locks() const { return owned_locks() != NULL; }
761
762 // Deadlock detection
763 ResourceMark* current_resource_mark() { return _current_resource_mark; }
764 void set_current_resource_mark(ResourceMark* rm) { _current_resource_mark = rm; }
765 #endif // ASSERT
766
767 // These functions check conditions on a JavaThread before possibly going to a safepoint,
768 // including NoSafepointVerifier.
769 void check_for_valid_safepoint_state() NOT_DEBUG_RETURN;
770 void check_possible_safepoint() NOT_DEBUG_RETURN;
771
772 private:
773 volatile int _jvmti_env_iteration_count;
774
775 public:
776 void entering_jvmti_env_iteration() { ++_jvmti_env_iteration_count; }
777 void leaving_jvmti_env_iteration() { --_jvmti_env_iteration_count; }
778 bool is_inside_jvmti_env_iteration() { return _jvmti_env_iteration_count > 0; }
779
780 // Code generation
781 static ByteSize exception_file_offset() { return byte_offset_of(Thread, _exception_file); }
782 static ByteSize exception_line_offset() { return byte_offset_of(Thread, _exception_line); }
783 static ByteSize active_handles_offset() { return byte_offset_of(Thread, _active_handles); }
784
785 static ByteSize stack_base_offset() { return byte_offset_of(Thread, _stack_base); }
786 static ByteSize stack_size_offset() { return byte_offset_of(Thread, _stack_size); }
787
788 static ByteSize polling_page_offset() { return byte_offset_of(Thread, _polling_page); }
789
790 static ByteSize tlab_start_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::start_offset(); }
791 static ByteSize tlab_end_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::end_offset(); }
792 static ByteSize tlab_top_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::top_offset(); }
793 static ByteSize tlab_pf_top_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::pf_top_offset(); }
794
795 static ByteSize allocated_bytes_offset() { return byte_offset_of(Thread, _allocated_bytes); }
796
797 JFR_ONLY(DEFINE_THREAD_LOCAL_OFFSET_JFR;)
798
799 public:
800 volatile intptr_t _Stalled;
801 volatile int _TypeTag;
802 ParkEvent * _ParkEvent; // for Object monitors and JVMTI raw monitors
803 ParkEvent * _MuxEvent; // for low-level muxAcquire-muxRelease
804 int NativeSyncRecursion; // diagnostic
805
806 volatile int _OnTrap; // Resume-at IP delta
807 jint _hashStateW; // Marsaglia Shift-XOR thread-local RNG
808 jint _hashStateX; // thread-specific hashCode generator state
809 jint _hashStateY;
810 jint _hashStateZ;
811
812 // Low-level leaf-lock primitives used to implement synchronization
813 // and native monitor-mutex infrastructure.
814 // Not for general synchronization use.
815 static void SpinAcquire(volatile int * Lock, const char * Name);
816 static void SpinRelease(volatile int * Lock);
817 static void muxAcquire(volatile intptr_t * Lock, const char * Name);
818 static void muxRelease(volatile intptr_t * Lock);
819 };
820
821 // Inline implementation of Thread::current()
822 inline Thread* Thread::current() {
823 Thread* current = current_or_null();
824 assert(current != NULL, "Thread::current() called on detached thread");
825 return current;
826 }
827
828 inline Thread* Thread::current_or_null() {
829 #ifndef USE_LIBRARY_BASED_TLS_ONLY
830 return _thr_current;
831 #else
832 if (ThreadLocalStorage::is_initialized()) {
833 return ThreadLocalStorage::thread();
834 }
835 return NULL;
836 #endif
837 }
838
839 inline Thread* Thread::current_or_null_safe() {
840 if (ThreadLocalStorage::is_initialized()) {
841 return ThreadLocalStorage::thread();
842 }
843 return NULL;
844 }
845
846 class NonJavaThread: public Thread {
847 friend class VMStructs;
848
849 NonJavaThread* volatile _next;
850
851 class List;
852 static List _the_list;
853
854 void add_to_the_list();
855 void remove_from_the_list();
856
857 protected:
858 virtual void pre_run();
859 virtual void post_run();
860
861 public:
862 NonJavaThread();
863 ~NonJavaThread();
864
865 class Iterator;
866 };
867
868 // Provides iteration over the list of NonJavaThreads.
869 // List addition occurs in pre_run(), and removal occurs in post_run(),
870 // so that only live fully-initialized threads can be found in the list.
871 // Threads created after an iterator is constructed will not be visited
872 // by the iterator. The scope of an iterator is a critical section; there
873 // must be no safepoint checks in that scope.
874 class NonJavaThread::Iterator : public StackObj {
875 uint _protect_enter;
876 NonJavaThread* _current;
877
878 NONCOPYABLE(Iterator);
879
880 public:
881 Iterator();
882 ~Iterator();
883
884 bool end() const { return _current == NULL; }
885 NonJavaThread* current() const { return _current; }
886 void step();
887 };
888
889 // Name support for threads. non-JavaThread subclasses with multiple
890 // uniquely named instances should derive from this.
891 class NamedThread: public NonJavaThread {
892 friend class VMStructs;
893 enum {
894 max_name_len = 64
895 };
896 private:
897 char* _name;
898 // log JavaThread being processed by oops_do
899 JavaThread* _processed_thread;
900 uint _gc_id; // The current GC id when a thread takes part in GC
901
902 public:
903 NamedThread();
904 ~NamedThread();
905 // May only be called once per thread.
906 void set_name(const char* format, ...) ATTRIBUTE_PRINTF(2, 3);
907 virtual bool is_Named_thread() const { return true; }
908 virtual char* name() const { return _name == NULL ? (char*)"Unknown Thread" : _name; }
909 JavaThread *processed_thread() { return _processed_thread; }
910 void set_processed_thread(JavaThread *thread) { _processed_thread = thread; }
911 virtual void print_on(outputStream* st) const;
912
913 void set_gc_id(uint gc_id) { _gc_id = gc_id; }
914 uint gc_id() { return _gc_id; }
915 };
916
917 // Worker threads are named and have an id of an assigned work.
918 class WorkerThread: public NamedThread {
919 private:
920 uint _id;
921 public:
922 WorkerThread() : _id(0) { }
923 virtual bool is_Worker_thread() const { return true; }
924
925 virtual WorkerThread* as_Worker_thread() const {
926 assert(is_Worker_thread(), "Dubious cast to WorkerThread*?");
927 return (WorkerThread*) this;
928 }
929
930 void set_id(uint work_id) { _id = work_id; }
931 uint id() const { return _id; }
932 };
933
934 // A single WatcherThread is used for simulating timer interrupts.
935 class WatcherThread: public NonJavaThread {
936 friend class VMStructs;
937 protected:
938 virtual void run();
939
940 private:
941 static WatcherThread* _watcher_thread;
942
943 static bool _startable;
944 // volatile due to at least one lock-free read
945 volatile static bool _should_terminate;
946 public:
947 enum SomeConstants {
948 delay_interval = 10 // interrupt delay in milliseconds
949 };
950
951 // Constructor
952 WatcherThread();
953
954 // No destruction allowed
955 ~WatcherThread() {
956 guarantee(false, "WatcherThread deletion must fix the race with VM termination");
957 }
958
959 // Tester
960 bool is_Watcher_thread() const { return true; }
961
962 // Printing
963 char* name() const { return (char*)"VM Periodic Task Thread"; }
964 void print_on(outputStream* st) const;
965 void unpark();
966
967 // Returns the single instance of WatcherThread
968 static WatcherThread* watcher_thread() { return _watcher_thread; }
969
970 // Create and start the single instance of WatcherThread, or stop it on shutdown
971 static void start();
972 static void stop();
973 // Only allow start once the VM is sufficiently initialized
974 // Otherwise the first task to enroll will trigger the start
975 static void make_startable();
976 private:
977 int sleep() const;
978 };
979
980
981 class CompilerThread;
982
983 typedef void (*ThreadFunction)(JavaThread*, TRAPS);
984
985 class JavaThread: public Thread {
986 friend class VMStructs;
987 friend class JVMCIVMStructs;
988 friend class WhiteBox;
989 private:
990 bool _on_thread_list; // Is set when this JavaThread is added to the Threads list
991 oop _threadObj; // The Java level thread object
992
993 #ifdef ASSERT
994 private:
995 int _java_call_counter;
996
997 public:
998 int java_call_counter() { return _java_call_counter; }
999 void inc_java_call_counter() { _java_call_counter++; }
1000 void dec_java_call_counter() {
1001 assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
1002 _java_call_counter--;
1003 }
1004 private: // restore original namespace restriction
1005 #endif // ifdef ASSERT
1006
1007 #ifndef PRODUCT
1008 public:
1009 enum {
1010 jump_ring_buffer_size = 16
1011 };
1012 private: // restore original namespace restriction
1013 #endif
1014
1015 JavaFrameAnchor _anchor; // Encapsulation of current java frame and it state
1016
1017 ThreadFunction _entry_point;
1018
1019 JNIEnv _jni_environment;
1020
1021 // Deopt support
1022 DeoptResourceMark* _deopt_mark; // Holds special ResourceMark for deoptimization
1023
1024 CompiledMethod* _deopt_nmethod; // CompiledMethod that is currently being deoptimized
1025 vframeArray* _vframe_array_head; // Holds the heap of the active vframeArrays
1026 vframeArray* _vframe_array_last; // Holds last vFrameArray we popped
1027 // Because deoptimization is lazy we must save jvmti requests to set locals
1028 // in compiled frames until we deoptimize and we have an interpreter frame.
