1 /*
2 * Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #ifndef SHARE_RUNTIME_THREAD_HPP
26 #define SHARE_RUNTIME_THREAD_HPP
27
28 #include "jni.h"
29 #include "code/compiledMethod.hpp"
30 #include "gc/shared/gcThreadLocalData.hpp"
31 #include "gc/shared/threadLocalAllocBuffer.hpp"
32 #include "memory/allocation.hpp"
33 #include "oops/oop.hpp"
34 #include "prims/jvmtiExport.hpp"
35 #include "runtime/frame.hpp"
36 #include "runtime/globals.hpp"
37 #include "runtime/handshake.hpp"
38 #include "runtime/javaFrameAnchor.hpp"
39 #include "runtime/jniHandles.hpp"
40 #include "runtime/mutexLocker.hpp"
41 #include "runtime/os.hpp"
42 #include "runtime/osThread.hpp"
43 #include "runtime/park.hpp"
44 #include "runtime/stubRoutines.hpp"
45 #include "runtime/threadHeapSampler.hpp"
46 #include "runtime/threadLocalStorage.hpp"
47 #include "runtime/threadStatisticalInfo.hpp"
48 #include "runtime/unhandledOops.hpp"
49 #include "utilities/align.hpp"
50 #include "utilities/exceptions.hpp"
51 #include "utilities/macros.hpp"
52 #ifdef ZERO
53 # include "stack_zero.hpp"
54 #endif
55 #if INCLUDE_JFR
56 #include "jfr/support/jfrThreadExtension.hpp"
57 #endif
58
59
60 class SafeThreadsListPtr;
61 class ThreadSafepointState;
62 class ThreadsList;
63 class ThreadsSMRSupport;
64
65 class JvmtiThreadState;
66 class ThreadStatistics;
67 class ConcurrentLocksDump;
68 class ParkEvent;
69 class Parker;
70 class MonitorInfo;
71
72 class ciEnv;
73 class CompileThread;
74 class CompileLog;
75 class CompileTask;
76 class CompileQueue;
77 class CompilerCounters;
78
79 class vframeArray;
80 class vframe;
81 class javaVFrame;
82
83 class DeoptResourceMark;
84 class jvmtiDeferredLocalVariableSet;
85
86 class GCTaskQueue;
87 class ThreadClosure;
88 class ICRefillVerifier;
89 class IdealGraphPrinter;
90
91 class JVMCIEnv;
92 class JVMCIPrimitiveArray;
93
94 class Metadata;
95 class ResourceArea;
96
97 DEBUG_ONLY(class ResourceMark;)
98
99 class WorkerThread;
100
101 // Class hierarchy
102 // - Thread
103 // - JavaThread
104 // - various subclasses eg CompilerThread, ServiceThread
105 // - NonJavaThread
106 // - NamedThread
107 // - VMThread
108 // - ConcurrentGCThread
109 // - WorkerThread
110 // - GangWorker
111 // - GCTaskThread
112 // - WatcherThread
113 // - JfrThreadSampler
114 //
115 // All Thread subclasses must be either JavaThread or NonJavaThread.
116 // This means !t->is_Java_thread() iff t is a NonJavaThread, or t is
117 // a partially constructed/destroyed Thread.
118
119 // Thread execution sequence and actions:
120 // All threads:
121 // - thread_native_entry // per-OS native entry point
122 // - stack initialization
123 // - other OS-level initialization (signal masks etc)
124 // - handshake with creating thread (if not started suspended)
125 // - this->call_run() // common shared entry point
126 // - shared common initialization
127 // - this->pre_run() // virtual per-thread-type initialization
128 // - this->run() // virtual per-thread-type "main" logic
129 // - shared common tear-down
130 // - this->post_run() // virtual per-thread-type tear-down
131 // - // 'this' no longer referenceable
132 // - OS-level tear-down (minimal)
133 // - final logging
134 //
135 // For JavaThread:
136 // - this->run() // virtual but not normally overridden
137 // - this->thread_main_inner() // extra call level to ensure correct stack calculations
138 // - this->entry_point() // set differently for each kind of JavaThread
139
140 class Thread: public ThreadShadow {
141 friend class VMStructs;
142 friend class JVMCIVMStructs;
143 private:
144
145 #ifndef USE_LIBRARY_BASED_TLS_ONLY
146 // Current thread is maintained as a thread-local variable
147 static THREAD_LOCAL_DECL Thread* _thr_current;
148 #endif
149
150 // Thread local data area available to the GC. The internal
151 // structure and contents of this data area is GC-specific.
152 // Only GC and GC barrier code should access this data area.
153 GCThreadLocalData _gc_data;
154
155 public:
156 static ByteSize gc_data_offset() {
157 return byte_offset_of(Thread, _gc_data);
158 }
159
160 template <typename T> T* gc_data() {
161 STATIC_ASSERT(sizeof(T) <= sizeof(_gc_data));
162 return reinterpret_cast<T*>(&_gc_data);
163 }
164
165 // Exception handling
166 // (Note: _pending_exception and friends are in ThreadShadow)
167 //oop _pending_exception; // pending exception for current thread
168 // const char* _exception_file; // file information for exception (debugging only)
169 // int _exception_line; // line information for exception (debugging only)
170 protected:
171
172 DEBUG_ONLY(static Thread* _starting_thread;)
173
174 // Support for forcing alignment of thread objects for biased locking
175 void* _real_malloc_address;
176
177 // JavaThread lifecycle support:
178 friend class SafeThreadsListPtr; // for _threads_list_ptr, cmpxchg_threads_hazard_ptr(), {dec_,inc_,}nested_threads_hazard_ptr_cnt(), {g,s}et_threads_hazard_ptr(), inc_nested_handle_cnt(), tag_hazard_ptr() access
179 friend class ScanHazardPtrGatherProtectedThreadsClosure; // for cmpxchg_threads_hazard_ptr(), get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
180 friend class ScanHazardPtrGatherThreadsListClosure; // for get_threads_hazard_ptr(), untag_hazard_ptr() access
181 friend class ScanHazardPtrPrintMatchingThreadsClosure; // for get_threads_hazard_ptr(), is_hazard_ptr_tagged() access
182 friend class ThreadsSMRSupport; // for _nested_threads_hazard_ptr_cnt, _threads_hazard_ptr, _threads_list_ptr access
183
184 ThreadsList* volatile _threads_hazard_ptr;
185 SafeThreadsListPtr* _threads_list_ptr;
186 ThreadsList* cmpxchg_threads_hazard_ptr(ThreadsList* exchange_value, ThreadsList* compare_value);
187 ThreadsList* get_threads_hazard_ptr();
188 void set_threads_hazard_ptr(ThreadsList* new_list);
189 static bool is_hazard_ptr_tagged(ThreadsList* list) {
190 return (intptr_t(list) & intptr_t(1)) == intptr_t(1);
191 }
192 static ThreadsList* tag_hazard_ptr(ThreadsList* list) {
193 return (ThreadsList*)(intptr_t(list) | intptr_t(1));
194 }
195 static ThreadsList* untag_hazard_ptr(ThreadsList* list) {
196 return (ThreadsList*)(intptr_t(list) & ~intptr_t(1));
197 }
198 // This field is enabled via -XX:+EnableThreadSMRStatistics:
199 uint _nested_threads_hazard_ptr_cnt;
200 void dec_nested_threads_hazard_ptr_cnt() {
201 assert(_nested_threads_hazard_ptr_cnt != 0, "mismatched {dec,inc}_nested_threads_hazard_ptr_cnt()");
202 _nested_threads_hazard_ptr_cnt--;
203 }
204 void inc_nested_threads_hazard_ptr_cnt() {
205 _nested_threads_hazard_ptr_cnt++;
206 }
207 uint nested_threads_hazard_ptr_cnt() {
208 return _nested_threads_hazard_ptr_cnt;
209 }
210
211 public:
212 void* operator new(size_t size) throw() { return allocate(size, true); }
213 void* operator new(size_t size, const std::nothrow_t& nothrow_constant) throw() {
214 return allocate(size, false); }
215 void operator delete(void* p);
216
217 protected:
218 static void* allocate(size_t size, bool throw_excpt, MEMFLAGS flags = mtThread);
219 private:
220
221 // ***************************************************************
222 // Suspend and resume support
223 // ***************************************************************
224 //
225 // VM suspend/resume no longer exists - it was once used for various
226 // things including safepoints but was deprecated and finally removed
227 // in Java 7. Because VM suspension was considered "internal" Java-level
228 // suspension was considered "external", and this legacy naming scheme
229 // remains.
230 //
231 // External suspend/resume requests come from JVM_SuspendThread,
232 // JVM_ResumeThread, JVMTI SuspendThread, and finally JVMTI
233 // ResumeThread. External
234 // suspend requests cause _external_suspend to be set and external
235 // resume requests cause _external_suspend to be cleared.
236 // External suspend requests do not nest on top of other external
237 // suspend requests. The higher level APIs reject suspend requests
238 // for already suspended threads.
239 //
240 // The external_suspend
241 // flag is checked by has_special_runtime_exit_condition() and java thread
242 // will self-suspend when handle_special_runtime_exit_condition() is
243 // called. Most uses of the _thread_blocked state in JavaThreads are
244 // considered the same as being externally suspended; if the blocking
245 // condition lifts, the JavaThread will self-suspend. Other places
246 // where VM checks for external_suspend include:
247 // + mutex granting (do not enter monitors when thread is suspended)
248 // + state transitions from _thread_in_native
249 //
250 // In general, java_suspend() does not wait for an external suspend
251 // request to complete. When it returns, the only guarantee is that
252 // the _external_suspend field is true.
253 //
254 // wait_for_ext_suspend_completion() is used to wait for an external
255 // suspend request to complete. External suspend requests are usually
256 // followed by some other interface call that requires the thread to
257 // be quiescent, e.g., GetCallTrace(). By moving the "wait time" into
258 // the interface that requires quiescence, we give the JavaThread a
259 // chance to self-suspend before we need it to be quiescent. This
260 // improves overall suspend/query performance.
261 //
262 // _suspend_flags controls the behavior of java_ suspend/resume.
263 // It must be set under the protection of SR_lock. Read from the flag is
264 // OK without SR_lock as long as the value is only used as a hint.
265 // (e.g., check _external_suspend first without lock and then recheck
266 // inside SR_lock and finish the suspension)
267 //
268 // _suspend_flags is also overloaded for other "special conditions" so
269 // that a single check indicates whether any special action is needed
270 // eg. for async exceptions.
271 // -------------------------------------------------------------------
272 // Notes:
273 // 1. The suspend/resume logic no longer uses ThreadState in OSThread
274 // but we still update its value to keep other part of the system (mainly
275 // JVMTI) happy. ThreadState is legacy code (see notes in
276 // osThread.hpp).
277 //
278 // 2. It would be more natural if set_external_suspend() is private and
279 // part of java_suspend(), but that probably would affect the suspend/query
280 // performance. Need more investigation on this.
281
282 // suspend/resume lock: used for self-suspend
283 Monitor* _SR_lock;
284
285 protected:
286 enum SuspendFlags {
287 // NOTE: avoid using the sign-bit as cc generates different test code
288 // when the sign-bit is used, and sometimes incorrectly - see CR 6398077
289
290 _external_suspend = 0x20000000U, // thread is asked to self suspend
291 _ext_suspended = 0x40000000U, // thread has self-suspended
292
293 _has_async_exception = 0x00000001U, // there is a pending async exception
294 _critical_native_unlock = 0x00000002U, // Must call back to unlock JNI critical lock
295
296 _trace_flag = 0x00000004U // call tracing backend
297 };
298
299 // various suspension related flags - atomically updated
300 // overloaded for async exception checking in check_special_condition_for_native_trans.
301 volatile uint32_t _suspend_flags;
302
303 private:
304 int _num_nested_signal;
305
306 DEBUG_ONLY(bool _suspendible_thread;)
307
308 public:
309 void enter_signal_handler() { _num_nested_signal++; }
310 void leave_signal_handler() { _num_nested_signal--; }
311 bool is_inside_signal_handler() const { return _num_nested_signal > 0; }
312
313 // Determines if a heap allocation failure will be retried
314 // (e.g., by deoptimizing and re-executing in the interpreter).
