1 /*
2 * Copyright (c) 1997, 2020, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #ifndef SHARE_RUNTIME_THREAD_HPP
26 #define SHARE_RUNTIME_THREAD_HPP
27
28 #include "jni.h"
29 #include "gc/shared/gcThreadLocalData.hpp"
30 #include "gc/shared/threadLocalAllocBuffer.hpp"
31 #include "memory/allocation.hpp"
32 #include "oops/oop.hpp"
33 #include "prims/jvmtiExport.hpp"
34 #include "runtime/frame.hpp"
35 #include "runtime/globals.hpp"
36 #include "runtime/handshake.hpp"
37 #include "runtime/javaFrameAnchor.hpp"
38 #include "runtime/jniHandles.hpp"
39 #include "runtime/mutexLocker.hpp"
40 #include "runtime/os.hpp"
41 #include "runtime/osThread.hpp"
42 #include "runtime/park.hpp"
43 #include "runtime/stubRoutines.hpp"
44 #include "runtime/threadHeapSampler.hpp"
45 #include "runtime/threadLocalStorage.hpp"
46 #include "runtime/threadStatisticalInfo.hpp"
47 #include "runtime/unhandledOops.hpp"
48 #include "utilities/align.hpp"
49 #include "utilities/exceptions.hpp"
50 #include "utilities/globalDefinitions.hpp"
51 #include "utilities/macros.hpp"
52 #if INCLUDE_JFR
53 #include "jfr/support/jfrThreadExtension.hpp"
54 #endif
55
56
57 class SafeThreadsListPtr;
58 class ThreadSafepointState;
59 class ThreadsList;
60 class ThreadsSMRSupport;
61
62 class JvmtiRawMonitor;
63 class JvmtiThreadState;
64 class ThreadStatistics;
65 class ConcurrentLocksDump;
66 class ParkEvent;
67 class Parker;
68 class MonitorInfo;
69
70 class AbstractCompiler;
71 class ciEnv;
72 class CompileThread;
73 class CompileLog;
74 class CompileTask;
75 class CompileQueue;
76 class CompilerCounters;
77
78 class vframeArray;
79 class vframe;
80 class javaVFrame;
81
82 class DeoptResourceMark;
83 class jvmtiDeferredLocalVariableSet;
84
85 class ThreadClosure;
86 class ICRefillVerifier;
87 class IdealGraphPrinter;
88
89 class JVMCIEnv;
90 class JVMCIPrimitiveArray;
91
92 class Metadata;
93 class ResourceArea;
94
95 DEBUG_ONLY(class ResourceMark;)
96
97 class WorkerThread;
98
99 // Class hierarchy
100 // - Thread
101 // - JavaThread
102 // - various subclasses eg CompilerThread, ServiceThread
103 // - NonJavaThread
104 // - NamedThread
105 // - VMThread
106 // - ConcurrentGCThread
107 // - WorkerThread
108 // - GangWorker
109 // - WatcherThread
110 // - JfrThreadSampler
111 //
112 // All Thread subclasses must be either JavaThread or NonJavaThread.
113 // This means !t->is_Java_thread() iff t is a NonJavaThread, or t is
114 // a partially constructed/destroyed Thread.
115
116 // Thread execution sequence and actions:
117 // All threads:
118 // - thread_native_entry // per-OS native entry point
119 // - stack initialization
120 // - other OS-level initialization (signal masks etc)
121 // - handshake with creating thread (if not started suspended)
122 // - this->call_run() // common shared entry point
123 // - shared common initialization
124 // - this->pre_run() // virtual per-thread-type initialization
125 // - this->run() // virtual per-thread-type "main" logic
126 // - shared common tear-down
127 // - this->post_run() // virtual per-thread-type tear-down
128 // - // 'this' no longer referenceable
129 // - OS-level tear-down (minimal)
130 // - final logging
131 //
132 // For JavaThread:
133 // - this->run() // virtual but not normally overridden
134 // - this->thread_main_inner() // extra call level to ensure correct stack calculations
135 // - this->entry_point() // set differently for each kind of JavaThread
136
137 class Thread: public ThreadShadow {
138 friend class VMStructs;
139 friend class JVMCIVMStructs;
140 private:
141
142 #ifndef USE_LIBRARY_BASED_TLS_ONLY
143 // Current thread is maintained as a thread-local variable
144 static THREAD_LOCAL Thread* _thr_current;
145 #endif
146
147 // Thread local data area available to the GC. The internal
148 // structure and contents of this data area is GC-specific.
149 // Only GC and GC barrier code should access this data area.
150 GCThreadLocalData _gc_data;
151
152 public:
153 static ByteSize gc_data_offset() {
154 return byte_offset_of(Thread, _gc_data);
155 }
156
157 template <typename T> T* gc_data() {
158 STATIC_ASSERT(sizeof(T) <= sizeof(_gc_data));
159 return reinterpret_cast<T*>(&_gc_data);
160 }
161
162 // Exception handling
163 // (Note: _pending_exception and friends are in ThreadShadow)
164 //oop _pending_exception; // pending exception for current thread
165 // const char* _exception_file; // file information for exception (debugging only)
166 // int _exception_line; // line information for exception (debugging only)
167 protected:
168
169 DEBUG_ONLY(static Thread* _starting_thread;)
170
171 // Support for forcing alignment of thread objects for biased locking
172 void* _real_malloc_address;
173
174 // JavaThread lifecycle support:
175 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
176 friend class ScanHazardPtrGatherProtectedThreadsClosure; // for cmpxchg_threads_hazard_ptr(), get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
177 friend class ScanHazardPtrGatherThreadsListClosure; // for get_threads_hazard_ptr(), untag_hazard_ptr() access
178 friend class ScanHazardPtrPrintMatchingThreadsClosure; // for get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
179 friend class ThreadsSMRSupport; // for _nested_threads_hazard_ptr_cnt, _threads_hazard_ptr, _threads_list_ptr access
180
181 ThreadsList* volatile _threads_hazard_ptr;
182 SafeThreadsListPtr* _threads_list_ptr;
183 ThreadsList* cmpxchg_threads_hazard_ptr(ThreadsList* exchange_value, ThreadsList* compare_value);
184 ThreadsList* get_threads_hazard_ptr();
185 void set_threads_hazard_ptr(ThreadsList* new_list);
186 static bool is_hazard_ptr_tagged(ThreadsList* list) {
187 return (intptr_t(list) & intptr_t(1)) == intptr_t(1);
188 }
189 static ThreadsList* tag_hazard_ptr(ThreadsList* list) {
190 return (ThreadsList*)(intptr_t(list) | intptr_t(1));
191 }
192 static ThreadsList* untag_hazard_ptr(ThreadsList* list) {
193 return (ThreadsList*)(intptr_t(list) & ~intptr_t(1));
194 }
195 // This field is enabled via -XX:+EnableThreadSMRStatistics:
196 uint _nested_threads_hazard_ptr_cnt;
197 void dec_nested_threads_hazard_ptr_cnt() {
198 assert(_nested_threads_hazard_ptr_cnt != 0, "mismatched {dec,inc}_nested_threads_hazard_ptr_cnt()");
199 _nested_threads_hazard_ptr_cnt--;
200 }
201 void inc_nested_threads_hazard_ptr_cnt() {
202 _nested_threads_hazard_ptr_cnt++;
203 }
204 uint nested_threads_hazard_ptr_cnt() {
205 return _nested_threads_hazard_ptr_cnt;
206 }
207
208 public:
209 void* operator new(size_t size) throw() { return allocate(size, true); }
210 void* operator new(size_t size, const std::nothrow_t& nothrow_constant) throw() {
211 return allocate(size, false); }
212 void operator delete(void* p);
213
214 protected:
215 static void* allocate(size_t size, bool throw_excpt, MEMFLAGS flags = mtThread);
216 private:
217
218 // ***************************************************************
219 // Suspend and resume support
220 // ***************************************************************
221 //
222 // VM suspend/resume no longer exists - it was once used for various
223 // things including safepoints but was deprecated and finally removed
224 // in Java 7. Because VM suspension was considered "internal" Java-level
225 // suspension was considered "external", and this legacy naming scheme
226 // remains.
227 //
228 // External suspend/resume requests come from JVM_SuspendThread,
229 // JVM_ResumeThread, JVMTI SuspendThread, and finally JVMTI
230 // ResumeThread. External
231 // suspend requests cause _external_suspend to be set and external
232 // resume requests cause _external_suspend to be cleared.
233 // External suspend requests do not nest on top of other external
234 // suspend requests. The higher level APIs reject suspend requests
235 // for already suspended threads.
236 //
237 // The external_suspend
238 // flag is checked by has_special_runtime_exit_condition() and java thread
239 // will self-suspend when handle_special_runtime_exit_condition() is
240 // called. Most uses of the _thread_blocked state in JavaThreads are
241 // considered the same as being externally suspended; if the blocking
242 // condition lifts, the JavaThread will self-suspend. Other places
243 // where VM checks for external_suspend include:
244 // + mutex granting (do not enter monitors when thread is suspended)
245 // + state transitions from _thread_in_native
246 //
247 // In general, java_suspend() does not wait for an external suspend
248 // request to complete. When it returns, the only guarantee is that
249 // the _external_suspend field is true.
250 //
251 // wait_for_ext_suspend_completion() is used to wait for an external
252 // suspend request to complete. External suspend requests are usually
253 // followed by some other interface call that requires the thread to
254 // be quiescent, e.g., GetCallTrace(). By moving the "wait time" into
255 // the interface that requires quiescence, we give the JavaThread a
256 // chance to self-suspend before we need it to be quiescent. This
257 // improves overall suspend/query performance.
258 //
259 // _suspend_flags controls the behavior of java_ suspend/resume.
260 // It must be set under the protection of SR_lock. Read from the flag is
261 // OK without SR_lock as long as the value is only used as a hint.
262 // (e.g., check _external_suspend first without lock and then recheck
263 // inside SR_lock and finish the suspension)
264 //
265 // _suspend_flags is also overloaded for other "special conditions" so
266 // that a single check indicates whether any special action is needed
267 // eg. for async exceptions.
268 // -------------------------------------------------------------------
269 // Notes:
270 // 1. The suspend/resume logic no longer uses ThreadState in OSThread
271 // but we still update its value to keep other part of the system (mainly
272 // JVMTI) happy. ThreadState is legacy code (see notes in
273 // osThread.hpp).
274 //
275 // 2. It would be more natural if set_external_suspend() is private and
276 // part of java_suspend(), but that probably would affect the suspend/query
277 // performance. Need more investigation on this.
278
279 // suspend/resume lock: used for self-suspend
280 Monitor* _SR_lock;
281
282 protected:
283 enum SuspendFlags {
284 // NOTE: avoid using the sign-bit as cc generates different test code
285 // when the sign-bit is used, and sometimes incorrectly - see CR 6398077
286
287 _external_suspend = 0x20000000U, // thread is asked to self suspend
288 _ext_suspended = 0x40000000U, // thread has self-suspended
289
290 _has_async_exception = 0x00000001U, // there is a pending async exception
291 _critical_native_unlock = 0x00000002U, // Must call back to unlock JNI critical lock
292
293 _trace_flag = 0x00000004U // call tracing backend
294 };
295
296 // various suspension related flags - atomically updated
297 // overloaded for async exception checking in check_special_condition_for_native_trans.
298 volatile uint32_t _suspend_flags;
299
300 private:
301 int _num_nested_signal;
302
303 DEBUG_ONLY(bool _suspendible_thread;)
304
305 public:
306 void enter_signal_handler() { _num_nested_signal++; }
307 void leave_signal_handler() { _num_nested_signal--; }
308 bool is_inside_signal_handler() const { return _num_nested_signal > 0; }
309
310 // Determines if a heap allocation failure will be retried
311 // (e.g., by deoptimizing and re-executing in the interpreter).
