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