1029 // This holds the pointer to array (yeah like there might be more than one) of
1030 // description of compiled vframes that have locals that need to be updated.
1031 GrowableArray<jvmtiDeferredLocalVariableSet*>* _deferred_locals_updates;
1032
1033 // Handshake value for fixing 6243940. We need a place for the i2c
1034 // adapter to store the callee Method*. This value is NEVER live
1035 // across a gc point so it does NOT have to be gc'd
1036 // The handshake is open ended since we can't be certain that it will
1037 // be NULLed. This is because we rarely ever see the race and end up
1038 // in handle_wrong_method which is the backend of the handshake. See
1039 // code in i2c adapters and handle_wrong_method.
1040
1041 Method* _callee_target;
1042
1043 // Used to pass back results to the interpreter or generated code running Java code.
1044 oop _vm_result; // oop result is GC-preserved
1045 Metadata* _vm_result_2; // non-oop result
1046
1047 // See ReduceInitialCardMarks: this holds the precise space interval of
1048 // the most recent slow path allocation for which compiled code has
1049 // elided card-marks for performance along the fast-path.
1050 MemRegion _deferred_card_mark;
1051
1052 MonitorChunk* _monitor_chunks; // Contains the off stack monitors
1053 // allocated during deoptimization
1054 // and by JNI_MonitorEnter/Exit
1055
1056 // Async. requests support
1057 enum AsyncRequests {
1058 _no_async_condition = 0,
1059 _async_exception,
1060 _async_unsafe_access_error
1061 };
1062 AsyncRequests _special_runtime_exit_condition; // Enum indicating pending async. request
1063 oop _pending_async_exception;
1064
1065 // Safepoint support
1066 public: // Expose _thread_state for SafeFetchInt()
1067 volatile JavaThreadState _thread_state;
1068 private:
1069 ThreadSafepointState* _safepoint_state; // Holds information about a thread during a safepoint
1070 address _saved_exception_pc; // Saved pc of instruction where last implicit exception happened
1071
1072 // JavaThread termination support
1073 enum TerminatedTypes {
1074 _not_terminated = 0xDEAD - 2,
1075 _thread_exiting, // JavaThread::exit() has been called for this thread
1076 _thread_terminated, // JavaThread is removed from thread list
1077 _vm_exited // JavaThread is still executing native code, but VM is terminated
1078 // only VM_Exit can set _vm_exited
1079 };
1080
1081 // In general a JavaThread's _terminated field transitions as follows:
1082 //
1083 // _not_terminated => _thread_exiting => _thread_terminated
1084 //
1085 // _vm_exited is a special value to cover the case of a JavaThread
1086 // executing native code after the VM itself is terminated.
1087 volatile TerminatedTypes _terminated;
1088 // suspend/resume support
1089 volatile bool _suspend_equivalent; // Suspend equivalent condition
1090 jint _in_deopt_handler; // count of deoptimization
1091 // handlers thread is in
1092 volatile bool _doing_unsafe_access; // Thread may fault due to unsafe access
1093 bool _do_not_unlock_if_synchronized; // Do not unlock the receiver of a synchronized method (since it was
1094 // never locked) when throwing an exception. Used by interpreter only.
1095
1096 // JNI attach states:
1097 enum JNIAttachStates {
1098 _not_attaching_via_jni = 1, // thread is not attaching via JNI
1099 _attaching_via_jni, // thread is attaching via JNI
1100 _attached_via_jni // thread has attached via JNI
1101 };
1102
1103 // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
1104 // A native thread that is attaching via JNI starts with a value
1105 // of _attaching_via_jni and transitions to _attached_via_jni.
1106 volatile JNIAttachStates _jni_attach_state;
1107
1108 public:
1109 // State of the stack guard pages for this thread.
1110 enum StackGuardState {
1111 stack_guard_unused, // not needed
1112 stack_guard_reserved_disabled,
1113 stack_guard_yellow_reserved_disabled,// disabled (temporarily) after stack overflow
1114 stack_guard_enabled // enabled
1115 };
1116
1117 private:
1118
1119 #if INCLUDE_JVMCI
1120 // The _pending_* fields below are used to communicate extra information
1121 // from an uncommon trap in JVMCI compiled code to the uncommon trap handler.
1122
1123 // Communicates the DeoptReason and DeoptAction of the uncommon trap
1124 int _pending_deoptimization;
1125
1126 // Specifies whether the uncommon trap is to bci 0 of a synchronized method
1127 // before the monitor has been acquired.
1128 bool _pending_monitorenter;
1129
1130 // Specifies if the DeoptReason for the last uncommon trap was Reason_transfer_to_interpreter
1131 bool _pending_transfer_to_interpreter;
1132
1133 // True if in a runtime call from compiled code that will deoptimize
1134 // and re-execute a failed heap allocation in the interpreter.
1135 bool _in_retryable_allocation;
1136
1137 // An id of a speculation that JVMCI compiled code can use to further describe and
1138 // uniquely identify the speculative optimization guarded by the uncommon trap
1139 jlong _pending_failed_speculation;
1140
1141 // These fields are mutually exclusive in terms of live ranges.
1142 union {
1143 // Communicates the pc at which the most recent implicit exception occurred
1144 // from the signal handler to a deoptimization stub.
1145 address _implicit_exception_pc;
1146
1147 // Communicates an alternative call target to an i2c stub from a JavaCall .
1148 address _alternate_call_target;
1149 } _jvmci;
1150
1151 // Support for high precision, thread sensitive counters in JVMCI compiled code.
1152 jlong* _jvmci_counters;
1153
1154 public:
1155 static jlong* _jvmci_old_thread_counters;
1156 static void collect_counters(jlong* array, int length);
1157 void resize_counters(int current_size, int new_size);
1158 static void resize_all_jvmci_counters(int new_size);
1159
1160 private:
1161 #endif // INCLUDE_JVMCI
1162
1163 StackGuardState _stack_guard_state;
1164
1165 // Precompute the limit of the stack as used in stack overflow checks.
1166 // We load it from here to simplify the stack overflow check in assembly.
1167 address _stack_overflow_limit;
1168 address _reserved_stack_activation;
1169
1170 // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
1171 // used to temp. parsing values into and out of the runtime system during exception handling for compiled
1172 // code)
1173 volatile oop _exception_oop; // Exception thrown in compiled code
1174 volatile address _exception_pc; // PC where exception happened
1175 volatile address _exception_handler_pc; // PC for handler of exception
1176 volatile int _is_method_handle_return; // true (== 1) if the current exception PC is a MethodHandle call site.
1177
1178 private:
1179 // support for JNI critical regions
1180 jint _jni_active_critical; // count of entries into JNI critical region
1181
1182 // Checked JNI: function name requires exception check
1183 char* _pending_jni_exception_check_fn;
1184
1185 // For deadlock detection.