312 // In this case, the failed allocation must raise
313 // Universe::out_of_memory_error_retry() and omit side effects
314 // such as JVMTI events and handling -XX:+HeapDumpOnOutOfMemoryError
315 // and -XX:OnOutOfMemoryError.
316 virtual bool in_retryable_allocation() const { return false; }
317
318 #ifdef ASSERT
319 void set_suspendible_thread() {
320 _suspendible_thread = true;
321 }
322
323 void clear_suspendible_thread() {
324 _suspendible_thread = false;
325 }
326
327 bool is_suspendible_thread() { return _suspendible_thread; }
328 #endif
329
330 private:
331 // Active_handles points to a block of handles
332 JNIHandleBlock* _active_handles;
333
334 // One-element thread local free list
335 JNIHandleBlock* _free_handle_block;
336
337 // Point to the last handle mark
338 HandleMark* _last_handle_mark;
339
340 // Claim value for parallel iteration over threads.
341 uintx _threads_do_token;
342
343 // Support for GlobalCounter
344 private:
345 volatile uintx _rcu_counter;
346 public:
347 volatile uintx* get_rcu_counter() {
348 return &_rcu_counter;
349 }
350
351 public:
352 void set_last_handle_mark(HandleMark* mark) { _last_handle_mark = mark; }
353 HandleMark* last_handle_mark() const { return _last_handle_mark; }
354 private:
355
356 #ifdef ASSERT
357 ICRefillVerifier* _missed_ic_stub_refill_verifier;
358
359 public:
360 ICRefillVerifier* missed_ic_stub_refill_verifier() {
361 return _missed_ic_stub_refill_verifier;
362 }
363
364 void set_missed_ic_stub_refill_verifier(ICRefillVerifier* verifier) {
365 _missed_ic_stub_refill_verifier = verifier;
366 }
367 #endif // ASSERT
368
369 private:
370
371 // Debug support for checking if code allows safepoints or not.
372 // Safepoints in the VM can happen because of allocation, invoking a VM operation, or blocking on
373 // mutex, or blocking on an object synchronizer (Java locking).
374 // If _no_safepoint_count is non-zero, then an assertion failure will happen in any of
375 // the above cases.
376 //
377 // The class NoSafepointVerifier is used to set this counter.
378 //
379 NOT_PRODUCT(int _no_safepoint_count;) // If 0, thread allow a safepoint to happen
380
381 private:
382 // Used by SkipGCALot class.
383 NOT_PRODUCT(bool _skip_gcalot;) // Should we elide gc-a-lot?
384
385 friend class GCLocker;
386 friend class NoSafepointVerifier;
387 friend class PauseNoSafepointVerifier;
388
389 volatile void* _polling_page; // Thread local polling page
390
391 ThreadLocalAllocBuffer _tlab; // Thread-local eden
392 jlong _allocated_bytes; // Cumulative number of bytes allocated on
393 // the Java heap
394 ThreadHeapSampler _heap_sampler; // For use when sampling the memory.
395
396 ThreadStatisticalInfo _statistical_info; // Statistics about the thread
397
398 JFR_ONLY(DEFINE_THREAD_LOCAL_FIELD_JFR;) // Thread-local data for jfr
399
400 int _vm_operation_started_count; // VM_Operation support
401 int _vm_operation_completed_count; // VM_Operation support
402
403 ObjectMonitor* _current_pending_monitor; // ObjectMonitor this thread
404 // is waiting to lock
405 bool _current_pending_monitor_is_from_java; // locking is from Java code
406 JvmtiRawMonitor* _current_pending_raw_monitor; // JvmtiRawMonitor this thread
407 // is waiting to lock
408
409
410 // ObjectMonitor on which this thread called Object.wait()
411 ObjectMonitor* _current_waiting_monitor;
412
413 // Per-thread ObjectMonitor lists:
414 public:
415 ObjectMonitor* om_free_list; // SLL of free ObjectMonitors
416 int om_free_count; // # on om_free_list
417 int om_free_provision; // # to try to allocate next
418 ObjectMonitor* om_in_use_list; // SLL of in-use ObjectMonitors
419 int om_in_use_count; // # on om_in_use_list
420
421 #ifdef ASSERT
422 private:
423 volatile uint64_t _visited_for_critical_count;
424
425 public:
426 void set_visited_for_critical_count(uint64_t safepoint_id) {
427 assert(_visited_for_critical_count == 0, "Must be reset before set");
428 assert((safepoint_id & 0x1) == 1, "Must be odd");
429 _visited_for_critical_count = safepoint_id;
430 }
431 void reset_visited_for_critical_count(uint64_t safepoint_id) {
432 assert(_visited_for_critical_count == safepoint_id, "Was not visited");
433 _visited_for_critical_count = 0;
434 }
435 bool was_visited_for_critical_count(uint64_t safepoint_id) const {
436 return _visited_for_critical_count == safepoint_id;
437 }
438 #endif
439
440 public:
441 enum {
442 is_definitely_current_thread = true
443 };
444
445 // Constructor
446 Thread();
447 virtual ~Thread() = 0; // Thread is abstract.
448
449 // Manage Thread::current()
450 void initialize_thread_current();
451 static void clear_thread_current(); // TLS cleanup needed before threads terminate
452
453 protected:
454 // To be implemented by children.
455 virtual void run() = 0;
456 virtual void pre_run() = 0;
457 virtual void post_run() = 0; // Note: Thread must not be deleted prior to calling this!
458
459 #ifdef ASSERT
460 enum RunState {
461 PRE_CALL_RUN,
462 CALL_RUN,
463 PRE_RUN,
464 RUN,
465 POST_RUN
466 // POST_CALL_RUN - can't define this one as 'this' may be deleted when we want to set it
467 };
468 RunState _run_state; // for lifecycle checks
469 #endif
470
471
472 public:
473 // invokes <ChildThreadClass>::run(), with common preparations and cleanups.
474 void call_run();
475
476 // Testers
477 virtual bool is_VM_thread() const { return false; }
478 virtual bool is_Java_thread() const { return false; }
479 virtual bool is_Compiler_thread() const { return false; }
480 virtual bool is_Code_cache_sweeper_thread() const { return false; }
481 virtual bool is_service_thread() const { return false; }
482 virtual bool is_hidden_from_external_view() const { return false; }
483 virtual bool is_jvmti_agent_thread() const { return false; }
484 // True iff the thread can perform GC operations at a safepoint.
485 // Generally will be true only of VM thread and parallel GC WorkGang
486 // threads.
487 virtual bool is_GC_task_thread() const { return false; }
488 virtual bool is_Watcher_thread() const { return false; }
489 virtual bool is_ConcurrentGC_thread() const { return false; }
490 virtual bool is_Named_thread() const { return false; }
491 virtual bool is_Worker_thread() const { return false; }
492
493 // Can this thread make Java upcalls
494 virtual bool can_call_java() const { return false; }
495
496 // Is this a JavaThread that is on the VM's current ThreadsList?
497 // If so it must participate in the safepoint protocol.
498 virtual bool is_active_Java_thread() const { return false; }
499
500 // Casts
501 virtual WorkerThread* as_Worker_thread() const { return NULL; }
502
503 virtual char* name() const { return (char*)"Unknown thread"; }
504
505 // Returns the current thread (ASSERTS if NULL)
506 static inline Thread* current();
507 // Returns the current thread, or NULL if not attached
508 static inline Thread* current_or_null();
509 // Returns the current thread, or NULL if not attached, and is
510 // safe for use from signal-handlers
511 static inline Thread* current_or_null_safe();
512
513 // Common thread operations
514 #ifdef ASSERT
515 static void check_for_dangling_thread_pointer(Thread *thread);
516 #endif
517 static void set_priority(Thread* thread, ThreadPriority priority);
518 static ThreadPriority get_priority(const Thread* const thread);
519 static void start(Thread* thread);
520
521 void set_native_thread_name(const char *name) {
522 assert(Thread::current() == this, "set_native_thread_name can only be called on the current thread");
523 os::set_native_thread_name(name);
524 }
525
526 Monitor* SR_lock() const { return _SR_lock; }
527
528 bool has_async_exception() const { return (_suspend_flags & _has_async_exception) != 0; }
529
530 inline void set_suspend_flag(SuspendFlags f);
531 inline void clear_suspend_flag(SuspendFlags f);
532
533 inline void set_has_async_exception();
534 inline void clear_has_async_exception();
535
536 bool do_critical_native_unlock() const { return (_suspend_flags & _critical_native_unlock) != 0; }
537
538 inline void set_critical_native_unlock();
539 inline void clear_critical_native_unlock();
540
541 inline void set_trace_flag();
542 inline void clear_trace_flag();
543
544 // Support for Unhandled Oop detection
545 // Add the field for both, fastdebug and debug, builds to keep
546 // Thread's fields layout the same.
547 // Note: CHECK_UNHANDLED_OOPS is defined only for fastdebug build.
548 #ifdef CHECK_UNHANDLED_OOPS
549 private:
550 UnhandledOops* _unhandled_oops;
551 #elif defined(ASSERT)
552 private:
553 void* _unhandled_oops;
554 #endif
555 #ifdef CHECK_UNHANDLED_OOPS
556 public:
557 UnhandledOops* unhandled_oops() { return _unhandled_oops; }
558 // Mark oop safe for gc. It may be stack allocated but won't move.
559 void allow_unhandled_oop(oop *op) {
560 if (CheckUnhandledOops) unhandled_oops()->allow_unhandled_oop(op);
561 }
562 // Clear oops at safepoint so crashes point to unhandled oop violator
563 void clear_unhandled_oops() {
564 if (CheckUnhandledOops) unhandled_oops()->clear_unhandled_oops();
565 }
566 #endif // CHECK_UNHANDLED_OOPS
567
568 public:
569 #ifndef PRODUCT
570 bool skip_gcalot() { return _skip_gcalot; }
571 void set_skip_gcalot(bool v) { _skip_gcalot = v; }
572 #endif
573
574 // Installs a pending exception to be inserted later
575 static void send_async_exception(oop thread_oop, oop java_throwable);
576
577 // Resource area
578 ResourceArea* resource_area() const { return _resource_area; }
579 void set_resource_area(ResourceArea* area) { _resource_area = area; }
580
581 OSThread* osthread() const { return _osthread; }
582 void set_osthread(OSThread* thread) { _osthread = thread; }
583
584 // JNI handle support
585 JNIHandleBlock* active_handles() const { return _active_handles; }
586 void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
587 JNIHandleBlock* free_handle_block() const { return _free_handle_block; }
588 void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
589
590 // Internal handle support
591 HandleArea* handle_area() const { return _handle_area; }
592 void set_handle_area(HandleArea* area) { _handle_area = area; }
593
594 GrowableArray<Metadata*>* metadata_handles() const { return _metadata_handles; }
595 void set_metadata_handles(GrowableArray<Metadata*>* handles){ _metadata_handles = handles; }
596
597 // Thread-Local Allocation Buffer (TLAB) support
598 ThreadLocalAllocBuffer& tlab() { return _tlab; }
599 void initialize_tlab() {
600 if (UseTLAB) {
601 tlab().initialize();
602 }
603 }
604
605 jlong allocated_bytes() { return _allocated_bytes; }
606 void set_allocated_bytes(jlong value) { _allocated_bytes = value; }
607 void incr_allocated_bytes(jlong size) { _allocated_bytes += size; }
608 inline jlong cooked_allocated_bytes();
609
610 ThreadHeapSampler& heap_sampler() { return _heap_sampler; }
611
612 ThreadStatisticalInfo& statistical_info() { return _statistical_info; }
613
614 JFR_ONLY(DEFINE_THREAD_LOCAL_ACCESSOR_JFR;)
615
616 bool is_trace_suspend() { return (_suspend_flags & _trace_flag) != 0; }
617
618 // VM operation support
619 int vm_operation_ticket() { return ++_vm_operation_started_count; }
620 int vm_operation_completed_count() { return _vm_operation_completed_count; }
621 void increment_vm_operation_completed_count() { _vm_operation_completed_count++; }
622
623 // For tracking the heavyweight monitor the thread is pending on.
