1 /*
2 * Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #ifndef SHARE_RUNTIME_THREAD_HPP
26 #define SHARE_RUNTIME_THREAD_HPP
27
28 #include "jni.h"
29 #include "code/compiledMethod.hpp"
30 #include "gc/shared/gcThreadLocalData.hpp"
31 #include "gc/shared/threadLocalAllocBuffer.hpp"
32 #include "memory/allocation.hpp"
33 #include "oops/oop.hpp"
34 #include "prims/jvmtiExport.hpp"
35 #include "runtime/frame.hpp"
36 #include "runtime/globals.hpp"
37 #include "runtime/handshake.hpp"
38 #include "runtime/javaFrameAnchor.hpp"
39 #include "runtime/jniHandles.hpp"
40 #include "runtime/mutexLocker.hpp"
41 #include "runtime/os.hpp"
42 #include "runtime/osThread.hpp"
43 #include "runtime/park.hpp"
44 #include "runtime/stubRoutines.hpp"
45 #include "runtime/threadHeapSampler.hpp"
46 #include "runtime/threadLocalStorage.hpp"
47 #include "runtime/threadStatisticalInfo.hpp"
48 #include "runtime/unhandledOops.hpp"
49 #include "utilities/align.hpp"
50 #include "utilities/exceptions.hpp"
51 #include "utilities/macros.hpp"
52 #ifdef ZERO
53 # include "stack_zero.hpp"
54 #endif
55 #if INCLUDE_JFR
56 #include "jfr/support/jfrThreadExtension.hpp"
57 #endif
58
59
60 class SafeThreadsListPtr;
61 class ThreadSafepointState;
62 class ThreadsList;
63 class ThreadsSMRSupport;
64
65 class JvmtiRawMonitor;
66 class JvmtiThreadState;
67 class ThreadStatistics;
68 class ConcurrentLocksDump;
69 class ParkEvent;
70 class Parker;
71 class MonitorInfo;
72
73 class ciEnv;
74 class CompileThread;
75 class CompileLog;
76 class CompileTask;
77 class CompileQueue;
78 class CompilerCounters;
79
80 class vframeArray;
81 class vframe;
82 class javaVFrame;
83
84 class DeoptResourceMark;
85 class jvmtiDeferredLocalVariableSet;
86
87 class ThreadClosure;
88 class ICRefillVerifier;
89 class IdealGraphPrinter;
90
91 class JVMCIEnv;
92 class JVMCIPrimitiveArray;
93
94 class Metadata;
95 class ResourceArea;
96
97 DEBUG_ONLY(class ResourceMark;)
98
99 class WorkerThread;
100
101 // Class hierarchy
102 // - Thread
103 // - JavaThread
104 // - various subclasses eg CompilerThread, ServiceThread
105 // - NonJavaThread
106 // - NamedThread
107 // - VMThread
108 // - ConcurrentGCThread
109 // - WorkerThread
110 // - GangWorker
111 // - WatcherThread
112 // - JfrThreadSampler
113 //
114 // All Thread subclasses must be either JavaThread or NonJavaThread.
115 // This means !t->is_Java_thread() iff t is a NonJavaThread, or t is
116 // a partially constructed/destroyed Thread.
117
118 // Thread execution sequence and actions:
119 // All threads:
120 // - thread_native_entry // per-OS native entry point
121 // - stack initialization
122 // - other OS-level initialization (signal masks etc)
123 // - handshake with creating thread (if not started suspended)
124 // - this->call_run() // common shared entry point
125 // - shared common initialization
126 // - this->pre_run() // virtual per-thread-type initialization
127 // - this->run() // virtual per-thread-type "main" logic
128 // - shared common tear-down
129 // - this->post_run() // virtual per-thread-type tear-down
130 // - // 'this' no longer referenceable
131 // - OS-level tear-down (minimal)
132 // - final logging
133 //
134 // For JavaThread:
135 // - this->run() // virtual but not normally overridden
136 // - this->thread_main_inner() // extra call level to ensure correct stack calculations
137 // - this->entry_point() // set differently for each kind of JavaThread
138
139 class Thread: public ThreadShadow {
140 friend class VMStructs;
141 friend class JVMCIVMStructs;
142 private:
143
144 #ifndef USE_LIBRARY_BASED_TLS_ONLY
145 // Current thread is maintained as a thread-local variable
146 static THREAD_LOCAL Thread* _thr_current;
147 #endif
148
149 // Thread local data area available to the GC. The internal
150 // structure and contents of this data area is GC-specific.
151 // Only GC and GC barrier code should access this data area.
152 GCThreadLocalData _gc_data;
153
154 public:
155 static ByteSize gc_data_offset() {
156 return byte_offset_of(Thread, _gc_data);
157 }
158
159 template <typename T> T* gc_data() {
160 STATIC_ASSERT(sizeof(T) <= sizeof(_gc_data));
161 return reinterpret_cast<T*>(&_gc_data);
162 }
163
164 // Exception handling
165 // (Note: _pending_exception and friends are in ThreadShadow)
166 //oop _pending_exception; // pending exception for current thread
167 // const char* _exception_file; // file information for exception (debugging only)
168 // int _exception_line; // line information for exception (debugging only)
169 protected:
170
171 DEBUG_ONLY(static Thread* _starting_thread;)
172
173 // Support for forcing alignment of thread objects for biased locking
174 void* _real_malloc_address;
175
176 // JavaThread lifecycle support:
177 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
178 friend class ScanHazardPtrGatherProtectedThreadsClosure; // for cmpxchg_threads_hazard_ptr(), get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
179 friend class ScanHazardPtrGatherThreadsListClosure; // for get_threads_hazard_ptr(), untag_hazard_ptr() access
180 friend class ScanHazardPtrPrintMatchingThreadsClosure; // for get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
181 friend class ThreadsSMRSupport; // for _nested_threads_hazard_ptr_cnt, _threads_hazard_ptr, _threads_list_ptr access
182
183 ThreadsList* volatile _threads_hazard_ptr;
184 SafeThreadsListPtr* _threads_list_ptr;
185 ThreadsList* cmpxchg_threads_hazard_ptr(ThreadsList* exchange_value, ThreadsList* compare_value);
186 ThreadsList* get_threads_hazard_ptr();
187 void set_threads_hazard_ptr(ThreadsList* new_list);
188 static bool is_hazard_ptr_tagged(ThreadsList* list) {
189 return (intptr_t(list) & intptr_t(1)) == intptr_t(1);
190 }
191 static ThreadsList* tag_hazard_ptr(ThreadsList* list) {
192 return (ThreadsList*)(intptr_t(list) | intptr_t(1));
193 }
194 static ThreadsList* untag_hazard_ptr(ThreadsList* list) {
195 return (ThreadsList*)(intptr_t(list) & ~intptr_t(1));
196 }
197 // This field is enabled via -XX:+EnableThreadSMRStatistics:
198 uint _nested_threads_hazard_ptr_cnt;
199 void dec_nested_threads_hazard_ptr_cnt() {
200 assert(_nested_threads_hazard_ptr_cnt != 0, "mismatched {dec,inc}_nested_threads_hazard_ptr_cnt()");
201 _nested_threads_hazard_ptr_cnt--;
202 }
203 void inc_nested_threads_hazard_ptr_cnt() {
204 _nested_threads_hazard_ptr_cnt++;
205 }
206 uint nested_threads_hazard_ptr_cnt() {
207 return _nested_threads_hazard_ptr_cnt;
208 }
209
210 public:
211 void* operator new(size_t size) throw() { return allocate(size, true); }
212 void* operator new(size_t size, const std::nothrow_t& nothrow_constant) throw() {
213 return allocate(size, false); }
214 void operator delete(void* p);
215
216 protected:
217 static void* allocate(size_t size, bool throw_excpt, MEMFLAGS flags = mtThread);
218 private:
219
220 // ***************************************************************
221 // Suspend and resume support
222 // ***************************************************************
223 //
224 // VM suspend/resume no longer exists - it was once used for various
225 // things including safepoints but was deprecated and finally removed
226 // in Java 7. Because VM suspension was considered "internal" Java-level
227 // suspension was considered "external", and this legacy naming scheme
228 // remains.
229 //
230 // External suspend/resume requests come from JVM_SuspendThread,
231 // JVM_ResumeThread, JVMTI SuspendThread, and finally JVMTI
232 // ResumeThread. External
233 // suspend requests cause _external_suspend to be set and external
234 // resume requests cause _external_suspend to be cleared.
235 // External suspend requests do not nest on top of other external
236 // suspend requests. The higher level APIs reject suspend requests
237 // for already suspended threads.
238 //
239 // The external_suspend
240 // flag is checked by has_special_runtime_exit_condition() and java thread
241 // will self-suspend when handle_special_runtime_exit_condition() is
242 // called. Most uses of the _thread_blocked state in JavaThreads are
243 // considered the same as being externally suspended; if the blocking
244 // condition lifts, the JavaThread will self-suspend. Other places
245 // where VM checks for external_suspend include:
246 // + mutex granting (do not enter monitors when thread is suspended)
247 // + state transitions from _thread_in_native
248 //
249 // In general, java_suspend() does not wait for an external suspend
250 // request to complete. When it returns, the only guarantee is that
251 // the _external_suspend field is true.
252 //
253 // wait_for_ext_suspend_completion() is used to wait for an external
254 // suspend request to complete. External suspend requests are usually
255 // followed by some other interface call that requires the thread to
256 // be quiescent, e.g., GetCallTrace(). By moving the "wait time" into
257 // the interface that requires quiescence, we give the JavaThread a
258 // chance to self-suspend before we need it to be quiescent. This
259 // improves overall suspend/query performance.
260 //
261 // _suspend_flags controls the behavior of java_ suspend/resume.
262 // It must be set under the protection of SR_lock. Read from the flag is
263 // OK without SR_lock as long as the value is only used as a hint.
264 // (e.g., check _external_suspend first without lock and then recheck
265 // inside SR_lock and finish the suspension)
266 //
267 // _suspend_flags is also overloaded for other "special conditions" so
268 // that a single check indicates whether any special action is needed
269 // eg. for async exceptions.
270 // -------------------------------------------------------------------
271 // Notes:
272 // 1. The suspend/resume logic no longer uses ThreadState in OSThread
273 // but we still update its value to keep other part of the system (mainly
274 // JVMTI) happy. ThreadState is legacy code (see notes in
275 // osThread.hpp).
276 //
277 // 2. It would be more natural if set_external_suspend() is private and
278 // part of java_suspend(), but that probably would affect the suspend/query
279 // performance. Need more investigation on this.
280
281 // suspend/resume lock: used for self-suspend
282 Monitor* _SR_lock;
283
284 protected:
285 enum SuspendFlags {
286 // NOTE: avoid using the sign-bit as cc generates different test code
287 // when the sign-bit is used, and sometimes incorrectly - see CR 6398077
288
289 _external_suspend = 0x20000000U, // thread is asked to self suspend
290 _ext_suspended = 0x40000000U, // thread has self-suspended
291
292 _has_async_exception = 0x00000001U, // there is a pending async exception
293 _critical_native_unlock = 0x00000002U, // Must call back to unlock JNI critical lock
294
295 _trace_flag = 0x00000004U // call tracing backend
296 };
297
298 // various suspension related flags - atomically updated
299 // overloaded for async exception checking in check_special_condition_for_native_trans.
300 volatile uint32_t _suspend_flags;
301
302 private:
303 int _num_nested_signal;
304
305 DEBUG_ONLY(bool _suspendible_thread;)
306
307 public:
308 void enter_signal_handler() { _num_nested_signal++; }
309 void leave_signal_handler() { _num_nested_signal--; }
310 bool is_inside_signal_handler() const { return _num_nested_signal > 0; }
311
312 // Determines if a heap allocation failure will be retried
313 // (e.g., by deoptimizing and re-executing in the interpreter).