315 // In this case, the failed allocation must raise
316 // Universe::out_of_memory_error_retry() and omit side effects
317 // such as JVMTI events and handling -XX:+HeapDumpOnOutOfMemoryError
318 // and -XX:OnOutOfMemoryError.
319 virtual bool in_retryable_allocation() const { return false; }
320
321 #ifdef ASSERT
322 void set_suspendible_thread() {
323 _suspendible_thread = true;
324 }
325
326 void clear_suspendible_thread() {
327 _suspendible_thread = false;
328 }
329
330 bool is_suspendible_thread() { return _suspendible_thread; }
331 #endif
332
333 private:
334 // Active_handles points to a block of handles
335 JNIHandleBlock* _active_handles;
336
337 // One-element thread local free list
338 JNIHandleBlock* _free_handle_block;
339
340 // Point to the last handle mark
341 HandleMark* _last_handle_mark;
342
343 // Claim value for parallel iteration over threads.
344 uintx _threads_do_token;
345
346 // Support for GlobalCounter
347 private:
348 volatile uintx _rcu_counter;
349 public:
350 volatile uintx* get_rcu_counter() {
351 return &_rcu_counter;
352 }
353
354 public:
355 void set_last_handle_mark(HandleMark* mark) { _last_handle_mark = mark; }
356 HandleMark* last_handle_mark() const { return _last_handle_mark; }
357 private:
358
359 #ifdef ASSERT
360 ICRefillVerifier* _missed_ic_stub_refill_verifier;
361
362 public:
363 ICRefillVerifier* missed_ic_stub_refill_verifier() {
364 return _missed_ic_stub_refill_verifier;
365 }
366
367 void set_missed_ic_stub_refill_verifier(ICRefillVerifier* verifier) {
368 _missed_ic_stub_refill_verifier = verifier;
369 }
370 #endif
371
372 private:
373
374 // debug support for checking if code does allow safepoints or not
375 // GC points in the VM can happen because of allocation, invoking a VM operation, or blocking on
376 // mutex, or blocking on an object synchronizer (Java locking).
377 // If !allow_safepoint(), then an assertion failure will happen in any of the above cases
378 //
379 // The class NoSafepointVerifier is used to set this counter.
380 //
381 NOT_PRODUCT(int _allow_safepoint_count;) // If 0, thread allow a safepoint to happen
382
383 // Used by SkipGCALot class.
384 NOT_PRODUCT(bool _skip_gcalot;) // Should we elide gc-a-lot?
385
386 friend class NoSafepointVerifier;
387 friend class PauseNoSafepointVerifier;
388 friend class GCLocker;
389
390 volatile void* _polling_page; // Thread local polling page
391
392 ThreadLocalAllocBuffer _tlab; // Thread-local eden
393 jlong _allocated_bytes; // Cumulative number of bytes allocated on
394 // the Java heap
395 ThreadHeapSampler _heap_sampler; // For use when sampling the memory.
396
397 ThreadStatisticalInfo _statistical_info; // Statistics about the thread
398
399 JFR_ONLY(DEFINE_THREAD_LOCAL_FIELD_JFR;) // Thread-local data for jfr
400
401 int _vm_operation_started_count; // VM_Operation support
402 int _vm_operation_completed_count; // VM_Operation support
403
404 ObjectMonitor* _current_pending_monitor; // ObjectMonitor this thread
405 // is waiting to lock
406 bool _current_pending_monitor_is_from_java; // locking is from Java code
407
408 // ObjectMonitor on which this thread called Object.wait()
409 ObjectMonitor* _current_waiting_monitor;
410
411 // Private thread-local objectmonitor list - a simple cache organized as a SLL.
412 public:
413 ObjectMonitor* omFreeList;
414 int omFreeCount; // length of omFreeList
415 int omFreeProvision; // reload chunk size
416 ObjectMonitor* omInUseList; // SLL to track monitors in circulation
417 int omInUseCount; // length of omInUseList
418
419 #ifdef ASSERT
420 private:
421 volatile uint64_t _visited_for_critical_count;
422
423 public:
424 void set_visited_for_critical_count(uint64_t safepoint_id) {
425 assert(_visited_for_critical_count == 0, "Must be reset before set");
426 assert((safepoint_id & 0x1) == 1, "Must be odd");
427 _visited_for_critical_count = safepoint_id;
428 }
429 void reset_visited_for_critical_count(uint64_t safepoint_id) {
430 assert(_visited_for_critical_count == safepoint_id, "Was not visited");
431 _visited_for_critical_count = 0;
432 }
433 bool was_visited_for_critical_count(uint64_t safepoint_id) const {
434 return _visited_for_critical_count == safepoint_id;
435 }
436 #endif
437
438 public:
439 enum {
440 is_definitely_current_thread = true
441 };
442
443 // Constructor
444 Thread();
445 virtual ~Thread() = 0; // Thread is abstract.
446
447 // Manage Thread::current()
448 void initialize_thread_current();
449 static void clear_thread_current(); // TLS cleanup needed before threads terminate
450
451 protected:
452 // To be implemented by children.
453 virtual void run() = 0;
454 virtual void pre_run() = 0;
455 virtual void post_run() = 0; // Note: Thread must not be deleted prior to calling this!
456
457 #ifdef ASSERT
458 enum RunState {
459 PRE_CALL_RUN,
460 CALL_RUN,
461 PRE_RUN,
462 RUN,
463 POST_RUN
464 // POST_CALL_RUN - can't define this one as 'this' may be deleted when we want to set it
465 };
466 RunState _run_state; // for lifecycle checks
467 #endif
468
469
470 public:
471 // invokes <ChildThreadClass>::run(), with common preparations and cleanups.
472 void call_run();
473
474 // Testers
475 virtual bool is_VM_thread() const { return false; }
476 virtual bool is_Java_thread() const { return false; }
477 virtual bool is_Compiler_thread() const { return false; }
478 virtual bool is_Code_cache_sweeper_thread() const { return false; }
479 virtual bool is_hidden_from_external_view() const { return false; }
480 virtual bool is_jvmti_agent_thread() const { return false; }
481 // True iff the thread can perform GC operations at a safepoint.
482 // Generally will be true only of VM thread and parallel GC WorkGang
483 // threads.
484 virtual bool is_GC_task_thread() const { return false; }
485 virtual bool is_Watcher_thread() const { return false; }
486 virtual bool is_ConcurrentGC_thread() const { return false; }
487 virtual bool is_Named_thread() const { return false; }
488 virtual bool is_Worker_thread() const { return false; }
489
490 // Can this thread make Java upcalls
491 virtual bool can_call_java() const { return false; }
492
493 // Casts
494 virtual WorkerThread* as_Worker_thread() const { return NULL; }
495
496 virtual char* name() const { return (char*)"Unknown thread"; }
497
498 // Returns the current thread (ASSERTS if NULL)
499 static inline Thread* current();
500 // Returns the current thread, or NULL if not attached
501 static inline Thread* current_or_null();
502 // Returns the current thread, or NULL if not attached, and is
503 // safe for use from signal-handlers
504 static inline Thread* current_or_null_safe();
505
506 // Common thread operations
507 #ifdef ASSERT
508 static void check_for_dangling_thread_pointer(Thread *thread);
509 #endif
510 static void set_priority(Thread* thread, ThreadPriority priority);
511 static ThreadPriority get_priority(const Thread* const thread);
512 static void start(Thread* thread);
513 static void interrupt(Thread* thr);
514 static bool is_interrupted(Thread* thr, bool clear_interrupted);
515
516 void set_native_thread_name(const char *name) {
517 assert(Thread::current() == this, "set_native_thread_name can only be called on the current thread");
518 os::set_native_thread_name(name);
519 }
520
521 ObjectMonitor** omInUseList_addr() { return (ObjectMonitor **)&omInUseList; }
522 Monitor* SR_lock() const { return _SR_lock; }
523
524 bool has_async_exception() const { return (_suspend_flags & _has_async_exception) != 0; }
525
526 inline void set_suspend_flag(SuspendFlags f);
527 inline void clear_suspend_flag(SuspendFlags f);
528
529 inline void set_has_async_exception();
530 inline void clear_has_async_exception();
531
532 bool do_critical_native_unlock() const { return (_suspend_flags & _critical_native_unlock) != 0; }
533
534 inline void set_critical_native_unlock();
535 inline void clear_critical_native_unlock();
536
537 inline void set_trace_flag();
538 inline void clear_trace_flag();
539
540 // Support for Unhandled Oop detection
541 // Add the field for both, fastdebug and debug, builds to keep
542 // Thread's fields layout the same.
543 // Note: CHECK_UNHANDLED_OOPS is defined only for fastdebug build.
544 #ifdef CHECK_UNHANDLED_OOPS
545 private:
546 UnhandledOops* _unhandled_oops;
547 #elif defined(ASSERT)
548 private:
549 void* _unhandled_oops;
550 #endif
551 #ifdef CHECK_UNHANDLED_OOPS
552 public:
553 UnhandledOops* unhandled_oops() { return _unhandled_oops; }
554 // Mark oop safe for gc. It may be stack allocated but won't move.
555 void allow_unhandled_oop(oop *op) {
556 if (CheckUnhandledOops) unhandled_oops()->allow_unhandled_oop(op);
557 }
558 // Clear oops at safepoint so crashes point to unhandled oop violator
559 void clear_unhandled_oops() {
560 if (CheckUnhandledOops) unhandled_oops()->clear_unhandled_oops();
561 }
562 #endif // CHECK_UNHANDLED_OOPS
563
564 public:
565 #ifndef PRODUCT
566 bool skip_gcalot() { return _skip_gcalot; }
567 void set_skip_gcalot(bool v) { _skip_gcalot = v; }
568 #endif
569
570 // Installs a pending exception to be inserted later
571 static void send_async_exception(oop thread_oop, oop java_throwable);
572
573 // Resource area
574 ResourceArea* resource_area() const { return _resource_area; }
575 void set_resource_area(ResourceArea* area) { _resource_area = area; }
576
577 OSThread* osthread() const { return _osthread; }
578 void set_osthread(OSThread* thread) { _osthread = thread; }
579
580 // JNI handle support
581 JNIHandleBlock* active_handles() const { return _active_handles; }
582 void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
583 JNIHandleBlock* free_handle_block() const { return _free_handle_block; }
584 void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
585
586 // Internal handle support
587 HandleArea* handle_area() const { return _handle_area; }
588 void set_handle_area(HandleArea* area) { _handle_area = area; }
589
590 GrowableArray<Metadata*>* metadata_handles() const { return _metadata_handles; }
591 void set_metadata_handles(GrowableArray<Metadata*>* handles){ _metadata_handles = handles; }
592
593 // Thread-Local Allocation Buffer (TLAB) support
594 ThreadLocalAllocBuffer& tlab() { return _tlab; }
595 void initialize_tlab() {
596 if (UseTLAB) {
597 tlab().initialize();
598 }
599 }
600
601 jlong allocated_bytes() { return _allocated_bytes; }
602 void set_allocated_bytes(jlong value) { _allocated_bytes = value; }
603 void incr_allocated_bytes(jlong size) { _allocated_bytes += size; }
604 inline jlong cooked_allocated_bytes();
605
606 ThreadHeapSampler& heap_sampler() { return _heap_sampler; }
607
608 ThreadStatisticalInfo& statistical_info() { return _statistical_info; }
609
610 JFR_ONLY(DEFINE_THREAD_LOCAL_ACCESSOR_JFR;)
611
612 bool is_trace_suspend() { return (_suspend_flags & _trace_flag) != 0; }
613
614 // VM operation support
615 int vm_operation_ticket() { return ++_vm_operation_started_count; }
616 int vm_operation_completed_count() { return _vm_operation_completed_count; }
617 void increment_vm_operation_completed_count() { _vm_operation_completed_count++; }
618
619 // For tracking the heavyweight monitor the thread is pending on.