1186 int _depth_first_number;
1187
1188 // JVMTI PopFrame support
1189 // This is set to popframe_pending to signal that top Java frame should be popped immediately
1190 int _popframe_condition;
1191
1192 // If reallocation of scalar replaced objects fails, we throw OOM
1193 // and during exception propagation, pop the top
1194 // _frames_to_pop_failed_realloc frames, the ones that reference
1195 // failed reallocations.
1196 int _frames_to_pop_failed_realloc;
1197
1198 friend class VMThread;
1199 friend class ThreadWaitTransition;
1200 friend class VM_Exit;
1201
1202 void initialize(); // Initialized the instance variables
1203
1204 public:
1205 // Constructor
1206 JavaThread(bool is_attaching_via_jni = false); // for main thread and JNI attached threads
1207 JavaThread(ThreadFunction entry_point, size_t stack_size = 0);
1208 ~JavaThread();
1209
1210 #ifdef ASSERT
1211 // verify this JavaThread hasn't be published in the Threads::list yet
1212 void verify_not_published();
1213 #endif // ASSERT
1214
1215 //JNI functiontable getter/setter for JVMTI jni function table interception API.
1216 void set_jni_functions(struct JNINativeInterface_* functionTable) {
1217 _jni_environment.functions = functionTable;
1218 }
1219 struct JNINativeInterface_* get_jni_functions() {
1220 return (struct JNINativeInterface_ *)_jni_environment.functions;
1221 }
1222
1223 // This function is called at thread creation to allow
1224 // platform specific thread variables to be initialized.
1225 void cache_global_variables();
1226
1227 // Executes Shutdown.shutdown()
1228 void invoke_shutdown_hooks();
1229
1230 // Cleanup on thread exit
1231 enum ExitType {
1232 normal_exit,
1233 jni_detach
1234 };
1235 void exit(bool destroy_vm, ExitType exit_type = normal_exit);
1236
1237 void cleanup_failed_attach_current_thread(bool is_daemon);
1238
1239 // Testers
1240 virtual bool is_Java_thread() const { return true; }
1241 virtual bool can_call_java() const { return true; }
1242
1243 virtual bool is_active_Java_thread() const {
1244 return on_thread_list() && !is_terminated();
1245 }
1246
1247 // Thread oop. threadObj() can be NULL for initial JavaThread
1248 // (or for threads attached via JNI)
1249 oop threadObj() const { return _threadObj; }
1250 void set_threadObj(oop p) { _threadObj = p; }
1251
1252 // Prepare thread and add to priority queue. If a priority is
1253 // not specified, use the priority of the thread object. Threads_lock
1254 // must be held while this function is called.
1255 void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
1256
1257 void set_saved_exception_pc(address pc) { _saved_exception_pc = pc; }
1258 address saved_exception_pc() { return _saved_exception_pc; }
1259
1260
1261 ThreadFunction entry_point() const { return _entry_point; }
1262
1263 // Allocates a new Java level thread object for this thread. thread_name may be NULL.
1264 void allocate_threadObj(Handle thread_group, const char* thread_name, bool daemon, TRAPS);
1265
1266 // Last frame anchor routines
1267
1268 JavaFrameAnchor* frame_anchor(void) { return &_anchor; }
1269
1270 // last_Java_sp
1271 bool has_last_Java_frame() const { return _anchor.has_last_Java_frame(); }
1272 intptr_t* last_Java_sp() const { return _anchor.last_Java_sp(); }
1273
1274 // last_Java_pc
1275
1276 address last_Java_pc(void) { return _anchor.last_Java_pc(); }
1277
1278 // Safepoint support
1279 inline JavaThreadState thread_state() const;
1280 inline void set_thread_state(JavaThreadState s);
1281 inline void set_thread_state_fence(JavaThreadState s); // fence after setting thread state
1282 inline ThreadSafepointState* safepoint_state() const;
1283 inline void set_safepoint_state(ThreadSafepointState* state);
1284 inline bool is_at_poll_safepoint();
1285
1286 // JavaThread termination and lifecycle support:
1287 void smr_delete();
1288 bool on_thread_list() const { return _on_thread_list; }
1289 void set_on_thread_list() { _on_thread_list = true; }
1290
1291 // thread has called JavaThread::exit() or is terminated
1292 bool is_exiting() const;
1293 // thread is terminated (no longer on the threads list); we compare
1294 // against the two non-terminated values so that a freed JavaThread
1295 // will also be considered terminated.
1296 bool check_is_terminated(TerminatedTypes l_terminated) const {
1297 return l_terminated != _not_terminated && l_terminated != _thread_exiting;
1298 }
1299 bool is_terminated() const;
1300 void set_terminated(TerminatedTypes t);
1301 // special for Threads::remove() which is static:
1302 void set_terminated_value();
1303 void block_if_vm_exited();
1304
1305 bool doing_unsafe_access() { return _doing_unsafe_access; }
1306 void set_doing_unsafe_access(bool val) { _doing_unsafe_access = val; }
1307
1308 bool do_not_unlock_if_synchronized() { return _do_not_unlock_if_synchronized; }
1309 void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
1310
1311 inline void set_polling_page_release(void* poll_value);
1312 inline void set_polling_page(void* poll_value);
1313 inline volatile void* get_polling_page();
1314
1315 private:
1316 // Support for thread handshake operations
1317 HandshakeState _handshake;
1318 public:
1319 void set_handshake_operation(HandshakeOperation* op) {
1320 _handshake.set_operation(this, op);
1321 }
1322
1323 bool has_handshake() const {
1324 return _handshake.has_operation();
1325 }
1326
1327 void handshake_process_by_self() {
1328 _handshake.process_by_self(this);
1329 }
1330
1331 bool handshake_try_process_by_vmThread() {
1332 return _handshake.try_process_by_vmThread(this);
1333 }
1334
1335 // Suspend/resume support for JavaThread
1336 private:
1337 inline void set_ext_suspended();
1338 inline void clear_ext_suspended();
1339
1340 public:
1341 void java_suspend(); // higher-level suspension logic called by the public APIs
1342 void java_resume(); // higher-level resume logic called by the public APIs
1343 int java_suspend_self(); // low-level self-suspension mechanics
1344
1345 private:
1346 // mid-level wrapper around java_suspend_self to set up correct state and
1347 // check for a pending safepoint at the end
1348 void java_suspend_self_with_safepoint_check();
1349
1350 public:
1351 void check_and_wait_while_suspended() {
1352 assert(JavaThread::current() == this, "sanity check");
1353
1354 bool do_self_suspend;
1355 do {
1356 // were we externally suspended while we were waiting?
1357 do_self_suspend = handle_special_suspend_equivalent_condition();
1358 if (do_self_suspend) {
1359 // don't surprise the thread that suspended us by returning
1360 java_suspend_self();
1361 set_suspend_equivalent();
1362 }
1363 } while (do_self_suspend);
1364 }
1365 static void check_safepoint_and_suspend_for_native_trans(JavaThread *thread);
1366 // Check for async exception in addition to safepoint and suspend request.
1367 static void check_special_condition_for_native_trans(JavaThread *thread);
1368
1369 // Same as check_special_condition_for_native_trans but finishes the
1370 // transition into thread_in_Java mode so that it can potentially
1371 // block.
1372 static void check_special_condition_for_native_trans_and_transition(JavaThread *thread);
1373
1374 bool is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits);
1375 bool is_ext_suspend_completed_with_lock(uint32_t *bits) {
1376 MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1377 // Warning: is_ext_suspend_completed() may temporarily drop the
1378 // SR_lock to allow the thread to reach a stable thread state if
1379 // it is currently in a transient thread state.
1380 return is_ext_suspend_completed(false /* !called_by_wait */,
1381 SuspendRetryDelay, bits);
1382 }
1383
1384 // We cannot allow wait_for_ext_suspend_completion() to run forever or
1385 // we could hang. SuspendRetryCount and SuspendRetryDelay are normally
1386 // passed as the count and delay parameters. Experiments with specific
1387 // calls to wait_for_ext_suspend_completion() can be done by passing
1388 // other values in the code. Experiments with all calls can be done
1389 // via the appropriate -XX options.