624 ObjectMonitor* current_pending_monitor() {
625 return _current_pending_monitor;
626 }
627 void set_current_pending_monitor(ObjectMonitor* monitor) {
628 _current_pending_monitor = monitor;
629 }
630 void set_current_pending_monitor_is_from_java(bool from_java) {
631 _current_pending_monitor_is_from_java = from_java;
632 }
633 bool current_pending_monitor_is_from_java() {
634 return _current_pending_monitor_is_from_java;
635 }
636
637 // For tracking the ObjectMonitor on which this thread called Object.wait()
638 ObjectMonitor* current_waiting_monitor() {
639 return _current_waiting_monitor;
640 }
641 void set_current_waiting_monitor(ObjectMonitor* monitor) {
642 _current_waiting_monitor = monitor;
643 }
644
645 // For tracking the Jvmti raw monitor the thread is pending on.
646 JvmtiRawMonitor* current_pending_raw_monitor() {
647 return _current_pending_raw_monitor;
648 }
649 void set_current_pending_raw_monitor(JvmtiRawMonitor* monitor) {
650 _current_pending_raw_monitor = monitor;
651 }
652
653 // GC support
654 // Apply "f->do_oop" to all root oops in "this".
655 // Used by JavaThread::oops_do.
656 // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames
657 virtual void oops_do(OopClosure* f, CodeBlobClosure* cf);
658
659 // Handles the parallel case for claim_threads_do.
660 private:
661 bool claim_par_threads_do(uintx claim_token);
662 public:
663 // Requires that "claim_token" is that of the current iteration.
664 // If "is_par" is false, sets the token of "this" to
665 // "claim_token", and returns "true". If "is_par" is true,
666 // uses an atomic instruction to set the current thread's token to
667 // "claim_token", if it is not already. Returns "true" iff the
668 // calling thread does the update, this indicates that the calling thread
669 // has claimed the thread in the current iteration.
670 bool claim_threads_do(bool is_par, uintx claim_token) {
671 if (!is_par) {
672 _threads_do_token = claim_token;
673 return true;
674 } else {
675 return claim_par_threads_do(claim_token);
676 }
677 }
678
679 uintx threads_do_token() const { return _threads_do_token; }
680
681 // jvmtiRedefineClasses support
682 void metadata_handles_do(void f(Metadata*));
683
684 private:
685 // Check if address is within the given range of this thread's
686 // stack: stack_base() > adr >/>= limit
687 // The check is inclusive of limit if passed true, else exclusive.
688 bool is_in_stack_range(address adr, address limit, bool inclusive) const {
689 assert(stack_base() > limit && limit >= stack_end(), "limit is outside of stack");
690 return stack_base() > adr && (inclusive ? adr >= limit : adr > limit);
691 }
692
693 public:
694 // Used by fast lock support
695 virtual bool is_lock_owned(address adr) const;
696
697 // Check if address is within the given range of this thread's
698 // stack: stack_base() > adr >= limit
699 bool is_in_stack_range_incl(address adr, address limit) const {
700 return is_in_stack_range(adr, limit, true);
701 }
702
703 // Check if address is within the given range of this thread's
704 // stack: stack_base() > adr > limit
705 bool is_in_stack_range_excl(address adr, address limit) const {
706 return is_in_stack_range(adr, limit, false);
707 }
708
709 // Check if address is in the stack mapped to this thread. Used mainly in
710 // error reporting (so has to include guard zone) and frame printing.
711 // Expects _stack_base to be initialized - checked with assert.
712 bool is_in_full_stack_checked(address adr) const {
713 return is_in_stack_range_incl(adr, stack_end());
714 }
715
716 // Like is_in_full_stack_checked but without the assertions as this
717 // may be called in a thread before _stack_base is initialized.
718 bool is_in_full_stack(address adr) const {
719 address stack_end = _stack_base - _stack_size;
720 return _stack_base > adr && adr >= stack_end;
721 }
722
723 // Check if address is in the live stack of this thread (not just for locks).
724 // Warning: can only be called by the current thread on itself.
725 bool is_in_live_stack(address adr) const {
726 assert(Thread::current() == this, "is_in_live_stack can only be called from current thread");
727 return is_in_stack_range_incl(adr, os::current_stack_pointer());
728 }
729
730 // Sets this thread as starting thread. Returns failure if thread
731 // creation fails due to lack of memory, too many threads etc.
732 bool set_as_starting_thread();
733
734 protected:
735 // OS data associated with the thread
736 OSThread* _osthread; // Platform-specific thread information
737
738 // Thread local resource area for temporary allocation within the VM
739 ResourceArea* _resource_area;
740
741 DEBUG_ONLY(ResourceMark* _current_resource_mark;)
742
743 // Thread local handle area for allocation of handles within the VM
744 HandleArea* _handle_area;
745 GrowableArray<Metadata*>* _metadata_handles;
746
747 // Support for stack overflow handling, get_thread, etc.
748 address _stack_base;
749 size_t _stack_size;
750 int _lgrp_id;
751
752 volatile void** polling_page_addr() { return &_polling_page; }
753
754 public:
755 // Stack overflow support
756 address stack_base() const { assert(_stack_base != NULL,"Sanity check"); return _stack_base; }
757 void set_stack_base(address base) { _stack_base = base; }
758 size_t stack_size() const { return _stack_size; }
759 void set_stack_size(size_t size) { _stack_size = size; }
760 address stack_end() const { return stack_base() - stack_size(); }
761 void record_stack_base_and_size();
762 void register_thread_stack_with_NMT() NOT_NMT_RETURN;
763
764 int lgrp_id() const { return _lgrp_id; }
765 void set_lgrp_id(int value) { _lgrp_id = value; }
766
767 // Printing
768 void print_on(outputStream* st, bool print_extended_info) const;
769 virtual void print_on(outputStream* st) const { print_on(st, false); }
770 void print() const;
771 virtual void print_on_error(outputStream* st, char* buf, int buflen) const;
772 void print_value_on(outputStream* st) const;
773
774 // Debug-only code
775 #ifdef ASSERT
776 private:
777 // Deadlock detection support for Mutex locks. List of locks own by thread.
778 Mutex* _owned_locks;
779 // Mutex::set_owner_implementation is the only place where _owned_locks is modified,
780 // thus the friendship
781 friend class Mutex;
782 friend class Monitor;
783
784 public:
785 void print_owned_locks_on(outputStream* st) const;
786 void print_owned_locks() const { print_owned_locks_on(tty); }
787 Mutex* owned_locks() const { return _owned_locks; }
788 bool owns_locks() const { return owned_locks() != NULL; }
789
790 // Deadlock detection
791 ResourceMark* current_resource_mark() { return _current_resource_mark; }
792 void set_current_resource_mark(ResourceMark* rm) { _current_resource_mark = rm; }
793 #endif // ASSERT
794
795 // These functions check conditions on a JavaThread before possibly going to a safepoint,
796 // including NoSafepointVerifier.
797 void check_for_valid_safepoint_state() NOT_DEBUG_RETURN;
798 void check_possible_safepoint() NOT_DEBUG_RETURN;
799
800 private:
801 volatile int _jvmti_env_iteration_count;
802
803 public:
804 void entering_jvmti_env_iteration() { ++_jvmti_env_iteration_count; }
805 void leaving_jvmti_env_iteration() { --_jvmti_env_iteration_count; }
806 bool is_inside_jvmti_env_iteration() { return _jvmti_env_iteration_count > 0; }
807
808 // Code generation
809 static ByteSize exception_file_offset() { return byte_offset_of(Thread, _exception_file); }
810 static ByteSize exception_line_offset() { return byte_offset_of(Thread, _exception_line); }
811 static ByteSize active_handles_offset() { return byte_offset_of(Thread, _active_handles); }
812
813 static ByteSize stack_base_offset() { return byte_offset_of(Thread, _stack_base); }
814 static ByteSize stack_size_offset() { return byte_offset_of(Thread, _stack_size); }
815
816 static ByteSize polling_page_offset() { return byte_offset_of(Thread, _polling_page); }
817
818 static ByteSize tlab_start_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::start_offset(); }
819 static ByteSize tlab_end_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::end_offset(); }
820 static ByteSize tlab_top_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::top_offset(); }
821 static ByteSize tlab_pf_top_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::pf_top_offset(); }
822
823 static ByteSize allocated_bytes_offset() { return byte_offset_of(Thread, _allocated_bytes); }
824
825 JFR_ONLY(DEFINE_THREAD_LOCAL_OFFSET_JFR;)
826
827 public:
828 volatile intptr_t _Stalled;
829 volatile int _TypeTag;
830 ParkEvent * _ParkEvent; // for Object monitors and JVMTI raw monitors
831 ParkEvent * _MuxEvent; // for low-level muxAcquire-muxRelease
832 int NativeSyncRecursion; // diagnostic
833
834 volatile int _OnTrap; // Resume-at IP delta
835 jint _hashStateW; // Marsaglia Shift-XOR thread-local RNG
836 jint _hashStateX; // thread-specific hashCode generator state
837 jint _hashStateY;
838 jint _hashStateZ;
839
840 // Low-level leaf-lock primitives used to implement synchronization
841 // and native monitor-mutex infrastructure.
842 // Not for general synchronization use.
843 static void SpinAcquire(volatile int * Lock, const char * Name);
844 static void SpinRelease(volatile int * Lock);
845 static void muxAcquire(volatile intptr_t * Lock, const char * Name);
846 static void muxRelease(volatile intptr_t * Lock);
847 };
848
849 // Inline implementation of Thread::current()
850 inline Thread* Thread::current() {
851 Thread* current = current_or_null();
852 assert(current != NULL, "Thread::current() called on detached thread");
853 return current;
854 }
855
856 inline Thread* Thread::current_or_null() {
857 #ifndef USE_LIBRARY_BASED_TLS_ONLY
858 return _thr_current;
859 #else
860 if (ThreadLocalStorage::is_initialized()) {
861 return ThreadLocalStorage::thread();
862 }
863 return NULL;
864 #endif
865 }
866
867 inline Thread* Thread::current_or_null_safe() {
868 if (ThreadLocalStorage::is_initialized()) {
869 return ThreadLocalStorage::thread();
870 }
871 return NULL;
872 }
873
874 class NonJavaThread: public Thread {
875 friend class VMStructs;
876
877 NonJavaThread* volatile _next;
878
879 class List;
880 static List _the_list;
881
882 void add_to_the_list();
883 void remove_from_the_list();
884
885 protected:
886 virtual void pre_run();
887 virtual void post_run();
888
889 public:
890 NonJavaThread();
891 ~NonJavaThread();
892
893 class Iterator;
894 };
895
896 // Provides iteration over the list of NonJavaThreads.
897 // List addition occurs in pre_run(), and removal occurs in post_run(),
898 // so that only live fully-initialized threads can be found in the list.
899 // Threads created after an iterator is constructed will not be visited
900 // by the iterator. The scope of an iterator is a critical section; there
901 // must be no safepoint checks in that scope.
902 class NonJavaThread::Iterator : public StackObj {
903 uint _protect_enter;
904 NonJavaThread* _current;
905
906 NONCOPYABLE(Iterator);
907
908 public:
909 Iterator();
910 ~Iterator();
911
912 bool end() const { return _current == NULL; }
913 NonJavaThread* current() const { return _current; }
914 void step();
915 };
916
917 // Name support for threads. non-JavaThread subclasses with multiple
918 // uniquely named instances should derive from this.
919 class NamedThread: public NonJavaThread {
920 friend class VMStructs;
921 enum {
922 max_name_len = 64
923 };
924 private:
925 char* _name;
926 // log JavaThread being processed by oops_do
927 JavaThread* _processed_thread;
928 uint _gc_id; // The current GC id when a thread takes part in GC
929
930 public:
931 NamedThread();
932 ~NamedThread();
933 // May only be called once per thread.