314 // In this case, the failed allocation must raise
315 // Universe::out_of_memory_error_retry() and omit side effects
316 // such as JVMTI events and handling -XX:+HeapDumpOnOutOfMemoryError
317 // and -XX:OnOutOfMemoryError.
318 virtual bool in_retryable_allocation() const { return false; }
319
320 #ifdef ASSERT
321 void set_suspendible_thread() {
322 _suspendible_thread = true;
323 }
324
325 void clear_suspendible_thread() {
326 _suspendible_thread = false;
327 }
328
329 bool is_suspendible_thread() { return _suspendible_thread; }
330 #endif
331
332 private:
333 // Active_handles points to a block of handles
334 JNIHandleBlock* _active_handles;
335
336 // One-element thread local free list
337 JNIHandleBlock* _free_handle_block;
338
339 // Point to the last handle mark
340 HandleMark* _last_handle_mark;
341
342 // Claim value for parallel iteration over threads.
343 uintx _threads_do_token;
344
345 // Support for GlobalCounter
346 private:
347 volatile uintx _rcu_counter;
348 public:
349 volatile uintx* get_rcu_counter() {
350 return &_rcu_counter;
351 }
352
353 public:
354 void set_last_handle_mark(HandleMark* mark) { _last_handle_mark = mark; }
355 HandleMark* last_handle_mark() const { return _last_handle_mark; }
356 private:
357
358 #ifdef ASSERT
359 ICRefillVerifier* _missed_ic_stub_refill_verifier;
360
361 public:
362 ICRefillVerifier* missed_ic_stub_refill_verifier() {
363 return _missed_ic_stub_refill_verifier;
364 }
365
366 void set_missed_ic_stub_refill_verifier(ICRefillVerifier* verifier) {
367 _missed_ic_stub_refill_verifier = verifier;
368 }
369 #endif // ASSERT
370
371 private:
372
373 // Debug support for checking if code allows safepoints or not.
374 // Safepoints in the VM can happen because of allocation, invoking a VM operation, or blocking on
375 // mutex, or blocking on an object synchronizer (Java locking).
376 // If _no_safepoint_count is non-zero, then an assertion failure will happen in any of
377 // the above cases.
378 //
379 // The class NoSafepointVerifier is used to set this counter.
380 //
381 NOT_PRODUCT(int _no_safepoint_count;) // If 0, thread allow a safepoint to happen
382
383 private:
384 // Used by SkipGCALot class.
385 NOT_PRODUCT(bool _skip_gcalot;) // Should we elide gc-a-lot?
386
387 friend class GCLocker;
388 friend class NoSafepointVerifier;
389 friend class PauseNoSafepointVerifier;
390
391 volatile void* _polling_page; // Thread local polling page
392
393 ThreadLocalAllocBuffer _tlab; // Thread-local eden
394 jlong _allocated_bytes; // Cumulative number of bytes allocated on
395 // the Java heap
396 ThreadHeapSampler _heap_sampler; // For use when sampling the memory.
397
398 ThreadStatisticalInfo _statistical_info; // Statistics about the thread
399
400 JFR_ONLY(DEFINE_THREAD_LOCAL_FIELD_JFR;) // Thread-local data for jfr
401
402 int _vm_operation_started_count; // VM_Operation support
403 int _vm_operation_completed_count; // VM_Operation support
404
405 ObjectMonitor* _current_pending_monitor; // ObjectMonitor this thread
406 // is waiting to lock
407 bool _current_pending_monitor_is_from_java; // locking is from Java code
408 JvmtiRawMonitor* _current_pending_raw_monitor; // JvmtiRawMonitor this thread
409 // is waiting to lock
410
411
412 // ObjectMonitor on which this thread called Object.wait()
413 ObjectMonitor* _current_waiting_monitor;
414
415 // Per-thread ObjectMonitor lists:
416 public:
417 ObjectMonitor* om_free_list; // SLL of free ObjectMonitors
418 int om_free_count; // # on om_free_list
419 int om_free_provision; // # to try to allocate next
420 ObjectMonitor* om_in_use_list; // SLL of in-use ObjectMonitors
421 int om_in_use_count; // # on om_in_use_list
422
423 #ifdef ASSERT
424 private:
425 volatile uint64_t _visited_for_critical_count;
426
427 public:
428 void set_visited_for_critical_count(uint64_t safepoint_id) {
429 assert(_visited_for_critical_count == 0, "Must be reset before set");
430 assert((safepoint_id & 0x1) == 1, "Must be odd");
431 _visited_for_critical_count = safepoint_id;
432 }
433 void reset_visited_for_critical_count(uint64_t safepoint_id) {
434 assert(_visited_for_critical_count == safepoint_id, "Was not visited");
435 _visited_for_critical_count = 0;
436 }
437 bool was_visited_for_critical_count(uint64_t safepoint_id) const {
438 return _visited_for_critical_count == safepoint_id;
439 }
440 #endif
441
442 public:
443 enum {
444 is_definitely_current_thread = true
445 };
446
447 // Constructor
448 Thread();
449 virtual ~Thread() = 0; // Thread is abstract.
450
451 // Manage Thread::current()
452 void initialize_thread_current();
453 static void clear_thread_current(); // TLS cleanup needed before threads terminate
454
455 protected:
456 // To be implemented by children.
457 virtual void run() = 0;
458 virtual void pre_run() = 0;
459 virtual void post_run() = 0; // Note: Thread must not be deleted prior to calling this!
460
461 #ifdef ASSERT
462 enum RunState {
463 PRE_CALL_RUN,
464 CALL_RUN,
465 PRE_RUN,
466 RUN,
467 POST_RUN
468 // POST_CALL_RUN - can't define this one as 'this' may be deleted when we want to set it
469 };
470 RunState _run_state; // for lifecycle checks
471 #endif
472
473
474 public:
475 // invokes <ChildThreadClass>::run(), with common preparations and cleanups.
476 void call_run();
477
478 // Testers
479 virtual bool is_VM_thread() const { return false; }
480 virtual bool is_Java_thread() const { return false; }
481 virtual bool is_Compiler_thread() const { return false; }
482 virtual bool is_Code_cache_sweeper_thread() const { return false; }
483 virtual bool is_hidden_from_external_view() const { return false; }
484 virtual bool is_jvmti_agent_thread() const { return false; }
485 // True iff the thread can perform GC operations at a safepoint.
486 // Generally will be true only of VM thread and parallel GC WorkGang
487 // threads.
488 virtual bool is_GC_task_thread() const { return false; }
489 virtual bool is_Watcher_thread() const { return false; }
490 virtual bool is_ConcurrentGC_thread() const { return false; }
491 virtual bool is_Named_thread() const { return false; }
492 virtual bool is_Worker_thread() const { return false; }
493
494 // Can this thread make Java upcalls
495 virtual bool can_call_java() const { return false; }
496
497 // Is this a JavaThread that is on the VM's current ThreadsList?
498 // If so it must participate in the safepoint protocol.
499 virtual bool is_active_Java_thread() const { return false; }
500
501 // Casts
502 virtual WorkerThread* as_Worker_thread() const { return NULL; }
503
504 virtual char* name() const { return (char*)"Unknown thread"; }
505
506 // Returns the current thread (ASSERTS if NULL)
507 static inline Thread* current();
508 // Returns the current thread, or NULL if not attached
509 static inline Thread* current_or_null();
510 // Returns the current thread, or NULL if not attached, and is
511 // safe for use from signal-handlers
512 static inline Thread* current_or_null_safe();
513
514 // Common thread operations
515 #ifdef ASSERT
516 static void check_for_dangling_thread_pointer(Thread *thread);
517 #endif
518 static void set_priority(Thread* thread, ThreadPriority priority);
519 static ThreadPriority get_priority(const Thread* const thread);
520 static void start(Thread* thread);
521
522 void set_native_thread_name(const char *name) {
523 assert(Thread::current() == this, "set_native_thread_name can only be called on the current thread");
524 os::set_native_thread_name(name);
525 }
526
527 ObjectMonitor** om_in_use_list_addr() { return (ObjectMonitor **)&om_in_use_list; }
528 Monitor* SR_lock() const { return _SR_lock; }
529
530 bool has_async_exception() const { return (_suspend_flags & _has_async_exception) != 0; }
531
532 inline void set_suspend_flag(SuspendFlags f);
533 inline void clear_suspend_flag(SuspendFlags f);
534
535 inline void set_has_async_exception();
536 inline void clear_has_async_exception();
537
538 bool do_critical_native_unlock() const { return (_suspend_flags & _critical_native_unlock) != 0; }
539
540 inline void set_critical_native_unlock();
541 inline void clear_critical_native_unlock();
542
543 inline void set_trace_flag();
544 inline void clear_trace_flag();
545
546 // Support for Unhandled Oop detection
547 // Add the field for both, fastdebug and debug, builds to keep
548 // Thread's fields layout the same.
549 // Note: CHECK_UNHANDLED_OOPS is defined only for fastdebug build.
550 #ifdef CHECK_UNHANDLED_OOPS
551 private:
552 UnhandledOops* _unhandled_oops;
553 #elif defined(ASSERT)
554 private:
555 void* _unhandled_oops;
556 #endif
557 #ifdef CHECK_UNHANDLED_OOPS
558 public:
559 UnhandledOops* unhandled_oops() { return _unhandled_oops; }
560 // Mark oop safe for gc. It may be stack allocated but won't move.
561 void allow_unhandled_oop(oop *op) {
562 if (CheckUnhandledOops) unhandled_oops()->allow_unhandled_oop(op);
563 }
564 // Clear oops at safepoint so crashes point to unhandled oop violator
565 void clear_unhandled_oops() {
566 if (CheckUnhandledOops) unhandled_oops()->clear_unhandled_oops();
567 }
568 #endif // CHECK_UNHANDLED_OOPS
569
570 public:
571 #ifndef PRODUCT
572 bool skip_gcalot() { return _skip_gcalot; }
573 void set_skip_gcalot(bool v) { _skip_gcalot = v; }
574 #endif
575
576 // Installs a pending exception to be inserted later
577 static void send_async_exception(oop thread_oop, oop java_throwable);
578
579 // Resource area
580 ResourceArea* resource_area() const { return _resource_area; }
581 void set_resource_area(ResourceArea* area) { _resource_area = area; }
582
583 OSThread* osthread() const { return _osthread; }
584 void set_osthread(OSThread* thread) { _osthread = thread; }
585
586 // JNI handle support
587 JNIHandleBlock* active_handles() const { return _active_handles; }
588 void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
589 JNIHandleBlock* free_handle_block() const { return _free_handle_block; }
590 void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
591
592 // Internal handle support
593 HandleArea* handle_area() const { return _handle_area; }
594 void set_handle_area(HandleArea* area) { _handle_area = area; }
595
596 GrowableArray<Metadata*>* metadata_handles() const { return _metadata_handles; }
597 void set_metadata_handles(GrowableArray<Metadata*>* handles){ _metadata_handles = handles; }
598
599 // Thread-Local Allocation Buffer (TLAB) support
600 ThreadLocalAllocBuffer& tlab() { return _tlab; }
601 void initialize_tlab() {
602 if (UseTLAB) {
603 tlab().initialize();
604 }
605 }
606
607 jlong allocated_bytes() { return _allocated_bytes; }
608 void set_allocated_bytes(jlong value) { _allocated_bytes = value; }
609 void incr_allocated_bytes(jlong size) { _allocated_bytes += size; }
610 inline jlong cooked_allocated_bytes();
611
612 ThreadHeapSampler& heap_sampler() { return _heap_sampler; }
613
614 ThreadStatisticalInfo& statistical_info() { return _statistical_info; }
615
616 JFR_ONLY(DEFINE_THREAD_LOCAL_ACCESSOR_JFR;)
617
618 bool is_trace_suspend() { return (_suspend_flags & _trace_flag) != 0; }
619
620 // VM operation support
621 int vm_operation_ticket() { return ++_vm_operation_started_count; }
622 int vm_operation_completed_count() { return _vm_operation_completed_count; }
623 void increment_vm_operation_completed_count() { _vm_operation_completed_count++; }
624
625 // For tracking the heavyweight monitor the thread is pending on.