1390 bool wait_for_ext_suspend_completion(int count, int delay, uint32_t *bits);
1391
1392 // test for suspend - most (all?) of these should go away
1393 bool is_thread_fully_suspended(bool wait_for_suspend, uint32_t *bits);
1394
1395 inline void set_external_suspend();
1396 inline void clear_external_suspend();
1397
1398 bool is_external_suspend() const {
1399 return (_suspend_flags & _external_suspend) != 0;
1400 }
1401 // Whenever a thread transitions from native to vm/java it must suspend
1402 // if external|deopt suspend is present.
1403 bool is_suspend_after_native() const {
1404 return (_suspend_flags & (_external_suspend JFR_ONLY(| _trace_flag))) != 0;
1405 }
1406
1407 // external suspend request is completed
1408 bool is_ext_suspended() const {
1409 return (_suspend_flags & _ext_suspended) != 0;
1410 }
1411
1412 bool is_external_suspend_with_lock() const {
1413 MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1414 return is_external_suspend();
1415 }
1416
1417 // Special method to handle a pending external suspend request
1418 // when a suspend equivalent condition lifts.
1419 bool handle_special_suspend_equivalent_condition() {
1420 assert(is_suspend_equivalent(),
1421 "should only be called in a suspend equivalence condition");
1422 MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1423 bool ret = is_external_suspend();
1424 if (!ret) {
1425 // not about to self-suspend so clear suspend equivalence
1426 clear_suspend_equivalent();
1427 }
1428 // implied else:
1429 // We have a pending external suspend request so we leave the
1430 // suspend_equivalent flag set until java_suspend_self() sets
1431 // the ext_suspended flag and clears the suspend_equivalent
1432 // flag. This insures that wait_for_ext_suspend_completion()
1433 // will return consistent values.
1434 return ret;
1435 }
1436
1437 // utility methods to see if we are doing some kind of suspension
1438 bool is_being_ext_suspended() const {
1439 MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1440 return is_ext_suspended() || is_external_suspend();
1441 }
1442
1443 bool is_suspend_equivalent() const { return _suspend_equivalent; }
1444
1445 void set_suspend_equivalent() { _suspend_equivalent = true; }
1446 void clear_suspend_equivalent() { _suspend_equivalent = false; }
1447
1448 // Thread.stop support
1449 void send_thread_stop(oop throwable);
1450 AsyncRequests clear_special_runtime_exit_condition() {
1451 AsyncRequests x = _special_runtime_exit_condition;
1452 _special_runtime_exit_condition = _no_async_condition;
1453 return x;
1454 }
1455
1456 // Are any async conditions present?
1457 bool has_async_condition() { return (_special_runtime_exit_condition != _no_async_condition); }
1458
1459 void check_and_handle_async_exceptions(bool check_unsafe_error = true);
1460
1461 // these next two are also used for self-suspension and async exception support
1462 void handle_special_runtime_exit_condition(bool check_asyncs = true);
1463
1464 // Return true if JavaThread has an asynchronous condition or
1465 // if external suspension is requested.
1466 bool has_special_runtime_exit_condition() {
1467 // Because we don't use is_external_suspend_with_lock
1468 // it is possible that we won't see an asynchronous external suspend
1469 // request that has just gotten started, i.e., SR_lock grabbed but
1470 // _external_suspend field change either not made yet or not visible
1471 // yet. However, this is okay because the request is asynchronous and
1472 // we will see the new flag value the next time through. It's also
1473 // possible that the external suspend request is dropped after
1474 // we have checked is_external_suspend(), we will recheck its value
1475 // under SR_lock in java_suspend_self().
1476 return (_special_runtime_exit_condition != _no_async_condition) ||
1477 is_external_suspend() || is_trace_suspend();
1478 }
1479
1480 void set_pending_unsafe_access_error() { _special_runtime_exit_condition = _async_unsafe_access_error; }
1481
1482 inline void set_pending_async_exception(oop e);
1483
1484 // Fast-locking support
1485 bool is_lock_owned(address adr) const;
1486
1487 // Accessors for vframe array top
1488 // The linked list of vframe arrays are sorted on sp. This means when we
1489 // unpack the head must contain the vframe array to unpack.
1490 void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
1491 vframeArray* vframe_array_head() const { return _vframe_array_head; }
1492
1493 // Side structure for deferring update of java frame locals until deopt occurs
1494 GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred_locals() const { return _deferred_locals_updates; }
1495 void set_deferred_locals(GrowableArray<jvmtiDeferredLocalVariableSet *>* vf) { _deferred_locals_updates = vf; }
1496
1497 // These only really exist to make debugging deopt problems simpler
1498
1499 void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
1500 vframeArray* vframe_array_last() const { return _vframe_array_last; }
1501
1502 // The special resourceMark used during deoptimization
1503
1504 void set_deopt_mark(DeoptResourceMark* value) { _deopt_mark = value; }
1505 DeoptResourceMark* deopt_mark(void) { return _deopt_mark; }
1506
1507 void set_deopt_compiled_method(CompiledMethod* nm) { _deopt_nmethod = nm; }
1508 CompiledMethod* deopt_compiled_method() { return _deopt_nmethod; }
1509
1510 Method* callee_target() const { return _callee_target; }
1511 void set_callee_target (Method* x) { _callee_target = x; }
1512
1513 // Oop results of vm runtime calls
1514 oop vm_result() const { return _vm_result; }
1515 void set_vm_result (oop x) { _vm_result = x; }
1516
1517 Metadata* vm_result_2() const { return _vm_result_2; }
1518 void set_vm_result_2 (Metadata* x) { _vm_result_2 = x; }
1519
1520 MemRegion deferred_card_mark() const { return _deferred_card_mark; }
1521 void set_deferred_card_mark(MemRegion mr) { _deferred_card_mark = mr; }
1522
1523 #if INCLUDE_JVMCI
1524 int pending_deoptimization() const { return _pending_deoptimization; }
1525 jlong pending_failed_speculation() const { return _pending_failed_speculation; }
1526 bool has_pending_monitorenter() const { return _pending_monitorenter; }
1527 void set_pending_monitorenter(bool b) { _pending_monitorenter = b; }
1528 void set_pending_deoptimization(int reason) { _pending_deoptimization = reason; }
1529 void set_pending_failed_speculation(jlong failed_speculation) { _pending_failed_speculation = failed_speculation; }
1530 void set_pending_transfer_to_interpreter(bool b) { _pending_transfer_to_interpreter = b; }
1531 void set_jvmci_alternate_call_target(address a) { assert(_jvmci._alternate_call_target == NULL, "must be"); _jvmci._alternate_call_target = a; }
1532 void set_jvmci_implicit_exception_pc(address a) { assert(_jvmci._implicit_exception_pc == NULL, "must be"); _jvmci._implicit_exception_pc = a; }
1533
1534 virtual bool in_retryable_allocation() const { return _in_retryable_allocation; }
1535 void set_in_retryable_allocation(bool b) { _in_retryable_allocation = b; }
1536 #endif // INCLUDE_JVMCI
1537
1538 // Exception handling for compiled methods
1539 oop exception_oop() const { return _exception_oop; }
1540 address exception_pc() const { return _exception_pc; }
1541 address exception_handler_pc() const { return _exception_handler_pc; }
1542 bool is_method_handle_return() const { return _is_method_handle_return == 1; }
1543
1544 void set_exception_oop(oop o) { (void)const_cast<oop&>(_exception_oop = o); }
1545 void set_exception_pc(address a) { _exception_pc = a; }
1546 void set_exception_handler_pc(address a) { _exception_handler_pc = a; }
1547 void set_is_method_handle_return(bool value) { _is_method_handle_return = value ? 1 : 0; }
1548
1549 void clear_exception_oop_and_pc() {
1550 set_exception_oop(NULL);
1551 set_exception_pc(NULL);
1552 }
1553
1554 // Stack overflow support
1555 //
1556 // (small addresses)
1557 //
1558 // -- <-- stack_end() ---
1559 // | |
1560 // | red pages |
1561 // | |
1562 // -- <-- stack_red_zone_base() |
1563 // | |
1564 // | guard
1565 // | yellow pages zone
1566 // | |
1567 // | |
1568 // -- <-- stack_yellow_zone_base() |
1569 // | |
1570 // | |
1571 // | reserved pages |
1572 // | |
1573 // -- <-- stack_reserved_zone_base() --- ---
1574 // /|\ shadow <-- stack_overflow_limit() (somewhere in here)
1575 // | zone
1576 // \|/ size
1577 // some untouched memory ---
1578 //
1579 //
1580 // --
1581 // |
1582 // | shadow zone
1583 // |
1584 // --
1585 // x frame n
1586 // --
1587 // x frame n-1
1588 // x
1589 // --
1590 // ...