620 ObjectMonitor* current_pending_monitor() {
621 return _current_pending_monitor;
622 }
623 void set_current_pending_monitor(ObjectMonitor* monitor) {
624 _current_pending_monitor = monitor;
625 }
626 void set_current_pending_monitor_is_from_java(bool from_java) {
627 _current_pending_monitor_is_from_java = from_java;
628 }
629 bool current_pending_monitor_is_from_java() {
630 return _current_pending_monitor_is_from_java;
631 }
632
633 // For tracking the ObjectMonitor on which this thread called Object.wait()
634 ObjectMonitor* current_waiting_monitor() {
635 return _current_waiting_monitor;
636 }
637 void set_current_waiting_monitor(ObjectMonitor* monitor) {
638 _current_waiting_monitor = monitor;
639 }
640
641 // GC support
642 // Apply "f->do_oop" to all root oops in "this".
643 // Used by JavaThread::oops_do.
644 // Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames
645 virtual void oops_do(OopClosure* f, CodeBlobClosure* cf);
646
647 // Handles the parallel case for claim_threads_do.
648 private:
649 bool claim_par_threads_do(uintx claim_token);
650 public:
651 // Requires that "claim_token" is that of the current iteration.
652 // If "is_par" is false, sets the token of "this" to
653 // "claim_token", and returns "true". If "is_par" is true,
654 // uses an atomic instruction to set the current thread's token to
655 // "claim_token", if it is not already. Returns "true" iff the
656 // calling thread does the update, this indicates that the calling thread
657 // has claimed the thread in the current iteration.
658 bool claim_threads_do(bool is_par, uintx claim_token) {
659 if (!is_par) {
660 _threads_do_token = claim_token;
661 return true;
662 } else {
663 return claim_par_threads_do(claim_token);
664 }
665 }
666
667 uintx threads_do_token() const { return _threads_do_token; }
668
669 // jvmtiRedefineClasses support
670 void metadata_handles_do(void f(Metadata*));
671
672 // Used by fast lock support
673 virtual bool is_lock_owned(address adr) const;
674
675 // Check if address is in the stack of the thread (not just for locks).
676 // Warning: the method can only be used on the running thread
677 bool is_in_stack(address adr) const;
678 // Check if address is in the usable part of the stack (excludes protected
679 // guard pages)
680 bool is_in_usable_stack(address adr) const;
681
682 // Sets this thread as starting thread. Returns failure if thread
683 // creation fails due to lack of memory, too many threads etc.
684 bool set_as_starting_thread();
685
686 protected:
687 // OS data associated with the thread
688 OSThread* _osthread; // Platform-specific thread information
689
690 // Thread local resource area for temporary allocation within the VM
691 ResourceArea* _resource_area;
692
693 DEBUG_ONLY(ResourceMark* _current_resource_mark;)
694
695 // Thread local handle area for allocation of handles within the VM
696 HandleArea* _handle_area;
697 GrowableArray<Metadata*>* _metadata_handles;
698
699 // Support for stack overflow handling, get_thread, etc.
700 address _stack_base;
701 size_t _stack_size;
702 uintptr_t _self_raw_id; // used by get_thread (mutable)
703 int _lgrp_id;
704
705 volatile void** polling_page_addr() { return &_polling_page; }
706
707 public:
708 // Stack overflow support
709 address stack_base() const { assert(_stack_base != NULL,"Sanity check"); return _stack_base; }
710 void set_stack_base(address base) { _stack_base = base; }
711 size_t stack_size() const { return _stack_size; }
712 void set_stack_size(size_t size) { _stack_size = size; }
713 address stack_end() const { return stack_base() - stack_size(); }
714 void record_stack_base_and_size();
715 void register_thread_stack_with_NMT() NOT_NMT_RETURN;
716
717 bool on_local_stack(address adr) const {
718 // QQQ this has knowledge of direction, ought to be a stack method
719 return (_stack_base >= adr && adr >= stack_end());
720 }
721
722 uintptr_t self_raw_id() { return _self_raw_id; }
723 void set_self_raw_id(uintptr_t value) { _self_raw_id = value; }
724
725 int lgrp_id() const { return _lgrp_id; }
726 void set_lgrp_id(int value) { _lgrp_id = value; }
727
728 // Printing
729 void print_on(outputStream* st, bool print_extended_info) const;
730 virtual void print_on(outputStream* st) const { print_on(st, false); }
731 void print() const;
732 virtual void print_on_error(outputStream* st, char* buf, int buflen) const;
733 void print_value_on(outputStream* st) const;
734
735 // Debug-only code
736 #ifdef ASSERT
737 private:
738 // Deadlock detection support for Mutex locks. List of locks own by thread.
739 Monitor* _owned_locks;
740 // Mutex::set_owner_implementation is the only place where _owned_locks is modified,
741 // thus the friendship
742 friend class Mutex;
743 friend class Monitor;
744
745 public:
746 void print_owned_locks_on(outputStream* st) const;
747 void print_owned_locks() const { print_owned_locks_on(tty); }
748 Monitor* owned_locks() const { return _owned_locks; }
749 bool owns_locks() const { return owned_locks() != NULL; }
750 bool owns_locks_but_compiled_lock() const;
751
752 // Deadlock detection
753 ResourceMark* current_resource_mark() { return _current_resource_mark; }
754 void set_current_resource_mark(ResourceMark* rm) { _current_resource_mark = rm; }
755 #endif
756
757 void check_for_valid_safepoint_state(bool potential_vm_operation) PRODUCT_RETURN;
758
759 private:
760 volatile int _jvmti_env_iteration_count;
761
762 public:
763 void entering_jvmti_env_iteration() { ++_jvmti_env_iteration_count; }
764 void leaving_jvmti_env_iteration() { --_jvmti_env_iteration_count; }
765 bool is_inside_jvmti_env_iteration() { return _jvmti_env_iteration_count > 0; }
766
767 // Code generation
768 static ByteSize exception_file_offset() { return byte_offset_of(Thread, _exception_file); }
769 static ByteSize exception_line_offset() { return byte_offset_of(Thread, _exception_line); }
770 static ByteSize active_handles_offset() { return byte_offset_of(Thread, _active_handles); }
771
772 static ByteSize stack_base_offset() { return byte_offset_of(Thread, _stack_base); }
773 static ByteSize stack_size_offset() { return byte_offset_of(Thread, _stack_size); }
774
775 static ByteSize polling_page_offset() { return byte_offset_of(Thread, _polling_page); }
776
777 static ByteSize tlab_start_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::start_offset(); }
778 static ByteSize tlab_end_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::end_offset(); }
779 static ByteSize tlab_top_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::top_offset(); }
780 static ByteSize tlab_pf_top_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::pf_top_offset(); }
781
782 static ByteSize allocated_bytes_offset() { return byte_offset_of(Thread, _allocated_bytes); }
783
784 JFR_ONLY(DEFINE_THREAD_LOCAL_OFFSET_JFR;)
785
786 public:
787 volatile intptr_t _Stalled;
788 volatile int _TypeTag;
789 ParkEvent * _ParkEvent; // for synchronized()
790 ParkEvent * _SleepEvent; // for Thread.sleep
791 ParkEvent * _MuxEvent; // for low-level muxAcquire-muxRelease
792 int NativeSyncRecursion; // diagnostic
793
794 volatile int _OnTrap; // Resume-at IP delta
795 jint _hashStateW; // Marsaglia Shift-XOR thread-local RNG
796 jint _hashStateX; // thread-specific hashCode generator state
797 jint _hashStateY;
798 jint _hashStateZ;
799
800 // Low-level leaf-lock primitives used to implement synchronization
801 // and native monitor-mutex infrastructure.
802 // Not for general synchronization use.
803 static void SpinAcquire(volatile int * Lock, const char * Name);
804 static void SpinRelease(volatile int * Lock);
805 static void muxAcquire(volatile intptr_t * Lock, const char * Name);
806 static void muxAcquireW(volatile intptr_t * Lock, ParkEvent * ev);
807 static void muxRelease(volatile intptr_t * Lock);
808 };
809
810 // Inline implementation of Thread::current()
811 inline Thread* Thread::current() {
812 Thread* current = current_or_null();
813 assert(current != NULL, "Thread::current() called on detached thread");
814 return current;
815 }
816
817 inline Thread* Thread::current_or_null() {
818 #ifndef USE_LIBRARY_BASED_TLS_ONLY
819 return _thr_current;
820 #else
821 if (ThreadLocalStorage::is_initialized()) {
822 return ThreadLocalStorage::thread();
823 }
824 return NULL;
825 #endif
826 }
827
828 inline Thread* Thread::current_or_null_safe() {
829 if (ThreadLocalStorage::is_initialized()) {
830 return ThreadLocalStorage::thread();
831 }
832 return NULL;
833 }
834
835 class NonJavaThread: public Thread {
836 friend class VMStructs;
837
838 NonJavaThread* volatile _next;
839
840 class List;
841 static List _the_list;
842
843 void add_to_the_list();
844 void remove_from_the_list();
845
846 protected:
847 virtual void pre_run();
848 virtual void post_run();
849
850 public:
851 NonJavaThread();
852 ~NonJavaThread();
853
854 class Iterator;
855 };
856
857 // Provides iteration over the list of NonJavaThreads.
858 // List addition occurs in pre_run(), and removal occurs in post_run(),
859 // so that only live fully-initialized threads can be found in the list.
860 // Threads created after an iterator is constructed will not be visited
861 // by the iterator. The scope of an iterator is a critical section; there
862 // must be no safepoint checks in that scope.
863 class NonJavaThread::Iterator : public StackObj {
864 uint _protect_enter;
865 NonJavaThread* _current;
866
867 // Noncopyable.
868 Iterator(const Iterator&);
869 Iterator& operator=(const Iterator&);
870
871 public:
872 Iterator();
873 ~Iterator();
874
875 bool end() const { return _current == NULL; }
876 NonJavaThread* current() const { return _current; }
877 void step();
878 };
879
880 // Name support for threads. non-JavaThread subclasses with multiple
881 // uniquely named instances should derive from this.
882 class NamedThread: public NonJavaThread {
883 friend class VMStructs;
884 enum {
885 max_name_len = 64
886 };
887 private:
888 char* _name;
889 // log JavaThread being processed by oops_do
890 JavaThread* _processed_thread;
891 uint _gc_id; // The current GC id when a thread takes part in GC
892
893 public:
894 NamedThread();
895 ~NamedThread();
896 // May only be called once per thread.
897 void set_name(const char* format, ...) ATTRIBUTE_PRINTF(2, 3);
898 virtual bool is_Named_thread() const { return true; }
899 virtual char* name() const { return _name == NULL ? (char*)"Unknown Thread" : _name; }
900 JavaThread *processed_thread() { return _processed_thread; }
901 void set_processed_thread(JavaThread *thread) { _processed_thread = thread; }
902 virtual void print_on(outputStream* st) const;
903
904 void set_gc_id(uint gc_id) { _gc_id = gc_id; }
905 uint gc_id() { return _gc_id; }
906 };
907
908 // Worker threads are named and have an id of an assigned work.
909 class WorkerThread: public NamedThread {
910 private:
911 uint _id;
912 public:
913 WorkerThread() : _id(0) { }
914 virtual bool is_Worker_thread() const { return true; }
915
916 virtual WorkerThread* as_Worker_thread() const {
917 assert(is_Worker_thread(), "Dubious cast to WorkerThread*?");
918 return (WorkerThread*) this;
919 }
920
921 void set_id(uint work_id) { _id = work_id; }
922 uint id() const { return _id; }
923 };
924
925 // A single WatcherThread is used for simulating timer interrupts.