626 ObjectMonitor* current_pending_monitor() {
627 return _current_pending_monitor;
628 }
629 void set_current_pending_monitor(ObjectMonitor* monitor) {
630 _current_pending_monitor = monitor;
631 }
632 void set_current_pending_monitor_is_from_java(bool from_java) {
633 _current_pending_monitor_is_from_java = from_java;
634 }
635 bool current_pending_monitor_is_from_java() {
636 return _current_pending_monitor_is_from_java;
637 }
638
639 // For tracking the ObjectMonitor on which this thread called Object.wait()
640 ObjectMonitor* current_waiting_monitor() {
641 return _current_waiting_monitor;
642 }
643 void set_current_waiting_monitor(ObjectMonitor* monitor) {
644 _current_waiting_monitor = monitor;
645 }
646
647 // For tracking the Jvmti raw monitor the thread is pending on.
648 JvmtiRawMonitor* current_pending_raw_monitor() {
649 return _current_pending_raw_monitor;
650 }
651 void set_current_pending_raw_monitor(JvmtiRawMonitor* monitor) {
652 _current_pending_raw_monitor = monitor;
653 }
654
655 // GC support
656 // Apply "f->do_oop" to all root oops in "this".
657 // Used by JavaThread::oops_do.
658 // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames
659 virtual void oops_do(OopClosure* f, CodeBlobClosure* cf);
660
661 // Handles the parallel case for claim_threads_do.
662 private:
663 bool claim_par_threads_do(uintx claim_token);
664 public:
665 // Requires that "claim_token" is that of the current iteration.
666 // If "is_par" is false, sets the token of "this" to
667 // "claim_token", and returns "true". If "is_par" is true,
668 // uses an atomic instruction to set the current thread's token to
669 // "claim_token", if it is not already. Returns "true" iff the
670 // calling thread does the update, this indicates that the calling thread
671 // has claimed the thread in the current iteration.
672 bool claim_threads_do(bool is_par, uintx claim_token) {
673 if (!is_par) {
674 _threads_do_token = claim_token;
675 return true;
676 } else {
677 return claim_par_threads_do(claim_token);
678 }
679 }
680
681 uintx threads_do_token() const { return _threads_do_token; }
682
683 // jvmtiRedefineClasses support
684 void metadata_handles_do(void f(Metadata*));
685
686 // Used by fast lock support
687 virtual bool is_lock_owned(address adr) const;
688
689 // Check if address is in the stack of the thread (not just for locks).
690 // Warning: the method can only be used on the running thread
691 bool is_in_stack(address adr) const;
692 // Check if address is in the usable part of the stack (excludes protected
693 // guard pages)
694 bool is_in_usable_stack(address adr) const;
695
696 // Sets this thread as starting thread. Returns failure if thread
697 // creation fails due to lack of memory, too many threads etc.
698 bool set_as_starting_thread();
699
700 protected:
701 // OS data associated with the thread
702 OSThread* _osthread; // Platform-specific thread information
703
704 // Thread local resource area for temporary allocation within the VM
705 ResourceArea* _resource_area;
706
707 DEBUG_ONLY(ResourceMark* _current_resource_mark;)
708
709 // Thread local handle area for allocation of handles within the VM
710 HandleArea* _handle_area;
711 GrowableArray<Metadata*>* _metadata_handles;
712
713 // Support for stack overflow handling, get_thread, etc.
714 address _stack_base;
715 size_t _stack_size;
716 int _lgrp_id;
717
718 volatile void** polling_page_addr() { return &_polling_page; }
719
720 public:
721 // Stack overflow support
722 address stack_base() const { assert(_stack_base != NULL,"Sanity check"); return _stack_base; }
723 void set_stack_base(address base) { _stack_base = base; }
724 size_t stack_size() const { return _stack_size; }
725 void set_stack_size(size_t size) { _stack_size = size; }
726 address stack_end() const { return stack_base() - stack_size(); }
727 void record_stack_base_and_size();
728 void register_thread_stack_with_NMT() NOT_NMT_RETURN;
729
730 bool on_local_stack(address adr) const {
731 // QQQ this has knowledge of direction, ought to be a stack method
732 return (_stack_base > adr && adr >= stack_end());
733 }
734
735 int lgrp_id() const { return _lgrp_id; }
736 void set_lgrp_id(int value) { _lgrp_id = value; }
737
738 // Printing
739 void print_on(outputStream* st, bool print_extended_info) const;
740 virtual void print_on(outputStream* st) const { print_on(st, false); }
741 void print() const;
742 virtual void print_on_error(outputStream* st, char* buf, int buflen) const;
743 void print_value_on(outputStream* st) const;
744
745 // Debug-only code
746 #ifdef ASSERT
747 private:
748 // Deadlock detection support for Mutex locks. List of locks own by thread.
749 Mutex* _owned_locks;
750 // Mutex::set_owner_implementation is the only place where _owned_locks is modified,
751 // thus the friendship
752 friend class Mutex;
753 friend class Monitor;
754
755 public:
756 void print_owned_locks_on(outputStream* st) const;
757 void print_owned_locks() const { print_owned_locks_on(tty); }
758 Mutex* owned_locks() const { return _owned_locks; }
759 bool owns_locks() const { return owned_locks() != NULL; }
760
761 // Deadlock detection
762 ResourceMark* current_resource_mark() { return _current_resource_mark; }
763 void set_current_resource_mark(ResourceMark* rm) { _current_resource_mark = rm; }
764 #endif // ASSERT
765
766 // These functions check conditions on a JavaThread before possibly going to a safepoint,
767 // including NoSafepointVerifier.
768 void check_for_valid_safepoint_state() NOT_DEBUG_RETURN;
769 void check_possible_safepoint() NOT_DEBUG_RETURN;
770
771 private:
772 volatile int _jvmti_env_iteration_count;
773
774 public:
775 void entering_jvmti_env_iteration() { ++_jvmti_env_iteration_count; }
776 void leaving_jvmti_env_iteration() { --_jvmti_env_iteration_count; }
777 bool is_inside_jvmti_env_iteration() { return _jvmti_env_iteration_count > 0; }
778
779 // Code generation
780 static ByteSize exception_file_offset() { return byte_offset_of(Thread, _exception_file); }
781 static ByteSize exception_line_offset() { return byte_offset_of(Thread, _exception_line); }
782 static ByteSize active_handles_offset() { return byte_offset_of(Thread, _active_handles); }
783
784 static ByteSize stack_base_offset() { return byte_offset_of(Thread, _stack_base); }
785 static ByteSize stack_size_offset() { return byte_offset_of(Thread, _stack_size); }
786
787 static ByteSize polling_page_offset() { return byte_offset_of(Thread, _polling_page); }
788
789 static ByteSize tlab_start_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::start_offset(); }
790 static ByteSize tlab_end_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::end_offset(); }
791 static ByteSize tlab_top_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::top_offset(); }
792 static ByteSize tlab_pf_top_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::pf_top_offset(); }
793
794 static ByteSize allocated_bytes_offset() { return byte_offset_of(Thread, _allocated_bytes); }
795
796 JFR_ONLY(DEFINE_THREAD_LOCAL_OFFSET_JFR;)
797
798 public:
799 volatile intptr_t _Stalled;
800 volatile int _TypeTag;
801 ParkEvent * _ParkEvent; // for Object monitors and JVMTI raw monitors
802 ParkEvent * _MuxEvent; // for low-level muxAcquire-muxRelease
803 int NativeSyncRecursion; // diagnostic
804
805 volatile int _OnTrap; // Resume-at IP delta
806 jint _hashStateW; // Marsaglia Shift-XOR thread-local RNG
807 jint _hashStateX; // thread-specific hashCode generator state
808 jint _hashStateY;
809 jint _hashStateZ;
810
811 // Low-level leaf-lock primitives used to implement synchronization
812 // and native monitor-mutex infrastructure.
813 // Not for general synchronization use.
814 static void SpinAcquire(volatile int * Lock, const char * Name);
815 static void SpinRelease(volatile int * Lock);
816 static void muxAcquire(volatile intptr_t * Lock, const char * Name);
817 static void muxRelease(volatile intptr_t * Lock);
818 };
819
820 // Inline implementation of Thread::current()
821 inline Thread* Thread::current() {
822 Thread* current = current_or_null();
823 assert(current != NULL, "Thread::current() called on detached thread");
824 return current;
825 }
826
827 inline Thread* Thread::current_or_null() {
828 #ifndef USE_LIBRARY_BASED_TLS_ONLY
829 return _thr_current;
830 #else
831 if (ThreadLocalStorage::is_initialized()) {
832 return ThreadLocalStorage::thread();
833 }
834 return NULL;
835 #endif
836 }
837
838 inline Thread* Thread::current_or_null_safe() {
839 if (ThreadLocalStorage::is_initialized()) {
840 return ThreadLocalStorage::thread();
841 }
842 return NULL;
843 }
844
845 class NonJavaThread: public Thread {
846 friend class VMStructs;
847
848 NonJavaThread* volatile _next;
849
850 class List;
851 static List _the_list;
852
853 void add_to_the_list();
854 void remove_from_the_list();
855
856 protected:
857 virtual void pre_run();
858 virtual void post_run();
859
860 public:
861 NonJavaThread();
862 ~NonJavaThread();
863
864 class Iterator;
865 };
866
867 // Provides iteration over the list of NonJavaThreads.
868 // List addition occurs in pre_run(), and removal occurs in post_run(),
869 // so that only live fully-initialized threads can be found in the list.
870 // Threads created after an iterator is constructed will not be visited
871 // by the iterator. The scope of an iterator is a critical section; there
872 // must be no safepoint checks in that scope.
873 class NonJavaThread::Iterator : public StackObj {
874 uint _protect_enter;
875 NonJavaThread* _current;
876
877 // Noncopyable.
878 Iterator(const Iterator&);
879 Iterator& operator=(const Iterator&);
880
881 public:
882 Iterator();
883 ~Iterator();
884
885 bool end() const { return _current == NULL; }
886 NonJavaThread* current() const { return _current; }
887 void step();
888 };
889
890 // Name support for threads. non-JavaThread subclasses with multiple
891 // uniquely named instances should derive from this.
892 class NamedThread: public NonJavaThread {
893 friend class VMStructs;
894 enum {
895 max_name_len = 64
896 };
897 private:
898 char* _name;
899 // log JavaThread being processed by oops_do
900 JavaThread* _processed_thread;
901 uint _gc_id; // The current GC id when a thread takes part in GC
902
903 public:
904 NamedThread();
905 ~NamedThread();
906 // May only be called once per thread.
907 void set_name(const char* format, ...) ATTRIBUTE_PRINTF(2, 3);
908 virtual bool is_Named_thread() const { return true; }
909 virtual char* name() const { return _name == NULL ? (char*)"Unknown Thread" : _name; }
910 JavaThread *processed_thread() { return _processed_thread; }
911 void set_processed_thread(JavaThread *thread) { _processed_thread = thread; }
912 virtual void print_on(outputStream* st) const;
913
914 void set_gc_id(uint gc_id) { _gc_id = gc_id; }
915 uint gc_id() { return _gc_id; }
916 };
917
918 // Worker threads are named and have an id of an assigned work.