1591 //
1592 // --
1593 // x frame 0
1594 // -- <-- stack_base()
1595 //
1596 // (large addresses)
1597 //
1598
1599 private:
1600 // These values are derived from flags StackRedPages, StackYellowPages,
1601 // StackReservedPages and StackShadowPages. The zone size is determined
1602 // ergonomically if page_size > 4K.
1603 static size_t _stack_red_zone_size;
1604 static size_t _stack_yellow_zone_size;
1605 static size_t _stack_reserved_zone_size;
1606 static size_t _stack_shadow_zone_size;
1607 public:
1608 inline size_t stack_available(address cur_sp);
1609
1610 static size_t stack_red_zone_size() {
1611 assert(_stack_red_zone_size > 0, "Don't call this before the field is initialized.");
1612 return _stack_red_zone_size;
1613 }
1614 static void set_stack_red_zone_size(size_t s) {
1615 assert(is_aligned(s, os::vm_page_size()),
1616 "We can not protect if the red zone size is not page aligned.");
1617 assert(_stack_red_zone_size == 0, "This should be called only once.");
1618 _stack_red_zone_size = s;
1619 }
1620 address stack_red_zone_base() {
1621 return (address)(stack_end() + stack_red_zone_size());
1622 }
1623 bool in_stack_red_zone(address a) {
1624 return a <= stack_red_zone_base() && a >= stack_end();
1625 }
1626
1627 static size_t stack_yellow_zone_size() {
1628 assert(_stack_yellow_zone_size > 0, "Don't call this before the field is initialized.");
1629 return _stack_yellow_zone_size;
1630 }
1631 static void set_stack_yellow_zone_size(size_t s) {
1632 assert(is_aligned(s, os::vm_page_size()),
1633 "We can not protect if the yellow zone size is not page aligned.");
1634 assert(_stack_yellow_zone_size == 0, "This should be called only once.");
1635 _stack_yellow_zone_size = s;
1636 }
1637
1638 static size_t stack_reserved_zone_size() {
1639 // _stack_reserved_zone_size may be 0. This indicates the feature is off.
1640 return _stack_reserved_zone_size;
1641 }
1642 static void set_stack_reserved_zone_size(size_t s) {
1643 assert(is_aligned(s, os::vm_page_size()),
1644 "We can not protect if the reserved zone size is not page aligned.");
1645 assert(_stack_reserved_zone_size == 0, "This should be called only once.");
1646 _stack_reserved_zone_size = s;
1647 }
1648 address stack_reserved_zone_base() {
1649 return (address)(stack_end() +
1650 (stack_red_zone_size() + stack_yellow_zone_size() + stack_reserved_zone_size()));
1651 }
1652 bool in_stack_reserved_zone(address a) {
1653 return (a <= stack_reserved_zone_base()) &&
1654 (a >= (address)((intptr_t)stack_reserved_zone_base() - stack_reserved_zone_size()));
1655 }
1656
1657 static size_t stack_yellow_reserved_zone_size() {
1658 return _stack_yellow_zone_size + _stack_reserved_zone_size;
1659 }
1660 bool in_stack_yellow_reserved_zone(address a) {
1661 return (a <= stack_reserved_zone_base()) && (a >= stack_red_zone_base());
1662 }
1663
1664 // Size of red + yellow + reserved zones.
1665 static size_t stack_guard_zone_size() {
1666 return stack_red_zone_size() + stack_yellow_reserved_zone_size();
1667 }
1668
1669 static size_t stack_shadow_zone_size() {
1670 assert(_stack_shadow_zone_size > 0, "Don't call this before the field is initialized.");
1671 return _stack_shadow_zone_size;
1672 }
1673 static void set_stack_shadow_zone_size(size_t s) {
1674 // The shadow area is not allocated or protected, so
1675 // it needs not be page aligned.
1676 // But the stack bang currently assumes that it is a
1677 // multiple of page size. This guarantees that the bang
1678 // loop touches all pages in the shadow zone.
1679 // This can be guaranteed differently, as well. E.g., if
1680 // the page size is a multiple of 4K, banging in 4K steps
1681 // suffices to touch all pages. (Some pages are banged
1682 // several times, though.)
1683 assert(is_aligned(s, os::vm_page_size()),
1684 "Stack bang assumes multiple of page size.");
1685 assert(_stack_shadow_zone_size == 0, "This should be called only once.");
1686 _stack_shadow_zone_size = s;
1687 }
1688
1689 void create_stack_guard_pages();
1690 void remove_stack_guard_pages();
1691
1692 void enable_stack_reserved_zone();
1693 void disable_stack_reserved_zone();
1694 void enable_stack_yellow_reserved_zone();
1695 void disable_stack_yellow_reserved_zone();
1696 void enable_stack_red_zone();
1697 void disable_stack_red_zone();
1698
1699 inline bool stack_guard_zone_unused();
1700 inline bool stack_yellow_reserved_zone_disabled();
1701 inline bool stack_reserved_zone_disabled();
1702 inline bool stack_guards_enabled();
1703
1704 address reserved_stack_activation() const { return _reserved_stack_activation; }
1705 void set_reserved_stack_activation(address addr) {
1706 assert(_reserved_stack_activation == stack_base()
1707 || _reserved_stack_activation == NULL
1708 || addr == stack_base(), "Must not be set twice");
1709 _reserved_stack_activation = addr;
1710 }
1711
1712 // Attempt to reguard the stack after a stack overflow may have occurred.
1713 // Returns true if (a) guard pages are not needed on this thread, (b) the
1714 // pages are already guarded, or (c) the pages were successfully reguarded.
1715 // Returns false if there is not enough stack space to reguard the pages, in
1716 // which case the caller should unwind a frame and try again. The argument
1717 // should be the caller's (approximate) sp.
1718 bool reguard_stack(address cur_sp);
1719 // Similar to above but see if current stackpoint is out of the guard area
1720 // and reguard if possible.