934 void set_name(const char* format, ...) ATTRIBUTE_PRINTF(2, 3);
935 virtual bool is_Named_thread() const { return true; }
936 virtual char* name() const { return _name == NULL ? (char*)"Unknown Thread" : _name; }
937 JavaThread *processed_thread() { return _processed_thread; }
938 void set_processed_thread(JavaThread *thread) { _processed_thread = thread; }
939 virtual void print_on(outputStream* st) const;
940
941 void set_gc_id(uint gc_id) { _gc_id = gc_id; }
942 uint gc_id() { return _gc_id; }
943 };
944
945 // Worker threads are named and have an id of an assigned work.
946 class WorkerThread: public NamedThread {
947 private:
948 uint _id;
949 public:
950 WorkerThread() : _id(0) { }
951 virtual bool is_Worker_thread() const { return true; }
952
953 virtual WorkerThread* as_Worker_thread() const {
954 assert(is_Worker_thread(), "Dubious cast to WorkerThread*?");
955 return (WorkerThread*) this;
956 }
957
958 void set_id(uint work_id) { _id = work_id; }
959 uint id() const { return _id; }
960 };
961
962 // A single WatcherThread is used for simulating timer interrupts.
963 class WatcherThread: public NonJavaThread {
964 friend class VMStructs;
965 protected:
966 virtual void run();
967
968 private:
969 static WatcherThread* _watcher_thread;
970
971 static bool _startable;
972 // volatile due to at least one lock-free read
973 volatile static bool _should_terminate;
974 public:
975 enum SomeConstants {
976 delay_interval = 10 // interrupt delay in milliseconds
977 };
978
979 // Constructor
980 WatcherThread();
981
982 // No destruction allowed
983 ~WatcherThread() {
984 guarantee(false, "WatcherThread deletion must fix the race with VM termination");
985 }
986
987 // Tester
988 bool is_Watcher_thread() const { return true; }
989
990 // Printing
991 char* name() const { return (char*)"VM Periodic Task Thread"; }
992 void print_on(outputStream* st) const;
993 void unpark();
994
995 // Returns the single instance of WatcherThread
996 static WatcherThread* watcher_thread() { return _watcher_thread; }
997
998 // Create and start the single instance of WatcherThread, or stop it on shutdown
999 static void start();
1000 static void stop();
1001 // Only allow start once the VM is sufficiently initialized
1002 // Otherwise the first task to enroll will trigger the start
1003 static void make_startable();
1004 private:
1005 int sleep() const;
1006 };
1007
1008
1009 class CompilerThread;
1010
1011 typedef void (*ThreadFunction)(JavaThread*, TRAPS);
1012
1013 class JavaThread: public Thread {
1014 friend class VMStructs;
1015 friend class JVMCIVMStructs;
1016 friend class WhiteBox;
1017 friend class ThreadsSMRSupport; // to access _threadObj for exiting_threads_oops_do
1018 private:
1019 bool _on_thread_list; // Is set when this JavaThread is added to the Threads list
1020 oop _threadObj; // The Java level thread object
1021
1022 #ifdef ASSERT
1023 private:
1024 int _java_call_counter;
1025
1026 public:
1027 int java_call_counter() { return _java_call_counter; }
1028 void inc_java_call_counter() { _java_call_counter++; }
1029 void dec_java_call_counter() {
1030 assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
1031 _java_call_counter--;
1032 }
1033 private: // restore original namespace restriction
1034 #endif // ifdef ASSERT
1035
1036 #ifndef PRODUCT
1037 public:
1038 enum {
1039 jump_ring_buffer_size = 16
1040 };
1041 private: // restore original namespace restriction
1042 #endif
1043
1044 JavaFrameAnchor _anchor; // Encapsulation of current java frame and it state
1045
1046 ThreadFunction _entry_point;
1047
1048 JNIEnv _jni_environment;
1049
1050 // Deopt support
1051 DeoptResourceMark* _deopt_mark; // Holds special ResourceMark for deoptimization
1052
1053 CompiledMethod* _deopt_nmethod; // CompiledMethod that is currently being deoptimized
1054 vframeArray* _vframe_array_head; // Holds the heap of the active vframeArrays
1055 vframeArray* _vframe_array_last; // Holds last vFrameArray we popped
1056 // Because deoptimization is lazy we must save jvmti requests to set locals
1057 // in compiled frames until we deoptimize and we have an interpreter frame.
1058 // This holds the pointer to array (yeah like there might be more than one) of
1059 // description of compiled vframes that have locals that need to be updated.
1060 GrowableArray<jvmtiDeferredLocalVariableSet*>* _deferred_locals_updates;
1061
1062 // Handshake value for fixing 6243940. We need a place for the i2c
1063 // adapter to store the callee Method*. This value is NEVER live
1064 // across a gc point so it does NOT have to be gc'd
1065 // The handshake is open ended since we can't be certain that it will
1066 // be NULLed. This is because we rarely ever see the race and end up
1067 // in handle_wrong_method which is the backend of the handshake. See
1068 // code in i2c adapters and handle_wrong_method.
1069
1070 Method* _callee_target;
1071
1072 // Used to pass back results to the interpreter or generated code running Java code.
1073 oop _vm_result; // oop result is GC-preserved
1074 Metadata* _vm_result_2; // non-oop result
1075
1076 // See ReduceInitialCardMarks: this holds the precise space interval of
1077 // the most recent slow path allocation for which compiled code has
1078 // elided card-marks for performance along the fast-path.
1079 MemRegion _deferred_card_mark;
1080
1081 MonitorChunk* _monitor_chunks; // Contains the off stack monitors
1082 // allocated during deoptimization
1083 // and by JNI_MonitorEnter/Exit
1084
1085 // Async. requests support
1086 enum AsyncRequests {
1087 _no_async_condition = 0,
1088 _async_exception,
1089 _async_unsafe_access_error
1090 };
1091 AsyncRequests _special_runtime_exit_condition; // Enum indicating pending async. request
1092 oop _pending_async_exception;
1093
1094 // Safepoint support
1095 public: // Expose _thread_state for SafeFetchInt()
1096 volatile JavaThreadState _thread_state;
1097 private:
1098 ThreadSafepointState* _safepoint_state; // Holds information about a thread during a safepoint
1099 address _saved_exception_pc; // Saved pc of instruction where last implicit exception happened
1100
1101 // JavaThread termination support
1102 enum TerminatedTypes {
1103 _not_terminated = 0xDEAD - 2,
1104 _thread_exiting, // JavaThread::exit() has been called for this thread
1105 _thread_terminated, // JavaThread is removed from thread list
1106 _vm_exited // JavaThread is still executing native code, but VM is terminated
1107 // only VM_Exit can set _vm_exited
1108 };
1109
1110 // In general a JavaThread's _terminated field transitions as follows:
1111 //
1112 // _not_terminated => _thread_exiting => _thread_terminated
1113 //
1114 // _vm_exited is a special value to cover the case of a JavaThread
1115 // executing native code after the VM itself is terminated.
1116 volatile TerminatedTypes _terminated;
1117 // suspend/resume support
1118 volatile bool _suspend_equivalent; // Suspend equivalent condition
1119 jint _in_deopt_handler; // count of deoptimization
1120 // handlers thread is in
1121 volatile bool _doing_unsafe_access; // Thread may fault due to unsafe access
1122 bool _do_not_unlock_if_synchronized; // Do not unlock the receiver of a synchronized method (since it was
1123 // never locked) when throwing an exception. Used by interpreter only.
1124
1125 // JNI attach states:
1126 enum JNIAttachStates {
1127 _not_attaching_via_jni = 1, // thread is not attaching via JNI
1128 _attaching_via_jni, // thread is attaching via JNI
1129 _attached_via_jni // thread has attached via JNI
1130 };
1131
1132 // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
1133 // A native thread that is attaching via JNI starts with a value
1134 // of _attaching_via_jni and transitions to _attached_via_jni.
1135 volatile JNIAttachStates _jni_attach_state;
1136
1137 public:
1138 // State of the stack guard pages for this thread.
1139 enum StackGuardState {
1140 stack_guard_unused, // not needed
1141 stack_guard_reserved_disabled,
1142 stack_guard_yellow_reserved_disabled,// disabled (temporarily) after stack overflow
1143 stack_guard_enabled // enabled
1144 };
1145
1146 private:
1147
1148 #if INCLUDE_JVMCI
1149 // The _pending_* fields below are used to communicate extra information
1150 // from an uncommon trap in JVMCI compiled code to the uncommon trap handler.
1151
1152 // Communicates the DeoptReason and DeoptAction of the uncommon trap
1153 int _pending_deoptimization;
1154
1155 // Specifies whether the uncommon trap is to bci 0 of a synchronized method
1156 // before the monitor has been acquired.
1157 bool _pending_monitorenter;
1158
1159 // Specifies if the DeoptReason for the last uncommon trap was Reason_transfer_to_interpreter
1160 bool _pending_transfer_to_interpreter;
1161
1162 // True if in a runtime call from compiled code that will deoptimize
1163 // and re-execute a failed heap allocation in the interpreter.
1164 bool _in_retryable_allocation;
1165
1166 // An id of a speculation that JVMCI compiled code can use to further describe and
1167 // uniquely identify the speculative optimization guarded by the uncommon trap
1168 jlong _pending_failed_speculation;
1169
1170 // These fields are mutually exclusive in terms of live ranges.
1171 union {
1172 // Communicates the pc at which the most recent implicit exception occurred
1173 // from the signal handler to a deoptimization stub.
1174 address _implicit_exception_pc;
1175
1176 // Communicates an alternative call target to an i2c stub from a JavaCall .
1177 address _alternate_call_target;
1178 } _jvmci;
1179
1180 // Support for high precision, thread sensitive counters in JVMCI compiled code.
1181 jlong* _jvmci_counters;
1182
1183 public:
1184 static jlong* _jvmci_old_thread_counters;
1185 static void collect_counters(jlong* array, int length);
1186 void resize_counters(int current_size, int new_size);
1187 static void resize_all_jvmci_counters(int new_size);
1188
1189 private:
1190 #endif // INCLUDE_JVMCI
1191
1192 StackGuardState _stack_guard_state;
1193
1194 // Precompute the limit of the stack as used in stack overflow checks.
1195 // We load it from here to simplify the stack overflow check in assembly.
1196 address _stack_overflow_limit;
1197 address _reserved_stack_activation;
1198
1199 // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
1200 // used to temp. parsing values into and out of the runtime system during exception handling for compiled
1201 // code)
1202 volatile oop _exception_oop; // Exception thrown in compiled code
1203 volatile address _exception_pc; // PC where exception happened
1204 volatile address _exception_handler_pc; // PC for handler of exception
1205 volatile int _is_method_handle_return; // true (== 1) if the current exception PC is a MethodHandle call site.
1206
1207 private:
1208 // support for JNI critical regions
1209 jint _jni_active_critical; // count of entries into JNI critical region
1210
1211 // Checked JNI: function name requires exception check
1212 char* _pending_jni_exception_check_fn;
1213
1214 // For deadlock detection.
1215 int _depth_first_number;
1216
1217 // JVMTI PopFrame support
1218 // This is set to popframe_pending to signal that top Java frame should be popped immediately
1219 int _popframe_condition;
1220
1221 // If reallocation of scalar replaced objects fails, we throw OOM
1222 // and during exception propagation, pop the top
1223 // _frames_to_pop_failed_realloc frames, the ones that reference
1224 // failed reallocations.
1225 int _frames_to_pop_failed_realloc;
1226
1227 friend class VMThread;
1228 friend class ThreadWaitTransition;
1229 friend class VM_Exit;
1230
1231 void initialize(); // Initialized the instance variables
1232
1233 public:
1234 // Constructor
1235 JavaThread(bool is_attaching_via_jni = false); // for main thread and JNI attached threads
1236 JavaThread(ThreadFunction entry_point, size_t stack_size = 0);
1237 ~JavaThread();
1238
1239 #ifdef ASSERT
1240 // verify this JavaThread hasn't be published in the Threads::list yet
1241 void verify_not_published();
1242 #endif // ASSERT
1243
1244 //JNI functiontable getter/setter for JVMTI jni function table interception API.