919 class WorkerThread: public NamedThread {
920 private:
921 uint _id;
922 public:
923 WorkerThread() : _id(0) { }
924 virtual bool is_Worker_thread() const { return true; }
925
926 virtual WorkerThread* as_Worker_thread() const {
927 assert(is_Worker_thread(), "Dubious cast to WorkerThread*?");
928 return (WorkerThread*) this;
929 }
930
931 void set_id(uint work_id) { _id = work_id; }
932 uint id() const { return _id; }
933 };
934
935 // A single WatcherThread is used for simulating timer interrupts.
936 class WatcherThread: public NonJavaThread {
937 friend class VMStructs;
938 protected:
939 virtual void run();
940
941 private:
942 static WatcherThread* _watcher_thread;
943
944 static bool _startable;
945 // volatile due to at least one lock-free read
946 volatile static bool _should_terminate;
947 public:
948 enum SomeConstants {
949 delay_interval = 10 // interrupt delay in milliseconds
950 };
951
952 // Constructor
953 WatcherThread();
954
955 // No destruction allowed
956 ~WatcherThread() {
957 guarantee(false, "WatcherThread deletion must fix the race with VM termination");
958 }
959
960 // Tester
961 bool is_Watcher_thread() const { return true; }
962
963 // Printing
964 char* name() const { return (char*)"VM Periodic Task Thread"; }
965 void print_on(outputStream* st) const;
966 void unpark();
967
968 // Returns the single instance of WatcherThread
969 static WatcherThread* watcher_thread() { return _watcher_thread; }
970
971 // Create and start the single instance of WatcherThread, or stop it on shutdown
972 static void start();
973 static void stop();
974 // Only allow start once the VM is sufficiently initialized
975 // Otherwise the first task to enroll will trigger the start
976 static void make_startable();
977 private:
978 int sleep() const;
979 };
980
981
982 class CompilerThread;
983
984 typedef void (*ThreadFunction)(JavaThread*, TRAPS);
985
986 class JavaThread: public Thread {
987 friend class VMStructs;
988 friend class JVMCIVMStructs;
989 friend class WhiteBox;
990 private:
991 bool _on_thread_list; // Is set when this JavaThread is added to the Threads list
992 oop _threadObj; // The Java level thread object
993
994 #ifdef ASSERT
995 private:
996 int _java_call_counter;
997
998 public:
999 int java_call_counter() { return _java_call_counter; }
1000 void inc_java_call_counter() { _java_call_counter++; }
1001 void dec_java_call_counter() {
1002 assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
1003 _java_call_counter--;
1004 }
1005 private: // restore original namespace restriction
1006 #endif // ifdef ASSERT
1007
1008 #ifndef PRODUCT
1009 public:
1010 enum {
1011 jump_ring_buffer_size = 16
1012 };
1013 private: // restore original namespace restriction
1014 #endif
1015
1016 JavaFrameAnchor _anchor; // Encapsulation of current java frame and it state
1017
1018 ThreadFunction _entry_point;
1019
1020 JNIEnv _jni_environment;
1021
1022 // Deopt support
1023 DeoptResourceMark* _deopt_mark; // Holds special ResourceMark for deoptimization
1024
1025 CompiledMethod* _deopt_nmethod; // CompiledMethod that is currently being deoptimized
1026 vframeArray* _vframe_array_head; // Holds the heap of the active vframeArrays
1027 vframeArray* _vframe_array_last; // Holds last vFrameArray we popped
1028 // Because deoptimization is lazy we must save jvmti requests to set locals
1029 // in compiled frames until we deoptimize and we have an interpreter frame.
1030 // This holds the pointer to array (yeah like there might be more than one) of
1031 // description of compiled vframes that have locals that need to be updated.
1032 GrowableArray<jvmtiDeferredLocalVariableSet*>* _deferred_locals_updates;
1033
1034 // Handshake value for fixing 6243940. We need a place for the i2c
1035 // adapter to store the callee Method*. This value is NEVER live
1036 // across a gc point so it does NOT have to be gc'd
1037 // The handshake is open ended since we can't be certain that it will
1038 // be NULLed. This is because we rarely ever see the race and end up
1039 // in handle_wrong_method which is the backend of the handshake. See
1040 // code in i2c adapters and handle_wrong_method.
1041
1042 Method* _callee_target;
1043
1044 // Used to pass back results to the interpreter or generated code running Java code.
1045 oop _vm_result; // oop result is GC-preserved
1046 Metadata* _vm_result_2; // non-oop result
1047
1048 // See ReduceInitialCardMarks: this holds the precise space interval of
1049 // the most recent slow path allocation for which compiled code has
1050 // elided card-marks for performance along the fast-path.
1051 MemRegion _deferred_card_mark;
1052
1053 MonitorChunk* _monitor_chunks; // Contains the off stack monitors
1054 // allocated during deoptimization
1055 // and by JNI_MonitorEnter/Exit
1056
1057 // Async. requests support
1058 enum AsyncRequests {
1059 _no_async_condition = 0,
1060 _async_exception,
1061 _async_unsafe_access_error
1062 };
1063 AsyncRequests _special_runtime_exit_condition; // Enum indicating pending async. request
1064 oop _pending_async_exception;
1065
1066 // Safepoint support
1067 public: // Expose _thread_state for SafeFetchInt()
1068 volatile JavaThreadState _thread_state;
1069 private:
1070 ThreadSafepointState* _safepoint_state; // Holds information about a thread during a safepoint
1071 address _saved_exception_pc; // Saved pc of instruction where last implicit exception happened
1072
1073 // JavaThread termination support
1074 enum TerminatedTypes {
1075 _not_terminated = 0xDEAD - 2,
1076 _thread_exiting, // JavaThread::exit() has been called for this thread
1077 _thread_terminated, // JavaThread is removed from thread list
1078 _vm_exited // JavaThread is still executing native code, but VM is terminated
1079 // only VM_Exit can set _vm_exited
1080 };
1081
1082 // In general a JavaThread's _terminated field transitions as follows:
1083 //
1084 // _not_terminated => _thread_exiting => _thread_terminated
1085 //
1086 // _vm_exited is a special value to cover the case of a JavaThread
1087 // executing native code after the VM itself is terminated.
1088 volatile TerminatedTypes _terminated;
1089 // suspend/resume support
1090 volatile bool _suspend_equivalent; // Suspend equivalent condition
1091 jint _in_deopt_handler; // count of deoptimization
1092 // handlers thread is in
1093 volatile bool _doing_unsafe_access; // Thread may fault due to unsafe access
1094 bool _do_not_unlock_if_synchronized; // Do not unlock the receiver of a synchronized method (since it was
1095 // never locked) when throwing an exception. Used by interpreter only.
1096
1097 // JNI attach states:
1098 enum JNIAttachStates {
1099 _not_attaching_via_jni = 1, // thread is not attaching via JNI
1100 _attaching_via_jni, // thread is attaching via JNI
1101 _attached_via_jni // thread has attached via JNI
1102 };
1103
1104 // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
1105 // A native thread that is attaching via JNI starts with a value
1106 // of _attaching_via_jni and transitions to _attached_via_jni.
1107 volatile JNIAttachStates _jni_attach_state;
1108
1109 public:
1110 // State of the stack guard pages for this thread.
1111 enum StackGuardState {
1112 stack_guard_unused, // not needed
1113 stack_guard_reserved_disabled,
1114 stack_guard_yellow_reserved_disabled,// disabled (temporarily) after stack overflow
1115 stack_guard_enabled // enabled
1116 };
1117
1118 private:
1119
1120 #if INCLUDE_JVMCI
1121 // The _pending_* fields below are used to communicate extra information
1122 // from an uncommon trap in JVMCI compiled code to the uncommon trap handler.
1123
1124 // Communicates the DeoptReason and DeoptAction of the uncommon trap
1125 int _pending_deoptimization;
1126
1127 // Specifies whether the uncommon trap is to bci 0 of a synchronized method
1128 // before the monitor has been acquired.
1129 bool _pending_monitorenter;
1130
1131 // Specifies if the DeoptReason for the last uncommon trap was Reason_transfer_to_interpreter
1132 bool _pending_transfer_to_interpreter;
1133
1134 // True if in a runtime call from compiled code that will deoptimize
1135 // and re-execute a failed heap allocation in the interpreter.
1136 bool _in_retryable_allocation;
1137
1138 // An id of a speculation that JVMCI compiled code can use to further describe and
1139 // uniquely identify the speculative optimization guarded by the uncommon trap
1140 jlong _pending_failed_speculation;
1141
1142 // These fields are mutually exclusive in terms of live ranges.
1143 union {
1144 // Communicates the pc at which the most recent implicit exception occurred
1145 // from the signal handler to a deoptimization stub.
1146 address _implicit_exception_pc;
1147
1148 // Communicates an alternative call target to an i2c stub from a JavaCall .
1149 address _alternate_call_target;
1150 } _jvmci;
1151
1152 // Support for high precision, thread sensitive counters in JVMCI compiled code.
1153 jlong* _jvmci_counters;
1154
1155 public:
1156 static jlong* _jvmci_old_thread_counters;
1157 static void collect_counters(jlong* array, int length);
1158 void resize_counters(int current_size, int new_size);
1159 static void resize_all_jvmci_counters(int new_size);
1160
1161 private:
1162 #endif // INCLUDE_JVMCI
1163
1164 StackGuardState _stack_guard_state;
1165
1166 // Precompute the limit of the stack as used in stack overflow checks.
1167 // We load it from here to simplify the stack overflow check in assembly.
1168 address _stack_overflow_limit;
1169 address _reserved_stack_activation;
1170
1171 // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
1172 // used to temp. parsing values into and out of the runtime system during exception handling for compiled
1173 // code)
1174 volatile oop _exception_oop; // Exception thrown in compiled code
1175 volatile address _exception_pc; // PC where exception happened
1176 volatile address _exception_handler_pc; // PC for handler of exception
1177 volatile int _is_method_handle_return; // true (== 1) if the current exception PC is a MethodHandle call site.
1178
1179 private:
1180 // support for JNI critical regions
1181 jint _jni_active_critical; // count of entries into JNI critical region
1182
1183 // Checked JNI: function name requires exception check
1184 char* _pending_jni_exception_check_fn;
1185
1186 // For deadlock detection.
1187 int _depth_first_number;
1188
1189 // JVMTI PopFrame support
1190 // This is set to popframe_pending to signal that top Java frame should be popped immediately
1191 int _popframe_condition;
1192
1193 // If reallocation of scalar replaced objects fails, we throw OOM
1194 // and during exception propagation, pop the top
1195 // _frames_to_pop_failed_realloc frames, the ones that reference
1196 // failed reallocations.
1197 int _frames_to_pop_failed_realloc;
1198
1199 friend class VMThread;
1200 friend class ThreadWaitTransition;
1201 friend class VM_Exit;
1202
1203 void initialize(); // Initialized the instance variables
1204
1205 public:
1206 // Constructor
1207 JavaThread(bool is_attaching_via_jni = false); // for main thread and JNI attached threads
1208 JavaThread(ThreadFunction entry_point, size_t stack_size = 0);
1209 ~JavaThread();
1210
1211 #ifdef ASSERT
1212 // verify this JavaThread hasn't be published in the Threads::list yet
1213 void verify_not_published();
1214 #endif // ASSERT
1215
1216 //JNI functiontable getter/setter for JVMTI jni function table interception API.
1217 void set_jni_functions(struct JNINativeInterface_* functionTable) {
1218 _jni_environment.functions = functionTable;
1219 }
1220 struct JNINativeInterface_* get_jni_functions() {
1221 return (struct JNINativeInterface_ *)_jni_environment.functions;
1222 }
1223
1224 // This function is called at thread creation to allow
1225 // platform specific thread variables to be initialized.