926 class WatcherThread: public NonJavaThread {
927 friend class VMStructs;
928 protected:
929 virtual void run();
930
931 private:
932 static WatcherThread* _watcher_thread;
933
934 static bool _startable;
935 // volatile due to at least one lock-free read
936 volatile static bool _should_terminate;
937 public:
938 enum SomeConstants {
939 delay_interval = 10 // interrupt delay in milliseconds
940 };
941
942 // Constructor
943 WatcherThread();
944
945 // No destruction allowed
946 ~WatcherThread() {
947 guarantee(false, "WatcherThread deletion must fix the race with VM termination");
948 }
949
950 // Tester
951 bool is_Watcher_thread() const { return true; }
952
953 // Printing
954 char* name() const { return (char*)"VM Periodic Task Thread"; }
955 void print_on(outputStream* st) const;
956 void unpark();
957
958 // Returns the single instance of WatcherThread
959 static WatcherThread* watcher_thread() { return _watcher_thread; }
960
961 // Create and start the single instance of WatcherThread, or stop it on shutdown
962 static void start();
963 static void stop();
964 // Only allow start once the VM is sufficiently initialized
965 // Otherwise the first task to enroll will trigger the start
966 static void make_startable();
967 private:
968 int sleep() const;
969 };
970
971
972 class CompilerThread;
973
974 typedef void (*ThreadFunction)(JavaThread*, TRAPS);
975
976 class JavaThread: public Thread {
977 friend class VMStructs;
978 friend class JVMCIVMStructs;
979 friend class WhiteBox;
980 private:
981 bool _on_thread_list; // Is set when this JavaThread is added to the Threads list
982 oop _threadObj; // The Java level thread object
983
984 #ifdef ASSERT
985 private:
986 int _java_call_counter;
987
988 public:
989 int java_call_counter() { return _java_call_counter; }
990 void inc_java_call_counter() { _java_call_counter++; }
991 void dec_java_call_counter() {
992 assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
993 _java_call_counter--;
994 }
995 private: // restore original namespace restriction
996 #endif // ifdef ASSERT
997
998 #ifndef PRODUCT
999 public:
1000 enum {
1001 jump_ring_buffer_size = 16
1002 };
1003 private: // restore original namespace restriction
1004 #endif
1005
1006 JavaFrameAnchor _anchor; // Encapsulation of current java frame and it state
1007
1008 ThreadFunction _entry_point;
1009
1010 JNIEnv _jni_environment;
1011
1012 // Deopt support
1013 DeoptResourceMark* _deopt_mark; // Holds special ResourceMark for deoptimization
1014
1015 intptr_t* _must_deopt_id; // id of frame that needs to be deopted once we
1016 // transition out of native
1017 CompiledMethod* _deopt_nmethod; // CompiledMethod that is currently being deoptimized
1018 vframeArray* _vframe_array_head; // Holds the heap of the active vframeArrays
1019 vframeArray* _vframe_array_last; // Holds last vFrameArray we popped
1020 // Because deoptimization is lazy we must save jvmti requests to set locals
1021 // in compiled frames until we deoptimize and we have an interpreter frame.
1022 // This holds the pointer to array (yeah like there might be more than one) of
1023 // description of compiled vframes that have locals that need to be updated.
1024 GrowableArray<jvmtiDeferredLocalVariableSet*>* _deferred_locals_updates;
1025
1026 // Handshake value for fixing 6243940. We need a place for the i2c
1027 // adapter to store the callee Method*. This value is NEVER live
1028 // across a gc point so it does NOT have to be gc'd
1029 // The handshake is open ended since we can't be certain that it will
1030 // be NULLed. This is because we rarely ever see the race and end up
1031 // in handle_wrong_method which is the backend of the handshake. See
1032 // code in i2c adapters and handle_wrong_method.
1033
1034 Method* _callee_target;
1035
1036 // Used to pass back results to the interpreter or generated code running Java code.
1037 oop _vm_result; // oop result is GC-preserved
1038 Metadata* _vm_result_2; // non-oop result
1039
1040 // See ReduceInitialCardMarks: this holds the precise space interval of
1041 // the most recent slow path allocation for which compiled code has
1042 // elided card-marks for performance along the fast-path.
1043 MemRegion _deferred_card_mark;
1044
1045 MonitorChunk* _monitor_chunks; // Contains the off stack monitors
1046 // allocated during deoptimization
1047 // and by JNI_MonitorEnter/Exit
1048
1049 // Async. requests support
1050 enum AsyncRequests {
1051 _no_async_condition = 0,
1052 _async_exception,
1053 _async_unsafe_access_error
1054 };
1055 AsyncRequests _special_runtime_exit_condition; // Enum indicating pending async. request
1056 oop _pending_async_exception;
1057
1058 // Safepoint support
1059 public: // Expose _thread_state for SafeFetchInt()
1060 volatile JavaThreadState _thread_state;
1061 private:
1062 ThreadSafepointState* _safepoint_state; // Holds information about a thread during a safepoint
1063 address _saved_exception_pc; // Saved pc of instruction where last implicit exception happened
1064
1065 // JavaThread termination support
1066 enum TerminatedTypes {
1067 _not_terminated = 0xDEAD - 2,
1068 _thread_exiting, // JavaThread::exit() has been called for this thread
1069 _thread_terminated, // JavaThread is removed from thread list
1070 _vm_exited // JavaThread is still executing native code, but VM is terminated
1071 // only VM_Exit can set _vm_exited
1072 };
1073
1074 // In general a JavaThread's _terminated field transitions as follows:
1075 //
1076 // _not_terminated => _thread_exiting => _thread_terminated
1077 //
1078 // _vm_exited is a special value to cover the case of a JavaThread
1079 // executing native code after the VM itself is terminated.
1080 volatile TerminatedTypes _terminated;
1081 // suspend/resume support
1082 volatile bool _suspend_equivalent; // Suspend equivalent condition
1083 jint _in_deopt_handler; // count of deoptimization
1084 // handlers thread is in
1085 volatile bool _doing_unsafe_access; // Thread may fault due to unsafe access
1086 bool _do_not_unlock_if_synchronized; // Do not unlock the receiver of a synchronized method (since it was
1087 // never locked) when throwing an exception. Used by interpreter only.
1088
1089 // JNI attach states:
1090 enum JNIAttachStates {
1091 _not_attaching_via_jni = 1, // thread is not attaching via JNI
1092 _attaching_via_jni, // thread is attaching via JNI
1093 _attached_via_jni // thread has attached via JNI
1094 };
1095
1096 // A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
1097 // A native thread that is attaching via JNI starts with a value
1098 // of _attaching_via_jni and transitions to _attached_via_jni.
1099 volatile JNIAttachStates _jni_attach_state;
1100
1101 public:
1102 // State of the stack guard pages for this thread.
1103 enum StackGuardState {
1104 stack_guard_unused, // not needed
1105 stack_guard_reserved_disabled,
1106 stack_guard_yellow_reserved_disabled,// disabled (temporarily) after stack overflow
1107 stack_guard_enabled // enabled
1108 };
1109
1110 private:
1111
1112 #if INCLUDE_JVMCI
1113 // The _pending_* fields below are used to communicate extra information
1114 // from an uncommon trap in JVMCI compiled code to the uncommon trap handler.
1115
1116 // Communicates the DeoptReason and DeoptAction of the uncommon trap
1117 int _pending_deoptimization;
1118
1119 // Specifies whether the uncommon trap is to bci 0 of a synchronized method
1120 // before the monitor has been acquired.
1121 bool _pending_monitorenter;
1122
1123 // Specifies if the DeoptReason for the last uncommon trap was Reason_transfer_to_interpreter
1124 bool _pending_transfer_to_interpreter;
1125
1126 // True if in a runtime call from compiled code that will deoptimize
1127 // and re-execute a failed heap allocation in the interpreter.
1128 bool _in_retryable_allocation;
1129
1130 // An id of a speculation that JVMCI compiled code can use to further describe and
1131 // uniquely identify the speculative optimization guarded by the uncommon trap
1132 jlong _pending_failed_speculation;
1133
1134 // These fields are mutually exclusive in terms of live ranges.
1135 union {
1136 // Communicates the pc at which the most recent implicit exception occurred
1137 // from the signal handler to a deoptimization stub.
1138 address _implicit_exception_pc;
1139
1140 // Communicates an alternative call target to an i2c stub from a JavaCall .
1141 address _alternate_call_target;
1142 } _jvmci;
1143
1144 // Support for high precision, thread sensitive counters in JVMCI compiled code.
1145 jlong* _jvmci_counters;
1146
1147 public:
1148 static jlong* _jvmci_old_thread_counters;
1149 static void collect_counters(jlong* array, int length);
1150
1151 bool resize_counters(int current_size, int new_size);
1152
1153 static bool resize_all_jvmci_counters(int new_size);
1154
1155 private:
1156 #endif // INCLUDE_JVMCI
1157
1158 StackGuardState _stack_guard_state;
1159
1160 // Precompute the limit of the stack as used in stack overflow checks.
1161 // We load it from here to simplify the stack overflow check in assembly.
1162 address _stack_overflow_limit;
1163 address _reserved_stack_activation;
1164
1165 // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
1166 // used to temp. parsing values into and out of the runtime system during exception handling for compiled
1167 // code)
1168 volatile oop _exception_oop; // Exception thrown in compiled code
1169 volatile address _exception_pc; // PC where exception happened
1170 volatile address _exception_handler_pc; // PC for handler of exception
1171 volatile int _is_method_handle_return; // true (== 1) if the current exception PC is a MethodHandle call site.
1172
1173 private:
1174 // support for JNI critical regions
1175 jint _jni_active_critical; // count of entries into JNI critical region
1176
1177 // Checked JNI: function name requires exception check
1178 char* _pending_jni_exception_check_fn;
1179
1180 // For deadlock detection.
1181 int _depth_first_number;
1182
1183 // JVMTI PopFrame support
1184 // This is set to popframe_pending to signal that top Java frame should be popped immediately
1185 int _popframe_condition;
1186
1187 // If reallocation of scalar replaced objects fails, we throw OOM
1188 // and during exception propagation, pop the top
1189 // _frames_to_pop_failed_realloc frames, the ones that reference
1190 // failed reallocations.
1191 int _frames_to_pop_failed_realloc;
1192
1193 #ifndef PRODUCT
1194 int _jmp_ring_index;
1195 struct {
1196 // We use intptr_t instead of address so debugger doesn't try and display strings
1197 intptr_t _target;
1198 intptr_t _instruction;
1199 const char* _file;
1200 int _line;
1201 } _jmp_ring[jump_ring_buffer_size];
1202 #endif // PRODUCT
1203
1204 friend class VMThread;
1205 friend class ThreadWaitTransition;
1206 friend class VM_Exit;
1207
1208 void initialize(); // Initialized the instance variables
1209
1210 public:
1211 // Constructor
1212 JavaThread(bool is_attaching_via_jni = false); // for main thread and JNI attached threads
1213 JavaThread(ThreadFunction entry_point, size_t stack_size = 0);
1214 ~JavaThread();
1215
1216 #ifdef ASSERT
1217 // verify this JavaThread hasn't be published in the Threads::list yet
1218 void verify_not_published();
1219 #endif
1220
1221 //JNI functiontable getter/setter for JVMTI jni function table interception API.
1222 void set_jni_functions(struct JNINativeInterface_* functionTable) {
1223 _jni_environment.functions = functionTable;
1224 }
1225 struct JNINativeInterface_* get_jni_functions() {
1226 return (struct JNINativeInterface_ *)_jni_environment.functions;
1227 }
1228
1229 // This function is called at thread creation to allow
1230 // platform specific thread variables to be initialized.
1231 void cache_global_variables();
1232
1233 // Executes Shutdown.shutdown()
1234 void invoke_shutdown_hooks();
1235
1236 // Cleanup on thread exit
1237 enum ExitType {
1238 normal_exit,
1239 jni_detach
1240 };
1241 void exit(bool destroy_vm, ExitType exit_type = normal_exit);
1242
1243 void cleanup_failed_attach_current_thread(bool is_daemon);
1244
1245 // Testers
1246 virtual bool is_Java_thread() const { return true; }
1247 virtual bool can_call_java() const { return true; }
1248
1249 // Thread oop. threadObj() can be NULL for initial JavaThread
1250 // (or for threads attached via JNI)
1251 oop threadObj() const { return _threadObj; }
1252 void set_threadObj(oop p) { _threadObj = p; }
1253
1254 ThreadPriority java_priority() const; // Read from threadObj()
1255
1256 // Prepare thread and add to priority queue. If a priority is
1257 // not specified, use the priority of the thread object. Threads_lock
1258 // must be held while this function is called.