1245 void set_jni_functions(struct JNINativeInterface_* functionTable) {
1246 _jni_environment.functions = functionTable;
1247 }
1248 struct JNINativeInterface_* get_jni_functions() {
1249 return (struct JNINativeInterface_ *)_jni_environment.functions;
1250 }
1251
1252 // This function is called at thread creation to allow
1253 // platform specific thread variables to be initialized.
1254 void cache_global_variables();
1255
1256 // Executes Shutdown.shutdown()
1257 void invoke_shutdown_hooks();
1258
1259 // Cleanup on thread exit
1260 enum ExitType {
1261 normal_exit,
1262 jni_detach
1263 };
1264 void exit(bool destroy_vm, ExitType exit_type = normal_exit);
1265
1266 void cleanup_failed_attach_current_thread(bool is_daemon);
1267
1268 // Testers
1269 virtual bool is_Java_thread() const { return true; }
1270 virtual bool can_call_java() const { return true; }
1271
1272 virtual bool is_active_Java_thread() const {
1273 return on_thread_list() && !is_terminated();
1274 }
1275
1276 // Thread oop. threadObj() can be NULL for initial JavaThread
1277 // (or for threads attached via JNI)
1278 oop threadObj() const { return _threadObj; }
1279 void set_threadObj(oop p) { _threadObj = p; }
1280
1281 // Prepare thread and add to priority queue. If a priority is
1282 // not specified, use the priority of the thread object. Threads_lock
1283 // must be held while this function is called.
1284 void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
1285
1286 void set_saved_exception_pc(address pc) { _saved_exception_pc = pc; }
1287 address saved_exception_pc() { return _saved_exception_pc; }
1288
1289
1290 ThreadFunction entry_point() const { return _entry_point; }
1291
1292 // Allocates a new Java level thread object for this thread. thread_name may be NULL.
1293 void allocate_threadObj(Handle thread_group, const char* thread_name, bool daemon, TRAPS);
1294
1295 // Last frame anchor routines
1296
1297 JavaFrameAnchor* frame_anchor(void) { return &_anchor; }
1298
1299 // last_Java_sp
1300 bool has_last_Java_frame() const { return _anchor.has_last_Java_frame(); }
1301 intptr_t* last_Java_sp() const { return _anchor.last_Java_sp(); }
1302
1303 // last_Java_pc
1304
1305 address last_Java_pc(void) { return _anchor.last_Java_pc(); }
1306
1307 // Safepoint support
1308 inline JavaThreadState thread_state() const;
1309 inline void set_thread_state(JavaThreadState s);
1310 inline void set_thread_state_fence(JavaThreadState s); // fence after setting thread state
1311 inline ThreadSafepointState* safepoint_state() const;
1312 inline void set_safepoint_state(ThreadSafepointState* state);
1313 inline bool is_at_poll_safepoint();
1314
1315 // JavaThread termination and lifecycle support:
1316 void smr_delete();
1317 bool on_thread_list() const { return _on_thread_list; }
1318 void set_on_thread_list() { _on_thread_list = true; }
1319
1320 // thread has called JavaThread::exit() or is terminated
1321 bool is_exiting() const;
1322 // thread is terminated (no longer on the threads list); we compare
1323 // against the two non-terminated values so that a freed JavaThread
1324 // will also be considered terminated.
1325 bool check_is_terminated(TerminatedTypes l_terminated) const {
1326 return l_terminated != _not_terminated && l_terminated != _thread_exiting;
1327 }
1328 bool is_terminated() const;
1329 void set_terminated(TerminatedTypes t);
1330 // special for Threads::remove() which is static:
1331 void set_terminated_value();
1332 void block_if_vm_exited();
1333
1334 bool doing_unsafe_access() { return _doing_unsafe_access; }
1335 void set_doing_unsafe_access(bool val) { _doing_unsafe_access = val; }
1336
1337 bool do_not_unlock_if_synchronized() { return _do_not_unlock_if_synchronized; }
1338 void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
1339
1340 inline void set_polling_page_release(void* poll_value);
1341 inline void set_polling_page(void* poll_value);
1342 inline volatile void* get_polling_page();
1343
1344 private:
1345 // Support for thread handshake operations
1346 HandshakeState _handshake;
1347 public:
1348 void set_handshake_operation(HandshakeOperation* op) {
1349 _handshake.set_operation(op);
1350 }
1351
1352 bool has_handshake() const {
1353 return _handshake.has_operation();
1354 }
1355
1356 void handshake_process_by_self() {
1357 _handshake.process_by_self();
1358 }
1359
1360 HandshakeState::ProcessResult handshake_try_process(HandshakeOperation* op) {
1361 return _handshake.try_process(op);
1362 }
1363
1364 #ifdef ASSERT
1365 Thread* active_handshaker() const {
1366 return _handshake.active_handshaker();
1367 }
1368 #endif
1369
1370 // Suspend/resume support for JavaThread
1371 private:
1372 inline void set_ext_suspended();
1373 inline void clear_ext_suspended();
1374
1375 public:
1376 void java_suspend(); // higher-level suspension logic called by the public APIs
1377 void java_resume(); // higher-level resume logic called by the public APIs
1378 int java_suspend_self(); // low-level self-suspension mechanics
1379
1380 private:
1381 // mid-level wrapper around java_suspend_self to set up correct state and
1382 // check for a pending safepoint at the end
1383 void java_suspend_self_with_safepoint_check();
1384
1385 public:
1386 void check_and_wait_while_suspended() {
1387 assert(JavaThread::current() == this, "sanity check");
1388
1389 bool do_self_suspend;
1390 do {
1391 // were we externally suspended while we were waiting?
1392 do_self_suspend = handle_special_suspend_equivalent_condition();
1393 if (do_self_suspend) {
1394 // don't surprise the thread that suspended us by returning
1395 java_suspend_self();
1396 set_suspend_equivalent();
1397 }
1398 } while (do_self_suspend);
1399 }
1400 static void check_safepoint_and_suspend_for_native_trans(JavaThread *thread);
1401 // Check for async exception in addition to safepoint and suspend request.
1402 static void check_special_condition_for_native_trans(JavaThread *thread);
1403
1404 // Same as check_special_condition_for_native_trans but finishes the
1405 // transition into thread_in_Java mode so that it can potentially
1406 // block.
1407 static void check_special_condition_for_native_trans_and_transition(JavaThread *thread);
1408
1409 bool is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits);
1410 bool is_ext_suspend_completed_with_lock(uint32_t *bits) {
1411 MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1412 // Warning: is_ext_suspend_completed() may temporarily drop the
1413 // SR_lock to allow the thread to reach a stable thread state if
1414 // it is currently in a transient thread state.
1415 return is_ext_suspend_completed(false /* !called_by_wait */,
1416 SuspendRetryDelay, bits);
1417 }
1418
1419 // We cannot allow wait_for_ext_suspend_completion() to run forever or
1420 // we could hang. SuspendRetryCount and SuspendRetryDelay are normally
1421 // passed as the count and delay parameters. Experiments with specific
1422 // calls to wait_for_ext_suspend_completion() can be done by passing
1423 // other values in the code. Experiments with all calls can be done
1424 // via the appropriate -XX options.
1425 bool wait_for_ext_suspend_completion(int count, int delay, uint32_t *bits);
1426
1427 // test for suspend - most (all?) of these should go away
1428 bool is_thread_fully_suspended(bool wait_for_suspend, uint32_t *bits);
1429
1430 inline void set_external_suspend();
1431 inline void clear_external_suspend();
1432
1433 bool is_external_suspend() const {
1434 return (_suspend_flags & _external_suspend) != 0;
1435 }
1436 // Whenever a thread transitions from native to vm/java it must suspend
1437 // if external|deopt suspend is present.
1438 bool is_suspend_after_native() const {
1439 return (_suspend_flags & (_external_suspend JFR_ONLY(| _trace_flag))) != 0;
1440 }
1441
1442 // external suspend request is completed
1443 bool is_ext_suspended() const {
1444 return (_suspend_flags & _ext_suspended) != 0;
1445 }
1446
1447 bool is_external_suspend_with_lock() const {
1448 MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1449 return is_external_suspend();
1450 }
1451
1452 // Special method to handle a pending external suspend request
1453 // when a suspend equivalent condition lifts.
1454 bool handle_special_suspend_equivalent_condition() {
1455 assert(is_suspend_equivalent(),
1456 "should only be called in a suspend equivalence condition");
1457 MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1458 bool ret = is_external_suspend();
1459 if (!ret) {
1460 // not about to self-suspend so clear suspend equivalence
1461 clear_suspend_equivalent();
1462 }
1463 // implied else:
1464 // We have a pending external suspend request so we leave the
1465 // suspend_equivalent flag set until java_suspend_self() sets
1466 // the ext_suspended flag and clears the suspend_equivalent
1467 // flag. This insures that wait_for_ext_suspend_completion()
1468 // will return consistent values.
1469 return ret;
1470 }
1471
1472 // utility methods to see if we are doing some kind of suspension
1473 bool is_being_ext_suspended() const {
1474 MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1475 return is_ext_suspended() || is_external_suspend();
1476 }
1477
1478 bool is_suspend_equivalent() const { return _suspend_equivalent; }
1479
1480 void set_suspend_equivalent() { _suspend_equivalent = true; }
1481 void clear_suspend_equivalent() { _suspend_equivalent = false; }
1482
1483 // Thread.stop support
1484 void send_thread_stop(oop throwable);
1485 AsyncRequests clear_special_runtime_exit_condition() {
1486 AsyncRequests x = _special_runtime_exit_condition;
1487 _special_runtime_exit_condition = _no_async_condition;
1488 return x;
1489 }
1490
1491 // Are any async conditions present?
1492 bool has_async_condition() { return (_special_runtime_exit_condition != _no_async_condition); }
1493
1494 void check_and_handle_async_exceptions(bool check_unsafe_error = true);
1495
1496 // these next two are also used for self-suspension and async exception support
1497 void handle_special_runtime_exit_condition(bool check_asyncs = true);
1498
1499 // Return true if JavaThread has an asynchronous condition or
1500 // if external suspension is requested.
1501 bool has_special_runtime_exit_condition() {
1502 // Because we don't use is_external_suspend_with_lock
1503 // it is possible that we won't see an asynchronous external suspend
1504 // request that has just gotten started, i.e., SR_lock grabbed but
1505 // _external_suspend field change either not made yet or not visible
1506 // yet. However, this is okay because the request is asynchronous and
1507 // we will see the new flag value the next time through. It's also
1508 // possible that the external suspend request is dropped after
1509 // we have checked is_external_suspend(), we will recheck its value
1510 // under SR_lock in java_suspend_self().
1511 return (_special_runtime_exit_condition != _no_async_condition) ||
1512 is_external_suspend() || is_trace_suspend();
1513 }
1514
1515 void set_pending_unsafe_access_error() { _special_runtime_exit_condition = _async_unsafe_access_error; }
1516
1517 inline void set_pending_async_exception(oop e);
1518
1519 // Fast-locking support
1520 bool is_lock_owned(address adr) const;
1521
1522 // Accessors for vframe array top
1523 // The linked list of vframe arrays are sorted on sp. This means when we
1524 // unpack the head must contain the vframe array to unpack.