1226 void cache_global_variables();
1227
1228 // Executes Shutdown.shutdown()
1229 void invoke_shutdown_hooks();
1230
1231 // Cleanup on thread exit
1232 enum ExitType {
1233 normal_exit,
1234 jni_detach
1235 };
1236 void exit(bool destroy_vm, ExitType exit_type = normal_exit);
1237
1238 void cleanup_failed_attach_current_thread(bool is_daemon);
1239
1240 // Testers
1241 virtual bool is_Java_thread() const { return true; }
1242 virtual bool can_call_java() const { return true; }
1243
1244 virtual bool is_active_Java_thread() const {
1245 return on_thread_list() && !is_terminated();
1246 }
1247
1248 // Thread oop. threadObj() can be NULL for initial JavaThread
1249 // (or for threads attached via JNI)
1250 oop threadObj() const { return _threadObj; }
1251 void set_threadObj(oop p) { _threadObj = p; }
1252
1253 // Prepare thread and add to priority queue. If a priority is
1254 // not specified, use the priority of the thread object. Threads_lock
1255 // must be held while this function is called.
1256 void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
1257
1258 void set_saved_exception_pc(address pc) { _saved_exception_pc = pc; }
1259 address saved_exception_pc() { return _saved_exception_pc; }
1260
1261
1262 ThreadFunction entry_point() const { return _entry_point; }
1263
1264 // Allocates a new Java level thread object for this thread. thread_name may be NULL.
1265 void allocate_threadObj(Handle thread_group, const char* thread_name, bool daemon, TRAPS);
1266
1267 // Last frame anchor routines
1268
1269 JavaFrameAnchor* frame_anchor(void) { return &_anchor; }
1270
1271 // last_Java_sp
1272 bool has_last_Java_frame() const { return _anchor.has_last_Java_frame(); }
1273 intptr_t* last_Java_sp() const { return _anchor.last_Java_sp(); }
1274
1275 // last_Java_pc
1276
1277 address last_Java_pc(void) { return _anchor.last_Java_pc(); }
1278
1279 // Safepoint support
1280 inline JavaThreadState thread_state() const;
1281 inline void set_thread_state(JavaThreadState s);
1282 inline void set_thread_state_fence(JavaThreadState s); // fence after setting thread state
1283 inline ThreadSafepointState* safepoint_state() const;
1284 inline void set_safepoint_state(ThreadSafepointState* state);
1285 inline bool is_at_poll_safepoint();
1286
1287 // JavaThread termination and lifecycle support:
1288 void smr_delete();
1289 bool on_thread_list() const { return _on_thread_list; }
1290 void set_on_thread_list() { _on_thread_list = true; }
1291
1292 // thread has called JavaThread::exit() or is terminated
1293 bool is_exiting() const;
1294 // thread is terminated (no longer on the threads list); we compare
1295 // against the two non-terminated values so that a freed JavaThread
1296 // will also be considered terminated.
1297 bool check_is_terminated(TerminatedTypes l_terminated) const {
1298 return l_terminated != _not_terminated && l_terminated != _thread_exiting;
1299 }
1300 bool is_terminated() const;
1301 void set_terminated(TerminatedTypes t);
1302 // special for Threads::remove() which is static:
1303 void set_terminated_value();
1304 void block_if_vm_exited();
1305
1306 bool doing_unsafe_access() { return _doing_unsafe_access; }
1307 void set_doing_unsafe_access(bool val) { _doing_unsafe_access = val; }
1308
1309 bool do_not_unlock_if_synchronized() { return _do_not_unlock_if_synchronized; }
1310 void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
1311
1312 inline void set_polling_page_release(void* poll_value);
1313 inline void set_polling_page(void* poll_value);
1314 inline volatile void* get_polling_page();
1315
1316 private:
1317 // Support for thread handshake operations
1318 HandshakeState _handshake;
1319 public:
1320 void set_handshake_operation(HandshakeOperation* op) {
1321 _handshake.set_operation(this, op);
1322 }
1323
1324 bool has_handshake() const {
1325 return _handshake.has_operation();
1326 }
1327
1328 void handshake_process_by_self() {
1329 _handshake.process_by_self(this);
1330 }
1331
1332 void handshake_process_by_vmthread() {
1333 _handshake.process_by_vmthread(this);
1334 }
1335
1336 // Suspend/resume support for JavaThread
1337 private:
1338 inline void set_ext_suspended();
1339 inline void clear_ext_suspended();
1340
1341 public:
1342 void java_suspend(); // higher-level suspension logic called by the public APIs
1343 void java_resume(); // higher-level resume logic called by the public APIs
1344 int java_suspend_self(); // low-level self-suspension mechanics
1345
1346 private:
1347 // mid-level wrapper around java_suspend_self to set up correct state and
1348 // check for a pending safepoint at the end
1349 void java_suspend_self_with_safepoint_check();
1350
1351 public:
1352 void check_and_wait_while_suspended() {
1353 assert(JavaThread::current() == this, "sanity check");
1354
1355 bool do_self_suspend;
1356 do {
1357 // were we externally suspended while we were waiting?
1358 do_self_suspend = handle_special_suspend_equivalent_condition();
1359 if (do_self_suspend) {
1360 // don't surprise the thread that suspended us by returning
1361 java_suspend_self();
1362 set_suspend_equivalent();
1363 }
1364 } while (do_self_suspend);
1365 }
1366 static void check_safepoint_and_suspend_for_native_trans(JavaThread *thread);
1367 // Check for async exception in addition to safepoint and suspend request.
1368 static void check_special_condition_for_native_trans(JavaThread *thread);
1369
1370 // Same as check_special_condition_for_native_trans but finishes the
1371 // transition into thread_in_Java mode so that it can potentially
1372 // block.
1373 static void check_special_condition_for_native_trans_and_transition(JavaThread *thread);
1374
1375 bool is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits);
1376 bool is_ext_suspend_completed_with_lock(uint32_t *bits) {
1377 MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1378 // Warning: is_ext_suspend_completed() may temporarily drop the
1379 // SR_lock to allow the thread to reach a stable thread state if
1380 // it is currently in a transient thread state.
1381 return is_ext_suspend_completed(false /* !called_by_wait */,
1382 SuspendRetryDelay, bits);
1383 }
1384
1385 // We cannot allow wait_for_ext_suspend_completion() to run forever or
1386 // we could hang. SuspendRetryCount and SuspendRetryDelay are normally
1387 // passed as the count and delay parameters. Experiments with specific
1388 // calls to wait_for_ext_suspend_completion() can be done by passing
1389 // other values in the code. Experiments with all calls can be done
1390 // via the appropriate -XX options.
1391 bool wait_for_ext_suspend_completion(int count, int delay, uint32_t *bits);
1392
1393 // test for suspend - most (all?) of these should go away
1394 bool is_thread_fully_suspended(bool wait_for_suspend, uint32_t *bits);
1395
1396 inline void set_external_suspend();
1397 inline void clear_external_suspend();
1398
1399 bool is_external_suspend() const {
1400 return (_suspend_flags & _external_suspend) != 0;
1401 }
1402 // Whenever a thread transitions from native to vm/java it must suspend
1403 // if external|deopt suspend is present.
1404 bool is_suspend_after_native() const {
1405 return (_suspend_flags & (_external_suspend JFR_ONLY(| _trace_flag))) != 0;
1406 }
1407
1408 // external suspend request is completed
1409 bool is_ext_suspended() const {
1410 return (_suspend_flags & _ext_suspended) != 0;
1411 }
1412
1413 bool is_external_suspend_with_lock() const {
1414 MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1415 return is_external_suspend();
1416 }
1417
1418 // Special method to handle a pending external suspend request
1419 // when a suspend equivalent condition lifts.
1420 bool handle_special_suspend_equivalent_condition() {
1421 assert(is_suspend_equivalent(),
1422 "should only be called in a suspend equivalence condition");
1423 MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1424 bool ret = is_external_suspend();
1425 if (!ret) {
1426 // not about to self-suspend so clear suspend equivalence
1427 clear_suspend_equivalent();
1428 }
1429 // implied else:
1430 // We have a pending external suspend request so we leave the
1431 // suspend_equivalent flag set until java_suspend_self() sets
1432 // the ext_suspended flag and clears the suspend_equivalent
1433 // flag. This insures that wait_for_ext_suspend_completion()
1434 // will return consistent values.
1435 return ret;
1436 }
1437
1438 // utility methods to see if we are doing some kind of suspension
1439 bool is_being_ext_suspended() const {
1440 MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1441 return is_ext_suspended() || is_external_suspend();
1442 }
1443
1444 bool is_suspend_equivalent() const { return _suspend_equivalent; }
1445
1446 void set_suspend_equivalent() { _suspend_equivalent = true; }
1447 void clear_suspend_equivalent() { _suspend_equivalent = false; }
1448
1449 // Thread.stop support
1450 void send_thread_stop(oop throwable);
1451 AsyncRequests clear_special_runtime_exit_condition() {
1452 AsyncRequests x = _special_runtime_exit_condition;
1453 _special_runtime_exit_condition = _no_async_condition;
1454 return x;
1455 }
1456
1457 // Are any async conditions present?
1458 bool has_async_condition() { return (_special_runtime_exit_condition != _no_async_condition); }
1459
1460 void check_and_handle_async_exceptions(bool check_unsafe_error = true);
1461
1462 // these next two are also used for self-suspension and async exception support
1463 void handle_special_runtime_exit_condition(bool check_asyncs = true);
1464
1465 // Return true if JavaThread has an asynchronous condition or
1466 // if external suspension is requested.
1467 bool has_special_runtime_exit_condition() {
1468 // Because we don't use is_external_suspend_with_lock
1469 // it is possible that we won't see an asynchronous external suspend
1470 // request that has just gotten started, i.e., SR_lock grabbed but
1471 // _external_suspend field change either not made yet or not visible
1472 // yet. However, this is okay because the request is asynchronous and
1473 // we will see the new flag value the next time through. It's also
1474 // possible that the external suspend request is dropped after
1475 // we have checked is_external_suspend(), we will recheck its value
1476 // under SR_lock in java_suspend_self().
1477 return (_special_runtime_exit_condition != _no_async_condition) ||
1478 is_external_suspend() || is_trace_suspend();
1479 }
1480
1481 void set_pending_unsafe_access_error() { _special_runtime_exit_condition = _async_unsafe_access_error; }
1482
1483 inline void set_pending_async_exception(oop e);
1484
1485 // Fast-locking support
1486 bool is_lock_owned(address adr) const;
1487
1488 // Accessors for vframe array top
1489 // The linked list of vframe arrays are sorted on sp. This means when we
1490 // unpack the head must contain the vframe array to unpack.