1721 bool reguard_stack(void);
1722
1723 address stack_overflow_limit() { return _stack_overflow_limit; }
1724 void set_stack_overflow_limit() {
1725 _stack_overflow_limit =
1726 stack_end() + MAX2(JavaThread::stack_guard_zone_size(), JavaThread::stack_shadow_zone_size());
1727 }
1728
1729 // Misc. accessors/mutators
1730 void set_do_not_unlock(void) { _do_not_unlock_if_synchronized = true; }
1731 void clr_do_not_unlock(void) { _do_not_unlock_if_synchronized = false; }
1732 bool do_not_unlock(void) { return _do_not_unlock_if_synchronized; }
1733
1734 // For assembly stub generation
1735 static ByteSize threadObj_offset() { return byte_offset_of(JavaThread, _threadObj); }
1736 static ByteSize jni_environment_offset() { return byte_offset_of(JavaThread, _jni_environment); }
1737 static ByteSize pending_jni_exception_check_fn_offset() {
1738 return byte_offset_of(JavaThread, _pending_jni_exception_check_fn);
1739 }
1740 static ByteSize last_Java_sp_offset() {
1741 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
1742 }
1743 static ByteSize last_Java_pc_offset() {
1744 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
1745 }
1746 static ByteSize frame_anchor_offset() {
1747 return byte_offset_of(JavaThread, _anchor);
1748 }
1749 static ByteSize callee_target_offset() { return byte_offset_of(JavaThread, _callee_target); }
1750 static ByteSize vm_result_offset() { return byte_offset_of(JavaThread, _vm_result); }
1751 static ByteSize vm_result_2_offset() { return byte_offset_of(JavaThread, _vm_result_2); }
1752 static ByteSize thread_state_offset() { return byte_offset_of(JavaThread, _thread_state); }
1753 static ByteSize saved_exception_pc_offset() { return byte_offset_of(JavaThread, _saved_exception_pc); }
1754 static ByteSize osthread_offset() { return byte_offset_of(JavaThread, _osthread); }
1755 #if INCLUDE_JVMCI
1756 static ByteSize pending_deoptimization_offset() { return byte_offset_of(JavaThread, _pending_deoptimization); }
1757 static ByteSize pending_monitorenter_offset() { return byte_offset_of(JavaThread, _pending_monitorenter); }
1758 static ByteSize pending_failed_speculation_offset() { return byte_offset_of(JavaThread, _pending_failed_speculation); }
1759 static ByteSize jvmci_alternate_call_target_offset() { return byte_offset_of(JavaThread, _jvmci._alternate_call_target); }
1760 static ByteSize jvmci_implicit_exception_pc_offset() { return byte_offset_of(JavaThread, _jvmci._implicit_exception_pc); }
1761 static ByteSize jvmci_counters_offset() { return byte_offset_of(JavaThread, _jvmci_counters); }
1762 #endif // INCLUDE_JVMCI
1763 static ByteSize exception_oop_offset() { return byte_offset_of(JavaThread, _exception_oop); }
1764 static ByteSize exception_pc_offset() { return byte_offset_of(JavaThread, _exception_pc); }
1765 static ByteSize exception_handler_pc_offset() { return byte_offset_of(JavaThread, _exception_handler_pc); }
1766 static ByteSize stack_overflow_limit_offset() { return byte_offset_of(JavaThread, _stack_overflow_limit); }
1767 static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); }
1768 static ByteSize stack_guard_state_offset() { return byte_offset_of(JavaThread, _stack_guard_state); }
1769 static ByteSize reserved_stack_activation_offset() { return byte_offset_of(JavaThread, _reserved_stack_activation); }
1770 static ByteSize suspend_flags_offset() { return byte_offset_of(JavaThread, _suspend_flags); }
1771
1772 static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
1773 static ByteSize should_post_on_exceptions_flag_offset() {
1774 return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
1775 }
1776 static ByteSize doing_unsafe_access_offset() { return byte_offset_of(JavaThread, _doing_unsafe_access); }
1777
1778 // Returns the jni environment for this thread
1779 JNIEnv* jni_environment() { return &_jni_environment; }
1780
1781 static JavaThread* thread_from_jni_environment(JNIEnv* env) {
1782 JavaThread *thread_from_jni_env = (JavaThread*)((intptr_t)env - in_bytes(jni_environment_offset()));
1783 // Only return NULL if thread is off the thread list; starting to
1784 // exit should not return NULL.
1785 if (thread_from_jni_env->is_terminated()) {
1786 thread_from_jni_env->block_if_vm_exited();
1787 return NULL;
1788 } else {
1789 return thread_from_jni_env;
1790 }
1791 }
1792
1793 // JNI critical regions. These can nest.
1794 bool in_critical() { return _jni_active_critical > 0; }
1795 bool in_last_critical() { return _jni_active_critical == 1; }
1796 inline void enter_critical();
1797 void exit_critical() {
1798 assert(Thread::current() == this, "this must be current thread");
1799 _jni_active_critical--;
1800 assert(_jni_active_critical >= 0, "JNI critical nesting problem?");
1801 }
1802
1803 // Checked JNI: is the programmer required to check for exceptions, if so specify
1804 // which function name. Returning to a Java frame should implicitly clear the
1805 // pending check, this is done for Native->Java transitions (i.e. user JNI code).
1806 // VM->Java transistions are not cleared, it is expected that JNI code enclosed
1807 // within ThreadToNativeFromVM makes proper exception checks (i.e. VM internal).
1808 bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != NULL; }
1809 void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = NULL; }
1810 const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; }
1811 void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; }
1812
1813 // For deadlock detection
1814 int depth_first_number() { return _depth_first_number; }
1815 void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
1816
1817 private:
1818 void set_monitor_chunks(MonitorChunk* monitor_chunks) { _monitor_chunks = monitor_chunks; }
1819
1820 public:
1821 MonitorChunk* monitor_chunks() const { return _monitor_chunks; }
1822 void add_monitor_chunk(MonitorChunk* chunk);
1823 void remove_monitor_chunk(MonitorChunk* chunk);
1824 bool in_deopt_handler() const { return _in_deopt_handler > 0; }
1825 void inc_in_deopt_handler() { _in_deopt_handler++; }
1826 void dec_in_deopt_handler() {
1827 assert(_in_deopt_handler > 0, "mismatched deopt nesting");
1828 if (_in_deopt_handler > 0) { // robustness
1829 _in_deopt_handler--;
1830 }
1831 }
1832
1833 private:
1834 void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
1835
1836 public:
1837
1838 // Frame iteration; calls the function f for all frames on the stack
1839 void frames_do(void f(frame*, const RegisterMap*));
1840
1841 // Memory operations
1842 void oops_do(OopClosure* f, CodeBlobClosure* cf);
1843
1844 // Sweeper operations
1845 virtual void nmethods_do(CodeBlobClosure* cf);
1846
1847 // RedefineClasses Support
1848 void metadata_do(MetadataClosure* f);
1849
1850 // Debug method asserting thread states are correct during a handshake operation.
1851 DEBUG_ONLY(void verify_states_for_handshake();)
1852
1853 // Misc. operations
1854 char* name() const { return (char*)get_thread_name(); }
1855 void print_on(outputStream* st, bool print_extended_info) const;
1856 void print_on(outputStream* st) const { print_on(st, false); }
1857 void print() const;
1858 void print_thread_state_on(outputStream*) const PRODUCT_RETURN;
1859 void print_on_error(outputStream* st, char* buf, int buflen) const;
1860 void print_name_on_error(outputStream* st, char* buf, int buflen) const;
1861 void verify();
1862 const char* get_thread_name() const;
1863 protected:
1864 // factor out low-level mechanics for use in both normal and error cases
1865 virtual const char* get_thread_name_string(char* buf = NULL, int buflen = 0) const;
1866 public:
1867 // Accessing frames
1868 frame last_frame() {
1869 _anchor.make_walkable(this);
1870 return pd_last_frame();
1871 }
1872 javaVFrame* last_java_vframe(RegisterMap* reg_map);
1873
1874 // Returns method at 'depth' java or native frames down the stack
1875 // Used for security checks
1876 Klass* security_get_caller_class(int depth);
1877
1878 // Print stack trace in external format
1879 void print_stack_on(outputStream* st);
1880 void print_stack() { print_stack_on(tty); }
1881
1882 // Print stack traces in various internal formats
1883 void trace_stack() PRODUCT_RETURN;
1884 void trace_stack_from(vframe* start_vf) PRODUCT_RETURN;
1885 void trace_frames() PRODUCT_RETURN;
1886
1887 // Print an annotated view of the stack frames
1888 void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN;
1889 void validate_frame_layout() {
1890 print_frame_layout(0, true);
1891 }
1892
1893 // Function for testing deoptimization
1894 void deoptimize();
1895 void make_zombies();
1896
1897 void deoptimize_marked_methods();
1898
1899 public:
1900 // Returns the running thread as a JavaThread
1901 static inline JavaThread* current();
1902
1903 // Returns the active Java thread. Do not use this if you know you are calling
1904 // from a JavaThread, as it's slower than JavaThread::current. If called from
1905 // the VMThread, it also returns the JavaThread that instigated the VMThread's
1906 // operation. You may not want that either.
1907 static JavaThread* active();
1908
1909 inline CompilerThread* as_CompilerThread();
1910
1911 protected:
1912 virtual void pre_run();
1913 virtual void run();
1914 void thread_main_inner();
1915 virtual void post_run();
1916
1917
1918 private:
1919 GrowableArray<oop>* _array_for_gc;
1920 public:
1921
1922 void register_array_for_gc(GrowableArray<oop>* array) { _array_for_gc = array; }
1923
1924 public:
1925 // Thread local information maintained by JVMTI.