1259 void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
1260
1261 void set_saved_exception_pc(address pc) { _saved_exception_pc = pc; }
1262 address saved_exception_pc() { return _saved_exception_pc; }
1263
1264
1265 ThreadFunction entry_point() const { return _entry_point; }
1266
1267 // Allocates a new Java level thread object for this thread. thread_name may be NULL.
1268 void allocate_threadObj(Handle thread_group, const char* thread_name, bool daemon, TRAPS);
1269
1270 // Last frame anchor routines
1271
1272 JavaFrameAnchor* frame_anchor(void) { return &_anchor; }
1273
1274 // last_Java_sp
1275 bool has_last_Java_frame() const { return _anchor.has_last_Java_frame(); }
1276 intptr_t* last_Java_sp() const { return _anchor.last_Java_sp(); }
1277
1278 // last_Java_pc
1279
1280 address last_Java_pc(void) { return _anchor.last_Java_pc(); }
1281
1282 // Safepoint support
1283 inline JavaThreadState thread_state() const;
1284 inline void set_thread_state(JavaThreadState s);
1285 inline void set_thread_state_fence(JavaThreadState s); // fence after setting thread state
1286 inline ThreadSafepointState* safepoint_state() const;
1287 inline void set_safepoint_state(ThreadSafepointState* state);
1288 inline bool is_at_poll_safepoint();
1289
1290 // JavaThread termination and lifecycle support:
1291 void smr_delete();
1292 bool on_thread_list() const { return _on_thread_list; }
1293 void set_on_thread_list() { _on_thread_list = true; }
1294
1295 // thread has called JavaThread::exit() or is terminated
1296 bool is_exiting() const;
1297 // thread is terminated (no longer on the threads list); we compare
1298 // against the two non-terminated values so that a freed JavaThread
1299 // will also be considered terminated.
1300 bool check_is_terminated(TerminatedTypes l_terminated) const {
1301 return l_terminated != _not_terminated && l_terminated != _thread_exiting;
1302 }
1303 bool is_terminated() const;
1304 void set_terminated(TerminatedTypes t);
1305 // special for Threads::remove() which is static:
1306 void set_terminated_value();
1307 void block_if_vm_exited();
1308
1309 bool doing_unsafe_access() { return _doing_unsafe_access; }
1310 void set_doing_unsafe_access(bool val) { _doing_unsafe_access = val; }
1311
1312 bool do_not_unlock_if_synchronized() { return _do_not_unlock_if_synchronized; }
1313 void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
1314
1315 inline void set_polling_page_release(void* poll_value);
1316 inline void set_polling_page(void* poll_value);
1317 inline volatile void* get_polling_page();
1318
1319 private:
1320 // Support for thread handshake operations
1321 HandshakeState _handshake;
1322 public:
1323 void set_handshake_operation(HandshakeOperation* op) {
1324 _handshake.set_operation(this, op);
1325 }
1326
1327 bool has_handshake() const {
1328 return _handshake.has_operation();
1329 }
1330
1331 void handshake_process_by_self() {
1332 _handshake.process_by_self(this);
1333 }
1334
1335 void handshake_process_by_vmthread() {
1336 _handshake.process_by_vmthread(this);
1337 }
1338
1339 // Suspend/resume support for JavaThread
1340 private:
1341 inline void set_ext_suspended();
1342 inline void clear_ext_suspended();
1343
1344 public:
1345 void java_suspend(); // higher-level suspension logic called by the public APIs
1346 void java_resume(); // higher-level resume logic called by the public APIs
1347 int java_suspend_self(); // low-level self-suspension mechanics
1348
1349 private:
1350 // mid-level wrapper around java_suspend_self to set up correct state and
1351 // check for a pending safepoint at the end
1352 void java_suspend_self_with_safepoint_check();
1353
1354 public:
1355 void check_and_wait_while_suspended() {
1356 assert(JavaThread::current() == this, "sanity check");
1357
1358 bool do_self_suspend;
1359 do {
1360 // were we externally suspended while we were waiting?
1361 do_self_suspend = handle_special_suspend_equivalent_condition();
1362 if (do_self_suspend) {
1363 // don't surprise the thread that suspended us by returning
1364 java_suspend_self();
1365 set_suspend_equivalent();
1366 }
1367 } while (do_self_suspend);
1368 }
1369 static void check_safepoint_and_suspend_for_native_trans(JavaThread *thread);
1370 // Check for async exception in addition to safepoint and suspend request.
1371 static void check_special_condition_for_native_trans(JavaThread *thread);
1372
1373 // Same as check_special_condition_for_native_trans but finishes the
1374 // transition into thread_in_Java mode so that it can potentially
1375 // block.
1376 static void check_special_condition_for_native_trans_and_transition(JavaThread *thread);
1377
1378 bool is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits);
1379 bool is_ext_suspend_completed_with_lock(uint32_t *bits) {
1380 MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1381 // Warning: is_ext_suspend_completed() may temporarily drop the
1382 // SR_lock to allow the thread to reach a stable thread state if
1383 // it is currently in a transient thread state.
1384 return is_ext_suspend_completed(false /* !called_by_wait */,
1385 SuspendRetryDelay, bits);
1386 }
1387
1388 // We cannot allow wait_for_ext_suspend_completion() to run forever or
1389 // we could hang. SuspendRetryCount and SuspendRetryDelay are normally
1390 // passed as the count and delay parameters. Experiments with specific
1391 // calls to wait_for_ext_suspend_completion() can be done by passing
1392 // other values in the code. Experiments with all calls can be done
1393 // via the appropriate -XX options.
1394 bool wait_for_ext_suspend_completion(int count, int delay, uint32_t *bits);
1395
1396 // test for suspend - most (all?) of these should go away
1397 bool is_thread_fully_suspended(bool wait_for_suspend, uint32_t *bits);
1398
1399 inline void set_external_suspend();
1400 inline void clear_external_suspend();
1401
1402 bool is_external_suspend() const {
1403 return (_suspend_flags & _external_suspend) != 0;
1404 }
1405 // Whenever a thread transitions from native to vm/java it must suspend
1406 // if external|deopt suspend is present.
1407 bool is_suspend_after_native() const {
1408 return (_suspend_flags & (_external_suspend JFR_ONLY(| _trace_flag))) != 0;
1409 }
1410
1411 // external suspend request is completed
1412 bool is_ext_suspended() const {
1413 return (_suspend_flags & _ext_suspended) != 0;
1414 }
1415
1416 bool is_external_suspend_with_lock() const {
1417 MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1418 return is_external_suspend();
1419 }
1420
1421 // Special method to handle a pending external suspend request
1422 // when a suspend equivalent condition lifts.
1423 bool handle_special_suspend_equivalent_condition() {
1424 assert(is_suspend_equivalent(),
1425 "should only be called in a suspend equivalence condition");
1426 MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1427 bool ret = is_external_suspend();
1428 if (!ret) {
1429 // not about to self-suspend so clear suspend equivalence
1430 clear_suspend_equivalent();
1431 }
1432 // implied else:
1433 // We have a pending external suspend request so we leave the
1434 // suspend_equivalent flag set until java_suspend_self() sets
1435 // the ext_suspended flag and clears the suspend_equivalent
1436 // flag. This insures that wait_for_ext_suspend_completion()
1437 // will return consistent values.
1438 return ret;
1439 }
1440
1441 // utility methods to see if we are doing some kind of suspension
1442 bool is_being_ext_suspended() const {
1443 MutexLocker ml(SR_lock(), Mutex::_no_safepoint_check_flag);
1444 return is_ext_suspended() || is_external_suspend();
1445 }
1446
1447 bool is_suspend_equivalent() const { return _suspend_equivalent; }
1448
1449 void set_suspend_equivalent() { _suspend_equivalent = true; }
1450 void clear_suspend_equivalent() { _suspend_equivalent = false; }
1451
1452 // Thread.stop support
1453 void send_thread_stop(oop throwable);
1454 AsyncRequests clear_special_runtime_exit_condition() {
1455 AsyncRequests x = _special_runtime_exit_condition;
1456 _special_runtime_exit_condition = _no_async_condition;
1457 return x;
1458 }
1459
1460 // Are any async conditions present?
1461 bool has_async_condition() { return (_special_runtime_exit_condition != _no_async_condition); }
1462
1463 void check_and_handle_async_exceptions(bool check_unsafe_error = true);
1464
1465 // these next two are also used for self-suspension and async exception support
1466 void handle_special_runtime_exit_condition(bool check_asyncs = true);
1467
1468 // Return true if JavaThread has an asynchronous condition or
1469 // if external suspension is requested.
1470 bool has_special_runtime_exit_condition() {
1471 // Because we don't use is_external_suspend_with_lock
1472 // it is possible that we won't see an asynchronous external suspend
1473 // request that has just gotten started, i.e., SR_lock grabbed but
1474 // _external_suspend field change either not made yet or not visible
1475 // yet. However, this is okay because the request is asynchronous and
1476 // we will see the new flag value the next time through. It's also
1477 // possible that the external suspend request is dropped after
1478 // we have checked is_external_suspend(), we will recheck its value
1479 // under SR_lock in java_suspend_self().
1480 return (_special_runtime_exit_condition != _no_async_condition) ||
1481 is_external_suspend() || is_trace_suspend();
1482 }
1483
1484 void set_pending_unsafe_access_error() { _special_runtime_exit_condition = _async_unsafe_access_error; }
1485
1486 inline void set_pending_async_exception(oop e);
1487
1488 // Fast-locking support
1489 bool is_lock_owned(address adr) const;
1490
1491 // Accessors for vframe array top
1492 // The linked list of vframe arrays are sorted on sp. This means when we
1493 // unpack the head must contain the vframe array to unpack.