1491 void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
1492 vframeArray* vframe_array_head() const { return _vframe_array_head; }
1493
1494 // Side structure for deferring update of java frame locals until deopt occurs
1495 GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred_locals() const { return _deferred_locals_updates; }
1496 void set_deferred_locals(GrowableArray<jvmtiDeferredLocalVariableSet *>* vf) { _deferred_locals_updates = vf; }
1497
1498 // These only really exist to make debugging deopt problems simpler
1499
1500 void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
1501 vframeArray* vframe_array_last() const { return _vframe_array_last; }
1502
1503 // The special resourceMark used during deoptimization
1504
1505 void set_deopt_mark(DeoptResourceMark* value) { _deopt_mark = value; }
1506 DeoptResourceMark* deopt_mark(void) { return _deopt_mark; }
1507
1508 void set_deopt_compiled_method(CompiledMethod* nm) { _deopt_nmethod = nm; }
1509 CompiledMethod* deopt_compiled_method() { return _deopt_nmethod; }
1510
1511 Method* callee_target() const { return _callee_target; }
1512 void set_callee_target (Method* x) { _callee_target = x; }
1513
1514 // Oop results of vm runtime calls
1515 oop vm_result() const { return _vm_result; }
1516 void set_vm_result (oop x) { _vm_result = x; }
1517
1518 Metadata* vm_result_2() const { return _vm_result_2; }
1519 void set_vm_result_2 (Metadata* x) { _vm_result_2 = x; }
1520
1521 MemRegion deferred_card_mark() const { return _deferred_card_mark; }
1522 void set_deferred_card_mark(MemRegion mr) { _deferred_card_mark = mr; }
1523
1524 #if INCLUDE_JVMCI
1525 int pending_deoptimization() const { return _pending_deoptimization; }
1526 jlong pending_failed_speculation() const { return _pending_failed_speculation; }
1527 bool has_pending_monitorenter() const { return _pending_monitorenter; }
1528 void set_pending_monitorenter(bool b) { _pending_monitorenter = b; }
1529 void set_pending_deoptimization(int reason) { _pending_deoptimization = reason; }
1530 void set_pending_failed_speculation(jlong failed_speculation) { _pending_failed_speculation = failed_speculation; }
1531 void set_pending_transfer_to_interpreter(bool b) { _pending_transfer_to_interpreter = b; }
1532 void set_jvmci_alternate_call_target(address a) { assert(_jvmci._alternate_call_target == NULL, "must be"); _jvmci._alternate_call_target = a; }
1533 void set_jvmci_implicit_exception_pc(address a) { assert(_jvmci._implicit_exception_pc == NULL, "must be"); _jvmci._implicit_exception_pc = a; }
1534
1535 virtual bool in_retryable_allocation() const { return _in_retryable_allocation; }
1536 void set_in_retryable_allocation(bool b) { _in_retryable_allocation = b; }
1537 #endif // INCLUDE_JVMCI
1538
1539 // Exception handling for compiled methods
1540 oop exception_oop() const { return _exception_oop; }
1541 address exception_pc() const { return _exception_pc; }
1542 address exception_handler_pc() const { return _exception_handler_pc; }
1543 bool is_method_handle_return() const { return _is_method_handle_return == 1; }
1544
1545 void set_exception_oop(oop o) { (void)const_cast<oop&>(_exception_oop = o); }
1546 void set_exception_pc(address a) { _exception_pc = a; }
1547 void set_exception_handler_pc(address a) { _exception_handler_pc = a; }
1548 void set_is_method_handle_return(bool value) { _is_method_handle_return = value ? 1 : 0; }
1549
1550 void clear_exception_oop_and_pc() {
1551 set_exception_oop(NULL);
1552 set_exception_pc(NULL);
1553 }
1554
1555 // Stack overflow support
1556 //
1557 // (small addresses)
1558 //
1559 // -- <-- stack_end() ---
1560 // | |
1561 // | red pages |
1562 // | |
1563 // -- <-- stack_red_zone_base() |
1564 // | |
1565 // | guard
1566 // | yellow pages zone
1567 // | |
1568 // | |
1569 // -- <-- stack_yellow_zone_base() |
1570 // | |
1571 // | |
1572 // | reserved pages |
1573 // | |
1574 // -- <-- stack_reserved_zone_base() --- ---
1575 // /|\ shadow <-- stack_overflow_limit() (somewhere in here)
1576 // | zone
1577 // \|/ size
1578 // some untouched memory ---
1579 //
1580 //
1581 // --
1582 // |
1583 // | shadow zone
1584 // |
1585 // --
1586 // x frame n
1587 // --
1588 // x frame n-1
1589 // x
1590 // --
1591 // ...
1592 //
1593 // --
1594 // x frame 0
1595 // -- <-- stack_base()
1596 //
1597 // (large addresses)
1598 //
1599
1600 private:
1601 // These values are derived from flags StackRedPages, StackYellowPages,
1602 // StackReservedPages and StackShadowPages. The zone size is determined
1603 // ergonomically if page_size > 4K.
1604 static size_t _stack_red_zone_size;
1605 static size_t _stack_yellow_zone_size;
1606 static size_t _stack_reserved_zone_size;
1607 static size_t _stack_shadow_zone_size;
1608 public:
1609 inline size_t stack_available(address cur_sp);
1610
1611 static size_t stack_red_zone_size() {
1612 assert(_stack_red_zone_size > 0, "Don't call this before the field is initialized.");
1613 return _stack_red_zone_size;
1614 }
1615 static void set_stack_red_zone_size(size_t s) {
1616 assert(is_aligned(s, os::vm_page_size()),
1617 "We can not protect if the red zone size is not page aligned.");
1618 assert(_stack_red_zone_size == 0, "This should be called only once.");
1619 _stack_red_zone_size = s;
1620 }
1621 address stack_red_zone_base() {
1622 return (address)(stack_end() + stack_red_zone_size());
1623 }
1624 bool in_stack_red_zone(address a) {
1625 return a <= stack_red_zone_base() && a >= stack_end();
1626 }
1627
1628 static size_t stack_yellow_zone_size() {
1629 assert(_stack_yellow_zone_size > 0, "Don't call this before the field is initialized.");
1630 return _stack_yellow_zone_size;
1631 }
1632 static void set_stack_yellow_zone_size(size_t s) {
1633 assert(is_aligned(s, os::vm_page_size()),
1634 "We can not protect if the yellow zone size is not page aligned.");
1635 assert(_stack_yellow_zone_size == 0, "This should be called only once.");
1636 _stack_yellow_zone_size = s;
1637 }
1638
1639 static size_t stack_reserved_zone_size() {
1640 // _stack_reserved_zone_size may be 0. This indicates the feature is off.
1641 return _stack_reserved_zone_size;
1642 }
1643 static void set_stack_reserved_zone_size(size_t s) {
1644 assert(is_aligned(s, os::vm_page_size()),
1645 "We can not protect if the reserved zone size is not page aligned.");
1646 assert(_stack_reserved_zone_size == 0, "This should be called only once.");
1647 _stack_reserved_zone_size = s;
1648 }
1649 address stack_reserved_zone_base() {
1650 return (address)(stack_end() +
1651 (stack_red_zone_size() + stack_yellow_zone_size() + stack_reserved_zone_size()));
1652 }
1653 bool in_stack_reserved_zone(address a) {
1654 return (a <= stack_reserved_zone_base()) &&
1655 (a >= (address)((intptr_t)stack_reserved_zone_base() - stack_reserved_zone_size()));
1656 }
1657
1658 static size_t stack_yellow_reserved_zone_size() {
1659 return _stack_yellow_zone_size + _stack_reserved_zone_size;
1660 }
1661 bool in_stack_yellow_reserved_zone(address a) {
1662 return (a <= stack_reserved_zone_base()) && (a >= stack_red_zone_base());
1663 }
1664
1665 // Size of red + yellow + reserved zones.
1666 static size_t stack_guard_zone_size() {
1667 return stack_red_zone_size() + stack_yellow_reserved_zone_size();
1668 }
1669
1670 static size_t stack_shadow_zone_size() {
1671 assert(_stack_shadow_zone_size > 0, "Don't call this before the field is initialized.");
1672 return _stack_shadow_zone_size;
1673 }
1674 static void set_stack_shadow_zone_size(size_t s) {
1675 // The shadow area is not allocated or protected, so
1676 // it needs not be page aligned.
1677 // But the stack bang currently assumes that it is a
1678 // multiple of page size. This guarantees that the bang
1679 // loop touches all pages in the shadow zone.
1680 // This can be guaranteed differently, as well. E.g., if
1681 // the page size is a multiple of 4K, banging in 4K steps
1682 // suffices to touch all pages. (Some pages are banged
1683 // several times, though.)
1684 assert(is_aligned(s, os::vm_page_size()),
1685 "Stack bang assumes multiple of page size.");
1686 assert(_stack_shadow_zone_size == 0, "This should be called only once.");
1687 _stack_shadow_zone_size = s;
1688 }
1689
1690 void create_stack_guard_pages();
1691 void remove_stack_guard_pages();
1692
1693 void enable_stack_reserved_zone();
1694 void disable_stack_reserved_zone();
1695 void enable_stack_yellow_reserved_zone();
1696 void disable_stack_yellow_reserved_zone();
1697 void enable_stack_red_zone();
1698 void disable_stack_red_zone();
1699
1700 inline bool stack_guard_zone_unused();
1701 inline bool stack_yellow_reserved_zone_disabled();
1702 inline bool stack_reserved_zone_disabled();
1703 inline bool stack_guards_enabled();
1704
1705 address reserved_stack_activation() const { return _reserved_stack_activation; }
1706 void set_reserved_stack_activation(address addr) {
1707 assert(_reserved_stack_activation == stack_base()
1708 || _reserved_stack_activation == NULL
1709 || addr == stack_base(), "Must not be set twice");
1710 _reserved_stack_activation = addr;
1711 }
1712
1713 // Attempt to reguard the stack after a stack overflow may have occurred.
1714 // Returns true if (a) guard pages are not needed on this thread, (b) the
1715 // pages are already guarded, or (c) the pages were successfully reguarded.
1716 // Returns false if there is not enough stack space to reguard the pages, in
1717 // which case the caller should unwind a frame and try again. The argument
1718 // should be the caller's (approximate) sp.
1719 bool reguard_stack(address cur_sp);
1720 // Similar to above but see if current stackpoint is out of the guard area
1721 // and reguard if possible.
1722 bool reguard_stack(void);
1723
1724 address stack_overflow_limit() { return _stack_overflow_limit; }
1725 void set_stack_overflow_limit() {
1726 _stack_overflow_limit =
1727 stack_end() + MAX2(JavaThread::stack_guard_zone_size(), JavaThread::stack_shadow_zone_size());
1728 }
1729
1730 // Misc. accessors/mutators
1731 void set_do_not_unlock(void) { _do_not_unlock_if_synchronized = true; }
1732 void clr_do_not_unlock(void) { _do_not_unlock_if_synchronized = false; }
1733 bool do_not_unlock(void) { return _do_not_unlock_if_synchronized; }
1734
1735 // For assembly stub generation
1736 static ByteSize threadObj_offset() { return byte_offset_of(JavaThread, _threadObj); }
1737 static ByteSize jni_environment_offset() { return byte_offset_of(JavaThread, _jni_environment); }
1738 static ByteSize pending_jni_exception_check_fn_offset() {
1739 return byte_offset_of(JavaThread, _pending_jni_exception_check_fn);
1740 }
1741 static ByteSize last_Java_sp_offset() {
1742 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
1743 }
1744 static ByteSize last_Java_pc_offset() {
1745 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
1746 }
1747 static ByteSize frame_anchor_offset() {
1748 return byte_offset_of(JavaThread, _anchor);
1749 }
1750 static ByteSize callee_target_offset() { return byte_offset_of(JavaThread, _callee_target); }
1751 static ByteSize vm_result_offset() { return byte_offset_of(JavaThread, _vm_result); }
1752 static ByteSize vm_result_2_offset() { return byte_offset_of(JavaThread, _vm_result_2); }
1753 static ByteSize thread_state_offset() { return byte_offset_of(JavaThread, _thread_state); }
1754 static ByteSize saved_exception_pc_offset() { return byte_offset_of(JavaThread, _saved_exception_pc); }
1755 static ByteSize osthread_offset() { return byte_offset_of(JavaThread, _osthread); }
1756 #if INCLUDE_JVMCI
1757 static ByteSize pending_deoptimization_offset() { return byte_offset_of(JavaThread, _pending_deoptimization); }
1758 static ByteSize pending_monitorenter_offset() { return byte_offset_of(JavaThread, _pending_monitorenter); }
1759 static ByteSize pending_failed_speculation_offset() { return byte_offset_of(JavaThread, _pending_failed_speculation); }
1760 static ByteSize jvmci_alternate_call_target_offset() { return byte_offset_of(JavaThread, _jvmci._alternate_call_target); }
1761 static ByteSize jvmci_implicit_exception_pc_offset() { return byte_offset_of(JavaThread, _jvmci._implicit_exception_pc); }
1762 static ByteSize jvmci_counters_offset() { return byte_offset_of(JavaThread, _jvmci_counters); }
1763 #endif // INCLUDE_JVMCI
1764 static ByteSize exception_oop_offset() { return byte_offset_of(JavaThread, _exception_oop); }
1765 static ByteSize exception_pc_offset() { return byte_offset_of(JavaThread, _exception_pc); }
1766 static ByteSize exception_handler_pc_offset() { return byte_offset_of(JavaThread, _exception_handler_pc); }
1767 static ByteSize stack_overflow_limit_offset() { return byte_offset_of(JavaThread, _stack_overflow_limit); }
1768 static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); }
1769 static ByteSize stack_guard_state_offset() { return byte_offset_of(JavaThread, _stack_guard_state); }
1770 static ByteSize reserved_stack_activation_offset() { return byte_offset_of(JavaThread, _reserved_stack_activation); }
1771 static ByteSize suspend_flags_offset() { return byte_offset_of(JavaThread, _suspend_flags); }
1772
1773 static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
1774 static ByteSize should_post_on_exceptions_flag_offset() {
1775 return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
1776 }
1777 static ByteSize doing_unsafe_access_offset() { return byte_offset_of(JavaThread, _doing_unsafe_access); }
1778
1779 // Returns the jni environment for this thread
1780 JNIEnv* jni_environment() { return &_jni_environment; }
1781
1782 static JavaThread* thread_from_jni_environment(JNIEnv* env) {
1783 JavaThread *thread_from_jni_env = (JavaThread*)((intptr_t)env - in_bytes(jni_environment_offset()));
1784 // Only return NULL if thread is off the thread list; starting to
1785 // exit should not return NULL.