1525 void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
1526 vframeArray* vframe_array_head() const { return _vframe_array_head; }
1527
1528 // Side structure for deferring update of java frame locals until deopt occurs
1529 GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred_locals() const { return _deferred_locals_updates; }
1530 void set_deferred_locals(GrowableArray<jvmtiDeferredLocalVariableSet *>* vf) { _deferred_locals_updates = vf; }
1531
1532 // These only really exist to make debugging deopt problems simpler
1533
1534 void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
1535 vframeArray* vframe_array_last() const { return _vframe_array_last; }
1536
1537 // The special resourceMark used during deoptimization
1538
1539 void set_deopt_mark(DeoptResourceMark* value) { _deopt_mark = value; }
1540 DeoptResourceMark* deopt_mark(void) { return _deopt_mark; }
1541
1542 void set_deopt_compiled_method(CompiledMethod* nm) { _deopt_nmethod = nm; }
1543 CompiledMethod* deopt_compiled_method() { return _deopt_nmethod; }
1544
1545 Method* callee_target() const { return _callee_target; }
1546 void set_callee_target (Method* x) { _callee_target = x; }
1547
1548 // Oop results of vm runtime calls
1549 oop vm_result() const { return _vm_result; }
1550 void set_vm_result (oop x) { _vm_result = x; }
1551
1552 Metadata* vm_result_2() const { return _vm_result_2; }
1553 void set_vm_result_2 (Metadata* x) { _vm_result_2 = x; }
1554
1555 MemRegion deferred_card_mark() const { return _deferred_card_mark; }
1556 void set_deferred_card_mark(MemRegion mr) { _deferred_card_mark = mr; }
1557
1558 #if INCLUDE_JVMCI
1559 int pending_deoptimization() const { return _pending_deoptimization; }
1560 jlong pending_failed_speculation() const { return _pending_failed_speculation; }
1561 bool has_pending_monitorenter() const { return _pending_monitorenter; }
1562 void set_pending_monitorenter(bool b) { _pending_monitorenter = b; }
1563 void set_pending_deoptimization(int reason) { _pending_deoptimization = reason; }
1564 void set_pending_failed_speculation(jlong failed_speculation) { _pending_failed_speculation = failed_speculation; }
1565 void set_pending_transfer_to_interpreter(bool b) { _pending_transfer_to_interpreter = b; }
1566 void set_jvmci_alternate_call_target(address a) { assert(_jvmci._alternate_call_target == NULL, "must be"); _jvmci._alternate_call_target = a; }
1567 void set_jvmci_implicit_exception_pc(address a) { assert(_jvmci._implicit_exception_pc == NULL, "must be"); _jvmci._implicit_exception_pc = a; }
1568
1569 virtual bool in_retryable_allocation() const { return _in_retryable_allocation; }
1570 void set_in_retryable_allocation(bool b) { _in_retryable_allocation = b; }
1571 #endif // INCLUDE_JVMCI
1572
1573 // Exception handling for compiled methods
1574 oop exception_oop() const;
1575 address exception_pc() const { return _exception_pc; }
1576 address exception_handler_pc() const { return _exception_handler_pc; }
1577 bool is_method_handle_return() const { return _is_method_handle_return == 1; }
1578
1579 void set_exception_oop(oop o);
1580 void set_exception_pc(address a) { _exception_pc = a; }
1581 void set_exception_handler_pc(address a) { _exception_handler_pc = a; }
1582 void set_is_method_handle_return(bool value) { _is_method_handle_return = value ? 1 : 0; }
1583
1584 void clear_exception_oop_and_pc() {
1585 set_exception_oop(NULL);
1586 set_exception_pc(NULL);
1587 }
1588
1589 // Stack overflow support
1590 //
1591 // (small addresses)
1592 //
1593 // -- <-- stack_end() ---
1594 // | |
1595 // | red pages |
1596 // | |
1597 // -- <-- stack_red_zone_base() |
1598 // | |
1599 // | guard
1600 // | yellow pages zone
1601 // | |
1602 // | |
1603 // -- <-- stack_yellow_zone_base() |
1604 // | |
1605 // | |
1606 // | reserved pages |
1607 // | |
1608 // -- <-- stack_reserved_zone_base() --- ---
1609 // /|\ shadow <-- stack_overflow_limit() (somewhere in here)
1610 // | zone
1611 // \|/ size
1612 // some untouched memory ---
1613 //
1614 //
1615 // --
1616 // |
1617 // | shadow zone
1618 // |
1619 // --
1620 // x frame n
1621 // --
1622 // x frame n-1
1623 // x
1624 // --
1625 // ...
1626 //
1627 // --
1628 // x frame 0
1629 // -- <-- stack_base()
1630 //
1631 // (large addresses)
1632 //
1633
1634 private:
1635 // These values are derived from flags StackRedPages, StackYellowPages,
1636 // StackReservedPages and StackShadowPages. The zone size is determined
1637 // ergonomically if page_size > 4K.
1638 static size_t _stack_red_zone_size;
1639 static size_t _stack_yellow_zone_size;
1640 static size_t _stack_reserved_zone_size;
1641 static size_t _stack_shadow_zone_size;
1642 public:
1643 inline size_t stack_available(address cur_sp);
1644
1645 static size_t stack_red_zone_size() {
1646 assert(_stack_red_zone_size > 0, "Don't call this before the field is initialized.");
1647 return _stack_red_zone_size;
1648 }
1649 static void set_stack_red_zone_size(size_t s) {
1650 assert(is_aligned(s, os::vm_page_size()),
1651 "We can not protect if the red zone size is not page aligned.");
1652 assert(_stack_red_zone_size == 0, "This should be called only once.");
1653 _stack_red_zone_size = s;
1654 }
1655 address stack_red_zone_base() {
1656 return (address)(stack_end() + stack_red_zone_size());
1657 }
1658 bool in_stack_red_zone(address a) {
1659 return a <= stack_red_zone_base() && a >= stack_end();
1660 }
1661
1662 static size_t stack_yellow_zone_size() {
1663 assert(_stack_yellow_zone_size > 0, "Don't call this before the field is initialized.");
1664 return _stack_yellow_zone_size;
1665 }
1666 static void set_stack_yellow_zone_size(size_t s) {
1667 assert(is_aligned(s, os::vm_page_size()),
1668 "We can not protect if the yellow zone size is not page aligned.");
1669 assert(_stack_yellow_zone_size == 0, "This should be called only once.");
1670 _stack_yellow_zone_size = s;
1671 }
1672
1673 static size_t stack_reserved_zone_size() {
1674 // _stack_reserved_zone_size may be 0. This indicates the feature is off.
1675 return _stack_reserved_zone_size;
1676 }
1677 static void set_stack_reserved_zone_size(size_t s) {
1678 assert(is_aligned(s, os::vm_page_size()),
1679 "We can not protect if the reserved zone size is not page aligned.");
1680 assert(_stack_reserved_zone_size == 0, "This should be called only once.");
1681 _stack_reserved_zone_size = s;
1682 }
1683 address stack_reserved_zone_base() const {
1684 return (address)(stack_end() +
1685 (stack_red_zone_size() + stack_yellow_zone_size() + stack_reserved_zone_size()));
1686 }
1687 bool in_stack_reserved_zone(address a) {
1688 return (a <= stack_reserved_zone_base()) &&
1689 (a >= (address)((intptr_t)stack_reserved_zone_base() - stack_reserved_zone_size()));
1690 }
1691
1692 static size_t stack_yellow_reserved_zone_size() {
1693 return _stack_yellow_zone_size + _stack_reserved_zone_size;
1694 }
1695 bool in_stack_yellow_reserved_zone(address a) {
1696 return (a <= stack_reserved_zone_base()) && (a >= stack_red_zone_base());
1697 }
1698
1699 // Size of red + yellow + reserved zones.
1700 static size_t stack_guard_zone_size() {
1701 return stack_red_zone_size() + stack_yellow_reserved_zone_size();
1702 }
1703
1704 static size_t stack_shadow_zone_size() {
1705 assert(_stack_shadow_zone_size > 0, "Don't call this before the field is initialized.");
1706 return _stack_shadow_zone_size;
1707 }
1708 static void set_stack_shadow_zone_size(size_t s) {
1709 // The shadow area is not allocated or protected, so
1710 // it needs not be page aligned.
1711 // But the stack bang currently assumes that it is a
1712 // multiple of page size. This guarantees that the bang
1713 // loop touches all pages in the shadow zone.
1714 // This can be guaranteed differently, as well. E.g., if
1715 // the page size is a multiple of 4K, banging in 4K steps
1716 // suffices to touch all pages. (Some pages are banged
1717 // several times, though.)
1718 assert(is_aligned(s, os::vm_page_size()),
1719 "Stack bang assumes multiple of page size.");
1720 assert(_stack_shadow_zone_size == 0, "This should be called only once.");
1721 _stack_shadow_zone_size = s;
1722 }
1723
1724 void create_stack_guard_pages();
1725 void remove_stack_guard_pages();
1726
1727 void enable_stack_reserved_zone();
1728 void disable_stack_reserved_zone();
1729 void enable_stack_yellow_reserved_zone();
1730 void disable_stack_yellow_reserved_zone();
1731 void enable_stack_red_zone();
1732 void disable_stack_red_zone();
1733
1734 inline bool stack_guard_zone_unused();
1735 inline bool stack_yellow_reserved_zone_disabled();
1736 inline bool stack_reserved_zone_disabled();
1737 inline bool stack_guards_enabled();
1738
1739 address reserved_stack_activation() const { return _reserved_stack_activation; }
1740 void set_reserved_stack_activation(address addr) {
1741 assert(_reserved_stack_activation == stack_base()
1742 || _reserved_stack_activation == NULL
1743 || addr == stack_base(), "Must not be set twice");
1744 _reserved_stack_activation = addr;
1745 }
1746
1747 // Attempt to reguard the stack after a stack overflow may have occurred.
1748 // Returns true if (a) guard pages are not needed on this thread, (b) the
1749 // pages are already guarded, or (c) the pages were successfully reguarded.
1750 // Returns false if there is not enough stack space to reguard the pages, in
1751 // which case the caller should unwind a frame and try again. The argument
1752 // should be the caller's (approximate) sp.
1753 bool reguard_stack(address cur_sp);
1754 // Similar to above but see if current stackpoint is out of the guard area
1755 // and reguard if possible.
1756 bool reguard_stack(void);
1757
1758 address stack_overflow_limit() { return _stack_overflow_limit; }
1759 void set_stack_overflow_limit() {
1760 _stack_overflow_limit =
1761 stack_end() + MAX2(JavaThread::stack_guard_zone_size(), JavaThread::stack_shadow_zone_size());
1762 }
1763
1764 // Check if address is in the usable part of the stack (excludes protected
1765 // guard pages). Can be applied to any thread and is an approximation for
1766 // using is_in_live_stack when the query has to happen from another thread.