1926 void set_jvmti_thread_state(JvmtiThreadState *value) { _jvmti_thread_state = value; }
1927 // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1928 // getter is used to get this JavaThread's JvmtiThreadState if it has
1929 // one which means NULL can be returned. JvmtiThreadState::state_for()
1930 // is used to get the specified JavaThread's JvmtiThreadState if it has
1931 // one or it allocates a new JvmtiThreadState for the JavaThread and
1932 // returns it. JvmtiThreadState::state_for() will return NULL only if
1933 // the specified JavaThread is exiting.
1934 JvmtiThreadState *jvmti_thread_state() const { return _jvmti_thread_state; }
1935 static ByteSize jvmti_thread_state_offset() { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1936
1937 // JVMTI PopFrame support
1938 // Setting and clearing popframe_condition
1939 // All of these enumerated values are bits. popframe_pending
1940 // indicates that a PopFrame() has been requested and not yet been
1941 // completed. popframe_processing indicates that that PopFrame() is in
1942 // the process of being completed. popframe_force_deopt_reexecution_bit
1943 // indicates that special handling is required when returning to a
1944 // deoptimized caller.
1945 enum PopCondition {
1946 popframe_inactive = 0x00,
1947 popframe_pending_bit = 0x01,
1948 popframe_processing_bit = 0x02,
1949 popframe_force_deopt_reexecution_bit = 0x04
1950 };
1951 PopCondition popframe_condition() { return (PopCondition) _popframe_condition; }
1952 void set_popframe_condition(PopCondition c) { _popframe_condition = c; }
1953 void set_popframe_condition_bit(PopCondition c) { _popframe_condition |= c; }
1954 void clear_popframe_condition() { _popframe_condition = popframe_inactive; }
1955 static ByteSize popframe_condition_offset() { return byte_offset_of(JavaThread, _popframe_condition); }
1956 bool has_pending_popframe() { return (popframe_condition() & popframe_pending_bit) != 0; }
1957 bool popframe_forcing_deopt_reexecution() { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
1958 void clear_popframe_forcing_deopt_reexecution() { _popframe_condition &= ~popframe_force_deopt_reexecution_bit; }
1959 #ifdef CC_INTERP
1960 bool pop_frame_pending(void) { return ((_popframe_condition & popframe_pending_bit) != 0); }
1961 void clr_pop_frame_pending(void) { _popframe_condition = popframe_inactive; }
1962 bool pop_frame_in_process(void) { return ((_popframe_condition & popframe_processing_bit) != 0); }
1963 void set_pop_frame_in_process(void) { _popframe_condition |= popframe_processing_bit; }
1964 void clr_pop_frame_in_process(void) { _popframe_condition &= ~popframe_processing_bit; }
1965 #endif
1966
1967 int frames_to_pop_failed_realloc() const { return _frames_to_pop_failed_realloc; }
1968 void set_frames_to_pop_failed_realloc(int nb) { _frames_to_pop_failed_realloc = nb; }
1969 void dec_frames_to_pop_failed_realloc() { _frames_to_pop_failed_realloc--; }
1970
1971 private:
1972 // Saved incoming arguments to popped frame.
1973 // Used only when popped interpreted frame returns to deoptimized frame.
1974 void* _popframe_preserved_args;
1975 int _popframe_preserved_args_size;
1976
1977 public:
1978 void popframe_preserve_args(ByteSize size_in_bytes, void* start);
1979 void* popframe_preserved_args();
1980 ByteSize popframe_preserved_args_size();
1981 WordSize popframe_preserved_args_size_in_words();
1982 void popframe_free_preserved_args();
1983
1984
1985 private:
1986 JvmtiThreadState *_jvmti_thread_state;
1987
1988 // Used by the interpreter in fullspeed mode for frame pop, method
1989 // entry, method exit and single stepping support. This field is
1990 // only set to non-zero by the VM_EnterInterpOnlyMode VM operation.
1991 // It can be set to zero asynchronously (i.e., without a VM operation
1992 // or a lock) so we have to be very careful.
1993 int _interp_only_mode;
1994
1995 public:
1996 // used by the interpreter for fullspeed debugging support (see above)
1997 static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
1998 bool is_interp_only_mode() { return (_interp_only_mode != 0); }
1999 int get_interp_only_mode() { return _interp_only_mode; }
2000 void increment_interp_only_mode() { ++_interp_only_mode; }
2001 void decrement_interp_only_mode() { --_interp_only_mode; }
2002
2003 // support for cached flag that indicates whether exceptions need to be posted for this thread
2004 // if this is false, we can avoid deoptimizing when events are thrown
2005 // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
2006 private:
2007 int _should_post_on_exceptions_flag;
2008
2009 public:
2010 int should_post_on_exceptions_flag() { return _should_post_on_exceptions_flag; }
2011 void set_should_post_on_exceptions_flag(int val) { _should_post_on_exceptions_flag = val; }
2012
2013 private:
2014 ThreadStatistics *_thread_stat;
2015
2016 public:
2017 ThreadStatistics* get_thread_stat() const { return _thread_stat; }
2018
2019 // Return a blocker object for which this thread is blocked parking.
2020 oop current_park_blocker();
2021
2022 private:
2023 static size_t _stack_size_at_create;
2024
2025 public:
2026 static inline size_t stack_size_at_create(void) {
2027 return _stack_size_at_create;
2028 }
2029 static inline void set_stack_size_at_create(size_t value) {
2030 _stack_size_at_create = value;
2031 }
2032
2033 // Machine dependent stuff
2034 #include OS_CPU_HEADER(thread)
2035
2036 // JSR166 per-thread parker
2037 private:
2038 Parker* _parker;
2039 public:
2040 Parker* parker() { return _parker; }
2041
2042 // Biased locking support
2043 private:
2044 GrowableArray<MonitorInfo*>* _cached_monitor_info;
2045 public:
2046 GrowableArray<MonitorInfo*>* cached_monitor_info() { return _cached_monitor_info; }
2047 void set_cached_monitor_info(GrowableArray<MonitorInfo*>* info) { _cached_monitor_info = info; }
2048
2049 // clearing/querying jni attach status
2050 bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; }
2051 bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
2052 inline void set_done_attaching_via_jni();
2053
2054 // Stack dump assistance:
2055 // Track the class we want to initialize but for which we have to wait
2056 // on its init_lock() because it is already being initialized.
2057 void set_class_to_be_initialized(InstanceKlass* k);
2058 InstanceKlass* class_to_be_initialized() const;
2059
2060 private:
2061 InstanceKlass* _class_to_be_initialized;
2062
2063 // java.lang.Thread.sleep support
2064 ParkEvent * _SleepEvent;
2065 public:
2066 bool sleep(jlong millis);
2067
2068 // java.lang.Thread interruption support
2069 void interrupt();
2070 bool is_interrupted(bool clear_interrupted);
2071
2072 };
2073
2074 // Inline implementation of JavaThread::current
2075 inline JavaThread* JavaThread::current() {
2076 Thread* thread = Thread::current();
2077 assert(thread->is_Java_thread(), "just checking");
2078 return (JavaThread*)thread;
2079 }
2080
2081 inline CompilerThread* JavaThread::as_CompilerThread() {
2082 assert(is_Compiler_thread(), "just checking");
2083 return (CompilerThread*)this;
2084 }
2085
2086 // Dedicated thread to sweep the code cache
2087 class CodeCacheSweeperThread : public JavaThread {
2088 CompiledMethod* _scanned_compiled_method; // nmethod being scanned by the sweeper
2089 public:
2090 CodeCacheSweeperThread();
2091 // Track the nmethod currently being scanned by the sweeper
2092 void set_scanned_compiled_method(CompiledMethod* cm) {
2093 assert(_scanned_compiled_method == NULL || cm == NULL, "should reset to NULL before writing a new value");
2094 _scanned_compiled_method = cm;
2095 }
2096
2097 // Hide sweeper thread from external view.