1786 if (thread_from_jni_env->is_terminated()) {
1787 thread_from_jni_env->block_if_vm_exited();
1788 return NULL;
1789 } else {
1790 return thread_from_jni_env;
1791 }
1792 }
1793
1794 // JNI critical regions. These can nest.
1795 bool in_critical() { return _jni_active_critical > 0; }
1796 bool in_last_critical() { return _jni_active_critical == 1; }
1797 inline void enter_critical();
1798 void exit_critical() {
1799 assert(Thread::current() == this, "this must be current thread");
1800 _jni_active_critical--;
1801 assert(_jni_active_critical >= 0, "JNI critical nesting problem?");
1802 }
1803
1804 // Checked JNI: is the programmer required to check for exceptions, if so specify
1805 // which function name. Returning to a Java frame should implicitly clear the
1806 // pending check, this is done for Native->Java transitions (i.e. user JNI code).
1807 // VM->Java transistions are not cleared, it is expected that JNI code enclosed
1808 // within ThreadToNativeFromVM makes proper exception checks (i.e. VM internal).
1809 bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != NULL; }
1810 void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = NULL; }
1811 const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; }
1812 void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; }
1813
1814 // For deadlock detection
1815 int depth_first_number() { return _depth_first_number; }
1816 void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
1817
1818 private:
1819 void set_monitor_chunks(MonitorChunk* monitor_chunks) { _monitor_chunks = monitor_chunks; }
1820
1821 public:
1822 MonitorChunk* monitor_chunks() const { return _monitor_chunks; }
1823 void add_monitor_chunk(MonitorChunk* chunk);
1824 void remove_monitor_chunk(MonitorChunk* chunk);
1825 bool in_deopt_handler() const { return _in_deopt_handler > 0; }
1826 void inc_in_deopt_handler() { _in_deopt_handler++; }
1827 void dec_in_deopt_handler() {
1828 assert(_in_deopt_handler > 0, "mismatched deopt nesting");
1829 if (_in_deopt_handler > 0) { // robustness
1830 _in_deopt_handler--;
1831 }
1832 }
1833
1834 private:
1835 void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
1836
1837 public:
1838
1839 // Frame iteration; calls the function f for all frames on the stack
1840 void frames_do(void f(frame*, const RegisterMap*));
1841
1842 // Memory operations
1843 void oops_do(OopClosure* f, CodeBlobClosure* cf);
1844
1845 // Sweeper operations
1846 virtual void nmethods_do(CodeBlobClosure* cf);
1847
1848 // RedefineClasses Support
1849 void metadata_do(MetadataClosure* f);
1850
1851 // Debug method asserting thread states are correct during a handshake operation.
1852 DEBUG_ONLY(void verify_states_for_handshake();)
1853
1854 // Misc. operations
1855 char* name() const { return (char*)get_thread_name(); }
1856 void print_on(outputStream* st, bool print_extended_info) const;
1857 void print_on(outputStream* st) const { print_on(st, false); }
1858 void print() const;
1859 void print_thread_state_on(outputStream*) const PRODUCT_RETURN;
1860 void print_on_error(outputStream* st, char* buf, int buflen) const;
1861 void print_name_on_error(outputStream* st, char* buf, int buflen) const;
1862 void verify();
1863 const char* get_thread_name() const;
1864 protected:
1865 // factor out low-level mechanics for use in both normal and error cases
1866 virtual const char* get_thread_name_string(char* buf = NULL, int buflen = 0) const;
1867 public:
1868 // Accessing frames
1869 frame last_frame() {
1870 _anchor.make_walkable(this);
1871 return pd_last_frame();
1872 }
1873 javaVFrame* last_java_vframe(RegisterMap* reg_map);
1874
1875 // Returns method at 'depth' java or native frames down the stack
1876 // Used for security checks
1877 Klass* security_get_caller_class(int depth);
1878
1879 // Print stack trace in external format
1880 void print_stack_on(outputStream* st);
1881 void print_stack() { print_stack_on(tty); }
1882
1883 // Print stack traces in various internal formats
1884 void trace_stack() PRODUCT_RETURN;
1885 void trace_stack_from(vframe* start_vf) PRODUCT_RETURN;
1886 void trace_frames() PRODUCT_RETURN;
1887
1888 // Print an annotated view of the stack frames
1889 void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN;
1890 void validate_frame_layout() {
1891 print_frame_layout(0, true);
1892 }
1893
1894 // Function for testing deoptimization
1895 void deoptimize();
1896 void make_zombies();
1897
1898 void deoptimize_marked_methods();
1899
1900 public:
1901 // Returns the running thread as a JavaThread
1902 static inline JavaThread* current();
1903
1904 // Returns the active Java thread. Do not use this if you know you are calling
1905 // from a JavaThread, as it's slower than JavaThread::current. If called from
1906 // the VMThread, it also returns the JavaThread that instigated the VMThread's
1907 // operation. You may not want that either.
1908 static JavaThread* active();
1909
1910 inline CompilerThread* as_CompilerThread();
1911
1912 protected:
1913 virtual void pre_run();
1914 virtual void run();
1915 void thread_main_inner();
1916 virtual void post_run();
1917
1918
1919 private:
1920 GrowableArray<oop>* _array_for_gc;
1921 public:
1922
1923 void register_array_for_gc(GrowableArray<oop>* array) { _array_for_gc = array; }
1924
1925 public:
1926 // Thread local information maintained by JVMTI.
1927 void set_jvmti_thread_state(JvmtiThreadState *value) { _jvmti_thread_state = value; }
1928 // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1929 // getter is used to get this JavaThread's JvmtiThreadState if it has
1930 // one which means NULL can be returned. JvmtiThreadState::state_for()
1931 // is used to get the specified JavaThread's JvmtiThreadState if it has
1932 // one or it allocates a new JvmtiThreadState for the JavaThread and
1933 // returns it. JvmtiThreadState::state_for() will return NULL only if
1934 // the specified JavaThread is exiting.
1935 JvmtiThreadState *jvmti_thread_state() const { return _jvmti_thread_state; }
1936 static ByteSize jvmti_thread_state_offset() { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1937
1938 // JVMTI PopFrame support
1939 // Setting and clearing popframe_condition
1940 // All of these enumerated values are bits. popframe_pending
1941 // indicates that a PopFrame() has been requested and not yet been
1942 // completed. popframe_processing indicates that that PopFrame() is in
1943 // the process of being completed. popframe_force_deopt_reexecution_bit
1944 // indicates that special handling is required when returning to a
1945 // deoptimized caller.
1946 enum PopCondition {
1947 popframe_inactive = 0x00,
1948 popframe_pending_bit = 0x01,
1949 popframe_processing_bit = 0x02,
1950 popframe_force_deopt_reexecution_bit = 0x04
1951 };
1952 PopCondition popframe_condition() { return (PopCondition) _popframe_condition; }
1953 void set_popframe_condition(PopCondition c) { _popframe_condition = c; }
1954 void set_popframe_condition_bit(PopCondition c) { _popframe_condition |= c; }
1955 void clear_popframe_condition() { _popframe_condition = popframe_inactive; }
1956 static ByteSize popframe_condition_offset() { return byte_offset_of(JavaThread, _popframe_condition); }
1957 bool has_pending_popframe() { return (popframe_condition() & popframe_pending_bit) != 0; }
1958 bool popframe_forcing_deopt_reexecution() { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
1959 void clear_popframe_forcing_deopt_reexecution() { _popframe_condition &= ~popframe_force_deopt_reexecution_bit; }
1960 #ifdef CC_INTERP
1961 bool pop_frame_pending(void) { return ((_popframe_condition & popframe_pending_bit) != 0); }
1962 void clr_pop_frame_pending(void) { _popframe_condition = popframe_inactive; }
1963 bool pop_frame_in_process(void) { return ((_popframe_condition & popframe_processing_bit) != 0); }
1964 void set_pop_frame_in_process(void) { _popframe_condition |= popframe_processing_bit; }
1965 void clr_pop_frame_in_process(void) { _popframe_condition &= ~popframe_processing_bit; }
1966 #endif
1967
1968 int frames_to_pop_failed_realloc() const { return _frames_to_pop_failed_realloc; }
1969 void set_frames_to_pop_failed_realloc(int nb) { _frames_to_pop_failed_realloc = nb; }
1970 void dec_frames_to_pop_failed_realloc() { _frames_to_pop_failed_realloc--; }
1971
1972 private:
1973 // Saved incoming arguments to popped frame.
1974 // Used only when popped interpreted frame returns to deoptimized frame.
1975 void* _popframe_preserved_args;
1976 int _popframe_preserved_args_size;
1977
1978 public:
1979 void popframe_preserve_args(ByteSize size_in_bytes, void* start);
1980 void* popframe_preserved_args();
1981 ByteSize popframe_preserved_args_size();
1982 WordSize popframe_preserved_args_size_in_words();
1983 void popframe_free_preserved_args();
1984
1985
1986 private:
1987 JvmtiThreadState *_jvmti_thread_state;
1988
1989 // Used by the interpreter in fullspeed mode for frame pop, method
1990 // entry, method exit and single stepping support. This field is
1991 // only set to non-zero by the VM_EnterInterpOnlyMode VM operation.
1992 // It can be set to zero asynchronously (i.e., without a VM operation
1993 // or a lock) so we have to be very careful.
1994 int _interp_only_mode;
1995
1996 public:
1997 // used by the interpreter for fullspeed debugging support (see above)
1998 static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
1999 bool is_interp_only_mode() { return (_interp_only_mode != 0); }
2000 int get_interp_only_mode() { return _interp_only_mode; }
2001 void increment_interp_only_mode() { ++_interp_only_mode; }
2002 void decrement_interp_only_mode() { --_interp_only_mode; }
2003
2004 // support for cached flag that indicates whether exceptions need to be posted for this thread
2005 // if this is false, we can avoid deoptimizing when events are thrown
2006 // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
2007 private:
2008 int _should_post_on_exceptions_flag;
2009
2010 public:
2011 int should_post_on_exceptions_flag() { return _should_post_on_exceptions_flag; }
2012 void set_should_post_on_exceptions_flag(int val) { _should_post_on_exceptions_flag = val; }
2013
2014 private:
2015 ThreadStatistics *_thread_stat;
2016
2017 public:
2018 ThreadStatistics* get_thread_stat() const { return _thread_stat; }
2019
2020 // Return a blocker object for which this thread is blocked parking.