1767 bool is_in_usable_stack(address adr) const {
1768 return is_in_stack_range_incl(adr, stack_reserved_zone_base());
1769 }
1770
1771 // Misc. accessors/mutators
1772 void set_do_not_unlock(void) { _do_not_unlock_if_synchronized = true; }
1773 void clr_do_not_unlock(void) { _do_not_unlock_if_synchronized = false; }
1774 bool do_not_unlock(void) { return _do_not_unlock_if_synchronized; }
1775
1776 // For assembly stub generation
1777 static ByteSize threadObj_offset() { return byte_offset_of(JavaThread, _threadObj); }
1778 static ByteSize jni_environment_offset() { return byte_offset_of(JavaThread, _jni_environment); }
1779 static ByteSize pending_jni_exception_check_fn_offset() {
1780 return byte_offset_of(JavaThread, _pending_jni_exception_check_fn);
1781 }
1782 static ByteSize last_Java_sp_offset() {
1783 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
1784 }
1785 static ByteSize last_Java_pc_offset() {
1786 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
1787 }
1788 static ByteSize frame_anchor_offset() {
1789 return byte_offset_of(JavaThread, _anchor);
1790 }
1791 static ByteSize callee_target_offset() { return byte_offset_of(JavaThread, _callee_target); }
1792 static ByteSize vm_result_offset() { return byte_offset_of(JavaThread, _vm_result); }
1793 static ByteSize vm_result_2_offset() { return byte_offset_of(JavaThread, _vm_result_2); }
1794 static ByteSize thread_state_offset() { return byte_offset_of(JavaThread, _thread_state); }
1795 static ByteSize saved_exception_pc_offset() { return byte_offset_of(JavaThread, _saved_exception_pc); }
1796 static ByteSize osthread_offset() { return byte_offset_of(JavaThread, _osthread); }
1797 #if INCLUDE_JVMCI
1798 static ByteSize pending_deoptimization_offset() { return byte_offset_of(JavaThread, _pending_deoptimization); }
1799 static ByteSize pending_monitorenter_offset() { return byte_offset_of(JavaThread, _pending_monitorenter); }
1800 static ByteSize pending_failed_speculation_offset() { return byte_offset_of(JavaThread, _pending_failed_speculation); }
1801 static ByteSize jvmci_alternate_call_target_offset() { return byte_offset_of(JavaThread, _jvmci._alternate_call_target); }
1802 static ByteSize jvmci_implicit_exception_pc_offset() { return byte_offset_of(JavaThread, _jvmci._implicit_exception_pc); }
1803 static ByteSize jvmci_counters_offset() { return byte_offset_of(JavaThread, _jvmci_counters); }
1804 #endif // INCLUDE_JVMCI
1805 static ByteSize exception_oop_offset() { return byte_offset_of(JavaThread, _exception_oop); }
1806 static ByteSize exception_pc_offset() { return byte_offset_of(JavaThread, _exception_pc); }
1807 static ByteSize exception_handler_pc_offset() { return byte_offset_of(JavaThread, _exception_handler_pc); }
1808 static ByteSize stack_overflow_limit_offset() { return byte_offset_of(JavaThread, _stack_overflow_limit); }
1809 static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); }
1810 static ByteSize stack_guard_state_offset() { return byte_offset_of(JavaThread, _stack_guard_state); }
1811 static ByteSize reserved_stack_activation_offset() { return byte_offset_of(JavaThread, _reserved_stack_activation); }
1812 static ByteSize suspend_flags_offset() { return byte_offset_of(JavaThread, _suspend_flags); }
1813
1814 static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
1815 static ByteSize should_post_on_exceptions_flag_offset() {
1816 return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
1817 }
1818 static ByteSize doing_unsafe_access_offset() { return byte_offset_of(JavaThread, _doing_unsafe_access); }
1819
1820 // Returns the jni environment for this thread
1821 JNIEnv* jni_environment() { return &_jni_environment; }
1822
1823 static JavaThread* thread_from_jni_environment(JNIEnv* env) {
1824 JavaThread *thread_from_jni_env = (JavaThread*)((intptr_t)env - in_bytes(jni_environment_offset()));
1825 // Only return NULL if thread is off the thread list; starting to
1826 // exit should not return NULL.
1827 if (thread_from_jni_env->is_terminated()) {
1828 thread_from_jni_env->block_if_vm_exited();
1829 return NULL;
1830 } else {
1831 return thread_from_jni_env;
1832 }
1833 }
1834
1835 // JNI critical regions. These can nest.
1836 bool in_critical() { return _jni_active_critical > 0; }
1837 bool in_last_critical() { return _jni_active_critical == 1; }
1838 inline void enter_critical();
1839 void exit_critical() {
1840 assert(Thread::current() == this, "this must be current thread");
1841 _jni_active_critical--;
1842 assert(_jni_active_critical >= 0, "JNI critical nesting problem?");
1843 }
1844
1845 // Checked JNI: is the programmer required to check for exceptions, if so specify
1846 // which function name. Returning to a Java frame should implicitly clear the
1847 // pending check, this is done for Native->Java transitions (i.e. user JNI code).
1848 // VM->Java transistions are not cleared, it is expected that JNI code enclosed
1849 // within ThreadToNativeFromVM makes proper exception checks (i.e. VM internal).
1850 bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != NULL; }
1851 void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = NULL; }
1852 const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; }
1853 void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; }
1854
1855 // For deadlock detection
1856 int depth_first_number() { return _depth_first_number; }
1857 void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
1858
1859 private:
1860 void set_monitor_chunks(MonitorChunk* monitor_chunks) { _monitor_chunks = monitor_chunks; }
1861
1862 public:
1863 MonitorChunk* monitor_chunks() const { return _monitor_chunks; }
1864 void add_monitor_chunk(MonitorChunk* chunk);
1865 void remove_monitor_chunk(MonitorChunk* chunk);
1866 bool in_deopt_handler() const { return _in_deopt_handler > 0; }
1867 void inc_in_deopt_handler() { _in_deopt_handler++; }
1868 void dec_in_deopt_handler() {
1869 assert(_in_deopt_handler > 0, "mismatched deopt nesting");
1870 if (_in_deopt_handler > 0) { // robustness
1871 _in_deopt_handler--;
1872 }
1873 }
1874
1875 private:
1876 void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
1877
1878 public:
1879
1880 // Frame iteration; calls the function f for all frames on the stack
1881 void frames_do(void f(frame*, const RegisterMap*));
1882
1883 // Memory operations
1884 void oops_do(OopClosure* f, CodeBlobClosure* cf);
1885
1886 // Sweeper operations
1887 virtual void nmethods_do(CodeBlobClosure* cf);
1888
1889 // RedefineClasses Support
1890 void metadata_do(MetadataClosure* f);
1891
1892 // Debug method asserting thread states are correct during a handshake operation.
1893 DEBUG_ONLY(void verify_states_for_handshake();)
1894
1895 // Misc. operations
1896 char* name() const { return (char*)get_thread_name(); }
1897 void print_on(outputStream* st, bool print_extended_info) const;
1898 void print_on(outputStream* st) const { print_on(st, false); }
1899 void print() const;
1900 void print_thread_state_on(outputStream*) const PRODUCT_RETURN;
1901 void print_on_error(outputStream* st, char* buf, int buflen) const;
1902 void print_name_on_error(outputStream* st, char* buf, int buflen) const;
1903 void verify();
1904 const char* get_thread_name() const;
1905 protected:
1906 // factor out low-level mechanics for use in both normal and error cases
1907 virtual const char* get_thread_name_string(char* buf = NULL, int buflen = 0) const;
1908 public:
1909 // Accessing frames
1910 frame last_frame() {
1911 _anchor.make_walkable(this);
1912 return pd_last_frame();
1913 }
1914 javaVFrame* last_java_vframe(RegisterMap* reg_map);
1915
1916 // Returns method at 'depth' java or native frames down the stack
1917 // Used for security checks
1918 Klass* security_get_caller_class(int depth);
1919
1920 // Print stack trace in external format
1921 void print_stack_on(outputStream* st);
1922 void print_stack() { print_stack_on(tty); }
1923
1924 // Print stack traces in various internal formats
1925 void trace_stack() PRODUCT_RETURN;
1926 void trace_stack_from(vframe* start_vf) PRODUCT_RETURN;
1927 void trace_frames() PRODUCT_RETURN;
1928
1929 // Print an annotated view of the stack frames
1930 void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN;
1931 void validate_frame_layout() {
1932 print_frame_layout(0, true);
1933 }
1934
1935 // Function for testing deoptimization
1936 void deoptimize();
1937 void make_zombies();
1938
1939 void deoptimize_marked_methods();
1940
1941 public:
1942 // Returns the running thread as a JavaThread
1943 static inline JavaThread* current();
1944
1945 // Returns the active Java thread. Do not use this if you know you are calling
1946 // from a JavaThread, as it's slower than JavaThread::current. If called from
1947 // the VMThread, it also returns the JavaThread that instigated the VMThread's
1948 // operation. You may not want that either.
1949 static JavaThread* active();
1950
1951 inline CompilerThread* as_CompilerThread();
1952
1953 protected:
1954 virtual void pre_run();
1955 virtual void run();
1956 void thread_main_inner();
1957 virtual void post_run();
1958
1959
1960 private:
1961 GrowableArray<oop>* _array_for_gc;
1962 public:
1963
1964 void register_array_for_gc(GrowableArray<oop>* array) { _array_for_gc = array; }
1965
1966 public:
1967 // Thread local information maintained by JVMTI.
1968 void set_jvmti_thread_state(JvmtiThreadState *value) { _jvmti_thread_state = value; }
1969 // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1970 // getter is used to get this JavaThread's JvmtiThreadState if it has
1971 // one which means NULL can be returned. JvmtiThreadState::state_for()
1972 // is used to get the specified JavaThread's JvmtiThreadState if it has
1973 // one or it allocates a new JvmtiThreadState for the JavaThread and
1974 // returns it. JvmtiThreadState::state_for() will return NULL only if
1975 // the specified JavaThread is exiting.
1976 JvmtiThreadState *jvmti_thread_state() const { return _jvmti_thread_state; }
1977 static ByteSize jvmti_thread_state_offset() { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1978
1979 // JVMTI PopFrame support
1980 // Setting and clearing popframe_condition
1981 // All of these enumerated values are bits. popframe_pending
1982 // indicates that a PopFrame() has been requested and not yet been
1983 // completed. popframe_processing indicates that that PopFrame() is in
1984 // the process of being completed. popframe_force_deopt_reexecution_bit
1985 // indicates that special handling is required when returning to a
1986 // deoptimized caller.
1987 enum PopCondition {
1988 popframe_inactive = 0x00,
1989 popframe_pending_bit = 0x01,
1990 popframe_processing_bit = 0x02,
1991 popframe_force_deopt_reexecution_bit = 0x04
1992 };
1993 PopCondition popframe_condition() { return (PopCondition) _popframe_condition; }
1994 void set_popframe_condition(PopCondition c) { _popframe_condition = c; }
1995 void set_popframe_condition_bit(PopCondition c) { _popframe_condition |= c; }
1996 void clear_popframe_condition() { _popframe_condition = popframe_inactive; }
1997 static ByteSize popframe_condition_offset() { return byte_offset_of(JavaThread, _popframe_condition); }
1998 bool has_pending_popframe() { return (popframe_condition() & popframe_pending_bit) != 0; }
1999 bool popframe_forcing_deopt_reexecution() { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
2000 void clear_popframe_forcing_deopt_reexecution() { _popframe_condition &= ~popframe_force_deopt_reexecution_bit; }
2001
2002 bool pop_frame_in_process(void) { return ((_popframe_condition & popframe_processing_bit) != 0); }
2003 void set_pop_frame_in_process(void) { _popframe_condition |= popframe_processing_bit; }
2004 void clr_pop_frame_in_process(void) { _popframe_condition &= ~popframe_processing_bit; }
2005
2006 int frames_to_pop_failed_realloc() const { return _frames_to_pop_failed_realloc; }
2007 void set_frames_to_pop_failed_realloc(int nb) { _frames_to_pop_failed_realloc = nb; }
2008 void dec_frames_to_pop_failed_realloc() { _frames_to_pop_failed_realloc--; }
2009
2010 private:
2011 // Saved incoming arguments to popped frame.
2012 // Used only when popped interpreted frame returns to deoptimized frame.
2013 void* _popframe_preserved_args;
2014 int _popframe_preserved_args_size;
2015
2016 public:
2017 void popframe_preserve_args(ByteSize size_in_bytes, void* start);
2018 void* popframe_preserved_args();
2019 ByteSize popframe_preserved_args_size();
2020 WordSize popframe_preserved_args_size_in_words();
2021 void popframe_free_preserved_args();
2022
2023
2024 private:
2025 JvmtiThreadState *_jvmti_thread_state;
2026
2027 // Used by the interpreter in fullspeed mode for frame pop, method
2028 // entry, method exit and single stepping support. This field is
2029 // only set to non-zero at a safepoint or using a direct handshake
2030 // (see EnterInterpOnlyModeClosure).
2031 // It can be set to zero asynchronously to this threads execution (i.e., without
2032 // safepoint/handshake or a lock) so we have to be very careful.
2033 // Accesses by other threads are synchronized using JvmtiThreadState_lock though.