1494 void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
1495 vframeArray* vframe_array_head() const { return _vframe_array_head; }
1496
1497 // Side structure for deferring update of java frame locals until deopt occurs
1498 GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred_locals() const { return _deferred_locals_updates; }
1499 void set_deferred_locals(GrowableArray<jvmtiDeferredLocalVariableSet *>* vf) { _deferred_locals_updates = vf; }
1500
1501 // These only really exist to make debugging deopt problems simpler
1502
1503 void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
1504 vframeArray* vframe_array_last() const { return _vframe_array_last; }
1505
1506 // The special resourceMark used during deoptimization
1507
1508 void set_deopt_mark(DeoptResourceMark* value) { _deopt_mark = value; }
1509 DeoptResourceMark* deopt_mark(void) { return _deopt_mark; }
1510
1511 intptr_t* must_deopt_id() { return _must_deopt_id; }
1512 void set_must_deopt_id(intptr_t* id) { _must_deopt_id = id; }
1513 void clear_must_deopt_id() { _must_deopt_id = NULL; }
1514
1515 void set_deopt_compiled_method(CompiledMethod* nm) { _deopt_nmethod = nm; }
1516 CompiledMethod* deopt_compiled_method() { return _deopt_nmethod; }
1517
1518 Method* callee_target() const { return _callee_target; }
1519 void set_callee_target (Method* x) { _callee_target = x; }
1520
1521 // Oop results of vm runtime calls
1522 oop vm_result() const { return _vm_result; }
1523 void set_vm_result (oop x) { _vm_result = x; }
1524
1525 Metadata* vm_result_2() const { return _vm_result_2; }
1526 void set_vm_result_2 (Metadata* x) { _vm_result_2 = x; }
1527
1528 MemRegion deferred_card_mark() const { return _deferred_card_mark; }
1529 void set_deferred_card_mark(MemRegion mr) { _deferred_card_mark = mr; }
1530
1531 #if INCLUDE_JVMCI
1532 int pending_deoptimization() const { return _pending_deoptimization; }
1533 jlong pending_failed_speculation() const { return _pending_failed_speculation; }
1534 bool has_pending_monitorenter() const { return _pending_monitorenter; }
1535 void set_pending_monitorenter(bool b) { _pending_monitorenter = b; }
1536 void set_pending_deoptimization(int reason) { _pending_deoptimization = reason; }
1537 void set_pending_failed_speculation(jlong failed_speculation) { _pending_failed_speculation = failed_speculation; }
1538 void set_pending_transfer_to_interpreter(bool b) { _pending_transfer_to_interpreter = b; }
1539 void set_jvmci_alternate_call_target(address a) { assert(_jvmci._alternate_call_target == NULL, "must be"); _jvmci._alternate_call_target = a; }
1540 void set_jvmci_implicit_exception_pc(address a) { assert(_jvmci._implicit_exception_pc == NULL, "must be"); _jvmci._implicit_exception_pc = a; }
1541
1542 virtual bool in_retryable_allocation() const { return _in_retryable_allocation; }
1543 void set_in_retryable_allocation(bool b) { _in_retryable_allocation = b; }
1544 #endif // INCLUDE_JVMCI
1545
1546 // Exception handling for compiled methods
1547 oop exception_oop() const { return _exception_oop; }
1548 address exception_pc() const { return _exception_pc; }
1549 address exception_handler_pc() const { return _exception_handler_pc; }
1550 bool is_method_handle_return() const { return _is_method_handle_return == 1; }
1551
1552 void set_exception_oop(oop o) { (void)const_cast<oop&>(_exception_oop = o); }
1553 void set_exception_pc(address a) { _exception_pc = a; }
1554 void set_exception_handler_pc(address a) { _exception_handler_pc = a; }
1555 void set_is_method_handle_return(bool value) { _is_method_handle_return = value ? 1 : 0; }
1556
1557 void clear_exception_oop_and_pc() {
1558 set_exception_oop(NULL);
1559 set_exception_pc(NULL);
1560 }
1561
1562 // Stack overflow support
1563 //
1564 // (small addresses)
1565 //
1566 // -- <-- stack_end() ---
1567 // | |
1568 // | red pages |
1569 // | |
1570 // -- <-- stack_red_zone_base() |
1571 // | |
1572 // | guard
1573 // | yellow pages zone
1574 // | |
1575 // | |
1576 // -- <-- stack_yellow_zone_base() |
1577 // | |
1578 // | |
1579 // | reserved pages |
1580 // | |
1581 // -- <-- stack_reserved_zone_base() --- ---
1582 // /|\ shadow <-- stack_overflow_limit() (somewhere in here)
1583 // | zone
1584 // \|/ size
1585 // some untouched memory ---
1586 //
1587 //
1588 // --
1589 // |
1590 // | shadow zone
1591 // |
1592 // --
1593 // x frame n
1594 // --
1595 // x frame n-1
1596 // x
1597 // --
1598 // ...
1599 //
1600 // --
1601 // x frame 0
1602 // -- <-- stack_base()
1603 //
1604 // (large addresses)
1605 //
1606
1607 private:
1608 // These values are derived from flags StackRedPages, StackYellowPages,
1609 // StackReservedPages and StackShadowPages. The zone size is determined
1610 // ergonomically if page_size > 4K.
1611 static size_t _stack_red_zone_size;
1612 static size_t _stack_yellow_zone_size;
1613 static size_t _stack_reserved_zone_size;
1614 static size_t _stack_shadow_zone_size;
1615 public:
1616 inline size_t stack_available(address cur_sp);
1617
1618 static size_t stack_red_zone_size() {
1619 assert(_stack_red_zone_size > 0, "Don't call this before the field is initialized.");
1620 return _stack_red_zone_size;
1621 }
1622 static void set_stack_red_zone_size(size_t s) {
1623 assert(is_aligned(s, os::vm_page_size()),
1624 "We can not protect if the red zone size is not page aligned.");
1625 assert(_stack_red_zone_size == 0, "This should be called only once.");
1626 _stack_red_zone_size = s;
1627 }
1628 address stack_red_zone_base() {
1629 return (address)(stack_end() + stack_red_zone_size());
1630 }
1631 bool in_stack_red_zone(address a) {
1632 return a <= stack_red_zone_base() && a >= stack_end();
1633 }
1634
1635 static size_t stack_yellow_zone_size() {
1636 assert(_stack_yellow_zone_size > 0, "Don't call this before the field is initialized.");
1637 return _stack_yellow_zone_size;
1638 }
1639 static void set_stack_yellow_zone_size(size_t s) {
1640 assert(is_aligned(s, os::vm_page_size()),
1641 "We can not protect if the yellow zone size is not page aligned.");
1642 assert(_stack_yellow_zone_size == 0, "This should be called only once.");
1643 _stack_yellow_zone_size = s;
1644 }
1645
1646 static size_t stack_reserved_zone_size() {
1647 // _stack_reserved_zone_size may be 0. This indicates the feature is off.
1648 return _stack_reserved_zone_size;
1649 }
1650 static void set_stack_reserved_zone_size(size_t s) {
1651 assert(is_aligned(s, os::vm_page_size()),
1652 "We can not protect if the reserved zone size is not page aligned.");
1653 assert(_stack_reserved_zone_size == 0, "This should be called only once.");
1654 _stack_reserved_zone_size = s;
1655 }
1656 address stack_reserved_zone_base() {
1657 return (address)(stack_end() +
1658 (stack_red_zone_size() + stack_yellow_zone_size() + stack_reserved_zone_size()));
1659 }
1660 bool in_stack_reserved_zone(address a) {
1661 return (a <= stack_reserved_zone_base()) &&
1662 (a >= (address)((intptr_t)stack_reserved_zone_base() - stack_reserved_zone_size()));
1663 }
1664
1665 static size_t stack_yellow_reserved_zone_size() {
1666 return _stack_yellow_zone_size + _stack_reserved_zone_size;
1667 }
1668 bool in_stack_yellow_reserved_zone(address a) {
1669 return (a <= stack_reserved_zone_base()) && (a >= stack_red_zone_base());
1670 }
1671
1672 // Size of red + yellow + reserved zones.
1673 static size_t stack_guard_zone_size() {
1674 return stack_red_zone_size() + stack_yellow_reserved_zone_size();
1675 }
1676
1677 static size_t stack_shadow_zone_size() {
1678 assert(_stack_shadow_zone_size > 0, "Don't call this before the field is initialized.");
1679 return _stack_shadow_zone_size;
1680 }
1681 static void set_stack_shadow_zone_size(size_t s) {
1682 // The shadow area is not allocated or protected, so
1683 // it needs not be page aligned.
1684 // But the stack bang currently assumes that it is a
1685 // multiple of page size. This guarantees that the bang
1686 // loop touches all pages in the shadow zone.
1687 // This can be guaranteed differently, as well. E.g., if
1688 // the page size is a multiple of 4K, banging in 4K steps
1689 // suffices to touch all pages. (Some pages are banged
1690 // several times, though.)
1691 assert(is_aligned(s, os::vm_page_size()),
1692 "Stack bang assumes multiple of page size.");
1693 assert(_stack_shadow_zone_size == 0, "This should be called only once.");
1694 _stack_shadow_zone_size = s;
1695 }
1696
1697 void create_stack_guard_pages();
1698 void remove_stack_guard_pages();
1699
1700 void enable_stack_reserved_zone();
1701 void disable_stack_reserved_zone();
1702 void enable_stack_yellow_reserved_zone();
1703 void disable_stack_yellow_reserved_zone();
1704 void enable_stack_red_zone();
1705 void disable_stack_red_zone();
1706
1707 inline bool stack_guard_zone_unused();
1708 inline bool stack_yellow_reserved_zone_disabled();
1709 inline bool stack_reserved_zone_disabled();
1710 inline bool stack_guards_enabled();
1711
1712 address reserved_stack_activation() const { return _reserved_stack_activation; }
1713 void set_reserved_stack_activation(address addr) {
1714 assert(_reserved_stack_activation == stack_base()
1715 || _reserved_stack_activation == NULL
1716 || addr == stack_base(), "Must not be set twice");
1717 _reserved_stack_activation = addr;
1718 }
1719
1720 // Attempt to reguard the stack after a stack overflow may have occurred.
1721 // Returns true if (a) guard pages are not needed on this thread, (b) the
1722 // pages are already guarded, or (c) the pages were successfully reguarded.
1723 // Returns false if there is not enough stack space to reguard the pages, in
1724 // which case the caller should unwind a frame and try again. The argument
1725 // should be the caller's (approximate) sp.
1726 bool reguard_stack(address cur_sp);
1727 // Similar to above but see if current stackpoint is out of the guard area
1728 // and reguard if possible.
1729 bool reguard_stack(void);
1730
1731 address stack_overflow_limit() { return _stack_overflow_limit; }
1732 void set_stack_overflow_limit() {
1733 _stack_overflow_limit =
1734 stack_end() + MAX2(JavaThread::stack_guard_zone_size(), JavaThread::stack_shadow_zone_size());
1735 }
1736
1737 // Misc. accessors/mutators
1738 void set_do_not_unlock(void) { _do_not_unlock_if_synchronized = true; }
1739 void clr_do_not_unlock(void) { _do_not_unlock_if_synchronized = false; }
1740 bool do_not_unlock(void) { return _do_not_unlock_if_synchronized; }
1741
1742 #ifndef PRODUCT
1743 void record_jump(address target, address instr, const char* file, int line);
1744 #endif // PRODUCT
1745
1746 // For assembly stub generation
1747 static ByteSize threadObj_offset() { return byte_offset_of(JavaThread, _threadObj); }
1748 #ifndef PRODUCT
1749 static ByteSize jmp_ring_index_offset() { return byte_offset_of(JavaThread, _jmp_ring_index); }
1750 static ByteSize jmp_ring_offset() { return byte_offset_of(JavaThread, _jmp_ring); }
1751 #endif // PRODUCT
1752 static ByteSize jni_environment_offset() { return byte_offset_of(JavaThread, _jni_environment); }
1753 static ByteSize pending_jni_exception_check_fn_offset() {
1754 return byte_offset_of(JavaThread, _pending_jni_exception_check_fn);
1755 }
1756 static ByteSize last_Java_sp_offset() {
1757 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
1758 }
1759 static ByteSize last_Java_pc_offset() {
1760 return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
1761 }
1762 static ByteSize frame_anchor_offset() {
1763 return byte_offset_of(JavaThread, _anchor);
1764 }
1765 static ByteSize callee_target_offset() { return byte_offset_of(JavaThread, _callee_target); }
1766 static ByteSize vm_result_offset() { return byte_offset_of(JavaThread, _vm_result); }
1767 static ByteSize vm_result_2_offset() { return byte_offset_of(JavaThread, _vm_result_2); }
1768 static ByteSize thread_state_offset() { return byte_offset_of(JavaThread, _thread_state); }
1769 static ByteSize saved_exception_pc_offset() { return byte_offset_of(JavaThread, _saved_exception_pc); }
1770 static ByteSize osthread_offset() { return byte_offset_of(JavaThread, _osthread); }
1771 #if INCLUDE_JVMCI
1772 static ByteSize pending_deoptimization_offset() { return byte_offset_of(JavaThread, _pending_deoptimization); }
1773 static ByteSize pending_monitorenter_offset() { return byte_offset_of(JavaThread, _pending_monitorenter); }
1774 static ByteSize pending_failed_speculation_offset() { return byte_offset_of(JavaThread, _pending_failed_speculation); }
1775 static ByteSize jvmci_alternate_call_target_offset() { return byte_offset_of(JavaThread, _jvmci._alternate_call_target); }
1776 static ByteSize jvmci_implicit_exception_pc_offset() { return byte_offset_of(JavaThread, _jvmci._implicit_exception_pc); }
1777 static ByteSize jvmci_counters_offset() { return byte_offset_of(JavaThread, _jvmci_counters); }
1778 #endif // INCLUDE_JVMCI
1779 static ByteSize exception_oop_offset() { return byte_offset_of(JavaThread, _exception_oop); }
1780 static ByteSize exception_pc_offset() { return byte_offset_of(JavaThread, _exception_pc); }
1781 static ByteSize exception_handler_pc_offset() { return byte_offset_of(JavaThread, _exception_handler_pc); }
1782 static ByteSize stack_overflow_limit_offset() { return byte_offset_of(JavaThread, _stack_overflow_limit); }
1783 static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); }
1784 static ByteSize stack_guard_state_offset() { return byte_offset_of(JavaThread, _stack_guard_state); }
1785 static ByteSize reserved_stack_activation_offset() { return byte_offset_of(JavaThread, _reserved_stack_activation); }
1786 static ByteSize suspend_flags_offset() { return byte_offset_of(JavaThread, _suspend_flags); }
1787
1788 static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
1789 static ByteSize should_post_on_exceptions_flag_offset() {
1790 return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
1791 }
1792 static ByteSize doing_unsafe_access_offset() { return byte_offset_of(JavaThread, _doing_unsafe_access); }
1793
1794 // Returns the jni environment for this thread
1795 JNIEnv* jni_environment() { return &_jni_environment; }
1796
1797 static JavaThread* thread_from_jni_environment(JNIEnv* env) {
1798 JavaThread *thread_from_jni_env = (JavaThread*)((intptr_t)env - in_bytes(jni_environment_offset()));
1799 // Only return NULL if thread is off the thread list; starting to
1800 // exit should not return NULL.