2098 bool is_hidden_from_external_view() const { return true; }
2099
2100 bool is_Code_cache_sweeper_thread() const { return true; }
2101
2102 // Prevent GC from unloading _scanned_compiled_method
2103 void oops_do(OopClosure* f, CodeBlobClosure* cf);
2104 void nmethods_do(CodeBlobClosure* cf);
2105 };
2106
2107 // A thread used for Compilation.
2108 class CompilerThread : public JavaThread {
2109 friend class VMStructs;
2110 private:
2111 CompilerCounters* _counters;
2112
2113 ciEnv* _env;
2114 CompileLog* _log;
2115 CompileTask* volatile _task; // print_threads_compiling can read this concurrently.
2116 CompileQueue* _queue;
2117 BufferBlob* _buffer_blob;
2118
2119 AbstractCompiler* _compiler;
2120 TimeStamp _idle_time;
2121
2122 public:
2123
2124 static CompilerThread* current();
2125
2126 CompilerThread(CompileQueue* queue, CompilerCounters* counters);
2127 ~CompilerThread();
2128
2129 bool is_Compiler_thread() const { return true; }
2130
2131 virtual bool can_call_java() const;
2132
2133 // Hide native compiler threads from external view.
2134 bool is_hidden_from_external_view() const { return !can_call_java(); }
2135
2136 void set_compiler(AbstractCompiler* c) { _compiler = c; }
2137 AbstractCompiler* compiler() const { return _compiler; }
2138
2139 CompileQueue* queue() const { return _queue; }
2140 CompilerCounters* counters() const { return _counters; }
2141
2142 // Get/set the thread's compilation environment.
2143 ciEnv* env() { return _env; }
2144 void set_env(ciEnv* env) { _env = env; }
2145
2146 BufferBlob* get_buffer_blob() const { return _buffer_blob; }
2147 void set_buffer_blob(BufferBlob* b) { _buffer_blob = b; }
2148
2149 // Get/set the thread's logging information
2150 CompileLog* log() { return _log; }
2151 void init_log(CompileLog* log) {
2152 // Set once, for good.
2153 assert(_log == NULL, "set only once");
2154 _log = log;
2155 }
2156
2157 void start_idle_timer() { _idle_time.update(); }
2158 jlong idle_time_millis() {
2159 return TimeHelper::counter_to_millis(_idle_time.ticks_since_update());
2160 }
2161
2162 #ifndef PRODUCT
2163 private:
2164 IdealGraphPrinter *_ideal_graph_printer;
2165 public:
2166 IdealGraphPrinter *ideal_graph_printer() { return _ideal_graph_printer; }
2167 void set_ideal_graph_printer(IdealGraphPrinter *n) { _ideal_graph_printer = n; }
2168 #endif
2169
2170 // Get/set the thread's current task
2171 CompileTask* task() { return _task; }
2172 void set_task(CompileTask* task) { _task = task; }
2173 };
2174
2175 inline CompilerThread* CompilerThread::current() {
2176 return JavaThread::current()->as_CompilerThread();
2177 }
2178
2179 // The active thread queue. It also keeps track of the current used
2180 // thread priorities.
2181 class Threads: AllStatic {
2182 friend class VMStructs;
2183 private:
2184 static int _number_of_threads;
2185 static int _number_of_non_daemon_threads;
2186 static int _return_code;
2187 static uintx _thread_claim_token;
2188 #ifdef ASSERT
2189 static bool _vm_complete;
2190 #endif
2191
2192 static void initialize_java_lang_classes(JavaThread* main_thread, TRAPS);
2193 static void initialize_jsr292_core_classes(TRAPS);
2194
2195 public:
2196 // Thread management
2197 // force_daemon is a concession to JNI, where we may need to add a
2198 // thread to the thread list before allocating its thread object
2199 static void add(JavaThread* p, bool force_daemon = false);
2200 static void remove(JavaThread* p, bool is_daemon);
2201 static void non_java_threads_do(ThreadClosure* tc);
2202 static void java_threads_do(ThreadClosure* tc);
2203 static void java_threads_and_vm_thread_do(ThreadClosure* tc);
2204 static void threads_do(ThreadClosure* tc);
2205 static void possibly_parallel_threads_do(bool is_par, ThreadClosure* tc);
2206
2207 // Initializes the vm and creates the vm thread
2208 static jint create_vm(JavaVMInitArgs* args, bool* canTryAgain);
2209 static void convert_vm_init_libraries_to_agents();
2210 static void create_vm_init_libraries();
2211 static void create_vm_init_agents();
2212 static void shutdown_vm_agents();
2213 static bool destroy_vm();
2214 // Supported VM versions via JNI
2215 // Includes JNI_VERSION_1_1
2216 static jboolean is_supported_jni_version_including_1_1(jint version);
2217 // Does not include JNI_VERSION_1_1
2218 static jboolean is_supported_jni_version(jint version);
2219
2220 // The "thread claim token" provides a way for threads to be claimed
2221 // by parallel worker tasks.
2222 //
2223 // Each thread contains a "token" field. A task will claim the
2224 // thread only if its token is different from the global token,
2225 // which is updated by calling change_thread_claim_token(). When
2226 // a thread is claimed, it's token is set to the global token value
2227 // so other threads in the same iteration pass won't claim it.
2228 //
2229 // For this to work change_thread_claim_token() needs to be called
2230 // exactly once in sequential code before starting parallel tasks
2231 // that should claim threads.
2232 //
2233 // New threads get their token set to 0 and change_thread_claim_token()
2234 // never sets the global token to 0.
2235 static uintx thread_claim_token() { return _thread_claim_token; }
2236 static void change_thread_claim_token();
2237 static void assert_all_threads_claimed() NOT_DEBUG_RETURN;
2238
2239 // Apply "f->do_oop" to all root oops in all threads.
2240 // This version may only be called by sequential code.
2241 static void oops_do(OopClosure* f, CodeBlobClosure* cf);
2242 // This version may be called by sequential or parallel code.
2243 static void possibly_parallel_oops_do(bool is_par, OopClosure* f, CodeBlobClosure* cf);
2244
2245 // Sweeper
2246 static void nmethods_do(CodeBlobClosure* cf);
2247
2248 // RedefineClasses support
2249 static void metadata_do(MetadataClosure* f);
2250 static void metadata_handles_do(void f(Metadata*));
2251
2252 #ifdef ASSERT
2253 static bool is_vm_complete() { return _vm_complete; }
2254 #endif // ASSERT
2255
2256 // Verification
2257 static void verify();
2258 static void print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks, bool print_extended_info);
2259 static void print(bool print_stacks, bool internal_format) {
2260 // this function is only used by debug.cpp
2261 print_on(tty, print_stacks, internal_format, false /* no concurrent lock printed */, false /* simple format */);
2262 }
2263 static void print_on_error(outputStream* st, Thread* current, char* buf, int buflen);
2264 static void print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
2265 int buflen, bool* found_current);
2266 static void print_threads_compiling(outputStream* st, char* buf, int buflen, bool short_form = false);
2267
2268 // Get Java threads that are waiting to enter a monitor.
2269 static GrowableArray<JavaThread*>* get_pending_threads(ThreadsList * t_list,
2270 int count, address monitor);
2271
2272 // Get owning Java thread from the monitor's owner field.
2273 static JavaThread *owning_thread_from_monitor_owner(ThreadsList * t_list,
2274 address owner);
2275
2276 // Number of threads on the active threads list
2277 static int number_of_threads() { return _number_of_threads; }
2278 // Number of non-daemon threads on the active threads list
2279 static int number_of_non_daemon_threads() { return _number_of_non_daemon_threads; }
2280
2281 // Deoptimizes all frames tied to marked nmethods
2282 static void deoptimized_wrt_marked_nmethods();
2283
2284 struct Test; // For private gtest access.
2285 };
2286
2287 class SignalHandlerMark: public StackObj {
2288 private:
2289 Thread* _thread;
2290 public:
2291 SignalHandlerMark(Thread* t) {
2292 _thread = t;
2293 if (_thread) _thread->enter_signal_handler();
2294 }
2295 ~SignalHandlerMark() {
2296 if (_thread) _thread->leave_signal_handler();
2297 _thread = NULL;
2298 }
2299 };
2300
2301
2302 #endif // SHARE_RUNTIME_THREAD_HPP