2034 int _interp_only_mode;
2035
2036 public:
2037 // used by the interpreter for fullspeed debugging support (see above)
2038 static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
2039 bool is_interp_only_mode() { return (_interp_only_mode != 0); }
2040 int get_interp_only_mode() { return _interp_only_mode; }
2041 void increment_interp_only_mode() { ++_interp_only_mode; }
2042 void decrement_interp_only_mode() { --_interp_only_mode; }
2043
2044 // support for cached flag that indicates whether exceptions need to be posted for this thread
2045 // if this is false, we can avoid deoptimizing when events are thrown
2046 // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
2047 private:
2048 int _should_post_on_exceptions_flag;
2049
2050 public:
2051 int should_post_on_exceptions_flag() { return _should_post_on_exceptions_flag; }
2052 void set_should_post_on_exceptions_flag(int val) { _should_post_on_exceptions_flag = val; }
2053
2054 private:
2055 ThreadStatistics *_thread_stat;
2056
2057 public:
2058 ThreadStatistics* get_thread_stat() const { return _thread_stat; }
2059
2060 // Return a blocker object for which this thread is blocked parking.
2061 oop current_park_blocker();
2062
2063 private:
2064 static size_t _stack_size_at_create;
2065
2066 public:
2067 static inline size_t stack_size_at_create(void) {
2068 return _stack_size_at_create;
2069 }
2070 static inline void set_stack_size_at_create(size_t value) {
2071 _stack_size_at_create = value;
2072 }
2073
2074 // Machine dependent stuff
2075 #include OS_CPU_HEADER(thread)
2076
2077 // JSR166 per-thread parker
2078 private:
2079 Parker* _parker;
2080 public:
2081 Parker* parker() { return _parker; }
2082
2083 // Biased locking support
2084 private:
2085 GrowableArray<MonitorInfo*>* _cached_monitor_info;
2086 public:
2087 GrowableArray<MonitorInfo*>* cached_monitor_info() { return _cached_monitor_info; }
2088 void set_cached_monitor_info(GrowableArray<MonitorInfo*>* info) { _cached_monitor_info = info; }
2089
2090 // clearing/querying jni attach status
2091 bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; }
2092 bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
2093 inline void set_done_attaching_via_jni();
2094
2095 // Stack dump assistance:
2096 // Track the class we want to initialize but for which we have to wait
2097 // on its init_lock() because it is already being initialized.
2098 void set_class_to_be_initialized(InstanceKlass* k);
2099 InstanceKlass* class_to_be_initialized() const;
2100
2101 private:
2102 InstanceKlass* _class_to_be_initialized;
2103
2104 // java.lang.Thread.sleep support
2105 ParkEvent * _SleepEvent;
2106 public:
2107 bool sleep(jlong millis);
2108
2109 // java.lang.Thread interruption support
2110 void interrupt();
2111 bool is_interrupted(bool clear_interrupted);
2112
2113 };
2114
2115 // Inline implementation of JavaThread::current
2116 inline JavaThread* JavaThread::current() {
2117 Thread* thread = Thread::current();
2118 assert(thread->is_Java_thread(), "just checking");
2119 return (JavaThread*)thread;
2120 }
2121
2122 inline CompilerThread* JavaThread::as_CompilerThread() {
2123 assert(is_Compiler_thread(), "just checking");
2124 return (CompilerThread*)this;
2125 }
2126
2127 // Dedicated thread to sweep the code cache
2128 class CodeCacheSweeperThread : public JavaThread {
2129 CompiledMethod* _scanned_compiled_method; // nmethod being scanned by the sweeper
2130 public:
2131 CodeCacheSweeperThread();
2132 // Track the nmethod currently being scanned by the sweeper
2133 void set_scanned_compiled_method(CompiledMethod* cm) {
2134 assert(_scanned_compiled_method == NULL || cm == NULL, "should reset to NULL before writing a new value");
2135 _scanned_compiled_method = cm;
2136 }
2137
2138 // Hide sweeper thread from external view.
2139 bool is_hidden_from_external_view() const { return true; }
2140
2141 bool is_Code_cache_sweeper_thread() const { return true; }
2142
2143 // Prevent GC from unloading _scanned_compiled_method
2144 void oops_do(OopClosure* f, CodeBlobClosure* cf);
2145 void nmethods_do(CodeBlobClosure* cf);
2146 };
2147
2148 // A thread used for Compilation.
2149 class CompilerThread : public JavaThread {
2150 friend class VMStructs;
2151 private:
2152 CompilerCounters* _counters;
2153
2154 ciEnv* _env;
2155 CompileLog* _log;
2156 CompileTask* volatile _task; // print_threads_compiling can read this concurrently.
2157 CompileQueue* _queue;
2158 BufferBlob* _buffer_blob;
2159
2160 AbstractCompiler* _compiler;
2161 TimeStamp _idle_time;
2162
2163 public:
2164
2165 static CompilerThread* current();
2166
2167 CompilerThread(CompileQueue* queue, CompilerCounters* counters);
2168 ~CompilerThread();
2169
2170 bool is_Compiler_thread() const { return true; }
2171
2172 virtual bool can_call_java() const;
2173
2174 // Hide native compiler threads from external view.
2175 bool is_hidden_from_external_view() const { return !can_call_java(); }
2176
2177 void set_compiler(AbstractCompiler* c) { _compiler = c; }
2178 AbstractCompiler* compiler() const { return _compiler; }
2179
2180 CompileQueue* queue() const { return _queue; }
2181 CompilerCounters* counters() const { return _counters; }
2182
2183 // Get/set the thread's compilation environment.
2184 ciEnv* env() { return _env; }
2185 void set_env(ciEnv* env) { _env = env; }
2186
2187 BufferBlob* get_buffer_blob() const { return _buffer_blob; }
2188 void set_buffer_blob(BufferBlob* b) { _buffer_blob = b; }
2189
2190 // Get/set the thread's logging information
2191 CompileLog* log() { return _log; }
2192 void init_log(CompileLog* log) {
2193 // Set once, for good.
2194 assert(_log == NULL, "set only once");
2195 _log = log;
2196 }
2197
2198 void start_idle_timer() { _idle_time.update(); }
2199 jlong idle_time_millis() {
2200 return TimeHelper::counter_to_millis(_idle_time.ticks_since_update());
2201 }
2202
2203 #ifndef PRODUCT
2204 private:
2205 IdealGraphPrinter *_ideal_graph_printer;
2206 public:
2207 IdealGraphPrinter *ideal_graph_printer() { return _ideal_graph_printer; }
2208 void set_ideal_graph_printer(IdealGraphPrinter *n) { _ideal_graph_printer = n; }
2209 #endif
2210
2211 // Get/set the thread's current task
2212 CompileTask* task() { return _task; }
2213 void set_task(CompileTask* task) { _task = task; }
2214 };
2215
2216 inline CompilerThread* CompilerThread::current() {
2217 return JavaThread::current()->as_CompilerThread();
2218 }
2219
2220 // The active thread queue. It also keeps track of the current used
2221 // thread priorities.
2222 class Threads: AllStatic {
2223 friend class VMStructs;
2224 private:
2225 static int _number_of_threads;
2226 static int _number_of_non_daemon_threads;
2227 static int _return_code;
2228 static uintx _thread_claim_token;
2229 #ifdef ASSERT
2230 static bool _vm_complete;
2231 #endif
2232
2233 static void initialize_java_lang_classes(JavaThread* main_thread, TRAPS);
2234 static void initialize_jsr292_core_classes(TRAPS);
2235
2236 public:
2237 // Thread management
2238 // force_daemon is a concession to JNI, where we may need to add a
2239 // thread to the thread list before allocating its thread object
2240 static void add(JavaThread* p, bool force_daemon = false);
2241 static void remove(JavaThread* p, bool is_daemon);
2242 static void non_java_threads_do(ThreadClosure* tc);
2243 static void java_threads_do(ThreadClosure* tc);
2244 static void java_threads_and_vm_thread_do(ThreadClosure* tc);
2245 static void threads_do(ThreadClosure* tc);
2246 static void possibly_parallel_threads_do(bool is_par, ThreadClosure* tc);
2247
2248 // Initializes the vm and creates the vm thread
2249 static jint create_vm(JavaVMInitArgs* args, bool* canTryAgain);
2250 static void convert_vm_init_libraries_to_agents();
2251 static void create_vm_init_libraries();
2252 static void create_vm_init_agents();
2253 static void shutdown_vm_agents();
2254 static bool destroy_vm();
2255 // Supported VM versions via JNI
2256 // Includes JNI_VERSION_1_1
2257 static jboolean is_supported_jni_version_including_1_1(jint version);
2258 // Does not include JNI_VERSION_1_1
2259 static jboolean is_supported_jni_version(jint version);
2260
2261 // The "thread claim token" provides a way for threads to be claimed
2262 // by parallel worker tasks.
2263 //
2264 // Each thread contains a "token" field. A task will claim the
2265 // thread only if its token is different from the global token,
2266 // which is updated by calling change_thread_claim_token(). When
2267 // a thread is claimed, it's token is set to the global token value
2268 // so other threads in the same iteration pass won't claim it.
2269 //
2270 // For this to work change_thread_claim_token() needs to be called
2271 // exactly once in sequential code before starting parallel tasks
2272 // that should claim threads.
2273 //
2274 // New threads get their token set to 0 and change_thread_claim_token()
2275 // never sets the global token to 0.
2276 static uintx thread_claim_token() { return _thread_claim_token; }
2277 static void change_thread_claim_token();
2278 static void assert_all_threads_claimed() NOT_DEBUG_RETURN;
2279
2280 // Apply "f->do_oop" to all root oops in all threads.
2281 // This version may only be called by sequential code.
2282 static void oops_do(OopClosure* f, CodeBlobClosure* cf);
2283 // This version may be called by sequential or parallel code.
2284 static void possibly_parallel_oops_do(bool is_par, OopClosure* f, CodeBlobClosure* cf);
2285
2286 // Sweeper
2287 static void nmethods_do(CodeBlobClosure* cf);
2288
2289 // RedefineClasses support
2290 static void metadata_do(MetadataClosure* f);
2291 static void metadata_handles_do(void f(Metadata*));
2292
2293 #ifdef ASSERT
2294 static bool is_vm_complete() { return _vm_complete; }
2295 #endif // ASSERT
2296
2297 // Verification
2298 static void verify();
2299 static void print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks, bool print_extended_info);
2300 static void print(bool print_stacks, bool internal_format) {
2301 // this function is only used by debug.cpp
2302 print_on(tty, print_stacks, internal_format, false /* no concurrent lock printed */, false /* simple format */);
2303 }
2304 static void print_on_error(outputStream* st, Thread* current, char* buf, int buflen);
2305 static void print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
2306 int buflen, bool* found_current);
2307 static void print_threads_compiling(outputStream* st, char* buf, int buflen, bool short_form = false);
2308
2309 // Get Java threads that are waiting to enter a monitor.
2310 static GrowableArray<JavaThread*>* get_pending_threads(ThreadsList * t_list,
2311 int count, address monitor);
2312
2313 // Get owning Java thread from the monitor's owner field.
2314 static JavaThread *owning_thread_from_monitor_owner(ThreadsList * t_list,
2315 address owner);
2316
2317 // Number of threads on the active threads list
2318 static int number_of_threads() { return _number_of_threads; }
2319 // Number of non-daemon threads on the active threads list
2320 static int number_of_non_daemon_threads() { return _number_of_non_daemon_threads; }
2321
2322 // Deoptimizes all frames tied to marked nmethods
2323 static void deoptimized_wrt_marked_nmethods();
2324
2325 struct Test; // For private gtest access.
2326 };
2327
2328 class SignalHandlerMark: public StackObj {
2329 private:
2330 Thread* _thread;
2331 public:
2332 SignalHandlerMark(Thread* t) {
2333 _thread = t;
2334 if (_thread) _thread->enter_signal_handler();
2335 }
2336 ~SignalHandlerMark() {
2337 if (_thread) _thread->leave_signal_handler();
2338 _thread = NULL;
2339 }
2340 };
2341
2342
2343 #endif // SHARE_RUNTIME_THREAD_HPP