1801 if (thread_from_jni_env->is_terminated()) {
1802 thread_from_jni_env->block_if_vm_exited();
1803 return NULL;
1804 } else {
1805 return thread_from_jni_env;
1806 }
1807 }
1808
1809 // JNI critical regions. These can nest.
1810 bool in_critical() { return _jni_active_critical > 0; }
1811 bool in_last_critical() { return _jni_active_critical == 1; }
1812 inline void enter_critical();
1813 void exit_critical() {
1814 assert(Thread::current() == this, "this must be current thread");
1815 _jni_active_critical--;
1816 assert(_jni_active_critical >= 0, "JNI critical nesting problem?");
1817 }
1818
1819 // Checked JNI: is the programmer required to check for exceptions, if so specify
1820 // which function name. Returning to a Java frame should implicitly clear the
1821 // pending check, this is done for Native->Java transitions (i.e. user JNI code).
1822 // VM->Java transistions are not cleared, it is expected that JNI code enclosed
1823 // within ThreadToNativeFromVM makes proper exception checks (i.e. VM internal).
1824 bool is_pending_jni_exception_check() const { return _pending_jni_exception_check_fn != NULL; }
1825 void clear_pending_jni_exception_check() { _pending_jni_exception_check_fn = NULL; }
1826 const char* get_pending_jni_exception_check() const { return _pending_jni_exception_check_fn; }
1827 void set_pending_jni_exception_check(const char* fn_name) { _pending_jni_exception_check_fn = (char*) fn_name; }
1828
1829 // For deadlock detection
1830 int depth_first_number() { return _depth_first_number; }
1831 void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
1832
1833 private:
1834 void set_monitor_chunks(MonitorChunk* monitor_chunks) { _monitor_chunks = monitor_chunks; }
1835
1836 public:
1837 MonitorChunk* monitor_chunks() const { return _monitor_chunks; }
1838 void add_monitor_chunk(MonitorChunk* chunk);
1839 void remove_monitor_chunk(MonitorChunk* chunk);
1840 bool in_deopt_handler() const { return _in_deopt_handler > 0; }
1841 void inc_in_deopt_handler() { _in_deopt_handler++; }
1842 void dec_in_deopt_handler() {
1843 assert(_in_deopt_handler > 0, "mismatched deopt nesting");
1844 if (_in_deopt_handler > 0) { // robustness
1845 _in_deopt_handler--;
1846 }
1847 }
1848
1849 private:
1850 void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
1851
1852 public:
1853
1854 // Frame iteration; calls the function f for all frames on the stack
1855 void frames_do(void f(frame*, const RegisterMap*));
1856
1857 // Memory operations
1858 void oops_do(OopClosure* f, CodeBlobClosure* cf);
1859
1860 // Sweeper operations
1861 virtual void nmethods_do(CodeBlobClosure* cf);
1862
1863 // RedefineClasses Support
1864 void metadata_do(MetadataClosure* f);
1865
1866 // Debug method asserting thread states are correct during a handshake operation.
1867 DEBUG_ONLY(void verify_states_for_handshake();)
1868
1869 // Misc. operations
1870 char* name() const { return (char*)get_thread_name(); }
1871 void print_on(outputStream* st, bool print_extended_info) const;
1872 void print_on(outputStream* st) const { print_on(st, false); }
1873 void print() const;
1874 void print_value();
1875 void print_thread_state_on(outputStream*) const PRODUCT_RETURN;
1876 void print_thread_state() const PRODUCT_RETURN;
1877 void print_on_error(outputStream* st, char* buf, int buflen) const;
1878 void print_name_on_error(outputStream* st, char* buf, int buflen) const;
1879 void verify();
1880 const char* get_thread_name() const;
1881 protected:
1882 // factor out low-level mechanics for use in both normal and error cases
1883 virtual const char* get_thread_name_string(char* buf = NULL, int buflen = 0) const;
1884 public:
1885 const char* get_threadgroup_name() const;
1886 const char* get_parent_name() const;
1887
1888 // Accessing frames
1889 frame last_frame() {
1890 _anchor.make_walkable(this);
1891 return pd_last_frame();
1892 }
1893 javaVFrame* last_java_vframe(RegisterMap* reg_map);
1894
1895 // Returns method at 'depth' java or native frames down the stack
1896 // Used for security checks
1897 Klass* security_get_caller_class(int depth);
1898
1899 // Print stack trace in external format
1900 void print_stack_on(outputStream* st);
1901 void print_stack() { print_stack_on(tty); }
1902
1903 // Print stack traces in various internal formats
1904 void trace_stack() PRODUCT_RETURN;
1905 void trace_stack_from(vframe* start_vf) PRODUCT_RETURN;
1906 void trace_frames() PRODUCT_RETURN;
1907 void trace_oops() PRODUCT_RETURN;
1908
1909 // Print an annotated view of the stack frames
1910 void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN;
1911 void validate_frame_layout() {
1912 print_frame_layout(0, true);
1913 }
1914
1915 // Returns the number of stack frames on the stack
1916 int depth() const;
1917
1918 // Function for testing deoptimization
1919 void deoptimize();
1920 void make_zombies();
1921
1922 void deoptimized_wrt_marked_nmethods();
1923
1924 public:
1925 // Returns the running thread as a JavaThread
1926 static inline JavaThread* current();
1927
1928 // Returns the active Java thread. Do not use this if you know you are calling
1929 // from a JavaThread, as it's slower than JavaThread::current. If called from
1930 // the VMThread, it also returns the JavaThread that instigated the VMThread's
1931 // operation. You may not want that either.
1932 static JavaThread* active();
1933
1934 inline CompilerThread* as_CompilerThread();
1935
1936 protected:
1937 virtual void pre_run();
1938 virtual void run();
1939 void thread_main_inner();
1940 virtual void post_run();
1941
1942
1943 private:
1944 GrowableArray<oop>* _array_for_gc;
1945 public:
1946
1947 void register_array_for_gc(GrowableArray<oop>* array) { _array_for_gc = array; }
1948
1949 public:
1950 // Thread local information maintained by JVMTI.
1951 void set_jvmti_thread_state(JvmtiThreadState *value) { _jvmti_thread_state = value; }
1952 // A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
1953 // getter is used to get this JavaThread's JvmtiThreadState if it has
1954 // one which means NULL can be returned. JvmtiThreadState::state_for()
1955 // is used to get the specified JavaThread's JvmtiThreadState if it has
1956 // one or it allocates a new JvmtiThreadState for the JavaThread and
1957 // returns it. JvmtiThreadState::state_for() will return NULL only if
1958 // the specified JavaThread is exiting.
1959 JvmtiThreadState *jvmti_thread_state() const { return _jvmti_thread_state; }
1960 static ByteSize jvmti_thread_state_offset() { return byte_offset_of(JavaThread, _jvmti_thread_state); }
1961
1962 // JVMTI PopFrame support
1963 // Setting and clearing popframe_condition
1964 // All of these enumerated values are bits. popframe_pending
1965 // indicates that a PopFrame() has been requested and not yet been
1966 // completed. popframe_processing indicates that that PopFrame() is in
1967 // the process of being completed. popframe_force_deopt_reexecution_bit
1968 // indicates that special handling is required when returning to a
1969 // deoptimized caller.
1970 enum PopCondition {
1971 popframe_inactive = 0x00,
1972 popframe_pending_bit = 0x01,
1973 popframe_processing_bit = 0x02,
1974 popframe_force_deopt_reexecution_bit = 0x04
1975 };
1976 PopCondition popframe_condition() { return (PopCondition) _popframe_condition; }
1977 void set_popframe_condition(PopCondition c) { _popframe_condition = c; }
1978 void set_popframe_condition_bit(PopCondition c) { _popframe_condition |= c; }
1979 void clear_popframe_condition() { _popframe_condition = popframe_inactive; }
1980 static ByteSize popframe_condition_offset() { return byte_offset_of(JavaThread, _popframe_condition); }
1981 bool has_pending_popframe() { return (popframe_condition() & popframe_pending_bit) != 0; }
1982 bool popframe_forcing_deopt_reexecution() { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
1983 void clear_popframe_forcing_deopt_reexecution() { _popframe_condition &= ~popframe_force_deopt_reexecution_bit; }
1984 #ifdef CC_INTERP
1985 bool pop_frame_pending(void) { return ((_popframe_condition & popframe_pending_bit) != 0); }
1986 void clr_pop_frame_pending(void) { _popframe_condition = popframe_inactive; }
1987 bool pop_frame_in_process(void) { return ((_popframe_condition & popframe_processing_bit) != 0); }
1988 void set_pop_frame_in_process(void) { _popframe_condition |= popframe_processing_bit; }
1989 void clr_pop_frame_in_process(void) { _popframe_condition &= ~popframe_processing_bit; }
1990 #endif
1991
1992 int frames_to_pop_failed_realloc() const { return _frames_to_pop_failed_realloc; }
1993 void set_frames_to_pop_failed_realloc(int nb) { _frames_to_pop_failed_realloc = nb; }
1994 void dec_frames_to_pop_failed_realloc() { _frames_to_pop_failed_realloc--; }
1995
1996 private:
1997 // Saved incoming arguments to popped frame.
1998 // Used only when popped interpreted frame returns to deoptimized frame.
1999 void* _popframe_preserved_args;
2000 int _popframe_preserved_args_size;
2001
2002 public:
2003 void popframe_preserve_args(ByteSize size_in_bytes, void* start);
2004 void* popframe_preserved_args();
2005 ByteSize popframe_preserved_args_size();
2006 WordSize popframe_preserved_args_size_in_words();
2007 void popframe_free_preserved_args();
2008
2009
2010 private:
2011 JvmtiThreadState *_jvmti_thread_state;
2012
2013 // Used by the interpreter in fullspeed mode for frame pop, method
2014 // entry, method exit and single stepping support. This field is
2015 // only set to non-zero by the VM_EnterInterpOnlyMode VM operation.
2016 // It can be set to zero asynchronously (i.e., without a VM operation
2017 // or a lock) so we have to be very careful.
2018 int _interp_only_mode;
2019
2020 public:
2021 // used by the interpreter for fullspeed debugging support (see above)
2022 static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
2023 bool is_interp_only_mode() { return (_interp_only_mode != 0); }
2024 int get_interp_only_mode() { return _interp_only_mode; }
2025 void increment_interp_only_mode() { ++_interp_only_mode; }
2026 void decrement_interp_only_mode() { --_interp_only_mode; }
2027
2028 // support for cached flag that indicates whether exceptions need to be posted for this thread
2029 // if this is false, we can avoid deoptimizing when events are thrown
2030 // this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
2031 private:
2032 int _should_post_on_exceptions_flag;
2033
2034 public:
2035 int should_post_on_exceptions_flag() { return _should_post_on_exceptions_flag; }
2036 void set_should_post_on_exceptions_flag(int val) { _should_post_on_exceptions_flag = val; }
2037
2038 private:
2039 ThreadStatistics *_thread_stat;
2040
2041 public:
2042 ThreadStatistics* get_thread_stat() const { return _thread_stat; }
2043
2044 // Return a blocker object for which this thread is blocked parking.