2021 oop current_park_blocker();
2022
2023 private:
2024 static size_t _stack_size_at_create;
2025
2026 public:
2027 static inline size_t stack_size_at_create(void) {
2028 return _stack_size_at_create;
2029 }
2030 static inline void set_stack_size_at_create(size_t value) {
2031 _stack_size_at_create = value;
2032 }
2033
2034 // Machine dependent stuff
2035 #include OS_CPU_HEADER(thread)
2036
2037 // JSR166 per-thread parker
2038 private:
2039 Parker* _parker;
2040 public:
2041 Parker* parker() { return _parker; }
2042
2043 // Biased locking support
2044 private:
2045 GrowableArray<MonitorInfo*>* _cached_monitor_info;
2046 public:
2047 GrowableArray<MonitorInfo*>* cached_monitor_info() { return _cached_monitor_info; }
2048 void set_cached_monitor_info(GrowableArray<MonitorInfo*>* info) { _cached_monitor_info = info; }
2049
2050 // clearing/querying jni attach status
2051 bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; }
2052 bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
2053 inline void set_done_attaching_via_jni();
2054
2055 // Stack dump assistance:
2056 // Track the class we want to initialize but for which we have to wait
2057 // on its init_lock() because it is already being initialized.
2058 void set_class_to_be_initialized(InstanceKlass* k);
2059 InstanceKlass* class_to_be_initialized() const;
2060
2061 private:
2062 InstanceKlass* _class_to_be_initialized;
2063
2064 // java.lang.Thread.sleep support
2065 ParkEvent * _SleepEvent;
2066 public:
2067 bool sleep(jlong millis);
2068
2069 // java.lang.Thread interruption support
2070 void interrupt();
2071 bool is_interrupted(bool clear_interrupted);
2072
2073 };
2074
2075 // Inline implementation of JavaThread::current
2076 inline JavaThread* JavaThread::current() {
2077 Thread* thread = Thread::current();
2078 assert(thread->is_Java_thread(), "just checking");
2079 return (JavaThread*)thread;
2080 }
2081
2082 inline CompilerThread* JavaThread::as_CompilerThread() {
2083 assert(is_Compiler_thread(), "just checking");
2084 return (CompilerThread*)this;
2085 }
2086
2087 // Dedicated thread to sweep the code cache
2088 class CodeCacheSweeperThread : public JavaThread {
2089 CompiledMethod* _scanned_compiled_method; // nmethod being scanned by the sweeper
2090 public:
2091 CodeCacheSweeperThread();
2092 // Track the nmethod currently being scanned by the sweeper
2093 void set_scanned_compiled_method(CompiledMethod* cm) {
2094 assert(_scanned_compiled_method == NULL || cm == NULL, "should reset to NULL before writing a new value");
2095 _scanned_compiled_method = cm;
2096 }
2097
2098 // Hide sweeper thread from external view.
2099 bool is_hidden_from_external_view() const { return true; }
2100
2101 bool is_Code_cache_sweeper_thread() const { return true; }
2102
2103 // Prevent GC from unloading _scanned_compiled_method
2104 void oops_do(OopClosure* f, CodeBlobClosure* cf);
2105 void nmethods_do(CodeBlobClosure* cf);
2106 };
2107
2108 // A thread used for Compilation.
2109 class CompilerThread : public JavaThread {
2110 friend class VMStructs;
2111 private:
2112 CompilerCounters* _counters;
2113
2114 ciEnv* _env;
2115 CompileLog* _log;
2116 CompileTask* volatile _task; // print_threads_compiling can read this concurrently.
2117 CompileQueue* _queue;
2118 BufferBlob* _buffer_blob;
2119
2120 AbstractCompiler* _compiler;
2121 TimeStamp _idle_time;
2122
2123 public:
2124
2125 static CompilerThread* current();
2126
2127 CompilerThread(CompileQueue* queue, CompilerCounters* counters);
2128 ~CompilerThread();
2129
2130 bool is_Compiler_thread() const { return true; }
2131
2132 virtual bool can_call_java() const;
2133
2134 // Hide native compiler threads from external view.
2135 bool is_hidden_from_external_view() const { return !can_call_java(); }
2136
2137 void set_compiler(AbstractCompiler* c) { _compiler = c; }
2138 AbstractCompiler* compiler() const { return _compiler; }
2139
2140 CompileQueue* queue() const { return _queue; }
2141 CompilerCounters* counters() const { return _counters; }
2142
2143 // Get/set the thread's compilation environment.
2144 ciEnv* env() { return _env; }
2145 void set_env(ciEnv* env) { _env = env; }
2146
2147 BufferBlob* get_buffer_blob() const { return _buffer_blob; }
2148 void set_buffer_blob(BufferBlob* b) { _buffer_blob = b; }
2149
2150 // Get/set the thread's logging information
2151 CompileLog* log() { return _log; }
2152 void init_log(CompileLog* log) {
2153 // Set once, for good.
2154 assert(_log == NULL, "set only once");
2155 _log = log;
2156 }
2157
2158 void start_idle_timer() { _idle_time.update(); }
2159 jlong idle_time_millis() {
2160 return TimeHelper::counter_to_millis(_idle_time.ticks_since_update());
2161 }
2162
2163 #ifndef PRODUCT
2164 private:
2165 IdealGraphPrinter *_ideal_graph_printer;
2166 public:
2167 IdealGraphPrinter *ideal_graph_printer() { return _ideal_graph_printer; }
2168 void set_ideal_graph_printer(IdealGraphPrinter *n) { _ideal_graph_printer = n; }
2169 #endif
2170
2171 // Get/set the thread's current task
2172 CompileTask* task() { return _task; }
2173 void set_task(CompileTask* task) { _task = task; }
2174 };
2175
2176 inline CompilerThread* CompilerThread::current() {
2177 return JavaThread::current()->as_CompilerThread();
2178 }
2179
2180 // The active thread queue. It also keeps track of the current used
2181 // thread priorities.
2182 class Threads: AllStatic {
2183 friend class VMStructs;
2184 private:
2185 static int _number_of_threads;
2186 static int _number_of_non_daemon_threads;
2187 static int _return_code;
2188 static uintx _thread_claim_token;
2189 #ifdef ASSERT
2190 static bool _vm_complete;
2191 #endif
2192
2193 static void initialize_java_lang_classes(JavaThread* main_thread, TRAPS);
2194 static void initialize_jsr292_core_classes(TRAPS);
2195
2196 public:
2197 // Thread management
2198 // force_daemon is a concession to JNI, where we may need to add a
2199 // thread to the thread list before allocating its thread object
2200 static void add(JavaThread* p, bool force_daemon = false);
2201 static void remove(JavaThread* p, bool is_daemon);
2202 static void non_java_threads_do(ThreadClosure* tc);
2203 static void java_threads_do(ThreadClosure* tc);
2204 static void java_threads_and_vm_thread_do(ThreadClosure* tc);
2205 static void threads_do(ThreadClosure* tc);
2206 static void possibly_parallel_threads_do(bool is_par, ThreadClosure* tc);
2207
2208 // Initializes the vm and creates the vm thread
2209 static jint create_vm(JavaVMInitArgs* args, bool* canTryAgain);
2210 static void convert_vm_init_libraries_to_agents();
2211 static void create_vm_init_libraries();
2212 static void create_vm_init_agents();
2213 static void shutdown_vm_agents();
2214 static bool destroy_vm();
2215 // Supported VM versions via JNI
2216 // Includes JNI_VERSION_1_1
2217 static jboolean is_supported_jni_version_including_1_1(jint version);
2218 // Does not include JNI_VERSION_1_1
2219 static jboolean is_supported_jni_version(jint version);
2220
2221 // The "thread claim token" provides a way for threads to be claimed
2222 // by parallel worker tasks.
2223 //
2224 // Each thread contains a "token" field. A task will claim the
2225 // thread only if its token is different from the global token,
2226 // which is updated by calling change_thread_claim_token(). When
2227 // a thread is claimed, it's token is set to the global token value
2228 // so other threads in the same iteration pass won't claim it.
2229 //
2230 // For this to work change_thread_claim_token() needs to be called
2231 // exactly once in sequential code before starting parallel tasks
2232 // that should claim threads.
2233 //
2234 // New threads get their token set to 0 and change_thread_claim_token()
2235 // never sets the global token to 0.
2236 static uintx thread_claim_token() { return _thread_claim_token; }
2237 static void change_thread_claim_token();
2238 static void assert_all_threads_claimed() NOT_DEBUG_RETURN;
2239
2240 // Apply "f->do_oop" to all root oops in all threads.
2241 // This version may only be called by sequential code.
2242 static void oops_do(OopClosure* f, CodeBlobClosure* cf);
2243 // This version may be called by sequential or parallel code.
2244 static void possibly_parallel_oops_do(bool is_par, OopClosure* f, CodeBlobClosure* cf);
2245
2246 // Sweeper
2247 static void nmethods_do(CodeBlobClosure* cf);
2248
2249 // RedefineClasses support
2250 static void metadata_do(MetadataClosure* f);
2251 static void metadata_handles_do(void f(Metadata*));
2252
2253 #ifdef ASSERT
2254 static bool is_vm_complete() { return _vm_complete; }
2255 #endif // ASSERT
2256
2257 // Verification
2258 static void verify();
2259 static void print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks, bool print_extended_info);
2260 static void print(bool print_stacks, bool internal_format) {
2261 // this function is only used by debug.cpp
2262 print_on(tty, print_stacks, internal_format, false /* no concurrent lock printed */, false /* simple format */);
2263 }
2264 static void print_on_error(outputStream* st, Thread* current, char* buf, int buflen);
2265 static void print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
2266 int buflen, bool* found_current);
2267 static void print_threads_compiling(outputStream* st, char* buf, int buflen, bool short_form = false);
2268
2269 // Get Java threads that are waiting to enter a monitor.
2270 static GrowableArray<JavaThread*>* get_pending_threads(ThreadsList * t_list,
2271 int count, address monitor);
2272
2273 // Get owning Java thread from the monitor's owner field.
2274 static JavaThread *owning_thread_from_monitor_owner(ThreadsList * t_list,
2275 address owner);
2276
2277 // Number of threads on the active threads list
2278 static int number_of_threads() { return _number_of_threads; }
2279 // Number of non-daemon threads on the active threads list
2280 static int number_of_non_daemon_threads() { return _number_of_non_daemon_threads; }
2281
2282 // Deoptimizes all frames tied to marked nmethods
2283 static void deoptimized_wrt_marked_nmethods();
2284
2285 struct Test; // For private gtest access.
2286 };
2287
2288
2289 // Thread iterator
2290 class ThreadClosure: public StackObj {
2291 public:
2292 virtual void do_thread(Thread* thread) = 0;
2293 };
2294
2295 class SignalHandlerMark: public StackObj {
2296 private:
2297 Thread* _thread;
2298 public:
2299 SignalHandlerMark(Thread* t) {
2300 _thread = t;
2301 if (_thread) _thread->enter_signal_handler();
2302 }
2303 ~SignalHandlerMark() {
2304 if (_thread) _thread->leave_signal_handler();
2305 _thread = NULL;
2306 }
2307 };
2308
2309
2310 #endif // SHARE_RUNTIME_THREAD_HPP