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