2045 oop current_park_blocker();
2046
2047 private:
2048 static size_t _stack_size_at_create;
2049
2050 public:
2051 static inline size_t stack_size_at_create(void) {
2052 return _stack_size_at_create;
2053 }
2054 static inline void set_stack_size_at_create(size_t value) {
2055 _stack_size_at_create = value;
2056 }
2057
2058 // Machine dependent stuff
2059 #include OS_CPU_HEADER(thread)
2060
2061 public:
2062 void set_blocked_on_compilation(bool value) {
2063 _blocked_on_compilation = value;
2064 }
2065
2066 bool blocked_on_compilation() {
2067 return _blocked_on_compilation;
2068 }
2069 protected:
2070 bool _blocked_on_compilation;
2071
2072
2073 // JSR166 per-thread parker
2074 private:
2075 Parker* _parker;
2076 public:
2077 Parker* parker() { return _parker; }
2078
2079 // Biased locking support
2080 private:
2081 GrowableArray<MonitorInfo*>* _cached_monitor_info;
2082 public:
2083 GrowableArray<MonitorInfo*>* cached_monitor_info() { return _cached_monitor_info; }
2084 void set_cached_monitor_info(GrowableArray<MonitorInfo*>* info) { _cached_monitor_info = info; }
2085
2086 // clearing/querying jni attach status
2087 bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; }
2088 bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
2089 inline void set_done_attaching_via_jni();
2090
2091 // Stack dump assistance:
2092 // Track the class we want to initialize but for which we have to wait
2093 // on its init_lock() because it is already being initialized.
2094 void set_class_to_be_initialized(InstanceKlass* k);
2095 InstanceKlass* class_to_be_initialized() const;
2096
2097 private:
2098 InstanceKlass* _class_to_be_initialized;
2099
2100 };
2101
2102 // Inline implementation of JavaThread::current
2103 inline JavaThread* JavaThread::current() {
2104 Thread* thread = Thread::current();
2105 assert(thread->is_Java_thread(), "just checking");
2106 return (JavaThread*)thread;
2107 }
2108
2109 inline CompilerThread* JavaThread::as_CompilerThread() {
2110 assert(is_Compiler_thread(), "just checking");
2111 return (CompilerThread*)this;
2112 }
2113
2114 // Dedicated thread to sweep the code cache
2115 class CodeCacheSweeperThread : public JavaThread {
2116 CompiledMethod* _scanned_compiled_method; // nmethod being scanned by the sweeper
2117 public:
2118 CodeCacheSweeperThread();
2119 // Track the nmethod currently being scanned by the sweeper
2120 void set_scanned_compiled_method(CompiledMethod* cm) {
2121 assert(_scanned_compiled_method == NULL || cm == NULL, "should reset to NULL before writing a new value");
2122 _scanned_compiled_method = cm;
2123 }
2124
2125 // Hide sweeper thread from external view.
2126 bool is_hidden_from_external_view() const { return true; }
2127
2128 bool is_Code_cache_sweeper_thread() const { return true; }
2129
2130 // Prevent GC from unloading _scanned_compiled_method
2131 void oops_do(OopClosure* f, CodeBlobClosure* cf);
2132 void nmethods_do(CodeBlobClosure* cf);
2133 };
2134
2135 // A thread used for Compilation.
2136 class CompilerThread : public JavaThread {
2137 friend class VMStructs;
2138 private:
2139 CompilerCounters* _counters;
2140
2141 ciEnv* _env;
2142 CompileLog* _log;
2143 CompileTask* volatile _task; // print_threads_compiling can read this concurrently.
2144 CompileQueue* _queue;
2145 BufferBlob* _buffer_blob;
2146
2147 AbstractCompiler* _compiler;
2148 TimeStamp _idle_time;
2149
2150 public:
2151
2152 static CompilerThread* current();
2153
2154 CompilerThread(CompileQueue* queue, CompilerCounters* counters);
2155 ~CompilerThread();
2156
2157 bool is_Compiler_thread() const { return true; }
2158
2159 virtual bool can_call_java() const;
2160
2161 // Hide native compiler threads from external view.
2162 bool is_hidden_from_external_view() const { return !can_call_java(); }
2163
2164 void set_compiler(AbstractCompiler* c) { _compiler = c; }
2165 AbstractCompiler* compiler() const { return _compiler; }
2166
2167 CompileQueue* queue() const { return _queue; }
2168 CompilerCounters* counters() const { return _counters; }
2169
2170 // Get/set the thread's compilation environment.
2171 ciEnv* env() { return _env; }
2172 void set_env(ciEnv* env) { _env = env; }
2173
2174 BufferBlob* get_buffer_blob() const { return _buffer_blob; }
2175 void set_buffer_blob(BufferBlob* b) { _buffer_blob = b; }
2176
2177 // Get/set the thread's logging information
2178 CompileLog* log() { return _log; }
2179 void init_log(CompileLog* log) {
2180 // Set once, for good.
2181 assert(_log == NULL, "set only once");
2182 _log = log;
2183 }
2184
2185 void start_idle_timer() { _idle_time.update(); }
2186 jlong idle_time_millis() {
2187 return TimeHelper::counter_to_millis(_idle_time.ticks_since_update());
2188 }
2189
2190 #ifndef PRODUCT
2191 private:
2192 IdealGraphPrinter *_ideal_graph_printer;
2193 public:
2194 IdealGraphPrinter *ideal_graph_printer() { return _ideal_graph_printer; }
2195 void set_ideal_graph_printer(IdealGraphPrinter *n) { _ideal_graph_printer = n; }
2196 #endif
2197
2198 // Get/set the thread's current task
2199 CompileTask* task() { return _task; }
2200 void set_task(CompileTask* task) { _task = task; }
2201 };
2202
2203 inline CompilerThread* CompilerThread::current() {
2204 return JavaThread::current()->as_CompilerThread();
2205 }
2206
2207 // The active thread queue. It also keeps track of the current used
2208 // thread priorities.
2209 class Threads: AllStatic {
2210 friend class VMStructs;
2211 private:
2212 static int _number_of_threads;
2213 static int _number_of_non_daemon_threads;
2214 static int _return_code;
2215 static uintx _thread_claim_token;
2216 #ifdef ASSERT
2217 static bool _vm_complete;
2218 #endif
2219
2220 static void initialize_java_lang_classes(JavaThread* main_thread, TRAPS);
2221 static void initialize_jsr292_core_classes(TRAPS);
2222
2223 public:
2224 // Thread management
2225 // force_daemon is a concession to JNI, where we may need to add a
2226 // thread to the thread list before allocating its thread object
2227 static void add(JavaThread* p, bool force_daemon = false);
2228 static void remove(JavaThread* p, bool is_daemon);
2229 static void non_java_threads_do(ThreadClosure* tc);
2230 static void java_threads_do(ThreadClosure* tc);
2231 static void java_threads_and_vm_thread_do(ThreadClosure* tc);
2232 static void threads_do(ThreadClosure* tc);
2233 static void possibly_parallel_threads_do(bool is_par, ThreadClosure* tc);
2234
2235 // Initializes the vm and creates the vm thread
2236 static jint create_vm(JavaVMInitArgs* args, bool* canTryAgain);
2237 static void convert_vm_init_libraries_to_agents();
2238 static void create_vm_init_libraries();
2239 static void create_vm_init_agents();
2240 static void shutdown_vm_agents();
2241 static bool destroy_vm();
2242 // Supported VM versions via JNI
2243 // Includes JNI_VERSION_1_1
2244 static jboolean is_supported_jni_version_including_1_1(jint version);
2245 // Does not include JNI_VERSION_1_1
2246 static jboolean is_supported_jni_version(jint version);
2247
2248 // The "thread claim token" provides a way for threads to be claimed
2249 // by parallel worker tasks.
2250 //
2251 // Each thread contains a "token" field. A task will claim the
2252 // thread only if its token is different from the global token,
2253 // which is updated by calling change_thread_claim_token(). When
2254 // a thread is claimed, it's token is set to the global token value
2255 // so other threads in the same iteration pass won't claim it.
2256 //
2257 // For this to work change_thread_claim_token() needs to be called
2258 // exactly once in sequential code before starting parallel tasks
2259 // that should claim threads.
2260 //
2261 // New threads get their token set to 0 and change_thread_claim_token()
2262 // never sets the global token to 0.
2263 static uintx thread_claim_token() { return _thread_claim_token; }
2264 static void change_thread_claim_token();
2265 static void assert_all_threads_claimed() NOT_DEBUG_RETURN;
2266
2267 // Apply "f->do_oop" to all root oops in all threads.
2268 // This version may only be called by sequential code.
2269 static void oops_do(OopClosure* f, CodeBlobClosure* cf);
2270 // This version may be called by sequential or parallel code.
2271 static void possibly_parallel_oops_do(bool is_par, OopClosure* f, CodeBlobClosure* cf);
2272
2273 // Apply "f->do_oop" to roots in all threads that
2274 // are part of compiled frames
2275 static void compiled_frame_oops_do(OopClosure* f, CodeBlobClosure* cf);
2276
2277 static void convert_hcode_pointers();
2278 static void restore_hcode_pointers();
2279
2280 // Sweeper
2281 static void nmethods_do(CodeBlobClosure* cf);
2282
2283 // RedefineClasses support
2284 static void metadata_do(MetadataClosure* f);
2285 static void metadata_handles_do(void f(Metadata*));
2286
2287 #ifdef ASSERT
2288 static bool is_vm_complete() { return _vm_complete; }
2289 #endif // ASSERT
2290
2291 // Verification
2292 static void verify();
2293 static void print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks, bool print_extended_info);
2294 static void print(bool print_stacks, bool internal_format) {
2295 // this function is only used by debug.cpp
2296 print_on(tty, print_stacks, internal_format, false /* no concurrent lock printed */, false /* simple format */);
2297 }
2298 static void print_on_error(outputStream* st, Thread* current, char* buf, int buflen);
2299 static void print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
2300 int buflen, bool* found_current);
2301 static void print_threads_compiling(outputStream* st, char* buf, int buflen, bool short_form = false);
2302
2303 // Get Java threads that are waiting to enter a monitor.
2304 static GrowableArray<JavaThread*>* get_pending_threads(ThreadsList * t_list,
2305 int count, address monitor);
2306
2307 // Get owning Java thread from the monitor's owner field.
2308 static JavaThread *owning_thread_from_monitor_owner(ThreadsList * t_list,
2309 address owner);
2310
2311 // Number of threads on the active threads list
2312 static int number_of_threads() { return _number_of_threads; }
2313 // Number of non-daemon threads on the active threads list
2314 static int number_of_non_daemon_threads() { return _number_of_non_daemon_threads; }
2315
2316 // Deoptimizes all frames tied to marked nmethods
2317 static void deoptimized_wrt_marked_nmethods();
2318
2319 struct Test; // For private gtest access.
2320 };
2321
2322
2323 // Thread iterator
2324 class ThreadClosure: public StackObj {
2325 public:
2326 virtual void do_thread(Thread* thread) = 0;
2327 };
2328
2329 class SignalHandlerMark: public StackObj {
2330 private:
2331 Thread* _thread;
2332 public:
2333 SignalHandlerMark(Thread* t) {
2334 _thread = t;
2335 if (_thread) _thread->enter_signal_handler();
2336 }
2337 ~SignalHandlerMark() {
2338 if (_thread) _thread->leave_signal_handler();
2339 _thread = NULL;
2340 }
2341 };
2342
2343
2344 #endif // SHARE_RUNTIME_THREAD_HPP